Biomedical subjects

R Paniagua

Publications and source records attributed to R Paniagua.

At least 127 records · Page 7Linked to original sources

PubMed1990

Quantitative and ultrastructural alterations in the lamina propria and Sertoli cells in human cryptorchid testes.

A quantitative and ultrastructural study was performed on biopsies of human cryptorchid testes to investigate lesions in the lamina propria and Sertoli cells. Prepubertal cryptorchid testes (1-9 years of age) were classified into four groups: Type 1, testes with minimal lesions; Type II, testes with a moderate decrease in tubule diameter and spermatogonal number; Type III, testes with Sertoli cell hypoplasia and a marked reduction in tubule diameter and spermatogonal number; and Type IV, testes with Sertoli cell hyperplasia and a variable reduction in spermatogonal number. An increase in thickness of the lamina propria was found in Type II and III testes from 5 years of age onwards. These testes also showed a decrease in both the average number of peritubular cells per cross-sectioned tubule and in the average nuclear volume of these cells. Most of the postpubertal cryptorchid testes from 13- to 18-year-old youths presented a prepubertal pattern suggestive of delayed testicular maturation. Postpubertal testes from 19- to 27-year-old men were classified into three types: Type A testes showed complete spermatogenesis, mature Sertoli cells and no lesions in the lamina propria; Type B testes showed isolated spermatogonia, mature Sertoli cells, and a marked thickening of the lamina propria; and Type C testes showed isolated spermatogonia, hyperplasia of immature Sertoli cells, and a slightly thickened lamina propria. Maturation of the lamina propria was always associated with maturation of the Sertoli cells. Thickening of the lamina propria was associated with peritubular cell alterations consisting of decreases in the nuclear volume (average and total per testis) of peritubular cells and increases in the number of these cells per cross-sectioned tubule. The three types of adult cryptorchid testes appear to be the postpubertal transformation of Type 1 testes (Type A), Type II and Type III testes (Type B), and Type IV testes (Type C).

Adult↗

PubMed1990

Histochemistry and ultrastructure of nerve fibres and contractile cells in the tunica albuginea of the rat testis.

Whole-mounted preparations of the tunica albuginea of the rat testis were studied using light microscopy techniques for demonstration of cholinergic nerve fibres (Karnovski-Root method), catecholaminergic nerve fibres (De la Torre's method) and actin filaments (avidin-biotin-peroxidase method). An ultrastructural study of different regions of the albuginea was also performed. Cholinergic fibres were seen to penetrate into the albuginea with the testicular artery to form a broad network in the mediastinum testis, many fibres ending beneath the rete testis epithelium. Catecholaminergic fibres penetrated through the middle part of the cauda epididymis and formed a plexus in the albuginea covering the inferior testicular pole. This plexus gave rise to straight fibres which formed varicosities, some of them appeared related with mast cells. Actin-containing cells were only found beneath the rete testis epithelium. These cells were similar to myofibroblasts. The location of both cholinergic fibres and contractile cells among the rete testis channels suggests that these cells may be involved in the pumping of semen towards the ductuli efferentes and that their contractility may be regulated by cholinergic fibres.

Acetylcholine↗

PubMed1990

Carcinosarcoma of the spermatic cord.

The first case of carcinosarcoma in the spermatic cord is reported in a 40-year-old man. The tumor was a 2.5 X 2 cm pseudoencapsulated formation located in the connective tissue of the spermatic cord among the blood vessels. Light microscopy examination of the neoplasm revealed two different histological patterns: epithelial and sarcomatous. Mitoses and atypias were infrequent in both types of areas. The epithelial cells formed papillary and gland-like structures stained with PAS, Hale and mucicarmine stains, and showed positive reaction for immunohistochemical demonstration of both keratin and epithelial membrane antigen. The lumen content of the gland-like structures reacted positively for the carcinoembryonic antigen. Electron microscopy revealed that the epithelial cells were joined by junctional complexes and displayed numerous short microvilli. The sarcomatous areas consisted of spindle cells embedded in a ground substance that occasionally presented myxoid changes. Mast cells and focal calcifications were seen. Sarcomatous cells showed positive reaction for vimentin but not for the other histochemical and immunohistochemical techniques mentioned above. The ultrastructure of sarcomatous cells was similar to that of epithelial cells except for the occurrence of small desmosomes instead of junctional complexes. The differential diagnosis with adenomatoid tumor and malignant mixed mesothelioma is discussed.

Adult↗

PubMed1990

Idiopathic hematoma of the epididymis: presentation of three cases.

