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Biomedical subjects

J S MacDonald

Publications and source records attributed to J S MacDonald.

At least 55 records · Page 3Linked to original sources

Detection of breast carcinoma metastases in bone: relative merits of X-rays and skeletal scintigraphy.

Of 1116 patients receiving primary treatment for breast carcinoma at the Royal Marsden Hospital since 1976, 651 had an abnormal bone scintigram either at primary diagnosis (378) or on subsequent follow-up (273) and 167 developed radiographically detectable bone metastases (21 at the time of primary diagnosis). Comparison of bone scintigrams and X-rays showed that scintigraphy was an inaccurate localiser of existing radiographic detectable metastases. If X-rays alone are used to detect bone metastases a limited examination with five plates will detect metastases with 92% accuracy. After primary surgery, routine X-ray screening for bone metastases is not necessary since it is possible to identify patients at risk on the basis of clinical examination, chest X-ray, and serum alkaline phosphatase and gamma-glutamyl transpeptidase levels.

Alkaline Phosphatase↗

The effect of sequential addition of the nitrosourea, chlorozotocin, to the FAM combination in advanced gastric cancer.

Twenty-three patients with advanced measurable gastric cancer were treated with FAM-chlorozotocin in an attempt to demonstrate improvement in rate and duration of response over FAM (5-fluorouracil, Adriamycin and mitomycin C). Six (26%) partial responses were recorded with a median duration of two months. FAM-chlorozotocin was well tolerated with moderate myelosuppression as the major dose-limiting toxicity; the leukocyte nadir was 3.0 X 10(3)/mm3 (range, 0.9-6.0) and the platelet nadir was 100 X 10(3)/mm3 (range, 45-100). The authors were unable to find significant differences in prognostic factors such as performance status, sites of metastatic disease, intensity of therapy to account for the discrepancy in response rates between FAM (42%) and FAM-chlorozotocin (26%).

Adult↗

Mevalonate supplementation in pregnant rats suppresses the teratogenicity of mevinolinic acid, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme a reductase.

Mevinolin is a fungal metabolite, and in the hydroxyacid form, mevinolinic acid, it is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-Co A) reductase, an enzyme essential in cholesterol biosynthesis. Oral administration of 800 mg/kg/day of mevinolin to rats from days 6 through 17 of gestation produced fetal malformations of the vertebrae and ribs in 29% of the litters, and there was a treatment-related increase in the incidence of gastroschisis. Mevinolinic acid at 60 and 90 mg/kg/day also produced fetal malformations of the vertebrae and ribs, and these teratogenic manifestations were markedly suppressed by coadministration of the product of HMG-Co A reductase, mevalonic acid, at a dosage level of 500 mg/kg b.i.d. A diet supplemented with 0.5% or 1.0% cholesterol had no effect on the teratogenicity of mevinolinic acid. Teratology studies in rats with a dihydroxyheptanoic acid derivative of mevinolin, a compound 1/700 as potent as mevinolinic acid as an inhibitor of HMG-Co A reductase, and dihydromevinolinic acid, an inhibitor of this enzyme comparable in activity to mevinolinic acid, indicated that the teratogenicity of these compounds was related to their relative enzyme inhibitory activity. The dihydroxyheptanoic acid derivative was not teratogenic at doses as high as 150 mg/kg b.i.d.; in contrast, when dihydromevinolinic acid was administered at 50 and 100 mg/kg/day, its potency as a teratogenic agent was comparable to that of mevinolinic acid. These studies demonstrated that inhibitors of HMG-CoA reductase produced terata in rats and that the teratogenic effects could be antagonized by coadministration of the enzyme product, mevalonic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗

Tumorigenicity of 7,12-dimethylbenz[a]anthracene, its hydroxymethylated derivatives and selected dihydrodiols in the newborn mouse.

