[A preliminary study on the evaluation of diaphragm function by ultrasound in patients with invasive mechanical ventilation]

Objectives: To study the feasibility of using ultrasound to evaluate diaphragm function in patients with invasive mechanical ventilation. Methods: From March to December 2017, 40 adult patients with acute respiratory distress syndrome who were admitted to the Department of Critical Care Medicine, Xiangya Hospital, Central South University for more than 48 hours were included. Diaphragmatic excursion and thickness of bilateral anterior, middle and posterior parts were measured by ultrasound for 5 consecutive days. Results: (1) Compared with the diaphragmatic excursion of the right [anterior: (11.05±3.04) mm; middle: (12.08±2.71) mm; posterior: (11.51±3.33) mm] and left [anterior: (13.63±7.52) mm; middle: (15.44±7.52) mm; posterior: (14.76±6.93) mm] sides on day 1, the diaphragmatic excursion of the right [anterior: (8.90±3.65) mm; middle: (10.02±4.24) mm; posterior: (10.25±4.38) mm] and left [anterior: (9.82±1.96) mm; middle: (11.60±1.13) mm; posterior: (11.52±1.98) mm] sides decreased significantly on day 3 (P<0.05). Bilateral anterior, middle and posterior diaphragmatic excursion recovered on day 5, and was higher than the baseline levels on day 1, with the left middle and posterior diaphragmatic excursion changing most significantly. (2) Compared with day 1, 2, 3, the thickening fraction of bilateral anterior, middle and posterior diaphragm were significantly decreased on day 4, with the left middle part [day 1: (33.87±14.34)%; day 2: (37.26±13.91)%; day 3: (30.56±14.27)%; day 4: (15.53±5.68)%] and the left posterior part [day 1: (35.50±15.69)%; day 2: (39.84±15.32)%; day 3: (29.06±14.96)%; day 4: (13.30±5.79)%] changing most significantly (P<0.05). The thickening fractions of left anterior, middle and posterior diaphragm recovered on day 5 compared with that on day 4, but still lower than those on day 1 (P<0.05). Conclusions: It is feasible to evaluate the diaphragm function in patients with invasive mechanical ventilation by ultrasound, which can provide guidance for preventing diaphragmatic atrophy and withdrawing from mechanical ventilation.

Panax notoginseng saponin R1 modulates TNF-α/NF-κB signaling and attenuates allergic airway inflammation in asthma

BACKGROUD

Panax notoginseng saponin R1 (PNS-R1) is one of the most important chemical monomers derived from the panax notoginseng, and our previous study found that PNS-R1 reduced glucocorticoid-induced apoptosis in asthmatic airway epithelial cells. Thus, in this study, we explored the effects of the PNS-R1 on inflammation of allergic asthma.

METHODS

The asthmatic mice were administered 15 mg/kg PNS-R1 by intraperitoneal injection three days before sensitized to OVA. The effects of PNS-R1 on asthmatic mice were detected by airway hyperresponsiveness, inflammation, mucus hypersecretion and inflammatory cytokines such as interleukin (IL)-13, IL-4, IL-5, IL-8 and tumor necrosis factor (TNF)-α were studied. We also treated human bronchial epithelial cells (16HBE) with house dust mites (HDM) and then detected the secretion of cellular inflammatory factors (IL-13 and TNF-α). Western blot and immunofluorescence were used to examine the effect of PNS-R1 on TNF-α/NF-κB pathway. TNF-α/NF-κB/IKK signal pathway activator was used in PNS-R1-treated asthmatic mice.

RESULTS

PNS-R1 significantly reduced the airway inflammatory, mucus secretion and hyperresponsiveness in asthma model. It also reduced the levels of IL-13, IL-4, IL-5 and IL-8 in bronchoalveolar lavage fluid (BALF) and IgE and OVA-specific IgE in serum for asthma mice. PNS-R1 reduced IL-13 and TNF-α secretion in HDM-treated 16HBE cells. In addition, PNS-R1 suppressed TNF-α/NF-κB pathway in both asthmatic mice and 16HBE. Activation of NF-kB pathway reversed the therapeutic effect of PNS-R1 on asthmatic mice.

