The SC3 hydrophobin gene of Schizophyllum commune was disrupted by homologous integration of an SC3 genomic fragment interrupted by a phleomycin resistance cassette. The phenotype of the mutant was ...particularly clear in sealed plates in which formation of aerial hyphae was blocked. In non-sealed plates aerial hyphae did form but these were hydrophilic and not hydrophobic as in wild-type strains. Complementation with a genomic SC3 clone restored formation of hydrophobic aerial hyphae in sealed plates. In a dikaryon homozygous for the SC3 mutation normal sporulating fruiting bodies were produced but aerial hyphae were hydrophilic.
Water‐soluble single‐walled carbon nanotubes are readily prepared by treating oxidatively purified nanotubes with molten urea. Evidence is provided for appended amido and ureido groups in the product ...(see figure), which can be further modified by condensation reactions if p‐anisaldehyde is added during the process.
5-fluorouracil (5-FU), the most common antimetabolite used for the treatment of colorectal cancer, exerts its cytotoxic effects through the induction of apoptosis. Folinic acid potentiates the effect ...of 5-FU. Drug activity is currently limited as a result of inducible chemoresistance. Limited research suggests that the transcription factor nuclear factor kappa-B (NF-kappaB), which has antiapoptotic properties, may play a major role in inducible chemoresistance.
SW48 colon cancer cells were used for all experiments. Cell growth was determined by cell proliferation assay. Apoptosis was assessed by measuring caspase 3 activity. Activation of NF-kappaB was ascertained by electrophoretic mobility shift assay, luciferase reporter assay, and Western blot analysis.
Treatment with 5-FU (0.001-10 mm), not only inhibited growth and induced apoptosis but significantly activated NF-kappaB in SW48 cells. Folinic acid alone (0.01-100 mg/L) did not inhibit growth but improved the cytotoxic effect of 5-FU in a dose-dependent manner. Likewise, folinic acid alone did not activate NF-kappaB or induce apoptosis but enhanced 5-FU-mediated NF-kappaB activation and cell apoptosis. Transfection with adenovirus IkappaBalpha super-repressor strongly inhibited constitutive activation of NF-kappaB and significantly enhanced 5-FU and 5-FU/Folinic acid-mediated growth inhibition (P < 0.05).
Treatment with 5-FU activates NF-kappaB. Folinic acid enhances 5-FU-mediated activation of NF-kappaB. Inhibition of NF-kappaB enhances the cytotoxic effect of 5-FU with or without Folinic acid in colon cancer cells.
The fluorescence of protophorphyrin IX (PpIX) synthesized after incubation with 5-aminolevulinic acid (5-Ala) is used for the intraoperative visualisation of glioma cells in vivo. Such fluorescence ...may also be useful for the photodynamic therapy (PTD) of gliomas. A significant difference of fluorescence intensity in tumor cells compared to neurons is required for this application. To explore this, eight human glioma cell lines (LN-18, LN-428, U87MG, U373MG, D247MG, U251MG, LN-308, T98G) were compared with human astrocytes (SV-FHAS) and rat neurons after incubation for different periods of timein vitro with 5-Ala (1mg/ml). Fluorescence intensity profiles were measured by a digital camera comparing glioma cell lines with control cells. All glioma cell lines could be discriminated from neural cells by their intensity of fluorescence by post-hoc tests for pairwise comparisons using Tukey's honestly significant difference test, at the global significance level of 5%. The glioma cell lines showed significant variation in this possibly limiting clinical use of fluorescence as a guide for resection.
GPD regulatory sequences were used to express a phleomycin resistance gene (Sh ble) in Schizophyllum commune, resulting in high numbers of phleomycin-resistant transformants. Attempts to express ...heterologous genes coding for hygromycin B phosphotransferase (hph), aminoglycoside phosphotransferase (apt), beta-glucuronidase (uidA) and beta-galactosidase (lacZ) using the same regulatory sequences were not successful and no mRNA could be detected. Cloning the hph and uidA genes in an internally deleted GPD gene resulted in truncated transcripts which ended within the 5'-parts of the heterologous genes. Cloning of the same genes as transcriptional fusions downstream from the Sh ble gene also resulted in truncated transcripts ending in the 5'-parts of these heterologous genes. It is suggested that AT-rich sequences in heterologous genes might be involved in generating these truncated transcripts, thereby preventing expression in S. commune.
