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Journal of the American Association For... Mar 2024Despite the major use of mice in biomedical research, little information is available with regard to identifying their postmortem changes and using that information to...
Despite the major use of mice in biomedical research, little information is available with regard to identifying their postmortem changes and using that information to determine the postmortem interval (PMI), defined as the time after death. Both PMI and environmental conditions influence decomposition (autolysis and putrefaction) and other postmortem changes. Severe decomposition compromises lesion interpretation and disease detection and wastes limited pathology resources. The goal of this study was to assess postmortem changes in mice in room temperature cage conditions and under refrigeration at 4 °C to develop gross criteria for the potential value of further gross and histologic evaluation. We used 108 experimentally naïve C57BL/6 mice that were humanely euthanized and then allocated them into 2 experimental groups for evaluation of postmortem change: room temperature (20 to 22 °C) or refrigeration (4 °C). PMI assessments, including gross changes and histologic scoring, were performed at hours 0, 4, 8, and 12 and on days 1 to 14. Factors such as temperature, humidity, ammonia in the cage, and weight change were also documented. Our data indicates that carcasses held at room temperature decomposed faster than refrigerated carcasses. For most tissues, decomposition was evident by 12 h at room temperature as compared with 5 d under refrigeration. At room temperature, gross changes were present by day 2 as compared with day 7 under refrigeration. Mice at room temperature lost 0.78% of their baseline body weight per day as compared with 0.06% for refrigerated mice (95% CI for difference 0.67% to 0.76%, < 0.0005). This study supports the consideration of temperature and PMI as important factors affecting the suitability of postmortem tissues for gross and histologic evaluation and indicates that storage of carcasses under refrigeration will significantly slow autolysis.
PubMed: 38471755
DOI: 10.30802/AALAS-JAALAS-23-000107 -
Journal of Leukocyte Biology Jan 2017Antibiotics have proven to be enormously effective tools in combating infectious diseases. A common roadblock to the effective use of antibiotics is the development of... (Review)
Review
Antibiotics have proven to be enormously effective tools in combating infectious diseases. A common roadblock to the effective use of antibiotics is the development of antibiotic resistance. We have recently observed that the very mechanism by which methicillin-resistant Staphylococcus aureus (MRSA) becomes antibiotic resistant causes the organism to be more inflammatory to innate immune cells. In this review, we offer some thoughts on the ways in which antibiotics have been observed to influence immune responses to bacteria.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Cell Wall; Humans; Inflammation; Microbial Sensitivity Tests; Microbial Viability
PubMed: 27576461
DOI: 10.1189/jlb.4MR0316-153RR -
Frontiers in Microbiology 2016Death is a universal phenomenon; however, is there "life after death?" This topic has been investigated for centuries but still there are gray areas that have yet to be... (Review)
Review
Death is a universal phenomenon; however, is there "life after death?" This topic has been investigated for centuries but still there are gray areas that have yet to be elucidated. Forensic microbiologists are developing new applications to investigate the dynamic and coordinated changes in microbial activity that occur when a human host dies. There is currently a paucity of explorations of the thanatomicrobiome (thanatos-, Greek for death) and epinecrotic communities (microbial communities residing in and/or moving on the surface of decomposing remains). Ongoing studies can help clarify the structure and function of these postmortem microbiomes. Human microbiome studies have revealed that 75-90% of cells in the body prior to death are microbial. Upon death, putrefaction occurs and is a complicated process encompassing chemical degradation and autolysis of cells. Decomposition also involves the release of contents of the intestines due to enzymes under the effects of abiotic and biotic factors. These factors likely have predictable effects on postmortem microbial communities and can be leveraged for forensic studies. This mini review provides a critical examination of emerging research relating to thanatomicrobiome and epinecrotic communities, how each is studied, and possible strategies of stochastic processes.
