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PubMed2001

Hypertonic saline in hydatid disease.

The objective of this study was to determine the scolicidal effects of saline in different concentrations using different exposure times and to examine whether hypertonic saline can be used to irrigate the abdomen when there is a free intraperitoneal perforation of hydatid disease. Various concentrations of saline solutions (0.09%, 3.0%, 6.5%, 10%, 15%, 20%, 25%, 30%) were added to concentrated echinococcus granulosus sediments for the following times: 1, 2, 3, 4, 5, 10, 15, 30, 45, and 60 minutes. Normal (0.09%), 3.0%, and 6.5% saline resulted in high viability ratios after 60 minutes' exposure. Complete lethality for 10%, 15%, 20%, 25%, and 30% saline occurred at the end of 75, 10, 6, 3, and 3 minutes, respectively. During the second part of the study, 20 Sprague-Dawley rats were used for abdominal saline irrigation in four groups: 30% NaCl for 3 minutes; 20% NaCl for 6 minutes; intravenous isotonic dextrose water and furosemide plus 30% NaCl irrigation for 3 minutes; the same prophylactic therapy plus 20% NaCl irrigation for 6 minutes. Sodium and chloride values rose significantly (20-30%) shortly after hypertonic saline irrigation in each group (p < 0.01). Support with isotonic dextrose and furosemide before irrigation did not have any beneficial effect on biochemical values or mortality. The 24- and 48-hour mortality rates were 70% and 90%, respectively. These studies illustrate that the scolicidal effect of hypertonic saline is limited in low concentrations, but an increase in the concentration can augment its adverse effects. Peritoneal irrigation with hypertonic saline should be avoided for intraabdominal perforated hydatid disease. Therefore, we concluded that hypertonic saline is not a good scolicidal agent to prevent recurrence of hydatid disease.

Animals↗
PubMed1998

Serial determinations of cerebral water content by magnetic resonance imaging after an infusion of hypertonic saline.

OBJECTIVE: To determine regional cerebral water content in vivo by magnetic resonance imaging (MRI) after the administration of 7.5% saline in brain-lesioned rabbits. DESIGN: Randomized, controlled, intervention trial. SETTING: University animal laboratory. SUBJECTS: Eighteen male New Zealand white rabbits, randomly assigned to one of three groups. INTERVENTIONS: The animals were anesthetized (1% halothane), intubated, and mechanically ventilated to maintain end-tidal CO2 tension between 30 and 35 mm Hg (4 and 4.7 kPa). Arterial and central venous catheters were inserted and arterial blood samples were serially obtained during the experiment. Serum osmolality was measured. A cryogenic cerebral lesion was produced by pouring liquid nitrogen for 1 min into a funnel placed on the intact skull over the right hemisphere. One group of animals received 20 mL of 7.5% saline intravenously 150 mins after the cerebral lesion was generated (7.5% saline group, n = 7). A second group of animals received the same volume of 0.9% saline intravenously (0.9% saline group, n = 7). In a third group of animals (control group, n = 4) no lesion was created and no fluid administered. MEASUREMENTS AND MAIN RESULTS: Five spin-echo T2-weighted MRIs of the brain were acquired at 90 mins (Baseline 1), 120 mins (Baseline 2), 150 mins (Infusion), 180 mins (Infusion + 30 mins), and 210 mins (Infusion + 60 mins) after the generation of the cerebral lesion. In the control group, two scans separated by a time interval of 120 mins were performed. The percent changes in signal intensity between the first and the four following scans of a coronal slice of the central region were determined. Analysis of variance and the Mann-Whitney U test were used for statistical analysis. Data are presented as mean +/- SD; p < .05 was considered significant. Serum osmolality increased significantly from 308 +/- 13 mosm/L to 349 +/- 19 mosm/L after the infusion of 20 mL of 7.5% saline, but did not change after the administration of 0.9% saline. Signal intensity in the area between the caudal edge of the core of the lesion and the basal ganglia was 9 +/- 8% higher on the injured side than in the corresponding area on the contralateral side (p < .05). Compared with Baseline 1, signal intensity at Infusion + 60 mins decreased by 26.3 +/- 13.7% in the 7.5% saline group, whereas it decreased by 10.4 +/- 8.6% in the 0.9% saline group (p < .05 between groups). Signal intensity decreased only slightly and nonsignificantly by 0.6 +/- 4.4% between the two scans in the control group. CONCLUSIONS: The administration of a 7.5% saline solution causes a prompt and substantial decrease in cerebral water content as assessed by spin-echo T2-weighted MRI. Magnetic resonance imaging offers the opportunity for repeated, noninvasive in vivo determinations of cerebral water content.

