149 resultados para Critical P Concentration
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OBJECTIVE- To determine whether obesity increases platelet reactivity and thrombin activity in patients with type 2 diabetes plus stable coronary artery disease. RESEARCH DESIGN AND METHODS- We assessed platelet reactivity and markers of thrombin generation and activity in 193 patients from nine clinical sites of the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D). Blood taken at the time of enrollment was used for assay of the concentration of prothrombin fragment 1.2 (PT1.2, released when prothrombin is activated) and fibrinopeptide A (FPA, released when fibrinogen is cleaved). Platelet activation was identified with the use of flow cytometry in response to 0, 0.2, and 1 mu mol/l adenosine diphosphate (ADP). RESULTS- Concentrations of FPA, PT1.2, and platelet activation in the absence of agonist were low. Greater BMI was associated with higher platelet reactivity in response to 1 mu m ADP as assessed by surface expression of P-selectin (r = 0.29, P < 0.0001) but not reflected by the binding of fibrinogen to activated glycoprotein IIb-IIIa. BMI was not associated with concentrations of FPA or PT1.2. Platelet reactivity correlated negatively with A1C (P < 0.04), was not related to the concentration Of triglycerides in blood, and did not correlate with the concentration of C-reactive peptide. CONCLUSIONS- Among patients enrolled in this substudy of BARI 2D, a greater BMI was associated with higher platelet reactivity at the time of enrollment. Our results suggest that obesity and insulin resistance that accompanies obesity may influence platelet reactivity in patients with type 2 diabetes.
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Background: Fibroblast growth factor 23 (FGF23) concentrations increase early in chronic kidney disease (CKD), and the influence of current CKD-mineral and bone disorder (MBD) therapies on serum FGF23 levels is still under investigation. Methods: In this post-hoc analysis of a randomized clinical trial, phosphate binders and calcitriol were washed out of 72 hemodialysis patients who were then submitted to bone biopsy, coronary tomography and biochemical measures, including FGF23. They were randomized to receive sevelamer or calcium acetate for 1 year and the prescription of calcitriol and the calcium concentration in the dialysate were adjusted according to serum calcium, phosphate and PTH and bone biopsy diagnosis. Results: At baseline, bone biopsy showed that 58.3% had low-turnover bone disease, whereas 38.9% had high-turnover bone disease, with no significant differences between them with regard to FGF23. Median baseline FGF23 serum levels were elevated and correlated positively with serum phosphate. After 1 year, serum FGF23 decreased significantly. Repeated measures ANOVA analysis showed that the use of a 3.5-mEq/l calcium concentration in the dialysate, as well as the administration of calcitriol and a calcium-based phosphate binder were associated with higher final serum FGF23 levels. Conclusions: Taken together, our results confirm that the current CKD-MBD therapies have an effect on serum levels of FGF23. Since FGF23 is emerging as a potential treatment target, our findings should be taken into account in the decision on how to manage CKD-MBD therapy. Copyright (C) 2010 S. Karger AG, Basel
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Background: Percutaneous transluminal angioplasty has been used with increasing frequency in the treatment of infrainguinal arterial occlusive disease. This meta-analysis aimed to assess the middle-term outcomes after crural angioplasty in patients with chronic critical limb ischemia and compare results with a meta-analysis of popliteal-to-distal vein bypass graft. Methods: Data were retrieved from 30 articles published from 1990 through 2006 (63% of articles published between 2000 and 2006). All studies used survival analysis, reported a 12-month cumulative rate of patency or limb salvage, and included at least 15 infrapopliteal angioplasties. The outcome measures were immediate technical success, primary and secondary patency, limb salvage, and patient survival. Data from life-tables, survival curves, and texts were used. Results. The pooled estimate of success was 89.0% +/- 2.2% for immediate technical result. Results at 1 and 36 months were 77.4% +/- 4.1% and 48.6% +/- 8.0% for primary patency, 83.3% +/- 1.4% and 62.9% +/- 11.0% for secondary patency, 93.4% +/- 2.3% and 82.4% +/- 3.4% for limb salvage, and 98.3% +/- 0.7% and 68.4% +/- 5.5% for patient survival, respectively. Studies with >75% of the limbs with tissue loss fared worse than their respective comparative subgroup for technical success and patency but not for limb salvage or survival. No publication bias was detected. Conclusion: The technical success and subsequent durability of crural angioplasty are limited compared with bypass surgery, but the clinical benefit is acceptable because limb salvage rates are equivalent to bypass surgery. Further studies are necessary to determine the proper role of infrapopliteal angioplasty.
