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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 721 records · Page 40Linked to original sources
PubMedDate not supplied

Doppler assessment of left ventricular diastolic function: a review.

Two-dimensional echocardiography provides valuable information for the assessment of left ventricular function. Traditionally, evaluation has focused on determination of systolic performance. However, recent investigations indicate diastolic dysfunction may also contribute to symptoms of congestive heart failure in many patients despite normal systolic function. Pulsed Doppler echocardiography complements two-dimensional imaging for assessment of left ventricular filling properties that are often altered in the setting of diastolic dysfunction. The concept of diastolic function and recognition of abnormal filling patterns detected by pulsed Doppler echocardiography are reviewed.

Blood Flow Velocity↗
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Intensive plasma exchange therapy in ten patients with idiopathic thrombocytopenic purpura.

Intensive plasma exchange therapy with fresh-frozen plasma as the replacement fluid was used to manage ten patients, five with acute and five with chronic immune thrombocytopenic purpura (ITP). Therapy was started because of severe hemorrhage (1 case), failure to respond to steroid therapy (6 cases), or steroid dependence (3 cases). After a median of four exchanges over 6 days (median total volume removed, 11.7 liters), initial responses, defined as a platelet count greater than 100,000 per microliter at the end of the exchange series, were observed in 80 percent of the patients treated. Two adolescents, ages 16 and 17 years, with chronic ITP failed to respond to plasma exchange therapy and subsequently responded to splenectomy. Prolonged remissions of 9 months and greater than 2 years were observed in two patients with acute ITP; in patients with chronic ITP, no prolonged remissions occurred. Neither pre-exchange levels of platelet-associated immunoglobulin G (PAIgG) nor circulating immune complexes predicted the response to plasma exchange, although serially determined PAIgG levels correlated with the severity of ITP and response, or lack of response, to plasma exchange. We conclude that intensive plasma exchange merits further study in patients with acute ITP unresponsive to steroid therapy to determine if the need for splenectomy is reduced. In selected patients with chronic ITP, exchange therapy may provide short-term adjunctive benefit.

Adolescent↗
PubMedDate not supplied

HLA antigens in four Pacific populations with non-insulin-dependent diabetes mellitus.

HLA antigen distributions in persons with normal and abnormal glucose tolerance were compared in four Pacific populations. The populations included Melanesians from the Fijian Islands, Loyalty Islands and mainland New Caledonia and Polynesians from the Wallis Islands. HLA-DR results are provided for the first time for Pacific groups. In Polynesians, HLA-B22 was increased in frequency in patients with non-insulin-dependent diabetes mellitus and also in persons with impaired glucose tolerance. However, the association was not statistically significant when corrected for the number of antigens tested. A similar increase in HLA-B22, although not significant, was seen in each of the three Melanesian populations with abnormal glucose tolerance. No other consistent increase in any HLA antigen occurred in persons with abnormal plasma glucose concentrations.

Diabetes Mellitus↗
PubMedDate not supplied

A randomized, controlled trial of two-thumb vs two-finger chest compression in a swine infant model of cardiac arrest [see comment].

