Biomedical subjects

L Staib

Publications and source records attributed to L Staib.

44 records · Page 3Linked to original sources

PubMed1996

Regional chemotherapy directed by individual chemosensitivity testing in vitro: a prospective decision-aiding trial.

A prospective decision-aiding trial was performed to select drugs for regional chemotherapy of various liver tumors (n = 36) by individual drug testing. The drugs were chosen for hepatic artery infusion according to the individual chemosensitivity of tumor biopsies in the human tumor colony-forming assay (HTCA). In vitro HTCA sensitivity correlated with complete response (CR) + partial response (PR) + no change (NC) 93% of the time and with CR + PR 55% of the time. The test sensitivity was 90%, and the specificity was 67% for CR + PR + NC versus progressive disease (PD), whereas the sensitivity and specificity were 89% and 28%, respectively, for CR + PR versus NC + PD. The overall predictive accuracy of the test was 86% for CR + PR + NC versus PD and 58% for CR + PR versus NC + PD. Overall, 83% of this heterogenous patient group with various tumors achieved CR + PR + NC and a 50% clinical response (CR + PR). In vitro-sensitive patients showed a significantly lower intrahepatic progression rate (7% PD) than in vitro-resistant patients (57%; P < 0.05). These results indicate that the HTCA could identify active drugs for individualized hepatic artery infusion, and patients may profit from the use of in vitro-sensitive drugs.

Adult↗

PubMed1993

Protection against experimental cerebral metastases of murine melanoma B16 by active immunization.

Melanoma patients often develop brain metastases despite effective systemic immunotherapy against melanoma. We have attempted to establish a mouse model to develop strategies to combat this problem. Immunization of C57BL/6 (H-2b) mice with a combination of the syngeneic G3.12/BM2 melanoma (a B16 subclone) and the allogeneic Cloudman-S91 melanoma was effective in preventing the growth of 10,000 viable, s.c. injected G3.12 cells in 93% of the mice. Irradiated whole tumor cells pretreated with gamma-interferon for 2 days were most effective. A nonspecific adjuvant (DETOX) was injected routinely together with the tumor cells. Active immunization with 2 different doses of irradiated melanoma cells (1 x 10(5) or 2.5 x 10(6) cells/injection x 5 injections) protected against intracerebral challenge with 200 live G3.12 cells in 69% of the mice. This challenge caused the death of all control mice within 30 days. T-cell-mediated, tumor-specific cytotoxicity against G3.12 melanoma was demonstrated in the spleen of immunized mice. Histological observations in the brain, 80 days after tumor challenge, indicated complete eradication of the melanoma, but although CD4+ and CD8+ T-cells and macrophages were present, their number was low. Gliosis was present in both immunized and control animals. Thus, in this murine melanoma model syngeneic mice were protected from death by s.c. and intracerebrally inoculated tumor cells if pretreated with a sufficient number of irradiated syngeneic and allogeneic melanoma cells and an immunological adjuvant. Whether this regimen can treat established tumors of the brain, alone or in combination, is uncertain. Yet its success suggests that the "blood-brain barrier" impeding immunity to tumors may not be absolute.

Animals↗

PubMed1991

[Gallbladder carcinoma as an incidental finding].

Between March 1982 and December 1990, 903 patients underwent elective cholecystectomy. In 40 patients cholecystectomy was performed for gallbladder carcinoma. 15 malignomas (1.7%) were found incidentally. Preoperatively no anamnestic or diagnostic tumor signs were found in this group of patients. An en-bloc-resection of the gallbladder with resection of the bordering liver segments was performed when gallbladder carcinoma was diagnosed intraoperatively. When the diagnosis was established by postoperative histology, a relaparotomy with liver resection and lymphnode-dissection was done, except in one case (T-1a stage). Histology showed adenocarcinoma in 11 out of 15 cases. No significant difference in the course of the disease was observed in patients with gallbladder carcinoma of different types. The hospital mortality rate was 0% after curative and palliative surgical treatment of gallbladder carcinoma. Patients with T-1 and T-2 stage have survived without tumor-recurrence up to now. The median survival time after surgery for gallbladder carcinoma in T-3 stage was 17 months, and 8 months in T-4 stage. The morbidity rate after elective cholecystectomy is low and hospital mortality is 0%. According to the short survival times in advanced stages of gallbladder carcinoma, a prompt cholecystectomy in symptomatic gallbladder lithiasis or chronic cholecystitis is advocated.

