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Biomedical subjects

R A Hoffmann

Publications and source records attributed to R A Hoffmann.

13 recordsLinked to original sources
PubMed2001

Oral misoprostol vs. placebo in the management of prelabor rupture of membranes at term.

OBJECTIVE: To evaluate the efficacy of oral misoprostol for the induction of labor (IOL) in women with prelabor rupture of membranes at term (PROM) and to monitor maternal or fetal complications. METHOD: This randomized, placebo controlled trial was performed in a secondary referral hospital. The data of 47 patients in the misoprostol--and 49 patients in the placebo group was available for analysis. The former received 100 microg misoprostol orally, repeated once after 6 h if not in active labor, the latter received two doses of vitamin C also after a 6-h interval. The Mann-Whitney U-test was used for analysis. RESULTS: The median treatment to delivery interval in the misoprostol group was 7.5 h and 25 h in the placebo group (P<0.001). No significant differences were found in the incidence of abnormalities on the cardiotocograph, mode of delivery, neonatal outcome, use of antibiotics for the mothers and patient acceptability. CONCLUSION: Oral misoprostol in the suggested dose is an effective and cheap alternative for IOL in patients with PROM. No adverse effects could be demonstrated.

Administration, Oral↗
PubMed1995

1H- and 13C-NMR characterization of the digalactosylmannopentaose liberated from legume seed galactomannan by beta-mannanase action.

Incubation of Locust bean gum with an Aspergillus niger beta-D-mannanase released a wide variety of galactomannan oligomers. A single heptasaccharide, digalactosylmannopentaose, was obtained from fractionation of the mixture by size exclusion chromatography. The purity and chemical composition of the sample was demonstrated using mass spectrometry, high performance anion-exchange chromatography and monosaccharide composition analysis. The primary structure of this heptasaccharide was unambiguously identified using 2D 1H and 13C homonuclear and heteronuclear NMR. A complete assignment of the 1H and 13C signals of this oligomer was achieved, producing an NMR dataset that will be of importance in the primary structure elucidation of larger and more complex galactomannan oligomers.

Aspergillus niger↗
PubMed1994

Structures of small oligomers liberated from barley arabinoxylans by endoxylanase from Aspergillus awamori.

Arabinoxylans consisting of more than 90% of arabinose and xylose were extracted from water-insoluble cell wall material of dehusked barley grain, and degraded with a purified endo-(1-->4)-beta-D-xylanase from Aspergillus awamori. Twelve of the oligosaccharide fragments released were isolated by a combination of size-exclusion and anion-exchange chromatography, and their structures were determined by 1H NMR spectroscopy. The oligosaccharides identified consisted of (1-->4)-linked beta-D-xylopyranosyl residues, some of which were substituted at O-2, at O-3, or at both O-2 and O-3, with alpha-L-arabinofuranosyl groups. Two new structures, a tetrasaccharide and a pentasaccharide, both containing terminal 2-O-arabinofuranosylxylopyranose as a structural element are described.

Arabinose↗
PubMed1993

Characterisation by 1H NMR spectroscopy of oligosaccharides derived from alkali-extractable wheat-flour arabinoxylan by digestion with endo-(1-->4)-beta-D-xylanase III from Aspergillus awamori.

Alkali-extractable wheat-flour arabinoxylan, treated with endo-(1-->4)-beta-D-xylanase III from Aspergillus awamori CMI 142717, was fractionated by Bio-Gel P-2 size exclusion chromatography at 60 degrees C. Column fractions, corresponding to oligosaccharides with degrees of polymerisation from 5 to 10, were collected, and subfractionated by high performance anion-exchange chromatography on CarboPac PA-1. The structures of the oligosaccharides thus obtained were elucidated by 1H NMR spectroscopy, showing chains of (1-->4)-linked beta-D-xylopyranosyl residues differently substituted at O-3 and/or O-2,3 with alpha-L-arabinofuranosyl groups. The structures were different from those obtained with endo-(1-->4)-beta-D-xylanase I of the same xylanolytic enzyme system.

