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Biomedical subjects

D Baker

Publications and source records attributed to D Baker.

At least 307 records · Page 17Linked to original sources
PubMed1988

Case management and quality assurance to improve care of inner-city children with asthma.

Case management and quality assurance techniques were used in a program designed to improve the process and outcomes of care for inner-city children with asthma. The program had three major elements: assessment of the care of individual patients and feedback to their primary care providers, periodic contact with parents, and provision of educational materials about asthma to parents. Telephone interviews with parents were used to assess knowledge of home asthma care and the type of care prescribed by the child's physician. Medicaid and hospital records were used to measure acute care utilization. Eighty-eight children (aged 0 to 5 years) who had made more than two emergency room visits for asthma were recruited by telephone. Fifty-six prescribing errors were identified, 24 being failure to prescribe an additional drug for short-term use by children receiving continuous therapy. Acute care use dropped 50% compared with a control period. This type of program is feasible but may require in-person recruiting to reach high-risk families without telephones.

Asthma↗
PubMed1988

Trichobezoar.

Explore the source record for details and available documents.

Bezoars↗
PubMed1988

Androgens inhibit basal and estrogen-induced cell proliferation in the ZR-75-1 human breast cancer cell line.

This study describes the inhibitory effect of 5 alpha-dihydrotestosterone (5 alpha-DHT) and its precursors testosterone (T) and androst-4-ene-3,17-dione (delta 4-DIONE) on the growth of the estrogen-sensitive human breast cancer cell line ZR-75-1. In the absence of estrogens, cell proliferation measured after a 12-day incubation period was 50-60% inhibited by maximal concentrations of 5 alpha-DHT, T, or delta 4-DIONE with half-maximal effects (IC50 values) observed at 0.10, 0.15 and 15 nM, respectively. This growth inhibition by androgens was due to an increase in generation time and a lowering of the saturation density of cell cultures. The antiestrogen LY156758 (300 nM) induced 25-30% inhibition of basal cell growth, its effect being additive to that of 5 alpha-DHT. The mitogenic effect of 1 nM estradiol (E2) was completely inhibited by increasing concentrations of 5 alpha-DHT with a potency (IC50 = 0.10 nM) similar to that measured when the androgen was used alone. E2 had a more rapid effect on cell proliferation than 5 alpha-DHT, the latter requiring at least 5 to 6 days to exert significant growth inhibition. As found in the absence of estrogens, maximal inhibition of cell proliferation in the presence of E2 was achieved by the combination of the antiestrogen and 5 alpha-DHT. Supraphysiological concentrations of E2 (up to 1 microM) were needed to completely reverse the growth inhibitory effect of a submaximal concentration of 5 alpha-DHT (1 nM). The antiproliferative effect of androgens was competitively reversed by the antiandrogen hydroxyflutamide, thus indicating an androgen receptor-mediated mechanism. The present data suggest the potential benefits of an androgen-antiestrogen combination therapy in the endocrine management of breast cancer.

Androgen Antagonists↗
PubMed1988

Protein transport to the vacuole and receptor-mediated endocytosis by clathrin heavy chain-deficient yeast.

Clathrin heavy chain-deficient mutants (chcl) of Saccharomyces cerevisiae are viable but exhibit compromised growth rates. To investigate the role of clathrin in intercompartmental protein transport, two pathways have been monitored in chcl cells: transport of newly synthesized vacuolar proteins to the vacuole and receptor-mediated uptake of mating pheromone. Newly synthesized precursors of the vacuolar protease carboxypeptidase Y (CPY) were converted to mature CPY with similar kinetics in mutant and wild-type cells. chcl cells did not aberrantly secrete CPY and immunolocalization techniques revealed most of the CPY in chcl cells within morphologically identifiable vacuolar structures. Receptor-mediated internalization of the mating pheromone alpha-factor occurred in chcl cells at 36-50% wild-type levels. The mutant cells were fully competent to respond to pheromone-induced cell-cycle arrest. These results argue that in yeast, clathrin may not play an essential role either in vacuolar protein sorting and delivery or in receptor-mediated endocytosis of alpha-factor. Alternative mechanisms ordinarily may execute these pathways, or be activated in clathrin-deficient cells.

Animals↗
PubMed1988

Phenotypic analysis of guinea pig Langerhans cells with antibodies directed against leucocyte surface antigens.