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This study analyzes the relationship between extracellular purines and pain perception in humans. Cerebrospinal fluid (CSF) levels of purines and their metabolites were compared between patients displaying acute and/or chronic pain syndromes and control subjects. The CSF levels of IMP, inosine, guanosine and uric acid were significantly increased in the chronic pain group and correlated with pain severity (P<0.05). Patients displaying both chronic and acute pain presented similar changes in the CSF purines concentration (P<0.05). However, in the acute pain group, only CSF inosine and uric acid levels were significantly increased (P<0.05). These findings suggest that purines, in special inosine, guanosine and uric acid, are associated with the spinal mechanisms underlying nociception. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
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We evaluated nonreversed vein grafts in above-knee bypasses for chronic critical limb ischemia in a retrospective study with intention-to-treat analysis in patients who underwent above-knee bypass grafting. During a 4-year period, 51 patients (men, 32; women, 19; mean age 66 years) with 53 critically ischemic lower extremities underwent above-knee femoropopliteal bypass grafting. The follow-up evaluation consisted of clinical examination, assessment of the ankle- brachial systolic blood pressure index, and, whenever necessary, duplex scanning. Three ( 5.7%) deaths occurred within 30 days, two from myocardial infarction and one from an undetermined cause. The 2-year cumulative success rate was 82.5 +/- 9.6% for primary patency, 84.6 +/- 8.9% for secondary patency, 90.1 +/- 7.3% for tertiary patency, 86.9 +/- 7.6% for limb salvage, 77.7 +/- 8.4% for survival, 68.0 +/- 11.1% for composite patency, and 68.4 +/- 9.3% for amputation- free survival; the corresponding estimates for vein grafts alone were 86.6 +/- 9.2%, 88.9 +/- 8.6%, 89.0 +/- 8.5%, 88.1 +/- 8.1%, 81.1 +/- 9.1, 76.8 +/- 11.1%, and 72.6 +/- 10.2%. Three prosthetic grafts failed and were replaced with an arm vein graft. Nonreversed vein bypass grafts in above- knee revascularization of critically ischemic limbs are justified.
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The mechanisms that initiate an inflammatory systemic response to a bacterial infection lead to a high mortality and constitute the first cause of death in Critical Care Units (ICU`s). Sepsis is a poorly understood disease and despite life support techniques and the administration of antibiotics, not much more can be done to improve its diagnosis and treatment. The present article has as main objective to discuss the role of neutrophils recruitment in sepsis, dissecting the molecular mechanisms implicated in this complex process and its importance to the pathogenesis of this outstanding cause of death.
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Purpose: Animal models of diseases are extremely important in the study of the physiopathogenesis of human diseases and for testing novel therapeutic interventions. The present study aimed to develop an animal model that simulates human allergic conjunctivitis and to study how allergic response may be influenced by the allergen dose used for immunization and by genetic factors. Methods: Sixty C57Bl/6 mice and 60 BALB/c mice were immunized with placebo, or 5 mu g or 500 mu g of allergen derived from Dermatophagoides pteronyssinus. After ocular challenge, the mice were examined in order to clinically verify the occurrence or not of conjunctivitis. Material obtained from animals was used for total and specific IgE and IgG1 dosage, for assays of Der p-specific lymphocyte proliferation and supernatant cytokine dosage, and for histopathological evaluation of conjunctiva. Results: We developed a murine model of allergic conjunctivitis induced by D. pteronyssinus. The model is similar to human disease both clinically and according to laboratory findings. In mouse, conjunctivitis was associated with a Th2 cytokine profile. However, IL-10 appeared to be involved with disease blockade. Mice of different strains have distinct immune responses, depending on the sensitization dose. Conclusions: The murine model developed is suitable for the study of immunopathogenesis and as a template for future therapies. Using BALB/c and C57BL/6 mice, we demonstrated that genetic factors play a role in determining susceptibility and resistance, as well as in establishing the allergen concentration needed to induce or to block disease development.
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Background: The antiatherogenic functions of high density lipoprotein (HDL-C) include its role in reverse cholesterol transport, but to what extent the concentration of HDL-C interferes with the whole-body cholesterol metabolism is unknown. Therefore, we measured markers of body cholesterol synthesis (desmosterol and lathosterol) and of intestinal cholesterol absorption (campesterol and beta-sitosterol) in healthy subjects that differ according to their plasma HDL-C concentrations. Methods: Healthy participants presented either low HDL-C (<40 mg/dl, n = 33,17 male and 16 female) or high HDL-C (>60 mg/dl, n = 33, 17 male and 16 female), BMI <30 kg/m(2), were paired according to age and gender, without secondary factors that might interfere with their plasma lipid concentrations. Plasma concentrations of non-cholesterol sterols were measured by the combined GC-MS analysis. Results: Plasma desmosterol did not differ between the two groups; however, as compared with the high HDL-C participants, the low HDL-C participants presented higher concentration of lathosterol and lower concentration of the intestinal cholesterol absorption markers campesterol and beta-sitosterol. Conclusion: Plasma concentrations of HDL, and not the activities of LCAT and CETP that regulate the reverse cholesterol transport system, correlate with plasma sterol markers of intestinal cholesterol absorption directly, and of cholesterol synthesis reciprocally. (C) 2010 Elsevier B.V. All rights reserved.
