A preliminary study on postmortem interval estimation of suffocated rats by GC-MS/MS-based plasma metabolic profiling.

Estimation of postmortem interval (PMI) is an important goal in judicial autopsy. Although many approaches can estimate PMI through physical findings and biochemical tests, accurate PMI calculation by these conventional methods remains difficult because PMI is readily affected by surrounding conditions, such as ambient temperature and humidity. In this study, Sprague-Dawley (SD) rats (10 weeks) were sacrificed by suffocation, and blood was collected by dissection at various time intervals (0, 3, 6, 12, 24, and 48 h; n = 6) after death. A total of 70 endogenous metabolites were detected in plasma by gas chromatography-tandem mass spectrometry (GC-MS/MS). Each time group was separated from each other on the principal component analysis (PCA) score plot, suggesting that the various endogenous metabolites changed with time after death. To prepare a prediction model of a PMI, a partial least squares (or projection to latent structure, PLS) regression model was constructed using the levels of significantly different metabolites determined by variable importance in the projection (VIP) score and the Kruskal-Wallis test (P < 0.05). Because the constructed PLS regression model could successfully predict each PMI, this model was validated with another validation set (n = 3). In conclusion, plasma metabolic profiling demonstrated its ability to successfully estimate PMI under a certain condition. This result can be considered to be the first step for using the metabolomics method in future forensic casework.

Analysis of Thermal Behavior of Crystalline Minerals in Bituminous Coal Samples under Air and Argon Atmospheres.

The thermal behavior of ash components in two bituminous coal samples [Upper Freeport (the "UF") and Illinois #6 (the "IL")] was investigated under air and argon atmospheres in the temperature range of 800-1200 °C using thermal gravimetric-differential thermal analysis, X-ray diffraction transmission electron microscopy (TEM), and TEM-energy dispersive X-ray spectrometry measurements. The UF treated under air formed the needle-like crystals which were assumed to be mullite-related substances formed by transformation of andalusite, because the crystals are mainly composed of SiO2 and Al2O3. In contrast to the UF, the IL did not generate such crystals; however, when the IL was treated under air after carbonization under Ar, crystals appeared. The composition of the UF with an Al/Si ratio higher than that of the IL favored the formation of mullite-related substances, while the presence of lime in the IL inhibited the formation of mullite-related substances. Oldhamite was formed by the reaction of lime with sulfur at the carbonization of the IL under Ar and remained even at the successive air treatment. As lime was consumed, the formation of mullite-related substances was ceased to be inhibited under air after Ar treatment.

Detection of butane gas inhalation at 16days after hypoxic encephalopathy: A case report.

In Japan, there are increasing reports of death by poisoning following butane abuse. To determine the specific cause of death in such cases, it is important to confirm the presence of fuel gas components in the body, although careful analysis is required because of their volatile properties. In most reported cases, the subject died suddenly during or immediately after butane aspiration. Thus, the butane concentration in the samples from the deceased should be relatively high. Herein, we present a case of an 18-year-old man found with cardiopulmonary arrest, who then exhibited hypoxic encephalopathy for 16days in a hospital. At autopsy, we detected hypoxic encephalopathy, pneumonia, and ischemia-reperfusion injury of the myocardium, while the cause of cardiac arrest remained unclear. Toxicological analysis was then performed for fuel gas components in several specimens collected at autopsy. Results showed that n-butane and isobutane were detected in the adipose tissue at 16days after inhalation, indicating a role of butane gas inhalation as the cause of death. These data suggest that adipose tissue may be the most appropriate analysis sample to be collected at postmortem in cases where involvement of volatile and fat-soluble gas inhalation is suspected.

A rare case of steering wheel injury causing coronal-plane pancreatic lacerations.

The incidence of pancreatic injury after blunt abdominal trauma is extremely low. A timely and accurate diagnosis is important, as a delay could be life-threatening. In this case, a 70-year-old driver crashed a car into a concrete wall at low speed. He was transported to the emergency hospital but died about 9.5h later with the cause of death unknown. An autopsy revealed that his pancreas was lacerated in the coronal plane and there was mesenteric contusion. Cause of death was determined to be blood loss resulting from pancreatic and mesenteric contusion. The mechanism of the injury was considered to be a very rare "degloving," caused by the impact from the steering wheel. It is therefore important to keep in mind possible pancreatic damage when examining blunt trauma to the abdomen, especially in traffic accident cases.

Rhodium-Catalyzed Reaction of Aroyl Chlorides with Alkynes.

