Artemisinin-naphthoquine plus lower-dose primaquine to treat and prevent recurrence of Plasmodium vivax malaria: an open-label randomized and non-inferiority trial

BACKGROUND

Plasmodium vivax malaria, with the widest geographic distribution, can cause severe disease and death. Primaquine is the main licensed antimalarial drug that can kill hypnozoites. The dose-dependent acute haemolysis in individuals with glucose-6-phospate dehydrogenase (G6PD) deficiency is the main safety concern when using primaquine. The recommended treatment regimen for P. vivax malaria is chloroquine plus primaquine for 14 days (CQPQ14) in Myanmar. The study aimed to evaluate the therapeutic efficacy, safety and adherence for the regimen of artemisinin-naphthoquine plus primaquine for 3 days (ANPQ3) in patients with P. vivax infections compared to those with CQPQ14.

METHODS

The patients in the ANPQ3 group were given fixed-dose artemisinin-naphthoquine (a total 24.5 mg/kg bodyweight) plus a lower total primaquine dose (0.9 mg/kg bodyweight) for 3 days. The patients in the CQPQ14 group were given a total chloroquine dose of 30 mg/kg body weight for 3 days plus a total primaquine dose of 4.2 mg/kg bodyweight for 14 days. All patients were followed up for 365 days.

RESULTS

A total of 288 patients completed follow-up, 172 in the ANPQ3 group and 116 in the CQPQ14 group. The first recurrence patients were detected by day 58 in both groups. By day 182, 16 recurrences had been recorded: 12 (7.0%) patients in the ANPQ3 group and 4 (3.4%) in the CQPQ14 group. The difference in recurrence-free patients was 3.5 (-8.6 to 1.5) percentage points between ANPQ3 and CQPQ14 group (P = 0.2946). By day 365, the percentage of recurrence-free patients was not significant between the two groups (P = 0.2257). Mean fever and parasite clearance time of ANPQ3 group were shorter than those in CQPQ14 group (P ≤ 0.001). No severe adverse effect was observed in ANPQ3 group, but five (3.9%) patients had acute haemolysis in CQPQ14 group (P = 0.013). Medication percentage of ANPQ3 group was significantly higher than that of CQPQ14 group (P < 0.0001).

CONCLUSIONS

Both ANPQ3 and CQPQ14 promised clinical cure efficacy, and the radical cure efficacy was similar between the ANPQ3 and CQPQ14 group. ANPQ3 clears fever and parasites faster than CQPQ14. ANPQ3 is safer and shows better patient adherence to the regimen for treatment of P. vivax malaria along the China-Myanmar border.

TRIAL REGISTRATION

ChiCTR-INR-17012523. Registered 31 August 2017, https://www.chictr.org.cn/showproj.html?proj=21352.

Treatment-seeking behaviours of malaria patients versus non-malaria febrile patients along China-Myanmar border

BACKGROUND

Appropriate malaria treatment-seeking behaviour (TSB) is critical for timely detecting malaria, prompt treatment, and prevention of onward transmission of the disease in a community. This study aimed to compare treatment-seeking behaviours between malaria patients and non-malaria febrile patients, and to analyse the factors associated with appropriate TSB along the China-Myanmar border.

METHODS

A cross-sectional study was carried out to investigate the appropriate TSB of microscopy-confirmed malaria patients versus non-malaria febrile (NMF) patients. An unconditional logistic regression analysis (LRA) was used to identify factors associated with appropriate TSB.

RESULTS

Among 223 malaria patients and 446 NMF patients, 129 (57.8%) of the malaria patients versus 163 (36.5%) of the NMF patients firstly sought treatment in health facilities without laboratory testing for malaria (P < 0.0001). A total of 85(38.1%) of the malaria patients versus 278 (62.3%) of the NMF patients had appropriate TSB, namely, seeking treatment in health facilities with laboratory testing for malaria within 48 h (P < 0.0001). Multivariate LRA identified that the malaria patients with Chinese nationality had less appropriate TSB compared to those with other nationalities (adjusted odds ratio [AOR]: 0.21, 95% confidence interval CI 0.07-0.68, P = 0.0097), and malaria patients residing in urban areas had more appropriate TSB compared to those living in rural areas (AOR: 2.16, 95%CI 1.06-4.39, P = 0.0337).

CONCLUSIONS

TSB was not appropriate in malaria patients. Chinese citizenship and rural residence were two independent factors associated with inappropriate malaria TSB. It is urgently necessary to improve appropriate malaria TSB through effective campaigns of information, education, and communication for malaria control in Myanmar and preventing reestablishment of malaria transmission in Yunnan, China.

Molecular dynamics exploration of helium bubble nucleation and growth mechanisms in Fe70Ni11Cr19 austenitic stainless steel

The growth of helium bubbles impacts structural integrity of materials in nuclear applications. Understanding helium bubble nucleation and growth mechanisms is critical for improved material applications and aging predictions. Systematic molecular dynamics simulations have been performed to study helium bubble nucleation and growth mechanisms in Fe70Ni11Cr19 stainless steels. First, helium cluster diffusivities are calculated at a variety of helium cluster sizes and temperatures for systems with and without dislocations. Second, the process of diffusion of helium atoms to join existing helium bubbles is not deterministic and is hence studied using ensemble simulations for systems with and without vacancies, interstitials, and dislocations. We find that bubble nucleation depends on diffusion of not only single helium atoms, but also small helium clusters. Defects such as vacancies and dislocations can significantly impact the diffusion kinetics due to the trapping effects. Vacancies always increase the time for helium atoms to join existing bubbles due to the short-range trapping effect. This promotes bubble nucleation as opposed to bubble growth. Interestingly, dislocations can create a long-range trapping effect that reduces the time for helium atoms to join existing bubbles. This can promote bubble growth within a certain region near dislocations.

