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At least 235 records · Page 13Linked to original sources
PubMed2003

Specific N-terminal CGRP fragments mitigate chronic hypoxic pulmonary hypertension in rats.

Chronic hypoxic pulmonary hypertension (HPH) is characterized by elevated pulmonary arterial pressure (P(PA)), right ventricular hypertrophy (RVH), pulmonary vascular remodeling, pulmonary edema and polycythemia. Currently, there is no safe and effective treatment for HPH. Calcitonin gene-related peptide (CGRP) is the most potent peptide vasodilator discovered thus far. We previously demonstrated that exogenous CGRP reversed HPH in rats. However, the CGRP1 receptor antagonist CGRP(8-37) and smaller inhibitory C-terminal CGRP fragments that can be formed by enzymatic cleavage in vivo may compromise the beneficial effects of endogenous or exogenous CGRP. We here examine the agonistic efficacy of N-terminal rat alpha-CGRP peptides containing the disulfide bridge (Cys(2)-Cys(7)) with amidated C-terminal in prevention of HPH. Chronic infusion of CGRP(1-8), CGRP(1-13), or CGRP(1-14) at 7 nmol/h/rat via the right jugular vein during 14 days of hypobaric hypoxia (10% inspired O(2)) significantly decreased the P(PA), RVH and pulmonary arterial medial thickness in comparison with controls, suggesting that these CGRP sequences can mitigate chronic HPH in rats. Systemic pressure was unchanged by infused peptides indicating no carry-over effect. In conclusion, N-terminal CGRP fragments (CGRP(1-8), CGRP(1-13) and CGRP(1-14)) may have a protective role in hypoxic pulmonary hypertension.

Animals↗
PubMed2003

Modeling alternative mitigation strategies for a hypothetical outbreak of foot-and-mouth disease in the United States.

Alternative mitigation strategies were compared during hypothetical outbreaks of foot-and-mouth disease (FMD) in the USA using a computer-simulation model. The epidemiologic and economic consequences were compared during these simulated outbreaks. Three vaccination and four slaughter strategies were studied along with two speeds of FMD virus spread among three susceptible populations of animals. The populations represented typical animal demographics in the United States. The best strategy depended on the speed of spread of FMD virus and the demographics of the susceptible population. Slaughter of herds in contact with known contagious herds was less costly than slaughtering only contagious herds. Slaughtering in 3 km rings around contagious herds was consistently more costly than other slaughter strategies. Ring vaccination in 10 km rings was judged more costly than slaughter alone in most situations. Although early ring vaccination resulted in lower government costs and duration in fast-spread scenarios, it was more costly when vaccinated animals were slaughtered with indemnity and other related slaughter costs.

Abattoirs↗
PubMed2001

Investigation of the potential for radon mitigation by operation of mechanical systems affecting indoor air.

Mitigation of radon gas and radon progeny in buildings is based largely on reducing the pressure difference between the point of the radiation source and the point of entry to indoor air. This study identifies the influence of mechanical systems, of air-conditioning and 'wet' systems of central heating as potential remediation agents in the control of radon and progeny concentrations. Air-conditioning was found to reduce radon levels in a systematic way within a few hours of start-up, to a low fraction of the immediately preceding concentration. Central heating reduced the level by around 40% of the preceding high within a few hours of start-up. Importantly for health concerns, under operating conditions of both types of system the level of radon progeny was reduced to a greater extent than the radon progenitor.

Air Conditioning↗
PubMed2000

N-acetylcysteine or trolox derivative mitigate the toxic effects of methanol on the antioxidant system of rat brain.

The effect of two compounds: N-acetylcysteine (NAC) and trolox derivative (U-83836E) on the methanol induced impairment of the antioxidant system of the rat brain was studied in male Wistar rats (approx. 250 g body weight). The animals were divided into six main groups: control group (0.5 ml of physiological saline intragastrically), NAC group (150 mg/kg intraperitoneally-i.p), U-83836E group (10 mg/kg i.p.), methanol group (3 g/kg intragastrically), NAC+methanol and U-83836E+methanol groups. In these particular groups the changes in antioxidant parameters were observed for 6,12,24,48 h and 5 and 7 days. The results proved that the use of methanol and N-acetylcysteine increased the activities of Cu,Zn-superoxide dismutase, glutathione peroxidase and glutathione reductase by about 15,15 and 41%, respectively, in comparison to the group of rats receiving methanol alone. Similarly, the level of GSH increased by about 17%, the concentration of ascorbate by 20%, while the thiobarbituric acid-reactive substances (TBA-rs) diminished to the values as in control group. The use of new antioxidant U8383E and methanol showed less beneficial effect in the measured parameters however, it serves as a better protector for the methanol induced decrease in GSH-content. These data suggest that NAC and U-83836E mitigate the toxic effects of methanol on the antioxidant system of the rat brain.