Adenocarcinoma↗

PubMedDate not supplied

In vitro concentration response studies and in vitro phase II tests as the experimental basis for regional chemotherapeutic protocols.

The theoretical pharmacologic benefit of regional vs. systemic chemotherapy is defined and the concentration response behavior of cytostatic drugs and their optimal exposure times are described with human cancer cell lines (HT29, NMG64/84) and fresh human tumor cell suspensions in the human tumor colony assay (HTCA). The theoretical pharmacological advantages are 5.8 to 6 for adriamycin (ADM), 8 for cisplatinum (CDDP), 6.3 for epidoxorubicin (EPI), 22 to 58 for 5-fluorouracil (5FU), 4.6 for mitomycin C (MMC), and 6.3 for mitoxantrone (NOV). The drugs differed in their cytotoxic potency in vitro and thus also potential efficacy for regional chemotherapy; however, all but 5-fluorodeoxyuridine (5FUDR) exerted cytotoxicity dependent on exposure time and concentration. On average, elevation of the test concentrations by 1 lg doubled responses in fresh human tumor cell suspensions. From these results and clinical considerations, optimal times were defined for the regional chemotherapy strategies of hepatic artery infusion, intraperitoneal instillation, and chemoembolisation as performed at our institution.

Antineoplastic Agents↗

PubMedDate not supplied

Anti-idiotypic antibody and recombinant antigen vaccines in colorectal cancer patients.

The colorectal carcinoma (CRC)-associated GA733 antigen (also known as CO17-1A, KS1-4, KSA or EpCAM) has been the target of a phase II/III randomized trial of passive immunotherapy with monoclonal antibody CO17-1A and phase I active immunotherapy trials with polyclonal anti-idiotypic antibodies mimicking the CO17-1A or GA733 epitope on the antigen. The CO17-1A antigen was molecularly cloned and the extracellular domain expressed in baculovirus (BV) GA733-2E. Whereas, anti-idiotypic antibody mimics a single epitope on the antigen, BV GA733-2E expresses multiple potentially immunogenic epitopes. In animals, the immunogenicity of BV GA733-2E in aluminum hydroxide was superior to that of anti-idiotype in the same adjuvant. Here, we compared the immunogenicity of anti-idiotypic antibody and GA733-2E antigen in CRC patients. These studies indicate that the antigen is superior to the anti-idiotype antibody in inducing humoral and cellular immunity in CRC patients.

Antibodies, Anti-Idiotypic↗

PubMedDate not supplied

Toxicity and effects of adjuvant therapy in colon cancer: results of the German prospective, controlled randomized multicenter trial FOGT-1.

