上肢运动诱发电位研究

目的 :上肢运动神经诱发电位 (MEP)记录及分析方法。方法 :采用电磁刺激技术跨颅刺激大脑皮质运动区（ Cz）及颈脊髓神经根（ C7）,在拇短展肌 (APB)及小指展肌 (ADM)肌腹处记录复合肌肉动作电位（ CMAP）。结果：健康人 MEP正常值： Cz－ APB潜伏期左右两侧分别为 25.23ms和 25.19ms,两侧潜伏期差为 2.24ms,两侧波幅比和面积比分别为 0.45和 0.37。 C7－ APB潜伏期左右两侧分别为 16.46ms和 16.73ms,两侧潜伏期差为 1.60ms,两侧波幅比和面积比分别为 0.49和 0.39,两侧中枢传导时间（ CCT）分别为 11.79ms和 11.75ms,两侧差为 2.00ms。 Cz－ ADM潜伏期左右两侧分别为 25.18ms和 24.80ms,两侧潜伏期差为 1.82ms,两侧波幅比和面积比分别为 0.47和 0.46。 C7－ ADM潜伏期左右两侧分别为 16.70ms和 17.44ms,两侧潜伏期差为 1.69ms,两侧波幅比和面积比分别为 0.41和 0.42,两侧中枢传导时间（ CCT）分别为 11.71ms和 11.80ms,两侧差为 1.86ms。结论：健康人跨颅电磁刺激 MEP潜伏期具有相对的稳定性及良好的重复性,可作为神经电生理学检测的一个可靠指标,但波幅及面积变异性较大,能否作为一个可靠的检测指标尚有待于进一步研究。     

Regional distribution of cocaine in postmortem brain of chronic human cocaine users

We measured concentrations of cocaine and its major metabolites (benzoylecgonine, ecgonine methylester, norcocaine, and cocaethylene) in 15 autopsied brain regions of 14 human chronic cocaine users. Only slight differences were observed in concentrations of cocaine and its metabolites amongst the examined brain areas. Although it is likely that some postmortem redistribution of the drug must have occurred, our data are consistent with the possibility that behaviorally relevant doses of cocaine are widely distributed throughout the brain of humans who use the drug on a chronic basis. Consideration should therefore be given to the possible pharmacological and toxicological actions of cocaine in both striatal and extra-striatal brain areas in human users of the drug.     

Determining the state of the deceased during cardiopulmonary resuscitation from tissue distribution patterns of intubation-related lidocaine

The objective of this study was to determine whether the concentrations of lidocaine, used for endotracheal intubation, in body fluids and tissues reflect the state of the circulation of the deceased during cardiopulmonary resuscitation. The tissue distribution of lidocaine was investigated in seven individuals (Cases 1-7) who underwent medical treatment with endotracheal intubation using Xylocaine jelly (a 2% lidocaine hydrochloride preparation), before being pronounced dead. Six patients (Cases 1-6) had cardiopulmonary arrest on arrival at hospital. In Cases 1-4, there was no restoration of heartbeat during cardiopulmonary resuscitation. However, systemic distribution of intubation-related lidocaine was observed and the kidney-to-liver ratios of lidocaine were less than 1. In Cases 5 and 6, the heartbeat resumed temporarily with cardiac massage, and a kidney-to-liver lidocaine ratio greater than 1 was observed. In Case 7, where the patient was comatose upon admission to hospital, the kidney-to-liver ratio of lidocaine was also greater than 1. These phenomena were substantiated in animal experiments. Our results indicate that the absorption of tracheal lidocaine during the artificial circulation resulting from cardiopulmonary resuscitation results in a kidney to liver ratio of less than 1, whereas absorption during natural circulation gives a ratio greater than 1. The kidney-to-liver ratio of intubation-related lidocaine may give useful information on the state of a patient during cardiopulmonary resuscitation.     

Evaluation of ABO and Lewis genotypes using primer extension preamplification

There are some difficulties with blood typing from ABO variant bloodstains and Lewis negative samples using serologic methods. In these samples, DNA analysis should be employed simultaneously to avoid errors in typing. Primer extension preamplification (PEP) produces copies of template DNA. The minimum quantity to examine nucleotide substitutions of ABO and Lewis genotypes by PCR ranged from 1 to 3 ng DNA. The PCR products with or without PEP treatment showed identical ABO and Lewis genotyping results. Performing both serologic and PCR testing served to crosscheck the ABO and Lewis grouping of such specimens. Errors in ABO and Lewis typing can be avoided as discrepancies are investigated further. The application of the PEP method to limited amounts of DNA samples for ABO and Lewis blood groupings is useful.     

Molecular cloning and immunohistochemical localization of rat dipeptidyl peptidase III

Dipeptidyl peptidase III (DPP III) was purified to homogeneity from rat liver cytosol. The calculated molecular weight of the purified enzyme was 82845.6 according to TOF-MS, and 82000 on non-denatured PAGE and 82000 on SDS-PAGE in the absence or presence of beta-ME. These findings suggest that the enzyme assumes a monomeric form in rat liver cytosol. The enzyme rapidly hydrolyzed the substrate Arg-Arg-MCA and moderately hydrolyzed Ala-Arg-MCA in a pH range of 7. 5 to 9.5. The K(in), K(cat) and K(cat)/K(m) values of DPP III at optimal pH (pH 8.5) were 290 microM, 18.0 s(-1) and 6.21x10(4) s(-1)M(-1) for Arg-Arg-MCA and 125 microM, 4.53 s(-1) and 3.62x10(4) s(-1)M(-1) for Ala-Arg-MCA, respectively. DPP III was potently inhibited by EDTA, 1,10-phenanthroline, DFP, PCMBS, NEM, beta-ME and iodoacetamide. Furthermore, we screened a rat liver cDNA library using affinity-purified anti-rat DPP III rabbit IgG, and we determined the cDNA structure and deduced the amino acid sequence. The cDNA designated as lambdaRDIII-11 is composed of 2640 bp of nucleotides in length and encodes 738 amino acids in the coding region. Although the enzyme has a novel zinc-binding motif, HEXXXH in structure, DPP III is thought to belong to family 1 in clan MA in the metalloprotease kingdom. These findings suggest that DPP III is a metalloprotease that is probably regulated by SH modification. The DPP III antigen was extensively detected in the cytosol of various rat tissues by the immunohistochemical examination of the protein.     

