991 resultados para positive pressure
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Given the increasing use of ambulatory blood pressure monitoring (ABPM) in both clinical practice and hypertension research, a group of scientists, participating in the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability, in year 2013 published a comprehensive position paper dealing with all aspects of the technique, based on the available scientific evidence for ABPM. The present work represents an updated schematic summary of the most important aspects related to the use of ABPM in daily practice, and is aimed at providing recommendations for proper use of this technique in a clinical setting by both specialists and practicing physicians. The present article details the requirements and the methodological issues to be addressed for using ABPM in clinical practice, The clinical indications for ABPM suggested by the available studies, among which white-coat phenomena, masked hypertension, and nocturnal hypertension, are outlined in detail, and the place of home measurement of blood pressure in relation to ABPM is discussed. The role of ABPM in pharmacological, epidemiological, and clinical research is also briefly mentioned. Finally, the implementation of ABPM in practice is considered in relation to the situation of different countries with regard to the reimbursement and the availability of ABPM in primary care practices, hospital clinics, and pharmacies.
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The occurrence of HTLV-I/II and HIV-1 coinfections have been shown to be frequent, probably in consequence of their similar modes of transmission. This paper presents the prevalence of coinfection of HTLV among HIV-1 infected and AIDS patients in Belém, State of Pará, Brazil. A group of 149 patients attending the AIDS Reference Unit of the State Department of Health was tested for the presence of antibodies to HTLV-I/II using an enzyme immunoassay and the positive reactions were confirmed with a Western blot that discriminates between HTLV-I and HTLV-II infections. Four patients (2.7%) were positive to HTLV-I, seven (4.7%) to HTLV-II and one (0.7%) showed an indeterminate pattern of reaction. The present results show for the first time in Belém not only the occurrence of HTLV-II/HIV-1 coinfections but also a higher prevalence of HTLV-II in relation to HTLV-I. Furthermore, it also enlarges the geographical limits of the endemic area for HTLV-II in the Amazon region of Brazil.
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BACKGROUND: Prediction of clinical course and outcome after severe traumatic brain injury (TBI) is important. OBJECTIVE: To examine whether clinical scales (Glasgow Coma Scale [GCS], Injury Severity Score [ISS], and Acute Physiology and Chronic Health Evaluation II [APACHE II]) or radiographic scales based on admission computed tomography (Marshall and Rotterdam) were associated with intensive care unit (ICU) physiology (intracranial pressure [ICP], brain tissue oxygen tension [PbtO2]), and clinical outcome after severe TBI. METHODS: One hundred one patients (median age, 41.0 years; interquartile range [26-55]) with severe TBI who had ICP and PbtO2 monitoring were identified. The relationship between admission GCS, ISS, APACHE II, Marshall and Rotterdam scores and ICP, PbtO2, and outcome was examined by using mixed-effects models and logistic regression. RESULTS: Median (25%-75% interquartile range) admission GCS and APACHE II without GCS scores were 3.0 (3-7) and 11.0 (8-13), respectively. Marshall and Rotterdam scores were 3.0 (3-5) and 4.0 (4-5). Mean ICP and PbtO2 during the patients' ICU course were 15.5 ± 10.7 mm Hg and 29.9 ± 10.8 mm Hg, respectively. Three-month mortality was 37.6%. Admission GCS was not associated with mortality. APACHE II (P = .003), APACHE-non-GCS (P = .004), Marshall (P < .001), and Rotterdam scores (P < .001) were associated with mortality. No relationship between GCS, ISS, Marshall, or Rotterdam scores and subsequent ICP or PbtO2 was observed. The APACHE II score was inversely associated with median PbtO2 (P = .03) and minimum PbtO2 (P = .008) and had a stronger correlation with amount of time of reduced PbtO2. CONCLUSION: Following severe TBI, factors associated with outcome may not always predict a patient's ICU course and, in particular, intracranial physiology.
