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a84ee103-affd-4fe2-9cc6-d5e5b6e416b8
| 3 |
These results demonstrate that whatever the mechanism, increased levels of acid hydrolases as well as certain neutral and alkaline hydrolases are present in osteoarthritic and rheumatoid synovia, and these enzymes are probably contained in the synovial lining cells.
|
85956b77-736e-4936-9e51-57f635e102ee
| 0 |
Effects of acute metabolic acidosis on parathyroid hormone action and calcium mobilization. Mechanisms through which metabolic acidosis increases calcium mobilization have been investigated in thyroparathyroidectomized rats with induction of acute metabolic acidosis by infusing NH4C1 intravenously. Acute metabolic acidosis directly raised serum calcium concentration and augmented the effect of parathyroid hormone (PTH) to raise serum calcium concentration.
|
85956b77-736e-4936-9e51-57f635e102ee
| 1 |
The same effects of metabolic acidosis were observed in rats with surgically removed intestines and bilateral nephrectomy, suggesting that acute metabolic acidosis directly increases calcium mobilization from bone and augments the effect of PTH to mobilize calcium from bone. In the kidney, acidosis directly inhibited the tubular reabsorption of calcium, but augmented the effect of PTH to increase tubular reabsorption of calcium.
|
85956b77-736e-4936-9e51-57f635e102ee
| 2 |
Acidosis had no measurable effect on calcitonin action.
|
92158ff5-e9cc-4467-be85-2e545ee7cd61
| 0 |
Metabolism of histamine in secreting and isolated canine stomach. Total 14C activity in juice secreted by gastric pouches of six dogs and seven isolated canine stomachs was determined in response to intravenous and intra-arterial infusions of histamine and [14C]histamine. The proportions of 14C attributable to histamine, Nalpha-methylhistamine (NalphaMeH), Nalpha,Nalpha-dimethylhistamine (NalphaNalphaMe2H), N-telle-methylhistamine (NtauMeH), imidazole acetic acid (ImAA), N-methylimidazole acetic acid (NtauMeImAA), acetylhistamine (AcH), and histaminol (HOH) were defined using thin-layer chromatography.
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92158ff5-e9cc-4467-be85-2e545ee7cd61
| 1 |
Similar estimates were made at the end of infusions on blood, gastric mucosa, and gastric muscle. Methylation was the major, or sole, route of metabolism of histamine in the gastric mucosa, and the major product was inactive NtauMeH. Small quantities of the active NalphaMe derivatives, particularly NalphaNalphaMe2H, were identified in both the juice and mucosa.
|
92158ff5-e9cc-4467-be85-2e545ee7cd61
| 2 |
Little or no ImAA, NtauMeImAA, AcH, and HOH were present in juice from isolated stomachs while they did occur in the juice from intact dogs, demonstrating they are extragastric metabolites of histamine. A major mucosal function of methylation of histamine is inactivation, although NalphaMe derivatives formed may play a role in the secretagogue action of histamine.
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d68e5bb6-a46b-4942-a2ce-1ef8048aefa9
| 0 |
Intracellular bicarbonate of skeletal muscle under different metabolic states. Intracellular bicarbonate of single muscle fibers in vivo was measured by a direct electrometric method simultaneously with the membrane PD in rats under seven different metabolic states. From the measured intracellular bicarbonate values and the PCO2, the bicarbonate equilibrium potential and the intracellular pH were calculated.
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d68e5bb6-a46b-4942-a2ce-1ef8048aefa9
| 1 |
The mean intracellular [HCO3-] under normal control conditions was 10.3 +/- 0.7 mM (SE). The intracellular bicarbonate fell significantly in both chronic metabolic acidosis and chronic K+ depletion. In contrast, intracellular bicarbonate was elevated in chronic metabolic alkalosis, K+ loading, and Na+ depletion.
|
d68e5bb6-a46b-4942-a2ce-1ef8048aefa9
| 2 |
Taking intracellular pH as an index of the acid-base status of cells, we find that whereas the calculated cell pH decreased along with the cell bicarbonate in both chronic metabolic acidosis and K+ depletion, cell pH increased along with the bicarbonate only in chronic metabolic alkalosis. Cell pH was unchanged in both chronic K+ loading and Na+ depletion.
|
158bb2d4-48da-44f8-a941-ca439466cf1f
| 0 |
Effect of acid lumen pH on potassium transport in renal cortical collecting tubules. In order to determine the effect of acid lumen pH on renal tubular potassium transport, cortical collecting tubules were dissected from rabbit kidneys and perfused in vitro. When the pH of the perfusate was lowered from 7.4
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158bb2d4-48da-44f8-a941-ca439466cf1f
| 1 |
to 6.8, potassium secretion into the tubule lumen decreased by an average of 47%. The transepithelial voltage increased from a mean value of -32 mV (lumen negative) at pH 7.4 to -51 mV at PH 6.8. Net sodium absorption from the tubule lumen was essentially unchanged (5% mean decrease).
