Do organic substances act as a degradable binding matrix in calcium oxalate kidney stones?

BACKGROUND: Calcium oxalate (CaOx) stones are considered to be highly resistant to chemolysis. While significant organic matter has been identified within these stones, which is presumed to bind (inorganic) CaOx particles and aggregates, most chemolysis efforts have focused on methods to attack the CaOx components of a stone. We examine the feasibility of inducing chemolysis of CaOx kidney stones, within hours, by specifically attacking the organic matrix present in these stones. METHODS: In contrast to previous studies, we focused on the possible "brick and mortar" stone configuration. We systematically tested, via in vitro experiments, the ability of an extensive range of 26 potential chemolysis agents to induce relatively fast disintegration (and/or dissolution) of a large set of natural CaOx stone fragments, extracted during endourological procedures, without regard to immediate clinical application. Each stone fragment was monitored for reduction in weight and other changes over 72 h. RESULTS: We find that agents known to attack organic material have little, if any, effect on stone chemolysis. Similarly, protein and enzymatic agents, and oral additive medical treatments, have little immediate effect. CONCLUSIONS: These findings suggest that the organic and inorganic constituents present in CaOx stones are not structured as "brick and mortar" configurations in terms of inorganic and organic components.

Usefulness of unenhanced post mortem computed tomography - Findings in postmortem non-contrast computed tomography of the head, neck and spine compared to traditional medicolegal autopsy.

INTRODUCTION/BACKGROUND: Post-mortem CT (PMCT) is becoming an essential tool available to forensic pathologists worldwide, but its validity with respect to evidence for legal purposes still requires more comprehensive large-scale studies, comparing PMCT to autopsy. This article compares PMCT and autopsy findings of the head, neck, and spine during a period of five years. MATERIALS AND METHODS: The study included 203 cases for which both autopsy and PMCT were performed. All relevant findings were extracted from the reports and divided into 30 categories based on anatomical location and tissue characteristics. Data were evaluated quantitatively in a binary fashion. RESULTS/FINDINGS: A high level of agreement was noted for skull fractures, intraventricular- and subarachnoid hemorrhages, bullet trajectories, and intracranial shrapnel. A fair correlation was demonstrated for brain atrophy or herniation, and findings in the facial soft tissues. PMCT had higher sensitivity to brain edema, presence of gas in tissues or cavities, and findings in the spinal column and spinal canal, whereas autopsy better demonstrated pathologies in the brain tissue, hemorrhages in the neck and fractures of the larynx and hyoid bone. A relatively low correlation was noted for subdural and epidural hematomata. CONCLUSIONS/INTERPRETATION: For several locations, structures, and specific findings in the head, neck and spine, autopsy remains indispensable. However, PMCT better demonstrated some findings in locations that are difficult to access by autopsy, or structures that might be damaged due to autopsy procedure. For the examinations of these, PMCT may in specific cases serve as an alternative to autopsy. Generally, however, due to the vast and fundamental differences that distinguish each case from the next, and the different purposes that autopsy may serve, we propose that the decision as to which method (or a combination of both) should be used, be made according to the circumstances and expected findings of each case.