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PubMed2000

Investigation of an outbreak of Ralstonia pickettii in a paediatric hospital by RAPD.

In 1995, over a 5-day period, Ralstonia pickettii was isolated from six separate blood cultures from six paediatric patients in four different units of the Bordeaux paediatric hospital. The patients did not present fever or any other symptom of septicaemia. Epidemiological investigation cast suspicion on distilled water and 0.05% aqueous solutions of chlorhexidine used for topical disinfection as the source of R. pickettii. The organism was isolated from three of the seven distilled water specimens and from seven of the thirty-seven chlorhexidine specimens collected. Conventional biochemical tests showed no differences between isolates and antimicrobial agent susceptibility testing indicated that the six blood cultures contained the same strain of R. pickettii. This was confirmed by RAPD (random amplified polymorphic DNA) analysis. The primers P3 (5'AGACGTCCAC3') and P15 (5'AATGGCGCAG3') from the kit 'OPH Operon' (Bioprobe Systems, Montreuil, France) were used. The chlorhexidine solutions and the distilled water used to prepare the solutions were contaminated with various strains of R. pickettii including the patient strain. The distilled water originating from the local pharmacy had been deionized on an ion-exchange resin. Circumstantial evidence points to this water treatment as the source of contamination. RAPD proved to be a discriminatory and reproducible technique in this context, but antibiotyping was also very helpful in detecting outbreak and was equally discriminatory.

Bacterial Typing Techniques↗

PubMed1999

Comparison of different diluents and chromophores for spectrophotometric determination of livestock blood cholinesterase activity.

Effects of seven different blood diluents (distilled water, Triton X-100, saponin, isotonic saline solution, pH 7.5 and 8 phosphate buffers and bovine serum albumin) and two chromophores: 5, 5'-dithiobis 2-nitrobenzoic acid (DTNB) and 2,2'-dithiodipyridine (2- PDS) on blood cholinesterase determination in four domestic species (cow, sheep, goat and horse) are described and compared. Haemolytic diluents (distilled water, Triton X-100 and saponin) gave the best precision results when fresh blood was assayed. However, Triton X-100 induced lower ChE activity values in horses, and saponin yielded very high backgrounds in all species tested; so distilled water was recommended as diluent for fresh blood cholinesterase determination. In frozen samples all diluents (except Triton X-100) gave homogeneous final ChE results and showed good between-run precision. Use of 2- PDS as chromophore allowed to do kinetic measurements with approximately 1/3 less haemoglobin interference than when DTNB was employed. This fact allows the use of more concentrated whole blood samples, improving measurements accuracy and decreasing the possible reactivation of inhibited ChE. On the basis of these results, distilled water as diluent and 2- PDS as chromophore are recommended for ChE determination in whole blood.

2,2'-Dipyridyl↗

PubMed2002

Aromatic components of food as novel eliciting factors of pseudoallergic reactions in chronic urticaria.

BACKGROUND: Pseudoallergic reactions (PARs) against both additives and natural foods have been reported to elicit chronic urticaria, but in natural food the responsible ingredients are largely unknown. OBJECTIVE: The study was aimed at identifying novel pseudoallergens in food and focused on evaluating tomatoes, white wine, and herbs as frequently reported food items eliciting wheal responses in urticaria. METHODS: In 33 patients with chronic urticaria and PARs to food (proved by means of elimination diet and subsequent re-exposure with provocation meals), oral provocation tests were performed with field-grown tomatoes, organically grown white wine (whole food, steam distillates, and residues), oily extracts from herbs, and food additives. In addition, skin biopsy specimens from patients were studied for in vitro mast-cell histamine release with tomato distillate alone or on subsequent stimulation with anti-IgE, substance P, and C5a. RESULTS: Seventy-six percent of patients reacted to whole tomato (steam distillate, 45%; residue, 15%), 50% to food additives, 47% to herbs, and 44% to whole wine (extract, 27%; residue, 0%). Histamine, protein, and high levels of salicylate were only found in residues. The tomato distillate was further analyzed by means of mass spectroscopy, identifying low molecular-weight aldehydes, ketones, and alcohol as major ingredients. In vitro histamine release was not caused by tomato extract itself but was enhanced by means of subsequent stimulation with substance P and C5a but not by anti-IgE. CONCLUSION: Aromatic volatile ingredients in food are novel agents eliciting PARs in chronic urticaria. Histamine, salicylate, and a direct mast-cell histamine release are not involved in this reactivity to naturally occurring pseudoallergens.

