Search PubMed⌕ Search

Biomedical subjects

D Hochstrasser

Publications and source records attributed to D Hochstrasser.

35 records · Page 2Linked to original sources
PubMed1992

Red blood cell protein map: a comparison between carrier-ampholyte pH gradient and immobilized pH gradient, and identification of four red blood cell enzymes.

The aim of this study was (a) to establish a red blood cell (RBC) protein map with immobilized pH gradient for the first dimension (b) to compare the pattern with previously published RBC protein map obtained with carrier-ampholyte pH gradients and (c) to localize four new enzymes on the map (i.e. 6-phosphogluconic dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutathione peroxidase and superoxide dismutase). This publication provides the most updated RBC polypeptide pattern with twelve proteins or enzymes localized on the map.

Blood Protein Electrophoresis↗
PubMed1991

Preparative isoelectrofocusing and high resolution 2-dimensional gel electrophoresis for concentration and purification of proteins.

We have analysed the potential of liquid phase isoelectrofocusing allied to high resolution 2-dimensional gel electrophoresis for concentrating and purifying in particular plasma proteins present in low concentrations. The primary fractionation step, liquid phase isoelectrofocusing, offers several advantages. Firstly, it allows protein profiles to be examined within defined pH ranges. Additionally, it confines the bulk plasma proteins to their respective pI ranges, allowing larger quantities of protein to be employed for the second fractionation phase. Concurrently, it concentrates proteins present at low concentrations, also by restricting them to their pI ranges. Yields are such that detailed characterisation studies of the proteins can be undertaken, providing the means of generating comprehensive data banks to complement plasma protein maps. The procedure should be applicable to a wide range of biological fluids and tissues.

Blood Proteins↗
PubMed1988

Automatic classification of two-dimensional gel electrophoresis pictures by heuristic clustering analysis: a step toward machine learning.

The interpretation of two-dimensional gel electrophoresis (2-DGE) profiles can be facilitated by artificial intelligence and machine learning programs. We have incorporated into our 2-DGE computer analysis system (termed MELANIE-Medical Electrophoresis Analysis Interactive Expert system) a program which automatically classifies 2-DGE patterns using heuristic clustering analysis. This program is a step toward machine learning. In this publication, we describe the classification method and the preliminary results obtained with liver biopsy electrophoretograms. Heuristic clustering is also compared to other classification techniques.

Algorithms↗
PubMed1988

"High-resolution" mini-two-dimensional gel electrophoresis automatically run and stained in less than 6 h with small, ready-to-use slab gels.

Although two-dimensional (2-D) gel electrophoresis is one of the most powerful techniques for analyzing protein mixtures, its application in routine clinical laboratories is currently limited, because it is time-consuming, complex, and relatively expensive. Here we describe a method for automatically running and staining "high-resolution" mini 2-D electrophoresis gels in less than 6 h, by using "ready-to-use" slab gels and a PhastSystem electrophoresis apparatus. We present 2-D gel electrophoretograms of 25 nL of plasma, as well as their automatic computer analysis. For comparison, a conventional 2-D gel electrophoresis profile of 200 nL of a plasma sample is shown. The technique is easy to perform, highly sensitive, rapid, and potentially useful in semi-routine clinical chemistry laboratories.

Autoanalysis↗
PubMed1988

Protein heterogeneity of lipoprotein particles containing apolipoprotein A-I without apolipoprotein A-II and apolipoprotein A-I with apolipoprotein A-II isolated from human plasma.

The protein heterogeneity of fractions isolated by immunoaffinity chromatography on anti-apolipoprotein A-I and anti-apolipoprotein A-II affinity columns was analyzed by high resolution two-dimensional gel electrophoresis. The two-dimensional gel electrophoresis profiles of the fractions were analyzed and automatically compared by the computer system MELANIE. Fractions containing apolipoproteins A-I + A-II and only A-I as the major protein components have been isolated from plasma and from high density lipoproteins prepared by ultracentrifugation. Similarities between the profiles of the fractions, as indicated by two-dimensional gel electrophoresis, suggested that those derived from plasma were equivalent to those from high density lipoproteins (HDL), which are particulate in nature. The established apolipoproteins (A-I, A-II, A-IV, C, D, and E) were visible and enriched in fractions from both plasma and HDL. However, plasma-derived fractions showed a much greater degree of protein heterogeneity due largely to enrichment in bands corresponding to six additional proteins. They were present in trace amounts in fractions isolated from HDL and certain of the proteins were visible in two-dimensional gel electrophoresis profiles of the plasma. These proteins are considered to be specifically associated with the immunoaffinity-isolated particles. They have been characterized in terms of Mr and pI. Computer-assisted measurements of protein spot-staining intensities suggest an asymmetric distribution of the proteins (as well as the established apolipoproteins), with four showing greater prominence in particles containing apolipoprotein A-I but no apolipoprotein A-II.