|
158bb2d4-48da-44f8-a941-ca439466cf1f
| 2 |
Transepithelial voltage and potassium secretion returned to control values when the pH of the perfusate was raised to 7.4. Alterations in pH of the bath had no comparable effect on the transepithelial voltage, whether the bath pH was increased or decreased. We conclude that a decrease in the pH of the tubule fluid of itself inhibits active potassium secretion in this tubule segment, providing an additional explanation for the decrease in potassium excretion found in acidosis.
|
158bb2d4-48da-44f8-a941-ca439466cf1f
| 3 |
The negative voltage (presumably caused by sodium absorption out of the lumen) is increased under these conditions, possibly because of reduction of a smaller counterbalancing positive voltage caused by potassium secretion into the lumen.
|
ad79312b-8186-4692-9269-4405b6dff620
| 0 |
Reflex sympathetic tachycardia during intravenous infusions in chronic spinal cats. The reflex tachycardia elicited by rapid intravenous infusions of a blood substitute was studied in 21 chronic cats with spinal sections at C8. All animals could breath spontaneously. The day after section the average resting heart rate (HR) and arterial pressure (AP) were 109 beats/min and 98/67 mmHg, respectively.
|
ad79312b-8186-4692-9269-4405b6dff620
| 1 |
Vagal blockade with atropine (0.5-0.7 mg/kg iv) was performed prior to each infusion, increasing the average HR To 127 beats/min. In 39 infusions in 21 cats the average increase in HR was 10 beats/min (range from -6 to +22 beats/min). A tachycardia was observed in all but five trials, four of which were obtained in two cats that subsequently responded with a tachycardia.
|
ad79312b-8186-4692-9269-4405b6dff620
| 2 |
In seven animals the neural circuit mediating the response was partially or totally interrupted by section of several thoracic dorsal roots (T1-T4 or T1-T6) and of the spinal cord at the inferior level of these sections (between T6 and T7). The tachycardia response was progressively reduced and finally abolished by these procedures.
|
ad79312b-8186-4692-9269-4405b6dff620
| 3 |
These experiments indicate that spinal neural mechanisms are likely to contribute to the phenomenon first described by Bainbridge.
|
be224e2e-60cb-47db-98bb-cab9bae2bf97
| 0 |
Sudden potential drop in bullfrog gastric mucosa. The previously reported sudden potential drop (SPD), which occurs under anoxia in 10% CO2, has been further explored. We find several conditions necessary for this effect: 1) anoxia; 2) serosal pH less than 7.1;3) presence of chloride;
|
be224e2e-60cb-47db-98bb-cab9bae2bf97
| 1 |
and 4) a PD, either spontaneous or voltage clamped, which changes across the region of 10 mV, serosal positive. With the first three conditions satisfied, a reversible decrease in measured resistance can be produced at will by changing the clamp voltage. In the anoxic, low-resistance state, changes in K+ or C1- concentration give little change in voltage, showing that the increased conductivity is not selective for either ion.
|
be224e2e-60cb-47db-98bb-cab9bae2bf97
| 2 |
A model is proposed containing a shunt-resistance element whose resistance is a step function of PD. This model can mimic the responses of the tissue and provides a working model for the SPD.
|
b935ee9d-fb8c-4271-8143-d3fd94785088
| 0 |
Cancer of the undescended or maldescended testis. An analysis of 45 cryptorchids (by history or examination) with a testicular cancer treated at Memorial Hospital, between 1934 and 1973, is presented. Twenty-five patients had the cryptorchid state repaired at ages four to 27 years, either spontaneously or by orchiopexy or hormonal therapy.
|
b935ee9d-fb8c-4271-8143-d3fd94785088
| 1 |
Ipsilateral (24) or contralateral (one) intrascrotal testis tumors developed four to 47 years later. Twenty cryptorchid patients presented with ipsilateral inguinal (eleven), abdominal (seven), or contralateral intrascrotal (two) tumors. There were 18 pure seminomas, 17 embryonal carcinomas, nine teratocarcinomas, and one reticulum cell sarcoma.
|
b935ee9d-fb8c-4271-8143-d3fd94785088
| 2 |
Five year survival rates as estimated by the product-limit method were 60% for the unrepaired cases and 41% for the repaired cases. The survival seems to follow histologic type and anatomical stage, whether the testis is within the scrotum or not. Five year survival similarly estimated was 78% in the seminomas and 29% in the other tumors.
|
b935ee9d-fb8c-4271-8143-d3fd94785088
| 3 |
Twelve of thirteen survivors (including nine with seminoma) received postoperative irradiation to the regional lymphatics and eleven were without recurrent tumor for periods ranging from six to 28 years.
|
3f05777e-af89-41e7-9dcd-0ac653f493d8
| 0 |
Use of protease inhibitor (trasylol) and heparin in cardiorespiratory resuscitation. II. Gasometric investigations of arterial blood. The purpose of the present work was to assess the effect of trasylol--an inhibitor of proteases--and heparin on gasometric values in arterial blood during cardio-respiratory resuscitation. The investigations were carried out on rabbits in three experimental groups.
