Modification of serum and membrane lipid composition induced by diet in patients with chronic renal failure

Disorders of lipid metabolism during chronic renal failure (CRF) play a crucial role in the pathogenesis of early cardiovascular complication of this syndrome. In addition, some experimental evidence suggests that hyperlipidemia may accelerate progression of renal disease. We have studied 65 patients with CRF (S-creatinine 1.5-9.0 mg/dl), 52.3% of whom were hypertensive. Patients were divided in 2 groups matched for age, sex and degree of renal failure: group 1 was kept for 36 +/- 8 months on a free diet; group 2 was kept for 39 +/- 6 months on a low-protein diet with an elevated polyunsaturated/saturated fatty acid (PUFA/SFA) ratio. We found significantly higher levels of triglycerides (TG) and lower levels of esterified cholesterol in high density lipoprotein (HDL-C) in group 1 than in group 2. Patients on the diet had a lower percentage of membrane SFA and a higher percentage of PUFA than patients on free diet. Only in group 1 a direct correlation between cholesterol/phospholipid (Chol/P) ratio and age was observed; in group 2, a negative correlation between levels of PUFA and TG and between linoleic/oleic (Lin/Ol) ratio and serum Chol was shown. S-creatinine levels were directly correlated with Chol/P ratio in group 1 and indirectly with Lin/Ol ratio and PUFA in group 2. These data show that a low-protein diet, containing an elevated PUFA/SFA ratio, is able to counteract lipid abnormalities in patients with CRF and the normalization of this pattern is associated with significant improvement of membrane lipid composition and, presumably, of "functional" activity of cell membranes with a better control of supposed "renal lipoprotein toxicity".     

Atrial natriuretic factor and autonomic nervous system function in man

Summary To delineate a possible interaction of atrial natriuretic peptide ANF-(99–126) with autonomic nervous system function in humans, a spectrum of indices were assessed in 10 healthy young men during a 90 min iv administration of a) synthetic ANF-(99–126) 50 g bolus followed by 0.025 g·kg^–1·min^–1, b) the potent vasodilator sodium nitroprusside (SNP) 0.35 g·kg^–1·min^–1, or c) vehicle 0.9% NaCl 40 ml and 20% albumin 5 ml, in random sequence.Plasma immunoreactive ANF (irANF) rose from 32 to 1700 pg·ml^–1 during the ANF-(99–126) infusion and was stable during SNP or vehicle. Infusion of ANF-(99–126) and SNP, but not vehicle, decreased diastolic blood pressure (BP) on average by –9 and –7.5%, respectively; systolic BP was largely unchanged. Heart rate (HR, +15 and 12%) or plasma norepinephrine (NE) rose similarly during ANF-(99–126) and SNP infusions, and the systolic BP response to orthostasis was similar (–18 mm Hg). The following autonomic indices did not differ significantly after the 3 infusions: responses of HR and NE to orthrostasis; reflex bradycardic response to phenylephrine (PE)-induced rise in systolic BP (+20 mm Hg); responses of BP to hyperventilation, PE, or 3 min of sustained handgrip; and beat-to-beat variation (R-R interval) during deep breathing. The immediate orthostatic HR response (30/15 R-R interval ratio) fell similarly during infusion of ANF-(99–126) or nitroprusside.The findings indicate that in healthy men the function of the autonomic nervous system is not notably impaired by high circulating ANF levels. ANF-(99–126) infused in moderate dosage seems to lower BP largely by non-autonomic mechanisms.The study was supported in part by the Swiss National Science Foundation     

Prevalence of hepatitis C virus genotypes in southern Italy

HCV is ubiquitous. In 50% of all cases it causes chronic hepatitis that often evolves into liver cirrhosis and hepatocellular carcinoma. Recently HCV has been classified in 5 genotypes by Okamoto. The purpose of this study is to evaluate the prevalence of 5 genotypes in Campania, a region of Southern Italy, where the prevalence of anti-HCV antibodies ranges from 0.87 to 4%, and to evaluate the correlation between the HCV genotypes and the severity of histological damage. One hundred and thirty-five anti-HCV positive patients were enrolled and tested by PCR to identify HCV-RNA. One hundred and twenty-four patients resulted HCV-RNA positive. Genotyping was performed as described by Okamoto et al. with minor modifications of the specific primer to type III proposed by Silini et al. Eight patients were negative for all genotypes. Eight patients were positive for type I(1a), 61 for type II(1b), 39 for type III(2a), 11 for type IV(2b) and 1 for type V(3a). In 4 cases two different genotypes were present in the same sample [II(1b)-IV(2b), III(2a)-II(1b) twice, III(2a)-IV(2b)]. Histological evaluation of liver damage showed: CPH (22 cases), minimal CAH (56), severe CAH (31) and liver cirrhosis (15). There was no statistically significant correlation between the 5 genotypes and the severity of histological damage. Data on the prevalence of genotype II(1b) in Italy are similar to those reported for other European countries. The prevalence of genotypes in Southern Italy is similar to that reported in the population of Northern Italy.     

