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M Nistal

Publications and source records attributed to M Nistal.

At least 163 records · Page 9Linked to original sources
PubMed1982

Hyperplasia and the immature appearance of Sertoli cells in primary testicular disorders.

Testicular biopsy specimens from adult patients affected with cryptorchidism, Klinefelter's syndrome, and Del Castillo's syndrome were examined by light and electron microscopy. The study revealed a high proportion of testes showing seminiferous tubules with hyperplasia of Sertoli cells (from 25 to 45 cells per transverse tubular section). These cells had an immature appearance and showed a pseudostratified distribution. The nucleus was round to ovoid and regular in outline, with a smaller nucleolus than that of mature Sertoli cells. The cytoplasm showed less development of the endoplasmic reticulum as well as of the secondary lysosomes and lipid droplets than that in mature Sertoli cells. Characteristic features of these immature Sertoli cells were abundant cytoplasmic microfilaments, elaborate interdigitations between adjacent cells, and extensive tight junctions, from basement membrane to lumen. In the cryptorchid testes, a more immature Sertoli cell was found to constitute the majority of the cells in hypoplastic zones. In Klinefelter's and Del Castillo's syndromes as well as in cryptorchid testes to a lesser degree, a transitional type of cell-from immature to mature-was also observed. These observations suggest that Sertoli cells in these primary testicular disorders reflect a congenital deficiency producing abnormal development.

Adolescent↗
PubMed1982

Histological, histochemical and ultrastructural variations along the length of the human vas deferens before and after puberty.

Vasa deferentia of 20 human adult males and 8 children were divided into four portions (proximal, middle, distal and terminal) for histological, histochemical and ultrastructural studies. The epithelium of the adult vas deferens was formed of columnar and basal cells. Three types of columnar cells were observed: (1) principal cells with PAS-positive cytoplasmic granules (lysosomes); (2) dark or pencil cells with a dark cytoplasm and nucleoplasm and cytoplasmic lipid vacuoles, and (3) mitochondrion-rich cells with numerous mitochondria similar to those of principal cells. All these cell types showed stereocilia and irregular convoluted nuclei, some of them containing granular, PAS-positive intranuclear inclusions. Principal cells were the most frequent cell type in the proximal portion but their number gradually decreased along the length of the vas deferens, while the proportion of both pencil cells and mitochondrion-rich cells increased. The muscular coat comprised three muscular layers: (1) inner longitudinal, (2) middle oblique (circular in the distal and terminal portions), and (3) outer longitudinal. The functional significance of regional variations is discussed. The infant vas deferens showed a columnar cell type only. However, cells either with numerous lysosomes or with numerous mitochondria were occasionally found. No regional variations were observed in the infant vas.

Adult↗
PubMed1982

Morphological and histometric study on the human Sertoli cell from birth to the onset of puberty.

In order to evaluate the changes in the number and form of the Sertoli cell from birth to the onset of puberty, a histometric and ultrastructural study was carried out in normal children. Ultrastructural findings revealed that immature Sertoli cells, present from birth to puberty, show round to elliptical nuclei, with regular outlines and small nucleoli. The cytoplasm exhibits well developed rough endoplasmic reticulum, prominent supranuclear Golgi complexes and vesicles at the luminal face; smooth endoplasmic reticulum was scarce. Histometric study revealed a progressive decrease in the Sertoli cell number per transverse tubular section as well as per unit area of testicular parenchyma, mainly from 3 years onwards. However, this decrease seemed to be the result of the progressive increase in the testicular volume as well as in the length and width of the seminiferous tubules, without change in the total Sertoli cell number per testis. This number may be considered constant, not only for adult testes but also for postnatal developing testes.

Aging↗
PubMed1980

Diffuse intratubular undifferentiated germ cell tumor in both testes of a male subject with a uterus and ipsilateral testicular dysgenesis.