An interplay between a hydrogen atmosphere and dislocation characteristics in BCC Fe from time-averaged molecular dynamics

The interplay between hydrogen and dislocations (e.g., core and elastic energies, and dislocation-dislocation interactions) has implications on hydrogen embrittlement but is poorly understood. Continuum models of hydrogen enhanced local plasticity have not considered the effect of hydrogen on dislocation core energies. Energy minimization atomistic simulations can only resolve dislocation core energies in hydrogen-free systems because hydrogen motion is omitted so hydrogen atmosphere formation can't occur. Additionally, previous studies focused more on face-centered-cubic than body-centered-cubic metals. Discrete dislocation dynamics studies of hydrogen-dislocation interactions assume isotropic elasticity, but the validity of this assumption isn't understood. We perform time-averaged molecular dynamics simulations to study the effect of hydrogen on dislocation energies in body-centered-cubic iron for several dislocation character angles. We see atmosphere formation and highly converged dislocation energies. We find that hydrogen reduces dislocation core energies but can increase or decrease elastic energies of isolated dislocations and dislocation-dislocation interaction energies depending on character angle. We also find that isotropic elasticity can be well fitted to dislocation energies obtained from simulations if the isotropic elastic constants are not constrained to their anisotropic counterparts. These results are relevant to ongoing efforts in understanding hydrogen embrittlement and provide a foundation for future work in this field.

Cardiovascular disease-linked plasma proteins are mainly associated with lung volume

Background

Impaired lung function is common and associated with increased risk of cardiovascular disease in epidemiological studies. Increased levels of several inflammatory and cardiovascular disease-related plasma proteins have been associated with impaired lung function. The aim was to study the association between plasma proteomics and forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio.

Methods

We used a discovery and replication approach in two community-based cohorts, EpiHealth and the Malmö Offspring Study (total n=2874), to cross-sectionally study 242 cardiovascular disease- and metabolism-linked proteins in relation to FEV1, FVC (both %predicted) and FEV1/FVC ratio. A false discovery rate of 5% was used as the significance threshold in the discovery cohort.

Results

Plasma fatty acid-binding protein 4, interleukin-1 receptor antagonist, interleukin-6 and leptin were negatively associated with FEV1and paraoxonase 3 was positively associated therewith. Fatty acid-binding protein 4, fibroblast growth factor 21, interleukin-1 receptor antagonist, interleukin-6 and leptin were negatively associated with FVC and agouti-related protein, insulin-like growth factor-binding protein 2, paraoxonase 3 and receptor for advanced glycation end products were positively associated therewith. No proteins were associated with FEV1/FVC ratio. A sensitivity analysis in EpiHealth revealed only minor changes after excluding individuals with known cardiovascular disease, diabetes, or obesity.

Conclusions

Five proteins were associated with both FEV1and FVC. Four proteins associated with only FVC and none with FEV1/FVC ratio, suggesting associations mainly through lung volume, not airway obstruction. However, additional studies are needed to investigate underlying mechanisms for these findings.

Risk factors associated with malaria infection along China–Myanmar border: a case–control study

Background

The World Health Organization (WHO) has certificated China malaria free, but imported malaria is a continuous challenge in preventing reintroduction of malaria in the border area of China. Understanding risk factors of malaria along China–Myanmar border is benefit for preventing reintroduction of malaria in China and achieving the WHO’s malaria elimination goal in the Greater Mekong Subregion (GMS).

Methods

This is a case–control study with one malaria case matched to two controls, in which cases were microscopy-confirmed malaria patients and controls were feverish people with microscopy-excluded malaria. A matched logistic regression analysis (LRA) was used to identify risk factors associated with malaria infection.

Results

From May 2016 through October 2017, the study recruited 223 malaria cases (152 in China and 71 in Myanmar) and 446 controls (304 in China and 142 in Myanmar). All the 152 cases recruited in China were imported malaria. Independent factors associated with malaria infection were overnight out of home in one month prior to attendance of health facilities (adjusted odd ratio [AOR] 13.37, 95% confidence interval [CI]: 6.32–28.28, P < 0.0001), staying overnight in rural lowland and foothill (AOR 2.73, 95% CI: 1.45–5.14, P = 0.0019), staying overnight at altitude < 500 m (AOR 5.66, 95% CI: 3.01–10.71, P < 0.0001) and streamlets ≤ 100 m (AOR9.98, 95% CI: 4.96–20.09, P < 0.0001) in the border areas of Myanmar; and people lacking of knowledge of malaria transmission (AOR 2.17, 95% CI: 1.42–3.32, P = 0.0004).

