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Despite a frequent effective therapeutic response in the first months of administration of targeted therapeutics the patients with an ALK rearrangement relapse or progress, essentially due to the emergence of mutations in ALK . Many different ALK mutations occur and can be detected by NGS analysis with free circulating tumor DNA. The detection of these mutations leads to changes in the targeted therapeutics. It is important to note that depending on the treatment used to target an ALK rearrangement, the resistance mutations that emerge on the ALK gene can be different . For example, the L1196M mutation often occurs after treatment with crizotinib, G1202R after ceritinib or alectinib, F1174C after ceretinib and I1171T/N/S after alectinib treatment .
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other
| 98.2 |
As for the detection of EGFR activating and resistance mutations, LB can hold specific indications and advantages compared to a tissue biopsy (Table 1). Thus, this approach is non-invasive, can be repeated easily and can be an alternative to tissue analysis for an ALK rearrangement. In fact, an analysis using blood can be first performed when a tissue biopsy cannot be performed (in the case of the presence of a non-biopsiable tumor site and if the patient is fragile), when the percentage of tumor cells in a tissue biopsy is too small and/or when the amount/quality of biopsy tissue is insufficient (inadequate fixation used, hypo- or hyper-fixation, cell flattening or presence of an extensive zone of necrosis). Within the context of follow-up of patients receiving targeted therapy, LB holds several advantages compared to tissue biopsy. During tumor progression of fragile patients, this non-invasive approach can investigate persistent rearrangement or detect resistance mutation onset in the ALK gene and thereby treatment can be adapted with respect to the observed mutation. After a change in the treatment, renewed LB can be again performed at different times to look for the appearance of new mutations of the ALK gene. Monitoring of patients treated with crizotinib or alectinib can also be done by liquid biopsy. The persistence or reemergence of an ALK rearrangement can indicate the absence of response to treatment or can predict radiological progression before the appearance of clinical symptoms.
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review
| 99.56 |
Despite this, the detection in blood of the ALK status and ALK mutations holds certain limits (Table 1). The detection of CTCs is not a standardized approach of daily practice and reproducibility requires good technical skills. Moreover, CTC detection techniques are not available in all institutions and thus not easily accessible to all patients. The detection of an ALK rearrangement in plasma or in platelets can only be performed if the pre-analytical phases are perfectly controlled (appropriate tubes to collect and package the blood, short delay for transfer to the laboratory, well established centrifugation protocols, storage of plasma or platelets at low temperature). Beyond mastering the techniques, it should be noted that the amount of CTCs or plasma RNA or RNA associated with platelets can be very variable depending on the patient and the tumor biology and the tumor mass. Thus, certain patients, even during the metastatic phase, can have a very low number of CTCs and/or a low amount of plasma RNA. In addition, it is possible that 10 mL of blood is not sufficient to isolate enough quantity of tumor RNA, particularly for NGS methods.
|
review
| 99.7 |
ALK rearrangements and ALK mutations can be detected with a LB. The specificity of detection is very good with CTCs, plasma and platelets. As described above, different approaches exist and the combination of these approaches might increase the chance to detect ALK rearrangements and ALK mutations. However, future efforts should be done to compare these methods in the same cohorts of patients to see the potentiality to use them simultaneously to increase the number of ALK positive blood samples. In the event of a positive result in blood samples, correlation with the results obtained with tissues is excellent. In contrast, the sensitivity is variable depending on the approach used, notably for techniques developed with plasma free RNA. The benefit of LB is the same as for the detection of EGFR mutations in blood: (i) for detection of an ALK rearrangement when it is impossible to perform a tissue biopsy or if the tissue sample is degraded or not exploitable; (ii) for early detection of ALK mutations associated with resistance to treatment leading to a rapid change in the therapeutic strategy; and (iii) for monitoring of the efficacy of treatments targeting an ALK rearrangement when this genomic alteration is lost or inversely reappears in blood.
|
review
| 99.9 |
The challenge now is certainly to increase the sensitivity of the blood tests for this detection and to optimize the NGS approach, combining the search for EGFR; rearrangements in ALK, ROS1, RET, and NTKR, but also other genomic alterations such as BRAF, HER2, and MET; and investigations for MSI-H in LB. This requires mastering the pre-analytical phase as soon as the blood is sampled and the development of more sensitive technologies with a minimal amount of circulating DNA/RNA. Currently, other approaches are being studied for determination of the ALK status in urine or with plasma microRNAs . Finally, one of the major issues will be to propose robust and reproducible analytical tests to define the ALK status in blood, under the guise of quality control with accredited tests approved according to international norms .
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other
| 96.4 |
Dementia is a progressive, neurodegenerative disease. Currently, 850,000 people in the United Kingdom are living with dementia, and this figure will rise to over two million by 2051 (Alzheimer’s Society, 2014). A large proportion of the estimated 400,000 residents in UK care homes have dementia or another form of cognitive impairment (Care Quality Commission, 2010). Policy documents addressing dementia care are available in the UK and other countries including for example, USA and Australia (Ouwens, Wollersheim, Hermens, Hulscher, & Grol, 2005), but there is little attention to care at the end of life (Nakanishi et al., 2015).
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other
| 73.0 |
People at the advanced stages of dementia may become doubly incontinent, unable to communicate their needs and often have multiple co-morbidities such as diabetes and hypertension (Gage et al., 2012). They are at increased risk of hospitalisation, following chest and urinary tract infections and frequently experience pain, anxiety and swallowing problems (Vandervoort et al., 2013). Despite these complex needs, people with advanced dementia often receive fragmented and suboptimal care at the end of life (Gage et al., 2012; Goddard, Stewart, Thompson, & Hall, 2013), and anticipation of future needs or care planning does not occur routinely. The recent White paper on the provision of optimal end of life care for people with dementia suggests that care for those approaching death should be provided by a multidisciplinary team (van der Steen et al., 2014).
|
review
| 99.9 |
Integrated care involves excellent communication between services, information sharing across disciplines and proactive anticipatory care, in particular management of symptoms and has been suggested to improve care outcomes (Wolfs et al., 2011). Integrated care models demonstrate improvement to both quality of care for those with chronic conditions (Ouwens et al., 2005) and quality of life of those at the early stages of dementia (Wolfs, Kessels, Dirksen, Severens, & Verhey, 2008). Importantly, people with advanced dementia should also have access to palliative care services (Lloyd-Williams, Abba, & Crowther, 2014), although research suggests that current palliative care teams may not be prepared for communication and behavioural problems presented by people with advanced dementia (Kupeli et al., 2016).
|
review
| 99.9 |
In the UK, the majority (53%) of those with dementia died in a long-term care institution in 2010 (Sleeman, Ho, Verne, Gao, & Higginson, 2014). In the UK, the National Health Service (NHS) allocates health and social care funding through local Clinical Commissioning Groups (CCGs). Clinical commissioners within CCGs are responsible for commissioning services that are lacking in their locality. Care homes are regulated by the Care Quality Commission (CQC), which is an independent organisation responsible for regulating and monitoring health and social care service providers to ensure the provision of care is safe, effective and of a high quality. The CQC are also responsible for ensuring that safeguarding procedures are adhered to by care homes. Safeguarding guidelines have been developed to ensure that vulnerable individuals are protected from harm and neglect.
