Objective To explore the application of neutrophil migration distance for wound age estimation of skeletal muscles in rats, and to provide methodological basis for follow-up study in future. Methods The skeletal muscle contusion model was established in rats, and the control group and the 2, 4, 6 h post-traumatic groups were set. The law of response of neutrophils that participated in the inflammation after injury was detected by immunohistochemical staining, and the relationship between neutrophil migration distance and injury time was detected by TissueFAXS PLUS software. Results The skeletal muscle was obviously infiltrated with neutrophils 2-6 h after injury. The positive rate of neutrophil was （28.75±0.94）% at 2 h post-traumatic, and reached the peak （45.50±3.63）% at 4 h post-traumatic, then decreased to （31.92±1.56）% at 6 h post-traumatic. The neutrophil migration distances increased with the progress of inflammation, and reached （124.80±12.32） μm, （229.03±21.45） μm and （335.04±16.75） μm at 2 h, 4 h and 6 h, respectively. Conclusion There is a relationship of neutrophil infiltrated number and migration distance and wound age within the 2-6 h after skeletal muscle injury, which could be used for the inference of skeletal muscle wound age.
Animals ; Contusions/metabolism* ; Follow-Up Studies ; Muscle, Skeletal/pathology* ; Neutrophil Infiltration ; Neutrophils ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVE: To analyze the morphological features and forensic pathological characteristics of cardiac ruptures of different causes for their differential diagnosis. METHODS: We analyzed the data of 44 autopsy cases of cardiac rupture from 2014 to 2017 in our institute, including 11 cases caused by blunt violence with intact pericardium, 4 caused by cardiopulmonary resuscitation (CPR), 9 by myocardial infarction, and 20 by aorta dissection rupture.The gross features and histopathological characteristics of cardiac rupture and pericardial effusion were analyzed and compared. RESULTS: Cardiac ruptures caused by blunt violence varied in both morphology and locations, and multiple ruptures could be found, often accompanied with rib or sternum fractures; the volume of pericardial effusion was variable in a wide range; microscopically, hemorrhage and contraction band necrosis could be observed in the cardiac tissue surrounding the rupture.Cardiac ruptures caused by CPR occurred typically near the apex of the right ventricular anterior wall, and the laceration was often parallel to the interventricular septum with frequent rib and sternum fractures; the volume of pericardial blood was small without blood clots; microscopic examination only revealed a few hemorrhages around the ruptured cardiac muscular fibers.Cardiac ruptures due to myocardial infarction caused massive pericardial blood with blood clots, and the blood volume was significantly greater than that found in cases of CPR-induced cardiac rupture ( < 0.05);lacerations were confined in the left ventricular anterior wall, and the microscopic findings included myocardial necrosis, inflammatory cell infiltration, and mural thrombus.Cardiac tamponade resulting from aorta dissection rupture was featured by massive pericardial blood with blood clots, and the blood volume was much greater than that in cases of cardiac ruptures caused by blunt violence, myocardial infarction and CPR ( < 0.05). CONCLUSIONS Hemorrhage, inflammatory cell infiltration, and lateral thrombi around the cardiac rupture, along with pericardial blood clots, are all evidences of antemortem injuries.
Aneurysm, Dissecting ; complications ; Aortic Aneurysm ; complications ; Cardiopulmonary Resuscitation ; adverse effects ; Forensic Pathology ; Heart Rupture ; etiology ; pathology ; Heart Rupture, Post-Infarction ; pathology ; Humans ; Myocardial Contusions ; complications

OBJECTIVES: To explore the differences in the repair process of skin and skeletal muscle after contusion caused by blunt force attack with different heights. METHODS: Three degrees of contusion were performed on SD rats' right hind limbs by a designed free-dropping device falling from 15, 30 and 50 cm heights, which as a main consideration factor for degree of injury. The repair process of skin and skeletal muscle at 6 h, 24 h, 3 d, 7 d and 13 d after contusion were observed using routine histological methods. RESULTS: Hematoma within skin and/or muscle was found in the rats' hind limbs after contusion with three different heights. The repair processes were similar at 24 h after contusion. However, with the increase of height, the display degree was more obvious. At 3 d after contusion, the RBC of the hemorrhagic region would be decomposed and elapsed in 15 cm contusion group, but for 30 cm contusion group, it delayed to 7 d. At 13 d after contusion, the similar result was found in 15 cm and 30 cm contusion groups, in contrast, the 50 cm contusion group was still in the proliferative phase. CONCLUSIONS With the increase of height, the occurring rate of hematoma within skin and muscle at the same time increases, and the more serious histological appearance after contusion, including inflammation and proliferation, the longer healing process are observed. According to the results of present study and considering forensic application, the contusion model with 50 cm height （2.58 J/cm²） is recommended as the experimental animal model for the future study of wound age estimation on contusion.
Animals ; Contusions/pathology* ; Hindlimb ; Muscle, Skeletal/pathology* ; Rats ; Rats, Sprague-Dawley ; Skin/pathology* ; Wounds, Nonpenetrating

