A prospective study of the relationship between semen quality and fertility in cases of unexplained infertility

The male partners of 68 couples exhibiting 5.1 +/- 0.3 (SEM) years of unexplained infertility were assessed using the conventional criteria of semen quality, the movement characteristics of the spermatozoa and the outcome of the zona-free hamster egg penetration test. After a follow-up period of 2.3 +/- 0.06 (SEM) years, 25 (37%) of these patients were found to have initiated a pregnancy, thereby permitting an analysis of those aspects of semen quality which most accurately predicted their subsequent fertility. A multivariate discriminant analysis revealed that the conventional semen profile, per se, was not of significant value in discriminating the incidence of pregnancy. However, significant discrimination (P = 0.0173) was obtained when the postcapacitation movement characteristics of the spermatozoa were incorporated into the analysis. The accuracy of this prognosis was further increased if either the duration of infertility or the outcome of the zona-free hamster egg penetration test was taken into consideration. Overall classifications of fertility were then 76.3% and 76.5% accurate, respectively. These results suggest that in vitro assessments of human sperm function are of significant value in evaluating male fertility.

The relationship between gastric carcinoma and gastric juice lactate (L + D) and lactate dehydrogenase

L-Lactate, D-lactate, and lactate dehydrogenase (LDH) levels were measured in the resting gastric juice of 73 patients and mean levels were found to be significantly higher in patients with gastric carcinoma than in those with benign gastric ulcer or those with normal stomachs. Raised levels of gastric juice L-lactate (greater than 1.3 mmol/l), D-lactate (greater than 0.15 mmol/l), and LDH (greater than 55 IU/1) were seen in 14 of 27 patients with carcinomas, two of 15 with benign ulcers, and six of 31 controls. Both L/D-lactate and LDH levels correlated with tumor size and depth of invasion. While six problem cases with large gastric lesions were correctly diagnosed using these indices, there was only poor sensitivity and moderate specificity, as early cancers had normal L/D-lactate and LDH levels, and these indices were raised in a significant number of controls. Thus while it is of interest that L/D-lactate and LDH are elevated in the gastric juice of patients with gastric carcinoma there appears to be little optimism for using these indices in the early diagnosis of gastric neoplasia.

Analysis of human sperm function following exposure to the ionophore A23187. Comparison of normospermic and oligozoospermic men

Time exposure photomicrography and interspecific in vitro fertilization techniques have been used to compare the responses to the divalent cation ionophore A23187 of spermatozoa from normal fertile and oligozoospermic men. The fertilizing capacity of spermatozoa from the fertile controls produced a bell-shaped dose response curve when assessed in the presence of ionophore. The optimal responses occurred in the presence of 50 and 100 microM A23187. At this concentration, a mean penetration rate of about 75%, in association with multiple polyspermy, was observed without significant changes in motility patterns. At higher doses of A23187, there was a decline in fertilization rates, an independent reduction in sperm motility, and a significant decrease in the amplitude of lateral sperm head displacement. In contrast to the fertile controls, spermatozoa recovered from patients with oligozoospermia failed to exhibit a significant change in their fertilizing potential following exposure to A23187. Calculations based on the Poisson distribution theory indicated that this lack of responsiveness was not related to any differences in the motility of the spermatozoa from the oligozoospermic patients compared to the controls. These results suggest that calcium ionophores may be of value in providing a rapid and sensitive indicator of the functional competence of human spermatozoa, which circumvents problems concerning the rate and efficiency of sperm capacitation encountered with conventional protocols.

The functional competence of human spermatozoa recovered after vasectomy

Progressively motile spermatozoa were present in 42/47 (89%) of post-vasectomy specimens, and in 16 of 24 samples (66%) demonstrable fertilizing potential could be detected in the zona-free hamster egg assay. The mean +/- s.e.m. post-vasectomy penetration rate of 20.6 +/- 6.0% was, however, significantly lower (P less than 0.001) than the pre-vasectomy value of 49.7 +/- 6.4%. After vasectomy the concentration of motile spermatozoa in the ejaculates declined in a manner that was significantly correlated with the post-operative time interval. The spermatozoa also lost their potential for fertilization, although functionally competent spermatozoa were still being recovered from ejaculates produced 8 days after vasectomy. These results emphasize the ability of human spermatozoa to retain some residual fertilizing potential when stored at core body temperature in sites distal to the epididymis, and suggest a role for functional tests in the management of the vasectomized male.

