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Biomedical subjects

J Barr

Publications and source records attributed to J Barr.

At least 55 records · Page 3Linked to original sources
PubMed1999

Abnormal visual evoked potentials in children with "Alice in Wonderland" syndrome due to infectious mononucleosis.

Visual illusions characterized by distortion of form, size, reciprocal position of objects, movement, or color, labeled as "Alice in Wonderland" syndrome, were discussed in children with infectious mononucleosis, as well as in other clinical conditions, such as migraine, epilepsy, use of certain hallucinogenic drugs, etc. The purpose of our study was to investigate for the first time visual evoked potential results in children with "Alice in Wonderland" syndrome associated with infectious mononucleosis. Five children with "Alice in Wonderland" syndrome associated with infectious mononucleosis underwent visual evoked potential studies during and after their clinical symptoms. Visual evoked potential results during the disease demonstrated statistically significant high amplitudes of P100-N145 in all children compared to the control group. A few weeks later, repeated studies after the resolution of the complaints were normal. Since the same findings can be observed in patients with migraine, we postulate that a common pathophysiologic underlying abnormality, which can cause transient focal decreased cerebral perfusion, could be involved in the disease process of these two conditions.

Adolescent↗
PubMed1999

Immunisation coverage at a well-baby clinic in the United Arab Emirates.

The United Arab Emirates Survey of Immunisation Coverage by UNICEF in 1990 showed that the coverage for UAE infants up to one year of age was 60%. The objective of this study was to determine factors associated with attendance and immunisation uptake at a well-baby clinic. A birth cohort of 665 infants were selected and their records examined to determine the factors such as gender, distance of housing area from clinic and access to other primary health care facilities. Only 22% attended all the scheduled visits and 54.3% of the sample completed the immunisation program within the correct time. The distance the infant lived from the clinic was the only factor significantly affecting immunisation uptake. The identification and targeting of groups at high risk of delayed completion of the immunisation program is a necessary risk factor in improving future surveillance.

Chi-Square Distribution↗
PubMed1999

Acute iron intoxication: the efficacy of deferiprone and sodium biocarbonate in the prevention of iron absorption from the digestive tract.

To determine whether enteral deferiprone given after a loading dose of liquid iron interferes with iron absorption from the digestive tract, prospective randomized animal study was initiated using Sprague-Dawley rats. The rats were given 20 mg elemental iron/kg as a ferrous sulfate solution + 1 mEq sodium bicarbonate/kg, and then dosed orally with 150 mg deferiprone/kg immediately or after 15 min. Serum iron levels were measured at 1, 3, 5 and 24 h; feces were collected for 24 h. The 20 mg elemental iron/kg caused a significant and rapid increase in serum iron levels to > 350 micrograms/dL within 20 min of oral dosing. Deferiprone, if given immediately after the iron, produced a significant decrease in serum iron levels and a 2-fold increase in iron excretion in feces. Effectiveness was delayed when the deferiprone was given 15 min after the iron dosing. Enteral deferiprone might be useful in preventing cases of acute iron intoxication.

Animals↗
PubMed1998

'Respiratory epilepsy'--does it exist?

Past literature suggests a possible relationship between two recurrent illnesses: bronchial asthma and epilepsy. Only one preliminary study, performed 30 years ago, demonstrated epileptiform EEG activity in patients with bronchial asthma who were treated successfully for their asthma with antiepileptic drugs. We demonstrated epileptiform activity in six out of 24 (25%) children with bronchial asthma who had no history of neurological illnesses or epilepsy, compared to one out of 24 (4.2%) children in the control group. This relatively high percentage of EEG abnormalities raises the possibility that there is a subgroup of patients with bronchial asthma, in whom the asthma might be considered as an 'epileptic equivalent'. These patients possibly deserve a different, unique therapeutic approach.

Adolescent↗
PubMed1998

Perceived social support and community adaptation in schizophrenia.

