1
|
Doumouchtsis SK, Nikolopoulos K, Talaulikar VS, Krishna A, Arulkumaran S. Menstrual and fertility outcomes following the surgical management of postpartum haemorrhage: a systematic review. BJOG 2013; 121:382-8. [DOI: 10.1111/1471-0528.12546] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2013] [Indexed: 11/29/2022]
|
|
12 |
50 |
2
|
Marcinkiewicz JL, Krishna A, Cheung CM, Terranova PF. Oocytic tumor necrosis factor alpha: localization in the neonatal ovary and throughout follicular development in the adult rat. Biol Reprod 1994; 50:1251-60. [PMID: 7521675 DOI: 10.1095/biolreprod50.6.1251] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Tumor necrosis factor alpha (TNF alpha) has previously been immunolocalized within mouse oocytes. Our first objective was to examine TNF alpha immunolocalization in ovaries of adult, fetal, and neonatal rats. Our second objective was to examine TNF alpha mRNA in ovaries by Northern blot analysis and in oocytes by reverse-transcriptase polymerase chain reaction (RT-PCR). Our final objective was to determine whether oocytes contained bioactive TNF alpha. Ovaries and oviducts were collected throughout the estrous cycle in adult rats, fetal ovaries were obtained 1 day before expected delivery, and neonatal ovaries were collected 2 days after birth. TNF alpha was localized in tissues by a biotin-avidin immunocytochemical procedure. Immunocytochemistry in adult ovaries showed that the ooplasm of the oocyte was the primary site of TNF alpha localization within the follicle. Immunostaining was present in all oocytes in the adult, including ovulated oocytes within the oviduct. Oocytic TNF alpha immunostaining was also present within oocytes in the neonate; however, fetal oocytes did not contain immunoreactive TNF alpha. Northern blots showed that ovaries in the adult, neonate, and fetus all contained TNF alpha mRNA. RT-PCR analysis of oocytes collected from preovulatory follicles generated a cDNA band of 500 bp, corresponding to the predicted size for amplified TNF alpha cDNA. Subsequent Southern blot analysis showed that the 500-bp band hybridized to the TNF alpha probe, indicating that preovulatory oocytes contain TNF alpha mRNA. Preovulatory oocytes were used in TNF alpha cytotoxicity assays with L929 cells. Oocytes contained TNF alpha bioactivity that was similar to that of recombinant murine TNF alpha in the bioassay. Our results provide evidence for the identification of immunoreactive and bioactive TNF alpha within oocytes in the rat, which is further supported by the presence of TNF alpha mRNA within the oocyte. These studies also indicate that TNF alpha may appear in the oocyte around the time of birth.
Collapse
|
|
31 |
50 |
3
|
Krishna A. High androgen production by ovarian thecal interstitial cells: a mechanism for delayed ovulation in a tropical vespertilionid bat, Scotophilus heathi. JOURNAL OF REPRODUCTION AND FERTILITY 1996; 106:207-11. [PMID: 8699403 DOI: 10.1530/jrf.0.1060207] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The steroid hormone profile of Scotophilus heathi, and Indian tropical vespertilionid bat, was studied, with special reference to the period of delayed ovulation. The results show unusually high concentrations of circulating androstenedione and testosterone during the first half of the period of delayed ovulation, whereas the concentrations of progesterone and oestradiol were relatively low during this period. Androstenedione, testosterone and oestradiol concentrations were high during the period of ovarian recrudescence (October-November). The oestradiol concentration increased, whereas androstenedione and testosterone declined significantly, before ovulation. Studies in vitro showed that the ovary secrets more androstenedione and testosterone than does the adrenal. A histological study showed that a major part of the ovary of S. heathi was occupied by hypertrophied interstitial cells. An immunocytochemical study showed ovarian thecal interstitial cells as the major site of high androgen synthesis in the ovary. During the period of delayed ovulation the bat ovaries thus resemble the ovaries from women with polycystic ovaries in which abnormally high androgen secretion from hypertrophied interstitial cells prevent ovulation.
