Revealing nitrogenous VX metabolites and the whole-molecule VX metabolism in the urine of guinea pigs

VX, a well-known organophosphorus nerve agent (OPNA), poses a significant threat to public safety if employed by terrorists. Obtaining complete metabolites is critical to unequivocally confirm its alleged use/exposure and elucidate its whole-molecular metabolism. However, the nitrogenous VX metabolites containing 2-diisopropylaminoethyl moiety from urinary excretion remain unknown. Therefore, this study applied a newly developed untargeted workflow platform to discover and identify them using VX-exposed guinea pigs as animal models. 2-(N,N-diisopropylamino)ethanesulfonic acid (DiPSA) was revealed as a novel nitrogenous VX metabolite in urine, and 2-(Diisopropylaminoethyl) methyl sulfide (DAEMS) was confirmed as another in plasma, indicating that VX metabolism differed between urine and plasma. It is the first report of a nitrogenous VX metabolite in urine and a complete elucidation of the VX metabolic pathway. DiPSA was evaluated as an excellent VX exposure biomarker. The whole-molecule VX metabolism in urine was characterized entirely for the first time via the simultaneous quantification of DiPSA and two known P-based biomarkers. About 52.1% and 32.4% of VX were excreted in urine as P-based and nitrogenous biomarkers within 24 h. These findings provide valuable insights into the unambiguous detection of OPNA exposure/intoxication and human and environmental exposure risk assessment.

[HVPG minimally invasive era: exploration based on forearm venous approach]

Objective: The transjugular or transfemoral approach is used as a common method for hepatic venous pressure gradient (HVPG) measurement in current practice. This study aims to confirm the safety and effectiveness of measuring HVPG via the forearm venous approach. Methods: Prospective recruitment was conducted for patients with cirrhosis who underwent HVPG measurement via the forearm venous approach at six hospitals in China and Japan from September 2020 to December 2020. Patients' clinical baseline information and HVPG measurement data were collected. The right median cubital vein or basilic vein approach for all enrolled patients was selected. The HVPG standard process was used to measure pressure. Research data were analyzed using SPSS 22.0 statistical software. Quantitative data were used to represent medians (interquartile ranges), while qualitative data were used to represent frequency and rates. The correlation between two sets of data was analyzed using Pearson correlation analysis. Results: A total of 43 cases were enrolled in this study. Of these, 41 (95.3%) successfully underwent HVPG measurement via the forearm venous approach. None of the patients had any serious complications. The median operation time for HVPG detection via forearm vein was 18.0 minutes (12.3~38.8 minutes). This study confirmed that HVPG was positively closely related to Child-Pugh score (r = 0.47, P = 0.002), albumin-bilirubin score (r = 0.37, P = 0.001), Lok index (r = 0.36, P = 0.02), liver stiffness (r = 0.58, P = 0.01), and spleen stiffness (r = 0.77, P = 0.01), while negatively correlated with albumin (r = -0.42, P = 0.006). Conclusion: The results of this multi-centre retrospective study suggest that HVPG measurement via the forearm venous approach is safe and feasible.

Endothelial depletion of Atg7 triggers astrocyte-microvascular disassociation at blood-brain barrier

Microvascular basement membrane (BM) plays a pivotal role in the interactions of astrocyte with endothelium to maintain the blood-brain barrier (BBB) homeostasis; however, the significance and precise regulation of the endothelial cell-derived BM component in the BBB remain incompletely understood. Here, we report that conditional knockout of Atg7 in endothelial cells (Atg7-ECKO) leads to astrocyte-microvascular disassociation in the brain. Our results reveal astrocytic endfeet detachment from microvessels and BBB leakage in Atg7-ECKO mice. Furthermore, we find that the absence of endothelial Atg7 downregulates the expression of fibronectin, a major BM component of the BBB, causing significantly reduced coverage of astrocytes along cerebral microvessels. We reveal Atg7 triggers the expression of endothelial fibronectin via regulating PKA activity to affect the phosphorylation of cAMP-responsive element-binding protein. These results suggest that Atg7-regulated endothelial fibronectin production is required for astrocytes adhesion to microvascular wall for maintaining the BBB homeostasis. Thus, endothelial Atg7 plays an essential role in astrocyte-endothelium interactions to maintain the BBB integrity.

Lpp of Escherichia coli K1 inhibits host ROS production to counteract neutrophil-mediated elimination

Escherichia coli (E. coli) is the most common Gram-negative bacterial organism causing neonatal meningitis. The pathogenesis of E. coli meningitis, especially how E. coli escape the host immune defenses, remains to be clarified. Here we show that deletion of bacterial Lpp encoding lipoprotein significantly reduces the pathogenicity of E. coli K1 to induce high-degree of bacteremia necessary for meningitis. The Lpp-deleted E. coli K1 is found to be susceptible to the intracellular bactericidal activity of neutrophils, without affecting the release of neutrophil extracellular traps. The production of reactive oxygen species (ROS), representing the primary antimicrobial mechanism in neutrophils, is significantly increased in response to Lpp-deleted E. coli. We find this enhanced ROS response is associated with the membrane translocation of NADPH oxidase p47^phox and p67^phox in neutrophils. Then we constructed p47^phox knockout mice and we found the incidence of bacteremia and meningitis in neonatal mice induced by Lpp-deleted E. coli is significantly recovered by p47^phox knockout. Proteomic profile analysis show that Lpp deficiency induces upregulation of flagellar protein FliC in E. coli. We further demonstrate that FliC is required for the ROS induction in neutrophils by Lpp-deleted E. coli. Taken together, these data uncover the novel role of Lpp in facilitating intracellular survival of E. coli K1 within neutrophils. It can be inferred that Lpp of E. coli K1 is able to suppress FliC expression to restrain the activation of NADPH oxidase in neutrophils resulting in diminished bactericidal activity, thus protecting E. coli K1 from the elimination by neutrophils.

[Percutaneous biliary stent combined with brachytherapy for malignant obstructive jaundice: a multicenter retrospective controlled study]

Objective: To investigate the efficacy, safety and prognostic factors of percutaneous biliary stent combined with iodine-125 seed chain brachytherapy (radiotherapy) in the treatment of malignant obstructive jaundice. Methods: Data of 107 cases with malignant obstructive jaundice treated with percutaneous biliary stent implantation from January 2017 to December 2020 were retrospectively analyzed. Among them, 58 cases received biliary stent combined with iodne-125 seed chain brachytherapy (study group), and 49 cases received biliary stent implantation (control group). The changes of bilirubin, stent patency time, complications, overall survival (OS) and prognostic factors were analyzed in both groups. Results: The incidence of complications in the study group and the control group were 17.2% and 18.3% respectively, and the difference was not statistically significant (P=0.974). Serum total bilirubin levels were decreased significantly in both groups at one month after surgery (P<0.001). Postoperative stent patency time was significantly better in the study group (10.0±1.6 months) (95% CI: 8.2～12.5) than that in the control group (5.2±0.4 months) (95% CI: 4.1～6.0, P<0.001). The median OS was longer in the study group (11.2±1.8 months) (95% CI: 9.2～12.8) than that in the control group (8.0±1.1 months) (95% CI: 8.0～12.8, P<0.001). Multivariate analysis result showed that stent combined with brachytherapy (HR=0.08, 95% CI:0.04～0.15, P<0.001) and receiving further anti-tumor therapy after surgery (HR=0.27, 95% CI:0.15~0.49, P<0.001) were independent risk factors affecting the patency of biliary stents. Preoperative percutaneous transhepatic biliary drainage (HR=0.46, 95%CI:0.28～0.74, P=0.002), stent combined with brachytherapy (HR=0.23, 95%CI:0.14～0.39, P<0.001) and receiving further anti-tumor therapy after surgery (HR=0.37, 95%CI:0.22～0.61, P<0.001) were independent risk factors affecting OS. Conclusion: Percutaneous biliary stent combined with brachytherapy is safe and effective in the treatment of malignant obstructive jaundice, which can significantly prolong the patency time of biliary stent and the survival time of patients.

