Detection of multiple biomarkers associated with satellite cell fate in the contused skeletal muscle of rats for wound age estimation.

From the perspective of forensic wound age estimation, experiments related to skeletal muscle regeneration after injury have rarely been reported. Here, we examined the time-dependent expression patterns of multiple biomarkers associated with satellite cell fate, including the transcription factor paired box 7 (Pax7), myoblast determination protein (MyoD), myogenin, and insulin-like growth factor (IGF-1), using immunohistochemistry, western blotting, and quantitative real-time PCR in contused skeletal muscle. An animal model of skeletal muscle contusion was established in 30 Sprague-Dawley male rats, and another five rats were employed as non-contused controls. Morphometrically, the data obtained from the numbers of Pax7 + , MyoD + , and myogenin + cells were highly correlated with the wound age. Pax7, MyoD, myogenin, and IGF-1 expression patterns were upregulated after injury at both the mRNA and protein levels. Pax7, MyoD, and myogenin protein expression levels confirmed the results of the morphometrical analysis. Additionally, the relative quantity of IGF-1 protein > 0.92 suggested a wound age of 3 to 7 days. The relative quantity of Pax7 mRNA > 2.44 also suggested a wound age of 3 to 7 days. Relative quantities of Myod1, Myog, and Igf1 mRNA expression > 2.78, > 7.80, or > 3.13, respectively, indicated a wound age of approximately 3 days. In conclusion, the expression levels of Pax7, MyoD, myogenin, and IGF-1 were upregulated in a time-dependent manner during skeletal muscle wound healing, suggesting the potential for using them as candidate biomarkers for wound age estimation in skeletal muscle.

Comparison of CT Values between Thrombus and Postmortem Clot Based on Cadaveric Pulmonary Angiography.

OBJECTIVES: To explore the difference in CT values between pulmonary thromboembolism and postmortem clot in postmortem CT pulmonary angiography (CTPA) to further improve the application value of virtual autopsy. METHODS: Postmortem CTPA data with the definite cause of death from 2016 to 2019 were collected and divided into pulmonary thromboembolism group (n=4), postmortem clot group (n=5), and control group (n=5). CT values of pulmonary trunk and left and right pulmonary artery contents in each group were measured and analyzed statistically. RESULTS: The average CT value in the pulmonary thromboembolism group and postmortem clot group were (168.4±53.8) Hu and (282.7±78.0) Hu, respectively, which were lower than those of the control group (1 193.0±82.9) Hu (P<0.05). The average CT value of the postmortem clot group was higher than that of the pulmonary thromboembolism group (P<0.05). CONCLUSIONS: CT value is reliable and feasible as a relatively objective quantitative index to distinguish pulmonary thromboembolism and postmortem clot in postmortem CTPA. At the same time, it can provide a scientific basis to a certain extent for ruling out pulmonary thromboembolism deaths.

Virtual Autopsy Morphological Features of Drowning.

OBJECTIVES: To explore the application value of virtual autopsy to obtain key evidence information on drowned corpses and its application value of virtual autopsy in the diagnosis of drowning. METHODS: In this study, 7 corpses were selected as the research objects. The image data of corpses were collected by computed tomography (CT) before conventional autopsy. The characteristics of corpses were observed through image reading, combined with virtual measurement indexes, and compared with 15 non-drowned corpses. RESULTS: The postmortem CT of drowning showed the more fluid in respiratory tract than the non-drowning, and ground-glass opacities in the lung. The statistical volume of fluid in the sinus (maxillary sinus and sphenoid sinus) was (10.24±4.70) mL in drowning cases and (2.02±2.45) mL in non-drowning cases. The average CT value of fluid in the sinus, left atrial blood and gastric contents in drowning cases were (15.91±17.20), (52.57±9.24) and (10.33±12.81) HU, respectively, which were lower than those in non-drowning cases (P<0.05). CONCLUSIONS: The comprehensive consideration of multiple characteristic image manifestations and the virtual measurement indexes are helpful to the forensic pathological diagnosis of drowning. Virtual autopsy can be used as an auxiliary method in the forensic diagnosis of drowning.

