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R Porschen

Publications and source records attributed to R Porschen.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Prevention and early detection of colorectal carcinoma by endoscopic examinations].

People at average risk for colorectal cancer (asymptomatic, age > or = 45 years, no risk factors) are offered fecal occult blood testing each year and sigmoidoscopy every five years. In case of a positive fecal occult blood test, examination of the whole colon by colonoscopy should be performed. Colorectal cancer risk is significantly lowered by endoscopic polypectomy in patients with adenomas. After complete removal of adenomatous polyps a control colonoscopy is advised three years after the initial examination. People with a positive family history of colorectal cancer or adenomatous polyps, of inherited polyposis syndromes, of a hereditary non-polyposis colorectal cancer, after polypectomy, after resection of colorectal cancer and with inflammatory bowel disease possess an increased risk for the development of colorectal cancer. Surveillance recommendations in these cases are detailed. In order to increase the cost-benefit ratio in surveillance after curative resection of colorectal cancer the frequency of the surveillance procedures can be reduced. In patients with total or extensive ulcerative colitis colonoscopy with multiple biopsies should be performed after a disease duration of eight to ten years, further recommendations depend on the histopathologic results.

Aged↗
PubMed1997

Distribution of cell populations with DNA aneuploidy and p53 protein expression in ulcerative colitis.

OBJECTIVE: Patients with ulcerative colitis are at an increased risk for developing colorectal neoplasms. p53 mutations and the occurrence of DNA aneuploidies are common events in the development of sporadic colorectal neoplasias. This study tried to determine the frequency of these events during the development of colitis-associated colorectal neoplasms. DESIGN/METHODS: Four colectomy specimens with a total of 124 biopsies were investigated. DNA content was measured by flow cytometry and p53 protein expression was detected by immunohistochemistry. These results were correlated with histological findings. RESULTS: DNA aneuploidies were found in 58 (46.8%), and p53 protein expression in 30 samples (24.2%). The presence of DNA aneuploidy as well as of p53 protein expression correlated with the histological characteristics of neoplastic transformation. In areas without dysplasias or with indefinite dysplasias, 31.5% of the samples showed DNA aneuploidies and in about 9% of the samples p53 protein expression could be detected; 33.7% of samples without or with indefinite dysplasias showed p53 protein expression and/or DNA aneuploidies. CONCLUSION: These results show that the occurrence of DNA aneuploidies and nuclear p53 protein expression is a common event in the development of colitis-associated colorectal neoplasias. p53 protein expression seems to be an early event in this process. DNA aneuploidies occur even earlier and more frequently in the absence of p53 protein expression. Therefore, other genetic alterations besides p53 gene mutations might be involved in colitis-associated tumour development.

Adult↗
PubMed1997

[Argon plasma coagulation in endoscopic therapy of CREST syndrome associated upper gastrointestinal hemorrhage].

We report on the case of a 55-year-old patient suffering from progressive systemic sclerosis (PSS). The patient was sent to our department when clinical symptoms of an acute upper gastrointestinal hemorrhage occurred. Upper endoscopy showed a watermelon stomach and fresh blood in the stomach. The presence of teleangiectasias in the antrum could be proved histologically. Since the teleangiectasias found in the antrum were the only possible source of the hemorrhage three sessions of endoscopic argon plasma coagulation were performed. Macroscopically, a nearly complete disappearance of teleangiectasias could be achieved. After a follow-up of six months, there have been no clinical signs of another hemorrhage episode. This case shows that the existence of gastrointestinal teleangiectasias should be considered when chronic anemia or acute gastrointestinal hemorrhage occur in patients with PSS. Further it is demonstrated that even extended gastrointestinal teleangiectasias can be successfully treated by endoscopically performed argon plasma coagulation.

CREST Syndrome↗
PubMed1996

bcl-2 expression and prognosis in squamous-cell carcinomas of the esophagus.

The bcl-2 proto-oncogene is a known inhibitor of apoptosis and may be an important regulator of tumor growth. In the present study, bcl-2-protein expression was investigated by immunohistochemistry and correlated with prognosis in a series of 150 potentially curatively resected squamous-cell carcinomas of the esophagus. For comparison, bcl-2-protein expression was analyzed in normal esophageal mucosa, severe squamous dysplasias and carcinomas in situ. bcl-2 immunoreactivity was found in 40 out of 150 invasive squamous-cell carcinomas; the remaining carcinomas were completely negative. bcl-2-protein expression was found more frequently among poorly differentiated than among well-differentiated tumors (p < 0.0001). No correlation was found between bcl-2-protein expression and the parameters tumor size, depth of invasion and nodal status. Moreover, bcl-2-protein expression had no significant influence on overall survival. Whereas in normal mucosa bcl-2 immunoreactivity was restricted to the basal-cell layer, in 9 out of 15 severe squamous dysplasias and in 7 out of 14 carcinomas in situ bcl-2 staining was detected in all epithelial layers. Thus, bcl-2-protein is frequently expressed in invasive squamous-cell carcinomas of the esophagus and in precursor lesions of esophageal cancer, but has no significant impact on the outcome of esophageal cancer.

