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PubMedDate not supplied

Cytotoxicity of dental casting alloys after conditioning in distilled water.

PURPOSE: This study investigated the cytotoxicity of various types of dental casting alloys after they had been conditioned in distilled water. MATERIALS AND METHODS: The casting alloys investigated included one high-noble alloy (Bioherador N) and six base-metal alloys, including four Ni-Cr alloys (Remanium CS, Heranium NA, Wiron 99, CB Soft), one Co-Cr alloy (Wirobond C), and one Cu-based alloy (Thermobond). Ten disks from each alloy were conditioned in distilled water at 37 degrees C for either 72 or 168 hours. The cytotoxicity of the alloys was then tested on Balb/C 3T3 fibroblasts, which were exposed to the alloys for 3 days at 37 degrees C. Cell viability was determined by the MTT method. The data were analyzed by ANOVA, and follow-up comparison between the groups was carried out using Tukey and t tests. RESULTS: ANOVA revealed a significant effect of alloy type and conditioning time (P < .001). Bioherador N was significantly less toxic than all the other alloys in the 72-hour conditioned group. After 168 hours of conditioning, its cytotoxicity was not different (P > .05) from that of Remanium CS, Wiron 99, and Wirobond C. Thermobond and CB Soft were significantly more toxic than the other alloys at both conditioning times. CONCLUSION: Conditioning of base-metal alloys, other than those containing Cu, for 168 hours in distilled water makes their cytotoxicity levels comparable to that of the high-noble alloy.

Aluminum↗

PubMed2004

Repellency of aromatic medicinal plant extracts and a steam distillate to Aedes aegypti.

The repellent activity of methanol extracts from 23 aromatic medicinal plant species and a steam distillate against female blood-starved Aedes aegypti was examined in the laboratory by skin test and compared with that of N,N-diethyl-m-toluamide (deet). Responses varied according to plant species. At a dose of 0.1 mg/cm2, the repellency of extracts of Cinnamomum cassia bark (91%), Nardostachys chinensis rhizome (81%), Paeonia suffruticosa root bark (80%), and Cinnamomum camphora steam distillate (94%) was comparable to deet (82%). The duration of the effectiveness for extracts from C. cassia bark and N. chinensis rhizome was comparable to deet and lasted for approximately 1 h. Relatively short duration of repellency was observed in P. suffruticosa root bark extract and C. camphora steam distillate. The plants described merit further study as potential mosquito repellent agents.

Aedes↗

PubMed2006

[Study on ingredients of essential oils of Curcuma wenyujin extracted by supercritical-CO2 fluid extraction and steam distillation].

OBJECTIVE: To compare the ingredients of essential oils of Curcuma wenyujin extracted by supercritical-CO2 fluid extraction and by steam distillation. METHOD: GC-MS was applied in this experiment. RESULT: The ingredients and physical and chemical properties of essential oils of C. wenyujin extracted by supercritical-CO2 fluid extraction and by steam distillation are similar. CONCLUSION: Supercritical-CO2 fluid extraction is better than steam distillation in extraction time, power consumption, recovery and purity.

Carbon Dioxide↗

PubMed1990

[Weibull statistical analysis of bending strength data measured either in air or in distilled water for sintered hydroxyapatite ceramics coated on the metal substrate].

To assess the effects of H2O on the fracture stress of sintered hydroxyapatite (HAP) ceramics prepared by procedures similar to those used for HAP coated on the metal substrate, four-point bending tests were carried out at 0.5 mm/min either in air (20 C, R.H. 73%) or in distilled water (37 degrees C). Then, strength data obtained were analyzed using two-parameter weibull statistics. In each condition, the bending strength data gave a good fit to single-mode weibull distribution. Weibull analysis of the data gave weibull parameter m = 7.8, sigma 0 = 26.2 MPa in air and m = 8.1, sigma 0 = 18.5 MPa in distilled water, which were calculated assuming a surface flaw model. The mean value of bending strength was 27.3 MPa in air and 18.2 MPa in distilled water. These results indicated that a corrosive environment such as H2O affects fracture stress when measured at a constant stress rate. This effect is considered to be caused by slow crack growth of cracks, occurring at a loading level lower than those at which specimens will fail. Using the weibull distribution function estimated in this study, the effects of both dimension of specimen and stress distribution in the specimen on the mean fracture stress have been predicted.

