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Specific Activity (specific + activity)
Kinds of Specific Activity Selected AbstractsClarification of Citrus Juice is Influenced by Specific Activity of Thermolabile Pectinmethylesterase and Inactive PME-Pectin ComplexesJOURNAL OF FOOD SCIENCE, Issue 7 2002J. Ackerley ABSTRACT: Thermolabile pectinmethylesterase (PME) from Valencia orange pulp was extracted, partially purified by cation exchange chromatography (IEX), and added to reconstituted orange juice at 2 units/ml. Of the juices that clarified, %T increased, cloud particle size increased and % degree of esterification (DE) decreased in the 15 d storage study. The rate of clarification was most rapid for juices with added PME extracts that never bound Hi-Trap SP and contained 36 and 27 kDa peptide, intermediate for crude extracts of PME not applied to IEX, and lowest for PME extracts that bound Hi-Trap SP and contained 36 and 13 kDa peptide. These results suggest that PME-pectin complexes and low peptides moderate PME activity and juice clarification. [source] Electrochemical Quartz Crystal Microbalance Studies on Enzymatic Specific Activity and Direct Electrochemistry of Immobilized Glucose Oxidase in the Presence of Sodium Dodecyl Benzene Sulfonate and Multiwalled Carbon NanotubesBIOTECHNOLOGY PROGRESS, Issue 1 2008Yuhua Su The electrochemical quartz crystal microbalance (EQCM) technique was utilized to monitor in situ the adsorption of glucose oxidase (GOD) and the mixture of GOD and sodium dodecyl benzene sulfonate (SDBS) onto Au electrodes with and without modification of multiwalled carbon nanotubes (MWCNTs) or SDBS/MWCNTs composite, and the relationship between enzymatic specific activity (ESA) and direct electrochemistry of the immobilized GOD was quantitatively evaluated for the first time. Compared with the bare gold electrode at which a little GOD was adsorbed and the direct electrochemistry of the adsorbed GOD was negligible, the amount and electroactivity of adsorbed GOD were greatly enhanced when the GOD was mixed with SDBS and then adsorbed onto the SDBS/MWCNTs modified Au electrode. However, the ESA of the adsorbed GOD was fiercely decreased to only 16.1% of the value obtained on the bare gold electrode, and the portion of adsorbed GOD showing electrochemical activity exhibited very low enzymatic activity, demonstrating that the electroactivity and ESA of immobilized GOD responded oppositely to the presence of MWCNTs and SDBS. The ESA results obtained from the EQCM method were well supported by conventional UV-vis spectrophotometry. The direct electrochemistry of redox proteins including enzymes as a function of their biological activities is an important concern in biotechnology, and this work may have presented a new and useful protocol to quantitatively evaluate both the electroactivity and ESA of trace immobilized enzymes, which is expected to find wider applications in biocatalysis and biosensing fields. [source] Promoting evidence-based practice: the roles and activities of professional nurses' associationsJOURNAL OF ADVANCED NURSING, Issue 5 2006Theo Van Achterberg PhD RN Aim., This paper reports a study exploring the role perceptions and current activities in evidence-based practice promotion of professional nurses' associations in the Netherlands. Background., The promotion of evidence-based practice contributes to professional standards in nursing and good quality care for patients. As professional nurses' associations can be key players in this process, the nature of their roles and current activities deserves to be explored. Methods., Roles and activities were explored for 43 professional nurses' associations (83% of all national associations). Data were collected using interviews with the associations' board members. Findings from the interviews were validated with those from an analysis of the associations' policy reports and other publications in the previous 2 years. Results., Board members primarily thought that they had roles in the selection and distribution of evidence. The roles of participant (n = 13) and performer (n = 13) in selecting evidence, and those of facilitator (n = 12), initiator (n = 15) and performer (n = 41) in the distribution of evidence were often addressed. A few respondents reflected on roles in generating evidence and implementing evidence-based practice in patient care. A majority of the associations was contemplating activities in the promotion of evidence-based practice. Specific activities for each of six relevant aspects in the promotion of evidence-based practice were found in fewer than five associations. Conclusion., Professional nurses' association roles in the promotion of evidence-based practice need to be viewed in relation to the tasks to be accomplished, especially those of selecting and distributing evidence. Although many organizations expressed motivation, professional nurses' associations have a long way to go in the promotion of evidence-based practice among their members. [source] Systematic planning for Triad projectsREMEDIATION, Issue 1 2004Robert Howe This article examines specific systematic planning steps that can be used for designing and controlling Triad projects. Triad work strategies act to limit decision uncertainty, expedite schedules to meet project milestones, and reduce costs associated with cleanup activities. As a result, the Triad approach is rapidly increasing in popularity. Good project planning has always been seen as the cornerstone of successful Triad projects. However, the specific steps in the systematic planning process have not been extensively published. Demands of Triad projects, which attempt to make maximum use of innovative technologies and sequencing of activities in a learn- as-you-go framework, put new demands on regulators and project managers alike. Specific activities and relationships are identified to assist project managers with dynamic work strategies and real-time measurements to support improved decision making. These include: