A comparative 18F-FDG and an anti-PD-L1 probe PET/CT imaging of implant-associated Staphylococcus aureus osteomyelitis.

Background: Early and accurate diagnosis of infection-induced osteomyelitis, which often involves increased PD-L1 expression, is crucial for better treatment outcomes. Radiolabeled anti-PD-L1 nuclear imaging allows for sensitive and non-invasive whole-body assessments of PD-L1 expression. This study aimed to compare the efficacy of 18F-FDG and an 18F-labeled PD-L1-binding peptide probe (18F-PD-L1P) in PET imaging of implant-associated Staphylococcus aureus osteomyelitis (IAOM). Methods: In this study, we synthesized an anti-PD-L1 probe and compared its efficacy with 18F-FDG and 18F-PD-L1P in PET imaging of implant-associated Staphylococcus aureus osteomyelitis (IAOM). The %ID/g ratios (i.e., radioactivity ratios between the infected and non-infected sides) of both probes were evaluated for sensitivity and accuracy in post-infected 7-day tibias and post-infected 21 days, and the intensity of 18F-PD-L1P uptake was compared with pathological changes measured by PD-L1 immunohistochemistry (IHC). Results: Compared with 18F-FDG, 18F-PDL1P demonstrated higher %ID/g ratios for both post-infected 7-day tibias (P=0.001) and post-infected 21 days (P=0.028). The intensity of 18F-PD-L1P uptake reflected the pathological changes of osteomyelitic bones. In comparison to 18F-FDG, 18F-PDL1P provides earlier and more sensitive detection of osteomyelitis caused by S. aureus. Conclusion: Our findings suggest that the 18F-PDL1P probe is a promising tool for the early and accurate detection of osteomyelitis caused by S. aureus.

Detection of ventilatory thresholds using near-infrared spectroscopy with a polynomial regression model.

Whether near-infrared spectroscopy (NIRS) is a convenient and accurate method of determining first and second ventilatory thresholds (VT1 and VT2) using raw data remains unknown. This study investigated the reliability and validity of VT1 and VT2 determined by NIRS skeletal muscle hemodynamic raw data via a polynomial regression model. A total of 100 male students were recruited and performed maximal cycling exercises while their cardiopulmonary and NIRS muscle hemodynamic data were measured. The criterion validity of VT1VET and VT2VET were determined using a traditional V-slope and ventilatory efficiency. Statistical significance was set at α = . 05. There was high reproducibility of VT1NIRS and VT2NIRS determined by a NIRS polynomial regression model during exercise (VT1NIRS, r = 0.94; VT2NIRS, r = 0.93). There were high correlations of VT1VET vs VT1NIRS (r = 0.93, p < .05) and VT2VET vs VT2NIRS (r = 0.94, p < .05). The oxygen consumption (VO2) between VT1VET and VT1NIRS or VT2VET and VT2NIRS was not significantly different. NIRS raw data are reliable and valid for determining VT1 and VT2 in healthy males using a polynomial regression model. Skeletal muscle raw oxygenation and deoxygenation status reflects more realistic causes and timing of VT1 and VT2.

Study on variation trend of repetitive nerve stimulation waveform in amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons with no effective cure. Electrophysiological studies have found decremental responses during low-frequency repetitive nerve stimulation (RNS) except for diffused neurogenic activities. However, the difference between ALS and generalized myasthenia gravis (GMG) in terms of waveform features is unclear. In the current study, we explored the variation trend of the amplitudes curve between ALS and GMG with low-frequency, positive RNS, and the possible mechanism is discussed preliminarily. METHODS: A total of 85 ALS patients and 41 GMG patients were recruited. All patients were from Peking Union Medical College Hospital (PUMCH) between July 1, 2012 and February 28, 2015. RNS study included ulnar nerve, accessory nerve and facial nerve at 3 Hz and 5 Hz stimulation. The percentage reduction in the amplitude of the fourth or fifth wave from the first wave was calculated and compared with the normal values of our hospital. A 15% decrease in amplitude is defined as a decrease in amplitude. RESULTS: The decremental response at low-frequency RNS showed the abnormal rate of RNS decline was 54.1% (46/85) in the ALS group, and the results of different nerves were 54.1% (46/85) of the accessory nerve, 8.2% (7/85) of the ulnar nerve and 0% (0/85) of the facial nerve stimulation, respectively. In the GMG group, the abnormal rate of RNS decline was 100% (41/41) at low-frequency RNS of accessory nerves. However, there was a significant difference between the 2 groups in the amplitude after the sixth wave. CONCLUSIONS: Both groups of patients are able to show a decreasing amplitude of low-frequency stimulation RNS, but the recovery trend after the sixth wave has significant variation. It implies the different pathogenesis of NMJ dysfunction of these 2 diseases.