A case of müllerian pseudohermaphroditism in a male subject with a uterus is described. The patient showed normal secondary sex characteristics as well as normal external genitalia, except for right cryptorchidism and a painful tumoral mass in the left testis. Examination of surgical specimens revealed a uterus attached to the left ductus deferens. Areas of seminoma and embryonal carcinoma were present in the left testis. In addition, there was a thin insufficiently collagenized albuginea that contained a cellular connective tissue resembling the ovarian stroma, as well as hypoplastic and atrophic seminiferous tubules. In the testicular parenchyma most of the seminiferous tubules located far away from the tumor possessed the atypical malignant germ cells characteristic of intratubular undifferentiated germ cell tumors. No spermatogenesis was seen. The right abdominal testis was atrophic and showed a normal albuginea. However, there was an undifferentiated germ cell tumor similar to that observed in the left testis. We describe the first case of a tumor in a scrotal testis of a male subject with a uterus. The occurrence of this tumor is discussed with regard to tubular dysgenesis present in both testes and supported by the intrinsically abnormal germ cells as well as by the immature Sertoli cells found in both testes.

Adult↗
PubMed1980

Histologic classification of undescended testes.

On the basis of testicular biopsy study in 203 patients and study of a second biopsy specimen from 27 of these patients, prepubertal undescended testes were classified into four categories according to the mean tubular diameter, the tubular fertility index, and the Sertoli cell index. Type I cases (testes with minimal lesions) were characterized by a normal mean tubular diameter and normal tubular fertility and Sertoli cell indexes or slight tubular hypoplasia. This group represented 26 per cent of the undescended testes. The corresponding lesions can be observed from two years of age onward and are probably acquired. After puberty normal spermatogenesis occurs. Type II cases (24 per cent of the undescended testes) included testes with marked germinal hypoplasia as well as slight or marked tubular hypoplasia and a normal Sertoli cell index. After puberty these testes develop a degree of marked hypospermatogenesis, maturation arrest, or Sertoli cells with only isolated spermatogonia and primary spermatocytes. In type III cases (testes with diffuse tubular hypoplasia) the mean tubular diameter and the tubular fertility and Sertoli cell index values were severely reduced. This group represented 33 per cent of the undescended testes, and after puberty most of them showed seminiferous tubules with exclusively adult Sertoli cells. Type IV testes (diffuse Sertoli cell hyperplasia) were associated with a nearly normal mean tubular diameter and variable tubular fertility index values and represented 17 per cent of all the undescended testes. After puberty Sertoli cells do not mature completely, and therefore in spite of the earlier tubular fertility index, the germinal cell line does not reach adult development. Although early orchiopexy prevents tubular fertility index and mean tubular diameter deterioration due to the noxious effects of temperature in type I testes, we believe that there is no such benefit in the other types. These patients may present only slight modifications in these indexes.

Adolescent↗
PubMed1980

Development of the endoplasmic reticulum during human spermatogenesis.

Human primary spermatocytes show a special development of the endoplasmic reticulum (ER). During the leptotene-zygotene stages a cisterna of ER surrounds a third or half of the nucleus closely associated with the nuclear envelope and connected with it. In the following stages of the first meiotic prophase, stacks of these cisternae appear closely related to the nucleus and show connections with other cytoplasmic cisternae which are free in the cytoplasm. In the secondary spermatocytes and spermatids, the number of ER cisternae joined to the nucleus decreases; in contrast, the number of free ER cisternae increases. Another peculiar differentiation of the ER, such as the annulate lamellae (AL), appears in the late stages of the first meiotic prophase in relation with the nuclear envelope. AL are conspicuous in secondary spermatocytes and spermatids. In spermatids, AL appear either joined to the nucleus or free in the cytoplasm, in close proximity to the Golgi complex. Finally, AL and other membranes of the ER are released in the cytoplasmic droplets of the maturing spermatids.

Cell Cycle↗
PubMed1980

[Leydig cell tumor with pseudoprecocious puberty (author's transl)].

Authors present a case of a Leydig cell testicular tumor in a boy aged three years with a six-month follow-up. This type of tumor which is usually hormone-producing has in children a virilizing effect giving signs of pseudoprecocious puberty. Hormonal tests before and after surgery are described as well as the histological study. The various possibilities of differential diagnosis, treatment and prognosis in the presence of a unilateral testis enlargement in a boy are commented.

Child, Preschool↗
PubMed1979

Ultrastructure of testicular biopsy from an XX male.

