Determination of clofelin in blood by gas chromatography-mass spectrometry

Gas chromatography--mass spectrometry is proposed for measuring clofelin (clonidine) in cadaveric blood. The method includes liquid-liquid extraction of clonidine from the blood, derivatization with pentafluorobenzyl bromide, and subsequent purification of derivatization products before chromatographic analysis. The range of 0.5-50.0 ng/ml covers therapeutic and lethal concentrations of clonidine in the blood. The method was tried on expert material in Chelyabinsk Regional Bureau of Forensic Medical Expert Evaluations and can be used in forensic chemical and toxicological analysis.     

A simple spectrophotometric method for the determination of carboxyhemoglobin in blood

The spectrophotometric method for the determination of carboxyhemoglobin (HbCO) in blood reported by Fretwurst and Meinecke was modified so as to give the same values of percentage HbCO (HbCO%) as those determined by the oxygen electrode method. Values of HbCO% of nine practical samples determined by both the oxygen electrode method and the present method were nearly identical regardless of the presence of methemoglobin (Met-Hb) in blood. The present method is suitable for forensic practice.     

ELISA-based determination of opiates in purulent transformation of cadaveric material

Abuse of drugs has been a topical issue up to the present-day. Opiates like morphine and heroin are still prevalent. The routine methods of determination of drugs in blood made within the forensic medical expertise are time-consuming and samples must be specially prepared for them. ELISA, when used for the determination of opiates in blood and urine, significantly cuts the test time. According to our research results, the diagnosis of opiates by ELISA is advisable at the preliminary stage of the forensic expertise of cadaver; the method is informative, which is of extra importance in cases of purulent transformation of cadaveric material.     

The detection of beta-cypermethrin during forensic chemical expertise of biological materials

The optimal conditions for the isolation of beta-cypermethrin from biological materials by means of dioxane extraction have been developed. The possibility to purify beta-cypermethrin from endogenous impurities is demonstrated by combination of liquid-liquid extraction and chromatography through a silica gel column (L 40/100 mcm). It is shown that identification and quantitative determination of beta-cypermethrin extracted from the cadaveric liver tissues are possible using such techniques as thin-layer chromatography, electron spectrometry, and chromato-mass spectrometry. A method for forensic chemical expertise of the presence of beta-cypermethrin in biological materials is described.     

Gas chromatography with mass-selective detector in testing blood for amitriptyline and nortriptyline

The article describes the method of simultaneous detection of amitriptiline and nortriptilin in cadaveric blood using gas chromatography with mass-selective detection. Preparation includes liquid-liquid extraction and derivation with trifluoroacetic anhydride. Nortriptilin threshold of detectability in the blood is 0.02 mcg/ml, amitriptilin one--0.05 mcg/ml. The range of detectability--0.05-3.0 mcg/ml for both compounds. Maximal error of the compounds detectability was under 12.9% for concentrations 0.10 mcg/ml and 10.6% for concentrations 2.0 mcg/ml. The method was tested on expert material in forensic chemical examinations.     

Immunochemical methods in detection of opiates in tissues and organs

Conditions of isolation of opiates from tissues and analysis of the resultant extracts by immunochemical methods are discussed. The main characteristics of OPIATES U kits (Pharmatech) for polarization fluorescent immunoanalysis of cadaveric material (liver) are determined. Immunochemical methods for forensic chemical analysis for opiates are experimentally compared.     

Detection of 1,4-benzodiazepine derivatives in liver tissues by immunochemical methods

The possibility of using immunochemical methods in general forensic chemical analysis of cadaveric material for narcotics is demonstrated. Conditions of isolation of 1,4-benzodiasepines from tissues and analysis of the resultant tissue extracts by polarization fluoroimmunoassay (PFIA) and solid-phase enzyme immunoassay are described. Time course of concentrations in tissue extracts stored for a long time has been studied by PFIA. Characteristics of Benzodiazepines Serum kits (Abbott) for PFIA of liver extracts are determined.     

The determination of phoxim in cadaveric material by gas-liquid chromatography]

The developed gas-liquid chromatographic procedure for forensic chemical detection and measurement of phoxim in cadaveric material permits the detection in 25 g of an organ of 44 to 52% of added phoxim. The threshold of phoxim measurement in 100 g of the liver is 0.04 mg, the least volume of phoxim detectable being 0.02 g. The developed gas-liquid chromatographic technique should be used as an additional method together with thin-layer chromatography, for a more objective evaluation of the results of forensic chemical analysis of cadaveric material for phoxim.     