CONCLUSION

The results indicated that PNS-R1 effectively suppresses allergic airway inflammation of asthma partly through TNF-α/NF-κB pathway. PNS-R1 may play a potential role in allergic asthma treatment in the future.

Application of telemedicine during the coronavirus disease epidemics: a rapid review and meta-analysis

Background

As COVID-19 has become a global pandemic, early prevention and control of the epidemic is extremely important. Telemedicine, which includes medical advice given over telephone, Internet, mobile phone applications or other similar ways, may be an efficient way to reduce transmission and pressure on medical institutions.

Methods

We searched MEDLINE, Web of Science, Embase, Cochrane, CBM, CNKI and Wanfang databases for literature on the use of telemedicine for COVID-19, SARS and MERS from their inception to March 31st, 2020. We included studies about the content of the consultation (such as symptoms, therapy and prevention, policy, public service), screening of suspected cases, the provision of advice given to those people who may have symptoms or contact history. We conducted meta-analyses on the main outcomes of the studies.

Results

A total of 2,041 articles were identified after removing duplicates. After reading the full texts, we finally included nine studies. People were most concerned about symptoms (64.2%), epidemic situation and public problems (14.5%), and psychological problems (10.3%) during COVID-19 epidemic. During the SARS epidemic, the proportions of people asking for consultation for symptoms, prevention and therapy, and psychological problems were 35.0%, 22.0%, and 23.0%, respectively. Two studies demonstrated that telemedicine can be used to screen the suspected patients and give advice. One study emphasized the limited possibilities to follow up people calling hotlines and difficulties in identifying all suspect cases.

Conclusions

Telemedicine services should focus on the issues that the public is most concerned about, such as the symptoms, prevention and treatment of the disease, and provide reasonable advice to patients with symptoms or people with epidemic history.

Development and validation of a simple-to-use nomogram for predicting refractory Mycoplasma pneumoniae pneumonia in children

OBJECTIVE

This study aimed to develop and validate a simple-to-use nomogram for predicting refractory Mycoplasma pneumoniae pneumonia (RMPP) in children.

METHODS

A total of 73 children with RMPP and 146 children with general Mycoplasma pneumoniae pneumonia were included. Clinical, laboratory, and radiological data were obtained. A least absolute shrinkage and selection operator (LASSO) regression model was used to determine optimal predictors. The nomogram was plotted by multivariable logistic regression. The performance of the nomogram was assessed by calibration, discrimination, and clinical utility.

RESULTS

The LASSO regression analysis identified lactate dehydrogenase, albumin, neutrophil ratio, and high fever as significant predictors of RMPP. This nomogram-illustrated model showed good discrimination, calibration, and clinical value. The area under the receiver operating characteristic curve of the nomogram was 0.884 (95% CI, 0.823-0.945) in the training set and 0.881 (95% CI, 0.807-0.955) in the validating set. Calibration curve and Hosmer-Lemeshow test showed good consistency between the predictions of the nomogram and the actual observations, and decision curve analysis showed that the nomogram was clinically useful.

CONCLUSION

A simple-to-use nomogram for predicting RMPP in early stage was developed and validated. This may help physicians recognize RMPP earlier.

[Clinical features of 9 cases of Brucella endocarditis]