Prompted by the continuing transition to community care, mental health nurses are considering the role of social support in community adaptation. This article demonstrates the importance of distinguishing between kinds of social support and presents findings from the first round data of a longitudinal study of community adaptation in 156 people with schizophrenia conducted in Brisbane, Australia. All clients were interviewed using the relevant subscales of the Diagnostic Interview Schedule to confirm a primary diagnosis of schizophrenia. The study set out to investigate the relationship between community adaptation and social support. Community adaptation was measured with the Brief Psychiatric Rating Scale (BPRS), the Life Skills Profile (LSP) and measures of dissatisfaction with life and problems in daily living developed by the authors. Social support was measured with the Arizona Social Support Interview Schedule (ASSIS). The BPRS and ASSIS were incorporated into a client interview conducted by trained interviewers. The LSP was completed on each client by an informal carer (parent, relative or friend) or a professional carer (case manager or other health professional) nominated by the client. Hierarchical regression analysis was used to examine the relationship between community adaptation and four sets of social support variables. Given the order in which variables were entered in regression equations, a set of perceived social support variables was found to account for the largest unique variance of four measures of community adaptation in 96 people with schizophrenia for whom complete data are available from the first round of the three-wave longitudinal study. A set of the subjective experiences of the clients accounted for the largest unique variance in measures of symptomatology, life skills, dissatisfaction with life, and problems in daily living. Sets of community support, household support and functional variables accounted for less variance. Implications for mental health nursing practice are considered.

Adaptation, Psychological↗
PubMed1998

Population pharmacokinetics of midazolam administered by target controlled infusion for sedation following coronary artery bypass grafting.

BACKGROUND: Midazolam is commonly used for short-term postoperative sedation of patients undergoing cardiac surgery. The purpose of this multicenter study was to characterize the pharmacokinetics and intersubject variability of midazolam in patients undergoing coronary artery bypass grafting. METHODS: With institutional review board approval, 90 consenting patients undergoing coronary artery bypass grafting were enrolled at three study centers. All subjects received sufentanil and midazolam via target-controlled infusions. After operation, midazolam was titrated to maintain deep sedation for at least 2 h. It was then titrated downward to decrease sedation for a minimum of 4 h more and was discontinued before tracheal extubation. Arterial blood samples were taken throughout the study and were assayed for midazolam and 1-hydroxymidazolam. Midazolam population pharmacokinetic parameters were estimated using NONMEM. Cross-validation was used to estimate the performance of the model. RESULTS: The pharmacokinetics of midazolam were best described by a simple three-compartment mammillary model. Typical pharmacokinetic parameters were V1 = 32.2 l, V2 = 53 l, V3 = 245 l, Cl1 = 0.43 l/min, Cl2 = 0.56 l/min, and Cl3 = 0.39 l/min. The calculated elimination half-life was 15 h. The median absolute prediction error was 25%, with a bias of 1.4%. The performance in the cross-validation was similar. Midazolam metabolites were clinically insignificant in all patients. CONCLUSIONS: The intersubject variability and predictability of the three-compartment pharmacokinetic model are similar to those of other intravenous anesthetic drugs. This multicenter study did not confirm previous studies of exceptionally large variability of midazolam pharmacokinetics when used for sedation in intensive care settings.

Adult↗
PubMed1998

Comparison of repeat videokeratography: repeatability and accuracy.

PURPOSE: We compared the repeatability and accuracy of four commercially available videokeratography instruments and a manual keratometer. METHODS: Ten optometry students and two university employees who had no history of rigid contact lens wear and no soft contact lens wear within 6 months of the study were measured. Two independent measurements were taken on the right eyes only using the Alcon EyeMap EH-290 topography system (both manual and automatic focus), the EyeSys System 2000 corneal topography system, the Humphrey Mastervue topography system, the Humphrey Atlas topography system, and a Marco manual keratometer. A three-factor repeated measures analysis of variance with all factors repeated was performed using SAS and BMDP statistical software. Separate analyses were conducted for paracentral and peripheral data. To test accuracy, measurements were taken with the Alcon EyeMap automatic focus system, the EyeSys System 2000, the Humphrey Atlas system, and the Humphrey Mastervue system using four calibration spheres. RESULTS: There were no statistically significant differences in the repeatability of the instruments. The EyeSys corneal topography system had the most narrow 95% limits of agreement around the mean difference. The two Humphrey instruments performed similarly to the EyeSys. Although the Alcon EyeMap EH-290 had the widest 95% limits of agreement around the mean difference, it showed better repeatability when the manual focus was used compared with the automatic focus. The instruments varied in their level of accuracy, but the highest percentage of data points within +/- 0.37 D of the known values of the calibration spheres was found with the Humphrey Atlas. CONCLUSIONS: Although there were no statistically significant differences in repeatability, the EyeSys System 2000 had the highest repeatability, which may have clinical relevance. The accuracy measured in this study varied tremendously; however, the Humphrey Atlas was found to be the most accurate of the instruments tested.

