bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional confocal morphometry – a new approach for studying dynamic changes in cell morphology in brain slices
Authors: Chvátal Alexandr , Anděrová Miroslava , Kirchhoff Frank 
Published: May 2007

AbstractPathological states in the central nervous system lead to dramatic changes in the activity of neuroactive substances in the extracellular space, to changes in ionic homeostasis and often to cell swelling. To quantify changes in cell morphology over a certain period of time, we employed a new technique, three‐dimensional confocal morphometry. In our experiments, performed on enhanced green fluorescent protein/glial fibrillary acidic protein astrocytes in brain slices in situ and thus preserving the extracellular microenvironment, confocal morphometry revealed that the application of hypotonic solution evoked two types of volume change. In one population of astrocytes, hypotonic stress evoked small cell volume changes followed by a regulatory volume decrease, while in the second population volume changes were significantly larger without subsequent volume regulation. Three‐dimensional cell reconstruction revealed that even though the total astrocyte volume increased during hypotonic stress, the morphological changes in various cell compartments and processes were more complex than have been previously shown, including swelling, shrinking and structural rearrangement. Our data show that astrocytes in brain slices in situ during hypotonic stress display complex behaviour. One population of astrocytes is highly capable of cell volume regulation, while the second population is characterized by prominent cell swelling, accompanied by plastic changes in morphology. It is possible to speculate that these two astrocyte populations play different roles during physiological and pathological states.
Methods of DNA extraction and PCR amplification for individual freshwater mussel (Bivalvia: Unionidae) glochidia, with the first report of multiple paternity in these organisms
Authors: CHRISTIAN ALAN D. , MONROE EMY M. , ASHER ALLISON M. , LOUTSCH JEANNETTE M. , BERG DAVID J. 
Published: May 2007

AbstractFreshwater mussels (Unionidae) are among North America's most imperilled organisms. Mussels produce small larvae (glochidia) that parasitize aquatic vertebrates. We modified the Epicentre QuickExtract protocol to extract DNA from a single glochidium, collected directly from the marsupium of a female mussel, to use as template in polymerase chain reactions (PCRs). Yield per glochidium in a 40 µL extraction volume provided enough DNA for ≥ 15 PCRs per individual. We were successful in using this DNA for microsatellite analysis of up to three loci per individual. Offspring from one female showed evidence for multiple paternity within her brood. Our results are the first documentation of this phenomenon in freshwater mussels.
Isolation and characterization of microsatellite markers for red elm (Ulmus rubra Muhl.) and cross‐species amplification with Siberian elm (Ulmus pumila L.)
Authors: ZALAPA J. E. , BRUNET J. , GURIES R. P. 
Published: May 2007

Abstract Ulmus pumila is an elm species, non‐native to the USA that hybridizes with Ulmus rubra. In order to study the genetic structure and hybridization patterns between these two elm species, we developed 15 primer pairs for microsatellite loci in U. rubra and tested their cross‐amplification in U. pumila. All 15 primers amplified in both species, 11 of which possessed species‐specific alleles. Eight loci were polymorphic in U. pumila and eight in U. rubra, each with two to eight alleles per locus. In addition, five primer pairs previously developed in U. laevis and U. carpinifolia (syn. U. minor) cross‐amplified and showed polymorphic loci in U. pumila and/or U. rubra. These markers will facilitate the study of genetic structure and gene flow between U. rubra and exotic, invasive U. pumila.
13C‐urea Breath Test during Hospitalization for the Diagnosis of Helicobacter pylori Infection in Peptic Ulcer Bleeding
Authors: Gisbert Javier P. , Esteban Carlos , Jimenez Isabel , Moreno‐Otero Ricardo 
Published: May 2007

