固相法合成心肌兴奋肽及其类似物

用Boc-和Tos-基团分别保护氨基和侧链胍基,以1%交联度聚苯乙烯二苯甲氨基树脂为载体,用DCC固相法合成肽,HF断裂肽树脂键和去除侧链保护基团,粗产物经高效液相层析纯化,合成了心肌兴奋肽Phe-Met-Arg-Phe-NH_2及其类似物Phe-Pro-Arg-Phe-NH_2,并观察了此二种肽对大鼠血压和心率的影响。     

二维半导体探测器阵列在多叶准直器日常质量保证中的应用

目的 建立利用半导体探测器阵列检测多叶准直器(MLC)叶片定位误差的方法,用于MLC的日常质量保证。方法 在MapCheck半导体探测器阵列上,相邻行探测器是错开半个探测器间距分布的。针对这种分布特点,设计了台阶式叶片位置模式,代替胶片测量常用的篱笆式(picket fence)叶片位置模式,作为叶片位置参考模式。在参考模式的基础上,人为引入不同大小的叶片位置误差,得到一组新的叶片位置模式——叶片位置校准模式。依次照射参考模式和校准模式,得到每一个探测器测量剂量与叶片位置误差的关系曲线。该曲线作为测量叶片位置误差的校准曲线。在进行MLC日常质量保证时,只需定期照射叶片位置参考模式,就可得到定量的叶片位置误差。结果 新方法在一个配置40对MLC的加速器上进行了测试(Elekta Precise)。篱笆式叶片位置模式一次检测160个叶片位置,而台阶式叶片位置模式一次检测240个位置, 检测效率提高50%;对于同样的1mm叶片误差,前后两种模式的剂量变化分别是17%和25%,因此测量灵敏度提高8%。结论 建立了一种新的定量的MLC日常QA方法。通过重新设计叶片位置模式,新方法提高了实施效率和测量灵敏度。     

Bronchoscopic management of airway obstruction in pediatric endobronchial tuberculosis

The present report describes a case of severe airway obstruction caused by endobronchial tuberculosis in an 11-year-old girl who was successfully treated by bronchoscopic balloon dilation. This case illustrates the insidious presentation and the increasingly important role of bronchoscopic intervention in the management of endobronchial tuberculosis. In addition, a brief literature review of the condition in the pediatric age group is included.     

Rearrangement of the T cell receptor gamma-chain gene in childhood acute lymphoblastic leukemia

We analyzed rearrangements of the T cell receptor gamma-chain (T gamma) gene as well as rearrangements of the T cell receptor beta-chain (T beta) gene and immunoglobulin heavy-chain (IgH) gene in 68 children with acute lymphoblastic leukemia (ALL). All 15 patients with T cell ALL showed rearrangements of both T beta and T gamma genes. Twenty-four of 53 non-T, non-B ALL patients (45%) showed T gamma gene rearrangements and only 14 of these also showed T beta gene rearrangements. Only a single patient rearranged the T beta gene in the absence of T gamma gene rearrangement. The rearrangement patterns of the T gamma gene in non-T, non-B ALL were quite different from those observed in T cell ALL, as 20 of 23 patients retained at least one germline band of the T gamma gene. In contrast, all T cell ALL patients showed no retention of germline bands. These data indicate that rearrangement of the T gamma gene is not specific for T cell ALL. Further, the results also suggest that T gamma gene rearrangement precedes T beta gene rearrangement. The combined analysis of rearrangement patterns of IgH, T beta, and T gamma genes provides new criteria for defining the cellular origin of leukemic cells and for further delineation of leukemia cell heterogeneity.     

The Role of Serotonin (5-HT) in Behavioral Control: Findings from Animal Research and Clinical Implications

The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research.     

Insulin receptors on leukemia and lymphoma cells

Tumor cells obtained from leukemia and lymphoma patients were investigated for specific insulin receptors. Using radioactive 125I- labeled insulin, specific insulin binding sites were demonstrated on most acute lymphocytic leukemia (ALL) and acute myelocytic leukemia (AML) cells, including acute promyelocytic leukemia (APL), chronic myelocytic leukemia (CML), and acute monocytic leukemia (AMoL) cells. Insulin receptors were not found on chronic lymphocytic leukemia (CLL) and malignant lymphoma (ML) cells. Specific insulin binding sites were also found on monocytes and thymocytes after treatment with phytohemagglutinin (PHA-P), but not on inactivated tonsil cells, peripheral blood lymphocytes, or thymocytes. There was no inverse correlation between the content of insulin receptors and the basal level of circulating insulin. These data suggest that the insulin receptor may be a new marker of acute leukemia and chronic myelocytic leukemia.     

