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Biomedical subjects

S Jain

Publications and source records attributed to S Jain.

At least 487 records · Page 27Linked to original sources
PubMed1993

Corticotropin-dependent Cushing's syndrome in a patient with chronic renal failure--a rare association.

Corticotropin-dependent Cushing's syndrome was detected in a 32-year-old male suffering from membranous nephropathy and chronic renal failure. Cortisol dynamics revealed high basal cortisol, loss of circadian rhythm, and nonsuppressibility with low-dose dexamethasone. However, the latter was suppressible with high-dose dexamethasone. Treatment with ketoconazole led to a remarkable response both clinically and biochemically. The occurrence of Cushing's syndrome in a patient with chronic renal failure is extremely rare and poses significant diagnostic and therapeutic problems.

Adrenocorticotropic Hormone↗
PubMed1993

Serological characterisation of Neisseria gonorrhoeae by co-agglutination technique.

Antibiotic susceptibility pattern in cases of acute gonococcal urethritis, was studied by single disc diffusion technique and minimum inhibitory concentration (MIC) by agar dilution technique were determined for 5 antibiotics, viz penicillin, ampicillin, tetracycline, gentamicin and norfloxacin. All the penicillinase producing Neisseria gonorrhoeae (PPNG) and non-PPNG strains were sensitive to norfloxacin. 72% of the isolates belonged to serogroup WII/WIII by co-agglutination technique.

Adult↗
PubMed1993

Herpes simplex encephalitis: a diagnostic and therapeutic reapprisal.

Herpes Simplex Encephalitis (HSE) appears to be underdiagnosed in India, though viral encephalitides constitutes an important entity with significant morbidity. With an upsurge in AIDS, HSE may perhaps emerge as an important opportunistic infection in future. We discuss the clinical features and laboratory evaluation of nine cases of HSE seen in the last 12 years at our center. Diagnosis was established by brain biopsy in one, virological studies in six and at autopsy in three. Immunocytochemically viral antigens could be localized in 4 biopsied/autopsied brain tissue and in CSF cells on a cytospin preparation in one. This has facilitated rapid diagnosis in our cases. Virus isolation was successful in two. Three subjects were treated with acyclovir and all survived with variable morbidity. Four patients expired and none of them had received any specific antiviral drugs. Rapid diagnosis and early treatment with acyclovir has been highlighted.

Acyclovir↗
PubMed1993

High mortality in systemic fungal infections following renal transplantation in third-world countries.

Amongst 310 recipients of live related renal transplants, systemic fungal infections were observed in 19 patients (6.1%). These included cryptococcosis in eight (42%), candidiasis in seven (37%), mucormycosis in two (11%), aspergillosis in one (5.5%), and a mixed cryptococcal and Aspergillus infection in one patient (5.5%). Infections occurred within 12 months of transplantation in seven patients and after 13-37 months in the remaining patients. Prolonged fever not responding to antibiotics was the most common presentation. Central nervous system was involved in all patients with cryptococcosis, while Candida infection primarily involved the urinary tract. Both patients with mucormycosis exhibited signs and symptoms of florid rhinocerebral disease and a rapid downhill course. Pulmonary manifestations were the most prominent features of patients with aspergillosis. Parenteral amphotericin B with or without 5-fluorocytosine was started in all, but three patients could receive the therapy only for 1-3 weeks. Three patients with cryptococcosis developed amphotericin-related complications and were changed to oral fluconazole. Seven patients recovered and 12 (63%) died. None of the patients had cytomegalovirus infection preceding the onset of fungal disease. The high frequency of fungal infections amongst our allograft recipients could not be ascribed to over immunosuppression, since 16 patients (84%) were only on maintenance doses of immunosuppressive drugs and in 13 (68.4%) graft function was normal at the time of diagnosis. The high frequency of fungal infections in our patients was most probably related to the poor hygienic and sanitary conditions which continue to be prevalent in the tropical environment of third-world countries. Delays in the diagnosis and late institution of therapy result in a high mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspergillosis↗
PubMed1993

Modulation of cardiac performance by amiloride and several selected derivatives of amiloride.

