Jye-Bin Lin

Seroprevalence of Helicobacter pylori infection among schoolchildren and teachers in Taiwan.

Background:  Helicobacter pylori are associated with chronic antral gastritis that is related to duodenal ulcer, gastric ulcer, and probably gastric adenocarcinoma. Infection of H. pylori during childhood is considered an important risk factor for gastric carcinoma in adult life.

Seroepidemiology of hepatitis A virus infection among schoolchildren in Taiwan

Taiwan was a hyperendemic area for hepatitis A virus (HAV) infection before 1980. The aim of this study was to examine the association between seropositivity of antibodies against HAV (anti‐HAV) by a community‐based survey. School children from 10 elementary and 3 junior high schools, as well as staff members who worked at the above schools in central Taiwan were selected at random in this study. Anti‐HAV was tested in sera of 1,954 healthy schoolchildren (aged 7–15 years old) and 254 teachers by enzyme‐linked immunosorbent assay. Schoolchildren had a low prevalence of anti‐HAV (2.3%) in contrast to the high seroprevalence in their teachers (52%). The seropositive rates of HAV antibody among the study subjects were increasing with age. No significant differences of anti‐HAV seroprevalence among the study subjects were observed when they were stratified by gender, geographical area, household members, and parental education. Whereas, the anti‐HAV seroprevalence was significantly higher in schoolchildren who were either aboriginal or living in areas without a supply of drinking tap‐water. The seroprevalence of HAV data among the healthy pediatric population would be helpful to evaluate the need for mass vaccination policies. J. Med. Virol. 83:196–200, 2011.

Pediatric Reference Intervals for Several Biochemical Analytes in School Children in Central Taiwan

BACKGROUND/PURPOSE Reference intervals of biochemical tests for screening for diabetes mellitus and liver and renal function among school children in Central Taiwan have never been documented. Therefore, this study aimed to establish the reference intervals for the above mentioned biochemical tests for pediatric populations. METHODS A total of 4326 subjects, including 2029 kindergarten children, 1624 elementary-school children, 325 junior-high-school children, and 348 teachers were selected randomly in Central Taiwan. All serum alanine aminotransferase (ALT), blood urea nitrogen (BUN), creatinine (Cr) and glucose levels were determined using a Beckman Synchron CX5 analyzer. The reference intervals reflected estimates of the 2.5th-97.5th percentiles of non-parametric distributions. RESULTS Adults had significantly higher biochemical analyte values [except for BUN/creatinine (B/C) ratio] than children had. Multiple logistic regression analysis showed that biochemical analyte values were significantly higher in male than in female subjects. The concentrations of glucose and Cr increased with age. On the contrary, the B/C ratio decreased with age. CONCLUSION Our study provides new pediatric reference intervals (2.5th-97.5th percentiles) of 60-99 mg/dL for serum glucose concentrations, 8-38 IU/L for ALT, 0.4-1.1 mg/L for Cr, 8.7-18.0 mg/L for BUN, and 10-34 for B/C ratio. The B/C ratio in children was higher than those of adults, possibly due to that children had a higher intake of protein.

Radiation dose for normal organs by helical tomotherapy for lung cancer.

This study derived a simple equation of effective dose (E) versus normal organ of patients with varying body weights undergoing lung cancer treatment of helical tomotherapy (TOMO). Five tissue-equivalent and Rando phantoms were used to simulate lung cancer patients. This study then measured E and equivalent dose of organ or tissues (DT) using thermoluminescent dosimetry (TLD-100H). The TLD-100H was calibrated using TOMO 6MV photons, then inserted into phantom positions that closely corresponded with the position of the represented organs and tissues. Both E and DT were evaluated by ICRP 103. Peripheral doses varied markedly at positions close to the tumor center. The maximum statistical and total errors were 16.7-22.3%. This analytical result indicates that E of Rando and tissue-equivalent phantoms was in the ranged of 9.44±1.70 (10kg) to 4.58±0.83 (90kg)mSv/Gy. Notably, E decreased exponentially as phantom weight increased. Peripheral doses were also evaluated by TLD as a function of distance from the tumor center. Finally, experimental results are compared with those in literature. These findings will prove useful to patients, physicians, radiologists, and the public.

Evaluating environment radiations at Axesse linac undergoing NPC treatment of VMAT

Abstract Environment radiations in vault rooms resulting from Axesse linac use was assessed at Medical University Hospital using Thermoluminescent dosimeters (TLDs) during the use of the new radiation treatment known as volumetric modulated arc therapy (VMAT) in the treatment of nasopharyngeal cancer (NPC). The TLD-100H was calibrated using linac 6 MV photons. A total of 75 measurement points of the TLD-100H were utilized for environmental monitoring. The measured environment radiations were then visualized as three-dimensional graphical representations. Environment radiations were visualized using colored three-dimentional graphical representations. The radiations in NPC treatment of Rando phantom was found to reach levels up to 370 mSv/treatment. Many researchers consider TLD, which is the most cost-effective method to environment radiations. The minimum detectable dose (MDD) was also identified to demonstrate the reliability of the TLD approach. Quantitative results that provide practical guidance with regarded radiation protections. Potentially hazardous of secondary radiations from the operating linac is evaluated with regard to its potential health effects on both patients and the public. KEY POINTS This work tried to evaluate the environment radiation and minimal detectable limit of TLD inside the LINAC maze.

Evaluating air kerma at a medical cyclotron after refined shielding design using the TLD approach

Cyclotrons are increasingly constructed at medical universities in Taiwan to produce nuclear medicine. However, their operation generates amounts of highly energetic photons from 18O(p, γn)18F reactions. This reaction posed a health hazard to the public. Chung Shan University Hospital had to increase its 2-deoxy-2-[18F]-fluoro-D-glucose products in 2011 to 11.5 times that in 2004 and redesign the self-shielded (CTI) Radioisotope Delivery System (RDS)-111 to meet guild requirements regarding the production of positron emission tomography (PET). This study is the first to evaluate air kerma in a CTI RDS-111 cyclotron center with a thermoluminescent dosimeter (TLD). Air kerma of up to 17.0±2.8 mGy/mo indicated that heavy leakage of photons penetrated the PET/CT facility. The new L-shaped concrete shield and added d2 door can adequately protect the public. The minimum detectable limit of air kerma is discussed to demonstrate the reliability of the TLD approach.