Research Progress of Automatic Diatom Test by Artificial Intelligence.

Diatom test is the main laboratory test method in the diagnosis of drowning in forensic medicine. It plays an important role in differentiating the antemortem drowning from the postmortem drowning and inferring drowning site. Artificial intelligence (AI) automatic diatom test is a technological innovation in forensic drowning diagnosis which is based on morphological characteristics of diatom, the application of AI algorithm to automatic identification and classification of diatom in tissues and organs. This paper discusses the morphological diatom test methods and reviews the research progress of automatic diatom recognition and classification involving AI algorithms. AI deep learning algorithm can assist diatom testing to obtain objective, accurate, and efficient qualitative and quantitative analysis results, which is expected to become a new direction of diatom testing research in the drowning of forensic medicine in the future.

Comparison among Four Deep Learning Image Classification Algorithms in AI-based Diatom Test.

OBJECTIVES: To select four algorithms with relatively balanced complexity and accuracy among deep learning image classification algorithms for automatic diatom recognition, and to explore the most suitable classification algorithm for diatom recognition to provide data reference for automatic diatom testing research in forensic medicine. METHODS: The "diatom" and "background" small sample size data set (20 000 images) of digestive fluid smear of corpse lung tissue in water were built to train, validate and test four convolutional neural network (CNN) models, including VGG16, ResNet50, InceptionV3 and Inception-ResNet-V2. The receiver operating characteristic curve (ROC) of subjects and confusion matrixes were drawn, recall rate, precision rate, specificity, accuracy rate and F1 score were calculated, and the performance of each model was systematically evaluated. RESULTS: The InceptionV3 model achieved much better results than the other three models with a balanced recall rate of 89.80%, a precision rate of 92.58%. The VGG16 and Inception-ResNet-V2 had similar diatom recognition performance. Although the performance of diatom recall and precision detection could not be balanced, the recognition ability was acceptable. ResNet50 had the lowest diatom recognition performance, with a recall rate of 55.35%. In terms of feature extraction, the four models all extracted the features of diatom and background and mainly focused on diatom region as the main identification basis. CONCLUSIONS: Including the Inception-dependent model, which has stronger directivity and targeting in feature extraction of diatom. The InceptionV3 achieved the best performance on diatom identification and feature extraction compared to the other three models. The InceptionV3 is more suitable for daily forensic diatom examination.

Functional and Transcriptomic Characterization of a Dye-decolorizing Fungus from Taxus Rhizosphere.

We isolated three laccase-producing fungus strains from Taxus rhizosphere. Myrotheium verrucaria strain DJTU-sh7 had the highest laccase activity of 216.2 U/ml, which was increased to above 300 U/ml after optimization. DJTU-sh7 had the best decolorizing effect for three classes of reactive dyes. The DJTU-sh7-containing fungal consortium displayed the robust decolorizing ability. Both color removal efficiency and chemical oxygen demand were increased in the consortium mediated biotransformation. Transcriptome changes of M. verrucaria elicited by azo dye and phenolic were quantified by the high throughput transcriptome sequencing, and the activities of the selected oxidases and reductases were determined. The possible involvement of oxidases and reductases, especially laccase, aryl alcohol oxidase, and ferric reductase in the biotransformation of dye and phenolic compounds was revealed at both transcriptomic and phenotypic levels. Revealing the transcriptomic mechanisms of fungi in dealing with organic pollutants facilitates the fine-tuned manipulation of strains in developing novel bioremediation and biodegradation strategies.We isolated three laccase-producing fungus strains from Taxus rhizosphere. Myrotheium verrucaria strain DJTU-sh7 had the highest laccase activity of 216.2 U/ml, which was increased to above 300 U/ml after optimization. DJTU-sh7 had the best decolorizing effect for three classes of reactive dyes. The DJTU-sh7-containing fungal consortium displayed the robust decolorizing ability. Both color removal efficiency and chemical oxygen demand were increased in the consortium mediated biotransformation. Transcriptome changes of M. verrucaria elicited by azo dye and phenolic were quantified by the high throughput transcriptome sequencing, and the activities of the selected oxidases and reductases were determined. The possible involvement of oxidases and reductases, especially laccase, aryl alcohol oxidase, and ferric reductase in the biotransformation of dye and phenolic compounds was revealed at both transcriptomic and phenotypic levels. Revealing the transcriptomic mechanisms of fungi in dealing with organic pollutants facilitates the fine-tuned manipulation of strains in developing novel bioremediation and biodegradation strategies.

