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At least 1,135 records · Page 63Linked to original sources
PubMed1977

[Peptic anastomotic ulcer induced by continuous duodenogastrix reflux (author's transl)].

Different types of duodenal by-pass operations with and without duodenogastric reflux were performed on 54 male Wistar rats. The results of our investigation show that following duodenal by-pass with reflux peptic anastomotic ulcer regularly occurs. The constant reflux of bile and pancreas juice is the most important aetiologic factor in the development of ulcer in the vicinity of the anastomosis between the stomach and small intestine. Stasis in the by-passed duodenum (afferent loop syndrome) promotes ulcerogenic action of reflux. In the absence of the pylorus the effects of reflux ans stasis potentiate, resulting in a high frequency of ulcer (greater than 90%). With intact pylorus the incidence is low. Duodenogastric reflux prevents hydrochloric acid secretion significantly (P less than 0.01); hydrochloric acid thus plays a minor role in the development of experimental anastomotic ulcer of the rat. -In considering the prophylaxis against anastomotic ulcer, there findings support the claim of avoiding surgical techniques involving duodenal by-pass and reflux (Billroth II with short loop GE). Gastric resection should, therefore, aim at the reconstruction of the orthograde peristalsis.

Animals↗
PubMed1981

Corrosion of Co-Cr alloys in aqueous environments.

The literature relating to the corrosion in aqueous media of the Co-Cr alloys is reviewed. Data are surveyed for their corrosion in sulphuric acid, alkalis and in hydrochloric acid and chloride media. In the latter category, the information is sub-divided into single corrosion, crevice and stress corrosion, fretting corrosion and data obtained from 'in vivo' experiments. It is clear that the very low current densities which result from 'in vitro' experiments present abnormal experimental problems and may not, in every case, actually represent the dissolution process.

Acids↗
PubMedDate not supplied

[Effects of toxic substances on opportunistic microorganisms].

Anti-immunoglobulin activity of immunoglobulins, rarely receiving attention in literature, occupies a special place among the special bacterial substances released by bacteria exocellularly. We studied the effects of some pollutants (phenol, diethanolamine, nitric and hydrochloric acids) on this pathogenicity factor. Phenol and hydrochloric acid added to tap water caused statistically significant changes in anti-immunoglobulin activity of Klebsiella strains.

Disinfectants↗
PubMed1969

The adenosine triphosphate inhibition of the pyruvate kinase reaction and its dependence on the total magnesium ion concentration.

1. The effects of ATP, PP(i) and EDTA on the skeletal-muscle pyruvate kinase reaction at various concentrations of magnesium (where ;magnesium' refers to total Mg(2+), both free and in the form of complexes) were investigated. The reaction rate was determined as the amount of pyruvate formed in a recorded time of incubation. 2. At 44mm-magnesium the K(m) values for ADP and phosphoenolpyruvate were unaltered by the presence of ATP up to 6.8mm in systems buffered with either tris-hydrochloric acid or glycylglycine-sodium hydroxide, but the K(m) values were different in these systems. The K(m) for one substrate was independent of the concentration of the second substrate. 3. At 10mm-magnesium in the tris-hydrochloric acid system ATP inhibited the reaction competitively with respect to ADP and phosphoenolpyruvate. In the glycylglycine-sodium hydroxide system the inhibition appeared to be non-competitive. At 10mm-magnesium the K(m) values were lower than at 44mm-magnesium and dependent on the system used. 4. In the tris-hydrochloric acid system the reaction rate rose with increasing magnesium concentration up to a maximum at a concentration 10-20 times that of ADP. Further increase inhibited the reaction and at 44mm-magnesium the rate was 25-50% of its maximum. This inhibition paralleled that produced by increasing trimethylammonium chloride concentrations and was not due to a specific effect of the Mg(2+) ion. 5. In the presence of 6.8mm-ATP no reaction occurred below 4-6mm-magnesium, and further increase apparently abolished the inhibition as the reaction rate increased and became equal to those obtained in the absence of ATP at 10-25mm-magnesium. Further increase in magnesium concentration gave reaction rates that were slightly higher in the presence of ATP than in its absence. The maximal rate in the presence of ATP was distinctly lower than in its absence. When 6.8mm-PP(i) or 6.8mm-EDTA was present the variations in reaction rate with rising magnesium concentration were similar to that obtained in the presence of ATP below 6-8mm-magnesium but further increase in the magnesium concentration resulted in an increase in the rate up to a maximum comparable with that of the control. The effect of pure chelation was thus a displacement of the reaction maximum to higher magnesium concentrations without changing the maximal rate. When correction had been made for this effect, ATP gave inhibition at 44mm-magnesium that was competitive with respect to ADP (K(i) 2.1x10(-2)m). This degree of inhibition is far less than was reported earlier and its importance for the mechanism of the pyruvate kinase reaction is discussed.

