Impact of oxidative and osmotic stresses on Candida albicans biofilm formation

Candida albicans possesses an ability to grow under different host-driven stress conditions by developing robust protective mechanisms. In this investigation the focus was on the impact of osmotic (2M NaCl) and oxidative (5 mM H2O2) stress conditions during C. albicans biofilm formation. Oxidative stress enhanced extracellular DNA secretion into the biofilm matrix, increased the chitin level, and reduced virulence factors, namely phospholipase and proteinase activity, while osmotic stress mainly increased extracellular proteinase and decreased phospholipase activity. Fourier transform infrared and nuclear magnetic resonance spectroscopy analysis of mannan isolated from the C. albicans biofilm cell wall revealed a decrease in mannan content and reduced β-linked mannose moieties under stress conditions. The results demonstrate that C. albicans adapts to oxidative and osmotic stress conditions by inducing biofilm formation with a rich exopolymeric matrix, modulating virulence factors as well as the cell wall composition for its survival in different host niches.

Valence fluctuation and magnetic ordering in EuNi2(P(1-x)Ge(x))2 single crystals

Unusual phases and phase transitions are seen at the magnetic-nonmagnetic boundary in Ce-, Eu- and Yb-based compounds. EuNi2P2 is a very unusual valence fluctuating Eu system, because at low temperatures the Eu valence stays close to 2.5 instead of approaching an integer value. The Eu valence, and thus the magnetic property in this system, can be tuned by Ge substitution in the P site as EuNi2Ge2 is known to exhibit the antiferromagnetc (AFM) ordering of divalent Eu moments with T(N)=30K. We have grown EuNi2(P(1-x)Ge(x))2 (0.0≤ x ≤0.5)) single crystals and studied their magnetic, thermodynamic and transport properties. Increasing Ge doping to x  >  0.4 results in a well-defined AFM ordered state with T(N)=12K for x  =  0.5. Moreover, the reduced value of magnetic entropy for x  =  0.5 at T(N) suggests the presence of valance fluctuation/the Kondo effect in this compound. Interestingly, the specific heat exhibits an enhanced Sommerfeld coefficient upon Ge doping. Subsequently, electronic structure calculations lead to a non-integral valence in EuNi2P2 but a stable divalent Eu state in EuNi2Ge2, which is in good agreement with the experimental results.

Modulation of Candida albicans Biofilm by Different Carbon Sources

In the present investigation, the role of carbon sources (glucose, lactate, sucrose, and arabinose) on Candida albicans biofilm development and virulence factors was studied on polystyrene microtiter plates. Besides this, structural changes in cell wall component β-glucan in presence of different carbon sources have also been highlighted. Biofilm formation was analyzed by XTT (2,3-bis[2-Methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay. Glucose-grown cells exhibited the highest metabolic activity during adhesion among all carbon sources tested (p < 0.05). However, cells exposed to sucrose exhibited highest biofilm formation and matrix polysaccharides secretion after 48 h. The results also correlated with the biofilm height and roughness measurements by atomic force microscopy. Exposure to lactate induced hyphal structures with the highest proteinase activity while arabinose-grown cells formed pseudohyphal structures possessing the highest phospholipase activity. Structural changes in β-glucan characterized by Fourier transform infrared (FTIR) spectroscopy displayed characteristic band of β-glucan at 892 cm(-1) in all carbon sources tested. The β(1→6) to β(1→3) glucan ratio calculated as per the band area of the peak was less in lactate (1.15) as compared to glucose (1.73), sucrose (1.62), and arabinose (2.85). These results signify that carbon sources influence C. albicans biofilm development and modulate virulence factors and structural organization of cell wall component β-glucan.

Transfer of useful variability of high grain iron and zinc from Aegilops kotschyi into wheat through seed irradiation approach

PURPOSE

To transfer the 2S chromosomal fragment(s) of Aegilops kotschyi (2S(k)) into the bread wheat genome which could lead to the biofortification of wheat with high grain iron and zinc content.

MATERIALS AND METHODS

Wheat-Ae. kotschyi 2A/2S(k) substitution lines with high grain iron and zinc content were used to transfer the gene/loci for high grain Fe and Zn content into wheat using seed irradiation approach.

