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PubMed1983

Intravenous albumin administration in acid aspiration syndrome in rabbits.

The possible value of albumin in a rabbit model of the acid aspiration syndrome was studied. Hydrochloric acid was instilled into the respiratory tracts of three groups of rabbits: Group A received a high intravenous dose of human albumin (1.5 gm/kg body weight); Group B (control) was given Hartmann's solution, and Group C a low dose of albumin (0.25 gm/kg body weight). The total amount of intravenous fluids was identical in all groups. Serum and pulmonary edema fluid (PEF) concentrations of total protein were highest in Group A. Simultaneous concentration gradients between serum and PEF for total protein, human and rabbit albumin, and globulin fractions were not statistically different in the three groups. In Group A, PEF appeared first and PaO2, static compliance, and hematocrit decreased significantly more than those of the two other groups. Survival of animals in Group C was highest. An additional Group (D) of rabbits received the same high dose of albumin without acid aspiration. In Group D hematocrit decreased while serum total protein and pulmonary function remained unchanged. It seems that a high dose of albumin causes a further deterioration of lung function following acid aspiration because of extravasation into the interstitial space. The administration of low doses of albumin was not different than Hartmann's solution, but led to the best survival in our model.

Animals↗
PubMed1998

Reactions of 1-methyl-2-phenylindole with malondialdehyde and 4-hydroxyalkenals. Analytical applications to a colorimetric assay of lipid peroxidation.

Under acidic and mild-temperature conditions, 1-methyl-2-phenylindole was found to react with malondialdehyde (MDA) and 4-hydroxyalkenals to yield a stable chromophore with intense maximal absorbance at 586 nm. The use of methanesulfonic acid results in optimal yields of chromophore produced from MDA as well as from 4-hydroxynonenal. By contrast, the use of hydrochloric acid results in an optimal yield of chromophore produced from MDA and a negligible reaction of 4-hydroxynonenal. Taking advantage of such chromogenic reactions, we developed a new colorimetric assay of lipid peroxidation. Using a methanesulfonic acid-based medium, MDA and 4-hydroxyalkenals can be measured at the 586 nm wavelength. However, the presence of endogenous inhibitors of the reaction with 4-hydroxyalkenals is common, and this means that the latter may be underestimated in some biological samples. The assay performed in a hydrochloric acid-based medium enables the specific measurement of MDA in the presence of 4-hydroxyalkenals. Upon hydrolysis of Schiff bases in hydrochloric acid (pH 1.5), either assay can be used to specifically measure the amount of total MDA in biological samples because 4-hydroxyalkenals undergo an irreversible cyclization reaction under the hydrochloric acid-based conditions of hydrolysis. The two assays were applied to the determination of the amount of MDA alone and of MDA and 4-hydroxyalkenals in an in vitro model of lipid peroxidation. This methodology was also used to clarify complex patterns of tissue-specific MDA production in vivo, following hydrolysis of Schiff bases, in rodents treated with doxorubicin.

Aldehydes↗
PubMed1978

Synthetic and endogenous testosterone conjugates: acid hydrolysis studied by radioimmunoassay.

The acid hydrolysis of synthetic testosterone sulphate and glucuronide by sulphuric acid has been studied by measuring the release of uncojugated testosterone by radioimmunoassay. The sulphate was hydrolyzed at lower concentration of acid but no conditions were found where only the sulphate was completely hydrolyzed without any hydrolysis of the glucuronide. Results of similar studies on human urine, however, suggested that human urine contains three conjugates of testosterone and 5 alpha-dihydrotestosterone: the sulphate and glucuronide and also a very acid labile conjugate hitherto unknown. Hydrochloric acid has stronger hydrolyzing effect at the same normality and released more unconjugated testosterone in urine at the same pH than did sulphuric acid. A complete hydrolysis of urinary conjugates in 3 molar sulphuric acid was accomplished without destruction of immunoassayable testosterone and constitutes a suitable method for the determination of the total testosterone content in urine. The method was compared with other hydrolyzing methods by measuring the testosterone release from urinary conjugates after their extraction and separation by by thin-layer chromatography.

