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PubMed1984

Separation of heparin on Sepharose CL-4B in the presence of high concentrations of ammonium sulphate.

Heparin was fractionated by chromatography on Sepharose CL-4B/3.8-2.0 M ammonium sulphate in 0.01 M hydrochloric acid at 4 degrees C based on a principle different from that of gel filtration--possibly due to multiple interaction mechanisms including those based on hydrophobic bonds. The results of the fractionation were very similar to those of chromatography on Phenyl-Sepharose CL-4B/3.8-2.0 M ammonium sulphate in 0.01 M hydrochloric acid at room temperature. That is, the separation was related to the molecular size distribution, N-acetyl content and anticoagulant activities. As the result of studies on a set of Sepharose 4B gels with different degrees of cross-linking, it has been shown that the introduction of the cross-linked structure, -O-CH2-CH(OH)-CH2-O-, into the gel matrix enhances the interaction between the Sepharose CL-4B gel and heparin, indicating that heparin retention by the highly cross-linked Sepharose 4B gel surpasses that by Phenyl-Sepharose CL-4B.

Ammonium Sulfate↗
PubMed2000

[Preparation and evaluation of polyvinyl pyrrolidone-coated columns based on sol-gel chemistry for capillary electrophoresis].

Polyvinyl pyrrolidone(PVP) coating techniques based on sol-gel chemistry was investigated in this article. Multiple-step coating and single-step coating methods were developed and the coating conditions(molar ratios of MAPS to 0.1 mol/L HCl, reaction times and concentration of PVP) were selected. Electroosmosis mobility and column efficiency were used as the evaluating parameters for coated capillary columns. For multiple-step coating, the optimal sublayer sol solution was obtained by adding 0.1 mol/L hydrochloric acid to MAPS(molar ratio, 1:1) and reacted at room temperature for 2 hours. The best PVP mass concentration was 40 g/L in alcohol. For single-step coating, the sol-gel solution was obtained by mixing the following ingredients: (a)MAPS, (b) 8% PVP alcohol solution and (c) 0.1 mol/L hydrochloric acid in 1:1 molar ratio to MAPS. The mixture was kept at room temperature for 2 hours. Proper amounts of 100 g/L ammonium persulfate and 10% (V/V) N, N, N', N'-tetramethylethylenediamine were then added. The mixture was mixed ultrasonically, then centrifuged at 4,000 r/min for 5 min. The upper clean sol-gel solution was transferred into another clean vial for coating capillary column. The reproducibility of migration times and efficiencies of single-step-coated capillary was better than that of multiple-step-coated capillary. Single-step-coating method was very effective and easy. It can fit the needs in experimental work. Coating techniques based on sol-gel chemistry are prospective but still need to be further developed.

Electrophoresis, Capillary↗
PubMed2005

A stability-indicating HPLC assay for metronidazole benzoate.

A simple and rapid stability-indicating HPLC assay procedure has been developed and validated for metronidazole benzoate. The HPLC conditions were as follows, column: Waters Symmetry C8, 5 microm packing, 4.6 mm x 250 mm; detection: UV at 271 nm; injection volume: 20 microl; mobile phase: acetonitrile-0.1% glacial acetic acid in monobasic potassium phosphate (0.01 M) (40:60, v/v); isocratic elution under ambient temperature at 2.0 ml min(-1). The procedure separated metronidazole benzoate and its potential degradation products, metronidazole and benzoic acid, in an overall analysis time of about 6 min with metronidazole benzoate eluting at about 5 min. The injection repeatability was 0.03%, and the intraday and interday repeatability were 0.4 and 0.7%, respectively. The procedure provided a linear response over the concentration range 0.2-800 microg ml(-1) (r=1.0000) with the limits of detection and quantitation 0.03 and 0.2 microg ml(-1), respectively. The solubilities of metronidazole benzoate in water, 0.01 M hydrochloric acid and 0.05 M phosphate buffer, pH 6.8, determined each in triplicate using the procedure, were 0.2 mg ml(-1) (R.S.D. 7%), 0.4 mg ml(-1) (R.S.D. 2%) and 0.2 mg ml(-1) (R.S.D. 8%), respectively. The results show no detectable hydrolysis of metronidazole benzoate in 0.01 M hydrochloric acid at 37 degrees C or in the mobile phase at ambient temperature in 10 h.

