A portable and low-cost centrifugal microfluidic platform for multiplexed colorimetric detection of protein biomarkers.

Cytokines play a very important role in our immune system by acting as mediators to put up a coordinated defense against foreign elements in our body. Elevated levels of cytokines in the body can signal to an ongoing response of the immune system to some abnormality. Thus, the quantification of a panel of cytokines can provide valuable information regarding the diagnosis of specific diseases and state of overall health of an individual. Conventional Enzyme Linked Immunosorbent Assay (ELISA) is the gold-standard for quantification of cytokines, however the need for trained personnel and expensive equipment limits its application to centralized laboratories only. In this context, there is a lack of simple, low-cost and portable devices which can allow for quantification of panels of cytokines at point-of-care and/or resource limited settings. Here, we report the development of a versatile, low-cost and portable bead-based centrifugal microfluidic platform allowing for multiplexed detection of cytokines with minimal hands-on time and an integrated colorimetric signal readout without the need for any external equipment. As a model, multiplexed colorimetric quantification of three target cytokines i.e., Tumor necrosis factor alpha (TNF-α), Interferon gamma (IFN-γ) and Interleukin-2 (IL-2) was achieved in less than 30 min with limits of detection in ng/mL range. The developed platform was further evaluated using spiked-in plasma samples to test for matrix interference. The ease of use, low-cost and portability of the developed platform highlight its potential to serve as a sample-to-answer solution for detection of cytokine panels in resource limited settings.

Percutaneous Coil Embolization of Coronary Artery Fistula Complicated by Refractory Ventricular Fibrillation and Cardiogenic Shock.

We present a case of a 56-year-old patient with a symptomatic right coronary artery to pulmonary artery fistula who underwent coil embolization. Post-procedure, the patient developed ventricular fibrillation that was refractory to antiarrhythmic medications and numerous attempts at defibrillation. (Level of Difficulty: Intermediate.).

Sample-to-answer COVID-19 nucleic acid testing using a low-cost centrifugal microfluidic platform with bead-based signal enhancement and smartphone read-out.

With its origin estimated around December 2019 in Wuhan, China, the ongoing SARS-CoV-2 pandemic is a major global health challenge. The demand for scalable, rapid and sensitive viral diagnostics is thus particularly pressing at present to help contain the rapid spread of infection and prevent overwhelming the capacity of health systems. While high-income countries have managed to rapidly expand diagnostic capacities, such is not the case in resource-limited settings of low- to medium-income countries. Aiming at developing cost-effective viral load detection systems for point-of-care COVID-19 diagnostics in resource-limited and resource-rich settings alike, we report the development of an integrated modular centrifugal microfluidic platform to perform loop-mediated isothermal amplification (LAMP) of viral RNA directly from heat-inactivated nasopharyngeal swab samples. The discs were pre-packed with dried n-benzyl-n-methylethanolamine modified agarose beads used to selectively remove primer dimers, inactivate the reaction post-amplification and allowing enhanced fluorescence detection via a smartphone camera. Sample-to-answer analysis within 1 hour from sample collection and a detection limit of approximately 100 RNA copies in 10 µL reaction volume were achieved. The platform was validated with a panel of 162 nasopharyngeal swab samples collected from patients with COVID-19 symptoms, providing a sensitivity of 96.6% (82.2-99.9%, 95% CI) for samples with Ct values below 26 and a specificity of 100% (90-100%, 95% CI), thus being fit-for-purpose to diagnose patients with a high risk of viral transmission. These results show significant promise towards bringing routine point-of-care COVID-19 diagnostics to resource-limited settings.

Flex Printed Circuit Board Implemented Graphene-Based DNA Sensor for Detection of SARS-CoV-2.

Since the COVID-19 outbreak was declared a pandemic by the World Health Organization (WHO) in March 2020, ongoing efforts have been made to develop sensitive diagnostic platforms. Detection of viral RNA provides the highest sensitivity and specificity for detection of early and asymptomatic infections. Thus, this work aimed at developing a label-free genosensor composed of graphene as a working electrode that could be embedded into a flex printed circuit board (FPCB) for the rapid, sensitive, amplification-free and label-free detection of SARS-CoV-2. To facilitate liquid handling and ease of use, the developed biosensor was embedded with a user-friendly reservoir chamber. As a proof-of-concept, detection of a synthetic DNA strand matching the sequence of ORF1ab was performed as a two-step strategy involving the immobilization of a biotinylated complementary sequence on a streptavidin-modified surface, followed by hybridization with the target sequence recorded by the differential pulse voltammetric (DPV) technique in the presence of a ferro/ferricyanide redox couple. The effective design of the sensing platform improved its selectivity and sensitivity and allowed DNA quantification ranging from 100 fg/mL to [Formula: see text]/mL. Combining the electrochemical technique with FPCB enabled rapid detection of the target sequence using a small volume of the sample (5-[Formula: see text]). We achieved a limit-of-detection of 100 fg/mL, whereas the predicted value was ~33 fg/mL, equivalent to approximately [Formula: see text] copies/mL and comparable to sensitivities provided by isothermal nucleic acid amplification tests. We believe that the developed approach proves the ability of an FPCB-implemented DNA sensor to act as a potentially simpler and more affordable diagnostic assay for viral infections in Point-Of-Care (POC) applications.

