ABSTRACT
In forensic pathology, the estimation of postmortem interval （PMI） has always been a difficult issue, and there is still lack of effective methods to estimate PMI of corpses in water. Microbial biofilm refers to the microbial population attached to non-biological or biological surfaces by microorganisms during microbial growth, that has a three-dimensional structure, surrounded by extracellular polymers and matrix networks created by itself. A series of community succession phenomena of microorganisms occur during the occurrence and development of microbial population. The microbial community and its succession process of this kind of biofilm attached to the surface of a corpse in water may become a new basis for estimation of the PMI of corpses in water. This review elucidates on the concept, classification, research methods, and influencing factors of biofilm and analyzes its application prospects in PMI estimation of corpses in water, which would provide new ideas for the researches in this field.
Subject(s)
Humans , Autopsy , Biofilms , Cadaver , Drowning , Forensic Pathology/methods , Postmortem Changes , WaterABSTRACT
Human corpses can be found in a variety of aquatic environments. The decomposition of corpses in aquatic environments is different from those on land. A large number of factors influence the decomposition process in water, therefore postmortem submersion interval （PMSI） is difficult to estimate. To date, while studies on aquatic corpses are obviously fewer than those on terrestrial corpses, there are many problems in practical work. This review summarizes the stages and influencing factors of aquatic corpse decomposition, and introduces the relevant research progress of PMSI estimation based on decomposition stages, postmortem phenomena, aquatic insects, biofilm, and physical and chemical methods, in order to provide reference for aquatic decomposition researches and practices.
Subject(s)
Animals , Humans , Autopsy , Biofilms , Cadaver , Insecta , Postmortem Changes , WaterABSTRACT
Necrobiome is the main factor causing the cadaver decomposition. Studying the microbial succession during decomposition is one of the main tasks of forensic microbiology. The interactive relationships among cadaver, environment and microorganisms are complicated. The microbial succession study relies on macroscopic monitoring of community composition and the diversity change in each decomposition stage. With the maturity and development of high-throughput sequencing （HTS）, the structure and diversity of microbial communities in different environments have been successively revealed. A new breakthrough to explore the cadaveric microorganisms has been opened as well. It has become the research hotspots in forensic microbiology to reveal the microbial succession in the process of cadaver decomposition and to interpret the essence of various decomposition phenomena by using HTS, which can provide a new reference for postmortem interval （PMI） estimation. The present paper reviews studies on PMI estimation by using cadaveric microorganism. Problems and application prospects of forensic microbiology studies are discussed on the basis of the current application of HTS technology in the exploration of microbial succession.
Subject(s)
Humans , Autopsy , Bacteria/genetics , Cadaver , High-Throughput Nucleotide Sequencing , Postmortem ChangesABSTRACT
<p><b>OBJECTIVE</b>To construct, express and purify human fusion proteins composed of a single-chain antibody fragment scFv that recognizes the prostate specific membrane antigen (PSMA) protein, Fdt, HA2 and tp, and to analyze the binding activity of the expressed fusion proteins.</p><p><b>METHODS</b>The fusion protein genes scFv, scFv-tp, and scFv-Fdt-HA2-tp were amplified by PCR, and the genes obtained were then cloned into the expression vector pET28 and expressed in E. coli BL21. The expressed products were identified by SDS-PAGE and Western blot and purified with Ni(2+)-NTA chelating agarose. The antigen-binding activity of the fusion proteins was determined by ELISA.</p><p><b>RESULTS</b>The human anti-PSMA fusion gene was successfully constructed and expressed in M15 as the inclusion body after induced with IPTG. All the target proteins expressed could bind the PSMA antigen.</p><p><b>CONCLUSION</b>Fusion proteins can specifically bind the PSMA antigen. This finding contributes to the study of the targeted delivery of siRNA.</p>
Subject(s)
Humans , Male , Antigens, Surface , Allergy and Immunology , Cloning, Molecular , Electrophoresis, Polyacrylamide Gel , Escherichia coli , Genetics , Allergy and Immunology , Glutamate Carboxypeptidase II , Allergy and Immunology , Polymerase Chain Reaction , RNA, Small Interfering , Allergy and Immunology , Recombinant Fusion Proteins , Genetics , Allergy and Immunology , Single-Chain Antibodies , Genetics , Allergy and ImmunologyABSTRACT
<p><b>OBJECTIVE</b>To investigate the inhibitory effect of RNA interference (RNAi) on the expression of survivin mRNA and its inducibility of the apoptosis of PC-3 cells.</p><p><b>METHODS</b>siRNA expression vectors were designed and constructed to be directed at survivin and transfected into PC-3 cells by Lipofectamine in 4 groups: plasmid A, plasmid B, negative sequence and control E. RT-PCR, Western blot and flow cytometry were used to detect the expression of survivin mRNA and the apoptosis of PC-3 cells.</p><p><b>RESULTS</b>The expression rates of survivin protein were 18.94% +/- 0.63%, 16.35 +/- 0.23%, 46.41% +/- 0.76% and 46.20 +/- 1.47%, those of survivin mRNA were 27.94% +/- 1.43%, 24.51% +/- 1.37%, 49.46% +/- 0.71% and 48.49% +/- 1.32%, and the apoptosis rates of PC-3 cells were 12.80% +/- 1.33%, 16.48% +/- 1.00%, 3.03% +/- 0.62% and 2.96% +/- 0.41% respectively in different groups.</p><p><b>CONCLUSION</b>RNAi can effectively inhibit the expression of survivin mRNA and induce the apoptosis of PC-3 cells.</p>