Conclusions

Malaria transmission is highly focalized in lowland and foothill in the border areas of Myanmar. The risk factors associated with malaria infection are overnight staying out of home, at low altitude areas, proximity to streamlets and lack of knowledge of malaria transmission. To prevent reintroduction of malaria transmission in China and achieve the WHO goal of malaria elimination in the GMS, cross-border collaboration is continuously necessary, and health education is sorely needed for people in China to maintain their malaria knowledge and vigilance, and in Myanmar to improve their ability of personal protection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04312-5.

Correction: Character angle effects on dissociated dislocation core energy in aluminum

Correction for 'Character angle effects on dissociated dislocation core energy in aluminum' by X. W. Zhou et al., Phys. Chem. Chem. Phys., 2021, 23, 3290-3299, DOI: https://doi.org/10.1039/D0CP05333C.

Character angle effects on dissociated dislocation core energy in aluminum

Dislocation core energy is an important property in materials mechanics but can only be obtained from atomistic simulations. Periodic boundary conditions are ideally suited for atomistic calculations of dislocation energies but have faced two major challenges. First, viable methods to extract core energies from atomistic data of total energies have been developed only for non-dissociated dislocations whereas realistic dislocations are often dissociated into partials. Second, core energy is a function of dislocation character angle. This functional dependence can only be revealed through calculations at a variety of character angles. This requires both additional computational resources and a robust method to implement arbitrary character angles. Here a new procedure has been developed to overcome both challenges. By applying this approach, we have calculated 22 core energies of dissociated dislocations in aluminium over the entire character angle range between 0° and 90°. In addition to the discrete core energy data for dissociated dislocations, we found that core energy can be approximated by a continuous function of character angle. Specifically, our dissociated dislocation core energies have been well fitted to a polynomial Sinoidal function of character angle. We have also discovered that there exists a critical system dimension below which dislocation core energies cannot be calculated due to dislocation transformation.

Thermodynamic analysis of dissociation of periodic dislocation dipoles in isotropic crystals

In the past, experimentally observed dislocations were often interpreted using an isolated dislocation assumption because the effect of background dislocation density was difficult to evaluate. Contrarily, dislocations caused by atomistic simulations under periodic boundary conditions can be better interpreted because linear elastic theory has been developed to address the effect of periodic dislocation array in the literature. However, this elastic theory has been developed only for perfect dislocations, but not for dissociated dislocations. The periodic boundary conditions may significantly change the dissociation energy of dislocations and stacking fault width, which in turn, change the deformation phenomena observed in simulations. To enable materials scientists to understand the dislocation behavior under the periodic boundary conditions, we use isotropic elastic theory to analyze the thermodynamics of dissociated periodic dislocations with an arbitrary dislocation character angle. Analytical expressions for force, stacking fault width, and energies are presented in the study. Results obtained from the periodic dislocation array were compared with those obtained from isolated dislocations to shed light on the interpretation of experimentally observed and simulated dislocations.

New elastic theory enables dissociation of periodic dislocations to be predicted.

Research Progress on the Molecular Mechanisms of Toxicology of Ethanol-Aconitine Induced Arrhythmia

Abstract

Aconitum is one of the most widely used Chinese herbal medicines, and aconitine is the major toxic component in it. Aconitine can induce a variety of arrhythmias, resulting in death. Acute ethanol consumption causes arrhythmia as well. Poisoning cases caused by aconitum medicinal liquor are frequently encountered in the practice of forensic medicine. The molecular mechanisms of myocardial toxicity of these two drugs have much in common, and both of them affect the sodium channel, calcium channel and potassium channel of myocardial cell membrane and so on. This paper analyzes and discusses the possible co-effects of ethanol-aconitine on cardiomyocyte channel proteins, by reviewing researches on the mechanism of cardiotoxicity of ethanol and aconitine in recent years, in order to provide ideas and references for the research on the molecular mechanism of arrhythmia caused by combined poisoning.

[The curative effect of manual reduction combined with vestibular rehabilitation exercise in the treatment of benign paroxysmal positional vertigo]

Objective:To investigate the effect of vestibular rehabilitation exercise combined with manual reduction in the treatment of benign paroxysmal positional vertigo（BPPV）. Method:A total of 186 patients with benign paroxysmal positional vertigo were selected and randomly divided into experimental group and control group . The control group was treated with manual reduction, while the experimental group was treated with manual reduction combined with vestibular rehabilitation exercises. Patients with posterior semicircular canal BPPV carried out Brandt-Daroff exercises, while patients with horizontal semicircular canal BPPV carried out Cawthorne-Cooksey exercises and position restriction. To analyze the clinical curative effect, DHI score, residual dizziness and recurrence of the two groups. Result:There was no significant difference in total efficiency rate and DHI score between the two groups at the first diagnosis（P>0.05）. After 1 week, 2 weeks and 1 month of follow-up, the total efficiency rate of the experimental group were 90.3%, 91.4% and 93.5% respectively, which were significantly higher than those of the control group（P<0.05）. Synchronously, the scores of DHI in experimental group were respectively 14.33±5.71, 12.25±4.98 and 9.45±3.70, which were significantly lower than the control group（P<0.05）. For the experimental group, in the first diagnosis, 1 week, 2 weeks and 1 month after follow-up, residual dizziness patients were 29 cases, 13 cases, 8 cases and 0 cases. The mean duration of residual dizziness was （5.86±4.71） days, which was significantly lower than that in the control group（P<0.05）. One month after follow-up, the recurrence of patients in the experimental group were 5 cases, while the control group were 11 cases, significant difference between the two groups（χ²=4.704, P=0.030）. Conclusion:Manual reduction combined with vestibular rehabilitation exercise can significantly improve the therapeutic effect of BPPV, ameliorate the residual dizziness symptoms and reduce the recurrence rate, meanwhile improve the balance function and quality life of patients.

