The impact of Technetium-99m dimercapto-succinic acid scintigraphy on DNA damage and oxidative stress in children

BACKGROUND

Technetium-99m-dimercapto succinic acid (Tc-99m DMSA) scintigraphy is a commonly used imaging modality in children with urological abnormalities. The radiopharmaceuticals, which have the effects of ionising radiation, are used in this method. This study aimed to investigate the impact of the Tc-99m DMSA scan on renal oxidative stress and mononuclear leukocyte (MNL) DNA damage.

METHODS

Children, who were followed up by paediatric nephrology at Bezmialem Vakif University and underwent Tc-99m DMSA scintigraphy between April 2015 and January 2016 with the indication of detection of renal scars, were included in this study. The exclusion criteria were nephrolithiasis, history of premature birth and recent urinary tract infection 3 months prior to scintigraphy or antibiotic use in the last 1 month. 3 mL heparinised blood samples were obtained just before, immediately after and 1 week after the scintigraphy. MNL DNA damage, total antioxidant status (TAS) and total oxidant status (TOS) were measured in the blood samples. The oxidative stress index (OSI) was calculated. Spot urine samples were obtained from each patient before and within 3 days after performing the scintigraphy. TAS/Creatinine (TAS/Cr), TOS/Creatinine (TOS/Cr) and N-acetyl-glucosaminidase/creatinine (NAG/Cr) levels were measured in the urine samples.

RESULTS

Twenty-seven children were evaluated. The values between TAS, TOS and OSI levels in serum samples at baseline, immediately after and 1 week after the scintigraphy (P = .105, P = .913, and P = .721, respectively) showed no statistically significant difference. The levels of TAS/Cr, TOS/Cr, NAG/Cr ratios and OSI, which were evaluated from urine samples before and within 3 days after the scintigraphy scan were also similar (P = .391, P = .543, P = .819 and P = .179, respectively). The levels of DNA damage only increased following scintigraphy scan and decreased a week later (P < .05).

CONCLUSIONS

The effect of Tc-99m DMSA scintigraphy is insufficient to create oxidative damage, but it can cause DNA damage via the direct impact of ionising radiation which can be repaired again in a short time.

Effects of long-term pre- and post-natal exposure to 2.45 GHz wireless devices on developing male rat kidney

PURPOSE

The aim of the present study was to investigate oxidative stress and apoptosis in kidney tissues of male Wistar rats that pre- and postnatally exposed to wireless electromagnetic field (EMF) with an internet frequency of 2.45 GHz for a long time.

METHODS

The study was conducted in three groups of rats which were pre-natal, post-natal. and sham exposed groups. Oxidative stress markers and histological evaluation of kidney tissues were studied.

RESULTS

Renal tissue malondialdehyde (MDA) and total oxidant (TOS) levels of pre-natal group were high and total antioxidant (TAS) and superoxide dismutase (SOD) levels were low. Spot urine NAG/creatinine ratio was significantly higher in pre- and post-natal groups (p < 0.001). Tubular injury was detected in most of the specimens in post-natal groups. Immunohistochemical analysis showed low-intensity staining with Bax in cortex, high-intensity staining with Bcl-2 in cortical and medullar areas of pre-natal group (p values, 0.000, 0.002, 0.000, respectively) when compared with sham group. Bcl2/Bax staining intensity ratios of medullar and cortical area was higher in pre-natal group than sham group (p = 0.018, p = 0.011).

CONCLUSION

Based on this study, it is thought that chronic pre- and post-natal period exposure to wireless internet frequency of EMF may cause chronic kidney damages; staying away from EMF source in especially pregnancy and early childhood period may reduce negative effects of exposure on kidney.

Protective effects of erdosteine, vitamin E, and vitamin C on renal injury induced by the ischemia-reperfusion of the hind limbs in rats

BACKGROUND/AIM

To compare the protective efficacy of erdosteine and vitamins C and E against renal injury caused by hind limb ischemia-reperfusion (I/R).

MATERIALS AND METHODS

Rats were split into 4 groups: group I as the control, group II as I/R, group III as I/R + erdosteine, and group IV as I/R + vitamins C and E. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) tissue levels were determined.

RESULTS

MDA levels were found comparable with the control group in groups II and III. However, they were considerably decreased in group IV when compared to group II (P < 0.01). Additionally, SOD, CAT, and GSH-Px activities were considerably (P < 0.05) decreased in group II. While CAT and GSH-Px activities were restored (P <0.01) by vitamin E and C treatment, SOD activity was not significantly affected. While GSH-Px activities were higher (P < 0.05) with erdosteine administration, SOD and CAT activities were unchanged.

CONCLUSION

The protective effect of vitamins C and E is higher than that of erdosteine treatment in reducing the oxidative stress after renal ischemia in this animal model.

