The von Willebrand factor-binding protein (vWbp) of Staphylococcus aureus is a coagulase

Staphylococcus aureus encodes a secreted von Willebrand factor-binding protein (vWbp) of 482 amino acids. The N-terminal part of this protein is homologous to staphylocoagulase and therefore we investigated whether vWbp has coagulating activity. Recombinant vWbp was shown to coagulate human and porcine plasma efficiently, but was less active against plasma from other species. The coagulation efficiency was concentration dependent, and could be inhibited by specific antibodies against vWbp. Furthermore, the species-specific coagulation by vWbp depended on the interaction with prothrombin. This interaction also resulted in specific cleavage of vWbp, releasing the C-terminal part from the coagulating domain.     

Metabolic fingerprinting of rat urine by LC/MS Part 1. Analysis by hydrophilic interaction liquid chromatography-electrospray ionization mass spectrometry

Complex biological samples, such as urine, contain a very large number of endogenous metabolites reflecting the metabolic state of an organism. Metabolite patterns can provide a comprehensive signature of the physiological state of an organism as well as insights into specific biochemical processes. Although the metabolites excreted in urine are commonly highly polar, the samples are generally analyzed using reversed-phase liquid chromatography mass spectrometry (RP-LC/MS). In Part 1 of this work, a method for detecting highly polar metabolites by hydrophilic interaction liquid chromatography-electrospray ionization mass spectrometry (HILIC/ESI-MS) is described as a complement to RP-LC/ESI-MS. In addition, in an accompanying paper (Part 2), different multivariate approaches to extracting information from the resulting complex data are described to enable metabolic fingerprints to be obtained. The coverage of the method for the screening of as many metabolites as possible is highly improved by analyzing the urine samples using both a C(18) column and a ZIC-HILIC column. The latter was found to be a good alternative when analyzing highly polar compounds, e.g., hydroxyproline and creatinine, to columns typically used for reversed-phase liquid chromatography.     

Metabolic fingerprinting of rat urine by LC/MS Part 2. Data pretreatment methods for handling of complex data

Metabolic fingerprinting of biofluids like urine is a useful technique for detecting differences between individuals. With this approach, it might be possible to classify samples according to their biological relevance. In Part 1 of this work a method for the comprehensive screening of metabolites was described, using two different liquid chromatography (LC) column set-ups and detection by electrospray ionization mass spectrometry (ESI-MS). Data pretreatment of the resulting data described in is needed to reduce the complexity of the data and to obtain useful metabolic fingerprints. Three different approaches, i.e., reduced dimensionality (RD), MarkerLynx, and MS Resolver, were compared for the extraction of information. The pretreated data were then subjected to multivariate data analysis by partial least squares discriminant analysis (PLS-DA) for classification. By combining two different chromatographic procedures and data analysis, the detection of metabolites was enhanced as well as the finding of metabolic fingerprints that govern classification. Additional potential biomarkers or xenobiotic metabolites were detected in the fraction containing highly polar compounds that are normally discarded when using reversed-phase liquid chromatography.     

Factors related to health-related quality of life in ankylosing spondylitis,overall and stratified by sex

Background

Ankylosing spondylitis (AS) begins early in life and often leads to reduced physical function, but less is known about the impacts it has on health-related quality of life (HRQoL). The aims of this study were to assess HRQoL using the Short Form-36 (SF-36) in a cohort of patients with AS compared with controls and to examine associations between SF-36 scores and spinal radiographic changes, physical function, disease activity and demographic data overall and stratified by sex.

Methods

A cohort of patients with AS from Western Sweden were assessed using the Modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) with spinal radiographs, clinical examination and questionnaires, including the Bath Ankylosing Spondylitis Metrology Index, Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Patient Global (BASG) and SF-36. Each patient’s SF-36 results were compared with those of five age-matched and sex-matched persons (n?=?1055) from the SF-36 Swedish normative population database. Associations between SF-36 physical component summary (PCS) and mental component summary (MCS) scores and disease-related and demographic factors were investigated using univariate and multivariable ogistic regression analyses with PCS and MCS below/above their respective median values as dependent variables.

