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At least 1,459 records · Page 81Linked to original sources
PubMed2000

[Synthesis and identification of methylparathion artificial antigen].

In order to synthesize the artificial antigen methylparathion(M1605), methylparathion was reduced into amino-methylparathion by using acetic acid-zinc powder-hydrochloric acid. Artificial antigens (M1605-BSA, M1605-TTH) were synthesized by conjugating amino-methylparathion to bovine serum albumin(BSA) and tachypleus tridentatus hemocyanin (TTH) directly after diazotization. Rabbits were immunized with M1605-BSA for 10 weeks, and the high titer and high specificity antiserum from those rabbits was testified by double agar gel diffusion and indirect ELISA. The results showed that an artificial antigen was obtained successfully and this made it possible to establish the immunoassay of M1605.

Animals↗
PubMed1990

[Glyyunnanprosapogenin and glyyunnansapogenin from the roots of Glycyrrhiza yunnanensis].

Two new triterpenoidal sapogenins of oleanane type, namely glyyunnanprosapogenin D (V) and glyyunnansapogenin F (IX) were isolated from the roots of Glycyrrhiza yunnanensis Cheng f. et L. K. Tai, family Leguminosae, collected from Yunnan Province, China. V was obtained as hexaacetate and dimethyl ester form (Vc), mp 168-170 degrees C, C56H78O22, which gave an aglycone macedonic acid (V') and two molecules of glucuronic acid after hydrolysis with hydrochloric acid. The spectral analysis of 13CNMR and 1HNMR showed that Vc had two glycoside residues attached to the aglycone, and therefore the structure of V was established as oleana-11, 13(18)-dien-29-oic acid, 3 beta, 21 alpha-di-(O-beta-D-glucuronic acid) pyranoside. IX was obtained as its diacetate and monomethyl ester form (IXc), mp 188-190 degrees C, C35H50O7. The IR, 1HNMR and UV spectra showed that the IXc had a skeleton of oleanane type triterpenoid with heteroannular diene. IXb, diacetate of IX, unpurified, was converted to IXf with chromium trioxide in glacial acetic acid. IXf, mp 160-164 degrees C, C30H46O8, was proved to be olean-12-en-11-oxo-3 beta,24-diacetoxy-18 beta-hydroxy-30-oic acid, 30 in equilibrium 18 beta lactone with another carbonyl group at C-15,16,21 or 22 by the analysis of 13CNMR, 1HNMR and MS spectra.(ABSTRACT TRUNCATED AT 250 WORDS)

Drugs, Chinese Herbal↗
PubMed1975

Extemporaneous preparation of methyldopa in two syrup vehicles.

The stability of methyldopa in two extemporaneous syrup preparations was studied. Film-coated methyldopa tablets were triturated and incorporated into (1) unpreserved Syrup USP and (2) an equal mixture of simple syrup containing 0.5% citric acid and 0.2 N hydrochloric acid, in concentrations of 50 mg/ml. The preparations were stored in the dark, for 14 days at 5 C and 25 C. Samples were analyzed spectrophotometrically for methyldopa content at various intervals. Both preparations were stable under the conditions studied.

Biological Availability↗
PubMed1987

Unconjugated morphine in blood by radioimmunoassay and gas chromatography/mass spectrometry.

Morphine, the active metabolite of heroin, is rapidly inactivated by glucuronidation at the 3 carbon. Unconjugated (pharmacologically active) morphine was measured in postmortem blood by radioimmunoassay using an antibody-coated tube kit. The kit shows less than 0.2% cross-reactivity with codeine and morphine-glucuronide. Unconjugated morphine concentrations were confirmed by gas chromatography/mass spectrometry (GC/MS) using deuterated morphine as the internal standard. The blood was precipitated with 10% trichloroacetic acid (TCA) and concentrated hydrochloric acid (HCl), centrifuged, and decanted. The supernatant was then either diluted (unhydrolyzed) or heated to 100 degrees C, 30 min (hydrolyzed), followed by a wash with 4:1 chloroform:isopropranol. The upper aqueous layer was then saturated with sodium bicarbonate (NaHCO3) and extracted with 4:1 chloroform:isopropranol. The organic layer was evaporated, derivatized with trifluoroacetic anhydride (TFA), and analyzed by selected ion monitoring (SIM) GC/MS. Comparison of the results for unconjugated morphine by radioimmunoassay and unhydrolyzed morphine by GC/MS gave a correlation coefficient of r = 0.98, n = 100. Unconjugated morphine ranged from 0 to 100% of total morphine with a mean of 42%, n = 200, for heroin or morphine involved deaths. Review of 56 putative rapid deaths gave a mean of 68% unconjugated morphine with a range of 26 to 100%. The ratio of unconjugated to total morphine was found to be stable in postmortem blood after more than a year of storage at room temperature, within the precision of the method.