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other
| 99.9 |
However, care homes struggle to meet the needs of those who are approaching the end of life (Davies et al., 2014; Goddard et al., 2013). It has been suggested that palliative services are fragmented (Davies et al., 2014) and care homes are isolated within the wider network of services (Seymour, Kumar, & Froggatt, 2011). These issues are complicated by frequent reports that care home staff may have little skill in recognising when death is approaching and poor knowledge of medications commonly used to manage likely symptoms (Watson, Hockley, & Dewar, 2006). None of these studies, however, examine the issue of integrated palliative care within the care home setting from the perspective of those working both in care homes and provide support from external services.
|
review
| 99.75 |
We aimed to identify the barriers to providing integrated care as understood by care professionals working with people with advanced dementia residing in care homes (all with some nursing beds). The work formed part of a larger national mixed methods programme to develop a complex intervention to improve end of life care for people with advanced dementia, as well as support those close to them.
|
study
| 74.0 |
We used purposive sampling to recruit Health Care Professionals (HCPs) across a range of organisations providing care for people with dementia. To gain a thorough and detailed understanding of HCPs experiences of providing care, we used a realist approach and in-depth interactive interviews (Pawson & Tilley, 1997). We interviewed a range of HCPs working for various organisations across North and South London including care homes and NHS services such as memory clinics, mental health and commissioning services. Interactive interviews enabled the interviewer and respondent to engage in a creative discussion without the restrictive parameters imposed by tightly structured interview schedules (Pawson & Tilley, 1997). Potential respondents were identified by research staff recruiting residents from care homes to a parallel cohort study (Sampson et al., 2016) and through the research team’s knowledge of other relevant HCPs. All respondents were sent a study information sheet and a reply slip to return to the researcher within two weeks. Those who returned the reply slip indicating their interest were contacted by research staff and appointments were made for interviews to take place at a location of the respondent’s choice, which for the majority of HCPs was at their place of employment. Consent forms were completed on the day of the interview after any questions had been answered. Ethical approval was granted by the University College London Ethics Committee (Reference: 3578/001) on 24th January 2012.
|
study
| 100.0 |
Our preliminary topic guide was informed by emergent findings from a rapid literature review, workshops with health and social care professionals, carers and people with early dementia, and by information from an ongoing cohort study within the research programme (Sampson et al., 2016). We sought to explore service personnel’s recognition of dementia as a life-limiting illness, the management of acute medical problems, appropriateness of hospitalisation, the role of advance care plans and do not attempt resuscitation orders and HCPs views of where the health and social care system is failing to meet the needs of people with advanced dementia and their families. The researchers used emerging information to explore significant and unanticipated issues in later interviews.
|
study
| 99.94 |
All interviews were audiotaped, transcribed and entered onto a qualitative software programme (Atlas-ti) for coding, management and retrieval of data. To ensure accuracy, two researchers checked the transcripts with the audio recordings. Transcripts were initially read several times to achieve familiarisation with the data. We analysed and coded the transcripts using thematic analysis as described by Braun and Clarke (2006). Units of text were broken down into categories to develop appropriate codes which were then grouped together to form themes. We used an iterative process to ensure that each unit of text was assigned to the correct code(s) and theme(s) as new categories emerged. For rigour and transparency, we used memos and reflective diaries. A third researcher reviewed three randomly selected interviews, and any differences in the coding framework were resolved through discussion. Minor grammatical errors in quotes have been corrected to facilitate comprehension.
|
study
| 99.8 |
We interviewed 14 HCPs between September 2012 and October 2013. Respondents included three health-care assistants, one nurse, one clinical nurse manager, one clinical manager (manages a memory clinic service in an NHS-based organisation), two care home managers, one admiral nurse lead (specialist dementia nurse), one mental health nurse, one specialist mental health nurse and one occupational therapist. Two commissioners responsible for older adult services within a CCG were interviewed. While the range of experience and length of time in their current role (11 months to 14 years) was variable, all of the respondents were experienced in the health and social care sector. Interviews lasted approximately an hour.
|
study
| 97.56 |
The data revealed three main themes consisting of several sub-themes; (1) social and economic system, (2) care home organisational issues and (3) a fragmented approach to care. A top-down hierarchical structure of how societal attitudes and the governmental system can influence the organisation within care homes and a fragmented approach to care is illustrated in Figure 1. The care home setting and fragmented approach to care also interact reducing the capacity of the care system to meet the end of life care needs of those with advanced dementia. Figure 1.Barriers to integrated care for people with advanced dementia residing in care homes.
|
study
| 99.9 |
The first theme is societal attitudes of older people and how the state develops services and implements policies related to the provision of care for people with dementia. Our data revealed that collectively as a society, we place less value on older people than on younger people, especially those nearing the end of life.That would be like shoving me in a home when I get older and they've got me listening to dance music all the time. It's homogenous kind of 'one size fits all'… There was something like the King's report last year that said in society we're all so focused about the under threes and children, and actually the most vulnerable members in our society are older people, over the age of whatever it was. And I thought, 'Yeah, they are, because they just don't have a voice' (Specialist Mental Health Professional).
|
other
| 99.9 |
That would be like shoving me in a home when I get older and they've got me listening to dance music all the time. It's homogenous kind of 'one size fits all'… There was something like the King's report last year that said in society we're all so focused about the under threes and children, and actually the most vulnerable members in our society are older people, over the age of whatever it was. And I thought, 'Yeah, they are, because they just don't have a voice' (Specialist Mental Health Professional).
|
other
| 99.94 |
The commissioners were focused on issues related to the early stages of dementia rather than care in the later higher dependency stages of dementia.So we have a number of dementia projects, business cases … for example to enhance the memory assessment service, and improve our early intervention and diagnosis … I think what we’re envisioning is some services will be key services … like the day service for people with dementia … a reading group (Commissioner for Older Adults Services).
|
other
| 99.94 |
So we have a number of dementia projects, business cases … for example to enhance the memory assessment service, and improve our early intervention and diagnosis … I think what we’re envisioning is some services will be key services … like the day service for people with dementia … a reading group (Commissioner for Older Adults Services).
|
other
| 99.94 |
There was consensus that UK Government strategy contributes to fragmented care. Limited funding and health and social care system reorganisation have been implemented to reduce costs, hence reducing the financial resources available for timely and coordinated care.
|
other
| 99.94 |
The data highlight a general concern by professionals that care homes are overly influenced by a business model of care, driven by profit rather than optimal care. Care homes can work around equivocal regulations such as the Health and Social Care Act 2008 (Regulated Activities) Regulations 2010 by assigning nurses to provide assistance to health-care assistants when staffing levels are at minimal levels.By law it should be five to one [ratio of care staff to residents]. So the extra five, I chipped in most times to assist. And I work on the floor … [Why do you think you’re understaffed at the moment?] From my experience - its right across the whole country, you never get enough staff in. It’s only, occasionally you might have three carers to support you, but most of the time, the shortness of the adequate personnel is a crisis … Well, I do believe that one of the reasons is cost effectiveness. Not cost effectiveness - it’s got to do with finance. Not finance in the sense that, it’s [care homes] a profit making organisation, that doesn’t make it easy. And the less staff you get to carry out the task, the more profit you make (Mental Health Nurse).
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other
| 99.9 |
By law it should be five to one [ratio of care staff to residents]. So the extra five, I chipped in most times to assist. And I work on the floor … [Why do you think you’re understaffed at the moment?] From my experience - its right across the whole country, you never get enough staff in. It’s only, occasionally you might have three carers to support you, but most of the time, the shortness of the adequate personnel is a crisis … Well, I do believe that one of the reasons is cost effectiveness. Not cost effectiveness - it’s got to do with finance. Not finance in the sense that, it’s [care homes] a profit making organisation, that doesn’t make it easy. And the less staff you get to carry out the task, the more profit you make (Mental Health Nurse).
|
other
| 99.9 |
The physical layout of the care home may hinder the provision of good quality care. Many care homes are arranged so that people with different levels of need are housed on different floors of the building. Staff are required to work across these settings and the focus of their tasks may vary. Having staff consistently assigned to one floor was seen as promoting continuous care both to people with dementia and their families and enabled professional carers to adopt a more personalised approach.I don’t know how confident the care home staff would have been to do it [make referrals] and also they changed on a daily basis, that was the biggest,… not the staff in the home but the floor that they worked on, yeah. So like you’d go do a ward round with (Doctor) and you’d sit there and you’d say ‘so how’s blah, blah been this week?’ and they’ll say ‘well I worked downstairs for the last five days then I had two days off’ and it would be like well what, you know we did say ‘please can you try and keep the same staff on the same floors’ and then you’d have RMN’s (Registered Mental Nurse) that worked on the middle floor which was more sort of general nursing and you would have an RGN (Registered General Nurse) on the bottom floor which was more psychiatric. There didn’t seem to be any consistency to be honest (Clinical Manager).
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other
| 99.9 |
I don’t know how confident the care home staff would have been to do it [make referrals] and also they changed on a daily basis, that was the biggest,… not the staff in the home but the floor that they worked on, yeah. So like you’d go do a ward round with (Doctor) and you’d sit there and you’d say ‘so how’s blah, blah been this week?’ and they’ll say ‘well I worked downstairs for the last five days then I had two days off’ and it would be like well what, you know we did say ‘please can you try and keep the same staff on the same floors’ and then you’d have RMN’s (Registered Mental Nurse) that worked on the middle floor which was more sort of general nursing and you would have an RGN (Registered General Nurse) on the bottom floor which was more psychiatric. There didn’t seem to be any consistency to be honest (Clinical Manager).
