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Biomedical subjects

A Mendivil

Publications and source records attributed to A Mendivil.

8 recordsLinked to original sources

Artificial antigen-presenting cells as a tool to exploit the immune 'synapse'.

Recent progress in molecular medicine has provided important tools to identify antigen-specific T cells. In most cases, the approach is based on oligomeric combinations of recombinant major histocompatibility complex-peptide complexes fixed to various rigid supports available for binding by the T-cell receptor. These tools have greatly increased our insight into mechanisms of immune responses mediated by CD8+ T cells. Examples of the diverse fields of application for this technology include immunization, viral infections and oral tolerance induction.

Antigen Presentation↗

Ocular blood flow velocities in patients with proliferative diabetic retinopathy after panretinal photocoagulation.

Color Doppler imaging allows for simultaneous two-dimensional anatomical imaging and Doppler measurement of blood-flow velocity. Because hemodynamic changes have been seen in diabetic patients after photocoagulation by other techniques, the author compared 25 eyes of 25 patients with proliferative diabetic retinopathy before and 6 months and 1 year after panretinal photocoagulation with a matched control group of 30 eyes of 30 healthy volunteers. The ophthalmic artery, short posterior ciliary artery, central retinal vessels, and vortex veins of all patients were examined, and the systolic, diastolic, and mean arterial velocities were measured. Panretinal photocoagulation was performed with these parameters: 800-1000 spots, 0.1 second, 500 microm argon laser. The blood velocity was significantly lower in diabetic patients than in normals in the ophthalmic artery and the central retinal artery. After treatment, blood-flow velocities were significantly lower than before photocoagulation in the ophthalmic artery, the central retinal artery and the central retinal vein. No statistically significant differences were found between 6 months and 1 year after panretinal photocoagulation. No significant correlations were found between age and blood velocities in diabetics and healthy volunteers. Eyes with proliferative diabetic retinopathy showed lower ocular perfusion velocities than normals in the ophthalmic artery and the central retinal artery. Photocoagulation resulted in a reduction in ocular blood-flow velocities in the ophthalmic artery, the central retinal artery and the central retinal vein; these values did not change significantly during 1 year of follow-up.

Adolescent↗

Influence of a dilated pupil on the visual field in glaucoma.

PURPOSE: The author studied the effects of pupillary dilation on perimetry in a group of glaucomatous patients receiving timolol therapy. PATIENTS AND METHODS: A prospective study compared the visual fields of 23 patients with primary open-angle glaucoma of varying severity (mean defect: 3.84; short-term fluctuation: 1.91; pattern standard deviation [SD]: 3.61; corrected pattern SD: 3.12) before and after instillation of phenylephrine 10% using the Octopus 1-2-3 projection perimeter (INTERZEAG AG, Schlieren, Switzerland). RESULTS: The mean defect became impaired by an average of 3.01 (SD +/- 1.52) dB after administration of phenylephrine (p < 0.001). The pattern SD and the corrected pattern SD also became impaired with dilation by 1.51 dB (p < 0.01) and 1.73 dB (p < 0.05), respectively, after dilation. These changes varied across the visual field. The outer zone of the visual field had the greatest impairment after dilation with phenylephrine. CONCLUSIONS: Pupillary dilation in patients with glaucoma produces a nonuniform decrease in threshold sensitivities that is statistically greater on outer zone of the visual field.

Accommodation, Ocular↗

Ocular blood flow velocities in patients with proliferative diabetic retinopathy after scatter photocoagulation. Two years of follow-up.

PURPOSE: Color Doppler imaging allows for simultaneous two-dimensional anatomic imaging and Doppler measurement of blood flow velocity. Because hemodynamic changes have been seen in diabetic patients after photocoagulation by other techniques, the authors compared 25 eyes with proliferative diabetic retinopathy before, 6 months after, 1 year after, and 2 years after panretinal photocoagulation with a matched control group of 30 healthy volunteers (55 eyes). METHODS: The ophthalmic artery, short posterior ciliary artery, central retinal vessels, and vortex veins of all patients were examined, and the systolic, and diastolic, and mean arterial velocities were measured. Panretinal photocoagulation was performed with these parameters: 800-1000 spots, 0.1 second, 500-microns argon laser. RESULTS: Student's t test revealed that the perfusion velocity was significantly lower in diabetic patients than in healthy controls (V systolic in the ophthalmic artery: 31.7 +/- 6.7 cm/s vs. 36.6 +/- 7.0 cm/s, respectively, P = 0.03). After treatment, blood flow velocities were significantly lower than before photocoagulation (V systolic in the ophthalmic artery: 6 months after treatment, 26.9 +/- 7.2 cm/s, P = 0.018; 1 year after photocoagulation, 25.5 +/- 7.0 cm/s, P = 0.009; and 2 years after photocoagulation, 25.7 +/- 6.8 cm/s, P = 0.01). No statistically significant differences were found between 6 months, 1 year, and 2 years after panretinal photocoagulation. No significant correlations were found between patient age and blood velocities in diabetics and healthy volunteers. CONCLUSIONS: Eyes with proliferative diabetic retinopathy showed lower ocular perfusion velocities than controls. Photocoagulation resulted in a reduction in ocular blood flow velocities; these values did not change during 2 years of follow-up.

Adult↗

Bilateral cystoid macular edema in a 21-year-old woman.

Dominant cystoid macular dystrophy (DCMD) is characterized by a prolonged course of bilateral macular cystoid change associated with leakage on fluorescein angiography, progressive loss of central vision, peripheral retinal pigmentary disturbances and subnormal electro-oculogram. The pigmentary changes and the electro-oculographic findings suggest dysfunction of the retinal pigment epithelium. We report the case of a woman affected by this dystrophy with its characteristic features.

Adult↗