Methanol Detected in a Subdural Hematoma as an Embalming Artifact.

Analysis of subdural hematomata has been used to suggest antemortem drug concentrations, with the assumption that materials within the hematoma are less subject to metabolism or degradation during any survival period and postmortem interval. We report the case of an 87-year-old woman whose death had not been reported to the coroner's office until postembalming. Autopsy revealed a traumatic brain injury with subdural hematoma causing a mass effect. Testing of the clot indicated a methanol concentration of 51.8 mg%. No additional analyses were detected. These findings suggest that methanol can be present in a postmortem hematoma sample, yet not represent a poisoning. Our findings also suggest that while the interior of hematomata do not necessarily represent completely "protected space" from postmortem diffusion of some blood constituents, such diffusion is not facile, and analysis may still provide useful indications of antemortem drugs present, if not actual concentrations.

Formaldehyde scavengers function as novel antigen retrieval agents.

Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more effective antigen retrieval agents.

Study of effect of adsorptive building material on formaldehyde concentrations: development of measuring methods and modeling of adsorption phenomena.

UNLABELLED: In this paper, a method is developed to assess the performance of adsorptive building materials that are used for reducing indoor pollutant concentrations. Mass transfer has a great influence on the materials' performance. To control the mass transfer rate precisely in the performance test, the authors have developed the Boundary-Layer-Type Small Test Chamber in which airflow along the test materials can be controlled precisely. A new index of adsorption performance, the equivalent ventilation rate (Q(ads)), is defined that corresponds to the mass transfer coefficient when the surface pollutant concentration is zero. Modeling and experimental verification of adsorption were done, demonstrating the pollutant concentration decrease caused by adsorptive building materials. The pollutant reduction phenomena were modeled, including pollutant degradation by chemical reaction and adsorption in building materials. Adsorption tests of gypsum board containing a substance that decomposes HCHO within the board are reported. The adsorption rate of the gypsum board predicted by numerical analysis (CFD, Computational Fluid Dynamics) corresponds well with experimental results. PRACTICAL IMPLICATIONS: Development and verification of a method to measure the decrease in indoor pollutant concentration caused by an adsorptive building material are reported. Mass transfer has a great influence on the material's performance. The equivalent ventilation rate (Q(ads)) of the adsorption performance is defined as a new index that corresponds to the mass transfer coefficient. The equivalent ventilation rate (Q(ads)) can be used directly to compare the effect of pollutant concentration decrease via adsorption with the effect of ventilation.

Formaldehyde prepared from paraformaldehyde is stable.

For critical histological investigations, tissue fixation is sometimes carried out in formaldehyde freshly prepared from paraformaldehyde by heating. The purity of formaldehyde produced in this way is superior to that of commercial stock solutions. We studied the stability of freshly prepared formaldehyde solutions by determination of pH and titration of acid, which reflect the formation of formic acid. It was found that very small amounts of acid are produced during the heating of paraformaldehyde. Prolonged heating or storage of freshly prepared formaldehyde for up to 8 days did not significantly increase the amount of acid. It was also found that heating of the paraformaldehyde is not necessary, since depolymerization may take place at room temperature. We conclude that formaldehyde prepared from paraformaldehyde remains stable for considerable periods of time, and it is therefore unnecessary to prepare it immediately prior to fixation. Also, in many cases, buffering of the fixative may be omitted, since only minor changes in the pH occur during fixation.

A rapid method for obtaining monomeric glutaraldehyde.

A new method for the distillation of glutaraldehyde to obtain the monomeric form is presented. The monomer is obtained after only one distillation and it has a purification index (Pi) smaller than 0.20.