Free radical scavenging and metal chelation by Tinospora cordifolia,a possible role in radioprotection

Aqueous extract of T. cordifolia inhibited Fenton (FeSO4) reaction and radiation mediated 2-deoxyribose degradation in a dose dependent fashion with an IC50 value of 700 microg/ml for both Fenton and radiation mediated 2-DR degradation. Similarly, it showed a moderate but dose dependent inhibition of chemically generated superoxide anion at 500 microg/ml concentration and above with an IC50 value of 2000 microg/ml. Aqueous extract inhibited the formation of Fe2+-bipiridyl complex and formation of comet tail by chelating Fe2+ ions in a dose dependent manner with an IC50 value of 150 microg/ml for Fe2+-bipirydyl formation and maximally 200 microg/ml for comet tail formation, respectively. The extract inhibited ferrous sulphate mediated lipid peroxidation in a dose-dependent manner with an IC50 value of 1300 microg/ml and maximally (70%) at 2000 microg/ml. The results reveal that the direct and indirect antioxidant actions of T. cordifolia probably act in corroboration to manifest the overall radioprotective effects.     

Distribution,occurrence and characterization of entomopathogenic fungi in agricultural soil in the Palestinian area

The occurrence of entomopathogenic fungi was investigated in irrigated vegetable fields and citrus orchards soils, over a nine-month period (April-December 1999), using the Galleria bait method (GBM). Entomopathogenic fungi were found to occur in 33.6% of the soil samples studied, with positive samples yielding 70 fungal isolates, belonging to 20 species from 13 genera. Conidiobolus coronatus was the most frequent and abundant entomopathogenic species recovered, comprising 31.4% of the total number of isolates. Soil pH, soil moisture content and the geographical location had minor or no effect on the isolation of entomopathogenic fungi in the fields studied. On the other hand, organic matter content of soil, and vegetation type were found to significantly affect the occurrence of entomopathogenic fungi in soil habitats, with orchard fields yielding larger numbers of isolates than vegetable fields. Using Koch's postulates the pathogenicity of fungal isolates to Galleria larvae was found to range from 16-100% (mortality rate). Isolates of C. coronatus proved to be the most virulent isolates recovered. The effect of media and temperature on mycelial growth rate, conidial production and conidial germination of six entomopathogenic fungal species (C. coronatus, Entomophaga grylli, Erynia castrans, Hirsutella jonesii, Paecilomyces farinosus and Sporodiniella umbellata) was also studied. Mycelial growth rate, spore production and spore germination were significantly affected by media, temperature and isolates. In view of the present results, C. coronatus appears to be a good candidate for pest control in agricultural soils, as it has a wide tolerance to agricultural practices, has frequently been isolated from both vegetable and orchard fields, and is characterized by high mycelial growth rate, conidial production and conidial germination.     

Lack of both oxygen and glucose contributes to I/R-induced changes in cardiac SR function

Although ischemia-reperfusion(I/R) has been shown to depress cardiac performance and sarcoplasmicreticulum (SR) function, the mechanisms underlying these alterationsare poorly understood. Because lack of oxygen and substrate deprivationare known to occur during the ischemic phase, we examined theeffects of reperfusion on cardiac performance and SR function in heartssubjected to hypoxia and substrate lack. For this purpose, isolated rathearts were perfused with hypoxic and/or glucose-free medium for 30 min and then reperfused with normal medium for 1 h; the SR vesicles were isolated for studying the Ca²⁺-transport activities.Reperfusion with normal medium of hearts deprived of oxygen or glucoseshowed no changes in cardiac performance and SR function. However,reperfusion of hearts perfused with hypoxic glucose-free medium showed~45% decrease in cardiac contractile activities as well as 23 and64% reduction in SR Ca²⁺-uptake andCa²⁺-release activities, respectively, without any changein the level of SR Ca²⁺-cycling proteins. Depressed SRfunction in these hearts was associated with a reduction inCa²⁺/calmodulin-dependent protein kinase (CaMK)phosphorylation of the SR Ca²⁺-cycling proteins and 34%decrease in SR CaMK activity. These changes in cardiac performance, SRfunction, and SR CaMK activity in the hypoxic, glucose-deprived,reperfused hearts were similar to those observed in hearts subjected to30 min of global ischemia and 60 min of reperfusion. Theresults therefore suggest that the lack of both oxygen and substrateduring the ischemic phase may contribute to the I/R-inducedalterations in cardiac performance and SR function. Furthermore, theseabnormalities were associated with reduced SR CaMK activity.

     

P‐4TRANSFORMATION ZONE COMPONENT IN LIQUID BASED CERVICAL CYTOLOGY

Introduction: Quality assurance guidelines for the UK cervical screening programme recommend that more than 80% of cervical samples from women aged 20–50 years should contain adequate numbers of Transformation zone (TZ) cells i.e. 10 or more endocervical or squamous metaplastic cells. This study was conducted to assess the frequency of TZ component in Liquid Based Cytology (LBC) both for ThinPrep (TP) and SurePath (SP) LBC. Also to assess the degree to which this is recorded by individual screeners and to determine the percentage of samples with evidence of TZ component for the different smear takers. Method: All LBC cervical specimens received at a tertiary cytology centre in the year 2004 from women aged 20–50 years were included in the study. Evidence of TZ sampling was recorded as: TP = TZ present (10 or more TZ cells)TA = TZ absentTS = TZ scanty (less than 10 TZ cells)TN = atrophic smears, TZ cells not recognisable Results: The total number of LBC cervical cases was 7445. TP = 4300 (mostly primary care) and SP = 3145 (mostly colposcopy). Overall TZ sampling rate in LBC was 82%. TP = 77.17%; SP = 88.24%. When scanty TZ was included, the standard was met for both systems (TP = 93.7%; SP = 88.24%). Presence/absence of TZ component was recorded in 6370 cases (85.1%); range 0%–97.79%. 56.7% of smear takers achieved the minimum standard for TZ sampling. Discussion: The percentage of ThinPrep samples containing adequate TZ cells was 77.17% compared to SurePath, which was 88.24%. This may be due to different patient populations i.e. primary care versus colposcopy. Screeners recorded TZ sampling in approximately 85% of samples. 56.7% of smear takers met the standard for TZ sampling.     

