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This study aimed to study the relationship between air pollution and stroke (especially emergency stroke) in different regions and determine which air pollutant is the most significantly associated with stroke. The number of patients with emergency stroke, air pollutant data and related meteorological indicators were collected from December 2013 to May 2018 for large comprehensive hospitals in Chongqing. The generalized additive model was used to analyse the relationship between air pollution and emergency stroke. After analysis and adjusting for meteorological indicators and day-of-the-week effects, in the one-pollutant model, every 10 μg/m3 increase in ozone(O3) was associated with a 2.482% (95% CI 1.044%, 3.919%) change in emergency strokes within lag0. For males, every 10 μg/m3 increase of O3 contributed to a 0.77% percent greater change compared with females. For the group younger than 60 years, we observed a 1.14% increase in risk with every 10 μg/m3 increase in O3. The group with pre-existing hypertension had a 0.26% higher risk than the group with no pre-existing hypertension with every 10 μg/m3 increase in O3. In two-pollutant model, when O3 was combined with a 10 μg/m3 increase of NO2, it increased the most significant risk of emergency stroke by 0.22%. These findings suggest that short-term exposure to O3 within 0 days is associated with emergency outpatient strokes, and younger people (age

Advanced gastric cancer (AGC) and primary gastric lymphoma (PGL) are the two most common malignant tumors of the stomach. Conventional imaging examinations have difficulty distinguishing the two. This study explored the values of multiple parameters and visual assessment of 18F-fluorodeoxyglucose(18F-FDG) uptake heterogeneity of positron emission tomography/computed tomography(PET/CT) for differentiating between AGC and PGL. This retrospective study included 70 AGC and 26 PGL patients, all of whom had undergone 18F-FDG PET/CT before treatment. We analyzed the differences between AGC and PGL in the distribution of metastatic lesions and multiple metabolic parameters, including the maximum standardized uptake value (SUVmax), SUVmax/maximal thickness(THKmax), metabolic tumor volume and total lesion glycolysis (TLG). In addition, 18F-FDG uptake heterogeneity was visually assessed using a visual scoring method and a method of measuring SUVmax differences (SUVmax-d). The most common metastasis of AGC patients were liver, bone, peritoneal and proximal lymph nodes; PGL patients had fewer peritoneal metastases and lymph node metastasis could appeared to be “skip metastasis.” The metabolic parameters—SUVmax, SUVmax/THKmax and TLG—were higher in patients who had PGL, especially in diffuse large B-cell lymphoma (DLBCL). In the visual assessment of 18F-FDG uptake heterogeneity, the measurements of SUVmax-d in PGL were significantly higher than in AGC. Receiver operating characteristics curve analysis suggested that SUVmax has the highest comprehensive diagnostic efficiency due to having the highest value of area under the curve and the highest accuracy (77.2%). 18F-FDG PET/CT had a high diagnostic efficiency for discrimination of AGC and PGL, especially between DLBCL and other pathological subtypes. Visual assessment used to evaluate 18F-FDG uptake heterogeneity could help to distinguish the two types of tumors. In addition, our innovative method of measuring the heterogeneity of 18F-FDG uptake—namely, SUVmax-d—could contribute to identification of the two tumor types and should have its significance clarified by future studies.

Transplantation of mesenchymal stem cells (MSCs) has been considered an effective therapeutic treatment for a variety of diseases including bone fracture. However, there are associated complications along with MSCs transplantation. There is evidence to show that exosomes (Exos) derived from MSCs exert a similar paracrine function. In addition, repair capabilities of MSCs decline with age. Hence, this study aims to confirm whether the Exos protective function on osteogenic differentiation and fracture healing from aged MSCs was attenuated. This information was used in order to investigate the underlying mechanism. MSCs were successfully isolated and identified from young and aged rats, and Exos were then obtained. Aged-Exos exhibited significantly attenuated effects on MSCs osteogenic differentiation in vitro and facture healing in vivo. Using miRNA array analysis, it was shown that miR-128-3p was markedly upregulated in Aged-Exos. In vitro experiments confirmed that Smad5 is a direct downstream target of miR-128-3p, and was inhibited by overexpressed miR-128-3p. A series gain- and loss- function experiment indicated that miR-128-3P serves a suppressor role in the process of fracture healing. Furthermore, effects caused by miR-128-3P mimic/inhibitor were reversed by the application of Smad5/siSmad5. Taken together, these results suggest that the therapeutic effects of MSCs-derived Exos may vary according to differential expression of miRNAs. Exosomal miR-128-3P antagomir may act as a promising therapeutic strategy for bone fracture healing, especially for the elderly.

The potential association between medical resources and the proportion of oldest-old (90 years of age and above) in the Chinese population was examined, and we found that the higher proportion of oldest-old was associated with the higher number of beds in hospitals and health centers. Supplementary Information The online version contains supplementary material available at 10.1186/s40779-021-00307-6.

The construction project serves as one of the most important projects in the construction industry. The high cost and the particularity in the implementation generate high risks in the investment and construction process. Over the years, the development of construction project management methods has promoted the management of risk factors. This paper reviews the suggestions of risk management of follow-up audit in construction stage and evaluates its application in construction projects.

