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Biomedical subjects

B A Morris

Publications and source records attributed to B A Morris.

At least 37 records · Page 2Linked to original sources
PubMed1995

Health care professionals' accuracy in predicting patients' preferred code status.

BACKGROUND: In spite of the emphasis on physician and patient communication in the new guidelines for the use of do-not-resuscitate orders published by the American Medical Association, informal information indicates that physicians and other health care professionals often formulate code status decisions without formal knowledge of the patient's wishes. The purpose of this study was to determine how accurately health care professionals are able to predict a patient's desired code status given a profile of the patient's medical history. METHODS: A consecutive sample of physicians and other health care professionals attending on-site primary care and long-term rehabilitation staff meetings were asked to participate in the study. Subjects read profiles of actual patients and attempted to predict the patients' desired code status. Subjects also highlighted factors of the patient profile that they deemed important in predicting each patient's desired code status. RESULTS: For the 12 patient profiles examined, the respondents accurately estimated patients' desired code status an average of only 6.5 times. Patient ability to perform the basic activities of daily living was the patient profile factor cited most frequently as influential in determining code status. CONCLUSIONS: Given only clinical and demographic data, health care professionals are only slightly better than chance in determining patients' desired code status. Health care professionals working with long-term care patients should become familiar with individual patient's values and desires for code status decisions.

Activities of Daily Living↗
PubMed1994

Use of enoxaparin, a low-molecular-weight heparin, and unfractionated heparin for the prevention of deep venous thrombosis after elective hip replacement. A clinical trial comparing efficacy and safety. Enoxaparin Clinical Trial Group.

A randomized, parallel-group, open-label clinical trial (the physicians, patients, and staff were not blinded with regard to the regimen that had been used) was conducted, between December 1988 and September 1990, to compare the safety and efficacy of enoxaparin, a low-molecular-weight heparin, with the safety and efficacy of unfractionated heparin for the prevention of deep venous thrombosis after elective hip replacement. Six hundred and ten patients were randomized, and 607 patients received one of the study medications. The evaluations of efficacy included contrast-media venography, non-invasive vascular examination, and clinical examination. Data on efficacy were available for 604 patients, who had been assigned to one of three treatment groups: thirty milligrams of enoxaparin every twelve hours (194 patients), forty milligrams of enoxaparin once daily (203 patients), or 5000 units of unfractionated heparin every eight hours (207 patients). All drugs were administered subcutaneously. Dosages were not adjusted on the basis of the results of coagulation tests or the body weight of the patient. Treatment was initiated within twenty-four hours after the operation and continued for a maximum of seven days. The primary safety outcome was the occurrence of bleeding episodes. An intent-to-treat patient analysis revealed that deep venous thrombosis occurred in nine (5 per cent) of the 194 patients who received thirty milligrams of enoxaparin every twelve hours, thirty (15 per cent) of the 203 patients who received forty milligrams of enoxaparin once daily, and twenty-four (12 per cent) of the 207 patients who received unfractionated heparin. The rate of deep venous thrombosis was significantly lower in the group that received thirty milligrams of enoxaparin every twelve hours than in the group that received unfractionated heparin (p = 0.03) and in the group that received forty milligrams of enoxaparin once daily (p = 0.0002). No clinically symptomatic pulmonary embolism was observed during the treatment or follow-up phase of this study in the group that received thirty milligrams of enoxaparin every twelve hours. Analysis of evaluable patients revealed a marked reduction in the rate of deep venous thrombosis in the group that received thirty milligrams of enoxaparin every twelve hours (eight [6 per cent] of 136 patients) compared with the group that received heparin (twenty-one [15 per cent] of 145 patients) (p = 0.10); however, this difference was not significant because of the small number of patients included in this analysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1994

Family practice residents' attitudes toward their academic projects.

