Red-emitting polyaniline-based nanoparticle probe for pH-sensitive fluorescence imaging.

Fluorescent probes based on semiconducting polymer nanoparticles (NPs) such as polyaniline (PANI) usually require external fluorophore doping to provide fluorescence function. Direct use of PANI-based NPs for bioimaging applications has been limited by PANI's weak blue fluorescence and aggregation-induced quenching in physiological medium. In this report, we developed a facile solid-state synthesis method to produce fluorescent polyaniline nanoparticles (FPNs) that are not only water-soluble but also exhibit high intensity and pH-sensitive red fluorescence. The FPNs showed high photoluminescence quantum yield (PLQY) of 19.3 % at physiological pH, which makes FPNs ideal for application as fluorescent nanoprobes in bioimaging. Moreover, we performed an in-depth study of photoluminescence dependence on pH and the phenomena of exciton-polaron quenching at low pH was highlighted. We also found that the ratio of emission intensity at 600 nm and 650 nm increased from 0.04 to 1.65 as pH was raised from 2.6 to 11.8, which could find its application in ratiometric pH sensing. FPNs exhibited excellent biocompatibility with >85 % cell viability for fibroblasts NIH/3 T3 and prostate cancer 22RV1 cells even at concentrations as high as 1000 µg/mL. In addition, fluorescence microscopy demonstrated concentration-dependent red fluorescence in the cytoplasm owing to the cellular uptake of FPNs in prostate cancer cells.

Biodiversity of meatborne Listeria spp. in Himachal Pradesh and their interaction with indigenous probiotics.

This study determined the anti-listerial activity of indigenous probiotics from traditional fermented foods of Western Himalaya against meat borne Listera monocytogens isolates from Himachal Pradesh. One hundred samples of meat and meat products like chicken (n = 25), chevon (goat meat, n = 20), fish (n = 20) and pork (n = 30) were collected and were analyzed for the presence of Listeria spp. by recommended culture and biochemical methods. L. monocytogens isolates were confirmed by PCR targeting the virulence gene hlyA (haemolysin A) and by16S rRNA sequencing. Anti-listerial activity of probiotic bacteria isolated from indigenous fermented foods of Himachal Pradesh was determined by well diffusion method using Lactobacillus rhamnosus GG (ATCC 53103) as the reference strain. Five percent of tested samples were found positive for L. monocytogens with incidence of 8.0% in chicken (2/25), 10.0% in fish (2/20) and 4.0% in chevon meat (1/25). None of the tested pork samples were found contaminated with L. monocytogenes. Among 11 indigenous probiotics used in this study, highest antagonistic activity was exhibited by Lactobacillus plantarum (ADF 10) and Enterococcus faecium (ADF1) which was equivalent to the reference strain.

Chemoprevention by Probiotics During 1,2-Dimethylhydrazine-Induced Colon Carcinogenesis in Rats.

BACKGROUND: Probiotics are believed to have properties that lower the risk of colon cancer. However, the mechanisms by which they exert their beneficial effects are relatively unknown. AIM: To assess the impact of probiotics in preventing induction of colon carcinogenesis in rats. METHODS: The rats were divided into six groups viz., normal control, Lactobacillus plantarum (AdF10)-treated, Lactobacillus rhamnosus GG (LGG)-treated, 1,2-dimethylhydrazine (DMH)-treated, L. plantarum (AdF10) + DMH-treated and L. rhamnosus GG (LGG) + DMH-treated. Both the probiotics were supplemented daily at a dose of 2 × 1010 cells per day. DMH at a dose of 30 mg/kg body weight was administered subcutaneously twice a week for the first 4 weeks and then once every week for a duration of 16 weeks. Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase as protein expression of genes involved in apoptosis were assessed during DMH-induced colon carcinogenesis in rats. RESULTS: DMH treatment decreased the activity of GSH, GPx, GST, SOD and catalase. However, AdF10 and LGG supplementation to DMH-treated rats significantly increased the activity of these enzymes. Further, DMH treatment revealed alterations in the protein expressions of various genes involved in the p53-mediated apoptotic pathway such as p53, p21, Bcl-2, Bax, caspase-9 and caspase-3, which, however, were shifted towards normal control levels upon simultaneous supplementation with probiotics. CONCLUSION: The present study suggests that probiotics can provide protection against oxidative stress and apoptotic-related protein disregulation during experimentally induced colon carcinogenesis.

