PubMed Health⌕ Search

Biomedical subjects

J L Grem

Publications and source records attributed to J L Grem.

At least 109 records · Page 6Linked to original sources
PubMed1988

The role of methotrexate in osteosarcoma.

High-dose methotrexate (MTX) is one of the agents currently used in intensive adjuvant chemotherapy regimens for nonmetastatic osteosarcoma. To elucidate the role of high-dose MTX in this disease, we present the history of trials conducted with MTX from the first single-agent studies through progressively complex combination regimens. With this background, some of the basic issues concerning MTX therapy in osteosarcoma are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

A phase II evaluation of combination chemotherapy plus aminoglutethimide in women with metastatic or recurrent breast carcinoma. An Eastern Cooperative Oncology Group Pilot Study.

The Eastern Cooperative Oncology Group (ECOG) conducted a pilot study of combination chemotherapy with cyclophosphamide, doxorubicin, and 5-fluorouracil plus aminoglutethimide (250 mg three times daily with hydrocortisone supplementation of 40 mg daily) as primary therapy for estrogen receptor-positive or unknown advanced breast carcinoma to assess whether these agents can be safely combined and to provide a preliminary estimate of response rate. A total of 47 patients, 45 with metastatic breast cancer and two with stage IV disease who were rendered clinically disease free following surgical resection of chest wall recurrence, were treated. Leukopenia and mucositis were the most frequent toxicities requiring dose reduction, but only five patients (10.6%; 95% confidence interval, 1.8-18.4%) experienced life-threatening leukopenia (less than 1000/mm3) at some point during their therapy. Neurologic side effects attributed to aminoglutethimide, predominantly lethargy, were reported in less than one-third of patients, and rarely required dose reduction. One elderly patient developed clinical hypothyroidism during the first 3 months on therapy and experienced a cardiac arrest at home while receiving supplemental thyroid hormones. The overall complete plus partial response rate in 45 patients was 55.5% (95% confidence interval, 41-70%). Among 16 patients with measurable disease, the complete plus partial response rate was 75% (95% confidence interval, 54-96%). The complete plus partial response rate in 29 patients with nonmeasurable but evaluable disease was 45% (95% confidence interval, 27-63%) and an additional 14% had improvement in bone pain. Eight patients electively discontinued chemotherapy after 7-24 months of therapy, but continued aminoglutethimide. The median time to disease progression is 462 days (15.4 months); 25% of patients died by 552 days (18.4 months), and the median duration of survival is predicted to be 889 days (29.6 months). We conclude that aminoglutethimide can be combined with this doxorubicin-based regimen with acceptable toxicity and an overall response rate which is similar to that observed on prior ECOG trials with cyclophosphamide, doxorubicin, and 5-fluorouracil.

Adult↗
PubMed1988

Teniposide in the treatment of leukemia: a case study of conflicting priorities in the development of drugs for fatal diseases.

Teniposide, a semisynthetic epipodophyllotoxin, was found to be highly active against murine leukemias, and the combination of teniposide with cytosine arabinoside (ara-C) was curative in murine leukemia models. The antitumor activity in preclinical models prompted introduction of teniposide into the clinic in 1971. Although teniposide as a single agent rarely produced a complete remission in heavily pretreated leukemia patients, teniposide plus ara-C produced complete remissions in some patients with refractory and relapsed acute lymphoblastic leukemia (ALL). Innovative front-line and salvage regimens using teniposide have been developed that incorporate a multi-drug strategy with early intensification, rotation of drug combinations in maintenance, and regional therapy in an effort to improve the cure rate in leukemia. However, as the complexity of these regimens increases, the contribution of an individual component such as teniposide becomes less clear. Although some of these regimens for newly diagnosed and relapsed ALL are now thought to represent the best available therapy, teniposide remains an investigational agent. In this review, we outline and discuss the conflicts arising from the need to answer drug-specific issues, and, at the same time, facilitate the implementation of innovative, curative regimens.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Antimetabolites.

