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PubMed1968

Mitotic apparatus: the selective extraction of protein with mild acid.

The treatment of isolated mitotic apparatus with mild (pH 3) hydrochloric acid results in the extraction of less than 10 percent of its protein, accompanied by the selective morphological disappearance of the microtubules. The same extraction can be shown to dissolve outer doublet microtubules from sperm flagella. A protein with points of similarity to the flagellar microtubule protein is the major component of the extract from mitotic apparatus.

Animals↗

PubMed1989

Effects of drinking water acidification, restriction of water supply and individual caging on parameters of toxicological studies in rats.

A 21 week experiment was conducted with male SPF Ico/Shoe: WIST rats to study the influence on diagnostic parameters of toxicological studies of (i) acidification of drinking water by hydrochloric acid (untreated tap water vs. pH 3 vs. pH 2), (ii) individual vs. group caging (5 animals/cage), and (iii) ad libitum vs. 10 ml restrictive water supply. Acidification to pH 2 resulted in a slightly but significantly reduced excretion of phenol red, lowered proteinuria and a decreased urine volume, whereas all other parameters remained unchanged. Individual caging was less stressful than expected from published data. Red blood cell counts were increased, water consumption and urine volume were somewhat lowered, but stress-sensitive parameters like adrenal weight, leucocyte and lymphocyte counts were not altered. A 10 ml restrictive water supply decreased urine volume, food consumption, body weight development and organ weights. Furthermore transient increases in red blood cell counts and hemoglobin contents, leucopenia and--most important--an impaired renal function were observed. In conclusion acidification of drinking water with hydrochloric acid should not be lower than pH 3, male Ico/Shoe: WIST rats can be regarded as minimum susceptible to individual caging, and reduced water intake might give false positive nephrotoxic effects.

Animals↗

PubMedDate not supplied

Similarity of taste reactivity responses to alcohol and sucrose mixtures in rats.

The orofacial responses of rats following infusion of taste solutions were examined in two experiments. In the first experiment, naive rats were presented with a 6% alcohol solution and three sucrose mixtures (sucrose combined with quinine hydrochloride, hydrochloric acid, and sodium chloride, respectively) on separate trials and the resulting taste reactivity was examined. The only difference among the solutions was that alcohol elicited a significantly larger number of aversive responses (e.g., gapes, passive drips) than the sucrose mixtures. In the second experiment, naive rats were trained to avoid 6% alcohol using standard conditioned aversion procedures; rats were then tested for reactivity to the three sucrose mixtures and the alcohol solution. With the alcohol solution, trained rats displayed significantly fewer ingestive responses and significantly more aversive responses than control rats. The response of trained rats to the sucrose + quinine solution was similar to that of alcohol: fewer ingestive responses and more aversive responses than control rats. The number of aversive responses to the alcohol and the sucrose + quinine mixture by the trained rats did not differ significantly. Reactivity to the sucrose + hydrochloric acid and sucrose + sodium chloride solutions did not differ between trained rats and control rats. The results suggest that a sucrose + quinine solution has a perceived taste (as revealed by elicited orofacial reflexes) similar to alcohol and that the sucrose mixture is avoided by rats with alcohol aversions because it is unpalatable.

Animals↗

PubMed1982

Independence of the acute acid-buffering response from endogenous parathyroid hormone.

Two recent reports have made the provocative suggestion that parathyroid hormone (PTH) and, by implication, bone play a critical role in the early phase of acid buffering. The purpose of the present study was to investigate the effect of PTH on the acute buffering process by examining the influence of thyroparathyroidectomy (TPTX) on acid-base parameters in nephrectomized rats following infusion of hydrochloric acid at two differing doses. To ensure hemodynamic and physiologic stability of the animals, the required surgical procedures were staged over several days. Additionally, the experimental protocol was carried out in awake and unrestrained animals. Non-TPTX (sham) animals underwent a sham operation to equalize the surgical stresses between the two groups. The decrements in plasma [HCO-3] observed following infusion of 3.5 mmol/kg HCl over 1 h did not differ between TPTX vs. sham animals at 1 h (-9.4 vs. -9.9 meq/liter), 3 h (-8.6 vs. 8.6 meq/liter), or 6 h (-8.6 vs. -8.5 meq/liter) from the start of the infusion. Similarly, virtually identical falls in plasma [HCO-3] were observed between TPTX vs. sham rats after infusion of 5 mmol/kg HCl over 30 min at 30 min (-13.6 vs. -14.2 meq/liter) and 3 h (-10.9 vs. -11.4 meq/liter) after the start of the infusion. At both doses, the resultant changes in plasma [H+] and PaCO2 were not different in the two groups. The observed mortality was comparable in both TPTX and sham groups. The data demonstrate that endogenous PTH is not necessary in the early phase of buffering of a mineral acid load.

