327 research outputs found
Human HT-29 colon carcinoma cells contain mucarinic M receptors coupled to phosphoinositide metabolism
Five different musearlnie receptor subtypes ean be distinguished by the differenees in their amino aeid sequence, the eoupled signal transduetion system, pharmaeologieal binding properties and aetivation of ionie fluxes. The present study served to eharaeterize the binding profile of musearlnie receptors in human eolon eareinoma eells (HT-29) using seleetive musearlnie antagonists. The affinities of the compounds were eompared with their poteney to inhibit cholinergieally-aetivated phosphoinositide metabolism. Pirenzepine displaced [H]N-methyl-scopolamine binding and inhibited inositolphosphate (IP) release with potencies typieal of those of non-M receptors. The M subtype-selective antagonists sila-hexocyelium and hexahydro-sila-difenidol bad high affinity to the musearlnie reeeptors in HT-29 cells (K0 = 3.1 nM and 27 nM, respectively) and inhibited IP release at nanomolar concentrations. The M receptor antagonists, AF-DX 116 and methoctramine, had low antimusearinic poteneies. Our results demonstrate that HT-29 human colon earcinoma cells contain an apparently pure population of M receptors. These cells could serve as a model system for further investigations coneerning regulatory and signal transduction mechanisms associated with glandular muscarinic M receptors
Syntbesis and Properries of the Selective Antimuscarinic Agent Cyclohexylphenyl(3-piperidinopropyl)silanol
Die Synthese des selektiven Antimuskarinikums Cyclohexylpheny\{3-piperidinopropyl)sila· nol (1 b) wird beschrieben. 1 b wurde - ausgehend von (3·Chlorpropyl)trimethoxysilan - durch eine vierstufige Reaktionsfolge erhalten und als Hydrochlorid 2b mit einer Gesamtausbeute von etwa 45°/o isoliert. - 1 b ist aufgrund seiner großen pharmakologischen Se· lektivität zu einer Standardsubstanz in der experimentellen Pharmakologie bei der Differenzierung von Muskarinrezeptoren geworden.The synthesis of thc selective antimuscarinic agent cyclohexylphenyl(3-piperidinopropyl)silanol (1 b) is described. Starting with (3-chloropropyl)trimethoxysilane, I b was obtained by four reaction steps and isolated as hydrochloride 2b with a total yield of about 45°/o. - Because of its high pharmacological selectivity 1 b has become a reference drug in experimental pharmacology for the differentiation of muscarinic rcceptors
The significance of macrophage polarization subtypes for animal models of tissue fibrosis and human fibrotic diseases.
The systemic and organ-specific human fibrotic disorders collectively represent one of the most serious health problems world-wide causing a large proportion of the total world population mortality. The molecular pathways involved in their pathogenesis are complex and despite intensive investigations have not been fully elucidated. Whereas chronic inflammatory cell infiltration is universally present in fibrotic lesions, the central role of monocytes and macrophages as regulators of inflammation and fibrosis has only recently become apparent. However, the precise mechanisms involved in the contribution of monocytes/macrophages to the initiation, establishment, or progression of the fibrotic process remain largely unknown. Several monocyte and macrophage subpopulations have been identified, with certain phenotypes promoting inflammation whereas others display profibrotic effects. Given the unmet need for effective treatments for fibroproliferative diseases and the crucial regulatory role of monocyte/macrophage subpopulations in fibrogenesis, the development of therapeutic strategies that target specific monocyte/macrophage subpopulations has become increasingly attractive. We will provide here an overview of the current understanding of the role of monocyte/macrophage phenotype subpopulations in animal models of tissue fibrosis and in various systemic and organ-specific human fibrotic diseases. Furthermore, we will discuss recent approaches to the design of effective anti-fibrotic therapeutic interventions by targeting the phenotypic differences identified between the various monocyte and macrophage subpopulations
Y-box protein-1/p18 fragment identifies malignancies in patients with chronic liver disease
<p>Abstract</p> <p>Background</p> <p>Immunohistochemical detection of cold shock proteins is predictive for deleterious outcome in various malignant diseases. We recently described active secretion of a family member, denoted Y-box (YB) protein-1. We tested the clinical and diagnostic value of YB-1 protein fragment p18 (YB-1/p18) detection in blood for malignant diseases.</p> <p>Methods</p> <p>We used a novel monoclonal anti-YB-1 antibody to detect YB-1/p18 by immunoblotting in plasma samples of healthy volunteers (n = 33), patients with non-cancerous, mostly inflammatory diseases (n = 60), hepatocellular carcinoma (HCC; n = 25) and advanced solid tumors (n = 20). YB-1/p18 was then tested in 111 patients with chronic liver diseases, alongside established tumor markers and various diagnostic measures, during evaluation for potential liver transplantation.