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Biomedical subjects

R Freeman

Publications and source records attributed to R Freeman.

At least 127 records · Page 7Linked to original sources

Complexity of middle cerebral artery blood flow velocity: effects of tilt and autonomic failure.

We examined spectral fractal characteristics of middle cerebral artery (MCA) mean blood flow velocity (MFV) and mean arterial blood pressure adjusted to the level of the brain (MAPbrain) during graded tilt (5 min supine, -10 degrees, 10 degrees, 30 degrees, 60 degrees, -10 degrees, supine) in eight autonomic failure patients and age- and sex-matched controls. From supine to 60 degrees, patients had a larger drop in MAPbrain (62 +/- 4.7 vs. 23 +/- 4.5 mmHg, P < 0.001; means +/- SE) and MFV (16.4 +/- 3.8 vs. 7.0 +/- 2.5 cm/s, P < 0.001) than in controls. From supine to 60 degrees, there was a trend toward a decrease in the slope of the fractal component (beta) of MFV (MFV-beta) in both the patients and the controls, but only the patients had a significant decrease in MFV-beta (supine: patient = 2.21 +/- 0.18, control = 1.99 +/- 0.60; 60 degrees: patient = 1.46 +/- 0.24, control = 1.62 +/- 0.19). The beta value of MAPbrain (MAPbrain-beta; 2.19 +/- 0.05) was not significantly different between patients and controls and did not change with tilt. High and low degrees of regulatory complexity are indicated by values of beta close to 1.0 and 2.0, respectively. The increase in fractal complexity of cerebral MFV in the patients with tilt suggests an increase in the degree of autoregulation in the patients. This may be related to the drop in MAPbrain. The different response of MFV-beta compared with that of MAPbrain-beta also indicates that MFV-beta is related to the regulation of cerebral vascular resistance and not systemic blood pressure.

Adult↗

Cerebrovascular and cardiovascular responses to graded tilt in patients with autonomic failure.

BACKGROUND AND PURPOSE: Patients with autonomic nervous system failure often experience symptoms of orthostatic intolerance while standing. It is not known whether these episodes are caused primarily by a reduced ability to regulate arterial blood pressure or whether changes in cerebral autoregulation may also be implicated. METHODS: Eleven patients and eight healthy age- and sex-matched control subjects were studied during a graded-tilt protocol. Changes in their steady state middle cerebral artery mean flow velocities (MFV), measured by transcranial Doppler, brain-level mean arterial blood pressures (MABPbrain), and the relationship between the two were assessed. RESULTS: Significant differences between patients and control subjects (P < .05) were found in both their MFV and MABPbrain responses to tilt. Patients' MFV dropped from 60 +/- 10.2 cm/s in the supine position to 44 +/- 14.0 cm/s at 60 degrees head-up tilt, whereas MABPbrain fell from 109 +/- 11.7 to 42 +/- 16.9 mm Hg. By comparison, controls' MFV dropped from 54 +/- 7.8 cm/s supine to 51 +/- 8.8 cm/s at 60 degrees, whereas MABPbrain went from 90 +/- 11.2 to 67 +/- 8.2 mm Hg. Linear regression showed no significant difference in the MFV-MABPbrain relationship between patients and control subjects, with slopes of 0.228 +/- 0.09 cm.s-1.mm Hg-1 for patients and 0.136 +/- 0.16 cm.s-1.mm Hg-1 for control subjects. CONCLUSIONS: The present study found significant differences between patients and control subjects in their MFV and MABPbrain responses to tilt but no difference in the autoregulatory MFV-MABPbrain relationship. These results suggest that patients' decreased orthostatic tolerance may primarily be the result of impaired blood pressure regulation rather than a deficiency in cerebral autoregulation.

Adult↗

Transfer function analysis of cerebral autoregulation dynamics in autonomic failure patients.

