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PubMed1990

Concentrations of Na+ and K+ in serum and uterine flushings of ovariectomized, pregnant and cyclic rats when treated with extracts of Hibiscus rosa sinensis flowers.

The effect of 50% ethanol and benzene extracts of Hibiscus rosa sinensis flowers was studied on the concentration of Na+ and K+ in the serum and uterine flushings of ovariectomized, mated and cyclic rats. In ovariectomized rats, both extracts given alone did not alter the K+ content of the uterine flushings but when administered with estradiol dipropionate (EDP), a partial antagonism was observed when compared to EDP given alone. Conjoint treatment of extracts with EDP plus progesterone did not induce any significant change. In mated rats, both extracts did not alter the concentration of Na+ on the day of implantation but decreased significantly the concentration of K+ in uterine fluid. In cyclic rats, the administration of the extracts for 6 and 12 days did not cause any significant change in the concentration of K+ of uterine flushings but their administration for 18 days caused a significant decrease. In all three experiments, the concentration of Na+ in uterine flushings and of Na+ and K+ of serum did not show any significant changes.

Animals↗
PubMed2005

Evaluation of soil flushing potential for clean-up of desert soil contaminated by industrial wastewater.

The flushing potential of a desert loess soil contaminated by the flame retardant Tetrabromobisphenol A (TBBPA), chloride (Cl(-)) and bromide (Br(-)) was studied in undisturbed laboratory column experiments (20 cm diameter, 45 cm long) and a small field plot (2 x 2 m). While the soluble inorganic ions (Cl(-) and Br(-)) were efficiently flushed from the soil profile after less than three pore volumes (PV) of water, about 50% of the initial amount of TBBPA in the soil was also flushed, despite its hydrophobic nature. TBBPA leaching was made possible due to a significant increase in the pH of the soil solution from 7.5 to 9, which increased TBBPA aqueous solubility. The remaining TBBPA mass in the soil was not mobilized from its initial location in the topsoil due to the decrease in pH at this horizon. In situ soil flushing demonstrated that this method is a feasible treatment for reducing soil contamination at this site.

Desert Climate↗
PubMed2005

Evaluation of seasonal scale first flush pollutant loading and implications for urban runoff management.

This study investigated how the occurrence and magnitude of first flush events in stormwater may influence the effective management of urban runoff pollution. To facilitate the understanding of the first flush phenomenon on a seasonal scale, the City of San Jose, CA carried out an investigation between May 1997 and April 2000 to characterize concentrations of pollutants in local waterbodies during eight storm events. The purpose of the investigation was twofold: (1) To determine if concentrations of specific constituents in stormwater runoff are elevated during the first substantial storm of the wet season, and (2) To identify the physical and environmental conditions surrounding such events. Concentration data for total and dissolved metals, pesticides, polyaromatic hydrocarbons, anions, total suspended solids, total organic carbon, conductivity, gasoline and diesel, and volatile and semi-volatile organics were collected at over 25 sites. Monitoring data analysis focused on identifying physical and environmental conditions yielding increased levels of pollutants during the first substantial storms of the rainy season compared to other storm events. Quantitative analysis focused on metals and anions because most observations for other constituents were below detectable levels. The results suggest that first flush phenomena did not occur consistently throughout most of the stations investigated. The results further suggest that there are specific combinations of site and storm conditions that result in a first flush effect with respect to dissolved metals. Based on the results of this and related investigations, implications for urban runoff management are discussed. For example, if dissolved metals are of principal concern, it may be worthwhile to optimize existing control strategies to minimize pollutant loading from storms that are preceded by an extended dry period.

California↗
PubMed2006

Trophic structure and functioning in a eutrophic and poorly flushed lagoon in southwestern Taiwan.