</p> <p>Results</p> <p>We developed a novel immunoblot to detect the 18 kD fragment of secreted YB-1 in human plasma (YB-1/p18) that contains the cold-shock domains (CSD) 1-3 of the full-length protein. YB-1/p18 was detected in 11/25 HCC and 16/20 advanced carcinomas compared to 0/33 healthy volunteers and 10/60 patients with non-cancerous diseases. In 111 patients with chronic liver disease, YB-1/p18 was detected in 20 samples. Its occurrence was not associated with advanced Child stages of liver cirrhosis or liver function. In this cohort, YB-1/p18 was not a good marker for HCC, but proved most powerful in detecting malignancies other than HCC (60% positive) with a lower rate of false-positive results compared to established tumor markers. Alpha-fetoprotein (AFP) was most sensitive in detecting HCC, but simultaneous assessment of AFP, CA19-9 and YB-1/p18 improved overall identification of HCC patients.</p> <p>Conclusions</p> <p>Plasma YB-1/p18 can identify patients with malignancies, independent of acute inflammation, renal impairment or liver dysfunction. The detection of YB-1/p18 in human plasma may have potential as a tumor marker for screening of high-risk populations, e.g. before organ transplantation, and should therefore be evaluated in larger prospective studies.</p
Detection of a gammaretrovirus, XMRV, in the human population: Open questions and implications for xenotransplantation
XMRV (xenotropic murine leukaemia virus-related virus) is a gammaretrovirus that has been detected in human patients with prostate carcinoma, chronic fatigue syndrome (CFS) and also in a small percentage of clinically healthy individuals. It is not yet clear whether the distribution of this virus is primarily limited to the USA or whether it is causally associated with human disease. If future investigations confirm a broad distribution of XMRV and its association with disease, this would have an impact on xenotransplantation of porcine tissues and organs. Xenotransplantation is currently being developed to compensate for the increasing shortage of human material for the treatment of tissue and organ failure but could result in the transmission of porcine pathogens. Maintenance of pathogen-free donor animals will dramatically reduce this risk, but some of the porcine endogenous retroviruses (PERVs) found in the genome of all pigs, can produce infectious virus and infect cultured human cells. PERVs are closely related to XMRV so it is critical to develop tests that discriminate between them. Since recombination can occur between viruses, and recombinants can exhibit synergism, recipients should be tested for XMRV before xenotransplantation
A bispecific diabody directed against prostate-specific membrane antigen and CD3 induces T-cell mediated lysis of prostate cancer cells
BACKGROUND: Although cancer of the prostate is one of the most commonly diagnosed cancers in men, no curative treatment currently exists after its progression beyond resectable boundaries. Therefore, new agents for targeted treatment strategies are needed. Cross-linking of tumor antigens with T-cell associated antigens by bispecific monoclonal antibodies have been shown to increase antigen-specific cytotoxicity in T-cells. Since the prostate-specific membrane antigen (PSMA) represents an excellent tumor target, immunotherapy with bispecific diabodies could be a promising novel treatment option for prostate cancer. METHODS: A heterodimeric diabody specific for human PSMA and the T-cell antigen CD3 was constructed from the DNA of anti-CD3 and anti-PSMA single chain Fv fragments (scFv). It was expressed in E. coli using a vector containing a bicistronic operon for co-secretion of the hybrid scFv V<sub>H</sub>CD3-V<sub>L</sub>PSMA and V<sub>H</sub>PSMA-V<sub>L</sub>CD3. The resulting PSMAxCD3 diabody was purified from the periplasmic extract by immobilized metal affinity chromatography (IMAC). The binding properties were tested on PSMA-expressing prostate cancer cells and PSMA-negative cell lines as well as on Jurkat cells by flow cytometry. For in vitro functional analysis, a cell viability test (WST) was used. For in vivo evaluation the diabody was applied together with human peripheral blood lymphocytes (PBL) in a C4-2 xenograft-SCID mouse model. RESULTS: By Blue Native gel electrophoresis, it could be shown that the PSMAxCD3 diabody is mainly a tetramer. Specific binding both to CD3-expressing Jurkat cells and PSMA-expressing C4-2 cells was shown by flow cytometry. In vitro, the diabody proved to be a potent agent for retargeting PBL to lyze C4-2 prostate cancer cells. Treatment of SCID mice inoculated with C4-2 tumor xenografts with the diabody and PBL efficiently inhibited tumor growth. CONCLUSIONS: The PSMAxCD3 diabody bears the potential for facilitating immunotherapy of prostate cancer and for the elimination of minimal residual disease
Elevated Flt3L predicts long-term survival in patients with high-grade gastroenteropancreatic neuroendocrine neoplasms
