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Biomedical subjects

A Furka

Publications and source records attributed to A Furka.

15 recordsLinked to original sources
PubMed2000

Causes of death of patients with multiple injuries in Debrecen, Hungary.

OBJECTIVE: To find out the main causes of death of people who had multiple severe injuries. DESIGN: Retrospective study. SETTING: Teaching hospital, Hungary. SUBJECTS: 86 people with severe multiple injuries, of whom 59 died and had necropsies. MAIN OUTCOME MEASURE: Establishment of a database. RESULTS: Consumption of alcohol was a common precursor. Head and chest injuries predominated. More pedestrians than people in vehicles were killed, and there were 8 suicides and 3 murders. There were no gunshot injuries. CONCLUSIONS: Reduction of deaths from multiple injuries is as much a socioeconomic as a medical matter.

Alcohol Drinking↗
PubMed2000

Redistribution in combinatorial synthesis. A theoretical approach.

In modified versions of the split-mix method, the conventional solid support resin was replaced by labeled macroscopic support units in order to produce individual compounds in multi milligram quantities while the high productivity of the original procedure is preserved. Recently it has also been shown that tagging the units is unnecessary. Omission of the tags is possible if (i) the unlabeled support units are arranged into spatially ordered groups and the relative spatial arrangement of the units is maintained during the chemical reactions (ii) the support units are redistributed between the reaction steps according to a predetermined pattern permitted by the combinatorial redistribution rule and (iii) the sorting process is simulated by a computer that can trace the synthetic history of each support unit. Different kinds of solid support units, formation of spatially ordered groups, sorting devices and basic redistribution patterns (serial, semi-parallel and parallel) are discussed. It is also shown that particularly the semi-parallel and the parallel redistribution assure fast sorting.

Combinatorial Chemistry Techniques↗
PubMed1999

Combinatorial libraries by portioning and mixing.

Combinatorial chemistry--due to its radically new synthetic methods--can be considered a forerunner of chemistry in the next century. One of the most important methods is the portioning-mixing (split-mix) synthesis which embodies the combinatorial principle. It is easily realized. Both manual and automatic devices have been described. Some features that contribute to its popularity include: it produces all possible structural combinations of the monomers, it has outstanding productivity, it leads to the formation of individual compounds in nearly equimolar quantities (affected by statistics and incomplete reactions), and it can be applied to all classes of organic compounds. Since an enormously large number of compounds can be produced in principle in a relatively short time, some practical considerations are discussed that can be useful in library design. Encoding organic libraries by peptide or nucleotide sequences or with binary tags are also described together with methods for tagging macroscopic support units with electronic chips, two dimensional bar codes or colored resin and capsule caps. Among the deconvolution strategies, the iteration method, positional scanning, omission libraries, the Selectide and the Pharmacopeia methods are mentioned. A collection of libraries prepared by portioning-mixing is also included in graphical format.

Organic Chemicals↗
PubMed1998

Deconvolution by omission libraries.

Omission libraries, synthesized by omitting one amino acid in all coupling positions, are very efficient tools for the rapid identification of the amino acid components of bioactive peptides. Based on the determined amino acids, an occurrence library can be defined and prepared which is much less complex than the full one while still comprising the bioactive peptide.

Amino Acid Sequence↗
PubMed1998

Coloured peptides: synthesis, properties and use in preparation of peptide sub-library kits.

Several methods were developed for the solid-phase synthesis (SPPS) of coloured peptides and peptide libraries. At first a bifunctional red compound, 4-(4-(N-ethyl-N-(3-(tert-butyloxycarbonyl)aminopropyl)amino)phenylazo)be nzoic acid (Boc-EPAB), was coupled with chloromethyl resin to obtain a new solid support suitable for SPPS using Boc chemistry. Peptides synthesized on this coloured resin had the chromophore at their C-termini. N-terminally coloured peptides were synthesized on a traditional solid support, coupled with chromophoric carboxylic acid before cleavage. A model pentapeptide, Phe-Ala-Val-Leu-Gly, and its ten derivatives were synthesized and their properties studied. It was found that the presence of chromophores decreases the water solubility of peptides. However, insertion of solubilizing tags (penta-lysine sequences or polyoxyethyl chains) into the molecule of any coloured derivative resulted in enhancement of the solubility. The RP-HPLC hydrophobicity indexes (phi0) of the coloured peptides were also determined because phi0 values are closely related to their water solubility. A coloured pentapeptide library was synthesized using the portioning-mixing method. Each component of this library contained the red azo dye (EPAB) and the penta-lysine tag. Before the last coupling step the samples were not mixed. All of the 19 sub-libraries obtained after cleavage were readily soluble in water, giving intense red solutions. The effect of chromophore (EPAB) and/or penta-lysine solubilizing tag on the biological activity was also studied. Potencies of the bovine neurotensin 8-13 fragment and its different coloured and penta-lysine derivatives were compared in isolated longitudinal muscle strips of guinea pig ileum. It was shown that the hexapeptide with penta-lysine tag had almost the same activity as the 8-13 fragment itself. The activity of the EPAB-derivative was found to be rather low. However, the presence of the solubilizing tag in the coloured hexapeptide compensated the negative effect of the chromophore.

Aminobenzoates↗
PubMed1991

General method for rapid synthesis of multicomponent peptide mixtures.

A method is suggested for the synthesis of multicomponent peptide mixtures. The method is a solid phase synthesis modified in order to give a closely equimolar mixture of peptides with predetermined sequences. The main point of modification is that before every coupling cycle the resin is divided into equal parts and each portion is coupled with a different amino acid. Then the portion are mixed and before the next coupling cycle the resin is again distributed into equal portions. The method is illustrated by the synthesis of a mixture of 27 tetrapeptides and that of 180 pentapeptides.

Amino Acid Sequence↗
PubMed1983

An improved method for isolation of the C-terminal fragment of proteins.

An efficient and easily realizable method for the isolation of the C-terminal fragment is described. Proteins are esterified by methanolic HCl and subsequently digested with pepsin. The peptide mixture is submitted to paper electrophoresis in pH 2.1 buffer. The identification of the C-terminal peptide is performed by preparing a guide peptide map, using pH 5.5 buffer in the second dimension. The C-terminal fragment appears as an on-diagonal spot. It can be isolated by a pH 5.5 run of the corresponding band from the first (pH 2.1) electrophoretogram. Since the C-terminal peptide is the fastest moving component, there is no need for its further purification. The expected yield is about 40%.

Amino Acid Sequence↗
PubMed1980

Synthesis of gamma-L-glutamyl-taurine.

Glu(Tau), a bioactive substance previously isolated from the protein free aqueous extract of bovine parathyroid powder, has been synthesized. The intermediate derivative Z-Glu(Tau)-OBzl was prepared in three different ways from Z-Glu-OBzl and (1) cystamine by using the mixed anhydride method followed by oxidation, (2) Tau by the active ester procedure via Z-Glu-(ONp)-OBzl, (3) Tau applying mixed anhydride coupling. The protecting groups were removed by hydrogenolysis.

Animals↗
PubMedDate not supplied

Binary synthesis of multicomponent peptide mixtures by the portioning-mixing technique.

By introducing a new operation (non-coupling), our portioning-mixing method has become suitable for preparing binary peptide libraries. We demonstrate that all the expected components of a simple library are present in the mixture. The number of components in such libraries, the molar ratio of peptides as well as the possibilities of screening are discussed.

Amino Acid Sequence↗