Biomedical subjects

R Paniagua

Publications and source records attributed to R Paniagua.

At least 181 records · Page 10Linked to original sources

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

Multivacuolated cells in human cartilage canals.

Light and electron microscopic examination of cartilage canals in 39 infants (from fetuses to 2 years of age) revealed the presence of multivacuolated cells in the connective tissue of the canals. These cells showed an irregular and electron-dense nucleus and cytoplasm; the latter was almost filled by large, irregular, membrane-bound vacuoles without or with hardly apparent content. Histochemistry revealed a weakly positive stain with periodic-acid-Schiff, oil-red-o and muramidase techniques in these cells which seem to be degenerated macrophages.

Bone and Bones↗

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↗

PubMed1985

Quantitative distribution of Ig-containing cells in the normal human intestinal mucosa.

The Ig-containing cell population of human intestinal mucosa (jejunum and ileum) has been quantitatively studied in 15 normal healthy adult men, by means of the peroxidase-antiperoxidase (PAP) method. The resolution obtained using the PAP method improves that obtained by fluorescence microscopy methods. The results obtained revealed that the number of Ig-containing cells progressively decreases from the basal portion of mucosa to the tip of the microvilli. Most Ig-containing cells were plasma cells; however, stained precursor cells (immunoblasts) were also observed in the human intestinal mucosa. The epithelial lining of the intestinal mucosa was also stained by anti IgA, anti IgG, anti IgM and anti IgE antibodies. Plasma cells were not seen to cross the epithelium. The absolute values, expressed as the number of Ig-containing cells per "mucosal tissue unit" (a 6-micron-thick and 500 micron wide block of tissue, including the mucosa at full height from the muscularis mucosa), and the relative percentages of the different Ig-containing cell population were the following: IgA: 86.71 +/- 15.58 cells (48.52%); IgG: 52.30 +/- 19.01 cells (29.6%); IgM: 21.44 +/- 8.23 cells (12.0%); IgE: 14.70 +/- 6.60 cells (8.22%), and IgD: 3.54 +/- 1.05 cells (1.9%). The number of lambda chains (76.29 +/- 24.38; 56.07%) were slightly more abundant than that of chi chains (59.77 +/- 11.93; 43.92%). The differences between the mean values of different Ig-classes were significant, and the differences between lambda and chi chains were also significant.

Cell Count↗

PubMed1985

Radiation-induced osteochondroma-like lesion in young rat radius.

To investigate the effects of radiation on the perichondrial groove of Ranvier in osteochondroma development, the external surface of the distal growth plate of the radius in both forelimbs of 30 ten-day-old rats was exposed to a single low dose of radiation (150 r), which was focused on the perichondrial groove. This induced the formation of a chondrocyte nest at the proximal external edge of the growth plate (five to nine days after irradiation). With advancing longitudinal growth of the bone, the chondrocyte nest occupied a diaphyseal position. At nine to 11 days the chondrocyte nest underwent endochondral ossification. At 13-15 days, this osteochondroma-like lesion began to regress with the disappearance of the chondrocyte nest. After 19-21 days, only an irregularly thickened cortical bone remains at the osteochondroma site. Although the possible role of the growth plate subjacent to the irradiated perichondrial groove must be taken into account, the continuity between the perichondrial groove and the osteochondroma, which is separated from the growth plate by the periosteal ring (bone bark), suggests that the perichondrial groove was involved in osteochondroma-like lesion development.

Animals↗

PubMed1984

Histogenesis of adenomatoid tumour associated to pseudofibromatous periorchitis in an infant with hydrocele.

An 18-month-old infant with recurrent congenital hydrocele presented with a mass in the caput epididymis. The tumour and several fragments of the tunica vaginalis were removed and studied by light and electron microscopy. The tumour showed the characteristic histological pattern of an adenomatoid tumour of mesothelial origin. The histological appearance of the tunica vaginalis was not uniform; some areas resembled the adenomatoid tumour to the epididymis, others exhibited histological and ultrastructural features of a haemangioma, whilst elsewhere, the two patterns were intermingled. Finally, areas of pseudofibromatous periorchitis with vascular proliferation and slit-like structures lined by mesothelial cells were recognized. These features suggest that the adenomatoid tumour originated from a localized reactive process with inflammation and vascular proliferation enclosing occasional slit-like structures originating from the mesothelial lining of the tunica vaginalis. Subsequent regression of vascular proliferation and inflammatory infiltration and continued mesothelial proliferation would give rise to the typical mesothelial pattern of adenomatoid tumour.

Epididymis↗

PubMed1984

Effects of postpuberal gonadectomy on the neurosensorial epithelium of the vomeronasal organ in the rat.

In the present report the effects of postpuberal gonadectomy on vomeronasal organ (VO) morphology were studied. Postpuberal gonadectomy induced in both male and female rats a decrement in the height of the epithelium and in the nuclear size of the bipolar neurons. These results show that the maintenance of neurosensorial normal morphology depend upon the activational effects of sex steroids.

Animals↗

PubMed1984

Testicular lymphangiectasis in Noonan's syndrome.

