Search PubMed⌕ Search

Biomedical subjects

D Wallace

Publications and source records attributed to D Wallace.

171 records · Page 10Linked to original sources
PubMedDate not supplied

Cardiovascular reactivity to video game predicts subsequent blood pressure increases in young men: The CARDIA study.

OBJECTIVE: This study was undertaken to determine the relationship between heightened reactivity of blood pressure (BP) during stress and 5-year changes in blood pressure and hypertensive status, using the CARDIA study. METHOD: A total of 3364 participants (910 white men, 909 white women, 678 black men, and 867 black women), initially 20 to 32 years old and normotensive, were included. Cardiovascular reactivity to psychological stressors (video game and star-tracing tasks for 3 minutes, cold pressor test for 1 minute) was measured in 1987-1988. We then examined reactivity as a predictor of significant BP change (> or = 8 mm Hg, thought to represent a clinically significant increase) over the next 5 years. Logistic regression models were used to control for potential covariates. Significant BP change and the development of hypertension (BP greater than 140/90 or taking medication for hypertension) over the 5-year follow-up were examined in separate analyses. RESULTS: Increased systolic blood pressure (SBP) reactivity to the video game was associated with a significant 5-year SBP increase among the entire cohort, independent of resting SBP (p < .0001). Subsequent analyses showed that this relationship held for men but not for women. Reactivity to the star-tracing task or the cold pressor test did not predict significant BP change. Among black men only, new hypertensives (N = 36) had greater diastolic blood pressure (DBP) reactivity to the video game (p = .01). CONCLUSIONS: Although BP reactivity to all physical and mental stressors used in this study did not consistently predict 5-year change in BP in this young cohort, the results indicate that reactivity to a video game stressor predicts 5-year change in BP and early hypertension among young adult men. These findings are consistent with other studies showing the usefulness of stressors producing a primarily beta-adrenergic response in predicting BP change and hypertension. The results may be limited by the shortened initial rest and recovery periods used in the CARDIA protocol.

Adult↗
PubMedDate not supplied

A novel suture anchor of high-density collagen compared with a metallic anchor. Results of a 12-week study in sheep.

We report the early mechanical properties and histologic findings of a high-density, type I collagen bone anchor. This new anchor was compared with a traditional metallic anchor in a sheep patellar tendon model. No difference in strength of the repair was noted between the two devices at any time point. The insertions on the repaired side approached the strength of the nonoperated side by 12 weeks. Histologic analysis showed that the collagen anchor integrated with the surrounding bone by 6 weeks, and there was little degradation at 12 weeks. The high-density collagen anchor supported tendon healing to bone comparable with that seen with a traditional metallic device, but it has the potential advantage of the anchor being incorporated into bone.

Animals↗
PubMedDate not supplied

Clear lens extraction with intraocular lens implantation for hyperopia.

PURPOSE: Current surgical options for the correction of moderate to severe hyperopia include hyperopic laser in situ keratomileusis (LASIK), phakic intraocular lens implantation and clear lens extraction with intraocular lens (IOL) implantation. We investigate the safety and efficacy of clear lens extraction with IOL implantation to correct hyperopia. METHODS: Phacoemulsification and IOL implantation was performed on 18 eyes of 10 patients. In 16 eyes, the Hoffer-Q formula was used for IOL power calculation and a single IOL was inserted; in the remaining 2 nanophthalmic eyes, the Holladay-II formula was used and two piggy-back IOLs were inserted. RESULTS: Mean preoperative spherical equivalent for distance was +6.17 D (range, +4.25 to +9.62 D). Patients were followed postoperatively for a mean of 10.5 months (range, 4 to 27 mo). Uncorrected visual acuity in all eyes was 20/50 or better with a median uncorrected visual acuity of 20/40 (range, 20/30 to 20/50). Two patients lost 2 lines of spectacle-corrected visual acuity; both of these patients achieved spectacle-corrected visual acuity of 20/30. CONCLUSIONS: Clear lens extraction with IOL implantation is a safe and effective procedure for the correction of moderate to severe hyperopia in the presbyopic age range.

Adult↗
PubMedDate not supplied

Nurses' ability to achieve hyperinflation and hyperoxygenation with a manual resuscitation bag during endotracheal suctioning.

OBJECTIVE: To examine nurses' ability to deliver 1.5 times the ventilated tidal volume at 100% FIO2 with a manual resuscitation bag during endotracheal suctioning. DESIGN: Prospective, descriptive. SETTING: Six adult critical care units in a large university-affiliated medical center. SUBJECTS: One hundred nurses randomly selected from the six adult intensive care units. OUTCOME MEASURES: Nurses' manual resuscitation bag delivery of tidal volume and oxygen, as well as bagging rate, number of breaths delivered, and number of suction catheter passes performed. Patients' heart rate, mean arterial pressure, and arterial oxygen saturation. RESULTS: The mean FIO2 delivered was 0.71 (range 0.24 to 0.97). Oxygen liter flow and nurses' delivered minute ventilation predicted 24% of the variance in FIO2 delivered. Mean bagging rate was 31 compressions per minute. The mean volume per breath delivered was 626 cc, which resulted in achievement of 57% of the standard (1128 cc). Volume achieved was related to patient lung compliance, but not related to nurses' experience, unit of employment, hand strength, or size. CONCLUSIONS: Nurses observed were unable to meet the standard for volume or oxygen delivery. However this did not affect the patient's heart rate, mean arterial pressure, or SaO2.

Adult↗