Biomedical subjects

R Paniagua

Publications and source records attributed to R Paniagua.

At least 145 records · Page 8Linked to original sources

PubMed1989

Secondary amyloidosis of the testis: an electron microscopic and histochemical study.

A histochemical and ultrastructural study of the testes, epididymides and spermatic cords from 6 adult men with amyloidosis secondary to several diseases is described. Amyloid fibrils, consisting mainly of AA protein, were deposited in the walls of blood vessels of the testis, epididymis and spermatic cord, as well as in the tunica propria of the seminiferous tubules. The seminiferous epithelium showed slight hypospermatogenesis. Many Leydig cells exhibited unstained 'bar' or 'arc'-shaped cytoplasmic areas similar to the cholesterol deposits of Leydig cells in adrenoleukodystrophy.

Adult↗

PubMed1988

Adenomatous hyperplasia of the rete testis.

A gland-like cellular proliferation was observed in the deepest portion of the rete testis in both testes from a 55-year-old man who died from metastasis of breast carcinoma to the brain. The gland-like proliferations consisted of columnar epithelial cells supported by a thin lamina propria. These cells displayed irregularly outlined nuclei with deep indentations. Atypias and mitoses were infrequent. The term 'adenomatous hyperplasia of the rete testis' is proposed to designate the benign lesion reported here.

Adenocarcinoma↗

PubMed1988

Changes in surface area and number of Leydig cells in relation to the 6 stages of the cycle of the human seminiferous epithelium.

In order to evaluate the occurrence of a Leydig cell cycle related to the cycle of the seminiferous epithelium in man, the numbers of peritubular Leydig cells and surface area of these cells along 1 mm of tubular basement membrane at each stage of the cycle were calculated on histological sections of young adult testes. The Leydig cells that were located separated from the tubules (perivascular Leydig cells) were also classified according to the stage of the cycle shown by the nearest seminiferous tubule; the surface area and number of these cells were also calculated. The total surface area and numbers of Leydig cells (peritubular plus perivascular) along 1 mm of tubular basement membrane did not change during the cycle of the seminiferous epithelium. Both the surface area and the numbers of peritubular Leydig cells were greater in stages I and II of the cycle, when spermatozoa are released; they decreased in stages III and IV and increased again in stages V and VI, whereas the contrary occurred in perivascular Leydig cells. The average surface area of each Leydig cell type remained constant throughout the stages of the cycle.

Adult↗

PubMed1988

Effects of immobilization on fetal bone development. A morphometric study in newborns with congenital neuromuscular diseases with intrauterine onset.

The effects of immobilization on fetal bone development were studied through post-mortem radiographs in 11 newborns with congenital neuromuscular diseases (CNMD) of intrauterine onset. Quantitative parameters were determined in the following bones: tibia, femur, humerus, radius, 3rd lumbar vertebra, and 5th rib. Thirty stillborns or newborns of similar gestational age and deceased from causes other than neuromuscular or related diseases were used as controls. No significant differences in bone lengths were observed between both groups. However, external diameters, cortex thicknesses, and cortical areas values were significantly lower in newborns with CNMD than in the control group. In newborns with CNMD, the medullary diameter of long bones showed good correlation with gestational age. However, this diameter was greater than that expected according to the reduced external diameter. These results suggest that intrauterine immobilization induces a decrease in mechanical usage of bone, mainly influencing bone modeling and probably bone remodeling. No changes were observed in longitudinal bone growth. Bones showed osteopenia and mechanical defects and were prone to fractures. In summary, reduced immobilization in utero produces bone osteoporosis of the fetus.

Bone Development↗

PubMed1988

Long day photoperiods and temperature of 20 degrees C induce spermatogenesis in blinded and non-blinded marbled newts during the period of testicular quiescence.

