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Biomedical subjects

S Robison

Publications and source records attributed to S Robison.

5 recordsLinked to original sources
PubMed2000

Quantitative 3D maxillary arch evaluation of two different infant managements for unilateral cleft lip and palate.

OBJECTIVE: A two-institution retrospective study was undertaken to determine whether two different prepalatoplasty protocols quantitatively affect maxillary arch morphology in infants with complete unilateral cleft lip and palate (UCLP). DESIGN: Serial maxillary dental casts, obtained at regular intervals through the first 18 months of life from preintervention until palatoplasty were evaluated quantitatively using computer-assisted three-dimensional digitization and analysis for three populations: institution 1 (protocol 1), institution 2 (protocol 2), and unaffected individuals (neither cleft nor treatment). Sequential UCLP patients from institution 1 were matched for age and initial alveolar cleft width, sex and cleft side having been demonstrated to be nonsignificant, with UCLP patients from institution 2 and to unaffected individuals for age for the analysis. SETTING: Both treatment institutions are well-established regional interdisciplinary cleft centers. Institution 1 is located in a tertiary, academic children's hospital in a metropolis within a primarily agrarian region of the Midwest; institution 2 is a freestanding private clinic located in a small city within a primarily agrarian region of an eastern state; the unaffected population is a historic archive acquired in the 1930s. Data acquisition (model digitization) and computer processing were performed at institution 1. PATIENTS: Eighty-five casts of 28 infants from institution 1, 106 casts of 31 infants from institution 2, and 68 casts of 29 unaffected infants were analyzed. All infants had alginate impressions taken prior to intervention and at several additional 6-month intervals after that, consistent with each institution's treatment protocol. INTERVENTIONS: At institution 1, patients with UCLP underwent lip adhesion and placement of a passive alveolar molding plate at 7 weeks of age, definitive cheiloplasty at 7 months of age, and one-stage palatoplasty at 14 months of age. At institution 2, patients with UCLP underwent definitive cheiloplasty at 3 months of age, had no maxillary orthopedics, and had vomer flap hard palate repair at 12 months of age and soft palate repair at 18 months of age. MAIN OUTCOME MEASURES: The outcome measures included directly digitized (cleft segment and hemialveolar ridge lengths) and derived (alveolar base width, alveolar cleft gap, maxillary frenum-alveolar base perpendicular angle, and rates of change over time of digitized cleft segment and hemialveolar ridge lengths) features. The data were assessed by comparing simple linear regression lines and an unpaired, two-tailed t test. RESULTS: Prior to initiating therapy, there were no statistically significant differences between the two populations with clefts. However, both populations with clefts differed significantly from unaffected individuals (p < .001), with increased maxillary base widths and larger perpendicular/frenum angles. At the time of palatoplasty, the two populations with clefts had statistically significant differences between them in the maxillary base width (p < .01) and the cleft gap distance (p < .05). The base width of institution 1 did not differ significantly from that of widths of unaffected children, and that of institution 2 was significantly less, although the latter had already received first-stage palate repair. Alveolar segment growth rates were similar for the greater and lesser segments, respectively, and the left side hemialveolus of both groups. The growth rate for the noncleft side hemialveolus of institution 2 exceeded (p < .05) that of both institution 1 and unaffected patients. CONCLUSION: Two different regimens for the initial management of UCLP can significantly affect maxillary alveolar arch growth with respect to the treatment used and in comparison with unaffected controls.

Age Factors↗
PubMed2000

The effect of case management on the costs of health care for enrollees in Medicare Plus Choice plans: a randomized trial.

OBJECTIVE: To measure the effects of case management on an older population's costs of health care. DESIGN: A 1-year randomized controlled trial. SETTING: Multiple sites of care in San Francisco, California. PARTICIPANTS: Patients aged 65 or older of primary care physicians in a large provider organization bearing financial risk for their care (n = 6409). INTERVENTION: Screening for high risk and provision of social work-based case management. OUTCOME MEASURES: Volume and cost of hospital, physician, case management, and other health-related services. RESULTS: The experimental group used more case management services than the control group (0.09 vs. 0.02 months per person, P<.001). The experimental group's average total payments for health care were slightly lower ($3148 vs $3277, P = .40). CONCLUSIONS: This study provides no statistically significant evidence that social work-oriented case management reduces the use or the cost of health care for high-risk older people. Other potentially favorable effects of this type of case management need to be evaluated, as do the effects of other types of case management.

Aged↗
PubMed1989

Temperature dependence of adriamycin-induced DNA damage in L1210 cells.

We report alkaline elution experiments that reveal the temperature dependence of DNA lesions, both single-strand breaks and DNA-protein cross-links, in L1210 cells exposed to Adriamycin. DNA damage, which at 37 degrees C is equivalent to several hundred rads of ionizing radiation exposure, diminishes as the temperature of drug exposure is lowered. At all temperatures below about 15 degrees C no DNA damage is detectable in L1210 cells exposed to Adriamycin, even at relatively high doses. The low temperature inactivity is not due to a redistribution of intracellular drug since at both 37 and 0 degrees C there is a high concentration of Adriamycin in both nuclear and cytoplasmic locations. The temperature profile for DNA damage parallels the profile for cytotoxicity, i.e., at low temperature, the drug is completely inactive as a cytotoxic agent (P. Lane, P. Vichi, D. L. Bain, and T. R. Tritton, Cancer Res., 47:4038-4042, 1987). Thus, DNA breaks and cell kill appear to be correlated with one another. However, when we examined DNA lesions in nuclei isolated from L1210 cells we found that the low temperature inability to sustain Adriamycin-induced single-strand breaks or DNA-protein cross-links was absent. In nuclei, then, the drug can provoke DNA damage at low temperature, while in whole cells it cannot. Topoisomerase II, an enzyme implicated in catalyzing DNA lesions in cells exposed to intercalating agents, retains its catalytic activity both to unknot P4 DNA at 0 degrees C, and to be induced by drug to alter the release of pBR322 supercoils, so a low temperature inactivation of this enzyme cannot explain the results. We propose that intact L1210 cells have a regulatory factor which controls DNA damage, possibly through topoisomerase II, but which is lost when nuclei are isolated.

Animals↗