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Biomedical subjects

B J Rogers

Publications and source records attributed to B J Rogers.

At least 73 records · Page 4Linked to original sources
PubMed1985

Monitoring of suspected infertile men with varicocele by the sperm penetration assay.

Although varicocele remains the most frequently diagnosed cause of male infertility, and improvement in semen quality is associated with repair of varicocele, improvement in spermatozoal fertilizing capacity has not been conclusively demonstrated. The sperm penetration assay was employed to monitor prospectively surgical (n = 59) and nonsurgical (n = 40) groups of men with varicocele. There were no significant increases in the average count, motility, morphologic features, or sperm penetration assay results for either group. Varicocele surgery enhanced assayable egg penetration rates in 14 of the 59 patients (23.7%), whereas the nonsurgical group had 10% spontaneous improvement. Of those in the surgery group who showed assayable fertility enhancement and were attempting conception, pregnancies were achieved in 70% (7 of 10 patients). Of patients in the nonsurgical group who improved in the assay, no pregnancies were obtained.

Adult↗
PubMed1983

Anisotropies in the perception of three-dimensional surfaces.

The appearance of certain three-dimensional surfaces was found to depend on the orientation of the depth contours forming the surface. This was true both when the depth was specified by motion parallax and when it was specified by binocular disparities. Slowly changing depth surfaces that generated a pattern of relative motions or disparities characterized by a one-dimensional expansion-compression were perceived differently from those that produced a shear transformation.

Depth Perception↗
PubMed1983

Variability in the human-hamster in vitro assay for fertility evaluation.

Sources of variability in the zona-free hamster egg penetration assay were evaluated. Internal consistency in the assay was examined in replicate experiments using sperm from 23 donors. The average difference in the percentage of fertilization between the replicates was 3.9%. Optimal preincubation conditions and insemination time were examined and shown to be 0.5 to 1.0 X 10(7) sperm/ml and 2 to 3 hours. Abstinence time was found to be a variable, and a critical abstinence of more than 12 hours was required. Prolonged exposure to seminal plasma (i.e., more than 30 minutes) produced a reduction in the fertilization test results. If the variables studied here are consistently controlled, then changes in the assay results greater than the experimental error should reflect true changes in the semen sample.

Animals↗
PubMed1982

In vitro fertilization rates after varicocele repair.

Causal relationship of varicocele to infertility is controversial. Studies of hormonal milieu, semen and testicular tissue yield data of debatable significance. We herein assay the fertilizing ability of men with varicocele and monitor changes consequent to surgical correction of varicocele. Zona-free hamster ova were used to determine fertilizing ability. A fertilization rate of less than 10 per cent correlates with infertility. Between May 1978 and November 1979, 75 men with varicocele presenting for fertility evaluation and 23 men with painful varicocele were tested. Of the patients infertile clinically and by in vitro fertilization assay 42 elected ligation of the internal spermatic vein(s). Average fertilization rate of the painful varicocele group was 20.5 per cent and for the infertile group it was 1.2 per cent. Average fertilization rates postoperatively in the infertile group were 2.9 per cent (3 months), 7.7 per cent (6 months), 2.8 per cent (9 months), 7.8 per cent (12 months), 17.5 per cent (15 months) and 8.0 per cent (18 months). Pregnancies occurred only in partners of men whose fertilization rates were between 2.9 and 8.3 per cent preoperatively and who improved to greater than 10 per cent postoperatively. The in vitro fertilization assay may help select those individuals with varicocele and infertility most likely to benefit from varicocele repair.

Fertilization in Vitro↗
PubMed1982

Effect of trypsin inhibitors on acrosome reaction of guinea pig spermatozoa.

Synthetic trypsin inhibitors known to inhibit acrosin were incubated with capacitated guinea pig spermatozoa to determine their possible effects on the membrane vesiculation and acrosomal matrix dispersion steps of the acrosome reaction. As seen by phase-contrast microscopy, the inhibitors nitrophenyl p-guanidinobenzoate, benzamidine and p-aminobenzamidine delayed acrosome reactions induced synchronously in capacitated spermatozoa. Electron microscopy revealed that the membrane vesiculation step of the acrosome reaction was unaffected by treatment of the spermatozoa with trypsin inhibitors, but that dispersion of the acrosomal matrix was blocked in the inhibitor-treated spermatozoa. These results suggest that in the guinea pig, proteinase activity (most likely that of acrosin) is involved in the dispersion of the acrosomal matrix following the membrane vesiculation step of the acrosome reaction, but not in membrane vesiculation.

