Enhanced Pseudomonas aeruginosa biofilm development mediated by human neutrophils

Cystic fibrosis (CF) lung disease features persistent neutrophil accumulation to the airways from the time of infancy. CF children are frequently exposed to Pseudomonas aeruginosa, and by adulthood, 80% of CF patients are chronically infected. The formation of biofilms is a particularly important phenotypic characteristic of P. aeruginosa that allows for bacterial survival despite aggressive antibiotic therapy and an exuberant immune response. Here, we show that the presence of neutrophils enhances initial P. aeruginosa biofilm development over a period of 72 h through the formation of polymers comprised of actin and DNA. F-actin was found to be a site of attachment for P. aeruginosa. These actin and DNA polymers are present in CF sputum, and disruption of the polymers dispersed the associated P. aeruginosa cells and reduced biofilm development. These findings demonstrate a potential maladaptation of the primary innate response. When the host fails to eradicate the infection, cellular components from necrotic neutrophils can serve as a biological matrix to facilitate P. aeruginosa biofilm formation.     

Web Data Mining: Validity of Data from Google Earth for Food Retail Evaluation

To overcome the challenge of obtaining accurate data on community food retail, we developed an innovative tool to automatically capture food retail data from Google Earth (GE). The proposed method is relevant to non-commercial use or scholarly purposes. We aimed to test the validity of web sources data for the assessment of community food retail environment by comparison to ground-truth observations (gold standard). A secondary aim was to test whether validity differs by type of food outlet and socioeconomic status (SES). The study area included a sample of 300 census tracts stratified by SES in two of the largest cities in Brazil, Rio de Janeiro and Belo Horizonte. The GE web service was used to develop a tool for automatic acquisition of food retail data through the generation of a regular grid of points. To test its validity, this data was compared with the ground-truth data. Compared to the 856 outlets identified in 285 census tracts by the ground-truth method, the GE interface identified 731 outlets. In both cities, the GE interface scored moderate to excellent compared to the ground-truth data across all of the validity measures: sensitivity, specificity, positive predictive value, negative predictive value and accuracy (ranging from 66.3 to 100%). The validity did not differ by SES strata. Supermarkets, convenience stores and restaurants yielded better results than other store types. To our knowledge, this research is the first to investigate using GE as a tool to capture community food retail data. Our results suggest that the GE interface could be used to measure the community food environment. Validity was satisfactory for different SES areas and types of outlets.     

Surgical-site infection risk in oncologic digestive surgery

Surgical-site infection (SSI) is the most prevalent type of hospital infection in surgical patients and is associated with an increase in hospital stay, costs and morbidity/lethality. The knowledge of the main risk factors for this type of infection is important for the establishment of prevention measures regarding modifiable risks factors. The objective of the preset study was to assess the occurrence of SSI and study the risk factors in oncologic surgeries of the digestive system at Hospital de Câncer in Barretos, São Paulo, Brazil. Individuals undergoing oncologic surgeries of the digestive system in the period of 08/01/2007 to 08/10/2008 were prospectively followed for 30 days after surgery. Possible risk factors related to the patient and to the surgical procedure were also studied. A total of 210 surgeries were analyzed, with a global SSI incidence of 23.8%. The following variables were independently associated with SSI: time and type of surgery, radiotherapy before surgery and surgeon's years of experience. The risk factors found in this study have been described by other authors and are not amenable to intervention for SSI prevention. Further studies are recommended with the objective of investigating interventions that could reduce the risk for SSI in this type of surgery.     

Tailoring antimicrobials in febrile neutropenia: using faster diagnostic and communication tools to improve treatment in the era of extensively resistant pathogens

Febrile Neutropenia represents a medical emergency and the use of appropriate antimicrobial therapy is essential for a better outcome. Although being time-consuming, conventional cultures and antimicrobial susceptibility tests remain the golden standard practices for microbiology identification. Final reports are typically available within several days. Faster diagnostic tools, such as species identification trough Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) and molecular techniques might help to shorten time to diagnostic and also guide definitive therapy in this scenario. Here we present a case in which the use of a diagnostic molecular workflow combining MALDI-TOF and real-time PCR for relevant genes codifying antibiotic resistant integrated with instant communication report, led to a tailored and more appropriate treatment in a patient presenting with febrile neutropenia.     

Resistance Exercise Restores Endothelial Function and Reduces Blood Pressure in Type 1 Diabetic Rats

Background

Resistance exercise effects on cardiovascular parameters are not consistent.

Objectives

The effects of resistance exercise on changes in blood glucose, blood pressure and vascular reactivity were evaluated in diabetic rats.