PubMed: 26941736
DOI: 10.3389/fmicb.2016.00225 -
Future Microbiology Mar 2023is one of the major cariogenic pathogens in the oral cavity. The operon is responsible for the process of D-alanylation of lipoteichoic acid and is related to the... (Review)
Review
is one of the major cariogenic pathogens in the oral cavity. The operon is responsible for the process of D-alanylation of lipoteichoic acid and is related to the virulence of . The operon contributes to the adhesion, biofilm formation, stress response, interspecies competitiveness and autolysis of . In addition, we have summarized the possible regulatory networks of the operon. This review highlights the significant role of the operon in and provides new ideas for ecological caries prevention.
Topics: Humans; Streptococcus mutans; Virulence; Biofilms; Mouth; Operon; Dental Caries
PubMed: 37097048
DOI: 10.2217/fmb-2022-0165 -
Nature Communications Feb 2024Mechanical force contributes to perforin pore formation at immune synapses, thus facilitating the cytotoxic T lymphocytes (CTL)-mediated killing of tumor cells in a...
Mechanical force contributes to perforin pore formation at immune synapses, thus facilitating the cytotoxic T lymphocytes (CTL)-mediated killing of tumor cells in a unidirectional fashion. How such mechanical cues affect CTL evasion of perforin-mediated autolysis remains unclear. Here we show that activated CTLs use their softness to evade perforin-mediated autolysis, which, however, is shared by T leukemic cells to evade CTL killing. Downregulation of filamin A is identified to induce softness via ZAP70-mediated YAP Y357 phosphorylation and activation. Despite the requirements of YAP in both cell types for softness induction, CTLs are more resistant to YAP inhibitors than malignant T cells, potentially due to the higher expression of the drug-resistant transporter, MDR1, in CTLs. As a result, moderate inhibition of YAP stiffens malignant T cells but spares CTLs, thus allowing CTLs to cytolyze malignant cells without autolysis. Our findings thus hint a mechanical force-based immunotherapeutic strategy against T cell leukemia.
Topics: T-Lymphocytes, Cytotoxic; Perforin; Pore Forming Cytotoxic Proteins; Cytotoxicity, Immunologic
PubMed: 38360940
DOI: 10.1038/s41467-024-45750-w -
The Veterinary Clinics of North... Apr 2018Because most poisonings occur by toxin ingestion, the gastrointestinal system is the first exposed and, in most cases, it is exposed to the highest toxin concentrations.... (Review)
Review
Because most poisonings occur by toxin ingestion, the gastrointestinal system is the first exposed and, in most cases, it is exposed to the highest toxin concentrations. Consequently, enterocyte damage is common. However, because many toxins produce organ-specific damage, and enterocyte necrosis is easily confused with autolysis, many gastrointestinal lesions are overlooked or overshadowed by other clinical and pathologic changes. The objective of this work is to review several common toxins and poisonous plants that produce primarily gastrointestinal disease.
Topics: Animals; Gastrointestinal Diseases; Horse Diseases; Horses; Microcystins; Plants, Toxic
PubMed: 29397222
DOI: 10.1016/j.cveq.2017.11.008 -
Protoplasma Jul 2023Chitin, the world's second most abundant biopolymer after cellulose, is composed of β-1,4-N-acetylglucosamine (GlcNAc) residues. It is the key structural component of... (Review)
Review
Chitin, the world's second most abundant biopolymer after cellulose, is composed of β-1,4-N-acetylglucosamine (GlcNAc) residues. It is the key structural component of many organisms, including crustaceans, mollusks, marine invertebrates, algae, fungi, insects, and nematodes. There has been a significant increase in the generation of chitinous waste from seafood businesses, resulting in a big amount of scrap. Although several organisms, such as plants, crustaceans, insects, nematodes, and animals, produce chitinases, microorganisms are promising candidates and a sustainable option that mediates chitin degradation. Fungi are the dominant group of chitinase producers among microorganisms. In fungi, chitinases are involved in morphogenesis, cell division, autolysis, chitin acquisition for nutritional purposes, and mycoparasitism. Many efficient chitinolytic fungi with potential applications have been identified in a variety of environments, including soil, water, marine wastes, and plants. The current review highlights the key sources of chitinolytic fungi and the characterization of fungal chitinases. It also discusses the applications of fungal chitinases and the cloning of fungal chitinase genes.