|
3f05777e-af89-41e7-9dcd-0ac653f493d8
| 1 |
In group I the simplest resuscitation procedures were applied: artificial respiration with AMBU self-expanding bag and heart massage. In group II oxygen was given for respiration, heart massage was applied, cardiac, vasoactive and alkalinizing drugs were given. Group III received the above drugs and procedures but trasylol and herparin were used additionally.
|
3f05777e-af89-41e7-9dcd-0ac653f493d8
| 2 |
Cardiac arrest was obtained by means of acute hypoxia following suxamethonium administration. The investigations showed that in groups I and II despite resuscitation management arterial hypoxaemia and metabolic acidosis persisted while in group III a certain return of normal gasometric values was observed and the animals in this group survived the experiment.
|
d150dc15-987f-4cab-b5eb-0a3e3f094cd5
| 0 |
Porcine malignant hyperthermia induced by halothane and succinylcholine: failure of treatment with procaine or procainamide. Metabolic, hemodynamic and neuroendocrine responses to the combined use of halothane and succinylcholine (SCh) were measured in five normal swine and five swine susceptible to malignant hyperthermia (MH). Constant-volume ventilation was used, and no therapy was instituted.
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d150dc15-987f-4cab-b5eb-0a3e3f094cd5
| 1 |
The overall response in susceptible swine was fulminant, in that it involved the rapid onset of SCh-induced MH combined with the more severe metabolic, endocrine, and cardiovascular effects of halothane-induced MH. Maximal changes in VO2 were equivalent with either drug or both combined, while changes in lactate, potassium (K+), pH, and catecholamines were perhaps synergistic.
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d150dc15-987f-4cab-b5eb-0a3e3f094cd5
| 2 |
Utilizing similar measurements, procaine or procainamide was used in 20 susceptible swine in attempts to prevent MH initiated by halothane, SCh, or both. Recommended therapeutic doses of either drug did not prevent characteristic MH changes in oxygen consumption, cardiac output, lactate, K+, pH, catecholamines, or temperature.
|
be3e1ce2-2d4d-4255-aea3-c8ee36900421
| 0 |
[Comparative study of neuraminidases from "Diplococcus pneumoniae" and "Clostridium perfringens"]. Neuraminidases have been purified from the culture medium of two microorganisms, one aerobic, Diplococcus neumoniae, the other anaerobic, Clostridium perfringens. The enzymatic properties of the 2 neuraminidases have been studied (pH optimum; effect of cations; activity toward different substrates: neuraminyllactose, dilactaminyllacto-N-tetraose, gangliosides, alpha1-acid glycoprotein, Collocalia glycoprotein, ovine submaxillary mucin, porcin intestinal and human bronchial mucins).
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0c6b6824-c4d8-4509-97bb-db61e0ce9526
| 0 |
[Carbohydrate containing media for the detection of urease in "Klebsiella"]. Sone strains of Klebsiella pneumoniae and K. oxytoca grown on nutrient agar may appear "urease negative" in a Ferguson type reagent medium after a 24 h incubation at 37 degrees C. Amongst such 147 so called urease negative strains, urease has been detected within a few hours in 79 strains, when bacteria have grown on media containing carbohydrates (Kligler iron agar, Drigalski lactose agar, SS agar and Worfel-Ferguson sucrose medium).
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0c6b6824-c4d8-4509-97bb-db61e0ce9526
| 1 |
Acid production by carbohydrate fermentation increases urease production by Klebsiella: pH 4 is the most convenient pH for urease synthesis by these bacteria. The other 68 strains have been considered as urease-less Klebsiella. The best results are obtained from culture on Worfel-Ferguson sucrose medium: urea hydrolysis is positive--on an average-after 1 hour and 30 minutes when detected in a Ferguson type reagent medium, and after 2 hours and 35 minutes when detected in a Christensen reagent medium.
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a8a44e14-cbd3-4a4c-9e02-9bc18aa24d4e
| 0 |
[Ferrous ion oxidation and uranium solubilization from a lowgrade ore by "Thiobacillus ferrooxidans" (author's transl)]. The microbiological oxidation of ferrous ion and the extraction of uranium from a low-grade ore has been studied using an adapted strain of Thiobacillus ferrooxidans. The effect of temperature, pH, volumetric oxygen transfer coefficient, K1a, and aeration number, Ia, on the activity of the microorganism has been determined.
|
a8a44e14-cbd3-4a4c-9e02-9bc18aa24d4e
| 1 |
The activation energy for ferrous iron oxidation was calculated to be - 13.9 +/- 0.1 kcal/mole and inactivation (thermal death of bacteria) 53.3 +/- 0.2 kcal/mole. Temperature coefficient, Q10, was estimated to be 1.8. Uranium extraction varied between 80 and 100%.
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a76757e1-8008-4bf8-b39c-94352db79009
| 0 |
Ethanol and galactose metabolism as influenced by 4-methylpyrazole in alcoholics with and without nutritional deficiencies. Preliminary report of a new approach to pathogenesis and treatment in alcoholic liver disease. 4-Methyl pyrazole (4-MP, a specific inhibitor of alcohol dehydrogenase) reduced ethanol elimination by 30-50% and completely removed the ethanol-induced inhibition of galactose elimination in 2 control subjects.