Adult↗
PubMed1975

GLC determination of phendimetrazine in serum.

A sensitive, specific, and quantitative GLC method for the determination of phendimetrazine in serum is described. The procedure involves the addition of an internal standard to serum samples, followed by extraction at pH 13 into toluene. The extracted bases are back-extracted into 1 ml of 4 M hydrochloric acid and again into 100 mu1 of chloroform after making the 4 M hydrochloric acid extract basic with 1.5 ml of 4 M sodium hydroxide. The sensitivity of the method is such that 25 ng of material can be detected in 5 ml of serum.

Chromatography, Gas↗
PubMed1996

Influence of pH on the release of propranolol hydrochloride from matrices containing hydroxypropylmethylcellulose K4M and carbopol 974.

The dissolution of propranolol hydrochloride from matrices containing hydroxypropylmethylcellulose K4M (HPMC K4M) and carbopol 974 has been investigated using 0.1 M hydrochloric acid or phosphate buffer at pH 4.5 or pH 7.5. In 0.1 M hydrochloric acid, HPMC K4M predominantly controlled release since carbopol has a low solubility at this pH. As the pH increased, the carbopol became increasingly ionized and interacted with propranolol hydrochloride to form an insoluble complex which retarded the release of the drug. In addition, the nature of the interaction between carbopol 974 and HPMC K4M altered. DSC and viscometric studies indicated that the two polymers contributed synergistically to the gel network at pH 7.5. Thus at pH 7.5 polymers contributed to matrix integrity and to the control of drug release.

Acrylic Resins↗
PubMed1992

Intestinal acid inhibits gastric acid secretion by neural and hormonal mechanisms in rats.

To determine the relative contributions of neural reflexes and intestinal hormones to the inhibition of gastric acid secretion by intestinal acidification, rats with an extrinsically denervated, transplanted segment of jejunum, and those with an innervated segment of jejunum, were studied. Postoperatively, meal-stimulated gastric acid secretion was measured. When the acid secretory response to intragastric liver extract reached a plateau, graded concentrations of hydrochloric acid or saline were instilled into the jejunal segments. Gastric acid secretion was inhibited by intrajejunal acid (pH 2.5) by 79% in the innervated rats and by 64% in the transplanted group. Thus at a pH of 2.5 there was a 15% greater maximum inhibition of plateau acid response in the innervated rats than in the transplanted rats, presumably because of the extrinsic neural contribution. To examine the hormonal mediators, the effects of a somatostatin monoclonal antibody and a CCK-A receptor antagonist (L 364718) on acid-induced inhibition of gastric acid secretion were studied in transplanted rats. Treatment with a somatostatin monoclonal antibody or with L 364718 reduced the acid-induced (pH 2.5) inhibition of gastric acid secretion by 93 and 27%, respectively. Jejunal acidification inhibits gastric acid secretion in the rat by both neural and hormonal mechanisms. The hormonal mechanism is mediated by somatostatin and CCK.

Acids↗
PubMed2006

[Effects of lateral position and independent lung ventilation on unilateral acute lung injury in dogs].

