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T Yao

Publications and source records attributed to T Yao.

At least 217 records · Page 12Linked to original sources
PubMed1994

Immunological studies on Crohn's disease. X. Conclusion: a new tentative hypothesis.

Although much progress has been made in understanding the pathogenesis of Crohn's disease, the precise etiology of Crohn's disease still remains unknown. In our serial studies on Crohn's disease, we found a decrease in NK and ADCC activities as well as a decrease in the phagocytic activity by monocytes, whereas an increased superoxide production activity by monocytes was evident. On the other hand, the characterization of lymphocyte subpopulations has demonstrated no abnormalities. According to these findings, we would like to propose a new tentative hypothesis for the pathogenesis of Crohn's disease. It has been suggested that impaired killing system activities, such as phagocytic activity as well as NK and ADCC activities, are primarily responsible for the promotion and perpetuation of chronic inflammation and ulceration. When our attention is directed to the most common target substances of these protective mechanisms, viral antigens appear as the most likely causative organism. Therefore, a lot of attention has been focused on viral infection as a causative factor. Furthermore, based on this hypothesis, strategies for effective treatment of this disease are also discussed.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1994

Intestinal lymphangiectasia: value of double-contrast radiographic study.

Intestinal lymphangiectasia is a disorder presenting as enteric protein loss through the dilated lymphatics without mucosal ulceration. To determine the double-contrast radiographic features and to assess the significance of them, five patients with intestinal lymphangiectasia were examined using single- and double-contrast small intestinal studies. The double-contrast examinations demonstrated clearly the main radiographic findings of smooth nodular protrusions, thickening of the mucosal folds, with no evidence of mucosal ulceration. Compared with the single-contrast study, smooth nodular protrusions were seen more often and in more widespread segments, particularly in the duodenum, on double-contrast study. Thickening of the mucosal folds was revealed similarly by both methods. Double-contrast study appears to be worthwhile to demonstrate the characteristic radiographic findings of this disease.

Adolescent↗
PubMed1994

Gastrointestinal manifestations of Cowden's disease. Report of four cases.

Four patients with an established diagnosis of Cowden's disease underwent barium meal study, upper gastrointestinal endoscopy, barium enema examination, and colonoscopy. In three, the esophagus was affected by small protrusions, which were diagnosed as glycogenic acanthosis. Numerous hyperplastic polyps were found in the stomach in three patients, and in one an inflammatory fibroid polyp was also detected. Either lymphangiectasia or lymphoid polyps were found in the duodenum in two patients. In all patients, the colon showed polyps that varied in histology and included adenoma, hamartomatous polyp, and ganglioneurofibroma. In addition, jejunal lymphangiomas were found in one of the three patients in whom the small intestine could be precisely evaluated. These findings suggest that the gastrointestinal involvement in Cowden's disease is characterized by various benign lesions, especially esophageal glycogenic acanthosis, numerous gastric hyperplastic polyps, and multiple hamartomatous polyps in the rectosigmoid colon. Detection of these gastrointestinal manifestations may lead to early diagnosis of this potentially malignant disease.

Adult↗
PubMed1994

Gastrointestinal involvement in tuberous sclerosis. Two case reports.

Two patients with tuberous sclerosis had multiple semispherical polyps in the large intestine, predominantly in the rectosigmoid colon. These were hamartomas with an excess of smooth muscle fibers in the stroma. In addition, the 21-year-old man had multiple tiny protrusions in the esophagus and oral fibroepithelial polyps. In the 31-year-old woman, who had pulmonary lymphangiomyomatosis with positive estrogen and progesterone receptors, hamartomatous gastric polyps, colonic leiomyoma, and adenomatous rectal polyps were also identified. Our findings suggest that gastrointestinal polyposis may be one of the phenotypes of tuberous sclerosis complex, possibly linking this disease with other hereditary polyposis syndromes.

Adult↗
PubMed1994

Risk factors related to liver metastasis in colorectal carcinoma: a multivariate analysis of clinicopathologic and immunohistochemical variables.

Specimens from 48 consecutive patients undergoing surgery for colorectal carcinoma and having synchronous or metachronous liver metastases (Group 1) and those from 52 consecutive patients who had no evidence of hepatic metastases within at least 5 year after colorectal resection (Group 2) were selected and compared using a multiple logistic regression analysis. A multivariate analysis using a stepwise logistic regression revealed six independent risk factors significantly related to hepatic metastases. In addition, the following logistic regression model was obtained from this analysis. P = exp a/(1 + exp a): a = 3.524(SM-V) + 2.731(Ex-V) + 2.718(E/M) + 2.562(Lo) + 1.858(p53) + 1.941(HIR) - 4.397, where P is the probability of hepatic metastasis given six independent risk factors (E/M, Ex/M ratio; Lo, location; HIR, host inflammatory cell reaction). When the estimated probability "P" in the above logistic regression model is more than 0.55 after an examination of surgical specimens, we must consider adjuvant chemotherapy and closely monitor the patient to ensure early detection of hepatic metastases.

