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At least 199 records · Page 11Linked to original sources

PubMed2001

Level of dyspnoea experienced in mechanically ventilated adults with and without saline instillation prior to endotracheal suctioning.

The purpose of this study was to compare the level of dyspnoea with and without the use of 5-cc saline instillation prior to endotracheal suctioning of mechanically ventilated adults. A crossover, quasi-experimental design was used. Seventeen alert, mechanically ventilated adults were asked to rank their level of dyspnoea using the vertical visual analogue scale at specific time intervals surrounding two suctioning events. Saline was randomly assigned to be instilled prior to one of two suctioning episodes. Dyspnoea was ranked immediately after suctioning, and at 10-, 20-, and 30-minute intervals. Data were analyzed using repeated measures analysis of variance with time of measure (immediately after suctioning, 10-, 20-, and 30-minute intervals) and treatment type (with saline versus without saline instillation). The level of dyspnoea based on treatment type (with or without saline) was non-significant. Treatment type by age group interaction was significant (F(1, 15) = 5.41, P = 0.034). The nature of the interaction revealed that older patients (< or = 60 years of age) experienced less dyspnoea without saline prior to suctioning and greater dyspnoea with saline instillation as compared to the younger subjects (<60 years of age). This study documented no beneficial effects of saline. However, it did demonstrate that saline instillation might precipitate a significantly increased level of dyspnoea for up to 10 minutes after suctioning in patients older than 60 years of age. Recommendations based on the results of this study would be to avoid the use of saline instillation prior to suctioning.

Adult↗

PubMed2005

Prioritization or summation of events? Cardiovascular physiology of postprandial Dungeness crabs in low salinity.

Decapod crustaceans commonly forage in estuarine environments. The osmoregulatory mechanisms that allow them to cope with periodic episodes of low salinity have been well documented. There is less information on how ventilatory and cardiovascular mechanisms aid survival in low salinity. Prior experiments have shown that most species exhibit a tachycardia coupled with an increase in ventilation rate and oxygen uptake. However, these previous experiments were conducted on animals that were starved before experimentation in order to avoid increases in metabolism associated with digestive processes. This study investigated how the Dungeness crab Cancer magister balances the demands of physiological systems during feeding and digestion in low salinity. Cardiac and ventilatory parameters increased during feeding. When the crabs were subjected to low salinity after feeding, heart rate increased in 25% seawater (SW) but decreased in 50% SW. Instead of an expected increase in ventilation rate during low-salinity exposure, there was a decrease. Feeding was associated with an increase in sternal artery flow, with subsequent decreases in flows through the sternal and anterolateral arteries in low salinity. When low salinity was administered first, a tachycardia occurred, coupled with decreased stroke volume and cardiac output. There was also an increase in ventilation rate. When crabs were fed in low salinity, heart rate decreased in 50% SW but was maintained in 25% SW. Ventilation rate decreased when crabs fed in 50% and 25% SW. Flow through the sternal artery and anterolateral arteries decreased in low salinity, and except for transient increases while feeding, there were further decreases during digestion. Cardiac and ventilatory parameters were rapidly regained when control conditions were restored. The results suggest that events during low salinity are prioritized. Nevertheless, these alterations in physiological parameters may not be beneficial; although digestive processes did not affect osmoregulatory ability, postprandial crabs did not survive as long as starved crabs in 25% SW. The results show that the digestive state of an animal is important in modulating its physiological responses to environmental perturbations, underscoring the importance of an integrative approach to studying physiological responses at the organismal level.

Animals↗

PubMed2006

Influence of a salinity gradient on the vessel characters of the mangrove species Rhizophora mucronata.

