A dual-antigen malaria vaccine targeting Pb22 and Pbg37 was able to induce robust transmission-blocking activity.

BACKGROUND: Despite years of effort to develop an effective vaccine against malaria infection, a vaccine that provides individuals with sufficient protection against malaria illness and death in endemic areas is not yet available. The development of transmission-blocking vaccines (TBVs) is a promising strategy for malaria control. A dual-antigen malaria vaccine targeting both pre- and post-fertilization antigens could effectively improve the transmission-blocking activity of vaccines against the sexual stages of the parasite. METHODS: A chimeric recombinant protein Pb22-Pbg37 (Plasmodium berghei 22-P. berghei G37) composed of 19-218 amino acids (aa) of Pb22 and the N-terminal 26-88 aa of Pbg37 was designed and expressed in the Escherichia coli expression system. The antibody titers of the fusion (Pb22-Pbg37) and mixed (Pb22+Pbg37) antigens, as well as those of Pb22 and Pbg37 single antigens were evaluated by enzyme-linked immunosorbent assay. Immunofluorescence and western blot assays were performed to test the reactivity of the antisera with the native proteins in the parasite. The induction of transmission-blocking activity (TBA) by Pb22-Pbg37 and Pb22+Pbg37 were evaluated by in vitro gametocyte activation, gamete and exflagellation center formation, ookinete conversion, and in the direct mosquito feeding assay. RESULTS: The Pb22-Pbg37 fusion protein was successfully expressed in vitro. Co-administration of Pb22 and Pbg37 as a fusion or mixed protein elicited comparable antibody responses in mice and resulted in responses to both antigens. Most importantly, both the mixed and fusion antigens induced antibodies with significantly higher levels of TBA than did each of the individual antigens when administered alone. In addition, the efficacy of vaccination with the Pb22-Pbg37 fusion protein was equivalent to that of vaccination with the mixed single antigens. CONCLUSIONS: Dual-antigen vaccines, which expand/lengthen the period during which the transmission-blocking antibodies can act during sexual-stage development, can provide a promising higher transmission-reducing activity compared to single antigens.

Symptom aggravation after withdrawal of metal chelating agent therapy in patients with Wilson's disease.

OBJECTIVE: To study the aggravation of clinical symptoms after discontinuation of metal chelating agent therapy in Wilson's disease (WD) patients, analyze the causes of aggravation, and observe the prognosis. METHODS: 40 WD patients (cerebral type 30 cases and hepatic type 10 cases) who stopped using metal chelating agent were selected, 40 WD patients with normal therapy, and 10 normal control cases were selected. All patients underwent neurological symptom evaluation using modified Young scale, Child-Pugh liver function grading, metal metabolism, and disease typing. Magnetic sensitivity imaging (SWI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy imaging (MRS) were performed. According to the imaging results, WD patients were divided into metal deposition stage, fiber damage stage, and neuron necrosis stage. All patients were treated with metal chelating agent for 6 months. RESULTS: The score of modified Young scale in drug withdrawal group was lower than that in normal treatment group before drug withdrawal (p = .032). The score of modified Young scale was higher after drug withdrawal than before (p = .011). The number of Child-Pugh B-grade patients after drug withdrawal was more than that before drug withdrawal and in normal treatment group. The proportion of patients in the stage of neuronal necrosis after drug withdrawal (25%) was higher than that before drug withdrawal (10%) (p = .025). After drug withdrawal, urine copper was significantly higher than that before drug withdrawal and in the normal treatment group (p = .032, .039). After the withdrawal group resumed metal chelating agent treatment, 34.2% of neurological symptoms worsened. CONCLUSIONS: WD patients showed neurological symptoms aggravation and increased liver injury after metal chelating agent withdrawal. Increased metal deposition and new nerve injury occurred in the brain. After re-treatment, the aggravated neurological symptoms of WD patients are difficult to reverse.

Plasmodium falciparum GAP40 Plays an Essential Role in Merozoite Invasion and Gametocytogenesis.

