Age calculation using X-ray microfocus computed tomographical scanning of teeth: a pilot study

To correlate dental age with an individual's chronological age based on the calculated volume ratio of pulp versus tooth volume measured, an X-ray microfocus computed tomography unit (microCT) with 25 microm spatial resolution was used to non-destructively scan 43 extracted single root teeth of 25 individuals with well-known chronological age. Custom-made analysis software was used by two examiners to obtain numerical values for pulpal and tooth volume. The ratio of both was calculated and statistically processed. No significant intra- or inter-examiner differences were found. In fact, a very strong concordance correlation coefficient was found. Linear regression analysis showed a coefficient of determination (r) of 0.31 which suggests that there is a rather weak correlation between the volume ratio of pulp versus tooth and biological age. Although rather time consuming, this technique shows promising results for dental age estimation in a non-destructive manner using X-ray microfocus computed tomography.     

运用二重PCR和DNA芯片技术检测ABO基因型

目的以玻片为载体,用寡核苷酸探针杂交技术检测ABO基因型。方法根据ABO基因座外显子6和外显子7的3个SNP点的序列分布特征设计4条寡核苷酸探针,制成分型芯片。将待测样品DNA用末端标记了Cy5的引物进行二重PCR扩增,产物与芯片上的探针进行杂交,根据杂交产生的荧光信号确定样品的ABO基因型。结果利用ABO芯片,可对血斑、毛发等微量检材进行ABO基因型检测。对115名汉族无关个体的调查表明,ABO基因型的分布符合Hardy-Weinberg平衡,等位基因杂合度观察值和期望值分别为0.591、0.616,多态信息含量为0.544,二联体和三联体非父排除率分别为0.188、0.334,个体识别能力为0.777。结论通过DNA芯片检测ABO基因型的技术适用于法医学样本,可满足高通量的检测需求。     

致心律失常性右心室心肌病

致心律失常性右心室心肌病是以右心室心肌被脂肪或纤维脂肪组织取代为特征的一种原因尚不明确的心肌病。目前已公认是年轻人猝死的重要原因之一。ARVC最显著的病理学特征是弥散性或节段性的右心室游离壁心肌的缺失及纤维脂肪组织的替代,从组织形态学可将ARVC分为两型:(1)单纯脂肪型;(2)纤维脂肪型。与纤维脂肪组织取代右心室心肌有关的发病机制:(1)细胞凋亡或程序性细胞死亡理论;(2)炎症理论;(3)心肌发育不良理论;(4)肌细胞转分化理论。     

毒鼠强中毒现状及研究进展

毒鼠强是急性中枢神经兴奋性杀鼠剂,具有中毒量小、毒作用快、后果严重的特点。由于毒鼠强属违禁药品,对毒鼠强的研究目前多局限于毒鼠强中毒的临床救治,而缺乏对毒鼠强中毒的系统基础研究。笔者结合国内外有关文献,将毒鼠强的中毒机制、病理变化及有关研究前景综述。     

溺死大鼠肺组织水通道蛋白1的表达

目的检测生前溺死与死后抛尸的肺组织水通道蛋白的表达。方法取2种死亡方式条件下大鼠肺组织,用免疫组织化学方法检测肺组织中水通道蛋白1表达的分布特征。结果两种死亡条件下肺泡间质和支气管周围的毛细血管内皮及肺泡上皮均有AQP1的阳性表达,但积分光密度值(intergratedopticaldensity,IOD)值有显著性差别。结论AQP1在大鼠两种溺死条件下表达差别有统计学意义。     

Independent medical review: expanding legal remedies to achieve managed care accountability

Author Leatrice Berman-Sandler reports on independent medical review (IMR), a state-based statutory remedy used to resolve disputes over coverage between patients and their health plans. Ms. Berman-Sandler explores the connection between ERISA preemption and IMR, and opines that in light of recent Supreme Court decisions, the stage has been set for expansion of IMR. Accordingly, Ms. Berman-Sandler concludes that there are strong legal and policy reasons for state legislatures to broaden the application of IMR and for the Court to continue to narrow ERISA preemption in order to increase accountability in the managed care arena.     

A Spanish population study of 17 Y-chromosome STR loci

Haplotype, allele frequencies and population data of 17 Y-chromosome STR loci DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460 (GATA A7.1), DYS461 (GATA A7.2), GATA A10, GATA C4 and GATA H4 were determined from a sample of 148 unrelated male individuals from Spain. A total of 144 haplotypes were identified by the 17 Y-STR markers, of which 141 were unique, two were found in two individuals and one was found in three individuals. The haplotype diversity (99.95%) and discrimination capacity (97.30%) were calculated. Comparisons were made with previously published haplotype data on other Iberian population samples and no significant differences were found.     

A rapid screening procedure for drugs and poisons in gastric contents by direct injection-HPLC analysis

A high performance liquid chromatographic method for toxicological drug screening of gastric content has been developed. The samples were diluted (1:3-1:30) in 0.01 N hydrochloric acid and injected into a reverse phase column for separation by gradient elution. Mobile phase consisted of solvent A (acetonitrile/water 90:10, 0.01 M sodium dodecylsulphate, 0.5% v/v glacial acetic acid) and solvent B (water/acetonitrile 90:10, 0.01 M sodium dodecylsulphate, 0.5% v/v glacial acetic acid); the gradient was programmed from 20 to 80% A in 30 min. The flow was kept constant at 1.5 ml/min. Two home-made internal standards, butyrylsalicylic acid and diacetyltubocurarine with retention times of 5.6 and 21.4 min, respectively, were used. Drugs are identified by matching their relative retention times and UV spectra (200-400 nm) with those contained in a home made library of more than 340 reference compounds (9 analgesics, 22 antidepressants, 30 antihistamines, 14 antihypertensives, 21 antirheumatics, 15 beta-blockers, 9 bronchodilators, 10 Ca antagonists, 14 diuretics, 26 neuroleptics, 25 tranquilizers, and other significant xenobiotic compounds). The fluorometric (FLD) emission spectrum (280-700 nm; excitation wavelength, 230 nm) was used as a further identification. At 50mg/l analyte concentrations, the injection of gastric content after dilution (1:3) produced S/N ratios in the range 8-140. The method is simple, rapid, rather inexpensive and proved to be a useful means of investigation if used in combination with GC-MS screening in blood. On the other hand, the system suffers from a relatively limited sensitivity for compounds with a low UV absorption and from interferences due to the presence in the matrix of some highly UV- and FL-responsive compounds (e.g. tryptophan).