Expression of collagen, interstitial collagenase, and tissue inhibitor of metalloproteinases-1 in restenosis after carotid endarterectomy.

Extracellular matrix is the principal component of the fibrous caps of atherosclerotic plaques and intimal hyperplastic lesions of reconstructed arteries. Interstitial collagen form an important part of the matrix, and the balance between collagen synthesis and degradation by interstitial collagenase (matrix metalloproteinase-1, MMP-1) may determine whether plaques rupture or vessels develop stenosis. We examined type I procollagen gene expression in human atherosclerotic and restenotic carotid arteries using in situ messenger RNA (mRNA) hybridization and the expression of MMP-1 and its endogenous inhibitor (tissue inhibitor of metalloproteinases-1, TIMP-1) by immunohistochemistry. Compared with normal arteries, atherosclerotic plaques bed increased expression of immunoreactive MMP-1 and TIMP-1 with modest increase of type 1 procollagen mRNA. Early restenotic lesions (< 1.5 years) contained abundant type I procollagen mRNA but little immunoreactive MMP-1 and TIMP-1. Late restenotic lesions (> 4 years) resembled atheroma and exhibited increased immunoreactive MMP-1 and TIMP-1 as well as abundant type I procollagen mRNA. Compared with atherosclerotic plaques, type I procollagen is increased and MMP-1 is decreased in early restenotic lesions. MMP-1 and TIMP-1 expressions are upregulated in lesions with a clear atheroma. These findings suggest that the balance between proteolysis and matrix synthesis may influence both the stability of atheromatous plaques and the development of restenotic lesions.     

Contribution of Fc fragment of monoclonal antibodies to tetanus toxin neutralization

Neurotoxicity Research - Monoclonal antibodies (MAbs) against neurotoxin of Clostridium tetani are considered as a novel source of immunoglobulins for passive immunotherapy of tetanus. Toxin...     

High Infection Rate Outcomes in Long-bone Tumor Surgery with Endoprosthetic Reconstruction in Adults: A Systematic Review

Background

Limb salvage surgery (LSS) with endoprosthetic replacement is the most common method of reconstruction following bone tumor resection in the adult population. The risk of a postoperative infection developing is high when compared with conventional arthroplasty and there are no appropriate guidelines for antibiotic prophylaxis.

Questions/purposes

We sought to answer the following questions: (1) What is the overall risk of deep infection and the causative organism in lower-extremity long-bone tumor surgery with endoprosthetic reconstruction? (2) What antibiotic regimens are used with endoprosthetic reconstruction? (3) Is there a correlation between infection and either duration of postoperative antibiotics or sample size?

Methods

We conducted a systematic review of the literature for clinical studies that reported infection rates in adults with primary bony malignancies of the lower extremity treated with surgery and endoprosthetic reconstruction. The search included articles published in English between 1980 and July 2011.

Results

The systematic literature review yielded 48 studies reporting on a total of 4838 patients. The overall pooled weighted infection rate for lower-extremity LSS with endoprosthetic reconstruction was approximately 10% (95% CI, 8%–11%), with the most common causative organism reported to be Gram-positive bacteria in the majority of cases. The pooled weighted infection rate was 13% after short-term postoperative antibiotics and 8% after long-term postoperative antibiotics. There was no correlation between sample size and infection rate.

Conclusions

Infection rates of 10% are high when compared with rates for conventional arthroplasty. Our results suggest that long-term antibiotic prophylaxis decreases the risk of deep infection. However, the data should be interpreted with caution owing to the retrospective nature of the studies.     

Complications following hip arthroscopy: a retrospective review of the McMaster experience (2009–2012)

Background

The use of hip arthroscopy has been steadily rising as technology, experience and surgical education continue to advance. Previous reports of the complication rate associated with hip arthroscopy have varied. The purpose of this study was to report our experience with hip arthroscopy complications at a single Canadian institution (McMaster University).

Methods

We performed a retrospective chart review of 2 hip arthroscopists at the same institution to identify patients who had undergone the index surgery and had been followed for a minimum of 6 months postoperatively. We used a standard data entry form to collect information on patient demographic and clinical characteristics, including age, sex, surgical indication and type of complication if any.

Results

A total of 211 patients underwent 236 hip arthroscopies. The mean age at time of surgery was 37 ± 13 years and mean follow-up was 394 ± 216.5 days. The overall complication rate associated with hip arthroscopy was 4.2% (95% confidence interval 2.3%–7.6%). We identified 4 major and 6 minor complications.

Conclusion

Overall, hip arthroscopy appears to be safe, with minor complications occurring more frequently than major ones. However, surgeons should recognize the possibility of serious complications associated with this procedure. Future research should focus on prospective designs looking for potential prognostic factors associated with hip arthroscopy complications.     

