Ultrasound-Guided Versus Landmark-Guided Local Corticosteroid Injection for Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To review the literature and assess the comparative effectiveness of ultrasound-guided versus landmark-guided local corticosteroid injections in patients with carpal tunnel syndrome (CTS).

Peptide tag forming a rapid covalent bond to a protein, through engineering a bacterial adhesin

Protein interactions with peptides generally have low thermodynamic and mechanical stability. Streptococcus pyogenes fibronectin-binding protein FbaB contains a domain with a spontaneous isopeptide bond between Lys and Asp. By splitting this domain and rational engineering of the fragments, we obtained a peptide (SpyTag) which formed an amide bond to its protein partner (SpyCatcher) in minutes. Reaction occurred in high yield simply upon mixing and amidst diverse conditions of pH, temperature, and buffer. SpyTag could be fused at either terminus or internally and reacted specifically at the mammalian cell surface. Peptide binding was not reversed by boiling or competing peptide. Single-molecule dynamic force spectroscopy showed that SpyTag did not separate from SpyCatcher until the force exceeded 1 nN, where covalent bonds snap. The robust reaction conditions and irreversible linkage of SpyTag shed light on spontaneous isopeptide bond formation and should provide a targetable lock in cells and a stable module for new protein architectures.     

Myocardial protection with mild hypothermia

Mild hypothermia, 32-35° C, is very potent at reducing myocardial infarct size in rabbits, dogs, sheep, pigs, and rats. The benefit is directly related to reduction in normothermic ischaemic time, supporting the relevance of early and rapid cooling. The cardioprotective effect of mild hypothermia is not limited to its recognized reduction of infarct size, but also results in conservation of post-ischaemic contractile function, prevention of no-reflow or microvascular obstruction, and ultimately attenuation of left ventricular remodelling. The mechanism of the anti-infarct effect does not appear to be related to diminished energy utilization and metabolic preservation, but rather to survival signalling that involves either the extracellular signal-regulated kinases and/or the Akt/phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Initial clinical trials of hypothermia in patients with ST-segment elevation myocardial infarction were disappointing, probably because cooling was too slow to shorten normothermic ischaemic time appreciably. New approaches to more rapid cooling have recently been described and may soon be available for clinical use. Alternatively, it may be possible to pharmacologically mimic the protection provided by cooling soon after the onset of ischaemia with an activator of mild hypothermia signalling, e.g. extracellular signal-regulated kinase activator, that could be given by emergency medical personnel. Finally, the protection afforded by cooling can be added to that of pre- and post-conditioning because their mechanisms differ. Thus, myocardial salvage might be greatly increased by rapidly cooling patients as soon as possible and then giving a pharmacological post-conditioning agent immediately prior to reperfusion.     

Vascular endothelial dysfunction in Duchenne muscular dystrophy is restored by bradykinin through upregulation of eNOS and nNOS

Little is known about the vascular function and expression of endothelial and neuronal nitric oxide synthases (eNOS and nNOS) in Duchenne muscular dystrophy (DMD). Bradykinin is involved in the regulation of eNOS expression induced by angiotensin-converting enzyme inhibitors. We characterized the vascular function and eNOS and nNOS expression in a canine model of DMD and evaluated the effects of chronic bradykinin treatment. Vascular function was examined in conscious golden retriever muscular dystrophy (GRMD) dogs with left ventricular dysfunction (measured by echocardiography) and in isolated coronary arteries. eNOS and nNOS proteins in carotid arteries were measured by western blot and cyclic guanosine monophosphate (cGMP) content was analyzed by radioimmunoassay. Compared with controls, GRMD dogs had an impaired vasodilator response to acetylcholine. In isolated coronary artery, acetylcholine-elicited relaxation was nearly absent in placebo-treated GRMD dogs. This was explained by reduced nNOS and eNOS proteins and cGMP content in arterial tissues. Chronic bradykinin infusion (1 μg/min, 4 weeks) restored in vivo and in vitro vascular response to acetylcholine to the level of control dogs. This effect was NO-mediated through upregulation of eNOS and nNOS expression. In conclusion, this study is the first to demonstrate that DMD is associated with NO-mediated vascular endothelial dysfunction linked to an altered expression of eNOS and nNOS, which can be overcome by bradykinin.     

