Development and Evaluation/Verification of a Fully Automated Test Platform for the Rapid Detection of Cyclospora cayetanensis in Produce Matrices.

Cyclosporiasis, caused by the coccidian parasite Cyclospora cayetanensis, has emerged as an increasing global public health concern, with the incidence of laboratory-confirmed domestically acquired cases in the US exceeding 10,000 since 2018. A recently published qPCR assay (Mit1C) based on a mitochondrial target gene showed high specificity and good sensitivity for the detection of C. cayetanensis in fresh produce. The present study shows the integration and verification of the same mitochondrial target into a fully automated and streamlined platform that performs DNA isolation, PCR, hybridization, results visualization, and reporting of results to simplify and reduce hands-on time for the detection of this parasite. By using the same primer sets for both the target of interest (i.e., Mit1C) and the internal assay control (IAC), we were able to rapidly migrate the previously developed Mit1C qPCR assay into the more streamlined and automated format Rheonix C. cayetanensisTM Assay. Once the best conditions for detection were optimized and the migration to the fully automated format was completed, we compared the performance of the automated platform against the original "bench top" Mit1C qPCR assay. The automated Rheonix C. cayetanensis Assay achieved equivalent performance characteristics as the original assay, including the same performance for both inclusion and exclusion panels, and it was able to detect as low as 5 C. cayetanensis oocysts in fresh produce while significantly reducing hands-on time. We expect that the streamlined assay can be used as a tool for outbreak and/or surveillance activities to detect the presence of C. cayetanensis in produce samples.

Clinical profile and early severity predictors of dengue fever: Current trends for the deadliest dengue infection in Bangladesh in 2022.

Objectives: In 2022, Bangladesh had the highest dengue-related fatality (281). This study evaluated clinical profiles to detect early changes to predict dengue fever severity. Methods: This prospective observational study was performed in four government hospitals from June to November 2022 in Dhaka. Febrile patients admitted within 4th day of illness were recruited if they had a confirmed dengue viral infection either by by positive dengue nonstructural protein antigen or anti-dengue immunoglobulin (Ig)M antibody. Results: We divided 308 patients with confirmed dengue into two groups: 232 (74.3%) in nonsevere dengue and 76 (24.7%) in severe dengue. Men were 205 (66.6%), and the most affected age group was 21-30 years (47.7%). Patients with severe dengue reported a higher number of nausea 80.3%, coughs 57.9%, abdominal pain 56.6%, persistent vomitting 53.9%, dyspnea 35.5%, diarrhea 28.9%, and skin rash at 27.6%. In addition, the disease's febrile phase (≤4 days) showed thrombocytopenia (odds ratio [OR] 6.409, 95% CI 2.855-14.386, p <0.001), hemoconcentration (OR 3.428, 95% CI 1.030-11.405, p 0.045), and hypotension (OR 5.896, 95% CI 1.203-28.897, p 0.029) were associated severe disease. Conclusions: Hypotension, thrombocytopenia, and hemoconcentration during the febrile phase might indicate progression towards severe disease.

A five-day course of ivermectin for the treatment of COVID-19 may reduce the duration of illness.

Ivermectin, a US Food and Drug Administration-approved anti-parasitic agent, was found to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in vitro. A randomized, double-blind, placebo-controlled trial was conducted to determine the rapidity of viral clearance and safety of ivermectin among adult SARS-CoV-2 patients. The trial included 72 hospitalized patients in Dhaka, Bangladesh, who were assigned to one of three groups: oral ivermectin alone (12 mg once daily for 5 days), oral ivermectin in combination with doxycycline (12 mg ivermectin single dose and 200 mg doxycycline on day 1, followed by 100 mg every 12 h for the next 4 days), and a placebo control group. Clinical symptoms of fever, cough, and sore throat were comparable among the three groups. Virological clearance was earlier in the 5-day ivermectin treatment arm when compared to the placebo group (9.7 days vs 12.7 days; p = 0.02), but this was not the case for the ivermectin + doxycycline arm (11.5 days; p = 0.27). There were no severe adverse drug events recorded in the study. A 5-day course of ivermectin was found to be safe and effective in treating adult patients with mild COVID-19. Larger trials will be needed to confirm these preliminary findings.

Convalescent plasma transfusion therapy in severe COVID-19 patients- a safety, efficacy and dose response study: A structured summary of a study protocol of a phase II randomized controlled trial.