Animals↗
PubMed2003

Hypertonic saline resuscitation limits neutrophil activation after trauma-hemorrhagic shock.

There is evidence suggesting that the ischemic gut is a major source of factors that lead to neutrophil activation, and that neutrophil activation can be reduced by hypertonic saline resuscitation. Thus, we tested whether trauma-hemorrhagic shock-induced neutrophil activation can be reduced by hypertonic saline resuscitation, as well as whether hypertonic saline reduces the ability of mesenteric lymph from shocked animals to activate neutrophils. Male Sprague-Dawley rats subjected to trauma (laparotomy), plus 90 min of shock [mean arterial pressure (MAP) MAP = 30 mmHg] or sham shock were resuscitated with Ringer's lactate or 7.5% hypertonic saline at an equivalent sodium load. Whole blood samples were collected before shock as well as at 1 and 2 h after the end of the shock period for neutrophil CD11b and CD18 expression measurements. In a second set of experiments, mesenteric lymph samples collected from rats subjected to trauma plus hemorrhagic shock (T/HS) or trauma plus sham-shock (T/SS) and resuscitated with Ringer's lactate or hypertonic saline were tested for their ability to modulate PMN CD11b, CD18, or L-selectin expression, as well as prime PMN for an augmented respiratory burst. To avoid confounding results due to interspecies differences, while at the same time looking at potential human responses, both naive rat and human PMN were tested. Both CD11b and CD18 expression were increased in PMN harvested from rats subjected to T/HS and resuscitated with Ringer's lactate solution, but not in T/HS rats resuscitated with hypertonic saline. These results indicate that PMN activation is increased to a greater extent in Ringer's lactate-resuscitated than hypertonic saline-resuscitated animals. Likewise, mesenteric lymph from the T/HS rats resuscitated with Ringer's lactate increased naive rat and human PMN CD11b and CD18 expression to a greater extent than did T/HS lymph from the hypertonic saline-treated rats. Additionally, T/HS lymph from the Ringer's lactate- but not the hypertonic saline-treated rats induced PMN L-selectin shedding. Lastly, T/HS lymph from the Ringer's lactate-treated rats induced the greatest PMN respiratory burst. These results indicate that resuscitation from T/HS with hypertonic saline is associated with less PMN activation than resuscitation with Ringer's lactate, and that factors produced or released by the postischemic intestine and carried in the mesenteric lymph contribute to neutrophil activation after an episode of T/HS.

Animals↗
PubMed1994

Osmoregulation of vasopressin and thirst: comparison of 20% mannitol with 5% saline as osmotic stimulants in healthy man.