Three cases of idiopathic hematoma are reported for the first time. The disease presented with clinical symptoms of epididymitis and was unsuccessfully treated with antibiotics. The persistence of the symptoms and the suspicion of tumor led to the removal of the lesioned epididymides. The etiology of these hematomas and their differential diagnosis in relation with other benign processes of the epididymis are discussed.

Adult↗

PubMed1990

Pitted pattern in the human epididymis.

This histological study of the human ductus epididymidis in autopsy or surgical specimens revealed the presence of multiple intra-epithelial cavities or pits showing a variable degree of development. In their origin, cavities were surrounded by cells with the same staining affinity and ultrastructural features as the principal cells, except for the cavity basal surfaces that were supported by lower cells. The latter cells, although otherwise like the basal cells of the ductus epididymis, displayed short microvilli in the cavity lumen. When the cavities expanded the basal cells became principal cells, while the principal cells located at the top of the cavities degenerated, creating pits that opened into the lumen of the ductus epididymidis. The surface occupied by the pitted areas increased progressively between the end portion of the caput epididymidis and the corpus-cauda transition, where it decreased abruptly. This pitted pattern was observed in all the normal adult men studied and in the children with precocious puberty but not in the normal children or in the adult men with hypogonadotrophic hypogonadism. This observation suggests that the development of pitted cavities is androgen-dependent.

Adult↗

PubMed1990

Polyorchidism in a newborn: case report and review of the literature.

A case of polyorchidism in a newborn is reported. The left scrotum contained two testes sharing the same epididymis and vas deferens. The histometric testicular parameters were normal in the three testes, except for a slightly reduced tubular fertility index in the supernumerary testis.

Epididymis↗

PubMed1990

Effects of photoperiod and temperature on testicular function in amphibians.

Most amphibians present an annual testicular cycle characterized by a quiescent period (late autumn-winter) and a spermatogenic period (spring and summer). At the end of the period of spermatogenesis undifferentiated interstitial cells transform into steroid-secreting Leydig cells which regress in spring at the beginning of the new spermatogenetic cycle. The testicular cycle is controlled by the pituitary gonadotropin levels which are high in autumn and winter, low in spring and increase temporarily in the middle of summer. Photoperiod and temperature seem to be the most important external factors involved in the regulation of this cycle in many amphibian species since the colder the geographic area, the longer the quiescent period and the shorter the spermatogenic period. This suggests the occurrence of a potentially continuous cycle in these species, in contrast with that which occurs in other species having an endogenous rhythm of testicular function which is much less sensitive to environmental factors. Although the specific response to temperature can vary widely between species, the most frequent observation in amphibians with a potentially continuous cycle is that exposure to mild temperatures (15-20 degrees C, according to the spring temperatures of the different geographic areas) stimulates spermatogenesis even during the period of testicular quiescence. If this mild temperature is combined with a long photoperiod, complete spermatogenesis is attained. Experiments performed during the period of germ-cell proliferation (development from spermatogonia to round spermatids) indicated that low temperatures (below 11 degrees C) as well as short photoperiods (less than 8 h of light) hinder germ-cell proliferation. Moderately high temperatures (about 30 degrees C) do not impair this proliferation. In the newt Triturus marmoratus, it has been shown that an excessively long photoperiod (over 16 h) has the same effect as a short photoperiod. In this species eyes are not required for the testicular photoperiodic response. Photoperiod appears to have no effect on spermiogenesis (differentiation of round spermatids into spermatozoa), because once round spermatids are formed, spermiogenesis will occur even in total darkness. Mild temperatures seem to be necessary for spermiogenesis as well as for androgen biosynthesis because neither process will take place at extreme temperatures. Results on the effect of photoperiod in steroidogenesis differ between species.

Amphibians↗

PubMed1990

Involution of human fetal Leydig cells. An immunohistochemical, ultrastructural and quantitative study.

The testes of stillborn fetuses (from 13 to 28 weeks of gestational age), fetuses born alive (from 29 weeks of gestational age) who died a few days later, and infants dying 1 to 8 months after birth were processed for light and electron microscopy. Paraffin-embedded material was stained with the avidin-biotin peroxidase complex (ABC) method for immunohistochemical detection of testosterone (T) in order to quantify the age-related changes in the number of T-positive interstitial cells. This number decreased progressively from the 24th week of gestation up to birth and remained unchanged up to the second month of postnatal life. During the third month of age, the number of T-positive cells rose markedly but fell again from the fourth month to the end of the study. The ultrastructural study revealed the following types of interstitial cells at all ages studied: fibroblast-like cells, myofibroblast-like cells, developed fetal Leydig cells, degenerating fetal Leydig cells and infantile Leydig cells with a multilobed nucleus and focal cytoplasmic accumulations of smooth endoplasmic reticulum and lipid droplets. Quantitative ultrastructural studies revealed that the changes in the number of fetal Leydig cells with age were similar to those found in the number of T-positive cells although, for each age studied, absolute values were higher in the ultrastructural study. The number of infantile Leydig cells increased with age.

