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PubMed1995

Analysis of central opioid receptor subtype antagonism of hypotonic and hypertonic saline intake in water-deprived rats.

Intake of either hypotonic or hypertonic saline solutions is modulated in part by the endogenous opioid system. Morphine and selective mu and delta opioid agonists increase saline intake, while general opioid antagonists reduce saline intake in rats. The present study evaluated whether intracerebroventricular administration of general (naltrexone) and selective mu (beta-funaltrexamine, 5-20 micrograms), mu, (naloxonazine, 50 micrograms), kappa (nor-binaltorphamine, 5-20 micrograms), delta (naltrindole, 20 micrograms), or delta 1 (DALCE, 40 micrograms) opioid receptor subtype antagonists altered water intake and either hypotonic (0.6%) or hypertonic (1.7%) saline intake in water-deprived (24 h) rats over a 3-h time course in a two-bottle choice test. Whereas peripheral naltrexone (0.5-2.5 mg/kg) significantly reduced water intake and hypertonic saline intake, central naltrexone (1-50 micrograms) significantly reduced water intake and hypotonic saline intake. Water intake was significantly reduced following mu and kappa receptor antagonism, but not following mu 1, delta, or delta 1 receptor antagonism. In contrast, neither hypotonic nor hypertonic saline intake was significantly altered by any selective antagonist. These data are discussed in terms of opioid receptor subtype control over saline intake relative to the animal's hydrational state and the roles of palatability and/or salt appetite.

Animals↗

PubMed2000

Extra-amniotic saline, laminaria, or prostaglandin E(2) gel for labor induction with unfavorable cervix: a randomized controlled trial.

OBJECTIVE: To determine which of three methods of cervical ripening resulted in the lowest cesarean rate in women with unfavorable cervices and indications for labor induction. METHODS: Consenting women with singleton gestations, vertex presentations, and unfavorable cervices (dilatation under 2 cm and effacement under 75%) were randomly assigned to laminaria and standard intravenous oxytocin, serial doses of intracervical prostaglandin (PG) E(2) gel (Prepidil, Pharmacia & Upjohn, Inc., Kalamazoo, MI) 0.5 microg every 6 hours for two doses followed by oxytocin if indicated, or extra-amniotic saline infusion and oxytocin. RESULTS: An interim analysis after recruitment of 321 subjects, 67% of the planned sample, found similar cesarean rates for the three groups (laminaria 36%; PGE(2) gel 33%; saline infusion 29%; P =.59); however, the mean randomization-to-delivery interval was significantly longer in the PGE(2) group. Stochastic curtailment, as part of the interim analysis, indicated a low likelihood of achieving a statistically significant difference in cesarean rates between PGE(2) gel and the other two groups. Therefore, we completed the study with saline infusion and laminaria. The saline infusion and laminaria groups had similar preinduction characteristics. The cesarean rates were similar (saline infusion 25.4% versus laminaria 30.3%; P =.32), but the mean interval from randomization to delivery was shorter in the saline infusion group (18.0 versus 21.5 hours, P =.002). There were no significant differences in selected maternal and neonatal morbidities. CONCLUSION: Cervical ripening with extra-amniotic saline infusion, PGE(2), or laminaria resulted in comparable cesarean rates in women with an unfavorable cervix and indications for labor induction. Extra-amniotic saline infusion had the shortest randomization-to-delivery interval without increasing maternal or neonatal morbidity.

Adult↗

PubMed1994

Effect of atrial natriuretic hormone on hypertonic saline-induced suppression of the renin-aldosterone system.

