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Chronic Hypertension (chronic + hypertension)
Selected AbstractsEffects of lipopolysaccharide on vascular reactivity and mortality in ratsAUTONOMIC & AUTACOID PHARMACOLOGY, Issue 5-6 2002J. P. L. Nunes Summary 1 The effects of intraperitoneal (i.p.) lipopolysaccharide on vascular reactivity to noradrenaline in rat aorta under different conditions of passive tension, as well as on mortality in normotensive and hypertensive rats, were studied. 2 Concentration,response curves to noradrenaline were obtained in aorta rings, at two levels of passive tension: 3 and 0.5 g, from control and lipopolysaccharide-treated Wistar rats. Contractile responses were expressed as percentage of the maximal response to noradrenaline obtained in the beginning of the experiment at a resting tension of 2 g. The maxima were significantly larger (P < 0.05) at 3 g than at 0.5 g in both groups of rats: 117.8 vs. 62.3%, respectively, for control animals; 85.8 vs. 32.5%, respectively, for lipopolysaccharide-treated rats. 3 The 24-h mortality after the i.p. administration of lipopolysaccharide was lower in spontaneously hypertensive rats (1/12; 8%), when compared with control Wistar,Kyoto rats (5/11; 45%). However, mortality was higher in Wistar,Kyoto made hypertensive by 8-day administration of corticosterone (6/6; 100%). 4 We conclude that a differential sensitivity to noradrenaline of aortic smooth muscle at two different levels of passive tension is still present in lipopolysaccharide-treated animals. Chronic hypertension in SHR rats is associated with resistance to the lethal effects of lipopolysaccharide, whereas abrupt-onset hypertension induced by corticosterone leads to an increased mortality. 5 These results are compatible with the myofibrillary hypothesis, which explains vascular hyper-reactivity in chronic arterial hypertension, by postulating that a more favourable relative position (and/or proportion) for actin and myosin occurs, whereas in states of vascular hypo-reactivity, such as vasodilatory shock, the opposite phenomenon may exist. [source] Assessment of gestational age and neuromaturationDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2005Marilee C. Allen Abstract Neuromaturation is the functional development of the central nervous system (CNS). It is by its very nature a dynamic process, a continuous interaction between the genome and first the intrauterine environment, then the extrauterine environment. Understanding neuromaturation and being able to measure it is fundamental to infant neurodevelopmental assessment. Fetal and preterm neuromaturation has become easier to observe with the advent of prenatal ultrasonography and neonatal intensive care units. A number of measures of degree of fetal maturation have been developed and used to estimate gestational age (GA) at birth. The most reliable measures of GA are prenatal measures, especially from the first trimester. Postnatal GA measurements tend to be least accurate at the extremes of gestation, that is, in extremely preterm and post-term infants. Observations of measures of neuromaturation in infants born to mothers with pregnancy complications, including intrauterine growth restriction, multiple gestation, and chronic hypertension, have led to the discovery that stressed pregnancies may accelerate fetal pulmonary and CNS maturation. This acceleration of neuromaturation does not occur before 30 weeks' gestation and has a cost with respect to cognitive limitations manifested in childhood. The ability to measure fetal and preterm neuromaturation provides an assessment of neurodevelopmental progress that can be used to reassure parents or identify at risk infants who would benefit from limited comprehensive follow-up and early intervention services. In addition, measures of neuromaturation have the potential to provide insight into mechanisms of CNS injury and recovery, much-needed early feedback in intervention or treatment trials and a measure of early CNS function for research into the relationships between CNS structure and function. © 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:21,33. [source] Patients Presenting to the Emergency Department With Non-specific Complaints: The Basel Non-specific Complaints (BANC) StudyACADEMIC EMERGENCY MEDICINE, Issue 3 2010Marek Nemec MD Abstract Objectives:, Patient management in emergency departments (EDs) is often based on management protocols developed for specific complaints like dyspnea, chest pain, or syncope. To the best of our knowledge, to date no protocols exist for patients with nonspecific complaints (NSCs) such as "weakness,""dizziness," or "feeling unwell." The objectives of this study were to provide a framework for research and a description of patients with NSCs presenting to EDs. Methods:, Nonspecific complaints were defined as the entity of complaints not part of the set of specific complaints for which evidence-based management protocols for emergency physicians (EPs) exist. "Serious conditions" were defined as potentially life-threatening or those requiring early intervention to prevent health status deterioration. During a 6-month period, all adult nontrauma patients with an Emergency Severity Index (ESI) of 2 or 3 were prospectively enrolled, and serious conditions were identified within a 30-day period. Results:, The authors screened 18,261 