Supplementation with L-arginine affects its metabolizing pathways in rat liver subjected to bile duct ligation.

Liver cholestasis is known to accompany several major liver disorders and is adequately mimicked in rats by ligation of the bile duct (BDL). L-arginine is a semi-essential amino acid which is involved in several important metabolic pathways that are significantly affected during cholestasis. This study was conducted in order to contribute to the understanding of the enrolment of L-arginine supplementation in cholestatic liver function. This was carried out by estimation of serum and liver tissue arginase activity, along with liver tissue citrulline, nitric oxide (NO) and polyamine concentrations. Rats subjected to BDL were treated for nine days with L-arginine (150 mg/kg) or remained without any treatment. Animals from two control groups were either subjected to medial laparotomy (sham/opened group) or were without any surgical treatment and received only L-arginine. Application of L-arginine prevented a significant increase in plasma bile acid and bilirubin concentrations, as well as enzyme biochemical markers that were increased after BDL. It is worth mentioning that L-arginine was able to cause a decrease in arginase activity and liver tissue NO concentrations that were found to be significantly altered during cholestasis. On the other hand, the changes occurring in the concentration of liver polyamines (putrescine, spermidine and spermine) and the activity of polyamine metabolizing enzymes were not notably affected by the administered L-arginine. The results of the present study revealed that exogenous L-arginine was able to ameliorate or prevent changes occurring in its metabolism in liver during cholestasis.

[Micronuclei and ageing in a sample of Yugoslavian population]. / Microiadra i starenie. Issledovanie na vyborke zhitelei Iugoslavii.

OBJECTIVE: Instability in the organization and expression of the genetic material has been hypothesized as the basic mechanism of ageing. Aim of this study was to quantify the effect of ageing on spontaneous micronuclei (MN) frequency in peripheral blood lymphocytes. METHOD: Analysis of Yugoslavian population sample (164 tested individuals, age 0-62 years) has performed by application of cytokinesis-block technique (CB). RESULTS: There was an increase of MN frequency with age, from newborns to 40-year-old persons. The total average of MN frequency per 1000 analyzed binuclear cells amounts to 8.03 +/- 0.42, with variation from 0 to 26 MNs. In a sample of 29 newborns the recorded average MN frequency was 6.91 +/- 0.81, while among 69 persons 25-39 years old, the MN frequency was 9.16 +/- 1.00. The lowest average MN frequency, however, was noted in the sample of 34 tested individuals 40 to 62 years of age. CONCLUSION: An increase with age in MN frequency has been observed in samples of studied individuals from newborns to 40-year-old persons. A decrease of MN frequency in older groups could be explained by a gradual decrease of proliferative cell capacities.

Disengagement of attention in schizophrenia.

We compared covert shift of visual attention in patients with schizophrenia or bipolar disorder, both in states of remission, to normal controls to examine the persistence of lateralized attentional deficits into nonpsychotic states. Although patients were slower in all conditions than normals, there was no difference in pattern of attentional shift among the groups. This suggests that the left-hemisphere deficit in shift of covert attention in schizophrenia may be limited to periods of florid illness.

[The monitoring of air pollution in a hospital environment using quantitative air biology methods]. / Kontrola oneciscenja zraka bolnicke sredine kvantitativnim aerobioloskim metodama.

The methodology of quantitative aerobiological control is described and the results of measurements of the intensity and character of air contamination are commented for several places of general surgical ward. The importance of such a control is stressed in the context of general efforts to improve the quality of air in hospitals, to prevent air contamination and decrease the incidence of aerogenic infections. The results of those measurements show that the intensity of air contamination is corresponding to the total volume of physical activity in a milieu. In some very delicate hospital areas (dressing units and operating theatres), the concentration of aerosol sometimes exceeds its permitted level and if this is a case, it is advised to take all possible measures of protection to prevent air contamination and aerogenic infections. It is also found out that at the very beginning of physical activity, there is predominance of relatively big aerosol fractions in air, but soon this predominance is diminished because of the elimination of those fractions by sedimentation.