The postnatal development of the junctional complexes of hamster Sertoli cells as revealed by HRP and freeze-fracture.

The development of the Sertoli cells occluding junctions was investigated in testes from 5-, 10-, 15-, 20- and 30-day-old hamsters after intravascular administration of horseradish peroxidase (HRP) and by freeze-fracture. Up to the 15th day, HRP could be detected in the interstitial spaces and the central area of testicular cords. On day 20, the tracer reached the lumen of some tubules but in others it was retained at the periphery of the seminiferous epithelium, thus suggesting an asynchronous formation of the blood-testis barrier along the length of the tubules. Gap junctions associated with short rows of particles were found on freeze-fracture replicas from 5-day-old animals. Later on, a decrease in the frequency of gap junctions and a corresponding increase in the number of tight junctions was observed. Beyond the 20th day, tight junctions became morphologically and physiologically similar to those of mature animals, indicating establishment of the blood-testis barrier.

Morphological findings in varicocele: an ultrastructural study of 30 bilateral testicular biopsies.

A systematic study of a series of thirty bilateral biopsies of testes was performed using electron microscopy. Observations showed how frequently there were bilateral changes within the Sertoli cells. These included a sometimes extensive vacuolization of the endoplasmic reticulum which may cause germ cells to exfoliate. Bilateral vascular lesions including modifications of the capillary endothelium which becomes thick and rich in pinocytotic vesicles and arteriolar spasms with an increase in number of microfilaments in the endothelial cells were constantly observed.

[Structural anomalies in disorders human of sperm motility in 60 cases of asthenospermia]. / Les anomalies de structure dans les troubles de la mobilité du spermatozoïde humain a propos de 60 cas d'asthénospermie.

The morphological study of sperm cells was carried out in sixty cases of proven asthenospermia. In fifteen of the cases, structural abnormalities, related to impaired cell mobility, have been shown, namely when spermatozoa, which were immobile in a large majority, presented short tails or characteristic ultrastructural abnormalities of the axonemal complex.

High resolution radioautographic study of newly formed protein in striated muscle with emphasis on red and white fibres.

The elaboration and distribution of newly formed proteins in the striated muscle of 21-day-old mice were investigated by quantitative radioautography at intervals between 2 and 240 min after intravenous injection of tritiated leucine. In radioautographs, the localization and the relative label concentration were comparatively estimated for the different components of mitochondria-rich fibres, in particular of red fibres, from the tibialis anterior muscle and of mitochondria-poor fibres from the oesophageal muscle. As early as 2 min after injection, radioactivity was detected over the nucleus, the polysome-rich sarcoplasm, the A and I bands, the Z lines, and the mitochondria in the two fibre types. Label localization did not change with time. The relative label concentration increased similarly in the polysome-rich sarcoplasm and the A and I bands of both fibre types within 30 min after injection, a confirmation that biosynthesis of myofibrillar proteins takes place rapidly. In each case, concentration was higher in the Z lines than in the I bands, and higher in the I bands than in the A bands, thus showing "in vivo" that the rates of synthesis of sarcomere protein components are not uniform. However, the relative label concentration was found to be higher in the Z lines of mitochondria-poor fibres than of mitochondria-rich fibres: this suggests that a higher synthetic rate of Z line protein, and probably of alpha actinin, is characteristic of the first type. Inversely, the concentration was higher in the mitochondria of mitochondria-rich fibres. This lead to the belief that high rate of protein synthesis in these organelles may account for the high rate of label incorporation into this type of fibre.

[Radioautographic study of the incorporation sites and migration pathways of tritiated leucine in aortic myocytes]. / Etude radioautographique des sites d'incorporation et des voies de migration de la leucine tritiée dans le myocyte aortique.

The synthesis and fate of newly-formed proteins in the aortic media cell of 21 days old mice were investigated by quantitative radioautography after intravenous injection of tritium-labelled leucine. At 2 mn after injection, radioactivity was detected over the polysomes, the myofilaments and the rough endoplasmic reticulum, indicating that sedentary and exportable proteins were synthesized. It remained high on the sarcoplasm rich in polysomes and the myofilaments until 240 mn. However, the peak of radioactivity occured at 20 mn in the sarcoplasm and at 30 mn in the myoplasm. Therefore, the elaboration of sedentary proteins seems preponderant and they participate noticeably in the formation of the contractile apparatus. At 10 mn, radioactivity appeared in the Golgi apparatus at a high level, while increasing until 30 mn in the rough endoplasmic reticulum. By 20 mn, the labelling intensified along the plasma membrane and over the connective time lamellae. It occured earlier and was more intense on collagen fibrills than elastin, suggesting that the biosynthesis of elastin takes place more slowly. Thus, the pattern of two different metabolic pathways, as defined generally for the two types of proteins--sedentary and exportable--is true for the aortic media cell.

[The testis in a 46, XX male. Apropos of an ultrastructural examination]. / Le testicule chez l'homme 46 XX. A propos d'une observation ultrastructurale.

The ultrastructure of a testicular biopsy was carried out in a man with 46 XX chromosomes who had a masculine phenotype and in whom the hormone levels showed that the interstitial tissue of the gland was functioning well. Observations showed that the exocrine appearance of the testis was comparable to that described in Klinefelter's syndrome, namely germinal aplasia with invasion by Sertoli cells. On the other hand the interstitial glandular tissue showed morphological characteristics associated with normal androgen activity, which is unusual to find in Klinefelter's syndrome. Lipid inclusions, pigmentation and Reinke cristalloids were found. The cytogenetic techniques that happened to be used did not manage to show up even a small fragment of the Y chromosome. Various theories have been considered to explain the constitution of such a phenotype with this chromosome abnormality.

Protein turnover in the smooth muscle cell of the aortic tunica media as visualized by radioautography.

The turnover of newly formed proteins in the aortic myocyte was studied by means of quantitative light and electron microscopic radioautography. Adult and young mice were sacrificed at long intervals between 4 h and 108 days after one injection of tritiated leucine. The results showed that secretory activity, important in the post-natal myocyte, persists noticeably in the mature myocyte. The similarity in sedentary protein turnover, noted in both the thoracic and abdominal aortic segments of the adult and young animals, seems to be expressed by the same labelling patterns of the myoplasma. Turnover of exportable protein, which varies with age and anatomical level, appears to be related to the higher rate of elastin synthesis in the thoracic aorta of the young animal.