A first insight on the population structure of Mycobacterium tuberculosis complex as studied by spoligotyping and MIRU-VNTRs in Bogotá, Colombia

With an incidence of 25.6/100,000 in 2008, tuberculosis (TB) remains an important public health problem in Colombia. In this study, a total of 152 Mycobacterium tuberculosis complex strains isolated in Bogotá, Colombia between years 1995 and 2007 were genotyped by spoligotyping and 12-loci MIRU-VNTRs. The various spoligotyping-based genotypic lineages in our sample were: Latin American & Mediterranean (LAM) n = 75, 49.34%; Haarlem, n = 38, 25.0%; ill-defined T group, n = 21, 13.82%; S family, n = 5, 3.29%; X clade, n = 2, 1.32%; Beijing, n = 1, 0.65%, while strains with unknown signatures (n = 10) represented 6.58% of isolates. Using spoligotyping as a first molecular marker and MIRU-VNTRs as second marker, we obtained 102 single patterns and 14 clustered patterns (n = 52 strains from 49 patients, 2–8 strains per cluster). The MIRU-VNTRs patterns corresponded to 50 MITs for 109 strains and 43 orphan patterns. The most frequent patterns were MIT190 (n = 12), MIT45 (n = 10), and MIT25 (n = 9). The Hunter & Gaston discriminatory index (HGDI) of both methodologies used together showed a value of 0.992. In our setting, the HGDI of five loci subset (MIRU10, 16, 23, 26 and 40) contributed most to the discriminatory power of 12-loci format used (HGDI = 0.977). The lineage distribution of M. tuberculosis showed that more than 3/4 of strains in Bogotá are commonly found in Latin America, Caribbean, and Europe. This observation might reflect the shared post-Columbus history of Colombia and its Latin-American neighbors as well as strains brought in by 20th century immigrants from Europe. We also demonstrate the usefulness of MIRU-VNTR to detect suspected links among patients and polyclonal infections.     

Confocal Raman micro-spectroscopy for rapid and label-free detection of maleic acid-induced variations in human sperm

Confocal Raman microspectroscopy is a valuable analytical tool in biological and medical research, allowing the detection of sample variations without external labels or extensive preparation. To determine whether this method can assess the effect of maleic acid on sperm, we prepared human sperm samples incubated in different concentrations of maleic acid, after which Raman spectra from the various regions of sperm cells were recorded. Following the maleic acid treatment, Raman spectra indicated significant changes. Combined with other means, we found that the structures and chemical compositions of sperm membranes were damaged, and even the sperm DNA was damaged by the incorporation of maleic acid. Thus, this technique can be used for detection and identification of maleic acid-induced changes in human sperm at a molecular level. Although this particular application of Raman microspectroscopy still requires further validation, it has potentially promise as a diagnostic tool for reproductive medicine.OCIS codes: (300.6450) Spectroscopy, Raman; (170.0170) Medical optics and biotechnology; (170.5660) Raman spectroscopy; (170.1530) Cell analysis     

汉族与壮族青年人格结构的比较

目的:根据人口比例、地理位置、生产方式、语言文字状况等方面来选择了汉族与壮族民族作为研究的对象,比较汉族与壮族青年的人格结构。方法:于2005-07/2005-09在广州、湛江、东莞、天津、西安、长沙、沈阳、南宁等地进行样本采集。在汉族被试中发放问卷共1370份,在壮族被试中发放问卷共440份。具体操作是:在当地学校开家长会期间,在不同年级中采用整群随机抽样的方法选取某一班级的家长进行团体施测。汉族被试者平均年龄(33.1±0.3)岁,壮族被试者平均年龄(32.2±0.8)岁。选用的量表是中国人人格形容词评定量表(简式)。该量表包括了“外向活跃”、“严谨自制”、“温顺随和”、“热情豪爽”、“淡泊诚信”、“精明干练”、“善良友好”7个分测验,采用6级评分,要求被试对每一个项目做1～6分(即“完全不符合自己的情况”到“完全符合自己的情况”)的评定。分析两个民族与“‘大七’人格结构模型”的拟合度、两个民族人格结构的均值。结果:在汉族被试者中发放问卷共1370份,回收问卷1368份,问卷回收率99.85%。在壮族被试中发放问卷共440份,回收问卷431份,问卷回收率98.0%。根据回答量表的有效情况,筛选汉族有效被试共985名,壮族有效被试共307名。①汉族的人格结构与“大七人格结构模型”拟合良好,而壮族则拟合不良,拟合优度指数分别为0.84,0.62。②壮族在“外向活跃”、“温顺随和”、“热情豪爽”“善良友好”4个人格结构因子上的得分均显著高于汉族(44.70±5.58,43.26±6.78;31.62±4.62,30.39±4.96;31.72±3.98,30.80±4.63;18.92±4.19,18.36±4.04;F=7.91,10.43,6.84,3.16,P<0.01,0.05)。两族在“严谨自制”、“淡泊诚信”、“精明干练”这几个方面没有差异。结论:汉族与壮族因各自生态环境的相似性与差异性而导致了文化形态的异与同,从而导致了两个民族所形成的行为方式的共性与个性,而在本调查中则具体体现为两个民族人格结构的异同。     

聚乳酸载药纳米球的制备工艺及性能研究

运用均匀设计实验,以灰黄霉素为囊心物质用油包水溶剂挥发法制备灰黄霉素/聚乳酸纳米球,并且分析比较了载药微米球和纳米球的释药性能。结果表明所获得的纳米球球形较好且较为分散,粒径分布较为均一,粒径在114 nm左右。经线性回归和三次重复试验得出综合评分S为95.59,误差为3.66%,载药量为13.55%。载药微米球的释药速率较慢,而纳米球在性能上有一个“突跃”,能起到“增溶”药物的作用。     

Microwave-induced thermoacoustic scanning CT for high-contrast and noninvasive breast cancer imaging

A fast thermoacoustic computed tomography system with a multielement linear transducer array was developed to image biological tissues with circular scanning. The spatial resolution of the imaging system and the spectra of the thermoacoustic signals were analyzed. A modified integration backprojection algorithm using velocity potential was employed to recover the direct energy deposition distribution, signal processing methods, and reconstruction algorithms were validated by imaging a phantom. The differences of the microwave-frequency dielectric properties between malignant and normal adipose-dominated tissues in the breast are considerable, and the absorption contrast can reach as large as 6:1 at 1.2 GHz. An experiment of human breast tissue with a tumor was performed with this system; the thermoacoustic images reconstructed by a limited-field-filtered backprojection algorithm and a modified integration backprojection algorithm were also compared with a mammogram. Our results show that the system can provide a rapid and noninvasive approach for high-contrast breast cancer imaging.