Results

A total of 210 patients, age (median, IQR) 49.0 (21.2) years, symptom duration 24.0 (21.0) years, men 57.6% and HLAB27 87.1% were included. Patients with AS scored significantly lower (p?<?0.001) compared to controls in all SF-36 domains and component summaries; PCS 42.4 (14.5) in AS versus 52.4 (11.8) in controls and MCS 47.9 (20.0) in AS versus 54.1 (10.1) in controls. Both men and women scored significantly lower in PCS compared with MCS. Multivariable logistic regression analyses revealed that living without a partner (OR 2.38, 95% CI 1.00–5.67), long symptom duration (year in decade OR 1.66, 95% CI 1.16–2.37), higher BASFI (OR 1.98, 95% CI 1.46–2.70) and ASDAS ≥?2.1 (OR 3.32, 95% CI 1.45–7.62) were associated with worse PCS, while living without a partner (OR 3.04, 95% CI 1.34–6.91), fatigue (visual analogue scale for global fatigue greater than the median (OR 6.36, 95% CI 3.06–13.19) and ASDAS ≥?2.1 (OR 2.97, 95% CI 1.41–6.25) with worse MCS. Some differences between sexes were observed in the results.

Conclusions

The patients with AS had significantly lower HRQoL compared with controls. PCS was more affected compared to MCS in both sexes. Both disease-related and demographic factors were associated with HRQoL, partly overlapping for PCS and MCS. Factors associated with HRQoL showed some differences between sexes. By modifying factors, such as ASDAS-CRP and fatigue, HRQoL may potentially be improved.

Trial registration

ClinicalTrials.gov, NCT00858819. Registered on 9 March 2009. Last updated on 28 May 2015.

     

Tissue Plasminogen Activator Coating on Implant Surfaces Reduces Staphylococcus aureus Biofilm Formation

Staphylococcus aureus biofilm infections of indwelling medical devices are a major medical challenge because of their high prevalence and antibiotic resistance. As fibrin plays an important role in S. aureus biofilm formation, we hypothesize that coating of the implant surface with fibrinolytic agents can be used as a new method of antibiofilm prophylaxis. The effect of tissue plasminogen activator (tPA) coating on S. aureus biofilm formation was tested with in vitro microplate biofilm assays and an in vivo mouse model of biofilm infection. tPA coating efficiently inhibited biofilm formation by various S. aureus strains. The effect was dependent on plasminogen activation by tPA, leading to subsequent local fibrin cleavage. A tPA coating on implant surfaces prevented both early adhesion and later biomass accumulation. Furthermore, tPA coating increased the susceptibility of biofilm infections to antibiotics. In vivo, significantly fewer bacteria were detected on the surfaces of implants coated with tPA than on control implants from mice treated with cloxacillin. Fibrinolytic coatings (e.g., with tPA) reduce S. aureus biofilm formation both in vitro and in vivo, suggesting a novel way to prevent bacterial biofilm infections of indwelling medical devices.     

Distribution of Penicillin G in Serum and Tissue Cage Fluid in Cattle*

The penetration of penicillin into tissue cage fluid (TCF) in calves was studied after intravenous and intramuscular injection. The penicillin concentrations in TCF were lower than in serum and maximum was reached much later. Intravenous injection of benzyl-penicillin gave significantly higher levels in TCF than intramuscular injection. The penetration after procaine penicillin was very slow. The results showed that the serum peak rather than the area under curve determines the penetration of penicillin. Repeated intramuscular injections of benzylpenicillin and procaine penicillin caused an accumulation of penicillin in TCF. Similar levels were however reached by one single intravenous injection. The clinical counterparts to the used tissue cage model are abscesses. It was concluded that if high penicillin concentration are desireable in such foci, the drug must be given in a way that gives as high serum peaks as possible.     

In situ localization of transthyretin-mRNA in the adult human liver,choroid plexus and pancreatic islets and in endocrine tumours of the pancreas and gut

Summary In situ hybridization with ³⁵S-labeled single stranded RNA probes was used on sections from formaldehyde-fixed and paraffin-embedded tissue specimens to provide semiquantitative data on the occurrence of transthyretin(TTR)-mRNA in human liver, choroid plexus and pancreatic islets as well as in 15 endocrine tumours of the pancreas and gut. A monoclonal antibody to TTR was used for immunocytochemical identification of the protein in consecutive sections.The amount of TTR-mRNA in hepatocytes was found to be much less than that in epithelial cells of the choroid plexus. Glucagon cells of the pancreatic islets were also specifically labeled and the level of TTR-mRNA in these cells was intermediate between that of hepatocytes and choroid plexus epithelial cells. Four glucagonomas, one malignant insulinoma and two midgut carcinoids were shown to contain TTR-mRNA. The in situ labeled cells were also found to be TTR immunoreactive. These findings present the first conclusive evidence for TTR synthesis in pancreatic islets and in endocrine tumours. They also establish that the high serum concentration of TTR found in some patients with endocrine tumours (notably glucagonomas) is most likely due to tumour production of TTR.     

