Dielectric properties of red blood cells pretreated by different types of vitamins

The effect of different vitamins [niacin [B5], pyridoxine [B6], thiamin [B1] and ascorbic acid [c]] on human red blood cells [RBC] in vitro has been studied. The dielectric parameters, electric conductivity, the relaxation frequency and dipole moment were measured over a frequency range from 50 Hz to 100 kHz .These parameters were used to follow up the variations occur in the red blood cells after one hour from incubation with such vitamins. The variations in all parameters are compared with the control specimen [without adding vitamins]. The dielectric parameters [epsilon, epsilon], conductivity [sigma] and dipole moment [D] were found to be decreased in comparison with the control one, while the relaxation frequency increases. The obtained results showed that the used vitamins may cause variations in structure and function of red blood cells, and consequently the risks of using large amounts of these vitamins for long time

Hydrocortisone effects on composition of rat bone

Hydrocortisone is sometimes used as a necessary treatment for many diseases. But unfortunately, it usually causes osteoporosis when used for long periods of administration even with normal doses. It produces variations in calcium and phosphate contents in bones. The aim of the present work is to study the effects of long period hydrocortisone treatment on the bone composition of rat hind-leg. Three techniques were used in this study: X-ray imaging to analyze the bone density, molecular spectrophotometer for determining bone composition and histological study to clear the bone structure. The obtained data showed variations in calcium and phosphate contents during the hydrocortisone treatment periods which reached maximum changes after three weeks of treatment. The obtained results by X-ray images indicated changes in the bone density which were supported and found in good agreement with that obtained by both spectrophotometric analysis and structural changes

Structure changes in chicken retina caused by argon laser irradiation

Infrared spectroscopic study has been performed on chicken retina before and after argon laser irradiation. The infrared [IR] spectra obtained from intact retina are in agreement with the polarized [IR] studies on rhodopsin, which indicate that it has an alpha - helical structure with fixed orientation with the membrane normal. Retinae exposed to argon laser light of constant intensity [1mW/cm] and different durations [0.12 and 0.25 sec] at constant temperatures [10, 20 and 30 degree] show no detectable spectral changes, indicating that there is no change in the main helical structure of protein. However, distinct changes occur in the orientation angle of rhodopsin. It was found that the sensitivity of chicken retina for the recovery of the rhodopsin reorientation is more pronounced after laser irradiation of duration 0.12 sec. than that of 0.25 sec. Also the decrease in the chicken temperature by 10 degree could compensate the heating effect due to the increase in laser duration