BACKGROUND: The American Heart Association (AHA) currently recommends two-finger (TF) chest compression for infants. A previous study demonstrated that two-thumb (TT) with lateral chest wall compression provided significantly higher arterial pressures than did the TF method. Limitations of that study included the lack of an asphyxial model and non-standardized compression forces. OBJECTIVE: To test the hypothesis that TT chest compression generates higher arterial pressures than does the TF method, using an asphyxial model. Also, by standardizing sternal compression force (SCF), the authors sought to show that the increased pressures are the result of thoracic compression. METHOD: The study was a randomized, crossover trial in immature swine weighing 10 kg. Each swine was sedated, anesthetized, paralyzed, intubated, and mechanically ventilated on room air. A femoral arterial catheter was placed. Cardiac arrest was induced by asphyxiation and verified by ECG and pressure tracings. Eleven AHA-certified basic rescuers each randomly performed four 1-minute trials of external chest compressions. Each of the two CPR techniques was performed, with and without feedback of SCF. Compression forces were measured using the Uniforce Sensor System (Force Imaging Technology, Inc., Chicago, IL). During the feedback mode, the rescuers were instructed to maintain sternal pressures at 20-25 psi. During the nonfeedback mode, the rescuers were blinded to the force transducer. All compressions were analyzed for systolic blood pressure (SBP), diastolic blood pressure (DBP), and SCF. Data were analyzed using repeated-measures analysis of variance (RMANOVA) and Tukey multiple comparisons (alpha = 0.05). RESULTS: A total of 2,297 compressions were analyzed. The TT method produced significantly higher SBPs both with (25% increase) and without (57% increase) feedback when compared with the TF. The DBPs were not significantly different. The SCFs were also significantly higher in the two groups with feedback. The SCFs in the TF groups did not reach the standardized value of 20 psi, whereas in the TT groups, both were in the range of 20-25 psi. CONCLUSION: The TT method produced significantly higher SBPs. The authors were unable to demonstrate that the increased SBPs were secondary to the thoracic compression component because the rescuers did not reach the predetermined SCF in the TF groups. In this swine model of infant CPR, TT chest compression is an easier and more effective method.

Animals↗
PubMedDate not supplied

The assessment of recovery in patients after myocardial infarction using three generic quality-of-life measures.

BACKGROUND: To evaluate the sensitivity to change of three generic quality-of-life measures in patients after myocardial infarction (MI). METHODS: Patients admitted to the Coronary Care Unit of Royal Devon and Exeter Healthcare Trust over a 9-month period were selected on the basis of a first MI and under 80 years of age. Quality of life was assessed 6 weeks and 6 months after MI using the Sickness Impact Profile (SIP), Nottingham Health Profile (NHP), and McMaster Health Inventory Questionnaire (MHIQ). An index of whether these measures are sensitive to change over time was determined by dividing the mean change from 6 weeks to 6 months of each instrument subscale by the baseline standard deviation of that subscale. Values of 0.2, 0.5, and 0.8 and above represent modest, moderate, and good sensitivity, respectively. RESULTS: Eighty-eight patients completed and returned the quality-of-life measures at both 6 weeks and 6 months. Four SIP subscales achieved a sensitivity to change index of 0.20 to 0.50: body care and movement, emotional behavior, work, and eating. Other SIP, NHP, and MHIQ subscales showed sensitivity index values of less than 0.20. No sensitivity index values of 0.50 or more were observed. CONCLUSIONS: During the period of this study, all three generic quality-of-life measures displayed only modest levels of sensitivity to change. Other quality-of-life measures need to be developed for the assessment of cardiac patients. This is particularly important when choosing suitable quality-of-life measures to assess cardiac rehabilitation.

Aged↗
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Behaviour therapy for phobia of venepuncture.

A 28-year-old female insulin-dependent diabetic patient developed a severe phobia to venepuncture which seriously interfered with her medical treatment. A two-month course of behaviour therapy successfully alleviated the phobia.

Adult↗
PubMedDate not supplied

The prognostic value of stress hyperglycaemia and previously unrecognized diabetes in acute stroke.

In a prospective study of 86 patients with acute stroke, blood glucose and HbA1 were estimated within 72 h of onset. The prevalence of previously diagnosed diabetes mellitus was 8% whereas 28% could be assumed to have had unrecognized hyperglycaemia preceeding the acute event as identified by a stable HbA1 raised more than two SD above the mean reference value. Complete functional recovery of the limbs within 4 weeks of the stroke was confined to those patients with a normal admission blood glucose. None of the patients with a raised admission blood glucose regained full functional recovery within 4 weeks. Cumulative mortality at 4 weeks was significantly raised in patients with an elevated blood glucose value irrespective of their HbA1 values (p less than 0.05). The prevalence of unrecognized hyperglycaemia as a risk factor for acute stroke is greater than previously reported in the UK and admission blood glucose concentration is of greatest importance in predicting early mortality and morbidity.

Adult↗
PubMedDate not supplied

Continuous subcutaneous insulin infusion versus injection therapy: a randomized cross-over trial under usual diabetic clinic conditions.