The determination of clozapine in blood and urine by gas chromatography-mass spectrometry]

A method for measuring closapine in the blood and urine by gas chromatography-mass spectrometry as a trifluoroacetic derivative is proposed. The threshold level for closapine detection is 25 ng/ml in the blood and 30 ng/ml in the urine. Calibration curves are linear in the range 0.025-5 mcg/ml for the blood and 0.03-50 mcg/ml for the urine. The method can be used in forensic chemical and clinical toxicological analysis.     

The forensic chemical analysis of cadaveric material for the presence of drug and narcotic compounds]

The authors consider that the list of drugs and narcotics which can be reliably identified in a general forensic chemical analysis of cadaveric material (not a purposeful screening) should be changed. Isolation by acidified water, hydrochloric acid hydrolysis, and by acetonitrile should be used for isolation of drugs and narcotic compounds in forensic chemical analysis of cadaveric material.     

The detection of isoniazide in the cadaveric blood and plasma by high performance liquid chromatography with a diode matrix detector

The authors describe the analytical procedure for the rapid detection of isoniazide in the cadaveric blood and plasma using high performance liquid chromatography with a diode matrix detector (HPLC-DAD). The method is designed for toxicological and forensic medical analyses. The preliminary preparation of the samples includes protein precipitation with trichloroacetic acid, formation of isoniazide derivatives with cinnamic aldehyde, and chromatographic analysis on an Eclipse XDB-C18 column with registration of absorption at a wavelength of 340 nm. The mobile phase is a mixture of methanol and 0.05 M ammonium acetate buffer (50:50 v/v), pH 3.8. The detection limit is 0.5 mcg/ml in plasma and 1 mcg/ml in blood hemolizate. The qualitative determination is possible in a concentration range from 2 to 200 mcg/ml. Mean square deviation does not exceed 12% in a concentration interval from 2 to 50 mcg/ml.     

Release of tissue paraquat into formalin solution during fixation

Formalin-fixed tissues and formalin solutions are among the most frequently found materials in pathology and forensic science laboratories. However, these materials are seldom used for the identification of poisons for forensic toxicology purposes. In this study, the possibility that paraquat may be released from formalin-fixed tissues during the fixation process was investigated. However, because of the interference of formaldehyde on the reduction of paraquat with dithionite reagent, paraquat in formalin solutions was treated with ion-pair column chromatography and then determined by measuring the derivative spectrum of reduced paraquat. The results show that the interference of formalin on paraquat determination has been eliminated by the proposed method. Furthermore, a study on the formalin solutions of fixed organs in cases with suspected paraquat intoxication revealed that portions of tissue paraquat had been released into formalin during the fixation process. Moreover, the paraquat levels in formalin increased with increased storage time. Therefore, these data suggest that the combined concentrations of paraquat in the formalin-fixed tissues and formalin solutions might reflect more reliably the total paraquat in the postmortem tissues. This investigation could be of value to the forensic toxicologist, especially in cases in which no fresh tissue samples are available for analysis.     

妇科肿瘤和乳腺癌组织常染色体和X染色体STR的突变分析

目的探讨妇科肿瘤组织和乳腺癌组织的法医学常用STR基因座突变类型和规律,以及显微切割技术在肿瘤组织法医学鉴定中的应用。方法应用Power Plex 21 System和Argus X-12试剂盒对62例乳腺癌患者,62例妇科恶性肿瘤患者,10例良性妇科肿瘤患者外周血、肿瘤组织和癌旁组织DNA样本进行复合扩增,获得STR分型,并选取存在突变的部分肿瘤组织进行显微切割。结果妇科恶性肿瘤患者外周血的STR分型与癌旁组织一致;46.77%的妇科恶性肿瘤组织中观察到4种STR突变类型,显著高于良性肿瘤的STR突变率(P0.01)和乳腺癌的STR突变率(P=0.009)。显微切割获得的间质细胞的STR分型与癌旁组织一致。结论本研究所检测的STR基因座在妇科恶性肿瘤组织中的稳定性较差,不适用于该系统肿瘤组织的法医学鉴定;显微切割技术可准确分离间质细胞,能够代表肿瘤来源个体的正常DNA分型,是解决此类案件法医学鉴定的一种有效方法。     

Postmortem methemoglobin concentrations and their significance

Small concentrations of methemoglobin are present in the blood of normal individuals. Increased concentrations of methemoglobin can be formed by the action of certain chemicals or drugs, or in individuals with specific genetic defects. There is little information available concerning the validity of postmortem methemoglobin concentration as an indicator of antemortem methemoglobinemia. We measured blood concentrations of methemoglobin in 49 autopsy specimens. We conclude that postmortem methemoglobin concentrations are not valid indicators of antemortem methemoglobinemia.     

