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T Yao

Publications and source records attributed to T Yao.

At least 73 records · Page 4Linked to original sources
PubMed2000

A high-resolution millennial record of the south asian monsoon from himalayan ice cores

A high-resolution ice core record from Dasuopu, Tibet, reveals that this site is sensitive to fluctuations in the intensity of the South Asian Monsoon. Reductions in monsoonal intensity are recorded by dust and chloride concentrations. The deeper, older sections of the Dasuopu cores suggest many other periods of drought in this region, but none have been of greater intensity than the greatest recorded drought, during 1790 to 1796 A.D. of the last millennium. The 20th century increase in anthropogenic activity in India and Nepal, upwind from this site, is recorded by a doubling of chloride concentrations and a fourfold increase in dust. Like other ice cores from the Tibetan Plateau, Dasuopu suggests a large-scale, plateau-wide 20th-century warming trend that appears to be amplified at higher elevations.

Journal Article↗
PubMed2000

A clinicopathologic study of primary small intestine lymphoma: prognostic significance of mucosa-associated lymphoid tissue-derived lymphoma.

BACKGROUND: It remains unclear whether the presence of mucosa-associated lymphoid tissue (MALT) lymphoma has prognostic implications for patients with primary small intestine lymphoma. METHODS: The clinicopathologic features of 80 patients with primary small intestine lymphoma were examined retrospectively in relation to the presence of MALT lymphoma. Survival was compared univariately and multivariately among the groups divided by clinicopathologic findings. RESULTS: Twenty-one cases (26%) were diagnosed as low grade B-cell lymphoma (15 marginal zone B-cell lymphoma of MALT type, 2 mantle cell lymphoma, and 4 follicle center lymphoma), 46 cases (58%) were diagnosed as high grade B-cell lymphoma (19 secondary large cell lymphoma with a low grade MALT component, 17 diffuse large cell lymphoma without MALT features, 7 Burkitt lymphoma, and 3 lymphoblastic lymphoma), and 13 cases (16%) were diagnosed as T-cell lymphoma. A significantly better survival was noted for patients without colorectal and/or gastric involvement, diffuse infiltration under macroscopy, high grade histology, and perforation. Those patients with MALT type tumors, less advanced stage of disease, B-cell phenotype, benign lymphoid follicular hyperplasia, and radical tumor resectability appeared to have a better survival rate. Based on Cox multivariate analysis, early stage disease and MALT-derived tumors were determined to be independent prognostic factors (P < 0.05). CONCLUSIONS: The presence of MALT-derived lymphoma appears to have a favorable prognosis among patients with primary small intestinal lymphoma.

Adolescent↗
PubMed2000

Multiple 'serrated adenocarcinomas' of the colon with a cell lineage common to metaplastic polyp and serrated adenoma. Case report of a new subtype of colonic adenocarcinoma with gastric differentiation.

A 70-year-old woman underwent right hemicolectomy and six carcinomas were recognized in the resected colon. These carcinomas were considered to be of a cell lineage common to serrated adenoma (SA) and hyperplastic (metaplastic) polyp (H/MP), because of the occurrence of multiple SAs and H/MPs around the carcinomas, as well as the co-existence of SA and H/MP areas within the carcinomas. These carcinomas had the following common histological and immunohistochemical features: a serrated structure resembling SA; a lace-like structure; infiltrative growth within the muscularis propria, with dedifferentiation at the invasive front; and immunohistochemical expression of pS2 and human gastric mucin. Based on these features, a new subtype of carcinoma is proposed, with a cell lineage common to SA and H/MP. It would also seem that p53 is involved in the serrated adenoma-carcinoma sequence.

Adenocarcinoma↗
PubMed2000

Natural history of early colorectal cancer: evolution of a growth curve.

