A study on the epithelial proliferation in Helicobacter pylori associated gastric premalignant and malignant lesions / 대한내과학회지

BACKGROUND: Many studies have demonstrated that increased cell proliferation in gastric epithelium is associated with Helicobacter pylori (H. pylori) infection. Increased epithelial proliferation is one of the earliest mucosal changes observed in gastric carcinogenesis. The aim of this study was to evaluate the influence of H. pylori infection for epithelial proliferation at different stages of gastric carcinogenesis from chronic gastritis to adenocarcinoma. METHODS: Gastric biopsy specimens were collected from 129 patients who underwent esophagogastroduodenoscopy with biopsy. Histologically, there were 29 patients with chronic gastritis, 26 chronic gastritis with intestinal metaplasia, 31 low grade dysplasia, 18 high grade dysplasia, and 25 gastric adenocarcinoma. Status of H. pylori infection was determined by rapid urease test, modified Giemsa stain and 13C-urea breath test. Epithelial cell proliferation was assessed by immunohistochemical method using anti-PCNA antibody. RESULTS: The grade of epithelial proliferation was higher in H. pylori infected patients than uninfected patients (p=0.007) and progressively increased at different stages from chronic gastritis to gastric adenocarcinoma (p<0.001). The analysis of epithelial proliferation according to H. pylori infection status in each histologic group showed that the grades of epithelial proliferation were higher in H. pylori infected patients than uninfected patients in all groups except adenocarcinoma group. CONCLUSION: H. pylori infection causes increased gastric epithelial cell proliferation and may play an important role in gastric carcinogenesis.

PCNA Expression as a Prognostic Factor in Papillary Thyroid Carcinoma / 대한내분비외과학회지

PURPOSE: Assessment of the proliferative ability of cancer cells is necessary not only for the biologic characterization of tumors, but also for the selection of treatment and evaluation of prognosis. Recently, there have been several studies examining the proliferative activity of various malignant tumors using immunohistochemical methods. PCNA is a nuclear protein related to the cell cycle and found with high expression in proliferative tissues, including cancers. METHODS: In our study, to evaluate whether PCNA expression was useful as a prognostic factor in patients with papillary thyroid carcinoma, we quantitated the immunohistochemical expression of PCNA in the formalin-fixed paraffin embedded tissue from 55 patients with papillary thyroid carcinoma and correlated the results with established clinicopathologic parameters. RESULTS: The results were as follows. 1) PCNA expression in papillary thyroid carcinoma did not correlate with the age, sex or metastatic L/N activity of the patient, nor with the size, invasion, or recurrence of the tumor. 2) There was a close relationship between the expression rate of PCNA in thyroid tumor cells and that in metastatic L/N cells (p=0.056, in p<0.1). 3) The expression of PCNA in the metastatic L/N (+) group was higher than in the metastatic L/N (+) group (p=0.045). CONCLUSION: It is suggested that PCNA expression is not an appropriate prognostic factor in papillary thyroid carcinoma.

Expression Of Proliferating Cell Nuclear Antigen And Type I Collagen In The Elongated Bone In The Mandible Of Adult Mongrel Dogs

