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Biomedical subjects

H M Fales

Publications and source records attributed to H M Fales.

At least 73 records · Page 4Linked to original sources
PubMed1986

Purification of a benzodiazepine from bovine brain and detection of benzodiazepine-like immunoreactivity in human brain.

An endogenous brain substance that binds to the central-type benzodiazepine receptors with agonist properties is present in both rat and bovine brains. This substance has been purified to homogeneity from bovine brain by immunoaffinity chromatography on immobilized monoclonal anti-benzodiazepine antibody followed by gel filtration on Sephadex G-25 and two reversed-phase HPLC steps. The purified substance was characterized as the benzodiazepine N-desmethyldiazepam (nordiazepam). The techniques used for the identification were mass spectrometry, HPLC, spectrophotometry, benzodiazepine receptor binding, and immunological techniques. Benzodiazepine-like immunoreactivity was also found in all the human brains tested, including six brains that had been stored in paraffin since 1940, fifteen years before the first synthesis of benzodiazepines. These results show that benzodiazepine-like molecules of natural origin--and possibly benzodiazepines themselves--are present in human and other mammalian brains.

Animals↗
PubMed1984

Alternative adherence marker schemes.

Various possible adherence markers are mentioned, including inert particulate matter, soluble and insoluble dyes, polymer attached dyes, spin-labeled substances, and radioactive and stable isotope tracers. Methods for detection might include nuclear magnetic resonance (NMR), electron spin resonance (ESR), x-ray, gas chromatography, and simple fluorescence or absorption. Emphasis is placed on systems involving safety, reliability, and redundancy. No clear-cut superiority of any method is apparent.

Humans↗
PubMed1980

Metabolism of putrescine to 5-hydroxy-2-pyrrolidone via 2-pyrrolidone.

Incubation of 2-[14C]pyrrolidone with sliced rat liver and analysis of the incubation medium by silica gel chromatography revealed that 2-[14C]pyrrolidone is metabolized to an unknown. It was previously shown by Lundgren and Hankins ((Lundgren, D.W, and Hankins, J. (1978) J. Biol. Chem. 253, 7130-7133) that slices of rat liver readily synthesized 2-pyrrolidone from putrescine. The unknown metabolite was partially purified by methanol/chloroform extraction, activated charcoal column chromatography, and two-dimensional thin layer chromatography on silica gel plates. The 2-pyrrolidone metabolite was derivatized with bis(trimethylsilyl)trifluroacetamide and analyzed by gas chromatography-mass spectrometry. The mass of the molecular ion (245) and fragment ions suggests that the 2-pyrrolidone metabolite is 5-hydroxy-2-pyrrolidone. The mass spectrum of synthetic 5-hydroxy-2-pyrrolidone was identical to that of the unknown metabolite. Synthetic 5-hydroxy-2-[3H]pyrrolidone co-chromatographed on silica gel sheets with the unknown 2-[14C]pyrrolidone metabolite obtained directly from incubation media. Under appropriate conditions (pH 7.5, no acid treatment of medium), putrescine is metabolized to 5-hydroxy-2-pyrrolidone via 2-pyrrolidone. Several effector compounds, but not necessarily the same ones, inhibit or enhance, or both, the conversion of putrescine to 2-pyrrolidone and of 2-pyrrolidone to 5-hydroxy-2-pyrrolidone. This is the first demonstration of the biosynthesis of 5-hydroxy-2-pyrrolidone.

Animals↗
PubMed1980

Human alveolar macrophage-derived chemotactic factor for neutrophils. Stimuli and partial characterization.