Associations between urinary heavy metal concentrations and blood pressure in residents of Asian countries

BACKGROUND@#Previous studies have suggested that exposures to heavy metals (arsenic, cadmium, lead, and selenium) may be associated with differences in blood pressure. However, the findings of these studies have been inconsistent. This study was performed to examine the associations between urinary heavy metal concentrations and blood pressure among residents of four Asian countries (Bangladesh, Indonesia, Nepal, and Vietnam).@*METHODS@#This cross-sectional study examined 1899 adults in four Asian countries. Urinary concentrations of heavy metals were measured by inductively coupled plasma mass spectrometry. A questionnaire survey was administered regarding individual characteristics. Anthropometric measurements (height and weight) were performed. Systolic and diastolic blood pressures were measured after a short rest. Multiple linear regression models were applied to investigate associations between urinary heavy metal concentrations and blood pressure after adjustments for age, sex, and body mass index.@*RESULTS@#The geometric means of the urinary concentrations of arsenic, cadmium, lead, and selenium were 84.6, 0.885, 2.09, and 16.5 μg/g creatinine, respectively. The urinary arsenic concentrations were slightly higher than those typically reported in non-polluted populations, while urinary cadmium, lead, and selenium concentrations were equivalent or slightly lower. The urinary lead concentrations were positively associated with both systolic and diastolic blood pressure, but urinary selenium concentrations were negatively associated with them.@*CONCLUSIONS@#Variations in the urinary concentrations of lead and selenium were associated with blood pressure at low levels of exposure/intake.

Gestational Diabetes Among The Arsenic Exposed Women From Arsenic Contaminated Area Of Bangladesh

@#Exposure to groundwater arsenic contamination has been demonstrated to be associated with an increased risk of diabetes mellitus in Bangladesh. But, the association between arsenic exposure and Gestational Diabetes Mellitus (GDM) in Bangladesh remains to be reported. This cross-sectional study was carried out to assess the occurrence of GDM amongst pregnant women from the arsenic contaminated area. A total of 200 pregnant women who were aged 20 years and more, having gestational age more than 21 weeks, and had attended a district hospital for antenatal checkup were selected for the study. Of the total 200 participants, 15.5% were found to have GDM and it was significantly high (p=0.029) in women with higher gestational age. Regarding arsenic exposure, 39.5% of the participants were categorized as arsenic exposed and amongst them the proportion of GDM was found high (20.3%). Binary logistic regression analysis showed that the increase in gestational age and BMI, and a higher level of arsenic in urine of the total participants, had significantly (p<0.05) ability to predict the likelihood of having GDM (1.2, 1.1 and 9.2 times respectively). While logistic regression analysis among the arsenic exposed participants showed that higher level of BMI was 1.2 times and arsenic in urine was 9.4 times likely to predict the likelihood of having GDM. Thus, it was revealed that the increased concentration of arsenic in urine had the strongest ability to predict the likelihood of developing GDM among the pregnant women. The study concluded that the arsenic exposed pregnant women suffered more from GDM compared to the non-exposed pregnant woman.

Food Habits Among The Arsenic Exposed Population In The Rural Areas Of Nepal And Bangladesh

Arsenicosis, the illness due to chronic arsenic toxicity is prevalent in both Nepal and Bangladesh. The occurrence of arsenicosis depends upon many factors including food and nutrition. The objective of this study was to find out any difference of food habits among the arsenic exposed households of both countries and the relationship with the occurrence of arsenicosis. This was a cross-sectional comparative study, conducted among the arsenic exposed rural households of Nawalparasi district in Nepal and Faridpur district in Bangladesh. A total of 190 and 200 female rural households from Nepal and Bangladesh were selected respectively as the respondents. The majority of the respondents of both countries were under the age of 40 years. The prevalence of arsenicosis was found significantly low (χ2 = 8.847; p=.002) among the Nepalese households (7.3%) than that of Bangladeshi households (11.0%). As a staple food, rice, vegetables and pulses were more common among the Nepalese households in comparison to that of Bangladesh (χ2=5.739; p=.017). In addition to staple food Nepalese households were found to take significantly more (p<.05) bread (74.7%), egg (73.2%), milk (68.9%) and fruits (58.4%). In contrast, Bangladeshi households took a little more meat (59.0%) and fish (73.5%). To get arsenic-safe water, 39.5% Bangladeshi households used a filter while a few Nepalese households (2.6%) used that. Nepalese households were found to take more protein and vitamins rich foods as staple food compared to that of Bangladeshi households, which might play a role in the low occurrence of arsenicosis amongst them.

