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Dive into the research topics where G.K. Das is active.

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Featured researches published by G.K. Das.


Animal Reproduction Science | 2012

Expression of leptin and its receptor in corpus luteum during estrous cycle in buffalo (Bubalus bubalis)

Lalit Kumar; R.P. Panda; I. Hyder; V.P. Yadav; K.V.H. Sastry; G.T. Sharma; R.K. Mahapatra; Sadhan Bag; S.K. Bhure; G.K. Das; Abhijit Mitra; Mihir Sarkar

Leptin is supposed to play a crucial role in ovarian luteal dynamics. The present study was aimed to investigate the importance of leptin and its receptors in buffalo corpus luteum (CL) obtained from different stages of the estrous cycle. Real-time RT-PCR (qPCR), western blot and immunohistochemistry techniques were applied to investigate mRNA expression, protein expression and localization of examined factors. Additionally to assess the contribution of leptin in progesterone production the expression profiles of StAR, P450scc and HSD were also investigated. In general, we demonstrated presence of leptin and its receptors in buffalo CL during the estrous cycle. The mRNA levels of leptin and its receptors were significantly up regulated in (P<0.05) in all the stages and highest levels were observed in mid and late luteal stages consistent with in vivo luteinization of buffalo CL and declined coincidental to luteal regression. The expression of StAR, P450scc and HSD factors maintained low in early luteal phase, after that level of expression increased steadily to show a significant rise (P<0.05) in mid luteal phase followed by gradual decline in late luteal phase and regressed CL and this correlates well with the Ob and ObR receptor activity, verifying their key role in progesterone and other steroids production in functional CL. As revealed by immunohistochemistry, leptin protein was localized predominantly in large luteal cells however leptin receptor (Ob-R) was localized in large luteal cells as well as in endothelial cells. It can be concluded from our study that leptin via its autocrine/paracrine effects play a significant role in promoting angiogenesis, steroidogenesis and also acts as key survival factor in bubaline CL.


Animal Reproduction Science | 2011

Biochemical and hormonal composition of follicular cysts in water buffalo (Bubalus bubalis)

F.A. Khan; G.K. Das; Megha Pande; M.K. Pathak; M. Sarkar

The objective of this study was to examine the follicular fluid biochemical and hormonal changes associated with ovarian follicular cysts in buffalo. Follicular fluid was aspirated from eight cysts and eight preovulatory follicles, and subjected to biochemical and hormonal analyses. Cysts were characterized by a greater (P<0.01) concentration of nitric oxide and lesser concentrations of ascorbic acid and glucose than that of preovulatory follicles (P<0.01 and P<0.05, respectively). Furthermore, follicular cysts had greater concentrations of progesterone (P<0.001), triiodothyronine (T(3)) and cortisol (P<0.05) and lesser concentrations of insulin (P<0.001) than preovulatory follicles. The results indicate follicular cysts in buffalo have an altered biochemical and hormonal composition. The alterations include increases in nitric oxide, progesterone, cortisol and T(3) concentrations with a concurrent reduction in ascorbic acid, insulin and glucose concentrations. The study suggests that greater progesterone concentrations possibly inhibit the onset of LH surge resulting in formation of follicular cysts in buffalo. In addition, it implies the plausible role of intra-ovarian regulators such as nitric oxide, ascorbic acid and insulin in development of the condition.


