Evaluation of a Field-Deployable Reverse Transcription-Insulated Isothermal PCR for Rapid and Sensitive On-Site Detection of Zika Virus

Background: The recent emergence of Zika virus (ZIKV) in Brazil and its precipitous expansion throughout the Americas has highlighted the urgent need for a rapid and reliable on-site diagnostic assay suitable for viral detection. Such point-of-need (PON), low-cost diagnostics are essential for ZIKV control in vulnerable areas with limited resources. Methods: We developed and evaluated a ZIKV-specific field-deployable RT-iiPCR reagent set targeting the E gene for rapid detection of ZIKV in ZIKV-spiked human and mosquito specimens, and compared its performance to the Center for Disease Control and Prevention (CDC) and Pan American Health Organization (PAHO) RT-qPCR assays targeting the E and NS2B genes, respectively. Results: These assays demonstrated exclusive specificity for ZIKV (African and Asian lineages), had limits of detection ranging from 10 to 100 in vitro transcribed RNA copies/μl and detection endpoints at 10 plaque forming units/ml of infectious tissue culture fluid. Analysis of human whole blood, plasma, serum, semen, urine, and mosquito pool samples spiked with ZIKV showed an agreement of 90% (k = 0.80), 92% (k = 0.82), 95% (k = 0.86), 92% (k = 0.81), 90% (k = 0.79), and 100% (k = 1), respectively, between the RT-iiPCR assay and composite results from the reference RT-qPCR assays. Overall, the concurrence between the ZIKV RT-iiPCR and the reference RT-qPCR assays was 92% (k = 0.83). Conclusions: The ZIKV RT-iiPCR has a performance comparable to the reference CDC and PAHO RT-qPCR assays but provides much faster results (~1.5 h) with a field-deployable system that can be utilized as a PON diagnostic with the potential to significantly improve the quality of the health care system in vulnerable areas

Clinical Study of Uric Acid Urolithiasis

Uric acid urolithiasis develops from various causes. To investigate the clinical and biochemical presentation of patients with uric acid urolithiasis, a retrospective study was designed. A total of 46 cases were enrolled between January 2004 and December 2005. The compositions of the stones were analyzed by infrared spectrophotometry. There were 39 males (84.8%) and seven females (15.2%), with a mean age of 61.5 ± 10.6 years and mean body mass index (BMI) of 26.7 ± 3.1 kg/m2. The stone location was kidney in 10 (21.7%), ureter in 22 (41.8%), and bladder in 14 (30.5%). Multiple stones were diagnosed in 36 patients (78.3%). Pre-existing comorbidities included diabetes mellitus in 11 patients (23.9%), hypertension in 23 (50%), gout in 13 (28.2%), and benign prostatic hyperplasia in 14 (30.4%). Mean serum creatinine and uric acid was 1.6 ± 0.6 mg/dL and 7.6 ± 1.8 mg/dL, respectively. There were 27 patients (58%) with creatinine > 1.4 mg/dL. The mean urinary pH was 5.42 ± 0.46. Patients with uric acid urolithiasis were predominantly male, older, with higher BMI, multiple stone presentation, with lower urinary pH, and hyperuricemia. Exacerbation of the renal function should also be of concern because of the high proportion of patients with renal insufficiency diagnosed in this study

The presence of broadly neutralizing anti-SARS-CoV-2 RBD antibodies elicited by primary series and booster dose of COVID-19 vaccine

Antibody-mediated immunity plays a key role in protection against SARS-CoV-2. We characterized B-cell-derived anti-SARS-CoV-2 RBD antibody repertoires from vaccinated and infected individuals and elucidate the mechanism of action of broadly neutralizing antibodies and dissect antibodies at the epitope level. The breadth and clonality of anti-RBD B cell response varies among individuals. The majority of neutralizing antibody clones lose or exhibit reduced activities against Beta, Delta, and Omicron variants. Nevertheless, a portion of anti-RBD antibody clones that develops after a primary series or booster dose of COVID-19 vaccination exhibit broad neutralization against emerging Omicron BA.2, BA.4, BA.5, BQ.1.1, XBB.1.5 and XBB.1.16 variants. These broadly neutralizing antibodies share genetic features including a conserved usage of the IGHV3-53 and 3–9 genes and recognize three clustered epitopes of the RBD, including epitopes that partially overlap the classically defined set identified early in the pandemic. The Fab-RBD crystal and Fab-Spike complex structures corroborate the epitope grouping of antibodies and reveal the detailed binding mode of broadly neutralizing antibodies. Structure-guided mutagenesis improves binding and neutralization potency of antibody with Omicron variants via a single amino-substitution. Together, these results provide an immunological basis for partial protection against severe COVID-19 by the ancestral strain-based vaccine and indicate guidance for next generation monoclonal antibody development and vaccine design

