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Biomedical subjects

V Misra

Publications and source records attributed to V Misra.

At least 55 records · Page 3Linked to original sources
PubMed1998

Fine-needle aspiration biopsy of colonic masses.

Between 1989 and 1996, fine-needle aspiration biopsy was performed in 22 patients with palpable colonic masses. In all of these patients colonoscopic examination was either not possible or could not be carried out successfully. The results of aspiration biopsy were confirmed by surgery and histopathological examination of the tissue. Aspiration biopsy correctly diagnosed all except one case. It identified all cases of colonic cancer. One patient with colonic tuberculosis was also diagnosed correctly. However, in another patient with colonic tuberculosis, aspiration biopsy showed only nonspecific changes in the form of inflammatory and epithelial cells. There were no false-positive results or complications from the procedure. It is concluded that fine-needle aspiration biopsy is a simple, rapid, and accurate method of diagnosing palpable colonic masses in patients in whom a colonoscopy is not possible or cannot be performed satisfactorily.

Adenocarcinoma↗
PubMed1998

Transfection of COS-1 cells with DT-diaphorase cDNA: role of a base change at position 609.

DT-diaphorase, a homodimeric flavoenzyme, can provide for a defence mechanism against carcinogenesis mediated by dietary or environmental quinones as well as bioactivate quinone-containing chemotherapeutic drugs. Human cell lines and strains have been identified with very low or undetectable enzymatic activity and a C to T transition at nucleotide 609 of the DT-diaphorase cDNA. This single base change is predicted to result in a proline to serine change in amino acid 187. Human cells homozygous for this base transition fail to exhibit Western blot reactivity for DT-diaphorase, suggesting that this substitution results in protein instability. To directly test whether this base change affects DT-diaphorase enzymatic activity and/or protein stability in vivo, mammalian expression vectors containing DT-diaphorase cDNA with or without the nucleotide 609 base transition were transiently transfected in COS-1 cells. Co-transfection with a human growth hormone expression vector allowed normalization for transfection efficiency. COS-1 transfectants expressing the C to T base change displayed at least a tenfold reduction in DT-diaphorase activity (P < 0.001) and a two- to threefold reduction in protein levels compared with wild-type transfectants. These results are the first to detect the presence of DT-diaphorase protein coded for by the 609 base transition in mammalian cells and confirm its predicted reduced enzymatic activity.

Animals↗
PubMed1998

Malignancy is the most common cause of gastric outlet obstruction even in a developing country.

BACKGROUND AND STUDY AIMS: It has recently been reported that in developed countries gastric outlet obstruction now predicts gastric malignancy. The aim of this study was to find out if this is the case in a developing country like India. PATIENTS AND METHODS: Seventy-four patients with gastric outlet obstruction underwent upper gastrointestinal endoscopy and biopsy specimens were obtained from any suspicious looking lesions or from the most distal point at which the endoscope could be positioned. RESULTS: In 56 patients (76%) the cause of the gastric outlet obstruction was malignant. On clinical and endoscopic appearance three patients were wrongly diagnosed as having malignancy when the cause, on endoscopic biopsy, was benign (tuberculosis n = 2, and immunoproliferative small intestinal disease n = 1). Twelve of the 18 patients with benign gastric outlet obstruction were managed conservatively with drugs and endoscopic balloon dilatation. CONCLUSION: Even in a developing country like India, malignancy is the commonest cause of gastric outlet obstruction and endoscopic biopsy specimens should be obtained in all patients with gastric outlet obstruction because the occasional benign lesions can be managed conservatively.

Adenocarcinoma↗
PubMed1998

Thickened gastric mucosal capillary wall: a histological marker for portal hypertension.

