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Biomedical subjects

M McCall

Publications and source records attributed to M McCall.

At least 19 recordsLinked to original sources
PubMed2001

Statistical process monitoring of WBC-reduced blood components assessed by two types of software.

BACKGROUND: Statistical process control is required for monitoring of the WBC-reduction process. This study focused on some factors that may influence the outcomes of statistical process monitoring, such as WBC-reduction technologies, the anticoagulant used, and WBC-counting technologies, by using two types of software. STUDY DESIGN AND METHODS: Data were collected from January to September 1999, before the implementation of universal WBC reduction. The effects of three major factors were investigated: methods of preparation, the addition of EDTA to the sample, and the WBC-counting technologies used (microvolume fluorimetry, flow cytometry, and Nageotte chamber). The WBC-reduction process capability was assessed by two types of software, EZQC (Gambro BCT) and NWA (Northwest Analytical). In addition, the differences between various sets of results were compared by the t test or ANOVA. RESULTS: There was no statistical difference (at the 0.05 level of significance) in WBC content when the three types of platelets in citrate samples were compared with EDTA samples. In general, the Nageotte chamber appeared to count the lowest, and microvolume fluorimetry appeared to count lower than flow cytometry. There were minor but significant methodologic differences between the software packages. However, these differences had negligible effects on the percentage of conforming components at both <1 x 10(6) and <5 x 10(6) WBCs per unit. CONCLUSION: Only the counting technologies were sufficiently different to warrant consideration. This difference may make unacceptable the interchange of results obtained from various counting methods.

Anticoagulants↗
PubMed2000

The results of a randomized trial of a quality improvement intervention in the care of patients with heart failure. The MISCHF Study Investigators.

PURPOSE: Quality improvement and disease management programs for heart failure have improved quality of care and patient outcomes at large tertiary care hospitals. The purpose of this study was to measure the effects of a regional, multihospital, collaborative quality improvement intervention on care and outcomes in heart failure in community hospitals. PATIENTS AND METHODS: This randomized controlled study included 10 acute care community hospitals in upstate New York. After a baseline period, 5 hospitals were randomly assigned to receive a multifaceted quality improvement intervention (n = 762 patients during the baseline period; n = 840 patients postintervention), while 5 were assigned to a "usual care" control (n = 640 patients during the baseline period; n = 664 patients postintervention). Quality of care was determined using explicit criteria by reviewing the charts of consecutive patients hospitalized with the primary diagnosis of heart failure during the baseline period and again in the postintervention period. Clinical outcomes included hospital length of stay and charges, in-hospital and 6-month mortality, hospital readmission, and quality of life measured after discharge. RESULTS: Patients had similar characteristics in the baseline and postintervention phases in the intervention and control groups. Using hospital-level analyses, the intervention had mixed effects on 5 quality-of-care markers that were not statistically significant. The mean of the average length of stay among hospitals decreased from 8.0 to 6.2 days in the intervention group, with a smaller decline in mean length of stay in the control group (7.7 to 7.0 days). The net effects of the intervention were nonsignificant changes in length of stay of -1.1 days (95% confidence interval [CI]: -2.9 to 0.7 days, P = 0.18) and in hospital charges of -$817 (95% CI: -$2560 to $926, P = 0.31). There were small and nonsignificant effects on mortality, hospital readmission, and quality of life. CONCLUSIONS: The incremental effect of regional collaboration among peer community hospitals toward the goal of quality improvement was small and limited to a slightly, but not significantly, shorter length of stay.

Aged↗
PubMed2000

Antioxidant and prooxidant actions of prenylated and nonprenylated chalcones and flavanones in vitro.