Alkalies↗
PubMed1992

1H-N.m.r. study of enzymically generated wheat-endosperm arabinoxylan oligosaccharides: structures of hepta- to tetradeca-saccharides containing two or three branched xylose residues.

The structures of hepta- to tetradeca-saccharides, generated by digestion of wheat-endosperm arabinoxylan with endo-(1----4)-beta-D-xylanase, and isolated by gel-permeation chromatography on Bio-Gel P-6 and high-performance anion-exchange chromatography with pulsed amperometric detection (h.p.a.e.-p.a.d.), were elucidated using monosaccharide and methylation analysis, f.a.b.-m.s., and 1H-n.m.r. spectroscopy. The structures identified had two branching elements, ----4)[alpha-L-Araf-(1----3)]-beta-D-Xylp-(1---- and/or ----4) [alpha-L-Araf-(1----2)][alpha-L-Araf-(1----3)]-beta-D-Xyl p-(1----, directly connected to each other in all four possible combinations. The h.p.a.e.-p.a.d. elution pattern showed that these combinations are not present in equal amounts. Also, compounds containing two 2,3-branched beta-D-Xylp residues separated by one or two unbranched beta-D-Xylp residues were found, and the presence of a tetradecasaccharide containing three 2,3-branched beta-D-Xylp residues was established.

Arabinose↗
PubMed1991

Characterisation by 1H-n.m.r. spectroscopy of oligosaccharides, derived from arabinoxylans of white endosperm of wheat, that contain the elements ----4)[alpha-L-Araf-(1----3)]-beta-D-Xylp-(1---- or ----4)[alpha- L-Araf-(1----2)][alpha-L-Araf-(1----3)]-beta-D-Xylp-(1----.

The structure of penta- to hepta-saccharides, generated by digestion of purified wheat-endosperm arabinoxylan with endo-(1----4)-beta-D-xylanase and isolated by gel-permeation chromatography on Bio-Gel P-6 followed by high-performance anion-exchange chromatography with pulsed amperometric detection, was established using monosaccharide and methylation analysis, f.a.b.-m.s., and 1H-n.m.r. spectroscopy. The oligosaccharides had a core of (1----4)-linked beta-D-xylopyranosyl residues 3- or 2,3-substituted with single alpha-L-arabinofuranosyl groups, and gave 1H-n.m.r. spectra typical for each type.

Chromatography↗
PubMed1991

Characterisation of polysaccharides by in-source pyrolysis positive- and negative-ion direct chemical ionisation-mass spectrometry.

Series of oligosaccharide ions have been generated from a range of polysaccharides by the application of in-source pyrolysis mass spectrometry, using both ammonia positive-ion chemical ionisation and negative-ion chlorine-nucleophilic-addition ionisation. Glucans with alpha-(1----6), beta-(1----6), alpha-(1----4), beta-(1----4), beta-(1----3), and beta-(1----2) linkages were studied, together with pentosans, xyloglucans, and an arabinogalactan. The series of ions correspond to intact, desorbed oligosaccharides with a terminal anhydro-sugar unit, and to similar oligosaccharides with attached sugar ring-cleavage fragments. The ions generated are dependent on the position of the linkage and ring size, and retain significant information on the structure of the original polysaccharide.

Carbohydrate Sequence↗
PubMed1975

Pneumoperitoneography: a special radiological technic used in nonhuman primate medicine.

Visualization of abdominal structures was difficult in survey radiographs of nonhuman primates due to the paucity of intra-abdominal fat and the presence of gastrointestinal contents. Simple pneuoperitoneography combined with contrast gastrointestinal studies provided valuable information, ie, size, shape, and position, of abdominal structures. After ip injection of carbon dioxide, a series of positional radiographs were exposed to delineate the various abdominal organs. The positioning device used in the examination was illustrated and described and the clinical indications and diagnostic value of pneumoperitoneography discussed.

Animals↗