Serum levels of type I interferon (IFN-I) is associated with the severity of COVID-19.

Introduction. Caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, coronavirus disease 2019 (COVID-19) has threatened global public health. Immune damage mechanisms are essential guidelines for clinical treatment and immune prevention.Hypothesis. The dysregulated type I interferon (IFN-I) responses, lymphocytopenia and hypercytokinemia during SARS-CoV-2 infection have been reported. However, whether there is a correlation between levels of IFN-I and the severity of COVID-19 has not been reported yet.Aim. To investigate the source of IFN-I and detect the exact roles of them in the pathogenesis of COVID-19.Methodology. Here ELISA was used to detect serum IFN-I (IFN-α and IFN-ß) for 137 cases with laboratory-confirmed COVID-19 admitted into one hospital in Wuhan from December 2019 to March 2020, and the relationships between IFN-α/ß concentrations and patients' clinical parameters were conducted by statistical analysis.Results. Both IFN-α and IFN-ß concentrations dramatically increased in COVID-19 patients, especially in old patients (>80 years) and severe cases. Statistical analysis demonstrated that serum IFN-α/ß concentrations were negatively correlated with the counts of total CD3+T, CD4+ and CD8+T cells, especially in critically ill cases. Moreover, serum IFN-α levels were positively correlated to IL-6 and TNF-α. Finally, immunofluorescent double staining showed that IFN-α and IFN-ß are major secretions from macrophages and dendritic cells (DCs) in lymph nodes from COVID-19 autopsies.Conclusion. These results demonstrate that macrophages and DCs are the main origination of IFN-I, and serum levels of IFN-I are positively associated with lymphopenia and cytokine storm, suggesting that IFN-α/ß deteriorated the severity of COVID-19. Anti-interferon or IFN-I signalling block drugs are needed to treat ICU patients.

Human kidney is a target for novel severe acute respiratory syndrome coronavirus 2 infection.

It is unclear whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can directly infect human kidney, thus leading to acute kidney injury (AKI). Here, we perform a retrospective analysis of clinical parameters from 85 patients with laboratory-confirmed coronavirus disease 2019 (COVID-19); moreover, kidney histopathology from six additional COVID-19 patients with post-mortem examinations was performed. We find that 27% (23/85) of patients exhibited AKI. The elderly patients and cases with comorbidities (hypertension and heart failure) are more prone to develop AKI. Haematoxylin & eosin staining shows that the kidneys from COVID-19 autopsies have moderate to severe tubular damage. In situ hybridization assays illustrate that viral RNA accumulates in tubules. Immunohistochemistry shows nucleocapsid and spike protein deposits in the tubules, and immunofluorescence double staining shows that both antigens are restricted to the angiotensin converting enzyme-II-positive tubules. SARS-CoV-2 infection triggers the expression of hypoxic damage-associated molecules, including DP2 and prostaglandin D synthase in infected tubules. Moreover, it enhances CD68+ macrophages infiltration into the tubulointerstitium, and complement C5b-9 deposition on tubules is also observed. These results suggest that SARS-CoV-2 directly infects human kidney to mediate tubular pathogenesis and AKI.

Clinicopathologic Features of COVID-19: A Case Report and Value of Forensic Autopsy in Studying SARS-CoV-2 Infection.

ABSTRACT: As of August 23, 2020, the 2019 novel coronavirus disease (COVID-19) has infected more than 23,518,340 people and caused more than 810,492 deaths worldwide including 4,717 deaths in China. We present a case of a 53-year-old woman who was admitted to the hospital because of dry coughs and high fever on January 26, 2020, in Wuhan, China. She was not tested for SARS-CoV-2 RNA until on hospital day 11 (illness day 21) because of a significant shortage of test kits at the local hospital. Then, her test was positive for COVID-19 on hospital day 20. Despite intensive medical treatments, she developed respiratory failure with secondary bacterial infection and expired on hospital day 23 (3 days after she was tested positive for SARS-CoV-2 RNA). A systemic autopsy examination, including immunohistochemistry and ultrastructural studies, demonstrates that SARS-CoV-2 can infect multiple organs with profound adverse effect on the immune system, and the lung pathology is characterized by diffuse alveolar damage. Extrapulmonary SARS-CoV-2 RNA was detected in several organs postmortem. The detailed pathological features are described. In addition, this report highlights the value of forensic autopsy in studying SARS-CoV-2 infection and the importance of clinicopathological correlation in better understanding the pathogenesis of COVID-19.

