Biomedical subjects

D Jayaprakash

Publications and source records attributed to D Jayaprakash.

7 recordsLinked to original sources

PubMed1997

Successful recovery of preimplantation embryos by nonsurgical uterine flushing in the bonnet monkey.

A major limitation to progress in primate embryology is the lack of an adequate supply of preimplantation embryos. We describe a method for recovering preimplantation-embryos in bonnet monkeys (Macaca radiata ) using a nonsurgical uterine flushing technique similar to the one previously employed in rhesus monkeys. Forty cyclic females were screened for cervical cannulation, and 10% of these had an impassable cervix. Eleven females suitable for cannulation were selected, and 27 menstrual cycles were monitored over a 5-mo period. Seventy-one percent of the cycles showed estrogen peaks, which were observed between Days 9 and 14 of the cycle. Following natural mating, uterine flushings were performed on Days 5 to 8 of pregnancy (Day 0 = the day following the estrogen peak). Of the 27 recovery attempts, 9 (33.3%) resulted in the recovery of ovulation products, including those of an unfertilized oocyte and empty zona (2 cases), retarded cleavage-stage (4 to 8-cell) embryos (4 cases), morula (1 case) and blastocysts (2 cases). These results show, for the first time, that the nonsurgical uterine flushing technique can be successfully performed to recover uterine-stage preimplantation embryos from bonnet monkeys.

Journal Article↗

PubMed1997

Pentoxifylline induces hyperactivation and acrosome reaction in spermatozoa of golden hamsters: changes in motility kinematics.

Pentoxifylline (PF) is used to enhance motility of spermatozoa from infertile human subjects. We have previously shown that 0.45 mM PF improved capacitation of spermatozoa and fertilization of oocytes in vitro in hamsters. The present study was carried out to assess PF-induced changes in motility kinematics of hamster spermatozoa by a computer-aided sperm analyser (CASA) and determine the timing of onset of hyperactivation (HA) and acrosome reaction (AR) in PF-treated spermatozoa. Motility kinematics were analysed by CASA for 0-8 h in the absence or presence of 0.45 mM PF in Tyrode's medium supplemented with lactate, pyruvate and polyvinyl alcohol (TLP-PVA) or in TLP-PVA with bovine serum albumin (TALP-PVA). Conventional assessment was also made on the percentage of motility and quality of motility of spermatozoa; values were expressed as sperm motility index (SMI). Both in TALP-PVA and TLP-PVA, PF markedly increased SMI, especially the quality of motility (P < 0.02) by 2-3 h which was sustained up to 6 h. The motility kinematic data of PF-treated spermatozoa in TALP-PVA showed that average path velocity, curvilinear velocity and amplitude of lateral head displacement significantly (P < 0.05) increased as early as 2 h, with the expected decrease in straightness (STR) and linearity (LIN). Similar changes were also observed with PF-treated spermatozoa in TLP-PVA. Moreover, the percentage of hyperactivated spermatozoa in PF-treated samples was significantly (P < 0.001) higher than the untreated control at 2 h. To determine whether PF could induce AR, independent of bovine serum albumin, quantitative AR was assessed by observing the presence or absence of acrosomal cap on viable spermatozoa. PF significantly (P < 0.001) increased the percentage of AR as early as 2 h, reaching maximum at 4 h both in TALP-PVA (P < 0.05) and in TLP-PVA (P < 0.001). These results show that, in hamsters, PF induces early onset (by 2 h) of HA and AR and increases the proportion of spermatozoa undergoing physiological maturation.

Acrosome↗

PubMed1997

Langur prostate and its hormonal modulation.

The normal histoarchitecture of langur prostate of different growth phases, viz., juvenile, sub-adult, and adult, and the hormonal modulation of adult prostate were studied in order to explore its suitability of a surrogate for human prostate. The histological observations revealed that the langur prostate is histoarchitecturally homogeneous. The volumetric composition of stroma (%) was found to be decreased significantly from juvenile to adult and that of epithelium and lumen was found to be increased significantly. The absolute volume (c.c.) of stroma, epithelium, and lumen increased significantly from juvenile to adult. A marked depletion in the various prostatic fluid biochemical parameters was observed in castration groups, which were recovered to control level following testosterone enanthate administration. The castration induced significant increase in volumetric composition of stroma; conversely that of the epithelium and lumen decreased significantly. The absolute volume of stroma did not show any appreciable variation, while that of epithelium and lumen decreased significantly. The inter acinar stroma decreased from juvenile to adult, while the lumen diameter increased significantly from juvenile to adult. Castration increased the inter acinar and lumen diameter; conversely the epithelial height decreased. The testosterone supplementation restored the prostate. However, the volumetric composition of stroma remained high, while the luminal volume remained low. Various prostatic parameters in normal and under altered hormonal conditions suggest that the langur prostate is similar to the human and therefore could be used as surrogate for the human prostate.

Age Factors↗

PubMed1995

Pentoxifylline improves sperm capacitation and in vitro fertilization of oocytes in the golden hamster.

