988 resultados para plant organization level
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Context: Although numerous studies have examined the role of latent variables in the structure of comorbidity among mental disorders, none has examined their role in the development of comorbidity. Objective: To study the role of latent variables in the development of comorbidity among 18 lifetime DSM-IV disorders in the World Health Organization World Mental Health Surveys. Design: Nationally or regionally representative community surveys. Setting: Fourteen countries. Participants: A total of 21 229 survey respondents. Main Outcome Measures: First onset of 18 lifetime DSM-IV anxiety, mood, behavior, and substance disorders assessed retrospectively in the World Health Organization Composite International Diagnostic Interview. Results: Separate internalizing (anxiety and mood disorders) and externalizing (behavior and substance disorders) factors were found in exploratory factor analysis of lifetime disorders. Consistently significant positive time-lagged associations were found in survival analyses for virtually all temporally primary lifetime disorders predicting subsequent onset of other disorders. Within-domain (ie, internalizing or externalizing) associations were generally stronger than between-domain associations. Most time-lagged associations were explained by a model that assumed the existence of mediating latent internalizing and externalizing variables. Specific phobia and obsessive-compulsive disorder (internalizing) and hyperactivity and oppositional defiant disorders (externalizing) were the most important predictors. A small number of residual associations remained significant after controlling the latent variables. Conclusions: The good fit of the latent variable model suggests that common causal pathways account for most of the comorbidity among the disorders considered herein. These common pathways should be the focus of future research on the development of comorbidity, although several important pairwise associations that cannot be accounted for by latent variables also exist that warrant further focused study.
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Objective: Although suicide is a leading cause of death worldwide, clinicians and researchers lack a data-driven method to assess the risk of suicide attempts. This study reports the results of an analysis of a large cross-national epidemiologic survey database that estimates the 12-month prevalence of suicidal behaviors, identifies risk factors for suicide attempts, and combines these factors to create a risk index for 12-month suicide attempts separately for developed and developing countries. Method: Data come from the World Health Organization (WHO) World Mental Health (WMH) Surveys (conducted 2001-2007), in which 108,705 adults from 21 countries were interviewed using the WHO Composite International Diagnostic Interview. The survey assessed suicidal behaviors and potential risk factors across multiple domains, including socio-demographic characteristics, parent psychopathology, childhood adversities, DSM-IV disorders, and history of suicidal behavior. Results: Twelve-month prevalence estimates of suicide ideation, plans, and attempts are 2.0%, 0.6%, and 0.3%, respectively, for developed countries and 2.1%, 0.7%, and 0.4%, respectively, for developing countries. Risk factors for suicidal behaviors in both developed and developing countries include female sex, younger age, lower education and income, unmarried status, unemployment, parent psychopathology, childhood adversities, and presence of diverse 12-month DSM-IV mental disorders. Combining risk factors from multiple domains produced risk indices that accurately predicted 12-month suicide attempts in both developed and developing countries (area under the receiver operating characteristic curve = 0.74-0.80). Conclusions: Suicidal behaviors occur at similar rates in both developed and developing countries. Risk indices assessing multiple domains can predict suicide attempts with fairly good accuracy and may be useful in aiding clinicians in the prediction of these behaviors. J Clin Psychiatry 2010;71(12):1617-1628 (C) Copyright 2010 Physicians Postgraduate Press, Inc.
