bluuebunny/crossref_metadata_2025 huggingface dataset:
Urea, Fluorofamide, and Omeprazole Treatments Alter Helicobacter Colonization in the Mouse Gastric Mucosa
Authors: Aristoteli Lina Panayiota , O’Rourke Jani L. , Danon Stephen , Larsson Hakan , Mellgard Bjorn , Mitchell Hazel , Lee Adrian
Published: September 2006

Background:  Helicobacter pylori is a causative agent of gastric and duodenal ulcers and gastric cancer. Its urease enzyme allows survival in acid conditions and drives bacterial intracellular metabolism. We aimed to investigate the role of urease in determining the intragastric distribution of Helicobacter species in vivo.

Materials and Methods:  The C57BL/6 mouse model of gastritis was used for infection with Helicobacter felis (CS1) or H. pylori (SS1). Urease‐modulating compounds urea and/or fluorofamide (urease inhibitor) were administered to mice over 7 days. Concurrent gastric acid inhibition by omeprazole was also examined. Bacterial distribution in the antrum, body, antrum/body, and body/cardia transitional zones was graded “blindly” by histologic evaluation. Bacterial colony counts on corresponding tissue were also conducted.

Results:  Urease inhibition by fluorofamide decreased H. pylori survival in most gastric regions (p < .05); however, there were no marked changes to H. felis colonization after this treatment. There was a consistent trend for decreased antral colonization, and an increase in antrum/body transitional zone and body colonization with excess 5% or 6% (w/v) urea treatment. Significant reductions of both Helicobacter species were observed with the co‐treatment of urea and fluorofamide (p < .05). Collateral treatment with omeprazole did not alter H. pylori colonization patterns caused by urea/fluorofamide.

Conclusions:  Urease perturbations affect colonization patterns of Helicobacter species. Combined urea and fluorofamide treatment reduced the density of both Helicobacter species in our infection model.
Comparison of Repair Methods for Ceramic‐Fused‐to‐Metal Crowns
Authors: Özcan Mutlu , Van Der Sleen Jeroen M. , Kurunmäki Hemmo , Vallittu Pekka K.
Published: September 2006

Purpose: The objective of this study was to evaluate the effect of four repair methods on the fracture load of repaired ceramic‐fused‐to‐metal crowns.

Materials and Methods: Metal‐ceramic crowns were fractured, and the failure load was measured. The fractured metal‐ceramic crowns (n = 9) were assigned randomly to the following treatment groups: (1) hydrofluoric acid (9.5%) etching, (2) air‐particle abrasion (50 μm Al2O3), (3) silica coating (30 μm SiOx), and (4) the application of a layer of glass fiber‐reinforced composite (FRC) (thickness: 0.12 mm) on the repair surface. The crowns were repaired with a highly filled resin composite and subjected to 3 repair cycles (n = 27). All specimens were stored in water at 37°C for 24 hours and then thermocycled (6000 cycles, 5°C to 55°C). The fracture load values for final failure of intact and repaired crowns were measured with a universal testing machine, and failure types were recorded.

Results: No significant differences ( p > 0.05) were found between the final failure values for the groups treated with 9.5% hydrofluoric acid (376 N) and airborne particle abrasion with either Al2O3 (432 N) or SiOx (582 N) followed by silanization, respectively. Significantly, higher ( p < 0.0001) final failure values (885 N) were obtained with the use of the FRC layer when compared with the other repaired groups. There was no significant difference ( p > 0.05) between the final fracture load of intact crowns (872 N) and those repaired with FRC (885 N) (One‐way ANOVA with repeated measures, Bonferroni test). No significant difference in fracture loads was found between the 1st, 2nd, and 3rd repair cycles (558 N, 433 N, 485 N, respectively). Failure sites were predominantly at the alloy/veneering resin interface in Group 1; Groups 2 and 3 both showed more cohesive failures than Group 1. In the case of FRC, the failure pattern was exclusively cohesive between the two laminates of FRC layer.

Conclusions: The conditioning methods (Groups 1 to 3) of the repair surfaces did not show differences between each other; each resulted in mean fracture loads at lower levels than that of the intact crowns. Addition of an FRC layer increased the fracture load to the level of intact crowns. This suggests that the use of FRC in repairs of metal‐ceramic crowns might be a viable option.
The Effect of Fatigue Damage on the Force Required to Remove a Restoration in a Cement‐Retained Implant System
Authors: Kaar Darian , Oshida Yoshiki , Andres Carl J. , Barco M. Thomas , Platt Jeffrey A.
Published: September 2006

Purpose: To evaluate the luting agents and retentive forces before and after mechanical stressing.

Materials and Methods: Sample size N was 12 for each group, and 12 Cera‐One closed‐end gold cylinders were cemented with three types of luting cements (ImProv, UltraTemp, and TempBond). The force required to remove the gold cylinders from the abutments was determined with an MTS testing machine. After cleaning and recementing the cylinders, the samples were placed in the housings of an Alabama‐type three‐body wear machine and load of 110 N was applied to the gold cylinders at a frequency of 80 cycles/min for 50,000 cycles. Then each cylinder was pulled from its abutment and the force at which the failure occurred was recorded. The procedure was repeated with 300,000 cycles.

Results: Statistical analysis arising from two‐way ANOVA found that the forces required to remove the abutments were significantly different. The most retentive cement was ImProv. Before cyclic loading, on average, ImProv produced a retentive value 85% higher than that yielded by TempBond, and 25% higher than that of UltraTemp. The three cements were significantly different at each of the three cycle levels.

