Investigation of relationship between colour discrimination ability and stereoscopic acuity using Farnsworth Munsell 100 hue test and stereo tests.

OBJECTIVE: To evaluate the effect of colour discrimination ability on the stereoscopic acuity by comparing individuals having congenital colour vision deficiency (CCVD) with healthy individuals. DESIGN: A comparative study. PARTICIPANTS: The study included 53 binocular males, of whom 26 (mean age, 36.04 ± 9.30 years) were in the healthy group and 27 (mean age, 33.04 ± 9.81 years) were in the CCVD group. METHODS: The following tests were used: the Ishihara pseudo-isochromatic plate test for detecting CCVD, the Farnsworth Munsell 100 (FM100) hue test for colour discrimination ability, the TNO and Titmus stereo tests for stereoscopic acuity. RESULTS: In the CCVD group, 20 males were deutan and 7 males were protan. According to the FM100 hue test, total error score (TES), blue/yellow (b/y) local error score (LES), and red/green LES were significantly lower in the healthy group (30.23 ± 18.78, 15.15 ± 10.38, and 13.88 ± 11.93, respectively) than in the CCVD group (133.59 ± 67.45, 41.15 ± 22.03, and 89.15 ± 52.16, respectively) (p < 0.01 for each). The stereo test scores revealed significantly higher stereoscopic acuity in the healthy group (43.85 ± 33.92 arcsec for the TNO test and 40.00 ± 0.00 arcsec for the Titmus test) than in the CCVD group (93.33 ± 90.51 arcsec for TNO stereo test and 52.96 ± 24.62 arcsec for the Titmus test) (p < 0.05 for each). The TNO test score was significantly and positively correlated with the TES (r = 0.390, p = 0.049) and b/y LES (r = 0.490, p = 0.011) in the healthy group. CONCLUSIONS: Colour discrimination ability affected stereoscopic acuity. Moreover, stereoscopic acuity increased with increasing colour discrimination ability, which could be originated from the b/y colour region.

Polyphasic Temporal Behavior of Finger-Tapping Performance: A Measure of Motor Skills and Fatigue.

Successive voluntary motor movement involves a number of physiological mechanisms and may reflect motor skill development and neuromuscular fatigue. In this study, the temporal behavior of finger tapping was investigated in relation to motor skills and fatigue by using a long-term computer-based test. The finger-tapping performances of 29 healthy male volunteers were analyzed using linear and nonlinear regression models established for inter-tapping interval. The results suggest that finger-tapping performance exhibits a polyphasic nature, and has several characteristic time points, which may be directly related to muscle dynamics and energy consumption. In conclusion, we believe that future studies evaluating the polyphasic nature of the maximal voluntary movement will lead to the definition of objective scales that can be used in the follow up of some neuromuscular diseases, as well as, the determination of motor skills, individual ability, and peripheral fatigue through the use of a low cost, easy-to-use computer-based finger-tapping test.

Anticonvulsant efficacy of melatonin in an experimental model of hyperthermic febrile seizures.

INTRODUCTION: The anticonvulsant effects of melatonin (MT) have been demonstrated in several different experimental seizure models. Thus, the present study aimed to determine the anticonvulsant efficacy of MT, the optimum time for its administration prior to the induction of a seizure, and its effective dose in a rat model of hyperthermic febrile seizures (FSs). METHODS: The present study included 72 male Sprague-Dawley rat pups divided into eight groups. The seizures were induced by keeping the rats in 45 °C water and the experiments were performed in two steps. In the first step, the control group was given a vehicle injection and the study groups were given a MT injection (150 mg/kg, intraperitoneal [i.p.]) at either 5, 10, or 15 min prior to the induction of the seizure to determine the anticonvulsant effects of MT and its optimum time of administration. In the second step, a vehicle injection and three different doses of MT (80, 100, and 150 mg/kg, i.p.) were administered 15 min prior to the induction of the seizure to determine the dose at which anticonvulsant effects could be achieved. The anticonvulsant effects were assessed based on the latency of the FSs. RESULTS: In the first-step experiments, the FS latency of the control group was 143.4 ± 15.3s and the latencies of the groups given melatonin at either 5, 10, or 15 min prior to the seizure were 174.2 ± 28.9, 177.4 ± 21.0, and 193.7 ± 17.6s, respectively. Compared with the control group, the latencies for each of the study groups were significantly longer (p<0.001), with the longest latency observed in the group given melatonin 15 min before the seizure. In the second-step experiments, the FS latencies of the groups that were given 80, 100, and 150 mg/kg of MT 15 min before the seizure were 238.7 ± 4.0, 240.0 ± 0.0, and 193.7 ± 17.6s, respectively. These latencies were significantly longer than those of the control group (172.3 ± 30.3s, p<0.001). CONCLUSION: The present study demonstrated that MT exerts anticonvulsant effects in a rat model of hyperthermic FSs and achieved its optimum efficacy at a dose of 80 mg/kg when administered 15 min prior to the induction of a seizure.

