Temperature dependence of the photoluminescence of ZnSe/ZnS quantum-dot structures.
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
T Yao
Publications and source records attributed to T Yao.
Control of gastric pH with ranitidine in patients with Crohn's disease receiving total parenteral nutrition. Comparison of two intravenous regimens.
Eleven patients with Crohn's disease in remission who were receiving total parenteral nutrition (TPN) underwent continuous intragastric 24-h pH monitoring before and during ranitidine administration. The patients were randomly allocated to receive 200 mg/day (group 1) or 400 mg/day (group 2) of ranitidine by continuous infusion. The mean basal 24-h gastric pH was sustained at a low value. After raintidine administration, the mean pH increased significantly both in group 1 (from 2.13 to 3.28) and in group 2 (from 1.91 to 3.36), with the mean holding-time at pH-3 also increasing significantly in both groups. There were no differences in the mean pH or holding-time at pH-3 between the two groups during ranitidine administration; however, the plasma ranitidine concentration was significantly higher in group 2. These findings indicate that the continuous infusion of a standard dose of ranitidine exerted a maximal inhibitory effect on the sustained hyperacidity induced by TPN, but that this infusion was unable to maintain the intragastric pH level at above 3.5.
Adolescent↗
Increased numbers of macrophages in noninflamed gastroduodenal mucosa of patients with Crohn's disease.
We investigated immunostained macrophages in the noninflamed mucosa of Crohn's disease patients. Biopsied specimens from endoscopically normal gastroduodenal mucosa of Crohn's disease, ulcerative colitis, and healthy control patients were studied. Sections were examined immunohistochemically using a monoclonal antibody specific for tissue macrophages (CD68). Immunostained mucosal macrophages in the second part of the duodenum, duodenal bulb, gastric antrum, and gastric body of the Crohn's disease group were more numerous than in the ulcerative colitis and control groups. The characteristic findings of Crohn's disease were aggregations, focal subepithelial dense accumulations, and infiltration throughout the mucosa of macrophages not accompanied by a lymphoid infiltrate. The number of macrophages in the gastroduodenal mucosa bore no relationship with the duration of symptoms, clinical activity, or affected site in the intestine. This suggests that the increased number of macrophages in noninflamed mucosa is a histological change characteristic for Crohn's disease that indicates a persistent latent abnormality involving the entire gastrointestinal tract.
Adolescent↗
Right-sided ulcerative colitis.
This report describes a case of right-sided ulcerative colitis in which multiple shallow ulcers and erosion with symmetric luminal stenosis were distributed segmentally from the ascending colon to the cecum, with a skip lesion composed of superficial erosions in the right half of the transverse colon. Both the rectum and the left colon were spared at the time of onset. Biopsies taken from the lesions showed non-specific inflammation, while those from the rectum and sigmoid colon showed no abnormal findings. A 5-year follow-up study was made based on radiography and endoscopy. Other inflammatory bowel diseases, such as Crohn's disease, tuberculosis, Yersinosis, Behçet's disease, and ischemic colitis were all ruled out, based on the macroscopic and microscopic findings as well as the clinical course. To our knowledge, this is the first report of right-sided ulcerative colitis that has been followed for a long period.
Adult↗
Inverse correlation between the expression of bcl-2 and p53 proteins in primary gastric lymphoma.
The immunohistochemical expression of bcl-2 and p53 proteins was evaluated in formalin-fixed, paraffin-embedded surgical specimens from 212 patients with primary gastric lymphoma. bcl-2 protein was found to be expressed in 145 specimens (68%). Among the 179 specimens with B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), bcl-2 positivity decreased significantly as the histological grade advanced; bcl-2 was expressed in 93% of low-grade tumors, 88% of mixed-grade (low-grade with a focal high-grade component) tumors, and 44% of high-grade tumors (Cochran's linear trend test; P<.001). p53 protein expression was detected in 43 of 212 cases (20%). Among the B-cell MALT lymphomas, p53 positivity increased significantly as the histological grade advanced; p53 was expressed in 6% of low-grade tumors, 12% of mixed-grade tumors, and 31% of high-grade tumors (Cochran's linear trend test; P<.001). An inverse correlation was observed between the expression of bcl-2 and p53 in all 212 lymphomas (gamma = -0.531; P<.05) as well as in all 179 B-cell MALT lymphomas (gamma = -0.671; P<.01). Although the bcl-2 expression did not correlate with the patient survival, the p53 positive cases showed a significantly poorer prognosis compared with the p53 negative cases (log-rank test; P<.05). These results suggest that the expression of bcl-2 and p53 may, therefore, be associated with the transition from low-grade to high-grade tumors in primary gastric lymphoma.
