An ultra sensitive saccharides detection assay using carboxyl functionalized chitosan containing : nanoparticlesprobe

A novel saccharides detection assay based on covalent immobilization of amino phenyl boronic acid (APBA) in thin films of carboxyl functionalized chitosan (HOOC-chitosan) containing <5 nm Gd2O3 : Eu3+ nanoparticles at a platinum disc electrode was developed. The resulting HOOC-chitosan/Gd2O3 : Eu3+ nanocomposite film exhibited excellent electrochemical response to changes in the pKa values of boronate esters yielded from different vicinal diols of sugars. The covalent interaction of APBA onto the HOOC-chitosan/Gd2O3 : Eu3+ Pt-disc electrode was characterized with FT-IR, SEM, contact angle and cyclic voltammetry, whereas Gd2O3 : Eu3+ nanoparticles and HOOC-chitosan/Gd2O3 : Eu3+ nanocomposite was identified using XRD, EDX and TEM. A wide linear response was measured to boronate esters ranging from 25 nM to 13.5 μM (r2 = 0.963) with good reproducibility. The excellent electrochemical activity of the assay might be attributed to the synergistic effects of the balanced de-/protonated HOOC-chitosan, APBA and Gd2O3 : Eu3+ nanoparticles. With APBA as a model, the HOOC-chitosan/Gd2O3 : Eu3+ nanocomposite-modified Pt-electrode was constructed through a simple drop coating method. The resulting assay exhibited a good potentiometric response to different saccharides including glucose, and could be a promising application for the precise electrochemical detection of vicinal diols of specific sugars for clinical diagnostics, medicine validation, bioscience research and food analysis.

Electron arc therapy for bilateral chest wall irradiation: treatment planning and dosimetric study

AIMS

The treatment of patients with synchronous bilateral breast cancer is a challenge. We present a report of dosimetric data of patients with bilateral chest walls as the target treated with electron arc therapy.

MATERIALS AND METHODS

Ten consecutive patients who had undergone electron arc therapy to the bilateral chest wall for breast cancer were analysed. After positioning and immobilisation, patients underwent computed tomography scans from the neck to the upper abdomen. Electron arc plans were generated using the PLATO RTS (V1.8.2 Nucletron) treatment planning system. Electron energy was chosen depending upon the depth and thickness of the planning target volume (PTV). For all patients, the arc angle ranged between 80 and 280° (start angle 80°, stop angle 280°). The homogeneity index, coverage index and doses to organs at risk were evaluated. The patient-specific output factor and thermoluminescence dosimetry (TLD) measurements were carried out for all patients. The total planned dose to the PTV was 50Gy/25 fractions/5 weeks.

RESULTS

The mean PTV (± standard deviation) was 568.9 (±116)cm(3). The mean PTV coverage was 89 (±5.8)% of the prescribed dose. For the right lung, the mean values of D(1) and D(10) were 46 (±7.6) and 30 (±9)Gy, respectively. For the left lung, the mean values of D(1) and D(10) were 45 (±7) and 27 (±8)Gy, respectively. For the heart, the mean values of D(1), D(5) and D(10) were 21 (±15), 13.5 (±12) and 9 (±9)Gy, respectively. The mean values of TLD at various pre-specified locations on the chest wall surface were 1.84, 1.82, 1.82, 1.89 and 1.78Gy, respectively

CONCLUSION

The electron arc technique for treating the bilateral chest wall is a feasible and pragmatic technique. This technique has the twin advantages of adequate coverage of the target volume and sparing of adjacent normal structures. However, compared with other techniques, it needs a firm quality assurance protocol for dosimetry and treatment delivery.

Establishment of lacZ marked strain of phosphate solubilizing bacterium in the rhizosphere and its effect on plant growth in mungbean

The establishment of lacZ marked strain of P-solubilizing bacterium Pseudomonas in the rhizosphere of mungbean (Vigna radiata) under pothouse conditions was studied. The lacZ marker was transferred to Pseudomonas P-36 on LB medium using donor strain of E. coli. The lacZ marked strain formed blue colonies on selective media and could be identified from soil on the basis of this character. The lacZ marked strain was able to survive in rhizosphere of mungbean under pothouse conditions and maintained a population of about 10(4) g(-1) of rhizosphere soils up to 60 days study period. Positive effect of inoculation with P-solubilizing bacterium on dry matter yield, P and N-uptake was observed using rock phosphate and single super phosphate as P sources with and without farmyard amendment.

