Biomedical subjects
Publications and source records attributed to S Sharma.
Five cases of primary lymphoma of the brain are reported and the literature reviewed. The diverse clinical spectrum at presentation and variable response to therapy are few of its unique features. The literature is reviewed briefly and the importance of diagnosis at an early stage and prompt institution of therapy in form of radiation therapy and chemotherapy when indicated is stressed.
Primary melanoma of the meninges, a rare CNS tumor, is presented. Criteria for diagnosing a primary CNS melanoma are elucidated. Literature is reviewed in this context. The histogenesis of tumor, problem of occult primary melanoma and the role of CT scan and CSF cytology in early diagnosis have also been highlighted.
Thrombosis of a Bjork-Shiley valve in the mitral position was suspected clinically and confirmed by echocardiography and cine fluoroscopy. Streptokinase therapy followed by intravenous heparin infusion was given and the clot lysed successfully. The patient was asymptomatic upto two years of follow-up.
During the last 26 years, 21 patients with cirrhosis of the liver with severe cyanosis and gross clubbing simulating congenital cyanotic heart disease were subjected to cardiac catheterisation and angiography, splenography, liver function tests and liver biopsy. One patient had tetralogy of Fallot in addition, which was satisfactorily corrected. He continued to be intensely cyanosed and dyspnoeic despite adequate surgical correction of his cardiac defect as demonstrated on cardiac catheterisation and angiocardiography. Portupulmonary fistulas could not be demonstrated in any patient. The cyanosis and clubbing were secondary to right to left intrapulmonary shunting across multiple tiny pulmonary arteriovenous fistulas in all cases. In 16 cases selective pulmonary angiography revealed discrete arteriovenous fistulas. In 5 cases the angiogram did not reveal any convincing evidence of pulmonary arteriovenous fistulas. In 2 of these 5 cases peripheral vein contrast echocardiography, which seems to be a sensitive investigation, demonstrated right to left intrapulmonary shunting. Open lung biopsy in one case showed evidence of pulmonary arteriovenous fistulas.
Two cases of supravalvar aortic stenosis secondary to familial hypercholesterolaemia (type II A hyperlipoproteinaemia) are reported and the role of echocardiography in the diagnosis of this uncommon condition is discussed. The management of these patients is difficult and in one patient the serum cholesterol decreased substantially after treatment with gemfibrozil.
The in vitro antimicrobial efficacy of different extracts of seeds of Centratherum anthelminticum was studied by the filter paper disk method against several human pathogenic bacteria and fungi. Some of the extracts showed significant effect over tested bacteria and fungi.
Iniencephaly is a rare neural tube defect. We report a rare association of iniencephaly with cyclopia, probably the third such report in the literature.
The effect of epinephrine on ethanol metabolism was determined in isolated rat hepatocytes. Epinephrine (10 microM) enhanced an initial rapid rate of ethanol elimination observed in the first 5 min. Thereafter, between 5 and 90 min, the rate of ethanol elimination was slower and not affected by epinephrine. Epinephrine resulted in higher acetaldehyde concentrations at 2 min, but not thereafter. Acetaldehyde production in the presence and absence of epinephrine was inhibited by 4-methylpyrazole, by a low free extracellular calcium concentration, and by the alpha 1-adrenergic blocker prazosin. Ethanol alone and epinephrine alone increased oxygen consumption, but the effects were not additive. The ethanol-induced decreases in the cytosolic NAD-/NADH and NADP++NADPH ratios and in the mitochondrial NAD+/NADH ratio were delayed by the presence of epinephrine. An accelerated initial alcohol dehydrogenase activity sufficient to account for the rapid initial rate of ethanol elimination shown with epinephrine was demonstrated by coupling ethanol oxidation with lactaldehyde reduction, a system which increases the rate of dissociation of NADH from the enzyme and its oxidation back to NAD+. The findings in this study indicate that an increased reoxidation of NADH during ethanol oxidation by alcohol dehydrogenase is the basis for the rapid transient increase in ethanol elimination produced by epinephrine.
