Icosahedral quasicrystal decoration models. II. Optimization under realistic Al-Mn potentials.
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Journal Article↗
Biomedical subjects
R Phillips
Publications and source records attributed to R Phillips.
The activity of a blood type B specific exoglycosidase from Glycine max.
Soluble antigens, enzyme-linked immunosorbent assays (ELISA), and cell suspension assays were used to study the blood group B activity of Glycine max (soybean) alpha-D-galactosidase. The enzyme readily hydrolyzed the terminal alpha-D-galactosyl of the B antigen under a variety of conditions, converting it to H antigen. Conversion of the B antigen to H antigen produces blood type O which is universally transfusable. These preliminary studies are important in determining optimal conditions for enzymatic conversion of blood type B to O erythrocytes if efficient large-scale production of enzymatically converted, universally transfusable red blood cells is to be achieved.
ABO Blood-Group System↗
The introduction of mentorship to Project 2000 in Wales.
This study focused upon the introduction of mentors in the Common Foundation Programme (CFP) of Project 2000 (UKCC 1986) in Wales. It was commissioned by the Department of Health Research and Development Division on behalf of the Welsh Office Nursing Division. The study was policy oriented and its purpose was to inform future policy decision making through an analysis of the implementation of current policies for pre-registration education. The full title of our research project, 'The practitioner teacher: a study in the introduction of mentors in the pre-registration nurse education programme', implied that a clinically-based nurse practitioner with a designated teaching remit, fulfills a particular role (that of mentor) in the pre-registration nurse education programme. It was the nature, scope and impact of this mentor role during the initial implementation period of the CFP of Project 2000 in Wales to which this study addressed itself.
Curriculum↗
Vasoactive intestinal peptide concentrations in turkey hypophysial portal blood differ across the reproductive cycle.
Hypophysial portal blood was collected for the first time in an avian species using a dorsal approach through the third ventricle and median eminence of the turkey. This was done to test for the presence of the prolactin (PRL)-releasing factor vasoactive intestinal peptide (VIP) in the portal blood and to determine whether VIP concentrations there varied with and corresponded to plasma PRL levels across the reproductive cycle. VIP concentrations in hypophysial portal blood were 2.5- to 13.5-fold greater than in the general circulation. VIP concentrations were lowest in portal blood of nonphotostimulated, reproductively inactive hens (231.8 +/- 26.4 pg/ml) and highest in incubating hens (1108.1 +/- 363.7 pg/ml), while laying, and photorefractory hens were intermediate at 372.5 +/- 95.6 and 715.3 +/- 338.5 pg/ml, respectively. These differences in concentration of VIP in portal blood mirrored those of PRL in the general circulation and support other evidence that VIP is the avian PRL-releasing factor.
Animals↗
The psychological impact on staff of caring for people with serious diseases: the case of HIV infection and oncology.
Psychological stress and work-related burnout in staff working with AIDS and with cancer patients were compared using a self-report method of assessment. Measures included the General Health Questionnaire (GHQ), Maslach Burnout Inventory (MBI), and the Social Adjustment Scale (SAS-M). More than 80% of those staff who were approached responded to the questionnaire, including 70 doctors and nurses working with people with AIDS and 41 doctors and nurses working in oncology. More than a third of staff had substantial levels of psychological morbidity, and about a fifth had significant levels of work-related stress. Factors associated with the presence of high levels of psychological morbidity and with abnormal levels of emotional exhaustion, depersonalization, and concerns about personal accomplishment were identified. Staff described the work situations with which they had difficulty dealing and some of the coping strategies they used. The findings confirm that staff working with people with cancer or AIDS experience psychological difficulties of the kind likely to respond to interventions aimed at improving their ability to cope with work-related stresses. The mental health services could play an important role in carrying out research in this field and in providing practical help to deal with staff's difficulties.
Acquired Immunodeficiency Syndrome↗
A randomized, double-blind, placebo-controlled, controlled antigen delivery study of the onset of action of aerosolized triamcinolone acetonide nasal spray in subjects with ragweed-induced allergic rhinitis.
