Search PubMed⌕ Search

Biomedical subjects

M Ryan

Publications and source records attributed to M Ryan.

At least 55 records · Page 3Linked to original sources
PubMed2000

Comparing different methods of assessing body composition in end-stage renal failure.

BACKGROUND: Accurate measurement of nutritional status in patients with end-stage renal disease is important because of its clear association with prognosis. Total body water (TBW) has additionally been recently recognized as an independent prognostic value because of its relationship with hypertension and cardiac morbidity. The current study was designed to assess the utility of surrogate markers of nutritional state and TBW in patients with end-stage renal disease. METHODS: Fifty-four patients with renal disease were studied. TBW obtained using the deuterium dilution technique was compared with estimates derived from anthropometric measures of TBW, including 58% body weight, Watson equations, and bioelectrical impedance analysis (BIA). Anthropometrically derived fat-free mass (FFM) was compared with BIA-derived estimates. Total body nitrogen (TBN) measurements were correlated with TBW estimates and BIA-derived resistance. RESULTS: TBW was significantly underestimated by the Watson equation (mean difference, -1.751 L, P = 0.01) and the 58% body weight approximation significantly overestimated it (mean difference, 1.792 L, P = 0.04). The Kushner BIA estimation of TBW did not significantly differ from that of the gold standard determined from D2O dilution (mean difference, -1.221 L, P = 0.12) and was also the method that showed the best agreement with the D2O estimate. However, the limits of agreement were large. Accurate prediction equations for FFM (FFM = -21.768 + 0.001 x ht2 + 6630.669 x 1/R + 0.312 x wt, R2 = 0.95) and TBN (TBN = -668.324 - 3.963 x age + 10.133 x wt + 0. 045 x ht2 + 32141.457 x 1/R, R2 = 0.91) were derived from BIA obtained resistance. CONCLUSIONS: The estimation of TBW varies significantly depending on the method of calculation. BIA is the most accurate surrogate marker for the measurement of both TBW and other parameters of body composition.

Adipose Tissue↗
PubMed2000

Pain management: an organizational commitment.

Although much has been done to promote pain assessment and management, pain remains a major, yet largely preventable, public health problem in the United States. A strategy that has been proposed to assure optimal pain management is the development of formal means within institutions to evaluate pain management practices and foster improved outcomes. In response to a pain-related patient care problem, South Nassau Communities Hospital recognized the need to undertake more formal methods for managing patients with acute, chronic, and cancer pain. A Pain Management Task Force was charged with the development of a comprehensive pain management program. Its efforts to date and plans for the future position this institution as ready for the Joint Commission for the Accreditation of Healthcare Organizations' pain assessment and management standards that were introduced in 2000.

Hospitals, Community↗
PubMed2000

Acupressure and prevention of nausea and vomiting during and after spinal anaesthesia for caesarean section.

The efficacy of acupressure at the P6 point in the prevention of nausea and vomiting during and after Caesarean section was studied. A double-blind, randomized controlled study of acupressure vs placebo was designed. Ninety-four patients scheduled for Caesarean section were included. The anaesthetic technique and postoperative analgesia were standardized. The use of acupressure reduced the incidence of nausea or vomiting from 53% to 23% compared with placebo (95% confidence interval (CI) 0.34-0.25; P = 0.002) during the operation and from 66% to 36% compared with placebo (95% CI 0.34-0.19; P = 0.003) after the operation. Other variables were similar between the groups.

Acupressure↗
PubMed2000

Trade-offs between location and waiting times in the provision of health care: the case of elective surgery on the Isle of Wight.

BACKGROUND: Recent UK government documents have stated that, within the National Health Service, consumers should be more involved in decision-making. This study considered the technique of discrete choice conjoint analysis (DCCA) for eliciting community views regarding the importance of reducing waiting times. More specifically, the study aimed to establish whether residents living on the Isle of Wight are prepared to travel to the mainland for elective surgery where waiting times are shorter but travel costs may be greater, and, further, if residents are willing to travel, what reduction in waiting time and increase in travel costs would be acceptable. METHODS: A DCCA questionnaire was sent to a random sample of 1,000 individuals living on the Isle of Wight. RESULTS: Seventy-eight per cent of respondents were willing to travel to the mainland for elective surgery. Of these, 48 per cent always chose the mainland and 30 per cent traded between island and mainland, depending on the levels of waiting time and travel costs. Whereas 'traders' preferred the Isle of Wight, they would forgo their preferred location if waiting times were reduced by at least 3.9 months, and they were willing to pay over 12 for a 1 month reduction in waiting time. Different combinations of waiting time reductions and travel cost increases that were acceptable to traders were estimated. CONCLUSIONS: Carrying out elective surgery on the mainland offers the potential to reduce waiting lists for island residents. The majority of respondents would be willing to travel to the mainland. However, one-fifth of respondents were not willing to travel to the mainland for elective surgery. The preferences of this group are important in policy decisions. More generally, the paper demonstrates the potential application of DCCA to public health issues.

