Non-cytotoxic effect of green synthesized silver nanoparticles and its antibacterial activity.

Silver nanoparticles (AgNPs) were green synthesized using ethanolic extract of fenugreek leaves and characterized using UV-Vis spectroscopy, Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), high resolution transmission electron microscopy HRTEM and energy dispersive X-ray analysis (EDX) techniques. The HRTEM results revealed the formation of highly stable, mono dispersed, spherical shaped AgNPs with the size ranging from 20 to 30nm. The presence of flavonoids and their interaction with the AgNPs were confirmed using FTIR. Antibacterial activities of the AgNPs were studied against pathogenic gram-positive Staphylococcus aureus (S. aureus) and gram negative Escherichia coli (E. coli) bacteria. The synthesized AgNPs displayed the enhancement of antibacterial activity against E. coli. The morphological changes in the bacterial cell membrane was observed using SEM analysis. Leakage of protein from the bacterial cells increased at every time intervals (2 and 4h). MTT assay was carried out for the AgNPs against human skin cell line (HaCaT). Interestingly, cytotoxicity of the synthesized AgNPs was less toxic to HaCaT cells as compared to bacteria cells, which suggests that the synthesized AgNPs by this method is eco-friendly in nature.

Bioremediation of heavy metals using an endophytic bacterium Paenibacillus sp. RM isolated from the roots of Tridax procumbens.

The aim of the present study was to assess the bioremediation potential of endophytic bacteria isolated from roots of Tridax procumbens plant. Five bacterial endophytes were isolated and subsequently tested for minimal inhibitory concentration (MIC) against different heavy metals. Amongst the five isolates, strain RM exhibited the highest resistance to copper (750 mg/l), followed by zinc (500 mg/l), lead (450 mg/l), and arsenic (400 mg/l). Phylogenetic analysis of the 16S rDNA sequence suggested that strain RM was a member of genus Paneibacillus. Strain RM also had the capacity to produce secondary metabolites, indole acetic acid, siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and biosurfactant and solubilize phosphate. The growth kinetics of strain RM was altered slightly in the presence of metal stress. Temperature and pH influenced the metal removal rate. The results suggest that strain RM can survive under the high concentration of heavy metals and has been identified as a potential candidate for application in bioremediation of heavy metals in contaminated environments.

Determination of LC50 and sub-chronic neurotoxicity of diesel exhaust nanoparticles.

Air pollution is a major problem faced globally and is seen associated with central nervous system (CNS) disorders like neuropathology and neuro-inflammation. Here, we investigated the CNS disorders as a result of sub-chronic exposure (90 days) to diesel exhaust nanoparticles (DENPs) and explored the minimal levels of DENPs needed to exhibit the early mediators of neuro-inflammation and neuropathology. Male and female wistar rats (6 rats per group) were exposed to DENPs (1/5th, 1/10th and 1/15th LC50) by inhalation for 4h per day, 5 days per week over 90 days and neurotoxicity end-points were analyzed. DENP exposure caused elevation in levels of pro-inflammatory cytokines, amyloid beta 42 (Aß 42), reactive oxygen species (ROS), hydrogen peroxide (H2O2), nitrate (NO3(-)), nitrite (NO2(-)) and apurinic/apyrimidinic sites (AP) at varying degrees at different sections of rat brain. Hence, exposure to DENPs resulted in dose-dependent toxicity and was closely correlated to increased inflammation, DNA damage and oxidative stress.

Facile Synthesis of Curcumin Nanocrystals and Validation of Its Antioxidant Activity Against Circulatory Toxicity in Wistar Rats.

Our investigation was carried out in two phases. First we synthesized curcumin nanocrystals using a simple precipitation method and characterized their absorbance, crystallinity, size, and morphology by UV-visible spectroscopy, X-ray diffraction (XRD) spectroscopy, High Resolution Transmission Electron Microscopy (HRTEM) and Particle size Analyzer (PSA), in comparison with bulk curcumin. Characterization studies revealed that the protocol we standardized resulted in Curcumin nanocrystals with 10-200 nm size which was fairly soluble in water in contrast to bulk curcumin. Due to its crystallinity, nanocurcumin that we synthesized was also referred as Curcumin Nanocrystals. In Phase 2, we have assessed the comparative antioxidant efficacy of Curcumin nanocrystals and bulk Curcumin in the circulation of 1,2-dimethyl hydrazine-treated rats by investigating lipid peroxidation, antioxidant enzymes (superoxide dismutase, catalase), GSH and GSH-dependent detoxification enzymes (glutathione peroxidase, gIutathione-S-transferase). Curcumin nanocrystals exerted its antioxidant effect by decreasing lipid peroxidation, and by enhancing the activities of antioxidant and detoxification enzymes studied. Curcumin nanocrystals exhibited its antioxidant action at 40 mg dose whereas the bulk curcumin exerted its effect at 80 mg dose. This may be due to enhanced solubility, dispersibility, and crystallinity of the nanocrystals, which might have enhanced its bioavailability when compared to poorly soluble bulk curcumin.