Aging↗

PubMed1989

Carcinoma in situ of the testis in infertile men. A histological, immunocytochemical, and cytophotometric study of DNA content.

Of 723 infertile men (128 with a history of cryptorchidism) whose testes were biopsied at the outer lateral face of the testis, five presented carcinoma in situ (CIS) in one testis. These testes were removed, serially sectioned, and examined by light microscopy. In order to evaluate whether only one or two biopsies are sufficient to diagnose CIS, before sectioning the testes four biopsies were taken at the anterior face, posterior face, superior pole, and inferior pole of the testis, respectively. Two of the five men had undergone orchiopexy in infancy and the testis contained tubules with Sertoli cells and isolated spermatogonia. CIS was also present in some tubules that were principally located near the rete testis. Of the four simulated biopsies, only that performed at the posterior face of the testis revealed CIS. The other three infertile men showed tubules with complete, although reduced, spermatogenesis, and tubules lined by Sertoli cells only. CIS was found in both types of tubules. These tubules with CIS formed lobules that extended throughout the testicular parenchyma. Most simulated biopsies performed in these three testes showed CIS. The average nuclear DNA content of CIS cells was about 4c in all testes. This content was similar both in tubules with complete spermatogenesis and in tubules with Sertoli cells only.

Adult↗

PubMed1989

Nodular proliferation of calcifying connective tissue in the rete testis: a study of three cases.

We report the first description of a bilateral rete testis lesion. The lesion was found in three adult men with histories of myocardium infarct or hemorrhage. The histologic study of the rete testis in these men revealed nodular sessile or pediculate formations which protruded into the rete testis channels. These polypoid formations consisted of an axis of connective tissue covered by a flattened epithelium. The axis contained a variable number of fibroblasts, areas with fibrin-like material, and small to large calcium deposits. Inflammatory infiltrates were neither observed in the rete testis nor in the testicular parenchyma. The testicular pattern varied from seminiferous tubules with complete spermatogenesis (two cases) to tubules with Sertoli cells and a few spermatogonia, surrounded by a thickened tunica propia. The term "nodular proliferation of calcifying connective tissue in the rete testis" is proposed to designate this lesion.

Aged↗

PubMed1989

Acquired cystic transformation of the rete testis secondary to renal failure.

The histologic study of testicular specimens from 218 consecutive autopsies revealed a cystic transformation of the rete testis in 26 men. Serial sections of the testes, epididymides, and spermatic cords of these men were studied by light microscopy. In 15 cases, the rete testis dilation was caused by obstruction of the epididymis. In five cases, the dilation was due to obstruction of the intratesticular excretory ducts caused by varicocele. In the remaining six men, no evidence of obstructive processes was found. These six patients had been diagnosed with renal failure and underwent hemodialysis. The rete testis in these men showed dilated channels lined by a high columnar or pseudostratified epithelium. They contained spermatozoa, with a proteinaceous material and calcium oxalate crystals. The ductuli efferents showed eosinophilic granules in their epithelial cells and their lumen contained spermatids, spermatozoa, cell remnants, calcium oxalate crystals, and multinucleate giant cells. These rete testis lesions are similar to those previously reported in the kidney of hemodialyzed patients.

Calcium Oxalate↗

PubMed1989

Paratesticular metastases from congenital retroperitoneal tumor.

A retroperitoneal tumor was removed from a fifteen-day-old infant. Light microscopy revealed a teratoma consisting mainly of immature nervous tissue. Three months later the patient had recurrence and numerous peritoneal metastases showing a histologic pattern similar to that of the primary tumor. Twelve months later there was enlargement of the left testis due to metastases from teratoma infiltrating the tunica vaginalis of the left testis, the epididymis, and the spermatic cord. These metastases consisted of mature neurons and glial cells. The early dissemination of the tumor suggests an intracavitary spread pattern. The tumor maturation in paratesticular structures suggests that mesothelial cells are involved in the differentiation of tumoral germ cells.

Combined Modality Therapy↗

PubMed1989

Comparison of dot enzyme-linked immunosorbent assay (Dot-ELISA), passive haemagglutination test (PHT) and thin layer immunoassay (TIA) in the diagnosis of natural or experimental Fasciola hepatica infections in sheep.