Collapse
|
|
29 |
47 |
4
|
Nakamura Y, Smith M, Krishna A, Terranova PF. Increased number of mast cells in the dominant follicle of the cow: relationships among luteal, stromal, and hilar regions. Biol Reprod 1987; 37:546-9. [PMID: 3676403 DOI: 10.1095/biolreprod37.3.546] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The number of mast cells per microscopic field at 450X (0.123 mm2) was determined in the bovine ovary on Days 4, 10, and 19 of the cycle (Day 0 = estrus). Mast cells were observed in the theca externa of follicles, the external capsule of the corpus luteum, and in the stromal and hilar regions of the ovary. The stromal and hilar regions exhibited the highest number of mast cells (per field = 7.51-10.15) compared with the follicular and luteal compartments (2.65-3.70 mast cells/field). Most interestingly, on Day 19 a significant increase in the number of mast cells was observed in the theca externa of the dominant follicle (10.4 mast cells/field) compared with nondominant healthy follicles on Days 4 and 10 (2-3/field). After ovulation, the number of mast cells surrounding the corpus luteum on Day 4 was significantly lower than 19 values in the dominant follicle; this was further diminished on Day 10 of the cycle. These results indicate that the increase in mast cells associated with the dominant follicle on Day 19 may be related to its development and the decline in mast cells related to ovulation.
Collapse
|
|
38 |
42 |
5
|
Abstract
Mast cells, endothelial cells, basophils and platelets are potential sources of histamine in the ovary. Little is known about the role of the latter three cell types in ovarian function. Several studies have revealed changes in the number and degranulation (release of histamine) of mast cells in the ovary during the cycle. Mast cells degranulate on pro-oestrus in the rodent ovary, and mast cells numbers increase in the theca externa of the dominant follicle in the bovine ovary. In rodents, mast cells are limited to the ovarian hilum and are not observed in follicles, corpora lutea and interstitium; this contrasts with larger species such as man, cows and monkeys where mast cells are observed throughout the ovary. Evidence is accumulating that mast cell degranulation in the ovary may be regulated by neuronal input. Neurones have been shown to have close morphological relationships with mast cells in the ovary. Histamine participates in regulating capillary permeability and blood flow in the ovary. These actions are induced by injections of LH, yet the mechanism by which LH induces mast cell degranulation is unknown. Histamine stimulates ovarian contractility, ovulation and follicular progesterone secretion in vitro. Whether these actions of histamine occur in vivo are currently unknown. This review gives a chronological description of the discoveries of the effects of histamine on ovarian function and makes suggestions for future research in this area.
Collapse
|
Review |
36 |
38 |
6
|
Krishna A, Terranova PF. Alterations in mast cell degranulation and ovarian histamine in the proestrous hamster. Biol Reprod 1985; 32:1211-7. [PMID: 2410041 DOI: 10.1095/biolreprod32.5.1211] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mast cells in the ovary of cyclic hamsters were observed exclusively in the hilum and in the vicinity of blood vessels that enter and exit the ovary. Ovaries were collected on proestrus from hamsters at 0900 h preluteinizing hormone (LH) surge, 1500 h (peak LH surge), and 2100 h (post-LH surge) and processed for routine histologic staining with toluidine blue. A significant increase in the percentage of extensively degranulating mast cells was observed coincident with the gonadotropin surge (0900 h: 5.39 +/- 0.97%; 1500 h: 20.39 +/- 2.76%). At the peak of the LH surge the ovarian histamine concentration was also significantly higher than those before and after the surge (1500 h: 5.13 +/- 0.94 ng/mg ovary; 0900 h and 2100 h: 2.84 +/- 0.35 and 3.02 +/- 0.48 ng/mg, respectively). The results indicate that a major source of ovarian histamine may be mast cells residing in the ovarian hilum and surrounding the ovarian blood vessels that enter and exit the ovary. In addition, the gonadotropin surge on the day of proestrus may be a trigger for release of mast cell histamine.
