PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Mixture effects”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1977

Survival of aerosolized bacteriophage phi X174 in air containing ozone--olefin mixtures.

The effects of ozone and ozonized olefins on aerosol survival of bacteriophage phiX174 were studied. The ozone concentrations used were between 0 and 110 parts/10(9), giving decay rates up to 0-03 min-1. The olefins used were trans-2-butene and cyclohexene in concentrations of 500 parts/10(9) and 2-4 parts/10(6), respectively. Olefins alone have no effect, whereas in combination with ozone, decay rates of 0-1 min-1 and higher were obtained. The results are discussed in relation to the viricidal effect of open air.

Aerosols↗
PubMed1978

Studies on the effect of quartz, bentonite and coal dust mixtures on macrophages in vitro.

The effect of quartz, bentonite and coal dusts as well as the effect of the artificial mixture of these dusts on TTC reduction and extra-and intra-cellular lactate dehydrogenase activity in peritoneal rat macrophages was determined in vitro. The cell-membrane-damaging effect of quartz caused a significant extracellular release of lactate dehydrogenase. Bentonite caused no extracellular enzyme release, which leads us to believe that the biological effect of this dust is shown by decrease in intra-cellular lactate dehydrogenase activity. TTC reduction was inhibited equally by quartz and qentonite. In mixtures of quartz (60%)-bentonite (40%) dust the specific effect of quartz was inhibited by bentonite in vitro and also in vivo. We obtained the same results with coal-quartz-bentonite dust mixtures in vitro. Our experiments show that comparison of the biological effects of artificial dust mixtures and airborne dust samples is justified, and prove that performing various examinations simultaneously give fuller particulars on the probable biological effect of mineral dusts.

Animals↗
PubMedDate not supplied

[Inhibition of alkaline phosphatase I of Pichia guilliermondii yeast in vitro and in vivo].

The rate of p-nitrophenyl phosphate and flavin mononucleotide (FMN) hydrolysis by the partially purified preparation of alkaline phosphatase I of Pichia guilliermondii flavinogenic yeast was studied as affected by different substrates and inorganic ions. Their Km was established to be 2.0 X 10(-4) m and 2.5 X 10(-4) M, respectively. Dephosphorylation of p-nitrophenylphosphate and FMN was inhibited competitively by beta-glycerophosphate (Ki = 3.1 X 10(-3) M, respectively). The presence of inorganic phosphate ions in the reaction mixture decreases or removes inhibition of these compounds hydrolysis by other substrates of alkaline phosphatase I. The activity of alkaline phosphatase I increases in the presence of Mg2+ and was strongly inhibited in the presence of Be2+, Cu2+, Zn2+, Cd2+ and inorganic phosphate, the mixture of Be2+ and F- being the most effective. This mixture inhibited the phosphatase activity of the partially purified preparation of alkaline phosphatase I of the cell-free extract as well as of intact cells in both the alkaline and acid zones of pH (8.6 and 5.5, respectively). Incubation of the washed iron-deficient P. guilliermondii cells in the presence of Be2+ and F- did not result in accumulation of FMN in the yeast culture. A possible role of nonspecific phosphomonoesterases in hydrolysis of FMN in vivo is discussed.

4-Nitrophenylphosphatase↗
PubMedDate not supplied

[Effect of carbostimulin and its mixture with vitamin D3 on the mineralization process of the bone callus in rabbits].

Mineralization of rabbit bone callus was studied within 15 days after resection of the upper part of radius bone inder conditions of treatment with carbostimuline and its mixture with vitamin D3. Content of calcium in the bone regenerate was increased by 40.8% after administration of carbostimuline and--by 70.5% after treatment with mixture containing vitamin D3. These preparations caused only slight effects on the phosphorus content. Dry residue in the regenerate os f animals, treated with the preparations, was increased approximately 2-fold (43% and 23%, respectively, p less than or equal to 0.001) as compared with control group. Content of citric acid was distinctly higher in the bone tissue of the treated animals. Within 15 days after the operation content of sialic acids wanormalized in blood serum of the animals. The data obtained were corroborated by X-ray and histologic examinations.

Animals↗
PubMed1977

The effect of a proteolytic enzyem mixture (Orenzyme-Forte) on experimentally induced pulpitis.

A proteolytic enzyme mixture, Orenzyme-Forte, containing trypsin, chymotrypsin, and ribonuclease was used to treat experimentally induced pulpitis in the teeth of three monkeys. Assessment by means of the criteria of Stanley showed that the enzyme mixture induced better healing than a zinc oxide--eugenol dressing. When the two were used simultaneously, a synergistic effect was seen. We suggest that this enzyme mixture may be useful in clinical practice in the treatment of pulpitis.

Animals↗
PubMed1979

Studies on egg disinfection.

