Corona Virus Disease 2019 (COVID-19) Diagnostic Tests: A Glimpse.

Mass testing for COVID-19 infection is one of the core measures in tackling the global spread of the disease. Testing is vital to diagnose and estimate cases, attack rates and case fatality rates- critical data for policy-making. As COVID-19 continues to spread globally, the demand for more extensive laboratory testing and innovative technology increases. However, countries around the world have been struggling to keep up pace with the worldwide demand to expand testing strategy. The pandemic evolves, so does our knowledge and understanding of diagnostic tests of COVID-19. Here we aim to review major challenges related to COVID-19 diagnostic tests and future development. So, the ongoing urgency and demand for tests would certainly steer the rapid uptake of novel techniques, which in turn would boost our understanding of diagnostic tests for COVID-19.

Pandemic Now and Then: A Historical Perspective of Non-Pharmaceutical Interventions Adopted In Covid-19.

The coronavirus disease 2019 (COVID-19), first reported in Wuhan, China is now a major global health threat - a pandemic. Public health control measures are the cornerstones in the fight against COVID-19 in the absence of an effective vaccine or proven treatment. The aim of this review was to explore the historical use case of various public health measures adopted today to tackle COVID-19 spread. Although our knowledge about this novel coronavirus transmission is evolving over time, the fundamental non-pharmaceutical interventions e.g., handwashing, wearing a mask, physical distancing, isolation, quarantine and border control which are adopted globally at present are not new. This review highlighted that historically and religiously similar approaches were practised in the medieval past for controlling disease outbreaks. The successful implementation of the public health control measures largely depends on health systems resilience, community engagement and changes in population behaviour. Combined global efforts are essential to strengthen health systems, improve the capability of research and transparent information sharing with both public and international bodies to combat the pandemic.

Development of Cryopreservation Protocol for Aquilaria malaccensis Lam., a Recalcitrant Seeded Tropical Tree Species.

BACKGROUND: Cryopreservation is the only possible process for long-term germplasm storage of species with recalcitrant behavior. Aquilaria malaccensis is a recalcitrant seeded tropical tree that produces a distinctive fragrance which has high value in the commercial market. OBJECTIVES: In the present study, we aimed to develop possible long-term storage techniques for A. malaccensis germplasm. MATERIALS AND METHODS: We used zygotic embryos and in vitro derived nodal buds as explants. The experiments were performed based on dehydration and encapsulation-dehydration methods. RESULTS: When the dehydration technique was applied, survival (43%) and regeneration (23%) was found to be higher for zygotic embryos than for in vitro derived nodal buds (13% & 10% respectively). In addition to moisture content within the tissue during cryogen exposure, dehydration duration has an important contributory role in post cryo-survival and regeneration. A slight increase in survival (47%) and regeneration (30%) were observed in zygotic embryos with a modification to rehydration after re-warming, while such a change did not improve success with in vitro derived nodal buds. In contrast, the encapsulation-dehydration technique was found to be more effective for in vitro derived nodal buds than zygotic embryos. All the encapsulated nodal buds that survived (27%) regenerated into plantlets while encapsulated zygotic embryos failed to regenerate into plantlets. CONCLUSION: This is the first report on the cryopreservation of A. malaccensis and the developed protocol conveys a comprehensive idea of its reliability for the long-term storage of this desiccation sensitive (recalcitrant) seeded tree species.

Evaluation of Acute Oral Toxicity of Ethanol Leaves Extract of Catharanthus roseus in Wistar Albino Rats.

INTRODUCTION: Herbal drugs have gained importance globally in the treatment of various diseases. Catharanthus roseus is traditionally used as an anti diabetic and anti cancer drug. To the best of our knowledge limited data are available on acute and sub acute toxicity of C. roseus extract despite its wide spread use in traditional medicine. The present study was under taken to evaluate the acute oral toxicity of the ethanol leaves extract of C. roseus. AIM: To investigate the acute oral toxic effects of ethanol leaves extract of C. roseus. The objective of the study was to evaluate organ toxicity related to heart, liver and kidney in wistar albino rats. MATERIALS AND METHODS: The experiment was done based on the Organization for Economic Co-operation and Development (OECD) guideline 420. The study included twenty five non pregnant female wistar rats (n=25). Sighting study was done using the fixed dose method. The study was conducted by giving a single dose of test drug varying from 5, 50, 300 and 2000 mg and animals were observed for fourteen days. Blood samples were collected and biochemical findings SGPT, SGOT, urea, creatinine, creatinine phosphokinase and Lactate Dehydrogenase (LDH) were analyzed. Food consumption, water intake and histopathology changes were evaluated. RESULTS: Catharanthus roseus Extract (CRE) at a dose of 2000 mg did not produce mortality. SGOT, SGPT, Creatinine phosphokinase, LDH, urea and creatinine were elevated in 300 mg and 2000 mg doses. CONCLUSION: Though there was no mortality, the extract of C. roseus higher than 300 mg can produce signs of biochemical and histopathological toxicity in liver, kidney and heart. It is recommended that lower doses than the studied ones should be used for treatment.

Potentiation of antibiotic against Pseudomonas aeruginosa biofilm: a study with plumbagin and gentamicin.

