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Biomedical subjects

S Patel

Publications and source records attributed to S Patel.

At least 685 records · Page 38Linked to original sources
PubMed1986

Focal injection of 2-amino-7-phosphonoheptanoic acid into prepiriform cortex protects against pilocarpine-induced limbic seizures in rats.

Intraperitoneal injection of pilocarpine (380 mg/kg) produces motor limbic seizures in rats. Focal injection into the prepiriform cortex (PC) of an N-methyl-D-aspartate receptor antagonist, 2-amino-7-phosphonoheptanoic acid (APH), 1-10 pmol, potently protects against these seizures and their pathological consequences. Sites similarly sensitive to the protective action of APH are found along a substantial part of the anterior-posterior extension of the piriform cortex. More caudal injection sites, located at the level of lateral septum are less sensitive. The anticonvulsant action of APH along the extent of the PC is localised in the vicinity of the injection site, as shown by autoradiography following focal injection of tritiated APH.

2-Amino-5-phosphonovalerate↗
PubMed1986

2-Amino-7-phosphonoheptanoic acid (2-APH) infusion into entopeduncular nucleus protects against limbic seizures in rats.

Motor limbic seizures occur following a systemic injection of pilocarpine (380 mg/kg) in rats. Focal injection of the selective N-methyl-D-aspartate receptor antagonist, (+/-)-2-amino-7-phosphonoheptanoic acid (2-APH, 5-20 pmol), bilaterally into the entopeduncular nucleus (EP) prior to pilocarine blocks these seizures. Muscimol (50 pmol), a potent gamma-aminobutyric acid receptor agonist, injected bilaterally into EP produces a similar protection against pilocarpine-induced seizures. Thus by blocking excitatory neurotransmission or facilitating inhibition within the EP, the severity of limbic seizures can be reduced.

2-Amino-5-phosphonovalerate↗
PubMed1986

The cholesterol storage disorder of the mutant BALB/c mouse. A primary genetic lesion closely linked to defective esterification of exogenously derived cholesterol and its relationship to human type C Niemann-Pick disease.

An inborn murine cholesterol storage disorder exists which is characterized by a lesion in intracellular cholesterol esterification not accounted for by any discernible abnormality in acyl-CoA: cholesterol acyltransferase (Pentchev, P.G., Boothe, A.D., Kruth, H.S., Weintroub, H., Stivers, J., and Brady, R.O. (1984) J. Biol. Chem. 259, 5784-5791). Current studies have shown that the level of esterification of nonlipoprotein-derived [3H]cholesterol in cultured fibroblasts from heterozygous mutant mice was intermediary between the level found in normal fibroblasts and the deficient level found in fibroblasts from homozygous mutant mice. Homozygous-affected fibroblasts took up and converted [3H]desmosterol to [3H]cholesterol at a normal rate indicating that the murine mutation does not compromise the transport of exogenous sterol to microsomes. In contrast to the defect in esterification of exogenously derived cholesterol, synthesis of cholesteryl ester from [3H]mevalonic acid and [3H]squalene was normal in affected fibroblasts as was the stimulation of cholesteryl ester synthesis from endogenous cholesterol induced by 25-hydroxycholesterol. In surveying a number of mutant cell lines from human metabolic disorders with phenotypic manifestations similar in part to the mutant cholesterol storage mouse, Niemann-Pick C fibroblasts displayed a similar defect in esterification of exogenously derived cholesterol.

Animals↗
PubMed1986

Specific detection of noradrenaline in the rat brain by using antibodies.

Noradrenaline (NA) was conjugated to different protein carriers with glutaraldehyde. During the catecholamine conjugate synthesis, precautions were taken in order to preserve the structure of NA. Anti-NA antibodies were raised in rabbits and tested using a modified enzyme-linked immunosorbent assay and immunocytochemistry. The most immunoreactive antigen was found to be the reduced NA conjugate. The octopamine conjugate was recognized by the NA antiserum 16 X less than the reduced NA conjugate. The other conjugates, dopamine, L-dihydroxyphenylalanine and adrenaline were poorly recognized by the anti-NA antibodies. A good correlation was found between results obtained using the in vitro enzyme-linked immunosorbent assay and immunocytochemistry.

Animals↗
PubMed1986

GABA neurones in retinas of different species and their postnatal development in situ and in culture in the rabbit retina.

