Ratio Of Specific Activity Research Articles

Survival and mitochondrial function in septic patients according to mitochondrial DNA haplogroup

IntroductionWe recently found that platelet cytochrome c oxidase (COX) activities and quantities in 6-month-survival septic patients are significantly higher than those of patients who died before 6 months. Other studies suggested that the mitochondrial DNA (mtDNA) genotype could play a major role in sepsis survival. Given that COX catalytic subunits are encoded by mtDNA, the objective of the present study was to explore whether mtDNA population genetic variation could affect COX activity and quantity and favors sepsis survival.MethodsA prospective, multicenter, observational study was carried out in six Spanish ICUs. We included 96 patients with severe sepsis. We determined the mtDNA haplogroup, the COX specific activity/citrate synthase specific activity (COXa/CSa) ratio and the COX quantity/citrate synthase specific activity (COXq/CSa) ratio in circulating platelets at the time of diagnosis, day 4 and day 8. We used survival at 1 and 6 months as endpoints.ResultsPatients with the JT mtDNA haplogroup (n = 15) showed higher COXq/CSa ratio at day 4 (P = 0.04) and day 8 (P = 0.02) than those with other haplogroups (n = 81). Logistic regression analysis showed that the JT mtDNA haplogroup (odds ratio = 0.18; 95% confidence interval = 0.04 to 0.94; P = 0.04) and COXq/CSa ratio (odds ratio = 0.53; 95% confidence interval = 0.30 to 0.93; P = 0.03) were associated with 1-month survival after controlling for age and lactic acid levels.ConclusionsThe novel findings of our study are that 1-month surviving septic patients showed higher COXq/CSa ratio than nonsurviving individuals, that patients from the JT mtDNA haplogroup showed a higher COXq/CSa ratio and that JT patients had a higher 1-month survival than patients from other mtDNA haplogroups.

Entrapment of enzymes into cellulose–biopolymer composite hydrogel beads using biocompatible ionic liquid

Abstract For the first time, lipase from Candida rugosa was successfully entrapped into various cellulose–biopolymer composite hydrogels by using a biocompatible ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]). Lipase-entrapped cellulose and cellulose–biopolymer composite hydrogel beads were simply prepared by co-dissolution of biopolymers in [Emim][Ac] and dispersion of lipase in biopolymer solution followed by formation of biopolymer hydrogel using distilled water. Immobilization yields (specific activity ratio of entrapped lipase to free lipase) of cellulose, cellulose–carrageenan, cellulose–chitosan, cellulose–agarose, and cellulose–agar bead were 35.0, 9.6, 39.7, 41.4, and 52.6%, respectively. Cellulose–biopolymer composite hydrogels proved to be good supports for entrapment of enzymes and have many potential applications, including drug delivery, biosensors, biofuel cells, and tissue engineering due to their inherent excellent biocompatibility and biodegradability.

Studies on the rain scavenging process of tritium in a tropical site in India

This study presents the results of one of the first systematic experiments on tritium ( 3H) concentrations in ground level air against that in rainwater near a pressurized heavy water reactor in a tropical region. The samples were collected over the rainy season of three years (2007, 2008 and 2010). For this study, 31 data sets were collected and interpreted based on the theoretical information available in the literature. The specific activity ratio of 3H between rainwater and air moisture at ground level was calculated for each data set. The average specific activity ratio was found to be 1.96 ± 2.72. A correlation ( r = 0.82, p < 0.001) was observed between the total rain hours in a day and the rainwater 3H activity. Higher rain duration with slower rain rate yielded higher 3H concentrations as more time was available for the scavenging/wash out process to take effect together with lower dilution. The present data also suggested the need to further investigate the influence of raindrop distribution and other local meteorological parameters on the 3H wash out process. An attempt was also made to predict the 3H concentration in air moisture samples using a Gaussian plume dispersion model and the values were compared with the measured 3H activity. The measured values were generally lower than the predictions.

