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Biomedical subjects

J R Roberts

Publications and source records attributed to J R Roberts.

177 records · Page 10Linked to original sources
PubMed1973

Cranial and spinal meningiomas in a pair of identical twin boys.

A unique set of identical twin boys with spinal and intracranial meningiomas is described. Three distinct spinal tumours and one intracranial one were removed surgically. One intracranial meningioma has been symptomless, so far. The red cell and leucocyte groups of the two patients were found to be identical, and the probability of their being monozygous was estimated from these data as being 0·932 (Appendix).

Adolescent↗
PubMed1972

A case of G M2 gangliosidosis of late onset.

A case of G(M2)-gangliosidosis commencing by the age of 5 years is described, in which hyperacusis, dementia, and fits were prominent clinical features. In addition to the typical ganglioside pattern on thin layer chromatography and the presence of membranous bodies in electron microscopic studies and characteristic histology and histochemistry, there was biochemical evidence of a gross reduction in heat-labile hexosaminidase activity in white blood cells and brain. A younger unaffected sibling showed the same enzyme defect in white blood cells.

Age Factors↗
PubMedDate not supplied

Effect of silica inhalation on the pulmonary clearance of a bacterial pathogen in Fischer 344 rats.

Silica inhalation predisposes workers to bacterial infection and impairments in pulmonary defense function. In this study, we evaluated the effect of pre-exposure to silica on lung defense mechanisms by use of a rat pulmonary Listeria monocytogenes infection model. Male Fischer 344 rats were exposed by inhalation to filtered air or silica (15 mg/m3 x 6 h/day x 5 days/wk). After 21 or 59 days of silica exposure, the rats were inoculated intratracheally with 5 x 10(3) L. monocytogenes. At 0 (noninfected controls), 3, and 7 days after infection, the left lungs were removed, homogenized, and the number of viable L. monocytogenes was counted after an overnight culture at 37 degrees C. Bronchoalveolar lavage (BAL) was performed on the right lungs. Alveolar macrophages (AM) were collected, and the AM production of chemiluminescence (CL), an index of reactive oxygen species generation, was measured. The number of lavagable neutrophils (PMNs) and acellular BAL lactate dehydrogenase (LDH) activity were determined as indices of inflammation and injury, respectively. Pre-exposure to silica for 59 days caused substantial increases in PMN number and LDH activity compared with the air controls, whereas silica inhalation for both 21 and 59 days significantly enhanced the pulmonary clearance of L. monocytogenes compared with air controls. Dramatic elevations were also observed in zymosan- and phorbol myristate acetate (PMA)-stimulated CL production by lung phagocytes recovered from rats pre-exposed to silica for 59 days. These results demonstrate that short-term exposure to inhaled silica particles activates lung phagocytes, as evidenced by increases in reactive oxygen species. This up-regulation in the production of antimicrobial oxidants is likely responsible for the enhancement in pulmonary clearance of L. monocytogenes observed with short-term silica inhalation.

Administration, Inhalation↗
PubMedDate not supplied

Computer-aided learning--a solution for the training needs of users & maintainers of medical equipment.

It can be argued that the strategic role of training and assessment in the use and maintenance of medical equipment for the delivery of safe and efficient healthcare is underestimated. While there has been frequent comment on this issue, the resources provided for this activity are most often insufficient. New methods are required to deliver regular, cost-effective training within the working environment, at the time and place of need. Similarly, the administrative workload has to be automated--and thus reduced--if training is to improve in both frequency and content. Computer-aided learning has had increasing and diverse application in education and training over the past few decades. The sophistication of software tools and the reduced cost of the necessary hardware makes this a viable and appropriate method for application in the field of Clinical Engineering. However, this technology has not yet been fully exploited to provide instruction in the use and maintenance of equipment. In this paper, it is proposed that computer-based training packages should not only be a source of interactive instruction and assessment, but also act as rapidly accessible reference materials or simulators of the actual device for the purpose of fault finding or troubleshooting. Brief details of a sample package are given for training in the use and maintenance of the Siemens Elema Servo Ventilator 900C.

Biomedical Engineering↗
PubMedDate not supplied

Environmental health education in the medical school curriculum.

OBJECTIVE: To collect baseline data of environmental history-taking skills and clinical toxicology knowledge and examine the effects of a lecture on environment on students' history-taking skills. METHODS: An anonymous survey was distributed to third-year medical students prior to an asthma lecture that strongly emphasized environmental triggers. Fourteen questions assessed students' practices and attitudes toward environmental history taking. Six multiple-choice questions assessed clinical toxicology knowledge. Histories written by students were reviewed to determine the group's actual performance before and after a lecture on environmental health. RESULTS: Although students reported that an environmental history was important, few asked about environmental history topics other than smoking and pets. Occupational histories were included for adult patients, but few students asked about parental occupations for pediatric patients. Students recognized the correct antidotal therapy for iron and acetaminophen toxicity but were less proficient at identifying clinical features of lead and organophosphate poisoning. Student history performance, when students were considered as a group, was similar to reported performance, with the presence of pets being the only significant postlecture change in history-taking behavior (P =.01). CONCLUSIONS: Students have a positive attitude toward the need for an environmental history, but in self-reported practice and in actual practice, they explore few major environmental history issues. Data were insufficient to prove that one lecture changed history-taking practices.

Adult↗
PubMedDate not supplied

EEG alpha-biofeedback training: an experimental technique for the management of anxiety.

This paper outlines the design of a specialized alpha-biofeedback system for use in the treatment of anxiety. The relationship of electroencephalographic (EEG) alpha activity to various anxiety states is described, and the rationale for use of alpha-biofeedback training with chronic anxiety patients is explained. Those features of the specialized system, and associated training methods, which are considered essential for this particular application are described and include the following: (1) use of visual feedback and eyes-open training; (2) use of oculomotor influences to facilitate alpha production; (3) encouragement of a passive attitude in the patient by using both verbal instructions and 'low-information' feedback with covert shaping. The training procedures used and the design and function of the instrument are described. The initial clinical results obtained with this equipment are also presented.

Alpha Rhythm↗
PubMedDate not supplied

Generation and characterization of specific antibodies directed to the binding domain of adhesive molecules.

Antibodies were selected in rabbits using as immunogens five synthetic peptides representing the putative cell-binding domains of von Willebrand factor (vWF), fibrinogen (Fn), fibronectin (Fn) and vitronectin. All peptide immunogens contained the sequence Arg-Gly-Asp, thought to be involved in ligand binding to platelet glycoprotein (GP) IIb-IIIa; two of them corresponded to two distinct regions in the alpha-chain of fibrinogen. All anti-peptide antibodies recognized the corresponding immunogen, and four of them, i.e. all except the anti-vitronectin antibody, reacted with the native macromolecule containing the cognate sequence. Each antibody was specific for the corresponding adhesive protein and did not cross-react with any of the others in spite of the presence of the common sequence Arg-Gly-Asp. Two murine monoclonal antibodies reacting with the vWF peptide and with native vWF were used to define the amino acid residues involved in the antigen-antibody interaction. These residues included the glycine and aspartic acid residues of the common Arg-Gly-Asp sequence, as well as other residues specific to the vWF sequence. The antibodies were potent inhibitors of vWF binding to GP IIb-IIIa. The present studies demonstrate that the putative cell binding domains of four adhesive proteins may be part of distinct antigenic epitopes with unique conformations in each of the four GP IIb-IIIa ligands. Moreover, they provide evidence that the Arg-Gly-Asp sequence is the only, or essential, GP IIb-IIIa binding site in the vWF molecule.

Amino Acid Sequence↗