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Biomedical subjects

I Tur-Kaspa

Publications and source records attributed to I Tur-Kaspa.

At least 19 recordsLinked to original sources
PubMed1996

High levels of soluble p55-TNF receptors in seminal and prostatic fluids of normal and infertile men.

PURPOSE: To study the role of tumor necrosis factor (TNF) in the male reproductive systems by examining the occurrence, source, and possible functional significance of soluble TNF receptors in seminal fluids of normal and infertile men. MATERIALS AND METHODS: Concentrations of soluble TNF receptors (p55-sTNF-R and p75-sTNF-R) were measured by ELISA in human sera, seminal fluids, prostatic fluid and fluid obtained from an epididymal spermatocele. RESULTS: The level of p55-sTNF-R in seminal fluids of normospermic men was approximately equal to 20-fold higher than in normal serum (13.9 +/- 6.9 ng./ml. versus 0.7 +/- 0.2 ng./ml.). In contrast, p75-sTNF-R, which occurs in serum at amounts higher than p55-sTNF-R, was almost indiscernible in the seminal fluids (<0.18 +/- 0.28 ng./ml. versus 1.9 +/- 0.6 ng./ml. in sera). Concentrations of p55-sTNF-R in seminal fluids of oligoasthenospermic and azoospermic men were similar to those of normospermic men (15.6 +/- 8.5 ng./ml. and 14.9 +/- 6.5 ng./ml., respectively). Higher p55-sTNF-R concentrations were found in prostatic fluids and first split ejaculates (39.8 +/- 1.2 ng./ml. and 32 +/- 1.7 ng./ml., respectively), while second split ejaculates and the fluid from an epididymal spermatocele were found to contain p55-sTNF-R at lower levels (10.8 +/- 1 ng./ml. and 1 ng./ml., respectively). CONCLUSIONS: These findings suggest intense local biosynthesis of p55-sTNF-R in the prostate occurring independently of spermatogenesis. Possible functional implications are: 1) shielding of spermatozoa from the inhibitory effect of TNF in the female reproductive tract; 2) a role for TNF in the normal physiology of the prostate; and 3) blocking TNF-mediated immune response in the prostate, which may have bearings on the development of prostatic hypertrophy or cancer.

Antigens, CD↗
PubMed1995

Sperm capacitation in humans is transient and correlates with chemotactic responsiveness to follicular factors.

In humans, only a small fraction (2-12%) of a sperm population can respond by chemoattraction to follicular factors. This recent finding led to the hypothesis that chemotaxis provides a mechanism for selective recruitment of functionally mature spermatozoa (i.e., of capacitated spermatozoa, which possess the potential to undergo the acrosome reaction and fertilize the egg). This study aimed to examine this possibility. Capacitated spermatozoa were identified by their ability to undergo the acrosome reaction upon stimulation with phorbol 12-myristate 13-acetate. Under capacitating conditions, only a small portion (2-14%) of the spermatozoa were found to be capacitated. The spermatozoa were then separated according to their chemotactic activity, which resulted in a subpopulation enriched with chemotactically responsive spermatozoa and a subpopulation depleted of such spermatozoa. The level of capacitated spermatozoa in the former was approximately 13-fold higher than that in the latter. The capacitated state was temporary (50 min < life span < 240 min), and it was synchronous with the chemotactic activity. A continuous process of replacement of capacitated/chemotactic spermatozoa within a sperm population was observed. Spermatozoa that had stopped being capacitated did not become capacitated again, which indicates that the capacitated state is acquired only once in a sperm's lifetime. A total sperm population depleted of capacitated spermatozoa stopped being chemotactic. When capacitated spermatozoa reappeared, chemotactic activity was restored. These observations suggest that spermatozoa acquire their chemotactic responsiveness as part of the capacitation process and lose this responsiveness when the capacitated state is terminated. We suggest that the role of sperm chemotaxis in sperm-egg interaction in vivo may indeed be selective recruitment of capacitated spermatozoa for fertilizing the egg.

Acrosome↗
PubMed1995

[Plague].

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Humans↗
PubMed1994

How often should infertile men have intercourse to achieve conception?