Cyclic invasion of red blood cells (RBCs) by Plasmodium merozoites is associated with the symptoms and pathology of malaria. Merozoite invasion is powered actively and rapidly by a parasite actomyosin motor called the glideosome. The ability of the glideosome to generate force to support merozoite entry into the host RBCs is thought to rely on its stable anchoring within the inner membrane complex (IMC) through membrane-resident proteins, such as GAP50 and GAP40. Using a conditional knockdown (KD) approach, we determined that PfGAP40 was required for asexual blood-stage replication. PfGAP40 is not needed for merozoite egress from host RBCs or for the attachment of merozoites to new RBCs. PfGAP40 coprecipitates with PfGAP45 and PfGAP50. During merozoite invasion, PfGAP40 is associated strongly with stabilizing the expression levels of PfGAP45 and PfGAP50 in the schizont stage. Although PfGAP40 KD did not influence IMC integrity, it impaired the maturation of gametocytes. In addition, PfGAP40 is phosphorylated, and mutations that block phosphorylation of PfGAP40 at the C-terminal serine residues S370, S372, S376, S405, S409, S420, and S445 reduced merozoite invasion efficiency. Overall, our findings implicate PfGAP40 as an important regulator for the gliding activity of merozoites and suggest that phosphorylation is required for PfGAP40 function. IMPORTANCE Red blood cell invasion is central to the pathogenesis of the malaria parasite, and the parasite proteins involved in this process are potential therapeutic targets. Gliding motility powers merozoite invasion and is driven by a unique molecular motor termed the glideosome. The glideosome is stably anchored to the parasite inner membrane complex (IMC) through membrane-resident proteins. In the present study, we demonstrate the importance of an IMC-resident glideosome component, PfGAP40, that plays a critical role in stabilizing the expression levels of glideosome components in the schizont stage. We determined that phosphorylation of PfGAP40 at C-terminal residues is required for efficient merozoite invasion.

BEZ235 reduction of cisplatin resistance on wild-type EGFR non-small cell lung cancer cells.

Cisplatin, as a first-line chemotherapy drug for advanced wild-type epidermal growth factor receptor (wtEGFR) non-small cell lung cancer (NSCLC), often loses effectiveness because of acquired drug resistance. We found that ataxia-telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) of DNA repair kinases and signal transduction molecules, protein kinase B (AKT)/target mammalian target of rapamycin (mTOR), were significantly phosphorylated in cisplatin-resistant wtEGFR NSCLC cell lines (H358R and A549R) than in their parental cells. Also, BEZ235 (dual phosphatidylinositol-3-kinase (PI3K)/mTOR inhibitor) significantly decreased the phosphorylation levels of these kinases/proteins, as detected by Western blot analysis. In H358R and A549R cells, the results of indirect immunofluorescence, single-cell gel electrophoresis, flow cytometry, methylthiazolyldiphenyl-tetrazolium bromide, clone formation assay, and scratch healing experiment showed that BEZ235 enhanced cisplatin-induced DNA damage and cell apoptosis, and effectively inhibited cellular proliferation/migration when combined with cisplatin. The data indicated that the abnormal activation of ATM/ATR/DNA-PKcs kinases and AKT/mTOR pathway might induce wtEGFR NSCLC cell resistance to cisplatin. The effects of the combination of BEZ235 and cisplatin suggested that BEZ235 should be considered as a combination therapy for patients with cisplatin-resistant wtEGFR NSCLC.

Chronic Microcystin-LR Exposure Induces Abnormal Lipid Metabolism via Endoplasmic Reticulum Stress in Male Zebrafish.

In order to explore effects of low levels of continuous microcystin-LR (MC-LR) (a cyanotoxin) exposure on hepatic lipid metabolism on the basis of the endoplasmic reticulum stress (ERS) pathway, we exposed adult male zebrafish to MC-LR (0, 1, 5, and 25 µg/L) for 60 days, and hepatic histopathology as well as lipid metabolic parameters were determined with mRNA levels of ERS signal molecules and downstream factors, along with genes associated with lipid metabolism in zebrafish liver. The results revealed that prolonged exposure to MC-LR remarkably altered the levels of hepatic total cholesterol and triglyceride and led to hepatic steatosis, which was also confirmed by hepatic cytoplasmic vacuolization in Hematoxylin/eosin (H&E) stain and lipid droplet accumulation in Oil Red O stain. The severity of hepatic damage and lipidation was increased in a dose-related manner. MC-LR exposure significantly upregulated transcriptional levels of ERS markers including hspa5, mapk8, and chop, indicating the occurrence of ERS in the liver of zebrafish. Concurrently, MC-LR significantly improved mRNA expression of unfolded protein response (UPR) pathway-related genes including atf6, eif2ak3, ern1, and xbp1s, suggesting that all of the three UPR branches were activated by MC-LR. MC-LR also induced significant upregulation of downstream lipid metabolism-related factors and genes including srebf1, srebf2, fatty acid synthase (fasn), acetyl-CoA carboxylase (acaca), stearoyl-CoA desaturase (scd), HMG CoA reductase (hmgcra), and HMG CoA synthase (hmgcs1), and downregulation of genes associated with lipolysis such as triglyceride hydrolase gene (atgl), hormone-sensitive enzyme gene (hsla), and carnitine palmitoyltransferase gene (cpt1aa). Our present results indicated that the cause of hepatic lipid accumulation by MC-LR was mainly by upregulating lipogenic and cholesterol genes but downregulating the expression of lipolytic genes through the induction of srebf1 and srebf2, which were involved in the activation of ERS signal pathways.