Elucidation of biocontrol mechanisms of Trichoderma harzianum against different plant fungal pathogens: Universal yet host specific response.

In the present study, different transcripts of Trichoderma harzianum ThHP-3 were evaluated for their response against four fungal pathogens Fusarium oxysporum, Colletotrichum capsici, Colletotrichum truncatum and Gloesercospora sorghi using RT-qPCR. The time course study of T. harzianum transcripts related to signal transduction, lytic enzymes, secondary metabolites and various transporters revealed variation in expression against four fungal pathogens. In a broader term, the transcripts were upregulated at various time intervals but the optimum expression of cyp3, abc, nrp, tga1, pmk, ech42 and glh20 varied with respect to host fungi. Additionally, the expression of transcripts related to transporters/cytochromes was also observed against Fusarium oxysporum after 96h whereas transcripts related to secondary metabolites and lytic enzymes showed significant difference in expression against Colletotrichum spp. from 72 to 96h. This is first study on transcriptomic response of T. harzianum against pathogenic fungi which shows their host specific response.

Fermentation of Apple Juice with a Selected Yeast Strain Isolated from the Fermented Foods of Himalayan Regions and Its Organoleptic Properties.

Twenty-three Saccharomyces cerevisiae strains isolated from different fermented foods of Western Himalayas have been studied for strain level and functional diversity in our department. Among these 23 strains, 10 S. cerevisiae strains on the basis of variation in their brewing traits were selected to study their organoleptic effect at gene level by targeting ATF1 gene, which is responsible for ester synthesis during fermentation. Significant variation was observed in ATF1 gene sequences, suggesting differences in aroma and flavor of their brewing products. Apple is a predominant fruit in Himachal Pradesh and apple cider is one of the most popular drinks all around the world hence, it was chosen for sensory evaluation of six selected yeast strains. Organoleptic studies and sensory analysis suggested Sc21 and Sc01 as best indigenous strains for soft and hard cider, respectively, indicating their potential in enriching the local products with enhanced quality.

Molecular cloning and characterization of ech46 endochitinase from Trichoderma harzianum.

In the present study, endochitinase of T. harzianum isolate-ThHP3 induced against mycelium of F. oxysporum was cloned, sequenced and characterized. The complete nucleotide sequence contained an ORF of 1293bp corresponding to 430 amino acids with 46kDa molecular weight and theoretical pI 5.59. The precursor protein contained 22 amino acids long signal peptide at N terminus. The domain architecture of endochitinase showed low complexity regions, presence of 1W9P domain specific to cyclopentapeptide and lack of carbohydrate binding modules. The ligand binding site of ech46 endochitinase was constituted by 10 amino acids. The cDNA encoding ech46 endochitinase was ligated into pET28a vector and transformed to E. coli BL21. The predicted molecular weight of recombinant endochitinase without signal peptide was 49.4kDa with a theoretical pI 6.67. SDS-PAGE analysis of purified 6xHis tagged protein showed a single band of 49kDa. The refolded enzyme was active under acidic conditions with a temperature and pH optima of 50°C and 4. Km and Vmax for recombinant endochitinase using 4-pNP-(GlcNAc)3 were 315.2±0.36µM and 0.140±0.08µMmin-1, respectively and the calculated kcat was 6.44min-1. The RT-qPCR revealed induction of ech46 by phytopathogenic fungi.

Single piece artificial urinary sphincter for secondary incontinence following successful repair of post traumatic urethral injury.

Post traumatic urethral injury is uncommon in children. The management of this condition is dependent on the severity of injury. Initial suprapubic cystostomy with delayed repair is the conventional treatment. Successful reconstruction of urethral injury may be followed by urethral stricture, incontinence, impotence, and retrograde ejaculation. Successful repair of post traumatic urethral injury followed by secondary incontinence in children has not been well addressed in literature. We report the management of one such child, with satisfactory outcome with implantation of a new model of single piece artificial urinary sphincter in the bulbar urethra by perineal approach.

