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Biomedical subjects

M W Burke

Publications and source records attributed to M W Burke.

23 records · Page 2Linked to original sources

Computed measures on computed tomograms of the head.

Measures of average parietal bone mass (APBM) and average parietal skull width (APSW) were developed using automatic image processing techniques and a special polar coordinate system. The precision of the technique is about 2%; the measures are obtained by processing one section of a computed tomographic head scan obtained without special apparatus. In males the APBM does not decrease with age; in females it splits into two groups of age, probably based on postmenopausal changes. The APSW in both males and females increases slightly with age. The clinical utility of the measures is discussed.

Cephalometry↗

Stimulus similarity and order as factors in visual short-term memory in nonhuman primates.

The short-term retention of nonhuman primates for a single sample or for two successively presented samples was assessed in four delayed matching-to-sample experiments with delays of .03, 4, 8, 16, and 32 sec. The single sample tasks included one (Experiment 1) or two (Experiment 4) distractor stimuli in the choice set (matching test). In the two successive samples tasks, the animals matched (reconstructed) the order of presentation of two samples with (Experiment 3) and without (Experiment 2) a distractor stimulus. Also, the possible combinations of eight stimuli (four colors and four shapes) were arranged to test the effects of sample set and choice set similarity. Taken together, analyses of the errors indicated that both sample and choice set similarity were significant sources of confusions in delayed matching. Order errors occurred independently of similarity but were a source of forgetting primarily at the longest delays (16 and 32 sec). Two exceptions to the similarity effect (second response errors in Experiment 3 and errors of an inexperienced group in Experiment 4) were observed. Possible reasons for the exceptions and several implications of these findings for theories of short-term memory are discussed.

Animals↗

Utilization pattern and efficacy of nonsurgical techniques to establish drainage for high biliary obstruction.

PURPOSE: To review the frequency and success of percutaneous and endoscopic techniques in the relief of high biliary obstruction. MATERIALS AND METHODS: A search of the radiologic achieves was performed identifying 70 patients with cholangiographic demonstration of high biliary obstruction defined as proximal to the distal third of the extrahepatic bile duct. Record review determined the frequency and success rates of percutaneous and endoscopic techniques in providing biliary decompression for obstructive jaundice. RESULTS: Endoscopic retrograde cholangiopancreatography was performed in 35 of 70 patients, providing initial endoscopic biliary decompression (EBD) in six patients (two subsequently required percutaneous intervention). Percutaneous biliary drainage (PBD) was attempted in 60 of 70 patients, providing initial decompression in 55 patients. PBD provided decompression after failed endoscopic biliary drainage in 18 of 26 patients. Endoscopic drainage was never attempted after failed percutaneous drainage. Overall EBD success was 23% and overall PBD success was 95%. The complication rate attributed to EBD was 26%; that attributed to PBD was 25%. For those patients who underwent attempts at both EBD and PBD, the complication rate was 16%. CONCLUSION: At an institution with well-developed gastrointestinal medical services and interventional radiologic services, PBD was more successful in providing initial biliary decompression than endoscopic techniques for high biliary obstruction.

Adult↗

Outcome of 350 implanted chest ports placed by interventional radiologists.

PURPOSE: To determine the outcome of implanted chest ports placed by interventional radiologists. MATERIALS AND METHODS: Between June 1993 and July 1996, a single institution placed 350 implanted chest ports in 346 patients by means of the subclavian vein approach. The medical records of these patients were reviewed to determine the outcome of the ports. Ports were implanted for chemotherapy (n = 341), blood transfusion (n = 7), or antibiotics (n = 2). RESULTS: Immediate complications were seven (2%) pneumothoraces and one (0.3%) hematoma. Four (1.1%) of the pneumothoraces necessitated hospital admission and treatment with a chest tube. The remaining three were managed on an outpatient basis. One was successfully treated in the interventional suite by catheter suction. Two pneumothoraces were observed and resolved spontaneously. Mean time of patient follow-up was 260 days (range, 22-929 days). Total time of follow-up was 91,000 catheter days. Delayed complications were 10 cases of thrombosis (2.9% or 0.11 per 1,000 catheter days) of the subclavian vein, four infections (1.1% or 0.04 per 1,000 catheter days), four catheter coiling or tip malpositions (1.1% or 0.04 per 1,000 catheter days), three catheter occlusions (0.9% or 0.03 per 1,000 catheter days), and one catheter leak (0.3% or 0.01 per 1,000 catheter days). Six (1.7%) ports had to be removed as a result of a delayed complication. CONCLUSION: Chest port implantation by interventional radiologists within the radiology department is a successful and safe procedure with complication rates equivalent to, or lower than, those reported in surgical placement series.

Adult↗