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.

Mixed l1/l- fault detection observer design for delayed 2D positive systems in FM LSS Models.

This study is concerned with the problem of the mixed l1/l- fault detection (FD) observer for delayed two-dimensional (2D) positive systems (PSs). The necessary and sufficient conditions (NSCs) are derived under which the residual error system is asymptotically stable (AS) and has the prescribed performance level. The conservatism is greatly reduced compared to the existing results. A new performance analysis method and the mixed l1/l- FD observer design are presented. Firstly, the calculation of l1/l- index for delayed 2D PSs is proposed by establishing the equivalence between the delayed system and the higher dimensional delay-free system in sense of l1 and l- indexes. Secondly, NSCs are developed such that the delayed 2D PS is AS with a desired mixed l1/l- performance. Thirdly, the sufficient conditions of the observer design are further developed based on linear programming. An iterative algorithm is formulated to minimize and maximize the impact of system disturbances and faults on the output signal, respectively. Finally, we present two examples to verify the superiority of the obtained results.

Nanoscale Porphyrin Metal-Organic Frameworks Deliver siRNA for Alleviating Early Pulmonary Fibrosis in Acute Lung Injury.

Acute lung injury (ALI) has high mortality and still lacks novel and efficient therapies. Zinc finger E-box binding homeobox 1 and 2 (ZEB1/2) are highly expressed in the early stage of ALI and are positively correlated with the progression of pulmonary fibrosis. Herein, we developed a nanoscale Zr(IV)-based porphyrin metal-organic (ZPM) framework to deliver small interfering ZEB1/2 (siZEB1/2) to alleviate early pulmonary fibrosis during ALI. This pH-responsive nano-ZPM system could effectively protect siRNAs during lung delivery until after internalization and rapidly trigger siRNA release under the mildly acidic environment of the endo/lysosome (pH 4.0-6.5) for transfection and gene silencing. Furthermore, the in vivo studies confirmed that this nano-ZPM system could anchor in inflamed lungs. Moreover, the ZEB1/2 silencing led to increased E-cadherin and decreased α-SMA levels. Overall, the nano-ZPM system was an excellent non-viral vector system to deliver siRNAs to alleviate early pulmonary fibrosis during ALI.

Global analysis of the COVID-19 research landscape and scientific impact.

OBJECTIVES: To consider a 1-year time window of the coronavirus disease 2019 (COVID-19) crisis to integrate qualitative and quantitative data and provide an in-depth analysis of all COVID-19 publications from geographical, epidemiological and chronological perspectives. METHODS: Publications on COVID-19 from December 1, 2019, to December 31, 2020 without document type limitations were extracted from the Web of Science database. Microsoft Excel 2016, GraphPad Prism 9, VOSviewer 1.6.15 and IBM SPSS 21.0 were used to analyze the global epidemiological publication landscape and its correlations, research hotspots around the world and the top 5 countries in terms of publications. RESULTS: A total of 51,317 documents were analyzed in the present study. The publication trend could be divided into an increasing output stage and an explosive output stage. There were positive correlations between monthly publications, confirmed cases and deaths. Research hotspots from the whole year, from individual quarters, and from the top 5 countries with the most publications were further identified. CONCLUSIONS: The correlation analysis of publications indicated that confirmed cases and deaths were forces driving the scientific output, reflecting the growing trend to some extent. Moreover, the hotspot analysis provided valuable information for scientists, funders, policy and decision-makers to determine what areas should be their focus when faced with public health emergencies in the future.

The effects of the M2a macrophage-induced axonal regeneration of neurons by arginase 1.

BACKGROUND: Spinal cord injury (SCI) is a challenge worldwide, but there are no effective treatments or therapeutic methods in the clinic. Recent studies have shown that type I arginase (Arginase1, Arg1) is closely associated with the treatment of SCI. The classical treatment for SCI involves filling the local area of SCI with activated M2a macrophages to allow the repair and regeneration of some synapses, but the specific mechanism of action of Arg1 is not clear. METHOD: In the present study, we first induced the polarization of RAW264.7 macrophages to M2a-type cells using IL-4 and constructed an Arg1 knockout cell line through the use of shRNA; we used these cells to treat a rat model of SCI. Finally, the present study explored the mechanism and pathway by which Arginase 1 regulates spinal repair by immunoblotting and immunohistochemistry. RESULT: Suspended M2a (Arg1-/+) macrophages were transplanted into the injury site in a rat model of contusion SCI. Compared with the model group and the shArg1 group, the shScramble (shSc) group exhibited higher Basso, Beattie, Bresnahan motor function scores, more compact structures and more Nissl bodies. Immunohistochemical results showed that the shSc group expressed higher levels of NeuN (a neuronal marker) and tau (an axonal marker), as well as the up-regulation of Cdc42, N-WASP, Arp2/3 and tau, as determined by Western blot. CONCLUSION: The study found that the polarization of M2a macrophages promoted the expression of Arginase 1, which restored axonal regeneration, promoted axonal regeneration, and promoted the structural and functional recovery of the contused spinal cord.