Adult male marbled newts (Triturus marmoratus) were collected at the end of the spermatogenesis period and exposed to different photoperiods (natural-daylength-simulated photoperiod, total darkness, 8L:16D, 12L:12D, 16L:8D, and continuous light) for 3 mo. Temperature was maintained at 20 degrees C. Two additional groups of newts were blinded and exposed to either the natural-simulated photoperiod and to 16 h of light per day respectively. Quantitative histologic studies on testicular development and germ cell volume per testis were performed. The newts captured in the field at the beginning (initial controls) or at the end of the experiments (final controls) were in the period of testicular quiescence. Newts kept in total darkness or exposed to a short photoperiod (8L:16D) showed germ cell development up to primary spermatocytes, whereas germ cell development in the newts exposed to long photoperiods (12L:12D or 16L:8D) progressed to elongated spermatids. The newts exposed either to intermediate photoperiods (natural-simulated photoperiod) or to constant light showed an intermediate degree of germ cell development (up to round spermatids). No significant differences between non-blinded and blinded animals were found. These results suggest that (1) mild temperature initiates testicular development in the period of testicular quiescence, (2) long photoperiods associated with mild temperatures produce spermatogenesis in this period, (3) complete darkness or constant light are less effective than some intermediate photoperiod, and (4) the effect of photoperiod on testicular function in newts is not related to ocular photoreception.

Animals↗

PubMed1988

Congenital Leydig cell hyperplasia.

The testes and epididymes collected at autopsy from 21 newborns showed apparent Leydig cell hyperplasia which was studied by light and electron microscopy. Twelve newborns were the sons of diabetic mothers, two had undergone rhesus isoimmunization, two were twins of a non-diabetic mother, three had Beckwitz-Widemann's syndrome, and two had leprechaunism. In the first two groups the placentas were also collected and studied. All the testes showed normal seminiferous tubules and diffuse Leydig cell hyperplasia in the testicular interstitium. In addition one son of a diabetic mother and another with Beckwitz-Widemann's syndrome presented multiple Leydig cell nodules in the mediastinum testis and epididymis. The number of Leydig cells per unit area of the testis was calculated on histological sections stained with the peroxidase-anti-peroxidase method for the detection of testosterone. These numbers varied from 1.4 to 3.2 times those found in age-matched controls, except for the two testes with nodular hyperplasia in which the increase in Leydig cells was even greater. The differential diagnosis between Leydig cell hyperplasia, ectopic adrenal cells and leydig cell tumour is discussed. It is proposed that the cause of congenital Leydig cell hyperplasia might be related to placental secretion of human chorionic gonadotrophin.

Autopsy↗

PubMed1988

Inflammatory malignant fibrous histiocytoma of the spermatic cord.

A 74-year-old man with a right inguinal hernia since 15 years was admitted because of inguinal pain and enlarged ipsilateral testis. Surgical exploration revealed a hernia with an empty hernial sac and three tumoral masses in the spermatic cord. Tumoral masses, spermatic cord, and testis were removed. Histological examination of the tumoral masses revealed a malignant inflammatory fibrous histiocytoma. The tumor infiltrated the vas deferens, pampiniform plexus, and adjacent adipose tissue. Epididymis and testis were not infiltrated. Three years after treatment with radiotherapy no recurrence or metastases have been observed.

Aged↗

PubMed1988

Juvenile granulosa cell tumor of the testis.

Juvenile granulosa cell tumor occurred in a newborn. The tumor presented with testicular torsion, and no malformations were observed. The karyotype was normal. The occurrence of initial tumoral lesions in the seminiferous tubules located in the vicinity of the tumor suggests that the tumor originated from immature Sertoli's cells. To our knowledge, this is the tenth case reported in a newborn and the second associated with testicular torsion.

Granulosa Cell Tumor↗

PubMed1988

Changes in the long bones due to fetal immobility caused by neuromuscular disease. A radiographic and histological study.

The long bones in eleven newborn infants who had neuromuscular disease were studied and were found to be thin, hypomineralized, and elongated. In most of the bones, there were multiple diaphyseal or metaphyseal fractures, or both. By light microscopy, the outstanding findings were fractures through the growth plate and diaphysis and thinning of the cortices. The etiology of the fractures and the insufficient substance of the bone is the reduction in the intrauterine motion of the fetus, which leads to fragility of the bones and contractures of the joints. The severity of the alterations may have been related to the time of the onset of the abnormalities and to the duration and degree of the intrauterine akinesia.

Abnormalities, Multiple↗

PubMed1987

Quantification of cell types throughout the cycle of the human seminiferous epithelium and their DNA content. A new approach to the spermatogonial stem cell in man.

