Changes in the expression of the potassium channels TASK1, TASK3 and TRESK in a rat model of oral squamous cell carcinoma and their relation to malignancy.

Objectives: Potassium channels have been proposed to promote cancer cell proliferation and metastases. Thus, we investigated the expression pattern of three 2-pore domain potassium channels (K2Ps) TASK1, TASK3 and TRESK in advanced oral squamous cell carcinoma (OSCC), the commonest oral malignancy.

Design: We used 4-nitroquinoline-1-oxide (4-NQO) to induce high grade OSCC in male adult rats.

Glycosidases Interact Selectively With Mannose-6-Phosphate Receptors of Bull Spermatozoa.

Glycosidases may play a role in sperm maturation during epididymal transit. In this work, we describe the interaction of these enzymes with bull spermatozoa. We found that β-galactosidase associated to spermatozoa can be released under low ionic strength conditions, whereas the interaction of N-acetyl-β-D-glucosaminidase and β-glucuronidase with spermatozoa appeared to be stronger.

Dissociation of the X chromosome from the synaptonemal complex in the XY body of the rodent Galea musteloides.

The XY body from spermatocytes of the rodent Galea musteloides shows progressive changes of the synaptonemal complex (SC) axes and the X-chromatin during pachynema. There is a gross thickening of the X-axis and the formation of a large X chromosome loop at mid and late pachytene stages. The SC proteins synaptonemal complex protein 3 (SYCP3), synaptonemal complex protein 1, and synaptonemal complex central element protein 3 and the proteins breast cancer 1, MutL homolog 1 (MLH1), and radiation-repair 51 (related to meiotic processes), the cohesin structural maintenance of chromosome 3, the centromeric protein (with CREST antibody), and the silenced chromatin (with phosphorylated (139ph) H2A histone family, member X (γ-H2AX) antibody) were analyzed in this XY body.

The actin filament network associated to Sertoli cell ectoplasmic specializations.

Junctional devices in Sertoli cells conform the blood-testis barrier and play a key role in maturation and differentiation of germ cells. The spacial distribution of ectoplasmic specializations of Sertoli cells was studied by beta-actin immunolabelling, using laser confocal and transmission electron microscopy. For confocal microscopy, beta-actin immunolabelling of ectoplasmic specializations was studied over the background of either prosaposin or glutaredoxin immunolabelling of the Sertoli cytoplasm.

Nuclear pores in luteal cells during pregnancy and after parturition and pup removal in the rat. A freeze-fracture study.

In a previous paper we described a pronounced increase of apoptotic nuclei in rat corpus luteum of pregnancy whose programmed chromatin degeneration was induced by the progesterone antagonist mifepristone. Those observations encouraged us to study the apoptotic nuclear membrane during pregnancy and after parturition and pup removal, by using a freeze-fracture technique which allows us to observe 'en face' the nuclear envelop and also permits nuclear pore counting. This study was complemented with the TUNEL assay (TdT-mediated dUTP nick-end labelling).

Administration of noradrenaline in the autonomic ganglia modifies the testosterone release from the testis using an ex vivo system.

The male gonad receives nerve fibres from the autonomic ganglionic system. These fibres converge on the testis along two pathways, the superior and the inferior spermatic nerves. The superior spermatic nerve runs from the superior mesenteric ganglion alongside the testicular artery, whereas the inferior spermatic nerve originates in inferior mesenteric ganglion, accompanies the vas deferens and penetrates the inferior pole of the testis.

Apoptosis and blood-testis barrier during the first spermatogenic wave in the pubertal rat.

This research explores the initial assembly of the blood-testis barrier (BTB) during puberty, when a massive physiological apoptosis in the first spermatogenic wave takes place. Fragments of testis from 14- to 20-day-old rats were studied by conventional transmission electron microscopic techniques. Lanthanum hydroxide was used as an intercellular tracer.

Deterioration of the Langerhans cell network of the human gingival epithelium with aging.

Dendritic cells (DCs) are the professional antigen-presenting cells responsible for initiating of the immune response. Langerhans cells (LCs) are a type of DC that is a permanent resident of the oral epithelium. LCs are organized conforming a network in such a way as to maximize their surface area for efficient apprehension of antigens.

Variation in Langerhans cell number and morphology between the upper and lower regions of the human esophageal epithelium.

Langerhans cells (LCs) are dendritic components of stratified epithelia, presenting antigens to other cells of the immune system that play a crucial role in local defense. The paucity of information about their significance in the esophageal mucosa was addressed by studying their distribution and morphology in this particular location. LCs were identified by immunohistochemical detection of CD1a, a cell-specific marker, using a monoclonal antibody, as well as by electron microscopic identification of characteristic Birbeck granules, among other typical morphological features.

Spermatogenesis and blood-testis barrier in rats after long-term Vitamin A deprivation.

It has been established that experimental avitaminosis A in rats results in a 'Sertoli cell-only situation' after about 10 weeks, and that replacing the vitamin immediately reinitiates spermatogenesis. The present study deals with testicular recovery after prolonged deprivation (up to 19 weeks). The Sertoli cell-only situation reached under this condition was thought to be refractory to Vitamin A replacement.

Administration of acetylcholine to the spermatic nerve plexus inhibits testosterone secretion in an in vitro isolated rat testis-nerve plexus system.

Strong evidence indicated that spermatic nerves are involved in the regulation of testosterone secretion. Our previous work showed that the inferior spermatic nerves play a more significant role than the superior ones in the regulation of testosterone secretion. However, it is unknown whether traditional neurotransmitters are involved in this regulation.