Induction of signal transduction pathways related to the pathogenicity of Cryptococcus neoformans in the host environment

Cryptococcus neoformans, a human pathogenic fungus, infects immunocompromised humans and causes serious diseases such as cerebral meningitis. C. neoformans controls the expression of virulence factors in response to the host environment via various signal transduction pathways. Understanding the molecular mechanisms involved in C. neoformans infection will contribute to the development of methods to prevent and treat C. neoformans-related diseases. C. neoformans produces virulence factors, such as a polysaccharide capsule and melanin, to escape host immunity. Several proteins of C. neoformans are reported to regulate production of the virulence factors. In this review, on the basis of studies using gene-deficient mutants of C. neoformans and animal infection models, we outline the signal transduction pathways involved in the regulation of virulence factors.

Molecular Detection of Anaplasma Phagocytophilum as a Zoonotic Agent in Owned and Stray Dogs in Tehran, Iran

The genus Anaplasma is an obligated intracellular Rickettsia and among its species, Anaplasma phagocytophilum (A. phagocytophilum) is a zoonotic agent that infects host neutrophils. The aim of this study was molecular detection of A. phagocytophilum infection based on MSP4 gene in owned and stray dogs in Tehran, capital of Iran. One hundred and fifty blood samples were collected from dogs in Tehran and suburbs of Tehran, Iran. Firstly, the thin blood smears were prepared and Giemsa staining method was conducted. Then, the samples were examined under oil immersion objective and 0.67% of them were observed infected with A. phagocytophilum. The DNA was extracted from blood samples using a DNA isolation kit (MBST, Iran), and MSP4 gene extraction was performed by Polymerase chain reaction (PCR) and nested-PCR. Finally, 2% of the samples were positive for A. phagocytophilum. The data were analyzed using SPSS software (version 19.0) and Chi-square test was performed. There was no significant relation between infection and age, as well as sex and ectoparasitic infestation (P>0.05). This article was a report of A. phagocytophilum infection in dogs and their potentials as host carriers of this important microorganism in Tehran, Iran.

Effect of protein intake on mineral (calcium, magnesium, and phosphorus) balance in Japanese males

A 26-day balance study was conducted to examine the effect of a high protein diet on calcium, magnesium, and phosphorus utilization in six healthy males (age 20-22 years, body weight 54.0-64.4 kg, body height 165-173 cm). In addition, the effect of physical exercise on calcium, magnesium, and phosphorus balance was also examined. After a 2-day stabilization period, two levels of protein--control (1.0 g/kg of body weight) and high (2.0 g/kg of body weight) protein--diets were given for three 4-day periods at each protein level. During the last 4-day period of each protein level, subjects exercised on a bicycle ergometer for two 1-h periods daily at a load of 1.5 kp., 50 cyc./min. The high protein diet increased urinary calcium and caused a significant negative calcium balance. Magnesium balance tended to be negative in the control diet. There were no significant changes in urinary calcium, magnesium, and phosphorus and also in the calcium, magnesium, and phosphorus balance during physical exercise.