Search

The present study reported a simple, sensitive, and fast HPTLC method development and quantification of curcumin in C.longa L. The separation was performed on TLC aluminium plates precoated with silica gel 60 F254. Good separation was achieved in the mobile phase of toluene : acetic acid (8 : 2, v/v) at Rf = 0.52 for curcumin and the compound was quantified at its absorbance maxima (λmax) at 419 nm. The objective of the study to perform the HPTLC method development and validation for quantification of curcumin in various marketed turmeric samples. Method validation is done as per ICH guidelines. The linear regression analysis for calibration plots produced R² = 0.999 for Corcumin. Recording of characteristic molecular ion peaks of compound A1 and A2 at 544.5 and 308.3 by mass spectroscopy meets the molecular weight of actual compound. [ABSTRACT FROM AUTHOR]

Rocket ( Eruca vesicaria subsp. sativa ) is a source of sulfur-containing glucosinolates (GSLs). GSLs and their breakdown hydrolysis products (GHPs) are responsible for health-related benefits, such as anti-cancer and anti-neurodegenerative properties. Understanding how phytochemical composition changes between cultivation environments is key to developing cultivars with improved nutritional quality. Two consecutive harvests (first and second regrowth) of crops, grown in both Italy and the UK, were used to determine the phytochemical and transcriptomic differences between six lines of Eruca . Samples were taken upon delivery from field sites (D0) and after five days of cold storage (D5) for each location. Leaves were analysed for sulfur content, volatile organic compounds (VOCs), GSLs, GHPs, and sugars. Transcriptome data were associated with metabolite profiles to identify differentially expressed genes between plants grown in the two environments. VOC compounds (carbon disulfide, methyl thiocyanate) were associated with growth environment and with differences in sulfur metabolism gene expression ( APR2, LSU2, LSU3, SDI1, SiR ), GSL biosynthesis ( MYB28, FMOGS-OX2 ) and GHP formation ( ESM1, TGG1, TGG2 ). The concentrations of sugars were an order of magnitude greater in UK grown samples (up to 29.9 mg g -1 dry weight; dw). Sulfur content was significantly higher in the Italy plant samples (11.4 - 20.1 mg g -1 dw), which was in turn associated with higher concentrations of GSLs (pentyl GSL, up to 15.8 μmol g -1 dw; sinigrin, up to 0.005 μmol g -1 dw; glucoraphanin, up to 5.1 μmol g -1 dw; glucorucolamine, up to 23.6 μmol g -1 dw; neoglucobrassicin, up to 5.3 μmol g -1 dw) and hydrolysis products (sativin, up to 13.5 μmol g -1 dw; erucin, up to 1 μmol g -1 dw; sulforaphane, up to 34.7 μmol g -1 dw). VOC profiles of plants cultivated in the UK were distinct from Italy grown plants, with higher relative abundances of alkanes and esters in second cut and shelf-life (D5) samples. The data indicate a significant interaction of cultivar response with environment, highlighting the difficulty of producing Eruca crops with consistent phytochemical and postharvest traits. Genes with differential expression between plants grown in Italy and the UK could be used as markers of phytochemical quality and composition., Competing Interests: Author RT was employed by the company Elsoms Seeds Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Bell, Chadwick, Puranik, Jasper, Tudor, Methven and Wagstaff.)

Background: Autoimmune thyroid disease (AITD) is an inflammatory condition that primarily affects women between the ages of 30 and 50. It has been hypothesised that AITD causes salivary glands to produce less saliva due to its endocrine effects. Studies showing the effect of AITD on salivary glands are very scarce. The aim of this study was to compare AITD patients with controls who were of a similar age and gender in terms of salivary metrics and the prevalence of dental caries. Methods: 200 subjects in Bangalore city (100 AITD subjects and 100 healthy subjects as controls) participated in a cross-sectional study. Subjective oral dryness was assessed using Farsi's criteria. Salivary parameters and caries were assessed using GC Saliva-Check BUFFER kit and WHO caries criteria respectively. Descriptive and analytical statistics were done. Significant data was defined as a p value of <0.05. Results : When compared to controls, the AITD group had substantially more subjective mouth dryness and dental caries. Unstimulated (USFR) and stimulated salivary flow rate (SFR), pH and buffering capacity were reduced in AITD group whereas viscosity was high. There was a significant negative correlation between USFR, SFR, subjective oral dryness and dental caries. In a linear regression, there was no association between age, gender, socioeconomic status (SES), thyroid stimulating hormone (TSH), salivary viscosity, pH, buffering capacity and dental caries. Dental caries, USFR and SFR demonstrated a substantial relationship. Conclusions : The present research may indicate an underlying association between thyroid and salivary gland dysfunction resulting in oral dryness and high dental caries experience., Competing Interests: No competing interests were disclosed., (Copyright: © 2023 K S A et al.)