Adolescent↗
PubMed2000

Diabetes and the Mediterranean diet: a beneficial effect of oleic acid on insulin sensitivity, adipocyte glucose transport and endothelium-dependent vasoreactivity.

Abnormalities in endothelial function may be associated with increased cardiovascular risk in diabetic patients. We examined the effect of an oleic-acid-rich diet on insulin resistance and endothelium-dependent vasoreactivity in type 2 diabetes. Eleven type 2 diabetic patients were changed from their usual linoleic-acid-rich diet and treated for 2 months with an oleic-acid-rich diet. Insulin-mediated glucose transport was measured in isolated adipocytes. Fatty acid composition of the adipocyte membranes was determined by gas-liquid chromatography and flow-mediated endothelium-dependent and -independent vasodilatation were measured in the superficial femoral artery at the end of each dietary period. There was a significant increase in oleic acid and a decrease in linoleic acid on the oleic-acid-rich diet (p<0.0001). Diabetic control was not different between the diets, but there was a small but significant decrease in fasting glucose/insulin on the oleic-acid-rich diet. Insulin-stimulated (1 ng/ml) glucose transport was significantly greater on the oleic- acid-rich diet (0.56+/-0.17 vs. 0.29+/-0.14 nmol/10(5) cells/3 min, p<0.0001). Endothelium-dependent flow-mediated vasodilatation (FMD) was significantly greater on the oleic-acid-rich diet (3.90+/-0.97% vs. 6.12+/-1.36% p<0.0001). There was a significant correlation between adipocyte membrane oleic/linoleic acid and insulin-mediated glucose transport (p<0.001) but no relationship between insulin-stimulated glucose transport and change in endothelium-dependent FMD. There was a significant positive correlation between adipocyte membrane oleic/linoleic acid and endothelium-dependent FMD (r=0.61, p<0.001). Change from polyunsaturated to monounsaturated diet in type 2 diabetes reduced insulin resistance and restored endothelium-dependent vasodilatation, suggesting an explanation for the anti-atherogenic benefits of a Mediterranean-type diet.

Adipocytes↗
PubMed2000

The use of conjoint analysis to elicit community preferences in public health research: a case study of hospital services in South Australia.

AIMS: To demonstrate the use of conjoint analysis (CA) in public health research through a survey of the South Australian community about aspects of their public hospital services. METHODS: A series of focus groups determined the most important attributes in choice of hospital services. These were built into a CA survey, using the discrete choice approach. The survey was posted to a representative sample of 700 South Australians. Theoretical validity, internal consistency and non-response bias were all investigated. RESULTS: Some 231 individuals returned the questionnaire. The attribute, 'improvement in complication rates' was positively associated with choice of hospital. Three attributes were found to be negatively associated with such choice: 'waiting times for casualty', 'waiting times for elective surgery' and, anomalously, 'parking and transport facilities'. 'Travel time' and the cost attribute, 'Medicare levy' were not statistically significant. Trade-offs between the significant attributes were estimated, as were satisfaction or utility scores for different ways of providing hospital services. Results concerning internal consistency and internal validity were encouraging, but some potential for non-response bias was detected. CONCLUSION: A high premium is placed on the quality of hospital care and members of the community are prepared to choose between hospitals largely on the basis of outcomes and length of waiting times for elective surgery and in casualty. IMPLICATIONS: CA can yield potentially policy-relevant information about community preferences for health services.

Adult↗
PubMed2000

Renal resistance to vasopressin in poorly controlled type 1 diabetes mellitus.

To investigate the hypothesis that diabetes induces nephrogenic diabetes insipidus, we studied the urine-concentrating ability in response to vasopressin (AVP) in 12 patients with insulin-dependent diabetes mellitus (IDDM) and 12 nondiabetic controls. Subjects were euglycemic-clamped, and after oral water loading, AVP was infused intravenously for 150 min. AVP induced a greater (P<0.001) rise in urine osmolality in controls (67.6+/-10.7 to 720+/-31.1 mosmol/kg, P<0.001) than in IDDM patients (64.3+/-21.6 to 516.7+/-89.3 mosmol/kg, P<0.001). Urinary aquaporin-2 concentrations after AVP infusion were higher in controls (611.8+/-105.6 fmol/mg creatinine) than in IDDM (462.0+/-94.9 fmol/mg creatinine, P = 0. 003). Maximum urine osmolality in IDDM was inversely related to chronic blood glucose control, as indicated by Hb A(Ic) (r = -0.87, P = 0.002). To test the hypothesis that improved glycemic control could reverse resistance to AVP, 10 IDDM subjects with poor glycemic control (Hb A(Ic) >9%) were studied before (B) and after (A) intensified glycemic control. Maximum urine osmolality in response to AVP increased with improved glycemic control (B, 443.8+/-49.0; A, 640.0+/-137.2 mosmol/kg, P<0.001), and urinary aquaporin-2 concentrations after AVP increased from 112.7 +/-69 to 375+/-280 fmol/mg creatinine (P = 0.006), with improved glycemic control. Poorly controlled IDDM is associated with reversible renal resistance to AVP.