Air↗

PubMed1989

[Effects of nebulized distilled water on tracheal reaction in asthmatic patients].

To investigate the mechanism of bronchial spasm induced by inhalation of ultrasonically nebulised distilled water (UNDW) ultrasonically nebulised solutions including hypoosmolar (distilled water, 0.3% NaCL) isoosmolar (0.9% NaCL) and hyperosmolar solutions (2.7% NaCL, 3.6% NaCL, 4.6% KCL 22.2% dextrose) were used for challenge test in 12 asthmatic patients and 10 healthy subjects as controls. The dose of solution required to induce a 20% reduction in FEV 1 (FD 20-FEV 1) was recorded. In another 10 asthmatic patients, a challenge with UNDW was conducted after pretreatment with sodium cromoglycate (SC), Ipratropine Bromide (IB) to investigate the protective effect of the two medicines. The results showed that distilled water and three hyperosmolar solutions which were of the same osmotic pressure (3.6% NaCL, 4.6% KCL and 22.2% dextrose) were most potent in inducing bronchoconstriction, and no significant difference in PD 20-FEV 1 was found among them 0.3% and 2.7% NaCL were next and 0.9% NaCL was the least potent. Normal subjects showed no response to the solutions. The SC gave significant protection to nine of the ten patients, and IB gave it to five of the ten. Our results indicate that a change in the osmolarity of the fluid lining the respiratory tract may be an important determinant of the airway response; sodium cromoglycate which inhibits the mediator release of mast cell can reduce the airway response to UNDW.

Adolescent↗

PubMed1988

Changes in numbers and types of mast cell colony-forming cells in the peritoneal cavity of mice after injection of distilled water: evidence that mast cells suppress differentiation of bone marrow-derived precursors.

Two different types of cells in the peritoneal cavity of mice produce mast cell colonies in methylcellulose. "Large" mast cell colonies are produced by bone marrow-derived precursors resembling lymphoid cells by light microscopy (L-CFU-Mast), whereas "medium" and "small" mast cell colonies are produced by morphologically identifiable mast cells (M-CFU-Mast and S-CFU-Mast, respectively). In the present study we eradicated peritoneal mast cells by intraperitoneal (IP) injection of distilled water. The regeneration process was investigated to clarify the relationship between L-CFU-Mast, M-CFU-Mast, and S-CFU-Mast. After injection of distilled water, M-CFU-Mast and S-CFU-Mast disappeared, but L-CFU-Mast increased, and then M-CFU-Mast and S-CFU-Mast appeared, suggesting the presence of a hierarchic relationship. When purified peritoneal mast cells were injected two days after the water injection, the L-CFU-Mast did not increase. In the peritoneal cavity of WBB6F1-+/+ mice that had been lethally irradiated and rescued by bone marrow cells of C57BL/6-bgJ/bgJ (beige, Chédiak-Higashi syndrome) mice, L-CFU-Mast were of bgJ/bgJ type, but M-CFU-Mast and S-CFU-Mast were of +/+ type. The injection of distilled water to the radiation chimeras resulted in the development of bgJ/bgJ-type M-CFU-Mast and then S-CFU-Mast. The presence of mast cells appeared to suppress the recruitment of L-CFU-Mast from the bloodstream and to inhibit the differentiation of L-CFU-Mast to M-CFU-Mast.

Animals↗

PubMedDate not supplied

Determination of ethyl carbamate in distilled alcoholic beverages by gas chromatography with flame ionization or mass spectrometric detection.

Quantitative methods are detailed for determination of ethyl carbamate in distilled alcoholic beverages by capillary gas chromatography with flame ionization detection (GC/FID) and by packed-column gas chromatography/mass spectrometry (GC/MS) using selected ion monitoring. Five g samples of distillate of known ethanol concentration are diluted with water to 25% ethanol (v/v), washed with petroleum ether, and extracted with dichloromethane prior to GC/FID or GC/MS analysis. As necessary, sample extracts that exhibit GC/FID interference are passed through alumina for additional cleanup. When internal standards (tert-butyl carbamate and n-butyl carbamate for GC/FID, or ethyl 13C-15N-carbamate for GC/MS) were used for quantitation, the limit of detection for ethyl carbamate was in the range of 5-25 ppb. Coefficients of variation ranged from 3.5 to 6.0% for GC/FID determinations, and from 1.4 to 3.2% for GC/MS. Correlation between methods for 22 random distillate samples ranging in concentration from approximately 40 to 800 ppb gave a correlation coefficient (r) of 0.996.