Sulforaphane attenuates di-N-butylphthalate-induced reproductive damage in pubertal mice: Involvement of the Nrf2-antioxidant system.

di-N-butylphthalate (DBP) is a ubiquitous environmental pollutant used for plastic coating and in the cosmetics industry. It has toxic effects on body health, especially the male reproductive system. Here, we investigated the effects of DBP on the male reproductive system of pubertal mice and explored the protective role of sulforaphane (SFN). The results showed that DBP significantly reduced the anogenital distance, testicular weight, sperm count and motility, and plasma and testicular testosterone levels and significantly increased the oxidative stress, sperm abnormalities, and testicular cell apoptosis. SFN supplementation ameliorated these effects. After DBP stimulation, the transcription factor nuclear factor erythroid-related factor 2 (Nrf2) was adaptively increased together with its target genes, such as HO-1 and NQO1. Upregulation of Nrf2 by SFN reduced the DBP-mediated intracellular oxidative toxicity and also increased testosterone secretion and spermatogenesis, which were decreased by DBP. These findings indicate that SFN can attenuate DBP-induced reproductive damage in pubertal mice via Nrf2-associated pathways.

[Research Progress on the Role of Small Non-coding RNA in Schistosoma Infection].

Small non-coding RNA controls the expression of target genes and is related with mRNA degradation, chromatin modification and genome stability. Recent studies showed that small non-coding RNA is not only associated with the incidence of schistosomiasis, but also acts as a potential biomarker. In this article, we will review the applications of small non-coding RNA in schistosomiasis diagnosis and its potential role in schistosome development and pathogenesis, in the aim to provide hints for developing detection methods and vaccines for schistosomiasis and for drug development.

[Risk Assessment of Schistosomiasis Transmission by Catalytic Models Based on Antibody Positive Rates].

Objective: To evaluate the transmission risk and features of schistosomiasis by analyzing the data concerning positive rates of anti-schistosome antibody using catalytic models. Methods: Cross-sectional survey was conducted in seven villages with different endemicity of schistosomiasis in Jiangxi (Caohui, Xinhua, Jingtou villages), Anhui (Yuye, Tieguai, Longshang villages) and Hubei (Hebei village) Provinces in 2008. Serum samples were collected and indirect hemagglutination assay was performed to detect anti-schistosome antibodies in serum. Antibody positive rate was calculated and differences among villages and age groups as well as between genders were analyzed. Data of antibody positive rate based on age strata for each village were analyzed by two-stage catalytic model and reversible and two-stage compound catalytic model. Parameters of each model were estimated through the maximum likelihood method. Seroconversion rate and sero-negative conversion rate were estimated in the two-stage catalytic model. Seroconversion rate, seroreversion rate and sero-negative conversion rate were estimated in reversible and two-stage compound catalytic model. The fitting effect was evaluated through correlation analysis and chi-square tests. The best fitted models and parameters were used to analyze the transmission risk and characteristics of schistosomiasis. Results: A total of 6 428 individuals were examined with an average schistosomiasis antibody positive rate of 39.80%（2 485/6 428）. In terms of age, the peak of antibody positive rate in Caohui, Xinhua, Jingtou, Yuye, Tieguai, Longshang, and Hebei villages occurred in the age group of 46-50 （82.86%, 58/70）, 31-35 （60.78%, 31/51）, 31-35 （68.42%, 26/38）, 41-45（55.04%, 71/129）, 51-55 （62.38%, 63/101）, 56-60 （31.43%, 33/105）, and 16-20 （21.88%, 7/32） years old, respectively. In general, the antibody positive rate showed a trend of increase followed by a decrease with increasing age in each village. The best model for the data of Caohui, Xinhua and Jingtou and Yuye village was the two-stage catalytic model. The estimated seroconversion rate in these villages was 0.049 5, 0.044 0, 0.055 7, and 0.034 4 respectively, all higher than the corresponding sero-negative conversion rate of 0.005 9, 0.019 6, 0.015 5, and 0.017 8. The best model for the data of Longshang, Tieguai and Hebei villages was the reversible and two-stage compound model. The seroconversion rate in these villages was 0.062 9, 0.168 1, and 0.039 4 respectively, the seroreversion rate was 0.168 8, 0.121 1, and 0.152 2, and the sero-negative conversion rate was 0.001 7, 0.000 2, and 0.090 9. Conclusions: The catalytic model based on antibody positive rate by age strata could reflect the transmission rate and risk quantitatively and may provide guidance for making control strategies.