BACKGROUND Because facet joints move with the disc, changes in vertebral bodies occur simultaneously with progression of degeneration of cervical facet joints. This study investigated age-related differences in cervical facet joint abnormalities and multi-dimensional characteristics of MCs in patients with cervical spondylotic myelopathy. MATERIAL AND METHODS Forty-five patients underwent both magnetic resonance imaging (MRI) and computed tomography (CT) of the cervical spine. Axial and sagittal parameter changes from C3 to C7, including facet orientation (FO) and facet tropism (FT), and Modic changes (MCs), were evaluated and documented preoperatively, and we also measured the heights and diameters of MCs and performed correlation analysis and established linear regression models. RESULTS The axial facet orientation increased slightly from C3 66.5 (11.4) to C7 89.9 (19). The sagittal facet orientation and facet tropism increased between C3-C4 and C6-C7, but it decreased between C4 to C6. The MCs volume decreased from C3 to C4 and increased from C4 to C7. There was a gradual decrease of FO and FT from C3 to C5 and a gradual increase of these 2 angles from C5 to C7 in all age groups. The lowest values of FO and FT were detected at C5, while the highest values of FO and FT were detected at C7. CONCLUSIONS Age was negatively correlated with the axial, sagittal, and coronal cervical facet orientation, especially at C4/5 level. The FT with respect to the axial and sagittal plane from C5 to C6 increased with age.

Background: Several studies have substituted the T1 slope (T1S) with the C7 slope (C7S) because the C7 endplate is clearer on radiographs. Further, abnormal serum lipid levels have been proven to be related with the development of disc degeneration. The aim of this study was to explore the relationship between C7S, serum lipid levels, cervical parameters related to cervical sagittal balance and Modic changes (MCs) in patients with multisegment cervical spondylotic myelopathy (CSM). Methods: Between January 2014 and January 2017, 75 patients with multisegment CSM were enrolled in our retrospective study. Gender, age, history of smoking status and alcohol consumption, and laboratory test data were recorded. The cervical sagittal balance parameters C7S, T1S, cervical lordosis (CL), neck tilt (NT), thoracic inlet angle (TIA), C2-C7 sagittal vertical axis (SVA), and T1S-CL were analyzed with Spearman correlation tests and multiple linear regression analysis. We diagnosed MCs through computed tomography or magnetic resonance imaging of the cervical spine. Patients were divided into four subgroups according to the presence or absence of MCs and their C7S values. Results: 75 patients were included in our study. Age, gender, C7S, and T1S were significantly different between the two groups. However, there was no statistical difference with regard to smoking status, alcohol consumption, lipoprotein(a), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, albumin, globulin, triglycerides, total cholesterol, Ca2+, CL, T1S, TIA, NT, and T1S-CL. The correlation between HDL-C, LDL-C, ALB, GLB, Ca2+, C7S, T1S, MCs, NT, TIA, and C2-C7 SVA was statistically significant. Conclusion: Significant correlations were observed between MCs and TG (as well as other preoperative sagittal parameters), which may accelerate the development of degeneration of the cervical spine. Therefore, alcohol consumption, TG, and sagittal parameters, such as C7S, and T1S could be a promising candidate for the assessment of cervical sagittal balance and predicting neck pain.

Osteosarcoma (OS) has emerged as the most common primary musculoskeletal malignant tumor which affects children and adolescents. A growing number of relevant studies have shown that many microRNAs (miRNAs) play a vital regulatory role in the etiology of various types of cancer. miR-1258 has been widely studied in various cancers, but there have been few studies of its role in OS. In this present study, miR-1258 expression was dramatically decreased in OS tissues as well as OS cell lines. In addition, decreased expression of miR-1258 was significantly associated with malignant clinical manifestations and poor clinical prognosis of patients with OS. Moreover, upregulation of miR-1258 significantly inhibited cell proliferation as well as promoting cell cycle arrest at G0/G1. AKT3 was identified as a direct target of miR-1258 by binding to its 3'-UTR, and miR-1258 was negatively correlated with AKT3 expression in clinical OS tissues. AKT3 was evidently upregulated in OS tissues and cells and upregulation of AKT3 accelerated the progression of OS. Moreover, through a series of rescue experiments, we demonstrated that AKT3 can abolish the role of miR-1258 in suppressing proliferation as well as regulating the cell cycle in OS cells. In conclusion, our results suggest that the miR-1258-AKT3 axis may be a promising prognostic marker and therapeutic target for human OS.

Mesenchymal stem cell (MSC) transplantation is now considered as an effective treatment strategy for traumatic spinal cord injury (SCI). However, several key issues remain unresolved, including low survival rates, cell dedifferentiation, and tumor formation. Recent studies have demonstrated that the therapeutic effect of transplanted stem cells is primarily paracrine mediated. Exosomes are an important paracrine factor that can be used as a direct therapeutic agent. However, there are few reports on the application of exosomes derived from bone MSCs (BMSCs-Exos) in treating SCI. In this study, we demonstrated that BMSCs-Exos possessed robust proangiogenic properties, attenuated neuronal cells apoptosis, suppressed glial scar formation, attenuated lesion size, suppressed inflammation, promoted axonal regeneration, and eventually improved functional behavioral recovery effects after traumatic SCI. Briefly, lesion size was decreased by nearly 60%, neuronal apoptosis was attenuated by nearly 70%, glial scar formation was reduced by nearly 75%, average blood vessel density was increased by nearly 60%, and axonal regeneration was increased by almost 80% at day 28 after SCI in the BMSC-Exos group compared to the control group. Using a series of in vitro functional assays, we also confirmed that treatment with BSMCs-Exos significantly enhanced human umbilical vein endothelial cell proliferation, migration, and angiogenic tubule formation, attenuated neuronal cells apoptosis, and suppressed nitric oxide release in microglia. Moreover, our study demonstrated that administration of BMSCs-Exos suppressed inflammation efficiently after traumatic SCI and suppressed activation of A1 neurotoxic reactive astrocytes. In conclusion, our study suggested that the application of BMSCs-Exos may be a promising strategy for traumatic SCI.

