Fetal movement during delivery can lead to damage to the umbilical vessels and endanger the life of the fetus.

INTRODUCTION: Fetal umbilical cord hematoma has a low incidence but high mortality, and its cause during delivery is often unclear. We report an autopsy case in which it was concluded that umbilical cord hematoma resulted from fetal movements during childbirth. CASE PRESENTATION AND AUTOPSY FINDINGS: A 27-year-old primigravida at 39 + 2 weeks gestation with normal antenatal visits suffered a fetal heart rate decrease during active labor. Bedside ultrasound revealed fetal death in utero 22 min later. Forensic pathologists found that the umbilical vessels were torn and bleeding on almost the same plane, and the hematoma compressed both umbilical arteries, which is the cause of fetal stillness in utero. A total of 32 cases were reported, including 6 umbilical cord ruptures and 26 umbilical cord hematomas. The cause of hematoma was unknown in 77 % of cases, while dysplasia was present in 56.25 % of umbilical cords. DISCUSSION: This case indicates that fetal movements may cause umbilical cord vessel injury, particularly when oxytocin is used to induce labor. When fetal heart sounds decrease for no apparent reason, the possibility of cord injury should be considered, and cesarean delivery should be performed as soon as possible. Therefore, rigorous fetal heart tracing during active delivery is necessary.

Analysis of road traffic accidents and casualties associated with electric bikes and bicycles in Guangzhou, China: A retrospective descriptive analysis.

Introduction: Electric bicycles (e-bikes) and bicycles in large Chinese cities have recently witnessed substantial growth in ridership. According to related accident trends, this study analyzed characteristics and spatial distribution in the period when e-bike-related accidents rapidly increased to propose priority measures to reduce accident casualties. Methods: For e-bike- and bicycle-related accident data from the Guangzhou Public Security Traffic Management Integrated System, linear regression was used to examine the trends in the number of accidents and age-adjusted road traffic casualties from 2011 to 2021. Then, for the period when e-bike-related accidents rapidly increased, descriptive statistics were computed regarding rider characteristics, illegal behaviors, road types, collision objects and their accident liability. One-way analysis of variance (ANOVA) followed by Bonferroni's multiple comparison test. P < 0.05 was considered statistically significant. Finally, the density distribution of accidents was presented, and Moran's I (MI) was used for assessing spatial autocorrelation. Hotspots were identified based on an optimized hotspot analysis tool. Results: Between 2011 and 2021, the number of accidents and casualty rate (per 100,000 population) increased for e-bikes but decreased for bicycles. After 2018, e-bike-related accidents increased rapidly, and bicycle-related accidents plateaued. Accident hotspots were concentrated in central city areas and suburban areas close to the former. Three-quarters of accidents occurred in motorized vehicle lanes. Most occurred on roads without physically segregated nonmotorized vehicle lanes. More than three-fifths of the accidents involved motor vehicles with at least four wheels. The prevalence (per 100 people) of casualties among e-bike rider victims and cyclist victims accounted for 92.0 % and 96.5 %, respectively. A total of 71.6 % of e-bike-related accidents involved migrant workers. Riding in motorized vehicle lanes was the most common illegal behavior. Conclusions: Although e-bike-related and bicycle-related accidents presented similar characteristics, the sharp increase in e-bike-related accidents requires attention. To improve e-bike safety, governments should develop appropriate countermeasures to prevent riders from riding on motorways, such as improving road infrastructure, adjusting the driver's license system and addressing priority control areas.

Two cases of driver death caused by airbag rupture.

OBJECTIVE: This article reports two accidents caused by defective Takata airbags ruptured, which led to the deaths of the drivers. This is the first public report on the deaths caused by Takata airbags in China. METHODS: Determine the relationship between the driver death and airbag rupture through autopsy indings and vehicle inspection. RESULTS: Due to defects in the design of Takata's inflator, moist air was permitted to slowly enter the inflator, resulting the PSAN slowly degraded physically. The damaged propellant burned more rapidly than intended and overpressurized the inflator's steel housing, causing fragmentation and flying debris at high speed, killing or injuring vehicle occupants. CONCLUSIONS: To date, there are still tens of millions of defective Takata airbags that have not been recalled for repair, posing safety risks. This article suggests taking preventive measures to avoid the occurrence of similar accidents.