Conclusions: These results might suggest TempBond luting agent as the material of choice for provisional cementation because it allows easier removal of the prosthesis and maintains enough retention to prevent loosening of the restoration. The clinical implication is that the effect of cyclic load on the strength of the cements is different, an important factor in selection of a cement. ImProv had the highest retentive value before and after the two cycles, and TempBond had the lowest. UltraTemp had the highest percentage of retentive value lost. TempBond had no significant loss under loading even though initially it was the weakest.
Storage of red blood cells with improved maintenance of 2,3‐bisphosphoglycerate
Authors: Högman Claes F. , Löf Helena , Meryman Harold T.
Published: September 2006

BACKGROUND: During storage, red blood cells (RBCs) rapidly lose 2,3‐bisphosphoglycerate (2,3‐DPG) leading to an increase in the affinity for O2 and a temporary impairment of O2 transport. Recent clinical evaluations indicate that the quality of transfused RBCs may be more important for patient survival than previously recognized.

STUDY DESIGN AND METHODS: Glucose‐free additive solutions (ASs) were prepared with sodium citrate, sodium gluconate, adenine, mannitol, and phosphates at high pH, a solution that can be heat‐sterilized. CP2D was used as an anticoagulant. Additional CP2D was added to the AS to supply glucose. RBCs were stored at 4°C and assayed periodically for intracellular pH (pHi), extracellular pH, glucose, lactate, phosphate, ATP, 2,3‐DPG, hemolysis, and morphology.

RESULTS: Storage in 175 mL of the chloride‐free, hypotonic medium at a hematocrit (Hct) level of 59 to 60 percent resulted in an elevated pHi and the maintenance of 2,3‐DPG at or above the initial value for 2 weeks without loss of ATP. The addition of 400 mL of storage solution followed by centrifugation and removal of 300 mL of excess solution to a Hct level of 60 to 66 percent further reduced the chloride concentration, resulting in the maintenance of 2,3‐DPG for 4 weeks. Hemolysis was at 0.1 percent at 6 weeks.

CONCLUSION: Improvements in the maintenance of 2,3‐DPG were achieved with 175 mL of a chloride‐free storage solution with familiar additives at nontoxic concentrations to increase pHi. Adding, instead, 400 mL of storage solution followed by the removal of 300 mL reduced the chloride concentration, increasing the pHi and extending the maintenance of 2,3‐DPG to 4 weeks.
Development of models and detection methods for different forms of cytomegalovirus for the evaluation of viral inactivation agents
Authors: Jayarama Vasudevacharya , Marcello Jennifer , Ohagen Asa , Gibaja Veronica , Lunderville Douglas , Horrigan Jeff , Chapman John , Lazo Aris
Published: September 2006

BACKGROUND: Cytomegalovirus (CMV) is transmitted by transfusion of infected blood products and can cause serious diseases in specific risk groups. CMV can be present in infected blood as cell‐free virus (CFV), cell‐associated actively replicating virus (CAV), and cell‐associated latent virus (LV).

STUDY DESIGN AND METHODS: In vitro models for all three infectious forms of CMV and virus detection assays based on both tissue culture and polymerase chain reaction (PCR) were developed. The utility of the CMV model systems and assays were tested by validation studies of a novel pathogen inactivation agent, PEN110, for red blood cells.

RESULTS: Reproducible high titers of CFV and CAV were obtained by optimized tissue culture techniques for CMV‐infected MRC‐5 cells. An LV model was obtained with CMV‐infected THP‐1 cells and reactivation of virus replication by phorbol ester treatment. The model systems showed that PEN110 treatment is effective against all three forms of CMV as measured by tissue culture–based infectivity assays and a long‐range PCR method specific for detection of damage to CMV viral DNA.

CONCLUSION: This study describes model systems to the relevant forms of CMV in blood and detection assays that can be used to evaluate the efficacy of viral inactivation agents.
Clinical experience with a new apheresis filter that specifically depletes ABO blood group antibodies
Authors: Kumlien Gunilla , Ullström Lisbeth , Losvall Anita , Persson Lars‐Gunnar , Tydén Gunnar
Published: September 2006

BACKGROUND: Although living kidney donors are increasingly being used, in most centers, 30 to 40 percent of potential donors are being turned down due to ABO mismatch. A protocol for ABO‐mismatched kidney transplantation without splenectomy and with antigen‐specific adsorption of ABO antibodies instead of nonspecific plasmapheresis was therefore designed.

STUDY DESIGN AND METHODS: The immunosuppressive protocol used at the Department of Transplantation Surgery, Karolinska University Hospital, Stockholm, Sweden, together with relevant clinical data for 11 of the studied patients, have been described previously. The protocol called for immunoadsorption of ABO antibodies on Days −6, −5, −2, and −1 and on Days +2, +5, and +8. Patient plasma was recirculated through a new apheresis filter, the Glycosorb ABO column (Glycorex Transplantation AB), containing synthetic terminal trisaccharide A or B blood group antigen linked to a Sepharose matrix.

RESULTS: Since 2001, 15 patients, including 2 infants, have been successfully transplanted with ABO‐mismatched kidneys from living donors. The donor‐recipient blood groups were A1‐O (n = 5), A2‐O (n = 2), B‐O (n = 4), B‐A (n = 2), and A1B‐B (n = 2). ABO antibody titers at transplantation did not exceed immunoglobulin G 4 or immunoglobulin M 4 levels. No humoral rejections and no late rebound of ABO antibodies were observed. No adverse effects related to immunoadsorption treatment have been recorded.