Adolescent↗

PubMed2001

Fluoride release from new light-cured orthodontic bonding agents.

The purpose of this study was to compare the rates of fluoride release with time from 1 nonfluoridated and 3 fluoride-containing orthodontic bonding materials in distilled water and artificial saliva. Materials tested were Assure (Reliance Orthodontic Products, Itasca, Ill), Fuji Ortho LC (GC, Tokyo, Japan), Python (TP Orthodontics, LaPorte, Ind), and Transbond XT (3M Dental Products, Monrovia, Calif). Ten specimens of each material type were stored in distilled water, and 10 of each type were stored in artificial saliva at 37 degrees C. Fluoride release was measured with an ion-specific electrode. Readings were taken periodically for a total time period of 6 months. At day 1, Assure released the most fluoride into distilled water (66.2 microg/cm(2)) and into artificial saliva (65.8 microg/cm(2)), followed by Fuji Ortho LC (25.9 microg/cm(2); 18.8 microg/cm(2)), Python (6.3 microg/cm(2); 4.2 microg/cm(2)), and Transbond (0.1 microg/cm(2); 0.1 microg/cm(2)). The fluoride release rates were highest during the first days of testing, declining to lower but more stable levels. At the end of 6 months, Fuji Ortho LC released the most fluoride (3.8 microg/cm(2); 3.5 microg/cm(2)) followed by Assure (3.1 microg/cm(2); 2.8 microg/cm(2)), Python (2.6 microg/cm(2); 1.7 microg/cm(2)), and Transbond (0.1 microg/cm(2); 0.1 microg/cm(2)). The type of storage medium did not dramatically affect fluoride release. The second part of the study, undertaken after a year of sample storage, tested the 20 samples of Assure for a further 2-week period, after exposure to running and still distilled water. Although fluoride release rates declined with time, they were still higher than the 1.5 microg/cm(2) level that is referenced as inhibiting decalcification of enamel in a clinical environment. Release rates were similar in running and still water at all time points. Throughout the 6-month period, all 3 fluoride-containing materials had rates of fluoride release that could theoretically inhibit decalcification of enamel.

Acrylic Resins↗

PubMed2002

Survey of bottled drinking waters sold in Canada for chlorate, bromide, bromate, lead, cadmium and other trace elements.

Mineral, spring and other bottled drinking waters sold in Canada in the winter of 1995-96 were surveyed for chlorate, bromide, bromate, Cr(VI), Li, B, Al, Mn, Cu, Zn, Sr, Ba, Be, V, Cr, Co, Ni, As, Se, Mo, Ag, Cd, Sb, Tl, Pb, Na, K, Ca and Mg. Chlorate and bromide were determined by ion chromatography (IC) with conductivity detection, Cr(VI) by IC with colorimetric detection, bromate by solvent extraction and gas chromatography (GC), trace elements by inductively coupled plasma mass spectrometry (ICPMS), and Na, K, Ca and Mg by flame atomic absorption spectrometry (FAA). Most chemicals in the 199 samples analysed were well within national and international drinking water guidelines. World Health Organization and/or Canadian drinking water guidelines were exceeded for B (22 samples), Al (9), Cr (1), Mn (5), Ni (1), As (10), Se (24) and Pb (1). Bromate levels are reported for information purposes and are considered as the maximum concentrations in the samples. In three distilled water products, unexpectedly high concentrations of Cu (88-147 micro g l(-1)) and Ni (16-35 micro g l(-1)) were found, and a comparison of distilled and non-distilled waters from two of the brands suggested the likely cause to be contamination during the distillation process. Li concentration in one sample was at a therapeutic dose and could pose an overdose risk to individuals on Li medication.

