Phase I study of high-dose cytosine arabinoside and etoposide in patients with advanced malignancies

Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m² as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m²×2 doses of ara-C and 50 mg/m² of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182     

Body composition of patients with spinal cord injury

Body composition of 10 control subjects and 37 spinal cord injured (SCI) patients was measured by dilution of 3H2O and Na2 35SO4. SCI patients were classified into four groups by ascending level of lesion, low and high paraplegics and low and high quadriplegics. The studies show diminishing total body water, intracellular water, lean body mass and body cell mass and increasing fat mass with higher spinal lesions. No differences in body weight or extracellular water were observed so that the ratio of extracellular water/total body water was increased as the level of injury increased.     

Basal metabolic rate of normal and marginally undernourished mestizo children in Colombia

The basal metabolic rate (BMR) was measured in mestizo children 6-16 years of age living under economically deprived conditions in Colombia. Of a total of 239 boys and 126 girls, 137 boys and 72 girls were classified as marginally malnourished. Differences in BMR by age, sex and nutritional group could be accounted for by differences in lean body mass. The Schofield equations were found to overestimate BMR significantly in the boys. However, the estimates in girls were not significantly different from measured values.     

Absence of Neutral Protease and Alkaline Phosphatase in Neutrophils of a Case of Hairy Cell Leukemia: Appearance After Splenectoniy

Enzymaticaly homogeneous fractions of lymphocytes, monocytes, and neutrophils were isolated by zonal centrifugation from peripheral blood of a patient with hairy cell leukemia, or leukemic reticuloendotheliosis, LRE,(with leukopenia, neutropenia, lymphocytosis, and massive splenomegaly). To detect enzymatic deficiencies, the cells were analyzed quantitatively for six leukocytic enzymes on three occasions: 1) before splenectomy, 2) 5 days after splenectomy, and 3) 6 weeks after splenectomy. Before splenectomy, the patient's cells showed moderate deficiency of β-glucuronidase in lymphocytes and monocytes; server to modorate deficiency of lysozyme and myeloperoxidase in monocytes and granulocytes; and complete absence of neutral protease and alkaline phosphates in neutrophils. Full restoration of neutral protease and a three-fold rise in alkaline phosphatase activities occurred in the patient's neutrophils 5 days after splenectomy. Lysozyme and myeloperoxidase returned to normal in both monocytes and neutrophils of the patient. Six weeks following splenectomy, the alkaline phosphatase activity again disappeared from patient's neutrophils, although neutral protease remained normal. The patient's lymphocytes were unresponsive to PHA and PW mitogen before splenectomy but became responsive 6 weeks postoperatively. Monocytic transfomation into macrophges was supressed before and after splenectomy. The findings indicate that developmenally, in lymphocytic leukemia, a biochemical defect involves the patient's monocytes and neutrophils much more severely than it affects the leukemic lymphocytes. Functionally, the results partly explain the susceptibility of LRE patients to microbial infections.     

Molecular genetics of calcium sensing in bone cells

The molecular mechanisms regulating bone remodelling are only partially understood. One of the controversial issues discussed during the past few years is the role that calcium signalling plays in this process and, in particular, in the functioning of the osteoclast. Calcium is involved in the recruitment and activation of osteoclasts and their subsequent detachment from bone. Parathyroid hormone and vitamin D are part of a systemic mechanism regulating calcium availability, storage and disposal. But there are conflicting results suggesting the presence of a local calcium-sensing mechanism in osteoclasts, in osteoblasts or in both. If this system could be characterized, it would be of therapeutic relevance for diseases such as postmenopausal osteoporosis and rheumatoid arthritis. Genetic data, animal models and cell-based assays have not yet been used to their full extent in this area. Here we review the available data and outline possible future strategies.     

Germline mutations of the CDKN2 gene in UK melanoma families

Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.      

