Transcriptomic Changes of Astrocytes in the Brain of Rats with Subacute METH Exposure / 法医学杂志

OBJECTIVES@#To study the transcriptomic changes of astrocytes in the brain of rats exposed to methamphetamine (METH) and its possible mechanism in neurotoxicity.@*METHODS@#The rats were intraperitoneally injected with METH (15 mg/kg) every 12 h for 8 times in total to establish the subacute rat model of METH. After the model was successfully established, the striatum was extracted, and astrocytes were separated by the magnetic bead method. Transcriptome sequencing was performed on selected astrocytes, and the differentially expressed genes were analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis.@*RESULTS@#A total of 876 differentially expressed genes were obtained by transcriptome sequencing, including 321 up-regulated genes and 555 down-regulated genes. GO analysis revealed that differentially expressed genes were mainly concentrated in cell structure, biological process regulation, extracellular matrix and organelle functions. KEGG pathway enrichment analysis showed that steroids biosynthesis, fatty acid biosynthesis, peroxisome proliferators-activated receptor (PPAR), adenosine 5'-monophosphate-activated protein kinase (AMPK) and other signaling pathways were significantly changed.@*CONCLUSIONS@#METH can cause structural changes of astrocytes through multiple targets, among which cellular structure, steroids biosynthesis and fatty acid biosynthesis may play an important role in nerve injury, providing a new idea for forensic identification of METH related death.

Retrospective Analysis of 61 Cases of Children Died of Viral Pneumonia / 法医学杂志

Objective To retrospectively analyze the forensic pathological postmortem examination and clinical data of children who died of viral pneumonia in identification of cause of death cases and to discuss the clinical characteristics and pathological features of viral pneumonia in children, in order to provide reference to pathological diagnosis of viral pneumonia in children caused by 2019 novel coronavirus （2019-nCoV） infection. Methods Postmortem examination data from 61 cases of children whose causes of death were identified as viral pneumonia in recent years were collected from the Center of Forensic Identification, Southern Medical University. The gender, age, clinical symptoms and pathological features were comparatively analyzed. Results Among the 61 cases of children who died of viral pneumonia, most were within 2 years old （83.61%）, and a large proportion died within 2 weeks after the onset of the disease （91.80%）. Gross changes in postmortem examination included respiratory mucosal hyperemia, pleural effusion, pulmonary swelling, variegated pulmonary pleura and serosa, as well as focal pulmonary hemorrhage and pulmonary edema. A large proportion of sick children had enlarged mesenteric lymph nodes （83.61%） and thymic dysplasia （21.31%）. Histopathological changes included edema of alveoli and interstitial substance, pneumorrhagia，shedding of alveolar epithelial cells, serous and （or） fibrous exudation in the alveoli, formation of viral inclusions, formation of transparent membranes, infiltration of inflammatory cells that mainly consisted of macrophages and lymphocytes in interstitial substance and alveoli. Viral infections often affected the heart and gastrointestinal tract. Conclusion The clinical symptoms of children with viral pneumonia are difficult to notice, and because the immune systems of children are not fully developed and they have poor immunity, they can easily become severely ill and even die. Analyzing the forensic autopsies and the histopathological characteristics could provide reference for pathological diagnosis of viral pneumonia.

Retrospective Analysis of 291 Cases of Medical Malpractice Involving Death / 法医学杂志

Objective To study the medical malpractice cases involving death, and discuss the identification ideas and methods of medical malpractice cases. Methods A total of 291 medical malpractice cases involving death accepted and settled from January 2012 to December 2017 at the Judicial Appraisal Center of Southern Medical University were collected. Based on the age, gender, hospital level, clinical department, whether or not autopsy was performed, cause of death, cause of medical mistakes, causality and causative potency of the appraised person, statistical analysis was made. Results There were more males than females in medical malpractice cases involving death. Mostly young adults or children were involved in these cases. The number of cases involving tertiary hospitals was the highest; among the clinical departments, the internal medicine department had the largest number of cases, followed by surgery, obstetrics and gynecology, pediatrics, etc. Autopsy rate has a trend of increasing year by year. Most patients die from the natural outcomes of their disease or ineffective treatment. Most hospitals have certain medical mistakes, and have an indirect correlation with the patient's death, mainly slight factors. Conclusion Judicial appraisal of medical malpractice should follow the principle of "one-effect and multi-cause", and comprehensively consider various factors such as, the diseases and constitution of the patient, natural outcomes of the diseases, the current medical technology and the level of diagnosis and treatment of the hospital, etc.

