Detection of RAGE expression and its application to diabetic wound age estimation.

With the prevalence of diabetes, it is becoming important to analyze the diabetic wound age in forensic practice. The present study investigated the time-dependent expression of receptor for advanced glycation end products (RAGE) during diabetic wound healing in mice and its applicability to wound age determination by immunohistochemistry, double immunofluorescence, and Western blotting. After an incision was created in genetically diabetic db/db mice and control mice, mice were killed at posttraumatic intervals ranging from 6 h to 14 days, followed by the sampling of wound margin. Compared with control mice, diabetic mice showed the delayed wound healing. In control and diabetic wound specimens, RAGE immunoreactivity was observed in a small number of polymorphonuclear cells (PMNs), a number of macrophages, and fibroblasts. Morphometrically, the positive ratios of RAGE in macrophages or fibroblasts considerably increased in diabetic wounds during late repair, which exceeded 60% at 7 and 10 days post-injury. There were no control wound specimens to show a ratio of >60% in macrophages or fibroblasts. By Western blotting analysis, the ratios of RAGE to GAPDH were >1.4 in all diabetic wound samples from 7 to 10 days post-injury, which were >1.8 at 10 days after injury. By comparison, no control wound specimens indicated a ratio of >1.4. In conclusion, the expression of RAGE is upregulated and temporally distributed in macrophages and fibroblasts during diabetic wound healing, which might be closely involved in prolonged inflammation and deficient healing. Moreover, RAGE is promising as a useful marker for diabetic wound age determination.

Activation of α7nAChR Promotes Diabetic Wound Healing by Suppressing AGE-Induced TNF-α Production.

Diabetes frequently presents accumulation of advanced glycation end products (AGEs), which might induce excessive TNF-α production from macrophages to cause impaired wound healing. Recent studies have shown that activation of α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages efficiently suppressed TNF-α synthesis. The aim of this study was to investigate the accumulation of AGEs in the wounds and determine whether PNU282987, an α7nAChR agonist, can improve wound repair by inhibiting AGE-mediated TNF-α production in a streptozotocin (STZ)-induced diabetic mouse model. Animals were assigned into four groups: wounded control group, wounded diabetic group, wounded diabetic group treated intraperitoneally with PNU282987, or wounded diabetic group treated intraperitoneally with vehicle. Compared with the non-diabetic control mice, the diabetic mice exhibited delayed wound healing that was characterized by elevated accumulation of AGEs, increased TNF-α level and macrophage infiltration, and decreased fibroblast number and collagen deposition at the late stage of repair. Besides, macrophages of diabetic wounds showed expression of α7nAChR. During late repair, PNU282987 treatment of diabetic mice significantly reduced the level of TNF-α, accelerated wound healing, and elevated fibroblast number and collagen deposition. To investigate the cellular mechanism of these observations, RAW 264.7 cells, a macrophage cell line, were incubated with AGEs in the presence or absence of PNU282987. TNF-α production from AGE-stimulated macrophages was significantly decreased by PNU282987 in a dose-dependent manner. Furthermore, PNU282987 significantly inhibited AGE-induced nuclear factor-κB (NF-κB) activation and receptor for AGE (RAGE) expression. These results strongly suggest that activating α7nAChR can promote diabetic wound healing by suppressing AGE-induced TNF-α production, which may be closely associated with the blockage of NF-κB activation in macrophages.

Analysis of Forensic Autopsy in 120 Cases of Medical Disputes Among Different Levels of Institutional Settings.

Despite advances in medical science, the causes of death can sometimes only be determined by pathologists after a complete autopsy. Few studies have investigated the importance of forensic autopsy in medically disputed cases among different levels of institutional settings. Our study aimed to analyze forensic autopsy in 120 cases of medical disputes among five levels of institutional settings between 2001 and 2012 in Wenzhou, China. The results showed an overall concordance rate of 55%. Of the 39% of clinically missed diagnosis, cardiovascular pathology comprises 55.32%, while respiratory pathology accounts for the remaining 44. 68%. Factors that increase the likelihood of missed diagnoses were private clinics, community settings, and county hospitals. These results support that autopsy remains an important tool in establishing causes of death in medically disputed case, which may directly determine or exclude the fault of medical care and therefore in helping in resolving these cases.

The time-dependent expression of α7nAChR during skeletal muscle wound healing in rats.

