Biomedical subjects

M Nistal

Publications and source records attributed to M Nistal.

At least 127 records · Page 7Linked to original sources

PubMed1986

Diverticula of the ductus epididymis in men.

The histological study of epididymides obtained from autopsies (41 children, 7 young adults and 8 elderly men) and surgical specimens (10 young adults and 3 elderly men) revealed the presence of multiple diverticula in the cauda epididymis in all elderly men and in only 2 young adults (32 and 33 years old). The diverticula appeared as evaginations of the epithelial lining of the duct, disrupting the muscular coat and expanding into the surrounding connective tissue. The formation of epididymal diverticula seems to be an age-related process that might be caused by repeated increases in the intraluminal pressure in the cauda epididymis.

Adolescent↗

PubMed1986

Malignant fibrous histiocytoma in a child's hand.

A 3-year-old girl had a 4-month history of a tumor in her right hand. The tumor was located in the subcutaneous and soft tissues of the palm and the long, ring, and small fingers. Histologic studies showed a malignant fibrous histiocytoma that was confirmed by the ultrastructural study as having a fibroblastic and histiocytic origin. The long, ring, and small fingers were amputated. The postoperative course was normal, and 18 months later no recurrence or metastases were observed.

Child, Preschool↗

PubMed1986

Postsurgical focal testicular infarct.

A 74-year-old man was surgically treated owing to incarcerated right inguinal hernia. Following surgery, he developed a focal hemorrhagic testicular infarct localized in the anterior pole of the right testis. The cause of the infarct seemed to bei either thrombosis or compression by edema of the veins draining the testis.

Aged↗

PubMed1986

Idiopathic peritesticular fibrosis associated with retroperitoneal fibrosis.

A 32-year-old male who presented with idiopathic retroperitoneal fibrosis developed peritesticular fibrosis 4 years later. The lesion appeared as a diffuse, uniform thickening without a tendency to form nodules. Histologic examination revealed a densely collagenized tissue with scattered cells, consisting mainly of fibroblasts and plasma cells. Small blood and lymphatic vessels of the tumor showed luminal dilation and perivascular edema with inflammatory infiltrates. No other associated pathology was found in the patient. We suggest that peritesticular fibrosis in this patient may be due to lymphatic drainage obstruction caused by retroperitoneal fibrosis.

Adult↗

PubMed1986

Quantitative differences between variants of A spermatogonia in man.

The area of cytoplasm, nucleus, nucleolus and mitochondria, as well as the elongation and irregular outline of the nucleus were determined, on electron micrographs by using an image analyser, for Ap (pale), Ad (dark with intranuclear vacuole), Ad-like (dark without intranuclear vacuole), Ac (cloudy) and Al (long) human spermatogonia. Ap and Ac spermatogonia had larger nucleus, larger nucleolus, and more cytoplasm than did Ad, Ad-like, and Al spermatogonia. In addition, the nuclei of Ap and Ac spermatogonia were more spherical and had a more distinct outline.

Adult↗

PubMed1986

Multinucleate spermatids in aging human testes.

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 2n 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.

Acrosome↗

PubMed1986

Changes in the connective tissue and decrease in the number of mast cells in the testes of men with alcoholic and non-alcoholic cirrhosis.

The testicular connective tissue of patients with alcoholic and non-alcoholic cirrhosis was studied by Picrosirius staining for collagen fibres and electron microscopy, and then compared with the connective tissue of normal testes. Under polarized light, the interstitial connective tissue in the testes of patients with alcoholic and non-alcoholic cirrhosis exhibited a green birefringence which did not appear in normal testes, and the orange birefringence characteristic of the tunica propria in the testes of both cirrhotic and normal males was less developed in cirrhosis. This suggests that a connective tissue, consisting of smaller and less ordered collagen fibre bundles than those in the tunica propria is formed in the testicular interstitium of cirrhotic males, and the collagen fibre bundles of the tunica propria are less developed than in normal testes. The appearance of connective tissue was associated with a decrease in the number of mast cells in the testes of cirrhotic males suggesting the involvement of mast cells in the synthesis, packing, and organization of collagen fibres. The cause of the decrease in mast cell numbers may be related to hormone alterations, in particular testosterone deficiency.

Adult↗

PubMed1986

Ultrastructure of Leydig cells in human ageing testes.

Ultrastructural study of Leydig cells in elderly men revealed the following Leydig cell types: (1) ultrastructurally normal Leydig cells (46.2%); (2) Leydig cells either with multiple cytoplasmic or intranuclear Reinke crystals or with numerous para-crystalline inclusions (6.1%); (3) multivacuolated Leydig cells with the cytoplasm almost filled by lipid droplets (16.7%; (4) dedifferentiated Leydig cells with poor development of agranular endoplasmic reticulum and mitochondria, and increased amounts of lipofuscin granules (22.3%); and (5) bi- or trinucleate Leydig cells (8.7%) showing either a normal (2.8%) or dedifferentiated (5.9%) cytoplasm. These results suggest an involution of Leydig cells with advancing age. A correlation between the proportion of altered Leydig cells and the decrease in testosterone and increase in luteinising hormone levels could be observed.

