Determination of acibenzolar-S-methyl and its acidic metabolite in soils by HPLC-diode array detection.

A simple and accurate method for the analysis of acibenzolar-S-methyl (benzo[1,2,3]thiadiazole-7-carbothioic acid-S-methyl ester; CGA 245 704; ASM) and its major conversion product, benzo[1,2,3]thiadiazole-7-carboxylic acid (CGA 210 007; BTC), in soils is presented. ASM extraction from soil samples was performed using acetonitrile and BTC was extracted with a mixture of potassium phosphate buffer (0.5 M, pH 3) and acetonitrile (70:30 %, v/v). Both extracts were directly analyzed in a high-performance liquid chromatography-diode array detection (HPLC-DAD) system. Pesticide separation was achieved on a C18 (4.6 mm × 150 mm, 5 µm) analytical column with a isocratic elution of acetonitrile:water 40:60 % (v/v) with 0.6 mL L⁻¹ acetic acid at a flow rate of 1 mL min⁻¹. Linear regression coefficients (r (2)) of the external calibration curves were always above 0.9997. The limits of detection (LOD) and quantification (LOQ) of the method were 0.005 and 0.02 mg kg⁻¹ for ASM, and 0.01 and 0.05 mg kg⁻¹ for BTC, respectively. Recoveries were investigated at six fortification levels and were in the range of 90-120 % for ASM and 74-96 % for BTC with relative standard deviations (RSDs) below 11 % in all cases. The method was also validated by analyzing freshly spiked soil samples with 2.7% organic matter content at 0.5 mg kg⁻¹ level, with slightly lower recovery values only for ASM. Moreover, recoveries for intermediate aged residues of the analytes were similar to fresh residues. This method was also applied to determine ASM half-life (t(½) = 8.7 h) and the rate of the acidic metabolite formation.

One-lung ventilation and HIF1alpha expression in lung cancer and pneumothorax.

BACKGROUND/AIM: A prospective study was designed to investigate the effects of anesthesia, particularly that of the one-lung ventilation procedure (OLV), on the expression of hypoxia-inducible factor 1alpha (HIF1alpha) in patients with lung carcinomas and pneumothorax. MATERIALS AND METHODS: The immunohistochemical expression of HIF1alpha was studied in formalin-fixed paraffin-embedded tissues from 60 patients who had undergone thoracic surgery for lung cancer (n=48) or pneumothorax (n=12) under OLV general anesthesia. RESULTS: There was a significant, and rather unexpected, association of HIF1alpha expression with high body mass index (BMI) (p=0.01) and high body weight (p=0.01) of patients with lung carcinomas, but other anesthesia-related parameters, including analysis of arterial oxygen partial tension and anthropometric factors remained insignificant. With regard to pneumothorax cases, these were immunohistochemically unreactive and, hence, no relationship was noted between HIF1alpha and anesthesia parameters. CONCLUSION: Anesthesia and OLV procedure performed for lung cancer or pneumothorax does not affect the expression of HIF1alpha. However, the significant link between high BMI and HIF1alpha expression noted in patients with lung carcinomas brings forward a possible connection between obesity and hypoxia-related molecular pathways.

Incidence and etiology of rhinosinusitis in children.

The authors discuss the incidence of chronic rhinosinusitis in children. From the study of 196 CT-scans, there follows that as well the ethmoidal as the maxillary sinuses are involved in the young child. In older children, however, the incidence of maxillary sinusitis is more frequent. The etiology of chronic rhinosinusitis is discussed stressing the importance of general factors such as environmental factors, congenital and acquired abnormalities and the influence of drugs, as well as of local factors such as again environmental factors, malformations, and upper respiratory infections. Most of these factors are discussed following personal studies.