BACKGROUND AND AIMS: Although mangroves have been extensively studied, little is known about their ecological wood anatomy. This investigation examined the potential use of vessel density as a proxy for soil water salinity in the mangrove species Rhizophora mucronata (Rhizophoraceae) from Kenya. METHODS: In a time-standardized approach, 50 wood discs from trees growing in six salinity categories were investigated. Vessel densities, and tangential and radial diameters of rainy and dry season wood of one distinct year, at three positions on the stem discs, were measured. A repeated-measures ANOVA with the prevailing salinity was performed. KEY RESULTS: Vessel density showed a significant increase with salinity, supporting its use as a prospective measure of salinity. Interestingly, the negative salinity response of the radial diameter of vessels was less striking, and tangential diameter was constant under the varying environmental conditions. An effect of age or growth rate or the presence of vessel dimorphism could be excluded as the cause of the absence of any ecological trend. CONCLUSIONS: The clear trend in vessel density with salinity, together with the absence of a growth rate and age effect, validates the potential of vessel density as an environmental proxy. However, it can only be used as a relative measure of salinity given that other environmental variables such as inundation frequency have an additional influence on vessel density. With view to a reliable, absolute proxy, future research should focus on finding wood anatomical features correlated exclusively with soil water salinity or inundation frequency. The plasticity in vessel density with differing salinity suggests a role in the establishment of a safe water transport system. To confirm this hypothesis, the role of inter-vessel pits, their relationship to the rather constant vessel diameter and the underlying physiology and cell biology needs to be examined.

Ecosystem↗

PubMed1990

Salinity tolerance of stable fly (Diptera: Muscidae).

Effects of salinity on the survival, growth, and development of stable fly, Stomoxys calcitrans (L.), were investigated in the laboratory. Larvae failed to develop to pupation when reared in media containing a salinity of 40 parts per thousand (ppt) sodium chloride (NaCl). Maximum salinity supporting larval development equaled the salinity of seawater (34 ppt); the larval LC90 was 24.2 ppt. Deleterious effects of high salinity decreased as larvae matured. Six-day-old larvae reared at a salinity of 34 ppt weighed 79% less than controls, compared with a 36% difference in 9-d-old larvae; by pupation, the difference was only 24%. Salinity did not influence the duration of larval, pupal, or adult stages. Survival of pupae was unimpaired despite a slight increase in number of pupal deformities, and normal adults emerged. Eggs were highly tolerant to saline. They hatched at salinity concentrations lethal to larvae; greater than 50% hatch occurred even when eggs were maintained at 80 ppt NaCl. Sensitivity of larvae to salinities close to that of seawater might be important for control of stable flies inhabiting marine areas.

Animals↗

PubMed2006

A randomized trial of saline hydration to prevent contrast nephropathy in chronic renal failure patients.

BACKGROUND: Contrast nephropathy (CN) is a common cause of renal dysfunction that may be prevented by saline hydration and by drugs such as theophylline or furosemide. Whether oral saline hydration is as efficient as intravenous saline hydration is unknown. The preventive efficacy of theophylline and furosemide for CN remains controversial. The purpose of the current study was to evaluate the efficacy of oral saline hydration and of intravenous saline hydration plus theophylline or furosemide for the prevention of CN. METHODS: We prospectively studied 312 patients with chronic renal failure (serum creatinine 201+/-81 micromol/l, Cockcroft clearance 37+/-12 ml/min/1.73 m(2)), who were undergoing various radiological procedures with a non-ionic, low osmolality contrast agent. Patients were randomly assigned to four arms. In arm A, patients received 1 g/10 kg of body weight/day of sodium chloride per os for 2 days before the procedure. In arm B, patients received 0.9% saline intravenously at a rate of 15 ml/kg for 6 h before the procedure. In arm C, patients received the same saline hydration as in arm B plus 5 mg/kg theophylline per os in one dose 1 h before the procedure. In arm D, patients received the same saline hydration as in arm B plus 3 mg/kg of furosemide intravenously just after the procedure. RESULTS: Patients were well-matched with no significant differences at baseline in any measured parameters. Acute renal failure, defined as an increase in serum creatinine of 44 micromol/l (0.5 mg/dl), occurred in 27 out of 312 patients (8.7%). There was no significant difference between the rate of renal failure in the different arms of the study: five out of 76 (6.6%) in arm A, four out of 77 (5.2%) in arm B, six out of 80 (7.5%) in arm C and 12 out of 79 (15.2%) in arm D. No patient had fluid overload or a significant increase in blood pressure in the 2 days following the radiological procedure. The independent predictors of CN were diabetes mellitus, high baseline serum creatinine and high systolic blood pressure. CONCLUSIONS: Oral saline hydration was as efficient as intravenous saline hydration for the prevention of CN in patients with stage 3 renal diseases. Furosemide and theophylline were not protective.

