The objective of the present study was to evaluate the effects of inhaled and intravenous sildenafil on the pulmonary endothelium-dependent relaxations, the hemodynamic profile and oxygenation after cardiopulmonary bypass. Five groups of Landrace swine were compared: 1) control; 2) cardiopulmonary bypass: 90 min of normothermic cardiopulmonary bypass; 3) precardiopulmonary bypass sildenafil nebulization; 4) postcardiopulmonary bypass sildenafil nebulization; 5) intravenous sildenafil administration prior to cardiopulmonary bypass. All groups underwent a 60-min period of pulmonary reperfusion after cardiopulmonary bypass. Vascular reactivity of second-degree pulmonary arteries was evaluated in response to acetylcholine and bradykinin. Cardiopulmonary bypass caused a significant decrease in endothelium-dependent relaxations to both agonists; this dysfunction was prevented by administration of sildenafil, both intravenous and inhaled (P < 0.05). Both administration routes prevented the significant increase in mean pulmonary arterial pressure with a safe hemodynamic profile. Moreover, intravenous and inhaled sildenafil after cardiopulmonary bypass also prevented the increase in alveoloarterial gradient (P < 0.05). Both sildenafil formulations of administration prevent the occurrence of pulmonary endothelial dysfunction. Depending on the administration moment and the route, the administration of sildenafil improves the hemodynamic profile and post-cardiopulmonary bypass oxygenation.
It remains presently unknown whether vascular reactivity is impaired and whether maladaptive cardiac remodeling occurs before the onset of overt obesity and in the absence of hyperlipidemia. Normal female rats were fed a high-fat diet for 8 weeks and were associated with a modest nonsignificant increase of body weight (standard diet, 300 ± 10, versus high-fat diet, 329 ± 14 g) and a normal plasma lipid profile. In rats fed a high-fat diet, systolic (171 ± 7 mm Hg) and diastolic blood pressures (109 ± 3) were increased compared to a standard diet (systolic blood pressure, 134 ± 8; diastolic blood pressure, 96 ± 5 mm Hg), and acetylcholine-dependent relaxation of isolated aortic rings (high-fat diet, 22 ± 5%, versus standard diet, 53 ± 8%) was significantly reduced. Furthermore, perivascular fibrosis was detected in the heart of rats fed a high-fat diet. The exogenous addition of resveratrol (trans-3,5,4′-trihydroxystilbene) (0.1 μM) to aortic rings isolated from rats fed a high-fat diet restored acetylcholine-mediated relaxation (47 ± 9%). The administration of resveratrol (20 mg/kg/day for 8 weeks) to rats fed a high-fat diet prevented the increase in blood pressure and preserved acetylcholine-dependent relaxation of isolated aortic rings. However, resveratrol therapy failed to attenuate the perivascular fibrotic response. These data have demonstrated that a high-fat diet fed to normal female rats can elicit a hypertensive response and induce perivascular fibrosis before the development of overt obesity and in the absence of hyperlipidemia. Resveratrol therapy can prevent the hypertensive response in female rats fed a high-fat diet but is without effect on the progression of perivascular fibrosis.
This work describes a study of the effects of combined oral contraceptives (OCs) on lipid biosynthesis in platelets of female rats and women. A highly significant hypercoagulability due solely to increased activity of platelet factor 3 can be observed in women using combined OCs. The phospholipidic nature of factor 3 has been demonstrated. Phospholipids are implicated in the aggregation of platelets because they are the essential constituents of the platelet membranes and the precursors of prostaglandins. Platelets actively synthesize their own lipids, and combined OCs modify serum lipid metabolism. In each experiment, a control group of rats weighing 180-200 g received .5 ml/g body weight of olive oil once daily for 4 days. 3 groups of experimental rats received .5 ml of olive oil containing 10 mcg of ethinyl estradiol (EE) and 250 mcg of lynestrenol or 10 mcg of EE alone or 250 mcg of lynestrenol alone per 100 g of body weight. The doses were the equivalent of 1/2 that required to block ovulation in adult female rats. Platelets were studied on the 5th day. In another experiment a group of rats was given a triple dose of EE and lynestrenol on the 1st study day. Platelets were studied on days 1, 3, 5, and 8. Lipid biosynthesis was studied by incorporation of carbon 14 labelled acetate and mevalonate precursors. Radioactivity was measured for the lipids as a whole and for different lipid fractions separated by chromatography. Incorporation of carbon 14 labelled acetate was augmented by 44.6% in animals receiving EE and lynestrenol and by 43% in animals receiving EE alone, but was not modified in animals receiving lynestrenol alone. In animals receiving a triple dose of hormones, incorporation was maximal on the 3rd day, diminished on the 5th day, and normal after 8 days. The EE component thus appears to be responsible for modifications in platelet lipid metabolism during OC use. The response appears after a latency period and seems to be irreversible, since the duration of life of platelets is 4-5 days. The increased synthesis occurs mainly in cholesterol and its precursors lanosterol and dihydrolanosterol. Supplemental in vitro experiments suggested that lanosterol was responsible for the increased platelet activity. 17 nonsmoking women aged 32 years on average who took no medications were compared to 18 women aged 30 years on average who took OCs with estrogen doses of 30-40 mcg for at least 6 months. As in the rat studies, lipid biosynthesis was analyzed by incorporation of carbon 14 labelled acetate or mevalonate in the platelets. Compared to control women, the women on OCs showed an augmentation of 37% in incorporation of mevalonate and 28% of acetate. The labelled acetate showed a higher incorporation at the level of each of the lipid fractions. Mevalonate showed the highest augmentation in the lanosterol fraction. 43% of the women taking OCs showed an increased platelet sensitivity to thrombine. The increased sensitivity was correlated with increased lanosterol synthesis, but the relation was only observed in women taking OCs. The phenomenon is of interest because of its possible relationship to the increased risk of thromboembolic accidents in women taking OCs.
