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Biomedical subjects

F Schmidt

Publications and source records attributed to F Schmidt.

294 records · Page 17Linked to original sources
PubMedDate not supplied

DNA quantification and ploidy patterns in human adrenocortical neoplasms.

The determination of DNA ploidy and the study of the cell cycle in adrenocortical tumoral cells could help in the distinction between benign and malignant lesions and also in the prediction of the biological behaviour of these tumors. We analysed 32 cases of adrenal tissue (8 normal adrenals--N, 12 benign adenomas--A and 12 carcinomas--C). DNA was quantified by image analysis of Feulgen stained sections (Ahrens System) employing ACAS3 software. The DNA content was considered to be diploid in 70% of the N and in 67% of the A groups and in none of C. In this latter group nearly 90% were triploid or tetraploid while this did not occur in any of the A cases. The percentage of cases with a 5c-exceeding rate (5cER) above 5% was nil in the N and A groups and 100% in C. In what concerns the distribution in the cell cycle we found a very distinctive pattern between the groups as the percentage of cases in which the S-phase fraction exceeded 33% was nil in the normals, 8% in A and 83% in the C cases. In conclusion, there was a good correlation between the analysed parameters and the clinically defined groups of adrenal cortex tumors.

Adenoma↗
PubMedDate not supplied

Relapse of pulmonary Mycobacterium kansasii disease associated with large-cell cancer of the lung: a case report.

A 43-year-old caucasian male diabetic presented with purulent cough and a history of weight-loss, elevated temperature, night-sweat and dyspnea. Four years previously, the patient had undergone a 12-month antimycobacterial regimen because of pulmonary mycobacterium kansasii (MK) disease of the left upper lobe (LUL). Treatment had led to complete recovery with the exception of minor fibrous residuals in the involved pulmonary segments. Chest radiograph and computed tomography (CT), performed on recent admission, revealed a dense infiltration of these residual-containing segments. Microbiological evaluation of bronchial brushings, aspirates and histology of the transbronchial biopsies indicated a relapse of pulmonary MK disease. Although antimycobacterial treatment was started immediately, therapeutic effects were only minimal and remained to be limited to the initial phase of the treatment. After four weeks of treatment, the patient's general condition worsened again. Follow-up CT of the lung showed a marked increase of the infiltration in the left apicoposterior lobe and re-bronchoscopy showed a tumorous protrusion of the bronchial wall involving the apicoposterior segment ostium, a finding which was not seen in the previous bronchoscopy. Histology of the transbronchial biopsies revealed a carcinoma mainly from large-cell type.

Carcinoma, Non-Small-Cell Lung↗
PubMedDate not supplied

Topotecan-based combination chemotherapy for human malignant glioma.

BACKGROUND: Topotecan has been considered a promising agent for the adjuvant chemotherapy of human malignant glioma because of its novel mode of action, its activity against other solid tumors, and its good penetration across the blood-brain barrier. However, the clinical effects of topotecan monotherapy in malignant glioma have been disappointing. MATERIALS AND METHODS: We sought to identify suitable partners for topotecan combination chemotherapy of malignant glioma using two well-characterized human malignant glioma cell lines, T98G and LN-229. The effects of co-exposure to topotecan and other chemotherapy drugs were assessed in cytotoxic and clonogenic cell death assays. RESULTS: We found additive, less-than-additive, or occasional antagonistic effects, but never synergistic activity of topotecan with either CCNU, VM26 or vincristine, in acute cytotoxicity or in clonogenic cell death assays, with simultaneous or sequential drug exposure. VM26 or vincristine followed by topotecan yielded the most favourable results. Further, prolonged exposure of the glioma cells to topotecan and either CCNU, VM26, vincristine, cisplatin, doxorubicin or cytarabine resulted in additive but not synergistic growth inhibition. CONCLUSIONS: The present study fails to identify a specific partner for topotecan-based combination chemotherapy of malignant glioma among the chemotherapeutic drugs examined here. While this does not exclude a possible synergy of the drug combinations examined here in vivo, a focus on novel partners for topotecan or topotecan-based chemoimmunotherapy may be more promising.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Radioimmunotherapy of colorectal cancer in small volume disease and in an adjuvant setting: preclinical evaluation in comparison to equitoxic chemotherapy and initial results of an ongoing phase-I/II clinical trial.

The 5-year survival of colorectal cancer patients with distant metastases is below 30%, despite the development and use of a variety of chemotherapeutic regimens. Therefore, new therapeutic strategies are warranted. Whereas radioimmunotherapy (RIT) has shown disappointing results in bulky disease, it may be a promising therapeutic alternative in limited and small volume disease. The aim of this study was, therefore, to compare, in a preclinical study, the therapeutic efficacy of RIT in colorectal cancer to equitoxic chemotherapy, as well as to evaluate, in a pilot clinical trial, its efficacy in small volume disease. Nude mice, bearing subcutaneous or metastatic human colon cancer xenografts, were injected either with the unlabeled or 131I-labeled monoclonal antibodies (MAbs), CO17-1A (which is a murine IgG2a directed against a 41-kD membrane glycoprotein) or F023C5 (which is an anti-CEA MAb of murine IgG1 subtype), or were administered 5-fluorouracil/folinic acid (5-FU/LV) at equitoxic doses. In a pilot clinical study, 10 colorectal cancer patients with small volume metastatic disease (all lesions < or = 3 cm) have been entered so far in an ongoing mCi/m2-based dose escalation study with the 131I-labeled F023C5. In the animals, the maximum tolerated activities (MTD) of 131I-labeled CO17-1A and F023C5 were 300 microCi and 600 microCi, respectively, corresponding to blood doses of approximately 15 Gy each. Accordingly, myelotoxicity was dose-limiting. The MTD in the chemotherapy group was 0.6 mg 5-FU/1.8 mg LV, given as intravenous bolus 1 h apart for 5 subsequent days. Whereas no significant therapeutic effects were seen with both unlabeled MAbs or 5-FU/LV chemotherapy, tumor growth was retarded significantly with both radiolabeled antibodies. In the metastatic model, chemotherapy prolonged life for only a few weeks, whereas RIT led to cures in 35-55% of the animals. As was the case in the animals, myelotoxicity seems to be dose-limiting in patients as well. Encouraging anti-tumor effects were observed, lasting for up to more than 12 months. These data suggest that radioimmunotherapy may be a viable therapeutic option in colorectal cancer patients with limited disease. Myelotoxicity is the only dose-limiting organ toxicity. Although most patients were treated below the MTD, anti-tumor effects are encouraging. Further studies are ongoing.

Animals↗
PubMedDate not supplied

[Smoking damages male fertility].

It is concluded from a survey on the world literature: Smoking damages the male fertility. Smoker should therefore stop the smoking not only in respect to their own health but from sense of responsibility for the future generation too. The most important reasons for this conclusions are: Tobacco smoke contains numerous mutagenic substances. They reach the male gonads via the blood. They show their mutagenic action here openly much more stronger than on egg-cells because the spermatogenesis continues over the whole male reproductive period whereas the formation of eggs is already completed in the fetal phase. The majority of studies indicates to a damaging effect also on the number and/or the motility and morphology of spermatozoa by strong smoking during a longer time. Especially smoking husbands with infertile marriages the urgent advice therefore should be given to stop smoking. Weighty epidemiological and experimental results suggest a teratogenic action in the offspring by smoking of fathers too - independently for the smoking customs of the mother. A verification and extension of these results are very desirable.

Adult↗