Pyridoxine might not have a preventive effect on the retinyl palmitate-induced viscerocranial anomalies.

Viscerocranial anomalies are induced in the presence of various teratogens. Vitamin A-induced cleft palate formation is one of the most frequently used experimental models in these studies. However, the underlying mechanisms are not yet fully understood. Several studies have shown that exogenous vitamin A disrupts the fusion of the palatal shelves by increasing the expression of epidermal growth factor receptor (EGFR). More recently, pyridoxine (vitamin B6) has been reported to have a potentially protective effect in regard to viscerocranial malformations. Therefore, in this study, we aimed to investigate whether pyridoxine has a preventive effect on retinyl palmitate-induced viscerocranial anomalies. The frequency of gross malformations induced by retinyl palmitate, the natural form of vitamin A, has been studied in a dose dependent manner. Low doses of retinyl palmitate (100 mg/kg) exposure on embryonic day (ED) 10 caused no gross anomalies in the rat fetuses. Teratogenic effects were observed only after exposure to higher dosages (1000 mg/kg) and primarily targeted the developing eyes and palates. On the other hand, co-administration of 10mg/kg pyridoxine, at ED 9 and 10, significantly increased the frequencies of anomalies, even in the moderate dosage (500 mg/kg) group. In all cleft palates, sustained expression of EGFR in the medial edge epithelium was detected by immunohistochemistry. These results show that co-administration of pyridoxine has an inductive rather than protective effect on the formation of viscerocranial malformations after exposure to hypervitaminosis-A.

The protective effects of vitamin E on urinary bladder apoptosis and oxidative stress in streptozotocin-induced diabetic rats.

OBJECTIVES: To determine whether vitamin E has protective effects or not on streptozotocin-induced diabetic rats in diabetic urinary bladder dysfunction, with interrelationships between oxidative stress and apoptosis. METHODS: Thirty-two Wistar albino male rats were divided into 4 groups. Group A (n = 8), control; group B (n = 8), diabetic control; group C (n = 8), control + vitamin E; and group D (n = 8), diabetic + vitamin E. Vitamin E was injected 40 mg/kg every other day intraperitoneally for 2 weeks. In the diabetic groups, diabetes was induced by a single intraperitoneal injection of 65 mg/kg of streptozotocin. Apoptosis studies were performed using apoptosis detection kit and the TUNEL (TdT-mediated dUTP nick-end labeling) technique. The levels of glucose, malondialdehyde (MDA), superoxide dismutase, catalase, and glutathione peroxidase were detected in hemolysate. RESULTS: It was observed that apoptosis number in urothelial cells of the bladder in diabetic rats increased significantly compared with control and decreased after vitamin E treatment. MDA levels of the diabetic group were significantly higher than those on the control and vitamin E groups. Diabetic + vitamin E group had significantly increased MDA levels compared with control group, although these values were lower than those in the diabetic group. All enzyme activities of the vitamin E group did not differ compared with the control group. In diabetic + vitamin E group, superoxide dismutase and glutathione peroxidase activities were similar to controls. Catalase activity of the diabetic + vitamin E group decreased significantly compared with control, although it was higher than that in the diabetic group. CONCLUSIONS: Our study revealed that vitamin E decreases apoptosis and may be protective for uroepithelial cells of diabetic bladder.

Protective effects of vitamin E on central nervous system in streptozotocin-induced diabetic rats.

OBJECTIVE: To evaluate the histopathological and antioxidant effects of vitamin E (VE) treatment on brain tissue in streptozotocin (STZ)-induced diabetic rats. METHODS: Thirty two male Wistar albino rats were used. The study comprised four groups of 8 rats: Group A - untreated group, group B - diabetic group, group C - VE and group D - diabetic plus VE. In the diabetic groups, diabetes was induced by a single intraperitoneal injection of 65 mg/kg STZ. Vitamin E was given 50 mg/kg/day i.p. for three weeks. Concentrations of glucose, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were detected in the haemolysate. RESULTS: Glucose concentrations were increased in the blood of the STZ-treated rats compared with those in the diabetic groups (group B and D). The MDA concentrations in the brain from diabetic rats increased, whereas the GPx, SOD, CAT concentrations decreased. Treatment with VE returned concentrations of MDA, GPx, SOD and CAT toward control values. The MDA concentration in the diabetic group (20.65+/-2.24 nmol/mg Hb) was decreased compared with the VE treated group (15.54+/-1.32 nmol/mg Hb). There were no pathological differences between untreated and VE treated rats' brains. Neuronal ischemic damages were determined in STZ-induced diabetic rats. Ischemic neuronal alterations in group B (diabetic) had more damage than group D (diabetic + VE). CONCLUSION: The study revealed neuroprotective effects of VE on ischemic damage in diabetic central neuronal cells, caused by diabetic oxidative stress.