Forensic Identification of Diving Deaths. / 潜水死亡的法医学鉴定.

Investigation of the cause of death during diving is one of the contents of forensic pathology. In this article, relevant foreign literature is reviewed to summarize the techniques and methods used in the identification of diving deaths, such as accident reconstruction, diving monitoring data, postmortem CT examination and gas analysis (location and quantity) in the body of the corpse, in order to provide a reference for forensic identification of such cases.

The construction and application of a new 17-plex Y-STR system using universal fluorescent PCR.

Y-chromosomal short tandem repeat (Y-STR) polymorphisms are useful in forensic identification, population genetics, and human structures. However, the current Y-STR systems are limited in discriminating distant relatives in a family with a low discrimination power. Increasing the capacity of detecting Y chromosomal polymorphisms will drastically narrow down the matching number of genealogy populations or pedigrees. In this study, we developed a system containing 17 Y-STRs that are complementary to the current commercially available Y-STR kits. This system was constructed by multiplex PCR with expected sizes of 126-400 bp labeled by different fluorescence molecules (DYS715, DYS709, DYS716, DYS713, and DYS607 labeled by FAM; DYS718, DYS723, DYS708, and DYS714 labeled by JOE; DYS712, DYS717, DYS721, and DYS605 labeled by TAMRA; and DYS719, DYS726, DYS598, and DYS722 labeled by ROX). The system was extensively tested for sensitivity, male specificity, species specificity, mixture, population genetics, and mutation rates following the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines. The genetic data were obtained from eight populations with a total of 1260 individuals. Our results showed that all the 17 Y-STRs are human- and male-specific and include only one copy of the Y-chromosome. The 17 Y-STR system detects 143 alleles and has a high discrimination power (0.996031746). Mutation rates were different among the 17 Y-STRs, ranging from 0.30 to 3.03%. In conclusion, our study provides a robust, sensitive, and cost-effective genotyping method for human identification, which will be beneficial for narrowing the search scope when applied to genealogy searching with the Y-STR DNA databank.

Fatal Methemoglobinemia Due to Acute Inhalation of Methyl Nitrite in an Industrial Accident.

Methyl nitrite is suggested to cause methemoglobinemia by generating methemoglobin, which may be lethal when the methemoglobin concentration exceeds 70%. However, intoxication with methyl nitrite is seldom reported compared with that with other nitrites. Here, we present an industrial accident involving methyl nitrite inhalation during its synthesis process that resulted in three fatalities and one survivor. The autopsy revealed conspicuous blue-gray discoloration in various parts of the body, including the skin, airway mucosa, vessels, brain, heart, and among other areas. The toxicological tests on the deceased showed methemoglobin concentrations in the blood over the lethal level and increased nitrite ion levels in the blood, gastric contents, liver, and lung tissue compared with those in control samples. The cause of death was determined to be methemoglobinemia-induced hypoxia due to methyl nitrite inhalation. This report provides evidence that in methyl nitrite intoxication, exposure duration has a significant influence on the postmortem changes and likelihood of a fatal outcome may be related to the age of the victim. More attention is required regarding the industrial hazards of this substance.

Pathological changes in the lungs and lymphatic organs of 12 COVID-19 autopsy cases.

Systematic autopsy and comprehensive pathological analyses of COVID-19 decedents should provide insights into the disease characteristics and facilitate the development of novel therapeutics. In this study, we report the autopsy findings from the lungs and lymphatic organs of 12 COVID-19 decedents-findings that evaluated histopathological changes, immune cell signature and inflammatory factor expression in the lungs, spleen and lymph nodes. Here we show that the major pulmonary alterations included diffuse alveolar damage, interstitial fibrosis and exudative inflammation featured with extensive serous and fibrin exudates, macrophage infiltration and abundant production of inflammatory factors (IL-6, IP-10, TNFα and IL-1ß). The spleen and hilar lymph nodes contained lesions with tissue structure disruption and immune cell dysregulation, including lymphopenia and macrophage accumulation. These findings provide pathological evidence that links injuries of the lungs and lymphatic organs with the fatal systematic respiratory and immune malfunction in critically ill COVID-19 patients.

