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Selected AbstractsA miniaturized assay for influenza neuraminidase-inhibiting antibodies utilizing reverse genetics-derived antigensINFLUENZA AND OTHER RESPIRATORY VIRUSES, Issue 5 2009Matthew R. Sandbulte Background, Antibodies to neuraminidase (NA) contribute to protection during influenza virus infection, but NA inhibition (NI) titers are not routinely analyzed in vaccine trials. One reason is the cumbersome nature of the conventional thiobarbituric acid (TBA) NI assay, which uses chemical methods to quantify free sialic acid following incubation of NA with substrate in the presence of serum. In addition, the assay is complicated by the need to use virus of a hemagglutinin (HA) subtype novel to the host to detect NA-specific antibodies only. Objectives, Our primary objectives were to miniaturize the colorimetric NI assay to a format suitable for quantitative analysis of large numbers of samples, and validate the specificity and sensitivity of the miniaturized format with ferret and human sera. An additional aim was to use reverse genetics to construct HA-mismatched viral reagents bearing NA of recent influenza A vaccine strains and H6 HA. Results, Analysis of ferret antisera by the miniaturized assay demonstrated sensitivity and specificity comparable with the conventional assay. Similar increases in the NI titers in sera from vaccinated human volunteers were measured in miniaturized and conventional assays. Inactivated and live-attenuated vaccines increased NI titers against a given subtype at approximately the same rate. Conclusions, The reagents and miniaturized format of the TBA method described here provide a platform for practical serological monitoring of functional antibodies against NA. [source] Impact of laparoscopic cholecystectomy on hospital utilizationANZ JOURNAL OF SURGERY, Issue 4 2004Michael S. Hobbs Objective: The objective of the present study was to assess the impact of laparoscopic cholecystectomy (LC) and associated endoscopic retrograde pancreatography (ERCP) on hospital utilization. Background: Laparoscopic cholecystectomy (LC) has resulted in marked reductions in average length of hospital stay; but population-based studies of hospital utilization have generally not taken into account increased cholecystectomy rates or associated increases in pre and postoperative admissions. Methods: We conducted a population-based study of all residents of Western Australia who underwent cholecystectomy in the period 1980,2000. Record linkage was used to identify pre and postoperative admissions, and to estimate aggregate length of stay per case based on all relevant admissions. We estimated trends in cholecystectomy rates, proportions of cases with related pre and postoperative hospital admissions, average aggregate length of stay per case and total bed utilization per unit of population. Results: The introduction of LC was associated with a sustained increase in rates of cholecystectomy of 25%. Similar increases occurred in the percentage of cases with related preoperative and postoperative admissions. Average length of stay for index admissions declined by nearly 60% compared with 50% for all related admissions. Per capita hospital utilization for index admissions decreased by 45% compared with 38% for index and associated admissions combined, and 32% for all admissions for biliary disease. Conclusions: Reduced hospital utilization associated with LC was partly offset by increases in pre and postoperative admissions and a sustained increase in cholecystectomy rates. Record linkage is required to assess the true impact of new technologies on hospital utilization. [source] Update on epidemiology of pollinosis in Japan: changes over the last 10 yearsCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2010K. Nakae Summary A nationwide epidemiologic survey of atopic diseases including allergic pollinosis was conducted in 9656 Japanese otorhinolaryngologists and their family members during the Japanese cedar pollen dispersion season in 2008 using methods identical to a previous survey that was performed in 1998. The survey response rate was 37.7% (compared with 42.8% in 1998). The overall prevalence rate of Japanese cedar pollinosis was 26.5%, which is an increase of approximately 9% from that noted in 1998. Similar increases were observed in all age groups, and the prevalence rate was similar between male and female respondents. A unimodal distribution was observed in male and female subjects, with a peak in both men and women aged in their 40s. Nationwide, a consistent positive relation was observed between the prevalence of Japanese cedar pollinosis and the regional Japanese cedar pollen counts. The prevalence rate of pollinosis other than Japanese cedar pollinosis and of perennial allergic rhinitis was 15.4% and 23.3%, respectively; both disease entities tended to occur more frequently in male than in female subjects. The prevalence rate of asthma, atopic dermatitis, and food allergy was 5.2%, 14.1%, and 3.9%, respectively. Our results suggest that the prevalence rates of atopic diseases including Japanese cedar pollinosis are dramatically increasing across all age groups in Japan. In particular, the increasing prevalence rate of Japanese cedar pollinosis seems to reflect higher exposure to the Japanese cedar pollen antigen in many prefectures. [source] Organs/Systems Potentially Involved In One Model Of Programmed Hypertension In SheepCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2001Miodrag Dodic SUMMARY 1. When pregnant ewes and their fetuses are exposed to the synthetic glucocorticoid dexamethasone for 2 days early in pregnancy (days 26,28; term 145,150 days), female offspring have increased blood pressure relative to a control group. In one series, this was shown to be due to increased cardiac output, concomitant with a reset mean arterial pressure/heart rate reflex. The first group of such animals had, by the age of 7 years, left ventricular hypertrophy and reduced cardiac functional capacity. 2. The elevation in blood pressure is not maintained by any change in the peripheral renin,angiotensin system (RAS). 3. There is, however, preliminary evidence that some aspects of local RAS (particularly in the kidney and brain) could have participated in the ,programming' event. The levels of mRNA for angiotensin II receptors (AT1, AT2) and angiotensinogen are increased in the kidney of such dexamethasone-treated fetuses in late gestation (130 days), some 100 days after steroid treatment. Similar increases in AT1 mRNA in the medulla oblongata of the fetal brain and large increases of mRNA for angiotensinogen occur in the hypothalamus. 