Biomedical subjects

R Paniagua

Publications and source records attributed to R Paniagua.

At least 73 records · Page 4Linked to original sources

PubMed1997

Altered endothelial and smooth muscle cell reactivity caused by University of Wisconsin preservation solution in human saphenous vein.

PURPOSE: We have investigated the effect of University of Wisconsin (UW) solution at different temperatures on endothelial and smooth muscle cell function of the human saphenous vein to define the efficacy of UW solution as a preservation solution for saphenous vein conduits. METHODS: Saphenous vein segments from 38 patients undergoing coronary artery bypass surgery were examined with an isolated organ bath technique to monitor changes in vessel reactivity. RESULTS: Endothelial-dependent relaxations to acetylcholine were attenuated after incubation in UW solution at both 4 degrees C and 28 degrees C (p < 0.05, n = 10). In contrast, relaxations to sodium nitroprusside were unchanged after incubation in UW solution at both temperatures (n = 8). The responses to 90 mmol/L KCl were increased at both 4 degrees C and 28 degrees C, respectively. Tyrode's: 27.2% +/- 3.1% and 23.8% +/- 3.0%, UW: 64.7% +/- 8.0% and 73.1% +/- 11% (p < 0.001). In addition, the responses to 5-HT were enhanced at 4 degrees C and 28 degrees C (p < 0.05). In contrast, responses to noradrenaline were enhanced only at 28 degrees C compared with the responses after incubations in Tyrode's solution (p < 0.05, n = 6). Furthermore U46619 (0.3 nmol/L to 1 nmol/L) responses were augmented at 4 degrees C (p < 0.05, n = 7). The potency (pD2) values for each agonist were not significantly different after incubations in UW solution. CONCLUSIONS: We conclude that UW solution produces attenuation of acetylcholine relaxations and temperature-dependent increased reactivity of smooth-muscle cell function in the isolated human saphenous vein. These studies document the complex interactions brought about by UW solution on the different components of the vascular wall that need to be elucidated further if this solution is to attain a place in vascular preservation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed1997

Immunocytochemical electron microscopic study and western blot analysis of myosin, paramyosin and miniparamyosin in the striated muscle of the fruit fly Drosophila melanogaster and in obliquely striated and smooth muscles of the earthworm Eisenia foetida.

Miniparamyosin is a paramyosin isoform (55-60 kDa) that has been isolated in insects (Drosophila) and immunolocalized in several species of arthropods, molluscs, annelids and nematodes. In this study, the presence and distribution of this protein, in comparison with that of paramyosin and myosin, has been examined in the striated muscle (tergal depressor of trochanter) of Drosophila melanogaster, and the obliquely striated muscle (body wall) and the smooth muscle (outer layer of the pseudoheart) of the earthworm Eisenia foetida by means of immunocytochemical electron microscopic study and Western blot analysis miniparamyosin paramyosin and myosin antibodies from Drosophila. In the striated muscle of D. melanogaster, the three proteins were immunolocalized along the length of the thick filaments (A-bands). The distribution of immunogold particles along these filaments was uniform. The relative proportions miniparamyosin/paramyosin/myosin (calculated by counting the number of immunogold particles) were: 1/10/68. In the obliquely striated muscle of E. foetida, immunoreactions to the three proteins were also found in the thick filaments, and the relative proportions miniparamyosin/paramyosin/myosin were 1/2.4/6.9. However, whereas the distribution of both myosin and miniparamyosin along the thick filament length was uniform, paramyosin immunolabelling was more abundant in the extremes of thick filaments (the outer zones of A-bands in the obliquely striated muscle), where the thick filaments become thinner than in the centre (the central zone of A-bands), where these filaments are thicker. The relative proportions of paramyosin in the outer and of paramyosin in the central zones of A-bands were 4/1. This irregular distribution of paramyosin along the thick filament length might be actual but it may also be explained by the fusiform shape of thick filaments in the earthworm: assuming that paramyosin is covered by myosin, paramyosin antigens would be more exposed in the tips than in the centre of thick filaments. If miniparamyosin is, in turn, covered by paramyosin, the exposure of miniparamyosin antigens would be low even in the tips of thick filaments, and this might explain the scanty immunoreaction observed for this protein and the absence of a higher number of immunogold particles in the extremes of thick filaments. The distribution of the three proteins in the earthworm smooth muscle was as in the obliquely striated muscle, although the proportions miniparamyosin/paramyosin/myosin were 1/1.5/5.2; this is, immunoreactions to paramyosin and miniparamyosin were lower than in the obliquely striated muscle.

