bluuebunny/crossref_metadata_2025_split huggingface dataset:
METHYLATION OF E. COLI TRANSFER RIBONUCLEIC ACIDS BY A tRNA ADENINE‐l‐METHYLTRANSFERASE FROM RAT BRAIN CORTEX AND BULK‐ISOLATED NEURONS
Authors: Salas Carlos E. , Sellinger Otto Z. 
Published: December 2006

Abstract— Brain cortices or bulk‐isolated neuronal cell bodies prepared from cortices of 8‐day old male rats were used as the source of a l‐methyl adenine‐specific tRNA methyltransferase (tRNA‐AMT). Ammonium sulfate fractionation and chromatography on spheroidal hydroxylapatite and Sephadex G‐200 yielded an 80‐fold purified enzyme, as determined by using E. coli bulk tRNA as substrate. The kinetic parameters of tRNA‐AMT for the substrate S‐adenosyl‐l‐methionine (SAM) (Km= 6 μM) and the inhibitor, S‐adenosyl‐l‐homocysteine (SAH) (Ki= 3.4 μm) were determined and several SAH analogs tested as inhibitors. S‐Adenosyl‐l‐cysteine (SAC) (10‐4m) and S‐adenosyl‐d‐homocysteine (SADH) (10‐4m) produced a 35 and a 21% reduction in enzyme activity, respectively. The effects of Mg2+, NH4+ acetate and of the polyamines spermine, putrescine and spermidine on the brain tRNA‐AMT mimicked the effects of these agents on hepatic tRNA‐AMT (Glicket al, 1975).Comparing the ability of cerebral tRNA‐AMT to methylate E. coli tRNAglu2, tRNAval, tRNAphe and bulk tRNA revealed tRNAglu2 as the best and tRNAphe as the least effective substrate.tRNA‐AMT prepared from neuronal cell bodies showed closely similar characteristics to the cortical enzyme. A comparison of the activities of tRNA‐AMT in neurons and glial cells revealed higher values in the former.
STUDIES ON THE LOW‐MOLECULAR WEIGHT GLYCOPROTEIN GP‐350: MOLECULAR AND IMMUNOLOGICAL HETEROGENEITY
Authors: Simonian S. , Heijlman J. , Hooghwinkel G. J. M. 
Published: December 2006

Abstract— GP‐350 was isolated from the water soluble cell fraction of bovine brain and liver. The isolated protein preparations were electrophoresed in the presence of SDS in 19% polyacrylamide gels and in the absence or presence of Triton X‐100 and urea in 7.5% polyacrylamide gels. These experiments show that the GP‐350 protein fraction from the different tissues behaves as a class of low‐molecular weight proteins with different intrinsic charges. The majority of the protein bands which were resolved in the presence or absence of Triton X‐100 and urea in 7.5% polyacrylamide gels were not reactive with the antiserum directed against the total GP‐350 protein fraction.Moreover, on gel chromatography in Sephadex G‐50, GP‐350 was fractionated into several peaks. The reactivity with the GP‐350 antiserum in double immunodiffusion was present primarily in the major peak with a molecular weight between 9500 and 11,500; this peak gave three precipitin lines. Furthermore, lipid analysis of GP‐350 has shown that GP‐350 protein preparations from brain contained about 17% (w/w) choloroform‐methanol (2:Insoluble lipids. The lipids were for the major part of neutral type and only trace amounts of glycolipids were detectable. The lipid‐free GP‐350 protein was immunologically identical to the total GP‐350 fraction.On the basis of this heterogeneity in charge, molecular composition and immunological properties we conclude that GP‐350 is a mixture of low‐molecular weight protein and lipid constituents.
EFFECTS OF TETRODOTOXIN, CALCIUM AND MAGNESIUM ON THE RELEASE OF AMINO ACIDS FROM SLICES OF GUINEA‐PIG CEREBRAL CORTEX
Authors: Potashner S. J. 
Published: December 2006

