Showing papers by "University of Marburg published in 1998"
TL;DR: The intracellular amassing of compatible solutes as an adaptive strategy to high-osmolality environments is evolutionarily well-conserved in Bacteria, Archaea, and Eukarya.
Abstract: All microorganisms possess a positive turgor, and maintenance of this outward-directed pressure is essential since it is generally considered as the driving force for cell expansion. Exposure of microorganisms to high-osmolality environments triggers rapid fluxes of cell water along the osmotic gradient out of the cell, thus causing a reduction in turgor and dehydration of the cytoplasm. To counteract the outflow of water, microorganisms increase their intracellular solute pool by amassing large amounts of organic osmolytes, the so-called compatible solutes. These osmoprotectants are highly congruous with the physiology of the cell and comprise a limited number of substances including the disaccharide trehalose, the amino acid proline, and the trimethylammonium compound glycine betaine. The intracellular amassing of compatible solutes as an adaptive strategy to high-osmolality environments is evolutionarily well-conserved in Bacteria, Archaea, and Eukarya. Furthermore, the nature of the osmolytes that are accumulated during water stress is maintained across the kingdoms, reflecting fundamental constraints on the kind of solutes that are compatible with macromolecular and cellular functions. Generally, compatible solutes can be amassed by microorganisms through uptake and synthesis. Here we summarise the molecular mechanisms of compatible solute accumulation in Escherichia coli and Bacillus subtilis, model organisms for the gram-negative and gram-positive branches of bacteria.
1,024 citations
TL;DR: It is proposed that plants have a plasma membrane enzyme similar to the neutrophil NADPH oxidase but with novel potential regulatory mechanisms for Ca2+ and G protein stimulation of O2− and H2O2 production at the cell surface.
Abstract: Rapid generation of O2- and H2O2, which is reminiscent of the oxidative burst in neutrophils, is a central component of the resistance response of plants to pathogen challenge. Here, we report that the Arabidopsis rbohA (for respiratory burst oxidase homolog A) gene encodes a putative 108-kD protein, with a C-terminal region that shows pronounced similarity to the 69-kD apoprotein of the gp91phox subunit of the neutrophil respiratory burst NADPH oxidase. The RbohA protein has a large hydrophilic N-terminal domain that is not present in gp91phox. This domain contains two Ca2+ binding EF hand motifs and has extended similarity to the human RanGTPase-activating protein 1. rbohA, which is a member of a divergent gene family, generates transcripts of 3.6 and 4.0 kb that differ only in their polyadenylation sites. rbohA transcripts are most abundant in roots, with weaker expression in aerial organs and seedlings. Antibodies raised against a peptide near the RbohA C terminus detected a 105-kD protein that, unlike gp91phox, does not appear to be highly glycosylated. Cell fractionation, two-phase partitioning, and detergent extraction indicate that RbohA is an intrinsic plasma membrane protein. We propose that plants have a plasma membrane enzyme similar to the neutrophil NADPH oxidase but with novel potential regulatory mechanisms for Ca2+ and G protein stimulation of O2- and H2O2 production at the cell surface.
618 citations
TL;DR: A hitherto unrecognized cross‐talk between ovarian hormones could be crucial for their growth‐promoting effects on cancer cells, as shown in progestins and T47D cell proliferation.
Abstract: The molecular mechanisms by which ovarian hormones stimulate growth of breast tumors are unclear. It has been reported previously that estrogens activate the signal‐transducing Src/p21 ras /Erk pathway in human breast cancer cells via an interaction of estrogen receptor (ER) with c‐Src. We now show that progestins stimulate human breast cancer T47D cell proliferation and induce a similar rapid and transient activation of the pathway which, surprisingly, is blocked not only by anti‐progestins but also by anti‐estrogens. In Cos‐7 cells transfected with the B isoform of progesterone receptor (PR B ), progestin activation of the MAP kinase pathway depends on co‐transfection of ER. A transcriptionally inactive PR B mutant also activates the signaling pathway, demonstrating that this activity is independent of transcriptional effects. PR B does not interact with c‐Src but associates via the N‐terminal 168 amino acids with ER. This association is required for the signaling pathway activation by progestins. We propose that ER transmits to the Src/p21 ras /Erk pathway signals received from the agonist‐activated PR B . These findings reveal a hitherto unrecognized cross‐talk between ovarian hormones which could be crucial for their growth‐promoting effects on cancer cells.
