Aroma quality assessment of Korean fermented red pepper paste (gochujang) by aroma extract dilution analysis and headspace solid-phase microextraction-gas chromatography-olfactometry.

The objective of this study was to assess aroma quality of gochujang using purge and trap, simultaneous steam distillation and solvent extraction (SDE), and headspace solid-phase microextraction (HS-SPME), followed by gas chromatography-olfactometry (GC-O). Nineteen and 28 aroma-active compounds were detected by aroma extract dilution analysis of purge and trap and SDE, respectively. Diallyl disulfide and 3-isobutyl-2-methoxypyrazine played a significant role in the aroma quality of gochujang. Twelve aroma-active compounds were detected by HS-SPME-GC-O based on sample dilution analysis. Methional, diallyl disulfide, and 3-isobutyl-2-methoxypyrazine were the most intense aroma-active compounds. 3-Isobutyl-2-methoxypyrazine was identified for the first time in gochujang.

Lymphoepithelioma-like carcinoma of the urinary bladder.

A 78-yr-old woman presented with gross hematuria for 2 weeks. On cystoscopy, a frond-like mass was observed at the bladder trigone. Transurethral resection of bladder tumor was performed for the mass. Histopathological findings showed that 90% of lesions were lymphoepithelioma-like carcinoma (LELCA) and a few lesions were non-invasive transitional cell carcinoma. On microscopy, syncytial growth pattern and indistinct cytoplasmic borders were observed with the severe infiltration of lymphoid cells. The case was followed-up for 8 months without recurrence. This is the first report of a LELCA case in Korea.

Mesenteric fibromatosis causing ureteral stenosis.

Mesenteric fibromatosis is a rare benign disease characterized by proliferating fibrous tissue in the bowel mesentery. We report a case of aggressive mesenteric fibromatosis with ureteral stenosis arising in a 46-year-old woman who suffered from intermittent right abdominal pain. Computed tomography revealed a right retroperitoneal mass with right ureteral stenosis at the level of the right common iliac vessel. The mass was excised with resection of the affected segment of the ileum, ascending colon, and ureter, and end-to-end ureter anastomosis was performed. Pathological examination confirmed mesenteric fibromatosis.

The value of estimation of distal ureteral dilatation in primary vesicoureteral reflux.

PURPOSE: Recently, several studies have suggested that distal ureteral dilatation is an important factor influencing the spontaneous resolution of primary vesicoureteral reflux (VUR). We evaluated the relationship between distal ureteral dilatation and the spontaneous resolution of primary VUR. MATERIALS AND METHODS: The medical records of 114 patients with primary VUR maintained on prophylactic antibiotics from April 1999 to August 2008 were retrospectively reviewed. The patients' mean age was 24.2 months (range, 6-108 months). There were 66 male patients and 48 female patients. The mean follow-up was 37.6 months (range, 12-102 months). We analyzed various factors including age, gender, grade of reflux, laterality, and ureteral diameter ratio (UDR; the largest ureteral diameter was divided by the distance from the L1-4 vertebral body to minimize the differences in diameter by age) to determine whether these factors influenced the spontaneous resolution of primary VUR. RESULTS: Unilateral, low-grade reflux and low UDR were significantly associated with the spontaneous resolution of reflux (p=0.048, p<0.001, and p<0.001, respectively). The multivariate analysis revealed that the spontaneous resolution rate of primary reflux was significantly higher in patients with low UDR than in patients with high UDR (p<0.001). CONCLUSIONS: The degree of distal ureteral dilatation is expected to be another important factor in determining therapeutic course and predicting the spontaneous resolution of VUR.

Air-stable supported membranes for single-cell cytometry on PDMS microchips.

Protein-reinforced supported bilayer membranes (rSBMs) composed of phosphatidylcholine (PC), biotin-PE and Neutravidin were used to coat hybrid microchips composed of polydimethylsiloxane (PDMS) and glass. Since the coatings required a freshly oxidized, hydrophilic substrate, a novel method to rapidly connect reservoirs using plasma oxidation was first developed and found to support up to 5.2 N cm(-2) (1.5 N) pull-off force. rSBMs were then assembled in the oxidized hydrophilic channels. The electroosmotic mobility (mu(eo)) of rSBM-coated channels was measured over a 3 h time to evaluate the stability of the coatings for microchip electrophoresis. rSBM-coated microchips with a simple cross-design had excellent properties for microchip separations, yielding efficiencies of up to 700,000 plates m(-1) for fluorescent dyes and peptides. The separation performance of rSBM and PC-coated channels was evaluated after repeatedly drying and rehydrating the channels. The separation efficiency of fluorescein on PC-coated devices decreased by 40% after one dehydration cycle and nearly 75% after 3 cycles. In contrast for rSBM-coated devices there was no significant change in the fluorescein efficiency until the third cycle (10% decreased efficiency). rSBM-coated channels were also markedly more stable when placed in a dehydrated state during long-term storage compared to PC-coated channels, and showed reduced chip failure and no reduction in performance for up to one month of dehydrated storage. Finally, rSBM-coated devices were used to perform single-cell cytometry. Microchips that had been dehydrated, stored two weeks, and rehydrated prior to use demonstrated similar performance to newly coated devices for the separation of fluorescein and carboxyfluorescein from single cells. Thus rSBM-coated devices were rugged withstanding electric fields, prolonged storage under dehydrated conditions, and biofouling by cellular constituents while maintaining excellent separation performance.

