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Biomedical subjects

W Weller

Publications and source records attributed to W Weller.

At least 19 recordsLinked to original sources
PubMed2001

Specialty of principal care physician and Medicare expenditures in patients with coronary artery disease: impact of comorbidity and severity.

OBJECTIVE: To explore differences in expenditures for elderly patients with acute and chronic coronary artery disease according to the specialty of the principal care physician. STUDY DESIGN: Retrospective analysis of Medicare claims. PATIENTS AND METHODS: A total of 250,514 patients with coronary artery disease (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 410-414) were drawn from a national random sample of 1992 Medicare expenditures. Patients were classified by the physician type with the highest number of Medicare Part B outpatient claims into a cardiologist group and a generalist group. The outcome was mean total expenditures, stratifying (1) by comorbidity as measured by the modified Charlson Index and (2) by severity defined as the proportion of patients with acute myocardial infarction or unstable angina. RESULTS: Those patients in the cardiologist group had lower comorbidity and higher severity than those in the generalist group. Overall mean expenditures were significantly higher for the cardiologist group than for the generalist group ($7658 vs $6047; P < .001). These differences in mean expenditures were evident at each level of comorbidity. However, when stratified by severity of diagnosis, differences were seen predominantly in those with acute diagnoses. For those with either acute myocardial infarction or unstable angina, the mean expenditures were higher for the cardiologist group than for the combined generalist group ($15,378 vs $12,260; P < .001); however, the mean expenditures for those with only chronic conditions were similar ($4856 vs $4745; P = .53). CONCLUSION: Expenditures were higher when cardiologists were the principal care physicians treating patients with acute disease but not chronic disease.

Acute Disease↗
PubMed1998

Capitation for cardiologists: accepting risk for coronary artery disease under managed care.

Patients with chronic disease may be excluded from capitated managed care plans due to higher than average expected costs. In an attempt to remedy this inequity, one type of risk adjustment technique proposes to set separate capitation rates for certain chronic illnesses, including coronary artery disease (CAD). Cardiologists, who increasingly are requested to accept capitation, will benefit from understanding the impact of using clinical factors as opposed to using demographic factors to set capitation rates. Using a 5% national random sample of the 1992 Medicare population, we determined mean annual expenditures and variation in expenditures of individuals with CAD. We compared the use of 2 demographic factors currently used for capitation rate adjustment (age and gender) with 2 factors not currently used--3-digit International Classification of Disease (ICD-9) code (a measure for severity) and Charlson index (a measure for comorbidity). Mean annual expenditures for individuals with CAD were more than double mean annual expenditures for the general Medicare population ($6,944 vs $3,247). Among individuals with CAD, mean expenditures of subgroups defined by both age and gender ranged from $6,205 to $7,724. In comparison, stratifying by measures of severity and comorbidity identified subgroups with lower and higher mean expenditures, producing a range of $1,702 to $19,959. Substantial variation of expenditures for individuals within subgroups defined by severity and comorbidity remained, with few patients having substantially higher expenditures than the rest. When capitation rates are set with the use of demographic factors alone, patients may be subjected to risk selection and physicians to financial loss. Using clinical measures may decrease the incentive for patient risk selection, but substantial financial risk to physicians would remain, because of a relatively few patients with high expenditures (or costs).

Aged↗
PubMed1994

Association of polyomavirus middle tumor antigen with 14-3-3 proteins.

To carry out its transformation function, the middle tumor antigen (MT) of murine polyomavirus associates with a number of cellular proteins involved in regulation of cell proliferation, including pp60c-Src, phosphatidylinositol 3-kinase, protein phosphatase 2A, Src homologous and collagen protein and growth factor receptor-binding protein 2. Here, two additional MT-associated proteins were identified as members of the 14-3-3 family of proteins. Yeast homologs of 14-3-3 proteins have recently been shown to play a role in the timing of mitosis. Thus, regulation of 14-3-3 protein function by MT may contribute to the development of neoplasia.

