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T Yao

Publications and source records attributed to T Yao.

At least 91 records · Page 5Linked to original sources
PubMed2000

Natural history of ampullary adenoma in familial adenomatous polyposis: reconfirmation of benign nature during extended surveillance.

OBJECTIVE: Surgical or endoscopic papillectomy may be one of the therapeutic strategies for patients with familial adenomatous polyposis (FAP). To determine whether prophylactic papillectomy is necessary for FAP, we investigated the natural history of the ampullary adenoma in FAP. METHODS: Eighteen subjects with FAP were surveyed by duodenoscopy with biopsy for >10 yr. Endoscopic appearance, histological findings, and immunohistochemical stainings for Ki-67 of ampulla were compared between initial and final endoscopic examinations. RESULTS: The endoscopic grade in the ampulla remained unchanged in 16 subjects, whereas in two subjects an increase in the endoscopic grade was noted. In two subjects adenoma developed from an endoscopically and histologically normal ampulla. The histological grade of dysplasia increased in three of 12 subjects who initially had adenoma. The labeling index for Ki-67 was not different between initial and final examinations. CONCLUSIONS: These data suggest that most ampullary adenoma of patients with FAP is static and that aggressive endoscopic or surgical removal is unnecessary for the adenoma.

Adenoma↗
PubMed2000

Microaggregate of immunostained macrophages in noninflamed gastroduodenal mucosa: a new useful histological marker for differentiating Crohn's colitis from ulcerative colitis.

OBJECTIVE: In 10% of cases it may be difficult to differentiate Crohn's colitis from ulcerative colitis. Distinguishing the two conditions is important because they are distinct entities with different therapeutic implications. Noncaseating granulomas are usually considered diagnostic of Crohn's disease. We previously reported that the presence of a microaggregate of immunostained macrophages within the noninflamed gastroduodenal mucosa was a characteristic finding of Crohn's disease. The aim of this study was to determine whether a microaggregate of immunostained macrophages can be a reliable marker for differentiating Crohn's colitis from ulcerative colitis. METHODS: We investigated the presence of microaggregates of immunostained macrophages and epithelioid cell granulomas in biopsy specimens taken from the noninflamed gastroduodenal mucosa of 22 known Crohn's colitis patients and 23 established ulcerative colitis patients. The incidence of microaggregates and granulomas was compared between these two groups. RESULTS: Microaggregates and granulomas were detected only in the Crohn's colitis patients. In addition, the presence of microaggregates was more frequent than that of granulomas in Crohn's colitis patients (54.5% and 18.2%, respectively, 95% confidence interval for the difference: 10.0-62.7%). CONCLUSION: Detecting a microaggregate of immunostained macrophages in a biopsy specimen taken from noninflamed gastroduodenal mucosa seems to be a useful method for differentiating Crohn's colitis from ulcerative colitis.

Adolescent↗
PubMed2000

Phlebosclerotic colitis: value of radiography in diagnosis--report of three cases.

Three cases sharing the following radiologic features are reported: (a) abdominal conventional radiography-vascular calcifications at the right hemicolon, (b) abdominal computed tomography-colonic wall thickening and venous calcifications, and (c) barium enema examination-luminal narrowing of the right hemicolon and thumbprinting. There were no clinical or laboratory findings suggestive of portal hypertension. The disease entity, "phlebosclerotic colitis," should be differentiated from ordinary ischemic colitis.

Abdomen, Acute↗
PubMed2000

Crohn's disease of aphthous type: serial changes in intestinal lesions.

In Crohn's disease (CD), aphthous lesions are regarded as possible precursors of typical intestinal involvement. To determine the natural course of intestinal lesions in CD of aphthous type, the clinical course of 10 patients was retrospectively investigated during a period ranging from 6 to 16 years after diagnosis. The criterion for inclusion was confirmed aphthous lesions within the gastrointestinal tract with histologically verified epithelioid granuloma. The degrees of aphthous lesions in the small intestine and the colon were graded by small bowel radiography, barium enema examination and colonoscopy. Five patients developed typical CD during a period ranging from 0.8-3.3 years. The site of involvement was the ileum in three patients, the colon in one patient and both the ileum and the colon in one patient. Typical small intestinal CD occurred in four of seven patients with marked aphthous lesions of the small intestine, whereas colonic CD occurred in two of eight patients with such aphthous lesions of the colon. These findings suggest that CD of aphthous type is not necessarily a precursor of clinically overt disease. This may especially be the case for colonic aphthous lesions.

