Large-scale Synthesis and Functional Elements for the Antimicrobial Activity of Defensins

Human neutrophil defensins, and their analogues incorporating anionic, hydrophobic or cationic residues at the N- and C-termini, were synthesized by solid-phase procedures. The synthetic defensins were examined for their microbicidal activity against Candida albicans, two Gram-negative bacteria (Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis) and two Gram-positive bacteria (Streptococcus gordonii and Streptococcus mutans). The human neutrophil peptide 1 (HNP1) and HNP2 were found to be potent candidacidal agents. HNP3, which differs by one amino acid at the N-terminus of its sequence, was totally inactive. The Gram-negative bacteria A. actinomycetemcomitans and P. gingivalis and the Gram-positive bacteria S. gordonii and S. mutans were insensitive to human defensins. However, the insertion of two basic residues, such as arginine, at both the N-terminus and the C-terminus of HNP2 significantly enhanced antifungal and antibacterial activity. The addition of anionic residues, such as aspartic acid, at the N- and C-termini rendered the molecule totally inactive. The presence of two hydrophobic amino acids, such as valine, at the N-terminus of HNP2 and of two basic arginine residues at its C-terminus resulted in molecules that were optimally active against these oral pathogens. The results suggest that the N- and C-terminal residues in defensin peptides are the crucial functional elements that determine their microbicidal potency. The three-dimensional structure of all defensins constitutes the same amphiphilic beta-sheet structure, with the polar face formed by the N- and C-terminal residues playing an important role in defining microbicidal potency and the antimicrobial spectrum. The enhanced microbicidal activity observed for defensin peptides with two basic residues at both the N- and C-termini could be due to optimization of the amphiphilicity of the structure, which could facilitate specific interactions with the microbial membranes

Photoproduction of iodine with nanoparticulate semiconductors and insulators

The crystal structures of different forms of TiO2 and those of BaTiO3, ZnO, SnO2, WO3, CuO, Fe2O3, Fe3O4, ZrO2 and Al2O3 nanoparticles have been deduced by powder X-ray diffraction. Their optical edges have been obtained by UV-visible diffuse reflectance spectra. The photocatalytic activities of these oxides and also those of SiO2 and SiO2 porous to oxidize iodide ion have been determined and compared. The relationships between the photocatalytic activities of the studied oxides and the illumination time, wavelength of illumination, concentration of iodide ion, airflow rate, photon flux, pH, etc., have been obtained. Use of acetonitrile as medium favors the photogeneration of iodine

Pattern of adverse reactions of antipsychotics in a tertiary care hospital

Background: This study was undertaken to analyse the pattern of adverse drug reactions (ADR) of antipsychotics among patients attending the psychiatry outpatient department of a tertiary care centre.Methods: Patients attending the psychiatry outpatient department who have been on treatment with one or more antipsychotics for more than 6 weeks were included in the study. Details about the prescription given in the previous appointment were collected. Various adverse effects associated with the use of antipsychotics were noted and analysed with special importance to obesity, elevated waist circumference and prolongation of QTc interval in ECG.Results: The analysis of various adverse drug reactions in the study showed that the most common CNS side effects were drowsiness and tremor. The prevalence of severe EPS like parkinsonism, tardive dyskinesia and perioral tremors was very low. The prevalence of obesity and overweight was 47% and 14% respectively. The mean BMI of the study population was 24.44. Among the commonly prescribed antipsychotics, prevalence of obesity and overweight was highest in those patients on clozapine. The prevalence of QTc prolongation is 22% in this study.Conclusions: The increasing use of atypical antipsychotics is associated with a different pattern of adverse drug reactions when compared to the typical drugs. Even though the prevalence of EPS is low, there is increased prevalence of metabolic side effects like obesity and diabetes mellitus

Proportion and risk factors of postnatal depression among women delivering in a government tertiary care hospital in Kerala, India

Background: The burden of postpartum depression is significant because it remains unrecognized and it not only affects the mother adversely but also has a negative consequence on the family life and the development of the infant. This research aims to aid the early diagnosis of postnatal depression using Edinburgh postnatal depression scale (EPDS) and the psychosocial and reproductive risk factors of postnatal depression among women delivering in a tertiary hospital in Kerala state, India.Methods: 500 women were subjected to a standard questionnaire for assessing psychosocial and reproductive characteristics. The diagnosis of postnatal depression was made using a pretested and validated Malayalam version of EPDS with a score cut off of 13 or more.Results: The proportion of postnatal depression six weeks after delivery at TD Medical College, Alappuzha was found to be 8.6%. Marital harmony (p value=0.002) was significantly associated with postnatal depression. Diabetes (p value=0.037), hypertensive disorders (p value=0.013), antepartum hemorrhage (p value=0.036), neurological disorders (p value <0.001), type of delivery (p value=0.042), postpartum complications (p value=0.003), mode of infant feeding (p value=0.001), infant illness (p value=0.001), symptoms of maternity blues (p value <0.0001), premenstrual syndromes (p value=0.008) and infertility treatment (p value=0.03) were significantly associated with postnatal depression.Conclusions: Early screening of the women and counselling of women and their family will reduce the maternal morbidity and adverse child outcomes

