Effects of orientation and distance of goats on blast lung injury characteristics on a plateau above 4500-meter.

PURPOSE: High explosives are used to produce blast waves to study their biological effects. The lungs are considered as the critical target organ in blast-effect studies. The degree of lung hemorrhaging is related to both the explosive power and the increased lung weight. We studied the characteristics of the biological effects from an air explosion of a thermobaric bomb in a high-altitude environment and the lethality and lung injury severity of goats in different orientations and distances. METHODS: Goats were placed at 2.5, 3, 4, and 5 m from the explosion center and exposed them to an air blast at an altitude of 4700-meter. A group of them standing oriented to the right side and the other group seated facing the explosion center vertically. The lung injuries were quantified according to the percentage of surface area contused, and using the pathologic severity scale of lung blast injury (PSSLBI) to score the 4 injury categories (slight, moderate, serious and severe) as 1, 2, 3, and 4, respectively. The lung coefficient (lung weight [g]/body weight [kg]) was the indicator of pulmonary edema and was related to lung injury severity. Blast overpressure data were collected using blast test devices placed at matching locations to represent loadings to goats. All statistical analyses were performed using SPSS, version 26.0, statistical software (SPSS, Inc., Chicago, IL, USA). RESULTS: In total, 127 goats were involved in this study. Right-side-standing goats had a significantly higher mortality rate than those seated vertical-facing (p < 0.05). At the 2.5 m distance, the goat mortality was nearly 100%, whereas at 5 m, all the goats survived. Lung injuries of the right-side-standing goats were 1 - 2 grades more serious than those of seated goats at the same distances, the scores of PSSLBI were significantly higher than the seated vertical-facing goats (p < 0.05). The lung coefficient of the right-side-standing goats were significantly higher than those of seated vertical-facing (p < 0.05). Mortality, PSSLBI, and the lung coefficient results indicated that the right-side-standing goats experienced severer injuries than the seated vertical-facing goats, and the injuries were lessened as the distance increased. The blast overpressure was consistent with these results. CONCLUSION: The main killing factors of the thermobaric bomb in the high-altitude environment were blast overpressure, blast wind propulsions and burn. The orientation and distances of the goats significantly affected the blast injury severity. These results may provide a research basis for diagnosing, treating and protecting against injuries from thermobaric explosions.

An open air research study of blast-induced traumatic brain injury to goats.

PURPOSE: We once reported blast-induced traumatic brain injury (bTBI) in confined space. Here, bTBI was studied again on goats in the open air using 3.0 kg trinitrotoluene. METHODS: The goats were placed at 2, 4, 6 and 8 m far from explosion center. Trinitrotoluene (TNT) was used as the source of the blast wave and the pressure at each distance was recorded. The systemic physiology, electroencephalogram, serum level of S-100 beta, and neuron specific enolase (NSE) were determined pre and post the exposure. Neuroanatomy and neuropathology were observed 4 h after the exposure. RESULTS: Simple blast waveforms were recorded with parameters of 702.8 kPa-0.442 ms, 148.4 kPa-2.503 ms, 73.9 kPa-3.233 ms, and 41.9 kPa-5.898 ms at 2, 4, 6 and 8 m respectively. Encephalic blast overpressure was on the first time recorded in the literature by us at 104.2 kPa-0.60 ms at 2 m, where mortality and burn rate were 44% and 44%. Gross examination showed that bTBI was mainly manifested as congestive expansion of blood vessels and subarachnoid hemorrhage, which had a total incidence of 25% and 19% in 36 goats. Microscopical observation found that the main pathohistological changes were enlarged perivascular space (21/36, 58%), small hemorrhages (9/36, 25%), vascular dilatation and congestion (8/36, 22%), and less subarachnoid hemorrhage (2/36, 6%). After explosion, serum levels of S-100b and NSE were elevated, and EEG changed into slow frequency with declined amplitude. The results indicated that severity and incidence of bTBI is related to the intensity of blast overpressure. CONCLUSION: Blast wave can pass through the skull to directly injure brain tissue.

Morphological study of Schwann cells remyelination in contused spinal cord of rats.

