The mechanism of experimental adipocere formation: substrate specificity on microbial production of hydroxy and oxo fatty acids

Studies are reported on microbial conversion of various unsaturated fatty acids to 10-hydroxy and/or 10-oxo fatty acids by Micrococcus luteus. Four fatty acids possessing cis-9-unsaturation produced 10-hydroxy and 10-oxo fatty acid products, but three enoic acids possessing trans-9-unsaturation or double bond(s) in other than the 9-carbon position were inactive as substrates. 10-Hydroxy palmitic and stearic acids were converted to the corresponding 10-oxo fatty acids, but the 10-oxo compounds were inactive as substrates. This indicates that the metabolic sequence of cis-9-enoic fatty acid by the microbial enzyme(s) is first converted to 10-hydroxy fatty acid and then to its 10-oxo compound.     

The mechanism of experimental adipocere formation: hydration and dehydrogenation in microbial synthesis of hydroxy and oxo fatty acids

The enzyme preparations from Flavobacterium meningosepticum solubilized by sonication catalyzed not only hydration of oleic acid to produce 10-hydroxystearic acid but dehydrogenation of this product. The mechanism of the hydration and dehydrogenation was proved by gas chromatography-mass spectrometry of 10-hydroxy and 10-oxostearic acids produced in the presence of D2O or H2(18)O. The activity of these enzymes was increased by preincubating Flavobacterium meningosepticum with oleic acid.     

The formation of early stage adipocere in submerged remains: a preliminary experimental study

In some circumstances, the presence of adipocere may retard decomposition and complicate postmortem interval estimation. This article explores the correlation between Accumulated Degree Days (ADD) and early stage formation of adipocere. Sixty wild rabbit (Oryctolagus cuniculus) carcasses were used in this experiment; a control group (N = 30) deposited directly on the ground surface and an experimental group (N = 30) completely submersed in water in individual buckets. Data (water and inner body temperature, pH, and total body score) were collected every 100 ADD. Results indicated that early stage adipocere is correlated to ADD and that its formation on submersed remains is more likely to occur after 630 ADD. Skin sloughing promoted the formation of adipocere. No adipocere was formed on any of the control group rabbits. This study also highlights the fact that multiple factors influence adipocere formation and it is suggested that further research needs to be conducted into this area.     

Marine taphonomy: adipocere formation in a series of bodies recovered from a single shipwreck.

Taphonomy of marine environments has been studied mostly from individual cases. The formation of adipocere, or "grave-wax," is an important indicator of the postmortem interval. In the present paper, the conditions and the timing of adipoceric formation are observed in a series of 15 cadavers recovered at different times, over a period of 433 days, from the same contained environment. Initial foci of adipocere on the subcutaneous tissue of the cadavers were detected as early as 38 days from the time of immersion in cold (10-12 degrees C) sea water. The discrepancies between our findings and previous reports on the correlation between time since death and decomposition stages in marine environments are discussed.     

Separation and identification of 9-chloro-10-methoxy (9-methoxy-10-chloro)hexadecanoic and octadecanoic acids in adipocere

Two homologs of 9-chloro-10-methoxy(9-methoxy-10-chloro) fatty acids were found in adipocere from the human neonate, and identified as 9-chloro-10-methoxy(9-methoxy-10-chloro)hexadecanoic acid and 9-chloro-10-methoxy(9-methoxy-10-chloro)-octadecanoic acid. The chemical structures of these compounds were confirmed by thinlayer chromatography, gas-liquid chromatography, gas chromatography-mass spectrometry, nuclear magnetic resonance spectrometry and elemental analysis. The adipocere contained approximately 7.2% 9-chloro-10-methoxy(9-methoxy-10-chloro) fatty acids in the total fatty acids.     

Isolation of blood caffeine as a model substance by enzymatic hydrolysis

Organic solvent extraction of toxic compounds from blood either directly or following precipitation of serum proteins yields only free fractions. It is proposed to dissociate toxin-protein complexes in blood samples by enzymatic hydrolysis. Model caffeine complexes in an albumin solution were treated by tripsin, chemotripsin, and papain. The best results were obtained using chemotripsin and papain with which 70.4 +/- 1.6% and 62.2 +/- 1.2% of the caffeine was isolated from blood compared with 45.6% by direct extraction. Validation characteristics of the proposed method are specified.     

Postmortem decomposition of neutral lipids. Use of modern methods of analysis (HPLC, capillary GC, GC-MS and NMR) in adipocere formation

The chemical composition of subcutaneous fats was analyzed in a corpse that had died from drowning. The skin of the cadaver examined postmortem showed different stages of adipocere. Samples from these regions were chemically compared with the fatty tissue of a person who had died recently. HPLC, GC, GC-MS, NMR (1H- and 13C-NMR), TLC and titrimetrical methods were used to evaluate the degree of decomposition. The fatty acid pattern of the triglycerides (TG) and the free fatty acids (FFA) obtained by TLC separation was also investigated. Some discrepancy was observed between the autopsy findings and the results of the chemical analysis. It is suggested that the autopsy should be supplemented by chemical analysis in order to describe the state of adipocere correctly.     