Antitrichomonal Agents↗
PubMed2002

O-4-Linked coniferyl and sinapyl aldehydes in lignifying cell walls are the main targets of the Wiesner (phloroglucinol-HCl) reaction.

The nature and specificity of the Wiesner test (phloroglucinol-HCl reagent) for the aromatic aldehyde fraction contained in lignins is studied. Phloroglucinol reacted in ethanol-hydrochloric acid with coniferyl aldehyde, sinapyl aldehyde, vanillin, and syringaldehyde to yield either pink pigments (in the case of hydroxycinnamyl aldehydes) or red-brown pigments (in the case of hydroxybenzaldehydes). However, coniferyl alcohol, sinapyl alcohol, and highly condensed dehydrogenation polymers derived from these cinnamyl alcohols and aldehydes did not react with phloroglucinol in ethanol-hydrochloric acid. The differences in the reactivity of phloroglucinol with hydroxycinnamyl aldehydes and their dehydrogenation polymers may be explained by the fact that, in the latter, the unsubstituted (alpha,beta-unsaturated) cinnamaldehyde functional group, which is responsible for the dye reaction, is lost due to lateral chain cross-linking reactions involving the beta carbon. Fourier transform infrared spectroscopy and thioacidolysis analyses of phloroglucinol-positive lignifying plant cell walls belonging to the plant species Zinnia elegans L., Capsicum annuumvar. annuum, Populus albaL., and Pinus halepensisL. demonstrated the presence of 4- O-linked hydroxycinnamyl aldehyde end groups and 4- O-linked 4-hydroxy-3-methoxy-benzaldehyde (vanillin) end groups in lignins. However, given the relatively low abundance of 4- O-linked vanillin in lignifying cell walls and the low extinction coefficient of its red-brown phloroglucinol adduct, it is unlikely that vanillin contributes to a great extent to the phloroglucinol-positive stain reaction. These results suggest that the phloroglucinol-HCl pink stain of lignifying xylem cell walls actually reveals the 4- O-linked hydroxycinnamyl aldehyde structures contained in lignins. Histochemical studies showed that these aldehyde structures are assembled, as in the case of coniferyl aldehyde, during the early stages of xylem cell wall lignification.

Arachidonic Acids↗
PubMed1968

Studies on the role of polyamines associated with the ribosomes from Bacillus stearothermophilus.

1. Spermine and spermidine were the main polyamines detectable in Bacillus stearothermophilus. 2. When grown at 65 degrees B. stearothermophilus contained lower concentrations of polyamines per mg. of RNA than when grown at 45 degrees or at 55 degrees . 3. Ribosomes isolated from B. stearothermophilus in 0.01m-tris-hydrochloric acid buffer (pH7.4)-0.01m-magnesium chloride contained sufficient polyamines to neutralize between 4% and 9% of their RNA phosphorus. 4. Removal of polyamines from the ribosomes by dialysis against m-potassium chloride did not appreciably alter the hypochromicity or thermal denaturation profiles of the ribosomes when measured in 0.01m-tris-hydrochloric acid buffer (pH7.4)-0.01m-magnesium chloride, though it did cause a loss of ribosome particles sedimenting at greater than 78s. 5. When ribosomes were dialysed against acridine orange solutions acridine orange bound to the ribosomes and did not displace spermine, but when a mixture of ribosomal RNA and spermine was dialysed against acridine orange the acridine orange displaced the spermine. It is concluded that polyamines in the ribosomes are less accessible for displacement by acridine orange than when polyamines are bound to ribosomal RNA.

Acridines↗
PubMed2001

[Relations of acid-base balance and gastric secretion of hydrogen carbonate ions in patients with peptic ulcer].