Abstract— Tetrodotoxin, Ca2+‐deprivation and high‐Mg2+ were used in an effort to identify the portion of the evoked release of endogenous amino acids, labelled via metabolism of [14C]‐glucose, and several exogenous labelled amino acids, that came from nerve terminals when slices of guinea pig cerebral cortex were superfused with glucose‐free solutions and stimulated electrically.With some exceptions, spontaneous release of labelled amino acids was decreased by 2 μm‐tetrodotoxin but increased in Ca2+‐free medium and in solutions containing an extra 24 mm‐MgCl2. Tetrodotoxin suppressed 85–90% of the stimulated release of almost all labelled amino acids, but had a smaller effect on the release of endogenous 14C‐labelled threonine‐serine‐glutamine (unseparated). In Ca2+‐free solution, the stimulated release of endogenous 14C‐labelled glutamate, aspartate and GABA was suppressed by 80–90%, but that of endogenous 14C‐labelled threonine‐serine‐glutamine was unaffected as was most of the release of the other labelled amino acids. In medium containing an extra 24mM‐MgCl2, the stimulated release of endogenous 14C‐labelled glutamate, aspartate and GABA was suppressed by 75‐85%, that of exogenous labelled aspartate and GABA by 50–65%, but the release of the other labelled amino acids was unaffected. The control stimulated releases of endogenous 14C‐labelled glutamate, aspartate and GABA were much larger than those of other labelled amino acids but were reduced by tetrodotoxin, Ca2+‐deprivation and high‐Mg2+ to a level similar to that of the control stimulated releases of the other labelled amino acids.These results suggest that almost all of the stimulated release of endogenous 14C‐labelled glutamate, aspartate and GABA came from nerve terminals while those of the other labelled amino acids came from other tissue elements. In addition, they are in accord with a transmitter role for glutamate, aspartate and GABA in cerebral cortex.
Exogenous purines induce differential responses in the proximal and distal regions of the possum sphincter of Oddi
Authors: Woods C. M. , Toouli J. , Saccone G. T. P. 
Published: December 2006

Summary1The aim of this study was to compare the effect of exogenous ATP and adenosine on spontaneous motility of the proximal and distal regions of the possum sphincter of Oddi (SO).2ATP or adenosine (1 μm–1 mm) was applied to distal‐SO or proximal‐SO muscle rings in organ baths in the absence or presence of tetrodotoxin (TTX) or P1/P2 antagonists.3Both ATP and adenosine altered spontaneous activity, predominantly in proximal‐SO rings.4Exogenous ATP induced a bi‐phasic response consisting of a brief TTX‐sensitive excitatory component, and a longer‐lasting TTX‐insensitive inhibitory component.5The excitatory ATP response likely involves P2X receptors, whereas the late inhibitory response likely involves P2Y receptors.6Exogenous adenosine decreased spontaneous SO activity, via a TTX‐insensitive mechanism.7Exogenous purines modulate SO motility, acting primarily in the proximal region of the SO, via neural and non‐neural mechanisms and multiple purine receptor subtypes.
Five‐year results of a prospective, randomized, controlled study evaluating treatment of intra‐bony defects with a natural bone mineral and GTR
Authors: Sculean Anton , Schwarz Frank , Chiantella Giovanni C. , Donos Nikolaos , Arweiler Nicole B. , Brecx Michel , Becker Jürgen 
Published: December 2006

AbstractBackground: Treatment with a natural bone mineral (NBM) and a guided tissue regeneration (GTR) has been shown to promote periodontal regeneration. However, until now there are only very limited data on the long‐term clinical results following this regenerative technique.Aim: To present the 5‐year results of a prospective, randomized, controlled clinical study evaluating the treatment of deep intra‐bony defects either with open flap debridement (OFD) and a combination of an NBM and GTR (test) or OFD alone (control).Methods: Nineteen patients diagnosed with advanced chronic periodontitis, and each of whom displayed one intra‐bony defect, received randomly the test or the control treatment. Results were evaluated at baseline, at 1 and at 5 years following therapy.Results: No statistically significant differences in any of the investigated parameters were observed at baseline between the two groups. At 1 year after therapy, the test group showed a reduction in mean probing depth (PD) from 9.1±1.1 to 3.7±0.8 mm (p<0.001) and a change in mean clinical attachment level (CAL) from 10.4±1.3 to 6.4±1.2 mm (p<0.001). At 5 years, mean PD and CAL measured 4.3±0.8 and 6.7±1.6 mm, respectively. At 5 years, both PD and CAL were statistically significantly improved compared with baseline (p<0.001) without statistically significant differences between the 1‐ and 5‐year results. In the control group, mean PD was reduced from 8.9±1.3 to 4.9±1.2 mm (p<0.001) and mean CAL changed from 10.6±1.4 to 8.8±1.5 mm (p<0.01). At 5 years, mean PD and CAL measured 5.6±1.1 and 9.1±1.3 mm, respectively, and were still statistically significantly improved compared with baseline (p<0.01). No statistically significant differences were found between the 1‐ and 5‐year results. The test treatment, at both 1 and 5 years, yielded statistically significantly higher CAL gains than the control one (p<0.01). Compared with baseline, at 5 years a CAL gain of 3 mm was found in nine defects (90%) of the test group but in none of the defects treated with OFD alone.Conclusions: It was concluded that (i) treatment of intra‐bony defects with OFD+NBM+GTR may result in significantly higher CAL gains than treatment with OFD, and (ii) the clinical results obtained after both treatments can be maintained over a period of 5 years.
A three‐year prospective study of adult subjects with gingivitis II: microbiological parameters
Authors: Teles R. P. , Bogren A. , Patel M. , Wennstrom J. L. , Socransky S. S. , Haffajee A. D. 
Published: December 2006

