Respiration gating radiotherapy technique developed in consideration of the movement of body surface and internal organs during respiration, is categorized into the method of analyzing the respiratory volume for data processing and that of keeping track of fiducial landmark or dermatologic markers based on radiography. However, since these methods require high-priced equipments for treatment and are used for the specific radiotherapy. Therefore, we should develop new essential method whilst ruling out the possible problems. This study aims to obtain body surface motion by using the couch based computer-controlled motion phantom (CBMP) and US sensor, and to develop respiration gating techniques that can adjust patients' beds by using opposite values of the data obtained. The CBMP made to measure body surface motion is composed of a BS II microprocessor, sensor, host computer and stepping motor etc. And the program to control and operate it was developed. After the CBMP was adjusted by entering random movement data, and the phantom movements were acquired using the sensors, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using a rabbit, the real-time respiration gating techniques were drawn by operating the phantom with the opposite values of the data. The result of analyzing the acquisition-correction delay time for the data value shows that the data value coincided within 1% and that the acquisition-correction delay time was obtained real-time (2.34 x 10(-4) sec). And the movement was the maximum movement was 6 mm in Z direction, in which the respiratory cycle was 2.9 seconds. This study successfully confirms the clinical application possibility of respiration gating techniques by using a CBMP and sensor.
Feasibility Studies* ; Microcomputers ; Radiography ; Radiotherapy ; Respiration ; Ultrasonics*

Low-abundance cellular proteins normally invisible on the standard two-dimensional SDS-polyacrylamide gel electrophoresis (2-DE SDS-PAGE) map must be enriched appropriately in order to be visualized and identified in cells or tissues. We applied proteins of H. pylori strain 26695 to a immobilized heparin-affinity resin, which has an affinity for nucleic acid-binding proteins, protein biosynthesis factors, and growth factors. The whole cell extract of H. pylori strain 26695 was fractionated by the heparin-agarose chromatography, and was analyzed by 2-DE. The 2-DE SDS-PAGE displayed spots after silver staining, which were identified by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Among the ca. 150 spots that were processed, 79 proteins representing 57 genes were identified. Eleven proteins were determined to be nucleic acid-associated. Eighteen proteins were newly identified in this study, including DNA topoisomerase I. These results may provide guidance for enriching low abundance proteins of H. pylori and contribute to the construction of a master protein map of H. pylori.
Chromatography* ; DNA Topoisomerases, Type I ; Electrophoresis ; Electrophoresis, Polyacrylamide Gel ; Helicobacter pylori* ; Helicobacter* ; Heparin* ; Intercellular Signaling Peptides and Proteins ; Mass Spectrometry ; Protein Biosynthesis ; Proteome ; Silver Staining

PURPOSE: The purpose of this study was to estimate the biomechanical effect of rotational acetabular osteotomy by analyzing the stress on the surface of the femoral head according to center-edge (CE) angle by computer simulation. MATERIALS AND METHODS: We performed computer simulation by simplifying the pelvis and femur to 3-dimensional flat stress. We analyzed the change of distribution of stress and the amount of deformation according to the degree of acetabular dysplasia, represented by the change of CE angle, by using a Finite element model (FEM). Stress and deformation were calculated in two cases that underwent rotational acetabular osteotomy. RESULTS: In the FEM model, the stress was 3.74 MPa at a CE angle of 30.and the deformation was 1.37 mm. The stress was 14 MPa at 15., 34.2 MPa at 0., and 82.4 MPa at -15. In a case of rotational acetabular osteotomy, the pre-operative and post-operative stresses were 26.1 MPa and 5.16 MPa, and the maximal deformations were 16.1 mm and 1.6 mm, respectively. CONCLUSION: As the severity of acetabular dysplasia increases, the stress concentration also increases. When the CE angle is below 0., a high concentration of stress develops. After rotational acetabular osteotomy, maximal stress was reduced to normal levels and sufficient stress distribution was achieved.
Acetabulum* ; Computer Simulation ; Femur ; Head ; Hip Dislocation ; Hip* ; Osteotomy* ; Pelvis