Cornea↗
PubMed1998

Case study: nursing care of the patient with vertebral artery aneurysm treated by endovascular stenting and coil implantation.

As we move towards the 21st Century, it is evident that healthcare is significantly altered by advancements in technology. The following case study describes the first reported procedure in a human, in which a vertebral artery stent was inserted to act as a "bridge" for coil placement in the treatment of a wide-necked vertebral artery aneurysm. Due to the size, shape and calcification of the aneurysm, conventional neurosurgery and/or endovascular coiling were considered inappropriate obliterative mechanisms. Instead, a new therapy that combined surgical and endovascular techniques was successfully initiated. Therapies such as the stent procedure have only been successful in canine studies. Aneurysms unsuitable for conventional therapy, including clipping or endovascular techniques, were once thought untreatable. Stenting now provides the surgeon and patient with another therapeutic modality to better manage difficult wide-necked aneurysms.

Aneurysm↗
PubMed1998

The effect of grain storage conditions on the viability of Fusarium and deoxynivalenol production in infested malting barley.

A continuing outbreak of Fusarium head blight occurred on barley in the upper Midwest from 1993 to 1995. This resulted in barley with levels of the mycotoxin deoxynivalenol (DON) reaching levels of concern for maltsters and brewers. This study evaluated the effect of 7 months of storage under different conditions (ambient outdoor temperature from October to April), -20 degrees C, 4 degrees C, 24 degrees C with quiescent air, and 24 degrees C with forced air) on the viability of Fusarium and Alternaria infesting stored grain. Additionally, the ability of Fusarium to produce DON after storage and during malting was evaluated. Initial levels of infestation of barley by Fusarium and Alternaria were 85 and 75%, respectively. All storage condition reduced the viability of both molds slightly and significantly for Fusarium. Forced air ventilation at 24 degrees C was the type of storage most effective in reducing the viability of Fusarium, dropping the percentage of infected kernels to 66%. DON levels did not change after 7 months with respect to storage conditions. However, DON levels were lower in malt produced from barley stored at 24 degrees C with or without aeration. On-farm storage of infected barley at elevated temperatures may provide a means to reduce the level of DON in finished malts.

Alternaria↗
PubMed1997

Heliox therapy for pneumothorax: new indication for an old remedy.

STUDY OBJECTIVE: To evaluate a new method of treating pneumothorax: having the subject breathe a helium/oxygen mixture (heliox). METHODS: We conducted a prospective, randomized, controlled study of nine white rabbits weighing 2.5 to 3.5 kg. Experimental pneumothorax was induced in all rabbits with the injection of 20 mL of air into the pleural space. The rabbits then breathed heliox, oxygen, or room air for 2 hours. Chest radiography was performed 5 minutes after induction of pneumothorax, then at 1 and 2 hours. We determined pneumothorax size on the chest radiograph by measuring the interpleural distance and expressing it as a percentage of the hemithorax. RESULTS: At 2 hours the pneumothoraces in the heliox group had diminished from 17.50% +/- .50% to .17% +/- .29%; in the oxygen-breathing group they had diminished from 17.83% +/- 2.25% to .50% +/- .50%; and in the air-breathing group they had diminished from 18.50% +/- 3.12% to 17.33% +/- .25%. The difference between the air-breathing and the oxygen-breathing or heliox-breathing animals was highly significant; no significant difference was found between the oxygen and heliox groups (P<.0001). CONCLUSION: Heliox, a safe and convenient therapy, is as effective as oxygen in reducing the volume of an experimental pneumothorax in rabbits.

