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Biomedical subjects

L Richards

Publications and source records attributed to L Richards.

67 records · Page 4Linked to original sources

Calcium balance in paraplegic patients: influence of injury duration and ambulation.

Calcium metabolic balance determinations, which have been done in various clinical and experimental conditions, were applied to the study of 8 spinal cord injured patients receiving a diet with 1600 mg calcium and 85 to 120 gm protein daily. All of the patients had hypercalciuria prior to ambulation. Those with spinal cord injuries of less than 3 months duration (early group) had a calcium balance of -27 mg before ambulation and 235 mg after ambulation. Patients with spinal cord injuries of 6 months or more duration (late group) had calcium balances of 55 mg before ambulation and 175 mg after ambulation. Ambulation significantly decreased the hypercalciuria and modified the calcium balance in a positive direction. Smaller changes were noted in the responses of the late group than in those of the early group. Early ambulation will probably prevent bone loss, calcium stones in the genitourinary tract, and other sequellae of negative calcium balance.

Adolescent↗

Long-term intermittent exposure to sulfuric acid aerosol, ozone, and their combination: alterations in tracheobronchial mucociliary clearance and epithelial secretory cells.

Understanding the effects from long-term exposure to individual ambient air pollutants and mixtures of pollutants is necessary for adequate assessment of health risk. This study examined quantitative and temporal alterations in tracheobronchial mucociliary clearance function and bronchial epithelial secretory cells in rabbits exposed to sulfuric acid (125 micrograms/m3), ozone (0.1 ppm), and their combination for 2 h/d, 5 d/wk for up to 1 yr; some animals were allowed a 6-month post-exposure period. Clearance times were altered during exposure to sulfuric acid or to the mixture, and became progressively slower following the end of exposures to each of the pollutant atmospheres. There was no indication of any interaction in terms of clearance response between the acid and ozone in the group exposed to the mixture. Histological examination of intrapulmonary conducting airways was performed after 4, 8, or 12 months of exposure, and after the post-exposure period. Sulfuric acid resulted in an increase in the number of secretory cells in small airways by 12 months of exposure. Ozone and the mixture resulted in an increase in secretory cell number by 4 months, but the response became attenuated with continued exposure. There was evidence for synergistic interaction between ozone and acid at 4 months, and antagonistic interaction at subsequent times. No inflammation or other biologically significant histological effects were found in any of the animals.

Aerosols↗

Relationship between performance on tests of basic visual functions and visual-perceptual processing in persons after brain injury.

OBJECTIVE: In this correlational study of adults receiving occupational therapy who sustained a cerebrovascular accident (CVA), the relationship between basic visual functions (including acuity, visual field deficits, oculomotor skills, and visual attention or scanning) and higher level visual-perceptual processing skills (e.g., visual closure and figure-ground discrimination) was investigated. METHOD: Thirty adults who sustained CVA and 20 adults without a history of CVA were given a basic visual function screening and the Motor-Free Visual Perception Test (MVPT). Scores on the vision screening and the MVPT were correlated statistically. RESULTS: A Pearson product-moment correlation analysis produced a correlation of r = .75 between vision screening scores and scores from the MVPT. CONCLUSION: These results suggest that a positive relation exists between basic visual functions and visual-perceptual processing skills. Further, the results suggest that evaluation of visual-perceptual processing skills must begin with assessment of basic visual functions so that the influence of these basic visual functions on performance in more complex tests can be taken into consideration.

Accommodation, Ocular↗