OBJECTIVE: To investigate the effects of conventional ventilation, lateral position, asynchronous independent lung ventilation and synchronous independent lung ventilation on gas exchange, lung mechanics, hemodynamics, pulmonary perfusion and inflammatory mediators in dogs with a hydrochloric acid induced unilateral acute lung injury (ALI). METHODS: Twenty-eight dogs with hydrochloric acid induced unilateral ALI (the left lung) were ventilated with volume controlled ventilation. The animals were divided into four groups. The first group (group A, n = 7) received conventional ventilation in a supine position. The second group (group B, n = 7) received conventional ventilation in the healthy lung dependent position with the parameters as same as group A. The third group (group C, n = 7) received asynchronous independent lung ventilation. The fourth group (group D, n = 7) received synchronous independent lung ventilation with the parameters as same as group C. All the animals were observed for 4 h under the above described ventilation. Oxygenation, lung mechanics, hemodynamics and lung injury score were measured during the ventilation. The right and left pulmonary arterial blood flows were measured after 4 h ventilation. RESULTS: (1) After 30 min ventilation, PaO2/FiO2 in group A [(180 +/- 25) mm Hg, 1 mm Hg = 0.133 kPa] was significantly lower than those in group B, group C and group D [(277 +/- 23), (296 +/- 31), (299 +/- 22) mm Hg respectively, all P < 0.01]. PaO2/FiO2 in group C [(348 +/- 34) mm Hg] and group D [(343 +/- 29) mm Hg] was significantly increased when compared with that of group B [(314 +/- 33) mm Hg] after 60 min ventilation (P < 0.05), but there was no significant difference between group C and group D. (2) After 120 min ventilation, C(st) in group B [(23 +/- 4) ml/cm H2O] significantly increased when compared with that of group A [(19 +/- 2) ml/cm H2O, P < 0.05]. After 60 min ventilation, C(st)-L in group C and group D increased significantly as compared to the beginning of the ventilation. (3) The left lung pulmonary arterial flow in group B, group C and group D [(31.3 +/- 4.6)%, (27.5 +/- 1.3)% and (27.3 +/- 2.8)%, respectively] significantly decreased when compared with that of group A (38.3 +/- 2.2)% after 4 h ventilation (P < 0.05 and P < 0.01). CONCLUSIONS: Both lateral position and independent lung ventilation can improve gas exchange, while independent lung ventilation is better than lateral position ventilation. The improvement of oxygenation may be related to the effect on the distribution of pulmonary arterial flow.

Acute Lung Injury↗
PubMed1994

The availability "in vitro" of magnesium formulations using various leaching media.

The aim of this study was to determine the availability "in vitro" of magnesium ions from five tablet formulations. In our experiment the flow-through method according to Grzesiczak was used. The leaching media in above method were: an aqueous solution of hydrochloric acid at pH 1.0 used as artificial stomach fluid, an aqueous solution of hydrochloric acid at pH 4.0 and physiological salt solution.

Chemistry, Pharmaceutical↗
PubMed2003

Simultaneous determination of Cd(II), Cu(II), Pb(II), and Zn(II) in citrus essential oils by derivative potentiometric stripping analysis.

Citrus essential oils are widely used in the food, cosmetics, and pharmaceutical industries, so the determination of heavy metals content is of great importance to guarantee their quality. The present work deals with the quantification of Cd(II), Cu(II), Pb(II), and Zn(II) in different varieties of citrus essential oils, using derivative potentiometric stripping analysis. Two different metals extraction procedures, involving concentrated hydrochloric acid treatment and acid-alcoholic dissolution, are tested on lemon, mandarin, sweet orange, and bergamot essential oils, and they give very similar results. Cd(II), Cu(II), Pb(II), and Zn(II) recovery tests spanned from 95 to 100.50%, providing evidence that metals quantification remained unaffected by the cleanup steps of the two procedures. The repeatability of the hydrochloric acid extraction method, applied on different varieties of essential oils, is >95.00% for Cd(II), Cu(II), Pb(II), and Zn(II), whereas the repeatability of the acid-alcoholic dissolution method is >93.00% for Cu and Cd only in lemon oil. Detection limits obtained for the four analytes, using both procedures, ranged from 0.10 to 0.98 ng g(-)(1) in lemon, mandarin, sweet orange, and bergamot essential oils.

Cadmium↗
PubMed1980

Effect of duodenal acidification on the lower esophageal sphincter pressure in the dog with special reference to related gastrointestinal hormones.

