60 research outputs found
Adaptive Logics as a Necessary Tool for Relative Rationality: Including a Section on Logical Pluralism
In this paper, I show that adaptive logics are required by my epistemological stand. While doing so, I defy the reader to cope with the problems I am able to cope with. The last section of the paper contains a defense of a specific form of logical pluralism. Although this section is an integral part of the paper, it may be read separately
MIP/Aquaporin 0 Represents a Direct Transcriptional Target of PITX3 in the Developing Lens
The PITX3 bicoid-type homeodomain transcription factor plays an important role in lens development in vertebrates. PITX3 deficiency results in a spectrum of phenotypes from isolated cataracts to microphthalmia in humans, and lens degeneration in mice and zebrafish. While identification of downstream targets of PITX3 is vital for understanding the mechanisms of normal ocular development and human disease, these targets remain largely unknown. To isolate genes that are directly regulated by PITX3, we performed a search for genomic sequences that contain evolutionarily conserved bicoid/PITX3 binding sites and are located in the proximity of known genes. Two bicoid sites that are conserved from zebrafish to human were identified within the human promoter of the major intrinsic protein of lens fiber, MIP/AQP0. MIP/AQP0 deficiency was previously shown to be associated with lens defects in humans and mice. We demonstrate by both chromatin immunoprecipitation and electrophoretic mobility shift assay that PITX3 binds to MIP/AQP0 promoter region in vivo and is able to interact with both bicoid sites in vitro. In addition, we show that wild-type PITX3 is able to activate the MIP/AQP0 promoter via interaction with the proximal bicoid site in cotransfection experiments and that the introduction of mutations disrupting binding to this site abolishes this activation. Furthermore, mutant forms of PITX3 fail to produce the same levels of transactivation as wild-type when cotransfected with the MIP/AQP0 reporter. Finally, knockdown of pitx3 in zebrafish affects formation of a DNA-protein complex associated with mip1 promoter sequences; and examination of expression in pitx3 morphant and control zebrafish revealed a delay in and reduction of mip1 expression in pitx3-deficient embryos. Therefore, our data suggest that PITX3 is involved in direct regulation of MIP/AQP0 expression and that the alteration of MIP/AQP0 expression is likely to contribute to the lens phenotype in cataract patients with PITX3 mutations
Influence of bestatin, an inhibitor of aminopeptidases, on T and B lymphocyte subsets in mice
Bestatin, a low-molecular weight dipeptide, is a potent inhibitor of aminopeptidase N which has been demonstrated to have antitumor and immunomodulatory effects. The effects of bestatin (10, 1 and 0.1mg/kg) administered intraperitoneally once, five or ten times to mice on the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes and the percentage and the absolute number of T cell subsets (CD4+CD8+, CD4-CD8-, CD4+, CD8+) in the thymus and T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the spleen and mesenteric lymph nodes were studied. It has been found that bestatin administered ten times at doses of 10, 1 and 0.1 mg/kg increased the total number of thymocytes, splenocytes and lymphocytes of mesenteric lymph nodes. Bestatin also changed the percentage and the absolute number of T cell subsets in the thymus and T and B lymphocytes in the peripheral lymphatic organs. Five and ten exposures to bestatin (10, 1 and 0.1 mg/kg) increased the absolute count of both immature CD4+CD8+ and CD4-CD8- thymic cells. Moreover, both a single and multiple administration of bestatin (1 and 0.1 mg/kg) decreased the percentage and absolute count of CD3+ splenocytes and mesenteric lymph node cells with corresponding decreases in the percentage and absolute count of CD4+ and CD8+ cells. Both a single and multiple administration of bestatin at all the doses under investigation augmented the percentage and the absolute count of CD19+ (B lymphocytes) in the peripheral lymphatic organs. The results of the study show that there is a relationship between the effect induced by bestatin and the dose of the drug as well as the number of doses applied. The strongest effect on the T and B lymphocyte subsets was noted after five injections of bestatin at doses of 1 and 0.1 mg/kg
The effect of florfenicol on lymphocyte subsets and humoral immune response in mice
Florfenicol is a broad-spectrum bacteriostatic antibiotic used in domestic animals. The aim of the
study was to determine the effect of florfenicol on the total number of lymphocytes in the thymus,
spleen and mesenteric lymph nodes and the percentage and the absolute number of T cell subsets
(CD4+CD8+, CD4-CD8-, CD4+, CD8+) in the thymus and T (CD3+, CD4+, CD8+) and B (CD19+)
lymphocytes in the peripheral lymphatic organs in non-immunized mice and humoral immune response
in sheep red blood cells (SRBC)-immunized mice. Florfenicol was administered orally at
a dose of 30 mg/kg six times at 24 h intervals to non-immunized mice and four or seven times at 24 h
intervals to SRBC-immunized mice. SRBC was injected 2 hours prior to the first dose of the drug.