Apolipoprotein A-I↗
PubMed1988

HDL particle associated proteins in plasma and cerebrospinal fluid: identification and partial sequencing.

The proteins from plasma HDL particles isolated by immunoaffinity chromatography on anti-apolipoprotein A-1 affinity columns have been analysed and purified by high resolution two dimensional gel electrophoresis. Two of the lipoprotein-associated proteins found in the HDL plasma fraction, previously referred to as NA1 and NA2, have also been found in cerebrospinal fluid. After separation by 2DGE, these two proteins were transferred to PVDF membranes, stained and cut out for N-terminal sequencing. The partial sequences (11 and 13 amino acids) obtained for the two HDL particle associated proteins do not match any of those included in the December 1987 National Biomedical Research Foundation (NBRF) database, and there are no significant sequence similarities.

Amino Acid Sequence↗
PubMed1986

[Protein mapping of normal circulating cells: lymphocytes and monocytes].

Purified lymphocyte and monocyte populations were obtained from peripheral blood cells by ficoll-hypaque gradient and elutriation in different normal individuals. The two types of mononuclear cells were then analyzed by 2-dimensional gel electrophoresis. More than 1,000 spots were detected by our computer system and analyzed for each cell type. Automatic picture comparison showed a typical pattern for the two different populations with excellent reproducibility.

Blood Protein Electrophoresis↗
PubMed1986

[Thrombotic thrombocytopenic purpura treated with prostacyclin. Apropos of 2 case reports].

The syndrome of thrombotic thrombocytopenic purpura (TTP) has an uncertain course, is often fatal, and its pathogenesis is obscure. None of the treatments suggested is of proven efficacy. Two cases of TTP are reported with a favourable outcome probably due to continuous intravenous perfusion of prostacyclin combined with antiplatelet drugs for several days, after steroids, plasmapheresis and fresh plasma had failed. The two patients are at present in complete remission after 8 and 20 months under prophylactic treatment with salicylate and dipyridamole.

Adult↗
PubMedDate not supplied

Multimedia image and data navigation workstation.

World Wide Web (WWW) standards have been established for the transmission of and remote consultation on medical information and records, including medical images, extracted from an existing hospital information system. A software package called Osiris is being used for the display and manipulation of medical images in a hospital-based picture archiving and communication system. Recent extensions of Osiris, through the integration of WWW navigational tools, allow easy access to a variety of clinical data from patient records. A special interface allows access to radiologic images, laboratory results, and related textual information through public-domain software programs. These technologic advances offer medical professionals the convenience and ease of use that have made WWW and Internet navigation so popular in the academic community.

Computer Communication Networks↗
PubMedDate not supplied

Characterization of a human high density lipoprotein-associated protein, NA1/NA2. Identity with SP-40,40, an inhibitor of complement-mediated cytolysis.

Two peptides, NA1 and NA2, which we previously suggested to be associated with high density lipoproteins (HDLs), have been purified. Polyclonal antibodies against each peptide and a monoclonal antibody against NA2 have been used to further characterize them and their association with HDL. Immunoblotting studies revealed that the peptides form a complex of molecular mass of approximately 80 kd. Agarose gel filtration showed coelution of NA1/NA2 and apolipoprotein (apo) A-I, the structural protein of HDL. This was confirmed by fast protein liquid chromatography, which further indicated that up to 60% of NA1/NA2 was located within the lower density range of the HDL spectrum. Complementary studies with anti-apo A-I immunoaffinity columns provided evidence that at least 40% of NA1/NA2 was associated with HDL, an association easily disrupted by ultracentrifugal manipulation. Finally, partial amino acid sequences showed virtually complete homology with a recently identified protein, SP-40,40, or cytolysis inhibitor. The protein is suggested to have a powerful inhibitory effect on complement-mediated cell lysis. Our results could thus furnish an explanation for the previously observed modulating influence of HDL on complement activity.

Amino Acid Sequence↗
PubMedDate not supplied

An integrated hospital information system in Geneva.

Since the initial design phase from 1971 to 1973, the DIOGENE hospital information system at the University Hospital of Geneva has been treated as a whole and has retained its architectural unity, despite the need for modification and extension over the years. In addition to having a centralized patient database with the mechanisms for data protection and recovery of a transaction-oriented system, the DIOGENE system has a centralized pool of operators who provide support and training to the users; a separate network of remote printers that provides a telex service between the hospital buildings, offices, medical departments, and wards; and a three-component structure that avoids barriers between administrative and medical applications. In 1973, after a 2-year design period, the project was approved and funded. The DIOGENE system has led to more efficient sharing of costly resources, more rapid performance of administrative tasks, and more comprehensive collection of information about the institution and its patients.

Computer Systems↗