Adenocarcinoma↗
PubMed1994

Depressed adenoma of the colorectum: analysis of proliferative activity using immunohistochemical staining for proliferating cell nuclear antigen (PCNA).

Recently, depressed adenomas (DA) of the colorectum have been frequently detected in Japan. The natural history and carcinogenesis of these DA remain unclear. The histological features and cell kinetics of 13 DA were analyzed, using proliferating cell nuclear antigen (PCNA), and compared with 24 non-depressed adenomas (NDA), 12 non-neoplastic mucosa and 12 adenocarcinomas. The DA had a characteristic architecture when compared with the NDA, as demonstrated by a crowded collection of adenomatous tubules with small diameters. The adenomatous tubules tended to occupy the full thickness of the lamina propria at the center with superficial growth to the periphery. The PCNA-positive cells were mostly restricted to the lower half of the crypts in the non-neoplastic mucosa, and were distributed predominantly across the upper half area of the crypts in both the DA and NDA, whereas they were randomly distributed across any area in the adenocarcinomas. The mean labeling index of PCNA in the DA (43.2%) was significantly higher than that in the non-neoplastic mucosa (26.5%) and NDA (29.3%), but lower than that in the intramucosal component of the adenocarcinomas (70.0%). The DA should be seriously considered as a precancerous lesion because of its unusual histologic architecture and high proliferative activity.

Adenocarcinoma↗
PubMed1994

Gastrointestinal amyloidosis: radiologic features by chemical types.

PURPOSE: To determine the correlation between the radiographic and histologic findings of amyloidosis according to chemical type of amyloid protein. MATERIALS AND METHODS: The 49 patients with amyloidosis were examined radiographically, and gastrointestinal tract biopsy specimens were studied histologically. RESULTS: Considerable differences were found between amyloid proteins. On immunohistochemical studies, amyloid A produced a coarse mucosal pattern with innumerable fine granular elevations, which reflected expansion of the lamina propria by amyloid deposits. Polypoid protrusions and invariable thickening of the folds were evident only in light chain protein, correlating with massive amyloid deposits in the muscularis mucosae and submucosa. beta 2-Microglobulin produced marked delay in transit time and dilatation of the small and large intestines, relating to extensive amyloid deposits in the muscularis propria. The prevalence of these radiographic changes was highest in the small intestine for every chemical type. CONCLUSION: Characteristic radiographic changes of each chemical type of amyloid protein can be detected well in the small intestine.

Adult↗
PubMed1994

Crohn disease: early recognition and progress of aphthous lesions.

PURPOSE: To clarify the radiographic appearance of the initial change an dprogression in Crohn disease. MATERIALS AND METHODS: Between 1984 and 1992, nine patients (seven men and two women, aged 16-34 years; mean, 20 years) with Crohn disease, who had evidence of only aphthous erosions or ulcers at the initial examination, underwent repeated radiography for up to 7 years 11 months (median, 4 years). RESULTS: In all patients, the stomach, duodenum, small intestine, and colorectum were involved, and the esophagus was affected in three patients. Subsequently, four of the nine patients had lesions that progressed from aphthous lesions to overt Crohn disease, including ileitis in two patients, colitis in one, and ileocolitis in one. Time intervals between the first visit and the progression varied from 9 months to 3 years 6 months. In all eight patients who underwent nutritional treatment, regression of the lesions was recognized, but three of the lesions progressed during interruption of the nutritional diet. CONCLUSION: Crohn disease may initially appear as diffuse aphthous lesions in the gastrointestinal mucosa.

Adolescent↗
PubMed1994

Mucosal prolapse syndrome: diagnosis with endoscopic US.