OBJECTIVE: Osmoregulation is normally studied using a 5% saline infusion. This may be deleterious in fluid overloaded patients. Twenty per cent mannitol is another osmotic stimulant. This study aimed to compare 20% mannitol infusion with 5% saline as an osmotic stimulant to thirst and vasopressin secretion in normal volunteers. DESIGN AND PATIENTS: Eight healthy volunteers studied on 2 occasions in random order. Each study involved a 2-hour infusion period of either hypertonic (5%) saline (0.06 ml/kg/h) or hypertonic (20%) mannitol (0.07 ml/kg/h). MEASUREMENTS: Plasma vasopressin (pVp), plasma sodium, plasma osmolality (pOsm), haematocrit (HCT), blood pressure, thirst, blood glucose and volume drunk at end of infusion. RESULTS: Five per cent saline infusion stimulated significantly higher levels of pOsm, pVp and thirst than 20% mannitol. Plasma sodium rose significantly during 5% saline infusion and fell during 20% mannitol infusion. HCT fell and mean arterial pressure rose in both infusions but the changes were not clinically significant. Piecewise linear regression analysis defined the overall threshold for pVp release for the two solutions as 5% saline, 292 mosm/kg and 20% mannitol, 291 mosm/kg, and the post threshold slope as 5% saline, 0.46 pmol/l pVp per mosm and 20% mannitol, 0.30 pmol/l pVp per mosm. The threshold for thirst onset was 5% saline, 291 mosm/kg and 20% mannitol, 290 mosm/kg, and the post threshold slope, 5% saline, 0.58 cm thirst per mosm and 20% mannitol, 0.28 cm thirst per mosm. The differences between the calculated osmotic thresholds and slopes post threshold for the two infusions were not significant for the pVp versus pOsm relationship. The difference between the cumulative volume drunk following the two infusions did not reach statistical significance. Mannitol caused a significant diuresis. CONCLUSIONS: Twenty per cent mannitol infusion is an effective osmotic stimulant to thirst and vasopressin release in normal individuals, but is less potent than 5% saline infusion.

Adult↗
PubMed2006

Selective inhibition of polymorphonuclear neutrophils by resuscitative concentration of hypertonic saline.

OBJECTIVES: This study investigated the effect of hypertonic saline on the role of polymorphonuclear neutrophils (PMNs) in the inflammatory response and the effect of hypertonic saline infused at different phases in relation to an inflammatory stimulus. MATERIALS AND METHODS: PMNs were isolated from peripheral blood of healthy volunteers (Boyum's method) and cultured in three different media ([Na+] = 140 mmol/l, 180 mmol/l, and 200 mmol/l). PMNs were then stimulated with fMLP (N-formyl-methionyl-leucyl-phenylalanine) and H2O2 synthesis was quantified by flow cytometry at 5, 30, 60, 120, and 180 minutes. PMNs were treated with hypertonic saline before, simultaneously with, and after fMLP stimulation, and H2O2 synthesis quantified again. RESULTS: H2O2 synthesis was two or three times higher in fMLP stimulated than in non-stimulated PMNs, and it reached maximum level at 120 minutes. In the absence of fMLP stimulation, there was no significant difference between control and hypertonic saline with regard to activity of H2O2 synthesis. In the presence of fMLP stimulation, H2O2 synthesis significantly decreased in PMNs treated with hypertonic saline. There was no significant difference between the two hypertonic saline solutions ([Na+] = 180 mmol/l and 200 mmol/l) with regard to H2O2 synthesis. However, H2O2 synthesis decreased in PMNs treated with hypertonic saline before and simultaneously with fMLP stimulation, but was not significantly decreased in the cells treated with hypertonic saline after fMLP stimulation. CONCLUSIONS: Hypertonic saline appears to decrease H2O2 in stimulated neutrophils. This may be a further beneficial role of hypertonic saline when used clinically as an early resuscitation fluid.

Analysis of Variance↗
PubMed2001

Hypertonic saline alters ion transport across the human airway epithelium.

