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Biomedical subjects

J P Tyler

Publications and source records attributed to J P Tyler.

At least 55 records · Page 3Linked to original sources
PubMed1983

Effects of surgical lubricants on semen analysis.

The effects of a number of commercially available surgical lubricants on the motility of spermatozoa with time, have been examined with the aim of recommending a non-toxic, water soluble aid which was not visibly detrimental to spermatozoa following collection of semen for routine analysis. The results have shown that motility is impaired at concentrations above 5%, but that below this level of contamination, spermatozoal motility, and progression, as objectively determined by multiple exposure photography, was unaffected. For various practical reasons, and because it is well known, K-Y Jelly, packaged as a single sachet, is probably the lubricant of choice.

Dose-Response Relationship, Drug↗
PubMed1982

The effect of storage time and molybdate on steroid receptors in gynaecological tissues.

Human female reproductive tract tissues were analysed for estrogen and progestogen receptor content in the presence or absence of sodium molybdate immediately after removal at surgery. Other fractions of the tissue were stored in liquid nitrogen and similarly analysed after 2, 4, 6 and 8 weeks storage. The results showed that at all times the apparent receptor content for both steroids was significantly higher (P less than 0.001) and Kd values were significantly lower (P less than 0.02) in assays carried out with 10 mM molybdate added to the buffer systems. Furthermore, as soon as either whole tissue or tissue cytosol was frozen for storage, receptors were "lost" with values decreasing by approximately 30% for both steroid receptors. However, once frozen in liquid nitrogen tissue receptor content remained stable over the eight weeks of study. It is recommended that laboratories standardize techniques to allow valid comparisons of results.

Cytosol↗
PubMed1982

An office procedure for leucocytospermia.

A 'test strip' procedure (Cytur-Test, Boehringer-Mannheim, Gmbh) was evaluated for distinguishing leucocytes from immature germ cells in semen with high round cell counts.

Humans↗
PubMed1982

Studies of human seminal parameters with frequent ejaculation. I. Clinical characteristics.

The intra-subject variation in seminal parameters (e.g. volume; spermatozoal density, motility and normal morphology, and total spermatozoal count) have been examined in 172 men following a set ejaculatory pattern designed to exhaust their extra-gonadal spermatozoal reserve. The results have demonstrated that the motility and normal morphology of spermatozoa do not change significantly with ejaculation frequency. Also, while the volume of the ejaculate and the total number of spermatozoa decreased during a period of frequent coitus, an individual's depletion and recovery of his spermatozoal reserve could not be accurately predicted. It is suggested that coital frequency during the woman's periovulatory period could be modified by the partner's response to this test. Furthermore, while it is acknowledged that the variation in results from a 'routine' semen analysis is large, data obtained after depletion of the extra-gonadal reserve and recovery over a set time may have more value and could be the method of choice for the future.

Adult↗
PubMed1982

Studies of human seminal parameters with frequent ejaculation II. Spermatozoal vitality and storage.

The hypothesis that the percentage of dead spermatozoa in an ejaculate is related to their storage time in the extra-gonadal reserve was tested using a protocol where men followed a set ejaculatory pattern. Semen samples were requested as follows: abstinence from ejaculation for at least 3 days (not more than 7 days) followed by production of the first sample, then one ejaculation per day for 4 consecutive days before the second sample; and, lastly, abstinence for a further 4 days and production of the final sample. Within the time scale of the experiment there was no relationship between the percentage of dead spermatozoa in the ejaculate and the preceding period of abstinence, nor was the percentage of dead spermatozoa related to the total number of spermatozoa present. The percentage of non-motile, but vital, spermatozoa similarly exhibited a random pattern. Thus whatever mechanisms are contributing to the mortality of spermatozoa, they are independent of storage time in the extra-gonadal reserve, and total spermatozoal count. Therefore, in the absence of necrozoospermia, this parameter probably contributes little to the overall diagnosis of infertility, but does allow assessment of the functional spermatozoa present.

Adult↗
PubMed1981

Testicular testosterone concentration, interstitial cell density and spermatogenesis in infertile men.

