Schwannoma of the greater superficial petrosal nerve.
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Adult↗
Biomedical subjects
M Wagner
Publications and source records attributed to M Wagner.
Replicative senescence of human primary cells--molecules and mechanisms.
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Cell Cycle Proteins↗
Molecular evidence for genus level diversity of bacteria capable of catalyzing anaerobic ammonium oxidation.
Recently, a bacterium capable to oxidize ammonium anaerobically at a high rate was identified as novel member of the Planctomycetales (Strous, M., Fuersi, J. A., Kramer, E. H. M., Logemann, S., Muyzer, G., van de Pas-Schoonen, K. T., Webb, R. I., Kufnen, J. G., and Jetten, M. S. M.: Nature 400, 446-449, 1999). Here we investigated the microbial community structure of a trickling filter biofilm with a high anaerobic ammonium oxidation activity. Fluorescence in situ hybridization (FISH) with a set of nine probes designed for specific identification of the recently described anaerobic ammonium oxidizer demonstrated that only one probe hybridized to bacteria within the biofilm. For phylogenetic characterization of putative biofilm anaerobic ammonium oxidizers a full-cycle 16S rDNA approach was performed by using a Planctomycetales-specific forward primer for PCR amplification. Of the twenty-five 16S rDNA fragments (1364 bp in length) amplified from the biofilm, nine were affiliated to the Planctomycetales. Comparative analysis showed that these sequences were more than 98.9% similar to each other but only distantly related to the previously recognized anaerobic ammonium oxidizer (below 91% similarity) and all other organisms represented in public 16S rRNA databases (similarities of below 79%). The retrieved sequences and the previously recognized anaerobic ammonium oxidizer represent two well-separated groups of a deep-branching lineage within the Planctomycetales. Quantitative FISH analysis with a newly designed specific probe showed that the novel bacterium, provisionally classified as "Candidatus Kuenenia stuttgartiensis" constituted the dominant fraction of the biofilm bacteria. In situ probing revealed that ammonia-oxidizing bacteria of the beta-subclass of Proteobacteria were also present, albeit in significant smaller amounts, within the anoxic biofilm. Comparative sequence analysis of a stretch of the gene encoding ammonia-monooxygenase (amoA) demonstrated the occurrence of the DNA of at least three different populations of beta-subclass ammonia oxidizers within the biofilm.
Anaerobiosis↗
Human herpesvirus type 8 in salivary gland tumors.
BACKGROUND: The new human herpesvirus type 8 (HHV-8) has been detected in all types of Kaposi's sarcomas, as well as in body-cavity lymphomas and Castleman's disease, furthermore molecular biologic studies have identified a number of potential viral oncogenes. There is evidence for sexual transmission of HHV-8 in HIV-seropositive patients, but the route of infection among the HIV-seronegative population is uncertain. Findings of HHV-8 DNA in saliva in some cases are suggestive of nonsexual transmission associated with latent infection of the salivary gland (as it is known for EBV, CMV, HHV-6 and HHV-7). OBJECTIVE: As little is known about the etiological factors of salivary gland tumors and to give more insights into HHV-8 cell tropism normal salivary gland tissue (n=12) and different salivary glands neoplasm (n=58) were tested for HHV-8 sequences and antigens in HIV-seronegative patients. STUDY DESIGN: Biopsies of both normal salivary gland and tumors were investigated for HHV-8 sequences. A nested-PCR method was used for amplification of HHV-8 DNA fragments and the nature of the amplification products was confirmed by Southern blot hybridization. In addition, we used an in situ hybridization technique and immunohistochemical staining for detection of HHV-8 infected cells. The sera of the respective patients were tested for anti-HHV-8 antibodies using commercial IFA and an ELISA-assay. RESULTS: HHV-8 DNA sequences could be detected in one bilateral MALT-lymphoma of the parotid gland of a HHV-8 seropositive female patient suffering from Sjögren's syndrome (SS). The remaining parotid samples did neither show HHV-8 sequences nor HHV-8 antigens. Using above assays only one additional patient was seropositive for HHV-8. CONCLUSION: Our data suggest that HHV-8 does not usually infect the salivary gland in HIV-seronegative patients and does not seem to play a pathogenic role in vascular and epithelial salivary gland neoplasm. Pathogenic role of HHV-8 in Sjögren's syndrome associated MALT-lymphoma remains unclear and should be subject of further studies.
Adult↗
Epidemiologic application of pulsed-field gel electrophoresis to an outbreak of Campylobacter jejuni in an Austrian youth centre.