[Interpretation of the American Association for Thoracic Surgery expert consensus document: coronary artery bypass grafting in patients with ischemic cardiomyopathy and heart failure in 2021]

An expert consensus on coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy (ICM) was released by the American Association for Thoracic Surgery in May 2021, which contains a vast array of perioperative recommendations. During preoperative period, a comprehensive assessment on ICM including myocardial viability and valve function by a multi-disciplinary team (MDT) approach should be performed. In terms of intraoperative period, multiple arterial conduits and on-pump CABG using cold blood cardioplegia should be considered, meanwhile, other aspects involving concomitant management of mitral valve regurgitation and arrythmia, as well as active use of mechanical cardiac assist devices (e.g., intra-aortic balloon pump) should also be achieved. Finally, a range of postoperative interventions which includes standardized MDT management in intensive care unit (ICU), continuous use of cardiac assist devices, cardiac pacing, close follow-up within 90 days and drug treatment strictly guided by the guidelines after discharge from hospital should be conducted. The above-mentioned perioperative bundled care might reduce perioperative complications and operative mortality, and thus improve the prognosis of the patients with ICM.

Nontuberculous mycobacteria in China: incidence and antimicrobial resistance spectrum from a nationwide survey

Background

Information on the prevalence and resistance spectrum of nontuberculous mycobacteria (NTM) in China is mainly based on regional or local data. To estimate the proportion of NTM cases in China, a national survey of NTM pulmonary disease was carried out based on acid-fast positive sputum samples collected in 2013.

Methods

Sputum samples collected from enrolled presumptive cases in 72 nationwide tuberculosis surveillance sites from the 31 provinces in the mainland of China were cultured using L-J medium at the National tuberculosis reference laboratory (NTRL). MALDI-TOF MS identified the species of re-cultured strains, and minimal inhibitory concentrations (MICs) were determined to evaluate the drug susceptibility of NTM isolates. Data analysis used statistical software SPSS version 22.0 for Windows statistical package.

Results

Of 4917 mycobacterial isolates cultured, 6.4% [317/4917, 95% confidence interval (CI) 5.8%–7.2%] were confirmed as NTM, among which 7.7% (287/3709, 95% CI 6.9%–8.6%) were from the southern region. In inland and coastal China, 87.7% (95% CI 78.7%–93.2%) and 50.0% (95% CI 43.7%–56.3%) of isolates, respectively, were slow-growing mycobacteria (SGM), with the remaining rapid growing mycobacteria (RGM). A total of 29 species were detected, Mycobacterium abscessus had higher clarithromycin-inducible resistance rates than M. massiliense (65.67% vs 2.22%). M. kansasii presented lower resistance rates in linezolid and moxifloxacin than M. avium-intracellulare complex (3.23% vs 66.67%, 0 vs 47.22%) and other SGM (3.23% vs 38%, 0 vs 26%).

Conclusions

More NTM pulmonary disease was observed in the south and coastal China (P < 0.01). SGM was widely distributed, and more RGM are present in southern and coastal China (P < 0.01). The antimicrobial resistance spectrum of different NTM species was significantly different and accurate species identification would be facilitated to NTM pulmonary disease treatment.

[Current status and controversy of neoadjuvant therapy in pancreatic cancer]

Pancreatic cancer is considered to be the most malignant digestive tract tumor due to its high invasiveness, metastasis and recurrence rate. In recent years, neoadjuvant therapy has brought new insights to the treatment of pancreatic cancer. To date, the value of neoadjuvant therapy in pancreatic cancer has been widely recognized, but there is a lack of specific regimens. The superiority and inferiority of various regimens are still uncertain, therefore, the efficacy of neoadjuvant therapy can be evaluated combined with imaging, functional and biological markers.

Relationship between polyamines conjugated to mitochondrion membrane and mitochondrion conformation from developing wheat embryos under drought stress

The mitochondrion conformation and the contents of conjugated polyamines were investigated using the embryos of developing wheat (Triticum aestivum L.) grains of two cultivars differing in drought tolerance as experiment materials. After drought stress treatment for 7 days, the relative water content of embryo and relative increase rate of embryo dry weight of the drought-sensitive Yangmai No. 9 cv. decreased more significantly than those of the drought-tolerant Yumai No. 18 cv. Furthermore, the changes in mitochondrion conformation of Yangmai No. 9 were more marked. Meanwhile, the increases of the contents of conjugated non-covalently spermidine (CNC-Spd) and conjugated covalently putrescine (CC-Put) of Yumai No. 18 were more obvious than those of Yangmai No. 9. Treatment with exogenous Spd not only alleviated the injury of drought stress to Yangmai No. 9, but also enhanced the increase of CNC-Spd content and inhibited the change in the mitochondrion conformation of this cultivar. The treatments of Yumai No. 18 with two inhibitors, methylglyoxyl-bis (guanylhydrazone) and phenanthrolin, significantly inhibited the drought stress-induced increases of CNC-Spd and CC-Put contents of the cultivar, respectively. Meanwhile, the treatments with the two inhibitors aggravated the injury of drought stress to Yumai No. 18 and enhanced the change in the mitochondrion conformation of this cultivar. These results mentioned above suggested that the CNC-Spd and CC-Put in embryo mitochondrion membrane isolated from developing grains could enhance the wheat tolerance to drought stress by maintaining the mitochondrion conformation.

