RNA complementary to the 5' UTR of mRNA triggers effective silencing in Saccharomyces cerevisiae.

Conditional silencing of target genes in Saccharomyces cerevisiae by antisense RNAs expressed in vivo has been challenged. The MFalpha1::lacZ fusion present in S. cerevisiae SF51-3 was chosen as a model target, and fragments of this gene were cloned in reverse orientation into the expression vector pYES2, bearing the GAL1 promoter. Among the different antisense constructs tested, only the one complementary to the 5' UTR of target mRNA featured effective silencing. Nevertheless, the expression in vivo of this antisense RNA could not be properly tuned by the absence or presence of galactose in the culture medium. Accordingly, conditional silencing could not be attained by this antisense hosted into pYES2. On the contrary, cloning the same antisense construct into the expression vector pSAL4 yielded a fully conditional silencing linked to the control of antisense expression by the absence or presence of Cu(2+) into the culture medium.

Acute hemodynamic effect of nifedipine in hypertensives with chronic renal failure: the influence of volume status.

To study the influence of sodium on the antihypertensive effect of a calcium entry blocker (CEB), 11 hypertensives with chronic renal failure (CRF), whose blood pressure was uncontrolled by hemodialysis, randomly received nifedipine (10 mg p.o.) or the corresponding placebo before and after dialysis, reversing the sequence the next week. Dialysis induced a similar sodium loss during the two experimental periods (-339.0 +/- 26.7 vs. -348.8 +/- 26.4 mEq) and did not significantly change blood pressure. When compared with placebo, nifedipine significantly (p less than 0.05 or less) reduced mean blood pressure and increased heart rate both before and after dialysis, with a peak effect at the first hour. However, both absolute and percentage decrements of mean blood pressure induced by nifedipine before dialysis were significantly (p less than 0.05 or less) greater than those after dialysis. These data indicate that the acute hypotensive effect of nifedipine is greater during sodium repletion than during sodium depletion, a finding that suggests a positive interaction between sodium and the antihypertensive action of CEBs.

[Humoral markers of iron status in patients on maintenance hemodialysis]. / Indici umorali di accumulo di ferro nei pazienti in emodialisi periodica.

In forty-nine patients on regular dialysis treatment (RDT) we evaluated following parameters for a period of twenty-four months: serum ferritin (SF), transferrin, T.I.B.C. percental saturation (Fe/TIBC%), haemoglobin (Hb). Twenty-five patients had received more than 5 g intra-venous iron or several blood transfusions, before the beginning of the study, while the other twenty four patients had never received iron treatment nor transfusions. Serum ferritin and Fe/TIBC% proved to be a good estimate of iron stores in RDT patients. In fact both parameters showed significantly higher levels in iron loaded patients than in never treated patients. Furthermore, in patients who no longer received iron loads during the study period, both SF and Fe/TIBC% showed a significant decrease, without changes in haematologic values. This study demonstrated that oral ferritinic iron (40 mg/day for 6 months) doesn't increase either SF and Fe/TIBC% levels, or modifies haematologic values.

[Acute renal insufficiency caused by diflunisal. Description of a case]. / Insufficienza renale acuta da diflunisal. Descrizione di un caso.

A case of kidney failure in a patient with cirrhosis of the liver in the ascitic stage after treatment of a non-steroid anti-inflammatory drug, diflunisal, is reported. The pathogenesis of the kidney impairment, quickly reversed by withdrawal of the drug, is attributed to pharmacological inhibition of cyclo-oxygenase and prostaglandin synthesis with consequent alterations of intrarenal haemodynamics and renal blood flow.

[Effects of long-term treatment with L-carnitine on dyslipemia in hemodialysis patients]. / Effetti della terapia a lungo termine con L-carnitina sulla dislipemia dei pazienti in emodialisi.

The effect of long-term intravenous administration of L-carnitine on the lipid pattern of 18 patients on intermittent haemodialysis has been evaluated. Serum levels of carnitine were assayed at the beginning and after 4 months of treatment: no significant change was observed. At the end of our investigation, we found a significant reduction of HDL-cholesterol and a significant increase of triglyceride levels, compared with basal values. On the contrary cholesterol levels did not change. Five of the patients though behaved as responders to the treatment: their triglyceride levels decrease while their carnitine values rose significantly. The Authors discuss the therapeutic importance of L-carnitine and its possible influence on dyslipaemia of uremic haemodialysed patients.

[Nephrotoxicity of contrast media for urography in patients with chronic renal insufficiency]. / Nefrotossicità dei mezzi di contrasto per urografia in pazienti con insufficienza renale cronica.

The incidence of nephrotoxicity caused by intravenous pielography (IVP) contrast media was retrospectively evaluated in 42 patients with chronic renal failure. In 14 patients renal function was acutely impaired after IVP. In most cases the dysfunction was only temporary; in 3 cases permanent damage was induced, one of which required dialytic treatment. In the cases described there appears to be no correlation between the degree of renal failure and the incidence of nephrotoxicity but the former is clearly linked to the severity of the nephrotoxic response.