Occurrence and enterotoxigenicity of F17 fimbriae bearing Escherichia coli from calf diarrhoea.
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Animals↗
Biomedical subjects
V K Sharma
Publications and source records attributed to V K Sharma.
Biological clocks: mechanisms and developments.
Almost all organisms ranging from unicellular protists to mammals were found to show biological rhythms. Many workers have performed various kinds of experiment to understand the mechanism as well as to find the origin of the clock responsible for these rhythms. However, there is no doubt about the existence of a biologically controlled clock in almost all organisms; yet its origin and mechanism still remain a mystery. Many theories have been put forward to explain the mechanism of these biological clocks and it seems that the cell membrane may play a key role. The existence of a very high electric field of the order of 10(5) V cm-1 across the cell membrane may have some role in the mechanism of the biological clock. Of all the factors which have the effects on biological rhythms, light and temperature are found to be the most common. Also, the study of these biological clocks can help to solve the sleeping problems of international travellers and shift workers as well as to improve diagnosis, cure and prevention from diseases.
Animals↗
Modulation of cytosolic free calcium concentration by alpha 1-adrenoceptors in rat atrial cells.
The effects of alpha 1-adrenoceptor stimulation by phenylephrine (PE) and beta-adrenoceptor stimulation by isoprenaline (ISO) on Ca2+ current (ICa) and free intracellular Ca2+ concentration ([Ca2+]i) were studied in isolated atrial myocytes from rat hearts. PE did not significantly affect the magnitude of ICa, whereas large increases of peak ICa were observed in response to ISO. In electrically driven cells, PE evoked a concentration-dependent, gradual increase in diastolic [Ca2+]i and, initially, an increase in the height of peak [Ca2+]i transients. When the diastolic [Ca2+]i was increased to a greater extent, the amplitude of [Ca2+]i transients was decreased. Simultaneous measurements of [Ca2+]i and membrane potential showed that the increase in diastolic [Ca2+]i was associated with a depolarization of the membrane, and the greater amplitude of [Ca2+]i transients with a prolongation of the action potential (AP). The PE-induced increase in diastolic [Ca2+]i was eliminated when the cells were voltage-clamped at the original resting membrane potential (RP); under these conditions, an increase in [Ca2+]i transients was observed in response to PE. ISO usually caused larger increases in the amplitude of [Ca2+]i transients with only minor changes in diastolic [Ca2+]i. These results suggest that PE and ISO increase the amplitude of [Ca2+]i transients in rat atrium in different ways. The increase in [Ca2+]i transients in response to beta-adrenoceptor stimulation is commonly thought to be mediated by a greater conductance of voltage-dependent Ca2+ channels causing a greater Ca2+ influx and a release of more Ca2+ from the sarcoplasmic reticulum during the AP. The increase in diastolic [Ca2+]i in response to PE is probably a consequence of the depolarization of the membrane, possibly involving the voltage-dependent Na(+)-Ca2+ exchange mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenergic alpha-Agonists↗
Distribution of malathion in body tissues and fluids.
Six cases of suspected poisoning were studied. The various body tissues and fluids of all the cases were analysed and malathion was found positive. The quantitative analysis was performed using high performance liquid chromatography. The distribution of malathion was studied in lungs, liver, kidneys, spleen, brain, heart, blood, muscles, urine and gastric contents.
Adolescent↗
Human giardiasis: correlation of specific secretory IgA levels in duodenal fluid to the severity of disease and infestation by Giardia lamblia.
Giardia lamblia specific secretory immunoglobulin A (sIgA) levels in the duodenal fluid of adult giardiasis cases are reported for the first time. The sIgA levels in the study group were found to be significantly higher (p less than 0.01) than in the 20 age- and sex-matched controls comprising cases classified as non-ulcerative dyspepsia who did nor reveal any G. lamblia in their stools and the duodenal fluid. An inverse relationship between the clinical severity of giardiasis and the level of sIgA in the duodenal fluid was noted. Cases with a higher trophozoite load in duodenal aspirate tended to be associated with envanescent G. lamblia-specific antibodies.
Adult↗
Nutritional modulators of lipoprotein metabolism in patients with risk factors for coronary heart disease: diet and moderate exercise trial.
