bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical Evaluation of Demineralized Freeze‐Dried Bone Allograft and Enamel Matrix Derivative Versus Enamel Matrix Derivative Alone for the Treatment of Periodontal Osseous Defects in Humans
Authors: Gurinsky Brian S. , Mills Michael P. , Mellonig James T. 
Published: February 2005

Background: A recent study suggests that the addition of enamel matrix derivative to demineralized freeze‐dried bone allograft may enhance osseoinduction. The purpose of this study was to evaluate the use of demineralized freeze‐dried bone allograft (DFDBA) in combination with enamel matrix derivative (EMD + DFDBA) compared to enamel matrix derivative (EMD) alone in the treatment of human intrabony periodontal defects.Methods: Forty patients with a total of 67 sites (intrabony defect ≥3mm deep) were selected to participate in this single‐masked, parallel design, randomized, controlled clinical trial. Each subject received either EMD alone (34 sites) or in combination with DFDBA (33 sites). Soft tissue measurements included probing depth (PD), clinical attachment level (CAL), and recession. Hard tissue measurements included defect depth, alveolar crestal resorption, and defect morphology. Following 6 months of healing, all soft tissue measurements were repeated. Forty‐nine sites (EMD + DFDBA = 26 sites, EMD alone = 23 sites) were surgically reentered. Statistical analyses were performed using unpaired and paired Student t tests.Results: Analyses showed a significant improvement in soft tissue parameters for both treatment groups (P <0.001) as compared to preoperative measurements. There were no statistical differences between treatment groups. The probing depth reduction (PDR) for the EMD + DFDBA was 3.6 ± 0.2 mm, while the EMD alone had a PDR of 4.0 ± 0.3 mm. The CAL gain for the EMD + DFDBA group was 3.0 ± 0.3 mm and 3.2 ± 0.3 mm for the EMD alone group. The mean value for bone fill in the EMD + DFDBA group was 3.7 ± 0.2 mm (74.9%), while the EMD alone group demonstrated a mean bone fill of 2.6 ± 0.4 mm (55.3%). While there were no significant differences between the two treatments with regards to soft tissue measurements, the combination of EMD + DFDBA therapy yielded statistically significant improvements in bone fill, crestal resorption, and percentage of sites gaining greater than 50% and 90% bone fill when compared to EMD alone (P <0.001).Conclusion: The results of this study indicate that there may be an enhancement of hard tissue parameters when enamel matrix derivative is added to demineralized freeze‐dried bone allograft. J Periodontol 2004;75:1309‐1318.
Efficacy of Antibiotics Against Periodontopathogenic Bacteria Within Epithelial Cells: An In Vitro Study
Authors: Eick Sigrun , Pfister Wolfgang 
Published: February 2005

Background: Periodontopathogenic bacteria can invade and survive within epithelial cells, but susceptibility of intracellular infection to antibiotics used in periodontitis treatment has not been studied to date.Methods: KB cells were infected by Actinobacillus actinomycetemcomitans, strain NCTC 9710; Porphyromonas gingivalis, strains ATCC 33277 and JH16‐1; or Streptococcus constellatus, strain J012b. After 2, 4, and 12 hours the bactericidal effect of antibiotics (clindamycin, doxycycline, metronidazole, and moxifloxacin) on intracellular microorganisms was tested at a concentration up to the 100‐fold minimum inhibitory concentration (MIC) determined separately on planktonic bacteria.Results: The P. gingivalis strains differed in their invasiveness and ATCC 33277 was 100‐fold more invasive than JH16‐1. Doxycycline and clindamycin at a concentration 10‐fold MIC had no effect, but P. gingivalis intercellular infection was significantly reduced by metronidazole at 10‐fold MIC after 2 and 4 hours. Moxifloxacin was effective, but a 100‐fold MIC concentration was necessary to reduce P. gingivalis strains intracellular growth to 7% of the control. Other bacterial species grown inside the KB cells were more susceptible to antibiotics. Clindamycin at 10‐fold MIC reduced the number of intracellular S. constellatus after 4 and 12 hours. This bacterium was eliminated by moxifloxacin at 50‐fold MIC. Intracellular A. actinomycetemcomitans was killed by 10‐fold MIC of doxycycline and moxifloxacin after 4 hours incubation.Conclusions: Moxifloxacin was the most efficient antibiotic to treat intracellular infection. However, taking into account the MIC values and the levels of antibiotics in gingival fluid, elimination of intracellular bacteria by antibiotics alone seems to be questionable. J Periodontol 2004;75:1327‐1334.
Implant Survival in Periodontally Compromised Patients
Authors: Baelum Vibeke , Ellegaard Birgit 
Published: February 2005

