Phosphocreatine resynthesis during recovery in different muscles of the exercising leg by 31P‐MRS

To investigate the high‐energy phosphate metabolism by ³¹P‐nuclear magnetic resonance spectroscopy during off‐transition of exercise in different muscle groups, such as calf muscles and biceps femoris muscles, seven male long‐distance runners (LDR) and nine untrained males (UT) performed both submaximal constant and incremental exercises. The relative exercise intensity was set at 60% of the maximal work rate (60%Wmax) during both knee flexion and plantar flexion submaximal constant load exercises. The relative areas under the inorganic phosphate (P_i) and phosphocreatine (PCr) peaks were determined. During the 5‐min recovery following the 60%Wmax, the time constant for the PCr off‐kinetics was significantly faster in the plantar flexion (LDR: 17.3 ± 3.6 s, UT: 26.7 ± 6.7 s) than in the knee flexion (LDR: 29.7 ± 4.7 s, UT: 42.7 ± 2.8 s, P < 0.05). In addition, a significantly faster PCr off‐kinetics was observed in LDR than in UT for both exercises. The ratio of P_i to PCr (P_i/PCr) during exercise was significantly lower during the plantar flexion than during the knee flexion (P < 0.01). These findings indicated that the calf muscles had relatively higher potential for oxidative capacity than that of biceps femoris muscles with an association of training status.     

Spectrally selective 3D TSE imaging of phosphocreatine in the human calf muscle at 3 T

Quantitative information about concentrations of several metabolites in human skeletal muscle can be obtained through localized ³¹P magnetic resonance spectroscopy methods. However, these methods have shortcomings: long acquisition times, limited volume coverage, and coarse resolution. Significantly higher spatial and temporal resolution of imaging of single metabolites can be achieved through spectrally selective three‐dimensional imaging methods. This study reports the implementation of a three‐dimensional spectrally selective turbo spin‐echo sequence, on a 3T clinical system, to map the concentration of phosphocreatine in the human calf muscle with significantly increased spatial resolution and in a clinically feasible scan time. Absolute phosphocreatine quantification was performed with the use of external phantoms after relaxation and flip angle correction of the turbo spin‐echo voxel signal. The mean ± standard deviation of the phosphocreatine concentration measured in five healthy volunteers was 29.4 ± 2.5 mM with signal‐to‐noise ratio of 14:1 and voxel size of 0.52 mL. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.     

小牛胸腰椎解剖、生物力学研究及其临床意义

目的　测量小牛胸腰椎相关解剖数据并测试其生物力学性能 ,探讨其作为胸腰椎前路内固定模型的可行性。方法　采集 1周以内的新鲜小牛胸腰椎脊柱标本 2 0具 ,测量椎体及椎间盘的最大横径、矢状径和前部高度。测试屈曲、伸展、侧屈及扭转状态下的载荷 -应变、载荷 -位移关系以及最大载荷时的应力强度及轴向刚度 ,并进行极限力学性能测试。结果　小牛胸腰椎椎体及椎间盘矢径、横径、高度自T10 至L5逐渐递增 ,椎体横径与矢径之比约为 1∶1,其T10 ～L5段椎间盘高度之和与椎体高度比值为 1∶0 .9。小牛胸腰椎载荷 -应变及载荷 -位移关系呈线性变化 ,生理载荷下屈曲、伸展及侧屈状态下的应力强度分别为 (2 .86± 0 .2 4 )N/mm2 ,(2 .17± 0 .2 0 )N/mm2 ,(5 .2 9± 0 .5 0 )N/mm2 。屈曲、伸展、侧屈及扭转状态下的轴向刚度分别为 (37.13± 4 .30 )N/mm ,(35 .38± 4 .2 0 )N/mm ,(34.5 6± 4 .2 0 )N/mm ,(5 1.6 9± 1.6 2 )N/mm。结论　小牛胸腰椎形态及大小可满足前路内固定模型的需要 ,以小牛标本作为体外非破坏性生物力学实验模型具有可行性。     

Reversed anterolateral thigh adipofascial flap for knee and proximal calf defects

BACKGROUND: Reconstruction of defects involving the knee and proximal one third of the lower leg presents a challenging problem in plastic surgery. AIM: To evaluate the reversed anterolateral thigh adipofascial flap for covering such defects. METHODS: Between September 2006 and May 2007, one man and four women with defects around the knee and upper calf underwent reconstruction with reversed anterolateral thigh adipofascial flaps. The patients' average age was 45 years (25-72 years). The size of the transferred flap ranged from 6cmx8cm to 12cmx13cm. RESULTS: Four flaps with overlying skin grafts healed uneventfully; one skin graft showed minor necrosis due to haematoma, but the adipofascial flap survived well. Postoperatively the appearance of the reconstructive flap was acceptable. CONCLUSIONS: The reversed anterolateral thigh adipofascial flap is an effective option for covering defects of the knee and proximal calf.     

A型肉毒毒素注射小腿塑形的临床应用探讨

目的：探讨A型肉毒毒素注射小腿塑形的效果。方法：选取11名小腿肌性肥大求美者,双侧小腿注射A型肉毒毒素300～400U,测量术前和术后3个月小腿最大周径。结果：术后3个月小腿最大周径缩小1.62±0.88cm,缩小比例为4.65%±2.42%,术前术后差异有统计学意义（P〈0.01）。结论：A型肉毒毒素能有效地减少小腿周径,小腿塑形效果满意。     

