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Biomedical subjects

J L Davis

Publications and source records attributed to J L Davis.

At least 73 records · Page 4Linked to original sources
PubMed1997

Removal of retained lens fragments after phacoemulsification reverses secondary glaucoma and restores visual acuity.

PURPOSE: The purpose of the study is to evaluate the effect of vitrectomy on secondary glaucoma and visual acuity outcomes in patients with retained lens fragments after phacoemulsification. METHODS: A retrospective analysis of 126 patients who had vitrectomy for retained lens fragments after phacoemulsification during the 3-year period between January 1, 1993, and December 31, 1995. RESULTS: Glaucoma, defined as an intraocular pressure of greater than or equal to 30 mmHg, occurred in 42 (36.8%) of 114 patients before vitrectomy and in 4 patients (3.2%) of 126 after vitrectomy. There were no differences in the rates of persistent glaucoma regardless of the intervals between cataract surgery and the vitrectomy: less than or equal to 1 week, 2 patients (4.1%); greater than 1 week to less than or equal to 4 weeks, 1 patient (2.5%) and greater than 4 weeks, 1 patient (2.6%). The visual acuity was 20/40 or better in 13 patients (11.4%) before vitrectomy and in 75 patients (59.5%) after vitrectomy. The rates of visual acuity 20/40 or better also were similar for all intervals: less than or equal to 1 week, 29 patients (59.2%); greater than 1 week to less than or equal to 4 weeks, 22 patients (56.4%) and greater than 4 weeks, 24 patients (63.1%). CONCLUSIONS: Vitrectomy for removal of retained lens fragments reduces secondary glaucoma and yields favorable visual acuity outcomes. In eyes with elevated intraocular pressure, early vitrectomy generally is recommended, but delayed vitrectomy also has favorable outcomes.

Adult↗
PubMed1997

A comparison of Mohs micrographic surgery and wide excision for the treatment of atypical fibroxanthoma.

BACKGROUND: Atypical fibroxanthoma (AFX) is an uncommon spindle cell neoplasm occurring most often in actinically damaged skin of elderly patients. This tumor has invasive potential, may recur locally after excision, and rarely metastasizes. To conserve tissue and improve the likelihood of cure, Mohs micrographic surgery (MMS) has been used for treatment. OBJECTIVE: We review and discuss the Mayo Clinic experience treating AFX with MMS and retrospectively compare the clinical outcome with that in a similar cohort of patients treated with wide local excision (WE). METHODS: The medical records of 45 patients were reviewed at three Mayo Clinic practices. Follow-up data were available for 44 patients: 19 treated with MMS and 25 with WE. RESULTS: In patients treated with MMS, there were no recurrences after a mean follow-up of 29.6 months. There were three first recurrences in 25 patients (12%) treated with WE after a mean follow-up of 73.6 months. One patient had a single local recurrence, and two patients each had two local recurrences. Parotid node metastasis eventually developed in one of the patients with two local recurrences, so that the regional metastatic rate in this series was 4% (1 in 25 patients). CONCLUSION: Microscopic control of the surgical margins with MMS in the treatment of AFX results in a lower recurrence rate than that with WE and conserves normal tissue.

Age Distribution↗
PubMed1997

Treatment outcomes in a 10-year study of endogenous fungal endophthalmitis.

BACKGROUND AND OBJECTIVE: To review prevalence of organisms, associated factors, and treatment outcomes from one medical center's 10-year experience managing culture-proven endogenous fungal endophthalmitis (EFE). PATIENTS AND METHODS: The authors retrospectively reviewed the microbiology and corresponding clinical records of patients diagnosed as having culture-proven EFE at the Bascom Palmer Eye Institute during a 10-year period. RESULTS: Culture-proven EFE occurred in 20 eyes of 18 patients. Candida species occurred in 17 of 20 eyes (85%), and Aspergillus species occurred in 3 of 20 eyes (15%). The most common association was long-term intravenous line placement, which was present in 12 patients (67%). Whereas 12 patients (67%) had a history of recent hospitalization, only 2 (11%) had a documented history of systemic fungal infection. After initial examination, only 2 patients had a systemic culture positive for a fungal organism (none had a positive blood culture). Treatment after initial examination included pars plana vitrectomy in 17 of the 20 eyes (85%), intravitreal amphotericin B in 19 eyes (95%), and systemic antifungal medication in 16 eyes of 15 patients. Thirteen of the 17 eyes (76%) with Candida endophthalmitis and 0 of 3 eyes with Aspergillus endophthalmitis achieved visual acuity of 20/400 or better. CONCLUSION: The most common cause of culture-proven EFE at the authors' institution is Candida species. The overall visual outcomes were more favorable for Candida cases than they were for Aspergillus cases. In the treatment of patients with marked vitreous infiltrates from EFE, pars plana vitrectomy, intravitreal amphotericin B injection, and administration of appropriate systemic antifungal medication (fluconazole for Candida) are generally recommended.