Collapse
|
|
40 |
37 |
7
|
Krishna A, Rickard MJFX, Keshava A, Dent OF, Chapuis PH. A comparison of published rates of resection margin involvement and intra-operative perforation between standard and 'cylindrical' abdominoperineal excision for low rectal cancer. Colorectal Dis 2013; 15:57-65. [PMID: 22757637 DOI: 10.1111/j.1463-1318.2012.03167.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
AIM The study aimed to compare recent reports on standard and alternative methods of abdominoperineal excision for low rectal cancer regarding the rates of circumferential resection margin involvement and intra-operative bowel perforation. METHOD Data on rates of margin involvement and perforation were obtained from eight recently published reports and also from a prospective registry of resections at Concord Hospital. Rates of these outcomes and their 95% confidence intervals were evaluated. RESULTS There was no evidence that extralevator abdominoperineal excision yielded significantly lower rates of resection margin involvement or intra-operative bowel perforation compared with standard abdominoperineal excision in six independent hospital- and population-based patient series. Abdominosacral resection of the rectum, on the other hand, did show significantly lower rates of these endpoints, albeit in selected patients. CONCLUSION The role of extralevator abdominoperineal excision and abdominosacral resection of the rectum should be investigated further in randomized controlled trials.
Collapse
|
Comparative Study |
12 |
34 |
8
|
Krishna A, Gough DC. Evaluation of augmentation cystoplasty in childhood with reference to vesico-ureteric reflux and urinary infection. BRITISH JOURNAL OF UROLOGY 1994; 74:465-8. [PMID: 7820425 DOI: 10.1111/j.1464-410x.1994.tb00424.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES To assess the non-operative treatment of vesico-ureteric reflux in patients with abnormal bladder compliance, to determine whether reduction in storage pressure by augmentation leads to cessation of reflux and whether symptomatic urinary tract infection worsens or renal function deteriorates if reflux continues after augmentation and clean intermittent catheterization (CIC). PATIENTS AND METHODS Thirty-nine children (17 boys, 22 girls) who underwent clam ileocystoplasty over a 5-year-period were evaluated. The mean age at operation was 9.7 years (range 1.5-17.5). Pre-operative assessment included renal imaging and slow fill video-cystometry. Vesico-ureteric reflux, if present, was graded I-V. The frequency and severity of symptomatic urinary tract infections were recorded. Cystometry was performed 6 months after reconstruction. Storage pressures below 20 cm saline were regarded as safe. The mean follow-up was 3.3 years (range 10 months-6.1 years). RESULTS Of the 17 renal units assessed for the outcome of reflux, 11 stopped reflux and one showed a lower grade. No patient showed worsening of upper tract dilatation or progressive renal scarring. Thirty-seven patients (95%) had symptomatic urinary tract infection pre-operatively. Following bladder augmentation, clean intermittent catheterization and trimethoprim prophylaxis, seven continued to have symptomatic infection. CONCLUSIONS Augmentation cystoplasty is effective in resolving reflux in a majority of the patients. This is achieved by reducing storage pressures to below 20 cm saline and emptying the bladder regularly by CIC. There is also a reduction in the incidence and severity of symptomatic urinary tract infections. Even when reflux persists there is no evidence of deterioration of the upper tracts or progressive renal scarring.
Collapse
|
|
31 |
34 |
9
|
Pandey G, Kumaraswamy G, Krishna A. Photosensitized single electron transfer oxidation of N-hydroxylamines: A convenient synthesis of cyclic nitrones. Tetrahedron Lett 1987. [DOI: 10.1016/s0040-4039(00)96172-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
|
38 |
32 |
10
|
Sinha A, Bagga A, Krishna A, Bajpai M, Srinivas M, Uppal R, Agarwal I. Revised guidelines on management of antenatal hydronephrosis. Indian J Nephrol 2013; 23:83-97. [PMID: 23716913 PMCID: PMC3658301 DOI: 10.4103/0971-4065.109403] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.