OBJECTIVE: To clarify how often infertile men should have intercourse to achieve conception, the effect of sequential ejaculation on total motile sperm counts was investigated. DESIGN: Case-control study. SETTING: Infertility and IVF unit, tertiary care center. PARTICIPANTS: Five hundred seventy-six men who produced two closely spaced sequential ejaculates. MAIN OUTCOME MEASURE: The total motile sperm counts of the second ejaculates were compared with the total motile sperm counts of the first ejaculates. RESULTS: In normospermic men (n = 359), the total motile sperm counts decreased significantly from 93 (18 to 601) (median [minimum to maximum] x 10(6)) in the first ejaculate to 42 (1.2 to 387) in the second ejaculate, produced 24 hours later. In contrast to the normospermic men, in the asthenospermic group (24 hours difference, n = 81) and in both oligospermic groups, (1 to 4 hours difference, n = 27; and 24 hours difference, n = 45), there were no significant changes in the total motile sperm counts (24 [5.9 to 229] versus 30 [0.8 to 150], 6 [0.8 to 18] versus 3.6 [0.1 to 63] and 13 [2.5 to 32] versus 10 [0.1 to 66], respectively). Moreover, in both oligoasthenospermic groups (1 to 4 hours difference, n = 23; and 24 hours difference, n = 41) the total motile sperm counts increased significantly (3.2 [0.6 to 7.9] versus 8 [0.4 to 48] and 4 [0.2 to 13] versus 4 [0.1 to 101], respectively). In all groups, pooling sequential ejaculates significantly increased the total motile sperm counts, over and above that of the first ejaculate, by 49% in the normospermic group, 95% in the asthenospermic group, 67% and 75% in the oligospermic groups (1 to 4 hours and 24 hours difference, respectively), and 233% and 139% in the oligoasthenospermic groups (1 to 4 hours and 24 hours difference, respectively). CONCLUSIONS: Sequential ejaculation may overcome the impaired sperm transport causing low total motile sperm counts observed in some oligospermic and/or asthenospermic men. Most of these infertile men may significantly increase their fertility potential, assessed by the total motile sperm counts, either by pooling sequential ejaculates for IUI, GIFT, and IVF, or by having intercourse every day or even twice a day, at the time of ovulation.

Case-Control Studies↗
PubMed1994

Salpingectomy by operative laparoscopy and subsequent reproductive performance.

Between January 1984 and August 1991, 511 cases of extrauterine pregnancies were diagnosed by laparoscopy in our department. In 374 cases salpingectomy was performed: 184 by explorative laparotomy, and 190 by operative laparoscopy. Patients were scheduled for salpingectomy if one or more of the following criteria were fulfilled: (i) a ruptured tube which was surgically unsuitable for conservation; (ii) no interest in future fertility; (iii) tubes with ectopic gestation previously operated on; (iv) a previous tubal pregnancy on the same side, which was treated expectantly. Salpingectomy was performed via operative laparoscopy with bipolar diathermy forceps and laparoscopic scissors. Pregnancy rates, i.e. intra-uterine and repeat extra-uterine, were evaluated. The reproductive performance following salpingectomy did not differ significantly, whether by laparotomy or laparoscopy: the intra-uterine pregnancy rate was 78 and 64%, respectively and the repeat ectopic pregnancy rate was 12 and 6%, respectively. Salpingectomy via laparoscopy can be performed safely with a low incidence of complications, with subsequent reproductive performance comparable to laparotomy.

Adult↗
PubMed1994

Chemotaxis and chemokinesis of human spermatozoa to follicular factors.

Human spermatozoa accumulate in vitro in diluted follicular fluids obtained from follicles from which the eggs have been fertilized. Using capillary assays under a variety of experimental conditions (ascending or descending gradients of follicular fluid, or no gradient at all) and microscopic assays in which individual spermatozoa could be followed, we found that the sperm accumulation in follicular fluid was the result of both sperm chemotaxis and chemokinesis and eventually hyperactivation-like motility. We determined the optimal conditions for sperm accumulation, which involved sperm preincubation (possibly to induce sperm capacitation) and proper dilution of follicular fluid. In all the assays, the net accumulation was low, probably reflecting the chemotactic responsiveness of only a small fraction of the sperm population at any given time. We partially fractionated follicular fluid in a Centricon microconcentrator (Amicon, Danvers, MA) and by acetone precipitation, and found that at least one of the chemotactic factors is a small (< 10-kDa) molecule that is probably nonhydrophobic. This is the first time that sperm chemotaxis and chemokinesis in response to a follicular factor(s) in mammals has been established and has been distinguished from other processes that might cause sperm accumulation. The physiological significance of these findings is discussed.

Capillary Action↗
PubMed1994

Sequential acquisition of chemotactic responsiveness by human spermatozoa.

