Distribución de las células presentadoras de antígenos en las glándulas salivales

Las células presentadoras de antígenos profesionales como las células de Langerhans o las células dendríticas intersticiales del tejido conectivo, son las células capturadoras de antígenos más importantes del sistema inmune. En trabajos previos describimos variaciones numéricas y estructurales de las células dendríticas; con especial referencia a las células de Langerhans, en diversos epitelios del tracto digestivo. El propósito de este trabajo fue estudiar la distribución, en forma comparativa, de las células dendríticas en glándulas salivales mayores y menores de la mucosa oral. Material y métodos: para esta investigación se utilizaron muestras de glándulas salivales mayores y menores tomadas de ratas Wistar. Las muestras fueron procesadas utilizando técnicas de microscopía óptica convencional, electrónica e inmunohistoquímica. Los resultados muestran numerosas células dendríticas en los conductos salivares excretores (con epitelio estratificado) así como en el parénquima glandular. Aunque no detectamos diferencias estadísticas significativas entre los dos componentes glandulares analizados, nuestros hallazgos sugieren que, debido a su localización, estas células cumplen un rol fundamental en las defensas inmunes de la mucosa oral.

Spatial compartmentalization of free radical formation and mitochondrial heterogeneity in bivalve gills revealed by live-imaging techniques, supplementary material

Live-imaging techniques (LIT) utilize target-specific fluorescent dyes to visualize biochemical processes using confocal and multiphoton scanning microscopy, which are increasingly employed as non-invasive approach to physiological in-vivo and ex-vivo studies. Here we report application of LIT to bivalve gills for ex-vivo analysis of gill physiology and mapping of reactive oxygen (ROS) and nitrogen (RNS) species formation in the living tissue. Our results indicate that H2O2, HOO. and ONOO- radicals (assessed through C-H2DFFDA staining) are mainly formed within the blood sinus of the filaments and are likely to be produced by hemocytes as defense against invading pathogens. The oxidative damage in these areas is controlled by enhanced CAT (catalase) activities recorded within the filaments. The outermost areas of the ciliated epithelial cells composing the filaments, concentrated the highest mitochondrial densities (MTK Deep Red 633 staining) and the most acidic pH values (as observed with ageladine-a). These mitochondria have low (depolarized) membrane potentials (D psi m) (JC-1 staining), suggesting that the high amounts of ATP required for ciliary beating may be in part produced by non-mitochondrial mechanisms, such as the enzymatic activity of an ATP-regenerating kinase. Nitric oxide (NO, DAF-2DA staining) produced in the region of the peripheral mitochondria may have an effect on mitochondrial electron transport and possibly cause the low membrane potential. High DAF-2DA staining was moreover observed in the muscle cells composing the wall of the blood vessels where NO may be involved in regulating blood vessel diameter. On the ventral bend of the gills, subepithelial mucus glands (SMG) contain large mucous vacuoles showing higher fluorescence intensities for O2.- (DHE staining) than the rest of the tissue. Given the antimicrobial properties of superoxide, release of O2.- into the mucus may help to avoid the development of microbial biofilms on the gill surface. However, cells of the ventral bends are paying a price for this antimicrobial protection, since they show significantly higher oxidative damage, according to the antioxidant enzyme activities and the carbonyl levels, than the rest of the gill tissue. This study provides the first evidence that one single epithelial cell may contain mitochondria with significantly different membrane potentials. Furthermore, we provide new insight into ROS and RNS formation in ex-vivo gill tissues which opens new perspectives for unraveling the different ecophysiological roles of ROS and RNS in multifunctional organs such as gills.

Mechanical behaviour and formation process of silkworm silk gut

High performance silk fibers were produced directly from the silk glands of silkworms ("Bombyx mori") following an alternative route to natural spinning. This route is based on a traditional procedure that consists of soaking the silk glands in a vinegar solution and stretching them by hand leading to the so called silkworm guts. Here we present, to the authors’ best knowledge, the first comprehensive study on the formation, properties and microstructure of silkworm gut fibers. Comparison of the tensile properties and microstructural organization of the silkworm guts with those of naturally spun fibers allows gain of a deeper insight into the mechanisms that lead to the formation of the fiber, as well as the relationship between the microstructure and properties of these materials. In this regard, it is proved that an acidic environment and subsequent application of tensile stress in the range of 1000 kPa are sufficient conditions for the formation of a silk fiber.

Induction of ovulation in rabbit does using purified nerve growth factor and camel seminal plasma

The presence of an ovulation-inducing factor (OIF) in the seminal plasma (SP) of several species with spontaneous and induced ovulation, including the rabbit, has been documented. Recent studies have demonstrated that the OIF in the SP of camels (SPCAM) is a nerve growth factor (β-NGF). The aim of this study was to determine if purified β-NGF from mouse submandibular glands or SPCAM could provoke ovulation induction in the rabbit doe. A total of 35 females were synchronized with 25 IU of equine chorionic gonadotropin (Serigan, Laboratorios Ovejero, Spain) and allocated into 4 groups. Forty-eight hours later (Day 0), does were given a single dose (IM) of 1 mL of saline solution (SS; n = 8); 1 mL of gonadorelin (GnRH; Inducel, Laboratorios Ovejero, Spain; n = 9); 24 µg of β-NGF (2.5S-NGF; Promega, USA; n = 10); or 1 mL of centrifuged raw camel SP (SPCAM; 127 pg mL–1 NGF; n = 8). After treatment, an empty catheter was introduced through the vagina to simulate the nervous/mechanical stimulus of coitus (4 animals per group). Plasma LH concentrations were determined in blood samples taken 30 min before treatment and at 0, 30, 60, 90, and 120 min after injection. Progesterone concentrations were assessed at 0 and 120 min and every 2 days until Day 6 after treatment. Concentrations of β-NGF in camel SP and hormone determinations were made by enzyme immunoassay. Ovulation rate (OR) was determined after euthanasia on Day 7.