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D L Glaubiger

Publications and source records attributed to D L Glaubiger.

27 records · Page 2Linked to original sources
PubMed1980

Determination of prognostic factors and their influence on therapeutic results in patients with Ewing's sarcoma.

We have analyzed the results of treatment of 117 patients with Ewing's sarcoma admitted to the National Cancer Institute since 1964. All patients received local irradiation to the primary site and a series of progressively more intensive systemic chemotherapy regimens using drugs known to be active as single agents in this disease. Four protocols were employed with varying numbers of patients in each treatment group. Initially, there appeared to be a difference among treatment groups with regard to disease-free survival (overall P = .06), with the later regimens having more favorable outcomes. We then undertook a statistical analysis of the influence of five pretreatment variables--age, sex, site of primary disease, serum lactic acid dehydrogenase (LDH), and metastatic status--on disease-free survival. Of these five factors, important indicators of favorable prognosis for the entire group (and for each of the treatment subgroups) were a distal site of primary disease, normal serum lactic acid dehydrogenase (LDH) level at presentation, and the absence of metastatic disease at the time of presentation. When we examined treatment results with respect to these prognostic factors, we found that the subgroups treated with the more agressive regimens contained higher proportions of patients with favorable prognostic factors. After adjustment for differences in composition of treatment groups with respect to prognostic factors, the apparent difference in disease-free survival vanished (P = .62). These results indicate that in the case of Ewing's sarcoma, prognostic factors must be carefully considered in the design of treatment protocols and the subsequent analysis of end results.

Age Factors↗
PubMed1980

Electrolytic degradation of DNA fluorochromes during flow cytometric measurement of electronic cell volume.

Changes in flow cytometric measurement of DNA content can result from electrolytic chemical degradation of mithramycin, ethidium bromide, and propidium iodide during simultaneous measurement of electronic cell volume. Bench electrolysis also degrades these fluorochromes without changing the quantum yields, even when they are complexed to DNA. In the flow cytometer, electrolytic production of chlorine at the anode is the probable cause of this degradation, since exposure of these fluorochromes to chlorine gas produces the same effect. It is therefore advisable to measure the DNA content distribution alone before simultaneously measuring the DNA content and the electronic cell volume. If unavoidable effects on the DNA distribution are present, narrow forward-angle light scatter should be used as the cell size indicator during dual parameter measurements. Modifying instrument design by reversing electrode polarity might eliminate this problem.

Cytological Techniques↗
PubMed1980

Active transport of methotrexate from cerebrospinal fluid in humans.

The cerebrospinal fluid (CSF) efflux kinetics of methotrexate (MTX) were studied in three patients with indwelling Ommaya reservoirs. A small dose of MTX was injected intraventricularly several hr after the start of a high-dose continuous i.v. infusion of MTX. In all patients, the CSF antifolate concentration returned to the preinjection level before the end of the i.v. infusion. This result indicated that the efflux of MTX from CSF in humans is independent of plasma drug concentrations. Efflux kinetics were further characterized in one patient. Serially obtained CSF samples after intraventricular injections demonstrated a biphasic disappearance curve with alpha- and beta-phase half-disappearance times of 1.7 and 6.6 hr, respectively. Prolongation of the beta-phase half-time was associated with oral acetazolamide medication and with increased intracranial pressure, indicating that inhibition of CSF production slows MTX clearance. CSF MTX concentration, however, declined more rapidly than that of simultaneously administered diethylenetriaminepentaacetic acid, an extracellular marker substance excreted by bulk flow, indicating that bulk flow excretion alone is insufficient to account for MTX efflux from human CSF. Evidence that there is an active transport component was provided by probenecid pretreatment which also prolonged the CSF MTX half-life. These findings suggest that both passive and active mechanisms govern MTX efflux from the CSF in humans and that they can be inhibited by acetazolamide and probenecid, respectively.

Acetazolamide↗
PubMed1979

Azaserine, DON, and azotomycin: three diazo analogs of L-glutamine with clinical antitumor activity.

A review of the clinical data on azaserine, DON, and azotomycin reveals that these agents have limited but definite antitumor activity. All three drugs are analogs of L-glutamine and contain a diazo group. They have been studied as single agents in a wide variety of human malignancies and have also been included in trials using combination chemotherapy. Most of these studies were performed early in the history of clinical trials and, therefore, the method of reporting results and the evaluation criteria were quite different from those in use today. A renewed interest in these agents has been triggered by the remarkable activity of DON and azotomycin against human tumor lines implanted into nude mice. On the basis of this activity and the clinical data we have compiled, we feel that new clinical trials with these agents are warranted.

Animals↗
PubMed1978

Protein-associated DNA breaks in cells treated with adriamycin or ellipticine.

The effect of intercalating agents on mammalian DNA in vivo was examined by the technique of alkaline elution. Adriamycin and ellipticine were found to produce large numbers of single-strand breaks. These breaks appeared to be intimately associated with protein to the extent that enzymatic deproteinization of the DNA was necessary to reveal the breaks. The frequency of breaks and cross-links increased with concentration and time of exposure to the drugs. These data suggest that DNA single-strand scission may be a feature common to intercalators. The association with a cellular protein is previously undescribed and suggests possible mechanisms for the strand scission.

Alkaloids↗
PubMed1978

Probenecid inhibition of methotrexate-cerebrospinal fluid pharmacokinetics in dogs.

Cerebrospinal fluid (CSF) and plasma concentrations of methotrexate (MTX) were followed in dogs for 72 hours after intracisternal injection of MTX with and without probenecid pretreatment. CSF levels declined as a biexponential function of time. Probenecid pretreatment of the animals prolonged the second phase half-disappearance time of MTX from 5.20 +/- 0.89 to 7.086 +/- 0.23 hours (mean +/- SD). The peak mean plasma concentration of MTX was lower in the presence of probenecid. Also, the rate of decline of plasma MTX concentrations was slower after treatment with probenecid, with mean half-disappearance times of 7.60 +/- 0.77 and 11.32 +/- 1.08 hours. These CSF and plasma data support the proposal that probenecid inhibits the transfer of MTX from CSF to blood.

Animals↗
PubMedDate not supplied

Subsequent cancer in patients with Ewing's sarcoma.

Among 31 long-term survivors of Ewing's sarcoma, two patients developed second primary cancers, compared to an expected number of 0.03 (relative risk = 72; 95% confidence limit = 8-259). One patient had renal medullary neuroblastoma, which is not known to be related to Ewing's tumor or its therapy. The second patient had a bone fibrosarcoma, arising at the primary tumor site, which was thought to be radiation-induced. The risk of radiation-induced bone sarcomas was lower, although not significantly so, than in a recently reported series of Ewing's tumor. These two reports suggest that patients with Ewing's sarcoma have a tendency to develop radiogenic sarcomas following primary megavoltage radiation therapy. The lowest radiation dose consistent with local tumor eradication should be employed to minimize the risk of subsequent radiogenic cancer.

Adolescent↗