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a76757e1-8008-4bf8-b39c-94352db79009
| 1 |
Ethanol elimination was accelerated in 2 alcoholics with adequate nutrition, but the effect of 4-MP was comparable to that in controls. In 2 other alcoholic subjects, who reported poor nutritional intake, intermediate rates of ethanol elimination were observed and 4-MP had almost no effect on ethanol or galactose elimination.
|
a76757e1-8008-4bf8-b39c-94352db79009
| 2 |
These results suggest that alcohol abuse may result in an increased contribution to ethanol elimination by pathways other than that involving alcohol dehydrogenase (ADH) and that the decreased contribution from ADH, possibly potentiated by inadequate nutrition, may diminish the ethanol-induced shift in the NAD-coupled redox state. Since liver damage produced by alcohol abuse is believed to be related to changes from the normal redox state caused by ethanol, these results may explain why alcoholic liver damage is uncommon in alcoholics living on a marginal diet.
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a76757e1-8008-4bf8-b39c-94352db79009
| 3 |
Since 4-MP effectively eliminates the ethanol-induced shift in the redox state, a therapeutic trial with 4-MP in alcoholics with a high risk for liver disease is indicated.
|
b07828fc-a4cf-439a-bf46-3cfb0be4dbfb
| 0 |
A method for the regulation of microbial population density during continuous culture at high growth rates. A method for the continuous culture of microorganisms is described which employs growth-dependent pH changes to control the rate of addition of fresh medium to a culture vessel. The apparatus (the "phauxostat") supports, at constant pH, long-term continuous culture at rates near or at the maximum of which the organisms are capable.
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b07828fc-a4cf-439a-bf46-3cfb0be4dbfb
| 1 |
The buffering capacity of the inflowing medium determines the steady-state population density of the culture, but the rate of growth is independent of the buffering capacity. The fundamental theory of operation is tested and some basic parameters of growth are estimated using Escherichia coli B growing continuously in media containing glucose, glycerol or DL-lactate.
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904d915a-e84e-4030-8929-fd4544a1fdaf
| 0 |
Pyruvate fermentation in Rhodospirillum rubrum and after transfer from aerobic to anaerobic conditions in the dark. The fermentative metabolism of Rhodospirillum rubrum (strain Ha, F1, S1) was studied after transfering the cells from aerobic to anaerobic dark culture conditions. Pyruvate was metabolized mainly to acetate and formate, and to a lesser extent to CO2 and priopionate, by all strains.
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904d915a-e84e-4030-8929-fd4544a1fdaf
| 1 |
Therefore, pyruvate formate lyase would appear to be the characteristic key enzyme of the dark anaerobic fermentation metabolism in R. rubrum. Strain F1 and S1 metabolized the formate further to H2 and CO2. It is concluded that this cleavage was catalysed by a formate hydrogen lyase system. Strain Ha was unable to metabolize formate.
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904d915a-e84e-4030-8929-fd4544a1fdaf
| 2 |
The cleavage of formate and the synthesis of poly-beta-hydroxy-butyric acid were increased by a low pH value (approximately 6.5). Fermentation equations and schemes of the pyruvate metabolism are discussed.
|
464f92e3-378d-41ab-acf8-9938b662a51f
| 0 |
The influence of foster-home care on psychiatric patients. Adult patients placed into foster families by six administrations in three provinces of Canada were oberved at time of placement and followed up 18 months later. Over this period, they exhibited a substantial decline in symptoms-almost as great as with similar patients retained in the hospital.
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464f92e3-378d-41ab-acf8-9938b662a51f
| 1 |
However, there was virtually no improvement in social functioning, despite the fact that the use of foster homes has been advocated mainly for the resocialization that was expected to occur there. In discussing the reasons for this paradoxical finding, recommendations are offered regarding the use of foster homes by mental health administrations.
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e249f301-6064-4ae4-b876-a239ec07a49c
| 0 |
Sialic acid in thyroglobulin. II. Influence of sialic acid on ionization of tyrosine residues. During electrophoresis in polyacrylamide gel at pH 9-5, it was noticed that sialic acid-poor thyroglobulin contains fewer low molecular weight fragments than sialic acid-rich thyroglobulin. Splitting off of sialic acid diminishes thenumber of phenolic groups of tyrosine, MIT, DIT and T4, which dissociate below pH 12-5. This phenomenon was interpreted as a result of lowered hydrophilia of these regions of the thyroglobulin molecule which contains tyrosine and its iodinated derivatives.
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1788b7b3-e555-40e6-95cd-2e39d5c031c5
| 0 |
Prevention of experimental gastric ulcers in rats by dial derivatives. In 111 rats divided into 5 groups, Ipronal (5-allyl-5-(beta-hydroxypropyl)-barbituric acid) protected rats from development of experimental ulceration of the gastric mucosa twice as effectively as diallylbarbituric acid and compound D2H (5-isopropyl-5-(beta-hydroxypropyl)-barbituric acid). Compound D1S (alpha-allophanyl-alpha-allyl-gamma-valerolactone) was devoid of this action.
