Usefulness and Limitations of a Serum Screening System to Predict the Risk of Gastric Cancer.

Objective The aim of the present study was to evaluate the effectiveness and limitations of a serum screening system for predicting the risk of gastric cancer. Methods Serum pepsinogen I (PG I)/pepsinogen II (PG II) and Helicobacter pylori (HP) antibody levels were measured. Subjects were classified into four groupsaccording to their serological status (the ABC classification system). The grade of atrophic gastritis was assessed endoscopically. We evaluated gastric cancer detection rates according to the ABC classification system and the endoscopic grade of atrophy. Patients Individuals who underwent esophagogastroduodenoscopy (EGD) in a health check were prospectively enrolled in the present study. Results According to the ABC classification system, the gastric cancer detection rates in groups A, B, C, and D were 0.07% (4/6,105), 0.5% (8/1,739), 0.8% (16/2,010), and 1.1% (3/281), respectively. The gastric cancer detection rates in subjects with no atrophy, closed type (C-type) atrophy, and open type (O-type) atrophy were 0% (0/4,567), 0.2% (4/2,581), and 0.9% (27/2,987), respectively. In group A (HP(-)/PG(-)), the proportions of subjects with no atrophy, C-type atrophy, and O-type atrophy were 71.2%, 22.8%, and 6.0%, respectively. In group A, the gastric cancer detection rates in subjects with no atrophy, C-type atrophy, and O-type atrophy were 0%, 0.07%, and 0.8%, respectively. Conclusion The ABC classification system is useful for predicting the risk of gastric cancer. However, this system was limited in group A, which included individuals with a high risk of developing gastric cancer. An endoscopic diagnosis of atrophy may be more effective than the ABC classification system for predicting the risk of gastric cancer.

Simultaneous determination of gastric cancer biomarkers pepsinogen PGI/PGII using element tagged immunoassay coupled with inductively coupled plasma mass spectrometry detection.

OBJECTIVES: In this study, a new immunoassay for the simultaneous determination of pepsinogen I (PGI) and pepsinogen II (PGII) in serum based on element labeling strategy coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection was proposed. METHODS: The sandwich-type immunoassay was used to simultaneously detect PGI and PGII in serum. PGI and PGII were captured by anti-PGI and anti-PGII antibody immobilized on the magnetic beads and then banded with Eu3+ labeled anti-PGI detection antibody and Sm3+ labeled anti-PGII detection antibody, followed by ICP-MS detection. RESULTS: The linear correlation coefficient (R2 ) of PGI and PGII standard curves was .9938 and .9911, with the dynamic range of 0-200 ng/mL and 0-60 ng/mL, respectively. The limit of detection for PGI and PGII was 1.8 ng/mL and 0.3 ng/mL, respectively. The average recovery was 101.41% ± 6.74% for PGI and 101.47% ± 4.20% for PGII. Good correlations were obtained between the proposed method and CLIA (r = .9588 for PGI, r = .9853 for PGII). CONCLUSIONS: We established a mass spectrometry-based immunoassay for the simultaneous detection of PGI and PGII in a single analysis. The element tagged immunoassay coupled with ICP-MS detection has high sensitivity, accuracy, and specificity in clinical serum sample analysis.

Gastric adenocarcinoma of the fundic gland (chief cell-predominant type): A review of endoscopic and clinicopathological features.

Gastric adenocarcinoma of the fundic gland (chief cell-predominant type, GA-FG-CCP) is a rare variant of well-differentiated adenocarcinoma, and has been proposed to be a novel disease entity. GA-FG-CCP originates from the gastric mucosa of the fundic gland region without chronic gastritis or intestinal metaplasia. The majority of GA-FG-CCPs exhibit either a submucosal tumor-like superficial elevated shape or a flat shape on macroscopic examination. Narrow-band imaging with endoscopic magnification may reveal a regular or an irregular microvascular pattern, depending on the degree of tumor exposure to the mucosal surface. Pathological analysis of GA-FG-CCPs is characterized by a high frequency of submucosal invasion, rare occurrences of lymphatic and venous invasion, and low-grade malignancy. Detection of diffuse positivity for pepsinogen-I by immunohistochemistry is specific for GA-FG-CCP. Careful endoscopic examination and detailed pathological evaluation are essential for early and accurate diagnosis of GA-FG-CCP. Nearly all GA-FG-CCPs are treated by endoscopic resection due to their small tumor size and low risk of recurrence or metastasis.