Overview of road traffic injuries among migrant workers in Guangzhou, China, from 2017 to 2021.

INTRODUCTION: There are many migrant workers in China's first-tier cities, but little is known about road safety. This paper systematically analysed road traffic injuries and risk factors among migrant workers in Guangzhou, China. METHODS: Road traffic crash data from 2017 to 2021 were obtained from the Guangzhou Public Security Traffic Management Integrated System. We plotted the crash network of road users in road traffic crashes and used logistic regression to analyse the risk factors for migrant workers of motorcycle and four-wheeled vehicle crashes. Moreover, the roles of migrant workers and control individuals as perpetrators in road traffic crashes were also analysed. RESULTS: Between 2017 and 2021, 76% of road traffic injuries were migrant workers in Guangzhou. Migrant workers who were motorcyclist drivers most commonly experienced road traffic injuries. Crashes between motorcyclists and car occupants were the most common. The illegal behaviours of migrant worker motorcyclists were closely related to casualties, with driving without a licence only and driving without a licence and drunk driving accounting for the greatest number. Migrant workers were responsible for many injuries of other road users. Motorcycle drivers have a higher proportion of drunk driving. DISCUSSION: Migrant workers play an important role in road traffic safety. They were both the leading source of road traffic injuries and the main perpetrators of road traffic crashes. Measures such as strict requirements for migrant workers to drive motorcycles with licences, prohibit drunk driving, greater publicity of road safety regulations, and combining compulsory education with punishment for illegal behaviours.

A statistical study of postmortem heart weight in Chinese adults.

INTRODUCTION: Objective assessment of cardiac hypertrophy in forensic pathology practice is of great significance for forensic pathologists, for whom reference values for normal heart weights are needed. Developed regions such as Europe, the United States, and Japan recalculate the weight of human organs at regular intervals, but in China, there has been no systematic calculation of the weights of human organs since 2006. AIMS: To statistically analyse the heart weight of Chinese adults postmortem and obtain a reference range. MATERIALS AND METHODS: 4170 adult autopsy reports were collected from 12 forensic departments in 10 provinces in China. The causes of death were classified by sex, and heart weight and the heart weight/body height ratio reference values were further calculated according to different body mass index and body heights. Finally, the cutoff value of cardiac hypertrophy in Chinese adults was calculated. RESULTS: In the group of non-cardiovascular disease causes of death, the cardiac weight of the electric death group was higher, while the heart weight of the prolonged bed-rest group was significantly reduced. After the electric death and prolonged bed-rest groups were excluded, heart weight, the heart weight/body height ratio, and cutoff values for cardiac hypertrophy were further classified and analysed according to body mass index. The mean reference values for heart weight in men and women with normal weight status were 325.82 ± 41.60 g and 286.39 ± 44.84 g, and the heart weight/body height ratios were 1.95 ± 0.23 in men and 1.82 ± 0.27, respectively. The cutoff values for cardiac hypertrophy were 387.35 g for men and 346.80 g for women. CONCLUSION: The heart weight reference values of both sexes in this study were significantly higher than those in 2006, which is considered related to the development of China's economy and the improvement of people's living standards. This study also suggests the need for a new round of statistical surveys and updated data on the weight of other organs.

Development and Mechanical Analysis of Human Liver Model During Impact.

Liver injury is one of the most severe traffic trauma. The development of accurate liver finite element model is beneficial for improving the biofidelity and validity in crash simulations, aiming to analyze the injury in accidents. 12 human liver finite element models in the current research were constructed from high resolution CT data of a Chinese male 50th percentile human subject, including the main structures like left lobe, right lobe, capsule, parenchyma and falciform ligament. The simulations based on Nava et al. experiment were conducted to validate the models and make comparisons of modeling method accuracy. The results demonstrated that the larger deviation happened to the tetra models due to the stiffer algorithm compared to the hex models, which were more sensitive to element size. The existence of capsule had significant effects on the liver mechanical responses, reducing the liver tissue pressure. Shell elements were more suitable for modeling the capsule.

