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Biomedical subjects

S Patel

Publications and source records attributed to S Patel.

At least 703 records · Page 39Linked to original sources
PubMed1985

Neuropeptide Y (NPY)-like immunoreactive amacrine cells in retinas of frog and goldfish.

The distribution of neuropeptide Y (NPY)-like immunoreactivity in rat, rabbit, chick, frog and goldfish retinas was investigated by immunohistochemistry. Positive results were observed only in the frog and goldfish retinas. NPY immunoreactivity was associated with a small population of amacrine cell bodies in the inner nuclear layer and cell processes in the inner plexiform layer of both retinas. In the frog retina, three distinct layers containing immunoreactivity were observed in the inner plexiform layer. In contrast, the immunoreactivity in the same area of the goldfish retina was more or less separated into two layers. Convincing evidence could not be found for the co-existence of NPY-like material with other putative transmitter-like substances in the two retinas. Radioimmunoassay revealed the presence of small amounts of NPY-like immunoreactivity in the rabbit retina; the goldfish and frog retinas contained significantly more immunoreactive material. High performance liquid chromatography of the immunoreactive material in frog and goldfish retinas showed each retina containing different molecular forms of NPY-like proteins, neither of which resembled porcine NPY or PYY. The endogenous NPY-like material of the frog retina can be released by potassium depolarisation in a calcium-dependent way. In view of all these data an NPY-like protein must now be considered a potential retinal transmitter.

Animals↗
PubMed1985

A lesioning and 2-deoxyglucose study of the hyperactivity produced by an intra-accumbens dopamine agonist.

Lesioning and 2-deoxyglucose (2-DG) autoradiographic studies were applied to the hyperactivity induced in rats by intra-accumbens treatment with the dopamine agonist 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydro-naphthalene (ADTN). Lesions made in substantia innominata and rostro-ventral globus pallidus both attenuated the hyperactivity although no consistent changes in 2-DG uptake were recorded in these areas. Compared to normal rats, hyperactive rats showed greatly increased glucose utilization in the subthalamic nucleus and lateral habenula. Lesioning the subthalamic nucleus greatly reduced the hyperactivity, whereas a lateral habenula lesion was ineffective. Hyperactivity was associated with a discrete, bilateral area of increased 2-DG uptake in the reticular formation which corresponded to the description of the deep mesencephalic nucleus (DMN). Lesions made in the DMN greatly attenuated the hyperactivity response. The DMN may be a locomotor region in the rat.

Animals↗
PubMed1985

Sponge 'sentinel' of heavy metals.

The possibility of monitoring siliceous sponges as an ideal bioindicator of 17 trace metals and halogens was investigated. Of the two species of Demosponge from the Indian coastal waters receiving stable and radioactive nuclides (54Mn, 63Ni, 65Zn, 60Co, 75Se, 113Sn, 90Sr, 131I, 137Cs), Spirastrella cuspidifera was found to accumulate Cd, Cr, and Sn in the range of 15-2000 micrograms g-1 dry tissue, some 5-7 orders of magnitude higher than in the ambient waters. Prostylyssa foetida, from the same microecological niche, was found to be totally free of these three metal ions. The bioaccumulation of Ni was also significantly higher in S. cuspidifera (400-2250 micrograms g-1) than in P. foetida (7-15 micrograms g-1). The former species was also found to be an ideal sentinel for detecting levels of Co, Zn, and Ti; levels of Cu, Mn, Pb Fe and Sr were higher in P. foetida, but those of the halogens I and Br were practically identical in both species. Furthermore, bioaccumulation of metal ions was found to be a function of sponge tissue itself, rather than that of either obligate or facultative symbiont microflora. In view of the high degree of species specificity which sponges exhibit while accumulating many trace metal ions, a 'sponge watch programme' is proposed on a global scale for monitoring the health of coastal ecosystems against a variety of potentially toxic pollutants.

Animals↗
PubMed1985

A defect in cholesterol esterification in Niemann-Pick disease (type C) patients.

The demonstration of a defect of cholesterol esterification in a mutant strain of BALB/c mice with an attendant reduction of sphingomyelinase activity [Pentchev, P. G., Boothe, A. D., Kruth, H.S., Weintroub, H., Stivers, J. & Brady, R. O. (1984) J. Biol. Chem. 259, 5784-5791] prompted us to examine the capacity of cultured human Niemann-Pick fibroblasts to esterify exogenously derived cholesterol. Cholesterol was supplied to cell cultures in the form of native or chemically modified, positively charged low density lipoprotein or as non-lipoprotein cholesterol. Cholesterol esterification was not impaired in cell cultures derived from patients with type A or B Niemann-Pick disease. However, esterification of exogenously administered cholesterol was deficient in 20 type C Niemann-Pick cell lines that were available for testing. Fluorescence histochemical staining of unesterified cholesterol in type C cells suggested that these cells were able to internalize and lysosomally process lipoprotein cholesterol. Acyl-CoA:cholesterol acyltransferase activity did not appear deficient in type C cell extracts. The error in cholesterol esterification may provide an opportunity for probing the molecular lesion in this disorder and may afford a useful and reliable means for establishing diagnosis.