Acid-Base Equilibrium↗

PubMed1977

Acid releases motilin from human duodenum in vitro.

The effect of hydrochloric acid and sodium hydroxide on motilin release from human duodenal mucosa was studied in vitro. Tissue was incubated in 2 ml chambers continuously perfused with medium and was exposed repeatedly to the stimuli. Motilin released into the medium was determined by a specific radioimmunoassay. Whereas alkalinisation abolished basal motilin release, acidification resulted in a 14-fold increase of peptide secretion. The results indicate that motilin secretion can be stimulated in vitro and that the perfusion system described may be a useful tool in studying the mechanism of gastrointestinal hormone release.

Duodenum↗

PubMed1990

NTP Toxicology and Carcinogenesis Studies of l-Epinephrine Hydrochloride (CAS No. 55-31-2) in F344/N Rats and B6C3F1 Mice (Inhalation Studies).

l-Epinephrine, an endogenous neurotransmitter hormone, is widely used for the treatment of allergic and respiratory disorders. NTP Toxicology and Carcinogenesis studies of epinephrine hydrochloride were conducted by exposing groups of F344/N rats and B6C3F1 mice of each sex to an aerosol containing epinephrine hydrochloride for 14 days, 13 weeks, 15 months, or 2 years. During the 14-day and 13-week studies, control animals were exposed to dilute aerosols of hydrochloric acid (pH 2.8), whereas during the 15-month and 2-year studies, controls were exposed to aerosols of water. Genetic toxicology studies of epinephrine were conducted in Salmonella typhimurium and Chinese hamster ovary (CHO) cells. Fourteen-Day Studies: Rats and mice were exposed to 0 or 12.5-200 mg/m3 epinephrine hydrochloride. Deaths occurred in male rats exposed to 12.5 mg/m3 or more and in females exposed to 25 mg/m3 or more. Deaths of mice occurred at concentrations of 50 mg/m3 or higher. Compound-related clinical signs included an increased respiratory rate in all groups of epinephrine-exposed rats and mice. At higher concentrations (100 and 200 mg/m3), excessive lacrimation and dyspnea in rats and exaggerated visual and auditory reflexes in mice were observed. Thirteen-Week Studies: Rats and mice were exposed to 0 or 2.5-40 mg/m3 epinephrine hydrochloride. Deaths in rats and mice were not concentration related. Final mean body weights of chemically exposed and hydrochloric acid aerosol control rats and mice were generally similar. Increased respiratory rates were noted in rats and mice exposed to 40 mg/m3. Heart and adrenal gland weights of rats and mice and liver weights of mice exposed to 40 mg/m3 were greater than those of aerosol controls. Squamous metaplasia occurred in the respiratory epithelium of the nasal mucosa of rats and mice exposed to 40 mg/m3. Degenerative lesions of the laryngeal muscle were seen in male and female rats exposed to 20 or 40 mg/m3. Inflammation in the glandular stomach was seen in male and female mice exposed to 10, 20, and 40 mg/m3, and uterine atrophy was seen in 7/10 female mice exposed to 40 mg/m3. Two-year studies were conducted by exposing groups of 60 rats or each sex to 0, 1.5, or 5 mg/m3 epinephrine hydrochloride, 5 days per week for 103 weeks. Groups of 60 mice of each sex were exposed to 0, 1.5, or 3 mg/m3 epinephrine hydrochloride, 5 days per week for 104 weeks. Use of these exposure concentrations represented a departure from the usual practice of utilizing doses equivalent to one-half the maximum tolerated dose (MTD) and the MTD for 2-year carcinogenicity studies. Thus, although the dose levels exceeded maximum human therapeutic use levels (normalized to body weight and surface area), they were less than one-half the MTD. Fifteen-Month Studies: Results of hematologic analyses did not show compound-related changes. Absolute liver weights for exposed mice (3 mg/m3) and rats (5 mg/m3) and relative liver weights for exposed rats (5 mg/m3) were significantly lower than those for controls. The absolute kidney weights for mice exposed to 3 mg/m3 and the kidney weight to body weight ratio for male mice exposed to 3 mg/m3 were significantly lower than those for controls. No compound-related lesions were seen in rats or mice. Body Weights and Survival in the Two-Year Studies: Mean body weights and survival of exposed and control rats and mice were similar (survival, rats--male: control, 33/50; 1.5 mg/m3, 27/50; 5 mg/m3, 32/50; female: 32/50; 29/50; 30/50; mice--male: control, 33/50; 1.5 mg/m3, 34/50; 3 mg/m3, 36/50; female: 32/50; 35/50; 34/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Suppurative inflammation of the nasal mucosa, dilatation of the nasal glands (Bowman's and septal), and hyperplasia of the respiratory epithelium were seen at increased incidences in male rats exposed to 5 mg/m3 and in female rats exposed to 1.5 or 5 mg/m3. Hyaline degeneration of the olfactory epithelium in male mice and suppurative inflammation of the nasal passage and hyaline degeneration of the respiratory epithelium in female mice were increased in the 1.5 and 3 mg/m3 groups compared with controls. No neoplasms seen in these studies were considered related to chemical exposure. Genetic Toxicology: Salmonella gene mutation tests with l-epinephrine yielded negative results in strain TA100 in the presence of exogenous metabolic activation (S9) and equivocal results in the absence of S9. No mutagenic activity was observed in strains TA98, TA1535, or TA1537 with or without S9. The responses observed in the CHO cell assay for induction of sister chromatid exchanges were considered to be negative and equivocal in the presence and absence of S9 activation, respectively. l-Epinephrine did not induce chromosomal aberrations in CHO cells with or without S9. Conclusions: Under the conditions of these 2-year studies, no carcinogenic effects were observed in male or female F344/N rats exposed to aerosols containing 1.5 or 5 mg/m3 l-epinephrine hydrochloride for 2 years or in B6C3F1 mice exposed to 1.5 or 3 mg/m3 l-epinephrine hydrochloride for 2 years. However, these studies were considered to be inadequate studies of carcinogenic activity because the concentrations used, which were chosen to represent multiples of therapeutic doses, were considered too low for the animals to have received an adequate systemic challenge from the compound. Synonyms: adrenaline hydrochloride; 4-(1-hydroxy-2-(methylamino)ethyl)-1,2-benzenediol; (-)3,4-dihydroxy-a-((methylamino)methyl)benzyl alcohol hydrochloride; methylaminoethanol catechol hydrochloride Trade names for epinephrine formulations: Primatene®. Mist; Sus-Phrine®.; Epipen®.; Supravenin Hydrochloride®.; Bronkaid®.