Size dependence of Eu-O charge transfer process on luminescence characteristics of YBO3:Eu3+ nanocrystals

Well-crystallized pure hexagonal phase YBO(3):Eu(3+) nanoparticles are prepared by the reverse micelles method. Vacuum ultraviolet photoluminescence (VUVPL) spectroscopy showed size-dependent nonlinear luminescence enhancement with remarkably improved chromaticity (0.62, 0.34), as compared to the commercial bulk YBO(3):Eu(3+) phosphor (0.56, 0.39). The quenching concentration of Eu(3+) doping and the ratio of red ((5)D(0)-->(7)F(2)) to orange ((5)D(0)-->(7)F(1)) emission was found significantly enhanced with the decrease in particle size, making it an ideal VUV phosphor for plasma display panels. The possible explanation for size dependence of the Eu-O charge transfer process via lowering of the structural symmetry is proposed in detail.

Novel analysis of bacterium-substratum bond maturation measured using a quartz crystal microbalance

Studies in flow displacement systems have shown that the reversibility of bacterial adhesion decreases within seconds to minutes after initial contact of a bacterium with a substratum surface. Atomic force microscopy (AFM) has confirmed that the forces mediating bacterial adhesion increase over a similar time span. The interfacial rearrangements between adhering bacteria and substratum surfaces responsible for this bond maturation have never been studied. Quartz crystal microbalance with dissipation (QCM-D) senses the interfacial region in real time and nondisruptively up to 250 nm from the sensor surface. In this paper, QCM-D is combined with real-time observation of bacterial adhesion in a flow displacement system, in order to analyze resident-time-dependent changes in dissipation. Three different Streptococcus salivarius strains showed a nonlinear relation between total dissipation shift (DeltaD) and number of adhering bacteria, whereas inert and rigid silica particles demonstrated a linear relation between DeltaD and the number of adhering particles. This suggests removal of interfacial water due to residence time dependent deformation of the nonrigid bacterium-substratum interface during bond maturation. Dissipation could be described by an exponentially decaying function, which combined with adhesion data allowed extraction of the dissipation shifts per bacterium upon initial contact (DeltaD(0)), after bond maturation (DeltaD(infinity)), as well as a characteristic time constant (tau(bm)). All bacterial strains showed significant bond maturation within one minute after their arrival at the substratum surface, which was not observed for silica particles. Dissipation analysis at the level of individually adhering bacteria would have been impossible without the simultaneous real-time analysis of bacterial adhesion numbers.

Isolation and Characterization of a Facultatively Aerobic Bacterium That Reductively Dehalogenates Tetrachloroethene to cis-1,2-Dichloroethene

A rapidly-growing facultatively aerobic bacterium that transforms tetrachloroethene (PCE) via trichloroethene (TCE) to cis-1,2-dichloroethene (cis-1,2-DCE) at high rates in a defined medium was isolated from a contaminated site. Metabolic characterization, cellular fatty acid analysis, and partial sequence analysis of 16S rRNA showed that the new isolate, strain MS-1, has characteristics matching those of the members of the family Enterobacteriaceae. Strain MS-1 can oxidize about 58 substrates including many carbohydrates, short-chain fatty acids, amino acids, purines, and pyrimidines. It can transform up to 1 mM PCE (aqueous) at a rate of about 0.5 (mu)mol of PCE(middot) h(sup-1)(middot)mg (dry weight) of cell(sup-1). PCE transformation occurs following growth on or with the addition of single carbon sources such as glucose, pyruvate, formate, lactate, or acetate or with complex nutrient sources such as yeast extract or a mixture of amino acids. PCE dehalogenation requires the absence of oxygen, nitrate, and high concentrations of fermentable compounds such as glucose. Enterobacter agglomerans biogroup 5 (ATCC 27993), a known facultative bacterium that is closely related to strain MS-1, also reductively dehalogenated PCE to cis-1,2-DCE. To our knowledge, this is the first report on isolation of a facultative bacterium that can reductively transform PCE to cis-1,2-DCE under defined physiological conditions. Also, this is the first report of the ability of E. agglomerans to dehalogenate PCE.

