951 resultados para unavoidable type ii error
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Protrusion of the intervertebral disc can cause chronic progressive compression of the spinal cord, and the neurological associated signs vary according to anatomical location, duration and dynamic force of compression. The type II disc disease is not fully understood, and there are many controversies about is clinical significance and best form of treatment. The most important aspect of conservative treatment is rest and physiotherapy associated with mild exercise, and use of corticosteroids to reduce vasogenic edema. The spinal decompression by surgery for removal of disc material from within the medullary canal is the surgical treatment of choice in type I disc disease, but has technical limitations in the type II disc disease. The purpose of this paper is to review the pathophysiology and treatment of chronic intervertebral disc disease and discuss the controversies in medical treatment and the use of some traditional and new surgical techniques.
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Pós-graduação em Microbiologia Agropecuária - FCAV
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Evaluations of measurement invariance provide essential construct validity evidence. However, the quality of such evidence is partly dependent upon the validity of the resulting statistical conclusions. The presence of Type I or Type II errors can render measurement invariance conclusions meaningless. The purpose of this study was to determine the effects of categorization and censoring on the behavior of the chi-square/likelihood ratio test statistic and two alternative fit indices (CFI and RMSEA) under the context of evaluating measurement invariance. Monte Carlo simulation was used to examine Type I error and power rates for the (a) overall test statistic/fit indices, and (b) change in test statistic/fit indices. Data were generated according to a multiple-group single-factor CFA model across 40 conditions that varied by sample size, strength of item factor loadings, and categorization thresholds. Seven different combinations of model estimators (ML, Yuan-Bentler scaled ML, and WLSMV) and specified measurement scales (continuous, censored, and categorical) were used to analyze each of the simulation conditions. As hypothesized, non-normality increased Type I error rates for the continuous scale of measurement and did not affect error rates for the categorical scale of measurement. Maximum likelihood estimation combined with a categorical scale of measurement resulted in more correct statistical conclusions than the other analysis combinations. For the continuous and censored scales of measurement, the Yuan-Bentler scaled ML resulted in more correct conclusions than normal-theory ML. The censored measurement scale did not offer any advantages over the continuous measurement scale. Comparing across fit statistics and indices, the chi-square-based test statistics were preferred over the alternative fit indices, and ΔRMSEA was preferred over ΔCFI. Results from this study should be used to inform the modeling decisions of applied researchers. However, no single analysis combination can be recommended for all situations. Therefore, it is essential that researchers consider the context and purpose of their analyses.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Carnosine is present in high concentrations in skeletal muscle where it contributes to acid buffering and functions also as a natural protector against oxidative and carbonyl stress. Animal studies have shown an anti-diabetic effect of carnosine supplementation. High carnosinase activity, the carnosine degrading enzyme in serum, is a risk factor for diabetic complications in humans. The aim of the present study was to compare the muscle carnosine concentration in diabetic subjects to the level in non-diabetics. Type 1 and 2 diabetic patients and matched healthy controls (total n = 58) were included in the study. Muscle carnosine content was evaluated by proton magnetic resonance spectroscopy (3 Tesla) in soleus and gastrocnemius. Significantly lower carnosine content (-45%) in gastrocnemius muscle, but not in soleus, was shown in type 2 diabetic patients compared with controls. No differences were observed in type 1 diabetic patients. Type II diabetic patients display a reduced muscular carnosine content. A reduction in muscle carnosine concentration may be partially associated with defective mechanisms against oxidative, glycative and carbonyl stress in muscle.