assembly of stakeholders, a core technical team, and key decisions; development and refinement of a site model; use of demonstrations of methods applicability; development of dynamic work strategies and project sequencing; real-time data management assessment and presentation; and unitized procurement of technologies and services. © 2004 Wiley Periodicals, Inc. [source] Dietary protein requirement of white sea bream (Diplodus sargus) juvenilesAQUACULTURE NUTRITION, Issue 4 2008R. SÁ Abstract A trial was undertaken to estimate the protein requirement of white sea bream (Diplodus sargus). Five fish meal-based diets were formulated to contain graded levels of protein (from 60 to 490 g kg,1). Each diet was assigned to triplicate groups of 25 fish with a mean individual body weight of 22 g. Fish fed the 60 g kg,1 protein diet lost weight during the trial, while growth improved in the other groups as dietary protein level increased up to 270,370 g kg,1. Feed efficiency improved as dietary protein level increased. Maximum protein efficiency ratio (PER) was observed with the 17% protein diet. N retention (NR) (% N intake) was not different among groups fed diets with 17% protein and above. Ammonia excretion (g kg,1ABW day,1) increased as dietary protein level increased, while no differences in urea excretion were noted. An exponential model was used to adjust specific growth rate and NR (g kg,1 day,1) to dietary protein level. Based on that model, dietary protein required for maximum retention was 330 g kg,1, while for maximum growth it was 270 g kg,1. On a wet weight basis, there were no differences in whole body composition of fish-fed diets with 170 g kg,1 protein and above, except for the protein content, which was lower in group fed the 170 g kg,1 protein diet than the 490 g kg,1 protein diet. Specific activities of hepatic amino acid catabolism enzymes (glutamate dehydrogenase, alanine aminotransferase and aspartate aminotransferase) increased as dietary protein levels increased. There were no differences among groups in fatty acid synthetase and malyc enzyme but 6-phosphate dehydrogenase (G6PDH) was significantly lower in fish fed the 60 g kg,1 protein diet than the 170 and 490 g kg,1 protein diets. [source] Selective Long-Term Electrical Stimulation of Fast Glycolytic Fibres Increases Capillary Supply but not Oxidative Enzyme Activity in Rat Skeletal MusclesEXPERIMENTAL PHYSIOLOGY, Issue 5 2000S. Egginton Glycolytic fibres in rat extensor digitorum longus (EDL) and tibialis anterior (TA) were selectively activated, as demonstrated by glycogen depletion, by indirect electrical stimulation via electrodes implanted in the vicinity of the peroneal nerve using high frequency (40 Hz) trains (250 ms at 1 Hz) and low voltage (threshold of palpable contractions). This regime was applied 10 times per day, each bout being of 15 min duration with 60 min recovery, for 2 weeks. Cryostat sections of muscles were stained for alkaline phosphatase to depict capillaries, succinate dehydrogenase (SDH) to demonstrate oxidative fibres, and periodic acid-Schiff reagent (PAS) to verify glycogen depletion. Specific activity of hexokinase (HK), 6-phosphofructokinase, pyruvate kinase, glycogen phosphorylase and cytochrome c oxidase (COX) were estimated separately in homogenates of the EDL and the predominantly glycolytic cortex and oxidative core of the TA. Stimulation increased the activity of HK but not that of oxidative enzymes in fast muscles. Comparison of changes in oxidative capacity and capillary supply showed a dissociation in the predominantly glycolytic TA cortex. Here, COX was 3.9 ± 0.68 ,M min-1 (g wet wt)-1 in stimulated muscles compared with 3.7 ± 0.52 ,M min-1 (g wet wt)-1 in contralateral muscles (difference not significant), while the percentage of oxidative fibres (those positively stained for SDH) was also similar in stimulated (14.0 ± 2.8%) and contralateral (12.2 ± 1.9%) muscles. In contrast, the capillary to fibre ratio was significantly increased (2.01 ± 0.12 vs. 1.55 ± 0.04, P < 0.01). We conclude that capillary supply can be increased independently of oxidative capacity, possibly due to haemodynamic factors, and serves metabolite removal to a greater extent than substrate delivery. [source] Analysis of Karst Tufa from Guangxi, ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2003-BILINSKI, Stanislav FRAN Abstract The paper presents an analysis of characteristic karst tufa from Guangxi, China, which has not been studied before. A comparison with tufa from Dinaric Karst of Croatia is discussed in view of the C-type climate. The major mineral is calcite. Minor minerals are quartz and dolomite, depending on location. The content of calcium carbonate varies from 65% to 92%, and that of magnesium carbonate from 0.03% to 1.77%. Among other elements, the most abundant are Fe, from 0.02% to 1.50%, and Ti, from 0.15% to 0.27%. Many other trace elements (V, Cr, Mn, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Hg and Pb) are also present. Specific activity of radionuclides 4 40K, 232Th, 137Cs, 226Ra and 238U varies from sample to sample. Concentration of U in tufa is close to that reported for sedimentary carbonate. Low concentration of 137Cs indicates that this part of the world was not exposed to nuclear explosions. The concentration of 226Ra is the highest in Mashan County. The ratio 238U/226Ra (0.21,0.71) in tufa from Mashan County is significantly lower than the theoretical value of 1. In 5 of the 11 studied samples, stable isotopes ,13C and ,18O were analyzed. They were dated by means of the 14C method. One tufa sample originated in the Pleistocene and the others in the Holocene. Because all of the tufa samples contain traces of Na and K, and K < Na, the tufa from Guangxi belong to the CO2 -outgassing "N" type according to the classification of Liu and He (1994). [source] Ischaemic preconditioning is related to decreasing levels of extracellular adenosine that may be metabolically useful in the at-risk myocardium: an experimental study in the pigACTA PHYSIOLOGICA, Issue 1 2010A. Waldenström Abstract Aim:, ,Pre-treatment' with short repetitive periods of ischaemia (ischaemic preconditioning) has proved to be a powerful mechanism for modification of the extent of myocardial damage following acute coronary artery occlusion. The exact mechanism of protection induced by ischaemic preconditioning is not known. We herewith put forward a contributing component for protection with preconditioning involving a shift in the adenylate kinase (AK) equilibrium reaction in favour of adenosine triphosphate (ATP) formation. Methods:, A coronary artery was occluded in anaesthetized thoracotomized pigs to induce ischaemic preconditioning as well as a longer period of ischaemia. Microdialysis probes were inserted in ischaemic and control myocardium and were infused with 14C- adenosine with two different specific activities. 