Pulmonary fat embolism: a potentially new fatal complication of SARS-CoV-2 infection. A case report.

BACKGROUND: So far, there have been more than 761 million confirmed cases of SARS-CoV-2 worldwide, with more than 6.8 million deaths. The most common direct causes of death for COVID-19 are diffuse alveolar injury and acute respiratory distress syndrome. Autopsy results have shown that 80-100% of COVID-19 patients have microthrombi which is 9 times higher than in patients with influenza. There are reported cases of fat embolism associated with Covid-19, but relevant epidemiological investigations and fatal cases of pulmonary fat embolism are lacking. In this report, we describe the first COVID-19 patient to die from pulmonary fat embolism. CASE PRESENTATION: A 54-year-old woman suddenly felt unwell while at work. She had difficulty breathing for 40 min and lost consciousness for 20 min before being taken to the hospital. On admission, her temperature was 36 ℃, but her respiration, heart rate, and blood pressure were undetectable. Laboratory examination revealed C-reactive protein, 26.55 mg/L; D-dimer, 11,400 µg/L; and procalcitonin, 0.21 ng/mL. She was declared clinically dead 2 h after admission due to ineffective rescue efforts. At autopsy, both lungs were highly oedematous with partial alveolar haemorrhage. The presence of microthrombi and pulmonary fat embolism in small interstitial pulmonary vessels was confirmed by phosphotungstic acid haematoxylin staining and oil red O staining. The immunohistochemical results of spike protein and nucleocapsid protein in laryngeal epithelial cells confirmed SARS-CoV-2 infection. CONCLUSIONS: Pulmonary fat embolism may be another fatal complication of COVID-19 infection, and clinicians should pay more attention to it.

Death from Pulmonary Embolism Caused by Vaginal Injection of Hyaluronic Acid: a Case Report and a Literature Review.

A 40-year-old woman underwent vaginoplasty with intramural injection of fillers from an illegal medical practitioner. Approximately 2 h after the injection, she developed lower abdominal pain. The patient was taken to the hospital approximately 5 h later due to worsening pain. When the patient was admitted for physical examination, she suddenly experienced cardiac and respiratory arrest. She was resuscitated but remained in a coma. Unfortunately, the patient died approximately 12 h after being admitted to the hospital. The forensic autopsy revealed extensive amorphous basophilic emboli in the small interstitial vascular lumen of both lungs, and a large amount of the same type of substances were also found in the vaginal wall. Hyaluronidase digestion and Alcian blue staining confirmed that most components of the injection were hyaluronic acid (HA). HA is widely used as a cosmetic filler in the field of plastic surgery and is generally considered to have few adverse effects. This paper reports the first anatomical case of fatal pulmonary embolism caused by vaginal injection of HA. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Characteristics of road traffic accident types and casualties in Guangzhou, China, from 2007 to 2020: A retrospective cohort study based on the general population.

Introduction: This study aimed to explore the trend and main influencing factors of road traffic accidents in Guangzhou, China, from 2007 to 2020 and to provide a reference and guidance for government decision-making. Methods: A retrospective cohort study was used to describe road traffic accidents in Guangzhou. According to the population types, all people with road traffic accidents were divided into migrant workers and the control population. We divided road users, administrative districts, motorcycle types and injury levels into subgroups to investigate the characteristics of road traffic accidents in Guangzhou. The road traffic accident data were derived from the Guangzhou Public Security Traffic Management Integrated System. Results: The incidence rate of road traffic accidents per 10,000 vehicles in Guangzhou decreased from 36.55 in 2007 to 10.07 in 2012, remained relatively stable at 9.47 in 2017, and finally rose to 11.12 in 2020. The injury rate showed the same trend as the incidence rate, while the mortality rate gradually decreased from 14.21 in 2007 to 5.19 in 2020. Vulnerable road users such as motorized two-to-three-wheeler drivers and migrant workers were casualties in more than 80% of the cases. The proportion of casualties involving mopeds and electric bicycles increased rapidly after 2018. Motor vehicle drivers frequently caused road traffic accidents and were most often uninjured. Conclusion: Road safety in Guangzhou has shown a clear trend of improvement, but casualties are uneven across administrative districts. More attention should be given to motorized two-to-three-wheelers, migrant workers, and road traffic violations by uninjured individuals.

