E‐selectin gene in essential hypertension: a case‐control study

Background

Hypertension is associated with endothelial cell dysfunction. E‐selectin, an endothelial cell adhesion molecule, is specific for endothelial cell activation. Polymorphism in E‐selectin gene has recently been identified among which Leu554Phe E‐selectin gene polymorphism is least investigated in essential hypertension. This study reports the association of E‐selectin gene Leu554Phe polymorphism and the expression of E‐selectin gene in patients with essential hypertension.

Materials and methods

We analysed the Leu554Phe polymorphism and expression of E‐selectin gene in 250 patients with essential hypertension and 250 normal healthy controls. Genotyping of Leu554Phe polymorphism was performed by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP), and the expression of E‐selectin gene at mRNA and protein levels were carried out by real‐time PCR and Western blot, respectively.

Results

A significant association of E‐selectin genotypes (CT + TT) with essential hypertension (P < .0001, Odds ratio = 2.2 [1.58‐3.24] at 95% CI) was observed. The expression of mRNA for E‐selectin gene in patients with essential hypertension was ~12‐fold higher as compared to control. We observed an elevated level of E‐selectin protein expression (up to 1.9 times) in patients as compared to controls.

Conclusions

A significant association of E‐selectin (Leu554Phe) gene and increased expression of E‐selectin gene at mRNA and protein levels in patients might be related to the genetic predisposition to develop essential hypertension.     

High-fructose diet decreases catalase mRNA levels in rat tissues

Insulin resistance and hyperinsulinemia have recently been identified as independent determinants of several risk factors for cardiovascular disease. The generation of reactive oxygen species (ROS) may play an important role as a final common mediator by which glucose and insulin resistance might contribute to development of cardiovascular disease and hypertension. The aim of the present study was to evaluate changes on mRNA expression of antioxidant enzymes [catalase, Cu-Zn superoxide dismutase (Cu-ZnSOD), MnSOD], blood pressure and metabolic parameters in insulin resistance that follow feeding normotensive Wistar rats a high-fructose-enriched diet. In our investigation 26 normal male Wistar rats were fed a high-fructose diet for 2 weeks (no.=14) or normal chow to serve as a control group (no.=12). In vivo insulin resistance was verified in a subgroup of control and fructose-fed rats by the euglycemic hyperinsulinemic clamp technique at 2 different insulin infusion rates, 29 (submaximal stimulation) and 290 (maximal stimulation) pmol/kg/min respectively. The glucose infusion rate (GIR) was not significantly different in the two groups during the submaximal infusion of insulin (1.4 +/- 0.8 mmol/kg/min in fructose-fed rats vs 1.6 +/- 0.7 mmol/kg/min in control rats, NS) while in fructose-fed rats it was significantly lower (-29.8%) than in control rats during maximal infusion of insulin (2.6 +/- 0.3 mmol/kg/min vs 3.7 +/- 0.3 mmol/kg/min, p<0.05). Fructose feeding markedly reduced the expression of catalase mRNA and Cu-ZnSOD mRNA in the liver, catalase mRNA in the heart (p<0.05). A tendency of fructose feeding to reduce the expression of antioxidant enzymes in skeletal muscle and adipose tissue was also observed (NS). Fructose feeding also increased plasma uric acid (119.9 +/- 30.4 vs 42.1 +/- 10 pmol/l, p<0.05) and systemic blood pressure (128 +/- 4 vs 109 +/- 5 mmHg, p<0.05) respect to control animals. No significant changes were observed in plasma levels of glycemia and tryglycerides. Our study suggests that in non-hyperglycemic, fructose-fed insulin-resistant rats the expression of catalase is inhibited in liver and heart. This condition might lead to higher susceptibility to oxidative stress in insulin resistance. However, an adaptive cellular response to maintain the effectiveness of intracellular signaling pathways mediated by insulin-activated hydrogen peroxide generating systems may also be hypothesized.     

The effect of hyperoxia on inflammation and platelet responses in an ex vivo extracorporeal membrane oxygenation circuit

Use of extracorporeal membrane oxygenation (ECMO) is expanding, however, it is still associated with significant morbidity and mortality. Activation of inflammatory and innate immune responses and hemostatic alterations contribute to complications. Hyperoxia may play a role in exacerbating these responses. Nine ex vivo ECMO circuits were tested using fresh healthy human whole blood, with two oxygen levels: 21% inspired fraction of oxygen (FiO₂; mild hyperoxia; n = 5) and 100% FiO₂ (severe hyperoxia; n = 4). Serial blood samples were taken for analysis of platelet aggregometry, leukocyte activation, inflammatory, and oxidative stress markers. ECMO resulted in reduced adenosine diphosphate- (P < .05) and thrombin receptor activating peptide-induced (P < .05) platelet aggregation, as well as increasing levels of the neutrophil activation marker, neutrophil elastase (P = .013). Additionally, levels of the inflammatory chemokine interleukin-8 were elevated (P < .05) and the activity of superoxide dismutase, a marker of oxidative stress, was increased (P = .002). Hyperoxia did not augment these responses, with no significant differences detected between mild and severe hyperoxia. Our ex vivo model of ECMO revealed that the circuit itself triggers a pro-inflammatory and oxidative stress response, however, exposure to supra-physiologic oxygen does not amplify that response. Extended-duration studies and inclusion of an endothelial component could be beneficial in characterizing longer term changes.     

Spontaneous cryptococcal peritonitis with fungemia in patients with decompensated cirrhosis: Report of two cases

Cryptococcus neoformans is encapsulated yeast that predominately infects immunocompromised individuals. Liver disease is an under-recognized predisposition for cryptococcal disease. We report two nonalcoholic, nondiabetic, and human immunodeficiency virus - negative cirrhotic patients, with spontaneous cryptococcal peritonitis. Cryptococcus infection was diagnosed by culture of ascitic fluid and peripheral blood in both. We treated the first patient with amphotericin-B, but he expired. The second patient with earlier diagnosis, survived to discharge with fluconazole treatment. We suggest a high clinical suspicion for Cryptococcus as a possible etiology of spontaneous peritonitis in cirrhotic patients.     

Localized heat urticaria

The pathophysiology of localized heat urticaria was studied by performing a heat challenge on a patient with this disease. Serum levels of total hemolytic complement, C3, and factor B decreased following heat challenge, whereas levels of C4 and C5 did not. Plasma histamine levels remained unchanged. Electron microscopic studies of affected tissue revealed endothelial cell damage and neutrophilic degranulation in the affected area. Mast cells remained intact. These data imply that activation of the alternative complement pathway is involved in the pathogenesis of localized heat urticaria and that mast cell histamine release does not play a significant role in this disease.     

Synthesis and evaluation of the antioxidant and antiinflammatory activities of some benzo[l]khellactone derivatives and analogues

Treatment of 3-hydroxy-beta-lapachone 4 with ylide 5 gave the coumarin derivative 7a, which was transformed to compounds 10-14. Compound 14 was then transformed to benzo[f]seselin 15 as well as to benzo[l]khellactones 16, 18 from which the title compounds 17, 19(I), 19(II), 20, 21(I) and 21(II) were prepared. All the tested compounds were found to interact with DPPH in a concentration and time dependent manner. All the tested compounds highly inhibited the soybean lipoxygenase, whereas compounds 12, 17 and 19(II) highly compete with DMSO for (*)OH. Compounds 7a, 7b, 12 and 17 induced at 48.7-58.9% protection against carrageenin induced rat paw edema.