Specific activity and activity ratios of radionuclides in soil collected about 20 km from the Fukushima Daiichi Nuclear Power Plant: Radionuclide release to the south and southwest

Soil samples at different depths (0–2, 5–7 and 10–12 cm) were collected from J Village, about 20 km south of Fukushima Daiichi Nuclear Power Plant (FNPP) to determine their radionuclide specific activities and activity ratios. The concentrations and activity ratios of 131I, 134, 136, 137Cs and 129mTe were obtained, but only trace amounts of 95Nb, 110mAg and 140La were detected which were too low to provide accurate concentrations. Radionuclides such as 95Zr, 103, 106Ru and 140Ba that were found in Chernobyl fallout, were not found in these soil samples. This suggests that noble gasses and volatile radionuclides predominated in the releases from FNPP to the terrestrial environment. The average activity ratios of 131I/ 137Cs, 134Cs/ 137Cs, 136Cs/ 137Cs and 129mTe/ 137Cs were 55, 0.90, 0.22 and 4.0 (corrected to March 11, 2011) in the 0–2 cm soil samples of April 20 and 28, 2011.

Environmental transportation of tritium and estimation of site-specific model parameters for Kaiga site, India

Tritium content in air moisture, soil water, rain water and plant water samples collected around the Kaiga site, India was estimated and the scavenging ratio, wet deposition velocity and ratio of specific activities of tritium between soil water and air moisture were calculated and the results are interpreted. Scavenging ratio was found to vary from 0.06 to 1.04 with a mean of 0.46. The wet deposition velocity of tritium observed in the present study was in the range of 3.3E-03 to 1.1E-02 m s(-1) with a mean of 6.6E-03 m s(-1). The ratio of specific activity of tritium in soil moisture to that in air moisture ranged from 0.17 to 0.95 with a mean of 0.49. The specific activity of tritium in plant water in this study varied from 73 to 310 Bq l(-1). The present study is very useful for understanding the process and modelling of transfer of tritium through air/soil/plant system at the Kaiga site.

Kinetic Analysis of β-Galactosidase and β-Glucuronidase Tetramerization Coupled with Protein Translation

Both β-galactosidase (GAL) and β-glucuronidase (GUS) are tetrameric enzymes used widely as reporter proteins. However, little is known about the folding and assembly of these enzymes. Although the refolding kinetics of GAL from a denatured enzyme have been reported, it is not known how the kinetics differ when coupled with a protein translation reaction. Elucidating the assembly kinetics of GAL and GUS when coupled with protein translation will illustrate the differences between these two reporter proteins and also the assembly process under conditions more relevant to those in vivo. In this study, we used an in vitro translation/transcription system to synthesize GAL and GUS, measured the time development of the activity and oligomerization state of these enzymes, and determined the rate constants of the monomer to tetramer assembly process. We found that at similar concentrations, GAL assembles into tetramers faster than GUS. The rate constant of monomer to dimer assembly of GAL was 50-fold faster when coupled with protein translation than that of refolding from the denatured state. Furthermore, GAL synthesis was found to lack the rate-limiting step in the assembly process, whereas GUS has two rate-limiting steps: monomer to dimer assembly and dimer to tetramer assembly. The consequence of these differences when used as reporter proteins is discussed.

Salinity regulates N-methylation of phosphatidylethanolamine in euryhaline crustaceans hepatopancreas and exchange of newly-formed phosphatidylcholine with hemolymph

Phosphatidylcholine (PC), the main phospholipid in eukaryotes, is synthesized via two different routes, the phosphatidylethanolamine N-methyl transferase (PEMT) and the CDP-choline pathways. We previously showed in euryhaline fish that salinity impacts the relative contribution of the two pathways for PC biosynthesis, with PEMT pathway being activated in the liver of sea water (SW)-adapted animals. To address the occurrence of such phenomenon in other animals we performed in vivo metabolic studies in two crustacean species: the Chinese crab (Eriocheir sinensis) and the green crab (Carcinus maenas). In both species, the levels of PC and phosphatidylethanolamine in hepatopancreas and hemolymph were not modified by SW-adaptation. In E. sinensis, SW-adaptation activated PC labeling from L-(U-(14)C)-serine in the hepatopancreas and resulted in an increased ratio of PC specific activities between hemolymph and hepatopancreas. In C. maenas, incorporation of L-(3-(3)H)-serine and L-(2-(14)C)-ethanolamine into PC of hepatopancreas was strongly inhibited after acclimation to fresh water (FW). The results show that PC synthesis via the PEMT pathway and its subsequent release into hemolymph are both activated in SW- compared to FW-adapted animals. SW-adaptation also resulted in increased tissue concentrations of betaine and labeling from L-(U-(14)C)-serine, suggesting that the PEMT-derived PC is used for the synthesis of organic osmolytes. The physiological relevance of these observations is discussed.

