PubMed Health⌕ Search

Biomedical subjects

S Ashraf

Publications and source records attributed to S Ashraf.

29 records · Page 2Linked to original sources
PubMed1997

Increase in immunoreactivity for endothelin-1 in blood vessels of rat liver metastases: experimental sarcoma and carcinoma.

Using electron immunocytochemistry, blood vessels in the normal rat liver and in 2 different animal models of liver metastases: (1) Hooded Lister rat with MC28 tumour, a sarcoma, and (2) nude rat with HT29 tumour, a carcinoma, were investigated for the presence of endothelin-1. In the normal livers, small subpopulations of vascular endothelial cells displayed discrete immunoreactivity for endothelin-1. In the livers with malignant tumours, there was a substantial increase in endothelin-1-immunoreactive endothelial cells in vessels located at the tumour periphery. In the controls, antibody to endothelin-1 also labelled sporadically some fibroblast/fibroblast-like cells associated with the blood vessels. In contrast, intense immunoreactivity for endothelin-1 was frequently associated with the tumour cells and/or fibroblast cells in both types of tumour examined.

Animals↗
PubMed1996

The absence of autonomic perivascular nerves in human colorectal liver metastases.

The peptidergic/aminergic innervation of normal liver and tumour blood vessels was investigated in order to determine vascular control with a view to improving the efficacy of hepatic arterial cytotoxic infusion in the treatment of colorectal liver metastases. Selected areas of liver metastases and macroscopically normal liver from resection specimens (n = 13) were studied using light microscope immunohistochemistry for the presence of protein gene product 9.5 (PGP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), substance P (SP) and tyrosine hydroxylase (TH). The ultrastructure of blood vessels supplying liver metastases and their perivascular innervation were also examined by transmission electron microscopy. In the normal liver, perivascular immunoreactive nerve fibres containing PGP, NPY and TH were observed around the interlobular blood vessels and along the sinusoids and the central vein of the hepatic lobule. The greatest density of immunoreactive nerve fibres was seen for PGP, followed (in decreasing order) by NPY and TH. VIP, SP and CGRP immunoreactivity was observed only in nerve bundles associated with the large interlobular blood vessels. In contrast, no perivascular immunoreactive nerves were observed in colorectal liver metastases. Electron microscopy confirmed the absence of perivascular nerves in liver metastases. In addition, it showed that the walls of these blood vessels were composed of a layer of endothelial cells surrounded by an incomplete or, very rarely in the periphery of the tumour, a complete, layer of synthetic phenotype of smooth muscle-like cells. These results imply that the blood vessels supplying liver metastases are bereft of normal neuronal regulation; whether there is a role for endothelial cell control of blood flow in these vessels is not yet known.

Adenocarcinoma↗
PubMed1996

Primary ocular relapse in acute lymphoblastic leukemia.

Relapse of acute lymphoblastic leukaemia (ALL) occurred in the anterior segment of four children. All cases had been treated according to the Medical Research Council's UK Acute Lymphoblastic Leukaemia trial protocol (UKALL) including 2 years of continuation chemotherapy. In three cases the diagnosis was confirmed by anterior chamber aspirate while in one case the diagnosis was presumed on clinical grounds alone. All four cases experienced isolated leukaemic relapse in the anterior segment within 2 months of stopping therapy. The months immediately following cessation of continuation chemotherapy as part of the UKALL regime appear to represent a 'high-risk' period for primary anterior segment relapse of ALL. Children with ALL presenting with uveitis should be regarded as having leukaemic relapse and anterior chamber taps with or without an iris biopsy should be considered to confirm this diagnosis. Early diagnosis and treatment of ocular leukaemic relapse is likely to give these children the best chance of ultimate cure.

Anterior Chamber↗
PubMed1996

Characterization of high-affinity protein D binding sites on the surface of rat epididymal spermatozoa.

125I-labeled protein D was shown to bind to whole rat epididymal sperm in a time-dependent, saturable, and reversible manner. Scatchard analysis indicates that there are 3.4 x 10(5) binding sites/sperm cell with a binding efficiency (Kd) of 2.3 x 10(-10) M. Binding of protein D to sperm reaches equilibrium by 95 min. and is reversible by 30 min. Specific binding of protein D to sperm pre-treated with a dilute trypsin solution is reduced significantly when compared with controls. Our findings establish that protein D-specific binding proteins displaying characteristics of a true receptor are present on the surface of rat epididymal sperm.