Tapong Bay, a eutrophic and poorly flushed tropical lagoon, supports intensive oyster culture. Using the Ecopath approach and network analysis, a mass-balanced trophic model was constructed to analyze the structure and matter flows within the food web. The lagoon model is comprised of 18 compartments with the highest trophic level of 3.2 for piscivorous fish. The high pedigree index (0.82) reveals the model to be of high quality. The most-prominent living compartment in terms of matter flow and biomass in the lagoon is cultured oysters and bivalves, respectively. The mixed trophic impacts indicate that phytoplankton and periphyton are the most-influential living compartments in the lagoon. Comparative analyses with the eutrophic and well-flushed Chiku Lagoon and non-eutrophic tropical lagoons show that high nutrient loadings might stimulate the growth and accumulation of phytoplankton and periphyton and therefore support high fishery yields. However, net primary production, total biomass, fishery yields per unit area, and mean transfer efficiency of Tapong Bay were remarkably lower than those of Chiku Lagoon. The lower transfer efficiency likely results from the low mortality of cultured oysters and invasive bivalves from predation or the lower density of benthic feeders constrained by the hypoxic bottom water as a result of poor flushing. This might therefore result in a great proportion of flows to detritus. However, the hypoxic bottom water might further reduce the recycling of the entering detritus back into the food web. In contrast to many estuaries and tropical lagoons, poor flushing of this eutrophic tropical lagoon might induce a shift from detritivory to herbivory in the food web.

Animals↗
PubMed2006

Implications of a kinematic wave model for first flush treatment design.

A deterministic model was developed to predict pollutant mass first flush and to utilize it for better design of best management practices (BMPs) that focus on treating the first flush. The model used the kinematic wave equation to calculate flow and mass transport, and erosion equations to calculate pollutant concentrations, which were assumed to be from a short and a long term source. The model parameters were calibrated with a parameter estimation procedure using three years' monitoring data from a highway runoff site in west Los Angeles. The simulation results showed that there exists an optimum watershed size to maximize first flush. Contours of watershed length, developed from simulations for different conditions of rainfall and watershed geometry, can be used to design runoff collection systems for highways and parking lots to maximize first flush.

Models, Theoretical↗
PubMed1997

Effect of flush-perfusion on vascular endothelial and smooth muscle function.

BACKGROUND: The aim of this study was to investigate how much perfusion pressure an artery can tolerate without significant loss of endothelium-dependent relaxation (EDR) and vascular contractility. METHODS: The abdominal aortas of 396 Sprague-Dawley rats were used. One hundred twenty aortas were flush-perfused for 1 or 5 minutes with cold St. Thomas' Hospital cardioplegic (STHC) solution or with the same solution but modified by the addition of 3.5% dextran 40. Three perfusion pressures were tested: 50, 100, and 150 mm Hg. Two hundred eighty vessels were subjected to pressures of 50, 150, or 300 mm Hg using saline or STHC solution at 22 degrees C or STHC solution at 4 degrees C, for 10 or 60 seconds. The vessels were investigated in organ baths. Contractility was tested with the thromboxane analogue U-46619, acetylcholine was used to investigate EDR, and papaverine to elicit endothelium-independent relaxation. RESULTS: Flush-perfusion with cold STHC solution for 5 minutes at a perfusion pressure of 50 or 100 mm Hg affected neither contractility nor EDR. Vessels exposed to a flush-perfusion pressure of 150 mm Hg for 1 or 5 minutes lost 39% (p < 0.001) and 53% (p < 0.001) of their contractility, respectively. Flush-perfusion at 150 mm Hg for 1 minute did not affect EDR, whereas 5 minutes' perfusion caused a reduction of 7% (p < 0.05). A repetition of these experiments using STHC solution with 3.5% dextran 40 added gave no significantly different results. The impairment in contractility and EDR seen after perfusion at 150 mm Hg for 5 minutes disappeared after transplantation and reperfusion for 7 days. The vessels could be distended with saline or STHC solution at a pressure of 150 mm Hg without affecting contractility at 22 degrees C. At 4 degrees C, however, this pressure was harmful to contractility. Distention at a pressure of 300 mm Hg almost abolished contractility and 7 days after transplantation there had not yet been any recovery of contractility, but 30 days after transplantation the grafts had regained their normal contractility. CONCLUSIONS: Cold STHC solution, with or without dextran 40, can be used with a perfusion pressure of 100 but not 150 mm Hg without impairing EDR or vascular smooth muscle function.

Animals↗
PubMed1999

Effects of cardioplegic flushing, storage, and reperfusion on coronary circulation in the pig.

