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Biomedical subjects

S Schaffellner

Publications and source records attributed to S Schaffellner.

26 records · Page 2Linked to original sources
PubMed1998

Intramyocardial electrogram variability in the monitoring of graft rejection after heart transplantation.

The ventricular evoked response is a well-standardized electrophysiological signal that can be used for noninvasive, long-term cardiac transplant monitoring. Rejection-sensitive and infection-specific parameters extracted from intramyocardial electrograms correlate with clinical results. The influences of pacing rate, transition from intrinsic to paced rhythm and positional changes on the diagnostic parameters were studied. Increasing the pacing rate shortened the ventricular evoked response and directly influenced the infection specific parameter. The rejection-sensitive parameter remained stable at pacing rates between 100 and 120 beats/min. Measurements made immediately after the patient assumed a supine position and after switching to paced rhythm showed a decrease in the rejection-sensitive parameter. A change in position from supine to upright did not influence the rejection-sensitive parameter, but higher values were measured after returning to the supine position. In conclusion, noninvasive recordings of the ventricular evoked response for monitoring of cardiac allograft should be done at the same time of day, at the same pacing rate, and with the patient resting for at least 5 minutes before measurements are made.

Adolescent↗
PubMedDate not supplied

Experiences in liver transplantation for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Beside surgical resection, orthotopic liver transplantation (OLT) is not only effective but also the only potentially curable treatment in selected cases of small tumors. We report our experience in 11 male patients transplanted for HCC from August 1998 to July 2002. Selection criteria for OLT were unresectability of the hepatic tumor and severity of the underlying liver disease. The tumor diagnosis was confirmed by histology, imaging techniques, and tumor markers. All patients received an orthotopic liver allograft using a modified piggyback technique. Six of the 11 patients are alive; one died due to acute rejection and four died from recurrent disease. In all four patients with recurrent disease, vascular invasion was shown histologically, whereas only one patient without evidence of recurrence showed vascular invasion. To prevent recurrence after OLT the immunosuppressive regime was adjusted to the underlying disease by early cessation of prednisolone and reduction in the long-term exposure to immunosuppressive drugs. Patients were screened for recurrence by ultrasound and computed tomography. Recurrent HCC were treated symptomatically. OLT is an effective treatment for subgroups of patients with HCC. It might be possible to downstage the liver tumor by chemoembolization and/or radiofrequency ablation and allow the patients to wait for a suitable donor. After OLT the early withdrawal of prednisolone and the reduction of other immunosuppression is feasible. In conclusion, OLT can be a potentially curative therapy for HCC.

Adult↗
PubMedDate not supplied

Porcine islet cells microencapsulated in sodium cellulose sulfate.

One hundred fifty million people suffer from diabetes mellitus worldwide. Modern exogenous insulin therapy cannot prevent late complications. Islet cell transplantation could be a sufficient therapeutic option but the shortage of human organs limits this option. The use of xenogeneic porcine islet cells may also be a viable alternative. One way to manage hyperacute rejection is by the protection of xenogeneic cells from the immune system by microencapsulation. In this study sodium cellulose sulfate (NaCS) was evaluated as a material for encapsulation. An insulin-producing cell line (HIT-T15) was established in our laboratory. Glucose-dependent insulin production and cell growth were monitored. Cells were encapsulated with NaCS by Austrianova, Vienna. The insulin production and mitosis rate were examined. Cell growth and insulin production by HIT-T15 cells affected the glucose levels in the nutrient solution. Cell viability and glucose-dependent insulin production were not influenced by NaCS. Encapsulation with NaCS is feasible and it could be shown that the material is permeable to nutrients and metabolic side products. The encapsulated cells are able to detect the glucose concentration in the nutrient solution and to react in a proper way by producing insulin. Encapsulation with NaCS, which is more biocompatible and less immunogenic than other materials, seems to be a promising method for immunoisolation of porcine beta cells for xenotransplantation to replace the endocrine pancreas in a physiologic way.

Animals↗