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Biomedical subjects

M Nistal

Publications and source records attributed to M Nistal.

At least 145 records · Page 8Linked to original sources
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↗
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

Morphological and histometric study of human spermatogonia from birth to the onset of puberty.

Normal human testes obtained at autopsy from 99 male subjects whose ages ranged from a few days after birth to 13 years of age were studied by light and electron microscopy. Besides fetal and transitional spermatogonia, types Ap, Ad, and B spermatogonia, similar to those of the adult testis, are found. The number of spermatogonia per 10 cross sectioned tubules decreases slightly from birth (15.3 +/- 1.2) to 3 years of age (12.1 +/- 1.0), and increases afterwards until 8 years of age (28.2 +/- 2.6). After a brief decrease between the ages of 8 and 9, it increases markedly until 12-13 years of age (49.7 +/- 4.6). The number of fetal and transitional spermatogonia per 10 cross sectioned tubules is 5.3 +/- 0.5 at birth, and progressively decreases until they disappear at 6 years of age. The numbers of types Ap and Ad spermatogonia per 10 cross sectioned tubules are similar to one another from birth (about 5.2) to 12-13 years of age (about 21.5), except during the period between 4 and 10 years of age, when the number of type Ad spermatogonia slightly decreases with respect to that of type Ap. This period coincides with the appearance of type B spermatogonia, of which the number per 10 cross sectioned tubules progressively increases from 4 (0.2 +/- 0.02) to 12-13 years of age (6.7 +/- 0.5). All spermatogonial types are found either resting on the basal lamina or lying toward the lumen. Some of the basal spermatogonia, but mainly those occupying a more adluminal position, appear hypertrophic, bi- or trinucleated, or degenerated. These anomalous spermatogonia are more abundant at 3 and 8 years of age, prior to periods of spermatogonial proliferation. At these times spermatocytes and occasional spermatids are seen in some seminiferous tubules of some children.

Adolescent↗
PubMed1984

Cystic dysplasia of the testis. Light and electron microscopic study of three cases.

The testes of two premature newborns and a 9-year-old boy with cystic dysplasia were studied by light and electron microscopy. The histologic pattern of the three cases was similar, differing principally in the extension of the characteristic lesion. This consisted of multiple, anastomosing, irregular cystic spaces of varying sizes and shapes, separated by incomplete connective-tissue septa. The cysts were predominantly located in the mediastinum testis, and spread irregularly, displacing the testicular parenchyma, which was consequently compressed under the tunica albuginea. Electron microscopic examination revealed two types of epithelial cells (flattened and tall cells) lining the cystic spaces. These cells were similar to those lining the normal adult rete testis. Since the rete testis originates from the gonadal blastema, and the efferent ductules from the mesonephric ducts, an embryologic defect in the connection between both structures might be responsible for this lesion.

Child↗
PubMed1984

Infertility in adult males with retractile testes.

The testicular biopsy, spermiogram, and hormonal assays performed on 23 infertile adult men with no other apparent cause of infertility than bilateral retractile testes are reported. Both luteinizing hormone and testosterone levels were normal, while follicle-stimulating hormone levels were normal or increased. The spermiogram showed oligozoospermia, asthenozoospermia, and severe teratospermia (tapering, amorphous, and immature forms). All the testicular specimens presented several focal histologic lesions, which were distributed in a mosaic pattern. The most frequent lesions were tubular lumen dilation, tubular diameter reduction, tunica propria thickening, tubular hyalinization, hypoplastic tubules, spermatocele, athrocytosis, vacuolation, or oncocytic transformation of Sertoli cell cytoplasm, maturation anomalies of spermatids, sloughing of immature spermatids, maturation arrests at the level of spermatids, primary spermatocytes or spermatogonia, germ cell hypoplasia, germ cell absence, peritubular and perivascular lymphocytic infiltrates, and venous angiectasis. These lesions seem to represent different progressive stages of tubular atrophy due to a temporary partial occlusion of the excretory ducts. This obstruction is probably caused by venous ectasia, which may be related to positional changes experienced by the testes during retraction.

Adult↗
PubMed1983

Testicular and epididymal involvement in Fabry's disease.

Autopsy specimens of the testes and epididymis of a 32-year-old male with Fabry's disease were studied by light and electron microscopy. The characteristic ceramide deposits (lamellar inclusions, myeloid-bodies, zebra-bodies) were found in the Leydig cells as well as in the epithelial lining of both the ductuli efferentes and the ductus of the epididymis. Similar myeloid-bodies were observed in the blood vessels, connective tissue cells and muscle cells of the testicular interstitium, tunica albuginea and epididymis. In contrast, myeloid-bodies were absent or scarce in both the seminiferous epithelium and the mediastinum testis. However, the seminiferous tubules were severely affected showing reduced diameter, thickening of the tunica propria, and a few degenerated spermatogonia and primary spermatocytes. The different degrees of involvement of the testicular structures might be related to their different functions, the absorptive and permeable structures being the most severely affected. The development of testicular alterations seems to have been slow, since the patient fathered three children.

Adult↗
PubMed1983

Histology and fertility after microsurgical anastomosis of the rabbit fallopian tube with nylon and polyglactin sutures.