CONCLUSION: It is concluded that ABO‐mismatched kidney transplantations can be successfully performed without splenectomy and that ABO antibodies can be effectively and safely depleted with the Glycosorb ABO column.
The use of autologous blood to improve exercise capacity after total hip arthroplasty: a preliminary report
Authors: Pilot Peter , Bols Esther M.J. , Verburg Aart D. , Bell Constant A.M.P. , Moonen Adrianus F.C.M. , Van Os Johannes J. , Koolen Jacques J. , Geesink Ruud G.T. , Kuipers Harm
Published: September 2006

BACKGROUND: Venesection of red blood cells in healthy well‐trained subjects decreased the maximum oxygen uptake parallel with the reduction in hemoglobin (Hb) level. Based on the large Hb decrease that is seen after total joint surgery, one could expect a decrease in performance as well. The purpose of this study was to investigate whether autologous blood enhanced performance on a bicycle ergometer in patients after total hip arthroplasty.

STUDY DESIGN AND METHODS: Nine patients scheduled for elective total hip arthroplasty in an accelerated stay program participated in a preoperative autologous blood donation (PABD) program. Weeks before the scheduled surgery, patients donated 4 units of blood and received standard erythropoietin treatment. Physical fitness was assessed during exercise test on a bicycle ergometer. Each patient was matched with three previously tested patients.

RESULTS: Patients in both groups were 69.0 years old (range, 66‐74 years vs. 61‐77 years). None of the patients had relevant cardiovascular abnormalities. On average patients received 3.3 units of blood because 3 units were not transfused. The PABD group showed a Hb decrease of 0.5 g per dL (4%) on the fourth postoperative day versus 4.4 g per dL (31%) in the control group. The decline in power output on Day 4 was significantly less in the PABD group compared with the control group (t test, p = 0.026).

CONCLUSION: From this pilot study it can be concluded that correction of the postoperative Hb decrease was associated with a lower decrease in maximum power output, compared to the control group. On Days 23 and 39, however, the difference in performance between the PABD group and control group had disappeared.
Case report and literature review: transient Inab phenotype and an agglutinating anti‐IFC in a patient with a gastrointestinal problem
Authors: Yazer Mark H. , Judd W. John , Davenport Robertson D. , Dake Louann R. , Lomas‐Francis Christine , Hue‐Roye Kim , Powell Vivien , Reid Marion
Published: September 2006

BACKGROUND: The Inab phenotype is a rare deficiency of all Cromer antigens. These antigens are carried on the decay‐accelerating factor (DAF, CD55) molecule that is attached to the red blood cell (RBC) membrane by a glycosylphosphatidylinositol (GPI) anchor. Although typically inherited, an acquired and transient form of the Inab phenotype also exists. A patient with the triad of transient Inab phenotype, a direct‐agglutinating anti‐IFC, and gastrointestinal (GI) abnormalities is reported.

CASE REPORT: An 18‐month‐old boy with gastroesophageal reflux disease requiring a feeding tube, milk and soy intolerance, and severe growth retardation, as well as vision and hearing deficits from cytomegalovirus infection, was identified when pretransfusion testing revealed a potent panagglutinin (titer > 2000 at 4°C). This antibody did not react with Dr(a–) and IFC RBCs, and the autocontrol was negative. The patient’s RBCs lacked CD55 by flow cytometric techniques but had normal levels of CD59 and antigens such as Yta and Emm, carried on GPI‐linked proteins, thus excluding paroxysmal nocturnal hemoglobinuria. Several months after initial detection, the anti‐IFC was virtually undetectable and his cells reacted weakly with anti‐IFC, anti‐Dra, and anti‐CD55. RBCs from the propositus’ parents and brother demonstrated normal CD55 and CD59 expression.

CONCLUSION: This is the first example of a direct‐agglutinating anti‐IFC. The cause of the transient depression in CD55 protein (and thus Cromer system antigens) and appearance of anti‐IFC remains unknown, as does the relationship between the patient’s GI system abnormalities and these serologic findings.
Antibodies against glutathione S‐transferase T1 in non–solid organ transplanted patients
Authors: Wichmann Ingeborg , Aguilera Isabel , Sousa José M. , Bernardos Angel , García Núñez Emilio J. , Vigil Eduardo , Magariño Rosario , Magariño Isabel , Torres Antonia , Núñez‐Roldán Antonio
Published: September 2006

BACKGROUND: This article describes the presence of antibodies against glutathione S‐transferase T1 (GSTT1) in a group of patients who never received a solid organ graft. These antibodies have been previously detected in liver and kidney transplant subjects with donor‐recipient mismatch for this enzyme at the genetic level. In liver‐grafted subjects, the appearance of these antibodies correlated with de novo immune hepatitis.

STUDY DESIGN AND METHODS: To obtain some insights in this phenomenon, the clinical records of these patients were reviewed, and the possible causes leading to the production of these antibodies and possible clinical consequences were analyzed.

RESULTS: The clinical situation of these patients was very heterogeneous, but they had in common the need for transfusions or a previous pregnancy. GSTT1 antigen is present in red blood cells, liver, kidney, and other tissues. Because the presence of the GSTT1‐null allele in seven of these patients has been demonstrated, it can be hypothesized that both GSTT1‐positive transfusions or pregnancy of a GSTT1‐positive fetus could induce these antibodies. Because the recipient is allele‐null, no adverse effects in the host are expected to occur. The longest follow‐up (5 years) shows no antibody‐derived diseases.

CONCLUSION: It is concluded that anti‐GSTT1 can appear in a context different from the previously published alloreactivity after liver and kidney transplantation, as a consequence of transfusions and pregnancies. So far, no adverse clinical outcomes in our patients have been observed.
A functional comparison of mature human dendritic cells prepared in fluorinated ethylene‐propylene bags or polystyrene flasks
Authors: Kurlander Roger J. , Tawab Abdul , Fan Yong , Carter Charles S. , Read Elizabeth J.
Published: September 2006

BACKGROUND: Fluorinated ethylene‐propylene (FEP) bags have been used instead of polystyrene (PS) flasks for ex vivo clinical‐scale production of human dendritic cells (DCs) to facilitate closed‐system recovery of these highly adherent cells. To assess the impact of DC culture on this nonadherent surface, the function of DCs generated in FEP and PS was compared.

