Effects of triamcinolone acetonide on human trabecular meshwork cells in vitro.

Aim: To study the effects of triamcinolone acetonide (TA) on cultured human trabecular meshwork (HTM) cells. Materials and Methods: HTM cells were cultured and treated with 125, 250, 500 and 1000 μg/mL concentration of TA for 24 h. The cells were treated with both crystalline TA (TA‑C) (commercial preparation) and solubilized TA (TA‑S). Cell viability was measured by a trypan blue dye exclusion test. The activity of caspse‑3/7 was measured by a fluorescence caspase kit and DNA laddering was evaluated by electrophoresis on 3% agarose gel. Levels of lactate dehydrogenase (LDH) were assessed with LDH cytotoxicity assay kit‑II. Results: Mean cell viabilities of HTM cells after 24 h exposure to TA‑C 125, 250, 500, and 1000 μg/mL were 75.4 ±2.45% (P < 0.0001), 49.43 ± 1.85% (P < 0.0001), 17.07 ± 2.39% (P < 0.0001), and 3.7 ± 0.9% (P < 0.0001), respectively, compared with the untreated HTM cells 92.49 ± 1.21%. The mean cell viabilities with 125, 250, 500, and 1000 μg/mL of TA‑S were 94.47 ± 1.60% (P > 0.05), 90.13 ± 0.40% (P < 0.01), 85.57 ± 0.47% (P < 0.001), and 71.67 ± 3.30% (P < 0.0001), respectively, compared to DMSO‑equivalent cultures. Untreated HTM control had a cell viability of 96.57 ± 1.98%. DMSO‑treated controls of 125, 250, 500, and 1000 μg/mL had a cell viability of 94.73 ± 0.57%, 96.97 ± 1.08%, 93.97 ± 1.85%, and 97.27 ± 1.15%, respectively. There was no increase of caspase‑3/7 activity in cultures treated with either TA‑C or TA‑S. DNA laddering showed no bands in the TA‑C or TA‑S treated cultures. There were significantly higher LDH release rates at all concentrations of TA‑C compared to TA‑S. Conclusions: Results show that the effect of TA‑C and TA‑S on HTM cells is due to cell death by necrosis at all concentrations except 125 μg/mL of TA‑S. Elevated levels of LDH confirmed necrotic cell death. Our study also infers the relative safety of TA‑S over TA‑C.

Sensory nerve conduction velocity is greater in left handed persons.

Dependence of nerve conduction velocity on factors like age, sex and temperature is well known. Effect of handedness on nerve conduction velocity has not been studied adequately. In this study correlation between handedness and motor as well as sensory conduction velocity of right as well as left median nerve was studied in 84 medical students in the age group between 17-21 years out of which 72 were right handed and 12 were left handed. In addition auditory and visual reaction times were also studied. Sensory conduction velocity in both right and left median nerve was significantly higher in left handers as compared with right handers whereas, the motor conduction velocity in right handers and left handers was not different. The auditory and visual reaction times were also not different in these groups. Because of greater sensory conduction velocity in left handers there is a requirement of different set of normal reference values for left handers in clinical diagnosis.

Lead acetate induced contraction in rat tracheal smooth muscle is independent of epithelium.

Airways are the primary target of lead exposure from atmospheric pollution, its effect on airway smooth muscle and their responsiveness to bronchoactive agents is not clearly understood. In the present investigation the effect of lead on the isolated airway smooth muscle activity was studied in organ bath set-up. Further the involvement of airway epithelium was examined and the responsiveness of airway smooth muscle to adenosine, acetylcholine (bronchoconstrictors) and isoproterenol (bronchodilator) was also investigated. Lead in concentration of 10(-12) M to 10(-4) M produced concentration-dependant contractile response in rat tracheal rings. Acetylcholine and adenosine induced concentration-dependent contractile response was slightly inhibited after lead exposure. The relaxant response to isoproterenol was also inhibited in lead exposed tissues. Epithelium removal did not significantly change the contractile response to lead suggesting that the lead induced contraction of airway smooth muscle is epithelium independent.