Tailoring the Field Distribution of ZnO by Polyaniline for SPR-Based Fiber Optic Detection of Hardness of the Drinking Water

Due to the industrial development, drinking water is getting polluted by disposing several waste products of the industries. Hardness is one of the prominent impurities in drinking water which is mainly due to the presence of carbonate and bicarbonate ions (CO₃ ^2? and HCO₃ ^?) in it. Here, we present the synthesis of the zinc oxide (ZnO) and polyaniline (PANI) nanocomposite for the detection and estimation of hardness of the drinking water. The chemical formula of such a nanocomposite is defined in terms of the fraction of polyaniline nanoparticles reinforced in ZnO matrix and is derived as ZnO_(1???x)PANI _x (0?≤?x?≤?0.9); x is the composition ratio. Silver and ZnO_(1???x)PANI _x layers are coated over the unclad core of the optical fiber so as to create the four layer system as that of Kretschmann configuration SPR structure. The working principle involves the change in dielectric constant of (ZnO_(1???x)PANI _x ) by CO₃ ^2? or HCO₃ ^? ions in aqueous atmosphere. Due to the strong interaction of the sensing surface to the CO₃ ^2? and HCO₃ ^? ions, a red shift in the SPR spectrum is observed in the concentration range 0–200 μg/l. The sensitivity of the sensor depends on the composition ratio of the nanocomposite and has been found to be maximum for the composition ratio lying in the range 0.45–0.60. This has been further confirmed in terms of the enhancement of the electric field density and found to be in agreement with the experimental value. The sensitivity of the sensor with optimum value of the composition ratio is 0.094 and 0.065 nm/(μg/l) for CO₃ ^2? and HCO₃ ^?, respectively. The sensor is highly selective to CO₃ ^2? and HCO₃ ^?. The sensor has advantages of online monitoring and remote sensing of water quality because the probe is fabricated over an optical fiber.     

A possible role for glucose metabolites in the regulation of inositol-1,4,5-trisphosphate 5-phosphomonoesterase activity in pancreatic islets

Rat pancreatic islets demonstrate inositol-1,4,5-trisphosphate 5-phosphomonoesterase activity which is 3 times higher than that in the exocrine pancreas. This enzyme has several features in common with the erythrocyte and hepatocyte enzymes: it is located primarily in the plasma membrane, it has a similar Km for inositol trisphosphate (IP3) (16 microM), and it requires Mg2+. The activity of the islet enzyme is inhibited by several diphosphorylated glucose metabolites: 2,3-bisphosphoglycerate, fructose 1,6-bisphosphate, fructose 2,6-bisphosphate, and glucose 1,6-bisphosphate. Monophosphorylated and unphosphorylated metabolites have little or no effect on its activity. Several reports show that stimulation of islets with glucose raises the concentrations of various glucose metabolites including fructose 1,6-bisphosphate, glucose 1,6-bisphosphate, and 2,3-bisphosphoglycerate to concentrations that are in the range that inhibit the islet inositol-1,4,5-trisphosphate 5-phosphomonoesterase. Other reports show that IP3 mobilizes calcium when added to permeabilized insulin-secreting cells. It is possible that the increase in cytosolic calcium known to occur during glucose-induced insulin secretion may be sustained in part by higher IP3 levels resulting from the inhibition of inositol-1,4,5-trisphosphate 5-phosphomonoesterase by some of the diphosphorylated glucose metabolites.     

Phosphatidylinositol kinase in rat pancreatic islets: subcellular distribution and sensitivity to calcium

Plasma membrane of pancreatic islets contains a calcium sensitive phosphatidylinositol kinase. This enzyme catalyzes the first reaction in the pathway leading to the production of inositol trisphosphate, which is believed to cause a redistribution of intracellular calcium. Since the activity of this enzyme is inhibited by calcium (K0.5 = 10 microM), a loss of calcium from plasma membrane (the site of PI kinase) may be necessary for activation of the enzyme in vivo.     

Effect of soil salinity and soil water availability on growth and chemical composition ofSorghum halepense L.

Summary Effects of soil salinity and soil water regime on growth and chemical composition ofSorghum halepense L. was studied with a view to evaluating its potential as a forage crop in saline soils. The experiment was conducted under controlled conditions using pot-culture with three levels of soil salinity (EC_e 0.5, 5.0, 10.0 ds/m) and three soil water regimes (60%, 40% and 20% of water holding capacity of the soil). High soil salinity and low soil water combiningly had an adverse effect on plant growth but the biomass production was appreciably high (57 to 75% of control) even under high soil salinity (EC_e 10 ds/m) when sufficient water was available. Belowground plant parts were relatively more salt-tolerant than shoots. There occurred an increase in the concentration of certain nutrients (N, Ca, Mg, TNC) in the plants in response to salinity, which along with increased root: shoot ratios was inferred as an adaptive feature of the plant for persistence under saline conditions.