BACKGROUND AND PURPOSE: Autonomic nervous system diseases affect systemic blood pressure regulation. Patients with autonomic nervous system diseases have consistently larger drops in blood pressure associated with standing than the normal population. Autonomic dysfunction and/or these changes in blood pressure may affect dynamic cerebral autoregulation. METHODS: Heart rate, mean blood flow velocity (MBFV) of the middle cerebral artery via transcranial Doppler ultrasound, mean arterial blood pressure adjusted to brain level (MABPbrain) via Finapres, and end tidal CO2 were measured continuously during graded tilt (after 5 minutes in supine position as baseline, -10 degrees, +10 degrees, +30 degrees, +60 degrees, -10 degrees, and supine recovery) in autonomic failure patients and their age- and sex-matched control subjects. The dynamic response of MBFV to spontaneous variations in MABPbrain was investigated by cross-spectral analysis. The transfer gain and phase relationships between MBFV and MABPbrain were determined from the final 256 beats of each 5-minute-tilt segment. The transfer gain was normalized to mean MABPbrain and MBFV and then converted to decibels (dB). RESULTS: MBFV variation (0.03 to 0.14 Hz) preceded MABPbrain by similar phase angles in patients and control subjects and in all tilt conditions (patients: 31 +/- 5 degrees; control subjects: 30 +/- 5 degrees; mean +/- SEM). Patients had a higher supine gain than control subjects (P < .05). Both patients and control subjects showed a significant decrease in gain with tilt and by 60 degrees the patients were not different from the control subjects (supine to 60 degrees: patients = 5.23 +/- 0.77 to -1.65 +/- 0.89 dB; control subjects = 1.74 +/- 0.82 to -1.80 +/- 0.62 dB). CONCLUSIONS: These data indicate an altered, yet present, autoregulatory response with autonomic failure.

Autonomic Nervous System Diseases↗

Cardiovascular autonomic tests in diabetic patients with gastroparesis.

The aim of this report was to study the cardiovascular autonomic tests in the evaluation of diabetic patients with gastroparesis. Forty diabetic subjects were divided into two groups: one group with gastroparesis (GP, n = 20) and another group paired by age and duration of diabetes without any complaint of autonomic neuropathy (DC, n = 20). They were evaluated clinically and submitted to a battery of five cardiovascular autonomic tests. The presence and severity of autonomic neuropathy were defined according to the number of normal cardiovascular tests. Each test had a score: zero (normal), one (borderline) and two (abnormal). The GP group showed a higher abnormal total score in the cardiovascular autonomic test than the group without any complaint (6.6 +/- 3.0 vs. 2.7 +/- 1.4, p < 0.01). These data suggest that diabetic with gastroparesis presents more abnormal cardiovascular autonomic tests than diabetic without autonomic neuropathy and these tests should be included in the evaluation of diabetic patients with gastroparesis.

Adult↗

The provision of primary dental care for patients with special needs.

The Community Dental Service (CDS) has increasingly become associated with providing primary dental care for those people who are unable to access care by the usual means. The work reported here examines the provision of primary dental care by using the notion of a dental service continuum to demonstrate that in the treatment of patients with special needs the CDS acts as a safety net service. One hundred and twenty-four General Dental Service (GDS) practices and 33 CDS practices took part in the survey. The results suggest that both services provide primary dental care for a wide range of patients with special needs. Dentists in the GDS and CDS treat and care for different populations of patients with special needs. It is proposed that a continuum of service provision exists.

Dental Care for Persons with Disabilities↗

Accessing primary dental care in three London boroughs.

OBJECTIVE: To investigate and identify factors that may influence individuals' ability to access primary health care services. DESIGN: Cross-sectional study SETTING: Lambeth, Southwark and Lewisham. SUBJECTS: A 0.1 per cent random sample of people aged 18 years and over in the population of 626,621 people in the three boroughs. MAIN OUTCOME MEASURES: Demographic as well as psychosocial profile of the sample, perceptions of their dental health needs, accessed dental care. RESULTS: The results indicated that people believed that their oral health was good. The majority of the sample had attended for dental care within the previous year and were registered with a general dental practitioner. Accessing dental care was related to age, social class, borough of residence, dentate status and dental phobia status. In addition subjects experiencing problems with their teeth gained access to care more readily than others. This was related to social class. Accessing dental care was predicted by dental care being provided by a general dental practitioner, experiencing problems with teeth and not being dentally phobic. CONCLUSIONS: The findings suggest that psychosocial factors together with dental health status can act as determinants when accessing primary dental services. It is considered that family health services authorities should be aware of these influences when developing and monitoring dental health services, in order to make them responsive and sensitive to the needs of the people whom they serve.