Abstract Health economic evaluations are comparative analyses of alternative courses of action in terms of their costs and consequences. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement, published in 2013, was created to ensure health economic evaluations are identifiable, interpretable, and useful for decision making. It was intended as guidance to help authors report accurately which health interventions were being compared and in what context, how the evaluation was undertaken, what the findings were, and other details that may aid readers and reviewers in interpretation and use of the study. The new CHEERS 2022 statement replaces previous CHEERS reporting guidance. It reflects the need for guidance that can be more easily applied to all types of health economic evaluation, new methods and developments in the field, as well as the increased role of stakeholder involvement including patients and the public. It is also broadly applicable to any form of intervention intended to improve the health of individuals or the population, whether simple or complex, and without regard to context (such as health care, public health, education, social care, etc.). This summary article presents the new CHEERS 2022 28-item checklist and recommendations for each item. The CHEERS 2022 statement is primarily intended for researchers reporting economic evaluations for peer reviewed journals as well as the peer reviewers and editors assessing them for publication. However, we anticipate familiarity with reporting requirements will be useful for analysts when planning studies. It may also be useful for health technology assessment bodies seeking guidance on reporting, as there is an increasing emphasis on transparency in decision making.
Ever since firms started using computers for processing their business data, researchers and practitioners have been preoccupied by the successful implementation of information systems (IS). Over the years, researchers have studied several aspects of IS implementation, be it measuring success or developing and testing models that explain IS project success or failure. However, up to now, few IS implementation studies have focused on the role played by the project leader. This paper presents the results of a study of 139 IS project managers. The study examined both the tactics adopted by these project managers to influence people, and their level of decision authority. It then attempted to determine if these two characteristics varied along with the project's organizational structure. The findings of the study point to the mediating role played by project managers' level of decision authority in linking organization structures to influence tactics. While influence tactics used do not vary across project structures, they do so across various levels of decision authority. In turn, the level of authority of project leaders varies across structures and steadily increases on the functional-project continuum. Three influence profiles emerged from the study, namely, the humanist, the political and the authoritarian project manager, providing further interpretation to influence tactics and behavior in an IS development context.
The lipid-lowering agent probucol may be efficacious, through its antioxidant properties, to limit and reverse the vascular endothelial dysfunction associated with left ventricular hypertrophy (LVH). LVH was induced by performing an aortic banding (AB) on swine, except for controls (group 1). The untreated AB group received a placebo (group 2) whereas the treated groups received probucol (1000 mg/d orally); the third group began its treatment on the day of the banding (for 60 d), the fourth began on day 30 and the fifth on day 60 after AB (both for 30 d). Hypertrophy was assessed by echocardiography and histology. Coronary vascular reactivity was evaluated in organ chambers and endothelial function by quantification of NO2−/NO3− and cyclic guanosine-3′,5′-monophosphate. To assess oxidative stress, hydroperoxides and angiotensin II levels as well as superoxide dismutase activity were evaluated. After treatment with probucol, a significant decrease in left ventricle/body weight ratio was observed compared with the untreated group. Dose-response curves of the probucol groups showed an improvement in endothelium-dependent relaxations, associated with increased nitric oxide bioavailability and decreased angiotensin II and hydroperoxide levels. In conclusion, the antioxidant probucol limited the development and induced the regression of LVH and the associated coronary endothelial dysfunction.