Influence of Bleeding Risk on Outcomes of Radial and Femoral Access for Percutaneous Coronary Intervention: An Analysis From the GLOBAL LEADERS Trial

BackgroundRadial artery access has been shown to reduce mortality and bleeding events, especially in patients with acute coronary syndromes. Despite this, interventional cardiologists experienced in femoral artery access still prefer that route for percutaneous coronary intervention. Little is known regarding the merits of each vascular access in patients stratified by their risk of bleeding.MethodsPatients from the Global Leaders trial were dichotomized into low or high risk of bleeding by the median of the PRECISE-DAPT score. Clinical outcomes were compared at 30 days.ResultsIn the overall population, there were no statistical differences between radial and femoral access in the rate of the primary end point, a composite of all-cause mortality, or new Q-wave myocardial infarction (MI) (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.42-1.15). Radial access was associated with a significantly lower rate of the secondary safety end point, Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding (HR 0.55, 95% CI 0.36-0.84). Compared by bleeding risk strata, in the high bleeding score population, the primary (HR 0.47, 95% CI 0.26-0.85; P = 0.012; P_interaction = 0.019) and secondary safety (HR 0.57, 95% CI 0.35-0.95; P = 0.030; P_interaction = 0.631) end points favoured radial access. In the low bleeding score population, however, the differences in the primary and secondary safety end points between radial and femoral artery access were no longer statistically significant.ConclusionsOur findings suggest that the outcomes of mortality or new Q-wave MI and BARC 3 or 5 bleeding favour radial access in patients with a high, but not those with a low, risk of bleeding. Because this was not a primary analysis, it should be considered hypothesis generating.     

Effects of a home visiting program for older people with poor health status: a randomized, clinical trial in The Netherlands

OBJECTIVES: To evaluate the effectiveness of a home visiting program on health-related measures in a population of older people with poor health status.
DESIGN: Randomized, clinical trial.
SETTING: Community-dwelling citizens in the Netherlands.
PARTICIPANTS: Three hundred thirty people aged 70 to 84 randomly assigned to an intervention group (n=160) or a control group (n=170).
INTERVENTION: Eight home visits, lasting 1 hour or more, with telephone follow-up, over an 18-month period, conducted by experienced home nurses under supervision of a public health nurse; key elements of the (systematic) visits were assessment of health problems and risks, advice, and referral to professional and community services.
MEASUREMENTS: Self-rated health, functional status, quality of life, and changes in self-reported problems.
RESULTS: No differences were found between the intervention and control group in these and other outcome measures at the end of the intervention period (18 months).
CONCLUSION: The home visiting program did not appear to have any effect on the health status of older people with poor health and are probably not beneficial for such persons.     

Percutaneous transradial coronary palmaz-schatz stent implantation,guided by intravascular ultrasound

Intravascular ultrasound (IVUS) allows accurate assessment of stent deployment, its use being confined to the use of 8 French (F) guiding catheters. We evaluated the feasibility of combining transradial artery Palmaz-Schatz stent implantation through 6F guiding catheters with IVUS for assessment of stent diameter after delivery at moderate inflation pressures (10-12 atmospheres [atm]) with compliant balloons and after high pressure dilatations with balloons of intermediate compliance. In 8 consecutive patients, 12 stents were delivered with Scimed® Express^TM balloon catheters at 10-12 atm followed by IVUS (EndoSonics® CathScanner; Visions® FX 3.5F 20 MHz transducer). An ultrasound study was repeated after high pressure dilatations (16-20 atm) with Schneider® Magical Speedy^TM balloon catheters. The balloon diameters were derived from manufacturer provided specifications. In all patients the transducer could easily be advanced through the guiding catheters. Reference diameter of the stented segment was 3.7 ± 0.5 mm (2.7-4.5) and the diameter of Scimed® Express^TM balloons during inflation was 4.0 ± 0.3 mm (3.6-4.7). Stent diameter was 3.0 ± 0.1 mm (2.8-3.2) (P < 0.001 compared to the reference and the balloon diameter). The diameter of the Schneide® Magical Speedy^TM balloons at secondary dilatations with 16 ± 3 atm (14-20) was 4.1 ± 0.4 mm (3.3-4.5) (P = 0.50 compared to the initial balloon diameter). Final stent diameter was 3.3 ± 0.4 mm (2.9-4.1) (P = 0.02 compared to the initial stent diameter). All stents were symmetrically deployed and well apposed. No damage to vessel or stents was detected after passage of the transducer. Thus ultrasound guided stenting via 6F guiding catheters is feasible, and high pressure dilatations with balloons of intermediate compliance results in better stent expansion than after 10-12 atm inflations with compliant balloon catheters.