14C-lactate was identified and measured in the effluent. Results:,14C-adenosine was taken up by non-preconditioned and preconditioned myocardium during ischaemia. Significantly increased levels of 14C-lactate were recovered in preconditioned myocardium. 14C-adenosine with high specific activity resulted in a specific activity of lactate that was 2.7 times higher than that of lactate after administration of 14C-adenosine with low specific activity. Mass spectrography verified the identity of 14C-lactate. Conclusions:, Preconditioning up-regulates a new metabolic pathway (starting with 5,-nucleotidase and ending up with lactate) resulting in ATP formation in the micromolar range on top of another effect terminating in a useful shift in the AK equilibrium reaction in favour of ATP generation in the millimolar range. Although the up-regulation of the purine nucleoside phosphorylase pathway is clearly demonstrated, its biological relevance remains to be proved. [source] Changes in the activities of protein phosphatase type 1 and type 2A in sea urchin embryos during early developmentDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 4 2000Manabu Kawamoto In the eggs and embryos of sea urchins, the activity of protein phosphatase type 2A (PP2A) increased during the developmental period between fertilization and the morula stage, decreased after the prehatching blastula stage and increased again after hatching. The PP2A activity changed keeping pace with alteration to the activities of cAMP-dependent protein kinase (A kinase), Ca2+/calmodulin-dependent protein kinase (CaM kinase) and casein kinase. Probably, PP2A contributes to the quick turning off of cellular signals because of protein phosphorylation. The activity of protein phosphatase type 1 (PP1) was not detectable up to the morula stage and appreciably increased thereafter. In the isolated nucleus fraction, specific activities of PP1 and PP2A were higher than in whole embryos at all stages in early development. Exponential increase in the number of nuclei because of egg cleavage probably makes PP1 activity detectable in whole embryos after the morula stage. In isolated nuclei, the activities of PP1 and PP2A appreciably decreased after hatching, whereas the activities of A kinase, Ca2+/phospholipid-dependent protein kinase (C kinase) and CaM kinase, as well as casein kinase, became higher. In nuclei, cellular signals caused by protein phosphorylation after hatching do not seem to be turned off by these protein kinases so quickly as before hatching. The PP1 and PP2A in nuclei also seem to contribute to the elimination of signal noise. [source] The Diabetes UK Mozambique Twinning Programme.DIABETIC MEDICINE, Issue 8 2010Results of improvements in diabetes care in Mozambique: a reassessment 6 years later using the Rapid Assessment Protocol for Insulin Access Diabet. Med. 27, 855,861 (2010) Abstract Objective, To assess improvements in diabetes care in Mozambique between 2003 and 2009 following the implementation of the Diabetes UK Twinning Programme. Methods, As in 2003, a Rapid Assessment Protocol was implemented from August to September 2009 in order to assess the improvements in diabetes care and impact of the Diabetes UK Twinning Programme. One hundred and eighty-four interviews were carried out at different levels of the health system in different areas of Mozambique. Results, The Diabetes UK Twinning Programme in Mozambique allowed the development of the first comprehensive non-communicable disease plan in sub-Saharan Africa. The other main improvements include a strengthening of the diabetes association with an 8-fold increase in membership, 265 health workers trained in diabetes care in all provinces, the development of patient education materials inspired by some Diabetes UK tools and the expansion of public awareness, particularly from events associated with World Diabetes Day. Conclusions, Much progress has been made in Mozambique with regard to diabetes and non-communicable diseases. Besides the direct impact of specific activities supported by Diabetes UK, this project allowed for ,collateral' benefits in the overall provision of diabetes care. As diabetes and non-communicable diseases have a low profile on the global health agenda, twinning partnerships based on rigorous needs assessment have the capacity to make significant improvements in diabetes care at a relatively low level of investment. Moreover, this study suggests that the tool used might be of value in assessing progress in health system strengthening as well as in conducting the initial needs assessment. [source] The effect of aging biosolids on the availability of cadmium and zinc in soilEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2001S. Stacey Summary A major concern with the safe re-use of biosolids on land is the potential for release of metals from organic matter in the biosolids, due to decomposition proceeding as biosolids age. To quantify the effects of biosolid aging on Cd and Zn bioavailability, two sewage sludges (Lagoon sludge and Filtered sludge) and a garden compost were incubated at 25°C and 35°C for 100 days. Changes in availability of Cd and