A revised method for determination of dialkylphosphate levels in human urine by solid-phase extraction and liquid chromatography with tandem mass spectrometry: application to human urine samples from Japanese children

Objectives

Biological monitoring of organophosphorus insecticide (OP) metabolites, specifically dialkylphosphates (DAP) in urine, plays a key role in low-level exposure assessment of OP in individuals. The aims of this study are to develop a simple and sensitive method for determining four urinary DAPs using high-performance liquid chromatography with tandem mass spectrometry (LC–MS/MS), and to assess the concentration range of urinary DAP in Japanese children.

Methods

Deuterium-labeled DAPs were used as internal standards. Urinary dimethylphosphate (DMP) and diethylphosphate (DEP), which passed through the solid-phase extraction (SPE) column, and dimethylthiophosphate (DMTP) and diethylthiophosphate (DETP), which were extracted from a SPE column using 2.5 % NH₃ water including 50 % acetonitrile, were prepared for separation analysis. The samples were then injected into LC–MS/MS. The optimized method was applied to spot urine samples from 3-year-old children (109 males and 116 females) living in Aichi Prefecture in Japan.

Results

Results from the validation study demonstrated good within- and between-run precisions (<10.7 %) with low detection limits (0.4 for DMP and DMTP, 0.2 for DEP and 0.1 μg/L for DETP). The geometric mean values and detection rates of the urinary DAPs in Japanese children were 14.4 μg/L and 100 % for DMP, 5.3 μg/L and 98 % for DMTP, 5.5 μg/L and 99 % for DEP, and 0.6 μg/L and 80 % for DETP, respectively.

Conclusions

The present high-throughput method is simple and reliable, and can thereby further contribute to development of an exposure assessment of OP. The present study is the first to reveal the DAP concentrations in young Japanese children.     

Non‐invasive three‐dimensional power Doppler imaging for the assessment of acute cerebral blood flow alteration in a mouse model of subarachnoid haemorrhage

We aimed to evaluate the feasibility of a non‐invasive method of cerebral blood flow (CBF) measurement using high‐frequency power Doppler ultrasound imaging in a mouse model of subarachnoid haemorrhage (SAH). The 3‐dimensionally (3D) reconstructed blood flow signals (%vascularity) within the brain volume of the middle cerebral artery territory correlated well with reference parameters, baseline carotid artery blood flow (r² = 0.52, P < 0.0001) and normalized CBF changes (r² = 0.74 P < 0.0001). These data suggest that the 3D power Doppler analysis may have the potential for reflecting real‐time CBF changes during the acute phase of experimental SAH, which may be applicable to preclinical studies on early brain injury.     

Endoscopic ultrasound with double-balloon endoscopy in the evaluation of small-bowel disease

Background

Double-balloon endoscopy (DBE) has become a new standard in enteroscopy. However, it may be difficult to make a diagnosis or plan treatment strategy with endoscopic visualization alone. The addition of endoscopic ultrasonography (EUS) has the potential to improve the ability to establish the diagnosis and develop a treatment strategy. The present study was conducted to assess the feasibility and usefulness of EUS with DBE.

Methods

EUS with DBE was performed in 31 of 891 patients who underwent DBE from July 2004 to March 2011 at Jichi Medical University Hospital. We analyzed the EUS findings for lesions and evaluated the usefulness of EUS considering the following three factors: qualitative diagnostic value for lesions, depth grading of lesions, and evaluation of the structure of severe strictures prior to endoscopic balloon dilation.

Results

EUS was performed for 31/32 lesions (97 %) in 31 patients. EUS findings were informative for 29/32 lesions (91 %). EUS findings were useful for establishing a qualitative diagnosis in 15/25 lesions (60 %). EUS findings for depth grading provided useful information for determining the therapeutic strategy in 11/13 lesions (85 %). EUS with DBE was useful in the evaluation of strictures for all six lesions (100 %). The overall usefulness of EUS with DBE on decision making was 72 % (23/32) in this study.

Conclusions

EUS with DBE is feasible and useful. It provides additional information on small-bowel disease and contributes to establishing a precise diagnosis and selection of an appropriate therapeutic strategy.     

T cell receptor vβ repertoire of double-negative α/β t cells in patients with systemic sclerosis

Objective. To analyze the T cell receptor V_β gene on double-negative (DN) α/β T cells, which are increased in number, on peripheral blood lymphocytes (PBL) from patients with systemic sclerosis (SSc). Methods. The DN α/β T cells were sorted by flow cytometry from PBL obtained from 3 patients with SSc. The V_β repertoire was analyzed by polymerase chain reaction. Results. Only 1 or 2 V_β genes (V_β5/7, 5, or 17) were predominantly expressed on DN α/β T cells from these 3 patients. Conclusion. The V_β repertoire on DN α/β T cells in PBL from patients with SSc is rather restricted.     

Phenol-based endoscopic ultrasound-guided celiac plexus neurolysis for East Asian alcohol-intolerant upper gastrointestinal cancer patients:A pilot study

AIM:To investigate the effectiveness of phenol for the relief of cancer pain by endoscopic ultrasound-guided celiac plexus neurolysis(EUS-CPN).METHODS:Twenty-two patients referred to our hospital with cancer pain from August 2009 to July 2011for EUS-CPN were enrolled in this study.Phenol was used for 6 patients with alcohol intolerance and ethanol was used for 16 patients without alcohol intolerance.The primary endpoint was the positive response rate(pain score decreased to≤3)on postoperative day 7.Secondary endpoints included the time to onset of pain relief,duration of pain relief,and complication rates.RESULTS:There was no significant difference in the positive response rate on day 7.The rates were 83%and 69%in the phenol and ethanol groups,respectively.Regarding the time to onset of pain relief,in the phenol group,the median pre-treatment pain score was 5,whereas the post-treatment scores decreased to 1.5,1.5,and 1.5 at 2,8,and 24 h,respectively(P<0.05).In the ethanol group,the median pre-treatment pain score was 5.5,whereas the post-treatment scores significantly decreased to 2.5,2.5,and 2.5 at 2,8,and24 h,respectively(P<0.01).There was no significant difference in the duration of pain relief between the phenol and ethanol groups.No significant difference was found in the rate of complications between the 2groups;however,burning pain and inebriation occurred only in the ethanol group.CONCLUSION:Phenol had similar pain-relieving effects to ethanol in EUS-CPN.Comparing the incidences of inebriation and burning pain,phenol may be superior to ethanol in EUS-CPN procedures.