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.

Functional tag SNPs inside the DRD2 gene as a genetic risk factor for major depressive disorder in the Chinese Han population.

BACKGROUND: The D2 dopamine receptor (DRD2) has been extensively investigated and has been associated with the occurrence of neuropsychiatric disorders. Polymorphisms in the DRD2 gene have also been determined as a possible predisposing component for major depressive disorders (MDD). The present study focused on evaluating the connection of polymorphisms inside the whole DRD2 gene in MDD patients as well as in non-MDD participants in a group selected from the Chinese Han population. MATERIALS AND METHODS: In total, 831 unrelated Chinese adults from the Han population were sampled, including 497 non-MDD participants and 334 MDD patients for this evaluation. After the haplotype bins were built, 14 tag single-nucleotide polymorphisms (tSNPs) and the two most investigated SNP were chosen for the whole DRD2 gene. An improved multiplex ligation detection reaction (iMLDR) technique was used to choose the genotypes. Following this, the allelic frequencies and clinical features were contrasted between the two independent Chinese Han populations. Transcriptional enhancer activities were measured to assess the functionality of the rs7131056 polymorphism. RESULTS: Sixteen SNPs were identified, including the two most examined in the Chinese Han population, and all were recurrent SNPs. Of the 16 SNPs, two (rs4648317 and rs7131056) were significantly connected to MDD. Patients with MDD were more apt to carry the rs4648317G and rs7131056A allele in contrast to the non-MDD controls (P < 0.05). The genetic risk effect on MDD occurrence was associated with the haplotype GTGATCGCGCAGGC of fourteen tag SNPs (OR = 1.52, 95% CI: 1.06 to 2.18, P = 0.02). Moreover, the rs7131056 polymorphism contained intronic silencer activities. CONCLUSIONS: This case-control evaluation involving the Chinese Han population suggests that the rs4648317 and rs7131056 polymorphisms and the haplotype GTGATCGCGCAGGC inside the DRD2 gene could be possible markers to forecast vulnerability to MDD.

Fault detection observer design for 2-D continuous nonlinear systems with finite frequency specifications.

This research studies the problem of fault detection observer design for two-dimensional (2-D) continuous-time nonlinear systems in Takagi-Sugeno (T-S) form. Finite frequency (FF) specifications are used to design the observers, which makes observer designing different from previously proposed 2-D detection observers. Faults and disturbances are considered to be dominated in two different FF domain intervals. Fault sensitivity and disturbance robustness are measured by two FF performance indices, respectively. The aim of this paper is to design fault detection observers such that the residual error system has the sensitivity to faults and the desired robustness to disturbances. Sufficient conditions for the existence of a desired fault detection fuzzy observer are established in terms of linear matrix inequalities (LMIs). Simulation results indicate that faults can be detected effectively using the proposed method.

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.

The Effects of Co-transplantation of Olfactory Ensheathing Cells and Schwann Cells on Local Inflammation Environment in the Contused Spinal Cord of Rats.

Inflammatory response following spinal cord injury (SCI) is important in regulation of the repair process. Olfactory ensheathing cells (OECs) and Schwann cells (SCs) are important donor cells for repairing SCI in different animal models. However, synergistic or complementary effects of co-transplantation of both cells for this purpose have not been extensively investigated. In the present study, we investigated the effects of co-transplantation of OECs and SCs on expression of pro- or anti-inflammatory factor and polarization of macrophages in the injured spinal cord of rats. Mixed cell suspensions containing OECs and SCs were transplanted into the injured site at 7 days after contusion at the vertebral T10 level. Compared with the DMEM, SC, or OEC group, the co-transplantation group had a more extensive distribution of the grafted cells and significantly reduced number of astrocytes, microglia/macrophage infiltration, and expression of chemokines (CCL2 and CCL3) at the injured site. The co-transplantation group also significantly increased arginase+/CD206+ macrophages (IL-4) and decreased iNOS+/CD16/32+ macrophages (IFN-γ), which was followed by higher IL-10 and IL-13 and lower IL-6 and TNF-α in their expression levels, a smaller cystic cavity area, and improved motor functions. These results indicate that OEC and SC co-transplantation could promote the shift of the macrophage phenotype from M(IFN-γ) to M(IL-4), reduce inflammatory cell infiltration in the injured site, and regulate inflammatory factors and chemokine expression, which provide a better immune environment for SCI repair.