4. These findings, together with evidence from the literature, suggest that both the kidney and parts of the brain are affected by events that also ,program' high blood pressure in the offspring of animals in which the intra-uterine environment has been perturbed at some stage. [source] Comparative effects of resistance training on peak isometric torque, muscle hypertrophy, voluntary activation and surface EMG between young and elderly womenCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 2 2007Jack Cannon Summary We compared the effect of a 10-week resistance training program on peak isometric torque, muscle hypertrophy, voluntary activation and electromyogram signal amplitude (EMG) of the knee extensors between young and elderly women. Nine young women (YW; range 20,30 years) and eight elderly women (EW; 64,78 years) performed three sets of ten repetitions at 75% 1 repetition maximum for the bilateral leg extension and bilateral leg curl 3 days per week for 10 weeks. Peak isometric torque, EMG and voluntary activation were assessed before, during, and after the training period, while knee extensor lean muscle cross-sectional area (LCSA) and lean muscle volume (LMV) were assessed before and after the training period only. Similar increases in peak isometric torque (16% and 18%), LCSA (13% and 12%), LMV (10% and 9%) and EMG (19% and 21%) were observed between YW and EW, respectively, at the completion of training (P<0·05), while the increase in voluntary activation in YW (1·9%) and EW (2·1%) was not significant (P>0·05). These findings provide evidence to indicate that participation in regular resistance exercise can have significant neuromuscular benefits in women independent of age. The lack of change in voluntary activation following resistance training in both age groups despite the increase in EMG may be related to differences between measurements in their ability to detect resistance training-induced changes in motor unit activity. However, it is possible that neural adaptation did not occur and that the increase in EMG was due to peripheral adaptations. [source] Inflammatory mediators in perinatal asphyxia and infectionACTA PAEDIATRICA, Issue 2002M Xanthou Aim: To determine serum levels of interleukin-6 (IL-6), IL-1,, tumor necrosis factor-, (TNF-,), soluble intercellular adhesion molecule-1 (sICAM-1) and C-reactive protein (CRP) in asphyxiated neonates and compare these inflammatory factors with those found in neonates with perinatal infection. Methods: 88 neonates were studied, of whom 36 were asphyxiated, 18 were infected and the remaining 34 were controls. Peripheral blood samples were obtained on the 1st, 3rd and 5th postnatal days. Results: Cytokines IL-6 and IL-1, as well as sICAM-1 serum levels did not differ between asphyxiated and infected neonates; however, at most time periods, their values were significantly higher than controls. TNF-, was similar in the three groups of neonates. CRP serum values were significantly higher in the infected neonates than in the asphyxiated or control subjects. Among the 54 asphyxiated and infected neonates, 15 were considered as severe cases and 39 as mild. The severe cases, at most time periods, had significantly higher IL-6, IL-1, and sICAM-1 levels compared with the mild ones. Through receiver operating characteristic curves the cut-off points, sensitivities, and specificities for distinguishing neonates at risk or at high risk for brain damage were established. Conclusion: Similar increases in serum levels of IL-6, IL-1, and sICAM-1 were found in perinatally asphyxiated and infected neonates. As these increases correlated with the severity of the perinatal insults, neonates at high risk for brain damage might be detected. [source] Changes in presumed motor cortical activity during fatiguing muscle contraction in humansACTA PHYSIOLOGICA, Issue 3 2010T. Seifert Abstract Aim:, Changes in sensory information from active muscles accompany fatiguing exercise and the force-generating capacity deteriorates. The central motor commands therefore must adjust depending on the task performed. Muscle potentials evoked by transcranial magnetic stimulation (TMS) change during the course of fatiguing muscle activity, which demonstrates activity changes in cortical or spinal networks during fatiguing exercise. Here, we investigate cortical mechanisms that are actively involved in driving the contracting muscles. Methods:, During a sustained submaximal contraction (30% of maximal voluntary contraction) of the elbow flexor muscles we applied TMS over the motor cortex. At an intensity below motor threshold, TMS reduced the ongoing muscle activity in biceps brachii. This reduction appears as a suppression at short latency of the stimulus-triggered average of rectified electromyographic (EMG) activity. The magnitude of the suppression was evaluated relative to the mean EMG activity during the 50 ms prior to the cortical stimulus. Results:, During the first 2 min of the fatiguing muscle contraction the suppression was 10 ± 0.9% of the ongoing EMG activity. At 2 min prior to task failure the suppression had reached 16 ± 2.1%. In control experiments without fatigue we did not find a similar increase in suppression with increasing levels of ongoing EMG activity. Conclusion:, Using a form of TMS which reduces cortical output to motor neurones (and disfacilitates them), this study suggests that neuromuscular fatigue increases this disfacilitatory effect. This finding is consistent with an increase in the excitability of inhibitory circuits controlling corticospinal output. [source] Evaluation of mutant frequencies of chemically induced tumors and normal tissues in ,/cII transgenic miceENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2005Jon C. Mirsalis Abstract Genomic instability has been implicated as an important component in tumor progression. Evaluation of mutant frequencies (MFs) in tumors of transgenic mice containing nontranscribed marker genes should be useful for quantitating mutation rates in tumors as the physiologically inactive transgene provides neither a positive nor a negative selective pressure on the tumor. We have conducted long-term carcinogenicity studies in ,/cII transgenic B6C3F1 mice using a variety of genotoxic and nongenotoxic test agents and have evaluated the mutant frequencies in both tumors and normal tissues from these animals. Mice were administered diethylnitrosamine (DEN) as three intraperitoneal injections of 15 mg/kg; phenobarbital (PB) or oxazepam (OXP) provided ad libitum at 0.1% or 0.25% in the diet, respectively; DEN initiation plus PB in the diet; or urethane (UTH) provided ad libitum at 0.2% in the drinking water. Normal tissues and tumors were isolated