We report the first documented Campylobacter jejuni outbreak in an Austrian youth centre. Sixty-four children were involved of which 38 showed classical signs of campylobacter gastroenteritis. Since unpasteurized milk distributed by a local dairy was suspected to be the source of infection, stool samples were collected from 20 cows providing the milk. Five of the cows tested positive for C. jejuni. These isolates together with 37 clinical samples were compared by pulsed-field-gel electrophoresis (PFGE). The PFGE patterns, using the restriction endonucleases SmaI and SalI, were identical for the human and bovine isolates. This finding confirmed that the outbreak was caused by the consumption of unpasteurized milk contaminated with C. jejuni.
Adolescent↗
Cepaea hortensis agglutinin-I, specific for O-glycosidically linked sialic acids, selectively labels endothelial cells of distinct vascular beds.
The lectin Cepaea hortensis agglutinin-I (CHA-I) binds to O-glycosidically linked sialic acids with previously characterized specificity. Employing histochemistry, we demonstrate that CHA-I is a useful probe for detecting sialic acids in formalin-fixed human tissues in a specific manner. It stains the endothelium of arteries and veins in all tissues examined, and labels the capillaries in distinct vascular beds including the brain, colon, thyroid, pituitary, and adrenal. By contrast, the endothelial sinusoids in the liver, spleen, and bone marrow remained unstained. The staining pattern of CHA-I overlaps with the distribution of the sialomucin and L-selectin ligand podocalyxin, which includes positivity of podocytes and interstitial but not glomerular capillaries. CHA-I-positive epithelial structures were found in the lung, liver and kidney. Colon carcinoma cells were labelled with CHA-I but not haemangiosarcomas. In summary, CHA-I is a useful tool for detecting O-glycosidically linked sialic acids in formalin-fixed tissues, and a potentially powerful tool for the isolation and characterization of unknown sialomucins in normal and eventually in diseased tissues.
Animals↗
A new quantitative test method for cell proliferation based on detection of the Ki-67 protein.
A quantitative method to assess cell proliferation is one essential prerequisite for testing biomaterial cytocompatibility in vitro. Currently used methods, e.g. bromodeoxyuridine incorporation, show serious disadvantages concerning either sensitivity, specificity or handling. A new enzyme linked immunosorbent assay (ELISA) system for the quantification of cell proliferation based on detection of the Ki-67 protein is described. This protein has turned out to be strictly correlated with the active parts of the cell cycle but to be absent in G0. The measurement of Ki-67 expression by different human cell types, e.g. endothelial cells and HeLa cells, was evaluated in order to answer the question of whether the data obtained using the Ki-67 ELISA method correlate with the proliferation measured with flow cytometrical DNA analysis and microscopical evaluation. Methods currently used for the evaluation of cell proliferation were compared to the new Ki-67 ELISA method. In addition, the functionality of adherent endothelial cells, and the viability and morphology of the cells were investigated. Cells were treated with standard culture medium with or without the transcription inhibitor, actinomycin D, or growth factors, e.g. endothelial cell growth factor (ECGF), and were exposed to metal ion standard solutions. These solutions were in a cytotoxic-non-cytotoxic range. Ki-67 ELISA was found to be a reliable quantitative method to assess proliferation of cultured human cells in vitro. It has advantages over methods that are currently being used. It is easy to perform and corresponds to the requirements for a test to be selected for biomaterial testing according to ISO standard 10 993.
Journal Article↗
[Surgery of pancreatic carcinoma].
Pancreatic cancer is the third leading neoplasm of the gastrointestinal system and has a dismal prognosis. The majority of patients are no more suitable for resection at time of diagnosis due to early development of distant metastases or major infiltration of adjacent structures. However, due to the resistance of pancreatic cancer against radiation and chemotherapy, radical resection represents the only therapy with a potential for cure. For the surgical treatment of pancreatic head cancer, the classical Whipple operation is still the standard procedure but during the last two decades, pylorus-preserving pancreatoduodenectomy has been evolved as a more conservative procedure in order to omit the consequences of partial gastrectomy. For cancer of the pancreatic body and tail, distal pancreatectomy or total pancreatectomy represent the current standard treatment. More radical methods like regional pancreatectomy and resection with extended lymph node dissection have failed so far to demonstrate any improvements in long-term survival compared to the standard types of resection. To further improve the treatment of pancreatic cancer, prospectively randomized trials are needed to compare extended surgical procedures with the standard types of resection and the efficiency of various adjuvant therapies.
