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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
PubMed1994

Melanoma metastatic to the bronchus: radiologic features in two patients.

Two patients with cutaneous melanoma metastatic to the bronchus are described. Chest radiographs revealed only indirect signs of bronchial obstruction. Computed tomography (CT) clearly demonstrated the intraluminal lesion. Magnetic resonance (MR) imaging signal characteristics were not specific for melanoma.

Aged↗
PubMed1993

Use of biologic markers for toxic end-points in assessment of risks from exposure to chemicals.

Biologic markers are familiar tools for monitoring human absorption of, and reaction to, potentially toxic chemicals. The concept of applying biologic markers to the risk assessment process is a natural, but more recent, development and the principles remain to be fully elaborated. Biologic markers may be measurements of exposure, of effects, of genetic or induced sensitivity or of disease. The ideal biologic marker for risk assessment purposes is a quantitative measurement of a chemical, biochemical, functional or morphological change in the system that is initiated by a chemical and which results in pathologic change and overt toxicity. It follows that some understanding of the mechanism of toxicity and of dose-response relationships are pre-requisite for selection of suitable biologic markers for use in risk assessment. Where biologic markers for toxicity are common between mammalian species, extrapolation of data for quantitative risk assessment purposes becomes more reasonable. In the field of carcinogenesis, some DNA and protein adducts have been proposed as biologic markers for assessment of risk associated with exposure to genotoxic carcinogens. However, less progress is evident in relation to other toxic end-points including those for pulmonary, reproductive, immuno- and neuro-toxicity, despite intensive efforts.

Biomarkers↗
PubMed1993

Iron deposition in cranial bone marrow with sickle cell disease: MR assessment using a fat suppression technique.

Thirteen patients with sickle cell disease (SCD) undergoing transfusion therapy and 8 control patients were examined by magnetic resonance imaging to discriminate bone marrow change due to iron deposition from hematologic marrow hyperplasia. Using T1-weighted spin echo images, only two subjects showed extremely low signal intensity marrow compatible with iron deposition. However, using T2-weighted fast spin echo images with fat suppression, cranial bone marrow in SCD patients with transfusion therapy showed considerably lower signal than that of controls. The main cause of marrow signal decrease in SCD patients with transfusion therapy was considered to be iron deposition due to repeated transfusion therapy rather than red marrow hyperplasia.

Adolescent↗
PubMed1991

The Word Association Implications Test.

Three experiments (N = 144 college students) tested and documented the relationship between incidental learning of diagnostic schemata with performance on the Word Association Implications Test (WAIT). Moreover, Experiment 1 showed that instruction in diagnostic cues did not improve WAIT scores, although an incentive did. Experiment 2 supported the "developing schemata" concept by showing that subjects need to interpret WAIT protocols before they can generate possible diagnostic clues. Experiment 3 showed that inductive reasoning and viewing the task as more play- and game-like (vs. work- and test-like) predicted WAIT scores over and above the influence of incidental learning of schemata, in sum, results suggest that an heuristic discovery-oriented approach is most successful in learning "to read between the lines" of word associations. Discussion addresses the value of heuristic versus algorithmic approaches to the learning of personality assessment.

Journal Article↗
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↗