at various times over a 2-year period and half of each tissue/tumor was evaluated histopathologically and the other half was evaluated for MF in the cII transgene. Approximately 20 mutants from each of 166 individual tissues (tumor and nontumor) were sequenced to determine whether increases in MF represented unique mutations or were due to clonal expansion. UTH produced significant increases in MF in normal liver and lung. DEN either with or without PB promotion produced significant increases in MF in liver and correction of MF for clonality produced little change in the overall MF in these groups. PB produced a twofold increase in liver MF over controls after 27 weeks of treatment, but a similar increase was not observed with longer dosing times; at later time points, the MF in the PB groups was lower than that of the control group, suggesting that PB is not producing direct DNA damage in the liver. OXP failed to produce an increase in MF over controls, even after 78 weeks of treatment. Selected cases of genomic instability were observed in tumors from all treatments except OXP, with individual liver tumors showing very high MF values even after clonal correction. One rare and interesting finding was noted in a single mouse treated with UTH, where a mammary metastasis had an MF approximately 10-fold greater than the parent tumor, with 75% of the mutations independent, providing strong evidence of genomic instability. There was no clear correlation between tumor phenotype and MF except that pulmonary adenomas generally had higher MFs than normal lung in both genotoxic and nongenotoxic treatment groups. Likewise, there was no correlation between tumor size and MF after correction for clonality. The results presented here demonstrate that individual tumors can show significant genomic instability, with very significant increases in MF that are not attributed to clonal expansion of a single mutant cell. Environ. Mol. Mutagen., 2005. © 2004 Wiley-Liss, Inc. [source] Intra- and interlaboratory calibration of the DR CALUX® bioassay for the analysis of dioxins and dioxin-like chemicals in sedimentsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2004Harrie T. Besselink Abstract In the Fourth National Policy Document on Water Management in the Netherlands [1], it is defined that in 2003, in addition to the assessment of chemical substances, special guidelines for the assessment of dredged material should be recorded. The assessment of dredged material is based on integrated chemical and biological effect measurements. Among others, the DR CALUX® (dioxin responsive,chemically activated luciferase expression) bioassay has tentatively been recommended for inclusion in the dredged material assessment. To ensure the reliability of this bioassay, an intra- and interlaboratory validation study, or ring test, was performed, organized by the Dutch National Institute for Coastal and Marine Management (RIKZ) in cooperation with BioDetection Systems BV (BDS). The intralaboratory repeatability and reproducibility and the limit of detection (LOD) and quantification (LOQ) of the DR CALUX bioassay were determined by analyzing sediment extracts and dimethyl sulfoxide (DMSO) blanks. The highest observed repeatability was found to be 24.1%, whereas the highest observed reproducibility was calculated to be 19.9%. Based on the obtained results, the LOD and LOQ to be applied for the bioassay are 0.3 and 1.0 pM, respectively. The interlaboratory calibration study was divided into three phases, starting with analyzing pure chemicals. During the second phase, sediment extracts were analyzed, whereas in the third phase, whole sediments had to be extracted, cleaned, and analyzed. The average interlaboratory repeatability increased from 14.6% for the analysis of pure compound to 26.1% for the analysis of whole matrix. A similar increase in reproducibility with increasing complexity of handlings was observed with the interlaboratory reproducibility of 6.5% for pure compound and 27.9% for whole matrix. The results of this study are intended as a starting point for implementing the integrated chemical,biological assessment strategy and for systematic monitoring of dredged materials and related materials in the coming years. [source] Effects of nicotine in the dopaminergic system of mice lacking the alpha4 subunit of neuronal nicotinic acetylcholine receptorsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003L. M. Marubio Abstract The mesostriatal dopaminergic system influences locomotor activity and the reinforcing properties of many drugs of abuse including nicotine. Here we investigate the role of the ,4 nicotinic acetylcholine receptor (nAChR) subunit in mediating the effects of nicotine in the mesolimbic dopamine system in mice lacking the ,4 subunit. We show that there are two distinct populations of receptors in the substantia nigra and striatum by using autoradiographic labelling with 125I ,-conotoxin MII. These receptors are comprised of the ,4, ,2 and ,6 nAChR subunits and non-,4, ,2, and ,6 nAChR subunits. Non-,4 subunit-containing nAChRs are located on dopaminergic neurons, are functional and respond to nicotine as demonstrated by patch clamp recordings. In vivo microdialysis performed in awake, freely moving mice reveal that mutant mice have basal striatal dopamine levels which are twice as high as those observed in wild-type mice. Despite the fact that both wild-type and ,4 null mutant mice show a similar increase in dopamine release in response to intrastriatal KCl perfusion, a nicotine-elicited increase in dopamine levels is not observed in mutant mice. Locomotor activity experiments show that there is no difference between wild-type and mutant mice in basal activity in both habituated and non-habituated environments. Interestingly, mutant mice sustain an increase in cocaine-elicited locomotor activity longer than wild-type mice. In addition, mutant mice recover from depressant locomotor activity in response to nicotine at a faster rate. Our results indicate that ,4-containing nAChRs exert a tonic control on striatal basal dopamine release, which is mediated by a heterogeneous population of nAChRs. [source] Ca2+ - and thromboxane-dependent distribution of MaxiK channels in cultured astrocytes: From microtubules to the plasma membraneGLIA, Issue 12 2009J. W. Ou Abstract Large-conductance, voltage- and Ca2+ -activated K+ channels (MaxiK) are broadly expressed ion channels minimally assembled by four pore-forming ,-subunits (MaxiK,) and typically observed as plasma membrane proteins in various cell types. In murine astrocyte primary cultures, we show that MaxiK, is predominantly confined to the microtubule network. Distinct microtubule