AIM: To study acid-base balance (ABB) of the organism, gastric secretion of hydrocarbonate (HCO3-) in ulcer patients and to examine their relationships. MATERIAL AND METHODS: ABB in capillary or venous blood before and after losec and famotidine treatment and gastric secretion of HCO3- were studied in 72 patients with ulcer. RESULTS: It was found that patients with gastroduodenal ulcer have metabolic, less frequently hypercapnic acidosis with suppressed gastric secretion of HCO3-. This entails abnormal neutralization of the hydrochloric acid imitating high acidity of the gastric juice. HCO3- secretion is inversely proportional to pH. H2-blockers normalize ABB in ulcer patients while losec either stimulates acidosis or transforms one kind of acidosis into another. CONCLUSION: ABB and gastric secretion of HCO3- are related. Acidosis in ulcer patients leads to reduction of HCO3- production and intensification of hydrochloric acid secretion.

Acid-Base Equilibrium↗
PubMed1976

[Spinning of rapeseed proteins].

Alkaline solutions of a mixture from rapeseed globulin and casein show plastic flow, which is influenced by protein concentration, relation of rapeseed globulin and casein, temperature and time of storage of the protein solution. The sodium hydroxide concentration with a great variability doesn't take effect on the rheological properties. With increasing content of casein in such alkaline solutions of rapeseed globuline and casein results an approach to NEWTONian flow. The spinnability of alkaline solutions of a mixture from rapeseed globulin and casein and the properties of the corresponding spun protein fibers are influenced by protein concentration, relation of rapeseed globulin and casein of the spinning solution and temperature of coagulating bath. The sodium hydroxide content of the spinning solution and the hydrochloric acid concentration of the coagulating bath with a great variability don't take effect. The spinnability of alkaline solutions of a mixture from rapeseed albumin starchsulphate and casein and the properties of the corresponding spun protein fibers compared to rapeseed globulin-casein mixtures are influenced additionally by sodium hydroxide concentration of the spinning solution and hydrochloric acid content of coagulating bath. The favourable influence on the properties of spun rapeseed albuminstarchsulphate-casein fibers isn't increased by a growth of the rapeseed albumin starchsulphate content more then 4% of the protein concentration of the spinning solution.

Albumins↗
PubMedDate not supplied

[Effect of adrenoblockaders on gastric secretion].

The effects of phentolamine and propranolol in doses 2.5 mg/kg on histamine gastric secretion were examined in dogs operated on according to the V. A. Basov's method. It was ascertained that phentolamine raised the secretion rate by 2.6 times, the hourly output of hydrochloric acid by 4.4 times, secretion of pepsin and chlorides by 2.5 times. Propranolol did not affect gastric secretion. Administration of phentolamine in a dose of 0.025 mg/kg three times a day for 10 days ta patients with a moderately pronounced atrophic gastritis increased the secretion rate and pepsin secretion by 1.8 times. The hourly output of hydrochloric acid rose by 2.8 times.

Adrenergic alpha-Antagonists↗
PubMed1980

Innervation of the gastric wall related to acid secretion: a light and electron microscopy study on rats, rabbits and guinea pigs.

The increasing use of vagotomy for the surgical treatment of ulcers has stimulated interest in the structure and function of the gastric wall innervation. This paper presents a survey based on microphotographs (rat, rabbit, and guinea pig) of the stomach innervation. Special attention is paid to the relationship between the vagus nerve and the intramural nervous system and the ganglion cells, synaptic junctions in the gastric wall, the innervation of the mucosa and its relationship to mast and parietal cells. The functional significance of the findings is discussed: (1) the electron microscopic evidence of synaptic junctions on parietal cells shows that hydrochloric acid secretion is influenced directly by the nervous system. The nerves terminating at the parietal cells originate exclusively from the myenteric plexus where the vagus fibres already terminate without entering the mucosa. (2) The innervation of mast cells and their proximity to the parietal cells makes some indirect nervous influence on hydrochloric acid secretion likely.

