Evaluation of compound 48/80 as a model of immediate hypersensitivity in the skin of dogs

Abstract The macroscopic and histological effects of intradermal injection of compound 48/80 were investigated in dogs. Dose-dependent increases in skin-fold thickness were induced at injection sites and histopathological examination of skin biopsy specimens revealed evidence of mast cell degranulation and cellular infiltration. Intradermal compound 48/80 may form a useful model for studies of canine hypersensitivity disorders including atopic dermatitis. Résumé— Les effets macroscopiques et histologiques de l'injection intradermique du composé 48/80 ont étéétudiés chez le chien. Une augmentation dose-dépendante de l'épaisseur du pli de peau a été induite au niveau des points d'injection et l'examen histopathologique de biopsies cutanées a démontré une dégranulation mastocytaire et une infiltration cellulaire. L'injection du composé 48/80 peut constituer un modèle utile pour l'étude de réactions d'hypersensibilité chez le chien, comme la dermatite atopique. [Mason, I., Lloyd, D. Evaluation of compound 48/80 as a skin model of immediate hypersensitivity in the skin of dogs (Evaluation du compose 48/80 comme modele d'hypersensibilité cutanee immediate chez le chien). Veterinary Dermatology 1996; 7 : 81–83.] Resumen Se investigaron los efectos macroscópicos e histológicos de la inyección intradérmica del compuesto 48/80. Estas inyecciones provocaron engrosamiento del grosor cutáneo proporcional a la dosis administrada y el examen histopatológico de biopsias cutáneas reveló degranulación de mastocitos e infiltración celular. El compuesto 48/80 puede constituir un modelo útil para el estudio de las hipersensibilidades caninas, incluyendo la dermatitis atópica. [Mason, I., Lloyd, D. Evaluation of compound 48/80 as a skin model of immediate hypersensitivity in the skin of dogs (Evaluación del compuesto 48/80 como modelo de hipersensibilidad inmediata en la piel del perro). Veterinary Dermatology 1996; 7 : 81–83.] Zusammenfassung— Die makroskopischen und histologischen Auswirkungen der intradermalen Injektion von Compound 48/80 wurden bei Hunden untersucht. Dosisabhängige Anstiege in der hautfaltendicke wurden an den Injektionsstellen induziert. Die histopathologische Untersuchung von Hautbioptaten zeigte das Auftreten von Mastzelldegranulation und zellulärer Infiltration. Intradermales Compound 48/80 könnte ein nützliches Modell für Untersuchungen kaniner Hypersensibilitätsprobleme einschließlich der atopischen Dermatitis darstellen. [Mason, I., Lloyd, D. Evaluation of com-pound 48/80 as a skin model of immediate hypersensitivity in the skin of dogs (Die Auswertung von compound 48/80 als Modell für die sofortige hypersensibilität in der haut des hundes). Veterinary Dermatology 1996; 7 : 81–83.]     

Turbulent mixing and mesoscale distributions of late-stage fish larvae on the NW Shelf of Western Australia

Light traps were deployed to describe vertical and cross‐shelf distributions of late‐stage larval fishes during five cruises in each of the 1997/98 and 1998/99 summers in the region of the Gulf of Exmouth on the southern North West Shelf of Western Australia. At each light trap station on a cross‐shelf transect we measured water temperature, salinity and chlorophyll a and used vertical plankton tows to estimate zooplankton biomass and copepod abundance. Current meters were deployed on moorings near the transect and the data used to model flows and mixing on the NW Shelf and in the Gulf. The majority of reef, pelagic and baitfish larvae (81, 83 and 66% respectively) were collected at only two stations that marked the boundary between stratified waters offshore and well‐mixed water within the Gulf. Most baitfishes (primarily Spratelloides spp.) were captured by traps deployed near the seabed, while reef fishes (mostly pomacentrids, lethrinids and siganids) and pelagic species (mostly scombrids and carangids) were captured in traps deployed near surface. Catch composition varied between summers with 64% of baitfishes collected in the first summer, while the majority of reef and pelagic fishes (81 and 80% respectively) were captured in the second summer. Modelling of circulation showed that the velocity of tidal currents was enhanced by constriction of flow between NW Cape and South Muiron Island and by shallowing of the shelf. Flood‐tide intrusions of water allowed the thermocline to move up the continental shelf, upwelling cool nutrient‐rich water that was then mixed throughout the entire water column at stations in the mouth of the Gulf. This upwelling and mixing resulted in higher chlorophyll a concentrations and copepod abundances either as a result of local in situ growth or advection/aggregation processes, and may account for the great abundances of late‐stage fish larvae in the mouth of the Gulf.     

Interrelationships Between Apoptosis and Fertility in Bull Sperm

Male fertility, the ability of sperm to fertilize and activate the egg and support early embryogenesis, is vital for mammalian reproduction. Despite producing adequate numbers of sperm with normal motility and morphology, some males suffer from low fertility whose molecular mechanisms are not known. The objective was to determine apoptosis in sperm from high and low fertility bulls and its relationship with male fertility. DNA damage, phosphatidylserine (PS) translocation, and expression of pro- and anti-apoptotic proteins (BAX and BCL-2) in the sperm were determined using TUNEL, Annexin V, and immunoblotting approaches, respectively. Amounts of apoptotic spermatozoa were 2.86 (± 1.31) and 3.00 (± 0.96) in high and low fertility bulls, respectively (P=0.548), and were not correlated with fertility. There was a negative correlation between early necrotic spermatozoa and viable spermatozoa (r = –0.99, P<0.0001). Fertility scores were correlated with live spermatozoa detected by eosin-nigrosin test and necrotic spermatozoa determined via flow cytometry (r = –0.49, P<0.006 and r = –0.266, P<0.0113, respectively). BAX level was higher in low fertile group than high fertile group; however, this difference was not statistically significant due to the variations of bull samples (Bull 1–3 vs. Bull 4–5) in low fertile group (P<0.283). BCL-2 was not detectable in any of the sperm samples. The results shed light onto molecular and cellular underpinnings of male fertility.