Methods

Wistar rats were divided into three groups: control group (n = 8); sedentary diabetic (n = 8); and trained diabetic (n = 8). Resistance exercise was carried out in a squat device for rats and consisted of three sets of ten repetitions with an intensity of 50%, three times per week, for eight weeks. Changes in vascular reactivity were evaluated in superior mesenteric artery rings.

Results

A significant reduction in the maximum response of acetylcholine-induced relaxation was observed in the sedentary diabetic group (78.1 ± 2%) and an increase in the trained diabetic group (95 ± 3%) without changing potency. In the presence of NG-nitro-L-arginine methyl ester, the acetylcholine-induced relaxation was significantly reduced in the control and trained diabetic groups, but not in the sedentary diabetic group. Furthermore, a significant increase (p < 0.05) in mean arterial blood pressure was observed in the sedentary diabetic group (104.9 ± 5 to 126.7 ± 5 mmHg) as compared to that in the control group. However, the trained diabetic group showed a significant decrease (p < 0.05) in the mean arterial blood pressure levels (126.7 ± 5 to 105.1 ± 4 mmHg) as compared to the sedentary diabetic group.

Conclusions

Resistance exercise could restore endothelial function and prevent an increase in arterial blood pressure in type 1 diabetic rats.     

Blockade of CXCR1/2 chemokine receptors protects against brain damage in ischemic stroke in mice: Ischemia and Reparixin

OBJECTIVE:

Ischemic stroke may result from transient or permanent reductions of regional cerebral blood flow. Polymorphonuclear neutrophils have been described as the earliest inflammatory cells to arrive in ischemic tissue. CXCR1/2 receptors are involved in the recruitment of these cells. However, the contribution of these chemokine receptors during transient brain ischemia in mice remains poorly understood. In this work, we investigated the effects of reparixin, an allosteric antagonist of CXCR1/2 receptors, in a model of middle cerebral artery occlusion and reperfusion in mice.

METHODS:

C57BL/6J male mice treated with reparixin or vehicle were subjected to a middle cerebral artery occlusion procedure 1 h after the treatment. Ninety minutes after ischemia induction, the monofilament that prevented blood flow was removed. Twenty-four hours after the reperfusion procedure, behavioral changes, including motor signs, were analyzed with the SmithKline/Harwell/Imperial College/Royal Hospital/Phenotype Assessment (SHIRPA) battery. The animals were sacrificed, and brain tissue was removed for histological and biochemical analyses. Histological sections were stained with hematoxylin and eosin, neutrophil infiltration was estimated by myeloperoxidase activity and the inflammatory cytokine IL-1β was measured by ELISA.

RESULTS:

Pre-treatment with reparixin reduced the motor deficits observed in this model of ischemia and reperfusion. Myeloperoxidase activity and IL-1β were reduced in the reparixin-treated group. Histological analysis revealed that ischemic injury was also attenuated by reparixin pre-treatment.

CONCLUSIONS:

Our results suggest that the blockade of the CXCR1/2 receptors by reparixin promotes neuroprotective effects by reducing the levels of polymorphonuclear infiltration in the brain and the tissue damage associated with middle cerebral artery occlusion and reperfusion.     

Predictors of Excess Weight Loss in Obese Patients After Gastric Bypass: a 60-Month Follow-up

Background

The objective of this study was to analyze the factors associated with change in body mass index (BMI) and with percentage of excess weight loss (%EWL) in patients undergoing Roux-en-Y gastric bypass (RYGB). The following factors were analyzed: sex, age, surgical access (laparotomy vs. laparoscopy), preoperative BMI, waist circumference (WC), type 2 diabetes mellitus (T2DM), high blood pressure, and dyslipidemia.

Methods

Retrospective cohort study using a convenience sample of 2070 patients of both sexes, aged 18 to 65 years, undergoing RYGB between 2000 and 2013. The outcomes of interest were BMI and %EWL at 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months after RYGB.

Results

After 36, 48, and 60 months, approximately 50 % of patients had BMI >30 kg/m². As for %EWL, 60-month results were poor for 17 % of patients (%EWL <50 %), good for 40 % of patients (%EWL 50–75 %), very good for 24 % of patients (%EWL from >75–90 %), and excellent for 19 % of patients (%EWL >90 %). The four most significant predictors of BMI change 60 months after RYGB (in descending order of magnitude) were preoperative BMI, preoperative WC, surgical access, and age; and of %EWL, surgical access, preoperative BMI, preoperative WC, and age.

Conclusions

After 60 months of follow-up, the most relevant predictors of weight loss after RYGB were lower preoperative BMI and WC, videolaparoscopy as surgical access, and younger age. Further studies must be carried out to elucidate the impact of these factors on RYGB outcomes.