Acute clenbuterol induces hypotension, atrioventricular block and cardiac asystole in the rabbit.

Clenbuterol is a long-lasting ß-adrenoceptor (ß-AR) agonist and was once medicated as a bronchial dilatator, and is also used by body-building enthusiasts and athletes and in livestock breeding because of its anabolic effect on skeletal muscles and ability to promote lipolysis. Though prohibited from pharmacological uses, clenbuterol intoxication cases are frequently reported, and most of the cardiac symptoms are tachyarrhythmia. Here, we reported a different cardiovascular toxic response to clenbuterol. Using a rabbit model, we tested the dose-response pattern of the cardiovascular system to intravenous administration of clenbuterol. Routine arterial blood pressure (BP) and surface electrocardiogram (ECG) were monitored. We observed that clenbuterol at a lower dose (0.4 mg/kg, n = 3) did not significantly affect the ECG, but decreased the mean BP roughly by 15-18 mmHg. At a medial dose (3.6 mg/kg, n = 3), clenbuterol induced significant hypotension (mean BP dropped by about 30 mmHg), first-degree atrioventricular (AV) block and intermittent ectopic activities with a relatively slow rate. The hypotension and arrhythmia recovered slowly, and animals did not die. Higher-dose clenbuterol (10 mg/kg, n = 6) induced severe hypotension, second-degree AV block (Mobitz type II), 2:1 ventricular capture and progressive prolongations of P-R intervals and QRS duration, and the animals soon died of cardiac asystole. Different from other reports, we had not observed lethal tachyarrhythmia in all experiments except for the slight heart rate acceleration during the recovery stage of medial clenbuterol dosage. These results indicate that acute intravenous administration of clenbuterol has serious, dose-dependent cardiovascular toxicities and is even life threatening.

Hypoxic exercise training causes erythrocyte senescence and rheological dysfunction by depressed Gardos channel activity.

Despite enhancing cardiopulmonary and muscular fitness, the effect of hypoxic exercise training (HE) on hemorheological regulation remains unclear. This study investigates how HE modulates erythrocyte rheological properties and further explores the underlying mechanisms in the hemorheological alterations. Twenty-four sedentary males were randomly divided into hypoxic (HE; n = 12) and normoxic (NE; n = 12) exercise training groups. The subjects were trained on 60% of maximum work rate under 15% (HE) or 21% (NE) O(2) condition for 30 min daily, 5 days weekly for 5 wk. The results demonstrated that HE 1) downregulated CD47 and CD147 expressions on erythrocytes, 2) decreased actin and spectrin contents in erythrocytes, 3) reduced erythrocyte deformability under shear flow, and 4) diminished erythrocyte volume changed by hypotonic stress. Treatment of erythrocytes with H(2)O(2) that mimicked in vivo prooxidative status resulted in the cell shrinkage, rigidity, and phosphatidylserine exposure, whereas HE enhanced the eryptotic responses to H(2)O(2). However, HE decreased the degrees of clotrimazole to blunt ionomycin-induced shrinkage, rigidity, and cytoskeleton breakdown of erythrocytes, referred to as Gardos effects. Reduced erythrocyte deformability by H(2)O(2) was inversely related to the erythrocyte Gardos effect on the rheological function. Conversely, NE intervention did not significantly change resting and exercise erythrocyte rheological properties. Therefore, we conclude that HE rather than NE reduces erythrocyte deformability and volume regulation, accompanied by an increase in the eryptotic response to oxidative stress. Simultaneously, this intervention depresses Gardos channel-modulated erythrocyte rheological functions. Results of this study provide further insight into erythrocyte senescence induced by HE.

Work-related musculoskeletal disorders in athletic trainer.

