bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Functional Polymorphism in the IL - 10 Promoter Influences the Response After Vaccination With HBsAg and Hepatitis A *
Authors: Höhler Thomas , Reuss Esther , Freitag Christine M. , Schneider Peter M. 
Published: May 2005

Abstract

The immune response to hepatitis B surface antigen (HBsAg) is mostly genetically determined. Interleukin 10 (IL-10) is a central immunoregulatory cytokine with important effects on B-cells. We have studied the influence of

IL
-
10

promoter polymorphisms on the immune response to HBsAg and hepatitis A vaccination. We vaccinated 202 twin pairs in an open prospective study with a combined recombinant HBsAg/inactivated hepatitis A vaccine.

IL
-
10

promoter polymorphisms were investigated in all individuals and their influence on anti-HBs, and anti-HAV responsiveness was studied. In the multiple regression analysis accounting for smoking, gender, body mass index and age, the

ACC

haplotype (−

1082

, −

819

and −

592

) had a strong influence on anti-HBs production. Individuals carrying the

ACC

haplotype had anti-HBs titres almost twice as high as individuals without this haplotype. In contrast, anti-HAV production was suppressed by the presence of the −1082A allele in comparison with individuals homozygous for the −1082G allele. The contribution of the shared

IL
-
10

promoter haplotype accounted for 27% of the genetic influence on anti-HBs antibody response.
In conclusion
, genetic variability in the

IL
-
10

promoter is an important modulator of the immune response against hepatitis viral antigens. (Hepatology 2005.)
Hepatic Targeting of Transplanted Liver Sinusoidal Endothelial Cells in Intact Mice *
Authors: Benten Daniel , Follenzi Antonia , Bhargava Kuldeep K. , Kumaran Vinay , Palestro Christopher J. , Gupta Sanjeev 
Published: May 2005

Abstract

Targeting of cells to specific tissues is critical for cell therapy. To study endothelial cell targeting, we isolated mouse liver sinusoidal endothelial cells (LSEC) and examined cell biodistributions in animals. To identify transplanted LSEC in tissues, we labeled cells metabolically with DiI-conjugated acetylated low density lipoprotein particles (DiI-Ac-LDL) or 111Indium-oxine, used LSEC from Rosa26 donors expressing β-galactosidase or Tie-2-GFP donors with green fluorescent protein (GFP) expression, and tranduced LSEC with a GFP-lentiviral vector. LSEC efficiently incorporated 111Indium and DiI-Ac-LDL and expressed GFP introduced by the lentiviral vector. Use of radiolabeled LSEC showed differences in cell biodistributions in relation to the cell transplantation route. After intraportal injection, LSEC were largely in the liver (60 ± 13%) and, after systemic intravenous injection, in lungs (67 ± 9%); however, after intrasplenic injection, only some LSEC remained in the spleen (29 ± 10%;

P

< .01), whereas most LSEC migrated to the liver or lungs. Transplanted LSEC were found in the liver, lungs, and spleen shortly after transplantation, whereas longer-term cell survival was observed only in the liver. Transplanted LSEC were distinct from Kupffer cells with expression of Tie-2 promoter-driven GFP and of CD31, without F4/80 reactivity. In further studies using radiolabeled LSEC, we established that the manipulation of receptor-mediated cell adhesion in liver sinusoids or the manipulation of blood flow–dependent cell exit from sinusoids improved intrahepatic retention of LSEC to 89 ± 7% and 89 ± 5%, respectively (

P

< .01).
In conclusion
, the targeting of LSEC to the liver and other organs is directed by vascular bed–specific mechanisms, including blood flow–related processes, and cell-specific factors. These findings may facilitate analysis of LSEC for cell and gene therapy applications. (Hepatology 2005.)
RF plasma treatment of metallic implant surfaces
Authors: Kummer Frederick J. , Ricci John L. , Blumenthal Norman C. 
Published: May 2005

AbstractRadio‐frequency air plasma treatments of Ti‐6‐4 and Co‐Cr implants increased surface wettability but concurrently increased ionic release. In vitro tissue culture experiments demonstrated no enhancement of cell growth and enrichment. Short‐term rabbit tibial implants also showed no difference between treated and untreated implants.
Increase of stability in external fracture fixation by hydroxyapatite‐coated bone screws
Authors: Augat Peter , Claes Lutz , Hanselmann Karl‐Friedrich , Suger Gebhard , Fleischmann Wim 
Published: May 2005