The newborn mouse lung adenoma model has been shown to be a sensitive test for studying the tumorigenicity of bay region diol epoxides and their precursor dihydrodiols. When a total dose of 28 nmol of 7,12-dimethylbenz[a]anthracene (DMBA) or its derivatives was injected i.p. into the preweaning mice, it was found that the 3,4-dihydrodiols of both DMBA and 7-hydroxymethyl-12-methylbenz[a]anthracene caused 13.3 and 4.1 times more lung adenomas than DMBA, respectively. The mice treated with the 5,6- and 8,9-dihydrodiols of DMBA, 7-hydroxymethyl-12-methylbenz[a]anthracene and its 5,6- and 8,9- and 10,11-dihydrodiols, 7-methyl-12-hydroxymethylbenz[a]anthracene and 7,12-dihydroxymethylbenz[a]anthracene developed a level of lung adenomas/mouse less than 2-fold higher than that found in the DMSO-treated control group. Liver tumors also developed in some of the mice. The percentage of mice with liver tumors also indicated that the 3,4-dihydrodiols of both DMBA and 7-hydroxymethyl-12-methylbenz[a]anthracene were more tumorigenic than DMBA itself. These data indicate that the 3,4-dihydrodiols of both DMBA and its 7-hydroxymethyl derivative may be proximate carcinogenic metabolites of DMBA in the newborn mouse.

9,10-Dimethyl-1,2-benzanthracene↗

5-fluorouracil, Adriamycin, and mitomycin-C (FAM) chemotherapy for advanced adenocarcinoma of the pancreas.

Thirty-nine patients with advanced metastatic adenocarcinoma of the pancreas were treated with a combination of 5-fluorouracil, Adriamycin, and mitomycin-C (FAM). Twenty-seven of these patients had measurable disease, and ten (37%) achieved a partial response. An additional three patients had evidence of disease stabilization. The median survival period of responding patients was 12 months, compared with 3.5 months for nonresponders (P < 0.01). The median survival period for all patients was 6 months. Moderate myelosuppression constituted the treatment-limiting toxicity. The FAM combination is an active and well-tolerated regimen for pancreatic cancer and may have an application in the management of patients with less advanced disease.

Adenocarcinoma↗

5-Fluorouracil, doxorubicin, and mitomycin (FAM) combination chemotherapy for advanced gastric cancer.

Sixty-two patients with advanced measurable gastric cancer were treated with a combination chemotherapy program of 5-fluorouracil, doxorubicin, and mitomycin (FAM). Forty-two percent of patients achieved an objective partial response. The median duration of remission was 9 months and the median survival for responding patients, 12.5 months. The median survival for nonresponding patients was 3.5 months; all patients were dead by 8 months after initiation of therapy. The median survival of all 62 patients treated with FAM was 5.5 months. An analysis of possible prognostic variables including initial performance status, resectability of the primary gastric tumor, and histologic differentiation of the neoplasm failed to account for differences in patient response and survival. The FAM regimen was well tolerated, producing only moderate bone marrow suppression. These results show that patients with metastatic gastric cancer can be effectively palliated with FAM chemotherapy. The efficacy of this regimen should now be tested in patients with less advanced stages of this disease.

Adenocarcinoma↗

Regulatory role of glutathione and soluble sulfhydryl groups in the toxicity of adriamycin.

Adriamycin (ADR) has been shown to produce free radicals in NADPH microsomal systems, to increase oxygen consumption of both hepatic microsomes and heart sarcosomes and to stimulate superoxide formation in cardiac, submitochondria particles. These reactive products could produce the cardiotoxicity of ADR by oxidizing various membrane structures, especially if the heart lacks sufficient protective reducing substances such as thiols. We examined 1) the effect of ADR on reduced glutathione (G-SH) levels in various tissues including heart, 2) the ability of the sulfhydryl (SH) donor, cysteamine, to alter soluble SH levels in heart tissue after ADR administration and 3) the effects of SH donors (cysteamine and N-acetyl cysteine and G-SH depletion by diethyl maleate on ADR-induced lethality in Swiss ICR-HA mice. A single injection of ADR (15 mg/kg i.p.) elicited a statistically significant fall in liver (P < .05), heart (P < .02) and erythrocyte (P < .01) G-SH levels. Treatment with cysteamine protected against the fall in soluble SH groups in heart tissue. Cysteamine (50 mg/kg, i.p., every 8 hr for 6 days) or N-acetylcysteine (100 mg/kg, i.p., 1 hr before and 7 hr after ADR) protected against ADR-induced lethality and decreased the appearance of microscopic myocardial lesions. When endogenous levels of G-SH were depleted by diethyl maleate (300 mg/kg i.p., every 8 hr for 4 days), ADR lethality was markedly potentiated. Diethyl maleate alone did not cause death. We conclude 1) ADR significantly lowers G-SH levels in erythrocytes, liver and heart tissue, 2) the lowering of cardiac SH groups by ADR can be prevented by cysteamine and 3) ADR toxicity can be potentiated by diethyl maleate, a G-SH depletor, and reduced by cysteamine or N-acetyl cysteine, SH donors. These results suggest that the G-SH system may be involved in the modulation of ADR-induced toxicity.