Canada↗

PubMedDate not supplied

Role of peritoneal lavage in adhesion formation and survival rate in rats: an experimental study.

Following laparotomy, almost 95% of patients develop adhesions. To prevent adhesion formation, peritoneal lavage has been investigated and many different lavage solutions have been proposed. In this study, different peritoneal lavage solutions were evaluated, testing their ability to prevent adhesion formation. Three consecutive steps were followed: (1) The lethal dose of Eschericia coli injected in the rat peritoneal cavity was determined, (2) the morbidity and mortality rates of different solutions for peritoneal lavage (i.e., saline, twice-distilled water, antiseptics, and antibiotics solutions) was investigated, and (3) the capability of the different lavage solutions to prevent adhesion formation was tested. Two hundred and ninety-eight rats were employed in this study. After intraperitoneal injection of E. coli, infection (clinical signs and animal vitality), adhesion formation (explorative laparoscopy, peritoneumgraphy and Zühlke scale grading), and animal performance status were investigated. All differences were evaluated by chi-square and analysis of variance (ANOVA) tests. Saline solution showed a low morbidity rate with no deaths. Twice-distilled water was associated with 100% mortality rate, as opposed to 45-75% for antiseptics, and 0-3% mortality for antibiotics. Antibiotics determined higher adhesion formation by Zühlke score as compared to saline solution (p < .001), while no difference was observed between antiseptics and saline (p = NS). Peritoneal lavage with 37 degrees C saline solution was associated with low adhesion formation and high survival rate as compared to twice-distilled water and antiseptics. Antibiotics solutions had high survival rate and high adhesion formation. Twice-distilled water and antisepsis should be avoided when based on the data obtained in this work.

Animals↗

PubMedDate not supplied

Staining human lymphocytes and onion root cell nuclei with madder root.

We performed staining experiments on cells using natural dyes and different mordants using techniques that are used for wool and silk dyeing. The natural dye sources were madder root, daisy, corn cockle and yellow weed. Ferrous sulfate, copper sulfate, potassium tartrate, urea, potassium aluminum sulfate and potassium dichromate were used as mordants. Distilled water, distilled water plus ethanol, heptane, and distilled water plus methanol were used as solvents. All dye-mordant-solvent combinations were studied at pH 2.4, 3.2 and 4.2. The generic staining procedure was to boil 5-10 onion roots or stimulated human lymphocyte (SHL) preparations in a dye bath on a hot plate. Cells were examined at every half hour. For multicolor staining, madder-dyed lymphocytes were decolorized, then stained with Giemsa. The AgNOR technique was performed following the decolorization of Giemsa stained lymphocytes. Good results were obtained for both onion root cells and lymphocytes that were boiled for 3 h in a dye bath that included 4 g madder root, 4 g ferrous sulfate as mordant in 50 ml of 1:1 (v/v) methanol:distilled water. The pH was adjusted to 4.2 with 6 ml acetic acid. We conclude that madder root has potential as an alternative dye for staining biological materials.

Azure Stains↗

PubMed1962

Studies of the generalized Shwartzman reaction produced by diet. II. Feeding of fractions of oxidized cod liver oil.