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other
| 99.94 |
A strongly held view was that care homes were ill-equipped to provide adequate end of life care for residents with dementia. Due to the profit-driven nature of care homes, respondents reported that staffing levels were poor, and staff turnover was high due to limited professional development opportunities, demanding workloads, low pay and low job satisfaction resulting in high levels of role burden. Low availability of both trained and untrained staff resulted in demanding and stressful workloads forcing many staff to accept multiple responsibilities.The workload also is extremely high for a nurse, for example the average amount of medications that a care home resident might be on may be 10, and that’s three times a day, they have to be given it at a certain time, the GP’s coming, the social worker’s doing a review, there’s a new admission, there’s a transfer, there’s a death, multiple, multiple things are happening at the same time that the nurse has to literally split herself in a hundred (Care Home Manager).The less staff you get to carry out the task, the more profit you make … you get disgruntled. Why should I stretch myself etc … not that you don’t to want stretch yourself, but the impact of working endlessly has got a detrimental effect on your morale, output (Mental Health Nurse).
|
other
| 99.9 |
The workload also is extremely high for a nurse, for example the average amount of medications that a care home resident might be on may be 10, and that’s three times a day, they have to be given it at a certain time, the GP’s coming, the social worker’s doing a review, there’s a new admission, there’s a transfer, there’s a death, multiple, multiple things are happening at the same time that the nurse has to literally split herself in a hundred (Care Home Manager).
|
other
| 99.9 |
The less staff you get to carry out the task, the more profit you make … you get disgruntled. Why should I stretch myself etc … not that you don’t to want stretch yourself, but the impact of working endlessly has got a detrimental effect on your morale, output (Mental Health Nurse).
|
other
| 99.94 |
Care home staff were anxious about increasing governance and scrutiny that did not appear to take account of general working conditions, poor resources, challenging workload and the emotional demand of coping in these settings. Under the Department of Health’s Care Act 2014, safeguarding requires local authorities to make enquiries if abuse or neglect is suspected. Some staff felt that enquiries were sometimes made into issues that were not related to neglect and that the process of being investigated impacted on morale and created a sense of distrust.Everything’s a safeguarding now, the bar is raised very, very high and we don’t see it as a negative, it is stressful when it happens in your home because you own your home and its, you think it’s a reflection on your home, and I think, I think the reason why it’s so stressful is that the social services raise safeguarding and then investigate … it’s not safeguarding if they didn’t change me within 5 or 10 minutes; it’s not a safeguarding. These are issues that we learn from. But already the flags are there, CQC (Care Quality Commission) is notified, and everything, everybody’s aware, and it just has a negative impact on the care in itself … It does have an impact. It does have an impact on morale (Care Home Manager).
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other
| 99.9 |
Everything’s a safeguarding now, the bar is raised very, very high and we don’t see it as a negative, it is stressful when it happens in your home because you own your home and its, you think it’s a reflection on your home, and I think, I think the reason why it’s so stressful is that the social services raise safeguarding and then investigate … it’s not safeguarding if they didn’t change me within 5 or 10 minutes; it’s not a safeguarding. These are issues that we learn from. But already the flags are there, CQC (Care Quality Commission) is notified, and everything, everybody’s aware, and it just has a negative impact on the care in itself … It does have an impact. It does have an impact on morale (Care Home Manager).
|
other
| 99.94 |
Respondents reported that the commercial priorities of care homes negatively influenced staff career development leaving a considerable gap in training opportunities. These included training sessions on dementia, documentation completion, compassionate care and pain recognition. However, high staff turnover was a major obstacle to training. Conversely, lack of training may contribute to turnover.[if I could ask you to name a couple of top priorities that you think will improve care for this very vulnerable group of patients, particularly those approaching the end of their life, what do you think you'd say?] Staff - really well trained staff. Really well trained staff. Of all the stuff that you've said, I think that well, well trained staff (Specialist Mental Health Professional).There's such a high turnover of staff at that level [care homes], as you probably know. We have to do it [training] regularly, but we have to do some kind of toolkit which is really train the trainer with the toolkit, champions – it is a real challenge (Commissioner for Older Adults Services).
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other
| 99.9 |
[if I could ask you to name a couple of top priorities that you think will improve care for this very vulnerable group of patients, particularly those approaching the end of their life, what do you think you'd say?] Staff - really well trained staff. Really well trained staff. Of all the stuff that you've said, I think that well, well trained staff (Specialist Mental Health Professional).
|
other
| 99.94 |
There's such a high turnover of staff at that level [care homes], as you probably know. We have to do it [training] regularly, but we have to do some kind of toolkit which is really train the trainer with the toolkit, champions – it is a real challenge (Commissioner for Older Adults Services).
|
other
| 99.94 |
Respondents described how a low-skilled workforce hampered the potential of care home staff to deliver high-quality care resulting in poor symptom recognition and management. Care home staff argued that they were not provided with the training or support from external service providers to recognise and respond to symptoms presented by people with advanced dementia as they approached the end of life.When someone says, ‘Oh, no, she’s not in pain,’ oh please - the nurses - ‘What do you mean she’s not in pain?’ They need to be more educated with dementia, because they can’t cope. There’s certain people that can cope with dementia, and a lot of people can’t cope with dementia. A lot of people do not like working with them, because they can’t cope with them. They don’t know how to respond to them (Health Care Assistant).
|
other
| 99.9 |
When someone says, ‘Oh, no, she’s not in pain,’ oh please - the nurses - ‘What do you mean she’s not in pain?’ They need to be more educated with dementia, because they can’t cope. There’s certain people that can cope with dementia, and a lot of people can’t cope with dementia. A lot of people do not like working with them, because they can’t cope with them. They don’t know how to respond to them (Health Care Assistant).
|
other
| 99.94 |
Some senior care home staff expressed frustration in the lack of motivation of team members and reported a poor uptake of recommendations by other staff. These opinions highlight the low skill base of care home staff, which appears to limit professionalism in role performance leading to problems within teams.Some people will put some things in place but won’t think about everything else and its sort of left to me to do all the referrals and everything else. I’ll say have you done this, have you done that, have you done this, have you done that? (Care Home Manager)
|
other
| 99.94 |
Some people will put some things in place but won’t think about everything else and its sort of left to me to do all the referrals and everything else. I’ll say have you done this, have you done that, have you done this, have you done that? (Care Home Manager)
|
other
| 99.94 |
It was suggested that care home staff appear demotivated in providing residents with anything more than basic care tasks, and consequently are perhaps unable to provide a more personalised and compassionate approach to residents dying with dementia.“This is what I’m saying about carers in general, they won’t motivate their brain. They will do, they will wash, they will clean, they will feed, but not anything in between” (Heath Care Assistant).
|
other
| 99.9 |
Various thematic issues reflected fragmented care resulting from problematic relationships between care home staff and external HCPs. Care home staff contended that their knowledge and experience of caring for residents were under-recognised or devalued by other HCPs. Such issues deepen the apparent lack of trust between care home staff and service providers external to the care home.She’s developed, rapidly developing grade four pressure sores everywhere, we’ve done safe guarding and everything else, she’s not on any analgesic but if you ask her she says she’s not in pain. So did a pain assessment day before, did one again yesterday and our GP was on holiday until today so trying to speak to another GP its sort of, ‘I want something for pain relief but she won’t take anything orally because she’s refusing all medication’, ‘well if she says not in pain from your pain assessment then I can’t prescribe something’, ‘yes but looking at her, she is in pain but she’s one of these people that sort of keeps quiet’, so it’s more about, I suppose people trusting you (Care Home Manager).
|
other
| 99.9 |
She’s developed, rapidly developing grade four pressure sores everywhere, we’ve done safe guarding and everything else, she’s not on any analgesic but if you ask her she says she’s not in pain. So did a pain assessment day before, did one again yesterday and our GP was on holiday until today so trying to speak to another GP its sort of, ‘I want something for pain relief but she won’t take anything orally because she’s refusing all medication’, ‘well if she says not in pain from your pain assessment then I can’t prescribe something’, ‘yes but looking at her, she is in pain but she’s one of these people that sort of keeps quiet’, so it’s more about, I suppose people trusting you (Care Home Manager).
|
other
| 99.9 |
The processes implemented by care providers external to the care home, for example, lengthy referral processes and lack of advance care planning within primary and secondary care also resulted in uncoordinated and fragmented care.[is it easy to get other HCP in when needed?] It’s not very easy … the social worker is okay, because you have the contact number and you can contact them but if you need the OT [Occupational Therapist] or physio or dietician or any other specialist who come from (Borough of London) reach you just fax over the referral but sometimes they can be very long because they have a long waiting list … And sometimes you need to re fax it to remind them because our report is getting through but they still do not get in contact with us. Sometimes two weeks pass and still nothing … (Nurse).
