• Journal of Pharmaceutical Investigation
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• v.32 no.1
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• pp.7-11
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• 2002

The purpose of this study was to develop a new $^{l3}C-urea-containing$ capsule for diagnosis of H. pylori. The urea-containing capsules were prepared with various diluents such as polyethylene glycol (PEG), microcrystalline cellulose, sodium lauryl sulfate and citric acid. The dissolution test, $^{l3}C-urea$ breath test and stability test were then performed on the capsules. Microcrystalline cellulose and sodium lauryl sulfate retarded the initial dissolution rates of urea. However, PEG increased the initial dissolution rates of urea. Furthermore, two formulae composed of PEG, [$^{l3}C-urea/PEG$ (38/1.9 mg/cap)] and [$^{l3}C-urea/PEG/citric$ acid (38/1.9/1.9 mg/cap)] had the maximum DOB value, about 16 at 20 mim, while the formula composed of only 38 mg $^{l3}C-urea$ had the maximum DOB value at 30 min. The results indicated that PEG improved the, sensitivity of $^{l3}C-urea$ in the human volunteers. The capsule [$^{l3}C-urea/PEG$ (38/1.9 mg/cap)] was stable for at least six months in 25 and $37^{\circ}C$. Thus, a PEG-containing capsule, [$^{l3}C-urea/PEG$ (38/1.9 mg/cap)] would be a more economical, sensitive and stable preparation for diagnosis of H. pylori.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.879-883
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• 2006

To develop a $^{13}C-urea-containing$ capsule for more economic and sensitive diagnosis of Helicobacter pylori infection, the $^{13}C-urea-containing$ capsules were prepared with various additives such as polyethylene glycol, microcrystalline cellulose, sodium lauryl sulfate and citric acid. Their dissolution test and $^{13}C-urea$ Breath Test in human volunteers were then performed. Polyethylene glycol increased the initial dissolution rates of urea and difference ${\sigma}$ $^{13}C$ values from $^{13}C-urea$, while microcrystalline cellulose and sodium lauryl sulfate decreased them. Irrespective of addition of citric acid, the compositions with polyethylene glycol showed higher values from $^{13}C-urea$ compared to a commercial 76 mg $^{13}C-urea-containing$ capsule due to higher initial dissolution rate. The capsules with 38 mg $^{13}C-urea$ and 1.9 mg polyethylene glycol, which showed higher Helicobacter pylori-positive value of about $8{\textperthousand}$ at 10 min, improved the sensitivity of $^{13}C-urea$ in human volunteers. Thus, the $^{13}C-urea-containing$ capsule with polyethylene glycol would be a more economical and sensitive preparation for diagnosis of Helicobacter pylori infection.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.280.2-280.2
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• 2003

The applicability of liquid chromatography-atmospheric-pressure chemical-ionization mass spectrometry (LC-APCI-MS) for the determination of 13C-urea in 13C-urea/PEG capsules has been studied. It is essential to assess the stability of a newly developed low-dose (38 mg) 13C-urea/PEG capsule. which will be used for 13C-urea breath test (13C-UBT) to detect Helicobacter pylori infection. (omitted)

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.271-276
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• 2007

Helicobacter pylori (H. pylori) infection is common in korea and high incidence at gastric ulcer and duodenal ulcer. $^{14}C-urea$ breath test ($^{14}C-UBT$) is regarded as a highly reliable and non-invasive method for the diagnosis of H. pylori infection. The purpose of this study was to evaluate the diagnositc performance of a new and rapid $^{14}C-UBT$, which was equipped with Geiger-Muller counter and compared the results with those obtained by gastroduodenoscopic biopsies (GBx). One hundred sixty-eight patients (M : F = 118 : 50) underwent $^{14}C-UBT$, rapid urease test (CLO test), and GBx. The results of $^{14}C-UBT$ were classified as positive (>50 cpm), borderline (25$^{14}C-UBT$ or CLO test results with GBx as a glod standard. In the assessment of the presence of H. pylori infection, the $^{14}C-UBT$ global performance yielded positive predictive value, negative predictive value and accuracy of 93.3% and 83.3%, respectively. However, the CLO test had performance yielded positive predictive value, negative predictive value and accuracy of 76.9%, 50.0%, respectively. In this study $^{14}C-UBT$ is a highly accurate, simple and non-invasive method or the diagnosis of follow up H. pylori infection.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5265-5272
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• 2016