Evidence of adipocere in a burial pit from the foot and mouth epidemic of 1967 using gas chromatography-mass spectrometry

Gas-chromatography-mass spectrometry was used to characterise the fatty acids from soils and associated tissues excavated from a 1967 Foot and Mouth burial pit. Subcutaneous fats were mainly comprised of 55-75% palmitic acid, 17-22% stearic acid and 3-16% oleic acid as well as 5-7% myristic acid. The distribution of fatty acids confirmed that the tissues were decayed to adipocere. The loss of oleic acid to <3% in two of the decayed fats suggested advanced stages of adipocere. However, adipocere formation was limited in a third tissue sample recovered from greater depth. Inductively coupled plasma atomic emission spectrometry of the pore waters revealed a decrease in Ca concentration and concurrent increase in Na concentrations this suggested that insoluble calcium salt had formed through displacement of sodium. The use of fatty acid profiles from soils and soil interstitial pore waters provide complementary evidence of adipocere formation in foot and mouth burial pits.     

同时裂解甲基化气相色谱法快速鉴别人体脂肪及动植物油脂

采用同时裂解甲基化气相色谱法（SPM－GC），首次分析人体脂肪，并且观察人体脂肪、猪、鸡、牛、羊脂和豆油中7种脂肪酸的组份含量变化。根据7种主要脂肪酸（肉豆蔻酸、棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸和亚麻酸）甲酯的百分含量可有效地进行鉴别。结果表明：通过SPM－GC法分析油脂，可将传统的油脂酯化法时间由2个多小时缩短到1分钟左右。数据C．V．％＜4％，最小检测量为1．Oμg。最佳比例四甲基氢氧化按（TMAH）甲醇液（TMAH：甲醇＝1：10，V／V），可消除油脂中多不饱和脂肪酸的异构化和降解。     

Stable isotope ratios as a tool in microbial forensics--Part 1. Microbial isotopic composition as a function of growth medium

The stable isotope ratios of a seized pathogen culture could potentially reveal information about the environment in which the agent was produced. In this paper we describe general relationships between stable isotopes of carbon, nitrogen, and hydrogen in bacteriological culture media and spores of Bacillus subtilis, an endospore-forming soil bacterium. In numerous media that varied both in nutrient composition and water stable isotope ratios, medium to spore enrichment in carbon isotopes was 0.3 +/- 2.0% per thousand (parts per thousand), and in nitrogen, 4.5 +/- 0.7% per thousand. We achieved mass balance for the contribution of hydrogen isotopes from nutrients (70%) and water (30%) to spores in independent experiments by varying the isotope ratios of nutrients or water. A model was derived for predicting the isotope ratio values of spores from those in nutrients and water.     

The formation of an international environmental agreement as a two-stage exclusive cartel formation game with transferable utilities

We construct a two-stage exclusive cartel formation game with utility transfers to model the formation process of an international environmental agreement. Our results show that in the first stage of low degree of consensus, engaging in utility transfers by asymmetric countries will accomplish little. In contrast, in the second stage of higher degree of consensus, it is more likely for asymmetric countries to engage in monetary transfers to form the grand coalition, particularly if a small stable coalition has already been formed in the first stage. This article therefore provides a theoretical perspective to explain why it is more likely for some developed countries to initiate an IEA formation process by forming a small stable coalition first before engaging in monetary transfers to form the grand coalition with all the other countries. Such a perspective is consistent with the historical development of the Montreal Protocol and may also explain the difficulty for asymmetric countries to form the grand coalition at the beginning of the IEA formation process of the Kyoto Protocol.

Heart fatty acid binding protein as a marker for postmortem detection of early myocardial damage

Depletion of heart fatty acid binding protein (H-FABP) from cardiomyocytes with varying post-ischemia intervals was studied in acute myocardial infarction (AMI) model of rat, and 22 human autopsy cases were studied with streptavidin-peroxidase conjugated method (S-P). It was observed that as early as 15 min after ischemia, the depletion of H-FABP could be detected in model rats. With the ischemic time prolonged, the depletion of H-FABP was more and more evident. In all human cases with myocardial infarction, absent H-FABP staining could be found in infarcted area. And in some suspected early myocardial infarction cases, depletion of H-FABP staining could be demonstrated in areas that showed normal hematoxylin-eosin (HE) staining. The blood samples from model rats before ligation, at varying post-ischemia intervals and various postmortem time were measured for plasma concentration of H-FABP with enzyme-linked immuno-sorbent assay (ELISA) method. At 15 min after myocardial ischemia, the concentration of H-FABP was 4 times higher (546.0+/-85.3 microg/l) than that of the baseline level (103.7+/-94.1 microg/l). With the continuation of ischemic time, the concentration of H-FABP increased and peaked at 4 h (1953.5+/-405.3 microg/l), then decreased. The plasma concentration of H-FABP decreased slightly with postmortem time, but was still significant higher at any postmortem intervals than that of baseline level within 48 h after death. The results suggest that H-FABP staining can detect very early ischemic damages in human myocardium and the elevated plasma concentration of H-FABP in rat was an indicator of AMI, which was not affected by autolysis.     

