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Biomedical subjects

L I Lipshultz

Publications and source records attributed to L I Lipshultz.

At least 127 records · Page 7Linked to original sources
PubMed1982

Characterization of human Sertoli cells in vitro.

The Sertoli cell is thought to play a significant role in the hormonal regulation of spermatogenesis within the rat testis. Little, however, is known about Sertoli cell function in man, largely because of the difficulties associated with the isolation of pure cell populations from human tissue. We have now developed a rapid and reproducible technique for establishing a human Sertoli cell monolayer culture. This has involved mechanical separation of the tissue, sequential trypsin and collagenase enzyme digestion, and final disruption of tubules by passage through a wire mesh grid. Using this technique, primary cultures can be maintained for up to 45 days. Ultrastructural studies of these cells have demonstrated the presence of the perinucleolar spheres, cell to cell junctional complexes, abundant lipid droplets, and smooth endoplasmic reticulum, all characteristic of Sertoli cells. Furthermore, biochemical markers of animal Sertoli cells, androgen-binding protein and gamma-glutamyl transpeptidase, have also been identified in these human cells. Concentrated media electrophoresed on nondenaturing gels containing 2 nM [3H]dihydrotestosterone produced a single peak of bound activity which coelectrophoresed with rat androgen-binding protein. This binding activity persisted despite media changes, thus ruling out contamination by serum binding proteins; fresh media lacked demonstrable binding activity. Using a colorimetric assay, these cells were also found to contain significant gamma-glutamyl transpeptidase activity compared to human foreskin fibroblasts and Leydig cells. Enzyme activity increased in a characteristic dose-response fashion in the presence of FSH (0.05-0.5 microgram/ml) and dibutyryl cAMP (0.1-1 microgram/ml), but not with LH or testosterone. These data offer the first demonstration of human Sertoli cells in monolayer culture and their production of a marker specifically regulated by FSH.

Androgen-Binding Protein↗
PubMed1982

Cryptorchidism and infertility.

Although the maldescended or dystopic testis is one of the most common congenital anomalies in man, proper treatment remains a subject of much discussion and confusion. Certainly, in light of the previously described findings, the future fertility of the patient with unilateral cryptorchidism, regardless of age of correction, should be a realistic concern. Hormonal treatment should be recognized as a good diagnostic test for defining the retractile testes and should not be considered therapy. The pediatrician or family practitioner should be encouraged to examine the scrotal contents thoroughly in the neonatal period and to document findings. Earlier surgical intervention may benefit these patients since a prolonged extrascrotal location may add further insult to an intrinsic abnormality in the dystopic gonad. The cryptorchid testis may be smaller and have decreased consistency with or without surgery and usually signals significant testicular pathology. Synthesis of androgens and serum concentrations of LH should not be affected; thus, secondary sex characteristics will appear normal. Basal levels of FSH are usually elevated but do not necessarily imply overwhelming testicular damage. Current evidence clearly shows a variable degree of primary intrinsic gonadal dysgenesis with a frequent impairment of fertility in the cryptorchid testis, regardless of the time of treatment. Early surgery may decrease the ultimate loss of testicular function superimposed on the congenital dystrophy, thus diminishing the ultimate loss of effective spermatogenesis.

Adolescent↗
PubMed1982

Transferrin and gonadal dysfunction in man.

Transferrin concentrations were quantitated in the seminal fluid of normal, oligozoospermic, and azoospermic patients and related to other known parameters of testicular function. Transferrin concentration in the semen of patients 2 months after vasectomy (13.2 +/- 1.8 micrograms/ml) was significantly less than that obtained from pregnancy-proven donors (65.6 +/- 10.1 micrograms/ml). This indicates that approximately 80% of the seminal fluid transferrin is derived from the testes. The concentration of transferrin in semen from patients with azoospermia (14.4 +/- 1.8 micrograms/ml), severe oligozoospermia (17.5 +/- 1.7 micrograms/ml), and moderate oligozoospermia (21.8 +/- 4.3 micrograms/ml) was significantly lower than normospermic groups. Serum follicle-stimulating hormone (FSH) was measured in a group of infertile patients; those having an elevated FSH had a significantly lower concentration of semen transferrin, 14.1 +/- 1.6 micrograms/ml, compared with patients who had FSH levels within the normal range (33.7 +/- 5.3 micrograms/ml). It is possible that the underlying cause in decreased spermatogenesis associated with both an elevated FSH and a decreased transferrin concentration is impaired Sertoli cell function.

