Haematological parameters of parvovirus B19 infection in 13 fetuses with hydrops foetalis

Thirteen cases of fetal parvovirus B19 infection with hydrops foetalis are reported. Viral DNA was identified by polymerase chain reaction (PCR) of amniotic fluid sampled between the 19th and the 29th week of gestation. Haematological examination revealed severe anaemia in all cases and thrombocytopenia in 11/13 cases, which was severe in two cases. Six fetuses died in utero; two after intrauterine transfusion. Complete recovery was observed in seven fetuses; five cases were treated by intrauterine transfusions, and in two cases spontaneous recovery occurred. Upon follow-up, no case of congenital anaemia was observed.     

Surfactant protein-A in bronchoalveolar lavage fluid from neonates with RDS on conventional and high-frequency oscillatory ventilation

Surfactant protein-A (SP-A) was measured in bronchoalveolar lavage (BAL) samples from ventilated neonates in order to study the concentration of SP-A with regard to: 1) high-frequency oscillatory ventilation (HFOV) vs. conventional mechanical ventilation (CMV); 2) the postnatal course and ontogeny of SP-A; and 3) the correlation with measurements of pulmonary function. Patients on HFOV had markedly lower BAL SP-A concentrations on days 1 and 2 compared to those on CMV, which may indicate influence of mode of ventilation on surfactant metabolism. The SP-A concentrations increased postnatally concurrent with resolution of acute respiratory distress syndrome. Finally, there were only weak correlations between BAL SP-A concentration and dynamic lung compliance and oxygen requirement.     

Analyzing the time and value of housestaff inpatient work

OBJECTIVE: To determine time allocation and the perceived value to education and patient care of the weekday activities of internal medicine housestaff on inpatient rotations and to compare the work activities of interns and residents. DESIGN: An observational study. We classified activities along five dimensions (association, location, activity, time, and value), developed a computer-assisted self-interview survey, and demonstrated its face and content validity, internal consistency, and interrater reliability. Subjects were assigned survey computers for 5 consecutive weekdays over a 24-week period, into which they entered data when prompted several times a day. SETTING: The medical service of a university-affiliated Veterans Administration Medical Center. PARTICIPANTS: Sixty housestaff (36 interns, 24 residents) rotating on the inpatient wards. MEASUREMENTS AND MAIN RESULTS: We analyzed activities according to content (direct patient care, indirect patient care, education), association, and location. Likert-scale ratings of perceived value to education and patient care were also obtained. Housestaff provided complete responses to 3,812 (95%) of 3,992 prompts by a median of 11 seconds; 93% of responses were logically consistent across the measured dimensions. Housestaff spent more time in indirect patient care (56%) than in direct patient care (14%) or educational activities (45%). Formal educational activities had the highest educational value (66 on 0–100 scale), and direct care had the highest value to patient care (81). Over 30% of time was spent in administrative activities, which had low educational value (40). Compared with residents, interns allocated significantly less time to educational activities (38% vs 57%) and more time to lower-value activities such as documentation (19% vs 12%). CONCLUSIONS: Improved data collection methods demonstrate that housestaff in our program, particularly interns, spend much of their workday in activities that are low in educational and patient care value. Selective elimination or delegation of such activities would preserve higher-value experiences during reductions in overall inpatient training time. Planners can use automated random sampling to guide the rational redesign of housestaff work. Support for this work was provided by the Western Region of the Veterans Administration (Ambulatory Care and Education Initiative, 94–04), the Veterans Administration Center for the Study of Provider Behavior, and the RAND Graduate School. Dr. Bozzette is a Senior Research Associate of the HSR&D Service, Department of Veterans Affairs.     

湖北省血吸虫病不同亚型流行区抽样调查病情对比分析

目的 掌握全省血吸虫病不同亚型流行区病情动态，评价防治效果，为制定防治规划提供科学依据。方法 以行政村为单位．采用分层整群随机抽样法，于1989、1995、2001三个年度分别对人、畜进行血吸虫粪检查病，用EXCELL建立数据库，SAS统计分析。结果 3次抽样调查中，不同亚型流行区人群和耕牛感染率总体呈下降趋势，但病人和人群感染度(EPG)均呈上升趋势。洲滩、垸内地区居民感染率和EPG男性高于女性，但丘陵地区女性高于男性；各亚型流行区30-岁以上的年龄组人群感染率和EPG较高。2001年洲滩、丘陵地区人群感染率和EPG最高的职业是农民，垸内地区是渔民。结论 3次抽样调查结果显示，虽然全省人群和耕牛感染率总体呈下降趋势，但不同亚型流行区的病人和人群EPG均呈上升趋势。因此，防治工作需针对不同亚型地区的流行特点，因地制宜，加大力度。巩固血防成果。     

批质量保证二次抽样法在抗疟药治疗恶性疟疗效监测中的适用性研究

目的　探索批质量保证二次抽样法 (DLQAS)在抗疟药对恶性疟疗效监测中应用的可能性。　方法　在现场按WHO推荐的 2 8d体内法氯喹疗效评估方案收集病例 ,给予氯喹治疗 ,判定治疗失败与否 ,比较传统的流行病学方法与DLQAS法对疗效判定的结果 ,评估和比较对样本量的需求。　结果　传统方法调查到治疗失败率为 40 .7% ,DLQAS法第一阶段和第二阶段调查到治疗失败率均大于WHO推荐换用药物治疗失败率上限 2 5 % ;DLQAS法的样本量比传统的流行病学横断面抽样方法少。　结论　DLQAS的现场调查治疗失败判定结果同传统流行病学方法 ,且样本量小、快速 ,适用于对抗疟药治疗恶性疟疗效监测的现场评估。     

Analysis of temporal requirements for myocardial tissue velocity imaging.

