Mother-to-Child Transmission of HBV Infection by Preventive Interventions in Southern Vietnam's Hospitals

INTRODUCTION

The World Health Organization (WHO) recommends tenofovir disoproxil fumarate (TDF) for pregnant women with hepatitis B virus (HBV) presenting with HBV DNA levels of 106 copies/mL or more to hinder mother-to-child transmission (MTCT). Moreover, it is suggested that neonates of HBV-infected mothers receive an HBV vaccine birth dose within 24 hours of birth to mitigate transmission risk.

METHODOLOGY

The study included 661 HBV-infected pregnant women and 316 infants from 3 hospitals in Southern Vietnam between October 2019 and November 2020. Infants were classified on the basis of their mothers' TDF prophylaxis into I-TDF (+) group (107 infants) whose mothers received TDF; I-TDF (-) group (56 infants) whose mothers missed TDF; and I-NTDF group (153 infants) whose mothers did not necessitate TDF. Almost all infants received an HBV vaccine birth dose with HBIG administered on the basis of parents' financial standing.

RESULTS

MTCT was found in 2.2% of the cases. The respective MTCT rates for I-TDF (+), I-TDF (-), and I-NTDF groups were 2.8%, 5.4%, and 0.7%. Immune response rates to the HBV vaccination in the total cohort, I-TDF (+), I-TDF (-), and I-NTDF groups, were 88.6%, 87.9%, 85.7%, and 90.2%, respectively. Vaccinated infants exhibited a statistically lower risk of HBV infection postbirth (aRR = 0.1; 95% confidence interval, 0.0-0.6; P = .01).

CONCLUSION

TDF can equate the MTCT risk in pregnant women with HBV DNA levels of 106 copies/mL or more to those with lower levels. Early administration of the HBV vaccine postbirth also effectively curtails MTCT. Thus, expanding TDF prophylaxis and vaccine coverage is pivotal to impede MTCT.

HBeAg testing is better than quantitative HBsAg assay as an alternative to HBV DNA assay among HBV-infected pregnant women

INTRODUCTION

Using tenofovir disoproxil fumarate (TDF) is recommended in the 3rd trimester for pregnant women with HBV DNA ≥ 200,000 IU/mL to prevent mother-to-child transmission (MTCT) of hepatitis B virus (HBV). However, HBV DNA quantification is unavailable in many resource-limited areas worldwide, hence prophylaxis is often missed. The aim of this study was to determine whether HBeAg or qHBsAg is a better alternative to HBV DNA testing in HBV-infected pregnant women.

METHODOLOGY

In this prospective cohort study, pregnant women with HBV infection were recruited in 3 hospitals from October 2019 to November 2020. Socio-demographic and clinical data were collected. Blood samples were taken for qHBsAg and HBV DNA testing. HBeAg results were collected from the medical records of the participants who visited a doctor during the study.

RESULTS

465 pregnant women met the study criteria. 41.9% were HBeAg positive, 33.3% had high qHBsAg levels (> 104 IU/mL), 38.3% had high HBV DNA levels (≥ 200,000 IU/mL). Pregnant women with high qHBsAg levels were 27 times more likely to have high HBV DNA levels (aOR = 27.0, 95% CI: 11.1-65.5, p < 0.001). Participants who were HBeAg positive were 57.5 times more likely to have high HBV DNA levels (aOR = 57.5, 95% CI: 23.0-140.0, p < 0.001). The sensitivity of qHBsAg and HBeAg was 80% and 94%, respectively; and specificity was 95% and 90%, respectively.

CONCLUSIONS

HBeAg testing should be considered over qHBsAg assay as an alternative to HBV DNA assay because of its technical simplicity, lower cost, and fewer missed treatments.

Removal of Acid Orange G Azo Dye by Polycation-Modified Alpha Alumina Nanoparticles

Highly positively charged poly(vinyl benzyl trimethylammonium chloride) (PVBMA) was successfully synthesized with approximately 82% of yield. The PVBMA was characterized by the molecular weight (Mw ) of 343.45 g mol-1 and the molecular weight distribution, (Đ) of 2.4 by 1 H NMR and SEC measurements. The PVBMA was applied as an effective agent for α-Al2 O3 surface modification in the adsorptive removal of the azo dye acid orange G (AOG). The AOG removal performance was significantly enhanced at all pH compared to without surface modification. The experimental parameters were optimal at pH 8, free ionic strength, 15 min of adsorption time, and 5 mg mL-1 α-Al2 O3 adsorbents. The AOG adsorption which was mainly controlled by the PVBMA-AOG electrostatic attractions was better applicable to the Langmuir isotherm and the pseudo-second kinetic model. The PVBMA-modified α-Al2 O3 demonstrates a high-performance and highly reusable adsorbent with great AOG performances of approximately 90.1% after 6 reused cycles.

Effect of a peer-led education intervention on dietary behaviour and physical activity among adolescents in Ho Chi Minh City, Vietnam: a pilot study

This pilot study aimed to evaluate the effectiveness of peer-led education intervention on physical activity, sedentary behaviours, and dietary behaviours among adolescents in HCM city, Vietnam. Among students in the intervention arm after a 9-month follow-up, total energy intake was reduced by 304 kcal/day, fat by 13 g/day, carbohydrate by 39 g/day, and sweet foods by 20 g/day, compared to pre-intervention figures (p < 0.05, adjusted for age, BMI at baseline, gender, the interaction between measurement time and intervention groups, and cluster effect in schools). Only total energy intake was significantly lower in the intervention than control students (p < 0.05, after adjustment). Our pilot project has established the feasibility of a peer-led intervention to improve lifestyles among adolescents in HCM city and evidence of improvements in dietary intake. Australian New Zealand Clinical Trials Registry: ACTRN12619000421134.

