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Dive into the research topics where Jyotsna Chakraborty is active.

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Featured researches published by Jyotsna Chakraborty.


Journal of Ultrastructure Research | 1966

Anaphase structure in mitotic cells typified by spindle elongation

L.E. Roth; H.J. Wilson; Jyotsna Chakraborty

Cells that are typified by anaphase spindle elongation have been chosen from five species and examined by electron microscopy. Filament morphology including diameter of individual filaments is constant throughout metaphase and anaphase within the limitations of the method employed. Filaments have been observed in the interzone in numerous anaphase mitotic figures, although the number of filaments there is less than on the poleward sides of the chromosome plates. During late anaphase in these cells, filaments disappear poleward first and then progressively toward the cleavage plane, and a disarrangement of filaments may be observed near their ends. Filaments are seen characteristically in parallel arrays, but definite perpendicular orientations have been observed in several cases. Golgi bodies and mitochondria may persist with largely unaltered morphology throughout division.


Urology | 1985

Quantitative evaluation of testicular biopsies from men with unilateral torsion of spermatic cord

Jyotsna Chakraborty; Amiya P. Sinha Hikim; Jagadish S. Jhunjhunwala

Torsion of the spermatic cord is not uncommon among young men. Various abnormalities in the histology of the contralateral testis have been reported due to unilateral torsion of the spermatic cord. We quantitatively estimated the germ cells from three groups of men: normal individual (Group I), men with unilateral torsion of short duration (Group II), and men with unilateral torsion of long duration or some other condition such as varicocele or intermittent torsion to the contralateral testis (Group III). No significant difference in the number of spermatogonia, spermatocytes, and spermatids of Groups I and II patients was observed. This observation indicates that there was no pre-existing morphophysiologic defect in the testis of Group II patients. Severe damage in the contralateral testis was noted in Group III patients. This indicates that if a damaged testis is retained in the body for a long time, the contralateral testis may be affected. Contralateral testis may also be affected by intermittent torsion or varicocele.


Urology | 1987

Unilateral torsion of spermatic cord in men: Effect on Leydig cell☆

Amiya P. Sinha Hikim; Jyotsna Chakraborty; Jagadish S. Jhunjhunwala

In our previous studies, we reported that short-term unilateral spermatic cord torsion had no adverse effect on the germ cells and the Sertoli cell in the contralateral testis of men. As an extension of our earlier investigations on the testicular pathophysiology in humans after unilateral spermatic cord torsion, the present study was undertaken to assess the Leydig cell function employing both fine structural and morphometric analysis in patients with short-term spermatic cord torsion. Bilateral testicular biopsy samples obtained from 4 men (15-19 years) with short-term unilateral torsion of the spermatic cord and from a control group of 6 men (15-40 years) were used in the present investigation. No appreciable difference in the Leydig morphology was noted between the biopsy samples from control and the contralateral testes. This was substantiated by morphometric analysis. The present study clearly indicates that patients with unilateral torsion of the spermatic cord may not essentially have bilateral testicular abnormalities, as suggested by the previous investigators. This report, thus lends further support to our earlier contention that alteration in microcirculation is quite likely the earliest and possibly the most significant contributor to the contralateral testicular damage in man after ipsilateral spermatic cord torsion.


Urological Research | 1985

Germ cell quantitation in human testicular biopsy.

A. P. Sinha Hikim; Jyotsna Chakraborty; Jagadish S. Jhunjhunwala

SummaryQuantitative analysis of human seminiferous epithelium was carried out using an improved method of glutaraldehyde and osmium fixation with plastic embedding. Part of each biopsy specimen was fixed in Bouins fixative and embedded in paraffin for comparison. Epon embedded tissue had very little artifactual damage compared with paraffin embedded tissue sections. The germ cell to Sertoli cell ratios were determined by counting the various germ cells per “unit” tubular area. Data obtained by this method reflect a remarkable stability of Sertoli cell number and germ cell-Sertoli cell ratios both between biopsies from different individuals and between biopsies from right and left testes from the same individual. Agreement between the present results and those of earlier studies based on paraffin embedded testicular specimens supports the validity of this method of germ cell quantitation of human testicular biopsy samples.


Archive | 1976

Basal lamina of human seminiferous tubule—Its role in material transport

Jyotsna Chakraborty; Leonard Nelson; Jagadish S. Jhunjhunwala; M. Young; K. Kropp

SummaryElectron microscopy of testicular biopsies obtained from two adult males with tunica vaginal hydrocele revealed some protrusions from the basal lamina to the germinal epithelium in the seminiferous tubule. The protrusions were of three types: some between the spermatogonia and Sertoli cells, some directly within the Sertoli cell cytoplasm and others inside the spermatogonia. The protrusions inside the spermatogonia were only 0.5 μm deep whereas the other types were from 1–11 μm deep. Occasionally some cut off portions of these protrusions were seen inside the ground cytoplasm of the Sertoli cell without an apparent connection with the original stalk. The matrix of the protrusions contained a homogenous component (composed of a fine filamentous element) and granular and membranous components. These components closely resemble the materials found in the basal lamina of the seminiferous tubule. It has been suggested that under mild pathological conditions, i.e., hydrocele, the junctions between the seminiferous tubule epithelium and the basal lamina become somewhat more flexible. As a result, the protrusions become longer and a passage might be formed to allow the flow of raw materials in or out of the seminiferous tubule.


