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Biomedical subjects

L Ford

Publications and source records attributed to L Ford.

At least 55 records · Page 3Linked to original sources

The role of thematic evaluation in program assessment: the case of the Community Clinical Oncology Program.

The evaluation of programs with multiple, and potentially conflicting, goals requires the integration of measures of goal achievement that often are not easily combined. One approach is the development of analytical themes which span the various goals of a particular program. The themes provide a mechanism by which the policy concerns of individuals with varying perspectives can be integrated into the evaluation framework. As well, the themes allow for flexibility in the development of new analysis as the program matures and environments change. This paper describes the application of the thematic approach to the evaluation of a complex, community-oriented cancer research program.

Clinical Trials as Topic↗

Cloning of spiramycin biosynthetic genes and their use in constructing Streptomyces ambofaciens mutants defective in spiramycin biosynthesis.

Several cosmid clones from Streptomyces ambofaciens containing the spiramycin resistance gene srmB were introduced into S. fradiae PM73, a mutant defective in tylosin synthesis, resulting in tylosin synthesis. The DNA responsible for this complementation was localized to a 10.5-kilobase EcoRI fragment. A 32-kilobase DNA segment which included the srmB spiramycin resistance gene and DNA which complemented the defect in strain PM73 were mutagenized in vivo with Tn10 carrying the gene for Nmr (which is expressed in Streptomyces spp.) or in vitro by insertional mutagenesis with a drug resistance gene (Nmr) cassette. When these mutagenized DNA segments were crossed into the S. ambofaciens chromosome, three mutant classes blocked in spiramycin synthesis were obtained. One mutant accumulated two precursors of spiramycin, platenolide I and platenolide II. Two mutants, when cofermented with the platenolide-accumulating mutant, produced spiramycin. Tylactone supplementation of these two mutants resulted in the synthesis of a group of compounds exhibiting antibiotic activity. Two other mutants failed to coferment with any of the other mutants or to respond to tylactone supplementation.

Chromosomes, Bacterial↗

Association of MS Pi phenotype with airway hyperresponsiveness.

Asthmatic families (AFs) and normal families (NFs) were studied to determine the relationship between bronchial hyperresponsiveness and alpha 1-antitrypsin protease inhibitor phenotype. We studied IgE levels, skin test scores, and methacholine sensitivity. In both the AF and NF groups, the subjects with the MS phenotype had significantly greater methacholine-induced bronchial hyperresponsiveness sensitivity than the MM and MZ subjects. These findings suggest that the S allele may be associated with bronchial hyperresponsiveness.

Adolescent↗

Evaluating organizational design to assure technology transfer: the case of the Community Clinical Oncology Program.

Current theories of organizational performance are used to guide researchers at the Health Services Research Center of the University of North Carolina at Chapel Hill and the University of Illinois Survey Research Laboratory in the evaluation of the National Cancer Institute's Community Clinical Oncology Program (CCOP) and to derive policy options to enhance program operations. CCOP represents an innovative mechanism designed to improve the accrual of patients to phase III clinical trials, involve community-based oncologists in clinical research, and potentially to disseminate new information on the state-of-the-art cancer treatment to areas distant from cancer centers and research-oriented medical centers. Examined in this evaluation of the second phase of the CCOP are the ability of the 52 currently funded CCOPs and 17 research bases to accrue patients to cancer treatment and cancer control research protocols, their influence on the patterns of practice for cancer treatment in CCOP communities, and their influence on cancer control awareness and activity among primary care physicians. The evaluation applies selected organizational perspectives to describe the intraorganizational and interorganizational characteristics of the CCOPs, research bases, and the Institute that may affect the performance of the CCOP. This organizational approach relates the accrual and influence of the CCOP to controllable aspects of the program's design and management strategies that can be changed through policies directed by the National Cancer Institute. These policies include the criteria used to select CCOPs, the role of research bases in the development and implementation of treatment and cancer control research protocols, and the use of accrual credits.

Academies and Institutes↗

Synthesis and biological properties of the lipophilic technetium-99m complex 99mTc(acac)3.

In the development of technetium-99m radiopharmaceuticals for the evaluation of regional cerebral perfusion, one series of complexes that has remained unexplored is the neutral lipophilic tris complexes formed with beta-diketonato ligands. The prototype complex of this series, tris(2,4-pentanedionato) technetium(III), has been prepared via a new synthetic route and chemically characterized using 99Tc and the biodistribution of the no-carrier-added 99mTc complex has been determined. The 99mTc complex was found to be distributed throughout the body with persistent high blood levels indicative of a high degree of protein binding. The primary route of excretion was the hepatobiliary system as indicated by the appearance of 99mTc in the gut and feces at longer sample times post-injection. Although this complex was not retained by the brain, it does provide a starting point from which a more effective agent might be developed.

Animals↗

Cerebral hemiatrophy--correlation of human with animal experimental data.

