T4 plus T3 treatment in children with hypothyroidism and inappropriately elevated thyroid-stimulating hormone despite euthyroidism on T4 treatment

AIMS

To evaluate the effect of addition of T3 to L-T4 treatment in children with congenital hypothyroidism (CH) who have inappropriately elevated thyroid-stimulating hormone (TSH) levels despite high normal serum T4 levels on L-T4 treatment.

METHODS

Ten children (age 7.1 +/- 2 years) with CH whose TSH levels were persistently high despite euthyroidism and can only be normalized with hyperthyroidism were included. L-T4 treatment was switched to T3+L-T4 combination (Bitiron(R) tablet 50 mug L-T4 + 12.5 mug triiodothyronine). The patients received 50% of their usual L-T4 dose as L-T4 and the remaining half as T3 in a 4:1 ratio. The dose of T3+L-T4 was titrated to achieve normal TSH levels. Thyroid hormones and biochemical markers were followed for 1 year.

RESULTS

Euthyrotropinemia was achieved at the 7th month (mean) of combination (T3+L-T4) treatment. Serum T4 and fT4 were lower and T3 was higher during combination compared to L-T4 treatment. LDL-cholesterol decreased and ALP increased in the euthyrotropinemic state. Vital signs were similar at hyperthyrotropinemia and euthyrotropinemia.

CONCLUSION

T3+L-T4 treatment provides euthyrotropinemia without causing hyperthyroidism in children with CH and inappropriate hyperthyrotropinemia. Our data strongly suggest that decreased negative feedback due to lower T3 levels at the pituitary level is the main reason for persistent hyperthyrotropinemia.

Reactive oxygen species and chemokines: Are they elevated in the esophageal mucosa of children with gastroesophageal reflux disease?

AIM: To determine the role of inflammatory cytokines and reactive oxygen species (ROS) in childhood reflux esophagitis.

METHODS: A total of 59 subjects who had complaints suggesting GERD underwent esophagogastroduodenoscopy. Endoscopic and histopathologic diagnosis of reflux esophagitis was established by Savary-Miller and Vandenplas grading systems, respectively. Esophageal biopsy specimens were taken from the esophagus 20% proximal above the esophagogastric junction for conventional histopathological examination and the measurements of ROS and cytokine levels. ROS were measured by chemiluminescence, whereas IL-8 and MCP-1 levels were determined with quantitative immunometric ELISA on esophageal tissue. Esophageal tissue ROS, IL-8 and MCP-1 levels were compared among groups with and without endoscopic/histo-pathologic esophagitis.

RESULTS: Of 59 patients 28 (47.5%) had normal esophagus whereas 31 (52.5%) had endoscopic esophagitis. In histopathological evaluation, almost 73% of the cases had mild and 6.8% had moderate degree of esophagitis. When ROS and chemokine levels were compared among groups with and without endoscopic esophagitis, statistical difference could not be found between patients with and without esophagitis. Although the levels of ROS, IL-8 and MCP-1 were found to be higher in the group with histopathological reflux esophagitis, this difference was not statistically significant.

CONCLUSION: These results suggest that the grade of esophagitis is usually mild or moderate during childhood and factors apart from ROS, IL-8 and MCP-1 may be involved in the pathogenesis of reflux esophagitis in children.

Role of ursodeoxycholic acid in prevention of methotrexate-induced liver toxicity

AIM

Methotrexate (MTX)-induced hepatotoxicity restricts the clinical use of this immunosuppressive drug. In this study, our aim was to research the role of oxidative stress in the hepatic toxicity of MTX and the protective effect of ursodeoxycholic acid (UDCA) in this setting.

METHODS

Wistar type rats (n = 32) were divided into four groups; group-1 as the MTX + UDCA, group-2 as the MTX, group-3 as the UDCA, group-4 as the saline-receiving groups. The MTX + UDCA and MTX groups of rats received 50 mg/kg of UDCA administered orally; whilst physiological saline was administered orally to the MTX and saline groups and continued for the next 6 days. On the second day of the study, the MTX + UDCA and MTX groups had a single intraperitoneal dose of MTX of 20 mg/kg. The UDCA and saline groups also received similar volumes of physiological saline intraperitoneally. On the sixth day, serum samples were collected and analyzed for ALT, alkaline phosphatase (ALP) and gamma glutamyl transpeptidase (GGT) and homogenated liver tissues were examined for reactive oxygen metabolites (ROM); luminol, lucigenin, lipid peroxygenation product malondialdehyde (MDA) and glutathione (GSH) levels.

RESULTS

In the MTX group, serum ALT, ALP, GGT and tissue ROM levels were higher and GSH level was lower. On the histopathological examination, hepatocellular necrosis was clearly more evident in the MTX group than the MTX + UDCA group.

CONCLUSIONS

UDCA treatment protects against MTX-induced liver toxicity. Histopathologically hepatocyte necrosis can be prevented by UDCA treatment, indicating clearly the hepatoprotective effect of this agent on MTX-induced liver injury.

Internet use among high school students in Ankara, Turkey

OBJECTIVE

Internet use has grown considerably in recent years throughout the world, particularly among young people. This study aimed at assessing Internet use among high school students.

METHODS

This is a cross-sectional epidemiological study involving 246 students in 7 classes representing first, second, and third year students (754 persons) at a high school in Ankara, Turkey during March 2001. An Internet use questionnaire comprising 34 questions was used.

RESULTS

It was found that 86.5% of the students used the Internet at home. The mean daily Internet use was 2.5 hours during vacation, and less while school was in session. Although 86.5% of students with computers at home had Internet connections, approximately half of the students reported that they had frequently gone to Internet cafe's.

CONCLUSION

Significant differences between boys and girls were found in terms of hours spent on the Internet and purpose of use, and changes over time in hours spent. "Daily" and "weekly" Internet use is more frequent among boys than girls. Boys visit cyber-sex sites more than girls. Those whose weekly Internet use was 4 hours or more were found to have been using the Internet for 36 months or more; they had irregular eating habits, and their relatives complained more frequently on the amount of time they spent on the Internet.