Adolescent↗

Towards effective mentoring in general practice.

In South Thames, a three-year feasibility study was designed to explore the potential contribution of mentors in furthering professional development and increasing a sense of well-being among general practitioners. The study led to the establishment of an ongoing mentor project as a South Thames (West) Regional initiative, funded by the Postgraduate Dean of General Practice. This paper outlines the project's structure and administration. The concept of the holistic mentor model, together with a strategy (the reflective cycle) for purposeful intervention, is also described. The findings from the evaluation of the study illustrate the response of doctors to their mentor training, their early experience of taking on the role of mentor, and their reporting of the experience of those being mentored (the mentees). The issues relevant to the future of mentoring are commented on, to inform and encourage further discussion.

Attitude of Health Personnel↗

Cytomegalovirus immune globulin (CMVIG) prophylaxis is associated with increased survival after orthotopic liver transplantation. The Boston Center for Liver Transplantation CMVIG Study Group.

Cytomegalovirus (CMV) causes considerable morbidity and mortality in orthotopic liver transplant (OLT) recipients. Several prophylactic strategies against CMV have been studied in solid organ transplant recipients, including cytomegalovirus immune globulin (CMVIG). We examined the effect of CMVIG prophylaxis on first-year and long-term survival after liver transplantation. Data were analysed for 162 OLT recipients from four transplant centers in Boston who participated in two CMVIG prophylaxis trials. Ninety patients received CMVIG (median follow-up 5.6 yr), and 72 patients received placebo (median follow-up 5.4 yr). CMVIG prophylaxis was shown to be associated with increased first-year (86% vs. 72%, p = 0.029) and long-term (68% vs. 54%, p = 0.055) survival. The distribution of baseline characteristics including donor and recipient demographics, donor CMV serostatus, United Network for Organ Sharing (UNOS) status, pre-transplant renal and liver function tests, transplantation surgical time, number of units of blood products administered during transplantation, primary immunosuppressive regimen, use of solumedrol or antilymphocyte therapy for induction of immunosuppression or treatment of rejection, and surgical complications was similar for CMVIG and placebo recipients. CMVIG recipients were more likely to have primary biliary cirrhosis than placebo recipients (21% vs. 8%, p = 0.025). Using a Cox proportional hazards multivariate model to control for pre-transplant liver disease, CMVIG was shown to be independently associated with increased first-year survival (p = 0.042); a trend toward association with increased long-term survival (p = 0.098) was also shown. These data support that CMVIG prophylaxis, beyond its proven efficacy in decreasing the incidence of severe CMV-associated disease, is associated with increased survival when used prophylactically in OLT recipients.

Adolescent↗

The dental health status of five-year-old children in north and west Belfast.

OBJECTIVE: To investigate the influence of social deprivation upon the diet, dental health behaviours and dental health status of five-year-old children in Northern Ireland. DESIGN: Cross-sectional study. SETTING: Fifty-eight primary schools in North and West Belfast. SUBJECTS: A nine per cent (240) random sample of 2,666 five-year-old children resident and attending school in North and West Belfast. MAIN OUTCOME MEASURES: Dental health status measured by dmft index; parental assessments of the child's dental health behaviours: parental dental attendance patterns and attitudes towards dental health; parental assessments of the child's diet and snacking behaviours: parental attitudes towards snack foods; and demographic profile of child's family. RESULTS: One hundred and sixty-three children were examined, a 68 per cent response. The majority of the families were either in low income employment or unemployed. Sixty-eight per cent of children had experience of dental caries. Dental decay was unrelated to parental employment status but more children from unemployed families attended when in pain. The diet of the children was related to both employment status and parental attitude and was reflected in their caries experience. Caries experience was dependent upon parental dental attendance, the consumption of carbonated drinks and sugar containing bedtime drinks. CONCLUSIONS: The results suggest that unemployment and parental attitudes are important as determinants of dental caries in five-year-old children from North and West Belfast. These factors may influence the child's dental health care as well as type of diet.

Attitude to Health↗

The triangle of health. 1: The clinical arena.

