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排序方式: 共有321条查询结果,搜索用时 15 毫秒
1.
2.
S. Rosewicz E. O. Riecken Priv.-Doz. Dr. med B. Wiedenmann 《Journal of molecular medicine (Berlin, Germany)》1992,70(3-4):205-209
Summary Secretory vesicles of both the exocrine and the endocrine pancreas have been isolated and characterized in molecular terms from pancreatic tissue and primary cell cultures. Studies on pancreatic secretory processes could be further facilitated by the use of permanent cell lines that respond to secretory stimuli with a regulated secretory response. We now present biochemical, morphological and secretory studies on the rat pancreatic acinar cell line AR42J. This cell line is characterized by the presence of digestive enzyme-containing dense core vesicles, which are released in response to cholecystokinin. In addition, we present evidence that these cells also contain small neuroendocrine-specific vesicles, as evidenced by the expression of the neuroendocrine-specific vesicle proteins synaptophysin and S.V.2. Corresponding to these mixed exocrine-neuroendocrine features, we also found considerable amounts of the neurotransmitters glycine, glutamine and gammaaminobutyric acid (GABA), as well as the rate-limiting enzyme in GABA synthesis, glutamic acid decarboxylase (GAD) (EC 4.1.1.15) expressed in these cells. We demonstrated a specific uptake mechanism for radioactively-labelled GABA by these cells. In addition, GABA was released from intracellular storage pools by nicotinic receptor stimulation or membrane depolarization. In summary, AR42J cells represent the first amphicrine pancreatic cell line with the combined expression of exocrine and neuroendocrine secretory organelles, both of which follow a regulated secretory pathway in response to various secretory stimuli.Abbreviations DCV
dense core vesicles
- GABA
gammaaminobutyric acid
- SDS-PAGE
sodium dodecyl sulphate polyacrylamide gel electrophoresis 相似文献
3.
Stephan A. Wacker Franz Oswald Jörg Wiedenmann Walter Knöchel 《Developmental dynamics》2007,236(2):473-480
Lineage labeling is one of the most important techniques in developmental biology. Most recently, a set of photoactivatable fluorescent proteins originating from marine cnidarians became available. Here, we introduce the application of the green to red photoconvertible protein EosFP as a novel technique to analyze early vertebrate development. Both injection of EosFP mRNA and purified, recombinant EosFP followed by a light-driven green to red conversion allow lineage labeling in virtually any temporal and spatial dimension during embryonic development for at least 2 weeks. Specific staining of cells from nonsurface layers is greatly facilitated by light-driven conversion of EosFP compared with traditional methods. Therefore, green to red photoactivatable proteins promise to be a powerful tool with the potential to satisfy the increasing demand for methods enabling detailed phenotypical analyses after manipulations of morphogenetic events, gene expression, or signal transduction. 相似文献
4.
Escherichia coli Nissle 1917 distinctively modulates T-cell cycling and expansion via toll-like receptor 2 signaling 总被引:2,自引:0,他引:2
Sturm A Rilling K Baumgart DC Gargas K Abou-Ghazalé T Raupach B Eckert J Schumann RR Enders C Sonnenborn U Wiedenmann B Dignass AU 《Infection and immunity》2005,73(3):1452-1465
Although the probiotic Escherichia coli strain Nissle 1917 has been proven to be efficacious for the treatment of inflammatory bowel diseases, the underlying mechanisms of action still remain elusive. The aim of the present study was to analyze the effects of E. coli Nissle 1917 on cell cycling and apoptosis of peripheral blood and lamina propria T cells (PBT and LPT, respectively). Anti-CD3-stimulated PBT and LPT were treated with E. coli Nissle 1917-conditioned medium (E. coli Nissle 1917-CM) or heat-inactivated E. coli Nissle 1917. Cyclin B1, DNA content, and caspase 3 expression were measured by flow cytometry to assess cell cycle kinetics and apoptosis. Protein levels of several cell cycle and apoptosis modulators were determined by immunoblotting, and cytokine profiles were determined by cytometric bead array. E. coli Nissle 1917-CM inhibits cell cycling and expansion of peripheral blood but not mucosal T cells. Bacterial lipoproteins mimicked the effect of E. coli Nissle 1917-CM; in contrast, heat-inactivated E. coli Nissle 1917, lipopolysaccharide, or CpG DNA did not alter PBT cell cycling. E. coli Nissle 1917-CM decreased cyclin D2, B1, and retinoblastoma protein expression, contributing to the reduction of T-cell proliferation. E. coli Nissle 1917 significantly inhibited the expression of interleukin-2 (IL-2), tumor necrosis factor alpha, and gamma interferon but increased IL-10 production in PBT. Using Toll-like receptor 2 (TLR-2) knockout mice, we further demonstrate that the inhibition of PBT proliferation by E. coli Nissle 1917-CM is TLR-2 dependent. The differential reaction of circulating and tissue-bound T cells towards E. coli Nissle 1917 may explain the beneficial effect of E. coli Nissle 1917 in intestinal inflammation. E. coli Nissle 1917 may downregulate the expansion of newly recruited T cells into the mucosa and limit intestinal inflammation, while already activated tissue-bound T cells may eliminate deleterious antigens in order to maintain immunological homeostasis. 相似文献
5.
