Biomedical subjects
Publications and source records attributed to N Bell.
Congress is currently considering the American Medical Association and the American Hospital Association's proposed provider-sponsored organizations, which would possibly compete with MCOs. There are many reasons these plans have rapidly proceeded to the forefront of health plan innovation.
To assess cross-work-site variation in the general drinking behaviors (on and off the job) of employees, we conducted a cross-sectional survey of managers (n = 7255) at 114 places of work located throughout the continental United States. The work-site mean for the total number of drinks consumed on a typical drinking day ranged from 1.4 to 3.17, a two-fold differential. Regression analysis showed an independent work-site effect, controlling for respondents demographics and type of work. This finding suggests that modifiable work-site characteristics could influence what employees drink on and off the job.
We report the clinical and electrophysiologic data on five subjects from two families with severe sensory and autonomic neuropathy who also exhibited peroneal muscular atrophy with the electrophysiologic features of an axonopathy, congenital cataracts, mental retardation, and skin lesions. One patient had hearing loss. Autosomal recessive inheritance was probable in both families.
The movement toward an electronic patient record parallels our efforts to increase the efficiency and the effectiveness of our health care delivery system. In the final article in our continuing series on the computerized, patient-based medical record, the author explains the evolutionary time line toward reaching this goal.
Managed health care is poised for tremendous growth, particularly with the states' plans to increase Medicaid enrollment and the federal government's initiatives to jump-start Medicare enrollment. That means that employment opportunities should become widely available as managed care starts a new period of growth. What job opportunities are out there? What do they pay? What credentials are needed to take advantage of these openings?
BACKGROUND: It is unknown how often prostate carcinomas are diagnosed as a result of urinary obstructive symptoms or whether prostate carcinomas diagnosed because of obstructive symptoms have a favorable or unfavorable prognosis. It is also unknown whether racial differences in obstructive symptoms could help explain why black men with prostate carcinoma are diagnosed with more advanced stages and grades of prostate carcinoma than are white men with prostate carcinoma. METHOD: At a single Veterans Administration Medical Center, 478 consecutive cases of prostate carcinoma diagnosed between 1973 and 1985 were identified. The incidence of obstructive symptoms at diagnosis, racial differences in obstructive symptoms, and the survival of patients with and without obstructive symptoms, stratified by stage and grade, were determined. In addition, racial differences in the frequency of surgical intervention required to relieve the obstructive symptoms were determined. RESULTS: All patients diagnosed with Stage A prostate carcinoma and most (82%) patients diagnosed with Stage C prostate carcinoma had obstructive symptoms. Those diagnosed with Stage B and Stage D prostate carcinomas had with similar frequencies (53% and 55%, respectively) of obstructive symptoms. Survival, stratified by stage and grade, was similar for men with and without obstructive symptoms. The incidences of obstructive symptoms and the frequency of surgical intervention to relieve the obstructive symptoms, stage for stage, were similar for white and black men. CONCLUSION: Survival, stratified by stage and grade, is not affected adversely by obstructive symptoms. Neither racial differences in the incidence of obstructive symptoms nor the frequency with which obstructive symptoms require surgical correction explain why black men with CAP consistently are diagnosed more frequently with Stage D prostate carcinoma and less frequently with Stage A CAP than white men with CAP.
Between 1972 and 1986, 134 patients with stage A carcinoma of the prostate (CAP) were diagnosed at a single Veterans Administration medical centre and followed annually by the hospital tumour registry. Seventy-four were classified as stage A1, defined as non-palpable, well-differentiated CAP, regardless of amount, found unexpectedly on transurethral resection of the prostate (TURP). Twenty-eight were classified as stage A2, defined as non-palpable, moderately or poorly differentiated CAP, regardless of amount, found unexpectedly on TURP. The remaining 32 were reclassified as atypical hyperplasia/adenosis (AH/A) rather than CAP. The survival of each group was compared with the survival of a control group from the same medical centre who had TURPs showing histologically proven benign prostatic hyperplasia (BPH). Survival and tumour progression were similar for patients with stage A1 CAP, AH/A and BPH. Furthermore, patients with stage A1 CAP, with or without therapy, had similar survivals as patients with BPH in each age group (under 65, 65-74 and over 74 years). Stage A2 CAP was associated with a significantly worse survival and more tumour progression. Within stage A1 CAP and stage A2 CAP the percentage of chips with CAP or the amount of CAP removed did not affect survival.