Lumichrome (LC) is the major photodegradation product of biologically important flavin cofactors. Since LC serves as a structural comparison with the flavins; understanding excited states of LC is fundamentally important to establish a connection with photophysics of different flavins, such as lumiflavin (LF), riboflavin (RF), flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Herein, we deduce the initial excited state structural dynamics of LC using UV resonance Raman (UVRR) intensity analysis. The UVRR spectra at wavelengths across the 260 nm absorption band of LC were measured and resulting Raman excitation profiles and absorption spectrum were self-consistently simulated using a time-dependent wave packet formalism to extract the initial excited state structural and solvent broadening parameters. These results are compared with those obtained for other flavins following UV excitations. We find that LC undergoes a very distinct instantaneous charge redistribution than flavins, which is attributed to the extended π-conjugation present in flavins but missing in LC. The homogeneous broadening linewidth of LC appears to be lower than that of LF, while the inhomogeneous broadening values are comparable, indicating greater solvent interaction with excited flavin on ultrafast timescale compared with LC, whereas on longer timescale these interactions are almost similar., (© 2022 American Society for Photobiology.)

Eruca vesicaria subsp. sativa is a leafy vegetable of the Brassicaceae family known for its pungency. Variation in growing conditions, leaf age, agronomic practices, and variety choice lead to inconsistent quality, especially in content of isothiocyanates (ITCs) and their precursor glucosinolates (GSLs). We present the first linkage and Quantitative Trait Loci (QTL) map for Eruca, generated using a population of 139 F 4 lines. A significant environmental effect on the abundance of primary and secondary metabolites was observed, with UK-grown plants containing significantly higher concentrations of glucoraphanin, malic acid, and total sugars. Italian-grown plants were characterized by higher concentrations of glucoerucin, indolic GSLs, and low monosaccharides. 20 QTL were identified and associated with robust SNP markers. Five genes putatively associated with the synthesis of the GSL 4-methoxyglucobrassicin (4MGB) were identified as candidate regulators underlying QTL. Analysis revealed that orthologs of MYB51, IGMT1 and IGMT4 present on LG1 are associated with 4MGB concentrations in Eruca. This research illustrates the utility of the map for identifying genes associated with nutritional composition in Eruca and its value as a genetic resource to assist breeding programs for this leafy vegetable crop., (© 2022. The Author(s).)

Competing Interests: There are no conflicts of interest.

Objective: Right ventricular (RV) dysfunction is associated with poor outcomes after cardiac surgery. The aim of this study was to assess RV systolic and diastolic function in the perioperative period after off-pump coronary artery bypass grafting (OPCAB)., Design: Prospective observational study., Settings: Tertiary care hospital., Participants: Thirty adult patients undergoing OPCAB., Interventions: None., Measurements and Main Results: Transthoracic echocardiography was performed twice: first preoperatively and second postoperatively, when patients were moved to wards. The following five parameters of RV systolic function were used: tricuspid annular plane systolic excursion (TAPSE), systolic tissue Doppler imaging of lateral tricuspid annulus (S'), fractional area change (FAC), RV myocardial performance index (RIMP), and isovolumic acceleration (IVA). Grading of RV diastolic function (RVDD) was done as per guidelines. Paired t test was used for comparing means and χ 2 test was used for categorical and ordinal data. The parameters of RV longitudinal function (TAPSE and S') reduced significantly (preoperative 21.93 ± 2.80 mm and 13.24 ± 2.24 cm/s to postoperative 11.67 ± 1.91 mm and 10.31 ± 1.56 cm/s, respectively, p < 0.001), whereas parameters of RV global function (FAC, RIMP, and IVA) remained preserved (preoperative 46.75 ± 6.80%, 0.34 ± 0.06, and 4.66 ± 0.87 m/s 2 to postoperative 46.21 ± 6.44%, 0.36 ± 0.06, and 4.37 ± 0.83 m/s 2 ; p values of 0.76, 0.13, and 0.11, respectively). The median grade of RVDD worsened from normal in the preoperative period to pseudo-normal in the postoperative period (p < 0.001). The changes in both RV systolic and diastolic function were similar in patients with normal and reduced left ventricular systolic function., Conclusions: RV function can be assessed in perioperative settings with two-dimensional and tissue Doppler imaging. For systolic function assessment, exclusive measurement of longitudinal parameters might be inadequate; use of complementary global parameters like FAC, RIMP, and IVA is essential to complete the RV assessment after OPCAB. RVDD worsened significantly after OPCABG., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Rocket ( Eruca sativa ) is a source of health-related metabolites called glucosinolates (GSLs) and isothiocyanates (ITCs) but little is known of the genetic and transcriptomic mechanisms responsible for regulating pre and postharvest accumulations. We present the first de novo reference genome assembly and annotation, with ontogenic and postharvest transcriptome data relating to sulfur assimilation, transport, and utilization. Diverse gene expression patterns related to sulfur metabolism, GSL biosynthesis, and glutathione biosynthesis are present between inbred lines of rocket. A clear pattern of differential expression determines GSL abundance and the formation of hydrolysis products. One breeding line sustained GSL accumulation and hydrolysis product formation throughout storage. Multiple copies of MYB28, SLIM1, SDI1, and ESM1 have increased and differential expression postharvest, and are associated with GSLs and hydrolysis product formation. Two glucosinolate transporter gene (GTR2) copies were found to be associated with increased GSL accumulations in leaves. Monosaccharides (which are essential for primary metabolism and GSL biosynthesis, and contribute to the taste of rocket) were also quantified in leaves, with glucose concentrations significantly correlated with the expression of numerous GSL-related genes. Significant negative correlations were observed between the expression of glutathione synthetase (GSH) genes and those involved in GSL metabolism. Breeding line " B " showed increased GSH gene expression and low GSL content compared to two other lines where the opposite was observed. Co-expression analysis revealed senescence ( SEN1 ) and oxidative stress-related ( OXS3 ) genes have higher expression in line B , suggesting that postharvest deterioration is associated with low GSL concentrations., (Copyright © 2020 Bell, Chadwick, Puranik, Tudor, Methven, Kennedy and Wagstaff.)