Collapse
|
review-article |
12 |
32 |
11
|
Meenakumari KJ, Agarwal S, Krishna A, Pandey LK. Effects of metformin treatment on luteal phase progesterone concentration in polycystic ovary syndrome. Braz J Med Biol Res 2004; 37:1637-44. [PMID: 15517078 DOI: 10.1590/s0100-879x2004001100007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The causes of luteal phase progesterone deficiency in polycystic ovary syndrome (PCOS) are not known. To determine the possible involvement of hyperinsulinemia in luteal phase progesterone deficiency in women with PCOS, we examined the relationship between progesterone, luteinizing hormone (LH) and insulin during the luteal phase and studied the effect of metformin on luteal progesterone levels in PCOS. Patients with PCOS (19 women aged 18-35 years) were treated with metformin (500 mg three times daily) for 4 weeks prior to the test cycle and throughout the study period, and submitted to ovulation induction with clomiphene citrate. Blood samples were collected from control (N = 5, same age range as PCOS women) and PCOS women during the late follicular (one sample) and luteal (3 samples) phases and LH, insulin and progesterone concentrations were determined. Results were analyzed by one-way analysis of variance (ANOVA), Duncan's test and Karl Pearson's coefficient of correlation (r). The endocrine study showed low progesterone level (4.9 ng/ml) during luteal phase in the PCOS women as compared with control (21.6 ng/ml). A significant negative correlation was observed between insulin and progesterone (r = -0.60; P < 0.01) and between progesterone and LH (r = -0.56; P < 0.05) concentrations, and a positive correlation (r = 0.83; P < 0.001) was observed between LH and insulin. The study further demonstrated a significant enhancement in luteal progesterone concentration (16.97 ng/ml) in PCOS women treated with metformin. The results suggest that hyperinsulinemia/insulin resistance may be responsible for low progesterone levels during the luteal phase in PCOS. The luteal progesterone level may be enhanced in PCOS by decreasing insulin secretion with metformin.
Collapse
|
Research Support, Non-U.S. Gov't |
21 |
29 |
12
|
Krishna A, Gough DC, Fishwick J, Bruce J. Ileocystoplasty in children: assessing safety and success. Eur Urol 1995; 27:62-6. [PMID: 7744145 DOI: 10.1159/000475126] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
From 1987 to 1992, bladder augmentation using clam ileocystoplasty was performed in 39 children 1.5-17.5 years old (mean age 9.7 years). Indications for augmentation included neuropathic bladder, epispadias-exstrophy complex and posterior urethral valves. A satisfactory bladder capacity at safe storage pressures of < 20 cm saline was achieved in all patients. Hydroureteronephrosis resolved or improved in 33 of the 36 moieties (91.7%). No patient showed biochemical or radiological deterioration of the upper tracts. The incidence of symptomatic urinary tract infection fell significantly postoperatively. Seven patients (17.9%) developed a total of 10 complications, with rupture of the augmented bladder occurring in 4 patients (10.3%).
Collapse
|
|
30 |
27 |
13
|
Singh K, Krishna A. Seasonal changes in circulating serum concentration and in vitro testicular secretion of testosterone and androstenedione in the male vespertilionid bat (Scotophilus heathi). THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1996; 276:43-52. [PMID: 8828184 DOI: 10.1002/(sici)1097-010x(19960901)276:1<43::aid-jez5>3.0.co;2-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Seasonal changes in the testicular activity were studied in the male Greater Yellow bat, Scotophilus heathi, in Varanasi, India (25 degrees N, 83 degrees E). The seasonal pattern of body weight of male bats was also recorded and compared with circulating androstenedione (A) and testosterone (T) concentration. There was a gradual increase in the body weight of the bat from September onward mainly due to accumulation of adipose tissue. Finally, body weight reached a peak level in November. Two periods of peak testicular weight and serum T concentration but only one peak of serum A concentration were observed. The first peak of T coincided closely with the peak A concentration and increased body weight. The first peak of T occurs several months before the time of mating and ovulation. The second peak of T correlated closely with the period of mating. In vitro study showed seasonal variation of the testicular responsiveness to LH stimulation. In vitro study also showed two peaks in the T but only one peak in the A production by testes in response to LH during different phases. Preliminary study showed that IGF-I but not insulin augmented hCG induced T production by testes in vitro. Our observation of an increase in serum A concentration during the period of overfeeding and weight gain and decline in A during the period of weight loss in S. heathi adds strength to the concept that nutritional status can influence hormonal function. This may be the reason for asynchrony between male and female gametic cycle found among vespertilionid bats.
Collapse
|
|
29 |
26 |
14
|
Doval J, Krishna A. Ovarian androstenedione production is enhanced by insulin during the period of delayed ovulation in a vespertilionid bat, Scotophilus heathi. JOURNAL OF REPRODUCTION AND FERTILITY 1998; 114:63-8. [PMID: 9875156 DOI: 10.1530/jrf.0.1140063] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The aim of the present study was to evaluate the role of insulin in the production of high concentrations of androstenedione in the ovary of Scotophilus heathi during the period of delayed ovulation. The concentrations of serum insulin were found to be high during November and December and declined significantly before ovulation. A significant correlation was observed between circulating insulin concentration and body weight as well as with serum androstenedione concentrations. Autoradiographic study demonstrated specific accumulation of 125I-labelled insulin in the ovarian thecal and interstitial cells. Insulin increased both basal and hCG-stimulated androstenedione production by the ovary in vitro during November. These results indicate that insulin may be involved in inducing high androstenedione synthesis by the ovary and thus may be indirectly responsible for inducing delayed ovulation in S. heathi.
