Peripheral nerve stimulation during MRI: Effects of high gradient amplitudes and switching rates

The application of high gradient amplitudes and switching rates for MRI and spectroscopy, resulting in short rise times for the gradient field and high changes of the magnetic flux density in the patient, is known to possibly evoke peripheral nerve stimulation (PNS) in patients. These effects have been studied on 20 volunteers under different experimental circumstances. The results of these measurements are partially in line with earlier findings reported in the literature. New information is found for the dependence of the PNS threshold level as a function of the rise time of the gradient waveform. The PNS threshold level, expressed in terms of dB/dt, is found to be proportional with t^?05, where t is the switch time for the gradients. Indications are found that |B|, the modulus of the gradient vector field, is more closely related to the PNS threshold level than B_z, the imaging component of the gradient field. From the experiments, it is furthermore concluded that only for the imaging protocols characterized by the application of long bipolar repetitive gradient pulse trains, such as echo-planar imaging, PNS is expected at the reported threshold levels. For the protocols based on spin echo, turbo spin echo, inversion recovery, fast field echo, etc., characterized by shorter gradient pulse trains, the threshold levels are expected to be much higher.     

Quantitative thallium-201 scintigraphy after dipyridamole infusion combined with low level exercise in healthy volunteers

To establish test specific normal limits for quantitative analysis of uptake and washout of ²⁰¹Tl after dipyridamole infusion combined with low level exercise, 20 healthy volunteers were studied with low likelihood of coronary artery disease (CAD) assessed by a stepwise probability analysis based on age, sex, symptoms, resting electrocardiogram, and exercise electrocardiography. Likelihood of CAD in these volunteers was calculated as 1%. After dipyridamole infusion combined with low level exercise, one volunteer complained of headache; no other side effects were observed. There were no chest pain complaints. Maximal hemodynamic changes were achieved during the 6th and 7th min of the test. No ST segment depression was recorded. Visual analysis of the ²⁰¹Tl scintigrams was normal in all volunteers. Mean regional washout at 4 h was 44.37%±2.11%. The regional washout in the 70° LAO view (46.65%±1.10%) was significantly higher than in the anterior and 30° LAO views (43.44%±1.50% and 43.02%±1.45%, respectively). Profiles of uptake and washout of ²⁰¹Tl were different after dipyridamole infusion combined with low level exercise as compared to maximal exercise. Thus, in quantitative analysis of ²⁰¹Tl scintigraphy after dipyridamole infusion in conjunction with low level exercise as applied in the present study, it is mandatory to use normal limits of uptake and washout of ²⁰¹Tl derived from healthy volunteers who underwent the same combined protocol.     

LeisureIRecreation Needs of Hospitalized Elderly:

Leisure/Recreation interests and needs do not change much as a person grows older, or as a person becomes hospitalized. Certainly opportunities do change as internal and external limitations are imposed. Patients' interests and needs are going to be highly individualized, just as our own are. For this reason, variety and flexibility need to be built into the environment. Nonetheless, the major factor in providing sensitive human care continues to be the personnel providing that care. A management philosophy which nourishes an interdisciplinary model and one which supports quality of life, as well as extension of years, will be essential in any setting.     

定量CT分析年龄、腹部脂肪与骨密度的关系

目的采用定量CT(QCT)探讨腹部脂肪及骨密度(BMD)随年龄变化的规律及腹内脂肪(VAT)与BMD的相关性。资料与方法选取行低剂量胸部CT联合QCT检查的健康体检者2442例,其中男1522例,女920例,根据年龄分为5个年龄段:30~39、40~49、50~59、60~69、70~90岁。采用QCT测量L2中心层面腹部总脂肪(TAT)、VAT、皮下脂肪(SAT)及腰椎BMD。分析不同性别各年龄段间TAT、VAT、SAT、BMD的差异及TAT、VAT、SAT与BMD的相关性。结果50岁以上男性各年龄段TAT、VAT高于30~39岁男性(P均<0.01),而SAT低于30~39岁男性(P均<0.05)。50岁以上女性各年龄段TAT、VAT、SAT高于30~39岁女性(P均<0.001)。50岁以上男性及女性各年龄段间TAT、VAT、SAT比较,差异均无统计学意义(P均>0.05),40~49、50~59岁年龄段分别较上一年龄段VAT明显增多(P均<0.01),BMD随年龄增长逐渐减低(P均<0.001)。多元逐步回归分析显示,VAT是女性BMD的独立影响因素(β=-0.089,P=0.007),TAT、SAT不是BMD的独立影响因素(P均>0.05)。结论腹部脂肪和BMD随年龄发生变化,男性和女性均在40~59岁出现VAT明显增多。VAT可能是女性BMD的独立负性影响因素。     

Pharmacokinetic evaluation of guar gum-based colon-targeted drug delivery systems of tinidazole in healthy human volunteers

The aim of the present investigation was to determine the in vivo availability of guar gum-based colon-targeted tablets of tinidazole in comparison with immediate release tablets of tinidazole in human volunteers. Six healthy volunteers participated in the study, and a cross-over design was used. The plasma concentration of tinidazole was estimated by HPLC. The pharmacokinetic parameters were calculated from the plasma concentration of tinidazole versus time data. The immediate release tablets of tinidazole produced a peak plasma concentration (C_max of 3239 ± 428 ng/ml) at 1.04 ± 0.32 hr (T_max), whereas colon-targeted tablets produced peak plasma concentration (C_max of 2158 ± 78 ng/ml) at 14.9 ± 1.6 hr. The delayed T_max, decreased C_max, and K_a, and unaltered bioavailability and elimination half-life of tinidazole from guar gum-based colon-targeted tinidazole tablets, in comparison with the immediate tablets, indicated that the drug was not released in the stomach and small intestine but delivered to the colon. Slow absorption of the drug from the less absorptive colon might result in the availability of the drug for local action in the colon. The guar gum-based colon-targeted tablets of tinidazole may be useful in providing an effective and safe therapy of intestinal amoebiasis.     