611 citations
TL;DR: It is considered that proteolytic processing of GP may be an important determinant for the pathogenicity of Ebola virus.
Abstract: In the present study, we have investigated processing and maturation of the envelope glycoprotein (GP) of Ebola virus. When GP expressed from vaccinia virus vectors was analyzed by pulse–chase experiments, the mature form and two different precursors were identified. First, the endoplasmic reticulum form preGPer, full-length GP with oligomannosidic N-glycans, was detected. preGPer (110 kDa) was replaced by the Golgi-specific form preGP (160 kDa), full-length GP containing mature carbohydrates. preGP was finally converted by proteolysis into mature GP1,2, which consisted of two disulfide-linked cleavage products, the amino-terminal 140-kDa fragment GP1, and the carboxyl-terminal 26-kDa fragment GP2. GP1,2 was also identified in Ebola virions. Studies employing site-directed mutagenesis revealed that GP was cleaved at a multibasic amino acid motif located at positions 497 to 501 of the ORF. Cleavage was blocked by a peptidyl chloromethylketone containing such a motif. GP is cleaved by the proprotein convertase furin. This was indicated by the observation that cleavage did not occur when GP was expressed in furin-defective LoVo cells but that it was restored in these cells by vector-expressed furin. The Reston subtype, which differs from all other Ebola viruses by its low human pathogenicity, has a reduced cleavability due to a mutation at the cleavage site. As a result of these observations, it should now be considered that proteolytic processing of GP may be an important determinant for the pathogenicity of Ebola virus.
477 citations
TL;DR: It is shown for the first time that the production of biologically significant amounts of IL-1β in the brain can be induced by a sustained increase in the activity of a discrete population of neurons and a physiological involvement of this cytokine in synaptic plasticity is suggested.
Abstract: It is widely accepted that interleukin-1β (IL-1β), a cytokine produced not only by immune cells but also by glial cells and certain neurons influences brain functions during infectious and inflammatory processes. It is still unclear, however, whether IL-1 production is triggered under nonpathological conditions during activation of a discrete neuronal population and whether this production has functional implications. Here, we show in vivo and in vitro that IL-1β gene expression is substantially increased during long-term potentiation of synaptic transmission, a process considered to underlie certain forms of learning and memory. The increase in gene expression was long lasting, specific to potentiation, and could be prevented by blockade of potentiation with the N-methyl-d-aspartate (NMDA) receptor antagonist, (±)-2-amino-5-phosphonopentanoic acid (AP-5). Furthermore, blockade of IL-1 receptors by the specific interleukin-1 receptor antagonist (IL-1ra) resulted in a reversible impairment of long-term potentiation maintenance without affecting its induction. These results show for the first time that the production of biologically significant amounts of IL-1β in the brain can be induced by a sustained increase in the activity of a discrete population of neurons and suggest a physiological involvement of this cytokine in synaptic plasticity.
469 citations
TL;DR: A new fungus isolate was discovered in an arbuscular mycorrhizal fungal spore from a desert soil in India that could easily be cultivated on various synthetic media, and formed pear-shaped chlamydos...
Abstract: A new fungus isolate was discovered in an arbuscular mycorrhizal fungal spore from a desert soil in India. It could easily be cultivated on various synthetic media, and formed pear-shaped chlamydos...
448 citations
TL;DR: The discovery of a domain--the cold-shock domain--that shows strikingly high homology and similar RNA-binding properties to CSPs in a growing number of eukaryotic nucleic-acid-binding proteins suggests that these proteins have an ancient origin.