Fetal, neonatal, and infant death in central China (Hubei): A 16-year retrospective study of forensic autopsy cases.

Data based on forensic autopsy in neonates and infants in China are rare in the literature. The purpose of this study is to evaluate the characteristics of fetal, neonatal, and infant death and to determine the main cause of death among them.A retrospective analysis of fetal and infant forensic autopsies referred to the Tongji Forensic Medical Center (TFMC) in Hubei, central China, during a 16-year period between January 1999 and December 2014, was performed.In this period, there were 1111 males and 543 females; the total male-to-female ratio (MFR) was 2.05:1. There were 173 fetal and infant autopsies conducted, comprised of 43 fetal, 84 neonatal (<28 days) and 46 infant (4 weeks to 1 year) cases. The annual case number ranged from 5 in 2004 to 18 in 2014 (annual mean of 10.8). MFR was 1.75:1. About 94% of these deaths (163/173) resulted from natural causes, 6 cases (3.5%) were accidental deaths, and 4 (2.3%) resulted from homicide (4 abandoned babies). Among fetuses, the most common causes of death were placental and umbilical cord pathologies (28%, 12/43), followed by intrapartum asphyxia resulting from amniotic fluid aspiration (AFA) or meconium aspiration syndrome (MAS) (18.6%, 8/43), congenital malformation (14%, 6/43), and intrapartum infection (9.3%, 4/43). A majority of neonatal deaths (66.7%, 56/84) died within 24 hours of birth. The main causes of neonatal death were asphyxia resulting from AFA, MAS, or hyaline membrane disease, and congenital malformation. The main causes of infant (1-12 months) death were infectious diseases, including pneumonia, meningitis, and viral brainstem encephalitis.This study was the 1st retrospective analysis of autopsies of fetal, neonatal, and infant death in TFMC and central China. We delineate the common causes of early demise among cases referred for autopsy, and report a male preponderance in this population. Our data observed that placental and/or umbilical cord pathology, asphyxia due to AFA, and/or MAS, and pneumonia were the leading causes of fetal, neonatal, and infant death, respectively. And it can inform clinical practitioners about the underlying causes of some of the most distressing cases in their practices.

Lessons learned from poisoning cases caused by 2 illegal rodenticides: Tetramine and fluoroacetamide.

BACKGROUND: Tetramine (tetramethylene disulphotetramine, TETS) and fluoroacetamide (FAA) are known as illegal rodenticides with high toxicity to animal species and human beings, which could lead to severe clinical features, including reduction of consciousness, convulsions, coma, and even death. METHODS AND RESULTS: We presented 2 cases that involved rodenticides poisoning. Even though the patients showed severe manifestations, they were initially misdiagnosed, resulting in 2 persons finally died from TETS and FAA poisoning in homicide cases. CONCLUSION: From the clinical and forensic experience of these 2 cases, we suggest that physicians should consider TETS and FAA poisoning when patients present generalized seizures, especially in some cases without clear cause and diagnosis of disease. Early diagnosis and treatment are essential for positive management and criminal investigation in intentional poisoning cases. Moreover, clinical toxicology education should be reinforced.

Postmortem diagnosis of Marfan syndrome in a case of sudden death due to aortic rupture: Detection of a novel FBN1 frameshift mutation.