The presence of neutrophils within the lung is a characteristic feature of a variety of lung diseases. To evaluate the potential role of alveolar macrophages in modulating the migration of neutrophils to the lung, normal human alveolar macrophages obtained from volunteers by bronchopulmonary lavage, were exposed for various periods of time in vitro to heat-killed microorganisms, and noninfectious particulates, immune complexes, and the macrophage supernates were evaluated for chemotactic activity. The microorganisms, noninfectious particulates, and immune complexes were chosen as stimuli for alveolar macrophages because these stimuli are representative of a spectrum of pathogenic agents that cause neutrophil accumulation in the lower respiratory tract. After incubation with each of these stimuli, alveolar macrophages released low molecular weight (400-600) chemotactic factor(s) (alveolar macrophage-derived chemotactic factor[s] [AMCF]) with relatively more activity for neutrophils than monocytes or eosinophils. Checker-board analysis of the AMCF revealed that the factor was primarily chemotactic and not chemokinetic for neutrophils. The selectivity for neutrophils vs. monocytes could not be explained by a selective deactivation of monocytes, because the AMCF was more potent in deactivating neutrophils than monocytes. Partial characterization of AMCF demonstrated it was heterogeneous with the following features: (a) stable to heating at 56 and 100 degrees C for 30 min; (b) stable over a pH range of 1.0 to 12.0 for 60 min; (c) stable after exposure to trypsin, papain, chymotrypsin, collagenase, and elastase; (d) partially inhibited by serum chemotactic factor inhibitor(s); (e) two major isoelectric points (pI 7.6 and 5.2); and (f) partially extractable into ethyl acetate, ether, and hexane. Although AMCF was, at least, partially lipid in nature, it did not appear to be similar to previously described lipid chemotactic factors (e.g., hydroxy-derivatives of 5,8,10,14-eicosatetraenoic acid); analysis by gas chromatography-mass spectrophotometry of AMCF extracted into ethyl acetate did not reveal the presence of 5,8,10,14-eicosatetraenoic acid. The macrophage supernates containing the AMCF also stimulated normal human neutrophils to release lysozyme and lactoferrin but not lactate dehydrogenase. These studies suggest that a wide variety of potentially pathogenic stimuli induce normal alveolar macrophages to generate a low molecular weight chemotactic factor(s) that preferentially attracts neutrophils. Because alveolar macrophages are normal residents of alveoli, it is likely that by releasing this factor(s) macrophages play a significant role in amplifying the inflammatory processes seen in many acute and chronic lung diseases.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1977

Isolation and characterization of a unique galactoside from male Drosophila melanogaster.

A ninhydrin-positive compound with presumptive hormonal activity, previously considered to be a peptide (Chen, P.S., and Bühler, R. (1970), J. Insect Physiol. 16, 615), has been isolated from adult male Drosophila melanogaster. Chromatographic analysis of the acid-hydrolyzed material revealed the presence of ethanolamine, phosphorus, galactose, and glycerol. Chemical analysis showed these to be present in equimolar amounts. Based on its phosphorus content, the nonreducing material took up 2 equiv of periodate, and released 1 equiv of formaldehyde. Characterization of the compound as 1-O-(4-O-(2-aminoethyl phosphate)-beta-D-galactopyranosyl)-x-glycerol was achieved by gas chromatography-mass spectroscopy and 1H and 31P NMR using model compounds. In vivo synthesis from labeled precursors is in accord with the proposed structure.

Animals↗
PubMed1976

Formation of glutathione conjugates of prostaglandin A1 in human red blood cells.

When prostaglandin A1 was incubated with a Tris/saline suspension of washed human red blood cells, a substantial amount was converted to polar metabolites. These were purified by solvent extraction, XAD-2 column, and cellulose thin layer chromatography and characterized by chromatography, amino acid analysis, and mass spectrometry. The polar metabolites were a mixture of two glutathione conjugates of prostaglandin A1. The first (approximately 40%) was identical with the product of the nonenzymic reaction of glutathione with prostaglandin A1. The second (approximately 60%) was formed from the first by reduction of the 9-keto group of the prostaglandin moiety. The latter compound was also prepared synthetically by treating the glutathione conjugate of prostaglandin A1 with sodium borohydride.

Erythrocytes↗
PubMed1975

Chemical structure and purity of dyes used in lymphograms.

Because of confusion in the literature, studies were performed on several samples of patent blue violet and Alphazurine 2G to determine their chemical structure and purity. Nuclear magnetic resonance studies revealed that three distinct compounds and one mixture had all been labeled as the same compound. The purity of the dyes varied from batch to batch, as shown by thin-layer chromatography. Caution should be exercised in the use of these dyes for lymphograms.

Chemical Phenomena↗
PubMed1975

Accumulation of oxygenated steryl esters in Wolman's disease.

7alpha- and 7beta-hydroxycholesteryl esters, 7-ketocholesteryl esters, and 5,6alpha- and 5,6beta-epoxycholesteryl esters have been identified in tissues of patients affected by Wolman's disease. Their structural identities were determined by mass spectroscopy and nuclear magnetic resonance spectroscopy and confirmed by chemical synthesis. It is postulated that cholesteryl ester hydrolase deficiency in Wolman's disease might lead to accumulation of oxygenated steryl esters in vivo and impairment of bile acid formation.

Adrenal Glands↗