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Biomedical subjects

A Williams

Publications and source records attributed to A Williams.

At least 451 records · Page 25Linked to original sources
PubMed1991

Is the QALY a technical solution to a political problem? Of course not!

Carr-Hill's critique of health economists' work on QALYs is based on a fundamental misconception about the role, nature, and purpose of policy analysis. Because he fails to distinguish analysis from decision-making, he is led to believe that, in pressing hard to make decision-criteria explicit and transparent, health economists are trying to usurp the decision-makers' role by insisting that the analysts' views replace the decision-makers' views. He believes that this is both naive and dangerous--and, if he were right, it certainly would be. But the truth is that the cause of democratic accountability is better served by relentless analysis designed to make explicit what might otherwise remain hidden, than by leaving the tough problems encountered in priority-setting to be sorted out in forums in which the decisive factors remain obscure.

Decision Making↗
PubMed1991

An audit of the clinical use of magnetic resonance imaging of the head and spine.

An audit was undertaken of the use of magnetic resonance imaging for clinical problems of the head and spine. Using a form of simulation, two consultant clinicians were asked to assess a sequential series of 200 patients referred for magnetic resonance. The clinicians considered that 200 magnetic resonance studies could replace about 330 other imaging and neurophysiology investigations; the cost of the alternative tests approximated the cost of magnetic resonance. However, there was considerable variation between cases in the costs of investigations potentially replaced by the procedure under audit, and this variation suggests ways in which magnetic resonance might be used more cost-effectively in the future.

Brain↗
PubMed1991

Differences in the attitudes of men and women practitioners to responsibility and competence.

A study has been carried out to predict the prescribing and referral behaviour of general practitioners by measuring their attitudes to their roles. Part of this study involved determining whether women doctors accept greater responsibility and feel more competent than men when undertaking those tasks for which they are said to be suited. In May 1987 a postal questionnaire was sent to all 525 general practitioners in contract with Avon family practitioner committee. Replies from 82 women and 289 men showed that women accepted more responsibility for sex-related tasks. For other medical tasks, including those of a technical and traditional nature, men accepted both more responsibility and felt more competent than did women respondents. Contrary to expectations, women did not accept more responsibility or feel more competent than men for psychosocial tasks. The results are discussed in the context of the role of women within medicine.

Attitude of Health Personnel↗
PubMed1991

Board certification and practice style: an analysis of office-based care.

BACKGROUND: The relationship between family practice certification and practice style has important health policy implications. We used data from the RAND Health Insurance Experiment to study the relationship between family practice certification and (1) patient characteristics including age and sex of patients, and (2) facets of practice style including probability of hospital admission, number of visits in an episode of care, number of physicians seen per episode, total charges per episode, charges per service category, and inputs per service category. METHODS: Data on health care service utilization by a sample of 5554 nonelderly individuals over a 1-year period were used to define episodes of care. Multivariate regression techniques were used to measure the association between family practice certification and patient characteristics and between family practice certification and practice style, controlling for the effects of patients characteristics. RESULTS: Patients of certified family physicians were an average of 3 years younger than patients of noncertified family physicians, but other demographic characteristics were similar. Certified family physicians had higher pathology services charges and inputs, but no statistically significant differences in other measures of charges and inputs. CONCLUSIONS: Certified and noncertified family physicians treat similar patients. Certification in family practice is not associated with major differences in total service charges, but is associated with differences in the use of laboratory diagnostic services.

Adolescent↗
PubMed1991

The evaluation of patients with human immunodeficiency virus-related disorders and brain mass lesions.

In patients at risk for acquired immunodeficiency syndrome who present with a mass lesion, a dilemma arises as to whether to treat empirically for toxoplasmosis or perform a brain biopsy. We present data that further define the indications for performing brain biopsy vs empiric treatment. We reviewed charts on 59 patients with acquired immunodeficiency syndrome--related disorders and cerebral mass lesions. Thirty-two patients met diagnostic criteria for toxoplasmosis. Bayesian analysis demonstrated that the prior probability of toxoplasmosis was increased by the presence of contrast enhancement on computed tomographic scans (0.68) and toxoplasmosis titers greater than 1:64 (0.81). Features associated with decreasing probabilities of toxoplasmosis included the absence of contrast enhancement on computed tomographic scans (0.29) and toxoplasmosis titers less than or equal to 1:64 (0.14). Ten percent of patients had complications of brain biopsy. Treatment with pyrimethamine and sulfadiazine produced complications in 29% and serious complications in 8% of treated patients. These data favor empiric therapy for patients with typical features of toxoplasmosis and brain biopsy for defined subsets of patients with atypical features.