AIMS: Pseudomonas aeruginosa is one of the fatal biofilm-forming pathogens which pose to be a problem in clinical infections, contamination of food and marine ecosystems. In this report, a naphthoquinone-plumbagin has been explored for its antimicrobial (antibacterial and antibiofilm) activity against P. aeruginosa biofilm. The ability of plumbagin to enhance the bioactivity of a known broad-spectrum antibiotic was further assayed by combining the sub-MIC doses of plumbagin with sub-MIC doses of gentamicin against P. aeruginosa biofilm. METHODS AND RESULTS: This combinatorial approach was used for a series of experiments for understanding the mechanism of action for antibiofilm activity against P. aeruginosa (MTCC 424, MTCC 2488). Antibiofilm activity was studied by safranin staining, estimating total protein, visualization of biofilms and extra polymeric substances quantification. Antivirulent activity of these doses was studied by azocasein degradation, expression of virulent factors and molecular docking. Expression of quorum sensing (QS) phenotypes was studied by motility assessment and mRNA expression pattern of virulence genes. It was observed that plumbagin alone and the combinatorial doses of plumbagin and gentamicin exhibit significant antibiofilm and antivirulent activity coupled with the reduction in the expression of QS phenotypes and virulence genes. Molecular docking study revealed that plumbagin had variable affinity for different QS proteins. CONCLUSION: Low doses of plumbagin and gentamicin exhibit synergistic activity against P. aeruginosa biofilm while maintaining their effectiveness. SIGNIFICANCE AND IMPACT OF THE STUDY: As the P. aeruginosa biofilms are reservoir of persister bacteria, thus, the increasing concern of antibiotic tolerance has to be dealt with combinatorial approaches. In this report, plumbagin has been explored in potentiating the antibiofilm effect of a broad-spectrum antibiotic gentamicin for better therapeutic efficacy.

3-Amino-4-aminoximidofurazan derivatives: small molecules possessing antimicrobial and antibiofilm activity against Staphylococcus aureus and Pseudomonas aeruginosa.

AIM: The therapeutic treatment of microbial infections involving biofilm becomes quite challenging because of its increasing antibiotic resistance capacities. Towards this direction, in the present study we have evaluated the antibiofilm property of synthesized 3-amino-4-aminoximidofurazan compounds having polyamine skeleton. These derivatives were synthesized by incorporating furazan and biguanide moieties. METHODS AND RESULTS: Different 3-amino-4-aminoximidofurazan derivatives (PI1-4) were synthesized via protic acid catalysis and subsequently characterized by (1) H NMR and (13) C NMR spectra, recorded at 400 and 100 MHz respectively. We have tested the antimicrobial and antibiofilm activities of these synthetic derivatives (PI1-4) against both Staphylococcus aureus and Pseudomonas aeruginosa. The compounds so tested were also compared with standard antibiotics namely Tobramycin (Ps. aeruginosa) and Azithromycin (Staph. aureus) which were used as a positive control in all experimental sets. All these compounds (PI1-4) exhibited moderate to significant antimicrobial activities against both micro-organisms wherein compound PI3 showed maximum activity. Biofilm inhibition of both micro-organisms was then evaluated by crystal violet and safranin staining, estimation of biofilm total protein and microscopy methods using sub-MIC dose of these compounds. Results showed that all compounds executed anti biofilm activity against both Staph. aureus and Ps. aeruginosa wherein compound PI3 exhibited maximum activity. In relation with microbial biofilm inhibition, we have observed reduction in bacterial motility, proteolytic activity and secreted exo-polysaccharide (EPS) from both Staph. aureus and Ps. aeruginosa when they were grown in presence of these compounds. While addressing the issue of toxicity on host, we have observed that these molecules exhibited minimum level of R.B.C degradation. CONCLUSION: These findings establish the antibacterial and anti biofilm properties of 3-amino-4-aminoximidofurazan derivatives (PI1-4). SIGNIFICANCE AND IMPACT OF THE STUDY: Therefore, our current findings demonstrate that 3-amino-4-aminoximidofurazan derivatives (PI1-4) may hold promise to be effective biofilm and microbial inhibitors that may be clinically significant.

A comparative study on the effect of felodipine and propranolol on serum lipid profile of rabbits.

Effect of felodipine on serum lipids of rabbits was studied and was compared with that of propranolol. Lipid parameters were estimated at basal (0 wk), end of 4th and 16th week of diet/drug administration by using standard kits for analysis. There was a significant increase in mean serum cholesterol, TG, VLDLc, LDLC and decrease in HDLc, (P<0.05) in the group of rabbits receiving Atherogenic diet (AD)/Propranolol. This effect was maximally observed in rabbits receiving both AD and propranolol. This change was satisfactorily prevented when felodipine was administered from very beginning (P<0.001). In addition, there was a significant increase in HDLc (28.89%) of rabbits receiving felodipine from beginning. Thus both AD and propranolol have dyslipidemic effect and early administration of felodipine favorably changes all lipid parameters.

Temperature-absorption transition spectroscopy: a technique for estimating the relative charge densities on thiolated phosphate groups in nucleic acid analogues.

Various polynucleotides with well-defined sequences at low salt concentration have been studied using temperature-absorbtion transition spectroscopy to understand their conformations. It has been observed that the adopted technique can fairly estimate the relative charge densities at the thiolated phosphate groups in nucleic acid analogues at low salt concentrations.