OBJECTIVES: To investigate the time-dependent expression of metallothionein （MT） 1A mRNA and MT2A mRNA in contused skeletal muscle of rats. METHODS: A total of 54 Sprague-Dawley rats were used in this study. The rats were divided into two parts: control group （n=6） and contusion groups （0.5, 1, 6, 12, 18, 24, 30, and 36 h after contusion, n=6）. Total RNA was extracted from skeletal muscle. The expression levels of MT1A mRNA and MT2A mRNA were detected by SYBR Green I real-time PCR. RESULTS: The expression trends of the two potential marker genes were related to wound age. In addition to 0.5 h, there were significant contrasts between the control group and contused group （P<0.05）, about the expression levels of MT1A mRNA and MT2A mRNA in different phases. As the extension of wound age, the relative expression of MT1A mRNA and MT2A mRNA at 1 h, 6 h, 12 h and 18 h after contusion demonstrated upgrade tendency until its expression levels in 18 h peak with 239.41±15.20 and 717.42±50.76, respectively. When time extends to 24 h after injury, the expression of above two marks decreased, respectively. The MT1A mRNA and MT2A mRNA expression levels increased at 30 h and then decreased. CONCLUSIONS Determination of MT1A mRNA and MT2A mRNA levels by real-time PCR may be useful for the estimation of wound age.
Animals ; Contusions/pathology* ; Gene Expression Regulation ; Genetic Markers ; Metallothionein ; Muscle, Skeletal/metabolism* ; RNA, Messenger/metabolism* ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Time Factors ; Wound Healing

OBJECTIVE: To map the progression of osteoporosis following spinal cord injury in mice in specific areas and analyze changes in parathyroid hormone (PTH) and ion levels which could be responsible for overall bone loss. SUMMARY OF BACKGROUND DATA: Spinal cord injury rapidly induces severe bone loss compared to other conditions, yet the cause of this bone loss has not been identified. Studies suggest the bone loss after injury is not solely due to disuse. METHODS: To quantify bone loss we weighed individual bones and measured bone mineral density using dual energy X-ray absorptiometry at acute (1 week) and chronic (4 week) time points following a T9 contusion. An ELISA was used to measure blood PTH levels at 1 and 4 weeks after injury. Calcium and phosphate levels were also analyzed at 4 weeks following injury at the University of Miami pathology core. RESULTS: We observed a significant decrease in bone mineral density in hind limbs after an acute injury, and found this bone loss to progress over time. Furthermore, following chronic injury a decrease in bone mineral density is also observed in bones above the level of injury and in the total bone mineral density. We observed a significant decrease in parathyroid hormone levels in injured mice at the chronic time point, but not at the acute time point which suggests this could be involved in the global bone loss following injury. We also observed a significant increase in serum calcium levels following injury which could account for the imbalance of PTH levels.
Absorptiometry, Photon ; Animals ; Bone Density ; Calcium ; Contusions ; Enzyme-Linked Immunosorbent Assay ; Extremities ; Mice* ; Osteoporosis ; Parathyroid Hormone ; Pathology ; Spinal Cord Injuries* ; Spinal Cord*

OBJECTIVE: In order to understand which kind of function genes play an important role for estimating wound age, the variation of difference genes' mRNA expression were compared after injury. METHODS: The mRNA expression levels of seven candidate genes (ICAM-1, NF-κB, MX2, MT1, MT2, sTnI, and Cox6c) were analyzed in contused rat skeletal muscle at different time points using real-time fluorescent quantitative PCR (RT-qPCR). The raw Ct values were normalized relative to that of RPL32 mRNA, and converted to standard Ct values. At each time point after injury, the standard deviations (SD) of the standard Ct values were calculated by SPSS. RESULTS: The expression trends of the seven genes were all found to be related to wound age, but there were lower variation coefficients and greater reliability of s TnI and Cox6c when compared with other genes. CONCLUSION The genes encoding structural proteins or proteins that perform basic functions can be suitable for wound age estimation.
Animals ; Contusions/genetics* ; Forensic Pathology ; Gene Expression Profiling ; Intercellular Adhesion Molecule-1 ; Muscle, Skeletal/metabolism* ; NF-kappa B ; Proteins ; RNA, Messenger/metabolism* ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Regression Analysis ; Reproducibility of Results ; Time Factors ; Wound Healing/genetics*