Administration, Oral↗

PubMed2001

Effects of salinity on aldicarb toxicity in juvenile rainbow trout (Oncorhynchus mykiss) and striped bass (Morone saxatilis x chrysops).

Fluctuations in several environmental variables, such as salinity, can influence the interactions between organisms and pollutants in aquatic organisms, and, therefore, affect the toxicity of xenobiotics. In this study, after 2 species of fish, rainbow trout (Oncorhynchus mykiss) and hybrid striped bass (Morone saxatilis x chrysops) were acclimated to 4 salinity regimens of 1.5, 7, 14, and 21 ppt for 1 week and then exposed to 0.5 mg/l aldicarb. Mortality, brain, and muscle cholinesterase levels were measured after 96 h. Rates of (14)C-aldicarb sulfoxide formation were determined in kidney (trout only), liver, and gill microsomes from each species acclimated to the 4 salinity regimens. Salinity significantly enhanced aldicarb toxicity, cholinesterase inhibition, and (14)C-aldicarb sulfoxide formation in rainbow trout but not in striped bass. In vitro incubations with (14)C-aldicarb and the cytochrome P450 (CYP) inhibitor, N-benzylimidazole, did not significantly alter aldicarb sulfoxide formation in tissue microsomes from either species of fish, indicating CYP did not contribute to aldicarb sulfoxidation. Salinity increased flavin-containing monooxygenase (FMO) mRNA expression and catalytic activities in microsomes of liver, gill, and kidney of rainbow trout, which was consistent with the salinity-induced enhancement of aldicarb toxicity. Salinity did not alter FMO mRNA expression and catalytic activities in striped bass, which was also consistent with the lack of an effect of salinity on aldicarb toxicity in this species. These results suggest that salinity-mediated enhancement of aldicarb toxicity is species-dependent, and at least partially due to the salinity-related upregulation of FMOs, which, in turn, increases the bioactivation of aldicarb to aldicarb sulfoxide, which is a more potent inhibitor of cholinesterase than aldicarb.

Adrenergic alpha-Antagonists↗

PubMedDate not supplied

Response of effluent-irrigated Eucalyptus grandis and Pinus radiata to salinity and vapor pressure deficits.

Effects of high vapor pressure deficit (VPD) and soil salinity on growth and physiology of Pinus radiata D. Don and Eucalyptus grandis Hill ex Maiden were studied in a five-year-old plantation irrigated with salt-enhanced effluent (2.2 dS m(-1)) or freshwater (0.2 dS m(-1)) for 14 weeks during spring and summer. Salt was then rapidly leached by over-irrigation with low-salinity effluent. Soil water and salinity, tree water stress, sap flux, substrate carbon conversion efficiency, foliage and stem growth, and foliar cations and chloride were monitored throughout the study. An average of 9 and 1 Mg ha(-1) of salt with an average hydraulic load of 660 and 780 mm was applied to the salt and control plots, respectively. Maximum soil salinity in the root zone was 5.8 and 6.8 dS m(-1) in the eucalypt and pine plots, respectively. Predawn water potential was more than twice as sensitive to increasing salinity in E. grandis as in P. radiata. The salt treatment reduced rates of leaf and stem growth of the eucalypts by 60 to 70% but had no effect on leaf and stem growth of the pines. In the eucalypts, salinity decreased mean leaf area by 26% and increased specific leaf area by 12% compared with control values, indicating less biomass per unit leaf area in the salt treatment. Salinity had no effects on these two parameters in pine. The salt treatment significantly increased mean foliar concentrations of Na and Cl in both species, and of K in the pines. Foliar Na concentration was 6-10 times higher in the eucalypts than in the pines. Lowered water potential and increased Na concentration in the eucalypts in response to salinity resulted in about a 50% reduction in the efficiency of conversion of carbon into biomass; however, three weeks after leaching the salt, there was no significant difference in efficiency of conversion of carbon into biomass between the treatments. Salinity had no effect on water use by eucalypts, but caused a nonsignificant decrease (7%) in water use by pines. As evaporative demand increased, crop factor (transpiration divided by pan evaporation) declined by up to 50 and 60% in the pines and eucalypts, respectively. We conclude that stomatal response to high VPD, not soil salinity, accounts for most of the reduction in summertime water use.

