Development of a new biochemical test to diagnose and monitor neuroblastoma in Vietnam: Homovanillic and vanillylmandelic acid by gas chromatography-mass spectrometry

Objectives<br> The aim of this study was to develop an accurate robust testing method to simultaneously measure urine levels of HVA and VMA using gas chromatography mass spectrometry (GCMS) and to establish age-specific reference intervals of HVA and VMA in random urines for Vietnamese children.<p></p>Design and methods<br> The assay for urinary HVA and VMA was developed based on a classical urinary organic acid profiling method. Briefly, this incorporated 3-phenyl butyric acid as the internal standard and liquid–liquid extraction with ethyl acetate followed by derivatization with BSTFA. The Agilent 7890A GC and 5975C Mass Selective Detector in single ion monitoring mode was used for analysis.<p></p> Reference intervals were developed from random urine samples collected from 634 disease free Vietnamese children and compared to 50 known neuroblastoma patient samples. Results were reported relative to creatinine concentration. Age related 95% reference intervals for urinary HVA and VMA were estimated from sample quantiles. The analytes (expressed as analyte/creatinine ratios) diagnostic values were determined by calculating the related sensitivity, specificity and likelihood ratios.<p></p> Results<br> HVA and VMA were linear to at least 193 and 221 μmol/L, respectively. The limit of quantitation for both analytes was 0.9 μmol/L. Using the bi-level control (n = 15), the within-batch coefficients of variations (CVs) were less than 3% for both analytes across the assay range. The between-batch CVs (n = 20 over three months), were 3.6% at 11 μmol/L and 2.1% at 88 μmol/L for HVA, 6.6% at 18.2 μmol/L and 2.6% at 90.6 μmol/L for VMA.<p></p> Vietnamese age related reference intervals were established for urinary HVA and VMA per creatinine. HVA for children < 6 months (n = 91) was 5.3–37.0 μmol/mmol; 6 months to < 1 year (n = 141) was 2.7–27.7 μmol/mmol; 1 to 5 years (n = 139) was 3.4–17.9 μmol/mmol; 6 to 10 years (n = 136) was 2.7–8.8 μmol/mmol; and 11 to 15 years (n = 127) was 1.1–9.4 μmol/mmol. VMA for children < 6 months was 1.8–12.2 μmol/mmol; 6 months to < 1 year was 1.5–9.3 μmol/mmol; 1 to 5 years was 1.9–7.8 μmol/mmol; 6 to 10 years was 1.6–5.1 μmol/mmol; and 11 to 15 years was < 0.9–6.3 μmol/mmol.<p></p> Conclusions<br> A robust testing method for simultaneous quantitation of urinary HVA and VMA by GCMS was developed. This method is accurate, precise and fit for its clinical purpose and suitable for developing countries. Age-related reference intervals of urinary HVA and VMA were established for Vietnamese children and the intervals declined progressively with increasing age for each analyte

Prevalence of zoonotic trematodes in fish from a Vietnamese fish-farming community

The prevalence of fish-borne zoonotic trematode (FZT) metacercariae was investigated in fish farmed by rural households in Nghe An Province, located in northern Vietnam. In total, 716 fish, including tilapia (Oreochromis niloticus) and 6 carp species, i.e., grass carp (Ctenopharyngodon idellus), bighead carp (Aristichthys nobilis), mrigal (Cirrhinus mrigala), common carp (Cyprinus carpio), silver carp (Hypophthalmychthys molitrix), and roha (Labeo rohita), collected from 53 fish farms were examined. The overall prevalence of FZT metacercariae was 44.6%, ranging from 12.5% to 61.0% in fish species collected from grow-out ponds, which are the production system for growing fish from fingerling size to market size. The overall prevalence was 43.6% in fingerlings cultured in nurseries, ranging from 7.4% to 62.8% for different fish species. The FZT species recovered were heterophyids and echinostomatids and included Haplorchis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus, Stellantchasmus falcatus, and Echinochasmus japonicus, all of which are intestinal flukes in humans, other mammals, and birds. This is the first report of H. yokogawai and E. japonicus in fish in Vietnam, and the first record for S. falcatus in northern Vietnam. Although a previous cross-sectional survey of the people living in these fish farm households revealed a very low prevalence of FZTs (<1%), our results demonstrate that intestinal flukes are common in farmed fish in this area, suggesting that reservoir hosts such as dogs, cats, and pigs are more important in sustaining the life cycles of these flukes in fish farms than human hosts. This has implications for the effectiveness of control programs focused mainly on treatment of humans

