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Biomedical subjects

M Mahony

Publications and source records attributed to M Mahony.

26 records · Page 2Linked to original sources
PubMed1993

Effect of progesterone on human zona pellucida sperm binding and oocyte penetrating capacity.

OBJECTIVE: To determine if sperm exposure to P produces an enhancement in its fertilizing capacity. DESIGN: Sperm from fertile donors were exposed to P at 0.1 and 1.0 microgram/mL for 1 or 24 hours. The effects on hyperactivated (HA) motility at 1 and 4 hours, acrosome reaction (as determined by Pisum sativum agglutinin or T6/antibody techniques), on human zona pellucida binding (by using the hemizona assay), and on the penetrating ability (by using the zona-free hamster ova assay) were evaluated. RESULTS: Exposure to P at 1.0 microgram/mL enhanced HA motility after 1 and 4 hours of P exposure, the acrosome reaction after 24 hours' incubation, the number of sperm bound/hemizona after 1-hour incubation, and the penetration rates in the hamster ova assay at both incubation intervals. CONCLUSION: Sperm exposure to P enhances its fertilizing capacity in fertile men, and further investigation is warranted as a possible treatment for male factor patients.

Acrosome↗
PubMed1989

Mouse monoclonal antibodies against human sperm: evidence for immunodominant glycosylated antigenic sites.

Thirty mouse monoclonal antibodies (MoAbs) raised against human sperm detect common antigenic determinants on human lymphocytes, erythrocytes, bacteria and endotoxin. Specific chemical, enzymatic and lectin blocking studies indicate that the sperm-associated antigens defined by these MoAbs are glycoconjugates. Further studies including reactivity of these MoAbs with organic sperm extracts indicate that the predominant carriers of these carbohydrate antigens are glycolipids and that the terminal immunodominant monosaccharide may be N-acetyl-glucosamine or N-acetylgalactosamine.

Animals↗
PubMedDate not supplied

Hemizona assay (HZA) demonstrates effects of characterized mouse antihuman sperm antibodies on sperm zona binding.

Characterized antihuman sperm monoclonal antibodies from mice were evaluated using the hemizona assay (HZA) to determine whether sperm:zona binding was effected. The seven monoclonal antibodies were characterized using human sperm in agglutination, immobilization, and penetration assays. Semen was provided by four fertile men and used in the HZA to determine if the presence of a monoclonal antibody would affect tight binding of the sperm to the zona pellucida. Pre-incubation of MA-14 for 1 h with the sperm induced a 33-54% reduction of the number of tightly bound sperm. This antibody reacts to an antigen located on the acrosome and midpiece. Experiments in which there was no pre-incubation of the antibody with sperm, resulted in no significant reduction in the number of sperm bound in the HZA. These findings suggest that an anti-human sperm antibody produced in mice can modulate sperm:zona binding. Reduction in zona binding could indicate a cause of immune-related infertility and this test may be useful in selecting an antigen for contraceptive vaccine development.

Acrosome↗
PubMedDate not supplied

The effect of saccharides on the post-thaw recovery of cane toad (Bufo marinus) spermatozoa.

The effect of monosaccharides (glucose, fructose) and disaccharides (maltose, sucrose, trehalose) as diluents, in cryoprotective additives containing 15% (v/v) DMSO or glycerol as cryoprotectants, were investigated on the recovery of sperm motility after cryopreservation of cane toad (Bufo marinus) spermatoazoa at low (approximately 5 degrees C/min(-1)) and high cooling rates (approximately 35 degrees C/min(-1)). The results show that: 1. recovery of percentage motility was higher with slow cooling than with high cooling rates (37.0 +/- 2.5%, 15.3 +/- 1.6%, P<0.001, respectively), 2. disaccharides were more effective than monosaccharides in protecting spermatozoa with slow cooling (43.9 +/- 1.2%, 26.8 +/- 2.5%, P<0.02, respectively), 3. glycerol was more effective than DMSO with fast cooling (18.3 +/- 2.2%, 12.6 +/- 2.3%, P<0.02, respectively), 4. trehalose with glycerol was the most effective cryoprotective additive with fast cooling (31.0 +/- 3.2%, P<0.05), and 5. overall the recovery of degree (vigour) of motility (range, 1.9 - 3.2) was more resilient to cryopreservation than recovery of percentage motility (range, 8.9 - 51.5 %). Comparison of post-thaw percentage and vigour of sperm motility up to 24 minutes after activation showed disaccharides supported greater duration sperm motility than monosaccharides This result and the recovery of spermatozoa immediately after freeze-thaw, show the main effect of saccharides are as cryoprotectants and not as exogenous energy substrates.

Animals↗
PubMedDate not supplied

The short-term storage and cryopreservation of spermatozoa from hylid and myobatrachid frogs.

The short-term storage (at 0 degrees C) and cryopreservation of spermatozoa may be useful for providing gametes for fertilisations performed in programmes for the conservation and management of endangered amphibians. The current study was undertaken to examine the applicability of amphibian spermatozoa storage protocols developed with the cane toad (Bufo marinus) to a wider range of amphibian species, with a view to ultimately using these protocols for endangered species. In Australia, at least 29 species of recently extinct or endangered frogs are from the families the Myobatrachidae and the Hylidae. This study investigated the applicability of short-term storage and cryopreservation protocols developed for cane toad (Bufo marinus) spermatozoa to those of hylid and myobatrachid species. Storage of spermatozoa in intact testes or in suspensions for six days at 0 degrees C showed spermatozoa maintained higher motility in suspensions than those in testes, and hylid spermatozoa maintained greater motility than myobatrachid spermatozoa. However, the protocols for optimal storage at 0 degrees C varied with testis size when spermatozoa were stored in whole testes. Spermatozoa from 13 frog species representing both families were cryopreserved using sucrose as diluent with Me(2)SO or glycerol as cryoprotectants. After cryopreservation hylid spermatozoa showed a greater recovery than myobatrachid spermatozoa and Me(2)SO provided higher recovery than glycerol. The freeze-thaw recovery of spermatozoa was independent of testes weight of the species studied. These results show spermatozoa from the Hylidae and Myobatrachidae may be stored both in the short-term (at 0 degrees C) and long-term by cryopreservation using protocols established for B. marinus.

Animals↗