BACKGROUND: Clinically apparent relief of nasal symptoms of allergic rhinitis is generally recognized to occur within 3 days to 1 week when intranasal corticosteroids are used. OBJECTIVE: A study was designed to evaluate the onset of action of triamcinolone acetonide (TA) in patients with ragweed-induced allergic rhinitis with an environmental exposure unit (EEU). METHODS: Eighty-five adults with ragweed-induced allergic rhinitis were primed with ragweed allergen in the EEU. Symptoms were recorded during a baseline exposure in the EEU, and subjects were randomized with a 5:1 ratio to receive either TA 400 micrograms (n = 71) or its propellant (n = 14). Subjects received study medication for 7 days under supervision in the morning and returned to the EEU in the evening for ragweed allergen challenge and symptom assessment. Clinically apparent onset of action was defined as a 25% decrease in symptom scores from baseline. RESULTS: A mean reduction in nasal congestion from baseline of greater than 25% (onset of action) was observed in the TA group, but not in the placebo group, by 10 hours. This was also observed for itching of the nose or palate and a combined measure of symptoms. In addition, the proportion of subjects with less nasal congestion after 1 day of treatment was greater in the TA group (41%) than in the placebo group (7%) (p less than 0.05). CONCLUSION: The unexpected early relief of symptoms observed in the TA group and, to a lesser extent in the placebo group, has important clinical implications in the treatment of allergic rhinitis.
Administration, Intranasal↗
Fluconazole versus oral polyenes in the prophylaxis of immunocompromised patients: a cost-minimization analysis.
This study compares 100 mg daily fluconazole with oral polyenes four times daily in the prophylaxis of fungal infections in immunocompromised patients, to determine a cost-minimization strategy. Data was gathered through a literature survey and clinical interviews conducted in nine different UK hospitals. This was used to construct a decision tree, modelling the drug choices available to a clinician at various stages of a patient's treatment, and assigning probabilities to the different corresponding outcomes. UK cost data were fed into this model to determine the expected cost per patient of the different prophylaxis strategies. Two different patient groups were considered: chemotherapy-only patients, and bone-marrow-transplant (BMT) patients who have higher risks of fungal infection. Probabilities derived from the literature suggest that a cost-minimization strategy to manage both chemotherapy patients and BMT patients is to administer oral fluconazole, both as prophylaxis and as first line treatment, against superficial fungal infection. Probabilities gathered from clinical interviews yield similar results, suggesting that the cost-minimization strategy with chemotherapy-only patients is to administer oral polyenes as prophylaxis, and oral fluconazole in case of superficial fungal infection, while for BMT patients it is a combination of fluconazole and oral polyenes as prophylaxis, with oral fluconazole for the treatment of superficial fungal infections. Using the probabilities from the literature, the lowest cost strategies produce an expected cost of pounds 567.20 for chemotherapy-only patients, and an expected cost of pounds 804.87 for BMT patients for a course of treatment lasting from seven to 28 days. The clinical interview probabilities produce expected costs of pounds 826.48 and pounds 1529.43, respectively. Sensitivity analysis was then conducted, and it was found that in the majority of cases, using the literature probabilities, the cost-minimizing strategy remained prophylaxis with oral fluconazole. The sensitivity analysis for chemotherapy-only patients using the interview probabilities tended to favour oral polyenes as the cost-minimization strategy, whereas for BMT patients the sensitivity analysis favoured a combination of fluconazole and oral polyenes in the majority of cases. The key economic advantage of prophylaxis with fluconazole or a combination of fluconazole with oral polyenes in the prophylaxis of fungal infection in immunocompromised patients, results from the reduction of the expected cost of subsequent fungal infection among those who are most at risk.
Antifungal Agents↗
Retrospective multicenter analysis of 3i endosseous dental implants placed over a five-year period.
Osseointegrated dental implants have now become an accepted form of treatment for patients with a fully or partially missing dentition. The purpose of this study was to evaluate the performance of 3i threaded and cylindrical implants. During a 5-year period, a total of 1969 3i endosseous implants were placed at 6 centers in the United States and 2 elsewhere in the edentulous and partially edentulous jaws of 653 consecutive patients ranging in age from 18 to 82 years. Of the total number of implants placed, 1341 were commercially pure titanium threaded implants and 628 were titanium plasma-sprayed implants with a cylindrical configuration. A total of 28 patients with 110 implants were lost to follow-up. Implants in these patients were considered neither a success nor a failure. Success was predicated on the osseointegration of each and every implant followed in this analysis rather than the persistence of prosthetic function. Confirmed bone anchorage was considered essential for success. A total of 625 patients with 1871 implants remain in the study with a follow-up period ranging from 6 to 60 months. A total of 93 implants (5.0% of the total implants followed) were considered as failures. A mean implant survival rate was 95.0% for both the threaded and the cylindrical implant was calculated. The success rate of threaded implants was 97.0% in the mandible and 93.8% in the maxilla. The success rate for the 3.3-mm cylindrical implants was 96.0% in the mandible and 95.5% in the maxilla, and the success rate of 4.0-mm-diameter cylindrical implants was 95% in the mandible and 92.0% in the maxilla. Causes of failure consisted of loss of osseointegration (2.3%), crestal bone loss requiring periodontal therapy after the first year of function (1.7%) had mechanical problems associated with the prosthesis (0.9%). This retrospective analysis of the 3i endosseous implant system is comparable to previous reports on other implant systems in terms of implant survival and prosthesis stability. It is demonstrated that 3i implants are predictable and can provide lasting osseointegration leading to improvement of oral function if the recommended surgical and restorative protocol is followed.