OBJECTIVE: To study the role and effect of Schwann cells (SCs) remyelination in contused spinal cord. METHODS: Green fluorescence protein expressing-SCs were transplanted into the epicenter, rostral and caudal tissues of the injury site at 1 week after the spinal cords were contused. At 6 weeks, the spinal cords were removed for cryosections, semithin sections and ultrathin sections, and then immunocytochemical staining of myelin basic protein (MBP), P0 protein (P0) and S100 protein (S100) was carried out on the cryosections. Qualitative and semiquantitative analyses were performed on the cryosections and semithin sections. Ultrastructure of myelinated fibers was observed on the ultrathin sections under electron microscope. RESULTS: Transplanted SCs and myelinated fibers immunocytochemically labeled by MBP, P0 as well as S100 distributed in whole injured area. The quantity of myelinated fibers labeled by the three myelin proteins showed no statistical difference, however, which was significantly larger than that of controls. On the semithin sections, the experimental group demonstrated more myelinated fibers in the injured area than the controls, but the fibers had smaller diameter and thinner myelin sheath under electron microscope. CONCLUSION: SCs can promote regeneration of injured nerve fibers and enhance remyelination, which may be histological basis of SCs-mediated functional repair of injured spinal cords.

Tumor necrosis factor alpha gene polymorphism is associated with the outcome of trauma patients in Chinese Han population.

BACKGROUND: Tumor necrosis factor (TNF) is a proinflammatory cytokine that plays a major role in the sepsis and multiple organ dysfunction secondary to major trauma. The purpose of this article was to research the clinical relevance of the TNF gene polymorphism in patients with major trauma. METHODS: Three hundred six patients with major trauma were prospectively recruited. The TNF gene polymorphisms were genotyped using restriction fragment length polymorphism analysis. Plasma TNF-α levels were determined with enzyme-linked immunosorbent assay. Sepsis morbidity rate and multiple organ dysfunction scores were accessed. RESULTS: The TNF-α/-308 polymorphism was shown to be well associated with increased capacity of peripheral leukocytes to produce TNF-α in response to ex vivo lipopolysaccharide stimulation in trauma patients at admission. Results from association study indicated that trauma patients carrying the TNF-α/-308/A allele were more likely complicated with sepsis. CONCLUSIONS: The TNF-α/-308 polymorphism might be used as a biomarker for the assessment of outcome of trauma patients, but the TNF-ß/252 gene polymorphism might not influence the development of complications in patients with major trauma.

Functional significance of the Toll-like receptor 4 promoter gene polymorphisms in the Chinese Han population.

OBJECTIVE: Toll-like receptor 4 is an important signaling receptor for lipopolysaccharide in mammals, and the variation of the promoter may affect the activity of toll-like receptor 4 expression. Although 12 single nucleotide polymorphisms have been identified in the toll-like receptor 4 promoter, little is known about the functional significance of these single nucleotide polymorphisms. DESIGN: Genetic functional and association studies. SETTING: National Key Laboratory of Trauma and Departments of Traumatic Surgery in two teaching hospitals. SUBJECTS: Three hundred seventy-nine healthy volunteers and 303 patients with major trauma. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Five single nucleotide polymorphisms identified in the toll-like receptor 4 promoter in the Chinese Han population were selected. Three of them revealed a close relationship with transcription factor binding sites. Among the three single nucleotide polymorphisms, only the T-2242C polymorphism significantly increased transcriptional activities of the toll-like receptor 4 promoter, as shown by reporter gene assay. Results from flow cytometry and ex vivo responsiveness of peripheral blood leukocytes indicated that the T-2242C polymorphism was well-associated with increased expression of toll-like receptor 4 protein and production of tumor necrosis factor-alpha. The clinical relevance of these single nucleotide polymorphisms was then investigated in 303 patients with major trauma. The peripheral blood leukocytes of trauma patients with the variant C allele revealed greater capacity to produce tumor necrosis factor-alpha and interleukin-6 on the admission day. Furthermore, the toll-like receptor 4/2242 polymorphism was significantly associated with higher sepsis morbidity rates and multiple organ dysfunction scores in patients with major trauma. CONCLUSIONS: The toll-like receptor 4/2242 polymorphism is a functional variant and might be used as a relevant risk estimate for organ dysfunction and sepsis in trauma patients.