Journal Article↗

PubMed2002

The effect of mutations on the structure of insulin fibrils studied by Fourier transform infrared (FTIR) spectroscopy and electron microscopy.

Fibril formation (aggregation) of human and bovine insulin and six human insulin mutants in hydrochloric acid were investigated by visual inspection, Thioflavin T fluorescence spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. The fibrillation tendencies of the wild-type insulins and the insulin mutants were (in order of decreasing fibrillation tendencies): Glu(B1) + Glu(B27) = bovine < human < des-(B1,B2)-insulin < Ser(B2) + Asp(B10) < Glu(A13) + Glu(B10) = Gln(B17) < Asp(B10). Transmission electron micrographs showed that the protofibrils of the mutants were similar to those of wild-type insulins and had a diameter of 5-10 nm and lengths varying from 50 nm to several microns. The fibrils of human insulin mutants exhibited varying degrees of lateral aggregation. The Asp(B10) mutant and human insulin had greater tendency to form laterally aggregated fibrils arranged in parallel bundles, whereas fibrils of the other mutants and bovine insulin were mainly arranged in helical filaments. FTIR spectroscopy showed that the native secondary structure of the wild-type insulins and the human insulin mutants in hydrochloric acid were identical, whereas the secondary structure of the fibrils formed by heating at 50 degrees C depended on the amino acid substitution. FTIR spectra of fibrils of the human insulin mutants exhibited different beta-sheet bands at 1,620-1,640 cm(-1), indicating that the beta-sheet interactions in the fibrils depended on variations in the primary structure of insulin.

