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Biomedical subjects

J C Rudd

Publications and source records attributed to J C Rudd.

6 recordsLinked to original sources
PubMed2004

Microsatellite markers associated with two Aegilops tauschii-derived greenbug resistance loci in wheat.

A new source of greenbug (Schizaphis graminum Rondani) resistance derived from Aegilops tauschii (Coss.) Schmal was identified in W7984, a synthetic hexaploid wheat line and one parent of the International Triticeae Mapping Initiative (ITMI) mapping population. Segregation analysis of responses to greenbug feeding in a set of recombinant inbred lines (RILs) identified a single, dominant gene governing the greenbug resistance in W7984, which was placed in chromosome arm 7DL by linkage analysis with molecular markers in the ITMI population. Allelism tests based on the segregation of responses to greenbug feeding in F2 and testcross plants revealed that the greenbug resistance in W7984 and Largo, another synthetic line carrying the greenbug resistance gene Gb3, was controlled by different but linked loci. Using the ITMI reference map and a target mapping strategy, we have constructed a microsatellite map of Gb3 in a mapping population of 130 F7 RILs from Largo x TAM 107 and identified one marker (Xwmc634) co-segregating with Gb3 and four markers (Xbarc76, Xgwm037, Xgwm428 and Xwmc824) closely linked with Gb3. Deletion mapping of selected microsatellite markers flanking the Gb3 locus placed this resistance gene into the distal 18% region of 7DL. Comparative mapping in the ITMI and Largo x TAM 107 populations using the same set of microsatellite markers provided further evidence that greenbug resistance in W7984 and Largo is conditioned by two different loci. We suggest that the greenbug resistance gene in W7984 be designated Gb7. The microsatellite map of Gb3 constructed from this study should be a valuable tool for marker-assisted selection of Gb3-conferred greenbug resistance in wheat breeding.

Animals↗
PubMed2001

Methicillin-resistant Staphylococcus aureus keratitis after laser in situ keratomileusis.

A 50-year-old man had uneventful bilateral laser in situ keratomileusis (LASIK) for moderate myopia (-4.50 diopters sphere, both eyes). Twelve days postoperatively, he developed unilateral bacterial keratitis. Cultures revealed methicillin-resistant Staphylococcus aureus. The antibiotic regimen was adjusted, and he regained an uncorrected visual acuity of 20/40 and a best spectacle-corrected visual acuity (BSCVA) of 20/15. Bacterial keratitis after LASIK is a rare occurrence. Aggressive use of cultures and fortified antibiotics can prevent significant loss of BSCVA, even when a resistant organism is the cause.

Corneal Topography↗
PubMed2001

Introduction of corneal astigmatism through placement of a scleral fixation ring in eye bank eyes.

PURPOSE: To determine the effect of scleral fixation ring placement in induction of astigmatism by topographic analysis. METHODS: Baseline measurements were used in human eyes from the Utah Lions Eye Bank. In two control eyes, the effect of placing and replacing the eye in the holder was determined. In nine eyes, the effect of placing a 14-mm ring 2.0-mm from the limbus and an 18-mm ring 4.0-mm from the limbus, both in line with and between the rectus muscles, was determined. Induced astigmatism (IA) was determined by Alpins' vector analysis method. RESULTS: Control eyes had a mean variation of 0.26 +/- 0.18 diopters (D) (range, 0.07-0.65). The study eyes had a mean IA of 1.55 D with statistically significant differences noted when comparing 14-mm rings (0.92 +/- 2.00 D) versus 18-mm rings in line with the rectus (3.02 +/- 1.49 D; p = 0.02), with 18-mm rings in line with the rectus muscles (3.02 +/- 1.46 D) versus between the muscles (1.37 +/- 1.14 D; p = 0.03), and all measurements with the 14-mm ring (1.0 +/- 1.49 D) versus the 18-mm ring (2.14 +/- 1.51 D; p = 0.04.). CONCLUSIONS: Significant IA can occur with placement of fixation rings, especially when suture placement is near the insertions of the rectus muscles.

Astigmatism↗
PubMed2000

The role of glaucoma therapy in the need for repeat penetrating keratoplasty.

PURPOSE: To evaluate the effects of medical and surgical therapy for glaucoma in patients requiring repeat penetrating keratoplasty (PK) for endothelial failure. METHODS: Retrospective review of the charts of all patients undergoing repeat PK at the Cornea Service at Wills Eye Hospital between January 1, 1989 and December 31, 1995. Study end-points were time to first rejection episode, number of rejection episodes, time to endothelial failure, and time to regraft. RESULTS: During the study period, 156 patients underwent repeat PK for irreversible endothelial failure. Ninety-four (60.3%) patients had a concomitant diagnosis of glaucoma. Of these 94, 27 (28.7%) underwent glaucoma surgery. The surgically treated group had a significantly higher percentage of patients with at least one rejection episode (55.6%) than those without glaucoma (32.8%; p = 0.04). Similarly, a significant difference existed in the percentage of both medically and surgically treated glaucoma patients having at least one rejection episode (50%) when compared with patients without glaucoma (32.8%; p = 0.04). Rejection episodes occurred sooner in the glaucoma patients than in the nonglaucoma group (18 months vs. 32 months; p = 0.01), irrespective of glaucoma therapy. Grafts in glaucoma patients failed 12 months earlier than those in patients without glaucoma. CONCLUSION: In a selected group of patients who required repeat PK for endothelial graft failure, a majority of patients were found to have a history of glaucoma. Among regraft patients, surgical therapy for glaucoma was found to increase the risk of rejection episodes when compared to patients without glaucoma. The patients with glaucoma were found to be at increased risk for early rejection and failure compared to patients without glaucoma.

Corneal Diseases↗
PubMedDate not supplied

Traumatically ruptured globes in children.

This retrospective study was designed to document the etiology of traumatically ruptured globes in children and to determine the prognostic value of several clinical parameters with respect to visual outcome. Forty-six children 16 years of age and under seen in the emergency room over a 2-year period were found to have full thickness penetration of the globe. Fifty-nine percent of injuries occurred during recreational activities, and 59% occurred outside of the home. Boys outnumbered girls by a 6:1 ratio. For children, initial visual acuity proved to be less valuable as a prognostic indicator with regard to final vision than has been reported in adults. Smaller corneal wounds offered better visual outcomes. Four eyes were enucleated. Ten ruptures (22%) were related to activity involving guns. Four of six BB gun injuries were the result of a ricocheted BB. Visual outcomes in gun-related injuries were particularly poor.

Adolescent↗