With the trend towards integrated health delivery systems gaining momentum, more health plans and joint ventures are considering capitation as the payment method of choice to physicians, specialty contractors, and other suppliers of health care services. This first article of a two-part series examines the basis for the capitation movement.
In primary medical care settings, disease prevention services are delivered at lower rates than recommended. Furthermore, practitioners tend to overestimate the rate at which they perform them. There are essentially two steps in delivering evidence-based preventive services: (1) knowing what the evidence is for performing various detection and intervention manoeuvres, and (2) integrating the preventive services into daily practice. The first is a scientific process and is carried out in Canada by the Canadian Task Force on the Periodic Health Examination. However, after a decade of experience with evidence-based guidelines, we now know that guidelines are not enough. Integrating clinical prevention into busy practices is a political and logistical process. This truth is best captured by the quip, "An ounce of prevention requires a pound of office system change". A number of studies have demonstrated that continuing medical education (CME) courses and workshops for physicians are not enough to ensure that clinical preventive services are incorporated into practice. According to Lomas, the traditional CME educational approaches need to be complemented by strategies from such paradigms as the social influence model, the diffusion of innovation model and the adult learning model. Battista, in "From Science to Practice," points out the complexity of the communication process required for the diffusion of innovation into practice. Walsh's Systems Model of Clinical Preventive care best captures the interacting factors that mediate between practitioners' intentions and their actions when it comes to delivering clinical prevention services. This paper reports on a practical example of helping family practitioners develop a "sustaining office system in prevention" that minimizes barriers, focuses energy and integrates clinical prevention into office routines. The key components are (i) a practice coordinator for prevention, (ii) clear clinical prevention-related job descriptions for all persons who deal with patients, (iii) an information management system that reinforces prevention, and (iv) a practice feedback and problem solving strategy.
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To determine if exercise intolerance and fatigue in chronic heart failure could be exacerbated by an abnormal metabolic response to exercise, we studied 12 patients with stable chronic heart failure and 12 normal volunteers during symptom-limited maximal treadmill exercise. Peak VO2 was 17.2 (15.1-19.2) ml.kg-1 x min-1 in patients and 29.9 (26.3-33.5) in controls (mean and 95% confidence intervals; P < 0.0001, t-test). Overall, levels in peripheral venous blood of glucose, glycerol and free fatty acids were greater in patients, although the differences became less marked with increasing exercise intensity. Noradrenaline was elevated in patients at rest, but the peak exercise response was similar to controls. Responses of adrenaline, insulin and glucagon were similar in both groups. We conclude that depletion of the levels of circulating substrates is not contributory to exercise intolerance and fatigue in chronic heart failure. Greater levels of glycerol and free fatty acids may be mediated by excess sympathetic nervous system activity, reflected in elevated noradrenaline levels.
In order to determine whether treatment of hyperlipidaemia with simvastatin impairs exercise stress responses and so may contribute to an excess of suicides and violent deaths, the effects of simvastatin 20 mg daily and placebo on exercise physiology were compared in 19 patients. After 6 weeks of treatment there was no evidence of reduced exercise capacity, or of reduced cortisol or catecholamine responses. It is concluded that treatment of hyperlipidaemia with an inhibitor of HMG-CoA reductase does not significantly modify stress responses, and so the explanation for a possible increase in non-cardiac mortality must be sought elsewhere.
During normal progressive exercise, the gas exchange anaerobic threshold occurs when CO2 production (VCO2) and ventilation (VE) increase so as to depart from a linear relationship to O2 consumption (VO2). This is thought to represent a gas exchange response to metabolic acidosis due to lactate accumulation. Patients with McArdle's disease have previously been reported to exhibit a steepened ventilatory response relative to VCO2, despite an inability to produce lactate. However, the VCO2 response has not been studied. We therefore investigated the VCO2-VO2 and VE-VO2 relationships in seven McArdle's disease patients and seven control subjects during symptom-limited maximal treadmill exercise. Analysis of gas exchange showed that whereas all control subjects had an easily identifiable anaerobic threshold, four of the patients had none and the other three displayed an attenuated threshold. The occurrence of the threshold in one patient was associated with a small rise in lactate and in another patient with an abrupt rise in leg discomfort, suggesting a pain response. Ammonia and the purine metabolite hypoxanthine were elevated during exercise in all patients, suggesting that ammonia may be a product of adenosine monophosphate degradation. Free fatty acid levels were also elevated, and a shift toward utilization of lipid may contribute to abnormal gas exchange responses. It is concluded that lactic acidosis contributes to the gas exchange anaerobic threshold but that other factors, such as discomfort, may be involved in the excess Ve seen during heavy exercise.