Follicle Stimulating Hormone↗
PubMed1981

Testicular function among epichlorohydrin workers.

Epichlorohydrin (1,2-epoxy-3-chloropropane) (ECH) is a colourless liquid used in the production of insecticides, agricultural chemicals, epoxy resins, and many other productions. It is highly reactive and an alkylating agent suspected of possessing carcinogenic properties in man. The results of a clinical-epidemiological investigation to ascertain whether exposure to ECH may be associated with sperm count suppression among ECH production workers at two chemical plants are presented. Medical histories and physical examinations with special emphasis on the genitourinary tract were completed on each participant. Blood samples and three semen specimens were also obtained. Since no internal control group were available, the data arising from this effort were analysed for each plant (plant A, 44 men; plant B, 84 men) using a control group of 90 chemical plants workers unexposed to any agents known to be toxic to the tests who were included in previous studies. This study provides no evidence that exposure to ECH at the concentrations existing at the two plants studied is responsible for sperm count suppression.

Chemical Industry↗
PubMed1981

The effect of vasectomy on Sertoli cell function in rats.

In order to evaluate Sertoli cell function after vasectomy, we studied a group of 24 rats. Twelve animals underwent bilateral vasectomy and 12 control animals underwent a sham operation. At 3 and 8 weeks postvasectomy, six experimental and six control animals were sacrificed. Forty-eight hours before sacrifice, the efferent ducts of the testes of each animal were ligated to produce intratesticular androgen-binding protein (ABP) accumulation. Quantification of ABP was determined using a steady-state polyacrylamide gel electrophoresis system and a 2 nM 3H-dihydrotestosterone label. The ABP of the vasectomized and control animals was expressed as both picomoles per milligram of protein and picomoles per organ and was found to be 0.28 +/- 0.06 and 0.42 +/- 0.09 for the control and vasectomized animals at 3 weeks and 0.46 +/- 0.07 and 0.52 +/- 0.08 for similar groups at 8 weeks. Comparison of these values revealed no statistical significance. Vasectomy, therefore, had no demonstrable effect on Sertoli cell function in the rat and our findings support the concept that ligation of the vas does not result in long-term biochemical testicular damage in the experimental animal.

Androgen-Binding Protein↗
PubMed1980

Radioisotope angiography in diagnosis of varicocele.

A varicocele, the most common surgically correctable cause of subfertility in men, is a manifestation of abnormal retrograde venous blood flow through the internal spermatic vein into the peritesticular pampiniform plexus. Methods of diagnosing the varicocele, including careful physical examination using a Valsalva maneuver as well as a Doppler stethoscope, remain somewhat subjective. Venography, while a reliable and objective technique, is invasive and not without morbidity. In the present study, 16 patients with clinically detectable varicoceles of various sizes were studied using a testicular radioisotope angiogram developed in our laboratory. Following the injection of 15 mg. of stannous pyrophosphate which results in tagging of the circulating red cell pool, 20 mCi. of 99m-technetium were administered in an intravenous bolus injection. The isotope binds to the pyrophosphate thus tagging the red blood cells and creating a blood-pooling agent with a relatively short half-life (six hours). Perfusion studies as well as static views of the scrotal contents, both in the supine and erect position, with and without Valsalva maneuver, were obtained using a gamma camera. The activity in each hemiscrotum then was quantitated using a digital computer. It is proposed that quantitation of this differential blood pool will make the identification of even subclinical varicoceles a potentially objective determination.

Humans↗
PubMed1980

Dibromochloropropane and its effect on testicular function in man.