PURPOSE: There are very few studies on the development of early colorectal cancers, although we have previously reported growth speeds of early colorectal cancer in a radiographic retrospective study. The aim of this study was to estimate a statistical curve for cancer growth from mucosal cancer. METHODS: Subjects of the study were 31 patients with cancer in which initial lesions were diagnosed as mucosal cancer. These lesions were overlooked in the first or second investigations, but were detected later. Initial radiographic features were as follows; 4 pedunculated lesions, 1 semipedunculated lesion, 6 sessile lesions, 9 superficially elevated lesions, and 11 superficially depressed lesions. The diameters of the initial lesions were 12.1+/-6.1 mm. The final depths of invasion were 6 mucosal cancers, 12 submucosal cancers, 6 muscularis propria cancers, and 7 serosal cancers. The observation period between the initial and final examination was 41.5+/-25.8 months. The growth curve was estimated by an exponential curve with the natural logarithm of d = e (a + b x t), where a is the intercept (initial tumor size) and b is the regression coefficient (growth speed). RESULTS: A growth curve was obtained as follows: diameter = 12.5 x 2(t/77) (r = 0.448, P < 0.0001) and 95 percent confidence interval of time = 53 to 173 months. Subsequently, volume = 1 x 10(3) x 2(t/26), and the 95 percent confidence interval of time = 18 to 58 months. CONCLUSION: Growth speed of early colorectal cancer was estimated through a statistically significant growth curve. Estimated doubling time of the volume of early colorectal cancer was 26 (95 percent confidence interval, 18-58) months. From these results we could obtain a rational cancer surveillance program using appropriate procedures with different sensitivities.

Aged↗
PubMed2000

Crohn's disease in Japan: diagnostic criteria and epidemiology.

New diagnostic criteria for Crohn's disease and a review of Japanese epidemiologic studies are presented. New diagnostic criteria for Crohn's disease were established by the Research Committee of Inflammatory Bowel Disease, set up by the Japanese Ministry of Health and Welfare. For a definite diagnosis one of the following three conditions is required: 1) longitudinal ulcer or luminal deformity induced by longitudinal ulcer or cobblestone pattern, 2) intestinal small aphthous ulcerations arranged in a longitudinal fashion for at least three months plus noncaseating granulomas, and 3) multiple small aphthous ulcerations in both the upper and lower digestive tract not necessarily with longitudinal arrangement, for at least three months, plus noncaseating granulomas. Moreover, ulcerative colitis, ischemic enterocolitis, and acute infectious enterocolitis should be excluded. Data from the Japanese Ministry of Health and Welfare, in addition to data collected from two study groups, these being the two largest studies in Japan, are reviewed with regard to epidemiology. The number of patients with Crohn's disease has increased remarkably. The prevalence and the annual incidence of patients with Crohn's disease in Japan were estimated to be approximately 2.9 and 0.6 per 10(5) population in 1986, respectively, and 13.5 and 1.2 per 10(5) population in 1998. Characteristic features of Crohn's disease in Japan are that the male-female ratio exceeds 2, and that there is no second peak of incidence in the age group of 55 to 65 years. Clinically, Crohn's disease with only multiple small aphthous ulcerations, which is the earliest stage of the disease that is diagnosable, was found in 5 percent of patients.

Adolescent↗
PubMed2000

Invasive colon cancer derived from a small superficial depressed cancer: report of a case.

A 64-year-old male in May 1997 was diagnosed by colonoscopy and a barium enema examination as having an invasive cancer in the transverse colon. Pathologic study of the resected surgical specimen revealed a well-differentiated adenocarcinoma invading the muscularis propria. He had a colonoscopic examination in 1991 and was diagnosed as having multiple adenomas, which were endoscopically removed. After that he had annual colonoscopy or barium enema examination follow-ups. At endoscopy in February 1994, a superficial depressed cancer 6 mm in diameter had been detected. However, the cancer was not seen again in several endoscopic examinations until one in 1997. Because the location of the lesion detected in 1994 and that of the invasive carcinoma detected in 1997 were identical, it was considered that the superficial depressed cancer developed, 40 months later, to an advanced cancer. Doubling time was calculated as 8.4 months.

Adenocarcinoma↗
PubMed2000

Natural history of early colorectal cancer.

Since superficial tumors have been found, their peculiar pathologic features have evoked questions concerning their biologic behavior, their natural history. The aim of the present study was to elucidate the natural history of colorectal cancers (CRCs) including superficial cancers, using a retrospective radiologic method. Forty nine cancers that had had initial configurations of early cancer seen by previous radiography and that were examined pathologically were the subject of the present study. Growth speeds [doubling time (DT) calculation] and configurational changes at the various stages (invasion depth) were compared between polypoid growth (PG) and nonpolypoid growth (NPG). Growth speeds of mucosal cancer and submucosal cancer were also compared. The results showed that early CRC grows slowly (DT 31.2 months) when the cancer is limited to the mucosa. However, as tumors grow down to the submucosa, their growth speed accelerates (DT 25.8 months). The DT of these early cancers were longer than that of advanced cancers. The pathologic growth pattern (NPG or PG) of the CRCs did not affect the tumor growth speed. In respect to tumor configuration, when the tumor is limited to the submucosa the antecedent growth pattern may be easily deduced. It seems difficult, however, to know the initial growth patterns in advanced cancers because cancers with polyloid growth frequently change to a nonpolypoid growth pattern when in advanced stages. Among 32 advanced cancers, only 6 (19%) derived from IIc/IIc + IIa cancer. The most common (more than 70%) origin of advanced cancer seems to be IIa, Is, and Isp lesions. These results suggest that NPG cancers or superficial depressed cancers are not the main origins of advanced cancers, and that these cancer do not show extraordinarily rapid growth.