Alcoholic Beverages↗

PubMed1985

Isotonic solutions of mannitol, sorbitol and glycine and distilled water as irrigating fluids during transurethral resection of the prostate and calculation of irrigating fluid influx.

The aim of the study was to evaluate the clinical properties of some irrigating fluids used in transurethral resection of the prostate, to study humoral changes and disposition of the various fluids and solutes on intravenous absorption and, finally, to draw conclusions concerning a suitable composition of irrigation fluid. 60 patients undergoing transurethral resection of the prostate were included in the study. Plasma concentrations of mannitol, sorbitol and glycine were determined (during and after operation) as indicators of intravenous irrigation fluid influx. The serum concentration of prostatic acid phosphatase and, in patients irrigated with distilled water, the postoperative increase in plasma haemoglobin and the serum lactate dehydrogenase increase were used as semiquantitative estimates of fluid influx. A wide-ranging series of biochemical analyses was performed on blood in all cases before, during and after the resection (inter alia, sodium, albumin, haptoglobin in serum). The half-lives in plasma were estimated for mannitol, sorbitol and glycine. Fluid absorption was calculated in several ways. Haemodilution occurred with all iso-osmolar solutions on absorption but not with distilled water. The dilution effect of glycine solution was the most pronounced. Calculation of absorbed fluid volumes gave values up to 3.0 litres. Plasma osmolality was unchanged with all irrigating fluids used. The half-life in plasma for sorbitol was about 30 min, for glycine about 90 min and for mannitol about 120 min. Glycine entered muscle cells and changed the amino acid pattern. There was an increase in the serine and ammonia concentrations in plasma postoperatively. On absorption of distilled water there was an increase in the concentration of plasma haemoglobin and in erythrocyte-derived enzymes. The immediate postoperative concentration of glycine, mannitol and sorbitol in plasma was used to calculate fluid absorption. These concentrations showed good correlation with the immediate postoperative decrease in serum sodium concentration. The serum sodium decrease can be used for calculations of the absorbed fluid volume. On absorption of large volumes of water with haemolysis products, kidney damage is possible. The osmotic diuretic effect of mannitol gives a tendency to low postoperative blood pressure if combined with an intravenous diuretic. Water as an irrigating fluid can be recommended for diagnostic purposes and for general bladder surgery.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

PubMed1983

Use of distilled water as a rinsing solution for intracellular observation by scanning electron microscopy.

A new specimen preparation to reveal intracellular structures is introduced and its application to some tissues is demonstrated. By this method, intracellular structures are easily observed by SEM. Moreover, some parts of the cells and tissues are cleaved and dissociated, and interesting structures are revealed. Tissues are fixed with 1% osmium tetroxide, rinsed with distilled water and freeze cracked with 50% DMSO. The cracked specimens are rinsed with distilled water to remove cytoplasmic matrix. The author calls this method "Osmium-DMSO-distilled Water method (O-D-W method)". When prepared by this method, intracellular structures such as mitochondria and endoplasmic reticulum are easily demonstrated three-dimensionally by SEM. Sometimes, the nucleus is removed during the specimen preparation procedure and endoplasmic reticulum around the nucleus is seen three-dimensionally. When cells and tissues are cleaved and dissociated, lateral surface of the intestinal epithelium and the reverse side of the microvillous border is also observed. Peritoneal cells lining the liver is also detached from the basement membrane and the surface of the basement membrane is exposed.

Animals↗

PubMed1983

Lysosome injury by perfusion of the isolated rat liver with ethanol or a molasses distillate (cachaça).

An isolated rat liver perfusion model was used to study the effects of acute exposure of the organ to either ethanol or a molasses distillate (cachaça). When ethanol (72 mM) or a molasses distillate (68 mM ethanol) was added to the perfusion fluid, lysosomal injury was indicated by the increased release of tartrate-inhibited acid phosphatase activity at the end of a 3 h period of perfusion. Other cellular compartments were not significantly damaged in these acute experiments, as judged by the release of aspartate and alanine aminotransferases, lactate dehydrogenase and alkaline phosphatase. The behavior of both ethanol itself and the alcoholic beverage was similar as far as enzyme release is concerned but only the molasses distillate caused significant acidosis (a decrease in perfusate pH) at the end of a 3 h period of perfusion. These data may be of importance for a better understanding of the hepatic damage caused by alcohol abuse and useful for laboratory investigation of alcohol intoxication.

