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Biomedical subjects

M Stewart

Publications and source records attributed to M Stewart.

At least 163 records · Page 9Linked to original sources
PubMed1998

Structural basis for amoeboid motility in nematode sperm.

Cell locomotion in amoeboid nematode sperm is generated by the vectorial assembly and bundling of filaments of the major sperm protein (MSP). MSP filaments are constructed from two helical subfilaments and here we describe the structure of putative MSP subfilament helices determined by X-ray crystallography at 3.3 A resolution. In addition to establishing the interfaces involved in polymerization, this structural model shows that the MSP helices are constructed from dimers and have no overall polarity, suggesting that it is unlikely that molecular motors play a direct role in the generation of protrusive force in these amoeboid cells.

Amino Acid Sequence↗
PubMed1998

Evaluation of a cold/flu self-care public education campaign.

The purpose of the study was to evaluate an Ontario Ministry of Health (MOH) cold/flu self-care public education campaign to reduce unnecessary patient visits to doctors. The MOH campaign consisted of an information booklet delivered to every household in an Ontario city, newspaper ads and radio spots. The program ran during January-March 1994. The evaluation consisted of: (1) 2x2 telephone survey in London (experimental area) and Windsor (comparison area), before and during the campaign; and (2) a telephone survey of London family practitioners during the campaign. In addition, data on the incidence of cold/flu visits to three hospital emergency departments and a sample of family physicians' offices were gathered. The data suggest that program rationale may have been questionable because the majority of the surveyed public were knowledgeable and self-reported appropriate doctor visits for cold/flu. Campaign evaluation showed limited impact. Message penetration was low; only one-third of London residents knew of the campaign or read the booklet. Only two of 10 questions showed increases in knowledge in London and no changes were found for beliefs, attitudes, acquisition of new health practices or self-reported visits to the doctor. The physician survey, emergency room and family physician office visit data were consistent with the public survey findings.

Adult↗
PubMed1998

Effect of the insertion/deletion polymorphism of the angiotensin-converting enzyme gene on response to angiotensin-converting enzyme inhibitors in patients with heart failure.

There is marked interindividual variation in serum and tissue angiotensin-converting enzyme (ACE) levels for which the insertion (I)/deletion (D) polymorphism in intron 16 of the ACE gene is a marker. ACE inhibitors have important effects on morbidity and mortality in heart failure. The influence of this polymorphism on the response to ACE inhibitors in patients with heart failure is not known. We studied response by ACE genotype of 34 subjects in a randomised, double-blind, crossover study comparing 6 weeks of lisinopril (10 mg, o.d.) or captopril (25 mg, t.d.s.) on 24-h blood pressure (BP) profile and on renal function in patients with symptomatic heart failure [mean left ventricular ejection fraction (LVEF), 24%]. Glomerular filtration rate (GFR), 99mTc diethylenetriaminepentaacetic acid (DTPA), and ambulatory 24-h mean arterial pressure (MAP; Spacelabs 90207) were assessed at the beginning and end of treatment periods. There was a significant relation between ACE genotype and change in MAP with captopril (mm Hg; DD group, -0.5; ID, -4.7; II, -7.4; p = 0.02) but not to lisinopril (mm Hg DD, -6.0; ID, -6.6; II, -7.4; p = 0.89) in these patients. There was no significant relation between genotype and change in GFR with captopril (percentage change from baseline: DD, +7.9; ID, +13.1; II, -0.6; p = 0.45) or lisinopril (percentage change from baseline: DD, -0.1; ID, -3.0; II, -13.3; p = 0.39), but the decline in renal function tended to be greatest in II subjects. Whereas the results are not conclusive, there may be a significant interaction between ACE genotype and response to ACE inhibitors in patients with heart failure.

Adolescent↗
PubMed1998

De novo direct duplication 2 (p12-->p21) with paternally inherited pericentric inversion 2p11.2 2q12.2.