Twelve C-peptide negative insulin-dependent diabetic patients participated in a randomized cross-over study of 6 months treatment with twice or thrice daily insulin injection therapy and continuous subcutaneous insulin infusion (CSII). Standard, non-intensified management conditions were maintained throughout. Glycosylated haemoglobin levels were similar on both regimens (9.2 +/- 0.5% versus 9.0 +/- 0.4%; CSII vs injection therapy; (mean +/- SEM). Capillary blood glucose concentrations before breakfast (5.2 +/- 0.4 mmol/l vs 9.1 +/- 0.8 mmol/l), after lunch (6.5 mmol/l +/- 0.8 vs 7.9 +/- 1.0 mmol/l) and before the evening meal (5.0 +/- 0.7 mmol/l vs 7.7 +/- 0.7 mmol/l) were lower on CSII, as were 24-hour urine glucose excretion and total insulin dose (39.3 +/- 2.2 vs 49.8 +/- 4.0 U/day). There was a significant positive correlation between fasting blood glucose values and glycosylated haemoglobin on injection but not pump treatment. Thus although blood glucose control at some individual daytime points appeared lower on CSII, overall diabetic control was similar on the two regimens.

Adolescent↗
PubMedDate not supplied

Increased proximal tubular sodium reabsorption in hypertensive patients with type 2 diabetes.

Hyperinsulinaemia and sodium retention have been studied in 22 Type 2 diabetic patients (10 normotensive, 12 hypertensive) and 10 normal control subjects matched for age, sex, and body mass index. Exchangeable sodium was similar in the three groups. Plasma renin activity and plasma angiotensin II were lower in both groups of diabetic patients than in the normal control subjects (p less than 0.01). Plasma atrial natriuretic peptide was increased in the hypertensive patients (7.3 +/- 1.1 vs normotensive 4.7 +/- 1.1 pmol l-1 and control 4.0 +/- 0.2 pmol l-1, p less than 0.01). Fractional lithium clearance, a measure of sodium clearance from the proximal tubule, was decreased (18.5 +/- 1.4, p less than 0.01) and fractional excretion of sodium in the distal tubule was increased (6.66 +/- 0.66, p less than 0.01) in untreated hypertensive diabetic patients compared with both normotensive diabetic patients (25.3 +/- 1.6 and 3.96 +/- 0.52 respectively) and normal control subjects (25.2 +/- 2.9 and 3.31 +/- 0.38, respectively). Fasting serum insulin was higher in hypertensive than in normotensive diabetic patients (18.5 +/- 3.0 vs 10.7 +/- 1.1 mU l-1, p less than 0.01) and higher in both groups than in normal control subjects (5.6 +/- 0.1 mU l-1, both p less than 0.01). Creatinine clearance was higher in both groups of diabetic patients than in normal control subjects (p less than 0.05). Thus there appears to be increased proximal renal tubular sodium reabsorption in these hypertensive Type 2 diabetic patients, matched by a reduction in distal sodium reabsorption so that net sodium excretion was maintained. This was associated with fasting hyperinsulinaemia.

Aldosterone↗
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The effect of intravenous metformin on glucose metabolism during hyperglycaemia in type 2 diabetes.

A stepped intravenous metformin infusion was used in conjunction with the hyperglycaemic clamp technique to study the dose-response relationship of plasma metformin concentration with hepatic glucose production and peripheral glucose disposal in nine patients with Type 2 diabetes. The study was of double-blind crossover design, using NaCl infusion as control. Plasma metformin concentrations spanning the therapeutic range (1.64 +/- 0.13 mg l-1 and 6.57 +/- 0.61 mg l-1) were achieved. No differences in peripheral glucose disposal were demonstrated when compared with NaCl infusion (3.4 +/- 0.1 vs 3.6 +/- 0.2 (+/- SE) mg kg-1 min-1 and 3.4 +/- 0.2 vs 3.3 +/- 0.2 mg kg-1 min-1, respectively). There was also no difference in basal hepatic glucose production during metformin and NaCl infusion (2.7 +/- 0.3 vs 2.8 +/- 0.2 mg kg-1 min-1). No acute effect of metformin on hepatic glucose production or peripheral glucose disposal was observed, implying that a chronic persistent effect is more important in these respects than immediate effects consequent upon changes in plasma drug level.

