Predictors of adverse neurological outcome following cardiac surgery

INTRODUCTION

Stroke is a debilitating complication of cardiac surgery. Many intraoperative and postoperative factors predict the likelihood of post-cardiac surgery stroke. We evaluated preoperative parameters, seeking correlations with adverse neurological outcome following cardiac surgery. We investigated the possibility of preoperative carotid ultrasonography to select patients for carotid endarterectomy pre- or intraoperatively.

METHODS

We conducted a retrospective analysis of 61 patients who suffered stroke post-cardiac surgery from 2003 to 2006. Data was collected for patient and disease characteristics, preoperative status, intraoperative events and postoperative course. Postoperative neurological complications were subdivided into three groups: mild/temporary events, moderate events such as seizures, and severe events such as stroke. A mild/temporary event was defined as a focal neurological deficit of less than 24 hours in duration.

RESULTS

A total of 2,226 cardiac cases were retrospectively evaluated. The frequency of stroke was 61 patients (2.7 percent). The mean age of these patients was 63.7 +/- 7.4 years, and 40 (65.6 percent) were males. Logistic EuroSCORE, left ventricular ejection fraction (as determined by two-dimensional echocardiogram) and aortic cross-clamp time were significantly correlated with postoperative neurological complications, with a p-value of less than 0.05 for all subgroups. There was a significant correlation between the presence of preoperative carotid disease (as proven by pre- and postoperative carotid ultrasonography) and postoperative neurological events (p-value equals 0.033). However, atrial fibrillation did not correlate with postoperative stroke.

CONCLUSION

The stage of cardiac disease (risk factor level, ejection fraction and presence of carotid stenosis) correlates with stroke and may predict an adverse neurological outcome.

Olympic fencers: adaptations in cortical and trabecular bone determined by quantitative computed tomography

We investigated how cortical bone, trabecular bone, and muscle adapt in US Olympic Fencing Team members. These athletes demonstrate femoral cortical bone expansion, greater distal femoral trabecular bone density, and greater muscle mass compared to controls. This is the first study to investigate musculoskeletal adaptations in Olympic fencers.

PURPOSE

Wolff's law states that bone remodels according to mechanical forces placed upon it. Our goal was to determine how cortical and trabecular bone adapt in Olympic athletes who perform intermittent high-impact activity.

MATERIALS AND METHODS

Nine males from the 2004 US Olympic Fencing Team and nine matched controls were evaluated by quantitative computed tomography. Femurs were scanned at 50% and 75% along the shaft. We evaluated cortical thickness (C.Th), cortical (C.Ar), trabecular (Tb.Ar), and total bone areas (Tot.Ar), proportions of C.Ar and Tb.Ar to Tot.Ar, cortical (C.BMD.), trabecular (Tb.MBD), and total bone densities (Tot.BMD), muscle (M.Ar), and thigh areas (Th.Ar).

RESULTS

Fencers had greater C.Th (+24.5 to 38.8%), C.Ar (+16.9 to 19.6%), C.Ar/Tot.Ar (+6.3 to 16.3%), and lower Tb.Ar/Tot.Ar (-23.5% to -23.8%; p<0.05). Fencers demonstrated a positive difference in C.Th in the dominant vs. nondominant thigh at 50% (+5.4%, p = 0.040) and at 75% (+13.8%, p = 0.048 by analysis of covariance). Fencers had 54% greater Tb.BMD at 75% (p = 0.025), but not at 50% (p = 0.63). There was no difference between groups for C.BMD (p = .66 at 50%, p = 0.88 at 75%). Fencers had greater M.Ar (+30%) and asymmetrically greater M.Ar (+12.2%) in the dominant thigh (p < 0.004).

CONCLUSION

In world-class athletes who perform intermittent, high-impact activity, cortical bone expands, trabecular bone density is greater, and muscle mass is greater. This is the first study to examine musculoskeletal adaptations in Olympic fencers.

Periostin facilitates eosinophil tissue infiltration in allergic lung and esophageal responses

Periostin is an extracellular matrix protein that has been primarily studied in the context of the heart, where it has been shown to promote cardiac repair and remodeling. In this study, we focused on the role of periostin in an allergic eosinophilic inflammatory disease (eosinophilic esophagitis (EE)) known to involve extensive tissue remodeling. Periostin was indeed markedly overexpressed (35-fold) in the esophagus of EE patients, particularly in the papillae, compared with control individuals. Periostin expression was downstream from transforming growth factor-beta and interleukin-13, as these cytokines were elevated in EE esophageal samples and markedly induced periostin production by primary esophageal fibroblasts (107- and 295-fold, respectively, at 10 ng ml(-1)). A functional role for periostin in eliciting esophageal eosinophilia was demonstrated, as periostin-null mice had a specific defect in allergen-induced eosinophil recruitment to the lungs and esophagus (66 and 72% decrease, respectively). Mechanistic analyses revealed that periostin increased (5.8-fold) eosinophil adhesion to fibronectin. As such, these findings extend the involvement of periostin to esophagitis and uncover a novel role for periostin in directly regulating leukocyte (eosinophil) accumulation in T helper type 2-associated mucosal inflammation in both mice and humans.