Plastic pollution in the surface water in Jakarta, Indonesia

Plastic pollution in the ocean primarily originates from the land-derived mismanaged plastic waste that is transported by rivers. This study aimed to estimate the plastic litter generation in the surface water in Jakarta and Indonesia. A field survey was conducted at six riverine sampling points (upstream to downstream) and three holding facilities of the litter in Jakarta during the rainy season. The Jakarta Open Data database was used to estimate the tonnage of plastic litter. By mass, plastic comprised approximately 74 % of the anthropogenic litter in rivers and 87 % in holding facilities. The riverine plastic proportion slightly increased downstream. Approximately 9.9 g/person/day of plastic litter was discharged into Jakarta's surface water during rainy season and recovered by floating booms. To reduce plastic pollution and its severe impacts on aquatic ecosystems and human health, further field investigation is necessary to design an effective clean-up system and litter-prevention strategy.

Impoverishing effect of tobacco use in Vietnam

BACKGROUND

Tobacco consumption places a significant economic burden on households, which is particularly severe in developing countries like Vietnam. In a country where the social insurance system is weak and healthcare is often expensive, tobacco-consuming households may face a higher risk of living in poverty. Some evidence on the social consequences of tobacco consumption suggests that it might aggravate poverty and inequality in Vietnam; however, to the best of our knowledge, no research provides a reliable estimate of the impoverishing effect of tobacco use in the country thus far.

OBJECTIVES

This study quantifies the direct impact of tobacco use on poverty, measured by a poverty head count and the total size of the poverty gap in Vietnam in 2018.

METHODS

By deducting tobacco-related expenditure from the total household income, the authors recalculate the actual household disposable income and examine whether the households suffer from the state of secondary poverty. Data from the 2018 Vietnam Household Living Standards Survey were used for calculation.

RESULTS

(1) Total tobacco-related expenditure increased the number of poor people by 305 090 (0.31% of the country's population) in 2018. More than one-third of those impoverished people are children, who should be considered victims of adults' tobacco use. (2) Tobacco use increased the poverty gap by 0.08 percentage points from 2.20% to 2.28%. (3) The impoverishment effects of tobacco consumption vary across groups in society and appear to be more intense in rural areas, among ethnic minorities and in the two lowest quintiles of consumption.

CONCLUSION

This study confirms the impoverishing effect of tobacco use in Vietnam (305 090 people) and that the effects are heterogeneous across population groups. Therefore, controlling tobacco use should be a part of the broader poverty reduction strategy in Vietnam and should be wisely targeted so as to reduce poverty effectively.

A randomised controlled trial of a novel tramadol chewable tablet: pharmacokinetics and tolerability in children

Tramadol is a bitter atypical opioid analgesic drug and is prescribed to treat postoperative pain in children. However, in many countries there is no licensed paediatric tramadol formulation available. We have formulated a novel chewable chocolate-based drug delivery system for the administration of tramadol to children. This pilot, single-centre, open-label, randomised clinical study assessed the taste tolerability and comparative population pharmacokinetics of the novel tramadol chewable tablet against a compounded tramadol hydrochloride oral liquid, at a dose of 1 mg.kg^-1 . A 5-point facial hedonic scale was used by the children, parents and nurses to assess tolerability. One hundred and forty-one children aged 3-16 years were given tramadol 30 min before general anaesthesia. Blood samples were taken following the induction of anaesthesia and for up to 5 h following tramadol administration. Tramadol and its active metabolite O-desmethyltramadol were analysed using reversed-phase high-performance liquid chromatography. A population pharmacokinetic model was built using non-linear mixed effects modelling. The relative bioavailability for the tablet was 1.25 times higher (95%CI 1.16-1.35) than for tramadol hydrochloride oral liquid, while the absorption rate constant for the tablet was significantly lower (1.97 h^-1 vs. 3.34 h^-1 , p < 0.001). Larger inter-individual variability in absorption rates were observed with the liquid tramadol. The tramadol chewable tablet was more acceptable in taste to children when assessed by the children, parents and nurses (all p < 0.001). We conclude that the novel tramadol chewable tablet has favourable acceptability and more reliable relative bioavailability in children compared with tramadol hydrochloride oral liquid.

HPLC-UV assay of tramadol and O-desmethyltramadol in human plasma containing other drugs potentially co-administered to participants in a paediatric population pharmacokinetic study

Multimodal analgesia is employed in paediatric pain management to maximise analgesia and minimise side effects. Tramadol is dosed at 1-1.5 mg/kg to treat severe pain in children but the assay for tramadol in plasma samples for pharmacokinetic and toxicology studies does not often consider concurrently administered medications. In this study we developed and validated an HPLC-UV method to quantify tramadol and its main metabolite (O-desmethyltramadol) in human plasma in the presence of seven potentially interfering drugs. Sample preparation method was developed by combining liquid-liquid extraction and protein precipitation. Chromatographic separation was achieved on a BDS-Hypersil-C18 column (5 µm, 250 × 4.6 mm) using a double gradient method. The limit of quantification was 6.7 ng/ml for both tramadol and ODT. The precision and accuracy were in compliance with ICH guidelines. This method was successfully employed to analyse the blood samples of 137 paediatric participants in a tramadol pharmacokinetic trial.

Unattended automated office blood pressure in living donor kidney transplant recipients

PURPOSE

Hypertension is common in kidney transplant recipients (KTRs). For the evaluation of blood pressure (BP), 24-h ambulatory BP measurements (ABPM) are considered superior to usual office measurements but are also resource demanding and troublesome to many patients. We therefore evaluated the use of unattended automated office BP (AOBP) during the first year following living donor kidney transplantation and compared AOBP with ABPM as obtained 12 months after transplantation.