STUDY DESIGN AND METHODS: Cell yield, phenotype, cytokine production, migration, and antigen‐presenting activity were measured in DCs prepared from peripheral blood monocytes in FEP bags or PS flasks with medium supplemented with serum, interleukin (IL)‐4, and granulocyte‐macrophage–colony‐stimulating factor for 5 days to induce DC differentiation and CD40L or poly(I:C) plus interferon‐γ to promote maturation.

RESULTS: DCs cultured in FEP or PS had comparable cell yield, viability, and CD83 and CCR7 expression. DCs generated in FEP, however, produced significantly less IL‐12 and IL‐10 during maturation, and differences persisted on rechallenge after harvest. FEP‐cultured DCs migrated spontaneously or in response to CCR7 ligand more actively than PS‐cultured DCs, but this difference was not significant. Mature DCs prepared in FEP and PS were equipotent in stimulating peptide‐specific CD8 T‐cell expansion in vitro.

CONCLUSION: FEP‐ and PS‐cultured DCs are similar in phenotype and in some functional measures, but FEP markedly reduces DC production of IL‐12 and IL‐10. This phenomenon presumably reflects intracellular changes linked to the absence of a surface for firm cell adherence. Given the importance of these cytokines in the immune response, these changes could have a significant impact on DC function in vivo.
Increased iron absorption during autologous blood donation supported by recombinant human erythropoietin therapy
Authors: Bovy Christophe , Baudoux Etienne , Salmon Jean Pol , Beguin Yves
Published: September 2006

BACKGROUND:  Recombinant human erythropoietin (rHuEPO) therapy improves the success of autologous blood (AB) donation programs before elective surgery. The aim of this study was to evaluate iron absorption during an AB donation program with or without rHuEPO.

STUDY DESIGN AND METHODS:  Thirty‐two patients were randomly assigned among placebo (Group 1) or 300 (Group 2) or 600 UI per kg rHuEPO (Group 3) on the first, second, and third donation visits. All patients also received daily oral iron (200 mg Fe+).

RESULTS:  The number of units collected in Group 3 was higher than in Group 1 (4.6 ± 0.5 vs. 3.6 ± 0.8 units; p < 0.01). Red blood cell (RBC) production increased in a rHuEPO dose–dependent manner. With rHuEPO, the RBC volume collected per unit presented a lower decrease with number of donated units than with placebo and was similar to that of homologous blood units. Storage iron did not influence the number of units collected, whereas circulating mobilizable iron was the limiting factor. Oral iron absorption increased in a rHuEPO dose–dependent manner (12‐fold with 600 UI/kg rHuEPO) and was proportional to erythropoietic activity.

CONCLUSION:  rHuEPO does not only improve the number of AB units collected but also their quality. Storage iron cannot meet marrow iron requirements, but rHuEPO strongly increased oral iron absorption in a dose‐dependent fashion through stimulation of erythropoietic activity.
High‐Permittivity Double Rare‐Earth‐Doped Barium Titanate Ceramics with Diffuse Phase Transition
Authors: Lu Da‐Yong , Toda Masayuki , Sugano Mikio
Published: September 2006

On the basis of Ti‐vacancy defect compensation mode, high‐permittivity La‐ and Ce‐doped barium titanate ceramics (BLTC) with perovskite structure, i.e., (Ba1−xLax)(Ti1−x/4−yCey)O3, wherex=0.01–0.05 andy=0.05, were prepared by conventional ceramic processing techniques. Dielectric characteristics, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and hysteresis loops were measured. Defect chemistry and diffuse phase transition (DPT) in BLTC are discussed. Co‐doping with the relatively smaller La3+ions at Ba sites and the relatively larger Ce4+ions at Ti sites in the BaTiO3host lattice resulted in a fine‐grained microstructure (0.8–1.1 μm), marked raising, and broadening of the Curie peak characteristic of DPT. The Curie temperature (TC) at 800 Hz decreased rapidly at a dramatic rate of −30°C/at.% La wheny=0.05. By means of co‐doping with La and Ce, this is the first time that highk“Y5V” ceramics (BLTC: 0.03≤x≤0.04,y=0.05) with ɛ′RT>10 000 over a frequency range of 1–100 kHz have been achieved in rare‐earth‐doped BaTiO3ceramics.
Synthesis and Characterization of Nano‐Composite Alumina–Titania Ceramic Membrane for Gas Separation
Authors: Ahmad A.L. , Othman M.R. , Idrus N.F.
Published: September 2006

A ceramic composite membrane was prepared using a commercial titania ceramic membrane coated by alumina oxide via a sol–gel technique where polyvinyl alcohol (PVA) was used as a binder. The characteristic of the membrane was analyzed in terms of the effect of PVA concentration and sintering temperature on viscosity, pore size, density, porosity and surface area of the membrane. Two vol% of PVA solution containing 4 g of PVA in 100 mL of water was adequate to achieve an appropriate porosity level to avoid cracks on the gel layer. Sol viscosity and pore size of the membrane essentially increased when the PVA concentration was increased. The density of the membrane increased as the sintering temperature increased. The porosity level however, decreased when the temperature was increased. The composite membrane was further characterized in terms of permeability of pure gas at low‐temperature region (301 K) where an experimental platform has been developed to perform the permeability studies.
Preservatives sensitivity in Israel: a 10‐year overview (1995–2004)
Authors: Zoller Lilach , Bergman Reuven , Weltfriend Sara
Published: September 2006