OBJECTION: To investigate the time-dependent appearance of circulating fibrocytes of skeletal muscle in rats after contusion. METHODS: The model of skeletal muscle wound was established in rat. The circulating fibrocytes in contused skeletal muscle were detected by CD45 and procollagen I double immunofluorescence staining method. RESULTS: In the control group, CD45- and procollagen I-positive cells were not detected in skeletal muscle. A few CD45 cells were observed aged from 6 h to 1 d after contusion. A few CD45- and procollagen I-positive cells (fibrocytes) initially gathered in injury area 3d after injury. The ratio of positive fibrocytes significantly increased 5 d after injury. The ratio of fibrocytes was highest at 7 d after contusion and then decreased. The volume of fibrocytes showed bigger with injury time increase compared with 3 d group. The expression of procollagen I and CD45 were weakened at 14d after injury. CONCLUSION The circulating fibrocytes are detected in contused skeletal muscle in time-dependent pattern. Circulating fibrocytes may be a marker in the wound age determination for contused skeletal muscle.
Animals ; Biomarkers/metabolism* ; Collagen Type I/metabolism* ; Contusions/pathology* ; Disease Models, Animal ; Forensic Pathology ; Immunohistochemistry ; Leukocyte Common Antigens/metabolism* ; Male ; Mesenchymal Stem Cells/metabolism* ; Microscopy, Fluorescence ; Muscle, Skeletal/pathology* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Wound Healing

OBJECTIVE: To compare the expression of tumor necrosis factor-alpha (TNF-alpha) between brain and peripheral organs after cerebral contusion in order to provide the scientific theoretical basis for forensic pathological diagnosis and wound age estimation. METHODS: Brain and peripheral organs including heart, liver, spleen, lung, kidney tissues of 45 SD rats after the cerebral contusion were obtained and TNF-alpha of these tissues were analyzed with immunohistochemistry methods. RESULTS: TNF-alpha was detected at 1 h in brain, reaching maximum at 6 h and 3 d after the cerebral contusion, and then decreased but still kept at high expression level at 7 d. TNF-alpha was detected at 1 h after the cerebral contusion in heart, liver, spleen, lung and kidney tissues. The number of cells expressing TNF-alpha increased gradually, reaching maximum at 3 d after the contusion of brain, and then decreased but still kept at high expression level at 7 d. CONCLUSION Besides the change of cerebral contusion, this study considered both the brain and peripheral organs. It is helpful for forensic pathological diagnosis and wound age estimation after contusion of brain.
Animals ; Brain/metabolism* ; Brain Injuries/pathology* ; Contusions/pathology* ; Disease Models, Animal ; Female ; Immunohistochemistry ; Kidney/metabolism* ; Liver/metabolism* ; Lung/metabolism* ; Male ; Rats ; Rats, Sprague-Dawley ; Spleen/metabolism* ; Tissue Distribution ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVE: To explore the general features and the keypoints of forensic medical examination in tumbling injury cases. METHODS: Twenty-eight cases dying of tumbling injury were collected and the locations and features of injury were analyzed. RESULTS: The occiput of head was the common position for the tumbling injury cases. Force, disease and alcohol were the main reasons for tumbling injury. CONCLUSION The injury is mild outside and severe inside from tumbling injury cases. The craniocerebral contrecoup is the significant feature in tumbling injury cases.
Accidental Falls/mortality* ; Adolescent ; Adult ; Aged ; Alcoholism/blood* ; Autopsy ; Cause of Death ; Contusions/pathology* ; Craniocerebral Trauma/pathology* ; Female ; Forensic Pathology ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Scalp/pathology* ; Skull Fractures/pathology* ; Young Adult

Central nervous system (CNS) involvement in acute promyelocytic leukemia (APL) is rare, and the presence of CNS symptoms at the time of diagnosis of APL is even rarer. We report 2 cases of APL presenting with CNS involvement. A 43-yr-old woman presented with easy bruising and stuporous mentality. Her complete blood count (CBC) revealed leukocytosis with increased blasts. Bone marrow (BM) analysis was carried out, and the diagnosis of APL was confirmed. This was done by cytogenetic analysis and demonstration of PML-RARalpha rearrangement by reverse transcriptase PCR in the BM cells. A lumbar puncture was performed to investigate the cause of her stuporous mentality, and her cerebrospinal fluid (CSF) analysis revealed 97% leukemic promyelocytes. Despite systemic and CNS therapy, she died due to septic shock by infection and rapid disease progression only 3 days after her admission. Another patient, a 3-yr-old girl, presented with easy bruising and epistaxis, and her CBC showed pancytopenia with increased blasts. BM studies confirmed APL. Quantitative PCR for PML-RARalpha in the BM cells revealed a PML-RARalpha/ABL ratio of 0.33 and CSF analysis revealed 9.5% leukemic promyelocytes (2 of 21 cells). She received induction chemotherapy and intrathecal therapy and achieved complete remission (CR) in the BM and CNS. She has been maintained in the CR status for the past 31 months. Thus, patients with APL must be evaluated for CNS involvement if any neurological symptoms are present at the time of diagnosis.
Adult ; Antineoplastic Agents/therapeutic use ; Bone Marrow Cells/metabolism/pathology ; Central Nervous System/pathology ; Child, Preschool ; Contusions/etiology ; Epistaxis/etiology ; Female ; Granulocyte Precursor Cells/pathology ; Humans ; Karyotyping ; Leukemia, Promyelocytic, Acute/*cerebrospinal fluid/drug therapy/pathology ; Oncogene Proteins, Fusion/analysis/genetics/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Spinal Puncture ; Tomography, X-Ray Computed ; Tretinoin/therapeutic use