The Impact of MRSA Colonization on Surgical Site Infection Following Major Gastrointestinal Surgery

Purpose

The purpose of this study is to determine whether methicillin-resistant Staphylococcus aureus (MRSA) colonization affects surgical site infections (SSI) after major gastrointestinal (GI) operations.

Methods

We retrospectively reviewed the charts of all patients undergoing major GI surgery from December 2007 to August 2009. All patients were tested for MRSA colonization and grouped according to results (MRSA+, methicillin-sensitive S. aureus [MSSA]+, and negative). Data analyzed included demographics, incidence of SSI, and wound culture results.

Results

A total of 1,137 patients were identified; 78.9 % negative, 14.7 % MSSA+, and 6.4 % MRSA+. The mean age was 59.5 years, 44.5 % of the patients were men, and 47.9 % of the patients underwent colorectal operation. SSI was identified in 101 (8.9 %) patients and was higher in the MRSA+ group than the negative and MSSA+ groups (13.7 vs. 9.4 vs. 4.2 %; p?<?0.05). Although MRSA colonization had an odds ratio of 1.43 for developing an SSI, it was not a significant independent risk factor. However, the MRSA+ group was strongly associated with MRSA cultured from the wound when SSI was present (70 vs. 8.5 %; p?<?0.0001).

Conclusions

MRSA colonization is not an independent risk factor for SSI following major GI operations; however, it is strongly predictive of MRSA-associated SSI in these patients. Preoperative MRSA nasal swab test with decolonization may reduce the incidence of MRSA-associated SSI after major GI surgery.     

Loss of p53 cooperates with K‐ras activation to induce glioma formation in a region‐independent manner

Gliomas are recognized as a heterogeneous group of neoplasms differing in their location and morphological features. These differences, between and within varying grades of gliomas, have not been explained solely on the grounds of an oncogenic stimulus. Interactions with the tumor microenvironment as well as inherent characteristics of the cell of origin are likely a source of this heterogeneity. There is an ongoing debate over the cell of origin of gliomas, where some suggest a progenitor, while others argue for a stem cell origin. Thus, it is presumed that neurogenic regions of the brain such as the subventricular zone (SVZ) containing large numbers of neural stem and progenitor populations are more susceptible to transformation. Our studies demonstrate that K‐ras^G12D cooperates with the loss of p53 to induce gliomas from both the SVZ and cortical region, suggesting that cells in the SVZ are not uniquely gliomagenic. Using combinations of doxycycline‐inducible K‐ras^G12D and p53 loss, we show that tumors induced by the cooperative actions of these genes remain dependent on active K‐ras expression, as deinduction of K‐ras^G12D leads to complete tumor regression despite absence of p53. These results suggest that the interplay between specific combinations of genetic alterations and susceptible cell types, rather than the site of origin, are important determinates of gliomagenesis. Additionally, this model supports the view that, although several genetic events may be necessary to confer traits associated with oncogenic transformation, inactivation of a single oncogenic partner can undermine tumor maintenance, leading to regression and disease remission. GLIA 2013;61:1862–1872     

Fluorescence, birefringence and confocal microscopy of the abdominal aorta from nonobese diabetic (NOD) mice

In this study, nonenzymatic glycosylation was assessed in aorta extracellular matrix (ECM) from nonobese diabetic (NOD) mice, using nitroblue tetrazolium (NBT). Molecular and structural changes were investigated in elastic lamellae and collagen fibers of diabetic mice aortas after staining with dansyl chloride and anilinonaphthalene sulfonate (ANS). Alterations in arterial autofluorescence and birefringence of collagen fibers were investigated in unstained aortas. Proliferation of smooth muscle cells (SMC) was also investigated by Feulgen reaction staining assessed by confocal microscopy and image analysis. Assessment of nonenzymatic glycosylation demonstrated glycosylation products in the aorta ECM of NOD mice. Elastic lamellae and collagen fibers from NOD mouse aortas presented less intense fluorescence after staining with dansyl chloride and ANS when compared to aortas of control nondiabetic mice. However, unstained NOD aortas showed more intense autofluorescence when compared to controls. Birefringence analysis suggests alterations in the higher molecular packing of the arterial collagen fibers in NOD aortas. In aortas stained by Feulgen reaction, no evidence of SMC proliferation was observed in diabetic aortas.     

The effects of photobiomodulation using LED on the repair process of skin graft donor sites

Lasers in Medical Science - The benefits of photobiomodulation (PBM) applied to wounds are well-described in the literature; however, its effects in skin graft donor sites have been poorly studied....     

Photobiomodulation via a cluster device associated with a physical exercise program in the level of pain and muscle strength in middle-aged and older women with knee osteoarthritis: a randomized placebo-controlled trial

Osteoarthritis (OA) is a chronic joint disease that leads to pain and functional incapacity. The aim of the study is to investigate the effects of the incorporation of photobiomodulation (PBM) (via cluster) into a physical exercise program on the level of pain, lower limb muscle strength, and physical capacity, in patients with knee OA. Sixty-two female volunteers with a diagnosis of knee OA were distributed in 4 groups: exercise associated with placebo PBM group, exercise associated with active PBM group, active PBM group, and placebo PBM group. Sixteen sessions of lower limb strength exercises and PBM via cluster (808 nm, 100 mW, 7 points each side, 56 J total) were performed. The level of pain, physical capacity, and lower limb muscle strength were evaluated with the use of the numeric pain rating scale (NPRS), 6-min walking test (6-MWT) and timed up and go (TUG), and maximal voluntary isometric torque (MVIT) before and after the interventions. Both groups presented a significant decrease in the level of pain when compared with the placebo-treated women. Furthermore, the 6-MWT showed that the trained groups (with or without PBM) demonstrated higher values in the distance walked comparing pre and post-treatment values. The same behavior was found for the MVIT load before and after intervention. TUG was higher for all the treated with exercise groups comparing the pre and post-treatment values. Physical exercise and PBM showed analgesic effects. However, PBM did not have any extra effect along with the effects of exercise in improving the distance walked, the TUG, and the muscle strength.

Trial registration: RBR-7t6nzr