Francesco Corica

Erythropoietin protects against brain ischemic injury by inhibition of nitric oxide formation.

Erythropoietin prevents in vitro glutamate-induced neuronal death and could play a role in the central nervous system. We investigated the in vivo effects of recombinant human erythropoietin after intraperitoneal (i.p.; 25-100 U) or intracerebroventricular (i.c.v.; 0.25-25 U) administration on survival, brain malonildialdehyde (MDA) levels, brain edema, hippocampal neuronal death and brain nitric oxide (NO) synthesis after bilateral carotid occlusion (5 min), followed by reperfusion in the Mongolian gerbil. Peripheral posttreatment with recombinant human erythropoietin reduced postischemic MDA levels, brain edema and increased survival. Either peripheral or i.c.v. posttreatment with recombinant human erythropoietin significantly reduced hippocampal CA1 neuronal loss, observed 7 days after the ischemic event. Increase of nitrite and nitrate (as an index of NO formation) in the hippocampus, as observed after ischemia, was reduced in animals treated with recombinant human erythropoietin. These data suggest that in vivo recombinant human erythropoietin effects on brain ischemic injury could be due to inhibition of NO overproduction.

Leptin increases serotonin turnover by inhibition of brain nitric oxide synthesis

Leptin administration inhibits diencephalic nitric oxide synthase (NOS) activity and increases brain serotonin (5-HT) metabolism in mice. We evaluated food intake, body-weight gain, diencephalic NOS activity, and diencephalic content of tryptophan (TRP), 5-HT, hydroxyindoleacetic acid (5-HIAA), and 5-HIAA/5-HT ratio after intracerebroventricular (ICV) or intraperitoneal (IP) leptin injection in mice. Five consecutive days of ICV or IP leptin injections induced a significant reduction in neuronal NOS (nNOS) activity, and caused a dose-dependent increase of 5-HT, 5-HIAA, and the 5-HIAA/5-HT ratio. Diencephalic 5-HT metabolism showed a significant increase in 5-HT, 5-HIAA, and the 5-HIAA/5-HT ratio 3 hours after a single leptin injection. This effect was maintained for 3 hours and had disappeared by 12 hours after injection. After a single IP leptin injection, the peak for 5-HT, 5-HIAA, and the 5-HIAA/5-HT ratio was achieved at 6 hours. Single injections of ICV or IP leptin significantly increased diencephalic 5-HT content. Leptin-induced 5-HT increase was antagonized by the coadministration of L-arginine only when the latter was ICV injected, whereas D-arginine did not influence leptin effects on brain 5-HT content. Finally, in nNOS-knockout mice, the appetite-suppressant activity of leptin was strongly reduced, and the leptin-induced increase in brain 5-HT metabolism was completely abolished. Our results indicate that the L-arginine/NO pathway is involved in mediating leptin effects on feeding behavior, and demonstrate that nNOS activity is required for the effects of leptin on brain 5-HT turnover.

Aminotransferase and gamma-glutamyltranspeptidase levels in obesity are associated with insulin resistance and the metabolic syndrome

Fatty liver at ultrasounds, with/without raised plasma levels of hepatic enzymes, is common in obesity. In most cases, it is the hallmark of non-alcoholic fatty liver disease (NAFLD), a potentially progressive disease associated with insulin resistance and the metabolic syndrome (MS). We tested the hypothesis that insulin resistance per se might be associated with hepatocellular necrosis. Alanine and aspartate aminotransferases (ALT and AST; no.=799) and gamma-glutamyltranspeptidase (GGT; no.=459) were analyzed in a group of treatment-seeking obese patients recruited in 12 Italian medical centers. Insulin resistance was calculated by the homeostasis model assessment method (HOMA-IR; no.=522). Median ALT and AST increased with increasing obesity class (p=0.001 and p=0.005) and exceeded normal limits in 21.0% of cases. Also HOMA-IR increased with the obesity class (p<0.0001), and was higher in subjects with elevated ALT (median, 4.93 vs 2.89; p<0.0001). A significant correlation was observed between HOMA-IR and ALT (R2=0.208; p<0.0001), as well as between HOMA-IR and AST or GGT (R2=0.112 and R2=0.080; p<0.0001). The correlation was maintained when cases with elevated enzyme levels were omitted from analysis. Diabetes and hypertriglyceridemia were the features of the MS most commonly associated with raised liver enzymes. In logistic regression, after correction for age, gender, BMI and features of the MS, HOMA-IR maintained a highly predictive value for raised ALT, AST and GGT. We conclude that in obesity insulin resistance is a risk factor for raised liver enzyme levels, possibly related to NAFLD.