Adolescent↗
Identification of a novel HLA-A25-restricted epitope in a conserved region of p24 gag (positions 71-80).
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Amino Acid Sequence↗
Randomized cross-over comparison of liposomal daunorubicin versus observation for early Kaposi's sarcoma.
OBJECTIVES: To evaluate single-agent liposomal daunorubicin chemotherapy in the management of early HIV-related Kaposi's sarcoma (KS). DESIGN: Randomized cross-over comparison of liposomal daunorubicin versus observation. SETTING: Study conducted at single site in tertiary referral HIV unit. PATIENTS: Twenty-nine HIV-seropositive men with < 20 cutaneous KS, no visceral involvement and CD4 cell counts < 400 x 10(6)/I were randomized. Adequate haematological, hepatic and renal function was required for entry. A left ventricular ejection fraction of > 45% was necessary for eligibility. INTERVENTIONS: Patients were randomized to 12 weeks observation or 12 weeks of liposomal daunorubicin 40 mg/m2 every 2 weeks. After 12 weeks, or at disease progression, patients were crossed over to receive the alternative arm. MAIN OUTCOME MEASURES: Disease evaluation was according to AIDS Clinical Trials Group criteria for response assessment and toxicity was recorded using the World Health Organization standardized grading. RESULTS: Response rate to initial liposomal daunorubicin was six out of 15 (40%) and none experienced a spontaneous response during the observation arm. Six patients (40%) randomized to the initial chemotherapy arm progressed during chemotherapy, while 10(72%) in the observation arm progressed. Neutropenia was the main toxicity associated with liposomal daunorubicin and was documented following 20 out of 139(14%) treatment cycles. CONCLUSIONS: Liposomal daunorubicin is a well tolerated and efficacious treatment for early KS; however, the duration of response is brief.
AIDS-Related Opportunistic Infections↗
Outcome measures, pooled index and quality of life instruments in rheumatoid arthritis.
BACKGROUND AND OBJECTIVE: A variety of outcome measures are used in evaluating disease activity and therapeutic efficacy in rheumatoid arthritis (RA) studies, and this makes comparisons of drug efficacy difficult. Some of the endpoints used are not standardized and/or are insensitive to change. The purpose of this report is to present a critical appraisal of outcome measures and quality of life assessments in RA studies. METHOD: An overview of the literature was undertaken to determine the extent to which there is consensus among experts in this area of research. RESULTS: The data suggest that the core set of endpoints in RA clinical studies should include tender joint count swollen joint count, patients' assessment of pain, patients' and physicians' global assessments, patients' assessment of physical function and acute phase reactant level. When trials of disease-modifying antirheumatic drugs (DMARD) last for more than a year, radiography may be useful. A 'pooled index' may be valuable, and its construction is discussed. Quality of life (QoL) instruments facilitate a fuller examination of the effects of health care interventions and these should be used to complement the more traditional clinical endpoints in the core set. The instruments most commonly used in RA research are identified. CONCLUSIONS: We conclude that randomized clinical trials of treatments in RA should now ideally use the core set of clinical endpoints and validated QoL instruments for assessing safety and efficacy.
Arthritis, Rheumatoid↗
Discharge planning: comparison of patients and nurses' perceptions of patients following hospital discharge.
Planning for hospital discharge is an important component of nursing. Results are presented of a study to determine how well primary nurses predict the functional ability of their patients following discharge and to assess whether patients and nurses agree about their patients' understanding of the post-discharge treatment plan. Comparing nurses' predictions with patients' reports of functional status 2 months following discharge, we found that nurses consistently underestimate the functional ability of their patients. Comparing nurses' perceptions of their patients' understanding of their post-discharge treatment plan with patients' reports about their understanding, significant differences were found between nurses' perceptions and patients' reports. Nurses' perceptions were that patients were much more knowledgeable than their patients reported. These preliminary data suggest that hospital discharge planning is an area for further investigation and intervention. Nurses should explore new paradigms for patient education as lengths of hospital stay decrease and care shifts from acute care to community care.
Activities of Daily Living↗
Role of unphosphorylated, newly synthesized I kappa B beta in persistent activation of NF-kappa B.