Synthesis of two-dimensional TlxBi1-x compounds and Archimedean encoding of their atomic structure

Crystalline atomic layers on solid surfaces are composed of a single building block, unit cell, that is copied and stacked together to form the entire two-dimensional crystal structure. However, it appears that this is not an unique possibility. We report here on synthesis and characterization of the one-atomic-layer-thick TlxBi1−x compounds which display quite a different arrangement. It represents a quasi-periodic tiling structures that are built by a set of tiling elements as building blocks. Though the layer is lacking strict periodicity, it shows up as an ideally-packed tiling of basic elements without any skips or halting. The two-dimensional TlxBi1−x compounds were formed by depositing Bi onto the Tl-covered Si(111) surface where Bi atoms substitute appropriate amount of Tl atoms. Atomic structure of each tiling element as well as arrangement of TlxBi1−x compounds were established in a detail. Electronic properties and spin texture of the selected compounds having periodic structures were characterized. The shown example demonstrates possibility for the formation of the exotic low-dimensional materials via unusual growth mechanisms

A Pan-Dengue Virus Reverse Transcription-Insulated Isothermal PCR Assay Intended for Point-of-Need Diagnosis of Dengue Virus Infection by Use of the POCKIT Nucleic Acid Analyzer

Dengue virus (DENV) infection is considered a major public health problem in developing tropical countries where the virus is endemic and continues to cause major disease outbreaks every year. Here, we describe the development of a novel, inexpensive, and user-friendly diagnostic assay based on a reverse transcription-insulated isothermal PCR (RT-iiPCR) method for the detection of all four serotypes of DENV in clinical samples. The diagnostic performance of the newly established pan-DENV RT-iiPCR assay targeting a conserved 3′ untranslated region of the viral genome was evaluated. The limit of detection with a 95% confidence was estimated to be 10 copies of in vitro-transcribed (IVT) RNA. Sensitivity analysis using RNA prepared from 10-fold serial dilutions of tissue culture fluid containing DENVs suggested that the RT-iiPCR assay was comparable to the multiplex real-time quantitative RT-PCR (qRT-PCR) assay for DENV-1, -3, and -4 detection but 10-fold less sensitive for DENV-2 detection. Subsequently, plasma collected from patients suspected of dengue virus infection (n = 220) and individuals not suspected of dengue virus infection (n = 45) were tested by the RT-iiPCR and compared to original test results using a DENV NS1 antigen rapid test and the qRT-PCR. The diagnostic agreement of the pan-DENV RT-iiPCR, NS1 antigen rapid test, and qRT-PCR tests was 93.9%, 84.5%, and 97.4%, respectively, compared to the composite reference results. This new RT-iiPCR assay along with the portable POCKIT nucleic acid analyzer could provide a highly reliable, sensitive, and specific point-of-need diagnostic assay for the diagnosis of DENV in clinics and hospitals in developing countries

Permissive hypotensive resuscitation in patients with traumatic hemorrhagic shock

Abstract We read the article “Risks and benefits of hypotensive resuscitation in patients with traumatic hemorrhagic shock: a meta-analysis” by Natthida Owattanapanich et al. with great interest and found it to be insightful. In our commentary, we propose possible reasons why mortality was lower in the permissive hypotension group and how the need for blood transfusion decreased in this group. No significant difference in acute kidney injury (AKI) was evident among patient groups, possibly because all these patients might have AKI. However, we do agree that permissive hypotension is of considerable benefit to trauma patients and worth further study

Efficiency Analysis of Direct Video-Assisted Thoracoscopic Surgery in Elderly Patients with Blunt Traumatic Hemothorax without an Initial Thoracostomy

Hemothorax is common in elderly patients following blunt chest trauma. Traditionally, tube thoracostomy is the first choice for managing this complication. The goal of this study was to determine the benefits of this approach in elderly patients with and without an initial tube thoracostomy. Seventy-eight patients aged >65 years with blunt chest trauma and stable vital signs were included. All of them had more than 300 mL of hemothorax, indicating that a tube thoracostomy was necessary. The basic demographic data and clinical outcomes of patients with hemothorax who underwent direct video-assisted thoracoscopic surgery without a tube thoracostomy were compared with those who received an initial tube thoracostomy. Patients who did not receive a thoracostomy had lower posttrauma infection rates (28.6% versus 56.3%, P=0.061) and a significantly shorter length of stay in the intensive care unit (3.13 versus 8.27, P=0.029) and in the hospital (15.93 versus 23.17, P=0.01) compared with those who received a thoracostomy. The clinical outcomes in the patients who received direct VATS were more favorable compared with those of the patients who did not receive direct VATS