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Biomedical subjects

C M Anderson

Publications and source records attributed to C M Anderson.

241 records · Page 14Linked to original sources
PubMedDate not supplied

Electroencephalogram, bilateral ear temperature, and affect changes induced by lateral visual field stimulation.

Fifteen subjects evaluated while wearing, in random order, four pairs of glasses, two limiting vision to either the left or right lateral visual field (LVF) and two monocular glasses (MGs) limiting vision to either eye, manifested significant differences in laterality indices in the predicted direction for the theta electroencephalogram (EEG) (P < .003) and ear canal temperature (P < .02) between the LVF glasses, but not the MGs. There was a significant correlation between lateral shifts in the theta EEG and ear canal temperature (r2 = .47, F(1,10) = 8.72, P < .015). The LVF glasses induced an absolute difference in anxiety greater (P < .05) than that induced by the MGs. LVF glasses appear to induce a shift in affect and hemispheric dominance.

Adolescent↗
PubMedDate not supplied

Analysis of aberrant behaviour associated with Rett syndrome.

PURPOSE: The purpose of this study was to identify the variables involved in the maintenance of aberrant behaviours associated with Rett syndrome. The occurrence of aberrant behaviours associated with Rett syndrome is typically attributed to biological variables associated with the disorder. In some cases. however, these behaviours have been shown to be sensitive to manipulations of environmental variables (i.e. operant contingencies). However, little research exists regarding the variables involved in the maintenance of these behaviours and the manner in which these variables can be manipulated to effectively reduce the occurrence of these behaviours. METHOD: We conducted functional analyses of the aberrant behaviours exhibited by two females diagnosed with Rett syndrome. Following the functional analyses, treatments were developed to disrupt the relationship between the aberrant response and the reinforcer maintaining it. RESULTS: Results from the functional analysis suggested that in both cases the aberrant behaviours (i.e. hand wringing and hand mouthing) were maintained by automatic reinforcement. Treatment, which included interrupting hand wringing for one individual and preventing hand mouthing for the other participant, resulted in dramatic changes in the levels of aberrant behaviour for both participants. These changes suggested that preventing reinforcement delivery reduced the motivation to engage in aberrant behaviour. CONCLUSIONS: These results suggest that operant variables can be manipulated to influence the occurrence of aberrant behaviour associated with Rett syndrome.

Adolescent↗
PubMedDate not supplied

Development of an implantable artificial lung: challenges and progress.

Unlike dialysis, which functions as a bridge to renal transplantation, or a ventricular assist device, which serves as a bridge to cardiac transplantation, no suitable bridge to lung transplantation exists. Our goal is to design and build an ambulatory artificial lung that can be perfused entirely by the right ventricle and completely support the metabolic O2 and CO2 requirements of an adult. Such a device could realize a substantial clinical impact as a bridge to lung transplantation, as a support device immediately post-lung transplant, and as a rescue and/or supplement to mechanical ventilation during the treatment of severe respiratory failure. Research on the artificial lung has focused on the design, mode of attachment to the pulmonary circulation, and intracorporeal versus paracorporeal placement of the device.

Artificial Organs↗
PubMedDate not supplied

High resolution cine MRI of vessel distension.

OBJECTIVE: We have evaluated the ability of high resolution cine MRI to quantify vessel distension. MATERIALS AND METHODS: Gradient echo imaging was used to acquire high resolution, cardiac-triggered imaging of the ascending aorta in normal volunteers to measure changes in the cross-sectional area of the lumen over the cardiac cycle. The effects of temporal resolution, spatial resolution, and the radiofrequency flip angle on the measurements were investigated. RESULTS: High spatial resolution improved the ability to detect changes in the luminal area. High temporal resolution allowed better tracking of maximal vessel distension. A small flip angle reduced the saturation of slow flow observed in imaging acquired using a large flip angle. CONCLUSION: Our study has demonstrated that high spatial resolution and high temporal resolution can substantially improve the measurement of vessel distension. We have overcome problems of intravoxel dephasing and spin saturation by using high spatial resolution, a short echo time with flow compensation, and a small flip angle.

Blood Vessels↗
PubMedDate not supplied

Clinical practice guidelines for suctioning the airway of the intubated and nonintubated patient.

OBJECTIVE: To provide physicians, physiotherapists, nurses and respiratory therapists with guidelines for the application of airway suctioning. DESIGN: This clinical practice guideline was developed using the model by Browman and colleagues. A working group of representatives from four professional colleges (nurses, physicians and surgeons, physiotherapists and respiratory therapists) and research experts was formed to conduct a systematic review, develop evidence-based recommendations and generate clinical practice guidelines. MEDLINE (1966 to 1998), CINAHL (1982 to 1997) and EMBASE (1974 to 1996) as well as the reference lists of identified articles were searched. Inclusion of articles was determined by at least two group members, and studies were classified according to type. Randomized, controlled; randomized; and nonrandomized crossover and comparative cohort trials were grouped by type of intervention and population for use in the development of recommendations. Other observational and animal studies dealing with adverse effects of suctioning were included in the review but were not used in the development of recommendations. Input on the evidence-based recommendations was sought and incorporated from members of all four professions and from experts on content and methodology. SETTING: Any setting (hospital or home) where suctioning is performed. POPULATION: Intubated and nonintubated adults, infants and children. RESULTS AND CONCLUSIONS: An attempt was made to develop recommendations in each of the subcategories of suctioning techniques addressed by at least one study. In some subcategories, definite recommendations were made (13 in adults, and three in children and infants); in other subcategories, insufficient evidence precluded recommendations. The recommendations addressed the following aspects of suctioning: preoxygenation, hyperinflation, insufflation, hyperoxygenation, hyperventilation, saline instillation, adaptor use, medication use, open and closed systems, and various types of catheters.

Adult↗
PubMedDate not supplied

Assessment of carotid artery stenosis by MR angiography: comparison with x-ray angiography and color-coded Doppler ultrasound.

PURPOSE: To compare magnetic resonance angiography (MRA) with duplex Doppler ultrasound (US) and x-ray angiography (XRA) in the evaluation of the carotid bifurcation. METHODS: The carotid arteries of 61 patients were studied using MRA, US, or XRA; 31 of the patients underwent all three examinations. MRA included both 2D and 3D time-of-flight sequences. Internal and external carotid artery origins were graded normal, mild, moderate, severe, or critical stenosis, or complete occlusion by each of the three studies. RESULTS: Spearman rank correlations of both internal and external carotid artery grades were 0.85 (MRA and XRA), 0.69 (MRA and US), and 0.73 (XRA and US). For internal carotid artery origins only, the correlations were 0.94 (MRA and XRA), 0.85 (MRA and US), and 0.82 (XRA and US). Of discrepancies in internal carotid artery interpretation greater than one grade, seven resulted from US error, three from MRA error, and one from XRA error. A 2-cm partially thrombosed aneurysm detected by US and MRA was missed by XRA. Of 16 possible ulcers on XRA, 11 were noted by MRA, none by US. CONCLUSIONS: MRA and XRA are similar in assessment of carotid bifurcation stenosis. MRA, like US, permits direct visualization of plaque. This preliminary study suggests that MRA may be used to clarify equivocal findings of US, or replace XRA in presurgical planning.

Aged↗