Research Status and Prospects of Non-Traumatic Fat Embolism in Forensic Medicine.

In the practice of forensic pathology, fat embolism is one of the common causes of death, which can be divided into two categories: traumatic and non-traumatic. Non-traumatic fat embolism refers to the blockage of small blood vessels by fat droplets in the circulatory blood flow caused by non-traumatic factors such as underlying diseases, stress, poisoning and lipid metabolism disorders. At present, it is believed that the production of non-traumatic fat embolism is related to the disturbance of lipid metabolism, C-reactive protein-related cascade reaction, the agglutination of chylomicron and very low-density lipoprotein. The forensic identification of the cause of death of non-traumatic fat embolism is mainly based on the case, systematic autopsy, HE staining and fat staining, but it is often missed or misdiagnosed by forensic examiners because of its unknown risk factors, hidden onset, the difficulty of HE staining observation and irregular implementation of fat staining. In view of the lack of attention to non-traumatic fat embolism in forensic identification, this paper reviews the concepts, pathophysiological mechanism, research progress, existing problems and countermeasures of non-traumatic fat embolism, providing reference for forensic scholars.

Characteristics of human movement and injury in a side collision between the front of a small car and a bicycle.

OBJECTIVE: Our research groups have studied the movement and injury characteristics of the human body in a side collision between the front of a small car and a pedestrian. This study discusses the movement and injury characteristics of the human body in a side collision between the front of a small car and bicycle. METHODS: A total of 31 cases of traffic accidents caused by small car collisions when riding a bicycle across a road were collected. Through on-site inspection and trace inspection of the accident vehicles and bicycles, the speed of the car during the collision was calculated, the collision relationship between the small car and bicycle was determined, and the injury site and degree were determined through autopsy. The car speed was divided into two groups: <60 km/h and >60 km/h. Injuries of the skull, cervical spine, ribs, pelvis, femur and tibiofibular were analysed, and the correlations with the height of the bicycle controller, the height of the bicycle seat, the height of the car hood and the length of hood were discussed. PC-Crash was used for simulation analysis to further clarify the injury process. RESULTS: The ratio of the height of the bicycle seat to the height of the hood plus the length of the hood in the windshield-damaged group was larger than that in the undamaged windshield group (P < 0.05). No cervical fracture was found when V < 60 km/h, and 52.94% of cases had cervical fracture when V > 60 km/h. The ratio of the height of the bicycle seat to the height of the hood in the pelvic fracture group was smaller than that in the nonpelvic fracture group (P < 0.05). The incidence of tibiofibular fracture was less than 65%. CONCLUSIONS: When a side impact between a car front and a bicycle occurs, the resulting human injury is related not only to the speed but also to the height of the bicycle seat and the height and length of the hood of the car. The incidence of tibiofibular fractures was significantly lower than that of small car front-pedestrian side impacts.

Thymic hypoplasia induced by copy number variations contributed to explaining sudden infant death based on forensic autopsies.

Thymic hypoplasia is a primary cellular immunodeficiency that causes susceptibility to serious infections leading to sudden death in infants. Some genetic disorders in humans could result in the evident permanent hypoplasia or occasional aplasia of the thymus at birth. However, determining the genetic etiology of thymic hypoplasia is challenging for the sudden infant death due to primary cellular immunodeficiency. In this study, in order to find the fundamental reasons for sudden death of infants with thymic hypoplasia, 5 infants with suspected thymic hypoplasia and 10 control infants were assessed, and the immunohistochemistry and DNA analysis were used to investigate whether the infants with thymic hypoplasia had DiGeorge syndrome (DGS) with copy number variations (CNVs) in 22q11.2 and other chromosomes. The results showed that the weight of the thymus was significantly lower than the normal except the case 4, and that all the infants had hypocalcemia and a significant decrease or even absence of the markers CD1a, CD2, CD3, CD4 and CD8, which are related to T-cell maturation. In addition, multiplex ligation-dependent probe amplification (MLPA) analysis showed that these infants carried CNVs in 22q11.2 and other associated chromosomes with deletion and duplication of 25 genes. The results of thymus weight, histopathology, molecular pathology and MLPA analysis suggested that DGS predominantly with thymic hypoplasia induced by CNVs caused the sudden death of these infants under various infections or other unexplained reasons, which may provide new insights into the diagnosis of sudden infant death and could help the parents of deceased infants to attach more importance of genetic screening and thymus ultrasound to reduce the postnatal mortality of the infant, and demonstrates the value of genetic diagnosis in the forensic pathology.

