Effect of non-respiratory alkalosis on brain tissue and cerebral blood flow in rats with damaged blood-brain barrier

Acute alterations in plasma bicarbonate concentration have minimal effects on intracerebral pH and cerebral blood flow, perhaps due to blood-brain barrier mechanisms. To test this hypothesis, the consequences of an acute rise in the plasma bicarbonate concentration were studied in anesthetized rats previously subjected to an acute pressure pulse in the carotid system with unilateral damage to the blood-brain barrier. In rats subjected to a "heavy" hypertensive insult, the hemisphere on the side of the lesion showed a lactic acidosis, edema, and a depression of cerebral blood flow. An increase in the plasma bicarbonate concentrations of 15--20 mEq/1 during 35 minutes provoked a marked rise in the total CO2 content of this hemisphere, and a further increase in the lactate concentration, but did not later the brain edema nor affect further the already very low cerebral blood flow. An increase in the lactate concentration and a decrease of cerebral blood flow in the "reference" hemisphere indicated that the lesion was not completely unilateral. In rats subjected to a "moderate" hypertensive insult the changes were less pronounced and statistically not significant for all the parameters. There results illustrate the importance of an intact blood-brain barrier for the maintenance of intracerebral pH in the face of acute alterations in plasma [HCO3]. The impaired cerebral blood flow after an acute hypertensive insult did not appear to be influenced by the intracerebral [HCO3].     

Acute changes in forearm haemodynamics produced by cigarette smoking in healthy normotensive non-smokers are not influenced by propranolol or pindolol

Summary The aim of the present study was to examine the effect of cigarette smoking in healthy non-smokers on blood pressure and forearm haemodynamics after acute oral administration of non-selective -adrenoceptor blockers with and without intrinsic sympathomimetic activity, viz. pindolol 15 mg and propranolol 80 mg. A preliminary study was done to compare cigarette smoking and sham smoking to evaluate the time-course of the haemodynamic effects of cigarette smoking. The second experiment was then carried out in the same six volunteers, according to a double-blind randomized placebo-controlled crossover design, to evaluate the possible effect of pre-treatment with -adrenoceptor blockers on blood pressure, heart rate and forearm haemodynamics (forearm blood flow, brachial artery diameter and brachio-radial pulse-wave velocity) measured at baseline, during smoking and every five minutes up to 1 h afterwards.No major difference from placebo in blood pressure or forearm haemodynamics was found and pre-treatment with beta-blockers did not prevent the acute vascular effects of cigarette smoking.     

Cardiac anomalies in chronic renal failure

PRINCIPAL CARDIOVASCULAR COMPLICATIONS IN END STAGE RENAL DISEASE: Cardiovascular diseases are the leading causes of morbidity and mortality in end stage renal disease patients. Very often, complications observed are left ventricular hypertrophy and various forms of arterial degenerative lesions involving coronary arteries, less frequently pericarditis and calcifying valvulopathy are diagnosed. THE REASONS ARE COMPLEX: Risk factors can be either specific of uremia per se such as anemia, overhydration, fistula or the same as in the general population. Hemodynamic alterations including tensile stress or blood flow play a major role associated to various locally or generally generated substances whose role remains currently to be determined. THEIR TREATMENTS: Treatments of cardiovascular complications are not specific in this end stage renal disease population but are more often the treatment of the etiology: reduction of fistula blood flow, increase of hemoglobin, best control of weight gain between two hemodialysis sessions or blood pressure control.     

All-cause and cardiovascular mortality using the different definitions of metabolic syndrome