The concentration of testosterone was estimated in testicular biopsies taken from infertile men under general anaesthesia and was found to vary between 0.77 and 9.87 nmol/g wet tissue (median 3.41 nmol/g). Spermatogenesis was assessed by the Johnsen scoring technique but there was no evidence of a deficiency of intratesticular testosterone being associated with dysfunction of the seminiferous tubules. Similarly, there was no direct relationship with testicular size, clinical diagnosis, or the concentration of testosterone found in peripheral plasma taken at the same time as the testicular biopsy. These negative findings were not explained by variation in the volume densities of the Leydig cells assessed in 10 biopsies selected to the representative of the range of testosterone concentrations found in entire series. A retrospective comparison between the concentration of testosterone in peripheral plasma at the time of surgery and the available preoperative levels found in 10 patients provided further evidence for the previously reported lowering of testosterone levels by general anaesthesia. It is suggested that future studies of testicular androgens should be conducted on tissue obtained under local anaesthesia in order to eliminate this effect.

Adult↗
PubMed1981

The clinical application of electron microscopy and the heterologous ova penetration test to the assessment of spermatozoa from infertile men.

Ultrastructural studies of spermatozoa from men whose spermatozoa repeatedly had shown poor motility demonstrated an increase in morphological abnormalities. This was considered significant in the 8 men in whom all of the spermatozoa were abnornmal and probably significant in those where more than 90% were abnormal (9 men). Spermatozoa from 15 fertile men adhered to and penetrated 60% of hamster oocytes, whereas those from infertile men, with both normal and poor semen quality, failed to adhere or penetrate. The heterologous sperm penetration test offers a new approach to the assessment of semen quality in infertile men.

Animals↗
PubMed1981

Dissociation of oocyte maturation and ovulation in mice pretreated with a derivative of dihydropyridazinone.

Treatment of mice with a dihydropyridazinone derivative (6-(4'-aminophenyl)-4,5-dihydro-5-methylpyridazin-3-one; ICI 109,081) inhibited the maturation of oocytes in the presence of gonadotrophins without affecting ovulation. The spontaneous resumption of meiosis in oocytes cultured in vitro was reversibly inhibited. ICI 109,081 may therefore be useful for evaluating the relationship between follicular development and the resumption of meiosis.

Animals↗
PubMed1981

Heterologous ovum penetration by human spermatozoa.

An evaluation of a method utilizing zona-free hamster ova to test the fertility of human spermatozoa has shown that (i) the induction of superovulation in immature animals provides the most convenient method of obtaining mature ova for study; (ii) motile spermatozoa are best prepared by the technique of layering; (iii) an 18 h incubation at 37 degrees C (which is associated with capacitation) in an atmosphere of air (pH of medium 8.2) is preferable to one of 5% CO2 (pH of medium 7.2); (iv) the incubation and insemination densities of spermatozoa should be greater than 1 X 10(6) and less than 10 X 10(6)/ml; (v) spermatozoa do not remain motile, or capable of binding to or penetrating ova, after about 30 h in culture; and (vi) intra- and inter-assay variations are acceptable. The spermatozoa from 15 healthy men of proven fertility and 15 subfertile patients with normal spermiograms were evaluated for their ability to bind to and penetrate zona-free hamster ova. Of the 476 ova inseminated with spermatozoa from the fertile men greater than 5 spermatozoa/ovum consistently bound to the vitelline membrane and 284 ova (59.7%) had swollen sperm heads to pronuclei (still with tails attached) in their ooplasm. The range of individual penetration rates was 23.5-88.9%. Of the 586 ova tested with spermatozoa from the infertile subjects only 11 (1.9%) showed any evidence of penetration (range of individual penetration rates 0-8.7%) and binding to the vitelline membrane was poor (0 or less than 5 spermatozoa/ovum). Spermatozoa from a further 9 infertile men who had abnormal spermiograms also gave poor penetration rates (4/300 ova, 1.3%). It is concluded that this bioassay has a useful role as an additional test to the classic spermiogram, but that its routine use is best reserved for selected cases of unexplained infertility.

Animals↗
PubMed1980

The Doppler assessment of varicoceles and internal spermatic vein reflux in infertile men.

The Doppler technique has been used to evaluate venous reflux in the spermatic cord. Valsalva-induced reflux occurred on the left side in 83% and on the right side in 59% of 118 patients without clinical varicoceles and there was no difference in incidence between fertile and infertile men. The significance of Valsalva-induced reflux should be questioned. Greater importance should be attributed to the spontaneous venous reflux that occurred during quiet respiration in the majority of patients with varicoceles. Seven velocity waveform patterns are described and these are thought to represent increasing degrees of internal spermatic vein reflux and provide a basis on which it is possible to grade varicoceles. The Doppler grades correlated with the size of the varicocele, and with the internal spermatic vein diameter and testosterone concentrations.