Anatomy of the eye from the view of Ibn Al-Haitham (965-1039). The founder of modern optics.

Ibn Al-Haitham (known as Alhazen in Latin [965 Basra, Iraq-1039, Cairo, Egypt]) was a scientist who played an important role in the middle age Islam world. He wrote many books and novels, but only 90 of them are known. His main book Kitab al-Manazir was translated into Western languages in the late twelfth century, and in the early thirteenth century. In this book, he formulated many hypotheses on optical science. The book, which is also known as Optic treasure (opticae thesaurus), affected many famous Western scientists. He became an authority until the seventeenth century in the Eastern and Western countries. Roger Bacon (1212-1294), who made radical changes in the Western optical traditions, reconfirmed Ibn Al-Haitham's findings. Ibn al-Haitham began his book Kitab al-Manazir with the anatomy and physiology of the eye. He specifically described cornea, humor aqueous, lens, and corpus vitreum. He examined the effect of light on seeing. He caused changes in the prevailing ideas of his age, and suggested that light came from objects, not from the eye. He provided information regarding the optic nerve, retina, iris, and conjunctiva. He showed the system of the eye as a dioptric, and the relations between the parts of the eye. It is understood that he mastered all knowledge on the structure of the eye in his century. The best proof of this is the eye picture that he drew.

Relation between cranial venous return and hand preference by magnetic resonance angiography.

OBJECTIVE: This study was conducted to determine whether there is a relationship between hand preference and the site of cranial venous return. Magnetic resonance angiography was used for the determination of the site of dominance of cranial venous return. METHODS: Forty-seven right-handed and 45 left-handed subjects participated in the study conducted at the Sevgi Hospital in Ankara, Turkey between 1996 and 2000. The site of cranial venous return was determined by calibration of the superior jugular bulbus and named as right (R), left (L) and right-left (R-L). Calibrations of superior jugular bulbus were analyzed by one way variance analyses. RESULTS: There were statistically significant differences when analyzing the hand preference and calibration in the subjects with a venous return from the left, than from the right and right-left. The site of venous return (R, L, R-L) and venous calibration were analyzed by student t-test and were not statistically significant. CONCLUSION: The venous return was from the left in right-handed subjects and from the right in left-handed subjects. Correlation`s of hand preference and age and sex could not be made. For both-sided venous return, ambidexterity could not be determined.

Morphometric analysis of embryonic rat trigeminal neurons treated with different neurotrophins.

In whole-mount explant cultures of the trigeminal ganglion (TG) with intact peripheral and brainstem targets, exogenous application of nerve growth factor (NGF) and neurotrophin-3 (NT-3) leads to elongation and precocious arborization of embryonic trigeminal axons, respectively. In addition, neurotrophins play a major role in survival and differentiation of distinct classes of TG neurons. In the present study, we conducted morphometric analyses of trigeminal neurons exposed to exogenous NGF or NT-3 in whole-mount explant cultures. Explants dissected from embryonic day (E) 13 and E15 rats were cultured in the presence of serum-free medium (SFM) or in SFM supplemented with NGF or NT-3 for 3 days. TG neurons were then retrogradely labeled with lipophilic tracer DiI and their soma size distributions were compared following different treatments. The mean diameters of E13 and E15 trigeminal neurons grown in the presence of NT-3 were similar to those grown in SFM. On the other hand, in cultures supplemented with NGF, the mean diameters of neurons were larger at E13, but smaller at E15. Double immunolabeling with TrkA and TrkC antibodies confirmed the presence of large-diameter TrkA-positive neurons in E13 TG, but not in E15 TG. At both ages, other large-diameter neurons expressed only TrkC. These results show that exposure to NGF leads to phenotypic changes in TrkA-expressing trigeminal neurons at early embryonic development, but selective survival of small diameter neurons at later ages.