Then, a further knowledge about the kinetic mechanism selleck chemical of melanogenesis is required prior to its possible industrial utilization. In this work, an autocatalytic kinetic model to explain melanin formation from L-tyrosine using mushroom tyrosinase and measuring the absorbance of the solution has been

developed and fitted to experimental data. This expression allows to describe melanin formation as a function of time of reaction, including some important parameters such as the extinction coefficient. Absorbance will start growing after a lag period in which colorless intermediates are produced. The extinction coefficient of the resulting products is not a constant value, because it depends on the conditions of each experiment. Tyrosinase seemed to have a lower catalytic effect on L-tyrosine than on L-DOPA. (C) 2009 Elsevier Ltd. All rights reserved.”
“Toxoplasmosis is a global zoonosis caused by Toxoplasma gondii, an intracellular apicomplexan parasite. The objectives of this study were to estimate EVP4593 chemical structure the animal and flock level seroprevalence and risk factors associated with toxoplasmosis in goats of Central Ethiopia. In Ethiopia, goats are economically important animals used for meat and milk production. The study was cross-sectional

and 927 blood samples from 187 goat flocks were collected to examine T. gondii specific IgG antibodies by enzyme linked immunosorbent assay (ELISA). A questionnaire was used to collect data on the potential risk factors. The study revealed flock and animal level seroprevalence of 58.3% (109/187; 95% confidence interval [CI]:,51.16, 65.42)

and 19.7% (183/927; 95% CI: 17.17, 22.31), respectively. The likelihood of acquiring T. gondii infection was higher in semi-intensively managed goats (Odds ratio [OR] = 2.48, 95% confidence interval [CI]: 1.14, 5.37; P = 0.022) than in extensively managed goats, in females than in males (OR = 1.84, 95% CI: 1.16, 2.92; P = 0.010), in adults than in young animals (OR = 2.00, 95% CI: 1.21, 3.28; P = 0.006), in small than in large flocks (OR = 2.03, 95% CI: 1.03, 3.98; P = 0.040), in goats kept under sedentary (OR = 2.81, 95% CI: 1.41, 5.59; P = 0.003) and agropastoral farming system (OR = 3.62, 95% Nepicastat mw CI: 1.83, 7.18; P < 0.001) than pastoral farming system and in goats allowed to drink water from the tap than those drinking from river and stagnant water bodies (OR = 9.25, 95% CI: 3.04, 28.15; P < 0.001). Our study indicates that exposure of goats to oocysts of T. gondii is widespread. We recommend further studies to determine the genotype of the parasite, public health and economic impacts of toxoplasmosis and the role of raw goat meat and milk as a source of infection for consumers. (C) 2012 Elsevier Ltd. All rights reserved.