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Biomedical subjects

M A Stewart

Publications and source records attributed to M A Stewart.

At least 19 recordsLinked to original sources
PubMed1992

Partial dissociation of subgroup C phenotype and in vivo behaviour in feline leukaemia viruses with chimeric envelope genes.

Feline leukaemia viruses (FeLVs) are classified into subgroups A, B and C by their use of different host cell receptors on feline cells, a phenotype which is determined by the viral envelope. FeLV-A is the ubiquitous, highly infectious form of FeLV, and FeLV-C isolates are rare variants which are invariably isolated along with FeLV-A. The FeLV-C isolates share the capacity to induce acute non-regenerative anaemia and the prototype, FeLV-C/Sarma, has strongly age-restricted infectivity for cats. The FeLV-C/Sarma env sequence is closely related to that of common, weakly pathogenic FeLV-A isolates. We now show by construction of chimeric viruses that the receptor specificity of FeLV-A/Glasgow-1 virus can be converted to that of FeLV-C by exchange of a single env variable domain, Vr1, which differs by a three codon deletion and nine adjacent substitutions. Attempts to dissect this region further by directed mutagenesis resulted in disabled proviruses. Sequence analysis of independent natural FeLV-C isolates showed that they have unique Vr1 sequences which are distinct from the conserved FeLV-A pattern. The chimeric viruses which acquired the host range and subgroup properties of FeLV-C retained certain FeLV-A-like properties in that they were non-cytopathogenic in 3201B feline T cells and readily induced viraemia in weanling animals. They also induced a profound anaemia in neonates which had a more prolonged course than that induced by FeLV-C/Sarma and which was macrocytic rather than non-regenerative in nature. Although receptor specificity and a major determinant of pathogenicity segregate with Vr1, it appears that sequences elsewhere in the genome influence infectivity and pathogenicity independently of the subgroup phenotype.

Amino Acid Sequence↗
PubMed1992

A survey method for investigating ethical decision making in family practice.

BACKGROUND: The tension between respect for patient autonomy versus concern for patient welfare is a challenging ethical issue for physicians. The purpose of this research was to describe a method for analyzing ethical decisions and to report the results of a survey of ethical decision making among family physicians. METHODS: We developed a survey instrument that used simulated case scenarios, each of which posed an ethical dilemma. The ethical problems on the survey included the extent to which diagnostic information should be revealed to patients, the extent to which physicians should become involved in patients' life-style issues, and how to deal with patients' family problems. We mailed the questionnaire to 1,300 US family physicians. RESULTS: Six hundred seventy-four physicians responded. Respondents did not deal with the simulated ethical problems in a uniform manner and often tended to respond more to specific details of a case rather than the overall ethical dilemma posed. Physicians who chose a course of action giving patients more control were motivated by factors that showed respect for patient autonomy. On the other hand, physicians who chose a course of action giving patients less control were not motivated by factors suggesting a concern for patient welfare. CONCLUSIONS: Based on responses to simulated case scenarios, family physicians did not demonstrate a uniform approach but rather a more contextual one. Respect for patient autonomy was linked to family physicians' reported courses of action.

Adult↗
PubMed1991

Ethical decision making by family doctors in Canada, Britain and the United States.

Family doctors in Canada and the U.S. and general practitioners in England and Wales were sent a questionnaire containing six cases that raised moral issues. The doctors were asked to select the most appropriate course of action for each case as well as reasons for that decision. The ethical problems concerned how much information to divulge to patients, how extensively a physician should become involved in the lifestyles of patients, and how to deal with a possible family problem. The respondents selected different courses of action for the cases. More U.S. than Canadian or British physicians chose to divulge information, while more British than Canadian or U.S. physicians chose not to become involved in patients' lifestyles. Physicians who chose to divulge information were likely to be young, male, live in a small community, and have no academic affiliation. Physicians who chose not to become involved in lifestyle issues were likely to be young, church attenders, and in group practice in a small community.

Beneficence↗
PubMed1990

Retinal detachment in penetrating keratoplasty patients.

We reviewed the records of 23 patients who had retinal detachment after penetrating keratoplasty. Seventeen retinas (74%) were reattached successfully. Of the six failures, four patients had hemorrhagic choroidal detachment at the time of keratoplasty. When these complex retinal detachments are subtracted, 17 of 19 patients (89%) had successful retinal reattachments. Of the 17 successes, only seven patients had visual acuity of 20/200 or better. Retinal detachments after penetrating keratoplasty can be repaired with a high rate of success, but visual results remain disappointing.

