A primary study of ethanol production in postmortem liver and muscle tissue of rats.

OBJECTIVE: To study the characteristics of postmortem ethanol production and its relation with alcohol congeners in postmortem rat liver and muscle tissues. METHOD: Postmortem liver and muscle tissues in Sprague-Dawley rats, from postmortem time interval (PMI) day 0-20, were analyzed via headspace gas chromatograph flame ionization detection to observe production of postmortem ethanol and 5 selected alcohol congeners. RESULT: 1. Putrid ethanol production increased gradually to a peak and then decreased with the prolongation of PMI; 2. Acetaldehyde, 1-propanol, and 3-methyl-butyraldehyde were produced along with postmortem ethanol; 1-butanol was only detected from day 11-20; 3. The concentrations of acetaldehyde, 1-propanol and 3-methyl-butyraldehyde was related with ethanol production. Fifteen mathematical models were constructed for putrid ethanol production based on acetaldehyde, 1-propanol, and 3-methyl-butyraldehyde. CONCLUSION: A peak in postmortem ethanol production was identified. The production trends of acetaldehyde, 1-propanol, and 3-methyl-butyraldehyde in the liver, and of 1-propanol in muscle, were consistent with those of ethanol, and could potentially to be used as biomarkers of postmortem ethanol production. Further human samples and data analysis are needed to verify this.

Neurotoxic A1 astrocytes promote neuronal ferroptosis via CXCL10/CXCR3 axis in epilepsy.

Epilepsy is a common neurological disorder with a complex etiology. Ferroptosis, a new form of programmed cell death, is characterized by the accumulation of lipid peroxides and associated with seizures. However, the underlying mechanism of ferroptosis in epilepsy remains elusive. Here, we found that GPX4-GSH-dependent neuronal ferroptosis was detected in epileptic mice, which was attenuated with ferroptosis inhibitors. Moreover, activated neurotoxic A1 astrocytes facilitated seizure-related neuronal ferroptosis in epileptic brains. Inhibition of ferroptosis blocked A1 astrocyte-induced neurotoxicity. A1 astrocyte-secreted CXCL10 enhanced STAT3 phosphorylation but suppressed SLC7A11 in neurons via CXCR3, leading to ferroptosis-associated lipid peroxidation in a GPX4-dependent manner. This was in line with clinical findings, showing a significant correlation between neuronal ferroptosis and A1 astrocytes in epileptic patients. In summary, the present data show that A1 astrocyte-induced neuronal ferroptosis contributes to the pathogenesis of epilepsy, which offers a novel therapeutic target for precision medicine.

Inhibition of Transient Receptor Potential Vanilloid 4 (TRPV4) Mitigates Seizures.

Astrocytes are critical regulators of the immune/inflammatory response in several human central nervous system (CNS) diseases. Emerging evidence suggests that dysfunctional astrocytes are crucial players in seizures. The objective of this study was to investigate the role of transient receptor potential vanilloid 4 (TRPV4) in 4-aminopyridine (4-AP)-induced seizures and the underlying mechanism. We also provide evidence for the role of Yes-associated protein (YAP) in seizures. 4-AP was administered to mice or primary cultured astrocytes. YAP-specific small interfering RNA (siRNA) was administered to primary cultured astrocytes. Mouse brain tissue and surgical specimens from epileptic patient brains were examined, and the results showed that TRPV4 was upregulated, while astrocytes were activated and polarized to the A1 phenotype. The levels of glial fibrillary acidic protein (GFAP), cytokine production, YAP, signal transducer activator of transcription 3 (STAT3), intracellular Ca2+([Ca2+]i) and the third component of complement (C3) were increased in 4-AP-induced mice and astrocytes. Perturbations in the immune microenvironment in the brain were balanced by TRPV4 inhibition or the manipulation of [Ca2+]i in astrocytes. Knocking down YAP with siRNA significantly inhibited 4-AP-induced pathological changes in astrocytes. Our study demonstrated that astrocytic TRPV4 activation promoted neuroinflammation through the TRPV4/Ca2+/YAP/STAT3 signaling pathway in mice with seizures. Astrocyte TRPV4 inhibition attenuated neuroinflammation, reduced neuronal injury, and improved neurobehavioral function. Targeting astrocytic TRPV4 activation may provide a promising therapeutic approach for managing epilepsy.