BACKGROUND: The aim of the study was to investigate how flush-perfusion of the heart with cold cardioplegic solution, 2 or 12 hours of cold ischemic storage, and 24 hours of reperfusion affect coronary endothelial function and coronary vascular resistance. METHODS: Porcine coronary arterial endothelial and smooth muscle function was studied in organ baths. An adult porcine working heart model was used to investigate coronary vascular resistance after 24 hours of reperfusion. RESULTS: Flushing the heart with 1 L of St. Thomas' cardioplegic solution, using a perfusion pressure of 60 to 65 mm Hg, significantly reduced endothelium-dependent relaxation. Flushing followed by 12 hours of storage gravely impaired endothelium-dependent relaxation, and 24 hours of reperfusion worsened it still more. CONCLUSIONS: Flushing the heart with cold cardioplegic solution impairs endothelium-dependent relaxation, as does prolonged cold ischemic storage. Reperfusion of injured coronary endothelium may injure it still more. A correlation was found (p < 0.001) between high coronary vascular resistance and low endothelium-dependent relaxation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2002

[Effects of estrogen replacement therapy on reactivity to stress in menopausal women with and without hot flushes].

BACKGROUND: To asses if the hot flushes during menopause are associated with an abnormal cardivascular reactivity to stress. We also aimed to evaluate the effect of hormone replacement therapy (HRT) on reactivity to stress in menopausal women. PATIENTS AND METHOD: Experimental study including 28 healthy menopausal women with hot flushes (12 on HRT) and 20 without flushes (6 on HRT). Parameters evaluated included determination of systolic and diastolic blood pressure, heart rate, percentage of decrease of peripheral pulse volume, skin conductance level and frecuency of inespecific cutaneous responses. All studies were performed prior to and after 4-6 months under HRT therapy. RESULTS: Menopausal women reporting hot flashes showed the highest electrodermal activity in front of stress. HRT therapy led to a decreased physiological reactivity in menopausal women, especially reactivity to stressors. CONCLUSIONS: Hot flushes during menopause indicate an increased level of cardiovascular reactivity to stress situations, hence a higher cardiovascular risk.

Adult↗
PubMed2002

Simulated formation and flow of microemulsions during surfactant flushing of contaminated soil.

Contamination of groundwater resources by non-aqueous phase liquids (NAPLs) has become an issue of increasing environmental concern. This study investigated the formation and flow of microemulsions during surfactant flushing of NAPL-contaminated soil using the finite difference model UTCHEM, which was verified with our laboratory experimental data. Simulation results showed that surfactant flushing of NAPLs (i.e., trichloroethylene and tetrachloroethylene) from the contaminated soils was an emulsion-driven process. Formation of NAPL-in-water microemulsions facilitated the removal of NAPLs from contaminated soils. Changes in soil saturation pressure were used to monitor the mobilization and entrapment of NAPLs during surface flushing process. In general, more NAPLs were clogged in soil pores when the soil saturation pressure increased. Effects of aquifer salinity on the formation and flow of NAPL-in-water microemulsions were significant. This study suggests that the formation and flow of NAPL-in-water microemulsions through aquifer systems are complex physical-chemical phenomena that are critical to effective surfactant flushing of contaminated soils.

Models, Theoretical↗
PubMed1980

Blockade of chlorpropamide alcohol flush by aspirin.

The blocking effects of aspirin, chlorpheniramine, and cimetidine were tested against the flush provoked by alcohol in twenty-four chlorpropamide-treated patients with non-insulin-dependent diabetes mellitus. Active preparations were compared in a double-blind manner with an indistinguishable placebo. Aspirin significantly decreased the number of patients who flushed. Five patients studied in detail all showed suppression of chlorpropamide/alcohol flush by aspirin, with a mean facial temperature increase during the flush of 2.4 degrees C after pretreatment with placebo and an increase of 0.4 degrees C after pretreatment with aspirin.

Aspirin↗
PubMed1981

Low incidence of chlorpropamide-alcohol flushing in diet-treated, non-insulin-dependent diabetes.

50 diet-treated, non-insulin-dependent diabetics were tested subjectively and objectively for chlorpropamide-alcohol flushing (CPAF) with a single challenge test. Of the 12 (24%) who reported a subjective flush, 9 (18%) also flushed when a placebo was given instead of chlorpropamide, so the true incidence of chlorpropamide-alcohol flushing was 4% (1 patient was not retested with placebo). In a control group of 21 non-diabetics, 2 showed the specific CPAF phenomenon. Temperature measurement did not improve discrimination, but it did show a faster rise in facial temperature in CPAF-positive subjects than in alcohol flushers. This study does not confirm previous higher estimates of the incidence of the CPAF phenomenon in non-insulin-dependent diabetes.