Colonic Polyps↗
PubMed2000

Peptic ulcer recurrence during maintenance therapy with H2-receptor antagonist following first-line therapy with proton pump inhibitor.

We investigated the peptic ulcer recurrence rates during maintenance therapy with H2-receptor antagonists (H2RAs) following first-line therapy with a proton pump inhibitor (PPI). Patients with gastric ulcer (GU) or duodenal ulcer (DU) were enrolled in this study; 583 eligible patients (GU, 325; DU, 258) were administered lansoprazole (30 mg/day for 8 weeks for GU, and the same dosage for 6 weeks for DU) as first-line therapy, and a half dose of H2RA as maintenance therapy for 12 months. Endoscopic photographs were taken before administration and after 8 (GU) and 6 (DU) weeks of lansoprazole administration. Ulcer stage was evaluated using the classification of Sakita and Miwa. Endoscopic examinations were performed 6 months or 12 months after the start of maintenance therapy or when a recurrence was suspected because of the appearance of subjective symptoms. The healing rates for GU and DU patients after completion of lansoprazole therapy were 79% in both groups, while the S2-stage healing rates were 18% and 31%, respectively. At 1 year after the start of maintenance therapy, the recurrence rates were 25% for GU and 39% for DU patients. In DU patients, the recurrence rates from S1-stage and S2-stage were 49% and 20%, respectively (P = 0.004), but no significant difference was found between these rates in GU patients. The recurrence rates in H. pylori-positive patients before lansoprazole administration were 27% for GU and 43% for DU patients. We concluded that the maintenance therapy with a half-dose of H2RA following PPI therapy was insufficient to prevent recurrences of GU and DU.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Adenosquamous carcinoma of the remnant stomach: report of a case.

We report herein the case of a 59-year-old man found to have adenosquamous carcinoma of the remnant stomach which demonstrated rapid progression. The patient was admitted to our hospital to undergo surgery for a papillary tumor of the remnant stomach. Total resection of the remnant stomach with lymph node dissection was performed, and pathological examination confirmed a diagnosis of adenosquamous carcinoma with invasion into the muscularis propria and lymph node metastasis around the perigastric areas. Multiple liver metastases were found 6 months after the operation, for which a right hepatectomy was performed with curative intent; however, he died 2 months later due to lymphangitis carcinomatosa of the lung.

Carcinoma, Adenosquamous↗
PubMed2000

Expressions of cell-cycle regulatory gene products in conventional gastric adenomas: possible immunohistochemical markers of malignant transformation.

In 54 lesions of gastric adenomas consisting of 31 low-grade adenomas (LGAs) and 23 high-grade adenomas (HGAs), 28 intramucosal carcinomas (IMCs), and 23 carcinomas invading the submucosa (SMCs), the expression of cell-cycle regulatory gene products (p53, p21/waf1, p27/kip1, and Ki-67) was studied using immunohistochemical techniques. Several lesions were also analyzed by the fluorescence in situ hybridization method. The overexpression of p53 was found in no LGAs and in 9% of HGAs, whereas a considerable number of cases showed an overexpression in IMCs (39%) and SMCs (43%). A reduced expression of p21/waf1 was present in only 4% of HGAs. Superficial eccentric positivity was present in all LGAs and 74% of HGAs, whereas it was present in 46% of IMCs and 4% of SMCs. P53-positive and p21/waf1-negative lesions, which were supposed to have a mutated p53 gene, were observed in no LGAs, in 4% of HGAs, in 11% of IMCs, and in 26% of SMCs. The expression of cyclin E was more frequently present in carcinomas than in adenomas. However, no high expression of cyclin E was observed among the adenomas. A reduced expression of p27/kip1 was encountered more frequently in carcinoma than adenoma. By a semiquantitative evaluation comparing adenoma and carcinoma in the same stomach, the increased degrees of both p21/waf1 and cyclin E were highlighted. A chromosome gain was detected among 7% of the adenomas and 85% of the carcinomas. In conclusion, the expressions of p53, p21/waf1, p27/kip1, and cyclin E were considered to be of great value for estimating the dysplastic progression of gastric adenomas. Especially, various aspects of protein expression, including its distribution and semiquantitative evaluation of positive cells, and a combined analysis with several proteins, may thus be useful as possible markers of dysplastic evolution in gastric adenomas.