To evaluate the effect of physiologic doses of atrial natriuretic hormone (ANH) on hypertonic saline-induced renin-aldosterone system suppression, nine healthy subjects were studied three times: 1) on a low-salt (LS) diet with a 2 h placebo infusion; 2) on LS with 2 h infusion of human Ser-Tyr28 ANH (0.6 pmol/kg/min)(LS+ANH); and 3) on a high-salt (HS) diet with a 2 h placebo infusion. On each study day during the second hour of infusion, subjects also received 3% saline (0.1 mL/kg/min) infusion. Data from eight subjects were used for analysis because of a sampling error in one subject. During ANH infusion, plasma ANH levels increased about twofold and reached levels similar to ANH levels on HS. Serum sodium increased by 3-4 mEq/L, and serum osmolality increased by 7-8 mOsm/L during 3% saline infusion on all study days. ANH levels remained stable during 3% saline infusion. During the first hour of ANH infusion, plasma renin activity (PRA) decreased by about 24% and aldosterone levels by about 27%. Hypertonic saline caused further suppression of PRA and aldosterone. The extent of the suppression was similar under each condition, and the levels at the end of hypertonic saline infusion reached about 60% of the levels at the beginning of the saline infusion. We conclude that low-dose ANH infusion does not seem to have any major influence on PRA and aldosterone response to hypertonic saline.

Adult↗

PubMed1993

The determinants of airway hyperresponsiveness to hypertonic saline in atopic asthma in vivo. Relationship with sub-populations of peripheral blood leucocytes.

In patients with asthma there is only a weak relationship between airway responsiveness to hypertonic saline and methacholine. We tested the hypothesis that airway responsiveness to hypertonic saline in asthma is related to the presence and activity of inflammatory cells in the peripheral blood. Nineteen atopic asthmatic adults (19-28 yr; PC20 0.06-12.4 mg/ml), not receiving steroid treatment, entered a metacholine and hypertonic saline period in random order. Dose-response curves to doubling doses of inhaled methacholine (0.03-256 mg/ml) or hypertonic saline (0.9-14.4% NaCl) were obtained twice in each period, 7 days apart. The response was measured by FEV1. Methacholine responsiveness was measured by PC20 METH of FEV1 and responsiveness to hypertonic saline was expressed as the percentage fall in FEV1 after 14.4% NaCl (HYP14.4%). Peripheral blood was collected before the second challenge test of each period. Apart from leucocyte counts and serum eosinophilic cationic protein (ECP) level, sub-sets of lymphocytes (CD4+/CD3+, CD8+/CD3+, CD25+/CD4+ and VLA-1+/CD4+) were determined using flow cytometry. HYP14.4% was positively correlated to basophil, eosinophil and monocyte counts (r = 0.64, 0.54 and 0.44, respectively; P < 0.05). The basophil count remained positively related to HYP14.4% when PC20METH or FEV1%pred were entered in multiple linear regression analyses (r = 0.66 and 0.75, respectively; P < 0.05). There were no significant relationships between HYP14.4% or PC20METH on one side and ECP level or T-lymphocyte subsets on the other (P > 0.05). We conclude that airway responsiveness to hypertonic saline is positively related to the number of peripheral blood basophils, eosinophils and monocytes. Basophil count is an independent correlate of responsiveness to hypertonic saline, after correction for methacholine responsiveness and baseline lung function. This fits in with active involvement of basophils in airway narrowing to hypertonic saline in vivo.

Adult↗

PubMed1989

Role of histamine release in hypertonic saline induced bronchoconstriction.

In a study designed to determine the protective effect of the specific histamine H1 antagonist terfenadine on hypertonic saline induced bronchoconstriction, 10 asthmatic subjects underwent hypertonic saline challenge (3.6%) after premedication with placebo or terfenadine (120 mg) 12 and two hours before the challenge. Hypertonic saline was administered in a dose dependent manner and the response determined as the dose of hypertonic saline that induced a 20% fall in FEV1 (PD20 FEV1). FEV1 was on average 11% greater with terfenadine than with placebo given before the challenge with hypertonic saline. PD20 FEV1 was attenuated by a mean of 2.5 fold after terfenadine (geometric mean PD20 FEV1 was 22 litres after placebo and 56 l after terfenadine). There was substantial intersubject variation in the inhibitory effect of terfenadine on hypertonic saline induced bronchoconstriction: the ratio of the PD20 hypertonic saline after terfenadine to that after placebo ranged from 0.9 to 10.0. Terfenadine inhibited histamine induced bronchoconstriction in the eight subjects in whom it was tested, by 13 to 160 fold compared with placebo in four subjects and by greater than 2 to greater than 9 fold in the four who showed no response to the highest dose of histamine given (16 mg/ml). These results suggest that histamine release has a role in hypertonic saline induced bronchoconstriction in some individuals; other mediators or mechanisms may have a more prominent role in others.