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An HIV positive patient presenting a clinical picture of visceral leishmaniasis co-infection was submitted to a bone marrow aspiration after admission to hospital. Amastigotes forms were seen in the bone marrow aspirate and the parasite grew in culture as promastigotes. Molecular analyses showed that the flagellates isolated did not belong to the genera Leishmania, Trypanosoma or Sauroleishmania. It was not possible to establish infection in laboratory animals. In vitro culture of mouse peritoneal macrophages revealed the invasion of the host cells by the flagellates and their killing 48 hr after infection. Opportunistic infection with an insect trypanosomatid was suspected. Further hybridization analyses against a pannel of different monoxenous and heteroxenous trypanosomatids showed kDNA cross-homology with Leptomonas pulexsimulantis a trypanosomatid found in the dog's flea
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OBJECTIVES: This study was designed to identify macrophage-rich atherosclerotic plaque noninvasively by imaging the tissue uptake of long-circulating superparamagnetic nanoparticles with a positive contrast off-resonance imaging sequence (inversion recovery with ON-resonant water suppression [IRON]). BACKGROUND: The sudden rupture of macrophage-rich atherosclerotic plaques can trigger the formation of an occlusive thrombus in coronary vessels, resulting in acute myocardial infarction. Therefore, a noninvasive technique that can identify macrophage-rich plaques and thereby assist with risk stratification of patients with atherosclerosis would be of great potential clinical utility. METHODS: Experiments were conducted on a clinical 3-T magnetic resonance imaging (MRI) scanner in 7 heritable hyperlipidemic and 4 control rabbits. Monocrystalline iron-oxide nanoparticles (MION)-47 were administrated intravenously (2 doses of 250 mumol Fe/kg), and animals underwent serial IRON-MRI before injection of the nanoparticles and serially after 1, 3, and 6 days. RESULTS: After administration of MION-47, a striking signal enhancement was found in areas of plaque only in hyperlipidemic rabbits. The magnitude of enhancement on magnetic resonance images had a high correlation with the number of macrophages determined by histology (p < 0.001) and allowed for the detection of macrophage-rich plaque with high accuracy (area under the curve: 0.92, SE: 0.04, 95% confidence interval: 0.84 to 0.96, p < 0.001). No significant signal enhancement was measured in remote areas without plaque by histology and in control rabbits without atherosclerosis. CONCLUSIONS: Using IRON-MRI in conjunction with superparamagnetic nanoparticles is a promising approach for the noninvasive evaluation of macrophage-rich, vulnerable plaques.
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Hypertension is a serious medical problem affecting millions of people worldwide. A key protein regulating blood pressure is the Epithelial Na(+) Channel (ENaC). In accord, loss of function mutations in ENaC (PHA1) cause hypotension, whereas gain of function mutations (Liddle syndrome) result in hypertension. The region mutated in Liddle syndrome, called the PY motif (L/PPxY), serves as a binding site for the ubiquitin ligase Nedd4-2, a C2-WW-Hect E3 ubiquitin ligase. Nedd4-2 binds the ENaC-PY motif via it WW domains, ubiquitylates the channel and targets it for endocytosis, a process impaired in Liddle syndrome due to poor binding of the channel to Nedd4-2. This leads to accumulation of active channels at the cell surface and increased Na(+) (and fluid) absorption in the distal nephron, resulting in elevated blood volume and blood pressure. Compounds that destabilize cell surface ENaC, or enhance Nedd4-2 activity in the kidney, could potentially serve as drug targets for hypertension. In addition, recent discoveries of regulation of activation of ENaC by proteases such as furin, prostasin and elastase, which cleave the extracellular domain of this channel leading to it activation, as well as the identification of inhibitors that block the activity of these proteases, provide further avenues for drug targeting of ENaC and the control of blood pressure.
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Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.