To investigate the sudden death of a 36-year-old Chinese man, a medicolegal autopsy was performed, combining forensic pathological examinations and genetic sequencing analysis to diagnose the cause of death. Genomic DNA samples were extracted from blood and subjected to high-throughput sequencing. Major findings included a dilated aortic root with a ruptured and dissected aorta and consequent tamponade of the pericardial sac. Moreover, arachnodactyly and other skeletal deformities were noted. By sequencing the fibrillin-1 gene (FBN1), five genetic variations were found, including four previously known single nucleotide polymorphisms (SNPs) and a novel frameshift mutation, leading to the diagnosis of Marfan syndrome. The frameshift mutation (c.4921delG, p.glu1641llysFsX9) detected in exon 40 led to a stop codon after the next 8 amino acids. The four SNPs included a splice site mutation (c.3464-5 G>A, rs11853943), a synonymous mutation (p.Asn625Asn, rs25458), and two missense mutations (p.Pro1148Ala, rs140598; p.Cys472Tyr, rs4775765). Genetic screening was recommended for the relatives as it was reported that the father and brother of the deceased had died at the ages of 40 and 25, respectively, from sudden cardiac failure. The son of the deceased lacked the relevant mutations. This report emphasizes the important contribution of medicolegal postmortem analysis on the molecular pathogenesis study of Marfan syndrome and early diagnosis of at-risk relatives.

Therapeutic effectiveness of bone marrow-derived mesenchymal stem cell administration against acute pulmonary thromboembolism in a mouse model.

INSTRUCTION: Acute pulmonary thromboembolism (APTE) is a common clinical condition associated with significant morbidity and mortality. Although promising, bone marrow-derived mesenchymal stem cell (BMSC) treatment for thrombus resolution remains controversial. The therapeutic effectiveness of BMSC against APTE has not been evaluated. This study aims to determine whether BMSCs administration is effective in mouse model. MATERIALS AND METHODS: Therapeutic efficacy of female and male BMSCs were evaluated by applying serial sectioning analysis method for the whole lungs of APTE mice and calculating each thrombus size in volume. Plasmid construction and stable transfection were used to manipulate expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in both genders of BMSCs. Western blot were performed to detect GAPDH and urokinase plasminogen activator expression in BMSCs. RESULTS: Our data showed, 1) compared with non-serial sectioning method, the serial sectioning method detected more thrombi, larger size ranges of thrombus area, and the volume of each individual thrombus. 2) BMSCs significantly decreased the thrombi size in APTE mice, with female BMSCs superior to male ones. 3) female BMSCs showed a higher GAPDH protein level and manipulations of GAPDH expression in female or male BMSCs profoundly affected their therapeutic efficacies as well as urokinase plasminogen activator expression. CONCLUSION: This study indicates serial-sectioning analysis method is necessary for evaluating APTE and provides strong evidences for BMSCs possessing therapeutic effectiveness against APTE, with female BMSCs superior to male counterparts. GAPDH played a critical role in the superior function of female BMSCs, possibly by regulating the expression of urokinase plasminogen activator.

Expression profiling of microRNAs in hippocampus of rats following traumatic brain injury.

The changes of microRNA expression in rat hippocampus after traumatic brain injury (TBI) were explored. Adult SD rats received a single controlled cortical impact injury, and the ipsilateral hippocampus was harvested for the subsequent microarray assay at three time points after TBI: 1st day, 3rd day and 5th day, respectively. We characterized the microRNA expression profile in rat hippocampus using the microRNA microarray analysis, and further verified microarray results of miR-142-3p and miR-221 using quantitative real-time PCR. Totally 205 microRNAs were identified and up-/down-regulated more than 1.5 times. There were significant changes in 17 microRNAs at all three time points post-TBI. The quantitative real-time PCR results of miR-142-3p and miR-221 indicated good consistency with the results of the microarray method. MicroRNAs altered at different time points post-TBI. MiR-142-3p and miR-221 may be used as potentially biological markers for TBI assessment in forensic practice.

Roles of 3,4-methylenedioxymethamphetamine (MDMA)-induced alteration of connexin43 and intracellular Ca(2+) oscillation in its cardiotoxicity.