This study presents a 10‐year survey of 2285 patients tested to common preservatives in northern Israel. The demographic and clinical data were analysed using a revised MOAHLFA index. Patch testing was based on the International Contact Dermatitis Research Group (ICDRG) guidelines. 411 (18%) patients were found to have positive reactions to 1 or more preservatives. The most frequent allergens tested positively were thimerosal, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI), and formaldehyde. The reactions to MCI/MI remained stable around 1.7% throughout the years 1995–1998, with a significant increase to 3.7%–4% (P= 0.029) during 1999–2004. The reactions to formaldehyde remained low around 0.3% until 1999; however, a considerable increase throughout the years 2000–2004 was noted, with rates of 1.5%–1.9% (P= 0.028). The sensitivity rates for parabens, quaternium‐15, imidazolidinylurea, and diazolidinylurea were low and unchanged, mostly under 0.5%. As for methyldibromoglutaronitrile (MDBGN), sensitivity rates around 2% were detected for the years 1996 and throughout 2000–2004. Overall, this extensive survey showed a concerning increase in the sensitivity rates for MCI/MI, formaldehyde, and MDBGN.
Hydroperoxides form specific antigens in contact allergy
Authors: Bråred Christensson Johanna , Matura Mihály , Bäcktorp Carina , Börje Anna , Nilsson J. Lars G. , Karlberg Ann‐Therese
Published: September 2006

Concomitant positive reactions to colophonium, oxidized limonene, and/or oxidized linalool are recorded in patch test studies. The main allergens in these patch test mixtures are hydroperoxides, which form antigens by a radical pathway. Theoretically, concomitant reactions can be explained not only by concomitant sensitization or by true cross‐reactions but also by the hydroperoxides acting as oxidizing agents on skin proteins to form non‐specific antigens without hapten–protein binding. The aim of this study was to explore concomitant reactions and cross‐reactivity patterns among hydroperoxide haptens. We investigated whether individuals allergic to the main allergen in colophonium, 15‐hydroperoxyabietic acid, would also react to limonene hydroperoxide or linalool hydroperoxide. Only 1 of 29 individuals reacted to more than 1 hydroperoxide. The cross‐reactivity pattern among cumene hydroperoxide, limonene hydroperoxide, 1‐(1‐hydroperoxy‐1‐methylethyl) cyclohexene (cyclohexene hydroperoxide), and 15‐hydroperoxydehydroabietic acid was investigated in guinea‐pigs. No general cross‐reactivity was observed. Cross‐reactions between cumene hydroperoxide and cyclohexene hydroperoxide show that similarity in the overall structure and the way of antigen formation are needed. Quantum calculations were used to determine the formation energies of the intermediary radicals. We concluded that hydroperoxides form specific antigens and that formation of non‐specific antigens is unlikely. The concomitant patch test reactions described in the literature are best explained as a result of multiple sensitizations.
Association of Unexplained Infertility with Gonadotropin and Ovarian Antibodies
Authors: Shatavi Seerin V. , Llanes Brainard , Luborsky Judith L.
Published: September 2006

Problem  To determine the prevalence and characteristics of gonadotropin autoantibodies (GAB) associated with unexplained infertility, and to assess the relationship between ovarian autoantibodies (OVAB) and GAB.

Method of study  Ovarian antibodies and GABs in sera of patients with unexplained infertility (n = 53) and a comparison (population) group from a blood bank (n = 40) were detected by immunoassay. Patients with unexplained infertility had either no prior gonadotropin treatment (n = 15) or two or more gonadotropin cycles to induce ovulation (n = 38).

Results  The GABs were detected in 67% of women with treatment, 27% of women without treatment and 8% of women in the population. The GABs recognized follicle stimulating hormone (FSH) and luteinizing hormone (LH) and their alpha and beta subunits and to a lesser extent thyroid stimulating hormone (TSH) and prolactin. There was no significant difference in OVAB prevalence between gonadotropin treated or untreated women while GABs were significantly more frequent in gonadotropin treated women (P ≤ 0.01).

Conclusion  Gonadotropin antibodies may represent a separate marker of ovarian autoimmunity in unexplained infertility as they are correlated with OVAB and are present in patients not treated with gonadotropin. However, as a higher frequency of GAB is associated with gonadotropin treatment, patients with ovarian autoimmunity may tend to have an immune response to gonadotropins in addition to an endocrine response.
Selectins and glycosyltransferases in leukocyte rolling in vivo
Authors: Sperandio Markus
Published: September 2006

Leukocyte rolling is an important step for the successful recruitment of leukocytes into tissue and occurs predominantly in inflamed microvessels and in high endothelial venules of secondary lymphoid organs. Leukocyte rolling is mediated by a group of C‐type lectins, termed selectins. Three different selectins have been identified – P‐, E‐ and L‐selectin – which recognize and bind to crucial carbohydrate determinants on selectin ligands. Among selectin ligands, P‐selectin glycoprotein ligand‐1 is the main inflammatory selectin ligand, showing binding to all three selectins under in vivo conditions. Functional relevant selectin ligands expressed on high endothelial venules of lymphoid tissue are less clearly defined at the protein level. However, high endothelial venule‐expressed selectin ligands were instrumental in uncovering the crucial role of post‐translational modifications for selectin ligand activity. Several glycosyltransferases, such as core 2 β1,6‐N‐acetylglucosaminyltransferase‐I, β1,4‐galactosyltransferases, α1,3‐fucosyltransferases and α2,3‐sialyltransferases have been described to participate in the synthesis of core 2 decorated O‐glycan structures carrying the tetrasaccharide sialyl Lewis X, a carbohydrate determinant on selectin ligands with binding activity to all three selectins. In addition, modifications, such as carbohydrate or tyrosine sulfation, were also found to contribute to the synthesis of functional selectin ligands.
Therapeutic targeting of molecules involved in leukocyte–endothelial cell interactions
Authors: Kaneider Nicole C. , Leger Andrew J. , Kuliopulos Athan
Published: September 2006