Adolescent↗
PubMed2000

Rheumatoid arthritis accompanied by colonic lesions.

A 69-year-old woman with a 6-year history of rheumatoid arthritis treated solely with an orally administered NSAID had slowly progressing persistent mild abdominal pain and diarrhea, accompanied with marked sing of inflammation as well as hypoproteinemia due to protein-losing gastroenteropathy. Examinations of the large intestine revealed variously shaped ulcerative lesions, centered around the left hemicolon, as well as luminal narrowing. The course of the disease and the shape of the lesions strongly suggested involvement of rheumatoid vasculitis; oral administration of prednisolone was effective.

Aged↗
PubMed2000

Effects of losartan on haemodynamic parameters and angiotensin receptor mRNA levels in rat heart after myocardial infarction.

We investigated the haemodynamic parameters and the regulation of cardiac mRNA levels of the angiotensin receptor subtypes, AT1 and AT2, by the AT,-receptor antagonist losartan in rat heart during the acute phase of myocardial infarction. AT1- andAT2-receptor mRNA levels markedly increased at 30 minutes and peaked at 24 hours post myocardial infarction (12.6-fold increase for AT1- and 17.2-fold increase for AT2 compared with controls). Losartan significantly reduced mean blood pressure in sham-operated rats and decreased mean blood pressure and left ventricular end-diastolic pressure in myocardial infarction rats. However, the AT,- andAT2-receptor mRNA levels of losartan-treated rats showed a pattern similar to that of water-treated rats. The time-dependent increase of AT1- and AT2-receptor mRNA levels is associated with the early remodelling process of non-infarcted myocardium post MI and is independent of AT1-receptor blockade.

Angiotensin Receptor Antagonists↗
PubMed2000

Chronic intestinal pseudo-obstruction due to dialysis-related amyloid deposition in the propria muscularis in a hemodialysis patient.

Dialysis-related amyloidosis (DRA) is one of the most serious complications interfering with rehabilitation in dialysis patients. Here, we report a case of beta2-microglobulin (beta2M)-related amyloidosis, in which the patient developed a severe intestinal pseudo-obstruction. The patient was a 42-year-old male who had been undergoing hemodialysis for 13 years, and who had no history of osteoarticular involvement of DRA. The first symptoms of the disease were severe abdominal fullness and nausea after meals. The whole intestinal wall biopsy revealed massive amyloid deposition in the propria muscularis. The patient became malnourished and died of acute subendocardial infarction 3 years after the onset. An autopsical examination revealed a massive deposition of amyloid, which was positively stained with anti-beta2M antibody but not AA amyloid, predominantly in the gastrointestinal muscular layer, including the tongue, esophagus, stomach, small intestines, colon, and rectum. These results suggest that the gastrointestinal involvement of beta2M-related amyloidosis might occur during the course of hemodialysis treatment, and that this possibility should be considered if patients suffer from intestinal pseudo-obstruction without osteoarticular symptoms.

Adult↗
PubMed2000

[Angiotensin II participates in stress-induced high blood pressure via stimulating hypothalamic vasopressin synthesis and release].

Experiments were carried out in male Sprague-Dawley rats. The animals were randomly divided into three groups: control, stressed and stress + captopril. Stress stimulations were composed of repeated electric foot-shock combined with noise, twice one day (2 h each session) for 15 consecutive days. Animals in the stress+captopril group were administered with captopril (50 mg/kg.d) intraperitoneally. The results showed that at the end of the 15-day experiment the systolic pressure of the tail artery in stressed rats was significantly higher than that of the control rats, i.e., 19.75+/ C1.0 kPa (n=8, P<0.05) versus 16.32+/ C0.55 kPa (n=7); the vasopressin (AVP) mRNA level in the hypothalamus of the stressed rats also increased significantly compared with that of the control rats, i.e., 12990.33+/ C1533.58 (n=6, P<0.001) versus 7332.66+/ C522.65 (n=6). However, in the stress + captopril rats, both the tail artery systolic pressure and hypothalamic AVP mRNA level were significantly higher than those of the control rats, but lower than those of the stressed rats. In the control rats, no significant change in mean blood pressure (MBP) was observed after intracerebroventricular (icv) injection of 0.3 microgram of d(CH(2))(5)Tyr(Me)AVP, a selective AVP V(1) receptor antagonist; however, a decrease in MBP was observed in both stressed and stress+captopril rats (P<0.05), but the decrease in stress+captopril rats was more obvious than that of the stressed rats after icv a same dose of d(CH(2))(5)Tyr(Me)AVP. These results indicate that the endogenous renin-angiotensin system participates in the mechanism of the stress-induced high blood pressure in rats, and that the effect of Ang II is mediated mainly by stimulating hypothalamic AVP synthesis and release, which in turn result in an increase in blood pressure by acting on the central V (1) receptors.