Linking biophysical and genetic models to integrate physiology, molecular biology and plant breeding
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PURPOSE: To analyze the effects of variations in femtosecond laser energy level on corneal stromal cell death. and inflammatory cell influx following flap creation in a rabbit model. METHODS: Eighteen rabbits were stratified in three different groups according to level of energy applied for flap creation (six animals per group). Three different energy levels were chosen for both the lamellar and side cut; 2.7 mu J (high energy), 1.6 mu J (intermediate energy), and 0.5 mu J (low energy) with a 60 kHz, model II, femtosecond laser (IntraLase). The opposite eye of each rabbit served as a control. At the 24-hour time point after surgery, all rabbits were euthanized and the comeoscleral rims were analyzed for the levels of cell death and inflammatory cell influx with the terminal uridine deoxynucleotidyl transferase dUTP-nick end labeling (TUNEL) assay and immunocytochemistry for monocyte marker CD11b, respectively. RESULTS: The high energy group (31.9 +/- 7.1 [standard error of mean (SEM) 2.9]) had significantly more TUNEL positive cells in the central flap compared to the intermediate (22.2 +/- 1.9 [SEM 0.8], P=.004), low (17.9 +/- 4.0 [SEM 1.6], P <= .001), and control eye (0.06 +/- 0.02 [SEM 0.009], P <= .001) groups. The intermediate and low energy groups also had significantly more TUNEL positive cells than the control groups (P <= .001). The difference between the intermediate and low energy levels was not significant (P=.56). The mean for CD11b-positive cells/400x field at the flap edge was 26.1 +/- 29.3 (SEM 11.9), 5.8 +/- 4.1 (SEM 1.6), 1.6 +/- 4.1 (SEM 1.6), and 0.005 +/- 0.01 (SEM 0.005) for high energy, intermediate energy, low energy, and control groups, respectively. Only the intermediate energy group showed statistically more inflammatory cells than control eyes (P = .015), most likely due to variability between eyes. CONCLUSIONS: Higher energy levels trigger greater cell death when the femtosecond laser is used to create corneal flaps: Greater corneal inflammatory cell infiltration is observed with higher femtosecond laser energy levels. [J Refract Surg. 2009;25:869-874.] doi:10.3928/1081597X-20090917-08
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Background/Aims: Abnormal inflammatory response has been associated to the pathogenesis of Alzheimer`s disease (AD) and may be a marker of an ongoing neurodegenerative process. The aim of this study was to evaluate the serum levels of interleukin-1 beta (IL-1 beta) in patients with mild cognitive impairment (MCI) and AD. Methods: One hundred and sixty-three older adults ( 58 with mild to moderate AD, 74 with MCI and 31 healthy controls) were recruited for this study. Serum IL-1 beta levels were measured by ELISA. Patients with MCI were subcategorized in single-domain amnestic (aMCI), nonamnestic (naMCI), and multiple-domain (mdMCI) subtypes. Results: Patients with AD and MCI ( all subtypes) had a significant increase in serum IL-1 beta levels as compared to controls (p = 0.03). Patients with mdMCI had serum IL-1 beta levels comparable to those with AD, and significantly higher than those observed in aMCI and naMCI ( p = 0.02). Discussion: The present study provides evidence that inflammatory mechanisms, represented by elevated IL-1 beta, are observed in patients with MCI, specifically in those with impairment in multiple cognitive domains. As these patients are at higher risk of conversion to dementia, we propose that an increased serum IL-1 beta level is a stage marker of the ongoing brain neurodegeneration in the continuum between normal ageing and AD. Copyright (C) 2009 S. Karger AG, Basel
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Objective: To compare the triggering performance of mid-level ICU mechanical ventilators with a standard ICU mechanical ventilator. Design: Experimental bench study. Setting: The respiratory care laboratory of a university-affiliated teaching hospital. Subject: A computerized mechanical lung model, the IngMar ASL5000. Interventions: Ten mid-level ICU ventilators were compared to an ICU ventilator at two levels of lung model effort, three combinations of respiratory mechanics (normal, COPD and ARDS) and two modes of ventilation, volume and pressure assist/control. A total of 12 conditions were compared. Measurements and main results: Performance varied widely among ventilators. Mean inspiratory trigger time was < 100 ms for only half of the tested ventilators. The mean inspiratory delay time (time from initiation of the breath to return of airway pressure to baseline) was longer than that for the ICU ventilator for all tested ventilators except one. The pressure drop during triggering (Ptrig) was comparable with that of the ICU ventilator for only two ventilators. Expiratory Settling Time (time for pressure to return to baseline) had the greatest variability among ventilators. Conclusions: Triggering differences among these mid-level ICU ventilators and with the ICU ventilator were identified. Some of these ventilators had a much poorer triggering response with high inspiratory effort than the ICU ventilator. These ventilators do not perform as well as ICU ventilators in patients with high ventilatory demand.