Objective: The present study was conducted to evaluate invasive and noninvasive diagnostic methods for detection of Helicobacter pylori (H. pylori) in patients admitted with dyspeptic complaints and to compare sensitivities and specificities. Method: Sets of four gastric biopsy specimens were obtained from a total of 126 patients included in the study. The presence of H. pylori was determined by invasive tests including culture, rapid urease test, polymerase chain reaction (PCR) and histopathology. Among noninvasive tests, urea breath test, serological tests and enzyme-linked immunosorbent assay (ELISA) were performed. Results: H. pylori was isolated in 79 (62.7%) gastric biopsy cultures, whereas positivity was concluded for 105 (83.3%) patients by rapid urease test, for 106 (84.1%) by PCR, for 110 (87.3%) by histopathology, for 119 (94.4%) by urea breath test, and for 107 (84.9%) by ELISA. In the present study, the culture findings and histopathological examination findings were accepted as gold standard. According to the gold standard, urea breath test had the highest sensitivity (96.5%) and the lowest specificity (30%), whereas culture and histopathology had the highest specificities (100%). Conclusion: The use of PCR invasively with gastric biopsy samples yielded parallel results with the gold standard. PCR can be recommended for routine use in the diagnosis of H. pylori.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.19 no.2
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• pp.96-103
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• 2016

Helicobacter pylori infection is acquired mainly during childhood and causes various diseases such as gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and iron deficiency anemia. Although H. pylori infection in children differs from adults in many ways, this is often overlooked in clinical practice. Unlike adults, nodular gastritis may be a pathognomonic endoscopic finding of childhood H. pylori infection. Histopathological findings of gastric tissues are also different in children due to predominance of lymphocytes and plasma cells and the formation of gastric MALT. Although endoscopy is recommended for the initial diagnosis of H. pylori infection, several non-invasive diagnostic tests such as the urea breath test (UBT) and the H. pylori stool antigen test (HpSA) are available and well validated even in children. According to recent data, both the $^{13}C$-UBT and HpSA using enzyme-linked immunosorbent assay are reliable non-invasive tests to determine H. pylori status after eradication therapy, although children younger than 6 years are known to have high false positives. When invasive or noninvasive tests are applied to children to detect H. pylori infection, it should be noted that there are differences between children and adults in diagnosing H. pylori infection.

• Korean Journal of Clinical Pharmacy
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• v.22 no.2
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• pp.160-166
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• 2012

Purpose: The purpose of the present study was to investigate the pharmacokinetics of urea, a new potential diagnosis reagent of Helicobacter pylori infection. Methods: Considering the mechanism of urea breath test, we determined the excretion of urea in expired air after its oral administration in rats and beagle dogs at the dose of 2 mg/kg (including 50 mCi/mmol $^{14}C$-urea 50 ${\mu}Ci/kg$ for rats and 13.5 ${\mu}Ci/kg$ for dogs). Results: Urea was rapidly disappeared from the blood circulation by 1 hr after its i.v. bolus injection, followed by a slow disappearance by 24 hr. The half-lives at the distributive phase ($t_{1/2{\alpha}}$) and post-distributive phase ($t_{1/2{\beta}}$) were 2 min and 6 hr, respectively. The bioavailability of urea was 64.3% after its oral administration. The values of the volume of distribution ($V_{dss}$) and the total body clearance ($CL_t$) after the oral administration were compatible with those after i.v. administration. The recovery of urea in the bile was about 0.1% of the dose by 24 hr after its oral administration. Urea was extensively eliminated in the urine by 48 hr. The recovery ratios of urea in the urine and expired air were about 86.8% and 2.99% of the dose by 48 hr, respectively. Moreover, urea was mostly distributed from the blood circulation to the kidney, followed by being eliminated in the urine without metabolism. The concentration of urea in the kidney was 4.0 times higher than that of plasma at 40 min after its oral administration. Conclusions: These findings indicated that oral route appears to be available for the administration of urea. Orally administered urea, thus, was considered to be useful for the diagnosis of Helicobacter pylori infection.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.264-265
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• 2000

