Testicular Germ Cell Tumours and Proprotein Convertases.

Testicular Germ Cell Tumours (TGCT) are widely considered a "curable cancer" due to their exceptionally high survival rate, even if it is reduced by many years after the diagnosis due to metastases and relapses. The most common therapeutic approach to TGCTs has not changed in the last 50 years despite its multiple long-term side effects, and because it is the most common malignancy in young Caucasian men, much research is needed to better the quality of life of the many survivors. Proprotein Convertases (PC) are nine serine proteases responsible for the maturation of inactive proproteins with many diverse functions.

Zona Pellucida sperm-binding protein 3 receptor distribution during Gopc globozoospermic spermatogenesis.

Globozoospermia is a type of teratozoospermia characterized by round morphology of the sperm head. Gopc infertile globozoospermic murine model has failures during spermiogenesis, such as the incorrect biogenesis of the acrosome, disorganized acroplaxome and manchette, round nuclei and spiral flagella. In this study, Western blot, RT-PCR, immunohistochemistry and immunogold were done for the localization of the acrosome protein Zona Pellucida sperm-binding protein 3 receptor (ZP3R), also called sp56, in wild type and Gopc mice testis.

Identification of sugar moieties in chief cells of the rat fundic gastric glands.

Many studies have been conducted to determine the composition of the glycoconjugates of the mucus-secreting cells of the fundic glands of the stomach. However, the chief cells of these glands have been largely ignored because they secrete mainly zymogens with a lower glycosylation. The aim of this work was to analyze the glycoconjugates of the gastric chief cells by a battery of 17 different lectins, recognizing Fucose, N-acetylgalactosamine, Galactose, N-acetylneuraminic acid, N-acetylglucosamine and Mannose containing oligosaccharides.

OPENCRONIC Study. Knowledge and Experiences of Spanish Patients and Carers about Chronic Disease.

: Chronic diseases are currently the main cause of morbidity and mortality and represent a major challenge to healthcare systems. The objective of this study is to know Spanish public opinion about chronic disease and how it affects their daily lives. : Through a telephone or online survey of 24 questions, data was gathered on the characteristics of the respondents and their knowledge and experiences of chronic diseases.

Different Glycoconjugate Content in Mucus Secreting Cells of the Rat Fundic Gastric Glands.

The fundic glands of the stomach contain two types of mucous cells: surface mucous cells (SMCs) located at the surface of the stomach and the pits, and mucous neck cells (MNCs) situated in the neck of the glands. They produce mucins, highly glycosylated proteins. Very little is known about the glycan composition of these mucins and of gastric secretion in general.

Transdifferentiation of mucous neck cells into chief cells in fundic gastric glands shown by GNA lectin histochemistry.

The epithelium of the gastric mucosa and its glands in the corpus of rat stomach contains mucous surface cells (MSCs), parietal cells, mucous neck cells (MNCs), zymogenic or chief cells (ZCs), several types of enteroendocrine cells, and intermediate cells with characteristics between MNCs and ZCs also called transitional or prezymogenic cells (pre-ZCs). The aim of our work was to analyze the expression of Mannose (Man) in the rat gastric glands by means of Galanthus nivalis lectin (GNA) histochemistry to identify the differences between MNC, pre-ZCs and ZCs and to establish the relationships between these cells. Most of the cytoplasm of MNCs was negative for GNA histochemistry.

The death of sertoli cells and the capacity to phagocytize elongated spermatids during testicular regression due to short photoperiod in Syrian hamster (Mesocricetus auratus).

In the Syrian hamster (Mesocricetus auratus), an animal that displays testicular regression due to short photoperiod, germ cells are removed by apoptosis during this process and the apoptotic remains are phagocytized by Sertoli cells. The aim of this work was to investigate morphologically whether the testicular regression process due to short photoperiod leads to the apoptosis of Sertoli cells, and whether, during testicular regression, the elongated spermatids are eliminated through phagocytosis by Sertoli cells. To this end, we studied testis sections during testicular regression in Syrian hamster subjected to short photoperiod by means of several morphological techniques using conventional light microscopy (hematoxylin and eosin [H&E], semi-thin section vimentin, immunohistochemistry, SBA lectin, and TUNEL staining), fluorescence microscopy, and transmission electron microscopy (TEM).

Histochemical identification of sialylated glycans in Xenopus laevis testis.

Carbohydrate chains of glycoprotein and glycosphingolipids are highly diverse molecules involved in many cell functions, including cell recognition, adhesion and signalling. Sialylated glycans are of special interest because the terminal position of sialic acid (NeuAc) in glycans linked by different ways to subterminal monosaccharides has been shown to be involved in several biological processes, as occurs with gangliosides, which have been reported as being essential in spermatogenesis in mammals. Some glycan-binding proteins, the lectins, which specifically recognize glycan sequences, have been extensively used to characterize tissue and cell carbohydrates by means of cytochemical techniques.

Galactosides in glycoconjugates of Xenopus laevis testis shown by lectin histochemistry.