PURPOSE: Adenomatous polyps in the stomach are rather uncommon, however are related to a malignant transformation. So, in such cases it is important to predict cancer risk and to select an appropriate surgical method. The aim of this study is to examine clinicopathologic factor for predicting malignancy and determine appropriate surgical management of gastric adenomatous polyps. METHODS: A total 41 patients who underwent surgery from 1996 to 1999 for gastric adenomatous polyps at the Department of Surgery, Seoul National University Hospital were included this study. All patients had undergone preoperative endoscopic biopsy and histology was confirmed. Authors analyzed the clinicopathologic factors associated with malignancy and the outcome of surgical treatment. RESULTS: Of the 41 patients, 17 patients had an adenomatous polyp alone, 24 patients had an adenomatous polyp associated with malignancy. The location, number, size and morphology of the polyp were not associated with malignancy. Only cellular atypism in the preoperative biopsy was significantly associated with malignancy. 31 patients underwent subtotal gastrectomy whereas 10 patients wedge resection. All lymph nodes resected in patients with adenocarcinoma were negative. Recurrence of polyp or adenocarcinoma had not occurred in any patients after follow-up of mean 22 months. CONCLUSION: Cellular atypism detected in preoperative histology was associated with malignancy in gastric adenomatous polyp. Lymph node metastasis was negative in patients with malignancy. Our findings support the wedge resection withsafe margin as being appropriate in surgical management of gastric adenomatous polyps.
Adenocarcinoma ; Adenomatous Polyps* ; Biopsy ; Follow-Up Studies ; Gastrectomy ; Humans ; Lymph Nodes ; Neoplasm Metastasis ; Polyps ; Recurrence ; Seoul ; Stomach

PURPOSE: In the fifth edition of International Union Against Cancer (UICC) TNM, nodal staging for gastric cancer is based on the number of metastatic lymph nodes. Variability in the extent of lymphadenectomy and lymph node retrieval can affect the number of metastatic lymph nodes. In this study, the authors attempted to evaluate the influence of nodal yields on the staging of gastric cancer and survival rates. METHODS: A retrospective study was performed in 4354 consecutive patients with gastric cancer, who had undergone curative resection (R0) with nodal yields of 15 or more from 1986 to 1995. Patients were classified into three groups according to the number of nodes examined: patients with nodal yields of 15 or more but less than 30 for group A, 30-39 for group B, and 40 or more for group C. The number of metastatic lymph nodes and the survival rates for each pTNM stage were analyzed for each group. RESULTS: The number of metastatic lymph nodes significantly increased with nodal yields. Greater nodal yields resulted in a higher survival rates with a statistically significant difference between patients with nodal yields of 30 or more, and those with less than 30 in stage IB (p<0.05) and IIIB (p<0.01). CONCLUSION: Our results suggest two possibilities of stage migration and survival benefit according to the difference of nodal yields. Therefore, for minimizing stage migration and maximizing the benefit of survival, at least 30 or more lymphnodes should be resected and examined in gastric cancer surgery.
Humans ; Lymph Node Excision ; Lymph Nodes ; Retrospective Studies ; Stomach Neoplasms* ; Survival Rate