Background: Relatively little is known on the longterm prognosis of implants inserted in partially edentulous, periodontally compromised patients.Methods: A total of 258 conventional implants, 57 two‐stage and 201 one‐stage implants, which were inserted in 32 and 108 patients, respectively, between June 1988 and June 2002 were followed with respect to their survival, as well as the periodontal parameters bone loss, probing depth, and bleeding on probing. All patients were periodontally compromised who had undergone periodontal surgery and were considered able to maintain a high standard of oral hygiene.Results: The 5‐year survival rates were 97% and 94%, respectively, for the two‐ and the one‐stage implants. The 10‐year survival rate remained high at 97% for the two‐stage implants, but had dropped to 78% for the onestage implants. Smoking, short implant length, and insertion during the later period (1995‐2002) were found to be associated with an increased failure rate.Conclusions: Implants placed in patients with a history of periodontitis have a 5‐year survival similar to that observed for implants installed in non‐diseased persons. Although the 10‐year survival of the one‐stage implants was somewhat lower than has been observed for non‐diseased patients, implant placement remains a good treatment alternative also for periodontally compromised patients. J Periodontol 2004;75:1404‐1412.
Effect of a 3% Potassium Oxalate Topical Application on Dentinal Hypersensitivity After Subgingival Scaling and Root Planing
Authors: Pillon Flávio L. , Romani Ingrid G. , Schmidt Édina R. 
Published: February 2005

Background: The present study aimed to verify the effect of a single application of 3% potassium oxalate gel compared to a placebo gel immediately after subgingival scaling and root planing (SRP) on dentinal hypersensitivity (DH).Methods: Fifteen patients undergoing periodontal treatment volunteered for this randomized controlled clinical trial. They presented with periodontitis on homologous contralateral canines and premolars, with complaints of dentinal hypersensitivity before periodontal therapy. Immediately after SRP under local anesthesia, the test and placebo agents were randomly applied on the cemento‐enamel junction. Evaluation of DH reduction after treatment was self‐reported, with assessment made by the patient's indication of how painful each treated tooth was on a visual analog scale (VAS) at baseline, and 7, 14, and 21 days post‐treatment. The results were analyzed by DH percent reduction for each observational moment in relation to baseline, for test and control teeth separately. Mean percent reductions for each group were compared by paired sample t test, with an alpha level of 0.05.Results: On day 7, percent reduction for the test and control groups was 29.4% and 13.4%, respectively. On day 14 it was 64.6% and 20.5%, and on day 21 it was 81% and 34.7%, respectively. Significant differences between treatments were observed at 14 and 21 days.Conclusion: It may be concluded that subgingival scaling and root planing followed by a single application of a 3% potassium oxalate gel resulted in a significantly higher reduction of dentinal hypersensitivity at 14 and 21 days, when compared to the placebo. J Periodontol 2004;75:1461‐1464.
DNA pooling analysis of 21 norepinephrine transporter gene SNPs with attention deficit hyperactivity disorder: No evidence for association
Authors: Xu Xiaohui , Knight Jo , Brookes Keeley , Mill Jonathan , Sham Pak , Craig Ian , Taylor Eric , Asherson Philip 
Published: February 2005

AbstractThe norepinephrine system is known to play a role in attentional and cognitive‐energetic mechanisms and is thought to be important in attention deficit hyperactivity disorder (ADHD). Stimulant medications are known to alter the activity of norepinephrine as well as dopamine in the synapse and the highly selective norepinephrine reuptake inhibitor, atomoxetine, is an effective treatment for ADHD symptoms. This study set out to investigate whether common polymorphisms within the norepinephrine transporter gene (NET1) are associated with DSM‐IV ADHD combined subtype, using a sample that has previously shown association with genes that affect the synaptic release and uptake of neurotransmitters; DAT1 and SNAP‐25. We identified 21 single nucleotide polymorphisms (SNPs) from publicly available databases that had minor allele frequencies ≥5% and span the NET1 genomic region, including those analyzed in previous studies of ADHD. DNA pooling was used to screen for associations using two case pools (n = 180 cases) and four control pools (n = 334 controls). We identified three SNPs that showed suggestive evidence for association using either case‐control or within family tests of association, however, none of these were significant after adjustment for the number of markers analyzed. We conclude that none of the markers show significant evidence of association with ADHD although we cannot rule out small genetic effects. © 2005 Wiley‐Liss, Inc.
In vitro evolution and characterization of a ligase ribozyme adapted to acidic conditions: Effect of further rounds of evolution
Authors: Miyamoto Yoshitaka , Teramoto Naozumi , Imanishi Yukio , Ito Yoshihiro 
Published: February 2005