Archives of Andrology | 1983

Effects of Stress on the Reproductive System of Male Rats and Mice

Angele McGrady; Jyotsna Chakraborty

Male rats were immobilized for 2 hr/day, 5 days a week, for varying periods of time (7-31 days) to assess the effects of stress on the reproductive system. Mice were immobilized for 25-38 days. The effectiveness of the stress was demonstrated by assessing the adrenal and body weight. Adrenal weights were significantly increased (p less than .05--t-test) compared to controls. Body weights were decreased compared to controls. No consistent change was noticed in the testicular weight and progressive motility of the spermatozoa drawn from the cauda epididymis and vas deferens. There were no deleterious effects of immobilization stress on the morphology of the differentiating germ cells, peritubular wall, and the interstitial tissues of the testis.


Archives of Andrology | 1979

Intranuclear Inclusion Bodies in Epithelial Cells of Human Vas Deferens

Jyotsna Chakraborty; Leonard Nelson; Jagadish S. Jhunjhunwala; M. Young; K. Kropp

Four different types of inclusion bodies were seen within the nucleus of the principal cells in segments of vas deferens from 40 fertile males: (1) electron-dense homogeneous bodies of various sizes (0.1--1.8 microns) and shapes, (2) granular bodies approximately 0.06--0.12 microns, (3) lipid inclusion bodies, and (4) less electron-dense, filamentous bodies. They were either membrane-bound or free within the nucleoplasm. Some membranous material was scattered within the nucleoplasm. The internal structure of nuclei containing these bodies differed from cell to cell. The nucleoplasm was composed either of dense granular elements or fine filamentous components. The aggregation and density of the ground nuclear material increased with increasing numbers of inclusion bodies. Very dense nuclei were in cells with typical features of degeneration. Frequently, extruded parts of cells or entire cells were seen within the lumen of the vas deferens.


Urological Research | 1986

Torsion of the spermatic cord--a long term study of the contralateral testis.

Jyotsna Chakraborty; A. P. Sinha Hikim; Jagadish S. Jhunjhunwala

SummaryThe object of the present investigation was to study the long-term effects of the unilateral torsion of the spermatic cord on the contralateral testis. Eighteen guinea pigs were divided into 3 groups. In group I of six animals, unilateral torsion of the spermatic cords was maintained until the time of sacrifice. In group II of six animals, torsion of the spermatic cords was maintained for 8–12h, then the spermatic cords were untwisted and the animals were maintained until the day of sacrifice. Group III six animals, received an injection of pentobarbital, which served as control. All animals were sacrificed after 16 months. Extensive light and electron microscopic studies were carried out. In the contralateral testes of the experimental group of animals, several degenerative changes were noted, which included excessive intraepithelial vacuolization, a loss of germ cells and the presence of tubules containing only Sertoli cells and a few spermatogonia. 10.6% and 19.5% seminiferous tubules were damaged in the contralateral testes of torsion maintained and the torsion reversed groups of animals, respectively in comparison to 3.1% tubular damage (indicated only by occassional presence of intraepithelial vacuoles and necrotic germ cells), in the control testis. It was concluded that long-term effect of unilateral torsion of the spermatic cord is permanent and irreversible in nature.


Urological Research | 1986

Effects of experimental torsion of the spermatic cord on Leydig cell function in the guinea pig testis: An ultrastructural stereological analysis

A. P. Sinha Hikim; Jyotsna Chakraborty; Jagadish S. Jhunjhunwala

SummaryAn ultrastructural stereological analysis of Leydig cells of the guinea pig testis was carried out following surgically induced testicular torsion. Morphometric analyses of the Leydig cells of the experimental group of animals revealed an increase in the nucelar and mitochondrial volume and a decrease in the lipid volume, in comparison to those in the Leydig cells of the control group of animals. We believe that these changes in the Leydig cells of the experimental group of animals are indicative of cellular hypertrophy. The possible mechanisms of the Leydig cell hypertrophy in the guinea pig testis following the induction of spermatic cord torsion are discussed.


Cells Tissues Organs | 1985

Effect of Experimental Torsion of the Spermatic Cord on Sustentacular Cells in the Guinea-Pig Testis

Jyotsna Chakraborty; A.P. Sinha Hikim; Jagadish S. Jhunjhunwala

Torsion of the spermatic cord is not an extremely rare occurrence among prepubertal and adolescent boys. Although it is known that torsion of the spermatic cord may lead to germ cell degeneration in the affected as well as in the contralateral testis, nothing is known regarding the response of sustentacular cells to this condition. During the present investigation, we studied the effect of experimental torsion on the sustentacular cells of guinea pig testes. Light-microscopic examination revealed that, although all types of germ cells, except a few spermatogonia, were degenerated in the guinea pig testes with torsion, sustentacular cells did not degenerate. This observation was confirmed from the quantitation data which indicated that the number of these cells remained unchanged when compared to the control and/or the contralateral testis of the same animal with unilateral torsion. Therefore, sustentacular cells of the damaged testis from guinea pigs can be used as reference cells for germ cell quantitation. The striking ultrastructural change in the sustentacular cells of damaged testes was characterized by the presence of well-developed annulate lamellae, which was not reported before in any other rodent species. Lobulated nuclei, numerous tight junctional complexes and lysosomes were other characteristic features of the sustentacular cells of damaged testes.

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Jagadish S. Jhunjhunwala

University of Toledo Medical Center

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Leonard Nelson

University of Toledo Medical Center

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Amiya P. Sinha Hikim

Los Angeles Biomedical Research Institute

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K. Kropp

University of Toledo Medical Center

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M. Young

University of Toledo Medical Center

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D.K. Chattoraj

Saha Institute of Nuclear Physics

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P. Sadhukhan

Saha Institute of Nuclear Physics

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