The dot enzyme-linked immunosorbent assay (Dot-ELISA) was compared with the passive haemagglutination test (PHT) and thin layer immunoassay (TIA) for the detection of antibodies against Fasciola hepatica in naturally and experimentally infected sheep. The infected animals gave titres from 1:25,000 to 1:204,000, while control animals gave titres of from 1:100 to 1:800. The titres of the infected sheep obtained by Dot-ELISA were 1000-2000 times higher than the ones obtained using TIA or PHT. Due to its high sensitivity, this technique could be very useful for the diagnosis of ovine fascioliasis.

Animals↗

PubMed1989

Testicular carcinoma in situ associated with rhabdomyosarcoma of the spermatic cord.

A 12-year-old boy had an embryonal rhabdomyosarcoma in the distal portion of the spermatic cord. The tumor partially surrounded the testis, infiltrated the testicular tunics and formed an intratesticular nodule near the rete testis. The unaffected testicular parenchyma exhibited the characteristic germ cells of carcinoma in situ. We describe an association between these 2 types of tumors.

Carcinoma in Situ↗

PubMed1989

Secondary testicular tumors.

A review of 3,474 consecutive autopsies on adult men showed that 337 men had died of cancer, and 2 of them presented with testicular metastases from a pancreatic carcinoma and a urinary bladder carcinoma, respectively. In addition, of 32 men with prostatic carcinoma whose testes were removed, 1 man presented with testicular metastases from the tumor, and of 216 patients (children and adults) with neuroblastoma, 2 children showed metastases to the testes.

Adrenal Gland Neoplasms↗

PubMed1989

Proliferative activity of human spermatogonia from fetal period to senility measured by cytophotometric DNA quantification.

The proliferative activity of human spermatogonia from the fetal period to senility was studied by means of cytophotometric quantification of the nuclear DNA content in histological sections. Proliferating spermatogonia that were replicating or had replicated their DNA (DNA content between 2.5c and 4.5c) were observed in all ages. The percentages of these spermatogonia were high (18.2%) in the second trimester of gestation, decreased in the third trimester (8.2%), maintained similar values in newborns (7.1%) and infants (9.5%), and increased markedly in 4- to 9-year-old children (22.5%). The latter percentage was maintained during puberty (20.1%), decreased significantly in adulthood (17.8%), and was higher in aging testes (25.2%). About 2% of spermatogonia with a DNA content higher than 4.5 c were observed from 4-15 years of age as well as in the testes of elderly men. Sertoli cells replicating their DNA were observed only in fetuses.

Adolescent↗

PubMed1989

Annual changes in the number, testosterone content and ultrastructure of glandular tissue cells of the testis in the marbled newt Triturus marmoratus.

The testes of 8 specimens of Triturus marmoratus were collected during each month of 1987 and processed for electron microscopy and light microscopy demonstration of testosterone (T) following the ABC (avidin-biotin peroxidase complex) method. According to their staining affinity for anti-T antibodies, the glandular tissue cells were classified as T-, T+, T++, and T and the annual changes in the numbers of these cell populations, as well as in the volume occupied by the glandular tissue, were calculated. The volume occupied by the glandular tissue increases from September to December; it begins to decrease in April and disappears from June to August. The glandular tissue is formed from the interstitial cells that surround the lobules containing differentiating germ cells. During the spermatogenic process, the interstitial cells do not show staining affinity for anti-T antibodies. In August-September, the interstitial cells around the lobules that have completed spermatogenesis become positively stained (T+) and form the glandular tissue when the spermatozoa leave the testis. The numbers of intensely stained cells in the glandular tissue (T++ and T ) increase from September to November; begin to decrease in December; disappear in January-February; increase again in March and decrease again in April until they disappear in June-September. The interstitial cells, before their transformation in glandular tissue, are ultrastructurally similar to fibroblasts. After their transformation these cells increase in size and develop abundant smooth endoplasmic reticulum, mitochondria with tubular cristae and lipid droplets. This morphological pattern is maintained in the glandular tissue from September to April in spite of the changes in staining affinity during this period.

Animals↗

PubMed1989

Cysts of the testicular parenchyma and tunica albuginea.

Five cases of cysts of the tunica albuginea and two cases of cysts of the testicular parenchyma are described. The cysts of the albuginea were located in the anterior, lateral, and inferior faces of the testis (distant from the epididymis) and covered by a thin albuginea. They extended toward the testicular parenchyma or toward the tunica vaginalis. Their epithelial lining varied from low cuboidal to columnar and consisted of ciliated or nonciliated cells. These cysts were probably of mesothelial origin. The cysts of the testicular parenchyma were also located distant from the mediastinum testis and were not in contact with the albuginea. Their epithelial lining consisted of flattened, cuboidal, nonciliated cells. The origin of the cysts of the testicular parenchyma is not clear. In one case the occurrence of spermatozoa in the cyst lumen and connections with seminiferous tubules suggests an origin in the rete testis.

Aged↗