Medical Malpractice in Wuhan, China: A 10-Year Autopsy-Based Single-Center Study.

Medical disputes in China are historically poorly documented. In particular, autopsy-based evaluation and its impact on medical malpractice claims remain largely unstudied. This study aims to document autopsy findings and medical malpractice in one of the largest cities of China, Wuhan, located in Hubei Province. A total of 519 autopsies were performed by the Department of Forensic Medicine, Wuhan University School of Medicine, Wuhan, China, over a 10-year period between 2004 and 2013. Of these cases, 190 (36.6%) were associated with medical malpractice claims. Joint evaluation by forensic pathologists and clinicians confirmed that 97 (51.1%) of the 190 claims were approved medical malpractice cases. The percentage of approved malpractice cases increased with patient age and varied according to medical setting, physician specialty, and organ system. The clinico-pathological diagnostic discrepancy was significantly different among various physician specialties (P = 0.031) and organ systems (P = 0.000). Of those cases involved in malpractice claims, aortic dissection, coronary heart disease, and acute respiratory infection were most common. Association between incorrect diagnosis and malpractice was significant (P = 0.001). This is the first report on China's medical malpractice and findings at autopsy which reflects the current state of health care services in one of the biggest cities in China.

Aortic Dissection and Sudden Unexpected Deaths: A Retrospective Study of 31 Forensic Autopsy Cases.

Acute aortic dissection (AAD) is the most common cause of sudden unexpected death related to aortic diseases. A retrospective study of 31 sudden unexpected deaths caused by AAD was conducted at Xi'an Jiaotong University Forensic Center from 2001 to 2012. We summarized the forensic characteristics of AAD and assessed the clinically diagnostic accuracy of AAD. The characteristics of sudden unexpected death due to AAD were male predominant (male: female=6.7:1), relatively young with the mean age of 44, and predominance of type A dissection (77.4%). Cardiac tamponade was the most frequent cause of sudden death (87.1%). Of the 31 cases, 26 (83.9%) patients were not recognized clinically and were misdiagnosed with acute myocardial infarction, coronary artery disease, cholecystitis, acute gastroenteritis, renal/urinary lithiasis, or acute pancreatitis. In summary, AAD can be difficult to recognize, diagnosis is therefore sometimes delayed or missed. The medicolegal death investigation can help physicians have a better understanding of AAD.

A novel PCR-DGGE-based method for identifying plankton 16S rDNA for the diagnosis of drowning.

The diagnosis of drowning is one of the most difficult issues in forensic practice. We have developed a sensitive and specific PCR and DGGE method for identifying the 16S rDNA of plankton, which exists ubiquitously in all types of water. In order to evaluate the usefulness of this method for diagnosis of drowning, we used this method for detection of plankton 16S rDNA in drowned rabbits and non-drowned rabbits submerged after death, as well as two human drowning cases. Plankton DNA was identified from lung, liver, kidney, blood and brain of the drowned victims, and the DGGE patterns were helpful in indicating the site of drowning. Plankton DNA was also identified from two lung samples obtained from non-drowned rabbits. The results show that the new PCR-DGGE-based method is a potentially useful tool for diagnosing drowning.

Correlative analysis on the relationship between PMI and DNA degradation of cell nucleus in human different tissues.

To determining the postmortem interval (PMI) through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique (IAT). The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van's staining, Three indices reflecting DNA in brain cells (astrocytes) and splenic lymphocytes, including integral optical density (IOD), average optical density (AOD), average gray (AG) were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5-36 h. A correlation between the PMI and gray parameters (IOD, AOD and AG) was identified and the corresponding regression equation was obtained. The parameters (IOD, AOD and AG) were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.