Biomedical subjects

S C Schmidt

Publications and source records attributed to S C Schmidt.

23 records · Page 2Linked to original sources

PubMed1992

Immunotherapy of advanced ovarian carcinomas by activation of the idiotypic network.

The positive effect of an immunotherapy using tumor-associated antigens or tumor cells of ovarian carcinomas has not yet been proven. Although many unique tumor-associated antigens have been described and a tumor rejection could be seen in occasional cases, the failure of the immune system to destroy tumor cells is not clearly understood. An alternative approach is to initiate the idiotypic network utilizing antibodies (Ab1 or 2) against a tumor-associated antigen, which induces the production of anti-idiotypic-antibodies (Ab2 beta), mimicking the "internal image" of the tumor-associated antigen. These antibodies are able to induce a specific antitumor immunity in two ways: (1) the Ab2 can present the critical epitope in a different way and so modulates the immune system, or (2) it can induce the production of an Ab3, which by itself binds to the tumor antigen. Our first results on 22 patients with advanced ovarian carcinomas show that the induction of an anti-idiotypic antibody (Ab2 beta) against OC 125 mimicking the TAA Class III CA 125 leads to a prolongation of the survival rate also for extended stages. We see a beneficial role of the induction of the idiotypic network against a tumor-associated antigen showing delayed clinical courses of the disease after vaccination of the patients with antibody fragments of the OC 125.

Antibodies, Anti-Idiotypic↗

PubMed1991

Continuous versus conventional tissue expansion: experimental verification of a new technique.

Historically, tissue expansion is a prolonged process, typically requiring at least 6 weeks to complete. Recently, interest has increased in shortening this time period. In the current study, a continuous infusion device maintaining constant expander pressure less than capillary filling pressure was used in a canine model in seven dogs to minimize the time period needed to achieve significant expansion. There were no complications, except one device malfunction, corrected by changes in design. The process was shown to be a safe and effective means of producing amounts of expansion similar to traditional methods in approximately 72 hours, with expansion of 28 percent (n = 6) for continuous tissue expansion (CTE) versus 34 percent (n = 6) for a 2-week rapid expansion protocol. This expansion was derived from either stretch of preexisting tissue (46 percent for CTE, 35 percent for 2-week expansion) or recruitment of adjacent tissue. The clinical application of continuous tissue expansion could permit the advantages of tissue expansion to be obtained in many more situations than are currently available to traditional tissue expansion techniques.

Animals↗

PubMed1990

Gas exchange in extracorporeal circuits for neonates: comparison of three different canulation systems during animal experiments.

During twenty animal experiments the effectiveness of the gas exchange during extracorporeal membrane oxygenation (ECMO) was evaluated. Arteriovenous, venovenous and venoarterial perfusion systems were compared. While PO2 saturation values were sufficient in all three groups the PO2 values were significant higher during arteriovenous perfusion (84.22 +/- 3.5 mmHg) compared to venovenous 71.99 +/- 7.3 mmHg) and venoarterial (65.11 +/- 4.5 mmHg) perfusion (p less than 0.001). PCO2 values correlated with the flow in the extracorporeal circuit in all three groups. The absolute values of PCO2 were significantly lowest during venoarterial perfusion (39.68 +/- 3.1 mmHg) compared to the venovenous (42.69 +/- 3.3 mmHg) and the arteriovenous mode (49.96 +/- 4.1 mmHg). These results indicate that perfusion circuits other than the original venoarterial ECMO could provide sufficient gas transfer for respiratory insufficient neonates while avoiding points of criticism of such systems.

Animals↗

PubMed1987

The continuous measurement of transcutaneous carbon dioxide tension (TcPCO2), an atraumatic tool to verify fetal acidosis?

TcPCO2 monitoring of the fetus during labour was evaluated as an atraumatic tool to identify or exclude fetal acidosis in 224 high-risk deliveries. A heated electrochemical sensor with a measuring temperature of 39 degrees C (n = 105) or 44 degrees C (n = 119) was applied to the fetal scalp. There was a statistically significant correlation between the TcPCO2 and the fetal blood pH at both temperatures. The sensitivity of the method was 0.90 and 0.61 at the two measuring temperatures of 44 degrees or 39 degrees respectively and the specificity was 0.93 and 0.79 respectively. The negative predictive value was high (0.99 and 0.95 respectively), but the respective positive predictive values were only 0.53 and 0.24. We conclude that the continuous measurement of the TcPCO2 is a valid additional tool to exclude fetal acidosis in most cases where fetal distress is indicated by the heart rate pattern but a TcPCO2 value above the cut-off point should be verified by an additional method to avoid unnecessary operative deliveries.

Acidosis, Respiratory↗

PubMedDate not supplied

Low malignant epithelioid peritoneal mesothelioma: successful treatment with surgical therapy alone.

A 31-year-old man presented with malignant peritoneal mesothelioma. His past medical history was uneventful, specifically there was no personal or environmental asbestos exposure. The patient was treated by complete tumor resection including peritonectomy. Because of the histologic diagnosis of a low malignant, unusual highly differentiated epithelioid tumor with very low proliferative activity a postoperative chemotherapy was not administered. After a follow-up of 20 months, the patient is in excellent clinical condition and there is no evidence of disease by computed tomography. The present paper reports a case of this rare variant of malignant peritoneal mesothelioma.

Adult↗