The effect of insulin-like growth factor I (IGF-I) on the activity of alcohol dehydrogenase was determined in primary hepatocyte culture from male rats. Continuous exposure of hepatocytes to IGF-I (30 nM) resulted in increases in alcohol dehydrogenase activity on Days 3-6 of culture. The increase in enzyme activity was preceded by increased alcohol dehydrogenase mRNA, indicating that the effect of IGF-I was at the pretranslational level. The effect of IGF-I was observed only in the presence of pharmacological concentrations of insulin in the media. Insulin alone had no effect on alcohol dehydrogenase activity. The permissive influence of insulin was correlated with the ability of insulin to maintain a steady high number of IGF-I binding receptors in the hepatocytes during culture. The response of alcohol dehydrogenase to IGF-I is similar to that previously demonstrated for growth hormone and suggests the possibility that the effect of growth hormone on this enzyme may be mediated by IGF-I.
We have previously shown that the steady state levels of transcripts encoded by an endogenous mouse mammary tumor virus (MMTV) increase during LPS-induced differentiation of both normal B lymphocytes and an inducible B cell lymphoma, CH12. A large body of evidence suggests that MMTV expression is primarily limited to mammary tissues and that expression in cell lines from nonmammary tissues is accompanied by viral amplification and alterations in the transcriptional control regions of the viral long terminal repeat. We have, therefore, carefully characterized MMTV expression in CH12 cells and in other cells of the B lineage in order to determine if the expression of MMTV transcripts in differentiating B cells results from the "abnormal" transcriptional regulation seen in other nonmammary tissue. In this manuscript, we present evidence that MMTV transcripts are expressed in a variety of cells of the B lineage and that the levels of constitutive expression vary among the different cells. On the other hand, T cell lymphomas lacking amplified MMTV do not contain proviral transcripts, suggesting that MMTV transcription may be preferentially expressed in B lymphocytes. We demonstrate that MMTV transcripts are up-regulated during cytokine-mediated as well as LPS-mediated differentiation, and that most, if not all, expression is due to the activity of a single proviral gene, Mtv-9, in CH12 cells. Furthermore, the expression of MMTV transcripts in CH12 cells neither requires nor is accompanied by amplification of the provirus. Sequence analysis demonstrates that the U3 region of the expressed Mtv-9 long terminal repeat contains neither deletions nor insertions, and the well-characterized enhancer and promoter sites in the glucocorticoid response element which are known to be involved in transcriptional regulation of MMTV in mammary tissues have not been disrupted. These data suggest that the Mtv-9 locus behaves as a normal somatic gene which is differentially regulated during B cell development and differentiation. Unlike the events which lead to MMTV expression in other nonmammary tissues, B cells may express transcription factor(s) which are capable of inducing expression of endogenous MMTV proviral genes during the natural course of differentiation. Analysis of the mechanisms which control the expression of this gene should be useful in characterizing the molecular events which govern B cell differentiation.
Explore the source record for details and available documents.
Nine cases of Acanthamoeba keratitis not associated with contact lens wear were diagnosed between July 1987 and August 1989. Patients were treated with topical neomycin-polymyxin B-bacitracin (Neosporin) drops alone or in combination with either miconazole nitrate or ketoconazole drops. At the time of data collection four patients were available for follow-up for an average of 4 months; however, four patients were unavailable for follow-up and one is still undergoing treatment. In four patients corneal infiltrates cleared completely with topical medication (Neosporin, two patients; Neosporin plus miconazole, two patients). Simple laboratory methods were found to be adequate for the diagnosis of Acanthamoeba keratitis. Therapy with Neosporin drops can result in resolution of corneal infiltrates due to Acanthamoeba species.
Explore the source record for details and available documents.
