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Biomedical subjects

C K Daugherty

Publications and source records attributed to C K Daugherty.

14 recordsLinked to original sources

Psychosocial adjustment of patients and caregivers prior to allogeneic bone marrow transplantation.

There are many studies that examine the psychosocial adjustment of survivors of bone marrow transplantation (BMT). On the other hand, there are relatively few studies that examine the psychosocial adjustment of patients prior to BMT, and even fewer that focus on the psychosocial adjustment of the patient's caregiver. The purpose of the present study was to assess performance status and psychosocial adjustment to illness, mood and stress response of patients and caregivers prior to admission for allogeneic BMT. Forty patients and their 39 caregivers were assessed using standardized measures. One-fourth of the patients reported clinical levels of psychosocial maladjustment on the Psychosocial Adjustment to Illness Scale and had greater adjustment problems than BMT survivors. Approximately one-third (35%) and one-quarter (23%) of the patients reported significant symptoms of intrusive and avoidance stress responses, respectively on the Impact of Events Scale. Caregivers reported more impairments in family relationships than patients, but overall reported similar distress to that of patients. Information about the pre-BMT process appears to be critical to understanding the psychosocial impact that BMT can have on patients and their caregivers.

Adult↗

Preliminary experience with a new chemotherapy regimen for adults with acute lymphoblastic leukemia.

We treated 11 consecutive adult patients who presented with acute lymphoblastic leukemia to the University of Chicago with a novel, intensified chemotherapy regimen to evaluate the feasibility and toxicity of this program. Following a 5-drug induction therapy (course A), patients received sequential courses (B and C) of high-dose antimetabolite therapies, in part to replace cranial irradiation for CNS prophylaxis. All patients achieved a complete remission. The regimen was designed with a goal of administering all post-remission therapy in the outpatient setting. With the exception of the initial induction course (A), 3(1/3)8 total patient courses were administered in the outpatient clinic. As expected, the induction and consolidation courses (A and B) of this regimen were associated with grade 4 hematologic toxicity and significant but manageable infectious toxicity. Another novel aspect of the regimen included a combined intravenous and oral dosing schedule designed to sustain methotrexate levels > or = 1.0 microM for 30 hours (course C). There was minimal toxicity with the CNS prophylaxis/high-dose methotrexate course (C). Methotrexate levels at 30 hours ranged from 0.31-4.0 microM, with a median of 1.0 microM (n=37). This study demonstrates that this novel post-remission regimen is feasible in adults and that high concentrations of methotrexate can be sustained in the outpatient setting. The Cancer and Leukemia Group B is presently evaluating the efficacy of this regimen in a large phase II trial (CALGB study 19802).

Adult↗

A dose escalation study of total body irradiation followed by high-dose etoposide and allogeneic blood stem cell transplantation for the treatment of advanced hematologic malignancies.

Since approximately 30% of leukemia patients relapse after allogeneic BMT using total body irradiation (TBI)-based preparative regimens, treatment intensity may be suboptimal. The killing of leukemia cells is proportional to the radiation absorbed dose. We studied the feasibility and toxicity of escalating the doses of fractionated TBI above our previous prescription of 13.5 Gy. Sixteen evaluable patients with advanced hematologic malignancies were treated with twice daily TBI using a high-energy source (18-24 MV). The first patient cohort (n = 11) received a total dose of 14.4 Gy in nine fractions, and the second cohort (n = 5) received doses escalated to 15.3 Gy. All patients received high-dose etoposide (60 mg/kg) and allogeneic stem cell transplantation following the TBI. All patients had HLA-identical sibling donors. The median times for neutrophil and platelet engraftment were 13.5 and 12 days, respectively, and did not differ between the two cohorts. All but one patient developed treatment-related grade 3 or 4 mucositis. There were three cases of grade 4 pulmonary toxicity and three cases of grade 4 hepatic toxicity among the 14.4 Gy cohort, and one case each of grade 4 pulmonary and hepatic toxicities among the 15.3 Gy cohort. In most cases comorbid conditions contributed to these toxicities. Two patients had significant GVHD of the GI tract. Six relapses occurred, five (45%) in the 14.4 Gy cohort and one (20%) in the 15.3 Gy cohort. The 100-day treatment-related mortality rates were 9% and 20% for the 14.4 Gy and 15.3 Gy cohorts, respectively, and the median survivals were 226 and 201 days, respectively. We conclude that TBI dose escalation above the previously used 13.5 Gy dose is feasible using a high-energy source and high-dose etoposide. Acute and chronic toxicities were primarily related to GVHD, infection and relapse rather than to TBI.

Adult↗

Ethical issues in the development of new agents.