Relation of eye dominancy with color vision discrimination performance ability in normal subjects.

AIM: To evaluate the performance of dominant eye (DE) for color vision discrimination ability among the medical students with normal color vision. METHODS: Total of 50 students studying at Baskent University Faculty of Medicine, including 31 males (62%) and 19 females (38%), with visual acuity of 20/20 and without congenital color vision deficiency (CCVD) evaluated by Ishihara pseudoisochromatic plate test (IPPT) were recruited for this prospective comparative study upon their voluntary participation. DE was determined by the Gündogan Method. The color discrimination ability was examined with the Farnsworth-Munsell 100 hue (FM100) test. Test was applied by two days interval to all subjects for the three times while two eyes (TE), right eye (RE) and left eye (LE) were seeing for detecting red-green (r/g), blue-yellow (b/y) local color spectral regions error scores. The error scores were evaluated for both in DE and non-dominant (NDE). P values below 0.05 were considered to be statistically significant. RESULTS: The students aged 21.18±2.52 years (mean±SD). Without sex difference the RE and the LE dominancy were found 22 (44%) and 28 (56%) respectively and FM 100 test total error scores of DE in both r/g-b/y regions were found without gender difference 24.12±14.70, 34.68±18.95, respectively. For the NDE in both, r/g-b/y regions error scores without gender difference were 32.20±19.21, 36.24±17.56, respectively. The difference of total error scores between the DE and NDE was found as 58.80±29.92, 68.44±31.46. The statistical differences among the DE and the NDE in r/g local region and total error scores were found significant in both genders (P<0.05, P<0.001). CONCLUSION: The color vision discrimination performance ability was found prominent for DE. This superiority was attributed to higher sensitivity of the r/g local color spectral region. We conclude that DE has priority in r/g color spectral region, probably including inhibition of NDE.

Projected color slides as a method for mass screening test for color vision deficiency (a preliminary study).

This article compared the efficiency of the mass screening test with projected color slides in detecting color-blindness with the authentic classic method of Ishihara. The study was conducted in a randomly selected lecture room with 104 students aged between 19-25 years (median 21). Using Ishihara projected slides, performed mass screening test. Re-testing was done individually with printed Ishihara plates. Six male and one female with color-blindness were detected. The frequency of color-blindness was 13.6% among males, with a total incidence of 6.7%. The results of two testing methods were compared statistically. Sensitivities and specificities of both tests were 100%. Using projected slides of Ishihara plates instead of the authentic method is an effective and timesaving method for detecting color-blindness. This method can be suggested as a mass-screening test and might be beneficial in detecting color-blindness in large populations such as students, soldiers, and so on.

Hyperbaric oxygenation and antioxidant vitamin combination reduces ischemia-reperfusion injury in a rat epigastric island skin-flap model.

Reperfusion injury, caused by free oxygen radicals, is a chain of events that occurs in tissues exposed to a constant period of ischemia. The antioxidant vitamins E and C (VEC) and hyperbaric oxygenation (HBO) have beneficial effects in treating ischemic tissues following skin flap operations. In our study, we aimed to compare the effects of VEC and/or HBO in ischemia-reperfusion injury induced by free oxygen radicals in an experimental rat epigastric island skin-flap model. Eight hours of ischemia was provided by clamping the inferior epigastric pedicle following the flap elevation. The flap survey was determined to be 28.6% in controls, 59.2% in HBO group, 66.3% in VEC + HBO group, and 82% in VEC group (p < 0.05). We conclude that although HBO and/or VEC increased the flap viability significantly by reducing ischemia-reperfusion injury, the most promising results were obtained in the antioxidant vitamins group.