AbstractObjective:  To evaluate the accuracy of 13C‐urea breath test (UBT) to detect Helicobacter pylori infection in patients hospitalized with peptic ulcer bleeding and treated with proton pump inhibitors (PPIs).Methods:  Patients hospitalized with peptic ulcer bleeding, and treated with omeprazole, had a first UBT performed the day after resuming oral feeding. Patients with a negative UBT during hospitalization underwent a repeated UBT 15 days after stopping PPIs.Results:  The first UBT during hospitalization was positive in 86% of 131 patients. Time between admission and performance of the test was longer in patients with negative versus positive UBT (5.2 ± 0.7 versus 4.3 ± 0.5 days; p < .001). The repeated UBT became positive in 15 of 18 (83%) patients with a negative first UBT. In the multivariate analysis, the only variable associated with a negative first UBT was the time elapsed between admission and performance of the test (odds ratio = 6.6; 95%CI = 2.9–15.1).Conclusion:  Most H. pylori‐positive patients with ulcer bleeding have a positive UBT (performed just after resuming oral feeding) despite previous treatment with high‐dose PPIs. Nevertheless, to preclude false‐negative results due to PPI therapy, the UBT should be performed as early as possible. If the infection cannot be demonstrated with this first UBT, H. pylori still needs to be definitively excluded with a second UBT performed after stopping PPIs.
Immune and Proliferative Cellular Responses to Helicobacter pylori Infection in the Gastric Mucosa of Mexican Children
Authors: Muñoz Leopoldo , Camorlinga M. , Hernández R. , Giono S. , Ramón G. , Muñoz O. , Torres J. 
Published: May 2007

AbstractBackground:  Helicobacter pylori infection occurs mostly during childhood, but few studies on this age group have addressed the innate immune and the proliferative response to this infection. Mexico has a high H. pylori prevalence in children, but a low risk of gastric cancer. The aim of this work was to study the cellular responses of the gastric mucosa to this infection in Mexican children.Methods:  Antral and corpus gastric biopsies were obtained from 44 H. pylori‐infected children (mean age 12 ± 3.2 years) and 44 uninfected children (mean age 10 ± 3 years). Mucosal cellular responses were studied by immunohistochemistry, using anti‐Ki67 antibodies for proliferation studies, antihuman tryptase for mast cells, and antihuman CD68 for macrophages. T and B lymphocytes were stained with a commercial integrated system. The intensity of cellular responses was estimated histologically using the software ks300.Results:  Epithelium proliferation and infiltration of macrophages and T and B lymphocytes were significantly higher in H. pylori‐infected than in uninfected children. A balanced increase of CD4, CD8, and CD20 lymphocytes was observed in infected children. However, activated mast cells were decreased, and infiltration of neutrophil and mononuclear cells was low. Epithelial proliferation was associated with polymorphonuclear infiltration but not with infiltration of macrophages or lymphocytes. Inflammation and proliferation was higher in CagA (+)‐infected children.Conclusions:  Mexican children respond to H. pylori infection with a low inflammatory response, a balanced increase of T and B lymphocytes, and a high regenerative activity.
Enhanced Activation of Cyclooxygenase‐2 Downregulates Th1 Signaling Pathway in Helicobacter pylori‐infected Human Gastric Mucosa
Authors: Pellicanò Antonia , Imeneo Maria , Leone Isabella , Larussa Tiziana , Luzza Francesco 
Published: May 2007

AbstractBackground:  Evidence suggests that an impaired T‐cell response against Helicobacter pylori plays a role in the pathogenesis of H. pylori‐related diseases. Cyclooxygenase (COX) 2 has been shown to inhibit the production of T‐helper (Th) 1 cytokines. This study aimed to ascertain whether COX‐2 downregulates Th1 signaling pathway in human gastric mucosa colonized by H. pylori.Methods:  COX‐2 expression and prostaglandin E2 (PGE2) production were determined in total proteins extracted from freshly obtained gastric biopsies of H. pylori‐infected and uninfected patients by Western blotting and enzyme‐linked immunosorbent assay (ELISA). Phosphorylated (p)STAT4, pSTAT1, T‐bet, and pSTAT6 expression and interleukin (IL)‐12, interferon (IFN)‐γ, and IL‐4 production were also determined by Western blotting and ELISA, respectively, in total protein extracts from gastric biopsy cultures of H. pylori‐infected patients treated without and with COX‐2 inhibitor NS‐398.Results:  Enhanced expression of COX‐2 and production of PGE2 was found in H. pylori‐infected compared to uninfected patients. COX‐2 inhibition significantly increased expression of Th1 transcription factors along with production of IL‐12 and IFN‐γ. By contrast, no changes in the expression of STAT6 and production of IL‐4 were found.Conclusion:  This study provides a mechanism by which H. pylori may actually interfere with normal T‐cell activation in human gastric mucosa, possibly enhancing its pathogenicity. The use of COX‐2 selective inhibitors as immunomodulators in the course of H. pylori infection deserves investigations.
CHARACTERIZATION OF A DINOFLAGELLATE CRYPTOCHROME BLUE‐LIGHT RECEPTOR WITH A POSSIBLE ROLE IN CIRCADIAN CONTROL OF THE CELL CYCLE1
Authors: Brunelle Stephanie A. , Hazard E. Starr , Sotka Erik E. , Dolah Frances M. Van 
Published: May 2007

