Characteristics of the "no-reflow" phenomenon in reperfusion of the myocardium depending upon the duration of ischemia

The dynamics of changing dimensions of "no reflow" area following reperfusion after 30 min-1 h-long ischemia is characterized by three basic phases. The reperfusion following and hour-long ischemia altered considerably the character of phases of "no reflow" phenomenon. The data obtained suggest that the therapy of transitory ischemia must be directed not only to ischemia itself, but also to postischemia reperfusion-induced "no reflow" phenomenon.     

A Tuberculin Skin Test Survey and the Annual Risk of Mycobacterium tuberculosis Infection in Gambian School Children

Background

A Tuberculin skin test (TST) survey was conducted to assess the prevalence of latent TB Infection (LTBI) and to estimate the annual risk of M. tuberculosis infection (ARTI) in Gambian school children. The results are expected to contribute to understanding of Tuberculosis epidemiology in The Gambia.

Methods

This was a nationwide, multi-cluster survey in children aged 6–11 years. Districts, 20 of 37, were selected by probability proportional to size and schools by simple random sampling. All TST were performed using the Mantoux method. Height and weight measurements were obtained for all participants. We calculated prevalence of LTBI using cut-off points of 10mm, the mirror and mixture modelling methods.

Results

TST readings were completed 13,386 children with median age of 9 years (interquartile range [IQR] 8–10 years). Mixture analysis yielded a cut-off point of 12 mm, and LTBI prevalence of 6.9% [95%CI 6.47–7.37] and the ARTI was 0.75% [95%CI 0.60–0.91]. LTBI was associated gender and urban residence (p <0.01). Nutritional status was not associated with non-reactive TST or sizes of TST indurations. ARTI did not differ significantly by age, gender, BCG vaccination or residence.

Conclusions

This estimates for LTBI prevalence and ARTI were low but this survey provides updated data. Malnutrition did not affect estimates of LTBI and ARTI. Given the low ARTI in this survey and the overlapping distribution of indurations with mixture modelling, further surveys may require complementary tests such as interferon gamma release assays or novel diagnostic tools.     

Kinetics and thermodynamics of a novel endoglucanase (CMCase) from <Emphasis Type="Italic">Gymnoascella </Emphasis><Emphasis Type="Italic">citrina</Emphasis> produced under solid-state condition

Gymnoascella citrina produced two isoforms of endoglucanases (CMCase-I and -capital I, Ukrainiancapital I, Ukrainian) under solid-state condition. Purified CMCase-I was novel because it was apparently holoenzyme in nature. The enzyme was monomeric as its native and subunit mass were almost the same, i.e., 43 and 42 kDa, respectively. Ea for carboxymethylcellulose (CMC) hydrolysis was 36.2 kJ mol(-1). The enzyme was stable over a pH range of 3.5-6.5, while temperature optimum was 55 degrees C. Vmax, Km and k (cat )for CMC hydrolysis were 39 U mg(-1) protein, 6.25 mg CMC mL(-1) and 27.5 s(-1), respectively. The pKa1 and pKa2 of ionizable groups of active site were 2.8 and 7.4, respectively. Thermodynamic parameters for CMC hydrolysis were as follows: DeltaH*=33.5 kJ mol(-1), DeltaG*=70.42 kJ mol(-1) and DeltaS*=-114.37 J mol(-1) K(-1). The removal of metals resulted into complete loss of enzymatic activity and was completely recovered in the presence of 1 mM Mn2+, whereas inhibition initiated at 5 mM. The other metals like Ca2+, Zn2+ and K1+ showed no inhibition up to 7 mM, Co2+ completely inhibited the activity, while Mg2+ could not recover the initial activity up to 7 mM. So we are reporting for the first time, kinetics and thermodynamics of CMCase-Iota from G. citrina.     

Effect of host plant on cornucopia of mango fruit flies (Diptera: Tephritidae) and their triumphant management in context of climate change

A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., ‘Dusehri’, ‘Malda’, ‘Langra’ early cultivars, ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ medium whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’, ‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like ‘Sanglakhi’ (20.61 percent), ‘Mehmood Khan’ (20.22 percent) and ‘Reutal-12’ (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar ‘Reutal-12’ was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on ‘Reutal-12’ for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango.     

Genetic analysis ofCochliobolus heterostrophus polyoxin-resistant mutants

Nine polyoxin-resistant mutants ofCochliobolus heterostrophus were isolated after ethyl methanesulphonate mutagenesis. All were highly resistant to polyoxin (MIC≥1,600 ppm). Crosses between the mutants and a wild-type strain revealed that the resistance trait was inherited to the offsprings in different fashions. Four of the mutant strains inherited polyoxin resistance in a 1∶1 segregation ratio, indicating that the phenotypes in these strains were due to alteration at a single locus. Allelism tests revealed four new loci,Pol1, Pol2, Pol3 andPol4, for polyoxin resistance in these mutant strains. The genes responsible for the phenotypes of the other five mutant strains were not determined, because of extremely slow growth of progenies in one cross, sterility in another cross, and inexplicable responses to polyoxin of the progenies in the other crosses. No linkage was detected between the genes for polyoxin resistance and mating type.     

Oral Ingestion of Transgenic RIDL Ae. aegypti Larvae Has No Negative Effect on Two Predator Toxorhynchites Species

Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered ‘sterile’ homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment.     