patients for inclusion. A total of 218 of 1,611 (13.5%) nontrauma ESI 2 and 3 patients presented with NSCs. Median age was 82 years (interquartile range [IQR] = 72 to 87), and 24 of 218 (11%) were nursing home inhabitants. A median of 4 (IQR = 3 to 5) comorbidities were recorded, most often chronic hypertension, coronary artery disease, and dementia. During the 30-day follow-up period a serious condition was diagnosed in 128 of 218 patients (59%). The 30-day mortality rate was 6%. Conclusions:, Patients with NSC presenting to the ED are at high risk of suffering from serious conditions. Sensitive risk stratification tools are needed to identify patients with potentially adverse health outcomes. ACADEMIC EMERGENCY MEDICINE 2010; 17:284,292 © 2010 by the Society for Academic Emergency Medicine [source] Plasma serotonin levels and the platelet serotonin transporterJOURNAL OF NEUROCHEMISTRY, Issue 1 2007B. Brenner Abstract Serotonin (5HT) is a platelet-stored vasoconstrictor. Altered concentrations of circulating 5HT are implicated in several pathologic conditions, including hypertension. The actions of 5HT are mediated by different types of receptors and terminated by a single 5HT transporter (SERT). Therefore, SERT is a major mechanism that regulates plasma 5HT levels to prevent vasoconstriction and thereby secure a stable blood flow. In this study, the response of platelet SERT to the plasma 5HT levels was examined within two models: (i) in subjects with chronic hypertension or normotension; (ii) on platelets isolated from normotensive subjects and pretreated with 5HT at various concentrations. The platelet 5HT uptake rates were lower during hypertension due to a decrease in Vmax with a similar Km; also, the decrease in Vmax was primarily due to a decrease in the density of SERT on the platelet membrane, with no change in whole cell expression. Additionally, while the platelet 5HT content decreased 33%, the plasma 5HT content increased 33%. Furthermore, exogenous 5HT altered the 5HT uptake rates by changing the density of SERT molecules on the plasma membrane in a biphasic manner. Therefore, we hypothesize that in a hypertensive state, the elevated plasma 5HT levels induces a loss in 5HT uptake function in platelets via a decrease in the density of SERT molecules on the plasma membrane. Through the feedback effect of this proposed mechanism, plasma 5HT controls its own concentration levels by modulating the uptake properties of platelet SERT. [source] Women With High-Risk Pregnancies, Problems, and APN InterventionsJOURNAL OF NURSING SCHOLARSHIP, Issue 4 2007Dorothy Brooten Purpose: To (a) describe women's prenatal and postpartum problems and advanced practice nurses (APN) interventions; and (b) determine if problems and APN interventions differed by women's medical diagnosis (diabetes, hypertension, preterm labor). Design and Methods: Content analysis of 85 interaction logs created by APNs during a randomized clinical trial in which half of physician-provided prenatal care was substituted with APN-provided prenatal care in the women's homes. Patients' problems and APN interventions were classified with the Omaha Classification System. Findings: A total of 212,835 health problems and 212,835 APN interventions were identified. The dominant antenatal problems were physiologic (59.2%) and health-related behaviors (33.3%); postpartum were physiologic (44.0%) and psychosocial problems (31.6%). Antenatally, women with diabetes had significantly more health-related behavior problems; women with preterm labor had more physiologic problems. APN surveillance interventions predominated antenatally (65.6%) and postpartum (66.0%), followed by health teaching, guidance, and counseling both antenatally (25.4%) and postpartum (28.1%). Women with chronic hypertension required significantly more case-management interventions. Conclusions: The categories of women's problems were largely similar across medical diagnostic groups. Interventions to address women's problems ranged from assessing maternal and fetal physiologic states to teaching interpersonal relationships and self-care management to assisting with transportation and housing. Data show the range of APN knowledge and skills needed to improve maternal and infant outcomes and ultimately reduce healthcare costs in women with high-risk pregnancies. [source] Endothelial, but not the inducible, nitric oxide synthase is detectable in normal and portal hypertensive ratsLIVER INTERNATIONAL, Issue 6 2002Michael Martin Stumm Abstract:Background: Chronic portal hypertension is accompanied by a nitric oxide (NO) dependent vasodilation. Three isoforms of NO producing synthases (NOS) are characterized: neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Sources of increased NO levels in chronic hypertension is disputed. Methods: To determine eNOS and iNOS expression in different organs of portal hypertensive and control rats, we divided Sprague-Dawley rats in 6 groups: (1) Partial portal vein ligated rats, (2) Bile duct ligated rats, (3) Carbon tetrachloride treated rats, (4) Sham operated rats, (5) Untreated control rats, and (6) LPS treated rats. Immunohistochemistry (IHC) and immunoblotting (IB) using antibodies against eNOS or iNOS were carried out on samples from thymus, aorta, heart, lung, oesophagus, liver, spleen, kidney, pancreas, small and large intestine. Results: IHC revealed