14-3-3 Proteins↗
PubMed1992

The third subunit of protein phosphatase 2A (PP2A), a 55-kilodalton protein which is apparently substituted for by T antigens in complexes with the 36- and 63-kilodalton PP2A subunits, bears little resemblance to T antigens.

The small and middle T (tumor) antigens of polyomavirus have been shown previously to associate with the 36-kDa catalytic subunit and the 63-kDa regulatory subunit of protein phosphatase type 2A, apparently substituting for a normal third 55-kDa regulatory subunit (D.C. Pallas, L.K. Shahrik, B.L. Martin, S. Jaspers, T.B. Miller, D.L. Brautigan, and T.M. Roberts, Cell 60:167-176, 1990). To facilitate a comparison of the normal regulatory subunit and T antigens, we isolated a 2.14-kb cDNA clone encoding this 55-kDa subunit from a rat liver library. Using a probe from the coding region of this gene, we detected a major 2.4-kb mRNA transcript in liver and muscle RNAs. The 55-kDa protein phosphatase 2A subunit purified from rat skeletal muscle generates multiple species when analyzed on two-dimensional gels. Transcription and translation of the clone in vitro produced a full-length protein that comigrated precisely on two-dimensional gels with three of these species, indicating that the 55-kDa protein is apparently modified similarly in vivo and in reticulocyte lysates. Additional species in the purified preparation were not found in the translate, suggesting that there are probably two or more isoforms of this protein in rat muscle. Somewhat surprisingly, there was no clear homology with T-antigen amino acid sequences.

Amino Acid Sequence↗
PubMed1987

Asbestos induced fibrosis in the omentum of rats. Immunofluorescence microscopical demonstration of collagens types I and III; laminin and fibronectin.

Fibrosis and neoplasia are evoked by asbestos fibres. Different experimental models have been used to elucidate the cellular mechanism of their pathogenesis but there is no report available dealing with the role of structural glycoproteins and collagens in the development of the fibrosis. The omentums of 20 female SPF-Sprague-Dawley rats were investigated 1, 2 and 6 months after intraperitoneal injection of 15 mg UICC reference samples of crocidolite, by light- and immunofluorescence microscopy. Using monospecific antibodies, laminin, collagens types I and III and fibronectin were localized. After 6 months typical asbestos bodies were detected. By indirect marking of the basal lamina with anti-laminin-antibodies the marked degree of vessel proliferation occurring during the development of granuloma became visible. The deposition of connective tissue which was already established after 4 weeks was mainly due to collagen type III. After 4 and 8 weeks an accumulation of fibronectin associated with larger asbestos fibres was observed. The results suggest that fibrogenesis is promoted by the opsonic activity of fibronectin for long asbestos fibres. The fibrosis may derive from activated resident fibroblasts.

Animals↗
PubMed1985

A Cryptococcus neoformans strain from the brain of a wildlife fox (Vulpes vulpes) suspected of rabies: mycological observations and comments.

A Cryptococcus neoformans strain which in 1983 caused an infection of the central nervous system (CNS) in a wildlife fox with rabies-like symptoms was tested for its strain-specific brown colour effect (BCE) on Guizotia abyssinica creatinine agar and for its ability to assimilate creatinine. Both reactions were found to be positive. These results were found to be largely identical with those of 2 out of 3 strains having caused fatal cryptococcosis in 1970, 1979 and 1983 in persons living in the area where the fox had been found (radius 40-100 km). Some theoretical aspects of the epidemiology and pathogenesis of cryptococcosis in the wildlife fox and rodents are discussed. For further epidemiological investigations into the prevalence of Cr. neoformans in man and animals in this area, the two reactions for detecting and typing, i.e. the BCE on Guizotia abyssinica creatinine agar and the creatinine assimilation are proposed.

Animals↗
PubMed1979

The role of upper airways and of sensoric receptors on reflex bronchoconstriction.