In this adjuvant three-arm multicenter trial, we studied whether modulating the standard 5-fluorouracil (5-FU) treatment with either folinic acid (FA) or interferon-alpha-2a (IFN-alpha) was superior to the recommended standard of adjuvant treatment in R0 resected colon cancer, 5-FU plus levamisole (LEV) for 12 months, in terms of toxicity and outcome. From July 1992 to October 1999, a total of 813 patients with resected colon cancer in stage II (T4N0M0; n = 63) or stage III (TxN1-3M0; n = 750) were randomized into three treatment groups and stratified according to N stage and participating centers (64 hospitals). The patients received a postoperative loading dose of 5-FU (450 mg/m2 on days 1 to 5 [arms A and C]) or 5-FU (450 mg/m2) plus FA (Rescuvolin, Medac, Hamburg, Germany, 200 mg/m2 on days 1 to 5 [arm B]). After completion of the first chemotherapy cycle, LEV was administered orally at a dosage of 150 mg per day on days 1 to 3, once every 2 weeks. After a 4-week chemotherapy-free interval, the treatment was continued weekly for 52 weeks. Treatment in one arm A ("standard") (n = 279) consisted of 5-FU intravenously (450 mg/m2 on day 1, once a week) plus LEV. 5-FU plus LEV was modulated in arm B (n = 283) with FA (200 mg/m2 on day 1, once a week) and in arm C (n = 251) with IFN-alpha at 6 million units three times a week repeated weekly. Treatment dosages were adjusted if toxic events above WHO grade 2 occurred. Patients were closely followed to determine recurrence and survival; the latter was calculated according to Kaplan-Meier analysis. Toxic events above WHO grade 2, mainly leukopenia, diarrhea, and nausea, occurred in 113 (14%) of 649 patients who had completed treatment in arms A (8.4%), B (13.5%), and C (31.7%). Discontinuance rates were as follows: 28% for all patients, 29% in arm A, 21% in arm B, and 34% in arm C. Overall relapse rates were 27% for all patients, 30% in arm A, 24% in arm B, and 28% in arm C. Relapses were local (8%), distant (78%), or combined (12%). Four-year overall survival rates in arms A, B, and C were 66.1%, 77.5%, and 66.2%, respectively. The 4-year survival rate in arm B was significantly higher compared to arm A (P <0.02, log-rank test) with arm A being equal to arm C. Adjuvant therapy with 5-FU plus FA plus LEV for 12 months is superior to the recommended standard (5-FU + LEV for 12 months). IFN-alpha modulation of 5-FU (plus LEV) adds to the toxicity with no therapeutic benefit.

Adjuvants, Immunologic↗

PubMedDate not supplied

PathMaster: content-based cell image retrieval using automated feature extraction.

OBJECTIVE: Currently, when cytopathology images are archived, they are typically stored with a limited text-based description of their content. Such a description inherently fails to quantify the properties of an image and refers to an extremely small fraction of its information content. This paper describes a method for automatically indexing images of individual cells and their associated diagnoses by computationally derived cell descriptors. This methodology may serve to better index data contained in digital image databases, thereby enabling cytologists and pathologists to cross-reference cells of unknown etiology or nature. DESIGN: The indexing method, implemented in a program called PathMaster, uses a series of computer-based feature extraction routines. Descriptors of individual cell characteristics generated by these routines are employed as indexes of cell morphology, texture, color, and spatial orientation. MEASUREMENTS: The indexing fidelity of the program was tested after populating its database with images of 152 lymphocytes/lymphoma cells captured from lymph node touch preparations stained with hematoxylin and eosin. Images of "unknown" lymphoid cells, previously unprocessed, were then submitted for feature extraction and diagnostic cross-referencing analysis. RESULTS: PathMaster listed the correct diagnosis as its first differential in 94 percent of recognition trials. In the remaining 6 percent of trials, PathMaster listed the correct diagnosis within the first three "differentials." CONCLUSION: PathMaster is a pilot cell image indexing program/search engine that creates an indexed reference of images. Use of such a reference may provide assistance in the diagnostic/prognostic process by furnishing a prioritized list of possible identifications for a cell of uncertain etiology.

Abstracting and Indexing↗

PubMedDate not supplied

Uptake and displacement of [3H]-propranolol and [3H]-chlorpromazine in isolated, recirculating perfused guinea-pig lungs.

The pulmonary uptake of tritium labelled propranolol and chlorpromazine and their displacement by amphiphilic drugs has been studied in isolated guinea-pig lungs. Lungs were perfused by recirculation with 60 ml tyrode solution (carbogen gassed, 37 degrees C, 6% hydroxy-ethyl-starch) at a flow rate of 10 ml/min. In uptake experiments, a steady state was reached within 20 min with 95% of 10(-9) M propranolol and 90% of 10(-9) M chlorpromazine removed from the perfusate. Using 10(-4) M propranolol, a saturation process became evident, whereas no concentration dependency was observed for chlorpromazine uptake. Kinetic analysis revealed similar uptake rates, but different capacities for both compounds. In displacement experiments, 10(-9) M propranolol was displaced by 10(-4) M amphiphilic drugs in the order: chlorpromazine greater than propranolol greater than alprenolol greater than tetracaine. No displacement occurred by practolol, indomethacin or phenylbutazone. The results indicate that the lungs have a large binding capacity for amphiphilic drugs. These compounds can interfere with each other, according to their lipophilicity, their steric configuration and charges.

Animals↗