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A small proportion of the treated hypertensive population consistently has a blood pressure greater than 140/90 mm Hg despite a triple therapy including a diuretic, a calcium channel blocker, and a blocker of the renin-angiotensin system. According to guidelines, these patients have so-called resistant hypertension. The prevalence of this clinical condition is higher in tertiary than primary care centers and often is associated with chronic kidney disease, diabetes, obesity, and sleep apnea syndrome. Exclusion of pseudoresistant hypertension using ambulatory or home blood pressure monitoring is a crucial step in the investigation of patients with resistant hypertension. Thus, among the multiple factors to consider when investigating patients with resistant hypertension, ambulatory blood pressure monitoring should be performed very early. Among other factors to consider, physicians should investigate patient adherence to therapy, assess the adequacy of treatment, exclude interfering factors, and, finally, look for secondary forms of hypertension. Poor adherence to therapy accounts for 30% to 50% of cases of resistance to therapy depending on the methodology used to diagnose adherence problems. This review discusses the clinical factors implicated in the pathogenesis of resistant hypertension with a particular emphasis on pseudoresistance, drug adherence, and the use of ambulatory blood pressure monitoring for the diagnosis and management of resistant hypertension.
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The course of human Leishmania chagasi infections appears to be determined by the balance between type 1 (T1) CD4+ and CD8+ T suppressor (Ts) cell activities. Skin test positive adults living in hyperendemic areas who have no history of visceral leishmaniasis (VL) have T1 CD4+ T cell immunodominant responses against L. chagasi. The cytokines they secrete during anti-leishmania responses are a probable source of cytokines which inhibit the CD8+ Ts cells associated with VL. The ability of supernatants generated from peripheral blood mononuclear cells derived from skin test positive adults to reverse immune responses which appear to be mediated by CD8+ Ts cells was assessed in three sets of screening assays. The supernatants displayed three candidate factors. One, which could be explained by Leishmania antigens in the supernatant, decreased high endogenous IL-10 secretion characteristic of one class of VL patients. A second activity decreased high endogenous proliferation characteristic of the same class of patients without decreasing antigen specific proliferation. The third activity inhibited or killed CD8+ T cells but not CD4+ T cells. These activities might be useful in treating VL.
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BACKGROUND: Pulse wave velocity (PWV), an index of arterial wall stiffness, is modulated by blood pressure (BP). Whether heart rate (HR) is also a modulator of PWV is controversial. Recent research involving mainly patients with high aortic PWV have found either no change or a positive correlation between the two. Given that PWV is increasingly being measured in cardiovascular studies, the relationship between HR and PWV should be known in patients with preserved arterial wall elasticity. OBJECTIVE: The aim of this study was to evaluate the importance of HR as a determinant of the variability in PWV in patients with a low degree of atherosclerosis. DESIGN AND METHODS: Fourteen patients (five female, nine male; aged 68 +/- 8 years) were evaluated post pacemaker implantation due to sick sinus or carotid hypersensitivity syndromes. Carotid-femoral PWV was measured at rest and during atrial pacing at 80, 90 and 100 bpm (paced HR). Arterial femoral blood flow (AFBF) was measured by echodoppler. RESULTS: PWV increased from 6.2 +/- 1.5 m/s (mean +/- SD) during resting sinus rhythm (HR 62 +/- 8 bpm; mean +/- SD) to 6.8 +/- 1.0, 7.0 +/- 0.9, and 7.6 +/- 1.1 m/s at pacing rates of 80, 90 and 100 bpm, respectively (P < 0.0001). Systolic (SBP) and mean blood pressure (MBP) remained constant at all HR levels, whereas AFBF increased in a linear fashion. CONCLUSIONS: These results demonstrate that even in patients with a low degree of atherosclerosis, HR is a potential modulator of carotid-femoral PWV.