MATERIALS AND METHODS

Data were retrieved from a cohort of 57 KTRs (mean age 45 ± 14 years, 75% males) who all received kidneys from living donors and had a good graft function (estimated glomerular filtration rate (eGFR) 52 ± 16 ml/min/1.73 m² at 12 months). Unattended AOBP was measured at each visit to the outpatient clinic using the BpTru® device, while ABPM was obtained by Spacelabs® equipment before and 12 months after transplantation.

RESULTS

AOBP remained stable from month 2 (130.2 ± 10.8/82.2 ± 7.8 mmHg) to month 12 (129.0 ± 12.8/83.1 ± 9.6 mmHg) post-transplantation. At 12 months follow-up, ambulatory daytime systolic BP was slightly higher than AOBP (132.7 ± 10.7 vs. 129.4 ± 12.2 mmHg, p = 0.04), while diastolic BP was similar (82.7 ± 7.7 vs. 82.0 ± 10.2 mmHg). Using Bland-Altman plots, 95% limits of agreements were -17.9 to 24.5 mmHg for systolic and -16.5 to 15.1 mmHg for diastolic BP. When considering a target BP of ≤130/<80 mmHg, 62% had sustained hypertension, 9% white coat hypertension and 11% masked hypertension. Using multiple linear regression analysis, only urine albumin-creatinine ratio tended to predict a higher systolic AOBP (p = 0.07).

CONCLUSION

In a cohort of stable living donor KTRs, mean values of unattended AOBP using BpTru® are comparable to daytime ABPM with a misclassification rate of approximately 20%.

Prior administration of chocolate improves the palatability of bitter drugs: The Choc-with-Med study

AIM

The paediatric population has a low adherence and acceptance rate of unpalatable medicines. This study aimed to determine whether eating chocolate immediately prior to drug administration would help to mask the bitter taste of a drug. The difference in taste masking efficacy between white, milk and dark chocolate was a secondary measure outcome.

METHODS

A controlled repeated measures crossover taste trial was conducted using a taste panel of 29 young healthy adults who met the criteria to differentiate intensity in bitterness taste. Participants separately tasted solutions of quinine, flucloxacillin and clindamycin using the swill and spit method, singularly and following blinded prior administration of white, milk or dark chocolate. Drug solutions administered without prior chocolate served as controls. Bitterness score for each tasting was recorded using a 5-point scale.

RESULTS

Regardless of chocolate type, mean taste scores with prior chocolate for quinine (range 2.00-2.34), clindamycin (3.72-3.83) and flucloxacillin (3.38-3.45) were all lower than mean scores for respective drugs without chocolate (3.24, 4.75 and 4.28, respectively; P < 0.0001 for all comparisons). Dark chocolate was most efficacious for masking the bitter taste of quinine, but the differences in taste masking efficacy between dark, milk and white chocolates were not statistically significant for flucloxacillin and clindamycin.

CONCLUSIONS

Prior administration of chocolate results in lower perceived bitterness compared to control tastings of quinine, flucloxacillin and clindamycin solutions; however, there is no clear difference in this effect between the dark, milk and white chocolates used in this study.

Maternal and neonatal outcomes related to Zika virus in pregnant women in Southern Vietnam: An epidemiological and virological prospective analysis

Background

In 2016-2017, 68 women in Southern Vietnam had RT-PCR confirmed Zika virus (ZIKV) infection during pregnancy. We report here the outcomes of the pregnancies and the virological analyses related to this outbreak.

Methods

We collected clinical and epidemiological information from the women who were enrolled in the study. Medical records related to the pregnancy in 2016-2017 were retrieved for those who were not able to be enrolled in the study. Children born to women with ZIKV infection during pregnancy were also enrolled. Serum samples were evaluated for presence of ZIKV antibodies. Phylogenetic analyses were performed on Zika virus genomes sequenced from the 2016-2017 serum samples.

Findings

Of the 68 pregnancies, 58 were livebirths and 10 were medically terminated. Four of the medical records from cases of fetal demise were able to be retrieved, of which one was consistent with congenital ZIKV infection. Of the 58 women with a livebirth, 21 participated in the follow-up investigation. All but two women had serologic evidence of ZIKV infection. Of the 21 children included in the study (mean age: 30.3 months), 3 had microcephaly at birth. No other clinical abnormalities were reported and no differences in neurodevelopment were observed compared to a control group. Phylogenetic analysis revealed a clade within the ZIKV Asian lineage and branch at the root of samples from the 2013-2014 French Polynesian outbreak. The prM S139N mutation was not observed.

Interpretation

We have been able to demonstrate a clade within the ZIKV Asian lineage implicated in adverse pregnancy outcomes in Southern Vietnam.

Funding

INCEPTION project (PIA/ANR-16-CONV-0005) and a grant received from BNP Paribas Simplidon.

Prospective One Health genetic surveillance in Vietnam identifies distinct blaCTX-M-harbouring Escherichia coli in food-chain and human-derived samples

OBJECTIVES

We performed a One Health surveillance in Hanoi-a region with a high-density human population and livestock production, and a recognized hotspot of animal-associated antimicrobial resistance (AMR)-to study the contribution of bla_CTX-M-carrying Escherichia coli and plasmids from food-animal sources in causing human community-acquired urinary tract infections (CA-UTIs).

