Comparison of 6-mm Versus 8-mm-Tip Cryoablation Catheter for the Treatment of Atrioventricular Nodal Reentrant Tachycardia in Children: A Prospective Study.

Due to its safety profile, cryoablation (Cryo) for atrioventricular nodal reentrant tachycardia (AVNRT) is more commonly preferred over radiofrequency (RF) ablation in children in recent years. Recent studies demonstrated high long-term success rates comparable to radiofrequency ablation. The aim of this prospective study was to compare the efficacy and safety of an 8-mm-tip versus 6-mm-tip Cryo catheter in the treatment of AVNRT in children. A total of 125 consecutive patients over 10 years of age with AVNRT were included. EnSite system (St. JudeMedical, St Paul, MN, USA) was used to reduce or eliminate fluoroscopy. The acute procedural success was 100% in both groups. The prodecure duration for the 8-mm-tip group was shorter (151.6 ± 63.2 vs. 126.6 ± 36.7 min, p < 0.01, respectively). Fluoroscopy was used in only 7 patients. The mean follow-up duration was 14.6 ± 8.4 months (median 13.5 months, min. 3 months and max. 27 months). The recurrence rate for AVNRT was also comparable between the two groups (6-mm tip: 9.6 vs. 8-mm tip: 8%). Cryo of AVNRT is a safe and effective procedure with comparable acute and mid-term follow-up success rates using 6-mm and 8-mm-tip catheters in children. In addition, procedure duration is shorter with an 8-mm-tip Cryo catheter.

Screening of novel chemical compounds as possible inhibitors of carbonic anhydrase and photosynthetic activity of photosystem II.

Thirty novel chemical compounds were designed and synthesized expecting that they would be possible inhibitors. From this number eleven were organic bases, twenty-four were their organic derivatives and fourteen were metal complexes. Screening of these chemicals by their action on photosynthetic electron transfer (PET) and carbonic anhydrase (CA) activity (CAA) of photosystem II (PSII), α-CA, as well as ß-CA was done. Several groups were revealed among them. Some of them are capable to suppress either one, two, three, or even all of the measured activities. As example, one of the Cu(II)-phenyl sulfonylhydrazone complexes (compound 25) suppresses CAA of α-CA by 88%, CAA of ß-CA by 100% inhibition; CAA of PSII by 100% and the PSII photosynthetic activity by 66.2%. The Schiff base compounds (12, 15) and Cu(II)-phenyl sulfonylhydrazone complexes (25, 26) inhibited the CAA and PET of PSII significantly. The obtained data indicate that the PSII donor side is a target of the inhibitory action of these agents. Some physico- or electrochemical properties such as diffusion coefficient, number of transferred electrons, peak potential and heterogeneous standard rate constants of the compounds were determined in nonaqueous media. pKa values were also determined in nonaqueous and aqueous media. Availability in the studied group of novel chemical agents possessing different inhibitory activity allow in future to isolate the "active part" in the structure of the inhibitors responsible for different inhibitory mechanisms, as well as to determine the influence of side substituters on its inhibitory efficiency.

Prevalence of vitamin D deficiency rickets in the eastern part of Turkey.

Turkey, especially its eastern part, has been accepted as endemic for vitamin D deficiency rickets (VDDR). In a study performed by our team in the region in 1998, the incidence of VDDR was 6.09% in children aged between 0-3 years. In 2005, the Ministry of Health initiated a free vitamin D supplementation campaign nationwide for every infant to eradicate VDDR. In this study, we aimed to investigate the prevalence of VDDR in children aged between 0-3 years in order to evaluate the effectiveness of this campaign. Between March 2007 and February 2008, 39,133 children aged between 0-3 years who were brought to different pediatric outpatient clinics in Erzurum, Turkey, were examined for VDDR. VDDR diagnosis was made by radiological and biochemical findings in the cases who were initially suspected of having clinical VDDR. During a one-year period, 39 (0.099%) of the 39,133 patients were diagnosed with VDDR. None of the cases with rickets was taking vitamin D supplementation. The most frequent physical findings were rachitic rosary, enlargement of the wrists, and craniotabes. The laboratory findings of the cases were compatible with VDDR; serum calcium (Ca) 7.5 +/- 1.9 mg/dL, PO4 4.4 +/- 1.3 mg/dL, alkaline phosphatase (ALP) 1,341 +/- 823, 25-hydroxyvitamin D (25 (OH) D) 5.8 +/- 2.9 ng/mL, intact parathyroid hormone (iPTH) 240 +/- 106 pg/mL. It was concluded that, although VDDR has been a continuing childhood health problem, a nationwide free vitamin D supplementation campaign initiated by the government appeared to be effective in eliminating VDDR.