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99db939c-b5e4-4b7a-b153-5ca3caf69018
| 2 |
This suggests that a single electroshock does not alter 5-HT functional activity. 3 Twenty-four hours after the final ECS of a series of 10 shocks given once daily, the rats were given tranylcypromine and L-tryptophan. They displayed greater hyperactivity than control rats not treated with ECS, suggesting that ECS increases 5-HT functional activity.
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99db939c-b5e4-4b7a-b153-5ca3caf69018
| 3 |
Brain concentrations of 5-HT, 5-HIAA and tryptophan were then unchanged by ECS. 5-HT synthesis and accumulation of 5-HT following tranylcypromine and L-tryptophan were not altered by ECS. 4 The hyperactivity following administration of the 5-HT agonist 5-methoxy N,N-dimethyltryptamine was enhanced by repeated (10 day) ECS, suggesting altered post-synaptic responses to 5-HT receptor stimulation.
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99db939c-b5e4-4b7a-b153-5ca3caf69018
| 4 |
5 Repeated ECS enhanced locomotor activity following tranylcypromine and L-DOPA. It did not alter brain noradrenaline or dopamine concentrations. 6 The latent period before a pentylenetetrazol-induced convulsion was shortened by repeated ECS. 7 Following repeated ECS there appears to be increased neuronal sensitivity to certain stimuli producing centrally mediated behavioural stimulation.
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99db939c-b5e4-4b7a-b153-5ca3caf69018
| 5 |
This is discussed in relation to the mechanism by which electroconvulsive therapy (ECT) produces its therapeutic effect.
|
84d3c2fa-1df3-4a85-97ad-ac9001bbc924
| 0 |
Effects of chronic nicotine administration on the denervated rat adrenal medulla. 1 The effects of chronic nicotine administration (1 or 10 mg/kg, s.c., twice daily) were studied in intact and denervated rat adrenal glands to determine the relative roles of central input and direct actions on catecholamines.
|
84d3c2fa-1df3-4a85-97ad-ac9001bbc924
| 1 |
2 Catecholamine depletion was obtained in the intact glands from 1-7 days of treatment with 10 mg/kg, with recovery by 14 days of treatment; catecholamines were not decreased in denervated adrenal glands. 3 Catecholamine depletion was accompanied by a decline in functional storage vesicles (determined by [3H]-adrenaline uptake per gland) in the intact side, while no change was seen in the denervated side;
|
84d3c2fa-1df3-4a85-97ad-ac9001bbc924
| 2 |
the proportion of newly synthesized vesicles increased markedly during 1-7 days of treatment with 10 mg/kg in the intact side, while a much smaller increase of shorter duration was seen in the denervated adrenal gland. 4 Chronic nicotine administration at either dose level induced tyrosine hydroxylase in both intact and denervated glands, but the increase occurred more slowly in the denervated glands.
|
84d3c2fa-1df3-4a85-97ad-ac9001bbc924
| 3 |
5 Dopamine beta-hydroxylase levels increased similarly in both sides during treatment with nicotine (10 mg/kg). 6 These studies suggest that although long-term adrenal denervation eliminates the catecholamine depletion caused by chronic administration of nicotine, the mechanisms for induction of catecholamine synthesizing enzymes are still capable of responding to the drug.
|
beae71bb-faf4-47cf-a05d-abe207a236d8
| 0 |
Catechol O-methyltransferase in red blood cells of schizophrenic, depressed, and normal human subjects. Catechol O-methyltransferase of lysed human red blood cells was assayed under optimal conditions, using saturating concentrations of the substrates, S-adenosyl-L-methionine and 3-4-dihydroxybenzoic acid. The mean enzyme activity found in 24 normal subjects was 29-2 nmol/hr/ml RBC.
|
beae71bb-faf4-47cf-a05d-abe207a236d8
| 1 |
The mean activity in blood of 33 female unipolar depressives was not significantly different from normal. However, higher enzyme activities were observed in the blood of 11 schizophrenic patients (38-9 nmol/hr/ml RBC). Partially purified enzyme preparations from blood of normal and schizophrenic individuals were indistinguishable with respect to substrate specificities, isoelectric pH values, and ratios of the two O-methylated products.
|
beae71bb-faf4-47cf-a05d-abe207a236d8
| 2 |
Therefore it is unlikely that any defect in O-methylation which may occur in schizophrenia can be attributed to a change in the intrinsic properties of erythrocyte catechol O-methyltransferase.
|
498b94ab-0d1c-48f9-8753-27ec96f1e140
| 0 |
The expectation of outcome from maintenance therapy in chronic schizophrenic patients. The results from a prospective follow-up study of a group of schizophrenic patients suggest that a significant proportion (41 per cent) are likely to relapse during a two-year period despite the prescription of long-acting injectable neuroleptic drugs.
|
498b94ab-0d1c-48f9-8753-27ec96f1e140
| 1 |
Some will relapse because of a failure of the regime, but others (32-37 per cent) because the pharmacological protection of these drugs would appear to be less effective in certain patients. Even with the major advantages of the long-acting injectable neuroleptics over oral medication, the schizophrenic patient population remains a group with a high incidence of psychiatric and social morbidity which continues to require the full resources of both the hospital and community services.