AbstractA major problem in fracture treatment by external fixation is screw loosening, which often results in reduced stability and can lead to prolonged treatment. A load‐carrying experiment was conducted to determine whether coating implants with bioactive hyroxyapatite (HA) increases screw stability. Twelve HA‐coated ASIF screws with 3 different macroporosities were inserted in 12 sheep that had already been fitted with a 6‐pin external fixator for the treatment of a tibial osteotomy. The same number of uncoated polished steel screws served as controls. Although initial stability was not different for HA‐coated screws, average removal torque after a 9‐week implantation period increased with increasing macroporosity of the HA coating (p <.002). Instability of some screws was accompanied by histologic findings of cartilagenous tissue and proliferation of periosteal callus. Near the threads in the tibial cortex and in the shaft area of the screw were seen large numbers of HA particles that had been sheared off during implantation as well as during screw removal because of high contract forces between the HA coating and bone. Particulate debris of HA particles as well as the release of small bone fragments during explantation is likely to be unavoidable since HA adherence to bone is greater than adherence to steel after several weeks of implantation. © 1995 John Wiley & Sons, Inc.
Osseous attachment to vitreous carbons
Authors: Stanitski Carl L. , Mooney Vert 
Published: May 2005

AbstractSkeletal ingrowth to vitreous carbon was tested by means of bicortical corrugated vitreous carbon dowels of various groove sizes in dog femora and humeri. After a 4‐week ingrowth period, resistance of the implants to push out loads ranged from 66 to 100 kg. Comparable data was obtained from similar sized polymethylmethacrylate and vitreous carbon‐coated graphite implants. Histologic acceptability of the vitreous carbon appeared excellent in terms of minimal foreign body giant cell and fibrous tissue responses. Axial loading tests with femoral bone bridges demonstrated the vitreous carbon to be too brittle to withstand these functional loads. Experience with a canine skeletally fixed transcutaneous limb prosthetic device is presented.
Degradative analysis of glass ionomer polyelectrolyte cements
Authors: Cook Wayne D. 
Published: May 2005

AbstractAs part of a detailed investigation of the setting mechanisms of dental polyelectrolyte cements, the Al3+, Ca2+, and Na+ concentrations in the matrix phase of glass ionomer cements were measured as a function of the cements age by use of a selective degradation technique. In the early stages of cement formation, all three cations were rapidly released from the glass, and it is in‐ferred that both Ca2+ and Al3+ are responsible for gelation. Even after 5 × 104 min, the reaction was incomplete and still continuing.
Reduction of fibrinogen adsorption on PEG‐coated polystyrene surfaces
Authors: Bergström Karin , Holmberg Krister , Safranj Agneza , Hoffman Allan S. , Edgell Michael J. , Kozlowski Antoni , Hovanes Bruce A. , Harris J. Milton 
Published: May 2005

AbstractReduction of protein adsorption by coating surfaces with polyethylene glycol (PEG) is well documented. The present work has four goals related to these previous studies: first, to develop chemistry providing densely packed, covalently bound PEG on polystyrene (PS); second, to determine the ability of these modified surfaces to reject fibrinogen; third, to compare the protein‐rejecting ability of branched and linear PEGs; and fourth, to examine the utility of an ELISA‐type procedure for measuring protein adsorption. It was found that PEG‐epoxide could be readily coupled to amine groups of poly(ethy1ene imine) (PEI), which had been preadsorbed onto an oxidized PS surface. The PEG groups on branched PEGs appear to act as an excluded volume to repel proteins, similar to arguments previously raised for linear PEGs. The results of protein adsorption studies showed that fibrinogen adsorption is significantly reduced by coating polystyrene with either linear or branched PEGs of 1500 to 20,000 in molecular weight. The ELISA technique was found to be equivalent in sensitivity to radiolabeled fibrinogen for estimating adsorption levels. It is expected that PEG‐coated PS will have much utility in a variety of biomedical applications.
The fracture toughness of titanium‐fiber‐reinforced bone cement
Authors: Topoleski L. D. Timmie , Ducheyne Paul , Cuckler John M. 
Published: May 2005

