If neuropilin-2 and the growth factor VEGF-C don’t come together, lymphatic vessels don’t branch apart.

BackgroundThe recent emergence and spread of artemisinin resistance in the Greater Mekong Subregion poses a great threat to malaria control and elimination. A K13-propeller gene (K13), PF3D7_1343700, has been associated lately with artemisinin resistance both in vitro and in vivo. This study aimed to investigate the K13 polymorphisms in Plasmodium falciparum parasites from the China-Myanmar border area where artemisinin use has the longest history.MethodsA total of 180 archived P. falciparum isolates containing 191 parasite clones, mainly collected in 2007–2012 from the China-Myanmar area, were used to obtain the full-length K13 gene sequences.ResultsSeventeen point mutations were identified in 46.1% (88/191) parasite clones, of which seven were new. The F446I mutation predominated in 27.2% of the parasite clones. The C580Y mutation that is correlated with artemisinin resistance was detected at a low frequency of 1.6%. Collectively, 43.1% of the parasite clones contained point mutations in the kelch domain of the K13 gene. Moreover, there was a trend of increase in the frequency of parasites carrying kelch domain mutations through the years of sample collection. In addition, a microsatellite variation in the N-terminus of the K13 protein was found to have reached a high frequency (69.1%).ConclusionsThis study documented the presence of mutations in the K13 gene in parasite populations from the China-Myanmar border. Mutations present in the kelch domain have become prevalent (>40%). A predominant mutation F446I and a prevalent microsatellite variation in the N-terminus were identified, but their importance in artemisinin resistance remains to be elucidated.

Drug resistance has emerged as one of the greatest challenges facing malaria control. The recent emergence of resistance to artemisinin (ART) and its partner drugs in ART-based combination therapies (ACT) is threatening the efficacy of this front-line regimen for treating Plasmodium falciparum parasites. Thus, an understanding of the molecular mechanisms that underlie the resistance to ART and the partner drugs has become a high priority for resistance containment and malaria management. Using genome-wide association studies, we investigated the associations of genome-wide single nucleotide polymorphisms with in vitro sensitivities to 10 commonly used antimalarial drugs in 94 P. falciparum isolates from the China-Myanmar border area, a region with the longest history of ART usage. We identified several loci associated with various drugs, including those containing pfcrt and pfdhfr. Of particular interest is a locus on chromosome 10 containing the autophagy-related protein 18 (ATG18) associated with decreased sensitivities to dihydroartemisinin, artemether and piperaquine – an ACT partner drug in this area. ATG18 is a phosphatidylinositol-3-phosphate binding protein essential for autophagy and recently identified as a potential ART target. Further investigations on the ATG18 and genes at the chromosome 10 locus may provide an important lead for a connection between ART resistance and autophagy.

Objective The artificial liver support system (ALSS) is used frequently as a first‐line treatment for hepatitis B virus‐associated acute‐on‐chronic liver failure (HBV‐ACLF). This study aims to compare the therapeutic efficacy of double plasma molecular adsorption system (DPMAS) with sequential half‐dose plasma exchange (PE) (DPMAS+PE) and full‐dose PE in patients with HBV‐ACLF. Methods A total of 131 hospitalized patients who were diagnosed with HBV‐ACLF and underwent DPMAS+PE or PE were retrospectively analyzed. According to the treatment methods used, they were divided into PE group (n = 77) and DPMAS+PE group (n = 54). The main evaluation indexes included the change of liver function and the 28‐days liver transplant‐free survival rates after the different treatments. Results There were no significant differences on severity of illness between PE group and DPMAS+PE group (P > 0.05). The total bilirubin (TBIL) levels immediately after treatment, and at 24 and 72 hours after treatment were markedly decreased in DPMAS+PE group than that in PE group (52.3 ± 9.4% vs 42.3 ± 7.2%, P < 0.05; 24.2 ± 10.0% vs 13.5 ± 13.0%, P < 0.05; 24.8 ± 13.1% vs 14.9 ± 14.9%, P < 0.05; respectively). The 28‐days survival rates was 62.3% and 72.2% in PE and DPMAS+PE groups (P = 0.146). Furthermore, the 28‐days survival rates were significantly higher in DPMAS+PE group than that in PE group (57.4% vs 41.7%, P = 0.043) in the intermediate‐advanced stage patients. Conclusion Compared with PE alone, DPMAS+PE might more effectively improve temporary TBIL in ACLF patients, and improve the 28‐days survival rates in HBV‐ACLF patients with intermediate‐advanced stage. Therefore, DPMAS+PE may be an available ALSS treatment for HBV‐ACLF patients.