Aerosolized hypertonic saline is currently being investigated as a new agent for the treatment of impaired mucociliary clearance which occurs in many respiratory diseases. Mannitol aerosols, in particular dry powder inhalers, have been proposed as an alternative treatment to saline, offering the same osmotic load with other benefits. However, the effects of these hypertonic aerosols on airway epithelial ion transport processes have not been tested in human subjects in vivo. This report examines the effect of these solutions on airway ion transport using the nasal potential difference (PD) technique. Seven healthy nonsmoking adult volunteers were studied. On different days, a dose-response curve was constructed for the saline added to Krebs N-[2-hydroxyethyl] piperazine-N'-[2-ethanesulphonic acid] (HEPES) diluent. The reversibility of this saline effect was measured, and the response to additional saline (500 mM) and mannitol (1 M) compared. Hypertonic saline decreased nasal PD in a dose-related manner, with mean (SEM) decreases in PD (less negative) of 6.6 (1.5), 7.6 (1.6), 10.0 (2.0), 13.1 (2.9) and 14.8 (3.2) mV (n =4) for addition of 150 mM, 250 mM, 500 mM, 1,200 mM and 2,000 mM NaCl to the Krebs HEPES diluent, respectively. The effect of hypertonic saline was fully reversible with washout for 3 min (presaline 15.9 (0.5) mV, postwashout 15.8 (1.1) mV, (n=4)). The hypertonic saline response was rapid in onset, sustained for at least 4 min, and decreased PD from 13.7 (1.7) mV to 5.1 (1.3) mV (n = 7, p < 0.001). In contrast, addition of mannitol to the perfusate did not significantly alter nasal PD, with a nonsignificant trend towards an increase (more negative) in the PD, (premannitol 13.9 (1.6) mV, postmannitol 15.3 (2.0) mV, n=7). As the osmotic stimulus of the 1 M mannitol is similar to that of the 500 mM sodium chloride, the divergent nasal potential difference responses suggest that the response to the saline was specific to the sodium chloride itself and not the simultaneous change in osmolarity. This demonstrates that the human airway epithelium in vivo can respond to topical hypertonic saline independent of the altered osmolarity.

Administration, Intranasal↗
PubMed2004

Hypotonic vs isotonic saline solutions for intravenous fluid management of acute infections.

BACKGROUND: Hypotonic saline is commonly used as maintenance fluid in the management of acute infections. In recent years use of a hypotonic saline has been associated with adverse outcomes. To reduce the rates of adverse outcomes, use of isotonic saline as maintenance fluid has been suggested. OBJECTIVES: To asses adverse events and benefits associated with infusion of hypotonic saline compared to isotonic saline solutions in the management of acute infections. SEARCH STRATEGY: We searched MEDLINE, EMBASE, The Cochrane Controlled Trials Register, current controlled trials and the Specialised register of the Injuries Group. SELECTION CRITERIA: Randomised trials comparing hypotonic saline to isotonic saline in the management of acute infections. DATA COLLECTION AND ANALYSIS: Three reviewers independently evaluated all potentially relevant articles, examined each study for possible inclusion and assessed the methodology quality using the Cochrane guidelines. MAIN RESULTS: No trials met our inclusion criteria. REVIEWERS' CONCLUSIONS: We found no randomised controlled evidence to show that use of isotonic saline as a maintenance fluid instead of a hypotonic saline will lead to an improvement in outcomes. Randomised trials with adequate design and sample sizes are needed to evaluate the possible advantages and risks of using isotonic saline as maintenance fluid.

Acute Disease↗
PubMed2005

Branchial osmoregulatory response to salinity in the gilthead sea bream, Sparus auratus.

The branchial osmoregulatory response of gilthead sea bream (Sparus auratus L.) to short-term (2-192 hr) and long-term (2 weeks) exposure to different environmental salinities (5 per thousand, 15 per thousand, 25 per thousand, 38 per thousand and 60 per thousand) was investigated. A "U-shaped" relationship was observed between environmental salinity and gill Na+,K+ -ATPase activity in both long- and short-term exposure to altered salinity, with the increase in activity occurring between 24 and 96 hr after the onset of exposure. Plasma osmolality and plasma ions (sodium, chloride, calcium and potassium) showed a tendency to increase in parallel with salinity. These variables only differed significantly (P<0.05) in fish adapted to 60 per thousand salinity with respect to fish adapted to full-strength sea-water (SW). Plasma glucose remained unchanged whereas plasma lactate was elevated at 5 per thousand and 60 per thousand. Muscle water content (MWC) was significantly lower in fish adapted to 60 per thousand. Chloride cells (CC) were only present on the surface of the gill filaments and absent from the secondary lamellae. CC distribution was not altered by external salinity. However, the number and size of CC were significantly increased at salinity extremes (5 per thousand and 60 per thousand), whereas fish exposed to intermediate salinities (15 per thousand and 25 per thousand) had fewer and smaller cells. Furthermore, the CC of fish exposed to diluted SW became rounder whereas they were more elongated in fish in full-strength and hypersaline SW. This is consistent with previous reports indicating the existence of two CC types in euryhaline fish. At likely environmental salinities, gilthead sea bream show minor changes in plasma variables and the effective regulation of gill Na+,K+ -ATPase. However, at very low salinities both haemodilution and up-regulation of gill Na+,K+ -ATPase predict a poor adaptation most likely related to deficiency or absence of specific components of the CC important for ion xuptake.