Amiloride and its derivatives (benzamil, dichlorobenzamil, 5-(N,N-dimethyl)-amiloride, 5-(N-ethyl-N-isopropyl)-amiloride, (N,N-hexamethylene)- amiloride and 5-(N-methyl-N-isobutyl)-amiloride) are commonly used as selective blockers of Na+/Ca++ exchange or Na+/H+ exchange. Very little information is currently available regarding their effects on cardiac performance. It was observed that addition of amiloride or any of the selected derivatives to the coronary perfusate of the right ventricular wall produced a potent depressive effect on peak developed tension and the rates of tension generation and dissipation. The concentrations at which this occurred are those that are commonly used in ischemia or hypoxia studies. Significantly, the depressive action of the drugs increased with the perfusion duration and never achieved a stable level. An initial, transient positive inotropic effect was observed with some of the drugs. If the drug concentration and perfusion time was limited, the effects were reversible. All of the drugs except amiloride produced extra systoles. The drugs were capable of blocking Ca++ transients in isolated cardiomyocytes but had little effect on intracellular pH. The drugs lengthened the action potential duration and decreased the action potential amplitude and upstroke velocity. Their effects on cardiac performance may involve a complex inhibition of Ca++ influx and K+ efflux in addition to a stimulation of a nonselective cation current. It is concluded that amiloride and its analogs have striking effects on cardiac performance which may be unrelated to their capacity to inhibit Na+/Ca++ or Na+/H+ exchange. In summary, the use of these drugs is not normally recommended in cell or tissue perfusion experiments because of their nonselectivity. However, if the drug concentration and perfusion time is controlled carefully, interpretable data may be obtained in some cases.

Action Potentials↗
PubMed1992

Crystal and molecular structure of the alternating dodecamer d(GCGTACGTACGC) in the A-DNA form: comparison with the isomorphous non-alternating dodecamer d(CCGTACGTACGG).

The crystal structure of the alternating dodecamer d(GCGTACGTACGC) (5'-GC) has been determined to a resolution of 2.55A using oscillation film data. The crystals belong to space group P6(1) 22, a = b = 46.2A, c = 71.5A with one strand in the asymmetric unit, and are isomorphous with a previously described non-alternating dodecamer, d(CCGTACGTACGG) (5'-CC). Refinement by X-PLOR/NUCLSQ gave a final R factor of 14.2% for 1089 observations. The molecule adopts the A-DNA form. The interchange of the terminal base pairs in the two dodecamers results in differences in the intermolecular contacts and may account for the differences in the bending. This dodecamer shows an axial deflection of 30 degrees, in the direction of the major groove compared to 20 degrees in 5'-CC and may be a consequence of additional contacts generated in 5'-GC by the interchange of end base pairs. The high helical axis deflection appreciably influences the local helical parameters. The molecule exhibits relatively high inclination angles, and has a narrow major groove. The helical parameters when described relative to the dyad-related hexamer halves of the molecule give more reasonable values. The crystal packing, local helical parameters, torsion angles, and hydration are described and also compared with the non-alternating 5'-CC dodecamer.

Amides↗
PubMed1992

Sodium benzoate in the treatment of acute hepatic encephalopathy: a double-blind randomized trial.

A prospective randomized double-blind study was conducted to evaluate the efficacy of sodium benzoate in the treatment of acute portal-systemic encephalopathy. Seventy-four consecutive patients with cirrhosis or surgical portasystemic anastomosis and hepatic encephalopathy of less than 7 days duration were randomized to receive lactulose (dose adjusted for 2 or 3 semiformed stools/day) or sodium benzoate (5 gm twice daily). Assessment of response included mental status, asterixis, arterial ammonia level, electroencephalogram and number-connection test. Each was given a score between 0 and 4+. A portal-systemic encephalopathy index was calculated with these scores. Visual, auditory and somatosensory evoked potentials and a battery of psychometric tests for intelligence and memory were also performed to assess improvement. Thirty-eight patients received sodium benzoate; 36 took lactulose. Thirty patients (80%) receiving sodium benzoate and 29 (81%) receiving lactulose recovered; the remaining patients died. Improvement in portal-systemic encephalopathy parameters occurred in both treatment groups and was similar (p greater than 0.1). Electroencephalogram and evoked potentials were not as helpful as mental status in assessing of recovery. Psychometric test scores remained abnormal after recovery of mental status (21 to 42 days) and were probably too sensitive for monitoring of these patients. The incidence of side effects was similar in the two treatment groups. The cost of lactulose for one course of therapy was 30 times that of sodium benzoate. We conclude that sodium benzoate is a safe and effective alternative to lactulose in the treatment of acute portasystemic encephalopathy.

Acute Disease↗
PubMed1992

Development of a transformation system for the thermophilic fungus Talaromyces sp. CL240 based on the use of phleomycin resistance as a dominant selectable marker.

A transformation system for the thermophilic cellulolytic fungus Talaromyces sp. CL240 has been developed, using the phleomycin resistance gene from Streptoalloteichus hindustanus (Sh ble) as a dominant selectable marker. The plasmids (pAN8-1 and pUT720) carrying the Sh ble gene under the control of the Aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase (gpd) promoter, allowed selection of phleomycin-resistant transformants. A new promoter sequence cloned from chromosomal DNA of Trichoderma reesei (pUT737) was also able to drive efficient expression of the Sh ble gene in Talaromyces sp. CL240, resulting in the selection of transformants that were highly resistant to phleomycin.