The study on time-dependent expression of α7 nicotine acetylcholine receptor (α7nAChR) was performed by immunohistochemistry, Western blotting, and real-time PCR during skeletal muscle wound healing in rats. Furthermore, co-localization of α7nAChR with macrophage or myofibroblast marker was detected by double immunofluorescence. A total of 50 Sprague-Dawley male rats were divided into control and contusion groups (3 h, 6 h, 12 h, 1 day, 3 days, 5 days, 7 days, 10 days, and 14 days post-injury). In the uninjured controls, α7nAChR positive staining was observed in the sarcolemma and sarcoplasm of normal myofibers. In wounded specimens, a small number of polymorphonuclear cells, a number of macrophages and myofibroblasts showed positive reaction for α7nAChR in contused zones. Morphometrically, the average ratios of α7nAChR-positive cells were over 50 % from 3 to 10 days after contusion, and exceeded 60 % at 5 and 7 days post-injury. Besides, the positive ratios of α7nAChR were <50 % at the other posttraumatic intervals. By Western blotting analysis, the average ratio of α7nAChR protein expression maximized at 7 days after injury, which was >2.13. Similarly, the relative quantity of α7nAChR mRNA expression peaked at 7 days post-wounding as compared with control by real-time PCR detection, showing a relative quantity of >2.65. In conclusion, the expression of α7nAChR is upregulated and temporally distributed in macrophages and myofibroblasts during skeletal muscle wound healing, which might be closely involved in inflammatory response and fibrotic repair after injury. Moreover, α7nAChR is promising as a useful marker for wound age determination of skeletal muscle.

[Comparative analysis between diatom nitric acid digestion method and plankton 16S rDNA PCR method].

OBJECTIVE: To compare and explore the application value of diatom nitric acid digestion method and plankton 16S rDNA PCR method for drowning identification. METHODS: Forty drowning cases from 2010 to 2011 were collected from Department of Forensic Medicine of Wenzhou Medical University. Samples including lung, kidney, liver and field water from each case were tested with diatom nitric acid digestion method and plankton 16S rDNA PCR method, respectively. The Diatom nitric acid digestion method and plankton 16S rDNA PCR method required 20 g and 2 g of each organ, and 15 mL and 1.5 mL of field water, respectively. The inspection time and detection rate were compared between the two methods. RESULTS: Diatom nitric acid digestion method mainly detected two species of diatoms, Centriae and Pennatae, while plankton 16S rDNA PCR method amplified a length of 162 bp band. The average inspection time of each case of the Diatom nitric acid digestion method was (95.30 +/- 2.78) min less than (325.33 +/- 14.18) min of plankton 16S rDNA PCR method (P < 0.05). The detection rates of two methods for field water and lung were both 100%. For liver and kidney, the detection rate of plankton 16S rDNA PCR method was both 80%, higher than 40% and 30% of diatom nitric acid digestion method (P < 0.05), respectively. CONCLUSION: The laboratory testing method needs to be appropriately selected according to the specific circumstances in the forensic appraisal of drowning. Compared with diatom nitric acid digestion method, plankton 16S rDNA PCR method has practice values with such advantages as less quantity of samples, huge information and high specificity.

Time-dependent expression and distribution of Egr-1 during skeletal muscle wound healing in rats.

Recent studies have shown that early growth response factor-1 (Egr-1) plays an important role in regulation of inflammation and tissue repair, but little is known about its expression after trauma to skeletal muscles. A preliminary study on time-dependent expression and distribution of Egr-1 was performed by immunohistochemistry, immunofluorescence and Western blotting during skeletal muscle wound healing in rats. An animal model of skeletal muscle contusion was established in 45 Sprague-Dawley male rats. Samples were taken at 6 h, 12 h, 1 day, 3 days, 5 days, 7 days, 10 days, 14 days and 21 days post-injury, respectively (5 rats in each posttraumatic interval). 5 rats were employed as control. In the uninjured controls, Egr-1 positive staining was observed in the sarcoplasm and nuclei of normal myofibers. In wounded specimens, a small number of polymorphonuclear cells (PMNs), a number of mononuclear cells (MNCs), fibroblastic cells (FBCs) and regenerated multinucleated myotubes showed positive reaction for Egr-1 in contused zones. By morphometric analysis, an increase in Egr-1 expression was verified at inflammatory phase after contusion, which reached a peak in the regenerated phase overlapping with the fibrotic phase during skeletal muscle wound healing. The expression tendency was further confirmed by Western blotting assay. By immunofluorescent staining for co-localization, the Egr-1-positive MNCs and FBCs in wounds were identified as macrophages and myofibroblasts. The results demonstrate that the expression of Egr-1 is up-regulated and temporally distributed in certain cell types after trauma to skeletal muscles, which may be closely involved in inflammatory response, fibrotic repair and muscle regeneration during skeletal muscle wound healing.

Association between pri-miR-218 polymorphism and risk of hepatocellular carcinoma in a Han Chinese population.