Animals↗

PubMed1982

Taste aversion to sugars by the gerbil.

Some conditioned taste aversion experiments were undertaken to determine how the gerbil responds to disaccharides, monosaccharides and polyols. We observed the following: animals taught an aversion to 0.1 M sucrose generalized the avoidance to most sugars, the exception being galactitol; animals taught to avoid 0.01 M hydrochloric acid generalized the avoidance towards lactose, cellobiose, maltitol, methyl alpha-D-galactopyranoside, methyl alpha-D-mannopyranoside, methyl beta-D-glucopyranoside, and glycerol; animals taught to avoid 0.001 M quinine . HCl generalized the avoidance towards methyl alpha-D-glucopyranoside, methyl-beta-D-glucopyranoside, glycerol, ethylene glycol and erythritol. In no case did animals taught to avoid 0.1 M sodium chloride avoid any of the sugars. Moreover, it was observed that the gerbil's behavior with most reducing sugars was different than with equivalent methyl glycosides. For example, animals that were taught to avoid sucrose generalized the avoidance towards reducing sugars, such as, D-galactose, D-glucose, and D-mannose. However, the methyl glycosides, such as methyl alpha-D-glucopyranoside, methyl beta-D-glucopyranoside, methyl alpha-D-galactopyranoside and methyl alpha-D-mannopyranoside, in addition to being avoided by animals taught to avoid sucrose, were also avoided by animals taught to avoid quinine . HCl or hydrochloric acid. In addition, we have observed that the control animals consumed differing amounts of sugars and have concluded, therefore, that the sugars were not equally pleasant despite our attempt to use concentrations which produced equally intense neural responses in the gerbil's chorda tympani nerve.

Animals↗

PubMedDate not supplied

Determination of insoluble, soluble, and total dietary fiber in foods and food products: interlaboratory study.

A collaborative study was conducted to determine the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), and total dietary fiber (TDF) content of food and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that developed for TDF only, which was adopted official final action by AOAC, except for changing the concentration of buffer and base and substituting hydrochloric acid for phosphoric acid. These changes were made to improve the robustness of the method. Duplicate blind samples of soy isolate, white wheat flour, rye bread, potatoes, rice, corn bran, oats, Fabulous Fiber, wheat bran, and a high fiber cereal were analyzed by 13 collaborators. Dietary fiber values (IDF, SDF, and TDF) were calculated as the weight of residue minus the weight of protein and ash. The coefficients of variation (CVs) of both the independent TDF determination and the sum of IDF and SDF were better than 15 and 18%, respectively, with the exception of rice and soy isolate. These 2 foods, however, contained only about 1% TDF. The CVs of the IDF were equally good, except for Fabulous Fiber, for which filtration problems occurred. The CVs for the SDF were somewhat high, but these products had very low SDF content. There was excellent agreement between the TDF determined independently and the TDF determined by summing the IDF and SDF. The method for separate determination of IDF and SDF requires further study. The modifications (changes in concentration of buffer and base and the use of hydrochloric acid instead of phosphoric acid) to the official final action method for TDF have been adopted.

Bread↗

PubMed2005

Effects of nitric oxide synthase inhibitor on acid aspiration-induced lung injury in rats.

The current study was designed to determine the effects of nitric oxide synthase (NOS) in the development of acid aspiration-induced lung injury in rats. Hydrochloric acid (HCl, 0.1 N; 2 ml/kg) or normal saline (NS, 2 ml/kg) was instilled into the lung of anesthetized, ventilated Sprague-Dawley rats. NG-monomethyl-L-arginine (L-NMMA, 20 mg kg(-1)) and a selective inducible nitric oxide synthase (iNOS) inhibitor, ONO-1714 (0.1 and 0.3 mg kg(-1)), were used to block NOS. Bronchoalveolar lavage fluid (BALF) and wet and dry measurements of lung (W/D) were obtained 5h after HCl or NS instillation. Unlike the control group, rats instilled with HCl showed significant increases in total nuclear cell counts (NCC), neutrophil counts, concentrations of albumin, tumor necrosis factor-alpha (TNF-alpha), interleukine-6 (IL-6) and nitrites/nitrates (NO(x)) in BALF. These parameters were associated with the significantly increased W/D in the HCl group compared with the NS group. ONO-1714 (0.1 mg kg(-1)) significantly prevented the increases in all these parameters. Its inhibitory effects were superior to those of L-NMMA and 0.3 mg kg(-1) of ONO-1714. NOS plays an important role in the pathogenesis of acid aspiration-induced lung injury. Furthermore, selective iNOS inhibition at the optimal dose was most effective in improving lung injury induced by acid aspiration in rats.