Adult↗

PubMed1981

Hypo- and hyperosmolal saline and raffinose on kidney cortical cell volume at 37 degrees C.

Cell water content was measured in respiring rat renal cortical slices incubated in hypo- and hyperosmolal saline with and without raffinose and ouabain for 60 min at 37 degrees C. At 60 min, hyposmolal saline (228 mosmol/kg H2O) caused a 16% swelling of cells, whereas addition of 73 mM raffinose (299 mosmol/kg H2O) caused a 33% shrinkage. Physiological saline plus raffinose (364 mosmol/kg H2O) caused a 28% cell shrinkage, whereas addition of saline (385 mosmol/kg H2O) produced only a 10% decrease in cell volume. The effects of raffinose were reversible. At physiological Na concentrations, osmole for osmole raffinose was 4 times as effective in shrinking cells as saline, but only 2 times as effective at Na of 112 mM. Osmotic effectiveness of saline changed, that of raffinose did not. Ouabain caused no changes in cell volume and did not prevent the effect of raffinose. In conclusion, there is no volume regulation to nonelectrolyte solutes and only partial volume regulation to saline, and this is due to differential osmotic effects of these solutes, that of saline decreasing from low to high Na.

Animals↗

PubMed1994

Airway effects of local challenge with hypertonic saline in exercise-induced asthma.

Hypertonicity of airway lining fluid has been suggested as the stimulus for bronchoconstriction in exercise-induced asthma. We explored the airway effects of delivering a direct hypertonic stimulus to asthmatic airways via a fiberoptic bronchoscope, comparing hypertonic saline challenge by direct instillation with local aerosol delivery. A group of 18 asthmatic subjects responsive to inhaled hypertonic saline with a history of EIA were studied; the first 9 subjects received local challenge with hypertonic saline by direct instillation, and the next 9 subjects were challenged by local aerosol delivery. A control challenge with isotonic saline by either instillation or aerosol was performed at a same bronchoscopy. Local challenge with hypertonic saline by aerosol delivery was found to be more effective in inducing local bronchoconstriction (8 of 9 subjects) than instillation (2 of 6 subjects). Paired BAL fluid samples and bronchial biopsies were obtained in total of 11 and 9 subjects, respectively. Local challenge with hypertonic saline either by instillation or aerosol produced no significant change in histamine, tryptase, or PGD2 levels in BAL fluid or mast cell numbers and degranulation in bronchial biopsies. A significant correlation was observed between histamine levels in BAL fluid and airway responsiveness to inhaled hypertonic saline (rs = -0.59, p < 0.05). Bronchial biopsies showed evidence of extensive epithelial damage; however, this was not related to airway responsiveness to inhaled hypertonic saline.

Adolescent↗

PubMed1994

Hypertonic saline challenge in an epidemiologic survey of asthma in children.

To evaluate sensitivity and specificity of a 4.5% hypertonic saline challenge for a diagnosis of asthma, we studied 393 schoolchildren (13 to 15 yr of age) with "current wheeze," "former wheeze," and without history of wheeze in a community-based, cross-sectional survey. These children were selected from 2.836 schoolchildren in 26 schools in greater Melbourne, Australia who completed a self-administered questionnaire on respiratory symptoms, allergic rhinitis, and eczema. Three hundred eighty-two of 393 children successfully completed a 4.5% hypertonic saline challenge with increasing inhalation periods, and 365 of 393 performed a 6-min standardized, free running exercise challenge. The prevalence of bronchial hyperresponsiveness to hypertonic saline was 20.4%. Sensitivity and specificity for the hypertonic saline challenge to identify children with "current wheeze" were 47% and 92% respectively and for the exercise challenge, 46% and 88%. The agreement of response to hypertonic saline and to exercise was only moderate (kappa = 0.43). Factors associated with increased response to hypertonic saline in a multivariate logistic regression model were a history of "current wheeze," hay fever, response to the exercise challenge, female sex, and a lower baseline predicted FEV1. These results suggest that a 4.5% hypertonic saline challenge shows sensitivity and specificity similar to a standardized exercise challenge and pharmacologic challenges and a higher sensitivity than cold air hyperventilation and distilled water to identify asthma in children in a field study. Measurement of responsiveness to hypertonic saline may be of value as an objective marker of asthma to compare prevalence studies of bronchial hyperresponsiveness and of asthma over time and between countries.

