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Biomedical subjects

B Cooper

Publications and source records attributed to B Cooper.

232 records · Page 13Linked to original sources

Prescription drug coverage, utilization, and spending among Medicare beneficiaries.

Outpatient prescription drugs are not a covered benefit under Medicare. There have been proposals in the past to expand Medicare benefits to include drug coverage, and current discussions dealing with "modernizing" the Medicare benefit package have raised the issue again. Using data from the 1995 Medicare Current Beneficiary Survey (MCBS), we describe the sources and extent of drug coverage among Medicare beneficiaries. The data show that 65 percent of Medicare beneficiaries have some level of drug coverage--a figure much higher than previous published numbers--and that 95 percent of Medicare health maintenance organization (HMO) enrollees have drug coverage. The data provide a baseline to observe future changes in the level of coverage, particularly among Medicare managed care plans.

Aged↗

Endosulfan transport: I. Integrative assessment of airborne and waterborne pathways.

To reduce endosulfan (C9H6O3Cl6S; 6,7,8,9,10,10-hexachloro-1,5, 5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide) contamination in rivers and waterways, it is important to know the relative significances of airborne transport pathways (including spray drift, vapor transport, and dust transport) and waterborne transport pathways (including overland and stream runoff). This work uses an integrated modeling approach to assess the absolute and relative contributions of these pathways to riverine endosulfan concentrations. The modeling framework involves two parts: a set of simple models for each transport pathway, and a model for the physical and chemical processes acting on endosulfan in river water. An averaging process is used to calculate the effects of transport pathways at the regional scale. The results show that spray drift, vapor transport, and runoff are all significant pathways. Dust transport is found to be insignificant. Spray drift and vapor transport both contribute low-level but nearly continuous inputs to the riverine endosulfan load during spraying season in a large cotton (Gossypium hirsutum L.)-growing area, whereas runoff provides occasional but higher inputs. These findings are supported by broad agreement between model predictions and observed typical riverine endosulfan concentrations in two rivers.

Agriculture↗

Effect of vascular occlusion on tumour temperatures during superficial hyperthermia.

Tumour temperature heterogeneity during hyperthermia has been attributed to irregular tumour vascular perfusion. We have compared temperature distributions in human tumours subjected to superficial hyperthermia under conditions of normal and occluded blood flow. Three patients with recurrent malignant melanoma on the leg were treated with radiation followed by hyperthermia 60-90 min later on days 1, 8 and 22. Heating (15-30 min) with normal blood flow was followed by 15 min of heating with tourniquet occlusion, although the tourniquet had to be intermittently released when the patients complained of discomfort. Hyperthermia was delivered using either a 1.4 MHz ultrasound or 915 MHz microwave applicator. Temperatures were monitored using superficial and interstitial thermometers in tumour and normal tissues. When the tourniquet was applied, the amount of power required to maintain peak temperatures was decreased by a factor of 3-10. With normal blood flow, there was a significant degree of temperature heterogeneity within the treatment volume, both within normal and tumour tissues, which improved with tourniquet application. The T90 and T50 indices increased both in normal tissues and tumour following the tourniquet occlusion, with the temperature increments being greater for normal tissues. Temperatures at depth were increased despite the reduction in applied power and the temperature profiles were smoother when the tourniquet was applied. No cutaneous, vascular or neuromuscular side effects were observed amongst these three subjects either acutely or at 1 month follow-up. These studies demonstrate directly that the temperature heterogeneity which exists in human tumours subjected to external heating can be reduced by occluding the blood supply.

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A variable microwave array attenuator for use with single-element waveguide applicators.

The effectiveness of hyperthermia treatments is often limited by temperature inhomogeneity that arises in the treatment field due to variable tissue properties and blood flow. Moreover, blood flow can change during a treatment, leading to the formation of hot and cool areas even if the initial temperature distribution is uniform. A variable microwave array attenuator has been constructed, that will enable the field patterns of single element microwave waveguide hyperthermia applicators to be altered during treatment, to improve temperature homogeneity. The coupling bolus was designed with an array of individually controlled elements, each filled with a microwave absorbing saline solution. Additions or withdrawals of saline are made to alter the power deposition in a specific area of the treatment field. Thermographic measurements were made in muscle equivalent phantom materials, with the bolus/waveguide assembly. Results showed that the variable array attenuator was able to significantly alter the heating pattern of a large waveguide applicator.

Biophysical Phenomena↗

The potential role of HSP70 as an indicator of response to radiation and hyperthermia treatments for recurrent breast cancer.