Adult↗
[Pylorus preserving or classical Whipple operation in tumors. Initial clinical results of a prospective randomized study].
UNLABELLED: During the last decades, the classical Whipple resection (cWhipple) and pylorus-preserving Whipple (ppWhipple) operation have been evolved for the resection of cancer of the pancreatic head. However no definitive answer exists whether the more conservative ppWhipple indeed equalizes the short and long term results of the cWhipple procedure. METHODS: Therefore we conducted a randomized prospective trial in a non-selected, consecutive patient series. All relevant data concerning patient's demographics, intraoperative and histological findings as well as postoperative mortality morbidity and follow-up after discharge were analyzed. RESULTS: From 6/96 to 10/99 139 patients with suspicion of pancreatic or periampullary tumor were prospectively randomized to undergo either a cWhipple or a ppWhipple (intention to treat). Based on the inclusion and exclusion criteria, 93 of these patients were finally analyzed in the study. There were 51 cWhipple and 42 ppWhipple resections. There were no differences concerning age, sex, ASA classification, tumor type and stage, length of ICU- and in-hospital stay. However, the ppWhipple group had a significant shorter operation time. There was no difference in mortality and morbidity. The incidence of delayed gastric emptying was identical in both groups. For long-term follow-up, a total of 76 patients with histological proven pancreatic or periampullary carcinoma were analyzed. There was no difference in tumor recurrence and in long-term survival after a median follow-up of 1.5 years (0.1-3.5). CONCLUSION: Our intermediate results demonstrate that cWhipple and ppWhipple are equally radical. However, ppWhipple may be the procedure of choice for the treatment of pancreatic and periampullary cancer.
Adenocarcinoma↗
[Stent or surgical bypass as palliative therapy in obstructive jaundice].
UNLABELLED: During the last decades, the mortality following pancreatic resections has decreased tremendously due to advances in operative technique and perioperative management. In order to examine if similar improvements have been achieved for surgical palliation of obstructive jaundice, we conducted an analysis of our series of surgical bypass procedures. METHODS: Data from all patients undergoing surgical palliation after exploration for pancreatic carcinoma, were prospectively recorded. RESULTS: Between 1.11.93 to 1.11.99 a total of 348 patients were treated with a tumor of the pancreas. 74 of these patients received a bypass procedure: there were 40 double bypass, 20 biliary and 14 gastric bypass procedures. Overall morbidity and mortality was 35% and 1.2% respectively. Median in-hospital stay was 12 days (range 6-37). Median survival time was 5 months (range 1-25). Neither the type of surgical palliation, age nor perioperative risk assessment according to the ASA classification affected perioperative mortality. In contrast, jaundiced patients had significantly more postoperative complications than non-jaundiced patients (58% versus 18%; p = 0.001). CONCLUSIONS: Surgical palliation can nowadays be performed with great safety. A double bypass procedure consisting of a hepatojejunostomy combined with a gastrojejunostomy seems to be the procedure of choice for patients with unresectable pancreatic carcinoma.
Adult↗
Evidence for a protein related immunologically to the jaagsiekte sheep retrovirus in some human lung tumours.
Human bronchioloalveolar carcinoma (BAC) is a lung cancer, morphologically similar to an endemic contagious lung neoplasm of sheep called sheep pulmonary adenomatosis (SPA) or jaagsiekte. SPA is caused by an exogenous type B/D retrovirus (jaagsiekte sheep retrovirus (JSRV)), which prompted the present study to obtain evidence of a retrovirus in BAC. A panel of 249 human lung tumours, 21 nontumour lung lesions, four normal lung tissues, 23 adenocarcinomas from other organs and a cell line expressing a human endogenous retrovirus protein was examined immunohistochemically using a rabbit antiserum directed against the JSRV capsid protein. Specific staining was detected only in the cytoplasm of recognizably neoplastic cells in the pulmonary alveoli of 39 of 129 (30%) BACs, 17 of 65 (26%) lung adenocarcinomas and two of seven large cell carcinomas. The remaining samples were negative. These results support the hypothesis that some human pulmonary tumours may be associated with a jaagsiekte sheep retrovirus-related retrovirus, warranting further studies.
Adenocarcinoma↗
Oestrogenic steroids and melanoma cell interaction with adjacent skin cells influence invasion of melanoma cells in vitro.