Angiotensin II↗
PubMed1999

Suppression of T and B lymphocyte activation by a Yersinia pseudotuberculosis virulence factor, yopH.

The acquired immune responses are crucial to the survival of Yersinia-infected animals. Mice lacking T cells are sensitive to Yersinia infection, and a humoral response to Yersinia can be protective. Diverse mechanisms for Yersinia to impair and evade the host innate immune defense have been suggested, but the effects of Yersinia on lymphocytes are not known. Here, we demonstrate that after a transient exposure to Y. pseudotuberculosis, T and B cells are impaired in their ability to be activated through their antigen receptors. T cells are inhibited in their ability to produce cytokines, and B cells are unable to upregulate surface expression of the costimulatory molecule, B7.2, in response to antigenic stimulation. The block of lymphocyte activation results from the inhibition of early phosphorylation events of the antigen receptor signaling complex. Through the use of Y. pseudotuberculosis mutants, we show that the inhibitory effect in both T cells and B cells is dependent on the production of Yersinia outermembrane protein (Yop) H, a tyrosine phosphatase. Our results suggest a mechanism by which the pathogenic bacteria may modulate a wide range of T and B cell-mediated immune responses.

Animals↗
PubMed1999

Depressed adenoma of the duodenum in patients with familial adenomatous polyposis: endoscopic and immunohistochemical features.

BACKGROUND: Depressed neoplastic lesions of the colorectum have been specified in patients with familial adenomatous polyposis (FAP). The aim of this study was to characterize endoscopic, histologic, and immunohistochemical features of depressed adenoma of the duodenum in patients with FAP. METHODS: Duodenoscopy was performed on 25 patients with FAP, and the neoplastic nonampullary lesions were classified as polypoid or depressed adenomas. The grade of dysplasia, the proliferative activity determined by Ki-67 labeling index (LI), and the grade of p53 expression were compared between polypoid and depressed neoplasia. RESULTS: Ten subjects had depressed nonampullary adenoma, whereas polypoid adenoma was found in the remaining 15 subjects. Moderate dysplasia was more frequent in depressed adenoma than in polypoid adenoma (70% vs. 27%, P = 0.04). Whereas p53 expression was not different between the two adenoma groups, the LI was significantly higher in depressed adenoma than in polypoid adenoma (59.7 +/- 9.5 vs. 47.5 +/- 10.7, P < 0.01). CONCLUSIONS: Depressed adenoma of the duodenum is a distinctive phenotype of duodenal neoplasm in patients with FAP. The high proliferative activity of depressed adenoma suggests that there may be a need to survey FAP patients with such lesions intensively.

Adenoma↗
PubMed1999

Minute gastric carcinoma of differentiated type with special reference to the significance of intestinal metaplasia, proliferative zone, and p53 protein during tumor development.

BACKGROUND: The differentiated type of minute gastric carcinoma (MGC), measuring less than 5 mm in greatest dimension, has been considered to represent the incipient phase of gastric carcinoma. To determine the clinicopathologic features of MGCs, the authors examined tissues from MGCs with a view to clarifying their histopathologic diversity. The immunohistochemistry of these tissues was determined using monoclonal antibody against p53 and Ki-67, and their mucin-histochemical types were determined with reference to the presence of intestinal metaplasia (IM) within their surrounding mucosa. METHODS: One hundred three specimens were obtained from 93 patients with MGCs. Each lesion was evaluated both macroscopically and histologically, and the degree of IM was assessed. All sections were examined mucin-histochemically with Con A, GOS, and HID-AB, and stained with commercially available monoclonal antibodies, PAb 1801 and Ki-67. Additional nonminute carcinomas present within the same stomachs were used as controls. RESULTS: Macroscopically, most lesions were depressed. IM was noted in the surrounding mucosa of 85 MGCs (82.5%). Immunohistochemically, 25 MGCs (24.2%) showed p53 overexpression, although the rate of p53 overexpression was increased to 34.6% in other nonminute carcinomas from the same stomachs. Twenty-four MGCs were associated with a proliferative zone, demonstrated by Ki-67 positive cells. Statistically significant differences in the rate of p53 overexpression were observed between MGCs with a proliferative zone and those without. Mucin phenotypes of MGCs tended to imitate their own surrounding mucosa. CONCLUSIONS: The MGCs, which represent the incipient phase of early gastric carcinoma, have various histologic, immunohistochemical, and mucin-histochemical features. It would seem that p53 expression is more closely related to the progression of MGCs than to their carcinogenesis.