Polyglactin and nylon suture material were compared in microsurgical anastomosis of oviduct of rabbits with regard to the histologic reaction, adhesion formation, and nidation index. Thirty days after surgery, the tissue inflammatory response was very similar in both groups. At 90 days, polyglactin had been totally absorbed in 80% of the cases, and no inflammatory reaction persisted at the site of the suture. At this time, multinucleated giant cell reaction to nylon sutures was persistent but minimal. The results reveal no significant functional differences between oviduct reanastomosed with nylon versus polyglactin suture. No significant difference in subsequent fertility due to suture selection was demonstrated.

Animals↗
PubMed1983

Transection of the spermatic vessels (Bevan's technique): an experimental study.

Intracanalicular or intra-abdominal undescended testicles often present a difficult surgical problem, due to a vascular pedicle shortening that prohibits scrotal placement with a 1 stage orchiopexy. The division of spermatic vessels to properly place the testis in the scrotum solves the problem of the shortening of the vessels, but raises the question of whether the endocrine function and the potential for fertility are preserved. In the present study transection of spermatic vessels before arterial branch-off was done intra-abdominally in rats. Angiographic, patho-anatomic and hormonal evaluations have been made. Revascularization of the testicular artery through the vasal artery has occurred in all cases. The anastomotic circuit, however, does not always have the same functional value. The spermatogenic alterations suggest that fertility can be impaired in a significant percentage of cases. Spermatogenesis was quantified taking into account the mean tubular diameter and the situation of seminiferous epithelium, expressed as the percentage of tubules containing well-developed spermatogenesis. Plasma testosterone levels are in a low range. However, Leydig cell functional response to human chorionic gonadotropin stimulation is maintained in every case and so are plasma and pituitary luteinizing hormone levels, suggesting that plasma testosterone levels are high enough to maintain an adequate hormonal activity.

Animals↗
PubMed1983

Elastic fibres of the human ductus deferens.

The distribution of elastic fibres in the human ductus deferens from birth to senility was studied by light and electron microscopy. Elastic fibres are lacking in the ductus deferens in infants and children. In the adult ductus deferens, they form two layers in the lamina propria: (1) an inner layer of circumferentially oriented elastic fibres, and (2) an outer meshwork of elastic fibres. Elastic fibres are also present in the narrow intercellular spaces between the smooth muscle cells of the muscular coat, mainly in the inner muscular layer. A layer of elastic fibres surrounds the muscular coat. The ductus deferens of ageing subjects shows fragmentation and disorganisation of the elastic fibre layers of the lamina propria. Elastic fibres in the muscular coat are more abundant than in younger adults, forming larger bundles. Electron microscopy demonstrated the presence of immature elastic fibres at puberty as collections of microfibrils, some of them containing loci of amorphous substance (elastin). In the adult ductus most elastic fibres have a mature appearance. The amount of amorphous substance has increased and the number of microfibrils has decreased. Electron-dense inclusions are present within the amorphous substance. With advancing age the amorphous substance forms large, structureless masses showing abundant electron-dense inclusions and areas of rarefaction. A thin layer of microfibrils is present only at the periphery of the elastic fibres. Whether or not androgenic hormones are in any way involved in the formation of elastic fibres in the ductus deferens and testis is something which requires further study.

Adolescent↗
PubMed1983

The postnatal development of the human sertoli cells.

Seminiferous tubules from infant testes show a mean tubular diameter of 70 micron with a high number of Sertoli cells (20...24 cells) per transverse tubular section which form a pseudostratified epithelium. Basal Sertoli cells have round to ovoid nuclei, regular in outline, with small nucleoli. The cytoplasm contains the usual organelles homogeneously distributed. Columnar Sertoli cells reach the lumen and show basal projections which surround the basal Sertoli cells. Basal regions of columnar cells contain numerous parallel microfilaments. Apical regions contain abundant rough endoplasmic reticulum, several Golgi complexes, and associated vesicles of electrondense content, Desmosome-like structures and extensive, flattened interdigitations are observed between Sertoli cells. Gap junctions between peritubular myofibroblasts and Sertoli cells are occasionally seen. During childhood the seminiferous tubules show a similar pattern, but the number of Sertoli cells per transverse tubular sections decreases (16...19 cells). From 9 years of age onwards the seminiferous tubules become thicker, the number of Sertoli cells decreases (12...15 cells), and the pseudostratified epithelium is gradually replaced by a columnar epithelium. The Sertoli cells begin to mature and smooth endoplasmic reticulum, mitochondria and lipid droplets develop. Annulate lamellae, crystals of Charcot-Böttcher, and Sertoli-Sertoli specialized junctions appear.

Adolescent↗
PubMed1982

Varicose axons bearing "synaptic" vesicles on the basal lamina of the human seminiferous tubules.

Normal (infant and adult) and pathological testes were examined by electron microscopy in order to study testicular innervation. Nerves composed of non-myelinated fibres were abundant in the tunica vasculosa of the tunica albuginea. These nerves penetrated into the testicular septa reaching the interstitial tissue. This showed numerous non-myelinated nerve fibres running among the Leydig cells and blood vessels. Single axons or small groups of them, partially surrounded by Schwann cells, approached: 1) the Leydig cells, 2) the interstitial blood vessels, and 3) the seminiferous tubules. Single naked axons were also observed primarily in the proximity of the seminiferous tubules. These axons showed varicosities containing both small and large "synaptic" vesicles. The latter were less numerous and contained a central dense core. Small vesicles were agranular. Some varicose axons ran across the myofibroblast layer of the tunica propria reaching the basal lamina of the seminiferous tubules at the level of the Sertoli cells but not at the level of the spermatogonia. The intercellular space between Sertoli cell and axon membrane was about 150-200 nm.

Adolescent↗