AbstractAim: To investigate whether the clinical benefits obtained with a periodontal prevention programme in subjects with periodontal health or minimal disease were accompanied by beneficial changes in the subgingival microbiota.Material and Methods: One hundred and twenty‐four subjects completed the study. Subjects were clinically and microbiologically monitored at baseline, 1, 2 and 3 years. Subgingival plaque samples were taken from the mesiobuccal aspect of every tooth and were analysed for the levels of 40 bacterial species using checkerboard DNA–DNA hybridization (total samples=13,477). The mean counts of each of the 40 test species were calculated for each subject at each time point. Significance of differences over time was sought using the Friedman test. p values were adjusted for multiple comparisons.Results: All clinical parameters, at the microbiologically sampled sites, improved over time. The clinical changes were accompanied by statistically significant decreases in the mean counts of 35 of the 40 test species. Major reductions occurred by year 2 for Actinomyces, Capnocytophaga, Campylobacter, Fusobacterium and Prevotella species. At year 3, there was a modest re‐growth of the majority of the species.Conclusions: The clinical improvements obtained through preventive measures were accompanied by a shift to a more host‐compatible subgingival microbiota.
Inflammatory inert poly(ethylene glycol)–protein wound dressing improves healing responses in partial‐ and full‐thickness wounds
Authors: Shingel Kirill I , Di Stabile Liliana , Marty Jean‐Paul , Faure Marie‐Pierre 
Published: December 2006

AbstractIn this study, a novel soft hydrogel system based on the poly(ethylene glycol)–protein conjugates was evaluated as an occlusive wound dressing material. The hydrogel material, referred by the name of BioAquacare™, contains up to 96% of the liquid and is formulated with phosphate‐buffered saline and safe preservative to control bacterial load in the open wounds. Performance of the BioAquacare™ as a wound dressing material was assessed in partial‐ and full‐thickness wounds in pigs. Wound analysis comprised macroscopic determination of the wound size, histological examination of the healing tissues and biochemical characterisation of wound exudates. The wounds treated with BioAquacare™ healed without any signs of inflammation, skin irritation, oedema or erythema. Cellular composition of the reepithelialised wounds was very similar to that of the normal skin, with a well‐developed stratum corneum and epithelial layer. It was observed that BioAquacare™ plays the role of a liquid compartment, which provides pronounced hydration effect and helps maintain a natural moist environment of the healing tissues. BioAquacare™ showed relatively low protein‐absorbing activity, absorbing predominantly low‐molecular‐weight molecules, including interleukin (IL)‐1β, IL‐6, transforming growth factor‐β1 and products of haemoglobin degradation. It is concluded that application of the moist BioAquacare™ dressing promotes fast reepithelialisation by creating favourable environment for keratinocytes proliferation and it also reduces scarring. The results show that BioAquacare™ can be considered as a safe, biocompatible and inflammatory inert wound dressing material.
Antibiotic‐taking experiences of undergraduate college students
Authors: Aronson Barbara S. 
Published: December 2006

AbstractPurpose: The purpose of this qualitative descriptive study was to explore the medication‐taking experiences of undergraduate college students prescribed short‐term antibiotic therapies and to describe factors influencing their adherence.Data sources: Thirty‐four undergraduate students prescribed antibiotics for treatment of an acute infectious illness at a large university health center were recruited to participate in this study. Semistructured telephone interviews were conducted after students finished their course of treatment. Qualitative descriptive content analysis was used to analyze the transcripts typed from the audio‐taped phone interviews.Conclusions: The main theme that emerged from the data was antibiotic‐taking self‐management. Most participants were able to adapt medication regimens into their daily routines, and used events in their day and specific reminder strategies to help them to remember to take their medications. This occurred despite an ever‐changing class and work schedule and being prescribed complex, lengthy antibiotic regimens. Most dosing errors occurred during times when schedules changed or students were off campus during weekends or college breaks. A small number of students discontinued therapy early because of side effects or forgetfulness.Implications for practice: By understanding factors that influence antibiotic adherence from a college student perspective, healthcare providers can suggest strategies to promote adherence that are tailored to the specific needs of this unique population.
Deficient Major Histocompatibility Complex-Linked Innate Murine Cytomegalovirus Immunity in MA/My.L-H2bMice and Viral Downregulation of H-2kClass I Proteins
Authors: Xie Xuefang , Dighe Abhijit , Clark Patricia , Sabastian Pearl , Buss Sarah , Brown Michael G. 
Published: December 2006

