192 research outputs found
Characteristics and importance of the genus Prototheca in human and veterinary medicine
Prototheca spp. are strange algae, assigned to the genus Prototheca, family Chlorelaceae. They are ubiquitous in nature, living predominantly in aqueous locales containing decomposing plant material. Prototheca spp. were isolated from skin scarificates, sputum and feces of humans in absence of infection as well as in a variety of domestic and some wild animals. Prototheca spp. are unicellular organisms, oval or spheric in shape. They differ from bacteria and fungi in size, shape and reproductive characteristics. Of the five known species of the genus, only P. wickerhamii and P. zopfii are considered pathogenic, and they are the only known plant causative agents of human and animal infections. Over the past 25 years medical references reported more than 100 cases of human protothecoses, mostly induced by P. wickerhamii and rarely by P. zopfii. A half of the reports on human protothecoses relates to localized cutaneous infections and oleocranon bursitis. The rarest and most severe form of the infection is disseminated or systemic protothecosis, described in patients with durable course of primary disease or immune disfunction. In veterinary medicine, Prototheca zopfii and rarely also P. wickerhamii are reported as causative agents of cutaneous protothecosis in dogs and cats, systemic protothecosis in dogs and mastitis in dairy cows. Protothecal infections are diagnosed by histopathology examination or, more exactly, by isolation of the agent, although the organism cannot be distinguished from the yeasts by its cultural characteristics. Final diagnosis is made by the carbon-hydrate assimilation test. Protothecal infections are easily missed in routine practice. Pharmacological protocol for therapy of this rare infection has not been developed yet either in human or in veterinary medicine. Several antifungal agents are applied for treatment; however, the effects are variable. Where possible, surgical excision is treatment of choice. Prognosis is promising in patients with localized infection, and healing is often achieved. Prognosis is less predictable, mostly bad, in patients with other diseases and in immunocompromized patients. Sensitivity of Prototheca spp. in vitro does not necessarily correlate with its efficacy in vivo
Comparative investigations of immune response of calves at different intervals between primary and secondary immunization using inactivated bovine herpes virus 1 vaccine
Bovine herpesvirus 1 (BHV-1) is one of the most siginificant causes of
infections of the respiratory tract of cattle and immunoprophylaxis has a key
role in curbing this infection. The intensity of the immune response against
BHV-1 following immunization using inactivated commercial vaccines varies
depending on the type of vaccine, but it is generally believed that they
provide good protection from the development of the clinical form of the
infection, and that they are safe. The paper present the development of the
humoral immune response in fattening calves that were immunized against
bovine herpesvirus 1 (BHV-1) at different time intervals between the primary
and the secondary immunization. Calves were administered a commercial
vaccine, and then they were divided into two groups which were revaccinated
on days 14 or 21. Over a course of the 120 days of the duration of the
experiment, blood and nasal mucus were sampled 11 times. The blood serum
samples were examined for antibodies to BHV-1 using the virus neutralization
(VN) test, and the nasal mucus samples were analyzed using the VN test and
the ELISA method. Following revaccination, it was established that there was
an increase in the antibody titer in blood of all experimental animals, and
it was maintained at a high level up until the very end of the experiment
(day 120). In the blood serums, maximum mean values for the antibody titer
were determined on day 30 in the group that was revaccinated on day 14, and
on day 45 in the group of calves revaccinated on day 21. In nasal mucus,
antibodies were established at the earliest, using the virus neutralization
test, on day 14 following vaccination, and using the ELISA method only after
revaccination. The highest antibody titer in nasal mucus was established on
day 45 in the group revaccinated on day 21, and on day 120 in the group
revaccinated on day 14. Based on the established antibody titer values,
calves can be revaccinated using the inactivated BHV-1 vaccine already on day
14. [Projekat Ministarstva nauke Republike Srbije, br. 31084
Seiberg-Witten Theory and Extended Toda Hierarchy
The quasiclassical solution to the extended Toda chain hierarchy,
corresponding to the deformation of the simplest Seiberg-Witten theory by all
descendants of the dual topological string model, is constructed explicitly in
terms of the complex curve and generating differential. The first derivatives
of prepotential or quasiclassical tau-function over the extra times, extending
the Toda chain, are expressed through the multiple integrals of the
Seiberg-Witten one-form. We derive the corresponding quasiclassical Virasoro
constraints, discuss the functional formulation of the problem and propose
generalization of the extended Toda hierarchy to the nonabelian theory.Comment: 32 pages, LaTe
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