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Biomedical subjects

M Rafferty

Publications and source records attributed to M Rafferty.

At least 19 recordsLinked to original sources
PubMed2000

An open-label study of the role of adjuvant hemostatic support with protein C replacement therapy in purpura fulminans-associated meningococcemia.

Activated protein C (APC) is a natural anticoagulant that plays a pivotal role in coagulation homeostasis. Severe inherited or acquired deficiency results in a clinical syndrome called purpura fulminans. In addition, APC also appears to have potent cytokine-modifying properties and is protective in animal models of sepsis. The dual functional properties of APC are particularly relevant to severe meningococcemia, where acquired PC deficiency is accompanied by multiorgan failure and purpura fulminans. The authors conducted an open-label prospective study assessing the efficacy of PC replacement therapy in patients with severe meningococcal septicemia, purpura fulminans, and multiorgan failure. The morbidity and mortality were compared with predicted morbidity using the Glasgow Meningococcal Septicemia Prognostic Score. Thirty-six patients with a mean age of 12 years (range 3 months to 72 years) were enrolled in the study. The mean +/- SD for plasma PC was 18 +/- 7 IU/mL. PC was significantly lower than antithrombin or protein S and was also significantly lower than PC levels in a cohort of patients who developed meningococcemia without multiorgan failure and purpura fulminans. A total of 3 of 36 (8%) patients died, which compares favorably with predicted mortality of 18 of 36 (50%). Amputations were required in 4 of 33 (12%) survivors and in 2 of 31 (6.5%) patients who received PC within 24 hours of admission into the hospital, in comparison with the predicted amputation rate of 11 of 33 (30%). In conclusion, PC replacement therapy in severe meningococcal septicemia was associated with a reduction in predicted morbidity and mortality. The beneficial effect of PC replacement may reflect both the anticoagulant and anti-inflammatory properties of the PC pathway. (Blood. 2000;96:3719-3724)

Adolescent↗
PubMed1999

Nerve monitoring in thyroid surgery: is it worthwhile?

This study analysed the use of the commercially available Neurosign 100(R) Nerve Monitor during thyroidectomy. Consecutive patients undergoing thyroidectomy were monitored. The nerve response prior to and after thyroidectomy were compared as were the relative benefits of mono and bipolar electrodes. Twenty-one consecutive patients over 9 months were assessed. The threshold for stimulation of the recurrent laryngeal nerve was never more than 0.5 mA (range 0.2-0.5 mA) for the bipolar and 1.5 mA (range 0.2-1.5 mA) for the unipolar electrode. The threshold for the superior laryngeal nerve was 1 mA and 1.5 mA, respectively. Following resection, stimulation levels of the laryngeal nerves were unchanged. Use of the Neurosign 100 Nerve Monitor is helpful in laryngeal nerve localization and confirmation. The bipolar electrode set at 30 Hz. and 0.5 mA for the recurrent laryngeal nerve and 1.0 mA for the superior laryngeal nerve is recommended. Threshold comparison before and after resection would appear to have a prognostic value.

Adult↗
PubMed1999

The effect of ventilation tubes on stresses and vibration motion in the tympanic membrane: a finite element analysis.

Finite element analysis is used to determine the mechanical behaviour of structures. The deformation of a structure caused by a force can be calculated, and the stresses and strains within the component can be found. In brief, a geometric representation-a 'drawing'-of the structure is loaded into a computer, and a component is divided into 'elements' which usually have the shape of 'bricks'. A common analogy is a 'lego' brick assembly. The deformation of an element can be determined using engineering formulae, and the deformation of the whole structure can be determined when the elements are re-asssembled. There have been very few analyses of the biomechanical behaviour of ventilation tubes, or grommets, even though clinical studies have indicated that tube design and material determines extrusion rates and may influence tympanosclerosis. This paper reports a comprehensive biomechanical analysis of the effect of a grommet on the tympanic membrane. Analytical and computer simulation techniques (finite element analysis) are used to determine the changes in the vibratory motion and stresses in the membrane when a Reuter-Bobbin ventilation tube is inserted. It is found that the presence of a ventilation tube significantly affects the motion of the membrane in the neighbourhood of the implant. When the effect of implant material is investigated, it is found that the amplitude of motion of a heavier metal implant is less than a lighter polymeric implant. If it is true that higher motion predisposes towards early extrusion, then the lighter implant (polyethylene) is predicted to have a higher extrusion rate. Regarding the maximum stresses in the tympanic membrane, they form a crescent-shaped region in the anterior and posterior quadrants in the regions where tympoansclerosis is observed. The magnitude and pattern of the stress is predicted not to depend significantly on the presence of the tube. This suggests that tympanosclerosis is not determined by the implant per se and therefore that no tube design feature can be expected to prevent it.

Computer Simulation↗
PubMed1998

Nucleolin promotes homologous DNA pairing in vitro.