To study the role of diet as a risk factor for coronary heart disease (CHD), 463 adults (25-65 years, 419 males) at risk of or with CHD were assigned to group A (n = 231) receiving a cardiovasoprotective diet or group B (n = 232) receiving a normal diet in a randomized, single-blind fashion. Age, sex, risk factors and incidence of CHD were comparable between the two groups. Group A received a significantly higher percentage of calories in relation to complex carbohydrates, vegetable proteins, polyunsaturated fatty acids, and had a higher polyunsaturated:saturated fatty acid (P:S) ratio compared to control group B, which received more saturated fat and cholesterol. Group A also received more soluble dietary fiber and magnesium (Mg) and was physically more active than group B. Exercise and dietary adherence were tested by a questionnaire. After 12 weeks, results indicated a significant decrease in mean serum total cholesterol (9.0 vs 3.1%), low-density-lipoprotein cholesterol (LDL-C) (9.8 vs 3.8%) and triglyceride (11.1 vs 5.4%), and an increase in serum Mg (8.5%) in the intervention group compared to initial levels. No significant changes in mean levels were noted in the control group. Body weight significantly decreased and physical activity was significantly higher in the intervention group compared to the control group during the 12-week followup on similar intakes of energy. There were insignificant changes in high-density-lipoprotein cholesterol (HDL-C) in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Peripheral T lymphocytes and their subsets in cutaneous tuberculosis.
Fifty-four patients with cutaneous tuberculosis, consisting of 23 with lupus vulgaris, 22 with scrofuloderma, and nine with verrucosa cutis, were investigated for cell-mediated immunity, through estimation of peripheral total T lymphocytes (CD3+), CD4+ (helper/inducer), and CD8+ (cytotoxic/suppressor) lymphocytes, by immunohistochemical staining of peripheral blood smears, using specific monoclonal antibodies and the alkaline phosphatase-antialkaline phosphatase (APAAP) method. Absolute values of total T lymphocytes (CD3+), and CD4+ and CD8+ subsets, were found to be significantly raised in scrofuloderma, but the percentage values and the CD4+/CD8+ ratio remained unaltered. In tuberculosis verrucosa cutis, only the percentage of the CD8+ subset of T lymphocytes was found to be significantly lowered, and this altered the CD4+/CD8+ ratio. No significant change was observed in the peripheral blood T cells and their subpopulations in patients suffering from lupus vulgaris.
Adolescent↗
Reaction in leprosy: acute phase reactant response during and after remission.
Sera from 25 patients with type 1 (Lepra), upgrading and downgrading, and type 2 (erythema nodosum leprosum [ENL]) reactions were assayed, during the reaction and after its clinical remission, for changes in levels of alpha-1-antitrypsin (A1A) and C-reactive protein (CRP). The results were compared with those from normal healthy adults and patients of leprosy without history and/or clinical evidence of reaction. The A1A levels correlated better with changes in status of type 1 reaction; whereas CRP levels correlated well with alterations in type 2 reactions and were definitely superior to A1A in this situation for monitoring the course of these episodes.
Adolescent↗
Mechanism of extracellular ATP-induced increase of cytosolic Ca2+ concentration in isolated rat ventricular myocytes.
1. Changes in the cytosolic Ca2+ concentration ([Ca2+]i) of isolated rat ventricular myocytes in suspension were measured in response to extracellular ATP using the fluorescent Ca2+ indicators Quin-2 and Fura-2. 2. ATP produced a concentration-, time- and Mg(2+)-dependent, biphasic increase of [Ca2+]i whereas slowly hydrolysable ATP analogues produced a slow, monophasic increase of [Ca2+]i and the non-hydrolysable ATP analogues were without effect. 3. Extracellular Ca2+ was required for the ATP-induced increase of [Ca2+]i and pre-treatment of the cells with caffeine, ryanodine, verapamil or nimodipine partially inhibited the [Ca2+]i increase. 4. Whole-cell patch-clamp experiments revealed that ATP activated an ionic current that had a linear current-voltage relationship with a reversal potential near O mV. Quinidine, a putative P2 purinergic receptor blocker, abolished the ATP-activated current. The ATP-activated current was Mg2+ dependent. 5. Associated with the ATP-activated current was cellular depolarization. In a physiological solution, ATP depolarized cells to the threshold for the firing of action potentials. In the presence of the voltage-activated ion channel blockers tetrodotoxin, 4-aminopyridine, caesium and nitrendipine, ATP depolarized cells to -44 +/- 6 mV from a resting potential of -66 +/- 4 mV (n = 11). 6. Sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis and autoradiography demonstrated that extracellular ATP stimulated the phosphorylation of several extracellular membrane-bound proteins. The phosphorylation of these proteins was concentration, time and Mg2+ dependent. Pre-treatment of cells with the slowly hydrolysable ATP analogues inhibited the ATP-induced phosphorylation. Adenosine 5'-O-3-thiotriphosphate (ATP gamma S) thiophosphorylated proteins with the same apparent molecular weight as the proteins phosphorylated by ATP. 7. These results suggest that the ATP-induced increase of [Ca2+]i is a result of the activation, possibly by protein phosphorylation, of a novel ion channel carrying inward current. The ATP-activated channel may be permeable to Na+ and Ca2+ and causes [Ca2+]i to rise. More importantly, this inward current depolarizes the cell to the threshold of inducing spontaneous firing of action potentials. The firing of action potentials results in the influx of Ca2+ through L-type Ca2+ channels which would trigger Ca2+ release from the sarcoplasmic reticulum and lead to the increase in [Ca2+]i.