Yuluo Rong,* Yongjun Luo,* Wei Liu, Fangyi Gong, Pengyu Tang, Weihua Cai Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China *These authors contributed equally to this work Objective: To investigate the early and mid-term efficacy and safety of the bridge-type ROI-C interbody fusion cage system in the treatment of cervical spondylosis with osteoporosis during anterior cervical discectomy and fusion (ACDF). Patients and methods: The clinical data from 24 cervical spondylosis patients with osteoporosis treated with ACDF were retrospectively analyzed. All patients were treated with ROI-C cage. Double-energy X-ray absorptiometry (DEXA) was used to measure the bone mineral density (BMD). The cervical sagittal radiographic parameters were measured and compared using X-ray including C2–C7 Cobb angle, segmental angle (SA), cervical vertebral bow depth, and height of operation segment (HOS). Postoperative dysphagia was recorded according to the Bazaz score. The Japanese Orthopedic Association (JOA) scores and Neck Disability Index (NDI) scores were used to evaluate the clinical outcomes at different time points. Odom and Vaccaro criteria were used to assess the surgical effects and to evaluate the fusion of the bone graft. Results: The mean duration of the postoperative follow-up was 27.4±5.7 months (ranging from 21 to 36 months). The JOA scores and NDI scores at 3 months post operation and at the time of final follow-up were significantly different from those before surgery (P0.05). Conclusion: The ROI-C cage system is safe and effective for use in patients undergoing anterior cervical spondylosis surgery for osteoporosis treatment. It results in a positive effect on bone graft fusion, is able to effectively improve cervical curvature, restores intervertebral height, and reduces the incidence of postoperative dysphagia. The clinical effects were positive at the early and middle postoperative stages. Keywords: cervical spondylosis, ROI-C, osteoporosis, imaging parameters, dysphagia

This study aims to explore the effects of exosomes derived from G protein-coupled receptor kinase 2 interacting protein 1 (GIT1)-overexpressing bone marrow mesenchymal stem cell (GIT1-BMSC-Exos) on the treatment of traumatic spinal cord injury (SCI) in a rat model.All the rats underwent a T10 laminectomy. A weight-drop impact was performed using a 10-g rod from a height of 12.5 mm except the sham group. Rats with SCI were distributed into three groups randomly and then treated with tail vein injection of GIT1-BMSCs-Exos, BMSCs-Exos and PBS, respectively. The effects of GIT1-Exos on glutamate (GLU)-induced apoptosisThe results showed that rats treated with GIT1-BMSCs-Exos had better functional behavioral recovery than those treated with PBS or BMSCs-Exos only. The overexpression of GIT1 in BMSCs-Exos not only restrained glial scar formation and neuroinflammation after SCI, but also attenuated apoptosis and promoted axonal regeneration in the injured lesion area. Neuronal cell death induced by GLU was controlled remarkablyIn conclusion, our study suggested that the application of GIT1-BMSCs-Exos may provide a novel avenue for traumatic SCI treatment.

Objective Lumbar disk herniation (LDH) is a complex condition based on lumbar disk degeneration (LDD). Previous studies have shown that genetic factors are highly associated with the severity and risk for LDH. This case‐control study was aimed to evaluate the association between the matrix metalloproteinase (MMP)‐3 gene rs591058 C/T polymorphism and LDH risk in a southern Chinese population. Methods A total of 231 LDH patients and 312 healthy controls were recruited in this study. Genotyping was analyzed using a standard polymerase chain reaction and restriction fragment length polymorphism (PCR‐RFLP). Results It was observed that TT genotype or T allele carriers of the MMP‐3 gene rs591058 C/T polymorphism was more likely associated with an increased risk for LDH. Subgroup analyses showed the following characteristics increased the risk for LDH: female sex; cigarette smoking; and alcohol consumption. Furthermore, individuals with high whole body vibration, bending/twisting, and lifting were associated with an increased risk for LDH. Conclusion Taken together, these data indicated that the MMP‐3 gene rs591058 C/T polymorphism was associated with an increased risk for LDH. The MMP‐3 gene rs591058 C/T polymorphism might serve as a clinical indicator and marker for LDH risk in the Chinese population.