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other
| 99.9 |
[is it easy to get other HCP in when needed?] It’s not very easy … the social worker is okay, because you have the contact number and you can contact them but if you need the OT [Occupational Therapist] or physio or dietician or any other specialist who come from (Borough of London) reach you just fax over the referral but sometimes they can be very long because they have a long waiting list … And sometimes you need to re fax it to remind them because our report is getting through but they still do not get in contact with us. Sometimes two weeks pass and still nothing … (Nurse).
|
other
| 99.94 |
Information sharing was described as at its weakest when people with dementia were transferred between services, such as to hospital. In the quote below, a clinical manager laments the poor communication and the ill-defined responsibility when a patient is transferred to a care home from a psychiatric ward.There’s absolutely zero information about the history and even the GP doesn’t have it either, you know, which I think is terrible. Yeah … Just crap communication yeah. And it’s up to the ward to ensure that information is, or although maybe it’s up to the placement officer, whoever decides on placing them to get that information but they’ve probably not got it either (Clinical Manager).
|
other
| 99.9 |
There’s absolutely zero information about the history and even the GP doesn’t have it either, you know, which I think is terrible. Yeah … Just crap communication yeah. And it’s up to the ward to ensure that information is, or although maybe it’s up to the placement officer, whoever decides on placing them to get that information but they’ve probably not got it either (Clinical Manager).
|
other
| 99.94 |
Care home staff described how hospital staff did not understand the nature and challenges that are faced by care homes. In the following quote, a care home manager points to ethical and procedural differences between residential care and hospital care, suggesting that residential care is negatively vilified. Again, such feelings are likely to result in further demoralisation in this sector and reduce integration of care.When they go to the hospital from here, they always have a UTI, they’re always dehydrated, they have faecal impaction … And it’s ALWAYS, look that’s what’s happened, dehydrated. But none of this is true. What they [hospital staff] don’t understand is that we don’t force care here on anyone, for any reason whatsoever. We don’t restrain, we don’t restrain physically, chemically, we don’t put people in recliners that they can’t get up out of, that’s a restraint, we don’t open people’s mouths and give medication if they’re spitting it out, we don’t put fluids in people’s mouths if they don’t want to drink, the same thing with food, ok, and we have a balance that we, this is one of the stresses of the job in that when we admit somebody, and decide that we’re going to care for that person, we have a duty of care. We also on the other hand have to balance that with the person’s right to refuse … and I think, not just the hospital but I believe, social workers need to come in to care homes and I think they need to see for themselves what happens in care homes (Care Home Manager).
|
other
| 99.9 |
When they go to the hospital from here, they always have a UTI, they’re always dehydrated, they have faecal impaction … And it’s ALWAYS, look that’s what’s happened, dehydrated. But none of this is true. What they [hospital staff] don’t understand is that we don’t force care here on anyone, for any reason whatsoever. We don’t restrain, we don’t restrain physically, chemically, we don’t put people in recliners that they can’t get up out of, that’s a restraint, we don’t open people’s mouths and give medication if they’re spitting it out, we don’t put fluids in people’s mouths if they don’t want to drink, the same thing with food, ok, and we have a balance that we, this is one of the stresses of the job in that when we admit somebody, and decide that we’re going to care for that person, we have a duty of care. We also on the other hand have to balance that with the person’s right to refuse … and I think, not just the hospital but I believe, social workers need to come in to care homes and I think they need to see for themselves what happens in care homes (Care Home Manager).
|
other
| 99.9 |
NHS-based services such as hospitals were described as having access to specialist resources and working in multidisciplinary teams in comparison to care home staff who work independently of other service providers.“they [care home staff] work independently whereas in the hospital, if there’s a problem, call the doctor, call the physio” (Care Home Manager).
|
other
| 99.9 |
HCPs reported that they worked in silos, which hindered the development of an integrated care approach.I still think there is, you know, they [HCPs] do work really well, but they do tend to work in silos, everybody still does work in silos. And it does need to be a bit more integrated. So integrated in terms of providers, and integrated across the pathway (Commissioner for Older Adults Services).
|
other
| 99.9 |
I still think there is, you know, they [HCPs] do work really well, but they do tend to work in silos, everybody still does work in silos. And it does need to be a bit more integrated. So integrated in terms of providers, and integrated across the pathway (Commissioner for Older Adults Services).
|
other
| 99.94 |
There was an element of diffused responsibility amongst providers of care for those with advanced dementia. Each expert is expected to provide care when their specialist advice is sought but a single health-care provider rarely takes overall responsibility for the health and well-being of those living in care homes.We’ve got a single point of contact in this area so we’d refer via the single point of contact. For dieticians, and speech and language therapy we’ve got a form we fax off to the department. For palliative care we have to go through the GP and for podiatry we have to go through the GP (Care Home Manager).
|
other
| 99.94 |
We’ve got a single point of contact in this area so we’d refer via the single point of contact. For dieticians, and speech and language therapy we’ve got a form we fax off to the department. For palliative care we have to go through the GP and for podiatry we have to go through the GP (Care Home Manager).
|
other
| 99.94 |
To our knowledge, this is the first study to explore the barriers to providing integrated care to those with advanced dementia in care homes incorporating both HCPs working within and external to care homes. Given the growing population of people with dementia (Prince, et al., 2015) and that the majority of people with advanced dementia die in long-term care institutions (Sleeman et al., 2014), understanding and addressing the barriers to providing integrated care are critical. Our data suggest that three main factors hinder the development of an integrated approach to palliative care for those with advanced dementia: societal attitudes and governmental policy, the care home organisation and a fragmented approach to care. Within a youth-focused society, services for older people are given less emphasis and dementia care policy initiatives focus on assessment and the earlier phases of dementia.
|
study
| 99.9 |
Care home staff experience high role burden associated with demanding working conditions, very low pay and limited professional development opportunities. Our findings illustrate poor communication and conflictive relationships between HCPs and service settings, poor symptom management, lengthy referral processes, inter-agency ignorance, diffused responsibility amongst care providers and minimal care planning. These factors result in a fragmented rather than integrated approach to care.
|
other
| 99.75 |
Some of these findings are not unique to our study. Previous research highlights that tensions arise when other HCPs do not recognise that care home staff are familiar with their residents (Gage et al., 2012) and found disagreements regarding service responsibility (Jha, 2008). Limited professional development opportunities and low pay for formal carers in this sector are prevalent in countries other than the UK (Forbes & Neufeld, 2008). However, comparative work suggested that whilst health and social care services in the UK presented poor integration, care providers in the Netherlands functioned within collaborative networks (Kumpers, Mur, Hardy, van Raak, & Maarse, 2006). In addition, nursing homes in the UK have adopted a social care approach, whilst the Netherlands draws from a medical care model, thus enabling continuous access to doctors and other medical expert care for people with advanced dementia (Kumpers, Mur, Maarse, & van Raak, 2005) albeit at the cost of social needs.
|
study
| 99.9 |
The crucial need for integrated care, especially for those with advanced dementia has been highlighted by researchers in the US (Shega et al., 2003). Provision of proactive and integrated palliative care for people living with dementia in the community resulted in the rapid detection and management of symptoms and an increase in hospice referrals (Shega et al., 2003). Similarly, multidisciplinary teams caring for those with dementia score higher on quality indicators such as assessment and care planning, integration and provision of specialist care when compared with single health or social disciplines. However, the level of integration was not consistent across all multidisciplinary teams (Abendstern, Reilly, Hughes, Venables, & Challis, 2006) suggesting that coordinated care depends on individual teams at local levels. Similarly, UK studies indicate that collaboration at a local level is patchy and vulnerable to breakdown due to high staff turnover (Dening, Greenish, Jones, Mandal, & Sampson, 2012; Gage et al., 2012). While specialist palliative care from hospices could provide support to care homes, research shows these services may only be used in response to crises rather than as part of advance planning (Froggatt, Poole, & Hoult, 2002).
