Search PubMed⌕ Search

Biomedical subjects

M Ried

Publications and source records attributed to M Ried.

12 recordsLinked to original sources

[Laparoscopic cholecystectomy in a patient with honeycomb lung].

Laparoscopic surgery of the gallbladder has increasingly replaced open techniques due to postoperative benefits (less pulmonary complications, less postoperative pain, earlier mobilisation). Specific intraoperative effects of pneumoperitoneum have led to some uncertainty if cardiac and/or pulmonary high-risk cases should be done laparoscopically. We describe anaesthesiological management of a 72 year old patient with a unilateral leftsided honeycomb lung (two very large cysts) to undergo laparoscopic cholecystectomy. Vital capacity was reduced to 45%, forced expiratory 1 second volume to 41%, preoperative bloodgas analysis revealed a paO2 of 64 mmHg and a paCO2 of 40 mmHg. Under spontaneous breathing the patient was fiberoptically intubated with a left sided double lumen tube (Mallinckrodt, Athlone/Irland; 37 Ch) using balanced anaesthesia. The healthy right lung was hand ventilated with 100% oxygen to avoid excessive airway pressures (peak airway pressure 27 mbar, mean airway pressure 22-24 mbar). The diseased left lung was passively insufflated with oxygen. The intraabdominal pressure was limited to 10 mmHg. Muscle relaxation was achieved with atracurium under monitoring using a nerve stimulator. The paCO2 increased from 40 to 57 mmHg during the operation, but returned to normal immediately postoperatively. All other ventilatory and hemodynamic parameters were uneventful during the 35 minute procedure. The patient was extubated at the end of the procedure and monitored on the intensive care ward for one night. A postoperative chest X-ray revealed a mediastinal shift of 2 cm to the right, healthy side as well as an atelectasis on this side. The shift was most likely due to hypoventilation of the right lung, with the ensuing atelectasis drawing the mediastinum to the right. Under physiotherapy this shift had resolved by the next morning. The patient could be discharged from hospital on day seven and fully recovered. Especially the severely cardiopulmonary compromised patient benefits from a laparoscopic procedure, due to less postoperative reduction of pulmonary function. Careful and individually adapted monitoring and anaesthetic techniques are necessary to successfully counteract the special implications of pnemoperitoneum.

Aged↗

Genetic capsid modifications allow efficient re-targeting of adeno-associated virus type 2.

The human parvovirus adeno-associated virus type 2 (AAV2) has many features that make it attractive as a vector for gene therapy. However, the broad host range of AAV2 might represent a limitation for some applications in vivo, because recombinant AAV vector (rAAV)-mediated gene transfer would not be specific for the tissue of interest. This host range is determined by the binding of the AAV2 capsid to specific cellular receptors and/or co-receptors. The tropism of AAV2 might be changed by genetically introducing a ligand peptide into the viral capsid, thereby redirecting the binding of AAV2 to other cellular receptors. We generated six AAV2 capsid mutants by inserting a 14-amino-acid targeting peptide, L14, into six different putative loops of the AAV2 capsid protein identified by comparison with the known three-dimensional structure of canine parvovirus. All mutants were efficiently packaged. Three mutants expressed L14 on the capsid surface, and one efficiently infected wild-type AAV2-resistant cell lines that expressed the integrin receptor recognized by L14. The results demonstrate that the AAV2 capsid tolerates the insertion of a nonviral ligand sequence. This might open new perspectives for the design of targeted AAV2 vectors for human somatic gene therapy.

Amino Acid Sequence↗

Lectin intravital perfusion studies in tumor-bearing mice: micrometer-resolution, wide-area mapping of microvascular labeling, distinguishing efficiently and inefficiently perfused microregions in the tumor.

Intravital lectin perfusion was combined with computer-guided scanning digital microscopy to map the perfused elements of the vasculature in tumor-bearing mice. High-precision composite images (spatial precision 1.3 micron and optical resolution 1.5 micron) were generated to permit exact positioning, reconstruction, analysis, and mapping of entire tumor cross-sections (c. 1 cm in diameter). Collation of these mosaics with nuclear magnetic resonance maps in the same tumor plane identified sites of rapid contrast medium uptake as tumor blood vessels. Digitized imaging after intravital double labeling allowed polychromatic visualization of two different types of mismatched staining. First, simultaneous application of two lectins, each bearing a different fluorochrome, revealed organ-specific differential processing in the microvascular wall. Second, sequential application of two boluses of one lectin, bearing different fluorochromes successively, distinguished between double-labeled microvessels, representing efficiently perfused vascular segments, and single-labeled microvessels, with inefficient or intermittent perfusion. Intravital lectin perfusion images of blood vessels in the vital functional state thus highlighted biologically significant differences in vessel function and served as high-resolution adjuncts to MR imaging.

Adenocarcinoma↗