Prenylated flavonoids found in hops and beer, i.e., prenylchalcones and prenylflavanones, were examined for their ability to inhibit in vitro oxidation of human low-density lipoprotein (LDL). The oxidation of LDL was assessed by the formation of conjugated dienes and thiobarbituric acid-reactive substances (TBARS) and the loss of tryptophan fluorescence. At concentrations of 5 and 25 microM, all of the prenylchalcones tested inhibited the oxidation of LDL (50 microg protein/ml) induced by 2 microM copper sulfate. The prenylflavanones showed less antioxidant activity than the prenylchalcones, both at 5 and 25 microM. At 25 microM, the nonprenylated chalcone, chalconaringenin (CN), and the nonprenylated flavanone, naringenin (NG), exerted prooxidant effects on LDL oxidation, based on TBARS formation. Xanthohumol (XN), the major prenylchalcone in hops and beer, showed high antioxidant activity in inhibiting LDL oxidation, higher than alpha-tocopherol and the isoflavone genistein but lower than the flavonol quercetin. When combined, XN and alpha-tocopherol completely inhibited copper-mediated LDL oxidation. These findings suggest that prenylchalcones and prenylflavanones found in hops and beer protect human LDL from oxidation and that prenylation antagonizes the prooxidant effects of the chalcone, CN, and the flavanone, NG.

Antioxidants↗
PubMed1999

Childhood malnutrition and postwar reconstruction in rural El Salvador: a community-based survey.

CONTEXT: The 1992 peace settlement that ended the civil war in El Salvador included land redistribution and other provisions designed to improve the socioeconomic status of ex-combatants and vulnerable civilians. OBJECTIVE: To describe associations between postwar social and economic assistance programs, especially land reform, and current child health status as reflected by nutrition in a population of resettled rural refugees. DESIGN: A population-based cross-sectional survey of child nutritional status and principal elements of the reconstruction process. SETTING: A single rural municipality in northern El Salvador. PARTICIPANTS: A representative sample of 761 children younger than 5 years, living in 27 villages. MAIN OUTCOME MEASURE: Prevalence of stunting (low height for age) in children younger than 5 years. RESULTS: Prevalence of stunting was 32.4%. Stunting was significantly more prevalent among children whose families cultivated less land (odds ratio [OR] for stunting per additional hectare of redistributed land cultivated, 0.64; 95% confidence interval [CI], 0.44-0.93). Less than half of newly transferred land was being cultivated by its owners. Most of the children (84.7%) lived in families cultivating 2 hectares or less of redistributed land. Stunting was also more prevalent among children whose households lacked piped water (adjusted OR, 2.72; 95% CI, 1.87-3.96) vs those who had had piped water since before the cease-fire. CONCLUSIONS: Malnutrition, particularly stunting, persisted at high levels and was strongly associated with delay in full cultivation of redistributed land and in provision of water.

Body Height↗
PubMed1998

Clinical trial and local process evaluation of an apheresis system for preparation of white cell-reduced platelet components.

BACKGROUND: A new method for the consistent preparation of white cell (WBC)-reduced plateletpheresis components, the Spectra Leukoreduction System (LRS), was evaluated by clinical trial and local process validation. The centrifuge-based system was projected to decrease the WBC content of plateletpheresis components to a level below 1 x 10(6) per unit. Phase I and II clinical trials were performed. The manufacturer's claims were then tested at the local level with an ongoing quality assurance program. STUDY DESIGN AND METHODS: In Phase I, a cross-over analysis of five subjects compared LRS to standard plateletpheresis procedures in collection efficiency and component quality: a panel of in vitro measures was taken on Day 0 and Day 5. In Phase II, the LRS process was tested on a larger scale (n = 57; control = 58) with component transfusion. Finally, validation, determination of degree of conformance with standards, and ongoing quality control were performed locally on a newly installed instrument. RESULTS: Phase I and II trials revealed no significant differences between LRS and control units in donor or recipient safety and comfort, platelet function and yield, or component volume. WBC per-unit values were significantly different: the LRS median per unit was 3.2 x 10(4) WBCs, versus 81.4 x 10(4) for control units. Assessment of process capability gave an estimate of 99-percent confidence that 99.5 percent of LRS units would be WBC reduced to < 1 x 10(6) WBCs. Local process validation and quality control revealed 90-percent confidence that 99 percent of the units would be WBC reduced and 99.9-percent confidence that 75 percent would exceed platelet yield standards; the process was stable over time. CONCLUSIONS: The LRS is safe for apheresis and the component produced is safe for transfusion with platelet function and yield equivalent to controls and WBC reduction superior to controls. Local process evaluation confirmed that component quality meets the goals of the institution.

Blood Banks↗
PubMed1998

Health-related physical function and quality of well-being prior to and following cardiomyoplasty. A preliminary report.