BACKGROUND: The clinical management of high-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) is challenging due to disease heterogeneity, illustrating the need for reliable biomarkers facilitating patient stratification and guiding treatment decisions. FMS-like tyrosine kinase 3 ligand (Flt3L) is emerging as a prognostic or predictive surrogate marker of host tumoral immune response and might enable the stratification of patients with otherwise comparable tumor features. METHODS: We evaluated Flt3L gene expression in tumor tissue as well as circulating Flt3L levels as potential biomarkers in a cohort of 54 patients with GEP-NEN. RESULTS: We detected a prominent induction of Flt3L gene expression in individual G2 and G3 NEN, but not in G1 neuroendocrine tumors (NET). Flt3L mRNA expression levels in tumor tissue predicted the disease-related survival of patients with highly proliferative G2 and G3 NEN more accurately than the conventional criteria of grading or NEC/NET differentiation. High level Flt3L mRNA expression was associated with the increased expression of genes related to immunogenic cell death, lymphocyte effector function and dendritic cell maturation, suggesting a less tolerogenic (more proinflammatory) phenotype of tumors with Flt3L induction. Importantly, circulating levels of Flt3L were also elevated in high grade NEN and correlated with patients' progression-free and disease-related survival, thereby reflecting the results observed in tumor tissue. CONCLUSIONS: We propose Flt3L as a prognostic biomarker for high grade GEP-NEN, harnessing its potential as a marker of an inflammatory tumor microenvironment. Flt3L measurements in serum, which can be easily be incorporated into clinical routine, should be further evaluated to guide patient stratification and treatment decisions
Закономерности микроструктурных изменений в титановом сплаве ВТ6 при деформации и наводороживании
Объектом исследования являются образцы титанового сплава марки ВТ6 прокатанные до различных степеней деформации методом механической прокатки. Исследование дефектной структуры проводилось с использованием методов позитронной спектроскопии, которые могут определять тип и концентрацию дефектов, а также химическое окружение данных дефектов. Однако, для получения количественной и качественной оценки количества дефектов методами позитронной спектроскопии необходима дополнительная информация о базовых дефектах и их влиянии на характеристики позитронной аннигиляции.
Целью работы является анализ структурных изменений в титановом сплаве ВТ6 в зависимости от степени холоднокатаной пластической деформации и после наводороживания.The object of the study are samples of titanium alloy grade VT6 rolled to various degrees of deformation by mechanical rolling. The study of the defect structure was carried out using positron spectroscopy methods, which can determine the type and concentration of defects, as well as the chemical environment of these defects. However, to obtain a quantitative and qualitative assessment of the number of defects by the methods of positron spectroscopy, additional information is needed about the basic defects and their effect on the positron annihilation characteristics.
The aim of the work is to analyze the structural changes in titanium alloy VT6, depending on the degree of cold-rolled plastic deformation and after hydrogenation
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VC1 catalyses a key step in the biosynthesis of vicine in faba bean
Faba bean (Vicia faba L.) is a widely adapted and high-yielding legume cultivated for its protein-rich seeds1. However, the seeds accumulate the pyrimidine glucosides vicine and convicine, which can cause haemolytic anaemia (favism) in 400 million genetically predisposed individuals2. Here, we use gene-to-metabolite correlations, gene mapping and genetic complementation to identify VC1 as a key enzyme in vicine and convicine biosynthesis. We demonstrate that VC1 has GTP cyclohydrolase II activity and that the purine GTP is a precursor of both vicine and convicine. Finally, we show that cultivars with low vicine and convicine levels carry an inactivating insertion in the coding sequence of VC1. Our results reveal an unexpected, purine rather than pyrimidine, biosynthetic origin for vicine and convicine and pave the way for the development of faba bean cultivars that are free of these anti-nutrients
Aspartoacylase-LacZ Knockin Mice: An Engineered Model of Canavan Disease
Canavan Disease (CD) is a recessive leukodystrophy caused by loss of function mutations in the gene encoding aspartoacylase (ASPA), an oligodendrocyte-enriched enzyme that hydrolyses N-acetylaspartate (NAA) to acetate and aspartate. The neurological phenotypes of different rodent models of CD vary considerably. Here we report on a novel targeted aspa mouse mutant expressing the bacterial β-Galactosidase (lacZ) gene under the control of the aspa regulatory elements. X-Gal staining in known ASPA expression domains confirms the integrity of the modified locus in heterozygous aspa lacZ-knockin (aspalacZ/+) mice. In addition, abundant ASPA expression was detected in Schwann cells. Homozygous (aspalacZ/lacZ) mutants are ASPA-deficient, show CD-like histopathology and moderate neurological impairment with behavioural deficits that are more pronounced in aspalacZ/lacZ males than females. Non-invasive ultrahigh field proton magnetic resonance spectroscopy revealed increased levels of NAA, myo-inositol and taurine in the aspalacZ/lacZ brain. Spongy degeneration was prominent in hippocampus, thalamus, brain stem, and cerebellum, whereas white matter of optic nerve and corpus callosum was spared. Intracellular vacuolisation in astrocytes coincides with axonal swellings in cerebellum and brain stem of aspalacZ/lacZ mutants indicating that astroglia may act as an osmolyte buffer in the aspa-deficient CNS. In summary, the aspalacZ mouse is an accurate model of CD and an important tool to identify novel aspects of its complex pathology
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