ABSTRACTNK cells are key effectors of innate immunity and host survival during cytomegalovirus (CMV) infection. Innate murine CMV (MCMV) resistance in MA/My mice requires Ly49H/m157-independent H-2k-linked NK cell control. Here we show that replacement of MA/My H-2kwith C57L H-2bsusceptibility genes led to a remarkable loss of innate virus immunity, though NK gamma interferon was induced in H-2band H-2kstrains shortly after infection. Thus, H-2bgenes expressed in C57L or MA/My.L-H2bare sufficient in alerting NK cells to intrusion but fail to support NK restraint of viral infection. In addition, novel H-2 recombinant strains were produced and utilized in a further refinement of a critical genetic interval controlling innate H-2k-linked MCMV resistance. Importantly, this analysis excluded the gene interval from Kkclass I through class II. The responsible gene(s) therefore resides in an interval spanning Dkclass Ia and more-distal major histocompatibility complex (MHC) nonclassical class Ib genes. Recently, the NK activation receptor Ly49P and MHC class I Dkproteins were genetically implicated in MCMV resistance, in part because Ly49P-expressing reporter T cells could specifically bind Dkmolecules on MCMV-infected mouse embryonic fibroblasts (MEFs). However, as we found that H-2kinnate resistance differs in the C57L or MA/My backgrounds and because MCMV very efficiently downregulates H-2kclass I proteins in L929 cells and primary MEFs shortly after infection, a Ly49P/Dkmodel should not fully explain H-2k-linked MCMV resistance.
Initiation of Hepatitis C Virus Infection Is Dependent on Cholesterol and Cooperativity between CD81 and Scavenger Receptor B Type I
Authors: Kapadia Sharookh B. , Barth Heidi , Baumert Thomas , McKeating Jane A. , Chisari Francis V. 
Published: December 2006

ABSTRACT
In the past several years, a number of cellular proteins have been identified as candidate entry receptors for hepatitis C virus (HCV) by using surrogate models of HCV infection. Among these, the tetraspanin CD81 and scavenger receptor B type I (SR-BI), both of which localize to specialized plasma membrane domains enriched in cholesterol, have been suggested to be key players in HCV entry. In the current study, we used a recently developed in vitro HCV infection system to demonstrate that both CD81 and SR-BI are required for authentic HCV infection in vitro, that they function cooperatively to initiate HCV infection, and that CD81-mediated HCV entry is, in part, dependent on membrane cholesterol.
Epstein-Barr Virus Latent Membrane Protein 2B (LMP2B) Modulates LMP2A Activity
Authors: Rovedo Mark , Longnecker Richard 
Published: December 2006

ABSTRACTLatent membrane protein 2A (LMP2A) and LMP2B are viral proteins expressed during Epstein-Barr virus (EBV) latency in EBV-infected B cells both in cell culture and in vivo. LMP2A has important roles in modulating B-cell receptor (BCR) signal transduction by associating with the cellular tyrosine kinases Lyn and Syk via specific phosphotyrosine motifs found within the LMP2A N-terminal tail domain. LMP2A has been shown to alter normal BCR signal transduction in B cells by reducing levels of Lyn and by blocking tyrosine phosphorylation and calcium mobilization following BCR cross-linking. Although little is currently known about the function of LMP2B in B cells, the similarity in structure between LMP2A and LMP2B suggests that they may localize to the same cellular compartments. To investigate the function of LMP2B, B-cell lines expressing LMP2A, LMP2B, LMP2A/LMP2B, and the relevant vector controls were analyzed. As was previously shown, cells expressing LMP2A had a dramatic block in normal BCR signal transduction as measured by calcium mobilization and tyrosine phosphorylation. There was no effect on BCR signal transduction in cells expressing LMP2B. Interestingly, when LMP2B was expressed in conjunction with LMP2A, there was a restoration of normal BCR signal transduction upon BCR cross-linking. The expression of LMP2B did not alter the cellular localization of LMP2A but did bind to and prevent the phosphorylation of LMP2A. A restoration of Lyn levels, but not a change in LMP2A levels, was also observed in cells coexpressing LMP2B with LMP2A. From these results, we conclude that LMP2B modulates LMP2A activity.
Extremely Rapid Spread of Human Immunodeficiency Virus Type 1 BF Recombinants in Argentina
Authors: Aulicino Paula C. , Holmes Edward C. , Rocco Carlos , Mangano Andrea , Sen Luisa 
Published: December 2006