Analysis of Variance↗
PubMed2000

Salinity discrimination in harbour seals: a sensory basis for spatial orientation in the marine environment?

Salinity variations can be considered as a potential source of information for orientation in the marine environment. To use this kind of environmental information marine animals must be able to detect these salinity differences. Therefore we determined salinity-difference thresholds of two harbour seals for the discrimination of seawater solutions as a function of the salinity level (15-35@1000) and compared them with the thresholds of human subjects. Whereas in humans thresholds increased with increasing salinity level, thresholds of seals decreased with increasing salinity level. Both seals achieved best sensitivity at 30/1000 salinity, where they detected a salinity difference < or = 4%. These data indicate that the ability of seals to detect salinity differences of seawater is well tuned to the natural occurrence of this environmental information. Their high gustatory resolving power for differences in seawater salinity is suggested to meet the basic requirements for chemosensory orientation of seals in the marine habitat.

Animals↗
PubMed1998

Perfluorocarbon broncho-alveolar lavage and liquid ventilation versus saline broncho-alveolar lavage in adult guinea pig experimental model of meconium inhalation.

OBJECTIVE: This study compares perfluorocarbon broncho-alveolar lavage (PFC-BAL) with isotonic saline broncho-alveolar lavage (saline-BAL) in an experimental model of meconium aspiration in adult guinea pigs. DESIGN: Prospective controlled experimental study. PATIENTS AND METHODS: Ten male guinea pigs were given 1 ml of human meconium, diluted to 10% in isotonic saline, via tracheostomy and then artificially ventilated. After stabilization, five animals (control group) underwent BAL with 10 ml/ kg isotonic saline solution. After bronchial suctioning, a further BAL with 2 ml/kg saline was performed. The other five animals (study group) underwent BAL with 100 ml/kg of PFC (RIMAR 101). Bronchosuction was effected at 5 min and then a BAL with PFC 2 ml/kg was performed. Both groups received conventional mechanical ventilation during the lavage procedures. Within 20 min all the saline-BAL treated animals died, whereas the PFC-BAL treated animals survived and were then treated with total liquid ventilation (TLV) by gravity. MEASUREMENTS AND RESULTS: After meconium inhalation in both groups, a large alveolar-arterial oxygen difference, hypercarbia, severe acidosis and tachycardia were noticed. In PFC treated animals, an improvement in blood gases was noted and acid-base balance remained stable compared to saline-BAL treated animals. No haemodynamic change was observed during or after PFC-BAL, while during saline-BAL there was evidence of bradycardia, hypotension and respiratory failure, which led to the death of the animals. The histological lung sections in the PFC-BAL group showed evidence of normal alveolar expansion with a minimal presence of meconium debris in the small bronchioles. In saline-BAL treated animals, the lung structure appeared severely compromised with the presence of meconium in bronchioles and alveoli, intra-alveolar oedema and haemorrhagic areas. CONCLUSIONS: This study confirms the detrimental effects of meconium aspiration and the impairment of lung function following saline-BAL. By contrast, PFC-BAL and TLV by gravity seemed to prevent absorption of meconium, facilitate its removal, improve gas exchange and reduce lung barotrauma.

Acute Disease↗
PubMed2001

Accumulation of 109Cd by second-generation chironominae propagated from wild populations sampled from low-, mid-, and high-saline environments.