419 citations
TL;DR: The structure reported here represents the protein-conducting channel of the mitochondrial outer membrane of mitochondria, which mediates integration of proteins into and translocation across the lipid bilayer.
384 citations
TL;DR: Results strongly suggest the condensation domain to be involved in the catalysis of nonribosomal peptide bond formation with the histidine 147 playing a catalytic role.
349 citations
TL;DR: Vesicular acetylcholine transporter immunoreactivity was particularly useful for identification of parasympathetic intrinsic ganglia, and their terminal fields, in heart, uterus, and other peripheral organs receiving parASYmpathetic innervation.
314 citations
TL;DR: In humans, ex(9-39)NH2 is a potent GLP-1 antagonist without any agonistic properties and has no effect on plasma levels of insulin during euglycemia but decreased plasma insulin during hyperglycemia.
Abstract: The gastrointestinal hormone, glucagon-like peptide-1(7-36)amide (GLP-1) is released after a meal. The potency of synthetic GLP-1 in stimulating insulin secretion and in inhibiting glucagon secretion indicates the putative physiological function of GLP-1. In vitro, the nonmammalian peptide, exendin(9-39)amide [ex(9-39)NH2], is a specific and competitive antagonist of GLP-1. This in vivo study examined the efficacy of ex(9-39)NH2 as an antagonist of exogenous GLP-1 and the physiological role of endogenous GLP-1. Six healthy volunteers underwent 10 experiments in random order. In each experiment, a 30-min period of euglycemia was followed by an intravenous infusion of glucose for 150 min that established a stable hyperglycemia of 8 mmol/liter. There was a concomitant intravenous infusion of one of the following: (1) saline, (2) GLP-1 (for 60 min at 0.3 pmol . kg-1 . min-1 that established physiological postprandial plasma levels, and for another 60 min at 0.9 pmol . kg-1 . min-1 to induce supraphysiological plasma levels), (3-5) ex(9-39)NH2 at 30, 60, or 300 pmol . kg-1 . min-1 + GLP-1, (6-8) ex(9-39)NH2 at 30, 60, or 300 pmol . kg-1 . min-1 + saline, (9 and 10) GIP (glucose-dependent insulinotropic peptide; for 60 min at 0.8 pmol . kg-1 . min-1, with saline or ex(9-39)NH2 at 300 pmol . kg-1 . min-1). Each volunteer received each of these concomitant infusions on separate days. ex(9-39)NH2 dose-dependently reduced the insulinotropic action of GLP-1 with the inhibitory effect declining with increasing doses of GLP-1. ex(9-39)NH2 at 300 pmol . kg-1 . min-1 blocked the insulinotropic effect of physiological doses of GLP-1 and completely antagonized the glucagonostatic effect at both doses of GLP-1. Given alone, this load of ex(9-39)NH2 increased plasma glucagon levels during euglycemia and hyperglycemia. It had no effect on plasma levels of insulin during euglycemia but decreased plasma insulin during hyperglycemia. ex(9-39)NH2 did not alter GIP-stimulated insulin secretion. These data indicate that in humans, ex(9-39)NH2 is a potent GLP-1 antagonist without any agonistic properties. The pancreatic A cell is under a tonic inhibitory control of GLP-1. At hyperglycemia, the B cell is under a tonic stimulatory control of GLP-1.
TL;DR: It is found that dyslexics have a specific speech processing deficit at the sensory level which could be used to identify children at risk at an early age.
Abstract: In order to investigate the relationship between dyslexia and central auditory processing, 19 children with spelling disability and 15 controls at grades 5 and 6 were examined using a passive oddball paradigm. Mismatch negativity (MMN) was determined for tone and speech stimuli. While there were no group differences for the tone stimuli, we found a significantly attenuated MMN in the dyslexic group for the speech stimuli. This finding leads to the conclusion that dyslexics have a specific speech processing deficit at the sensory level which could be used to identify children at risk at an early age.