Adenocarcinoma↗
PubMed2000

Composition and structure of apatite formed on organic polymer in simulated body fluid with a high content of carbonate ion.

Apatite layer was formed on polyethyleneterephthalate (PET) substrate by the following biomimetic process. The PET substrate was placed on granular particles of a CaO, SiO2-based glass in simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma to form apatite nuclei on their surfaces. The apatite nuclei was then grown into a continuous layer by subsequently soaking the substrate in SBF under air or CO2 atmosphere in which CO2 partial pressure in the ambient was adjusted to 14.8 kPa to increase the content of carbonate ion to a level nearly equal to that of blood plasma. The increase in the content of carbonate ions in SBF changed the Ca/P atomic ratio of the apatite from 1.51 to 1.63, content of CO(3)2- ions from 2.64 to 4.56 wt %, and lattice constants a from 94.32 to 94.23 nm and c from 68.70 to 68.83 nm, respectively. The Ca/P ratio and lattice constants of the apatite formed in SBF under CO2 atmosphere were approximately identical to those of bone apatite, i.e. Ca/P atomic ratio 1.65, content of CO(3)2- ion 5.80 wt % and lattice constants a 94.20 and c 68.80 nm. This indicates that an apatite with composition and structure nearly identical to those of bone apatite can be produced in SBF by adjusting its ion concentrations including the content of carbonate ions to be equal to those of blood plasma.

Journal Article↗
PubMed2000

Discordance of p53 mutations of synchronous colorectal carcinomas.

It is unclear whether synchronous multiple tumors arise from multicentric or monoclonal origins. To verify the multicentric origin of synchronous colorectal carcinomas at a genetic level, immunohistochemical and molecular techniques were used to determine the p53 alterations in individual lesions of synchronous colorectal carcinomas. This study was based on a total of 32 colorectal tumors from 16 patients. Twenty-one of the 32 (66%) advanced tumors examined had positive staining for p53. Single-strand conformation polymorphism and polymerase chain reaction direct sequencing were carried out for exons 5 to 8 of p53. All cases had p53 mutations in one or more tumors of synchronous lesions. In nine patients in this series, individual lesions were found to carry a different mutated codon of the p53 gene. In the other seven patients, a p53 mutation was found in one tumor but not in another. These results indicate discordance of the mutation pattern of p53 in individual lesions of multiple colorectal carcinomas and support the idea that most synchronous colorectal carcinomas are genetically distinguishable and are multicentric in origin. We also confirmed the high frequency of p53 mutations in left-sided (71%) and rectal (91%) carcinomas, rather than right-sided (43%; P = .04) carcinomas, suggesting that the molecular mechanism of synchronous colorectal carcinomas might differ between right- and left-sided tumors in the same patient.

Adenocarcinoma↗
PubMed2000

Carcinoma of the ampulla of Vater associated with or without adenoma: a clinicopathologic analysis of 198 cases with reference to p53 and Ki-67 immunohistochemical expressions.

Adenomatous areas are found frequently within or in the vicinity of carcinoma of the ampulla of Vater. This makes definite diagnosis difficult in the preoperative examination. The adenoma-carcinoma development hypothesis is generally accepted for colorectal tumors. Recently, a genetic alteration model during colorectal tumor development has attracted much attention, leading to various studies. We studied clinicopathologic features, prognostic factors, and the alteration of the p53 tumor suppressor gene using p53 immunohistochemical staining in pure adenomas, pure carcinomas, and carcinomas with adenomatous areas. A proliferative activity of the tumors using Ki-67 was also evaluated. Nine cases of pure adenoma and 198 cases of carcinoma of the ampulla of Vater were selected for this study. Among the 198 cases of thecarcinoma, 83 cases (42%) had adenomatous areas. Positivity of p53 immunohistochemical staining was 0% in pure adenomas, 36% in the adenomatous areas of carcinomas with adenomatous areas and 62% in the carcinomatous areas of carcinomas with adenomatous areas, and 56% in pure carcinoma. Accumulation of p53 protein and the Ki-67 labeling index revealed no significant difference in prognosis. The clinicopathological factors examined were as follows: degree of invasion of the surrounding tissue, such as duodenal wall; pancreatic parenchyma; the presence or absence of lymphatic permeation; venous invasion; perineural invasion; the presence of regional lymph node metastasis; and TNM stage. Each of the clinicopathological factors showed a significant difference. Multivariate analysis revealed strong predictors for a worse prognosis: presence of lymphatic permeation, invasion of the pancreas, and perineural invasion. In conclusion, our results are consistent with the adenoma--carcinoma development hypothesis. It would seem that the molecular events leading to p53 accumulation in neoplasms of the ampulla of Vater occur relatively late during the oncogenetic process. Moreover, we think it may be useful to refer to the p53 overexpression in the diagnosis of ampullary tumors.