By molecular distillation of oxidized cod liver oil a partial isolation of the lipid species responsible for the diet-induced generalized Shwartzman reaction in pregnant rats has been achieved. Molecular distillation produced three fractions and a residue. Qualitative and quantitative differences in each fraction were shown by determining iodine and saponification numbers and by thin layer chromatography on silicic acid. The incidence of the Shwartzman reaction was higher with fraction III than with either of the other two fractions, the residue, or the original oxidized cod liver oil. It is evident that the toxic factor or factors can be concentrated by molecular distillation. The high temperatures used in the molecular distillation destroy peroxides in the lipids. Therefore, in spite of the fact that oxidation of dietary fats is necessary to produce the reaction, peroxides in the dietary lipid are not necessary for the development of the tissue reaction. The residue fraction contains high molecular weight polymers and the incidence of the Shwartzman reaction is low in animals fed this material. It is unlikely that high molecular weight polymers are responsible for the tissue reaction. Animals that do not gain weight at a rate close to that of the normal pregnant rat do not develop the reaction. Conversion of fraction III into its ethyl esters increased the incidence of the Shwartzman reaction in two experiments. Esterification appears to "unmask" a certain amount of the active factor. The specific lipid material or materials responsible for the development of the generalized Shwartzman reaction remains to be found.

Animals↗

PubMed1998

Long-term laboratory contamination by Mycobacterium abscessus resulting in two pseudo-outbreaks: recognition with use of random amplified polymorphic DNA (RAPD) polymerase chain reaction.

Beginning in 1993, an increase in clinical isolates of Mycobacterium abscessus was observed in a single hospital microbiology laboratory. This involved a cluster of four patients in June 1993 and five patients and a quality-control culture of distilled water in May 1994. Twenty-three M. abscessus isolates recovered between 1991 and 1996 were compared by random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Sixteen of 21 clinical isolates recovered over a 6-year period and the distilled water isolate had identical RAPD-PCR patterns consistent with a single strain or clone. Only six of 15 patients had findings suggestive of clinical disease. Since the use of in-house-prepared distilled water was discontinued, no further laboratory contamination of clinical specimens has been observed. Molecular typing was the key to defining distilled water as the source of this pseudo-outbreak. Recognition of such outbreaks is important for prevention of unnecessary therapeutic and diagnostic interventions.

Adolescent↗

PubMed2001

Determination of the taste threshold of copper in water.

Copper effects on human health represent a relevant issue in modern nutrition. One of the difficulties in assessing the early, acute effects of copper ingested via drinking water is that the taste of copper may influence the response and the capacity to taste copper in different waters is unknown. The purpose of the study was to determine the taste threshold of copper in different types of water, using soluble and insoluble salts (copper sulfate and copper chloride). Copper-containing solutions (range 1.0-8.0 mg/l Cu) were prepared in tap water, distilled deionized water and uncarbonated mineral water. Sixty-one healthy volunteers (17-50 years of age), with no previous training for sensory evaluation, participated in the study. A modified triangle test was used to define the taste threshold value. The threshold was defined as the lowest copper concentration detected by 50% of the subjects assessed. To evaluate the olfactory input in the threshold value obtained, 15 of 61 subjects underwent a second set of triangle tests with the nose open and clamped, using distilled water with copper sulfate at a concentration corresponding to the individual's threshold. The taste threshold in tap water was 2.6 mg/l Cu for both copper sulfate and copper chloride. The corresponding values for distilled deionized water were 2.4 and 2.5 mg/l Cu for copper sulfate and copper chloride, respectively. In uncarbonated mineral water the threshold values were slightly higher, 3.5 and 3.8 mg/l Cu for copper sulfate and for copper chloride, respectively, which are significantly higher than those observed in tap and distilled waters (P < 0.01, Kruskal-Wallis test). The taste threshold did not change significantly when the nose was clamped. In conclusion, the median values for copper taste threshold were low, ranging between 2.4 and 3.8 mg/l Cu, depending on the type of water.

Adolescent↗

PubMed1995

Bioassays for Culex (Diptera: Culicidae) mosquito oviposition attractants and stimulants.