|
569d2f3e-845b-41f5-b664-418fc442c5af
| 0 |
Salicylates and renal function in rheumatoid arthritis. The effect of salicylate treatment on the kidney, particularly medullary function, was investigated. In a retrospective analysis patients with rheumatoid arthritis (RA) treated with high doses of salicylates were shown to have inferior urinary concentrating power and increased excretion of N-acetyl-beta-D-glucosaminidase (NAG) when compared with patients who had not received salicylate treatment.
|
569d2f3e-845b-41f5-b664-418fc442c5af
| 1 |
A prospective study of renal funcition in healthy people and patients with RA starting salicylate in therapeutic doses showed that while epithelial cell excretion was only transiently raised in both groups the excretion of NAG was increased in all cases at three days and this increase was sustained at 10 days, all values being much higher in the patients than in the healthy subjects.
|
569d2f3e-845b-41f5-b664-418fc442c5af
| 2 |
Thus salicylate treatment does cause renal tubular damage but this damage results in only minimal impairment of function and does not constitute a reason for withholding salicylate treatment.
|
c00c03f6-e546-475e-a200-a9ae0a7e9cad
| 0 |
Benzodiazepine drugs in general medical patients. Data from a hospital-based drug surveillance programme were used to determine how often benzodiazepine drugs were used in general medical wards. Benzodiazepines were the drugs most commonly used as hypnotics and were given to 32% of these patients. Concomitant use of more than one benzodiazepine drug or of benzodiazepines with other psychoactive drugs was common and often irrational.
|
c00c03f6-e546-475e-a200-a9ae0a7e9cad
| 1 |
A series of double-blind patient-preference studies comparing various benzodiazepines and a benzodiazepine with an antihistamine showed that for short-term hypnotic effect there were no differences between three common benzodiazepines but elderly patients preferred benzodiazepines to the antihistamine, which produced more undesired effects. These results suggest that currently diazepam is the hypnotic of choice for medical ward inpatients.
|
443cf0ae-1abf-4849-af0b-9eeb131d249b
| 0 |
Decrease of uptake and exchange of neurotransmitter amino acids after depletion of their synaptosomal pools. Synaptosomes prelabeled at 37 degrees C with radioactive amino acids (GABA, glutamate, glycine, taurine, alpha-aminoisobutyric acid, phenylalanine, leucine) and then washed at 0 degrees C on Millipore filters (DAWP 02500) lost 60-70% of the accumulated radioactivity.
|
443cf0ae-1abf-4849-af0b-9eeb131d249b
| 1 |
The loss was similar with exogenous tritiated GABA and glutamate, and with [14C]GABA and [14C]glutamate metabolically derived from [14C]glucose. In contrast, radioactive norepinephrine, dopamine and 5-hydroxytryptamine were almost totally retained by cold shocked synaptosomes. After pretreatment with reserpine and nialamide the loss of norepinephrine became significantly greater (about 25%).
|
443cf0ae-1abf-4849-af0b-9eeb131d249b
| 2 |
The uptake of radioactive GABA, glutamate and clycine after cold shock was about 50% reduced, whereas that of radioactive biogenic amines was less affected (reduction of 22% for norepinephrine, 29% for 5-hydroxytryptamine and 35% for dopamine). The loss of amino acids and the reduction of uptake could be minimized by performing the cold shock in hypertonic conditions.
|
443cf0ae-1abf-4849-af0b-9eeb131d249b
| 3 |
In synaptosomes prelabeled with [3H]GABA, a good correlation was observed among magnitude of amino acid pool depletion induced by cold shock or by 56 mM KCl, decrease of subsequent accumulation of [14C]GABA, and decrease of [14C]-GABA-stimulated [3H]GABA release (homoexchange).
|
ffab25bf-d9ad-4da5-96a0-d2fef4572d1a
| 0 |
Ultrastructural hypoxic changes in Ammon's horn and Purkinje cells. Guinea pigs were exposed for varying periods to different degrees of hypoxia by respiration of controlled mixtures of O2-N2 and the CNS subjected to both light and electron microscopic examination after aldehyde fixation by perfusion. The subacute anoxia experiments revealed an alteration in the rough endoplasmic reticulum of the Purkinje cells consisting of the formation of 'paired cisternae'.
|
ffab25bf-d9ad-4da5-96a0-d2fef4572d1a
| 1 |
In the chronic anoxia experiments, small ultrastructural alterations of the same cells were found in association with the appearance of monoparticulate glycogen. The authors debate the significance of these ultrastructural alterations in relation to the damage found in other organs.
|
96e4ff58-1c06-4eeb-82f1-67e716f9b074
| 0 |
The effect of taget organ removal on the development of sympathetic neurons. The role of target organs in the maturation of adrenergic neurons was studied in the neonatal rat. The superior cervical ganglion (SCG) and its end organs, the salivary glands and iris were employed as a model system.
