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Biomedical subjects

B Williams

Publications and source records attributed to B Williams.

At least 163 records · Page 9Linked to original sources
PubMed1999

The reproducibility of central aortic blood pressure measurements in healthy subjects using applanation tonometry and sphygmocardiography.

AIM: Sphygmocardiography via applanation tonometry is a non-invasive, bedside technology which utilises tonometric analysis of the radial artery pulse wave and measurement of peripheral arterial blood pressure (BP) to derive a central arterial pulse wave, central arterial BP and related indices. The present study was designed to determine: (1) the inter-operator variability in measurements obtained using this technique; (2) the relationship between measured peripheral arterial BP and derived central arterial BP. METHOD: Multiple measurements were made from 25 healthy subjects (15 male), mean age 33 (s.d. 10.3) years, mean arterial BP 90 (s.d. 12) mm Hg by two trained observers at the same time of day on three separate occasions. RESULTS: The mean inter-operator difference was 0.1 (s.d. 1.7) mm Hg for derived systolic aortic BP and 0.1 (s.d. 0.7) mm Hg for derived diastolic aortic BP (Bland and Altman analysis). Pulse wave Augmentation Index (AIx) values, ranged from -22% to +40%, with the inter-operator measurement difference being only 0.4 (s.d. 6.4)%. Buckberg ratio measurements ranged from 119% to 254%, with the inter-operator measurement difference being only 2.7 (s.d. 15.4)%. The relationship between derived central systolic BP and peripheral systolic BP readings in individual patients was not constant and showed significant variance when compared on different days (ANOVA, P = 0.03). This was not explained by any significant variance in heart rate (ANOVA, P = 0.39). CONCLUSION: Applanation tonometry has excellent inter-observer reproducibility when used by trained observers. Moreover, the inconsistency in the relationship between peripheral and central aortic BP suggests that the former is not a perfect surrogate for the latter. Further prospective studies are required to define whether derived central aortic BP may be a better predictor of cardiovascular morbidity and mortality and the impact of different antihypertensive therapies on the relationship between peripheral and central arterial BP.

Adult↗
PubMed1999

Guidelines for management of hypertension: report of the third working party of the British Hypertension Society.

Use non-pharmacological measures in all hypertensive and borderline hypertensive people. Initiate antihypertensive drug therapy in people with sustained systolic blood pressures (BP) >/=160 mm Hg or sustained diastolic BP >/=100 mm Hg. Decide on treatment in people with sustained systolic BP between 140 and 159 mm Hg or sustained diastolic BP between 90 and 99 mm Hg according to the presence or absence of target organ damage, cardiovascular disease or a 10-year coronary heart disease (CHD) risk of >/=15% according to the Joint British Societies CHD risk assessment programme/risk chart. In people with diabetes mellitus, initiate antihypertensive drug therapy if systolic BP is sustained >/=140 mm Hg or diastolic BP is sustained >/=90 mm Hg. In non-diabetic hypertensive people, optimal BP treatment targets are: systolic BP <140 mm Hg and diastolic BP <85 mm Hg. The minimum acceptable level of control (Audit Standard) recommended is <150/<90 mm Hg. Despite best practice, these levels will be difficult to achieve in some hypertensive people. In diabetic hypertensive people, optimal BP targets are; systolic BP <140 mm Hg and diastolic BP <80 mm Hg. The minimum acceptable level of control (Audit Standard) recommended is <140/<90 mm Hg. Despite best practice, these levels will be difficult to achieve in some people with diabetes and hypertension. In the absence of contraindications or compelling indications for other antihypertensive agents, low dose thiazide diuretics or beta-blockers are preferred as first-line therapy for the majority of hypertensive people. In the absence of compelling indications for beta-blockade, diuretics or long acting dihydropyridine calcium antagonists are preferred to beta-blockers in older subjects. Compelling indications and contraindications for all antihypertensive drug classes are specified. For most hypertensives, a combination of antihypertensive drugs will be required to achieve the recommended targets for blood pressure control. Other drugs that reduce cardiovascular risk must also be considered. These include aspirin for secondary prevention of cardiovascular disease, and primary prevention in treated hypertensive subjects over the age of 50 years who have a 10-year CHD risk >/=15% and in whom blood pressure is controlled to the audit standard. In accordance with existing British recommendations, statin therapy is recommended for hypertensive people with a total cholesterol >/=5 mmol/L and established vascular disease, or 10-year CHD risk >/=30% estimated from the Joint British Societies CHD risk chart. Glycaemic control should also be optimised in diabetic subjects. Specific advice is given on the management of hypertension in specific patient groups, ie, the elderly, ethnic subgroups, diabetes mellitus, chronic renal disease and in women (pregnancy, oral contraceptive use and hormone replacement therapy). Suggestions for the implementation and audit of these guidelines in primary care are provided.