Synaptophysin expression in neuroendocrine neoplasms as determined by immunocytochemistry. 总被引:6,自引:3,他引:6 下载免费PDF全文
V. E. Gould B. Wiedenmann I. Lee K. Schwechheimer B. Dockhorn-Dworniczak J. A. Radosevich R. Moll W. W. Franke 《The American journal of pathology》1987,126(2):243-257
Synaptophysin is an integral membrane glycoprotein originally isolated from presynaptic vesicles of bovine neurons. The authors have studied a wide spectrum of neuroendocrine (NE) neoplasms by immunofluorescence microscopy on cryostat sections of freshly frozen tissues using a monoclonal antibody to this protein (SY 38). Without exception, they found the identical--or a very similar--protein expressed in all neuroblastomas, ganglioneuroblastomas, ganglioneuromas, pheochromocytomas, and paragangliomas studied. In these "neural" type NE neoplasms, synaptophysin was coexpressed with neurofilament proteins. Synaptophysin was also demonstrated in NE neoplasms of "epithelial" type in which it was predominantly coexpressed with cytokeratins and desmoplakin. It was invariably found in all variants of islet cell neoplasms and in all medullary thyroid carcinomas. Synaptophysin was also demonstrated in several adenomas of the hypophysis and parathyroids, in the majority of carcinoids of the bronchopulmonary and gastrointestinal tracts, and in many, though not all, NE carcinomas of the same sites, and of the skin. Conversely, SY 38 did not immunostain any of a large number of benign and malignant non-NE epithelial neoplasms; nor was any immunostaining obtained in a group of mesenchymal tumors. It is remarkable that SY 38 did not immunostain a number of malignant melanomas, including several that were immunostained for neuron-specific enolase (NSE) and several neuropeptides. Parallel studies conducted on conventionally fixed, paraffin-embedded tissue sections immunostained by the use of the avidin-biotin complex technique yielded very similar results. The findings indicate that synaptophysin is expressed in the whole range of NE neoplasms without detectable relation to the expression of other NE markers such as NSE, serotonin, and neuropeptides. Nor could the expression of synaptophysin by these tumors be correlated with their epithelial and/or neural cytoskeletal characteristics, their clinical aggressiveness, or the presence or absence of endocrinologic abnormalities. While the consistent expression of synaptophysin by the "neural" type of NE neoplasms would seem predictable its presence in diverse benign and malignant NE tumors of "epithelial" type is remarkable. It is concluded that synaptophysin is a significant as well as novel NE marker, and the use of antibody SY 38 as a broad range marker for the study and diagnosis of NE neoplasms is proposed. 相似文献
6.
Rindi G Paolotti D Fiocca R Wiedenmann B Henry JP Solcia E 《Virchows Archiv : an international journal of pathology》2000,436(3):217-223
The vesicular monoamine transporter 2 (VMAT2) facilitates the ATP-dependent accumulation of biogenic amine inside the secretory
granules of endocrine cells and neurons and was demonstrated in the histamine-producing enterochromaffin-like (ECL) cells
of the stomach. In the present investigation, VMAT2 immunohistochemistry was tested in 85 endocrine tumors, of which 60 were
well differentiated gastrointestinal and pancreatic growths, 5 poorly differentiated (neuro)endocrine carcinomas (PDEC) and
1 mixed PDEC/ECL cell carcinoma of the stomach, 12 pheochromocytomas/paragangliomas, 3 adrenocortical lesions, 2 parathyroid
and 2 lung neuroendocrine tumors. Extensive and intense VMAT2 immunoreactivity was observed in 16 of 16 gastric ECL cell tumors,
6 of 6 adrenal pheochromocytomas, 2 of 2 chromaffin paragangliomas and in 3 of the 4 carotid body paragangliomas investigated.
Rare VMAT2-positive cells were observed in 12 of 21 intestinal enterochromaffin (EC) cell tumors, in 9 of 11 pancreatic neuroendocrine
tumors, and in the mixed PDEC/ ECL cell carcinoma of the stomach (differentiated cells only). No VMAT2 immunoreactivity was
observed in five gastrin, four somatostatin and three enteroglucagon/peptideYY tumors of the gastrointestinal tract, in six
gastric PDECs, in three adrenocortical growths, and two parathyroid and two lung neuroendocrine tumors. These data support
VMAT2 immunohistochemistry as being a useful tool for the diagnosis of gastric ECL cell tumors, separating them from all other
endocrine tumors arising in the gastroduodenal area i.e., gastrin, somatostatin, EC cell and PDEC tumors, all of which proved
essentially negative.
Received: 28 June 1999 / Accepted: 20 October 1999 相似文献
7.