|
review
| 99.8 |
Business-driven care homes foster a culture of minimalistic provision of care aimed at meeting basic needs but neglecting, for example social interaction and emotional and spiritual support. A recent review found that these areas are just as important as ensuring that the physical needs of those at the end of life are fulfilled (Perrar, Schmidt, Eisenmann, Cremer, & Voltz, 2015).
|
review
| 99.9 |
Lack of professional development opportunities for care home staff also contributes to the cycle of poor provision of fragmented care. A recent review highlighted that providing structured training programmes to formal carers working in care homes can improve behavioural problems presented by people with dementia and reduce the use of antipsychotic medication (Fossey et al., 2014). Integration of care should be available continuously throughout the disease and not just at the diagnostic stage (Bullock, Iliffe, & Passmore, 2007; McNulty, Jackson, & Pelosi, 2008).
|
review
| 99.9 |
Our study has a number of strengths including the recruitment of commissioners and HCPs from a variety of services, the collection of rich data from in-depth interactive interviews and the use of triangulation and consensus meetings to verify the credibility of the data. Our realist approach to developing the topic guide informed by our findings from the other components of the programme ensured that the interviews addressed issues that were emerging directly from our work with services.
|
study
| 96.94 |
Although the study did not aim to be representative of all HCPs, data were collected from HCPs working in care homes and those providing care to care homes in the South East of England. However, these attitudes may not be applicable to other HCPs such as general practitioners and allied health professionals and those working in other areas of the UK or in other countries. Finally, an integrated approach to providing end of life care for people with advanced dementia requires collaboration between care providers and family carers. Although it is a limitation that we have not included family carers perspectives, we did seek their views on this topic and hope to publish these findings separately.
|
study
| 99.9 |
Our findings have implications for research, policy and practice. They support two of the top 10 research priorities for care at the end of life identified by the Palliative and end of life care Priority Setting Partnership (PeolcPSP) (2015) which worked in consultation with people with dementia, their family carers and HCPs providing care for those with palliative care needs. This report stresses the need for training to be provided to HCPs delivering palliative care and research to develop a continuous model of care.
|
other
| 95.44 |
We suggest that integration of care would be developed by modifying structural factors and the network of services that currently function as separate entities when providing care for people with dementia. The Better Care Fund (National Health Service (NHS) England, 2013) proposed by the UK Government could help reduce the fragmentation in the provision of good end of life care for those with dementia, for example, by developing networks and shared referral pathways to foster improved relationships between health and social care providers.
|
other
| 99.9 |
Our finding that care homes operate on minimal staffing levels is not surprising as the Health and Social Care Act 2008 (Regulated Activities) Regulations 2010 is open to interpretation stating that care services must employ “sufficient numbers of suitably qualified, skilled and experienced persons.” This should be replaced with definitive recommendations on the optimal ratio of HCPs to residents in care homes to ensure good care. In addition, good practice could be incentivised by rewarding care homes who adhere to such recommendations as part of standard practice.
|
other
| 99.94 |
Care of people with dementia who are approaching death may be enabled by an integrated approach that includes improving the communication and relationships between all care providers and creating multidisciplinary teams who draw on each other’s knowledge to provide optimal care. For this, a top-down approach from policy makers is required so that the funding and resources are available to develop leaders in this field who will motivate all care providers to work together at local level. Successful development of an integrated model could result in an environment and culture where older people are more valued and cared for by a proactive, collaborative team of experts who provide health and social care.
|
other
| 99.9 |
The environmental safety assessment of nanomaterials has long been investigated by many scientists and a number of studies have been conducted to investigate the effects of nanomaterials on environmental microorganisms. For instance, Lyon et al. have shown that C60 in powder form had no impact on bacteria while an aqueous suspension of C60 generated toxic effects . Li et al. have also demonstrated that carbon nanotubes showed antimicrobial activity on the studied bacterial strains . Some researchers found that graphene could damage the cell membrane of Escherichia coli (E. coli) and thereby, showed strong antibacterial activity .
|
review
| 99.56 |
Molybdenum disulfide (MoS2) has a graphene-like structure, which is a typical layered crystal, and consists of sulfur (S) and molybdenum (Mo) atoms, with individual layers bound to each other by van der Waals forces . MoS2 possesses excellent biocompatibility, strong visible light absorption, fluorescence quenching characteristics and a number of other interesting properties [6–8]. Due to these distinct electronic and physical/chemical properties, MoS2 has wide applications in many fields, such as opto-electronics, channel materials, biomedicine and dry lubrication [9–13]. Since ultrathin MoS2 shows much more attractive properties compared with bulk MoS2, large efforts have been made to develop methods for growing high quality ultrathin MoS2 films on various substrates. However, traditional top-down methods such as mechanical or chemical exfoliation are not suitable for the fabrication of large area, high-quality ultrathin MoS2 films [14–16]. Fortunately, MoS2 monolayers have been successfully grown on SiO2/Si substrates by chemical vapor deposition (CVD) . Moreover, pulsed laser deposition (PLD) also showed great potential for growing monolayer and thin multi-layer MoS2 films .
|
review
| 99.75 |
Since MoS2 has a layered structure, the properties of MoS2 thin films are significantly linked to the number of their layers . For example, the in-plane stiffness and breaking strength of monolayer MoS2 is higher than that of bulk MoS2 crystals . When the number of the MoS2 layers increases, the inter-layer van der Waals forces within MoS2 start to significantly suppress vibrations, which is the main reason why bulk MoS2 has a higher restoring force than monolayer MoS2 . Bulk MoS2 is a semiconductor material with an indirect band gap of 1.2 eV, and is often used as a photocatalyst, but also as a dry lubricant. A monolayer of MoS2, on the other hand, has a 1.9 eV direct band gap and possesses prominent electro- and photoluminescent properties . Moreover, it is generally believed that the toxicity of 2D layered MoS2 depends on its defect density, exfoliation parameters and chemical composition . Since the layer number can affect the surface area, defects and edge parameters of the MoS2 nanosheets, it has been found that the toxicity of MoS2 nanosheets increased with decreasing layer number .
|
study
| 100.0 |
Due to the increasingly broad application of MoS2, the opportunities for MoS2 to be released to the environment and thus come in contact with environmental microorganisms will likely only increase in the future. Therefore, assessing the effects of MoS2 on microbial communities has become increasingly urgent and some efforts have already been made towards this goal. For example, Nilam and co-workers discovered that the graphene-like molybdenum disulfide nanosheets (MSNs) possessed antibacterial properties on E. coli and B. subtilis, by measuring reactive oxygen species (ROS) and morphological observation . Marek Kostecki et al. have demonstrated that MSNs have antibacterial and antifungal properties by SEM observation . These preliminary experiments gave new insights useful for assessing the microbial toxicity of MoS2. However, an in-depth mechanistic explanation for how MoS2 affects microbial cells is still needed.
|
study
| 99.8 |
In fact, changes in microbial metabolites can directly reflect microbial responses to environmental stimuli. Metabolomics technology as a new set of tools has been widely used in the evaluation of the toxicity of nanomaterials . For instance, Zhao et al. utilized gas chromatography-mass spectrometry (GC-MS) based on metabolomics to evaluate the toxicity of copper nanoparticles . Ratnasekhar et al. used metabolomics to study the perturbations in the metabolome of Caenorhabditis elegans exposed to titanium dioxide nanoparticles .
|
review
| 99.7 |
Taken together, these observations have inspired the present work, in which gas chromatography-mass spectrometry (GC-MS), metabolomics technology and other molecular biology approaches have been employed to unveil the mechanism of how MoS2 nanosheets affect the important model bacterium E. coli.
|
study
| 99.94 |
The MoS2 nanosheets used in this study were purchased from Sigma-Aldrich (99.995%, Sigma-Aldrich, St. Louis, USA). According to the method reported previously , field emission scanning electron microscopy combined with energy dispersive spectrometry (FE-SEM, Hitachi S-4800) was utilized to determine the surface morphology and relative abundance of chemical elements of the MoS2 samples. In addition, the MoS2 samples were analyzed using a HR800 Raman Microscope (Horiba Jobin Yvon, France) and focalized using a 40 × objective with an excitation wavelength of 514 nm, adjusting the exposure time to acquire the correct spectrum.