Slow Regulated Release of H2S Inhibits Oxidative Stress Induced Cell Death by Influencing Certain Key Signaling Molecules

Hydrogen sulphide (H₂S) is one of three gaseous signaling molecules after nitric oxide and carbon monoxide. Various H₂S donor compounds have been synthesized to study its physiological function. Among these compounds sodium hydrosulphide (NaHS), a donor of releasing H₂S rapidly have shown to be protective in certain neuronal cell line but several in vivo studies have generated conflicting data. Furthermore several slow releasing H₂S donors have been shown to have positive effects on cells in culture. The intracellular concentration of H₂S and hence its rate of production may be a factor in keeping the balance between its neuroprotective and toxic effects. The present study was undertaken to deduce how a rapid releasing H₂S donor (NaHS) as opposed to a slow releasing donor (ADTOH), affect oxidative stress related intracellular components and survival of RGC-5 cells. It was concluded that when RGC-5 cells are exposed to the toxic effects of glutamate in combination with buthionine sulfoxime (Glu/BSO), ADTOH was more efficacious in inhibiting apoptosis, scavenging reactive oxygen species (ROS), stimulation of glutathione (GSH) and gluthathione-S-transferase (GST). Western blot and qPCR analysis showed ADTOH increased the levels of Nrf2, HO-1, PKCα, p-Akt, Bcl-2 and XIAP but caused a decrease of Nfκβ and xCT greater than NaHS. This study is first to compare the efficacy of two H₂S donor drugs as potential neuroprotectants and demonstrate that slow regulated release of H₂S to cell culture can be more beneficial in inhibiting oxidative stress induced cell death.     

Reliable structural information for rational design of benzoxazole type potential cholesteryl ester transfer protein (CETP) inhibitors through multiple validated modeling techniques

Abstract

The drug design and discovery of lipid modulators is very demanding as no new molecule has entered into the market in the last 35 years. Cholesteryl ester transfer protein (CETP) is a promising target as lipid modulators. Inhibition of the CETP enzyme reduces the risk of cardiovascular events. The first CETP inhibitor torcetrapib and related drug candidates failed in the clinical trial due to the off-target effects leading to high toxicity. Thus, newer CETP inhibitors have now paramount importance to accelerate the drug discovery efforts in the field of cardiovascular disease (CVD). In the present study, 140 benzoxazole compounds were studied by using different chemometric techniques, for example, pharmacophore mapping, molecular docking, three-dimensional quantitative structure–activity relationship comparative molecular field analysis (3D-QSAR CoMFA), topomer CoMFA and Bayesian classification, in order to generate complete and reliable information regarding the structural requirements for the CETP inhibition. The best pharmacophore hypothesis was statistically significant (regression coefficient of 0.957 and a lower root mean square of 0.890). Molecular docking study revealed that cyano-substituted compounds form hydrogen bond with targeted macromolecule. The 3D-QSAR CoMFA model also produced a leave-one-out (LOO) cross-validated Q² of 0.527, an R² of 0.853 and an R²_Pred of 0.603. Similarly, two topomer CoMFA models were also statistically significant and reliable in terms of their Q², R² and R²_Pred values. The Bayesian classification study also provided the excellent ROC values of 0.919 and 0.939 for training and test sets, respectively. Overall, this study may help in the rational design of newer benzoxazole type compounds with higher CETP inhibition.

Communicated by Ramaswamy H. Sarma     

Determination of iodide using flow injection with acidic potassium permanganate chemiluminescence detection.

A simple and rapid flow-injection method is described for the determination of iodide, based on potassium permanganate chemiluminescence detection via oxidation of formaldehyde in aqueous hydrochloric acid. The calibration graph was linear over the range 1.0-12 x 10(-6) mol/L (r2 = 0.9955) with relative standard deviations (n = 4) in the range 1.0-3.5%. The detection limit (3sigma) was 1.0 x 10(-7) mol/L, with sample throughput of 120/h. The effect of interfering cations [Ca(II), Mg(II), Ni(II), Fe(II), Fe(III) and Pb(II)] and anions (Cl-, SO4(2-), PO4(3-), NO3-, NO2-, F- and SO3(2-)) were studied. The method was applied to iodized salt samples and the results obtained in the range 0.03 +/- 0.005 - 0.10 +/- 0.006 mg I/g were in reasonable agreement with the amount labelled. The method was statistically compared with the results obtained by titration; no significant disagreement at 95% confidence was observed.     

Substrate specificity and biochemical properties of M3.BstF5I DNA methyltransferase from the BstF5I restriction-modification system

Optimal conditions for DNA methylation by the M3.BstF5I enzyme from Bacillus stearothermophilus and kinetic parameters of λ phage DNA modification and that of a number of oligonucleotide substrates are established. Comparison of M1.BstF5I and M3.BstF5I kinetic parameters revealed that with similar temperature optima and affinity for DNA, M3.BstF5I has nearly fourfold lower turnover number (0.24 min⁻¹) and modifies the hemimethylated recognition site with lower efficiency under optimal conditions than the unmethylated one. In contrast to another three methylases of the BstF5I restriction-modification system, the M3.BstF5I enzyme is able to optionally modify the noncanonical 5′-GGATC-3′ DNA sequence with a rate more than one order of magnitude lower than the methylation rate of the canonical 5′-GGATG-3′ recognition site.