Co2+ anchored on surface-functionalized PET non-woven fabric and used as high efficiency monoatom-like catalyst for activating Oxone in water.

Fenton-like processes have emerged as most promising techniques for generating reactive oxygen-containing radicals to deal with increasing levels of environmental pollution. Developing novel catalysts with simple manufacturing requirements, excellent activity levels, and stability remains a long-term goal in terms of practical application. So herein, a new polyethylene terephthalate (PET) non-woven fabric based composite catalyst has been fabricated, using radiation-induced graft polymerization of a functionalized group to chelate Co2+ ions as heterogeneous catalysts in peroxymonosulfate (Oxone) activation. Several impact factors, including catalyst dosage, Oxone concentration, reaction temperature, pH value, Co2+ precipitation ratio (of Co@PET at different pH values), and highly concentrated NaCl have been investigated here. Notably, Co@PET has shown the lowest activation energy of any reported catalyst, for degrading RhB by activating Oxone. Interestingly, as experimental RhB and Oxone solutions were passed through single Co@PET sheets, the RhB was decomposed into a colorless solution in the penetration process. Based on radical trapping and quenching experiments, a channel was determined to dominate RhB degradation, and furthermore, Co@PET could be re-used for RhB degradation by activating Oxone. These results showed that Co@PET effectively provided improved Fenton-like catalytic performance and stability, and was suitable for practical applications.

Flexible and Highly Sensitive Humidity Sensor Based on Sandwich-Like Ag/Fe3O4 Nanowires Composite for Multiple Dynamic Monitoring.

Functional textiles with unique functions, including free cutting, embroidery and changeable shape, will be attractive for smart wear of human beings. Herein, we fabricated a sandwich-like humidity sensor made from silver coated one-dimensional magnetite nanowire (Fe3O4 NW) arrays which were in situ grown on the surface of modified polypropylene nonwoven fabric via simultaneous radiation induced graft polymerization and co-precipitation. The humidity sensor exhibits an obvious response to the relative humidity (RH) ranging from RH 11% to RH 95% and its response value reaches a maximum of 6600% (ΔI/I0) at 95% relative humidity (RH). The humidity sensor can be tailored into various shapes and embroidered on its surface without affecting its functionalities. More interesting, the intensity of its response is proportional to the size of the material. These features permit the sensor to be integrated into commercial textiles or a gas mask to accurately monitor a variety of important human activities including respiration, blowing, speaking and perspiration. Moreover, it also can distinguish different human physical conditions by recognizing respiration response patterns. The sandwich-like sensor can be readily integrated with textiles to fabricate promising smart electronics for human healthcare.

Copper-induced reduction in myocardial fibrosis is associated with increased matrix metalloproteins in a rat model of cardiac hypertrophy.

Trientine (TETA), a copper (Cu) chelator, is capable of replenishing Cu in the heart, and Cu repletion reduces cardiac fibrosis in a rodent model of cardiac hypertrophy. This study was undertaken to explore possible mechanisms by which Cu repletion diminishes cardiac fibrosis. Adult male Sprague-Dawley rats were subjected to ascending aortic constriction to induce cardiac hypertrophy. Four months after the operation, cardiac hypertrophy along with fibrosis was fully developed. TETA treatment was then followed at a dose of 21.9 mg kg-1, twice a day, administered orally for six weeks. At the end of the treatment, the hearts were harvested and all of the tissue samples were subjected to qRT-PCR, western blot, Sirius red staining, hydroxyproline assay, and immunostaining analyses. TETA treatment significantly increased the content of Cu in the hypertrophied myocardium, decreased type III collagen deposition and reduced cardiac fibrosis. On the other hand, this treatment did not alter the increase in fibroblasts induced by pressure overload, but significantly increased matrix metalloproteinase-2 (MMP-2), which is the enzyme mainly responsible for degradation of collagens in the heart. In addition, the mRNA and protein levels of tissue inhibitors of matrix metalloproteinase-1 and -2 (TIMP-1 and TIMP-2) were both remarkably increased in the hypertrophic myocardium, and normalized after TETA treatment. The data thus demonstrated that the reduction in cardiac fibrosis by TETA-induced Cu repletion is associated at least in part with an enhanced MMP-2 activity, leading to collagen degradation.