Ischemia-reperfusion injury is the second most common injury of the spinal cord and has the risk of neurological dysfunction and paralysis, which can seriously affect patient quality of life. Salidroside (Sal) is an active ingredient extracted from Herba Cistanche with a variety of biological attributes such as antioxidant, antiapoptotic, and neuroprotective activities. Moreover, Sal has shown a protective effect in ischemia-reperfusion injury of the liver, heart, and brain, but its effect in ischemia-reperfusion injury of the spinal cord has not been elucidated. Here, we demonstrated for the first time that Sal pretreatment can significantly improve functional recovery in mice after spinal cord ischemia-reperfusion injury and significantly inhibit the apoptosis of neurons both in vivo and in vitro. Neurons have a high metabolic rate, and consequently, mitochondria, as the main energy-supplying suborganelles, become the main injury site of spinal cord ischemia-reperfusion injury. Mitochondrial pathway-dependent neuronal apoptosis is increasingly confirmed by researchers; therefore, Sal’s effect on mitochondria naturally attracted our attention. By means of a range of experiments both in vivo and in vitro, we found that Sal can reduce reactive oxygen species production through antioxidant stress to reduce mitochondrial permeability and mitochondrial damage, and it can also enhance the PINK1-Parkin signaling pathway and promote mitophagy to eliminate damaged mitochondria. In conclusion, our results show that Sal is beneficial to the protection of spinal cord neurons after ischemia-reperfusion injury, mainly by reducing apoptosis associated with the mitochondrial-dependent pathway, among which Sal’s antioxidant and autophagy-promoting properties play an important role.

Wei Liu,* Yuluo Rong,* Jian Chen,* Yongjun Luo, Pengyu Tang, Zheng Zhou, Jin Fan, Weihua Cai Department of Orthopaedic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China *These authors contributed equally to this work Purpose: To explore the role of cervical sagittal alignment in the occurrence of adjacent-level ossification development (ALOD) in patients who underwent anterior cervical discectomy fusion with self-locking stand-alone polyetheretherketone cage, and the relationship between cervical sagittal alignment and clinical outcomes.Background: Because of its advantages, anterior cervical plating systems have been used as the classic surgical method in the treatment of patients with cervical disc herniation. However, the proximity (0.05) and C2–C7 sagittal vertical axis (P>0.05) showed no difference. Compared with preoperative scores, improvement was seen in postoperative visual analog scale, JOA and NDI scores at each time point (P

Background When lowlanders rapidly ascend to altitudes > 2500 m, they may develop acute mountain sickness (AMS). The individual susceptibility, ascending velocity, time spent at altitude, activity levels and altitude reached are considered risk factors for AMS. However, it is not clear whether sex is a risk factor. The results have been inconclusive. We conducted a meta-analysis to test whether there were sex-based differences in the prevalence of AMS using Lake Louise Scoring System. Methods Systematic searches were performed in August 2019 in EMBASE, PubMed, and Web of Science for prospective studies with AMS data for men and women. The titles and abstracts were independently checked in the primary screening step, and the selected full-text articles were independently assessed in the secondary screening step by the two authors (YPH and JLW) based on pre-defined inclusion criteria. The meta-analysis was performed using by the STATA 14.1 software program. A random-effects model was employed. Results Eighteen eligible prospective studies were included. A total of 7669 participants (2639 [34.4%] women) were tested. The results showed that there was a statistically significant higher prevalence rate of AMS in women than in men (RR = 1.24, 95%CI 1.09–1.41), regardless of age or race. Howerver, the heterogeneity was significant in the analysis (Tau2 = 0.0403, Chi2 = 50.15, df = 17; I2 = 66.1%, P = 0.000), it was main caused by different numbers of subjects among the studies (coefficient = − 2.17, P = 0.049). Besides, the results showed that there was no evidence of significant publication bias in the combined studies on the basis of Egger’s test (bias coefficient = 1.48, P = 0.052) and Begg’s test (P = 0.130). Conclusions According to this study, the statistically significant finding emerging from this study was that women have a higher prevalence of AMS. However, the authors could not exclude studies where patients were on acetazolamide. Our analysis provided a direction for future studies of the relationship of sex and the risk of AMS, such as the pathological mechanism and prevention research.

Purpose To establish an accurate and reliable equation for kidney depth estimation in adult patients from different Chinese geographical regions. Method This multicenter study enrolled Eastern Asian Chinese patients with abdominal PET/CT scans at 26 imaging centers from six macro-regions across China in 3 years. Age, gender, height, weight, primary disease and its extent on PET scans of the participants were collected as potential predictive factors. Kidney depth on CT, defined as the average of the vertical distances from the posterior skin to the farthest anterior and closest posterior surfaces of each kidney, was measured as the standard reference. The new kidney depth model was constructed using a multiple regression model, and its performance was compared to those of three established models by computing the absolute value of estimation errors in comparison with CT-measured kidney depth. Results A total of 2502 patients were enrolled and classified into training (n=1653) and testing (n = 849) subsets. In the training subset, two kidney depth models were constructed: Left (cm): 0.013×age+0.117×gender-0.044×height+0.087×weight+7.951, Right (cm): 0.005×age+0.013×gender-0.035×height+0.082×weight+7.266 (weight: kg, height: cm, gender = 0 if female, 1 if male). In the testing subset, one-way analysis of variance showed that the estimation errors of the new models did not significantly differ among the 6 regions. Bland-Altman analysis determined that new equations had lower estimated biases (left: 0.039 cm, right: 0.018 cm) compared with other existing models. Conclusion The new equations were highly accurate for kidney depth estimation in adults from all over China, with lower estimation errors compared to other established models.