AIMS: Movements of myocardial walls include components of high velocity and short duration calling for a high sampling rate in the acquisition of tissue velocity imaging data. This study aims at establishing the optimal sampling requirements for tissue velocity imaging measurements. METHODS AND RESULTS: In 16 healthy individuals, tissue velocity imaging data were acquired at a frame rate of 141-203 frames/s for a subsequent off-line analysis using software enabling a reduction of the sampling rate to 50%, 25% and 12.5% of the initial frame rate. Different components of the myocardial velocity profile were measured at each of these frame rates. The deviation of the results from the initial values increased markedly at decreasing frame rates, producing an underestimation of peak systolic and diastolic velocities, most other measured parameters being overestimated. A cut-off point for an acceptable < or =10% deviation of the results corresponded to at least 70 frames/s for peak systolic and early diastolic velocity, and to at least 100 frames/s for other systolic and diastolic parameters. CONCLUSION: A high sampling rate is essential for a proper rendering of tissue velocity imaging signals, too low frame rates resulting in inferior accuracy of the results. This should be kept in mind while viewing reported tissue velocity imaging data.     

Constrained spherical deconvolution of nonspherically sampled diffusion MRI data

Constrained spherical deconvolution (CSD) of diffusion‐weighted MRI (DW‐MRI) is a popular analysis method that extracts the full white matter (WM) fiber orientation density function (fODF) in the living human brain, noninvasively. It assumes that the DW‐MRI signal on the sphere can be represented as the spherical convolution of a single‐fiber response function (RF) and the fODF, and recovers the fODF through the inverse operation. CSD approaches typically require that the DW‐MRI data is sampled shell‐wise, and estimate the RF in a purely spherical manner using spherical basis functions, such as spherical harmonics (SH), disregarding any radial dependencies. This precludes analysis of data acquired with nonspherical sampling schemes, for example, Cartesian sampling. Additionally, nonspherical sampling can also arise due to technical issues, for example, gradient nonlinearities, resulting in a spatially dependent bias of the apparent tissue densities and connectivity information. Here, we adopt a compact model for the RFs that also describes their radial dependency. We demonstrate that the proposed model can accurately predict the tissue response for a wide range of b‐values. On shell‐wise data, our approach provides fODFs and tissue densities indistinguishable from those estimated using SH. On Cartesian data, fODF estimates and apparent tissue densities are on par with those obtained from shell‐wise data, significantly broadening the range of data sets that can be analyzed using CSD. In addition, gradient nonlinearities can be accounted for using the proposed model, resulting in much more accurate apparent tissue densities and connectivity metrics.     

Development of an automated blood sampling system for use in humans

Many hormones are released in a pulsatile or burst-like pattern resulting in fluctuating blood levels that can undergo rapid modulation by physiological and pathological signals. To accurately measure these changes in hormone concentration requires frequent blood sampling, often over extended periods as the overall rhythmicity may vary over 24 hours. The aim of this study was to develop a computerized, automated blood sampling system which allows repeated stress-free blood sample collection from humans over an extended period under basal or test conditions. The system incorporates a peristaltic pump, fraction collector and standard infusion pump together with a custom built electronic control unit linked to a personal computer. Disposable tubing prevents cross-contamination between study participants. The computer programme is modifiable to adjust for the number of specimen tubes and volume of blood collected per sampling cycle. Patency of the collecting line is maintained with 0.9% saline, without the need for heparinization. To validate the system, 10-minute samples for cortisol were collected over 24 hours from five healthy volunteers, of whom two had additional concomitant ACTH sampling. Deconvolution analysis revealed an expected number of hormone secretory episodes and a non-pathological degree of orderliness within the data. There was high concordance between ACTH and cortisol secretory events. The ability of the system to allow multiple measurements and of the software program to link with other physiological monitoring equipment provides a powerful tool to study physiologic/pathophysiologic change in relation to blood hormone and other biomarker levels.     

碘治疗工作场所空气中131I的监测结果与分析

目的 了解碘治疗工作场所空气中¹³¹I气溶胶的活度浓度,估算核医学科医务人员吸入¹³¹I所致内照射剂量。方法 使用CF-1001BRL型便携式大容量空气采样器,采用碘盒收集山东省6家医院核医学科碘治疗工作场所空气中的¹³¹I气溶胶,利用HPGe-γ能谱仪对样品进行测量,得到6家医院碘治疗工作场所中¹³¹I的活度浓度值,并估算医务人员的内照射剂量。结果 6家医院碘治疗工作场所空气中¹³¹I的活度浓度范围为3.64~2.94×10³Bq/m³,控制区（病房、患者通道、分装间、远程操作给药室）¹³¹I的浓度水平明显高于监督区,监督区¹³¹I的浓度最高的是医护通道,为2.62×10²Bq/m³。核医学科医务人员两种职业待积有效剂量估算值为0.07~5.68 mSv,均未超过国家规定限值。结论 医院核医学科碘治疗工作场所仍存在不可忽视的¹³¹I气溶胶污染现象,应面向全国各地区核医学科开展内照射监测,探索更加合理的防护标准和方法。