Inflammation is traditionally viewed as a physiological reaction to tissue injury. Leukocytes contribute to the inflammatory response by the secretion of cytotoxic and pro‐inflammatory compounds, by phagocytotic activity and by targeted attack of foreign antigens. Leukocyte accumulation in tissues is important for the initial response to injury. However, the overzealous accumulation of leukocytes in tissues also contributes to a wide variety of diseases, such as atherosclerosis, chronic inflammatory bowel disease, rheumatoid arthritis, multiple sclerosis, vasculitis, systemic inflammatory response syndrome, juvenile diabetes and psoriasis. Many therapeutic interventions target immune cells after they have already migrated to the site of inflammation. This review addresses different therapeutic strategies, used to reduce or prevent leukocyte–endothelial cell interactions and communication, in order to limit the progression of inflammatory diseases.
Mycobacterium tuberculosis possesses a functional enzyme for the synthesis of vitamin C, L‐gulono‐1,4‐lactone dehydrogenase
Authors: Wolucka Beata A. , Communi David
Published: September 2006

The last step of the biosynthesis of l‐ascorbic acid (vitamin C) in plants and animals is catalyzed by l‐gulono‐1,4‐lactone oxidoreductases, which use both l‐gulono‐1,4‐lactone and l‐galactono‐1,4‐lactone as substrates. l‐Gulono‐1,4‐lactone oxidase is missing in scurvy‐prone, vitamin C‐deficient animals, such as humans and guinea pigs, which are also highly susceptible to tuberculosis. A blast search using the rat l‐gulono‐1,4‐lactone oxidase sequence revealed the presence of closely related orthologs in a limited number of bacterial species, including several pathogens of human lungs, such as Mycobacterium tuberculosis, Pseudomonas aeruginosa, Burkholderia cepacia and Bacillus anthracis. The genome of M. tuberculosis, the etiologic agent of tuberculosis, encodes a protein (Rv1771) that shows 32% identity with the rat l‐gulono‐1,4‐lactone oxidase protein. The Rv1771 gene was cloned and expressed in Escherichia coli, and the corresponding protein was affinity‐purified and characterized. The FAD‐binding motif‐containing Rv1771 protein is a metalloenzyme that oxidizes l‐gulono‐1,4‐lactone (Km 5.5 mm) but not l‐galactono‐1,4‐lactone. The enzyme has a dehydrogenase activity and can use both cytochrome c (Km 4.7 µm) and phenazine methosulfate as exogenous electron acceptors. Molecular oxygen does not serve as a substrate for the Rv1771 protein. Dehydrogenase activity was measured in cellular extracts of a Mycobacterium bovis BCG strain. In conclusion, M. tuberculosis produces a novel, highly specific l‐gulono‐1,4‐lactone dehydrogenase (Rv1771) and has the capacity to synthesize vitamin C.
α‐Conotoxin analogs with additional positive charge show increased selectivity towards Torpedo californica and some neuronal subtypes of nicotinic acetylcholine receptors
Authors: Kasheverov Igor E. , Zhmak Maxim N. , Vulfius Catherine A. , Gorbacheva Elena V. , Mordvintsev Dmitry Y. , Utkin Yuri N. , van Elk René , Smit August B. , Tsetlin Victor I.
Published: September 2006

α‐Conotoxins from Conus snails are indispensable tools for distinguishing various subtypes of nicotinic acetylcholine receptors (nAChRs), and synthesis of α‐conotoxin analogs may yield novel antagonists of higher potency and selectivity. We incorporated additional positive charges into α‐conotoxins and analyzed their binding to nAChRs. Introduction of Arg or Lys residues instead of Ser12 in α‐conotoxins GI and SI, or D12K substitution in α‐conotoxin SIA increased the affinity for both the high‐ and low‐affinity sites in membrane‐bound Torpedo californica nAChR. The effect was most pronounced for [D12K]SIA with 30‐ and 200‐fold enhancement for the respective sites, resulting in the most potent α‐conotoxin blocker of the Torpedo nAChR among those tested. Similarly, D14K substitution in α‐conotoxin [A10L]PnIA, a blocker of neuronal α7 nAChR, was previously shown to increase the affinity for this receptor and endowed [A10L,D14K]PnIA with the capacity to distinguish between acetylcholine‐binding proteins from the mollusks Lymnaea stagnalis and Aplysia californica. We found that [A10L,D14K]PnIA also distinguishes two α7‐like anion‐selective nAChR subtypes present on identified neurons of L. stagnalis: [D14K] mutation affected only slightly the potency of [A10L]PnIA to block nAChRs on neurons with low sensitivity to α‐conotoxin ImI, but gave a 50‐fold enhancement of blocking activity in cells with high sensitivity to ImI. Therefore, the introduction of an additional positive charge in the C‐terminus of α‐conotoxins targeting some muscle or neuronal nAChRs made them more discriminative towards the respective nAChR subtypes. In the case of muscle‐type α‐conotoxin [D12K]SIA, the contribution of the Lys12 positive charge to enhanced affinity towards Torpedo nAChR was rationalized with the aid of computer modeling.
Binding of human centrin 2 to the centrosomal protein hSfi1
Authors: Martinez‐Sanz Juan , Yang Ao , Blouquit Yves , Duchambon Patricia , Assairi Liliane , Craescu Constantin T.
Published: September 2006

