Fast Three Dimensional Magnetic Resonance Imaging

To reduce the scan time in three-dimensional (3D) imaging, the authors consider alternative trajectories for traversing k-space. They differ from traditional 3D trajectories, such as 3DFT, in that they employ time-varying gradients allowing longer readouts and in turn a reduced scan time. Some of these trajectories reduce by an order of magnitude the number of excitations compared with 3DFT and provide flexibility for trading off signal-to-noise ratio for scan time. Other concerns are the minimum echo time and flow/motion properties. As examples, the authors show two applications: A 3D data set of the head (field of view of 30 x 30 x 7.5 cm and resolution of 1.5 x 1.5 x 1.5 mm) acquired in 56 s using a stack of spirals in 3D k-space; and a 3D movie of the heart (20 x 20 x 20 cm field of view, 2 x 2 x 2 mm resolution, and 16 time frames per cardiac cycle) acquired in 11 min using a cones trajectory.     

高血糖对非胰岛素依赖型糖尿病患者红细胞（Ca~（2＋）－Mg~（2＋））－ATP酶的影响

为了解高血糖对非胰岛素依赖型糖尿病（ＮＩＤＤＭ）患者红细胞膜（Ｃａ２＋－Ｍｇ２＋）－Ａｒｐ酶的影响，采用改良的Ｈａｎａｈａｎ和Ｌｕｔｈｒａ法测定了红细胞膜（Ｃａ２＋－Ｍｇ２＋）－ＡＴＰ酶活性。结果表明，ＮＩＤＤＭ患者红细胞膜（Ｃａ２＋－Ｍｇ２＋）－ＡＴＰ酶活性降低，且与空腹血糖、糖化血红蛋白、果糖胺及红细胞变形指数呈负相关，后者与红细胞内Ｃａ２＋浓度呈正相关。说明（Ｃａ２＋－Ｍｇ２＋）－ＡＴＰ酶活性下降时，红细胞变形能力降低，可能与患者红细胞膜蛋白的过度糖化及细胞内Ｃａ２＋浓度的增高有关。     

Untersuchung zur Morbidität der indigenen Volksgruppen der Chiquitanos im südlichen Amazonasgebiet

The Chiquitano-tribe lives in the southern Amazonas region in Bolivia, remote from larger towns. A study (n=1514) on morbidity over an one year period (April 1995 till March 1996) and its relation to general and social medicine is given. Most frequently, childreh under 15 years and women in parity age (15–45 years) sought consultation (34,1 %, 42,7 %). Gastrointestinal, respiratoral and gynecological-obstetric diseases were predominant (22,4 %, 16,2 % and 15,7 %). In the dry season, common colds and respiratoral infections represented the major health problem. In the rainy season, infectious diarrhea diseases caused by polluted water as a consequence of extended floods were most frequent. Typical tropical diseases (malaria, Dengue fever, Chagas’ disease, leprosy a.o.) and socially caused diseases (AIDS, dependencies on drugs and alcohol, consequencies of crime) were rarely seen. With respect to severity, 55,8 % of the patients showed mild disorders. More serious diseases were observed in 39, 8 %. 4,6 % of the patients were diagnosed severly ill and needed hospitalization. Epidemiological data on general and social medicine of minorities in developing countries and their actual degree of medical care are important in a shrinking world. The data are useful to estimate medical needs and plan improvements to the health care system especially in rural areas.     

响洪甸放射性废物坑放射卫生学调查及评价

本文调查了一个铀水冶厂放射性废物坑的污染情况,发现该坑周围农田及坑附近淠史杭大灌渠水、泥等均受到不同程度污染。这表明,即使处理小型铀水冶厂的放射性废物,在选址、掩埋等各个环节也都应严格做到科学、合理,并且还要做好掩埋后的管理工作。     

Rapp-Hodgkin Syndrome with Pili Canaliculi

Abstract: A 20-year-old woman and her 12-year-old brother had hypohidrotic ectodermal dysplasia, cleft lip and palate, midfacial hypoplasia with narrow nose from the nasal bridge to the tip, narrow dysplastic nails, and conical teeth and hypodontia, and hypospadias and hypoplastic uvula in the boy. The woman had major underdevelopment of intellectual capacity. The most important hair anomalies in both siblings were sparse eyebrows, pili torti, and pili canaliculi. Some of the pili canaliculi had two canals (pili bicanaliculi), and the cross section for scanning electron microscopy had a quadrangular aspect. This is the seventh family reported with Rapp-Hodgkin ectodermal dysplasia.     

