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Biomedical subjects

Y Young

Publications and source records attributed to Y Young.

At least 37 records · Page 2Linked to original sources

Living related small bowel transplantation: anaesthesia and peri-operative care.

The peri-operative management of the only surviving case, to date, of living-related small bowel transplantation is described. The anaesthetic technique was chosen to optimize hepato-splanchnic blood flow. Peri-operative splanchnic blood flow was measured and alterations in flow with changes in inotropic agents and volume loading monitored. There appears to be a role for the use of dopexamine and aggressive volume loading.

Adult↗

Effects of desflurane and isoflurane on splanchnic microcirculation during major surgery.

Isoflurane has been considered the agent of choice where preservation of splanchnic blood flow is required. Liver blood flow and the hepatic artery buffer response are maintained better in the presence of isoflurane than with other volatile anaesthetic agents. The effects of desflurane have not been assessed in humans. Therefore, we have compared the effects of isoflurane and desflurane anaesthesia on small bowel and hepatic microcirculatory flow during major surgery using laser Doppler flowmetry in a prospective, randomized, single-blind, crossover study. Patients were allocated randomly to receive desflurane or isoflurane (1 MAC) in oxygen-enriched air. Steady-state jejunal and liver blood flow in segment III were assessed by laser Doppler flowmetry. Volatile anaesthetics were then interchanged, and measurements repeated at steady state. Desflurane anaesthesia at 1 MAC was associated with significantly greater gut blood flow than 1 MAC of isoflurane. These differences could not be explained by systemic haemodynamic differences. The similarity in total hepatic flow between groups implies an intact hepatic artery buffer response with desflurane and isoflurane.

Abdomen↗

Continuing medical education: the question of evaluation.

This paper examines the question of evaluation which has been largely neglected in the credit-based systems of continuing medical education adopted by the Medical Royal Colleges. These systems are seen to encourage a training model of continuing education and a scientific model of evaluation as measurement. By contrast, humanistic evaluation is interpretative and differs not only in its criteria and methods, but also in its underpinning curricular ideologies and values. This model has closer links with concepts of education and professional practice associated with continuing professional development. Decisions about who should conduct the evaluation, what is to be evaluated, how it should be carried out, and about the goals and purposes of evaluation are outlined, noting that they presuppose an ideological view of the relationship of professional knowledge, values and practice. In a concluding discussion of evaluation and the control of professional knowledge, it is argued that the narrow, professional control of evaluation, buttressed by the quality assurance and monitoring mechanisms of the Colleges, is inappropriate, given the increasingly diverse accountabilities which affect medical professionals.

Education, Medical, Continuing↗

A longitudinal examination of functional recovery among older people with subcapital hip fractures.

OBJECTIVE: Few studies have examined the time-dependent change in functional recovery along with the factors that affect the change among older hip fracture patients. The focus of this study is to examine the predictors of functional recovery in community-dwelling older people with subcapital fractures using longitudinal data analysis methods. DESIGN: A 1-year prospective study. Information was obtained through structured interviews following surgery and at 2, 6, and 12 months after hospital discharge and from medical chart review. SETTING AND PATIENTS: The sample consisted of 312 community-dwelling older adults, admitted to one of the seven Baltimore area hospitals with a subcapital fracture, who received either internal fixation or hemiarthroplasty. RESULTS: The longitudinal data analysis using mixed-effects regression indicates that time and prefracture physical activities of daily living (PADL) had a significant association with PADL functional recovery over the course of 1 year. Among those 85 years and older, those who were disoriented after surgery had poorer PADL functional recovery over time than those who were not disoriented. Also, recovery in instrumental activities of daily living (IADL) was associated significantly with time, prefracture IADL function, unsteady gait prefracture, hospital length of stay, and discharge to an institution. The type of surgical procedure performed was not associated significantly with either PADL or IADL functional recovery. CONCLUSIONS: The factors that are related to functional recovery in this study shed light on the complexity of the recovery process in hip fracture patients. The rate of recovery in postsurgical PADL and IADL function is not constant over time; postsurgical IADL function among disoriented patients (without dementia) continues to deteriorate over time compared with the nondisoriented group; this difference in trends of deterioration on IADL function is most profound in the oldest-old aged group, those 85 and older. The types of surgical procedure performed was not significantly associated with postsurgical functional recovery.

Activities of Daily Living↗

Continuing education for medical professionals: a reflective model.

The Royal Colleges and their Faculties have moved continuing professional development up the agenda of doctors in the UK. The low educational value and failure to change professional practice of much continuing medical education has led to criticism of its emphasis on formal, didactic teaching and academic knowledge. The ubiquitous scientific or technical bias in medical education makes questionable assumptions about the nature of professional knowledge, how professionals learn, and the linkage of theory and practice in professional work. Given its narrow conception of professional knowledge, it is hardly surprising that the effectiveness of continuing medical education has proven difficult to evaluate. These points of criticism suggest that a more systematic and coherent approach to continuing education is required. The adoption of the concept of continuing professional development, which draws on learning by reflective practice, marks an important step in this direction. Continuing professional development emphasises self-directed learning, professional self-awareness, learning developed in context, multidisciplinary and multilevel collaboration, the learning needs of individuals and their organisations, and an inquiry-based concept of professionalism. It also involves a widening of accountability to patients, the community, managers and policymakers, and a form of evaluation which is internal, participatory and collaborative rather than external and scientific in character.