Zn were determined using isotope dilution principles, with the materials being labelled with carrier-free 109Cd and 65Zn. We determined isotopically exchangeable metal pools (E values) and plant available metal pools (L values) by measuring specific activities of Cd and Zn in soil extracts and in wheat plants, respectively. Changes in carbon content over time were determined using 13C-NMR spectroscopy and chemical extraction methods, and related to changes in availability of metal pools as determined by isotopic procedures. Hot-water-extractable carbon content, assumed to represent easily decomposable organic matter, decreased during the 100 days by 80,190 mg kg,1. The Compost and Lagoon sludge showed no change in L values for Cd or Zn with time, but in the Filtered sludge the L values for Cd and Zn increased significantly, by 43% and 56%, respectively. The isotopically exchangeable pools of Cd and Zn did not change with incubation treatment of the biosolids. These data indicate that the potential for metal release from biosolids as organic matter decomposes depends to a large extent on the biosolid composition. [source] Differential effects of arachidonoyl trifluoromethyl ketone on arachidonic acid release and lipid mediator biosynthesis by human neutrophilsFEBS JOURNAL, Issue 15 2002Evidence for different arachidonate pools The goal of this study was to determine the effects of a putative specific cytosolic phospholipase A2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3), on arachidonic acid (AA) release and lipid mediator biosynthesis by ionophore-stimulated human neutrophils. Initial studies indicated that AACOCF3 at concentrations 0,10 µm did not affect AA release from neutrophils. In contrast, AACOCF3 potently inhibited leukotriene B4 formation by ionophore-stimulated neutrophils (IC50 , 2.5 µm). Likewise, AACOCF3 significantly inhibited the biosynthesis of platelet activating factor. In cell-free assay systems, 10 µm AACOCF3 inhibited 5-lipoxygenase and CoA-independent transacylase activities. [3H]AA labeling studies indicated thatthe specific activities of cell-associated AA mimicked that of leukotriene B4 and PtdCho/PtdIns, while the specific activities of AA released into the supernatant fluid closely mimicked that of PtdEtn. Taken together, these data argue for the existence of segregated pools of arachidonate in human neutrophils. One pool of AA is linked to lipid mediator biosynthesis while another pool provides free AA that is released from cells. Additionally, the data suggest that AACOCF3 is also an inhibitor of CoA-independent transacylase and 5-lipoxygenase. Thus, caution should be exercised in using AACOCF3 as an inhibitor of cytosolic phospholipase A2 in whole cell assays because of the complexity of AA metabolism. [source] A novel extracellular esterase from Bacillus subtilis and its conversion to a monoacylglycerol hydrolaseFEBS JOURNAL, Issue 21 2000Thorsten Eggert A novel gene lipB, which encodes an extracellular lipolytic enzyme, was identified in the Bacillus subtilis genomic DNA sequence. We have cloned and overexpressed lipB in B. subtilis and Escherichia coli and have also purified the enzyme from a B. subtilis culture supernatant to electrophoretic homogeneity. Four different lipase assays were used to determine its catalytic activity: pH-stat, spectrophotometry, fluorimetry and the monomolecular film technique. LipB preferentially hydrolysed triacylglycerol-esters and p -nitrophenyl-esters of fatty acids with short chain lengths of ,,10 carbon atoms. Triolein, which is a typical substrate for true lipases, was not hydrolysed at all. These results led us to classify LipB as an esterase rather than a lipase. The catalytic triad of LipB consists of residues Ser78, Asp134, and His157 as demonstrated by amino-acid sequence alignments and site-directed mutagenesis. The nucleophile Ser78 is located in a lipase-specific consensus sequence, which is Ala-X-Ser-X-Gly for most Bacillus lipases. All other bacterial lipases contain a glycine residue instead of the alanine at position-2 with respect to the catalytic serine. We have investigated the role of this alanine residue by constructing LipB variant A76G, thereby restoring the lipase-specific consensus motif. When compared with LipB this variant showed a markedly reduced thermostability but an increased stability at pH 5,7. Determination of the specific activities of wild-type LipB and variant A76G using a monomolecular film of the substrate monoolein revealed an interesting result: the A76G substitution had converted the esterase LipB into a monoacylglycerol hydrolase. [source] Expression and regulation of alkaline phosphatases in human breast cancer MCF-7 cellsFEBS JOURNAL, Issue 5 2000Lai-Chen Tsai The effect of retinoic acid and dexamethasone on alkaline phosphatase (AP) expression was investigated in human breast cancer MCF-7 cells. Cellular AP activity was induced significantly by retinoic acid or dexamethasone in a time-dependent and dose-dependent fashion. A marked synergistic induction of AP activity was observed when the cells were incubated with both agents simultaneously. Two AP isozymes, tissue-nonspecific (TNAP) and intestinal (IAP), were shown to be expressed in MCF-7 cells as confirmed by the differential rate of thermal inactivation of these isozymes and RT-PCR. Based on the two-isozyme thermal-inactivation model, the specific activities for TNAP and IAP in each sample were analyzed. TNAP activity was induced only by retinoic acid and IAP activity was induced only by dexamethasone. Whereas dexamethasone conferred no significant effect on TNAP activity, retinoic acid was shown to inhibit IAP activity by , 50%. Interestingly, TNAP was found to be the only isozyme activity superinduced when the cells were costimulated with retinoic acid and dexamethasone. Northern blot and RT-PCR analysis were then used to demonstrate that the steady-state TNAP mRNA level was also superinduced, which indicates that the superinduction is regulated at the transcriptional or