Animals↗

PubMed1997

Granulomatous epididymal lesion of possible ischemic origin.

In a histologic review of adult epididymides obtained at autopsy (both epididymides of 408 men) or during surgery (261 men with testicular or epididymal nontumoral pathology), a peculiar granulomatous lesion was observed in two autopsy specimens (unilateral) and three surgical specimens. The lesion was located in the caput epididymidis and consisted of a zone of necrosis that involved efferent ducts and interstitial connective tissue and was not associated with an acute inflammatory response. Immunohistochemical study with anticytokeratin antibodies showed the presence of some epithelial cells in the damaged efferent ducts. At the periphery of the lesion, where damage was less severe, the efferent ducts only showed partial necrosis of their wall through which the necrotic material was released to the ductal lumen. Inflammatory infiltrates were scanty and consisted of lymphocytes and CD68-positive macrophages. Lymphocytes were mainly located around the necrotic zone or surrounding the adjacent, well-preserved efferent ducts, whereas macrophages formed large clusters in the ductal lumen. In these clusters, cholesterol crystals and giant cells of foreign body type were frequent. Intratubular epithelial regeneration as well as proliferation of small ducts showing epithelial regeneration and numerous spermatozoa in their lumen were observed. Ceroid granulomata, spermatic granulomata, and epidermoid metaplasia of the efferent ducts were observed in some cases. On the basis of the histologic study, the following developmental stages of the lesion are suggested: ischemic necrosis, granulomatous reaction, cicatrization, and sequelae. The term "granulomatous ischemic lesion" is proposed to designate this reactive lesion.

Adult↗

PubMed1997

Immunocytochemical and quantitative study of actin, desmin and vimentin in the peritubular cells of the testes from elderly men.

A quantitative immunohistochemical study using light and electron microscopy was carried out to evaluate the morphological and quantitative distribution of the peritubular cells that immunoreact with actin, vimentin and desmin, alone or in combinations, in normal adult testes and the changes in these cells in elderly men. Seminiferous tubules in ageing testes were classified in three groups according to the degree of lamina propria thickening due to tubular sclerosis: group I, < 8 microns; group II, 8.1-12 microns; and group III, > 12.1 microns. The number of peritubular cells per cross-sectioned tubule increased from group I to group III tubules. However, no significant differences between ageing men and controls were found in the total number of peritubular cells per testis. Most peritubular cells of control testes and of group I and group II tubules displayed immunoreactivity to actin. The peritubular cells in the outermost layers of group III tubules showed no or scanty reaction. The number of actin-immunostained cells per cross-sectioned tubule decreased (P < 0.05) with tubular sclerosis. The total number of these cells per testis was significantly lower (P < 0.05) in elderly men. A narrow band around the seminiferous epithelium immunostained for desmin in control testes and group I tubules. These cells also immunoreacted to actin and vimentin. In group II and, principally, in group III tubules, only isolated peritubular cells were immunostained for desmin. The number of desmin-immunostained cells per cross-sectioned tubule decreased with tubular sclerosis and the total number per testis was also lower in elderly men. Vimentin immunostaining was observed in most peritubular cells in all tubule groups; these cells also immunoreacted to actin. Vimentin and desmin co-localized only in the inner peritubular cell layers. The number of vimentin-immunostained cells per cross-sectioned tubule increased with the degree of tubular sclerosis but the total number of these cells per testis did not differ significantly between control and ageing testes.

Actins↗

PubMed1997

Immunocytochemical electron microscopic study and Western blot analysis of caldesmon and calponin in striated muscle of the fruit fly Drosophila melanogaster and in several muscle cell types of the earthworm Eisenia foetida.