an even eNOS expression in all groups. Expression of iNOS was restricted to macrophages in organs of LPS treated and the thymus of rats. IB mirrored these results. Conclusion: In chronic portal hypertension, the main source for NO production depends on eNOS activity. [source] Association offirst-trimester low PAPP-A levels with preterm birth,,PRENATAL DIAGNOSIS, Issue 4 2010Katherine R. Goetzinger Abstract Objective To determine the association of, and predictive ability of, pregnancy-associated plasma protein A (PAPP-A), free ,-human chorionic gonadotrophin (,-hCG), and nuchal translucency (NT) with preterm birth (PTB). Methods A 5-year retrospective cohort study of women who underwent first-trimester combined screening was performed. Maternal medical, antepartum, and pregnancy outcome data were obtained. PAPP-A and ,-hCG were converted to multiples of the median (MoM), and primary exposure was defined as ,10th percentile MoM for PAPP-A. Secondary exposures were defined as , 90th percentile MoM for ,-hCG and NT values of , 20 and 25 mm. The primary outcome was PTB before 35 weeks and the secondary outcome was PTB before 32 weeks. Univariate, bivariate, multivariate, and receiver,operator analyses were used. Results Of the 2231 patients meeting inclusion criteria with complete outcome data available, 222 had a PAPP-A level ,10th percentile MoM. Abnormally low PAPP-A was associated with an increased risk for PTB < 35 weeks [adjusted odds ratio (aOR) 2.0, 1.0,3.8] and < 32 weeks (aOR 2.7, 1.1,6.4), even after adjusting for prior PTB, tobacco exposure, chronic hypertension, and body mass index. PAPP-A ,10th percentile was not sufficiently predictive of PTB < 35 weeks (area under curve = 0.63, 95% CI 0.53,0.72). Neither abnormally high ,-hCG nor increased NT was associated with an increased risk for PTB. Conclusions PAPP-A ,10th percentile is associated with an increased risk for PTB, but is not sufficiently predictive to be used clinically. Copyright © 2010 John Wiley & Sons, Ltd. [source] Association of Maternal Chronic Disease and Negative Birth Outcomes in a Non-Hispanic Black-White Mississippi Birth CohortPUBLIC HEALTH NURSING, Issue 4 2007Juanita Graham ABSTRACT Objective: To investigate the impact of selected maternal chronic medical conditions, race, and age on preterm birth (PTB), low birth weight (LBW), and infant mortality among Mississippi mothers from 1999 to 2003. Design: A retrospective cohort analysis of linked birth and death certificates. Sample: The 1999,2003 Mississippi birth cohort comprising 202,931 singleton infants born to African American and White women. Measurements: The relationship between maternal chronic conditions and the dependent variables of PTB, LBW, and infant mortality were investigated using logistic regression analysis. Results: PTB, LBW, and infant mortality were more prevalent among African American women, very young women (,15 years), and women with certain chronic medical conditions. Among White mothers, maternal chronic hypertension was significantly associated with PTB and LBW, and maternal diabetes with PTB and infant mortality. Among African American mothers, maternal cardiac disease was significantly associated with PTB and LBW; maternal chronic hypertension was significantly associated with LBW and infant mortality; and maternal diabetes with PTB. Conclusions: Maternal chronic hypertension and diabetes were significantly associated with negative birth outcomes regardless of maternal race. Maternal cardiac disease was only significantly associated with PTB and LBW among African Americans. [source] Denervation of Carotid Baro- and Chemoreceptors in HumansTHE JOURNAL OF PHYSIOLOGY, Issue 1 2003Henri J. L. M. Timmers Experimental denervation in animals has shown that carotid baro- and chemoreceptors play an eminent role in maintaining blood pressure and blood gas homeostasis. Denervation of carotid sinus baro- and chemoreceptors in humans may occur as a complication of invasive interventions on the neck or after experimental surgical treatment in asthma. In this topical review, the short- and long-term effects of carotid baro- and chemoreceptor denervation on the control of circulation and ventilation in humans are discussed. Carotid baroreceptor denervation in humans causes a persistent decrease in vagal and sympathetic baroreflex sensitivity and an increase in blood pressure variability; however, carotid denervation does not lead to chronic hypertension. Therefore, although carotid baroreceptors contribute to short-term blood pressure control, other receptors are able to maintain normal chronic blood pressure levels in the absence of carotid baroreceptors. Conversely, carotid chemoreceptor denervation leads to permanent abolition of normocapnic ventilatory responses to hypoxia and reduced ventilatory responses to hypercapnia. [source] Hypertension and intra-operative incidents: a multicentre study of 125 000 surgical procedures in Swiss hospitals,ANAESTHESIA, Issue 5 2009K. Beyer Summary It is debated whether chronic hypertension increases the risk of cardiovascular incidents during anaesthesia. We studied all elective surgical operations performed in adults under general or regional anaesthesia between 2000 and 2004, in 24 hospitals collecting computerised clinical data on all anaesthetics since 1996. The focus was on cardiovascular incidents, though other anaesthesia-related