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Biomedical subjects

M Nistal

Publications and source records attributed to M Nistal.

At least 109 records · Page 6Linked to original sources
PubMed1988

Congenital Leydig cell hyperplasia.

The testes and epididymes collected at autopsy from 21 newborns showed apparent Leydig cell hyperplasia which was studied by light and electron microscopy. Twelve newborns were the sons of diabetic mothers, two had undergone rhesus isoimmunization, two were twins of a non-diabetic mother, three had Beckwitz-Widemann's syndrome, and two had leprechaunism. In the first two groups the placentas were also collected and studied. All the testes showed normal seminiferous tubules and diffuse Leydig cell hyperplasia in the testicular interstitium. In addition one son of a diabetic mother and another with Beckwitz-Widemann's syndrome presented multiple Leydig cell nodules in the mediastinum testis and epididymis. The number of Leydig cells per unit area of the testis was calculated on histological sections stained with the peroxidase-anti-peroxidase method for the detection of testosterone. These numbers varied from 1.4 to 3.2 times those found in age-matched controls, except for the two testes with nodular hyperplasia in which the increase in Leydig cells was even greater. The differential diagnosis between Leydig cell hyperplasia, ectopic adrenal cells and leydig cell tumour is discussed. It is proposed that the cause of congenital Leydig cell hyperplasia might be related to placental secretion of human chorionic gonadotrophin.

Autopsy↗
PubMed1988

Inflammatory malignant fibrous histiocytoma of the spermatic cord.

A 74-year-old man with a right inguinal hernia since 15 years was admitted because of inguinal pain and enlarged ipsilateral testis. Surgical exploration revealed a hernia with an empty hernial sac and three tumoral masses in the spermatic cord. Tumoral masses, spermatic cord, and testis were removed. Histological examination of the tumoral masses revealed a malignant inflammatory fibrous histiocytoma. The tumor infiltrated the vas deferens, pampiniform plexus, and adjacent adipose tissue. Epididymis and testis were not infiltrated. Three years after treatment with radiotherapy no recurrence or metastases have been observed.

Aged↗
PubMed1988

Juvenile granulosa cell tumor of the testis.

Juvenile granulosa cell tumor occurred in a newborn. The tumor presented with testicular torsion, and no malformations were observed. The karyotype was normal. The occurrence of initial tumoral lesions in the seminiferous tubules located in the vicinity of the tumor suggests that the tumor originated from immature Sertoli's cells. To our knowledge, this is the tenth case reported in a newborn and the second associated with testicular torsion.

Granulosa Cell Tumor↗
PubMed1987

Quantification of cell types throughout the cycle of the human seminiferous epithelium and their DNA content. A new approach to the spermatogonial stem cell in man.

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.

Adult↗
PubMed1987

Hyperplasia of spermatic cord nerves: a sign of testicular absence.

The comparative histologic study of the spermatic cord in the absence of testis, epididymis-testis separation, and normal development of both testis and epididymis, revealed that there is nerve trunk hyperplasia and hypertrophy in absence of the testis. This finding may greatly aid the diagnosis of testicular absence in the management of impalpable testes.

Cryptorchidism↗
PubMed1987

Testicular involution in elderly men: comparison of histologic quantitative studies with hormone patterns.

An endocrinologic and quantitative histologic study was carried out in 64 elderly men who underwent orchidectomy owing to prostatic carcinoma. The men were classified into age groups (decade of life), and each group was subdivided into group A (testes with complete spermatogenesis in most tubules) and group B (testes showing maturation arrest of spermatogenesis in most tubules). Up to 80 years of age, men of group A showed hormone levels and testicular parameters similar to those of young control men. From 50 to 60 years of age, men of group B showed a significant decrease in testicular volume, tubular volume, tubular length, number of germ cells, Sertoli cells and Leydig cells per testis, and plasma testosterone levels, whereas the tunica propria thickness and plasma levels of both follicle-stimulating hormone and luteinizing hormone were increased.

Adult↗
PubMed1987

Correlation between spermatozoon numbers in spermiogram and seminiferous epithelium histology in testicular biopsies from subfertile men.

A new method for correlating testicular biopsies and spermiograms is proposed. The number of spermatogonia, round spermatids, and elongated spermatids per cross-sectioned tubule were calculated in the testes from 33 subfertile men and in 10 control normal testes. According to these quantitations, the testes in subfertile men were classified as testes with maturation arrest of spermatogenesis, testes with hypospermatogenesis, and testes with associated maturation arrest and hypospermatogenesis. A power regression curve correlating the number of elongated spermatids and sperm numbers in the spermiogram was performed.