Adult↗
PubMed2000

The role of serotonin in hot flushes.

Hot flushes are experienced in those periods of the female life when estrogen levels are low. Hormone replacement therapy is thus the first choice for treatment of hot flushes. However this treatment is not always accepted or contraindicated for a variety of reasons. Estrogen (and progestogen) strongly interact with a number of neurotransmitters and this has led to a range of non-hormonal treatments including compounds that act via the noradrenergic or dopaminergic systems as well as herbal remedies. These treatments (which are shortly reviewed) are not always successful. Surprisingly, apart from treatment with some selective serotonin (5-HT) reuptake inhibitors (SSRI's), up till now, little attention is given to the strong interaction of estrogens with the serotonergic system. These interactions are shortly reviewed. Based on these interactions, a hypothesis on the genesis of hot flushes is postulated. Especially the 5-HT(2A) receptor subtype may play a key role in the occurrence of hot flushes. A number of arguments that support this hypothesis are discussed.

Estrogens↗
PubMed2003

Cimicifuga extract BNO 1055: reduction of hot flushes and hints on antidepressant activity.

Ethanolic- and isopropanolic-aqueous extracts of Cimicifuga racemosa are used for the treatment of climacteric complaints. As hot flushes and psychic complaints seem to be special targets for Cimicifuga extracts in clinical studies, these parameters were studied in experimental animals. Hot flush equivalents were measured in castrated rats as a quick increase in peripheral temperature with the aid of a transmitter implanted subcutaneously on the ventral side. The hot flush equivalents proved to respond to estrogen and the antidopaminergic drug veralipride but they were also reduced very effectively by Cimicifuga extract BNO 1055 (which is contained in Klimadynon/Menofem). In addition, an ethanolic-aqueous extract of C. racemosa was studied in the tail suspension test (TST), a behavioural test indicative for antidepressant activity. A significant decrease of the period of immobility was observed after treatment with 30 mg/kg body weight (bw) imipramine or with 50 or 100 mg/kg bw Cimicifuga extract. These findings in pharmacological tests-a reduction of the frequency of hot flush equivalents and hints on antidepressant activity of Cimicifuga extracts-are in good agreement with the therapeutical responses in climacteric women.

Animals↗
PubMed1995

Perioperative vascular flushing perfusion in acute mesenteric artery occlusion.

AIM: To evaluate in animals and patients a perioperative vascular flushing perfusion with antioxidants in order to improve postischaemic condition of the bowel and hence, to prolong the warm ischaemia tolerance time. MATERIALS: 40 rats and 10 patients with acute mesenteric artery occlusion. METHODS: Intestinal ischaemia was induced in 40 rats by clipping the superior mesenteric artery for 1 h. Thirty animals received a vascular flushing perfusion with oxygen radical scavengers (ascorbate, tocopherol or oxypurinol). Histology, ATP, ADP levels were examined in tissue biopsies and malondialdehyde, lactate dehydrogenase, alkaline phosphatase levels were measured in blood during ischaemia and 60 min after reperfusion. RESULTS: ATP restoration was particularly improved in the oxypurinol group (ATP/ADP-ratio = 2 vs. 1.2 in the control group). Malondialdehyde increase observed after reperfusion as a marker of radical induced lipid destruction was significantly attenuated (control group 160% of base level vs. 127% in the ascorbate group, 133% in the tocopherol group, 121% in the oxypurinol group). Histological alterations during ischaemia/reperfusion were markedly less extensive in the perfusion groups than in control. The patients treated perioperatively with arterial flushing perfusion had an overall mortality of 10%. CONCLUSION: Vascular flushing perfusion with oxygen radical scavengers prevents radical induced ischaemic damage and may prolong the warm ischaemic tolerance time of the intestine.

Acute Disease↗
PubMed2001

In situ algal bloom control by the integration of ultrasonic radiation and jet circulation to flushing.