distribution of MaxiK, was visualized by three independent labeling approaches: (1) MaxiK,-specific antibodies, (2) expressed EGFP-labeled MaxiK,, and (3) fluorophore-conjugated iberiotoxin, a specific MaxiK pore-blocker. This MaxiK, association with microtubules was further confirmed by in vitro His-tag pulldown, co-immunoprecipitation from brain lysates, and microtubule depolymerization experiments. Changes in intracellular Ca2+ elicited by general pharmacological agents, caffeine or thapsigargin, resulted in increased MaxiK, labeling at the plasma membrane. More notably, U46619, an analog of thromboxane A2 (TXA2), which triggers Ca2+ -release pathways and whose levels increase during cerebral hemorrhage/trauma, also elicits a similar increase in MaxiK, surface labeling. Whole-cell patch clamp recordings of U46619-stimulated cells develop a ,3-fold increase in current amplitude indicating that TXA2 stimulation results in the recruitment of additional, functional MaxiK channels to the surface membrane. While microtubules are largely absent in mature astrocytes, immunohistochemistry results in brain slices show that cortical astrocytes in the newborn mouse (P1) exhibit a robust expression of microtubules that significantly colocalize with MaxiK,. The results of this study provide the novel insight that suggests that Ca2+ released from intracellular stores may play a key role in regulating the traffic of intracellular, microtubule-associated MaxiK, stores to the plasma membrane of developing murine astrocytes. © 2009 Wiley-Liss, Inc. [source] Effects of steroids on oxytocin secretion by the human prostate in vitroINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2004S. J. Assinder Summary Oxytocin (OT) concentrations are elevated in prostate tissue of patients with benign prostatic hyperplasia (BPH). Oxytocin specifically increases growth, 5 , -reductase activity and contractility in the prostate. In the rat prostatic OT concentrations are regulated by gonadal steroids, with androgens reducing but oestrogens increasing OT concentrations. The regulation of prostatic oxytocin in man is not understood. This study investigates the effects of gonadal steroids on oxytocin production by the human prostate. Primary explants (approx. 1 mm3) of prostate tissue from patients with BPH were incubated in Dulbecco's modified Eagle's media in the absence or presence of 10 nmol/L testosterone (T), 10 nmol/L dihydrotestosterone (DHT), T or DHT plus 100 nmol/L of the anti-androgen cyproterone acetate (CPA), 55 pmol/L diethylstilbestrol (DES), or DES plus DHT. The amount of oxytocin secreted into the media after 3 days was measured by radioimmunoassay. Testosterone and DHT significantly increased oxytocin concentrations secreted into the media from 0.86 ± 0.11 ng/g of tissue (control) to 1.51 ± 0.14 ng/g (p < 0.01) and 1.54 ± 0.13 ng/g (p < 0.05), respectively. Incubation of tissue samples with CPA resulted in oxytocin concentrations similar to control levels. Treatment with DES caused a significant increase from 1.99 ± 0.71 to 3.98 ± 1.36 ng/g (p < 0.05). A similar increase was measured in media of tissue incubated in DES plus DHT (p < 0.001). The results demonstrate that, unlike the rat where androgens decrease oxytocin, in hyperplastic human prostate tissue both androgens and oestrogens increase oxytocin. This imbalance in the regulation of oxytocin may result in promoting prostatic overgrowth in the pathogenesis of BPH. [source] Connexin 43 Is Required for the Anti-Apoptotic Effect of Bisphosphonates on Osteocytes and Osteoblasts In Vivo,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2008Lilian I Plotkin Abstract Connexin (Cx)43 is required for inhibition of osteocyte and osteoblast apoptosis by bisphosphonates in vitro. Herein, we evaluated its requirement for the in vivo actions of bisphosphonates using mice in which Cx43 was deleted specifically from osteocytes and osteoblasts (Cx43,Ob,Ot/, mice). Effective removal of Cx43 was confirmed by the presence of the deleted form of the gene and by reduced mRNA and protein expression in osteoblastic cells and bones obtained from Cx43,Ob,Ot/, mice. The amino-bisphosphonate alendronate (2.3 ,mol/kg/d) was injected daily into 5-mo-old female mice (n = 6,11) for 31 days, starting 3 days before implantation of pellets releasing the glucocorticoid prednisolone (2.1 mg/kg/d). Cx43,Ob,Ot/, mice and their littermates (Cx43fl/,, Cx43,Ob,Ot/+, and Cx43fl/+) gained bone with similar kinetics and exhibited identical bone mass from 2 to 4.5 mo of age, indicating that Cx43 deletion from osteocytes and mature osteoblasts does not impair bone acquisition. In addition, prednisolone induced a similar increase in osteocyte and osteoblast apoptosis in Cx43,Ob,Ot/, or in control Cx43fl/, littermates. However, whereas alendronate prevented prednisolone-induced apoptosis in control Cx43fl/, mice, it was ineffective in Cx43,Ob,Ot/, mice. In contrast, alendronate inhibited glucocorticoid-induced bone loss in both type of animals, suggesting that inhibition of resorption is the predominant effect of alendronate against the early phase of glucocorticoid-induced bone loss. Taken together with earlier in vitro evidence, these findings show that Cx43 is required for the anti-apoptotic effect of bisphosphonates on osteocytes and osteoblasts. [source] The Economics of Voluntary Traceability in Multi-Ingredient Food ChainsAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 1 2010Diogo M. Souza-Monteiro The consumption of multi-ingredient foods is increasing across the globe. Traceability can be used as a tool to gather information about and manage food safety risks associated with these types of products. The authors investigate the choice of voluntary traceability in three-tiered multi-ingredient food supply chains. They propose a framework based on vertical control and agency theory to model three dimensions of traceability systems: depth, breadth, and precision. Their analysis has three main results. First, full traceability is feasible as long as there are net benefits to a downstream firm that demands traceability across all ingredients. Second, horizontal network externalities are positive because an increase in the level of traceability in one ingredient requires a similar increase in others. Finally, vertical network effects will be positive insofar as willingness to pay and probabilities of food safety hazards increase. [EconLit Classification: Q130, L140]. © 2010 Wiley Periodicals, Inc. [source] Induction of Glycerol Phosphate Dehydrogenase Gene Expression During Seizure and AnalgesiaJOURNAL OF NEUROCHEMISTRY, Issue 4 2000Wolfgang A. Link Abstract: Using mRNA differential display, we found that the gene