[Resistance of rAAV2-MfE77.43-Transferred Mice to Schistosoma japonicum Infection].

Objective: To investigate the resistance of E77.43 gene of Microtus fortis（MfE77.43） to Schistosoma japonicum infection. Methods: MfE77.43 was constructed into the recombinant Adeno-associated virus AAV2. The AAV2-MfE77.43 was transfected into HEK293 cells by the calcium phosphate DNA coprecipitation method. The recombinant rAAV2-MfE77.43 was purified and total RNA was extracted from the transfected cells. The expression of E77.43 was examined by RT-PCR and the purity of rAAV2-MfE77.43 was analyzed by SDS-PAGE. Eighteen KM mice were divided into three groups （n=6 in each group）. Mice in the experiment group were intramuscularly injected on days 0, 3 and 7 with 400 µl recombinant AAV2-MfE77.43 virus which was 5-fold diluted in normal saline. Mice in negative control and blank control groups received same volume of pAAV or normal saline. Venous blood was collected through the tail before each injection, and E77.43 expression in plasma was detected by dot-ELISA method. After the last injection, each mouse was infected with 40 S. japonicum cercariae and sacrificed on day 41 after infection. Adult worms and liver eggs per gram（LEPG） were counted. Worm and egg reduction rate was calculated respectively. Egg granulomas were observed by HE staining. Results: RT-PCR resulted in a 330 bp specific band. SDS-PAGE of virus shell protein revealed three protein bands with M(r) of 87 000, 72 000 and 62 000, respectively. Dot-ELISA showed that E77.43 protein began to be expressed on day 3 after rAAV2-MfE77.43 injection, remaining stable till day 41. The adult worm number and LEPG were 20.16±3.93 and 19 800±2 715, respectively, with a worm and egg reduction rate of 27.3% and 26.2% in the experiment group. While the worm number and LEPG in the negative control group were 29.16±2.44 and 28 000±2 192（P<0.01）, respectively. HE staining and observation revealed fewer eosinophils and inflammatory cells around the liver eggs in the therapy group. Conclusion: The E77.43 gene shows protective effects against S. japonicum infection, indicating that E77.43 may participate in the natural resistance of Microtus fortis to S. japonicum infection.

[Comparison of Postmortem MSCT and Autopsy Findings in Traffic Accident Victims].

OBJECTIVE: To explore the application value of postmortem multi-slice spiral computed tomography (MSCT) by observing and analyzing the injury features in the traffic accident victims. METHODS: Ten traffic accident victims were scanned with whole body MSCT. The systemic autopsy was subsequently performed to compare with the results of MSCT. The advantages and disadvantages of autopsy and MSCT for obtaining the information of traffic accident injuries were then analyzed. RESULTS: MSCT could reveal 3D shape of fractures clearly and detect air accumulation in different positions of the body, which showed the obvious advantages compared with autopsy. However, the resolution of MSCT was limited compared to the detection of organ and soft tissue injuries. CONCLUSION: A combination of MSCT and autopsy is the best way for determining the manner and the cause of death in traffic fatality victims.