Immunohistochemical examination of the lungs in infant death cases using antibodies against milk components

To examine the use of immunohistochemical staining with antibodies against milk components for detection of aspirated milk on lung sections, eighteen infant death cases were investigated. Immunostaining was performed with anti-human alpha lactalbumin, anti-human IgA, anti-human milk fat globulin 1, and anti-cow whey antibody. Reactivity with each antibody was examined, and semi-quantitative examinations were performed to compare the amount of aspirated milk using anti-human alpha lactalbumin antibody. Materials in the alveoli or bronchioli on lung sections suspected to be aspirated milk showed the most sensitive and clearest reaction with anti-human alpha lactalbumin antibody. Of the eighteen cases, ten cases showed positive reaction with this antibody. The amount of aspirated milk varied widely in each case. In conclusion, immunohistochemical staining with antibodies against human milk components, especially anti-human alpha lactalbumin antibody, can detect small amounts of milk. Using this method, we were able to compare the relative amount of aspirated milk among cases.     

Influence of bleaching on stability of benzodiazepines in hair

In order to study the influence of hair bleaching on benzodiazepines concentrations, hair was treated with a bleaching product (Poly Blonde, Schwarzkopf & Henkel) for 20 min. The treated hair specimen was obtained from a person who died after an overdose of several illicit drugs associated with benzodiazepines. Bleached and non bleached hair were washed (acetone and water), pulverised and then incubated for 2 h in a thioglycolic solution. In the extracts obtained by solid-phase extraction on C18 columns, the different drugs with the corresponding deuterated standards were derivatized and determined by GC-MS in a SIM mode. These results show that the concentrations of all the drug detected decreased in bleached hair in comparison with non treated hair. Whereas the diminution was less important for cocaine and benzoylecgonine (decrease of 24.6 and 36.4%, respectively), concentrations for codeine, 6-monoacetylmorphine and morphine decreased more significantly (decrease of 57.5, 88.6 and 67.4%, respectively) as well as those of diazepam, nordazepam and 7-aminoflunitrazepam (decrease of 39.7, 67.7 and 61.8%, respectively). The results in this study agree with those of other authors that bleaching affects the stability of cocaine and opiates incorporated in hair. These findings also point out that bleaching influences the stability of entrapped benzodiazepines in hair. Finally, these results reconfirm that it is very important to consider the cosmetic history of a hair sample in the interpretation of hair analysis results.     

涉及死亡医疗纠纷的发生:27年医疗纠纷法医尸检回顾性研究之一

为了探讨医疗纠纷法医尸检的特点,回顾性研究了1972～1998年27年间318例医疗纠纷尸检资料.在这第一篇报告中,介绍与死亡有关医疗纠纷发生上的一些特点:医疗纠纷尸检的案例数从1972～1983年的23例上升到1984～1998年的295例;死者中男女性别无显著差别;年龄分布有两个高峰,10岁以下有104例(32.71%),20～40岁组161例(50.63%);发生在市(县)级中等大小医院的纠纷最多见,有195例,占61.32%,近年私人诊所的医疗纠纷明显增多;医疗纠纷尸检最常涉及外科(71例,22.33%)和产科(58例,18.24%);也简略讨论了206例非医疗过失纠纷和99例医疗过失纠纷发生的原因.     

Estimation of age from the femur of Japanese cadavers

The purpose of this study is to estimate the age of cadavers by histomorphometry of the femur. Seventy-two Japanese males ranged from 43 days to 92 years old and 26 females ranged from 2 to 88 years old were used. The thickness of sections was adjusted at 50 to 70 microns by grinding with sand paper. The sections were not decalcificated. They were stained with Villanueva's bone staining powder and with thionin dye. Microradiographs of the sections were obtained by the soft X-ray apparatus. The area, maximum and minimum diameter, and perimeter of the perfect osteon and Haversian canal were measured. In addition, the type II osteon number, osteon fragment number, and area of triangle were also determined. All these parameters were examined by an image analyzer. The parameters of the osteon showed high correlation coefficient with age (magnitude of r > 0.77), while those of the Haversian canal were low (magnitude of r < 0.11). All parameters were subjected to multiple regression analysis for producing a multiple regression equation of age estimation. For the stepwise selecting method, the perimeter of osteon, maximum length of the Haversian canal and osteon fragment number were selected for the equation. Their multiple r2 and standard error of estimation were 0.8874 and 6.39, respectively. For the forward selection method, in addition to the above items, three parameters, the maximum length of Haversian canal, triangle area, osteon fragment number were selected. Their multiple r2 and standard error of estimation were 0.9484 and 4.884, respectively. Bone staining was useful to clarify the demarcation between osteon and fragment, leading to an increase in the accuracy of age estimation. However, the entire range from birth to 90 years was difficult to cover for precise age estimation.