Drug Resistance, Microbial↗
PubMed1992

Ki-ras oncogene activation in preinvasive pancreatic cancer.

Activation of the Ki-ras oncogene by specific point mutations at codon 12 occurs at a remarkably high frequency in pancreatic ductal adenocarcinoma and is likely to be an important event in the pathogenesis of this cancer. To determine whether ras activation also occurs in noninvasive proliferative lesions of the pancreas, a series of cases of ductal papillary hyperplasia, intraductal papillary neoplasia, and intraduct extensions of ductal adenocarcinoma were examined for activating mutations of Ki-ras at codons 12, 13, and 61 using polymerase chain reaction amplification. Specific mutations at Ki-ras codon 12 were found in 5 of 6 cases (83%) of intraduct extensions of carcinomas and in 12 of 16 (75%) invasive carcinomas. In cases with both intraductal and invasive components, the same mutation was identified in each. No mutations were found in 5 intraductal papillary neoplasms and 9 cases of ductal papillary hyperplasia. The authors conclude that Ki-ras activation at codon 12 is important in the tumorigenesis of ductal adenocarcinoma of the pancreas but is not required in the pathogenesis of ductal papillary hyperplasia or intraductal papillary neoplasm.

Adult↗
PubMed1992

Climate and admissions for mania in the tropics.

Seasonality of admissions for mania has been commonly reported. Most reports are from temperature zones. We analyzed admissions for mania covering a 9 year period and looked for any seasonal trends using existing methods. No seasonal variation was found. The hospital lies in the tropical zone with a relatively constant climate. This may influence the seasonal pattern of relapses in affective disorder.

Adult↗
PubMed1992

Time dependent therapeutic effects of single electroconvulsive therapy (ECT) in endogenous depression.

The present study was addressed to test the hypothesis of time dependent effects of a single ECT in endogenous depression. In a randomized, prospective and double blind controlled comparison 12 patients received only one true modified ECT followed by five sham ECTs on alternate days. They responded as well as the control group of 12 patients who received six true ECTs on alternate days. The Hamilton Rating Scale for Depression and a global rating scale for depression were used to monitor therapeutic response. The therapeutic effects of ECT were time dependent developing during the second week of the study period.

Adult↗
PubMed1992

Sister-chromatid exchanges are increased in epileptics, but not by sodium valproate.

Sister-chromatid exchange (SCE) frequency has been studied from peripheral blood lymphocyte cultures of 21 patients with epilepsy on sodium valproate, 20 patients who had not started therapy (untreated) and 20 normal healthy controls. Treated and untreated patients with epilepsy were observed to have higher SCE frequencies (mean 9.05 and 9.82 respectively) than healthy controls (mean 4.8; P < 0.001). There was no significant difference in SCE frequency between treated and untreated patients. This suggests that the disease itself may be associated with an increased frequency of SCEs.

Adolescent↗
PubMed1992

Protein-peptide interactions as probed by tryptophan fluorescence: serum albumins and enkephalin metabolites.

Binding of Leu-enkephalin and the enkephalin metabolite, tyrosine-glycine-glycine (TGG), to bovine serum albumin (BSA) was studied as a model to investigate protein peptide interactions. TGG and Leu-enkephalin quench the tryptophyl fluorescence of BSA. Stern-Volmer quenching constants were typically in the range of 40 to 300 M-1, depending on the experimental conditions. The addition of Cu(II) or Ni(II) did not change the quenching constant, indicating that TGG does not compete for the metal binding sites on BSA. From fluorescence quenching studies with TGG, tyrosyl-glycine, tyrosine and glycyl-glycine, it was concluded that the presence of the tyrosine residue is required for the observed quenching. The phenolic group in tyrosine accounted for the quenching mechanism because phenol was efficient in quenching BSA fluorescence, whereas phenylalanine had no detectable effect. A large solvent isotope effect on the quenching constant of phenol and TGG with BSA strongly suggests an active role of the -OH functionality in the quenching mechanism.

Amino Acid Sequence↗
PubMed1992

Inoculation lupus vulgaris.

An 11-years-old girl with lupus vulgaris on the right buttock following inoculation is described. The diagnosis was formed by the history, morphological characteristics, Mantoux test, histopathology, and was supported by an affirmative response to short course intensive chemotherapy (6 months). This route of infection acquires special significance with the worldwide-spread of HIV infection.

BCG Vaccine↗