Alcoholic Intoxication↗

PubMed1982

Screening procedure for detection of volatile N-nitrosamines in cooked bacon by one-trap mineral oil vacuum distillation and thermal energy analyzer.

A rapid screening procedure for the detection of volatile N-nitrosamines in fried bacon has been developed for the regulatory monitoring of bacon. This procedure uses vacuum mineral oil distillation of an alkaline sample. The distillate is collected in a prewet trap immersed in liquid nitrogen. After thawing, the distillate is transferred to a separator. The trap is rinsed with methylene chloride which is then used to extract the nitrosamines. The methylene chloride is dried with Na2SO4 and concentrated. A gas-liquid chromatograph coupled to a thermal energy analyzer is used to identify and quantitate the nitrosamines. Recoveries of 7 volatile N-nitrosamines added to 25 g fried bacon at the 10 ppb level (microgram/kg) ranged from 78 to 92%.

Animals↗

PubMed1981

[Chloride cells of the gills and the interrenal gland of Dasyatis pastinaca (L.) (Elasmobranchii) skates during adaptation to distilled sea water].

During adaptation of the skate Dasyatis pastinaca (L) to distilled sea water (7.1%) resulted in decreasing concentration of sodium, urea in blood serum, reduction in the chloride cells volume, their nuclei and increase of the apical part of the cell free from mitochondria (and occupied by the endoplasmic reticulum) are observed. Owing to uniformity of the morphometric changes of the chloride cells revealed in two types, during adaptation of the skate to the distilled sea water, as well as adaptation to its increased salinity, it is possible to conclude that in the gill of selachians there are chloride cells of one type with various functional activity. Adaptation of the skate to the distilled sea water is connected with removal of lipid inclusions out of the cells of the interrenal gland.

Adaptation, Physiological↗

PubMed1994

Changes in the distribution of F-actin in the fission yeast Schizosaccharomyces pombe by arresting growth in distilled water: correlative studies with fluorescence and electron microscopy.

Freeze-substitution electron microscopy of Schizosaccharomyces pombe cells starved in distilled water was conducted to define ultrastructural counterparts of actin visualized by fluorescence microscopy using rhodamine-conjugated phalloidin (Rh-ph). Starvation in distilled water caused remarkable changes in actin distribution and ultrastructural changes in S. pombe. Fluorescence microscopy of the starved cells showed that the dots of actin at the growing ends became thick actin cables via an enlarged patched form of actin. These changes were reversible, and growth-arrested cells resumed their original pattern of actin distribution upon return to growth medium. Electron microscopy of starved cells showed bundles of thin filaments and clusters of filamentous balls in the cytoplasm, which corresponded to the actin cables and enlarged actin dots, respectively, as seen by fluorescence microscopy. Vesicles polarized at the growing cell ends were dispersed in the cytoplasm by distilled water treatment, indicating that actin organization plays a role in directing vesicle location.

Actin Cytoskeleton↗

PubMed1993

[Bronchial hyperreactivity to distilled water].

For an epidemiological study 446 children were challenged with distilled water. The protocol consisted of 10 minutes tidal inhalation of an ultrasonically nebulized aerosol of distilled water. For children presenting with a clinical diagnosis of asthma the odds ratio for a positive challenge test was 9.1 compared to non-asthmatics [95% confidence intervals: 2.4-34.9; p = 0.001]. Symptoms cough (p = 0.03), cough at night (p = 0.03) and atopy defined by prick-test (p = 0.001) were also significantly associated with a positive challenge. The easy conduct of our protocol, the--from a pathophysiological point of view--"close to asthma" stimulus, and the small number of side-effects, indicate that the challenge with distilled water can be regarded as an alternative to metacholine provocation testing.

Aerosols↗

PubMed1984

Carcinogenicity of petroleum lubricating oil distillates: effects of solvent refining, hydroprocessing, and blending.