Mechanism of transverse fracture of the skull base caused by blunt force to the mandible.

Transverse fracture of the skull base is common both in the crushing of temporal regions of the skull and in the case of force acting on one temporal region. However, the mechanism of transverse skull base fracture caused by maxillofacial force has not been fully clarified. To provide an injury identification basis for forensic pathologists and clinicians, this paper combines accident reconstruction and finite element analysis methods to study the injury mechanism of an incomplete transverse fracture of skull base after the injured individual's mandible was subjected to violence in a traffic accident. The results show that after the injured individual's mandible was subjected to violence, forces in the direction of the left mandibular fossa and the right mandibular fossa were generated, creating the component forces. The combination of the two forces can produce a crushing effect toward the center of the skull base, as if the left and right temporal regions are being crushed, and the stress is concentrated at the joint of the mandible, the middle cranial fossa and the hypophyseal fossa. When the stress exceeds a certain limit, it will cause a transverse fracture of the skull base.

Analysis of Pedestrian Fractures in Collisions Between Small Cars and Pedestrians Based on Surveillance Videos.

OBJECTIVE: To discuss the collision relationship and the cause of the fracture caused by traffic accidents in which the front of a small car collides with the side of a pedestrian while braking. METHODS: The surveillance videos of 42 traffic accidents involving the front of a small car colliding with the side of a pedestrian while braking were collected. By analyzing the surveillance videos and the paths, the speed of the collision, the relationship between the vehicle and the pedestrian upon collision, and the movement trajectory of the human body were clearly identified. The type and severity of the injuries were also determined through autopsy. The characteristics of the human injuries and vehicle paths were analyzed according to the collision speed (<40 km/h, 40-60 km/h, 60-90 km/h), and the correlations between the fracture and the height of the pedestrian, the height of the hood and the length of the hood were discussed. RESULTS: When a small car hits the side of a pedestrian, the front bumper first hits the lower limbs of the pedestrian, and then, the human body falls to the side of the vehicle, causing a secondary collision with the hood and front windshield; thus, the pedestrian is thrown at a speed similar to the speed of the vehicle, finally falling to the ground and sliding forward a certain distance. (1) When V is less than 40 km/h (n = 10), the pedestrian's head did not collide with the windshield, and the fatal injuries were caused by the individual striking the ground. (2) When V is greater than 40 km/h (n = 32), the majority (97%) of cases showed collision with the windshield. (3) When 40 to 60 km/h (n = 16), the pedestrian's head collided with the windshield, which can cause fatal injuries, and pelvic fractures and rib fractures occurred in 56.25% of patients. (4) When V is less than 60 km/h (n = 26), the ratio of the height of the pedestrian to the height of the hood was significantly smaller in the pelvic fracture group than in the nonpelvic fracture group (P < 0.01). (5) When 60 to 90 km/h (n = 16), there were holes in the windshield, and the pedestrians experienced severe head injuries, with cervical spine fracture occurring in 37.5% of patients, pelvic fractures occurring in 43.75% of patients, and rib fractures occurring in 31.25% of patients. CONCLUSIONS: When V is less than 40 km/h, the vehicle does not cause severe injuries in pedestrians; when V is greater than 40 km/h, the collisions of the pedestrian's head with the windshield lead to severe head injuries and the accident can cause severe pelvic and rib fractures; when V is greater than 60 km/h, the collisions of the pedestrian's head with the windshield can cause cervical spine fracture in addition to head injuries. The occurrence of human injuries is related to not only the vehicle speed but also factors such as the height of the pedestrian, the height of the hood and the length of the hood.

