The immune response of healthy adults to a reduced dose of hepatitis B vaccine

Three hundred thirty-six medical personnel from hemodialysis centers were treated with three doses, 20 μg each, of the Merck hepatitis B vaccine (at 0, 1, and 6 months). Within 1 month after the first injection, 41% converted to anti-HBs positivity; after the second injection the conversion rate rose to 80–90%; and after the booster, to 96–98%. The later rate remained unchanged during the 18-month follow-up period. Only 2.8% of those vaccinated did not respond to the vaccine. The patterns of immune responses to 20-μg doses were found to be exactly the same as to 40-μg doses. It is suggested that reduced doses of vaccine should be as efficacious as the larger ones.     

高千伏摄影附加滤过与皮肤入射剂量相对关系的实验研究

目的：通过测量不同滤过条件下，体模入射剂量随滤过条件的变化确定高千伏X线摄影时的最佳附加滤过。材料与方法：利用X线剂量仪测量不同Al滤过时对应体模表面剂量的变化。结果与结论：通过适当增加附加滤过可以合理降低被检者皮肤剂量，120kV摄影时，附加滤过2.5mmAl是恰当的。     

线扫描直接数字化X线摄影原理与应用

目的 探讨线扫描直接数字化X线摄影的工作原理与实用价值。方法 以多丝正比室线扫描X线摄影系统为基础，分析线扫描直接数字化X线摄影的适用性。结果 线扫描成像技术克服了散射线造成的干扰，且探测灵敏度和精密度分辨率高。结论 线扫描成像技术适合于除了动态摄影以外的各种数字X线摄影，对我国常规X线摄影逐步实现数字化开辟了美好的前景。     

Efficiency of work performance and contraction velocity in isotonic tetani of frog sartorius

Mechanical work, ATP, ADP, PC, free creatine and lactate concentrations were determined on IAA poisoned frog sartorii tetanically stimulated in humidified N, at 10°C in isotonic conditions (0.25 or 0.45 P₀). Tetanus duration was 0.35 s, number of tetani was varied from 0 (rest) to 25 (exhaustion). The mechanical work performed per mole ATP+PC split (W _P ^* ) amounted on the average to 16.7 kJ/mol. It was observed, however, that w _p ^* increased from about 13 to about 24 kJ/mol with decreasing ATP concentration from about 2 (resting value) to about 1 mol/g and that this decrease in ATP was associated with a decrease of the shortening (and relaxation) speed of the muscle to about 30% of the values observed on the first tetanus. It is concluded that the thermodynamic efficiency of muscle contraction, calculated from the ratio of w _P ^* (measured) to the thermodynamic affinity (free energy change) of ATP hydrolysis (estimated) increases from about 0.3 to about 0.5 with decreasing ATP concentration and shortening speed.This work was supported by the Fonds National Suisse de la Recherche Scientifique, Grants 3.332.78 and 3.364.0.82     

Further studies on the chronotherapy of asthma with inhaled steroids: The effect of dosage timing on drug efficacy

Background: Chronotherapy studies with inhaled corticosteroids have shown optimal therapeutic benefit when steroids are administered four times per day (QID) or once daily at 3 PM.Objective: This study evaluated whether more convenient once-daily dosage times (8 AM and 5:30 PM) produce improvement in asthma equivalent to QID.Methods: Efficacy outcome measures included FEV₁, peak expiratory flow rates, bronchial responsiveness, use of β₂-agonists, nocturnal awakenings, and responses to a quality of life questionnaire. Systemic effects were blood eosinophil count, cortisol level, 24-hour urinary cortisol, and evaluation for oral candidiasis and dysphonia.Results: Baseline measurements for all three treatment groups were similar. For morning peak expiratory flow rate, significant improvement was seen for the QID group (p = 0.001) and the 5:30 PM group (p = 0.003), but not the 8 AM group (p = 0.75). For evening peak expiratory flow rate, significant improvement was seen for the QID group (p = 0.005) and the 5:30 PM group (p = 0.01), but not for the 8 AM group (p = 0.47). There were significant improvements in all other outcome variables for each group except PC₂₀. There was a significant improvement in PC₂₀ only in the QID group. The systemic effects of the three regimens were comparable.Conclusion: Dosing of inhaled steroid at 5:30 PM had no increased systemic effects and produced efficacy similar to QID dosing. Dosing at 8 AM did not produce results consistently comparable to QID dosing. Optimal once-daily dosing of inhaled steroid is between 3 PM and 5:30 PM.     

