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PubMed2006

Water and salinity stress in grapevines: early and late changes in transcript and metabolite profiles.

Grapes are grown in semiarid environments, where drought and salinity are common problems. Microarray transcript profiling, quantitative reverse transcription-PCR, and metabolite profiling were used to define genes and metabolic pathways in Vitis vinifera cv. Cabernet Sauvignon with shared and divergent responses to a gradually applied and long-term (16 days) water-deficit stress and equivalent salinity stress. In this first-of-a-kind study, distinct differences between water deficit and salinity were revealed. Water deficit caused more rapid and greater inhibition of shoot growth than did salinity at equivalent stem water potentials. One of the earliest responses to water deficit was an increase in the transcript abundance of RuBisCo activase (day 4), but this increase occurred much later in salt-stressed plants (day 12). As water deficit progressed, a greater number of affected transcripts were involved in metabolism, transport, and the biogenesis of cellular components than did salinity. Salinity affected a higher percentage of transcripts involved in transcription, protein synthesis, and protein fate than did water deficit. Metabolite profiling revealed that there were higher concentrations of glucose, malate, and proline in water-deficit-treated plants as compared to salinized plants. The metabolite differences were linked to differences in transcript abundance of many genes involved in energy metabolism and nitrogen assimilation, particularly photosynthesis, gluconeogenesis, and photorespiration. Water-deficit-treated plants appear to have a higher demand than salinized plants to adjust osmotically, detoxify free radicals (reactive oxygen species), and cope with photoinhibition.

Dehydration↗

PubMed2006

The effect of salinity conditions on kinetics of trichloroethylene biodegradation by toluene-oxidizing cultures.

This study investigates the effect of salt (NaCl) conditions on the biodegradations of trichloroethylene (TCE) by mixed cultures enriched on toluene. Two cultures were separately cultivated in this investigation, involving culture LHTO4, cultivated with freshwater and culture HHTO4, cultivated with 3.5% (w/v) NaCl solution. Batch tests were conducted to elucidate the degradations of toluene, TCE and a mixture of toluene and TCE by cultures LHTO4 at salinities of 0, 2 and 3.5% and by HHTO4 at salinity of 3.5%. The measurements were analyzed with microbial kinetics. The results show that for culture LHTO4 in the resting cells, when the transient salinities increased from 0 to 3.5%, the maximum specific rate of TCE degradation, k(TCE), declined from 2.28 to 1.45 d(-1), and the observed TCE transformation capacity, T(c,obs), decreased from 0.060 to 0.036 mgTCE/mgVSS. In the presence of toluene, TCE degradation was more inhibited by toluene (inhibition coefficients, K(I,TOL) were 0.8, 2.2, and 0.96 mg/L for salinity 0, 2, and 3.5%, respectively) than toluene degradation was by TCE (K(I,TCE) were 14, 5.8, and 1000 mg/L for salinity 0, 2, and 3.5%, respectively). Under long-term salinity stress, the culture HHTO4 maintained its capacity to utilize toluene but lost its effectiveness in the cometabolic transformation of TCE: k(TCE) fell to 0.25 d(-1) and T(c,obs) dropped to 0.024 mgTCE/mgVSS. This work reveals that the degradation of TCE by toluene-oxidizing cultures under saline conditions can be best described by the chosen kinetic equations and experimentally estimated constants, which can thus be used to lay a foundation for the rational design of biological processes to remove TCE from saline solutions.

Benzene↗

PubMed2004

Treatment of chronic sialadenitis by intraductal penicillin or saline.

PURPOSE: We sought to describe the treatment of chronic sialadenitis by intraductal penicillin or saline. PATIENTS AND METHODS: The study group consisted of 32 males and 23 females with chronic submandibular sialadenitis aged 12 to 65 years and 16 males and 11 females with chronic parotitis aged 8 to 65 years who were treated by intraductal instillation of penicillin or saline. RESULTS: In the patients with submandibular sialadenitis, 44 patients treated with penicillin and 11 treated with saline became symptom free; symptoms recurred in 3 treated with penicillin, of whom 2 became symptom free after further instillations and 1 after removal of a sialolith at the ductal orifice; and follow-up of 22 patients verified that 18 treated with penicillin and 4 with saline had been symptom free for 1 to 15 years and 1 to 3 years, respectively. In the patients with parotitis, 18 patients treated with penicillin, 8 treated with saline, and 1 treated with both became symptom free; symptoms recurred in 1 treated with penicillin and 1 with saline, both of whom became symptom free after further instillations; and follow-up of 15 patients verified that 11 treated with penicillin, 3 with saline, and 1 with both had been symptom free for 1 to 14 years, 2 to 12 years, and 3 years, respectively. CONCLUSION: The intraductal instillation of penicillin or saline is a simple and surprisingly successful technique for the treatment of chronic sialadenitis.