Bleomycin induces epithelial-to-mesenchymal transition via bFGF/PI3K/ESRP1 signaling in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a fatal and chronic disease with a high rate of infection and mortality; however, its etiology and pathogenesis remain unclear. Studies have revealed that epithelial-mesenchymal transition (EMT) is a crucial cellular event in IPF. Here, we identified that the pulmonary fibrosis inducer bleomycin simultaneously increased the expression of bFGF and TGF-ß1 and inhibited epithelial-specific regulatory protein (ESRP1) expression in vivo and in vitro. In addition, in vitro experiments showed that bFGF and TGF-ß1 down-regulated the expression of ESRP1 and that silencing ESRP1 promoted EMT in A549 cells. Notably, we determined that bFGF activates PI3K/Akt signaling, and treatment with the PI3K/Akt inhibitor LY294002 inhibited bleomycin-induced cell morphology changes and EMT. In addition, the effects of LY294002 on bleomycin-induced EMT were inhibited by ESRP1 silencing in A549 cells. Taken together, these findings suggest that bleomycin induced EMT through down-regulating ESRP1 by simultaneously increasing bFGF and TGF-ß1 in pulmonary fibrosis. Additionally, our findings indicated that bFGF inhibits ESRP1 by activating PI3K/Akt signaling.

Bleomycin-enhanced alternative splicing of fibroblast growth factor receptor 2 induces epithelial to mesenchymal transition in lung fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an important public health problem, and it has few treatment options given its poorly understood etiology; however, epithelial to mesenchymal transition (EMT) of pneumocytes has been implicated as a factor. Herein, we aimed to explore the underlying mechanisms of lung fibrosis mediated by EMT, with a focus on the alternative splicing of fibroblast growth factor receptor 2 (FGFR2), using bleomycin (BLM)-induced lung fibrotic and transgenic mouse models. We employed BLM-induced and surfactant protein C (SPC)-Cre and LacZ double transgenic mouse models. The results showed that EMT occurred during lung fibrosis. BLM inhibited the expression of epithelial splicing regulatory protein 1 (ESRP1), resulting in enhanced alternative splicing of FGFR2 to the mesenchymal isoform IIIc. BLM-induced lung fibrosis was also associated with the activation of TGF-ß/Smad signaling. These findings have implications for rationally targetted strategies to therapeutically address IPF.

Functional significance of the TLR4/11367 polymorphism identified in Chinese Han population.

Toll-like receptor 4 (TLR4) is the central signaling receptor for lipopolysaccharide (LPS) in mammals. This study was designed to investigate the functional significance of the G11367C polymorphism, which is a novel variant we identified in the 3' untranslated region of TLR4 gene in Chinese Han population. Three hundred seventy healthy volunteers were selected. The TLR4/11367 polymorphism was genotyped using single-tube bidirectional allele-specific amplification method. The TLR4 protein expression on peripheral leukocytes and plasma tumor necrosis factor alpha levels were determined by means of flow cytometry and enzyme-linked immunosorbent assay. The post-transcriptional effect of the 11367 polymorphism was evaluated by means of reporter gene assay and real-time quantitative polymerase chain reaction. The G11367C polymorphism is a common allele in Chinese Han population, with minor allele frequency of 14.7%. In response to ex vivo LPS stimulation, the TLR4 expression on the surface of peripheral leukocytes and the plasma tumor necrosis factor alpha levels were significantly lower in carriers of 11367C variant allele than in carriers of 11367G allele. This association was allele dose dependent. We also found that the activity and the mRNA expression of luciferase was significantly smaller in human embryonic kidney 293 cells transfected with construct containing 11367C allele than in those transfected with construct containing 11367G allele. Together, these results suggest that the TLR4/11367 polymorphism may be a functional single nucleotide polymorphism, which could attenuate the LPS-induced transmembrane signaling through the alteration of post-transcriptional regulation of 3' untranslated region and target gene expression.

Bleomycin (BLM) Induces Epithelial-to-Mesenchymal Transition in Cultured A549 Cells via the TGF-ß/Smad Signaling Pathway.

The epithelial-to-mesenchymal transition (EMT) is a crucial cellular event in wound healing, tissue repair, and cancer progression in adult tissues, with the interactions with numerous signals. In this study, we aimed to determine whether bleomycin (BLM), an agent that causes pulmonary fibrosis, induces the EMT of the alveolar epithelial cell line A549 and investigated the possible mechanisms. We examined the EMT involved changes in cell morphology, isoform switching of the fibroblast growth factor receptor 2 (FGFR2) by alternative splicing, and expression of the phenotypic markers including E-cadherin, vimentin, and α-SMA using RT-PCR, Western blotting, and immunofluorescence assays. A TGF-ß/Smad inhibitor was used to determine whether coculture with BLM would inhibit the EMT of A549 cells. The results showed that BLM induced the EMT of A549 cells possibly via the TGF-ß/Smad signaling pathway, evident from the decrease in the expression of E-cadherin and increase in the expression on vimentin.