Improvement of renal preservation by adding lidoflazine to University of Wisconsin solution. An experimental study in the rat.

The purpose of this study was to investigate the possibility of improving the organ preservation properties of the University of Wisconsin (UW) solution by adding the calcium entry blocker lidoflazine. We also investigated the possibility of decreasing the cold ischemia and reperfusion damage by pretreatment with lidoflazine of the donor and/or recipient. The protective effects of lidoflazine treatment were estimated by measuring the amount of trapped erythrocytes in the rat renal medulla after 48 h of cold storage, subsequent transplantation, and 20 min of reperfusion. Lidoflazine (20 mg/liter) added to the UW solution decreased the amount of erythrocyte trapping from 14.8 +/- 3.1% in controls to 8.6 +/- 1.7% (P less than 0.01). The flow rate of the flush-out solution during the harvesting procedure was also significantly (P less than 0.01) increased when lidoflazine was included in the UW solution (1.10 +/- 0.21 ml/min vs 0.75 +/- 0.22 ml/min). Administration of lidoflazine (0.28 mg/kg body wt) to the donor and/or the recipient did not further reduce the postischemia/reperfusion damage as estimated by the degree of erythrocyte trapping. In conclusion, the results indicate that the preservation properties of the UW solution can be significantly improved by adding lidoflazine to the solution.     

Red cell H-deficient,salivary ABH secretor phenotype of Reunion island. Genetic control of the expression of H antigen in the skin

Based on the genetic model proposing thatH andSe are two structural genes, we predicted that the red cell H-deficient, salivary ABH secretor phenotype should be found on Reunion island, where a large series of H-deficient non-secretor families have been previously described. Two such Reunion individuals are now reported. POU [A_h, Le(a–b+), secretor of A, H, Le^a and Le^b in saliva] and SOU [O_h, Le(a–b+), secretor of H, Le^a and Le^b in saliva]. Both are devoid of H -2-fucosyltransferase activity in serum. In addition, the preparation of total non-acid glycosphingolipids from plasma and red cells of POU revealed the type 1ALe^b heptaglycosylceramide and small amounts of the monofucosylated type 1 A hexaglycosylceramide. Both glycolipids possess an H structure probably synthesised by the product of theSe gene. No other blood group A glycolipids, with types 2, 3 or 4 chains, normally present in the presence of the product of theH gene, were found on red cells or plasma of POU.TheH,Se andLe genetic control of the expression of ABH and related antigens in different tissue structures of the skin is described in 54 H-normal individuals of known ABO, secretor and Lewis phenotypes; in one red cell H-deficient salivary secretor (SOU); and in one H-deficient non-secretor (FRA). Sweat glands express ABH under the control of theSe gene. Sweat ducts express ABH under the control of bothH andSe genes and Lewis antigens under the control ofLe and bothH andSe genes. Epidermis, vascular endothelium and red cells express ABH under the control of theH gene. The products ofH andSe genes are usually expressed in different cells. However, the results illustrate that in some structures, like the epithelial cells of sweat ducts, both the products ofH andSe genes can contribute to the synthesis of the same Le^b structure.     

Activities of free radical and DNA turn-over enzymes in cancerous and non-cancerous human brain tissues

Activities of adenosine deaminase (ADA), 5′ nucleotidase (5′NT), xanthine oxidase (XO), guanase (GUA), total superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) enzymes were measured in cancerous brain tissues from 48 patients. The results were compared with those of the control brain tissues from 17 subjects. Important differences were found between enzyme activities of control brain tissues and those of tumoral tissues.

There were important intracorrelations between some of the enzyme activities in both neoplastic and control brain tissues. The correlations exhibited significant differences between control group and patient groups, indicating disordered enzymatic relations in the cancerous brain tissues.

The results suggest that enzymatic make-up relating to free radical and purine metabolism shows great differences between cancerous and non-cancerous brain tissues. Similar diversity is also present between various types of cancerous brain tissues. This implies that enzymatic make-up of the tissues also depends on the cancer type. We thus suggest that the results obtained from this kind of experimental studies should be evaluated individually for the tissue analyzed taking the cancer type into consideration without making general evaluations.