The nucleotide (nt) sequences of the Sc3 and Sc4 genes of the filamentous fungus Schizophyllum commune, and the deduced amino acid (aa) sequences, were determined; moreover, the previously published ...sequence for the Sc1 gene Dons et al., EMBO J. 3 (1984) 2101-2106 was corrected. All three independently isolated genes were found to have similar structures and nt sequences of their coding regions. At the aa level the homology is 43-62% (63-69% in the C-terminal parts of the proteins), the hydrophobic aa predominate and the hydrophobicity patterns are similar. All three proteins contain leader sequences and eight cysteines among about 110 aa, conserved at the same positions. Yet these genes are differentially regulated: Sc1 and Sc4 are only expressed at high levels in fruiting dikaryons, whereas Sc3 is highly expressed in both monokaryons and dikaryons, independent from fruiting.
The Sc7 and Sc14 genes are specifically expressed in the dikaryon of the basidiomycete fungus Schizophyllum commune during fruiting. These genes are closely linked (within 6 kb) and highly similar in ...gene structure and nucleotide sequence (70% identical nucleotides in their coding regions). The encoded proteins (204 and 214 amino acids, respectively) have 87% similarity in amino acids (56% of the amino acids are identical). They contain putative signal sequences for secretion, are rich in aromatic amino acids which are generally located at similar positions, and they are generally hydrophilic. Inspection of databanks showed similarities with pathogenesis-related proteins (PR1) from plants, testis-specific proteins from mammals and venom allergen proteins from insects. An antibody raised against a Sc7 fusion protein showed the presence of the Sc7 protein in the culture medium and in the fruit bodies where it is apparently loosely associated with hyphal walls.
67 - Cytokine Biology Minter, Rebecca M.; Wessels, Frank J.; Moldawer, Lyle L.
Surgical Research,
2001
Book Chapter
Cytokine biology is infiltrating all aspects of surgical science, as it becomes evident that these mediators are intimately involved in the inflammatory response. With the current sequencing of the ...human genome, the number of cytokines discovered has increased dramatically. Immunoadhesins and antibodies are two examples of anticytokine-based therapies. The study of cytokine biology has also revealed how some cytokines can counteract the action of other cytokines. This takes advantage of the property that the synthesis of most proinflammatory cytokines is tightly regulated at the level of gene transcription, and they often induce the synthesis of other cytokines that act in an allosteric manner to suppress their synthesis. With the recent explosion in the number of identified cytokines, it is recognized that cytokines can rarely be classified according to their biological function. Rather, most cytokines have overlapping, pleiotropic biologic activities, dependent on what other cytokines and mediators are present in the milieu at that time. What is generally agreed on, however, is that cytokines are protein messengers that convey information among and within cells via specific receptor molecules. Furthermore, cytokines signal to immune and somatic tissues the presence of inflammation, and in doing so, regulate key components of the innate and acquired immune responses. Cytokine signaling can occur in an endocrine, paracrine, autocrine, and juxtacrine fashion, dependent on the cytokine and the current environment in which the cytokine is produced. This is an important consideration when attempting to measure cytokines in biologic fluids, such as the blood, bronchoalveolar lavage, or cerebrospinal fluid.
Since publication of the first edition of Volume I in 1994, the field of fungal biology has developed tremendously, mainly through the advancement of various molecular techniques and international ...fungal genome projects. To accommodate these developments, the second edition has been completely updated. Six chapters have been revised by former authors, others by newly recruited experts, and also novel subjects, emerged in more recent years, have been added to the book.
Leading scientists in the field have compiled comprehensive overviews as well as latest results obtained from cytological, genetic and molecular studies. Topics include: cellular and colony growth of fungi, cellular fusion and incompatibility, senescence and programmed cell death, environmental and physiological signalling in differentiation processes, asexual and sexual reproduction, mitosis and meiosis of various types of fungi. Both parallels and differences become visible between individual fungi as well as between fungal classes.
PDF