Caldesmon and calponin are two proteins that are characteristic of vertebrate smooth muscle. In invertebrates, caldesmon has only been studied in some molluscan muscles, and no previous references to calponin have been found. The aim of this paper was to investigate the presence and distribution of caldesmon and calponin in several invertebrate muscle cell types, classified according to their ultrastructural pattern: transversely striated muscle (flight muscle from Drosophila melanogaster), obliquely striated muscle (muscular body wall and inner muscular layer of the pseudoheart from the earthworm Eisenia foetida), and a muscle of doubtful classification which seems to be intermediate between smooth muscle and obliquely striated muscle (outer muscular layer of the pseudoheart, from E. foetida), using electron microscopy immunocytochemistry and Western blot analysis. Immunoreactions to both caldesmon and calponin were observed in the outer muscular layer cells from the earthworm pseudoheart but neither in the transversely striated muscle of D. melanogaster nor in the obliquely striated muscle from the earthworm. Present findings suggest that caldesmon- and calponin-like proteins are also present in invertebrate muscle cells, but only in those that are ultrastructurally similar to the vertebrate smooth muscle cells. Since discrepancies in the classification of some invertebrate muscles are common in the literature, the use of distinctive markers, such as troponin, caldesmon and calponin may improve our understanding of the nature and properties of many invertebrate muscles showing an ultrastructural pattern that does not resemble any of the classic muscle types.

Animals↗

PubMed1997

Ontogeny and localization of an oncostatin M-like protein in the rat testis: its possible role at the start of spermatogenesis.

Oncostatin M (OSM), a member of the interleukin 6 family of cytokines, was found to be highly expressed in the late fetal and early neonatal rat testis, as well as in the maturing and adult testis. Two different forms of OSM were observed, one of M(r) 22,000 and the other of M(r) 36,000. In the prepubertal rat testis [19 days post coitum, 8 days post partum (dpp), and 15 dpp], the form with the higher molecular weight prevailed, whereas in the maturing testis (30 dpp, 45 dpp, and 12 weeks post partum), a shift toward the lower molecular weight form was observed, as well as a decrease in its relative amount. By immunohistochemistry on testicular sections, OSM-specific immunostaining was observed in the interstitial tissue at every age studied. In contrast, OSM immunoreaction was localized in the Sertoli cells exclusively around the start of spermatogenesis, being strongest at 3 dpp. In vitro studies revealed that neonatal Sertoli cells produce OSM. The possible role of OSM at the start of spermatogenesis was investigated by using a coculture of Sertoli cells and gonocytes isolated from newborn rats. OSM significantly increased the survival of both Sertoli cells and gonocytes in a dose-dependent manner. The proliferative activity of the Sertoli cells was not affected by OSM, whereas that of gonocytes was increased by almost 60% after 6 days of culture. Comparison of the effect of OSM on these cocultures with other members of the interleukin 6 family of cytokines demonstrated that this factor is more potent than leukemia inhibitory factor or ciliary neurotrophic factor. On the basis of these findings, it can be concluded that OSM is present in the rat testis, and it is likely to play an important role at the start of spermatogenesis.

Animals↗

PubMed1997

Nebulin-like protein in the earthworm Eisenia foetida. Immunocytochemical electron microscopic study and western blot analysis of several muscle cell types.

Nebulin is a giant protein (500-900 kDa), which has been reported only in the skeletal muscle (not in cardiac muscle) of vertebrates. The possible presence and distribution of nebulin-like proteins in obliquely striated muscles (body wall and inner muscular layer of the pseudoheart) and smooth muscle (outer muscular layer of the pseudoheart) from the earthworm Eisenia foetida have been examined by means of Western blotting analysis and immunoelectron microscopy, using antibodies against mouse nebulin. The results were compared with those obtained in skeletal, cardiac and smooth muscles of the mouse. In the mouse, immunoreaction to nebulin was observed only in the skeletal muscle and extended along the length of the thin filament. In the earthworm, immunoreaction to a nebulin-like protein was found in the muscle of the body wall and the inner muscular layer of the pseudoheart, but not in the outer muscular layer of the pseudoheart. By electron microscopy, immunolabeling to this protein was observed along the whole length of the thin filament. Western blotting analysis of this nebulin-like protein showed a single band at an estimated molecular mass between 350 and 450 kDa that is slightly lower than that of mouse skeletal muscle nebulin.