Objective: To explore the clinical characteristics of patients with Brucella endocarditis. Methods: The clinical data of 9 patients with Brucella endocarditis admitted to Beijing Ditan Hospital from October 2008 to August 2018 were retrospectively analyzed. Through the electronic medical record system of the hospital. Through assessing the electronic medical record system of the hospital, demographic data, main symptoms, vital signs, blood culture, Rose Bengal Plate Agglutination Test, echocardiography, electrocardiogram, chest imaging and other clinical data of included patients were inquired and recorded. Patients were followed up by telephone for medication, operation and outcome. Results: The 9 patients were all Han nationality, aged from 25 to 66 years, 7 out of 9 patients were male, and they came from Hebei, Shandong, Shanxi, Inner Mongolia and Beijing. Of the 9 patients, 5 were farmers, 2 were self-employed, 1 was a technician, and 1 was unemployed. Of the 9 cases, 8 had a history of close contact with cattle and sheep, and 5 had a history of eating beef and mutton. Rose-Bengal Plate Agglutination Test and blood culture were positive in all 9 patients. Aortic valve was involved in 7 out of 9 patients, mitral and tricuspid valve was involved in 1 patient, respectively, and aortic dissection occurred in 1 patient. Condition of 1 patient rapidly deteriorated after admission and finally died during hospitalization despite antibiotic therapy, the remaining patients received long-term antibiotic treatment. A total of 7 patients who underwent valve replacement were followed up. One patient died of cerebral hemorrhage 6 months after operation, and the remaining 6 patients recovered well after valve replacement. Heart failure occurred in all 9 patients, and pericardial effusion occurred in 8 patients. Electrocardiogram showed low voltage of the QRS complex in the limb in 3 cases and poor R-wave progression in V(1)-V(3) lead in 2 cases, and sinus tachycardia in 2 cases. One patient developed non-specific ST-T abnormalities. All patients had fever, 7 patients complained of weakness, and 6 patients complained of palpitations. Among the 9 patients, 7 cases had anemia, 7 patients had pneumonia, 6 had bilateral pleural effusion, 4 had thrombocytopenia. Creatinine was above normal in 4 patients, urine protein was positive in 3 patients, Delta Bilirubin was higher in 3 cases. Conclusions: Patients with Brucella endocarditis often suffer from heart failure and have severe complications. Adequate antibiotic therapy in combination with valve replacement is effective for the treatment of patients with Brucella endocarditis.

Allogeneic human umbilical cord-derived mesenchymal stem cells for severe bronchopulmonary dysplasia in children: study protocol for a randomized controlled trial (MSC-BPD trial)

Background

Bronchopulmonary dysplasia (BPD) is a complex lung pathological lesion secondary to multiple factors and one of the most common chronic lung diseases. It has a poor prognosis, especially in preterm infants. However, effective therapies for this disease are lacking. Stem-cell therapy is a promising way to improve lung injury and abnormal alveolarization, and the human umbilical cord (hUC) is a good source of mesenchymal stem cells (MSCs), which have demonstrated efficacy in other diseases. We hypothesized that intravenously administered allogeneic hUC-MSCs are safe and effective for severe BPD.

Methods

The MSC-BPD trial is a randomized, single-center, open-label, dose-escalation, phase-II trial designed to investigate the safety and efficacy of hUC-MSCs in children with severe BPD. In this study, 72 patients will be enrolled and randomly divided into two intervention groups and one control group. Patients in the intervention groups will receive a low dose of hUC-MSCs (n = 24; 2.5 million cells/kg) or a high dose of hUC-MSCs (n = 24; 5 million cells/kg) in combination with traditional supportive treatments for BPD. The patients in the control group (n = 24) will be treated with traditional supportive treatments alone without hUC-MSCs. The primary outcome measures will be cumulative duration of oxygen therapy. Follow-up assessments will be performed at 1, 3, 6, 12, and 24 months post intervention, and the key outcome during follow-up will be changes on chest radiography. Statistical analyses will evaluate the efficacy of the hUC-MSC treatment.

Discussion

This will be the first randomized controlled trial to evaluate the safety and efficacy of intravenously administered hUC-MSCs in children with severe BPD. Its results should provide a new evidence-based therapy for severe BPD.

Trial registration

ClinicalTrials.gov, ID: NCT03601416. Registered on 26 July 2018.

[Inhibition of the TGF-β/Smad3 signaling pathway by SB431542: A study of the intervention effect of SB431542 on silicotic fibrosis in rats]