Interrupted versus continuous chemotherapy in patients with metastatic breast cancer. The Piedmont Oncology Association

BACKGROUND. Chemotherapy for metastatic breast cancer is palliative, and the optimal duration of therapy is unknown. We designed a trial to determine whether continuous treatment is superior to stopping treatment after a brief induction period and resuming treatment when the disease progresses. METHODS. We treated 250 women with metastatic breast cancer with six courses of cyclophosphamide, doxorubicin, and fluorouracil given every three weeks. At the completion of this induction period, women whose disease either regressed or remained stable were randomly assigned to receive either continued treatment with cyclophosphamide, methotrexate, and fluorouracil (maintenance therapy) or no further treatment (observation) followed by treatment with cyclophosphamide, methotrexate, and fluorouracil when disease progression became evident (reinduction). RESULTS. The combined rate of complete and partial responses after initial therapy was 30 percent (71 of 233 patients who could be evaluated; 95 percent confidence interval, 25 percent to 37 percent). In another 42 percent (98 patients), the disease remained stable. A total of 145 patients were randomized. Seventy-one were randomly assigned to the maintenance-therapy group, and 74 to the observation group. The median time to progression was 9.4 months for patients in the maintenance-therapy group and 3.2 months for patients in the observation group (P less than 0.001). After reinduction therapy, the median time to progression was 3.5 months. The median length of survival from the time of initial therapy was 14.8 months for all 250 patients; it was 21.1 months for the 71 patients in the maintenance-therapy group and 19.6 months for the 74 patients in the observation group (P = 0.67). Maintenance therapy was the most important determinant of the time before progression (P less than 0.001), but it was not associated with prolonged survival. The changes in performance status were similar in the patients in both groups, but nausea, vomiting, and mucositis were significantly more frequent in the maintenance-therapy group. CONCLUSIONS. In patients with breast cancer who received induction chemotherapy for 18 weeks, subsequent continuous chemotherapy was associated with a significant prolongation of the time before progression as compared with those receiving no further therapy; overall survival, however, was not significantly different in the two groups.     

Skin Conductance Response Conditioning with High CS Intensities: Additional Evidence with New Controls

In an effort to determine whether or not conditioning is possible when CS intensity is at least as high as US intensity, nine groups of human subjects were employed in a skin conductance conditioning study. White noise CS and US intensities of 95- and 115-dB were varied orthogonally in the experimental groups, while control groups were incorporated to control for overall signal frequency and differences in habituation rates attributable to differences in intertrial interval. By conventional contrasts first interval response (FIR) conditioning was observed, but when controls for differential habituation rates were incorporated in the contrasts there was no evidence of FIR conditioning. Second interval response (SIR) conditioning was obtained, but it was manifest as an anticipatory response to the higher of two US intensities rather than in conventional conditioning vs control group comparisons. It was also shown that high CS intensities induce suppression of SIR levels, with greater suppression associated with the higher intensity. Several conclusions were made: 1) in a simple trace conditioning paradigm with skin conductance responding as the measure, it is not clear that what we have typically called a conditioning effect is separable from an habituation effect; 2) conditioning is possible even when CS intensity is as high as or higher than US intensity; and 3) the use of time sample measurement in the absence of signals provides a useful baseline for determining overall increases and decreases in SIR level.     

Informed consent: patient information forms in chemotherapy trials

Documentation of informed consent by patients entering clinical trials is an ethical and legal necessity. Federal regulations and judicial opinions have led to increasingly lengthy, detailed "consent" forms, yet published studies demonstrate that patients remain confused about the nature and anticipated consequences of study entry. It has been suggested that more detail may even alarm or further confuse patients. Seventy-five women undergoing chemotherapy for advanced breast cancer participated in this study which assessed patient preference for long-, medium-, or short-form length, and whether form length preference correlated with patient characteristics or indicators of patient autonomy in decision-making or physician dependency. Patient preferences for information were not predicted by the patient autonomy or physician dependency scores or by age, marital status, or level of education. The majority of patients expressed a preference for more detailed information about their treatment, yet a majority of patients given detailed forms answered questions basic to the study design incorrectly, irrespective of educational level. The increased detail included in the long forms was not reported to increase stress compared to the short forms. Patient information forms are a principal tool for informing patients for consent but if they are to perform their desired function they must be designed more carefully and evaluated more thoroughly than in the past.