Our objective was to determine if second-generation (F2) chironomids propagated from adults of larvae sampled from low-, mid-, and high-saline environments differed in their ability to accumulate cadmium from their environment. Second-generation chironomids cultured from wild populations were exposed to 109Cd at 0, 0.7, and 4.3 ppt salinity for 10 days, at which time survival and amounts of 109Cd accumulated were determined. Cultures included two of Chironomus tentans from a freshwater lake (lake 78; 0 ppt), and the euryhaline C. athalassicus from a mid- (lake 71; 0.7 ppt) and high (lake 56; 4.3 ppt)-saline environment. A laboratory-reared culture of C. tentans was included as a positive control. Species-dependent accumulation of 109Cd occurred; second-generation C. athalassicus cultured from the high-salinity lake survived in the three salinities and accumulated significantly greater amounts of the radiotracer at 0 and 0.7 ppt compared to the second-generation freshwater species, C. tentans. Second-generation C. athalassicus cultured from lake 71 also survived all salinities with 109Cd accumulation tending to be greater than the freshwater species at the mid-salinity range. In contrast, the freshwater species cultured from lake 78 as well as the laboratory-reared culture did not survive the highest salinity of 4.3 ppt and accumulated less 109Cd compared to the species from the high-saline environments. Species-dependent differences in metal accumulation need to be considered in studies that assess metal concentrations in aquatic organisms across an environmental gradient, such as salinity.

Animals↗
PubMed2002

Interaction of normal saline solution with ultrasound contrast medium: significant implication for sonographic diagnosis of vesicoureteral reflux.

The sonographic diagnosis of vesicoureteral reflux with intravesical administration of ultrasound contrast media is on the rise. In few cases did we encounter rapid dissolution of microbubbles in the bladder filled with normal saline. The aim of this study was to find out whether there is any interaction between normal saline and ultrasound contrast media and, if so, to elucidate the cause for the interaction. In an in vitro experimental setup the mixtures of various normal saline solutions and a galactose-based ultrasound contrast medium (Levovist) were scanned under pre-defined parameters. The duration of contrast was determined. Oxygen concentration of the solutions was measured (pO(2) and O(2) mg/l). The US contrast medium had significantly longer contrast duration when mixed with normal saline from plastic containers rather than glass containers. The contrast duration difference was even more between normal saline from containers sealed under vacuum and those not sealed under vacuum: 0.7 and 12 min, respectively. The oxygen concentration in normal saline from vacuum-sealed containers is one-third or less that from non-vacuum-sealed containers. The high concentration of dissolved oxygen in the normal saline seems to prevent the diffusion of air from the microbubbles into the solution and thus their collapse. Desaturated normal saline has detrimental effect on microbubbles of the galactose-based US contrast medium. For the purpose of filling the bladder during contrast-enhanced voiding urosonography only normal saline solution from non-vacuum-sealed containers should be used. For practical purposes, normal saline from plastic containers is safest.

Administration, Intravesical↗
PubMed2000

Reinforcement of spinal anesthesia by epidural injection of saline: a comparison of hyperbaric and isobaric tetracaine.

PURPOSE: An epidural injection of saline was reported to extend spinal anesthesia because of a volume effect. The aim of this study was to evaluate the influence of the baricity of spinal local anesthetics upon the extension of spinal anesthesia by epidural injection of saline. METHODS: Forty patients undergoing elective lower-limb surgery were randomly allocated to four groups of 10 patients each. Group A received no epidural injection after the spinal administration of hyperbaric tetracaine (dissolved in 10% glucose). Group B received an epidural injection of 8 ml of physiological saline 20 min after spinal hyperbaric tetracaine. Group C received no epidural injection after spinal isobaric tetracaine (dissolved in physiological saline). Group D received an epidural injection of 8 ml of saline 20 min after spinal isobaric tetracaine. The level of analgesia was examined by the pinprick method at 5-min intervals. RESULTS: The levels of analgesia 20 min after spinal anesthesia were significantly higher in hyperbaric groups than in isobaric groups [T5 (T2-L2) vs. T7 (T3-12)]. After epidural injection of saline, the levels of analgesia in groups B and D were significantly higher than in groups A and C. The segmental increases after epidural saline injection were 2 (0-3) in group B and 2 (1-7) in group D. Sensation in the sacral area remained 20 min after spinal block in one patient in group D; however, it disappeared after epidural saline injection. CONCLUSION: In this study, 8 ml of epidural saline extended spinal analgesia. However, there was no difference between the augmenting effect in isobaric and hyperbaric spinal anesthesia. We conclude that the reinforcement of spinal anesthesia by epidural injection of saline is not affected by the baricity of the spinal anesthetic solution used.