Adolescent↗

PubMed2005

Toxicity of antifouling biocides to the intertidal harpacticoid copepod Tigriopus japonicus (Crustacea, Copepoda): effects of temperature and salinity.

Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 x 3 x 4 factorial design (i.e. two temperatures: 25 and 35 degrees C; three salinities: 15.0 per thousand, 34.5 per thousand and 45.0 per thousand; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96 h-LC50s of Cu and TBT were 1024 and 0.149 microg l(-1) respectively (at 25 degrees C; 34.5 per thousand) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using 'concentration' as the covariate and both 'temperature' and 'salinity' as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle.

Analysis of Variance↗

PubMed2002

Astrocyte stellation in saline media lacking bicarbonate: possible relation to intracellular pH and tyrosine phosphorylation.

Primary cultures of astrocytes exhibit a polygonal morphology, but on treatment with agents that increase cAMP they change to stellate cells. We found that astrocyte stellation also occurred on replacing the culture medium with saline buffered with HEPES. However, stellation did not occur when the medium was replaced with saline buffered with bicarbonate/CO(2) provided Ca(2+) was present. Since exposure of astrocytes to media lacking bicarbonate results in a decrease in intracellular pH (pH(i)) we sought evidence for an association between pH(i) and morphology. Astrocytic pH(i) was monitored for 60 min after transferring the cells to HEPES or bicarbonate-buffered saline. HEPES-induced stellation was associated with transient acidification which coincided with the morphological changes. Acidification was not observed in cells transferred to bicarbonate-saline. However when cytoplasmic acidification of cells in bicarbonate-saline was induced pharmacologically, rapid stellation occurred. Stellation induced by cAMP is reversed by activation of the RhoA pathway with lysophosphatidic acid (LPA). Here we found that LPA inhibited HEPES-induced stellation, but only with Ca(2+) present. Inhibition of stellation by LPA+Ca(2+) was associated with transient acidification followed by modest alkanization. A close association of tyrosine phosphorylation with stellation and pH(i) was observed. Thus incubation of astrocytes in HEPES-saline with orthovanadate to inhibit dephosphorylation abolished stellation and acidification; conversely incubation of cells in bicarbonate-saline with genistein to inhibit tyrosine kinases caused stellation and major acidification. Acidification may be one of several factors resulting in stellation, but it is not a necessary factor since stellation without acidification was observed in bicarbonate-saline lacking Ca(2+).

Ammonium Chloride↗

PubMed2002

Effects of temperature and volume on intraperitoneal saline-induced changes in blood pressure, nociception, and neural activity in the rostroventral medulla.

ON and OFF cells of the rostral ventromedial medulla are hypothesized to modulate nociception with ON cells facilitating pain and OFF cells inhibiting pain. The current study analyzed the effects of intraperitoneal saline at different volumes and temperatures on nociception (tail flick reflex), blood pressure, and the activity of ON and OFF cells in lightly anesthetized rats. At large volumes (20 cc/kg), room temperature saline excited 7/11 ON cells and inhibited 10/12 OFF cells for 2-5 min. In contrast, large volumes (20 cc/kg) of body temperature saline (37 degrees C) excited only 1/10 ON cells and inhibited only 3/13 OFF cells, and small volumes (1-2 cc/kg) of room temperature saline excited only 3/10 ON cells and inhibited only 4/11 OFF cells. Tail flick latency increased following saline administration at large volumes with a significant effect of time, but not temperature. The excitation of ON cells and inhibition of OFF cells indicate that cold intraperitoneal saline could be painful and the increase in tail flick latency may indicate a diffuse noxious inhibitory control. It is also possible that the changes in ON and OFF cell activity caused a hyperalgesia that was masked by a simultaneous hypoalgesia that was mediated independent of the ON and OFF cells. Because intraperitoneal saline may produce pain or hyperalgesia, care should be used when saline is used experimentally or clinically.