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.

Assessment of functional tag single nucleotide polymorphisms within the DRD2 gene as risk factors for post-traumatic stress disorder in the Han Chinese population.

BACKGROUND: Gene variations related to the dopaminergic pathway have been implicated in a number of neuropsychiatric disorders, including post-traumatic stress disorder (PTSD). Dopamine D2 receptor (DRD2) has been shown to significantly contribute to neuropsychiatric disorders and may specifically contribute to predisposition to PTSD. This study aimed to evaluate the association of polymorphisms within the entire DRD2 gene with PTSD in a case-control study. MATERIALS AND METHODS: A total of 834 unrelated Han Chinese adults, including 497 healthy volunteers and 337 patients with PTSD, were used in this study. Fifteen tag single-nucleotide polymorphisms (tSNPs) were selected spanning the entire DRD2 gene through the construction of haplotype bins. Genotypes were gathered using an improved multiplex ligation detection reaction (iMLDR) technique. Allelic frequencies and clinical characteristics were compared in two independent Han Chinese populations. Moreover, the functionality of the rs2075652 and rs7131056 polymorphisms were assessed by measuring transcriptional enhancer activities. RESULTS: Fifteen tag SNPs were identified in the Han Chinese population and all were common SNPs. Among 15 tSNPs, two of them (rs2075652 and rs7131056) significantly associated with PTSD. PTSD individuals were more likely to carry the rs2075652A and rs7131056A allele compared to the controls (P<0.05). The haplotype GTGATCGCGCAGGCG, had a risk effect on PTSD occurrence (OR=1.75, 95% CI: 1.24-2.48, P=0.002). Additionally, the rs2075652 polymorphism contained intronic enhancer activities. CONCLUSIONS: The rs2075652 and rs7131056 polymorphisms, and the haplotype GTGATCGCGCAGGCG within the DRD2 gene, may be potential markers to predict susceptibility to PTSD.

Identification of functional tag single nucleotide polmorphisms within the entire CAT gene and their clinical relevance in patients with noise-induced hearing loss.

OBJECTIVES: Noise-induced hearing loss (NIHL) is an important occupational disease which results from an interaction between genetic and environmental factors. More and more evidences suggested that Catalase (CAT) gene polymorphism plays an important role in the development of NIHL. The aim of this study was to investigate the association of CAT gene polymorphisms with NIHL in a case-control study. DESIGN: A total of 719 unrelated adult Chinese Han population, including 225 healthy volunteers and 494 noise-exposed workers were recruited in this study. Six tag single-nucleotide polymorphisms (tSNPs) were genotyped using an improved multiplex ligation detection reaction technique. Subsequently, the interaction between noise exposure level and genotypes and their effect on NIHL were analyzed using logistic regression. RESULTS: Among six tSNPs, two of them (rs208679 and rs769217) were significantly associated with noise exposure level. For rs208679 recessive effect, GG genotype had a significantly increased of NIHL risk in the exposure level of <85 dB; and for rs769217 dominant effect, the combined genotypes TT/TC had a significantly increased of NIHL risk in the exposure level of 85 dB~92 dB; and the haplotype A-G-T-C-A-C had a risk effect on the NIHL in the exposure level of 85 dB~92 dB. In addition, the rs769217 polymorphism could enhance the transcription activities of the CAT gene. CONCLUSIONS: This study identified CAT is a NIHL susceptibility gene when noise exposure levels are taken into account. Rs208679 and rs769217 polymorphisms might be used as relevant risk estimates for the development of NIHL in population with different noise exposure levels.

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.

Synergic effects of EPI-NCSCs and OECs on the donor cells migration, the expression of neurotrophic factors, and locomotor recovery of contused spinal cord of rats.

