Deprivation of dietary nucleotides decreases protein synthesis in the liver and small intestine in rats

BACKGROUND & AIMS: Dietary nucleotides are reported to influence the growth and functioning of the liver and small intestine. The aim of this study was to examine the mechanism by which nucleotides exert their effects in these tissues by assessing protein synthesis activity and related parameters in the presence or absence of dietary nucleotides. METHODS: Rats were fed a purified diet with or without nucleotides for 10 days. Fractional protein synthesis rate, RNA and DNA concentrations, polysome size distribution, and number of ribosomes were assessed. RESULTS: Fractional protein synthesis rates of the liver and small intestine were lower in the nucleotide-deprived group than in the control group. In the liver, RNA concentration was also lower in the nucleotide-deprived group, but values in the small intestine were similar in the two groups. In the liver, deprivation of nucleotides resulted in a reduction in the number of ribosomes and in polysome breakdown. Protein and DNA concentrations did not vary in the liver; however, the concentration of DNA was lower in the small intestine of the nucleotide-deprived group than in the control group. CONCLUSIONS: Dietary nucleotides can modulate protein synthesis in the liver and small intestine as a result of tissue-specific nucleic acid changes. (Gastroenterology 1996 Jun;110(6):1760-9)     

Comparison of weekly and daily incremental protocols of narrowband ultraviolet B phototherapy for psoriasis

BACKGROUND: Different protocols have been used for narrowband ultraviolet B (UVB) therapy, commonly used in the treatment of psoriasis; however, more effective and reliable protocols are still required. OBJECTIVE: The aim of this study was to compare the weekly and daily dose increment protocols of narrowband UVB phototherapy in psoriasis patients. METHODS: Thirty patients with plaque psoriasis underwent narrowband UVB treatment three times a week and 15 patients selected consecutively among these patients underwent a weekly (once in three treatments) dose increment whereas the remaining 15 patients underwent a daily dose increment. Patients were monitored for 10 weeks and evaluated by the Psoriasis Area Severity Index (PASI). RESULTS: When the two groups were evaluated according to median PASI scores prior to the treatment and during 10 weeks of treatment, there was no statistically significant difference between the groups (P > 0.05). During the treatment lasting for 10 weeks, four patients in the group with a weekly dose increment and three patients in the group with a daily dose increment recovered and no statistically significant difference was detected between the groups (P > 0.05). The groups were also evaluated according to the median cumulative dose. The median cumulative dose was higher in the group with a daily dose increment and the difference between the groups was statistically significant (P = 0.002). CONCLUSION: The application of daily dose increments was no better than that of weekly dose increments in narrowband UVB treatment for psoriasis. Therefore, although our results may need to be supported by large-series studies, we conclude that application of weekly dose increments with a lower cumulative dose having the same efficacy is preferred in narrowband UVB treatment of psoriasis.     

Percutaneous extraction of urinary calculi: use of the intercostal approach

The authors achieved successful percutaneous extraction of urinary calculi via an intercostal approach in 24 patients. In one patient, a large hydrothorax developed and thoracentesis was required; 2 patients had moderate and 6 minimal pleural fluid collections which did not require treatment. No patient had pneumothorax. Intercostal puncture provides direct access to the upper and middle poles of the kidney when they lie above the twelfth rib and subcostal angulation is not feasible. Such an approach is advantageous for stones in the ureter, as well as renal stones which are inaccessible from the lower pole. Fluoroscopy should be performed when planning the puncture in order to avoid the lung, and a working sheath is recommended.