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Biomedical subjects

S Chandra

Publications and source records attributed to S Chandra.

At least 235 records · Page 13Linked to original sources
PubMed1986

Nonspecific jejunitis--a challenging problem in children.

An acute enteric infection with the pathological feature of a severe necrotising jejunitis is an uncommon condition which mainly affects young people. It is characterized by severe abdominal pain of acute onset, copious bilious vomiting, and foul smelling loose stools containing blood. Exploration revealed varying degree of ischemic changes in the small bowel (mainly the upper jejunum) ranging from mucosal ulceration to frank gangrene of the bowel. The exact etiology is not known; the condition may be due to toxins produced by gram-negative bacilli or due to a localized allergic reaction. The disease had a progressive but self-limiting course. Mortality is around 40% and considerable morbidity continuing for 2-3 wk. Presentation bears similarity to Darmbrand of Germany, Pig-bel of New Guinea, and ischemic enteritis of Thailand.

Adolescent↗
PubMed1985

Imaging elemental distribution and ion transport in cultured cells with ion microscopy.

Both elemental distribution and ion transport in cultured cells have been imaged by ion microscopy. Morphological and chemical information was obtained with a spatial resolution of approximately 0.5 micron for sodium, potassium, calcium, and magnesium in freeze-fixed, cryofractured, and freeze-dried normal rat kidney cells and Chinese hamster ovary cells. Ion transport was successfully demonstrated by imaging Na+-K+ fluxes after the inhibition of Na+- and K+ -dependent adenosine triphosphatase with ouabain. This method allows measurements of elemental (isotopic) distribution to be related to cell morphology, thereby providing the means for studying ion distribution and ion transport under different physiological, pathological, and toxicological conditions in cell culture systems.

Animals↗
PubMed1985

The effect on photohaemolysis of variation in the structure of the porphyrin photosensitizer.

A comparison of the photosensitizing ability of a variety of porphyrins for photohaemolysis gives the following order of activity: protoporphyrin greater than deuteroporphyrin, mesoporphyrin, haematoporphyrin dimethyl ester much greater than haematoporphyrin diacetate, haematoporphyrin greater than haematoporphyrin monoacetate, coproporphyrin III, haematoporphyrin derivative, coproporphyrin III tetramethyl ester greater than uroporphyrin I, meso-tetra-(N-methyl-4-pyridinium)porphyrin tetratoluene-p-sulphonate, meso-tetra-(p-carboxyphenyl)porphyrin, protoporphyrin dimethyl ester, meso-tetra-(p-hydroxy-sulphonylphenyl)porphyrin tetrasodium salt, uroporphyrin III, deuteroporphyrin-3,8-disulphonic acid and protohaemin. The results for the metal-free porphyrins are rationalized in terms of solubility and partition properties, and a model is proposed for the incorporation of amphipathic porphyrins into the membrane lipid bilayer. Experiments with erythrocytes from patients with erythropoeitic protoporphyria and with normal erythrocytes to which porphyrin was added in a deuterium oxide medium do not lead to an increase in the rate of photohaemolysis. A possible explanation for this somewhat surprising observation is outlined.

Deuterium↗
PubMed1985

Chorioretinal and choriovitreal neovascularization after photocoagulation for proliferative diabetic retinopathy. A clinicopathologic correlation.

A patient with proliferative diabetic retinopathy was treated by panretinal and focal photocoagulation. Later, he developed one area of clinically diagnosed chorioretinal and choriovitreal neovascularization (CNV), neovascular glaucoma, and a blind painful eye necessitating enucleation. Clinicopathologic correlations of this eye including fundus photography, fluorescein angiography, light and electron microscopy are reported. Histopathologic examination revealed three areas of CNV, suggesting that some CNV may go undetected clinically also in other cases and thus may occur more frequently than evident from the literature. Our CNV occurred at sites of focal treatment. Retreatment of one area was unsuccessful. Choriovitreal neovascularization passed through discontinuities of Bruch's membrane into the retina and showed fenestrae of the endothelial cells. Endothelial fenestrae may account for the profuse fluorescein leakage seen clinically in CNV.

Adult↗
PubMed1984

Antibody affinity and immune complexes after immunization with tetanus toxoid in protein-energy malnutrition.

Protein-energy malnutrition reduced the affinity of antibody to tetanus toxoid, particularly after primary immunization. The effect on antibody affinity was more marked in patients with hypoproteinemia than in those with marasmus. Hemagglutinating antibody levels were comparable in undernourished and well-nourished groups. Circulating immune complexes were detected in eight of 21 children with protein-energy malnutrition and in one of the controls. Differences in antibody affinity in malnutrition may be an important determinant of altered host resistance and of complications of disease in nutritional deficiency.

Antibody Affinity↗
PubMed1984

Distribution of calcium during interphase and mitosis as observed by ion microscopy.

The ion microscope, based on secondary ion mass spectrometry, has been used to demonstrate the distribution of calcium in the root tip cells of two plant species, Allium cepa and Vicia faba. Interphase nuclei showed higher intensities of calcium than cytoplasm, while nucleoli exhibited higher calcium intensities than the rest of the nucleoplasm. The chromosomes showed high intensities of calcium at all stages of mitosis. Calcium was also detected in the cell plate and phragmoplast region of dividing cells. It appears that during prophase calcium concentrates in the condensing chromosomes, and during telophase it is transferred to nucleoli. These observations suggest that chromosomes may serve as a reservoir of calcium during mitosis.

Calcium↗
PubMed1983

Poland's syndrome.

Explore the source record for details and available documents.

Abnormalities, Multiple↗