OBJECTIVE: The purpose of this study was to obtain preliminary data regarding the effects of cardiomyoplasty on health-related physical function and quality of well-being. EXPERIMENTAL DESIGN: Quasi-experimental with repeated measures. Patients were interviewed prior to surgery, with post-surgical follow-up interviews at 6 weeks, 6 months, and 12 months. SETTING: Interviews were usually conducted by telephone with patients who were at home at the time of data collection. PATIENTS OR PARTICIPANTS: Four patients receiving cardiomyoplasty at Allegheny General Hospital in Pittsburgh, Pennsylvania. INTERVENTIONS: Patients received cardiomyoplasty between November 1992 and April 1993. Cardiomyoplasty using the right latissimus dorsi muscle was performed on the first patient. A left muscle-wrap was performed on the subsequent three patients. MEASURES: Self-reported function and well-being were measured using the Sickness Impact Profile (SIP), the Quality of Well-Being Scale (QWB), and the Medical Outcome Study 36-Item Short-Form Health Survey (SF-36). RESULTS: Patient responses on the SF-36 demonstrated general improvement in cardiomyoplasty survivors. Results on the QWB and SIP are mixed. CONCLUSIONS: Due to the small, incomplete sample and lack of any comparison group, extreme caution must be used in drawing any clinical conclusions from this preliminary data. Future randomized clinical trials of cardiomyoplasty need to include quality of life and health-related physical function as dependent variables. Further psychometric study is necessary which compares the usefulness of these various methods for assessing the value of outcomes for patients with end-stage heart disease.

Aged↗
PubMed1998

Multiple genetic loci modify risk for retinoblastoma in transgenic mice.

PURPOSE: Forty percent of cases of retinoblastoma, a childhood malignancy of the retina, are linked to the inheritance of a mutant allele of the retinoblastoma susceptibility gene Rb1. Tumor penetrance varies among carriers in different family pedigrees, indicating that other genetic factors may modify risk for occurrence of retinoblastoma. This study was undertaken to determine whether multiple genetic loci modify the risk for retinoblastoma in mice. METHODS: A line of alphaAcry-HPV16E6/E7 transgenic mice expressing the human papillomavirus type 16 E6 and E7 oncogenes (HPV-16 E6 and E7) ectopically in the retina was characterized. E6 and E7 proteins bind to and inactivate the cellular tumor suppressor proteins p53 and Rb, respectively. RESULTS: Retinoblastomas developed rarely when the alphaAcry-HPV16E6/E7 transgene was maintained on the FVB background, but tumors arose with high frequency on C57BL/6 X FVB and C3H x FVB F1 hybrid backgrounds. The incidence of retinoblastoma in the LHbeta-TAG transgenic mice, which express simian virus 40 large tumor antigen (SV40 T-ag), was also influenced by the FVB and C57BL/6 backgrounds. Resistance of the alphaAcry-HPV16E6/E7 FVB mice to retinoblastoma mapped in part to the retinal degeneration (rd) locus. However, multiple genetic experiments indicate that resistance to retinoblastoma depends on additional loci in FVB mice. CONCLUSIONS: Multiple cellular genes can modify risk for retinoblastoma in mice.

Animals↗
PubMed1997

The effects of physical attractiveness on gaining access to alcohol: when social policy meets social decision making.

Despite numerous legal interventions, minors continue to purchase and consume alcohol. Prior research had suggested that the decision to request identification to prove legal age was susceptible to various judgement and decision heuristics. This research examined whether the physical attractiveness of the potential consumer and the presence or absence of others were significant predictors of alcohol accessibility. Bartenders (n = 130) rated a target individual who was either high or low in attractiveness. Results indicated that attractiveness was a significant predictor of "proofing likelihood". High levels of attractiveness were associated with a decrease in the likelihood of being asked to provide proof of legal age for the purchase of alcohol. Individuals presented alone were seen as significantly older than when grouped with others. Implications of these findings for the restriction of alcohol availability among minors are considered.

Adult↗
PubMed1996

Unexpected anisotropy in substrate cleavage rates by asymmetric hammerhead ribozymes.