Caspr1 Facilitates sAPPα Production by Regulating α-Secretase ADAM9 in Brain Endothelial Cells

The expression of contactin-associated protein 1 (Caspr1) in brain microvascular endothelial cells (BMECs), one of the major cellular components of the neurovascular unit (NVU), has been revealed recently. However, the physiological role of Caspr1 in BMECs remains unclear. We previously reported the nonamyloidogenic processing of amyloid protein precursor (APP) pathway in the human BMECs (HBMECs). In this study, we found Caspr1 depletion reduced the levels of soluble amyloid protein precursor α (sAPPα) in the supernatant of HBMECs, which could be rescued by expression of full-length Caspr1. Our further results showed that ADAM9, the α-secretase essential for processing of APP to generate sAPPα, was decreased in Caspr1-depleted HBMECs. The reduced sAPPα secretion in Caspr1-depleted HBMECs was recovered by expression of exogenous ADAM9. Then, we identified that Caspr1 specifically regulates the expression of ADAM9, but not ADAM10 and ADAM17, at transcriptional level by nuclear factor-κB (NF-κB) signaling pathway. Caspr1 knockout attenuated the activation of NF-κB and prevented the nuclear translocation of p65 in brain endothelial cells, which was reversed by expression of full-length Caspr1. The reduced sAPPα production and ADAM9 expression upon Caspr1 depletion were effectively recovered by NF-κB agonist. The results of luciferase assays indicated that the NF-κB binding sites are located at −859 bp to −571 bp of ADAM9 promoter. Taken together, our results demonstrated that Caspr1 facilitates sAPPα production by transcriptional regulation of α-secretase ADAM9 in brain endothelial cells.

[Etiological analysis of hepatopathy of unknown etiology in 470 cases undergoing routine liver biopsy examination]

Objective: To understand the etiology of hepatopathy of unknown etiology in patients undergoing liver biopsy. Methods: Demographic data and pathological examination reports of patients with hepatopathy of unknown etiology who underwent liver biopsy examination at outpatient and inpatient of the Second Hospital of Nanjing between January 2017 and June 2018 were retrospectively collected. All liver histopathological sections combined with clinical and pathological features based on liver biopsy examinations were diagnosed by a reputed clinician and a pathologist. Results: A total of 470 cases with hepatopathy of unknown etiology who underwent liver biopsy were enrolled. Of these, 425 cases (90.4%) had a definite diagnosed disease after comprehensive analysis of pathological and clinical data. The diagnosis of hepatopathy of unknown etiology included 11 diseases: 90 cases with autoimmune hepatitis had autoimmune liver disease (19.1%), 38 cases had primary biliary cholangitis (8.1%), 43 cases with overlap syndrome of autoimmune hepatitis had primary biliary cholangitis (9.1%), 118 cases had drug-induced liver injury (25.1%), 75 cases had nonalcoholic fatty liver disease (NAFLD) (16.0%), 12 cases had alcoholic liver disease (2.6 cases) %), 15 cases (3.2%) had vascular liver disease, 7 cases (1.5%) had hereditary metabolic liver disease, 5 cases (1.1%) had other systemic diseases, 16 cases (3.4%) had more than two kinds of liver diseases, and 6 cases (1.3%) had others rare liver diseases. Conclusion: Over 90% cause of the hepatopathy of unknown etiology in the long run can be determined, and the main causes are autoimmune liver disease, drug-induced liver injury, and nonalcoholic fatty liver disease, which needs multidisciplinary cooperation to diagnose, and clinicians need to master the basic and clinical knowledge of liver diseases as well as liver pathology, hepatobiliary imaging, and genetics.

Atg7 Silencing Inhibits Laminin-5 Expression to Suppress Tube Formation by Brain Endothelial Cells

Cerebral angiogenesis is a key event during brain development and recovery from brain injury. We previously demonstrated that Atg7 knockout impaired angiogenesis in the mouse brain. However, the role of Atg7 in angiogenesis is not completely understood. In this study, we used human brain microvascular endothelial cells (HBMECs) to investigate the mechanism of Atg7-regulated cerebral angiogenesis. We found that Atg7 depletion specifically diminished the expression of the β3 and γ2 chains of laminin-5, a major component of the extracellular matrix. In contrast, autophagy inhibitors did not affect laminin-5 expression, suggesting that Atg7-regulated laminin-5 expression is autophagy-independent. We also found that Atg7-regulated laminin-5 expression occurred at the transcriptional level through NF-κB signaling. Exogenous laminin-5 or the NF-κB agonist betulinic acid effectively rescued tube formation by Atg7-deficient HBMECs. Taken together, our study identified a novel mechanism by which Atg7 regulates laminin-5 expression via NF-κB to modulate tube formation by brain endothelial cells during cerebral angiogenesis. Anat Rec, 302:2255-2260, 2019. © 2019 American Association for Anatomy.

[Mid-term outcomes of coronary artery bypass surgery with left radial artery bypassed to right main coronary artery of severe stenosis]

Objective: To evaluate the mid-term outcomes of coronary artery bypass grafting (CABG) with left radial artery (RA) graft bypassed to right main coronary artery (RCA) of severe stenosis. Methods: Between September 2014 and April 2019, a total of consecutive 47 patients who had severe stenosis (≥90%) of RCA underwent total arterial revascularization, with left RA bypassed to RCA. There were 31 males and 16 females, with a mean age of (56.5±9.7) years old. The perioperative outcomes were observed and mid-term results were followed up. Results: A total of 46 left internal mammary artery (LIMA) grafts, 47 left radial artery (LRA), and 40 right RA grafts (RRA) were harvested with pedicles. LIMA was bypassed to LAD in 43 patients, RRA was to diagonal branches, ramus or oblique marginal in 37 cases, and LRA was to RCA. All grafts (except 3 composite Y or T grafts) were single. Mean graft number was 2-4 (2.7±0.9). There was one death due to cardiac tamponade. Three patients had postoperative atrial fibrillation, 1 had a forearm hematoma, 1 had acute renal insufficiency, and 2 had acute myocardial infarction. The mean tracheal intubation duration was 3.5-20.3 (8.3±4.7) hours, and the mean hospital stay was 6-13 (7.1±2.9) days. The average follow-up was 3-47 (23.3±7.5) months, with a follow-up rate of 86.96% (40/46). There were no major cardiovascular events during the follow-up. Three month after surgery, the mean left ventricular ejection fraction was significantly improved than that of pre-operation (60.0%±4.0% vs 42.4%±7.5%, P=0.003). Computed tomography angiography (CTA) examination showed that 58.7% (27/46) of patients had patent LRA after a mean follow-up duration of (19.5±7.3) months. Conclusion: CABG with LRA bypassed to RCA of severe stenosis proves to be safe and effective, with good mid-term outcomes.

[The effects of wireless audio microphones on sentences recognition threshold for hearing aid users in noise]

Objective:This study was aimed to observe the effects of wireless audio microphone on hearing aids effect in noise at different listening distances. Method:Twenty-three subjects with bilateral sensorineural hearing loss, including 17 males and 6 females were fitted with binaural hearing aids. These patients did sentences recognition tests at two different listening distance（1.5 and 3 meters） in noise. The subjects were tested under three conditions, ①with hearing aids alone; ②with the wireless audio microphone alone; ③with hearing aid microphone and mini audio microphone simultaneously. Result:The sentence recognition threshold at 3 meters listening distance is significantly higher than it at 1.5 meters listening distance with hearing aids alone（P<0.05）. There is no significant difference in the sentence recognition threshold between two listening distances when the wireless audio microphone was switched on（P>0.05）. Conclusion:Mini audio microphone can significantly improve hearing aids effect in long distance listening in noise.