UNLABELLED: Although it is well known that 3,4-methylenedioxymethamphetamine (MDMA) can cause various cardiovascular abnormalities and even sudden death from cardiac arrhythmia, whether it has any effect on myocardial gap junctions, which might be one of the targets mediating MDMA-induced cardiotoxicity, remains unclear. OBJECTIVE: To test the hypothesis that MDMA may affect the myocardial gap junction protein connexin43 (Cx43) and induce cardiac dysrhythmia. METHOD: (1) In vivo study: adult rats were treated with a single dose MDMA administration (20mg/kg, i.p.). Electrocardiogram detection and immunohistochemical analysis were performed to evaluate cardiac function and expression of Cx43, respectively; (2) in vitro study: cultured ventricular myocytes of neonatal rats were treated with MDMA (10, 100, 1000µmol/L) for 1h. Western blotting and real-time quantitative polymerase chain reaction (RT-qPCR) were performed to investigate the total Cx43 mRNA expression. Immunofluorescent analysis was used to evaluate the amount of junctional Cx43. The phosphorylation status of Cx43 at site Ser368 and intracellular Ca(2+) oscillation were also studied. RESULTS: Obvious changes in electrocardiographic patterns were found in rats following MDMA administration. They were characterized by prolonged QRS duration associated with increased amplitude of QRS complex. The heart rates in treated rats were significantly decreased compared to the rats in the control group. The immunohistochemical findings revealed a significant decrease in Cx43 expression. The in vitro study also showed a marked decline in total Cx43 protein associated with reduction of Cx43 mRNA, whereas the phosphorylated Cx43 at Ser368 was increased. Decrease of junctional Cx43 was found correlated with reduction in N-cadherin induced by high concentration of MDMA. Additionally, confocal microscopy findings revealed alteration of intracellular calcium oscillation patterns characterized by high frequency and increasing influx Ca(2+). CONCLUSIONS: MDMA reduces expression of cardiac gap junction protein Cx43. The increase of phosphorylation status of Cx43 at Ser368 induced by MDMA is attributed, at least in part, to the Ca(2+)-dependent regulation of protein kinase C (PKC) activity. Our findings provide first evidence of MDMA-mediated changes in those cardiac gap junctions that may underlie MDMA-induced cardiac arrhythmia.

Role of neuropeptide Y and peroxisome proliferator-activated receptor γ coactivator-1α in stress cardiomyopathy.

Death following situations of intense emotional stress has been linked to the cardiac pathology described as stress cardiomyopathy, whose pathomechanism is still not clear. In this study, we sought to determine, via an animal model, whether the transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α) and the amino peptide neuropeptide Y (NPY) play a role in the pathogenesis of this cardiac entity. Male Sprague-Dawley rats in the experimental group were subjected to immobilization in a plexy glass box for 1 h, which was followed by low voltage electric foot shock for about 1 h at 10 s intervals in a cage fitted with metallic rods. After 25 days the rats were sacrificed and sections of their hearts were processed. Hematoxylin-eosin staining of cardiac tissues revealed the characteristic cardiac lesions of stress cardiomyopathy such as contraction band necrosis, inflammatory cell infiltration and fibrosis. The semi-quantitative RT-PCR analysis for PGC-1α mRNA expression showed significant overexpression of PGC1-α in the stress-subjected rats (P<0.05). Fluorescence immunohistochemistry revealed a higher production of NPY in the stress-subjected rats as compared to the control rats (P=0.0027). Thus, we are led to conclude that following periods of intense stress, an increased expression of PGC1-α in the heart and an overflow of NPY may lead to stress cardiomyopathy and even death in susceptible victims. Moreover, these markers can be used to identify stress cardiomyopathy as the cause of sudden death in specific cases.

[Distribution of diatoms in central city of Beijing].

OBJECTIVE: To explore the quantity and distribution of diatoms in main rivers and lakes in Xicheng, Dongcheng, Chaoyang, Haidian, Fengtai and Shijingshan Districts of the city of Beijing. METHODS: Water samples were examined through the method of disorganizing, which were collected from 16 rivers and lakes in the central city of Beijing in September and October 2011. Diatom species and proportions of water samples were analyzed using DotSlide microscope station. RESULTS: A total of 10 species of diatoms were detected. Cyclotella, Synedra and Melosira etc. were found to be the dominant species via quantitative analysis. Significant differences were observed for diatom species and proportions among the different rivers and lakes. Melosira was found to be the dominant species in the Chang River; Synedra, in the Zhuan River, the Kunyu River and the Taoranting Park; Cyclotella, in the East Moat River, the Ba River, the Liangshui River and the Yongding River; and Navicula, in the Liangma River; Nitzschia, in the diversion canal of the Yongding River. CONCLUSION: The features of distribution of diatoms in the central city of Beijing are outlined. The morphological and relative constituent ratio database of diatoms are established in central city of Beijing.