Animals↗

PubMed1996

Immunohistochemical study and western blotting analysis of titin-like proteins in the striated muscle of Drosophila melanogaster and in the striated and smooth muscle of the oligochaete Eisenia foetida.

The presence and distribution of titin-like proteins have been examined in transversely striated muscle of Drosophila melanogaster, in obliquely striated muscles (body wall and inner muscular layer of the pseudoheart) and smooth muscle (outer muscular layer of the pseudoheart) from the earthworm Eisenia foetida by means of Western blotting analysis, light microscopy immunohistochemistry, and electron microscopy immunogold labeling, using antibodies anti vertebrate (chicken) titin (3,000 kDa) and arthropod (D. melanogaster) mini-titin (twitchin or projectin) (700 kDa). To determine whether these antibodies immunoreact non-specifically against vertebrate titin, mouse skeletal muscle was also studied. As negative control, mouse smooth muscle was used. Immunoreaction to mini-titin was found in all the invertebrate muscles studied. For each of these muscles, Western blotting analysis of mini-titin showed a single band, at approximately 700 kDa. Electron microscopy immunolabeling to this protein was observed along the whole sarcomere length (A bands and I bands) in both transversely striated muscles of the insect and obliquely striated muscles of the earthworm, although the number of immunogold particles was more abundant in the insect muscles. Mini-titin immunolabeling was also observed in the smooth muscle cells that formed the outer layer of the earthworm pseudoheart although in lower amounts than in the obliquely striated muscle. The absence of true sarcomeres in the smooth muscle cells did not permit to determine the extension of mini-titin immunolabeling. No immunoreaction to this protein was found in the striated and smooth muscles of the mouse. Immunoreaction to titin was only observed in the mouse skeletal muscle, in which both A bands and I bands appeared immunolabeled. Present results show that mini-titin in the invertebrate muscles studied differs immunohistochemically from vertebrate titin and, in contrast with titin, mini-titin is also present in invertebrate smooth muscles.

Animals↗

PubMed1996

Testicular cell cytoskeleton in the newt, Triturus marmoratus marmoratus, during the annual cycle.

Light and electron microscopy immunohistochemical studies and Western blotting analysis of cytoskeletal proteins have been carried out in the testis of the marbled newt (Triturus marmoratus marmoratus) during the annual testicular cycle. The present findings revealed homologies and differences with regard to those reported in the testes of mammals and other vertebrates. Changes in immunohistochemical expression have also been detected in the course of the annual cycle. Actin and tubulin, which were scanty and diffusely located in spermatogonia and spermatocytes, increased their expression and reorganized during spermiogenesis. Vimentin and keratin, undetected in spermatogonia and spermatocytes, were expressed in differentiating spermatids and spermatozoa. In these cells, actin might be related with the connection of the axial fiber to the undulating membrane and the coordination of movement by both structures, while vimentin might be involved in the maintenance of the spatial relationship between the axoneme and the marginal fiber. During the first stages of spermatogenesis, the cytoplasm of Sertoli cells (follicular cells) showed a diffuse immunoreaction to actin, myosin, and tubulin and no vimentin immunolabeling. In advanced spermiogenesis, the follicular cells showed an intense immunoreaction to actin, myosin, tubulin, and vimentin in the apical projections that surrounded the spermatid heads. These apical cytoskeletal components might be involved in spermatid elongation, since the spermatids display no manchette, and in spermatozoon positioning and grouping. The colocalization of myosin and actin in the follicular cells suggests that actin filaments from contractile bundles and that contraction might be involved in changes in the Sertoli cell shape that accompany germ cell development during spermatogenesis. The interstitial cells immunostained to actin, myosin, tubulin, and vimentin. These cells, together with follicular cells, seemed to form the glandular tissue cells which showed a similar immunophenotype. The cells that surrounded the efferent duct epithelium immunostained to desmin, and they are probably contractile cells involved in sperm evacuation.