h Chloroquine-primaquine (CQ-PQ) continues to be the frontline therapy for radical cure of Plasmodium vivax malaria. Emergence of CQ-resistant (CQR) P. vivax parasites requires a shift to artemisinin combination therapies (ACTs), which imposes a significant financial, logistical, and safety burden. Monitoring the therapeutic efficacy of CQ is thus important. Here, we evaluated the therapeutic efficacy of CQ-PQ for P. vivax malaria in northeast Myanmar. We recruited 587 patients with P. vivax monoinfection attending local malaria clinics during 2012 to 2013. These patients received three daily doses of CQ at a total dose of 24 mg of base/kg of body weight and an 8-day PQ treatment (0.375 mg/kg/day) commencing at the same time as the first CQ dose. Of the 401 patients who finished the 28-day follow-up, the cumulative incidence of recurrent parasitemia was 5.20% (95% confidence interval [CI], 3.04% to 7.36%). Among 361 (61%) patients finishing a 42-day follow-up, the cumulative incidence of recurrent blood-stage infection reached 7.98% (95% CI, 5.20% to 10.76%). The cumulative risk of gametocyte carriage at days 28 and 42 was 2.21% (95% CI, 0.78% to 3.64%) and 3.93% (95% CI, 1.94% to 5.92%), respectively. Interestingly, for all 15 patients with recurrent gametocytemia, this was associated with concurrent asexual stages. Genotyping of recurrent parasites at the merozoite surface protein 3␣ gene locus from 12 patients with recurrent parasitemia within 28 days revealed that 10 of these were the same genotype as at day 0, suggesting recrudescence or relapse. Similar studies in 70 patients in the same area in 2007 showed no recurrent parasitemias within 28 days. The sensitivity to chloroquine of P. vivax in northeastern Myanmar may be deteriorating. Plasmodium vivax has the widest geographical distribution among the four human-infecting species, stretching from the Korean Peninsula to northern Argentina. An estimated 2.48 billion people lived at risk of P. vivax malaria in 2010, of which a large majority was in Central and Southeast Asia (1). Each year, P. vivax infects an estimated 130 to 391 million people (2, 3). Past eradication campaigns have witnessed the resilience of vivax malaria to control efforts. In areas where P. vivax and P. falciparum are coendemic, intensified control efforts have led to major changes in malaria epidemiology, and the problem of vivax malaria has become more prominent (4). With emerging global interests in malaria elimination (5), many nations in which vivax malaria is endemic will inevitably face greater challenges for the control and elimination of this parasite. For example, among the 34 malariaeliminating countries, 26 have malaria burdens mainly or solely due to P. vivax (4).The relative resilience of vivax malaria may be attributed to the formation of dormant hypnozoites in the livers of patients. These hypnozoites awaken in the weeks and months following a primary attack and cause new attacks, called relapses. Thus, treatment of P. vivax malaria requires drugs that target both the ...