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Recent studies have investigated whether low level laser therapy (LLLT) can optimize human muscle performance in physical exercise. This study tested the effect of LLLT on muscle performance in physical strength training in humans compared with strength training only. The study involved 36 men (20.8 +/- 2.2 years old), clinically healthy, with a beginner and/or moderate physical activity training pattern. The subjects were randomly distributed into three groups: TLG (training with LLLT), TG (training only) and CG (control). The training for TG and TLG subjects involved the leg-press exercise with a load equal to 80% of one repetition maximum (1RM) in the leg-press test over 12 consecutive weeks. The LLLT was applied to the quadriceps muscle of both lower limbs of the TLG subjects immediately after the end of each training session. Using an infrared laser device (808 nm) with six diodes of 60 mW each a total energy of 50.4 J of LLLT was administered over 140 s. Muscle strength was assessed using the 1RM leg-press test and the isokinetic dynamometer test. The muscle volume of the thigh of the dominant limb was assessed by thigh perimetry. The TLG subjects showed an increase of 55% in the 1RM leg-press test, which was significantly higher than the increases in the TG subjects (26%, P = 0.033) and in the CG subjects (0.27%, P < 0.001). The TLG was the only group to show an increase in muscle performance in the isokinetic dynamometry test compared with baseline. The increases in thigh perimeter in the TLG subjects and TG subjects were not significantly different (4.52% and 2.75%, respectively; P = 0.775). Strength training associated with LLLT can increase muscle performance compared with strength training only.
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This study assessed the occurrence of human rhinovirus (HRV) species in outpatient children attending day-care in Sao Paulo, Brazil. HRV reverse transcriptase polymerase chain reaction and amplicon sequencing were done in 120 samples collected in 2008. HRV was detected in 27.5% of samples. HRV C was detected in 60.7% of wheezers, a frequency not different from that observed in nonwheezers (69.6%).
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Gangliosides are known to be important in many biological processes. However, details concerning the exact function of these glycosphingolipids in cell physiology are poorly understood. in this study, the role of gangliosides present on the surface of rodent mast cells in maintaining cell structure was examined using RBL-2H3 mast cells and two mutant cell lines (E5 and D1) deficient in the gangliosides, GM(1) and the alpha-galactosyl derivatives of the ganglioside GD(1b). The two deficient cell lines were morphologically different from each other as well as from the parental RBL-2H3 cells. Actin filaments in RBL-2H3 and E5 cells were under the plasma membrane following the spindle shape of the cells, whereas in D1 cells, they were concentrated in large membrane ruffles. Microtubules in RBL-2H3 and E5 cells radiated from the centrosome and were organized into long, straight bundles. The bundles in D1 cells were thicker and organized circumferentially under the plasma membrane. The endoplasmic reticulum, the Golgi complex, and the secretory granule matrix were also altered in the mutant cell lines. These results suggest that the mast cell-specific alpha-galactosyl derivatives of ganglioside GD(1b) and GM(1) are important in maintaining normal cell morphology. (J Histochern Cytochem 58:83-93, 2010)
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Hemophilia B is a genetic disease of the coagulation system that affects one in 30,000 males worldwide. Recombinant human Factor IX (rhFIX) has been used for hemophilia B treatment, but the amount of active protein generated by these systems is inefficient, resulting in a high-cost production of rhFIX. In this study, we developed an alternative for rhFIX production. We used a retrovirus system to obtain two recombinant cell lines. We first tested rhFIX production in the human embryonic kidney 293 cells (293). Next, we tested a hepatic cell line (HepG2) because FIX is primarily expressed in the liver. Our results reveal that intracellular rhFIX expression was more efficient in HepG2/rhFIX (46%) than in 293/rhFIX (21%). The activated partial thromboplastin time test showed that HepG2/rhFIX expressed biologically active rhFIX 1.5 times higher than 293/rhFIX (P = 0.016). Recovery of rhFIX from the HepG2 by reversed-phase chromatography was straightforward. We found that rhFIX has a pharmacokinetic profile similar to that of FIX purified from human plasma when tested in hemophilic B model. HepG2/rhFIX cell line produced the highest levels of rhFIX, representing an efficient in vitro expression system. This work opens up the possibility of significantly reducing the costs of rhFIX production, with implications for expanding hemophilia B treatment in developing countries.