|
96e4ff58-1c06-4eeb-82f1-67e716f9b074
| 1 |
Unilateral sialectomy and iridectomy in 3-day-old animals prevented the normal development of ganglion tyrosine hydroxylase (T-OH) and DOPA decarboxylase activities. These enzymes are highly localized to adrenergic neurons in the SCG, and were used to monitor maturation of these cells. Enzyme activity remained depressed for at least two months, the longest time tested.
|
96e4ff58-1c06-4eeb-82f1-67e716f9b074
| 2 |
In contrast, total ganglion protein, a measure of ganglion growth as a whole, initially developed normally. Six weeks after surgery, however, protein content was significantly lower in ganglia deprived of the normal field of innervation. Failure of normal enzyme maturation was apparently dependent on removal of ipsilateral end organs only, since bilateral sialectomy exerted no greater effect than unilateral sialectomy.
|
96e4ff58-1c06-4eeb-82f1-67e716f9b074
| 3 |
In adults, unilateral sialectomy and iridectomy did not significantly alter ganglion T-OH activity or protein in rats followed up to one month after surgery.
|
225d099a-07bf-4d65-8480-4877b7ef1edf
| 0 |
Sensitization and habituation of the plantar cushion reflex in cats. The plantar cushion reflex in cats was examined as a model system in a mammal for the study of the effects of repeated stimulation on neural transmission. Effects of various frequencies and intensities of stimulation were similar to those seen in other reflex systems.
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225d099a-07bf-4d65-8480-4877b7ef1edf
| 1 |
For instance, for a fixed number of stimuli, habituation of the plantar cushion reflex was more marked at 10 Hz than at 2.0 Hz, and with 1.0 X threshold stimulation than with 5.0 X threshold stimulation. Sensitization occurred at intermediate intensities and frequencies of stimulation. Dorsal root potentials were studied;
|
225d099a-07bf-4d65-8480-4877b7ef1edf
| 2 |
changes in dorsal root potentials during iterated stimulation did not correlate with the changes in the plantar cushion reflex. These changes in the plantar cushion reflex were also unrelated to variations in afferent transmission peripheral to the spinal cord. Sensitization and habituation in the plantar cushion reflex occurred during iterated stimulation, were produced centrally, and were unrelated to mechanisms of presynaptic inhibition.
|
bcb382aa-a09b-4249-baa9-fcae6e8d6133
| 0 |
Quantitative localization of tyrosine hydroxylase, dopamine-beta-hydroxylase, phenolethanolamine-N-methyl transferase, and glutamic acid decarboxylase in spinal cord. Sensitive radiometric assays for tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), phenylethanolamine-N-methyl transferase (PNMT), and glutamic acid decarboxylase (GAD) have been combined with microdissection techniques for quantitative localization of these synthetic enzymes in rabbit spinal cord.
|
bcb382aa-a09b-4249-baa9-fcae6e8d6133
| 1 |
TH was present uniformly in gray and white matter. DBH was higher in the lateral horns than in the other gray matter areas, and was not detectable in white matter. PNMT was detectable in gray but not white matter, and was considerably lower in activity than the other catecholamine synthetic enzymes.
|
bcb382aa-a09b-4249-baa9-fcae6e8d6133
| 2 |
GAD was higher in the dorsal horns at the cervical and lumbar levels than in other gray matter areas and relatively low in white matter. GAD activity was considerably higher than the catecholamine synthetic enzyme activities. The quantitative localizations are consistent with the qualitative immunohistochemical enzymes maps and distributions of the related putative neurotransmitters.
|
270143b3-3e1f-47f0-aa2d-39340bcc46ce
| 0 |
Extraction of a calcium-phospholipid-phosphate complex from bone. A calcium-phospholipid-phosphate complex with a constant 1:1 calcium to total phosphate molar ratio is shown to exist in rabbit and calf bone. This complex, which may be involved in the transport and deposition of bone mineral, appears to constitute a significantly greater proportion of the lipids of younger bone than of more mature bone.
|
270143b3-3e1f-47f0-aa2d-39340bcc46ce
| 1 |
The comples was isolated by a modified Folch extraction employing ultrasonic disruption of cellular material. Evidence is presented to show that the complex is a natural constituent of bone rather than one created artifactually during extraction.
|
39adf61e-b632-4e23-a473-337788a40967
| 0 |
Magill circuit and controlled ventilation. Nine patients under anaesthesia were controlled manually with the Magill attachment. Nine other patients using the same circuit under anaesthesia breathed spontaneously. Blood gases were studied throughout the period of operation to determine the adequacy of ventilation. The results show that the Magill attachment was adequate for controlled ventilation using normal flows (9 1/min) in young healthy patients.
|
6bad2ff3-d3fd-4b4b-bc1d-42afbfcf7b4d
| 0 |
The reduction of coma time in lipophilic drug overdose using castor oil. A clinical trial of castor oil in overdoses of lipophilic drugs gave a strong clinical impression that it was effective in speeding up recovery. Therefore, animal experiments were undertaken to confirm that castor oil acts as a ligand in Ethchlorvynol poisoning and that its use reduces coma time.
