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Prevalence of subclinical coccidiosis in river buffalo calves of Southwest of Iran

100%

Bahrami S. , Alborzi A. R.

nr 4

Despite the importance of buffalo farming in Iran, little is known in this country about the abundance and distribution of Eimeria spp. in the animal species. The present study was designed to investigate the prevalence and species characterization of Eimeria oocysts in river buffalo calves of Khuzestan province, southwest of Iran. Of the total 108 fecal samples examined for Eimeria, 108 (100%) were found infected with 11 species of the parasite. Among the identified species of Eimeria, E. bovis was found to be the predominant etiological agent (76.85%), followed in order by E. canadensis (62.96%), E. zuernii (47.2%), E. ellipsoidalis (26.85%), E. subspherica (25.92%), E. brasiliensis (19.4%), E. auburnensis (18.51%), E. alabamensis (14.81%), E. pellita (11.1%), E. illinoisensis (5.5%) and E. bukidnonensis (2.7%). In most calves multiple infections with three species were present. While, 20.7% of calves showed heavy infection, 50.4 and 24.8% of calves showed weak and moderate infection, respectively. There was no significant difference in the OPG values between the calves of different localities. There was also no significant difference between the prevalence rate of infection in males and females. A total of 16.6% of all faecal samples were found to be diarrheic. A highly significant relationship could be identified between the occurrence of diarrhea and the level of E. bovis and E. zuernii oocysts excretion. Considering the pervasive occurrence and negative effects of the infection on the health condition and the growth performance of buffalo calves, infections should receive increased attention by both farmers and veterinarians.

Mitochondria recycle nitrite back to the bioregulator nitric monoxide

61%

Nohl H. , Staniek K. , Sobhian B. , Bahrami S. , Redl H. , Kozlov A. V.

2000

tom 47

nr 4

Nitric monoxide (NO) exerts a great variety of physiological functions. L-Arginine supplies amino groups which are transformed to NO in various NO-synthase-active isoenzyme complexes. NO-synthesis is stimulated under various conditions increasing the tissue of stable NO-metabolites. The major oxidation product found is nitrite. Elevated nitrite levels were reported to exist in a variety of diseases including HIV, reperfusion injury and hypovolemic shock. Denitrifying bacteria such as Paracoccus denitrificans have a membrane bound set of cytochromes (cyt cd1, cyt bc) which were shown to be involved in nitrite reduction activities. Mammalian mitochondria have similar cytochromes which form part of the respiratory chain. Like in bacteria quinols are used as reductants of these types of cytochromes. The observation of one-e- divergence from this redox-couple to external dioxygen made us to study whether this site of the respiratory chain may also recycle nitrite back to its bioactive form NO. Thus, the aim of the present study was therefore to confirm the existence of a reductive pathway which reestablishes the existence of the bioregulator NO from its main metabolite NO2-. Our results show that respiring mitochondria readily reduce added nitrite to NO which was made visible by nitrosylation of deoxyhemoglobin. The adduct gives characteristic triplet-ESR-signals. Using inhibitors of the respiratory chain for chemical sequestration of respiratory segments we were able to identify the site where nitrite is reduced. The results confirm the ubiquinone/cyt bc1 couple as the reductant site where nitrite is recycled. The high affinity of NO to the heme-iron of cytochrome oxidase will result in an impairment of mitochondrial energy-production. "Nitrite tolerance" of angina pectoris patients using NO-donors may be explained in that way.