The purpose of this experiment was to examine the histological changes and the pattern of expression of proliferating cell nuclear antigen(PCNA) and type I collagen in the elongated bone affected by osteodistraction of the mandibular body in an adult canine model. Seven adult male mongrel dogs weighing over 20kg were used for this experiment. The author excluded 3 animals because they died before the planned time of sacrifice. The custom-made linear extraoral device and 4 bicortical fixation screws 2.3mm in diameter, 50mm in total length, 15mm in screw length were used in each animal. The distal part of the distractor produced a 0.75mm gap between proximal and distal bony segments every 360 degrees.turn of the rotation rod of the device. The mandibular body of the right side from each animal was experimental side and the left side was left intact and served as control. At the experimental side, the mandibular body was osteotomized. After 5-day latency period, the segments were distracted with a rate of 1.1mm/day and a rhythm of two/day for ensuing 7 days. The animals were sacrificed at the 4th. 17th, and 32th day after the end of the distraction. The bony specimens were decalcified, embedded in paraffin, sectioned 5micrometerthick and stained with Masson trichrome and examined under the light microscope. The immunohistochemical examinations using anti-PCNA antibody and anti-type-I collagen antibody were performed to examine the pattern of the expression of PCNA and type I collagen, respectively, . RESULTS: 1. The mean increment of the distance between the proximal and distal screw-holding parts of the distractor was 6.8mm. The average elongation of the mandible in the expermental side was 5.3mm. The loss of elongation was 1.5mm in average. 2. New bone was already observed at the 4th. day after the end of distraction. But, bony union was not completed in the distraction gap at the 32th. day after the end of distraction by radiographic and microscopic examinations. 3. The expression rate of PCNA positive cells in the distraction gap had a tendency of decrease from 35.1-68.8% initially, to 49.1%, and finally to 17.6-27.2%. But at the final period, the tissue of the elongated gap still had the ability of cell proliferation. On the other hand, the expression of PCNA positive cells in the control side were negligible through the experimental period. 4. PCNA positive cells were observed primarily both at the central fibrous zone and at the region of just adjacent to CFZ which initiated new bone formation. 5. The expression pattern of the type I collagen was not zone-specific. They were observed diffusely throughout the elongation gap. 6. The predominant mechanism of new bone formation in the distraction gap was intramembranous. But, some of the regenerated bone was formed by endochondral ossification.

A Study on the Relationship between CEA Immunohistochemical Findings and Expression Rate of PCNA and Clinicopathologic Factors of Colorectal Cancers

Immunohistochemical study was performed for CEA staining patterns and PCNA indices. And the relationship between immunohistochemical findings and well-known clinical prognostic factors on the purpose of the clinical usefulness was evaluated. In forty seven cases of surgically removed colorectal carcinomas, the results were as follows; CEA staining patterns were apical (17 cases) and cytoplasmic (30 cases) type. Carcinomas with cyto plasmic pattern for CEA revealed more advanced Dukes' stage and more undifferentiated type and higher incidence of lymph node metastasis and were correlated with increased serum CEA levels. But PCNA indices showed no correlation with the Dukes' stage, histologic grade and CEA staining patterns. The cytoplasmic pattern of CEA immunohistochemistry may be a useful marker suggesting more aggressive biologic behavior of the colorectal carcinomas.

A Comparative Study of PCNA(Proliferating Cell Nuclear Antigen) and AgNORs(Argyrophilic Nucleolar Organizer Regions) in Malignancy of Brain Tumors

The authors studied the expression of proliferating cell nuclear antigen (PCNA) and the number of argyrophilic nucleolar organizer regions (AgNORs) in 94 cases of various brain tumors and in 5 cases of normal brains. PCN was recognized immunohistochemically in paraffin sections by the monoclonal antibody PC-10. AgNORs could be demonstrated using the silver impregnation method. The PCNA index was not significantly different from the histological grading of glioma(glioblastoma multiforme: 41.40+/-29.14%, anaplastic astrocytoma: 35.00+/-41.02%, and low grade astrocytoma: 22.37+/-30.85%) and there was a wide range of staining even in the same tissue section. However, the AgNORs count per cell correlated well with the pathologic grading of glioma (glioblastoma multiforme : 3.19+/-0.71, anaplastic astrocytoma : 2.06+/-0.16, and low grade astrocytoma : 1.27+/-0.29) with statistical significance. In meningiomas, AgNORs were useful to differentiate benign meningiomas(1.25+/-0.19) and malignant meningiomas(1.78+/-0.35) The authors suggest that the AgNORs count is a faster, less expensive, and a more predictive method in the malignancy of brain tumors than the PCNA immunochemistry expression.