|
6bad2ff3-d3fd-4b4b-bc1d-42afbfcf7b4d
| 1 |
Serial serum levels of Ethchlorvynol were obtained from dogs given Ethchlorvynol 150 mg/kg alone, and the same dose dissolved in castor oil 15 ml/kg in a crossover fashion. The result was a reduction of peak serum levels and of the half-life of the drug when the castor oil solution was used.
|
6bad2ff3-d3fd-4b4b-bc1d-42afbfcf7b4d
| 2 |
In order to mimic the clinical situation more closely, a further crossover study was undertaken using Ethchlorvynol 300 mg/kg alone and the same dose followed by castor oil 15 ml/kg repeated q12h. This showed no delay in reaching peak serum concentration and no reduction of peak levels.
|
6bad2ff3-d3fd-4b4b-bc1d-42afbfcf7b4d
| 3 |
However, it did show a 31 per cent reduction in the half-life of the drug. This change is statistically significant, and supports the continued use of castor oil in lipophilic drug overdose.
|
43438e0e-0a92-4155-af59-e1835dc6573c
| 0 |
An endogalactosaminidase from Streptomyces griseus. An endogalactosaminidase has been purified 34-fold from the culture filtrate of Streptomyces griseus. This enzyme cleaves GalN-GalN linkages in oligogalactosaminoglycan, a galactosamine-rich oligosaccharide isolated from the culture filtrate of a Neurospora mutant. Since some or all of the GalN-GalN bonds in this molecule link positions 1 and 4, and are in the alpha-configuration, we are probably dealing with an endo-alpha-(1 leads to 4)-galactosaminidase, bu this characterization is only tentative because the few bonds cleaved by the enzyme could have a different structure.
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43438e0e-0a92-4155-af59-e1835dc6573c
| 1 |
The enzyme is inactive towards N-acetyl-oligogalactosaminoglycan and chitosan. The endogalactosaminidase preparations also cleave high molecular weight galactosaminoglycan (obtained from Neurospora) into fragments greater than or equal to 10(4) daltons in molecular weight, and catalyze the release of Neurospora sporelings from the glass surfaces to which they are anchored.
|
43438e0e-0a92-4155-af59-e1835dc6573c
| 2 |
Galactosaminoglycan-cleaving and sporeling-releasing activities elute jointly from DEAE-cellulose columns. This observation provides further support for an earlier proposal that the sporelings are anchored to the glass by means of galactosaminoglycan molecules.
|
269578f5-33c8-4b7e-a0ee-b8ca3d99553b
| 0 |
Fractionation of nucleolar proteins by two-dimensional gel electrphoresis. Isolation of nucleolar proteins was obtained by dissociation in the presence of urea-guanidine hydrochloride, followed by high-speed centrifugation to remove nucleic acids. At least 31 fractions of nucleolar proteins were detected by isoelectrofocusing gel electrophoresis in pH range 3.5
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269578f5-33c8-4b7e-a0ee-b8ca3d99553b
| 1 |
-10. Following two-dimensional gel electrophoresis on sodium dodecyl sulfate-polyacrylamide slab gels, more than 100 components of nucleolar proteins were identifieid. Two-thirds of nucleolar proteins were located in the pH range 5-8 following isoelectrofocusing. The molecular weights of these classes of proteins were shown to be mostly 30000-70000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
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663d1480-6338-48c2-828f-b2d457d32931
| 0 |
Temperature-induced alanine oxidation in a psychrotrophic Pseudomonas. A psychrotrophic pseudomonad isolated from iced fish oxidized alanine at temperatures close to 0 degrees C and grew over the range 0 degrees C-35 degrees C. The rate of oxidation of alanine, measured manometrically, by cells grown at 2 degrees C was lower than that of cells grown at 22 degrees C.
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663d1480-6338-48c2-828f-b2d457d32931
| 1 |
However, the consumption of oxygen after heat treatment at 35 degrees for 35 min was reduced considerably by 2 degrees C grown cells. Alanine oxidase activity was tested in an extract from cells grown at 2 degrees C and 22 degrees C with alanine as the sole carbon, nitrogen, and energy source.
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663d1480-6338-48c2-828f-b2d457d32931
| 2 |
Cells grown at 2 degrees C produced an alanine oxidase with a temperature optimum of 35 degrees C and pH optimum of 8, which lost about 80% activity by heat treatment at 40 degrees C for 30 min. There was no change in activity after dialysis at pH 7, 8, or 9.
|
663d1480-6338-48c2-828f-b2d457d32931
| 3 |
Extracts from cells grown at 22 degrees C contained an alanine oxidase system with an optimum temperature of 45 degrees C, a pH optimum above 8, and only about 30% reduction of activity after heat treatment. This enzyme activity was concentrated in the 0.5 M elution fraction from a Sephadex column, and dialysis reduced the activity at pH 7 and 8.