|
study
| 100.0 |
We used E. coli MG1655 as a model bacterium to evaluate the antibacterial activity of MoS2 nanosheets (MSNs), and the strain was kindly provided by the group of Prof. Guoqiang Chen (School of Life Sciences, Tsinghua University, China). E. coli was maintained on Luria Bertani (LB) liquid medium containing 10 g/L tryptone (OXIOD, UK), 5 g/L yeast extract (OXIOD, UK) and 5 g/L NaCl, with pH set to 7.0, at 37°C under constant orbital shaking at 220 rpm for up to 12 h. The LB liquid medium was supplemented with MSNs at concentrations of 0, 1, 10, 100 and 1000 μg/mL. For fermentation, 5% v/v aliquots of seed culture were used to inoculate 50 mL fermentation media containing 10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl and 15 g/L glucose, which were subsequently incubated at 37°C under constant orbital shaking at 220 rpm for a further 12 h.
|
study
| 100.0 |
E. coli was cultured in LB media with 0, 1, 10, 100, or 1000 μg/mL of MSNs. Sampling was carried out at 2 h intervals during the course of 12 h of fermentation. Cell growth was determined by measuring the optical density at 600 nm (Lambda-25 spectrophotometer, Perkin-Elmer, USA) in six parallel measurements for each time-point.
|
study
| 99.94 |
Methylthiazolyldiphenyl-tetrazolium bromide (MTT) reagent (Sigma-Aldrich, USA) was used for cell viability measurements. E. coli was exposed to 0, 1, 10, 100, or 1000 μg/mL of MSNs in PBS (pH 7.0). Subsequently, the cells were incubated in PBS at 37°C under constant orbital shaking at 220 rpm for 6 h, after which 20 μL PBS solution containing cells, 20 μL MTT solution (1 mg/mL) and 60 μL fresh PBS were transferred into an Eppendorf tube and incubated in a thermostat water bath for 30 min at 37°C. Subsequently, the tube was centrifuged at 10000 g for 5 min and the supernatant removed. 300 μL dimethyl sulfoxide (DMSO) was added to each tube to dissolve the sediment and the tubes were centrifuged at 10000 g for another 5 min. The supernatants were transferred to 96-well plates and the absorbance at 490 nm was measured using a plate-reader (Molecular Devices, SpectraMax M3, USA). The results are expressed as the means ± SD of six parallel measurements.
|
study
| 100.0 |
E. coli was exposed to 0, 1, 10, 100, or 1000 μg/mL of MSNs in PBS (pH 7.0). Subsequently, the cells were incubated in PBS at 37°C under constant orbital shaking at 220 rpm for 6 h, after which the cells were separated by centrifugation at 4000 rpm for 5 min and the supernatants transferred into 96-well plates. Lactate dehydrogenase (LDH) activity was determined using a lactate dehydrogenase kit (Sigma-Aldrich, USA), according to the manufacturer’s protocol, with final detection of absorption at 450 nm using a Lambda-25 plate reader (Perkin-Elmer, USA). The results are expressed as the means ± SD of six parallel measurements.
|
study
| 100.0 |
2,7-Dichlorodihydrofluorescein diacetate (DCFH-DA) (Sigma-Aldrich, USA) was added to 50 mL LB media as a 10mM stock in DMSO, and incubated at 37°C under constant orbital shaking at 220 rpm for 20 min, after which the cells were washed twice with PBS and dispersed in PBS solutions containing 0, 1, 10, 100, or 1000 μg/mL of MSNs. Subsequently, the PBS solutions containing the cells and the MSNs were incubated at 37°C under shaking at 220 rpm for another 4 h, after which the PBS supernatants were transferred into the wells of a 96-well plate and evaluated on a fluorescent spectrophotometer (SpectraMax M3, Molecular Devices, USA) using an excitation wavelength of 488 nm and an emission wavelength of 525 nm. The results are expressed as the means ± SD of six parallel measurements.
|
study
| 99.94 |
After 12 h of incubation at 37°C under shaking at 220 rpm, the cells were collected by centrifugation at 8000 rpm and 5°C for 5 min. The pellets were re-suspended in 25% glutaraldehyde and fixed for 12 h, after which the cells were washed with PBS three times. 2% Osmium tetroxide (OsO4) was added to the pellets and contacted for 1 h on a sample rotator. The cells were dewatered by subsequent rinses with solutions comprising 35%, 50%, 70%, 90% and 95% ethanol, followed by a final rinse in absolute ethanol. After contacting with propylene oxide for 30 min, propylene oxide/resin (Meryer, China) (1:1) was added and allowed to react for 12 h at 45°C. Finally, the cells were embedded in 100% resin and polymerization was conducted in an oven at 70°C for 24 h, after which the samples were prepared as 90 nm sections using an EM UC6 Ultramicrotome (Leica, Germany). After staining with 3% uranyl acetate and lead citrate (Beijing chemical works, China) for double staining, the sections were examined under a JEM-1011 transmission electron microscope (JEOL, Japan).
|
study
| 99.94 |
Media samples were collected by centrifugation at 5000 rpm for 8 min at -20°C. The supernatant was removed and 1.5 mL of ice-cold (-20°C) 60% methanol was added to the pellets to terminate metabolic activity. The mixtures were transferred into 2 mL pre-weighted Eppendorf tubes, and each tube frozen and thawed five times in liquid nitrogen and subsequently centrifuged at 15000 rpm and -20°C for 15 min. The supernatants were stored at -80°C. The remaining materials were suspended in 1 mL of ice-cold (-20°C) 60% methanol in water and centrifuged same as above. Subsequently, the resulting supernatant was mixed with the first supernatant and carefully transferred into a 1.5 mL Eppendorf tube, after which 10 μL of a 0.2 mg/mL ribitol (Sigma-Aldrich, USA) solution was added as internal standard and the samples dried under nitrogen gas. The dried samples were mixed with 50 μL methoxylamine hydrochloride /pyridine (20 mg/mL) (Sigma-Aldrich, USA) and incubated in a water bath at 37°C for 80 min. The compounds were blended with 80 μL MSTFA (N-Methyl-N-(trimethylsilyl) trifluoroacetamide) (Sigma-Aldrich, USA) and incubated in a water bath at 37°C for 80 min, after which the samples were centrifuged at 10000 g for 5 min and a 100 μL aliquot of the supernatant transferred to a fresh Eppendorf tube and used directly for GC-TOF/MS detection on a gas chromatograph-mass spectrometer (Trace GC2000 DSQ, Agilent, USA).
|
study
| 99.94 |
AMDIS software (NIST, v2.69, Gaithersburg, MD, USA) coupled with MSD Chemstation software (Agilent Technologies, G1701 EAE.02.00.493, USA) was used for the qualitative and quantitative analysis of mass spectrometry data. MSD software was used to integrate the peak areas. Each peak was qualitatively analyzed in the chromatograms. The spectral libraries used mainly contained data from NIST 2005 and Wiley. All peak areas were normalized for further data processing and imported into Expander (version 6.0) software for cluster analysis. According to a method reported earlier , metabolite data displaying significant changes were imported into MetaboAnalyst3.0 for enrichment analysis and pathway analysis. Pathways with an impact value >0.2 were considered to be significantly affected.
|
study
| 99.94 |
As shown in Fig 1A and 1B, MoS2 nanosheets (MSNs) were found to present as flower-like flakes that showed a layered crystal structure. It has been reported that MSNs seemed to become transparent when the layer number decreased, since the MSNs became thin enough for light to pass through . Herein, we also found that some parts of the bulk MSNs looked transparent (Fig 1A and 1B, indicated with red circles and arrows), since some of the MSN flakes were very thin. We further characterized the chemical components of the MSNs we used. The EDS results indicated that the MoS2 samples only contained sulfur and molybdenum atoms without any significant impurities (see Fig 1C and S1 Table). Raman spectroscopy has been widely applied to characterize the structural properties of MSNs and it has been possible to determine the number of layers, as the vibrational spectrum is sensitive to sample thickness and by inference, to the number of layers . In our work, the MSNs were thus further characterized by Raman spectroscopy (Fig 1D). As shown in Fig 1D, the Raman spectrum of the MSNs had two prominent peaks (383 cm-1 and 409 cm-1), corresponding to the in-plane (E12g) mode and the out-of-plane (A1g) mode, respectively . The spacing between the E12g and A1g modes was about 26 cm-1, which suggested that the used MSNs were composed of bulk MoS2 [14, 33].