The mechanisms of action of MTX and 5-FU have been further elucidated. Such studies will be important for the design of drug combinations and for the development of novel antifolate and fluoropyrimidine analogs. A greater understanding of MTX and ara-C transport and drug levels required to optimize transport may also aid in these endeavors. Pharmacokinetic parameters have been found to be predictors of relapse in children with acute leukemia, particularly with respect to MTX, 6-MP and ara-C. The intracellular terminal half-life of ara-C was correlated with remission duration in AML. Assay systems aimed at uncovering response predictors through biochemical analysis of patient tumor samples are being developed, including an interesting use of NMR spectroscopy to study the pharmacokinetics of fluorine-19-labeled 5-FU in vivo. Such an approach may yield valuable information on 5-FU anabolism in tumors in situ. A high frequency of resistance to MTX apparently may be generated within a single cell cycle by transient exposures to DNA synthesis inhibitors. The resistance may be based on either target enzyme amplification or altered membrane transport. These important studies provided bases for the rapid emergence of clinical resistance. Further, the multidrug-resistant phenotype appears to be a much broader based phenomenon as MTX resistance was found to be a frequent event in cells selected for multidrug resistance. A variety of novel approaches have been proposed to overcome antimetabolite resistance and to improve the selectivity of these agents, including the use of guanosine nucleotides, leucovorin and allopurines as biochemical modulators of 5-FU. Efficient techniques for the transfection of resistant DHFR into tissues using retroviruses have been reported. These studies serve as starting point for the ultimate development of more effective strategies for the treatment of human malignancies.

Antimetabolites, Antineoplastic↗
PubMed1987

Arabinosyl-5-azacytosine: a novel nucleoside entering clinical trials.

Arabinosyl-5-azacytosine is a new compound which has been selected by the Division of Cancer Treatment, National Cancer Institute for clinical development as an antineoplastic agent based on its high degree of activity against a broad range of tumor types in preclinical studies. Therapeutic activity has been observed against murine and human leukemias, transplantable murine solid tumors, and human tumor xenografts. Arabinosyl-5-azacytosine exhibited a broader spectrum of activity against human solid tumors than cytosine arabinoside. Arabinosyl-5-azacytosine is phosphorylated to the nucleotide level by deoxycytidine kinase. Upon further anabolism to the triphosphate level, it can be incorporated into DNA. The mechanism of cytotoxicity is thought to be related to inhibition of DNA synthesis. Leukemic and solid tumor cell lines that are resistant to cytosine arabinoside due to deletion of deoxycytidine kinase activity are cross-resistant to arabinosyl-5-azacytosine. Unlike cytosine arabinoside, arabinosyl-5-azacytosine does not readily undergo deamination. Schedule dependence has been demonstrated in mice bearing L1210 leukemia, with superior activity seen with multiple doses administered on each treatment day compared to administration of larger but less frequently administered doses. From preliminary data in solid tumor models, however, antitumor activity did not appear to be superior with continuous infusion compared to that observed on a bolus schedule. Preclinical toxicology studies indicated that the bone marrow and gastrointestinal tract were the main target organs. A single large dose of arabinosyl-5-azacytosine could be tolerated by both mice and dogs. When administered as a continuous infusion, the toxicity was related to both the dose and duration of exposure, suggesting that toxicity resulted from a critical time above a threshold concentration as opposed to the total area under the concentration-time curve. Phase I clinical trials have been initiated to determine the maximum tolerated dose on a low dose continuous infusion schedule for 72 hours and also on a high dose short infusion daily times five schedule.

Antiviral Agents↗
PubMed1987

Platinum analogue combination chemotherapy: cisplatin and carboplatin--a phase I trial with pharmacokinetic assessment of the effect of cisplatin administration on carboplatin excretion.

Cisplatin (NSC 119875) and carboplatin (NSC 241240) are platinum (II) analogues with very different spectra of toxicity. Cisplatin dose is limited by nausea and vomiting, renal dysfunction, and dose-related peripheral neuropathy, whereas carboplatin is myelosuppressive. There are also clinical and laboratory data that suggest that these drugs may not be completely cross-resistant. Therefore, the following phase I trial of combination therapy with cisplatin and carboplatin was undertaken. Since carboplatin toxicity is enhanced in the presence of renal impairment, carboplatin excretion was also evaluated in selected patients at the maximum tolerated dose. Thirty-three patients received 50 mg/m2 cisplatin and doses of carboplatin between 160 mg/m2 and 400 mg/m2. Sequential 20-minute infusions of carboplatin and then cisplatin were able to be administered at the standard doses of carboplatin (320 and 400 mg/m2) with thrombocytopenia to the degree expected if carboplatin alone had been given. However, 280 mg/m2 carboplatin followed by 25 mg/m2 cisplatin/d X 3 caused unexpectedly severe thrombocytopenia in seven of eight patients (median platelet nadir 45,000/microL; range, 12 to 321,000/microL; nadir was less than 90,000 in seven of eight patients). In three patients treated with 280 mg/m2 carboplatin plus 25 mg/m2/d X 3 cisplatin, pharmacokinetics of carboplatin were compared during consecutive monthly cycles without and with cisplatin. Modestly increased areas under the curve (AUC) for carboplatin (15% and 35%) with cisplatin were seen in the two patients who experienced more pronounced platelet suppression with combination therapy. No other limiting or unusual toxicity was seen with this combination. Responses, primarily in "platinum responsive" tumors, were seen. The combination of cisplatin plus carboplatin is feasible and merits further study.