Dear editor, Soldiers have to face different environments according to different tasks, such as high-altitude, tropical, island and cold regions, as well as the Gobi Desert. Therefore it is necessary to consider the impact of environmental characteristics on medical service, including the

High-altitude deacclimatization syndrome (HADAS) is involved in hypoxia-reoxygenation injury and inflammatory response, induced a series of symptoms, and has emerged as a severe public health issue. Here, we investigated the mechanism as well as potential means to prevent HADAS using Shenqi pollen capsules (SPCs) in subjects with HADAS in a multicenter, double-blinded, randomized, placebo-controlled study. All subjects were at the same high altitude (3650 m) for 4-8 months before returning to lower altitudes. Subjects (n=288) in 20 clusters were diagnosed with mild or moderate HADAS on the third day of the study. We randomly allocated 20 clusters of subjects (1 : 1) to receive SPCs or a placebo for 7 weeks, and they were then followed up to the 14th week. The primary endpoints were subjects’ HADAS scores recorded during the 14 weeks of follow-up. Compared with the placebo, SPC treatment significantly decreased the subjects’ HADAS scores and reduced the incidence of symptom persistence. SPC therapy also reduced the serum levels of CK, CK-MB, LDH, IL-17A, TNF-α, and miR-155 and elevated IL-10 and miR-21 levels. We thus demonstrate that SPCs effectively ameliorated HADAS symptoms in these subjects via suppression of the hypoxia-reoxygenation injury and inflammatory response.

Purpose. The endplate defects (EDs), Modic changes (MCs), disc degeneration (DD), facet orientation (FO), and facet tropism (FT) were demonstrated to be related to the low back pain (LBP). The aim of this study was to investigate possible correlations between them. Methods. 75 patients were reviewed to evaluate the degenerative change in vertebral bodies (EDs and MCs), intervertebral discs (DD), and facet joint degeneration (FO and FT). All patients were categorized into four groups based on the grade of EDs. Clinical outcomes were evaluated with the visual analog scale (VAS) and Oswestry disability index (ODI) before and after surgery. Results. There was no difference between the four groups in baseline characteristics except for gender and weight. FT is positively correlated with FO. The same rule exists between EDs, the size of MCs II, FO (left) and FO (right), and VAS and ODI. The grade of EDs is positively correlated with the grade of DD. L4-L5 can bear more load than other levels; thus, the grade of EDs is higher than that of other lumbar levels. The preoperative LBP was relieved in all groups in varying degrees. The change of pain and dysfunction is inversely proportional to the grade of EDs in the general trend. Conclusion. The relationship between weight, gender, and disc degeneration provided a mechanism by which increasing weight can predispose to DD. Different grades of EDs had different effects on patients with LBP. There was a significant correlation between EDs, MCs II, DD, FT, and FO.

In view of the overlapping project between the double track bridge of Ningbo-Taizhou-Wenzhou expressway and seawall, the large-scale three-dimensional finite element calculation is carried out by using the finite element software ABAQUS, the displacement limit of bridge pier top is studied, the internal force deformation of bridge pile foundation and its variation law in the process of seawall filling and later consolidation settlement are analyzed, and the influence of sea seawall filling on the stress and deformation of bridge pile foundation is studied. The calculation results show that: the main pier in the enclosure side of the two main piers in the design scheme is most affected by the construction of seawall. At the end of seawall construction, the longitudinal displacement along the bridge is 25.56cm, the transverse displacement is -10.68cm, and the settlement is 3.49cm. From the beginning of seawall construction to 15 years after the completion of seawall, the maximum longitudinal displacement along the bridge is -80.87cm, the maximum transverse displacement is -38.94cm, and the maximum settlement is 382.2cm, in which the settlement during the construction period is 346.0cm, accounting for 90.5%. The calculation results of design scheme show that the displacement of bridge pier top is too large, and the tensile stress of bridge pile is also large, therefore, it is necessary to optimize the design scheme to reduce the displacement of the bridge.

Background AMS is a disease that occurs when accessing high altitude (HA) or upon exposure to a higher altitude after acclimatising over 3000m. Evidence shows that drugs can prevent AMS. The function of dexamethasone for preventing AMS is important. No systematic review has previously been published about the effect of dexamethasone. The effect of intervention is unclear, which has limited the use of dexamethasone in the prevention of AMS. Methods We searched PubMed and Embase for studies from inception to July 2013. We selected randomised controlled trials including dexamethasone versus placebo as prophylaxis for AMS. The studies included were required to provide a clear dose of dexamethasone, the final altitude and clear diagnostic criteria used to judge the AMS severity of symptoms and incidence. Finally, 8 studies were included in this review. There were 116 participants in the experimental groups and 110 in the control groups. Three different doses of dexamethasone were used in these studies (8, 12, and 16mg/d). Result Eight of the 79 considered studies were eventually added to the meta-analysis. We used the fixed-effect model (RevMan 5.0) based on the heterogeneity (I 2 =0%, p=0.43). Dexamethasone could reduce the incidence of AMS with an odds ratio of 6.03 (95% CI, 2.23 to 21.00) for dexamethasone compared with placebo; the p value for overall effect was less than 0.00001. Conclusions Our systematic review suggests that oral dexamethasone is effective in preventing AMS. Additionally, there is some evidence that the effect of dexamethasone is related to height and dosage.

