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Biomedical subjects

H Rainer

Publications and source records attributed to H Rainer.

At least 19 recordsLinked to original sources
PubMed1991

[Pamidronate in the treatment of tumor-associated hypercalcemia].

After a 48-hour rehydration period 28 of 31 patients with cancer-associated hypercalcemia (serum calcium greater than or equal to 2.8 mmol/l) were treated intravenously with the bisphosphonate pamidronate. In three patients fluid repletion with 0.9% saline solution had already normalized serum calcium levels. Pamidronate was given in a single infusion on day 0, the dose of pamidronate adapted to the severity of hypercalcemia. If the serum calcium concentration was greater than or equal to 2.8 mmol/l on day 3, application of pamidronate was repeated. In all patients normocalcemia was restored; mean serum calcium decreased from 3.2 +/- 0.35 on day 0 to 2.15 +/- 0.32 on day 12. Hypercalcemia recurred in 11 patients, seven of these underwent pamidronate treatment according to the same therapeutical regimen. Normal calcium levels were attained in five cases. Side effects were of minor gravity: brief hyperthermia occurred in four patients and transient, asymptomatic hypocalcemia was noticed in nine cases.

Adult↗
PubMed1991

Instability of the anticancer agent etoposide under in vitro culture conditions.

Degradation of etoposide is rapid under in vitro culture conditions. At pH 7.4 and 37 degrees C, the isomerisation of trans-etoposide to the inactive compound cis-etoposide has a half-life of 2 days in Dulbecco's modified Eagle's medium and results in the loss of 90% of the active drug within 1 week. As a consequence, prolonged incubations with etoposide in in vitro assays may lead to erroneous interpretations ignoring the real in vitro situation. The degradation is not influenced by organic compounds such as bovine serum albumin or amino acids but depends strongly on the pH value and, to a lesser degree, on the ionic strength of the medium. Therefore, we propose a mathematical correction based on the pH value so as to obtain the real exposure of cells to trans-etoposide during in vitro assays.

Cells, Cultured↗
PubMed1991

Complete remission of metastasised clear cell sarcoma of tendons and aponeuroses.

Clear cell sarcoma of tendons and aponeuroses is a rare disorder which originates from migrated neural crest cells. It tends to local recurrences and dissemination and the prognosis has to be considered as poor. Based on a small series of patients, a wide surgical excision of the primary tumour or amputation are the therapies of choice. Radiotherapy might be of some value as an adjuvant treatment but radiotherapy and chemotherapy are of little value in the treatment of the advanced disease. Because of the lack of treatment alternatives we treated a 40-year-old female patient with disseminated clear cell sarcoma with interferon-alpha 2b (IFN-alpha 2b) perilesionally after several courses of systemic chemotherapy and radiotherapy had failed. After 4 months of therapy the patient came into a complete pathological remission which lasted for 17 months. A relapse of round cell sarcoma on both tumour sites was then noted. This outcome shows that IFN-alpha 2b was able to induce a complete remission in clear cell sarcoma and might have altered the natural course of the disease. IFN-alpha should be studied as adjuvant therapy after surgery of primary clear cell sarcoma and as a first-line palliative treatment in disseminated disease.

Adult↗
PubMed1991

[Purine and pyrimidine metabolites for the estimation of rumen metabolism: HPLC analysis in milk and blood plasma].

In milk and blood plasma samples of 6 German Simmental and 12 German Black and White heifers it was investigated, whether purine and pyrimidine compounds are suitable indicators of the microbial protein synthesis in the rumen. Therefore the secreted quantities in milk and the concentration in blood plasma are correlated with energy intake. The results indicated significant correlation coefficients for both the secretion quantity of allantoin in milk (r = 0.942) and the concentration of allantoin in blood plasma (r = 0.694). Other investigated compounds appeared more suitable for evaluating the mammary gland metabolism (uridine-lactose synthesis, pseudouridine-protein synthesis). In an experiment with 7 male castrated pigmy goats subjected to a four-day fasting period the decrease of plasma allantoin, which was already apparent after 12 hours of fasting, was closely correlated with the increase of plasma free fatty acids.

Allantoin↗
PubMed1988

Escalating dose regimen of intraperitoneal mitoxantrone: phase I study--clinical and pharmacokinetic evaluation.

Mitoxantrone, a recent anthracenedione derivative, is a potentially useful drug for direct intraperitoneal (i.p.) application because of its high tissue binding and therapeutic index. We have carried out studies to establish maximum tolerated doses as well as pharmacokinetic studies with i.p. mitoxantrone in 21 patients (5 male, 16 female) with gastrointestinal (9), ovarian (6), unknown (2) and other (4) primary cancers and peritoneal carcinomatosis. Increasing doses (10-40 mg/m2) were given i.p. every 4 weeks. Five partial remissions (2-8+ months) and 7 stable disease courses (2-6+ months) were achieved. A reduction or disappearance of ascites was seen in an additional 3 patients. Severe toxicity (leucopenia) was observed in 4 patients only after 35 and 40 mg/m2 i.p. Pharmacokinetic analysis using high performance liquid chromatography yielded the following data: The mean ratio of area under curve peritoneal fluid to plasma was 1109. The peritoneal clearance rate was 680 ml/min and the mean disappearance half life was 13.1 h. Mean urinary excretion within 24 h was 0.42% of the i.p. dose. These data indicate that mitoxantrone is sequestered in the intraperitoneal tissue compartment and only slowly released. Based on the outcome of this phase I study we recommend phase II studies at a dose of 30 mg/m2 i.p., repeated every 3-4 weeks.