RNA substrates which form relatively short helices I and III with hammerhead ribozymes are generally cleaved more rapidly than substrates which create longer binding helices. We speculated that for optimum cleavage rates, one of the helices needed to be relatively weak. To identify this helix, a series of ribozymes and substrates of varying lengths were made such that in the complex, helices I and III consisted of 5 and 10 bp respectively or vice versa. In two independent systems, substrates in the complexes with the shorter helix I and longer helix III were cleaved one to two orders of magnitude more rapidly than those in the complexes with the longer helix I and shorter helix III. Similar results were obtained whether the numbers of base pairs in helices I and III were limited either by the length of the hybridizing arms of the ribozyme or the length of the substrate. The phenomenon was observed for both all-RNA and DNA armed ribozymes. Thus, a relatively short helix I is required for fast cleavage rates in pre-formed hammer-head ribozyme-substrate complexes. When helix III has 10 bp, the optimum length for helix I is approximately 5 bp.

Animals↗
PubMed1996

Pursuing conception: a physician's experience with in-vitro fertilization.

Infertility is a common problem. Approximately one in seven North American couples will experience it, either by being unable to conceive after a year of trying or by experiencing recurrent miscarriages. A family physician outlines her experiences when being treated for infertility by in-vitro fertilization and embryo transfer.

Autobiographies as Topic↗
PubMed1996

Does QI work? The Management to Improve Survival in Congestive Heart Failure (MISCHF) study.

BACKGROUND: In an ongoing study, a randomized, controlled trial is being conducted on the effects of a collaborative quality improvement program on practice patterns and patient outcomes regarding congestive heart failure (CHF) in community hospitals in upstate New York. CHF is associated with severe morbidity and mortality, with annual rates of death exceeding 50% among patients with the most severe disease. PHASE I: Phase I of the study was designed to model the processes of care and outcomes, develop valid disease-specific risk adjustment techniques, and target areas for quality improvement (QI) intervention. Beginning April 1, 1995, and ending December 31, 1995, baseline data were collected during hospitalization and for six months postdischarge for all 1,402 consecutive patients assigned diagnosis-related groups (DRGs) 127 and 124. Preliminary analyses revealed high rates of hospital readmission (46%) and postdischarge death (18%), with significant interhospital variation. QI INITIATIVES: Initiatives include educational programs on CHF, feedback of Phase I data to clinicians and administrators, design and implementation of a clinical care pathway, improvement of the emergency department (prehospital) phase of CHF management, and improvement in patient education and discharge planning. SUMMARY AND CONCLUSIONS: The study suggests that community hospitals, many without extensive experience in clinical investigation, can voluntarily collaborate to design and implement a timely QI initiative that is evidence based, clinically relevant, and scientifically sound. Preliminary results have led to better understanding of the processes of care and determinants of outcome for patients with heart failure. Phase II of the study should yield insights into the providers' response to a locally derived intervention and the effects of such a program on patient outcomes.

Cardiology Service, Hospital↗
PubMed1996

Increasing perceptions of disease vulnerability through imagery.

Increasing the cognitive availability of disease symptoms can increase perceptions of vulnerability to a fictitious disease. Research findings have also suggested that men and women respond differently to AIDS information; nevertheless, prior research has failed to examine the effects of imagery on both male and female perceptions of vulnerability to a real disease, such as AIDS. Undergraduates were presented with symptoms that were either hard to imagine or easy to imagine (labeled as related to either AIDS or hyposcenia-B) that the students then read or imagined. The results, which replicated prior research, indicated that imagining disease symptoms altered the students' perceived vulnerability to a fictitious disease. However, only imagery was significantly related to perceived vulnerability to AIDS, and gender interacted with this imagery process. Women expressed significant increases in perceived vulnerability when reading the disease symptoms, whereas men were more vulnerable when imagining the disease symptoms than they were when they read about the symptoms. The authors discuss the implications of their research for the integration of theory and experimentation in designing AIDS-intervention programs.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Physical therapist assistants' perceptions of the documented roles of the physical therapist assistant.