Journal Article↗

PubMed2000

A comparison of distilled water and normal saline as diluents for endobronchial administration of epinephrine in the dog.

UNLABELLED: We compared the effects of distilled water and normal saline as diluents for the endobronchial administration of epinephrine in anesthetized dogs by using a cross-over design. Six dogs received 2 mL of either normal saline or distilled water into the bronchus, and the other solution was administered 1 wk later. Eight dogs received 0.02 mg/kg epinephrine diluted in either distilled water (E + water) or normal saline (E + saline) to a total volume of 2 mL into the bronchus, and the other solution was administered 1 wk later. Normal saline or distilled water without epinephrine did not affect the plasma epinephrine concentration, mean arterial pressure (MAP), and PaO(2). The peak plasma epinephrine concentration was significantly larger after treatment with E + water (26.5 +/- 7.9 ng/mL) than after E + saline (2.1 +/- 0.7 ng/mL). E + water caused an increase in MAP of 91 +/- 24 mm Hg, whereas E + saline did not affect MAP. The maximal decrease in PaO(2) after the administration of E + water (14 +/- 5 mm Hg) was significantly greater than after E + saline (7 +/- 2 mm Hg). In conclusion, distilled water as the diluent for endobronchially administered epinephrine to a total volume of 2 mL allowed better absorption of epinephrine compared with normal saline without a serious detrimental effect on PaO(2). IMPLICATIONS: Using a small volume of distilled water as the diluent for endobronchial epinephrine administration significantly increased epinephrine absorption and arterial pressure in comparison with normal saline, without having a serious detrimental effect on PaO(2), in an anesthetized, noncardiopulmonary, resuscitation dog model.

Animals↗

PubMed1993

Hypertonic saline infusion in hemorrhagic shock treated by military antishock trousers (MAST) in awake sheep.

OBJECTIVES: To determine the effect of military antishock trousers (MAST) combined with hypertonic saline in controlled hemorrhagic shock in an awake sheep model. DESIGN: Prospective, randomized, controlled study. SETTING: University research laboratory. SUBJECTS: Healthy adult sheep (21 to 33.5 kg) were studied in four experimental groups. INTERVENTIONS: Sheep underwent cannulation of the jugular vein and the carotid artery. An indwelling catheter was also inserted into their bladders. Mean arterial, pulmonary arterial, pulmonary artery occlusion, and central venous pressures, cardiac and stroke volume indices, systemic and pulmonary vascular resistances, PaO2 and PaCO2, and serum lactate and hemoglobin concentrations were measured at baseline, after induction of hemorrhagic shock, and subsequently during resuscitative treatments of normal saline, MAST, hypertonic saline, and the combination of MAST and hypertonic saline. MEASUREMENTS: Controlled hemorrhagic shock was induced by arterial bleeding of 40 mL/kg in all animals. The sheep were randomized into four groups. In group 1 (n = 5), controlled hemorrhagic shock was treated by 5 mL/kg sodium chloride 0.9% (isotonic saline). In group 2 (n = 6), controlled hemorrhagic shock was treated by 5 mL/kg sodium chloride 7.5% (hypertonic saline). In group 3 (n = 5), controlled hemorrhagic shock was treated by MAST inflated to 40 mm Hg followed by 5 mL/kg sodium chloride 0.9%. In group 4, controlled hemorrhagic shock was treated by MAST (40 mm Hg) followed by 5 mL/kg of hypertonic saline. MAIN RESULTS: Arterial bleeding was followed by significant decreases in mean arterial pressure (87 +/- 1 to 41 +/- 4 mm Hg; p < .001), cardiac index (4.6 +/- 0.4 to 2.0 +/- 0.2 L/min/m2; p < .001), and urine output (102 +/- 30 to 13.0 +/- 7 mL/hr; p < .001), and an increase in systemic vascular resistance (1517 +/- 130 to 2601 +/- 370 dyne.sec/cm5; p < .001). MAST inflation in group 3 increased systemic vascular resistance to 3018 +/- 399 dyne.sec/cm5 (p < .05) and mean arterial pressure to 79 +/- 5 mm Hg (p < .05), while cardiac index, urine output, and lactate concentration remained unchanged. Infusion of hypertonic saline after MAST inflation (group 4) resulted in an increase in mean arterial pressure to 99 +/- 4 mm Hg (p < .001), an increase in cardiac index to 4.1 +/- 0.4 L/min/m2 (p < .001), an increase in urine output to 221 +/- 93 mL/hr (p < .001), and a decrease in systemic vascular resistance to 1847 +/- 175 dyne.sec/cm5 (p < .005). CONCLUSIONS: In hemorrhagic shock, the combination of MAST and hypertonic saline increases mean arterial pressure, improves cardiac output and tissue perfusion during the application of MAST, and also prolongs for > 2 hrs the short beneficial effect of hypertonic saline on mean arterial pressure.