Adult↗
PubMed1987

Hemangiopericytoma of the trachea.

Malignant neoplasms of the trachea are rare lesions, with no more than 400 cases documented in the literature. Only three tracheal hemangiopericytomas have been reported. We present the fourth case of such a tumour occurring in the trachea. After the first surgical resection the tumour recurred twice in a period of 10 months. The last cervicotomy performed for local recurrence showed wide cervical and mediastinal involvement of the tumour, not resectable surgically. Emphasis is placed on the surgical, pathologic and ultramicroscopic findings.

Biopsy↗
PubMed1987

Seminiferous tubule involution in elderly men.

The observation of different types of seminiferous tubules (from tubules with normal spermatogenesis to sclerosed tubules) in aging human testes points to the progressive stages of tubular involution in elderly men. The tubules with hypospermatogonesis (reduced number of elongated spermatids) show numerous morphological anomalies in the germ cells, including multinucleated cells. Abnormal germ cells degenerate, causing Steroli cell vacuolation. These vacuoles correspond to dilations of the extracellular spaces resulting from the premature exfoliation of germ cells. Degenerating cells that are phagocytized by Sertoli cells lead to an accumulation of lipid droplets in the Sertoli cell cytoplasm. The loss of germ cells begins with spermatids, but progressively affects the preceding germ cell types, and tubules with maturation arrested at the level of spermatocytes or spermatogonia are observed. Simultaneously, an enlargement of the tunica propria occurs. This leads to the formation of sclerosed tubules, some of which display a low seminiferous epithelium consisting of a few cells--including lipid-loaded Sertoli cells and both Ap and Ad spermatogonia--and others, showing complete sclerosis, are devoid of seminiferous epithelium. The development of tubular involution is similar to that reported after experimental ischemia, which also seems to cause nonspecific effects on the testis such as multinucleate cells, vacuoles, and increased lipids in Sertoli cells.

Adult↗
PubMed1987

Tubular embryonal remnants in the human spermatic cord.

The spermatic cords (SCs) obtained from: (a) autopsies of 67 adults and 50 children; (b) 3 fetuses; (c) 12 surgical specimens from 9 adults and 3 children with testicular tumors, and (d) 26 surgical specimens (14 adults and 12 children) with diagnosis of SC cysts, were studied by light microscopy. The histological study revealed the occurrence of tubular embryonal remnants (TERs) in 19 autopsied adults, 14 autopsied children, 3 fetuses, 2 surgical specimens (1 adult and 1 child) owing to testicular tumors, and 6 surgical specimens with diagnosis of SC cysts. The TERs were found in the low, middle or high thirds of the SC and consisted of a cuboidal or columnar, often ciliated epithelium surrounded by connective tissue. In the 3 fetuses and in 3 autopsied children renal glomeruli were found in close relation with the TERs. In 2 cases of SCs showing cysts and TERs both structures contained spermatozoa. The histological pattern of the TERs suggest that they are wolffian derivatives which might give rise to SC cysts.

Adult↗
PubMed1987

Histological classification of spermatic cord cysts in relation to their histogenesis.

Light microscopy study of spermatic cord cysts in 26 men revealed three different histological patterns. First, cysts of probable mesothelial origin (14 cases) with an unilocular aspect: their epithelial cells showed poor cohesion and often appeared sloughed; subepithelial hyalinization or fibrin deposits were frequent. Second, cysts of probable embryonal (mesonephric) origin (8 cases): they were usually multilocular cysts and their epithelial cells showed great cohesion: zones of ciliated columnar epithelium associated with embryonal remnants displaying a similar epithelium were often found; the embryonal remnants and the cyst lumen contained spermatozoa in 2 cases. Third, cysts of doubtful origin (4 cases) showing abundant inflammatory infiltrates, which had destroyed the epithelium; the unilocular pattern observed in 3 cases suggests a mesothelial origin for these cysts, while the multilocular pattern and presence of embryonal remnants in the other case suggest an embryonal origin.

Adolescent↗
PubMed1987

Changes in the lipid inclusion/Sertoli cell cytoplasm area ratio during the cycle of the human seminiferous epithelium.