Retrospective determination of 137Cs specific activity distribution in spruce bark and bark aggregated transfer factor in forests on the scale of the Czech Republic ten years after the Chernobyl accident

The 137Cs specific activities (mean 32 Bq kg −1) were determined in spruce bark samples that had been collected at 192 sampling plots throughout the Czech Republic in 1995, and were related to the sampling year. The 137Cs specific activities in spruce bark correlated significantly with the 137Cs depositions in areas affected by different precipitation sums operating at the time of the Chernobyl fallout in 1986. The ratio of the 137Cs specific activities in bark and of the 137Cs deposition levels yielded bark aggregated transfer factor T ag about 10.5 × 10 −3 m −2 kg −1. Taking into account the residual specific activities of 137Cs in bark 20 Bq kg −1 and the available pre-Chernobyl data on the 137Cs deposition loads on the soil surface in the Czech Republic, the real aggregated transfer factor after and before the Chernobyl fallout proved to be T* ag = 3.3 × 10 −3 m −2 kg −1 and T** ag = 4.0 × 10 −3 m −2 kg −1, respectively. The aggregated transfer factors T* ag for 137Cs and spruce bark did not differ significantly in areas unequally affected by the 137Cs fallout in the Czech Republic in 1986, and the figures for these aggregated transfer factors were very similar to the mean bark T ag values published from the extensively affected areas near Chernobyl. The magnitude of the 137Cs aggregated transfer factors for spruce bark for the pre-Chernobyl and post-Chernobyl period in the Czech Republic was also very similar. The variability in spruce bark acidity caused by the operation of local anthropogenic air pollution sources did not significantly influence the accumulation and retention of 137Cs in spruce bark. Increasing elevation of the bark sampling plots had a significant effect on raising the remaining 137Cs specific activities in bark in areas affected by precipitation at the time when the plumes crossed, because the sums of this precipitation increased with elevation (covariable).

Optimization of the covalent coupling and ionic adsorption of magnetic nanoparticles on Flavobacterium ATCC 27551 using the Taguchi method

Flavobacterium ATCC 27551 was used as a model system for the preparation of magnetic biocatalysts. The magnetic modification was carried out by covalently binding carboxylate- and amino-modified magnetic nanoparticles onto cells. Magnetic Fe3O4 nanoparticles were also used for ionic adsorption on the cell surface. Magnetically modified cells were concentrated using a magnet and exhibited organophosphate hydrolyzing activity. The Taguchi method was used to optimize the binding of the magnetic nanoparticles on the cell surface. SEM image analyses demonstrated good linkage of the magnetic nanoparticles over the Flavobacterium ATCC 27551 cell surface. Under optimal conditions, the magnetic cells displayed specific activity ratios of 93%, 89% and 95%, compared with untreated cells, after the covalent coupling with carboxylate- and amino-modified magnetic nanoparticles and the ionic adsorption of magnetic Fe3O4 nanoparticles, respectively.

Development of an amphiphilic matrix for immobilization of Candida antartica lipase B for biodiesel production

Biodiesel has been greatly interested as an alternative fuel and is produced by a transesterification reaction of oil with alcohol. Recently, microbial lipases have been used for biodiesel production. Among the microbial lipase, immobilized Candida antartica lipase B (CALB) is the most widely used. However, CALB is unstable and shows low catalytic efficiency in the reaction media because the reaction media contains a high concentration of methanol and the lipase is also inhibited by the by-product glycerol. In this study, to overcome these limitations, we developed an amphiphilic matrix to immobilize CALB. The immobilized lipase in an amphiphilic matrix with 80% ethyltrimethoxysilane (ETMS) in tetramethoxysilane (TMOS) and pretreated with oil showed the highest specific activity and biodiesel conversion ratio; about 90% biodiesel conversion in 24 h at an initial molar ratio of 1: 1 (oil: methanol) with stepwise methanol feeding in order to adjust the net molar ratio to be 1: 3.