Objective: To investigate the intervention effect of SB431542, which inhibits the TGF-β/Smad3 signaling pathway, on silicotic fibrosis in rats. Methods: A total of 40 specific pathogen-free Sprague-Dawley rats were divided into normal saline control group, model group, SB431542 inhibitor group, and SB431542 inhibitor control group using a random number table, with 10 rats in each group. All rats except those in the normal saline control group were given non-exposed single intratracheal instillation of free silicon dioxide dust suspension 1 mL (50 mg/mL) ; the rats in the SB431542 inhibitor group were given intraperitoneal injection of SB431542 (5 mg/kg) on days 7 and 30 after dust exposure, those in the SB431542 inhibitor control group were given intraperitoneal injection of SB431542 cosolvent (5 mg/kg) on days 7 and 30 after dust exposure, and those in the normal saline control group were given intratracheal instillation of an equal volume of normal saline (5 mg/kg). On day 60 after dust exposure, the paraffin-embedded section of the right upper lobe of lung was collected for HE staining; the left upper lobe of lung was collected to measure the mRNA levels of fibronectin (FN) , collagen type I (COL-I) , and collagen type III (COL-III) by quantitative real-time PCR; the right inferior lobe of lung was collected to measure the protein levels of FN, COL-I, COL-III, phosphorylated Smad3 (p-Smad3) , and Smad3. Results: Compared with the normal saline control group, the model group had nodules with various sizes in lung tissue, with rupture of some alveolar septa, emphysema changes, and pulmonary interstitial fibrosis, as well as significant increases in the mRNA expression of FN, COL-I, and COL-III and the protein expression of FN, COL-I, COL-III, p-Smad3, and Smad3 in lung tissue (P<0.05) . Compared with the SB431542 inhibitor control group, the SB431542 inhibitor group had a relatively complete structure of lung tissue without marked nodules and with a small amount of exudate in alveolar space and the lumen of bronchioles, as well as significant reductions in the mRNA expression of FN, COL-I, and COL-III and the protein expression of FN, COL-I, COL-III, p-Smad3, and Smad3 in lung tissue (P<0.05) . There were no significant differences in the mRNA expression of FN, COL-I, and COL-III and the protein expression of FN, COL-I, COL-III, p-Smad3, and Smad3 between the model group and the SB431542 inhibitor control group (P>0.05) . Conclusion: SB431542 exerts an intervention effect on silicotic fibrosis by blocking the TGF-β/Smad3 signaling pathway and reducing the expression of the downstream fibrosis factors FN, COL-I, and COL-III.

[Delay on care-seeking and related influencing factors among tuberculosis patients in Wuhan, 2008-2017]

Objective: To analyze the epidemiological characteristics, trend and related factors of tuberculosis patients that delayed for care, in Wuhan from 2008 to 2017. Methods: Data regarding tuberculosis (TB) patients was collected from the tuberculosis management information system (TMIS), a part of the China information system for disease control and prevention from 2008 to 2017. A total of 64 208 tuberculosis patients, aged 0 to 95 years were included for the analysis. Unconditional logistic regression method was used to estimate those factors that associated with this study. Results: Days of delay among TB patients appeared as M=10 (P(25)-P(75): 3-28) day, in Wuhan, 2008-2017. The prevalence of the delay was 52.5% (33 703/64 208), presenting a downward trend from 2008 to 2017 (trend χ(2)=10.64, P<0.001), but the proportions of women and ≥65 year-olds were gradually increasing. Results from the multivariate logistic regression analysis showed that factors as: patients living far away from the city vs. near the city (OR=1.29, 95%CI: 1.25-1.35), and age above 45 years vs. younger than 25 years (the age 45-64 years group vs. aged less than 25 years group, OR=1.22, 95%CI: 1.15-1.29; the age 65 or above group vs. aged less than 25 years group, the OR=1.30, 95%CI: 1.22-1.39) were under higher risk on the delay of seeking care. Occupation, way of case-finding and classification of tuberculosis patients also appeared as influencing factors on this issue. Conclusions: Prevalence on the delay of care was 52.5% among tuberculosis patients in Wuhan, 2008-2017, but with an annual decrease. Attention should be paid to female, wrinkly or elderly tuberculosis patients regarding the delay of care on TB, in Wuhan.

Neoadjuvant chemotherapy with irinotecan and nedaplatin in a single cycle followed by esophagectomy on cT4 resectable esophageal squamous cell carcinoma: a prospective nonrandomized trial for short-term outcomes