Topics: Animals; Chitinases; Chitin
PubMed: 36752884
DOI: 10.1007/s00709-023-01839-5 -
Nature Communications Jul 2023Proteins with a catalytically inactive LytM-type endopeptidase domain are important regulators of cell wall-degrading enzymes in bacteria. Here, we study their...
Proteins with a catalytically inactive LytM-type endopeptidase domain are important regulators of cell wall-degrading enzymes in bacteria. Here, we study their representative DipM, a factor promoting cell division in Caulobacter crescentus. We show that the LytM domain of DipM interacts with multiple autolysins, including the soluble lytic transglycosylases SdpA and SdpB, the amidase AmiC and the putative carboxypeptidase CrbA, and stimulates the activities of SdpA and AmiC. Its crystal structure reveals a conserved groove, which is predicted to represent the docking site for autolysins by modeling studies. Mutations in this groove indeed abolish the function of DipM in vivo and its interaction with AmiC and SdpA in vitro. Notably, DipM and its targets SdpA and SdpB stimulate each other's recruitment to midcell, establishing a self-reinforcing cycle that gradually increases autolytic activity as cytokinesis progresses. DipM thus coordinates different peptidoglycan-remodeling pathways to ensure proper cell constriction and daughter cell separation.
Topics: Humans; N-Acetylmuramoyl-L-alanine Amidase; Caulobacter crescentus; Feedback; Constriction; Autolysis
PubMed: 37433794
DOI: 10.1038/s41467-023-39783-w -
Journal of Oral and Maxillofacial... 2023According to Codex Alimentarius, 'Honey is the natural sweet substance, produced by honeybees from the nectar of plants or from secretions of living parts of plants, or... (Review)
Review
According to Codex Alimentarius, 'Honey is the natural sweet substance, produced by honeybees from the nectar of plants or from secretions of living parts of plants, or excretions of plant-sucking insects on the living parts of plants, which the bees collect, transform by combining with specific substances of their own, deposit, dehydrate, store and leave in honeycombs to ripen and mature'. It can also penetrate deep into the tissue and can prevent autolysis and putrefaction. This paper highlights the usefulness of honey as an embalming agent.
PubMed: 38033935
DOI: 10.4103/jomfp.jomfp_42_23 -
Journal of Veterinary Diagnostic... Sep 2021Estimation of the postmortem interval (PMI) is a poorly studied field in veterinary pathology. The development of field-applicable methods is needed given that animal...
Estimation of the postmortem interval (PMI) is a poorly studied field in veterinary pathology. The development of field-applicable methods is needed given that animal cruelty investigations are increasing continually. We evaluated various histologic criteria in equine brain, liver, and muscle tissue to aid the estimation of PMI in horses, which is central to forensic investigations of suspicious death. After death, autolysis proceeds predictably, depending on environmental conditions. Currently, no field-applied methods exist that accurately estimate the PMI using histology in animals or humans through quantification of autolysis. Brain, liver, and skeletal muscle from 12 freshly euthanized horses were held at 22°C and 8°C for 72 h. Tissues were sampled at T0h, T1h, T2h, T4h, T6h, T12h, T24h, T36h, T48h, T60h, and T72h. For each tissue, we quantified 5 to 7 criteria associated with autolysis, based on the percentage of microscopic field involved. Each criterion was modeled, with temperature and time as independent variables. Changes were most predictable in liver and muscle over the first 72 h postmortem. The criteria for autolysis that were present most extensively at both temperatures were hepatocyte individualization and the separation of bile duct epithelium from the basement membrane. The changes that were present next most extensively were disruption of myofiber continuity, hypereosinophilia, and loss of striation. Brain changes were highly variable. The high statistical correlation between the parameter "autolysis" and the variables "time/temperature", indicates that autolysis is progressive and predictable. Further investigation of these criteria is needed to establish histologic algorithms for PMI.
Topics: Animals; Autopsy; Feasibility Studies; Forensic Pathology; Horse Diseases; Horses; Muscle, Skeletal; Postmortem Changes
PubMed: 34109897
DOI: 10.1177/10406387211021865