The Morphology of the Ureter in the Duck (Anas platyrhynchos)

The morphology of the ureter of the duck was investigated, using histological, SEM and TEM techniques. The inner perimeter, the total thickness of the ureteral wall and the thickness of each uretral layer were measured. The epithelium was tall columnar and pseudostratified along all the tracts of the ureter and showed a high muco-secretive activity. The lamina propria contained numerous capillaries and aggregates of leucocytes and macrophages. Throughout the lamina propria there was a dense plexus of nerves. Some denuded single nerve fibres were observed between the epithelial basal cells. A plexus of nerves was also observed in the tunica muscularis. The ostium cloacale ureteris opened on a well-developed papilla in the dorsal region of the urodeum. The total thickness of the ureteral wall, the thickness of the lamina propria and the tunica muscularis, and the inner perimeter progressively increased towards the ostium. The above observations suggest that the avian ureter plays an important role in the modification of the urine coming from medullary cones, and in emission of the urine into the cloaca.     

Salmon cells SHK‐1 internalize infectious pancreatic necrosis virus by macropinocytosis

We have previously shown that infectious pancreatic necrosis virus (IPNV) enters the embryo cell line CHSE‐214 by macropinocytosis. In this study, we have extended our investigation into SHK‐1 cells, a macrophage‐like cell line derived from the head kidney of Atlantic salmon, the most economically important host of IPNV. We show that IPNV infection stimulated fluid uptake in SHK‐1 cells above the constitutive macropinocytosis level. In addition, upon infection of SHK‐1 cells, IPNV produced several changes in actin dynamics, such as protrusions and ruffles, which are important features of macropinocytosis. We also observed that the Na+/H+ pump inhibitor EIPA blocked IPNV infection. On the other hand, IPNV entry was independent of clathrin, a possibility that could not be ruled out in CHSE 214 cells. In order to determine the possible role of accessory factors on the macropinocytic process, we tested several inhibitors that affect components of transduction pathways. While pharmacological intervention of PKI3, PAK‐1 and Rac1 did not affect IPNV infection, inhibition of Ras and Rho GTPases as well as Cdc42 resulted in a partial decrease in IPNV infection. Further studies will be required to determine the signalling pathway involved in the macropinocytosis‐mediated entry of IPNV into its target cells.     

Chemical composition of essential oils in Mentha spicata L. accession [IIIM(J)26] from North-West Himalayan region,India

Mentha spicata L. (spearmint) was collected from different sub-tropical and temperate zones of North-West Himalayan region of India. Plants were collected during the flowering stage and essential oil was extracted using Clevenger-type apparatus for 2.5 h and analyzed. GC–MS analysis reveals that carvone was major part which varied between 49.62%–76.65%, second major component was limonene that varied between 9.57%–22.31%. 1,8-cineole varied between 1.32%–2.62%, whereas trans-carveol varied between 0.3%–1.52%. Out of 26 collections, one accession was found rich in carvone (76.65%) along with low limonene content (9.57%). Chemical composition of this accession is described in detail.     

Cyclic variation and solar forcing of Holocene climate in the Alaskan subarctic

High-resolution analyses of lake sediment from southwestern Alaska reveal cyclic variations in climate and ecosystems during the Holocene. These variations occurred with periodicities similar to those of solar activity and appear to be coherent with time series of the cosmogenic nuclides 14C and 10Be as well as North Atlantic drift ice. Our results imply that small variations in solar irradiance induced pronounced cyclic changes in northern high-latitude environments. They also provide evidence that centennial-scale shifts in the Holocene climate were similar between the subpolar regions of the North Atlantic and North Pacific, possibly because of Sun-ocean-climate linkages.     

Morphological changes,peptidase activity,and effects of exogenous enzymes in the early ontogeny of Nile tilapia,Oreochromis niloticus

Aquaculture International - During the early ontogeny, the transition from endogenous (yolk protein) to exogenous feeding (artificial diets) represents a critical period linked to the...     

Simple assay for analyzing five microcystins and nodularin in fish muscle tissue: hot water extraction followed by liquid chromatography-tandem mass spectrometry

A simple, specific, and sensitive procedure for determining six cyanotoxins, that is, microcystins RR, LR, YR, LA, and LW and nodularin, in fish muscle tissue is presented. This method is based on the matrix solid-phase dispersion technique with heated water as extractant followed by liquid chromatography (LC)-tandem mass spectrometry (MS) equipped with an electrospray ion source. Target compounds were extracted from tissue by 4 mL of water acidified to pH 2 and heated at 80 degrees C. After acidification and filtration, 0.2 mL of the aqueous extract was injected in the LC column. MS data acquisition was performed in the multireaction monitoring mode, with at least two precursor ion > product ion transitions selected for each target compound. Analyte recovery ranged between 61 and 82% and was not substantially affected by either the analyte concentrations or the type of fish. The nonexcellent recovery of some of the microcystins was traced to binding of these compounds to protein phosphatases in fish tissue occurring during sample treatment. The existence of covalently bound microcystins in fish has been evidenced by several studies. Compared to an older sample preparation procedure, this one extracted larger amounts of the analytes in a simpler and much more rapid way. On the basis of a signal-to-noise ratio of 10, limits of quantification were estimated to range between 1.6 and 4.0 ng/g. The effects of temperature and volume of the extractant on the analyte recovery were studied.     

Sur la Microvascularisation des Plexus Choroïdes des Ventricules Latéraux chez la Chèvre (Capra hircus)

The goat choroid plexus angioarchitecture of the lateral ventricles was studied under the SEM using the method of “microvascular corrosion casts”. The whole plexus is semilunar shaped and directed in an antero-posterior, latero-median fashion. In the plexus the lateral extremity is larger than the median one. All the components of the vascular bed (arteries, venes and capillaries) of the choroid plexus have interesting morpho-structural features. In particular, the capillaries are more developed than the other components and they are variously located on both sides of the plexus. The capillary network has a various organization in different zones of each side of the plexus.