Zvi T. Homonnai
Weizmann Institute of Science
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Featured researches published by Zvi T. Homonnai.
Fertility and Sterility | 1978
Zvi T. Homonnai; Haim Matzkin; Nachum Fainman; Gedalia Paz; P. F. Kraicer
The concentrations of calcium, magnesium, and zinc were measured by atomic absorption spectrometry. The concentrations of all three cations were found to be strongly correlated with one another and with acidity (pH). Analysis of the relative concentrations in prostatic fluid, split ejaculates, and whole seminal plasma confirmed an almost exclusively prostatic origin of these cations. Semen quality, as judged by motility, vitality, concentration, and morphology of spermatozoa, was inversely related to cation concentrations. Therefore, we recommend adoption of the measurement of seminal divalent cations as part of the routine andrologic examination.
Fertility and Sterility | 1979
Menachem P. David; Ami Amit; Arie Bergman; Gideon Yedwab; Gedalia Paz; Zvi T. Homonnai
A nonlinear regression analysis was used in order to fit a logistic model to 200 runs of human ejaculated spermatozoa penetrating cervical mucus of good quality. The data revealed excellent correlation between the number of sperm penetrating (sigma penetration, SP) and the motility (r = 0.776) and vitality (r = 0.534) of the spermatozoa. The percentage of abnormal spermatozoa found in the ejaculate was negatively correlated (r = -0.649), while sperm concentration showed a poor correlation with SP (r = 0.327). Furthermore, concentration was shown to have no effect in samples containing over 5 million sperm/ml. The conclusion of this study is that the two major parameters of sperm quality determining the capacity of spermatozoa to penetrate cervical mucus are motility and the presence of normal forms of spermatozoa.
Fertility and Sterility | 1977
Gedalia Paz; Zvi T. Homonnai; Daniel Ayalon; Tova Cordova; P. F. Kraicer
Concentrations of immunoreactive insulin (IRI) and, in some cases, testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured in serum and seminal plasma (SP). IRI levels were usually higher in SP. They were unaffected by masturbation; circulating testosterone, LH, and FSH levels were also unaffected. The IRI concentration was higher in the second (vesicular) fraction of split ejaculates. Semen quality was unrelated to IRI in SP in normal and diabetic (chlorpropamide-maintained) men. The addition of insulin in vitro to washed spermatozoa from diabetic and nondiabetic men had no effect on oxygen and glucose uptake or on lactate production and spermatozoal motility. Furthermore, administration of L-arginine to infertile men for 3 months (4 gm/day) was followed in four of seven men by significant increases in IRI concentrations in blood and SP. However, neither semen quality nor fertility was improved.
Fertility and Sterility | 1992
Leah Yogev; Haim Yavetz; Zvi T. Homonnai; Yehuda Hiss; Gedalia Paz
This study evaluated the impact of sperm cryopreservation on sperm quality. The HZA was used to test the binding capacity of fresh as opposed to frozen-thawed sperm from 12 donors. Fresh and frozen-thawed sperm motility was 47% +/- 1.5% and 24% +/- 3.8% (mean +/- SE), respectively. However, the number of sperm cells attached to the hemizonae was 75 +/- 12.0 and 74 +/- 11.9, respectively. We conclude that cryopreservation results in a reduced number of motile sperm cells but does not adversely affect the ability of rescued sperm cells to bind to the ZP. The study also supports the use of frozen-thawed rather than fresh donor sperm for control in the HZA procedure.
Contraception | 1975
Zvi T. Homonnai; Gedalia Paz; Adin Sofer; Gideon A. Yedwab; Perez F. Kraicer
Abstract Human spermatozoa were incubated in vitro in the presence of α-chlorohydrin at concentrations which inhibited motility, but which were not spermicidal. The inhibition of motility was not reversed by washing or by addition of α-glycerophosphate. Metabolic activity of the spermatozoa was reduced, as measured by glucose, oxygen uptake and lactate production. Endogenous respiration was not affected. Cyclic AMP levels were reduced. Thus, at least part of the adversed effects of α-chlorohydrin on male fertility may be due to direct inhibitory action on the spermatozoa.
The Journal of Urology | 1990
Stephen A. Berger; Haim Yavetz; Gedalia Paz; Alfred Gorea; Zvi T. Homonnai
A single oral dose of ofloxacin (400 mg.) or ciprofloxacin (500 mg.) was administered to each of 40 men. The mean concentrations of ofloxacin in semen exceeded those of ciprofloxacin at 1 hour (p = 0.035) and 24 hours (p = 0.028), while the levels of the 2 drugs at 2 and 4 hours were comparable. Semen concentrations of ofloxacin but not ciprofloxacin exceeded the reported minimal inhibitory concentration of Enterobacteriaceae, Chlamydia trachomatis and genital Mycoplasma species 24 hours after dosage.