Adolescent↗
Chronic irradiation enteritis: its correlation with the elapsed time interval and morphological changes.
Twenty-one lesions from 19 patients with chronic irradiation enteritis (CIE) were examined to elucidate correlations with the histological findings and either the elapsed time interval or the macroscopic features. The lesions were divided into the early CIE group (E group; the lesions resected within 2 years after irradiation) of 10 lesions and the late CIE group (L group; the lesions resected more than 8 years after irradiation) of 11 lesions. Based on the macroscopic features, the lesions of CIE were divided into three types: ulcerative stricture type (U type; 11 lesions), serosal adhesion type (A type; 6 lesions) and wall sclerosing type (S type; 4 lesions). Only A type lesions were observed in the E group, and U type lesions were significantly more frequently encountered in the L group (9 of 11; 82%) than in the E group (2 of 10; 20%). Moderately to markedly degenerated changes of the vessel wall (8 of 11; 73%), enteritis cystica profunda (8 of 11; 73%), atypical epithelia (7 of 11; 64%), and the occurrence of fistula (2 of 11; 18%) were all significantly more frequently present in the L group than in the E group. No radiation-induced colorectal carcinomas were observed. The authors thus conclude that CIE is a slowly progressive disease. The late CIE showed macroscopically ulcerative stricture type properties with tissue degradation, such as fistulas, perforation, and dysplastic epithelia compared with early CIE; thus, long-standing CIE should be followed for the early identification of further complications. The classification of CIE based on macroscopic features is, therefore, considered to be useful to understand the clinical course of this disease better.
Abdomen↗
The demonstration of pericryptal fibroblasts in background mucosa and dysplasia complicating ulcerative colitis.
The demonstration of pericryptal fibroblasts in background mucosa and dysplasia in ulcerative colitis was investigated by immunohistochemistry using monoclonal antibody for alpha-smooth muscle actin. Pericryptal fibroblasts were reduced in 18 (26%) of the 68 sections of non-dysplastic mucosa. The reduction was significantly correlated with goblet cell depletion and villous change. Pericryptal fibroblasts were more frequently reduced (50%) in dysplastic mucosa, the reduction being greater in villous than in non-villous dysplasia. Pericryptal fibroblast development was not related to grade of dysplasia (low or high-grade), distance from carcinoma (adjacent to or distant from carcinoma) or growth pattern (polypoid or non-polypoid). These findings suggest that: 1 reduction of pericryptal fibroblasts in background mucosa may relate to the development of dysplasia in ulcerative colitis, 2 reduction of pericryptal fibroblasts in villous regeneration, analogous to that in dysplasia, reinforces the hypothesis that villous change may be a marker for risk of development of carcinoma in ulcerative colitis.
Colitis, Ulcerative↗
Vimentin-positive adenocarcinomas of the stomach: co-expression of vimentin and cytokeratin.
Recently, the expression of vimentin has been reported in some carcinomas. This study was designed to clarify the significance of vimentin expression in solid type poorly differentiated adenocarcinomas of the stomach. Immunohistochemically, 239 poorly differentiated adenocarcinomas with solid components of the stomach were stained for vimentin. Vimentin-positive cases were also stained by CAM 5.2 using serial mirror sections. We found 15(6.3%) vimentin-positive cases. Twelve of them demonstrated varying amounts of rhabdoid-like cells. Eight cases diffusely co-expressed vimentin and cytokeratin simultaneously. In addition, four co-expressing cases showed positive staining with Keratin-903 which recognizes the high molecular-weight cytokeratin. Most of the co-expressing cases showed a diffuse proliferation of polygonal tumour cells with focal cell-to-cell contact. The prognosis of the co-expressing cases was poor in comparison with that of the 89 vimentin-negative tumours (P < 0.05).
Adenocarcinoma↗
Jejunal myoepithelial hamartoma associated with Gardner's syndrome: a case report.
Explore the source record for details and available documents.
Adult↗
Suture granuloma in rectal anastomosis mistaken for locally recurrent cancer.
Explore the source record for details and available documents.
Aged↗
Jejunal angiodysplasia confirmed by intravascular injection technique in vitro. Report of a case and review of the literature.
Angiodysplasia of the small intestine is a rare but important cause of gastrointestinal bleeding. We present a 64-year-old man with repeated melena in whom the diagnosis of multiple angiodysplasia of the jejunum was suggested by angiography. The affected segment of the small intestine, in which reddish patches were detected by intraoperative endoscopy, was removed. The combined technique of injecting a dye and a water-soluble contrast medium into the resected specimen revealed areas of dilated vessels, which were diagnosed histologically as angiodysplasia. This case suggests that angiodysplasia of the small intestine can be recognized clinically before the operation and that the intravascular injection technique is useful in confirming the diagnosis in the resected specimen in vitro. We describe this case in detail and review other cases of small intestinal angiodysplasia reported in the English literature.