The role of cervical mucus--semen interaction in infertility of unknown aetiology

An in-vitro penetration assay, which incorporates measurements of sperm motility and forward velocity, was used to investigate sperm-cervical mucus interaction in 20 couples with unexplained infertility. Evidence of impaired cervical mucus penetration was found in this group of patients and in seven couples the results correlated with previous assessment by laparoscopic sperm recovery. The impairment of cervical mucus penetration was found to be due to defective sperm function rather than to the quality of the cervical mucus itself. Of the criteria of semen quality measured in this study, sperm motility and the zona-free hamster egg penetration test showed significant correlations with cervical mucus penetration.

The predictability of subnormal penetrating capacity of sperm in cases of unexplained infertility

Multivariate discriminant analysis has been used to determine the predictability of sub-normal penetrating capacity in cases of unexplained infertility. The product of this analysis was the identification of 7 discriminating variables, all of which described various aspects of the post-capacitation movement characteristics exhibited by the spermatozoa, omitting all reference to the conventional parameters of semen quality. On the basis of these discriminating variables, 90.9% of samples exhibiting penetration rates within the normal range were correctly predicted to be functionally competent. The same variables correctly identified only 60% of samples with impaired penetrating capacity, indicating that in the remaining 40%, defects are present in the spermatozoa which are not reflected in their motility patterns.

Chromosome abnormalities in human embryos after in vitro fertilization

In vitro fertilization and embryo transfer is now an established treatment for certain forms of human infertility. High success rates have been reported following oocyte recovery and fertilization in vitro, the only major remaining difficulty being the high failure rate (80%) of implantation after replacement of the embryo into the mother. One possible reason for this failure of implantation is that some embryos may carry a lethal chromosome abnormality which does not allow development beyond the preimplantation stage. The need for information on the chromosomal status of early embryos fertilized and developed in vitro is recognized but two reported attempts to examine them have met with technical problems. Here we describe a method for examining chromosomes in 8-cell human embryos. Although we have made complete chromosome analyses for only three oocytes, our findings are surprising in that two of the three embryos were chromosomally abnormal. Data on the DNA content of the nuclei in a further eight cases showed that approximately 20% overall may be haploid.

An analysis of the direct effects of gossypol on human spermatozoa

The direct effects of gossypol and its acetic acid adduct, on the movement and functional competence of human spermatozoa were investigated employing exposure times of 1, 5 or 15 min and concentrations of 50 microM, 500 microM and 1000 microM. These compounds markedly reduced the motility, velocity, frequency of sperm head rotation and linearity of sperm progression, the most significant effects being observed with gossypol acetic acid on populations of 'capacitated' spermatozoa. Significant direct effects of gossypol on the ability of human spermatozoa to penetrate both cervical mucus and zona-free hamster ova were also observed, which were independent of any effects on motility. These results reinforce the notion that gossypol may serve a contraceptive role in the female as a 'spermicidal' agent, and suggest that this compound may also be of scientific value as a probe for identifying and isolating functionally important components of the human spermatozoon.

The influence of medium composition, osmolarity and albumin content on the acrosome reaction and fertilizing capacity of human spermatozoa: development of an improved zona-free hamster egg penetration test

The influence of medium composition, osmolarity and albumin concentration on the ability of human spermatozoa to undergo the acrosome reaction and penetrate zona-free hamster ova has been investigated. Raising the osmolarity but not the albumin concentration of the media was found to significantly increase the proportion of spermatozoa exhibiting an acrosome reaction and penetrating hamster ova, without influencing motility. There was, however, no correlation between the size of the acrosome reacted population and penetration rates between samples, suggesting that the zona-free hamster egg penetration test is more than just a measure of the availability of acrosome reacted cells. As a result of this study, a revised protocol for the hamster egg assay is described which is shorter and considerably more sensitive than conventional procedures.

Plasma testosterone response to hCG stimulation in the male marmoset monkey (Callithrix jacchus jacchus)

In adult animals the intramuscular injection of hCG was followed by a rapid rise in plasma testosterone levels within 2-3 h and at doses of 40 and 80 i.u. hCG this primary response was followed by a second peak of testosterone at 48 h. Prepubertal marmosets also responded to hCG stimulation with a rapid increase in plasma testosterone levels within 3 h, but the magnitude of this peak was lower than that observed in adult animals and no biphasic pattern was observed. In adult and prepubertal animals a second dose of hCG (40 i.u.) administered 24 h after the initial injection failed to produce a further rapid increment in plasma testosterone levels.

