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Biomedical subjects

R Paniagua

Publications and source records attributed to R Paniagua.

At least 199 records · Page 11Linked to original sources
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

Structural changes in the rat myocardium after exhaustive exercise.

The ventricular myocardium of rats sacrificed immediately after exhaustive swimming exercise showed the following degenerative changes. The organization of the myofilaments varied from an accentuated hypercontraction of the sarcomeres to a disorganization of the same with loss of orientation of the myofilaments and blurring of the Z lines ("contraction bands"). The mitochondria showed an increased swelling along with disorganization of the cristae and narrow joints between the membranes. The nuclei showed an increase in the amount of heterochromatin. All these changes were evident in the first few minutes of the exercise and they reached their maximum level between the first and second hours, diminishing during the second and third hour. The effect produced in the myocardium by this exercise is reversible, since the appearance of the fibres in rats sacrificed at the twelfth, twenty-fourth, and forty-eight hour following the end of the exercise was approaching that of the controls.

Animals↗
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

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↗
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

Zinc, prolactin, gonadotropins, and androgen levels in uremic men.

This study correlates plasma levels of Zinc (Zn) and some pituitary and testicular hormones in 20 uremic men (aged 17-58 years) on a weekly peritoneal dialysis program. Patients were compared to 12 healthy male volunteers (aged 28-40 years). In uremic men, plasma androstenedione (A) was elevated, while testosterone (T), dihydrotestosterone (DHT), and Zn were low. On a group basis, plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) were normal while prolactin was increased. A negative correlation was observed between plasma A and LH levels, as well as between the A/T+DHT ratio and plasma Zn concentrations. Our results suggest a diminished A-to-T conversion and point to the possible role of Zn in the enzyme activity of the 17 beta-hydroxysteroid dehydrogenase.

Adolescent↗
PubMed1982

Endocrine profile in patients with chronic renal failure under zinc replacement.

The plasma levels of androstenedione (A), testosterone (T), dihydrotestosterone (DHT), follicle stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) were studied in 15 men (aged 24-50 years) with chronic renal failure under periodic peritoneal dialysis, before and after 50 mg of elemental zinc (Zn) orally, twice a day for three weeks. Before treatment, they were divided into three groups: group I, plasma A above normal and PRL less than 100 ng/ml; group II, low or normal A levels with PRL less than 100 ng/ml; and group III, normal or high A levels with PRL greater than 100 ng/ml. After oral Zn, plasma FSH, LH, and PRL were unchanged in all groups; however, in groups I and II plasma A was within normal T and DHT rose significantly, the A/(T+DHT) ratio decreased to normal, and the T/DHT ratio rose above normal. In group III plasma androgens remained low and androgen ratios were unchanged. Oral Zn seems to improve the conversion of A to T and also uncovered the possibility that plasma PRL levels greater than 100 ng/ml might cause a blockade in the 5 alfa-reductase.

Adult↗
PubMed1982

Testicular function in men with chronic renal failure and transplant recipients under bromoergocriptine therapy.

Plasma zinc (Zn), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and androgens concentrations were determined in 15 male patients with chronic renal failure who were successful recipients of kidney transplant. After 25 +/- 8.5 months of the renal transplant, Zn levels were (88 +/- 4 g/dl) lower than in the control group (116 +/- 5 micrograms/dl). Normal concentrations for androstenedione (A) (0.63 +/- 0.05 ng/ml) and testosterone (T) (3.31 +/- 0.15 ng/ml) were found. Dihydrotestosterone (DHT) levels (0.38 +/- 0.01 ng/ml) were lower than normal (1.11 +/- 0.09 ng/ml), suggesting a blockade in the conversion of T to DHT. Eleven of the 15 patients showed higher PRL levels (9.5 +/- 0.8 ng/ml) in contrast with the normal group (3.6 +/- 0.3 ng/ml). Ten patients received orally 2-alpha-bromoergocriptine (BEC) 2.5 mg/day for ten days. Plasma PRL decreased to 2.6 +/- 1.0 ng/ml (p less than 0.001), but A and T levels did not significantly change; however, DHT increased from 0.38 +/- 0.02 ng/ml to 0.72 +/- 0.04 ng/ml (p less than 0.01). All patients showed an increase in both gonadotropins before BEC without significant changes after treatment. The high PRL levels may be responsible for the impaired conversion of T to DHT, possibly by interference with the enzyme 5 alpha-reductase.

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↗