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Biomedical subjects

K D Shah

Publications and source records attributed to K D Shah.

At least 19 recordsLinked to original sources
PubMed1992

Expression of sialylated Lewis(x) antigen in chronic and neoplastic liver diseases.

Phenotypic expression of sialylated Lewis(x) antigen by means of the monoclonal antiserum SNH3 was studied in 87 livers, which included normal and steatotic livers and livers with chronic persistent and chronic active hepatitis, alcoholic hepatitis, allograft rejection, focal nodular hyperplasia, hepatocellular carcinoma, cholangiocarcinoma, metastatic carcinoma, cirrhosis of various causes (autoimmune, alcoholic, viral, drug induced, Wilson's disease, and primary biliary cirrhosis). The biotin-streptavidin-peroxidase method was used on formaldehyde-fixed, paraffin-embedded sections. Sialylated Lewis(x) antigen was not demonstrated in normal livers. Hepatocellular expression in a diffuse or perinodular honeycomb pattern was seen in cirrhosis, irrespective of cause. Sialylated Lewis(x) antigen was also observed in hepatocytes around metastatic carcinoma in the absence of inflammation, cirrhosis, or regeneration. Some bile ductules, most likely ductular hepatocytes, but not bile ducts, expressed sialylated Lewis(x) antigen. Sialylated Lewis(x) antigen was seen diffusely in fibrolamellar hepatocellular carcinoma, focally in other hepatocellular carcinomas, and either focally or diffusely in cholangiocarcinomas.

Chronic Disease↗
PubMed1991

Fetal fibronectin in cervical and vaginal secretions as a predictor of preterm delivery.

BACKGROUND: Preterm delivery is the leading cause of neonatal mortality in the United States, but efforts to address the problem are hampered by the inability to predict accurately which pregnancies are at risk. We postulated that damage to the fetal membranes may release fetal fibronectin into the cervix and vagina, giving rise to a biochemical marker for preterm delivery. METHODS: We measured fetal-fibronectin concentrations in cervical and vaginal secretions, amniotic fluid, and maternal plasma with a sensitive immunoassay using the monoclonal antibody FDC-6. Immunohistochemical studies were used to determine the distribution of fetal fibronectin in the placenta and amniochorionic membranes and to ascertain its cell of origin. RESULTS: Women with uncomplicated pregnancies (n = 163) who delivered at term rarely had cervicovaginal fetal-fibronectin concentrations above 0.05 micrograms per milliliter between 21 and 37 weeks of gestation (11 of 267 cervical samples [4 percent] and 9 of 267 vaginal samples [3 percent]. High levels of fetal fibronectin were detected in amniotic fluid and in the cervical or vaginal secretions of 93.8 percent of the women with preterm rupture of membranes (n = 65). Cervical or vaginal fetal fibronectin was also present in 50.4 percent of the women with preterm uterine contractions and intact membranes (n = 117), and its presence identified the women who delivered before term (n = 60) with a sensitivity of 81.7 percent and a specificity of 82.5 percent. In the placenta and membranes, fetal fibronectin was found at points of contact with the uterine wall. CONCLUSIONS: The presence of cervicovaginal fetal fibronectin in the second and third trimesters of pregnancy identifies a subgroup of women who are at high risk for preterm delivery. This phenomenon may reflect the separation of the chorion from the decidual layer of the uterus, with the release of intact or degraded chorionic components of the extracellular matrix into the cervical and vaginal secretions.

Amniotic Fluid↗
PubMed1990

CMV enteritis causing hemorrhage and obstruction in an infant with AIDS.

Serious gastrointestinal infections from cytomegalovirus (CMV) are often observed in immunosuppressed patients especially those with acquired immunodeficiency syndrome (AIDS). Hemorrhage and perforation have been frequent consequences. We present a case of CMV enteritis in an infant with AIDS who suffered massive hemorrhage and subsequent fatal small bowel obstruction from this condition. Gross findings at laparotomy were striking, diffuse, large yellowish plaques along the entire length of the small bowel. Each of these had a central ulceration. Each eventually caused a partial narrowing resulting in refractory small bowel obstruction. Biopsy of one of these lesions demonstrated many cells with typical cytomegalic inclusion bodies. This report illustrates a newly recognized type of CMV enteritis that can affect an infant and be readily recognized at laparotomy.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Development of intrahepatic bile ducts in humans. Possible role of laminin.

