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Infection Spread (infection + spread)
Selected AbstractsPathological and epidemiological observations on rickettsiosis in cultured sea bass (Dicentrarchus labrax L.) from GreeceJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2004F. Athanassopoulou Summary A systemic infection of a Rickettsia -like organism (RLO) in cultured sea bass is described for the first time. In hatcheries, clinical signs were lethargy, inappetence and discoloration. Twenty days after transfer to sea cages from hatcheries where the disease existed, fish showed erratic and abnormal swimming behaviour, loss of orientation, and lethargy. Cumulative mortality in colder months of the year reached 30% in hatcheries and 80% in cages. Surviving fish in cages did not show any clinical signs of RLO infection in the subsequent year. Evidence for a systemic distribution of RLO was supported by histolopathological lesions in both infected hatchery and caged fish, where the lesion profile included cranial sensory, central nervous, integumental and alimentary organ systems. Intracranial lesions were primarily characterized by an ascending histiocytic perineuritis and necrotizing congestive meningoencephalitis, with evidence for transfer of infective agents across the blood,brain barrier confirmed by the presence of RLOs within capillary endothelium and histiocytes in inflamed regions of the optic tectum and the cerebellum. In the most severe cases, infection spread to the statoacoustical (semicircular) canal system and the ependymal lining of ventricles, with marked rickettsial-laden histiocytic infiltration of the canal lumen. Integumental lesions were restricted to the oral submucosa, nares and integumental dermis of the cranium. Alimentary lesions were noted in both the liver parenchyma and mucosa/submucosa of the stomach. In all affected organs the RLOs were found by immunohistochemistry to be related to Piscirickettsia salmonis. [source] Mediastinal node and diaphragmatic targeting after intracavitary injection of avidin/99mTc-blue-biotin-liposome systemJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 1 2006Luis A. Medina Abstract A method for delivering drugs to sites of disease extension in mediastinal nodes is described. Mediastinal node and lymphatic distributions were determined after intracavitary injection of the avidin/biotin-liposome system in normal rats. The effect of the injected dose on lymphatic targeting of liposomes after intraperitoneal injection of 99mTc-blue-biotin-liposomes and intrapleural injection of avidin, and vice versa, is presented. Scintigraphic imaging was used to follow the movement of 99mTc-blue-biotin-liposomes to determine the pharmacokinetics and organ uptake. Tissue biodistribution studies were performed 22 h after injection of the 99mTc-blue-biotin-liposomes. Results indicated that independent of the cavity in which each agent was injected, a dose of 5.0 mg of each agent results in higher mediastinal node targeting (8%,10% ID/Organ) as compared with the injection of a 0.5 mg dose (2%,5% ID/Organ, p,<,0.05). Targeting of diaphragm and associated lymphatics was observed when 99mTc-blue-biotin-liposomes were injected in peritoneum and avidin in pleural space. In contrast, pleural, and pericardial lymphatic targeting was observed when 99mTc-blue-biotin-liposomes were injected in pleural space and avidin in peritoneum. Intracavitary injection of the avidin/biotin-liposome system could potentially be used for the delivery of prophylactic drugs that could reduce tumor metastasis and infection spread to mediastinal nodes. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95:207,224, 2006 [source] Cryptococcosis in ferrets: a diverse spectrum of clinical diseaseAUSTRALIAN VETERINARY JOURNAL, Issue 12 2002R MALIK Cryptococcosis was diagnosed in seven ferrets (five from Australia; two from western Canada) displaying a wide range of clinical signs. Two of the ferrets lived together. One (5-years-old) had cryptococcal rhinitis and presented when the infection spread to the nasal bridge. Its sibling developed cryptococcal abscessation of the right retropharyngeal lymph node 12 months later, soon after developing a severe skin condition. DNA fingerprinting and microsatellite analysis demonstrated that the two strains isolated from these siblings were indistinguishable. Two ferrets (2- to 3-years-old) developed generalised cryptococcosis: one had primary lower respiratory tract disease with pneumonia, pleurisy and medi-astinal lymph node involvement, while in the other a segment of intestine was the primary focus of infection with subsequent spread to mesenteric lymph nodes, liver and lung. The remaining three ferrets (1.75 to 4-years-old) had localised disease of a distal limb, in one case with spread to the regional lymph node. Cryptococcus bacillisporus(formerly C neoformansvar gattii) accounted for three of the four infections in Australian ferrets where the biotype could be determined. The Australian ferret with intestinal involvement and the two ferrets from Vancouver had C neoformansvar grubiiinfections. [source] Quantifying Viral Propagation in Vitro: Toward a Method for Characterization of Complex PhenotypesBIOTECHNOLOGY PROGRESS, Issue 6 2001Karen A. Duca For a eukaryotic virus to successfully infect and propagate in cultured cells several events must occur: the virion must identify and bind to its cellular receptor, become internalized, uncoat, synthesize viral proteins, replicate its genome, assemble progeny virions, and exit the host cell. While these events are taking place, intrinsic host defenses activate in order to defeat the virus, e.g., activation of the interferon system, induction of apoptosis, and attempted elicitation of immune responses via chemokine and cytokine production. As a first step in developing an imaging methodology to facilitate direct observation of such complex host/virus dynamics, we have designed an immunofluorescence-based system that extends the traditional plaque assay, permitting simultaneous quantification of the rate of viral spread, as indicated by the presence of a labeled viral protein, and cell death in vitro, as indicated by cell loss. We propose that our propagation and cell death profiles serve as phenotypic read-outs, complementing genetic analysis of viral strains. As our virus/host system we used vesicular stomatitis virus (VSV) propagating in hamster kidney epithelial (BHK-21) and murine astrocytoma (DBT) cell lines. Viral propagation and death profiles were strikingly different in these two cell lines, displaying both very different initial titer and cell age effects. The rate of viral spread and cell death tracked reliably in both cell lines. In BHK-21 cells, the rate of viral propagation, as well as maximal spread, was relatively insensitive to initial titer and was roughly linear over several days. In contrast, viral plaque expansion in DBT cells was contained early in the infections with high titers, while low titer infections spread in a manner similar to the BHK-21 cells. The effect of cell age on infection spread was negligible in BHK-21 cells but not in DBTs. Neither of these effects was clearly observed by plaque assay. [source] Non-invasive imaging of mouse hepatitis coronavirus infection reveals determinants of viral replication and spread in vivoCELLULAR MICROBIOLOGY, Issue 5 2009Matthijs Raaben Summary Bioluminescence imaging (BLI) is a powerful new method to study virus dissemination in the live animal. Here we used this method to monitor the spatial and temporal progression of mouse hepatitis coronavirus (MHV) infection in mice using luciferase-expressing viruses. Upon intranasal inoculation, virus replication could initially be observed in the nasal cavity and the cervical lymph nodes, after which the infection spread to the brain and frequently to the eyes. The kinetics of virus spread to and clearance from the brain appeared to depend on the inoculation dose. After intraperitoneal inoculation, virus replication was predominantly observed in the liver and occasionally in the intestines, but interestingly also in the tail and paws. BLI thus elucidated new anatomic locations of virus replication. Furthermore, MHV dissemination was shown to be critically depended on the viral spike protein, but also on the mouse strain used. Widespread dissemination was observed in mice lacking a functional type I interferon response. The importance of the type I interferon system in limiting viral spread was also demonstrated by the administration of type I interferons to mice. Our results provide new insights in coronavirus pathogenesis and demonstrate the potential of BLI to study coronavirus,host interactions in vivo. [source] | ||||||||||