Determination of a Newborn with Lethal Type II Osteogenesis Imperfecta and Other Anomalies Using Autopsy and Postmortem MSCT--A Case Report.

A case of a stillbirth with lethal type II osteogenesis imperfecta (OI) was reported. The fetus had skull fractures and craniocerebral injuries during pregnancy. Postmortem multi-sliced computed tomography (MSCT) and 3D-reconstruction were performed, followed by a medico-legal autopsy. The autopsic findings showed the typical features of type II OI, including a soft calvarium, deformed extremities, flexed and abducted hips, and uncommon features, such as white sclera, coxa vara, absence of several bones and organs, a cleft lip, and asymmetric ears. The radiologic images revealed such anomalies and variations as a cleft palate, mandibular dysplasia, spina bifida, costa cervicalis, and fusion of the ribs and vertebrae, which were difficult to detect during conventional autopsy. The paper investigated the classification, causative mutation, cause of death, and the differentiation of OI from child abuse, coming to a conclusion that OI knowledge can be of great importance to forensic pathologists and that the merits of postmortem MSCT should be emphasized in forensic pathologic examinations.

[Progress on Diatom Test in Drowning Cases].

In drowning cases, it is difficult to judge whether the deceased died from drowning or throwing into the water after killed or identificate the cause of death of the decomposed corps in forensic practices. The diatom test is still considered as the important assistant evidence in drowning cases. This paper reviews research progress on technologies in recent years of forensic diatom test, and the application value of the new developing approach in the field of forensic medicine.

[Fourier Transform Infrared Microspectroscopy of Rat Kidney with Regard to Fa- tal Hyperthermia].

OBJECTIVE: To observe the chemical groups changing in rat kidney with regard to fatal hyperthermia by Fourier transform infrared microspectroscopy (FTIR-MSP) and to provide a new method to diagnose fatal hyperthermia. METHODS: Rats were sacrificed by hyperthermia, brainstem injury, massive hemorrhage and asphyxiation and divided into groups. The renal samples were dissected immediately after death. The data of infrared spectroscopy in glomerulus were measured by FTIR-MSP. RESULTS: The absorbances of 3290, 3070, 2850, 1540 and 1396 cm(-1) significantly increased (P < 0.05), and the ratios of Al650/A3290 and A1650/A1540 significantly decreased (P < 0.05) in group of hyperthermia. CONCLUSION: FTIR-MSP can analyze the changes of chemical groups of kidney as an auxiliary diagnosis for discriminating hyperthermia with other causes of death.

[Research Advances in Postmortem Chemistry].

Postmortem chemistry is becoming more and more essential in routine forensic pathology and has made considerable progress over the past years. Biochemical analyses of vitreous humor, blood, urine and cerebrospinal fluid may provide important information in determining the cause of death or in elucidating forensic issues. Postmortem chemistry may be essential for the determination of cause of death when morphological methods (diabetes mellitus, alcoholic ketoacidosis and electrolytic disorders) cannot detect the pathophysiological changes involved in the death process. It can also provide many information in other forensic situations, including myocardial ischemia, sepsis, inflammation, infection, anaphylaxis and hormonal disturbances. The most recent relevant research advances on glucose metabolism, liver function, cardiac function, renal function, sepsis, inflammation, infection, anaphylaxis and hormonal aspect are hereby reviewed.

[Application of MSCT in the identification and analysis of traffic accidents: 2 fatal cases].

OBJECTIVE: To explore the application value of multi-slice spiral computed tomography (MSCT) in traffic accidents through observing and analyzing the injury features of the accidents. METHODS: Two fatal cases caused by traffic accidents were fully examined using MSCT, 3D imaging reconstruction and angiography through cardiac puncture. The features of traffic injury mechanism were analyzed through combination of MSCT and postmortem external examination. RESULTS: In case 1, right cardiac rupture was found by MSCT and angiography through cardiac puncture. The cause of death was cardiac tamponade and right ventricular rupture due to the crush injury of chest in the traffic accident. In case 2, splenic rupture and intra-abdominal hemorrhage was found and caused by injury of left trunk by MSCT. The cause of death was hemorrhage and traumatic shock. CONCLUSION: MSCT could observe skeletal injury, soft tissue injury, and hematologic disorder well. The combination use of MSCT and angiography through cardiac puncture provided assistance to the diagnosis of cardiovascular system injury.