Background People rapidly ascending to high altitudes (>2500 m) may suffer from acute mountain sickness (AMS). The association between smoking and AMS risk remains unclear. Therefore, we performed a meta-analysis to evaluate the association between smoking and AMS risk. Methods The association between smoking and AMS risk was determined according to predefined criteria established by our team. Meta-analysis was conducted according to the PRISMA guidelines. We included all relevant studies listed in the PubMed and Embase databases as of September 2015 in this meta-analysis and performed systemic searches using the terms “smoking”, “acute mountain sickness” and “risk factor”. The included studies were required to provide clear explanations regarding their definitions of smoking, the final altitudes reached by their participants and the diagnostic criteria used to diagnose AMS. Odds ratios (ORs) were used to evaluate the association between smoking and AMS risk across the studies, and the Q statistic was used to test OR heterogeneity, which was considered significant when P

The natural environment at high altitude triggers plateau diseases. This requires excellent military physicians that have graduated from high altitude military medical training to serve people on the plateau. High altitude military medical undergraduates need to complete a variety of military medicine courses. High altitude military medical geography is an important subject in military medicine that focuses on the relationship between the high altitude geographical environment and the health and medical support of military members. Considering military medical geographic information is a key aspect before military actions. This article summarizes the experience of teaching a high altitude military medical geography program, which has produced Chinese military medical undergraduates with excellent theoretical knowledge and practical skills. Our teaching process includes the first and second class levels. The former comprises theoretical and practical courses, including investigations in the field, practice on the plateau, and practice with geographic information systems. During the first class level teaching process, theoretical knowledge was reorganized and combined into four modules. After moving to the second class level, which last for 2–3 years, students continue to develop their military medical geography expertise under the guidance of teachers in summer school. This characteristic teaching mode supports the training of excellent high altitude military physicians for China.

The aim of our study was to develop a model of high altitude cerebral edema (HACE) using an acute, hypobaric hypoxia environment combined with exhaustive exercise. Forty healthy male Sprague-Dawley rats were randomly divided into a plains control group (PC group) and a plateau altitude hypoxia group (AH group). After 2 days of treadmill adaptation under normoxic conditions, the AH group was housed in hypobaric conditions (simulating 4000 m above sea level) for 2 days while performing exhaustive exercise. The simulated altitude was then increased to 8000 m for 3 days of simple hypobaric hypoxia exposure. Compared with the PC group, the AH group showed significantly greater (P

High-altitude pulmonary edema (HAPE) is a severe disease caused by high-altitude hypoxia. Since some individuals are more susceptible to high altitude than others, the incidence is variable and cannot be predicted. Furthermore, multiple genes can contribute to the occurrence of HAPE, making it even more difficult to predict. The genes associated with HAPE include those in the renin-angiotensin-aldosterone system pathway, the nitric oxide pathway and the hypoxia-inducible factor pathway. Other genes associated with HAPE include tyrosine hydroxylase (TH), vascular endothelial growth factor (VEGF), pulmonary surfactant proteins and β2-adrenergic receptor. The association of the polymorphisms of these genes with HAPE susceptibility has previously been investigated. Among the genes evaluated, polymorphisms of NOS3, ACE, CYP11B2, Hsp70 and endothelin-1 and pulmonary surfactant proteins A1 and A2 were shown to be associated with HAPE incidence, while associations between TH, VEGF and HAPE remain to be fully elucidated. Novel technological approaches, including genome-wide association studies and next-generation sequencing, are currently being used to identify new HAPE susceptibility genes. The goal of this review article is to summarize the current literature and to define the outstanding areas of research that need to be explored to advance our ability to predict when HAPE will occur.

China has the largest plateau in the world, which includes the whole of Tibet, part of Qinghai, Xinjiang, Yunnan, and Sichuan. The plateau area is about 257.2×10(4) km(2), which accounts for about 26.8% of the total area of China. According to data collected in 2006, approximately twelve million people were living at high altitudes, between 2200 to 5200 m high, on the Qinghai-Tibetan Plateau. Therefore, there is a need for medical workers who are trained to treat individuals living at high altitudes. To train undergraduates in high altitude medicine, the College of High Altitude Military Medicine was set up at the Third Military Medical University (TMMU) in Chongqing in 1999. This is the only school to teach high altitude medicine in China. Students at TMMU study natural and social sciences, basic medical sciences, clinical medical sciences, and high altitude medicine. In their 5(th) year, students work as interns at the General Hospital of Tibet Military Command in Lhasa for 3 months, where they receive on-site teaching. The method of on-site teaching is an innovative approach for training in high altitude medicine for undergraduates. Three improvements were implemented during the on-site teaching component of the training program: (1) standardization of the learning progress; (2) integration of formal knowledge with clinical experience; and (3) coaching students to develop habits of inquiry and to engage in ongoing self-improvement to set the stage for lifelong learning. Since the establishment of the innovative training methods in 2001, six classes of high altitude medicine undergraduates, who received on-site teaching, have graduated and achieved encouraging results. This evidence shows that on-site teaching needs to be used more widely in high altitude medicine education.