The localisation of GABA immunoreactive neurones in retinas of a variety of animals was examined. Immunoreactivity was associated with specific populations of amacrine neurones in all species examined, viz. rat, rabbit, goldfish, frog, pigeon and guinea-pig. All species, with the exception of the frog, possessed immunoreactive perikarya in their retinal ganglion cell layers. These perikarya are probably displaced amacrine cells because GABA immunoreactivity was absent from the optic nerves and destruction of the rat optic nerve did not result in degeneration of these cells. GABA immunoreactivity was also associated with the outer plexiform layers of all the retinas studied; these processes are derived from GABA-positive horizontal cells in rat, rabbit, frog, pigeon and goldfish retinas, from bipolar-like cells in the frog, and probably from interplexiform cells in the guinea-pig retina. The development of GABA-positive neurones in the rabbit retina was also analysed. Immunoreactivity was clearly associated with subpopulations of amacrine and horizontal cells on the second postnatal day. The immunoreactivity at this stage is strong, and fairly well developed processes are apparent. The intensity of the immunoreactivity increases with development in the case of the amacrine cells. The immunoreactive neurones appear fully developed at about the 8th postnatal day, although the immunoreactivity in the inner plexiform layer becomes more dispersed as development proceeds. The immunoreactive horizontal cells become less apparent as development proceeds, but they can still be seen in the adult retina. The GABA immunoreactive cells in rabbit retinas can be maintained in culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Comparison of serotonin and 5-methoxytryptamine immunoreactivity in rat raphe nuclei.

We studied the immunoreactivity of 5-methoxytryptamine (MT) and 5-hydroxytryptamine (HT) in the raphe region of rats using specific polyclonal antibodies and the peroxidase/anti-peroxidase (PAP) technique. Overall, the patterns of the specific staining for these two antibodies were found to be the same in this region of the rat brain. The staining reaction was considerably less intense for MT than for HT. Specificity tests were performed using HT, MT and tryptamine (T) conjugates at concentrations of 5 X 10(-8) M for antibodies to HT and 2.5 X 10(-9) M for antibodies to MT. Although the distribution of HT-like and MT-like immunoreactivity broadly overlapped, the results obtained from adsorption-specificity tests confirmed the presence of specific MT staining in the rat raphe.

5-Methoxytryptamine↗
PubMed1986

Effects of 6-hydroxydopamine-induced lesions of the paraventricular nucleus, and of prazosin, on the corticosterone response to restraint in rats.

In rats, with bilateral lesions of the paraventricular nuclei induced by 6-hydroxydopamine, restraint stress failed to elevate levels of corticosterone in plasma, although the resting levels in lesioned animals were similar to those of control rats. Prazosin inhibited the plasma-corticosterone response to restraint in intact rats, at doses which did not by themselves influence resting hormone levels. These results suggest a positive role for noradrenaline, acting through alpha-adrenoceptors, on the stress-induced output of corticotrophin.

Adrenergic alpha-Antagonists↗
PubMed1986

Toewebs as a source of gram-negative bacilli.

The prevalence of Gram-negative bacilli on the toewebs was 8% in normal students, 24% in hospital outpatients with suspected Tinea pedis, 41% in industrial workers wearing protective clothing and 58% in coal miners. Prevalence was greatest in those exposed to wet working conditions. In miners, the presence of Gram-negative bacilli was related to symptoms of itching/soreness and cracking/fissuring, and was negatively related to malodour, but this latter trend was reversed in outpatients and in industrial workers. The feet are a source of many 'enteric' and 'environmental' bacilli and could contribute to infection elsewhere than in the toewebs themselves.

Acinetobacter↗
PubMed1986

Survival of mice with NC carcinoma is unchanged by drugs that are thought to inhibit thromboxane synthesis or increase prostacyclin formation.

Mice transplanted with NC carcinoma were treated with the thromboxane synthetase inhibitor dazmegrel (UK38485) or with nafazatrom (BAY G 6575), a compound that is reported to increase prostacyclin formation. Some experiments included the cytotoxic drugs methotrexate and melphalan. The tumours were excised under anaesthesia on day 14 or day 21 after transplantation, and weighed; some were extracted for prostanoids which were measured by radioimmunoassay. Mouse survival time was determined up to day 121, and cancer spread was determined by postmortem examination. The survival was increased by methotrexate and melphalan but not by the other drugs. Nafazatrom-treated mice tended to have lighter tumours. Although dazmegrel reduced the formation of thromboxane B2 during clotting of blood from normal mice, it did not affect the tumour yields of prostanoids. Nafazatrom had no effect on serum or tumour prostanoids. There were no obvious effects of the treatments on the recurrence of tumour in the excision scar, lung metastasis or spread to lymph nodes.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

The natural history of asthma in childhood.

