Epidemiology of Sports-Related Sudden Death in Guangdong Province.

OBJECTIVES: By retrospective study of the epidemiological characteristics of sports-related sudden death (SrSD), the risk factors associated with SrSD were analyzed and explored to provide a scientific basis for comprehensive prevention and treatment of SrSD. METHODS: The personal information (sex, age, occupation, etc.), case information (time, place, type of sports, relative time between SrSD occurrence and exercise, etc.), death related information (sign or prodrome, medical history and surgical history, etc.), rescue situation (witnesses, on-site assistance, the availability of paramedics, etc.) of 374 SrSD cases in Guangdong Province from 2017 to 2021 were collected. Statistical analysis was conducted aiming at the key factors. RESULTS: In the 374 cases, there were significantly more males than females (19.78:1); the number of people aged between >39 and 59 was the largest (151, 40.37%); non-manual workers (68.98%) were more than manual workers; the top three sports with the highest number cases were basketball (34.49%), running (19.52%) and badminton (12.03%); from 3 pm to 9 pm (63.10%) was the time period with the highest incidence of events; sudden death mainly occurred during exercise (75.27%) and within 1 h after exercise (20.05%); the on-site rescue rate was very low (6.15%); the rate of autopsies was extremely low (1.07%); sudden cardiac death was the most common cause (67.11%). CONCLUSIONS: SrSD is most common in males aged >39 to 59 years old, mostly in non-manual workers, and usually occurs in basketball and running. Sudden death is more likely to occur during exercise and within 1 h after exercise. Therefore, the above potential risk factors should be focused on and studied in daily comprehensive prevention and treatment to provide scientific basis for accurate prevention and first aid of such sudden death.

Research Progress on Sport-Related Sudden Cardiac Death.

Physical exercise can reduce the overall risk of cardiovascular disease, prolong lifespan and improve the quality of life, but some studies have shown that there is a certain correlation between vigorous physical exercise and sudden cardiac death. A number of retrospective or prospective studies on sports-related sudden cardiac death (SrSCD) have been conducted at home and abroad. This article reviews the related studies on the definition, epidemiological characteristics, common causes of SrSCD and effects of excercise on cardiovascular function, pre-exercise screening and evaluation of SrSCD, in order to understand the latest research progress on SrSCD and provide clues and references for SrSCD research.

Evaluation of Inspection Efficiency of Diatom Artificial Intelligence Search System Based on Scanning Electron Microscope.

OBJECTIVES: To explore the application values of diatom artificial intelligence (AI) search system in the diagnosis of drowning. METHODS: The liver and kidney tissues of 12 drowned corpses were taken and were performed with the diatom test, the view images were obtained by scanning electron microscopy (SEM). Diatom detection and forensic expert manual identification were carried out under the thresholds of 0.5, 0.7 and 0.9 of the diatom AI search system, respectively. Diatom recall rate, precision rate and image exclusion rate were used to detect and compare the efficiency of diatom AI search system. RESULTS: There was no statistical difference between the number of diatoms detected in the target marked by the diatom AI search system and the number of diatoms identified manually (P>0.05); the recall rates of the diatom AI search system were statistically different under different thresholds (P<0.05); the precision rates of the diatom AI system were statistically different under different thresholds(P<0.05), and the highest precision rate was 53.15%; the image exclusion rates of the diatom AI search system were statistically different under different thresholds (P<0.05), and the highest image exclusion rate was 99.72%. For the same sample, the time taken by the diatom AI search system to identify diatoms was only 1/7 of that of manual identification. CONCLUSIONS: Diatom AI search system has a good application prospect in drowning cases. Its automatic diatom search ability is equal to that of experienced forensic experts, and it can greatly reduce the workload of manual observation of images.

Assisting Role of Pulmonary Hypostasis Phenomenon in Diagnosis of Drowning.