Influence of caffeine on movement characteristics, fertilizing capacity and ability to penetrate cervical mucus of human spermatozoa

When added to frozen-thawed human semen, the 3 doses of caffeine tested (2, 5 and 10 mM) induced a significant increase in the percentage of motile spermatozoa but did not influence the quality of movement. Considerable variability was noted between samples in their responsiveness to caffeine which, at the 5 and 10 mM doses, was significantly correlated with the degree of motility lost during cryostorage. Caffeine treatment of frozen-thawed human spermatozoa also increased the number of spermatozoa penetrating cervical mucus in unit time, by increasing the frequency rather than the success of collisions between spermatozoa and the cervical mucus interface. When caffeine-stimulated spermatozoa were washed free of seminal plasma containing this compound they were no longer at an advantage with respect to their motility or fertilizing ability. When 2 mM-caffeine was added to washed suspensions of capacitated spermatozoa it failed to stimulate motility but did significantly enhance the fertilizing ability of the spermatozoa, indicating a possible clinical role for this compound in in-vitro fertilization therapy.

The preparation of dry, monodisperse microspheres of [99mTc]albumin for lung ventilation imaging

2 micron microspheres of albumin were prepared and labelled with 99mTc according to published methods. However, when the labelling technique was repeated without the inclusion of microspheres, apparent labelling, which was attributed to the formation of a 99mTc tin colloid, was still observed. It was not possible to identify 99mTc tin colloid in the presence of 99mTc microspheres. To establish conditions under which there was no 99mTc tin colloid formation, labelling, with and without microspheres, was studied at low pH for a range of SnCl2 X 2H2O concentrations. A "kit" containing 0.4 mg of microspheres and 1 microgram of SnCl2 X 2H2O in 1 ml of 25 mM HCl gave optimum labelling of 88.3% (SD 3.9, n = 38). Unlabelled and labelled kits were stable for 1 and 3 h respectively. Before administration, the microspheres were resuspended in ethanol, in which they were stable for 6 h. None of the preparations contained 99mTc tin colloid.

An analysis of semen quality and sperm function in cases of oligozoospermia

This study is based upon an analysis of 27 severely oligozoospermic men, in whom defects in sperm motility and morphologic defects were also evident, and 35 control subjects of proven fertility. Semen samples recovered from these men were assessed by conventional criteria, time-exposure photomicrography, and the zona-free hamster egg penetration test. Evidence of severely defective sperm function was obtained for the oligozoospermic group, which gave a mean +/- standard error (SE) fertilization rate of 2.8% +/- 1.5, compared with 44.0% +/- 3.4 for the normal fertile control subjects. Multivariate discriminant analysis was used for selection of those parameters of semen quality that could most accurately identify the 70% of oligozoospermic samples that failed to exhibit any fertilizing potential in the hamster egg assay. This analysis correctly identified 89% of such samples, on the basis of seven discriminating variables, of which the most significant were percentage of motile sperm, the log of sperm density, and a log transformation of the concentration of progressive spermatozoa.

Quantitative noise analysis in a modern hospital

Quantitative noise analysis of a general surgical ward in a modern hospital showed that the level of noise was in excess of recommended levels and of sufficient intensity to disturb sleep. Individual noises in excess of 50 dB(A) were recorded in every area at all times of the day. Internal hospital sounds were responsible for most noise; staff and audible warning devices were the main sources of noise over 70 dB(A). Octave waveband analysis showed that both the general ward noise and the noise of the air conditioning were in excess of recommended levels.

Effective penetration of the lung periphery using radioactive aerosols: concise communication

Radioactive microspheres could offer several advantages over gases in the investigation of pulmonary ventilation. Monodisperse microspheres of human serum albumin have been produced using a spinning-disc generator, and kits were prepared for subsequent labelling with technetium-99m. The average labeling efficiency was 88% and unlabeled Tc-99m was removed before aerosol delivery. A simple system was constructed to nebulize and deliver dry monodisperse microspheres. The ventilation images obtained were compared quantitatively with the corresponding krypton-81m images, subdividing the lung regions into inner, central, and peripheral zones. No significant difference was found in the proportions of the total counts for any lung region. There was good agreement between the distributions of microspheres obtained on separate days (r = 0.97, p less than 0.0001), An "aerosol penetration index" was defined as the ratio of the peripheral to the inner counts for the microspheres normalized by the corresponding ratio for krypton-81m. The mean value of this index for 16 normal subjects was 0.98 +/- 0.23 (s.d.), indicating that the microspheres had achieved penetration of the lung periphery. For patients with chronic obstructive lung disease, more localized defects were observed with the microspheres than with krypton-81m. The mean penetration index for this group was only 0.69 +/- 0.21 (s.d.). This was significantly different from the value for normal subjects (p less than 0.002).