post-transcriptional levels. In the presence of the glucocorticoid receptor antagonist RU486, the dexamethasone-mediated induction of IAP activity was blocked completely as expected. However, the ability of RU486 to antagonize the action of glucocorticoid was greatly compromised in dexamethasone-mediated superinduction of TNAP activity. Furthermore, in the presence of retinoic acid, RU486 behaved as an agonist, and conferred superinduction of TNAP gene expression in the same way as dexamethasone. Taken together, these observations suggest that the induction of IAP activity by dexamethasone and the superinduction of TNAP by dexamethasone were mediated through distinct regulatory pathways. In addition, retinoic acid plays an essential role in the superinduction of TNAP gene expression by enabling dexamethasone to exert its agonist activity, which otherwise has no effect. [source] Bacterial quorum sensing and nitrogen cycling in rhizosphere soilFEMS MICROBIOLOGY ECOLOGY, Issue 2 2008Kristen M. DeAngelis Abstract Plant photosynthate fuels carbon-limited microbial growth and activity, resulting in increased rhizosphere nitrogen (N) mineralization. Most soil organic nitrogen is macromolecular (chitin, protein, nucleotides); enzymatic depolymerization is likely rate limiting for plant nitrogen accumulation. Analyzing Avena (wild oat) planted in microcosms containing sieved field soil, we observed increased rhizosphere chitinase and protease-specific activities, bacterial cell densities, and dissolved organic nitrogen (DON) compared with bulk soil. Low-molecular-weight (MW) DON (<3000 Da) was undetectable in bulk soil but comprised 15% of rhizosphere DON. Extracellular enzyme production in many bacteria requires quorum sensing (QS), cell-density-dependent group behavior. Because proteobacteria are considered major rhizosphere colonizers, we assayed the proteobacterial QS signals N -acyl-homoserine lactones (AHLs), which were significantly increased in the rhizosphere. To investigate the linkage between soil signaling and nitrogen cycling, we characterized 533 bacterial isolates from Avena rhizosphere: 24% had chitinase or protease activity and AHL production; disruption of QS in seven of eight isolates disrupted enzyme activity. Many Alphaproteobacteria were newly found with QS-controlled extracellular enzyme activity. Enhanced specific activities of nitrogen-cycling enzymes accompanied by bacterial density-dependent behaviors in rhizosphere soil gives rise to the hypothesis that QS could be a control point in the complex process of rhizosphere nitrogen mineralization. [source] High-dose methylprednisolone influences the physiology and virulence of Candida albicans ambiguously and enhances the candidacidal activity of the polyene antibiotic amphotericin B and the superoxide-generating agent menadioneFEMS YEAST RESEARCH, Issue 2 2007Ágnes Gyetvai Abstract Although exposure of Candida albicans cells to high-dose (4 mM) methylprednisolone stimulated microbial growth, germination rate in serum and phospholipase release, it also promoted the recognition of C. albicans cells by polymorphonuclear leukocytes. Pretreatment of C. albicans cells with methylprednisolone did not result in any increase in the pathogenicity of the fungus in intraperitoneal and intravenous mouse assays. Therefore, the virulence of C. albicans is unlikely to increase in patients treated with comparably high-dose methylprednisolone on skin and mucosal membranes. Methylprednisolone treatments also increased the production of conjugated dienes and thiobarbituric acid-reactive substances, and the menadione sensitivity of C. albicans cells, which can be explained by a significant decrease in the specific activities of several antioxidant enzymes. The combination of methylprednisolone with oxidants, e.g. in topical applications, may be of clinical importance when the predisposition to candidiasis is high. Methylprednisolone treatments negatively affected membrane fluidity and decreased the antifungal effects of both the polyene antibiotic nystatin and the ergosterol biosynthesis inhibitor lovastatin, and also enhanced the deleterious effects of the polyene antimycotic amphotericin B on C. albicans cells. These corticosteroid,polyene drug interactions should be considered in the treatment of C. albicans infections in patients with prolonged topical application of corticosteroids. [source] Valuing health: a new proposalHEALTH ECONOMICS, Issue 3 2010Daniel M. Hausman Abstract After criticizing existing systems of health measurement for their unargued commitment to evaluating health states in terms of preferences or well-being, this essay argues that public rather than private values of health states should help guide the allocation of health-related resources. Private evaluation of health states is relative to a prior individual choice of specific activities and goals, while public evaluation is relative to the whole range of important activities and goals. Public evaluation is concerned with securing a wide range of choices as well as with success given one's choice. A reasonable simplification from the public perspective is to focus on just two features of health states: the subjective feelings attached to health states and the limitations that health states imply on the range of important activities that individuals can pursue. Focusing on just these two dimensions permits the construction of a parsimonious classification of health states with regard to what matters most from the public perspective. This classification, which resembles those in the HALex and the Rosser and Kind Disability and Distress Index, might best be built on top of existing health-state classifications, by mapping the health states they define to activity-limitation/feeling pairs. To assign values to these pairs, I propose relying on deliberative groups to make comparisons among the pairs with respect to the relation ,is a more serious limitation on the range of objectives and good lives available to members of the population'. A