Adolescent↗
PubMed2000

Non-ergot dopamine agonist-induced sleep attacks.

Two patients with Parkinson's disease received treatment with ropinirole and/or pramipexole, during which both experienced sleep attacks. These attacks may be a class effect of non-ergot dopamine agonists. Health care professionals should be aware of the potential of these agents to cause sleep attacks and caution patients about this potentially life-threatening adverse effect.

Aged↗
PubMed2000

Dietary unsaturated fatty acids in type 2 diabetes: higher levels of postprandial lipoprotein on a linoleic acid-rich sunflower oil diet compared with an oleic acid-rich olive oil diet.

OBJECTIVE: The present study was undertaken to examine the effect of a polyunsaturated fat diet compared with an isocaloric Mediterranean-style monounsaturated fat diet. RESEARCH DESIGN AND METHODS: This was a randomized 2-week crossover study on either a high-polyunsaturated or a high-monounsaturated fat diet in 11 well-controlled diabetic men. Blood was taken fasting and for up to 8 h after a high fat meal. Lipoproteins were isolated by sequential ultracentrifugation. Apolipoprotein (apo) B48 and apo B100 were separated by PAGE. Fatty acids were analyzed by gas-liquid chromatography RESULTS: Fasting blood glucose and insulin levels were significantly higher on the linoleic acid diet compared with the oleic acid diet (P < 0.01 and P < 0.002, respectively). Plasma cholesterol and LDL cholesterol levels were also significantly higher on the linoleic acid diet (P < 0.001). Likewise, fasting chylomicron apo B48 and apo B100 (P < 0.05) and postprandial chylomicron and VLDL apo B48 and B100 (P < 0.05) were also higher on the linoleic acid diet. CONCLUSIONS: This study suggests that, in type 2 diabetes, an oleic acid-rich Mediterranean-type diet versus a linoleic acid-enriched diet may reduce the risk of atherosclerosis by decreasing the number of chylomicron remnant particles.

Apolipoprotein B-48↗
PubMed2000

Learning to care for clients in their world, not mine.

Current literature and trends support the need to incorporate concepts for culturally focused nursing care and experiences with diverse cultures into nursing curricula. The purposes of this qualitative research were to describe the phenomena of being immersed in a different culture and to generate a conceptual map depicting process and outcomes of the immersion experience. From analysis of stories told by practicing nurses (n=9) who had an immersion experience during a baccalaureate program, a dimensional matrix emerged. The core dimension was learning to care. Situational predetermining factors included educational setting, personal characteristics, and demographic factors. Characteristics of the immersion context were site conditions. Transitional factors included strategies for "learning to care" such as social support, coping responses, and openness to adapt communication patterns. Outcomes included personal and professional growth in values, communication, and nursing practice. The matrix can guide nurse educators in incorporating immersion experiences into nursing curricula.

Acculturation↗
PubMed2000

Applications of computer-aided learning in biomedical sciences: considerations in design and evaluation.

Multimedia computer-aided learning (CAL) is an area that has become increasingly prevalent in biomedical science. Here we describe the advances that have taken place in the computing industry that have led to this trend. We also outline areas within the subject of biomedical science that can most benefit from using multimedia CAL as a teaching aid. Furthermore, issues concerning the design of CAL (i.e. iterative design, structure, development tools) are discussed. As the evaluation of CAL is an essential part of the iterative design process, we look at new approaches to evaluation that have emerged in response to the superficial focus on usability that many evaluations take.

Computer-Assisted Instruction↗
PubMed2000

The Naval Health Research Center Respiratory Disease Laboratory.

Concern about emerging and reemerging respiratory pathogens prompted the development of a respiratory disease reference laboratory at the Naval Health Research Center. Professionals working in this laboratory have instituted population-based surveillance for pathogens that affect military trainees and responded to threats of increased respiratory disease among high-risk military groups. Capabilities of this laboratory that are unique within the Department of Defense include adenovirus testing by viral shell culture and microneutralization serotyping, influenza culture and hemagglutination inhibition serotyping, and other special testing for Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumonia, and Chlamydia pneumoniae. Projected capabilities of this laboratory include more advanced testing for these pathogens and testing for other emerging pathogens, including Bordetella pertussis, Legionella pneumoniae, and Haemophilus influenzae type B. Such capabilities make the laboratory a valuable resource for military public health.