The effect of jaw relaxation on pain anxiety during burn dressings: Randomised clinical trial

Aim

The purpose of this randomised clinical trial (RCT) was to determine the effect of jaw relaxation on pain anxiety related to dressing changes in burn injuries.

Introduction

Patients hospitalised with burns experience high levels of anticipatory anxiety during dressing changes, which cannot be completely managed by anxiolytic drugs. Nurses as members of the burn care team contribute to pain management by using relaxation techniques as one of the most frequently used approaches to pain anxiety management. However, there is not enough information about the effects of these techniques on pain anxiety of patients with burns. The aim of this study was to determine the effect of jaw relaxation on pain anxiety related to dressing changes in burn injuries.

Methods

It was a randomised clinical trial with a control group. A total of 100 patients hospitalised in Shahid Motahari Burn Centre affiliated with Tehran University of Medical Sciences were recruited by convenience sampling and were randomly assigned to either experimental or control groups using minimisation. With institutional approval and written consent, the experimental group practiced jaw relaxation for 20 min before entering the dressing room. Data were collected by the Burn Specific Pain Anxiety Scale (BSPAS) during July–December 2009 and analysed using Statistical Package for the Social Sciences (SPSS)-PC (17).

Results

An independent t-test showed no significant difference between mean pain anxiety scores in the experimental and control group before intervention (p = 0.787). A dependent t-test showed significantly less pain anxiety after intervention (before dressing) in the experimental group (p < 0.05). Moreover, the independent t-test showed that the post-dressing pain anxiety of the experimental group was less than the control group (p < 0.05). However, the dependent t-test showed no significant difference between before and after dressing pain anxiety (after intervention) in the experimental group (p = 0.303).

Conclusion

Nurses can independently decrease the pain anxiety of patients with burns and its subsequent physical and psychological burden by teaching the simple and inexpensive technique of jaw relaxation. Further research is needed to study the effect of this technique on pain anxiety of patients suffering from other painful procedures.     

Reduced phase switch capacity and functional adhesin expression of type 1-fimbriated Escherichia coli from immunoglobulin A-deficient individuals

The mannose-specific adhesin of type 1 fimbriae is the most common adhesin in Escherichia coli. One receptor for this adhesin is the carbohydrate chains of secretory immunoglobulin A (S-IgA), and intestinal E. coli from IgA-deficient individuals has a reduced capacity to adhere to mannose-containing receptors. Here, we investigated the expression of the mannose-specific adhesin and its capacity to switch to the fimbriated phenotype in colonic resident and transient E. coli strains isolated from control (n = 16) and IgA-deficient (n = 17) persons. Resident E. coli strains from IgA-deficient individuals displayed weaker mannose-specific adherence to colonic cells than resident strains from control individuals (21 versus 44 bacteria/cell, P = 0.0009) due to three mechanisms: a lower carriage rate of the fimH gene (90% versus 97%, not significant), more frequent failure to switch on the fim genes (30% versus 6%, P = 0.02), and the reduced adhesive potential of fimH(+) isolates capable of phase switch (26 versus 46 bacteria/cell, P = 0.02). On the other hand, resident strains from IgA-deficient individuals displayed stronger mannose-resistant adherence than resident strains from control individuals (P = 0.04) and transient strains from IgA-deficient individuals (P = 0.01). The presence of S-IgA appears to favor the establishment of E. coli clones which readily express mannose-specific adhesins in the bowel microbiota.     

Metformin protects PC12 cells against oxygen-glucose deprivation/reperfusion injury

Oxidative stress has a causative role in ischemic reperfusion-induced cell death. Evidence has shown that metformin is capable to reduce ischemic reperfusion injuries. The current study investigated the effect of metformin on ischemia/reperfusion-induced apoptosis in PC12 cells by evaluation of Bcl-2 family proteins expression. Cells were exposed to a time-dependent in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) injury and then treated with metformin. The intracellular reactive oxygen species (ROS) levels were measured. Western blotting was used to examine the expression of anti- and pro-apoptotic proteins. Moreover, the number of apoptotic cell death was evaluated by TUNEL assay. Our results showed that metformin attenuated ROS generation, downregulated pro-apoptotic BAX expression, and upregulated expression of the Bcl-2 protein in the PC12 cells. Moreover, metformin reduced cell death under OGD/R condition which was confirmed by lower apoptotic cell death in the TUNEL assay. These findings suggest that neuroprotective effect of metformin on OGD/R-induced cell death is possibly mediated by inhibition of ROS-induced apoptosis pathway.