The role of the duodenum in the regulation of the lower esophageal sphincter pressure was studied in 3 anesthetized dogs with a duodenal fistula by relating the lower esophageal sphincter pressure with plasma gastrin and secretin level during intraduodenal acid infusion test. Instillation of hydrochloric acid into the duodenum produced an initial fall followed by a significant and sustained increase of the lower esophageal sphincter pressure. The initial fall of the lower esophageal sphincter pressure was found to correspond to a prompt but transient rise of plasma secretin concentration, while plasma gastrin did not change significantly throughout the experimental period. It is concluded that duodenum may be an important regulator of the lower esophageal sphincter pressure in the dog through secretin and other unknown factors.

Animals↗
PubMed2003

Solubilization of cobalt from ocean nodules at neutral pH-a novel bioprocess.

A marine organism ( Bacillus M1) isolated from Indian Ocean manganese nodules was characterized. The organism grew well in artificial seawater medium, at near neutral pH, 30 degrees C and 0.25 M NaCl, and showed MnO(2)-reducing activity. Growing cultures of Bacillus M1 as well as cell-free spent liquor from fully-grown cultures were employed to extract metals from the nodules. The spent liquor of cultures of the organism could dissolve around 45% cobalt (Co) at a pH of 8.2 in 2 h. Co recovery by this treatment was comparable to that in acidic leaching with 2.5 M hydrochloric acid solutions, and was independent of pulp density (w/v ratio). The amount of Co dissolved was beyond the thermodynamic solubility limit in aqueous solution at a pH of 8.2. It is inferred that the metabolites present in the spent liquor played a pivotal role in complexing the Fe (III) phase, solubilizing Co in the process. Partial characterization of spent liquor by spot tests, UV visible spectroscopy and FTIR spectroscopy, showed the presence of siderophore-like phenolic compound(s) with an attached carboxyl group that might form soluble organic complexes with Fe (III).

Bacillus↗
PubMed1987

Impaired proximal duodenal mucosal bicarbonate secretion in patients with duodenal ulcer.

The defensive factors that prevent the human duodenal mucosa from acidic and peptic damage have not been fully evaluated. To determine whether duodenal mucosal bicarbonate production was altered in patients with inactive duodenal ulcer, we measured basal and acid-stimulated bicarbonate output from the duodenal bulb and the distal duodenum in healthy subjects and patients with inactive duodenal ulcer. As compared with 16 normal subjects, the 12 patients had significantly less mean (+/- SE) basal proximal duodenal mucosal bicarbonate secretion (185 +/- 13 vs. 107 +/- 18 mumol per centimeter per hour; P less than 0.001). Moreover, in response to a physiologic amount of hydrochloric acid (2 mmol per five minutes) instilled directly into the duodenal bulb, peak proximal duodenal bicarbonate output in the patients was 41 percent of the normal response (263 +/- 65 vs. 642 +/- 77 mumol per centimeter per hour; P less than 0.01). There was little overlap between groups. In contrast, bicarbonate outputs in the distal duodenum were similar in the two groups. We conclude that most patients with duodenal ulcer disease have decreased proximal duodenal mucosal bicarbonate production at rest, in response to hydrochloric acid, and in relation to peak gastric acid secretion. Impaired proximal duodenal mucosal bicarbonate secretion may be an important factor in the development and natural history of duodenal ulcer.

Adult↗
PubMed1978

[The lipids of the lungs in experimental aspiration pneumonitis (author's transl)].

In the lungs of LEWE-Mini-Pigs with aspiration pneumonitis, which was produced by intratracheal application of 0,2 n hydrochloric acid, the following parameters were determined post-mortally: Total phospholipid-, water- and cholesterol content and sphingomyelin-, lecithin-, phosphatidylethanolamine- and phosphatidylserine concentration. Furthermore thin-layer- and gelchromatographic investigations were performed. The water- and the cholesterol content are increased (about 4 respectively 40 percent). The total phospholipid- and the lecithin content are decreased (about 10 respectively 30 percent). The lysolecithin concentration is very low in the lungs. By therapy with bromhexine metabolite VII the water- and cholesterol content are reduced, the total phospholipid- and lecithin content are increased in comparison to the lungs without therapy. In this case the total phospholipid- and lecithin content are raised in the liver simultaneously. The biochemical changes are caused probably by a disorder of the surfactant system of the lung (disturbance of phospholipid-protein-interaction) and impairment of the alveolar epithelial cells typ II (decreased lecithin biosynthesis) in consequence of the action of the hydrochloric acid.