OBJECTIVES: General: To assess the safety, efficacy and dose response of convalescent plasma (CP) transfusion in severe COVID-19 patients Specific: a. To identify the appropriate effective dose of CP therapy in severe patients b. To identify the efficacy of the therapy with their end point based on clinical improvement within seven days of treatment or until discharge whichever is later and in-hospital mortality c. To assess the clinical improvement after CP transfusion in severe COVID-19 patients d. To assess the laboratory improvement after CP transfusion in severe COVID-19 patients TRIAL DESIGN: This is a multicentre, multi-arm phase II Randomised Controlled Trial. PARTICIPANTS: Age and sex matched COVID-19 positive (by RT-PCR) severe cases will be enrolled in this trial. Severe case is defined by the World Health Organization (W.H.O) clinical case definition. The inclusion criteria are 1. Respiratory rate > 30 breaths/min; PLUS 2. Severe respiratory distress; or SpO2 ≤ 88% on room air or PaO2/FiO2≤ 300 mm of Hg, PLUS 3. Radiological (X-ray or CT scan) evidence of bilateral lung infiltrate, AND OR 4. Systolic BP < 90 mm of Hg or diastolic BP <60 mm of Hg. AND/OR 5. Criteria 1 to 4 AND or patient in ventilator support Patients' below18 years, pregnant and lactating women, previous history of allergic reaction to plasma, patients who have already received plasma from a different source will be excluded. Patients will be enrolled at Bangabandhu Sheikh Mujib Medical University (BSMMU) hospital, Dhaka medical college hospital (DMCH) and Mugda medical college hospital (MuMCH). Apheretic plasma will be collected at the transfusion medicine department of SHNIBPS hospital, ELISA antibody titre will be done at BSMMU and CMBT and neutralizing antibody titre will be checked in collaboration with the University of Oxford. Patients who have recovered from COVID-19 will be recruited as donors of CP. The recovery criteria are normality of body temperature for more than 3 days, resolution of respiratory symptoms, two consecutively negative results of sputum SARS-CoV-2 by RT-PCR assay (at least 24 hours apart) 22 to 35 days of post onset period, and neutralizing antibody titre ≥ 1:160. INTERVENTION AND COMPARATOR: This RCT consists of three arms, a. standard care, b. standard care and 200 ml CP and c. standard care and 400 ml CP. Patients will receive plasma as a single transfusion. Intervention arms will be compared to the standard care arm. MAIN OUTCOMES: The primary outcome will be time to clinical improvement within seven days of treatment or until discharge whichever is later and in-hospital mortality. The secondary outcome would be improvement of laboratory parameters after therapy (neutrophil, lymphocyte ratio, CRP, serum ferritin, SGPT, SGOT, serum creatinine and radiology), length of hospital stay, length of ICU stay, reduction in proportion of deaths, requirement of ventilator and duration of oxygen and ventilator support. RANDOMISATION: Randomization will be done by someone not associated with the care or assessment of the patients by means of a computer generated random number table using an allocation ratio of 1:1:1. BLINDING (MASKING): This is an open level study; neither the physician nor the patients will be blinded. However, the primary and secondary outcome (oxygen saturations, PaO2/FiO2, BP, day specific laboratory tests) will be recorded using an objective automated method; the study staff will not be able to influence the recording of these data. NUMBER TO BE RANDOMISED (SAMPLE SIZE): No similar study has been performed previously. Therefore no data are available that could be used to generate a sample size calculation. This phase II study is required to provide some initial data on efficacy and safety that will allow design of a larger study. The trial will recruit 60 participants (20 in each arm). TRIAL STATUS: Protocol version 1.4 dated May 5, 2020 and amended version 1.5, dated June 16, 2020. First case was recruited on May 27, 2020. By August 10, 2020, the trial had recruited one-third (21 out of 60) of the participants. The recruitment is expected to finish by October 31, 2020. TRIAL REGISTRATION: Clinicaltrials.gov ID: NCT04403477 . Registered 26 May, 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trial's website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this letter serves as a summary of the key elements of the full protocol.

Detection of Zika virus using reverse-transcription LAMP coupled with reverse dot blot analysis in saliva.