We describe a boy with testicular lymphangiectasis and Noonan's syndrome. Both testes showed seminiferous tubules with a reduced tubular diameter, containing few spermatogonia. The testicular interstitium exhibited a number of large, dilated lymphatic vessels forming irregular channels among the seminiferous tubules and surrounding them. Since there was no accompanying pathological condition to indicate an obstruction to the lymphatic flow at the level of the spermatic cord or in the regional lymph nodes, the abnormal development of testicular lymphatic vessels suggests a congenital malformation.

Child↗

PubMed1984

Leydig cell types in primary testicular disorders.

Ultrastructural study of testicular biopsy specimens from 67 adults with primary testicular disorders (Klinefelter's syndrome, XX male syndrome, Del Castillo's syndrome, and cryptorchidism) revealed the following four Leydig cell types: 1) normal or nearly normal Leydig cells with abundant smooth endoplasmic reticulum, mitochondria with tubular cristae, lipid droplets, and Reinke's crystals; 2) abnormally differentiated Leydig cells without either lipid droplets or Reinke's crystals but with altered mitochondria, concentric unfenestrated cisternae of smooth endoplasmic reticulum, and both paracrystalline and filamentous inclusions; 3) multivacuolated Leydig cells containing abundant lipid droplets; and 4) immature Leydig cells with scarce development of the smooth endoplasmic reticulum and mitochondria, and numerous cytoplasmic microfilaments. Abnormally differentiated Leydig cells might represent dysgenetic cells, whereas immature, normal, and vacuolated Leydig cells might represent three progressive stages in the Leydig cell cycle (undifferentiated, mature, and old involuting Leydig cells). An inverse correlation between the proportion of abnormal Leydig cells and testosterone levels was observed in each of these testicular disorders.

Adolescent↗

PubMed1984

Obstruction of the tubuli recti and ductuli efferentes by dilated veins in the testes of men with varicocele and its possible role in causing atrophy of the seminiferous tubules.

Hormone measurements, spermiograms and testicular biopsies studies were performed in young with varicocele. In addition, the testes and epididymides of 27 adults with varicocele were obtained from autopsies. Light and electron microscopic examination of biopsy and autopsy specimens revealed two types of lesions in testes with varicocele: 1) a diffuse lesion consisting of abnormal spermatozoa and spermatid morphology and sloughing of immature spermatozoa and spermatid; 2) focal lesion, distributed irregularly throughout the testicular parenchyma, affecting several small groups of seminiferous tubules. Each of these groups corresponded to a testicular lobule and showed different degrees of tubular atrophy, so that the focal lesions were distributed in a mosaic pattern. The testicular interstitium showed dilated veins and venules, and progressive collagenization. Some testes showed dilated veins in the rete testis, which compressed several tubuli recti and caused tubular atrophy in the seminiferous tubules opening into these tubuli recti. Other testes showed dilated young veins among the ductuli efferentes, and the rete testis channels appeared to be dilated. Among the different etiological mechanisms which have been suggested to for testicular lesions in varicocele, tubular obstruction at the level of either the tubuli recti or the ductuli efferentes might be responsible for lesions leading to testicular atrophy.

Adolescent↗

PubMed1984

Mast cells in the human testis and epididymis from birth to adulthood.

Mast cells are a constant cell-type in the connective tissues of the human testis and epididymis from birth to adulthood. Ultrastructural study shows that these cells are similar to those found in other connective tissues. Histometric studies revealed that the number of mast cells in the interstitium, mediastinum and albuginea of the testis as well as in the epididymal connective tissue increases slightly during infancy, decreases during childhood, and then increases again at puberty. Increases at puberty are particularly evident in both the testicular interstitium and the epididymis. During adulthood, the number of mast cells progressively decreases in all testicular and epididymal connective tissues. Changes in mast cell number may be related to changes observed in the development of testicular connective tissue which occurs primarily during infancy and puberty.

Adolescent↗

PubMed1984

The formation of annulate lamellae in the human Sertoli cell.

The formation of annulate lamellae (AL) has been studied in human Sertoli cells. Sertoli cells of infants did not show AL. Sertoli cells of 9- to 11-year-old boys showed incompletely circumferentially arranged cisternae of endoplasmic reticulum (ER), alternating with rows of vesicles, 200-300 nm in diameter, with a weakly osmiophilic content. The ER cisternae displayed both pores and attached ribosomes at a few sites. These membranous structures were also observed beside true concentrically arranged AL in pubertal Sertoli cells (11-13 years of age). Both types of membranous formations were continuous with parallel, rough endoplasmic reticulum cisternae (RER) that interconnected them. Adult Sertoli cells showed only AL, not the other peculiar membranous formation. These features suggest that the RER plus associated vesicles originate the AL in human Sertoli cells.

Adolescent↗

PubMed1984

Effects of exercise to exhaustion in rat myocardium. A stereological study.

Stereological methods under light and electron microscopy have been used to study the ventricular myocardium of rats exhausted by swimming exercise. The proportion of myocardial cell/interstitium diminishes with the exercise. This result is interpreted as a consequence of an intercellular edema which becomes more pronounced during the first hour of exercise. In the myocardial cells, neither the relative volume occupied by the myofibrils nor the number of mitochondria per cm3 undergoes significant changes. Nevertheless, a progressive increase of the relative mitochondrial volume is observed, specially during the first two hours of exercise. This increase may mainly be due to swelling of these organules, since a significant increase of the mean mitochondrial volume was noticed. These features confirm the observations made at ultrastructural level.

Animals↗