Neoadjuvant chemotherapy (NAC) significantly extends survival in advanced esophageal squamous cell carcinoma (ESCC), but the short-term outcomes for cT4 ESCC remain controversial. Many NAC regimens have been previously reported, although no study has reported a regimen of irinotecan and nedaplatin for cT4 potential resectable ESCC. We evaluated the short-term outcomes of NAC with irinotecan and nedaplatin in a single cycle followed by esophagectomy on cT4 resectable ESCC. A total of 51 patients with cT4 potentially resectable ESCC were eligible for this study. Twenty of these patients underwent NAC, and the other 31 patients underwent surgery alone. The toxicities and response of NAC were evaluated. The clinicopathologic characteristics, responses, toxicities, surgical outcomes, postoperative complications, and survival time between the two groups were analyzed. No significant differences were found in clinicopathologic characteristics between the groups (P > 0.05). The response rate of NAC was 75% (15/20). The differences in the long-axis diameter of the tumor and cT stage between pre- and post-NAC were significant (P < 0.05). Twenty-four toxic events occurred in 11 patients of the NAC group, and 20/24 of these were mild. The R0 resection rates in the NAC group and the surgery alone group were 85% and 64.5%, with no statistically significant difference (P > 0.05). Differences in the pathological T stage and pathological tumor-node-metastasis (TNM) stage were significant (P < 0.05). The overall survival (OS) time and mortality in the NAC group versus the surgery alone group were 31.57 ± 3.06 months versus 15.24 ± 1.46 months and 25% versus 61.3%, respectively. The differences in OS and mortality were significant (P < 0.05). The NAC group and R0 resection were significant and independent predictors of positive prognosis. NAC with irinotecan and nedaplatin in a single cycle followed by esophagectomy on cT4 resectable ESCC as a new NAC is safe and effective.

Mechanism of Nucleoside Triphosphate Diphosphohydrolase-1-Associated Imbalance in Adenosine Diphosphate Degradation, B-Cell Activation, and Related Injury During Acute Antibody-Mediated Rejection

OBJECTIVE

The objective of this study was to investigate the effect of nucleoside triphosphate diphosphohydrolase-1 (NTPDase1) during acute antibody-mediated rejection (AMR).

METHODS

NTPDase1 overexpression, NTPDase1 knockout, and wild-type nude mice skin graft models were used to induce acute AMR. NTPDase1 expression in B cells, NTPDase1 messenger RNA expression in skin grafts, extracellular adenosine diphosphate (ADP) concentration, B-cell volume and surface antigens expression, average platelet transport rate, and ultrastructure and apoptosis of skin graft cells were investigated.

RESULTS

During acute AMR in nude mice, higher NTPDase1 expression caused lower extracellular ADP concentration, smaller increase in B-cell volume, and major histocompatibility complex II surface antigen expression, suggesting a negative correlation between them; higher NTPDase1 expression also caused slower average platelet transport rate and less severe skin graft injury, suggesting a negative correlation between them. Pretreatment with high-dose exogenous NTPDase1 inhibited platelet activation and protected skin grafts, but it resulted in prolonged bleeding time (by 51.4%) and prolonged coagulation time (by 44.1%).

CONCLUSION

An NTPDase1-associated imbalance in extracellular ADP degradation may contribute to B-cell activation, platelet activation, and more severe skin graft injury in nude mice. Pretreatment with high-dose exogenous NTPDase1 effectively protected skin grafts in nude mice at 1 week, but it increased the risk of bleeding.

LPS Exposure in Early Life Protects Against Mucus Hypersecretion in Ovalbumin-Induced Asthma by Down-Regulation of the IL-13 and JAK-STAT6 Pathways

BACKGROUND/AIMS

Previous studies have shown that lipopolysaccharide (LPS) exposure may have a protective effect on asthma by reducing airway hyper-responsiveness, airway inflammation and serum IgE levels. However, there are few studies investigating the effect of LPS on mucous secretion in asthma. In this study, we evaluate the relationship between LPS pre-treatment in infant mice and airway mucus hypersecretion in an OVA (ovalbumin)-induced asthma model, and further explore the mechanisms behind this effect.

METHODS

Mice were pre-treated with LPS by intranasal instillation (i.n.) from the 3rd day of life for 10 consecutive days before the OVA-induced asthma model was established. In order to detect mucus secretion, periodic acid-Schiff (PAS) staining was carried out, and the expression of Muc5ac was detected. The IL-13 levels in Bronchoalveolar lavage fluid (BALF) and lung tissue were also detected. In vitro, the expression of Muc5ac mRNA and protein was quantified in IL-13-stimulated 16HBE cells with or without LPS pre-treatment. In addition, proteins in the JAK2/STAT6 pathway, transcription factors (forkhead box transcription factor A2 (FOXA2), activation protein-1(AP-1), NF-κB), and the levels of reactive oxygen species (ROS) were also measured in vivo and in vitro.