Antihypertensive Agents↗
PubMed1999

Ethics for orthodontists.

When treating children, important ethical issues may arise relating to the best interests of the child and decision making for minors. The case of a child with a cleft lip and palate whose parents failed to bring her in for medically indicated orthodontic care is presented. Ethical features of the case are discussed, including the need to benefit the patient, avoid harm, and respect the preferences of the parents. Ethical codes of the American Dental Association and American Medical Association are referenced. Ethical dilemmas include the conflict between the orthodontist's obligation to the child and the need to respect parental autonomy. Parental autonomy is respected up until the point at which significant harm to a child may result. The orthodontist's primary ethical responsibility is to the child, not the parents. The orthodontist providing medically indicated care should involve the craniofacial team or hospital social worker when parental decision making is in question.

Child↗
PubMed1999

Herbicide residues in grapes and wine.

The persistence of several common herbicides from grapes to wine has been studied. Shiraz, Tarrango and Doradillo grapes were separately sprayed with either norflurazon, oxyfluorfen, oxadiazon or trifluralin-persistent herbicides commonly used for weed control in vineyards. The dissipation of the herbicides from the grapes was followed for 28 days following treatment. Results showed that norflurazon was the most persist herbicide although there were detectable residues of all the herbicides on both red and white grapes at the end of the study period. The penetration of herbicides into the flesh of the grapes was found to be significantly greater for white grapes than for red grapes. Small-lot winemaking experiments showed that norflurazon persisted at levels close to the initial concentration through vinification and into the finished wine. The other herbicides degraded, essentially via first-order kinetics, within the period of "first fermentation" and had largely disappeared after 28 days. The use of charcoal together with filter pads, or with diatomaceous earth was shown to be very effective in removing herbicide residues from the wine. A 5% charcoal filter removed more than 96% of the norflurazon persisting in the treated wine.

Herbicides↗
PubMed1999

Anaesthesia for strabismus surgery: a regional survey.

An increase in the demand by local surgeons for neuromuscular block during strabismus surgery, and the forced duction test in particular, led us to review the literature and conduct a regional survey of anaesthetic techniques used. A questionnaire was distributed to 379 anaesthetists in the region and 264 responses were received. The results demonstrated that 55% of paediatric patients and 66% of adult patients may have been operated on under suboptimal conditions; residual tone may have been present in the extraocular muscles during forced duction testing and strabismus correction.

Adolescent↗
PubMed1999

'Instilling the strength to fight the pain and get on with life': learning to become an arthritis self-manager through an adult education programme.

The aim of this study was to determine whether the Arthritis Self-Management Programme (ASMP) is effective in promoting perceived control and self-management ability when delivered in an adult education setting. The study was a pre-test-post-test design based on a sample of 89 people attending an ASMP. Data were collected by self-administered questionnaires prior to the intervention and after the intervention, 4 months from baseline. The sample comprised 80% women, with a mean age of 57 years and a mean disease duration of 13 years. Most participants had either osteoarthritis or rheumatoid arthritis. After 4 months, participants demonstrated significant increases in arthritis self-efficacy (P < 0.0005), cognitive symptom management (P < 0.0005), communication with doctors (P = 0.018), exercise (P = 0.003) and relaxation (P < 0.00005). In addition, significant decreases were found in terms of pain (P = 0.034) and visits to other health professionals (P = 0.004). The first evaluation of the ASMP, delivered within the context of adult education, suggests that this form of community health education programme can offer substantial benefits for participants, particularly in terms of perceived ability to control various aspects of arthritis and in greater utilization of cognitive-behavioral techniques.

Adaptation, Psychological↗
PubMed1999

Mentoring program for minority faculty at the University of Pennsylvania School of Medicine.