ranking according to this property, is not a preference ranking, because it is not a ranking in terms of everything that matters to individuals. Working back from the weights attached to the activity-limitation/feeling pairs, one can impute weights for the health states in other classification systems that were mapped to those pairs. If those weights coincide roughly with current weights, then one legitimizes current weights and provides a vehicle for their public discussion and possible revision. If those weights do not coincide, then one has both an argument for revising current views of the cost effectiveness of treatments and policies and a method to carry out such a revision. Copyright © 2009 John Wiley & Sons, Ltd. [source] Occurrence of oxidative impairments, response of antioxidant defences and associated biochemical perturbations in male reproductive milieu in the Streptozotocin-diabetic ratINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 6 2007B. Shrilatha Summary Oxidative stress is implicated to play a vital role in the pathogenesis of various diabetic complications. While reproductive dysfunction is a well recognized consequence of diabetes mellitus, the underlying mechanisms are poorly understood. The present study aims to obtain insights into the incidence, extent and progression of oxidative impairments in testis and epididymal sperm (ES) in streptozotocin (STZ)-induced diabetic rat during early and progressive phase. Adult rats (CFT-Wistar strain) rendered diabetic by an acute dose of STZ (60 mg/kg bw, i.p.) were examined for induction of hyperglycaemia at 72 h, followed by the assessment of oxidative impairments in testis and ES over a 6-week period. Oxidative damage was ascertained by measuring the malondialdehyde levels, reactive oxygen species (ROS) generation, alterations in antioxidant defences and extent of protein oxidation. STZ induced a significant (2.5-fold) increase in blood glucose levels. In diabetic rats, both testis and ES showed enhanced status of lipid peroxidation measured as increased TBARS and ROS from week 2 onwards. These impairments in testis were consistent, progressive and accompanied by marked alterations in antioxidant defences and elevated protein carbonyls. Varying degree of reduction in the specific activities of antioxidant enzymes was evident in testis and ES, while the activity of glutathione- S -transferase (GST) was significantly elevated. Reduced glutathione (GSH) and vitamin E levels were consistently reduced in testis. Lipid dysmetabolism measured in terms of increased cholesterol, triglycerides and phospholipids was evident only beyond week 2 in diabetic testis. Taken together, these results indicate that the testis and ES are indeed subjected to significant oxidative stress in the STZ-diabetic rat both during early as well as progressive phase. It is hypothesized that oxidative impairments in testis which develop over time may at least in part contribute towards the development of testicular dysfunction eventually leading to testicular degeneration which culminates in reduced fertility during the progressive phase of STZ-induced diabetes in adult rats. [source] Limb bones asymmetry and stress in medieval and recent populations of Central EuropeINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2008M. Kujanová Abstract Monitoring the degree of asymmetry in different parts of the human body can contribute to population studies, as it may be connected indirectly with the social structure, living conditions, and also with biomechanical stress affecting the person. Analysis of asymmetry may also assess preferential use of the right or left of the body during specific activities. This study is based on the measurements of bones of the upper and lower limbs of skeletons derived from the remarkable medieval cemeteries of Mikul,ice-Kostelisko (78 male, 132 female) and Pru,ánky (66 male, 69 female) (9th,12th centuries AD), and a series of skeletons representing a recent population from Bohemia (143 male, 157 female). The objective was to assess directional asymmetry (DA), fluctuating asymmetry (FA) and antisymmetry (AS) of the dimensions of the evaluated bones, and to use these data to compare the characteristics of the medieval and recent populations. DA was recorded in most dimensions. In the upper limb, the humerus exhibited the greatest expression of asymmetry, and, with the exception of the clavicle, DA was always more pronounced on the right side. Conversely, DA was less prevalent in the lower limb bones. It was more pronounced on the transverse, sagittal and circumferential dimensions of the diaphyses and epiphyses than on the length, and in most cases it was on the left side. The FA values were very low, and almost negligible in relation to the size. Nevertheless, FA was markedly more frequent on the lower than on the upper limb. In contrast to the medieval population, the recent population had higher FA and DA values. Thus, we propose that people from this medieval population were subjected to lower developmental stress than the recent sample. Copyright © 2008 John Wiley & Sons, Ltd. [source] Short-term effect of acarbose on specific intestinal disaccharidase activities and hyperglycaemia in CBA diabetic miceJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 7-8 2003D. Jureti Summary The purpose of this study was to examine the short-term effects of 75, 100 and 150 mg of acarbose mixed in 100 g standard laboratory chow on specific intestinal disaccharidase activities and on hyperglycaemia in diabetic CBA strain mice on standard diet. The small intestine was excised and divided into three segments, from pylorus to duodenum, and two equal lengths of the jejunum and ileum of control and diabetic mice with or without added acarbose. Specific maltase and sucrase activities were determined using maltose and sucrose as substrates respectively. Increased specific activities of maltase and sucrase were detected in the intestines of CBA mice on standard laboratory diet seven days after