Amidines↗

PubMed1980

Changes in renal metabolite profile and ammoniagenesis during acute and chronic metabolic acidosis in dog and rat.

Acute metabolic acidosis was induced by an i.v. administration of hydrochloric acid to dogs and rats to decrease the plasma bicarbonate concentration from 22 to 12 mM in dogs and from 26 to 10 mM in rats. Chronic metabolic acidosis was also induced in dogs by ammonium chloride feeding for 5 days. Rats also were given ammonium chloride for 24 hours. The renal metabolite profile was determined on the freeze-clamped renal tissue before and after 100 min (dogs) or 30 to 240 min (rats) of acsute acidosis. Measurements on chronically acidotic dogs and rats with 24-hour acidosis were obtained also for comparison with acute acidosis. In both species, kidney glutamine, glutamate, and alpha-ketokglutarate concentrations decreased drastically following induction of acute or chronic acidosis, In the dog, or in the rat during the first 2 hours of acidosis, malate concentration was unchanged. Malate concentration fell significantly in the rat kidney only after 2 hours of acidosis without change in phosphoenolpyruvate (PEP) concentration. In chronically acidotic dogs, malate and oxaloacetate rose fivefold with no change in PEP concentration. Phosphoenolpyruvate carboxykinase (PEPCK) activity was not stimulated by chronic metabolic acidosis in the dog in contrast to the rat. Acute acidosis by hydrochloric acid increased net renal glutamine extraction in the rat but not in the dog. These data suggest that an increased metabolic flux occurs between alpha-ketoglutarate and malate in both rat and dog kidney during acute metabolic acidosis. In the rat, however, after 2 hours, PEPCK activation modifies the kidney metabolite profile. Intrarenal glutamine transport seems to be a rate-limiting factor for adaptation to acute acidosis in the dog but not in the rat kidney.

Acidosis↗

PubMed1983

Drug interactions. II. Formation of nitrosamines from therapeutic drugs. Properties and kinetics of the formation of N-nitrosopropranolol from nitrite and the secondary amine propranolol hydrochloride.

In the presence of hydrochloric acid, nitrosamines may be generated from amines and nitrite. Most nitrosamines are carcinogens and many commonly used drugs contain potentially nitrosatable amine groups. Beta-adrenergic blockers, which have such amine groups, are widely prescribed and are often ingested for the lifetime of the patients, but their safety with respect to the intragastric formation of nitrosamines has not been established. The studies in this and the following report were designed to assess the potential risk posed by the endogenous formation of a nitrosamine in the stomach to individuals receiving longterm treatment with propranolol hydrochloride. The putative nitrosamine, N-nitrosopropranolol (NNP), was synthesized and its stability was examined under various experimental conditions. A high-pressure liquid chromatographic method was developed which detects a minimum of 7 X 10(-11) mol of NNP in the presence of large quantities of unreacted drug. Preparations of propranolol hydrochloride were found to contain several non-nitrosamine contaminants, which were removed before kinetic studies. At 37 degrees C, in solutions of HCl within the pH range found in the stomach, the optimum pH for the formation of NNP was 3. The yield of NNP increased linearly as incubation time and concentration of propranolol increased and exponentially as the concentration of nitrite was raised. Under optimal conditions in hydrochloric acid, the minimum concentration of nitrite required for the production of detectable amounts of NNP was 10(-5) M.

Chemical Phenomena↗

PubMed1999

Acid-induced lung injury. Protective effect of anti-interleukin-8 pretreatment on alveolar epithelial barrier function in rabbits.