Recent studies have indicated that human spermatozoa respond to follicular fluid by attraction to chemotactic factor(s) in the fluid, accompanied by enhancement of motility and ultimately hyperactivation. In this study, we quantified the sperm response. We exposed spermatozoa to a gradient of a chemotactically active fraction of follicular fluid (denoted as "the attractant") and separated the spermatozoa that accumulated in the attractant and those that did not. We thus obtained two subpopulations: one enriched with chemotactically responsive spermatozoa, and one deficient in such spermatozoa. The fraction of the responsive spermatozoa out of the total sperm population was 2-12% at any measured time point. With time, the responsive spermatozoa lost their ability to be attracted, while such activity was gradually acquired by the subpopulation originally deficient in responsive spermatozoa. These results indicate that the identity of responsive spermatozoa is continuously changing. If the in vitro results are representative of the physiological conditions in vivo, they imply that the role of sperm chemotaxis combined with enhanced motility may be to select capacitated spermatozoa and bring them to the egg. Such a mechanism may, over an extended period of time, increase the prospect that an egg will meet capacitated spermatozoa as soon as it ovulates.

Cell Separation↗
PubMed1993

The multicentre transcervical balloon tuboplasty study: conclusions and comparison to alternative technologies.

Transvaginal tubal catheterization procedures have been suggested as an alternative to microsurgery and in-vitro fertilization (IVF) in the treatment of women with proximal tubal occlusion. A transcervical balloon tuboplasty (TBT) catheter was specifically developed and tested in a prospective multicentre trial. A total of 151 women with confirmed bilateral or unilateral tubal occlusion were studied. The primary study population included 106 women who, after exclusion of patients for protocol violations, represented those females who were treated for complete tubal occlusion with TBT. TBT is an ambulatory, minimally invasive catheter procedure, performed under paracervical block or mild sedation, which utilizes a co-axial balloon catheter under fluoroscopic guidance. Re-canalization, pregnancy and reocclusion rates following the procedure were documented. A total of 28 patients demonstrating uni- or bilateral tubal patency after either hysterosalpingography and/or selective salpingography represented the control population. TBT established tubal patency of at least one Fallopian tube in 95/106 patients (90%) and in 167/205 obstructed oviducts (82%). Clinical pregnancies occurred in 37/106 females (35%), with a life table adjusted rate of 37%. Patients without distal disease had significantly higher pregnancy rates than those with bipolar tubal disease (49% versus 12%, life table adjusted rate; P = 0.0002) but pregnancy rates were independent of underlying aetiology for tubal disease. Pregnancy rates in control patients who did not reach TBT because of tubal patency after hysterosalpingography and/or selective salpingography were significantly lower than in those successful treated with TBT (P = 0.027), and occurred only for four cycles after hysterosalpingography and with approximately a 1 year delay after selective salpingography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Sonographic transcervical balloon tuboplasty.

The purpose of this study was to evaluate sonographic guidance for transcervical tubal catheterization and transcervical balloon tuboplasty of patients with bilateral proximal tubal occlusion. Cornual catheterization and transcervical balloon tuboplasty were performed under sonographic guidance. Injection of micro-bubble emulsion confirmed tubal recanalization. Tubal patency demonstrated by sonography was confirmed by injection of contrast material under fluoroscopy. Four women with bilateral proximal tubal occlusion confirmed by previous hysterosalpingogram and laparoscopy underwent sonographically guided transcervical balloon tuboplasty. Patients with distal or peritubal damage were excluded from this study. Bilateral tubal patency confirmed by sonography and subsequent fluoroscopy was achieved in all four patients. One patient conceived spontaneously, a month following the procedure, and delivered at term. Sonographically guided transcervical balloon tuboplasty can be performed successfully on patients with proximal tubal occlusion. Identification of the catheter tip and successful cannulation of the internal tubal ostia were easier to perform under fluoroscopy. Further improvements in sonographic equipment and catheter technology will hopefully eliminate radiation and replace fluoroscopy during the performance of transcervical balloon tuboplasty. Sonographic transcervical tubal catheterization may, therefore, become a simple and cost-effective procedure for the diagnosis and treatment of patients with proximal tubal occlusion.

Evaluation Studies as Topic↗
PubMed1991

Hyponatremia induced by exercise: a 24-hour endurance march study.