Myeloperoxidase 463 G>A and superoxide dismutase Ala16Val gene polymorphisms in obese children

The aim of the study was to determine the role of MnSOD Ala16Val and MPO G-463A gene polymorphisms in the pathogenesis of metabolic syndrome in obese children. A total of 97 obese children with insulin resistance and, as a control group, 96 healthy children were enrolled in the study. In the obese group, AA, AV and VV genotype frequencies of the MnSOD gene and GG, GA and AA genotype frequencies of the MPO gene were not significantly different from the frequencies found in the control group (p=0.555 and 0.530, respectively). In the obese group, children who carry both VV (for MnSOD) and GG (for MPO) alleles (n= 26) had higher HOMA-IR levels (6.51 ± 3.91 vs 5.03 ± 2.12) than those of all other genotype combinations (n=71) (p=0.013). Children who have the maximum risk of developing oxidative stress with the combination of the VV (for MnSOD) and GG (for MPO) genotypes had higher HOMA-IR levels, suggesting these polymorphisms may lead to insulin resistance.

Genetic polymorphisms of paraoxonase1 192 and glutathione peroxidase1 197 enzymes in familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive disorder and is the most frequent of the periodic febrile inflammatory syndromes. The pathogenesis of the disease is not completely understood, even though the FMF gene has been identified. Oxidative stress and inflammation may play a role in the pathogenesis of FMF. We investigated gene polymorphisms of the antioxidative enzymes, glutathione peroxidase (GPX) and paraoxonase (PON) in FMF patients, and possible associations with FMF pathogenesis. Sixty FMF patients during an attack-free period and 51 healthy children as the control group were included in our study. PON1 Q/R192 and GPX1 Pro197Leu gene polymorphisms were assayed. Blood urea nitrogen, creatinine and serum lipid profile were also measured. PON1 Q/R192 genotype distribution was 52% QQ, 46% QR and 2% RR in the FMF group and 45% QQ, 45% QR and 10% RR in the control group (P>0.05). GPX1 Pro197Leu genotype distribution was 28% PP, 57% PL, 15% LL in the FMF group and 18% PP, 53% PL, 29% LL in the control group (P>0.05). Blood urea nitrogen, serum creatinine, lipid levels, and the distribution of PON1 Q/R192 and GPX1 Pro197Leu genotypes were similar in the two groups. We conclude that the PON1 Q/R192 and GPX1 Pro197Leu gene polymorphisms are not important risk factors in the development of FMF. However, larger studies are warranted to validate these conclusions.

Hemolytic uremic syndrome outbreak in Turkey in 2011

The aim of this retrospective multicenter study was to define the epidemiological and clinical features and prognostic factors of the first diarrhea-related hemolytic uremic syndrome (D+HUS) outbreak in Turkey in 2011. All pediatric nephrology centers in Turkey were asked about D+HUS patients via e-mail. Seventy D+HUS patients (median age: 5.7 years) participated. The seasonal peak was around the 7th, 8th and 9th months with 44 cases, centered in the east Marmara region. No causative agent could be identified. The rate of neurological complications and mortality was 21.4% and 4.2%, respectively. Eculizumab was used in four cases. Two of them had severe neurological complications despite plasma exchange. Elevated polymorphonuclear leukocyte count during hospital admission was the predictor of both severe disease and poor outcome. Duration of prodrome was the predictor of poor outcome (p<0.05). In conclusion, the median age of the affected children was greater than in the previous reports, while clinical features and outcome were similar.

Vitamin d deficiency and insufficiency in obese children and adolescents and its relationship with insulin resistance

Objectives. We aimed to determine the relationship between insulin resistance and serum 25-hydroxyvitamin D (25-OHD) levels in obese children and their nonobese peers. Materials and Methods. Included in the study group were 188 obese children (aged 9-15 years), and 68 age- and gender-matched healthy children of normal weight as control group. Anthropomorphic data were collected on patients and fasting serum glucose, insulin, serum lipids, alanine aminotransaminase (ALT) and 25-OHD were measured. The homeostatic model assessment of insulin resistance (HOMA-IR) was calculated in both groups. Results. The levels of 25-OHD in the obese group were significantly lower than those of the nonobese (P = 0.002). HOMA-IR, triglycerides, low-density lipoprotein, and ALT levels in the obese group were significantly higher than values of control group (P < 0.001 and P = 0.002, resp.). In the obese group, vitamin D deficiency, insufficiency, and sufficiency (25-OHD < 10 ng/dl, < 20, >10 ng/dl; > 20 ng/dl, resp.) were not correlated with HOMA-IR (r : -0.008, P = 0.935). HOMA-IR was negatively correlated with BMI, BMI SDS, and BMI%, and triglycerides, low-density lipoprotein, and ALT levels (P < 0.001). Conclusion. The insulin resistance of the obese subjects who were vitamin D deficient and insufficient did not statistically differ from those with vitamin D sufficiency. Low 25-hydroxyvitamin D levels were not related with higher insulin resistance in obese children and adolescents. In obese subjects, insulin resistance was affected more from BMI, BMI SDS, and BMI% than from 25-hydroxyvitamin D levels.