Pesticide poisoning initially suspected as a natural death

A pesticide poisoning victim suspected initially as having died a natural death was autopsied. The victim was a 47-year-old male. Macroscopically, signs of acute death and, in particular, general erosion in the mucosa of the airways and esophagus were observed. In the gastric contents, which had a pungent smell and a greenish-brown color, 5.00 g/L of propanil, 1.27 g/L of carbaryl, 0.38 g/L of ethylbenzene, and 0.32 g/L of xylene were detected. In the blood (serum), 21.6 mg/L of propanil, 8.1 mg/L of carbaryl, 1.7 mg/L of ethylbenzene, and 4.0 mg/L of xylene were identified. Postmortem methemoglobinemia (45%) was recognized. The cause of death was considered to have been pesticide poisoning; propanil was probably most responsible for his death. The police considered the case to be "death with illness as the suspected cause." By performing an autopsy, however, we were able to clarify that the cause of death was pesticide poisoning.     

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.     

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.     

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。