Adult↗
PubMed1999

Apoptosis and cell proliferation in medullary carcinoma of the breast: a comparative study between medullary and non-medullary carcinoma using the TUNEL method and immunohistochemistry.

BACKGROUND AND OBJECTIVES: Medullary carcinoma of the breast has generally been considered to result in better prognosis than ordinary invasive ductal carcinoma, which would seem to be discrepant when one considers its anaplastic histology and high mitotic rate. We attempted to elucidate the prognostic implications of apoptosis and cell proliferation in medullary carcinoma of the breast. METHODS: Formalin-fixed, paraffin-embedded specimens of 50 cases of typical medullary carcinoma (MC) of the breast and those of 50 control cases of non-medullary invasive ductal carcinoma (N-MC), which were matched to the MC cases in both age and TNM classification, were investigated utilizing the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method and immunohistochemistry for p53, bcl-2, and Ki-67. RESULTS: Mean values of the apoptotic index (AI), the proliferative index (PI), and the ratio of AI to PI (AI/PI) were significantly higher in MC than in N-MC (P < 0.0001). MC exhibited significantly lower positivity for bcl-2 than N-MC (P = 0.00003), while there was no significant difference in p53 positivity between MC and N-MC. CONCLUSIONS: A high frequency of apoptosis may be related to a favorable prognosis in MC, even though it demonstrates a high proliferative activity, exhibiting a rapid cell turnover.

Adult↗
PubMed1999

A clinicopathological study in young patients with gastric carcinoma.

BACKGROUND AND OBJECTIVES: Gastric carcinoma rarely affects young patients. This study was undertaken in order to clarify the clinicopathological features and prognosis of young patients with gastric carcinoma. METHODS: The resected 107 specimens from 105 patients younger than 30 years of age with gastric carcinoma were investigated using hematoxylin and eosin stain. RESULTS: The male:female ratio was 1:1.6. Histologically, poorly differentiated adenocarcinoma was the most common type (94/107, 87.9%) (P < 0.001). Most tumors were located in the middle third of the stomach (P < 0.001). All patients had depressed lesions. The 5-year survival rates of early and advanced gastric carcinoma were 100% (30/30) and 23.5% (8/34), respectively. CONCLUSIONS: Characteristic clinicopathological features in young patients, such as gender ratio, tumor location, macroscopic type, and histological type, were different from those in older ones. The prognosis of early gastric carcinoma in young patients was much better than that in older patients, although the prognosis of advanced gastric carcinoma in young patients was worse than that of older patients. These findings seem to indicate that young patients with early gastric carcinoma can tolerate radical treatments well; however, the aggressiveness of lesions are emphasized in patients with advanced gastric carcinoma.

Adenocarcinoma↗
PubMed1999

'Serrated' adenoma of the colorectum, with reference to its gastric differentiation and its malignant potential.

Serrated adenoma of the colorectum was a newly proposed entity in 1990, characterized by epithelial neoplasia combining the architectural features of a hyperplastic (metaplastic) polyp with the cytological features of an adenoma. Its histogenesis and natural history still remain unclear. Forty-six serrated adenomas were obtained from 46 patients. The clinicopathological features were summarized. Paraffin-embedded blocks from 34 serrated adenomas were available for immunohistochemical studies using pS2, human gastric mucin, and p53 protein. Eighteen hyperplastic (metaplastic) polyps, 16 tubular adenomas, and 12 early-stage adenocarcinomas were randomly selected as control groups for immunohistochemical analysis. The patients' ages ranged from 32 to 86 (average 61.4) years. Males were more frequently affected than females. Serrated adenomas were predominantly present in the left-side of the colon and in the rectum (72 per cent). Their sizes ranged from 3 to 26 mm (average 9. 2mm). Six lesions (13 per cent) contained foci of high-grade dysplasia. These adenomas were significantly larger (12.7 mm) than those containing no high-grade dysplasia (8.6mm). pS2 and human gastric mucin were expressed significantly more frequently in both hyperplastic (metaplastic) polyps and serrated adenomas than in tubular adenomas or adenocarcinomas. p53-positive cells were present in 18 of the 29 pure serrated adenomas (62 per cent) and in one of the five areas of low-grade dysplasia in serrated adenomas with high-grade dysplasia (20 per cent), most of which revealed a sporadic distribution. Only five of the 29 serated adenomas with no high-grade dysplasia (17 per cent) were regarded as demonstrating p53 overexpression. On the other hand, three of the five areas of high-grade dysplasia in serrated adenomas (60 per cent) revealed diffuse positivity (3+) for p53 protein. The serrated adenoma, which possibly shows gastric differentiation, is considered to be an independent histological entity among the various phenotypes of colorectal adenomas. Serrated adenoma would seem to be a precursor of carcinoma, its potential for malignant transformation being similar to that of the traditional tubular adenoma. It would also seem that p53 is involved in the serrated adenoma-carcinoma sequence.