Research indicates that having a faculty mentor and being part of an active network of peers are critical ingredients of successful academic medicine careers. Minority physicians, however, often do not have mentors, and the problem is greatest for minority groups underrepresented in medicine. The University of Pennsylvania School of Medicine in 1994-1996 undertook to learn the extent of mentoring programs in its departments and divisions and to compare the experiences of underrepresented-minority faculty and others. The results were used to establish a system for mentoring and networking support for minority faculty members. Examining the reports of division and department heads on their formal mentoring programs, it was clear that these leaders considered a mentor essential for career development, but many reported having no systematic plan for mentors for junior faculty. In looking at the reported experiences of minority and non-minority assistant professors (matched for promotion track, department, appointment date, and, where possible, gender), it was found that approximately half of either group did not have mentors. As a result of this information, the school established a faculty development program to meet the faculty members' demonstrated needs: annual career development meetings with new minority faculty; assistance in identifying and assigning mentors; assistance in developing research skills; and monitoring of the retention of minority faculty. As experience with the program produces additional insights into the needs of minority faculty--and particularly of junior faculty--the program will be adjusted and expanded to meet these identified needs.

Adult↗
PubMed1999

Primary care physicians' participation in managed care networks.

The study described in this article explored the relationships between primary care physician characteristics and patterns of managed care affiliation in a single region. Secondary data sources were used to investigate the affiliations of all primary care physicians in King County, Washington (Seattle and environs) with 29 managed care products in 1996. Descriptive findings indicate that specialty, board certification, and experience all are associated with the managed care affiliations held by physicians. Differences between managed care product provider lists suggest that there are different strategies for the design and management of provider networks.

Case Management↗
PubMed1999

Seeing the wood for the trees: defining the forgotten concept of patient dissatisfaction in the light of patient satisfaction research.

Studies of patient satisfaction are regarded by many as the most important way to obtain patients' views. To date, relatively few studies have focussed specifically on dissatisfaction. Concerns have been expressed about the validity of the concept of satisfaction. Dissatisfaction, however, has received little attention since it has been assumed to be the opposite of satisfaction and thus already defined. Therefore a series of assumptions have also been made about dissatisfaction, which may or may not compromise its validity or usefulness. The aim of this review is to clarify the concept of dissatisfaction by examining what studies of patient satisfaction can and cannot tell us about dissatisfaction; identifying assumptions; and finally by suggesting how research might best be oriented to accommodate the complexity of patient experiences.

Attitude to Health↗
PubMed1999

Latent Pneumocystis carinii infection in commercial rat colonies: comparison of inductive immunosuppressants plus histopathology, PCR, and serology as detection methods.

Histopathologic evaluation combined with a period of immunosuppression has been the standard procedure for detection of Pneumocystis carinii in commercial rat colonies. Variation in induction regimens and in the sensitivity of detection methods may result in underreporting of the presence of P. carinii in breeding colonies or delay its detection. In the present study, methylprednisolone and cyclophosphamide were evaluated for the ability to induce P. carinii infection in rats from an enzootically infected commercial barrier colony. The presence of P. carinii was detected by histopathologic methods and by amplification of a targeted region of the P. carinii thymidylate synthase gene by PCR over the 8-week study period. Sera taken from rats prior to either induction regimen were evaluated for the presence of P. carinii-specific antibodies by the immunoblotting technique. Few significant differences in ability to induce organism burden or in histopathology were observed between the two immunosuppressive regimens. However, a dramatic loss of weight over the study period was observed in rats treated with methylprednisolone but not in rats treated with cyclophosphamide. Although histopathologic changes attributable to P. carinii did not appear before 2 weeks with either immunosuppressant, the presence of the organism in these animals was detected by immunoblotting and PCR. Cyst scores and the intensities of the histopathologic lesions increased during the study period, but the number of rats exhibiting evidence of P. carinii infection did not change after week 3. These results suggest that use of the PCR method on postmortem lung tissue of rats without prior induction regimens or identification of anti-P. carinii antibodies in antemortem serum samples is a sufficiently sensitive method for detection of the presence of a P. carinii carrier state in rodent breeding colonies.

Animals↗
PubMed1999

Risk factors for pulmonary mycobacterial disease in South African gold miners. A case-control study.