Humans↗
PubMed1980

Effect of steroids on oocyte maturation and atresia in mouse ovarian fragments in vitro.

Ovaries from pubertal mice were dissected into fragments containing 1-4 antral follicles which were cultured on the surface of a chemically defined, modified Eagle's Minimum Essential Medium (MEM). After 17-20 h oocytes were released from the cultured follicles and their meiotic status recorded. In the presence and absence of exogenous gonadotrophins, oocytess in these cultures behaved meiotically as expected if they had been studied in vivo. Medium containing progesterone (10 microM), testosterone (100 microM), or androstenedione (100 microM) increased the incidence of oocytes remaining meiotically inactive compared to follicles cultured in steroid-free medium. Lower concentrations of the above steroids or pregnenolone (1-100 microM) did not affect the meiotic status of cultured follicle-enclosed oocytes. Most (61%) of the dictyate oocytes released from steroid-treated follicles resumed and/or completed the first meiotic division when cultured further in steroid-free medium. Progesterone (100 microM) caused atresia of oocytes and follicle cells which increased as the period of follicular exposure to progesterone was increased.

Androstenedione↗
PubMed1980

Urinary testosterone-17 beta-glucuronide as an indicator of androgen output in mice.

The androgenic status of female mice was assessed by measuring the concentration of testosterone-17 beta-glucuronide in serial samples of unextracted urine. The subcutaneous administration of testosterone (50 micrograms in lauric acid ethyl ester) resulted in a significant increase (P < 0.01) of the mean +/- s.d. concentration of urinary testosterone-17 beta-glucuronide (25.9 +/- 6.5 to 71.7 +/- 12.9 ng/ml) within 2 h. The 2-h values after the administration of 50 micrograms androstenedione or 50 micrograms dehydroepiandrosterone were 22.8 +/- 4.4 to 81.8 +/- 7.8 ng/ml (P < 0.001) and 23.4 +/- 2.7 to 121.8 +/- 20.3 ng/ml (P < 0.001) respectively. The values decreased progressively over the next 24 h. After the induction of superovulation with PMSG and hCG, the values for testosterone-17 beta-glucuronide increased significantly (P < 0.01) during the periovulatory period (5--24 h after hCG injection). The mean +/- s.d. value in pregnancy was higher (61.8 +/- 11.6 ng/ml; P < 0.001) than that in non-pregnant animals (30.7 +/- 12.3 ng/ml) and remained relatively constant between Days 1 and 16.

Androstenedione↗
PubMed1979

The hormonal and immunological status of vasectomised men.

The concentration of FSH, LH, testosterone and sperm agglutinating and cytotoxic antibodies have been determined in 87 men at varying time intervals after vasectomy. The results indicated that vasectomy is not associated with statistically significant changes in any of these parameters. Furthermore, no correlation existed between the development of sperm antibodies and the peripheral endocrine status of an individual.

Adult↗
PubMed1979

The concentrations of urinary oestrone-3-glucuronide, LH and pregnanediol-3alpha-glucuronide as indices of ovarian function.

Methods based upon the principles of radioimmunoassay have been developed and evaluated for the measurement of oestrone-3-glucuronide, LH and pregnanediol-3alpha-glucuronide in samples of unextracted urine. The procedures have been applied to daily urine (early morning fraction and combined 24 hour collections) from 6 women throughout one complete menstrual cycle and to serial samples from an additional 14 women who only collected early morning specimens. The results showed that there were characteristic, well-defined changes in the concentration of all 3 metabolites in both samples of urine and from all subjects. In addition, there was a reasonable correlation between the concentration of all 3 compounds in samples of early morning urine and the corresponding rates of excretion per 24 hours. These findings suggest that the procedures may be of value for monitoring ovarian function over long periods of time, without the problems of stress and inconvenience to the patient. Furthermore, the ratio of values for oestrone-3-glucuronide to pregnanediol-3alpha-glucuronide may be used to indicate the start and finish of the fertile period.

Adult↗