Angiographic and intravascular ultrasound findings of the late catch-up phenomenon after intracoronary beta-radiation for the treatment of in-stent restenosis

We report one-year angiographic and intravascular ultrasound (IVUS) outcomes of in-stent restenosis (ISR) patients treated with intravascular brachytherapy (IVBT). The benefit of IVBT for treating ISR is well documented. However, few data exist on significant angiographic and intravascular ultrasonic in-stent lumen deterioration beyond the habitual 6-month analysis after the index radiation procedure or so-called late catch-up process in the treatment of ISR. Twenty-five consecutive patients with ISR were treated with IVBT using the Beta-Cath System (a 40 mm 90 Sr per 90 gamma source). Quantitative angiographic and IVUS analysis was performed in all of them at 6 and 12 months. IVBT was successful in all patients. Four patients (16%) developed recurrent angiographic binary restenosis at 6-month follow-up, all located within the adjacent reference segments, with 2 being associated with geographical miss. An additional 4 patients (16%) presented with recurrent ISR at 12-month follow-up, all within the stented segment. Significant in-stent lumen loss (0.16 +/- 0.42 mm to 0.34 +/- 0.46 mm; p = 0.008) and in-stent intimal hyperplasia growth (+11.2 +/- 0.48 mm3; p = 0.03) was observed between 6 and 12 months. Intracoronary beta-radiation for the treatment of ISR was associated with significant luminal deterioration (late catch-up) within the stents between 6 and 12 months due to an important late progression of in-stent intimal hyperplasia.     

Multidrug-resistant tuberculosis: case reports study in a central state of Brazil

Multidrug-resistant tuberculosis (MDR-TB) is an emerging and worrisome health problem that threatens tuberculosis (TB) control worldwide. The clinical management of MDR-TB is a complex issue associated with the use of multiple drugs for a long period, usually accompanied by side effects and high costs. The objective of this work was to relate cases of MDR-TB occurring in Goiás, a central state of Brazil. We related five cases of MDR-TB, three women and two men. All were pulmonary cases. Three were in their second treatment and two in their first treatment. Surgical pulmonary resection was performed in one case. One death occurred. Lack of adherence, gastric intolerance to anti-TB drugs and poor clinical management were the main aspects related to the emergent resistance. A revision of the main clinical aspects of this disease was performed.     

Humoral immune response to measles and varicella vaccination in former very low birth weight preterm infants

Introduction

Immune response to vaccination in infants born prematurely may be lower than in infants born at full-term. Some clinical factors might be associated with humoral immune response.

Does clinical outcome of birch pollen immunotherapy relate to induction of blocking antibodies preventing IgE from allergen binding? A pilot study monitoring responses during first year of AIT

Background

The clinical benefit of allergen-specific immunotherapy (AIT) involves induction of blocking antibodies. It is not clear if these antibodies function via steric hindrance alone or a combination of levels, avidities, and epitope specificities, and clinical outcome cannot be predicted. We aim to in-depth characterize serum antibody profiles during birch pollen AIT, investigate therapy-induced antibodies for their capacity to block IgE binding to Bet v 1 and correlate data with clinical outcomes.

Methods

Immune responses of five birch pollen allergic patients were monitored during the first year of AIT by nasal provocation tests (NPTs), ImmunoCAP, immunoblots, direct and avidity enzyme-linked immunosorbent assays, mediator release assays, facilitated antigen binding (FAB) assays, and inhibition mediator release assays.

Results

There was no correlation between NPT results and therapy-induced changes in levels (IgE, IgG, IgA, IgM), avidities, or mediator release potency of Bet v 1-specific antibodies. In FAB assays, blocking antibodies initiated upon AIT were shown to prevent formation of Bet v 1-IgE complexes of an indicator serum pool and significantly correlated with clinical readout. Inhibition mediator release assays using patient-specific IgE for passive sensitization revealed therapy-induced blocking capacities with very good correlation to NPT results. Notably, this assay was the only one to detect a non-responder during treatment in this pilot study.