[Results of microscopic examinations and blood slide re-examinations of malaria elimination evaluation in ten prefectures of Yunnan Province]

OBJECTIVE

To understand the laboratory technicians' abilities in blood slide making and reading in 10 prefectures of Yunnan Province which have passed the provincial malaria elimination evaluation, so as to provide the evidence for improving the malaria elimination surveillance and parasite examination.

METHODS

Thirty negative blood slides were randomly sampled to evaluate coating, dyeing and clean quality and reading results, and 4 laboratory technicians were sampled to evaluate their reading abilities from each prefecture level and its 2 subordinate counties (districts) respectively, and then the results were analyzed.

RESULTS

A total of 869 negative blood samples were evaluated. The coincidence rate was 100%. The proportions of good coating, dyeing and clean quality were 96.09%, 91.71% and 96.89%, respectively. Totally 576 blood slides were used to evaluate the reading ability. The number of correct reading was 505, and the correct rate was 87.67%. Among them, the Plasmodium vivax correct reading rate was 87.76%, the P. falciparum correct reading rate was 87.50%, and the correct reading rate of mixed infections was 47.62%. The laboratory technicians' ability to the mixed infections was significantly lower than the ability to the others (χ² = 37.169, P < 0.05), however, in the laboratory technicians' abilities, there was no significant difference among the center (s) for disease control and prevention, general hospitals and township hospitals (χ² = 2.782, P > 0.05), and the prefecture, county and township levels (χ² = 0.358, P > 0.05) .

CONCLUSIONS

The 10 prefectures have passed the provincial evaluation in blood slide making and microscopic examination skill indicators requested, but the medical and public health institutions at all levels still should further improve their laboratory technicians' abilities in blood slide making and microscopic examination skills.

[Related factors of diabetic nephropathy in patients with type 1 diabetes mellitus]

Objective: To analyze the related factors of diabetic nephropathy in inpatients with type 1 diabetes mellitus (T1DM). Methods: A total of 300 patients with T1DM who were treated in the Department of Endocrinology of Anhui Provincial Hospital between 2014 and 2016 were analyzed retrospectively. All the patients were divided into two groups according to their urine albumin-to-creatinine ratio: non-diabetic nephropathy group (n=193) and diabetic nephropathy group (n=107). Multivariate logistic regression analysis was adopted to analyze the factors related to diabetic nephropathy in T1DM, including the age, diabetic duration, body mass index (BMI) and glycosylated hemoglobin (HbA1c) of the two groups. Results: Age, diabetes duration, HbA1c, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol, triglyceride and uric acid (UA) of diabetic nephropathy group were higher than those of non-diabetic nephropathy group (all P<0.05). The total bilirubin, hemoglobin (Hb) and albumin in non-diabetic nephropathy group were higher than those in diabetic nephropathy group (P<0.05). The proportion of women in diabetic nephropathy group was higher than non-diabetic nephropathy group (62.6% vs 42.0%, P=0.001). Multivariate logistic regression analysis showed that diabetes duration (OR=2.142, 95% CI: 1.011-4.539), HbA1c (OR=1.262, 95% CI: 1.090-1.462), DBP (OR=1.048, 95% CI: 1.001-1.096), UA (OR=1.005, 95% CI: 1.001-1.009) and Hb (OR=0.952, 95% CI: 0.929-0.975) were independent related factors for diabetic nephropathy. Conclusions: Positive controlling of blood pressure, blood glucose, hyperuricemia and correcting anemia may reduce the incidence of diabetic nephropathy in T1DM patients.

Molecular dynamics studies of defect formation during heteroepitaxial growth of InGaN alloys on (0001) GaN surfaces

We investigate the formation of extended defects during molecular-dynamics (MD) simulations of GaN and InGaN growth on (0001) and ([Formula: see text]) wurtzite-GaN surfaces. The simulated growths are conducted on an atypically large scale by sequentially injecting nearly a million individual vapor-phase atoms towards a fixed GaN surface; we apply time-and-position-dependent boundary constraints that vary the ensemble treatments of the vapor-phase, the near-surface solid-phase, and the bulk-like regions of the growing layer. The simulations employ newly optimized Stillinger-Weber In-Ga-N-system potentials, wherein multiple binary and ternary structures are included in the underlying density-functional-theory training sets, allowing improved treatment of In-Ga-related atomic interactions. To examine the effect of growth conditions, we study a matrix of >30 different MD-growth simulations for a range of In _x Ga _1-x N-alloy compositions (0 ≤ x ≤ 0.4) and homologous growth temperatures [0.50 ≤ T/T^*_m (x) ≤ 0.90], where T^*_m (x) is the simulated melting point. Growths conducted on polar (0001) GaN substrates exhibit the formation of various extended defects including stacking faults/polymorphism, associated domain boundaries, surface roughness, dislocations, and voids. In contrast, selected growths conducted on semi-polar ([Formula: see text]) GaN, where the wurtzite-phase stacking sequence is revealed at the surface, exhibit the formation of far fewer stacking faults. We discuss variations in the defect formation with the MD growth conditions, and we compare the resulting simulated films to existing experimental observations in InGaN/GaN. While the palette of defects observed by MD closely resembles those observed in the past experiments, further work is needed to achieve truly predictive large-scale simulations of InGaN/GaN crystal growth using MD methodologies.