RESULTS

LPS pre-treatment reduced mucus secretion, as demonstrated by decreased PAS staining and muc5ac expression. Further exploration of the underlying mechanisms of this phenomenon revealed that LPS pre-treatment decreased the production of IL-13, IL-13 induced ROS synthesis was reduced, and the JAK2/STAT6 pathway was inhibited. Decreased stat6 increased transcription factor FOXA2, and the relatively increased FOXA2 further decreased the level of Muc5ac and mucous hypersecretion in OVA-induced asthma.

CONCLUSIONS

LPS pre-treatment ameliorated mucus hypersecretion in an OVA-induced asthma model by inhibition of IL-13 production and by further inhibiting the JAK2/STAT6 pathway and ROS activity, and up-regulating expression of FOXA2.

Vitamin A maintains the airway epithelium in a murine model of asthma by suppressing glucocorticoid-induced leucine zipper

BACKGROUND

The effects of glucocorticoids (GCs) on the repair of the airway epithelium in asthma are controversial, and we previously reported that the GC dexamethasone (Dex) inhibits the repair of human airway epithelial cells and that this process is mediated by glucocorticoid-induced leucine zipper (GILZ) through MAPK-ERK signaling in vitro. Vitamin A (VA) is involved in the regulation of the MAPK-ERK pathway but has not been widely supplied during asthma treatment. It is unclear whether VA attenuates the negative regulation of GILZ on the MAPK-ERK pathway and maintains airway epithelium integrity during asthma treatment.

METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) and subsequently treated with Dex, VA or intranasal inhalation of adenovirus sh-GILZ vectors. Indexes of airway epithelium integrity, including pathological alterations, pulmonary EGFR expression and airway hyperresponsiveness (AHR), were then measured. The expression of GILZ and key components of activated MAPK-ERK signals (p-Raf-1, p-MEK, and p-Erk1/2) were also detected.

RESULTS

Dex failed to relieve OVA-induced asthma airway epithelium injury, as assessed through H&E staining, EGFR expression and AHR. Moreover, in the OVA-challenged mice treated with Dex, GLIZ expression was increased, whereas the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were significantly decreased. Further study indicated that GILZ expression was decreased and that the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were up-regulated in the GILZ-silenced OVA-challenged mice and VA-fed OVA-challenged mice, independent of Dex treatment. The airway epithelium integrity of the OVA-challenged mice was maintained by treatment with both VA and Dex.

CONCLUSIONS

Vitamin A maintained the Dex-treated asthma airway epithelium via the down-regulation of GILZ expression and the activation MAPK-ERK signaling, and these effects might contribute to improving the effects of GC therapeutics on asthma.

Human umbilical cord-derived mesenchymal stem cells protect from hyperoxic lung injury by ameliorating aberrant elastin remodeling in the lung of O2-exposed newborn rat

The incidence and mortality rates of bronchopulmonary dysplasia (BPD) remain very high. Therefore, novel therapies are imminently needed to improve the outcome of this disease. Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) show promising therapeutic effects on oxygen-induced model of BPD. In our experiment, UC-MSCs were intratracheally delivered into the newborn rats exposed to hyperoxia, a well-established BPD model. This study demonstrated that UC-MSCs reduce elastin expression stimulated by 90% O₂ in human lung fibroblasts-a (HLF-a), and inhibit HLF-a transdifferentiation into myofibroblasts. In addition, the therapeutic effects of UC-MSCs in neonatal rats with BPD, UC-MSCs could inhibit lung elastase activity and reduce aberrant elastin expression and deposition in the lung of BPD rats. Overall, this study suggested that UC-MSCs could ameliorate aberrant elastin expression in the lung of hyperoxia-induced BPD model which may be associated with suppressing increased TGFβ1 activation.