BackgroundHIV-related stigma always is major obstacles to an effective HIV response worldwide. The effect of HIV-related stigma on HIV prevention and treatment is particularly serious in China. This study was to examine stigma attitude towards people living with HIV/AIDS (PLWHA) among general individuals in Heilongjiang Province, Northeast China and the factors associated with stigma attitude, including socio-demographic factors and HIV/AIDS Knowledge.MethodsA cross-sectional survey was carried out in Heilongjiang Province, China. A total of 4050 general individuals with age 15–69 years in four villages in rural areas and two communities in urban areas were drawn using stratified cluster sampling. Standardized questionnaire interviews were administered. Univariate and multivariate log-binomial regression were performed to assess factors affecting stigma attitude towards PLWHA.ResultsThe proportions of participants holding stigma attitude towards PLWHA were 49.6% among rural respondents and 37.0% among urban respondents (P < 0.001). Multivariate log binomial regression analysis among both rural participants (RR = 0.89, 95% CI: 0.87–0.91, P < 0.001) and urban participants (RR = 0.89, 95% CI: 0.87–0.91, P < 0.001) showed that greater knowledge of HIV transmission misconceptions was significantly associated with lower stigma attitude towards people living with HIV. And among urban participants, higher education level (high school vs. primary school or less: RR = 0.73, 95%CI: 0.62–0.87, P < 0.001; middle school vs. primary school or less: RR = 0.83, 95%CI: 0.71–0.97, P = 0.018) were also significantly associated with lower stigma attitude towards PLWHA.ConclusionsThe level of stigma attitude towards PLWHA is higher in rural areas than in urban areas in Heilongjiang. Meanwhile, individuals who better were aware of HIV/AIDS transmission misconceptions may hold lower stigma attitude toward PLWHA whether among rural or urban residents.

Levels of genetic diversity of the malaria parasites and multiclonal infections are correlated with transmission intensity. In order to monitor the effect of strengthened malaria control efforts in recent years at the China-Myanmar border area, we followed the temporal dynamics of genetic diversity of three polymorphic antigenic markers msp1, msp2, and glurp in the Plasmodium falciparum populations. Despite reduced malaria prevalence in the region, parasite populations exhibited high levels of genetic diversity. Genotyping 258 clinical samples collected in four years detected a total of 22 PCR size alleles. Multiclonal infections were detected in 45.7% of the patient samples, giving a minimum multiplicity of infection of 1.41. The majority of alleles experienced significant temporal fluctuations through the years. Haplotype diversity based on the three-locus genotypes ranged from the lowest in 2009 at 0.33 to the highest in 2010 at 0.80. Sequencing of msp1 fragments from 36 random samples of five allele size groups detected 13 different sequences, revealing an additional layer of genetic complexity. This study suggests that despite reduced prevalence of malaria infections in this region, the parasite population size and transmission intensity remained high enough to allow effective genetic recombination of the parasites and continued maintenance of genetic diversity.

eThe recent reports of resistance in Plasmodium falciparum to artemisinin derivatives and their partner drugs demand intensive studies toward understanding the molecular mechanisms of resistance. In this study, we examined the in vitro susceptibility of 63 P. falciparum field isolates collected from the China-Myanmar border area to chloroquine (CQ) and piperaquine (PPQ). Parasite isolates remained highly resistant to CQ, with the geometric mean 50% inhibitory concentration (IC 50 ) of 252.7 nM and a range of 51.9 to 1,052.0 nM. In comparison, these parasites had a geometric mean IC 50 of 28.4 nM for PPQ, with a fairly wide range of 5.3 to 132.0 nM, suggesting that certain parasite isolates displayed relatively high levels of resistance to PPQ. Interestingly, within the 4 years of study, the parasites exhibited a continuous decline in susceptibilities to both CQ and PPQ, and there was a significant correlation between responses to CQ and PPQ (Pearson correlation coefficient ‫؍‬ 0.79, P < 0.0001). Consistent with the CQ-resistant phenotype, all parasites carried the pfcrt K76T mutation, and most parasites had the CVIET type that is prevalent in Southeast Asia. In contrast, pfmdr1 mutations were relatively rare, and no gene amplification was detected. Only the pfmdr1 N1042D mutation was associated with resistance to CQ. For the pfmrp1 gene, four substitutions reached relatively high prevalence of >22%, and the I876V mutation was associated with reduced sensitivity to CQ. However, we could not establish a link between PPQ responses and the polymorphisms in the three genes associated with quinoline drug resistance.