Animal Reproduction Science | 2012

Alterations in follicular fluid estradiol, progesterone and insulin concentrations during ovarian acyclicity in water buffalo (Bubalus bubalis)

F.A. Khan; G.K. Das; Megha Pande; M. Sarkar; R.K. Mahapatra; Uma Shankar

Ovarian acyclicity is one of the most important causes of infertility in water buffalo. Recent studies have indicated alterations in the composition of follicular fluid during the condition. The aim of this study was to determine the changes in follicular fluid concentrations of estradiol, progesterone and insulin during ovarian acyclicity in water buffalo. Ovaries were collected from 50 acyclic and 95 cyclic (control) buffaloes and follicular fluid was aspirated from small (5.0-6.9 mm), medium (7.0-9.9 mm) and large (≥10.0 mm) sized follicles. Estradiol concentration was lower (P<0.0001) in acyclic (1.4 ± 0.09 ng/ml) than in cyclic (3.3 ± 0.18 ng/ml) buffaloes. Regardless of the ovarian cyclic status, there was an increase (P<0.01) in estradiol concentration with the increase in follicle size; the mean concentrations were 2.4 ± 0.16 ng/ml, 2.8 ± 0.29 ng/ml and 3.5 ± 0.41 ng/ml in small, medium and large follicles, respectively. A higher (P<0.001) progesterone concentration was recorded in acyclic (24.3 ± 2.61 ng/ml) compared to the cyclic (7.6 ± 0.79 ng/ml) group. Furthermore, acyclic buffaloes had a lower (P<0.05) concentration of insulin in the follicular fluid than that of cyclic buffaloes (15.2 ± 1.55 μIU/ml versus 25.9 ± 2.78 μIU/ml, respectively). In conclusion, acyclic buffaloes have lower concentrations of estradiol and insulin concurrent with higher concentrations of progesterone in the follicular fluid. These hormonal changes in the follicular microenvironment are possibly a manifestation of the disturbances in the normal follicular development leading to anovulation and anestrus in acyclic buffaloes.


Animal Reproduction Science | 2017

Partial deoxygenation of extender improves sperm quality, reduces lipid peroxidation and reactive oxygen species during cryopreservation of buffalo (Bubalus bubalis) semen

B Balamurugan; Srikanta Ghosh; Shabir Ahmad Lone; J. K. Prasad; G.K. Das; R. Katiyar; Abdul Rahman Mustapha; Ajay Kumar; Verma

The present study was designed to investigate the effect of partial deoxygenation of extender on sperm quality, lipid peroxidation (LPO) and reactive oxygen species (ROS) in buffalo (Bubalus bubalis) during cryopreservation of semen. Semen extender was prepared freshly and split into three sub-extenders [Extender I: control (non-deoxygenated), Extender II (partially deoxygenated by using LN2 flushing) and Extender III (partially deoxygenated mechanically by vacuum pump)]. Amounts of dissolved oxygen (DO) were determined in all the three extenders and also in post-thaw semen. Ejaculates with mass motility of  ≥3+ and individual progressive motility of 70% or greater were collected from Murrah buffalo bulls and utilized in the study. Each semen sample was divided into Groups I (diluted with Extender I), II (diluted with Extender II) and III (diluted Extender III) with a maximum of 60 × 106 sperm/mL. French mini straws (0.25 mL) were filled with the extended semen samples, sealed with polyvinyl alcohol powder, kept for 3 h at 5 °C for equilibration and then stored in an automatic programmable freezer until the temperature of straws reached -145 °C followed by plunging the straws into liquid nitrogen (-196 °C). Semen samples were evaluated at pre-freeze and post-thaw stages for various variables [sperm motility, live sperm count, acrosomal integrity, hypo-osmotic swelling (HOS) response, LPO and ROS concentrations]. The mean DO was less (P < 0.05) in Extender II as compared to I and III. The DO was less (P < 0.05) in Group II (semen extended with Extender II) as compared with III (semen extended with Extender III) and I (semen extended with Extender I). The percentages for sperm motility, viability and intact acrosomes (PIA) were greater (P < 0.05) in Groups II and III as compared to the control group at the pre-freeze stage, while at the post-thaw stage, percentages of sperm motility, viability, PIA and HOS response were greater (P < 0.05) in Group II as compared with the control group and Group III. Pre-freeze HOS response (%) was greater (P < 0.05) in Group II as compared with the control and Group III. At the pre-freeze stage, sperm LPO and ROS were less (P < 0.05) in Groups II and III as compared with the control and at post-thaw stage, spermatic LPO and ROS concentrations were less (P < 0.05) in Group II than in the control group and Group III. In conclusion, partial deoxygenation of extender improves sperm quality, reduces sperm LPO and ROS concentrations in buffalo during cryopreservation. Partial deoxygenation of the extender with LN2 flushing may be one of the ways for improving quality and fertility of frozen-thawed buffalo sperm.