In our previous studies on the relationship between prolonged physical stress and muscle enzyme activities, a number of individuals suffered a hyponatremic state. The present study was conducted to evaluate the effect of prolonged physical stress on the development of hyponatremia. Seventeen physically fit male subjects were studied during a 24-hour endurance march. Serum sodium, that averaged 142 +/- 2 before the march, decreased during the march to 135 +/- 2 mEq/l (p less than 0.01 versus before the march). Blood and plasma volumes increased by 8 and 16% (p less than 0.05), respectively. Creatinine clearance before the march declined from 118 +/- 24 to 74 +/- 19 ml/min (p less than 0.005) during the march and correlated negatively with serum sodium (p less than 0.002; r = 0.59). Urinary sodium excretion before the march was 132 +/- 55 and during the march was 123 +/- 62 mEq/24 h. Free water clearance rose during the march and correlated negatively with serum sodium (p less than 0.001), suggesting an appropriate renal diluting response. However, the fall in serum sodium correlated positively with water intake (p less than 0.01; r = 0.59). These results show that hyponatremia develops during endurance marching in normal subjects on an unrestricted high water intake. The renal response to water intake is appropriate; however, the subjects fall to produce maximally diluted urine. Therefore, we suggest that water intake should follow physiological needs and not forced to cause hyponatremia during prolonged physical stress.

Adult↗
PubMed1990

Ovarian stimulation protocol for in vitro fertilization with gonadotropin-releasing hormone agonist widens the implantation window.

Pregnancy rates vary considerably with the type of ovarian stimulation used for in vitro fertilization and embryo transfer (IVF-ET). The window of implantation may represent one of the rate-limiting steps in IVF success. We therefore investigated estimated implantation times of 10 consecutive IVF singleton pregnancies, achieved using pituitary suppression with gonadotropin-releasing hormone agonist (GnRH-a) before and during ovarian stimulation with human menopausal gonadotropins (hMG), and compared those with 9 consecutive IVF pregnancies achieved by hMG stimulation only. Estimated implantation times were calculated by regression analysis of serial human chorionic gonadotropin (hCG) measurements between days 7 and 16 after ET. The GnRH-a/hMG pregnancies implanted between days 7 and 11, whereas hMG pregnancies implanted between days 7 and 9 after ET. The hCG regression curve for the GnRH-a/hMG pregnancies revealed a delay of 1.5 days in estimated implantation time compared with the hMG only group. There were no significant differences in pretransfer in vitro embryos development between the two groups. Thus, the delay in hCG rise probably reflects a delay in embryo implantation. We therefore conclude that a GnRH-a/hMG stimulation protocol appears to widen the implantation window in comparison with a hMG only protocol. This observation may at least in part explain the improved IVF pregnancy success with GnRH-a/hMG stimulation protocols.

Chorionic Gonadotropin↗
PubMed1990

Pooled sequential ejaculates: a way to increase the total number of motile sperm from oligozoospermic men.

We investigated the yield of total number of motile spermatozoa from oligozoospermic men by pooling two closely spaced sequential ejaculates. Semen characteristics were compared between sequential ejaculates (within a period of 1 to 4 hours) of 18 oligozoospermic males (sperm concentration less than 20 X 10(6)/mL and total sperm count less than 40 X 10(6) in the ejaculate) and a control group of 16 normozoospermic men. Whereas the median total number of motile sperm of normozoospermic males significantly decreased from 70 X 10(6) in the first ejaculate to 23 X 10(6) in the second sequential ejaculate, such a decrease was not detected in oligozoospermic males, 3.6 X 10(6) and 3.1 X 10(6), respectively. The percent of normozoospermic and oligozoospermic men who demonstrated a decreased (less than 50%), a comparable (50% to 150%), or an increased (greater than 150%) total motile sperm count in the second ejaculate in comparison with the first ejaculate were 69%, 31%, and 0 versus 39%, 28%, and 33%, respectively. Consequently, pooling of two sequential ejaculates significantly increased the median total number of motile sperm from normozoospermic males by 144% and from oligozoospermic males by 329%, (to 10.2 X 10(6]. We suggest that pooling of two sequential ejaculates from oligozoospermic males is a simple and cost effective method to increase significantly the total number of motile sperm for intrauterine insemination, in vitro fertilization, gamete intrafallopian transfer, or semen cryopreservation.

Body Fluids↗
PubMed1989

The role of gonadotropins in the etiology of ectopic pregnancy.

Our study indicates that the high rate of EP in MAP(+) patients, treated with hMG/hCG, is due to the fact that it is a selected group of infertile patients with probable additional underlying tubal disease. Absence of EP in MAP(-) patients indirectly support the theory that a mechanical factor is at work. It is, therefore, our opinion, that the cause of ectopic pregnancy lies in the patient and not in the drug (hMG/hCG).

Chorionic Gonadotropin↗