Adult↗
PubMed1996

The prognostic significance of DNA ploidy in adenocarcinomas of the esophagogastric junction.

DNA aneuploidy, as determined by flow cytometry, was detected in 36 out of 59 adenocarcinomas of the esophagogastric junction (61.0%). DNA aneuploidy was more frequent in tumors with infiltrative growth pattern and in high pT categories. No correlation was found with pN category, grading and Laurén's classification. In contrast to clinicopathological parameters, DNA ploidy has no impact on patients survival in univariate survival analysis.

Adenocarcinoma↗
PubMed1996

The prognostic significance of tumour cell proliferation in squamous cell carcinomas of the oesophagus.

Tumour samples from 150 patients with squamous cell carcinoma of the oesophagus were investigated immunohistochemically with the monoclonal antibody MIB-1, which recognises proliferating cells. Using light microscopy, the number of MIB-1-positive tumour cells was counted in the areas with the highest proliferative activity. The MIB-1 index was determined as the proportion of MIB-1-positive and MIB-1-negative tumour cells. A considerable variation of the MIB-1 indices was found between the different tumours with a minimum of 6% and a maximum of 95% (median, 33%). The MIB-1 index correlated significantly with the mitotic activity in the tumour tissue (r = 0.33; P = 0.0001) and with the proportion of apoptotic tumour cells (r = 0.25; P = 0.0017). No significant correlation was found between the MIB-1 index and various other prognostic parameters including pT classification, pN classification, tumour grade, blood vessel invasion and lymphatic vessel invasion. In the univariate survival analysis no significant difference was found between tumours with low (< or = 33%) and high MIB-1 index (> 33%) 5-year survival rate: low MIB-1 index, 19.2%; high MIB-1 index, 22.2%). In a Cox proportional hazard regression analysis only the parameters lymphatic vessel invasion (P = 0.0001), pT classification (P = 0.0034) and pN classification (P = 0.0256), but not the MIB-1 index, could be verified as independent prognostic variables. In conclusion, evaluation of the MIB-1 index does not provide prognostic information for oesophageal cancer patients.

Adult↗
PubMed1996

[Acute gastrointestinal side effects of radiotherapy. What is certain in the treatment?].

PURPOSE: Radiotherapy, especially in the abdominal region, is frequently associated with gastrointestinal side effects. METHODS: The article reviews the current knowledge about pathophysiological background, clinical symptoms and the treatment strategies of the major gastrointestinal side effects. RESULTS: Several basics are investigated and depending on this knowledge some special treatment strategies have been developed (5-HT3-receptor-antagonists in the treatment of nausea, Figure 1, Table 2). The treatment of stomatitis, esophagitis, enteritis and proctitis still remains symptomatic and is not yet standardized (Tables 3 to 6). There are some promising results with smectit (enteritis) and sucralfat. Special dental attendance should be performed before initiating radiotherapy of the head and neck region. Technical improvement in radiotherapy will also help to reduce side effects. CONCLUSION: In order to minimize gastrointestinal side effects, it is necessary to further investigate the pathophysiology of acute and late toxicity.

Abdominal Neoplasms↗
PubMed1996

Fluorescence techniques for diagnosing intestinal microsporidiosis in stool, enteric fluid, and biopsy specimens from acquired immunodeficiency syndrome patients with chronic diarrhea.

OBJECTIVE: To evaluate three fluorescent chitin stains for detecting microsporidia spores in specimens from acquired immunodeficiency syndrome (AIDS) patients with chronic diarrhea. METHODS: We compared the Fungifluor, Calcofluor White, and Fungiqual A fluorochrome stains for identifying Enterocytozoon bieneusi and Septata intestinalis spores in stool, intestinal fluid, biopsy imprints, and paraffin biopsy sections. The modified chromotrope trichrome stain was used as the standard light microscopic technique for stool and fluid specimens. Stained and unstained paraffin sections and fluid preparations were also evaluated. Multiple specimens from 50 consecutive symptomatic AIDS patients and archival material from known microsporidia-positive AIDS patients were analyzed. RESULTS: Spores of E bieneusi and S intestinalis fluoresce brightly with all three fluorochrome stains in all of the types of diagnostic specimens. Fluorescing debris and the much larger fungal forms were readily distinguished. Spores were equally well detected in unfixed and formalin-fixed stool specimens, but were not as well detected after sodium acetate-acetic acid, polyvinyl acetate, and ethanol fixation. Bouin's tissue fixative gave a higher background staining than formalin. Spores were readily detected in archival paraffin sections and stool preparations, even when the specimens had been stained previously. Repeat fluorochrome staining was possible. The methods also could detect extraintestinal parasites in paraffin sections. CONCLUSION: The three fluorescent chitin stains are sensitive and rapid methods for detecting microsporidia spores in stool, intestinal fluid, biopsy imprint, and tissue specimens, even from archived material.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Prognostic value of histopathologic parameters of esophageal squamous cell carcinoma.