Dietary exposure and risk assessment of mercury from the Korean total diet study.

As a national project, obtaining information on the amount of heavy metal exposure of individuals through food intake is an important basic parameter for risk assessment. This study was conducted to evaluate dietary exposure levels and various risks from mercury (Hg) in Korean foods. In total, 342 samples comprising 114 food items were collected and then cooked prior to analysis. As found by Hg analysis, the mean content of metal in the fish and shellfish group was highest among the 15 Korean food groups. The total daily amount of Hg intake from typical Korean foods was 2.40 microg/person/d. The daily amount (microg/person/d) of Hg intake from each food group was 0.155 in grains and cereals, 0.008 potatoes and starch, 0.005 sugars and sweets, 0.0093 pulses, 0.0018 nuts and seeds, 0.203 vegetables, 0.027 fruits, 0.021 meats and poultry, 0.004 eggs, 1.826 fish and shellfish, 0.022 seaweed, 0.043 milk and dairy products, 0.008 oils and fats, 0.042 beverages, and 0.023 seasonings. The fish and shellfish group contributed most to total dietary intake at 76%. For risk assessment, probable daily intake (PDI) was calculated and compared with provisional tolerable weekly intake (PTWI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The level of Hg intake through fish and shellfish of 0.001 mg/kg body weight bw/wk corresponded to 4.54% of the PTWI value of 0.005 mg/kg bw/wk, the safety standard for JECFA. The level of Hg intake through selected foods from the Food list for Koreans was 0.001 mg/kg bw/wk, corresponding to 5.95% of PTWI value. Therefore, overall intake was at levels below the recommended JECFA levels. The relative gender Hg hazard from Korean foods was 6.26% and 5.5% for males and females, respectively. The relative age Hg hazard from Korean foods was, 8.9% in those 3-6 yr old, 6.7% in those 7-12 yr old, 5.2% in those 13-19 yr old, 5.9% in those 20-29 yr old, 6.3% in those 30-49 yr old, 5.6% in those ages 50-64 yr, and 3.7% in the group of those over 65 yr of age. Relative regional Hg hazard from Korean foods was 6.3% in urban versus 5.5% in rural areas. Thus, the amount of Hg intake through consumption of Korean foods was found to be at a relatively safe level. These data may be thus used to establish safety standards for fish and shellfish consumption.

Separations in poly(dimethylsiloxane) microchips coated with supported bilayer membranes.

Hybrid microchannels composed of poly(dimethylsiloxane) and glass were coated with supported bilayer membranes (SBMs) by the process of vesicle fusion. The electroosmotic mobility (mu(eo)) of zwitterionic, positively charged, and negatively charged phospholipid membranes was measured over a 4 h time to evaluate the stability of the coatings in an electric field. Coated microchips with a simple cross design were used to separate the fluorescent dyes fluorescein and Oregon Green. Migration time reproducibility was better than 5% RSD over 70 min of continuous separations. Separation of Oregon Green and fluorescein in channels coated with zwitterionic phosphatidylcholine (PC) membranes yielded efficiencies of 611,000 and 499,000 plates/m and a resolution of 2.4 within 2 s. Both zwitterionic and negatively charged membranes were used to separate peptide substrates from their phosphorylated analogues with efficiencies of 200,000-400,000 plates/m. Notably, separations of fluorescently labeled ABL substrate peptide from its phosphorylated counterpart were achieved using a high-salt physiological buffer with near-baseline resolution in 10 s. PC-coated devices were used to successfully separate enhanced green fluorescent protein (eGFP) from a fusion protein (eGFP-Crakl) with an efficiency of 358,000 and 278,000 plates/m respectively in less than 12 s. These SBM-based coatings may enable the separation of a broad range of analytes and may be ideal in biological applications for microfluidics.