MicroRNAs are noncoding RNA molecules of 18-25 nucleotides that regulate gene expression at the post-transcriptional level. The aim of this study was to investigate whether pri-miR-218 rs11134527 A/G polymorphism influences the risk of hepatocellular carcinoma (HCC) or not. pri-miR-218 rs11134527 A/G was genotyped in 302 HCC patients and 513 control subjects using the polymerase chain reaction-restriction fragment length polymorphism assay. The AG genotype of pri-miR-218 rs11134527 A/G was associated with family history (p=0.018, odds ratio [OR]=2.96, 95% confidence interval [CI]: 1.16-7.56) and elevated serum α-fetoprotein (serum alpha-fetoprotein [AFP]) levels (≥20 ng/mL; p=0.009, OR=1.92, 95% CI: 1.17-3.14) in HCC patients. These findings suggested that the AG genotype of pri-miR-218 rs11134527 might relate to genetic predisposition and be involved in regulating the expression of AFP in Chinese HCC patients.

[The expression of BDNF and PSD-95 in hippocampal CA1 region of morphine-withdrawn rat with different dependent times].

OBJECTIVE: To observe the expression of brain-derived neurotrophic factor (BDNF) and postsynaptic density-95 (PSD-95) in hippocampal CA1 region of rat with morphine dependence for different times and withdrawn for 1 week, and investigate the influence of that morphine dependence is withdrawn on rat hippocampal CA1 area. METHODS: Animal models of rats with morphine withdrawal for 1 week and different morphine dependent times(1 week, 2 weeks, 4 weeks) were established. The expression of BDNF and PSD-95 in hippocampal CA1 were identified with RT-PCR. RESULTS: The expression of BDNF and PSD-95 in hippocampal CA1 decreased in the withdrawn group with morphine dependence for 1 week as compared with that in normal saline (NS) group (P < 0.01), and it increased in the withdrawn group with morphine dependence for 2 weeks as compared with that in morphine-dependent group for 1 week (P < 0.05) but still decreased as compared with that in NS group (P < 0.01), and it decreased in the withdrawn group with morphine dependence for 4 weeks as compared with the other three groups (P < 0.01). CONCLUSION: The expression of BDNF and PSD-95 in hippocampal CA1 decreases in morphine-depended rats withdrawn for 1 week. Morphine withdrawal has a manifest harm in hippocampal CA1 region of rat.

[Acute necrotizing pancreatitis and postmortem autolysis of pancreas].

OBJECTIVE: To compare the pathomorphologic changes between the pancreas in acute necrotizing pancreatitis (ANP) and that in acute deaths of rats (within 48 hours) so as to find the distinctions. METHODS: The animal models of ANP and other acute deaths (electroshock, mechanic asphyxia/strangle, and acute poisoning with tetramine) were established according to the criteria. Half-quantitative grading and image quantitative analysis methods were employed to observe the gross and microscopic changes of the pancreases. RESULTS: Three features including inflammation infiltrate, fat necrosis and calcium deposit in the ANP group were considerably different from that in other acutely died rat group (P<0.05). CONCLUSION: Inflammation infiltrate, fat necrosis and calcium deposit are the most important pathologic features found in ANP by common light microscope, distinguishing ANP from postmortem pancreatic autolysis.

[Genetic polymorphisms of three loci and implication to forensic medicine].

OBJECTIVE: To obtain population genetic data of short tandem repeat (STR) locus D2S1327, D1S1390, and D11S2008 and to investigate the disparity of allelic frequency distributions among populations from different regions. METHODS: Blood samples of 300 unrelated individuals from Chengdu (Han), Bangkok (Thai) and Maint (Germany) were taken and analyzed with single PCR, polyacrylamide gel electrophoresis and silver staining. RESULTS: In the three loci, 9, 6, and 8 alleles and 32,14, and 22 genotypes were found respectively. The observed heterozygosity of 79%-82%, 63.0%-74.3%, and 72.0%-74.3% and discrimination power of 87.8%-92.6%, 79.6%-82.5%, and 87.6%-89.0% were identified for the three loci respectively. The genotype distributions of the three loci in the three populations fitted well with Hardy-Weinberg equilibrium. There was no significant difference in allelic frequency distributions among the three populations. CONCLUSION: The methods described in this paper are easy to perform and have high sensitivities. The discrimination power and exclusion chances of these three loci are desirable for forensic analysis and application.

[Primary study on the influence of blood transfusion on the STR genotypes of recipient's blood].

OBJECTIVE: To investigate whether any change occurred in recipients' blood collected at different times after transfusion with different quantity of blood. METHODS: Three patients were transfused with 400 ml, 800 ml and 1200 ml blood separately. The blood samples were collected from the recipients before transfusion and at 4 h, 8 h, 12 h after transfusion, and from the donors. DNA were extracted by Chelex-100 method and were amplified by the polymerase chain reaction (PCR). Six loci of D1S549, D18S865, D3S1754, D12S391, D12S375, D6S477 were selected. The PCR products were analyzed by polyacrylamide gel (PAG) vertical electrophoresis and silver staining. RESULTS: The investigations on the six STR loci revealed that the patients' STR genotypes remained unchanged within 12 h after blood transfusion. CONCLUSION: The STR genotypes of the donors would have no influence on the STR genotypes of the patients within 12 h after transfusion providing the volume of blood transfused is less than 1200 ml.