We report a 4-year-old girl with a previously undescribed de novo duplication of 2p12->2p21 on the same homologue as a paternally inherited pericentric inversion of region 2p11.2-->2q12.2, resulting in dysmorphic features, cardiac abnormality, cleft palate, respiratory problems, severe growth retardation and developmental delay. This case raises an important question--did the paternal pericentric inversion influence the occurrence of the de novo duplication?

Abnormalities, Multiple↗
PubMed1998

Prognosis of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) contributes significantly to perinatal morbidity and mortality. This retrospective study examines the experience of a major teaching hospital to establish survival rates and factors influencing outcome. Survival rates were found to relate closely to the stage at which the diagnosis was made and the presence of associated anomalies. Ultrasound diagnosis early in pregnancy is associated with a higher mortality rate than diagnosis made late in pregnancy or after delivery. Logistic regression analysis and chi-squared analysis did not establish to a significant degree that any factor, alone or in combination, was a reliable prognostic indicator. It is acknowledged, however, that figures in this series are small. Survival figures are presented to facilitate reliable parental counselling. In particular, the presence of associated major anomalies and the gestational age at which diagnosis is made are of critical importance in accurately counselling parents regarding the prognosis for survival. In this study, excluding terminations, the mortality rate for isolated CDH diagnosis before the 21st week was 45.5%, with a corresponding survival rate of 54.5%. Once the infant was liveborn, however, the survival rate rose to 68.0%, and if the infant survived transfer to a paediatric surgical unit, the survival rate in this study was 73.9 %.

Abnormalities, Multiple↗
PubMed1998

Parental and professional perception of need for emergency admission to hospital: prospective questionnaire based study.

AIM: To compare views of parents, consultants, and general practitioners on severity of acute illness and need for admission, and to explore views on alternative services. METHOD: Prospective questionnaire based study of 887 consecutive emergency paediatric admissions over two separate three week periods in summer and winter of five Yorkshire hospitals, combined with a further questionnaire on a subsample. OUTCOME MEASURES: Parental scores of need for admission and parent and consultant illness severity scores out of 10. Consultant judgment of need for admission. Alternatives to admission considered by consultants and, for a subsample, by parents and family GP. RESULTS: Ninety nine per cent of parents thought admission was needed. Parents scored need for admission more highly than severity of illness with no association observed between severity and presenting problem or diagnosis. High parental need score was associated with a fit, past illness, and length of stay. Consultant illness severity scores were skewed to the lower range. Consultants considered admission necessary in 71%, especially for children aged over 1 year, presentation with breathing difficulty or fit, and after a longer stay. More admissions in the evening were considered unnecessary as were admissions after longer preadmission illness, gastroenteritis, or upper respiratory tract infection. Of a subsample of parents, 81% preferred admission during the acute stage of illness even if home nursing had been available. Similar responses were obtained from GPs. Alternative services could have avoided admission for 19% of children, saving 15.6% of bed days used. CONCLUSIONS: Medical professionals and parents differ in their views about admission for acute illnesses. More information is needed on children not admitted. Alternative services should take account of patterns of illness and should be acceptable to parents and professionals; cost savings may be marginal.

Acute Disease↗
PubMed1998

Medical and social factors associated with the admission and discharge of acutely ill children.

AIM: To examine medical and sociodemographic factors involved in acute paediatric admission. To compare outcome of admission with factors present at time of admission. METHODS: Prospective questionnaire based study of 887 consecutive emergency general paediatric admissions to five Yorkshire hospitals during two separate three week periods in summer and winter. MAIN OUTCOME MEASURES: Discharge diagnosis, length of stay. RESULTS: Most admissions (53%) occurred "out of hours" with a peak during the evening. Two thirds (64%) of patients were under 3 years of age and clinical problems varied with age. Self referral via an accident and emergency department occurred in one third and was more likely after a fit in older children and in more socioeconomically deprived children. The most frequent presenting problems were breathing difficulty (24%), fit (16%), and feverish illness (15%). One quarter (24%) were discharged within 24 hours and 61% spent, at most, one night in hospital. Length of stay was shorter for night admissions and longer for children with a discharge diagnosis of asthma. Although most children had mild, self limiting illnesses, serious illness was subsequently found in 13% and could not be predicted from the presenting problems. CONCLUSIONS: Current demand on emergency paediatric admission is mainly from young children with mild self limiting illnesses who spend one night or less in hospital. Changes in delivery of care to acutely ill children must take account of the pattern and nature of presenting problems and be rigorously audited to ensure that improvements in the health of children continue.