Laminin, a major extracellular matrix-attachment glycoprotein, may play an important role in the differentiation and migration of epithelial cells during normal development. Therefore, the morphogenesis of bile ducts in human liver of fetuses at sequential gestational ages, neonates, children, and adults was examined by single and double immunohistochemical staining for laminin and for cytokeratins. The latter served as a marker for developing and mature bile duct epithelial cells. A close association was observed between laminin deposition and the differentiating ductal plate cells at the epithelial-mesenchymal interface of portal tracts and during the subsequent migration of ductular structures into the center of portal tracts. Simultaneously, laminin disappeared from the margins of portal tracts, but scattered ductal plate-like structures with laminin remained demonstrable in neonates, children, and even adults. These observations were substantiated by semiquantitative evaluation of laminin at the periphery of portal tracts. Thus, clear evidence is provided that laminin accompanies bile duct epithelial cells during all successive stages of differentiation and migration during the development of the human hepatobiliary system. The persisting ductal plate cells may represent a common stem cell for proliferation of bile ductules and hepatocytes.

Adult↗
PubMed1990

Noninvasive and invasive evaluation of left bundle branch block (LBBB).

Nineteen patients with LBBB were studied by clinical, electrocardiographic (ECG), echocardiographic, electrophysiological and coronary angiographic examination. The commonest etiology of LBBB observed was idiopathic/degenerative in 10 (52.6%), followed by atherosclerotic coronary artery disease in 6 (31.5%) and hypertrophic cardiomyopathy, dilated cardiomyopathy and systemic hypertension in 1 case each (15.7%). In all patients with coronary artery disease (CAD), significant lesion of the left anterior descending artery was observed. On ECG, presence of Q in I, aVL, V5 or V6 was most helpful in predicting the presence of CAD while primary T-wave changes were least helpful. The degree of QRS axis was not helpful in predicting the presence as well as severity of CAD. Altered septal/regional wall motion abnormalities were commonly encountered on echocardiography and left ventriculography. Although infrahisian conduction delay was frequently observed and 11 (61.1%) had prolonged HV interval, in 2 of these there was additional suprahisian conduction delay. All patients with prolonged PR interval (more than or equal to 200 msec) or wide QRS duration (more than 140 msec) had infrahisian block with or without associated suprahisian block. Hence, hemodynamic evaluation, coronary angiographic studies and electrophysiological evaluation is essential in patients with LBBB.

Adult↗
PubMed1989

Application of a quick immunoenzymatic labeling as an adjunct to frozen-section diagnosis.

Immunoenzymatic labeling is not currently used in the frozen-section diagnosis of tumors, in view of the length of the procedure. The authors tested whether, without loss of specificity and sensitivity, the labeled avidin-biotin (LAB) method may be adequately shortened for use in frozen-section diagnosis. Cryostat sections of tumors of various types and different degrees of differentiation and a panel of monoclonal antibodies to various molecular weight cytokeratins, vimentin, and leukocyte common antigen was used. The entire LAB procedure was completed in less than 7 minutes. For comparison, all tumors were also stained by the conventional avidin-biotin complex (ABC) method, which required more than one and a half hours for completion. The pattern and intensity of specific staining for the two procedures was identical, and the background staining was minimal with the LAB method. In view of the short time required to obtain specific staining, the quick LAB method may be of great value for characterization of primary or metastatic tumors in frozen-section diagnosis.

Avidin↗
PubMed1989

Development of intrahepatic bile ducts in humans. Immunohistochemical study using monoclonal cytokeratin antibodies.