Cholesterol↗
PubMed1985

Effects of fluorescein on tear breakup time and on tear thinning time.

A simple, noninvasive method of in vivo precorneal tear film stability analysis is described. The method involves observing the first catoptric (first Purkinje) image. The effect of fluorescein on the results and the relation with standard tear breakup time (BUT) are presented.

Adult↗
PubMed1985

The biochemical and immunocytochemical characterisation of an antigen on the membrane of basal cells of the epidermis.

A murine monoclonal antibody, LICR-LON-23.10, which had been raised against a well-differentiated squamous cell carcinoma cell line (LICR-LON-HN5), recognises an antigen which is present on the membrane of basal cells of the epidermis. The tissue distribution of the antigen, as defined using immunohistochemical techniques, suggests that it is expressed preferentially on cells which are adjacent to a basement membrane. In squamous cell carcinomas, the antigen is expressed uniformly on undifferentiated cells, but in areas of keratinisation, the antigen is absent. The antigen recognised by the antibody was characterised as being a pair of glycoproteins with molecular masses of 120 and 135 daltons. The antibody was used for flow-cytometric analyses of epidermal keratinocyte preparations. Together with other basal cell markers, this antibody may be useful in the characterisation of the epidermal basal cell population as well as in broadening our understanding of the interaction between epithelial cell populations and their relationship with basement-membrane components.

Animals↗
PubMed1985

Protein synthesis and secretion by the human endometrium and decidua during early pregnancy.

To investigate the role of the endometrium in sustaining early pregnancy, specimens of endometrium from early pregnancy were incubated in vitro with radiolabelled amino acids, and protein synthesis and secretion were studied by subsequent fluorographic analysis of one-and two-dimensional polyacrylamide gels. Seventeen secreted endometrial proteins (EP) were identified. Changes were demonstrated in the rate of synthesis and/or secretion of a number of these proteins during early pregnancy. Two proteins, EP 14 and EP 15, are the principal secretory proteins of pregnancy endometrium. EP 14 (subunit mol. wt 32 000) is associated with decidualized endometrium and its rate of synthesis/secretion increases during early pregnancy. EP 15 (subunit mol. wt 28 000) is also synthesized and secreted by the secretory endometrium during the menstrual cycle, and during early pregnancy, but its secretion declines to undetectable levels by week 15-16. These proteins may provide useful markers of endometrial function and differentiation during the menstrual cycle and pregnancy.

Cytosol↗
PubMed1985

Reading attainment and physical development after whooping cough.

Anthropometric measurements were made on 360 primary school children with a history of whooping cough and on 711 controls. Altogether 245 (68%) cases and 469 (66%) controls had taken tests of reading attainment and a smaller number had taken tests of intelligence. No significant differences were found between cases and controls in any of the anthropometric measurements nor in reading age or intelligence quotient after controlling for social class and parental smoking. Whooping cough is, in general, unlikely to cause subsequent deficiency in physical or mental development.

Adolescent↗
PubMed1985

Immunochemical detection and characterization of pregnancy-associated endometrial alpha 1- and alpha 2-globulins secreted by human endometrium and decidua.

Antisera raised against the soluble antigens of the endometrium of early pregnancy detected two antigenic proteins of alpha 1 and alpha 2 mobility in extracts of this tissue and were termed antigens A and B. Neither antigen was detected in pregnancy sera or extracts of proliferative endometrium, but antigen B was detected in extracts of secretory endometrium and both were present in amniotic fluid and medium from in-vitro incubations of pregnancy endometrium. Fractionation of radiolabelled medium on ion-exchange chromatography demonstrated that antigens A and B co-eluted with the proteins from which EP14 and EP15 were derived and which were the major secretory polypeptides of pregnancy endometrium in vitro. Further biochemical purification revealed that EP14 (Mr 32 000) was derived from a protein of native molecular weight 36 000 which existed in two forms, whereas EP15 (Mr 28 000) was derived from a dimeric glycoprotein of native molecular weight 56 000. Immunochemical studies demonstrated that antigens A and B are identical to these two secretory proteins and have been termed pregnancy-associated endometrial alpha 1- and alpha 2-globulins (alpha 1- and alpha 2-PEG).