for NAD+ -dependent glycerol phosphate dehydrogenase (GPDH; EC 1.1.1.8) is induced in rat brain following seizure activity. Northern blot and in situ hybridization analysis confirmed the differential display results; they also showed, in a separate model of neuronal activation, that after thermal noxious stimulation of the hind-paws, a similar increase in GPDH mRNA occurs in the areas of somatotopic projection in the lumbar spinal cord. Surprisingly, administration of analgesic doses of morphine or the nonsteroidal antiinflammatory drugs aspirin, metamizol (dipyrone), and indomethacin also increased GPDH mRNA levels in rat spinal cord. The opioid receptor antagonist naloxone completely blocked morphine induction of GPDH but had no effect on GPDH induction by noxious heat stimulation or metamizol treatment, implicating different mechanisms of GPDH induction. Nevertheless, in all cases, induction of the GPDH gene requires adrenal steroids and new protein synthesis, as the induction was blocked in adrenalectomized rats and by cycloheximide treatment, respectively. Our results suggest that the induction of the GPDH gene upon peripheral noxious stimulation is related to the endogenous response to pain as it is mimicked by exogenously applied analgesic drugs. [source] Differential Increase in Taurine Levels by Low-Dose Ethanol in the Dorsal and Ventral Striatum Revealed by Microdialysis With On-Line Capillary ElectrophoresisALCOHOLISM, Issue 7 2004A Smith Ethanol increases taurine efflux in the nucleus accumbens or ventral striatum (VS), a dopaminergic terminal region involved in positive reinforcement. However, this has been found only at ethanol doses above 1 g/kg intraperitoneally, which is higher than what most rats will self-administer. We used a sensitive on-line assay of microdialysate content to test whether lower doses of ethanol selectively increase taurine efflux in VS as opposed to other dopaminergic regions not involved in reinforcement (e.g., dorsal striatum; DS). Adult male rats with microdialysis probes in VS or DS were injected with ethanol (0, 0.5, 1, and 2 g/kg intraperitoneally), and the amino acid content of the dialysate was measured every 11 sec using capillary electrophoresis and laser-induced fluorescence detection. In VS, 0.5 g/kg ethanol significantly increased taurine levels by 20% for 10 min. A similar increase was seen after 1 g/kg ethanol, which lasted for about 20 min after injection. A two-phased taurine efflux was observed with the 2.0 g/kg dose, where taurine was increased by 2-fold after 5 min but it remained elevated by 30% for at least 60 min. In contrast, DS exhibited much smaller dose-related increases in taurine. Glycine, glutamate, serine, and ,-aminobutyric acid were not systematically affected by lower doses of ethanol; however, 2 g/kg slowly decreased these amino acids in both brain regions during the hour after injection. These data implicate a possible role of taurine in the mechanism of action of ethanol in the VS. The high sensitivity and time resolution afforded by capillary electrophoresis and laser-induced fluorescence detection will be useful for detecting subtle changes of neuronally active amino acids levels due to low doses of ethanol. [source] Formation of 4-hydroxynonenal (4-HNE) in frozen mackerel (Scomber scombrus) in the presence and absence of green teaJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008Rabia Alghazeer Abstract BACKGROUND: Aldehydes are secondary lipid oxidation products formed during processing and storage of food. 4-Hydroxynonenal (4-HNE) is a major toxic lipid peroxidation product which has been extensively investigated in the clinical field but less so in food products. The aim of the present study was to investigate the formation of aldehydes in stored frozen fish (Atlantic mackerel, Scomber scombrus) with and without antioxidant (green tea). RESULTS: The presence of 4-HNE in frozen fish was detected for the first time. 4-HNE was extracted from frozen fish and identified using high-performance liquid chromatography and liquid chromatography/mass spectrometry. The amount of 4-HNE increased throughout storage for 26 weeks at , 10 °C in the absence of antioxidant. A significant decrease was observed in fish samples stored at ,10 °C with green tea. Minimal amounts of 4-HNE were formed in fish stored at ,80 °C. A similar increase in 4-HNE was found for methyl linoleate and extracted fish oil exposed to UV irradiation. CONCLUSION: The toxic aldehyde 4-HNE can be formed in badly stored frozen mackerel and is an indicator of reduced texture quality and nutritional value of fish. Addition of instant whole green tea as an antioxidant can provide a cheap and effective way of enhancing safety, especially in developing countries. Copyright © 2008 Society of Chemical Industry [source] Variations in the contents of heavy metals in arable soils of a major urban wetland inlet drainage system of Lake Victoria, UgandaLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 2 2010Jolocam Mbabazi Abstract Little is known about the effects of urbanization on the chemical quality of soils in suburban wetland inlet drainage systems to the Uganda side of Lake Victoria, on which food crops are extensively grown. It is feared that pollution in the soils might eventually enter food chains through such crops being consumed by urban populations unaware of their occurrence. Soil samples were collected from cultivated areas of a major wetland drainage system (Nakivubo Channel), at Kampala, Ubanda, near Lake Victoria and from a rural control wetland site (Senge). The soil from this site had similar properties as those from the urban test site (i.e., soil texture; porosity; humus content). Analysis of heavy metals with atomic absorption spectrophotometry (AAS) yielded the following soil concentration ranges: manganese (190,780), cadmium (<0.001,1.0), zinc (6.0,10.0) and lead (10,20 mg kg,1) dry weight for the control site, and 450,900, 1.0,2.0, 131,185, 40,60 mg kg,1 dry weight, respectively, for the urban wetland, indicative of relatively heavy metal pollution in the suburban drainage system. Heavy metal levels in cocoyam (Colocasia Esculenta) and sugarcane (Saccharum Officinarum) grown on both wetland soils also were evaluated via AAS with a modified wet-acid-digestion technique. The results highlighted high cadium and lead levels (P , 0.0003) in the crops from urban wetland cultivation. Cadmium and lead concentrations in cocoyam from urban wetland soils exceeded those from the control site by 0.17 and 3.54 mg kg,1, respectively. The corresponding results for sugarcane indicated a similar increase of 0.56 and 2.14 mg kg,1 of juice extract. Cadmium and lead levels in both