The bacterial cell envelope of Gram-negative bacteria is a complex biological barrier with multiple layers consisting of the inner membrane, periplasm of peptidoglycan, and the outer membrane with lipopolysaccharides (LPS). With rising antimicrobial resistance there is increasing interest in understanding interactions of small molecules with the cell membrane to aid in the development of novel drug molecules. Hence suitable representations of the bacterial membrane are required to carry out meaningful molecular dynamics simulations. Given the complexity of the cell envelope, fully atomistic descriptions of the cell membrane with explicit solvent are computationally prohibitive, allowing limited sampling with small system sizes. However, coarse-grained (CG) models such as MARTINI allow one to study phenomena at physiologically relevant length and time scales. Although MARTINI models for lipids and the LPS are available in literature, a suitable CG model of peptidoglycan is lacking. Using an all-atom model described by Gumbart et al. [ PLoS Comput. Biol. 2014 , 10 , e1003475], we develop a CG model of the peptidoglycan network within the MARTINI framework. The model is parametrized to reproduce the end-to-end distance of glycan strands. The structural properties such as the equilibrium angle between adjacent peptides along the strands, area per disaccharide, and cavity size distributions agree well with the atomistic simulation results. Mechanical properties such as the area compressibility and the bending modulus are accurately reproduced. While developing novel antibiotics it is important to assess barrier properties of the peptidogylcan network. We evaluate and compare the free energy of insertion for a thymol molecule using umbrella sampling on both the MARTINI and all-atom peptidoglycan models. The insertion free energy was found to be less than k B T for both the MARTINI and all-atom models. Additional restraint free simulations reveal rapid translocation of thymol across peptidogylcan. We expect that the proposed MARTINI model for peptidoglycan will be useful in understanding phenomena associated with bacterial cell walls at larger length and time scales, thereby overcoming the current limitations of all-atom models.

The bacterial cell envelope is a complex multilayered structure evolved to protect bacteria in hostile environments. An understanding of the molecular basis for the interaction and transport of antibacterial therapeutics with the bacterial cell envelope will enable the development of drug molecules to combat bacterial infections and suppress the emergence of drug-resistant strains. Here we report the successful creation of an in vitro supported lipid bilayer (SLB) platform of the outer membrane (OM) of E. coli , an archetypical Gram-negative bacterium, containing the full smooth lipopolysaccharide (S-LPS) architecture of the membrane. Using this platform, we performed fluorescence correlation spectroscopy (FCS) in combination with molecular dynamics (MD) simulations to measure lipid diffusivities and provide molecular insights into the transport of natural antimicrobial agent thymol. Lipid diffusivities measured on symmetric supported lipid bilayers made up of inner membrane lipids show a distinct increase in the presence of thymol as also corroborated by MD simulations. However, lipid diffusivities in the asymmetric OM consisting of only S-LPS are invariant upon exposure to thymol. Increasing the phospholipid content in the LPS-containing outer leaflet improved the penetration toward thymol as reflected in slightly higher relative diffusivity changes in the inner leaflet when compared with the outer leaflet. Free-energy computations reveal the presence of a barrier (∼6 kT ) only in the core-saccharide region of the OM for the translocation of thymol while the external O-antigen part is easily traversed. In contrast, thymol spontaneously inserts into the inner membrane. In addition to providing leaflet-resolved penetration barriers in bacterial membranes, we also assess the ability of small molecules to penetrate various membrane components. With rising bacterial resistance, our study opens up the possibility of screening potential antimicrobial drug candidates using these realistic model platforms for Gram-negative bacteria.

Background and Aims: There is conflicting evidence on adverse effect of Pulmonary Arterial Hypertension (PAH) on outcomes after cardiac surgery for rheumatic heart disease (RHD). The authors studied Indian patients with RHD and preoperative PAH, who undergo cardiac surgery with a hypothesis that they have poor short and long-term outcomes., Methods: This was a retrospective observational study of 407 patients. The patients were divided in three groups based on PAH estimated on echocardiograph as; no or mild PAH (pulmonary artery systolic pressure (PASP) <30 mm of Hg); moderate PAH (PASP 31-55 mm of Hg) and severe PAH (PASP >55 mm of Hg). The primary endpoint was in-hospital mortality and major morbidities; while secondary endpoint was long-term survival., Results: In-hospital mortality was 24 (5.9%); and was not different in patients with severe, (9.1%), moderate (4.5%) or mild PAH (2.8%) ( P = 0.09). Patients with severe PAH had higher incidence of prolonged ventilation ( P = 0.007). Factors independently associated with mortality were; >2-packed cell transfusion, prolonged ventilation and acute kidney injury but not moderate and severe PAH. Patients with mitral stenosis (MS) and severe PAH had significantly higher mortality as compared to no or mild PAH ( P = 0.03) on long-term follow-up [81.37% (mean duration 19.40 ± 14.10 months)], mortality was 8% and not statistically different ( P = 0.25) across PAH categories., Conclusion: Moderate and severe PAH does not affect short and long term outcomes of patients undergoing valve surgery for RHD. Patients with MS with severe PAH had higher mortality compared to those with no PAH., Competing Interests: There are no conflicts of interest.