The numbers of each different cell type in the human seminiferous epithelium were determined throughout the 6 stages of the cycle in both semithin and ultrathin sections obtained from 15 young adult men with normal testicular histology. Up to 4 types of A spermatogonia (Ad, Ap, Al and Ac) were distinguished. In addition, the DNA nuclear content of seminiferous epithelium cells was determined on Feulgen-stained sections. Both Ad and Ap spermatogonia showed a 2c DNA content and were present in the 6 stages of the cycle, though their numbers decreased in stages III-V. Both Al and Ac spermatogonia showed a DNA content varying from 2c to 4c. Al spermatogonia were observed in stages III-V; their numbers plus those of Ad spermatogonia in these stages were similar to the numbers of Ad spermatogonia in the other stages lacking in Al spermatogonia. Ac spermatogonia appeared in stages III-VI and their numbers plus those of Ap spermatogonia in stages III-V were similar to the numbers of Ap spermatogonia in the other stages lacking in Ac spermatogonia. The results suggest that Ad spermatogonia are the stem cells. Some of them replicate their DNA; during this replication they appeared as Al spermatogonia. Al spermatogonia divide, giving rise to both Ad and Ap spermatogonia. Some Ap spermatogonia replicate their DNA; during this process they are transformed into Ac spermatogonia which divide, giving rise to B spermatogonia.

Adult↗

PubMed1987

Osteochondroma induced by reflection of the perichondrial ring in young rat radii.

In order to investigate the effects of reflection of the perichondrial ring in osteochondroma formation, the perichondrial rings of the epiphyseal growth plates in 42 young rat radii were turned to the metaphyseal periosteum by means of blunt dissection. Seven days after surgery a small nest of chondrocytes appeared on the metaphyseal-diaphyseal bone surface at the level of the tip of the reflected perichondrial ring. From the 9th to the 15th days the histological pattern of the osteochondroma was established. The osteochondroma was not connected with the hypertrophic cartilage of the growth plate. During the third and fourth weeks the osteochondroma began to regress with the disappearance of the cartilage nest. During the development of the lesion the bone grew normally and the growth plate migrated distally while the lesion remained at its initial site. The growth plate zone devoid of perichondrial ring was covered by fibrous connective tissue and no removal of the perichondrial ring occurred. These results suggest that the origin of this osteochondroma is the perichondrial ring cells whose polarity has been surgically changed.

Animals↗

PubMed1987

Hyperplasia of spermatic cord nerves: a sign of testicular absence.

The comparative histologic study of the spermatic cord in the absence of testis, epididymis-testis separation, and normal development of both testis and epididymis, revealed that there is nerve trunk hyperplasia and hypertrophy in absence of the testis. This finding may greatly aid the diagnosis of testicular absence in the management of impalpable testes.

Cryptorchidism↗

PubMed1987

Testicular involution in elderly men: comparison of histologic quantitative studies with hormone patterns.

An endocrinologic and quantitative histologic study was carried out in 64 elderly men who underwent orchidectomy owing to prostatic carcinoma. The men were classified into age groups (decade of life), and each group was subdivided into group A (testes with complete spermatogenesis in most tubules) and group B (testes showing maturation arrest of spermatogenesis in most tubules). Up to 80 years of age, men of group A showed hormone levels and testicular parameters similar to those of young control men. From 50 to 60 years of age, men of group B showed a significant decrease in testicular volume, tubular volume, tubular length, number of germ cells, Sertoli cells and Leydig cells per testis, and plasma testosterone levels, whereas the tunica propria thickness and plasma levels of both follicle-stimulating hormone and luteinizing hormone were increased.

Adult↗

PubMed1987

Correlation between spermatozoon numbers in spermiogram and seminiferous epithelium histology in testicular biopsies from subfertile men.

A new method for correlating testicular biopsies and spermiograms is proposed. The number of spermatogonia, round spermatids, and elongated spermatids per cross-sectioned tubule were calculated in the testes from 33 subfertile men and in 10 control normal testes. According to these quantitations, the testes in subfertile men were classified as testes with maturation arrest of spermatogenesis, testes with hypospermatogenesis, and testes with associated maturation arrest and hypospermatogenesis. A power regression curve correlating the number of elongated spermatids and sperm numbers in the spermiogram was performed.

Adult↗

PubMed1987

Seminiferous tubule involution in elderly men.