To evaluate whether the diameter or thickness of the wall of mucosal capillaries in the stomach could be a useful histological marker of portal hypertension, gastric mucosal biopsies were taken from the fundus and antrum of 73 patients with cirrhosis of the liver and 64 healthy volunteers. The mean +/- SD diameter of mucosal capillaries in the fundus of patients was not significantly different from that in the control group (59.4 +/- 16.8 microns vs 53.5 +/- 16.5 microns, respectively; P = NS). However, the mean +/- SD diameter of the antral mucosal capillaries was significantly greater in patients compared to controls (61.3 +/- 18.1 microns vs 47.6 +/- 12.7 microns, respectively; P < 0.001). The mean +/- SD thickness of the fundal and antral capillary wall in the patients group (6.8 +/- 2.4 microns and 7.2 +/- 2.4 microns, respectively) was significantly greater than that in the control group (3.5 +/- 1.5 microns and 3.3 +/- 1.5 microns, respectively) (P < 0.001 for each). The overall diagnostic accuracy of antral mucosal capillary diameter to diagnose portal hypertension was 50%, while that of thickened fundal and antral mucosal capillary wall was 84% and 85%, respectively. It is concluded that the gastric mucosal capillary walls are thicker in patients with portal hypertension and that this is a more reliable histological marker of portal hypertension than dilated gastric mucosal capillaries.

Adult↗
PubMed1998

AgNORs in benign, borderline and transitional cell neoplasms of the urinary bladder.

Argyrophilic nucleolar organizer regions (AgNORs) were studied in 106 tissue samples from the urinary bladder (6 normal transitional epithelium, 5 cystitis, 12 hyperplastic, 14 dysplastic lesions, 12 carcinoma in situ, 4 transitional cell carcinoma grade 0, 12 grade I, 15 grade II and 12 grade III) to evaluate their role in differentiating benign, borderline and malignant lesions. The NOR counts presented a rising scale from normal (2.21), inflammatory (3.93 for both cystitis and hyperplasia), dysplastic (4.16), carcinoma in situ (5.08) to malignant lesions (5.28 grade I, 6.59 grade II and 8.37 grade III). It was concluded that AgNORs do not have a diagnostic role in these lesions, but that they can act as a reliable adjunct to existing parameters in the early detection of tumour recurrence and grading of malignant neoplasms.

Carcinoma in Situ↗
PubMed1998

The herpesvirus transactivator VP16 mimics a human basic domain leucine zipper protein, luman, in its interaction with HCF.

In human cells infected with herpes simplex virus (HSV), viral gene expression is initiated by the virion protein VP16. VP16 does not bind DNA directly but forms a multiprotein complex on the viral immediate-early gene promoters with two cellular proteins: the POU domain protein Oct-1 and host cell factor (HCF; also called C1, VCAF, and CFF). Despite its apparent role in stabilizing the VP16-induced transcription complex, the natural biological role of HCF is unclear. Only recently HCF has been implicated in control of the cell cycle. To determine the role of HCF in cells and answer why HSV has evolved an HCF-dependent mechanism for the initiation of the lytic cycle, we identified the first human ligand for HCF (R. Lu et al., Mol. Cell. Biol. 17:5117-5126, 1997). This protein, Luman, is a member of the CREB/ATF family of transcription factors that can activate transcription from promoters containing cyclic AMP response elements (CRE). Here we provide evidence that Luman and VP16 share two important structural features: an acidic activation domain and a common mechanism for binding HCF. We found that Luman, its homolog in Drosophila, dCREB-A (also known as BBF-2), and VP16 bind to HCF by a motif, (D/E)HXY(S/A), present in all three proteins. In addition, a mutation (P134S) in HCF that prevents VP16 binding also abolishes its binding to Luman and dCREB-A. We also show that while interaction with HCF is not required for the ability of Luman to activate transcription when tethered to the GAL4 promoter, it appears to be essential for Luman to activate transcription through CRE sites. These data suggest that the HCF-Luman interaction may represent a conserved mechanism for transcriptional regulation in metazoans, and HSV mimics this interaction with HCF to monitor the physiological state of the host cell.

Animals↗
PubMed1998

Oesophageal subepithelial fibrosis: an extension of oral submucosal fibrosis.