Adult↗
PubMed1996

Endophthalmitis in patients with retained lens fragments after phacoemulsification.

PURPOSE: To review the treatment and outcomes of patients presenting with concurrent endophthalmitis and retained lens fragments after phacoemulsification. METHODS: A retrospective chart review was conducted on patients presenting with culture-proven endophthalmitis and retained lens fragments after phacoemulsification between 1990 and 1994. RESULTS: Five patients were identified with culture-proven endophthalmitis and retained lens fragments after phacoemulsification. In all patients, coagulase-negative staphylococci were cultured from the vitreous fluid. One patient also had positive cultures for Proteus mirabilis and Escherichia coli. The interval between cataract surgery and treatment ranged from 5 days to 6 months. Echography was beneficial in showing retained lens fragments in five of five patients when media opacities obscured the view of the fundus. Four patients had vitrectomy and removal of retained lens fragments during their initial treatment. The fifth patient was treated with intravitreal antibiotics alone and continued to have marked inflammation, eventually requiring vitrectomy for removal of the retained lens fragments. A final visual acuity of 20/400 or better was achieved in four of the five patients. CONCLUSIONS: Patients may present with endophthalmitis in the setting of retained lens fragments after phacoemulsification. In such cases, the preferred initial management may be pars plana vitrectomy, removal of retained lens fragments, and injection of intraocular antibiotics. In eyes with endophthalmitis and opaque media, echography is a useful screening modality.

Aged↗
PubMed1996

The effect of postruminal amino acid flow on muscle cell proliferation and protein turnover.

An experiment was conducted to characterize the effects of postruminal administration of casein, glutamine, cornstarch, and water on protein turnover and in vitro muscle cell proliferation. Four MARC III steers (205 kg) were fed a protein-restricted bromegrass hay-based diet (2.86 Mcal of DE/kg and 13.6 g of N/kg). Using a 4 x 5 Latin square arrangement balanced for residual effects, casein and glutamine, equal to 50% of basal dietary nitrogen intake, cornstarch, isocaloric with casein infusion, or an equal volume of water was continuously infused into the abomasum of steers. Blood samples, collected every 2 h for 24 h after 7 d of infusion, were tested for the effect on cell cycle kinetics and myotube protein turnover. Urine and feces were also collected for 4 d after blood sampling for nitrogen balance and fractional skeletal muscle degradation. The mitogenic activity and ability of serum to influence rate of myoblast proliferation in a dose-dependent manner was influenced (P < .05) by infusate: casein > cornstarch > glutamine = water. Abomasal infusion of casein and cornstarch increased (P < .05) in vitro muscle protein synthesis and decreased (P < .05) in vitro muscle protein degradation, whereas abomasal glutamine infusion only increased (P < .05) in vitro muscle protein synthesis. Abomasal glutamine infusion decreased (P < .05) fractional skeletal muscle protein degradation and synthesis; however, fractional muscle protein accretion tended to increase due to a greater decline in fractional muscle protein degradation. In contrast, abomasal casein infusion increased (P < .05) fractional skeletal muscle protein synthesis, breakdown, and accretion. These results suggest that muscle hypertrophy may be regulated by serum constituents whose activity is affected by postruminal amino acid flow.

Amino Acids↗
PubMed1995

Branch retinal arterial occlusions in multifocal retinitis with optic nerve edema.