METHODS

During 2014-2015, 9090 samples were collected from CA-UTI patients (urine, n = 8564), pigs/chickens from farms and slaughterhouses (faeces, carcasses, n = 448), and from the slaughterhouse environment (surface swabs, water, n = 78). E. coli was identified in 2084 samples. Extended-spectrum β-lactamase (ESBL) production was confirmed in 235 and bla_CTX-M in 198 strains by PCR with short-read plasmid sequencing. Fourteen strains were long-read sequenced to enable plasmid reconstruction.

RESULTS

The majority of the ESBL-producing E. coli strains harboured bla_CTX-M (n = 198/235, 84%). High clonal diversity (48 sequence types, STs) and distinct, dominant STs in human sources (ST1193, n = 38/137; ST131, n = 30/137) and non-human sources (ST155, n = 25/61) indicated lack of clonal transmission between habitats. Eight bla_CTX-M variants were identified; five were present in at least two sample sources. Human and food-animal strains did not show similar plasmids carrying shared bla_CTX-M genes. However, IS6 elements flanking ISEcp1-bla_CTX-M-orf477/IS903B structures were common across habitats.

CONCLUSIONS

In this study, animal-associated bla_CTX-ME. coli strains or bla_CTX-M plasmids were not direct sources of CA-UTIs or ESBL resistance in humans, respectively, suggesting evolutionary bottlenecks to their adaptation to a new host species. Presence of common IS6 elements flanking bla_CTX-M variants in different plasmid backbones, however, highlighted the potential of these transposable elements for AMR transmission either within or across habitats.

1183Beta-Adrenoceptor activation increases cardiac galectin-3 levels via the hippo signaling pathway

Background

Galectin-3 (Gal-3) is a clinical biomarker for risk of cardiovascular disease and a disease mediator forming a therapeutic target. However, the mechanism(s) that regulate cardiac expression of Gal-3 remains unknown. Activation of the sympatho-β-adrenergic system is a hallmark of heart disease, but the relationship of βAR activation and cardiac content of Gal-3 remains unknown.

Purpose

To determine the role of βAR activation in regulating cardiac Gal-3 level and the responsible mechanism focusing on the Hippo signalling pathway.

Methods

Wild-type and Gal-3 gene deleted (Gal3-KO) mice were used. To test the role of the Hippo pathway, we used transgenic (TG) mouse strains with cardiac overexpression of mammalian-20-like sterile kinase 1 (Mst1, mammalian orthology of Drosophila Hippo kinase) either in wild-type form (TG-Mst1) or dominative-negative kinase dead mutant form (TG-dnMst1). Effects of β-antagonist (isoprenaline, ISO) and antagonists were determined. We measured phosphorylation (Ser127) of YAP as a transcription co-regulator acting as the main signal output of the Hippo pathway.

Results

In wild-type mice, treatment with ISO led to a time- and dose-dependent increase in cardiac expression of Gal-3 (Fig. A) accompanied by elevated circulating Gal-3 levels (Fig. B). ISO treatment stimulated cardiac expression of Mst1 and YAP hyper-phosphorylation (i.e. inactivation, Fig. C), indicating activation of the Hippo signalling. These effects of ISO were inhibited by β-blockers (propranolol, Prop; carvedilol, Carv; Fig. D,E). Relative to non-TG controls, ISO-induced expression of Gal-3 was inhibited by 75% in TG-dnMst1 mice (inactivated Mst1), but exaggerated by 7-fold in TG-Mst1 mice (activated Mst1). Mst1-TG mice had a 45-fold increase in Gal-3 content, YAP hyper-phosphorylation and enhanced pro-fibrotic signaling. In Mst1-TG mice, whilst blood Gal-3 level was unchanged, treatment with ISO (6 mg, 2 days) evoked a marked increase in cardiac and blood Gal-3 levels. Using rat cardiomyoblasts, we showed that ISO-mediated Mst1 expression and YAP phosphorylation were PKA-dependent and that siRNA-mediated YAP knockdown led to Gal-3 upregulation. The role of Gal-3 in mediating ISO-induced cardiomyopathy was examined by treating wild-type and Gal3-KO mice with ISO (30 mg/kg, 7 days). ISO-treated wild-type mice had 8-fold increase in cardiac Gal-3, ventricular dysfunction, fibrosis, hypertrophy and activated inflammatory or fibrotic signalling. All these changes, except hypertrophy, were abolished by Gal3-KO.

beta-AR regulates galectin-3

Conclusion

βAR stimulation increases cardiac expression of Gal-3 through activation of the Hippo signalling pathway. This is accompanied by elevated circulating Gal-3 level. βAR antagonists inhibited βAR-Mst1 (Hippo) signalling and cardiac Gal-3 expression, actions likely contributing to the overall efficacy of β-blockers.

Acknowledgement/Funding

NHMRC of Australia; Nature Science Fund of China

Z-Axis Micromachined Tuning Fork Gyroscope with Low Air Damping

This paper reports on the design and fabrication of a z-axis tuning fork gyroscope which has a freestanding architecture. In order to improve the performance of the tuning fork gyroscope by eliminating the influence of the squeeze-film air damping, the driving and sensing parts of the gyroscope were designed to oscillate in-plane. Furthermore, by removing the substrate underneath the device, the slide-film air damping in the gap between the proof masses and the substrate was eliminated. The proposed architecture was analyzed by the finite element method using ANSYS software. The simulated frequencies of the driving and sensing modes were 9.788 and 9.761 kHz, respectively. The gyroscope was fabricated using bulk micromachining technology. The quality factor and sensitivity of the gyroscope operating in atmospheric conditions were measured to be 111.2 and 11.56 mV/°/s, respectively.

Deubiquitylating enzyme, USP9X, regulates proliferation of cells of head and neck cancer lines

OBJECTIVES

Truncating mutations in USP9X have been identified in oral squamous cell carcinoma patients. The aim of this study was to determine USP9X's functional role, if any, in head and neck cancer cells.