Animals↗
PubMed1977

Control of extraction of deoxyribonucleic acid and apurinic acid by polyethylene glycol in Feulgen hydrolysis.

The polymer polyethylene glycol combined with hydrochloric acid was used during the hydrolysis stage of the Feulgen method in order to limit the movement of the soluble molecular fragments developed through hydrolytic breakdown of the deoxyribonucleic acid. The diffusion of the purines was not influenced by the addition of concentration of the polymer up to 30%. On the other hand, a substantial retardation of the extraction of deoxyribonucleic acid and apurinic acid was noted. This indicates that deoxyribonucleic acid and apurinic acid are extracted in chains of considerable length. The decrease in diffusion rate was greater at 1 M HCl than at 0.3 and 6 M HCl, which indicates that the deoxyribonucleic acid-apurinic acid fragments are larger at the medium concentration of acid than at the low and high concentrations. The results thus strengthen the view that deoxyribonucleic acid and apurinic acid are extracted in chains during hydrolysis, and that the critical length at which the chains becomes diffusible is one of the main factors determining the form of the Feulgen hydrolysis curve. The use of polyethylene glycol to extend the maximum of the hydrolysis curve, and thus to make the temperature and time of hydrolysis less critical, is recommended.

Apurinic Acid↗
PubMed2002

Intramucosal-arterial PCO2 gap fails to reflect intestinal dysoxia in hypoxic hypoxia.

INTRODUCTION: An elevation in intramucosal-arterial PCO2 gradient (DeltaPCO2) could be determined either by tissue hypoxia or by reduced blood flow. Our hypothesis was that in hypoxic hypoxia with preserved blood flow, DeltaPCO2 should not be altered. METHODS: In 17 anesthetized and mechanically ventilated sheep, oxygen delivery was reduced by decreasing flow (ischemic hypoxia, IH) or arterial oxygen saturation (hypoxic hypoxia, HH), or no intervention was made (sham). In the IH group (n = 6), blood flow was lowered by stepwise hemorrhage; in the HH group (n = 6), hydrochloric acid was instilled intratracheally. We measured cardiac output, superior mesenteric blood flow, gases, hemoglobin, and oxygen saturations in arterial blood, mixed venous blood, and mesenteric venous blood, and ileal intramucosal PCO2 by tonometry. Systemic and intestinal oxygen transport and consumption were calculated, as was DeltaPCO2. After basal measurements, measurements were repeated at 30, 60, and 90 minutes. RESULTS: Both progressive bleeding and hydrochloric acid aspiration provoked critical reductions in systemic and intestinal oxygen delivery and consumption. No changes occurred in the sham group. DeltaPCO2 increased in the IH group (12 +/- 10 [mean +/- SD] versus 40 +/- 13 mmHg; P < 0.001), but remained unchanged in HH and in the sham group (13 +/- 6 versus 10 +/- 13 mmHg and 8 +/- 5 versus 9 +/- 6 mmHg; not significant). DISCUSSION: In this experimental model of hypoxic hypoxia with preserved blood flow, DeltaPCO2 was not modified during dependence of oxygen uptake on oxygen transport. These results suggest that DeltaPCO2 might be determined primarily by blood flow.

Analysis of Variance↗
PubMed1990

The role of platelet activating factor [correction of actor] in acute gastric injury and its protection by sucralfate.

Platelet activating factor, a potent inflammatory mediator, has been reported to induce gastrointestinal damage, whereas its inhibition or antagonism is associated with mucosal protection. The aim of the present study was to elucidate the association between acute experimental gastric damage and mucosal platelet activating factor generation in the rat, and to evaluate the protective effect of sucralfate in relation to mucosal platelet activating factor formation. Gastric damage in the rat was induced by either subcutaneous injection of indomethacin 30 mg/kg or intragastric administration of aspirin 100 mg/kg, hydrochloric acid 0.6 N, taurocholate 30 mM, ethanol 96%, or sodium chloride 25%. All agents induced a significant increase in mucosal platelet activating factor levels concomitantly with induction of mucosal damage. Pretreatment with sucralfate 150 mg/rat provided a significant macroscopic and microscopic mucosal protection in all experimental models. This protection was associated with a significant decrease in mucosal platelet activating factor level in the hydrochloric acid, taurocholate, ethanol and hyperosmolar sodium chloride treated rats, whereas it remained unchanged in the aspirin and indomethacin treated rats. The data imply that platelet activating factor may have a limited role in the pathogenesis of indomethacin or aspirin induced damage, where other mechanisms such as cyclooxygenase inhibition dominate. In the damage induced by topical strong irritants, platelet activating factor may have a major pathogenetic role.