Clinical Competence↗

Glial cell line-derived neurotrophic factor: selective reduction of the intermolecular disulfide linkage and characterization of its disulfide structure.

Glial cell line-derived neurotrophic factor is a protein known to enhance the survival of dopaminergic neurons against several neurotoxins. It has been shown to have therapeutic potential in the treatment of Parkinson's disease and other neurodegenerative diseases. We have determined the inter- and intramolecular disulfide linkages of the dimeric molecule by a combination of direct peptide analysis and peptide analysis after either partial reduction or partial oxidation of the protein. Under an acidic condition, the interchain disulfide bond was selectively cleaved with tris(2-carboxyethyl)phosphine, revealing that Cys101 was involved in the intermolecular disulfide linkage. Three other disulfides, Cys68-Cys131, Cys72-Cys133, and Cys41-Cys102, were identified as intramolecular linkages. The determined disulfide structure is highly homologous to that of transforming growth factor beta 2. Since one intramolecular disulfide points through a ring consisting of eight amino acid residues based on the similarity with transforming growth factor beta 2, the disulfide-linked peptides were not purified by conventional methods. Only the peptides from an N-terminal region (residues -1 to 37) were liberated by proteolytic treatment with trypsin or endoproteinase Lys-C, resulting in a stable cystine-knot protein.

Amino Acid Sequence↗

Prevention of falls in the elderly.

The purpose of these symposium presentations was to examine the role of physical activity as a means of preventing hip fractures through the prevention of falls. Risk factor identification is necessary to develop preventive strategies. Risk factors related to physical activity and other risk factors for falls were identified. Intervention studies aimed at reducing, preventing or delaying falls were identified and discussed. A literature search from 1976-1994, identified 52 studies examining risk factors for falls, recurrent falls and/or falls resulting in injury. Nine intervention studies were identified with the primary outcome of falls. Physical activity-related risk factors for falls include limitations in general functioning, such as ambulation and mobility problems, difficulty or dependence in activities of daily living, and exposures to the risks of falling as indicated by the nature and frequency of daily activities. Impairments in gait and balance as well as neuromuscular and musculoskeletal impairments frequently underlie changes in physical activity in old age. Reduced activity level may occur as a result of these impairments, leading to further declines in physical functioning and an increased risk of falls. A relatively high level of activity in old age is also associated with risk of falls. Other risk factors for falls, such as cognitive impairment, visual deficits and medication use, may combine with physical activity-related risk factors to increase the risk of falls. Intervention studies directed at nursing home populations did not prevent falls but had other statistically and clinically significant outcomes. Studies among the community dwelling that targeted potential or current risk factors and included an exercise component reported a significant reduction in falls, prevented the onset of new disabilities and reduced baseline risk factors. Prevention of falls and subsequent injuries in the institutionalized population remains a challenge. Further development of interventions for community-dwelling elders that facilitate maintenance of physical activity without unduly increasing the risk of falls is also critical. The potential for maintenance of benefits gained from all fall interventions needs further examination.

Accidental Falls↗

The predictors of surgical procedure and the effects on functional recovery in elderly with subcapital fractures.

BACKGROUND: It has been demonstrated that the majority of hip fracture patients do not regain their prefracture level of functioning and usually decline in function following fracture. Little is known about the effectiveness of surgical procedure performed (hemiarthroplasty vs internal fixation) on functional recovery of subcapital fracture patients. This study examines the factors related to the type of the surgical procedure chosen and the effect of this selection on physical activities of daily living (PADL) and instrumental activities of daily living (IADL). METHODS: The sample consists of 312 patients with subcapital fractures age 65 and older admitted from the community to one of seven Baltimore area hospitals between 1984 and 1986. Baseline information was obtained during hospitalization through structured interviews with both patients and their significant others (proxy). The follow-up interviews were administered to proxies at two months, six months, and one year after discharge from hospital. Information on disease diagnoses, fracture severity, and surgical procedures performed was obtained from medical charts. RESULTS: Patients with a displaced fracture were seven times more likely to receive a hemiarthroplasty (OR = 7.0, 95% CI 3.7-13.1). During the short-term recovery (2 months after surgery), patients who received hemiarthroplasty were doing better in transferring, meal preparation, and shopping than those who received internal fixation. For the long-term functional recovery (one year), the overall PADL and IADL functions were not statistically significantly different between the two surgical procedures performed. CONCLUSIONS: The severity of fracture was found to be the most important determinant of surgical procedure. Patients with a subcapital fracture who received hemiarthroplasty tended to have a better functional recovery in the short term. Further study of other benefits of using as hemiarthroplasty is needed.