Although prior experimental work has demonstrated that anti-interleukin-8 (anti-IL-8) therapy reduces lung endothelial injury after acid instillation, there is no information regarding the effect of anti-IL-8 on the function of the alveolar epithelial barrier after acid-induced lung injury. Therefore, the primary objective of this study was to determine the effect of acid-induced lung injury on the function of the alveolar epithelium, and secondly to determine whether pretreatment with anti-IL-8 attenuates acid-induced injury to the lung epithelial barrier. Hydrochloric acid (pH = 1.5 in 1/3 normal saline) was instilled into the lungs of anesthetized, ventilated rabbits. Anti-IL-8 monoclonal antibody (2 mg/kg) or saline was given intravenously 5 min before acid instillation. Acid instillation into the distal airspaces caused an increase in the alveolar epithelial permeability to protein and an approximately 50% reduction in net alveolar fluid clearance. Because a decrease in net alveolar fluid clearance could be due to lung endothelial injury and increased fluid flux from the blood into the airspaces, additional experiments were carried out in which pulmonary blood flow was eliminated. In the absence of pulmonary blood flow, acid instillation led to a 50% decrease in net alveolar fluid clearance. Pretreatment with anti-IL-8 antibody significantly reduced the acid-mediated increase in bi-directional transport of protein across the alveolar epithelium and restored alveolar fluid clearance to normal. The results indicate that acid instillation causes injury to the alveolar epithelial barrier that can be distinguished from the injury to the lung endothelium. Furthermore, pretreatment with anti-IL-8 therapy prevents acid-induced alveolar epithelial injury, a finding of potential clinical importance.

Animals↗

PubMed1985

Gastritis, duodenogastric reflux and bacteriology of the gastric remnant in patients operated for peptic ulcer by Billroth I operation.

Of 101 patients undergoing Billroth I gastrectomy (BI) 14 years previously, we were able to investigate 39. General abdominal symptoms, haematological status, basal (BAO) and maximal (MAO) hydrochloric acid secretion were studied before (I) and 1 year (II) and 14 years (III) after the operation. Stump mucosa morphology was investigated before the operation and 14 years afterward. Duodenogastric reflux with radioisotope and fasting bile reflux methods and stump bacteriology were studied at the last follow-up and compared with those of controls who had had peptic ulcer 15 years ago. Only 10% of the operated patients could be classified as Visick Grade III, the others being Grades I-II. At the time of the follow-up, mean body weight had not changed. Serum iron was better at 14 than one years after the operation. BAO and MAO decreased significantly after the operation, but these decreases did not continue during the postoperative period. Duodenogastric reflux was significantly greater in the gastrectomized patients than in the controls. Neither the progression of gastritis nor the degree of postoperative gastritis correlated with the reflux. Of the operated patients, 6% had normal stump mucosa and 80% had atrophy. From the stump we cultured colonic bacteria in 44% of the patients, pharyngeal flora in 71% and Candida in 56%. The stomach bacteriology of the controls was: 10% colonic, 35% pharyngeal flora and 30% Candida. The general status of BI-patients remains good. Although gastritis progresses to atrophy and duodenogastric reflux increases, the reflux and atrophy do not seem to be related. In spite of increasing atrophy hydrochloric acid secretion continues.

Aged↗

PubMed1998

Induction of cyclooxygenase-2 in alveolar macrophages after acid aspiration: selective cyclooxygenase-2 blockade reduces interleukin-6 production.

BACKGROUND: Gastric acid aspiration can result in acute lung injury. In this study, the authors determined whether alveolar macrophages express cyclooxygenase-2 as a source of inflammatory mediators after acid aspiration. METHODS: Seventy-five microliters of hydrochloric acid solution, pH 1.15, was instilled into one lung in mice. After exposure, alveolar macrophages were harvested, and competitive polymerase chain reaction and enzyme-linked immunosorbent assay were performed to measure expression of cyclooxygenase-1 and -2, interleukin-1beta and -6, tumor necrosis factor-alpha, and inducible nitric oxide synthase (iNOS). The authors used immunocytochemistry to demonstrate expression of cyclooxygenase-2 in alveolar macrophages. Selective cyclooxygenase-2 blockade using N-2(-cyclohexyloxy-4-nitrophenyl) methane-sulphonamide was done to characterize prostaglandin-cytokine interaction. RESULTS: Acid aspiration induced upregulation of cyclooxygenase-2 and interleukin-6. Tumor necrosis factor-alpha and iNOS were not upregulated. Interleukin-1beta was upregulated even with saline instillation but could not be detected in the supernatant of the cell culture. Alveolar macrophages harvested from mice instilled with acid showed a trend toward more production of prostaglandin E2 and produced higher concentrations of interleukin-6 compared with alveolar macrophages from mice instilled with saline. Selective cyclooxygenase-2 blockade significantly decreased release of interleukin-6 from alveolar macrophages harvested from mice instilled with acid. CONCLUSIONS: Acid aspiration induces strong expression of cyclooxygenase-2 and production of interleukin-6 in alveolar macrophages. Selective cyclooxygenase-2 blockade reduced production of interleukin-6 by acid-stimulated alveolar macrophages. These studies suggest that the induction of cyclooxygenase-2 plays an important role in the systemic inflammatory response induced by acid aspiration.