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603a1ea4-72d5-4b7c-9066-fe10a2c49e82
| 0 |
Kawasaki disease. Relationship with infantile periarteritis nodosa. Until 1972, Kawasaki disease, or acute febrile infantile mucocutaneous lymph node syndrome (MCLS), was considered in Japan to be a nonfatal disease with a favorable prognosis. Based on the findings from two autopsy cases of MCLS, we believe that sudden and unexpected death during convalescence may be due to arterial lesions, especially those involving the coronary artery, that resemble those of periarteritis nodosa.
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603a1ea4-72d5-4b7c-9066-fe10a2c49e82
| 1 |
Of 29 autopsy cases of MCLS, gathered from all over Japan, all exhibited arteritis lesions (eg, aneurysm due to coronary arteritis). Such vascular pathological findings may in fact represent the same entity as infantile periarteritis nodosa. Whether infantile periarteritis nodosa can be identified with the adult type is still debatable.
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603a1ea4-72d5-4b7c-9066-fe10a2c49e82
| 2 |
The particular manifestations of infantile periarteritis nodosa might be related to severe vasculitis. Autopsy cases of infantile periarteritis nodosa without MCLS manifestations are being collected and studied.
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47a2e51a-d64f-4c38-b6cf-2577227767ef
| 0 |
Portal hypertension and gastric lesions in the rat. Gastric lesions occurred spontaneously and were increased in number by seven hours of restraint stress in rats with portal vein constriction (PVC). Vagotomy and pyloroplasty protected the congested stomach from erosion formation with stress. Major weight loss occurred two days after PVC, but not thereafter.
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47a2e51a-d64f-4c38-b6cf-2577227767ef
| 1 |
Platelet counts were decreased in intact and splenectomized rats with portal hypertension, but prothrombin time, partial thromboplastin time, and fibrinogen were unaffected, and histological stains failed to demonstrate thrombin in the gastric blood vessels. The oxygen pressure (PO2) of the gastric luminal fluid was decreased at day 2, but was normal at day 4 after PVC.
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47a2e51a-d64f-4c38-b6cf-2577227767ef
| 2 |
Hypersection of acid and abnormal acid equilibration were not observed in the stomach. Gastric congestion, weight loss, and possibly portasystemic shunting of blood contributed to the higher incidence of gastric erosions with portal hypertension.
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c227e790-7434-48d3-9ced-a30a6b925418
| 0 |
Scanning electron microscopy studies in muscular dystrophy. Scanning electron microscopy of unmanipulated erythrocytes from patients with myotonic dystrophy or Duchenne dystrophy and patients who were Duchenne carriers showed a large increase in the number of stomatocytes over the number in normal controls. No specific morhologic changes that would differentiate any of the dystrophic patients from one another were seen. Adverse conditions such as washing before fixation or extreme pH produced a greater change in erythrocytes from these patients than in those from normal controls.
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f473de7e-ba73-4896-a272-7feb876a9d47
| 0 |
Comparison of the biological effects in rat of high doses of two 4-amino-7-chloroquinoline derivatives: chloroquine and glafenine. When given orally in elevated but nonlethal doses (150 to 450 mg/kg, on 2 consecutive days), glafenine induces in rats (body weight 100 g) a transient nephritis with an increase in blood urea, hypertrophy of adrenals, and some changes in the serum proteinogram.
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f473de7e-ba73-4896-a272-7feb876a9d47
| 1 |
These effects do not appear to be due to the 4-amino-7-chloroquinoline structure from which glafenine is derived, as they are not observed with the structural analogue chloroquine given at equimolar doses under the same conditions. Further, they do not appear to be due to glycerol, the by-product of metabolic glafenine hydrolysis.
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f473de7e-ba73-4896-a272-7feb876a9d47
| 2 |
The responsible molecule appears to be either glafenine itself or its acid metabolite 4-(0-carboxyphenylamino) 7-chloroquinoline.
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 0 |
A comparative study on the irreversible binding of labeled halothane trichlorofluoromethane, chloroform, and carbon tetrachloride to hepatic protein and lipids in vitro and in vivo. 1) After intraperitoneal injection of labeled CCl4, CHCl3, and halothane in mice, 14C is preferentially bound to liver endoplasmic protein and lipid.
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 1 |
A considerable activity is also associated with mitochondrial constituents. Maximal protein binding (nmol/mg): CCl4: 2.8 (0.5 hrs); CHCl3: 11.5 (6 hrs); halothane: 5 (6 hrs). Lipid binding: CCl4: 6.4 (5 min); CHCl3: 8 (4 hrs); halothane:
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 2 |
13.5 (2 hrs). The form of the binding curves in microsomal and mitochondrial protein and lipid differed with the individual haloalkanes. 2) The irreversible (covalent) binding of 14C from labeled haloalkanes in anaerobic suspensions of isolated rabbit liver microsomes and NADPH after 30 min was for protein (lipid) (nmol/mg):
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 3 |
CCl4: 15 (58); CHCl3: 3.4 (3.2); halothane: 2.3 (10); trichlorofluoromethane: 6.5 (30). Anerobic incubation favored dehalogenation, but CHCl3 metabolism and irreversible binding requires oxygen. The greatest differences in the in vitro "covalent" binding rates were observed with CHCl3 in rat, mouse, and rabbit.
