Transfusion-associated graft-versus-host disease in immunocompetent patients: report of a fatal case associated with transfusion of blood from a second-degree relative, and a survey of predisposing factors

A patient without evident immune deficiency who received a transfusion of blood from a second-degree family member developed fatal transfusion- associated graft-versus-host disease (TA-GVHD). The donor was homozygous for an HLA haplotype for which the recipient was heterozygous (one-way HLA match). All 39 reported cases of TA-GVHD in immunocompetent patients were reviewed to ascertain the predisposing factors and to define the indications for irradiating blood for this population. HLA typing was described in 15 cases; in 13, including seven related and six unrelated donors, a one-way HLA match was present. Thirty-one (79%) of the 39 cases were reported from Japan (and 196 other cases are cited in the Japanese literature), but a one-way HLA match among unrelated donors at HLA-A, -B, -DR loci is only approximately two to four times more likely in Japanese persons than in whites. Fresh blood (< 96 hours old) was used in 29 (94%) of the 31 cases reported from Japan and in 33 (87%) of 38 cases overall (in one case, the age of the blood used was not reported). Thus, factors that appear to predispose to TA-GVHD in immunocompetent patients are a one- way HLA match, fresh blood, and, possibly, Japanese ancestry. Irradiating cellular blood components from all blood relatives of transfusion recipients will not completely eliminate the risk of TA- GVHD.     

低氧训练对下丘脑-垂体-肾上腺皮质轴内分泌相关激素的影响

目的:总结低氧训练对下丘脑-垂体-肾上腺皮质轴内分泌相关激素的影响,为科学运动训练提供依据。资料来源:应用计算机检索中国期刊全文数据库1994-01/2006-10的相关文章,检索词"低氧,低氧训练,下丘脑-垂体-肾上腺,激素",并限定文章语言种类为中文。并应用计算机检索美国国立医学图书馆NCBI1980-01/2006-10的相关文章,检索词"Hypoxic Training,organism endocrine system,hormone",并限定文章语言种类为English。资料选择:对资料进行初审,选取低氧训练与下丘脑-垂体-肾上腺分泌的相关激素有关的文献,并作初步分类,同类文献首选近年发表的核心期刊文章。排除重复及综述类文献。资料提炼:共收集到95篇相关文章,其中56篇属于重复及综述类文献,对符合标准38篇文献进行分析整理。资料综合:①高海拔状态下机体对低氧产生应激反应,表现为下丘脑-垂体-肾上腺皮质轴的适应性运转,血中促肾上腺皮质激素浓度增加,以调节机体对应激刺激的适应能力,同时使促肾上腺皮质激素释放因子分泌增加。②高原训练后,睾酮和皮质醇的变化都较明显,其总体变化均趋于降低,睾酮/皮质醇值有升有降,从一定意义上反映了机体的机能状况与疲劳积累程度。③低氧还引起大鼠血浆β-内啡肽浓度升高,可使心房钠尿素增加、前列腺素增加、血管内皮素分泌增加及抑制血管内皮舒张因子的分泌。结论:激素对机体的新陈代谢、生长发育、各种功能活动以及维持内环境稳态等方面发挥重要的调节作用,低氧训练对机体激素的影响一直应该受到人们的关注。     

Glycolysis supports calcium uptake by the sarcoplasmic reticulum in skinned ventricular fibres of mice deficient in mitochondrial and cytosolic creatine kinase