Action Potentials↗
Na+ efflux mechanisms in ventricular myocytes: measurement of [Na+]i with Na(+)-binding benzofuran isophthalate.
We characterized the Na(+)-sensitive dye benzofuran isophthalate (SBFI) with fluorescence microscopy in isolated, adult rat ventricular myocytes. When cells were loaded with SBFI by incubation with 10 microM of the acetoxymethyl ester, fluorescence excitation spectra were markedly attenuated below 340 nm and the isoemissive point was blue shifted by approximately 25 nm when compared with spectra from SBFI acid in buffered solutions. Fluorescence intensity (49 +/- 3%) was partially released by permeabilization of the sarcolemma with digitonin, suggesting that one-half of the dye molecules are sequestered subcellularly in a compartment shown most likely to be mitochondrial. Intracellular Na+ concentration ([Na+]i) was determined by in situ calibration using cation-selective ionophores and was found to be 14 +/- 2 mM in cells studied at 37 degrees C. The relative importance of Na+ efflux mechanisms in myocytes was investigated. Substitution of Ca2+ and Mg2+ with EGTA in the superfusing medium resulted in a reversible rise of [Na+]i from 13 +/- 2 to 31 +/- 5 mM, which was blocked by 1 microM verapamil. Cellular efflux of Na+ after loading in this manner was found to be insensitive to blockade of Na(+)-Ca2+ exchange but was abolished when Na(+)-K(+)-ATPase was inhibited with zero extracellular K+ concentration. We conclude that SBFI can be used to measure [Na+]i in ventricular cells nondestructively and without impalement. Na+ efflux after loading by Ca2+ and Mg2+ withdrawal is mediated by the Na+ pump with no measurable contribution from Na(+)-Ca2+ exchange.
Animals↗
The natural history of neurotic disorder in an elderly urban population. Findings from the Liverpool longitudinal study of continuing health in the community.
A random community sample of 1070 subjects aged 65 years and over was interviewed at home using the GMS-AGECAT package and followed up three years later. Neurotic symptoms were common, but symptoms sufficient to reach 'case' level were much less frequent. The overall prevalence of neurotic 'cases' was 2.4% in year 0 and 1.4% in year 3. The incidence was estimated as a minimum of 4.4 per 1000 per year over the age of 65. Women were more likely to be 'cases' than men but not 'subcases', and there was a general decline in prevalence with increasing age, particularly for 'subcases'. Anxiety was the commonest neurotic subtype. After three years, 'cases' were shown not to persist, but this did not reflect wellness. There was a tendency still to have some symptoms, but the predominant symptom appeared to change, suggesting a possible chronic neurotic disorder with changing presentation over time. Depressive symptoms were closely associated with this presentation, suggesting that depression may be an important and integral part of a general, changing neurotic disorder.
Aged↗
Detection of a Mycobacterium leprae cell wall antigen in the urine of untreated and treated patients.
A total of 90 leprosy patients, 12 household contacts and 10 normal subjects were studied for the detection of Mycobacterium leprae cell wall antigen in urine using monoclonal antibody (ML30A2 IgG). In untreated multibacillary leprosy (BL-LL) the M. leprae cell wall antigen could be demonstrated in the urine of 14 (64%) patients by immunofluorescence (IF) and 22 (100%) by ELISA. In untreated paucibacillary leprosy (TT-BT), it could be demonstrated in 3 (11.5%) and in 13 (50%) patients by IF and ELISA methods respectively. All but 1 household contact (later confirmed to have BL leprosy) and all 10 normal subjects' urine was negative for M. leprae cell wall antigen by both methods. The same antigen was, however, demonstrated in urine of 50% paucibacillary patients who had received 6 months of treatment and in 68% multibacillary patients who had received 24 months of WHO recommended multidrug therapy. M. leprae cell wall antigen assays in urine will not be useful in the follow-up of leprosy patients on multidrug therapy.