Bioassay methods for mosquito oviposition attractants and stimulants were developed and compared, using Culex tarsalis Coq. gravid females as test insects, and distilled water, dyed water, or Bermuda grass infusions as the test stimuli. Bioassays with sticky screens covering jars containing volatile test stimuli or with colorless and odorless Triton X100 surfactant in the aqueous oviposition medium demonstrated that gravid mosquitoes were attracted to distilled water, with the attraction increased by the addition of dye, grass infusion, or the steam distillate of grass infusion to the water. A variation of the sticky screen bioassay was used to demonstrate that the grass infusion also contained oviposition stimulants. A forced oviposition bioassay was minimally useful, because it failed to discriminate between a solution known to contain oviposition stimulants and a distilled-water control. Overall, the bioassays developed can be used to distinguish between oviposition attractants and stimulants, a distinction that cannot be made by simply counting egg rafts.

Animals↗

PubMed1999

Detection and quantification of changes in membrane-associated calcium in red spruce saplings exposed to acid fog.

Five-year-old red spruce saplings (Picea rubens Sarg.) were exposed to either (1) acid fog consisting of a mixture of H(2)SO(4) and HNO(3) adjusted to pH 2.5, (2) distilled-water fog at pH 5.6, or (3) no fog (dry control) for 3.5 hours per day, five times a week during the 1996 and 1997 growing seasons. The effect of fog on cell membrane-associated calcium (mCa) of leaf mesophyll cells was investigated with the fluorescence probe chlortetracycline (CTC). In both years, mean mCa concentrations were significantly less in needles exposed to acid fog than in needles exposed to distilled-water fog or in untreated needles. In 1997, acid-fog treatment resulted in 25 and 12% reductions in mCa in current-year needles, and 18 and 15% reductions in 1-year-old needles, compared with untreated needles and needles exposed to distilled-water fog, respectively, indicating that acid deposition induced calcium leaching from the membranes of photosynthetic mesophyll cells. Exposure to distilled-water fog also led to reductions in mCa in young needles, suggesting that water films on needle surfaces can induce losses by diffusion between the needle interior and surface. Consistent with the chamber studies, field data obtained from red spruce trees at two sites in Maine showed that low mCa concentrations in needles were associated with exposure to acid fog.

Journal Article↗

PubMedDate not supplied

Home-prepared saline: a safe, cost-effective alternative for wound cleansing in home care.

OBJECTIVE: The purpose of this study was to determine (1) the rate of contamination for a normal saline solution prepared with distilled water and salt when stored at room temperature and (2) when stored under refrigerated conditions; and (3) to compare the rate of contamination for solutions prepared and stored under controlled conditions with those prepared and stored in patients' homes. DESIGN: This quasi-experimental study examined the bacterial content of saline made with distilled water and stored at room temperature and that of saline stored in a refrigerator. SETTING: A large urban home health agency was the setting for the study. METHODS: Eight teaspoons of table salt were added to 1-gallon jugs of distilled water purchased from a grocery store to produce a normal saline solution. Two gallons of the prepared solution were stored at room temperature (80 degrees F) and 2 were stored in a refrigerator (48 degrees F). Cultures were taken from each of the 4 bottles of prepared solution immediately following preparation and at weekly intervals until bacterial growth occurred, or 4 weeks after preparation. RESULTS: All tested solutions were negative for bacterial growth at baseline. Cultures of the solution stored at room temperature were positive for bacterial growth 2 weeks after preparation, whereas those stored under refrigerated conditions remained free of bacterial contamination 4 weeks after preparation. Two "patient-prepared" solutions were tested at 3 weeks, and both were negative for bacteria at that time. Three patient-prepared solutions were tested at 4 weeks, of which 2 showed no bacterial growth in 48 hours, whereas 1 revealed 600 cfu/mL of Pseudomonas species. CONCLUSIONS: The results of this small study suggest that saline solutions produced by adding table salt to distilled water will remain bacteria-free for 1 month if refrigerated. Additional studies are needed to confirm these findings.

Clinical Nursing Research↗

PubMed2002

Influence of moderate drinking on purine and carbohydrate metabolism.