Relationship between plasma leptin levels and the tumor necrosis factor-α system in obese subjects

OBJECTIVE: To evaluate the relationship between plasma leptin and the tumor necrosis factor-α (TNFα), TNF receptor p60 (TNF-R1) and TNF receptor p80 (TNF-R2) concentrations in obese subjects.DESIGN: Case-control study.SETTING: Outpatient’s Service for Prevention and Treatment of Obesity at the University Hospital.MEASUREMENTS: Body mass index (BMI), waist circumference, hip circumference, waist-to-hip ratio (WHR), fasting plasma glucose, fasting plasma insulin, homeostasis model assessment of insulin resistance (HOMA IR), plasma leptin, TNF α, TNF-R1 and TNF-R2 concentrations were evaluated in obese subjects (n=42) and in age- and gender-matched, lean healthy controls (n=16).RESULTS: In obese subjects, fasting plasma glucose and insulin, HOMA IR, plasma leptin, TNFα, TNF-R1 and TNF-R2 concentrations were significantly higher than in controls. Furthermore, females showed higher leptin, TNF-R1 and TNF-R2 plasma concentrations compared to males, in both control and obese subjects. In control subjects, plasma leptin concentrations showed a direct correlation with BMI (r=0.74, P<0.001), hip circumference (r=0.94, P<0.001), TNF-R1 (r=0.79, P<0.001) and TNF-R2 (r=0.64, P<0.01), and a negative correlation with WHR (r=−0.58, P<0.05). In obese subjects, we found a direct correlation between plasma leptin concentrations and BMI (r=0.67, P<0.001), hip circumference (r=0.66, P<0.001), fasting glucose (r=0.37, P<0.05), fasting insulin (r=0.31, P<0.05), HOMA IR (r=0.38, P<0.05), TNF-R1 (r=0.71, P<0.001) and TNR-R2 (r=0.66, P<0.001), while a negative correlation was found between circulating leptin and WHR (r=−0.44, P<0.01). In multivariate analysis, plasma leptin concentrations were significantly associated with BMI (P=0.015) and gender (P=0.047) in the control group, while in obese subjects, plasma leptin showed a significant association with BMI (P=0.019) and TNF-R1 (P=0.012).CONCLUSIONS: Our results are consistent with the hypothesis that the TNFα system could be involved in the regulation of plasma leptin concentrations in obese subjects.

Serum ionized magnesium levels in relation to metabolic syndrome in type 2 diabetic patients.

Objective: To evaluate circulating serum ionized magnesium (i-Mg) concentrations in patients with type 2 diabetes mellitus, and to investigate its relationship with the components of the metabolic syndrome. Design: cross-sectional study. Setting: Outpatients’ service for diabetic patients at the University Hospital of Messina, Italy. Subjects: 290 patients with type 2 diabetes mellitus. Measures of Outcome: Serum i-Mg was measured by ion selective electrode. Age, gender, body mass index (BMI), waist circumference, blood pressure, fasting glucose, HbA1c, HDL cholesterol, triglycerides, and urinary albumin excretion rate (UAER) were considered in the analyses. Patients with hypomagnesemia, defined as serum i-Mg <0.46 mmol/l, were compared with those having normal serum i-Mg levels, and variables proven to be associated with low i-Mg levels in the univariate analysis were entered in a multivariable logistic regression model to obtain a deconfounded estimate of the association between metabolic parameters and hypomagnesemia. Results: In univariate analysis, serum i-Mg levels were significantly reduced in patients with low HDL cholesterol, high triglycerides values, high waist circumference, high blood pressure, microalbuminuria and clinical proteinuria. Hypomagnesemia was highly prevalent in our study population (N = 143, 49.3%). After adjusting for potential confounders, plasma triglycerides (OR = 4.71; 95% CI = 2.56–8.67), waist circumference (OR = 2.21; 95% CI = 1.21–4.04), microalbuminuria (OR = 2.43; 95% CI = 1.16–5.08) and clinical proteinuria (OR = 2.04; 95% CI = 1.02–5.68) were independently associated with hypomagnesemia. Conclusions: Hypomagnesemia is highly prevalent in diabetic outpatients. High plasma triglycerides, waist circumference and albuminuria are independent correlates of hypomagnesemia.

In vivo evidence that erythropoietin has a neuroprotective effect during subarachnoid hemorrhage

To ascertain in vivo whether recombinant human erythropoietin has a neuroprotective effect on the cortex during subarachnoid hemorrhage, 56 rabbits were divided into the following groups: Group 1 control sham operated plus placebo (n=14; saline solution - NaCl 0.9%); Group 2 control sham operated plus recombinant human erythropoietin (n=14); Group 3 subarachnoid hemorrhage plus placebo (n=14); Group 4 subarachnoid hemorrhage plus recombinant human erythropoietin (n=14; intraperitoneal administration of recombinant human erythropoietin immediately after inducing subarachnoid hemorrhage). In none of the Groups 1 and 2 animals was subarachnoid hemorrhage induced. In Group 3 rabbits, an increase in locomotor activity (open field apparatus) was observed 24, 48 and 72 h after surgery, and the mortality rate was 42.9% within 72 h after surgery, and, no increase in locomotor activity was observed in Group 4 rabbits, which survived for at least 72 h. Our findings suggest that recombinant human erythropoietin may be of benefit in the treatment of subarachnoid hemorrhage.