Bayes Theorem↗
PubMed1990

Grampian Health Board's joint drug formulary.

OBJECTIVE: To develop a model for creating a joint general practice-hospital formulary, using the example of ulcer healing drugs. DESIGN: A joint formulary development group produced draft guidelines based on an earlier hospital formulary, which were sent to interested local general practitioners for consultation. Revised guidelines were then drawn up and forwarded to the health board's medicines committee for approval and distribution. SETTING: Grampian Health Board. SUBJECTS: Nine members of joint formulary development group plus local general practitioners who were invited to comment on a list of 11 ulcer healing drugs. MAIN OUTCOME MEASURE: Degree of coincidence of drugs selected by hospital doctors and general practitioners. RESULTS: The ulcer healing drugs selected by the panel of general practitioners and by hospital doctors were highly coincident. The cost of one day's treatment with drugs varied considerably between hospital and general practice--for example, one drug cost 46p in hospital and 1 pounds in general practice and another cost 1.26 pounds in hospital and 1.01 pounds in general practice. Overall, six drugs cost more in hospital and five cost more in general practice. CONCLUSIONS: A joint formulary for use in hospitals and general practice in a health board can be devised fairly simply by consultation as virtually the same drugs are used in both types of practice. It should influence the health board's expenditure on drugs and affect the choice of drugs when a patient is discharged from hospital or is referred to any hospital in the region.

Anti-Ulcer Agents↗
PubMed1990

Evidence for conformers of rabbit muscle adenylate kinase.

Changes of the apparent Mr values and the circular dichroism patterns suggest the existence of three relatively stable conformers of rabbit muscle adenylate kinase (RMAK). The effects of dithiothreitol (DTT) which stimulates activity, pH, the substrates, and ATP on the Mr value and the Stokes radius of RMAK were determined from gel filtration data, and apparent Mr values near 22,000, 26,000, and 29,000 resulted. Substrates generated multiple Mr values, suggesting the presence of multiple conformers of RMAK. The higher apparent Mr values were obtained in the presence of DTT and at the higher substrate concentrations, indicating more open conformations. The effect of the substrates on the conformation of RMAK is discussed in relation to the kinetic mechanism of this random bireactant system. Circular dichroism studies were undertaken in order to observe any changes in the secondary structures of RMAK in relation to changes of the Mr values. The secondary structure composition of RMAK, determined under our conditions, does not agree with results determined from crystallographic studies. The gel filtration and the CD studies suggest that above pH 7 a more open conformation of RMAK obtains in the presence of DTT. The results of these studies are discussed with reference to the location of the active sites.

Adenylate Kinase↗
PubMed1990

Alloimmunization in sickle cell anemia and transfusion of racially unmatched blood.

Transfusion therapy for sickle cell anemia is limited by the development of antibodies to foreign red cells. To evaluate the frequency and risk factors associated with such alloimmunization, we determined the transfusion history, red-cell phenotype, and development of alloantibodies in 107 black patients with sickle cell anemia who received transfusions. We compared the results with those from similar studies in 51 black patients with sickle cell disease who had not received transfusions and in 19 nonblack patients who received transfusions for other forms of chronic anemia. We assessed the effect that racial differences might have on the frequency of alloimmunization by comparing the red-cell phenotypes of patients and blood-bank donors (n = 200, 90 percent white). Although they received transfusions less frequently, 30 percent of the patients with sickle cell anemia became alloimmunized, in contrast to 5 percent of the comparison-group patients with other forms of anemia (P less than 0.001). Of the 32 alloimmunized patients with sickle cell anemia, 17 had multiple antibodies and 14 had delayed transfusion reactions. Antibodies against the K, E, C, and Jkb antigens accounted for 82 percent of the alloantibodies. Comparison of red-cell phenotypes in the three study groups (the patients with sickle cell anemia, the patients with other forms of anemia, and the blood donors) revealed statistically significant differences between the patients with sickle cell anemia and the donors but not between the patients with other forms of anemia and the donors. These differences are most likely racial. We conclude that alloimmunization is a common, clinically serious problem in sickle cell anemia and that it is partly due to racial differences between the blood-donor and recipient populations.

Adolescent↗
PubMed1990

Escape the trap.

Explore the source record for details and available documents.

Appointments and Schedules↗
PubMed1990

Disease and symptom severity, functional status, and quality of life in chronic bronchitis and emphysema (CBE).