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In the paper of Bonora et al. (2008) [3] we have shown, in the context of type II superstring theory, the classification of the allowed B-field and A-field configurations in the presence of anomaly-free D-branes, the mathematical framework being provided by the geometry of gerbes. Here we complete the discussion considering in detail the case of a stack of D-branes, carrying a non-abelian gauge theory, which was just sketched in Bonora et al. (2008) [3]. In this case we have to mix the geometry of abelian gerbes, describing the B-field, with the one of higher-rank bundles, ordinary or twisted. We describe in detail the various cases that arise according to such a classification, as we did for a single D-brane, showing under which hypotheses the A-field turns out to be a connection on a canonical gauge bundle. We also generalize to the non-abelian setting the discussion about "gauge bundles with non-integral Chern classes", relating them to twisted bundles with connection. Finally, we analyze the geometrical nature of the Wilson loop for each kind of gauge theory on a D-brane or stack of D-branes.
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BACKGROUND: Ghrelin is a gastrointestinal peptide hormone (a 28-amino acid peptide) produced primarily by X/A cells in the oxyntic glands of the stomach fundus and cells lining the duodenum cavern. It suppresses insulin secretion and action and commands a significant role in regulating food intake. The aim of the present study was to show that modified laparoscopic sleeve gastrectomy (MLSG), in which a significant part of the gastric fundus and body of the stomach is removed up to 1 inch from the pylorus vein, may contribute to decreasing circulating ghrelin levels. METHODS: A study population consisting of 150 individuals was monitored after undergoing a MLSG, with individuals chosen based on a documented history of diabetes mellitus type 2 and metabolic syndrome, clinical results determining a body mass index (BMI) of 35 to 60 kg/m(2), peptide C level greater than 1, negative anti-glutamic acid decarboxylase, negative anti-insulin, and confirmed stability of drug/insulin treatment and glycosylated hemoglobin greater than 6.5% for at least 24 and 3 months, respectively, before enrollment. RESULTS: Twenty-four months after surgery, 150 patients (86.6%) presented with normal glycemic levels between 77 and 99 mg/dL. All patients improved average serum insulin levels by 9 mU/L and average glycosylated hemoglobin levels by 5.1% (normal range, 4%-6%). All patients tested negative for Helicobacter pylori and stopped using insulin, with 3 patients prescribed twice-daily use of an oral hypoglycemiant. In 14% of cases, patients experienced partial hair loss with low serum zinc levels and were prescribed oral zinc reposition and topical hair stimulants. The average weight loss recorded was 44.6% for patients with a BMI less than 45 kg/m(2) and 58% for patients with a BMI greater than 50 kg/m(2). CONCLUSIONS: The MLSG is a safe procedure with a low morbidity rate (2.7%) (4 cases of fistula and 2 of bleeding) and no surgical mortality in this study. This surgery can promote control of diabetes mellitus type 2 and aid the treatment of exogenous overweight and morbidly obese individuals. The results of this study show that only through resection of the ghrelin-producing gastric area can most obesity cases and diabetes type II conditions be reverted to nonobese and controlled diabetes. (c) 2012 Elsevier Inc. All rights reserved.
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Staphylococcus aureus TenA (SaTenA) is a thiaminase type II enzyme that catalyzes the deamination of aminopyrimidine, as well as the cleavage of thiamine into 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) and 5-(2-hydroxyethyl)-4-methylthiazole (THZ), within thiamine (vitamin B1) metabolism. Further, by analogy with studies of Bacillus subtilis TenA, SaTenA may act as a regulator controlling the secretion of extracellular proteases such as the subtilisin type of enzymes in bacteria. Thiamine biosynthesis has been identified as a potential drug target of the multi-resistant pathogen S. aureus and therefore all enzymes involved in the S. aureus thiamine pathway are presently being investigated in detail. Here, the structure of SaTenA, determined by molecular replacement and refined at 2.7 A ° resolution to an R factor of 21.6% with one homotetramer in the asymmetric unit in the orthorhombic space group P212121, is presented. The tetrameric state of wild-type (WT) SaTenA was postulated to be the functional biological unit and was confirmed by small-angle X-ray scattering (SAXS) experiments in solution. To obtain insights into structural and functional features of the oligomeric SaTenA, comparative kinetic investigations as well as experiments analyzing the structural stability of the WT SaTenA tetramer versus a monomeric SaTenA mutant were performed.
