Takehiko Takatori

The mechanism of adipocere formation 1. Identification and chemical properties of hydroxy fatty acids in adipocere

The hydroxy fatty acid purified from the adipocere, m.p. 78.5 degrees -79.0 degrees C, was optically inactive and the adipocere contained about 3 to 20% hydroxy fatty acid of the total fatty acids. The melting point of the hydroxy fatty acid was nearly identical with that of the 10-D, L-hydroxyoctadecanoic acid synthesized organically, suggesting that the hydroxy fatty acid in the adipocere appears to be converted non-enzymatically. In the adipocere two hydroxy fatty acid components were detected by gas-liquid chromatography (GLC). The major and minor components were identified as 10-hydroxyoctadecanoic and 10-hydroxyhexadecanoic acids, respectively, by gas chromatography-mass spectrometry (GC-MS). These hydroxy fatty acids found in the adipocere appear to play an important role on the formation of adipocere.

Microbial production of hydroxy and oxo fatty acids by several microoganisms as a model of adipocere formation

Some varieties of aerobic or anaerobic microorganisms from the human stool and adipocere were separated and identified. These separated microorganisms together with other authentic ones produced 10-hydroxystearic acid from oleic acid. Some bacteria could convert oleic acid to 10-oxostearic acid as well as 10-hydroxystearic acid. These findings indicate that the microbial enzyme(s) catalyzes the hydration of oleic acid and probably the oxidation of this hydrated product. Aerobic bacteria as well as anaerobic microorganisms were found to be involved in the formation of adipocere.

Estimating stature from the length of the lumbar part of the spine in Japanese.

In order to estimate the stature from the length of the lumbar part of spine (LLPS), studies were made on Japanese males (n=42) and females (n=29) autopsied in our laboratory during 1984–1987. Somatometry was performed on the stature and LLPS in centimetres, the latter being measured from the upper edge of the first lumbar vertebral body, to the promontorium, along the anterior surface of the spine. LLPS were 19.9 ± 1.19 cm in males and 18.6 ± 0.84 cm in females (mean ± S.D.). The regression equations calculated were as follows: stature in males = LLPS × 3.23 + 101.7; stature in females = LLPS × 2.31 + 110.8. The standard errors of estimate were 6.16 cm in males and 4.05 cm in females. This method is useful for estimating the stature of severely burned or mutilated bodies which have no limbs.

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.

Induction of methamphetamine-specific antibody using biodegradable carboxymethyl-chitin

Induction of a specific antibody for methamphetamine, an antihypnotic drug, has been studied using carboxymethyl-chitin (CM-chitin) as a hapten carrier. The hapten-specific antiserum was induced by only a couple of hypodermal injections every 2 weeks. Inhibition of antigen-antibody complex formation was linearly related to methamphetamine concentration in the range 0.5 to 50 ng/50 microliter when an enzyme-linked immunosorbent assay was performed using an avidin-biotin-peroxidase complex. Little antibody directed against CM-chitin and CM-chitin oligomer was detected. Thus it seems to be advantageous in the hapten-bovine serum albumin system. The specificity of the antibody was high as shown by the use of various methamphetamine analogs.

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.

An ELISA using avidin-biotin complex for the determination of ABH group from saliva

The ABH group in a trace amount of saliva could be determined by an enzyme-linked immunosorbent assay (ELISA) using an avidin-biotin-peroxidase complex (ABC) technique. In this method ABH blood group substances as a solid phase are adsorbed to wells of a microtiter plate made of polystyrene. The primary antibody corresponding to the blood antigen adheres onto the wells, and reacts with the biotinylated secondary antibody. The previously formed ABC reagent is then added to the above wells, and finally the absorbance produced by the interaction of the peroxidase activity with a chromogenic substance is measured at 492 nm. This method proved to be clearly more sensitive for the detection of ABH blood groups in secretor-saliva than the conventional hemagglutination inhibition test. Also the ABH group of non-secretor-saliva could be easily determined by this method.

Immunohistochemical localization of paraquat in lung and brain.

In order to observe the localization and dynamics of paraquat in lung and brain, immunohistochemical approaches were conducted by using animals. Experimental paraquat-poisoned rats were sacrificed 3 hours, 12 hours, 24 hours, 3 days, 7 days and 10 days after intravenous administration of paraquat (5 mg/kg). In lung tissues, paraquat was localized in histiocytes, walls of blood vessels and bronchiolar epithelial cells from 3 hours to 10 days after the paraquat exposure, and interstitial pulmonary fibrosis was being developed with time. On the other hand, in brain tissues, paraquat was localized only in capillary walls and glial cells but not observed in nerve cells 10 days after the administration of paraquat.

Death due to a methane gas explosion in a tunnel on urban reclaimed land

Studies of four male victims who were killed in an accidental tunnel gas explosion on urban reclaimed land are described. The studies were judicial autopsy examinations to determine the precise causes of death. Two men died of carbon monoxide intoxication, one died of massive brain damage, and the fourth died of drowning. The concentrations of methane in several organs were much lower than the lethal level, whereas those in adipose tissue were relatively high. These findings indicated that a low concentration of methane was almost always present in the atmosphere at the construction site. Recently, coal mine accidents have been decreasing in Japan. However, there is still a possibility of underground explosions or gas leaks in confined spaces other than coal mines. To determine the precise cause of death in such cases, careful autopsies and other examinations should be performed using methods similar to those used in coal mine accidents.

Methane asphyxia. Coal mine accident investigation of distribution of gas.

Death from asphyxia due to substitution of air by methane gas may occur in coal mine by gas outburst. In such a case, it is required to determine methane gas contents from cadaveric blood and tissues for diagnosing cause of death and estimating conditions of the accident.The methane concentration in blood and tissue samples of 22 male victims by a gas outburst accident was measured by gas chromatography. The level of methane in the cardiac blood was in the range of 6.8–26.8 μliter/g.As a model of gas outburst in coal mine, rats were exposed experimentally to various concentrations of methane. Their course of death and methane distribution in the bodies were observed. From these findings, diagnostic criteria for asphyxia from substitution of air by methane are also discussed.