This study describes the purification and characterization of type II restriction endonuclease of Helicobacter pylori in order to understand the DNA restriction and modification of H. pylori. H. pylori cell extract was subjected to polyethyleneimine treatment, salt precipitation, heparine-sepharose column chromatography, and fast protein liquid chromatography (FPLC) using Resource Q column and Mono Q column to purify the type II restriction endonuclease. Hpy51-I was characterized to recognize the sequneces 5`-GT(G/C)AC-3`, yielding 5-base 5` protruding ends. The restriction sequence was identical to that of Tsp 45 I. The enzyme exhibited its maximal activity in the presence of 10-20 mM LaCl, but was inhibited completely in the presence of more than 80 mM NaCl. The enzyme showed its maximal activity in the presence of 1-10 mM MgC1(2). The optimal pH and temperature for enzyme activity was pH 9.0 and 37 degrees C, respectively. MnC1(2) could not substitute for MgC1(2) in reaction mixture. And addition of j3-mercaptoethanol and bovine serum albumin in reaction mixture led to loss of enzyme activity of Hpy51-I. The whole cell extract of H. pylori strain 51 was confirmed to carry the enzyme activity for methylation of Hpy51-I-recognised sequence. Hpy51-I digested genomic DNAs of enteric bacteria to less than I kb while it could not cut the genomic DNAs of H. pylori isolates. In this study, the type II restriction enzyme (Hpy51-I) of H. pylori was identified and characterized its biochemical properties, demonstrating that Hpy51-I might be one of the barriers for preventing the introduction of foreign DNAs into H. pylori.
Chromatography ; Chromatography, Liquid ; DNA ; DNA Restriction Enzymes* ; Enterobacteriaceae ; Helicobacter pylori* ; Helicobacter* ; Hydrogen-Ion Concentration ; Methylation ; Polyethyleneimine ; Serum Albumin, Bovine

PURPOSE: The prognostic significance of lymph node (LN) micrometastasis in gastric cancer remains contro versial. We therefore investigated the clinicopathologic factors related to LN micrometastasis and evaluated the clinical relevance of micrometastasis with regard to urrence. MATERIALS AND METHODS: A total of 1083 LNs from 39 patients with pT2N0 gastric cancer and who underwent curative resection in 1993 were further immunohistochemically stained using an anti-cytokeratin Ab cocktail (AE1-AE3). RESULTS: Micrometastases were found in 3.9% (42/1083) of the resected LNs and 53.8% (21/39) of the patients with pT2N0 gastric cancer. LN micrometastasis was found to be significantly related with histologic differentiation. The recurrence rate of gastric cancer was higher in patients with LN micrometastasis (31.6%) than in those without (6.3%), with a borderline significance (p=0.074). In uni variate analysis, patients with LN micrometastasis had a shorter 5-year disease-free survival (65%) than those without LN micrometastasis (87%) (p=0.075). In multivariate analysis, multiple LN micrometastasis was associated with a poor prognosis, but with a borderline significance (p=0.069, Risk ratio 4.815) CONCLUSION: We were able to identify LN micrometastases missed on routine H-E staining, using an immuno histochemical technique. Our results suggest that LN micrometastasis is associated with the recurrence of pT2N0 gastric cancer.
Disease-Free Survival ; Humans ; Lymph Nodes* ; Multivariate Analysis ; Neoplasm Micrometastasis* ; Odds Ratio ; Prognosis ; Recurrence ; Stomach Neoplasms*

PURPOSE: This study was designed to investigate the clinicopathologic factors related to peritoneal recurrence and to predict peritoneal recurrence based on clinicopathologic factors. METHODS: A retrospective analysis of 383 patients with peritoneal recurrence, out of 4184 patients who had undergone curative gastric resection at SNUH from 1986 through 1996 was done. RESULTS: Of the patients with peritoneal recurrence, 275 (71.8%), 97 (25.3%), and 11 (2.9%) were early (0~24 months), intermediate (24~60), and late (more than 60) recurrence, respectively. In multivariate analysis, serosal invasion, lymph node metastasis, size of tumor, Borrmann type, perineural invasion and sex were independent prognostic factors for peritoneal recurrence. After classifying all patients into 16 groups on the basis of 4 factors, serosal invasion, lymph node metastasis, Borrmann type, and size, the number and proportion of a patients with peritoneal recurrence was obtained. There was 4.2% peritoneal recurrence in the most favorable group (n = 71), which had a Borrmann type 1 or 2 lesion less than 5 cm in maximal diameter with neither serosal invasion nor lymph node metastasis. There was a 25.4% peritoneal recurrence in the most unfavorable group (n = 331), which had a Borrmann type 3 or 4 lesion more than 5 cm with serosal invasion and lymph node metastasis. CONCLUSION: Our results suggest that patients with a Borrmann 3 or 4 lesion more than 5cm in maximal diameter, with serosal invasion and lymph node metastasis have thehighest risk for peritoneal recurrence. These patients could be considered as candidates for a treatment modality such as intraperitoneal chemotherapy or hyperthermic chemotherapy.
Drug Therapy ; Humans ; Lymph Nodes ; Multivariate Analysis ; Neoplasm Metastasis ; Recurrence* ; Retrospective Studies ; Risk Factors ; Stomach Neoplasms*