OBJECTIVE: To determine the natural history and visual prognosis of patients with branch retinal arterial occlusions secondary to multifocal retinitis. METHODS: Cases were reviewed for seven patients who exhibited multifocal retinitis and branch retinal arterial occlusion. The average age of the patients was 27 years (age range, 14 to 19 years). RESULTS: Six patients had systemic illnesses associated with their ocular findings. Four patients were scratched by a cat or exposed to a cat with fleas within 1 month of symptoms. Three of these patients were tested and had positive cat-scratch disease titers. At presentation, five patients complained of a scotoma, and two noted blurred vision. On examination, visual acuity was 20/25 or better in all but one eye. Five patients had vitritis, which was bilateral in three. Four patients exhibited optic nerve edema, which was bilateral in two. White intraretinal infiltrates were present in all patients, and were bilateral in five. The six patients who were examined within 1 week of symptoms had a white retinal infiltrate at the site of vascular occlusion. The retinal findings resolved in 2 to 6 weeks and did not recur. The final visual acuity was 20/20 OU in all patients. CONCLUSIONS: Branch retinal arterial occlusions represent a complication of multifocal retinitis and idiopathic optic nerve edema. The arterial occlusions are probably caused by a focus of retinitis. This self-limited disorder has an excellent visual prognosis and may be related to cat-scratch disease.

Adolescent↗
PubMed1995

Silicone oil in repair of retinal detachments caused by necrotizing retinitis in HIV infection.

OBJECTIVE: To evaluate the safety and efficacy of 1000- and 5000-centistoke silicone oil as retinal tamponades for the treatment of retinal detachments secondary to necrotizing retinitis in patients with human immunodeficiency virus (HIV) infection. DESIGN: A prospective observational study. SETTING: Community and university-based ophthalmology clinics. PATIENTS: Three hundred fifty patients with HIV infection, who had 407 eyes with retinal detachments secondary to necrotizing retinitis. INTERVENTION: Vitrectomy surgery for retinal detachment with 1000- or 5000-centistoke silicone oil as the retinal tamponade. OUTCOME MEASURES: Efficacy was measured both by anatomic success (defined as complete retinal attachment or macular attachment) and by visual acuity success (defined as preservation of visual acuity or ambulatory vision). Safety was determined by the rate of complications, including abnormal intraocular pressure and corneal and lens opacification. RESULTS: At the last follow-up examination, the retina was completely attached in 287 (73%) of 393 eyes, the macula was attached in 370 eyes (94%), 268 eyes (68%) had ambulatory vision, and visual acuity was preserved in 219 (56%) of 388 eyes. Corneal opacification, hypotony, and silicone oil emulsification were present in 4%, 2%, and 1% of eyes, respectively. One eye had elevated intraocular pressure. Of the 57 patients who had both eyes treated, 35 died, of whom four (11%) had nonambulatory vision in both eyes. Of the 293 patients who had one eye treated, 122 died, of whom 44 (36%) died with nonambulatory vision in the treated eye. The median time to cataract was 192 days; to nonambulatory vision, 474 days; and to death, 204 days. CONCLUSIONS: Silicone oil repair of retinal detachments in necrotizing retinitis is an efficacious and safe procedure that delays or prevents loss of vision in advanced HIV disease.

Adult↗
PubMed1995

Pars plana vitrectomy for chronic pseudophakic cystoid macular edema.

PURPOSE: We determined the efficacy of pars plana vitrectomy in a series of patients with chronic pseudophakic cystoid macular edema. METHODS: Clinical records were reviewed on 24 consecutive patients who underwent pars plana vitrectomy in one eye for chronic pseudophakic cystoid macular edema. All 24 patients had failed to improve on medical therapy and had preoperative evidence of either vitreous adhesions to anterior segment structures (23 eyes) or iris capture of the intraocular lens (one eye). RESULTS: The mean, best-corrected Snellen visual acuity was 20/190 preoperatively (median, 20/200; range, 20/50 to 3/200) and 20/52 postoperatively (median, 20/40; range, 20/20 to 20/400 [P < .0001]). Visual acuity improved postoperatively in all 24 eyes, with a mean improvement of 4.7 Snellen lines (range, one to eight lines). There was no highly significant difference in preoperative visual acuity (P = .41) or postoperative visual improvement (P = .17) between patients with anterior as opposed to posterior chamber intraocular lenses. Longer time interval from cataract surgery to vitrectomy did not correlate with less postoperative visual improvement. CONCLUSIONS: In pseudophakic eyes with chronic cystoid macular edema, vitreous adhesions to anterior segment structures, and visual loss that is unresponsive to medical therapy, pars plana vitrectomy with removal of these vitreous adhesions may lead to improved visual acuity.

