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F Marquard

Publications and source records attributed to F Marquard.

3 recordsLinked to original sources

Versatile high-performance liquid chromatographic computer system for solvent delivery, gradient control and data acquisition using the Commodore 64 personal computer.

An interface for a high-performance liquid chromatographic system based on the Commodore 64 personal computer has been designed as an alternative to the expensive and somewhat inflexible solvent programmers and data acquisition systems offered by commercial manufacturers. The system consists of the Commodore 64 with a single disk drive and monitor, and an interface that directly controls the flow-rates of two Waters pumps for solvent delivery in either isocratic or gradient mode, as well as analog-to-digital conversion of chromatographic data and either graphic data output to a dot-matrix printer or digital-to-analog conversion for output to a chart recorder. The interface permits computer-controlled flow-rates of up to 10.0 ml/min, with an accuracy of 0.0047 ml/min at flow-rates of 4.1 ml/min and an accuracy of 0.03 ml/min at flow-rates of 10 ml/min. The software for data analysis permits tabulation of elution times and areas for the peaks in a chromatogram with an option for baseline correction. The data are stored on floppy disks together with information pertinent to the chromatogram (flow-rate, solvent composition, etc.).

Chromatography, High Pressure Liquid↗

Murine monoclonal antibodies and human alloantisera specific for HLA inhibit monocyte phagocytosis of anti-D-sensitized human red blood cells.

Evidence is presented that monoclonal antibodies (mAb) against some human major histocompatibility complex (MHC) gene products and human sera containing HLA antibodies strongly inhibit immune phagocytosis of anti-D-sensitized red blood cells by human monocytes. w6.32HL, a mAb against a monomorphic class I antigen of high cell surface density, revealed the strongest inhibition among mAb reactive with MHC class I products. mAb with preferential reactivity for monomorphic and polymorphic DR and DQ epitopes (L203, L227, IIIE3, Tü22, Genox 3.53 and IV12) were noninhibitory. Definite inhibition was also apparent with a mAb against DRw52/MT2 (I-LR2) and with an antibody to class II antigens of high cell surface density (2MC3). Human sera containing HLA antibodies showed strong inhibition of immune phagocytosis up to a dilution of 1/1000. This inhibition could not be abrogated by platelet absorption. This indicates that human sera inhibiting immune phagocytosis may comprise at least two types of antibodies: cytotoxic HLA-specific antibodies which may or may not be inhibitory, and inhibitory antibodies against monocytic antigens not necessarily cytotoxic. These latter antibodies may recognize HLA DR or another as yet undefined gene product within, or closely associated to, the human MHC.

Antibodies, Monoclonal↗

Home parenteral nutrition in a patient with Crohn's disease. A case report.

Total parenteral nutrition (TPN) carried out by the patient at home is a new concept in the treatment of intestinal failure. We describe a patient with Crohn's disease who has extensive involvement of the small intestine with resultant severe malabsorption, and who was therefore treated with 'home' TPN for 4 months. During this treatment there were no serious complications. The disabling symptoms present before hyperalimentation was commenced disappeared, and overall clinical improvement has been maintained for a further 6 months after TPN therapy. This case illustrates the feasibility of safe TPN at home in selected patients who have access to specialized hyperalimentation units.

Adult↗