Adult↗

PubMed1986

Testicular toxoplasmosis in two men with the acquired immunodeficiency syndrome (AIDS).

Testicular infection due to Toxoplasma gondii in two young men with the acquired immunodeficiency syndrome manifested as a multifocal necrotizing lesion of the testicular parenchyma. At the periphery of the necrotic area were inflammatory infiltrates consisting mainly of eosinophilic leukocytes. The Toxoplasma organisms were mainly found within the necrotic seminiferous tubules, where they were identified with periodic acid-Schiff or May-Grünwald-Giemsa stains and by electron microscopy. The histologic pattern of this orchitis is characteristic and should be suspected in patients with severe disorders of the immune response.

Acquired Immunodeficiency Syndrome↗

PubMed1986

[Mediastinal teratomas. A clinical and pathologic study of 3 pediatric cases].

Mediastinal teratomas are reported in three children. Two cases: an eighteen-month-old female and a twelve-years-old female, were diagnosed of mature cystic teratoma. Third patient was a twelve-year-old male with an immature mediastinal teratoma. All tumors were located in anterior mediastinum. Mediastinal mature cystic teratomas were completely excised and their evolution were favourable. However, immature mediastinal teratoma infiltrated lung parenchyma and great blood vessels; in this case only a biopsy was performed. This patient died a month after surgical procedure. Clinical, radiological and pathological findings of mediastinal teratomas in childhood are commented. Prognostic factors and evolution of different histological types of mediastinal teratomas are evaluated.

Child↗

PubMed1985

Quantitative and ultrastructural study of Leydig cells in Klinefelter's syndrome.

This ultrastructural and quantitative study of Leydig cells in Klinefelter's syndrome has been performed using the entire testes obtained from four autopsies plus testicular biopsies from 20 patients. The total Leydig cell volume per testis in Klinefelter's syndrome was similar to that of control testes. However, the total number of Leydig cells per testis was significantly lower in the patients with Klinefelter's syndrome than in the controls. This may be attributed to the Leydig cell hypertrophy that these patients underwent. In patients with Klinefelter's syndrome the average volume of each Leydig cell was significantly higher than that of the controls. Electron microscopic findings revealed that besides ultrastructurally normal Leydig cells there were three other morphologically abnormal Leydig cell types: abnormally differentiated cells; multivacuolated cells; and immature Leydig cells. The ultrastructurally normal Leydig cells were probably the cells principally responsible for testosterone biosynthesis in these patients, whereas the other Leydig cell types were probably barely or not at all functional. The hypertrophy showed by the ultrastructurally normal Leydig cells may be interpreted as an attempt to increase testosterone production.

Adult↗

PubMed1985

Histologic lesions in undescended ectopic obstructed testes.

Testicular biopsies and hormone studies have been carried out on 229 children with unilateral (181) or bilateral (48) undescended ectopic obstructed testes not associated with other pathologic conditions. With regard to the histologic lesions, the obstructed testes may be classified into four types: (1) testes with minimal lesions (40.1%), showing slight reduction in both mean tubular diameter (MTD) and tubular fertility index (TFI); (2) testes with marked germinal hypoplasia (33.6%), showing slight or marked reduction in MTD and marked reduction in TFI; (3) testes with diffuse tubular hypoplasia (19.1%), showing severe reduction in MTD, marked or severe germinal hypoplasia, and normal or decreased Sertoli cell number per transverse tubular section (SCI); and (4) testes with Sertoli cell hyperplasia (7.2%), showing slightly decreased MTD, marked or severe germinal hypoplasia, and marked increased in SCI. These lesions are similar to those found in cryptorchid testes, although the proportion of testes with type III and IV lesions (the most severe) is lower than in cryptorchid testes. Hormone assays revealed normal basal gonadotropin and testosterone levels. The response of gonadotropins to gonadotropin-releasing hormone stimulation and the response of testosterone to human chorionic gonadotropin stimulation were normal or slightly reduced.

Child↗

PubMed1985

Cystic intra-abdominal testicular torsion in an infant.

We report on a 3-month-old infant with cystic intra-abdominal testicular torsion. He presented with abdominal distension and pain. Physical examination showed a movable, well delineated mass in the right iliac and lumbar fossae. Exploration revealed that the mass was connected to the abdominal aorta by a thin vascular cord that was twisted before reaching the mass. The histological study showed that the mass corresponded to a testis with cystic formations. The testicular parenchyma was necrotized, although isolated seminiferous tubules were found. The cystic cavities were filled by hematic and necrotic material, and exhibited no epithelial lining. A fibrous layer in continuity with interstitial hemorrhage surrounded the cysts. The twisted vascular cord corresponded to a spermatic cord with dilated pampiniform plexus veins. The differential diagnosis and the etiopathogenesis of the lesion are discussed.