In the early drug development process for cancer therapy, several ethical dilemmas result from the use of cancer patients with advanced disease as the subjects of research in clinical trials studying agents of unknown toxicity and/or efficacy. Although several accepted ethical principles guide the behavior of involved physicians and investigators, many of these principles are allowed to be violated in order to achieve the overall goal of clinical research in improving medical care for future patients. Informed consent has been a process viewed by many as a mechanism which protects potentially vulnerable patients from harm in the clinical trial process. However, the ability of the traditionally regulated process of obtaining informed consent for clinical research may be inadequate to ensure appropriate understanding of the purposes and the goals of early clinical trial research by potentially vulnerable advanced cancer patients. This creates further dilemmas with regard to physician-investigator and patient-subject communications. In the setting of phase I trials, where the specific goal of the research is to obtain toxicity information regarding a new potential anticancer agent, many heightened ethical conflicts are present. The fact that patients do not participate in these studies as a result of altruism, and that their main goals of participation are intensely therapeutic, create issues that may be in direct conflict with the research purpose of phase I trials. As well, the presence of therapeutic intentions on the part of involved physician-investigators creates challenging issues when one realizes the very low likelihood of benefit for individual patients participating in these studies. Within the phase II setting, the statistical constraints placed on new drug trials and, again, the low likelihood of benefit for participating-subjects, also creates challenging dilemmas. These statistical requirements may be in direct conflict with involved clinicians' attitudes and beliefs regarding potential efficacy of an agent in this setting. As well, these issues become problematic when thinking about the desired structure and outcome for informed consent in phase II anticancer trials. The ability to conduct clinical research on advanced cancer patients using agents of unknown efficacy and toxicity is a daunting privilege granted to physicians and accompanying institutions. The weight of this privilege should not be underestimated, and involved physician-investigators should be aware of the significant ethical challenges involved in appropriately and successfully conducting this form of research.

Antineoplastic Agents↗

Impact of therapeutic research on informed consent and the ethics of clinical trials: a medical oncology perspective.

PURPOSE: To create a more meaningful understanding of the informed consent process as it has come to be practiced and regulated in clinical trials, this discussion uses the experience gained from the conduct of therapeutic research that involves cancer patients. DESIGN: After an introduction of the ethical tenets of the consent process in clinical research that involves potentially vulnerable patients as research subjects, background that details the use of written consent documents and of the term "informed consent" is provided. Studies from the cancer setting that examine the inadequacies of written consent documents, and the outcome of the consent process itself, are reviewed. Two ethically challenging areas of cancer clinical research, the phase I trial and the randomized controlled trial, are discussed briefly as a means of highlighting many dilemmas present in clinical trials. Before concluding, areas for future research are discussed. RESULTS: Through an exclusive cancer research perspective, many current deficiencies in the informed consent process for therapeutic clinical trials can be critically examined. Also, new directions for improvements and areas of further research can be outlined and discussed objectively. The goals of such improvements and research should be prevention of further misguided or ineffective efforts to regulate the informed consent process. CONCLUSION: To ignore this rich and interesting perspective potentially contributes to continued misunderstanding and apathy toward fulfilling the regulatory and ethically obligatory requirements involved in an essential communication process between a clinician-investigator and a potentially vulnerable patient who is considering clinical trial participation.

Clinical Trials as Topic↗

Study of cohort-specific consent and patient control in phase I cancer trials.

PURPOSE: To address the challenging ethical dilemmas created from the participation of advanced cancer patients in phase I trials, we assessed the feasibility of a clinical trial design that uses an interactive informed consent process in which patient-subjects can choose to become directly involved in decisions of dose escalation. PATIENTS AND METHODS: Subjects were advanced cancer patients in the Hematology/Oncology Clinics at the University of Chicago who were eligible to participate in a phase I trial in which they underwent a three-step informed consent process that used cohort-specific consent and allowed them the option to choose their own doses of the chemotherapeutic agents under study, vinorelbine (NVB) and paclitaxel (TAX), within predetermined limits. NVB and TAX were administered in conventional 21- to 28-day cycles for two cycles while on study. Dose escalation occurred when a patient-subject chose a higher untested dose after they received information on all previously assessable patient-subjects. In addition to the phase I trial itself, a survey that consisted of structured interviews, which sought to evaluate patients' experiences with the interactive subject-choice phase I trial design and consent process, was conducted with participating subjects. The phase I trial itself sought to determine the associated toxicities of the agents under study. The survey results were compared with a similar survey of a matched control population of subjects who participated in other concurrently active conventional phase I trials at our institution. RESULTS: Twenty-nine patient-subjects participated in the phase I trial, with 24 who agreed to and completed the survey interviews. Seventy-six percent of patient-subjects opted to choose their dose of the agents under study, and 28% chose the highest available doses. More than half of the patient-subjects (56%) felt some degree of comfort in being asked to choose their dose of chemotherapy, with 53% stating that being asked to choose their dose made them feel in control, fully informed, or content. However, there were no statistically significant improvements in objective measures of the informed consent process, which included surveyed subjects' stated understanding of either provided information about phase I trials and alternatives to trial participation or of the research purpose of phase I trials. By making choices, the group of patients in the interactive subject choice trial changed the size of the dose cohorts and modified the process of dose escalation in this phase I study. CONCLUSION: Although complex, our innovative phase I trial design is feasible. In addition to the use of cohort-specific consent, the trial design may reduce the magnitude of many of the commonly recognized ethical dilemmas associated with this form of clinical research, which include difficulties with information provision and the understanding of possible risks and benefits of phase I trial participation, through direct subject involvement in research decision making by otherwise potentially vulnerable cancer patients.