hSfi1, a human centrosomal protein with homologs in other eukaryotic organisms, includes 23 repeats, each of 23 amino acids, separated by 10 residue linkers. The main molecular partner in the centrosome is a small, calcium‐binding EF‐hand protein, the human centrin 2. Using isothermal titration calorimetry experiments, we characterized the centrin‐binding capacity of three isolated hSfi1 repeats, two exhibiting the general consensus motif and the third being the unique Pro‐containing human repeat. The two standard peptides bind human centrin 2 and its isolated C‐terminal domain with high affinity (∼ 107 m−1) by an enthalpy‐driven mechanism, with a moderate Ca2+ dependence. The Pro‐containing repeat shows a binding affinity that is two orders of magnitude lower. The target binding site is localized within the C‐terminal domain of human centrin 2. Fluorescence titration and NMR spectroscopy show that the well‐conserved Trp residue situated in the C‐terminus of each repeat is deeply embedded in a protein hydrophobic cavity, indicating that the peptide direction is reversed relative to previously studied centrin targets. The present results suggest that almost all of the repeats of the Sfi1 protein may independently bind centrin molecules. On the basis of this hypothesis and previous studies on centrin self‐assembly, we propose a working model for the role of centrin–Sfi1 interactions in the dynamic structure of centrosome‐associated contractile fibers.
Power transfer in non-linear gravitational clustering and asymptotic universality
Authors: Padmanabhan T. , Ray Suryadeep
Published: September 2006

We study the non-linear gravitational clustering of collisionless particles in an expanding background using an integro-differential equation for the gravitational potential. In particular, we address the question of how the non-linear mode–mode coupling transfers power from one scale to another in the Fourier space if the initial power spectrum is sharply peaked at a given scale. We show that the dynamical equation allows self-similar evolution for the gravitational potential φk(t) in Fourier space of the form φk(t) = F(t)D(k) where the function F(t) satisfies a second-order non-linear differential equation. We analyse the relevant solutions of this equation, thereby determining the asymptotic time evolution of the gravitational potential and density contrast. The analysis suggests that both F(t) and D(k) have well-defined asymptotic forms indicating that the power transfer leads to a universal power spectrum at late times. The analytic results are compared with numerical simulations, showing good agreement over the range at which we could test them.
Spectropolarimetry of PKS 0040-005 and the orientation of broad
absorption line quasar
Authors: Brotherton M. S. , De Breuck C. , Schaefer J. J.
Published: September 2006

We have used the Very Large Telescope (VLT) to obtain spectropolarimetry of the radio-loud, double-lobed broad absorption line (BAL) quasar PKS 0040−005. We find that the optical continuum of PKS 0040−005 is intrinsically polarized at 0.7 per cent with an electric vector position angle nearly parallel to that of the large-scale radio axis. This result is naturally explained in terms of an equatorial scattering region seen at a small inclination, building a strong case that the BAL outflow is not equatorial. In conjunction with other recent results concerning BAL quasars, the era of simply characterizing these sources as ‘edge-on’ is over.
Detached shells as tracers of asymptotic giant branch–interstellar medium bow shocks
Authors: Wareing C. J. , Zijlstra Albert A. , Speck Angela K. , O'Brien T. J. , Ueta Toshiya , Elitzur M. , Gehrz R. D. , Herwig F. , Izumiura H. , Matsuura M. , Meixner M. , Stencel R. E. , Szczerba R.
Published: September 2006

New Spitzer imaging observations have revealed the structure around the Mira variable star R Hya to be a one-sided parabolic arc 100 arcsec to the west, stretching from north to south. We successfully model R Hya and its surroundings in terms of an interaction of the stellar wind from an asymptotic giant branch (AGB) star with the interstellar medium (ISM) the star moves through. Our three-dimensional hydrodynamic simulation reproduces the structure as a bow shock into the oncoming ISM. We propose this as another explanation of detached shells around such stars, which should be considered alongside current theories of internal origin. The simulation predicts the existence of a tail of ram-pressure-stripped AGB material stretching downstream. Indications for such a tail behind R Hya are seen in IRAS maps.
The central elliptical galaxy in fossil groups and formation of brightest cluster galaxies
Authors: Khosroshahi Habib G. , Ponman Trevor J. , Jones Laurence R.
Published: September 2006

We study the dominant central giant elliptical galaxies in ‘fossil groups’ using deep optical (R-band) and near-infrared (Ks-band) photometry. These galaxies are as luminous as the brightest cluster galaxies (BCGs), raising immediate interest in their link to the formation of BCGs and galaxy clusters. However, despite apparent similarities, the dominant fossil galaxies show non-boxy isophotes, in contrast to the most luminous BCGs. This study suggests that the structure of the brightest group galaxies produced in fossil groups are systematically different to the majority of BCGs. If the fossils do indeed form from the merger of major galaxies including late-types within a group, then their discy nature is consistent with the results of recent numerical simulations of semi-analytical models which suggest that gas rich mergers result in discy isophote ellipticals.

We show that fossils form a homogeneous population in which the velocity dispersion of the fossil group is tightly correlated with the luminosity of the dominant elliptical galaxy. This supports the scenario in which the giant elliptical galaxies in fossils can grow to the size and luminosity of BCGs in a group environment. However, the boxy structure of luminous BCGs indicate that they are either not formed as fossils, or have undergone later gas-free mergers within the cluster environment.
Pregnenolone sulphate and Zn2+ inhibit recombinant rat GABAA receptor through different channel property
Authors: Wang M.‐D. , Rahman M. , Zhu D. , Bäckström T.
Published: September 2006

Aims:  We compared the antagonistic effects of state‐dependent gamma‐aminobutyric acid A (GABAA) receptor blockers picrotoxin, Zn2+ and pregnenolone sulphate (PS) on GABA‐ and pentobarbital‐activated currents in recombinant rat GABAA receptors in Xenopus oocytes.