urban wetland crops were higher than the maximum permissible limits of the Codex Alimentarius Commission, indicating that these concentrations pose potential health risks to urban consumers, and call for early counter-measures to combat urban pollution entering the lake. [source] Hyperglycemia Stimulates a Sustained Increase in Hydraulic Conductivity In Vivo without Any Change in Reflection CoefficientMICROCIRCULATION, Issue 7 2007RACHEL M. PERRIN ABSTRACT Objective: Increased microvascular permeability contributes to the development of diabetic microvascular complications and diabetic vasculopathy is correlated with blood glucose levels. The mechanisms underlying increased permeability, however, are poorly understood. Methods: The Landis-Michel technique was used to measure water permeability (hydraulic conductivity, Lp) and macromolecular permeability (reflection coefficient, ,) of exchange capillaries in frogs and rats. Results: Dialysed normoglycemic plasma from diabetic patients had no effect on Lp. The same plasma with 20 mM glucose increased hydraulic conductivity from (mean ± SEM × 10,7 cm · s,1· cm H2O,1) 5.73 ± 2.01 to 13.09 ± 2.67 (P < .01). Nondiabetic control plasma did not affect Lp, but addition of 20 mM glucose increased Lp to a similar degree. The effect of glucose alone was examined. Glucose at 20 mM increased Lp, from 2.82 ± 0.61 to 4.71 ± 1.35 × 10, 7 cm · s, 1· cm H2O,1 (P = .002, n = 13). A similar increase was seen in rat mesenteric microvessels, from 1.04 ± 0.40 in control perfusions to 2.18 ± 0.56, P < .05. The microvascular macromolecular reflection coefficient in all the above experiments was unaltered. The use of specific inhibitors indicated that the glucose-induced increased Lp did not appear to be mediated through protein kinase C (PKC), free radical generation, glucose metabolism, or albumin glycation. Conclusions: These data suggest that hyperglycemia induced increased apparent protein permeability may be secondary to a glucose-mediated change in macromolecular convective flux rather than any change in protein permeability per se. The authors speculate that the increased microvascular permeability to water in vivo is mediated by direct interaction of glucose with the endothelial cells (perhaps with the glycocalyx). [source] Evidence for the adaptive evolution of the carbon fixation gene rbcL during diversification in temperature tolerance of a clade of hot spring cyanobacteriaMOLECULAR ECOLOGY, Issue 5 2003S. R. Miller Abstract Determining the molecular basis of enzyme adaptation is central to understanding the evolution of environmental tolerance but is complicated by the fact that not all amino acid differences between ecologically divergent taxa are adaptive. Analysing patterns of nucleotide sequence evolution can potentially guide the investigation of protein adaptation by identifying candidate codon sites on which diversifying selection has been operating. Here, I test whether there is evidence for molecular adaptation of the carbon fixation gene rbcL for a clade of hot spring cyanobacteria in the genus Synechococcus that has diverged in thermotolerance. Amino acid replacements during Synechococcus radiation have resulted in an increase in the number of hydrophobic residues in the RbcLs of more thermotolerant strains. A similar increase in hydrophobicity has been observed for many thermostable proteins. Maximum likelihood models which allow for heterogeneity among codon sites in the ratio of nonsynonymous to synonymous nucleotide substitutions estimated a class of amino acid sites as a target of positive selection. Depending on the model, a single amino acid site that interacts with a flexible element involved in the opening and closing of the active site was estimated with either low or moderate support to be a member of this class. Site-directed mutagenesis approaches are being explored in order to directly test its adaptive significance. [source] Molecular control of mitochondrial function in preimplantation mouse embryosMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2005Jacob Thundathil Abstract Mitochondria play a key role in a number of physiological events during all stages of life, including the very first stages following fertilization. It is, therefore, important to understand the mechanisms controlling mitochondrial activity during early embryogenesis to determine their role in development outcome. The objective of this study was to investigate the molecular control of mitochondrial transcription and mitochondrial DNA (mtDNA) replication in mouse preimplantation embryos. We estimated the mtDNA copy number and characterized the expression patterns of two mitochondrial genes and several nuclear genes that encode mitochondrial transcription and replication factors throughout preimplantation development. Mitochondrial gene transcripts were present in larger quantities in morula and blastocyst stage embryos relative to other stages. A significant increase in the amount of mRNA for nuclear genes encoding mtDNA transcription factors was observed in eight-cell stage embryos. Although a similar increase in the mRNA levels of nuclear genes encoding mtDNA replication factors was observed in morula and blastocyst stage embryos, the number of mtDNA molecules remained stable during preimplantation stages, suggesting that nuclear-encoded mitochondrial transcription factors are involved in the regulation of mtDNA transcription during early development. Although transcripts of replication factors are abundant at the morula and blastocyst stage, mtDNA replication did not occur until the blastocyst stage, suggesting that the inhibition of mtDNA replication is controlled at the post-transcriptional level during early embryogenesis. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Changes in the impact factor of anesthesia/critical care journals within the past 10 yearsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2000J. Boldt Background: The impact factor (IF) is published by the Institute for Scientific Information (ISI). There is a tendency to assess quality of scientific journals with the help of the IF. An analysis of the changes in the IF over time in the different specialities may help to further enlighten the worth and problems of the IF. Methods: The IFs listed under the subheadings Anesthesiology and Emergency Medicine & Critical Care in the Science Citation Index , Journal Citation Report were descriptively analysed over the past 10 years. Additionally, IFs of some other important journals (subheadings Surgery, Cardiovascular, General Medicine) were analysed. Results: The IF of most of the journals showed a constant increase over the years (average in Anesthesiology: +65%; average in Emergency Medicine & Critical Care: +145%). IFs of the highest ranked journals of other specialities showed a similar increase over the years (average in surgical journals: +56%; average in cardiac journals: +59%; average in general journals: +40%). More Anesthesiology and Emergency Medicine & Critical Care journals originated from the USA show an IF >2.0 over the past 10 years than do European journals. Conclusion: Although the value of the IF is highly controversial, it is a frequently used tool to assess rating of a medical journal. Anesthesiology and Emergency Medicine & Critical Care journals showed a continuous increase in the IF over the past 10 years. [source] Bilirubin influence on oxidative lung damage and surfactant surface tension propertiesPEDIATRIC PULMONOLOGY, Issue 3 2004Carlo Dani MD Abstract To study the hypothesis that hyperbilirubinemia might reduce in vivo oxidative lung damage while also diminishing lung surfactant surface tension properties during acute lung injury, we performed a randomized study in a rabbit model of acute lung injury. Twenty rabbits were randomized to receive bilirubin or saline intravenously. Acute lung injury was induced by lung lavages with saline. Lung tissue oxidation was evaluated by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and protein carbonyls (PC) in bronchial aspirate (BA) samples. Surface surfactant activity was studied in BA samples using a capillary surfactometer. Bilirubin BA concentration increased in bilirubin-treated rabbits, while it remained undetectable in controls. A similar increase in TH, AOPP, and PC bronchial aspirate concentrations was found in both the study and control groups, while surfactant surface activity was lower in the bilirubin than in the control group. We conclude that during hyperbilirubinemia, bilirubin enters the lung tissue, where it can be detected in BA fluid. Bilirubin is not effective as an antioxidant agent and exerts a detrimental effect on lung surfactant surface tension properties. These findings may have relevance to the management of premature neonates suffering from respiratory distress syndrome and hyperbilirubinemia. Pediatr Pulmonol. © 2004 Wiley-Liss, Inc. [source] Onset of acute myocardial infarction after use of non-steroidal anti-inflammatory drugs,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2008Tarek A. Hammad MD Abstract Purpose To examine the association between cyclooxygenase-2 (COX-2) selective and traditional nonsteroidal anti-inflammatory drugs (NSAIDs) and incident acute myocardial infarction (AMI), and to address unanswered questions regarding the contour of risk over time. Methods A cohort of new NSAID users aged 40,84 years was followed for the occurrence of first AMI. Data were collected within the General Practice Research Database (GPRD) from 1 January 1997 to 31 December 2004. Results The study population included 1185 AMI events (889 probable and 296 possible) from a cohort of 283,136 patients. After adjustment for demographic and cardiovascular risk factors, the hazard ratio (HR) for AMI was significantly increased for both coxib (2.11, 95% confidence interval (CI) 1.04,4.26) and non-coxib (2.24, 95%CI 1.13,4.42) COX-2 selective NSAIDs when compared to remote exposure to NSAIDs, but was not increased for traditional NSAIDs. Stratifying exposure into the first month of use versus use beyond 1 month, the risk of AMI was increased during the first month of COX-2 selective NSAIDs use, but not later (3.43, 95%CI 1.66,7.07 and 1.88, 95%CI 0.82,4.31, respectively p -value for interaction,=,0.6). Conclusions The results suggest that the use of coxib and non-coxib COX-2 selective NSAIDs was associated with an elevated risk of AMI within the first month of exposure. Recent past exposure to NSAID was not associated with a similar increase in risk. Copyright © 2008 John Wiley & Sons, Ltd. [source] UVAI-induced Edema and Pyrimidine Dimers in Murine Skin,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2000Ronald D. Ley ABSTRACT The induction of edema and pyrimidine dimers in epidermal DNA was determined in the skin of SKH:HR1 mice exposed to graded doses of ultraviolet radiation AI (UVAI; 340,400 nm). Exposure to UVAI induced 1.6 ± 0.08 × 10,6 (mean ± standard error of mean) pyrimidine dimers per 108 Da of DNA per J/m2. Edema in irradiated animals was determined as an increase in skinfold thickness. A dose of 1.8 × 106 J/m2 of UVAI that resulted in a 50% increase in skinfold thickness (SFT50%) would have induced 1.0 × 105 dimers per basal cell genome. A similar increase in SFT induced by full spectrum solar ultraviolet radiation (290,400 nm) would accompany the induction of 11.0 × 105 pyrimidine dimers per basal cell genome. These results support a hypothesis that UVAI-induced pathological changes of the skin are mediated through the formation of nondimer photoproducts. [source] Guanosine-Induced Synaptogenesis in the Adult Brain In VivoTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 12 2009Inmaculada Gerrikagoitia Abstract Astrocytes release factors like cholesterol, apoE, and pleiotropic molecules that influence synaptogenesis in the central nervous system. In vitro studies have shown that guanosine elicits the production and further release of these synaptogenic factors. To demonstrate that such astrocytic factors are synaptogenic in vivo, osmotic pumps were implanted in primary visual cortex (VC) of Sprague-Dawley rats to deliver guanosine. Simultaneous injection of dextran amine as an anterograde tracer at the same site where the osmotic pumps were implanted enabled the morphology of the fibers emerging from the VC to be visualized as well. The guanosine-treated efferent connections from these animals showed a significant increase in the number and size of synaptic boutons along the efferent fibers when compared with controls. A similar increase in the number and size of synaptic boutons was also detected when the cortico,cortical connection to the lateral secondary visual area was studied in more detail. The ensuing morphological changes to the synapses did not show a clear preference for any particular type or site of the axonal branches that integrates this cortical connection. Moreover, the distribution of boutons along the fibers was clearly stochastic according to their size. Thus, guanosine administration appears to open up the possibility of manipulating connections to compensate for total or partial denervation. Anat Rec, 292:1968,1975, 2009. © 2009 Wiley-Liss, Inc. [source] Threshold behaviour of human axons explored using subthreshold perturbations to membrane potentialTHE JOURNAL OF PHYSIOLOGY, Issue 2 2009David Burke The present study explores the