Pentoxifylline (PF) is used to improve motility of spermatozoa from subfertile or nonfertile males to accomplish in vitro fertilization in humans. The possible adverse effect of PF on pre- and peri-implantation stage embryo development in a suitable rodent model, such as the golden hamster, is yet to be determined. In this study, hamster cauda epididymal spermatozoa were exposed to different concentrations (0.23 to 3.6 mM) of PF, and their quantitative [percentage of motility] and qualitative [Score 0 to 5] motility were assessed and values expressed as the sperm motility index. Upon addition of spermatozoa to dishes containing PF, an immediate increase in sperm motility and sperm motility index was evident, which increased up to 4 to 6 h and then declined. The sperm motility index increase by PF was dose-dependant, and >or= 1.8 mM PF was detrimental after 4 h. The optimum dose of PF was found to be 0.45 mM. To assess the fertilizing ability of PF-treated spermatozoa, in vitro fertilization was carried out. Fertilization rates for spermatozoa treated with 3.6 mM PF were lower (53.8 +/- 7.8) than for the controls (69.5 +/- 10.2), whereas treatment with 0.45 mM PF increased the rates (91.6 +/- 4.3) compared with that of the controls (80.2 +/- 5.9). In conclusion, low concentrations (0.23 to 0.45 mM) of PF improve sperm capacitation and fertilization of oocytes in vitro in the golden hamster.

Journal Article↗

PubMed1994

Antifertility effects of aqueous extract of Carica papaya seeds in male rats.

The influence of the crude aqueous extract of Carica papaya L. (Caricaceae) seeds has been studied on semen profile, fertility, body and organ weight response, and toxicology in male albino rats. The extract was administered at the dose regimens of 10 and 50 mg/animal/day orally for 30, 60, and 90 days and 0.1 and 1.0 mg/animal/day intramuscularly for 15 and 30 days. Cauda epididymal sperm motility and count was reduced significantly at low and high dose regimens both in the oral as well as the intramuscular groups. The reduced sperm motility was associated with morphological defects. Testicular sperm counts were also reduced in all the treatment groups except the low dose intramuscular group. Fertility tests showed dose- and duration-dependent reduction and zero fertility was observed at high dose regimens of the oral and intramuscular groups following 60 and 30 days of treatment, respectively. Testicular weight was reduced in all the treatment groups, whereas accessory sex organs showed a variable response. Body weight and toxicological observations did not show any untoward response. Fertility and all other associated changes returned to normal within 45 and 30 days of treatment cessation in the oral and intramuscular groups, respectively. The data revealed that reversible sterility could be induced in male rats by papaya seeds aqueous extract treatment without adverse effects on libido and toxicological profile.

Animals↗

PubMed1991

Experience with a potent LH-RH agonist, buserelin, alone and in combination with testosterone for antispermatogenic activity, reversibility and toxicity in langur monkey.

Chronic intermittent treatment of LH-RH superagonist Buserelin alone or in combination with testosterone enanthate were given to adult male langurs for 90 days to evaluate antispermatogenic activity of alone and combination therapy, maintenance of normal androgenicity, possible toxic effects of agonist treatment, related side effects of testosterone supplementation and complete reversibility of the procedure. A gradual decrease in sperm count was recorded in both treatment groups, along with reduced motility and vitality of the spermatozoa. In the combination group, oligospermia was achieved in 4 out of 5 animals, whereas, only 2 animals became oligospermic in the agonist alone group. Significant decrease in serum testosterone levels along with impaired libido and other testosterone withdrawal symptoms were observed in the Buserelin alone group, conversely normal testosterone levels and libido were observed in the combination group. An elevation in haematological variables and serum total protein concomitant with a slight gain in body weight of the animals were recorded in the combination group; these changes were not encountered in the agonist alone group. Reversibility of all the altered parameters to control range was observed in both treatment groups following 75 to 90 days of treatment withdrawal.

Acid Phosphatase↗

PubMedDate not supplied

Semen characteristics of the captive Indian leopard, Panthera pardus.

Semen samples from 11 Indian leopards (Pantherapardus) from 3 different zoos in India were collected by electroejaculation. A computer-aided semen analyzer (CASA) was used for assessing the quality of the semen vis-à-vis sperm motility. The volume of the ejaculate, sperm density, and the number of motile and morphologically normal spermatozoa were found to be 1.57 +/- 1.26 mL, 55.78 million +/- 38.67 million per mL, 57.05% +/- 16.96% and 71.92% +/- 15.32%, respectively. Although the spermatology varied between individuals in the study, Box-Whisker-plot analysis suggested that the distribution was normal (P > .05). The ejaculated sperm were cryopreserved after diluting in test-yolk buffer. The post-thaw motility was 32.14% and did not differ at 30 or 60 days after cryopreservation. CASA indicated that the progressive velocity (VSL) of cryopreserved spermatozoa was decreased and, as a consequence, they moved more slowly than the neat (VSL 76.3 microm/sec in neat vs 53.8 microm/sec in cryopreserved spermatozoa) and the trajectories were less planar. However, both cryopreserved and neat spermatozoa penetrated the zona-free hamster oocyte with equal efficiency (79% neat vs 80% cryopreserved). The study also reports application of CASA for feline spermatozoa and provides information for the first time on the spermatology of the Indian leopard. This baseline data could be used in captive breeding programs. The results are compared and discussed with the available information on other felines.

Animals↗