The functional organization of the intraparietal sulcus in humans and monkeys

In macaque monkeys, the posterior parietal cortex (PPC) is concerned with the integration of multimodal information for constructing a spatial representation of the external world (in relation to the macaque's body or parts thereof), and planning and executing object-centred movements. The areas within the intraparietal sulcus (IPS), in particular, serve as interfaces between the perceptive and motor systems for controlling arm and eye movements in space. We review here the latest evidence for the existence of the IPS areas AIP (anterior intraparietal area), VIP (ventral intraparietal area), MIP (medial intraparietal area), LIP (lateral intraparietal area) and CIP (caudal intraparietal area) in macaques, and discuss putative human equivalents as assessed with functional magnetic resonance imaging. The data suggest that anterior parts of the IPS comprising areas AIP and VIP are relatively well preserved across species. By contrast, posterior areas such as area LIP and CIP have been found more medially in humans, possibly reflecting differences in the evolution of the dorsal visual stream and the inferior parietal lobule. Despite interspecies differences in the precise functional anatomy of the IPS areas, the functional relevance of this sulcus for visuomotor tasks comprising target selections for arm and eye movements, object manipulation and visuospatial attention is similar in humans and macaques, as is also suggested by studies of neurological deficits (apraxia, neglect, Bálint's syndrome) resulting from lesions to this region.     

An Experimental Comparison of Flat-Panel Detector Performance for Direct and Indirect Systems (Initial Experiences and Physical Evaluation)

The purpose of this work was to compare direct and indirect detectors in terms of their system linearity, presampled modulation transfer function (MTF), Wiener spectrum (WS), noise equivalent quanta (NEQ), and power spectrum. Measurements were made on two flat-panel detectors, GE Revolution XR/d (indirect) and Shimadzu Safire (direct) radiographic techniques. The system linearity of the systems was measured using a time-scale method. The MTF of the systems was measured using an edge method. The WS of the systems was determined for a variable range of exposure levels by two-dimensional Fourier analysis. The NEQ was assessed from the measured MTF, WS, and estimated ideal signal-to-noise ratios. Power spectrum analyzed the chest phantom within artificial lesions. System linearity was excellent for the direct systems. For the direct system, the MTF was found to be significantly higher than that for the indirect systems. For the direct system, the WS was relatively uniform across all frequencies. In comparison, the indirect system exhibited a drop in the WS at high frequencies. At lower frequencies, the NEQ for the indirect system was noticeably higher than for the direct system. Power spectrum for the direct system was relatively flat and similar to that for white noise. The indirect system exhibited significant reduction at high spatial frequencies. In general, the direct systems exhibit improved image quality over indirect systems at comparable exposure dose.     

High energy phosphate utilization for work production and tension maintenance in frog muscle

Frog (Rana esculenta, L.) gastrocnemii (161 pairs) or sartorii (8 pairs) were stimulated by intermittent tetani at 10°C (20 Hz, supramaximal intensity, N₂ atmosphere) isometrically (IM) or isotonically (IT) for various durations (6–30 s) at different tensions (0.05–1.00 P₀=maximal IM tension at resting length,l _o). The energy expenditure (E) was measured from ATP and phosphocreatine breakdown and the high energy phosphate equivalent of lactic acid production. Both in IM and IT conditions,E was found to be a linear function of the summated tetanus duration (t):E=a+b t, whereb is the energy cost of tension maintenance. For the gastrocnemius, both in IM and IT,b was independent of the tension developed and equal to 0.45 mol P · g^–1 · s^–1, whereas for the sartoriusb was tension-dependent, varying between 0.58 and 0.28 mol P · g^–1 · s^–1 for P₀ and 0.18 P₀, respectively. The constancy of theb value in muscles with pennate structure may be tentatively attributed, at least in part, to the greater internal energy dissipation, regardless of the tension developed. The terma of the above equation is due to all time-independent processes of muscle contraction, i.e.: (1) activation energy; (2) internal work and (3) external work (in IT only). Based on the measured value ofa and on the work performed, the mechanical equivalent of P splitting was calculated as 17.7 kJ · mol^–1, a figure close to that previously obtained on frog sartorius (16.7 kJ · mol^–1) and dog gastrocnemius (19.2 kJ · mol^–1) When taking into account the energy due to the activation processes, the calculated net mechanical equivalent of P splitting amounted to 25.5 kJ · mol^–1.     

鼻咽癌调强放射治疗的剂量验证

目的:对接受调强放射治疗的鼻咽癌病人进行治疗前的剂量验证.材料和方法:利用电离室,胶片和验证模体对39个接受调强放射治疗的鼻咽癌患者,在治疗开始前进行绝对剂量和相对剂量验证.绝对剂量验证主要在两个位置进行:一个在等中心位置,另一个在离等中心4cm靠进腮腺的位置.相对剂量主要用体模对单野和整个计划的剂量分布进行验证.将得到的剂量分布利用分析软件与计划中的剂量分布进行分析比较.利用剂量偏差(dose difference)、吻合距离(distance to agreement,DTA)、γ指数等参数来测量剂量验证的偏差.结果:中心点和腮腺边上点的平均绝对误差分别为2.70%和3.03%.对于测量感兴趣区域(ROI,region of interested)的相对误差的测量,90%的测量都在设定的标准(3%,3 mm)之内,对于未能达到剂量偏差和间距偏差标准的区域,结合γ分析后一般也可以得到满意的结果.结论:验证结果表明实际测量剂量分布与计划计算的剂量分布符合的相当理想.