Immunochemical studies of the lipopolysaccharides of Hafnia alvei PCM 1219 and other strains with the O-antigens containing D-glucose 1-phosphate and 2-deoxy-2-[(R)-3-hydroxybutyramido]-D-glucose

Introduction:   Hafnia alveiis the only species of the genus Hafnia, which belongs to the family of Enterobacteriaceae. These Gram-negative bacteria are commonly distributed in the natural environment and are often the cause of human opportunistic infections. Their lipopolysaccharides (LPSs) are important surface antigens which are responsible for the serological specificity and numerous cross-reactions with other enterobacterial genera. So far, 29 different O-polysaccharide (OPS, O-antigen) structures in Hafnias LPSs have been established and for some of them the molecular basis of the serological activity has been elucidated. Materials and Methods:  OPS from H. alvei strain PCM 1219 was obtained by mild acid hydrolysis of the LPS followed by gel permeation chromatography of carbohydrate material on Sephadex G-50 column. The polysaccharide structure was determined using chemical methods as well as ¹³C NMR and ¹H NMR spectroscopy. For serological studies, SDS-PAGE, immunoblotting, and passive hemagglutination tests were used. Results:  The serological studies revealed a cross-reactivity of the LPSs of H. alvei PCM 1219 and a group of H. alvei strains with an O-antigen containing D-glucose 1-phosphate and [(R)-3-hydroxybutyramido]-D-glucose. The following structure of the OPS was established: where Acyl stands for (R)-3-hydroxybutyryl and the degree of O-acetylation is ~70%. The structure of the core oligosaccharide was found to be typical of the genus Hafnia. Conclusions:  Based on the OPS structure and serological results it was concluded that H. alvei strain PCM 1219 should be classified in the same serogroup as the H. alvei type strain ATCC 13337 and five other strains containing D-glucose 1-phosphate and 2-deoxy-2-[(R)-3-hydroxybutyramido]-D-glucose in their O-antigens. Received: 2007.10.10, Accepted: 2008.06.30     

Synthesis and properties of well-defined multiblock copolymers: poly(4,4′-isopropylidenediphenyl carbonate)-block-polystyrene

Well-defined poly(4,4′-isopropylidenediphenyl carbonate)-block-polystyrene multiblock copolymers, PC-b-PS, were prepared by condensation of PC prepolymers having chloroformyl end-groups with PS prepolymers having hydroxyl end-groups. Both prepolymers had narrow molecular weight distribution (PC prepolymer: M?_w/M?_n ≤ 1,31, PS prepolymer: M?_w/M?_n ≤ 1,03). The course of the polycondensation reaction depends on the molecular weight of the prepolymers used as substrates. After fractionation, the obtained multiblock copolymers are homogeneous in chemical composition and have a narrow molecular weight distribution. The mechanical properties of the copolymers depend on the weight fraction of the PS blocks. All copolymers exhibit two glass transition temperatures, close to those of the parent homopolymers.     

Dilute solution properties of well-defined multiblock copolymers: poly(4,4′-isopropylidenediphenyl carbonate)-block-polystyrene

Light scattering, osmometric and viscometric studies were carried out with dilute solutions of well-defined poly(4,4′-isopropylidenediphenyl carbonate)-block-polystyrene multiblock copolymers, PC-b-PS, in non-selective and selective solvent systems. The influence of copolymer composition, numbers and lengths of blocks in the copolymer chain and type of solvent used on the dilute solution properties, conformation of the investigated multiblock copolymers and on some thermodynamic parameters are discussed. The intrinsic viscosity [η], the unperturbed dimension 〈R₀²〉/M and the second virial coefficient A₂ are larger in non-selective solvents than expected from the averaged values of the parent homopolymers. In benzene, a selective solvent for polystyrene, formation of micelles is possible.     