BACKGROUND AND OBJECTIVES Convincing evidence supporting the use of magnetic resonance imaging (MRI) as an effective tool for evaluating cervical sagittal alignment is lacking. This study aims to analyze the differences and correlations between cervical sagittal parameters on x-ray and MRI in patients with cervical disc herniation and to determine whether MRI could substitute for cervical x-ray for measurement of cervical sagittal parameters. METHODS One hundred forty-three adults with cervical disc herniation were recruited. Each patient had both an x-ray and MRI examination of the cervical spine. The cervical sagittal parameters were measured and compared on x-ray and MRI including: C2-C7 Cobb angle, C2-C7 sagittal vertical axis (C2-C7 SVA), cervical tilt (CT), T1 Slope (T1S), and neck tilt (NT). The data were analyzed using a paired-samples t test, a Pearson correlation test, and linear regression. RESULTS The values of C2-C7 Cobb angle, C2-C7 SVA, CT and T1S on X-ray were larger than those on MRI (P

Objective The visual analog score (VAS) is widely used in clinical medicine to evaluate the severity of subjective symptoms. There is substantial literature on the application of the VAS in medicine, especially in measuring pain, nausea, fatigue, and sleep quality. Hypobaric chambers are utilized to test and exercise the anaerobic endurance of athletes. To this end, we evaluated the degree of AMS using the visual analog scale (VAS) in a hypobaric chamber in which the equivalent altitude was increased from 300 to 3500 m. Methods We observed 32 healthy young men in the hypobaric chamber (Guizhou, China) and increased the altitude from 300 to 3500 m. During the five hours of testing, we measured the resting blood oxygen saturation (SaO2) and heart rate (HR). Using the VAS, we recorded the subjects' ratings of their AMS symptom intensity that occurred throughout the phase of increasing altitude at 300 m, 1500 m, 2000 m, 2500 m, 3000 m, and 3500 m. Results During the phase of increasing altitude in the hypobaric chamber, the patients' SaO2 was 96.8±0.8% at 300 m and 87.5±4.1% at 3500 m (P

Approximately 26.8% of China's land area has an elevation of 3000 m above sea level or higher. Because of recent demands for economic development and new construction in highland areas, many people have relocated from the plains to high plateau regions and have to face the possibility of contracting acute mountain sickness. Therefore, prevention and treatment strategies are necessary to reduce the incidence of acute mountain sickness in people who rapidly ascend to plateau areas. This paper describes the Chinese experience when large numbers of people moved to the plateau and the steps that were taken to deal with this illness. These steps included implementing basic prevention measures, increasing medical awareness among populations ascending to high altitudes, and installing standardized medical management systems to prevent and treat acute mountain sickness before, during, and after ascent. The incidence of acute mountain sickness can be reduced by improving prevention and treatment and by implementing the recommendations described in this manuscript.

The purpose of high altitude continuing medical education is to adapt knowledge and skills for practical application on the plateau. Most trainees have experience with academic education and grassroots work experience on the plateau, so they want knowledge about new advances in the pathogenesis, diagnosis, and treatment of high altitude disease. As such, traditional classroom teaching methods are not useful to them. Training objects, content, and methods should attempt to conduct a variety of teaching practices. Through continuing medical education on high altitude disease, the authors seek to change the traditional teaching model away from a single classroom and traditional written examinations to expand trainees' abilities. These innovative methods of training can improve both the quality of teaching and students' abilities to prevent and treat acute mountain sickness, high altitude pulmonary edema, high altitude cerebral edema, and chronic mountain sickness to increase the quality of high altitude medical care.

Luo, Yongjun, Yu Chen, Yao Zhang, and Yuqi Gao. The Association of Angiotensin-Converting Enzyme Gene Insertion/Deletion Polymorphisms with Acute Mountain Sickness Susceptibility: A Meta-Analysis. High Alt Med Biol 13:252–257, 2012.—Altitude exposure in nonacclimatized subjects may lead to acute mountain sickness (AMS). AMS is defined as headache upon recent arrival to altitude and may be accompanied by loss of appetite, nausea or vomiting, dizziness, fatigue, and poor sleep. Susceptibility for AMS varies and has been linked to angiotensin-converting enzyme (ACE) gene polymorphisms. We performed a meta-analysis of studies to assess the association between the ACE deletion (D) and insertion (I) alleles and AMS from published data. A fixed effects model was applied and study quality was assessed in duplicate. Five studies with a total of 333 AMS cases and 373 healthy controls were assessed. Our results revealed no significant differences in risk for AMS between carriers of ACE deletion and insertio...

The Chinese AMS score (CAS) is used in clinical medicine and research to diagnosis acute mountain sickness (AMS). However, the Lake Louise Score (LLS) is the well-accepted standard for diagnosing AMS. The difference between the CAS and LLS questionnaires is that the CAS considers more nonspecific symptoms. The aim of the present study was to evaluate differences in AMS prevalence according to the LLS and CAS criteria. We surveyed 58 males who traveled from Chongqing (300 m) to Lhasa (3658 m) via the Qinghai-Tibet train. Cases of AMS were diagnosed using LLS and CAS questionnaires in a few railway stations at different evaluation areas along the road. We subsequently evaluated discrepancies in values related to the prevalence of AMS determined using the 2 types of questionnaires (CAS and LLS). The prevalence of CAS-diagnosed AMS indicated that the percentage of AMS cases among the 58 young men was 29.3% in Golmud, 60.3% in Tanggula, 63.8% in Lhasa, 22.4% on the first day after arrival in Lhasa, 27.6% on the second day, 24.1% on the third day, and 12.1% on the fourth day. The prevalence of LLS-diagnosed AMS in Golmud was 10.3%, 38% in Lhasa, and 6.9% on day 1, the prevalence in each station was lower than that as assessed by the CAS. Our experimental data indicate that AMS diagnoses ascertained using the CAS indicate a higher AMS prevalence than those ascertained using the LLS. Through statistical analysis, the CAS seems capable of effectively diagnosing AMS as validated by LLS (sensitivity 61.8%, specificity 92.7%).