Animals↗

PubMed2006

Chemical and biochemical generation of carbohydrates from lignocellulose-feedstock (Lupinus nootkatensis)--quantification of glucose.

Different chemical and enzymatic methods were applied for the hydrolysis of main stems from Lupinus nootkatensis (harvest November 2002). The whole process (all steps) is based on the lignocellulose-feedstock biorefinery regime. The acid hydrolysis of L. was performed with concentrated hydrochloric acid; advantages in this process are exothermic hydrolysis and the possibility of acid recovery. Enzymatic hydrolysis achieved high yields of fermentable carbohydrates (regarding to input cellulose) with high selectivity. However, this way requires the generation of cellulose from L. by chemical pulping. Monosaccharide derivatives thus obtained were identified by their GC retention times and the corresponding MS fragmentation. Hexamethyldisilazane was used as derivatization reagent to prepare the trimethylsilyl derivatives of the carbohydrates and of the degradations products of cellulose from the different fractions. The glucose content was quantified by GC peak integration with respect to an internal standard.

Biomass↗

PubMed2000

Investigation of microwave assisted drying of samples and evaporation of aqueous solutions in trace element analysis.

Investigations of microwave assisted drying of sample materials and microwave assisted evaporation of aqueous sample solutions and acidic digestion residues were accomplished by means of special rotors for the microwave digestion system MULTIWAVE. To check the results obtained by microwave assisted drying, the samples were also conventionally dried at 105 degrees C in an oven. The following samples have been dried: 10 g each of meat, fish, apple, cucumber, potato, mustard, yogurt, clay and marl; 1 g each of certified reference material TORT 2 (lobster hepatopancreas), BCR 278 (mussel tissue) and BCR 422 (cod muscle); 500 g garden mould. Microwave assisted drying takes 40 min for organic samples and 30 min for inorganic material. Important is a slow increase of microwave power during the first 20 min. The results agree well with conventional drying at 105 degrees C. Losses of As, Se and Hg have been investigated for 3 CRMs. Only Se shows losses in the range of 20%. Losses of As, Be, Cd, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, Tl, V and Zn after evaporation of aqueous samples and acidic solutions after wet digestion, respectively, have been investigated. 50 mL aqueous solution was evaporated almost to dryness within 25 min. The recovery of Hg is 40-50%, of Se 90-95% and of the other elements 97-102%. 0.2 g each of TORT 2, BCR 278 and BCR 422 have been digested with 4 mL nitric acid and 1 mL hydrochloric acid by means of the microwave digestion system MULTIWAVE. The digestion residue was evaporated almost to dryness and dissolved again in 10 mL diluted nitric acid. In this case no element losses have been observed. The measured concentration of As, Cd, Cu, Fe, Mn, Hg, Pb, Mo, Ni, Se, Sr, V and Zn agree very well with the certified values. An important prerequisite for good recoveries is not to evaporate the solutions to complete dryness.

Acids↗

PubMed1985

Microquantitative analysis of neutral and amino sugars as fluorescent pyridylamino derivatives by high-performance liquid chromatography.

A method for the quantitation of picomole amounts of neutral and amino sugars in glycoconjugates was developed. Glycoconjugates were hydrolyzed with a mixture of equal amounts of 4 M trifluoroacetic acid and 4 M hydrochloric acid, and the free amino groups were acetylated. Sugars were coupled with 2-aminopyridine. After the excess reagents were removed by gel-permeation high-performance liquid chromatography, the fluorescent pyridylamino derivatives of sugars were separated and quantified by high-performance liquid chromatography on a reversed-phase column. This method allowed the determination of 0.01-10 nmol of sugars. About 100 pmol of several glycoconjugates were analyzed by the present method, with satisfactory results.

Amino Sugars↗