[Etiological analysis on patients in department of vertigo and dizziness oriented outpatient]

Objective: We aimed to explore the spectrum of causes for patients in department of vertigo and dizziness oriented outpatient, in order to provide a reference for diagnosis and treatment of patients with vertigo or dizziness. Methods: Retrospective analysis were carried out with clinical data of patients in our department of vertigo and dizziness oriented outpatient. The target group under study was diagnosed based on the uniform diagnostic criteria, and re-visiting patients were excluded. Results: This clinical study was conducted on 5 348 cases, who visited our vertigo and dizziness oriented outpatient from December 2012 to July 2015. The ratio of male to female was 1∶1.48, the age range was between 16 and 93. The frequencies of different etiology were: benign paroxysmal positional vertigo 1 902(35.56%), Chronic subjective dizziness 1 329(24.85%), vestibular migraine 624(11.67%), Meniere's disease 378(7.07%), multi-sensory neuropathy 231(4.32%), vestibular paroxysmia 177(3.31%), benign recurrent vestibulopathy 171(3.20%), presyncope 66(1.23%), posterior circulation ischemia 57(1.07%), vestibular neuritis 54(1.01%), sudden deafness complicated vertigo 36(0.67%), other reasons 68(1.27%), unknown 255(4.77%). Conclusions: Our study indicates that the precedent three causes for vertigo or dizziness are benign paroxysmal positional vertigo, chronic subjective dizziness and vestibular migraine, followed by Meniere's disease、multi-sensory neuropathy, vestibular paroxysmia and benign recurrent vestibulopathy. Presyncope, posterior circulation ischemia, vestibular neuritis and sudden deafness complicated vertigo are relatively infrequent. There are still a certain proportion of patients undetermined.

[Misdiagnosis and associated costs of benign paroxysmal positional vertigo]

Objective: The aims of this study were to investigate the misdiagnosis of benign paroxysmal positional vertigo (BPPV) and to estimate the associated costs. Methods: During October 2015 to December 2015, eighty patients were diagnosed with BPPV in the outpatient dizziness clinic of Shanghai Changzheng Hospital and the clinical data of all the 80 patients were collected including the demographic and clinical characteristics, the history of diagnosis, inappropriate diagnostic tests, costs of the medical tests, transportation and accommodation. All the data were investigated to estimate the misdiagnosis of benign paroxysmal positional vertigo and the associated costs in Shanghai, China. Results: This study showed that the misdiagnosis rate of BPPV was 60.0% (48/80) and the common inappropriate diagnostic tests for BPPV included Cranial CT and MRI test, cervical MRI, cervical and cerebrovascular investigations et al. There was no significant difference between the misdiagnosis patients (48) and patients without misdiagnosis (32) in gender, age, duration of symptom, involved canal and type of BPPV.Complications were significantly more frequent in the misdiagnosis group than for those without[81.3%(39 /48) vs 34.4%(11 /32)]. The estimated costs for each misdiagnosed individual were 8 502.98 China Yuan (CNY) and one-year economic burden associated with the misdiagnosis of BPPV in Shanghai was 13.184 7-78.862 1 million CNY. Conclusions: Our study suggests that the misdiagnosis rate of BPPV is high and the financial impact on patients and society with this disease is huge. The cost-effective Dix-Hallpike or supine roll test maneuver should be used before applying other expensive medical tests in order to minimize misdiagnosis and the waste of health care resources.

Agrobacterium tumefaciens-mediated genetic transformation of the Taxol-producing endophytic fungus Ozonium sp EFY21

An efficient Agrobacterium tumefaciens-mediated genetic transformation method was successfully established for a newly isolated Taxol-producing fungus, Ozonium sp EFY21. A specific hygromycin B resistance expression vector, pCAMBIA1304'AN7-1, was constructed for fungal transformation. Key factors affecting transformation efficiency were thoroughly investigated and optimized. PCR amplification and Southern hybridization were used to verify the transformation events. This study should pave the way for future genetic modification studies of Ozonium sp EFY21.

Knockdown of RhoGDIα induces apoptosis and increases lung cancer cell chemosensitivity to paclitaxel

This study aimed to investigate the effects of RhoGDIα knockdown on apoptosis and the chemosensitivity of lung cancer cells to paclitaxel. The signaling proteins involved were also assessed. RhoGDIα expression was assessed by RT-PCR, Western blotting and immunohistochemistry. Apoptosis was determined by flow cytometric assessment, and cell viability was measured with the MTT assay. Phosphorylation levels of signaling proteins, ERK, JNK, Akt, Bad and IκBα were tested by Western blotting and immunohistochemistry. Positivity for RhoGDIα in lung cancer tissues was significantly higher than in paracancerous tissues. Downregulation of RhoGDIα was associated with significantly increased apoptosis and repressed cell viability. This effect could be due to the consequent upregulation of p-JNK, as well as decreased levels of p-ERK, p-Bad and p-IκBα. Knockdown of RhoGDIα strengthened the effect on apoptosis and inhibition of cell viability induced by paclitaxel treatment. This chemosensitization effect could be a result of the intensification of pro-apoptotic JNK activation, and repression of anti-apoptotic p-ERK, p-Bad and p-IκBα expression stimulated by paclitaxel. In summary, our study indicated that RhoGDIα could be a promising therapeutic target, and the combination of RhoGDIα siRNA and paclitaxel might be a valuable potential therapy for lung cancer treatment.