In recent years, there have been increasing numbers of infectious disease outbreaks that spread rapidly to population centers resulting from global travel, population vulnerabilities, environmental factors, and ecological disasters such as floods and earthquakes. Some examples of the recent outbreaks are the Ebola epidemic in West Africa, Middle East respiratory syndrome coronavirus (MERS-Co) in the Middle East, and the Zika outbreak through the Americas. We have created a generic protocol for detection of pathogen RNA and/or DNA using loop-mediated isothermal amplification (LAMP) and reverse dot-blot for detection (RDB) and processed automatically in a microfluidic device. In particular, we describe how a microfluidic assay to detect HIV viral RNA was converted to detect Zika virus (ZIKV) RNA. We first optimized the RT-LAMP assay to detect ZIKV RNA using a benchtop isothermal amplification device. Then we implemented the assay in a microfluidic device that will allow analyzing 24 samples simultaneously and automatically from sample introduction to detection by RDB technique. Preliminary data using saliva samples spiked with ZIKV showed that our diagnostic system detects ZIKV RNA in saliva. These results will be validated in further experiments with well-characterized ZIKV human specimens of saliva. The described strategy and methodology to convert the HIV diagnostic assay and platform to a ZIKV RNA detection assay provides a model that can be readily utilized for detection of the next emerging or re-emerging infectious disease.

Prevalence, treatment patterns, and risk factors of hypertension and pre-hypertension among Bangladeshi adults.

In Bangladesh, morbidity and mortality due to non-communicable diseases (NCDs) has increased over the last few decades. Hypertension is an important risk factor for NCDs, specifically cardiovascular disease. The objective of this study was to assess prevalence and risk factors for hypertension and pre-hypertension among adults in Bangladesh. Data for this analysis were collected during the national NCD Risk Factor Survey of Bangladesh conducted in 2010 from a representative sample of men and women, aged 25 years or above. The survey adopted a multistage, geographically clustered, probability-based sampling approach. WHO STEPS questionnaire was used to collect data on demographics, behavioral risk factors, and physical measurements. Overall, 20% of the study population were hypertensive at study measurement. The prevalence of hypertension increased with age and body mass index (BMI). Twelve percent of the population were previously diagnosed with hypertension. Among these individuals, nearly half were not taking any medications to control their hypertension. Additionally, the prevalence of pre-hypertension was 43%, with higher levels among males, older age groups, and those with higher education, higher wealth index and high BMI. Predictors of hypertension, included older age, high BMI, and diabetes comorbidity. Based on this study, we estimate that 1 out of 5 Bangladeshi adults have hypertension. The risk of hypertension increases with older age and high BMI. Additionally, prevalence of pre-hypertension is high in Bangladesh in both rural and urban areas. Findings from this study can be used to inform public health programming to control the spread of NCDs in Bangladesh.

A modifiable microarray-based universal sensor: providing sample-to-results automation.

A microfluidic system consisting of generic single use cartridges which interface with a workstation allows the automatic performance of all necessary sample preparation, PCR analysis and interpretation of multiplex PCR assays. The cartridges contain a DNA array with 20 different 16mer DNA "universal" probes immobilized at defined locations. PCR amplicons can be detected via hybridization of user-defined "reporter" probes that are complementary at their 3' termini to one or more of the universal probes and complementary to the target amplicons at their 5' termini. The system was able to detect single-plex and multiplex PCR amplicons from various infectious agents as well as wild type and mutant alleles of single nucleotide polymorphisms. The system's ease of use was further demonstrated by converting a published PCR assay for the detection of Mycobacterium genitalium in a fully automated manner. Excellent correlation between traditional manual methods and the automated analysis performed by the workstation suggests that the system can provide a means to easily design and implement a variety of customized PCR-based assays. The system will be useful to researchers or clinical investigators seeking to develop their own user defined assays. As the U.S. FDA continues to pursue regulatory oversight of LDTs, the system would also allow labs to continue to develop compliant assays.

A Rapid, Self-confirming Assay for HIV: Simultaneous Detection of Anti-HIV Antibodies and Viral RNA.