Action Potentials↗

PubMed2001

Investigation of the uterine cavity and fallopian tubes using three-dimensional saline sonohysterosalpingography.

OBJECTIVE: To compare three-dimensional saline sonohysterosalpingography (SHSG) to X-ray hysterosalpingography (HSG) for the evaluation of the uterine cavity and fallopian tubes. PATIENT POPULATION: Fifteen infertile women on whom X-ray HSG had been performed within 1 year prior to this study. METHOD: Fifteen infertile women underwent three-dimensional power Doppler examination of the uterus and fallopian tubes with three-dimensional SHSG during the follicular phase. Distension was achieved using sterile saline injected through a 5 French HSG catheter. Peritoneal accumulation of free fluid surrounding the ovary and tube was required for a diagnosis of a patent tube. Fluid accumulation in the cul-de-sac without visualization of the tubes was considered consistent with at least one tube being patent. RESULTS: three-dimensional saline SHSG was completed in 14 patients. One patient had cervical stenosis and the procedure could not be performed. No significant intrauterine pathology was identified by either X-ray HSG or sonography. Three-dimensional saline SHSG made false positive diagnoses of tubal occlusion in four out of seven fallopian tubes (57%). The sensitivity and specificity for detecting tubal occlusion was 75 and 83%, respectively, with a positive predictive value of 40% and negative predictive value of 95%. Detection of fallopian tube architecture was not possible with three-dimensional saline SHSG in any patient. Simultaneous use of three-dimensional Doppler did not clearly identify the flow of saline through the fallopian tubes. CONCLUSIONS: Transvaginal three-dimensional saline SHSG provides good visualization of the uterine cavity and myometrial walls in three orthogonal planes. However, it does not diagnose tubal occlusion or depict architecture of the fallopian tube as accurately as X-ray HSG. Although we were able to visualize the distal fallopian tube and fimbria with real-time imaging, we were not able to satisfactorily image the proximal tube with three-dimensional power Doppler. This technique may be reserved as an initial screening test to evaluate the uterine cavity and test patency. Patients at high risk for tubal disease by history or with suspected tubal occlusion on three-dimensional saline SHSG should be evaluated by either X-ray HSG or laparoscopy with chromopertubation. Further improvements of three-dimensional technology and contrast materials will, it is hoped, make this method comparable to X-ray HSG.

Adult↗

PubMed2000

Comparison of the metabolism of Acartia clausi and A. tonsa: influence of temperature and salinity.

In the Marseilles region (French Mediterranean coast), A. clausi is one of the most abundant copepod species of the Gulf of Fos while A. tonsa constitutes the almost exclusive copepod species of the Berre lagoon, a neighbouring semi-closed brackish area communicating with the gulf. As different ecophysiological capabilities to stand the various temperature, salinity and food conditions could explain why these two species do not coexist in the same environment, comparative experiments were performed on metabolism and feeding. The respiration and ammonia excretion of the two species were measured in different combinations of temperature (10, 15 and 20 degrees C) and salinity (15, 25 and 35 per thousand). For each temperature, at the salinity of 35 per thousand, respiration rates were less in A. clausi than in A. tonsa, the contrary being observed at the lowest salinity. At any temperature ammonia excretion was greater at the intermediate salinity in A. tonsa and least in A. clausi. In Acartia tonsa, Q(10) of respiration and excretion were minimum at the lowest salinity, while in A. clausi they were unaffected by salinity variation. The O:N atomic ratio (from respiration and ammonia excretion rates) was significantly more elevated in A. clausi (mean 21.2; range 13.6-28.7) than in A. tonsa (mean 11.3; range 4.2-25) suggesting a more proteinic oriented metabolism in the later. Feeding experiments where Dunaliella tertiolecta30 per thousand) or lagoon (<16 per thousand) salinity. The relationships between ingestion and food concentration in the two species were not significantly different. These different results are compared to other ecophysiological information concerning these Acartia species (survival tolerances, osmotic regulation, feeding behaviour) and are discussed in relation with the characteristics of their niches in the studied region.