We report the neuropathologic findings in a 63-year-old white male with a history of birth asphyxia, cerebral palsy, seizures and mild mental retardation in conjunction with similar brain pathologic findings in animal models of perinatal asphyxia. The human case showed a left cerebral hemispheric hemiatrophy associated with an extensive ulegyria involving all cerebral lobes on that side and a single microscopic focus of cortical atrophy in the right hemisphere. Among a large number of experimental perinatal asphyctic exposures only an occasional animal, like the human case described, showed unilateral hemispheric injury with softening and necrosis if examined early and ulegyria with hemispheric hemiatrophy if examined late. The present paper suggests that perinatal asphyxia under specific pathophysiologic conditions may cause unilateral brain injury. Our experimental studies suggest the specific condition of perinatal asphyxia potentially causing unilateral or asymmetrical brain damage is marked hypoxemia combined with substantial reductions in blood pressure but without circulatory collapse. Given these conditions, the asymmetry of the brain damage likely reflects fetal head position within the gravitational field relative to the heart. With disturbed cerebral blood flow autoregulation from asphyxia, the gravitational field likely accentuates the ischemia of those brain areas most elevated above the level of the heart. Thus, we postulate head position may play a pivotal role in defining brain regions that are damaged in hypotensive perinatal asphyxia. This interpretation may affect the intensive care of hypoxemic, hypotensive newborns aimed at minimizing the risk of brain damage.

Animals↗

Studying patterns of cancer care: how useful is the medical record?

Records of hospital inpatients were abstracted for 5,000 newly diagnosed cancer patients admitted in 1982-83 to 17 Comprehensive Cancer Centers and 17 Community Hospital Oncology Programs. Generally available data items (silent record rate less than 5 per cent for the typical institution) included: age, race, sex, dates of hospitalization, zip code of residence, pathological stage, dates of biopsy and surgery, numbers of nodes examined and positive, certain diagnostic procedures, and some radiotherapy descriptors. For other data items, there was enormous variability in completeness and high institution-to-institution variation. Record completeness did not differ consistently between comprehensive and community cancer centers. We conclude that the hospital patient record is useful for tracking the frequency of surgical and related events. However, studies of diagnostic and therapeutic procedures should not rely solely on the hospital medical record due to the high rates of silent records.

Cancer Care Facilities↗

The effect of age on the care of women with breast cancer in community hospitals.

We studied the process of care received by 1,680 female breast cancer patients treated in 17 community hospitals. The probability of receiving various diagnostic, consultation, therapy, or rehabilitation services was almost always significantly associated with patient age for one or more disease stages. Most often there was a linear trend for older patients to receive fewer services (e.g., biopsies prior to definitive treatment, number of lymph nodes examined, chemotherapy, radiation therapy) but other age patterns also were found. Age was not significantly associated with clinical staging or estrogen receptors.

Adult↗

Selection factors in clinical trials: results from the Community Clinical Oncology Program Physician's Patient Log.

Between August 1984 and November 1985, data concerning 44,156 newly diagnosed cancer patients were entered in the Community Clinical Oncology Program Physician's Patient Log. Forty percent (17,773 patients) had a National Cancer Institute-approved protocol available for site and stage of disease. Fifty-six percent of patients with a protocol available were clinically eligible and 19% were entered on protocol. Thus, one-third of clinically eligible patients were entered in the study. Age was a major factor influencing eligibility and entry on study. Eighty percent of patients less than 25 years of age with a protocol available were clinically eligible for clinical trials participation, and 58% were placed on protocol. Patients greater than or equal to 65 years of age with a protocol available were less likely to be clinically eligible (48%) or placed on study (14%). A physician's preference for an alternate treatment and patient refusal for protocol treatment were also important reasons that clinically eligible patients were not registered on protocol. Selection for clinical trials participation affects the characteristics of patients under study and may have an impact on the ability to generalize the results of clinical trials.

Adult↗

Lateralized brain damage, sex differences, and the Wechsler Intelligence Scales: a reexamination of the literature.

Recent reviews have suggested that males and females show different patterns of intellectual impairment following lateralized brain injury. As the percentage of males in such studies increases, the magnitude of the difference between Verbal and Performance IQs increases. The present review reexamines this literature. Although the association between patient sex, pattern of intellectual deficit, and lateralized brain injury is reconfirmed for studies which used the Wechsler-Bellevue Intelligence Scale, there was no such relationship in those which used the more recent Wechsler Adult Intelligence Scale. In addition, it is shown that, in studies which used the former measure, the percentage of males may be highly correlated with other variables, a relationship which could have an effect on the pattern of intellectual loss following brain injury.

Adult↗

Hyperviscosity caused by hyaluronic acid in serum in a case of Wilms' tumor.

We describe the case of a three-year-old girl with Wilms' tumor, whose serum showed at least a fivefold increase in relative viscosity although concentrations of albumin and immunoglobulins were normal. An unusual electrophoretogram of serum protein prompted further investigation. The increased viscosity was caused by the presence of high concentrations of hyaluronic acid, a glycosaminoglycan normally not detectable in serum.

Blood Protein Electrophoresis↗