Influence of phenolic compounds of Kangra tea [Camellia sinensis (L) O Kuntze] on bacterial pathogens and indigenous bacterial probiotics of Western Himalayas

Phenolic compounds of nutraceutical importance viz., catechins (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) were estimated in fresh green tea shoots of Camellia sinensis (L) O Kuntze cultivar. The total polyphenols and total catechins were in the range of 219.90 to 317.81 and 140.83 to 271.39 g/kg, respectively in monthly samples of tea. The values of C, EC, EGC, EGCG and ECG in tea powders as analyzed through high performance liquid chromatography (HPLC) were in the range of 1.560 to 3.661, 13.338 to 27.766, 26.515 to 39.597, 62.903 to 102.168 and 18.969 to 39.469 mg/g, respectively. Effect of tea extracts and standard flavanols against five pathogenic bacteria viz., Listeria monocytogenes (MTCC-839), Pseudomonas aeruginosa (MTCC-741), Bacillus cereus (MTCC-1272), Staphylococcus aureus (MTCC-96) and Escherichia coli (MTCC-443), and eleven indigenous potential bacterial probiotics belonging to genera Enterococcus, Bacillus and Lactobacillus spp. obtained from fermented foods of Western Himalayas, was investigated. EGCG, ECG and EGC exhibited antibacterial activity but, C and EC did not show this activity. Tea extracts having high concentrations of EGCG and ECG were more potent in antibacterial action against bacterial pathogens. Tea extracts and standard flavan-3-ols augmented viability of potential probiotics in an order of EGCG > EGC > ECG > EC > C. Tea extracts and standard flavanols had no antibacterial activity against Escherichia coli (MTCC-443) but, in combination with probiotic culture supernatants, this activity was seen. The Kangra tea thus, exerts antibacterial effect on bacterial pathogens through EGCG, ECG and EGC constituents while stimulatory effect on growth of indigenous potential probiotics.

Influence of phenolic compounds of Kangra tea [Camellia sinensis (L) O Kuntze] on bacterial pathogens and indigenous bacterial probiotics of Western Himalayas.

Phenolic compounds of nutraceutical importance viz., catechins (C), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) were estimated in fresh green tea shoots of Camellia sinensis (L) O Kuntze cultivar. The total polyphenols and total catechins were in the range of 219.90 to 317.81 and 140.83 to 271.39 g/kg, respectively in monthly samples of tea. The values of C, EC, EGC, EGCG and ECG in tea powders as analyzed through high performance liquid chromatography (HPLC) were in the range of 1.560 to 3.661, 13.338 to 27.766, 26.515 to 39.597, 62.903 to 102.168 and 18.969 to 39.469 mg/g, respectively. Effect of tea extracts and standard flavanols against five pathogenic bacteria viz., Listeria monocytogenes (MTCC-839), Pseudomonas aeruginosa (MTCC-741), Bacillus cereus (MTCC-1272), Staphylococcus aureus (MTCC-96) and Escherichia coli (MTCC-443), and eleven indigenous potential bacterial probiotics belonging to genera Enterococcus, Bacillus and Lactobacillus spp. obtained from fermented foods of Western Himalayas, was investigated. EGCG, ECG and EGC exhibited antibacterial activity but, C and EC did not show this activity. Tea extracts having high concentrations of EGCG and ECG were more potent in antibacterial action against bacterial pathogens. Tea extracts and standard flavan-3-ols augmented viability of potential probiotics in an order of EGCG > EGC > ECG > EC > C. Tea extracts and standard flavanols had no antibacterial activity against Escherichia coli (MTCC-443) but, in combination with probiotic culture supernatants, this activity was seen. The Kangra tea thus, exerts antibacterial effect on bacterial pathogens through EGCG, ECG and EGC constituents while stimulatory effect on growth of indigenous potential probiotics.

Plastic-syringe induced silicone contamination in organic photovoltaic fabrication: implications for small-volume additives.

Herein, the implications of silicone contamination found in solution-processed conjugated polymer solar cells are explored. Similar to a previous work based on molecular cells, we find this contamination as a result of the use of plastic syringes during fabrication. However, in contrast to the molecular case, we find that glass-syringe fabricated devices give superior performance than plastic-syringe fabricated devices in poly(3-hexylthiophene)-based cells. We find that the unintentional silicone addition alters the solution's wettability, which translates to a thinner, less absorbent film on spinning. With many groups studying the effects of small-volume additives, this work should be closely considered as many of these additives may also directly alter the solutions' wettability, or the amount of silicone dissolved off the plastic syringes, or both. Thereby, film thickness, which generally is not reported in detail, can vary significantly from device to device.