RESULTS

Bread wheat plants derived from 40 krad-irradiated seeds showed the presence of univalents and multivalents during meiotic metaphase-I. Genomic in situ hybridization analysis of seed irradiation hybrid F2 seedlings showed several terminal and interstitial signals indicated the introgression of Ae. kotschyi chromosome segments. This proves the efficacy of seed radiation hybrid approach in gene transfer experiments. All the radiation-treated hybrid plants with high grain Fe and Zn content were analyzed with wheat group 2 chromosome-specific polymorphic simple sequence repeat markers to identify the introgression of small alien chromosome fragment(s).

CONCLUSION

Radiation-induced hybrids showed more than 65% increase in grain iron and 54% increase in Zn contents with better harvest index than the elite wheat cultivar WL711 indicating effective and compensating translocations of 2S(k) fragments into wheat genome.

New source of MeV negative ion and neutral atom beams

The scenario of "electron-capture and -loss" was recently proposed for the formation of negative ion and neutral atom beams with MeV kinetic energies. However, it does not explain why the formation of negative ions in a liquid spray is much more efficient than with an isolated atom. The role of atomic excited states in the charge-exchange processes is considered, and it is shown that it cannot account for the observed phenomena. The processes are more complex than the single electron-capture and -loss approach. It is suggested that the shell effects in the electronic structure of the projectile ion and/or target atoms may influence the capture/loss probabilities.

Exploring the origin of the catalytic power and product specificity of SET domain protein methyltransferase

Computer simulation reveals that the origin of SET8 catalytic power is mainly due to electrostatic preorganization.

An overview on dry reforming of methane: strategies to reduce carbonaceous deactivation of catalysts

Catalytic reforming of methane (CH₄) with carbon dioxide (CO₂), known as dry reforming of methane (DRM), produces synthesis gas, which is a mixture of hydrogen (H₂) and carbon monoxide (CO).

Nickel-oxide multiwall carbon-nanotube/reduced graphene oxide a ternary composite for enzyme-free glucose sensing

We report a solvent-free method of preparation for a NiO–carbon nanotube/graphene ternary composite using nickel formate as a green precursor via a thermal decomposition method.

Changes in preterm human milk composition with particular reference to introduction of mixed feeding

OBJECTIVE

To study the changes in composition of preterm milk till 6 months of age.

METHODS

Milk samples from 33, 19, 7 and 12 lactating mothers (delivered <34 weeks) were analyzed on days 7, 28, 90 and 180, respectively.

RESULTS

Triglyceride and sodium concentrations increased significantly with time and protein concentration decreased significantly over 180 days. Sodium (P=0.02) and triglyceride concentrations (P=0.06) were higher in milk samples of mothers who had introduced mixed feeding by 6 months post natal age (n=6) compared to exclusively breast-feeding mothers (n=6); but lactose and protein content was not significantly different.

CONCLUSIONS

Milk of preterm mothers has higher amount of triglycerides and sodium during introduction of mixed feeding.

Clinico-pathological Profile of Bronchogenic Carcinoma Among Females in North India

OBJECTIVE

The present study was undertaken to explore the clinico-pathological profile of bronchogenic carcinoma among females.

METHODS

One hundred and twenty-four female patients with histopathologically proven bronchogenic carcinoma who were hospitalised in the Department of Pulmonary Medicine, King George's Medical University, Lucknow from July 1985 to February 2007 were retrospectively studied.

RESULTS

Their mean age was 61 years; 12.9% of these were less than 40 years of age. Of these, 79% of female patients of lung cancer were first regarded as pulmonary tuberculosis; 76% belonged to rural area. Use of biomass fuel and kerosene oil exposure was the predominant risk factors evident among the 116 non-smoker women. Adenocarcinoma was observed in 43.5%, followed by squamous cell carcinoma in 33.1% and the remaining 23.4% cases were small cell carcinoma. The majority (77.4%) of non-small cell lung cancer (NSCLC) patients had advanced stage disease (I]Ib and IV) and 58% of small cell lung cancer (SCLC) patients had limited disease and 42% of SCLC patients had extensive disease at the time of diagnosis.

CONCLUSION

Adenocarcinoma was found to be the most common histopathological type of bronchogenic carcinoma among these females.

Heterogeneity of the growth phenotype and birth size in acid-labile subunit (ALS) deficiency

PURPOSE

The IGFALS gene encodes the acid-labile subunit (ALS) protein, which regulates circulating IGF-1. Human IGFALS mutations cause growth hormone insensitivity (GHI) associated with ALS, IGF-1 and IGFBP-3 deficiencies and mild to moderate postnatal growth impairment (height SDS -2 to -4). Prenatal growth impairment is not a recognised feature of this disorder, but heterozygous carriers may show an intermediate phenotype.

