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Biomedical subjects

B Burns

Publications and source records attributed to B Burns.

At least 37 records · Page 2Linked to original sources
PubMed1990

A prospective randomised controlled trial of antimicrobial prophylaxis in hydrocephalus shunt surgery.

Despite attempts to reduce their incidence, shunt infections remain a major complication of the treatment of hydrocephalus. Various forms of antimicrobial prophylaxis are in use, but no controlled, statistically valid trial has been conducted to assess their efficacy. Such a trial was therefore carried out and its design is described here. After a 1-year retrospective and prospective study by members of the United Kingdom Hydrocephalus Group to establish feasibility and infection rates, a statistical study showed that at least 712 patients would be required. Six centres were enrolled to fulfil these requirements, and ethical committee approval was obtained at each. The chosen prophylactic regimen was 10 mg vancomycin administered into the ventricular system during surgery. Adults and children undergoing insertion or revision of ventriculoperitoneal shunts were included unless they were receiving therapeutic antimicrobials. Randomisation was by computer-generated numbers. Controls received the antimicrobial regimen, if any, currently used in that centre, the only difference between the two groups being intraventricular vancomycin in the test group. Diagnosis of shunt infection included accepted clinical and microbiological criteria reinforced by measurement of serum C-reactive protein levels. Follow-up was for at least six months. After 2.5 years only 158 patients had been enrolled in the trial, 80 controls and 78 tests. There were 5 preventable infections in the control group and 2 in the test group. In view of the small total the planned statistical analysis was not possible. Therefore, while no problems were encountered with toxicity, the trial failed to enroll enough patients to answer the question of efficacy of antimicrobial prophylaxis in shunt surgery and the reasons for this are discussed.

Cerebrospinal Fluid Shunts↗
PubMed1988

Nalbuphine analgesia in the prehospital setting.

Forty-six patients with moderate to severe pain caused by orthopedic injuries, burns, multiple trauma, or intraabdominal conditions were treated with intravenous (IV) nalbuphine hydrochloride (Nubain; DuPont Pharmaceuticals, Wilmington, DE) by paramedics before arrival at the hospital. Patients who weighed less than 60 kg received 15 mg nalbuphine, and patients weighing greater than 60 kg received 20 mg nalbuphine. Forty-one of 46 patients (89%) experienced pain relief from nalbuphine, with maximum relief occurring within 15 minutes after the administration of the drug. Two addicted patients received no pain relief. There were no untoward side effects following nalbuphine administration, and the patients' heart rates, mean arterial pressures, and respiratory rates remained constant and stable throughout the study period. Repeated assessment of the patient by paramedics in the field was not impaired by nalbuphine treatment. In summary, nalbuphine hydrochloride is a useful and safe analgesic drug for IV use by paramedics in the prehospital setting.

Adolescent↗
PubMed1988

Comparison of active and combined passive/active immunization of Navajo children against Haemophilus influenzae type b.

In a high risk Navajo population we compared the immunogenicity of a new Haemophilus influenzae type b mutant-diphtheria toxic conjugate vaccine (HbOC) with simultaneous active (HbOC) and passive immunization with bacterial polysaccharide immunoglobulin prepared from adults immunized with H. influenzae b, pneumococcal and meningococcal vaccines. Only 7 of 26 (27%) 2-month-olds had an increase in H. influenzae b capsular polysaccharide antibody after a single dose of HbOC, a proportion similar to that of saline controls (9 of 25, 36%). After a second HbOC dose at 4 months 88% had antibody concentrations of 0.15 microgram or more, and after a third dose at 6 months all had antibody levels greater than or equal to 0.15 microgram/ml. The group receiving both HbOC and bacterial polysaccharide immunoglobulin at 2 months uniformly had H. influenzae b CP antibody concentrations of greater than or equal to 0.15 microgram/ml at 4 months (P less than 0.001 relative to "HbOC alone" group) and subsequently responded similarly to second and third doses of HbOC vaccine as did also the "HbOC alone" group. We conclude that combined passive/active immunization with bacterial polysaccharide immunoglobulin and HbOC at 2 months maintains antibody at concentrations thought to be protective (greater than or equal to 0.15 microgram/ml) without interfering with the active antibody response to second and third doses of HbOC at 4 and 6 months of age.