Anemia↗
PubMed1987

Phase I study of taxol administered as a short i.v. infusion daily for 5 days.

Taxol inhibits cell division by promoting the assembly and stabilization of microtubules. This report describes the results of a phase I trial of taxol administered as a short iv infusion daily for 5 days every 4 weeks. Sixteen patients with refractory malignancy received 21 courses of taxol at five doses between 5 and 40 mg/m2/day X 5. The first nine patients received taxol as a 60-minute infusion. Two patients experienced anaphylactoid reactions, one at the 5-mg/m2/day and the second at the 15-mg/m2/day X 5 dose levels. These reactions were characterized by facial flushing, tachypnea, and hypotension within several minutes of drug administration. These anaphylactoid reactions occurred on the first day of treatment in the first patient and on the first day of the second course in the second patient. These reactions may be related to the rapid administration of the polyoxyethylated castor oil (Cremophor EL) vehicle in which taxol is formulated. No anaphylactoid reactions were observed in the seven patients who received taxol as a 6-hour infusion with antihistamine and prednisone premedication. Dose-related myelosuppression was seen; leukopenia (wbc count less than 1000/mm3) and granulocytopenia (granulocytes less than or equal to 200/mm3) occurred on Days 8 and 9 in two of two patients treated at the 40 mg/m2/day X 5 level. Thrombocytopenia was mild, with a platelet nadir of 87,000-95,000/mm3 at the highest dose level. Premedication with glucocorticoids and antihistamines coupled with a prolonged 6-hour infusion permitted taxol to be administered at 30 mg/m2/day X 5 safely without immediate life-threatening reactions.

Alkaloids↗
PubMed1986

Metastatic Leydig cell tumor of the testis. Report of three cases and review of the literature.

Metastatic Leydig cell carcinomas account for less than 0.2% of all testicular cancers, and may be associated with sex hormone production. Leydig cell carcinoma is relatively refractory to radiotherapy and chemotherapy, and median survival of patients with metastatic disease is less than 2 years. Presented are three cases of metastatic Leydig cell cancer, and a review of the literature pertaining to this rare tumor.

Adult↗
PubMed1986

Spontaneous remission in diffuse large cell lymphoma.

A case of spontaneous remission in a Stage IIA diffuse large cell lymphoma is presented. Review of the literature suggests that whereas spontaneous regressions are a well-recognized phenomenon in indolent lymphomas, it is extremely rare in lymphomas of aggressive histologic subtype.

Female↗
PubMed1986

Reversible increase in serum alpha-fetoprotein content associated with hepatic dysfunction during chemotherapy for seminoma.

Serial monitoring of the serum content of the beta subunit of human chorionic gonadotropin (beta hCG) and alpha-fetoprotein (alpha FP) is useful in the initial staging of germ cell tumors and assessing the response to treatment. An increase in either marker during or following treatment almost always heralds disease progression and indicates the need for additional therapy. We report two patients in whom substantial increases in the serum content of AFP occurred during chemotherapy for advanced seminoma. Hepatic dysfunction was present in both patients; in one patient, a chronic carrier of hepatitis B virus, the liver dysfunction was associated with reactivation of hepatitis B manifested by anicteric hepatitis and hepatitis B e antigen positivity. Marked tumor regression had occurred in both patients, and chemotherapy was discontinued in spite of the elevated alpha FP level. The alpha FP content in the serum gradually returned to normal, and hepatic dysfunction resolved. Both patients remain free of disease 15 and 17 months following the last chemotherapy treatment. These cases illustrate that hepatic dysfunction and alpha FP production may occur during chemotherapy and that increases in serum alpha FP content must be interpreted with caution since the elevated alpha FP level does not always indicate progression of germ cell tumors.

Adult↗
PubMed1986

Alteration of fluorouracil metabolism in human colon cancer cells by dipyridamole with a selective increase in fluorodeoxyuridine monophosphate levels.

