Identification of an interfering substrate in apple juice and improvement for determination of patulin with high-performance liquid chromatography analyses.

An interfering substance that is not 5-hydroxymethylfurfural appears in some apple juices during high-performance liquid chromatography (HPLC) analysis of patulin based on the AOAC 995.10 method. Because this interfering substance could cause the overestimation of patulin in the apple juices, we tried to identify the substance and to develop an improved method of analyzing patulin free from the influence of this substance. We isolated the substance from the apple juice and identified it as adenosine based on its mass spectrometry, proton nuclear magnetic resonance, and photo diode array spectra. Because of the chemical properties of adenosine, changes in the extraction method under acidic conditions and the HPLC conditions (wavelength and analytical column) were effective for avoiding the influence of adenosine and more specifically for analyzing the patulin. The most effective and simple improvement of the official method was the use of column in-point carbon contents greater than 15.5%.

The effect of left heart bypass on pulmonary blood flow and arterial oxygenation during one-lung ventilation in patients undergoing descending thoracic aortic surgery.

STUDY OBJECTIVE: To study the effect of left heart bypass (LHB) on regional pulmonary blood flow and arterial oxygenation during one-lung ventilation (OLV). DESIGN: Prospective, observational study SETTING: Operating room PATIENTS: 14 ASA physical status II and III patients scheduled to undergo descending thoracic or thoracoabdominal aortic surgery using LHB. INTERVENTIONS AND MEASUREMENTS: Parameters studied during OLV with 100% oxygen before and during LHB mean arterial pressure, heart rate, pulmonary artery pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac index, cardiac output, arterial oxygen tension (PaO(2)), mixed venous oxygen pressure, alveolar arterial oxygen difference (P((A-a)O2)), and right upper pulmonary venous flow (RUPVF). Right upper pulmonary venous flow was measured using transesophageal echocardiography. MAIN RESULTS: With the transition to OLV, there was a significant decrease in PaO(2) and a significant increase in P((A-a)O2). However once LHB was initiated, these values improved significantly (P = 0.0007 and 0.0004, respectively) with the simultaneous increase in RUPVF (P = 0.0018). CONCLUSIONS: LHB improved pulmonary blood flow to the dependent lung and arterial oxygenation during OLV in descending thoracic aortic surgery.

[Inter-laboratory study for validation of a Japanese official analytical method for determination of patulin in apple juice].

To validate a modified version of AOAC official method of analysis 995.10 as an official standard in Japan for determination of patulin in apple juice, an inter-laboratory study was performed in 11 laboratories using a non-contaminated sample, 2 naturally contaminated samples and 2 spiked samples of apple juice. For naturally contaminated apple juices, the relative standard deviations for repeatability and reproducibility were 3.2, 7.1% and 10.0, 21.7%, respectively. HORRAT values were 0.4, 0.9. The average recovery of patulin from spiked sample was 83.7%. The limit of quantification was calculated as 10 microg/kg. From these results, the method was thought to be suitable as an official standard for determination of patulin in apple juice in Japan.

Difficult laryngoscopy and cephalometric roentgenograms in obstructive sleep apnea syndrome patients undergoing uvulopalatopharyngoplasty.

We retrospectively studied the incidence of difficult laryngoscopy in 53 subjects with obstructive sleep apnea syndrome (OSAS) undergoing uvulopalatopharyngoplasty (UPPP) and 72 subjects with chronic otitis media undergoing tympanoplasty (control group). The incidence of difficult laryngoscopy in the UPPP group was significantly higher than in the control group (18.9%vs 4.2%,P<0.001). To analyze the anatomical findings of difficult laryngoscopy in UPPP patients, cephalometric roentgenograms were compared between patients in whom direct laryngoscopy was difficult (difficult patients,n=10) and patients in whom direct laryngoscopy was not difficult (nondifficult patients,n=43). Cephalometric atlanto-occipital distance (cAOD) was less than 4mm in 80% of the difficult patients, and there were significant differences between the difficult patients and the nondifficult patients (2.8±3.3 mmvs 6.7±3.0 mm, mean ±SD,P<0.001). There were significant differences in cephalometric effective mandibular length/cephalometric posterior depth of mandible ratio (cEML/cPDM) between the difficult patients and the nondifficult patients (4.0±0.6vs 4.5 ±0.8,P<0.01); however, the calculation of cEML/cPDM was more difficult than cAOD. We concluded that OSAS patients undergoing UPPP are at high risk for difficult laryngoscopy, and that cAOD calculated from cephalometric roentgenograms is an easy and sensitive predictive indicator for the estimation of difficult laryngoscopy.