BACKGROUND: We examined the influences of a moderate intake level of three types of alcoholic beverages--beer, whisky, and Shochu (Japanese distilled liquor)--on purine and carbohydrate metabolism and excretion in healthy male volunteers, concerning (1) the extent of contribution of purine bodies contained in beer to uric acid metabolism and (2) a comparison between two types of distilled spirits with (whisky) and without (Shochu) aging in oak wood barrel storage. METHODS: Three sets of studies were conducted in which 10 to 13 healthy adult men were instructed to drink three types of alcoholic beverages at a slightly higher level (0.8 ml of ethanol equivalent/kg body weight) than moderate drinking (approximately 30.4 ml or less for men). A low purine beer was test-manufactured by treating nucleosides that were contained in wort and remained in beer with purine nucleoside phosphorylase derived from Ochrobacterium anthropi, thereby converting them into corresponding purine bases that were easily assimilated by beer yeast. RESULTS: Although beer intake enhanced the level of serum uric acid by 13.6%, blood glucose by 26.7%, and insulin level by 5.1-fold, drinking a moderate level of distilled liquor (whisky, Shochu) did not increase the serum uric acid level or the other two parameters. The serum uric acid level observed after drinking beer with a purine body concentration reduced by 28% (68% in nucleosides and purine bases) was almost identical to the level observed after drinking regular beer. Whisky has been found to have a property that decreases the serum uric acid level. Excretion of uric acid from blood is increased by 27% after drinking whisky. CONCLUSIONS: Moderate drinking of distilled liquors did not enhance serum uric acid level, blood glucose, or insulin level in healthy male subjects. Increased serum uric acid after beer intake could not be explained mostly with their purine body congeners. Whisky showed the eliminative property in serum uric acid through excretion of it from blood to urine. At a moderate drinking level, beer and whisky have different effects on purine metabolism or excretion.

Adult↗

PubMed2004

Water and electrolyte absorption from hypotonic oral rehydration solution in rat small intestine and colon.

BACKGROUND: The authors evaluated and compared the efficacy of hypotonic oral rehydration solutions (ORS), isotonic ion solutions, and distilled water to elucidate the relation between net water absorption and osmolality, or between electrolyte absorption and their ion concentrations in rat small intestine and colon. METHODS: Water and electrolyte absorption from two hypotonic ORS (Solita-T granules No. 2 [STG2]; sodium 60 mEq/L, osmolality 249 mOsm/L, Solita-T granules No. 3 [STG3]; sodium 35 mEq/L, osmolality 199 mOsm/L), two isotonic ion solutions (Aqualight [AL]; sodium 30 mEq/L, osmolality 290 mOsm/L, Pocarisweat [PS]; sodium 21 mEq/L, osmolality 300 mOsm/L), and distilled water, were evaluated by an in vivo perfusion technique with the small intestine and colon of anesthetized rats. RESULTS: In the small intestine and colon, two hypotonic ORS significantly promoted net water absorption much greater than did two isotonic ion solutions (P < 0.05). Net sodium absorption from two hypotonic ORS was significantly greater than that from two isotonic ion solutions (P < 0.05). Sodium absorption from all solutions was greater in the colon than in the small intestine. Distilled water did not contribute to give net water absorption in the small intestine, but in the colon, it caused almost equivalent net water absorption to that by two hypotonic ORS. The largest amount of sodium secretion from the small intestine and colon was induced by distilled water. CONCLUSIONS: These data indicate that low osmolality is a crucial factor to facilitate water absorption, and the electrolytes, sodium and chloride, can effectively be salvaged in the colon.

Animals↗

PubMed1994

Microwave processing for immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA) in formalin-fixed and paraffin-embedded tissue.