Clinical relevance of the glucocorticoid receptor gene polymorphisms in glucocorticoid-induced ocular hypertension and primary open angle glaucoma.

AIM: To avoid the side effects of ocular hypertension of glucocorticoid (GC) usage in eye, we must identify susceptible individuals, which exists in about one-third of all population. Further, the majority of all primary open angle glaucoma (POAG) patients show this phenotype. Glucocorticoid receptor (GR) regulates C responsiveness in trabecular meshwork (TM) cells. In this study, single nucleotide polymorphism (SNP) genotyping was used to determine whether there are differences in the BclI (rs41423247) and N363S (rs6195) polymorphisms of the GR gene in healthy and POAG patients, and glucocorticoid-induced ocular hypertension (GIOH) populations. METHODS: Three hundred and twenty-seven unrelated Chinese adults, including 111 normal controls, 117 GIOH subjects and 99 POAG patients, were recruited. DNA samples were prepared and the BclI and N363S polymorphisms were screened using real-time polymerase chain reaction (RT-PCR)-restriction fragment length polymorphism (RFLP) analysis. Frequencies of the BclI and N363S polymorphisms were determined and compared using Fisher's exact test and the Chi-squared test. RESULTS: Only the BclI polymorphism was identified in the Chinese Han population. The frequency of the G allele was 21.6 % in normal controls, 18.3% in GIOH patients, and 13.64% in the POAG patients. There was no significant difference in polymorphism or allele frequency in the 3 groups. Furthermore, no N363S polymorphism was found in the study subjects. CONCLUSION: The BclI polymorphisms in GR gene had no association with GIOH and POAG patients, and N363S polymorphism might not exist in the Chinese Han population. Therefore, the BclI polymorphism might not be responsible for the development of GC-induced ocular hypertension or POAG.

Clinical relevance of tag single nucleotide polymorphisms within the CAT gene in patients with PTSD in the Chongqing Han population.

BACKGROUND: Free radical-induced oxidative damage of the brain has been implicated in a number of psychiatric disorders, including post-traumatic stress disorder (PTSD). Catalase (CAT) is a major antioxidant enzyme and a number of polymorphisms in CAT have been shown to be associated with several diseases, including hypertension, diabetes mellitus, Alzheimer's disease, and vitiligo. The aim of this study was to evaluate the association of CAT gene polymorphisms with PTSD in a case-control study. MATERIALS AND METHODS: A total of 460 unrelated adult Chinese Han adults, including 287 healthy volunteers and 173 patients with PTSD. Six tag single-nucleotide polymorphisms (tSNPs) were selected from the entire CAT gene through construction of haplotype bins, and they were genotyped using an improved multiplex ligation detection reaction (iMLDR) technique. Allelic frequencies and clinical characteristics were compared in two independent Chinese Han populations. RESULTS: Six tag SNPs were identified in the Chinese Han population and all were common SNPs. However, we could detect no evidence of genetic association between six tag SNPs in the CAT gene and PTSD in the Chinese Han population. CONCLUSIONS: This result suggests that six tag SNPs of the CAT gene may not be associated with PTSD, and that CAT gene might not influence the development of PTSD in patients following exposure to a traumatic event, also may be the sample sizes too small to allow a meaningful test.

Genetic distribution and association analysis of DRD2 gene polymorphisms with major depressive disorder in the Chinese Han population.

Dopamine D2 receptor is involved in reward-mediating mesocorticolimbic pathways. It plays an important role in major depressive disorder (MDD). Three gene polymorphisms Taq1A, C957T and -141C ins/del, were identified in the DRD2 gene among the Western population. These variants in the DRD2 gene might be associated with the susceptibility of MDD patients through affecting the bioeffects of endogenous dopamine neurotransmission. However, little is known about their occurrence in Chinese population and their association with the susceptibility of patients with major depressive disorder. In this study, a total of 338 unrelated adult Chinese Han population, including 224 healthy volunteers and 114 patients with major depressive disorder, were recruited. DRD2 polymorphisms (Taq1A and -141C ins/del) were detected using restriction fragment length polymorphism (RFLP) analysis and the C957T were detected by sequencing directly. As a result, three polymorphisms were identified in Chinese Han population and all were common SNP. However, we could detect no evidence of genetic association between 3 markers in DRD2 and major depressive disorder in the Chinese Han population. To conclude, this result suggests that Taq1A, C957T and -141C ins/del of DRD2 gene may not be associated with major depressive disorder, also may be the sample sizes too small to allow a meaningful test.

