Pulmonary morphofunctional effects of mechanical ventilation with high inspiratory air flow

Objective: Uncertainties about the numerous degrees of freedom in ventilator settings leave many unanswered questions about the biophysical determinants of lung injury. We investigated whether mechanical ventilation with high air flow could yield lung mechanical stress even in normal animals. Design. Prospective, randomized, controlled experimental study. Setting: University research laboratory. Subjects. Thirty normal male Wistar rats (180-230 g). Interventions: Rats were ventilated for 2 hrs with tidal volume of 10 mL/kg and either with normal inspiratory air flow (V`) of 10 mL/s (F10) or high V` of 30 mL/s (F30). In the control group, animals did not undergo mechanical ventilation. Because high flow led to elevated respiratory rate (200 breaths/min) and airway peak inspiratory pressure (PIP,aw = 17 cm H2O), two additional groups were established to rule out the potential contribution of these variables: a) normal respiratory rate = 100 breaths/min and V` = 30 mL/sec; and b) PIP,aw = 17 cm H2O and V` 10 mL/sec. Measurements and Main Results: Lung mechanics and histology (light and electron microscopy), arterial blood gas analysis, and type III procollagen messenger RNA expression in lung tissue were analyzed. Ultrastructural microscopy was similar in control and F10 groups. High air flow led to increased lung plateau and peak pressures, hypoxemia, alveolar hyperinflation and collapse, pulmonary neutrophilic infiltration, and augmented type III procollagen messenger RNA expression compared with control rats. The reduction of respiratory rate did not modify the morphofunctional behavior observed in the presence of increased air flow. Even though the increase in peak pressure yielded mechanical and histologic changes, type III procollagen messenger RNA expression remained unaltered. Conclusions: Ventilation with high inspiratory air flow may lead to high tensile and shear stresses resulting in lung functional and morphologic compromise and elevation of type III procollagen messenger RNA expression.

High Prevalence of Clarithromycin Resistance and cagA, vacA, iceA2, and babA2 Genotypes of Helicobacter pylori in Brazilian Children

We isolated 45 Helicobacter pylori strains from 217 child patients. Resistance to clarithromycin, metronidazole, amoxicillin, and tetracycline was detected in 27%, 13%, 4%, and 0% of strains, respectively. The A2143G mutation was the most prevalent (67%) among clarithromycin-resistant strains. In addition, strain genotyping revealed a significant association between gastritis severity and the simultaneous presence of cagA, vacA s1m1, iceA2, and babA2 genes.

Effect of Exercise Training on Plasma Levels and Functional Properties of High-Density Lipoprotein Cholesterol in the Metabolic Syndrome

Intense lifestyle modifications can change the high-density lipoprotein (HDL) cholesterol concentration. The aim of the present study was to analyze the early effects of short-term exercise training, without any specific diet, on the HDL cholesterol plasma levels and HDL functional characteristics in patients with the metabolic syndrome (MS). We studied 30 sedentary subjects, 20 with and 10 without the MS. The patients with the MS underwent moderate intensity exercise training for 3 months on bicycle ergometers. Blood was sampled before and after training for biochemical analysis, paraoxonase-1 activity, and HDL subfraction composition and antioxidative capacity. Lipid transfer to HDL was assayed in vitro using a labeled nanoemulsion as the lipid donor. At baseline, the MS group had greater triglyceride levels and a lower HDL cholesterol concentration and lower paraoxonase-1 activity than did the controls. Training decreased the plasma triglycerides but did not change the low-density lipoprotein or HDL cholesterol levels. Nonetheless, exercise training increased the HDL subfractions` antioxidative capacity and paraoxonase-1 activity. After training, the MS group had compositional changes in the smallest HDL subfractions associated with increased free cholesterol and cholesterol ester transfers to HDL, reaching normal values. In conclusion, the present investigation has added relevant information about the dissociation between the quantitative and qualitative aspects of HDL after short-term exercise training without any specific diet in those with the MS, highlighting the importance of evaluating the functional aspects of the lipoproteins, in addition to their plasma levels. (C) 2011 Elsevier Inc. All rights reserved. (Am J Cardiol 2011;107:1168-1172)

ARTHROSCOPIC TREATMENT OF ACUTE ACROMIOCLAVICULAR JOINT DISLOCATION USING SUTURE ANCHORS

Objective: To present the clinical and radiographic results of a case series of patients with acute acromioclavicular dislocation (MD) treated by arthroscopic coracoclavicular fixation with suture anchors. Method: Twenty patients with AAD with less than 30 days since the injury were submitted to a coracoclavicular stabilization procedure using 2 suture anchors placed at the base of the coracoid process. Each suture anchor was connected to 2 strands of No.2 nonabsorbable-braided sutures, which were passed through the holes drilled in the clavicle and tied to the upper surface of the clavicle. The coracoclavicular distance was measured and compared to the opposite side using radiographic evaluation. Constant and UCLA scores were used to determine clinical and functional evaluation after 6 months. Results: Of the initial twenty cases, six were submitted to a new surgical procedure and were excluded from the study. Of the fourteen patients remaining, only two maintained the initial reduction, while the remainder presented some degree of reduction loss. The Constant and UCLA score averages were 94.79 (82-100) and 32.64 (26-35) respectively. Conclusion: The technique had a high incidence of reduction loss after 6 months of follow up. The clinical and functional evaluation was satisfactory, with a high average score. Level of Evidence: Level III, retrospective study.