alloxan-induced diabetes. Feeding for 7 days with 75, 100 or 150 mg acarbose uniformly mixed in 100 g standard laboratory chow, induced a decrease in the specific maltase and sucrase activities, compared with diabetic mice on standard laboratory diet. Feeding with 75 mg acarbose mixed in 100 g standard laboratory chow caused a statistically significant decrease of maltase in the duodenum and of sucrase in duodenum and jejunum, without a antihyperglycaemic effect. Feeding with 100 or 150 mg caused statistically significant decreases in specific maltase and sucrase activities in duodenum, jejunum and ileum. An antihyperglycaemic effect was observed only in the group of diabetic mice fed with 100 mg acarbose. This indicates that the antihyperglycaemic effect of acarbose involves factors other than these, related only to its inhibitory effect on disaccharidase activities. [source] Evidences of high carbon catabolic enzyme activities during sporulation of Pleurotus ostreatus (Florida)JOURNAL OF BASIC MICROBIOLOGY, Issue 6 2003Tapas K. Chakraborty Measurements of the specific activities of the representative enzymes of different pathways linked to carbohydrate metabolism indicate that glycolysis and TCA cycles are the major route of carbohydrate catabolism in the sporulating phase of fruiting body development in Pleurotus ostreatus. Enzymes of the pentose phosphate pathway always showed lower specific activities as compared to those of the enzymes of the glycolytic pathway. The activity of NADP linked glutamate dehydrogenase which is known to be an anabolic enzyme decreased drastically in sporulating fruiting bodies and in spore containing gill tissue (spore bearing structure). Mannitol dehydrogenase activity declined significantly in the sporulating phase of P. ostreatus. The high rate of metabolism during sporulation was further supported by a lower rate of gluconeogenesis at this stage. Concentrations of all the major sugars of the fruiting body (mannitol, glucose and trehalose) decreased in the mature fruiting body and gill tissue. This indicated high catabolic activities at this stage of development. [source] Spatial and Temporal Ontogenies of Glutathione Peroxidase and Glutathione Disulfide Reductase During Development of the Prenatal RatJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2001Hyungsuk Choe Abstract Spatial and temporal expression and regulation of the antioxidant enzymes, glutathione peroxidase (GSH-Px), glutathione disulfide reductase (GSSG-Rd) may be important in determining cell-specific susceptibility to embryotoxicants. Creation of tissue-specific ontogenies for antioxidant enzyme activities during development is an important first step in understanding regulatory relationships. Early organogenesis-stage embryos were grouped according to the somite number (GD 9,13), and fetuses were evaluated by gestational day (GD 14,21). GSH-Px activities in the visceral yolk sac (VYS) increased on consecutive days from GD 9 to GD 13, representing a 5.7-fold increase during this period of development. GSH-Px activities in VYS decreased after GD 13, ultimately constituting a 37% decrease at GD 21. Head, heart, and trunk specific activities generally increased from GD 9 to GD 13 albeit not to the same magnitude as detected in the VYS. GSSG-Rd activities showed substantial increases in the VYS from GD 9 to GD 13, 6.3-fold and decreased thereafter to 50% by GD 21. The greatest changes in enzyme activities were noted in the period between GD 10 and GD 11, where the embryo establishes an active cardiovascular system and begins to convert to aerobic metabolism. Generally, from GD 14,21, embryonic organ GSH-Px and GSSG-Rd activities either remained constant or increased as gestation progressed. These studies suggest the importance of the VYS in dealing with ROS and protecting the embryo. Furthermore, understanding the consequences of lower antioxidant activities during organogenesis may help to pinpoint periods of teratogenic susceptibility to xenobiotics and increased oxygen. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:197,206, 2001 [source] Specificities of proteases for use in leather manufactureJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2006Farhad Foroughi Abstract Proteases are used in leather manufacture in the processes of soaking, unhairing and bating of hides and skins. However proteases can be relatively non-specific in their usage, and for improved efficacy of enzyme biocatalysis within the industry, an analysis of specific activities of enzymes towards skin proteins was undertaken. Most commercial proteases for soaking showed substantial activity against the substrates elastin,Congo Red and Azocoll but little or no activity against keratin,azure and hide powder black. Enzymes used for unhairing in conjunction with 30% of the usual concentration of sulfide to effect chemical unhairing showed moderate activity against all substrates tested (selected as representative of skin proteins), while proteases used in bating showed activity against Azocoll and elastin,Congo Red but had no keratinase activity and little activity against hide powder black. Bating proteases and soaking proteases displayed similar activities at pH 8. Microbes isolated in the screening of organisms from putrefied skins included one fungal and two bacterial isolates whose extracellular enzymes had efficient unhairing activity without the addition of sulfide. Enzyme activities for these proteases included high activity measured against Azocoll with little or no activity against elastin,Congo Red, keratin,azure and hide powder black. Neither elastase nor keratinase activities were determined as being essential for unhairing. Copyright © 2005 Society of Chemical Industry [source] Juice Clarification by Thermostable Fractions of Marsh Grapefruit PectinmethylesteraseJOURNAL OF FOOD SCIENCE, Issue 5 2002M. Corredig ABSTRACT: Orange juice clarification by thermostable pectinmethylesterase (TS-PME), isolated from grapefruit pulp by ammonium sulfate precipitation, and