Acetylcysteine↗
PubMed2002

Buffer administration during CPR promotes cerebral reperfusion after return of spontaneous circulation and mitigates post-resuscitation cerebral acidosis.

To explore the effects of alkaline buffers on cerebral perfusion and cerebral acidosis during and after cardiopulmonary resuscitation (CPR), 45 anaesthetized piglets were studied. The animals were subjected to 5 min non-interventional circulatory arrest followed by 7 min closed chest CPR and received either 1 mmol/kg of sodium bicarbonate, 1 mmol/kg of tris buffer mixture, or the same volume of saline (n=15 in all groups), adrenaline (epinephrine) boluses and finally external defibrillatory shocks. Systemic haemodynamic variables, cerebral cortical blood flow, arterial, mixed venous, and internal jugular bulb blood acid-base status and blood gases as well as cerebral tissue pH and PCO(2) were monitored. Cerebral tissue acidosis was recorded much earlier than arterial acidaemia. After restoration of spontaneous circulation, during and after temporary arterial hypotension, pH in internal jugular bulb blood and in cerebral tissue as well as cerebral cortical blood flow was lower after saline than in animals receiving alkaline buffer. Buffer administration during CPR promoted cerebral cortical reperfusion and mitigated subsequent post-resuscitation cerebral acidosis during lower blood pressure and flow in the reperfusion phase. The arterial alkalosis often noticed during CPR after the administration of alkaline buffers was caused by low systemic blood flow, which also results in poor outcome.

Acidosis↗
PubMed2003

Untying a Lancastrian bundle: valuing ecosystems and ecosystem services for wetland mitigation.

A utility-theoretic model indicates that mitigation prices for wetland ecosystems depend on preferences and technical knowledge. Empirical analysis found gaps in respondents' knowledge about such ecosystems. Valuing wetland types requires dealing with respondents' possible misinformation, by developing tools for informing respondents or by combining service-based valuations with valid technical data.

Conservation of Natural Resources↗
PubMed2001

Incentives for mitigation investment and more effective risk management: the need for public-private partnerships.

A key question facing both well-developed industrial countries and emerging economies is how to reduce future disaster losses while still providing financial protection to victims from these events. This paper proposes a strategy for the use of cost-effective risk mitigation measures coupled with insurance and/or new capital market instruments to achieve these objectives. The mix of these measures will depend on the governance structure and the institutional arrangements in the particular country. There will always be a need for a combination of policy tools and the interaction among key interested parties from both the private and public sectors in developing a disaster management strategy. Two examples, one from US and the other from Honduras, illustrate differences between strategies that countries can adopt.

Disaster Planning↗
PubMed2000

Mitigation of dense gas releases in buildings: use of simple models.

When an accidental release of a hazardous material is considered within a safety case or risk assessment, its off-site effects are generally assessed by calculating the dispersion of vapour from the site. Although most installations handling flammables will be in the open air, many types of plant, particularly those handling toxics, are enclosed, partly to provide some form of containment and hence to mitigate the effects of any release. When such a release occurs within a building, the gas or vapour will undergo some mixing before emerging from any openings. The degree of mixing will depend upon the building geometry and the nature of the ventilation, which in turn may be modified by the leak. This situation is considered in this paper, with specific application to calculating the rate of release of a dense vapour from a building. All the calculations presented are based upon simple zone modelling, such that the region occupied by the vapour is assumed to be well mixed, and, in the isothermal case, either its concentration or its depth increases as it is fed by the gas leak. Transfer of air or gas/air mixture through the building openings is estimated by use of standard ventilation calculation methods. For the non-isothermal case, a preliminary model is presented in which it is assumed that there is complete mixing throughout the building and no wind-driven ventilation effects. A moderate release of chlorine is used as an example, and results are shown of the effects of various ventilation possibilities on the release rate to the atmosphere. In addition, comparisons are given between model results and experimental data, demonstrating the level of confidence which can be placed in the models, and also identifying areas where there is scope for further improvement.

Air Pollution, Indoor↗
PubMed2000

Mitigation of dense gas releases within buildings: validation of CFD modelling.