Certain refining processes were investigated to determine their influence on the dermal carcinogenic activity of petroleum-derived lubricating oil distillates. Specifically, the effects of solvent refining, hydroprocessing, a combination of both processes, and the blending of oils processed using each technique were evaluated in standard mouse skin-painting bioassays. The refining process used as well as the level or severity of treatment greatly influenced the carcinogenic outcome of processed lubricating oils. Solvent refining at severities normally used appeared to eliminate carcinogenicity. In contrast, hydroprocessing alone at mild levels of treatment was successful only in reducing the carcinogenic potency; severe hydroprocessing conditions were necessary to eliminate carcinogenic activity without the use of additional refining processes. Carcinogenic activity could also be eliminated by following moderate solvent refining with mild hydroprocessing. Blending of hydroprocessed oils with solvent-refined oils resulted in a substantial reduction or even elimination of carcinogenic activity. However, the degree of protection obtained varied with the particular distillates used and appeared largely dependent on the inherent biological activity of the hydroprocessed oil.

Animals↗

PubMed1994

Evaluation of the genetic toxicity of middle distillate fuels.

Petroleum middle distillate (PMD) fuels are mixtures of hydrocarbons that distill between approximately 170-370 degrees C. Commercial products that fall into this category include kerosine, diesel fuel, jet fuel, and home heating oil. These products contain both saturated (paraffins and cycloparaffins) and aromatic species, but because of the boiling range normally contain very small amounts of the 3-6 ring polycyclic aromatic hydrocarbon (PAH) constituents, which are considered to be carcinogenic. Nevertheless, there is evidence of weak tumorigenic activity when these materials are repeatedly applied to mouse skin. In the current studies representative products were tested in two commonly used, short-term assays for genetic toxicity, the Salmonella/mammalian microsome mutagenicity assay and the mouse bone marrow micronucleus test. All samples were inactive in the micronucleus assay, and three were clearly inactive in the Salmonella test. Of the remaining two, one was marginally active in the Salmonella assay, and one was equivocal. The marginally active sample contained detectable levels of PAH due to the use of catalytically cracked materials as blending stocks. The results indicated that PMDs that do not contain cracked material were not mutagenic. Thus they may produce tumors via nongenotoxic processes. Those products that do contain cracked stocks may have sufficient PAH to be mutagenic in the Salmonella assay, and in those cases the PAH might also contribute to tumor formation.

Analysis of Variance↗

PubMed1985

Petroleum distillates suppress in vitro metabolic activation: higher [S-9] required in the Salmonella/microsome mutagenicity assay.

To determine if standard conditions used in the Salmonella/mammalian microsome mutagenicity assay could reliably screen complex petroleum samples, two high-boiling (700-1,070 degrees F) distillates and their separated aromatic fractions were tested. The initial mutagenic activities were inconsistent with the samples' known polyaromatic hydrocarbon (PAH) contents and observed potencies in a dermal carcinogenesis bioassay. A significant mutagenic response was observed only at S-9 concentrations 5 to 10 times higher than those used in the standard assay, supporting the use of elevated levels of S-9 in the Salmonella/microsome assay to assess the carcinogenic potential of petroleum-derived materials. All four samples masked the expected mutagenic activity of added PAHs (benzo[a]pyrene and perylene). Data suggested that petroleum distillates suppress the functional efficacy of the S-9; possible mechanisms are discussed.

Animals↗

PubMedDate not supplied

The early changes in mouse skin following topical application of a range of middle distillate oil products.

A white spirit/naphtha, three kerosines, two gas oils and a catalytically cracked light cycle oil (LCO) were applied topically to mice, three times a week for up to 6 weeks, and skin changes were examined histopathologically at intervals. The changes within 1 week of treatment appeared to depend on the effect that the physicochemical properties of each type of product had on their penetration through the skin surface or via hair follicles. With white spirit the most prominent change was widespread epidermal necrosis occurring after the second treatment, implying that the lowest boiling point materials penetrate mainly through the surface epidermis. The earliest effects with kerosines were within and around hair follicles with epidermal degeneration developing later, suggesting a predominance of follicular entry. Gas oils and LCO produced similar changes to kerosines within 1 week, gas oils producing a slower and less severe response and LCO a more severe response. In skin examined after 1-6 weeks of treatment with all middle distillates, repeated cycles of necrosis and healing responses were evident; this implied that once the epidermal barrier layer had been damaged, follicular entry became less important. The severity of the skin changes observed with these middle distillates was probably sufficient for skin tumours to arise by a non-genotoxic mechanism if a similar treatment regime was used in a long-term skin painting study. A method of avoiding excessive skin irritation is therefore essential in such a study in order to obtain a reliable prediction of the human hazard of such materials.

Administration, Topical↗