A CASPR1-ATP1B3 protein interaction modulates plasma membrane localization of Na+/K+-ATPase in brain microvascular endothelial cells

Contactin-associated protein 1 (CASPR1 or CNTNAP1) was recently reported to be expressed in brain microvascular endothelial cells (BMECs), the major component of the blood-brain barrier. To investigate CASPR1's physiological role in BMECs, here we used CASPR1 as a bait in a yeast two-hybrid screen to identify CASPR1-interacting proteins and identified the β3 subunit of Na⁺/K⁺-ATPase (ATP1B3) as a CASPR1-binding protein. Using recombinant and purified CASPR1, RNAi, GST-pulldown, immunofluorescence, immunoprecipitation, and Na⁺/K⁺-ATPase activity assays, we found that ATP1B3's core proteins, but not its glycosylated forms, interact with CASPR1, which was primarily located in the endoplasmic reticulum of BMECs. CASPR1 knockdown reduced ATP1B3 glycosylation and prevented its plasma membrane localization, phenotypes that were reversed by expression of full-length CASPR1. We also found that the CASPR1 knockdown reduces the plasma membrane distribution of the α1 subunit of Na⁺/K⁺-ATPase, which is the major component assembled with ATP1B3 in the complete Na⁺/K⁺-ATPase complex. The binding of CASPR1 with ATP1B3, but not the α1 subunit, indicated that CASPR1 binds with ATP1B3 to facilitate the assembly of Na⁺/K⁺-ATPase. Furthermore, the activity of Na⁺/K⁺-ATPase was reduced in CASPR1-silenced BMECs. Interestingly, shRNA-mediated CASPR1 silencing reduced glutamate efflux through the BMECs. These results demonstrate that CASPR1 binds with ATP1B3 and thereby contributes to the regulation of Na⁺/K⁺-ATPase maturation and trafficking to the plasma membrane in BMECs. We conclude that CASPR1-mediated regulation of Na⁺/K⁺-ATPase activity is important for glutamate transport across the blood-brain barrier.

[Study on spectrum of UGT1A1 mutations in connection with inherited non-hemolytic unconjugated hyperbilirubinemia]

Objective: To compare and analyze patient's general condition, changes in laboratory parameters, and the spectrum of UGT1A1 mutations in patients with inherited non-hemolytic unconjugated hyperbilirubinemia. Methods: A retrospective study was conducted at Nanjing Second Hospital from January 2015 to July 2018 and patients' demographic characteristics, liver function test, and UGT1A1 gene were analyzed. The categorical variable data were compared by χ (2) test. The normal distribution continuous variable data were compared by t-test and the non-normal distribution continuous variable data were compared using Mann-Whitney U test. Results: Of the 51 patients with inherited non-hemolytic unconjugated hyperbilirubinemia, 44 (86.3%) were Gilbert's syndrome (GS) and seven (13.7%) were Crigler-Najjar syndrome type II (CNS- II). The male to female ratio was 2.9:1 and the average age was 36.11 ± 13.17 years. Six variant types were detected: C. -40_-39insTA, C. -3279T > G, c.211G > A (p.G71R), c.686C > A (p.P229Q), c.1091C > T (p.P364L), c.1456T > G (P.Y486D). Among them, c.211G > A accounted for 58.82% (30/51), c.-40_-39insTA accounted for 27.5% (14/51), and c.1456T > G accounted for 25.5% (13/51). The total bilirubin(TB) and unconjugated bilirubin (UCB) in CNS-II patients were significantly higher than GS patients[155.91 (130 ~ 207) vs. 38.25(29 ~ 52.15) μmol/L, U = 0, P < 0.01; 144.13 (120.8 ~ 197) vs. 30.00 (21.7 ~ 46.75) μmol/L, U = 0.00, P < 0.01, respectively]. Exon mutations of c.1091C > T and c.1456T > G were statistically significant(P < 0.01).There were no differences in age, TB, UCB, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) between the c.211G > A homozygous variants and heterozygous variants (P > 0.05). Conclusion: The common pathogenic mutations of UGT1A1 gene were c.211G > A, c.-40_-39insTA, c.1456T > G. c.211G > A. The mutation has little effect on the level of total bilirubin, but c.1091C > T, c.1456T > G mutations has great influence on the level of total bilirubin.

Endothelial Atg7 Deficiency Ameliorates Acute Cerebral Injury Induced by Ischemia/Reperfusion

Ischemic strokes often result in cerebral injury due to ischemia/reperfusion (I/R). Although the local inflammatory responses are known to play a primary role in the brain I/R injury, the underlying mechanism remains unclear. In the current study, we investigated the effect of brain endothelial Atg7 (autophagy related 7) depletion in the acute brain injury induced by ischemia and reperfusion. Endothelial knockout of Atg7 in mice (Atg7 eKO) was found to significantly attenuate both the infarct volume and the neurological defects induced by I/R when compared to the controls. In fact, brain inflammatory responses induced by I/R were alleviated by the Atg7 eKO. Furthermore, an increased expression of pro-inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α, was observed in brain endothelial cells in response to oxygen/glucose depletion/reoxygenation, which was decreased by the shRNA-mediated Atg7 knockdown. Interestingly, Atg7 knockdown reduced IKKβ phosphorylation, leading to NF-κB deactivation and downregulation of the pro-inflammatory cytokines mRNA levels. Further, Atg7 transcriptional regulation function is independent of its role in autophagy. Taken together, our results demonstrated that brain endothelial Atg7 contributes to brain damage during I/R by modulating the expression of pro-inflammatory cytokines. Depletion of Atg7 in brain endothelium has a neuroprotective effect against the ischemia/reperfusion-induced acute cerebral injury during stroke.

Relationship between sleep disorders and lymphocyte subsets and cytokines in patients with lung cancer

This study aimed to investigate the relationship between sleep disorders and lymphocyte subsets and cytokines in patients with lung cancer undergoing radiotherapy, and to establish a theoretical foundation for predicting sleep disorders and preventing interventions in radiotherapy in lung cancer patients. Ninety-two patients with lung cancer requiring radiotherapy were selected as the study subjects. The patients' demographic data and disease-related conditions were investigated. Their quality of sleep was measured before radiotherapy, after two and four weeks of radiotherapy, and at the end of radiotherapy. According to the Pittsburgh Sleep Quality Index Number Table (PSQI), patients with PSQI score> 7 points were put into a sleep disorder group, and patients with PSQI score 0-7 were put into a normal sleep group. Lymphocyte subsets were enumerated and cytokine levels (IL-6, IL-1b) were measured during these four periods. The difference in sleep disorders at four weeks between patients with or without synchronous chemotherapy was statistically significant (P less than 0.05). The levels of lymphocyte subsets in the sleep disorder group and the control sleep group showed no difference in the index of lymphocyte subsets before radiotherapy. In the sleep disorder group, CD4+ cells were lower after two weeks of radiotherapy (P less than 0.05). After four weeks of radiotherapy, CD3+, CD4+, and CD16+56+ subsets were lower (P less than 0.05). At the end of radiotherapy, there was no difference in each index. There was no significant difference in IL-6 levels between the two groups before radiotherapy, after two weeks, or after four weeks (P greater than 0.05). At the end of radiotherapy, IL-6 levels in the sleep disorder group were higher than those in the control sleep group (P less than 0.05). There was no significant difference in IL-1b between the two groups (P greater than 0.05). In conclusion, monitoring of T-lymphocyte subsets and IL-6 levels in patients is enhanced during radiotherapy. Clinically effective programs of radiotherapy for lung cancer improve the body's immune status.