Melanin is an abundant biopigment in the animal kingdom, but its structure remains poorly understood. This is a substantial impediment to understanding the mechanistic origin of its observed functions. Proposed models of melanin structure include aggregates of both linear and macrocyclic units and noncovalently held monomers. Both models are broadly in agreement with current experimental data. To constrain the structural and kinetic models of melanin, experimental data of high resolution with chemical specificity accompanied by atomistic modeling are required. We have addressed this by obtaining electronic absorption, infrared, and ultraviolet resonance Raman (RR) spectra of melanin at several wavelengths of excitation that are sensitive to small changes in structure. From these experiments, we observed kinetics of the formation of different species en route to melanin polymerization. Exclusive chemical signatures of monomer 3,4-dihydroxyphenylalanine (dopa), intermediate dopachrome (DC), and early-time polymer are established through their vibrational bands at 1292, 1670, and 1616 cm -1 respectively. Direct evidence of reduced heterogeneity of melanin oligomers in tyrosinase-induced formation is provided from experimental measurements of vibrational bandwidths. Models made with density functional theory show that the linear homopolymeric structures of 5,6-dihydroxyindole can account for experimentally observed wavenumbers and broad bandwidth in Raman spectra of dopa-melanin. We capture resonance Raman (RR) signature of DC, the intermediate stabilized by the enzyme tyrosinase, for the first time in an enzyme-assisted melanization reaction using 488 nm excitation wavelength and propose that this wavelength can be used to probe reaction intermediates of melanin formation in solution.

E. coli AlkB, a repair enzyme of the dioxygenase family, catalyses the removal of mutagenic methylated nucleotides from the genome. Known for substrate promiscuity, AlkB's catalytic mechanism and conformational changes accompanying substrate binding have been extensively dissected. However, the structural parameters of various substrates governing their recognition by AlkB still remain elusive. In this work, through solution-state vibrational spectra of methylated substrates bound to AlkB in combination with computational analysis, we show that the recognition specificity is dictated by the protonation states of the substrates. Specificity is conferred predominantly through hydrogen bonding and cation-π interactions. Furthermore, we report on the interaction of AlkB with normal, unmodified nucleotides, wherein the presence of an exocyclic amino group serves as an essential criterion for the initial process of substrate recognition. Taken together, these results provide a rationale for structural determinants of substrate specificity as well as mode of lesion discrimination employed by AlkB., Competing Interests: The authors declare that they have no conflicts of interest with the contents of this article., (This journal is © The Royal Society of Chemistry.)

Background: Prosthetic valve implantation requires postoperative prophylactic anticoagulation to preclude thrombotic events. The aim of this review is to assess the role of anticoagulation therapy in the management of valve replacement patients., Methodology: Literature from PubMed, Embase, Medline and Google Scholar were searched using the terms "valvular heart disease", "anticoagulant", "mechanical heart valve", "bioprosthesis", "bridging", "Vitamin K antagonist (VKA)", and "acenocoumarol". A committee comprising leading cardiothoracic surgeons from India was convened to review the literature and suggest key practice points., Results: Prosthetic valve implantation requires postoperative prophylactic anticoagulation to preclude thrombotic events. A paramount risk of thromboembolic events is observed during the first three months after surgery for both mechanical and bioprosthetic devices. The VKA therapy with individualized target international normalized ratio (INR) is recommended in patients after prosthetic valve replacement. Therapies for the management of prosthetic valve complications should be based on the type of complications. Special care is mandated in distinguished individuals and those with various co-morbidities., Conclusion: In patients with prosthetic valve replacement, anticoagulant therapy with VKA seems to be an effective option. The role for non-VKA oral anticoagulants in the setting of prosthetic valve replacement has yet to be established. Furthermore, whether the novel oral anticoagulants are safe and efficacious in patients after placement of a bioprosthetic valve remains unanswered., (© Journal of the Association of Physicians of India 2011.)

