Immunohistochemical analysis of constituents of senile plaques and cerebro-vascular amyloid in aged dogs.

Immunohistochemical analysis of constituents of senile plaques and cerebro-vascular amyloid in the brain of aged dogs was performed using antisera against beta protein, cystatin C, ubiquitin, tau, and neurofilament (NF). All types of senile plaques and cerebro-vascular amyloid in aged dogs were labeled by anti-beta protein serum. Cystatin C immunoreactivity was detected in neuronal cell bodies, primitive or classical plaques, and amyloid deposited around cerebral capillaries, but not in diffuse plaques and amyloid deposited in the media tunica of cerebro-meningeal arterioles. Ubiquitin-positive granules distributed widely in both gray and white matter of aged dogs, while they were very small in number in young dogs. Swollen neurites-like materials in primitive plaques or classical plaques were immunoreactive for anti-ubiquitin serum. Tau immunostaining labeled commonly axons and several neuronal or glial cells after hydrate autoclave pretreatment. Tau-positive components were observed very rarely in the corona of classical plaques. Most of swollen neurites-like structures of primitive or classical plaques were not reactive for anti-NF serum, and only a few plaques contained small numbers of NF-positive elements.     

Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography

Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomorphic macromolecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses.     

The effect of pretreatment with different doses of GnRH to synchronize follicular wave on superstimulation of follicular growth in dairy cattle

The objective of this study was to evaluate the efficiency of gonadotropin releasing hormone (GnRH) and GnRH doses in synchronizing follicular wave emergence as a pretreatment for superovulation in cattle. Fourteen Holstein-Friesian cows 6 days from estrus were randomly assigned to receive 100 microg (n=4), 50 microg (n=5), or 25 microg (n=5) of GnRH. Superovulation was induced with injections of porcine FSH (pFSH) twice daily, decreasing the dose (total 42 AU) over 5 days beginning 2.5 days after receiving GnRH. On the 7th and 8th injections of pFSH, 750 microg of PGF(2alpha) was also given. With the exception of one cow that was given 50 microg of GnRH, ovulation was induced in all cows from the three groups and the new follicular wave emergence was observed. The total number of follicles for the 25 microg GnRH group was less than that observed for the 100 microg GnRH group (P<0.05), although there were no differences between the 100 microg, 50 microg and 25 microg GnRH groups with respect to the number of preovulatory follicles (>or=10 mm) and CL. The numbers of normal embryos were greater for the 25 microg GnRH group than the 100 or 50 microg GnRH groups (P<0.01); however, the numbers of ova/embryos did not differ significantly between the three groups. These results suggest that 25 microg of GnRH was sufficient to induce ovulation and follicular wave emergence. On day 6 of the estrous cycle, a reduction of the dose of GnRH to synchronize follicular wave emergence as a pretreatment for superstimulation promotes transferable embryos.     

Physico-chemical properties of calf-diarrhea coronavirus

Replication of calf diarrhea coronavirus was not inhibited by 5-iodo-2′-deoxyuridine, indicating that the virus is an RNA virus. Sensitivity to ether and chloroform indicated that the virus is enveloped, and this was confirmed by electron microscopic observation of the virion. The virus was readily inactivated by trypsin and sodium deoxycholate. The virus was labile at 50°C in diluted medium, but readily stabilized in the presence of MgCl₂. It was stable at pH 5 and 7, while a slight loss of infectivity was observed at pH 3. The virus was readily filtered through membrane filters of 200 and 100-nm pore sizes, but not through 50-nm filters. The buoyant density of the virion in CsCl was estimated to be 1.25 g/ml.