Animals↗

PubMed1997

Isolyte S, a physiologic multielectrolyte solution, is preferable to normal saline to wash cell saver salvaged blood: conclusions from a prospective, randomized study in a canine model.

OBJECTIVES: The purpose of this study is to compare normal saline with Isolyte S as the wash solutions during high-volume cell saver autologous blood transfusion. Normal saline, the standard wash solution in cell saver autologous blood transfusion, is associated with acid-base and electrolyte derangements. Isolyte S is a physiologic, balanced multielectrolyte crystalloid solution that approximates the electrolyte content of plasma. DESIGN: Open-label, prospective, randomized study. SETTING: Research laboratory in a Department of Veterans Affairs medical center. SUBJECTS: Fourteen mongrel dogs, weighing 22 to 23 kg each. INTERVENTIONS: Fourteen mongrel dogs were prospectively randomized to receive normal saline (n = 7) or Isolyte S (n = 7). Animals were anesthetized, received heparin for anticoagulation, and underwent 18 cycles of cell saver autotransfusion. In each cycle, 125 mL of blood was arterially withdrawn, and washed with either normal saline (mEq/L) (sodium 154, chloride 154) or Isolyte S (mEq/L) (sodium 141, potassium 5, magnesium 3, chloride 98, phosphate 1, acetate 28, and gluconate 23). The washed blood was retransfused. MEASUREMENTS AND MAIN RESULTS: Acid-base and electrolyte analyses were performed throughout the study on the systemic blood of each group and compared. By the end of the study, the Isolyte S group had a normal pH and an increased bicarbonate concentration (mEq/L: normal values 24 to 32; normal saline 9.0 +/- 1.9 vs. Isolyte S 13.2 +/- 3.0 [p < .01]) and an increased magnesium concentration (mg/dL: normal values 1.6 to 2.4; normal saline 1.6 +/- 0.2 vs. Isolyte S 2.2 +/- 0.2 [p < .0001]). Additionally, the Isolyte S group had a lower chloride concentration (mEq/L: normal values 95 to 110; normal saline 130 +/- 9 vs. Isolyte S 117 +/- 7 [p < .02]) and a lower potassium concentration (mEq/L: normal values 3.5 to 5.0; normal saline 4.4 +/- 0.5 vs. Isolyte S 3.7 +/- 0.3 [p < .01]). There were no significant differences between normal saline or Isolyte S in the values of PCO2, lactic acid, sodium, total and ionized calcium, inorganic phosphorus, total protein, albumin, hemoglobin, and hematocrit. CONCLUSIONS: Fewer systemic acid-base and electrolyte derangements were observed when blood was washed with Isolyte S. Differences between the normal saline and Isolyte S groups are ascribed primarily to the constituents of the wash solution. We conclude that Isolyte S, a physiologic, balanced, multielectrolyte solution, should be considered as the wash solution in high-volume autologous cell saver blood processing and transfusion.

Animals↗

PubMed2006

Saline infusion sonography in women with abnormal uterine bleeding: an update of recent findings.