Clinical Laboratory Techniques↗
PubMed1999

Bacterial phosphatidylinositol-specific phospholipase C: structure, function, and interaction with lipids.

The bacterial phosphatidylinositol-specific phospholipase C (PI-PLC) is a small, water-soluble enzyme that cleaves the natural membrane lipids PI, lyso-PI, and glycosyl-PI. The crystal structure, NMR and enzymatic mechanism of bacterial PI-PLCs are reviewed. These enzymes consist of a single domain folded as a (betaalpha)(8)-barrel (TIM barrel), are calcium-independent, and interact weakly with membranes. Sequence similarity among PI-PLCs from different bacterial species is extensive, and includes the residues involved in catalysis. Bacterial PI-PLCs are structurally similar to the catalytic domain of mammalian PI-PLCs. Comparative studies of both prokaryotic and eukaryotic isozymes have proved useful for the identification of distinct regions of the proteins that are structurally and functionally important.

Bacteria↗
PubMed1999

Preventing stroke in patients with transient ischemic attacks.

Stroke is the third most common overall cause of death and the leading cause of adult disability in the United States. New therapeutic interventions instituted in the period immediately after a stroke have revolutionized the approach to ischemic cerebrovascular disease. Recognition of a transient ischemic attack provides an opportunity to prevent a subsequent stroke. Specific stroke prevention treatment depends on the cause of the transient ischemic attack, its cerebrovascular localization and the presence of associated coexisting medical problems. Modification of stroke risk factors is the principal therapeutic approach. Antiplatelet agents and anticoagulants have been shown to be effective in reducing the occurrence of stroke in certain populations. Several well-designed studies have recently demonstrated the effectiveness of carotid endarterectomy in preventing strokes related to extracranial carotid artery disease.

Adult↗
PubMed1999

Interaction of sildenafil and indinavir when co-administered to HIV-positive patients.

OBJECTIVES: The prevalence of erectile dysfunction in HIV-infected men is estimated to be 33%. Sildenafil citrate (Viagra; Pfizer Ltd, Sandwich, Kent, UK) is the first oral drug for this condition. Since sildenafil and the protease inhibitors are both metabolized by, and act as inhibitors of cytochrome P450 3A4, we evaluated the pharmacokinetics of the combination sildenafil plus indinavir in HIV-infected patients. DESIGN AND METHODS: Six patients at steady state in treatment with indinavir participated in the study. On the first day blood samples for indinavir assay were drawn at times 0, 1, 2, 3, 4, 6 and 8 h after dosing. On the second study day patients received a single dose of 25 mg of sildenafil in addition to their routine morning medication. Blood samples were taken as described. Separated plasma was stored at -80 degrees C until analysis by high performance liquid chromatography. In a parallel study, the effect of indinavir, ritonavir, saquinavir and nelfinavir on the in vitro hepatic metabolism of sildenafil was assessed. RESULTS: The geometric mean area under the concentration curve for 0-8 h (AUC0-8h) and maximum plasma concentration (Cmax) for indinavir were 19.69 microg/ml h (range, 9.19-31.99 microg/ml h) and 7.02 microg/ml (range, 2.33-16.17 microg/ml), respectively, on the first study day. In the presence of sildenafil, the mean AUC0-8h and Cmax of indinavir were 22.37 microg/ml h [range, 10.08-37.25 microg/ml h; 95% confidence interval (CI) for difference between means, -15 to 13.25) and 9.11 microg/ml (range, 3.41-22.78 microg/ml; 95% CI, -13 to 6.37), respectively. The geometric mean AUC0-8h and Cmax for sildenafil were 1631 ng/ml h (range, 643-2970 ng/ml h) and 384 ng/ml (range, 209-766 ng/ml) respectively. The AUC for sildenafil was 4.4 times higher than data from historical controls given either 50 mg or 100 mg of sildenafil and dose normalized to 25 mg. Indinavir was a potent inhibitor of sildenafil hepatic metabolism in vitro [concentration producing 50% inhibition of control enzyme activity (IC50) = 0.39 +/- 0.17 microM, mean +/- SD]. CONCLUSIONS: Co-administration of sildenafil 25 mg did not significantly alter the plasma indinavir levels. However, plasma sildenafil AUC was markedly increased in the presence of indinavir compared with historical controls. From the in vitro data, the mechanism of increase is indinavir inhibition of the hepatic metabolism of sildenafil. The magnitude of this interaction suggests a lower starting dose of sildenafil may be more appropriate in this clinical setting.

Adult↗