When an accidental release of a hazardous material is considered within a safety case or risk assessment, its off-site effects are generally assessed by calculating the dispersion of vapour from the site. Although most installations handling flammable materials will be in the open air, many types of plant, particularly those handling toxics, are enclosed, partly to provide some form of containment and hence, to mitigate the effects of any release. When such a release occurs within a building, the gas or vapour will undergo some mixing before emerging from any opening. The degree of mixing will depend upon the building geometry and the nature of the ventilation, which in turn may be modified by the leak. This situation is considered in this paper, with specific application to calculating the rate of release of a dense vapour from a building. The paper describes the application of computational fluid dynamics (CFD) techniques to modelling the release and mixing processes within buildings. Examples of validation calculations for simple geometric arrangements, as well as more complex geometries representative of an industrial site, are described. The results demonstrate the capabilities of CFD for this application but highlight the need for careful modelling of the near-wall flows and heat transfer, and need for an accurate fluid dynamics and thermodynamic representation of the release source.

Accidents, Occupational↗
PubMed1997

Can characteristics of a health care system mitigate ethnic bias in access to cardiovascular procedures? Experience from the Military Health Services System.

OBJECTIVES: This study sought to investigate the independent effect of ethnicity on the utilization of invasive cardiac procedures after acute myocardial infarction (AMI). BACKGROUND: The precise role of ethnicity in access to cardiovascular procedures is unknown, particularly because of difficulty in isolating ethnicity from financial and other socioeconomic factors. We conducted a retrospective analysis of the use of cardiac catheterization and coronary revascularization procedures after AMI in military health care beneficiaries. The Military Health Services System (MHSS) ensures equal access to care in an environment without financial incentives for procedural utilization; furthermore, socioeconomic differences between patients beyond ethnicity are minimized. METHODS: Data were analyzed from the Civilian External Peer Review Program representing abstracted chart reviews from 125 military health care facilities worldwide for all patients (1,208 white; 233 nonwhite [155 black]) with the principal or secondary diagnosis of AMI from March to September 1993. RESULTS: Rates of cardiac catheterization were similar in white and nonwhite patients (34.8 vs. 39.1%, p = 0.21). After controlling for age, gender, cardiovascular risk factors and AMI variables, including infarct size and other risk markers, there were no differences in the use of this procedure during the AMI admission in comparisons of white versus nonwhite patients (estimated odds ratio [OR] 0.96, 95% confidence interval [CI] 0.69 to 1.34) and white versus black patients (OR 1.19, 95% CI 0.80 to 1.78). However, white patients were significantly more likely than nonwhite patients to be "considered" for future cardiac catheterization (OR 1.77, 95% CI 1.19 to 2.61). Coronary revascularization within 180 days was not significantly affected by race in white versus nonwhite (OR 0.90, 95% CI 0.59 to 1.39) and white versus black patients (OR 1.11, 95% CI 0.65 to 1.89). Outcomes (30- and 180-day mortality and readmission rates) were similar for all race groups. CONCLUSIONS: There is a limited relation between ethnicity and the use of invasive cardiac procedures in the MHSS. These data raise the promise that characteristics of a health care system can mitigate ethnic bias in medicine.

Black or African American↗
PubMedDate not supplied

Does anxiety mitigate the behavioral expression of severe conduct disorder in delinquent youths?

The purpose of this article is to examine the purported attenuating effects of comorbid anxiety on conduct disturbance in a sample of youths exhibiting severe Conduct Disorder (CD). Further, we examined the differential expression of CD and comorbid anxiety in male and female youths. Seventy-nine incarcerated youths between the ages of 12 and 19 were interviewed using the Diagnostic Interview Schedule for Children. Youths were identified who exhibited CD and CD plus an anxiety disorder. In contrast to previous findings with younger, less seriously disturbed male subjects, no overall differences were found between CD anxious and CD nonanxious youths in terms of age of first offense and overall number and severity of delinquent acts. Moreover, no differences were found between males and females, and gender did not moderate the effects of comorbidity anxiety on outcome measures. Findings suggest purported mitigating effects of anxiety on conduct disturbance may be attenuated in severe forms of CD and support the notion that comorbidity across internalizing and externalizing domains of child and adolescent psychopathology may differentially impact clinical presentation of disordered behavior depending on the severity of externalizing behavioral disturbance.

Adolescent↗
PubMed2000

Osteoprotegerin mitigates tail suspension-induced osteopenia.