Various concentrations of alkyldimethylbenzyl ammonium chloride (QAC), Na2CO3, and ethylenediaminetetracetic acid (EDTA) were tested for antimicrobial activity singly and in combination against Escherichia coli, Arizona hinshawii, and Pseudomonas aeruginosa. Bactericidal activity of the reagents were evaluated in embryonating eggs, trypticase soy broth, and a medium containing lecithin. Toxicity of the chemicals was assayed in embryonating eggs. An appraisal was made of an egg-washing solution composed of 250 ppm QAC, 100 ppm Na2CO3, and 10 and 100 ppm EDTA. The mixture was effective and nontoxic for this purpose. All egg treatments had an adverse effect on fertility and hatchability. Using the temperature differential procedure in egg dipping, the disinfectant mixture was relatively nontoxic if 10 ppm EDTA was used with 3000 ppm tylosin tartrate. One hundred parts per million of the chelator in the dip solution caused excessive embryo mortality due to synergistic toxicity with the antibiotic. The germicidal action of the QAC solution was markedly increased with Na2CO3. Ten parts per million EDTA did not improve the biocidal effect of QAC solutions in distilled water but increased bactericidal activity in tap water that contained 16 ppm Ca and 22 ppm Mg.

Animals↗
PubMedDate not supplied

Antibacterial effect of some combinations of pesticides of pure cultures of microorganisms.

The investigations conducted showed that the antibacterial effect of dinitro-o-cresol, cuprozane, and trichlorfon is due to their chemical structure and to the species of microorganisms on which they act. Dinitro-o-cresol and Cuprozane possess selective toxicity with respect to B. anthracis and Rh. gracilis and cuprozane with respect to Ch. perfringens. The method of evaluating the effect of combinations of chemical compounds consisting of two or more components which have been developed made it possible to detect the antibacterial effect of mixtures consisting of the indicated pesticides. It was established that the combinations studied possess synergic and additive effects, which also depend on the chemical structure of the pesticides and the species of microorganisms.

Bacillus↗
PubMed1979

A decongestant-antihistamine mixture in the prevention of otitis media in children with colds.

One hundred four preschool-age patients in a private pediatric practice were treated prospectively during colds with either decongestant-antihistamine or placebo to determine if the decongestant-antihistamine mixture was effective in the prevention of otitis media. Each child received a standard dosage of the study medicine according to a double-blind, crossover design. Otitis media was diagnosed on the basis of clinical criteria. Fifteen (6.4%) of 234 colds treated with placebo and 14 (5.8%) of 241 colds treated with the study drug were followed by otitis. The decongestant-antihistamine mixture was not useful in preventing development of otitis media in children with colds.

Brompheniramine↗
PubMed1976

A decrease in cell-mediated immunity in uremia associated with an increase in activity of suppressor cells.

The graft-versus-host (GVH) reactivity of uremic and control spleen cells was studied by popliteal lymph node assay in the rat. The reaction evoked by cells from animals with severe uremia was conspicuously weaker than that evoked by control cells. The magnitude of the GVH reaction induced by control cells was directly proportional to dose, while with the uremic cells the same increases in dose led only to insignificant increases in the strength of the GVH reaction. When mixtures of syngeneic control and uremic cells were used, the GVH reactivity of the control cells was suppressed. The activity of uremic spleen cells can be enhanced (restored) by removal of the sub-population of cells adherent to glass wool. The GVH reaction induced by uremic cells so treated became directly proportional to dose. The removal of the adherent cell population from the uremic spleen cell suspension also led to the disappearance of the suppressor effect in mixtures of control and uremic cells. These results indicate that a decrease in GVH activity of rat uremic spleen cells is due to an increase in suppressor cell activity in the uremic spleen cell population.

Animals↗
PubMed1977

[Effects of a coffee-antacid-mixture and a commercial coffee with regard to gastrin, pH and gastric secretion (author's transl)].

The influence of a coffee-antazid-mixture was investigated at 30 patients with diseases of the stomach (17 with duodenal ulcer, 6 with gastric ulcer and 7 with chronic gastritis) in comparison to a commercial coffee. The parameters measured were the gastric basal acid output, the continuous registration of the pH by an intragastric electrode and the serum gastrin concentration before and after the application of the tests substances. 75% of the patients with duodenal ulcer showed a positive effect by means of a greater elevation of the intragastric pH after application of the mixture in comparison to coffee. The effect was strongly correlated to the basal acid ouptput. In the group with gastric ulcer and that with duodenal ulcer under the influence of the mixture the pH after the initial rise decreased to less deeper values. There was a close relationship to the patterns of gastric ulcer as well with chronic gastritis there was an additional facourable effect on the symptoms of abdominal pain which occured after coffee and not after the mixture. The group with chronic gastritis showed no difference between the pure coffee and the coffee-antacid-mixture. A possible relationship of the products of coffee roasting and the adsorptive properties of the antacid is discussed.

Adult↗
PubMed1977

Peroxidase and pseudoperoxidase reactions in relation to sudanophilia.