PURPOSE OF REVIEW: To inform about new developments concerning saline infusion sonography, especially in women suffering from abnormal uterine bleeding. RECENT FINDINGS: The diagnostic accuracy of saline infusion sonography has been established before the period of this review; however, recent papers support the high diagnostic accuracy and conclude saline infusion sonography is able to replace diagnostic hysteroscopy in the evaluation of the uterine cavity. The use of gel instead of saline as distension medium and the introduction of new three-dimensional inversion rendering techniques enhances the visualization of the endometrium which may improve the diagnostic accuracy of saline infusion sonography. A simple, feasible and seemingly cost-effective method of saline infusion sonography-based guided endometrial biopsy has been developed. The technique may allow saline infusion sonography based polypectomy. A classification of submucous fibroids has been proposed in order to allow more accurate, saline infusion sonography-based, preoperative selection of fibroids suitable for hysteroscopic resection. SUMMARY: The development of saline infusion sonography-based guided biopsies allows saline infusion sonography to compete with vaginoscopic operative hysteroscopy. Additional comparative trials are needed in order to finalize the decision about the proper method of the assessment of the uterine cavity.

Biopsy↗

PubMed2003

Saline contrast hysterosonography in abnormal uterine bleeding: a systematic review and meta-analysis.

OBJECTIVE: To assess the diagnostic accuracy of saline contrast hysterosonography in the evaluation of the uterine cavity in women complaining of abnormal uterine bleeding. DESIGN: A systematic review and meta-analysis of diagnostic studies that compared saline contrast hysterosonography to a gold standard diagnosis based on either hysteroscopy with or without histological sampling or to hysterectomy. SETTING: University Hospital. SAMPLE: Twenty-four studies (including 2278 procedures). METHODS: Electronic databases were searched for relevant studies and references were cross checked. Validity was assessed and data were extracted independently by two authors. Heterogeneity was calculated, studies were plotted in an ROC area and data were pooled. Subgroup analysis was performed according to the validity area. MAIN OUTCOME MEASURES: The success rate of saline contrast hysterosonography. The pooled sensitivity, specificity, likelihood ratio's and post-test probabilities of saline contrast hysterosonography on the prediction of uterine cavity abnormality. RESULTS: The largest population of homogeneous data were the studies with complete verification. In these studies, the pooled sensitivity and pooled specificity of saline contrast hysterosonography in uterine cavity evaluation were respectively 0.95 (95% CI 0.93 to 0.97) and 0.88 (95% CI 0.85 to 0.92), the likelihood ratios were respectively 8.23 (95% CI 6.2 to 11) and 0.06 (95% CI 0.04 to 0.09) and the post-test probabilities were respectively 0.91 (95% CI 0.89 to 0.94) and 0.07 (95% CI 0.04 to 0.10). The overall success rate of saline contrast hysterosonography was 93% (95% CI 92% to 94%). The feasibility of saline contrast hysterosonography in postmenopausal women (success rate 86.5%, 95% CI 83.2 to 89.8) is significantly lower (P < 0.01) compared with premenopausal women (success rate 95%, 95% CI 94% to 96%). CONCLUSION: Saline contrast hysterosonography is accurate in the evaluation of the uterine cavity in pre- and postmenopausal women suffering from abnormal uterine bleeding. The feasibility of saline contrast hysterosonography is high, although significantly better in premenopausal women compared with postmenopausal women. We conclude that saline contrast hysterosonography, in combination with an endometrium aspiration if necessary, can become the standard diagnostic procedure in women with abnormal uterine bleeding.

Contrast Media↗

PubMed1986

Effect of salinity gradients and heterotrophic microbial activity on biodegradation of nitrilotriacetic acid in laboratory simulations of the estuarine environment.

The biodegradation of nitrilotriacetic acid (NTA), a synthetic replacement detergent builder, in the estuarine environment was examined by using a laboratory estuarine simulation. Two interdependent microcosms were used; each of five vessels was equilibrated with a saline gradient between 1.30 and 17.17%, with the final vessel subsequently being increased to a maximum salinity of 31.6%. Each microcosm was seeded simultaneously with heterotrophic bacteria from both fresh and saline sources. Viable counts demonstrated the ability of each microcosm to sustain a mixed heterotrophic bacterial community throughout the range of salinities for 183 days after a stabilization period. Isolation studies demonstrated that both systems contained four bacterial species, representatives of the genera Vibrio and Flavobacterium and members of the coryneform group and the family Enterobacteriaceae. Total bacterial numbers and species diversity decreased with increased salinity. NTA was administered at low and high concentrations, one concentration to each microcosm, initially with the least amount of saline. Removal of both concentrations of NTA occurred and was attributed to biodegradation after a period of bacterial acclimatization. Subsequent dosing of NTA to vessels of higher salinity demonstrated that biodegradation was incomplete at observed mean salinities of greater than 9.18% at low influent NTA concentrations and greater than 5.08% at high influent NTA concentrations. Therefore, acclimatization was dose dependent. It was concluded that NTA acclimatization at the higher salinities ceased because of salinity stress-induced failure of NTA catabolism and not the disappearance of a particular bacterial species.