We report deep UV initiated excited state dynamics of the canonical nucleobase adenine (Ade) through Resonance Raman (RR) intensity analysis. RR spectra of Ade at excitation wavelengths throughout the B b absorption band in the 210-230 nm wavelength range are measured and subsequently converted to scattering cross-sections. The time-dependent wave packet (TDWP) formalism has been employed for self-consistent simulations of the resulting wavelength dependent Raman excitation profiles (REP) and absorption spectrum of Ade. These simulations yield instantaneous nuclear dynamics of Ade within tens of femtoseconds (fs) of photoabsorption as structural distortions, linewidth broadening and solvation parameters. The instantaneous geometrical distortions of the purine ring following photoexcitation into the B b state are analyzed vis-à-vis the low energy L a state (∼260 nm) of Ade. We find that while photoabsorption by the L a state causes major distortions of the imidazole ring, pyrimidine ring suffers maximal changes following B b excitation. Seven in-plane stretching vibrations out of fifteen resonantly enhanced modes of Ade are found to contribute 76% of the total internal reorganization energy (981 cm -1 ) in the B b excited state. In addition, the inertial response of the solvation shell to photoexcitation is found to be of 1190 cm -1 in magnitude, and with a relaxation time of 26.5 fs. A parallel comparison is drawn between the UV-C initiated photodynamics of Ade (6-aminopurine) with that of two substituted purines, viz., 6-chloroguanine (6-ClG or 2-amino-6-chloropurine) and guanine (2-amino-6-oxo-purie) which were reported earlier.

Objectives: Use of pregabalin is increasing in cardiac surgical patients. However, studies using comprehensive scoring systems are lacking on the drug's impact on postoperative recovery. The authors tested the hypothesis that perioperative oral pregabalin improves the postoperative quality of recovery as assessed using the Quality of Recovery (QoR-40) questionnaire in patients undergoing off-pump coronary artery bypass grafting (OPCABG)., Design: This was a randomized, double-blind, placebo-controlled study., Settings: Tertiary-care hospital., Participants: Patients undergoing OPCABG., Interventions: Patients were assigned randomly to the following 2 groups: the pregabalin group (those who received pregabalin, 150 mg capsule orally, 1 hour before surgery and 2 days postoperatively [75 mg twice a day] starting after extubation; n = 37); and the control group (those who received 2 similar-looking multivitamin capsules at similar times; n = 34). The QoR-40 scores were noted preoperatively and 24 hours after extubation., Measurements and Main Results: Both groups were comparable in terms of preoperative patient characteristics and baseline QoR-40 scores. Global scores were significantly improved in the pregabalin group compared with the control group in the postoperative period (177±9 v 170±9; p = 0.002). QoR-40 values in the dimensions of emotional state (p = 0.005), physical comfort (p = 0.04), and pain (p = 0.02) were improved in the pregabalin group., Conclusions: Perioperative pregabalin improved postoperative quality of recovery as assessed using the QoR-40 questionnaire in patients undergoing OPCABG. Perioperative pregabalin offered advantages beyond better pain control, such as improved physical comfort and better emotional state; therefore, the drug's use in the perioperative period is recommended., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We report measurement of resonance Raman (RR) spectra of guanosine-5'-monophosphate (GMP), a DNA nucleotide at excitation wavelengths throughout its ππ* absorption band (B b ) in the 210-230 nm range. From these data, we constructed wavelength-dependent Raman intensity excitation profiles (REPs) for all observed modes. These profiles and the absorption spectrum were then modeled using self-consistent simulations based on the time-dependent wave packet propagation formalism. We inferred the initial structural dynamics of GMP immediately after photoexcitation in terms of dimensionless displacements. The simulations also provide linewidth-broadening parameters that in turn report on the time scale of dynamics. We compared deduced structural changes in the purine ring upon photoabsorption into the B b state with those deduced for the two lowest lying ππ* (L a and L b at 280 and 248 nm, respectively) excited states of GMP. We find that excitation to the L b state lengthens C 6 -N 1 and C 2 ═N 3 bonds, which lie along the formation coordinate of various oxidative adducts but B b excitation does not. We also find that photoabsorption by the B b state weakens the C 8 -N 9 bond and thus might assist imidazole ring opening via cleavage of the same bond. Electronic excitation to different ππ* states of the guanine chromophore results in contrasting structural changes; although absorption by the L a and L b states induces expansion of pyrimidine and contraction of imidazole rings, excitation results in overall shrinkage of both the rings. Computed absolute changes in internal coordinates imply that photoexcitation to any of the three singlet states of GMP does not lead directly to the formation of a cation radical of guanine.

The mutagenic 8-oxoguanosine monophosphate, the predominant product of DNA oxidation, is excised by formamidopyrimidine glycosylase (Fpg) in bacteria. The mechanism of recognition of 8-oxodG, which differs subtly from its normal counterpart, guanosine monophosphate (dG), by Escherichia coli Fpg remains elusive due to the lack of structural data of E. coli Fpg bound to 8-oxodG. Here, we present solution-state structure of 8-oxodG oligomer bound to E. coli E3Q Fpg using UV resonance Raman (UVRR) spectroscopy. The vibrational spectra report on the π-stacking and hydrogen bonding interactions established by 8-oxodG with E. coli E3Q Fpg. Furthermore, we report on the interactions of E. coli E3Q Fpg with the normal, undamaged nucleotide, dG. We show that E. coli Fpg recognizes 8-oxodG and dG through their C2-amino group but only 8-oxodG forms extensive contacts with E. coli Fpg. Our findings provide a basis for mechanism of lesion recognition by E. coli Fpg.

