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Biomedical subjects

A E Robinson

Publications and source records attributed to A E Robinson.

At least 19 recordsLinked to original sources
PubMed1990

Cerebral blood flow mapping using stable xenon-enhanced CT in sickle cell cerebrovascular disease.

The cerebral blood flow (CBF) of 25 patients with sickle cell cerebrovascular disease (SCCVD) was examined using a Xenon-CT flow mapping method. Brain CT and MR findings were correlated with those of the Xenon-CT flow studies. CBF defects on Xenon-CT correlated reasonably well with the areas of cortical infarctions on the MR images, but in 27% of the cases, flow defects were slightly larger than the areas of infarctions on the MR images. In deep watershed or basal ganglia infarctions, abnormal CBF was noted about the cerebral cortex near infarctions in 72% of the patients, regardless of infarction sizes on the MR images. However, decreased CBF was recognized in 4 of the 9 children whose MR images were virtually normal. Thus, the extent of flow depletion cannot be predicted accurately by MR imaging alone. Xenon-CT flow mapping proved a safe and reliable procedure for evaluation of the CBF of patients with SCCVD. Although this study is preliminary, it may have a potential in selecting patients for hypertransfusion therapy, as a noninvasive test and for following children with SCCVD during their therapy. Careful correlation of results of CBF with those of MR imaging or of CT is important for objective interpretations of flow mapping images.

Adolescent↗
PubMed1990

MR imaging of pancreas in cystic fibrosis.

The pancreatic regions of 18 patients with cystic fibrosis were analyzed with a 1.5 Tesla MR unit. Signal intensity of the pancreas was correlated with clinical data and ultrasound. A hyperintense pancreas on T1-weighted image was consistent with fatty replacement of pancreatic insufficiency. A pancreas of normal soft tissue intensity was found in two asymptomatic and one symptomatic patient. A very hypointense pancreas on any pulse sequence was considered to be an intermediate stage of pancreatic degeneration.

Adolescent↗
PubMed1990

Degenerative lumbar spine disorders in gradient refocused echo axial magnetic resonance images.

The axial images of 58 lumbar disks having degenerative disorders imaged by gradient refocused echo (GRE) and spin echo (SE) magnetic resonance imaging (MRI) pulse sequences at high field strength were compared for diagnostic quality. The vacuum phenomenon, calcified disk, and bony hypertrophic changes were better demonstrated by GRE images than by SE images due to magnetic susceptibility effect. Axial GRE images are therefore useful adjuncts to SE images for effective MRI of degenerative lumbar spine disorders at high field strength.

Humans↗
PubMed1990

Variations in gastrointestinal melanoma metastases.

In 10 patients with gastrointestinal metastases from cutaneous malignant melanoma, metastases to the stomach were found in 2, the small bowel in 9, and the large bowel in 3. Gastric metastases typically appeared as target lesions. However, the morphology of secondary melanoma deposits to the small and large intestine varied significantly, target lesions being only one possible manifestation. Less common appearances of gut metastases were found in 4 patients. One presented atypically with matted loops of distal ileum resulting in prolonged stasis of barium in the affected areas. In 3 patients, infiltrative and stenotic lesions were found in the distal ileum, terminal ileum and cecum. One stenotic lesion of the distal ileum was accompanied by multiple small polypoid lesions more proximally, and the cecal lesion was ulcerated. Six of the patients presented with polypoid and, occasionally, ulcerated and multiple secondary melanoma deposits. Possible causes for variations in morphology are discussed.

Gastrointestinal Neoplasms↗
PubMed1989

Standard setting and protection of human health and safety.

Human health and safety are determined by the behavior and performance of the individual, or of a piece of equipment, under the prevailing conditions. Setting health or safety standards, which will define a set of conditions to provide protection, requires consideration of many factors, including the level of protection required and the collection and assessment of factual information. The purpose of the paper is to identify and discuss the elements of the standard-setting process and the major issues likely to be associated with it. Occupational exposure values and other initiatives to provide protection of human health from the potential effects of chemicals in Canada are reviewed in the context of recent initiatives and current pressures for change.

Accident Prevention↗
PubMed1988

Giant aneurysms of bilateral internal carotid arteries in a child.

Aneurysms in the petrous or cavernous portion of the internal carotid artery in childhood are extremely rare. Only two such cases have been previously reported. We present a case of bilateral giant intrapetrous aneurysms in a young female. CT was especially helpful in evaluating the absolute size of these aneurysms. This case is unique in that we demonstrated the temporal evolution of internal carotid aneurysms on follow-up angiography.

Carotid Artery, Internal↗
PubMed1988

Breast neoplasms: duplex sonographic imaging as an adjunct in diagnosis.

Sonographic breast imaging has been useful in the differentiation of cystic from solid masses. It has also been helpful in the characterization of palpable breast masses in the absence of corresponding abnormalities. The authors undertook a prospective study that incorporated pulsed Doppler analysis into sonographic real-time imaging of solid breast masses. Thirty-eight patients were examined. In 12 of the patients there were positive Doppler signals, while in 26 patients there were no Doppler signals. The 12 patients showing positive Doppler signals proved to have infiltrating ductal carcinoma, while the 26 patients with negative Doppler signals proved to have benign breast disorders. Pulsed Doppler analysis as a supplement to sonographic real-time imaging shows promise for the identification of breast carcinoma.

Adult↗
PubMed1987

Effect of cross linkers on the bacteriorhodopsin photocycle.

A general behavior of bacteriorhodopsin in purple membranes from Halobacterium halobium has been observed upon modification resulting in cross-linking of carboxyl and lysine groups. The rise of the M-intermediate contained two components with approximately 50-50% intensity; its decay showed three components with approximately 25-50-25% intensity respectively in a pH range of 5-9. The significance of these remarkably similar data with respect to the proton translocation mechanism in bacteriorhodopsin is that chemical modification allows us to conclude that disturbing parts of the hypothetical "proton conducting chain" does not inhibit proton translocation.

Bacteriorhodopsins↗
PubMed1987

Eosinophilic granuloma of the cervical spine without vertebrae plana.

A case of eosinophilic granuloma of the cervical spine is described. Cervical radiography and computed tomography demonstrated destruction of pedicles and posterior portions of the neural arch. Vertebral body heights were essentially preserved and the importance of this finding is underscored. Computed tomography played an important role in evaluating the extent of this disease.

Cervical Vertebrae↗