Ambroxol↗
PubMed1975

Antigenic analyses of Lactobacillus fermenti.

Antigenic analyses of Lactobacillus fermenti were carried out by double immunodiffusion in agar using extracts prepared with cold trichloroacetic acid (TCA) or hot dilute hydrochloric acid (HCL). A common antigen of L. fermenti, designated as antigen f by the author, was extracted from whole cells with dilute HCL, but not with TCA. The antigen f was also observed in Lactobacillus casei. In addition, all strains isolated from human saliva contained antigen 6 in their cell walls, while the antigen was not observed in most of the isolates from human feces. Therefore, L. fermenti could be divided into two subgroups based upon the existence of antigen 6. Antigen 7 which was demonstrated in some strains of L. fementi was shared by other species of lactobacilli belonging to the serological groups D and E. The common antigen 3 found in lactobacilli was extracted from all strains of L. fermenti Sugar components of cell walls were mainly galactose, glucose and glucosamine (including N-acetylglucosamine), but a small amount of rhamnose was present in the cell wall of only one strain. Inhibition tests with various sugars showed that the serologically active sugars were galactose for antigen f and glucose for antigen 6.

Antibodies, Bacterial↗
PubMed1969

Micro determination of plasma and erythrocyte copper by atomic absorption spectrophotometry.

The free and total plasma copper and total erythrocyte copper levels have been determined by simple, yet sensitive and highly specific methods, using atomic absorption spectrophotometry. For total copper determination, the copper was split from its protein combination in plasma or red cells by the action of hydrochloric acid at room temperature. The liberated copper was chelated by ammonium pyrrolidine dithiocarbamate and extracted into n-butyl acetate by shaking and the organic extract was aspirated into the atomic absorption spectrophotometer flame. The entire procedure was carried out in polypropylene centrifuge tubes, capped during shaking. For the free plasma copper measurement the hydrochloric acid step was omitted. Removal of the plasma or erythrocyte proteins was found to be unnecessary, and, in addition, the presence of trichloracetic acid caused an appreciable lowering of absorption. Using a double-beam atomic absorption spectrophotometer and scale expansion x 10, micro methods have been derived for determining the total copper of plasma or erythrocytes with 0.1 ml of sample, and the free copper of plasma with 0.5 ml. The macro plasma copper method requires 2 ml of plasma and is suitable for use with single-beam atomic absorption spectrophotometers. With blood from 50 blood donors, normal ranges of plasma and erythrocyte copper have been determined.

Blood Proteins↗
PubMed2002

A decontamination process to remove metals and stabilise Montreal sewage sludge.

The Montreal Urban Community (MUC) treatment plant produces approximately 270 tons of dry sludge daily (tds/day) during physicochemical wastewater treatment. The sludges are burned and contribute to the greenhouse effect by producing atmospheric CO2. Moreover, the sludge emanates a nauseating odour during its thermal stabilisation and retains unpleasant odours for the part (25%) that is dried and granulated. To solve this particular problem, the treatment plant authorities are currently evaluating an acidic chemical leaching (sulfuric or hydrochloric acid) process at a pH between 2 and 3, using an oxidizing agent such as ferric chloride or hydrogen peroxide (METIX-AC technology, patent pending; [20]). They could integrate it to a 70 tds/day granulated sludge production process. Verification of the application of METIX-AC technology was carried out in a pilot plant set up near the sludge production plant of the MUC. The tests showed that METIX-AC technology can be advantageously integrated to the process used at the MUC. The residual copper (274 +/- 58 mg/kg) and cadmium (5.6 +/- 2.9 mg/kg) concentrations in the treated sludge meet legislation standards. The results have also shown that odours have been significantly eliminated for the dewatered, decontaminated, and stabilized biosolids (> 97%) compared to the non-decontaminated biosolids. A high rate of odour elimination also was obtained for the liquid leached biosolids (> 93%), compared to the untreated liquid biosolids. The fertilising value (N and P) is well preserved by the METIX-AC process. Dissolved organic carbon measurements have showed that little organic matter is brought in solution during the treatment. In fact, the average concentration of dissolved organic carbon measured in the treated liquid phase is 966 +/- 352 mg/l, whereas it is 1190 +/- 325 mg/l in untreated sludge. The treated sludge was first conditioned with an organic polymer and a coagulant aid. It was successfully dewatered with various dehydration equipments (filter press, rotary press, centrifuge).