Efficacy of TNP on lower limb wounds: a meta-analysis

This meta-analysis of the three RCTs that have compared topical negative pressure with conventional treatment in patients with lower limb ulcers found that it significantly reduced healing times and increased the number of healed wounds.

Porous silk scaffolds can be used for tissue engineering annulus fibrosus

There is no optimal treatment for symptomatic degenerative disc disease which affects millions of people worldwide. One novel approach would be to form a patch or tissue replacement to repair the annulus fibrosus (AF) through which the NP herniates. As the optimal scaffold for this has not been defined the purpose of this study was to determine if porous silk scaffolds would support AF cell attachment and extracellular matrix accumulation and whether chemically decorating the scaffold with RGD peptide, which has been shown to enhance attachment for other cell types, would further improve AF cell attachment and tissue formation. Annulus fibrosus cells were isolated from bovine caudal discs and seeded into porous silk scaffolds. The percent cell attachment was quantified and the cell morphology and distribution within the scaffold was evaluated using scanning electron microscopy. The cell-seeded scaffolds were grown for up to 8 weeks and evaluated for gene expression, histological appearance and matrix accumulation. AF cells attach to porous silk scaffolds, proliferate and synthesize and accumulate extracellular matrix as demonstrated biochemically and histologically. Coupling the silk scaffold with RGD-peptides did not enhance cell attachment nor tissue formation but did affect cell morphology. As well, the cells had higher levels of type II collagen and aggrecan gene expression when compared to cells grown on the non-modified scaffold, a feature more in keeping with cells of the inner annulus. Porous silk is an appropriate scaffold on which to grow AF cells. Coupling RGD peptide to the scaffold appears to influence AF cell phenotype suggesting that it may be possible to select an appropriate scaffold that favours inner annulus versus outer annulus differentiation which will be important for tissue engineering an intervertebral disc.

Development of methods for coordinate measurement of total cell-associated and integrated human immunodeficiency virus type 1 (HIV-1) DNA forms in routine clinical samples: levels are not associated with clinical parameters, but low levels of integrated HIV-1 DNA may be prognostic for continued successful therapy

We have adapted our established Alu PCR assay for proviral DNA and PCR for total cellular DNA to a real-time PCR format and applied these to human immunodeficiency virus (HIV)-positive specimens collected for routine determination of the plasma viral load (pVL). In a cohort of five patients, measurements of integrated viral load (iVL) and cell-associated viral load (cVL) in CD4(+) cells isolated by a single positive selection step were not indicative of HIV DNA levels in the circulation, and further analysis was performed on peripheral blood mononuclear cells (PBMC). In a cohort of 46 samples total cVL was quantitated in most samples, but iVL could be quantitated in only 47.8%, since in 26% iVL was undetectable and in 21.7% the results were invalid due to high levels of unintegrated HIV DNA. There was no correlation of cVL or iVL with pVL, CD4 count, or duration of successful antiretroviral treatment. Out of 26 patients with undetectable pVL, 4 patients failed therapy within the subsequent 12 months and had higher than average iVL, but this was not the case for cVL. Among nine patients with long-term undetectable pVL, no consistent decline in cVL or iVL was seen with time, and changes in cVL and iVL within a patient could be concordant or discordant. These results show that cVL and iVL can be coordinately measured in PBMC from clinical samples but do not correlate with pVL, CD4 counts, or length of suppressive antiretroviral therapy. Interestingly, a high iVL (but not a high cVL) in patients with undetectable pVL was associated with subsequent treatment failure.

Diagnosis of Acute Q Fever by PCR on Sera during a Recent Outbreak in Rural South Australia

Diagnosis of Q fever has largely been dependent upon serology, which may lead to delayed diagnosis as seroconversion can take weeks to develop. During a recent Q fever outbreak (27 patients) in rural South Australia, we compared the diagnostic rate of serology with two separate real-time PCRs, the 27kDa outer membrane protein and the insertion sequence. PCR was positive (on either or both PCR assays) in sera of 67% of the patients. Median time required for making serological diagnosis was 17 days, compared with 4 days by PCR. Q fever PCR is an effective tool in the diagnosis of acute Q fever infection.