threshold behaviour of human axons and the mechanisms contributing to this behaviour. The changes in excitability of cutaneous afferents in the median nerve at the wrist were recorded to a long-lasting subthreshold conditioning stimulus, with a waveform designed to maximize the contribution of currents active in the just-subthreshold region. The conditioning stimulus produced a decrease in threshold that developed over 3,5 ms following the end of the depolarization and then decayed slowly, in a pattern similar to the recovery of axonal excitability following a discharge. To ensure that the conditioning stimulus did not activate low-threshold axons, similar recordings were then made from single motor axons in the ulnar nerve at the elbow. The findings were comparable, and behaviour with the same pattern and time course could be reproduced by subthreshold stimuli in a model of the human axon. In motor axons, subthreshold depolarizing stimuli, 1 ms long, produced a similar increase in excitability, but the late hyperpolarizing deflection was less prominent. This behaviour was again reproduced by the model axon and could be explained by the passive properties of the nodal membrane and conventional Na+ and K+ currents. The modelling studies emphasized the importance of leak current through the Barrett,Barrett resistance, even in the subthreshold region, and suggested a significant contribution of K+ currents to the threshold behaviour of axons. While the gating of slow K+ channels is slow, the resultant current may not be slow if there are substantial changes in membrane potential. By extrapolation, we suggest that, when human axons discharge, nodal slow K+ currents will be activated sufficiently early to contribute to the early changes in excitability following the action potential. [source] Exercise induces expression of leukaemia inhibitory factor in human skeletal muscleTHE JOURNAL OF PHYSIOLOGY, Issue 8 2008Christa Broholm The leukaemia inhibitory factor (LIF) belongs to the interleukin (IL)-6 cytokine superfamily and is constitutively expressed in skeletal muscle. We tested the hypothesis that LIF expression in human skeletal muscle is regulated by exercise. Fifteen healthy young male volunteers performed either 3 h of cycle ergometer exercise at ,60% of (n= 8) or rested (n= 7). Muscle biopsies were obtained from the vastus lateralis prior to exercise, immediately after exercise, and at 1.5, 3, 6 and 24 h post exercise. Control subjects had biopsy samples taken at the same time points as during the exercise trial. Skeletal muscle LIF mRNA increased immediately after the exercise and declined gradually during recovery. However, LIF protein was unchanged at the investigated time points. Moreover, we tested the hypothesis that LIF mRNA and protein expressions are modulated by calcium (Ca2+) in primary human skeletal myocytes. Treatment of myocytes with the Ca2+ ionophore, ionomycin, for 6 h resulted in an increase in both LIF mRNA and LIF protein levels. This finding suggests that Ca2+ may be involved in the regulation of LIF in endurance-exercised skeletal muscle. In conclusion, primary human skeletal myocytes have the capability to produce LIF in response to ionomycin stimulation and LIF mRNA levels increase in skeletal muscle following concentric exercise. The finding that the increase in LIF mRNA levels is not followed by a similar increase in skeletal muscle LIF protein suggests that other exercise stimuli or repetitive stimuli are necessary in order to induce a detectable accumulation of LIF protein. [source] Pre-operative vitamin B infusion and prevention of nitrous oxide-induced homocysteine increaseANAESTHESIA, Issue 7 2010L. K. Rao Summary Nitrous oxide inactivates vitamin B12 with detrimental consequences for folate and methionine metabolism, detectable by an increase in total plasma homocysteine. We hypothesised that a pre-operative vitamin B12 and folate infusion prevents nitrous oxide-induced homocysteine increase. Sixty-three healthy patients having elective surgery were randomly allocated to receive either B-vitamin plus nitrous oxide; placebo plus nitrous oxide or placebo plus air. Fifty-nine patients completed the study. After intravenous B-vitamin infusion, plasma vitamin B12 and folate concentrations increased 35-fold and 12-fold, respectively, on the first postoperative measurement. Patients who received B-vitamins developed a similar increase (18%) in homocysteine after nitrous oxide (1.9 ,mol.l,1; 95% CI 0.2,3.6 ,mol.l,1) as those who did not (22%; 2.7 ,mol.l,1; 95% CI 0.6,4.8 ,mol.l,1). Patients not receiving nitrous oxide had no homocysteine change (0.5 ,mol.l,1; 95% CI ,0.8,1.9 ,mol.l,1), indicating that pre-operative intravenous B-vitamins may not prevent nitrous oxide-induced hyperhomocysteinaemia. [source] Radiation damage increases Purkinje neuron heterokaryons in neonatal cerebellum,ANNALS OF NEUROLOGY, Issue 1 2009Silvia Espejel PhD Objective Recent studies have shown that in radiated and bone marrow transplanted mice, bone marrow-derived cells (BMDCs) fuse with Purkinje neurons resulting in the formation of binucleated heterokaryons. Here we investigated whether radiation plays a role in the formation of Purkinje neuron heterokaryons. Methods Fused cells were identified by reporter gene expression in mice, carrying floxed LacZ (R26R-LacZ) in all cells and Cre in hematopoietic-derived cells. Cell fusion was confirmed by the presence of two nuclei. The number of fused Purkinje neurons was studied in: 1) whole-body radiated newborn and adult R26R-LacZ mice, transplanted with bone marrow cells expressing Cre; 2) in newborn and adult mice that received different doses of radiation to the head; and 3) in radiated and non-radiated newborns treated with a myeloablative drug before bone marrow transplantation. Results In neonatal, but not in adult cerebelleum, radiation,in a dose-dependent manner,induces a dramatic increase in the number of fused Purkinje neurons. Interpretation Increase recruitment of BMDCs into the cerebellum, radiation damage to cerebellar cells, or both, increase the formation of fused Purkinje cells. BMDC-Purkinje heterokaryons formation may reflect an endogeneous neuronal repair mechanism, or it could be a by-product of radiation-induced inflammation. In either case, fused Purkinje neurons increase following radiation damage in the developing cerebellum. The above observations reveal a novel consequence of head radiation in neonatal rodents. It will be interesting to determine if similar increase in the number of binucleated Purkinje neurons, occurs in children that receive radiation during early development. Ann Neurol 2009;66:100,109 [source] | ||||||||||||||||||||||||||||||||||