Animals↗
PubMed1995

Calbindin immunoreactivity of horizontal cells in the developing rabbit retina.

Horizontal cells are retinal interneurons that establish inhibitory feedback loops within the outer plexiform layer of the primary visual pathway. Most mammalian retinas contain two types of horizontal cells. A-type horizontal cells have neuritic branches that contact cone photoreceptors exclusively, while the B-type horizontal cells have dendritic branches that contact cones, in addition to axons that form synapses with rod photoreceptors. Immunoreactivity for calbindin, a calcium binding protein involved in calcium transport, was used as a marker for horizontal cells during post-natal development of the rabbit retina. On post-natal days 1, 3 and 5, calbindin immunoreactivity is limited to a single population of A-type horizontal cells. They appear as a monolayer of cells with broad tapering processes, establishing the proximal border of the nascent outer plexiform layer and forming a target for ingrowing cone photoreceptor terminals. The size and density of the cell bodies and the length of neuritic processes are essentially unchanged during this period, which corresponds to the time of peak expression of GABAergic markers in horizontal cells. Coincident with a decrease in GABAergic markers and the completion of cone-to-horizontal cell synaptogenesis by day 7, changes within the horizontal cell mosaic are detected morphometrically. A delayed phase of overall cell growth results in a 70% increase in average somal diameter (representing a 3.7-fold increase in spherical volume), a six-fold increase in mean neurite length and a decrease in cell density to one-third of that found in the newborn. We conclude that the process of terminal differentiation of horizontal cells is not complete until some time after the second post-natal week. Furthermore, the expression of GABAergic markers is associated primarily with early maturational events, whereas expression of calbindin is sustained throughout post-natal development, suggesting a prominent role for calcium dependent mechanisms at all development stages.

Animals↗
PubMed1993

Myocardial infarction in a young adult due to Kawasaki disease. A case report and review of the late cardiological sequelae of Kawasaki disease.

Although Kawasaki disease is generally self-limiting, 15-25% of children with Kawasaki disease may develop significant cardiovascular sequelae, presentation may occur acutely or late (death has been reported up to 14 years after the acute illness). The most common late complication is the persistence of coronary artery aneurysms, these may produce myocardial ischaemia and even myocardial infarction, valvular dysfunction has also been reported. However the occurrence of late abnormalities of myocardial function is controversial. We describe a 24-year-old man who presented with myocardial infarction as a result of coronary artery aneurysms caused by Kawasaki disease, he gave no recent or childhood history of prodromal illness compatible with Kawasaki disease. The diagnosis was confirmed at post mortem.

Adult↗
PubMed1990

Evaluation of nutritional status and its effects on morbidity and mortality of surgical patients.

Sixtynine patients (31 males and 38 females) above the age of 12 years undergoing surgery under general anaesthesia were selected for this study. Thirty percent males and 29% females were depleted, 55% and 37% males and females, respectively, were normal and 13% and 34% males and females, respectively, were obese as indicated by Body-mass index (BMI). Measurement of midarm-muscle-circumference (MAMC) indicated mild to moderate protein deficiency in 32% of the patients while triceps skinfold thickness (T.S.T) indicates mild to severe calorie deficiency in 68% males and 50% females. Dietary intake both pre and post operatively was unsatisfactory. Pre-operatively 26% of the females had Hb level below normal (less than 11 G%). Only 3-5% of the patients had protein and albumin level below normal (less than 3.5 G%). Post-operatively all the anthropometric measurements as well as serum protein and albumin levels decreased and BUN increased significantly indicating body catabolism. Post operative hospital stay was significantly more in undernourished patients.

Adolescent↗
PubMedDate not supplied

Carcinoma gall bladder presenting as hemobilia.

A 60-year-old man presented with recurrent bouts of melena, requiring multiple transfusions. Upper GI endoscopic evaluation demonstrated fresh bleeding from the ampulla of Vater. Ultrasonography and CT scan suggested a gall bladder mass without evidence of metastases. Laparotomy confirmed a mass confined to the lumen of the gall bladder. The patient underwent cholecystectomy. Histological examination showed papillary adenocarcinoma of the gall bladder extending up to the muscularis propria.

Adenocarcinoma, Papillary↗