The influence of bilateral transection of the nervi laryngici cranialis, laryngici caudalis and glossopharyngici on ACH and allergen-induced bronchoconstriction was tested in 15 dogs. In three dogs the free preparation of bilateral nervi laryngici cranialis was performed for control measurements. Partial transection of pulmonary left nervus vagus was performed in three dogs and compared to radical transection of the same nerve in three animals. Transection of the nervi laryngici cranialis as well as of the nervi glossopharyngici was followed by the inhibition of the allergen-induced bronchoconstriction. The bronchoconstriction following ACH challenge was not influenced by transection. Bronchoconstriction induced by allergen returned to the same values within three weeks after surgical intervention. Partial unilateral dissection of the vagus nerve on lung hilus shows a small decrease in bronchial constriction induced by allergen and by ACH. Complete unilateral dissection of the vagus nerve on the lung hilus reduced the bronchial constrictoric response to both substances significantly.

Acetylcholine↗
PubMed1977

Respiratory damage caused by long-term inhalation of high concentration of sulphur-dioxide in dogs.

It has been tried in this study to produce chronic obstructive bronchitis in dogs by exposing them to high concentrations of SO2. The study was extended to 175 days and during that period the animals were exposed to 300-500 ppm SO2 for a total of 435 h. None of the three dogs developed serious respiratory damage. Most of the symptoms were transitory. Histological examinations showed increased number of goblet cells in trachea, main- and lobar bronchi and a slight alteration of the bronchial glands.

Acetylcholine↗
PubMed1975

[Registration and evaluation of blood pressure curves of the pulmonary artery with reference to various causes of error].

In about 250 experiments with male and female anesthetized mongrel dogs, measurements of right ventricle and pulmonary artery pressure were carried out. We used Goodale-Lubin-, micro- and Swan-Ganz-catheters. The pressure registration was done by usual equipment. The investigation was performed to evaluate the reason and the extent of disturbances, which affect the real and formal pressure curve in the arteria pulmonalis. The following results could be obtained: 1. The disturbances can lead to fluctuations of such extent, that a correct demarcation of normal and pathological values is impossible. 2. Of great influence on the results of measurements are preparation and registration (warm-up-time, amplification, closeness of pressure-system, unhurt catheters), factors relating to equipment and methods (air-bubbles in pressure-system, damping by filters, continuous infusion of the micro-catheter, level of zero-pressure), factors which occur during intravital measurement (pressure-drop along the arteria pulmonalis, influence of normal breathing, great intrapleural pressure changes, pressure damping in the catheter by thrombosis and external disturbances) and last not least positive and negative acceleration forces, which influence the diastolic and systolic pulmonary artery pressure. 3. Most of the defects and disturbances also occur, when the physical conditions of the equipment are correct. When the preparation and registration is conducted very carefully, all disturbances can be recognized, eliminated and corrected during the registration. 4. The main problems are caused by influence of normal and pathological intrapleural breathing pressures. By reasons of comparison it is necessary to select the pressure values to be used from a great number of real and formal correct pressure values. Besides it is necessary to have always in mind the transmural pressure in the evaluation of pulmonary artery pressures. 5. By consideration of these results it is possible to mark off the normal pressure zone of pulmonary artery pressure from the low pathological zone.

Animals↗
PubMed1975

Long-term test on rhesus monkeys for the PVNO therapy of anthracosilicosis.

In order to test the therapeutic efficiency of intravenous PVNO injections against anthracosilicotic changes, long-term inhalation tests were performed in which rhesus monkeys were exposed to coal-quartz dust. The exposures were given over a period of 48 months. PVNO treatment at a concentration of 300 or 600 mg/kg body weight began 8 months after the end of exposure. To determine the effect of PVNO injections, hydroxyproline examinations of the urine were made. After a total duration of 70 months the test was followed by an examination of respiration and circulation. In addition to histological check-ups the organ weights were determined. Under the influence of PVNO treatment neither a regression of anthracosilicotic changes in lungs and lung lymph nodes occurred nor was the progression of these changes retarded.

Animals↗