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The objective of this study is to determine the different characteristics of human immunodeficiency virus (HIV) positive and negative patients treated for tuberculosis (TBC) in a tertiary hospital in Southern Brazil. We conducted a retrospective cohort study over a 5-year period, from January 1992 through December 1996. We reviewed medical charts of patients from our institution who received TBC treatment. We reviewed 167 medical charts of patients with confirmed TBC. HIV positivity was detected in 74 patients. There were statistically significant difference between HIV positive and negative patients in sex and age. HIV-infected patients showed significantly more signs of bacteremia than HIV-negative patients. Extra-pulmonary TBC was present respectively in 13 (17.6%) and 21 (22.6%) HIV positive and negative patients. There was a significant difference between chest radiograph presentation in HIV positive and negative patients. There were significantly lower hematocrit, hemoglobin, leukocyte and lymphocyte levels in HIV-positive compared to HIV-negative patients. Outcome was significantly different in the two groups with a death rate of 36.5% and 10.8% in HIV-positive and in HIV-negative patients. The difference between HIV positive and negative patients may have importance in the diagnosis, management and prognosis of patients with TBC.
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In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF) sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum samples from individuals without clinical signs associated with Lyme borreliosis were analyzed by IgG Western blot. The results were interpreted following the recommendations of the Centers for Diseases Control and Prevention (CDC) for IgG Western blots. Four samples fulfilled the CDC criteria: two serum specimens from patients with morphea (localized scleroderma), the CSF from the patient with neurologic and arthritic manifestations, and one of the controls. Interpretation of positive serology for Lyme disease in non-endemic countries must be cautious. However these results suggest that the putative "Lyme-like" disease may correlate with positivity on Western blots, thus raising the possibility that a spirochete genospecies distinct from B. burgdorferi sensu stricto, or a Borrelia species other than B. burgdorferi sensu lato is the causative agent. Future work will focus on a survey of the local tick and rodent population for evidence of spirochete species that could be incriminated as the etiologic agent.
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Root diseases caused by fungal pathogens can be suppressed by certain rhizobacteria that effectively colonize the roots and produce extracellular antifungal compounds. To be effective, biocontrol bacteria need to be present at sufficiently high cell densities. These conditions favor the operation of positive feedback mechanisms that control the production of antifungal compounds in biocontrol strains of fluorescent pseudomonads, via both transcriptional and post-transcriptional mechanisms.
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BACKGROUND: Hypertension can be controlled adequately with existing drugs such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Nevertheless, treatment success is often restricted by patients not adhering to treatment. Immunisation against angiotensin II could solve this problem. We investigated the safety and efficacy of CYT006-AngQb-a vaccine based on a virus-like particle-that targets angiotensin II to reduce ambulatory blood pressure. METHODS: In this multicentre, double-blind, randomised, placebo-controlled phase IIa trial, 72 patients with mild-to-moderate hypertension were randomly assigned with a computer-generated randomisation list to receive subcutaneous injections of either 100 mug CYT006-AngQb (n=24), 300 mug CYT006-AngQb (24), or placebo (24), at weeks 0, 4, and 12. 24-h ambulatory blood pressure was measured before treatment and at week 14. The primary outcomes were safety and tolerability. Analyses were done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00500786. FINDINGS: Two patients in the 100 mug group, three in the 300 mug group, and none in the placebo group discontinued study treatment. All patients were included in safety analyses; efficacy analyses did not include the five dropouts, for whom no data were available at week 14. Five serious adverse events were reported (two in the 100 mug group, two in the 300 mug group, and one in the placebo group); none were deemed to be treatment related. Most side-effects were mild, transient reactions at the injection site. Mild, transient influenza-like symptoms were seen in three patients in the 100 mug group, seven in the 300 mug group, and none in the placebo group. In the 300 mug group, there was a reduction from baseline in mean ambulatory daytime blood pressure at week 14 by -9.0/-4.0 mm Hg compared with placebo (p=0.015 for systolic and 0.064 for diastolic). The 300 mug dose reduced the early morning blood-pressure surge compared with placebo (change at 0800 h -25/-13 mm Hg; p<0.0001 for systolic, p=0.0035 for diastolic). INTERPRETATION: Immunisation with CYT006-AngQb was associated with no serious adverse events; most observed adverse events were consistent with local or systemic responses similar to those seen with other vaccines. The 300 mug dose reduced blood pressure in patients with mild-to-moderate hypertension during the daytime, especially in the early morning. FUNDING: Cytos Biotechnology AG.