Journal Article↗

PubMed2001

Growth, oxygen consumption, ammonia-N excretion, biochemical composition and energy content of Farfantepenaeus paulensis Pérez-Farfante (Crustacea, Decapoda, Penaeidae) early postlarvae in different salinities.

Physiological responses of early postlarval shrimp Farfantepenaeus paulensis to different salinities were evaluated. Growth, net growth efficiency (K(2)), oxygen consumption, ammonia-N excretion, protein, lipid, carbohydrate, ash and energy content were determined in postlarval stages PL VI-VII and PL XIII-XV at 5 per thousand, 15 per thousand, 25 per thousand and 34 per thousand. PL VI-VII and PL XIII-XV correspond, in the wild, to the penetration of postlarvae into estuarine zones and the adoption of benthic habits, respectively. Postlarvae were gradually acclimated to the various salinity levels in the stage PL VI-VII and were maintained there until reaching the stage PL XIII-XV. Although development time was not affected by salinity, growth was decreased at 34 per thousand. Oxygen consumption was less affected by salinity while ammonia-N excretion presented a negative correlation with salinity. In both stages, protein content was lower at 34 per thousand. In PL VI-VII, lipid was decreased at 5 per thousand, while no significant difference in lipid content was observed in PL XIII-XV. Carbohydrate and ash levels did not vary in function of salinity levels. Energy content was reduced in PL XIII-XV at 34 per thousand. Net growth efficiency (K(2)) between PL VI-VII and PL XIII-XV presented higher values at 15 per thousand and 25 per thousand, and the lowest at 34 per thousand. Enhanced energy expenditure due to osmoregulation was not detected as denoted by oxygen consumption rates. Nitrogen metabolism seems to play a key role in maintaining body fluids concentration in relation to medium salinity. It is concluded that the high degree of euryhalinity in these stages of F. paulensis may be an adaptation to ontogenetic events such as migration to estuarine areas. For aquaculture purposes, it is recommended to maintain these postlarval stages at salinities between 15 per thousand and 25 per thousand rather than 34 per thousand.

Journal Article↗

PubMed2001

Livestock wastewater treatment by a mangrove pot-cultivation system and the effect of salinity on the nutrient removal efficiency.

The present investigation compared the capacity of greenhouse pot-cultivation systems under two salinity conditions (freshwater and saline water) with two mangrove species (Bruguiera gymnorrhiza and Kandelia candel) to remove nutrients from livestock wastewater. During the whole treatment period there were relatively stable leachate TOC concentrations for wastewater-treated pots. Leachate NH4(+)-N concentration of B. gymnorrhiza pots was generally lower than that of K. candel pots. Leachate PO4(3-)-P concentration of pots receiving wastewater under freshwater condition was higher than that under saline water condition. Soil inorganic N content was more than two times higher for the wastewater treatments than that for the controls under low salinity condition and slower rate of increase under saline water condition. Soil P nutrients of both total and extractable inorganic forms significantly increased for both systems due to the discharges of livestock wastewater under both salinity conditions. The rate of increase in P contents for plants receiving livestock wastewater was 1-4 times that of the controls, much more than that in N contents (0.04-1.30 times). N nutrient removal efficiencies were 84.3% (65.6% by soil and 18.7% by plant) and 95.5% (32.2% by soil and 63.4% by plant), respectively by Kandelia candel and B. gymnorrhiza pot-cultivation systems under freshwater condition. Under saline water condition, N nutrient removal efficiencies by K. candel and B. gymnorrhiza pot-cultivation systems were 92.7% (80.7% by soil and 12.0% by plant) and 98.0% (67.6% by soil and 30.3% by plant), respectively. P nutrient removal efficiencies by K. candel and B. gymnorrhiza systems under freshwater condition were 79.2% (76.6% by soil and 2.6% by plant) and 91.8% (88.2% by soil and 3.6% by plant), respectively. The corresponding values were 88.0% (84.2% by soil and 3.8% by plant) and 97.8% (95.9% by soil and 1.9% by plant) under saline water condition.

Agriculture↗

PubMed2000

Leaf gas exchange and solute accumulation in the halophyte Salvadora persica grown at moderate salinity.