Chicken and rabbit antibodies against porcine pepsinogen A.

Isolated porcine pepsinogen A was used for the preparation of polyclonal rabbit and polyclonal chicken anti-pepsinogen A antibodies. Immunochemical properties of both immunoglobulin fractions were compared. The rabbit anti-serum was further purified using immobilized porcine pepsinogen A on magnetic cellulose beads and the resulting anti-pepsinogen A fraction proved to be applicable for the separation and the determination of porcine pepsinogen A. In contrary, antibodies prepared from chicken eggs by the same way have been found not suitable for the evaluation of the pepsinogen A level. Unexpectedly, the pre-immune fraction of chicken antibodies showed reactivity against porcine pepsinogen A and the affinity separation of specific polyclonal chicken anti-pepsinogen A antibodies on immobilized porcine pepsinogen A did not result in an enrichment of anti-pepsinogen A antibodies.

[Clinical and laboratory evaluation of efficiency of Helicobacter pylori eradication].

AIM: To assess the efficiency of eradication therapy in long-term period using the main signs of functional activity of gastric mucosa (gastrin-17, pepsinogen I, pepsinogen II) and serum antibodies to H. pylori. MATERIALS AND METHODS: 113 patients with chronic gastritis were examihed using clinical, endoscopic and laboratory-based methods of investigation, including GastroPanel Biohit, Finland. RESULTS: It was observed that after 12 month of successful eradication therapy the titer of IgG to H. pylori did not exceed 60 IU/l, with pepsinogen I and pepsinogen II cut-off values set under 150 microg/l and 15 microg/l respectively. CONCLUSION: The decrease of the titer of IgG to H. pylori and concentrations of pepsinogen I and II can be used as criteria of successful eradication therapy in long-term period.

The use of clinical, histologic, and serologic parameters to predict the intragastric extent of intestinal metaplasia: a recommendation for routine practice.

BACKGROUND: Surveillance of intestinal metaplasia (IM) of the gastric mucosa should be limited to patients at high risk of gastric cancer. Patients with extensive IM are at increased cancer risk; however, the intragastric extent of IM is usually unknown at the time of the initial diagnosis. OBJECTIVE: To assess the predictive value of clinical, histologic, and serologic parameters for the intragastric extent of IM. DESIGN AND SETTING: Prospective, multicenter study. PATIENTS: Eighty-eight patients with a previous diagnosis of IM of the gastric mucosa. INTERVENTION: Surveillance gastroscopy with extensive random biopsy sampling. MAIN OUTCOME MEASUREMENTS: Biopsy specimens were evaluated according to the Sydney classification system. In addition, serologic testing of Helicobacter pylori and cagA status, pepsinogens I and II, gastrin, and intrinsic factor antibodies was performed. The association between the available parameters and extensive IM was evaluated with logistic regression analysis. RESULTS: In 51 patients (58%), IM was present in the biopsy specimens from at least 2 intragastric locations. The most important predictors of extensive IM were a family history of gastric cancer, alcohol use > or = 1 unit/d (1 glass, approximately 10 mL or 8 g ethanol), moderate or marked IM of the index biopsy specimen, and a pepsinogen I to II ratio < 3.0. A simple risk score based on these factors could identify extensive IM in 24 of 25 patients (sensitivity 96%). LIMITATION: A prospective cohort study should confirm the proposed risk stratification. CONCLUSIONS: A risk score of clinical, histologic, and serologic parameters can predict extensive intragastric IM and may serve as a practical tool to select patients for surveillance endoscopy in routine clinical practice.

Electrochemical microdevice with separable electrode and antibody chips for simultaneous detection of pepsinogens 1 and 2.