Dynamic control of proinflammatory cytokines Il-1β and Tnf-α by macrophages in zebrafish spinal cord regeneration

Spinal cord injury leads to a massive response of innate immune cells in non-regenerating mammals, but also in successfully regenerating zebrafish. However, the role of the immune response in successful regeneration is poorly defined. Here we show that inhibiting inflammation reduces and promoting it accelerates axonal regeneration in spinal-lesioned zebrafish larvae. Mutant analyses show that peripheral macrophages, but not neutrophils or microglia, are necessary for repair. Macrophage-less irf8 mutants show prolonged inflammation with elevated levels of Tnf-α and Il-1β. Inhibiting Tnf-α does not rescue axonal growth in irf8 mutants, but impairs it in wildtype animals, indicating a pro-regenerative role of Tnf-α. In contrast, decreasing Il-1β levels or number of Il-1β+ neutrophils rescue functional regeneration in irf8 mutants. However, during early regeneration, interference with Il-1β function impairs regeneration in irf8 and wildtype animals. Hence, inflammation is dynamically controlled by macrophages to promote functional spinal cord regeneration in zebrafish

Nanoscale Confinement and Fluorescence Effects of Bacterial Light Harvesting Complex LH2 in Mesoporous Silicas

Many key chemical and biochemical reactions, particularly in living cells, take place in confined space at the mesoscopic scale. Toward understanding of physicochemical nature of biomacromolecules confined in nanoscale space, in this work we have elucidated fluorescence effects of a light harvesting complex LH2 in nanoscale chemical environments. Mesoporous silicas (SBA-15 family) with different shapes and pore sizes were synthesized and used to create nanoscale biomimetic environments for molecular confinement of LH2. A combination of UV-vis absorption, wide-field fluorescence microscopy, and in situ ellipsometry supports that the LH2 complexes are located inside the silica nanopores. Systematic fluorescence effects were observed and depend on degree of space confinement. In particular, the temperature dependence of the steady-state fluorescence spectra was analyzed in detail using condensed matter band shape theories. Systematic electronic-vibrational coupling differences in the LH2 transitions between the free and confined states are found, most likely responsible for the fluorescence effects experimentally observed

Inhibition of Renin-Angiotensin System Reverses Endothelial Dysfunction and Oxidative Stress in Estrogen Deficient Rats

BACKGROUND: Estrogen deficiency increases the cardiovascular risks in postmenopausal women. Inhibition of the renin-angiotensin system (RAS) and associated oxidative stress confers a cardiovascular protection, but the role of RAS in estrogen deficiency-related vascular dysfunction is unclear. The present study investigates whether the up-regulation of RAS and associated oxidative stress contributes to the development of endothelial dysfunction during estrogen deficiency in ovariectomized (OVX) rats. METHODOLOGY/PRINCIPAL FINDINGS: Adult female rats were ovariectomized with and without chronic treatment with valsartan and enalapril. Isometric force measurement was performed in isolated aortae. The expression of RAS components was determined by immunohistochemistry and Western blotting method while ROS accumulation in the vascular wall was evaluated by dihydroethidium fluorescence. Ovariectomy increased the expression of angiotensin-converting enzyme (ACE), angiotensin II type 1 receptor (AT(1)R), NAD(P)H oxidase, and nitrotyrosine in the rat aorta. An over-production of angiotensin II and ROS was accompanied by decreased phosphorylation of eNOS at Ser(1177) in OVX rat aortae. These pathophysiological changes were closely coupled with increased oxidative stress and decreased nitric oxide bioavailability, culminating in markedly impaired endothelium-dependent relaxations. Furthermore, endothelial dysfunction and increased oxidative stress in aortae of OVX rats were inhibited or reversed by chronic RAS inhibition with enalapril or valsartan. CONCLUSIONS/SIGNIFICANCE: The novel findings highlight a significant therapeutic benefit of RAS blockade in the treatment of endothelial dysfunction-related vascular complications in postmenopausal states