The domestication of halophytes has been proposed as a strategy to expand cultivation onto unfavorable land. However, halophytes mainly have been considered for their performance in extremely saline environments, and only a few species have been characterized in terms of their tolerance and physiological responses to moderately high levels of salinity. Salvadora persica is an evergreen perennial halophyte capable of growing under extreme conditions, from very dry environments to highly saline soils. It possesses high potential economic value as a source of oil and medicinal compounds. To quantify its response to salinity, S. persica seedlings were exposed to 200 mM NaCl for 3 weeks, and growth, leaf gas exchange and solute accumulation were measured. The presence of NaCl induced a 100% increase in fresh weight and a 30% increase in dry weight, relative to non-salinized controls. Increases in fresh weight and dry weight were not associated with higher rates of net CO(2) assimilation, however. Analysis of ion accumulation revealed that S. persica leaves accumulated Na(+) as a primary osmoticum. The concentration of Na(+) in leaves of salinized plants was approximately 40-fold greater than that measured in non-salinized controls, and this was associated with significant reductions in leaf K(+) and Ca(2+) concentrations. In addition, a significant accumulation of proline, probably associated with osmotic adjustment and protection of membrane stability, occurred in roots of salinized plants.

Journal Article↗

PubMed1997

Efficacy of normal saline solution versus heparin solution for maintaining patency of peripheral intravenous catheters in children.

OBJECTIVES: Literature reports support the use of normal saline solution for maintaining patency of peripheral intermittent intravenous infusion devices (PIID) in the adult population; however, there are limited data regarding this policy in the pediatric population. The purpose of this study was to establish the effects of heparin flush and saline solution flush solutions in maintaining patency of infusion devices in the pediatric population, and to establish cost-saving implications related to both procedures. The specific aims of the study included the following: (1) to determine the efficacy of normal saline solution flush for peripheral i.v. access devices for the pediatric population, and (2) to establish cost-saving implications related to normal saline solution versus heparin flush for PIIDs in terms of pharmacy costs and costs related to nursing time. METHODS: The study was a prospective, randomized, double-blind controlled trial of flushing solutions. The control group (n = 77) received 3 ml of a 10 units heparin/ml normal saline solution i.v. flush. The experimental group (n = 73) received 3 ml of normal saline solution only for the i.v. flush. Routine hospital procedure for flushing was followed during the study period. RESULTS: Descriptive and correlation statistics were used to analyze the data; chi 2, t test, and analysis of variance were calculated. There were no significant differences between the two groups for demographics or complications. Annual cost savings were computed for both procedures with an estimated annual savings of nursing time and unit cost of solutions equaling $27,594. The savings per procedure was estimated at $9.45. DISCUSSION: This study provided support for the efficacy of normal saline solution as an alternative to heparin solutions for the maintenance of peripheral i.v. devices. Implications include elimination of risks associated with heparin (drug incompatibilities, thrombosis syndrome, hypersensitivity reactions, local tissue damage, and iatrogenic hemorrhage); decreased potential for infection associated with breaks in the integrity of the i.v. system; substantial money savings as a result of the change to normal saline solution realized by the patient and the institution; and decreased nursing time. By simplifying the procedure, nurses have more time to provide aspects of nursing care to patients.

Adolescent↗

PubMed2002

Gender differences in the effect of salinity on aldicarb uptake, elimination, and in vitro metabolism in Japanese medaka, Oryzias latipes.

Toxicity studies have shown that salinity enhances the toxicity of aldicarb to female Japanese medaka. Although previous studies indicated that biotransformation may be important in these effects, other dispositional factors may play a role in this scenario. Male and female medaka were separately acclimated to three salinity regimens: 1.5, 12, and 20 parts per thousand (per thousand) for 2 weeks. The fish were then aqueously exposed to 96 h LC(20) of [(14)C]aldicarb for 24 h. [(14)C]aldicarb equivalents (aldicarb and its metabolites) were measured in whole-fish homogenates of half the fish. The other half of the population was transferred to clean water for 48 h. During this 48 h period, fish were removed and whole animal homogenates were measured radiometrically at 0, 2, 4, 8, 12, and 24 h time points. Salinity did not have an effect on the uptake of aldicarb in either male or female medaka. Elimination data showed that elimination of [(14)C]aldicarb equivalents was biphasic. Salinity did not have an effect on the elimination half life in either males or females. In vitro metabolism using gill and liver microsomes from fish acclimated to three salinity regimens showed that aldicarb sulfoxide production by male gill microsomes increased 6-fold by salinity compared to a 9-fold increase in female gills. In conclusion, the increased sensitivity of female medaka to salinity enhanced toxicity seems to be caused by a higher metabolic activation of aldicarb to the sulfoxide compared to the males. This study supports the hypothesis that the differential expression and regulation of FMOs is an important factor in determining the sensitivity of euryhaline fish to aldicarb, especially at high salinity regimens.