Biodesalination: an emerging technology for targeted removal of Na+and Cl−from seawater by cyanobacteria

Although desalination by membrane processes is a possible solution to the problem of freshwater supply, related cost and energy demands prohibit its use on a global scale. Hence, there is an emerging necessity for alternative, energy and cost-efficient methods for water desalination. Cyanobacteria are oxygen-producing, photosynthetic bacteria that actively grow in vast blooms both in fresh and seawater bodies. Moreover, cyanobacteria can grow with minimal nutrient requirements and under natural sunlight. Taking these observations together, a consortium of five British Universities was formed to test the principle of using cyanobacteria as ion exchangers, for the specific removal of Na+ and Cl− from seawater. This project consisted of the isolation and characterisation of candidate strains, with central focus on their potential to be osmotically and ionically adaptable. The selection panel resulted in the identification of two Euryhaline strains, one of freshwater (Synechocystis sp. Strain PCC 6803) and one of marine origin (Synechococcus sp. Strain PCC 7002) (Robert Gordon University, Aberdeen). Other work packages were as follows. Genetic manipulations potentially allowed for the expression of a light-driven, Cl−-selective pump in both strains, therefore, enhancing the bioaccumulation of specific ions within the cell (University of Glasgow). Characterisation of surface properties under different salinities (University of Sheffield), ensured that cell–liquid separation efficiency would be maximised post-treatment, as well as monitoring the secretion of mucopolysaccharides in the medium during cell growth. Work at Newcastle University is focused on the social acceptance of this scenario, together with an assessment of the potential risks through the generation and application of a Hazard Analysis and Critical Control Points plan. Finally, researchers in Imperial College (London) designed the process, from biomass production to water treatment and generation of a model photobioreactor. This multimodal approach has produced promising first results, and further optimisation is expected to result in mass scaling of this process

Structural, Optical and Electrical Properties of Undoped and Doped ZnO Thin Films

ZnO, which has high electrochemical stability, wide band gap energy, large excitonic binding energy, intense near band excitonic emission and is non-toxic, have potential applications in all fields. This chapter reviews the structural, optical and electrical properties of undoped and doped ZnO thin films. The type of doping highly influences the structural properties such as grain size, texture coefficient and unit cell properties. The dopants of transition metal and nonmetals have unique characteristics. Moreover, mono-doping and co-doping encourage this research. The optical properties such as bandgap, charge carrier concentrations and transmissions of the films depend on the doping as well as the preparation condition of the films. The effect of doping on its properties is also discussed

Results of exploratory trawl fishing on the continental slope of the south west coast of India by M.F.V. 'Kalava'

So far, extensive deep sea trawling, in waters beyond 100 fathom depths, has not been attempted in Indian waters except for occasional hauls taken by the INVESTIGATOR (Alcock, 1891-1900) and other Expedition vessels (Gunther, 1887, Max Weber, 1913. Norman, 1939). During March-May 1963 M.F.V. 'Kalava' of the Indo-Norwegian Project, carried out 9 exploratory cruises off Alleppey and Ponnani on the South West Coast of India at depths ranging between 150 to 205 fathoms (274-374 m.). Large quantities of bathypelagic fish were taken during these cruises, in areas on the continental slope (Fig. 1). 24 species belonging to 23 genera and 19 families have already been described by Tholasilingam et al. (1964). Nearly 82% of the catch was represented by about 11 bathypelagic species taken at the rate of up to 496 kg. per hour of trawl, in the richest grounds. Since such occurrence has not been recorded so far, a quantitative assessment of these bathypelagic fishes along with deep sea prawns, lobsters and squids, has been given in the following pape

Antimicrobial Activity of Aegle marmelos Against Pathogenic Organism Compared with Control Drug

The aqueous and ethanolic extracts from the leaves of Aegle marmelos traditionally used in Indian system of Medicines were screened against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis by using disc diffusion test technique. Bacillus subtilis exhibit about 22mm inhibition zone were considered resistant. The zone of inhibition of the extract was compared with the standard antibiotics such as Penicillin. The study suggests that the plant is promising development of phytomedicine for antimicrobial properties

Regeneration of cellulose acetate nanofibrous mat from discarded cigarette butts

Cellulose acetate present in the cigarette butts has beenregenerated into nanofibrous mat. The developed mat is thencharacterized using various analytical tools. Uniform bead-freecellulose acetate fibre is obtained at 12 % w/v concentration ofcellulose acetate. The mat thus obtained exhibits goodantimicrobial property