Adenine Nucleotides↗
PubMed2002

Effect of preparatory conditions on the performance of photopolymerized sol-gel monoliths for capillary electrochromatography.

We prepared different photopolymerized sol-gel (PSG) columns by varying the amount of monomer (methacryloxypropyltrimethoxysilane), porogen (toluene) and catalyst (hydrochloric acid) in the reaction solution containing a photoinitiator (Irgacure 1800). The effects of these variations on the chromatographic behavior of the PSG columns were studied. All of the columns studied exhibited reversed-phase character. The concentration of hydrochloric acid was important for the rigidity of the columns, although it did not affect the separation property. The ratio of monomer solution to porogen was a critical factor in controlling the through-pore size and the surface area of PSG, which were found to significantly affect the separation properties, such as permeability, theoretical plate number, retention time, and separation efficiency, of a mixture of test analytes-thiourea, benzene, and naphthalene. There was no change in the retention order for the test analytes. Short separation times were achieved on PSG columns made from a 10% monomer stock solution and 90% porogen with 1 M hydrochloric acid. Mixtures of polycyclic aromatic hydrocarbons and alkylbenzenes were separated with theoretical plate numbers greater than 100 000 plates/m.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed1996

Water-in-oil emulsion containing oxine for the collection of traces of copper(II) in waterPreliminary stud.

An oil type emulsion containing tiny encapsulated droplets of hydrochloric acid has been used for the concentration of traces of copper(II) ions in water. Milligram quantities of oxine and a non-ionic surfactant (Span-80) were dissolved in 5-10 ml of chloroform and mixed vigorously with 3 ml of 1 mol/l hydrochloric acid by ultrasonic irradiation. The resulting water-in-oil type emulsion was gradually added to 50-500 ml of water sample and dispersed by stirring as numerous small globules (0.1 to 0.5 mm in diameter). The copper diffused through the chloroform layer into the small droplets of hydrochloric acid, which occurred quantitatively in the sample of pH 3-10. After separating the emulsion by sedimentation, it was demulsified by heating to segregate the aqueous and organic phases. The copper in the aqueous phase was successfully determined by GFAAS. The emulsion method allows to perform both extraction and back-extraction more easily and rapidly than the conventional liquid-liquid extraction method.

Journal Article↗
PubMed1992

[The diagnostic value of the histamine test in studying the gastric juice of patients with duodenal peptic ulcer].

Measurements were made of the content of pepsin and hydrochloric acid in gastric juice from 96 duodenal ulcer patients, obtained under the conditions of basal secretion and after histamine administration in the submaximal dose. The disease was marked by changes in the response to histamine on the part of gastric glands. In duodenal ulcer patients, histamine primarily stimulates pepsin secretion whereas in healthy subjects, secretion of hydrochloric acid is predominant. Based on the regularity thus revealed, a new test (the ratio of the histamine index of pepsin to the histamine index of hydrochloric acid) was developed. This test is of importance for the diagnosis of duodenal ulcer and predicting the gravity of the course it may run.

Adolescent↗
PubMed2000

Antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis patients.

The present study examined the antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis (AD) patients. Plasma coagulation by S. aureus cells was not detected in plasma containing acidic hot-spring water (60%, pH 5.4) or hydrochloric acid (pH 5.0) after incubation for 24 h. S. aureus cells did not grow in Mueller-Hinton broth with acidic hot-spring water (50%, pH 4.4) after 24 h incubation. The colony counts of S. aureus cells in tryptic soy broth containing acidic hot-spring water (60%, pH 3.9) were over ten times lower than those in tryptic soy broth alone after incubation for 24 h (P<0.01). A membranous structure (an immature biofilm) was formed on the coverslips of tissue culture dishes by S. aureus cells in plasma after incubation for 24 h, although the colony counts of S. aureus cells in the immature biofilms in plasma containing acidic hot-spring water (60%, pH 5.4) were about eight times lower than those in plasma alone after incubation for 24 h (P<0.01). The colony counts of S. aureus cells that attached on coverslips in plasma containing acidic hot-spring water (60%, pH 5.4) or hydrochloric acid (pH 5.4) were over 1000 times lower than those in plasma alone after incubation for 24 h. These results suggest that 50% acidic hot-spring water has a bacteriostatic effect, 60% acidic hot-spring water has a moderate bactericidal effect against floating S. aureus cells and those cells in a biofilm, and, 60% acidic hot-spring water has an inhibitory effect on plasma coagulation and attachment of S. aureus cells. Furthermore, our present results suggest that a small amount of some ions in hot-spring water such as manganese and iodide ions are very important for a bactericidal activity of hot-spring water as well as the low pH condition.

