Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 37 (2000), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Plasmids encode partitioning genes (par) that are required for faithful plasmid segregation at cell division. Initially, par loci were identified on plasmids, but more recently they were also found on bacterial chromosomes. We present here a phylogenetic analysis of par loci from plasmids and chromosomes from prokaryotic organisms. All known plasmid-encoded par loci specify three components: a cis-acting centromere-like site and two trans-acting proteins that form a nucleoprotein complex at the centromere (i.e. the partition complex). The proteins are encoded by two genes in an operon that is autoregulated by the par-encoded proteins. In all cases, the upstream gene encodes an ATPase that is essential for partitioning. Recent cytological analyses indicate that the ATPases function as adaptors between a host-encoded component and the partition complex and thereby tether plasmids and chromosomal origin regions to specific subcellular sites (i.e. the poles or quarter-cell positions). Two types of partitioning ATPases are known: the Walker-type ATPases encoded by the par/sop gene family (type I partitioning loci) and the actin-like ATPase encoded by the par locus of plasmid R1 (type II partitioning locus). A phylogenetic analysis of the large family of Walker type of partitioning ATPases yielded a surprising pattern: most of the plasmid-encoded ATPases clustered into distinct subgroups. Surprisingly, however, the par loci encoding these distinct subgroups have different genetic organizations and thus divide the type I loci into types Ia and Ib. A second surprise was that almost all chromosome-encoded ATPases, including members from both Gram-negative and Gram-positive Bacteria and Archaea, clustered into one distinct subgroup. The phylogenetic tree is consistent with lateral gene transfer between Bacteria and Archaea. Using database mining with the ParM ATPase of plasmid R1, we identified a new par gene family from enteric bacteria. These type II loci, which encode ATPases of the actin type, have a genetic organization similar to that of type Ib loci.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1468-2982
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Discontinuation of indomethacin in chronic paroxysmal hemicrania (CPH) usually causes relapse of symptoms within a few days. A patient with characteristic symptoms of CPH is reported. The patient had daily attacks of unilateral headache accompanied by ipsilateral lacrimation and conjunctival injection, a frequency of attacks between four and fourteen per day, and never a headache-free day. He was treated with indomethacin, and all symptoms disappeared within 24 h. After three months indomethacin was discontinued. Six months after that the patient was still symptom-free.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    USA/Oxford, UK : Blackwell Science Ltd
    Cephalalgia 1 (1981), S. 0 
    ISSN: 1468-2982
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Clinical findings of four female members from one family with familial hemiplegic migraine are briefly summarized. Cerebral blood flow (CBF) studies using the xenon 133 inhalation method were carried out during and between hemiplegic attacks in two of the family members. CBF was significantly lower over the affected hemisphere during attacks, while equal flow on both sides was seen in headache free periods. The findings indicate that cerebral perfusion is altered, but not necessarily decreased during attacks of familial hemiplegic migraine.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The aim of this study was to make prognostic comparisons between the modified scheme of Pedersen et al. the definitions of Tavassoli and the Ridolfi criteria for medullary carcinomas. Sixty breast carcinomas primarly diagnosed as medullary carcinomas were reclassified into typical medullary carcinoma (TMC), atypical medullary carcinoma (AMC) and non-medullary carcinoma (NMC) according to the three classifications. The Ridolfi classification proved to be superior to the two other schemes in discriminating survival differences between the three groups TMC, AMC and NMC. All 13 patients with TMC are still alive indicating an excellent prognosis, while 29% and 39% of the 47 patients in the AMC and NMC category, respectively, have died of their disease. In the simplified system of Pedersen et al. the survival at 10 years for TMC patients decreased to 75% and no significant survival difference between the three groups could be demonstrated. As the prognosis for AMC proved to be worse compared to TMC and in fact was similar to NMC with values of 43% at 10 years in the Ridolfi classification, we find no reasons to maintain this category. We conclude that as long as no alternative and more easily applicable diagnostic method exists, pathologists should still apply the Ridolfi criteria on these tumours with medullary features leaving two diagnostic possibilities: TMC or NMC (i.e. poorly differentiated ductal carcinoma). Only lesions that fulfil all six criteria without any doubt should be diagnosed as TMC, thus avoiding overdiagnosis and a resulting risk of undertreatment.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We investigated the relationship between immunohistochemical estimates of proliferative activity and expression of bcl-2 protein and mutant p53 protein in 23 cases of soft tissue sarcoma. Furthermore, the reproducibility of estimates of proliferative activity was analysed and correlations between the variables and with mitotic score were investigated. Proliferative activity was assessed by use of monoclonal antibody MIB-1 and staining for iododeoxyuridine (IdUrd), and evaluated in multiple, random, systematically sampled fields of vision. MIB-1 indices were higher than those of IdUrd but for each case the two values were positively correlated (r = 0.78). The MIB-1 index correlated positively with mitotic score (2P 〈 0.001) and malignancy grade (2P = 0.001). The intra-observer reproducibility of the MIB-1 and IdUrd indices were excellent (r = 0.98 and r = 0.90, respectively). p53 expression was detected in 43% and strong bcl-2 expression was present in 57% of the studied cases. Expression of p53 and bcl-2 were not significantly correlated to proliferative activity or the histological features. We conclude, that the MIB-1 index is a reliable and reproducible estimate of proliferative activity and might improve the accuracy of conventional malignancy grading of soft tissue sarcomas. Furthermore, the results indicate that neither mutant p53 protein nor bcl-2 oncogene alone are sufficient to induce increased proliferation in these sarcomas.