Escherichia coli hijack Caspr1 receptor to invade cerebral vascular and neuronal hosts

Escherichia coli (E. coli) penetration of the blood-brain barrier (BBB) is the key step essential for the development of meningitis. In a recent paper (Nat Commun 9:2296), we identify Caspr1 as a host receptor for E. coli virulence factor IbeA to pave the way the penetration of bacteria through the BBB. Bacterial IbeA interacts with endothelial Caspr1 to trigger intracellular focal adhesion kinase activation, leading to E. coli internalization into the brain endothelial cells. Importantly, endothelial knockout of Caspr1 in mice significantly reduced E. coli crossing through the BBB. Based on the results that extracellular aa 203-355 of Caspr1 bind with IbeA, we tested the blocking effect of recombinant Caspr1(203-355) peptides in neonatal rat model of meningitis. The results showed that Caspr1(203-355) peptides effectively attenuated E. coli penetration into the brain during meningitis, indicating that Caspr1(203-355) peptides could be used to neutralize the virulent IbeA to prevent meningitis. We further found that E. coli can directly invade into hippocampal neurons causing apoptosis which required the interaction between bacterial IbeA and neuronal Caspr1. These findings demonstrate that E. coli hijack Caspr1 as a host receptor for penetration of BBB and invasion of hippocampal neurons, resulting in progression of meningitis.

Caspr1 is a host receptor for meningitis-causing Escherichia coli

Escherichia coli is the leading cause of neonatal Gram-negative bacterial meningitis, but the pathogenesis of E. coli meningitis remains elusive. E. coli penetration of the blood–brain barrier (BBB) is the critical step for development of meningitis. Here, we identify Caspr1, a single-pass transmembrane protein, as a host receptor for E. coli virulence factor IbeA to facilitate BBB penetration. Genetic ablation of endothelial Caspr1 and blocking IbeA–Caspr1 interaction effectively prevent E. coli penetration into the brain during meningitis in rodents. IbeA interacts with extracellular domain of Caspr1 to activate focal adhesion kinase signaling causing E. coli internalization into the brain endothelial cells of BBB. E. coli can invade hippocampal neurons causing apoptosis dependent on IbeA–Caspr1 interaction. Our results indicate that E. coli exploits Caspr1 as a host receptor for penetration of BBB resulting in meningitis, and that Caspr1 might be a useful target for prevention or therapy of E. coli meningitis.

Penetration of the blood–brain barrier (BBB) is crucial for development of E. coli-caused meningitis. Here, the authors show that a host membrane protein, Caspr1, acts as a receptor for a bacterial virulence factor to facilitate BBB penetration and entry of E. coli into brain neurons.

Experimental Evidence of Kinetic Effects in Indirect-Drive Inertial Confinement Fusion Hohlraums

We present the first experimental evidence supported by simulations of kinetic effects launched in the interpenetration layer between the laser-driven hohlraum plasma bubbles and the corona plasma of the compressed pellet at the Shenguang-III prototype laser facility. Solid plastic capsules were coated with carbon-deuterium layers; as the implosion neutron yield is quenched, DD fusion yield from the corona plasma provides a direct measure of the kinetic effects inside the hohlraum. An anomalous large energy spread of the DD neutron signal (∼282  keV) and anomalous scaling of the neutron yield with the thickness of the carbon-deuterium layers cannot be explained by the hydrodynamic mechanisms. Instead, these results can be attributed to kinetic shocks that arise in the hohlraum-wall-ablator interpenetration region, which result in efficient acceleration of the deuterons (∼28.8  J, 0.45% of the total input laser energy). These studies provide novel insight into the interactions and dynamics of a vacuum hohlraum and near-vacuum hohlraum.

Surgical reconstruction of the fascia lata and posterior tibial artery perforator flap to treat children with simultaneous injury to the Achilles tendon and heel skin

Children with simultaneous injury to the Achilles tendon and heel skin remain a challenge for clinicians. The purpose of this study is to evaluate a combined surgical procedure involving use of the fascia lata to reconstruct the Achilles tendon, and the posterior tibial artery perforator flap to cover the accompanying heel skin injury.Between February 2010 and February 2013, 8 children (3 females and 5 males) between 3 and 12 years of age, with a median age of 7.5 years, were hospitalized in the First Affiliated Hospital of Shantou University Medical College. All injuries involved damage to an Achilles tendon and heel skin. In all patients, the fascia lata was transplanted to reconstruct the Achilles tendon and the posterior tibial artery perforator flap transplanted to cover the skin injury.Hospitalization was 11 to 15 days (mean 13.5 days). Local necrosis (15% of the area) occurred in 1 flap, but healed after changing dressing. All other flaps survived well. At follow-up after 1 to 2 years, all children had recovered good plantar-flexion and supported their weight while walking. Use of the Arner-Lindholm standard to rate clinical efficacy revealed that of the 8 cases, 6 cases showed excellent recovery and 2 were good, with 0 cases ranking moderate or poor. The excellent and good rate was 100%.Child patients with Achilles tendon injury accompanied by heel skin injury are still a challenge for clinicians. Use of the fascia lata, combined with a posterior tibial artery perforator flap, to reconstruct the Achilles tendon and heel skin for children is a feasible, safe, effective method, faster than other methods for recovery, and should be widely applied in the clinic.

[Determination of Methcathinone in Urine by GC-MS]

OBJECTIVES

To establish a method for the analysis of methcathinone in urine by gas chromatography-mass spectrometry （GC-MS）.

METHODS

Proadifen hydrochloride （internal standard） and buffer solution （pH=9） were added into the urine samples, and methcathinone was extracted by ethyl acetate. The extract was volatilized in 50 ℃ nitrogen gas flow and the remnant was dissolved by methanol and analysed by GC-MS.

RESULTS

The methcathinone in urine showed a good linear relationship in the mass concentration range of 0.02-2.00 μg/mL. The linear equation was y=0.301 9 x+0.018 9 （r=0.999 2）, and the detection limit was 0.01 μg/mL. The recoveries of methcathinone in urine was 96.4%-99.2%, with the intra-day precision of 5.8%-7.6% and the inter-day precision of 6.0%-8.1%.

CONCLUSIONS

The method is convenient and sensitive, which can be applied to the forensic identification of methcathinone in urine.