Adult↗

Learning from our patients: one participant's impact on clinical trial research and informed consent.

This Perspective includes an essay on modifying phase I clinical trials, written by George Zimmer, who was a professor of English and a commentary on that essay. Professor Zimmer was a cancer patient who participated in the phase I clinical trial program at the University of Chicago. His ideas are eloquently expressed and have had a profound effect on our investigational research for anticancer agents. Although at times his suggestions may seem radical, Professor Zimmer urges us to reconsider the 50-year-old Nuremberg paradigm that participants in human research are ignorant and vulnerable and must be protected. Although we must protect patients who have life-threatening diseases from coercive inducements and misplaced hopes, we must also listen carefully and thoughtfully to our patients. This is particularly true when, as research participants in the face of sacrifice and the threat of a life-ending diagnosis, they have made the effort to express their concerns. With the effect of the acquired immunodeficiency syndrome movement on clinical studies and on drug research and development, a precedent has been set that allows patients to reshape their role as participants in research trials. On a personal level, the essay by Professor Zimmer has had a significant effect on our research methods and, indeed, the focus of our research efforts. Thus, it is with a sense of respect and honor that we share George Zimmer's thoughts and our comments about the influence he has had on our research practices.

Acquired Immunodeficiency Syndrome↗

Allogeneic bone marrow transplantation for relapsed and refractory Hodgkin's disease and non-Hodgkin's lymphoma.

The relative benefit of allogeneic bone marrow transplantation (alloBMT) vs autologous BMT (autoBMT) for patients with relapsed or refractory Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) remains uncertain. Toxicity from graft-versus-host disease (GVHD) may diminish the potential benefits both of graft-versus-tumor activity and of receiving uncontaminated donor marrow stem cells. From 1987 to 1995, 27 adults (ages 18-60 years; median 36) underwent alloBMT for lymphoma after failure of standard chemotherapy. Twenty-one had NHL and six had HD (nodular sclerosis). Thirteen patients had primary refractory disease or chemotherapy-resistant relapses; two of these had relapsed after autoBMT. Three patients had untested relapses (one of them had relapsed after autoBMT), and 11 had chemotherapy-sensitive relapses. Twenty-four received HLA-matched bone marrow from a sibling (one twin); three received haploidentical marrow cells. Nine (33%) died from lymphoma. Eleven (41%) died of treatment-related causes. Opportunistic infections were a substantial problem leading to eight of these deaths (30%). Six patients (22%) survive free of lymphoma 17-70 months post-BMT (median, 56 months); four had had sensitive relapses, one had had a resistant relapse, and one had had nontested relapse. Three have chronic GVHD (limited in one; extensive in two). One HD patient who had relapsed after autoBMT remains in remission 19 months after alloBMT. No therapy-related myelodysplasia has been observed. We conclude that alloBMT has substantial morbidity in heavily pretreated lymphoma patients due to acute toxicity, infections and GVHD. However, 22% of our HD/NHL patients have had long-term disease-free survival.

Adolescent↗

Regional effects of hypoxia and hypothermia on rebound excitation in large intestine of piebald mouse model for Hirschsprung's disease.

Effects of hypoxia and hypothermia on the poststimulus rebound contractile response (PSRR) were studied in the circular muscle coat of the large intestine of the piebald mouse model for Hirschsprung's disease. The PSRR in the terminal segment of the normal large intestine, which corresponds to the aganglionic segment of the piebald mice, was found to be much more resistant to hypoxia than more proximal regions of the bowel. Effects of hypoxia on the PSRR of megacolonic preparations from piebald mice were essentially the same as for the proximal and midcolon of normal mice. The exception was an increase in latency for the PSRR in the intestine of diseased animals that did not occur in the preparations from normal littermates. Effects of hypothermia, unlike hypoxia, were not markedly different in the proximal and distal large intestine. The latency and duration of the PSRR were increased during hypothermia while the amplitude decreased in all ganglionated regions of large intestinal preparations from both piebald mice and their normal siblings. This was interpreted to result from suppression of inhibitory neuronal activity. The results suggest that the capacity for anerobic metabolism within the neuromuscular apparatus responsible for the PSRR is greater in the terminal large intestine than in the proximal and midcolon.

Animals↗