The incidence and prognosis of childhood asthma and wheezing illness (AW) was studied using data obtained at ages 7, 11, and 16 from a national cohort of 8806 children born in 1958. By the age of 16, 24.7% were reported to have experienced at least one episode of AW. In 18.3% AW had started before the age of 8, but only 4.2% continued to have symptoms in later childhood. A further 3.6% began to have AW between the ages of 8 and 11, and 2.8% began between the ages of 12 and 16. Of those with AW at age 7, 28.3% had symptoms at 11 and 16.5% at 16; these proportions were about doubled if AW at 7 had been severe. The associations between natural history and a large number of perinatal, social, environmental, and medical factors were examined. Those which predicted the onset of AW after the age of 7 were: male sex of child; mother aged 15-19 at child's birth; history of pneumonia, whooping cough, throat or ear infections or tonsillectomy; eczema, allergic rhinitis; and periodic vomiting or abdominal pain.

Adolescent↗
PubMed1986

Electrocardiograph voltage in fit young men.

Several criteria exist for the diagnosis for left ventricular hypertrophy as shown by high voltage on the electrocardiograph. This study of 200 healthy young recruits to the Royal Artillery with normal blood pressure and normal left ventricular wall thickness as measured by echocardiography [corrected] shows that no matter which criteria are used the false positive rate is approximately 25%. High voltage is a normal phenomenon in young men and its use as a predictor of left ventricular hypertrophy is likely to be misleading in this age group.

Adolescent↗
PubMed1986

Umbilical blood flow velocity waveforms in different maternal positions and with epidural analgesia.

Umbilical blood flow velocity waves were measured in the fetuses of healthy parturients in early active labor to assess the influence of different maternal positions (N = 16) and of epidural analgesia (N = 16). The ratio of systolic peak to diastolic trough (S/D) of the umbilical blood flow velocity wave is reflective of vascular resistance distal to the point of measurement on the fetal side of the placenta. Umbilical blood flow velocity wave S/D ratios were significantly higher in the supine than in either lateral position indicating that umbilical artery vascular resistance is increased when the mother lies supine. After epidural blockade, the S/D ratios were unchanged in three and lowered to varying degrees in 13 parturients indicating that this method of pain relief beneficially affects umbilical artery vascular resistance.

Anesthesia, Epidural↗
PubMed1985

Monoclonal antibodies recognizing epitopes carried on both glycolipids and glycoproteins of the human milk fat globule membrane.

The molecules of the human milk fat globule membrane (MFGM) which bind four murine monoclonal antibodies (LICR LON M3, M8, M18 and M24) raised against the human MFGM have been identified. By using 'Western' blotting [Burnette (1981) Anal. Biochem. 112, 195-203] it was shown that each antibody reacted with a different set of proteins. M3 and M24 were similar in their pattern of reaction with the membrane proteins, but were quite distinct from M8 and M18, which also differed from each other. Glycopeptides prepared from the MFGM by exhaustive Pronase digestion were able to inhibit partially the binding of M3 and M24, and prevent totally the binding of M8 and M18, to the MFGM in an enzyme-linked immunoabsorbent assay. Oligosaccharides obtained by the deproteination of human milk also completely inhibited the binding of M3, M18 and M24 to the MFGM. However, the binding of M8 was not inhibited by these saccharides, and therefore M8 may not be recognizing a simple carbohydrate determinant. By using an enzyme-linked assay, M8 and M18 were shown not to bind to MFGM glycolipid, whereas M3 and M24 did, and this was confirmed by overlaying thin layer chromatograms of MFGM lipids with these antibodies. Both M3 and M24 showed a similar complex pattern of reaction, binding to more than one glycolipid moiety. By these means all four antibodies have been shown to react with antigens which involve carbohydrate side chains carried on different proteins, and two were also shown to react with such determinants on glycolipids.