Twenty-three patients with recurrent breast cancer participating in a Phase III trial evaluating radiotherapy (XRT) with or without hyperthermia (HT) were included in a parallel study of heat shock protein (hsp) expression. The patients had core biopsies and/or fine needle aspirates (FNA) performed on their tumours, before and after treatment. These were analysed for hsp content using immunohistochemical staining with a monoclonal antibody to the inducible form of hsp 70. The proportion of samples containing identifiable cancer cells was greater for the core biopsy specimens (80%) than with FNA (60%). Staining intensity was analysed using either the majority score, i.e. the staining intensity (on a relative scale from 0 to 3) for the largest proportion of tumour cells, or the arithmetic score, which is the sum of the product of percentage of tumour cells and their staining intensity. The staining intensity for hsp's after treatment correlated inversely with the probability of attaining a complete response (CR). Specifically, the median and maximum scores for the biopsy specimens were significantly inversely related to the probability of attaining CR. The results suggest that this technique may be useful in predicting for thermotolerance development, though more data is needed to confirm the utility of the technique. Results from this study corroborate data from other clinical studies which suggest that tumours with elevated hsp levels may demonstrate resistant biologic behaviour.

Biopsy↗

Self-medication in ophthalmology.

Patients on a short-stay ophthalmology ward are encouraged to administer their own medication. In this article, the author describes how standards were set to audit the self-medication programme.

Eye Diseases↗

No sleep until September.

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Attitude of Health Personnel↗

Epidemiology and clinical psychiatry.

The applications of clinical and statistical epidemiology to the study of mental disorders are reviewed. A closer cooperation in this field between epidemiologists and clinicians, and a more active participation of psychiatrists in community-based research, are advocated and some practical steps towards this end are suggested.

Disease Outbreaks↗

[Psychiatric disease and social isolation in elderly nursing home residents: a comparative study].

As part of a population-based morbidity survey, a sample of over-65-year-old residents of geriatric nursing homes and old people's homes (N = 153) in the city of Mannheim, F.R.G. (Popn. 308,000) was investigated with regard to mental and physical impairment, as well as to the frequency and quality of their family and social contacts. Corresponding data from the investigation of a community sample (N = 350) served as a basis for a direct comparison of old people in residential care and those living in the community. The findings point to a large relative excess both of mental impairments--especially organic brain syndromes--and of physical disabilities among the nursing-home residents. Those in old people's homes, in marked contrast, do not differ in these respects from persons of the same age living in the community. The home residents have on average far fewer social contacts, and derive less help and support from their social relationships, than do their contemporaries who live in private households. From this point of view, there appears to be little difference between those in nursing homes and those in old people's homes. The observed disparities between the home and community samples remained significant following statistical correction of the data for differences in the sample distributions by age and by marital status. The implications of these findings for further research and for geriatric service-planning are discussed.

Aged↗

Combined aztreonam and gentamicin therapy for pseudomonal lower respiratory tract infections.

A multicenter, open-label study was performed to assess the efficacy and safety of aztreonam plus gentamicin in the treatment of lower respiratory tract infections due to Pseudomonas aeruginosa. Patients with documented P aeruginosa infections were given aztreonam 2 g every 8 hours (q8h) plus gentamicin 3 to 5 mg/kg per day in three equal doses. Clindamycin, 600 mg q8h, was added to the regimen for patients with infections also involving gram-positive and/or anaerobic bacteria. Therapy was continued for at least 5 days or until obvious failure to respond to treatment. Of 64 patients with suspected P aeruginosa infections, 57 were eligible for clinical evaluation and 51 for microbiologic evaluation. At entry, impaired host defense was present in 35% of patients, and chronic obstructive pulmonary disease in 28%, in addition to other predisposing conditions such as emphysema, history of tuberculosis, and pneumothorax. The clinical response rate for the combination regimen was 48/57 (84%), which included 27 (47%) cures and 21 (37%) partial responses. The microbiologic response rate was 35/51 (69%), of which 25 (49%) outcomes were classified as eradication and 10 (20%) as eradication with relapse. Superinfection was observed in 3 (6%) patients. The combination of aztreonam and gentamicin was synergistic in the initial isolates obtained from 33 (72%) patients. A total of 16 patients died of pulmonary or other underlying disease, for a mortality rate of 28%. The monobactam-aminoglycoside combination was generally well tolerated. Two other patients were withdrawn because rashes emerged on treatment. This study demonstrates that aztreonam can be administered as one component of a synergistic monobactam-aminoglycoside therapy in the treatment of nosocomial lower respiratory tract infections involving P aeruginosa.

Adult↗