METHODS

We report a family of five subjects, including three children born small for gestational age, who were investigated for IGFALS gene mutations.

RESULTS

The proband, an 8.7 years female with pre- and postnatal growth failure (BW SDS -3.04, Ht SDS -3.86) and biochemical features of GHI, had a homozygous mutation of IGFALS, c.401T>A; p.L134Q. Her 6.1 years brother (BW SDS -2.11, Ht SDS -2.0) had the same homozygous IGFALS mutation. Both parents [adult height SDS -1.76 (father) and -1.82 (mother)] and her 2.7 years sister (BW SDS -2.60, Ht SDS -2.04) were heterozygous for the IGFALS mutation.

CONCLUSION

Significant phenotypic heterogeneity was observed between family members, in particular varying degrees of prenatal growth retardation were present in the three siblings, which may have contributed to the variation in the postnatal growth phenotype.

A multicenter prospective hospital-based surveillance to estimate the burden of rotavirus gastroenteritis in children less than five years of age in India

BACKGROUND

Rotavirus is the leading cause of severe, dehydrating diarrhea in children aged <5 years globally, with an estimated 25 million outpatient visits and 2 million hospitalizations attributable to rotavirus infections each year. The aim of this hospital-based surveillance was to summarize the local epidemiological and virological features of rotavirus and to estimate the disease burden in the population under surveillance in India.

METHODS

During the 16 months surveillance period from April 2011 through July 2012, a total of 4711 children under the age of 5 years were admitted with acute diarrhea at 12 medical centers attached to medical schools throughout India. Stool samples were randomly collected from 2051 (43.5%) subjects and were analyzed for rotavirus positivity using commercial enzyme immunoassay kit (Premier Rotaclone Qualitative Elisa) at the respective study centers. Rotavirus positive samples were genotyped for VP7 and VP4 by reverse-transcription polymerase chain reaction (RT-PCR) at a central laboratory.

RESULTS

During the study period, maximum number of rotavirus related hospitalizations were reported from December 2011 through February 2012. Out of the 2051 stool samples tested for rotavirus, overall 541 (26.4%) samples were positive for rotavirus VP6 antigen in stool. The highest positivity was observed in the month of December, 2011 (52.5%) and lowest in the month of May, 2011 (10.3%). We found that majority of the rotavirus positive cases (69.7%) were in children <24 months of age. The most common genotypes reported were G1 (38%), G2 (18%), G9 (18%), G12 (9%) and mixed strains (17%).

CONCLUSIONS

The results of this study confirm the significant burden of acute rotavirus gastroenteritis as a cause of hospitalizations in under five children in India.

Retrospective surveillance for intussusception in children aged less than five years at two tertiary care centers in India

BACKGROUND

A rotavirus vaccine could soon become part of India's national immunization program. However the occurrence of intussusception due to rotavirus vaccine is a potential safety concern. This surveillance aimed at the collection of baseline data on childhood intussusception which would facilitate the monitoring of intussusception cases after the introduction of rotavirus vaccines.

METHODS

We retrospectively reviewed medical records of confirmed intussusception cases in children under the age of five, treated during 2007-2012 at two tertiary care hospitals attached to medical schools in India. Demographic, clinical, diagnostic and treatment practices data were obtained from hospital records.

RESULTS

Over a five to six year observation period, we identified 187 confirmed cases of intussusception, of which 75% were males. The median age of intussusception was 8 months, and we observed a possible trend in the distribution of cases with the highest number of cases being reported in the month of April and lowest in the month of October. The most common diagnostic methods used were ultrasonography and abdominal radiography with most cases being treated surgically (71%). The median length of hospital stay was 8 days (range 1-40) and mean was 10.2 days. Records of any fatality due to intussusception were not found during the review of the records.

CONCLUSIONS

This analysis provides an estimate of the baseline data of childhood intussusception prior to the introduction of the rotavirus vaccination as a part of routine immunization in India. A prospective surveillance system using a standardized case definition is needed in order to better examine the incidence of intussusception in developing countries.

Interface mediated semiconducting to metallic like transition in ultrathin Bi2Se3 films on (100) SrTiO3 grown by molecular beam epitaxy

Compressive strains due to the structural phase transition of SrTiO₃ substrate facilitate semiconductor to metal like transition in Bi₂Se₃ thin films.