Adolescent↗
PubMedDate not supplied

[Effect of meat pâtés of different composition on gastric secretory function].

Experiments on 4 dogs with isolated Pavlovian pouches were made to study the action on gastric secretion of a new type of a beef paté in which 20% of basic raw material was replaced by precipitated blood plasma proteins (a sample under study) and of a beef paté of a conventional composition (a control sample). Both paté samples were found to provoke a characteristic gastric juice secretion which strongly differed from the secretion pattern during beef feeding. This was determined by the presence in the patés of a significant amount of fat and by the homogenized nature of the paté mass. Gastric juice thus obtained was marked by a slightly decreased acidity, low content of hydrochloric acid pH 1.7-2.6, and moderate pepsin concentration. Replacement in beef paté of 20% of basic raw material by precipitated blood plasma proteins did not provoke any changes in gastric secretion as compared to that seen during intake of patés of a conventional composition.

Animals↗
PubMed1981

A rapid, simple, and sensitive procedure for the determination of free fatty acids in plasma using glass capillary column gas-liquid chromatography.

A rapid and sensitive method for the analysis of plasma free fatty acids with glass capillary column gas-liquid chromatography and flame ionization detection is described. The plasma sample, together with n-pentadecanoic acid as an internal standard, was treated with 2,2-dimethoxypropane and hydrochloric acid. 2,2-Dimethoxypropane serves as water scavenger, deproteinizing agent, and as a methylating agent. Under the assay conditions, only free fatty acids were converted to their methyl esters; esterified fatty acids, such as those in triglycerides and phospholipids, were not significantly transmethylated. This advantage eliminated the need for thin-layer chromatography for the separation of free and esterified fatty acids. The methyl esters of fatty acids were then extracted into isooctane and analyzed with a 10-meter glass capillary column coated with SP-2100. Splitless mode of injection was used to increase the sensitivity. Only 20 microliter or less of plasma was required for analysis. The coefficient of variation was 4.6%, which was better than the conventional gas-liquid chromatographic methods. These latter methods require 20 to 50 times larger samples, as compared with the present assay. This method is suitable for the measurement of both total free fatty acids and individual fatty acid patterns in small plasma samples.

Adult↗
PubMed2001

Role of tachykinin receptors in the central processing of afferent input from the acid-threatened rat stomach.

Noxious challenge of the rat gastric mucosa by hydrochloric acid (HCl) is signalled via vagal afferent neurons to several brain nuclei in which tachykinins and tachykinin receptors are present. Therefore, we tested whether tachykinin receptor antagonists would modify the central transmission of input from the acid-threatened stomach. Neuronal excitation was visualized by in situ hybridization autoradiography (ISH) of c-fos messenger ribonucleic acid (mRNA) 45 min after intragastric (IG) administration of HCl (0.5 M; 10 ml/kg). This stimulus has previously been shown to cause neurons in the nucleus tractus solitarii (NTS), lateral parabrachial nucleus (LPB), paraventricular (Pa) nuclei, supraoptic (SO) nucleus, central amygdala (CeA), area postrema (AP), subfornical organ (SFO) and habenula (Hb) to express c-fos mRNA. Intraperitoneal (IP) pretreatment with the NK1 receptor antagonist GR-205,171 (3 mg/kg) attenuated the acid-induced transcription of c-fos mRNA in NTS and augmented it in SFO. The NK2 receptor antagonist SR-144,190 (0.1 mg/kg, IP) had no effect. Subcutaneous administration of the NK3 receptor antagonist SB-222,200 (20 mg/kg) reduced the c-fos mRNA response in AP and SFO and enhanced it in Hb. These data show that the transmission of input from the acid-threatened stomach in distinct brain nuclei involves tachykinins acting at NK1 and NK3 receptors, but not NK2 receptors.