Abdomen↗

PubMed1985

Primary neuroectodermal tumour of the testis.

A 51-year-old male presented with metastasis of a small cell carcinoma of unknown origin in a right inguinal lymph node. Clinical and laboratory studies failed to locate the primary tumour. After three years, a swelling appeared in the right testis, which was removed. Histological examination revealed a proliferation of small tumour cells forming irregular masses or nests that occupied most of the testicular parenchyma. At the periphery of the testicular parenchyma a few seminiferous tubules could be observed, showing a low and incomplete seminiferous epithelium and numerous tumour cells in the lumen. Most of the tumour cells showed a euchromatic nucleus with small nucleoli and scanty cytoplasm. Among these cells, larger binucleate or trinucleate cells as well as small cells with pyknotic nuclei were also observed. Mitoses were numerous. Electron microscopy revealed some tumour cells with 80 to 100 nm vesicles containing electron-dense granules. Some cells displayed dendrite-like prolongations with numerous intermediate filaments and electron-dense vesicles. This tumour is compatible with a primary neuroectodermal tumour of the testis.

Cytoplasmic Granules↗

PubMed1985

Ultrastructural changes in Sertoli cells in ageing humans.

Ultrastructural study of seminiferous tubules in ageing men revealed a varying degree of spermatogenetic arrest associated with changes in the Sertoli cells. Approximately half of the Sertoli cells showed a normal mature nuclear appearance although the cytoplasm was altered morphologically. These cells were classified as containing abundant lipid droplets (30%), containing large cytoplasmic vacuoles filled with an amorphous material similar to that in the tubule lumen and surrounded by junctional specializations (8%), multinucleated Sertoli cells (4%), or Sertoli cells with numerous mitochondria displaying tubular cristae (2%). The remaining 7% of Sertoli cells had an immature nuclear appearance and sparse development of the cytoplasmic organelles; these cells probably represent dedifferentiated Sertoli cells. Although individual differences were marked, a correlation between the increase in gonadotrophin levels and changes in both germ cell development and Sertoli cell structure was observed.

Adult↗

PubMed1985

Testis, epididymis, and spermatic cord in elderly men. Correlation of angiographic and histologic studies with systemic arteriosclerosis.

Autopsy specimens of the testes, epididymides, and spermatic cords from 20 adult young and 60 elderly men were studied by angiographic and histologic techniques. Testicular alterations in elderly men were correlated to the degree of aortic atheromatosis. Elderly men without manifest atheromatosis showed no lesions. Elderly men with slight atheromatosis showed a spiculated outline of the testicular artery and intraparenchymatous zones with scarce filling of small arteries. These zones exhibited peritubular and interstitial fibrosis. Elderly men with severe atheromatosis showed large zones of the testicular parenchyma with scarce filling of centrifugal and centripetal arteries that exhibited fibrosis of the tunica intima and lumen reduction; the testicular parenchyma appeared fibrosed with sclerosed tubules. Epididymal lesions were parallel to testicular lesions. These results suggest that systemic arteriosclerosis is involved in the decline of testicular function with age.

Adult↗

PubMed1985

Ectopic seminiferous tubules in the tunica albuginea of normal and dysgenetic testes.

The histological study of testes obtained from 453 autopsies and 245 biopsies revealed seminiferous tubules in the testicular tunica albuginea of 9 children. Affectation was always unilateral. Three of these testes were associated with müllerian structures and were dysgenetic, showing a thin, insufficiently collagenized tunica albuginea, similar to the ovarian stroma. The other 6 testes corresponded to: 4 normal children, 1 child with idiopathic male pseudohermaphroditism without Müllerian structures, and another with unilateral inguinal cryptorchidism. In these 6 testes the tunica albuginea was histologically normal. These results suggest that the presence of seminiferous tubules in the tunica albuginea is not sufficient to diagnose testicular dysgenesis. Such a diagnosis may only be indicated if the tunica albuginea also exhibits the other characteristic features of dysgenetic testes.

Adolescent↗

PubMed1985

Presence of ribonucleoproteins and basic proteins in the nuage and intermitochondrial bars of human spermatogonia.

Ultrastructural cytochemical study of the nuage in the human adult testis revealed that this structure was a cytoplasmic fine fibrillar electron-dense mass, similar to the chromatoid body of spermatids, in all spermatogonial types and spermatocytes. The nuage was often observed in relation with the nucleus or mitochondria. Cytochemical techniques showed staining affinity of the nuage for both ethanolic phosphotungstic acid and ethylene diamine tetra-acetic acid. The intermitochondrial bars were also stained with the two procedures. The results suggest that the nuage originates from the nucleus and migrates to the cytoplasm through nuclear pores, giving rise to the intermitochondrial bars.

Histocytochemistry↗