AbstractFracture of the poly(methyl methacrylate) bone cement mantle can lead to the loosening and ultimate failure of cemented total joint prostheses. The addition of fibers to the bone cement increases fracture resistance and may reduce, if not eliminate, in vivo fracturing. This study discusses the effect of incorporating titanium (Ti) fibers on fracture toughness. Essential characteristics of the composite bone cement included a homogeneous and uniform fiber distribution, and a minimal increase in apparent viscosity of the polymerizing cement. Ti fiber contents of 1%, 2%, and 5% by volume increased the fracture toughness over non‐reinforced bone cement by up to 56%. Bone cements of two different viscosities were used as matrix material, but when reinforced with the same fiber type and content, they showed no difference in fracture toughness. Four different fiber aspect ratios (68, 125, 227, 417) were tested. At 5% fiber content, there was no statistically significant dependence of fracture toughness on fiber aspect ratio. Scanning electron microscopy revealed important toughening mechanisms such as fiber/matrix debonding, local fracture path alteration, and ductile fiber deformation and fracture. Fiber fracture was evidence that the critical fiber length was exceeded. The surfaces of the Ti fibers were rough and irregular, indicating that a high degree of mechanical interlock between matrix and fiber was likely. The energy absorption contribution of plastic deformation and ductile fracture is absent in brittle fibers, like carbon, but is a distinction of the Ti fibers used in this study. © 1992 John Wiley & Sons, Inc.
The effects of bone cement powder on human adherent monocytes/macrophages in vitro
Authors: Davis R. G. , Goodman S. B. , Smith R. L. , Lerman J. A. , Williams R. J. 
Published: May 2005

AbstractThis study reports the effects of Simplex bone cement powder (BC) on the proliferation and production of bone resorbing factors in vitro by human adherent monocytes/macrophages. Adherent peripheral blood cells were isolated from seven healthy individuals and exposed to a dispersion of BC powder (1 mg/mL), phytohemagglutinin (PHA, 40 μg/mL), or medium alone at different periods of cell incubation (days 0–2, 0–7, 5–7, or 10–12). Cell proliferation was quantified by incorporation of 3H‐thymidine uptake. Culture supernatants were evaluated for levels of interleukin 1‐like activity (IL‐1) by murine thymocyte proliferation assay, prostaglandin E2 (PGE2) by radioimmunoassay, lysosomal enzyme activity (N‐acetyl‐β‐D‐glucosaminidase and β‐glucuronidase) using fluorometry, and collagen and casein degrading activity using radioactive substrates. Human adherent peripheral blood cells showed a proliferative response to PHA that coincided with cell maturation; BC did not inhibit PHA‐induced cell proliferation of either adherent or nonadherent blood cells, indicating the non‐toxic nature of these particles at the concentrations tested. BC stimulated increased release of the lysosomal enzyme N‐acetyl‐β‐D‐glucosaminidase; the levels of PGE2, IL‐1, collagenase, and caseinase were unchanged. © 1993 John Wiley & Sons, Inc.
Lens‐on‐surface method for investigating adhesion of Staphylococcus aureus to solid surfaces incubated in blood plasma
Authors: Elwing Hans , Askendal Agneta 
Published: May 2005

AbstractAdhesion of Staphylococcus aureus was investigated on flat silicon oxide surfaces that had been incubated in human plasma at different concentrations. Adhesion of bacteria did not occur at high incubation concentrations of plasma or when the surface had been incubated in egg albumin. However, significant adhesion was observed when plasma was diluted. With the use of an antibody method, it was noted that the adhesion of the bacteria coincided with adsorbed fibrinogen, and possibly also with IgG. We also investigated the effect of “narrow space” on the adsorption of blood plasma and subsequent adhesion of S. aureus. In these experiments, blood plasma was incubated under a convex lens placed upside‐down on the silicon oxide surface. This method creates a continuous gradient of space from the contact point of the lens and outward. After rinsing off the plasma and the lens, the surface was incubated with a suspension of S. aureus followed by quantification of the attached bacteria by means of optical methods. Adhesion of bacteria occurred in several circular zones that were easily detectable with the naked eye or by the means of simple optical methods. In addition, in these experiments, adhesion coincided with adsorbed fibrinogen or IgG at the surfaces. The increased bacterial adhesion to surfaces incubated in diluted plasma, or plasma incubated in narrow space, is a variant of the so‐called “Vroman effect.” With a model protein system consisting of fibrinogen and IgG and the corresponding antibodies, we demonstrate that “dilution” and “incubation in narrow space” are two phenomenologically similar methods. This methodologic investigation demonstrated that the lens‐on‐surface method is superior for the investigation of these aspects of bacterial adhesion. © 1994 John Wiley & Sons, Inc.
Osseous regeneration in the rat calvarium using novel delivery systems for recombinant human bone morphogenetic protein‐2 (rhBMP‐)
Authors: Kenley R. , Marden L. , Turek T. , Jin L. , Ron E. , Hollinger J. O. 
Published: May 2005