[Analysis of biochemical markers in serum of guinea pigs after death caused by hypothermia].

OBJECTIVE: To explore the changes and rules of biochemical markers in serum of guinea pigs after death caused by hypothermia and to provide references for fatal hypothermia diagnosis by serum biochemical markers. METHODS: Twenty guinea pigs were randomly divided into experimental group and control group. The guinea pigs in the experimental group were kept at -30 °C until death, while the ones in control group were decapitated after same survival intervals at 25 °C. The serum was extracted from the whole blood of right ventricular immediately. Subsequently, a series of serum biochemical markers were analyzed by auto bio-chemical analyzer. RESULTS: The levels of glucose, uric acid, creatinine and urea nitrogen in the experimental group were significantly higher than those in control group, respectively (P<0.05). Compared with the control group, the levels of total protein and albumin were significantly lower in the experimental group (P<0.05). There were no significantly differences of the levels of other markers such as serum enzymes and ions observed between the two groups. CONCLUSION: There are characteristic changes of some specific serum biochemical markers in fatal hypothermia, which may be potentially useful for auxiliary diagnosis of fatal hypothermia.

Severe hypokalemia due to combination use of dexamethasone and calcium gluconate for diabetics with infection: a case report.

The combination use of dexamethasone and calcium gluconate can be applied to hypersensitivity. Severe hypokalemia is a usual complication of dexamethasone and calcium gluconate therapy, which occurs frequently with therapeutic use. Fatal cases, accidental and intentional, occur frequently in forensic practice. The current case report presented a 43-year-old man with diabetes mellitus with infection, to whom dexamethasone and calcium gluconate were administered in the private clinic. With the development of such clinical symptoms of severe hypokalemia as quadriplegia, he was confirmed to have severe hypokalemia through a biochemical test before dying of arrhythmia. And also it presented pathophysiologic mechanism underlying severe hypokalemia as well as suggestions for clinical practice regarding combination use of dexamethasone and calcium gluconate.

Postmortem MSCT diagnosis of whiplash injuries in a traffic accident: a case report and review of the literature.

A 45-year-old male car driver died in a traffic accident of four cars rear-end collision on the highway. He was found to have died after a respiratory and cardiac arrest at the scene. No sign of skin injuries was observed from the external inspection. The autopsy was not permitted by the family members because of the local culture. Multislice computed tomography (MSCT) was applied to the current case, showing dislocation of C3-4 cervical vertebrae with II degree, C4 vertebral plate fractures, and spinal stenosis. Post-mortem MSCT confirmed the diagnosis as whiplash injuries. MSCT was verified to be effective in showing the severity of whiplash injuries, thus providing certain objective evidence for medicolegal expertise.

[Changes of postmortem human blood biochemical indexes].

OBJECTIVE: To investigate and analyze the changes of postmortem human biochemical indexes. METHODS: Subclavian venous blood samples were collected from 81 cases of traffic fatalities. Thirteen blood biochemical indexes including liver function (ALT, AST, TBIL and DBIL), renal function (UA and Cr), cardiac function (CK, CK-MB and LDH), electrolytes (K+, Na+ and Cl-), and glucose (GLU) were tested by Roche cobas c311 automatic biochemical analyzer. The descriptive analysis was made by SPSS 17.0 statistical software. RESULTS: The values of ALT, AST, CK, CK-MB, LDH and K+ were higher than normal reference values with more fluctuations. The values of TBIL, DBIL, UA, Cr, Na+, Cl- and GLU were relatively stable with less fluctuations. CONCLUSION: The postmortem human blood biochemical indexes of liver function, renal function, cardiac function, electrolytes and glucose could be affected by the factors, especially hemolysis and autolysis. The biochemical indexes, particularly enzymes, increased significantly with higher standard deviation.