Animals↗
PubMed1986

[Chemistry and pharmacology of pyran derivatives. XVII. Synthesis of 2-(dialkylamino)-5-hydroxychromones and their transformation to derivatives of 2H-pyran[4,3,2-de]-1-benzopyran].

Through the reaction of resorcin with N,N-dialkylethoxy-carbonylacetamides in suitable conditions 2-(dialkylamino)-5-hydroxychromones (II) were available. Transformation of these compounds into [5-acetoxy-2-(dialkylamino)-4H-chromen-4-ylidene] malononitriles (VII) by reaction with malononitrile in acetic anhydride and treatment of (VII) with hydrochloric acid gave rise to the formation of 5-(dialkylamino)-2-imino-2H-pyrano [4,3,2-de]-1-benzo-pyrans (VIII). Furthermore 5-hydroxychromones (II) when treated with methyl iodide gave the corresponding 5-methoxychromones (III) which in turn yielded 4H-chromen-4-ylidene derivatives (X) by reaction with malononitrile in acetic anhydride. The hydrolysis of the latter compounds with hydrochloric acid resulted in the formation of 2-(dialkylamino)-4-methyl-5-methoxychromenilium salts (XI). Among the compounds which were submitted to pharmacological screening for their antiallergic properties 5-methoxychromone (III a) and 2H-pyrano [4,3,2-de]-1-benzopyran (VIII b) showed a notable activity but also high toxicity.

Animals↗
PubMed2005

Quantitative determination of the ligand content in Benzamidine Sepharose 4 Fast Flow media with ion-pair chromatography.

A quantitative hydrochloric acid hydrolysis-HPLC method was developed for the analysis of the ligand content of Benzamidine Sepharose 4 Fast Flow media. The method requires about 100 mg of dried sample and simple reaction vials can be utilised. Release of the ligand (p-aminobenzamidine) from the base matrix (Sepharose 4 Fast Flow) was obtained after hydrolysis for 180min at 70 degrees C in concentrated hydrochloric acid. When Benzamidine Sepharose 4 Fast Flow media were treated this way p-aminobenzoic acid and p-aminobenzamidine were the only products released from the ligand. A chromatographic system based on ion-pair reversed phase separation was used to quantify these ligand products. The mobile phase was made acidic enough to make p-aminobenzoic acid and p-aminobenzamidine positively charged in order to make ion-pair formation with hexanesulfonic acid possible. The relative standard deviation of th e method was below 2% and no systematic errors could be detected when the results were compared to an independent method based on elemental analysis (nitrogen). The new HPLC method was used to analyse ligand densities in the range of 2-20 micromol/ml medium.

Benzamidines↗
PubMed2002

Intracellular and extracellular pHs of Streptococcus mutans after addition of acids: loading and efflux of a fluorescent pH indicator in streptococcal cells.

A pH-sensitive fluorescent dye, 2', 7'-bis-(2-carboxyethyl)-5 and 6-carboxyfluorescein (BCECF), was used to determine intracellular pH (pH(in)). The efflux of BCECF loaded into oral streptococcal cells was determined after incubation of the cells at 35 degrees C for 20 min in the presence and absence of glucose. In the absence of glucose, the fluorescence of intracellular BCECF in Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius and Streptococcus sobrinus decreased only very slightly, indicating that the dye could be useful for pH(in) determination. In the presence of glucose, however, the fluorescence decreased by 57%. Thus, the pH(in) of S. mutans cells was measured by the BCECF method in the absence of glucose at various acidic pH levels by adding lactic, acetic and hydrochloric acids to the cell suspensions. The pH(in) was almost equal to the extracellular pH (pH(out)) for pH(out) values of between 8 and 5, indicating that protons permeated easily across the S. mutans cell membrane. For pH(out) between 5 and 4, pH(in) was constant at around 5, suggesting that the cell membrane was impermeable to protons, or that a cytoplasmic buffering system functioned. pH(in) decreased at pH(out) values of < 4. The constant pH(in) at acidic pH(out) levels could protect intracellular components, such as proteins, against acidification by sugar fermentation.

