Search PubMed⌕ Search

Biomedical subjects

D N Singh

Publications and source records attributed to D N Singh.

At least 37 records · Page 2Linked to original sources
PubMed1983

Effects of chronic salt intake on the capillaries in the cerebral cortex of spontaneously hypertensive rats (SHRs): an ultrastructural study.

Fine structural changes of capillaries in spontaneously hypertensive rats (SHRs) under the influence of 1% NaCl were studied. In SHRs (control), 30 weeks and older, capillaries showed deformed lumina, hypertrophy of endothelial cells and matrical alterations of mitochondria. Deformed capillary lumina, fibrosis in upper stream vessels and swelling of astrocytic processes were observed in the saline-treated SHRs. The significance of these findings is discussed.

Animals↗
PubMed1981

Polymorphism in chromosome 4.

Chromosomal analyses were performed on 302 individuals, using QFQ banding techniques to determine the occurrence of heteromorphism of chromosome 4. Two type of heteromorphism were observed, one showing an intensely fluorescent band in the centromere region and the other an intensely fluorescent band in the proximal area of the short arm. No one individual possessed both type of heteromorphism. A higher frequency of chromosome 4 heteromorphism was found in patients with schizophrenia, mental retardation, hyperactivity, developmental delay and speech impediments than in normal individuals.

Adolescent↗
PubMed1981

The social worker's role in genetic counseling.

Genetic counseling is one major aspect of medical practice. It is a recent addition to the medical field that focuses on the etiology of genetic abnormalities.In the past the emphasis of genetic counseling was on determining the etiological diagnosis and on informing the patient of genetic facts and possible medical options. Areas such as the psychological adjustment and resource location for family support virtually were ignored by the majority of genetic counselors.For genetic counseling to be effective, the focus of counseling should be on psychological and social adjustment, with an emphasis on therapy, counseling, education, and liaison services for the patient and family. Social work can provide this expertise.

Congenital Abnormalities↗
PubMed1980

Reproductive performance in women with sex chromosome mosaicism.

Among chromosomal analyses performed in 23 couples with a history of 2 or more spontaneous abortions, 5 women had mosaicism of the sex chromosomes, 46,XX/47,XXX, but all the men had normal 46,XY chromosomal complements. A review of the literature revealed that 75% of the fetuses of mothers with sex chromosome mosaicism were abnormal. Fifty percent of theses pregnancies ended in abortion and one third of the infants exhibited a chromosomal or physical abnormality. The possible effect of sex chromosome mosaicism on outcome of pregnancy is emphasized.

Abortion, Habitual↗
PubMed1978

Inheritance of extra triradii of palmar interdigital areas II and IV.

Data obtained from 423 individuals were analyzed for mode of inheritance of extra triradii on palmar interdigital area II and IV separately, and in combination. It indicates that a single dominant allele A for extra triradius in the area II, and an allele D in the area IV, may be responsible for the presence of the patterns in the respective area, with 75 to 80 per cent penetrance. There are numbers of individuals in which extra triradii are present in both interdigital areas II and IV. The mode of inheritance has been estimated from the data obtained and was found to have co-dominant alleles A and D for the presence in their respective areas. Further analysis revealed the existence of three alleles. A and D for presence, and 0 for absence. The alleles A and D are co-dominant, if combined in the genotype AD, but either allele is dominant in heterozygous combination with 0.

Alleles↗
PubMed1977

Postnatal development of mitral cell perikaryon in the olfactory bulb of the rat. A light and ultrastructural study.

The differentiation of the mitral cell perikaryon in postnatal rat olfactory bulb was studied with the light and electron microscope. At birth the mitral cell was distinguishable and occupied a definitive position in the mitral cell layer. The cell contained a large oval nucleus surrounded by a thin rim of cytoplasm. Ribosomes, free and clustered, were scattered in the cell cytoplasm. Rough endoplasmic reticulum was relatively scarce. The Golgi complexes were made up of stacks of smooth-surfaced cisternae and associated vesicles. In certain cases the Golgi complexes projected into cellular processes. Mitochondria were present in all regions of the cytoplasm and contained well developed cristae. At the end of the first week, the mitral cell had developed significantly in size, and the cytoplasm contained well-developed rough endoplasmic reticulum. The Golgi complexes were made up of several stacks of smooth-surfaced cisternae with the association of vesicles and electron dense bodies. The apical dendrites of mitral cells at this period had increased significantly in length. Subsequently, during the second and third week, the rough endoplasmic reticulum and Golgi complexes became well developed. Associated with the Golgi complexes were electron dense lysosomal bodies. At three weeks and in older cells it was observed that dense lipofuschin granules increased significantly. It is suggested that the mitral cell matures and differentiates earlier than cells in the cerebral cortex.

Animals↗
PubMed1977

Diploid/tetraploid mosaicism in the offspring of a 46XX/47XXX mosaic mother.

A 10½-year-old boy with an IQ of 71, short stature, and isolated growth hormone deficiency was found to have diploid/tetraploid mosaicism. He was born to a 46xx/47xxx mosaic mother. The mother was found to be moderately mentally retarded but showed no other abnormalities. A review of literature pertinent to this case is presented.

Child↗
PubMed1976

Association of D/D translocations with fetal wastage and aneuploidy. A report of four families.

Four families are described with a t(13q14q) segregating. Two of them were identified through index cases with Down's syndrome; their karotypes revealed the unusual 46,XY, -13, -14, +t(13q14q), +21. The other two families were identified through a chromosomal study of parents with repeated spontaneous abortions. Analysis of data on 3 of these 4 families and on 7 other from the published reports showed no evidence of increased fetal wastage among 13/14 carriers. However, the risk of producing offspring with various types of aneuploidy may be greater among carriers than among persons with a normal chromosome pattern. Qualitative and quantitative differences in D/D translocations may account for the observed variation in clinical findings. These differences add to the problem of determining genetic risks from an analysis of grouped data.

Adult↗