The invasion of melanoma is complex and multi-staged and involves changes in both cell/extracellular matrix (ECM) and cell/cell interactions. Female steroids and alpha-MSH have also been reported to influence metastatic melanoma progression, but their mechanisms of action are unknown. Accordingly, our aim was to establish in vitro models to examine (a) the influence of sex steroids and alpha-melanocyte-stimulating hormone (alpha-MSH) on tumour invasion and the influence of (b) ECM proteins and (c) adjacent cells on melanoma invasion. In the first model, melanoma cell invasion through fibronectin over 20 hr under serum-free conditions was used to investigate the effects of 17beta-oestradiol and oestrone on the invasion of human melanoma cell lines, A375-SM and HBL. A375-SM, but not HBL cells, proved very susceptible to inhibition by female steroids. However, invasion of the HBL line was inhibited by alpha-MSH. Using the second model of reconstructed human skin based on de-epidermised acellular dermis, we found that the HBL cells on their own failed to invade into the dermis (irrespective of the presence or absence of the basement membrane). However, there was a significant synergistic interaction between keratinocytes, fibroblasts and HBL cells, such that a modest invasion of HBLs into the dermis was seen within 2 weeks when other skin cells were present. In contrast, A375-SM cells showed a significant ability to invade the dermis in the absence of other cells, with less invasion when other skin cells were present. In summary, these models have provided new information on the extent to which melanoma cell invasion is sensitive to oestrogenic steroids and to alpha-MSH and to interaction, not only with adjacent skin cells but also to the presence of basement membrane antigens.
Estradiol↗
Characterization of an in vitro model of human melanoma invasion based on reconstructed human skin.
The purpose of this study was to compare the invasive properties of normal human cutaneous melanocytes and of a cutaneous melanoma cell line (HBL) in a three-dimensional model of reconstructed human skin. Specifically, we asked to what extent the pigmentary and invasive behaviour of both cells is influenced by their interaction with adjacent skin cells (keratinocytes and fibroblasts) and the basement membrane (BM). In the presence of a BM, normal human melanocytes within this model remained within the basal layer of keratinocytes and did not pigment spontaneously. When the BM was removed, melanocytes were found suprabasally and pigmented extensively. No significant invasion of melanocytes into the dermis was detected in the presence or absence of the BM. HBL melanoma cells showed no significant ability to invade into the dermis in the absence of other cells, irrespective of the presence or absence of the BM. However, when added to keratinocytes and fibroblasts, HBL cells showed a capacity to invade into the dermis, both in the presence and absence of the BM. Associated with HBL invasion into the dermis, we noted significant keratinocyte entry into the dermis. On their own, keratinocytes entered the dermis in the absence of the BM but showed no significant penetration into the dermis when the BM was present. In summary, this model demonstrates clear differences between melanocytes and a melanoma cell line with respect to their invasive properties. It also allows demonstration of interactions between cells, and between cells and the BM. The study also provides evidence for a synergistic interaction between this melanoma cell line and keratinocytes in penetrating the BM.
Basement Membrane↗
Pancreatic fistula after pancreatic head resection.
BACKGROUND: Pancreatic resections can be performed with great safety. However, the morbidity rate is reported to be 40-60 per cent with a high prevalence of pancreatic complications. The aim of this study was to analyse complications after pancreatic head resection, with particular attention to morbidity and pancreatic fistula. METHODS: From November 1993 to May 1999, perioperative and postoperative data from 331 consecutive patients undergoing pancreatic head resection were recorded prospectively. Data were analysed and grouped according to the procedure performed: classic Whipple resection, pylorus-preserving pancreatoduodenectomy (PPPD) or duodenum-preserving pancreatic head resection (DPPHR). RESULTS: Pancreatic head resection had a mortality rate of 2.1 per cent; the difference in mortality rate between the three groups (0.9-3.0 per cent) was not significant. Total and local morbidity rates were 38.4 and 28 per cent respectively. DPPHR had a lower morbidity, both local and systemic, than pancreatoduodenectomy. The prevalence of pancreatic fistula was 2.1 per cent in 331 patients, and was not dependent on the procedure or the aetiology of the disease. Reoperations were performed in 3.9 per cent of patients, predominantly for bleeding and non-pancreatic fistula. None of the patients with pancreatic fistula required reoperation or died in the postoperative course. CONCLUSION: A standardized technique and a continuing effort to improve perioperative management may be responsible for low mortality and surgical morbidity rates after pancreatic head resection. Pancreatic complications occur with Whipple, PPPD and DPPHR procedures with a similar prevalence. Pancreatic fistula no longer seems to be a major problem after pancreatic head resection and rarely necessitates surgical treatment.
Adolescent↗
Ultrastructural changes of human cardiac atrial nerve endings in diabetes mellitus.