Adult↗
PubMed1987

Poly(I).poly(C), a potential drug carrier for the antitumor agent mitoxantrone: in vitro drug binding study.

Coupling of mitoxantrone, a new antitumor agent, to a macromolecular carrier system may improve the drug's selectivity of action and pharmacokinetic properties. We have studied in vitro binding of mitoxantrone to poly(I).poly(C), a macromolecular, double-stranded homoribopolymer, by equilibrium dialysis and high-performance liquid chromatography (HPLC). Results showed high binding affinity for mitoxantrone to poly(I).poly(C) (Kd = 1.05 X 10(-6) M), the calculated number of mitoxantrone-binding sites is 60 per molecule poly(I).poly(C). In view of the good tolerance in clinical studies, poly(I).poly(C) may thus be a useful drug carrier for mitoxantrone. A mitoxantrone:poly(I).poly(C) ratio of 1:30 (w/w) is recommended for therapeutic studies.

Binding Sites↗
PubMed1987

Phase-I study of intraperitoneal mitoxantrone--clinical and pharmacokinetic evaluation.

Mitoxantrone, a recent anthracenedione derivative is a potentially useful drug for direct intraperitoneal (i.p.) application because of its high tissue-binding and therapeutic index. We have carried out studies to establish maximum tolerated doses as well as pharmacokinetic studies with i.p. mitoxantrone in 21 patients (5 male, 16 female) with gastrointestinal (9), ovarian (6), unknown (2) and other (4) primary cancers and peritoneal carcinomatosis. Increasing doses (10-40 mg/m2) were given i.p. every 4 weeks. Five partial remissions (2-8+ months) and 7 stable disease courses (2-6+ months) were achieved. A reduction or disappearance of ascites was seen in an additional 3 patients. Severe toxicity (leukopenia) was observed in 4 patients only after 35 mg/m2 and 40 mg/m2 i.p. Pharmacokinetic analysis using high-performance liquid chromatography yielded the following data: The mean ratio of area under curve peritoneal fluid to serum was 1,108. The peritoneal clearance ranged from 2 ml/min to 9,617 ml/min and the disappearance half-life from 0.6-28.9 h. Mean urinary excretion within 24 h was 0.42% of the i.p. dose. These data indicate that mitoxantrone is sequestered in the intraperitoneal tissue compartment and only slowly released. Based on the outcome of this phase-I study we recommend phase-II studies at a dose of 30 mg/m2 i.p., repeated every 3-4 weeks.

Drug Evaluation↗
PubMed1987

Coupling of mitoxantrone to poly(I).poly(C) reduces absorption after intraperitoneal administration.

Coupling of mitoxantrone (M), an intercalating cytostatic, to macromolecular polynucleotides may reduce side effects after direct intraperitoneal chemotherapy by interfering with systemic absorption of M. We have administered free M (30 mg/m2) or M mixed with poly(I).poly(C) (90 mg/m2) intraperitoneally to 5 patients with peritoneal carcinosis (cross-over study): peak plasma levels (HPLC assay) were 62 +/- 12 versus 28 +/- 4 ng/ml (p less than 0.0025), AUC0-24h were 583 +/- 126 versus 481 +/- 57 ng X h/ml (p less than 0.025). Coupling of M to poly(I).poly(C) seems to reduce M absorption after intraperitoneal administration.

Absorption↗
PubMed1986

[Adjuvant chemotherapy in patients with radical resection of stomach cancer: 5-year results of a prospective randomized study].

102 patients with operable gastric carcinoma were randomly allocated to untreated control, polychemotherapy, chemoimmunotherapy. At a median follow-up of 5 years, chemotherapy did not improve the overall survival rate. However, in certain subgroups, patients with lymphnode metastases and intestinal tumor type showed a significant survival benefit when treated with adjuvant chemotherapy. Furthermore, we found the site of first recurrence very closely related to the type of tumor histology. Regardless of the positive effect of chemotherapy in retrospective subset-analysis, we do not generally recommend the use of polychemotherapy in operable gastric carcinoma.

Aged↗
PubMed1985

Prospective randomized clinical trial: protoadjuvant chemotherapy vs. protoadjuvant radiotherapy in breast cancer stages T3/4, N+/-, M0.

Patients selected for neo-adjuvant therapy in this trial suffered from breast cancer stages T3/4, N0/+, M0. Selected patients were stratified and assigned to either pre- and post-operative chemotherapy (tamoxifen, fluorouracil, vincristine, methotrexate, cyclophosphamide, mitoxantrone) or radiotherapy by randomization. This interim report deals with side-effects and response rates of pre-operative therapy only. For this subgroup from 41 centres, 67 patients have so far been accepted for protocol treatment. 36 received peri-operative chemotherapy and 31 perioperative radiotherapy. We have completed reports of 66 pre-operative chemotherapeutic cycles pointing out only low side-effects in spite of a combination consisting of 5 different cytotoxic agents plus hormonal therapy. It is remarkable that 79% had no hair loss and 74% no gastrointestinal side-effects; in the chemotherapy-group 24 patients so far have been operated. Response rates were as follows: 1 (4%) complete remission, 9 (38%) partial remission, 7 (29%) minor response, 2 (8%) no response and 2 (8%) progression. In 2 patients response could not be determined. In the perioperative radiotherapy-group 10 patients have been operated with similar response rates. It is interesting to note, that both therapies influenced receptor values in different ways: Chemotherapy decreased receptor values, whereas radiotherapy insignificantly increased them. The purpose of this study is to establish a rational base for post-operative cytotoxic treatment of patients as only patients who objectively respond to preoperative treatment are likely to benefit from postoperative drug administration. The study is open for enrollment until a total of 200 patients is reached.

Adult↗