Aldicarb↗

PubMed2002

Effects of NMDA and non-NMDA ionotropic glutamate receptor antagonists on the development and maintenance of hyperalgesia induced by repeated intramuscular injection of acidic saline.

Two unilateral injections of pH 4.0 saline into the gastrocnemius muscle result in a bilateral decrease in mechanical withdrawal threshold after the second injection. This decrease is significant by 4h and lasts through 1 week. The purpose of this study was to characterize the involvement of both N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in the spinal cord dorsal horn in the development and maintenance of mechanical hyperalgesia from repeated intramuscular injections of acidic saline. 2-amino-5-phosphonovaleric acid (AP5) (2-20 nmol, 10 microl, pH 7) or 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo[f]quinoxaline-7-sulfonamide (NBQX) (1-10 nmol, 10 microl, pH 8-9) was administered intrathecally to the lumbar spinal cord to block NMDA and non-NMDA ionotropic glutamate receptors in the dorsal horn, respectively. Drugs were administered at one of three different time points: (1) prior to the first intramuscular injection of pH 4.0 saline on Day 0, (2) prior to the second intramuscular injection of pH 4.0 saline on Day 5, and (3) 1 week after the second injection. Mechanical withdrawal thresholds were measured with von Frey filaments before, 4h, and 24h after injection 1 and before, 4h, 24h, and 1 week after injection 2. AP5 had no effect on mechanical withdrawal thresholds when administered prior to the first intramuscular injection of pH 4.0 saline. When AP5 was administered before the second intramuscular injection, the bilateral decrease in mechanical withdrawal thresholds was delayed for up to 24h. Intrathecal administration of AP5 1 week after the second intramuscular injection of pH 4.0 saline produced a bilateral increase in mechanical withdrawal thresholds. Blockade of non-NMDA glutamate receptors in the spinal cord dorsal horn prior to either the first or second intramuscular injection of pH 4.0 saline had no effect on the development of mechanical hyperalgesia. However, spinal injection of NBQX 1 week after the second intramuscular injection of pH 4.0 saline resulted in an increase in mechanical withdrawal thresholds when compared to vehicle controls. These data suggest that both NMDA and non-NMDA glutamate receptors are involved in the maintenance of chronic, muscle-induced hyperalgesia.

2-Amino-5-phosphonovalerate↗

PubMed1997

Saline versus gadolinium-enhanced magnetic resonance arthrography of porcine cartilage.

RATIONALE AND OBJECTIVES: The authors compared saline and dilute gadopentetate dimeglumine as injectants for magnetic resonance (MR) arthrography. METHODS: Sixty-three lesions were created on the joint surfaces of six pig patellas. MR arthrography (1.5 T) was performed with the specimens in saline and then in 2 mmol gadopentetate dimeglumine by using fat-saturated two-dimensional (2D) and three-dimensional (3D) sequences. Two musculoskeletal radiologists independently interpreted the images. RESULTS: At 2D MR arthrography, reader 1 performed equally well with saline and gadolinium solutes, whereas reader 2 had better sensitivity with the saline solute (P < .05); interobserver agreement was equivalent for saline and gadolinium solutes. With 3D MR arthrography, reader 2 performed equally well with saline and gadolinium solutes, whereas reader 1 had better sensitivity (P < .0001) but poorer specificity (P < .001) with the gadolinium solute; interobserver agreement was significantly better for saline than for gadopentetate dimeglumine (P < .05). CONCLUSION: In this initial evaluation, there was no clear advantage to using gadolinium-enhanced MR arthrography over saline MR arthrography for detecting lesions in porcine hyaline cartilage.

Animals↗

PubMed2002

Differences in maintenance energy expenditure by two estuarine shrimp (Palaemonetes pugio and P. vulgaris) that may permit partitioning of habitats by salinity.