Modification of a 3‐d deuterated‐retinol dilution (DRD) equation for estimation of vitamin A (VA) stores in humans

Isotope dilution analysis has been successfully used to estimate vitamin A stores in humans via the Furr‐Olson DRD equation: estimated total body stores = F × dose × {S ×a × [(1/D:H) −1]} (Am J Clin Nutr 1989;49:713). The method requires a blood sample 21 d after isotope administration and involves several assumptions (factors F, S and a). Using VA tracer data from rat and human studies, we refined a modified DRD equation (J Nutr 2008; 138:971) that uses a 3‐d sample, a time that is more feasible in the field. We found that the VA specific activity ratio in plasma vs. stores (factor S in DRD equation) varies with VA status in both rats and humans. Also, the amount of tracer irreversibly lost between dose administration and blood sampling (factor a) increases as status decreases. In contrast, retention (factor F) increases as status increases. Applying these findings to the original DRD equation, we developed a new equation in which S, F, and a vary with a subject's 3‐d plasma VA deuterium:hydrogen (D:H) ratio. For data from humans of varying age, gender and ethnicity, VA stores predicted by the new equation agree better with estimates from the original 21‐d Furr‐Olson equation than do values obtained using other published 3‐d DRD equations. Thus the new equation provides an improved tool to determine VA stores in humans.Funded by the College of Health and Human Development, Penn StateGrant Funding Source: The College of Health and Human Development

A method of estimating residence time of atmospheric aerosol and its preliminary experimental verification

A method of estimating residence time of atmospheric aerosol (RTAA) is established based on the relationship between specific activity ratio of radon daughters in atmospheric particles and average life of the particles. The method is further testified in a standard radon chamber. When specific activity of radon is 1.816 kBq/m3 in the chamber,the RTAA is estimated to be 112.17 min,which is in agreement with the mean-ventilation time in the chamber,104.17 min. Therefore,the residence time of the atmospheric aerosol can be estimated by using the specific activity ratios of radionuclide in the same decay chain,such as 214Bi/214Pb, 210Bi/210Pb and 210Po/210Pb.

Thymoquinone enhances the activities of enzymes related to energy metabolism in peripheral leukocytes of diabetic rats

The aim of this study was to examine the effect of glycemic control using thymoquinone (TQ) on energy metabolism related enzymes in leukocytes of streptozotocin (STZ)-induced diabetic rats. The treatment of both TQ and insulin commenced 4weeks after induction of diabetes. Plasma glucose, cholesterol and triglycerides levels were significantly reduced after TQ treatment, whereas immunoreactive insulin (IRI) showed significant increase. The activities of malate dehydrogenase (MDH) in cytosolic and mitochondrial fractions of peripheral blood leukocytes were significantly higher in rats treated with TQ and insulin as compared to that in diabetic controls. On the other hand the activities of lactic dehydrogenase (LDH) showed no significant changes between groups. ML ratio (cytosolic MDH/LDH specific activity ratio) was restored to those in the control rats. The results of this study demonstrate that TQ significantly increased insulin level and the activities of cytosolic and mitochondrial MDH in leukocytes of STZ-diabetic rats.

Transuranium elements in liquid radioactive wastes from the Shelter

The volume activity of 90Sr, 137Cs, 238Pu, 239+240Pu, 241Am, and 244Cm in water taken from unorganized water accumulations on lower marks of the Shelter was determined. Separate water accumulations are characterized by their specific radionuclide activity ratios 238Pu/239+240Pu, 241Am/239+240Pu, and 244Cm/241Am. The activity ratios 241Am/239+240Pu and 244Cm/239+240Pu in the water accumulations are 5–10 times higher than in the irradiated fuel of the 4th Unit of the Chernobyl NPP and in lava-like fuel-containing materials.