Bacterial Capsules↗
PubMed1987

Anxiety and depression in a primary care clinic. Comparison of Diagnostic Interview Schedule, General Health Questionnaire, and practitioner assessments.

Over one half of all persons seen in a primary care clinic were identified as having anxiety or depressive disorder by the primary care provider, the General Health Questionnaire (GHQ), or the Diagnostic Interview Schedule (DIS). In only about 5% of all patients were findings positive on all three assessments concurrently. Both the GHQ and the practitioners identified over 30% of all patients as having a disorder, while about 8% had one or more of five DIS anxiety or depressive disorders (major depression, dysthymia, panic disorder, generalized anxiety disorder, or obsessive-compulsive disorder). Of the patients with DIS disorders 83% had positive GHQ scores, and 73% were identified by the practitioner as having a mental disorder.

Adolescent↗
PubMed1986

Perceptual development and categorization: I. An investigation of task demands, stimulus set similarity, and age.

This research addressed the apparent inconsistency in the literature between perceptual development as a progression of increasing separability (Shepp, 1978; Smith & Kemler, 1977, 1978) and categorization as a process based on overall similarity relations across development (Mervis, 1980; Mervis & Rosch, 1981). The influence of task demands, stimulus set similarity, and age on organizing principles of perceptual similarity were examined. Findings suggest that stimulus set similarity is an important factor in determining organizing principles of similarity for both nursery school children and adults.

Attention↗
PubMed1986

Relationship of perceived stimulus structure and intelligence: further tests of a separability hypothesis.

The representation of objects by moderately and mildly mentally retarded subjects was determined using a classification task in which triads of objects were presented that placed classification by overall similarity relations and classification by shared dimensional relations in conflict. Results indicate that a separability hypothesis of normal perceptual development (Kemler, 1982; Shepp, Burns, & McDonough, 1980; Smith, 1979; Smith & Kemler, 1977) can be extended to retarded populations. Representation as unitary wholistic objects dominated among moderately retarded subjects, and with increasing intelligence, the representation of objects as component separable dimensions began to emerge.

Adolescent↗
PubMed1985

Oral rehydration therapy for acute diarrhea in ambulatory children in the United States: a double-blind comparison of four different solutions.

Oral rehydration solutions containing 50 to 90 mmol/L of sodium have recently been recommended for the treatment of diarrhea in both hospitalized and ambulatory children in the United States. Few data are available, however, from ambulatory US children. Therefore, we conducted a randomized double-blind study comparing the use of four different oral rehydration solutions with differing concentrations of sodium, glucose, and base. Ambulatory children less than 2 years of age with acute diarrhea (N = 140) were randomly chosen to receive solutions containing sodium at 90 (solution A), 50 (solution B), and 30 mmol/L (solutions C and D). All oral rehydration solutions contained 20 g/L of glucose except solution D which contained 50 g/L of glucose. Solution A contained bicarbonate as its base source whereas the other three contained citrate. All but three (98%) children were treated uneventfully according to the study protocol, and there were no differences among groups in measurements of clinical outcome. It was concluded that in ambulatory US children, oral rehydration solutions containing 90, 50, or 30 mmol/L of sodium can be used safely for the treatment of mild acute diarrhea and that citrate is as efficacious as bicarbonate in the correction of acidosis.

Ambulatory Care↗
PubMed1985

Role of soy-based, lactose-free formula during treatment of acute diarrhea.

A controlled study was conducted comparing the standard method of treating hospitalized infants with acute diarrhea (limited starvation) with the initiation of "early feeding" using a soy-based, lactose-free formula in infants of an American Indian tribe 12 months of age or younger. Forty-three patients, randomly assigned to group A, were given a soy-based, lactose-free formula four hours after hospitalization, and 44 patients, randomly assigned to group B, received standard therapy (food was withheld for the first 48 hours of hospitalization). After the first 48 hours, the same soy-based, lactose-free formula was given to the group B patients. Fluid intake and output of stool, urine, and vomitus were measured until the diarrhea resolved. Overall, group A patients showed less mean stool output (121 +/- 129 (SD) mL/kg) than group B patients (299 +/- 319 mL/kg) (P less than .001). Furthermore, the duration of illness was significantly shorter in group A patients (54 +/- 28 hours v 93 +/- 56 hours) (P less than .001). It was concluded that soy-based, lactose-free formulas can be safely used during the acute phase of diarrheal illness in infants and that their use shortens the duration of illness and decreases stool output in comparison with standard therapy.