We purified to near homogeneity a previously identified 100 kDa mammalian homologous DNA pairing protein. The purified 100 kDa protein also catalyzed high levels of cell-free homologous DNA recombination activity. This ATP-dependent activity was capable of forming conservative recombinant products between two circular, double-stranded DNA molecules. We were unable to detect any DNA polymerase, DNA ligase, or 5' or 3' exonuclease activity associated with this purified material. The purified 100 kDa protein bound silver nitrate as well as a monoclonal antibody specific for nucleolin. A recombinant protein comprised of the Escherichia coli maltos-ebinding protein fused to the carboxyl-terminal two-thirds of human nucleolin possessed homologous DNA pairing activity. These data indicate that the 100 kDa homologous DNA pairing protein is nucleolin. The observation that nucleolin can carry out homologous DNA strand pairing in vitro raises the prospect that it may function similarly in vivo.

Base Pairing↗
PubMed1998

Prevention services in primary care: taking time, setting priorities.

Preventive services are delivered at rates far below recommended levels. Although lack of time has frequently been cited as an important factor, little is known about how much time primary care clinicians devote to prevention and how they prioritize that time. Work sampling was used to estimate the proportion of time spent on prevention during routine care of patients by primary care clinicians in two hospital-based clinics serving indigent patients. Clinicians were prompted by computer at random intervals to describe their current activity and, if the activity was prevention-related, to choose the specific activity from a list modified from the U.S. Preventive Services Task Force (USPSTF) recommendations. Proportions of time spent on prevention overall and by specific prevention activity were calculated, and the association between USPSTF ratings of specific prevention activities and proportion of time spent on those activities was examined using Kendall's Tau. Clinicians in these clinics spent just 11% of their time on prevention, or about 7 minutes per patient per year. Screening for just two diseases, breast cancer and cervical cancer, accounted for half of all prevention-related activity. There was no overall relation found between proportion of time by specific prevention activity and USPSTF ratings. Thus, the primary care clinicians spent little time on prevention and did not apportion that time according to USPSTF recommendations. If these results are representative, time constraints in actual practice may be too severe to deliver the full range of preventive services suggested by USPSTF.

Adult↗
PubMed1997

Use of protein-C concentrate, heparin, and haemodiafiltration in meningococcus-induced purpura fulminans.

BACKGROUND: Inflammatory and coagulation processes are both affected in meningococcaemia. Severe acquired protein-C deficiency in meningococcaemia is usually associated with substantial mortality: in survivors, skin grafts, amputation, and end-organ failure are not uncommon. Protein C is a natural anticoagulant and also has important anti-inflammatory activity. We assessed the effects of early replacement therapy with protein-C concentrate together with continuous veno-venous haemodiafiltration and conventional treatment in meningococcaemia. METHODS: 12 patients aged between 3 months and 27 years with meningococcaemia and severe acquired protein-C deficiency (mean 0.20 IU/mL) were studied. All patients had septic shock, widespread purpura, skin necrosis, and disseminated intravascular coagulopathy. After a test dose of protein-C concentrate, patients received a continuous infusion with the dose adjusted daily to keep the plasma concentration between 0.8 and 1.2 IU/mL. 11 patients were given unfractionated intravenous heparin (10-15 IU kg-1 h-1). Nine patients had haemodiafiltration and one had peritoneal dialysis. The Glasgow meningococcal septicaemia prognostic score and the paediatric risk of mortality score predicted a minimum mortality of 80% and 57%, respectively. FINDINGS: No patient died. No adverse reactions to the treatment were seen. Two patients had lower-limb amputations, one of whom had a thrombotic cerebrovascular accident; both patients had received the protein-C concentrate and heparin later than the rest of the group (60 h [16.97] vs 12 h [3.13]). One patient developed chronic renal failure despite receiving protein-C infusion 15 h after admission. INTERPRETATION: The acquired severe deficiency of protein C in meningococcaemia contributes to the pathogenesis of the thrombotic necrotic lesions in the skin and other organs and probably has an important role in the inflammatory response. Protein-C therapy is merely one approach to improve the host response in this syndrome. We suggest that a double-blind, randomised, controlled multicentre trial is needed to confirm our results.

Adolescent↗
PubMed1996

Educating nurses to undertake clinical supervision in practice.

Alongside interest in the process of clinical supervision, there is a growing recognition of the need for education for practitioners undertaking the role of supervisor. This article describes a module accredited by the Welsh National Board and the University of Wales, Swansea, which was designed to achieve this aim and help practitioners design structures for supervision applicable to their practice settings. The structure and content of the module are described, as well as an evaluation of the first intake.

Curriculum↗
PubMed1991

Technology assessment and the evaluation of implanted medical devices.

Technology assessment is attracting new attention and funding as concern about costs and effectiveness of health care grows. This article provides a general overview of technology assessment and relates recent trends and future prospects specifically to the use and evaluation of implanted medical devices. In the next decade we may expect to see renewed interest in technology assessment as pressure to control health care costs continues and as a different focus of evaluation emerges that emphasizes patient preferences and quality of life in addition to traditional measures of safety, efficacy, and cost-effectiveness. These pressures and forces will act to increase the visibility and importance of proper assessment of medical technology, and the field may more nearly achieve its early promise as a tool to make medical care more rational.

Community Participation↗
PubMed1991

The 'Open Road' project: real jobs for people with mental handicap.