Regional characteristics of naturally occurring radionuclides in surface sediments of Chinese deserts and the Keum River area of Korea

Naturally occurring radionuclides (NORN) such as 40K, 226Ra and 232Th from 44 surface sediment samples collected from four desert regions of Chinese were determined to investigate the regional characteristics of the source areas of Asian dust. The radionuclides for 41 surface sediment samples collected from seven sites of the Keum River area in Korea were also determined to compare the regional characteristics with the Chinese desert area. The specific activities (SA) and the specific activity ratios (SAR) of the radionuclides were investigated for distinguishing the source region of Asian dust. The SA of 226Ra and 232Th as well as the SAR of 226Ra/40K and 232Th/40K were found to be useful to characterize source area and tracing Asian dust.

Isolation of Stable (αβ)4-Tetraprotomer from Na+/K+-ATPase Solubilized in the Presence of Short-Chain Fatty Acids

Previously, it was demonstrated that acetate anions increase the higher oligomer (H), consuming (alphabeta) 2-diprotomer (D) and alphabeta-protomer (P) of solubilized dog kidney Na (+)/K (+)-ATPase [ Kobayashi, T. et al. (2007) J. Biochem. 142, 157-173 ]. Presently, short-chain fatty acids, such as propionate (Prop) and butyrate, have been substituted effectively for acetate. The molecular weight of 6.01 x 10 (5) for H and quantitative Na (+)/K (+)-dependent interconversion among H, D, and P showed that H was an (alphabeta) 4-tetraprotomer (T). T was optimally isolated from the enzyme solubilized in aqueous 40 mM K (+)Prop at pH 5.6 by gel chromatography performed at 0 degrees C with elution buffer containing synthetic dioleoyl phosphatidylserine (PS). K 0.5 values of K (+)-congeners constituting K (+)Prop for the maximal amount of T were NH 4 (+) >> Rb (+) congruent with K (+) > Tl (+), while Na (+) had no effect. The oligomers of T, D, and P were simultaneously assayed for ATPase upon elution from the gel column, resulting in a specific activity ratio of 1:2:2. The activity of the chromatographically isolated T increased with an increasing dioleoyl PS, giving a saturated activity of 2.38 units/mg at pH 5.6 and 25 degrees C, and the active enzyme chromatography of T showed 34% dissociation into D by exposing it at 25 degrees C. On the basis of these data, the specific ATPase activities of T, D, and P were concluded to be 32, 65, and 65 units/mg, respectively, under the conventionally optimal conditions of pH 7.3 and 37 degrees C, suggesting an equivalence to a fully active enzyme for D and P but half activity for T. The physiological significance of the stable form of T remains to be investigated.

Correlations of natural radionuclides in sediment from Danube

The correlation between specific activities of some natural radionuclides ( 238U, 226Ra, 232Th, 40K) measured in sediment taken from river bottom was studied. The sediment was taken from the Serbian part of the Danube River. Good correlation between some of the isotopes is observed, so that their specific activity ratios are spread over a lower range than specific activities themselves. This suggests that evaluation of specific activity ratios of some natural radionuclides could be a more sensitive method for the determination of increased levels of some of them than the straightforward analysis of specific activities.

Activity of Circulating Proteasomes Correlates with Clinical Behavior in Patients with Chronic Myeloid Leukemia.