Introduction: Early childhood caries (ECC) is a virulent form of dental caries that can destroy the primary dentition of toddlers and preschool children. The aim was to determine the relationship of feeding methods and oral Streptococcus mutans count in 3- to 5-year-old children with ECC., Materials and Methods: A cross-sectional study was conducted in children aged 3 to 5 years. Participating mothers were interviewed regarding child's demographic profile, educational level and socioeconomic status of parents, past medical and dental history of the mother and child, child's feeding habits, and dietary habits and oral hygiene practices of mother and child. Clinical examination for dental caries was done using the World Health Organization criteria (1997). Salivary samples of mother-child pair were collected to determine the pH, flow rate, and S. mutans count. Statistical tests, such as Student's t-test, analysis of variance, and Pearson's correlation were applied., Results: Out of 150 mother-child pair, statistically significant difference in the caries experience was found between mothers and children with high and low S. mutans count. Moderate but statistically significant negative correlation was found between mean decayed, missing, and filled teeth of mothers and mean decayed, extracted and filled teeth (deft) of children with high S. mutans count. Regarding deft, there was no statistically significant difference between children who were exclusively breast fed (7.85 ± 2.94), exclusively bottle-fed (8.67 ± 3.98), and both breast and bottle-fed (7.77 ± 2.91)., Conclusion: The mean caries experience of mothers and children was 2.66 ± 2.01 and 7.82 ± 2.94 respectively, with decayed component being maximum. Moderate and significant correlation (r = 0.5) was found between S. mutans of mothers and children in saliva. Significant negative correlation was found between mothers and children with high S. mutans count (r = -0.0284; p = 0.046)., How to Cite This Article: Bullappa D, Puranik MP, Sowmya KR, Nagarathnamma T. Association of Feeding Methods and Streptococcus mutans Count with Early Childhood Caries: A Cross-sectional Study. Int J Clin Pediatr Dent 2017;10(2):119-125., Competing Interests: Source of support: Nil Conflict of interest: None

Context: One of the main limitations of off-pump coronary artery bypass grafting (OPCAB) is the occasional need for intraoperative conversion (IOC) to on-pump coronary artery bypass grafting. IOC is associated with a significantly increased risk of mortality and postoperative morbidity. The impact of IOC on outcome cannot be assessed by a randomized control design., Aims: The objective of this study was to analyze the incidence, risk factors, and impact of IOC on the outcome in patients undergoing OPCAB., Settings and Design: Three tertiary care level hospitals; retrospective observational study., Subjects and Methods: This retrospective observational study included 1971 consecutive patients undergoing  OPCAB from January 2012 to October 2015 at three tertiary care level hospitals by four surgeons. The incidence, patient characteristics, cause of IOC, and its impact on outcome were studied., Statistical Analysis Used: The cohort was divided into two groups according to IOC. Univariate logistic regression was performed to describe the predictors of IOC. Variables that were found to be significant in univariate analysis were introduced into multivariate model, and adjusted odds ratio (OR) was calculated. To further assess the independent effect of IOC on mortality, propensity score matching with a 5:1 ratio of non-IOC to IOC was performed., Results: The overall all-cause in-hospital mortality was 2.6%. IOC was needed in 128 (6.49%) patients. The mortality in the IOC group was significantly higher than non-IOC group (21 of 128 [16.4%] vs. 31 of 1843 [1.7%], P = 0.0001). The most common cause for IOC was hemodynamic disturbances during grafting to the obtuse marginal artery (51/128; 40%). On multivariate logistic regression analysis, left main disease, pulmonary hypertension, and mitral regurgitation independently predicted IOC. We obtained a propensity-matched sample of 692 patients (No IOC 570; IOC 122), and IOC had OR of 16.26 (confidence interval 6.3-41; P < 0.0001) for mortality in matched population., Conclusions: Emergency IOC increases odds for mortality by 16-fold. Hence, identification of patients at higher risk of IOC may improve the outcome.

Background: Periodontal deterioration has been reported to be associated with systemic diseases such as cardiovascular disease (CVD), diabetes mellitus, respiratory disease, liver cirrhosis, bacterial pneumonia, nutritional deficiencies, and adverse pregnancy outcomes., Aim: The present study assessed the periodontal disease among patients with systemic conditions such as diabetes, CVD, and respiratory disease., Materials and Methods: The study population consisted of 220 patients each of CVD, respiratory disease, and diabetes mellitus, making a total of 660 patients in the systemic disease group. A control group of 340 subjects were also included in the study for comparison purpose. The periodontal status of the patients with these confirmed medical conditions was assessed using the community periodontal index of treatment needs (CPITNs) index., Results: The prevalence of CPITN code 4 was found to be greater among the patients with respiratory disease whereas the mean number of sextants with score 4 was found to be greater among the patients with diabetes mellitus and CVD. The treatment need 0 was found to be more among the controls (1.18%) whereas the treatment need 1, 2, and 3 were more among the patients with respiratory disease (100%, 97.73%, and 54.8%), diabetes mellitus (100%, 100% and 46.4%), and CVD (100%, 97.73%, and 38.1%), in comparison to the controls (6.18%)., Conclusion: From the findings of the present study, it can be concluded that diabetes mellitus, CVD, and respiratory disease are associated with a higher severity of periodontal disease., Competing Interests: There are no conflicts of interest.