OBJECTIVES: To study the phenomenon of pulmonary hypostasis in corpses of various causes of death, and to explore the potential value of this phenomenon in assisting forensic pathological diagnosis of drowning. METHODS: A total of 235 cases with clear cause of death through systematic autopsy were collected from January 2011 to June 2021 in Guangzhou. According to the location of body discovery, the cases were divided into the water body group (97 cases) and the non-water body group (138 cases), and the water body group was further divided into the water drowning group (90 cases) and the water non-drowning group (7 cases). Non-water body group was further divided into the non-water drowning group (1 case) and the non-water non-drowning group (137 cases). Three senior forensic pathologists independently reviewed autopsy photos to determine whether there was hypostasis in the lungs. The detection rate of pulmonary hypostasis was calculated. RESULTS: The detection rate of pulmonary hypostasis in the water drowning group (90 cases) was 0, and the negative rate was 100%. The detection rate of pulmonary hypostasis in the water non-drowning group (7 cases) was 100% and the negative rate was 0. The detection rate of pulmonary hypostasis in the water body group and in the non-water body group (after excluding 2 cases, 136 cases were calculated) was 7.22% and 87.50%, respectively. There were statistically significant differences in the detection rate of pulmonary hypostasis between water body group and non-water body group, and between water drowning group and water non-drowning group (P<0.05). CONCLUSIONS: The disappearance of pulmonary hypostasis can be used as a specific cadaveric sign to assist in the forensic pathological diagnosis of drowning.

Review and Thinking on Forensic Pathological Changes of Coronavirus-Infected Diseases.

Since the beginning of this century, three types of coronavirus have widely transmitted and caused severe diseases and deaths, which strongly indicates that severe infectious diseases caused by coronavirus infection are not accidental events. Coronavirus-infected diseases are mainly manifested by respiratory symptoms, with multiple organ dysfunctions. Precisely investigating the pathological process, characteristics and pathogenesis of coronavirus-infected diseases will be beneficial for us to understand clinical manifestations and provide targeted suggestions on prophylaxis and treatment. This paper briefly reviews the pathological findings of three known coronavirus-infected diseases, and attempts to construct the pathological spectrum of coronavirus-infected diseases, aiming to provide reference and thinking for autopsy, histopathological examination and animal infection model study of coronavirus-infected diseases.

LNK deficiency aggravates palmitate-induced preadipocyte apoptosis.

LNK (SH2B3) is an intracellular adaptor protein that negatively regulates cellular proliferation or self-renewal of hematopoietic stem cells and some other progenitor cells. LNK is also recognized as a key regulator of insulin resistance and inflammatory responses in several tissues and organs. The function of LNK in adipose tissue is unknown. We previously demonstrated that type 2 diabetes mellitus (T2DM) mouse model had elevated serum free fatty acids (FFAs) levels and increased preadipocyte apoptosis in visceral fat tissue, showing the occurrence of lipotoxicity. Herein, when compared to control mice, the protein expression of LNK decreased in epididymal fat tissue from the high-sucrose/fat diet, low-dose streptozotocin induced T2DM mouse model. We thus investigated whether LNK could regulate palmitate-induced preadipocyte apoptosis in an in vitro apoptotic model in 3T3-L1 preadipocytes. LNK specific siRNA exacerbated palmitate-induced apoptosis and increased pro-apoptotic protein levels of cleaved caspase-3, Bax and cytochrome C; while overexpression of LNK cDNA exhibited significant anti-apoptotic effects. Consistently, LNK specific siRNA further decreased the Akt Ser-473 phosphorylation reduced by palmitate and located on upstream of Bax and cytochrome C. The siRNA-mediated LNK knockdown exacerbated mitochondrial membrane depolarization and mitochondrial-derived reactive oxygen species production induced by palmitate, whereas overexpression of LNK attenuated that. These results indicated that LNK plays a regulatory role in the palmitate-related preadipocyte apoptosis and might be involved in adipose tissue dysfunction.