B cells from systemic lupus erythematosus (SLE) patients have been shown to be hyperactive as measured by proliferation and immunoglobulin production. We find that B cells from 6 of 13 SLE patients, in the absence of prior activation, respond two to three times better to recombinant 12-kDa B cell growth factor (BCGF) than do normal or rheumatoid arthritis B cells (p less than 0.005). B cells from normally responsive SLE patients require an anti-mu antibody activation step to generate similar proliferative signal in response to r12-kDa-BCGF. There are no clinical or serological parameters that distinguish these hyperresponsive SLE patients from the normally responsive SLE patients. The combination of r12-kDa-BCGF and interleukin 4 (IL4) gives an enhanced response with both normal and SLE B cells. Transforming growth factor type beta (TGF-beta) suppresses the response to r12-kDa-BCGF in a dose-dependent fashion using B cells from both healthy donors and SLE patients. We conclude that peripheral blood B cells are in an activated state (as detected by response to 12-kDa-BCGF) in approximately 50% of SLE patients. These B cells respond normally to regulation by IL4 and TGF-beta. A therapeutic approach aimed at reducing the B cell hyperactivity in SLE would involve suppressing the effects of 12-kDa-BCGF and IL4 while at the same time enhancing the effects of TGF-beta.
In Drosophila the Abdominal-B (Abd-B) domain of the bithorax complex (BX-C) spans over 100 kb and is responsible for specifying the identities of adult abdominal segments five (A5) to nine (A9), inclusive, and correspondingly, neuromeres 10-14 of the embryonic central nervous system. The domain consists of a region coding for two proteins, ABD-BI (54 kd) and ABD-BII (36 kd) and cis-regulatory regions extending from infra-abdominal-5 (iab-5) to iab-9, inclusive. We have used a monoclonal anti-ABD-B antibody to infer that mutants in iab-8 eliminate the expression of ABD-BI in neuromeres 10-13, inclusive, and that mutants in iab-9 eliminate expression of ABD-BII in neuromere 14. ABD-B expression is also analyzed in homozygotes for (i) loss-of-function mutants involving the iab-5, iab-6 and iab-7 regions, (ii) gain-of-function mutants Miscadastral pigmentation (Mcp) and Superabdominal (Sab), and (iii) a trans-regulator, Polycomb (Pc). ABD-B expression along the antero-posterior axis is colinear with the chromosomal order of the cis-regulatory regions. The behavior of rearrangement-associated iab-6 and iab-7 mutants suggests that the enhancer-like region, iab-5, and possibly also iab-6, may be shared between the abd-A and Abd-B domains. Such sharing is proposed as a factor that tends to keep gene complexes intact during evolution.
A comparative study of the wild type A. nidulans and a mutant strain aco-T69 (lacking conidia and cleistothecia) revealed the better production of beta-1,4-glucosidase in the former. The relative distribution of the enzyme levels in various morphological structures viz. somatic hyphae, spores and cleistothecia also showed a variation. Highest specific activity was found in the cleistothecial extracts. The electrophoretic analysis of the wild type strain demonstrated the presence of three isoenzymes of beta-1,4-glucosidase i.e. beta-GLU I, beta-GLU II and beta-GLU III, the number of which varies from one to three during the growth of the organism. The parallel study of the mutant strain showed complete absence of beta-GLU II. All three forms were present in the somatic hyphae and cleistothecial extracts while spore extracts depicted the absence of beta-GLU III in the wild type.
The clinicopathological features of 12 cases of primary lymphoma of the stomach are reviewed, and the efficacy of various treatment modalities is evaluated. The presenting symptomatology and the radiological signs were found to be similar to those of gastric carcinoma. Gastroscopy and computed tomography (CT) proved to be effective diagnostic and staging tools. There were two patients of stage I, seven patients of stage II, and three patients of stage IV. Multimodal therapy involving judiciously combined surgery, radiation therapy, and chemotherapy produced early complete remission in all the nine patients with localized disease, and all of them are disease-free at a minimum follow-up period of 12 months. These results are irrespective of whether surgery formed part of the treatment regimen. The relevant literature is reviewed, and the present status of the efficacy of nonsurgical therapy is evaluated.
Very few cases of malignant Sertoli cell tumour of the testis are reported in the literature. The average age at discovery of this tumour is 39 years. Malignant Sertoli cell tumour of the testis in a child is presented, the fourth case reported in the literature. We present our case to increase awareness of this tumour in this age group, to point out the capability of Sertoli cell tumours to metastasize, and to document the remarkable initial response to combination chemotherapy, a hitherto unreported feature.