PURPOSE: To determine the value of endoscopic ultrasound (US) in the diagnosis of mucosal prolapse syndrome (MPS), also known as solitary ulcer of the rectum. MATERIALS AND METHODS: Three male and two female patients (age range, 17-66 years) with biopsy-proved MPS underwent endoscopic US. The average rectal wall thicknesses of the affected areas were compared with those of normal-appearing mucosa. RESULTS: The gross appearance of the rectal lesions was classified into three types: polypoid (n = 2), flat (n = 1), and ulcerative (n = 2). In all three types of lesions, endoscopic US demonstrated smooth, diffuse thickening of the third layer of the rectal wall; the other layers had minimal thickening. Neither a solid hypoechoic mass nor a transmural infiltrating lesion was visible, and the five-layer structure of the rectal wall was completely preserved. In the polypoid lesions, the third layer was winding as well as thickened, and microcystic components were occasionally found. CONCLUSION: Endoscopic US enabled differentiation of MPS from other conditions such as malignant neoplasia and Crohn disease.

Adult↗
PubMed1994

Inhibition of carbon tetrachloride-induced liver injury by liposomes containing vitamin E.

We tested a variety of antioxidants as possible therapeutic agents in an acute CCl4 mouse model of hepatotoxicity. Liver damage, gauged by the amount of serum aminotransferase released into the blood, morphological changes, lethal dose response, and presence of thiobarbituric acid-reactive substances (TBARS), were significantly inhibited in a dose-dependent manner by liposomes containing vitamin E (LVE) or by Rocavit E, a water-soluble emulsion of alpha-tocopherol. Serum aminotransferase levels in LVE- or Rocavit E-treated animals were always > 10-fold lower than levels in corresponding CCl4 controls. Other liposome-associated antioxidants, butylated hydroxytoluene, vitamin E succinate, catalase, desferoxamine, superoxide dismutase, and ascorbic acid 6-palmitate, were also able to elicit a decrease in damage; however, they were substantially less effective. Intravenous therapy with LVE decreased mortality by nearly 90% when a lethal dose of CCl4 was given. When the biodistribution of the liposomes was examined, it was determined that the vast majority were localized in the Kupffer cell population. This approach of delivering nontoxic therapeutic agents selectively to the liver offers a variety of clinical applications in humans.

Animals↗
PubMed1994

Colorectal counterpart of gastric depressed adenoma. A comparison with flat and polypoid adenomas with special reference to the development of pericryptal fibroblasts.

The histological features of 28 depressed adenomas (DAs) were compared with those of 40 flat adenomas (FAs) without a central depression and those of 29 polypoid adenomas (PAs), with special reference to the development of pericryptal fibroblasts (PCFs), using immunohistochemical staining for muscle-specific actin (HHF-35). The DAs were composed of a crowded collection of adenomatous tubules with smaller diameters than those of the PAs. With regard to PCF development, the DAs had poorly developed PCFs; PCF (-), (+), and (++) numbered 12 (43%), 16 (57%), and 0 (0%), respectively. On the other hand, the nondepressed adenomas (PAs and FAs) had well-developed PCF; PCF (-), (+), and (++) numbered 5 (7%), 35 (51%), and 29 (42%), respectively. In addition, the number of PCFs seemed to decrease in the sequence of PAs, followed by FAs and DAs. According to our results, the DAs had a characteristic histological architecture together with poorly developed PCFs features, which distinguished them from the PAs. In conclusion, the depressed adenomas were considered a subtype of the flat adenomas. The depletion of PCFs seems to correlate with the depressed growth of the adenoma.

Actins↗
PubMed1994

[A new index of disease activity in Crohn's disease].

A comprehensive assessment including subjective and objective parameters seems to be essential for evaluation of disease activity in Crohn's disease. The aim of the present study was to develop an activity index (AI) of Crohn's disease, composed of both subjective and objective variables. Data composed of a total 132 clinical examinations in 100 patients with Crohn's disease were used to determine the AI. Three physicians independently evaluated disease severity in each patient. Stepwise multiple regression analysis was carried out with the overall evaluation as a dependent variable, and with 18 parameters as independent variables. Analysis showed that the following seven variables had a significant correlation with physician's overall evaluation: abdominal pain, abdominal tenderness, complications, C-reactive protein (CRP), body temperature, diarrhea, and body mass index (BMI). AI was expressed as follows: AI = 3.5 x abdominal pain + 3 x abdominal tenderness + 3 x complications + CRP + 3 x body temperature + 4 x diarrhea - 0.4 x BMI. AI values below 15 corresponded to inactive disease, values between 15 and 25 to mild disease, values between 25 and 35 to moderate disease, and values above 35 to severe disease. This study suggests that the activity index is useful for evaluation of the effect of medical treatment in Crohn's disease.

Adult↗
PubMed1994

[Randomized controlled trial of amino acid based diet versus oligopeptide based diet in enteral nutritional therapy of active Crohn's disease].