Florfenicol increased the percentage of CD4-CD8- thymocytes and the absolute number of CD4+ and
CD8+ thymocytes on day 7. The increased percentage and absolute number of CD3+, CD4+ and
CD8+ lymphocytes in mesenteric lymph nodes and decreased percentage of lymphocytes B were also
observed 24 hours from the last administration of florfenicol. Florfenicol administered after SRBC
immunization reduced the number of plaque forming cells (PFC) and the production of anti-SRBC
antibodies on days 4 and 7 after priming
Modeling of nitriding and PVD processes improving the durability of X37CrMoV51 steel
W artykule przedstawiono procedury modelowania procesów modyfikujących warstwę wierzchnią form do ciśnieniowego odlewania aluminium wykonanych ze stali WCL Zaprojektowano proces azotowania, wykorzystując własne narzędzia do modelowania wzrostu warstwy azotowanej oraz do optymalizacji parametrów procesu pod kątem uzyskania warstwy azotowanej odpowiedniej pod powłokę PVD. Zrealizowano proces azotowania wg parametrów otrzymanych na podstawie modelowania, monitorując proces czujnikiem magnetycznym (czujnik rezultatu). Przeprowadzono dobór powłoki PVD, kierując się uzyskaniem maksymalnej adhezji do azotowanego podłoża. Modyfikowana forma po azotowaniu i nałożeniu wielowarstwowej powłoki TiN/TiCN/TiAlN uzyskała trzykrotne większą trwałość eksploatacyjną.The paper presents processes improving the durability of casting moulds for pressure die casting of aluminum. The goal of the work was surface modification of casting mould made from X37CrMoV51 steel. These processes comprise the thermochemical treatment (here nitriding) of the mould surface and thin film PVD deposition. The nitriding process was designed using own formulated computing tools [3, 4, 6, 7] to model the nitrided layer growth. The nitriding process was optimised to obtain the nitriding layer suitable for the proposed PVD coating. At this stage of technology the most important aim is to avoid ? (Fe2,3N) and ?' (Fe4N) phases reducing the adhesion of PVD coating to the substrate - nitrided mould (Fig. 1). The nitriding process was realised when applying the parameters obtained from theoretical modeling. Additionally, this stage of surface modification was monitored by a magnetic sensor (result sensor) which reacts to nitriding layer forming. The selection of thin hard PVD coatings with the best possible adhesion to nitrided mould was made. They were: monolayer coating TiAlN with high hardness above 2500-3500 HV0,05 and excellent "work temperature" - 1123 K (Table 2), multilayer TiN/TiCN/TiAlN and TiN/TiN+TiAlN/TiAlN coatings. The multilayer coatings present better wear resistance and critical load (adhesion) than monolayer TiAlN one (Figs. 7 and 8). Hence, modified casting moulds have more than three times increase in durability
A complex intronic enhancer regulates expression of the CFTR gene by direct interaction with the promoter.
Genes can maintain spatiotemporal expression patterns by long-range interactions between cis-acting elements. The cystic fibrosis transmembrane conductance regulator gene (CFTR) is expressed primarily in epithelial cells. An element located within a DNase I-hypersensitive site (DHS) 10 kb into the first intron was previously shown to augment CFTR promoter activity in a tissue-specific manner. Here, we reveal the mechanism by which this element influences CFTR transcription. We employed a high-resolution method of mapping DHS using tiled microarrays to accurately locate the intron 1 DHS. Transfection of promoter-reporter constructs demonstrated that the element displays classical tissue-specific enhancer properties and can independently recruit factors necessary for transcription initiation. In vitro DNase I footprinting analysis identified a protected region that corresponds to a conserved, predicted binding site for hepatocyte nuclear factor 1 (HNF1). We demonstrate by electromobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) that HNF1 binds to this element both in vitro and in vivo. Moreover, using chromosome conformation capture (3C) analysis, we show that this element interacts with the CFTR promoter in CFTR-expressing cells. These data provide the first insight into the three- dimensional (3D) structure of the CFTR locus and confirm the contribution of intronic cis-acting elements to the regulation of CFTR gene expression
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