Macular edema induced by phacoemulsification

Purpose: To characterise the association between lens phacoemulsification and the development of macular edema. Methods: We studied 15 patients who underwent lens phacoemulsification in our clinic between January and April 1998 performed by the same surgeon. Ultrasound power and cumulative time was noted. Follow-up was performed at 1 day, 1 week, 1, 3 and 6 months after operation. On each visit corneal thickness, best corrected visual acuity, biomicroscopy and fluorescein angiography were performed. Patients with systemic diseases and/or retinal diseases were not included. Results: Visual acuity was inversely related to the amount of energy delivered during phacoemulsification. In patients who had received more than 1 Joule of energy, fluorescein angiography revealed a higher incidence of blood retinal barrier breakdown. Corneal thickness was not correlated with the ultrasound energy used. Conclusions: Excessive use of power during phacoemulsification may hamper the postoperative evolution of cataract surgery. This revised version was published online in July 2006 with corrections to the Cover Date.     

Study of the antinociceptive action of the ethanolic extract and the triterpene 24-hydroxytormentic acid isolated from the stem bark of Ocotea suaveolens

We describe here the antinociceptive action of the crude extract (CE), the chemical isolation and characterisation and preliminary pharmacological analysis of 24-hydroxytormentic acid, isolated from the stem bark of Ocotea suaveolens (Lauraceae). The CE given by i.p. or p.o. routes, 30 min and 1 h prior, produced significant inhibition of abdominal constrictions caused by acetic acid and also inhibited both phases of formalin-induced licking in mice. The antinociception caused by the CE, given by i.p. and p.o. routes, lasted up to 4 and 2h, respectively. When assessed in the hot-plate test, the CE was inactive. Its antinociceptive action was not associated with non-specific effects such as muscle relaxation or sedation. The antinociception of CE was not influenced by naloxone, L-arginine or DL-p-chlorophenylalanine methyl ester, when assessed against the formalin assay. The triterpene 24-hydroxytormentic acid, given i.p. 30 min before testing, produced significant, dose-related and equipotent antinociceptive action against both phases of formalin-induced licking in mice. These results demonstrate, for the first time, the occurrence of the triterpene 24-hydroxytormentic acid in the stem bark of Ocotea suaveolens, and show that the CE and 24-hydroxytormentic acid exhibit marked antinociception against the neurogenic and the inflamamtory algesic responses induced by formalin in mice. The mechanism by which this compound and CE produces antinociception still remains unclear, but is unlikely to involve the activation of opioid, nitric oxide or serotonin systems or non-specific peripheral or central depressant actions.     

Toxicokinetics of 1,2-diethylbenzene in male Sprague-Dawley rats-part 1: excretion and metabolism of [(14)C]1,2-diethylbenzene.

The excretion and metabolism of neurotoxic 1,2-diethylbenzene (1, 2-DEB) was studied in male Sprague-Dawley rats after i.v. (1 mg/kg) or oral (1 or 100 mg/kg) administration of 1,2-diethyl[U-(14)C]benzene ([(14)C]1,2-DEB). Whatever the treatment, radioactivity was mainly excreted in urine (65-76% of the dose) and to a lower extent in feces (15-23% of the dose), or via exhaled air (3-5% of the dose). However, experiments with rats fitted with a biliary cannula demonstrated that about 52 to 64% of the administered doses (1 or 100 mg/kg) were initially excreted in bile. Biliary metabolites were extensively reabsorbed from the gut and ultimately excreted in urine after several enterohepatic circulations. Insignificant amounts of unchanged 1,2-DEB were recovered in the different excreta (urine, bile, and feces). As reported previously, presence of 1-(2'-ethylphenyl)ethanol (EPE) was confirmed in urine and demonstrated in bile and feces. The two main [(14)C]1,2-DEB metabolites accounted for 57 to 79% of urinary and biliary radioactivity, respectively. Beta-Glucuronidase hydrolysis and electron impact mass spectra results strongly supported their glucuronide structure. Additionally, these two main metabolites were thought to be the glucuronide conjugates of the two potential enantiomers of EPE. The results indicate that the main initial conversion step of the primary metabolic pathway of 1,2-DEB appears to be the hydroxylation of the alpha-carbon atom of the side chain. The presence of two glucuronide conjugates of EPE in the urine in a ratio different from one suggests that the metabolic conversion of 1, 2-DEB is under stereochemical control.     

Pharmacokinetic Study of Triflusal in Elderly Subjects After Single and Repeated Oral Administration

In this study the single-dose and steady-state pharmacokinetics of unchanged triflusal and its metabolite 2-hydroxy-4-trifluoromethylbenzoic acid (HTB) were studied in 12 elderly subjects treated with a single oral administration of 300 mg triflusal and repeated oral administrations of 300 mg triflusal b.i.d. for 13 days. After a single administration, unchanged triflusal is promptly absorbed (t(max) 0.75 h, C(max) 3.83 &mgr;g/mL) and rapidly depleted from the systemic circulation. Its concentration was measurable only up to 1 to 4 h after administration. The apparent terminal half-life was 0.85 h. HTB proves to be quickly generated from triflusal (t(max) 2.00 h, C(max) 39.88 &mgr;g/mL) and slowly eliminated from the body (t = 54.6 h). With the dose regimen proposed, unchanged triflusal does not accumulate in the body. Conversely, HTB plasma concentration builds up progressively toward steady-state levels of approximately 102 &mgr;g/mL after 4 to 5 d of treatment. No substantial change in peak time, elimination rate constant and half-life evaluated after single-dose treatment was observed on multiple-dose regimen for unchanged triflusal and its metabolite HTB. Therefore, our findings do not indicate a time-dependent pharmacokinetics for triflusal. There were no changes in blood pressure, heart rate or laboratory safety date, i.e., biochemical or hematological profiles.