Effect of fluvastatin on proteinuria in patients with immunoglobulin A nephropathy

3‐Hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitors are established drugs for the treatment of hypercholesterolemia, but several studies have shown that benefits obtained with these drugs are not causally related only to regression of cholesterol lowering. Moreover, in experimental models of progressive renal disease, statins have reduced the extent of glomerulosclerosis. This study evaluated the antiproteinuric effect of a daily dose of 40 mg fluvastatin for 6 months in moderately proteinuric patients with immunoglobulin A nephropathy, stable renal function, and no indicators of poor long‐term prognosis. The effects of therapy were evaluated on the basis of 24‐hour proteinuria (total proteinuria and albuminuria), albuminemia, creatinine clearance, cholesterol, and triglyceride values. Renal function remained stable in all patients. A significant decrease in proteinuria was observed after 6 months of therapy and persisted for all the observations. An increase in serum albumin was observed after 6 months of therapy. This study suggests that there is an antiproteinuric effect of HMG‐CoA reductase inhibitors in moderately proteinuric patients with immunoglobulin A nephropathy. (Clin Pharmacol Ther 2000;67:427‐31.)

Potentially inappropriate medications and functional decline in elderly hospitalized patients.

OBJECTIVES: To verify whether the use of potentially inappropriate medications (PIMs) is associated with loss of independence in elderly in‐patients by promoting adverse drug reactions (ADRs).

Metabolic syndrome, psychological status and quality of life in obesity: The QUOVADIS Study

Objective:We aimed to investigate the association of the clinical variables of the metabolic syndrome (MS) and psychological parameters on health-related quality of life (HRQL) in obesity. In particular, our aim was to investigate the relative impact of physical symptoms, somatic diseases and psychological distress on both the physical and the mental domains of HRQL.Design:Cross-sectional study.Subjects:A cohort of 1822 obese outpatients seeking treatment in medical centers.Measurements:HRQL was measured by the standardized summary scores for physical (PCS) and mental (MCS) components of the Short Form 36 Health Survey (SF-36). Patients were grouped according to tertiles of PCS and MCS. Metabolic and psychological profiles of PCS and MCS tertiles were compared by discriminant analysis.Results:The profile of metabolic and psychological variables was tertile-specific in 62.4 and 68.3% of patients in the lowest and highest tertiles of PCS, respectively, while concordance was low in the mid-tertile (32.8%). Concordance was very high in the lowest (74.4%) and in the highest (75.5%) tertiles of MCS, and was fair in the mid-tertile (53.2%). The main correlates of PCS were obesity-specific and general psychological well-being, BMI, body uneasiness, binge eating, gender and psychiatric distress. Only hypertension and hyperglycemia qualified as correlates among the components of MS. The components of MS did not define MCS.Conclusions:Psychological well-being is the most important correlate of HRQL in obesity, both in the physical and in the mental domains, whereas the features of MS correlate only to some extent with the physical domain of HRQL.

Cold Pressor Test Raises Serum Concentrations of ICAM-1, VCAM-1, and E-Selectin in Normotensive and Hypertensive Patients

In patients with essential hypertension, elevated soluble E-selectin (sE-selectin) levels may indicate endothelial cell injury or activation. We therefore sought to ascertain whether arterial blood pressure increased by the cold pressor test can modify serum concentrations of sE-selectin and other soluble forms of adhesion molecules, such as soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1), or the expression of any adhesion molecules in circulating monocytes and lymphocytes. Our findings show that levels of sE-selectin, sVCAM-1, and sICAM-1 are higher in patients with essential hypertension than in normotensive subjects (sICAM-1, 380 +/- 52 versus 262 +/- 96 ng/mL, P<.05; sVCAM-1, 720 +/- 52 versus 625 +/- 38 ng/mL, P<.05; and sE-selectin, 75 +/- 21 versus 61 +/- 22 ng/mL, P<.05). Furthermore, in normotensive and hypertensive patients, the cold pressor test caused an increase in serum concentrations of sICAM-1, sVCAM-1, and sE-selectin, but it did not cause changes in the expression of adhesion molecules in circulating monocytes and lymphocytes. High arterial blood pressure may therefore increase the production of serum adhesion molecules, probably through endothelial activation.