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 4 |
3) Altered microsomal cytochrome P-450 concentrations in newborn animals, or produced by pretreatment of rats with phenobarbital, 3-methylcholanthrene (MC), or CoCl2 effected similar, but not proportional changes in the rates of irreversible protein and lipid binding. Upon addition of CCl4 the difference of light absorption of reduced liver microsomes from MC-pretreated rats containing cytochrome P-448 appeared at 452 nm.
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 5 |
The irreversible binding rate in these microsomes was also increased. The small accleration in irreversible binding in liver microsomes from rats pretreated with isopropanol is not proportional to the high increase of CCl4 toxicity. 4) Practically no binding to added, soluble albumin or RNA was observed in microsomal incubates.
|
1d2e6ad9-1cfe-44e2-b2fa-a8f35d88cd48
| 6 |
However, 14C is bound to the nicotine-adenine dinucleotides of the NADPH system. All haloalkanes produced a similar increase of NADPH oxidation in incubates of rabbit liver microsomes and NADPH.
|
d48f8af4-ce65-4854-99e4-73de95ebe488
| 0 |
Interaction of thermostable direct hemolysin of Vibrio parahaemolyticus with human erythrocytes. The interaction between thermostable direct hemolysin produced by Vibrio parahaemolyticus WP-1 and human erythrocytes was studied. The lysis of human erythrocytes by the hemolysin was dependent of temperature and no hemolysis occurred at low temperature (0-4 C), but the hemolysin was adsorbed on human erythrocytes even at low temperature.
|
d48f8af4-ce65-4854-99e4-73de95ebe488
| 1 |
No hemolysis was observed when antihemolysin antiserum was mixed with the hemolysin and human erythrocytes at zero time. On the other hand, lysis of the cells by hemolysin was not completely inhibited when the antiserum was added during the lag time and the inhibitory effect decreased with delay in the time of addition of antiserum.
|
d48f8af4-ce65-4854-99e4-73de95ebe488
| 2 |
The inhibitory effect of the antiserum decreased with increase in the incubation temperature, increase in the concentration of divalent cations, and decrease in pH. These results suggest that lysis of human erythrocytes by the hemolysin is at least a two-step process consisting of adsorption of the hemolysin to human erythrocytes and the step(s) following adsorption.
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8725428b-245e-4a25-8e19-b6ee702f8418
| 0 |
Deoxyribonucleic acid polymerases of Euglena gracilis. Purification and properties of two distinct deoxyribonucleic acid polymerases of high molecular weight. Two DNA polymerases of high molecular weight, pol A (mol.wt. 190 000) and pol B (mol.wt. 240 ooo), have been purified 6300-fold and 1600-fold respectively from an extramitochondrial supernatant of a bleached strain of Euglena gracilis.
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8725428b-245e-4a25-8e19-b6ee702f8418
| 1 |
They have very similar requirements when assayed with an 'activated'-DNA primer-template [the optimum conditions of pH and ionic (K+ and Mn2+) composition being 7.2, 25 mM and 0.2 mM respectively]. 0.2 mM-Mn2+ was about 1.5-2-fold as effective as 2 mM-Mg2+, owing to substrate activation by deoxyribonucleoside 5'-triphosphates in the presence of Mn2+.
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8725428b-245e-4a25-8e19-b6ee702f8418
| 2 |
Km values for the triphosphates in the absence of activation were about 10(-6)M with Mn2+ and 8 X 10(-6) M with Mg2+ for both enzymes. They were inhibited to the same extent by N-ethylmaleimide, novobiocin and o-phenanthroline, but differed in their chromatographic behaviour on DEAE-cellulose and in their electrophoretic mobilities on polyacrylamide gel.
|
8725428b-245e-4a25-8e19-b6ee702f8418
| 3 |
No evidence was found for the existence in these cells of a DNA polymerase of low molecular weight, but there were indications that a third enzyme of high molecular weight might exist.
|
5553f5e0-b0ea-4222-bcf5-77202aff5c56
| 0 |
Deoxyribonucleic acid polymerases of Euglena gracilis. Primer-template utilization of and enzyme activities associated with the two deoxyribonucleic acid polymerases of high molecular weight. The two high-molecular-weight DNA polymerases from Euglena gracilis, pol A (mol. wt. 190 000) and pol B (mol. wt. 240 000), were differentiated on the basis of associated enzymic activities and primer-template utilization.
|
5553f5e0-b0ea-4222-bcf5-77202aff5c56
| 1 |
Neither enzyme had endodeoxyribonuclease activity, but pol B, like pol B of yeast and the corresponding enzyme from Tetrahymena pyriformis, exhibited at least one other nuclease activity directed against denatured DNA and the RNA of an RNA-DNA hybrid. These nuclease functions preferred an alkaline pH and Mg2+.
