Posttraumatic thrombosis of the middle cerebral artery

Posttraumatic cerebral infarction resulting from carotid or cerebral artery occlusion is rare. Traumatic dissection of the carotid artery is the most frequent cause of infarction, whereas posttraumatic thrombosis of the cerebral artery is very rare. The authors describe a case of posttraumatic thrombosis of the left middle cerebral artery. Early in the morning, a 16-year-old boy was found unconscious in the parking lot of a supermarket. He had received fist blows and kicks to the head, face, body, back, and hip during the night. Computed tomography 10 hours after the violence revealed a gross cerebral infarction in the area of the left middle cerebral artery. He died 9 days after the violence. The autopsy revealed a thrombosis in the left middle cerebral artery. Microscopically, granulation tissue in the intima and a rupture of the internal elastic lamina were observed near the beginning of the artery. It was concluded that the blows to the head and face caused a partial rupture in the arterial wall, leading to thrombosis and cerebral infarction.     

Transfer of biological traces in cases of hanging and ligature strangulation

In hanging and ligature strangulation, the noose mostly causes a mark or groove which is formed partly by compression of the skin and partly by abrasion with loss of the upper epidermal layers. The horny scales abraded from the neck may be transferred to the strangulation device or to the interposed textiles where they are sometimes visible at stereomicroscopic examination or even to the naked eye as silver-grey particles. The morphologic features of the epidermal transfer due to hanging and ligature strangulation is demonstrated by 14 case examples. The biological traces may be sufficient for comparative DNA typing by means of PCR-based methods. In 9 out of the 14 cases, genomic DNA typing was successful. Analysis of mtDNA succeeded in another two cases, although genomic DNA could not be detected. Beside the accumulation of solid epidermic particles the paper describes deposition of serous and fatty tissue fluid at the ligature (mainly adjacent to skin ridges).     

Spectra interference between diquat and paraquat by second derivative spectrophotometry

A rapid and accurate method, combining solid-phase extraction and second-order derivative spectrophotomety approaches, is developed for the simultaneous determination of diquat (DQ) and paraquat (PQ) in blood, tissue and urine samples. Supernatant resulting from the precipitation of protein (with trichloroacetic acid) in plasma and tissue or Amberlite IRA-401 resin treated urine are passed through a mini-column packed with Wakogel gel (Silica gel). Analytes are then eluted with a non-organic solvent, 0.2mol/l HCl solution containing 2mol/l NH(4)Cl. UV spectrum of the eluent in 220-350nm range provides effective screen to detect the presence of DQ and/or PQ. In the presence of DQ or PQ alone, the analyte present is quantitated by conventional zero- or second-order derivative spectrophotometry. The calibration curve in the 0.1-5.0mg/l range for either analyte obeys Beer's law. When both DQ and PQ are present, their concentrations are determined by the peak amplitudes of their respective second-derivative spectra after the addition of alkaline dithionite reagent. Interference is negligible when the DQ/PQ concentration ratio is within the 5.0-0.2 range.Using a 2-ml of sample size, the detection limits for DQ and PQ in plasma are 0.02 and 0.005mg/l. The corresponding detection limits for urine samples (10ml sample size) are 0.004 and 0.001mg/l. Recoveries of DQ and PQ in triplicate plasma and urine samples spiked with 0.5mg/l of analytes are 93 and 85%. The precision of the proposed method resulting from triplicate study of spiked urine samples varies from 3.2 to 4.6% at 0.5mg/l of DQ and PQ, respectively.     

Detection and assay of cis- and trans-isomers of 4-methylaminorex in urine, plasma and tissue samples

The 4-methylaminorex (4-MAX) is an amphetamine-related psychostimulant drug that has appeared on the clandestine market with a street name of "U4Euh". This compound exists as four stereoisomers, trans-4R,5R, trans-4S,5S, cis-4R,5S and cis-4S,5R, of which the cis forms have been classified as Schedule I substances in the US. The increasing variety of designer drugs has highlighted the importance of detection, identification, and quantitative measurement of these drugs, including 4-MAX, in biological samples. In the present study, the isomers of 4-MAX were detected in urine of rats treated with the drugs by some but not all of the on-site immunoassays tested, mainly as amphetamine or methamphetamine. To facilitate identification of 4-MAX by laboratories specialized in drug analysis, the electron-ionization mass spectrum and TLC data for underivatized 4-MAX using a routine laboratory drug-screening procedure is provided. In addition, a GC/MS method is described for the quantitative determination of cis- and trans-4-MAX as tert-butyldimethylsilyl-derivatives in plasma, urine and tissue.     

Entrepreneurship, Secrecy, and Productivity: A Comparison of Clinical and Non-Clinical Life Sciences Faculty

This paper addresses research in the life sciences, responsible for significant national expenditures for scientific investigations funded by both the federal government and industry. Our investigation examines faculty members' involvement with industry in entrepreneurial ways that is, involved in translating their research into potentially marketable knowledge or products. First, this study examines whether there are differences in entrepreneurial behaviour between clinical and non-clinical faculty in the life sciences with industry relationships, and, second, to discover any linkage between entrepreneurship and secrecy or productivity in different ways for clinical and non-clinical faculty. The study is based on survey responses of a national sample of 4,000 clinical and non-clinical life sciences faculty in 49 U.S. research universities. The results show non-clinical faculty as more involved at the back end. The more entrepreneurial end of commercialization while clinical faculty are involved at the back end. The more entrepreneurial faculty (non-clinical) are more likely to be secretive about their research. Clinical faculty are less likely to have been denied access to research results or products. Entrepreneurial faculty are not less productive in their faculty roles. This investigation is preliminary in that it addresses one large area of academic research but excludes fields with longer historical relationships with industry.     

大鼠脑挫伤后FN表达与损伤时程关系的研究

为寻找推断脑损伤经历时间的可靠指标,采用自制自由落体撞击法致大鼠右顶叶局灶性脑挫伤模型,于不同时间段处死大鼠后,进行纤维连接蛋白的免疫组织化学及原位杂交法研究,结果发现纤维连接蛋白及其 mRNA表达水平与伤后经历时间有一定相关性,并能较好地鉴别死前脑挫伤和死后脑挫伤,可作为推断脑挫伤经历时间的参考指标之一。