Reconciling agriculture, carbon and biodiversity in a savannah transformation frontier

Rapidly rising populations and likely increases in incomes in sub-Saharan Africa make tens of millions of hectares of cropland expansion nearly inevitable, even with large increases in crop yields. Much of that expansion is likely to occur in higher rainfall savannas, with substantial costs to biodiversity and carbon storage. Zambia presents an acute example of this challenge, with an expected tripling of population by 2050, good potential to expand maize and soya bean production, and large areas of relatively undisturbed miombo woodland and associated habitat types of high biodiversity value. Here, we present a new model designed to explore the potential for targeting agricultural expansion in ways that achieve quantitatively optimal trade-offs between competing economic and environmental objectives: total converted land area (the reciprocal of potential yield); carbon loss, biodiversity loss and transportation costs. To allow different interests to find potential compromises, users can apply varying weights to examine the effects of their subjective preferences on the spatial allocation of new cropland and its costs. We find that small compromises from the objective to convert the highest yielding areas permit large savings in transportation costs, and the carbon and biodiversity impacts resulting from savannah conversion. For example, transferring just 30% of weight from a yield-maximizing objective equally between carbon and biodiversity protection objectives would increase total cropland area by just 2.7%, but result in avoided costs of 27-47% for carbon, biodiversity and transportation. Compromise solutions tend to focus agricultural expansion along existing transportation corridors and in already disturbed areas. Used appropriately, this type of model could help countries find agricultural expansion alternatives and related infrastructure and land use policies that help achieve production targets while helping to conserve Africa's rapidly transforming savannahs.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.

Structural basis of respiratory syncytial virus subtype-dependent neutralization by an antibody targeting the fusion glycoprotein

A licensed vaccine for respiratory syncytial virus (RSV) is unavailable, and passive prophylaxis with the antibody palivizumab is restricted to high-risk infants. Recently isolated antibodies 5C4 and D25 are substantially more potent than palivizumab, and a derivative of D25 is in clinical trials. Here we show that unlike D25, 5C4 preferentially neutralizes subtype A viruses. The crystal structure of 5C4 bound to the RSV fusion (F) protein reveals that the overall binding mode of 5C4 is similar to that of D25, but their angles of approach are substantially different. Mutagenesis and virological studies demonstrate that RSV F residue 201 is largely responsible for the subtype specificity of 5C4. These results improve our understanding of subtype-specific immunity and the neutralization breadth requirements of next-generation antibodies, and thereby contribute to the design of broadly protective RSV vaccines.

Therapeutic Effects of Human Umbilical Cord-Derived Mesenchymal Stem Cells in Acute Lung Injury Mice

The incidence and mortality of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are still very high, but stem cells show some promise for its treatment. Here we found that intratracheal administration of human umbilical cord-mesenchymal stem cells (UC-MSCs) significantly improved survival and attenuated the lung inflammation in lipopolysaccharide (LPS)-induced ALI mice. We also used the proteins-chip and bioinformatics to analyze interactions between UC-MSCs treatment and immune-response alternations of ALI mice. Then we demonstrated that UC-MSCs could inhibit the inflammatory response of mouse macrophage in ALI mice, as well as enhance its IL-10 expression. We provide data to support the concept that the therapeutic capacity of UC-MSCs for ALI was primarily through paracrine secretion, particularly of prostaglandin-E2 (PGE2). Furthermore, we showed that UC-MSCs might secrete a panel of factors including GM-CSF, IL-6 and IL-13 to ameliorate ALI. Our study suggested that UC-MSCs could protect LPS-induced ALI model by immune regulation and paracrine factors, indicating that UC-MSCs should be a promising strategy for ALI/ARDS.

[Determination of relative elements of hard metal in workplace air and urine by inductive coupled plama]

Objective: To establish a rapid detection method regarding the air conditions of workplace and the workers' urine included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds based on inductively coupled plasma mass spectrometry (ICP-MS) . Methods: The experiment adopts ICP-MS to deter-mine those metals in workshop air and workers urine, evaluate the detection's limitation, the precision and accuracy of the method. Using the membrane filter and urine freeze - dried metal standard material to verify this method. Results: Each element of correlation coefficient was greater than 0.999. The recovery rate of air samples was 91.6%~104.6%, within-batch RSD precision was 1.41%~3.50%, between-run precision was 1.28%~4.31%, urine samples recovery rate was 93.0%~102.6%, within - batch RSD precision was 1.25%~3.56%, between - run precision was 1.58%~4.67%, According to the method every element was within the scope of the standard reference, it was also showed that the established method is accurate and reliable. Conclusion: ICP-MS is an effective and feasible method to detect the workshop air and the workers' urine which included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds.