Differing Schwann cells and olfactory ensheathing cells behaviors, from interacting with astrocyte, produce similar improvements in contused rat spinal cord's motor function.

In recent years, cell behaviors of Schwann cells (SCs) and olfactory ensheathing cells (OECs) when interacting with astrocytes was appraised qualitatively in vitro and in spinal cord injury model of dorsal crush and transection and in normal white matter. In this study, with an attempt to select a candidate for cell-mediated repair of the spinal cord injury, SCs or OECs were transplanted into contused spinal cord in adult rats. The interaction with host astrocytes was assessed at 3 and 6 weeks after transplantation under light and electron microscope. The motor function of the rat was appraised with the BBB locomotor rating scale and cortical somatosensory evoked potentials (CSEP) recording. Within SCs cord, the astrocytes underwent proliferation and hypertrophy. The myelinated axons were separated into the groups by the glial membrane. Within OECs cord, astrocytes did not undergo the proliferation and hypertrophy. The myelinated axons were not divided into groups by the scar tissue. SCs graft, compared with OECs graft, induced more enhanced glial fibrillary acidic protein (GFAP) immunoreactivity with a distinct astroglial border between the normal and injured tissues. The distribution of SCs was more concentrated and less migrated than that of OECs. SCs induced weaker NF immunoreactivity and functional recovery compared to OECs, but no significant differences between the two groups was revealed by the statistical analysis. As we know, this is first time to compare behaviors of SCs and OECs in the contusion model, and the data indicates that although in vivo cell behaviors of SCs and OECs are different in interacting with astrocyte, both cell types can improve the motor function of the contused rats.

Distributions of glucocorticoid receptor gene polymorphisms in a Chinese Han population and associations with outcome after major trauma.

AIM: To investigate in a Chinese population the occurrence of polymorphisms Bcl I, N363S and ER22/23EK in the glucocorticoid receptor and their association with outcome of trauma. METHODS: In all, 266 healthy volunteers and 95 victims of major trauma were recruited. The presence of glucocorticoid receptor polymorphisms (ER22/23EK, N363S and Bcl I) was sought by restriction fragment length polymorphism analysis. The injured group were monitored as to respiratory, renal, hepatic, cardiovascular, haematological and central nervous functions. The association was determined between polymorphisms and the development of multiple organ dysfunction syndrome and sepsis after trauma. RESULTS: Only the Bcl I polymorphism was identified. The frequency of its G allele was 23.5% among volunteers and 26.3% among casualties. There were no significant differences in MOD score or sepsis rate between participants classified according to genotype. CONCLUSIONS: Only the Bcl I polymorphism of the glucocorticoid receptor gene is common in the Chinese Han population; it may not influence the development of complications following major trauma.

Clinical relevance of the TLR4 11367 polymorphism in patients with major trauma.

OBJECTIVE: To investigate the clinical relevance of the TLR4 11367 polymorphism in patients with major trauma. DESIGN: Genetic functional and association study. SETTING: Daping Hospital and Chongqing Emergency Medical Center, Chongqing, China. PATIENTS: A total of 132 patients with major trauma were prospectively recruited. MAIN OUTCOME MEASURES: The TLR4 11367 polymorphism was genotyped using single-tube, bidirectional, allele-specific amplification method. Whole peripheral blood samples obtained within 24 hours after admission were stimulated with lipopolysaccharide and then tested for production of tumor necrosis factor alpha and interleukin 6. Sepsis morbidity rate and multiple organ dysfunction scores were assessed. RESULTS: The 11367 polymorphism was shown to be strongly associated with less capacity of peripheral leukocytes to produce tumor necrosis factor alpha and interleukin 6 in response to ex vivo lipopolysaccharide stimulation in patients with trauma at admission. Results from association study indicated that patients with trauma who carry the 11367C allele were less likely to have sepsis and multiple organ dysfunction. CONCLUSIONS: Combined with our previous in vitro functional study, the results suggest that the TLR4 11367 polymorphism might be a good predictor of who is more likely to develop complications such as sepsis or multiple organ dysfunction syndrome, depending on genotype.