髁突-翼外肌解剖复位与游离复位治疗髁状突骨折的疗效比较

目的:比较髁突-翼外肌解剖复位与游离复位治疗髁状突骨折的疗效,促进髁突形态恢复。方法:收治的80例单侧髁状突骨折患者随机分为两组,每组40例,A组行髁突-翼外肌解剖复位术,B组行髁状突游离复位术,术后3个月、6个月观察髁突形态及下颌骨运动功能变化。结果:A组治愈率为90%,高于B组的70.00%(P0.05);术后3个月A组髁状突吸收、张口受限、开口偏斜、咬合关系紊乱、关节弹响发生率分别为12.50%、15.00%、15.00%、7.50%、12.50%,均低于B组的32.50%、35.00%、37.50%、25.00%、35.00%(P0.05);术后6个月A组张口受限、关节弹响发生率为5.00%、2.50%,均低于B组的20.00%、20.00%(P0.05);两组术后并发症发生率比较差异无统计学意义(P0.05)。结论:髁突-翼外肌解剖复位术保留髁状突骨折患者骨折断端血运,髁突形态及下颌骨运动能力恢复良好,疗效优于髁状突游离复位术。     

Simultaneous bilateral posteromedial tibial epiphysis stress fractures in a healthy young man: A case report

We present a compelling case of simultaneous, bilateral tibial stress fractures occurring in a unique epiphyseal and posterior location, with unclear aetiology. An overweight, Caucasian male in his late 20s developed synchronous bilateral medial knee pain following an intense 10-day training regimen. His radiographies were normal, but MRI revealed almost identical bilateral stress fracture lines in the posteromedial tibial epiphyses. Bone mineral densitometry and a full metabolic and hormonal panel were performed to further investigate potential underlying metabolic bone disease. He was found to have normal bone mineral densitometry and low Vitamin D serum values. Symptomatology greatly improved with activity modification. There were no further complaints and complications at 12 months’ follow-up. Diagnosis can be challenging and the treating physician should be acquainted with the basic science of stress fractures and main discriminating clinical, biochemical and radiological characteristics from insufficiency fractures, to avoid pitfalls in treatment decision.     

Application of positron emission tomography to neuroimaging in sports sciences

To investigate exercise-induced regional metabolic and perfusion changes in the human brain, various methods are available, such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), near-infrared spectroscopy (NIRS) and electroencephalography (EEG). In this paper, details of methods of metabolic measurement using PET, [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and [¹⁵O]radio-labelled water ([¹⁵O]H₂O) will be explained.Functional neuroimaging in the field of neuroscience was started in the 1970s using an autoradiography technique on experimental animals. The first human functional neuroimaging exercise study was conducted in 1987 using a rough measurement system known as ¹³³Xe inhalation. Although the data was useful, more detailed and exact functional neuroimaging, especially with respect to spatial resolution, was achieved by positron emission tomography. Early studies measured the cerebral blood flow changes during exercise. Recently, PET was made more applicable to exercise physiology and psychology by the use of the tracer [¹⁸F]FDG. This technique allowed subjects to be scanned after an exercise task is completed but still obtain data from the exercise itself, which is similar to autoradiography studies.In this report, methodological information is provided with respect to the recommended protocol design, the selection of the scanning mode, how to evaluate the cerebral glucose metabolism and how to interpret the regional brain activity using voxel-by-voxel analysis and regions of interest techniques (ROI).Considering the important role of exercise in health promotion, further efforts in this line of research should be encouraged in order to better understand health behavior. Although the number of research papers is still limited, recent work has indicated that the [¹⁸F]FDG-PET technique is a useful tool to understand brain activity during exercise.     

Cortisol and behavioral responses to enrichment in military working dogs

Our objective was to compare the effects of two schedules of enrichment exposure, a distributed (high frequency) and regular regime versus a mass (low frequency) and irregular regime, on the cortisol and behavioral responses of 14 kennelled military working dogs. The enrichment experiences were exercise coupled with human contact. Both groups of dogs were exposed to approximately the same total amount of enrichment per week for a total of 7 weeks. The distributed and regular regime (DRR) furnished enrichment for 20-min intervals three to four times a day every weekday; the mass and irregular regime (MIR) randomly furnished enrichment for 16 or 24 continuous hours 1 day out of 5. Our data show that: (1) cortisol concentrations of DRR dogs significantly decreased between the first and the last week of observations; this was not the case in MIR dogs; (2) at the 7th week DRR dogs had lower cortisol concentrations than did MIR dogs; (3) all dogs in each group exhibited stereotypies. Our results suggest that MIR dogs underwent a decline in welfare throughout the experiment, whereas DRR dogs appeared to undergo a period of acute stress at the beginning of their training that resolved over 7 weeks. This study suggests that the welfare of kennelled dogs, particularly military working dogs, is affected among other factors by schedules of exercise and contact with people.     