Canada↗
PubMed1981

Ammonia partitioning between glutamine and urea: interorgan participation in metabolic acidosis.

The distribution of precursor nitrogen between urea and glutamine was studied in control and acidotic rats. Acidosis, either acutely induced with hydrochloric acid or chronically induced with ammonium chloride, resulted in a rise in ammonia and a fall in urinary urea excretion; the percent of urinary nitrogen excreted as ammonia rose from 3.5 +/- 0.4 and 4.9 +/- 0.5 in fed and pair-fed controls to 25.9 +/- 3.9 and 37 +/- 5 in acidosis induced by hydrochloric acid and ammonium chloride. Hepatoportal vein urea concentration differences were significantly reduced, whereas glutamine concentration differences were significantly elevated, consistent with a shift of nitrogen from ureagenesis to glutamine; alanine and ammonia concentration differences were significantly decreased and increased respectively in the acidotic animals, suggesting that former supported urea synthesis whereas ammonia may preferentially support glutamine synthesis. Evidence of a feed-forward involvement of the gut in influencing hepatic nitrogen distribution was suggested by an increased ammonia and decreased alanine release in acidotic rats. Bilateral ureteral ligation was performed on control and acidotic rats to determine the fate of the redirected urinary ammonia. Ammonia did not accumulate in the blood, rather it was initially incorporated into glutamine, elevating the plasma level, and then it was subsequently deposited into urea. The shift of nitrogen back into urea in acidotic animals was confirmed by the greater postligation urea production rates supported by hepatic uptake of both alanine and glutamine. These results are discussed in terms of interorgan participation involving the liver, gut, and muscle in the partitioning of nitrogen between glutamine and urea.

Acidosis, Renal Tubular↗
PubMed2005

Surfactant alterations in acute inflammatory lung injury from aspiration of acid and gastric particulates.

This study examines surfactant dysfunction in rats with inflammatory lung injury from intratracheal instillation of hydrochloric acid (ACID, pH 1.25), small nonacidified gastric particles (SNAP), or combined acid and small gastric particles (CASP). Rats given CASP had the most severe lung injury at 6, 24, and 48 h based on decreases in arterial oxygenation and increases in erythrocytes, total leukocytes, neutrophils, total protein, and albumin in bronchoalveolar lavage (BAL). The content of large surfactant aggregates in BAL was reduced in all forms of aspiration injury, but decreases were greatest in rats given CASP. Large aggregates from aspiration-injured rats also had decreased levels of phosphatidylcholine (PC) and increased levels of lyso-PC and total protein compared with saline controls (abnormalities for CASP were greater than for SNAP or ACID alone). The surface tension-lowering ability of large surfactant aggregates on a bubble surfactometer was impaired in rats with aspiration injury at 6, 24, and 48 h, with the largest activity reductions found in animals given CASP. There were strong statistical correlations between surfactant dysfunction (increased minimum surface tension and reduced large aggregate content) and the severity of lung injury based on arterial oxygenation and levels of albumin, protein, and erythrocytes in BAL (P < 0.0001). Surfactant dysfunction also correlated strongly with reduced lung volumes during inflation and deflation (P = 0.0004-0.005). These results indicate that surfactant abnormalities are functionally important in gastric aspiration lung injury and contribute significantly to the increased severity of injury found in CASP compared with ACID or SNAP alone.

Acute Disease↗