MATERIALS AND METHODS

USP9X was depleted/overexpressed in head and neck cancer cell line: SCC15 (tongue), CAL27 (tongue), FaDu (pharynx) and Detroit 562 (pharynx). Cell proliferation was monitored using the CyQUANT assay, and cell cycle distribution was determined by flow cytometry. Immunoblot assays were conducted to assess protein levels. RT-qPCR was performed to determine Notch and Wnt pathway target gene expression.

RESULTS

Our data showed a direct correlation between USP9X protein levels and proliferation, as well as Notch pathway activity in head and neck cancer cells. However, at least in FaDu, USP9X did not appear to regulate proliferation through the Notch pathway. Immunoblotting revealed a dramatic reduction in downstream targets of mTOR complex 1, namely total ribosomal protein (S6) and its phosphorylated form (pS6), when USP9X was depleted in FaDu cells. In contrast, in immortalized but non-tumorigenic HaCaT keratinocytes, USP9X depletion led to increase in cell proliferation, maintaining direct regulation of Notch activity.

CONCLUSIONS

The functional role of USP9X was found to be context dependent. USP9X possibly promotes head and neck cancer cell proliferation through the mTOR pathway.

Vancomycin Functionalized Nanoparticles for Bactericidal Biomaterial Surfaces

In this paper, we describe a simple and powerful way to synthesize antibacterial biomaterials with applications as implants in orthopedic surgery. Such implants are obtained by covalently grafting onto the Ti90A16 V4 alloy surface with vancomycin-functionalized nanoparticles. Nanoparticles were produced by ring-opening metathesis polymerization of α-norbornenyl-ω-vancomycin poly(ethylene oxide) macromonomers. Vancomycin is an interesting candidate because of its use in the field of implant associated infection as it is a glycopeptide which acts on bacterial walls. As a consequence, vancomycin does not need to be released for it to be active. In the first part of this paper, the synthesis and the complete characterization of these materials are described. In a second part, the in vitro antibacterial behavior is analyzed and discussed.

Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

Release of potassium accompanying the dissolution of rice straw phytolith

In rice, Si assimilated from the soil solution is deposited in inter- and intracellular spaces throughout the leaf and stems to form silicified structures (so-called phytoliths). Because K is also present in significant concentrations in rice stems and leaves, the question arises if K is immobilized in the mineralized silica during the precipitation of Si. This work determined whether desilification of the phytolith is a factor regulating K release by implementing batch experiments. Solubility of Si and K of the rice straw heated at different temperatures were examined to identify effect of pretreatment. Analyses of phytoliths using SEM-EDX and X-ray tomographic microscopy in conjunction with the results from batch experiments revealed that K might co-exist with occluded organic matter inside the phytolith structure. In the kinetic experiments, corresponding increases of K and Si concentrations in the supernatants were observed which suggested that desilification of the phytolith is a main factor regulating K release. The extent of heat pretreatment of the rice straw is of significant importance with respect to dissolution of the phytolith by affecting organic removal and surface modification. At temperatures lower than 600 °C, corresponding increases of the soluble Si and K with heating temperature have been obviously observed. In contrast, the solubility of Si and K gradually decreased at temperatures above 600 °C. This work provides insights into factors that control release of K and Si from phytolith and a practical recommendation for practices of burning rice straw that may maximize subsequent release of Si and K for crops.

2,3,7,8-Tetrachlorodibenzo-p-dioxin in breast milk increases autistic traits of 3-year-old children in Vietnam

Dioxin levels in the breast milk of mothers residing near a contaminated former airbase in Vietnam remain much higher than in unsprayed areas, suggesting high perinatal dioxin exposure for their infants. The present study investigated the association of perinatal dioxin exposure with autistic traits in 153 3-year-old children living in a contaminated area in Vietnam. The children were followed up from birth using the neurodevelopmental battery Bayley-III. The high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposed groups (⩾3.5 pg per g fat) showed significantly higher Autism Spectrum Rating Scale (ASRS) scores for both boys and girls than the mild-TCDD exposed groups, without differences in neurodevelopmental scores. In contrast, the high total dioxin-exposed group, indicated by polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs)--the toxic equivalents (TEQ) levels⩾17.9 pg-TEQ per g fat, had significantly lower neurodevelopmental scores than the mild-exposed group in boys, but there was no difference in the ASRS scores. The present study demonstrates a specific impact of perinatal TCDD on autistic traits in childhood, which is different from the neurotoxicity of total dioxins (PCDDs/Fs).

High basal NF-κB activity in nonpigmented melanoma cells is associated with an enhanced sensitivity to vitamin D3 derivatives

Background:

Melanoma is highly resistant to current modalities of therapy, with the extent of pigmentation playing an important role in therapeutic resistance. Nuclear factor-κB (NF-κB) is constitutively activated in melanoma and can serve as a molecular target for cancer therapy and steroid/secosteroid action.

Methods:

Cultured melanoma cells were used for mechanistic studies on NF-κB activity, utilising immunofluorescence, western blotting, EMSA, ELISA, gene reporter, and estimated DNA synthesis assays. Formalin-fixed, paraffin-embedded specimens from melanoma patients were used for immunocytochemical analysis of NF-κB activity in situ.

Results:

Novel 20-hydroxyvitamin (20(OH)D₃) and classical 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) secosteroids inhibited melanoma cell proliferation. Active forms of vitamin D were found to inhibit NF-κB activity in nonpigmented cells, while having no effect on pigmented cells. Treatment of nonpigmented cells with vitamin D3 derivatives inhibited NF-κB DNA binding and NF-κB-dependent reporter assays, as well as inhibited the nuclear translocation of the p65 NF-κB subunit and its accumulation in the cytoplasm. Moreover, analysis of biopsies of melanoma patients showed that nonpigmented and slightly pigmented melanomas displayed higher nuclear NF-κB p65 expression than highly pigmented melanomas.