The triangle of health is based upon a holistic view of health and is composed of physical, psychological and social dimensions. It is by an acknowledgement of these various aspects of health that restorative treatment and preventive plans can best be negotiated with patients and tailored to their physical, psychological and social needs.

Dental Anxiety↗

The triangle of health: applications for general practice, Part 2: The dental team.

The triangle of health (physical, psychological and social) allows the dental health professional to appreciate the importance of the holistic view of health. The three dimensions of health are as applicable to the health and well-being of the dental health professional as they are to the patients they treat. Parallels between physical, psychological and social determinants of oral health for the patient are related to those for the health of the dental team members. Through an awareness of such matters dental health professionals can promote health for their patients and themselves.

Burnout, Professional↗

Does adjunctive fluoxetine influence the post-hospital course of restrictor-type anorexia nervosa? A 24-month prospective, longitudinal followup and comparison with historical controls.

A 24-month naturalistic, prospective longitudinal followup study was conducted on 33 patients with anorexia nervosa who had participated in an intensive, multidisciplinary inpatient treatment program and were receiving fluoxetine as part of their continuing treatment regimen. Data on course, outcome, and treatment exposure in this cohort were obtained using standardized, comprehensive interviews administered at 6-month intervals after hospital discharge. Longitudinal course data for these patients were compared with data for matched historical controls who had received identical inpatient and followup treatment but without adjunctive fluoxetine. Analyses failed to show that fluoxetine had a significant effect on the cumulative probability of remaining at target weight during the followup period, the risk of sustained weight loss, or other clinical measures of outcome. Thus, adjunctive treatment with fluoxetine may not have additive long-term therapeutic benefit when measured against the effects of sustained and intensive followup treatment.

Adolescent↗

Incidence and predictors of cytomegalovirus pneumonia in orthotopic liver transplant recipients. Boston Center for Liver Transplantation CMVIG Study Group.

The incidence, predictors, and outcome of cytomegalovirus pneumonia in OLT recipients have not been well defined. We conducted an analysis of prospectively collected data from 141 OLT recipients who were included as part of a randomized, placebo-controlled trial of CMV immune globulin prophylaxis. Cytomegalovirus pneumonia was diagnosed in 13 of 141 (9.2%) OLT recipients during the first year posttransplant and was associated with a higher 1-year mortality compared with those recipients without CMV pneumonia (84.6 vs. 17.2%, P=0.0001). Univariate analysis demonstrated that CMV viremia (P=0.001), invasive fungal disease (P=0.0001), donor(+)/pretransplant recipient(-) CMV serologic status (P=0.013), abdominal operation (excluding retransplantation) after liver transplantation (P=0.0027), bacteremia (P=0.0105), and advanced United Network of Organ Sharing status (P=0.023) were associated with CMV pneumonia. Cytomegalovirus viremia was diagnosed in 11 of 13 patients with CMV pneumonia at a median of 11 days (range 1-66 days) before diagnosis of CMV pneumonia. In a multivariate analysis using a time-dependent, Cox proportional hazards model, CMV viremia (RR=8.6, 95% CI 1.8-39.7, P=0.0012), invasive fungal disease (RR=6.5, 95% CI 2.1-20.3, P=0.0001), and abdominal reoperation (RR=4.4, 95% CI 1.4-13.1, P=0.0043) were found to be independent predictors of CMV pneumonia. The attributable mortality associated with CMV pneumonia within the first year after liver transplantation for the patients with CMV pneumonia was 67.4%. Intensified measures for prevention of CMV should be considered for patients at high risk of developing CMV pneumonia.

Adult↗

Dentists practising in Lothian treat HIV seropositive patients: is this a resolution of conflict or a case of Hobson's choice?

Dentists are now required to treat HIV-positive patients in their practices. Dentists working in high HIV prevalence areas treat HIV seropositive patients but what affects this treatment decision? The aim of this study is to investigate the role of conflict with regard to treatment decisions. All 371 dentists practising in Lothian were sent a questionnaire. Two hundred and fifteen questionnaires were returned giving a valid response rate of 60%. The findings of this study would support the view that dentists are able to use their scientific knowledge which reduces anxieties and assists in the resolution of their conflict with regard to the treatment of HIV seropositive patients.

Acquired Immunodeficiency Syndrome↗