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663d1480-6338-48c2-828f-b2d457d32931
| 4 |
Mesophilic enzyme synthesis apparently started around a growth temperature of 10 degrees C. The crude alanine oxidase systems of Pseudomonas aeruginosa derived from cells grown at 13 degrees C and 37 degrees C had a common optimum temperature of 45 degrees C. These data suggest that one mechanism of psychrophilic growth by psychrotrophic bacteria may be the induction of enzymes with low optimum temperatures in response to low temperature conditions.
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38b64378-ec9b-47ec-9657-750acccfbd94
| 0 |
Growth characteristics of a cell line derived from the pig oviduct. Further evidence for the establishment of the pig fallopian tube (PFT) cell line as a continuous cell line was shown by an increase in the maximum population density as the number of subcultures increased. The optimal pH and temperature-growth ranges appeared to be 7.4
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38b64378-ec9b-47ec-9657-750acccfbd94
| 1 |
-7.8 and 37-41 degrees C respectively, and the population doubling time was 20-25 h under optimal growth conditions. With progressive subculture, the serum requirements dropped from 20 to 2%. A plating efficiency of 2 to 4% was found in all serial subcultures. Colonies were observed in agar suspension culture at the 146th subculture and thereafter.
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38b64378-ec9b-47ec-9657-750acccfbd94
| 2 |
Chromosomal alterations were found in the 100th subculture and thereafter.
|
5e5cbd03-7ba3-4c64-a387-ec30de61b2bf
| 0 |
Characteristics of a facultatively psychrophilic Acinetobacter species isolated from river sediment. A facultatively psychrophilic bacterium isolated from river sediment was identified as an Acinetobacter species, similar to those previously characterized as A. lwoffi. The strain was extremely lipolytic and hemolytic. Some action on crude oil was also observed.
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5e5cbd03-7ba3-4c64-a387-ec30de61b2bf
| 1 |
The organism was able to utilize a wide variety of carbon and energy sources when tested at both 20 and 30 degrees C. A comparison is made with the previously proposed type strain of A. lwoffi. The bacteria had a Gram-negative cell wall containing an electron-dense intermediate layer.
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5e5cbd03-7ba3-4c64-a387-ec30de61b2bf
| 2 |
Cell division occurred with the formation of a septum and slight constriction.
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5419ae99-0178-4195-bcad-5987a3c61a6b
| 0 |
Zoospore chemotaxis in Australian isolates of Phytophthora species. Zoospores of Australian isolates of Phytophthora drechsleri, P. cryptogea, P. cinnamomi, P. nicotianae var. parasitica, and P. citricola were examined for their chemotactic responses to asparagine, glutamine, aspartate, glutamate, and structurally related compounds. Structural requirements for attraction include the alpha-amino-acid group with a short carbon chain terminating in an amide group.
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5419ae99-0178-4195-bcad-5987a3c61a6b
| 1 |
The one American isolate tested gave a different result and possible reasons for this are discussed. The pH of the environment was important, a neutral-charged molecule was more attractive than a negatively charged molecule, hence glutamine and aspartate were more attractive at pH 3.0 than pH 5.0.
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5419ae99-0178-4195-bcad-5987a3c61a6b
| 2 |
Zoospores tended to move away from regions with a high hydrogen ion concentration. Compounds other than amino acids were slightly attractive including several sugars and ethanol. Synergistic interactions between amino acids, ethanol, and sucrose were observed and may account for the high levels of attraction of zoospores to root exudates and extracts.
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ed69ebb5-7bd6-4352-abc6-23c3a1faf66a
| 0 |
Double-blind evaluation of oral L-prolyl-Lleucyl-glycine amide in Parkinson's disease. A 4-month double-blind study comparing the effect of increasing oral doses (up to 1.0 g daily) of synthetic L-proyl-L-leucyl-glycine amide (PLG) and placebo in 20 parkinsonian patients showed no significant improvement in objective scores of functional disability.
|
ed69ebb5-7bd6-4352-abc6-23c3a1faf66a
| 1 |
However, important trends and some significant results were observed with the lower doses of PLG. These essentially negative results may be attributed to poor intestinal absorption of the compound, a short biologic half-life in the blood, or administration of oral doses that were much higher than required, or a combination of factors.
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ed69ebb5-7bd6-4352-abc6-23c3a1faf66a
| 2 |
In further studies with this peptide, which are encouraged, the intravenous route should be used until the question of intestinal absorption is resolved.
|
6014c2e0-24ef-437f-abd8-46ec8f3c666f
| 0 |
Carcinoid tumors of the thymus. Three patients with carcinoid tumors of the anterior mediastinum are described. Study of these patients and an analysis of previously reported cases indicates that the thymus is the primary site of these tumors, which are probably related to the presence of Kulchitsky cells in normal thymus.
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6014c2e0-24ef-437f-abd8-46ec8f3c666f
| 1 |
These neoplasms differ clinically and anatomically from conventional thymomas. They occur predominantly in men, are not associated with myasthenia gravis or red-cell hypoplasia, and are more aggressive tumors than thymomas. Histologically, they are similar to carcinoid tumors of other organs and differ from the variable combination of epithelial cells and lymphocytes of thymomas.