Stimulation with inducers that cause persistent activation of NF-kappa B results in the degradation of the NF-kappa B inhibitors, I kappa B alpha and I kappa B beta. Despite the rapid resynthesis and accumulation of I kappa B alpha, NF-kappa B remains induced under these conditions. We now report that I kappa B beta is also resynthesized in stimulated cells and appears as an unphosphorylated protein. The unphosphorylated I kappa B beta forms a stable complex with NF-kappa B in the cytosol; however, this binding fails to mask the nuclear localization signal and DNA binding domain on NF-kappa B, and the I kappa B beta-NF-kappa B complex enters the nucleus. It appears therefore that during prolonged stimulation, I kappa B beta functions as a chaperone for NF-kappa B by protecting it from I kappa B alpha and allowing it to be transported to the nucleus.
Animals↗
Participation of nurses in decision making for seriously ill adults.
The purpose of this study is to describe the involvement of nurses in the decision-making process of seriously ill hospitalized adults. Nurses (696) completed interviews with 1,427 patients. Patient, surrogate, and physician interviews were also completed. Patients and surrogates perceive the nurse as more influential in decision making than does the nurse or physician. Many nurses reported having no (31%) or little (36%) knowledge of their patients' preferences, and 53% of the nurses did not advocate for their patients' preferences. Only 50% of the nurses reported educating their patients about the treatment plan chosen or discussing treatment options with their patients, and few (17%) discuss prognosis. This study indicates nurses are not actively involved in the decision-making process of their patients, especially older or more experienced nurses and those working in intensive care units.
Adult↗
Characterization of coffea canephora alpha-D-galactosidase blood group B activity.
Enzymatic conversion of type B to O erythrocytes with Coffea (coffee bean) alpha-D-galactosidase was first described by Harpaz and Flowers and subsequently adopted by others (1,2). An enzyme-linked immunosorbent assay (ELISA) and soluble oligosaccharide substrates were used to study deantigenation of B erythrocytes with the Coffea enzyme. For the ELISA, microtiter wells were coated with B membranes and treated with enzyme under a variety of conditions, probed with primary IgM monoclonal anti-B followed by secondary anti-murine mu-chain specific alkaline phosphatase conjugate, then developed with substrate. This technique has allowed the rapid determination of enzymatic activity over a broad range of conditions; the purpose being to determine parameters for efficiently enhancing enzyme activity. Solid phase activity was then compared to activity against soluble oligosaccharide substrates. We have determined that, under the conditions tested, only moderate increases in enzyme activity against the B epitope can be achieved by modifying reaction conditions with the native Coffea enzyme.
ABO Blood-Group System↗
Code red! Some tips on fighting fire in the ICU.
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Disaster Planning↗
Feasibility evaluation of a new pericardial bioprosthesis with dye mediated photo-oxidized bovine pericardial tissue.
BACKGROUND AND AIMS OF THE STUDY: In an attempt to overcome the problem of calcification of bioprostheses, a novel bovine pericardial tissue valve preserved with a non-aldehyde, dye mediated photo-oxidation process (PhotoFixTM) developed by CarboMedics, Inc. The device was evaluated by implantation in the mitral position of juvenile sheep with a mean age of 3.5 months. MATERIALS AND METHODS: Thirteen valves were evaluated; six experimental valves with photo-oxidized tissue, five identically designed valves with glutaraldehyde-fixed tissue, and two Carpentier-Edwards pericardial valves as controls. RESULTS: Four of the six animals in the photo-oxidized group were free of calcification when electively sacrificed at 152 days, 152 days, one year and 1.5 years respectively. One animal was electively sacrificed at 98 days. Pathologic findings indicated minimal calcification of the valve due to uneven stress distribution from two bent stent posts that most likely occurred during surgical implantation, but the device was still functional. The sixth animal with photo-oxidized tissue died at 131 days due to massive calcification of a single leaflet. There was no pathologic evidence of infection. Explants at five months from additional and still continuing sheep studies per FDA guidelines have not reproduced single leaflet calcification in over forty explanted valves with photo-oxidized tissue. The glutaraldehyde-fixed valves all exhibited some calcification at explant; two of these animals died early due to the mineralization. Both control animals with Carpentier-Edwards valves died early from mitral stenosis due to extensive device calcification. CONCLUSIONS: The fact that four of six valves with photo-oxidized tissue remained free of any signs of calcification for up to 1.5 years, while none of the other valves did, suggests that photo-oxidation is a promising method of preserving and fixing tissue for use in bioprostheses. These results suggest that photo-oxidized bioprosthetic valves may be clinically valuable and warrant further study.
Angiography↗