Fatal doses and concentrations of drugs in biological objects

Information on the lethal doses and concentrations of drugs in biological objects is essential for the diagnosis of drug poisoning. Methods for measuring the concentrations of some drugs in the blood and urine have been developed and tables of lethal doses, concentrations, and metabolism coefficients for drugs most often occurring in forensic medical practice are offered. A method for estimating the drug dose which led to a lethal outcome is suggested.     

The determination of chromium in cadaveric material by using cyclohexanecarboxylic acid

Method of chrome detection in the course of forensic chemical investigation in the cadaveric material on the basis of cyclohexan-carbonic acid use is presented. Results of experimental researches showed efficacy of method tested as compared to the common one. Method suggested can be used in laboratory conditions to extract chrome from visceral organs of human cadaver.     

The chemical action of gun powder gases on biological tissues in a point-blank shot]

Chemical effect of gun powder gas on the biologic tissues manifests by red-brown staining of the tissues, mainly at the expense of methemoglobin and sulfhemoglobin. Scarlet staining of the tissues at the edges of gun-shot wounds is not a specific marker of a shot made from a short distance; it may emerge several hours after wounding at the expense of hydroxy-hemoglobin and is not at all related to the chemical effect of gun powder gas. The conditions conducive to scarlet staining are an open wound permitting free oxygenation by air oxygen and hemoglobin transfer from the injured red cells into blood plasma and adjacent tissues.     

Identification of fetal hemoglobin in blood stains by high performance liquid chromatography

A new method for the identification of fetal hemoglobin (Hb F) in blood stains by reverse-phase high performance liquid chromatography is described. Differentiation between fetal and adult blood stains is based on the existence of gamma-chain peaks which are characteristics of Hb F. Very few gamma chains appeared on chromatograms of all the adult blood stains examined. The level of Hb F could be determined by measuring the total of chromatogram gamma-globin chain areas, and expressing it as a percentage of total Hb. Levels in six cord blood stains on filter paper ranged from 81.1% to 91.3% and remained constant for at least 12 weeks. This method is of great value for its simplicity, sensitivity and speed, and most importantly for its reliability in the field of forensic medicine.     

颅内出血体积测量方法的比较

目的探寻一种能够运用于法医临床学实践的测量颅内出血量的方法。方法比较多田公式、体视学技术和软件边界法测量颅内出血的准确性,并比较它们的实用性。结果体视学法和软件边界法的测量值是准确的,而多田公式测量不规则血肿误差很大。结论体视学法是法医临床学中测量颅内出血量最适用的方法。     

Chemicals reacting with various forms of hemoglobin: biological significance, mechanisms, and determination.

The clinical chemistry of various forms of hemoglobin occupies a large fraction of the total activities of hospital and forensic science laboratories. Some of the potential pitfalls are reviewed here along with an account of the accidental discovery of two novel chemical forms. Human or mouse red blood cells were exposed to excess sodium nitrite to convert the intracellular pigment to methemoglobin. When these were subsequently incubated in Krebs-Ringer-phosphate-glucose medium, pH 7.4 at 37 degrees C under nitrogen and in the presence of various concentrations of methylene blue, a blood pigment was generated in high yield which had unique properties. In lysates, the pigment was stable in air, and it could be maintained in liquid nitrogen for as long as a year without deterioration. The pigment had properties different from those of oxyhemoglobin, deoxyhemoglobin, methemoglobin, or carboxyhemoglobin. After separation by isoelectric focusing, the pigment gave a strong signal on electron paramagnetic resonance (EPR) spectroscopy. The other forms of hemoglobin given above are EPR-silent. The pigment was eventually identified as the nitrosylated valency hybrid species, (alpha 2+ beta 3+)2(NO)2. The corresponding species, (alpha 3+ beta 2+)2(NO)2, has similar properties. These species apparently owe their unusual stability in air to the presence of the oxidized subunits in the same tetramer.