The aim of the present study was to assess the risk of all-cause and cardiovascular disease (CVD) mortality in subjects identified as having metabolic syndrome (MS) using either the recent International Diabetes Federation (IDF) definition or the revised National Cholesterol Educational Program (NCEP-R) definition, but not the original NCEP (2001) definition. The study population was composed of 84,730 men and women without CVD aged > or =40 years who had a health checkup at the IPC Center. Follow-up for mortality was 4.7 +/-1.7 years. Prevalences of MS were 9.6%, 21.6%, and 16.5% according to the NCEP, IDF, and NCEP-R definitions, respectively. Compared with subjects without MS, risks of all-cause mortality associated with MS were 1.63 (95% confidence interval [CI] 1.38 to 1.93) with the NCEP, 1.25 (95% CI 1.09 to 1.45) with the IDF, and 1.32 (95% CI 1.13 to 1.53) with the NCEP-R, and risks of CVD mortality were 2.05 (95% CI 1.28 to 3.28), 1.77 (95% CI 1.18 to 2.64), and 1.64 (95% CI 1.08 to 2.50), respectively. In subjects with MS detected using the IDF and NCEP-R definitions, but not the NCEP definition, risks of all-cause mortality were 1.07 (95% CI 0.89 to 1.28) and 0.92 (95% CI 0.73 to 1.18) and 1.42 (95% CI 0.86 to 2.34) and 1.07 (95% CI 0.55 to 2.09) for CVD mortality, respectively. In conclusion, in a large French population, the recent definitions of MS almost double the prevalence compared with the original definition. Subjects identified as having MS using only the recent definitions and not the original definition did not have higher rates of all-cause and CVD mortality compared with subjects without MS during follow-up.     

Dose and concentration-effect relations for rilmenidine

The dose-effect and concentration-effect relations of rilmenidine, a new alpha 2 agonist, were evaluated for the hemodynamic and side-effect responses to single oral doses. Two studies were performed in a double-blind manner: study I in 8 healthy subjects and study II in 10 hypertensive patients. In the course of five 24-hour periods, each separated by at least 1 week, the following 5 treatments were administered in a random order: placebo, rilmenidine (0.5, 1, 2 and 3 mg). Blood pressure was measured with a Roche arteriosonde (study I) or a sphygmomanometer (study II). Sedation was measured using a visual analog scale. Dry mouth was assessed by measuring the salivary flow (study I) or by visual analog scale (study II). Plasma concentration of rilmenidine was assayed by gas chromatography linked with mass spectrometry. The antihypertensive and sedative effects (area under curve) were directly related to the dose and to the log of the plasma concentration of rilmenidine. In contrast to the 2- and 3-mg doses, rilmenidine (0.5 and 1 mg) did not induce orthostatic hypotension, a significant decrease in heart rate or a significant dryness of mouth. At doses of 0.5 and 1 mg, the effects of rilmenidine on sedation were not consistent in both studies: sedation was significant in study I but did not differ from placebo in study II. These studies show that rilmenidine, in common with other alpha 2 agonists, decreases blood pressure in a dose-dependent manner, in normotensive as well as in hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Expert consensus document on arterial stiffness: methodological issues and clinical applications.

In recent years, great emphasis has been placed on the role of arterial stiffness in the development of cardiovascular diseases. Indeed, the assessment of arterial stiffness is increasingly used in the clinical assessment of patients. Although several papers have previously addressed the methodological issues concerning the various indices of arterial stiffness currently available, and their clinical applications, clinicians and researchers still report difficulties in selecting the most appropriate methodology for their specific use. This paper summarizes the proceedings of several meetings of the European Network for Non-invasive Investigation of Large Arteries and is aimed at providing an updated and practical overview of the most relevant methodological aspects and clinical applications in this area.     

Efficacy and tolerance of Algosteril (calcium alginate) versus Jelonet (paraffin gauze) in the treatment of scalp graft donor sites in children. Results of a randomized study

Split skin graft is frequently needed in the treatment of burned patients. Scalp is often free of burns. Due to its good skin quality and important surface, scalp is a very interesting skin donor site, specially in case of children. A controlled, randomised clinical trial was carried out in 10 French Plastic Surgery or Burns Units. It assessed the efficacy and the acceptability of calcium alginate dressing (Algosteril) versus paraffin gauze dressing (Jelonet) in the treatment of scalp donor sites in children. 67 children (mean age 54 months) entered the study, 34 in the alginate group and 33 in the control group. Follow-up visits were on day 2/d3, d5/d6, Day complete healing, d30 and d60 after surgery. The two groups were comparable on inclusion (demographic characteristics, burn nature and surface, donor site surface and thickness of split skin graft). The mean healing time was 10 and 11 days for Algosteril and Jelonet group respectively (ns). The quality of the newly formed tissue was estimated to permit a sooner skin reharvesting in the Algosteril group than in the control group (p = 0.003). Bleeding through dressing was significantly less important in the Algosteril group (p = 0.02). Changes were considered by investigators less painful with Algosteril on day complete healing (p = 0.0096). Hair growth is homogenous in both groups on day 30 and day 60 (ns). These results showed that scalp is a very interesting skin donor site and that Algosteril is of a real interest in donor site treatment.