PubMed Health⌕ Search

Biomedical subjects

R Weissenberg

Publications and source records attributed to R Weissenberg.

At least 37 records · Page 2Linked to original sources
PubMed1987

Immunosuppressant material in human seminal fluid. Inhibition of blast transformation and of NK activity by seminal fluid patients of a male infertility clinic.

Human seminal plasma from normal or patients with abnormal parameters of the ejaculates contains an inhibitory material that expresses potent in vitro inhibitory activity on PHA-M-induced blast transformation and NK activity. Using the test of inhibition of NK activity, the semen samples from individuals with higher concentrations of fructose had higher inhibitory activity. The results described herein suggest that inhibitory activity for blast transformation may be present in the prostatic fluid while the NK inhibition aspects are correlated with the vesicle-marker (fructose). Inhibition of the immune responses by human seminal plasma of the effector functions indicates the interesting implication that soluble factors may indirectly protect against or promote human autoimmune infertility disease.

Humans↗
PubMed1987

Effect of testicular torsion on contralateral testis and fertility in mature rats.

The effect of unilateral testicular torsion on the contralateral testis and the fertility rate was studied in Charles River adult rats. Animals were divided into groups that underwent a sham operation or torsion and ligation of the left testicular vessels followed by orchiectomy after 24 h, orchiectomy after 48 h, release of the ligature after 24 h, release of the ligature after 48 h, and no further treatment following ligation. Another group of animals underwent unilateral orchiectomy. After 8 weeks animals were allowed to mate and were sacrificed 2 weeks later. The results did not point to either histological alterations in the contralateral testis or impairment of fertility in any group of treatment compared with the control.

Animals↗
PubMed1987

ATP content in human semen and sperm quality.

Five semen characteristics (count, motility, normal forms, bovine cervical mucus penetration, and ATP) were evaluated in patients attending the infertility clinic. Multiple regression analysis indicated that the only characteristic independently affecting ATP concentration was sperm count, whereas motility and percent normal forms had no additional contribution to ATP level. Penetration into bovine cervical mucus did not depend on ATP levels. Comparison of semen characteristics in the same group between patients who have impregnated their wives and those who have not indicated that with respect to count, motility, morphology, and ATP the only sperm characteristic independently predicting fertility was motility. ATP measurements have limited value in the evaluation of semen quality.

Adenosine Triphosphate↗
PubMed1987

Effect of washing and suspension on penetration of human sperm into bovine cervical mucus.

The in vitro penetration ability of human sperm into bovine cervical mucus after washing and suspension of the sperm in Earl's medium was compared with that of untreated sperm. The extent of penetration was found to be significantly lower in sperm washed and suspended in Earl's medium than in the unwashed sperm (p less than 0.0001); it increased to some extent on resuspension of the washed sperm in the seminal plasma but still remained significantly lower than that of intact sperm (p less than 0.009). The introduction of caffeine into the Earl's medium resulted in an increased penetration of the washed sperm into bovine cervical mucus, but this was still significantly lower than the penetration of the unwashed sample (p less than 0.02). The data point to the effectiveness of the seminal plasma as a medium facilitating sperm penetration through bovine cervical mucus.

Animals↗
PubMed1986

Influence of various substrates on the acetylcarnitine:carnitine ratio in motile and immotile human spermatozoa.

Human spermatozoa were incubated in albumin-containing Hepes-buffered modified Ringer's solution, in the presence or absence of externally supplied substrates. The acylated forms of carnitine were identified by bioautography. Incubation of the cells with propionate or n-valerate resulted in increased content of propionylcarnitine, but n-butyrate, isobutyrate, n-valerate, isovalerate, hexanoate or heptanoate did not result in the appearance of acylcarnitine of chain length C4-C7. The addition of methionine, valine or isoleucine (whose catabolic pathways should produce propionyl-CoA) to the incubation medium did not increase propionylcarnitine. In all cases acetylcarnitine was the major acylcarnitine in human spermatozoa. The ratio of acetylcarnitine:carnitine remained relatively constant in spermatozoa incubated without external substrate for up to 4 h. No significant change in the ratio was observed when glucose, fructose or citrate were present in the incubation medium. Sorbitol decreased the ratio slightly and aspartic acid slightly increased it. A more pronounced increase in the ratio was caused by lactate or pyruvate. This increase was observed in motile spermatozoa but not in samples from asthenospermic men, indicating that metabolic utilization of pyruvate and lactate may differ in motile and immotile cells.

Acetylcarnitine↗
PubMed1985

Phosphorus-31 and proton NMR analysis of reproductive organs of male rats.