Methods:  Experiments were performed with wild type ratα1β2γ2L and α1β2 receptors, mutants α1V256Sβ2γ2L and α1β2A252Sγ2L receptors by the two‐electrode voltage‐clamp technique.

Results:  In contrast to respective 3840‐ and 56‐fold increases in Zn2+ potencies to inhibit GABA‐ and pentobarbital‐activated currents in the α1β2 receptor, the corresponding potencies of PS remained unchanged in comparison with the α1β2γ2L receptor. A homologous mutation of the residue at 2′ position closest to the cytoplasmic end of the M2 helix to serine on both α1 and β2 subunit, α1V256S and β2A252S, abolished the inhibition of GABAA receptor by PS. In comparison with the wild type α1β2γ2L receptor, mutants α1V256Sβ2γ2L and α1β2A252Sγ2L receptors did not affect the Zn2+ inhibition. Furthermore, a significant increase in GABA potency was observed in the mutant α1V256Sβ2γ2L receptor (P < 0.05), but not the mutant α1β2A252Sγ2L receptor compared with the wild type receptor.

Conclusions:  Pregnenolone sulphate was a γ2‐subunit independent inhibitor in the GABAA receptor, whereas the Zn2+ antagonism was profoundly influenced by the γ2‐subunit. It is likely that the 2′ residue closest to the N‐terminus of the protein at M2 helix on both α1 and β2 subunit are critical to the inhibitory actions of PS and the function of Cl− channels. These results are consistent with the hypothesis that PS behaves as a Cl− channel blocker that does not share with Zn2+, the coincident channel property in the GABAA receptors.
The
Pseudomonas aeruginosa
Universal Stress Protein PA4352 Is Essential for Surviving Anaerobic Energy Stress
Authors: Boes Nelli , Schreiber Kerstin , Härtig Elisabeth , Jaensch Lothar , Schobert Max
Published: September 2006

During infection of the cystic fibrosis (CF) lung,
Pseudomonas aeruginosa
microcolonies are embedded in the anaerobic CF mucus. This anaerobic environment seems to contribute to the formation of more robust
P. aeruginosa
biofilms and to an increased antibiotic tolerance and therefore promotes persistent infection. This study characterizes the
P. aeruginosa
protein PA4352, which is important for survival under anaerobic energy stress conditions. PA4352 belongs to the universal stress protein (Usp) superfamily and harbors two Usp domains in tandem. In
Escherichia coli
, Usp-type stress proteins are involved in survival during aerobic growth arrest and under various other stresses. A
P. aeruginosa
PA4352 knockout mutant was tested for survival under several stress conditions. We found a decrease in viability of this mutant compared to the
P. aeruginosa
wild type during anaerobic energy starvation caused by the missing electron acceptors oxygen and nitrate. Consistent with this phenotype under anaerobic conditions, the PA4352 knockout mutant was also highly sensitive to carbonyl cyanide
m
-chlorophenylhydrazone, the chemical uncoupler of the electron transport chain. Primer extension experiments identified two promoters upstream of the PA4352 gene. One promoter is activated in response to oxygen limitation by the oxygen-sensing regulatory protein Anr. The center of a putative Anr binding site was identified 41.5 bp upstream of the transcriptional start site. The second promoter is active only in the stationary phase, however, independently of RpoS, RelA, or quorum sensing. This is the second
P. aeruginosa
Usp-type stress protein that we have identified as important for survival under anaerobic conditions, which resembles the environment during persistent infection.
Granular Layer in the Periplasmic Space of Gram-Positive Bacteria and Fine Structures ofEnterococcus gallinarumandStreptococcus gordoniiSepta Revealed by Cryo-Electron Microscopy of Vitreous Sections
Authors: Zuber Benoît , Haenni Marisa , Ribeiro Tânia , Minnig Kathrin , Lopes Fátima , Moreillon Philippe , Dubochet Jacques
Published: September 2006

High-resolution structural information on optimally preserved bacterial cells can be obtained with cryo-electron microscopy of vitreous sections. With the help of this technique, the existence of a periplasmic space between the plasma membrane and the thick peptidoglycan layer of the gram-positive bacteriaBacillus subtilisandStaphylococcus aureuswas recently shown. This raises questions about the mode of polymerization of peptidoglycan. In the present study, we report the structure of the cell envelope of three gram-positive bacteria (B. subtilis,Streptococcus gordonii, andEnterococcus gallinarum). In the three cases, a previously undescribed granular layer adjacent to the plasma membrane is found in the periplasmic space. In order to better understand how nascent peptidoglycan is incorporated into the mature peptidoglycan, we investigated cellular regions known to represent the sites of cell wall production. Each of these sites possesses a specific structure. We propose a hypothetic model of peptidoglycan polymerization that accommodates these differences: peptidoglycan precursors could be exported from the cytoplasm to the periplasmic space, where they could diffuse until they would interact with the interface between the granular layer and the thick peptidoglycan layer. They could then polymerize with mature peptidoglycan. We report cytoplasmic structures at theE. gallinarumseptum that could be interpreted as cytoskeletal elements driving cell division (FtsZ ring). Although immunoelectron microscopy and fluorescence microscopy studies have demonstrated the septal and cytoplasmic localization of FtsZ, direct visualization of in situ FtsZ filaments has not been obtained in any electron microscopy study of fixed and dehydrated bacteria.