Cell-based therapy is a promising strategy for the repair of spinal cord injury (SCI), and the synergic effects of donor cells are emphasized in recent years. In this study, epidermal neural crest stem cells (EPI-NCSCs) and olfactory ensheathing cells (OECs) were transplanted into the contused spinal cord of rats separately or jointly at 1 week after injury. At 3 and 9 weeks posttransplantation, migration of the donor cells, expression of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) and functional recovery of the contused cord were determined by techniques of histopathology, quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry and Basso-Beattie-Bresnahan (BBB) score. The results showed that the migration and distribution of EPI-NCSCs in vivo were promoted by OECs at 3 weeks after transplantation, but they vanished at 9 weeks. The expression of BDNF and GDNF was significantly increased by co-transplantation at molecular and protein level. Although the expression of both factors in EPI-NCSCs- and OECs-injected group was lower than in co-injected group, it was higher than in control groups. Similarly, the best locomotor recovery of the contused cord was acquired from co-injected animals. As we know, this is the first time to study the synergic effects of EPI-NCSCs and OECs, and the data indicates that donor cells migration, expression of neurotrophic factors (NTFs), and recovery of motor function can be improved by EPI-NCSCs and OECs synergistically.

Macrophages in spinal cord injury: phenotypic and functional change from exposure to myelin debris.

Macrophage activation and persistent inflammation contribute to the pathological process of spinal cord injury (SCI). It was reported that M2 macrophages were induced at 3-7 days after SCI but M2 markers were reduced or eliminated after 1 week. By contrast, M1 macrophage response is rapidly induced and then maintained at injured spinal cord. However, factors that modulate macrophage phenotype and function are poorly understood. We developed a model to distinguish bone-marrow derived macrophages (BMDMs) from residential microglia and explored how BMDMs change their phenotype and functions in response to the lesion-related factors in injured spinal cord. Infiltrating BMDMs expressing higher Mac-2 and lower CX3CR1 migrate to the epicenter of injury, while microglia expressing lower Mac-2 but higher CX3CR1 distribute to the edges of lesion. Myelin debris at the lesion site switches BMDMs from M2 phenotype towards M1-like phenotype. Myelin debris activates ATP-binding cassette transporter A1 (ABCA1) for cholesterol efflux in response to myelin debris loading in vitro. However, this homeostatic mechanism in injured site is overwhelmed, leading to the development of foamy macrophages and lipid plaque in the lesion site. The persistence of these cells indicates a pro-inflammatory environment, associated with enhanced neurotoxicity and impaired wound healing. These foamy macrophages have poor capacity to phagocytose apoptotic neutrophils resulting in uningested neutrophils releasing their toxic contents and further tissue damage. In conclusion, these data demonstrate for the first time that myelin debris generated in injured spinal cord modulates macrophage activation. Lipid accumulation following macrophage phenotype switch contributes to SCI pathology.

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.

Embryonic Stem Cells Promoting Macrophage Survival and Function are Crucial for Teratoma Development.

Stem cell therapies have had tremendous potential application for many diseases in recent years. However, the tumorigenic properties of stem cells restrict their potential clinical application; therefore, strategies for reducing the tumorigenic potential of stem cells must be established prior to transplantation. We have demonstrated that syngeneic transplantation of embryonic stem cells (ESCs) provokes an inflammatory response that involves the rapid recruitment of bone marrow-derived macrophages (BMDMs). ESCs are able to prevent mature macrophages from macrophage colony-stimulating factor (M-CSF) withdrawal-induced apoptosis, and thus prolong macrophage lifespan significantly by blocking various apoptotic pathways in an M-CSF-independent manner. ESCs express and secrete IL-34, which may be responsible for ESC-promoted macrophage survival. This anti-apoptotic effect of ESCs involves activation of extracellular signal-regulated kinase (ERK)1/2 and PI3K/Akt pathways and thus, inhibition of ERK1/2 and PI3K/AKT activation decreases ESC-induced macrophage survival. Functionally, ESC-treated macrophages also showed a higher level of phagocytic activity. ESCs further serve to polarize BMDMs into M2-like macrophages that exhibit most tumor-associated macrophage phenotypic and functional features. ESC-educated macrophages produce high levels of arginase-1, Tie-2, and TNF-α, which participate in angiogenesis and contribute to teratoma progression. Our study suggests that induction of M2-like macrophage activation is an important mechanism for teratoma development. Strategies targeting macrophages to inhibit teratoma development would increase the safety of ESC-based therapies, inasmuch as the depletion of macrophages completely inhibits ESC-induced angiogenesis and teratoma development.

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.

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.