Adenoma↗
PubMed2000

Gastric or intestinal phenotypic expression in the carcinomas and background mucosa of multiple early gastric carcinomas.

AIMS: The differences in phenotypic expression between multiple early gastric carcinomas (EGCs) and solitary EGCs were evaluated in this study. METHODS AND RESULTS: Fifty-three cases (53 lesions) of solitary EGCs and 50 cases (112 lesions) of multiple EGCs were studied. According to the classification of intestinal metaplasia, the phenotypes of carcinomas and background mucosa were classified into four categories-complete intestinal type, incomplete intestinal type, gastric type and unclassified type-based on the combination of expression of CD10 (small intestinal brush border), MUC2 (intestinal goblet cell), HGM (gastric foveolar epithelium) and Con A (gastric pyloric glands). The incidence of gastric-type carcinomas (48%) and the incidence of incomplete intestinal-type background mucosa (75%) among the multiple EGCs was higher than among the solitary EGCs. There was a significant difference in distribution of phenotypic expression of carcinomas and background mucosa between the solitary EGCs and the multiple EGCs, the latter being associated with incomplete intestinal metaplasia. CONCLUSIONS: Both the carcinomas and the background mucosa of multiple EGCs have an unstable status, since they more commonly possess the hybrid phenotype of the stomach and the small intestine than does solitary EGC. Such instability is considered to contribute to a high neoplastic potential and the multiple occurrence of carcinomas.

Adenocarcinoma↗
PubMed2000

Endoscopic ultrasound features of protein-losing gastropathy with hypertrophic gastric folds.

BACKGROUND AND STUDY AIMS: We aim to clarify the endoscopic ultrasound (EUS) features of protein-losing gastropathy with hypertrophic gastric folds (PLGH), including Ménétrier's disease. PATIENTS AND METHODS: We analyzed the EUS and histologic findings in five patients who underwent both endoscopic ultrasonography and endoscopic resection. RESULTS: Histologically, we diagnosed one patient as having acute gastritis, three patients as having Ménétrier's disease, and the remaining patient as having hypertrophic lymphocytic gastritis (HLG). Helicobacter pylori was recognized in all but one patient. At EUS every patient was found to have giant gastric folds (13 to 20 mm in diameter), resulting from echogenic thickening of the mucosal layer with or without cystic components. Two patients who underwent eradication therapy of H. pylori showed both clinical and morphologic resolution. CONCLUSIONS: Echogenic thickening of the mucosal layer may be a characteristic EUS feature of protein-losing gastropathy with hypertrophic gastric folds, and H. pylori may be one of the causative agents.

Adolescent↗
PubMed2000

Hemoglobin content in intramucosal gastric carcinoma as a marker of histologic differentiation: a clinical application of quantitative electronic endoscopy.

BACKGROUND: It has been suggested that the endoscopic color of intramucosal gastric carcinoma is correlated with mucosal vascularity within the carcinomatous tissue. The development of electronic endoscopy has made it possible to quantitatively measure the mucosal hemoglobin volume, using a hemoglobin index. The aims of the present study were to investigate whether this hemoglobin index is useful for evaluating the change in color of early gastric carcinoma and to verify the diagnostic value of this index for distinguishing between histologic degrees of differentiation. METHODS: The ratios of the hemoglobin index of cancerous and non-cancerous mucosa for 26 differentiated and 18 undifferentiated intramucosal gastric carcinomas were determined from electronic endoscopic imaging data. RESULTS: The mean ratio of the hemoglobin index of cancerous and non-cancerous mucosa in the differentiated gastric carcinomas was higher than it was in the undifferentiated carcinomas (1.23: 95% CI [1.15, 1.31] versus 0.84: 95% CI [0.81, 0. 88]). The sensitivity and specificity for discriminating undifferentiated from differentiated carcinoma were 100% and 85%, respectively. CONCLUSION: Measurement of mucosal hemoglobin volume (hemoglobin index) is useful for evaluating the endoscopic color of early gastric carcinoma quantitatively and may be helpful in distinguishing differentiated from undifferentiated carcinoma.

Adult↗