[Age dependent changes in mandarin speech perception in normal hearing people]

Objective:To investigate if and when the mandarin speech perception ability deteriorates with age in adults with audiometrically normal hearing sensitivity.Method:The participant group included 75 normal hearing adults sampled from across the entire range of adulthood, of which there are 20 males and 55 femals. The participants were divided into 5 groups with 15 participants per age group: 20-30 years, 31-40 years, 41-50 years, 51-60 years, and 61-70 years. We applied speech perception test using Mandarin Hearing in Noise Test.Result:The speech perception scores were significantly different among the five groups in 0 dB and -5 dB conditions (P<0.001), but they weren't significantly different among the five groups in quiet, 10 dB and 5 dB (P>0.005).There was a significant negative correlation between speech perception and age in -5 dB conditions.Conclusion:When the background noise becomes more severe even for participants with audiomerically normal hearing, it was shown that speech perception declined with age.

[The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]

OBJECTIVE

To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations.

METHODS

In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015.

RESULTS

As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study.

CONCLUSIONS

INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.

The antitumor efficacy of anti-p21Ras scFv mediated by the dual-promoter-regulated recombinant adenovirus KGHV300

Ras mutations and overexpression of the Ras protein, p21Ras, are main causes of cancer development and progression, which has made the Ras gene and p21Ras important targets for therapy of Ras-driven cancers. We previously prepared recombinant adenovirus KGHV100 based on replication-defective adenovirus type 5, which could intracellularly express anti-p21Ras single chain fragment viable antibodies (scFv) and repress tumor growth in vitro and in vivo. However, the anti-tumor effects of this anti-p21Ras scFv were limited by short-term scFv expression due to a replication defect of KGHV100. To enhance the anti-tumor efficacy and safety of anti-p21Ras scFv, the present study constructed a dual-promoter-regulated recombinant adenovirus KGHV300 that carried anti-p21Ras scFv. In KGHV300, the expression levels of the essential replication genes E1a and E1b, were controlled by the human telomerase reverse transcriptase promoter and the hypoxia response element, respectively, and the anti-p21Ras scFv gene was controlled by the cytomegalovirus promoter. The conditional replication of KGHV300 and its antitumor efficacy were characterized in several tumor cell lines in vitro and in xenograft models of human breast cancer in nude mice. TCID50 assay demonstrated that KGHV300 could replicate in tumor cell lines but not in normal cell lines. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay indicated that the growth of tumor cells was effectively inhibited by KGHV300 infection. In MDA-MB-231 tumor xenograft models, KGHV300 effectively and significantly inhibited tumor growth and induced apoptosis of tumor cells. We concluded that the recombinant adenovirus KGHV300 may be a more potent and safer antitumor therapeutic for Ras-driven cancer biotherapy.

Cystatin C Shifts APP Processing from Amyloid-β Production towards Non-Amyloidgenic Pathway in Brain Endothelial Cells

Amyloid-β (Aβ), the major component of neuritic plaques in Alzheimer's disease (AD), is derived from sequential proteolytic cleavage of amyloid protein precursor (APP) by secretases. In this study, we found that cystatin C (CysC), a natural cysteine protease inhibitor, is able to reduce Aβ40 secretion in human brain microvascular endothelial cells (HBMEC). The CysC-induced Aβ40 reduction was caused by degradation of β-secretase BACE1 through the ubiquitin/proteasome pathway. In contrast, we found that CysC promoted secretion of soluble APPα indicating the activated non-amyloidogenic processing of APP in HBMEC. Further results revealed that α-secretase ADAM10, which was transcriptionally upregulated in response to CysC, was required for the CysC-induced sAPPα secretion. Knockdown of SIRT1 abolished CysC-triggered ADAM10 upregulation and sAPPα production. Taken together, our results demonstrated that exogenously applied CysC can direct amyloidogenic APP processing to non-amyloidgenic pathway in brain endothelial cells, mediated by proteasomal degradation of BACE1 and SIRT1-mediated ADAM10 upregulation. Our study unveils previously unrecognized protective role of CysC in APP processing.

miR-96 inhibits cardiac hypertrophy by targeting growth factor receptor-bound 2

Increasing evidence has indicated that microRNAs are involved in the pathogenesis of cardiac hypertrophy. However, whether miR-96 is involved in heart diseases, particularly cardiac hypertrophy, remains unclear. In this study, we found that miR-96 is a negative regulator of cardiac hypertrophy. In primary cardiomyocytes, overexpression of miR-96 inhibited phenylephrine-induced cardiomyocyte hypertrophy and decreased the mRNA expression of cardiac hypertrophy markers such as atrial natriuretic factor and β-myosin heavy chain. Interestingly, we found that growth factor receptor-bound 2 is a direct target of miR-96, which is a negative regulator of cardiac hypertrophy. Overexpression of miR-96 in cardiomyocytes led to reduced growth factor receptor-bound 2 expression. More importantly, miR-96 repressed the extracellular-regulated protein kinase signaling pathway by targeting growth factor receptor-bound 2 in cardiomyocytes. Our data demonstrate that miR-96 is a negative regulator of cardiac hypertrophy and extracellular-regulated protein kinase signaling, thus offering a new therapeutic strategy for cardiac hypertrophy.

Decreased expression of cathepsin D in monocytes is related to the defective degradation of amyloid-β in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative dementia characterized by pathological senile plaques composed of amyloid-β (Aβ) in the cerebral cortex and hippocampus. Bone marrow-derived monocytes of patients with AD migrate across the blood-brain barrier into the brain, but are defective at clearing Aβ in the neuritic plaques. However, the underlying mechanisms remain unclear. Here, in patients with AD, we found that cathepsin D, a major lysosomal aspartic protease, was underexpressed in monocytes, resulting in the defective degradation of Aβ by monocytes/macrophages. Further, downregulation of cathepsin D in THP-1 cells significantly reduced the clearance of amyloid plaques in the brain sections of AβPP/PS1 mice. The clearance ability was recovered by the overexpression of cathepsin D in AD monocytes. These results suggest that decreased expression of cathepsin D in the peripheral monocytes is a potential signature of AD, and that this decreased expression is involved in Aβ degradation and AD pathogenesis.

Optimizing the electrical excitation of an atmospheric pressure plasma advanced oxidation process

The impact of pulse-modulated generation of atmospheric pressure plasma on the efficiency of organic dye degradation has been investigated. Aqueous samples of methyl orange were exposed to low temperature air plasma and the degradation efficiency was determined by absorbance spectroscopy. The plasma was driven at a constant frequency of 35kHz with a duty cycle of 25%, 50%, 75% and 100%. Relative concentrations of dissolved nitrogen oxides, pH, conductivity and the time evolution of gas phase ozone were measured to identify key parameters responsible for the changes observed in degradation efficiency. The results indicate that pulse modulation significantly improved dye degradation efficiency, with a plasma pulsed at 25% duty showing a two-fold enhancement. Additionally, pulse modulation led to a reduction in the amount of nitrate contamination added to the solution by the plasma. The results clearly demonstrate that optimization of the electrical excitation of the plasma can enhance both degradation efficiency and the final water quality.