Pulmonary mycobacterial disease is common in miners. Risk factors for nontuberculous pulmonary mycobacterial (NTM) disease and tuberculosis (TB) in gold miners were identified in a retrospective case-control study that included 206 NTM patients and 381 TB patients of known human immunodeficiency virus (HIV) status diagnosed between 1993 and 1996. A total of 180 HIV-tested trauma/surgical inpatients were selected as control patients. Both HIV infection (odds ratio [OR] 3.6 for NTM and 4.5 for TB patients) and higher grades of silicosis (OR 5.0 for NTM and 4.9 for TB patients) were significantly more common in NTM and TB patients than in control patients. HIV prevalence rose in the control and both case groups during the study period. The overall HIV prevalence was 13.1% in NTM patients, 14.2% in TB patients, and 5.6% in control patients. Previous TB (OR 9.6), premorbid focal radiological scarring (OR 7.4) and a dusty job at diagnosis (OR 2.4) were additional significant risk factors for NTM disease. These findings suggest that the historically high incidence of NTM disease in miners is largely attributable to chronic chest disease from silica dust inhalation and prior TB. HIV infection has recently become an additional risk factor for mycobacterial disease in miners and is likely to become increasingly important as the HIV epidemic progresses.

Adult↗
PubMed1999

The impact of HIV infection on Mycobacterium kansasii disease in South African gold miners.

The impact of human immunodeficiency virus (HIV) infection on Mycobacterium kansasii disease in miners was investigated with a retrospective study covering a single workforce. M. kansasii, isolated from 43 HIV-positive and 202 HIV-negative miners, was the most common nontuberculous mycobacterial (NTM) species in both HIV groups. CD4 counts were unusually high for M. kansasii disease (mean 490 x 10(6)/L, from 14 HIV-positive men). Treatment outcomes were similar: mortality during treatment was higher in HIV-positive than in HIV-negative men (9% and 2%, respectively), but not significantly so. The majority of a sample of 31 HIV-positive and 92 HIV-negative men had radiological silicosis and/or old tuberculosis scarring prior to M. kansasii disease. A normal premorbid radiograph was more common in HIV-positive men (45% versus 24%; odds ratio [OR], 2.62; 95% confidence interval [95% CI], 1.01 to 6.67). New cavitation was less common (55% versus 78%; OR, 0.34; 95% CI, 0.13 to 0.88) and new hilar adenopathy more common (OR, 5.07; 95% CI, 1.24 to 21.9) in HIV-positive than in HIV-negative men. Miners, who have additional NTM risk factors, develop M. kansasii disease that occurs at an earlier stage of HIV infection and more closely resembles disease in HIV-negative men than has been found for HIV-associated M. kansasii disease in other settings.

AIDS-Related Opportunistic Infections↗
PubMed1999

Noninvasive positive pressure ventilation: successful outcome in patients with acute lung injury/ARDS.

BACKGROUND: There is increasing support for the use of noninvasive positive pressure ventilation (NPPV) in the treatment of patients with acute respiratory failure. Highest success rates are recorded in patients with exacerbation of COPD, particularly in patients presenting primarily with hypercarbic respiratory failure. Success has been more limited in patients with acute hypoxemic respiratory failure, and there are few reports of NPPV in patients with acute lung injury (ALI) or ARDS. OBJECTIVES: We report the outcome of 12 episodes of ALI/ARDS in 10 patients treated with NPPV. DESIGN: Experiential cohort study. SETTING: Tertiary referral center and university hospital ICU. INTERVENTION: Provision of NPPV in patients with ALI/ARDS. RESULTS: Group median (range) APACHE (acute physiology and chronic health evaluation) II score was 16 (11 to 29). Success rate (avoidance of intubation and no further assisted ventilation for 72 h) was achieved on six of nine occasions (66%) when NPPV was used as the initial mode of assisted ventilation. It failed after three episodes of planned (1) or self (2) extubation. Duration of successful NPPV was 64.5 h (23.5 to 80.5 h) with ICU discharge in the next 24 to 48 h for three of six patients. Unsuccessful episodes lasted 7.3 h (0.1 to 116 h) with need for conventional ventilation for an additional 5 days (2.7 to 14 days). Survival (ICU and hospital) for the 10 patients was 70%. CONCLUSIONS: In a group of hemodynamically stable patients with severe ALI, NPPV had a high success rate. NPPV should be considered as a treatment option for patients in stable condition in the early phase of ALI/ARDS.

APACHE↗