Animals↗
PubMed1997

Interleukin-1beta levels in serum and cerebrospinal fluid of children with febrile seizures.

We compared interleukin-1beta (IL-1beta) levels in peripheral blood and cerebrospinal fluid (CSF) of children with febrile seizures with those of children with febrile illnesses without seizures (control). Twenty patients were included in the study, 10 with febrile seizures and 10 with febrile illness not complicated by seizures (control). Blood and CSF were obtained after the patients' admission to the hospital. IL-1beta levels were measured by a specific radioimmunoassay method. No significant differences were observed between mean IL-1beta levels in CSF (4.15 +/- 1.5 pg/ml) and blood (2.92 +/- 2.6 pg/ml) of the patients with febrile seizures group as compared with those in CSF (3.2 +/- 3.2 pg/ml) and blood (3.44 +/- 3.16 pg/ml) in the control group. These results do not support the hypothesis that increased production of IL-1beta or increased diffusion of IL-1beta through the blood-brain barrier is involved in the pathogenesis of febrile seizures in children.

Blood-Brain Barrier↗
PubMed1997

A cluster of serious Escherichia coli infections in a neonatal intensive-care unit.

A cluster of serious Escherichia coli infections was identified among patients in a neonatal intensive-care unit. Infection control staff identified the outbreak because they realized that E coli rarely caused infections in this unit. Pulsed-field gel electrophoresis confirmed that one strain of E coli was transmitted among patients.

Cluster Analysis↗
PubMed1997

Intussusception: a 9-year survey (1986-1995).

BACKGROUND: Acute intussusception has different clinical features in various parts of the world. The goal of this study was to determine the clinical presentation in different ethnic groups in Israel. METHODS: A retrospective chart review of a 9-year period (1985-1995) was carried out at a university medical center. Data extracted included age, sex, ethnic origin, presenting symptoms and signs, the type of enema (barium or air), and the success rate of non-surgical reduction of the intussusception. RESULTS: Ninety patients suffering from intestinal obstruction due to acute intussusception were admitted. The triad of intermittent screaming attacks, lethargy, and vomiting was observed in 37.5% of study subjects. The majority of patients were admitted during the warmer months of the year. The average age of the patients was 7.8 +/- 3.7 months; 70% of them were between the ages of 4 and 9 months and 92.5% under 1 year of age. The female-to-male ratio was 1:2.1. Air enema was superior to the barium enema in achieving reduction (p < 0.01). The incidence in the Jewish population was similar to that observed in other surveys, and twice that found in the Arab population in our region (p < 0.05). CONCLUSIONS: The overall clinical presentation of acute intussusception found in our study does not differ from other studies. The lower incidence of acute intussusception found in the Arab population can be explained by ethnic, genetic, or nutritional factors.

Acute Disease↗
PubMed1997

Visual evoked potentials: a diagnostic test for migraine headache in children.

Visual evoked potentials (VEPs) were performed in a blind fashion in 114 children aged 3 to 17 years with different types of headaches, in order to investigate whether this could be helpful in the diagnosis of migraine versus other types of headaches in children. The study showed that the amplitude between P100 and N2 was significantly larger in children with migraine headaches (mean 19.8 microvol, SD 7.75) compared with other types of headaches (mean 13.1 microvol, SD 7.45). These results suggest that the sensitivity of VEP P100 amplitude to distinguish migraine headaches in children is 67%, the specificity of VEP is 83%, and the predictive positive value is 83%. VEP study might be helpful in work-up of a child with headache, particularly a young child, when signs and symptoms may not be characteristic.

Adolescent↗
PubMed1997

Incidence of recurrent intussusception following barium versus air enema.

The aim of this study was to determine whether using air enema for acute intussusception is related to a higher rate of recurrence than other methods of treatment. A 10-y (1986-95) retrospective study was performed in a university-affiliated paediatric division. The overall recurrence rate for 97 patients with acute intussusception was 7.8% (10% of whom were treated non-surgically). There were no recurrences following the surgical treatment. In matched groups of patients, no risk factors were found for recurrence following air vs barium enema.

Acute Disease↗