Seminiferous tubule hypercurvature: A newly recognised common syndrome of human male infertility

Clinical assessment of male infertility in the era of intracytoplasmic sperm injection

This communication outlines the major causes of infertility in the male and, where indicated, the application of in vitro fertilization and intracytoplasmic sperm injection in their treatment. It also points out that there are many types of infertility in the male where other methods of treatment are also successful and where reproductive technology is unnecessary.

Effects of high doses of testosterone propionate and testosterone enanthate on rat seminiferous tubules--a stereological and cytological study

The effects of exogenous testosterone on various testicular variables has become of increasing significance because of its potential use in male contraception. For this reason, high doses of two testosterone esters [testosterone propionate (TP) and testosterone enanthate (TE)] were used in a study of their influence on the morphology, length and curvature of the seminiferous tubules of the rat testis, and on cytological smears of the seminiferous tubules epithelium. TP was given for 14 days (3 mg/100 g body weight, i.m.) to assess the acute effects of testosterone on the seminiferous tubules. TE was administered for 60 days (in the same manner as TP) to study possible chronic effects on the rat testis. After TP and TE treatment the seminiferous tubule epithelium showed disorganization and desquamation of spermatogenic cells. In the TP-treated testes the tubules lined with Sertoli cells only were observed. The values for the length and curvature of seminiferous tubules of the TP- and TE-treated rats were significantly reduced (p < 0.001). All these changes were observed earlier in the TP-treated than in the TE-treated animals. In cytological smears of the testis of the TP- and TE-treated rats an increase of vacuoles and residual bodies in Sertoli cell cytoplasm was noted. In addition, a reduction of spermatogenic cells, particularly sperms, was manifest in the smears after treatment. Large groups of Sertoli cells were seen in the smears from these testes.

A modification of testicular biopsy reporting

A modified method has been devised which enables the pathologist to evaluate more efficiently the seminiferous tubules and to present a more detailed histological report on testicular biopsies in patients investigated for infertility. This basically involves the production of a diagrammatic representation of the actual biopsy onto a specifically designed reporting form: a detachable prismatic arm attached to an ordinary light microscope enables the pathologist to transfer an actual outline of each of the seminiferous tubules contained in the biopsy onto this form. The seminiferous epithelium and Leydig cells are scored using the method of Johnsen. This method was evaluated using 20 consecutive biopsies. Skill in its usage was quickly acquired and it has been found to be a more clinically acceptable way of histopathological reporting, further facilitating standardization and inter-laboratory comparison.

Effects of neonatal estrogen administration on rat testis development with particular reference to Sertoli cells

An ultrastructural and morphometric study of the testes in 15-, 22-, 45-, and 90-day-old neonatally estrogenized rats was performed. At 45 days of age, the Sertoli cells appeared immature in estrogenized rats, whereas they were fully mature in the controls. This finding might be related to a deficiency in gonadotropins and androgens during the postnatal period. In 90-day-old estrogenized rats, however, Sertoli cell maturation had occurred, which might be attributed to a recovery of hormone levels. Cytoplasmic alterations, however, such as vacuolation, were present at this age. The morphometric study revealed decreased testicular and tubular volumes as well as decreased mean tubular diameters in the estrogenized animals. In contrast, the absolute tubular length increased more in these animals than in the controls during the period from 15 to 90 days of age. This lengthening process might be related to the large number of hypercurved tubules in the estrogenized rats.

Cytogenetic and histological studies of testicular biopsies from subfertile men with chromosome anomaly

Testicular biopsies from eight men with abnormal karyotypes have been examined for histological and cytogenetic evidence of disturbances of meiosis. Quantitative analysis of this material showed one, with a 13;14 Robertsonian translocation, to have apparently normal spermatogenesis. Three patients, one with a 47,XYY and two with 45,XY, inv 9 karyotypes, had an overall depression of spermatogenesis. Four others, all with major chromosomal abnormalities, had apparently normal spermatogenesis until the primary spermatocyte stage. Two of these had sex autosomal translocations. One, 45,Y,t(X;21), had a complete block at MI, the other, 46,X,t(Y;16), had a partial block at spermatid formation. One man with a reciprocal 2;10 translocation showed delay at all stages beyond spermatocyte formation and one man with an inversion of chromosome 3 showed impaired spermatid maturation.