AbstractA ligase ribozyme that accelerates the ligation reaction with an oligonucleotide under low pH conditions was identified by in vitro adaptation in a previous study. We examined the effects of further rounds of evolution to isolate a more active ribozyme. The ribozyme, which was obtained after four rounds of evolution, was randomly mutated, and the resultant RNA library was subjected to in vitro selection at low pH. One ribozyme isolated from the pool was found to react 8,000 times faster than the original b1 ribozyme at pH 4. The reaction rate of the isolated ribozyme was enhanced at various pH values, and its pH dependence was less than that of the original ribozyme or the ribozyme selected with four rounds of evolution. The reaction rate of the isolated ribozyme was reduced in the presence of 3′ primer, the sequence of which is complementary to the 3′ primer‐binding site of the ligase ribozyme. This inhibition induced by the primer oligonucleotide binding to the ribozyme 3′ region implies that the 3′ region plays a role in the ligation reaction of the ribozyme. © 2005 Wiley Periodicals, Inc.
A 4′‐Phosphopantetheinyl Transferase Mediates Non‐Ribosomal Peptide Synthetase Activation in Aspergillus fumigatus
Authors: Neville Claire , Murphy Alan , Kavanagh Kevin , Doyle Sean 
Published: February 2005

AbstractAspergillus fumigatus is a significant human pathogen. Non‐ribosomal peptide (NRP) synthesis is thought to be responsible for a significant proportion of toxin and siderophore production in the organism. Furthermore, it has been shown that 4′‐phosphopantetheinylation is required for the activation of key enzymes involved in non‐ribosomal peptide synthesis in other species. Here we report the cloning, recombinant expression and functional characterisation of a 4′‐phosphopantetheinyl transferase from A. fumigatus and the identification of an atypical NRP synthetase (Afpes1), spanning 14.3 kb. Phylogenetic analysis has shown that the NRP synthetase exhibits greatest identity to NRP synthetases from Metarhizium anisolpiae (PesA) and Alternaria brassicae (AbrePsy1). Northern hybridisation and RT‐PCR analysis have confirmed that both genes are expressed in A. fumigatus. A 120 kDa fragment of the A. fumigatus NRP synthetase, containing a putative thiolation domain, was cloned and expressed in the baculovirus expression system. Detection of a 4′‐phosphopantetheinylated peptide (SFSAMK) from this protein, by MALDI‐TOF mass spectrometric analysis after coincubation of the 4′‐phosphopantetheinyl transferase with the recombinant NRP synthetase fragment and acetyl CoA, confirms that it is competent to play a role in NRP synthetase activation in A. fumigatus. The 4′‐phosphopantetheinyl transferase also activates, by 4′‐phosphopantetheinylation, recombinant α‐aminoadipate reductase (Lys2p) from Candida albicans, a key enzyme involved in lysine biosynthesis.
Mechanism of Ni Film CVD with a Ni(ktfaa)2 Precursor on a Copper Substrate
Authors: Bakovets V. V. , Mitkin V. N. , Gelfond N. V. 
Published: February 2005

AbstractThe mechanisms of pyrolysis in He and reduction in H2 of a Ni(ktfaa)2 chelate and nickel film deposition on copper substrates are discussed. The Ni films produced by CVD with the Ni(ktfaa)2 chelate as a precursor are continuous. Pyrolysis of the Ni(ktfaa)2 chelate takes place above 300 °C. The hydrogen atmosphere allows the reaction temperature to be decreased to 213 °C, but the film deposition rate is low. 300 °C is the optimal temperature for continuous Ni film deposition on Cu substrates. The mechanism of hydrogen interaction with the adsorbed Ni(ktfaa)2 chelate is discussed.
Growth Kinetics, Composition, and Morphology of Co3O4 Thin Films Prepared by Pulsed Liquid‐Injection MOCVD
Authors: Burriel M. , Garcia G. , Santiso J. , Abrutis A. , Saltyte Z. , Figueras A. 
Published: February 2005