The implication of galactosides and other glycoconjugates on spermatogenesis has been previously reported. Glycans show such a complex structure that it makes them very difficult to analyze. Lectin histochemistry is a helpful tool for the study of glycan composition.

Identification of N-acetylgalactosamine in carbohydrates of Xenopus laevis testis.

Identification of glycans in amphibian testis has shown the existence of N-acetylgalactosamine (GalNAc)-containing carbohydrates. Labeling of the sperm acrosome with GalNAc-binding lectins has allowed the identification of GalNAc-containing glycans in this organelle. Futhermore, this specific labeling of the acrosome has allowed the study of acrosomal biogenesis by lectin histochemistry.

Identification of fucosylated glycoconjugates in Xenopus laevis testis by lectin histochemistry.

Glycoconjugates play roles in many physiological and pathological processes. Previous works have shown important functions mediated by glycans in spermatogenesis, and the carbohydrate composition of testis has been studied by several approaches, including lectin-histochemical methods. However, the testis of Xenopus laevis, an animal model extensively employed in biochemical, cell and developmental research, has not yet been analysed.

Acrosome biosynthesis in spermatocytes and spermatids revealed by HPA lectin cytochemistry.

The origin of the acrosome is controversial, because of both its lysosomal nature and at the moment of its appearance, which seems to be species-specific. Considering the amazing organization shown by the acrosome of some urodele amphibians, HPA-colloidal gold cytochemistry was used to analyze the biogenesis of the acrosome in the urodele Pleurodeles waltl at electron microscopy level. The results showed that HPA-labeling is useful to label the acrosome and its precursor vesicles and, consequently, HPA-histochemistry could be used as a marker of acrosomal content.

Histochemical demonstration of two subtypes of O-linked oligosaccharides in the rat gastric glands.

The gastric glands synthesize glycoproteins whose oligosaccharides are linked to the peptide core mainly by the O-glycosidic bond, specifically removed by beta-elimination procedure. Our aim was to research the possibility of the existence of two subtypes of O-linked oligosaccharides with a different behavior to the removal procedure. The lectins from peanut (PNA) and Maackia amurensis (MAA-I) were histochemically used as markers of the O-linked oligosaccharides.

Identification of mannose moieties in N- and O-linked oligosaccharides of the primordial germ cells of Xenopus embryos.

The presence of mannose (Man) in the glycoconjugates of primordial germ cells (PGCs) of Xenopus embryos was elucidated by lectin histochemistry with Concanavalin A (Con A) and snowdrop (Galanthus nivalis) bulb lectin (GNA), in combination with deglycosylative pretreatments: beta-elimination, which removes O-linked oligosaccharides, and incubation with Peptide N glycosidase F (PNGase F), which removes N-linked glycan chains. In addition, histochemistry with Con A, which binds to Man and glucose (Glc), was also performed after glucose-oxidase incubation, which converts Glc into gluconic acid, and GNA was carried out after acid hydrolysis, which removes terminal sialic acid (NeuAc) moieties. PGCs were analyzed during their migration over the mesentery until the genital ridge, and after colonization of this gonad anlage.

Glycoconjugates of the urodele amphibian testis shown by lectin cytochemical methods.

Lectin histochemistry is a useful method that allows the in situ identification of the terminal sugar moieties of the carbohydrates that form the glycoconjugates. Moreover, when it is combined with chemical or enzymatic deglycosylation pretreatments, lectin histochemistry can be employed to determine if carbohydrates are linked to the protein core by means of an N- or O-glycosidic linkage or, indeed, to partially sequence the sugar chains. One of the most interesting model organs for the study of spermatogenesis is the amphibian urodele testis.

GalNAc moieties in O-linked oligosaccharides of the primordial germ cells of Xenopus embryos.

Glycoconjugates could play a role in cell adhesion and migration mechanisms, including the locomotive movements of the primordial germ cells (PGCs) during the development of the embryo. In the present work, we have studied by lectin histochemistry the presence of N-acetylgalactosamine (GalNAc) in the glycans of the Xenopus PGCs, as a first approach to identifying their glycoconjugates which could be involved in the migration mechanism. The PGCs were negative for three of the GalNAc-binding lectins employed (from soybean, SBA; from lima bean, LBA; and from snail, HPA).

Effect of photoperiod on testicular function in blinded and non-blinded marbled newts, Triturus marmoratus (caudata, salamandridae).

Adult male marbled newts (Triturus marmoratus) were collected at the beginning of the spermatogenetic period and exposed to different photoperiods (natural photoperiod with progressively increasing daylengths, total darkness, 8L:16D, 12L:12D, 16L:8D, and continuous light) for 3 months at 20°C. To evaluate the effect of photoperiodic input via pineal gland photoreceptors, two additional groups of newts were blinded by a non-aggressive method (an elastic rubber cap was adjusted to the head to cover the eyes but not the pineal photoreceptors). These animals were exposed either to the natural photoperiod or to 12 hr of light per day.