OBJECTIVE: We developed a microfluidic system to simultaneously detect host anti-HIV antibodies and viral RNA in the same specimen in order to satisfy two important diagnostic criteria, especially within resource-limited settings. First, the system can detect acute HIV infection and allow immediate confirmation of a seropositive screening result by detection of HIV RNA. It also addresses the well-known "seroconversion window" during early HIV infection when antibodies are not yet detectable and viral loads are at their highest. METHODS: We first developed and optimized two separate manual assays for the detection of host anti-HIV antibodies and viral RNA and then converted them to the microfluidic system. We optimized a commercially available serologic assay to run within the microfluidic device while we incorporated the isothermal LAMP assay to detect the presence of viral RNA. The microfluidic device and instrumentation were developed to simultaneously perform both assays without any user intervention. RESULTS: The finalized system consists of a disposable injection molded and film-laminated microfluidic CARD disposable device and a portable, software controlled instrument, which together can automatically perform all steps of both assays without any user intervention after the initial loading of samples and reagents. The microfluidic CARD cartridge has multiple microchannels, valves, pumps and reservoirs, which perform the immunoassay, isolates viral RNA for detection by magnetic bead based purification, and Reverse Transcriptase loop-mediated isothermal amplification (RT-LAMP). The microfluidic system was able to detect host anti-HIV antibodies and viral RNA in either a blood or saliva sample. CONCLUSION: The ability to detect antibodies and simultaneously confirm a seropositive HIV-RNA result provides healthcare workers with a complete and accurate appraisal of a patient's infection status in the earliest stages of the disease and represents an important tool for the "Test and Treat" and "Treatment as Prevention" approaches for controlling the HIV epidemic.

Determination of genotypes using a fully automated molecular detection system.

CONTEXT: Although the value of pharmacogenomics to improve patient outcomes has become increasingly clear, adoption in medical practice has been slow, which can be attributed to several factors, including complicated and expensive testing procedures and required equipment, lack of training by private practice physicians, and reluctance of both private and commercial payers to reimburse for such testing. OBJECTIVES: To evaluate a fully automated molecular detection system for human genotyping assays, starting with anticoagulated whole blood samples, and to perform all sample preparation, assay, and analysis steps automatically with actionable results reported by the system's software. DESIGN: The genotypes of 254 random individuals were determined by performing bidirectional DNA sequencing, and that information was used to statistically train the imaging software of the automated molecular detection system to distinguish the 3 possible genotypes (ie, homozygous wild type, heterozygous, and homozygous mutant) at each of 3 different loci (CYP2C9*2, CYP2C9*3, and VKORC1). RESULTS: The resulting software algorithm was able to correctly identify the genotypes of all 254 individuals (100%) evaluated without any further user analysis. CONCLUSIONS: The EncompassMDx workstation (Rheonix, Inc, Ithaca, New York) is a molecular detection system that can automatically determine the genotypes of individuals in an unattended manner. Considerably less technical expertise was required to achieve results identical to those obtained using more complex, time-consuming, and expensive bidirectional DNA sequencing. This optimized system may dramatically simplify and reduce the costs of pharmacogenomics testing, thus leading to more-widespread use.

Rheonix CARD(®) Technology: An Innovative and Fully Automated Molecular Diagnostic Device.

A versatile microfluidic platform for the evolving molecular diagnostics industry is described. It incorporates low cost Rheonix CARD(®) (Chemistry and Reagent Device) technology to analyze a variety of clinical specimens. A patented lamination process incorporates all pumps, valves, microchannels and reaction compartments into an inexpensive disposable plastic device. Once an untreated clinical specimen is introduced, all assay steps, including cell lysis, nucleic acid purification, multiplex PCR, and end-point analysis, are automatically performed. Three distinct CARD assays are described which utilize either a low density microarray for multiplex detection of amplicons or an integrated primer extension assay to detect single nucleotide polymorphisms of interest. The STI (Sexually Transmitted Infections) CARD(®) is able to simultaneously detect four sexually transmitted infectious agents (N. gonorrhoeae, C.trachomatis, T. pallidum and T. vaginalis). Human C33A cervical epithelial cells were spiked with different levels of genomic DNA from the four species of interest, singly or in combination, and applied to the CARD device. Using multiplex PCR amplification of the targets followed by microarray detection, the CARD device was able to correctly detect a minimum of 10 copies of each of the four pathogens. The HPV (Human Papillomavirus) CARD(®) was able to detect and distinguish 20 different clinically relevant HPV types using cloned HPV DNA. In addition, the HPV CARD could identify HPV types in vaginal specimens previously demonstrated to contain high or low risk HPV using a currently commercially available testing method. Finally, the detection of specific single nucleotide polymorphisms (SNP) associated with warfarin dosing sensitivity was achieved on the Warfarin Genotyping CARD(®) by analyzing human buccal swabs. Once multiplex PCR was completed, the SNPs were detected using a primer extension assay.

Inhibition of mammary carcinoma cell growth by RXR is mediated by the receptor's oligomeric switch.

