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Biomedical subjects

S Bafna

Publications and source records attributed to S Bafna.

9 recordsLinked to original sources
PubMed1998

Axial, instantaneous, and refractive formulas in computerized videokeratography of normal corneas.

PURPOSE: To compare the values for corneal power determined by the axial, instantaneous and refractive formulas when imaging normal human corneas using computerized videokeratography. SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. METHODS: This prospective clinical trial involved 60 corneas of 30 normal volunteers. Computerized videokeratography was performed to determine corneal power at the center and the 1, 3, 5, and 7 mm zones using the 3 formulas. RESULTS: Mean central corneal power was 42.86 diopters (D) with each of the formulas. The mean corneal powers for the axial, instantaneous, and refractive formulas were 43.09, 43.21, and 42.98 D at the 1 mm zone; 43.10, 42.92, and 43.46 D at the 3 mm zone; 42.75, 41.63, and 44.02 at the 5 mm zone; 42.21, 40.30, and 44.79 D at the 7 mm zone, respectively. The differences among powers for the 3 formulas at the 3, 5, and 7 mm zones were statistically significant (P < .01). CONCLUSION: In normal corneas, clinically significant differences exist in the corneal power values calculated by the axial, instantaneous, and refractive formulas.

Adolescent↗
PubMed1997

Presumed tuberculosis presenting as a cavernous sinus syndrome.

Cavernous sinus involvement of tuberculosis is rare. We present a 65-year-old woman with extrapulmonary tuberculosis who presented with a cavernous sinus syndrome clinically. A cervical lymph node biopsy revealed non-caseating granulomas but cultures were eventually positive for M. tuberculosis.

Aged↗
PubMed1990

Effects of electric fields on cytoskeleton of corneal stromal fibroblasts.

Low-level, steady electric fields (6-10 volts/cm) stimulated cultured corneal stromal fibroblasts to undergo directional orientation and translocation. The orientative movements (galvanotropism) consisted of somatic elongation of the cells into spindle shapes along an imaginary axis perpendicular to the field; the cathodal edge of the cell underwent retraction, while the anodal edge and the longitudinal ends developed ruffled membranes and lamellipodia. The translocational movements (galvanotaxis) consisted of directed migration of the cells towards the anode. While most actin-containing stress fibers became aligned along the long axes of the elongated fibroblasts (with distal ends of the stress fibers terminating at the longitudinal extremes of the cells), some were aligned towards the anodal direction (with distal terminations inside ruffled membranes and lamellipodia on the leading anodal edge of cells). The distal ends of stress fibers were associated with discrete foci of vinculin, ie, focal indicators of cell-to-substrate adhesion; these foci were abundant at the longitudinal ends and at the anodal edge of the elongated cells. The observed cytoskeletal changes are consistent with an active, rather than passive, directed migration of stromal fibroblasts in response to constant electric fields.

Actins↗
PubMed1990

Movements of cultured corneal epithelial cells and stromal fibroblasts in electric fields.

The effects of an externally applied direct-current electric field on the movement of cultured rabbit corneal epithelial cells and stromal fibroblasts were studied. After a latency of approximately 20 minutes in an electric field, both epithelial cells and stromal fibroblasts became spindle shaped and underwent galvanotropism by aligning their long axes perpendicular to the applied electric field. The electric field stimulus thresholds for galvanotropic movements in epithelial cells and stromal fibroblasts were 4V/cm and 6 V/cm, respectively. After an additional latency of 30 minutes, both cell types manifested galvanotaxic movements: epithelial cells commenced migration in the cathodal (downfield) direction and stromal fibroblasts in the anodal (upfield) direction. For both types of cells, ruffled membranes and lamellipodia were abundant at the leading edges of migrating cells and cell processes underwent retraction at the trailing edges. At field strengths of above 10 V/cm, evidence of cellular damage (manifested by cellular rounding and detachment), attributable to the electric field treatment, was observed after 4 hours. These preliminary results suggest that galvanotaxic responses could be exploited clinically in the enhancement of corneal wound healing.

Animals↗