The Association Between Myocardial Fibrosis and Depressed Capillary Density in Rat Model of Left Ventricular Hypertrophy.

Myocardial fibrogenesis is initiated once the coordination between oxygen supply and demand is disrupted in pressure overload-induced cardiac hypertrophy. Clinical observations showed that myocardial fibrosis did not evenly occur in the hypertrophic myocardium. The present study was undertaken to specifically address differential vulnerabilities to fibrogenesis of different regions in the myocardium subjected to pressure overload-induced hypertrophy. SD rats were divided into two groups, sham-operated control and ascending artery constriction-induced cardiac hypotrophy. Thirty-four weeks after surgery, rats were sacrificed and hearts were harvested. Myocardial tissues were processed and sequentially sectioned for detection of collagen deposition, myocyte hypertrophy and vascular density analysis. Redundant collagen stained with Sirius red and anti-collagen I antibody was found in the extracellular matrix, but high volume of collagen fraction was largely localized more in posterior and lateral walls than in anterior wall and interventricular septum, which is in accordance with the accumulation of fibroblasts. In association with the differential regional collagen accumulation, the cardiomyocytes were more hypertrophic in the posterior and lateral wall than the other left ventricle. However, the capillary density in the lateral and posterior walls was significantly decreased. The results indicated that the posterior and lateral walls were more vulnerable to fibrogenesis post-pressure overload-induced cardiac hypertrophy, which was associated with the depressed angiogenesis in these two regions.

Asymmetrical in-fiber Mach-Zehnder interferometer for curvature measurement.

We demonstrated a compact and highly-sensitive curvature sensor based on a Mach-Zehnder interferometer created in a photonic crystal fiber. Such a Mach-Zehnder interferometer consisted of a peanut-like section and an abrupt taper achieved by use of an optimized electrical arc discharge technique, where only one dominating cladding mode was excited and interfered with the fundamental mode. The unique structure exhibited a high curvature sensitivity of 50.5 nm/m-1 within a range from 0 to 2.8 m-1, which made it suitable for high-sensitivity curvature sensing in harsh environments. Moreover, it also exhibited a temperature sensitivity of 11.7 pm/°C.

Disclosure of same-sex behavior by young Chinese migrant men: context and correlates.

The purpose of the study is to explore the disclosure of same-sex behavior by men who have sex with men (MSM) to different groups of people (i.e. family, friends, coworkers, and doctors) and the associated sociodemographic, behavioral, and psychosocial factors. A self-administered survey was conducted among 307 migrant MSM, aged 18-30, in Beijing in 2009. Most MSM disclosed their same-sex behavior to friends (69%), followed by family (25%), coworkers (25%), and doctors (24%). Factors associated with disclosure to friends included higher levels of perceived stigma, social capital and acculturation in Beijing, and suspecting partner to have a sexually transmitted disease (STD). Factors associated with disclosure to family included lower levels of internalized stigma, higher levels of acculturation in Beijing, and both risk and protective behavioral factors. MSM who disclosed to coworkers reported having worked in more cities, living with coworkers, and lower levels of social capital in Beijing. Disclosure to doctors was related to STD infection, sex partner, and sociodemographic factors. Results indicated that selective disclosure by MSM was situational and context-based. Future HIV/STD intervention needs to take into account factors relevant to their selective disclosure to different audiences.

HIV-testing behavior among young migrant men who have sex with men (MSM) in Beijing, China.

Previous studies suggested a rapid increase of HIV prevalence among men who have sex with men (MSM) in China in recent years, from 0.4% in 2004 to 5.8% in 2006. However, some MSM had never been tested for HIV. In order to expand the accessibility to HIV testing, understanding HIV-testing behavior and barriers among MSM is important. Using data collected from 307 young migrant MSM (aged 18-29 years) in 2009 in Beijing, we aimed to identify psychological and structural barriers to HIV testing. MSM were recruited through peer outreach, informal social networks, Internet outreach, and venue-based outreach. Participants completed a confidential self-administered questionnaire. Results show that about 72% of MSM ever had an HIV test. Logistic regression analysis indicated that the HIV-testing behavior was associated with sexual risk behaviors (e.g., multiple sexual partners and inconsistent condom use for anal sex) and history of sexually transmitted diseases. Eighty four MSM (28%) who never had an HIV test reported that the psychological barriers mainly were perceived low risk of HIV infection and fears of being stigmatized. The structural barriers reported inconvenience of doing test and lack of confidentiality. Future HIV prevention programs should be strengthened among MSM to increase their awareness of HIV risk. Efforts are needed to increase access to quality and confidential HIV testing among MSM and reduce stigma against MSM.