Olmsted syndrome

Olmsted syndrome is a rare disorder characterized by the combination of periorificial, keratotic plaques and bilateral palmoplantar keratoderma. New associated features are being reported. Olmsted syndrome is particularly rare in a female patient, and we report such a case in a six year-old Indian girl, who presented with keratoderma of her soles since birth and on her palms since the age of two years along with perioral and perinasal hyperkeratosis. She had sparse, light brown, thin hair. Although the psychomotor development of the child was normal until 18 months of age, the keratoderma plaques had restricted the child's mobility after that stage.

I.2. Mechanics of materials

Mechanics of materials is the science of forces applied on a body and response of the body in terms of deformation. Different type of loadings on bodies with different geometries or made of different material give rise to different deformations. Last but not the least, this science allows to predict the failure of a body under certain loading condition hence makes it possible to optimize the design for that particular condition.

The potential for bio-optical imaging of biomaterial-associated infection in vivo

This review presents the current state of Bioluminescence and Fluorescent Imaging technologies (BLI and FLI) as applied to Biomaterial-Associated Infections (BAI). BLI offers the opportunity to observe the in vivo course of BAI in small animals without the need to sacrifice animals at different time points after the onset of infection. BLI is highly dependent on the bacterial cell metabolism which makes BLI a strong reporter of viable bacterial presence. Fluorescent sources are generally more stable than bioluminescent ones and specifically targeted, which renders the combination of BLI and FLI a promising tool for imaging BAI. The sensitivity and spatial resolution of both imaging tools are, however, dependent on the imaging system used and the tissue characteristics, which makes the interpretation of images, in terms of the location and shape of the illuminating source, difficult. Tomographic reconstruction of the luminescent source is possible in the most modern instruments, enabling exact localization of a colonized implant material, spreading of infecting organisms in surrounding tissue and immunological tissue reactions. BLI studies on BAI have successfully distinguished between different biomaterials with respect to the development and clearance of BAI in vivo, simultaneously reducing animal use and experimental variation. It is anticipated that bio-optical imaging will become an indispensable technology for the in vivo evaluation of antimicrobial coatings.

Role of interfacial tensions in the translocation of Rhodococcus erythropolis during growth in a two phase culture

Rhodococcus erythropolis PR4 is an alkane-degrading bacterium, which grows well in media containing high concentrations of alkanes. These properties give the organism potential in the bioremediation of various environments contaminated by alkanes. In this study, we report the translocation of R. erythropolis PR4 from an aqueous phase to an alkane phase during growth in a two phase culture medium. When the alkane chain length was between C10 and C12, PR4 was located at the aqueous-alkane interface, but when the alkane chain length was above C14, PR4 translocated into the alkane phase. Complete translocation into alkane phase was accompanied by normal growth, whereas interfacial localization hampered growth, indicating that localization among other possible factors, play an important role in the growth of R. erythropolis PR4 in two phase cultures. The PR4 cell surface was physico-chemically characterized in terms of its cell surface charge and surface free energy. Contact angles were measured on bacterial lawns, followed by thermodynamic analyses of Gibbs free energies for localization of PR4 in the aqueous or alkane phase or at the interface. Although entry into the alkane phase of PR4 grown in the presence of both C12 and C19 was thermodynamically favorable, translocation from the inside of the alkane phase to the interface was only favorable for PR4 grown in the presence of C12. In line with these thermodynamic analyses, two phase partitioning showed that PR4 grown in the presence of C12 and C19 were more hydrophobic than PR4 grown in the presence of lower alkanes, while C12 grown bacteria were less lipophilic than C19 grown bacteria. In conclusion, the localization of R. erythropolis PR4 in a two phase culture medium is thermodynamically driven to facilitate its optimal growth.

Tunable Visible Emission of Ag-Doped CdZnS Alloy Quantum Dots

Highly luminescent Ag-ion-doped Cd1-xZnxS (0 ≤ x ≤ 1) alloy nanocrystals were successfully synthesized by a novel wet chemical precipitation method. Influence of dopant concentration and the Zn/Cd stoichiometric variations in doped alloy nanocrystals have been investigated. The samples were characterized by X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) to investigate the size and structure of the as prepared nanocrystals. A shift in LO phonon modes from micro-Raman investigations and the elemental analysis from the energy dispersive X-ray analysis (EDAX) confirms the stoichiometry of the final product. The average crystallite size was found increasing from 1.0 to 1.4 nm with gradual increase in Ag doping. It was observed that photoluminescence (PL) intensity corresponding to Ag impurity (570 nm), relative to the other two bands 480 and 520 nm that originates due to native defects, enhanced and showed slight red shift with increasing silver doping. In addition, decrease in the band gap energy of the doped nanocrystals indicates that the introduction of dopant ion in the host material influence the particle size of the nanocrystals. The composition dependent bandgap engineering in CdZnS:Ag was achieved to attain the deliberate color tunability and demonstrated successfully, which are potentially important for white light generation.