Activity Cycles↗

PubMed1996

Immunocytochemical electron microscopic study and Western blot analysis of troponin in striated muscle of the fruit fly Drosophila melanogaster and in several muscle cell types of the earthworm Eisenia foetida.

BACKGROUND: There is little information about troponin in invertebrate muscles, and no previous references to this protein in annelid muscles have been found. The aim of this paper was to study the presence and distribution of troponin in different muscle cell types from the earthworm Eisenia foetida (the muscular body wall, and the inner and outer muscular layer of the pseudoheart). These results were compared with those obtained in the transversely striated muscle of Drosophila melanogaster and in skeletal and smooth muscles of the mouse. METHODS: Immunocytochemical electron microscopic study and Western blot analysis using anti-TnT antibodies were employed in this study. RESULTS: Troponin immunoreaction was detected in the mouse skeletal muscle, the fly flight muscle, and earthworm obliquely striated muscles (body wall musculature and inner muscular layer of the pseudoheart). Immunolabeling for TnT in all these muscle cells appeared in moderate amounts at any point along the sarcomere length, except for the central zone of the A band (H band). This suggests that troponin molecules were located along the thin filaments. The density of immunogold particles was similar in the three muscles, and thus the amount of troponin in each muscle type was proportional to the number and length of actin filaments in each. Troponin was found in neither the mouse smooth muscle nor the outer muscular layer of the earthworm pseudoheart. The latter muscle showed an ultrastructural pattern that was intermediate between obliquely striated and smooth muscle. The estimated molecular weight for TnT in the earthworm was 55 kDa; this is higher than the weight of this protein in the mouse skeletal muscle (40 kDa) but similar to that of the D. melanogaster muscle (52 kDa). CONCLUSIONS: Troponin is present in both types of striated muscle (transversely striated and obliquely striated) of the earthworm with a distribution that is very similar to that observed in the mammalian striated muscle. As in vertebrates, troponin is absent in the smooth muscle of the earthworm. Discrepancies in the classification of some invertebrate muscles are common in the literature, and the use of distinctive markers, such as troponin, may improve our understanding of the nature and properties of many invertebrate muscles showing an ultrastructural pattern that does not resemble any of the classic muscle types.

Animals↗

PubMed1996

Immunocytochemical electron microscopic study and western blot analysis of paramyosin in different invertebrate muscle cell types of the fruit fly Drosophila melanogaster, the earthworm Eisenia foetida, and the snail Helix aspersa.

The presence and distribution pattern of paramyosin have been examined in different invertebrate muscle cell types by means of Western blot analysis and electron microscopy immunogold labelling. The muscles studied were: transversely striated muscle with continuous Z lines (flight muscle from Drosophila melanogaster), transversely striated muscle with discontinuous Z lines (heart muscle from the snail Helix aspersa), obliquely striated body wall muscle from the earthworm Eisenia foetida, and smooth muscles (retractor muscle from the snail and pseudoheart outer muscular layer from the earthworm). Paramyosin-like immunoreactivity was localized in thick filaments of all muscles studied. Immunogold particle density was similar along the whole thick filament length in insect flight muscle but it predominated in filament tips of fusiform thick filaments in both snail heart and earthworm body wall musculature when these filaments were observed in longitudinal sections. In obliquely sectioned thick filaments, immunolabelling was more abundant at the sites where filaments disappeared from the section. These results agree with the notion that paramyosin extended along the whole filament length, but that it can only be immunolabelled when it is not covered by myosin. In all muscles examined, immunolabelling density was lower in cross-sectioned myofilaments than in longitudinally sectioned myofilaments. This suggests that paramyosin does not form a continuous filament. The results of a semiquantitative analysis of paramyosin-like immunoreactivity indicated that it was more abundant in striated than in smooth muscles, and that, within striated muscles, transversely striated muscles contain more paramyosin than obliquely striated muscles.