Aroyl chlorides react with terminal alkynes accompanied by decarbonylation in the presence of a catalytic amount of [RhCl(cod)](2) and PPh(3) to give the corresponding vinyl chloride derivatives regio- and stereoselectively in good yields. The catalyst efficiency is a marked function of the ratio of PPh(3) to the rhodium species; satisfactory results are obtained by employing a PPh(3)/Rh ratio of 1.0. The reaction may involve chlororhodation to the alkynes by the intermediary arylchlororhodium(III) species generated in situ followed by reductive elimination of the products, which are suggested by the results of some control experiments. In contrast to the reaction with terminal alkynes, that with some internal ones proceeds without decarbonylation to produce 2,3-disubstituted-1-indenones as the predominant products. The product structures suggest that, while the arylchlororhodium intermediate is also involved, arylrhodation to the alkynes, reinsertion of CO (coordinated to the metal), and intramolecular cyclization sequentially take place to give the indenones.

Traumatic basal subarachnoid hemorrhage suspected to have been caused by contrecoup cerebellar contusions: a case report.

Traumatic cerebellar hemorrhagic contusions are infrequent, and the pathogenic mechanism involves a coup injury that is associated with motor vehicle accidents in most cases. Traumatic basal subarachnoid hemorrhage (TBSAH) is commonly reported after blunt trauma to the neck or unrestricted movement of the head, and the source of the hemorrhage is most frequently identified in the vertebrobasilar arteries. A 55-year-old woman who was addicted to alcohol was found dead in her bed. She had a bruise on the left side of her posterior parietal region, and autopsy revealed massive subarachnoid hemorrhage at the base of the brain; the hematoma was strongly attached to the right lower surface of the cerebellar hemisphere. No ruptured cerebral aneurysms, arteriovenous malformations or vertebrobasilar artery leakage were detected. Hemorrhagic cerebellar contusions were regarded as the source of the TBSAH. This is the first report of TBSAH suspected to have been caused by contrecoup cerebellar contusions.

Synthesis of tetrasubstituted naphthalenes by palladium-catalyzed reaction of aryl iodides with internal alkynes.

The 1:2 coupling of aryl iodides with acetylenedicarboxylate esters and diphenylacetylene efficiently proceeds in the presence of a palladium catalyst with use of silver carbonate as base to produce the corresponding tetrasubstituted naphthalenes.

Iridium-catalyzed reaction of aroyl chlorides with internal alkynes to produce substituted naphthalenes and anthracenes.

Benzoyl chlorides efficiently react with 2 equiv of dialkylacetylenes as well as diphenylacetylene in the presence of an iridium catalyst accompanied by decarbonylation to produce 1,2,3,4-tetrasubstituted naphthalenes in good yields. Use of 2-naphthoyl chlorides selectively affords the corresponding anthracene derivatives.

Palladium-catalyzed multiple arylation of thiophenes.

Secondary 2-thiophenecarboxamides efficiently undergo unique triarylation accompanied by formal decarbamoylation under palladium catalysis. 3-Substituted thiophenes, especially having an electron-withdrawing group, can also be triarylated.

Palladium-catalyzed dehydroarylation of triarylmethanols and their coupling with unsaturated compounds accompanied by C-C bond cleavage.

Triarylmethanols are effectively dehydroarylated and reacted with some unsaturated compounds by using an appropriate palladium catalyst system such as Pd(OAc)2-P(1-Nap)3 (1-Nap = 1-naphthyl) to give the corresponding arenes and hydroarylation products, respectively, along with diaryl ketones.

Palladium-catalyzed reaction of 2-hydroxy-2-methylpropiophenone with aryl bromides: a unique multiple arylation via successive C-C and C-H bond cleavages.

2-Hydroxy-2-methylpropiophenone undergoes a unique multiple arylation via C-C and C-H bond cleavages upon treatment with excess aryl bromides in the presence of a palladium catalyst to give 1,1,2,2-tetraarylethanes and 4,4-diaryl-1-phenylisochroman-3-ones.

Palladium-catalyzed arylation of alpha,alpha-disubstituted arylmethanols via cleavage of a C-C or a C-H bond to give biaryls.

The palladium-catalyzed arylation of alpha,alpha-disubstituted arylmethanols with aryl halides proceeds not only via C-H bond cleavage at the ortho-position, but also via cleavage of the sp(2)-sp(3) C-C bond with the liberation of ketones (beta-carbon elimination) to give the corresponding biaryls. Both reactions appear to occur through common arylpalladium(II) alcoholate intermediates. The results of systematic studies with respect to which C-C or C-H bond is preferentially cleaved in the arylation are reported. Among the important findings is the selective elimination of ortho-substituted aryl groups even from aryl(diphenyl)methanols due to steric reasons. Thus, various biaryls having ortho-substituents can be produced efficiently by treatment of the corresponding aryl(diphenyl or dimethyl)methanols with aryl bromides and chlorides.