BACKGROUND AND OBJECTIVES: As research has become an increasingly important activity in family medicine, so the teaching of research skills has become an important part of family practice residents' training. The purpose of the study was to determine the attitudes toward research and related topics of a family practice program's graduates who had participated in a required academic project during their residency training. METHODS: A questionnaire using Dillman methodology was mailed to graduates of the University of Toronto family practice program. Graduating years surveyed were 1987-1992. RESULTS: There were 321 (78%) responses from the 427 graduates. Most projects completed during residency had been literature reviews. Ninety percent of respondents felt that critical appraisal skills were important to them as practicing physicians, but only 39% felt they had been sufficiently educated about these skills. Other research-related skills (writing, presenting, data analysis) were learned more thoroughly. The majority (58%) felt neutral or negative about their projects, and 79% would not have done a project if it had been optional. CONCLUSIONS: This cohort of family practice graduates felt negatively about the teaching of research skills during residency. Providing more support and developing a curriculum may improve resident satisfaction.

Adult↗
PubMed1994

Increasing bicycle helmet use in the community. Measuring response to a wide-scale, 2-year effort.

OBJECTIVE: To determine whether a wide-scale, long-term community promotional effort would increase the use of bicycle helmets among children. DESIGN: Over 2 years, a non-profit group coordinated a range of activities to promote helmet use. On one date before the intervention began and three dates during the intervention, observers surveyed students riding bicycles. SETTING: Cyclists were observed at 5 elementary schools, three secondary schools, and two community college entrances. PARTICIPANTS: A total of 851 cyclists were observed, 536 of them at elementary schools in a convenience sample. INTERVENTIONS: Print, radio, and television advertising; posters; pamphlets; bicycle rodeos; and a play were used in a public awareness campaign. Health promotion activities included education, social marketing, community development, and legislative action. MAIN OUTCOME MEASURES: Number of cyclists and whether they wore helmets. RESULTS: Combining the two observation dates for each year, helmet use increased from 5.4% in 1990 to 15.4% in 1991. The greatest increase was observed among elementary school students, the group most at risk of serious head injury or death. Overall, girls were twice as likely to wear helmets as boys. CONCLUSIONS: Wide-scale, long-term community promotion appears to be effective in increasing the use of bicycle helmets.

Age Factors↗
PubMed1993

The activity of the coat protein promoter of chloris striate mosaic virus is enhanced by its own and C1-C2 gene products.

DNA fragments from the bidirectional promoter region of the geminivirus chloris striate mosaic virus (CSMV) were cloned into the pUC18-based vector, pG1 producing transcriptional fusions with the beta-glucuronidase (GUS) gene and nopaline synthase terminator sequence. The relative activity of each promoter construct was analyzed by a GUS expression assay of extracts from Zea mays (maize) Black Mexican Sweet protoplasts coelectroporated with the GUS reporter constructs and constructs in which individual CSMV open reading frames (ORFs) were placed under control of a cauliflower mosaic virus 35 S promoter. Weak promoter activity was observed for the promoter of the C1 and C2 ORFs (C1-C2 gene) and for the promoter of the V1 ORF. The activity of these promoters was unaffected by coelectroporation with the CSMV ORF constructs. Moderate activity was observed for the promoter of the V2 ORF (coat protein gene) which was enhanced by coelectroporation of the C1-C2 ORF construct. Sequences within the C1-C2 gene responsible for transactivation of the V2 ORF promoter were mapped close to the A site of a conserved NTP-binding sequence pattern within the C2 ORF. To a lesser extent activity for the promoter of the V2 ORF was enhanced by the V2 ORF construct providing evidence for positive autoregulation of the CSMV coat protein gene.

Base Sequence↗
PubMed1993

Prenatal screening for hepatitis B surface antigen. Is universal screening necessary?

Prenatal screening for hepatitis B is now recommended as a universal practice in Canada. This study questions whether that policy should apply outside large urban centres. We studied women delivering babies at the Royal Victoria Hospital in Barrie, Ont. Of 1216 women, results of HBsAg screening were available for 716; only two women, both from a high-risk group, were HBsAg positive. If selective screening is used, physicians must question patients carefully to ensure that women at risk are identified and tested.

Carrier State↗
PubMed1992

The nucleotide sequence of the infectious cloned DNA component of tobacco yellow dwarf virus reveals features of geminiviruses infecting monocotyledonous plants.