|
5553f5e0-b0ea-4222-bcf5-77202aff5c56
| 2 |
Pol B also exhibited nucleoside diphosphokinase activity. Both enzymes were active with 'activated' DNA and poly[d(A-T)] as primer-templates and were sensitive, especially pol B, to inhibition by excess of native or heat-denatured DNA. Pol B also utilized oligo[d(T)] and poly(A) templates under certain conditions, whereas pol A exhibited only slight activity with poly[d(A)].
|
5553f5e0-b0ea-4222-bcf5-77202aff5c56
| 3 |
(U)6 was not used as a primer by either enzyme.
|
bb400470-1e70-4d9a-b079-8e0424d76575
| 0 |
Purification and properties of 6-phosphogluconate dehydrogenase from rabbit mammary gland. 1. 6-Phosphogluconate dehydrogenase from rabbit mammary gland was purified to homogeneity by the criterion of polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The molecular weight of the subunit is 52 000. The enzyme was purified 150-fold with a final specific activity of 20 mumol of NADP+ reduced/min per mg of protein and overall yield of 3%.
|
bb400470-1e70-4d9a-b079-8e0424d76575
| 1 |
The molecular weight of the native enzyme is estimated to be 104 000 from gel-filtration studies. The final purification step was carried out by affinity chromatography with NADP+-Sepharose. 2. The Km values for 6-phosphogluconate and NADP+ are approx. 54 muM and 23 muM respectively.
|
bb400470-1e70-4d9a-b079-8e0424d76575
| 2 |
3. Citrate and pyrophosphate are competitive inhibitors of the enzyme with respect to both 6-phosphogluconate and NADP+. 4. MgCl2 affects the apparent Km for NADP+ at saturating concentrations of 6-phosphogluconate.
|
4e3c06d8-df7f-4ba7-ac6c-8b1c794236e9
| 0 |
Protein chromatography on adsorbents with hydrophobic and ionic groups. Some properties of N-(3-carboxypropionyl)aminodecyl-sepharose and its interaction with wheat-germ aspartate transcarbamoylase. 1. The charge state of two derivatives of Sepharose prepared by the CNBr activation method were studied by acid-base titration and by ion-exchange chromatography.
|
4e3c06d8-df7f-4ba7-ac6c-8b1c794236e9
| 1 |
Dodecyl-Sepharose exhibited cationic groups (21mumol/ml of settled gel; pKa=9.6) that were tentatively assigned to the coupling isourea group. 2. CPAD-Sepharose [N-(3-carboxypropionyl)aminodecyl-Sepharose] has anionic (carboxyl) groups (pKa=4.5) and cationic groups (pKa=9.6) in roughly equal concentrations (e coupling group.
|
4e3c06d8-df7f-4ba7-ac6c-8b1c794236e9
| 2 |
CPAD-Sepharose is slightly negatively charged at pH 7.0 and substantially negatively charged at pH 8.5. 3. The pKa values of dodecyl-Sepharose and CPAD-Sepharose are unaffected by a 100-fold increase in the concentration of KCl. 4. CPAD-Sepharose has considerable affinity for wheat-germ aspartate transcarbamoylase at pH 8.5
|
4e3c06d8-df7f-4ba7-ac6c-8b1c794236e9
| 3 |
when the adsorbent and enzyme are both negatively charged. The interaction involves the C10 chain but is relatively moderate compared with C10 chains associated only with positive charge. 5. Desorption of the enzyme adsorbed to CPAD-Sepharose can be achieved by raising the pH to increase the electrostatic repulsion, or by introducing the detergent sodium deoxycholate.
|
4e3c06d8-df7f-4ba7-ac6c-8b1c794236e9
| 4 |
Acetone and butan-1-ol also weaken the adsorption at pH 8.5. 6. High concentrations of sodium acetate or sodium phosphate induced the enzyme to bind more tightly to CPAD-Sepharose. 7. These results are discussed in terms of a 'repulsion-controlled' model or hydrophobic chromatography.
|
ddb69d27-7e61-4d84-a3cd-b8e60d1fc736
| 0 |
The effect of acid proteinase inhibitors on chicken pepsin. 1. The activity of chicken pepsin was partially inhibited by dimethyl-(2-hydroxy-5-nitrobenzyl)sulphonium bromide, but was unaffected by p-bromophenacyl bromide. 2. In the presence of Cu2+, diazoacetylnorleucine methyl ester completely inactivated chicken pepsin with the incorporation of 1 mol/mol.
|
ddb69d27-7e61-4d84-a3cd-b8e60d1fc736
| 1 |
The mechanism of the reaction was similar to that with pig pepsin. 3. Chicken pepsin was completely inactivated by 2-diazo-4-bromoacetophenone in the presence of Cu2+. 4. Chicken pepsin was almost completely inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane at 25 degrees C, 3-4mol of inhibitor/mol being incorporated.
|
ddb69d27-7e61-4d84-a3cd-b8e60d1fc736
| 2 |
The reaction at 10 degrees C was investigated briefly. 5. Calf chymosin was inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane at 10 degrees C, the incorporation of 1 mol/mol being required for complete inhibition. 6. The characteristics of the reactions of chicken pepsin with the above compounds were compared with those of other acid proteinases.