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6014c2e0-24ef-437f-abd8-46ec8f3c666f
| 2 |
Although they are usually locally invasive and frequently metastasize, the clinical course is usually protracted. It is probable that the reported examples of Cushing's syndrome related to thymomas were actually associated with thymic carcinoid tumors.
|
02b5377d-7859-4dd9-bfaa-6fe1f4cb9332
| 0 |
Effects of hypoxia on distribution of cardiac output and organ blood flow in the rabbit. Regional vascular response to hypoxia. The hemodynamic responses of various vascular beds in the systemic circulation to prolonged moderate hypoxia were studied in the rabbit using the radioactive microsphere method. Although cardiac output remained unchanged, there was a redistribution of blood flow in which blood was mainly diverted from the kidneys to provide greater supply to heart, brain and skeletal muscle. These regional adjustments are similar to those seen after low cardiac output due to hemorrhage or endotoxic shock.
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b5b4d4c7-e4eb-4f72-b592-f31522404c5a
| 0 |
Quenching of tryptophanyl fluorescence of human growth hormone by iodide. Quenching of tryptophanyl fluorescence of human growth hormone by I- followed saturation kinetics and was abolished by KSCN. In the presence of 6 M guanidine hydrochloride quenching was linear between 0 to 0.2 M KI. These results suggest that I- quenched the fluorescence of the native hormone by binding at or near the single tryptophanyl residue.
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b5b4d4c7-e4eb-4f72-b592-f31522404c5a
| 1 |
Quenching by 0.1 M KI decreased exponentially with increasing concentrations of human and bovine growth hormones. Acidification did not have a significant effect on quenching of the human hormone, but it markedly decreased quenching of the bovine hormone. Conformational differences at the vicinity of the lone tryptophanyl residue that could be inferred by these and other experiments may be contributing to the biological specificity of native human and bovine growth hormones.
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c07011d5-984e-4a8a-b870-817cea6d46e7
| 0 |
Comparison of the metabolism of benzo[alpha]pyrene and binding to DNA caused by rat liver nuclei and microsomes. Administration of 3-methylcholanthrene (3MC) to rats greatly enhanced the aryl hydrocarbon hydroxylase (AHH) activity of liver nuclei. However, the binding in vitro [3H]benzo[alpha]pyrene (BP) to DNA within the nuclei which occurred at the same time as hydroxylation of BP was much less enhanced.
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c07011d5-984e-4a8a-b870-817cea6d46e7
| 1 |
Thin layer chromatography of the metabolites of BP produced by these nuclei revealed the same metabolites in similar relative amounts as were produced by rat liver microsomes prepared from rats which had received 3MC. The binding to DNA was further analysed by hydrolysis of the DNA and fractionation on a Sephadex column.
|
c07011d5-984e-4a8a-b870-817cea6d46e7
| 2 |
This analysis revealed that the binding to DAN in nuclei was very similar in nature to that which occurred when calf-thymus DNA was added to microsomes metabolising BP.
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98ead35b-25d1-4be9-bc67-b7ecd091b152
| 0 |
Inhibition of nadph-driven microsomal lipid peroxidation by cytosol factor(s). Effect of a fat-free, high carbohydrate diet. Male Swiss mice were given free access to a fat-free, high carbohydrate diet. The liver cytosol fraction from these mice contained a heat-sensitive factor that markedly inhibited microsomal, ferric pyrophosphate stimulated, NADPH-driven lipid peroxidation.
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98ead35b-25d1-4be9-bc67-b7ecd091b152
| 1 |
The diet-induced factor was apparently incorporated into the microsomes after 12 days of continuous feeding, since lipid peroxidation by these microsomes was strongly diminished. The factor disappeared from the cytosol after 24 h of fasting and reappeared after refeeding the mice with the fat-free, high carbohydrate diet.
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302d2aed-ccf1-4b09-bf3d-1aa36879abef
| 0 |
The repression and derepression of hepatic tyrosine aminotransferase by carcinogens. Like hydrocortisone, a single carcinogenic dose of dimethylnitrosamine (50 mg/kg) initiates the induction cycle for hepatic tyrosine aminotransferase in adrenalectomized rats. However, following this initial induction in the presence of dimethylnitrosamine, the enzyme becomes refractory to reinduction by known inducers.
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302d2aed-ccf1-4b09-bf3d-1aa36879abef
| 1 |
The administration of thioacetamide to either adrenalectomized or intact rats leads to an immediate and progressive loss of inducibility by hydrocortisone, dibutyrylcyclic AMP or dimethylnitrosamine. Although the thioacetamide-induced repression was not reversed even up to 10 weekds after the cessation of treatment, it was reversed after the induction of liver regeneration.