TL;DR: In this article, relativistic ECPs with large valence basis sets for the metals are reported for the complexes of CuCl, AgCl, and AuCl with the N-heterocyclic carbene imidazol-2-ylidene 1 and the related silylene 2 and germylene 3.
11 Nov 1998-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The HERMES experiment as mentioned in this paper collects data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of H, D, and 3 He.
Abstract: The HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of H, D, and 3 He. These data give information on the spin structure of the nucleon. This paper describes the forward angle spectrometer built for this purpose. The spectrometer includes numerous tracking chambers (micro-strip gas chambers, drift and proportional chambers) in front of and behind a 1.3 T.m magnetic field, as well as an extensive set of detectors for particle identification (a lead-glass calorimeter, a pre-shower detector, a transition radiation detector, and a threshold Cherenkov detector). Two of the main features of the spectrometer are its good acceptance and identification of both positrons and hadrons, in particular pions. These characteristics, together with the purity of the targets, are allowing HERMES to make unique contributions to the understanding of how the spins of the quarks contribute to the spin of the nucleon.
TL;DR: It is concluded that most differences between the organisms primarily reflect the different biosynthetic capacities of the host cells they invade.
Abstract: Plasmodium and Toxoplasma belong to a group of unicellular parasites which actively penetrate their respective mammalian host cells. During the process of invasion, they initiate the formation of a membrane, the so-called parasitophorous vacuolar membrane, which surrounds the intracellular parasite and which differs substantially from endosomal membranes or the membrane of phagolysosomes. The biogenesis and the maintenance of the vacuolar membrane are closely related to the peculiar cellular organization of these parasites and are unique phenomena in cell biology. Here we compare biological similarities and differences between the two parasites, with respect to: (i) the formation, (ii) the maintenance, and (iii) the biological role of the vacuolar membrane. We conclude that most differences between the organisms primarily reflect the different biosynthetic capacities of the host cells they invade.
TL;DR: This work has shown that the cold shock protein CspB from Bacillus subtilis is only marginally stable, but it folds extremely fast in a simple N \[rlharr] U two-state reaction.
Abstract: The cold shock protein CspB from Bacillus subtilis is only marginally stable, but it folds extremely fast in a simple N reversible U two-state reaction. The corresponding cold shock proteins from the thermophile Bacillus caldolyticus and the hyperthermophile Thermotoga maritima show strongly increased conformational stabilities, but unchanged very fast two-state refolding kinetics. The absence of intermediates in the folding of B. subtilis CspB is thus not a corollary of its low stability. Rather, two-state folding and an unusually native-like activated state of folding seem to be inherent properties of these small all-beta proteins. There is no link between stability and folding rate, and numerous sequence positions exist which can be varied to modulate the stability without affecting the rate and mechanism of folding.
TL;DR: In this review, common principles of assembly for all systems and the mmicular mechanisms predicted for each system are summarized.
Abstract: The past 10 years have heralded remarkable progress in the understanding of the biogenesis of c-type cytochromes. The hallmark of c-type cytochrome synthesis is the covalent ligation of haem vinyl groups to two cysteinyl residues of the apocytochrome (at a Cys-Xxx-Yyy-Cys-His signature motif). From genetic, genomic and biochemical studies, it is clear that three distinct systems have evolved in nature to assemble this ancient protein. In this review, common principles of assembly for all systems and the molecular mechanisms predicted for each system are summarized. Prokaryotes, plant mitochondria and chloroplasts use either system I or II, which are each predicted to use dedicated mechanisms for haem delivery, apocytochrome ushering and thioreduction. Accessory proteins of systems I and II co-ordinate the positioning of these two substrates at the membrane surface for covalent ligation. The third system has evolved specifically in mitochondria of fungi, invertebrates and vertebrates. For system III, a pivotal role is played by an enzyme called cytochrome c haem lyase (CCHL) in the mitochondrial intermembrane space.
TL;DR: This review summarizes recent progress in understanding how Myc stimulates cell proliferation and how this might contribute to cellular transformation and tumorigenesis.