Conclusions

Clinical outcome of AIT depends on induction of blocking antibodies able to prevent the patient’s own IgE from allergen binding. Monitoring of clinical efficacy seems to be best achieved using the inhibition mediator release assay, as development of relevant blocking antibodies can be verified in a patient-tailored manner.

     

Development of a vibration haptic simulator for shoulder arthroplasty

Purpose

Glenoid reaming is a technically challenging step during shoulder arthroplasty that could possibly be learned during simulation training. Creation of a realistic simulation using vibration feedback in this context is innovative. Our study focused on the development and internal validation of a novel glenoid reaming simulator for potential use as a training tool.

Methods

Vibration and force profiles associated with glenoid reaming were quantified during a cadaveric experiment. Subsequently, a simulator was fabricated utilizing a haptic vibration transducer with high- and low-fidelity amplifiers; system calibration was performed matching vibration peak–peak values for both amplifiers. Eight experts performed simulated reaming trials. The experts were asked to identify isolated layer profiles produced by the simulator. Additionally, experts’ efficiency to successfully perform a simulated glenoid ream based solely on vibration feedback was recorded.

Results

Cadaveric experimental cartilage reaming produced lower vibrations compared to subchondral and cancellous bones (\(p\le 0.03\)). Gain calibration of a lower-fidelity (3.5 \({g}_{\mathrm{pk-pk}}, 0.36\,{g}_{\mathrm{rms}})\) and higher-fidelity (3.4 \({g}_{\mathrm{pk-pk}}, 0.33\,{g}_{\mathrm{rms}})\) amplifier resulted in values similar to the cadaveric experimental benchmark (3.5 \({g}_{\mathrm{pk-pk}}, 0.30\,{g}_{\mathrm{rms}})\). When identifying random tissue layer samples, experts were correct \(52\pm 9\%\) of the time and success rate varied with tissue type (\(p=0.003\)). During simulated reaming, the experts stopped at the targeted subchondral bone with a success rate of \(78\pm 24\%\). The fidelity of the simulation did not have an effect on accuracy, applied force, or reaming time (\(p>0.05\)). However, the applied force tended to increase with trial number (\(p=0.047\)).

Conclusions

Development of the glenoid reaming simulator, coupled with expert evaluation furthered our understanding of the role of haptic vibration feedback during glenoid reaming. This study was the first to (1) propose, develop and examine simulated glenoid reaming, and (2) explore the use of haptic vibration feedback in the realm of shoulder arthroplasty.

     

Myocardial Salvage Imaging: Where Are We and Where Are We Heading? A Cardiac Magnetic Resonance Perspective

Purpose of Review

Cardiac magnetic resonance (CMR) has emerged in recent years as a reliable tool to assess, in a single examination after a reperfused myocardial infarction, the initially area at risk (AAR), the final infarct size (IS), and from their difference the salvaged myocardium (SM). The aim of the present review is to summarize recent advances in the CMR imaging of SM.

Recent Findings

While there is consensus on the use of late gadolinium enhancement (LGE) to calculate IS, how to assess the AAR is a debated topic. The use of T2-weighted short-TI inversion recovery (T2W-STIR) is to date supported by a large amount of data, but it is affected by several limitations. Newer techniques have been developed to overcome T2W-STIR limitations, some of them have been already used in randomized clinical trials (RCTs) while others are showing promising results. The use of CMR to generate surrogate endpoints in RCTs is gaining attention; in this context, analysis of data from recent RCTs suggests that the assessment of SM as outcome measure could be useful to reduce sample sizes and costs of trials.

Summary

CMR is a reliable technique for the assessment of SM. LGE is the gold standard for IS measurement, while which is the best technique for the evaluation of AAR is still debated. When using CMR-derived endpoints in RCTs, the assessment of SM is advisable.