Animals↗

5-Fluorouracil, adriamycin, and mitomycin-C (FAM) chemotherapy for adenocarcinoma of the lung.

Twenty-five patients with advanced measurable adenocarcinoma of the lung were treated with combination chemotherapy consisting of 5-fluorouracil, adriamycin, and mitomycin-C (FAM). Objective response (1CR, 8PR) was obtained in 36% of patients. The median duration of response was 7.0 months and the median survival for responders is greater than 8.5 months. Five responders are alive 5.5 to 23.5 months after starting therapy. Three of four patients evidencing stabilization of disease are alive at 10-23 months. Non-responding patients had a median survival of 2.5 months and none lived beyond seven months. Tumor response and survival suggested correlation with initial performance status and limited disease. The FAM regimen was tolerated well, with moderate bone marrow suppression and gastrointestinal symptoms being the only clinically significant toxicities. These results indicate that patients with advanced pulmonary adenocarcinoma can obtain objective tumor regression with FAM chemotherapy.

Adenocarcinoma↗

5-fluorouracil, adriamycin, and mitomycin-C (FAM) combination chemotherapy in the treatment of advanced gastric cancer.

Thirty-six patients with advanced measurable gastric cancer were treated with a new combination chemotherapy program consisting of 5-fluorouracil, Adriamycin and mitomycin-C (FAM). Fifty percent of patients achieved an objective partial response. The median duration of remission was 9.5 months and the median survival for responding patients was 13.5 months, with 2 remaining alive at 14 and 26 months. The median survival for nonresponding patients was 3.0 months and all were dead by 6 months after initiation of therapy. The median survival of all 36 patients treated with FAM was 5.5 months. An analysis of possible prognostic variables including initial performance status, resectability of the primary gastric tumor and histologic differentiation of the neoplasm failed to account for differences in patient response and survival. The FAM regimen was well tolerated, and produced only moderate bone marrow suppression. These results demonstrate that some patients with advanced gastric cancer can be effectively palliated with FAM chemotherapy. Phase III trials are warranted to assess the effect of the FAM regimen on the survival of patients with advanced gastric cancer.

Adenocarcinoma↗

A phase II trial of ftorafur: adriamycin and mitomycin-C (FAM II) in advanced gastric adenocarcinoma.

Fifteen patients with advanced gastric cancer were treated with the combination of Ftorafur, Adriamycin and mitomycin-C (FAM II). Three patients showed partial responses, in five the disease remained stable for at least 3 months and seven showed progression while on treatment. All responding patients showed survival in excess of 12 months. Hematologic toxicity was of only moderate severity. Median white count nadir was 3500 cells/mm3 and median platelet nadir was 187,000 cells/mm3. Four patients had white count nadirs from 2000--2500 cells/mm3 and three had nadirs from 500--1500 cells/mm3; also there were four with platelet nadirs less than 100,000/mm3. However, no drug-related infections occurred and no platelet transfusions were required. The major non-hematologic toxicities of the regimen were nausea, vomiting, dizziness, vertigo, and rhinorrhea. These toxicities were limiting and resulted in termination of the trial because of poor patient acceptance and the failure of the combination to exhibit a therapeutic advantage over the similar combination (FAM) that employed weekly 5-fluorouracil in place of Ftorafur.

Adenocarcinoma↗

The role of computed tomography in the staging of bladder cancer.

Computed tomography of the pelvis has been performed in 60 patients with epithelial bladder tumours. The CT findings have been compared with the clinical staging (T-stage), lymphography (N-stage) and wherever possible the surgical staging (P-stage). Although the intraluminal tumour was visualised in a high proportion of examinations, the greatest value of CT is in the accurate delineation of the extravesical extension of the growth. This is likely to be the primary role of CT in the staging of bladder cancer. Difficulties in detecting invasion of contiguous organs, particularly the prostate, and the failure to demonstrate nodal involvement within the pelvis were noted. The technique has clear advantages over more invasive investigations and the additional information provided over and above clinical staging is seen as a major advance in the assessment of these tumours.

Aged↗