Food Habits Among The Arsenic Exposed Population In The Rural Areas Of Nepal And Bangladesh

@#Arsenicosis, the illness due to chronic arsenic toxicity is prevalent in both Nepal and Bangladesh. The occurrence of arsenicosis depends upon many factors including food and nutrition. The objective of this study was to find out any difference of food habits among the arsenic exposed households of both countries and the relationship with the occurrence of arsenicosis. This was a cross-sectional comparative study, conducted among the arsenic exposed rural households of Nawalparasi district in Nepal and Faridpur district in Bangladesh. A total of 190 and 200 female rural households from Nepal and Bangladesh were selected respectively as the respondents. The majority of the respondents of both countries were under the age of 40 years. The prevalence of arsenicosis was found significantly low (χ2 = 8.847; p=.002) among the Nepalese households (7.3%) than that of Bangladeshi households (11.0%). As a staple food, rice, vegetables and pulses were more common among the Nepalese households in comparison to that of Bangladesh (χ2=5.739; p=.017). In addition to staple food Nepalese households were found to take significantly more (p<.05) bread (74.7%), egg (73.2%), milk (68.9%) and fruits (58.4%). In contrast, Bangladeshi households took a little more meat (59.0%) and fish (73.5%). To get arsenic-safe water, 39.5% Bangladeshi households used a filter while a few Nepalese households (2.6%) used that. Nepalese households were found to take more protein and vitamins rich foods as staple food compared to that of Bangladeshi households, which might play a role in the low occurrence of arsenicosis amongst them.

A systematic review and cost-effectiveness analysis of tonometer disinfection methods.

OBJECTIVE: The Goldmann applanation tonometer presents the problem of being one of the most widely used pieces of equipment in the ophthalmic clinic and a known risk factor for the transmission of epidemic keratoconjunctivitis (EKC). The purpose of this review is to assess the effectiveness of 3 methods of disinfection: alcohol swabs, immersion in peroxide, and the use of disposable prisms. An economic evaluation is undertaken to assess the cost-effectiveness of the 3 alternatives. In doing so, we contribute an evidence-based overview of the issue at an opportune time, because several jurisdictions are developing protocols regarding tonometer tip disinfection. DESIGN: Systematic review and cost-effectiveness analysis. METHODS: A comprehensive literature review was undertaken with a librarian, comprising searches of 6 electronic databases and hand searches of the grey literature. A 3-level screening process was undertaken by 2 reviewers according to prespecified inclusion and exclusion criteria. Values from included papers were used to inform a cost-effectiveness analysis undertaken using a decision tree model implemented in TreeAge. The analysis was undertaken from the hospital perspective and included all equipment and labour costs. RESULTS: Synthesis of in vitro data indicates that all 3 methods are plausible methods of disinfection with a 64% reduction in log growth of EKC when peroxide is used compared with alcohol swabs. The incremental cost-effective ratios from the cost-effectiveness analysis were $12,000/case averted using peroxide and $61,000/case averted with Tonosafe as compared with alcohol. CONCLUSIONS: Assuming clinical infection rates match in vitro disinfection data, the cost of bleach is high and the cost of Tonosafe is unacceptably high to reduce 1 potential case of adenoviral keratoconjunctivitis.

Prevalence and Determinants of Smoking Behaviour among the Secondary School Teachers in Bangladesh

Despite country’s tobacco control law, cigarette smoking by the young people and the magnitude of nicotine dependence among the school personnel is alarming. To determine the prevalence of smoking and to examine the determinants of smoking behaviour among the secondary school teachers in Bangladesh. A two-stage cluster sampling was used with a selection of schools on Probability Proportional to Enrolment (PPE) size followed by stratified random sampling of government and private schools and then all the teachers present on the day of the survey were selected for the study. The 66-item questionnaire included smoking behaviour, knowledge, attitude, second-hand smoking, tobacco free school policy, cessation, media advertisement and curriculum related topics. Seven additional questions were included to assess the socio-demographic characteristics of the teachers. Data analysis was performed using SPSS 17 software. A total of 60 schools were selected with school response rate of 98.3%. An anonymous self-administered questionnaire was filled in by all teachers present at the day of the survey. The sample consisted of 559 teachers with response rate of 99.5%. The prevalence of smoking was 17% (95% CI: 14%, 20.4). About half of the teachers (48.4%) smoke daily followed by 25.3% smoke 1-2 days in last 30 days. The mean duration smoking of was 13.7(95% CI: 11.6, 15.9) years. Logistic regression analysis revealed that male teachers smoke 37.46(95% CI: 5.078, 276.432) times higher than their female counterparts. The graduate teachers were 2.179(95% 1.209, 3.926) times more likely to be smoke than master’s degree holder teachers. Smoking by friends appeared to be the strongest predictor for teachers smoking behaviour (OR 4.789, 95% CI: 1.757, 13.050). However, no statistically significant association was found between type of school, second-hand smoking and curriculum related factors and smoking behaviour of the teachers (p>0.05). Prevalence of smoking among the teachers is high in Bangladesh. Effective smoking prevention program should take into account within the dominant of socio-environmental influence to reduce smoking behaviour. The school curriculum items had less impact in preventing smoking behaviour.