A porcine reproductive and respiratory syndrome virus candidate vaccine based on the synthetic attenuated virus engineering approach is attenuated and effective in protecting against homologous virus challenge

Current porcine reproductive and respiratory syndrome virus (PRRSV) vaccines sometimes fail to provide adequate immunity to protect pigs from PRRSV-induced disease. This may be due to antigenic differences among PRRSV strains. Rapid production of attenuated farm-specific homologous vaccines is a feasible alternative to commercial vaccines. In this study, attenuation and efficacy of a codon-pair de-optimized candidate vaccine generated by synthetic attenuated virus engineering approach (SAVE5) were tested in a conventional growing pig model. Forty pigs were vaccinated intranasally or intramuscularly with SAVE5 at day 0 (D0). The remaining 28 pigs were sham-vaccinated with saline. At D42, 30 vaccinated and 19 sham-vaccinated pigs were challenged with the homologous PRRSV strain VR2385. The experiment was terminated at D54. The SAVE5 virus was effectively attenuated as evidenced by a low magnitude of SAVE5 viremia for 1-5 consecutive weeks in 35.9% (14/39) of the vaccinated pigs, lack of detectable nasal SAVE5 shedding and failure to transmit the vaccine virus from pig to pig. By D42, all vaccinated pigs with detectable SAVE5 viremia also had detectable anti-PRRSV IgG. Anti-IgG positive vaccinated pigs were protected from subsequent VR2385 challenge as evidenced by lack of VR2385 viremia and nasal shedding, significantly reduced macroscopic and microscopic lung lesions and significantly reduced amount of PRRSV antigen in lungs compared to the non-vaccinated VR2385-challenged positive control pigs. The nasal vaccination route appeared to be more effective in inducing protective immunity in a larger number of pigs compared to the intramuscular route. Vaccinated pigs without detectable SAVE5 viremia did not seroconvert and were fully susceptible to VR2385 challenge. Under the study conditions, the SAVE approach was successful in attenuating PRRSV strain VR2385 and protected against homologous virus challenge. Virus dosage likely needs to be adjusted to induce replication and protection in a higher percentage of vaccinated pigs.

[HER-2 expression and clinical significance in esophagogastric junction adenocarcinoma (Siewert type Ⅱ)]

OBJECTIVE

To investigate the human epidermal growth factor receptor-2 (HER-2) expression in esophagogastirc junction adenocarcinoma(Siewert type Ⅱ)and its clinical significance.

METHODS

A total of 180 patients with esophagogastric junction adenocarcinoma (Siewert type Ⅱ) were included in this study. The HER-2 expression was detected by immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) analysis was performed to assess the HER-2 gene amplification in the IHC-positive and IHC-weak positive cases.

RESULTS

HER-2 overexpression (3+ ), weak positive (2+ ) and negative (1+ /0) was 11.7%(21/180), 8.9%(16/180), and 79.4%(143/180), respectively. The FISH analysis showed HER-2 gene amplification in 95.2%(20/21) of HER-2(3+ ) cases and 18.8% (3/16) of HER-2(2+ ) cases. The concordance rate between IHC and FISH was 95.2%. Overexpression of HER-2(3+ ) was associated with the tumor differentiation (P<0.05), and irrelevant to age, sex, pT stage, pN stage, pM stage and pTNM stage (P>0.05). The median overall survival time (OS) was 13 months in HER-2(3+ ) patients, significantly shorter than the 21 months in HER-2(2+ ) and HER-2(+ /-) cases (P<0.01).

CONCLUSIONS

Approximately 11.7% of the patients with esophagogastric junction adenocarcinoma (Siewert type Ⅱ) are HER-2-positive on IHC. HER-2 overexpression is associated with the tumor differentiation. IHC can be used as a screening test for the positive expression of HER-2 in the esophagogastirc junction adenocarcinoma (Siewert type Ⅱ). However, FISH detection can be used as a more reliable detection method.