Acute Disease↗
PubMed1998

Decisions and justifications by community mental health providers about hypothetical ethical dilemmas.

OBJECTIVE: Community-based treatment of persons with serious mental illness requires providers to become involved in clients' personal lives to a greater degree than does hospital-based treatment. The study examined attendant ethical dilemmas, especially for staff who lack professional training or work in rural communities. METHODS: A total of 95 staff members from five community mental health centers read 14 vignettes describing ambiguous ethical dilemmas involving professional role boundaries or client confidentiality. Twenty-seven staff members were from rural agencies, and 68 from urban-suburban agencies; 60 were direct care staff, and 35 were supervisory. Participants were asked to make and justify a more conservative or a less conservative decision in response to each dilemma. RESULTS: Years of experience as a mental health provider and previous ethics training correlated positively with staff having experienced more situations similar to those in the vignettes; however, these variables were not related to the decision made or the type of ethical justification for it. When the analysis controlled for experience and previous ethics training, staff made fewer conservative decisions in boundary dilemmas than in confidentiality dilemmas. Compared with nonrural providers, rural providers had experienced more boundary dilemmas and made fewer conservative decisions in response to them. CONCLUSIONS: Boundary problems occur frequently in community-based services, especially in rural settings, and may or may not be handled conservatively. With the expansion of case management and other in vivo services, better understanding of ethical risks and informal practices will help improve services and provide appropriate training and supervision of staff.

Adult↗
PubMed1998

Systematic analysis of snoring in women.

Nineteen percent of women are habitual snorers, yet most snoring studies report only on male snorers. The aim of this study was to identify the factors responsible for habitual snoring in women. Twenty-four snorers and 16 controls were studied prospectively in a special snoring clinic. Snorers were shorter (p = .005) and heavier (p = .001), and with greater body mass index (BMI: p < .001), collar size (p = .002), and submental skinfold thickness (p = .001) than controls. The area of the posterior pharyngeal wall visible on oral examination was smaller in snorers (p = .005). Acoustic rhinometry areas and volumes were similar in the two groups. Nasal flow-volume loops showed reduced expiratory (p = .01) and inspiratory (p = .07) flow in snorers. Inspiratory flow correlated inversely with nasal symptoms (p < .05). The factors that best predict habitual snoring in women are a high BMI, a high nasal symptom score, and heavy weight. Of these, BMI is the most powerful.

Adolescent↗
PubMed1998

Effects of two repair strategies on speechreading of words and sentences.

The effectiveness of two repair strategies, repetition and paraphrasing, in enhancing speechreading performance was evaluated on 20 young adults with normal hearing using both word and sentence test stimuli. Both strategy types produced significant improvement, and the repeat strategy yielded the greatest gains overall. Paraphrasing resulted in the most enhancement for words, while repetition was the most effective of the two strategies with sentences. The inclusion of both repair strategies is recommended in communication therapy with the hearing impaired.

Adult↗
PubMed1998

Effect of fetal alcohol exposure on adult symptoms of nicotine, alcohol, and drug dependence.

OBJECTIVES: The objective of this study is to examine the effect of fetal alcohol exposure on later substance dependence using an adoption study method. METHODS: One hundred ninety-seven adoptees were interviewed for substance abuse disorders, including nicotine, alcohol, and drug dependence. Twenty-one adoptees had mothers who drank during pregnancy. Adoptees with fetal alcohol exposure were compared with those without fetal alcohol exposure for symptoms of adult nicotine, alcohol, and drug dependence. RESULTS: Adoptee symptom counts for alcohol, drug, and nicotine dependence were higher for those exposed to alcohol in utero. The effect of fetal alcohol exposure remained after controlling for gender, biological parent alcohol dependence diagnosis, birth weight, gestational age and other environmental variables. CONCLUSIONS: Fetal alcohol exposure may produce increased risk for later nicotine, alcohol, and drug dependence. Possible effects of fetal alcohol exposure on development of adult substance use patterns needs attention in genetic studies of substance abuse.