Acrosin↗
PubMed1980

Inhibition of fertilization in the hamster by sodium aurothiomalate, a hyaluronidase inhibitor.

Sodium aurothiomalate, a low molecular weight inhibitor of hyaluronidase, blocked in-vitro fertilization in hamsters at the level of the zona pellucida: concentrations of 25-250 micrograms inhibitor/ml prevented fertilization of cumulus-intact and cumulus-denuded eggs. Fertilization of zona-free ova was not affected. In-vivo fertilization was also reduced (from 100% controls to 37.5%) by 10 mg inhibitor/ml added to an epididymal sperm suspension before artificial insemination into the uterus. These findings suggest that hyaluronidase may play a role in zona penetration or that sodium aurothiomalate blocks sperm penetration of the zona by inhibiting an enzyme(s) other than hyaluronidase.

Animals↗
PubMed1979

The calcium carbimide-ethanol interaction: effects of ethanol dose.

In a double-blind, placebo-controlled study involving five male alcoholic volunteers, oral administration of 0.7 mg/kg of calcium carbimide (CC) 12 hr before ingestion of ethanol (0.125, 0.25, and 0.5 gm/kg) produced an interaction consisting of increased blood acetaldehyde level, tachycardia, and decreased diastolic blood pressure. The order of intensity of the interaction with regard to ethanol dose was 0.5 greater than 0.25 greater than 0.125 k gm/kg. The subjects were aware of a CC-ethanol interaction only for 0.25 and 0.5 gm/kg of ethanol, for which heart rate was elevated above 100 bpm. With the criterion of heart rate above 100 as indicative of the CC-ethanol interaction, the onset was 0.25 and 0.38 hr for the 0.5 and 0.25 gm/kg ethanol doses and the duration of the interaction was 1.0 and 0.38 hr, respectively. There were positive linear correlations between blood acetaldehyde level and both heart rate and pulse pressure. There was appreciable individual variability in the intensity and duration of the interaction. Pretreatment with CC reduced the rate of ethanol metabolism at the 0.5 gm/kg ethanol dose.

Acetaldehyde↗
PubMed1979

Glucose effect on respiration: possible mechanism for capacitation in guinea pig spermatozoa.

Guinea pig sperm respiration was determined in minimal capacitation medium (MCM) with different energy sources. The ZO2 observed for spermatozoa suspended in media containing pyruvate and lactate was 35.7 +/- 5.9, pyruvate alone, 27.9 +/- 3.8 and D-glucose alone 3.4 +/- 1.1. When D-glucose was added to spermatozoa rapidly respiring in media containing pyruvate as the only exogenous energy source, an immediate suppression in respiration was observed. Further reduction was caused by continued addition of D-glucose. Fructose and mannose also produced a suppression in respiratory rate. However, lactose, fucose, sucrose, L-glucose, and galactose did not alter the respiratory rate. The suppression of respiration by metabolizable sugars is paralleled by a suppression of acrosome reaction in guinea pig spermatozoa. The possibility that suppression of respiration is the mechanism for retardation of capacitation and the subsequent acrosome reaction by D-glucose and other metabolizable sugars is suggested.

Animals↗
PubMed1979

Analysis of human spermatozoal fertilizing ability using zona-free ova.

An in vitro fertilization assay employing zona-free hamster eggs was used to analyze human spermatozoal fertilizing ability. Human spermatozoa were preincubated for 18 to 20 hours in Biggers, Whitten, and Whittingham's medium (1971) at a concentration of 1 X 10(7) sperm/ml prior to the addition of zona-free superovulated hamster eggs. Eggs were examined microscopically 2 hours later for evidence of swelling or decondensing sperm heads in the cytoplasm. A total of 6266 eggs were examined in assays for both suspected fertile and infertile donors; 50 eggs/sample were examined. The percentage fertilization was found to range from 14% to 100% in the suspected fertile group with an average of 56.3%. The sperm concentration in this fertile group ranged from 22 to 303 million/ml with an average of 114. The suspected infertile samples yielded fertilization rates of 10% or less and an average count of 50.6 million/ml. These data suggest that human spermatozoa fuse with the vitelline membrane of zona-free hamster eggs and decondense with varying efficiencies. The percentage of fertilization in this cross-species system did not show a significant correlation with sperm concentration or motility. However, suspected infertile samples always yielded 10% or less fertilization in this assay. This method may have potential value as a diagnostic tool in evaluating human spermatozoal fertilizing capacity which avoids the ethical and logistcal problems associated with fertilization of human eggs in vitro.

Animals↗