PURPOSE: This study was designed to investigate the correlation between the clinicopathologic characteristics and the recurrence pattern of gastric cancer and to define survival difference according to treatment modality after diagnosis of recurrence. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 4184 patients who had undergone radical surgery for primary gastric cancer from 1986 through 1996. Clinicopathologic factors were analyzed for the relationship of each factor with the pattern of recurrence. And the survival after diagnosis of recurrence was compared among the treatment modalities. RESULTS: Recurrence pattern was confirmed in 1141 patients. Loco-regional recurrence occurred in 291 patients (20.1%), peritoneal recurrence in 383 (26.5%), distant recurrence in 290 (20.1%), and mixed recurrence in 177 (12.3%), respectively. Early recurrence (less than 2 years) occurred in 767 (69.3%), intermediate recurrence (2~5 years) in 286 (25.8%), and late recurrence (more than 5 years) in 54 (4.9%). In multivariate analysis, T stage, N stage, size of tumor and perineural invasion were independent prognostic factors for recurrence. Median survival from diagnosis of recurrence was 24.2 months in the curative operation group, 7.7 months in the chemotherapy group, 7.1 months in the non-curative operation group and 3.3 months in the conservative treatment group, respectively (p=0.000). CONCLUSION: The clinicopathological analysis of recurrent gastric cancer showed recurrent patterns and prognostic factors. Curative resection is suggested to have survival benefit in recurrent gastric cancer patients, although it was possible in patients with limited extent of disease.
Diagnosis ; Drug Therapy ; Humans ; Medical Records ; Multivariate Analysis ; Recurrence ; Retrospective Studies ; Stomach Neoplasms*

PURPOSE: The majority of patients with early gastric cancer show long-term survival after surgery. So a special attention must be directed to preserving gastric function in these patients. When node-negative early gastric cancer could be diagnosed preoperatively, then minimally invasive surgery can be performed to ensure a postoperative better quality of life. MATERIALS AND METHODS: The pathological records of 2,137 consecutive patients with early gastric cancer who underwent curative operations from January 1986 to December 1998 at Seoul National University Hospital were reviewed. RESULTS: Lymph node metastases were observed in 285 patients (13.3%). In mucosal carcinoma, lymph node metastases were observed in 50 of 1,108 cases (4.5%), and in submucosal carcinoma, in 234 of 1,026 cases (22.8%). The tumor size, depth of invasion and gross appearance were associated with lymph node metastasis. In mucosal carcinoma, the size and histologic differ entiation were associated with lymph node metastasis. In submucosal carcinoma, the size and gross appearance were associated with lymph node metastasis. CONCLUSION: In early gastric cancer, the limited surgery can be applied only to cases satisfying the following criteria; (1) mucosal tumor, (2) size < or =2 cm, (3) elevated type or (4) depressed type which are histologically differentiated and (5) size < or =1 cm among the depressed type his tologically undifferentiated.
Humans ; Lymph Nodes* ; Neoplasm Metastasis* ; Quality of Life ; Seoul ; Stomach Neoplasms* ; Surgical Procedures, Minimally Invasive