Effects of nano-void density, size and spatial population on thermal conductivity: a case study of GaN crystal

The thermal conductivity of a crystal is sensitive to the presence of surfaces and nanoscale defects. While this opens tremendous opportunities to tailor thermal conductivity, true 'phonon engineering' of nanocrystals for a specific electronic or thermoelectric application can only be achieved when the dependence of thermal conductivity on the defect density, size and spatial population is understood and quantified. Unfortunately, experimental studies of the effects of nanoscale defects are quite challenging. While molecular dynamics simulations are effective in calculating thermal conductivity, the defect density range that can be explored with feasible computing resources is unrealistically high. As a result, previous work has not generated a fully detailed understanding of the dependence of thermal conductivity on nanoscale defects. Using GaN as an example, we have combined a physically motivated analytical model and highly converged large-scale molecular dynamics simulations to study the effects of defects on thermal conductivity. An analytical expression for thermal conductivity as a function of void density, size, and population has been derived and corroborated with the model, simulations, and experiments.

First Report of Tomato yellow leaf curl virus Infecting Common Bean in China

Common bean (Phaseolus vulgaris) is one of the most economically important vegetable crops in China. In November 2011, symptoms with thickening and crumpling of leaves and stunting were observed on common bean with incidence rate of 50 to 70% in the fields of Huaibei, northern Anhui Province, China. Diseased common bean plants were found to be infested with large population of whiteflies (Bemisia tabaci), which induced leaf crumple symptoms in healthy common beans, suggesting begomovirus etiology. To identify possible begomoviruses, 43 symptomatic leaf samples from nine fields were collected and total DNA of each sample was extracted. PCR was performed using degenerate primers PA and PB to amplify a specific region covering AV2 gene of DNA-A and part of the adjacent intergenic region (2). DNA fragments were successfully amplified from 37 out of 43 samples and PCR amplicons of 31 samples were used for sequencing. Sequence alignments among them showed that the nucleotide sequence identity ranged from 99 to 100%, which implied that only one type of begomovirus might be present. Based on the consensus sequences, a primer pair MB1AbF (ATGTGGGATCCACTTCTAAATGAATTTCC) and MB1AsR (GCGTCGACAGTGCAAGACAAACTACTTGGGGACC) was designed and used to amplify the circular viral DNA genome. The complete genome (Accession No. JQ326957) was 2,781 nucleotides long and had the highest sequence identity (over 99%) with Tomato yellow leaf curl virus (TYLCV; Accession Nos. GQ352537 and GU199587). These samples were also examined by dot immunobinding assay using monoclonal antibody against TYLCV and results confirmed that TYLCV was present in the samples. These results demonstrated that the virus from common bean is an isolate of TYLCV, a different virus from Tomato yellow leaf curl China virus (TYLCCNV). TYLCV is a devastating pathogen causing significant yield losses on tomato in China since 2006 (4). The virus has also been reported from cowpea in China (1) and in common bean in Spain (3). To our knowledge, this is the first report of TYLCV infecting common bean in China. References: (1) F. M. Dai et al. Plant Dis. 95:362, 2011. (2) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (3) J. Navas-Castillo et al. Plant Dis. 83:29, 1999. (4) J. B. Wu et al. Plant Dis. 90:1359, 2006.

Melt-growth dynamics in CdTe crystals

We use a new, quantum-mechanics-based bond-order potential (BOP) to reveal melt growth dynamics and fine scale defect formation mechanisms in CdTe crystals. Previous molecular dynamics simulations of semiconductors have shown qualitatively incorrect behavior due to the lack of an interatomic potential capable of predicting both crystalline growth and property trends of many transitional structures encountered during the melt→crystal transformation. Here, we demonstrate successful molecular dynamics simulations of melt growth in CdTe using a BOP that significantly improves over other potentials on property trends of different phases. Our simulations result in a detailed understanding of defect formation during the melt growth process. Equally important, we show that the new BOP enables defect formation mechanisms to be studied at a scale level comparable to empirical molecular dynamics simulation methods with a fidelity level approaching quantum-mechanical methods.

Decreased chaperone activity of alpha-crystallins in naphthalene-induced cataract possibly results from C-terminal truncation

Naphthalene-induced cataract has been extensively used to test potential anticataract drugs. Because the morphology as well as the toxic manifestations of naphthalene-induced cataract are reported to be similar to that of age-related cataract, naphthalene cataractogenesis in rats has been used as a valuable animal model to study the aetiology of age-related cataract in humans. This study aimed to determine whether the molecular chaperone activity of the alpha-crystallins was altered in naphthalene-induced cataract, and to clarify the possible mechanism for these changes. The data showed that the chaperone activity of the alpha-crystallins decreased in naphthalene-induced cataract. By mass spectrometry, C-terminal truncation of 16 amino acids and other post-translational modifications such as acetylation, phosphorylation, oxidation and carbamylation of the alpha-crystallins were detected. Furthermore, the results suggested that, at the proteomics level, naphthalene-induced cataract is a valuable animal model for the study of age-related cataract in humans.