INTRODUCTION Athletic trainers often work for elongated and irregular hours or days, and need to react in emergency situations. These professionals are at risk for work-related musculoskeletal disorders (WMSDs). This study investigated the WMSDs experienced by athletic trainers (ATs), plus related personal and occupational factors. METHODS A customized questionnaire with subject's demographic and WMSDs information was constructed and administered in all accessible ATs in Taiwan. In addition to descriptive analysis of demographics and WMSDs, the relationship between personal/occupational-related factors and WMSD symptoms were also evaluated. Results A total of 146 effective questionnaires were returned. The results indicated that a 48.5% prevalence rate of athletic trainers in Taiwan, and these disorders are mainly located in low back (42%), finger (38%) and shoulder (26%) regions. Logistic regression revealed that average work hour (odds ratio (OR) = 1.834, 95% confidence interval (CI): 1.066-3.156) and continue education participation (OR = 0.346, 95% CI: 0.140-0.854) were the most significant predictors for WMSDs occurrence. Performing taping was the most significant predictor for the low back (OR = 28.274, 95% CI: 2.568-311.423) and finger (OR = 19.535, 95% CI:2.273-167.912) symptoms; while performing providing first aid (OR = 12.128, 95% CI:3.881-37.899) was the most significant predictor for the shoulder's. Conclusion This study revealed that athletic trainers in Taiwan area suffered from high rate of WMSDs, and the relationship between WMSDs and specific job features were reported. Preventive and therapeutic modifications of the work environment to decrease the occurrence of WMSDs are in need for athletic trainers and other similar professions. Further research examining safe patient handling ergonomics, proper equipment in the context of athletic training and professional development strategies must be pursued.

Effects of moderate and severe intermittent hypoxia on vascular endothelial function and haemodynamic control in sedentary men.

Acclimatization to intermittent hypoxia (IH) improves exercise performance by enhancing oxygen delivery and utilization, but the effect of IH on hemodynamic control remains unclear. This study investigates how two intensities of IH influence hemodynamic control to develop an IH regimen that improves aerobic fitness and minimizes risk of peripheral vascular disorder. Thirty healthy sedentary men were randomly divided into severe (SIH) and moderate (MIH) IH and control (C) groups. The subjects were exposed to 12% (SIH), 15% (MIH), or 21% (C) O2 for 1 h/day, 5 days/week for 4 weeks in a normobaric hypoxia chamber. The results demonstrate that (1) improved pulmonary ventilation and oxygen uptake by SIH and MIH; (2) SIH elevated blood pressure during exercise and increased plasma malondialdehyde and nitric oxide (NO) metabolite levels, accompanied by reduced hyperaemic arterial response, venous compliance, endothelium-dependent vasodilatation, and decreased plasma total antioxidant and vitamin E levels; (3) while such effects were not seen following MIH; and (4) there were no significant differences in endothelium-independent vasodilatation during all experimental periods among the three groups. We conclude that both SIH and MIH regimens improve pulmonary ventilation. However, SIH but not MIH decreases anti-oxidative capacity and increases lipid peroxidation in circulation, leading to suppression of vascular endothelial function, causing impairment of vascular haemodynamics.

Kinesiological and kinematical analysis for stroke subjects with asymmetrical cycling movement patterns.

This aim of this study is to provide quantitative analyses of asymmetrical movements between affected and unaffected limbs for hemiparetic subjects in a cycling ergometer. To acquire kinesiological and kinematical data, electromyography (EMG) of quadriceps muscles in the both legs as well as crank positions under three cycling workloads were recorded. The symmetry index (SI) was designed to measure the similarity between muscle activities recorded from affected and unaffected limbs. Using kinematical information of the crank position, the cycling unsmoothness (denoted as roughness index, RI) can be derived from the curvature of the instantaneous cycling speed. Thirteen hemiparetic subjects following a cerebrovascular accident (CVA) and eight able-bodied subjects participated in this study. With total symmetry at SI=1, the average SIs of hemiparetic subjects (0.66+/-0.18) were significantly lower (p<0.01) than those of normal subjects (0.91+/-0.08) but no significant difference found among three workloads. From the average RI, subjects with hemiparesis exhibited less smooth cycling movements compared to normal group (p<0.01). Non-parametric Friedman and Wilcoxon tests of RIs further indicated that the workload factors are significantly different only for hemiparetic group (p<0.01). No significant difference between lower workloads in RIs showed that the CVA subjects' sound side alone can execute most of the cycling load with minimal involvement of the affected side under lower workload condition. When cycling at a heavier load, however, it is essential to force the affected limb to assist in the pedaling, thus accomplishing an effective cycling exercise. By combining these two quantitative indices, we can observe the kinesiological measurement of the symmetry of EMG phasic activities from SI and the kinematical cycling smoothness in a coordinated movement from RI, which could provide a clinical guideline for cycling exercises for hemiparetic subjects.