TL;DR: Stereoselective intermolecular [2+2]-photocycloaddition reactions of alkenes and Paterno-Buchi reactions are reviewed in this article.
Abstract: Stereoselective intermolecular [2+2]-photocycloaddition reactions of alkenes and Paterno–Buchi reactions are reviewed. For both reactions the regioselectivity and the simple diastereoselectivity which are relevant to the formation of a single product isomer are explained based on representative examples. In the subsequent sections the facial diastereoselectivity induced by the respective reaction partner is treated. Particular emphasis is given on synthetic applications of the cyclobutanes and oxetanes obtained by the photochemical key step. Consecutive reactions are discussed and the potential use of the four-membered ring intermediates is highlighted.
TL;DR: Several lines of evidence indicate that many of the known fungal G proteins influence the intracellular level of cAMP by either stimulating or inhibiting adenylyl cyclase.
TL;DR: The physiological role of the σB‐dependent general stress genes was identified and the stress tolerance of wild‐type cells with mutants lacking ρB or general stress proteins was compared.
Abstract: Bacillus subtilis cells respond almost immediately to different stress conditions by increasing the production of general stress proteins (GSPs). The genes encoding the majority of the GSPs that are induced by heat, ethanol, salt stress or by starvation for glucose, oxygen or phosphate belong to the sigmaB-dependent general stress regulon. Despite a good understanding of the complex regulation of the activity of sigmaB and knowledge of a very large number of general stress genes controlled by sigmaB, first insights into the physiological role of this nonspecific stress response have been obtained only very recently. To explore the physiological role of this reguIon, we and others identified sigmaB-dependent general stress genes and compared the stress tolerance of wild-type cells with mutants lacking sigmaB or general stress proteins. The proteins encoded by sigmaB-dependent general stress genes can be divided into at least five functional groups that most probably provide growth-restricted B. subtilis cells with a multiple stress resistance in anticipation of future stress. In particular, sigB mutants are impaired in non-specific resistance to oxidative stress, which requires the sigmaB-dependent dps gene encoding a DNA-protecting protein. Protection against oxidative damage of membranes, proteins or DNA could be the most essential component of sigmaB mediated general stress resistance in growth-arrested aerobic gram-positive bacteria. Other general stress genes have both a sigmaB-dependent induction pathway and a second sigmaB-independent mechanism of stress induction, thereby partially compensating for a sigmaB deficiency in a sigB mutant. In contrast to sigB mutants, null mutations in genes encoding those proteins, such as cIpP or cIpC, cause extreme sensitivity to salt or heat.
TL;DR: Northern blot analysis of viral RNA revealed that three nucleocapsid proteins were essential and sufficient for transcription as well as replication and encapsidation and indicate that VP35, rather than VP30, is the functional homologue of rhabdo- and paramyxovirus P proteins.
Abstract: This paper describes the first reconstituted replication system established for a member of the Filoviridae, Marburg virus (MBGV). MBGV minigenomes containing the leader and trailer regions of the MBGV genome and the chloramphenicol acetyltransferase (CAT) gene were constructed. In MBGV-infected cells, these minigenomes were replicated and encapsidated and could be passaged. Unlike most other members of the order Mononegavirales, filoviruses possess four proteins presumed to be components of the nucleocapsid (NP, VP35, VP30, and L). To determine the protein requirements for replication and transcription, a reverse genetic system was established for MBGV based on the vaccinia virus T7 expression system. Northern blot analysis of viral RNA revealed that three nucleocapsid proteins (NP, VP35, and L) were essential and sufficient for transcription as well as replication and encapsidation. These data indicate that VP35, rather than VP30, is the functional homologue of rhabdo- and paramyxovirus P proteins. The reconstituted replication system was profoundly affected by the NP-to-VP35 expression ratio. To investigate whether CAT gene expression was achieved entirely by mRNA or in part by full-length plus-strand minigenomes, a copy-back minireplicon containing the CAT gene but lacking MBGV-specific transcriptional start sites was employed in the artificial replication system. This construct was replicated without accompanying CAT activity. It was concluded that the CAT activity reflected MBGV-specific transcription and not replication.
