Some reasons for the lack of progress in the treatment of acute myelogenous leukemia: a review of three consecutive trials of the treatment of poor prognosis patients

The failure of three consecutive treatment protocols to significantly increase the complete remission rate for poor prognosis newly diagnosed patients with acute myelocytic leukemia led to a detailed investigation of the causes of treatment failure. In the majority of cases treatment failure was attributable to "clinical resistance" to therapy. Upon close examination two types of "clinical resistance" were discernible: the failure of chemotherapy to produce adequate cytotoxic effects ("classical" drug resistance), and treatment failure attributed to the rapid regrowth of leukemia cells subsequent to the substantial killing of leukemia cells by cytotoxic therapy ("biological" resistance). Each form of resistance accounted for one-half of the treatment failures.     

The community competence scale as a measure of functional daily living skills

Competence assessment is of growing interest to administrators and clinicians who work with deinstitutionalized psychiatric and geriatric populations. A new instrument, the Community Competence Scale (CCS), is a multiscale structured interview administered in a similar manner to the Wechsler Intelligence Scales. The CCS requires the subject to answer questions and perform tasks which are proximal corollaries of daily living skills. The psychometric properties of the CCS are reviewed. Results of studies involving administration of the CCS to deinstitutionalized psychiatri patients and geriatric patients are presented. The available data suggest that the CCS has considerable value as a preplacement screening instrument for determination of residential settings for chronic psychiatric patients. Since the original CCS requires between 60 and 90 minutes for administration, several recent studies have focused upon development of a short form. The results of this research effort are described. In sum, the CCS appears to demonstrate considerable value as a tool to aid decision making about community placement, social skills training and clinical competence determinations.     

Lack of a bimodal distribution of ventricular size in schizophrenia: a Gaussian mixture analysis of 1056 cases and controls.

The finding of clinical and laboratory differences between schizophrenic patients with large and small cerebral ventricles has led to the widespread assumption that large ventricles are a marker that characterizes a subgroup of patients with schizophrenia. We reviewed all published English language ventricle-to-brain ratio (VBR) studies in which individual data points were available (schizophrenics: n = 691, medical controls; n = 205, normal volunteers: n = 160). Using a univariate normal mixture model to examine the distribution of ventricular size in each group, we found no evidence of a mixture of Gaussian distributions (i.e., "bimodality") within any of the three groups. The same analysis was then performed on the combined sample of schizophrenic patients and normal and medical controls, respectively. In each case the improvement in fit of a mixture of normal distributions compared to a single component normal distribution was significant. The data do not support the notion that ventricular enlargement is a discontinuous marker of a subtype of schizophrenia.     

Length of time between hospital admission and ventricular fibrillation or cardiac arrest complicating acute myocardial infarction: effect on prognosis

We performed a community-wide study in metropolitan Baltimore to examine the prognostic role of length of time between hospital admission and ventricular fibrillation or cardiac arrest (VFib/CA) complicating acute myocardial infarction (MI). Risk of developing VFib/CA was particularly marked in the first few hours after admission to the hospital. We compared 128 patients experiencing VFib/CA within 48 hours of admission and 80 patients developing these complications after more than 48 hours. Patients with "early" VFib/CA exhibited a lower in-hospital case-fatality rate than those with "late" VBib/CA (67% versus 88%; p less than .01). Likewise, of patients discharged alive from the hospital and followed for as long as six years a greater proportion of the 38 with histories of "early" VFib/CA survived than of the 11 who had experienced "late" VFib/CA during hospital admission (.05 less than p less than .10). These results suggest that whereas "early" VFib/CA may reflect transitory myocardial electrical instability, "late" VFib/CA may indicate chronic instability and thus imply a poor prognosis.     

The effect of bacterially produced vitamin B12 analogues (cobamides) on the in vitro absorption of cyanocabalamin.

An incubation system containing rat jejunoileum was used to determine whether analogues of cyanocabalamin (CNCbl) inhibited the in vitro absorption of CNCbl. The naturally occurring analogues "pseudo B12," "factor A," and the nonnaturally occurring analogue desdemethyl B12, were produced by guided biosynthesis with Propionibacterium arabinosum. Factor B was produced by acid cleavage of cyanocabalamin. Inhibition of Co57-CNBbl uptake was demonstrated for cold CNCbl and for desdemethyl B12, although statistical significance was achieved only for cold CNCbl at 40X and 100X the molar quantity of the radiolabeled CNCbl. However, a trend towards progressive inhibition of specific CNCbl binding was shown as increasing concentrations of CNCbl or desdemethyl B12 were used. No inhibition of specific CNCbl binding could be demonstrated for any of the naturally occurring cobamides tested.     

An incentive program for an HMO-oriented group practice

An employee incentive program in this HMO not only improved the quality of services offered and maintained them at a more cost-efficient level, but also benefitted employees through added income.     

Occupational lead exposure and renin release

Hypertension may result from chronic lead exposure. Lead poisoning arising from "moonshine whiskey" drinking has been associated with a rise in plasma renin activity. In the present study, plasma renin concentration following intravenous administration of frusemide was measured in eleven subjects with moderate or severe lead poisoning of industrial origin. The results were compared with those obtained for seven normal, control subjects. There was no significant difference in response obtained in the two groups. Industrial lead poisoning does not appear to affect renin release. The combined insult of lead and alcohol may explain the findings in the previous study.