The nucleoside transport inhibitor dipyridamole can increase the cytotoxicity of 5-fluorouracil in a human colon cancer cell line (HCT 116) without affecting the total amount of fluorouracil incorporated into the acid soluble and insoluble fractions (J. L. Grem and P. H. Fischer, Cancer Res., 45: 2967-2972, 1985). We now report that dipyridamole altered the pattern of fluorouracil metabolism and provided a selective increase in intracellular fluorodeoxyuridine monophosphate (FdUMP) levels. At 2 and 4 h after exposure to fluorouracil and dipyridamole, FdUMP levels were approximately 5-fold higher in the presence of dipyridamole. The ratio of FdUMP to fluorouridine triphosphate at 4 h was substantially increased in the presence of dipyridamole (0.4 +/- 0.05) compared to fluorouracil alone (0.08 +/- 0.03). In cells preloaded with fluorodeoxyuridine (FdUrd), dipyridamole potently inhibited the efflux of FdUrd, leading to an increased retention of intracellular FdUMP. One h following removal of [6-3H]FdUrd, the FdUMP levels were increased 8-fold in the presence of dipyridamole, and the half-life of intracellular FdUMP was increased from 24 to 78 min. We have previously shown that the addition of sufficient thymidine (25 microM) can prevent the augmentation of fluorouracil toxicity produced by dipyridamole. In these studies, the addition of 25 microM thymidine reduced the FdUMP levels to less than half of those measured in the presence of fluorouracil plus dipyridamole for the first 8 h of exposure, and reduced the FdUMP levels to 6% of the FdUMP levels seen with fluorouracil and dipyridamole after 24 h of exposure. Thymidine prevented the enhanced intracellular retention of FdUMP produced by dipyridamole in cells preloaded with FdUrd. In addition, thymidine inhibited the accumulation of FdUMP in cells exposed to FdUrd. In cancer cells which significantly catabolize FdUMP, the ability of dipyridamole to block the efflux of FdUrd may provide an effective means of selectively increasing FdUMP levels and enhancing the toxicity of fluorouracil. Furthermore, dipyridamole blocked the efflux of deoxyuridine and prolonged the intracellular half-life of deoxyuridine monophosphate. In cells prelabeled with [2'-3H]dUrd, transfer of tritium to FdUrd and FdUMP occurred in cells exposed to fluorouracil and dipyridamole. These data suggest that blockade of nucleoside efflux can enhance the availability of deoxyribose-1-phosphate donors for the synthesis of FdUrd. Thus, dipyridamole's ability to inhibit nucleoside transport can perturb the metabolism of a nucleobase, fluorouracil.

Cells, Cultured↗
PubMed1986

Treatment of mitomycin-associated microangiopathic hemolytic anemia with vincristine.

A syndrome, including microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and renal insufficiency, has been recognized to occur as a complication of antineoplastic therapy with mitomycin. The clinical presentation can vary from a chronic course with mild anemia and slowly progressive renal dysfunction to a fulminant course with severe anemia, rapid deterioration of renal function, and death. The optimal treatment of the mitomycin-associated MAHA syndrome is unknown. Therapy with steroids, antiplatelet agents, and heparin sodium has failed to reverse the MAHA. Plasmapheresis has improved the MAHA in a few patients without reversing the renal failure. We treated two patients who had MAHA and renal dysfunction during chemotherapy that included mitomycin; the MAHA and hypertension both objectively improved after treatment that included vincristine sulfate.

Acute Kidney Injury↗
PubMed1985

Clinical features and natural history of intramedullary spinal cord metastasis.

Five cases of intramedullary spinal cord metastasis are presented and an additional 50 cases from the English language literature since 1960 are reviewed. Lung cancer and breast cancer were the most frequently occurring primary neoplasms, but a wide variety of solid tumors may cause intramedullary spinal cord metastasis. The presenting symptoms were pain and/or weakness. The neurologic status deteriorated rapidly in the majority of patients in a period to days to weeks. Progression to a cord hemisection syndrome or cord transection occurred in approximately half of the patients. The characteristic myelographic appearance of fusiform swelling of the cord was seen in one third of the patients, but the myelogram was normal in 42%. Plain radiographs of the spine showed no evidence of metastatic disease in three fourths of cases. The cerebrospinal fluid protein level was frequently elevated, but results of cytologic studies were usually negative. High-resolution computer-assisted tomographic scanning may show intramedullary metastases. Radiation therapy combined with corticosteroid administration offers the only effective palliation. The recognition of intramedullary spinal cord metastasis is an ominous finding. Intramedullary spinal cord metastasis generally occurred in the setting of widespread systemic and intracranial disease, but occasionally was the only site of relapse. More than 80% of patients died within 3 months. Heightened awareness of this entity may lead to early diagnosis at a stage when neurologic deficits are reversible and, it is hoped, more effective palliation can be achieved.

Adult↗