AbstractIn the current investigation, we report osseous regeneration in critical‐size rat calvarial defects using recombinant human bone morphogenetic protein‐2(rhBMP‐) and novel delivery systems based on biomaterials. The novel systems combine rhBMP‐ with dry powder microparticles of poly(D, L‐lactide‐co‐glycolide) (PLGA). The mixture of rhBMP‐ with PLGA microparticles is added to an aqueous solution of biopolymer to yield a semisolid paste. The biopolymers tested include autologous blood clot, hydroxypropyl methylcellulose, and sodium alginate cross‐linked with calcium ion. Insoluble collageneous bone matrix was also studied as a control. Test articles were made at 0‐, 10‐, and 30‐µg doses of rhBMP‐ and implanted in 8‐mm‐diameter rat calvarial defects (which will not heal if left untreated). The animals were examined 21 days after implantation by radiography, radiomorphometry, histology, and histomorphometry. All tested materials containing rhBMP‐ restored radiopacity and normal contouring to the calvarial defects. Samples without added rhBMP‐ yielded only soft tissue within the defects. Histology showed restoration of inner and outer bone tables plus marrow constituents. The PLGA microparticles were significantly resorbed at the 21‐day time point. Although small differences between delivery systems were evident at 0‐ and 10‐µg rhBMP‐ doses, all test articles performed essentially equivalently at the 30‐µg dose. Thus, novel delivery systems for rhBMP‐ offer the promise of combining the intrinsic bioactivity of the osteoinductive protein with pharmaceutically acceptable biomaterials. © 1994 John Wiley & Sons, Inc.
Osteoblast function on synthetic biodegradable polymers
Authors: Ishaug Susan L. , Yaszemski Michael J. , Bizios Rena , Mikos Antonios G. 
Published: May 2005

AbstractRat osteoblasts were cultured on films of biodegradable poly(L‐lactic acid) (PLLA), 75:25 poly(DL‐lactic‐co‐glycolic acid) (PLGA), 50:50 PLGA, and poly(glycolic acid) (PGA) for up to 14 days. Osteoblasts attached equally well to all the polymer substrates after 8 h in culture. By day 4 in culture, osteoblasts had exceeded confluency numbers, and their proliferation leveled off by day 7. An increase in alkaline phosphatase (ALP) activity from 1.92 (±0.47) × 10−7 for day 7 to 5.75 (±0.12) × 10−7 μmol/cell per min for day 14 was reported for osteoblasts cultured on 75:25 PLGA, which was comparable to that observed for tissue culture polystyrene (TCPS) controls. The ALP activities expressed by osteoblasts cultured on PLLA, 50:50 PLGA, and PGA films did not significantly increase over time. Collagen synthesis for osteoblasts cultured on all polymer substrates was similar to that of TCPS and did not vary with time. The morphology of cultured osteoblasts was not affected by the continuous degradation of the polymer substrates. These results demonstrate that poly(α‐hydroxy esters) can provide a suitable substrate for osteoblast culture and hold promise in bone regeneration by osteoblast transplantation. © 1994 John Wiley & Sons, Inc.
Isolation of predominantly submicron‐sized UHMWPE wear particles from periprosthetic tissues
Authors: Campbell P. , Ma S. , Yeom B. , McKellop H. , Schmalzried T. P. , Amstutz H. C. 
Published: May 2005

AbstractA method of tissue digestion using sodium hydroxide was applied to the isolation and recovery of ultra‐high‐molecular‐weight polyethylene (UHMWPE) particles from tissues around failed total hip replacements. Density gradient ultracentrifugation of the digested tissues was performed to separate the UHMWPE from cell debris and other particulates. Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC) verified that the recovered particles were UHMWPE. When viewed by scaning electron microscopy, individual particles were clearly observed and were either rounded or elongated. The majority were submicron in size. The application of this method to the study or particles from periprosthetic tissues may elucidate aspects of biomaterial particles size and shape that are important to the biologic response to, and clinical outcome of, total joint replacement. © 1995 John wiley & Sons, Inc.
Influence of implant location on the mechanical characteristics using the transcortical model
Authors: Dalton Jeanette E. , Cook Stephen D. 
Published: May 2005