Adolescent↗

PubMed1996

Influence of hypertonic saline solution infusion on defibrillation efficacy.

Hypertonic saline solution may enhance cardiac conduction via the fast inward sodium channel and alter transmembrane Ca+2 conductance via the sodium-calcium exchanger. Evidence suggests that both Ca+2 conductance and myocardial conduction velocity may affect ventricular defibrillation. Since hypertonic saline solution solutions (ie, sodium bicarbonate) may be administered to patients who have conditions that often require ventricular defibrillation (ie, cardiac arrest or hypovolemic shock), we studied the effect of hypertonic saline solution on the defibrillation threshold (DFT) in 16 pentobarbital-anesthetized domestic farm swine (20 to 30 kg). Defibrillation was performed using two interfaced epicardial electrode patches. DFTs were determined at baseline and during treatment phase. Pigs were randomly assigned to treatment consisting of either hypertonic saline solution (6 mmol/kg load, 2.0 to 3.0 mmol/kg infusion) to maintain serum sodium concentrations 10 to 15 mmol/L above baseline or control (D5W given in equal volume). DFT values (joules) that predicted 50% success were modeled from a best-fit histogram. Hypertonic saline solution did not change DFT values from baseline values (10.2 +/- 4.3 vs 10.8 +/- 7.0, respectively). Likewise, placebo (D5W) did not change DFT values from baseline values (10.1 +/- 4.5 vs 11.3 +/- 4.3). During treatment phase, DFT values were 99 +/- 28% of baseline values in the hypertonic saline solution group and 116 +/- 23% of baseline values in the D5W groups (p = 0.21). The administration of hypertonic saline solution also did not affect ventricular conduction velocity, right ventricular action potential duration, or right ventricular effective refractory period. These data indicate that hypertonic saline solution does not appreciably affect defibrillation efficacy or electrical treatment of ventricular fibrillation.

Animals↗

PubMed2006

Influence of fluctuating salinity on insecticide tolerance of two euryhaline arthropods.

Among many other abiotic variations in an estuarine ecosystem, osmotic stress is an inescapable part of life. Organisms living in such environments must cope with changing osmotic conditions by either behavioral or physiological adaptations. Pollutants may increase the physiological stresses that an osmoregulating animal may encounter. We have developed a flow-through system that exposes test species to insecticides and continuously changing salinity conditions. This system has provided an insight into how susceptibility of a species to an insecticide can be affected by changing concentrations of salinity. Toxicity tests using this system were conducted with two arthropod species that are found in saline habitats: mosquito Aedes taeniorhynchus (Wiedemann) and brine shrimp (Artemia sp.). Four insecticides-aldicarb, dimethoate, imidacloprid, and tebufenozide-were studied. Both species were exposed for 48 h to a concentration of various insecticides that would cause 50% of the population to die in hyperosmotic artificial sea water (ASW). The mortality rate for both species was more acute in increasing salinity (10-200% ASW) than in decreasing salinity (200-10% ASW) conditions. A. taeniorhynchus was more susceptible than Artemia when exposed to its hyperosmotic LC50 concentration of toxicant while experiencing a change in salinity, e.g., adjusting to a changing salinity decreased the LT50. Our results indicated a change in salinity; more importantly, the direction of change altered the susceptibility of these organisms.

Aedes↗

PubMed2003

[Effects of marine bacteria on the growth and toxin production of red-tide algae under different pH and salinities].

The effects of strain S10 isolated from sediments of Xiamen Western Sea Area on the growth and paralytic shellfish poison (PSP) production of Alexandrium tamarense at different pH and salinities were studied. The results showed that the alga grew well at pH 6-8 and at salinity of 20-34. The toxicity of A. tamarense varied markedly at different pH and salinities: it decreased with increasing pH, while increased with salinity and reached its peak value at the salinity of 30, and then declined. The strain S10 inhibited the growth and the PSP production of A. tamarense at different pH and salinities. It had the best inhibitory function on the growth of A. tamarense at pH 7 and salinity of 34. The best inhibitory function on the PSP production of A. tamarense was at pH 7, but this inhibitory function was not related to salinity.