Synaptophysin: A reliable marker for medulloblastomas 总被引:4,自引:0,他引:4
K. Schwechheimer B. Wiedenmann W. W. Franke 《Virchows Archiv : an international journal of pathology》1987,411(1):53-59
Summary Synaptophysin is an acidic, integral membrane glycoprotein (Mr 38000) of presynaptic vesicles in various neurons and neuroendocrine cells, and in tumours derived from such cells. By indirect immunofluorescence microscopy of cryostat sections, using the monoclonal antibody SY 38 to synaptophysin, a consistent positive immunoreactivity was observed in all medulloblastomas (n= 6) and neuroblastomas (n=3) as well as a ganglioneuroma and a glioneuronal hamartoma. The presence of synaptophysin in medulloblastomas was confirmed biochemically by immunoblotting experiments. For purpose of comparison, the expression of intermediate-sized filament (IF) proteins was also examined. While neurofilament proteins were consistently expressed in the neuroblastomas (3/3), the ganglioneuroma and the glioneuronal hamartoma, IF distribution in medulloblastomas was variable. A neurofilament-positive type of tumour (1/6) could be distinguished from vimentin-expressing neoplasms (4/6) by immunocytochemistry. These data indicate that synaptophysin is a reliable marker for medulloblastomas as well as other differentiated and undifferentiated neuronal tumours and in this respect is superior to the more heterogeneous expression patterns of IF proteins in these tumours. 相似文献
8.
Sensitive and accurate quantitation of hepatitis B virus DNA using a kinetic fluorescence detection system (TaqMan PCR) 总被引:14,自引:0,他引:14
The laboratory diagnosis of hepatitis B virus (HBV) infection is based mainly on serological assays. Yet the detection and quantitation of viral DNA is necessary when addressing directly the question of infectivity or when monitoring the viral load during therapy. Standard hybridization assays allow for exact quantitation, but their sensitivity is limited to 10(5)-10(6) viral genomes per ml of serum. The most sensitive tests for HBV DNA are nested PCR systems, which recognize virtually one molecule of the target DNA per reaction. However, these assays only provide very coarse quantitative statements. To take advantage of both methods, a new assay for HBV DNA is described based on the commercial TaqMan system. This assay is capable of quantifying HBV DNA from the theoretical lower limit up to 10(10) genome equivalents per ml of serum and, thus, covers the complete range of naturally occurring states of infections. The method was calibrated on the basis of serial plasmid dilutions and compared with a well-established nested PCR system. More than 100 HBV positive sera and serial dilutions of the Eurohep standard for both ad and ay subtypes were analyzed. The assay reliably detected all HBV positive samples. It shows minimal run-to-run deviations, allows for quantitation that covers eight orders of magnitude, and finally, completely avoids the risk of cross-contamination by PCR products. Thus, this technique combines the sensitivity of PCR amplification and the quantitation potential of hybridization tests and it is time efficient and safer. 相似文献
9.
Andreas Josting Sabine Wiedenmann Jeremy Franklin Michael May Markus Sieber Juergen Wolf Andreas Engert Volker Diehl 《Journal of clinical oncology》2003,21(18):3440-3446
PURPOSE: To assess the incidence and outcome of secondary acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in patients with Hodgkin's disease (HD). PATIENTS AND METHODS: Between 1981 and 1998, the GHSG conducted three trial generations for early, intermediate, and advanced HD involving a total of 5,411 patients (called HD1 through HD9). RESULTS: A total of 46 patients with secondary AML/MDS were identified. The median age at diagnosis of leukemia was 47 years (range, 22 to 79 years). Primary therapy was as follows: radiotherapy alone (n = 4); doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD; n = 1); cyclophosphamide, vincristine, procarbazine, and prednisone (COPP)/ABVD or similar (n = 30); bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) baseline (n = 2); and BEACOPP escalated (n = 9). Twelve patients developed AML/MDS after salvage therapy, including four patients who developed AML/MDS after high-dose chemotherapy with autologous stem-cell transplantation. Thirty-six of the secondary malignancies were AML, and 10 malignancies were MDS. After a median observation time of 55 months, incidence of secondary AML/MDS was 1%. Treatment for secondary AML/MDS was as follows: cytarabine (Ara-C)-containing regimens (6-thioguanin, cytarabine, daunorubicin [TAD]/high-dose cytarabine, mitoxantrone [HAM], HAM, Ida-Ara-C (idarubicin + Ara-C), Ida-Flag (idarubicin, fludarabin, Ara-C, G-CSF), and idarubicin, cytarabine, etoposide [ICE]+HAM; n = 11), TAD-chemotherapy (n = 5), other regimens (n = 3), no treatment or supportive care (n = 24), palliative oral chemotherapy (n = 3), and allogeneic stem cell transplantation (n = 9). After 24 months of observation, no difference in freedom from treatment failure and overall survival (2% and 8%, respectively) was observed in patients who developed AML or MDS. CONCLUSION: The prognosis of patients with secondary AML/MDS after primary HD is poor. Thus, emphasis should be made to improve initial treatment in an attempt to prevent this complication. 相似文献
10.
Stage IV Gastro‐Entero‐Pancreatic Neuroendocrine Neoplasms: A Risk Score to Predict Clinical Outcome 下载免费PDF全文