Antibodies, Monoclonal↗
PubMed1985

Can a sponge fractionate isotopes?

The study has unequivocally demonstrated that siliceous sponges Spirastrella cuspidifera and Prostylyssa foetida from the same microecological niche exhibit a high degree of species specificity, while accumulating a host of heavy metal ions (Ni, Cr, Cd, Sn, Ti, Mo, Zr). S. cuspidifera accumulated, in addition, 60Co and 63Ni, showing discrimination against other radionuclides, 137Cs and 131I, present in the ambient waters receiving controlled low level waste discharges from a B.W.R. nuclear power station. P. foetida, on the other hand, accumulated only 131I and showed discrimination against other radionuclides including 60Co, although the stable iodine concentrations in both the sponges were the same. The specific activity of 60Co (in becquerels per gram of 59Co) in S. cuspidifera and 131I (in becquerels per gram of 127I) in P. foetida were at least two orders of magnitude greater than in the ambient sea water. That of 63Ni (in becquerels per gram of 62Ni) in S. cuspidifera, on the other hand, was lower by two orders of magnitude than in either abiotic matrices from the same environment. Thus, not only did both the species show bioaccumulation of a specific element, but also preferential uptake of isotopes of the same element, though they were equally available for intake. Such differential uptake of isotopes can possibly be explained in terms of two quite different mechanisms operating, each applicable in a particular case. One is that the xenobiotic isotope enters the environment in a physicochemical form or as a complex different from that of its natural counterpart. If equilibration with the latter is slow, so that the organism acquires the xenobiotic in an unfamiliar chemical context, it may treat it as a chemically distinct entity so that its concentration factor differs from that of stable isotope, thus changing the specific activity. Alternatively, if the xenobiotic is present in the same chemical form as the stable isotope, the only way in which specific activities can be modified is by fractionation on the basis of mass of isotope. In view of the remarkable concentration factors observed for stable and radioactive isotopes of the same element and the specific activities reached, it is desirable that species of sponges, especially from the coastal and estuarine environments, be monitored to detect levels of pollution due to anthropogenic substances.

Animals↗
PubMed1985

Purification of a human plasma membrane glycoprotein from human red blood cells by affinity chromatography using a monoclonal antibody.

Using the monoclonal antibody LICR-LON-Fib75.1 coupled to Sepharose as an affinity chromatography column, a membrane glycoprotein with an apparent molecular weight of 18,000 on sodium dodecyl sulfate-polyacrylamide gels has been purified from human red blood cells. The purified protein contained 25% carbohydrate by weight, the predominant sugars being galactose, mannose, and glucosamine. Amino acid analysis indicated that the protein was relatively rich in aspartate, glutamate, valine, and leucine and had a low proline and methionine content. The molecule could be removed from intact red blood cells by trypsin and could be labeled with iodine by lactoperoxidase-catalyzed cell surface iodination of red blood cells. The protein could also be labeled using the lipidsoluble photoactivatable reagent 3-(trifluoromethyl)-3-(m-[125I]iodophenyl) diazirine) and partitioned into the lower phase of the phase-separable detergent Triton X-114. During size-exclusion chromatography in different detergents alterations were observed in the apparent molecular weight of the protein. These results suggest that this Fib75.1-binding protein is an external red blood cell membrane glycoprotein which is capable of binding detergent. Proteins with a similar molecular weight have also been isolated from two human tumor cell lines by immunoprecipitation with this monoclonal antibody.

Antibodies, Monoclonal↗
PubMed1985

Three synchronous multiorgan primary cancers. All stage I.

A patient who has three separate, synchronous, early (stage I) primary cancers of the right lung, right breast, and stomach and whose disease is simultaneously diagnosed and successfully treated sequentially within a single hospital admission is unique. While multiple primary malignant neoplasms are not uncommon, to our knowledge, there has been no report of triple stage I synchronous carcinomas in separate major organ systems. Age, immunodeficiency, somatotype, hereditary tendencies, hormonal and environmental factors, and previous therapy have been incriminated as etiologic factors. Accurate tissue diagnosis and tumor staging are mandatory. In patients with diagnosed cancer, pulmonary lesions should never be presumed metastatic. Individual tumors should be treated independently of other concomitant lesions, and each treatment approach should be curative in nature. Patients with proven multiple malignant neoplasms carry a higher risk of developing other primary neoplasms.

Aged↗