This study represents the largest series to date documenting the gonadotoxic effect in humans of dibromochloropropane, a widely used pesticide. Three semen analyses, serum hormonal determinations (luteinizing hormone, follicle-stimulating hormone and testosterone) as well as genital examinations were completed for 228 workers at 2 chemical production sites and consisting of a dibromochloropropane-exposed and non-exposed cohort. Parameteric and non-parametric statistical analyses of the data sets of the sperm densities from the 2 subpopulations demonstrated statistical significance (p less than 0.10) at the short-term (1.5 years) manufacturing plant. Log transformation of the sperm count and hourly exposure data were necessary to develop meaningful statistical conclusions. The serum concentration of follicle-stimulating hormone as a group mean was significantly greater at both production sites for the exposed cohort when compared to the non-exposed participants but decreased by 10 levels of magnitude when the group demonstraing shorter but more recent exposure was compared to those from the plant with longer chemical production. Finally, a dose-response model suggested significant changes in sperm density at the short-term but more recently operated production site when more than 100 adjusted hours of exposure were exceeded, while the longer operated but longer closed facility demonstrated a significant impairment only when more than 1,000 adjusted hours of dibromochloropropane exposure were surpassed. This difference in exposure data may reflect regenerative changes in the tests once the gonadotoxic substance had been removed but exact nature of the dibromochloropropane effect and the possibility of a "no effect" concentration remain to be defined clearly.

Antinematodal Agents↗
PubMed1980

Neuromorphology and neuropharmacology of the human penis: an in vitro study.

The neuromorphology and neuropharmacology of the human penis are only briefly described in literature. The present study was undertaken to define the adrenergic and cholinergic neuromorphology of the human corpus cavernosum (CC) and corpus spongiosum and to evaluate the in vitro response of the CC to pharmacologic stimulation. Human penile tissue was obtained from six transsexual patients undergoing penectomy. For morphologic study, the tissue was processed for (a) hematoxylin and eosin staining; (b) smooth muscle staining; (c) acetylcholinesterase localization; (d) glyoxylic acid histofluorescence; (e) electron microscopy; and (f) electron microscopy after glutaraldehyde dichromate fixation. In addition, strips of CC were placed in in vitro muscle chambers and tension changes recorded isometrically after stimulation with norepinephrine (NE) and acetylcholine. The CC contains abundant smooth muscle, numerous glyoxylic acidfluorescent (catecholaminergic) fibers and varicosities, and a scant distribution of acetylcholinesterase-positive fibers. Fewer of all these elements were present in the corpus spongiosum. No "polsters" were observed in the CC. Although glutaraldehyde-fixed controls exhibited no typical adrenergic vesicles (small, dense core, measuring 400-600 A in diameter), some small, strongly electron-dense vesicles were found in glutaraldehyde dichromate-fixed tissue and were thought to contain NE. A variety of other vesicles were also encountered. The addition of NE to the in vitro muscle chambers caused a dose-related contraction, which was blocked by pretreatment with phentolamine in all CC strips tested. Acetylcholine in high concentration produced minimal contraction in 2 of 24 strips. Our morphologic and pharmacologic data suggest that the sympathetic nervous system may affect erection by acting not only on the penile vasculature but also by direct action on the smooth muscle of the CC itself.

Acetylcholine↗
PubMed1980

Vasectomy--1980.

Explore the source record for details and available documents.

Adult↗
PubMed1979

A preliminary report of "subclinical varicocele": diagnosis by Doppler ultrasonic stethoscope. Examination and initial results of surgical therapy.

Two hundred sixteen consecutive infertility patients were examined with the Doppler ultrasonic stethoscope to detect incompetence of the gonadal vein valves, the precursor of frank varicocele. All 75 men with clinically palpable varicoceles had positive Doppler findings. In 33 cases varicocele could not be definitely excluded because of unsatisfactory physical examinations; the Doppler findings were negative in 13, positive in 13 and equivocal in 7 of these men. Eighty-nine men had no evidence of varicocele on physical examination and negative Doppler findings. However, 19, patients with no palpable varicocele had positive Doppler examinations. With respect to testicular size and semen quality, this subclinical varicocele group could not be clearly distinguished from patients with idiopathic semen quality depression. Nevertheless, five men with subclinical varicocele and oligoasthenospermia underwent internal spermatic vein ligation. Postoperatively, four had negative Doppler examinations. Two patients showed a significant improvement in semen quality, and both men fathered children after several months. We believe that these preliminary results justify further investigation of "subclinical varicocele".