Osteoprotegerin (OPG) is a recently discovered protein related to the tumor necrosis factor receptor family. It has been shown to inhibit ovariectomy (ovx)-induced resorption in rats and increase bone mineral density in young mice. Tail suspension is a procedure that inhibits bone formation in maturing rodents. This study was designed to quantify OPG's effect on cortical bone formation. Fifty-four mice were assigned to one of five groups (n = 10-11/group). A baseline control group was killed on day 0 of the 10 day study. The remaining groups were: vivarium housed (nonsuspended) control mice receiving 0.3 mg/kg per day OPG; vivarium control mice receiving daily placebo injections; tail-suspended mice receiving 0. 3 mg/kg per day OPG; and tail-suspended mice receiving placebo injections. Tetracycline was administered on days 0 and 8. OPG treatment of tail-suspended mice produced mechanical properties similar to those of placebo-treated, vivarium-housed mice: structural stiffness (8.5%, 20.7%) and elastic (13.9%, 10.1%) and maximum (4.7%, 8.1%) force were increased compared with placebo controls (vivarium, suspended groups). Percent mineral composition was highly significantly greater (p < 0.001 for all comparisons) for OPG-treated mice in the femur, tibia, and humerus, relative to placebo treatment. Matrix mass was also significantly increased in the femur, although not to the same degree as mineral mass. OPG decreased the amount of femoral endocortical resorption compared with the placebo-treated groups for both vivarium (27%) and suspended (24%) mice. Administration of OPG significantly decreased endocortical formation of the tibia. Periosteal bone formation rates were not altered by OPG. OPG-mitigated tail suspension induced osteopenia not by returning bone formation to normal levels, but by inhibiting resorption and increasing percent mineral composition.

Animals↗
PubMed2003

Stress-induced apoptosis in Spodoptera frugiperda (Sf9) cells: baculovirus p35 mitigates eIF2 alpha phosphorylation.

Spodoptera frugiperda (Sf9) ovarian cells, natural hosts for baculovirus, are good model systems to study apoptosis and also heterologous gene expression. We report that uninfected Sf9 cells readily undergo apoptosis and show increased phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2alpha) in the presence of agents such as UVB light, etoposide, high concentrations of cycloheximide, and EGTA. In contrast, tunicamycin, A23187, and low concentrations of cycloheximide promoted eIF2alpha phosphorylation in Sf9 cells but without apoptosis. These findings therefore suggest that increased eIF2alpha phosphorylation does not always necessarily lead to apoptosis, but it is a characteristic hallmark of stressed cells and also of cells undergoing apoptosis. Cell death induced by the above agents was abrogated by infection of Sf9 cells with wild-type (wt) AcNPV. In contrast, Sf9 cells when infected with vAcdelta35, a virus carrying deletion of the antiapoptotic p35 gene, showed increased apoptosis and enhanced eIF2alpha phosphorylation. Further, a recombinant wt virus vAcS51D expressing human S51D, a phosphomimetic form of eIF2alpha, induced apoptosis in UVB pretreated Sf9 cells. However, infection with vAcS51A expressing a nonphosphorylatable form (S51A) of human eIF2alpha partially reduced apoptosis. Consistent with these findings, it has been observed here that caspase activation has led to increased eIF2alpha phosphorylation, while caspase inhibition by z-VAD-fmk reduced eIF2alpha phosphorylation selectively in cells exposed to proapoptotic agents. These findings therefore suggest that the stress signaling pathway determines apoptosis, and caspase activation is a prerequisite for increased eIF2alpha phosphorylation in Sf9 cells undergoing apoptosis. The findings also reinforce the conclusion for the first time that the "pancaspase inhibitor" baculovirus p35 mitigates eIF2alpha phosphorylation.

Animals↗
PubMed2003

Mitigating uranium in groundwater: prospects and limitations.

Removal of uranium(VI) by zerovalent iron has been suggested as a feasible pathway to control uranium contaminations in seepage waters. Available information in the literature however presents discrepant evidence on the process responsible for the mitigation effect. On basis of an EH-pH diagram of uranium and iron, it is outlined that these discrepancies may be explained by the aqueous chemistry of uranium and iron. Additional effects contributing to the complexity of the system are given. Solubilization experiments using scrap iron together with water works sludge, MnO2, and pyrite indicate that U(VI) is immobilized by iron corrosion products after about 50 days.

Iron↗
PubMed2005

Analysis of atmospheric sesquiterpenes: sampling losses and mitigation of ozone interferences.