A selective staining of hemoglobin in erythroid cell series was achieved by use of Sudan Black B (modified method of Sheehan and Storey) if optimal amount of hydrogen peroxide was added to the staining mixture. The effect of some inhibitory agents (KCN, wet heat, pH) on this staining as well as on the Lepehne's pseudoperoxidase reaction for hemoglobin was similar. Both reactions were more resistant to these factors than the peroxidase reactions and sudanophilia in granulocytes in which both could be blocked by the pretreatment with absolute methanol. Moreover the effect of some extraction procedures for lipids on both myeloperoxidase reactions and sudanophilia was investigated. The results support the view that the sudanophilia in granulocytes is due to their peroxidase activity and for the staining of hemoglobin by use of Sudan Black B with H2O2 its pseudoperoxidase activity is responsible. In addition the effect of the substitution of phenolphosphate by dihydroxybenzenes on granulocyte sudanophilia is reported.

Cyanides↗
PubMed1979

Mutagenicity of plant flavonols in the Salmonella/mammalian microsome test: activation of flavonol glycosides by mixed glycosidases from rat cecal bacteria and other sources.

Over 70 naturally occurring and synthetic flavonoids were screened for mutagenicity with 5 tester strains in the Salmonella/mammalian microsome assay: TA1535, TA100, TA1537, TA1538 and TA98. Frameshift mutagenicity was confined to the flavonols (flavon-3-ols) in strain TA98, TA1537 and TA100. The two most mutagenic falvonols, namely, quercetin (3,3',4',5,7-pentahydroxyflavone) and kaempferol (3,4',5,7-tetrahydroxyflavone), exhibiting 12 and 7 revertants/nmol in TA98 respectively, are also the most common flavonols occurring in plants. Other flavonols exhibited less activity (revertants/nmol): galangin (2.0), rhamnetin (0.45), kaempferide (0.24), fisetin (0.14), myricetin (0.12), robinetin (0.06) and morin (0.05). All of these flavonols apparently exhibited significant activation by Aroclor 1254 induced rat-liver microsome preparations (S9). However, subsequent study revealed that only those flavonols either lacking or possessing one B ring hydroxyl group had an absolute requirement for microsomal activation. Alternatively, quercetin with two B-ring OH groups is not activated by microsomal enzymes, but by soluble (S100) enzymes from liver which are apparently constitutive and not subject to the usual chemical induction. 3 flavonol glycosides, namely, quercetrin (quercetin-3-O-rhamnoside), rutin (quercetin-3-O-rutinoside) and robinin (kaempferol-3-O-galactosido-rhamnoside-7-O-rhamnoside), were found to be nonmutagenic. They could, however, be activated by a variety of mixed glycosidases incorporated in the usual pour plate procedure. The most effective enzyme mixtures were obtained from rat cecal bacteria and from the snail Helix pomatia.

Animals↗
PubMed1975

The effects of a polychlorinated biphenyl mixture (Aroclor 1254) on liver gluconeogenic enzymes of normal and alloxan-diabetic rats.

Normal and alloxan-diabetic rats were fed ground Purina Laboratory Chow with or without 500 ppm of Aroclor 1254 (AR) ad lib for 2 weeks. In both normal and diabetic rats, AR administration decreased food consumption, weight gain and blood glucose concentration, and increased liver weight, liver:body weight ratio, total liver lipid, liver protein and malic enzyme (ME) activity. In the normal rat, AR increased the concentrations of acetoacetate and beta-hydroxybutyrate in blood, but in the diabetic rat the concentrations were markedly reduced. AR administration decreased the activity of phosphoenolpyruvate carboxykinase (PEPck) in normal liver and the activities of pyruvate carboxylase (PC), PEPck and glucose-6-phosphatase (G6Pase) in diabetic liver.

Acetoacetates↗
PubMed1977

Chemical interactions between thiamin and tannic acid. II. Separation of products.

Bio Rex 70 column chromatography and high voltage paper electrophoresis were used to fractionate and define the reaction products of thiamin-tannic acid and thiamin-tea mixtures. Fractions separated indicated the presence of (a) thiamin-tannic acid adduct(s) and several modified forms of thiamin among the products. Using radioactive thiamin and determining the intact form by scintillation counting, the extent of thiamin modification under various conditions was compared with previous results as determined by the thiochrome method. The elution profile of the thiamin-tea mixture and the electrophoretogram showed features similar to those of the thiamin-tannic acid mixture. The effectiveness of the tea extract and tannic acid in modifying thiamin was compared. Ascorbic acid was found to protect the modification of thiamin by tannic acid, not only at acidic pH as previously found, but also at neutral pH, thus making vitamin C a strong candidate for the protection of thiamin in the alimentary system.

Antimetabolites↗
PubMed1977

The Bain circuit. Prevention of anaesthetic mixture dilution when using mechanical ventilators delivering non-anaesthetic gases.

Experiments using a lung performance analyser demonstrate that if a 1 m length of corrugated 22 mm diameter anaesthetic breathing how (volume 530 ml) is interposed between a lung ventilator delivering air, and the Penlon Bain-type co-axial anaesthetic circuit and valve (volume 660 ml), air-dilution of the respired gas mixture is effectively prevented under conditions likely to be used in clinical practice.

Anesthetics↗