BACKGROUND: The grading of squamous cell carcinoma (SCC) of the esophagus as proposed by the World Health Organization (WHO) has not yet proved to be prognostically significant. Therefore, the prognostic impact of various histologic parameters was investigated and compared with that of the WHO grading. METHODS: Hematoxylin and eosin-stained tumor samples from 138 patients with SCC of the esophagus who underwent potentially curative resection (no residual tumor or distant metastases) were evaluated for the following histologic parameters: degree of keratinization, nuclear polymorphism, pattern of invasion, mitotic activity, and inflammatory response. The prognostic impact of these parameters was analyzed by univariate and multivariate survival analyses. RESULTS: In the univariate analysis, the inflammatory response (P = 0.0006), pattern of invasion (P = 0.0011), and nuclear polymorphism (P = 0.0161) were the only parameters that correlated with survival. However, in a multivariate survival analysis including these parameters, only pattern of invasion (P = 0.0010) and inflammatory response (P = 0.0076) were prognostically significant. Based on these results, a new prognostic score system was defined that correlated significantly with survival in the univariate survival analysis (P = 0.0002). In contrast, the WHO histologic grade was not prognostically significant. In the multivariate Cox regression analysis, the new prognostic score system proved to be an independent prognostic parameter (P = 0.0062), ranking next to pT classification (P = 0.0001) and pN classification (P = 0.0014). CONCLUSIONS: For SCC of the esophagus, histologic grading based on pattern of invasion and inflammatory response had an independent prognostic impact, whereas the grading system proposed by the WHO had no significant prognostic value.

Adult↗
PubMed1995

Incidence and prognostic significance of vascular and neural invasion in squamous cell carcinomas of the esophagus.

The prognostic influence of blood-vessel invasion (BVI), lymphatic-vessel invasion (LVI) and neural invasion (NI) was evaluated retrospectively in a series of 161 patients with squamous cell carcinoma (SCC) of the esophagus who underwent esophageal resection. Evidence of BVI, LVI and NI was found in 32.9%, 48.5% and 26.1%, respectively. Incidence of BVI, LVI and NI was significantly higher in high pT categories (pT3 and pT4) than in low pT categories (pT1 and pT2) and in patients with distant metastases than in patients without distant metastases. Incidence of LVI and NI in lymph-node-positive patients was significantly higher than in lymph-node-negative patients. The 5-year survival rate was significantly lower in patients with BVI or LVI than in patients without BVI or LVI. Patients with evidence of NI showed no significant differences in 5-year survival from patients without evidence of NI. By stepwise multivariate Cox regression analysis, BVI and LVI were shown to be independent prognostic factors. A search for vascular invasion may therefore provide additional prognostic precision in SCC of the esophagus.

Carcinoma, Squamous Cell↗
PubMed1995

Achalasia-associated squamous cell carcinoma of the esophagus: flow-cytometric and histological evaluation.

Although the risk of cancer is increased in patients with achalasia, biomarkers of an increased cancer risk have not been evaluated. In an esophagectomy specimen of a patient with achalasia-associated squamous cell carcinoma, normal mucosal and carcinomatous samples were systematically taken for flow cytometry and histology. The distribution of DNA aneuploidy and dysplasia was mapped within the resected specimen. Four of 10 tumor samples and 4 of 16 normal mucosal samples of the esophagus showed additional aneuploid stem lines. Gastric mucosa only showed diploid DNA histograms. S-phase fraction in normal esophageal samples (7.8% +/- 1.1%) was lower than in dysplastic and carcinomatous samples (8.8% +/- 2.4%; P = NS). Areas of mild to moderate dysplasia were detected in the esophageal mucosa adjacent to the neoplasm. This report shows the potential applicability of flow cytometry in the surveillance of patients with achalasia. However, prospective endoscopic studies with long follow-up periods are required before flow cytometric and histological parameters can be used as biomarkers of an increased cancer risk in achalasia.

Carcinoma, Squamous Cell↗