Acids↗
PubMed1989

Measurements of air pollutants at two disposal sites in Cairo.

40,000 people live on the periphery of Cairo. They dispose of the city's entire waste. A complete recycling of the waste is carried out (up to 90%). The rest is burnt. Enormous fume emissions result form the incomplete burning process of their constituents of rest wastes (plastic, paper rests, tins cloth rests, org. material). The daily burning process lasts from midday to approximately 11 p.m. The main pollutants measured were: Carbon monoxide, hydrochloric acid and sulphur dioxide. As the results demonstrate, high amounts of carbon monoxide and hydrochloric acid are emitted from the burning process.

Air Pollutants↗
PubMed2000

Emergence of resistance to biocides during differentiation of Acanthamoeba castellanii.

A synchronous encystment method was used to study the order of development of resistance of Acanthamoeba castellanii to a range of biocides. The emerging resistance during encystation to short-term exposure to the minimum amoebicidal concentrations of each biocide tested was recorded during the first 36 h of the differentiation process. Hydrochloric acid and moist heat were tested as possible resistance markers. Development of the acid-insoluble, proteincontaining, ectocyst wall and the cellulose endocyst wall was followed by quantification of the acid- and alkali-insoluble residues of cell samples removed from synchronous encystment cultures up to 36 h. Resistance to chemical agents (polyhexamethylene biguanide, benzalkonium chloride, propamidine isethionate, pentamidine isethionate, dibromopropamidine isethionate, hydrogen peroxide) and to moist heat was seen to develop between 14 and 24 h after trophozoites were inoculated into the encystment media. Resistance to hydrochloric acid developed between 0 and 2 h and to chlorhexidine diacetate between 24 and 36 h. Levels of acid-insoluble residues began to increase after 8 h and alkali-insoluble residues (cellulose) were detected after 16 h and coincided with the emergence of resistance to all the agents tested except hydrochloric acid. The results suggest that resistance to the biocides tested probably results largely from the physical barrier of the cyst walls rather than as a consequence of a metabolically dormant cyst.

Acanthamoeba↗
PubMed1985

Role of the endocrine pancreas in the kalemic response to acute metabolic acidosis in conscious dogs.

Metabolic acidosis due to organic acids infusion fails to elicit hyperkalemia. Although plasma potassium levels may rise, the increase is smaller than in mineral acid acidosis. The mechanisms responsible for the different effects of organic acid acidosis and mineral acid acidosis remain undefined, although dissimilar hormonal responses by the pancreas may explain dissimilar hormonal responses by the pancreas may explain the phenomena. To test this hypothesis, beta-hydroxybutyric acid (7 meq/kg) or hydrochloric acid (3 meq/kg) was infused over 30 min into conscious dogs (n = 12) with chronically implanted catheters in the portal, hepatic, and systemic circulation, and flow probes were placed around the portal vein and hepatic artery. Acid infusion studies in two groups of anesthetized dogs were also done to assess the urinary excretion of potassium (n = 14), and to evaluate the effects of acute suppression of renal electrolyte excretion on plasma potassium and on the release/uptake of potassium in peripheral tissues of the hindleg (n = 17). Ketoacid infusion caused hypokalemia and a significant increase in portal vein plasma insulin, from the basal level of 27 +/- 4 microU/ml to a maximum of 84 +/- 22 microU/ml at 10 min, without changes in glucagon levels. By contrast, mineral acid acidosis of similar severity resulted in hyperkalemia and did not increase portal insulin levels but enhanced portal glucagon concentration from control values of 132 +/- 25 pg/ml to 251 +/- 39 pg/ml at 40 min. A significant decrease in plasma glucose levels due to suppression of hepatic release was observed during ketoacid infusion, while no changes were observed with mineral acid infusion. Plasma flows in the portal vein and hepatic artery remained unchanged from control values in both acid infusion studies. Differences in renal potassium excretion were ruled out as determinants of the disparate kalemic responses to organic acid infusion compared with HCl acidosis. Evaluation of the arteriovenous potassium difference across the hindleg during ketoacid infusion demonstrates that peripheral uptake of potassium is unlikely to be responsible for the observed hypokalemia. Although the tissue responsible for the different kalemic responses could not be defined with certainty, the data are compatible with an hepatic role in response to alterations in the portal vein insulin and/or glucagon levels in both acid infusion studies. We propose that cellular uptake of potassium is enhanced by hyperinsulinemia in ketoacid infusion, and release of potassium results from increased glucagon levels in HCl acidosis. Whether the changes in plasma potassium that other types od organic acid acidosis produce are accounted for by a similar hormonal mechanism remains to be determined.