The baseline characteristics and interim analyses of the high-risk sentinel cohort of the Vietnam Initiative on Zoonotic InfectiONS (VIZIONS)

The Vietnam Initiative for Zoonotic Infections (VIZIONS) includes community-based 'high-risk sentinel cohort' (HRSC) studies investigating individuals at risk of zoonotic infection due to occupational or residential exposure to animals. A total of 852 HRSC members were recruited between March 2013 and August 2014 from three provinces (Ha Noi, Dak Lak, and Dong Thap). The most numerous group (72.8%) corresponded to individuals living on farms, followed by slaughterers (16.3%) and animal health workers (8.5%). Nasal/pharyngeal and rectal swabs were collected from HRSC members at recruitment and after notifying illness. Exposure to exotic animals (including wild pigs, porcupine, monkey, civet, bamboo rat and bat) was highest for the Dak Lak cohort (53.7%), followed by Ha Noi (13.7%) and Dong Thap (4.0%). A total of 26.8% of individuals reported consumption of raw blood over the previous year; 33.6% slaughterers reported no use of protective equipment at work. Over 686 person-years of observation, 213 episodes of suspect infectious disease were notified, equivalent of 0.35 reports per person-year. Responsive samples were collected from animals in the farm cohort. There was noticeable time and space clustering of disease episodes suggesting that the VIZIONS set up is also suitable for the formal epidemiological investigation of disease outbreaks

Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

Background Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout. Methods The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function. Findings Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function. Interpretation Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI

Cost effectiveness of potential ART adherence monitoring interventions in sub-saharan Africa

Background Interventions based around objective measurement of adherence to antiretroviral drugs for HIV have potential to improve adherence and to enable differentiation of care such that clinical visits are reduced in those with high adherence. It would be useful to understand the approximate upper limit of cost that could be considered for such interventions of a given effectiveness in order to be cost effective. Such information can guide whether to implement an intervention in the light of a trial showing a certain effectiveness and cost. Methods An individual-based model, calibrated to Zimbabwe, which incorporates effects of adherence and resistance to antiretroviral therapy, was used to model the potential impact of adherence monitoring-based interventions on viral suppression, death rates, disability adjusted life years and costs. Potential component effects of the intervention were: enhanced average adherence when on ART, reduced risk of ART discontinuation, and reduced risk of resistance acquisition. We considered a situation in which viral load monitoring is not available and one in which it is. In the former case, it was assumed that care would be differentiated based on the adherence level, with fewer clinic visits in those demonstrated to have high adherence. In the latter case, care was assumed to be primarily differentiated according to viral load level. The maximum intervention cost required to be cost effective was calculated based on a cost effectiveness threshold of $500 per DALY averted. Findings In the absence of viral load monitoring, an adherence monitoring-based intervention which results in a durable 6$50 per person-year on ART, mainly driven by the cost savings of differentiation of care. In the presence of viral load monitoring availability, an intervention with a similar effect on viral load suppression was cost-effective when costing $23-$32 per year, depending on whether the adherence intervention is used to reduce the level of need for viral load measurement. Conclusion The cost thresholds identified suggest that there is clear scope for adherence monitoringbased interventions to provide net population health gain, with potential cost-effective use in situations where viral load monitoring is or is not available. Our results guide the implementation of future adherence monitoring interventions found in randomized trials to have health benefit