Acetic Acid↗
PubMed1976

[Learning and chronobiological regulation following experimental damage to the coronary-artery wall of albino rats].

Forty male albino rats were used to study the relationship between experimentally (concentrated hydrochloric acid) produced local structural changes of the coronary artery wall and central nervous information processing and chronobiological events, respectively. The alterations of the coronary arteries caused by this treatment did not produce infarction but initiated on the whole length of the arterial branch proliferative processes that are complete within 12 weeks following the intervention. Central nervous information processing and chronoregulatory processes showed, immediately after exposure to hydrochloric acid, pronounced malfunctions followed by a stage of hyperreactivity (4 weeks following the damage). At 8 weeks from the intervention, the parameters of information processing and chronobiological events of the CNS again equalled the control values. Since the central nervous functions were back to normal earlier than the structural alterations, the results are interpreted as reflecting CNS-controlled interactions between the complex of visceral afference and efference, the regulation of which is determined by the CNS after coronary damage in such a way as to restore the adaptational capacity of the organism by a predominance of sanogenetic processes.

Animals↗
PubMed1991

[Clinical research and mechanical inquiry in the treatment of chronic superficial gastritis using ziwuliuzhu day-prescription of acupoint].

According to the day-prescription of acupoint mentioned by Xu Feng in Encyclopaedia of Acupuncture and Moxibustion, the authors used opening acupoints to treat 31 chronic superficial gastritis patients (young male) and closing points to treat 15 patients for comparison. Besides, the authors observed the changes of hydrochloric acid of gastric juice, volume of juice and serum gastrin of the patients before and after the acupuncture. Results of clinical treatment: In the opening acupoint group, 13 were cured, 12 effected, 4 improved and 2 ineffective. The total effective rate was 93.55%. There was no significant difference between the results of the two groups. Results of experiment: to the hyperacidity patients of the two groups, the content of hydrochloric acid tended to fall after acupuncture while to the hypoacidity patients the content tended to rise after acupuncture. The changes of the gastric juice volume were different in the two groups. In the opening group, we could also see that the low volume rose and high volume fell after acupuncture. However, the closing group showed that the low volume fell after acupuncture. There was not any significant difference. The changes of serum gastrin indicated that, after acupuncture, all the serum gastrin in the two groups went up. But the peak value in the opening group appeared at 30 minutes after acupuncture while in the closing group it appeared at one hour. In both groups, there were significant differences between those results before and after acupuncture.

Acupuncture Therapy↗
PubMed1975

Evaluation of a new method for the intragastric titration of gastric juice.

A new method for the intragastric titration of hydrochloric acid with a pH sensitive telemetric antimone electrode connected via a receiver to an electronic trigger, which regulates a pump for the inflow of 1 M KHCO3 solution, was evaluated in 22 achlorhydric patients by a series of intragastric instillations of 0.1 N HCl. In vitro this procedure presented a high precision (r = 0.99). Under in vivo conditions a significant correlationship (r = 0.84, p = 0.001) between the input of hydrochloric acid and bicarbonate in a range from 1.4 to 16.7 mEq/30 min could be established in non-operated subjects. The average coefficient of variation was 34%. In subjects with partial gastrectomy (Billroth II) overtitration of 100% (y = 2.1 x -1.7, r = 0.78, p = 0.001) was recorded, suggesting an increased loss of bicarbonate related to the accelerated gastric evacuation.

Achlorhydria↗