Adolescent↗
PubMed1998

Roles and influence of people who accompany patients on visits to the doctor.

OBJECTIVES: To determine the proportion of patients who are accompanied by another person (ie, partner, child, relative, friend) during visits to their doctors; to describe the demographic characteristics and role(s) assumed by the main accompanying person and the nature of the presenting dyads; and to describe the influence of the main accompanying person on the patient-doctor interaction. DESIGN: Prospective observational survey. SETTING: Family practices in London, Ont, and surrounding area. PARTICIPANTS: Eight family physicians completed surveys on 100 consecutive patients attending for both regularly scheduled and emergency visits. MAIN OUTCOME MEASURES: Roles and influence of the main accompanying person. RESULTS: Approximately one third (30.4%) of patients were accompanied during visits to their doctors. Children and patients older than 75 years most frequently had another person with them. Most patients (74.1%) were accompanied by one person who most often was female (72.6%) and between the ages of 21 and 40 years (53.6%). The accompanying person's role was most frequently described by doctors as an advocate for the patient (n = 235, 68.5%). If the accompanying person was a child, however, the role was most often described as a silent observer (n = 36, 68.6%). The influence of the main accompanying person on the patient-doctor encounter was usually described as positive (95.1%). CONCLUSIONS: Physicians report that people accompanying patients usually have a positive influence on medical encounters. Future studies need to include patients' and accompanying persons' perspectives.

Adolescent↗
PubMed1998

Open versus closed diagnostic peritoneal lavage: a comparison on safety, rapidity, efficacy.

There is considerable debate between the proponents of open and closed diagnostic peritoneal lavage (DPL). A prospective study was undertaken on 130 patients submitted to DPL. We performed 55 (42.3%) closed and 75 (57.7%) open lavages with sensitivity and specificity of 100 and 96.6% for the former and 92.2 and 100% for the latter. The mean time for insertion of the catheter and initiation of fluid infusion was significantly less in the closed DPL group, and so were the number of cases with prolonged procedures. No intra-abdominal or wound complications were detected with either method, but there were 10 DPL failures due to inability to conclude the procedure successfully and derive a definite result. Eight of these (10.6%) belonged to the open group and two (3.6%) to the closed (P < 0.05). Our findings suggest closed DPL is as equally sensitive and specific as closed DPL, but is more expeditious and offers inconclusive results less often. Both procedures are useful and should be parts of surgical training.

Abdominal Injuries↗
PubMed1998

Changing face of family practice.

OBJECTIVE: To identify trends in family practice in London, Ont, between 1974 and 1994. DESIGN: Interview survey of all London family physicians in 1974. Questionnaire surveys in 1984 and 1994. SETTING: City of London, Ont. PARTICIPANTS: One hundred twenty-eight family physicians and general practitioners practising in London in 1974, 180 in 1984, and 237 in 1994. RESULTS: The percentage of female practitioners, practitioners with no in-hospital patients, and practitioners making no home visits in an average week increased significantly. The percentage of solo practitioners and family physicians practising obstetrics decreased significantly. Changes were found in the numbers of patients seen, in weekend coverage, in evening, and Wednesday afternoon office hours, and in level of satisfaction with practice. CONCLUSION: Fewer physicians cared for in-hospital patients, made home visits, practised solo, and delivered babies in 1994 than in 1974. Substantially more women were practising family medicine in 1994 than in 1974. The trend away from in-hospital care, with no corresponding increase in home care, raises questions about how urban family physicians can maintain certain clinical skills.

Family Practice↗