Search PubMed⌕ Search

Biomedical subjects

R O'Brien

Publications and source records attributed to R O'Brien.

136 records · Page 8Linked to original sources
PubMedDate not supplied

Peptide sequences of T-cell receptor delta and gamma chains are identical to predicted X and gamma proteins.

Although most mature peripheral T lymphocytes express a major histocompatibility complex restricted, CD3-associated, antigen receptor (TCR) which has been well characterized, some T cells carry a different CD3-associated heterodimer on their surface. One of the two disulphide-linked chains of this putative second receptor, which in mice has relative molecular mass (Mr) 35,000 (35K), has been identified as a product of the group of gamma genes. The other chain, termed delta (Mr 45K in mice), is not as well characterized. Although gamma/delta-bearing cells are a minor subset among peripheral T lymphocytes, they are the only CD3+ cells in the thymus early in ontogeny. Taking advantage of these kinetics, we have generated gamma/delta-bearing hybridomas, using a new TCR alpha chain-negative variant of the AKR thymoma BW5147 as tumour parent, fetal thymocytes as normal cell partners, and an anti-CD3 monoclonal antibody (mAb) as screening reagent. Gamma and delta chains from one of these hybrids have been purified and partially sequenced. The sequences obtained indicate that delta is indeed identical to the polypeptide encoded by the recently described gene X, as suggested by Chien et al.

Amino Acid Sequence↗
PubMedDate not supplied

Proton MR spectroscopy of experimental radiation-induced white matter injury.

We studied the spectroscopic appearance of radiation-induced myelinolysis in cats to understand the characteristics of proton MR spectroscopy of demyelinating disorders. Eight cats received 5,000 rads to a 1.5 x 1.5 cm area of the right cerebral hemisphere. Eight to 9 months after irradiation, a gross area of abnormal postcontrast enhancement and/or high MR signal intensity was detected in the irradiated hemisphere of six of the eight cats. Proton spectra of a 1.0 cm3 voxel in the affected region demonstrated depressed N-acetyl aspartate/creatine-phosphocreatine and N-acetyl aspartate/choline-containing compound peak ratios compared with the contralateral non-irradiated brain in all cats. Elevated amino acid resonances in the 2.0-2.5 ppm range were not consistently seen in irradiated zones of the brain with pathologic findings of demyelination. In vivo proton MR spectroscopy may show differences between irradiated brain and nonirradiated brain even when histopathologic lesions are not apparent yet.

Amino Acids↗
PubMedDate not supplied

Evaluation of co-morbidity indices in patients admitted for chronic obstructive pulmonary disease.

BACKGROUND: There is limited and conflicting information on the use of co-morbidity instruments to predict mortality in patients with chronic obstructive pulmonary disease (COPD). METHODS: We sought to test the validity of the Charlson Index and another co-morbidity instrument, the Adult co-morbidity evaluation 27 (ACE-27), in patients admitted with COPD exacerbations. Co-morbidity scores were obtained by chart review. Information on mortality was retrieved from the Social Security Death Index. We examined the predictive validity of the Charlson and the ACE-27 using survival analysis. RESULTS: There were 112 patients eligible for the study. The ACE-27 but not the Charlson predicted survival, after adjusting for age, gender, and smoking history in Cox regression, hazard ratio (95% CI) of 1.99 (1.17-3.39). CONCLUSIONS: This study confirms earlier findings that the Charlson Index is not a reliable predictor of mortality in patients with COPD. However, the ACE-27 appears to be useful for predicting survival in this study.

Aged↗
PubMedDate not supplied

Starvation.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMedDate not supplied

Private sector approach to health care reform. Interview by Thomas G. Goodwin.

The Healthcare Leadership Council (HLC) was formed in 1990 by 50 CEOs of hospitals, hospital systems, pharmaceutical companies, medical device manufacturers, Insurers and medical professionals. HLC is a coalition to develop the necessary consensus to realistically influence health care reforms. HLC urges that the "U.S. public policy goal should be to seek the best mechanism for balancing quality, access and affordability." As for access for the poor, the HLC would standardize eligibility for Medicaid at the federal poverty level, establishing a minimum basic benefit and payment plan with funding to come from specific taxes. For the employed uncovered, HLC would extend the exemption from state mandates to small employers; enact appropriate market reforms and provide income-related subsidies for those near the poverty line and for small employers; encourage employer-provided coverage for all employees on a voluntary basis.... HLC also backs state subsidized uninsurable risk pools for people whose conditions would make premiums too expensive. As for affordability of health care, HLC says consumers should become involved in cost-effective health care plans, appropriate employee cost sharing, lifestyle incentives/penalties, etc. Also, legislation should be overridden that inhibits innovation, creativity (state-mandated benefits, restrictions on selective contracting, CON requirements...), and medical malpractice tort reform measures also should be enacted. What follows is an in-depth interview with HLC Chairman G. Robert O'Brien, president of CIGNA Employee Benefits Companies.

Health Care Coalitions↗
PubMedDate not supplied

Spectral characteristics of human leukocytes and their relevance to automated cell identification. III. Eosinophils, neutrophils and lymphocytes.

The spectral characteristics of various normal cell types from human blood were examined in respect to an automated, rapid-flow photometric identification system after staining for peroxidase activity. It was found that a plot of light loss against light scatter gave a separation of eosinophils, neutrophils and lymphocytes comparable in accuracy to visual separations. This staining was not useful for the segregation of monocytes and basophils, for which other stains have proven useful in the sytsem under study. It is concluded that automated, rapid-flow photometric identification of blood cell types can produce differential cell counts with good confidence levels.

Blood Cell Count↗