Annular vesiculobullous eruptions in type 2 reaction in borderline lepromatous leprosy: a case report

An untreated case of BL presented with clinical features of type 2 reaction (T2R) confirmed by histopathology. The case was a 18-year-old female with borderline lepromatous leprosy who developed annular vesiculobullous eruptions oversome of the pre-existing plaques on arms and upper back along with fever and severe neuritis after a short course of ofloxacin intake prescribed for urinary tract infection. In addition to the above lesions, some of the existing lesions showed acute exacerbation characterized by erythema, oedema, tenderness and vesiculobullous eruption. This can be considered as an example of leprous exacerbation as described in older literature. T2Rs are common in lepromatous leprosy and not so uncommonly are observed in borderline lepromatous leprosy. The vesiculobullous and crusted lesions developing over the existing borderline plaques, some of them presenting in an annular pattern in T2R in the form of leprous exacerbation, have been reported rarely in the literature.

Spatiotemporal progression of localized bacterial peritonitis before and after open abdomen lavage monitored by in vivo bioluminescent imaging

BACKGROUND

Bacterial peritonitis is a life-threatening abdominal infection associated with high morbidity and mortality. The rat is a popular animal model for studying peritonitis and its treatment, but longitudinal monitoring of the progression of peritonitis in live animals has been impossible until now and thus required a large number of animals. Our objective was to develop a noninvasive in vivo imaging technique to monitor the spatiotemporal spread of bacterial peritonitis.

METHODS

Peritonitis was induced in 8 immunocompetent male Wistar rats by placing fibrin clots containing 5x10(8) cells of both Bacteroides fragilis (American Type Tissue Culture [ATCC)] 25,285 and bioluminescent Escherichia coli Xen14. After 1 or 2 days, infected clots were removed and open abdomen lavage was performed. In vivo bioluminescent imaging was used to monitor the spread of peritonitis.

RESULTS

Bioluminescent in vivo imaging showed an increase in the area of spread, and the number of E. coli tripled into the rat's abdominal cavity on day 1 after clot insertion; however, on day 2, encapsulation of the clot confined bacterial spread. Bioluminescent E. coli respread over the peritoneal cavity after lavage; within 10 days, however, in vivo imaging showed a decrease of 3-4 orders of magnitude in bacterial load.

CONCLUSION

Bioluminescent in vivo imaging can be effectively used to monitor the spatiotemporal behavior of the peritonitis during 3 different stages of the disease process: initiation, treatment, and follow-up. Imaging allows researchers to repeatedly image the same animal, thereby reducing variability and providing greater confidence in determining treatment efficacies for therapeutic interventions using a small number of animals.

Adsorption of pluronic F-127 on surfaces with different hydrophobicities probed by quartz crystal microbalance with dissipation

Triblock copolymers of polyethylene oxide (PEO) and polypropylene oxide (PPO), that is, PEOn-PPOm-PEOn, better known as Pluronic can adsorb to surfaces in either a pancake or a brushlike configuration. The brushlike configuration is advantageous in numerous applications, since it constitutes a surface repellent to proteins and microorganisms. The conformation of the adsorbed Pluronic layer depends on the hydrophobicity of the substratum surface, but the hydrophobicity threshold above which a brushlike conformation is adopted is unknown. Therefore, the aim of this study is to investigate Pluronic F-127 adsorption on surfaces with different hydrophobicities using a quartz crystal microbalance with dissipation. Adsorption in a brushlike conformation occurred on surfaces with a water contact angle above 80 degrees , as inferred from the thickness, viscosity, and elasticity of the adsorbed layer. The concentration of Pluronic F-127 in solution affected only the kinetics of adsorption and not the final layer thickness or conformation of adsorbed Pluronic molecules.