Activities of Daily Living↗

Continuing education for public health medicine--is it just another paper exercise?

In 1993 the Conference of Royal Colleges and their Faculties called for its members to develop formalized continuing medical education (CME) programmes. Most colleges have adopted a narrow definition of CME and a mechanistic approach to monitoring participation. The Faculty of Public Health Medicine has responded differently by initiating a broader model of continuing professional development (CPD) which emphasizes the individual nature of continuing education. This paper explores the rationale behind this decision. Recent systematic reviews of the effectiveness of CME have demonstrated the need for relevance in any continuing education activity. This means relevance not only to learning needs but also to current work and the applicability of the knowledge. However, the effectiveness of traditional CME for all doctors and particularly public health physicians remains to be established. Thus the Faculty has moved towards a wider context of learning in the form of CPD incorporating an evaluative approach and aspects of adult learning theory. There remains a need for the links between audit and continuing education to be strengthened.

Adult↗

New horizons in ICU sedation: exploring non-sedative effects of ICU sedation.

Sedative drugs are widely used in intensive care, primarily in ventilated patients. The common actions and side-effects of these agents are widely recognised. However, recent evidence suggests that opiates and other sedative agents that are used in this situation also have important, but not widely appreciated, effects on metabolism, physiological signalling and disease mechanisms. Some of these effects are an extension of their expected therapeutic actions; these are being elucidated as the biological consequences of stress, and its suppression is now being clarified. An example is the central effects of benzodiazepines and opioids on metabolism and immune function. In other instances these drugs have important peripheral actions, with immunomodulatory or metabolic roles. Furthermore, some drugs may modify disease processes--an example being the antioxidant effect of propofol. Finally, basic cellular mechanisms, such as immediate early gene expression and transcription factor activation, may involve processes that may be susceptible to modification by sedative agents. Such secondary effects of sedative agents need to be investigated for three reasons. First, they provide explanations for some phenomena observed during their use. Second, some of the undesirable side-effects may be avoided by judicious use of drugs in certain clinical situations. Finally, there is the prospect that we may be able to harness some actions for novel therapeutic purposes.

Adrenal Glands↗

Immunoglobulin-A detection and the investigation of clinical toxoplasmosis.

Current serological methods for the investigation of Toxoplasma gondii infection are unreliable for the diagnosis of congenital disease, reactivated infection associated with the acquired immune deficiency syndrome (AIDS), or the determination of the date of onset of infection. An enzyme-linked immunosorbent assay (ELISA) and an immunosorbent agglutination assay (ISAGA) were developed for the detection of toxoplasma-specific immunoglobulin-A (IgA) and used to investigate patients in these three categories. The IgA ISAGA and IgA ELISA were found to be reproducible and specific tests. The IgA ISAGA demonstrated enhanced sensitivity. Measurement of IgA in patients with toxoplasma-associated lymphadenopathy of known duration and AIDS patients with toxoplasma infection was of limited value. Detection of specific IgA by ISAGA was more sensitive than conventional methods for the diagnosis of congenital toxoplasmosis. We recommend the investigation of infant sera with IgA ISAGA. IgA estimation is not indicated in other clinical situations.

Acquired Immunodeficiency Syndrome↗

Endotoxin, septic shock and acute lung injury: neutrophils, macrophages and inflammatory mediators.

The treatment of septic shock remains a major problem in surgical practice. Current research on the pathogenesis of the sepsis syndrome focuses on the effects of the lipopolysaccharide constituents of bacterial endotoxin. Evidence suggests that endotoxin induces a whole-body inflammatory response that in turn mediates organ damage, eventually leading to multiorgan failure. The first organ in which failure is usually apparent is the lung, with the appearance of non-cardiogenic pulmonary oedema as part of the adult respiratory distress syndrome. Inflammatory cells involved in lung injury include neutrophils and macrophages, which release mediators such as elastase, oxygen radicals and cytokines. This review summarizes current experimental work on how endotoxin leads to lung injury, based on its effects in animals and patients. Present knowledge suggests that future treatment of septic shock might involve inhibiting the body's inflammatory response to endotoxin. Possible ways of doing this are discussed.

Endotoxins↗

Transmission of toxoplasmosis by bone marrow transplant associated with Campath-1G.

A 12-year-old boy in third remission acute lymphoblastic leukaemia was given a mismatched transplant from his mother. He suffered prolonged neutropenia and pyrexia which was only finally diagnosed as toxoplasmosis using molecular biology methods and by his response to appropriate treatment. This was probably transmitted by bone marrow transplant since maternal immune T cells were removed by the use of Campath-1G and treatment with cyclosporin A probably prevented his IgM immune response and impeded the diagnosis.

Antigens, CD↗