Effects of vitamin K1 on fluoride-induced bone changes in growing rats: a histomorphometric and radiodensitometric study.

The aim of this study was to investigate the potential effects of vitamin K1 supplementation on skeletal changes related to fluoride in growing rats. Forty male Wistar rats aged 4 weeks were assigned at random into three groups: high-dose fluoride (125 ppm) group; high-dose fluoride + vitamin K1 (0.2 mg/(g day)) group; and a control group. The experimental period was 12 weeks. The L3 vertebrae and the right tibiae were removed, and specimens were analysed by histologic and histomorphometric methods. Quantitative radiodensitometry was also employed to assess the differences in bone mineral density (BMD) between the groups. In the tibia, total tissue area was higher in the study groups than the control group (P < 0.05). Cortical bone area was slightly higher in the fluoride + K1 group than the fluoride group, and marrow cavity area was lower in the fluoride + K1 group (P < 0.05). In the L3 vertebral cancellous bone, bone volume, trabecular number and trabecular thickness were higher in the study groups than the control group (P < 0.05). Trabecular separation was reduced in the study groups (P < 0.05), and was lower in the fluoride + K1 group than the fluoride group (P < 0.05). The fluoride + K1 group had a significantly higher BMD than the other groups (P < 0.05), and the fluoride group had a significantly higher BMD than the control group (P < 0.05). The present study found that fluoride administration increased bone mass in both vertebrae and tibiae in growing rats. Simultaneous administration of vitamin K1 and fluoride resulted in an additional increase in vertebral bone mass.

Iodine deficiency: an important and severe public health problem in Kayseri, Central Anatolia.

Iodine deficiency (ID) remains a significant global public health problem. The iodine status of rural areas of Kayseri Province, Central Anatolia was previously evaluated but a screening survey covering both rural and urban populations had not been conducted. The aims of this study were: a) to determine the nutritional iodine status by calculating urinary iodine excretion (UIE) of the school-children living in the districts, city centre and villages of Kayseri Province; b) to implement preventive measures. The study group was made up of 1,784 school-children (920, 51.6% females; 864, 48.4% males), aged between 7 and 12 yr. Height and weight of children were measured and urine samples were collected. The median UIE of all school-children was 25.5+/-17.2 microg/l. Iodine status of the population was gauged based on median urinary iodine values categorised as normal (> or =100 microg/l), mild (50- 99 microg/l), moderate (20-49 microg/l) and severe (<20 microg/l) ID and classified according to age, gender and body mass index (BMI). While UIE of 289 school-children (16.2%) was in normal range (> or =100 microg/l), 747 of school-children (41.9%) had UIE <20 microg/l. Although there was no significant difference in UIE of female children based on their BMI (p>0.05), in overweight and obese male children UIE was significantly higher than in normal or underweight children (p<0.001). In Kayseri, moderate and almost severe ID affects public health from intrauterine to advanced stages of life. This is due to geographical characteristics of this area causing insufficient amounts of iodine in the drinking water and traditional nutritional habits of the families. The local "Iodine Monitoring Committee" developed an action plan including information/education/ communication activities to sustain monitoring so as to increase the inclusion of iodized salt in the region.

The role of extracellular calcium in the pathophysiology of myotonic dystrophy.

Increased intracellular calcium levels in myotonic dystrophy have been repeatedly reported in many studies. In our recent investigations, the entrance of extracellular calcium ions through voltage sensitive calcium channels (VSCCS) during repetitive action potentials and late after potentials (LAPs) in tetanic responses were found. Since there is an increased amplitude of LAPs and after-discharges in muscle fibers of myotonic dystrophy, we suggest that this pathological increase in the electrical properties of the muscle could also be responsible for this elevated intracellular calcium level.