Atmospheric standards containing parts-per-billion levels of 14 semivolatile hydrocarbon compounds, including eight sesquiterpenes (SQTs) (longipinene, alpha-copaene, isolongifolene, alpha-cedrene, trans-caryophyllene, aromadendrene, alpha-humulene, delta-cadinene), two oxidized sesquiterpenoids (cisnerolidol, trans-nerolidol), one biogenic ketone (geranylacetone) and three aromatic compounds (1,3,5-triisopropylbenzene, diphenylmethane, nonylbenzene), were collected onto four solid adsorbent materials at increasing ozone mixing ratios (0-100 ppbv 03) for analysis by thermodesorption-gas chromatography. Substantial sampling losses of up to >90% were found for the most reactive SQT, even at the lowest ozone level investigated of 20 ppbv. Loss rates from the ozone-SQT reaction were used to derive estimates of gas-phase ozone reaction rate constants for longipinene, alpha-copaene, isolongifolene, geranylacetone, aromadendrene, delta-cadinene, cis-nerolidol, and transnerolidol. Three different ozone mitigation techniques were investigated to prevent these sampling losses. These strategies included (a) placing glass fiber filters impregnated with sodium thiosulfate (Na2S2O3) into the sampling line, (b) titration of ozone in the sampling stream with nitric oxide (NO), and (c) catalytically removing ozone with a commercially available manganese dioxide (MnO2) catalyst. All three techniques reduced ozone-mixing ratios from 100 ppbv to <0.6 ppbv at sampling flow rates of 1 L min(-1). When the Na2S2O3 filters and the NO-titration techniques were applied, SQT loss rates decreased from 25-60% to 0-5% for most SQT compounds and from >90% to approximately 10-50% for the two most reactive compounds at ozone mixing ratios of up to 100 ppbv. The commercial manganese dioxide scrubber, however, caused complete analyte losses (>98%) even at 0 ppbv ozone. These results underline the need and present applicable techniques for removal of ozone in air samples for SQT analysis by solid adsorption techniques.

Adsorption↗
PubMed2002

Mitigation of the action of wheat allergen by acidic oxidative potential water.

BACKGROUND: Acidic oxidative potential water (AOPW) is strongly acidic, and contains active oxygen species and thus exhibits an oxidative potential to cause biochemical alterations of wheat proteins. METHODS: A commercial wheat allergen extract was treated with AOPW, and then analysed by means of SDS-PAGE and the skin prick test in IgE-mediated wheat allergic patients. RESULTS: The wheat extract comprised 70 kDa, 32 kDa and 30 kDa fractions, and the protein in the 70 kDa fraction was broken down into less than 14 kDa fractions by AOPW. AOPW mitigated 39% of the wheal reaction to the wheat extract in the skin prick test. CONCLUSION: AOPW may be useful for enhancing the digestibility and lowering the allergenicity of wheat proteins.

Adult↗
PubMed1993

Mitigating effects of combined prenatal and postnatal exposure to ethanol on learned persistence in the weanling rat: a replication under high-peak conditions.

Replicating an earlier report under low-peak blood ethanol concentration (BEC) conditions, weanling rats, exposed in utero or postnatally to levels of ethanol that resulted in high-peak BECs, showed an attenuated partial reinforcement extinction effect, whereas pups exposed both pre- and postnatally did not differ from controls. Also supporting earlier work, postnatal exposure resulted in significantly reduced brain weight and had effects on hippocampal measures. These results from the combined-exposure group, along with earlier work, point to a possible mitigating influence in the rat of prenatal exposure to ethanol on the behavioral effects of postnatal exposure. They suggest that a protective factor may be operating, akin to the proactive immunoreactive effects of heat shock proteins shown in recent work at the cellular and hippocampal levels.

Animals↗
PubMed2006

Terror management and religion: evidence that intrinsic religiousness mitigates worldview defense following mortality salience.

Terror management theory suggests that people cope with awareness of death by investing in some kind of literal or symbolic immortality. Given the centrality of death transcendence beliefs in most religions, the authors hypothesized that religious beliefs play a protective role in managing terror of death. The authors report three studies suggesting that affirming intrinsic religiousness reduces both death-thought accessibility following mortality salience and the use of terror management defenses with regard to a secular belief system. Study 1 showed that after a naturally occurring reminder of mortality, people who scored high on intrinsic religiousness did not react with worldview defense, whereas people low on intrinsic religiousness did. Study 2 specified that intrinsic religious belief mitigated worldview defense only if participants had the opportunity to affirm their religious beliefs. Study 3 illustrated that affirmation of religious belief decreased death-thought accessibility following mortality salience only for those participants who scored high on the intrinsic religiousness scale. Taken as a whole, these results suggest that only those people who are intrinsically vested in their religion derive terror management benefits from religious beliefs.

Adaptation, Psychological↗