Synthesis and structural studies of new copolyimides 2. Influence of pyromellitimide rings on copolymer structure

The reaction of pyromellitic dianhydride (1,2 : 4,5-benzenetetracarboxylic dianhydride) ( 1 ) with L - and D -alanine ( 2 L ) and ( 2 D ) leads to new monomers which were used to synthesize new copolymers. These copolymers were obtained as a product of the condensation of optical isomers of bis[N-(1-chloroformylethyl)]pyromellitimides (CFEP) with poly(ethylene glycol) PEG-2000 ( 5 ). The effect of monomer structure on the structure and thermal properties of the polymers was studied using X-ray diffraction, differential scanning calorimetry and thermogravimetry. The copolymers were compared with similar copolyimides obtained previously from bis(N-chloroformylmethyl)pyromellitimide and poly(ethylene glycol), PEG 2000. The dominating effect of poly(ethylene glycol) comonomer on the crystallinity, structure and thermal stability of these new copolymers is proven.     

Association of c.802C>T polymorphism of NOD2/CARD15 gene with the chronic gastritis and predisposition to cancer in H. pylori infected patients

This paper shows analysis of the association of the 802C>T polymorphism of the NOD2/CARD15 gene with the occurrence of the chronic inflammation of the gastric mucosa associated with the Helicobacter pylori infections, development of intestinal metaplasia and dysplasia and, in the result of this, gastric cancer. Genomic DNA samples were extracted from paraffin blocks of gastric mucosal biopsies and from peripheral blood. H. pylori infection was confirmed by histological analysis and urease test. Pyrosequencing of 802C>T polymorphism of the NOD2/CARD15 gene was performed for H. pylori infected patients (131) and population group (100). Analysis of the NOD2/CARD15 gene showed that frequency of the T allele was significantly higher (32.8%) in the group of patients in comparison with the population group (18.1%), with the relative risk of 1.8. In the patient group, the frequency of the CC genotype was 51.1%, CT 32.1% and TT 16.8% (relative risk: 0.7, 1.1 and 4.2, respectively), while in the population group it was 69.0%, 25.7% and 5.3% (relative risk: 1.0, 0.9 and 1.3, respectively). The increasing frequency of the T allele and CT and TT genotypes in the patients with increasingly deeper changes in the gastric mucosa becomes apparent. Our findings suggest that polymorphism 802C>T is associated with changes in gastric mucosa and plays a significant role in the initiation and the progression of carcinogenesis. The number of observed mutations in gastric mucosa correlated with severity of disease.     

Anionic polymerization of exo-3,4,5-trithiatetracyclo[5.5.1.O2,6.O8,12]tridec-10-ene (dicyclopentadiene trisulfide)

The anionic polymerization of exo-3,4,5-trithiatetracyclo[5.5.1.O^2,6.O^8,12]tridec-10-ene ( 1 ) in bulk and/or in aromatic solvents (benzene, toluene) was studied. The polymerization was initiated with sodium benzenethiolate (sodium cation complexed with dibenzo-18-crown-6). Polymers with high-molecular weights were obtained (M _n ≈ 10⁵, osmometrically). The polymerization was found to be living and reversible; the equilibrium monomer concentration increases with the temperature. The ceilling temperature was estimated as 167°C. The thermodynamic data of the polymerization in toluene was determined and compared with those of the polymerization of exo-3,4,5-trithiatricyclo[5.2.O^2,6]decane. The standard enthalpy ΔH = ?(6,6 ± 0,6)kJ · mol ¹ and entropy ΔS = ?(29,3 ± 2,1)J · mol ¹ · K ¹ of the polymerization of 1 were evaluated from the temperature dependence of the equilibrium monomer concentration, determined dilatometrically.     

Evaluation of tracheal stenosis: comparison between computed tomography virtual tracheobronchoscopy with multiplanar reformatting,flexible tracheofiberoscopy and intra-operative findings

