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.

[Early efficacy analysis of minimally invasive Chevron-Akin osteotomy for the treatment of mild to moderate hallus valgus].

OBJECTIVE: To explore early efficacy of minimally invasive Chevron Akin(MICA) osteotomy for the treatment of mild to moderate hallux valgus. METHODS: From June 2019 to April 2021, a total of 26 patients (29 feet) with mild to moderate hallux valgus, including 1 male and 25 females aged from 19 to 78 years old with an average of(38.3±19.5) years old, were treated with MICA. Preoperative and postoperative hallux valgus angle(HVA), intermetatarsal angle(IMA) and shortening of the first metatarsal were observed and compared. American Orthopedic Foot and Ankle Society (AOFAS) forefoot scoring system and visual analogue scale (VAS) were applied to evaluate clinical outcome at the final follow-up, and complications were also recorded. RESULTS: All patients obtained followed up from 12 to 33 months with an average of(19.6±5.1) months. HVA and IMA was improved from (32.3±6.6)° and (11.7±3.2)° pre-operatively to (13.0±5.3)° and (6.1±3.2)° post-operatively, respectively, which had a significant difference (P<0.01). The average shortening of the first metatarsal was (2.7±1.1) mm. AOFAS and VAS was improved from (55.7±7.4) and (6.5±1.5) preoperatively and to (88.5±7.9) and (0.7±0.4) respectively at the final follow-up, which also had a significant difference(P<0.01). According to AOFAS score, 15 feet achieved an excellent result, 11 good and 3 moderate. CONCLUSION: MICA osteotomy is a safe and reliable surgical technique for mild to moderate hallux valgus with advantages of minimally invasive, rapid recovery, low complication rate and an effect improvement of hallux valgus deformity.

Immunomodulatory role of mesenchymal stem cells in Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common causes of dementia and is characterized by gradual loss in memory, language, and cognitive function. The hallmarks of AD include extracellular amyloid deposition, intracellular neuronal fiber entanglement, and neuronal loss. Despite strenuous efforts toward improvement of AD, there remains a lack of effective treatment and current pharmaceutical therapies only alleviate the symptoms for a short period of time. Interestingly, some progress has been achieved in treatment of AD based on mesenchymal stem cell (MSC) transplantation in recent years. MSC transplantation, as a rising therapy, is used as an intervention in AD, because of the enormous potential of MSCs, including differentiation potency, immunoregulatory function, and no immunological rejection. Although numerous strategies have focused on the use of MSCs to replace apoptotic or degenerating neurons, recent studies have implied that MSC-immunoregulation, which modulates the activity state of microglia or astrocytes and mediates neuroinflammation via several transcription factors (NFs) signaling pathways, may act as a major mechanism for the therapeutic efficacy of MSC and be responsible for some of the satisfactory results. In this review, we will focus on the role of MSC-immunoregulation in MSC-based therapy for AD.

Synergistic effects of dimethyloxallyl glycine and recombinant human bone morphogenetic protein-2 on repair of critical-sized bone defects in rats.

In bone remodeling, osteogenesis is closely coupled to angiogenesis. Bone tissue engineering using multifunctional bioactive materials is a promising technique which has the ability to simultaneously stimulate osteogenesis and angiogenesis for repair of bone defects. We developed mesoporous bioactive glass (MBG)-doped poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) composite scaffolds as delivery vehicle. Two bioactive molecules, dimethyloxalylglycine (DMOG), a small-molecule angiogenic drug, and recombinant human bone morphogenetic protein-2 (rhBMP-2), an osteoinductive growth factor, were co-incorporated into the scaffold. The synergistic effects of DMOG and rhBMP-2 released in the composite scaffolds on osteogenic and angiogenic differentiation of hBMSCs were investigated using real-time quantitative polymerase chain reaction and western blotting. Moreover, in vivo studies were conducted to observe bone regeneration and vascular formation of critical-sized bone defects in rats using micro-computed tomography, histological analyses, Microfil® perfusion, fluorescence labeling, and immunohistochemical analysis. The results showed that DMOG and rhBMP-2 released in the MBG-PHBHHx scaffolds did exert synergistic effects on the osteogenic and angiogenic differentiation of hBMSCs. Moreover, DMOG and rhBMP-2 produced significant increases in newly-formed bone and neovascularization of calvarial bone defects in rats. It is concluded that the co-delivery strategy of both rhBMP-2 and DMOG can significantly improve the critical-sized bone regeneration.

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.

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.

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.

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.

Survival and number of olfactory ensheathing cells transplanted in contused spinal cord of rats.

OBJECTIVE: To observe the survival and the number of olfactory ensheathing cells (OECs) transplanted in the contused spinal cord, so as to provide a basis for further studying the biological action of OECs. METHODS: The rat spinal cords were contused with NYU-impactor II at T10 level by dropping a 10 g rod from a height of 25 mm. At the 1st week after injury, OECs isolated freshly from green fluorecense protein (GFP) of the rats were transplanted into the spinal cord at injured site and other two sites 1 mm apart from the caudal and rostral ends with the OECs number of 30000/µl x 3 = 90000. The survival and the number of OECs were qualitatively and semi-quantitatively observed under the fluorescense microscope from 1 week to 13 weeks after transplantation. The motor function of the cord was evaluated with BBB score. RESULTS: GFP-OECs could survive at least for 13 weeks within the contused spinal cord. Their arrangement was from tight to loose and their number was decreased from 1 week to 13 weeks after injury. The average number of GFP-OECs was 536 at the 1st week, which was less than 1% of the number as compared with original transplantation. After then, the number of GFP-OECs was continually decreased, but the most obvious decrease was found during 1 week to 2 weeks. The extent of decrease at other time points was relatively mild. In contrast to the cell number, motor function of the cord was gradually recovered after transplantation. CONCLUSIONS: The survival and the number of GFP-OECs are different between the animals and are affected by the pathological reaction of the host cord. Also it is related to the motor function recovery of the contused cord.

[Study on the biological activity of activated sludge using a rapid biological activity tester].

Based on a Rapid Biological Activity Tester (RBAT), a study was taken on the sludge activity which is one of the most important parameters in the operation of aerated biological treating unit in WWTP to measure the effect of the external environmental conditions on the sludge activity, such as acidity and alkalinity, temperature, toxicity, etc. It is observed that the variety of the activity parameters is limited in 20% for a long time. While pH is deviated from the normal value, the biological activity drops to some degree, and furthermore, the ability of the microorganism to endure the acerbic environment is much higher than that to endure the alkaline environment. Temperature increase can result in the enhancement of the biological activity, and if the temperature is higher than 42.5 degrees C, the biological activity is greatly inhibite, but the endogenous respiring rate is less influenced by high temperature. Toxicity can greatly inhibit the biological activity of the activated sludge, and the inhibition is probably selective. Finally, the biological activity of the activated sludge from a real wastewater treatment plant was tested, and the standard deviation of the result is less than 20%. The results indicate that the RBAT is a promising method to measure biological activity, and the characteristics of activated sludge can be well expressed.