Adult↗
PubMed1978

Stimulation of cyclic adenosine 3':5'-monophosphate accumulation in human testes in vitro by luteinizing hormone, follicle-stimulating hormone, and prostaglandins.

The gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) stimulate cyclic adenosine 3':5'-monophosphate (cyclic AMP) accumulation in human testicular incubates. The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine acts synergistically with LH and FSH to enhance cyclic AMP accumulation. These studies indicate that cyclic AMP accumulation may be involved in the mechanism of action of LH and FSH in the human testes, as has been proposed for rat testes. The prostaglandins (PG PGE1, PGE2, PGA1, and PGF2alpha stimulate cyclic AMP levels at 10(-4) M in human testes. The E type prostaglandins are the most potent. They induce half-maximal stimulation of cyclic AMP at 7 x 10(-7) M.

1-Methyl-3-isobutylxanthine↗
PubMed1978

Experience with 425 subfertile male patients.

Subfertility was evaluated in 425 men. Varicocele were diagnosed in 37.4 per cent of these patients and surgical correction of the varicocele in 68 men resulted in a 65 per cent improvement in semen quality. Idiopathic abnormalities were found in 25.4 per cent of the patients. Since the study group was heterogenous setereotyped or empirical treatment cannot hope to be successful if uniformly applied. Other specific causes of male subfertility are identified and therapeutic options are discussed.

Adult↗
PubMed1977

Progressive testicular atrophy in the varicocele patient.

We examined 82 healthy volunteers, 61 subfertile men with varicoceles and 27 subfertile men without varicoceles for testicular size and semen quality. In 13 volunteers we found unsuspected varioceles and a left testicle significantly smaller than the other 69 volunteers. The size of the right testicle and the sperm density in these patient groups were similar. Both testicles of subfertile male subjects with varicoceles were significantly smaller than the testicles of subfertile male subjects without varicoceles. However, the sperm densities of these 2 groups were similar. Finally, although subfertile male subjects with varicoceles had obviously statistically lower sperm densities than volunteers with varicoceles, the testicular sizes were similar. Perhaps varicocele ligations should be performed on all male subjects with this lesion at an early age to prevent progressive testicular atrophy and decreased fertility potential.

Adult↗
PubMed1977

The use of the Doppler stethoscope in the evaluation of varicoceles.

Twenty-eight clinically detectable varicoceles of various sizes were examined with a Doppler ultrasonic stethoscope. Retrograde blood flow through the left internal spermatic vein was confirmed in all cases irrespective of size of the vascular abnormality. The Doppler stethoscope also was used to evaluate 13 patients suspected of having varicoceles but with inconclusive physical examinations. Retrograde flow through the internal spermatic vein could likewise be auscultated in 5 of these patients. Finally, the Doppler stethoscope was used to determine the adequacy of internal spermatic vein ligation in 5 postoperative patients whose seminal dysfunction persisted despite what appeared to be a surgically effective correction of aberrant gonadal venous flow.

Epididymis↗
PubMed1977

Supranormal FSH response to gonadotrophin-releasing hormone in oligospermic men with a normal basal serum FSH concentration.

Twenty-six men with severe oligospermia (sperm density less than 10 X 10(6)/ml, but greater than O), but normal serum concentration of FSH, as well as normal serum concentrations of LH and testosterone, were given a 250 microgram i.v. bolus dose of synthetic gonadotrophin releasing hormone (LHRH). The serum FSH and LH responses were compared to those of a group of normal men and a group of men with oligospermia or azoospermia and elevated basal serum FSH concentration. The mean FSH response to LHRH of the men with oligospermia but normal basal serum FSH concentration was 911 miu min/ml, nearly three times that of the normal men, 322 miu min/ml (P less than 0.001), though not so great as that of the men with oligo/azoospermia and elevated basal FSH concentration (2890 miu min/ml). Ten of the twenty-six men with oligospermia and normal basal serum FSH had a supranormal FSH response to LHRH. The mean LH response to LHRH of the men with oligospermia and normal basal serum FSH levels was not significantly different from that of the normal men. We conclude that LHRH stimulation can often elicit a deficiency of feedback inhibition of FSH secretion not readily recognizable by measurement of the basal serum FSH concentration.

Adult↗