Adolescent↗
Adenosine triphosphate content of Mycobacterium leprae by percoll buoyant density centrifugation.
Thirty nine untreated patients of bacilliferous leprosy with a mean bacteriological index of 4.8 and morphological index of 1.3% formed the study group. Adenosine triphosphate assay was carried out by (i) enzyme treatment method in 18 patients and (ii) percoll buoyant density gradient method in 21 patients. ATP content obtained by percoll buoyant density gradient method was significantly higher than that obtained by enzyme treatment method. Percoll buoyant density centrifugation for purification and isolation of bacilli from human leproma is simplier, quicker and can serve as an alternate method of enzyme treatment.
Adenosine Triphosphate↗
Malarial placental infection and low birth weight babies.
Two-hundred fifty-six mothers and their newborns were subjected to clinical and haematological tests for the evidence of malaria. Placentae of these were examined histopathologically for malarial parasites and malarial pigment. Forty six placentae showed scanty malarial pigment ingested by monocytes. These appearances were associated with focal syncytial necrosis and proliferation of cytotrophoblastic cells. Plasmodium falciparum was found in cord blood of six cases. The mean weight of newborns born to mothers having no evidence of malarial placental infection was 2.763 kg, while mean weight of newborns belonging to infected placentae was 2.143 kg. The difference was highly significant.
Birth Weight↗
Mast cell reactivity in lymphoma: a preliminary communication.
Fifty nodes of Hodgkin's disease, 50 of non-Hodgkin's lymphoma and 20 of reactive hyperplasia revealed varying degree of mast cell reactivity. It was maximum in reactive lymph nodes, sinuses and interfollicular areas being infiltrated more than zones. The number of mast cells was more in nodular sclerosis variety of Hodgkin's disease than other Rye-subtypes, and more in Hodgkin's group than non-Hodgkin's, out of the latter, the diffuse histiocytic lymphoma revealed higher number. Analysis of a larger series and follow-up of these patients are indicated to establish the possible reactionary nature of mast cell reactivity in lymphomas, and the prognostic bearing, if any.
Castleman Disease↗
Maxillary antrum involvement in multibacillary leprosy: a radiologic, sinuscopic, and histologic assessment.
Thirty patients having lepromatous leprosy (22 males, 8 females) and showing radiological involvement of the maxillary antrum were subjected to sinuscopy, biopsy, and histopathological examination. Radiological observations showed diffuse opacity in 33.3% of the sinuses, localized mucosal thickening in 28.6%, and generalized thickened mucosa in 38.1%. Sinuscopy revealed inflamed mucosa as the most common finding (40%), followed by ulcerative (26.7%) and granulomatous (10%) lesions of the mucosal lining. The mucosal thickening (localized or generalized) evident on radiology was always associated with granuloma formation and acid-fast bacilli in the histology. The presence of an external nasal deformity indicated a statistically significant chance of encountering mucosal involvement on sinuscopy and histopathology (p < 0.05). There was more chance of finding positive sinuscopic lesions in those patients with a bacterial index above 3+.
Adult↗
Laparoscopic cholecystectomy: experience in a district general hospital.
In many centres laparoscopic cholecystectomy has become the procedure of choice for symptomatic gallbladder stones. By comparison with conventional cholecystectomy it appears to be associated with minimal morbidity, shorter hospital stay, earlier return to work and a better cosmetic result. The present study reviews the results of the first 50 laparoscopic cholecystectomies performed at Altnagelvin Area Hospital.
Adult↗
Treatment of deep mycoses with itraconazole.
Four patients with deep mycoses were treated with itraconazole. Two patients had chromoblastomycosis, one patient each had aspergillosis and Rhinofacial zygomycosis. These patients were either resistant to or showed poor response to Amphotericin B and/or ketoconazole. After the initial clinical and mycological evaluation, itraconazole was given in a daily dose of 200 mg orally. All patients responded to the drug very well. No adverse effects attributable to itraconazole were detected.
Adult↗