Altered membrane lipid dynamics and chemoprevention by non-steroidal anti inflammatory drugs during colon carcinogenesis.

The present work focuses on the anti-neoplastic role of non steroidal anti-inflammatory drugs (NSAIDs) in modulating the biophysical parameters of the colonic membranes in 1,2-dimethylhydrazine dihydrochloride (DMH) induced carcinogenesis. The steady-state fluorescence polarization technique was applied to assess membrane fluidity, membrane polarity and lipid phase states. The decline in cholesterol content, biosynthesis and cholesterol: phospholipids ratio with DMH treatment indicates more fluidity associated with carcinogenesis. The DMH group had shown lower order parameter indicating more fluidity whereas NSAIDs resulted in increasing the membrane lipid order. The converging effects of these changes were more in membrane phase separations and membrane phase state. In DMH treatment membrane shows lesser phase separation or high polarity, and more liquid crystalline state while for NSAID groups membranes have higher phase separations or low polarity, and more of the gel phase. Further, NSAIDs induced anti-proliferative effects were evidently observed by apoptosis in the colonocytes by using acridine orange-ethidium bromide fluorescent staining and Terminal de-oxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The results suggest that NSAIDs induced alteration in the membrane biophysical parameters may be an important initiating event for the chemopreventive action.

Altered membrane lipid dynamics and chemoprevention by non-steroidal anti inflammatory drugs during colon carcinogenesis / Alteración de la dinámica de los lípidos de membrana y quimioprevención mediante los fármacos antiinflamatorios no esteroideos en la carcinogénesis de colon

The present work focuses on the anti-neoplastic role of non steroidal anti-inflammatory drugs (NSAIDs) in modulating the biophysical parameters of the colonic membranes in 1,2-dimethylhydrazine dihydrochloride (DMH) induced carcinogenesis. The steady-state fluorescence polarization technique was applied to assess membrane fluidity, membrane polarity and lipid phase states. The decline in cholesterol content, biosynthesis and cholesterol: phospholipids ratio with DMH treatment indicates more fluidity associated with carcinogenesis. The DMH group had shown lower order parameter indicating more fluidity whereas NSAIDs resulted in increasing the membrane lipid order. The converging effects of these changes were more in membrane phase separations and membrane phase state. In DMH treatment membrane shows lesser phase separation or high polarity, and more liquid crystalline state while for NSAID groups membranes have higher phase separations or low polarity, and more of the gel phase. Further, NSAIDs induced anti-proliferative effects were evidently observed by apoptosis in the colonocytes by using acridine orange-ethidium bromide fluorescent staining and Terminal de-oxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The results suggest that NSAIDs induced alteration in the membrane biophysical parameters may be an important initiating event for the chemopreventive action (AU)

Este trabajo se centra en el papel antineoplásico de los fármacos antiinflamatorios no esteroideos (AINE) en la modulación de los parámetros biofísicos de las membranas colónicas en la carcinogénesis inducida por 1,2-dihidrocloruro de dimetilhidracina (DMH). Se aplicó la técnica de polarización de la fluorescencia en estado de equilibrio para evaluar la fluidez de la membrana, su polaridad y los estados de fase lipídica. El declive del contenido de colesterol, la biosíntesis y el cociente colesterol: fosfolípidos con el tratamiento con DMH indica más fluidez asociada con la carcinogénesis. El grupo DMH mostraba un parámetro de menor orden, lo que indica más fluidez, mientras que los AINE produjeron un aumento del orden de lípidos de membrana. Los efectos convergentes de estos cambios fueron más notables en las separaciones de la fase de membrana y en el estado de fase de membrana. Con el tratamiento con DMH, la membrana muestra menor separación de fase o polaridad elevada, y un estado cristalino más líquido o polaridad elevada mientras que los grupos de AINE tienen mayores separaciones de membrana o polaridad baja y más fase en estado gel. Además, los efectos antiproliferativos inducidos por los AINE se observaron de forma evidente utilizando tinción fluorescente con naranja de acridinabromuro de etidio y el ensayo de marcado final de la dUTP transferasa desoxinucleotidil terminal (TUNEL). Los resultados sugieren que los AINE inducían una alteración de los parámetros biofísicos de la membrana, lo cual podría ser un acontecimiento inicial importante para la acción quimiopreventiva (AU)

Gastric outlet obstruction caused by a pyloric submucosal fibroepithelial tumour.