Development of an effective sample preparation approach for proteomic analysis of silkworm eggs using two-dimensional gel electrophoresis and mass spectrometry

Sample preparation is still the first and important step toward successful two-dimensional gel electrophoresis (2DE) and identification in proteomics study. The 2DE profiling of eggs of silkworm species by using conventional one-step extraction, however, is unsatisfactory because high-abundance proteins such as egg-specific protein (ESP) and No 30 family (30 KP) in the extract lead to difficulties in detecting most of biologically relevant proteins. Based on the tendency of these abundant proteins to be soluble in Tris-HCl buffer, we report herein a robust approach in which the extract enriched in ESP and 30 KP was fractionationed and mixed with the re-extract of residual pellet in an optimal proportion. In comparison with the one-step method, the 2DE pattern was improved by this new method with over one-third enhancement in spots. A total of 48 unique proteins obtained have been furthermore identified by mass spectrometry (MS) and MS/MS. The identified proteins are found to include heat shock proteins families, ribosomal proteins, disulfide isomerase proteins, Glutathione S-transferase, and elongation factor, etc., which are mainly involved in some important processes. To our knowledge, this is the first time that the several proteins have been detected in silkworm eggs by proteomics means. This simple and reproducible approach would raise the opportunity of discovering and identifying more biomarkers and determining their possible roles in further studies.

Inhibition of protein phosphatase 2A- and protein phosphatase 1-induced tau hyperphosphorylation and impairment of spatial memory retention in rats

Tau hyperphosphorylation leads to formation of paired helical filament/neurofibrillary tangles, the hallmark lesion seen in Alzheimer's disease (AD) brain. An imbalanced regulation in protein kinases and protein phosphatases in the affected neurons is proposed to be a reasonable causative factor to the disease process. To verify the hypothesis, we have injected in the present study calyculin A, a potent and specific inhibitor of protein phosphatase (PP) 2A and PP1, into rat hippocampus bilaterally, thus reproduced an Alzheimer's-like deficiency in dephosphorylation system. It was found that calyculin A-injected rats developed lesions in spatial memory retention in Morris water maze test. At mean time, tau was hyperphosphorylated at Ser396/Ser404 (PHF-1) and Ser-262/Ser-356 (12E8) sites determined both by immunohistochemistry and Western blot. It is implicated that (1) PP2A and PP1 participate in the in vivo regulation of tau phosphorylation, and down-regulation of the two phosphatases will result in tau hyperphosphorylation; (2) hyperphosphorylation of tau at PHF-1 and 12E8 sites might be crucial to affect spatial memory in AD.

Decreased expression of cellular prostatic acid phosphatase increases tumorigenicity of human prostate cancer cells

PURPOSE

Understanding cell proliferation regulation in hormone refractory prostate cancer may provide answers for novel solutions. Protein tyrosine phosphatases have been thought to have key roles in regulating cell proliferation and be involved in oncogenesis, although to our knowledge their functional roles in human prostate cancer remain unknown. Human prostatic acid phosphatase (PAcP), a major phosphatase in prostate epithelium, has been shown to function as a neutral protein tyrosine phosphatase in these cells. We evaluated the biological significance of cellular prostatic acid phosphatase expression in human prostate cancer cells.

MATERIALS AND METHODS

Immunohistochemical testing of human prostate cancer archival specimens was done to evaluate the expression of cellular PAcP. Immunoprecipitation and immunoblotting were performed to determine cellular PAcP and SH2 domain-bearing tyrosine phosphatase-1 levels as well as tyrosine phosphorylation of c-ErbB-2/neu in different human prostate cancer cells. The biological behavior of LNCaP derivative sublines was characterized in vitro and in vivo by soft agar analysis and xenograft animal inoculation.

RESULTS

Immunohistochemical staining of human prostate clearly showed that cellular levels of PAcP significantly decreases in prostate cancer cells (p <0.001). The results of biochemical characterization revealed that the cellular level of PAcP but not SHP-1, another differentiation associated protein tyrosine phosphatase, consistently correlated negatively with the growth of several human prostate cancer cell lines. Reintroducing cellular PAcP activity in prostate cancer cells by PAcP complementary DNA transfection resulted in decreased tyrosine phosphorylation of c-ErbB-2/neu, decreased proliferation rates in culture as well as decreased anchorage independent growth in soft agar. The xenograft animal model demonstrated that a higher tumor growth rate as well as larger size is associated with a lower level of cellular PAcP.

CONCLUSIONS

Cellular PAcP can down-regulate prostate cancer cell growth, at least partially by dephosphorylating c-ErbB-2/neu. Therefore, decreased cellular PAcP expression in cancer cells may be involved in prostate cancer progression.

[Calcineurin signaling pathway is involved in cardiomyocyte hypertrophy mediated by calcium activators]

AIM

To investigate the effects of intracellular free calcium ([Ca2+]i) from different resources on calcineurin (CaN) dependent signaling pathway and cardiomyocyte hypertrophy.