颈部脊柱推拿对健康志愿者自主神经功能的影响

目的 脊柱推拿是传统医学的治疗方法之一。根据中医学脏腑经络相关理论,观察颈部脊柱推拿对自主神经系统功能的调节作用。方法 选择成年健康男性志愿者,通过对受试者颈部进行推拿操作,包括触压双侧颈椎横突（C2-5水平）、左右旋转和扳法,以心率和心率变异性的改变为指标,观察推拿前后自主神经系统紧张性的改变。结果 对30名正常成年男性志愿者的观察结果表明,推拿后心率显著降低（R-R间期延长）;时域分析中SDNN显著性增加,频域分析中总功率谱显著性增加。以上结果皆提示迷走性张力增高。结论 颈部脊柱推拿可调节自主神经系统张力,提示了针灸推拿方法治疗临床心血管疾病如心律失常的可能性。     

Participant Selection Biases in a Randomized Clinical Trial of Alcoholism Treatment Settings and Intensities

Eligible participants and decliners in a randomized study of inpatient, intense outpatient, and standard outpatient treatments for alcoholics were compared and contrasted on a series of demographic, social stability, psychological, legal, drug use, problem severity, and treatment history variables. Among 302 individuals meeting eligibility requirements, those agreeing to participate, compared with decliners, were more likely to be unemployed, be residentially less stable, have legal problems, use other drugs, have a more severe alcohol problem, have a recent treatment history, and were less likely to have problems with violence. Participants also were more likely to be male and non-white, although gender and racial effects were not significant when other variables were controlled for. The implications of these findings for generalizing the results of inpatient-outpatient studies are discussed, and the need for routine reporting of decliner characteristics in research reports is stressed.     

Estimation of individual uptake of trichloroethylene, 1,1,1-trichloroethane and tetrachloroethylene from biological parameters

Summary The results of single exposure studies with exposure to trichloroethylene, TRI, (Monster et al., 1976), to 1,1,1-trichloroethane, MC, (Monster et al., 1979b) and to tetrachloroethylene, PERC, (Monster et al., 1979c) were used to study the precision in estimating the individual uptake from measured biological parameters after exposure. With simple linear and multiple linear regression analysis the individual uptake of TRI, MC and PERC was estimated from the concentrations of solvents and metabolites in biological media (blood, urine, exhaled air) at 2 h and at 20 h after exposure. The best results are obtained by estimation from the concentrations in blood, particularly of the solvents themselves. Including results of simultaneously measured concentrations in exhaled air or urine did not improve the estimate.     

Controlled in vivo release of nicorandil from a carvone-based transdermal therapeutic system in human volunteers

The aim of our present study was to prepare and evaluate a carvone-based transdermal therapeutic system (TTS) of nicorandil to find its ability in providing the desired in vivo controlled release profile on dermal application to human volunteers. The effect of EVA 2825, and adhesive-coated EVA 2825, and adhesive-coated EVA 2825-rat skin composite on the in vitro permeation of nicorandil from a carvone-based HPMC gel drug reservoir was studied against a control (rat abdominal skin alone). The carvone-based drug reservoir system was sandwiched between adhesive-coated EVA 2825-release liner composite and a backing membrane. The resultant drug reservoir sandwich was heat-sealed to produce a circle-shaped TTS (20 cm²) that was subjected to in vivo evaluation on dermal application to human volunteers against oral administration of immediate-release tablets of nicorandil. The carvone-based TTS provided a steady-state plasma concentration of 20.5 ng/ml for ∼24 hr in human volunteers. We concluded that the carvone-based TTS of nicorandil provided the desired in vivo controlled-release profile of the drug for the predetermined period of time.     

大型活动志愿者应急应对方式及影响因素研究

目的研究大型活动志愿者对突发应急事件的应对方式和影响因素。方法采用应对方式问卷、社会支持评定量表和自我和谐量表对4所高校的416名上海世博会志愿者进行问卷调查。结果志愿者自我和谐与全国大学生常模相比具有显著性差异,自我与经验的不和谐(t=-4.87,P<0.001)及自我的刻板性(t=13.06,P<0.001)比常模下降,自我的灵活性(t=5.75,P<0.001)上升。有效问卷的416志愿者中,342名的应对行为为成熟型(82.2%),不同行为类型的人员达标情况存在差异,应对行为类型和得分达标数情况相关(χ2=129.7,P<0.001)。对作用效应而言,自我经验的不和谐、自我刻板性、危机意识和应变能力的缺乏等是影响应对方式的负性因素,社会支持、自我灵活性和志愿者经历等是正性因素。支持的利用度、自我经验的不和谐、活动前培训、危机意识和应变能力的影响较为普遍,其他则比较单一。结论志愿者应对突发事件的方式总体成熟稳定,但具有个体差异,并受多种因素影响,有必要针对志愿者人群开展干预训练,进一步提高其整体应对方式的成熟程度。