An electrochemical microdevice with separable electrode and antibody chips has been developed and applied to detect atrophic gastritis-related proteins, pepsinogen 1 (PG1) and pepsinogen 2 (PG2), based on sandwich-type enzyme-linked immunosorbent assays (ELISAs) with horseradish peroxidase (HRP)-labeled antibody. To fabricate the electrochemical device for simultaneous analysis of several proteins, the electrode chip with eight electrode elements was assembled along with an antibody chip with eight cavities containing immobilized anti-PG1 or anti-PG2. The immunoreactions occurring in the cavities of the device were detected simultaneously by amperometry. The labeled HRP in the cavity in the presence of hydrogen peroxide catalyzed the oxidation of ferrocenemethanol (FMA) to FMA+, which was detected electrochemically by the electrode chip. The amperometric responses of respective cavities in the device increased with increasing concentration of PG1 or PG2 of 0-50 ng/ml, ensuring the simultaneous detection of PG1 and PG2. The detection limits for both PG1 and PG2 were 0.6 ng/ml (S/N=2). The electrode chip was recovered easily by disassembling the electrochemical device; thereby, it was used repeatedly, whereas the antibody chip was discarded. No marked decrease in electrochemical responses was detected after repeated use. Reuse of the electrode chip is beneficial to reduce costs of protein analysis.

Age-dependent changes in the response of the stomach to thyroidal signaling in developmentally arrested larval summer flounder.

Thyroid-dependent stomach development occurs between approximately 35 and 50 days post-hatch (dph) in laboratory-reared summer flounder larvae. The process can be blocked by thiourea (TU), and TU effects are reversed by exogenous thyroxine (T4). To establish whether a window of sensitivity exists for T4-dependent gastric development, we arrested development of larvae with 0.39 mM TU given from 26 to 61dph, and measured weekly the developmental response of the stomach to 13 nM T4 for 0, 2, or 7 days. We examined cell proliferation in surface epithelium, gastric glands, and connective tissue, pepsinogen immunoreactivity in gastric glands, and Ulex Europaeus I (UEA I) lectin staining of gastric mucous neck cells, indicative of mucous content. In 26-47dph larvae, cell proliferation was increased 5- to 10-fold in all cell types after 2 days in T4, and returned to pretreatment values by 7 days of treatment. In 54dph fish, however, the proliferative response of gastric gland and surface epithelial cells decreased significantly from that of younger fish, while that of connective tissue was unchanged. For the differentiation markers, T4-induced mucous content increased at 54dph, but not in older fish, while pepsinogen induction was not different at any of the ages tested. The age interval between 47 and 54dph corresponds with the completion of gastric development in spontaneously metamorphosing larvae. The findings suggest that a critical window exists for the mitogenic actions of T4 in epithelial cells, but not for connective tissue cells, whereas no critical period was found for markers of differentiation.

An improved radioimmunoassay for measurement of pepsinogen in porcine blood samples.

The study was conducted to develop a sensitive and specific radioimmunoassay (RIA) for the measurement of pepsinogen in porcine serum, and to use this test for the determination of pepsinogen concentrations in serum samples from fetuses and pigs of different ages. Compared to a previously described RIA, major improvements were made concerning the use of specific polyclonal antibodies and the use of an appropriate buffer. The assay was able to detect pepsinogen concentrations of >/=0.2 ng/mL. The recovery of pepsinogen was close to 95%. The intra-assay coefficients of variations ranged between 3.9 and 7.5% whereas the interassay ranged between 8.8 and 11.9%. These percentages correspond to a satisfactory accuracy and reproducibility of the assay. No cross-reactions were observed with the main commercially available products of the aspartic proteases family except porcine pepsin cross-reacted over 62.5 microg/mL. Pepsinogen concentrations increased steadily with increasing age of the fetuses and the pigs (P<0.05). Pepsinogen concentrations (+/-SE) in fetuses of 90-100 (n=24) and 100-110 days of pregnancy (n=36) were 0.5+/-0.1 and 5.3+/-1.3 ng/mL, respectively. In pigs of 21, 98, and 213 days of age, the pepsinogen concentrations were 290.6+/-10.8, 343.1+/-17.9 and 383.5+/-15.3 ng/mL, respectively. The results demonstrate that RIA is accurate and can be used easily to assess pepsinogen concentrations in pig sera. The test may constitute a valuable tool in epidemiological surveys and in studies related to gastric diseases in pigs.