Fifty-five patients with oral submucosal fibrosis and an equal number of patients with no evidence of the disease were studied. All patients underwent upper gastrointestinal endoscopy and any abnormality was noted. Multiple oesophageal biopsies were obtained from the upper end of the oesophagus and from any endoscopically observed abnormality. The histological changes in the two groups were assessed blindly by an experienced histopathologist. Histological abnormalities were noted in the oesophageal mucosa in 2% of controls and 66% of patients with oral submucosal fibrosis (p < 0.0001). In the control group, acanthosis was seen in one patient, while in the patient group atrophy of the squamous epithelium was evident in 52%, hyperkeratosis in 52%, parakeratosis in 30%, dyskeratosis in 14%, acanthosis in 14%, and papillomatosis and mild dysplasia in 2% patients. Subepithelial collagenization was seen in 32 (64%) patients. The oesophageal abnormalities were seen more frequently in patients who had consumed Pan masala, Gutka, betel nut, tobacco or a combination of some or all of these, with or without betel leaf, for > or = 5 years compared to those consuming them for a shorter period of time (91% vs 46%, p < 0.001). It is concluded that oral submucosal fibrosis is not a disease confined to the oral cavity; the oesophagus may also be involved in about two-thirds of patients.

Adult↗
PubMed1998

Cavernous lymphangioma in the vulva.

The vulva is a rare site for cavernous lymphangioma. We report on a case of cavernous lymphangioma arising from the right labium majoris.

Adolescent↗
PubMed1998

Spider angiomas are not found in the retina of patients with cirrhosis.

To determine the prevalence of spider angiomata in patients with cirrhosis, the factors influencing them and whether or not they are present in the retina of patients with cirrhosis, 93 cirrhotics were studied. Cutaneous spider angioma were seen in 19 (20%) patients. All patients with spiders had at least one episode of variceal bleeding and had grade III or IV oesophageal varices. Spiders were seen more commonly in patients with alcoholic cirrhosis than in those with non-alcoholic cirrhosis (53.5% vs 6%, p < 0.001), in patients with Child's C cirrhosis than those with Child's A and B cirrhosis (67% vs 4%, p < 0.001). However, although spiders were seen more often in patients undergoing sclerotherapy than those not, the difference was statistically not significant (23% vs 19%, p = NS). Spiders had no association with presence or absence of portal hypertensive gastropathy or gastric varices. None of the patients showed any abnormality or presence of spiders in the retina. It is concluded that spider angiomas are seen more commonly in patients with alcoholic cirrhosis, those with more severe liver disease and patients having large oesophageal varices and they are not seen in the retina of patients with cirrhosis.

Adult↗
PubMed1998

A, B & H isoantigens in cervical lesions.

Expression of A, B and H isoantigens in cervical mucosa was demonstrated by specific red cell adherence test in 92 cervical lesions (40 chronic cervicitis, 12 dysplasia and 40 carcinoma cervix). Eighty percent cases of chronic cervicitis showed a moderate reaction. On the contrary, in carcinoma cervix, 75% cases were found to be SRCA negative. In dysplasia, the intensity of red blood cell adherence was found to be directly related to the degree of cellular differentiation. Study of A, B and H isoantigens might help in deciding the prognosis of dysplasia and/or early detection of malignancy.

ABO Blood-Group System↗
PubMed1998

Helicobacter pylori-induced lymphonodular hyperplasia: a new cause of gastric outlet obstruction.

A 30-year-old female was seen with symptoms and radiological evidence of gastric outlet obstruction. Endoscopic examination revealed findings suggestive of gastric outlet obstruction with nodularity of the antral mucosa leading to deformity of the pylorus. Endoscopic biopsies from the nodular antral mucosa showed presence of Helicobacter pylori-induced lymphonodular hyperplasia without evidence of mucosa-associated lymphoid tissue lymphoma. Anti-H. pylori therapy resulted in eradication of the H. pylori infection and the signs and symptoms of gastric outlet obstruction. The case demonstrates that H. pylori-induced lymphonodular hyperplasia can also cause gastric outlet obstruction. We believe this is the first such case to be reported.

Adult↗
PubMed1997

Helicobacter pylori in areas of intestinal metaplasia in gastric antral mucosa.

Colonization of areas of intestinal metaplasia by Helicobacter pylori is rare and there is only one report in the literature of this organism colonizing areas of intestinal metaplasia in the antral mucosa. We report two more cases where H. pylori were seen in the gastric pits with intestinal metaplastic changes in the antral biopsy specimens.

Adolescent↗
PubMed1997

Histomorphometric study of portal hypertensive enteropathy.