孤立性小腿深静脉血栓的超声诊断

目的　探讨孤立性小腿深静脉血栓的声像图特点及超声诊断方法。方法　应用彩色多普勒超声检查小腿肌肉内深静脉 (比目鱼肌静脉、腓肠肌静脉 )、胫后静脉、腓静脉、胫前静脉 ,以及静脉以上近端深静脉是否有血栓形成。结果　检出的 13例孤立性小腿深静脉血栓中 ,77%为小腿肌肉内深静脉受累 ,少数为腓静脉及胫后静脉受累 ,未发现胫前静脉单独受累者 ;比目鱼肌内的单支静脉血栓为最常见的类型 ,且半数合并近端深浅静脉返流。结论　超声检查能够有效地检出孤立性小腿深静脉血栓病变 ,小腿深静脉特别是肌肉内深静脉应包括在下肢深静脉检查常规之中。     

Target-mediated clearance and bio-distribution of a monoclonal antibody against the Kunitz–type protease inhibitor 2 domain of Tissue Factor Pathway Inhibitor

Introduction

A humanised monoclonal antibody, concizumab, that binds with high affinity to the Kunitz-type protease inhibitor (KPI) 2 domain of human tissue factor pathway inhibitor (TFPI) is in clinical development. It promotes coagulation by neutralising the inhibitory function of TFPI and may provide a subcutaneous prophylaxis option for patients with haemophilia. We aimed to study biodistribution and pharmacokinetics (PK) of concizumab.

Materials and Methods

Blockage of cellular TFPI by concizumab was measured by tissue factor/Factor VIIa-mediated Factor X activation on human EA.hy926 cells. Biodistribution of concizumab was analysed in rabbits by immunohistology, and the PK was measured in rabbits and rats.

Results and Conclusions

Concizumab bound to cell surface TFPI on EA.hy926 cells and neutralised TFPI inhibition of Factor X activation. The antibody cross-reacted with rabbit TFPI, but not with rat TFPI, allowing for comparative PK studies. PK data in rats described a log-linear profile typical for a non-binding antibody, whereas PK data in rabbits revealed a non-linear, dose-dependent profile, consistent with a target-mediated clearance mechanism. Immunohistology in rabbits during target-saturation showed localisation of the antibody on the endothelium of the microvasculature in several organs. We observed a marked co-localisation with endogenous rabbit TFPI, but a negligible sub-endothelial build-up. Concizumab binds and neutralises the inhibitory effect of cell surface-bound TFPI. The PK profile observed in rabbits is consistent with a TFPI-mediated drug disposition. Double immunofluorescence shows co-localisation of the antibody with TFPI on the endothelium of the microvasculature and points to this TFPI as a putative target involved in the clearance mechanism.     

Reshaping of T-lymphocyte compartment in adult prepubertaly ovariectomised rats: A putative role for progesterone deficiency

This study explores the role of ovarian hormones in the phenotypic shaping of peripheral T-cell pool over the reproductive lifespan of rats. For this purpose, 2-month-old prepubertally ovariectomised (Ox) rats, showing oestrogen and progesterone deficiency, and 11-month-old Ox rats, exhibiting only progesterone deficiency, were examined for thymus output, and cellularity and composition of major TCRαβ+ peripheral blood lymphocyte (PBL) and splenocyte subsets. Although ovariectomy increased thymic output in both 2- and 11-month-old rats, the count of both CD4+ and CD8+ PBLs and splenocytes increased only in the former. In the blood and spleen of 11-month-old Ox rats only the count of CD8+ cells increased. Although ovariectomy affected the total CD4+ count in none of the examined compartments from the 11-month-old rats, it increased CD4+FoxP3+ PBL and splenocyte relative proportions over those in the age-matched controls. The age-related differences in the cellularity and the major subset composition in Ox rats were linked to the differences in the ovarian steroid hormone levels registered in 2- and 11-month-old rats. The administration of progesterone to Ox rats during the seven days before the sacrificing confirmed contribution of this hormone deficiency to the ovariectomy-induced changes in the TCRαβ+ PBL and splenocyte pool from 11-month-old rats. The expansion of the CD8+ splenocyte subset in the 11-month-old Ox rats reflected increases in cellularity of memory and, particularly, naïve cells. This was due to greater thymic output of CD8+ cells and homeostatic proliferation than apoptosis in 11-month-old Ox rats when compared with age-matched sham-Ox control rats. The homeostatic changes within CD8+ splenocyte pool from 11-month-old Ox rats, most likely, reflected the enhanced splenic IL-7 and TGF-β mRNA expression. Overall, in adult female rats, circulating oestrogen and progesterone provide maintenance of T-cell counts, a diversity of T-cell repertoire, and the main T-cell subset composition in the periphery. Progesterone deficiency affects mainly the CD8+ lymphocyte compartment through increasing thymic CD8+ cell export and upsetting homeostatic regulation within the CD8+ splenocyte pool. These alterations were reversible through progesterone supplementation.     

Reduced oxidative muscle metabolism in chronic fatigue syndrome

The purpose of this study was to determine if chronic fatigue syndrome (CSF) is characterized by abnormalities in oxidative muscle metabolism. Patients with CFS according to Centers for Disease Control (CDC) criteria (n = 22) were compared to normal sedentary subjects (n = 15). CFS patients were also tested before and 2 days after a maximal treadmill test. Muscle oxidative capacity was measured as the maximal rate of postexercise phosphocreatine (PCr) resynthesis using the ADP model (V_max) in the calf muscles using ³¹P magnetic resonance spectroscopy. V_max was significantly reduced in CFS patients (39.6 ± 2.8 mmol/L/min, mean ± SE) compared to controls (53.8 ± 2.8 mmol/L/min). Two days postexercise there was no change in resting inorganic phosphate (Pi)/PCr or V_max in the CFS patients (n = 14). In conclusion, oxidative metabolism is reduced in CFS patients compared to sedentary controls. In addition, a single bout of strenuous exercise did not cause a further reduction in oxidative metabolism, or alter resting Pi/PCr ratios. © 1996 John Wiley & Sons, Inc.