A novel mutation in the STK11 gene causes heritable Peutz-Jeghers syndrome - a case report.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disorder characterized by multiple gastrointestinal hamartomatous polyps and mucocutaneous pigmentation. STK11 has been identified as a causative gene for this disease. CASE PRESENTATION: Herein we report a Chinese Han kindred with PJS. Onset for the PJS signs in three of the patients was rarely as early as at birth. We identified a novel heterozygous mutation (c.440_441delGT, p.Arg147Leufs*15) in the gene STK11, causing a short frameshift followed by a deletion of 63% of the amino acids in the STK protein. This mutation co-segregated with the PJS phenotype, and was absent in two hundred of unrelated ethnicity-matched controls. The mutation led to expression decrease of unaffected STK11 protein in patients than in controls, as well in PJ polyps than in circulating leucocytes from the patients. Phosphorylation levels of the downstream kinase AMPKα altered according with the expression of STK11. These results indicated the possibility that haploinsufficiency and epigenetic reduction of STK11 contributed to the pathogenesis of the disease. CONCLUSION: This study identifies a novel mutation in the pathogenic gene STK11 leading to PJS.

Xyloketal B alleviates cerebral infarction and neurologic deficits in a mouse stroke model by suppressing the ROS/TLR4/NF-κB inflammatory signaling pathway.

Xyloketal B (Xyl-B) is a novel marine compound isolated from mangrove fungus Xylaria sp. We previously demonstrated that pretreatment with Xyl-B exerted neuroprotective effects and attenuated hypoxic-ischemic brain injury in neonatal mice. In the present study we investigated the neuroprotective effects of pre- and post-treatment with Xyl-B in adult mice using a transient middle cerebral artery occlusion (tMCAO) model, and explored the underlying mechanisms. Adult male C57 mice were subjected to tMCAO surgery. For the pre-treatment, Xyl-B was given via multiple injections (12.5, 25, and 50 mg·kg-1·d-1, ip) 48 h, 24 h and 30 min before ischemia. For the post-treatment, a single dose of Xyl-B (50 mg/kg, ip) was injected at 0, 1 or 2 h after the onset of ischemia. The regional cerebral perfusion was monitored using a laser-Doppler flowmeter. TTC staining was performed to determine the brain infarction volume. We found that both pre-treatment with Xyl-B (50 mg/kg) and post-treatment with Xyl-B (50 mg/kg) significantly reduced the infarct volume, but had no significant hemodynamic effects. Treatment with Xyl-B also significantly alleviated the neurological deficits in tMCAO mice. Furthermore, treatment with Xyl-B significantly attenuated ROS overproduction in brain tissues; increased the MnSOD protein levels, suppressed TLR4, NF-κB and iNOS protein levels; and downregulated the mRNA levels of proinflammatory cytokines, including IL-1ß, TNF-α, IL-6 and IFN-γ. Moreover, Xyl-B also protected blood-brain barrier integrity in tMCAO mice. In conclusion, Xyl-B administered within 2 h after the onset of stroke effectively protects against focal cerebral ischemia; the underlying mechanism may be related to suppressing the ROS/TLR4/NF-κB inflammatory signaling pathway.

Investigation of associations between ten polymorphisms and the risk of coronary artery disease in Southern Han Chinese.

A large-scale meta-analysis of 14 genome-wide association studies has identified and replicated a series of susceptibility polymorphisms for coronary artery disease (CAD) in European ancestry populations, but evidences for the associations of these loci with CAD in other ethnicities remain lacking. Herein we investigated the associations between ten (rs579459, rs12413409, rs964184, rs4773144, rs2895811, rs3825807, rs216172, rs12936587, rs46522 and rs3798220) of these loci and CAD in Southern Han Chinese (CHS). Genotyping was performed in 1716 CAD patients and 1572 controls using mass spectrography. Both allelic and genotypic associations of rs964184, rs2895811 and rs3798220 with CAD were significant, regardless of adjustment for covariates of gender, age, hypertension, type 2 diabetes, blood lipid profiles and smoking. Significant association of rs12413409 was initially not observed, but after the adjustment for the covariates, both allelic and genotypic associations were identified as significant. Neither allelic nor genotypic association of the other six polymorphisms with CAD was significant regardless of the adjustment. Our results indicated that four loci of the total 10 were associated with CAD in CHS. Therefore, some of the CAD-related loci in European ancestry populations are indeed susceptibility loci for the risk of CAD in Han Chinese.