Ligands that activate the nuclear receptor retinoid X receptor (RXR) display potent anticarcinogenic activities, but the mechanisms by which these compounds inhibit carcinoma cell growth are poorly understood. While RXR can regulate gene expression due to its intrinsic ligand-activated transcription function, this receptor can also regulate transcription by functioning as a ligand-controlled DNA architectural factor. It was thus reported that apo-RXR self-associates into tetramers and that each dimer within these tetramers can separately bind to an RXR response element. Hence, DNA binding by RXR tetramers may bring distant genomic regions into close physical proximity. As ligand binding induces the dissociation of RXR tetramers into dimers, it can alter gene expression by modulating the DNA architecture. Here, we show that inhibition of mammary carcinoma cell growth by RXR ligands stems from the ability of these compounds to regulate the oligomeric state of RXR and is independent of the direct intrinsic transcriptional activity of the receptor. The data suggest that compounds that trigger dissociation of RXR tetramers may comprise a novel class of anticarcinogenic agents.

Nuclear import of the retinoid X receptor, the vitamin D receptor, and their mutual heterodimer.

The nuclear receptor retinoid X receptor (RXR) can regulate transcription through homotetramers, homodimers, and heterodimers with other nuclear receptors such as the vitamin D receptor (VDR). The mechanisms that underlie the nuclear import of RXR, VDR, and RXR-VDR heterodimers were investigated. We show that RXR and VDR translocate into the nucleus by distinct pathways. RXR strongly bound to importinbeta and was predominantly nuclear in the absence of ligand. Importin binding and nuclear localization of RXR were modestly enhanced by its ligand, 9-cis-retinoic acid. On the other hand, VDR selectively associated with importinalpha. Importin association and correspondingly nuclear import of VDR were markedly augmented by 1,25(OH)2D3. RXR-VDR dimerization inhibited the ability of RXR to bind importinbeta and to mobilize into the nucleus using its own nuclear localization signal. In contrast, VDR recruited RXR-VDR heterodimers to importinalpha and mediated nuclear import of the heterodimers in response to 1,25(OH)2D3. Hence nuclear import of RXR-VDR heterodimers is mediated preferentially by VDR and is controlled by the VDR ligand. The observations reveal a novel mechanism by which an RXR heterodimerization partner dominates the activity of the heterodimers.

DNA-looping by RXR tetramers permits transcriptional regulation "at a distance".

RXR, a member of the superfamily of nuclear hormone receptors, regulates gene transcription in response to 9-cis-retinoic acid. We previously showed that, among nuclear receptors, RXR is unique in that it self-associates into homotetramers, and that these tetramers dissociate rapidly upon ligation. Here, we report that binding of RXR tetramers to DNA containing two RXR response elements results in a dramatic DNA-looping. RXR can thus juxtapose distant DNA sequences, enabling transcriptional regulation by far-upstream factors. We show that RXR functions as a DNA architectural factor and that, while this activity is regulated by 9-cis-retinoic acid, it is distinct from and independent of the receptor's intrinsic transcriptional activity. The data establish RXR as the first identified architectural factor whose activity is regulated by a small ligand, and demonstrate a novel mechanism of transcriptional regulation by retinoids.

Selective cooperation between fatty acid binding proteins and peroxisome proliferator-activated receptors in regulating transcription.

Lipophilic compounds such as retinoic acid and long-chain fatty acids regulate gene transcription by activating nuclear receptors such as retinoic acid receptors (RARs) and peroxisome proliferator-activated receptors (PPARs). These compounds also bind in cells to members of the family of intracellular lipid binding proteins, which includes cellular retinoic acid-binding proteins (CRABPs) and fatty acid binding proteins (FABPs). We previously reported that CRABP-II enhances the transcriptional activity of RAR by directly targeting retinoic acid to the receptor. Here, potential functional cooperation between FABPs and PPARs in regulating the transcriptional activities of their common ligands was investigated. We show that adipocyte FABP and keratinocyte FABP (A-FABP and K-FABP, respectively) selectively enhance the activities of PPARgamma and PPARbeta, respectively, and that these FABPs massively relocate to the nucleus in response to selective ligands for the PPAR isotype which they activate. We show further that A-FABP and K-FABP interact directly with PPARgamma and PPARbeta and that they do so in a receptor- and ligand-selective manner. Finally, the data demonstrate that the presence of high levels of K-FABP in keratinocytes is essential for PPARbeta-mediated induction of differentiation of these cells. Taken together, the data establish that A-FABP and K-FABP govern the transcriptional activities of their ligands by targeting them to cognate PPARs in the nucleus, thereby enabling PPARs to exert their biological functions.