Detection of luciferase having two kinds of luminescent colour based on optical filter procedure: application to an enzyme immunoassay.

This paper reports on our study using several optical filters known to be efficient in separating compounds having various levels of maximum luminescence, to separate information from three kinds of Luciola lateralis luciferase with a maximum luminescence of 559 nm, 604 nm and 607 nm. Simultaneous luminescence of Luciola lateralis luciferase was determined by measuring the luminescence through a band pass filter or sharp cut filter (BPB50, 53, 58, No.58, SC58, 60, 62, 64). It was possible to determine luciferase with a maximum luminescence lambda(max) of 559 nm (yellow-green) utilizing the band pass filter (BPB 50), described here. Meanwhile, luciferase with a lambda(max) of 607 nm (red) could be determined by calculations based on the bioluminescent intensity through the band pass filter and sharp cut filter (SC58). In addition, we also applied a simultaneous bioluminescent enzyme immunoassay of pepsinogen I (PGI) and pepsinogen II (PGII) in which two kinds of biotinylated luciferase (Luciola lateralis) labelled as an enzyme producing yellow-green light (lambda(max) = 559 nm) and red light (lambda(max) = 607 nm) were used. In the proposed method, PGI and PGII in serum were simultaneously captured in a sandwich-type immune reaction between anti-PGI and anti-PGII monoclonal antibody-coated magnetic particles, and streptavidin-biotinylated luciferase biotinylated anti-PGI and anti-PGII monoclonal antibodies triplexes, respectively. The result was a calibration range for PGI of 2-200 ng/mL, and for PGII of 1-100 ng/mL. In conclusion, the correlation of PG values in serum between the proposed method (simultaneous assay) and an individual specific bioluminescent immunoassay (specific assay) were satisfactory.

Serum antibodies to H+,K+-ATPase, serum pepsinogen A and Helicobacter pylori in relation to gastric mucosa morphology in patients with low or low-normal concentrations of serum cobalamins.

OBJECTIVES: To compare the diagnostic performance of serum antibodies to H+,K+-ATPase (EC 3.6.1.36), serum pepsinogen A (EC 3.4.23.1) and the Schilling test in diagnosing chronic atrophic body gastritis; to study the interrelationships between H+,K+-ATPase antibodies, serology for Helicobacter pylori, and gastric morphology. DESIGN: Patients with suspected cobalamin deficiency and serum cobalamin < 200 micromol/l were investigated using upper gastrointestinal endoscopy, the Schilling test and serum tests for H+,K+-ATPase antibodies, pepsinogen A, and H. pylori. SETTING: The Department of Internal Medicine, Sahlgrenska University Hospital, Göteborg, Sweden. PATIENTS: Ninety seven consecutively referred patients. MAIN OUTCOME MEASURES: Sensitivity and specificity of assays for serum H+,K+-ATPase antibodies, serum pepsinogen A, and the Schilling test. RESULTS: Assays of serum antibodies to H+,K+-ATPase and of serum pepsinogen A displayed equal diagnostic sensitivity for atrophic gastritis (around 0.90 for the severe forms) and higher than that for the Schilling test (0.65). The diagnostic specificity for pepsinogen A (1.0) was higher than for H+,K+-ATPase antibodies (about 0.80). The prevalence of antral gastritis and positivity for H. pylori antibodies declined with the transition of body gastritis into severe atrophy, while the prevalence of H+,K+-ATPase antibodies increased. CONCLUSION: Pepsinogen A is preferable to serum H+,K+-ATPase antibodies in the diagnosis of gastric body mucosal atrophy. The formation of H+,K+-ATPase antibodies does not seem to be a primary event in the development of gastric body muscosal atrophy.