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Objective: To determine the impact of menopause on lipid transfer from donor lipoproteins to high-density lipoproteins (HDLs)-a process that is related to the protective function of HDL-and the size of HDL particles. Method: Plasma from 22 prernenopausal and 18 postmenopausal nonobese, normolipidemic women paired for age (40-50 years) was incubated in an artificial nanoemulsion labeled with radioactive lipids. Then the HDL fraction was assessed for radioactivity; the percentage of radioactive lipids transferred from the nanoemulsion to HDL was determined; and the size of HDL particles was measured by laser light scattering. Results: There were no differences between the 2 groups in serum concentration of HDL cholesterol (61 12 mg/dL vs 61 +/- 14 mg/dL) or apolipoprotein A(1) (1.5 +/- 0.3 g/L vs 1.5 +/- 0.2 g/L); lipid transfer to HDL; or size of HDL particles (8.8 +/- 0.8 vs 9.0 +/- 0.5 nm). Conclusion: Menopause was not found to affect HDL cholesterol plasma concentration, lipid transfer to HDL, or size of HDL particles in normolipidemic nonobese women. (C) 2008 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd.All rights reserved.
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Objectives: To analyze mortality rates of children with severe sepsis and septic shock in relation to time-sensitive fluid resuscitation and treatments received and to define barriers to the implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support guidelines in a pediatric intensive care unit in a developing country. Methods: Retrospective chart review and prospective analysis of septic shock treatment in a pediatric intensive care unit of a tertiary care teaching hospital. Ninety patients with severe sepsis or septic shock admitted between July 2002 and June 2003 were included in this study. Results: Of the 90 patients, 83% had septic shock and 17% had severe sepsis; 80 patients had preexisting severe chronic diseases. Patients with septic shock who received less than a 20-mL/kg dose of resuscitation fluid in the first hour of treatment had a mortality rate of 73%, whereas patients who received more than a 40-mL/kg dose in the first hour of treatment had a mortality rate of 33% (P < 0.05.) Patients treated less than 30 minutes after diagnosis of severe sepsis and septic shock had a significantly lower mortality rate (40%) than patients treated more than 60 Minutes after diagnosis (P < 0.05). Controlling for the risk of mortality, early fluid resuscitation was associated with a 3-fold reduction in the odds of death (odds ratio, 0.33; 95% confidence interval, 0.13-0.85). The most important barriers to achieve adequate severe sepsis and septic shock treatment were lack of adequate vascular access, lack of recognition of early shock, shortage of health care providers, and nonuse of goals and treatment protocols. Conclusions: The mortality rate was higher for children older than years, for those who received less than 40 mL/kg in the first hour, and for those whose treatment was not initiated in the first 30 Minutes after the diagnosis of septic shock. The acknowledgment of existing barriers to a timely fluid administration and the establishment of objectives to overcome these barriers may lead to a more successful implementation of the American College of Critical Care Medicine guidelines and reduced mortality rates for children with septic shock in the developing world.
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Background Primary Immunodeficiencies (PIDs) represent unique opportunities to understand the operation of the human immune system. Accordingly, PIDs associated with autoimmune manifestations provide insights into the pathophysiology of autoimmunity as well as into the genetics of autoimmune diseases (AID). Epidemiological data show that there are PIDs systematically associated with AID, such as immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX), Omenn syndrome, autoinunune polyendocrinopathy-candidiasis-ectodertnal dystrophy (APECED), autoinumine lymphoproliferative syndrome (ALPS), and C1q deficiency, while strong associations are seen with a handful of other deficits. Conclusion We interpret such stringent disease associations, together with a wealth of observations in experimental systems, as indicating first of all that natural tolerance to body components is an active, dominant process involving many of the components that ensure responsiveness, rather than, as previously believed, the result of the mere purge of autoreactivities. More precisely, it seems that deficits of Treg cell development, functions, numbers, and T cell receptor repertoire are among the main factors for autoimmunity pathogenesis in many (if not all) PIDs most frequently presenting with autoimmune features. Clearly, other pathophysiological mechanisms are also involved in autoimmunity, but these seem less critical in the process of self-tolerance. Comparing the clinical picture of IPEX cases with those, much less severe, of ALPS or APECED, provides some assessment of the relative importance of each set of mechanisms.
