PubMed Health⌕ Search

Biomedical subjects

M DeLuca

Publications and source records attributed to M DeLuca.

At least 91 records · Page 5Linked to original sources
PubMed1970

Purification of a specific tRNA by Sepharose-bound enzyme.

A new procedure for measuring binding of tRNA to aminoacyl-tRNA synthetases is described. The purified isoleucyl-tRNA synthetase from Escherichia coli can be covalently bound to activated Sepharose with retention of approximately 40% of the original enzymatic activity. If crude tRNA is passed through a small column of enzyme-Sepharose, isoleucyl-tRNA is preferentially retained. The procedure can be used as a means of purifying specific tRNA molecules.

Carbon Isotopes↗
PubMedDate not supplied

Bioluminescence assays for bile acids in the detection and follow-up of experimental liver injury.

We evaluated the usefulness of recently developed bioluminescence assays for serum bile acids (BA) in the detection and follow-up of experimental liver injury. Liver damage was induced in rats by either D-galactosamine or CCl4, and BA were compared to SGPT and aminopyrine breath test (ABT). In severe liver injury, following D-galactosamine administration, all three methods revealed a significant difference from control values. The degree of abnormality was, however, far greater with SGPT and BA than with ABT. In moderate liver injury, induced by CCl4, the increase in BA was not significant. Values of SGPT and BA showed a very good correlation (3 alpha-OH: r = 0.88; 7 alpha-OH: r = 0.90; 12 alpha-OH: r = 0.83; p less than 0.001 for all correlations). Application of different assays for 3 alpha-OH, 7 alpha-OH and 12 alpha-OH BA allowed us to assess changes in individual BA. A 96-hr follow-up study in D-galactosamine-treated animals showed an increase in BA up to 48 hr and a decrease thereafter. The bioluminescence assays for BA are simple, rapid and require only 10 microliter of serum. Thus, these assays may be the method of choice in detecting and monitoring liver injury in small laboratory animals.

Alanine Transaminase↗
PubMedDate not supplied

Efficacy and safety of excimer laser photorefractive keratectomy and radial keratotomy for bilateral myopia.

PURPOSE: To compare the safety and efficacy of radial keratotomy (RK) and photorefractive keratectomy (PRK) to correct myopia. METHODS: In this randomized, prospective, parallel-group study, 33 patients with bilateral myopia of 1.00 to 5.00 diopters (D) had PRK in one eye and RK in the other. The order of surgeries and treatment assignments were randomized, and the bilateral surgeries were within 1 week for each patient. Data were collected using standardized procedures. Clinical measurements and satisfaction surveys were taken in masked fashion. RESULTS: Eyes that had PRK had statistically significantly more residual myopia than RK-treated eyes at 3, 6, and 12 months postoperatively. This result was attributed to the use of an older excimer laser PRK algorithm that was used at the initiation of the study. No eye that had PRK was overcorrected by 0.50 D or more at 1 year postoperatively, while seven eyes that had RK were overcorrected by at least 0.50 D and six were overcorrected by 1.00 D. Eyes that had PRK had a statistically significant mean shift in the myopic direction between 6 and 12 months postoperatively; two RK eyes had hyperopic shifts of 1.00 D. Three RK eyes and two PRK eyes failed to achieve an uncorrected visual acuity of 20/40 or better by 12 months postoperatively. No eye lost any best corrected visual acuity. CONCLUSION: The two procedures were comparably safe and effective in treating mild to moderate myopia under this protocol. Eyes that had PRK were somewhat more myopic at 1 year after surgery, attributable to the older PRK ablation algorithm. Adoption of newer (current) laser algorithms has improved the predictability of PRK. There was also evidence of reduced variability of outcome in the PRK group. The PRK eyes did not exhibit hyperopic shifts during the 1 year follow-up.

Adolescent↗
PubMedDate not supplied

Ablation zone centration after photorefractive keratectomy and its effect on visual outcome.