     

Prevalence and reliability of treatment-based classification for subgrouping patients with low back pain

Objectives: To observe the distribution of patients who presented with low back pain (LBP) and to determine the between therapists’ interrater reliability of assessments in a private outpatient setting using treatment-based classification (TBC) subgroups.

Methods: An observational and methodological study was conducted. Four hundred and twenty-nine patients (231 male; 198 female) presenting LBP symptoms and referred to conservative treatment were assessed by 13 physical therapists who conducted a 60-min examination process utilizing TBC subgroups. Interrater reliability analyses from six raters were assessed using Fleiss’ kappa and previously recorded data (n = 30).

Results: In this study, 65.74% of patients were classified in only one subgroup, the most prevalent being stabilization (21.91%), followed by extension (15.38%), traction (11.89%), flexion (10.96%), manipulation (5.13%), and lateral shift (0.47%). Approximately 20.98% of patients were classified in two subgroups, where the most frequent overlaps were flexion + stabilization (7.46%), extension + stabilization (6.06%), flexion + traction (4.20%), extension + manipulation (1.86%), and 13.29% of patients were not classified in any TBC subgroup. Analysis of interrater reliability showed a kappa value of 0.62 and an overall agreement of 66% between raters.

Discussion: LBP is a heterogeneous clinical condition and several classification methods are proposed in the attempt to observe better outcomes for patients. Eighty-five percent of patients assessed were able to be classified when using the TBC assessment and reliability analysis showed a substantial agreement between raters.

Level of Evidence: 2c.     

The interplay between metabolic alterations,diastolic strain rate and exercise capacity in mild heart failure with preserved ejection fraction: a cardiovascular magnetic resonance study

Background

Heart failure (HF) is characterized by altered myocardial substrate metabolism which can lead to myocardial triglyceride accumulation (steatosis) and lipotoxicity. However its role in mild HF with preserved ejection fraction (HFpEF) is uncertain. We measured myocardial triglyceride content (MTG) in HFpEF and assessed its relationships with diastolic function and exercise capacity.

Methods

Twenty seven HFpEF (clinical features of HF, left ventricular EF >50%, evidence of mild diastolic dysfunction and evidence of exercise limitation as assessed by cardiopulmonary exercise test) and 14 controls underwent ¹H-cardiovascular magnetic resonance spectroscopy (¹H-CMRS) to measure MTG (lipid/water, %), ³¹P-CMRS to measure myocardial energetics (phosphocreatine-to-adenosine triphosphate - PCr/ATP) and feature-tracking cardiovascular magnetic resonance (CMR) imaging for diastolic strain rate.

Results

When compared to controls, HFpEF had 2.3 fold higher in MTG (1.45?±?0.25% vs. 0.64?±?0.16%, p?=?0.009) and reduced PCr/ATP (1.60?±?0.09 vs. 2.00?±?0.10, p?=?0.005). HFpEF had significantly reduced diastolic strain rate and maximal oxygen consumption (VO₂ max), which both correlated significantly with elevated MTG and reduced PCr/ATP. On multivariate analyses, MTG was independently associated with diastolic strain rate while diastolic strain rate was independently associated with VO₂ max.

Conclusions

Myocardial steatosis is pronounced in mild HFpEF, and is independently associated with impaired diastolic strain rate which is itself related to exercise capacity. Steatosis may adversely affect exercise capacity by indirect effect occurring via impairment in diastolic function. As such, myocardial triglyceride may become a potential therapeutic target to treat the increasing number of patients with HFpEF.

     

Reliability of two pragmatic tools for assessing text neck

Background

There is a hypothesis that the growing use of mobile phones in an inappropriate posture to text and read (text neck) could be a reason for the increasing prevalence of neck pain in the past decade. Before testing if there is an association between text neck and neck pain, it is necessary to develop reliable pragmatic tools appropriate to epidemiological studies.