3-Hydroxybutyric Acid↗
PubMed1992

[Duodenal ulcers that do not heal for a long time].

The investigations of 43 duodenal ulcer cases in the patients whose ulcers failed to cicatrize after a 8-week treatment with almagel and vicalin or cimetidine monotherapy revealed the role of the hereditary load, smoking intensity, initial ulcer dimensions, the presence of antral erosions and a pronounced periulcerous duodenitis in the phenomenon of slow healing duodenal ulcer. There was no statistical difference between the values of the basal and pentagastrin-stimulated levels of hydrochloric acid secretion in the morning, partial alkaline gastric secretion, gastrinemia, the rate of evacuation of the gastric contents into the duodenum, the outcome of pancreatic bicarbonates in the sample with exogenic secretin in those whose ulcers cicatrized after a 6-week therapy and those who failed to be cured after being exposed to the same therapy during 8 weeks. The production of hydrochloric acid in the evening and the incidence of manifest duodenal reflux were significantly higher in the patients with slowly healing ulcer. They also had a decreased sensitivity to the intraduodenal inflow of the hydrochloric acid that resulted in the increase of endogenic secretin (stimulating the production of pancreatic bicarbonates and their transport into the duodenum). In case the combination treatment with almagel and vicalin failed, the therapy with gastrocepin or sucralfate was employed. A supplementary course of sucralfate helped to reach a complete healing of noncomplicated ulcers even in the patients in whom the preceding cimetidine treatment failed.

Adult↗
PubMed2002

Acid-labile formylation of amino terminal proline of human immunodeficiency virus type 1 p24(gag) was found by proteomics using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.

HIV-1(LAV-1) particles were collected by ultracentrifugation, treated with subtilisin, and then purified by Sepharose CL-4B column chromatography to remove microvesicles. The lysate of the purified human immunodeficiency virus type 1 (HIV-1) particles was subjected to two-dimensional (2D) gel electrophoresis and stained, and the stained spots were excised and digested with trypsin. The resulting peptide fragments were characterized by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Twenty-five proteins were identified as the proteins inside the virion and the acid-labile formyl group of an amino terminal proline residue of HIV-1(LAV-1) p24(gag) was determined by MALDI-TOF MS before and after weak-acid treatments (0.6 N hydrochloric acid) and confirmed by post-source decay (PSD) of the N-formylated N-terminal tryptic peptide (N-formylated Pro(1)-Arg(18)). The role of formylation has been unclear so far, but it is surmised that the acid-labile formylation of HIV-1(LAV-1) p24(gag) may play a critical role in the formation of the HIV-1 core for conferring HIV-1 infectivity.

Amino Acid Sequence↗
PubMedDate not supplied

Determination of biogenic amines in cheese.

A liquid chromatographic (LC) procedure for determining 10 biogenic amines in cheese is described. The method is based on ion-pair chromatography on a reversed-phase column with postcolumn derivatization with o-phthaldialdehyde and fluorometric detection. It allowed simultaneous determination of 10 amines in < 80 min: histamine, tyramine, tryptamine, 2-phenylethylamine, serotonin, agmatine, spermine, spermidine, putrescine, and cadaverine. Linearity for each amine was observed between 0.5 and 6.0 micrograms/mL. Detection limits ranged form 0.004 to 0.009 micrograms/20 microL, and determination limits ranged from 0.066 to 0.149 mg/100 g. Amino acids and other amines did not interfere with determination of biogenic amines. Three extractants--methanol, hydrochloric acid, and trichloroacetic acid--were compared in their efficiency to recover amines from spiked samples. Purification of the cheese extract was required prior to LC to avoid interference from compounds in the cheese matrix. Hydrochloric acid extraction followed by purification with diethyl ether gave best recoveries for all the amines (75.5-112.3%). The method is simple, fast, and reliable. It can be used to study the technological and toxicological implications of biogenic amines in cheeses.