Ephrin-A3 and ephrin-A4 contribute to microglia-induced angiogenesis in brain endothelial cells

The association of microglia with brain vasculature during development and the reduced brain vascular complexity in microglia-deficient mice suggest the role of microglia in cerebrovascular angiogenesis. However, the underlying molecular mechanism remains unclear. Here, using an in vitro angiogenesis model, we found the culture supernatant of BV2 microglial cells significantly enhanced capillary-like tube formation and migration of brain microvascular endothelial cells (BMECs). The expression of angiogenic factors, ephrin-A3 and ephrin-A4, were specifically upregulated in BMECs exposed to BV2-derived culture supernatant. Knockdown of ephrin-A3 and ephrin-A4 in BMECs by siRNA significantly attenuated the enhanced angiogenesis and migration of BMECs induced by BV2 supernatant. Our further results indicated that the ability of BV2 supernatant to promote endothelial angiogenesis was caused by the soluble tumor necrosis factor α (TNF-α) released from BV2 microglial cells. Moreover, the upregulations of ephrin-A3 and ephrin-A4 in BMECs in response to BV2 supernatant were effectively abolished by neutralization antibody against TNF-α and TNF receptor 1, respectively. The present study provides evidence that microglia upregulates endothelial ephrin-A3 and ephrin-A4 to facilitate in vitro angiogenesis of brain endothelial cells, which is mediated by microglia-released TNF-α.

Identification of two ATR-dependent phosphorylation sites on coronavirus nucleocapsid protein with nonessential functions in viral replication and infectivity in cultured cells

Coronavirus encodes an extensively phosphorylated and highly basic nucleocapsid (N) protein. Previous studies have identified Ser190, Ser192, Thr378 and Ser379 as the phosphorylation sites for coronavirus infectious bronchitis virus (IBV) N protein. In this study, we show that phosphorylation at Thr378 and Ser379 sites is dependent on the ataxia-telangiectasia mutated (ATM) and Rad3-related (ATR), a kinase activated during IBV replication. Introduction of Ala substitutions at these two sites individually, in combination of the two and together with other two sites (Ser190 and Ser192) into an infectious IBV clone did not affect recovery of the recombinant viruses containing the mutations. A mutant virus (rIBV-Nm4) carrying the four Ala substitutions grew at a similar, if not better, growth rate as wild type virus. This study reveals a cellular kinase responsible for phosphorylation of a coronavirus N protein at two positions and the functional consequence of this modification on coronavirus replication.

•

We study the functional relevance of phosphorylation of IBV N on viral replication.

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We identify two ATR-dependent phosphorylation sites on IBV N protein.

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We analyze the functions of these sites on IBV replication and infectivity.

Metabolic changes of human dental pulp after rapid palatal expansion

OBJECTIVES

To investigate rapid palatal expansion (RPE)-induced metabolic changes in human dental pulp by measuring the expression and activity of aspartate aminotransferase (AST).

METHODS

mRNA and protein levels of AST in human dental pulp were measured by quantitative real-time polymerase chain reaction and Western blot, respectively. Furthermore, the activity of AST was measured by a full automatic biochemical analyzer.

RESULTS

AST mRNA and protein levels were found to be expressed in normal dental pulp. Moreover, the expression of AST was increased significantly after 14 days of RPE and then decreased at 1 month in retention. Three and 6 months after RPE, the AST expression level was gradually decreased to its baseline level. Similarly, AST activity was significantly elevated after 14 days of RPE, which was then down-regulated at 1 month in retention but was still kept at a higher level as compared with the control group. The enzymatic activity of AST was slowly decreased to its baseline level at 3 and 6 months in retention.

CONCLUSIONS

These results showed that significant reversible metabolic changes occurred in dental pulp during RPE, which revealed the high capacity of the pulp tissue for adaptation to this orthopedic method.

cPLA2α-mediated actin rearrangements downstream of the Akt signaling is required for Cronobacter sakazakii invasion into brain endothelial cells

Cronobacter sakazakii (C. sakazakii) is an opportunistic pathogen that causes sepsis and meningitis in neonate. The molecular mechanism involved in the pathogenesis of C. sakazakii meningitis remains unclear. In this study, we found that C. sakazakii invasion was significantly decreased in human brain microvascular endothelial cells (HBMEC) treated with cytosolic phospholipases A(2)α (cPLA(2)α) inhibitor. Increased phosphorylation of cPLA(2)α was observed in HBMEC infected with C. sakazakii, which was prevented by treatment with cPLA(2)α inhibitor. cPLA(2)α knockdown in HBMEC significantly attenuated C. sakazakii invasion into HBMEC. Immunofluorescence demonstrated that the rearrangements of actin filaments in HBMEC induced by C. sakazakii were effectively blocked by either treatment with cPLA(2)α inhibitor or transfection with cPLA(2)α siRNA. Interestingly, we found that C. sakazakii infection promoted the aggregation of phosphorylated cPLA(2)α, which was associated with depolymerized actin filaments in HBMEC. Furthermore, our data revealed that cPLA(2)α acts downstream of Akt signaling pathway in HBMEC stimulated with C. sakazakii. Taken together, our results illustrated that cPLA(2)α-mediated actin filament rearrangements downstream of Akt activation is required for C. sakazakii invasion into brain endothelial cells.

Imaging presentation highly manifested as tuberculosis in a case of spinal metastatic carcinoma

Usually the clinical manifestations between spinal tuberculosis (Pott's disease) and metastasis are not characteristic. Nevertheless, their respective imaging presentations are typical and specific, which makes it relatively easier to attain a correct diagnosis. Imaging features of Pott's disease, in general, include narrowing of intervertebral disk space, collapse of vertebral bodies with eventual progression to kyphotic deformity, destruction of the anterior parts of adjacent vertebrae, formation of a large paravertebral abscess, and calcifications or sequestra within the paravertebral abscess. Spinal tuberculosis is usually endemic, especially in Eastern countries. However, the trend of cancer incidence is also increasing in modern society, which makes it difficult to diagnose spinal osseous lesions. This article presents a case of a 45-year-old man with a 9-month history of low back pain. Both computed tomography and magnetic resonance imaging of the lumbar spine supported the initial diagnosis of spinal tuberculosis. However, pathological examination on the excised specimen resulted in the diagnosis of spinal metastatic adenocarcinoma. We suggest that a definitive diagnosis of spinal metastasis or tuberculosis should not be based on imaging alone. Instead, more attention should be paid to atypical imaging presentations. In addition, biopsy is usually necessary for final diagnosis.

Panax notoginseng saponins promote osteogenic differentiation of bone marrow stromal cells through the ERK and P38 MAPK signaling pathways

The Chinese medicinal herb, Panax notoginseng, has long been used to treat bone fractures and Panax notoginseng saponins (PNS) could promote bone formation. Here, we investigated whether PNS could promote osteogenesis of bone marrow stromal cells (BMSCs) through modulating the MAPK signaling pathways, which are implicated in BMSC osteogenesis. We found that PNS markedly increased the mineralization of BMSCs by alizarin red S assays and stimulate alkaline phosphatase activity of these cells. Additionally, PNS significantly increased the mRNA levels of alkaline phosphatase, core-binding factor a1, and bone sialoprotein while decreasing PPARγ2 mRNA levels. Furthermore, inhibitors of ERK, PD98059, and p38, SB203580 inhibited the osteogenesis-potentiating effects by PNS. PNS stimulated the activation of ERK and p38 as evidenced by increased phosphorylation of these proteins, which was inhibited by PD98059 and SB203580. Our findings indicate that PNS could promote BMSC osteogenesis by activating the ERK and p38 signaling pathways.