Veterinary World | 2016

Effect of incubation on freezability of cholesterol-loaded cyclodextrin treated buffalo (Bubalus bubalis) spermatozoa

Shabir Ahmad Lone; J. K. Prasad; S. K. Ghosh; G.K. Das; B. Balamurugan; R. Katiyar; M. R. Verma

Aim: The aim of this study was to investigate the effect of incubation on freezability of cholesterol loaded cyclodextrin (CLC) treated buffalo spermatozoa. Materials and Methods: Semen samples with mass motility of 3+ and greater, collected from Murrah buffalo bulls were utilized. Immediately after collection, four equal groups of semen sample were made. Group I was kept as control and diluted with Tris upto concentration of 60×106 sperm/ml, where as Groups II, III, and IV were treated with CLC at 3 mg/120× 106 spermatozoa, incubated at 37°C for action of CLC for 10, 15 and 20 min, respectively, and diluted with tris upto concentration of 60×106 sperm/ml. All groups were subjected to equilibration and freezing. The evaluation of semen samples from all groups was carried out at fresh, pre-freeze and post-thaw stage for progressive motility, viability and hypo-osmotic swelling response (HOS response). Results: At the pre-freeze stage, significantly (p<0.05) higher percentage of progressive motility and viability was observed in treatment groups as compared to control with no significant difference among treatment groups. HOS response was significantly (p<0.05) higher in treatment groups as compared to control at pre-freeze stage. At post-thaw stage, significantly (p<0.05) higher percentage of progressive motility, viability and HOS response was recorded in Group II as compared to control and other treatment groups (III and IV). Group II retained significant post-thaw motility and viability at various post-thaw incubation periods. Conclusion: Incubation period of 10 min for CLC treated buffalo spermatozoa yielded significantly higher results in terms of freezability as compared to incubation for 15 and 20 min.


International Journal of Contemporary Pediatrics | 2018

Prognostic factors affecting outcome of hospitalised infants 1-6 months with severe acute malnutrition in North India

Lalit Kumar; G.K. Das; Ajay Gaur

Early infancy represents a period of transition from neonatal life to childhood during which there is rapid growth, neurological and immunologic development, and changes in the mode of feeding. Nutrition programs and surveys have traditionally excluded infants under 6 months of age because adequate nutrition is assumed to be ensured by breastfeeding. However, there is increasing recognition that malnutrition occurs before age 6 months and is associated with mortality. According to recent studies 4.7 million infants under 6 months of age worldwide are moderately wasted and 3.8 million are severely wasted.


Animal Reproduction Science | 2018

Reduction of dissolved oxygen in semen extender with nitrogen gassing reduces oxidative stress and improves post-thaw semen quality of bulls

Abhishek Kumar; J. K. Prasad; Abdul Rahman Mustapha; Beigh Yaqoob Amin; Omer Din; R. Katiyar; G.K. Das; N. Srivastava; Ajay Kumar; Med Ram Verma; Srikanta Ghosh