The estuarine shrimp Palaemonetes pugio and P. vulgaris co-occur across a broad range in salinity. Field surveys and laboratory lethality tests suggest that low salinity conditions favor P. pugio over P. vulgaris. This study compared energetic expenditures across a range in salinity (0.5-35 ppt) to test the hypothesis that P. pugio experiences lower maintenance-energy requirements than P. vulgaris in low-salinity habitats. Standard metabolic rate (SMR) was measured as the minimum oxygen consumption rate at 25 degrees C to estimate daily maintenance-energy expenditure. SMR was greatest at 0.5 and least at 10 ppt (irrespective of species), and greater for P. vulgaris than for P. pugio. At low salinity (1.5-3 ppt), SMR was lower for P. pugio than for P. vulgaris. Energy expenditure did not coincide with the pattern predicted based upon osmoregulatory costs alone; no reduction was observed near the reported hemolymph concentration for P. vulgaris, although a minimum was observed near the hemolymph isoionic concentration for P. pugio. A local minimum in SMR by P. pugio between 1.5 and 3 ppt contrasted with relatively high SMR of P. vulgaris across this range. It appears that low-salinity habitats are energetically more favorable for P. pugio than for P. vulgaris. The results suggest an adaptive mechanism allowing P. pugio to occupy environments that present its competitor, P. vulgaris, with greater energetic challenges. While long-term exposure to very low salinity may be detrimental to both species, energetic traits of P. pugio may confer it with greater success than P. vulgaris in habitats in which salinity periodically fluctuates to low values.

Animals↗

PubMed2001

How should salinity influence fish growth?

Development and growth (continuous in fish) are controlled by 'internal factors' including CNS, endocrinological and neuroendocrinological systems. Among vertebrates, they also are highly dependent on environmental conditions. Among other factors, many studies have reported an influence of water salinity on fish development and growth. In most species, egg fertilization and incubation, yolk sac resorption, early embryogenesis, swimbladder inflation, larval growth are dependent on salinity. In larger fish, salinity is also a key factor in controlling growth. Do the changes in growth rate, that depend on salinity, result from an action on: (1) standard metabolic rate; (2) food intake; (3) food conversion; and/or (4) hormonal stimulation? Better growth at intermediate salinities (8-20 psu) is very often, but not systematically, correlated to a lower standard metabolic rate. Numerous studies have shown that 20 to >50% of the total fish energy budget are dedicated to osmoregulation. However, recent ones indicate that the osmotic cost is not as high (roughly 10%) as this. Data are also available in terms of food intake and stimulation of food conversion, which are both dependent on the environmental salinity. Temperature and salinity have complex interactions. Many hormones are known to be active in both osmoregulation and growth regulation, e.g. in the control of food intake. All of these factors are reviewed. As often, multiple causality is likely to be at work and the interactive effects of salinity on physiology and behaviour must also be taken into account.

Acclimatization↗

PubMed2001

Salinity effect on mechanical dewatering of sludge with and without chemical conditioning.

The salinity levels of wastewater and sludge are relatively high in some coastal cities as they may use saline water for toilet flushing, and as such,the sludge dewaterability can be affected by it. The salinity effect on sludge dewaterability was therefore investigated through experimental testing of specific resistance in filtration (SRF), time to filter (TTF), and final solid content of sludge. SRF and TTF were determined using Buchner funnel tests. The final solid content was estimated by centrifuging the sludge at four levels of rotational speed. Sludge with three salinity levels (5,000, 10,000 and 20,000 ppm) were considered in this study. Coagulants such as alum, iron(II) sulfate, and organic polyelectrolytes were added to the sludgetostudythe dewaterability of such sludge with chemical conditioning. Experimental results show that doubling the salinity level of the sludge from 10,000 to 20,000 ppm shows not much change in SRF and TTF. Compared with the sludge without chemical conditioning, the addition of the coagulants to the sludge at a salinity level of 5,000 ppm drastically reduces its SRF and TTF. However, sludge with and without chemical conditioning at a salinity of 20,000 ppm has similar SRF and TTF. The final solid content of sludge increases almost linearly with salinity. Among the coagulants used in this study, the cationic polyelectrolyte is found to be better in improving sludge dewaterability, while iron(II) sulfate performs slightly better in enhancing the final solid content of the sludge.

Particle Size↗