The area occupied by Sertoli cell lipid inclusions--electron-lucent lipid vacuoles (LLV) and electron-dense lipid droplets (DLD)--at each stage of the cycle of the seminiferous epithelium was measured on electron micrographs in young adults and elderly men, and expressed as the ratio "area occupied by lipid inclusions/area occupied by the Sertoli cell cytoplasm". For LLV this ratio increased from stage I to stage III, and decreased from stage IV to stage VI in young adults. These results suggest that the development of LLV is synchronized with the spermatogenic process: the residual bodies released in stages I and II are phagocytized by Sertoli cells and transformed into LLV; the amounts of LLV decrease in the subsequent stages of the cycle and increase again when new residual bodies appear. In elderly men the ratio LLV/Sertoli cell cytoplasm was 1.9-2.9 times higher than in young adults at each stage of the cycle. This increase may be related to the increased germ-cell degeneration observed in ageing testes, DLD were less abundant than LLV and the DLD/Sertoli cell cytoplasm ratio did not undergo cyclic changes in young adults or elderly men.

Adult↗
PubMed1987

Presence of basic proteins and ribonucleoproteins in the neck region of human spermatids and spermatozoa.

The ultrastructural cytochemical study of the neck region of human spermatids and spermatozoa revealed that, besides the centrioles, the basal plate, the lateral cupshaped junction body and the annulus material showed affinity for both ethylene diamine tetra-acetic acid (EDTA) stain (a preferential staining method for ribonucleoproteins) and ethanolic phosphotungstic acid (PTA) stain (for cellular localisation of basic proteins). The capitulum and the surface of the striated columns were also stained with ethanolic PTA. The chromatoid body and annulate lamellae-which were frequently encountered in the neck region--stained with both EDTA and ethanolic PTA techniques. This suggests a possible participation of the chromatoid body and annulate lamellae in the formation of the neck region structures.

Adult↗
PubMed1986

A quantitative morphological study of human Leydig cells from birth to adulthood.

Human testicular specimens were obtained from biopsies and autopsies covering the period from birth to adulthood. The number of testosterone-containing Leydig cells was determined using the peroxidase-anti-peroxidase method. This number decreased markedly from 3-6 months of age to the end of the first year of life and, up to 6 years of age, only a small number of testosterone-containing cells was found. From 6 years onwards the number of Leydig cells progressively increased. Ultrastructural examination revealed four types of Leydig cells: fetal-type Leydig cells (from birth to 1 year of age) with round nuclei, abundant smooth endoplasmic reticulum and mitochondria with tubular cristae; infantile-type Leydig cells (from birth to 8-10 years of age), showing a multilobated nucleus, moderately abundant smooth endoplasmic reticulum, some lipid droplets and mitochondria with parallel cristae; prepubertal, partially differentiated Leydig cells (from 6 years of age onwards) with regularly-outlined round nuclei, abundant smooth endoplasmic reticulum, mitochondria with tubular cristae, and some lipid droplets and lipofuscin granules; and mature adult Leydig cells (from 8-10 years of age onwards). The ultrastructure of the infantile-type Leydig cells and the lack of delay between the disappearance of the fetal-type Leydig cells and the appearance of infantile-type Leydig cells suggest that fetal-type Leydig cells give rise to the infantile-type Leydig cells. Before puberty, myofibroblast-like precursor cells differentiate into the prepubertal, partially differentiated Leydig cells, which complete their differentiation into the adult Leydig cells.

Adolescent↗
PubMed1986

Mitosis in adult human Leydig cells.

The ultrastructural study of testicular biopsies from 87 adult men revealed mitosis in two mature Leydig cells, each from a different man. The men showed normal hormone levels and had received no previous chemotherapy or hormone treatment, nor had they been exposed to known toxic agents. The presence of mitotic Leydig cells suggests that differentiated Leydig cells may divide and contribute either to the increase in the number of Leydig cells or to the formation of multinucleate Leydig cells.

Adult↗
PubMed1986

Ultrastructural observations on nucleoli and related structures during human spermatogenesis.

The ultrastructural study of nucleoli and ribonucleoprotein-containing structures in human seminiferous tubules revealed that the nucleoli of spermatogonia, spermatocytes and Sertoli cells exhibited a tripartite structure consisting of: a fibrillar center, a compact granular portion, and a reticular portion containing both pars fibrosa and pars granulosa. The nucleoli of primary spermatocytes showed a developed reticular portion. At pachytene, the compact granular portion enlarged and lost its connection with the fibrillar center and the reticular portion which decreased in size. This suggests a nucleolar segregation similar to that of ovocytes in many species. Two similar developmental stages of nucleoli were observed in spermatogonia. In addition to nucleoli, there were other ribonucleoprotein-containing structures such as intranuclear closely-packed granules in Ap spermatogonia, coarse granules in the chromatin rarefaction zone of Ad spermatogonia, the nuage and Lubarsch crystals of spermatogonia, the chromatoid body of spermatids, the annulate lamellae of both spermatids and Sertoli cells, and many structures of the spermatid neck region.

Adult↗