Angiodysplasia↗
p53 expression patterns in colorectal adenomas and early carcinomas: a special reference to depressed adenoma and non-polypoid carcinoma.
The purpose of the present study was to investigate the role of p53 in tumor progression of colorectal adenomas and early carcinomas, while especially focusing on flat tumors (depressed adenomas and non-polypoid carcinomas). Paraffin sections of 61 pure adenomas (33 polypoid, 28 depressed), 26 carcinomas in polypoid adenoma (CIA) and 63 pure carcinomas (36 polypoid, 27 non-polypoid) were examined for immunostaining using p53 monoclonal antibody (PAb 1801). All of the carcinomas were restricted to the mucosa. The number and distribution of the p53 positive tumor cells was evaluated, and then compared with tumor growth patterns and histological features. The incidence of p53 expression in carcinomas (58% in CIA and 51% in pure carcinomas) was significantly higher than that in polypoid adenoma (27% in CIA and 21% in pure adenomas). However, the same incidence in depressed adenomas (51%) was significantly higher than in polypoid adenomas. No correlation in carcinomas was observed between p53 expression and clinicopathologic data except for age. The distribution of p53 positive cells was different between adenomas and carcinomas. There tended to be fewer p53 positive cells in adenomas, even in depressed ones, than in carcinomas and they also tended to be confined to the superficial areas in adenomas, while they were diffusely distributed in carcinomas. Interestingly, the p53 positive cells were more frequently present in the deep mucosal areas than in the superficial areas of some non-polypoid carcinomas. In conclusion, the following hypotheses are suggested: (i) the increase of p53 expression from adenoma to carcinoma supports the hypothesis of an adenoma-carcinoma sequence in a polypoid tumor; (ii) the unique p53 expression in non-polypoid carcinoma suggests the existence of another type of carcinogenesis; and (iii) depressed adenomas are thus considered to have a high potential risk of carcinoma.
Adenoma↗
Association between thyroid cancer of cribriform variant and familial adenomatous polyposis.
A case of a 20 year old Japanese woman who developed thyroid cancer exhibiting unusual cribriform structures while being followed up for familial adenomatous polyposis/Gardner's syndrome is reported. The patient presented with osteomas, pigmented retinal lesions, and adenomas of the duodenum and the papilla of Vater, in addition to numerous adenomatous polyps in the colorectum. On ultrasonography, the thyroid cancer was localised to the right lobe and was identified as an irregular, internal echo tumour with a peripheral hypoechoic zone, measuring 1.8 cm in diameter. Histological examination of the resected tumour showed a concomitance of papillary proliferation and cribriform structures with follicles of varying sizes. These features can be distinguished from sporadic thyroid cancer.
Adenocarcinoma↗
Dysplasia in ulcerative colitis: is radiography adequate for diagnosis?
PURPOSE: To determine to usefulness of barium enema examination in detecting dysplasia in patients with ulcerative colitis. MATERIALS AND METHODS: Radiographic findings of 22 areas of dysplasia in 10 patients (seven men, three women; aged 34-81 years at diagnosis) were reviewed. Serial changes in radiographic features of four areas of dysplasia in three patients were retrospectively investigated. RESULTS: Fourteen of 22 areas of dysplasia were shown on radiographs. Dysplasia in the rectum or sigmoid colon was depicted less frequently than that in other segments of the colon. Radiographic features were classified as obvious nodular protrusions (seven lesions), irregular mucosa (five lesions), or nodular protrusions with irregular mucosa (two lesions). Six of the seven areas of dysplasia shown as irregular mucosa were accompanied by minute spiculations in the margin of the colonic lumen. There was no correlation between radiologic features and histologic grade of dysplasia. CONCLUSION: Barium enema examination may be used as a complementary method of cancer surveillance with endoscopy. These methods show about two-thirds of lesions associated with dysplasia.
Adult↗
Natural history of superficial depressed colorectal cancer: retrospective radiographic and histologic analysis.
PURPOSE: To characterize the growth and developmental changes of superficial depressed colon cancer by using retrospective radiographic and histologic data. MATERIALS AND METHODS: In a retrospective study, the radiographs in patients with nine superficial depressed and those with 12 elevated (sessile or semipedunculated) colon cancers were analyzed. RESULTS: The initial superficial depressed lesions were 11.7 mm (mean) in diameter and took an average of 32.3 months to double in size. The initial elevated lesions were 15.7 mm (mean) in diameter and took an average of 8.6 months to double in size. The initial size of the former was not statistically significantly different from that of the latter; however, the doubling time of the superficial depressed cancers was statistically significantly slower than that of the elevated cancers. Superficial depressed cancers did not have concomitant adenomatous components, did not develop rapidly into advanced cancer, and did not change greatly from their original configuration; their growth rate was rather slow. Histologically, superficial depressed cancers showed a nonpolypoid growth pattern. CONCLUSION: Superficial depressed cancer develops more slowly than does elevated cancer, and this development follows a nonpolypoid growth pattern.