Phorphorus NMR spectra of the whole reproductive organs of male rats and their perchloric acid extracts indicate the presence of phosphocholine and phosphoethanolamine in the testis, glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE) in the epididymis, and creatine phosphate, GPC, and GPE in the seminal vesicles. High amounts of carnitine and inositol were observed by the proton NMR of perchloric acid extract of the corpus and cauda epididymis. Smaller amounts of these compounds were observed in the caput epididymis and vas deferens; they were totally absent in the testis. Creatine is present in high concentrations in the testis, vas deferens, and seminal vesicles. It is almost absent in all parts of the epididymis.

Animals↗
PubMed1984

The diagnostic value of sperm in post-ejaculatory urine.

Post-ejaculatory urine samples ( PEUS ) were obtained from patients undergoing semen analysis. The samples were examined for the presence, number and morphology of sperm. Spermatozoa were found in PEUS of 84.8% of 171 patients whose semen contained sperm. The presence of sperm after, but not before, ejaculation and their concentration in the first part of the void indicated the spermaturia to be the result of urethral washing after ejaculation. The number of sperm in PEUS was a small and variable fraction of the ejaculated sperm. A significant positive correlation was found between the PEUS and the semen sperm count, but there was a considerable overlap of PEUS counts between oligospermic and normospermic individuals. The percentage of sperm with normal morphology in PEUS reflected that in semen. It is concluded that although PEUS reflects some of the semen characteristics, a single PEUS cannot serve as a precise substitute for a direct semen analysis in the individual patient. It can, however, be used for establishing whether populations exposed to dangerous ecological conditions or to drugs which are known to adversely affect spermatogenesis, have reduced sperm count by comparison to appropriate control groups.

Ejaculation↗
PubMed1984

Evaluation of the morphology of sperm in urine of adolescent boys.

The morphology of spermatozoa in the first morning void of boys aged 12-16 years was evaluated. The results suggest that the number of cells having normal morphology increases with advancing age. Thus, the percentage of boys with greater than 45% normal sperm was 26% at the age of 12-13, increasing to 51% at the age of 15-16.

Adolescent↗
PubMed1984

Carnitine and acetylcarnitine in motile and immotile human spermatozoa.

Human sperm were found to contain acetylcarnitine, carnitine, and only traces of propionylcarnitine and four-carbon acylcarnitines. Carnitine and acetylcarnitine were present in higher concentrations in sperm than in the corresponding seminal fluid samples, and the degree of acylation of carnitine was greater in sperm than in seminal plasma. The ratio of acetylcarnitine/carnitine was 1.77 +/- 0.69 in extracts of sperm from samples with a low degree of motility (0-10% motile), whereas it was 4.70 +/- 1.58 in samples which were 40-80% motile. The possible significance of this difference with regard to the degree of acylation of coenzyme A is discussed.

Acetylcarnitine↗
PubMed1983

Carnitine and short-chain acylcarnitines in the lumen of the human male reproductive tract.

Bioautography of human semen demonstrated the presence of L-carnitine, acetylcarnitine, propionylcarnitine and C4-acylcarnitines (butyrylcarnitines). In studies designed to ascertain the organs secreting these compounds into semen it was found that: Quantitative analyses of semen obtained pre- and post-vasectomy showed markedly decreased L-carnitine concentrations, slightly decreased acetylcarnitine levels, and unchanged propionyl- and butyrylcarnitine concentrations as a result of vasectomy. The earlier portion of human split ejaculate samples characteristically contained higher concentrations of carnitine and its propionyl- and butyryl esters and a lower concentration of acetylcarnitine than did the later portion. Vas deferens luminal fluid contained carnitine and each of the short-chain acyl derivatives, as shown by bioautography. Prostatic fluid contained only small amounts of carnitine and its derivatives. Spermatozoa contained much more acetylcarnitine than free carnitine, and only trace amounts of the other acylcarnitines. It is concluded that carnitine in semen is secreted primarily by the epididymis, that a proportion of the acetylcarnitine derives from the seminal vesicles and epididymis, and that propionylcarnitine and butytylcarnitine enter semen, at least in part, together with the vas deferens contents.

Adult↗
PubMed1983

Inability of round acrosomeless human spermatozoa to penetrate zona-free hamster ova.