|
82362586-3a93-4fdf-8534-586edbaca919
| 0 |
The purification and properties of pig spleen phosphofructokinase. Pig spleen phosphofructokinase has been purified 800-fold with a yield of 17%. Two isoenzymes that appear to be kinetically identical can be separated by DEAE-cellulose column chromatography. In common with the enzyme from other mammalian sources, the spleen enzyme has a pH optimum of 8.2
|
82362586-3a93-4fdf-8534-586edbaca919
| 1 |
. At pH 7.0 it displays sigmoidal kinetics with respect to fructose 6-phosphate concentration but its co-operative behaviour is very dependent on pH, protein concentration and the concentration of MgATP. MgGTP and MgITP can replace MgATP as phosphate donors but, unlike MgATP, these nucleotides do not cause significant inhibition.
|
82362586-3a93-4fdf-8534-586edbaca919
| 2 |
Mn2+ and Co2+ (as the metal ion-ATP complexes) act as cofactors and in the free form are far more inhibitory than free Mg2+. The spleen enzyme responds to a wide variety of potential effector molecules: ADP, AMP, cyclic AMP, aspartate, NH4+, fructose 6-phosphate, fructose 1,6-diphosphate and Pi all act as either activators or protectors, whereas Mg-ATP, Mg2+, citrate, phosphoenol-pyruvate and the phosphoglucerates are inhibitors.
|
2afa6aa3-00f7-4a9e-a2bf-b7f35b500068
| 0 |
The effect of disulfiram on the aldehyde dehydrogenases of sheep liver. 1. The effect of disulfiram on the activity of the cytoplasmic and mitochondrial aldehyde dehydrogenases of sheep liver was studied. 2. Disulfiram causes an immediate inhibition of the enzyme reaction. The effect on the cytoplasmic enzyme is much greater than on the mitochondrial enzyme.
|
2afa6aa3-00f7-4a9e-a2bf-b7f35b500068
| 1 |
3. In both cases, the initial partial inhibition is followed by a gradual irreversible loss of activity. 4. The pH-rate profile of the inactivation of the mitochondrial enzyme by disulfiram and the pH-dependence of the maximum velocity of the enzyme-catalysed reaction are both consistent with the involvement of a thiol group.
|
2afa6aa3-00f7-4a9e-a2bf-b7f35b500068
| 2 |
5. Excess of 2-mercaptoethanol or GSH abolishes the effect of disulfiram. However, equimolar amounts of either of these reagents and disulfiram cause an effect greater than does disulfiram alone. It was shown that the mixed disulphide, Et2N-CS-SS-CH2-CH2OH, strongly inhibits aldehyde dehydrogenase. 6.
|
2afa6aa3-00f7-4a9e-a2bf-b7f35b500068
| 3 |
The inhibitory effect of diethyldithiocarbamate in vitro is due mainly to contamination by disulfiram.
|
c6a2f32f-97f2-4239-bee5-5d2f4fdc6792
| 0 |
A reporter group delivery system with both absolute and selective specificity for thiol groups and an improved fluorescent probe containing the 7-nitrobenzo-2-oxa-1,3-diazole moiety. 1. 4-(N-2-Aminoethyl2'-pyridyl disulphide)-7-nitrobenzo-2-oxa-1,3-diazole (compound I) was synthesized and evaluated as a fluorescent labelling reagent for thiol groups.
|
c6a2f32f-97f2-4239-bee5-5d2f4fdc6792
| 1 |
2. The design of compound (I) as one example of a general type of reporter group delivery reagent (2-pyridyl-S-S-X, where X contains an environmentally sensitive spectroscopic probe) is discussed. 3. The electronic absorption spectrum of compound (I) was determined over a wide range of pH and the spectral changes that accompany its reaction with low-molecular-weight thiols, e.
|
c6a2f32f-97f2-4239-bee5-5d2f4fdc6792
| 2 |
g. L-cysteine, and with papain (EC 3.4.22.2) and bovine serum albumin are discussed. 4. A new value of epsilon343 for 2-thiopyridone (Py-2-SH) was determined as 8.08 X 10(3) +/- 0.08 X 10(3)M-1-cm-1. 5. Spectral analysis of the reactions of compound (I) with L-cysteine and with papain (in the pH range 3.5
|
c6a2f32f-97f2-4239-bee5-5d2f4fdc6792
| 3 |
-8.0) showed that even under equimolar conditions the reaction (thiol-disulphide interchange to release Py-2-SH) is essentially stoicheimoetric and probably proceeds by specific attack at the sulphur atom distal from the pyridyl ring of compound (I). 6. The fluorescence-emission spectra of compound (I) and of the products of its reaction with papain and with ficin (EC 3.4.22.3
|
c6a2f32f-97f2-4239-bee5-5d2f4fdc6792
| 4 |
) were determined. Compound (I) is highly fluorescent in aqueous solution. Excitation within the intense visible absorption band (lambda max. 481 nm, epsilon max. 2.52 X 10(4)M-1-cm-1) provides green fluorescence with an emission maximum at 540 nm. Both papain and ficin labelled by reaction with compound (I) are characterized by fluorescence-emission maxima (535 nm and 530 nm respectively) of even higher intensity.
|
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