Conclusion:

Classical 1,25(OH)₂D₃ and novel 20(OH)D₃ hydroxyderivatives of vitamin D3 can target NF-κB and regulate melanoma progression in nonpigmented melanoma cells. Melanin pigmentation is associated with the resistance of melanomas to 20(OH)D₃ and 1,25(OH)₂D₃ treatment.

Fuzzy CMAC With incremental Bayesian Ying-Yang learning and dynamic rule construction

Inspired by the philosophy of ancient Chinese Taoism, Xu's Bayesian ying-yang (BYY) learning technique performs clustering by harmonizing the training data (yang) with the solution (ying). In our previous work, the BYY learning technique was applied to a fuzzy cerebellar model articulation controller (FCMAC) to find the optimal fuzzy sets; however, this is not suitable for time series data analysis. To address this problem, we propose an incremental BYY learning technique in this paper, with the idea of sliding window and rule structure dynamic algorithms. Three contributions are made as a result of this research. First, an online expectation-maximization algorithm incorporated with the sliding window is proposed for the fuzzification phase. Second, the memory requirement is greatly reduced since the entire data set no longer needs to be obtained during the prediction process. Third, the rule structure dynamic algorithm with dynamically initializing, recruiting, and pruning rules relieves the "curse of dimensionality" problem that is inherent in the FCMAC. Because of these features, the experimental results of the benchmark data sets of currency exchange rates and Mackey-Glass show that the proposed model is more suitable for real-time streaming data analysis.

Protein-functionalized hairy diamond nanoparticles

Diazonium salt chemistry and atom transfer radical polymerization (ATRP) were combined in view of preparing new bioactive hairy diamond nanoparticles containing, or potentially containing, nitrogen-vacancy (NV) fluorescent centers (fluorescent nanodiamonds, or fNDs). fNDs were modified by ATRP initiators using the electroless reduction of the diazonium salt BF(4)(-),(+)N(2)-C(6)H(4)-CH(CH(3))-Br. The strongly bound aryl groups -C(6)H(4)-CH(CH(3))-Br efficiently initiated the ATRP of tert-butyl methacrylate (tBMA) at the surface of the nanodiamonds, which resulted in obtaining ND-PtBMA hybrids. The grafted chain thickness, estimated from X-ray photoelectron spectroscopy (XPS), was found to increase linearly with respect to time before reaching a plateau value of ca. 2 nm. These nanoobjects were further hydrolyzed into ND-PMAA (where PMAA is the poly(methacrylic acid) graft) and further decorated by bovine serum albumin through the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling procedure.

Two-stage multi-class support vector machines to protein secondary structure prediction

Bioinformatics techniques to protein secondary structure (PSS) prediction are mostly single-stage approaches in the sense that they predict secondary structures of proteins by taking into account only the contextual information in amino acid sequences. In this paper, we propose two-stage Multi-class Support Vector Machine (MSVM) approach where a MSVM predictor is introduced to the output of the first stage MSVM to capture the sequential relationship among secondary structure elements for the prediction. By using position specific scoring matrices, generated by PSI-BLAST, the two-stage MSVM approach achieves Q3 accuracies of 78.0% and 76.3% on the RS126 dataset of 126 nonhomologous globular proteins and the CB396 dataset of 396 nonhomologous proteins, respectively, which are better than the highest scores published on both datasets to date.

Extremely low vertical-emittance beam in the accelerator test facility at KEK

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.

exo1-Dependent mutator mutations: model system for studying functional interactions in mismatch repair

EXO1 interacts with MSH2 and MLH1 and has been proposed to be a redundant exonuclease that functions in mismatch repair (MMR). To better understand the role of EXO1 in mismatch repair, a genetic screen was performed to identify mutations that increase the mutation rates caused by weak mutator mutations such as exo1Delta and pms1-A130V mutations. In a screen starting with an exo1 mutation, exo1-dependent mutator mutations were obtained in MLH1, PMS1, MSH2, MSH3, POL30 (PCNA), POL32, and RNR1, whereas starting with the weak pms1 allele pms1-A130V, pms1-dependent mutator mutations were identified in MLH1, MSH2, MSH3, MSH6, and EXO1. These mutations only cause weak MMR defects as single mutants but cause strong MMR defects when combined with each other. Most of the mutations obtained caused amino acid substitutions in MLH1 or PMS1, and these clustered in either the ATP-binding region or the MLH1-PMS1 interaction regions of these proteins. The mutations showed two other types of interactions: specific pairs of mutations showed unlinked noncomplementation in diploid strains, and the defect caused by pairs of mutations could be suppressed by high-copy-number expression of a third gene, an effect that showed allele and overexpressed gene specificity. These results support a model in which EXO1 plays a structural role in MMR and stabilizes multiprotein complexes containing a number of MMR proteins. A similar role is proposed for PCNA based on the data presented.