Cytokeratins (CKs) are major structural proteins of intermediate filaments of epithelia. Recent availability of monoclonal antibodies (MoAbs) against various CK polypeptides has made it possible to study their development during cellular differentiation. We analyzed the expression of CKs in the human liver during development. Twenty-four liver specimens were tested by the avidin-biotin complex immunohistochemical method by using three MoAbs against different CK polypeptides (CAM 5.2 against CKs 50, 43, and 39 kd; AE1 against acidic CKs 56.5, 50/50', 48, and 40 kd; and 34 beta E12 against CKs 58, 56.5, and 56 kd). Liver parenchymal cells in fetuses as early as 4 weeks of gestational age reacted with MoAbs CAM 5.2 and AE1, but the expression of AE1-positive CK polypeptides in hepatocytes disappeared by 24 weeks of gestational age. Small cells, presumably ductal plate cells, in direct contact with mesenchyme around the portal vein and along the branches of portal veins, showed strong staining with MoAbs CAM 5.2, AE1, and 34 beta E12, identical to that of bile ducts. In neonates, children, and even in adults, residual MoAbs CAM 5.2-,Ae1, and 34 beta E 12-positive cells were present around the branches of portal veins. These findings suggested that the CK profile of liver parenchymal cells changes during their differentiation into hepatocytes, whereas that of ductal plate cells and bile ducts remains unaltered with respect to the polypeptides tested here. Some ductal plate cells may persist in neonates, children, and even in adults.

Adult↗
PubMed1987

Comparison of cytokeratin expression in primary and metastatic carcinomas. Diagnostic application in surgical pathology.

Metastatic poorly differentiated carcinomas often represent diagnostic difficulties in surgical pathology. Therefore, the expression of cytokeratins of different molecular weights (54, 57, and 66 kd) were compared in paraffin sections of 37 primary carcinomas with their lymph node metastases by an avidin-biotin complex (ABC) method, using monoclonal antibodies. The epithelial tumors consisted of 16 squamous cell carcinomas (SCCs) and 17 adenocarcinomas with different degrees of differentiation (well, moderately, or poorly differentiated), a renal cell carcinoma, a hepatocellular carcinoma, a transitional cell carcinoma of the bladder, and a carcinoid tumor of the stomach. The primary and metastatic tumors showed the same cytokeratin profiles. All SCCs and their metastases were positive for 57-kd cytokeratin and negative for 54-kd cytokeratin. All adenocarcinomas and their metastases were positive for 54-kd cytokeratin and negative for 66-kd cytokeratin. The extent of reactions varied with the differentiation of the carcinomas, with well-differentiated tumors showing more diffuse staining. Cases of lymphoma, sarcoma, and melanoma were negative for the three types of cytokeratins. The results indicate that identification of different molecular weight cytokeratins may be used to distinguish poorly differentiated SCCs from poorly differentiated adenocarcinomas, even in metastatic tumors. In addition, demonstration of these cytokeratins is useful in substantiating presence and identity of small foci of metastases in lymph nodes.

Adenocarcinoma↗
PubMed1987

Immunohistochemical distinction of Paget's disease from Bowen's disease and superficial spreading melanoma with the use of monoclonal cytokeratin antibodies.

The differentiation of Paget's disease from Bowen's disease and Pagetoid superficial spreading melanoma may represent diagnostic difficulties. The special stains used in their differential diagnosis are nonspecific and not always sensitive. Therefore, the expression of cytokeratins of different molecular weights (54, 57, and 66 kilodaltons [kD]) was studied in 26 intraepithelial neoplasms in formalin-fixed paraffin-embedded tissues with the use of an avidin-biotin complex (ABC) method with monoclonal cytokeratin antibodies. These included 9 cases of Paget's disease, 11 cases of Bowen's disease, and 6 cases of Pagetoid superficial spreading melanoma. Paget cells from vulva and breast were always positive for 54-kD cytokeratin, variable for 57-kD cytokeratin, and negative for 66-kD cytokeratin. The neoplastic cells in all 11 cases of Bowen's disease were stained for 57-kD and 66-kD cytokeratins but not for 54-kD cytokeratin. The neoplastic cells in all cases of melanoma did not express any of the cytokeratins studied. The results indicate that antibodies to cytokeratins of different molecular weights may be used as a diagnostic tool in the distinction of Paget's disease from Bowen's disease and melanoma.

Antibodies, Monoclonal↗