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Background: Biochemical analysis of fluid is the primary laboratory approach hi pleural effusion diagnosis. Standardization of the steps between collection and laboratorial analyses are fundamental to maintain the quality of the results. We evaluated the influence of temperature and storage time on sample stability. Methods: Pleural fluid from 30 patients was submitted to analyses of proteins, albumin, lactic dehydrogenase (LDH), cholesterol, triglycerides, and glucose. Aliquots were stored at 21 degrees, 4 degrees, and-20 degrees C, and concentrations were determined after 1, 2, 3, 4, 7, and 14 days. LDH isoenzymes were quantified in 7 random samples. Results: Due to the instability of isoenzymes 4 and 5, a decrease in LDH was observed in the first 24 h in samples maintained at -20 degrees C and after 2 days when maintained at 4 degrees C. Aside from glucose, all parameters were stable for up to at least day 4 when stored at room temperature or 4 degrees C. Conclusions: Temperature and storage time are potential preanalytical errors in pleural fluid analyses, mainly if we consider the instability of glucose and LDH. The ideal procedure is to execute all the tests immediately after collection. However, most of the tests can be done in refrigerated sample;, excepting LDH analysis. (C) 2010 Elsevier B.V. All rights reserved.
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Photodynamic therapy requires a photosensitizer, oxygen, and activating light. For acne, pilosebaceous units are ""target"" structures. Porphyrins are synthesized in vivo from 5-aminolevulinic acid (ALA), particularly in pilosebaceous units. Different photosensitizers and drug delivery methods have been reported for acne treatment. There are a variety of porphyrin precursors with different pharmacokinetic properties. Among them, ALA and methyl-ester of ALA (MAT.) are available for possible off-label treatment of acne vulgaris. In addition, various light sources, light dosimetry, drug incubation time, and pre- and posttreatment care also change efficacy and side effects. None of these variables has been optimized for acne treatment, but a number of clinical trials provide helpful guidance. In this paper, we critically analyze clinical trials, case reports, and series of cases published through 2009. (J Am Acad Dermatol 2010;63:195-211.)
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Rearrangements of 1p36 are the most frequently detected abnormalities in diagnostic testing for chromosomal cryptic imbalances and include variably sized simple terminal deletions, derivative chromosomes, interstitial deletions, and complex rearrangements. These rearrangements result in the specific pattern of malformation and neurodevelopmental disabilities that characterizes monosomy 1p36 syndrome. Thus far, no individual gene within this region has been conclusively determined to be causative of any component of the phenotype. Nor is it known if the rearrangements convey phenotypes via a haploinsufficiency mechanism or through a position effect. We have used multiplex ligation-dependent probe amplification to screen for deletions of 1p36 in a group of 154 hyperphagic and overweight/obese, PWS negative individuals, and in a separate group of 83 patients initially sent to investigate a variety of other conditions. The strategy allowed the identification and delineation of rearrangements in nine subjects with a wide spectrum of clinical presentations. Our work reinforces the association of monosomy 1p36 and obesity and hyperphagia, and further suggests that these features may be associated with non-classical manifestations of this disorder in addition to a submicroscopic deletion of similar to 2-3 Mb in size. Multiplex ligation probe amplification using the monosomy 1p36 syndrome-specific kit coupled to the subtelomeric kit is an effective approach to identify and delineate rearrangements at 1p36. (C) 2009 Wiley-Liss, Inc.
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Studies that have investigated ascorbic acid (AA) concentrations in cord blood have pointed to significant associations with maternal blood AA concentrations. smoking, age, diet, type of delivery, duration of gestation, fetal distress and birth weight. The aim of the present study was to determine the relationship between cord blood AA concentrations in newborns and maternal characteristics. A total of 117 Brazilian healthy parturients were included in this cross-sectional study. The concentrations of AA in blood were determined by the HPLC method. Data concerning socio-economic, demographic, obstetric, nutritional and health characteristics of the parturients, including alcohol consumption and smoking habit, were assessed by a standardised questionnaire. A FFQ was used to investigate the intake of foods rich in vitamin C. Cord blood AA concentration was significantly correlated with per capita income (r 0.26; P=0.005), maternal blood AA concentration (r 0.48; P<0.001) and maternal vitamin C-rich food intake score (r 0.36; P<0.001). The linear regression model including maternal AA concentration, alcohol consumption, smoking, parity, vitamin C-rich food intake score and per capita income explained 31.13% of the variation in cord blood AA concentrations in newborns. We recommend further experimental studies to assess the effects of ethanol on placental AA uptake, and epidemiological cohort studies to evaluate in detail the influence of maternal alcohol consumption on cord blood AA concentrations.