Blood Glucose↗
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A collaborative approach to nursing research: Part I, The process.

Although many nurse practitioners may be interested in documenting aspects of their practice through research, resource and time constraints can limit the opportunity. Collaboration can be a practical and rewarding approach to making research feasible for clinicians. Under the auspices of a professional nursing organization, a group of San Francisco Bay area nurse practitioners conducted a survey designed primarily to increase membership in their organization. This article details the process by which the research was conducted and serves as a guide for clinicians about to undertake a similar project.

Humans↗
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A collaborative approach to nursing research: Part II, The findings. A profile of San Francisco Bay area nurse practitioners and their needs.

A collaborative research project conducted by nurse practitioners (NPs) was undertaken to establish a profile of NPs practicing in the San Francisco Bay area. The profile consisted of information regarding educational preparation, certification, employment status, salary, and practice characteristics. A mail survey of all Bay area NPs was implemented to obtain the information used in program planning and membership recruitment for the Primary Care Nurse Practitioner Interest Group of Region 12 of the California Nurses' Association. The results revealed the types of programs desired and common barriers to participation. Based on these findings, changes were made in the program format and offerings to make the organization more responsive to the needs of NPs.

Adult↗
PubMedDate not supplied

A slice geometry phantom for cross sectional tomographic imagers.

This investigation presents the design and fabrication of a magnetic resonance imaging (MRI) test phantom for determining slice thickness, slice adjacency, slice offset, and slice angulation. This test phantom is a three-dimensional conic section of MRI image producing material; proper orientation allows analysis in each of the major imaging planes. The phantom design (geometrical configuration) incorporates both theoretical and quantitative methodologies. The necessary mathematical analyses are both simple and rapid. In addition, this phantom has been successfully used to assess the image slice parameters for computed tomography (CT) scanners and single photon emission computed tomography (SPECT) imaging systems. Slice profile parameter results, full width at half maximum (FWHM), from this phantom design are compared with conventional methods.

Humans↗
PubMedDate not supplied

Guar crispbread in the diabetic diet.

Nine diabetic patients who were receiving various treatments supplemented their normal home diets (two patients) or metabolic ward diets (seven patients) with guar crispbread for five days. Their mean urinary glucose excretion fell significantly by 38% during the last two days. A significant fall in fasting blood glucose concentration of 1.1 +/- 0.4 mmol/1 (19.8 +/- 7.2 mg/100 ml) was seen only in those who took guar after the control period. Over eight weeks' treatment insulin dosage was reduced by 21% in five patients, and home testing showed that glycosuria was reduced by 68% in six patients. Guar crispbread is likely to be a useful adjunct to diabetic treatment irrespective of the type of treatment or insulin dosage used.

Adult↗
PubMedDate not supplied

High density lipoprotein apoprotein variability in a biracial population.

High density lipoprotein (HDL) cholesterol is a sensitive index for coronary disease in affluent societies. We have measured plasma apoprotein A-I levels (the major HDL protein) in randomly selected groups of urban and rural Fijian Melanesians and Indians. Despite higher prevalence rates of coronary disease and diabetes mellitus in Indians, Indian men and women had significantly higher A-I levels than Melanesian men and women. Multivariate analysis was carried out separately in all men and women of both races and also in younger men and women (less than 45 years old) to determine the predictive values of seven variables that might influence A-I levels. These variables accounted for about 16% of the A-I variation and of this more than one-half was due to ethnic origin. The remainder was largely due to three environmental factors: urbanization, alcohol consumption, and physical activity. Men and women aged 20 to 44 years had significantly higher A-I levels in the town than in villages; alcohol drinkers had significantly higher A-I levels than nondrinkers, and in women physical inactivity resulted in significantly lower A-I levels. Age, smoking cigarettes, and body mass index did not contribute to the differences in A-I levels between the two races, despite less smoking and overweight among Indians. This study of a biracial population, that shares a similar environment but differs in cultural habits, has demonstrated the operation of genetic and environmental factors that explain a minor proportion of apoprotein A-I variability.

Adult↗