An infectious clone of the Australian geminivirus tobacco yellow dwarf virus (TobYDV) was constructed from virus-specific double-stranded DNA isolated from infected tobacco and used to demonstrate a single-component genome. The nucleotide sequence of TobYDV DNA comprises 2580 nucleotides. TobYDV DNA has three coding regions, two in the virion sense and one in the complementary sense, homologous to those identified for other geminiviruses, particularly those infecting monocotyledonous (monocot) plants. The complementary sense coding region is comprised of two overlapping reading frames, with an intron of 86 nucleotides. Efficient splicing of the mRNA for this coding region was observed in the infected dicotyledonous (dicot) hosts bean and tobacco despite the intron having an A + U content (57%) more typical of geminiviruses of monocot plants. TobYDV encapsidates a small oligonucleotide able to prime synthesis of the complementary DNA strand in vitro. The TobYDV genome organization, low A + U intron, and encapsidated oligonucleotide primer resemble those of the monocot-infecting geminiviruses. These results strongly suggest that TobYDV is a monocot geminivirus which has become adapted to dicot hosts.

Base Sequence↗
PubMed1992

Nucleotide sequences and expression of cDNAs for a bovine anti-testosterone monoclonal IgG1 antibody.

cDNAs coding for the heavy and light chains of a bovine anti-testosterone IgG1 monoclonal antibody have been cloned and sequenced. These cDNAs are the first to be reported for functionally rearranged bovine immunoglobulin genes. Testosterone binding by the antibody encoded by the cDNAs has been verified by expression of the cDNAs in COS-1 cells and detection of anti-testosterone antibodies in transfected cell media using an ELISA specific for bovine anti-testosterone IgG. The derived protein sequence of the variable domains have suggested a possible binding model for the interaction between the antibody and testosterone. The derived protein sequence of the constant domains has been used to identify residues which could be involved in the selective transport of bovine IgG1 from blood plasma into colostrum at the time of parturition.

Amino Acid Sequence↗
PubMed1992

Molecular modelling and site-directed mutagenesis on a bovine anti-testosterone monoclonal antibody.

A three-dimensional (3D) molecular model of the antigen-combining site of a bovine anti-testosterone monoclonal antibody has been constructed. In the model, the CDRs, and a single heavy chain framework region residue (Trp47), associate to form a hydrophobic cavity large enough to accommodate a single molecule of testosterone. Tyr97 of CDR-H3 lies at the bottom of the cavity with its hydroxyl group exposed to solvent. Using the model and data from binding studies, we predicted that the cavity forms the antibody's paratope and on binding testosterone a hydrogen bond is formed between Tyr97 of CDR-H3 and the hydroxyl group on the D-ring of testosterone. This prediction has subsequently been tested by site-directed mutagenesis. An antibody with phenylalanine in place of tyrosine at position 97 in CDR-H3 has its affinity reduced by approximately 800 fold. The reduction in binding energy associated with the reduced affinity has been calculated to be 3.9 kcal/mol which is within the range (0.5-4.0 kcal/mol) expected for the loss of a single hydrogen bond. The model has been used to suggest ways of increasing the antibody's affinity for testosterone.

Amino Acid Sequence↗
PubMed1992

The influence of continuous passive motion on the results of total knee arthroplasty.

Twenty-two primary total knee arthroplasties were prospectively randomized into one of two treatment protocols. Ten of these patients were managed in the hospital after surgery by means of a postoperative splint. The remaining 12 patients were placed immediately postoperatively in the recovery room into the continuous passive motion (CPM) device. The study compares the range of motion, analgesic use, hospital stay, and the volume of hemovac output in the two groups. These cases demonstrated two statistically significant findings with the use of CPM: (1) decreased use of narcotic analgesics and (2) decreased length of hospital stay.

Aged↗
PubMed1992

Community and university--partners in research.

Community-based and university-based family practice researchers must come together and merge into a synergistic partnership. Community-based researchers often need the special expertise of university statisticians, epidemiologists, and research methodologists, and the enthusiasm of fellow researchers. University-based researchers look to the community for subjects and the all-important factor of generalizability. We must no longer rely on serendipity to bring community- and university-based researchers together. Community-based people must acknowledge their needs and actively seek out assistance. The university-based departments can respond by deliberately starting outreach programs, setting up buddy systems, engaging community research consultants, and tracking residents and urging them to continue to do research. Sentinel networks can increase the depth of involvement community researchers have with their own, and others', projects. Such efforts will lead to a creative interrelationship that will be rewarding and enjoyable for us all.

Family Practice↗