BACKGROUND AND PURPOSE: This study investigated physical therapist assistants' (PTAs) perceptions of the documented roles of PTAs and compared those perceptions with those of physical therapists from a previous study. SUBJECTS AND METHODS: A questionnaire that described 79 physical therapy activities was distributed to a sample (n = 400) of PTAs derived from the American Physical Therapy Association membership. The response rate was 56% (n = 225). Respondents indicated whether each activity was included in the documentation describing PTA roles. Discriminant analyses were used to determine whether demographic factors predicted the pattern of responses. In addition, meta-analytic techniques were used to determine whether PTA responses were different from those of physical therapists gathered previously. RESULTS: The greatest agreement of PTA opinions with published guidelines occurred for treatment implementation activities, and the lowest level of agreement occurred for items designated as administrative activities. Responses of PTAs were different from those of physical therapists on 21 of the 79 activities. The greatest number of these differences occurred for evaluative functions (n = 9). Physical therapist assistants' perceptions of documented PTA roles were generally less consistent with published guidelines than were those of physical therapists. CONCLUSION AND DISCUSSION: Physical therapist assistants' perceptions of the roles of the PTA were, for some activities, not consistent with written guidelines. Using the data provided in this study, discussions to revise the documentation of the scope of PTA practice may focus on those activities for which disagreement between PTAs and physical therapists exists and for which opinions differ markedly from published guidelines. [Robinson AJ, DePalma MT, McCall M. Physical therapist assistants' perceptions of the documented roles of the physical therapist assistant.

Allied Health Personnel↗
PubMed1995

A tumor-derived protein which provides T-cell costimulation through accessory cell activation.

A recently described tumor-derived glycoprotein, designated 90K, has been shown to have positive effects on the generation of cytotoxic effector cells (NK/LAK) from human PBMC. To determine the mechanism of these effects, we have examined the effects of 90K on cytokine production by human PBMC. A culture of normal PBMC with 90K alone did not result in IL-2 secretion; however, in coculture with suboptimal doses of ConA, 90K increased IL-2 secretion by PBMC. Coculture of PBMC with 90K and ConA also resulted in increased production of the cytokines IL-1, IL-6, GM-CSF, and TNF alpha. T cells depleted of accessory cells failed to respond to ConA alone, 90K alone, or the combination of ConA and 90K, suggesting that this protein does not have a direct effect on T cells. However, 90K alone was sufficient to induce cytokine production by unfractionated PBMC (IL-1, IL-6, GM-CSF, and TNF alpha) or by CD14-enriched PBMC (IL-1 and IL-6). In addition, expression of ICAM-1 was increased on a human monocytic cell line cultured with purified 90K in the absence of any other stimulus. This 90K-induced upregulation of ICAM-1 expression was accompanied by an increased accessory function of the monocytes, demonstrated by their ability to support ConA-induced activation of peripheral blood T cells. Based on the current data, we propose a model in which 90K activates accessory cells, resulting in the secretion of cytokines and the expression of adhesion molecules, which in turn act as costimulatory signals for T-cell activation. Activated T cells then produce cytokines such as IL-2, which lead to a more vigorous cell-mediated immune response to tumor cells and virus-infected cells. Thus, 90K shows promise as an immunotherapeutic reagent for diseases such as cancer and viral infection.

Antigen-Presenting Cells↗
PubMed1994

Physical therapists' perceptions of the roles of the physical therapist assistant.

BACKGROUND AND PURPOSE: This longitudinal study investigated physical therapists' perceptions of the roles of physical therapist assistants (PTAs). METHODS AND SUBJECTS: In 1986, a questionnaire describing 79 physical therapy activities was distributed to a random sample (n = 400) of physical therapists derived from the American Physical Therapy Association (APTA) membership. In 1992, a similar questionnaire was distributed to a representative sample (n = 400) of physical therapists derived from the APTA membership. Response rates were 53% and 55% in 1986 and 1992, respectively. Respondents indicated whether each activity was included in the documentation describing PTA roles. RESULTS: Results revealed considerable agreement between therapists' perceptions of PTA roles and those outlined by PTA practice guidelines, and these perceptions changed little over time. Discriminant analyses suggested that therapists' perceptions of PTA roles were, in general, not predicted by supervisory experience with PTAs, therapist experience, or content of entry-level professional education curricula. CONCLUSION AND DISCUSSION: Generally, therapists' perceptions of PTA roles are consistent with published practice guidelines. Therapists' perceptions on selected activities, however, were incongruent with PTA practice guidelines, suggesting the potential for inefficient or inappropriate utilization of the PTA in the delivery of selected services.

Allied Health Personnel↗