TL;DR: It is concluded that in OS tidal breathing can be affected by EFL and PEEPi; two-thirds of the subjects with a mean body mass index of 44 +/- 5 kg/m2 and six age-matched normal-weight control subjects (CS) are studied in different body positions; and the increased diaphragmatic load in the supine position is, in part, related to PEPi.
Abstract: Breathing at very low lung volumes might be affected by decreased expiratory airflow and air trapping. Our purpose was to detect expiratory flow limitation (EFL) and, as a consequence, intrinsic po...
TL;DR: This article presented a phylogenetic analysis of nine strains of symbiotic nitrogenfixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain.
Abstract: We present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain. These and several reference strains were characterized genotypically at different levels of taxonomic resolution by computer-assisted analysis of 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphisms (PCR-RFLPs), 16S-23S rDNA intergenic spacer (IGS) RFLPs, and repetitive extragenic palindromic PCR (rep-PCR) genomic fingerprints with BOX, ERIC, and REP primers. Cluster analysis of 16S rDNA restriction patterns with four tetrameric endonucleases grouped the Canarian isolates with the two reference strains, Bradyrhizobium japonicum USDA 110spc4 and Bradyrhizobium sp. strain (Centrosema) CIAT 3101, resolving three genotypes within these bradyrhizobia. In the analysis of IGS RFLPs with three enzymes, six groups were found, whereas rep-PCR fingerprinting revealed an even greater genotypic diversity, with only two of the Canarian strains having similar fingerprints. Furthermore, we show that IGS RFLPs and even very dissimilar rep-PCR fingerprints can be clustered into phylogenetically sound groupings by combining them with 16S rDNA RFLPs in computer-assisted cluster analysis of electrophoretic patterns. The DNA sequence analysis of a highly variable 264-bp segment of the 16S rRNA genes of these strains was found to be consistent with the fingerprint-based classification. Three different DNA sequences were obtained, one of which was not previously described, and all belonged to the B. japonicum/Rhodopseudomonas rDNA cluster. Nodulation assays revealed that none of the Canarian isolates nodulated Glycine max or Leucaena leucocephala, but all nodulated Acacia pendula, C. proliferus, Macroptilium atropurpureum, and Vigna unguiculata.
TL;DR: Electron microscopy of purified snR42 and snR30 particles revealed that these two snoRNPs possess a similar bipartite structure that is proposed to be a major structural determining principle for all H/ACA sno RNPs.
Abstract: The eukaryotic nucleolus contains a large number of small nucleolar RNAs (snoRNAs) that are involved in preribosomal RNA (pre-rRNA) processing. The H box/ACA-motif (H/ACA) class of snoRNAs has recently been demonstrated to function as guide RNAs targeting specific uridines in the pre-rRNA for pseudouridine (psi) synthesis. To characterize the protein components of this class of snoRNPs, we have purified the snR42 and snR30 snoRNP complexes by anti-m3G-immunoaffinity and Mono-Q chromatography of Saccharomyces cerevisiae extracts. Sequence analysis of the individual polypeptides demonstrated that the three proteins Gar1p, Nhp2p, and Cbf5p are common to both the snR30 and snR42 complexes. Nhp2p is a highly basic protein that belongs to a family of putative RNA-binding proteins. Cbf5p has recently been demonstrated to be involved in ribosome biogenesis and also shows striking homology with known prokaryotic psi synthases. The presence of Cbf5p, a putative psi synthase in each H/ACA snoRNP suggests that this class of RNPs functions as individual modification enzymes. Immunoprecipitation studies using either anti-Cbf5p antibodies or a hemagglutinin-tagged Nhp2p demonstrated that both proteins are associated with all H/ACA-motif snoRNPs. In vivo depletion of Nhp2p results in a reduction in the steady-state levels of all H/ACA snoRNAs. Electron microscopy of purified snR42 and snR30 particles revealed that these two snoRNPs possess a similar bipartite structure that we propose to be a major structural determining principle for all H/ACA snoRNPs.