Infection with hepatitis C virus genotype 3--experience of a tertiary health care centre in south India.

To analyse the response rate and the predictive values of virological, biochemical and histological factors on HCV antiviral therapy in HCV genotype 3 infected patients, we retrospectively studied 21 HCV genotype 3 infected patients, who underwent HCV antiviral therapy. Low (57%) sustained viral response (SVR) rate and significant association of SVR with normalization of alanine transaminase (ALT) levels were observed in our study. Absence of early viral response (EVR) showed high (80%) predictive value on SVR. Absence of EVR and normalisation of the ALT levels can predict the outcome of HCV antiviral therapy.

Bacterial degradation and corrosion of naphtha in transporting pipeline.

Five naphtha hydrocarbon-degrading bacteria including representative strains of the two classified species (Serratia marcescensAR1, Bacillus pumilusAR2, Bacillus carboniphilus AR3, Bacillus megaterium AR4, and Bacillus cereus AR5) were identified by 16S rDNA gene sequence in a naphtha-transporting pipeline. The naphtha-degrading strains were able to be involved in the corrosion process of API 5LX steel and also utilized the naphtha as the sole carbon source. The biodegradation of naphtha by the bacterial isolates was characterized by gas chromatography-mass spectrometry. Weight-loss measurement on the corrosion of API 5LX steel in the presence/absence of consortia grown in naphtha-water aqueous media was performed. The scanning electron microscope observation showed that the consortia were able to attack the steel API 5LX surface, creating localized corrosion (pit). The biodegradation of naphtha by the strains AR1, AR2, AR3, AR4, and AR5 showed biodegradation efficiency of about 76.21, 67.20, 68.78, 68.78, and 68.15, respectively. The role of degradation on corrosion has been discussed. This basic study will be useful for the development of new approaches for the detection, monitoring, and control of microbial corrosion in a petroleum product pipeline.

Microbiologically influenced corrosion in petroleum product pipelines--a review.

Microbiologically influenced corrosion is responsible for most of the internal corrosion problems in oil transportation pipelines and storage tanks. One problematic area in treating gas lines is the occurrence of the stratification of water in the line. Under these conditions, corrosion inhibitors do not come into contact properly and oil and inhibitors undergo degradation. The role of bacteria on oil degradation, the consequences of oil degradation in fuel systems and its influence on corrosion have been explained in detail. Besides, factors influencing on degradation of oil and corrosion inhibitors have also been discussed. Mechanism of microbiologically influenced corrosion in oil pipeline has been explained. Many of the misapplication of biocides/inhibitors occur mainly because the characteristics of biocides/inhibitors are not considered before use in pipeline industry. List of biocides and monitoring programme have been collected from literature and presented.

Chylous ascites: a rare complication of radical gastrectomy.

Chylous ascites is the accumulation of lymphatic fluid within the peritoneal cavity, due to trauma or obstruction to the lymphatic system. Postoperative chylous ascites is a rare complication of abdominal surgery. This is frequently reported after retroperitoneal dissections, and results in high morbidity and mortality. The treatment options are varied and include total parenteral nutrition (TPN), elemental diet with medium chain triglycerides (MCT), repeated paracentesis and surgical ligation. We report a case of post-operative chylous ascites after D2 distal gastrectomy. Treatment by fasting, TPN followed by fat-free diet resulted in complete resolution of ascites within 3 weeks. To our knowledge this is the first report of such a complication following radical gastrectomy. We review the literature and briefly discuss the management options.

Retroperitoneal perforation of duodenal ulcer presenting as scrotal sepsis.

Retroperitoneal extravasation is an extremely uncommon complication of duodenal ulcer perforation. The preoperative diagnosis is difficult and may even by missed at operation. There were 25 cases reported in the literature. Only one patient was correctly diagnosed preoperatively and only seven patients survived. We describe the first case of retroperitoneal extravasation from perforated duodenal ulcer presenting as scrotal sepsis.

Temporal quantification of Alzheimer's disease severity: 'time index' model.

A fundamental issue in the clinical and neuropathological assessment of Alzheimer's disease patients is quantification of dementia severity progression. Several methods have been advanced for the purpose of staging dementia with various sensitivities at different phases of the disease, but no mathematical function has been developed to link these measures to a physical continuum. Using a dynamic method for quantifying illness severity, change in severity over time was referenced to a cumulative temporal index, a physical dimension. Data from 33 patients with probable Alzheimer's disease with at least 2 successive assessments on three 50-point scales measuring cognitive, behavioral, and daily living skills were used to determine rate of change. 'Fuzzylogic' smoothing of the data, integration over time, and least-squares regression were used to derive a cubic polynomial function to calculate a severity measure in which 'days of illness' was estimated from the severity score. This method can be used to improve the comparability of performance across various mental status tests, and to link measures of very early phases of preclinical dementia and late profound dementia phases. This method also provides a description of an 'average' time course for any population from which the index is derived.