|
study
| 100.0 |
To explore the influence of MSNs on the growth of E. coli, cells were incubated in broth with a series of MSNs concentrations (0, 1, 10, 100, 1000 μg/mL). As shown in Fig 2, the OD values of cultures grown in broth with the addition of 1, 10 or 100 μg/mL of MSNs seemed similar to that of the control. However, the growth curves of E. coli became unstable when the concentration of MSNs increased to 1000 μg/mL. Hence, these results indicated that MSNs with a concentration of no more than 100 μg/mL had no remarkable impact on the growth of E. coli. However, when 1000 μg/mL of MSNs was added to the broth, OD values were lower than the other groups and decreased significantly after 4 h, which indicated that a high concentration of MSNs could significantly inhibit the growth of E. coli.
|
study
| 100.0 |
We further investigated the viability of E. coli cells exposed to different concentrations of MSNs. Fig 3 illustrates that the experimental groups contacted with different dosages of MSNs showed a slight and dose-dependent inhibition of viability. These findings were consistent with other published work, which reported that MoS2 showed mild direct cytotoxicity . In our experiment, E. coli was cultured in aqueous solution in shake flasks and we hypothesized that the low observed toxicity might be attributed to the very low solubility of MSNs.
|
study
| 100.0 |
Nano-materials can be damaging to cells, mainly due to damage to cell membranes and the induction of oxidative stress as discussed in previous reports . The excessive accumulation of reactive oxygen species (ROS) can damage the cell membrane and reduce its stability. In this regard, lactate dehydrogenase (LDH) is a vital indicator which can be used as a proxy for oxidative damage to the cell membrane . Therefore, we evaluated LDH release and ROS accumulation to investigate the impact of MSNs on cell membrane stability in E. coli.
|
study
| 100.0 |
Our experimental observations showed that when E. coli was exposed to MSNs, LDH release increased compared to the control. Fig 4A shows that the LDH release was increased by 8.1%, 13.1%, 16.3% and 17.6% at MSNs concentrations of 1, 10, 100 and 1000 μg/mL, respectively. Tu et al. used computer simulation to model the impairment of cell membranes caused by graphene nanosheets. They demonstrated that both graphene nanosheets and graphene oxide nanosheets could insert into E. coli membranes. This phenomenon explains how graphene nanosheets and graphene oxide nanosheets could generate obvious membrane stress and reduce cell viability of E. coli . The increase of LDH release may be caused by interactions between the MSNs and the surface of the E. coli cell membrane, which in turn might reduce membrane stability and the resistance of E. coli to external substances. MSNs can penetrate cell walls and expose the cell membrane, which decreases its stability. Finally, the amount of LDH apparently increased in this bacterium.
|
study
| 100.0 |
It is well known that ROS are generated on the surface of nano-materials, which further induces the cells to generate more ROS . ROS generation is a cumulative process, whereby only reaching a certain value of damage can cause significant permanent intracellular oxidative damage. We further investigated the influence of MSNs on intracellular ROS after exposing E. coli to different doses of MSNs. As shown in Fig 4B, when the concentrations of MSNs were in the range of 1–100 μg/mL, the levels of ROS in E. coli increased only slightly. On the other hand, MSN concentrations in the range of 100–1000 μg/mL caused the generation of significant amounts of ROS. These results indicated that MSNs, just like other nanomaterials such as fullerene, graphene and its derivatives, could cause an increase of intracellular ROS, which might finally cause damage to the cells [42–44]. Nel et al. did a considerable amount of work on the toxicity of nanomaterials and found that the generation of ROS might be associated with surface defects, electron—hole pair generation, chemical dissolution and release of toxic metal ions from nanomaterials . Judging by the SEM images (Fig 1D), we also found that the MSNs possessed surface defects, and we thus speculated that MSNs could catalyze ROS formation due to their discrete crystal planes and surface defects, which can result in the production of active electrons on their surface. The next reaction step might be that the excited electrons turned oxygen molecules into superoxide anions (O2.-), which eventually generated further ROS via disproportionation .
|
study
| 100.0 |
When E. coli was cultured without the addition of MSNs, the cells showed a long and tubular form, and the cell membrane was relatively intact. Some of the cells were found to be shrunken (see Fig 5A and 5B). When E. coli was exposed to low doses of MSNs (1, 10 μg/mL), some cells that changed in cell structure were found (Fig 5C–5F). On the other hand, when E. coli was exposed to high doses of MSNs (100, 1000 μg/mL), some of the cells were also found to be shrunk and their cell membranes appeared to be broken (Fig 5G–5J). These results suggested that MSNs affected the cellular structure of E. coli in a dose-depended manner, which was similar to the observations reported for other nanomaterials . In order to quantify the TEM results, the percentage of shrunken cells was calculated by counting the shrunken E. coli cells in the TEM images. We found that the percentages of shrunken cells were 8%, 12%, 13%, 14% and 16% when the E. coli were treated with 0, 1, 10, 100 and 1000 μg/mL of MSNs, respectively (Fig 6). It was thus found that the percentage of shrunken cells increased slightly when the concentration of MSNs was raised from 0 μg/mL to 1000 μg/mL. This result was in accordance with the results of LDH release and ROS analysis (Fig 4A and 4B). We hypothesized that high doses of MSNs damaged the cellular structure of E. coli, which caused increased LDH release. Moreover, high concentrations of MSNs stimulated the production of high levels of ROS, which would in turn further damage the cellular components.
|
study
| 100.0 |
Using GC-MS, we evaluated the differences in the metabolic profiles of E. coli cells exposed to different concentrations of MSNs relative to the untreated control group. A total of 51 metabolites were filtered out, including amino acids, esters, organic acids, sugars, alcohols, amines, long chain fatty acids and phosphate compounds (Fig 7).
|
study
| 100.0 |
As shown in Fig 7, various metabolites were influenced by exposure of the cells to MSNs. Interestingly, most of these metabolic changes were already induced by low concentrations of MSNs (1, 10 μg/mL) while they were suppressed by high concentrations (100, 1000 μg/mL). For instance, the contents of amino acids, phosphoric acid, and tricarboxylic acid cycle-related metabolites increased or decreased when E. coli was exposed to low (1, 10 μg/mL), or high (100, 1000 μg/mL) concentrations of MSNs, respectively.
|
study
| 100.0 |
The amino acid metabolism is particularly sensitive to environmental disturbances. Li et al. reported that environmental disturbances to microorganisms might result in increased levels of intracellular amino acids caused by the degradation of abnormal, misfolded proteins. Afterwards, the microorganisms would re-synthesize correctly folded proteins to maintain their normal functions in adverse circumstances. However, if adverse circumstances exerted a negative pressure so severe that the microbes could not withstand them, the cells would stop synthesizing proteins and the concentration of intracellular amino acids would decrease . Phosphoric acid on the other hand, is not only a vital component of the phospholipid bilayer, but also acts as an activator for a number of protein kinases that regulate important signal transduction pathways and make the cells induce stress responses against adverse environmental conditions . Therefore, the changes in the content of amino acids and free phosphoric acid shown in Fig 7 might be caused by stress mechanisms intrinsic to the microorganism. When exposed to low concentrations of MSNs, E. coli would resist adverse environmental conditions by producing more amino acids and accumulating free phosphoric acid, whereas high dosages of MSNs, which might exceed the tolerance range of E. coli, would result in degradation of amino acids and decrease of free phosphoric acid.
|
study
| 100.0 |
The tricarboxylic acid (TCA) cycle, also known as the citric acid cycle, is a series of enzyme-catalyzed chemical reactions which occur in many bacteria. The contents of tricarboxylic acid cycle-related metabolites (e.g. lactate, 4-hydroxybutyrate, succinate, glycine) showed a similar change to the changes of amino acids. This result suggested that the metabolic fluxes in the TCA cycle were increased when E. coli was exposed to low concentrations of MSNs, but high dosages of MSNs suppressed the TCA cycle. The levels of metabolites related to the TCA cycle are also decreased under different stress conditions in E. coli .