Pentoxifylline (PTX) has potential usefulness in HIV-seropositive patients due to its beneficial effects on renal function, its inhibitory effects on tumor necrosis factor alpha, and its vascular effects on microcirculatory disturbances. The present study prospectively evaluated the effects of multiple oral doses of PTX (400 mg three times daily for 12 weeks) on renal function in 11 HIV-seropositive patients compared with 14 control patients. Four of these patients had HIV-associated nephropathy, manifested by high urinary microalbumin outputs (72 +/- 56 micrograms/min; mean +/- SD). Ambulatory 24-h urine collections were analyzed for creatinine, electrolytes, and immunological markers at weekly intervals for 12 weeks. Urine flow rates diminished to one-half baseline values by week 12; changes were related to both time and treatment sequences. There were significant decreases in creatinine clearances and electrolyte excretion rates over the study period that were not associated with treatment regimens. No differences were found in fractional electrolyte, uric acid, microalbumin, and neopterin excretion rates either between or within groups. One subject with high microalbumin excretion rates had a significant drop over the 12 weeks (133 to 4 micrograms/min); the other 3 subjects had similar or elevated microalbumin outputs by the end of the study. Although well tolerated, therapeutic doses of PTX did not significantly affect renal function in HIV-seropositive patients.
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Tumor necrosis factor-alpha (TNF alpha), a potential regulator of HIV-1 replication, is involved in the progression of AIDS and associated disorders such as muscle wasting, fever and gastrointestinal problems. HIV-seropositive patients were assigned to receive zidovudine (ZDV; 100 mg 4-5 times/d) alone (n = 14), pentoxifylline (PTX; 400 mg every 8 h), a drug known to block TNF alpha release (n = 7), or PTX and ZDV (n = 11) for 12 weeks in a prospective, open-label study. Weekly compliance checks and biweekly blood and 24-h urine samples were obtained for immunological assessments. Baseline TNF alpha levels were elevated in all study patients, independent of disease stage. There were no appreciable differences in immunologic variables (CD4 counts, total and unbound p24 antigen, TNF alpha, beta 2-microglobulin, and urinary neopterin levels) between groups. The mean HIV-1 viral load, as measured by a quantitative polymerase chain reaction technique, was 1.9-fold above baseline values after 12 weeks of ZDV and PTX compared with 8- to 9-fold greater levels in patients given either agent alone (p < 0.05). TNF alpha levels correlated with viral load (r = 0.67; p < 0.0001) in patients given the combined drug regimen. Virological evidence of lack of progression in AIDS patients suggests the beneficial use of ZDV and PTX in delaying progressive HIV-1 disease compared with each drug alone.
A relatively new addition to the growing list of managed care options, POS plans contain some of the cost control elements of HMOs. Yet they also allow enrollees some of the freedom of choice associated with PPOs.
The object of the present investigations was delineation of the exclusive effects of cyclophosphamide (Cytoxan) on host humoral response to tumor, as evaluated by the level of circulating antigen/antibody complexes (AACs), which may reflect the chemo-responsiveness of hosts and provide a rationale for new therapeutic strategies. Our data, recorded in Copenhagen X Fischer rats bearing Dunning's R-3327 Mat Ly-Lu adenocarcinoma of the prostate, show no modulatory effect of cyclophosphamide at 10 mg/kg, a nonspecific immunosuppressive effect at 30 mg/kg, and a definite immunostimulatory effect on host humoral immunity at 100 mg/kg. Sequential determination of AAC levels at different stages of tumor growth, i.e. from the primary to the metastatic stage, performed with the original purpose of demonstrating that any disturbance in the immunoregulatory mechanism of the host was due to cyclophosphamide rather than to changes in tumor load, revealed that levels of AACs parallel disease progression in the initial stages of primary tumor growth but rapidly decrease to near-normal levels in the presence of heavy tumor burden.