Multiplex detection of bacterial pathogens by PCR/SERS assay.

Bacterial infections are a leading cause of death globally. The detection of DNA sequences correlated to the causative pathogen has become a vital tool in medical diagnostics. In practice, PCR-based assays for the simultaneous detection of multiple pathogens currently rely on probe-based quantitative strategies that require expensive equipment but have limited sensitivity or multiplexing capabilities.

Evaluation of a telemedicine-enabled universal eye health delivery model in rural southern India.

Objectives: To evaluate the accuracy of tele-ophthalmic examination (TOE) for common ocular conditions in comparison with the gold-standard in-person examination (IPE) for diagnosis and treatment advice.

Methods: In a prospective, diagnostic accuracy validation study, we recruited 339 consecutive new patients, aged ≥16 years, visiting a vision centre (VC) associated with Aravind Eye Hospital in south India during January and February, 2020. All participants underwent the TOE, followed by IPE on the same visit.

Methods for a population-based Comprehensive Eye care Workload Assessment (CEWA) study in Southern India.

Eye care programs, in developing countries, are often planned using the prevalence of blindness and visual impairment, often estimated from Rapid Assessment of Avoidable Blindness (RAAB) surveys. A limitation of this planning approach is that it ignores the annual overall eye care requirements for a given population. Moreover, targets set are arbitrary, often influenced by capacity rather than need.

Highly specific detection of KRAS single nucleotide polymorphism by asymmetric PCR/SERS assay.

The molecular diagnosis of KRAS mutations has become crucial for clinical decision-making in colorectal cancer (CRC) treatments. Currently, the common methods for detecting mutations are based on quantitative PCR, DNA sequencing and droplet digital PCR (ddPCR), which require expensive specialized equipment and testing reagents. Herein, we propose a simple and specific strategy by integrating asymmetric PCR with surface-enhanced Raman spectroscopy (Asy-PCR/SERS) for the detection of KRAS G12V mutation, one of the most common driver mutations in CRC.

Multiplex detection of ctDNA mutations in plasma of colorectal cancer patients by PCR/SERS assay.

Molecular diagnostic testing of KRAS and BRAF mutations has become critical in the management of colorectal cancer (CRC) patients. Some progress has been made in liquid biopsy detection of mutations in circulating tumor DNA (ctDNA), which is a fraction of circulating cell-free DNA (cfDNA), but slow analysis for DNA sequencing methods has limited rapid diagnostics. Other methods such as quantitative PCR and more recently, droplet digital PCR (ddPCR), have limitations in multiplexed capacity and the need for expensive specialized equipment.

Smartphone technology facilitates point-of-care nucleic acid diagnosis: a beginner's guide.

The reliable detection of nucleic acids at low concentrations in clinical samples like blood, urine and saliva, and in food can be achieved by nucleic acid amplification methods. Several portable and hand-held devices have been developed to translate these laboratory-based methods to point-of-care (POC) settings. POC diagnostic devices could potentially play an important role in environmental monitoring, health, and food safety.

Sensitive and Direct DNA Mutation Detection by Surface-Enhanced Raman Spectroscopy Using Rational Designed and Tunable Plasmonic Nanostructures.

Efficient DNA mutation detection methods are required for diagnosis, personalized therapy development, and prognosis assessment for diseases such as cancer. To address this issue, we proposed a straightforward approach by combining active plasmonic nanostructures, surface-enhanced Raman spectroscopy (SERS), and polymerase chain reaction (PCR) with a statistical tool to identify and classify BRAF wild type (WT) and V600E mutant genes. The nanostructures provide enhanced sensitivity, while PCR offers high specificity toward target DNA.

Rapid and specific duplex detection of methicillin-resistant Staphylococcus aureus genes by surface-enhanced Raman spectroscopy.

Methicillin-resistant Staphylococcus aureus (MRSA) is considered to be one of the important hospital-acquired pathogens. MRSA is also commonly associated with hospital-acquired infections and mortality. Quantitative and precise detection of MRSA is essential for rapid diagnosis and subsequent effective disease management strategies.

Linker-protein G mediated functionalization of polystyrene-encapsulated upconversion nanoparticles for rapid gene assay using convective PCR.

The authors report on a simplified approach to encapsulate upconversion nanoparticles (UCNPs) in polystyrene spheres by mini-emulsion polymerisation. The resulting particles (PS-UCNP) are hydrophilic, stable and suitable for biomolecular recognition and biosensing applications. Also, a strategy was developed for bioconjugation of antibodies onto the surface of the PS-UCNPs by using the bifunctional fusion protein linker-protein G (LPG).

A portable nucleic acid detection system using natural convection combined with a smartphone.

The development of portable nucleic acid diagnostic devices has the potential to expand the availability of molecular diagnostics into low-resource settings. One of the promising solutions for rapid and simple DNA amplification is the use of Rayleigh-Bernard natural convection which is caused by a buoyancy-driven thermal gradient of liquid when heated from below. This natural convection avoids the use of the complex and sophisticated hardware that is required for precise maintenance of temperature cycles in conventional PCR.

Mechanical perturbations trigger endothelial nitric oxide synthase activity in human red blood cells.

Nitric oxide (NO), a vascular signaling molecule, is primarily produced by endothelial NO synthase. Recently, a functional endothelial NO synthase (eNOS) was described in red blood cells (RBC). The RBC-eNOS contributes to the intravascular NO pool and regulates physiological functions.

Cadmium-induced embryopathy: nitric oxide rescues teratogenic effects of cadmium.

Although Cadmium (Cd) is a well-known heavy metal pollutant and teratogen, the mechanism behind Cd-mediated teratogenicity remains unknown. Previously, we have reported of the protective role of Nitric oxide (NO), a key signaling molecule in the embryonic developmental process, against Thalidomide-induced teratogenicity. The objective of this study was to obtain a mechanistic in-sight of the antiteratogenic potential of NO against Cd-mediated teratogenicity.

A direct detection of Escherichia coli genomic DNA using gold nanoprobes.

Background: In situation like diagnosis of clinical and forensic samples there exists a need for highly sensitive, rapid and specific DNA detection methods. Though conventional DNA amplification using PCR can provide fast results, it is not widely practised in diagnostic laboratories partially because it requires skilled personnel and expensive equipment. To overcome these limitations nanoparticles have been explored as signalling probes for ultrasensitive DNA detection that can be used in field applications.