Cataract Extraction↗
PubMed1989

Patient-centredness in the consultation. 1: A method for measurement.

This paper presents a method for assessing the doctor-patient interaction in terms of its patient-centredness. Patient-centredness was defined in terms of doctor responses which enabled patients to express all of their reasons for coming, including symptoms, thoughts, feelings and expectations. The method was tested and found to be valid (correlations for criterion validity rs = 0.51 and 0.89), reliable (inter-rater correlation rs = 0.91, intra-rater correlation rs = 0.88), and sensitive, in that it was able to detect differences among doctors (P less than 0.001) and among doctor responses to different patient offers (P less than 0.001). The method was also found to be practical in that it was inexpensive and could be used for a variety of purposes such as by tutors to give feedback to their students, by examiners as part of the evaluation of candidates' consultation skills, and by students and clinicians alike, for self-assessment. The finding that the score for the first two minutes of the consultation correlated highly with the score for the entire consultation (rs = 0.806) greatly increases the time effectiveness of the method, suggesting that it would be practical for use on a large scale, including student assessment and future studies of the relationship between patient-centredness and patient outcomes.

Attitude to Health↗
PubMed1989

Subgrouping conduct disorder by psychiatric family history.

The family history of psychiatric disorders, and clinical and demographic characteristics of boys with pervasive aggressive conduct disorder (PACD) were compared to those of boys with situational aggressive conduct disorder and controls. Boys with PACD came from lower socioeconomic backgrounds, had an earlier age of onset, and higher rates of hyperactivity and inattention than boys in the other two groups. Their mothers abused drugs more often than those of boys in the other two groups, while their fathers had more frequent antisocial behavior. Alcohol abuse was more prevalent among fathers of both conduct disorder groups, compared to the fathers of controls.

Aggression↗
PubMed1989

Ethical decision making by British general practitioners.

General practitioners in England and Wales were sent a questionnaire asking how they would handle the ethical problems posed by six case vignettes and their reasons for their decisions. The ethical problems included: how much information to divulge to patients, how extensively a physician should become involved in the lifestyles of patients and how to deal with a possible family problem. The varying patterns of response to the six cases suggested that ethical issues are resolved in a case-by-case, not a theoretical, basis.

Beneficence↗
PubMed1986

Conservation of the c-myc coding sequence in transduced feline v-myc genes.

We have cloned the normal feline c-myc locus and determined the nucleotide sequence of all three exons. The feline c-myc gene shows close homology to other mammalian c-myc genes, particularly human c-myc. The feline and human sequences are colinear within the open reading frame for the putative c-myc product but show insertions and deletions relative to each other outside this domain. We have also analyzed a cloned FeLV provirus, CT4, which contains the host-derived myc gene. In this provirus the v-myc sequences are located at the 3' end of the pol gene, replacing pol and env sequences. Nucleotide sequence analysis of CT4 shows an open reading frame for a v-myc gene product which may be expressed without fusion to any viral protein sequences. This contrasts with another FeLV v-myc (LC), in which myc and gag sequences were found to be fused. Unlike previously identified avian v-myc genes, the feline v-myc genes contain exon 1-derived sequences, but these have been truncated or internally deleted. The FeLV CT4 v-myc sequence shows very few coding changes relative to c-myc and the FeLV LC v-myc coding sequence is unchanged relative to c-myc apart from fusion to gag. These results are discussed in relation to the mechanism of transduction and activation of myc by FeLV.

Amino Acid Sequence↗
PubMed1986

Nucleotide sequences of a feline leukemia virus subgroup A envelope gene and long terminal repeat and evidence for the recombinational origin of subgroup B viruses.

Molecular clones of the subgroup A feline leukemia virus FeLV-A/Glasgow-1 have been obtained. Nucleotide sequence analysis of the 3' end of the proviral genome and comparison with the published sequence of FeLV-B/Gardner-Arnstein showed that the most extensive differences are located within the 5' domain of the env gene. Within this domain, several divergent regions of env are separated by more conserved segments. The 3' end of env is highly conserved, with only a single amino acid coding difference in p15env. The proviral long terminal repeats are also highly conserved, differing by only eight base substitutions and one base insertion. Specific probes constructed from the FeLV-A or FeLV-B env genes were used to compare the env genes of various exogenous FeLV isolates and the endogenous FeLV-related proviruses of normal cat DNA. An FeLV-A-derived env probe showed no hybridization to normal cat DNA but detected all FeLV-A and FeLV-C isolates tested. In contrast, an FeLV-B env probe detected independent FeLV-B isolates and a family of endogenous FeLV-related proviruses. Our observations provide strong evidence to support the hypothesis that FeLV-B viruses have arisen by recombination between FeLV-A and endogenous proviral elements in cat DNA.