ABSTRACT

The epidemic of human immunodeficiency virus type 1 (HIV-1) in Argentina is distinctive in that many infections are caused by subtype BF recombinant viruses. To determine their demographic history, we estimated the evolutionary rate, mode of population growth, and age of genetic diversity among 40 BF
vpu
sequences. This revealed one of the highest substitution rates reported for HIV-1, at 10.793 × 10
−3
substitutions per site per year, and a very rapid rate of population growth, with an initial mean epidemic doubling time of 3.72 months. This rapid population growth is compatible with an elevated fitness for subtype BF compared to that for “pure” B and F viruses.
Triggering of inflammatory response by myeloperoxidase-oxidized LDLAn oral presentation of the data was given before the Congress of the Beligian Society of Internal Medicine.
Authors: Boudjeltia Karim Zouaoui , Legssyer Ilham , Van Antwerpen Pierre , Kisoka Roger Lema , Babar Sajida , Moguilevsky Nicole , Delree Paul , Ducobu Jean , Remacle Claude , Vanhaeverbeek Michel , Brohee Dany 
Published: December 2006

The oxidation theory proposes that LDL oxidation is an early event in atherosclerosis and that oxidized LDL contributes to atherogenesis in triggering inflammation. In contrast to the copper-modified LDL, there are few studies using myeloperoxidase-modified LDL (Mox-LDL) as an inflammation inducer. Our aim is to test whether Mox-LDL could constitute a specific inducer of the inflammatory response. Albumin, which is the most abundant protein in plasma and which is present to an identical concentration of LDL in the intima, was used for comparison. The secretion of IL-8 by endothelial cells (Ea.hy926) and TNF-α by monocytes (THP-1) was measured in the cell medium after exposure of these cells to native LDL, native albumin, Mox-LDL, or Mox-albumin. We observed that Mox-LDL induced a 1.5- and 2-fold increase (ANOVA; P < 0.001) in IL-8 production at 100 µg/mL and 200 µg/mL, respectively. The incubation of THP-1 cells with Mox-LDL (100 µg/mL) increased the production of TNF-α 2-fold over the control. Native LDL, albumin, and Mox-albumin showed no effect in either cellular types. The myeloperoxidase-modified LDL increase in cytokine release by endothelial and monocyte cells and by firing both local and systemic inflammation could induce atherogenesis and its development.
A Prospective Study of the Transient Decrease in Ovarian Cancer Risk Following Childbirth
Authors: Liu Qin , Lambe Mats , Baik Inkyung , Cnattingius Sven , Riman Tomas , Ekbom Anders , Adami Hans-Olov , Hsieh Chung-Cheng 
Published: December 2006

Abstract
Epidemiologic evidence shows that the risk of ovarian cancer is decreased following childbirth. We examined the time points when the decreased risk of postpartum maternal ovarian cancer reaches the lowest point and whether the protective effect diminishes over time. A case-control study nested within the Swedish Fertility Register included 10,086 cases of epithelial ovarian cancer recorded in the Swedish Cancer Register from 1961 to 2001. From the Fertility Register, 49,249 eligible subjects matched to the cases by age were selected as controls. The analysis contrasted risk between adjacent parities through logistic regression models that included indicator variables representing each year of age, age at delivery, and time since delivery. Compared with nulliparous women, uniparous women had a transient decrease in maternal ovarian cancer risk at 2 years after delivery (spline-derived odds ratio, 0.71; 95% confidence interval, 0.53-0.95, for those delivered at age 25 years) and maintained a lower risk for 4 years postpartum. Similar transient decreases were observed in biparous women compared with uniparous women and in women with three parities compared with biparous women. The protective effect of childbearing seemed to diminish with time. The transient decrease in postpartum ovarian cancer risk may define the latent period required for pregnancy hormones in clearing out ovarian cells that have undergone early stages of malignant transformation. The period before the risk increases again could indicate the period required for ovarian cancer induction. (Cancer Epidemiol Biomarkers Prev 2006;15(12):2508–13)