Acetates↗

PubMed1987

Effect of salinity on mercury-methylating activity of sulfate-reducing bacteria in estuarine sediments.

The biomethylation of mercury was measured in anoxic estuarine sediments that ranged in salinity from 0.03 to 2.4% with or without added molybdate, an inhibitor of sulfate reducers. Mercury methylation was inhibited by molybdate by more than 95%, regardless of sediment salinity. In the absence of inhibitor, high-salinity sediments methylated mercury at only 40% of the level observed in low-salinity sediments. In response to molybdate inhibition of sulfate reducers, methanogenesis increased up to 258% in high-salinity sediments but only up to 25% in low-salinity sediments. In contrast to an earlier low-salinity isolate, a Desulfovibrio desulfuricans strain from high-salinity sediment required 0.5 M sodium for optimal growth and mercury methylation activity. The formation of negatively charged mercuric chloride complexes at high salinity did not noticeably interfere with the methylation process. Results of these studies demonstrate that sulfate reducers are responsible for mercury methylation in anoxic estuarine sediments, regardless of the prevailing salinity.

Journal Article↗

PubMed2004

Salinity acclimation affects the somatotropic axis in rainbow trout.

In this study, we set out to examine the role of the somatotropic axis in the ion-regulation process in rainbow trout. Specifically, our objective was to examine whether plasma insulin-like growth factor-binding proteins (IGFBPs) are modulated by gradual salinity exposure. To this end, freshwater (FW)-adapted rainbow trout were subjected to gradual salinity increases, up to 66% seawater, over a period of 5 days. During this acclimation process, minimal elevations in plasma Ca2+ and Cl- were seen in the salinity-acclimated groups compared with FW controls. There were no changes in plasma Na+ levels, and only a minor transient change in plasma cortisol levels was seen with salinity exposure. The salinity challenged animals responded with elevations in plasma growth hormone (GH) and IGF-I levels and gill Na+-K+-ATPase activity. We identified IGFBPs of 21, 32, 42, and 50 kDa in size in the plasma of these animals, and they were consistently higher with salinity. Despite the overall increase in IGFBPs with salinity, transient changes in individual BPs over the 5-day period were noted in the FW and salinity-exposed fish. Specifically, the transient changes in plasma levels of the 21-, 42-, and 50-kDa IGFBPs were different between the FW and salinity groups, while the 32-kDa IGFBP showed a similar trend (increases with sampling time) in both groups. Considered together, the elevated plasma IGFBPs suggest a key role for these binding proteins in the regulation of IGF-I during salinity acclimation in salmonids.

Acclimatization↗

PubMed1994

Role of resident peritoneal cells in eosinophil migration induced by saline.

In the present study, we investigated the role of resident peritoneal cells as well as the mediators involved in the eosinophil migration induced by large volumes of physiological saline. Two consecutive intraperitoneal injections of saline given 48 h apart, induced a selective recruitment of eosinophils into the cavity. This response was not observed with phosphate-buffered saline (PBS). Saline-induced eosinophil migration may be mediated at least in part by LTB4, since the lipoxygenase inhibitors BW A4C and MK 886 prevented the response. In the presence of saline, but not of PBS, mast cells and macrophages incubated in vitro released a factor which induced eosinophil migration when injected into the peritoneal cavity of rats. This release was inhibited by BW A4C and MK 886. These results indicate the importance of mast cells and macrophages in the eosinophil migration induced by saline and suggest the participation of LTB4 in this phenomenon. An abrupt reduction in the extracellular potassium concentration at the membrane of resident cells may be responsible for the saline effects since addition of potassium ions to saline abolished the eosinophil chemotactic activity of the same as well as its ability to stimulate the release of eosinophil chemotactic factor in vitro. Dexamethasone blocked both the saline-induced eosinophil migration and the release of eosinophil chemotactic factor by mast cells and macrophages. Pretreatment of the animals with dexamethasone inhibited the eosinophil migration induced either by the supernatants of saline-stimulated mast cells and macrophages or by LTB4. These results indicate that the release of additional mediators is necessary in order to account for the final eosinophil migration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1999

Impeded alveolar-capillary gas transfer with saline infusion in heart failure.