Clinical Trial↗
PubMed1993

Strain differences in consumption of saline solutions by mice.

Intake of saline (NaCl) solutions and water by males of two inbred strains of mice [C57BL/6J (C57) and 129/J] were examined using 48-h, two-bottle preference tests. There was a large strain difference in saline intake: at moderate concentrations (0.075-0.150 M) C57 mice tended to reject saline relative to water, whereas 129/J mice preferred it. Both strains of mice increased their intake of saline following lasix-induced sodium depletion and the preference exhibited by 129/J mice for 0.15 M NaCl was eliminated following LiCl toxicosis. The rejection of moderate concentrations of saline by C57 was shown to be due, in part at least, to prior exposure to iso- or hypertonic saline solutions: C57 mice that had no prior exposure to saline exhibited a greater intake of saline than C57 mice previously exposed to 0.30 M NaCl. Saline preferences of the 129/J mice were not affected by prior exposure to 0.30 M NaCl. Thus, the strain difference in mouse salt preference is due in part to postingestional consequences of saline consumption in C57 but not 129/J mice.

Animals↗
PubMed2004

Sensitivity to cadmium along a salinity gradient in populations of the periwinkle, Littorina littorea, using time-to-death analysis.

In this study, we assessed the combined effect of Cd concentration and salinity, on Cd uptake and mortality rate of Littorina littorea, collected along a salinity and pollution gradient in the Western Scheldt estuary (The Netherlands). Animals kept at their field salinity levels were exposed to three Cd concentrations (i.e. 10, 40 and 320 microM), while animals kept in 10 microM of Cd were subjected to five salinity treatments (i.e. 15, 20, 25, 30 and 35 per thousand). Mortality was recorded every 24h and Cd body burdens were measured with ICP-AES. Time-to-death data were analysed via Cox proportional hazard models, including the co-variates "site-Cd treatment" in the Cd experiment and "site-salinity treatment" in the salinity experiment. "Cd-treatment" and "field-salinity" affected mortality rates significantly in the Cd experiment, such that the mortality risk increased by 2.3 times when salinity was lowered from 35 to 15 per thousand, while it decreased by 19.7 times when Cd dropped from 320 to 10 microM. "Site" did not significantly affect the mortality risk in the salinity experiment but affected time-to-death via its interaction with the "salinity-treatment". Generally, mortality did not occur at a given threshold Cd tissue level, but changed over time and treatments, in function of the site. The results demonstrate the importance of the animals' environmental history and illustrate the usefulness of time-to-death analyses in ecotoxicological experiments.

Animals↗
PubMed2005

Assessment of risk to aquatic biota from elevated salinity -- a case study from the Hunter River, Australia.

An ecological risk assessment was performed on salinity levels of the Hunter River and its tributaries to respond to concerns that high salinity may be damaging aquatic ecosystems. Probabilistic techniques were used to assess likelihood and consequence, and hence the risk to aquatic biota from salinity. Continuous electrical conductivity distributions were used to describe the likelihood that high salinity would occur (exposure dataset) and toxicity values were compiled from the limited literature sources available to describe the consequence of high salinity (effects dataset). The assessment was preliminary in the sense that it modelled risk on the basis of existing data and did not undertake site-specific toxicity testing. Some sections of the Hunter River catchment have geologies that are saline because of their marine origins. Catchment development has increased the liberation rates of salts into surface-waters. Such modifying activities include coal-mining, power generation and land clearing. The aquatic biota of tributaries had a greater risk of impairment from high salinity than that of the Hunter River. High salinities in the tributaries were attributed to the combined factors of naturally saline geologies, increased liberation of salts due to modification of the landscape, and reduced dilution by flushing flows. A salinity guideline trigger value of 1100 mg L(-1) was recommended.