A novel strategy for in situ water bloom control was applied and evaluated in Lake Senba. The proposed strategy was to integrate ultrasonic radiation and water jet circulation to an existing flushing process for reducing the growth rate of cyanobacteria and to support the flushing process by providing efficient mixing. Ten units of the system, each consisting of an ultrasonication module and a water jet circulator module, were strategically situated on the lake, and the performance was monitored for 2 years. Water bloom occurrence reflected as chlorophyll a, SS, and transparency were controlled to lower levels when the integrated system was coupled with sufficient inflow water supply to achieve the target flushing rate. Also, an improvement in the water quality such as COD and phosphorus were observed. Based on linear regression analysis, relationships between water quality parameters and inflow water volume were discussed to evaluate the proposed strategy. Of the three major water quality parameters associated with water bloom, the integrated system contributed mainly to the reduction in SS and transparency compared to chlorophyll a reduction. Improved chlorophyll a reduction may be achieved by strategies that augment effective washout of cyanobacteria during flushing.

Carbohydrates↗
PubMed2003

Rate-limited solubilization of multicomponent nonaqueous-phase liquids by flushing with cosolvents and surfactants: modeling data from laboratory and field experiments.

The impact of rate-limited mass transfer on in-situ cosolvent and single-phase microemulsion flushing for the solubilization of multicomponent nonaqueous-phase liquids (NAPLs) was investigated. Laboratory and field data from both cosolvent and microemulsion flushing studies were modeled using a one-dimensional flow, enhanced-dissolution code. Transport of the flushing agents was described with a one-dimensional advection-dispersion model; more complex heterogeneities encountered at the field scale were characterized using the superposition of two solute transport equations. Cosolvent and microemulsion flushing solubilize NAPLs by different mechanisms. The modeling results presented here show that nonequilibrium effects influence both of these processes differently. Solubilization of individual constituents by cosolvents was limited by the rate of diffusion or transport of the component through the organic phase, while the rate-limiting step for microemulsification was independent of the NAPL constituent and was likely external to the organic phase. These data indicate that by accounting for field-scale hydrodynamic variability, laboratory-measured nonequilibrium parameters may be used to accurately predict field-scale nonequilibrium NAPL solubilization. Finally, the effects of field-scale media heterogeneity are likely to dominate those of weakly rate-limited dissolution, and accurate characterization of the former may be sufficient for adequate prediction of field-scale NAPL solubilization.

Diffusion↗
PubMedDate not supplied

Inter- and intra-annual chemical variability during the ice-free season in lakes with different flushing rates and acid deposition histories.

Quantifying chemical variability in different lake types is important for the assessment of both chemical and biological responses to environmental change. For monitoring programs that emphasize a large number of lakes at the expense of frequent samples, high variability may influence how representative single samples are of the average conditions of individual lakes. Intensive temporal data from long-term research sites provide a unique opportunity to assess chemical variability in lakes with different characteristics. We compared the intra- and inter-annual variability of four acidification related variables (Gran alkalinity, pH, sulphate concentration, and total base cation concentration) in four lakes with different flushing rates and acid deposition histories. Variability was highest in lakes with high flushing rates and was not influenced by historic acid deposition in our study lakes. This has implications for the amount of effort required in monitoring programs. Lakes with high flushing rates will require more frequent sampling intervals than lakes with low flushing rates. Consideration of specific lake types should be included in the design of monitoring programs.

Acid Rain↗
PubMed2004

A biosurfactant-enhanced soil flushing for the removal of phenanthrene and diesel in sand.

In order to examine the potential of biosurfactants in soil remediation, and to investigate the effects of several operating conditions, such as flow rate, biosurfactant concentration and surfactant type, biosurfactant-enhanced soil flushing was conducted. In the biosurfactant-enhanced soil flushing process, the removal efficiency increased as the flow rate decreased. Rhamnolipid showed no effect on the removal efficiency of phenanthrene and diesel from sand in the concentration range 0.3-0.5%. However, rhamnolipid showed higher efficiencies for the removal of phenanthrene and diesel from sand than Tween 80. Based on total recovery, following an equivalent pore volume flush, it was more difficult to remove diesel than phenanthrene. In order to obtain the specific removal efficiency, more pore volumes of surfactant solution may be required in field applications. Under optimum conditions, the biosurfactant removed as much as 70% of the phenanthrene and 60% of the diesel in the sand. These results indicate that the use of biosurfactants in the flushing process is favorable, not only with respect to the environment, but also on removal efficiencies.

Environmental Pollution↗