Afferent Pathways↗
PubMed1980

The effect of experimental acid aspiration on alveolar macrophage function in rabbits.

The effect of aspirated hydrochloric acid (HCl) on alveolar macrophage function was investigated in a rabbit model. Lung cells were obtained by bronchoalveolar lavage 4 h after an intratracheal injection of HCl. The intratracheal administration of HCl significantly increased (p < 0.005) the number of neutrophils recovered at lavage. Alveolar marcophage adherence to glass was significantly decreased (p < 0.001) in the HCl-treated animals compared with that of the control animals. Alveolar macrophage phagocytosis was not altered, and there was no effect on macrophage migration through micropore filters. In vitro studies showed that incubation of alveolar macrophages from normal rabbits in cell-free supernatants from HCl-treated rabbit lavage significantly decreased (p < 0.01) alveolar macrophage adherence to glass. In vitro incubation of alveolar macrophages from normal rabbits with rabbit peritoneal neutrophils significantly decreased (p < 0.05) adherence to glass. To investigate the effects of corticosteroid treatment, acid-injured rabbits were given 0.5 mg/kg of dexamethasone intravenously within 5 min. Alveolar macrophages from the steroid-treated animals showed a partial, but significant (p < 0.005), reversal of the acid-induced adherence defect. We concluded that acid aspiration is associated with an influx of neutrophils into the alveolar space, and decreased alveolar macrophage adherence to glass. The adherence defect was related to a factor or factors present in lavage fluid and to the presence of activated neutrophils. Corticosteriod treatment partially reversed the adherence defect.

Adhesiveness↗
PubMed1996

Delayed gastric emptying rate as a potential mechanism for lowered glycemia after eating sourdough bread: studies in humans and rats using test products with added organic acids or an organic salt.

The possible effects of organic acids or an organic salt on the rate of gastric emptying was studied to identify the cause for reduced postmeal responses of blood glucose and insulin to foods containing such components, eg, sourdough bread. Paracetamol was included in bread products with added lactic acid or sodium propionate and used as a marker for the rate of gastric emptying in healthy subjects. In parallel, postprandial glycemia, insulinemia, and satiety were evaluated. The influence of lactic acid, propionic acid, and sodium propionate was also studied in rats after they were tube-fed with glucose solutions. The bread products with lactic acid or sodium propionate both lowered blood glucose and insulin responses. The bread with sodium propionate also prolonged satiety. The reason for the lowered metabolic responses with sodium propionate was probably a lowered gastric emptying rate, as judged from reduced blood paracetamol concentrations; there was no such effect observed with bread with added lactic acid. A similar amount of lactic acid in solution tube-fed to rats did not affect the disappearance of glucose from the stomach. In contrast with the finding in humans, sodium propionate had no effect on the rate of gastric emptying in rats whereas an equimolar solution of propionic acid reduced gastric emptying rate in rats. Possibly, less of this acid was produced in the gastric contents after a bolus load of a sodium propionate solution (in rats) than in an eating situation. Also, the pH and/or the osmolarity may be important, and when provided in excessive amounts, lactic acid reduced the gastric emptying rate in rats. A hydrochloric acid solution of similar pH was much less effective in this respect.

Acetaminophen↗
PubMed1981

Flow cytometry analysis of lung cells from normal and acid-treated rabbits.

Lavaged lung cells from normal rabbits and rabbits given hydrochloric acid intratracheally were analyzed using flow cytometry techniques. The rabbit alveolar macrophage was characterized as a cell with relatively high light scatter and high intrinsic autofluorescence compared with the lung neutrophil with its lower light scatter and autofluorescence. The flow cytometry characteristics of these 2 cell populations were confirmed with light microscopy after cell sorting. A flow cytometry analysis of alveolar macrophage phagocytosis using fluorescent latex particles was applied to normal rabbit alveolar macrophages. These studies showed that flow cytometry can be used to study the morphologic features and function of rabbit lavage lung cell populations and may be ultimately useful in the analysis of human lung cells.

Animals↗
PubMed2006

An efficient method for extraction of astaxanthin from green alga Haematococcus pluvialis.