Aged↗
PubMed1995

Idiopathic retinal vasculitis, aneurysms, and neuro-retinitis. Retinal Vasculitis Study.

PURPOSE: The authors describe the clinical feature of ten patients with a new syndrome characterized by the presence of retinal vasculitis, multiple macroaneurysms, neuro-retinitis, and peripheral capillary nonperfusion. METHODS: The authors evaluated ten patients identified to have clinical features compatible with the syndrome of idiopathic retinal vasculitis, aneurysms and neuroretinits (IRVAN). Clinical examination findings, sequential funds photographs (when available), fluorescein angiograms, systemic investigations, response to therapy, and visual outcomes were reviewed. RESULTS: Seven eyes of four patients sustained a marked decrease in visual acuity of 20/200 or worse. Visual loss was due to a combination of an exudative maculopathy and sequelae of retinal ischemia. Capillary nonperfusion was seen in all ten patients and was severe enough to warrant panretinal laser photocoagulation in six patients. Systemic investigations were uniformly noncontributory. Oral prednisone appears to have little beneficial effects on patients with this disorder. CONCLUSIONS: Patients with IRVAN have characteristic retinal features that readily identify this syndrome. An increased awareness of this rare syndrome may help to identify sight-threatening complications at an earlier stage. The authors caution against extensive medical investigations.

Adult↗
PubMed1995

The research school of Marie Curie in the Paris faculty, 1907-14.

As the most famous woman scientist of the twentieth century, there has been no shortage of books and articles on the life and career of Marie Curie (1867-1934). Her role as director of a laboratory-based research school in the new scientific field of radioactivity, a field which embraced both chemistry and physics, however, has never been examined. In recent years, there has been a growing interest in the question of research schools, and Morrell, Ravetz, Geison, and Klosterman, amongst others, have written on this subject. Using, in part, the methodology of Morrell, this paper investigates the role of Marie Curie as a school director in the Paris Faculty in the years 1907-14, examining the work and characteristics of her school and assessing her effectiveness as a director.

Academies and Institutes↗
PubMed1995

Interpretation of intraocular and serum antibody levels in necrotizing retinitis.

BACKGROUND: Intraocular antibodies have been measured as a diagnostic aid in necrotizing retinitis but interpretation of results may be difficult. METHODS: Vitreous or aqueous and serum immunoglobulin G antibodies to toxoplasmosis, cytomegalovirus, herpes simplex virus I and II, and varicella zoster virus were subjected to enzyme-linked immunosorbent assay in 27 patients with necrotizing retinitis and 15 control patients. A quotient was derived quantitating the amount of excess antibody in the eye compared to serum. Different interpretative rules were analyzed to determine which yielded the highest sensitivity and specificity. RESULTS: The highest intraocular antibody relative to serum among the 4 antibodies correctly predicted the final clinical diagnosis in 21 of 27 patients, for a sensitivity of 78% and a specificity of 90%. Interpretive rules that relied on a high numeric value of the antibody quotient or did not consider the relative ranking of the four antibody quotients were less sensitive and specific because multiple antibodies were detected in most eyes. The technique was safe and rapid. CONCLUSION: Interpretation of antibody titers in intraocular fluids is facilitated by testing several relevant antibodies and comparing the results. The technique may be helpful to diagnose necrotizing retinitis and to ascertain viral cause in acute retinal necrosis.

Adolescent↗
PubMed1995

Calcific leiomyoma. A unique case report.

Leiomyomas are benign soft tissue tumors originating in smooth muscle. They present clinically as a soft tissue mass causing a well localized, paroxysmal pain. Treatment of choice for such lesions is total excision. Recurrence or malignant transformation of these tumors is rare. Calcific leiomyomas, as diagnosed in this study, have seldom been reported in the foot. When treating lesions involving atopic calcification, it is important to maintain a high level of understanding of the various etiologies, both metabolic and nonmetabolic, which may lead to calcium deposition in the soft tissues.

Calcinosis↗