Effects of Treadmill Exercise on Cell Proliferation and Differentiation in the Subgranular Zone of the Dentate Gyrus in a Rat Model of Type II Diabetes

In the present study, we investigated the effects of a treadmill exercise on serum glucose levels and Ki67 and doublecortin (DCX) immunoreactivity, which is a marker of cell proliferation expressed during cell cycles except G0 and early G1 and a marker of progenitors differentiating into neurons, respectively, in the subgranular zone of the dentate gyrus (SZDG) using a type II diabetic model. At 6 weeks of age, Zucker lean control (ZLC) and Zucker diabetic fatty (ZDF) rats were put on a treadmill with or without running for 1 h/day/5 consecutive days at 22 m/min for 5 weeks. Body weight was significantly increased in the control (without running)-ZDF rats compared to that in the other groups. In the control groups blood glucose levels were increased by 392.7 mg/dl in the control-ZDF rats and by 143.3 mg/dl in the control-ZLC rats. However, in the exercise groups, blood glucose levels were similar between the exercise-ZLC and ZDF rats: The blood glucose levels were 110.0 and 118.2 mg/dl, respectively. Ki67 positive nuclei were detected in the SZDG in control and exercise groups. The number of Ki67 positive nuclei was significantly high in exercise groups compared to that in the control groups. In addition, Ki67 positive cells were abundant in ZLC groups compared to those in ZDF groups. DCX-immunoreactive structures in the control-ZDF rats were lower than that in the control-ZLC rats. In the exercise groups, DCX-immunoreactive structures (somata and processes with tertiary dendrites) and DCX protein levels were markedly increased in both the exercise-ZLC and ZDF rats compared to that in the control groups. These results suggest that a treadmill exercise reduces blood glucose levels in ZDF rats and increases cell proliferation and differentiation in the SZDG in ZLC and ZDF rats compared to those in control groups.     

Physical activity,dietary intake and quality of life during COVID-19 lockdown in patients awaiting transcatheter aortic valve implantation

BackgroundThe COVID-19 pandemic has led to a national lockdown in the Netherlands, which also affected transcatheter aortic valve implantation (TAVI) patients. The objective of the study was to describe physical activity, dietary intake and quality of life (QoL) in patients on the waiting list for TAVI pre-lockdown and during lockdown.MethodsConsecutive patients awaiting TAVI at the Amsterdam University Medical Centers, the Netherlands were included. Measurements were self-reported effect of lockdown, physical activity, dietary intake and QoL.ResultsIn total, 58 patients (median age 80, interquartile range (IQR) 76–84, 45% female) were observed pre-lockdown and 16 patients (median age 78, IQR 76–82, 25% female) during lockdown. Ten of the 16 patients during lockdown reported a decline in physical activity. However, we observed a median number of 5861 steps a day (IQR 4579–7074) pre-lockdown and 8404 steps a day (IQR 7653–10,829) during lockdown. Median daily protein intake was 69 g (IQR 59–82) pre-lockdown and 90 g (IQR 68–107) during lockdown. Self-rated health on a visual analogue scale was 63 points (IQR 51–74) pre-lockdown and 73 points (IQR 65–86) during lockdown.ConclusionsMore than half of the patients during lockdown reported less physical activity, while we observed a higher number of steps a day, a similar dietary intake and a higher QoL. Therefore, patients on the TAVI waiting list appeared to be able to cope with the lockdown measures.     

Intramuscular triacylglycerol and insulin resistance: Guilty as charged or wrongly accused?

The term lipotoxicity elicits visions of steatotic liver, fat laden skeletal muscles and engorged lipid droplets that spawn a number of potentially harmful intermediates that can wreak havoc on signal transduction and organ function. Prominent among these so-called lipotoxic mediators are signaling molecules such as long chain acyl-CoAs, ceramides and diacyglycerols; each of which is thought to engage serine kinases that disrupt the insulin signaling cascade, thereby causing insulin resistance. Defects in skeletal muscle fat oxidation have been implicated as a driving factor contributing to systemic lipid imbalance, whereas exercise-induced enhancement of oxidative potential is considered protective. The past decade of diabetes research has focused heavily on the foregoing scenario, and indeed the model is grounded in strong experimental evidence, albeit largely correlative. This review centers on mechanisms that connect lipid surplus to insulin resistance in skeletal muscle, as well as those that underlie the antilipotoxic actions of exercise. Emphasis is placed on recent studies that challenge accepted paradigms.     

Can we optimise the exercise training prescription to maximise improvements in mitochondria function and content?

Background

While there is agreement that exercise is a powerful stimulus to increase both mitochondrial function and content, we do not know the optimal training stimulus to maximise improvements in mitochondrial biogenesis.

Scope of review

This review will focus predominantly on the effects of exercise on mitochondrial function and content, as there is a greater volume of published research on these adaptations and stronger conclusions can be made.

Major conclusions

The results of cross-sectional studies, as well as training studies involving rats and humans, suggest that training intensity may be an important determinant of improvements in mitochondrial function (as determined by mitochondrial respiration), but not mitochondrial content (as assessed by citrate synthase activity). In contrast, it appears that training volume, rather than training intensity, may be an important determinant of exercise-induced improvements in mitochondrial content. Exercise-induced mitochondrial adaptations are quickly reversed following a reduction or cessation of physical activity, highlighting that skeletal muscle is a remarkably plastic tissue. Due to the small number of studies, more research is required to verify the trends highlighted in this review, and further studies are required to investigate the effects of different types of training on the mitochondrial sub-populations and also mitochondrial adaptations in different fibre types. Further research is also required to better understand how genetic variants influence the large individual variability for exercise-induced changes in mitochondrial biogenesis.

General significance

The importance of mitochondria for both athletic performance and health underlines the importance of better understanding the factors that regulate exercise-induced changes in mitochondrial biogenesis. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.