The observation of different types of seminiferous tubules (from tubules with normal spermatogenesis to sclerosed tubules) in aging human testes points to the progressive stages of tubular involution in elderly men. The tubules with hypospermatogonesis (reduced number of elongated spermatids) show numerous morphological anomalies in the germ cells, including multinucleated cells. Abnormal germ cells degenerate, causing Steroli cell vacuolation. These vacuoles correspond to dilations of the extracellular spaces resulting from the premature exfoliation of germ cells. Degenerating cells that are phagocytized by Sertoli cells lead to an accumulation of lipid droplets in the Sertoli cell cytoplasm. The loss of germ cells begins with spermatids, but progressively affects the preceding germ cell types, and tubules with maturation arrested at the level of spermatocytes or spermatogonia are observed. Simultaneously, an enlargement of the tunica propria occurs. This leads to the formation of sclerosed tubules, some of which display a low seminiferous epithelium consisting of a few cells--including lipid-loaded Sertoli cells and both Ap and Ad spermatogonia--and others, showing complete sclerosis, are devoid of seminiferous epithelium. The development of tubular involution is similar to that reported after experimental ischemia, which also seems to cause nonspecific effects on the testis such as multinucleate cells, vacuoles, and increased lipids in Sertoli cells.

Adult↗

PubMed1987

Tubular embryonal remnants in the human spermatic cord.

The spermatic cords (SCs) obtained from: (a) autopsies of 67 adults and 50 children; (b) 3 fetuses; (c) 12 surgical specimens from 9 adults and 3 children with testicular tumors, and (d) 26 surgical specimens (14 adults and 12 children) with diagnosis of SC cysts, were studied by light microscopy. The histological study revealed the occurrence of tubular embryonal remnants (TERs) in 19 autopsied adults, 14 autopsied children, 3 fetuses, 2 surgical specimens (1 adult and 1 child) owing to testicular tumors, and 6 surgical specimens with diagnosis of SC cysts. The TERs were found in the low, middle or high thirds of the SC and consisted of a cuboidal or columnar, often ciliated epithelium surrounded by connective tissue. In the 3 fetuses and in 3 autopsied children renal glomeruli were found in close relation with the TERs. In 2 cases of SCs showing cysts and TERs both structures contained spermatozoa. The histological pattern of the TERs suggest that they are wolffian derivatives which might give rise to SC cysts.

Adult↗

PubMed1987

Histological classification of spermatic cord cysts in relation to their histogenesis.

Light microscopy study of spermatic cord cysts in 26 men revealed three different histological patterns. First, cysts of probable mesothelial origin (14 cases) with an unilocular aspect: their epithelial cells showed poor cohesion and often appeared sloughed; subepithelial hyalinization or fibrin deposits were frequent. Second, cysts of probable embryonal (mesonephric) origin (8 cases): they were usually multilocular cysts and their epithelial cells showed great cohesion: zones of ciliated columnar epithelium associated with embryonal remnants displaying a similar epithelium were often found; the embryonal remnants and the cyst lumen contained spermatozoa in 2 cases. Third, cysts of doubtful origin (4 cases) showing abundant inflammatory infiltrates, which had destroyed the epithelium; the unilocular pattern observed in 3 cases suggests a mesothelial origin for these cysts, while the multilocular pattern and presence of embryonal remnants in the other case suggest an embryonal origin.

Adolescent↗

PubMed1987

Changes in the lipid inclusion/Sertoli cell cytoplasm area ratio during the cycle of the human seminiferous epithelium.

The area occupied by Sertoli cell lipid inclusions--electron-lucent lipid vacuoles (LLV) and electron-dense lipid droplets (DLD)--at each stage of the cycle of the seminiferous epithelium was measured on electron micrographs in young adults and elderly men, and expressed as the ratio "area occupied by lipid inclusions/area occupied by the Sertoli cell cytoplasm". For LLV this ratio increased from stage I to stage III, and decreased from stage IV to stage VI in young adults. These results suggest that the development of LLV is synchronized with the spermatogenic process: the residual bodies released in stages I and II are phagocytized by Sertoli cells and transformed into LLV; the amounts of LLV decrease in the subsequent stages of the cycle and increase again when new residual bodies appear. In elderly men the ratio LLV/Sertoli cell cytoplasm was 1.9-2.9 times higher than in young adults at each stage of the cycle. This increase may be related to the increased germ-cell degeneration observed in ageing testes, DLD were less abundant than LLV and the DLD/Sertoli cell cytoplasm ratio did not undergo cyclic changes in young adults or elderly men.

Adult↗