A dose verification method for high-dose-rate brachytherapy treatment plans

AIM

To evolve a fast dose verification method for high-dose-rate (HDR) brachytherapy treatment plans and to demonstrate its applicability in different clinical cases.

MATERIALS AND METHODS

We developed a software tool in VC++ for the Varisource HDR unit for HDR dosimetry plan verification using TG-43 parameters. HDR treatment dosimetry of a number clinical cases using Varisource was verified by comparison with the treatment planning system (TPS).

RESULTS

A number of different types of clinical cases treated by Varisource were evaluated. TPS calculated dose values and verification code calculated dose values were found to agree to within 3% for most of the dose calculation points.

CONCLUSIONS

We have validated with clinical cases a fast and independent dose verification method of the dosimetry at selected points for HDR brachytherapy treatments plan using TG-43 parameters. This can be used for the verification of the TPS calculated dose at various points. The code is written to work with Varisource, but it can conceivably be modified for other sources also by using the fitted constant of the respective source.

Influence of cell surface appendages on the bacterium-substratum interface measured real-time using QCM-D

Quartz crystal microbalance with dissipation (QCM-D) utilizes an oscillating quartz crystal to register adsorption of rigid masses through a decrease in its resonance frequency f. In addition, QCM-D has the ability to measure the dissipative nature of nonrigid masses adhering to the crystal surface in the form of oscillation amplitude decay time. Although QCM has been applied to register bacterial adhesion to the crystal surface, full interpretation of the frequency change and dissipation signal has hitherto been impossible due to the complex interactions within the distance of 250 nm between the substratum and the bacterial cell surface. Here, we study adhesion of a series of Streptococcus salivarius mutants, possessing various surface appendages of known lengths, as a function of time using QCM-D. In addition, the number of bacteria adhering to the crystal surface was determined. The results show that adhesion of a "bald" bacterium, completely devoid of surface appendages, is registered as a frequency decrease. Adhesion of bacteria possessing surface appendages yields either a much smaller decrease or an increase in frequency, despite the fact they adhere in higher numbers. Furthermore, the magnitude of frequency and dissipation shifts was found to be influenced by the distance at which the cell body was held from the sensor surface by its surface appendages.

Use of Anti-Craving Agents in Soldiers with Alcohol Dependence Syndrome

BACKGROUND

In a search for an effective 'anti-alcohol pill', three modern anti-craving agents have been studied in alcoholics of Army/ DSC, Air Force, Navy and Coast Guard.

METHODS

129 patients of alcohol dependence syndrome were randomly assigned to three groups where topiramate, acamprosate and naltrexone were used as anti-craving agents in a year long prospective study. Of these 92 patients completed the study.

RESULT AND CONCLUSION

Topiramate (76.3%) appears to be significantly more effective (p<0.01) in sustaining abstinence, though naltrexone (57.7%) and acamprosate (60.70%) offer moderate relapse-prevention efficacy. Side effects of all the three agents have been mild, transient and self-limiting. We recommend a trial of topiramate, before invaliding out of any alcoholic soldier.

Binding of estrogen receptor alpha promoter to nuclear proteins of mouse cerebral cortex: effect of age, sex, and gonadal steroids

Majority of estrogen actions in the brain are mediated by estrogen receptor (ER) alpha which in turn is regulated by several factors like circulating levels of gonadal steroid hormones 17beta-estradiol and testosterone, sex and age of the organism. The expression of ERalpha is regulated through interaction between cis-elements of its promoter and proteins present in the nuclei. Here, we have used electrophoretic mobility shift assay (EMSA) to analyze the effect of age, sex, 17beta-estradiol, and testosterone on the binding of ERalpha promoter (-91 to +46 bp) to nuclear proteins from the mouse cerebral cortex. EMSA revealed the formation of three specific complexes in all groups. However, the intensity of these complexes varied as a function of age, sex and treatment with 17beta-estradiol and testosterone. Nuclear proteins from the cerebral cortex of both sexes showed reduced binding with promoter fragment in old mice. Further, competition analysis indicated stronger binding in females than males of both ages. The extent of binding was reduced by 17beta-estradiol and testosterone treatment in both ages and sexes. Thus, these findings demonstrate differential binding of nuclear proteins to mouse ERalpha promoter which may account for different functions of estrogen in the brain.