The effect of microwave irradiation on the immunoreactivity of proliferating cell nuclear antigen (PCNA) in five primary breast carcinomas, a tonsil with hyperplasia, and a seminoma of the testis was evaluated in formalin-fixed and paraffin-embedded sections using the monoclonal antibody PC-10. The tissues were fixed in 4% buffered formaldehyde for 6, 24, 28, 72 h, and 1 week. Before incubation with the primary antibody, sections were microwaved for x2 5 min in distilled water, in citrate buffer, or they were processed routinely without microwave irradiation. In sections microwaved in distilled water the immunoreactivity was found to be independent of the length of fixation. PCNA immunoreactivity in sections microwaved twice in citrate buffer was not satisfactory. The PCNA immunoreactivity in sections which were routinely processed without microwave irradiation was markedly decreased after 48 h of fixation, and was nearly absent in sections fixed for up to 1 week. In sections processed without microwave irradiation the optimal dilution of the primary antibody was 1:10, whereas in sections microwaved twice in distilled water the optimal dilution was 1:600. The morphology of the tissue was well preserved after microwave processing. We therefore recommend microwave processing in distilled water for x2 5 min for demonstration of PCNA in formalin-fixed and paraffin-embedded sections using the monoclonal antibody PC-10, since this technique yields optimal staining reactions independent of the length of fixation.

Breast Neoplasms↗

PubMed1995

Mast cell tumour destruction in dogs by hypotonic solution.

Distilled water was studied as an hypoosmotic oncolysis agent to prevent mast cell tumour (MCT) recurrence following surgical excision. The results from 118 MCTs excised in 74 dogs were: surgery alone, a recurrence rate of 52.6 per cent (10/19); and surgery followed by distilled water injections into the wound, a 26.2 per cent (26/99) recurrence rate. All of 10 small MCTs (0.03 to 0.25 cm3) injected with distilled water in situ with no surgery, regressed. The present data suggest that distilled water should be considered as an adjunct to surgery for canine MCTs.

Animals↗

PubMed1970

Water uptake by the crab-eating frog Rana cancrivora, as affected by osmotic gradients and by neurohypophysial hormones.

1. The rate of water uptake across the skin was investigated in live Rana cancrivora, an euryhaline frog which has been reported to tolerate sea water. When they were exposed to distilled water at 29 degrees C, the rate of water uptake was 8.4 +/- 0.4 mul./cm(2).hr; when bathed in solutions ranging from 30 to 570 m-osmole/l., irrespective of whether the solute was sucrose, urea or NaCl, the rate of fluid uptake during the first day was inversely related to the osmolarity of the solution. No appreciable fluid movement was observed when the bathing solution had an osmolar concentration of 270 m-osmole/l.2. The rate of fluid uptake was not affected by injections of vasopressin, oxytocin or of extracts of amphibian or rat pituitary glands, irrespective of whether R. cancrivora were bathed in distilled water or in solutions of NaCl or sucrose.3. In Bufo melanostictus, in contrast with R. cancrivora, injections of neurohypophysial extracts produced a marked increase of the rate of fluid uptake.4. In the laboratory, R. cancrivora could be acclimatized stepwise to tolerate NaCl solutions up to 700 m-osmole/l. for 7 days.5. After 24 hr exposure either to distilled water or to NaCl solutions from 100 to 670 m-osmole/l., the osmolar concentration of the plasma of R. cancrivora was always higher than that of the bathing fluid. In R. pipiens or R. temporaria plasma osmolar concentration was higher than that of the bathing fluid only when the latter did not exceed 300 m-osmole/l.6. Under all conditions investigated, the osmolar concentration of the urine of R. cancrivora was always lower than that of the plasma.7. The amounts of pressor and oxytocic activities of pituitary glands of R. cancrivora kept in distilled water or in NaCl solutions up to 300 m-osmole/l. were 8.9 +/- 0.8 and 1.8 +/- 0.3 m-u./gland, irrespective of sex or body weight within the range 30-50 g. After 3 days exposure to hypertonic NaCl solutions, the amounts of pressor and oxytocic activities were 14.7 +/- 1.2 and 3.1 +/- 0.3 m-u./gland. In both instances the pressor/oxytocic ratio was 4.9. Pituitary glands of R. temporaria similarly showed increased pressor and oxytocic activities after exposure to NaCl solutions of 300-360 m-osmole/l.

Animals↗