Artemin is oncogenic for human mammary carcinoma cells

We report that artemin, a member of the glial cell line-derived neurotrophic factor family of ligands, is oncogenic for human mammary carcinoma. Artemin is expressed in numerous human mammary carcinoma cell lines. Forced expression of artemin in mammary carcinoma cells results in increased anchorage-independent growth, increased colony formation in soft agar and in three-dimensional Matrigel, and also promotes a scattered cell phenotype with enhanced migration and invasion. Moreover, forced expression of artemin increases tumor size in xenograft models and leads to highly proliferative, poorly differentiated and invasive tumors. Expression data in Oncomine indicate that high artemin expression is significantly associated with residual disease after chemotherapy, metastasis, relapse and death. Artemin protein is detectable in 65% of mammary carcinoma and its expression correlates to decreased overall survival in the cohort of patients. Depletion of endogenous artemin with small interfering RNA, or antibody inhibition of artemin, decreases the oncogenicity and invasiveness of mammary carcinoma cells. Artemin is therefore oncogenic for human mammary carcinoma, and targeted therapeutic approaches to inhibit artemin function in mammary carcinoma warrant consideration.

Coronavirus envelope protein: a small membrane protein with multiple functions

Coronavirus envelope protein is a small membrane protein and minor component of the virus particles. It plays important roles in virion assembly and morphogenesis, alteration of the membrane permeability of host cells and virus-host cell interaction. Here we review recent progress in characterization of the biochemical properties, membrane topology and functions of the protein.

Transcriptional activation of p53 by Pitx1

Little is known about factors that stimulate transcription of the p53 tumor suppressor gene. Here, we report that the human pituitary homeobox 1 (hPitx1) transcription factor increases the expression of p53 at the mRNA and protein levels in human mammary carcinoma (MCF-7) cells. Increased p53 mRNA expression was due to activation of the p53 promoter by hPitx1. hPitx1 bound directly to the p53 promoter and functionally utilized two hPitx1 consensus elements. The predominant consensus element utilized by hPitx1 to stimulate p53 transcription was located within the first exon of the p53 gene. A hPitx1 mutant (hPitx1-R141P) acting as a dominant inhibitor repressed p53 transcription. Forced expression of hPitx1 resulted in cell-cycle arrest and p53-dependent apoptosis in p53-replete MCF-7 cells. Furthermore, hPitx1 stimulated the transcription of p53 target genes involved in cell-cycle arrest and apoptosis (p21 and PTGF-beta), again in a p53-dependent manner. Depletion of endogenous hPitx1 by small interfering RNA (siRNA) in MCF-7 cells resulted in decreased basal expression of p53 and consequently of p21 and placental transforming growth factor beta (PTGF-beta). Depletion of p53 by siRNA dramatically attenuated hPitx1-induced apoptosis in MCF-7 cells. Thus, p53 is a direct transcriptional target gene of hPitx1. This observation is concordant with the recent identification of hPitx1 as a tumor suppressor gene.

Translation initiation at an upstream CUG codon regulates the expression of Hibiscus chlorotic ringspot virus coat protein

Viruses depend heavily on host cells for replication and exploit the host translation machinery for its gene expression using various unorthodox translation mechanisms. According to the conventional scanning model, only the 5'-proximal gene in the viral RNA is accessible to the ribosomes whereas other genes are silent. In this study, we use a model plant RNA virus, Hibiscus chlorotic ringspot virus (HCRSV), to investigate various translation mechanisms involved in regulation of the expression of internal genes. The 3'-end 1.2kb region of HCRSV genomic and subgenomic RNAs were shown to encode four polypeptides of 38, 27, 25 and 22.5kDa. Mutagenesis studies revealed that a CUG codon ((2570)CUG) is the initiation codon for p27, the longest of the three co-C-terminal products (p27, p25 and p22.5), and translation of p25 and p22.5 was initiated at (2603)AUG and (2666)AUG, respectively. Translation initiation of the p27 expression at the (2570)CUG codon regulates the expression of p38, the viral coat protein through a leaky scanning mechanism and mutational analysis of an upstream open reading frame (ORF) demonstrated that initiation of the p27 expression at this CUG codon (instead of an AUG) may play a role in maintaining the ratio of p27 and p38. In addition, a previously identified internal ribosome entry site was shown to control the expression of p27 and p38 in the subgenomic RNA 2.

Biochemical and functional characterization of Epstein-Barr virus-encoded BARF1 protein: interaction with human hTid1 protein facilitates its maturation and secretion

EBV BARF1 gene encodes a secretory protein with transforming and mitogenic activities. In this report, the post-translational modification, folding, maturation and secretion of BARF1 are systematically studied by site-directed mutagenesis and overexpression of the protein in mammalian cells using the vaccinia/T7 system. The protein was shown to be post-translationally modified by N-linked glycosylation on the asparagine 95 residue. This modification was confirmed to be essential for the maturation and secretion of the protein. Analysis of the four cysteine residues by site-directed mutagenesis demonstrated that cysteine 146 and 201 were essential for proper folding and secretion of the protein. To search for human proteins involved in the maturation process of the protein, a yeast two-hybrid screening was carried out using the BARF1 sequence from amino acids 21-221 (BARF1Delta) as bait, leading to the identification of human hTid1 protein as a potential interacting protein. This interaction was subsequently confirmed by coimmunoprecipitation and dual immunofluorescent labeling of cells coexpressing BARF1 and hTid1, and the interaction domain in hTid1 was mapped to amino acids 149-320. Interestingly, coexpression of BARF1 with hTid1 demonstrated that hTid1 could promote secretion of BARF1, suggesting that hTid1 may act as a chaperone to facilitate the folding, processing and maturation of BARF1.

Selection of and recombination between minor variants lead to the adaptation of an avian coronavirus to primate cells

An interesting question posed by the current evidence that severe acute respiratory syndrome coronavirus may be originated from an animal coronavirus is how such an animal coronavirus breaks the host species barrier and becomes zoonotic. In this report, we study the chronological order of genotypic changes in the spike protein of avian coronavirus infectious bronchitis virus (IBV) during its adaptation to a primate cell line. Adaptation of the Beaudette strain of IBV from chicken embryo to Vero cells showed the accumulation of 49 amino acid mutations. Among them, 26 (53.06%) substitutions were located in the S protein. Sequencing analysis and comparison of the S gene demonstrated that the majority of the mutations were accumulated and fixed at passage 7 on Vero cells and minor variants were isolated in several passages. Evidence present suggests that the dominant Vero cell-adapted IBV strain may be derived from the chicken embryo passages by selection of and potential recombination between the minor variants. This may explain why adaptation is a rapid process and the dominant strain, once adapted to a new host cell, becomes relatively stable.