Collapse
|
|
27 |
25 |
15
|
Krishna A, Dominic CJ. Storage of spermatozoa in the female genital tract of the vespertilionid bat, Scotophilus heathi. JOURNAL OF REPRODUCTION AND FERTILITY 1978; 54:319-21. [PMID: 569203 DOI: 10.1530/jrf.0.0540319] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Spermatozoa were observed in all parts of the genital tract in females killed in January, February, March and April although copulation occurs only until early February. The spermatozoa were arranged linearly with their heads orientated towards the epithelial lining.
Collapse
|
|
47 |
23 |
16
|
Ahuja S, Datta A, Krishna A, Bhattacharya A. Infra-orbital nerve block for relief of postoperative pain following cleft lip surgery in infants. Anaesthesia 1994; 49:441-4. [PMID: 8209992 DOI: 10.1111/j.1365-2044.1994.tb03484.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The study was conducted on 20 infants scheduled for cleft lip repair surgery. Ten were randomly allocated to receive bilateral infra-orbital local anaesthetic nerve blocks at the conclusion of surgery with the other 10 receiving bilateral 'sham' blocks as controls. Postoperative pain relief was assessed using a pain assessment scoring system and by monitoring arterial blood pressure, heart rate and respiratory rate. The mean pain assessment score was significantly higher (i.e. better) (p < 0.05) in the infants receiving the local anaesthetic block. There were no significant statistical or clinical differences in the physiological measurements between the two groups. The infants receiving the block required less analgesia in the postoperative period. The results suggest that infra-orbital nerve block is a simple and effective means of achieving postoperative analgesia after cleft lip repair surgery in infants.
Collapse
|
Clinical Trial |
31 |
22 |
17
|
Tripathi V, Krishna A. Changes in nitric oxide (NO) synthase isoforms and NO in the ovary of Heteropneustes fossilis (Bloch.) during the reproductive cycle. J Endocrinol 2008; 199:307-16. [PMID: 18772166 DOI: 10.1677/joe-07-0509] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The purpose of the study was to demonstrate the presence of nitric oxide (NO) synthase (NOS) isoforms (neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS)) and the role of NO in the ovary of Heteropneustes fossilis. In one half of the ovary collected during different reproductive stages, NOS isoforms were localized immunohistochemically in paraffin sections whereas the other half was processed for NOS and NO quantification using western blot followed by densitometry and nitrate/nitrite assay respectively. The role of NO on oocyte maturation was studied by examining the effect of NO donor (sodium nitroprusside; SNP) and NOS inhibitor (Nomega-nitro-l-arginine methyl ester) on 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-P)-induced germinal vesicle breakdown (GVBD) in the cultured oocyte collected during prespawning phase. NOS immunostaining was predominantly localized in previtellogenic follicles, with nNOS detected in the nucleus and cytoplasm of oocytes whereas iNOS and eNOS localized in granulosa, theca cells, and cytoplasm of oocytes. The NOS expression was higher in previtellogenic phase when compared with vitellogenic phase. The nitrate/nitrite concentrations in ovary showed gradual increase from recrudescence (4.9+/-0.19 nM/mg protein) to late previtellogenic phase (7.02+/-0.53 nM/mg protein), but showed a sharp decline during the vitellogenic phase (0.41+/-0.053 nM/mg protein). Serum and ovarian nitrate/nitrite level showed a close association during the reproductive cycle. The results showed an increase in NOS activity and nitrate/nitrite concentrations as the follicle grow suggesting involvement of NO in follicular development. SNP significantly inhibited 17alpha,20beta-P-induced GVBD in fish oocytes. Thus, it is concluded that the fish ovary possesses NOS/NO system and a possibility that NO has a role in follicular development and regulation of oocyte maturation in fish, H. fossilis.