TL;DR: 14 of the 47 HRPs are reexamined about 4 years after the index investigation and found surprisingly constant DEX-CRH test results, so that one of the requirements for a vulnerability marker is fulfilled.
TL;DR: The expression of COX-2, but not the expression ofCOX-1, was found to be elevated in a disease-related pattern in the synovial tissue from patients with RA, AS, or PsA in comparison with OA samples, and was especially high in AS synovIAL tissue.
Abstract: Objective
To compare the expression of the cyclooxygenase (COX) isoforms, COX-1 and COX-2, in synovial tissue samples between patients with inflammatory arthritis (i.e., rheumatoid arthritis [RA], ankylosing spondylitis [AS], or psoriatic arthritis [PsA]) and patients with osteoarthritis (OA).
Methods
Paraffin-embedded sections of synovial tissue from patients with OA (n = 18), RA (n = 35), AS (n = 9), and PsA (n = 16) were immunostained for COX-1 and COX-2. Staining intensity was quantified videodensitometrically from specific synovial cell areas. In addition, samples of OA and RA synovial tissue were analyzed for levels of COX-1 and COX-2 messenger RNA (mRNA) using reverse transcriptase-polymerase chain reaction.
Results
Strong COX-2 immunostaining was observed in synovial blood vessel endothelium, synovial lining cells, chondrocytes, and subsynovial fibroblast-like cells in patients with inflammatory arthritides. In the blood vessels, the mean (±SD) optical density (MOD) of staining was elevated, especially in AS samples (2.73 ± 0.63), but also in PsA (1.99 ± 0.66) and RA samples (1.54 ± 0.73), in comparison with OA synovial tissue (0.84 ± 0.30; P < 0.01 versus other groups). COX-1 staining was almost exclusively localized in synovial lining cells, with no significant differences in the MOD between the diseases. COX-2 mRNA expression was higher in RA than in OA samples (P < 0.05).
Conclusion
The expression of COX-2, but not the expression of COX-1, was found to be elevated in a disease-related pattern in the synovial tissue from patients with RA, AS, or PsA in comparison with OA samples, and was especially high in AS synovial tissue. These results may improve our understanding of the pathogenesis of different arthritic diseases, and may have implications for the use of selective COX-2 inhibitors in the treatment of inflammatory joint symptoms.
TL;DR: It is confirmed that rabies VNA is an absolute requirement for clearance of an established rabies virus infection, however, for the latter to occur in a timely fashion, collaboration between VNA and inflammatory mechanisms is necessary.
Abstract: To investigate the involvement of various cellular and humoral aspects of immunity in the clearance of rabies virus from the central nervous system, (CNS), we studied the development of clinical signs and virus clearance from the CNS in knockout mice lacking either B and T cells, CD8+ cytotoxic T cells, B cells, alpha/beta interferon (IFN-α/β) receptors, IFN-γ receptors, or complement components C3 and C4. Following intranasal infection with the attenuated rabies virus CVS-F3, normal adult mice of different genetic backgrounds developed a transient disease characterized by loss of body weight and appetite depression which peaked at 13 days postinfection (p.i.). While these animals had completely recovered by day 21 p.i., mice lacking either B and T cells or B cells alone developed a progressive disease and succumbed to infection. Mice lacking either CD8+ T cells, IFN receptors, or complement components C3 and C4 showed no significant differences in the development of clinical signs by comparison with intact counterparts having the same genetic background. However, while infectious virus and viral RNA could be detected in normal control mice only until day 8 p.i., in all of the gene knockout mice studied except those lacking C3 and C4, virus infection persisted through day 21 p.i. Analysis of rabies virus-specific antibody production together with histological assessment of brain inflammation in infected animals revealed that clearance of CVS-F3 by 21 days p.i. correlated with both a strong inflammatory response in the CNS early in the infection (day 8 p.i.), and the rapid (day 10 p.i.) production of significant levels of virus-neutralizing antibody (VNA). These studies confirm that rabies VNA is an absolute requirement for clearance of an established rabies virus infection. However, for the latter to occur in a timely fashion, collaboration between VNA and inflammatory mechanisms is necessary.
