No abstract

Of 723 infertile men (128 with a history of cryptorchidism) whose testes were biopsied at the outer lateral face of the testis, five presented carcinoma in situ (CIS) in one testis. These testes were removed, serially sectioned, and examined by light microscopy. In order to evaluate whether only one or two biopsies are sufficient to diagnose CIS, before sectioning the testes four biopsies were taken at the anterior face, posterior face, superior pole, and inferior pole of the testis, respectively. Two of the five men had undergone orchiopexy in infancy and the testis contained tubules with Sertoli cells and isolated spermatogonia. CIS was also present in some tubules that were principally located near the rete testis. Of the four simulated biopsies, only that performed at the posterior face of the testis revealed CIS. The other three infertile men showed tubules with complete, although reduced, spermatogenesis, and tubules lined by Sertoli cells only. CIS was found in both types of tubules. These tubules with CIS formed lobules that extended throughout the testicular parenchyma. Most simulated biopsies performed in these three testes showed CIS. The average nuclear DNA content of CIS cells was about 4c in all testes. This content was similar both in tubules with complete spermatogenesis and in tubules with Sertoli cells only.

The numbers of Ap and Ad spermatogonia per unit section of the testis were calculated in autopsy specimens from young adults and elderly men without testicular pathology. The number of Ap spermatogonia decreased from the 6th decade of life, whereas that of Ad spermatogonia began to decrease in the 8th decade. Although it has been reported that Ad spermatogonia are more sensitive to noxious agents than Ap spermatogonia, the involution of Ap spermatogonia precedes that of Ad spermatogonia. These findings provide new information on concepts relating to the spermatogonia precedes that of Ad spermatogonia. These findings provide new information on concepts relating to the spermatogonial stem cell in man.

Testicular specimens from normal men and men with cryptorchidism (CR) or Klinefelter's syndrome (KS) were taken, processed for light microscopy, and stained with the avidin-biotin peroxidase complex method for immunohistochemical detection of testosterone. The Leydig cells were classified by their morphology (normal, multivacuolated, and pleomorphic Leydig cells) and by their staining affinity for anti-testosterone antibodies (T-, T+, and T++ cells), and the average numbers of each cell type for each group of testes were calculated. Normal testes showed morphologically normal interstitial Leydig cells (96.0 +/- 10 per cent) and multivacuolated Leydig cells (4.0 +/- 1 per cent). Cryptorchid testes showed normal Leydig cells (85.8 +/- 11 per cent) and multivacuolated Leydig cells (14.2 +/- 2.3 per cent). Men with KS showed normal Leydig cells (78.9 +/- 9.1 per cent), multivacuolated Leydig cells (9.2 +/- 1.2 per cent), and pleomorphic Leydig cells (11.0 +/- 1.8 per cent). The percentage of T++ cells was higher in normal testes (29.4 +/- 2.1 per cent) than in CR (11.4 +/- 2.2 per cent) and KS testes (6.3 +/- 0.7 per cent). This suggests reduced functional Leydig cell activity in CR and KS. Multivacuolated Leydig cells showed weaker immunostaining than did normal Leydig cells in all the testicular groups. No immunostaining was shown by pleomorphic Leydig cells. Intratubular Leydig cells were only found in CR and KS. Immunostaining was weaker in intratubular Leydig cells than in interstitial Leydig cells. This suggests that intratubular location reduces functional activity of Leydig cells.

No abstract

The numbers of each different cell type in the human seminiferous epithelium were determined throughout the 6 stages of the cycle in both semithin and ultrathin sections obtained from 15 young adult men with normal testicular histology. Up to 4 types of A spermatogonia (Ad, Ap, Al and Ac) were distinguished. In addition, the DNA nuclear content of seminiferous epithelium cells was determined on Feulgen-stained sections. Both Ad and Ap spermatogonia showed a 2c DNA content and were present in the 6 stages of the cycle, though their numbers decreased in stages III-V. Both Al and Ac spermatogonia showed a DNA content varying from 2c to 4c. Al spermatogonia were observed in stages III-V; their numbers plus those of Ad spermatogonia in these stages were similar to the numbers of Ad spermatogonia in the other stages lacking in Al spermatogonia. Ac spermatogonia appeared in stages III-VI and their numbers plus those of Ap spermatogonia in stages III-V were similar to the numbers of Ap spermatogonia in the other stages lacking in Ac spermatogonia. The results suggest that Ad spermatogonia are the stem cells. Some of them replicate their DNA; during this replication they appeared as Al spermatogonia. Al spermatogonia divide, giving rise to both Ad and Ap spermatogonia. Some Ap spermatogonia replicate their DNA; during this process they are transformed into Ac spermatogonia which divide, giving rise to B spermatogonia.

No abstract

A comparative morphologic study between the testes of 25 young adult men and 41 elderly men without testicular or related pathological conditions revealed the presence of multinucleate spermatids, showing up to 86 nuclei, in the testes of 3 of the elderly men. The formation of multinucleate spermatids is probably due to cell fusion, since the number of nuclei in these cells is not always 2" and multinucleate spermatocytes were uncommon. This anomaly seems to be another manifestation of an involutive process that also affects other cell types in the aging testis.