Several works have shown the importance of the creatine kinase (CK) system for cardiac energetics and Ca2+ homeostasis. Nevertheless, CK-deficient mice have cardiac function close to normal, at least under conditions of low or moderate workload. To characterize possible adaptive changes of the sarcoplasmic reticulum (SR) and potential role of glycolytic support in cardiac contractility we used the skinned fibre technique to study properties of the SR and myofibrils, in control and muscle-type homodimer (MM-/mitochondrial-CK)-deficient mice. In control fibres, SR Ca2+ loading with ATP and phosphocreatine (solution PL) was significantly better than loading with ATP alone (solution AL), as determined by analysis of caffeine-induced tension transients. Loading in the presence of ATP and glycolytic intermediates (solution GL) was not significantly different from solution PL. These data indicate that Ca2+ uptake by the SR in situ depends on a local ATP:ADP ratio that is controlled by both CK and glycolytic enzymes. In CK-deficient mice, Ca2+ loading was impaired in solution PL due to the absence of CK. In solution GL, loading was significantly increased, such that calculated Ca2+ release parameters were normalized to those in control fibres in solution PL. In CK-deficient mice, fibre kinetic parameters of tension recovery were impaired after quick stretch in solution PL and were not improved in solution GL. These results show that in CK-deficient mice, at least under basal conditions, glycolysis can replace the CK system in fueling the SR Ca2+ ATPase, but not the myosin ATPase, and may in part explain the limited phenotypic alterations seen in the hearts of these mice.     

Bone mineral density and bone fracture in male patients receiving long-term suppressive levothyroxine treatment for differentiated thyroid carcinoma

Studies on the effect of exogenous subclinical thyrotoxicosis on bone mineral density (BMD) in male patients treated with suppressive doses of levothyroxine for differentiated thyroid carcinoma (DTC) are not conclusive. In order to evaluate BMD (in femoral neck, lumbar spine, and distal radius) and bone fractures in men under long-term suppressive treatment with levothyroxine for DTC, we conducted a cross-sectional, retrospective study in 33 Caucasian men (mean?±?SD age: 56?±?14?years) under treatment for DTC. The control group comprised 33 healthy age- and body mass index-matched male volunteers. BMD was assessed by dual-energy X-ray absorptiometry (DXA). Bone turnover biomarkers (calcium, phosphate, alkaline phosphatase, PTH, vitamin D, urinary calcium, and N-Telopeptide/creatinine index) and testosterone were determined. Previous bone fractures were evaluated with a questionnaire and X-ray images of thoracic and lumbar vertebrae. Patients were treated for a mean duration of 15?±?5?years. No differences were found between patients and controls in bone turnover biomarkers or areal BMD, T-scores or Z-scores in all sites evaluated. No earlier fractures or pain episodes were registered in either group and the incidence of asymptomatic vertebral fractures did not differ significantly between patient (18.8%) and control groups (16.7%), (P?=?0.9). In conclusion, long-term suppressive treatment with levothyroxine in men with DTC does not appear to exert deleterious effects on bone mineral density or increase the prevalence of fracture.     

Effects of the Administration of Feedback on Performance of the Bmx Cycling Gate Start

The aim of the present study was to determine the effect of the administration of external feedback (FB) on the time used to execute the gate start skill in BMX cycling discipline. The sample used was n = 6 riders from the Spanish national team (19.3 ± 2.1 years). An intragroup experimental design with repeated measures was used to compare the evolution of the skill developed by the participants before and after treatment, as well as the degree of retention of the possible learning. The results showed that there were no significant differences between the 2 first pre-test sessions (PRE), nor between any of the other treatment, post-test or re-test sessions (TREAT, POS and RET, respectively). Nevertheless, significant differences were observed between either of the PRE sessions and any of the TREAT, POS or RET sessions (p ≤ 0.028), showing a significant reduction of the time needed to perform this skill after TREAT (1.264 ± 0.045 ms in PRE, 1.047 ± 0.019 ms in POS, and 1.041 ± 0.021 ms in RET). In conclusion, the use of audiovisual FB and cognitive training of the skill can result in a significant improvement in the execution of the gate start in BMX reducing the time to develop the task.

Key points

• This work provides a practical application of many studies developed around teaching-learning technique in sport. In those studies this kind of applications were suggested as necessary.
• All the recent theories are applied in the real sport context, and using elite athletes.
• A successful program is proposed to be used by coaches and athletes just following a few simple guidelines, and this can be a really useful tool to follow.

Key words: BMX, cycling, gate start, feedback, motor learning