This article describes the key elements of a three-year innovative project underway in Dublin, Ireland, which is applying the principles of supported employment. It covers the development of more integrated day services for adults with mental handicap, programme participants and activities, and key issues to be resolved in maintaining effective programmes of this kind.

Adult↗
PubMed1991

Pleural effusion is associated with a poor treatment outcome in stage III small non-cleaved cell lymphoma.

The clinical significance of pleural effusion was assessed in 24 children with unresectable abdominal small non-cleaved cell lymphoma (St. Jude Stage III). Patients were consecutively enrolled and treated on a regimen including high dose fractionated cyclophosphamide and co-ordinated high dose methotrexate and cytarabine. The overall results were excellent, with 20 of 24 patients alive and event-free at a median follow-up of 4 years. Only one of the patients who lacked pleural effusion has relapsed (testicular), even though many had massive disease. In contrast, three of seven patients with pleural effusion have failed treatment (p = 0.02) and subsequently died. Two measures of tumor burden, serum lactic dehydrogenase and, in a subset of patients, interleukin-2-receptor levels, were significantly higher in patients with pleural effusion (p = 0.002 and p = 0.05, respectively). These findings suggest that unresectable abdominal small non-cleaved cell lymphoma associated with pleural effusion should be up-staged and that these patients should receive more intensive chemotherapy.

Abdominal Neoplasms↗
PubMed1990

A comparison of placement techniques and complications of externalized catheters and implantable port use in children with cancer.

The complications associated with the placement and use of Hickman catheters (n = 120), Broviac catheters (n = 146), and implantable ports (n = 93) in children with cancer were analyzed. Percutaneously placed central venous access devices (CVADs) tended to fail less often (P = .86) and to develop infections less often (P = .056) than surgically placed CVADs. The difference in complications with percutaneous versus surgically placed CVADs requires confirmation in a randomized trial to assure they are not a result of differences in patient characteristics. When all catheter failures (removal due to infection, obstruction, or dislodgement) were considered, ports had a significantly longer failure-free duration of use than externalized Hickman and Broviac catheters (P = .0009). Ports also remained infection-free longer than externalized catheters (P = .0014). The greatest risk of infection occurs in the first 100 days of use, particularly for ports. This study demonstrates that for long-term use (greater than 100 days) ports are superior to externalized catheters in children with cancer.

Bacterial Infections↗
PubMed1990

A nursing model for addressing the health needs of homeless families.

Homelessness in the United States continues to be a major social problem directly affecting an estimated three million persons, of whom nearly 30 percent belong to families without permanent shelter. This paper reviews recent research concerning homeless families and the conditions in which they live and outlines the significant health and mental health problems that these families experience. Effective nursing interventions for homeless families using Peszneckers' Model of Poverty are proposed. Nurses must advocate for changes in the social and political conditions that bring about homelessness since the resources to meet the needs of these families are either nonexistent or woefully inadequate.

Child↗
PubMed1989

A prospective study of Hickman/Broviac catheters and implantable ports in pediatric oncology patients.

We prospectively studied the continuous function and complication rates of 286 central venous catheters consecutively placed in 264 children and young adults at a single institution over a 19-month period (median follow-up, 376 days). Externalized catheters (91 Hickman [H], 113 Broviac [B]) and implantable ports (n = 82) were compared for complications, including infection and thrombosis. The most frequent major complication of all catheters was infection, although the rates of infection varied with the duration of catheter use and were generally lower than reported by others. Overall, when catheter failures (removal) for infection, obstruction, or dislodgement were considered, ports had a significantly longer failure-free duration of use (P = .0024) than did externalized catheters. Likewise, ports had a significantly longer infection-free (P less than .01) duration of use than H and B catheters. However, differences in patient age and clinical characteristics among the three catheter groups may have affected the outcome. In analysis of pairs matched for diagnosis, therapy, and age, ports had lower infection rates than did B catheters after 100 days (P = .053). This difference became significant at 400 days of catheter use (P = .029). Although there was a trend toward lower rates of infections for ports v H catheters, this difference was not significant. In view of our results in matched pairs, selection of catheter type based on clinical characteristics and patient preferences remains a reasonable therapeutic approach despite the apparent advantages of ports. The superiority of ports for long-term use (greater than 100 days) needs to be confirmed in a large randomized clinical trial.

Adolescent↗
PubMed1989

A profile of the medically uninsured in Georgia.

The provision of health care to the growing number of persons uninsured against medical expenses affects Georgia doctors, hospitals, and state and local government at all levels. While much is known nationally about the uninsured, there are no good data about this group in Georgia. This study uses U.S. Census Bureau data to provide a demographic profile of Georgians who lack health insurance and to identify groups at particular risk for being uninsured. Approximately 950,000 (17.7%) of non-elderly Georgia residents are uninsured, compared to 37 million (17.6%) in the U.S. as a whole. As is true generally in the U.S., those in Georgia who are poor, young, non-white, and in families with a female head are at greatest risk. Of particular note are the poor in Georgia with incomes from 50% to 100% of the federal poverty level (55.2% uninsured). This population deserves the special attention of all involved in finding a solution to this problem.

Employment↗