TL;DR: It is demonstrated that purified U5 snRNPs exhibit ATP-dependent unwinding of U4/U6 RNA duplices in vitro, raising the interesting possibility that this RNA helicase catalyzes unwinding in the spliceosome.
Abstract: Splicing of nuclear precursors of mRNA (pre-mRNA) involves dynamic interactions between the RNA constituents of the spliceosome. The rearrangement of RNA–RNA interactions, such as the unwinding of the U4/U6 duplex, is believed to be driven by ATP-dependent RNA helicases. We recently have shown that spliceosomal U5 small nuclear ribonucleoproteins (snRNPs) from HeLa cells contain two proteins, U5–200kD and U5–100kD, which share homology with the DEAD/DEXH-box families of RNA helicases. Here we demonstrate that purified U5 snRNPs exhibit ATP-dependent unwinding of U4/U6 RNA duplices in vitro. To identify the protein responsible for this activity, U5 snRNPs were depleted of a subset of proteins under high salt concentrations and assayed for RNA unwinding. The activity was retained in U5 snRNPs that contain the U5–200kD protein but lack U5–100kD, suggesting that the U5–200kD protein could mediate U4/U6 duplex unwinding. Finally, U5–200kD was purified to homogeneity by glycerol gradient centrifugation of U5 snRNP proteins in the presence of sodium thiocyanate, followed by ion exchange chromatography. The RNA unwinding activity was found to reside exclusively with the U5–200kD DEXH-box protein. Our data raise the interesting possibility that this RNA helicase catalyzes unwinding of the U4/U6 RNA duplex in the spliceosome.
TL;DR: The 87-item SIAB-EX was originally developed for detailed assessment of eating disorders cross-sectionally and longitudinally and the updated version which allows for diagnosis according to DSM-IV and ICD-10 is described here.
Abstract: Objectives: Earlier versions of the Structured Interview for Anorexic and Bulimic Disorders (SIAB) were modified in order to include new research findings and to update the expert rating interview to the diagnostic criteria of DSM-IV and ICD-10. The semistandardized interview was developed for reliable and valid assessment of the specific as well as the general psychopathology of eating disorders. Method: Data from SIAB-EX interviews (current and past/lifetime symptom expression) were available from three samples: (a) 330 eating-disordered patients assessed at the start of treatment, (b) 148 former eating-disordered patients with anorexia nervosa (AN) or bulimia nervosa (BN) assessed at follow-up, and (c) 111 community controls. Sixty-one of the 87 items of the SIAB-EX with a 5-point scale were factor analyzed. Results: Principal components analyses with varimax rotation produced the following six components of the SIAB-EX (lifetime): (I) Body Image and Slimness Ideal; (II) General Psychopathology; (III) Sexuality and Social Integration; (IV) Bulimic Symptoms; (V) Measures to Counteract Weight Gain, Fasting, and Substance Abuse; and (VI) Atypical Binges. The factor solution for the current symptom expression was very similar to that based on lifetime symptom expression. Average item and factor scores are given for six groups of eating-disordered patients and controls. High interrater reliability was established for both current and the past symptom expression. Cronbach's alpha coefficients indicated good internal consistency for five of the six components of the SIAB-EX. DSM-IV and ICD-10 diagnoses for eating disorders can be derived directly or by using a computer algorithm from the SIAB-EX. A detailed 90-page manual facilitates the training of interviewers. Conclusion: The 87-item SIAB-EX was originally developed for detailed assessment of eating disorders cross-sectionally and longitudinally. The updated version which allows for diagnosis according to DSM-IV and ICD-10 is described here. © 1998 by John Wiley & Sons, Inc. Int J Eat Disord 24: 227–249, 1998.