[Simulation and Observation of Vertical Cast-off Bloodstain Pattern].

OBJECTIVE: To observe the characteristics of vertical cast-off bloodstain pattern by different hitting-tools. METHODS: The regular hitting tools, a kitchen knife, a dirk, a plane set-hammer and an iron pipe, were selected. At a distance of 30 cm away from the wall, the hitting tool with 5 mL fresh chicken blood made the cast-off bloodstain from top to bottom. Then the holistic distribution characteristics (length, width and density) of cast-off bloodstain and morphology characteristics (length, width and contact angle) of first single cast-off bloodstain were analyzed. RESULTS: The distribution length of cast-off bloodstain formed by dirk was minimum (P < 0.05). The distribution width of cast-off bloodstain formed by kitchen knife was minimum (P < 0.05). Except the pair of kitchen knife and plane set-hammer, the distribution density between each two tools had statistical differences (P < 0.05). The length of first single cast-off bloodstain formed by plane set-hammer was longest compared (P < 0.05). The width of first single cast-off bloodstain had statistical differences between kitchen knife and plane set-hammer, and between dirk and plane set-hammer (P < 0.05). CONCLUSION: The type of hitting tool could be inferred by the specific characteristics of cast-off bloodstain pattern formed by every specific type of hitting tool in crime scene.

EEN regulates the proliferation and survival of multiple myeloma cells by potentiating IGF-1 secretion.

The molecular mechanisms of multiple myeloma are not well defined. EEN is an endocytosis-regulating molecule. Here we report that EEN regulates the proliferation and survival of multiple myeloma cells, by regulating IGF-1 secretion. In the present study, we observed that EEN expression paralleled with cell proliferation, EEN accelerated cell proliferation, facilitated cell cycle transition from G1 to S phase by regulating cyclin-dependent kinases (CDKs) pathway, and delayed cell apoptosis via Bcl2/Bax-mitochondrial pathway. Mechanistically, we found that EEN was indispensable for insulin-like growth factor-1 (IGF-1) secretion and the activation of protein kinase B-mammalian target of rapamycin (Akt-mTOR) pathway. Exogenous IGF-1 overcame the phenotype of EEN depletion, while IGF-1 neutralization overcame that of EEN over-expression. Collectively, these data suggest that EEN may play a pivotal role in excessive cell proliferation and insufficient cell apoptosis of bone marrow plasma cells in multiple myeloma. Therefore, EEN may represent a potential diagnostic marker or therapeutic target for multiple myeloma.

Recombination analysis of autosomal short tandem repeats in Chinese Han families.

Recombination fractions between forensic STRs can be extrapolated from the International HapMap Project, but the concordance between recombination fractions predicated from genetic maps and derived from observation of STR transmissions in families is still ambiguous for autosomal STRs because of limited family studies. Therefore, the main goal of this study is to compare recombination fractions estimated by pedigree analysis with those derived from HapMap phase SNP data. Genotypes of nine autosomal STR pairs (TPOX-D2S1772, D5S818-CSF1PO, D7S3048-D7S820, D8S1132-D8S1179, TH01-D11S2368, vWA-D12S391, D13S325-D13S317, D18S51-D18S1364, and D21S11-PentaD) from 207 two-generation families with two to five children (the number of families with five, four, three, and two children was 2, 3, 20, and 182, respectively) were used to analyze the recombination. The linkage analysis showed that significant linkage was observed at six STR pairs (D5S818-CSF1PO, D8S1132-D8S1179, TH01-D11S2368, vWA-D12S391, D13S325-D13S317, and D18S51-D18S1364) with genetic distances <36.22 cM in HapMap. Their recombination fractions calculated from family data were very close to those derived from HapMap. However, three STR pairs of TPOX-D2S1772, D7S3048-D7S820, and D21S11-PentaD showed no significant linkage with genetic distances from 43.38 to 91.49 cM. Our results indicate that recombination fractions extrapolated from HapMap can provide a substitute if empirical data are unavailable for the linkage STR pair with a genetic distance spanned <36.22 cM.