PURPOSE: To determine the relation between ablation zone decentration, measured by corneal topography, and visual and refractive outcome, contrast sensitivity, glare, and subjective reports of halos after photorefractive keratectomy (PRK). SETTING: Eye Foundation, University of Missouri-Kansas City School of Medicine. METHODS: This study comprised 70 eyes of 70 patients enrolled into Phase III of the clinical investigation of the VISX 20/20 excimer laser for the correction by PRK of 1.00 to 6.00 diopters of pre-existing sphere. All patients were treated with 5.0 mm ablation zones. Preoperative and postoperative corneal topography in 67 eyes was done using the EyeSys system. Ablation zone decentration was measured relative to the pupillary center at all postoperative visits as determined from the difference or change map. RESULTS: Mean distance between the ablation zone center and the pupillary center was 0.62 mm +/- 0.34 (SD) (range 0.07 to 1.67 mm). Twenty seven of 66 patients with corneal topography (40.9%) had decentrations less than 0.5 mm; decentrations in 6 eyes (9.1%) were 1.0 mm or more from the pupillary center. No correlation was observed between the magnitude of decentration and 1 year postoperative best spectacle-corrected acuity (r = -.04, P = .76), uncorrected acuity (r = -.03, P = .84), or spherical equivalent (r = -.07, P = .59); preoperative uncorrected acuity (r = .04, P = .73) or spherical equivalent (r = -.02, P = .90); or reduction in spherical equivalent (r = .02, P = .89). The magnitude of decentration was correlated with preoperative spectacle-corrected acuity (r = -.37, P = .002). There was no difference in contrast sensitivity, glare, or halos between the cases with less than 0.5 mm of decentration and those with 0.5 mm or more of decentration. CONCLUSIONS: The degree of ablation zone decentration did not affect postoperative Snellen visual acuity or contrast sensitivity.

Adult↗
PubMedDate not supplied

Implantation in children.

With the development of posterior chamber lenses and continuous curvilinear capsulorhexis, and with the availability of viscoelastic agents, the use of intraocular lenses (IOLs) in children is becoming more popular. Since 1982, we have implanted posterior chamber IOLs (PC-IOLs) in the capsular bags of 61 cataractous eyes of 46 children and adolescents. The goal was in-the-bag placement facilitated by the use of a small capsulectomy, and, since 1984, by the use of the continuous curvilinear capsulorhexis. Forty-four cataracts were congenital, 13 were traumatic, and 4 were developmental. Cataract extraction with IOL implantation was performed in 16 (26%) preschool cases (ages 2 through 5), in 31 (51%) child cases (ages 6 through 12), and 14 (23%) adolescent cases (ages 13 through 18). Surgical and postoperative complications were minimal. Visual results were good. Fifty-six percent of preschoolers, 87% of children, and 86% of adolescents achieved 20/40 or better best corrected vision, with 79% of the total cohort achieving 20/40 or better. Overall, 35% achieved an uncorrected visual acuity of 20/40 or better. All but two cases had improvement in best corrected vision; if 20/20 was not attained, the cause was mainly due to deprivation amblyopia. Forty-eight percent of patients were within a diopter of emmetropia.

Adolescent↗
PubMedDate not supplied

Posterior chamber phakic intraocular lens for hyperopia.

PURPOSE: A Phase I U.S. FDA clinical study of a plate haptic posterior chamber phakic intraocular lens (STAAR Surgical Implantable Contact Lens) for treatment of hyperopia was conducted at 4 sites in the United States. The purpose of this report is to assess the short-term safety and efficacy. METHODS: Ten patients with hyperopia between +2.50 and +10.875 D were implanted in one eye each with the posterior chamber plate phakic intraocular lens and were examined at baseline and 1 day, 1 week, 1, 3, and 6 months after surgery. Mean baseline hyperopia was +6.63 D. RESULTS: At 6 months postoperatively, 7 of 10 eyes (70%) had an uncorrected visual acuity of 20/20 or better and 10 of 10 (100%) had 20/40 or better. Eight of ten eyes (80%) had a spectacle-corrected visual acuity within 1 line of baseline; the other two eyes (20%) had an improvement of 3 lines. Mean 6-month postoperative spherical equivalent refraction was +0.20 +/- 0.61D (range, -0.50 to +1.50 D), a reduction of 6.025 D from baseline. Eight of 10 eyes (80%) were within +/-0.50 D of emmetropia, 9 eyes (90%) were within +/-1.00 D, and all eyes (100%) were within +/-1.50 D. No operative or postoperative complications or adverse reactions were observed. CONCLUSIONS: Results support the short-term safety, efficacy, and predictability of the STAAR Surgical Implantable Contact Lens (plate haptic posterior chamber phakic intraocular lens) in the treatment of hyperopia.

Adult↗