Histopathologic features of duodenal and jejunal mucosal biopsy specimens obtained from 58 patients with portal hypertension and 30 healthy volunteers were studied. Dilated mucosal vessels with thickened walls were seen in duodenal and jejunal biopsy specimens from 39 (67%) and 41 (71%) of the patients, respectively, compared with corresponding biopsy specimens from 8 (27%) and 6 (2%) of the control subjects. The difference between the two groups was statistically significant. Other important histologic features in the patient group included edema of the lamina propria, fibromuscular proliferation, a decreased villous/crypt ratio, and thickened muscularis mucosae. The mean +/- SD thickness of capillary wall and diameter were significantly more in the patient group compared with those in the control subjects. We conclude that thick-walled dilated vessels along with edema of the lamina propria, fibromuscular proliferation, a decreased villous/crypt ratio, and thickened muscularis mucosae form a characteristic picture of portal hypertensive enteropathy. These changes seem to be a part of the changes seen in the gastrointestinal tract of patients with portal hypertension without any meaningful clinical implication except the increased chance of occult gastrointestinal blood loss.

Adolescent↗
PubMed1997

Luman, a new member of the CREB/ATF family, binds to herpes simplex virus VP16-associated host cellular factor.

The human host cell factor (HCF) is expressed in a variety of adult and fetal tissues, and its gene is conserved in animals as diverse as mammals and insects. However, its only known function is to stabilize the herpes simplex virus virion transactivator VP16 in a complex with the cellular POU domain protein Oct-1 and cis-acting regulatory elements in promoters of immediate-early viral genes. To identify a cellular function for HCF, we used the yeast two-hybrid system to identify a cellular ligand for HCF. This protein, Luman, appears to be a cyclic AMP response element (CRE)-binding protein/activating transcription factor 1 protein of the basic leucine zipper superfamily. It binds CREs in vitro and activates CRE-containing promoters when transfected into COS7 cells. This activation of transcription was synergistically enhanced by the presence of CCAAT/enhancer-binding protein elements and inhibited by AP-1 elements in the promoter. In addition to a basic DNA binding domain, Luman possesses an unusually long leucine zipper and an acidic amino-terminal activation domain. These features in Luman are also present in what appear to be homologs in the mouse, Drosophila melanogaster, and Caenorhabditis elegans. Luman and VP16 appear to have similar mechanisms for binding HCF, as in vitro each competitively inhibited the binding of the other to HCF. In transfected cells, however, while VP16 strongly inhibited the ability of GAL-Luman to activate transcription from a GAL4 upstream activation sequence-containing promoter, Luman was unable to inhibit the activity of GAL-VP16. Luman appears to be a ubiquitous transcription factor, and its mRNA was detected in all human adult and fetal tissues examined. The possible role of HCF in regulating the function of this ubiquitous transcription factor is discussed.

Adult↗
PubMed1997

Argyrophilic nucleolar organizer regions in atypical adenomatous hyperplasias, prostatic intraepithelial neoplasias and prostatic neoplasms.

Sections from 104 cases of benign, preneoplastic and neoplastic lesions of the prostate were studied for argyrophilic nucleolar organizer regions (AgNORs). The mean NOR counts in normal controls (2.87) and benign prostatic hyperplasia with or without chronic prostatitis (4.90 and 3.84 NORs/nucleus, respectively) were found to be significantly less (p < 0.001) than that in prostatic intraepithelial neoplasia (PIN) and adenocarcinoma of the prostate (5.65 and 5.78 NORs/nucleus, respectively). The mean AgNOR count of a section with atypical adenomatous hyperplasia was significantly lower than that in PIN. No statistically significant difference was observed between AgNOR counts of high-grade PIN and well-differentiated adenocarcinoma (WDAC; 5.67 vs. 5.78 NORs/nucleus, respectively), however the difference between low-grade PIN and WDAC was statistically significant (5.46 vs. 5.78 NORs/nucleus, p < 0.005). The increase in NOR counts occurred concomitantly with the decrease in the degree of differentiation of adenocarcinoma. Thus, NOR was found to be a good adjuvant to the existing diagnostic parameters to pick up more cases at the stage of PIN when prognosis is better.

Adenocarcinoma↗