|
study
| 100.0 |
As shown in Fig 8, when E. coli was exposed to different concentrations of MSNs, the perturbed metabolites were mainly concerned with protein biosynthesis, glycine, serine and threonine metabolism, the urea cycle, phenylalanine and tyrosine metabolism, ammonia recycling, methionine metabolism, and the electron transport chain. Interestingly, four functions, namely protein biosynthesis, glycine, serine and threonine metabolism, urea cycle, and methionine metabolism, were significantly changed in all the experimental groups. These results suggested that MSNs mainly affect protein biosynthesis and the amino acid metabolism of E. coli.
|
study
| 100.0 |
MetPA network tools were utilized to further analyze the effects of different concentrations of MSNs on the metabolic pathways of E. coli. As shown in Fig 9, we found that glycine, serine and threonine metabolism, as well as beta-alanine metabolism, but also the metabolisms of carboxylic acids such as pyruvate and butanoate were all significantly affected by exposure to 1000 μg/mL of MSNs. The pathway analysis results were almost the same as in the ones shown in Fig 9, wherein E. coli was exposed to 1 μg/mL, 10 μg/mL, or 100 μg/mL (S1, S2 and S3 Figs). These results confirmed that MSNs could indeed significantly affect the amino acid-related metabolic pathways. As discussed above, due to stress response mechanisms found in many microorganisms, E. coli might modulate amino acid- or protein-related metabolic pathways to adapt to the adverse environment.
|
study
| 100.0 |
Pyruvate can enter the TCA cycle and serve as a key metabolite for the microbes to maintain normal physiological functions . Wang et al. found that hexavalent chromium exposure suppressed pyruvate metabolism in Shewanella oneidensis . In agreement with this finding, we also found that MSNs significantly affected the pyruvate metabolism, suggesting that MSNs might hamper the normal functions of E. coli by disturbing this important metabolite.
|
study
| 100.0 |
Herein, we used different methods, including metabolomics, to systematically investigate the influence of MSNs on E. coli. Our experimental results showed that high concentrations (100 μg/mL and more) of MSNs caused damage to cell membranes, induced ROS accumulation, and reduced viability. Exposure to low concentrations of MSNs (1, 10 μg/mL) on the other hand, increased the intracellular concentrations of many metabolites in E. coli. Interestingly, exposure to high concentrations of MSNs (100, 1000 μg/mL), conversely, lowered the concentrations of these same metabolites. Metabolomics analysis further revealed that exposure to high concentrations of MSNs could significantly affect several metabolic pathways such as amino acid related metabolism and pyruvate metabolism. These findings provide new insights for assessing MoS2 microbial toxicity.
|
study
| 100.0 |
The ability to assess adherence to therapy in clinical trials is essential to accurately evaluate the efficacy of HIV infection prevention methods. Four recent clinical trials have demonstrated that pre-exposure prophylaxis (PrEP) regimens may prevent HIV infection in a significant proportion of individuals [1–5]; however, two additional HIV PrEP trials showed no efficacy [6, 7]. The trial failures were due in large part to poor adherence to the prescribed antiretroviral dosing regimens . The importance of adherence in topical PrEP is underscored in the results of the CAPRISA 004 trial of a 1% tenofovir vaginal gel. The decrease in HIV infection was 54% in women with over 80% adherence to prescribed, pericoital gel use compared to 28% in women with less than 50% adherence . Self-reporting adherence has been shown to be highly inaccurate: in the Carraguard microbicide trial, participants reported 94% gel use, but a dye indicator on the applicators showed only 61% of returned applicators had been used in 43% of sex acts . Assessment of intravaginal ring (IVR) adherence is more difficult because a single IVR is often used for one month or more, and can be removed for long periods. The ASPIRE clinical trial of an IVR delivering dapivirine showed increased efficacy against HIV-1 infection in subgroups exhibiting the highest adherence; however, accurate assessment of continuous IVR use over 1 month was difficult using the metrics of amount of dapivirine recovered from used devices and plasma dapivirine concentrations at clinic visits .
|
review
| 99.9 |
Electronic devices have been used previously for measuring adherence to medication, and include electronic pill monitors and inhaler dose monitors. The costs and benefits of these devices have been reviewed extensively [10–16]. Drawbacks of existing technologies include high cost, reliability, and lack of correlation with therapy adherence, i.e. opening the pill bottle as indicated by a pill monitor does not indicate ingestion of the pill. Recently, Malcolm, et al. reported a method for measuring adherence to intravaginal implant use by monitoring vaginal temperature using a commercially available DST nano-T implantable temperature logger (Star-Oddi, Gardabaer, Iceland) embedded in the device . The DST-nano-T devices encapsulated in silicone tubing of varying wall thickness to approximate an IVR accurately measured environmental temperature changes during 7 days of continuous monitoring in vitro. The devices also correctly recorded a series of insertion and removal events at 8 min intervals over 7 days of continuous use following vaginal insertion in three cynomolgus macaques. The cost of a single DST nano-T temperature logger (US$340), however, limits the potential of these devices to be widely adopted in large-scale clinical trials, particularly in resource-limited settings such as sub-Saharan Africa.
|
review
| 99.9 |
We report here an adherence monitoring IVR design that utilizes comparison of measured device temperature to a predetermined reference value to determine the insertion/removal status of the device. The custom electronic design is based on inexpensive, commercially available components, and a novel data reduction method allows for storage of up to 2048 status readings in only 256 bytes of non-volatile memory for retrieval after IVR removal.
|
other
| 99.8 |
The electronics modules were manufactured using industry standard printed circuit board (PCB) fabrication and surface-mount assembly methods, and consisted of a single ca. 5 mm × 12 mm PCB containing all electronic components including the thermistor temperature sensor and a separate battery pack containing two 1.55V SR416 silver oxide batteries (Fig 1). Electronic components were purchased from Digikey (Thief River Falls, MN, USA). The PCBs were fabricated by Sunstone Circuits (Mulino, OR, USA) and board assembly was completed by Screaming Circuits (Canby, OR, USA). Silicone IVRs with an open cavity for the electronics module were fabricated by injection molding from liquid silicone resin (MED-4840 LSR, Nusil, Carpenteria, CA, USA) using a custom single cavity mold and a laboratory-scale injection molding machine designed and constructed in-house . Assembled electronics modules were sealed in the IVR using a silicone adhesive (MED3-4213, Nusil, Carpenteria, CA, USA) so that the electronics module and battery are completely encased in silicone and with no contact with vaginal fluid.
|
other
| 75.5 |
(a) Adherence IVR prototype with electronics module embedded in IVR elastomer circumference as used in in vitro simulation experiments. For clarity, the IVR is shown prior to sealing the circuit board and cylindrical battery pack in place using silicone adhesive. (b) Close-up of prototype electronics module. (c) Cutaway 3D model of adherence IVR prototype used in sheep study. The electronics module and battery are enclosed in a central compartment rather than sealed in the IVR circumference to allow access to the electronics during initial in vivo evaluation. A portion of the central compartment wall is removed in the drawing to expose the electronics module and battery.
|
other
| 97.25 |
The performance of the adherence IVR was evaluated in vitro by exposing the devices to controlled temperatures simulating insertion and removal events. Devices were placed in a small aluminum enclosure with a flexible silicone heater (Watlow, St. Louis, MO, USA) and solid-state temperature controller (CT325, Minco, Minneapolis, MN, USA) providing accurate (±0.2°C) temperature control. The time, controller temperature set-point, and measured temperature were logged using a PC-based data acquisition system (National Instruments USB-6002 DAQ, Austin, TX, USA) using software written in the LabView development environment (National Instruments). For experiments spanning multiple days, the enclosure temperature was cycled between an “IN” state (~37°C) and “OUT” state (ambient, ~25°C) at predetermined intervals to simulate a sequence of IVR insertions and removals.
|
study
| 100.0 |
In order to determine the response time of the adherence monitor to temperature change, the thermistor voltage, Vth was measured as a function of ambient temperature as the device was cycled alternately between chambers held at 28°C and 37°C. Values of Vth were converted to temperature using a second-order polynomial fit to a five point temperature calibration curve over the range 25°C -44°C. The device response time was calculated as the time required to heat from 10% to 90% of the full-scale temperature difference (28.9°C to 36.1°C) or to cool from 90% to 10%.
|
study
| 99.94 |
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