METHODS

Angiotensin II (Ang II,10(-7) mol/L), ryanodine (RY, 10(-7) mol/L), inositol (1,4,5)-trisphosphate (IP3, 10(-7) mol/L) were applied to stimulate the [Ca2+]i, CaN activity and protein expression were measured in primary cultured cardiomyocytes from Wistar rat. [Ca2+]i was measured using Fura-2/AM fluorescent technique. The incorporation of 3H-Leucine (3H-Leu) determined the synthesis rates of protein.

RESULTS

Ang II, RY and IP3 increased [Ca2+]i, promoted CaN activity and protein expression, and 3H-Leu incorporation in cultured cardiomyocytes compared with control (P < 0.05 or P < 0.01).

CONCLUSION

Cardiomyocyte hypertrophy is associated with the changes of cellular [Ca2+]i, but not with its resources. Indicating that CaN signaling pathway play an important role in the hypertrophy of cardiomyocytes.

Effects of oxodiperoxovanadate (V) complexes on the activity of green crab (Scylla serrata) alkaline phosphatase

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme that catalyzes the nonspecific hydrolysis of phosphate monoesters. The effects of some pollutants in seawater on the activity of the enzyme will result in the loss of the biological function of the enzyme, which will affect the exuviating crab shell and threaten the survival of the animal. In the present paper, the effects of four oxodiperoxovanadate (V) complexes on the activity of green crab alkaline phosphatase have been studied. The results show that these vanadate derivatives can lead to reversible inactivation. The equilibrium constants for binding of inhibitors with the enzyme and/or the enzyme-substrate complexes have been determined. The results show that sodium (2,2;-bipyridine)oxodiperoxovanadate, pV(bipy), and potassium oxodiperoxo-(1,10-phenanthroline)vanadate, pV(phen), are competitive inhibitors, while potassium picolinato-oxodiperoxo-vanadate, pV(pic), and oxalato-oxodiperoxovanadate, pV(ox), are mixed-type inhibitors. These results suggest that pV(bipy) is a considerably more potent competitive inhibitor than pV(phen) and that the competitive inhibition effect of pV(pic) is stronger than that of pV(ox), but the non-competitive inhibition effect of pV(ox) is stronger than that of pV(pic).

Kinetics of inhibition of beta-glucosidase from Ampullarium crossean by bromoacetic acid

The kinetics of inhibition of beta-glucosidase from Ampullarium crossean by bromoacetic acid (BrAc) has been studied. The results show that the enzyme can be irreversibly and completely inactivated at high BrAc concentration, while at low BrAc concentration, inhibition of the enzyme is a slow, reversible reaction. The microscopic rate constants for the reactions of BrAc with the enzyme were determined. The presence of the substrate offers obvious protection of the enzyme against inhibition by BrAc. The above results suggest that the histidine residue is essential for activity and is situated at or near the active site of the enzyme.

Kinetics of inhibition of green crab (Scylla serrata) alkaline phosphatase by sodium (2,2'-bipyridine) oxodiperoxovanadate

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, which catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics of inhibition of the enzyme by sodium (2, 2'-bipyridine) oxodiperoxovanadate, pV(bipy), has been studied. The time course of the hydrolysis of p-nitrophenyl-phosphate catalyzed by the enzyme in the presence of different pV(bipy) concentrations showed that at each pV(bipy) concentration, the rate decreased with increasing time until a straight line was approached, the straight line slopes are the same for all concentrations. The results suggest that the inhibition of the enzyme by pV(bipy) is a slow, reversible reaction with fractional remaining activity. The microscopic rate constants are determined for the reaction of inhibitor with the enzyme.

Identification of a pore lining segment in gap junction hemichannels

The ability of certain connexins to form open hemichannels has been exploited to study the pore structure of gap junction (hemi)channels. Cysteine scanning mutagenesis was applied to cx46 and to a chimeric connexin, cx32E(1)43, which both form patent hemichannels when expressed in Xenopus oocytes. The thiol reagent maleimido-butyryl-biocytin was used to probe 12 cysteine replacement mutants in the first transmembrane segment and two in the amino-terminal segment. Maleimido-butyryl-biocytin was found to inhibit channel activity with cysteines in two equivalent positions in both connexins: I33C and M34C in cx32E(1)43 and I34C and L35C in cx46. These two positions in the first transmembrane segment are thus accessible from the extracellular space and consequently appear to contribute to the pore lining. The data also suggest that the pore structure is complex and may involve more than one transmembrane segment.

A chimeric connexin forming gap junction hemichannels

Connexins are the subunits of gap junction channels which connect neighboring cells. With the exception of lens connexins, they usually do not form open hemichannels in the cell membrane of single cells. Here we describe a chimeric connexin consisting of cx32 where the first extracellular loop sequence is replaced by the corresponding cx43 sequence. This chimera, cx32E143, forms conventional gap junction channels in the paired oocyte assay. In addition cx32E143 induces a membrane conductance in single oocytes. This membrane conductance is voltage dependent and is similarly sensitive to CO2 as are gap junction channels formed by the chimera or by wild-type cx32. These data suggest that cx32E143 forms patent hemichannels in the plasma membrane of single oocytes. This conclusion is further supported by the observation that oocytes expressing cx32E143 take up from the bath medium tracer molecules known to pass through gap junction channels.