The photophysical properties of natural nucleobases and their respective nucleotides are ascribed to the sub-picosecond lifetime of their first singlet states in the UV-B region (260-350 nm). Electronic transitions of the ππ* type, which are stronger than those in the UV-B region, lie at the red edge of the UV-C range (100-260 nm) in all isolated nucleobases. The lowest energetic excited states in the UV-B region of nucleobases have been investigated using a plethora of experimental and theoretical methods in gas and solution phases. The sub-picosecond lifetime of these molecules is not a general attribute of all nucleobases but specific to the five primary nucleobases and a few xanthine and methylated derivatives. To determine the overall UV photostability, we aim to understand the effect of more energetic photons lying in the UV-C region on nucleobases. To determine the UV-C initiated photophysics of a nucleobase system, we chose a halogen substituted purine, 6-chloroguanine (6-ClG), that we had investigated previously using resonance Raman spectroscopy. We have performed quantitative measurements of the resonance Raman cross-section across the Bb absorption band (210-230 nm) and constructed the Raman excitation profiles. We modeled the excitation profiles using Lee and Heller's time-dependent theory of resonance Raman intensities to extract the initial excited state dynamics of 6-ClG within 30-50 fs after photoexcitation. We found that imidazole and pyrimidine rings of 6-ClG undergo expansion and contraction, respectively, following photoexcitation to the Bb state. The amount of distortions of the excited state structure from that of the ground state structure is reflected by the total internal reorganization energy that is determined at 112 cm(-1). The contribution of the inertial component of the solvent response towards the total reorganization energy was obtained at 1220 cm(-1). In addition, our simulation also yields an instantaneous response of the first solvation shell within an ultrafast timescale of less than 30 fs following photoexcitation.

In enzymes that conduct complex reactions involving several substrates and chemical transformations, the active site must reorganize at each step to complement the transition state of that chemical step. Adenylosuccinate synthetase (ADSS) utilizes a molecule each of guanosine 5'-monophosphate (GTP) and aspartate to convert inosine 5'-monophosphate (IMP) into succinyl adenosine 5'-monophosphate (sAMP) through several kinetic intermediates. Here we followed catalysis by ADSS through high-resolution vibrational spectral fingerprints of each substrate and intermediate involved in the forward reaction. Vibrational spectra show differential ligand distortion at each step of catalysis, and band positions of substrates are influenced by binding of cosubstrates. We found that the bound IMP is distorted toward its N1-deprotonated form even in the absence of any other ligands. Several specific interactions between GTP and active-site amino acid residues result in large Raman shifts and contribute substantially to intrinsic binding energy. When both IMP and GTP are simultaneously bound to ADSS, IMP is converted into an intermediate 6-phosphoryl inosine 5'-monophosphate (6-pIMP). The 6-pIMP·ADSS complex was found to be stable upon binding of the third ligand, hadacidin (HDA), an analogue of l-aspartate. We find that in the absence of HDA, 6-pIMP is quickly released from ADSS, is unstable in solution, and converts back into IMP. HDA allosterically stabilizes ADSS through local conformational rearrangements. We captured this complex and determined the spectra and structure of 6-pIMP in its enzyme-bound state. These results provide important insights into the exquisite tuning of active-site interactions with changing substrate at each kinetic step of catalysis.

Deaza analogues of nucleobases are potential drugs against infectious diseases caused by parasites. A caveat is that apart from binding their target parasite enzymes, they also bind and inhibit enzymes of the host. In order to design derivatives of deaza analogues which specifically bind target enzymes, knowledge of their molecular structure, protonation state, and predominant tautomers at physiological conditions is essential. We have employed resonance Raman spectroscopy at an excitation wavelength of 260 nm, to decipher solution structure of 9-deazaguanine (9DAG) and 9-deazahypoxanthine (9DAH). These are analogues of guanine and hypoxanthine, respectively, and have been exploited to study static complexes of nucleobase binding enzymes. Such enzymes are known to perturb pKa of their ligands, and thus, we also determined solution structures of these analogues at two, acidic and alkaline, pH. Structure of each possible protonation state and tautomer was computed using density functional theoretical calculations. Species at various pHs were identified based on isotopic shifts in experimental wavenumbers and by comparing these shifts with corresponding computed isotopic shifts. Our results show that at physiological pH, N1 of pyrimidine ring in 9DAG and 9DAH bears a proton. At lower pH, N3 is place of protonation, and at higher pH, deprotonation occurs at N1 position. The proton at N7 of purine ring remains intact even at pH 12.5. We have further compared these results with naturally occurring nucleotides. Our results identify key vibrational modes which can report on hydrogen bonding interactions, protonation and deprotonation in purine rings upon binding to the active site of enzymes.