An improved GC/MS-based procedure for the quantitation of the isoprostane 15-F2t-IsoP in rat plasma

This article describes a procedure for the quantitation of the isoprostane 15-F2t-IsoP (9a,11a,15S-trihydroxy-(8b)-prosta-5Z,13E-dien-1-oic acid [CAS#27415-26-5] formerly known as 8-epi-PGF2a or 8-iso-PGF2a, and also as iPF2a-III). We have combined features from several earlier methods for 15-F2t-IsoP and prostaglandins, and identified and modified those steps that may lead to poor recoveries. The resulting protocol is precise and reliable, and was validated by a blind time-course study of plasma levels in rats treated with 120 and 1200 mg CCl4/kg body weight. Plasma levels of 15-F2t-IsoP, as measured according to the procedure described above, are good indicators of acute oxidative stress as induced by CCl4. The precision of the measurements allows detection of elevated plasma 15-F2t-IsoP levels as long as 16 h after an acute exposure of 120 mg CCl4/kg body weight, and 2 h after an exposure of 1 mg CCl4/kg body weight. The results of this low-dose, pilot study suggest that this method has sufficient analytical precision to allow the detection of the small changes in plasma isoprostane levels, which result from chronic and/or lower-level exposures to agents causing oxidative stress.

Myeloperoxidase and protein oxidation in cystic fibrosis

Cystic fibrosis (CF) is associated with chronic pulmonary inflammation and progressive lung dysfunction, possibly associated with the formation of neutrophil myeloperoxidase (MPO)-derived oxidants. Expectorated sputum specimens from adult CF patients were analyzed for MPO characteristic protein modifications and found to contain large amounts of active MPO as well as high levels of protein-associated 3-chlorotyrosine and 3,3'-dityrosine, products that result from MPO activity, compared with expectorated sputum from non-CF subjects. Sputum levels of nitrite (NO(2)(-)) and nitrate (NO(3)(-)), indicating local production of nitric oxide (NO. ), were not elevated but in fact were slightly reduced in CF. However, there was a slight increase in protein-associated 3-nitrotyrosine in CF sputum compared with controls, reflecting the formation of reactive nitrogen intermediates, possibly through MPO-catalyzed oxidation of NO(2)(-). CF sputum MPO was found to contribute to oxidant-mediated cytotoxicity toward cultured tracheobronchial epithelial cells; however, peroxidase-dependent protein oxidation occurred primarily within sputum proteins, suggesting scavenging of MPO-derived oxidants by CF mucus and perhaps formation of secondary cytotoxic products within CF sputum. Our findings demonstrate the formation of MPO-derived oxidizing and possibly nitrating species within the respiratory tract of subjects with CF, which collectively may contribute to bronchial injury and respiratory failure in CF.

Is the intention to quit smoking influenced by other heart-healthy lifestyle habits in 30- to 60-year-old men?

The aim of this study was to analyze whether the intention to quit smoking was associated with other lifestyle habits healthy for the heart, namely a low-fat diet and regular exercise, using variables suggested by the theory of planned behavior. Self-administered postal questionnaires were sent to 3,200 men 30 to 60 years of age residing in Laval, Quebec. With a response rate of 70.9%, 671 respondents (29.6%) were smokers. A significant proportion (43%) had all three risk behaviors--smoking, a high-fat diet, and sedentariness, and 42% had two--smoking and one of the other behaviors. The remaining had a single risk behavior, namely smoking. Regression analysis suggested that a healthy diet and exercise had no significant influence on the intention to quit smoking. However, men who had a stronger intention to quit smoking than others had a more favorable attitude toward the behavior, a stronger perception of approval in achieving it on the part of important referents, stronger perceived behavioral control, and were among those who smoked fewer cigarettes per day, but had made more attempts to quit. These results can assist in designing better heart-health intervention programs for this high-risk population.

Regular exercise in 30- to 60-year-old men: combining the stages-of-change model and the theory of planned behavior to identify determinants for targeting heart health interventions

The theory of planned behavior and the stages-of-change model were used to gain a clearer understanding of the factors associated with regular exercise in order to plan more effective programs in heart disease prevention. The study was conducted using a self-administered postal questionnaire sent to a sample of 2,269 men 30 to 60 years of age. Nearly a quarter (23.3%) of respondents were physically inactive, of whom 10.5% were in the precontemplation and 12.8% in the contemplation stages; 42.1% exercised less than twice a week, of whom 22.4% were in the preparation I and 19.7% in the preparation II stages. Only 34.6% were in the action stage, exercising regularly for at least 20 minutes twice a week or more with the intention of continuing to do so. Logistic regression indicated that the variables derived from the theory of planned behavior, namely attitude, subjective norm and perceived behavioral control, were differently associated with the stages of behavior. Perceived behavioral control was strongly significant in all stages. Attitude was related with stages in which individuals have intention of exercising (contemplation and preparation II). In contrast, subjective norm seemed to be associated with stages in which individuals have no intention of doing so (precontemplation and preparation I). By identifying the specific needs of sub-groups, the results can help define programs most likely to accelerate men to the stage of regular exercise, part of an effective strategy for heart health promotion in this high-risk population.

Diet and exercise profiles of 30- to 60-year-old male smokers: implications for community heart health programs

The aim of this study was to estimate the prevalence of diet and exercise behaviors in middle-aged male smokers and identify their determinants of behaviors, with the ultimate goal of designing more effective interventions in a community heart health program. Self-administered, postal questionnaires produced a sample of n = 671 male smokers, 30 to 60 years of age residing in Laval, Quebec's second most populous city. Variables for the study were derived from the theory of planned behavior. Correspondence analysis explained 65% of the variance, classifying smokers into five groups based on diet and exercise behavior. Group 1, smokers with diet and exercise behaviors deemed inadequate for heart health, comprised 43% of the total. Groups 2 and 3, smokers with a diet deemed inadequate or needing improvement respectively, and Group 4, smokers with inadequate exercise, comprised 42% of the total. Group 5, smokers with neither of the other high-risk behaviors, comprised 15% of the total. Four significant variables contrasted Groups 1 to 4 with group 5: age, number of cigarettes smoked daily, and perceived behavioral control (PBC) in both diet and exercise. However, coefficients for age and smoking were weak for all groups. Coefficients for PBC in diet were high and negative only for smokers with an inadequate one. For PBC in exercise, they were high and negative only for smokers who exercised inadequately. Intervention groups based on specific deficiencies in diet and exercise behaviors were then identified. Therefore, the results suggest that smoking cessation programs may be made more effective by targeting specific sub-groups and by providing resources and opportunities to counteract the lack of perceived behavioral control in middle-aged male smokers vis-a-vis diet and exercise.