The ubiquitin-proteasome pathway is implicated in the pathogenesis of many malignancies and is an important regulator of cell proliferation, apoptosis, DNA repair, and the stress response. Free circulating proteasomes have been reported in the plasma and sera of cancer patients. We measured proteasome peptidase activity in the plasma of patients with chronic myeloid leukemia (CML) and correlated these findings with clinical behaviour. Plasma samples from apparently healthy volunteers (n = 92) and patients in the chronic (n = 104) or accelerated/blast phase (n = 56) of CML were analysed with fluorogenic kinetic assays. Using peptide-AMC (7-amino-4-methylcoumaran) substrates, we measured the three reported proteasome enzymatic activities: chymotrypsin-like (Ch-L), trypsin-like (Tr-L), and caspase-like (Cas-L). All proteasome activities were significantly higher in CML patients than in healthy volunteers. Extensive characterization of proteasome activities revealed correlations between levels or ratios of specific peptidase activities and disease phase, progression, aggressiveness, and survival. High Ch-L activity correlated with shorter survival in both CP (P=0.037) and Acc/Bl phase (P=0.047). Patients in CP and a ratio of Cas-L: Tr-L activity >1.48 had significantly shorter survival (P=0.03). Cas-L: Tr-L activity ratio was predictor of survival in Acc/Bl patients as a continuous variable. These findings suggest that proteasome activity in the plasma of CML patients reflects disease activity and can be used as a biomarker for predicting clinical behavior. Studies exploring the role of proteasome inhibitors in CML are therefore warranted.

Characteristics of phospholipase A 2 mutant of the starfish Asterina pectinifera

Site-directed mutagenesis study of phospholipase A 2 (PLA 2) from the pyloric ceca of starfish Asterina pectinifera was used to probe the relationship between polar-group specificity and structure of the pancreatic loop region. The sequence of the cDNA encoding the starfish PLA 2 was exchanged by the oligonucleotide-directed dual amber-long and accurate polymerase chain reaction method to insert Lys residue between Cys-62 and Gly-63. The modified cDNA was inserted into the expression plasmid pET-16b, and PLA 2 mutant was expressed in Escherichia coli Origami™ B (DE3) by induction with isopropyl-beta- d(−)-thiogalactopyranoside. The starfish PLA 2 mutant showed essentially the same properties as the starfish native PLA 2 with respect to substrate positional specificity, optimum pH, optimum temperature, Ca 2+ requirement, and sodium deoxycholate requirement. However, the specific activity of the starfish PLA 2 mutant for egg yolk PC (950 U/mg) was extremely lower than that of native PLA 2 (119,000 U/mg), but close to that of porcine pancreatic PLA 2 (4300 U/mg). Moreover, the ratio of specific activity of the PLA 2 mutant for phosphatidylcholine to phosphatidylethanolamine (98 times) was highly lower than that of native PLA 2 (2650 times), but similar to that of porcine pancreatic PLA 2 (25 times). Therefore, it was suggested that the charge and structure of pancreatic loop region of the starfish PLA 2 might carry out important role on polar-group specificity.

Prompt gamma tomography during BNCT—a feasibility study

The success of clinical boron neutron capture therapy (BNCT) lies in the ability to manage the radiobiological effect on the tumour and healthy tissue, and thus, accurate dosimetry measurements is pertinent for each individual patient. In the present work we investigate the possibility of performing online prompt gamma tomography (PGT) during BNCT. A prototype detector system was constructed, which is in principle a pin-hole collimator with a HPGe crystal to be mounted on a C-bow device, with shielding of lithium-plastic and lead. The detector system was used to measure on a phantom placed in an epithermal neutron beam and on a 137Cs-source. The possibility of tomographic reconstruction using the detector system was tested on a phantom filled with a 131I-solution with a smaller sphere inserted containing a higher specific activity (ratio 10:1). The detector system was possible to operate up to about 6 × 108 cm−2 s−1 thermal neutron fluence at the peak in the phantom, at which time it was saturated. A 478 keV boron-peak was visible in the measured spectra but the signal-to-noise-ratio was rather low. No post-irradiation damage or neutron activation was detectable. A tomographic reconstruction of the phantom filled with 131I-solutions was performed using an algorithm developed in house and based on the MLEM method. The image quality is fairly good and the results provide a clear indication that the detector system can be used to obtain data that enables tomographic reconstruction. A spatial resolution of the detector system of about 2 cm was obtained from both the measurement on the 137Cs-source and the 131I-phantom. In conclusion, the presented feasibility study on a prototype PGT system is encouraging further studies specifically directed at improving the signal-to-noise-ratio in measurements in epithermal neutron beams.