Collapse
|
|
17 |
21 |
18
|
Ranjan A, Choubey M, Yada T, Krishna A. Nesfatin-1 ameliorates type-2 diabetes-associated reproductive dysfunction in male mice. J Endocrinol Invest 2020; 43:515-528. [PMID: 31691259 DOI: 10.1007/s40618-019-01136-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/25/2019] [Indexed: 12/19/2022]
Abstract
PURPOSE The present study was aimed to demonstrate the recuperative effect of nesfatin-1 on testicular dysfunction in the high-fat diet (HFD)/streptozotocin (STZ)-induced type-2 diabetes mellitus (T2DM) mice. METHOD AND RESULTS Three experimental groups were formed: (1) vehicle control (VC), (2) T2DM mice, (3) T2DM + nesf-1. The mice with blood glucose level higher than 300 mg/dL following HFD and a single dose of STZ were used for the experiment. The T2DM mice showed increases in body mass, blood glucose and insulin levels, reductions in spermatogenesis and steroidogenesis, production of antioxidative enzymes, and disturbed lipid profile. These alterations were all ameliorated by administration of nesfatin-1 at 20 μg/Kg BW for 15 days. Nesfatin-1 treatment also increased the production of testosterone (T), improved insulin sensitivity, and effectively ameliorated the testicular aberrations, and increased spermatogenesis and steroidogenesis. In addition, nesfatin-1 treatment upregulated the PCNA and Bcl2 expression and inhibited the caspase-3 and prohibitin expression in T2DM mice. Nesfatin-1 increased insulin receptor (IR) and GLUT8 expressions, and lactate production, the changes that further substantiate the increase of energy influx to the testis. CONCLUSION Altogether, the results suggest the ameliorative effect of nesfatin-1 against T2DM-associated testicular dysfunctions and improved insulin sensitivity along with promoting T production and fertility in T2DM mice.
Collapse
|
|
5 |
19 |
19
|
Srivastava RK, Krishna A, Sridaran R. Follicular development, steroidogenesis and gonadotrophin secretion in response to long-term treatment with a gonadotrophin-releasing hormone agonist in the rat. J Endocrinol 1995; 146:349-57. [PMID: 7561648 DOI: 10.1677/joe.0.1460349] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Gonadotrophin-releasing hormone (GnRH) and its agonists are implicated in the local control of rat ovarian function. We have evaluated the effects of long-term administration of different doses of GnRH agonist (GnRH-Ag) in vivo (a) on reproductive cyclicity and follicular development, (b) on peripheral gonadotrophin and steroid concentrations and (c) on in vitro cAMP and progesterone production by the follicles in response to stimulatory doses of FSH or LH (1 microgram/ml). GnRH-Ag (0.2, 1 or 5 micrograms/day) administration for 28 days had a profound impact on the oestrous cycle of rats as revealed by vaginal cytology. GnRH-Ag treatment caused a decrease in ovarian and uterine weights, which correlated very well with the decrease in the number of follicles present in the ovary. GnRH-Ag (5 micrograms/day) reduced the number of early preantral follicles and there was complete disappearance of early as well as late antral follicles. However, a dose of 1 microgram GnRH-Ag/day was effective in the complete demise of only late antral follicles with a significant attenuation in the number of early antral follicles. There was an enhancement in serum LH concentrations in response to the highest dose of GnRH-Ag administration with serum FSH concentrations declining in rats treated with the two higher doses. However, serum prolactin concentrations were attenuated only in rats treated with the highest dose of GnRH-Ag. GnRH-Ag treatment decreased serum progesterone and oestradiol concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
|
30 |
18 |
20
|
Krishna A, Dominic CJ. Differential rates of fetal growth in two successive pregnancies in the emballonurid bat, Taphozous longimanus Hardwicke. Biol Reprod 1982; 27:351-3. [PMID: 7126734 DOI: 10.1095/biolreprod27.2.351] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
|
Comparative Study |
43 |
18 |
21
|
Krishna A, Singh K, Doval J, Chanda D. Changes in circulating insulin and corticosterone concentrations during different reproductive phases and their relationships to body weight and androstenedione concentration of male Scotophilus heathi. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1998; 281:201-6. [PMID: 9621439 DOI: 10.1002/(sici)1097-010x(19980615)281:3<201::aid-jez5>3.0.co;2-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The aim of the present study was to determine the serum levels of insulin and corticosterone during different reproductive stages in a natural population of the male bat, Scotophilus heathi and their relationship to body weight and androstenedione level. Changes in body weight were marked by weight gain before winter dormancy and weight loss during winter dormancy. Circulating insulin level varied significantly over the season and correlated positively with changes in body weight and androstenedione level. Circulating corticosterone level also varied significantly over the season but correlated negatively with changes in body weight and androstenedione level. High corticosterone level during August coincided with a period of increased feeding activity in this species. The results suggest that insulin may act as an anabolic agent to promote fat deposition and corticosterone exerts a predominantly fat-mobilizing influence. A high insulin level prior to winter dormancy may be an important factor responsible for inducing high androstenedione concentration shown in Scotophilus heathi.