[Death caused by anaphylactic shock: a forensic pathological analysis of 142 cases].

OBJECTIVE: To explore the forensic pathological features of death caused by anaphylactic shock. METHODS: One hundred and forty-two death cases of anaphylactic shock were retrospectively analyzed. The IgE level in the serum of anaphylactic shock cases were statistically compared with that of 62 non-anaphylactic shock cases. RESULTS: Most cases (77.46%) of anaphylactic shock death occurred in the medical institutes, with intravenous drug administration accounting for 53.53% of anaphylactic shock death. ß-Lactam antibiotics, glucocorticoid and herbal medications were responsible for a significant proportion of such cases. Although characteristic histopathological changes were absent in vast majority of these anaphylactic shock cases, the differences of IgE levels in the serum between anaphylactic shock group and non-anaphylactic shock group were statistically significant (P<0.05). CONCLUSION: Combined information including clinical data, autopsy results, IgE level, and other specific test results should be evaluated together in the forensic pathological diagnosis of anaphylactic shock.

[Diatoms in drowned and postmortem immersed rabbits' lungs].

OBJECTIVE: To investigate the numbers, sizes and types distribution of diatoms in drowned and postmortem immersed rabbits' lungs. METHODS: Sixty-two rabbits were randomly divided into drowning group (n = 30), postmortem immersion group (n = 30) and land death group (n=2), and the diatoms in each lung lobe were analyzed quantitatively and qualitatively by microwave digestion and scanning electron microscopy. RESULTS: In the drowning group, the diatoms were detected in each lung lobe with Cyclotella and Melosira in the majority. In the postmortem immersion group, Cyclotella was in the majority. And the diatoms weren't detected in some lung lobes in postmortem immersion. There were significant differences in the detection rates of upper lobe of left lung, middle lobe and cardiac lobe of right lung in two groups (P < 0.05). CONCLUSION: Based on the microwave digestion and scanning electron microscopy, the numbers, sizes and types distribution of diatoms in drowned and postmortem immersed rabbits' lungs can be analyzed and used as references for testing theory.

[Epidemiological characters of Yunnan sudden death syndrome and its research progress].

Yunnan sudden death syndrome (YSDS) is an abruptly fatal disease of unknown etiology, found mostly in central or northwestern mountain area (with altitude between 1,815 and 2,225 meters) of Yunnan province from June to September every year. It occurs mostly in young female adults, with high incidences in Lisu, Yi and Miao ethnics and high familial aggregation. The clinical manifestation of YSDS is changeful and the pathological characteristic is lack of specificity. The pathogenesis may be attributed to several factors including poor hygiene and lower socioeconomic conditions, lack of Selenium or Chromium, infection of Coxsackie B virus, mushroom consumption and special geological conditions. This article reviews the epidemiologic features, clinical manifestations, pathological features, etiology and hypothesis in order to provide clues for the research of YSDS.

[Gene detection of GPD1-L and the association with sudden unexplained death syndrome in young adults].

OBJECTIVE: To analyze the variations of glycerol-3-phosphate dehydrogenase 1 like gene (GPD1-L) and address the association with sudden manhood death syndrome (SMDS). METHODS: The genomic DNA was extracted from blood samples of the SMDS group and the normal control group. The exons, exon-intron boundaries and 3'-UTRs of coding region of GPD1-L were PCR amplified and DNA sequenced directly to confirm the types of variations. The genotype frequency and allele frequency were analyzed statistically. RESULTS: There were two variants in the SMDS group, c.465C>T and c.*18G>T, the latter existed certain degree difference of genotype distribution and allele frequency between the SMDS group and the control group, but there was no statistically significant (P > 0.05). CONCLUSION: The relation between gene mutation of GPD1-L and the occurrence of Chinese SMDS deserves a further research.

[Sudden death caused by aortic dissection: 63 cases of forensic pathological analysis].