The epidermis was stained with a panel of recently produced anti-guinea pig leucocyte antibodies. Guinea pig Langerhans cells were not detectable with antibodies directed against B lymphocytes (MSgp9), T lymphocytes (CT7 and MSgp7), T-helper/inducer (MSgp12) and putative T-suppressor/cytotoxic (CT6 and MSgp6) subsets. Langerhans cell expressed both major histocompatibility complex (MHC) class-I and II antigens and also an epitope (CT4) associated with lymphocyte migration, thus suggesting the migratory potential of this cell. Although the Langerhans cell did not express macrophage specific antigens, MSgp5, which detects lymphoid dendritic cells, was weakly expressed on the Langerhans cell. The Langerhans cell expressed a leucocyte-common antigen detected by H201. Double-labelling studies with anti-MHC class-II antibodies indicated that only 0.4 +/- 0.3% of the pan leucocyte-positive epidermal cells were Ia-negative, indicating that it is unlikely that a guinea pig analogue of the murine Thy-1 + dendritic epidermal cell (Thy-1 + dEC) exists.

Animals↗
PubMed1988

Histochemical identification of guinea-pig macrophages by monoclonal antibody MR-1.

A monoclonal antibody is described which reacts with monocytes and macrophages of the guinea-pig. The antibody recognizes a cytoplasmic component in the majority of tissue macrophages, as detected by histochemical analysis. It reacts positively with all macrophages in lymphoid organs, including Tingible body macrophages. In addition it recognizes the cells of Von Kupffer in the liver, and macrophages in bone marrow and peritoneal cavity. In comparison to other monoclonal antibodies that have been described in the guinea-pig, MR-1 shows a unique tissue distribution. The antibody is a useful tool to discriminate macrophages by immunohistochemical methods.

Animals↗
PubMed1988

Workplace smoking policies: attitudes of union members in a high-risk industry.

We surveyed members of a medium-size national union representing workers in high-risk industries to assess workers' support for union and company programs to help smokers break the habit and policies that restrict smoking. Two surveys were conducted that involved 690 respondents in 1984 and 593 respondents in 1985. Respondents overwhelmingly (82%) favored restrictions on smoking in the workplace but less than half agreed that companies or unions should be concerned about workers smoking off the job. For both smokers and nonsmokers, beliefs that cancer has specific causes and can be prevented strongly predict support for workplace smoking control policies. Exposure to company occupational health training also influenced smokers and nonsmokers to support selected smoking control policies. These and other findings led to the conclusion that: (1) educating workers about cancer may promote support for smoking control policies, and (2) smoking control policies are more acceptable in the context of a strong company health and safety program.

Attitude↗
PubMed1987

Interval gangrene occurring after successful lower-extremity revascularization.

Four patients experienced a rare but devastating complication of peripheral vascular reconstructive surgery in which gangrene occurred in the presence of a functioning graft and palpable pulse. Three patients underwent bypass procedure for limb-threatening ischemia. Despite a "satisfactory" postoperative result of a well-perfused distal extremity and strongly palpable pulse, each of these patients developed progressive ischemic gangrene in an area proximal to the distal anastomosis and eventually required amputation. These patients demonstrate the importance for maintaining collaterals to perfuse bypassed segments of the lower extremities. In a patient with inadequate collateral circulation or in whom the profunda perigeniculate collateral pathway has been disrupted or is absent due to disease, it is necessary to revascularize sequential vascular beds.

Aged↗
PubMed1987

Identification and quantitation of the expression of T cell surface markers during the development of chronic relapsing experimental allergic encephalomyelitis (CREAE) in the guinea pig.

As there were discrepancies in previous data on the T cell nature of cells infiltrating the meninges at all stages of chronic relapsing experimental allergic encephalomyelitis (CREAE), experiments have been performed using a further monoclonal antibody (Mab) recognizing total T cell populations and the classic E rosetting technique. Cytospins were prepared of the meningeal inflammatory cells obtained by washing the brains of these animals, and stained by indirect immunoperoxidase. It was found that the T cell, as defined by both E rosetting and staining with the Mab CT5, is the major cell type found in the meninges during the development of CREAE. However, the staining with the Mab CT7, which recognizes a functionally relevant antigen, showed that there is a discrepancy between the numbers of lymphocytes stained compared to the results with CT5 and E rosettes. Furthermore, the antigen recognized by CT7 appeared to be modulated during the disease. The possible functional relevance and its relation to clinical remission and relapse are discussed.

Animals↗
PubMed1987

Changes in lymphocyte subsets after treatment with cyclophosphamide and during the development of contact sensitivity in the guinea pig.