Animals↗

PubMed1996

Cystic transformation and calcium oxalate deposits in rete testis and efferent ducts in dialysis patients.

The histological study of the testes and epididymides obtained from autopsies of 24 men with chronic renal insufficiency revealed bilateral cystic transformation of the rete testis and efferent ducts in patients who underwent hemodialysis or peritoneal dialysis, but not in patients who did not receive this treatment. The lesion was associated with an accumulation of crystalline calcium oxalate deposits in the lumen of the rete testis and efferent ducts, and in the connective tissue adjacent to these excretory ducts. The rete testis epithelium showed columnar transformation with occasional papillary proliferations. Neither atypias or mitoses were observed. In three specimens, fibrosis and giant cell reactions was also present in the rete testis at the level of crystalline deposits. In three specimens, the caput epididymidis was enlarged, and the efferent ducts showed an increase in both tubular diameter and epithelial height, irregular outline, and development of diverticula. The lesions appeared within 30 months after the onset of dialysis.

Adult↗

PubMed1996

Light and electron microscopic immunohistochemical localization of protein gene product 9.5 and ubiquitin immunoreactivities in the human epididymis and vas deferens.

The distribution of protein gene product 9.5 (PGP) and ubiquitin immunoreactivities in the ductuli efferentes, ductus epididymidis, and ductus deferens of humans was studied by Western blot analyses and light and electron microscopic immunocytochemistry. PGP immunoreactivity was intense in the ductuli efferentes and weak in the ductus epididymidis and ductus deferens, while ubiquitin immunoreactivity was intense in the ductuli efferentes and ductus epididymidis and very weak in the ductus deferens. In the ductuli efferentes epithelium, PGP immunolabeling was observed in the cytoplasm of principal cells, whereas ubiquitin immunoreactivity was found in the nucleus and cytoplasm of principal cells and ciliated cells. In the ductus epididymidis epithelium, only scattered cells (mitochondria-rich cells) showed PGP immunoreaction in their cytoplasm, whereas ubiquitin immunostaining was detected in the nucleus and cytoplasm of most epithelial cells, except for the cauda, where ubiquitin immunolabeling was observed only in the nuclei. The ductus deferens showed no immunostaining for PGP, and only nuclear immunoreactivity to ubiquitin. The ultrastructural localization of PGP immunoreactivity was in the apical cytosol and microvilli. In addition to these locations, ubiquitin immunoreactivity was also found in the nucleus of all cell types and cilia of ciliated cells. Although the distribution of PGP and ubiquitin immunoreactivities in humans differs from that reported in rats, it seems that PGP and ubiquitinated proteins are secreted into the epididymal lumen in both species.

Adult↗

PubMed1996

Cystic transformation of the rete testis.

In a review of the testicular and epididymal specimens obtained from autopsies (1,798 men) or surgery (518 men), cystic transformation of the rete testis (CTRT) was found in 20 autopsies and 18 surgical specimens. When both testes were studied (autopsies), the lesion was bilateral. Ultrasonography revealed a widened mediastinum testis showing small hypoechoic areas. Arteriography showed thin or irregularly outlined testicular arteries, and the epididymal artery was lacking or appeared stenosed. Simple CTRT (without epithelial alteration) was found in both testes of 17 autopsied patients (all were elderly men) and in eight surgically removed testes from patients with sarcoma, tuberculous orchidoepididymitis, or hematocele. The most frequent epididymal lesion was bilateral efferent duct atrophy. In three patients, the rete testis presented nodular proliferation of calcifying connective tissue. CTRT with columnar transformation of the rete testis epithelium was observed in both testes from three patients with alcoholic cirrhosis, and in 10 surgically removed testes from patients with testicular tumor, cryptorchidism, or nonspecific orchitis. In cirrhotic patients, the efferent ducts appeared atrophied. In patients with testicular tumors, the efferent ducts were infiltrated by carcinoma in situ cells (CISs) and often contained granular material, cell debris, or hyaline globules. In both kinds of CTRT (without or with epithelial metaplasia), the most frequent seminiferous tubule lesions were tubular ectasia, hypospermatogenesis, tubular sclerosis, spermatogonium arrest, and sloughing of immature germ cells (spermatids and spermatocytes). The mechanism leading to CTRT might be mechanic (compression of the epididymis by an epididymal tumor or a spermatic cord tumor, or the result of a long-standing epididymitis or traumatic hemocele); ischemic (autopsied elderly men); hormonal (cirrhotic patients); malformative (cryptorchidism); or unknown (the remaining cases).