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302d2aed-ccf1-4b09-bf3d-1aa36879abef
| 2 |
Both the carcinogen-mediated induction and repression of tyrosine aminotransferase appears to occur by mechanisms which do not involve the corticosteroid-binding proteins which normally mediate the induction by glucocorticoids.
|
5c05abfa-c0cd-463e-8629-da208feff058
| 0 |
[Effect of intratumoral injection of bacterial and viral neuraminidase in rats]. We studied the effect of neuraminidase injection in rat's tumor at different doses: 5,10,50,100, 500 U and we concluded that: There was no difference between the rats treated with 5,10,50 U and the controls. The y died 3 weeks after the injection. But the rats treated by 100 at 500 U of NA died quickley, in the week, of long metastases.
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cde36722-58af-45d9-b0bb-514abac89892
| 0 |
[Changes in transmitter release at frog neuromuscular junction induced by 4-aminopyridine]. 4-aminopyridine (4-AP) at micromolar concentrations, increases the end-plate potential amplitude in curarized preparations and the mean quantal content in every preparation tested, but the spontaneous release is not modified by 4-AP. These results can explain the anticurare activity observed in the wole animal or in vitro. 4-AP prolongs the falling phase of the muscle action potential without change in the muscle membrane potential.
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313554c1-5c68-4c5f-aa01-18abda93e3f0
| 0 |
Contribution of tissue acidosis to ischemic injury in the perfused rat heart. The isolated perfused working rat heart preparation has been used to study the effects of respiratory acidosis on myocardial metabolism and contractilly. Hearts were perfused with 5 mM glucose and 10(-2) U/ml of insulin in order to enhance metabolsim of glucose relative to that of fatty acids.
|
313554c1-5c68-4c5f-aa01-18abda93e3f0
| 1 |
After perfusion with Krebs bicarbonate medium at pH 6.6, hearts rapidly ceased performing external work and peak left ventricular pressure fell by 75% after 5 minutes. Oxygen consumption, rate of ATP generation and overall glycolytic flux also declined rapidly. After about 2 minutes of perfusion, the fall of glycolytic flux showed a partial reversal, which was largely accounted for by increased lactate production, so that glucose oxidation decreased further.
|
313554c1-5c68-4c5f-aa01-18abda93e3f0
| 2 |
The reversal of glycoltic flux could be accounted for by partial release of H+ inhibition of phospho-fructokinase by increased tissue levels of adenosine 5'-diphosphate (ADP), adenosine monophosphate (AMP) and P1 and decreased levels of adenosine triphosphate (ATP) and creatine phosphate. The increased proportion of glucose uptake converted to lactate together with an increase of the tissue lactate/pyruvate ratio could be accounted for by inhibition of the malate-aspartate cycle combined with tissue hypoxia.
|
313554c1-5c68-4c5f-aa01-18abda93e3f0
| 3 |
Lactate accumulated in the tissue as a result of a decreased permeability of the plasma membrane to lactate. Decreased oxygen delivery to the myocardium was caused by secondary constriction of the coronary vessels. In further experiments, the coronary flow was regulated by an external pump which delivered fluid at a controlled rate into the aortic cannula above the coronary arteries, and the degree of tissue hypoxia was monitored by measuring changes of pyridine nucleotide reduction state by surface fluorescence techniques.
|
313554c1-5c68-4c5f-aa01-18abda93e3f0
| 4 |
The effects of acidosis uncomplicated by possible hypoxia were compared directly with those produced by ischemic hypoxia. The effects of acidosis under these conditions were similar to those described above, and to those produced by ischemia. From these and other data it is concluded that the effects of ischemia are caused by a lowering of the intracellular pH, which decreases the rate of energy production relative to the rate of energy demand.
|
313554c1-5c68-4c5f-aa01-18abda93e3f0
| 5 |
However, it is suggested that the primary cause of the decreased peak systolic pressure with either acidosis or ischemia is not a result of a defect of energy metabolism, but is due to alteration of the calcium cycle of the heart. Possible causes of irreversible heart failure after prolonged ischemia are discussed.
|
aab78435-4b34-4050-b229-afd11b447fbd
| 0 |
Polarographic method for rapid microdetermination of cholesterol with cholesterol esterase and cholesterol oxidase. Cholesterol concentrations in serum are enzymatically determined rapidly by use of a polarographic oxygen analyzer with a circuit modified to record simultaneously the amount and rate of oxygen consumption. The final assay system, assessed from the oxygen consumption value that we found to be optimum, consists of 1 ml of sodium phosphate buffer (0.6
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aab78435-4b34-4050-b229-afd11b447fbd
| 1 |
mol/liter, pH 7.0) containing NaN3 (10 mg/liter), Triton X-100 surfactant (10 ml/liter), 0.4 U of cholesterol ester hydrolase, and 0.6 U of cholesterol oxidase. Oxygen consumption and cholesterol concentration are linearly related to 8.0 g/liter, and only 10 mul of serum is required.
|
aab78435-4b34-4050-b229-afd11b447fbd
| 2 |
Replicate analyses of pooled serum by the present method demonstrated the following inter-run precision: mean = 1731 mg/liter, SD = 22.3 mg/liter, CV = 1.3%. Bilirubin and ascorbic acid were without effect on the present method, unlike the enzymatic colorimetric methods.