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To evaluate the prognostic value of tumour proliferative activity, p53 accumulation and bcl-2 expression in a retrospective series of 216 patients with soft tissue sarcomas (STS).〈section xml:id="abs1-2"〉〈title type="main"〉Methods and resultsThe immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was assessed by use of the monoclonal antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. The percentage of proliferating cells (the MIB-1 index) ranged between 1% and 85% (median 12%). A significant increase in mean MIB-1 index was seen with increasing histological malignancy grade. Variation in the incidence of p53 accumulation and bcl-2 positivity among different histological subtypes was observed. p53 accumulation was frequent in synovial sarcomas and leiomyo- and rhabdomyosarcomas, whereas bcl-2 preferentially was expressed in synovial sarcomas. Univariate analysis identified patient age, tumour size, histological grade of malignancy, MIB-1 index and p53 accumulation as significant prognostic parameters. Multivariate Cox analysis, including tests for interaction terms between histological subtypes and MIB-1 index, showed independent prognostic effect of MIB-1 index and tumour size in patients with high-grade tumours of other subtypes than malignant fibrous histiocytoma (MFH).〈section xml:id="abs1-3"〉〈title type="main"〉ConclusionsHistopathological malignancy grading is the most important single prognostic factor for overall survival in STS, but estimation of MIB-1 index is useful for identifying the least favourable subgroup of high grade STS of other subtypes than MFH, for whom adjuvant therapy may be indicated.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The pathogenetic role of autoantibodies in multiple sclerosis (MS) is uncertain. CD5+ B cells commonly produce autoantibodies, but CD5 expression has also been implicated in B-cell tolerance. We studied B-cell subsets, anti-myelin protein antibody-secreting cells in cerebrospinal fluid (CSF) and a panel of serum autoantibodies in patients with clinically isolated syndromes (CIS), suggestive of MS and patients with clinically definite MS (CDMS). Patients with CDMS had a higher percentage of CD5– B cells in CSF than did control subjects (P = 0.02). CIS patients with immunoglobulin G (IgG) oligoclonal bands in CSF or multiple lesions on magnetic resonance imaging (MRI) had a higher percentage of CD5– B cells in CSF than did the remaining CIS patients (P = 0.03). The percentage of CD5– and CD80+ B cells correlated positively and the percentage of CD5+ B cells correlated negatively with the number of CSF cells secreting anti-myelin basic protein (anti-MBP) antibodies. The prevalence of serum autoantibodies was comparable in the three patient groups. We conclude that intrathecal expansion of CD5– B cells appears to be more characteristic in MS patients, and CD5+ B cells may be associated with a lower prevalence of anti-myelin antibody production.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Fetal cerebral metabolism changes during development. The normal fetal metabolic rate must be known to evaluate pathophysiological changes. Therefore, we determined the regional cerebral glucose consumption in the fetal guinea pig. This required the application of the 2-deoxyglucose method to this species. We measured both the transfer coefficients of deoxyglucose and glucose between the maternal arterial plasma and the fetal brain and the lumped constant in chronically prepared undisturbed guinea pig dams using a three-compartment model. Furthermore, the ratio between the initial clearances of deoxyglucose and glucose between the maternal arterial plasma and the fetal brain and the ratio between the phosphorylation coefficients of these substrates in the fetal brain were determined. The total cerebral glucose consumption measured by the deoxyglucose method (10 ± 1.2 µmol/100 g/min) was similar to that calculated from the glucose concentration and the phosphorylation coefficient of glucose in the cerebrum (10 ± 0.4 µmol/100 g/min). We conclude that the 2-deoxyglucose method is applicable to the guinea pig, and we further conclude that in the fetal guinea pig cerebral glucose consumption is 10 times lower than that in the adult.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The present study evaluates how four key amino acid residue positions (− 4′ to − 1′) within the M1–M2 linker of the GABAA receptor β subunit influences ion selectivity of a cation-conducting GABA receptor. Cation selectivity was found to be highly dependent on the side-chains of the amino acid residues present. The critical factor for cation selectivity was the presence of a negatively charged Glu or Asp residue in the − 1′ position. Receptors containing the neutral amino acids Gln or Asn or a positively charged Arg residue were anion selective. In the presence of a −1′ Glu residue, the amino acids in adjacent positions were also found to be important determinants of cation selectivity. Moreover, the length of the M1–M2 linker as well as the presence of a Pro residue within this segment also affected ion selectivity, suggesting that the local environment and three-dimensional position of the −1′ Glu are essential determinants of cation permeation. Conversely, no specific amino acid residues were found to be essential for anion selectivity, suggesting that the basic architecture of the selectivity segment of this class of receptor channels is optimally suited for anion conduction.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Parkin is a ubiquitin ligase that facilitates proteasomal protein degradation and is involved in a common autosomal recessive form of Parkinson's disease. Its expression is part of the unfolded protein response in cell lines where its overexpression protects against unfolded protein stress. How parkin expression is regulated in brain primary cells under stress situations is however, less well established. Here, the cellular and subcellular localization of parkin under basal conditions and during unfolded protein stress was investigated in primary cultures of rat astrocytes and hippocampal neurons. Immunofluorescense microscopy and biochemical analysis demonstrated that parkin is mainly associated with the endoplasmic reticulum (ER) in hippocampal neurons while it is associated with Golgi membranes, the nuclei and light vesicles in astrocytes. The constitutive parkin expression was high in neurons as compared with astrocytes. However, unfolded protein stress elicited a selective increase in astrocytic parkin expression and a change in distribution, whereas neuronal parkin remained largely unmodified. The cell specific differences argue in favour of different cellular binding sites and substrates for the protein and a pathogenic role for astrocytes in Parkinson's disease caused by parkin dysfunction.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...