Helicobacter pylori(H. pylori) is the causative agent of chronic gastritis and the single most important factor in peptic ulcer disease, however, the pathogenetic mechanisms underlying H, pylori infection are not well understood. Futhermore, there is a strong association between H. pylori infection and gastric cancer. Various diagnostic methods for detecting H. pylori infection are available. These can be divided into invasive methods, requiring endoscopy, and non-invasive tests, mainly 13C-urea breath tests and serologic detection of antibodies. Rapid urease test is the most recommendable endoscopic test for the diagnosis of H. pylori infection, presently. CLO test kit is the represent of rapid urease test kits. The principles of CLO test kit is that hydrolysis of urea by urease Is detected by a dye indicators showing a color change. Our device is used same principle but we improved the reaction time is more faster and positive color change is more distinctive from the color of the negative specimen. So, this kit is more reliable because it response faster and accuracy.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.21-25
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• 2005

Purpose: $^{14}C$-urea breath test (UBT) is a non-invasive and reliable method for the diagnosis of Helicobacter pylori (HP) infection. In this study, we evaluated the diagnostic performance of a new and rapid $^{14}C$-UBT (Heliprobe method), which was equipped with $Geiger-M\ddot{u}ller$ counter and compared the results with those obtained by using the conventional method. Materials and Methods: Forty-nine patients with dyspepsia underwent gastroduodenoscopy and $^{14}C$-UBT. A 37 KBq $^{14}C$-urea capsule was administered to patients and breath samples were collected. In Heliprobe method, patients exhaled into a Hellprobe BreathCard for 10 min. And then the activities of the BreathCard were countered using Heliprobe analyzer. In the conventional method, results were countered using liquid scintillation counter. During gastroduodenoscopy, 18 of 49 patients were underwent biopsies. According to these histologic results, we evaluated the diagnostic performance of two different methods and compared them. Also we evaluated the concordant and disconcordant rates between them. Results: In all 49 patients, concordant rate of both conventional and Heliprobe methods was 98% (48/49) and the discordant rate was 2% (1/49). Thirteen of 18 patients to whom biopsies were applied, were found to be HP positive on histologic results. And both Heliprobe method and conventional method classified 13 of 13 HP-positive patients and 5 of 5 HP-negative patients correctly (sensitivity 100%, specificity 100%, accuracy 100%). Conclusion: The Heliprobe method demonstrated the same diagnostic performance compared with the conventional method and was a simpler and more rapid technique.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.61-68
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• 2001

Purpose: The C-14 urea breath test (C-14 UBT) is the most specific noninvasive method to detect Helicobacter (H) pylori infection. We investigated if the C-14 UBT can reflect the presence and degree of H. pylori detected by gastroduodenoscopic biopsies (GBx). Materials and methods: One hundred fifty patients (M:F=83:67, age $48.6{\pm}11.2$ yrs) underwent C-14 UBT, rapid urease test (CLO test) and GBx on the same day. For the C-14 UBT, a single breath sample was collected at 10 minutes after ingestion of C-14 urea (137 KBq) capsule and counting was done in a liquid scintillation counter for 1 minute, and the results were classified as positive (${\geq}200dpm$), Intermediate ($50{\sim}199dpm$) or negative (<50 dpm). The results of CLO tests were classified as positive or negative according to color change. The results of GBx on giemsa stain were graded 0 (normal) to 4 (diffuse) according to the distribution of H. pylori by the Wyatt method. We compared C-14 UBT results with GBx grade as a gold standard. Results: In the assessment of the presence of H. pylori infection, the C-14 UBT global performance yielded sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 92.5%, 88.4%, 97.1%, 88.4% and 91.3%, respectively. However, the CLO test had sensitivity, specificity, PPV, NPV and accuracy of 83.2%, 81.4%, 91.8%, 81.4% and 82.7%, respectively. The quantitative values of the C-14 UBT were $45{\pm}27$ dpm in grade 0, $707{\pm}584dpm$ in grade 1, $1558{\pm}584dpm$ in grade 2, $1851{\pm}604dpm$ in grade 3, and $2719{\pm}892dpm$ in grade 4. A significant correlation (r=0.848, p<0.01) was found between C-14 UBT and the grade of distribution of H. pylori infection on GBx with giemsa stain. Conclusion: We conclude that the C-14 UBT is a highly accurate, simple and noninvasive method for the diagnosis of ongoing H. pylori infection and reflects the degree of bacterial distribution.