Bioluminescent assay of microbial ATP in postmortem tissues for the estimation of postmortem interval

Exploring microbial communities, assessment methodologies and applications of animal's carcass decomposition: a review

Animals are an essential part of the ecosystem, and their carcasses are the nutrient patches or hotspots where nutrients accumulate for a long time. After death, the physical and chemical properties undergo alterations inside the carcass. The animal carcass is decomposed by many decomposers such as bacteria, fungi, microeukaryotes and insects. The role of microbial symbionts in living organisms is well explored and studied, but there is a scarcity of knowledge and research related to their role in decomposing animal carcasses. Microbes play an important role in carcass decomposition. The origins of microbial communities associated with a carcass, including the internal and external microbiome, are discussed in this review. The succession and methods used for the detection and exploration of decomposition-associated microbial communities have been briefly described. Also, the applications of carcass-associated microbial taxa have been outlined. This review is intended to understand the dynamics of microbial communities associated with the carcass and pave the way to estimate postmortem interval and its role in recycling nutrients.

Evaluation of Cytotoxic Potentials of Novel Cyclooxygenase-2 Inhibitor against ALL Lymphocytes and Normal Lymphocytes and Its Anticancer Effect through Mitochondrial Pathway

In the present study, we searched selective cytotoxicity and mitochondria mediated apoptosis of novel COX-2 inhibitor 2-(4-(Methylsulfonyl)phenyl)imidazo[1,2-a] pyridine-8-carboxylic acid on B-lymphocytes and their mitochondria isolated from normal subjects and acute lymphoblastic leukemia (ALL) patients' blood. Our results showed this compound can selectively induce cellular and mitochondrial toxicity on ALL B-lymphocytes and mitochondria without any toxic effects on normal B-lymphocytes and their mitochondria. Taken together, the results of this study suggest that cancerous mitochondria are a potential target for the ALL B-lymphocytes. Selective toxicity of COX-2 inhibitor in cancerous mitochondria could be an attractive therapeutic option for the effective clinical management of therapy-resistant ALL.

Interpolation function estimates post mortem interval under ambient temperature correlating with blood ATP level

OBJECTIVE

We developed a mathematical model using interpolation function, to characterize the correlation between blood ATP levels in the right ventricle of rabbit and post mortem interval (PMI) at different ambient temperatures.

METHODS

Forty-eight healthy rabbits were randomly divided into 6 groups of 8 each. The sacrificed rabbits were maintained in calorstats at 10°C, 15°C, 20°C, 25°C, 30°C and 35°C, respectively. Blood from the right ventricle was sampled every 4h until 72h after death. At different time points, ATP concentrations in the blood samples were measured using an ATP fluorescence rapid detector, and then displayed on the detector screen in the form of relative light units (RLU). Relationship between PMI and ATP degradation levels was investigated statistically by SPSS 17.0 and MATLAB 10.0 software.

RESULTS

We obtained six regression equations (Ra(2)=0.887-0.929) with RLU values at PMIs of 72h (10°C), 60h (15°C), 56h (20°C), 52h (25°C), 40h (30°C) and 32h (35°C), and an interpolation function (Ra(2)=0.930) was established with PMI as the dependent variable (z), RLU value as independent variable (x) and temperature as independent variable (y).

CONCLUSION

Interpolation function is an appropriate choice for PMI estimation by weakening influence of ambient temperature.

Estimating postmortem interval using RNA degradation and morphological changes in tooth pulp

The accurate determination of time since death, or postmortem interval (PMI), can be critical in the investigation of suspicious deaths. Knowing when a suspicious death occurred can limit the number of potential suspects to those without a viable alibi for the time of the crime. The forensic techniques currently employed to determine PMI: pathology, entomology, and anthropology, are accurate over different time periods following death. A large gap in time exists between the capabilities of forensic entomology and traditional anthropology, leaving a period in which PMI is difficult to estimate. In this study, time-dependent differences in RNA decay rates were examined to extend the time frame over which early PMI estimates can be made. Comparing the decay rates of a large, labile segment of β-actin RNA and a smaller, more stable, non-overlapping segment of the same RNA from tooth pulp, we were able to estimate PMI values of pigs buried within a shallow grave for up to 84 days. This compares favorably to an estimate of PMI using insect data. Full skeletonization and loss of insect activity was observed by day 28 of our study. In addition to differences in RNA decay rates, morphological changes were observed in the pulp as it aged postmortem. To provide a quantitative measure of progressive color changes, analysis of digital photographs of each tooth's pulp were used to construct a simple colorimetric assay. This assay was then used to cluster ages of pulp samples by color. The two assays, used in combination with one another, can create a more precise estimate of PMI. The potential advantages of this molecular means of estimating PMI include extending the time frame for such estimates, is applicable to samples collected worldwide (no specialized knowledge of local insect fauna is required), is relatively fast, and inexpensive.