Serum Isoform [−2]proPSA Derivatives Significantly Improve Prediction of Prostate Cancer at Initial Biopsy in a Total PSA Range of 2–10 ng/ml: A Multicentric European Study

Background

Strategies to reduce prostate-specific antigen (PSA)–driven prostate cancer (PCa) overdiagnosis and overtreatment seem to be necessary.

Objective

To test the accuracy of serum isoform [−2]proPSA (p2PSA) and its derivatives, percentage of p2PSA to free PSA (fPSA; %p2PSA) and the Prostate Health Index (PHI)—called index tests—in discriminating between patients with and without PCa.

Design, setting, and participants

This was an observational, prospective cohort study of patients from five European urologic centers with a total PSA (tPSA) range of 2–10 ng/ml who were subjected to initial prostate biopsy for suspected PCa.

Outcome measurements and statistical analysis

The primary end point was to evaluate the specificity, sensitivity, and diagnostic accuracy of index tests in determining the presence of PCa at prostate biopsy in comparison to tPSA, fPSA, and percentage of fPSA to tPSA (%fPSA) (standard tests) and the number of prostate biopsies that could be spared using these tests. Multivariable logistic regression models were complemented by predictive accuracy analysis and decision curve analysis.

Results and limitations

Of >646 patients, PCa was diagnosed in 264 (40.1%). Median tPSA (5.7 vs 5.8 ng/ml; p = 0.942) and p2PSA (15.0 vs 14.7 pg/ml) did not differ between groups; conversely, median fPSA (0.7 vs 1 ng/ml; p < 0.001), %fPSA (0.14 vs 0.17; p < 0.001), %p2PSA (2.1 vs 1.6; p < 0.001), and PHI (48.2 vs 38; p < 0.001) did differ significantly between men with and without PCa. In multivariable logistic regression models, p2PSA, %p2PSA, and PHI significantly increased the accuracy of the base multivariable model by 6.4%, 5.6%, and 6.4%, respectively (all p < 0.001). At a PHI cut-off of 27.6, a total of 100 (15.5%) biopsies could have been avoided. The main limitation is that cases were selected on the basis of their initial tPSA values.

Conclusions

In patients with a tPSA range of 2–10 ng/ml, %p2PSA and PHI are the strongest predictors of PCa at initial biopsy and are significantly more accurate than tPSA and %fPSA.

Trial registration

The study is registered at http://www.controlled-trials.com, ref. ISRCTN04707454.     

Assessment of the Thrombogenic Effect of Fibrin Sealant Dressing in a Vascular Surgery Model in Rabbits

This study's objective was to investigate the potential thrombogenic effects of thrombin-containing fibrin sealant dressings (FSD) in a vascular repair model. Oval-shaped pieces of the rabbit abdominal aorta and vena cava were excised, the injuries were repaired with FSD, and animals were allowed to recover. Thrombus formation was examined by (1) an infusion of indium-labeled platelets into the rabbits following FSD application and estimation of total number of platelets attached to the wounds at 2, 4, and 6 h later (short-term effect, n = 12); and by (2) morphological and histological examinations of the vessels and dressings on days 1, 3, and 7 after repair operation in another group of rabbits (long-term effect, n = 12). Application of FSD sealed the vascular injures and produced immediate hemostasis that was stable up to 1 week. The highest numbers of platelets (both native and labeled) adhered to the arterial and venous repair sites were 6.5 × 10⁶ and 4.4 × 10⁷, respectively, 6 h after operation. The adhered platelets, however, did not form a visible and clinically significant thrombus. In long-term experiments, no evidence of thrombus was found in the lumens of the repaired vessels or on the dressings, and no microthrombi were detected histologically in other tissues at any time point. Although vena caval injuries showed signs of healing at day 7 postoperatively, the aortic wounds expanded progressively (pseudoaneurysm) and were prone to rupture at later times. Thus, direct exposure of FSD does not cause intravascular thrombosis or thrombotic events in rabbits. The dressing appears to be safe and effective for short-term repair of vascular injuries. It may also allow healing of minor venous defects, but cannot replace conventional surgical techniques (suturing) for permanent repair of arterial damages.