Analogues of intermediates involved in the purine salvage pathway can be exploited as potential drug molecules against enzymes of protozoan parasites. To develop such analogues we need knowledge of the solution structures, predominant tautomer at physiological pH and protonation-state of the corresponding natural ligand. In this regard, we have employed ultraviolet resonance Raman spectroscopy (UVRR) in combination with density functional theory (DFT) to study the solution structures of two relatively unexplored intermediates, 6-phosphoryl IMP (6-pIMP) and succinyl adenosine-5'-monophosphate (sAMP), of purine salvage pathway. These molecules are intermediates in a two step enzymatic process that converts inosine-5'-monpophosphate (IMP) to adenosine-5'-monophosphate (AMP). Experimental data on the molecular structure of these ligands is lacking. We report UVRR spectra of these two ligands, obtained at an excitation wavelength of 260 nm. Using isotope induced shifts and DFT calculations we assigned observed spectra to computed normal modes. We find that sAMP exists as neutral species at physiological pH and the predominant tautomer in solution bears proton at N10 position of purine ring. Though transient in solution, 6-pIMP is captured in the enzyme-bound form. This work provides the structural information of these ligands in solution state at physiological pH. We further compare these structures with the structures of AMP and IMP. Despite the presence of similar purine rings in AMP and sAMP, their UVRR spectra are found to be very different. Similarly, though the purine ring in 6-pIMP resembles that of IMP, UVRR spectra of the two molecules are distinct. These differences in the vibrational spectra provide direct information on the effects of exocyclic groups on the skeletal structures of these molecules. Our results identify key bands in the vibrational spectra of these ligands which may serve as markers of hydrogen bonding interactions upon binding to the active-sites of enzymes., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Objectives: To evaluate the EuroSCORE II for risk stratification in patients undergoing off-pump coronary artery bypass (OPCAB) surgery., Design: A retrospective observational study., Setting: Two tertiary care hospitals., Participants: Participants were 1,211 patients undergoing OPCAB surgery., Interventions: No interventions were implemented., Measurements and Main Results: The EuroSCORE II estimated the operative risk for each patient. The calibration of the scoring system was assessed using the Hosmer Lemeshow test, and the discriminative capacity was estimated with area under receiver operating characteristic curves. The incidence, patient characteristics, causes of intraoperative conversion to on-pump coronary artery bypass (ONCAB), and outcome were studied. The all-cause in-hospital mortality was 2.39%. Predicted mortality with the EuroSCORE II was 2.03±1.63. Using the Hosmer Lemeshow test, a C statistic of 8.066 (p = 0.472) was obtained, indicating satisfactory model fit. The calculated area under the receiver operating characteristic curve was 0.706 (p = 0.0002), indicating good discriminatory power. Emergency intraoperative conversion to ONCAB occurred in 6.53% of patients. The mortality in the ONCAB group was significantly higher compared with patients who underwent successful OPCAB surgery (15.18% v 1.5%, p<0.0001). On multiple regression analysis with conversion to ONCAB as the endpoint, associated factors were patients with a higher EuroSCORE II (odds ratio = 1.13, confidence interval = 1.03-1.27) and more-than-trivial mitral regurgitation (odds ratio = 1.84, confidence interval = 1.07-3.06). Net reclassification improvement of 0.714 (p<0.0001) was obtained when on-pump conversion was added to the EuroSCORE II., Conclusions: The EuroSCORE II has satisfactory calibration and discrimination power to predict mortality after OPCAB surgery. Intraoperative conversion to ONCAB is a major complication of OPCAB surgery. A higher EuroSCORE II also predicts higher probability of conversion to ONCAB., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Plasmodium falciparum (Pf) hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is a potential therapeutic target. Compared to structurally homologous human enzymes, it has expanded substrate specificity. In this study, 9-deazapurines are used as in situ probes of the active sites of human and Pf HGPRTs. Through the use of these probes it is found that non-covalent interactions stabilise the pre-transition state of the HGPRT-catalysed reaction. Vibrational spectra reveal that the bound substrates are extensively distorted, the carbonyl bond of nucleobase moiety is weakened and the substrate is destabilised along the reaction coordinate. Raman shifts of the human and Pf enzymes are used to quantify the differing degrees of hydrogen bonding in the homologues. A decreased Raman cross-section in enzyme-bound 9-deazaguanine (9DAG) shows that the phenylalanine residue (Phe186 in human and Phe197 in Pf) of HGPRT stacks with the nucleobase. Differential loss of the Raman cross-section suggests that the active site is more compact in human HGPRT as compared to the Pf enzyme, and is more so in the phosphoribosyl pyrophosphate (PRPP) complex 9DAG-PRPP-HGPRT than in 9-deazahypoxanthine (9DAH)-PRPP-HGPRT., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An important part of the protein folding process is the consolidation of the protein core through the formation of specific, directional contacts after the initial hydrophobic collapse. Here, we simultaneously monitor formation of core contacts and assembly of secondary structure through salt-induced folding by using resonance Raman spectroscopy. Unfolded barstar at pH 12 was refolded by gradual addition of sodium sulfate salt. Altered spectral characteristics of the Trp53 residue suggest that the core of the protein attains a CH-π interaction at a low concentration of the salt, with an increase in the packing density. Further increase in salt concentration produces a reduction in the solvent accessibility of the core. These data provide evidence that the core of the protein becomes rigid upon the addition of 0.6 M sodium sulfate. This is the first time that the formation of a CH-π interaction has been directly monitored during the folding of a protein.