The spermatozoa from five healthy men of proved fertility and five infertile men with a single abnormal semen parameter associated with high proportion of round acrosomeless heads were evaluated for their ability to bind to and to penetrate zona-free hamster ova. Sperm from five men of proved fertility penetrated a high proportion of the eggs (16-80%) while sperm from men of the infertile group failed to bind and to penetrate any of the ova. Round acrosomeless sperm do not have the ability to bind to or to fuse with the vitellus of zona-free hamster eggs.

Acrosome↗
PubMed1982

The role of sperm-bound hyaluronidase in the dispersal of the cumulus oophorus surrounding rat ova.

Only a very small portion (4-7%) of the hyaluronidase of rat sperm obtained from the caput or cauda epididymis was related during incubation in capacitation medium for up to 24 h at 37 degree C. A portion of the cell-associated hyaluronidase was accessible to external substrates, allowing sperm suspensions to lyse glycosaminoglycans of cumulus clots rapidly, even without capacitation. This process appears to represent the employment of an enzyme bound to the sperm cell, analogous to the use of solid-phase enzymes in current enzyme technology.

Animals↗
PubMed1982

Hormonal dependence of the first spermatogenic wave in the mouse.

Antiserum to rat gonadotropins (arG) has been proved capable of binding homologous luteinizing hormone (LH) and follicle stimulating hormone (FSH) in vitro and mouse LH and FSH in vivo. The administration of arG did not evoke antibody production. The physiological role of endogenous gonadotrophins during neonatal life was studied by administration of this antiserum to groups of newborn male mice. Daily injection of arG from birth up to the age of 100 days inhibited markedly weight increase of testes and accessory glands. Histological evaluation of the testes of such treated animals revealed that spermatogenesis up to the stage of pachytene spermatocytes can proceed in the absence of endogenous gonadotropins; however, no spermatids were formed and the number of cells that developed in the hormone-deprived animals was significantly lower than in the normal animal. Substitution treatment with exogenous FSH permitted the formation of a small number of spermatids, but completion of spermatogenesis was obtained only with combined LH and FSH treatment.

Animals↗
PubMed1981

Carnitine and acylcarnitines in semen from azoospermic patients.

Carnitine and its short-chain acyl esters were assayed in semen from normospermic and azoospermic men. Extremely low concentrations of free carnitine and acylcarnitine were found in semen from patients with obstructive azoospermia where the ejaculate was primarily of prostatis origin, and low values were also obtained in obstruction of the vas deferens, where the epididymal contents were not ejaculated. Semen from patients whose azoospermia was caused by testicular dysfunction had low acylcarnitine concentrations and normal levels of free carnitine in most cases, but a group of patients with severe testicular failure (including cases of Klinefelter syndrome and cryptorchidism) had low semen free carnitine concentrations. Whereas treatment with human chorionic gonadotropin increased serum testosterone levels in azoospermic patients, it did not increase the free carnitine concentration in semen, although it increased the proportion of carnitine found in acylcarnitines.

Acetylcarnitine↗
PubMed1980

Morphological characterization of abnormal human spermatozoa using transmission electron microscopy.

A morphological analysis of ejaculated human abnormal spermatozoa is presented. Eighteen different malformations are characterized, based on (a) the cell's organelle where they appeared, (b) the possible developmental stage when they occurred, and (c) the possible mechanism responsible for a specific appearance. The forces that govern the shaping of the spermatozoan head are described in detail. The possible mechanism responsible for chromatin subcondensation, acrosome malformation, kinked tail forms, and mitochondrial malformations are discussed.

Acrosome↗
PubMed1980

Studies on polyspermia.

Thirty-one couples in whom the only apparent abnormality was polyspermia in the male partner were studied in light of a suggested new definition of polyspermia. The rate of infertility was 22.5% versus 17.6% in a control group of couples with no apparent abnormalities; the difference was not statistically significant. The spontaneous abortion rate was 25.5% versus 9.7% in the controls (P less than 0.05). Semen analysis of the men showed signifcantly low fructose levels and high percentages of necrospermia and agglutination compared to controls. Various hypotheses for the etiology of polyspermia are discussed.

Fructose↗
PubMed1979

Differences in concanavalin A-FITC binding to rat spermatozoa during epididymal maturation and capacitation.

Rat spermatozoa from the caput epididymis and cauda epididymis, but not from the testis, demonstrated a crescent of greenish fluorescence on the convex surface of the sperm head, as observed by fluorescence microscopy after staining with concanavalin A-fluorescein isothiocyanate. The percentage of spermatozoa displaying this fluorescent zone decreased during incubation under capacitating conditions, both in vivo and in vitro, suggesting that a glycoprotein zone that is capable of binding concanavalin A was removed or altered during the capacitation period.

Animals↗