Comparative studies of spermatogenesis in fertile and subfertile men

Testicular biopsy specimens from 16 fertile and 10 subfertile men with normal male karyotype were studied quantitatively to provide histological and cytogenetic data for a basis of reference in assessing abnormalities of spermatogenesis. Histological studies included estimation of the proportion and activity of germinal epithelium and an assessment of tubular morphology. In cytogenetic preparations, counts were made of cells at different stages of meiosis. Studies of cells at diakinesis included chiasma counts and percentage of cells with dissociated sex chromosomes. One fertile and six subfertile men showed decreased germinal activity; the six subfertile men also had decreased MII/MI ratios. Other findings were similar in the two groups.

Discrimination of hyperplasia and carcinoma of the endometrium by quantitative microscopy--a feasibility study

Endometrial hyperplasias and carcinomas have been investigated by quantitative microscopical methods. The aim of this study was to develop an objective method of histopathological diagnosis because of the great subjective variability of these endometrial conditions. A total of 79 cases were studied. Only those were included, which, after re-examination of the material by different pathologists, were regarded as mild atypical hyperplasia (38 cases), marked atypical (adenomatous) hyperplasia (11 cases), well and moderately differentiated adenocarcinoma (19 and 11 cases, respectively). There are many significant differences between these four groups. Stereological features contained the most important information, whilst nuclear features were less successful discriminators. The volume percentage of the epithelium and of the glands and the inner surface density of the glands showed the most significant differences between adenomatous hyperplasia and well differentiated carcinoma. On the basis of these findings, a quantitative model is suggested which might give more insight into the development of these abnormalities, assuming a gradual transition from one to another. The great advantage of the quantitative analysis of data over subjective impressions, it that is is objective, and provides consistently reproducible results. The present results may be especially useful when histopathological diagnosis is in doubt. It is concluded that application of quantitative microscopy in the discrimination of endometrial hyperplasia and carcinoma in histopathology is feasible.

A quantitative structural model of the testis of fertile males with normal sperm counts

The morphology of testicular biopsies of 8 healthy fertile men with proven normal sperm counts was studied using stereological techniques. Quantitative estimations were made of different cellular compartments in the testicular biopsies. The experimental errors of observation, homogeneity of the section, accuracy of the measurements and errors caused during the preparation of the sections were studied. A stereological model of the human testis comprising all compartments was designed. The present observations on the stereological parameters were compared with the results in literature; generally a good agreement was found. This stereological model enabled the authors to establish the quantitative correlations that exist between the separate compartments of the human testis. The tubular length density was positively correlated with the tubular surface density. The tubular surface density showed a negative correlation with the volume density of the germinal cell nuclei. The tubular volume density showed a negative correlation with the volume density of the Leydig cells. The intra-tubular volume density correlated negatively with the volume density of the Leydig cells and with the volume density of the remaining extra-tubular tissue. The intra-tubular tissue density correlated negatively with the volume density of the intra-tubular space.

Histopathological diagnosis of hypercurved seminiferous tubules

A simple method for the recognition of hypercurvature of the seminiferous tubules in otherwise normal biopsies from infertile males consists of the recognition of characteristic 'figure 8' profiles of sectioned seminiferous tubules. Nineteen cases of morphometrically verified hypercurvature and 24 controls were tested in order to determine the validity of the method, which showed virtually no overlap in the two groups when at least four x 100 fields were assessed for 'figure 8' and grazing profiles. A recommended diagnostic approach, with cautions concerning pitfalls, is presented, and incidence, pathogenesis, and potential treatment are briefly discussed.