OBJECTIVE: To explore the cause of death, clinical manifestations and forensic pathological features of death cases caused by aortic dissection. METHODS: Sixty-three cases of aortic dissection were selected from forensic medical center, Sun Yat-sen University from 2001 to 2011 and retrospectively analyzed. RESULTS: The patients were mostly young and middle-aged male, aged from 30 to 49 years old. The DeBakey type II was the most common pathological type and the main cause of death was pericardial tamponade. The most common symptom was abdominal pain. However, the location of aorta dissection did not always correlate with the location of pain. Some cases showed no obvious clinical symptoms. The rupture was usually located in ascending aorta with atherosclerosis and pathological changes of hypertension. CONCLUSION: It is significant for diagnosis and evaluation the cause of death of aortic dissection by knowing the clinical symptoms and forensic pathological features.

[KCNQ1, KCNH2, KCNE1 and KCNE2 potassium channels gene variants in sudden manhood death syndrome].

OBJECTIVE: To investigate KCNQ1, KCNH2, KCNE1 and KCNE2 gene variants in the cases of sudden manhood death syndrome (SMDS). METHODS: One hundred and sixteen sporadic cases of SMDS and one hundred and twenty-five healthy controlled samples were enrolled. Genomic DNA was extracted from blood samples. Gene variants of KCNQ1, KCNH2, KCNE1 and KCNE2 were screened by direct sequencing. RESULTS: A total of 14 mutations and 14 SNP were detected. Two non-synonymous mutations of them were newfound. There was no non-synonymous mutation found in the control group. CONCLUSION: There are KCNQ1, KCNH2, KCNE1 and KCNE2 gene variants found in Chinese SMDS cases. KCNQ1, KCNH2, KCNE1 and KCNE2 gene mutation may correlate partly with the occurrence of some cases of the SMDS in China.

[Genetic polymorphisms of 9 non-combined of DNA index system short tandem repeat loci in Guangdong Han population].

OBJECTIVE: To investigate the genetic polymorphisms and their forensic application of 9 non-combined of DNA index system (CODIS) short tandem repeat(STR) loci in Guangdong Han population. METHODS: DNA samples from 500 unrelated individuals were extracted and amplified with fluorescence labeled multiplex PCR system. PCR products were separated and genotyped with capillary electrophoresis. RESULTS: One hundred and fifteen alleles and 160 genotypes were observed in the 9 STR loci, respectively. The heterozygosity was 0.824-0.884, the discrimination power (DP) was 0.925-0.969 and the polymorphism information content (PIC) was 0.77-0.86, respectively. The distribution met the Hardy-Weinberg equilibrium (P > 0.05). The total discrimination power was 1.00 x 10(-13), the combined probability of exclusion for trio-paternity testing was 0.999989488. The combined probability of exclusion for duo-paternity testing was 0.873436. CONCLUSION: The 9 STR loci are powerful and reliable for personal identification and paternity testing. They can be used as supplementary loci in fatherless (motherless) testing or cases with mutation events.

Screening and identification of differentially expressed genes in myocardial ischaemia/reperfusion injury using suppression subtractive hybridization.

OBJECTIVE: Myocardial ischaemia/reperfusion (MI/R) injury is characterized by metabolic and ultrastructural changes, which lead to irreversible injury. Several mechanisms have been postulated for the pathogenesis of MI/R injury although little is known regarding the role of myocardial gene expression. METHODS AND RESULTS: In this study, suppression subtractive hybridization (SSH) was employed to systematically isolate and screen the differentially expressed genes in the MI/R injury rat model. The characteristics of these specific genes were analysed using bioinformatics. Our results showed that among the 119 identified genes, 54 genes were expressed at higher levels and 65 genes were at lower levels compared with the control group. CONCLUSIONS: These genes are closely associated with energy metabolism, iron transport, signalling transduction and may provide important clues for the elucidation of the mechanisms of MI/R injury. Our results further indicated that myocardial injury is likely the result of summation of functional impairment of multiple genes rather than the result of damage to a single critical gene.