Bacteria↗

PubMed1995

[Mechanisms of hypertonic saline-induced bronchoconstriction in guinea pigs].

We examined whether inhalation of hypertonic saline can induce bronchoconstriction in guinea pigs, and also studied the mechanisms of this bronchoconstriction. Twenty-five male Hartley guinea pigs were divided into the following 5 groups: G-1, 0.9% saline inhalation; G-2. non-treatment and inhalation of hypertonic saline; G-3, capsaicin pretreatment and inhalation of hypertonic salines; G-4, ipratropium bromide pretreatment and inhalation of hypertonic saline; G-5, chlorpheniramine pretreatment and inhalation of hypertonic saline. RL and Cdyn were serially measured to assess bronchoconstriction, and the percent increase in RL from the value measured before inhalation of hypertonic saline (%RL) was analyzed. The maximum %RL was 9.2 +/- 3.8% in G-1, 90.6 +/- 6.6% in G-2, 11.2 +/- 5.7% in G-3, 9.0 +/- 6.0% in G-4, and 47.8 +/- 4.0% in G-5. The values in G-3 and G-4 were significantly lower than in G-2. We conclude that inhalation of hypertonic saline causes concentration dependent bronchoconstriction in guinea pigs and that both non-adrenergic non-cholinergic nerves and cholinergic nerves may play an important role in this bronchoconstriction.

Animals↗

PubMed2002

Prospective randomized study of N-acetylcysteine, fenoldopam, and saline for prevention of radiocontrast-induced nephropathy.

The objective of this study was to compare the efficacy of N-acetylcysteine (NAC), fenoldopam, and saline in preventing radiocontrast-induced nephropathy (RCIN) in high-risk patients undergoing cardiovascular procedures. We prospectively enrolled 123 patients who were scheduled for cardiovascular procedures and had a baseline creatinine > 1.6 mg/dl or creatinine clearance of < 60 ml/min. Patients were randomly assigned to receive either saline (0.45% normal saline at 1 cc/kg) for 12 hr before and 12 hr after the procedure, or fenoldopam (0.1 microg/kg/min) plus saline for 4 hr prior and 4 hr after the procedure, or NAC orally (600 mg) plus saline every 12 hr for 24 hr prior and 24 hr after the procedure. All the patients received low-osmolality nonionic contrast. RCIN was defined as an increase in creatinine level > 0.5 mg/dl after 48 hr. The incidence of RCIN was 17.7% in the NAC group, 15.3% in the saline group, and 15.7% in the fenoldopam group (P = 0.919). Of the 20 patients who developed RCIN, 2 required dialysis. Serum creatinine decreased after 48 hr (vs. baseline) in 38% patients in the NAC group, 18% in the fenoldopam group, and 15% in the saline group. In patients with chronic renal insufficiency, NAC or fenoldopam offered no additional benefit over hydration with saline in preventing RCIN.

Acetylcysteine↗

PubMed2005

Shape retention in porcine and rabbit nasal septal cartilage using saline bath immersion and Nd:YAG laser irradiation.