BACKGROUND: Autonomic neuropathy resulting from long-term diabetes mellitus may affect heart innervation. However, so far diabetes induced morphological changes of cardiac nerves are not well-known. In this study human cardiac atrial tissue from diabetic patients was analysed by electron microscopy for structural alterations as a result of diabetic neuropathy. METHODS: In coronary bypass surgery, an edge of the right auricle was routinely resected for reason of extracorporal circulation. Thin cardiac tissue sections of 100 nm were studied by electron microscopy. Atrial tissue samples were collected from 5 patients with long-standing diabetes (for at least 8 years) and compared to atrial tissue samples from 5 patients without diabetes, equally undergoing coronary bypass surgery. RESULTS: In all atria-free nerve endings with unmyelinized, axons were observed. Cross sections of 479 axons from diabetic patients were compared to 419 axons of nondiabetic patients. The number of altered axons was significantly higher in cardiac tissue of diabetic patients (32%) in comparison to normal subjects (17%). In diabetic patients, 20% of the intra-axonal mitochondria were condensed or hydropic, whereas in nondiabetic patients only 4% of the mitochondria were altered. Membrane fragments were present in 21% of the axons in atria of diabetic patients compared to 10% in nondiabetic subjects. Only in cardiac axons from diabetic patients there were lamellar bodies, dissolved axoplasma and junctions between neighbouring axons in a minor number. Few vacuoles were present in axons of both groups. CONCLUSION: In myocardial atrial-free nerve fibre bundles of diabetic patients, the amount of degenerative changes was higher in comparison to atrial cardiac tissue from nondiabetic subjects. These morphological alterations may indicate manifestation of diabetic neuropathy and might contribute to the impairment of autonomic neural control affecting the heart in long-standing diabetes mellitus.
Aged↗
Ecological study of a bioaugmentation failure.
A nitrifying sequencing batch reactor was inoculated twice with the aerobic denitrifying bacterium Microvirgula aerodenitrificans and fed with acetate. No improvement was obtained on nitrogen removal. The second more massive inoculation was even followed by a nitrification breakdown, while at the same time, nitrification remained stable in a second reactor operated under the same conditions without bioaugmentation. Fluorescent in situ hybridization with rRNA-targeted probes revealed that the added bacteria almost disappeared from the reactor within 2 days, and that digestive vacuoles of protozoa gave strong hybridization signals with the M. aerodenitrificans-specific probe. An overgrowth of protozoa, coincident with the disappearance of free-living bacteria, was monitored by radioactive dot-blot hybridization only in the bioaugmented reactor. Population dynamics were analysed with a newly developed in situ quantification procedure of the probe-targeted bacteria. The nitrifying groups of bacteria decreased in a similar way in the bioaugmented and non-bioaugmented reactors. Other bacterial groups evolved differently. The involvement of different ecological parameters are discussed separately for each reactor. These results underline the importance of predator-prey interaction and illustrate the undesirable effects of massive bioaugmentation.
Animals↗
Rosacea and Helicobacter pylori: interference of systemic antibiotic in the study of possible association.
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Adult↗
Human herpesvirus type 8 in HIV-infected patients with interstitial pneumonitis.
OBJECTIVES: The new human herpesvirus type 8 (HHV-8) has been detected in all types of Kaposi's sarcomas, as well as in body-cavity lymphomas and Castleman's disease. Recently, HHV-8 has also been associated with encephalitis in HIV-positive and HIV-negative patients. Interstitial pneumonitis, combined with detection of HHV-8 in non HIV-infected patients, indicates a pathogenetic role of HHV-8 in unexplained lung diseases. We have studied two HIV-infected patients, with otherwise unexplained interstitial pneumonitis for the presence of HHV-8. METHODS: Lung biopsies of both patients were investigated for HHV-8 sequences. A nested PCR method was used for amplification of HHV-8 DNA fragments, and the nature of the amplification products was confirmed by Southern blot hybridization. In addition, we used an in situ hybridization technique and immunohistochemical staining for detection of HHV-8 infected cells. RESULTS: Amplification of HHV-8 DNA fragments was seen with template DNA from lung biopsies of both cases and the appropriate positive controls, but not with negative controls. In situ hybridization and immunohistochemical staining demonstrated HHV-8 infected lymphoid cells and alveolar macrophages in both patients as well. CONCLUSIONS: HHV-8 was found in HIV-infected patients with otherwise unexplained interstitial pneumonitis, but the pathogenic role of HHV-8 in patients with interstitial pneumonia remains unclear.
Adult↗