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Covalent grafting mesogenic groups to the coordination cores of the parent mononuclear low-spin and spin-crossover compounds afforded metallomesogenic complexes of iron(II). In comparison with the parent complexes the spin-crossover properties of the alkylated derivatives are substantially modified. The type of the modification was found to be dependent on the properties of the parent system and the nature of the used anion, however, the general tendency is the destabilization of the low-spin state at the favor of spin-crossover or high-spin behavior below 400 K. The structural insight revealed the micro-segregated layered organization. The effect of the alkylation of the parent compounds consists first of all in the change of the lattice to a two-dimensional lamellar one retaining significant intermolecular contacts only within the ionic bilayers. The comprehensive analysis of the structural and thermodynamic data in the homologous series pointed at the mechanism of the interplay between the structural modification on melting and the induced anomalous change of the magnetic properties. A family of one-dimensional spin-crossover polymers was synthesized and characterized using a series of spectroscopic methods, X-ray powder diffraction, magnetic susceptibility measurements and differential scanning calorimetry. The copper analogue of was also synthesized and its crystal structure solved. In comparison with the mononuclear systems, the polymeric mesogens of iron(II) are less sensitive to the glass transition, which was attributed to the moderate concomitant variation of the structure. Nevertheless, the observed increase of the magnetic hysteresis with lengthening of the alkyl substituents was ascribed to the interplay of the structural reorganization of the coordination core due to spin-crossover with the structural delay in the spatial reorganization of the mesogenic substituents. The classification of mononuclear and polymeric metallomesogens according to the interactions between the structural- and the spin-transition and analysis of the data on the reported spin-crossover metallomesogens led to the separation of three types, namely: Type i: systems with coupling between the electronic structure of the iron(II) ions and the mesomorphic behavior of the substance; Type ii: systems where both transitions coexist in the same temperature region but are not coupled due to competition with the dehydration or due to negligible structural transformation; Type iii: systems where both transitions occur in different temperature regions and therefore are uncoupled. Fine-tuning, in particular regarding the temperature at which the spin-transition occurs with hysteresis properties responsible for the memory effect, are still a major challenge towards practical implementation of spin-crossover materials. A possible answer to the problem could be materials in which the spin-crossover transition is coupled with another transition easily controllable by external stimuli. In the present thesis we have shown the viability of the approach realized in the mesogenic systems with coupled phase- and spin-transitions.
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Adult-type Pompe's disease (glycogen storage disease type II) has rarely been shown to present with dilatative arteriopathy, suggesting potential smooth muscle involvement in addition to lysosomal glycogen deposits usually restricted to skeletal muscle tissue. We report the case of a middle-aged man under enzyme replacement therapy presenting with an exceedingly large thoracic aortic aneurysm. Surprisingly, the histological work-up of resected aortic tissue revealed changes mimicking those observed in patients with classic connective tissue diseases. Enzyme replacement therapy, in addition to musculoskeletal and pulmonary treatment for patients with Pompe's disease, may prolong survival and lead to patients presenting with vascular alterations that may pose surgical and potential diagnostic challenges in the future.
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Macrophage-mediated chronic inflammation is mechanistically linked to insulin resistance and atherosclerosis. Although arginase I is considered antiinflammatory, the role of arginase II (Arg-II) in macrophage function remains elusive. This study characterizes the role of Arg-II in macrophage inflammatory responses and its impact on obesity-linked type II diabetes mellitus and atherosclerosis.