Adolescent↗

PubMed1996

Fusocellular gonadal stromal tumour of the testis with epithelial and myoid differentiation.

We describe an unusual fusocellular gonadal stromal tumour with a benign behaviour in the left testis from a 16-year-old man. The neoplasm consisted of a non-encapsulated proliferation of irregularly arranged, fusiform cell bundles in fibrous connective tissue. The tumour cells contained a slightly infolded nucleus, some dilated rough endoplasmic reticulum cisternae, abundant filament bundles which connected to subplasmalemmal electron-dense bodies, pinocytotic vesicles and a discontinuous basal lamina. The intercellular spaces were narrow and the tumour cells were joined by desmosomes. These cells were immunoreactive for muscle actin, alpha-actinin and vimentin. Focal immunostaining for collagen type IV was observed around the cells. No immunoreactivity for keratins, desmin S-100 protein or XIIIa factor was found. The findings suggest that the tumour arose from the peritubular myoid cells.

Actins↗

PubMed1996

Leukemia inhibitory factor and ciliary neurotropic factor promote the survival of Sertoli cells and gonocytes in coculture system.

Leukemia inhibitory factor (LIF) and ciliary neurotropic factor (CNTF) were found to be pleiotropic modulators of Sertoli cell and gonocyte development (both isolated from the neonatal rat testis) in a coculture system, whereas IL-6, another member of this cytokine family, had no effect on these cells. LIF and CNTF significantly enhanced the survival of the Sertoli cells in a dose- and time-dependent manner. The effect of LIF on the Sertoli cells was significant at a concentration of 1 ng/ml after 3 or 6 days of culture, whereas CNTF had a significant effect at 10 ng/ml. Neither LIF nor CNTF had an effect on Sertoli cell proliferation. The survival of proliferating gonocytes (isolated from 3-day-old rats testes) was also significantly higher in cultures to which LIF (7.5 ng/ml) or CNTF (10 ng/ml) was added. No effect of these cytokines was found on the mitotic activity of proliferating gonocytes. However, LIF (7.5 ng/ml) stimulated the proliferation of quiescent gonocytes (isolated from day 1 testes) after 3 days of culture. Combinations of LIF (or CNTF) with fibroblast growth factor 2 (10 ng/ml) and steel factor (50 ng/ml) did not further improve the long term culture of the gonocytes. LIf- and CNTF-like proteins of the expected molecular masses (32,000 and 22,000 daltons, respectively, under reducing conditions) were found by Western blotting in testicular extracts of 3-day-old rats. Taken together, these results indicate that LIF or CNTF may play a role at the start of the spermatogenesis. The characterization of receptors for LIF or CNTF on the gonocytes and/or neonatal Sertoli cells will aid in a better understanding of the physiological role of these cytokines in the reproductive system.

Animals↗

PubMed1996

Lectin histochemistry in the human epididymis.