Antibiotics Attenuate Methamphetamine-Induced Hepatotoxicity by Regulating Oxidative Stress and TLR4/MyD88/Traf6 Axis.

Methamphetamine (METH) is a major psychostimulant drug of abuse worldwide, and its neurotoxicity has been studied extensively. In addition to neurotoxicity, METH can also induce hepatotoxicity. The underlying mechanism of intestinal microorganisms in METH-induced hepatotoxicity remains unclear. In this study, mice have received antibiotics intragastrically or PBS once each day for 1 week, followed by METH or saline. The antibiotics attenuated METH-induced hepatotoxicity as evidenced by histopathological observation and biochemical analysis; furthermore, they alleviated METH-induced oxidative stress. The effect of antibiotics on METH-induced hepatotoxicity was investigated using RNA-sequencing (RNA-seq). The RNA-seq results demonstrated that antibiotics could regulate 580 differentially expressed genes (DEGs), of which 319 were upregulated after METH treatment and then downregulated with antibiotic pretreatment and 237 were first downregulated after METH administration and then upregulated after antibiotic pretreatment, in addition to 11 upregulated and 13 downregulated ones simultaneously in METH and antibiotic-pretreated groups. RNA-seq analyses revealed that TLR4 is one of the hub genes. Western blot analysis indicated that antibiotics inhibited the increase of TLR4, MyD88 and Traf6 induced by METH. This research suggests that antibiotics may play an important role in preventing METH-induced liver injury by regulating oxidative stress and TLR4/MyD88/Traf6 axis, though further investigation is required.

Luteolin Alleviates Methamphetamine-Induced Hepatotoxicity by Suppressing the p53 Pathway-Mediated Apoptosis, Autophagy, and Inflammation in Rats.

Misuse of the psychostimulant methamphetamine (METH) could induce serious hepatotoxicity. Our previous study revealed the effects of luteolin on alleviating METH-induced hepatotoxicity, however, the detailed mechanisms have not been elucidated. In this study, rats were orally pretreated with 100 mg/kg luteolin or sodium dodecyl sulfate water, and then METH (15 mg/kg, intraperitoneal [i.p.]) or saline was administered. Histopathological and biochemical analyses were used to determine the alleviative effects of luteolin. Based on the RNA-sequencing data, METH induced 1859 differentially expressed genes (DEGs) in comparison with the control group, which were enriched into 11 signaling pathways. Among these DEGs, 497 DEGs could be regulated through luteolin treatment and enriched into 16 pathways. The p53 signaling pathway was enriched in both METH administered and luteolin pretreated rats. Meanwhile, luteolin significantly suppressed METH-induced elevation of p53, caspase9, caspase3, cleaved caspase3, the ratio of Bax/Beclin-2, as well as autophagy-related Beclin-1, Atg5, and LC3-II. Luteolin also relieved METH-induced hepatotoxicity by decreasing inflammation factors, including TNF-α, IL-1ß, and IL-18. Moreover, the levels of PI3K, p-Akt, and the normalized ratio of p-Akt/Akt declined after METH administration, whereas luteolin pretreatment failed to reverse these effects. Our results suggest that luteolin alleviates METH-induced hepatic apoptosis, autophagy, and inflammation through repressing the p53 pathway. It further illustrates the protective mechanisms of luteolin on METH-induced hepatotoxicity and provides a research basis for clinical treatment.

Sudden Death from Ischemic Heart Disease While Driving: Cardiac Pathology, Clinical Characteristics, and Countermeasures.

BACKGROUND Sudden death from ischemic heart disease while driving is an important cause of traffic accidents. This study discusses causes of traffic accidents in relation to risk factors for acute myocardial infarction such as hypertension and overwork and provides references for the early prevention and regulation of drivers' health conditions. MATERIAL AND METHODS Data on 21 cases of sudden death by ischemic heart disease while driving from January 2015 to December 2019 were collected. Age, symptoms, and cardiac pathological changes of patients were summarized by systematic anatomical and medical history data. RESULTS Patients were 21 men with an average age of 47±7.27 years (most aged 40 to 60 years), and the average weight of their hearts was 439.45±76.3 g. Twelve patients had a history of hypertension, 8 had previous myocardial infarction, and 4 had fatty liver. All had at least 1 severe narrowing of a major coronary artery. Twelve patients died within a short period; 9 died more than 12 h after myocardial infarction onset. Ten patients had worked more than 80 h of overtime per month, 4 patients, more than 45 h, and 7 patients, less than 45 h. CONCLUSIONS Regular physical examination and information about ischemic heart disease should be emphasized for men aged 40 to 60 years who drive frequently, especially for those with hypertension, overwork, or previous myocardial infarction. Incorporating objective evaluation criteria for the severity of ischemic heart disease and overwork into health condition-related driving regulations is needed.