BACKGROUND AND OBJECTIVES: The process of altering the shape of cartilage using heat has been referred to as thermoforming, and presents certain clinical benefits in reconstructive surgical procedures within the head and neck. Thermoforming allows cartilage in the upper airway and face to be reshaped without the use of classic surgical maneuvers such as carving, morselizing, or suturing. The goal of this study was to determine the dependence of cartilage shape change on both temperature and laser dosimetry using two thermoforming methods: saline bath immersion and laser irradiation. STUDY DESIGN/MATERIALS AND METHODS: Ex-vivo rabbit and porcine nasal septal cartilages were mechanically deformed and reshaped using the two thermoforming methods. With saline bath immersion using rabbit cartilage, each specimen was deformed by securing it to a small copper tube (outer diameter 8 mm) using dental bands. For porcine cartilage immersed in a saline bath, each sample was mechanically deformed between two pieces of wire mesh attached to a semicircular acrylic block. With both porcine and rabbit cartilage, the specimen and apparatus were then immersed in a hot saline bath for time intervals varying from 20 and 320 seconds and at constant temperatures between 62 and 74 degrees C. In laser reshaping, the cartilage specimens were mechanically deformed on a jig and consecutively irradiated with an Nd:YAG laser (lambda = 1.32 microm) in several spots for 6-16 seconds and irradiances of 10.2-40.7 W/cm2 per spot. After either saline bath heating or irradiation, cartilage specimens were immersed in room temperature saline for 15 minutes, then upon removal from the jig the length between the ends of each specimen was measured in order to calculate the resulting bend angle. RESULTS: The transition zone for cartilage reshaping was defined as where a significant increase in bend angle was observed between consecutive times of immersion/irradiation at the same temperature/irradiance. For the saline bath experiments, the transition zone was observed between 59-68 degrees C and 62-68 degrees C for porcine and rabbit cartilage, respectively. Similar transition zones occurred with laser irradiation below irradiances of 20.4 W/cm2 for both porcine and rabbit cartilage. In addition, the dosimetry pairs in the transition zones produce peak temperatures below the thresholds determined from the saline bath immersion studies. CONCLUSIONS: The critical transition temperature region was determined by the sharp increase in bend angle at consecutive times of immersion at the same temperature. This range was determined to be 59-68 degrees C and 62-68 degrees C for porcine and rabbit cartilage, respectively. Similar transition zones for dosimetry occurred below 20.4 W/cm2 during cartilage irradiation in both species.

Animals↗

PubMed1996

Effects of growth hormone and insulin-like growth factor I on salinity tolerance and gill Na+, K+-ATPase in Atlantic salmon (Salmo salar): interaction with cortisol.

The potential roles of growth hormone (GH) and insulin-like growth factor I (IGF-I) in seawater (SW) acclimation of juvenile Atlantic salmon (Salmo salar) were examined. Compared to controls, fish in 12 ppt seawater given one or three injections (2-6 days) of GH (ovine, 0.2 microgram.g-1) or IGF-I (recombinant bovine, 0.05-0.2 microgram.g-1) had significantly greater salinity tolerance as judged by lower plasma sodium, osmolality, and muscle moisture content following transfer to 34 ppt. Single injections of GH and IGF-I in fish in fresh water failed to improve salinity tolerance following transfer to 25 ppt SW. Treatment of fish in 12 ppt with GH or IGF-I for 2-6 days did not increase gill Na+, K(+)-ATPase activity, but treatment with GH prevented decreases in gill Na+, K(+)-ATPase activity that occurred in controls following transfer to 34 ppt seawater. Fish in fresh water administered GH by implants (5.0 microgram.g-1) or osmotic minipumps (0.5 micrograms.g-1 day-1) for 7-14 days had greater gill Na+, K(+)-ATPase activity and salinity tolerance than controls. IGF-I administered by implants (0.5-1.0 microgram.g-1) or osmotic minipumps (0.1 microgram.g-1 day-1) for 4-14 days did not increase salinity tolerance or gill Na+, K(+)-ATPase activity. Cortisol implants (50 micrograms.g-1) also increased gill Na+, K(+)-ATPase activity and salinity tolerance after 14 days, and in combination with GH had a synergistic effect, Although IGF-I and cortisol implants had no significant effect after 7 days, in combination they significantly increased gill Na+, K(+)-ATPase activity. The results indicate that GH and cortisol can increase salinity tolerance and gill Na+, K(+)-ATPase activity of Atlantic salmon and together act in synergy. Although IGF-I can increase salinity tolerance in short-term treatments (2-6 days) in 12 ppt, it is less effective than GH in increasing salinity tolerance and gill Na+, K(+)-ATPase activity in long-term treatments (7-14 days) and in interacting with cortisol.

Acclimatization↗

PubMed1998

Potential mechanisms of the enhancement of aldicarb toxicity to Japanese medaka, Oryzias latipes, at high salinity.