Determinants of intention to adopt a low-fat diet in men 30 to 60 years old: implications for heart health promotion

PURPOSE

The purpose of the study was to identify the determinants of intention to have a low-fat diet in 30- to 60-year-old men.

DESIGN

The survey design was cross-sectional and consisted of a self-administered questionnaire. The dependent variable was the intention to have a low-fat diet within the next 4 months, and the independent variables were those suggested by the theory of planned behavior.

SETTING

The study population was drawn from three districts representing a modal sample of Laval, the second most populous city (N = 314,398) in the province of Quebec.

SUBJECTS

The sample comprised 3200 people. Of the 3200 questionnaires sent out, 2583 were received and 2269 were eligible (i.e., were answered by 30- to 60-year-old men), giving a response rate of 70.9%. Of the 2269 questionnaires, 430 were incomplete, resulted in 1839 being usable for analysis.

MEASURES

Multiple regression analysis was conducted to determine the influence of the independent variables on the dependent variable, the intention to have a low-fat diet. The independent variables were (1) direct and indirect determinants of intention as suggested in the theory of planned behavior and (2) sociodemographic and concomitant variables and their interactions. Discriminant analysis was used on the significant variables obtained in the regression to establish the cognitive profile of respondents' intention, strong or weak.

RESULTS

In the final model, five variables 51% of the total variance. Respondents who had a stronger intention perceived that their important referents would approve them having a low-fat diet. They scored higher in seeing the advantages of adopting the target behavior and had a more positive attitude toward the behavior. They also perceived themselves as having control over the target behavior, and scored higher in terms of recognizing the perceived power of this control factor.

CONCLUSIONS

The results suggests that the theory of planned behavior can be an effective tool in the planning of heart health promotion. They indicate that low-fat diet programs for men should target the work site and peer-group organizations, and place emphasis on adapting usual recipes. Though accenting the health and nutritional benefits of a low-fat diet, messages should appeal to emotion as well as reason.

Factors influencing the intention to use condoms in Quebec sexually-inactive male adolescents

PURPOSE

The purpose of this study was to determine whether attitudes and other variables would be associated with intention to use condoms in sexually-inactive male adolescents.

METHODS

The survey was conducted from April to June 1989 on a sample of 879 sexually-inactive boys aged 12-19 years registered in secondary schools in Laval, Quebec.

RESULTS

The major findings of the study were that: (1) information on condoms provided by peers was significantly associated with the intention to use condoms; (2) information provided by schools, while not significant in the final model, was positively associated with younger adolescents' intention to use condoms; and (3) sexually-inactive male adolescents in a less committed couple relationship had a greater intention to use condoms.

CONCLUSIONS

The results of this study highlight the importance of peer instructors as a source of information on condoms, as well as that of teachers and health professionals from the school environment. Other channels of communication, however, need to be developed particularly for older sexually-inactive adolescents who may be impervious to this latter source. The findings also underline the necessity to make sexually-inactive adolescents in stable couple relationships more aware of their potential vulnerability to STDs and AIDS should they commence sexual relations.

Behavioral diagnosis of 30 to 60 year-old men in the Fabreville Heart Health Program

To develop effective interventions in the Fabreville Heart Health Program, a behavioral diagnosis was conducted on a sample of 1,600 men 30 to 60 years of age residing in the Fabreville district of Laval, Quebec's second most populous city. The response rate of the self-administered postal questionnaire was 73.5%. The results indicate that dietary fat consumption, smoking and a sedentary lifestyle were more prevalent among the younger respondents, particularly those less-educated. The results underline the importance of segmenting the target population so that heart health interventions can respond to the specific needs of each sub-population. Furthermore, the data seem to suggest the need to adapt educational messages to the target lifestyle habits. The results showed that in terms of diet, consumption of meat and dairy products contributed the most to fat intake. Of the 30% who were smokers, a large proportion would be reluctant to stop the habit; 20% smoked 26 cigarettes or more a day, and more than half had already tried once or more to stop. Although 60% of respondents indicated they engaged in physical activity, only 37.0% did it regularly. These results demonstrate the need to clearly target specific behaviours and subgroups in our promotion messages for a healthy heart.

Influence of attitudes on the intention to use condoms in Quebec sexually active male adolescents

PURPOSE

The purpose of this study was to determine the influence of attitudes and other variables on the intention to use condoms in sexually active male adolescents.

METHODS

The survey was conducted from April to June 1989 on a sample of 433 sexually active boys aged 12-19 years registered in secondary schools in Laval, Quebec.

RESULTS

Information on condoms provided by parents, peers, school, or media had no positive effect on male adolescents' intention to use condoms. Having a favorable attitude towards contraceptive responsibility, however, was significantly associated with the outcome variable. Endorsement of this responsibility seemed short-lived being replaced by the birth control pill in older adolescents. The study also found that in younger adolescents, intention to use condoms was significantly associated with supportive parental attitudes.

CONCLUSIONS

The results of this study highlight the importance of developing strategies to encourage sexually active male adolescents to assume greater responsibility for using condoms, and suggest that in order for programs to be effective, STD and acquired immunodeficiency syndrome prevention should be done at younger ages while encouraging parents to take a greater role in sex education.