Collapse
|
|
27 |
17 |
22
|
Abstract
A technique of nipple reconstruction using two local flaps is described. The central 'core' flap is surrounded by a peripheral 'wrap' flap, producing a natural nipple. Results of 24 nipple reconstructions in 22 cases are presented. This technique is useful when the neo-nipple location falls on the mastectomy scar.
Collapse
|
|
28 |
16 |
23
|
Abstract
An accessory limb associated with spina bifida was already reported by the authors. We had then described it as a result of a very early splitting of the limb bud arising from the paraxial mesoderm. We have subsequently seen three other such cases, which are described in this report as well as a review of five other cases in the literature. It is proposed that the growth of the accessory limb occurs from a mesodermal blastema that is a result of de-differentiation from Schwann cells.
Collapse
|
Review |
26 |
16 |
24
|
Krishna A, Raghubir P. The effect of line configuration on perceived numerosity of dotted lines. Mem Cognit 1997; 25:492-507. [PMID: 9259627 DOI: 10.3758/bf03201125] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Estimates the number of objects in a line are made in many different situations. This paper demonstrates that besides the actual number of dots, aspects of line configuration affect the perceived numerosity of dotted lines. Experiment 1 provides evidence that the highly studied "clutter effect" in distance perception research replicates to the numerosity domain so that lines made up of more segments are perceived to contain more dots. Experiments 2-5 provide nomological validity for the recently proposed "direct distance" effect in distance perceptions by showing that numerosity perceptions are higher the greater the euclidean length between the line end points and by manipulating euclidean length in three orthogonal ways: the relative length of segments (Experiment 2), the angle between segments (Experiment 3), and the general direction of segments (Experiment 4). Experiment 5 conceptually replicates the results of Experiments 2-4 utilizing stimuli-based versus memory-based judgments and a discrimination task. Experiments 6 and 7 extend the research on spatial perception by demonstrating that the use of euclidean length as a source of information is inversely related to line width, with width varied through clutter (Experiment 6) and total line length (Experiment 7). Overall, the results demonstrate that the robustness of the euclidean length effect is contingent on the salience of alternative spatial heuristics--specifically, euclidean width. Theoretical implications are discussed.
Collapse
|
|
28 |
15 |
25
|
Krishna A, Terranova PF, Matteri RL, Papkoff H. Histamine and increased ovarian blood flow mediate LH-induced superovulation in the cyclic hamster. JOURNAL OF REPRODUCTION AND FERTILITY 1986; 76:23-9. [PMID: 3944794 DOI: 10.1530/jrf.0.0760023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Constant infusion of LH (400 micrograms NIH-S24) through an osmotic minipump inserted on Day 1 (oestrus) of the cycle in the hamster resulted in spontaneous superovulation (approximately equal to 29 ova) at the next expected oestrus, increased blood flow (P less than 0.001) to the ovary on Day 3, and slight depletion (0.1 greater than P greater than 0.05) of histamine in the ovary. Treatment with antihistamine (alpha-fluoromethylhistidine, an irreversible inhibitor of histidine decarboxylase, or cimetidine, an H2 blocker) by injections or by infusion using separate osmotic minipumps significantly (P less than 0.01) reduced the number of ova shed in the LH-treated hamsters. Infusion of LH with alpha-fluoromethylhistidine in the same osmotic minipump reduced the bioactivity of the LH. Infusion of antihistamine alone did not alter the normal number of ova shed. The results suggest that the LH-induced superovulation involves stimulation of histamine release; the histamine than may increase ovarian blood flow thus allowing more gonadotrophins to reach the ovary.
Collapse
|
|
39 |
15 |