3-Nitrobenzanthrone (3-NBA) has been isolated from diesel exhaust and airborne particles and identified as a potent direct-acting mutagen in vitro and genotoxic agent in vivo. In order to evaluate the in vivo toxicity and carcinogenicity of 3-NBA in a situation corresponding to inhalation, a combined short-term and lifetime study with intratracheal (i.t.) instillation in female F344 rats was performed. DNA adduct formation, as a marker for the primary effect and analyzed by 32P-HPLC after single instillation, showed a few major DNA adducts and a rapid increase with a peak after 2 days, followed by a decline. No DNA adducts above the background level were observed after 16 days. The highest DNA adduct formation was observed in lung [approximately 250 DNA adducts/10(8) normal nucleotides (NN)] closely followed by kidney (approximately 200 DNA adducts/10(8) NN), whereas liver contained only 12% (approximately 30 DNA adducts/10(8) NN) of the levels of DNA adducts found in lung. In the tumor study, squamous cell carcinomas were found after 7-9 months in the high-dose group (total dose of 2.5 mg 3-NBA) and after 10-12 months in the low-dose group (total dose of 1.5 mg 3-NBA). The fraction of squamous cell carcinoma out of the total amount of tumors observed at the end of experiment at 18 months, corresponded to 3/16 and 11/16 in the low- and high-dose group, respectively. A single case of adenocarcinoma was also observed in each group. In the control group, no tumors were observed during the entire study of 18 months. In addition, a few cases of squamous metaplasia were also observed in the lung in both dose groups but not in the controls. In conclusion, 3-NBA forms DNA adducts in the lung immediately after i.t. administration but almost all DNA adducts were eliminated after 16 days. Tumor formation in two dose groups was observed in a dose-dependent manner with squamous cell carcinomas as the predominant tumor type at high exposure.

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We evaluated the prevalence of white coat (WC) effect in pediatric age patients and that of white coat hypertension (WCH) in hypertensive pediatric patients. Two hundred and six patients (136 normotensive and 70 hypertensive patients, 107 boys and 99 girls, aged 6-25 years, mean 13.4, SD 4.7) were studied. Hypertension was diagnosed when systolic and/or diastolic blood pressure (BP) measurements with auscultatory technique were >or= the 95th percentile for sex and age. WC effect was defined as office BP minus daytime mean ambulatory BP (ABP). WCH was diagnosed in the hypertensive patients when daytime ABP values were< the 95th percentile for sex and height of reference values. There was a positive correlation between office BP and WC effect ( P<0.05). A WC effect of >or= 10 mmHg was observed more frequently in hypertensive patients (50%) than in normotensive patients (25%). Among 70 hypertensive patients, 33 (47%) had WCH. There was no significant difference in the prevalence of WCH in relation to age, gender, or the presence or absence of causes of hypertension. In conclusion, WC effect is frequently seen in pediatric patients, and is more common in subjects with higher office BP.

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Objective Sclerosing encapsulating peritonitis (SEP) is a clinical syndrome with a high mortality rate and is a serious complication of peritoneal dialysis (PD). Peritoneal sclerosis (PS) is a histological diagnosis. PS is usually observed in the peritoneal specimens of patients with SEP. Avoiding SEP is considered to be extremely important for pediatric patients who may require long-term PD. In this study, the characteristics of patients with PS were investigated to determine when to perform peritoneal biopsies and how long PD can be performed safely. Design A retrospective single-center study. Setting Tokyo Metropolitan Kiyose Children's Hospital. Patients A total of 109 children younger than 16 years have received chronic PD in our unit since 1981. Among these children, 16 patients had been on PD for more than 5 years (mean 7.4 ± 2.5 years) from May 1992 to March 1999. Peritoneal biopsies were performed in 14 of the 16 patients, who were divided into two groups based on the histological diagnoses: a PS and a peritoneal fibrosis (PF) group. Results The 14 patients were on PD for a mean of 7.8 ± 2.5 years. There were 8 patients with PS and 6 patients with PF. SEP was observed in 2 patients in the PS group. The risk of PS increased with the duration of PD: 57% (8/14) > 5 years, 80% (4/5) > 8 years, and 100% (3/3) > 10 years. All patients in the PS group showed both peritoneal calcifications on abdominal CT scan and poor ultra-filtration at the time of diagnoses. Conclusion Long-term PD was the important risk factor of SEP. If both peritoneal calcification on abdominal CT scan and poor ultrafiltration are observed in a patient on PD more than 5 years, a peritoneal biopsy should be performed. If PS is detected, PD should be discontinued.