|
ea600a01-e192-42d0-94c6-5f28c5596af7
| 0 |
Measurement of 25-hydroxyvitamin D3 in serum. We describe a method for measuring 25-hydroxyvitamin D3 in serum. Extraction with dichloromethane/methanol (2/1 by vol), followed by chromatography on a column of Sephadex LH-20, resulted in an overall analytical recovery of 82% +/- 3.5
|
ea600a01-e192-42d0-94c6-5f28c5596af7
| 1 |
% (SD). Diluted normal rat serum was used as binding protein because it contains a transport protein that has both a high affinity (Ka = 2 X 10(10) liter/mol) and a high capacity (3 X 10(-6) mol/liter) for 25-hydroxyvitamin D3. There is no advantage in using more complex binding proteins derived either from rachitic animals or from cytosol preparations.
|
ea600a01-e192-42d0-94c6-5f28c5596af7
| 2 |
Concentrations of 25-hydroxyvitamin D3 (13.4 +/- 4 mug/liter) in the serum of apparently normal Belgian subjects are lower than those reported for North Americans, but resemble those reported for the United Kingdom.
|
b27e09a2-774c-4c26-9cc3-c1e25c30d078
| 0 |
Gamma-glutamyltransferase: Substrate inhibition, kinetic mechanism, and assay conditions. Gamma-glutamyltransferase activity in serum is shown to be competitively inhibited by the two substrates gamma-glutamyl-4-nitroanilide and glycylglycine. Awareness of this is of importance when one is choosing final reaction conditions for the assay of the enzyme.
|
b27e09a2-774c-4c26-9cc3-c1e25c30d078
| 1 |
Gamma-glutamyltransferase probably acts by a "ping-pong bi-bi" kinetic mechanism, which fits with the double competitive substrate inhibition demonstrated. The product, 4-nitro-aniline, appears to be an uncompetitive dead-end inhibitor of both substrates. Various amino acids, particularly glycine and L-alanine, inhibit the enzyme.
|
b27e09a2-774c-4c26-9cc3-c1e25c30d078
| 2 |
Their inhibition patterns are uncompetitive with glycylglycine and competitive with gamma-glutamyl-4-nitroanilide. On the basis of the present and other studies, the Scandinavian Society for Clinical Chemistry and Clinical Physiology is going to recommend for routine use a gamma-glutamyltransferase method in which the final concentrations of gamma-glutamyl-4-nitroanilide and glycylglycine are 4 and 75 mmol/liter, respectively.
|
5f2413dc-414b-443f-abce-7dcce5df50f3
| 0 |
New techniques for ion-selective measurements of ionized calcium in serum after pH adjustment of aerobically handled sera. I report further experience in measuring ionized calcium (Ca2+) with the AMT Electron System and its serum standards and solid-state, dip, calcium-selective electrodes. With this system, serum pH can be adjusted with CO2 gas and Ca2+ and pH simultaneously measured;
|
5f2413dc-414b-443f-abce-7dcce5df50f3
| 1 |
when 5.2% CO2 (40 mm pco2) is used for sample equilibration, the standard bicarbonate concentration is also provided. I measured serum Ca2+ as a function of pH between pH 7.0 and 9.0 and found the relationship to be reproducible, with no evidence of irreversible complexing of Ca2+.
|
5f2413dc-414b-443f-abce-7dcce5df50f3
| 2 |
When the pH of aerobically exposed, mailed sera was restored to the original values, their values for Ca2+ were the same as for the fresh sera. Measurement of Ca2+ in routinely (aerobically) handled sera after pH restoration with CO2 gas was therefore validated, both samples from within an institution and mailed specimens.
|
5f2413dc-414b-443f-abce-7dcce5df50f3
| 3 |
Standardization to pH 7.40 is recommended for routine measurements, is generally more accurate than use of heparin or quasianaerobic techniques, and is a practical approach. In patients with possible uncompensated acid-base disturbance (which may be indicated by an abnormal standard bicarbonate concentration if not suspected clinically), patient pH should be measured independently as part of the usual strict, anaerobic blood-gas-analysis procedures.
|
5f2413dc-414b-443f-abce-7dcce5df50f3
| 4 |
Abnormal patient pH must be considered in the interpretation of Ca2+ results determined at pH 7.40 which are borderline or slightly abnormal; most accurately, Ca2+ may be measured in the separated sera at the previously determined patient pH value. Studies of aqueous solutions with the currently used Ca2+ electrodes showed a selectivity coefficient (the constant which relates the activity of an interfering ion to the activity of calcium that would contribute the same emf) KNa=0.0031
|
5f2413dc-414b-443f-abce-7dcce5df50f3
| 5 |
+/- 0.0003 (SE) and KMg=0.046 +/- 0.004 (SE). At physiological concentrations of Ca2+, physiologically encountered variation in Na+ is of no significance in resulting Ca2+, but extreme variation in Mg2+ may cause an error of approximately 1%.
|
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