This study compared the short-term effect of semi-elemental diet in treatment of active Crohn's disease with elemental diet which has been reported to be successful in inducing remission. The important differences between semi-elemental diet and elemental diet in composition are the form of nitrogen and fat content. Forty patients with active Crohn's disease were randomized to receive for 6 weeks either elemental diet (n = 21) which is composed of amino acid based with low fat content or semi-elemental diet (n = 19) which is oligopeptide-based and has higher fat content. Both groups showed similar improvement in Dutch-AI, Crohn's disease activity index (CDAI), erythrocyte sedimentation rate, C-reactive protein, serum albumin, body mass index and radiographic findings of bowel lesion. The present study suggests that semi-elemental diet is equal to elemental diet for treating active Crohn's disease. We conclude the compositional differences between the two diets did not affect the short-term effect of enteral nutritional therapy for active Crohn's disease.

Adult↗
PubMed1994

Comparison of the effects of single morning and single bedtime doses of famotidine on intragastric acidity in patients with gastric ulcer.

The effects of single morning and single bedtime doses of famotidine on intragastric acidity were studied by 24-h intragastric pH monitoring in 16 patients with gastric ulcer. The patients were randomly allocated to the following regimen: one group (n = 8) received 40 mg famotidine at 8:30 AM and another group (n = 8) received the same dose at 10 PM. The morning group showed significant inhibition of gastric acidity during the 24-h and daytime measurements, compared to those of the bedtime group (p < 0.05 in 24 h, p < 0.01 in daytime). Conversely, the bedtime group showed a significant inhibition of gastric acidity during the nocturnal period compared to the morning group (p < 0.01). These results indicate that the relative importance of suppression of gastric acidity on the gastric ulcer healing process should be evaluated in a clinical trial.

Drug Administration Schedule↗
PubMed1993

Time trends of early gastric carcinoma. A clinicopathologic analysis of 2846 cases.

BACKGROUND: Despite recent improvements in the diagnostic accuracy and techniques for identifying early gastric carcinoma, gastric carcinoma remains a major cause of death in the world. METHODS: The clinicopathologic features of 2846 surgically resected early gastric carcinomas from 1962-1987 were reviewed, and the time trends of a variety of clinicopathologic factors were studied using both an univariate and a multivariate analysis. RESULTS: The differentiated type of carcinoma increased in frequency from 34-50%. The percentage of patients older than 60 years of age increased from 32-56%. The number of lesions measuring less than 3 cm increased from 28-56%. The frequency of shallow-type-IIc carcinomas measuring less than 3 cm, which had been previously difficult to detect and were mainly composed of differentiated carcinomas, increased from 46-69%. The relative proportion of the differentiated type of carcinoma was significantly higher in patients older than 60 years of age than in those younger than 60. The relative proportion of differentiated-type carcinomas measuring less than 3 cm, which had been easy to detect as opposed to undifferentiated-type carcinomas, significantly increased from 56-76%. CONCLUSIONS: The above time trends may indeed reflect genuine change. However, the recent increase in the rate of differentiated-type, small-sized carcinomas also suggests the possibility that such results may, in fact, be due mainly to improvements in both diagnostic accuracy and medical technology. Thus, a large number of undifferentiated-type, small-sized carcinomas might have merely failed to be found in routine gastric examination.

Age Factors↗
PubMed1993

Cancer in Peutz-Jeghers syndrome.

BACKGROUND: Peutz-Jeghers (P-J) syndrome has been found to be associated with an increased risk of malignant neoplasia. METHODS: The authors reviewed the clinical courses of eight patients with P-J syndrome (four male and four female patients, ranging in age from 8 to 55 years), who had been followed up for as long as 12 years. The diagnosis of this syndrome was based on the evidence of characteristic mucocutaneous pigmentations and gastrointestinal hamartomatous polyposis. RESULTS: Four cases of malignant neoplasm among the eight patients were found. In a 25-year-old woman, an extremely well-differentiated adenocarcinoma of the uterus cervix was found at the initial examination. A gastric cancer in a 32-year-old woman, duodenal cancers in a 43-year-old man, and a pancreatic cancer in a 60-year-old man also were identified 12, 10, and 5 years after the time of initial examinations, respectively. Two of these patients died of the effects of the tumor soon after. CONCLUSION: The authors' experience confirms a veritable malignant potency in P-J syndrome and suggests that an intensive follow-up of gastrointestinal and extra-gastrointestinal sites is needed in patients with this syndrome.

Adolescent↗