Alpha-Globulins↗
PubMed1985

In vitro stimulation of macrophages by quadrol [N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine].

Mouse peritoneal macrophages, when exposed to Quadrol [N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine] in vitro, show a dose dependent enhanced spreading over a four-hour period. In vitro Quadrol induced phagocytosis of polystyrene beads was found to be time and concentration dependent. The rate and extent of the enhancement of phagocytosis was comparable to that observed for lipopolysaccharide and tuftsin.

Animals↗
PubMed1985

Acute cerebral revascularization.

Fifteen patients evaluated for acute cerebral ischemia underwent acute cerebral revascularization between March, 1979, and May, 1983. Clinical presentation included crescendo transient ischemic attacks (TIA's) in eight cases, progressing neurological dysfunction in three cases, and completed nonfluctuating deficits in four cases. Nine patients received intravenous heparin but did not improve neurologically. The patients with crescendo TIA's were operated on within 4 hours of their last event; those with progressing deficits were operated on while the deficit was developing, and those with established deficits were operated on 4, 6, 9, and 12 hours, respectively, after the event began. The clinical picture for 10 patients had resolved within 10 hours after surgery. One patient with crescendo TIA's, two with progressing deficits, and two with established deficits had postoperative residual deficits, of which three were mild and two severe. One patient, who had a saphenous vein graft to the middle cerebral artery, developed an intracerebral hematoma. In this prospective noncontrolled nonrandomized study, acute cerebral revascularization was performed safely, had limited risks, and offered the potential to help some patients. Further controlled randomized studies are indicated.

Adult↗
PubMed1985

Inhibition by metoprolol of the antihypertensive effect of aspirin in young rats.

A group of 21-day-old, spontaneous hypertensive rats (SHR) received either aspirin (75-100 mg/kg), metoprolol (1.0-1.5 mg/kg) or both in their drinking water for 56 days. Controls received plain water. Groups of normotensive Wistar-Kyoto rats (WKY) received the same drug treatment as did the SHR. Blood pressure, heart rate and body weight were determined weekly, and water consumption was monitored on a daily basis. Renal prostaglandin (PG) activities were determined in a separate group of rats at 7 and at 56 days on each protocol. Blood pressures in the SHRs remained in the range of the WKY during 56 days of treatment with aspirin or metoprolol, but increased to hypertensive levels after exposure to plain water. Blood pressures in the WKY receiving aspirin or metoprolol were also lower than those receiving plain water, but the antihypertensive effect was somewhat slower in onset. The antihypertensive effects of aspirin and of metoprolol were lost in the SHR but not in the WKY when both drugs were given simultaneously in the drinking water. In comparison to rats receiving plain water, renal PG activity (PGF1 alpha and PGF2 alpha) was lower in rats receiving aspirin, metoprolol or both together. The mechanism for the antihypertensive effect of aspirin in the young SHR may be related to a decline in renal PG content, or to the release of other hormones controlling water and electrolyte balance. Reports that the cyclooxygenase inhibitors, such as aspirin, can block the antihypertensive effect of the beta adrenoceptor antagonists is confirmed in chronic studies using the SHR model.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1985

Nutritional assessment in patients with chronic gastrointestinal symptoms: comparison of functional and organic disorders.

We assessed the nutritional status of 119 patients with chronic gastrointestinal symptoms due to organic disorders (inflammatory bowel disease, IBD; peptic ulcer, PU; malabsorption syndrome, M; and malignant gastrointestinal tumours, T), by standard anthropometry and marker proteins (albumin; retinol-binding protein, RBP; and thyroxine-binding prealbumin, TBPA). We also studied 31 patients with irritable bowel syndrome (IBS) and 75 age-matched healthy controls (C). Compared with healthy controls, patients with organic bowel disease had significant abnormality of two or more anthropometric measurements (P less than 0.05). Plasma albumin was reduced in patients with IBD, M and T (P less than 0.001), but RBP and TBPA measurements were lower in all patient categories (P less than 0.01) including IBS. Stepwise discriminant analysis of the patient data alone, using three to six parameters, correctly separated 65 per cent PU patients, 66 per cent IBD and M, 72 per cent IBS and 88 per cent patients with T from other disease categories. We conclude that patients with chronic gastrointestinal symptoms often have some nutritional disturbances and that simple anthropometric and protein measurements might help us to distinguish patients with functional bowel disease from those with organic bowel disease.

Adolescent↗