A 57 year old male patient presented to our hospital with vomiting, epigastric discomfort, and loss of appetite over a 24hr period. Subsequent investigations demonstrated a submucosal lesion causing gastric outlet obstruction. The patients deteriorating condition mandated laparotomy and a pathologic diagnosis was made of a pyloric submucosal fibroepithelial lesion from the resected distal stomach and adherent transverse colon; no malignant features were found. This is to our knowledge the first instance of a fibroepithelial neoplasm occurring within the gastrointestinal tract.

24-hour rhythm to the onset of term and preterm labour in twin pregnancies.

The objective of this study is to describe the time of onset of contractions in twin pregnancies that result in delivery, so as to investigate whether there is a diurnal influence. A UK maternity department database was used to identify twin deliveries over a 5-year period, and the time of onset of labour was retrieved from these records. Two hundred and eleven women with spontaneous onset of labour in twin pregnancies were studied. A significant diurnal rhythm in the timing of contractions was noted, with 45% of deliveries occurring in labour that commenced between midnight and 08.00 hours. This periodicity is similar for twin pregnancies that end in preterm (24-36 weeks of gestation; χ² = 17.2; P < 0.01) or term deliveries (37-40 weeks of gestation; χ² = 13; P < 0.05). The periodicity of onset of labour in multiple pregnancies demonstrates a similar rhythm to singleton pregnancies, where labour most commonly begins between midnight and 08.00 hours.

Purification and characterization of a low molecular mass alkaliphilic lipase of Bacillus cereus MTCC 8372.

A low molecular mass alkaliphilic extra-cellular lipase of Bacillus cereus MTCC 8372 was purified 35-fold by hydrophobic interaction (Octyl-Sepharose) chromatography. The purified enzyme was found to be electrophoretically pure by denaturing gel electrophoresis and possessed a molecular mass of approximately 8 kDa. It is a homopentamer of 40 kDa as revealed by native-PAGE. The lipase was optimally active at 55 °C and retained approximately half of its original activity after 40 min incubation at 55 °C. The enzyme was maximally active at pH 8.5. Mg2+, Cu2+, Ca2+, Hg2+, Al3+ and Fe3+ at 1 mM enhanced hydrolytic activity of the lipase. Interestingly, Hg2+ ions synergized and Zn2+ and Co2+ ions antagonized the lipase activity. Among surfactants, Tween 80 promoted the lipase activity. Phenyl methyl sulfonyl fluoride (PMSF, 15 mM) decreased 98% of original activity of lipase. The lipase was highly specific towards p-nitrophenyl palmitate and showed a Vmax and Km of 0.70 mmol.mg⁻¹.min⁻¹ and 32 mM for hydrolysis of pNPP.

Polythiophene-fullerene based photodetectors: tuning of spectral response and application in photoluminescence based (bio)chemical sensors.

A photoluminescence (PL)-based oxygen and glucose sensor utilizing inorganic or organic light emitting diode as the light source, and polythiophene: fullerene type bulk-heterojunction devices as photodetectors, for both intensity and decay-time based monitoring of the sensing element's PL. The sensing element is based on the oxygen-sensitive dye Pt-octaethylporphyrin embedded in a polystyrene matrix.

Design of light-trapping microscale-textured surfaces for efficient organic solar cells.

Organic photovoltaic (OPV) cells suffer from low charge carrier mobilities of polymers, which renders it important to achieve complete optical absorption in active layers thinner than optical absorption length. Active layers conformally deposited on light-trapping, microscale textured, grating-type surfaces is one possible approach to achieve this objective. In this report, we analyze the design of such grating-type OPV cells using finite element method simulations. The energy dissipation of electromagnetic field in the active layer is studied as a function of active layer thickness, and pitch and height of the underlying textures. The superiority of textured geometry in terms of light trapping is clearly demonstrated by the simulation results. We observe 40% increase in photonic absorption in 150 nm thick active layer, for textures with 2 microm pitch and 1.5 microm height.