Animals↗
PubMed2006

Partial substitution of NO(3)(-) by NH(4)(+) fertilization increases ammonium assimilating enzyme activities and reduces the deleterious effects of salinity on the growth of barley.

Productivity of cereal crops is restricted in saline soils but may be improved by nitrogen nutrition. In this study, the effect of ionic nitrogen form on growth, mineral content, protein content and ammonium assimilation enzyme activities of barley (Hordeum vulgare cv. Alexis L.) irrigated with saline water, was determined. Leaf and tiller number as well as plant fresh and dry weights declined under salinity (120 mM NaCl). In non-saline conditions, growth parameters were increased by application of NH(4)(+)/NO(3)(-) (25:75) compared to NO(3)(-) alone. Under saline conditions, application of NH(4)(+)/NO(3)(-) led to a reduction of the detrimental effects of salt on growth. Differences in growth between the two nitrogen regimes were not due to differences in photosynthesis. The NH(4)(+)/NO(3)(-) regime led to an increase in total N in control and saline treatments, but did not cause a large decrease in plant Na(+) content under salinity. Activities of GS (EC 6.3.1.2), GOGAT (EC 1.4.1.14), PEPC (EC 4.1.1.31) and AAT (EC 2.6.1.1) increased with salinity in roots, whereas there was decreased activity of the alternative ammonium assimilation enzyme GDH (EC 1.4.1.2). The most striking effect of nitrogen regime was observed on GDH whose salinity-induced decrease in activity was reduced from 34% with NO(3)(-) alone to only 14% with the mixed regime. The results suggest that the detrimental effects of salinity can be reduced by partial substitution of NO(3)(-) with NH(4)(+) and that this is due to the lower energy cost of N assimilation with NH(4)(+) as opposed to NO(3)(-) nutrition.

Adaptation, Physiological↗
PubMed2001

Transvaginal sonography, saline contrast sonohysterography and hysteroscopy for the investigation of women with postmenopausal bleeding and endometrium > 5 mm.

OBJECTIVES: To determine the ability of transvaginal ultrasound, with or without saline infusion, to detect focally growing lesions in the uterine cavity in women with postmenopausal bleeding and endometrium > 5 mm, and to determine the accuracy of conventional ultrasound, saline contrast sonohysterography and diagnostic hysteroscopy under general anesthesia to diagnose endometrial polyps, submucous myomas and uterine malignancy. DESIGN: In a prospective study, 105 women with postmenopausal bleeding and endometrium > 5 mm underwent conventional ultrasound examination and saline contrast sonohysterography. Diagnostic and operative hysteroscopy under general anesthesia was then performed. The presence of focally growing lesions and the type of lesion (endometrial polyp, submucous myoma, malignancy or unclear focal lesion) were noted at ultrasound examination and at hysteroscopy. RESULTS: There was almost perfect agreement (96%) between saline contrast sonohysterography and hysteroscopy in the diagnosis of focally growing lesions. Saline contrast sonohysterography and hysteroscopy both had a sensitivity of approximately 80% with regard to diagnosing endometrial polyps (false-positive rates of 24% and 6%, respectively), whereas conventional ultrasound missed half of the polyps (sensitivity, 49%; false-positive rate, 19%). Hysteroscopy was superior to both saline contrast sonohysterography and conventional ultrasound with regard to discriminating between benign and malignant lesions (sensitivity, 84%, 44%, and 60%; false-positive rate, 15%, 6% and 10%, respectively). The risk of malignancy was increased seven-fold (odds ratio, 7.3; 95% confidence interval, 1.9-27.8) in women with distension difficulties at saline contrast sonohysterography, and two thirds of the women with a poorly distensible uterine cavity had a malignant diagnosis. CONCLUSION: Saline contrast sonohysterography is as good as hysteroscopy at detecting focally growing lesions in the uterine cavity in women with postmenopausal bleeding. However, neither hysteroscopy nor saline contrast sonohysterography can reliably discriminate between benign and malignant focal lesions. Distension difficulties at saline contrast sonohysterography should raise a suspicion of malignancy.

Adult↗