AbstractCobalt oxide films were grown by pulsed liquid injection MOCVD using Co(thd)2 dissolved in monoglyme as the precursor. The structure, morphology, and growth rate of the layers deposited on silicon substrates were studied as a function of solution concentration, deposition temperature, and oxygen partial pressure. X‐ray diffraction (XRD) of films deposited from 350 °C to 540 °C showed a pure Co3O4 spinel structure and no CoO was detected, even at the lowest oxygen pressure. X‐ray photoelectron spectroscopy (XPS) was used to study the surface composition and oxidation states. Surprisingly, XPS spectra recorded for most of the films seemed to correspond to CoO. This unexpected oxidation state on the surface was assigned to the effect of the high density of edges and corners present in the surface morphology.
CD4+ T cell immunity against the human papillomavirus‐18 E6 transforming protein in healthy donors: identification of promiscuous naturally processed epitopes
Authors: Facchinetti Valeria , Seresini Samantha , Longhi Renato , Garavaglia Claudio , Casorati Giulia , Protti Maria Pia 
Published: February 2005

AbstractInfection by ‘high‐risk’ human papillomaviruses (HPV) is associated with the development of neoplastic lesions. HPV‐18 is responsible for a very aggressive form of cancer and poor survival. As for other HPV types, immune surveillance has probably a role in the control of the infection. However, very little is known on HPV‐18 immunogenicity. CD4+ T cells from 16 healthy donors were tested ex vivo for reactivity to synthetic peptides corresponding to 3 sequences on the HPV‐18 E6 transforming protein predicted by bioinformatics as promiscuous HLA‐DR ligands, and to the recombinant E6 protein. We found 3 donors with CD4+ T cells that specifically proliferated in the presence of HPV‐18 E6 antigens and produced IFN‐γ in the presence of the E6 protein. We then propagated CD4+ T cell lines and clones from the responsive subjects to better characterize the recognized sequences. We show that E652–66 and E697–111 are indeed promiscuous and, most importantly, they contain naturally processed epitopes. Collectively, our data indicate that healthy donors may develop spontaneous CD4 immunity against HPV‐18 E6 epitopes, thus strongly suggesting the potential for this protein to elicit in the host a natural productive immune response.
Intra‐ and inter‐allelic ordering of T cell receptor β chain gene assembly
Authors: Khor Bernard , Sleckman Barry P. 
Published: February 2005

AbstractAllelic exclusion at the TCRβ locus mandates that gene assembly be regulated in a manner that permits feedback inhibition of further complete TCRβ rearrangements upon pre‐TCR expression. Here we show that assembly of TCRβ chain genes from Vβ, Dβ and Jβ gene segments is intra‐allelically ordered, proceeding primarily through DJβ, and not VDβ, intermediates. This ensures that Vβ to DJβ rearrangement, which can be feedback inhibited, is the final step in the assembly process. A newly assembled VDJβ rearrangement must be tested to determine if it is in‐frame before Vβ to DJβ rearrangement is permitted on the alternate allele. This inter‐allelic ordering may occur through a general inefficiency of Vβ to DJβ rearrangement and/or through static differences in accessibility of the two TCRβ alleles. However, we find that within the regulatory context of allelic exclusion, Vβ to DJβ rearrangement proceeds to completion on both alleles. Furthermore, all possible VDJβ rearrangements are not completed on one allele before Vβ to DJβ rearrangement is initiated on the alternate allele. Together, these data support a dynamic model of inter‐allelic accessibility that permits the ordered and efficient assembly of complete variable region genes on both TCRβ alleles during T cell development.
Sexual dimorphism of growth plate prehypertrophic and hypertrophic chondrocytes in response to testosterone requires metabolism to dihydrotestosterone (DHT) by steroid 5‐alpha reductase type 1
Authors: Raz P. , Nasatzky E. , Boyan B.D. , Ornoy A. , Schwartz Z. 
Published: February 2005