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1.--The immunomodulating agent FTY720 is a substrate for the sphingosine kinase and the phosphorylated form is able to bind to sphingosine 1-phosphate (S1P) receptors. In this study, we show that exposure of renal mesangial cells to phospho-FTY720 leads to a rapid and transient activation of several protein kinase cascades, including the mitogen- and stress-activated protein kinases. The nonphosphorylated FTY720 also increased MAPK phosphorylation, but with a reduced potency and a more delayed time course. In addition, phospho-FTY720 and FTY720 are able to increase phosphorylation of Smad proteins which are classical members of the transforming growth factor-beta (TGF-beta) signalling device, thus suggesting a crosstalk between FTY720 and TGF-beta signalling. 2.--Pretreatment with the S1P(3) receptor antagonist suramin inhibits FTY720 and phospho-FTY720-induced Smad phosphorylation, whereas pertussis toxin pretreatment, which blocks G(i/0) proteins, has no effect on Smad phosphorylation. 3.--Since TGF-beta is a potent profibrotic cytokine in mesangial cells and upregulates the connective tissue growth factor (CTGF) and collagen as important hallmarks in the fibrotic sequelae, we investigated whether FTY720 and phospho-FTY720 are able to mimic these effects of TGF-beta. Indeed, FTY720 and phospho-FTY720 markedly upregulate CTGF and collagen type IV protein expressions. In addition, the tissue inhibitor of metalloproteinase-1 is transcriptionally activated by FTY720, whereas cytokine-induced matrix metalloproteinase-9 is down-regulated by FTY720. 4.--Depletion of the TGF-beta receptor type II by the siRNA transfection technique blocks not only Smad phosphorylation but also CTGF upregulation. Similarly, Smad-4 depletion by siRNA transfection also abrogates CTGF upregulation induced by FTY720 and phospho-FTY720. 5.--In summary, our data show that FTY720 and phospho-FTY720 not only activate the Smad signalling cascade in mesangial cells, but also upregulate the expression of CTGF and collagen. These findings suggest that FTY720 may have additional effects besides the established immunomodulatory action and, importantly, a profibrotic activity has to be considered in future experimental approaches.
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CONTEXT: The effect of a percutaneous coronary intervention (PCI) on the long-term prognosis of patients with silent ischemia after a myocardial infarction (MI) is not known. OBJECTIVE: To determine whether PCI compared with drug therapy improves long-term outcome of asymptomatic patients with silent ischemia after an MI. DESIGN, SETTING, AND PARTICIPANTS: Randomized, unblinded, controlled trial (Swiss Interventional Study on Silent Ischemia Type II [SWISSI II]) conducted from May 2, 1991, to February 25, 1997, at 3 public hospitals in Switzerland of 201 patients with a recent MI, silent myocardial ischemia verified by stress imaging, and 1- or 2-vessel coronary artery disease. Follow-up ended on May 23, 2006. INTERVENTIONS: Percutaneous coronary intervention aimed at full revascularization (n = 96) or intensive anti-ischemic drug therapy (n = 105). All patients received 100 mg/d of aspirin and a statin. MAIN OUTCOME MEASURES: Survival free of major adverse cardiac events defined as cardiac death, nonfatal MI, and/or symptom-driven revascularization. Secondary measures included exercise-induced ischemia and resting left ventricular ejection fraction during follow-up. RESULTS: During a mean (SD) follow-up of 10.2 (2.6) years, 27 major adverse cardiac events occurred in the PCI group and 67 events occurred in the anti-ischemic drug therapy group (adjusted hazard ratio, 0.33; 95% confidence interval, 0.20-0.55; P<.001), which corresponds to an absolute event reduction of 6.3% per year (95% confidence interval, 3.7%-8.9%; P<.001). Patients in the PCI group had lower rates of ischemia (11.6% vs 28.9% in patients in the drug therapy group at final follow-up; P = .03) despite fewer drugs. Left ventricular ejection fraction remained preserved in PCI patients (mean [SD] of 53.9% [9.9%] at baseline to 55.6% [8.1%] at final follow-up) and decreased significantly (P<.001) in drug therapy patients (mean [SD] of 59.7% [11.8%] at baseline to 48.8% [7.9%] at final follow-up). CONCLUSION: Among patients with recent MI, silent myocardial ischemia verified by stress imaging, and 1- or 2-vessel coronary artery disease, PCI compared with anti-ischemic drug therapy reduced the long-term risk of major cardiac events. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00387231.