ion-exchange and affinity chromatography was investigated. TSPME, having different specific activities, induced different clarification behavior of reconstituted orange juice at 2 units/ml. Based on percent transmittance, TS-PME fraction with the lower specific activity clarified juices earlier than TS-PME at higher specific activity. Particle size distribution of the cloud-soluble fraction showed that TS-PME increased the average particle size from 0.7 ,m to 1 mm and maintained a monomodal distribution. After 27 d of storage at 4 °C, samples of clarified juice still showed a large population of small cloud particles when measured by diffraction light scattering. [source] Synthesis of 2-[(2-chloro-2,-[18F]fluoroethyl)amino]-2H-1,3,2-oxazaphosphorinane-2-oxide (18F-fluorocyclophosphamide), a potential tracer for breast tumor prognostic imaging with PETJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2005Goran Lacan Abstract A fluorine-18 labeled analog of the widely used chemotherapeutic agent cyclophosphamide was synthesized as a tracer for prognostic imaging with positron emission tomography. 2-[(2-Chloro-2,-[18F]fluoroethyl)amino]-2H-1,3,2-oxazaphosphorinane-2-oxide (18F-fluorocyclophosphamide), was prepared by direct halogen exchange reaction from the parent cyclophosphamide. In small-scale syntheses, radiochemical yields of up to 4.9% and specific activities of 960 Ci/mmol were achieved in a total synthesis time of 60,75 min. The [18F]-labeled cyclophosphamide analog with radioactive purity >99% and chemical purity >96% was suitable for in vivo (microPET imaging) and ex vivo studies of a murine model of human breast tumors. Copyright © 2005 John Wiley & Sons, Ltd. [source] Fast and efficient tritium labelling of the nonsteroidal anti-inflammatory drugs naproxen, tolmetin, and zomepiracJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2005Steen K. Johansen Abstract Fast and efficient tritium labelling of the nonsteroidal anti-inflammatory drugs naproxen, tolmetin and zomepirac is reported. Naproxen along with its (R)-enantiomer were labelled by catalytic tritium,halogen exchange of the corresponding 5-bromo derivatives providing [3H]naproxen with a specific activity of 25.4 Ci/mmol. Tolmetin and zomepirac were labelled by the hydrogen isotope exchange reaction using Crabtree's catalyst. This provided [3H]tolmetin and [3H]zomepirac with specific activities of 80.8 and 64.3 Ci/mmol, respectively. All compounds were obtained in high radiochemical purity (>98%). Copyright © 2005 John Wiley & Sons, Ltd. [source] Synthesis of 14C-labelled EM-800 (SCH 57050) and EM-652·HCl (SCH 57068·HCl, acolbifene), pure selective estrogen receptor modulatorsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 11 2004Jean-Yves Sancéau Abstract EM-800 (SCH 57050) and EM-652·HCl (SCH 57068·HCl, acolbifene) are orally active pure selective estrogen receptor modulators. The corresponding 14C2 -radiolabelled compounds 1 and 2 were synthesized for metabolic studies with uniform labelling of two carbons within the benzene ring of the 2H-1-benzopyran moiety by optical resolution of racemic (±)-[14C2]EM-343 4. This pivotal intermediate amine was prepared in 6 steps with 38% yield from commercially available [U- 14C2]resorcinol (3). Resolution by selective crystallization of the diastereomeric mixture of (S)-(+)-camphorsulfonates salts gave the desired (+)-[14C2]EM-652·(+)-CSA 13. Moreover, the racemic amine 4 was recovered from mother liquors by basic treatment, and resolved again. We obtained salt 13, at a 52% yield with 97% diastereomeric excess by repeating the resolution,racemization process. Finally, the corresponding dipivaloate (+)-[14C2]EM-800 1 and hydrochloride salt (+)-[14C2]EM-652·HCl 2 were prepared at respective specific activities of 19.7 and 24.5 µCi/mg with 96.3% radiochemical purity. Copyright © 2004 John Wiley & Sons, Ltd. [source] The synthesis of tritium labelled neurokinin-1 receptor ligandsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 2 2004Terence G. Hamill Abstract Radiolabelled neurokinin-1 (NK1) receptor antagonists 1b and 2b were required for in vitro/in vivo characterization to support the development of 1a and 2a as fluorine-18 labelled PET ligands. These tritium labelled compounds were synthesized from aryl iodide precursors giving the final tritiated tracers with specific activities of 28 (1b) and 14 (2b) Ci/mmol. Copyright © 2004 John Wiley & Sons, Ltd. [source] Synthesis of tritium labelled 3(R)-HETE and 3(R),18(R/S)-DiHETE through a common synthetic routeJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 1 2004Natalya V. Groza Abstract An efficient procedure for the synthesis of 3-hydroxyoxylipins labelled with tritium on all double bond positions is reported. The synthetic scheme involves a joint route for the formation of tetraacetylenic precursors followed by stereoselective reduction of the triple bonds either with hydrogen or tritium. The final tritiated products were obtained with specific activities ranging from 1.65 to 1.80 Ci/mmol. Copyright © 2003 John Wiley & Sons, Ltd. [source] Preparation of tritium-labelled BIIL 260 of high specific radioactivityJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 3 2003V.P. Shevchenko Abstract Various approaches to the synthesis of tritium-labelled BIIL 260 with high specific radioactivity were investigated. Attempts to incorporate tritium directly into BIIL 260 were made by solid-phase isotope exchange with tritium gas and by isotope exchange with tritiated water which yielded a final product with specific activities ranging from 2 to 7 Ci/mmol. However, the solid-phase and liquid-phase dehalogenations of an appropriate synthon fragment of BIIL 260 followed by its subsequent conversion to the final product via chemical synthesis yielded the desired tritium-labelled BIIL 260 with specific activities of 25 or 71 Ci/mmol, depending upon the precursors and methods used in the dehalogenation step. Copyright © 2002 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||