Three Cases of Karoshi Without the Typical Pathomorphological Features of Cardiovascular/Cerebrovascular Disease.

Karoshi is a term used to describe unexplained sudden death associated with overwork and has become a serious public health issue in China. Cases have occurred in physicians, university professors, engineers in high-tech companies, and blue-collar workers. The mechanisms associated with death by overwork are very complex. According to most researchers, karoshi is considered to be caused by an excessive workload that induces deterioration of underlying hypertension or atherosclerosis. These conditions inevitably lead to death from cardiovascular or cerebrovascular diseases. However, in our own experience, we have found that in some cases, the victims of karoshi were in a chronic state of overwork but without a history of cardiovascular or cerebrovascular diseases. In support of this, we have found that even autopsies have revealed few positive findings except for cardiac hypertrophy. In this article, we report 3 typical cases of karoshi but without the typical pathomorphological features of cardiovascular or cerebrovascular disease.

Nontraumatic Multiple-Organ Fat Embolism: An Autopsy Case and Review of Literature.

The patient was an 88-year-old woman with a 10-year history of hypertension. She was suspected to have been hit by a car. At the time of the event, she was conscious and able to stand on her own and had no obvious injuries. She was sent home, but she lapsed into unconsciousness and was nonresponsive after 2 hours. She was sent to the hospital, and her heartbeat and breathing stopped. After half an hour of rescue attempts, her heartbeat did not recover, and she was declared dead. During the autopsy, a small subcutaneous hemorrhage was observed below the right knee joint. No obvious internal organ injuries or bone fractures were observed. The deceased also had mild atherosclerosis in the coronary arteries and an old cerebral infarction in the right cerebellum. The tissue histopathological tests showed distinct fat embolism in multiple organs, including the brain, lungs, kidneys, liver, and pancreas. A postmortem blood biochemistry test of the heart blood showed that the levels of low-density lipoprotein, cholesterol, triglycerides, and free fatty acids in the blood were increased, and the level of C-reactive protein was elevated. According to the autopsy results, the direct cause of death was multiorgan fat embolism. This case suggests that aging, hypertension, and hyperlipidemia may be risk factors for nontraumatic fat embolism under stressful conditions.

Karoshi May Be a Consequence of Overwork-Related Malignant Arrhythmia.

BACKGROUND Karoshi, which is sudden death associated with overwork, has become a serious problem in China. Many studies have examined the relationship between cardiovascular risks and karoshi, but there is little evidence that explains the exact mechanism by which overwork induces sudden death. In these cases, there are few obvious positive findings from forensic autopsies except for histories of overwork prior to death. Therefore, we assume that abnormalities, such as cardiac arrhythmia, rather than organic changes are the cause of karoshi. MATERIAL AND METHODS In the present study, the forced swim test (FST) was used to establish models of overwork. The myocardial tissues of SD rats taking FST (1 h per day, for 30 consecutive days) were collected. The arrhythmia-related molecule CX43 as well as its upstream regulation molecule Cav-1 and cSrc were tested by Western blot (WB) and immunohistochemistry (IHC). HE staining and Masson's staining were performed in the myocardium tissue section. RESULTS We observed downregulation of caveolin-1 (Cav1) followed by cSrc activation, resulting in the decrease of connexin43 (Cx43) levels in overwork models. Myocardial interstitial fibrosis, which is associated with electrophysiological aberrances that result in arrhythmia, was also found in the overwork models. CONCLUSIONS These data provide a mechanistic explanation for the speculated link between karoshi and cardiac arrhythmias.