Haematococcus pluvialis is one of the potent organisms for production of astaxanthin, a high value ketocarotenoid. Astaxanthin is accumulated in thick-walled cyst cells of Haematococcus. The thick cell wall is made up of sporopollenin-like material, algaenan, which hinders solvent extraction of astaxanthin. In the present study, an improved method for extraction of astaxanthin without homogenization of cells is reported. Extractability of astaxanthin from cyst cells was evaluated by treating cells with various solvents and pretreating the cells with organic and mineral acids at 70 degrees C followed by acetone extraction. Hydrochloric acid treatment facilitated 86-94% extractability of astaxanthin. Treatment time, temperature, and concentration of the acid were found to be critical factors for maximum extractability. The treatment did not affect the astaxanthin ester profile and the treated cells can be preserved until further use.

Acetone↗
PubMed1991

Liquid chromatography-thermospray tandem mass spectrometry for identification of a heptabarbital metabolite and sample work-up artefacts.

An unknown heptabarbital metabolite, observed in the liquid chromatogram of rat plasma and urine samples after administration of heptabarbital, was identified by liquid chromatography-thermospray tandem mass spectrometry. By applying the parent scan mode for screening and the daughter scan mode for structure elucidation, the metabolite was determined to be 5-ethyl-5-(1'-, 3'- or 6'-cycloheptadienyl)barbituric acid. It was demonstrated that artefact formation occurred when hydrochloric acid was used for conjugate hydrolysis in the sample clean-up. Identification of the artefacts was achieved by the same method. Confirmation of the structures of the metabolite and the artefacts was obtained by gas chromatography-electron impact mass spectrometry.

Animals↗
PubMed1986

The effects of plasmapheresis and hemofiltration on canine acid aspiration pulmonary edema.

Aspiration of hydrochloric acid causes pulmonary capillary endothelial damage and edema. One approach to treatment is reduction of circulating volume and pulmonary wedge pressure (Ppw) to low values compatible with adequate cardiac output (QT) and oxygen delivery (QO2) to the tissues. We investigated this approach in 18 dogs after intratracheal instillation of HCl. One hour after injury, animals were randomized into 3 equal groups and studied for another 4 h. Control dogs (Group C) were maintained at a Ppw of 12 mmHg throughout the experiment. In a second group (Group H), Ppw was reduced over 30 min to 5 mmHg by hemofiltration and maintained at this amount throughout the experiment. In a third group (Group P) Ppw was reduced and maintained at 5 mmHg by plasmapheresis. In Group C, extravascular thermal volume (ETV), measured in vivo, increased to 520 ml by 5 h, and venous admixture (QVA/QT) increased to 30%. In contrast, plasmapheresis stopped ETV accumulation at the 1-h value of 250 ml, whereas QVA/QT decreased to 8% at 5 h. Hemofiltration did not significantly reduce either ETV or QVA/QT, which were 420 ml and 30%, respectively, at 5 h. The wet weights of lungs excised at 5 h and normalized to body weight (WW/BW) confirmed that plasmapheresis reduced edema (WW/BW, 19 ml/kg) compared (p less than 0.05 ANOVA) with that in the control group (WW/BW, 27), and that hemofiltration did not significantly reduce edema (WW/BW, 24).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Gastric acid in vertebrates.

Gastric secretion of hydrochloric acid appears to be unique to vertebrates and is almost ubiquitous in all fishes, amphibians, reptiles, birds and mammals. Comparative anatomy and physiology suggest that gastric acid has evolved approximately 350 million years ago. The similarity of the acid-secreting mechanism across all classes of vertebrates implies a major advantage for selection, but the evidence regarding its precise purpose remains inconclusive.

Animals↗
PubMed1979

The ocular hypertensive response following experimental acid burns in the rabbit eye.

Following application of 50 microliter of 2N hydrochloric acid to the rabbit cornea, the intraocular pressure rapidly increases and remains markedly elevated for up to 3 hr. The initial rapid increase in intraocular pressure appears to be the result of acid-induced shrinkage of the outer collagenous coats of the eye. The sustained rise in intraocular pressure is mediated in part by prostaglandin release. Increased prostaglandin-like activity, determined in the aqueous after an acid burn, was greatly inhibited by pretreatment of rabbits with indomethacin and to a much lesser extent by pretreatment with imidazole. Both indomethacin and imidazole essentially abolished the sustained elevation of intraocular pressure after an acid burn. Analysis of changes in pH and protein level in the aqueous implies that the stimulus for prostaglanding release within the eye is the penetration of hydrogen ions into the aqueous humor, with resultant intraocular trauma.

Animals↗