Ultrastructural study of testicular biopsy specimens from an XX male showed hyalinized seminiferous tubules and tubules containing only mature Sertoli cells. These cells possessed large lipid inclusions as well as microfilament bundles which were perpendicular to the basement membrane and parallel to one another. The basal lamina was thickened and composed of several parallel layers with myofibroblast layers between them. The interstitium showed nodular to diffuse Leydig cell hyperplasia. Four types of Leydig cells were found: 1) normal Leydig cells with crystals of Reinke; 2) cells with abundant microcrystalline inclusions as well as microfilaments and concentric cisternae of smooth endoplasmic reticulum; 3) vacuolated cells containing numerous large lipid droplets; 4) immature Leydig cells. The different ultrastructural abnormalities found in the Sertoli and Leydig cells might be considered as the histological expression of a tubular-interstitial dysgenesis which is reflected in the high levels of gonadotropins and low levels of testosterone.

Basement Membrane↗
PubMed1979

Testicular microlithiasis in 2 children with bilateral cryptorchidism.

Testicular microlithiasis, associated with bilateral cryptorchidism, is studied in 2, 6-year-old children. In case 1 autopsy revealed that 60 per cent of the seminiferous tubules contained completely calcified microliths. Similar mineralized concretions also were found in different areas of the cerebrum and cerebellum. In the testicular biopsy obtained from case 2, 30 per cent of the seminiferous tubules contained microliths showing different degrees of calcification. The study of such calcifications supports the hypothesis that the mineralization process occurs according to the following stages: 1) accumulation of cellular debris in the tubular lumen, 2) deposit of concentric rings of glycoprotein material surrounding the central core and 3) calcification of the glycoprotein lamellar material. The presence of similar concretion in the nervous system as well as the lung in other reported cases suggests that microlithiasis could be a systemic disease.

Calculi↗
PubMed1979

Histogenesis of human extraparenchymal Leydig cells.

From 64 consecutive autopsies of patients with neither testicular nor hormonal pathology, 26 showed extraparenchymal Leydig cells, located mainly in the epididymis and in the spermatic cord. The ultrastructural study of these specimens plus those obtained from 2 patients affected with functional testicular tumors leads to the following conclusions: (1) The origin of ectopic Leydig cells is not interstitial Leydig cells having infiltrated the testicular nerves and migrated along them towards ectopic locations. (2) The ectopic Leydig cells are considered to develop from undifferentiated precursor cells, located extraparenchymally, mainly inside and beside the testicular nerves. These precursor cells are similar to those observed in the testicular interstitium and have an ovoid shape and some cytoplasmic projections. The cytoplasm contains vesicles of smooth endoplasmic reticulum, lysosomes, lipid droplets and abundant microfilament bundles. The transformation from these cells into mature Leydig cells implies a progressive differentiation of the cytoplasmic components involved in steroid biosynthesis.

Adolescent↗
PubMed1978

Septate junctions between digestive vacuoles in human malacoplakia.

Typical septate junctions between digestive vacuoles in phagocytic cells of human malacoplakia are described in this paper. Evidence for a honeycomb pattern of hexagonal subunits is presented for their cleft material. Junctions were not observed between other organelles or in cells other than phagocytes. It is assumed that the septate junctions described here may reflect a pathological change in the organization of the membrane components of digestive organelles.

Adult↗
PubMed1978

Formaldehyde-induced appearance of septate junctions between digestive vacuoles.

Tissue biopsies from (1) some chronic inflammatory diseases, (2) a necrotic tumoral process, (3) normal human lymphatic ganglia, and (4) two congenital diseases of the adrenal cortex were selected for study. A block from each biopsy was fixed in glutaraldehyde-paraformaldehyde; a second block was fixed in 10% formaldehyde. In all cases septate junctions between digestive vacuoles did occur in phagocytic cells and some adrenal cortex cells fixed in formaldehyde. These junctions were similar to those reported recently for malakoplakia phagocytes. Consistently, they were not found to attach organelles other than lysosomes derivatives. Both phagocytes and adrenal cortex cells in the material fixed in glutaraldehyde-paraformaldehyde did not display adhesive specializations between digestive vacuoles. This suggests that the septate junctions described herein are artifactuous structures induced by formaldehyde. There is, however, a certain degree of specificity of cells having the capability of developing these septate junctions. It is assumed that the coating material of digestive organelles in phogocytes and some other cells would be responsible for both cell specificity and organelle specificity of the formaldehyde-induced septate junctions.

Adrenal Cortex↗