A histochemical study using lectins to identify glycoconjugates present in the efferent ducts and ductus epididymidis of men without testicular or related disease was carried out. The lectins used and the oligosaccharide residues linked were: wheat germ agglutinin (WGA) for beta-N-acetylglucosamine and sialic acid, concanavalin A (ConA) for alpha-mannose, Ulex europaeus agglutinin (UEA-I) for alpha-fucose, Dolichos biflorus agglutinin (DBA) for alpha-N-acetylgalactosamine, soy bean agglutinin (SBA) for beta-N-acetylgalactosamine, and peanut agglutinin (PNA) for beta-galactose. The lectin-binding pattern in the human epididymis presents similarities and differences to those observed in other mammals which also showed differences between species. The present results revealed that regional differences along the human ductus epididymidis were less pronounced than those reported in other mammals. The epithelial cells in the efferent ducts reacted positively to WGA. All along the length of the ductus epididymidis, the principal cells and the luminal content showed staining affinity for WGA and ConA. The epididymal principal cells and luminal content also reacted positively to DBA for alpha-N-acetylgalactosamine but only in the cauda epididymidis. A positive reaction to UEA-I was observed only in the luminal content of the cauda epididymidis. This finding suggests that changes in the oligosaccharide chains of secretions leading to a positive UEA-I reaction occur in the cauda epididymidis. The epididymal principal cells showed positive reactions to SBA and PNA over the apical microvilli but not in the cytoplasm. The reaction was observed in the caput and corpus epididymidis but not in the cauda. Positive reactions to SBA and PNA were also detected in the epididymal fluid and in the cytoplasm of mitochondria-rich cells (a minor population of epididymal epithelial cells). These cells also reacted to other lectins such as WGA, ConA and DBA, which were also detected in the principal cells.

Acetylgalactosamine↗

PubMed1996

Ultrastructure of invertebrate muscle cell types.

The muscular cells of invertebrates can be divided into three major classes on the basis of their striation pattern: transversely striated, obliquely striated, or smooth muscle. Transversely striated muscles have either continuous or discontinuous Z lines and, thus, can be subdivided into two types respectively. Of all invertebrate muscles, the transversely striated muscle with continuous Z lines is the most similar to the vertebrate skeletal muscle and is present in arthropods, whose musculature (including the visceral muscles) only consists of this cell type. These muscles are multinucleate cells that contain myofibrils showing well-defined sarcomeres. Transversely striated muscles with discontinuous Z lines, consisting of multiple small electrondense patches, are found in the translucent portions of adductor muscles of some bivalves and in the heart muscle of the gastropods. This muscle is formed by mononucleated cells with centrally-located nuclei and a single myofibril. The obliquely striated muscle appears in nematodes, annelids, molluscs, brachiopods and chaetognathes and consists of mononucleated cells with both thick and thin myofilaments which form sarcomeres delimited by Z lines. Myofilaments are not perpendicular but oblique to the Z lines, so that both A and I bands may be seen together in each of the three spatial planes of view. Smooth muscle has been reported in coelenterates, annelids, molluscs, brachiopods and echinoderms, but is lacking in arthropods. These muscle cells have a centrally-located nucleus and abundant thin and thick myofilaments without apparent sarcomeres. The most relevant characteristics of invertebrate muscle cells are the following. The thick (myosin) myofilaments show a variable length (from 2.2 microns up to 6 microns) and width (from 14 nm up to 231 nm) and contain a central core of paramyosin, which is absent in vertebrate muscles. Thick filaments are homogenous in transversely striated muscles and either homogeneous or fusiform in the obliquely striated and smooth muscles. Thin filaments measure 6 nm in diameter. They contain tropomyosin and, only in striated muscles, also troponin. The thin/thick filament ratio varies from 3/1 to 6/1, even in smooth muscles. The plaques for filament anchorage (Z lines in striated muscles or electrondense bodies in smooth muscles) contain alpha-actinin. The striated (transversely or obliquely) muscles show long sarcomeres (up to 9 microns) and the number of thin filaments around each thick filament varies from 3 to 12, so that each thin filament is shared by two thick filaments. Z lines in the striated muscles show a variety of structures that differ from one species to another (filament bundles in nematodes, bars in annelids, small patches in molluscs, etc). Many striated muscles contain titin (connectin) and intermediate filaments and display a sarcotubular system consisting of T tubules and sarcoplasmic reticulum tubules. Both structures form dyads and, more rarely, triads. The location of T tubules as well as the configuration and distribution of sarcoplasmic reticulum vary among muscles and species. Invertebrate smooth muscle differs from that of vertebrates principally in the higher proportion and larger diameter of thick myofilaments. These may be fusiform and their size and number may vary widely among cells. These muscle cells may be classified by the characteristics of both the thick filaments and the electrondense bodies for filament anchorage.

Animals↗