Adenosine 5′-triphosphate,uridine 5′-triphosphate,bradykinin, and lysophosphatidic acid induce different patterns of calcium responses by human articular chondrocytes

Small calcium-mobilizing inflammatory mediators have been implicated in joint pathology. Here we demonstrate that bradykinin, adenosine 5′-triphosphate, uridine 5′-triphosphate, and lysophosphatidic acid raise the intracellular calcium concentration ([Ca²⁺]_i) in human articular chondrocytes. Heterologous cross-desensitization experiments showed that the uridine 5′-triphosphate response was abolished by prior treatment with adenosine 5′-triphosphate and conversely, that the adenosine 5′-triphosphate response was abolished by prior treatment with uridine 5′-triphosphate: this indicated competition for the same receptor site, whereas bradykinin and lysophosphatidic acid did not compete with other ligands. Pretreatment with thapsigargin abolished ligand-mediated Ca²⁺ responses but not vice versa: this confirmed that Ca²⁺ release occurred from intracellular stores. Single-cell analysis of Fura-2 acetoxymethyl ester loaded chondrocytes showed mediator-dependent patterns of oscillatory Ca²⁺ changes in a subset of cells when challenged with submaximal concentrations of bradykinin, adenosine 5′-triphosphate, or uridine 5′-triphosphate in the presence of extracellular Ca²⁺. However, no oscillatory responses were seen after a challenge with lysophosphatidic acid. Therefore, although a number of different Ca²⁺-mobilizing ligands activate chondrocytes, the differences that occur in the temporal patterning of Ca²⁺ responses may result in unique mediator-dependent changes in cellular activity.     

11β⁃羟化类固醇脱氢酶敲除对高脂饮食喂养小鼠认知功能的影响

目的：探究11β-羟化类固醇脱氢酶1（11β-hydroxysteroid dehydrogenase,11β-HSD1）基因敲除对小鼠整体代谢和认知功能的影响。方法：将C57BL/6J为遗传背景的野生对照组及11β-HSD1基因敲除组各15只小鼠高脂喂养20周,代谢笼评估能量代谢,行为学评估观察小鼠认知功能,电镜评估海马体的线粒体结构,免疫荧光及PCR确定其认知功能、线粒体功能相关基因及炎症基因的变化。结果：11β-HSD1基因敲除能够提高高脂喂养小鼠学习和记忆能力,改善握力,改善海马体的微结构、线粒体含量变多,认知相关基因、线粒体呼吸功能相关基因上调,炎症相关基因改变。结论：11β-HSD1敲除后高脂饮食喂养小鼠认知功能显著改善,握力显著提高,可能是治疗认知功能障碍的有效靶点。     

Quality assurance in IMRT: importance of the transmission through the jaws for an accurate calculation of absolute doses and relative distributions

The goal of IMRT is to achieve an isodose distribution conformed to the tumor while avoiding the organs at risk. For these tasks several gantry angles are selected, each one containing a series of different leaf configurations for the multileaf collimator (MLC) (segments). Verifying the relative distributions as well as the absolute doses is an important step for quality assurance issues. We have observed that an accurate modeling of the transmission of the primary x-ray fluence through the jaws and MLC as well as the head scatter is crucial for a precise calculation of relative doses and monitor units. Also, an inaccurate calculation of the output factor for small size segments can lead to important differences in the absolute dose for points under these segments. Incorrect models could lead to systematic errors of around 5% to 10% in the calculated monitor units and a shift in the isodose curves.     

Body composition estimates using different measurement techniques in a sample of highland subsistence farmers in Guatemala

This study aims at assessing the accuracy of estimates of body composition provided by bioimpedance (BIA) equations developed for U.S. populations when applied to a sample of Guatemalan farmers. If these equations were shown to have low validity, the second objective was to develop more accurate estimates of fat-free mass (FFM). One hundred males and females 19 to 45 years of age were randomly selected from four rural communities in the Western Highlands of Guatemala. Bioimpedance equations explained 59 and 33% of the variation in FFM, with a RMSE of 2.7 and 2.8 kg in males and females, respectively. Body fat (BF) predictions had a lower R². Using the “all possible regressions” procedure, the best subset for prediction of FFM used anthropometric and BIA variables as predictors. The best model for men and women included only anthropometric variables: 75% of the variance in FFM for men and 70% of the variance in women was explained by this model. The RMSE was 2.1 and 1.9 kg for both groups, respectively. It is concluded that FFM can be estimated from anthropometric dimensions with a high degree of accuracy and use of BIA does not provide more valid estimates.