AbstractRat costochondral growth plate chondrocytes exhibit sex‐specific and cell maturation dependent responses to testosterone. Only male cells respond to testosterone, although testosterone receptors are present in both male and female cells, suggesting other mechanisms are involved. We examined the hypothesis that the sex‐specific response of rat costochondral cartilage cells to testosterone requires further metabolism of the hormone to dihydrotestosterone (DHT). Resting zone (RC) and growth zone (GC, prehypertrophic and upper hypertrophic zones) chondrocytes from male and female Sabra strain rats exhibited sex‐specific responses to testosterone and DHT: only male cells were responsive. Testosterone and DHT treatment for 24 h caused a comparable dose‐dependent increase in [3H]‐thymidine incorporation in quiescent preconfluent cultures of male GC cells, and a comparable increase in alkaline phosphatase specific activity in confluent cultures. RC cells responded in a differential manner to testosterone and DHT. Testosterone decreased DNA synthesis in male RC cells but DHT had no effect and alkaline phosphatase specific activity of male RC cells was unaffected by either hormone. Inhibition of steroid 5α‐reductase activity with finasteride (1, 5, or 10 μg/ml), reduced the response of male GC cells to testosterone in a dose‐dependent manner, indicating that metabolism to DHT was required. RT‐PCR showed that both male and female cells expressed mRNAs for steroid 5α‐reductase type 1 but lacked mRNAs for the type 2 form of the enzyme. Male cells also exhibited 5α‐reductase activity but activity of this enzyme was undetectable in female cells. These observations show that sex‐specific responses of rat growth zone chondrocytes to testosterone requires the further metabolism of the hormone to DHT and that the effect of DHT in the male growth plate is maturation‐state dependent. Failure of female chondrocytes to respond to testosterone may reflect differences in testosterone metabolism, since these cells possess greater ability to aromatize the hormone to estradiol. © 2004 Wiley‐Liss, Inc.
Over‐expression of fibroblast growth factor‐2 causes defective bone mineralization and osteopenia in transgenic mice
Authors: Sobue T. , Naganawa T. , Xiao L. , Okada Y. , Tanaka Y. , Ito M. , Okimoto N. , Nakamura T. , Coffin J.D. , Hurley M.M. 
Published: February 2005

AbstractOver‐expression of human FGF‐2 cDNA linked to the phosphoglycerate kinase promoter in transgenic (TgFGF2) mice resulted in a dwarf mouse with premature closure of the growth plate and shortening of bone length. This study was designed to further characterize bone structure and remodeling in these mice. Bones of 1–6 month‐old wild (NTg) and TgFGF2 mice were studied. FGF‐2 protein levels were higher in bones of TgFGF2 mice. Bone mineral density was significantly decreased as early as 1 month in femurs from TgFGF2 mice compared with NTg mice. Micro‐CT of trabecular bone of the distal femurs from 6‐month‐old TgFGF2 mice revealed significant reduction in trabecular bone volume, trabecular number (Tb.N), and increased trabecular separation (Tb.Sp). Osteoblast surface/bone surface, double‐labeled surface, mineral apposition rate, and bone formation rates were all significantly reduced in TgFGF2 mice. There were fewer TRAP positive osteoclasts in calvaria from TgFGF2 mice. Quantitative histomorphometry showed that total bone area was similar in both genotypes, however percent osteoclast surface, and osteoclast number/bone surface were significantly reduced in TgFGF2 mice. Increased replication of TgFGF2 calvarial osteoblasts was observed and primary cultures of bone marrow stromal cells from TgFGF2 expressed markers of mature osteoblasts but formed fewer mineralized nodules. The data presented indicate that non‐targeted over‐expression of FGF‐2 protein resulted in decreased endochondral and intramembranous bone formation. These results are consistent with FGF‐2 functioning as a negative regulator of postnatal bone growth and remodeling in this animal model. © 2005 Wiley‐Liss, Inc.
Spatio‐temporal organization of DNA replication in murine embryonic stem, primary, and immortalized cells
Authors: Panning Margaret M. , Gilbert David M. 
Published: February 2005

AbstractThe extent to which chromosomal domains are reorganized within the nucleus during differentiation is central to our understanding of how cells become committed to specific developmental lineages. Spatio‐temporal patterns of DNA replication are a reflection of this organization. Here, we demonstrate that the temporal order and relative duration of these replication patterns during S‐phase are similar in murine pluripotent embryonic stem (ES) cells, primary adult myoblasts, and an immortalized fibroblast line. The observed patterns were independent of fixation and denaturation techniques. Importantly, the same patterns were detected when fluorescent nucleotides were introduced into living cells, demonstrating their physiological relevance. These data suggest that heritable gene silencing during commitment to specific cell lineages is not mediated by global changes in the sub‐nuclear organization and replication timing of chromosome domains. © 2004 Wiley‐Liss, Inc.