Infantile DiGeorge syndrome: autopsy diagnosis and clinicopathologic analysis in 5 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate clinicopathological features of DiGeorge syndrome (DGS).</p><p><b>METHOD</b>The clinical features, histological and immunohistochemical findings were analyzed in 5 cases of DGS by autopsy.</p><p><b>RESULTS</b>Five cases of DGS in male infants aged 4 days, 1 month, 7 months, 10 months, and 13 months respectively. Gross and microscopic observations revealed that thymic cortex was depleted of lymphocytes or showed few, dispersed lymphocytes. The thymic medulla showed predominantly epithelial cells with calcified Hassall bodies as well as lymphocyte depletion. T lymphocytes were also scarce in the tonsils, lymph nodes, spleen, and mucosa-associated lymphatic tissue of ileum. In addition, 3 of the 5 patients also showed parathyroid aplasia or dysplasia, and congenital hypertrophy of the ventricular septum.</p><p><b>CONCLUSIONS</b>The pathological changes indicate that clinicians should be aware of defects of immune system if the infants suffer from severe infections. Pathologists should recognize the importance of abnormalities of lymphohematopoietic tissues in the diagnosis of primary immunodeficiency diseases such as DGS.</p>

The microglia activation characteristics of MA-induced neurotoxicity in the rats striatum / 法医学杂志

OBJECTIVE@#To investigate the activation characteristics of microglia (MG) in the rats striatum with MA-induced neurotoxicity.@*METHODS@#Male Wistar rats were divided randomly into control group (n=24) and experimental group (n=24). The rats of experimental group were injected intraperitoneally with MA (15 mg/kg x 8 injections, at 12 hours interval). The rats of control group were administrated with saline. The tissues of striatum of two rat groups were harvested at 0.5 d, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d and 7 d post initial administrations of MA or saline. The structure changes were observed by transmission electron microscopy and CD-11b immunohistochemistry. The ratio of activated MG was calculated and statistically analyzed.@*RESULTS@#In the control group, the morphological characteristics of the MG showed that the cell bodies were small with slender processes, high electronic density nucleus, and fewer organelles known as the "fork-type". In contrast, the MG in the MA-induced neurotoxicity group displayed larger cell body, shorter cell processes or disappeared, lower electronic density nucleus and rich organelles, resembling "bush-like" or "amoeba-like". The ratio of activated MG in control group was below 0.15 at all timepoints, whereas in the experimental group, the ratio of activated MG increased significantly from day 1 to day 7 (P<0.001).@*CONCLUSION@#The continuous MA stimulation of the CNS results in prominent MG activation.

Effect of methamphetamine on the microglial cells and activity of nitric oxide synthases in rat striatum / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes in the microglial cells and the activity of nitric oxide synthase (NOS), inducible nitric oxide synthase (iNOS) and constitutive nitric oxide synthase (cNOS) in the striatum of rats with methamphetamine (METH) treatment.</p><p><b>METHODS</b>The rats were randomly divided into two groups for injections with METH or saline. Specific antibody against OX-42 was used to detect the changes in the morphology and the number of microglia, and the activities of NOS, iNOS and cNOS were compared between the two groups.</p><p><b>RESULTS</b>The microglial cells were activated and their number significantly increased in the striatum of rats with METH treatment as compared with those in the saline group. The activated microglial cells showed bushy and amoeboid morphologies in the METH group. METH also significantly enhanced the activities of NOS, iNOS and cNOS in the striatum (P < 0.05).</p><p><b>CONCLUSION</b>Microglial activation and increased NOS activity may participate in METH-induced neurotoxicity in rat striatum.</p>

As2O3-induced permeability transition pore opening in mitochondria depends on Ca2+ / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the mechanism of arsenite-induced permeability transition pore (PTP) opening and the role of Ca(2+). in As(2)O(3)-induced PTP opening.</p><p><b>METHOD</b>The mitochondria were prepared from Wistar rat liver and mitochondrial swelling was assessed spectrophotometrically at 540 nm to evaluate PTP opening. The membrane potential of the mitochondria was measured with fluorescence spectrophotometry.</p><p><b>RESULTS</b>PTP opening was induced with 10 micromol/L As(2)O(3) in the presence of 10 micromol/L Ca(2+), and the absorbance at 540 nm of the mitochondria did not decrease in response to exclusive treatment with 10 micromol/L As(2)O(3), or to 10 micromol/L As(2)O(3) plus 10 micromol/L Ca(2+) treatment with 0.5 mmol/L EGTA pretreatment. Treatment with As(2)O(3) at 0, 5, 10 and 20 micromol/L in the presence of 50, 20, 10 and 5 micromol/L Ca(2+), respectively, resulted in decreased absorbance at 540 nm of the mitochondria.</p><p><b>CONCLUSION</b>Ca(2+) mediates As(2)O(3)-induced PTP opening. As(2)O(3) lowers Ca(2+) threshold necessary for eliciting PTP opening and thereby regulates cell apoptosis.</p>