Pathophysiological characteristics of hemorrhagic shock at high altitude are different from that at plain which involve severe injury, high mortality, difficult treatment and compromised liquid tolerance. High-altitude pulmonary/cerebral edema and multiple-organ dysfunction render the conventional treatment ineffective. Herein, we evaluated the resuscitation effects of hyperoxia solution on high-altitude hemorrhagic shock in rats. For this purpose, a rat model of high-altitude (3,658 m) hemorrhagic shock was established on the plateau and hyperoxia solution (4 ml/kg) was infused through external jugular vein for resuscitation at 60 min post-hemorrhage. Blood pressure, blood gas, left and right ventricular pressure, lung and brain water content, survival time, survival rate at 2 h, levels of inflammatory cytokines and free oxygen radicals in blood and tissue were determined. After resuscitation with hyperoxia solution, blood pressure, arterial oxygen partial pressure, left and right ventricular systolic pressure, ±dp/dt max, survival time and rate were significantly increased. Lung and brain water content were unchanged, malondialdehyde activity in lung, brain and plasma and levels of TNF-α, IL-1, IL-6, and endothelin were significantly decreased. Besides, CGRP was elevated with reduced injury and improved lung and kidney functions. Concludingly, resuscitation with hyperoxia solution is feasible and more effective than other classical liquids, making it the first choice of treatment for high-altitude hemorrhagic shock.

Background High altitude pulmonary edema (HAPE) is a potentially deadly disease associated with exposure to altitudes greater than 3000 m. Individuals who have previously experienced HAPE are at a significantly higher risk of recurrence, suggesting an underlying genetic component to HAPE pathogenesis. In a previous nuclear genomic study of individual variation in susceptibility to HAPE, the endothelial nitric oxide synthase (eNOS) gene G894T polymorphism was identified as being associated with HAPE. However, another study found no association. Because of the low incidence of HAPE, sample sizes in current reports have been relatively limited. In this study, the association between the eNOS G894T polymorphism and HAPE was assessed through a meta-analysis of published data. Methods The literature was searched in PubMed, Web of Science, and Embase for papers published before July 15, 2011. A fixed-effects model and a random-effects model were applied (Revman 5.0) on the basis of heterogeneity, and study quality was assessed in duplicate. Results Five studies with 360 HAPE patients and 469 control subjects were analyzed. There were no significant differences between carriers of the eNOS 894G and 894T polymorphism alleles in terms of the risk of developing HAPE. Conclusions The eNOS 894G and 894T polymorphism alleles are not associated with HAPE incidence.

Background Chronic mountain sickness (CMS), originally characterized by excess hemoglobin (Hb), is currently diagnosed using score-based diagnostic criteria combined with excessive erythrocytosis and clinical symptoms. However, the current criteria have limited applicability. We applied these criteria to 1,029 Chinese Han males migrated to and have been stayed at the Qinghai-Tibet plateau (3,700–5,000 m) for 2–96 months to investigate the prevalence of CMS and its correlations with Hb concentration, altitude, and the length of residence. Methods Subjects were screened for CMS using the latest approved diagnostic criteria combined with excessive erythrocytosis and clinical symptoms. Hb concentrations were measured, and a cut-off point was determined with k-means clustering. Predisposing factors were evaluated with binary logistic analysis and curve fitting analysis. Results (1) The prevalence of CMS at the Qinghai-Tibetan plateau was 17.8% (183/1029 subjects, with CMS score ≥ 6, and Hb ≥ 210 g/L), which is higher than that previously reported. (2) While individuals were identified into two Hb clusters with a cut-off point of 200 g/L, in the low-Hb cluster (Hb 4500 m.

Background Iodine deficiency disorders (IDD) refer to diseases that are caused by insufficient iodine intake, and the best strategy to prevent IDD is the addition of iodine to dietary salt. Because iodine deficiency is a common cause of goiter, the prevalence as effectively controlled after the implementation of universal salt iodization (USI) in China. However, there is substantial controversy as to whether the incidence of thyroid disorders is related to iodized salt intake. Therefore, we aimed to clarify whether the risk of goiter can be promoted by USI. Methods A longitudinal continuous study based on the national monitoring results of IDD in China was performed for 3 consecutive years. We recorded the following indicators of IDD from 31 provinces: goiter number, two degrees of goiter (the degree of goiter severity) and cretinism (three endemic diseases), iodized salt intake, median urinary iodine concentration (UIC), soil iodine content and coverage rates of iodized salt. One-way Analysis of Variance (ANOVA) and linear regression analyses examined the differences between the three groups and correlations, respectively. Data were collected from the Chinese national IDD surveillance data in 2011-2013, and the background values of Chinese soil elements were published in 1990. Results A reference male’s daily intake of maximum iodine was 378.9 μg, 379.2 μg and 366.9 μg in 2011, 2012, and 2013, respectively. No statistical association between daily iodized salt intake and the three endemic diseases was observed in 2011-2013 (P > 0.05). No association was observed between daily iodized salt intake and the UIC of children in 2011 (P > 0.05). Linear regression revealed no significant correlation between the soil iodine content and three endemic diseases. The present study indicated no difference in the daily iodized salt intake in each province during three years (F = 0.886, P = 0.647). The coverage rate of iodized salt remained above 98.7%, and goiter rates were stable in 2011-2013. Conclusion There was no significant association between iodized salt intake and the three endemic diseases, suggesting that the current nutrition level of iodized salt did not cause the high goiter prevalence.