Combined Modality Therapy↗
PubMed1984

Stimulus structure in visual persistence: an examination of selective adaptation effects on phenomenal continuity.

The effects of adaptation by stimuli composed of the dimensions of color, orientation and size were measured on the visual persistence of a red vertical 3.5 c/d grating. Adaptation by the stimulus that shared an identical level on each of the three-component dimensions of the test stimulus decreased the visual persistence of the test stimulus. There was no effect of adaptation on visual persistence when the adapting stimulus and test stimulus shared an identical level on zero-, one-, or two-dimensional components. The present results extend the investigation of selective adaptation effects on visual persistence by Meyer, Lawson , Cohen, and Maquire to color, size and orientation. In addition, these results are in excellent agreement with Burns' finding that physically integral stimuli are represented in iconic memory as integral unitary wholes and not as dimensional components.

Adaptation, Ocular↗
PubMed1982

Changes in lung membrane diffusing capacity for oxygen produced by halothane.

The effect of halothane on membrane diffusing capacity for O2 (DMO2) was measured in isolated left lower lobes of dog lungs using the sodium dithionite method. At 25 degrees C, halothane reduced DMO2 according to the regression equation: per cent control DMO2 = -4.85(per cent halothane) + 97.5 (r = -0.55, P = 0.0007). Although DMO2 was reduced from control by halothane administration, lung volume (VL) increased at higher halothane concentrations and tended to restore DMO2 by increasing surface area. There was a better correlation between the DMO2/VL ratios and per cent halothane: per cent (DMO2/VL) = -5.76 (per cent halothane) + 95.6 (r = -0.65, P = 0.00003). Effects of halothane on DMO2 and VL were reversible and were not influenced by gas mixing efficiency since argon dilution half-times over two decades were unchanged by halothane. It is unlikely that altered vascular recruitment affected the measured DMO2 since resistance to blood flow was unchanged. We conclude that halothane decreases DMO2 by either decreasing the physical diffusion coefficient (D') for O2 or decreasing the effective O2 solubility (alpha), or both, in the alveolar-capillary membrane.

Animals↗
PubMed1982

Increased cardiac output following occlusion of the descending thoracic aorta in dogs.

Occlusion of the thoracic aorta (AO) in dogs with a constant volume right ventricular extracorporeal bypass increased cardiac output (Q) by 43% and mean arterial pressure by 46%, while mean systemic pressure (MSP) was unchanged. We compared AO with occlusion of the brachiocephalic and left subclavian arteries (BSO) which decreased cardiac output by 5%, increased mean arterial pressure by 32%, and increased MSP by 11%. We feel these results confirm that AO elevates preload by transferring blood volume from the splanchnic veins to the vascular system drained by the superior vena cava. If the heart is competent to keep right arterial pressure at or near zero, this increase in preload will elevate Q above control levels. Comparing our data with results of other authors who have not controlled right atrial pressure, emphasizes the importance of a competent right ventricle in allowing venous return to determine Q.

Animals↗
PubMed1982

Interactions between placental O2 and CO transfer.

In 14 pregnant ewes the fetal side of the placenta was artificially perfused with adult sheep blood or with an emulsion of the fluorocarbon FC-47 containing varying amounts of CO. We measured diffusing capacities for O2 and Ar and permeability for urea and tritiated water (3H2O). We found that O2 diffusing capacity fell markedly in the presence of low levels of CO but that AR diffusing capacity and the permeability of urea and 3H2O remained constant at different levels of exposure to CO. We interpret the results as being consistent with the hypothesis that placental O2 transport is partially carrier mediated and that O2 and CO compete for the same carrier.

Animals↗