Recidivism as a feedback process: An analytical model and empirical validation

A feedback model of the criminal justice system (CJS) incorporates the continuing input of people arrested for the first time (virgin arrests) and the recycling of individuals with prior arrests (recidivists). Such a model is needed to enable CJS planners to assess the impact of possible actions on the future arrests and system workloads. Using an empirically determined estimate of the number of virgin arrests in the U.S. as input to a feedback model of the CJS, recidivism parameters, probability of rearrest, and average time between arrests were estimated by matching the output of the model to the total arrests in the U.S. in the period 1960–70. The average deviation between the model output and total U.S. arrests was minimized at less than 4% when the probability of rearrest is equal to 0.875 and the average time between arrests equal to 1.1. years. The relative sensitivity of total arrests to changes in virgin arrests and the probability of rearrest are also presented.     

The incorporation of dyes into hair as a model for drug binding

The binding of charged substances from external aqueous media to hair has been investigated through the use of fluorescence microscopy. Eleven hair samples, reflecting various ethnic groups and cosmetic treatments, were tested. Rhodamine 6G, a cationic dye representative of drugs such as cocaine and opiates, showed incorporation throughout the hair of all samples except one. In contrast, fluorescein, an anionic dye representative of drugs such as THC carboxylic acid, was not readily incorporated. The incorporation of rhodamine 6G was faster for chemically 'straightened' and bleached African-American female hair than for untreated hair. Incorporation of rhodamine 6G followed a pH dependence, but an ionic strength dependence could not be established. These studies support three postulates: (1) electrostatic interactions explain the preferential binding of cationic drugs of abuse to hair; (2) the hair matrix, or the non-helical portion of hair, is accessible to external solutions and thus subject to contamination; and (3) cosmetic treatments may alter the helical portion of hair thereby increasing its accessibility to external contamination.     

GC/MS衍生化测定精浆中游离支链氨基酸和果糖

目的 建立人精浆中支链氨基酸和果糖的气相质谱衍生化分析方法.方法 精液样本液化离心后,按精子活率的临床标准分为正常组和非正常组,经TMS微波衍生化,GC/MS分析两组支链氨基酸、果糖衍生物含量差异.结果 正常组与非正常组的缬氨酸,亮氨酸,异亮氨酸在相对含量上均有一定差异.正常组3种氨基酸相对含量高于非正常组.果糖分析观察到同样的特征,正常组相对含量高于非正常组.结论 精子活率低的精浆样本仍可检出支链氨基酸和果糖,其差异有助于无精子、少精子精斑的法医学鉴别.     

Regional study of free fatty acids and free carnitine behavior in cardiac tissue in relation to different causes of death

The determination of free fatty acids (FFA) and free carnitine (FC) in seven different regions of the human heart has been done. The hearts used were classified into six groups according to the cause of death. The results show that these two parameters are useless in ascertaining the cause of death, although they can provide useful postmortem information about the duration of the agonal process.     

Evidence in support of self-declaration as a sampling method for the formation of sub-population DNA databases

Well constructed sub-population databases are fundamental to the application of DNA-based forensic statistics. The size of such databases can affect the ability to examine adequately statistical or population genetic features, and the integrity of both the DNA profile and associated ethnicity information is also of importance. Use of short tandem repeat (STR) DNA profiling technology and the thoughtful construction of the governing legislation has seen large databases of DNA profiles collated for the four major sub-populations of New Zealand. Examination of the data illustrates the suitability of self-declaration as a means of categorizing samples on the basis of ethnicity.     

Food labeling: health claims; omega-3 fatty acids and the risk in adults of cardiovascular disease--FDA. Interim final rule

The Food and Drug Administration (FDA) is issuing an interim final rule to prohibit the use on foods of a claim relating to the relationship between omega-3 fatty acids and the risk in adults of cardiovascular disease. This interim final rule is in response to a notification of a health claim submitted under section 303 of the FDA Modernization Act of 1997 (FDAMA). FDA has reviewed statements that the petitioner submitted in that notification, and, in conformity with the requirements of FDAMA, the agency is prohibiting the claim because the statements submitted as the basis of the claim are not "authoritative statements" of a scientific body, as required by FDAMA; therefore, section 303 of FDAMA does not authorize use of this claim. As provided for in section 301 of FDAMA, this interim final rule is effective immediately upon publication.