The microvascular pulmonary endothelium barrier is critical in preventing interstitial fluid overflow and deterioration in gas diffusion. The role of endothelium in transporting small solutes in pathological conditions, such as congestive heart failure (CHF), has not been studied. Monitoring of pulmonary gas transfer during saline infusion in CHF was used to probe this issue. Carbon monoxide diffusion (DL(CO)), its membrane diffusion (D(M)) and capillary blood volume (V(C)) subcomponents, and mean right atrial (rap) and mean pulmonary wedge (wpp) pressures after saline or 5% D-glucose solution infusions were compared with baseline in 26 moderate CHF patients. Saline was also tested in 13 healthy controls. In patients, 750 mL of saline lowered DL(CO) (-8%, P<0.01 versus baseline), D(M) (-10%, P<0.01 versus baseline), aldosterone (-29%, P<0.01 versus baseline), renin (-52%, P<0.01 versus baseline), and hematocrit (-6%, P<0.05 versus baseline) and increased V(C) (20%, P<0.01 versus baseline), without changing rap and wpp. Saline at 150 mL produced qualitatively similar results regarding DL(CO) (-5%, P<0.01 versus baseline), D(M) (-7%, P<0.01 versus baseline), V(C) (9%, P<0.01 versus baseline), rap, wpp, aldosterone (-9%, P<0.05 versus baseline), and renin (-14%, P<0.05 versus baseline). Glucose solution (750 mL), on the contrary, increased DL(CO) (5%, P<0.01 versus 750 mL of saline) and D(M) (11%, P<0.01 versus 750 mL of saline) and decreased V(C) (-9, P<0.01 versus 750 mL of saline); aldosterone (-40%), renin (-41%), hematocrit (-3%), rap, and wpp behaved as they did after saline infusion. In controls, responses to both saline amounts were similar to responses in CHF patients regarding aldosterone, renin, hematocrit, rap, and wpp, whereas DL(CO), D(M), and V(C) values tended to rise. Hindrance to gas transfer (reduced DL(CO) and D(M)) with salt infusion in CHF, despite an increase in V(C) and no variations in pulmonary hydrostatic forces, indicates an upregulation in sodium transport from blood to interstitium with interstitial edema. Redistribution of blood from the lungs, facilitating interstitial fluid reabsorption, or sodium uptake from the alveolar lumen by the sodium-glucose cotransport system might underlie the improved alveolar-capillary conductance with glucose.

Aldosterone↗

PubMed2000

The effect of PVC packaging on the acidity of 0.9% saline.

Intravenous fluids in polyvinyl chloride (PVC) packaging are known to be acidic. We proposed to determine the effect of PVC packaging on the pH of 0.9% saline solutions by comparing the predicted and measured pH of 0.9% saline equilibrated with atmospheric carbon dioxide and the measured pH of commercial solutions of 0.9% saline in PVC and polypropylene packaging. Calculation of pH was made from available physical chemistry constants and data. Measurement was made of the pH of 12 samples of prepared 0.9% saline equilibrated with atmospheric carbon dioxide. Comparison with the pH of seven commercial samples of saline in PVC packaging for intravenous use was undertaken. Further comparison was made between commercial samples of 0.9% saline in PVC or polypropylene packaging. The calculated pH of 0.9% saline was 5.61 at 20 degrees C. The median pH of the prepared samples was statistically significantly less acidic than the median pH of the PVC packaged samples for intravenous use: 5.47 vs 4.60, P < 0.05. The median pH of the PVC packaged saline was also statistically significantly more acidic than the pH of the polypropylene packaged saline: 4.62 vs 5.71, P < 0.05. The acidity of the intravenous solutions of 0.9% saline packaged in PVC was much greater than expected and is only partially explained by dissolved carbon dioxide. This acidity could be a result of packaging in PVC.

Acids↗