Adenoma↗
PubMed1999

Composition and structure of the apatite formed on PET substrates in SBF modified with various ionic activity products.

An apatite layer was formed on polyethyleneterephthalate (PET) substrates by the following biomimetic process. PET substrates were 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 (first treatment). They then were soaked in modified SBFs, the ion concentrations of which were changed to give a variation in ionic activity product of apatite (IP), in order to make the apatite nuclei grow (second treatment). The Ca/P atomic ratio and the lattice constant c of the formed apatite decreased from 1.54 to 1.40 and from 6.880 to 6.838 A, respectively, with increasing ion concentrations from 0.75 to 2.00 times those of SBF, that is, with increasing IP from 10(-96.6) to 10(-91.9). This was attributed to an increase in the concentration of HPO4(2-) ion substituting for the PO4(3-) ion sites, which gave an increase in the Ca2+ in the apatite. Even the apatite formed in 1.00 SBF showed a Ca/P ratio of 1.51 and lattice constants a of 9.432 A and c of 6.870 A. The Ca/P ratio and lattice constant c were smaller and the lattice constant a was larger than those of the bone apatite; its Ca/P ratio and its lattice constants a and c, were 1.65, 9.419 A, and 6.88 A, respectively. This was attributed to the lower content (2.64 wt%) of the CO3(2-) ion substituting for the PO4(3-) ion sites of the apatite compared to that of the bone apatite (5.80 wt%). The lower content of the CO3(2-) ion in the apatite might be caused by the lower concentration of HCO3- ion in 1.00 SBF compared to that in human blood plasma.

Apatites↗
PubMed1999

Preoperative detection of occult enterovesical fistulas in patients with Crohn's disease: efficacy of oral or rectal administration of indocyanine green solution.

OBJECTIVES: Nonhazardous enteral administration of indocyanine green solution was performed to detect enterovesical occult microfistulas in patients with Crohn's disease before the fistulas had become readily apparent. METHODS: A total of 12 patients with Crohn's disease who were suspected from their clinical manifestations of having enterovesical fistulas underwent study. For detection of the fistulas after oral or rectal administration of the indocyanine green solution, urine was collected and examined using a colorimeter to check for contamination with indocyanine green. The effectiveness of the indocyanine green test and conventional x-ray study was compared. RESULTS: The indocyanine green test was positive after either oral or rectal administration in 11 of the 12 patients, providing a rate of accurate diagnosis of 92 percent (11/12 patients). In contrast, the rate of accurate diagnosis using the x-ray study was only 17 percent (2/12 patients). Furthermore, in eight patients with occult fistulas, accurate diagnosis could be made in none using the x-ray study, whereas all showed positive results with use of the indocyanine green test. CONCLUSIONS: The ability to diagnose obscure fistulas using the indocyanine green test was 92 percent. This indocyanine green test was highly diagnostic, whereas conventional examinations are often complicated and much less diagnostic.

Administration, Oral↗
PubMed1999

The effectiveness of chemotherapy with cisplatin and 5-fluorouracil for recurrent small cell neuroendocrine carcinoma of the rectum: report of a case.

We report herein the case of a 46-year-old-man with small cell neuroendocrine carcinoma (NEC) concomitant with large villous adenoma of the rectum, who underwent abdominoperineal resection with regional lymphnode dissection. The resected specimen was histologically found to contain a small lesion of NEC confined to the submucosa in the large adenoma. A computed tomography scan done 4 months postoperatively revealed recurrences in the liver, lymph nodes, and bone. Therefore, two cycles of sequential intravenous combined chemotherapy with standard doses of cisplatin and 5-fluorouracil (5-FU) were administered, after which the size of each tumor decreased remarkably. Nevertheless, the patient died 8 months after the operation. As there was a fair response of this tumor to the combined chemotherapy of cisplatin and 5-FU, this regimen against NEC of the colon and rectum should be given consideration.

Adenoma, Villous↗