Fertility and Sterility | 1990
Haim Matzkin; Zvi T. Homonnai; Dalia Galiani; Gedalia Paz; Nava Dekel
Serum follicle-stimulating hormone (FSH) levels measured by radioimmunoassay (RIA) usually correlate well with the rate of spermatogenesis. However, in certain cases this correlation does not exist. The purpose of this study was to establish a reliable bioassay of FSH for the andrological clinic. Follicle-stimulating hormone was measured by both standard RIA and bioassay in 98 men subgrouped into normospermic, Oligospermic, and azoospermic. Bioactivity of FSH was determined using in vitro cultures of granulosa cells utilizing progesterone measurements for assessing FSH activity. Results of FSH levels obtained by both methods correlated well ( r = 0.55, P
Acta Diabetologica | 1980
Gedalia Paz; Nachum Drasnin; Zvi T. Homonnai
SummaryDiabetes was induced in rats by i.v. injection of streptozotocin (60 mg/kg body weight). Diabetes was accompanied by infertility and atrophy of the male accessory glands. Blood glucose rose above 500 mg% (post-prandial) and blood testosterone decreased to 14% of the level found in normoglycemic rats. Diabetes was followed by increased levels of sorbitol in the male accessory glands, prostate, seminal vesicle and coagulating gland, and in the eyes and sciatic nerves. Insulin treatment of the diabetic rats prevented sorbitol accumulation in the above tissues. A Y-22, 284, an inhibitor of aldose reductase given in the food (1 g/kg body weight/day) for 3 weeks, did not prevent sorbitol accumulation in the organs mentioned. The changes in sorbitol metabolism in the diabetic rat and their possible involvement in male fertility are discussed.
Fertility and Sterility | 1994
Haim Yavetz; Dov Lichtenberg; Gedalia Paz; Zvi T. Homonnai; Leah Yogev
OBJECTIVE To evaluate the effects of Tes and Tris (TEST)-yolk buffer (TYB) incubation on sperm function. DESIGN Sperm samples obtained from 61 patients attending the infertility clinic were incubated in TYB and control medium. Binding to the zona pellucida (ZP), evaluated by the hemizona assay, membrane functional integrity evaluated by the hypoosmotic swelling test, and acrosome reaction and penetration through cervical mucus were assessed to ascertain the effect of TYB treatment. RESULTS The only substantial effect of TYB treatment was enhanced sperm binding to the ZP. The mean number of sperm cells attached to the hemizonae with TYB or medium treatment, was 42 +/- 6.1 (+/- SE) and 31 +/- 5.8, respectively (n = 61). However, this improvement was most obvious in 12 patients whose sperm samples exhibited a marked increase in sperm binding capacity following TYB treatment compared to medium without TYB, 71 +/- 5.6 and 12 +/- 2.7, respectively. In the other sperm samples (n = 49), sperm binding capacity was similar following TYB and medium treatment (both 35 +/- 6.0). CONCLUSIONS A 2-hour incubation of sperm samples with TYB-containing medium (at room temperature) enhances the binding capacity of human spermatozoa in approximately 20% of patients considered to have male factor infertility. The basis of this selective effect has yet to be studied further.
International Journal of Gynecology & Obstetrics | 1990
Haim Matzkin; Zvi T. Homonnai; Dalia Galiani; Gedalia Paz; Nava Dekel
Serum follicle-stimulating hormone (FSH) levels measured by radioimmunoassay (RIA) usually correlate well with the rate of spermatogenesis. However, in certain cases this correlation does not exist. The purpose of this study was to establish a reliable bioassay of FSH for the andrological clinic. Follicle-stimulating hormone was measured by both standard RIA and bioassay in 98 men subgrouped into normospermic, oligospermic, and azoospermic. Bioactivity of FSH was determined using in vitro cultures of granulosa cells utilizing progesterone measurements for assessing FSH activity. Results of FSH levels obtained by both methods correlated well (r = 0.55, P less than 0.01) within themselves, and both correlated negatively and significantly with sperm concentration. The ratio between bioactivity and immunoreactivity of FSH did not correlate with sperm density. Thus, the decrease in sperm concentration and other sperm variables resulting from a germinal epithelial dysfunction was not mediated or associated with low biological activity of FSH. The application of this method can be of clinical value in cases where a discrepancy is found between serum RIA-FSH levels and sperm quality.