AbstractMechanical evaluation of implants harvested following surgical implantation is often performed as part of the screening process for new materials or surface textures. The question of randomization with respect to implant placement often arises when attempting to design a study to evaluate several implant types, while minimizing the number of animals required to perform the investigation. The purpose of this study was to analyze the effects of implant placement within the canine femur on mechanical characteristics of the bone–implant interface when using the transcortical model. Both smooth and porous‐surfaced implants were evaluated at several time periods to determine the effects of placement in the medial versus left cortex, proximal versus distal placement, and left versus right femur. The smooth‐surfaced implants demonstrated no significant effects due to placement within the femur. The results demonstrate the necessity for careful study design when evaluating smooth surfaced implants; however, paired comparisons in either the medial versus lateral cortex or left versus right femur will provide unbiased comparisons between the implants. © 1995 John Wiley & Sons, Inc.
Interface mechanics and histomorphometric analysis of hydroxyapatite‐coated and porous glass‐ceramic implants in canine bone
Authors: Nimb Lars , Jensen Jørgen Steen , Gotfredsen Klaus 
Published: May 2005

AbstractA canine study was performed to make a histological and biomechanical evaluation of the interface between bone and two different bioceramic implants. A newly developed glass‐ceramic formed by P2O5, CaO, SiO2, and Al2O3, giving a crystal phase composed of CaP2O6AlPO4SiP2O7, was compared to hydroxyapatite (HA) coated Ti6Al4V implants. A total of 24 implants were inserted into the femoral condyle of 15 adult female golden retriever dogs weighing 20–25 kg. There was a 12 week follow‐up. Implants were examined by mechanical testing, histology, histomorphometry, microradiograpic methods, and EDAX analysis. The ultimate shear strength for the HA‐coated implants was significantly higher than in the glass‐ceramic group. When these values were related to the histomorphometric measurements, the difference could be explained by the tissue‐to‐implant contact. The glass‐ceramic showed direct contact only with nonmineralized, osteoid bone. The HA‐coated implants, however, were integrated into the bone. The study indicated that porous glass‐ceramic containing AlPO4 causes local osteomalacia and might not be suitable for clinical purposes. © 1995 John Wiley & Sons, Inc.
Introduction: Protein phosphorylation and signal transduction in bacteria
Authors: Saier Milton H. 
Published: May 2005

AbstractA single type of reversible protein‐phosphorylating system, the ATP‐dependent protein kinase/phosphatase system, is employed in signal transduction in eukaryotes. By contrast, recent work has revealed that three types of protein‐phosphorylating systems mediate signal transduction in bacteria. These systems are (1) classical protein kinase/phosphatase systems, (2) sensor‐kinase/response‐regulator systems, and (3) the multifaceted phosphoenolpyruvate‐dependent phosphotransferase system. Physiological, structural, and mechanistic aspects of these three evolutionarily distinct systems are discussed in the papers of this written symposium. © 1993 Wiley‐Liss, Inc.
Regulatory interactions involving the proteins of the phosphotransferase system in enteric bacteria
Authors: Saier Milton H. 
Published: May 2005

AbstractSugar uptake and cytoplasmic inducer generation as well as cyclic AMP synthesis are regulated by the phosphoenolpyruvate:sugar phosphotransferase system (PTS) in Gram‐negative enteric bacteria. In these organisms, the free form of the glucose‐specific Enzyme IIA (IIAglc) of the PTS, which can be phosphorylated on a histidyl residue by PEP and the PTS energy coupling proteins, inhibits the activities of non‐PTS carbohydrate permeases and catabolic enzymes. By contrast, the phosphorylated form of IIAglc appears to activate adenylate cyclase, the cyclic AMP biosynthetic enzyme. What is known of the molecular details of these regulatory interactions will be summarized, and a novel regulatory mechanism involving the fructose repressor, FruR, which controls the transcription of genes encoding enzymes which catalyze reactions in central pathways of carbon metabolism, will be presented. © 1993 Wiley‐Liss, Inc.