Adenocarcinoma↗
Effect of progesterone on aldosterone secretion in rats.
In both human and animal studies high progesterone states are associated with elevated aldosterone production but variable changes in PRA. These experiments were designed to test the hypothesis that progesterone has an effect similar to a low sodium diet on the glomerulosa cell: increasing aldosterone synthase messenger RNA activity and aldosterone production. Ovariectomized (OVX) rats were injected with progesterone (1 mg/100 g) or vehicle (SHAM) for 5 days. In a separate study, intact rats were placed on a low (0.02%) or high (1.6%) sodium diet for 5 days. On the day of death, rats were decapitated and blood collected for serum hormone determinations. Isolated adrenal glomerulosa cells were incubated +/- 10 nM angiotensin II (A II), after which aldosterone and corticosterone were measured. Early (conversion of cholesterol to pregnenolone) and late (conversion of corticosterone to aldosterone) aldosterone pathway activity was assessed in parallel incubates by adding cyanoketone and excess corticosterone with subsequent measurement of pregnenolone and aldosterone. In vivo, progesterone administration, like dietary sodium restriction, caused a significant increase in PRA (p < or = 0.043) and plasma aldosterone (p < or = 0.009), with no change in plasma corticosterone. Additionally, both treatments caused a significant increase in baseline (P < or = 0.01) and A II-stimulated (p < or = 0.027) aldosterone secretion in vitro. This increased responsiveness was secondary to activation of late pathway activity (p < or = 0.022) as determined by both an increased conversion of corticosterone to aldosterone and by an increase in messenger RNA levels of the late pathway enzyme aldosterone synthase. Thus, chronic progesterone administration apparently does not directly influence aldosterone secretion, but rather acts indirectly to increase aldosterone by mechanisms similar to sodium restriction.
Aldosterone↗
Primary jejunal malignant mixed tumor in a patient with von Recklinghausen neurofibromatosis.
A rare case of primary jejunal malignant mixed tumor arising in a 49-64-old Japanese male with von Recklinghausen's disease is reported. The patient, who had a past history of partial gastrectomy due to duodenal ulcer, was admitted with a complaint of epigastric pain. Upper gastrointestinal examinations showed a huge polypoid tumor located in the efferent loop of the gastrojejunostomy site. Because the tumor was strongly suggestive of leiomyosarcoma on histological examination of biopsy specimens, laparotomy was performed. The resected tumor measuring 10 X 7 X 7 cm was composed of adenocarcinoma admixed with various sarcomatous components, including rhabdomyosarcoma, osteosarcoma, and other sarcomas. Immunohistochemical analysis also supported this diagnosis. The features of this tumor closely resembled malignant mixed mullerian tumor of heterologous type that develops in female genital organs. It is well known that patients with von Recklinghausen neurofibromatosis have an increased incidence of mesenchymal tumors and malignant neoplasias, and therefore, it seems that there is a possible relationship between the histogenesis of this peculiar tumor and the genetic abnormality in this patient.
Humans↗
Bcl-2 expression in colorectal tumors: evidence of different pathways in sporadic and ulcerative-colitis-associated carcinomas.
Colorectal cancers (CRCs) differ in their age at presentation, distribution, histological features, and prognosis. If tumor biology reflects genetic events, these tumors might be expected to show differences in their genetic pathways. In this study, we investigated the role of Bcl-2 in the development of three different tumor groups. Using markers at eight different microsatellite locl, we characterized one group of 34 left-sided sporadic CRCs as replication error negative (RER-) and another group of 18 left-sided sporadic CRCs as replication error positive (RER+). These tumors, together with a third group of 22 left-sided ulcerative-colitis-associated CRCs (UCACRCs), were then examined by immunohistochemistry for Bcl-2 overexpression. Of 34 of the RER- tumors, 21 (62%) and 10 of 18 (56%) of the RER+ tumors were positive for Bcl-2 overexpression. In contrast, only 5 of 22 (23%) of the UCACRCs showed similar overexpression. Our results show a significantly lower frequency of Bcl-2 overexpression in UCACRCs as compared with sporadic CRCs (P < 0.005) but no difference between sporadic left-sided RER+ and RER- CRCs. These data provide additional evidence that UCACRCs may develop along a pathway that is different from that of sporadic CRCs.
Carcinoma↗