incidents were also evaluated. Among 124 939 interventions, 27 881 (22%) were performed in hypertensive patients. At least one cardiovascular incident occurred in 7549 interventions (6% (95% CI 5.9,6.2%)). The average adjusted odds ratio of cardiovascular risk for chronic hypertension was 1.38 (95% CI 1.27,1.49). However, across hospitals, adjusted odd ratios varied from 0.41 up to 2.25. Hypertension did not increase the risk of other incidents. Hypertensive patients are still at risk of intra-operative cardiovascular incidents, while risk heterogeneity across hospitals, despite taking account of casemix and hospital characteristics, suggests variations in anaesthetic practices. [source] Evaluation of chronic hypertension in pregnant young womenAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 3 2009Joana DE SOUSA Women with chronic hypertension are at higher risk of adverse obstetric outcomes. It is essential that the condition is identified and evaluated appropriately in early pregnancy. Therefore, an audit has been carried out to assess how well young pregnant women with chronic hypertension were investigated for secondary cause in South Auckland, compared with the recommendations of the Australasian Society for the Study of Hypertension in Pregnancy. The evaluation of chronic hypertension by history taking, physical examination, laboratory assessment and radiology tests was highly variable. Only 76% of women had appropriate follow-up for their hypertension. Screening for secondary causes was not consistent, and the majority had incomplete investigation. [source] The recurrence risk of severe de novo pre-eclampsia in singleton pregnancies: a population-based cohortBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 12 2009SD McDonald Objective, Previous studies have found recurrence risks of severe pre-eclampsia as high as 40%. Our objective was to determine both the recurrence risk of severe de novo pre-eclampsia and risk factors associated with it in a contemporaneous population. Study design, Population-based retrospective cohort study. Population, Women who had two or more singleton liveborn or stillborn hospital deliveries in Ontario, Canada between April 1994 and March 2002 and without a history of chronic hypertension Methods, International Classification of Disease codes were used to identify patients in the Canadian Institute for Health Information Discharge Abstract Database. Main outcome measures, The absolute and adjusted risks of recurrent severe de novo pre-eclampsia were determined. Results, Between 1 April 1994 and 30 March 2002, there were 185 098 women with two or more singleton deliveries >20 weeks in the province of Ontario, Canada. There were 1954 women who had severe de novo pre-eclampsia in the index pregnancy, 133 of whom had recurrent severe pre-eclampsia, for a risk of recurrent severe pre-eclampsia of 6.8% (95% CI 5.7,7.9%). The risk of recurrent severe de novo pre-eclampsia was increased in women with pre-existing renal disease (adjusted OR 17.98, 95% CI 3.50,92.52) and those >35 years of age (adjusted OR 3.79, 95% CI 2.04,7.04, reference 20,25 years). Conclusions, The recurrence risk of severe de novo pre-eclampsia in our population-based cohort study (6.8%) is lower than previously published reports in selected populations. [source] Acute hypertension reveals depressor and vasodilator effects of cannabinoids in conscious ratsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2009W-S Vanessa Ho Background and purpose:, The cardiovascular effects of cannabinoids can be influenced by anaesthesia and can differ in chronic hypertension, but the extent to which they are influenced by acute hypertension in conscious animals has not been determined. Experimental approach:, We examined cardiovascular responses to intravenous administration of anandamide and the synthetic cannabinoid, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone (WIN55212-2), in conscious male Wistar rats made acutely hypertensive by infusion of angiotensin II (AII) and arginine vasopressin (AVP). Rats were chronically instrumented for measurement of arterial blood pressure and vascular conductances in the renal, mesenteric and hindquarters beds. Key results:, Anandamide dose-dependently decreased the mean arterial blood pressure of rats made hypertensive by AII-AVP infusion, but not normotensive rats. Interestingly, acute hypertension also revealed a hypotensive response to WIN55212-2, which caused hypertension in normotensive animals. The enhanced depressor effects of the cannabinoids in acute hypertension were associated with increased vasodilatation in hindquarters, renal and mesenteric vascular beds. Treatment with URB597, which inhibits anandamide degradation by fatty acid amide hydrolase, potentiated the depressor and mesenteric vasodilator responses to anandamide. Furthermore, haemodynamic responses to WIN55212-2, but not to anandamide, were attenuated by the CB1 receptor antagonist, AM251 [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophen yl)-4-methyl-1H-pyrazole-3-carboxamide]. Conclusions and implications:, These results broadly support the literature showing that the cardiovascular effects of cannabinoids can be exaggerated in hypertension, but highlight the involvement of non-CB1 receptor-mediated mechanisms in the actions of anandamide. [source] | |||||||||||||||||||||||||