The aim of the study was to evaluate and compare various helical CT display modes [virtual endoscopy (VE)] and multiplanar reformations (MPR), conventional flexible tracheobronchoscopy (FT) and intra-operative (IO) findings in patients with tracheal stenosis and to analyze the advantage of MPR and VE in diagnosis and treatment planning and in postoperative follow-up. Thirty-seven patients with tracheal stenosis underwent standard neck and chest CT followed by MPR and VE. Results were correlated with the results of FT and IO findings. Thirty-three of the 37 stenoses were correctly graded and measured adequately using VE. Complete correlation among CT, fiberoptic tracheoscopy, and surgery of stenosis grading, stenosis length and length of planned resection segment of the trachea was noted between 33 of 37 patients with tracheal stenosis. Correlation between VE and IO was noted in 35 of 37 patients and between FT and VE was noted in 33 of 37 patients with tracheal stenosis. The sensitivity of VE was 94–97%, specificity was 100% with comparison to IO findings. The sensitivity and accuracy of MPR was 86–89% and specificity was 100% with comparison to FT findings. The results of the study indicate that VE is an excellent, consistent, and objective technique. VE with MPR is very useful in diagnostic evaluation and treatment planning in patients with tracheal stenosis.     

Using qualitative methods to inform the design of a decision aid for people with advanced cystic fibrosis: The InformedChoices CF patient decision aid

ObjectiveTo assess information needs of adults with Cystic Fibrosis and their families toward designing a patient decision aid about invasive mechanical ventilation (IMV) and lung transplant.MethodsFocus groups and in-depth interviews explored participants’ knowledge, prior clinical conversations, and decisions about IMV and lung transplant. Interviews and focus groups were recorded and transcribed for analysis.ResultsN = 24 participants were recruited. Themes identified were: prior communication with clinicians, decision-making process, and living with CF. Participants having prior conversations with CF clinicians regarding: lung transplant (N = 17/74%), and IMV (N = 3/13%). Most 15(65%) felt it was important to hear patients’ real-life experience, others (3/13%) relied on their CF doctors for information. Most people (16/70%) believed hearing prognosis was helpful, but 5(22%) found this information frightening. High degrees of social isolation and a desire for more interaction with other CF adults were found.ConclusionsQualitative methods helped identify areas important for decision making about IMV and LT for CF adults. Future directions include usability and feasibility testing of the decision aid.Practice implicationsBecause IMV is rarely discussed with CF adults, clinicians might approach this topic, as with transplant, as lung function begins to decline. CF-care teams should also foster CF patient-level information exchange.     

Pseudomonas aeruginosa biofilm is a potent inducer of phagocyte hyperinflammation

Objective

Pseudomonas aeruginosa effectively facilitate resistance to phagocyte killing by biofilm formation. However, the cross talk between biofilm components and phagocytes is still unclear. We hypothesize that a biofilm provides a concentrated extracellular source of LPS, DNA and exopolysaccharides (EPS), which polarize neighbouring phagocytes into an adverse hyperinflammatory state of activation.

Methods

We measured the release of a panel of mediators produced in vitro by murine neutrophils and macrophages exposed to various biofilm components of P. aeruginosa cultures.

Results

We found that conditioned media from a high biofilm-producing strain of P. aeruginosa, PAR5, accumulated high concentrations of extracellular bacterial LPS, DNA and EPS by 72 h. These conditioned media induced phagocytes to release a hyperinflammatory pattern of mediators, with enhanced levels of TNF-α, IL-6, IL12p40, PGE₂ and NO. Moreover, the phagocytes also upregulated COX-2 and iNOS with no influence on the expression of arginase-1.

Conclusions

Phagocytes exposed to biofilm microenvironment, called by us biofilm-associated neutrophils/macrophages (BANs/BAMs), display secretory properties similar to that of N1/M1-type phagocytes. These results suggest that in vivo high concentrations of LPS and DNA, trapped in biofilm by EPS, might convert infiltrating phagocytes into cells responsible for tissue injury without direct contact with bacteria and phagocytosis.

     

Sclerosing stromal tumor of the ovary in a 30-year-old woman. A case report and review of the literature

Sclerosing stromal tumor of the ovary (SST) is an extremely rare neoplasm occurring predominantly in the second and third decades of life. It is a distinct benign neoplasm that differs from fibromas, thecomas, luteinized tumors and lipoid cell tumors. It presents most often with non-specific symptoms. We describe the case of a 30-year-old woman who developed menstrual irregularities and pelvic pain. She was diagnosed and treated operatively at our Department. During surgery, a benign tumor was found in the right ovary. Light microscopic and ultrastructural study confirmed the diagnosis of sclerosing stromal tumor of the ovary.