In an attempt to understand underlying mechanism(s) of salinity-induced aldicarb toxicity in Japanese medaka (Oryzias latipes), aldicarb uptake, biotransformation, and its effect on acetylcholinesterase (AChE) were examined. Salinity had no effect on aldicarb uptake. However, gill microsomal flavin-containing monooxygenase (FMO) activity and a 57-kDa FMO1-like protein increased as the salinity was raised from 0.15 to 2.0%. Sulfoxidation of 14C-aldicarb by liver and gill microsomal incubations showed ninefold and 1.8-fold increases, respectively, as the salinity was raised from 0.15 to 2.0%. Formation of aldicarb sulfoxide was not affected by incubation with carbon monoxide, indicating that cytochrome P450 (CYP450) was not a primary pathway in the formation of the sulfoxide. Muscle AChE activity showed no significant relationship with salinity, although the IC50 of aldicarb to muscle AChE differed significantly between 6.21 +/- 1. 253 and 2.97 +/- 0.597 microM for 0.15 and 2.0% salinity, respectively. Aldicarb sulfoxide was 40 times more potent than aldicarb in inhibiting muscle AChE in Japanese medaka. Based on these results, we conclude that salinity-induced enhancement of aldicarb toxicity to Japanese medaka might be partly attributed to the upregulation of FMO(s), which, in turn, increase the biotransformation of aldicarb to aldicarb sulfoxide, which is a more potent inhibitor of AChE than aldicarb. In addition, salinity also seems to potentiate the anticholinesterase activity of aldicarb (the parent) through an unknown mechanism.

Acetylcholinesterase↗

PubMed1998

Epidural saline solution prior to local anaesthetic produces differential nerve block.

PURPOSE: The loss-of-resistance technique is generally used to identify the epidural space usually with normal saline. However, the effect of epidural saline on anaesthetic spread has not been demonstrated. The purpose of this study was to determine whether epidural saline affected the anaesthetic level and the quality of analgesia. METHODS: Seventy patients undergoing upper abdominal surgery received thoracic epidural anaesthesia combined with general anaesthesia. The patients were randomly allocated into three groups using epidural saline volumes of 1, 5, or 10 ml. Ten minutes after epidural injection of 12 ml mepivacaine 1%, the dermatome levels of hypaesthesia for cold and pinprick were determined by an individual blinded to the amount of saline administered. RESULTS: The levels of hypaesthesia for cold sensation were not different among the three groups (23 [14-44] total bilateral dermatomes blocked with 1 ml saline, 22 [16-41] dermatomes with 5 ml, and 24 [10-36] dermatomes with 10 ml (median [range])). However, the larger volume of saline produced decreased spread of hypaesthesia for pinprick (22 [4-41] dermatomes blocked bilaterally for 1 ml vs 16 [8-24] dermatomes for 10 ml group, P < 0.004). CONCLUSION: Our results suggest that a large volume of saline solution injected in the epidural space to elicit loss-of-resistance dilutes the local anaesthetic solution, resulting in reduced spread of the block to pinprick.

Abdomen↗

PubMed2002

Diversity of Pseudomonas spp. isolated from rice rhizosphere populations grown along a salinity gradient.

Along the coastline of Tamil Nadu, five sites were chosen to assess the diversity of Pseudomonas populations isolated from rice (Oryza sativa) cultivated along a salinity gradient. One of these sites was under organic farming while the other four were under inorganic farming. A total of 256 Pseudomonas strains isolated from these five sites were analyzed using both phenotypic (substrate utilization patterns and antibiotic resistance assay) and genotypic (PCR-RFLP of 16S rDNA) characteristics. The results derived from this study indicate that soil salinity affects rhizosphere Pseudomonas populations. It was observed that increasing salinity led to decreasing diversity. Fluorescent pseudomonads were the dominant species found in the non-saline site, while in the saline sites they were replaced by salt-tolerant species, in particular Pseudomonas alcaligenes and P. pseudoalcaligenes. An interesting observation was the increase in diversity found in the saline site under organic farming. Organic farming was found to be capable of mitigating the harmful effects of saline stress to a large extent, and restoring the Pseudomonas diversity, thereby making it comparable with the diversity encountered in the non-saline site.

Adaptation, Physiological↗