The objective of the present study was to investigate the effects of two different concentrations of dissolved oxygen (DO, 4 and 8) ppm in the extender on oxidative stress affecting plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), and deoxyribonucleic acid (DNA) damage of bull spermatozoa following cryopreservation. For the experiment, nitrogen (N2) gassing of the extender for varied time intervals yielded extender with DO concentration of 4 ppm and 8 ppm (Groups II and III, respectively). For the Control (Group I) without N2 gassing, a DO concentration of 11.7 ppm was recorded. Following sample selection, ejaculates were divided into three aliquots and were extended to have 80 × 106 spermatozoa/mL of extender in the three groups. Semen samples were evaluated for reactive oxygen species (ROS), lipid peroxidation (LPO), total antioxidant capacity (TAC) and superoxide dismutase (SOD) at the fresh, pre-freeze, and post-thaw stages. Evaluation of PMI, MMP, and DNA damage were conducted on frozen-thawed samples. There were greater (P < 0.05) increase in ROS and LPO and decrease in TAC concentrations in Group I than Groups II and III. Mean values of SOD at the post-thaw stage was greater (P < 0.05) in Group II than Group I. There was a similar trend in the PMI in Groups II and III; MMP and DNA integrity in Group II was greater compared with Group I. In conclusion, results indicate there was a beneficial effect of maintaining DO concentrations at 4 rather than of 8 or 11.7 ppm in extender for sustaining post-thaw semen quality.


International Journal of Contemporary Pediatrics | 2016

Comparison of pulse oximetry and colour: a better index of oxygenation in neonatal resuscitation

Akanksha Bansal; G.K. Das; Ravi Ambey

Background: Colour is an unreliable indicator of tissue oxygenation in the first few minutes of life. Little data is available about the progression of SpO 2 in the new-borns delivered by normal vaginal route and caesarean section. So this study was conducted. The objectives of this study were to compare the new-born’s colour and oxygen saturation readings as an index of oxygenation and to find a more reliable one, and to compare the oxygen saturation profiles of the new-borns delivered by normal vaginal route and caesarean section. Methods: This was a prospective observational study conducted over a period of one year in a tertiary care hospital on 500 newborns between 28-42 weeks, requiring routine care. Simultaneous assessment of colour and oxygen saturation readings was done at 30 second intervals after birth till 10 minutes of life . Results: No significant difference has been found in the median SpO 2 values of the new-borns requiring routine care that were pink and cyanosed since birth (p≥ 0.05). About 5.30 minutes required for most of the cyanosed new-borns to become pink (p≥ 0.05). Mean time±SD required for cyanosed new-born for getting pink was 1.96±1.33 minutes. Oxygen saturation rises slowly in new-borns delivered by caesarean section as compared to those delivered vaginally, especially in the first few minutes of life and more in preterm than term new-borns. Conclusions: Unnecessary use of oxygen can be avoided by taking into account pulse oximetry. Separate sets of reference SpO 2 should be used for new-borns delivered by normal vaginal route and caesarean section.


Veterinary World | 2014

Cholesterol loaded cyclodextrin increases freezability of buffalo bull (Bubalus bubalis) spermatozoa by increasing cholesterol to phospholipid ratio.

J.S. Rajoriya; J. K. Prasad; Srikant Ghosh; Snehal S. Ramteke; N. C. Barik; G.K. Das; Megha Pande


Domestic Animal Endocrinology | 2014

Expression and localization of ghrelin and its functional receptor in corpus luteum during different stages of estrous cycle and the modulatory role of ghrelin on progesterone production in cultured luteal cells in buffalo

Mahesh Gupta; S.S. Dangi; V.S. Chouhan; I. Hyder; V. Babitha; V.P. Yadav; F.A. Khan; Arvind A. Sonwane; Gyanendra Singh; G.K. Das; Abhijit Mitra; Sadhan Bag; M. Sarkar

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J. K. Prasad

Indian Veterinary Research Institute

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M. Sarkar

Indian Veterinary Research Institute

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F.A. Khan

University of Florida

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Abhijit Mitra

Indian Veterinary Research Institute

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Brijesh Kumar

Central Drug Research Institute

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F.A. Khan

University of Florida

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I. Hyder

Indian Veterinary Research Institute

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J.S. Rajoriya

Indian Veterinary Research Institute

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Megha Pande

Indian Veterinary Research Institute

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R. Katiyar

Indian Veterinary Research Institute

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