Intuitive teaching of medical device operation to clinical assistance robots.

Purpose: The adjustment of medical devices in the operating room is currently done by the circulating nurses. As digital interfaces for the devices are not foreseeable in the near future and to incorporate legacy devices, the robotic operation of medical devices is an open topic.

Methods: We propose a teleoperated learning from demonstration process to acquire the high-level device functionality with given motion primitives.

Dipolar Interactions and Protein Hydration in Highly Concentrated Antibody Formulations.

Molecular interaction mechanisms in high-concentrated protein systems are of fundamental importance for the rational development of biopharmaceuticals such as monoclonal antibody (mAb) formulations. In such high-concentrated protein systems, the intermolecular distances between mAb molecules are reduced to the size of the protein diameter (approx. 10 nm).

Fast pH-mediated changes of the viscosity of protein solutions studied with a voltage-modulated quartz crystal microbalance.

An electrochemical quartz crystal microbalance is described, which achieves a time resolution down to 100 μs. Accumulation and averaging over a few hours bring the noise down to about 30 mHz. The application examples are pH-driven viscosity changes in albumin solutions.

Concentration Effects in the Interaction of Monoclonal Antibodies (mAbs) with their Immediate Environment Characterized by EPR Spectroscopy.

Monoclonal antibodies (mAbs) are often needed and applied in high concentration solutions, >100 mg/mL. Due to close intermolecular distances between mAbs at high concentrations (~10-20 nm at 200 mg/mL), intermolecular interactions between mAbs and mAbs and solvent/co-solute molecules become non-negligible. Here, EPR spectroscopy is used to study the high-concentration solutions of mAbs and their effect on co-solvated small molecules, using EPR "spin probing" assay in aqueous and buffered solutions.

Characterizing protein-protein-interaction in high-concentration monoclonal antibody systems with the quartz crystal microbalance.

Making use of a quartz crystal microbalance (QCM), concentrated solutions of therapeutic antibodies were studied with respect to their behavior under shear excitation with frequencies in the MHz range. At high protein concentration and neutral pH, viscoelastic behavior was found in the sense that the storage modulus, G', was nonzero. Fits of the frequency dependence of G'(ω) and G''(ω) (G'' being the loss modulus) using the Maxwell-model produced good agreement with the experimental data.

Liquid-liquid phase separation of a monoclonal antibody at low ionic strength: Influence of anion charge and concentration.

Liquid-liquid phase separation (LLPS) of a monoclonal antibody solution was investigated at low ionic strength in the presence of oligovalent anions, such as citrate, trimellitate, pyromellitate and mellitate. Phase separation was observed at the isoelectric point of the antibody at pH8.7 as well as in more acidic pH regions in the presence of the tested oligovalent ions.

Kupffer cell activation by hydrogen peroxide: a new mechanism of portal pressure increase.

This study aimed to investigate the effects of reactive oxygen species on the hepatic macrophages, the Kupffer cells (KC), and to identify the relevant targets of vasoconstrictors involved in the regulation of intrahepatic microcirculation and therefore portal pressure. The effects of hydrogen peroxide (H2O2), xanthine/xanthine oxidase or a thromboxane (TX) analogue (U46619; 0.1 microM) were tested in sham-operated and fibrotic livers (bile duct ligation over 4 weeks) during isolated rat liver perfusion and in vivo with or without additional KC blockade (gadolinium chloride, 10 mg kg(-1) body weight, 48 and 24 h, i.

Kupffer cell activation in normal and fibrotic livers increases portal pressure via thromboxane A(2).

Background/aims: Cirrhotic patients show an increased risk of variceal bleeding upon bacterial infections. Kupffer cells (KC) constitute the first macrophage population to become activated by bacterial beta-glucans and endotoxins derived from the gut. We therefore investigated whether and how KC activation increases portal pressure.