Properties of intact and univalent (Fab) antibodies raised against isolated, solubilized, mouse zonae pellucidae

Intact and univalent antibodies were prepared against mechanically isolated mouse zonae pellucidae solubilized in a variety of ways (heat, low pH, SDS, urea and trypsin). The antisera bound avidly and specifically to solubilized iodinated zona antigens and the intact zona structure. When the concentrations of immunoreactive Fab material in the intact and univalent antibody preparations were equalized and compared for their ability to block the sperm-binding stage of fertilization, only the intact gamma-globulin preparations possessed antifertility activity. These results indicate that antibodies raised against intact solubilized zonae pellucidae block fertilization by cross-linking antigens on the outer zona surface, thereby indirectly masking the sperm receptor sites. The integrity of these surface components did not appear to be affected by solubilization procedures that disrupt non-covalent bonds (heating, low pH, SDS and urea) although they did appear to be adversely affected by trypsin treatment. None of the antisera tested contained antibodies directed against the sperm receptor site indicating that these critical components lack immunogenicity.

An analysis of sperm function in cases of unexplained infertility: conventional criteria, movement characteristics, and fertilizing capacity

A detailed analysis of semen quality was carried out in 85 couples with unexplained infertility by the use of conventional criteria of semen analysis, time-exposure photomicrography, and the zona-free hamster egg penetration test. According to the latter, 34.1% of the male partners exhibited evidence of defective sperm function, although only 4% of these patients were devoid of any demonstrable fertilizing capacity. Of the conventional parameters of semen analysis examined, the most revealing was the morphologic character of the sperm, which was significantly poorer (P less than 0.001) in the group with unexplained infertility than in the normal fertile control group and also showed a significant relationship (P less than 0.001) with the presence of subnormal fertilizing capacity in the hamster egg assay. A majority of movement characteristics measured by time-exposure photomicrography were significantly depressed in the group with unexplained infertility, compared with the normal fertile control group. In addition, certain of the movement characteristics investigated were significantly related to the fertilizing capacity of the spermatozoa; and, in this respect, a progressive swimming speed (greater than 25 micrometers/sec), a straight swimming mode of progression, and a small amplitude of lateral head displacement (Ah) all appeared to be important qualities.

The correlates of fertilizing capacity in normal fertile men

An investigation has been carried out in normal fertile men on the correlates of fertilizing capacity as defined by the zona-free hamster egg penetration test. The results demonstrate that the apparent fertility of these men is compatible with a wide range of intrinsic sperm quality as reflected by penetration rates ranging from 14% to 90% and differences in the minimum concentration of motile spermatozoa required to initiate penetration. These differences in sperm function could not be correlated with any of the conventional parameters of semen analysis or any of a large number of sperm movement characteristics analyzed by time-exposure photomicrography, with two exceptions: (1) the percentage of progressively (greater than 25 micron/sec) motile spermatozoa exhibiting an amplitude of lateral head displacement (Ah) of less than 10 micron, which was positively correlated with penetrating capacity (P less than 0.01), and (2) the percentage of progressively (less than 25 micron/sec) motile spermatozoa exhibiting an Ah of greater than 10 micron, which was negatively correlated with penetration rate (P less than 0.05). The information obtained in this study should provide a useful basis against which to compare the properties of spermatozoa in cases of suspected infertility.

Plasma progesterone levels throughout the ovarian cycle of the common marmoset (Callithrix jacchus)

Radioimmunoassay of progesterone in marmoset plasma has been used to determine ovarian cycle length. Total cycle length was 30.1 +/- 3.8 days (mean +/- SD, n = 30, range 24-41 days, median 29.5 days). The pre-ovulatory (follicular) phase, during which progesterone levels were below 10 ng/ml, lasted for 8.8 +/- 3.7 days (mean +/- SD, n = 30, range 3-20 days, median 8.5 days). The post-ovulatory (luteal) phase, during which progesterone levels were greater than 10 ng/ml, lasted for 21.5 +/- 2.2 days (mean +/- SD, n = 30, range 14-29 days, median 21.5 days). Total cycle length was almost twice that recorded in an earlier study. The reasons for this difference are discussed.

Measurement of the sperm binding capacity of the mouse zona pellucida and its use in the estimation of anti-zona antibody titres

Conditions have been defined under which the sperm binding capacity of the mouse zona pellucida can be measured. As a measure of the concentration of anti-zona antibodies the inhibition of sperm binding appears to be both repeatable and sensitive. Using this technique anti-zona antibody titres were monitored in 6 rats actively immunized with extracts of mouse ovarian tissue. These animals exhibited a rapid rise in anti-zona antibody titre following the induction of immunity, and an associated significant (P less than 0.05) decline in their fertility, both in relation to the proportions of animals exhibiting fertile matings and of matings resulting in conception. Three of the animals exhibited permanent sterility despite repeated exposure to fertile males.