Changes in lymphocyte subpopulations were investigated in guinea pig lymph nodes during the development of contact sensitivity to 2,4-dinitrofluorobenzene (DNFB) and following the injection of cyclophosphamide (CY; 300 mg/kg) using a panel of monoclonal antibodies against guinea pig lymphocyte surface markers. Application of a sensitizing dose of DNFB to the ear resulted in a significant increase in the number of cells recovered from the draining auricular and cervical lymph nodes, 4 and 6 days post sensitization. A significant increase in the number of cells in the contralateral cervical node was found at day 6 but not at day 4. At 4 days postsensitization the proportions of Ia positive lymphocytes were higher than those of immunoglobulin positive B cells in the draining auricular and cervical node and the contralateral cervical lymph nodes suggesting T-cell "activation". Four and six days after sensitization there were no significant changes in the proportions of Pan T and T suppressor/cytotoxic (Ts/c) positive lymphocytes in the draining auricular and cervical lymph nodes. Although contact sensitivity is "classically" a T-cell mediated phenomenon there was a significant increase in the proportion of B cells found in the draining auricular node 4 days after sensitization as compared to the "normal" auricular node. 1, 2, 3 and 7 days after injection of CY there was a significant depletion in the proportion of B-lymphocytes in the cervical lymph node. This effect was maximal between 2 and 3 days after CY and was paralleled by an increase in the proportion of Pan T positive cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Efficacy of surgical treatment for paralytic ectropion.

Paralytic ectropion can be corrected with numerous procedures. Advocates of particular procedures have previously been unable to quote statistical rates of success for each procedure over significant lengths of time. This study reviews over 200 cases of paralytic ectropion, representing the spectrum of seventh nerve disease seen at an eye and ear specialty hospital and a general medical facility. Of all eyelid implantation devices 93 to 95% failed to work or needed reoperation by 3 years postoperatively. Soft tissue surgery without prosthetic implants or exoplants provided 60% success after a 3-year follow-up. Eyelid elevation or tightening coupled with surgery for facial reanimation produced a higher rate of success at 3 years (83%). An overwhelming number of patients (62%) complained of some degree of epiphora after any or all procedures. Based on these findings, soft tissue surgery without prosthetic implants or exoplants has a higher rate of success.

Ectropion↗
PubMed1987

Experience with tarsal suspension as a factor in lower lid blepharoplasty.

The bowed lower eyelid, with scleral show, is a common but untoward result following blepharoplasty with even minimal skin excision. A number of conditions, unrecognized preoperatively, can predispose a patient to scleral show. These include eyelid laxity with or without atrophic orbicularis muscle tone, lax canthal tendons, hypoplastic malar eminences, unrecognized Graves' ophthalmopathy, unilateral high myopia, or the secondary blepharoplasty. Suspension of the tarsus of the lower eyelid, concomitant with or following blepharoplasty, can straighten bowed lids and provide 2 to 3 mm of elevation, if desired. A classification of patients likely to develop scleral show is presented along with a revised technique of tarsal suspension.

Adolescent↗
PubMed1987

An antigenic determinant common to lymphocytes and Langerhans cells of the guinea pig.

A mouse anti-guinea pig monoclonal antibody, designated MSgp 2, was derived by the fusion of NS-1 myeloma cells with mouse splenocytes hyperimmunized with guinea pig B cells. MSgp 2 reacts with an antigen present on the majority of lymphocytes. An unexpected finding was the expression of the MSgp 2 antigen on epidermal Langerhans cells, as defined by cell morphology, expression of MHC class II antigen and presence of Birbeck granules in positive cells. It is suggested that the tissue distribution of MSgp 2 antigen on lymphocytes of the lymph node could indicate a role for this determinant in cell migration.

Animals↗
PubMed1987

An evaluation of intravenous infusion pumps and controllers.

The accuracy, safety, reliability and cost of use of 35 intravenous infusion pumps and 3 flow controllers were assessed. When infusing saline 11 out of 17 syringe pumps, 3 out of 5 peristaltic pumps, 1 out of 2 roller pumps and all 14 cassette pumps tested were accurate to within 5% over their full ranges of operation. There was no significant change in the performance of any of the pumps tested when saline was infused through a standard resistance, except in the cases of the 3 flow controllers which were unable to infuse at all against the resistance. When 50% dextrose was infused, delivery by two peristaltic pumps was reduced by 23 and 38%. No pump cut out or alarmed at pressures of up to 200 mmHg and 21 pumps continued to infuse against pressures of 750 mmHg or greater. Surges of up to 0.5 ml occurred after release of an outlet obstruction. One device was fitted with a variable high pressure alarm. This device could also measure pressure in the infused vessel and was found to be accurate for measurements of central venous pressure. The cost of consumables for a single use for syringe pumps ranges from A$2 to $5, for peristaltic and roller pumps from A$1 to $10, and for cassette pumps from A$7 to $12, with an additional A$2 for a burette. Accurate delivery of intravenous fluids and drugs is available but is expensive and requires the operator to be specially trained. No simple, cheap, accurate device is yet available.

Evaluation Studies as Topic↗