Antigens, Viral↗
PubMed1979

The diagnosis of depression in children.

Operational criteria for depression in children were derived from diagnostic criteria designed for adults. These criteria were applied to a series of outpatients and inpatients on a Child Psychiatry Service. Thirteen per cent of girls and 5% of boys admitted to the clinic met the criteria for depression. (For this calculation autistic, brain-damaged and seriously retarded were excluded from the clinic population.) The frequencies of criterion symptoms and some related symptoms are reported. Generally the data suggest that the significant depression does occur as an independent syndrome in children, it is relatively common in a clinic population and it does not differ obviously from depression in adults.

Adolescent↗
PubMed1979

The doctor/patient relationship and its effect upon outcome.

The study of 299 chronically ill patients examined the doctor/patient relationship by asking two questions: first, what factors affect the quality of the relationship and secondly, does the doctor/patient relationship affect outcome for the patient? The doctor/patient relationship was measured by indicators of the doctor's awareness of the patient's problems.The following factors were found to be positively associated with the doctor's awareness: a small number of patient problems, a large number of recent visits, and the patient, rather than the doctor, initiating the consultation. The patient's age and education, the completeness of family care, and duration of care were not found to influence awareness. After eliminating the effect of confounding variables, the relationship between the doctor's awareness and the patient's recovery was maintained for some groups of patients. Awareness did not significantly affect the patient's satisfaction. We list some practical recommendations to aid doctors in increasing their knowledge of their patients.

Adult↗
PubMed1978

Direct and indirect measures of patient satisfaction with physicians' services.

This research examines alternative measures of patient satisfaction. Three measures were compared: (1) a direct measure to evaluate how the patient felt about his own personal physician, (2) an indirect measure that assessed attitudes about physicians in general, and (3) a measure designed to be intermediate between these two. Responses to the three measures were found to differ: the levels of satisfaction increased with the directness of the measure used; indirect evidence that this relationship could not be attributed solely to a patient's reluctance to criticize his own physician is also provided. The three measures were compared in terms of their association with other assessments of outcome and with indicators of the process of care. Although none of the associations was statistically significant, high scores on the intermediate measure tended to correspond with better outcomes and higher scores on the process of care. These findings are at least compatible with the contention than an intermediate measure provides the most valid assessment of patient satisfaction.

Adult↗
PubMed1978

A family study of unsocialized aggressive boys.

The psychiatric histories of relatives of 17 boys admitted to an inpatient unit with "unsocialized aggressive" behavior and of 19 boys admitted with other problems were investigated by means of structured interviews. The interviews were rated blind and diagnoses made on the respondents and relatives described in the family histories using research criteria. Fathers and combined parents of the probands qualified for the diagnosis of antisocial personality disorder more often than the fathers and combined parents of control boys. Uncles of probands and combined uncles and aunts more often had a history of marked antisocial behavior than the corresponding relatives of controls. Siblings of the probands more often had a history of behavior problems as children or adolescents than the siblings of controls. The data suggest an association between unsocialized aggressive reaction in boys and antisocial personality disorder in their adult relatives. Such an association is an interesting contrast to the relationship between hyperactivity in children and alcoholism in their adult relatives.

Adult↗
PubMed1978

Unsocialized aggressive boys: a follow-up study.

Twenty-two boys who met criteria for the diagnosis "unsocialized aggressive reaction" and had been admitted to an inpatient unit were followed up 21 months later. Two thirds were improved. Fighting and resistance to discipline were diminished while impulsiveness and similar traits persisted. Boys who were separated from an antisocial parent but lived in a home did better than others.

Adolescent↗
PubMed1977

Physicians' knowledge of and response to patients' problems.

The purposes of the study were: 1) to describe the extent of the physician's knowledge and his response; 2) to measure the degree of correlation among four indicators of knowledge and among four indicators of response; and 3) to measure the association between physician's knowledge and his response. There were five physicians and 299 patients in the study. All the patients had at least one chronic condition and one current complaint. The four indicators referred to the four kinds of problems considered: discomfort, worry, disturbance of daily living, and social problems. The physicians had high percentages of perfect scores on knowledge of discomfort, worry, and disturbance of daily living, but a low percentage on knowledge of social problems. Scores on response to discomfort were high but were low on response to other aspects. The correlations between knowledge and response, although statistically significant, were low for all four types of problems. It is possible that these correlations were underestimated because the physician's responses were recorded only for the three-month period of the study.

Adult↗