Biogenic Amines↗
PubMed1961

Ultrastructural cytochemistry. Enzyme and acid hydrolysis of nucleic acids and protein.

Selective extraction of specific cell components by enzyme or acid hydrolysis is possible from ultrathin sections for electron microscopy and parallel 2 micro sections for light microscopy of tissues fixed in formalin and embedded in a water-soluble polyepoxide, product X133/2097. Normal rat tissues fixed 15 minutes in formalin at 3 degrees C are more rapidly digested by proteinases than those fixed for the same length of time at 20 degrees C. Trypsin selectively attacks the nuclear chromatin and the ribonucleoprotein particles of the ergastroplasm, whereas mitochondria and zymogen granules resist tryptic digestion. Pepsin rapidly attacks the mitochondria and zymogen granules. The ergastoplasm and nucleus at first resist peptic digestion, but in time the entire cytoplasm and interchromatinic portion of the nucleus are attacked. Ribonuclease abolishes cytoplasmic basophilia in 2 micro sections, but parallel ultra-thin sections, stained with uranyl acetate and examined in the electron microscope, show no change in the ribonucleoprotein particles of the ergastoplasm. Desoxyribonuclease alone had no effect, but after pretreatment of the sections with pepsin or hydrochloric acid, desoxyribonuclease specifically attacked the nuclear chromatin. Nucleic acid-containing structures in the sections are gradually disintegrated by perchloric acid or hydrochloric acid.

Animals↗
PubMed1985

Staining of different endocrine cells with hydrochloric acid-toluidine blue in Epon embedded rat tissue.

The usual HCl-toluidine blue staining of different endocrine cells is applicable to paraffin embedded material. A modification for Epon embedded tissue suitable for consecutive light and electron microscopic studies is described which makes it possible to find the same stained cell, both in a semithin section and in subsequent ultrathin sections. This method facilitates the search for scattered specific endocrine cells. Without removing the resin, sections of Epon embedded tissues were hydrolyzed for 17 hr in 1% HCl at 65 C and stained for 2 hr in 0.1% toluidine blue in McIlvaine buffer, pH 5.8. The following cells were stained: C cells in thyroid glands; A and D cells in pancreatic islets; B cells in anterior pituitary; G, D and Ec cells in the gastrointestinal tract; Ad cells of the adrenal medulla.

Adrenal Medulla↗
PubMedDate not supplied

In vitro neutralization of the scorpion, Buthus tamulus venom toxicity.

Scorpion (Buthus tamulus) venom was subjected to neutralization by treating the venom with various chemicals such as hydrochloric acid, sodium hydroxide, thiourea, formaldehyde, zinc sulphate, acetic acid and trichloroacetic acid. The venom was also subjected to heat treatment. The levels of total protein, free amino acids and protease activity in neutralized venom decreased significantly. The decrease in venom protein and free amino acids was in proportion to the duration of the heat treatment and the concentration of chemicals used except zinc sulphate, sodium hydroxide and thiourea. Protease activity of neutralized venom samples also showed a decrease except with zinc sulphate which enhanced the enzyme activity. Intramuscular injection of formaldehyde, trichlcroacetic acid and heat treated venoms into albino rats produced low mortality while thiourea and zinc sulphate were not effective in reducing the mortality. Hydrochloric acid and acetic acid treated venoms reduced the mortality by 50% with a decrease in the symptoms of envenomation. The changes were attributed to the denaturing of venom protein by chemical and heat treatments.

Amino Acids↗
PubMed1979

Hydrochloric acid-sodium thiosulphate-Schiff reagent and its cytochemical properties.

Cytochemical properties of modified Schiff reagent, prepared with 5 ml of N HCl and 1.0 g of sodium thiosulphate, the latter replacing potassium metabisulphite, have been presented in this communication. It has been seen that such a modified Schiff reagent has a slightly elevated pH as compared with that of the conventional Schiff reagent. It has also been found that this modified Schiff reagent has a much longer shelf-life and that the staining intensity produced by this dye-reagent is more than those of the usual Schiff reagent prepared with N HCl and potassium metabisulphite (potassium pyrosulphite, K2S2O5). Possible mechanism as to why the staining intensity of the nuclei is more with this modified Schiff reagent as well as the reason as to why its shelf-life is increased compared with those of the conventional Schiff reagent have been discussed.

Animals↗