A path analysis model examined interrelationships among variables significantly associated with chronic dyspnea in chronic bronchitis and emphysema (CBE) and the relative influence of these variables on each other and on functional status and quality of life. Results from the 45 adults (mean age, 61) with moderate CBE disease severity showed that dyspnea severity has a sizable effect on functional status and quality of life. Disease severity was more strongly related to functional status than to quality of life. Depression and mastery had the strongest total effects on quality of life. Dyspnea severity had strong but separate effects on functional status and quality of life. From these preliminary results, it is suggested that a direct focus on psychologic interventions to ameliorate depression and improve mastery is likely to improve quality of life with some resultant positive effect on functional status.

Adaptation, Psychological↗
PubMed1990

Gastro-oesophageal reflux and apnoeic pauses during sleep in infancy--no direct relation.

We studied the relation of gastro-oesophageal reflux with apnoea during sleep in 24 infants with antecedent respiratory abnormalities and/or proven gastrooesophageal reflux (GOR), by combined lower oesophageal pH and polygraphic monitoring. GOR, indicated by pH less than 4, was confirmed in 24 infants. There were no episodes of prolonged (greater than 20 s) central apnoea (CA). Fifty-six mixed or obstructive breathing episodes were identified in 12 infants (14 studies), of which 28 lasted between 3 and 6 s. Bradycardia (heart rate less than less than 80 beats/min for 10 s was not observed. There were 80 falls in transcutaneous oxygen (PtcO2 greater than 5 mmHg) but only 6 exceeded 10 mmHg and one 20 mmHg. There was no relationship between GOR and obstructive episodes in terms of frequency, duration or temporal occurrence, except in one infant. There were 1276 gross body movements, mainly during active or indeterminate sleep and, of these, 7% were associated with decreases in pH to less than 4. Movements occurred during the 60 s period preceding 83% of pH decreases greater than 1 pH unit compared to only 30% in the 60 s succeeding a pH drop. We conclude that, while GOR and obstructive episodes may co-exist in the patient groups studied, decreases in pH in the lower oesophagus do not usually induce either central or obstructive apnoea, and vice versa. Of the variables monitored, only gross body movements were temporally associated with pH drops, and usually preceded them.

Blood Gas Monitoring, Transcutaneous↗
PubMed1990

Three new species of Monocotyle (Monogenea: Monocotylidae) from the stingray, Himantura uarnak (Rajiformes: Dasyatidae) from the Great Barrier Reef: phylogenetic reconstruction, systematics and emended diagnoses.

Three new species of Monocotyle were found on the gills of the coachwhip stingray, Himantura uarnak (Rajiformes: Dasyatidae) collected at Heron Island, Great Barrier Reef, Australia (23 degrees 27' S, 151 degrees 55 'E). Monocotyle helicophallus new species, Monocotyle multiparous new species and Monocotyle spiremae new species all have a single testis and are distinguished from other described Monocotyle species by size of body and hamulus and number of coils of the sclerotized male copulatory organ (21-22, three to four and 29-42, respectively). Monocotyle helicophallus new species is characterized by several muscular genital papillae, one of which is traversed by the ejaculatory duct; M. spiremae new species is distinguished by a sclerotized accessory structure associated with the distal end of the male copulatory organ, a vaginal sclerite and a conspicuous spherical, ejaculatory bulb; M. multiparous new species is distinguished by a large number of retained, thin-shelled eggs, many of which contain a fully developed oncomiracidium. A phylogenetic analysis of the 14 described species of Monocotyle utilizing 13 characters (11 binary and two multistate) produced the most parsimonious cladogram involving 18 steps with a consistency index of 0.78, two homoplasies and four unresolved polychotomies. Emended diagnoses of the Monocotylinae and Monocotyle are provided.

Animals↗
PubMed1990

The subcutaneous attachment of the monogenean Heterobothrium elongatum (Diclidophoridae) in the gills of Torquigener pleurogramma (Pisces: Tetraodontidae).

Heterobothrium elongatum predominantly occurred on the most anterior pair of gill arches of infected pufferfish, Torquigener pleurogramma. Juvenile and immature stages attached to gill lamellae and were concentrated on the ventral regions of the anterior pair of gill arches. Following penetration of subcutaneous tissues, young adult worms formed a subcutaneous channel either directly above or below the transverse septum, a tissue layer connecting the bases of adjacent gill rays. Large, sexually mature worms extended for most or all of the length of the gill arch where they filled the area normally occupied by the longitudinal lymphatic vessel (branchial vein) or lay adjacent to the efferent branchial and colateral arteries. Subcutaneous attachment by the parasite induced a marked inflammatory reaction in the host. During growth, the mid-region of the parasite became markedly elongate and formed a stalk connecting the haptor lying in the dorsal region of the gill and the body which emerged from the lower margin of the gill where penetration began.

Animals↗