Karenia brevis (C. C. Davis) G. Hansen et Moestrup is a dinoflagellate responsible for red tides in the Gulf of Mexico. The signaling pathways regulating its cell cycle are of interest because they are the key to the formation of toxic blooms that cause mass marine animal die‐offs and human illness. Karenia brevis displays phased cell division, in which cells enter S phase at precise times relative to the onset of light. Here, we demonstrate that a circadian rhythm underlies this behavior and that light quality affects the rate of cell‐cycle progression: in blue light, K. brevis entered the S phase early relative to its behavior in white light of similar intensity, whereas in red light, K. brevis was not affected. A data base of 25,000 K. brevis expressed sequence tags (ESTs) revealed several sequences with similarity to cryptochrome blue‐light receptors, but none related to known red‐light receptors. We characterized the K. brevis cryptochrome (Kb CRY) and modeled its three‐dimensional protein structure. Phylogenetic analysis of the photolyase/CRY gene family showed that Kb CRY is a member of the cryptochrome DASH (CRY DASH) clade. Western blotting with an antibody designed to bind a conserved peptide within Kb CRY identified a single band at ∼55 kDa. Immunolocalization showed that Kb CRY, like CRY DASH in Arabidopsis, is localized to the chloroplast. This is the first blue‐light receptor to be characterized in a dinoflagellate. As the Kb CRY appears to be the only blue‐light receptor expressed, it is a likely candidate for circadian entrainment of the cell cycle.
IDENTIFICATION AND COMPARATIVE GENOMIC ANALYSIS OF SIGNALING AND REGULATORY COMPONENTS IN THE DIATOM THALASSIOSIRA PSEUDONANA1
Authors: Montsant Anton , Allen Andrew E. , Coesel Sacha , Martino Alessandra De , Falciatore Angela , Mangogna Manuela , Siaut Magali , Heijde Marc , Jabbari Kamel , Maheswari Uma , Rayko Edda , Vardi Assaf , Apt Kirk E. , Berges John A. , Chiovitti Anthony , Davis Aubrey K. , Thamatrakoln Kimberlee , Hadi Masood Z. , Lane Todd W. , Lippmeier J. Casey , Martinez Diego , Parker Micaela S. , Pazour Gregory J. , Saito Mak A. , Rokhsar Dan S. , Armbrust E. Virginia , Bowler Chris 
Published: May 2007

Diatoms are unicellular brown algae that likely arose from the endocytobiosis of a red alga into a single‐celled heterotroph and that constitute an algal class of major importance in phytoplankton communities around the globe. The first whole‐genome sequence from a diatom species, Thalassiosira pseudonana Hasle et Heimdal, was recently reported, and features that are central to diatom physiology and ecology, such as silicon and nitrogen metabolism, iron uptake, and carbon concentration mechanisms, were described. Following this initial study, the basic cellular systems controlling cell signaling, gene expression, cytoskeletal structures, and response to stress have been cataloged in an attempt to obtain a global view of the molecular foundations that sustain such an ecologically successful group of organisms. Comparative analysis with several microbial, plant, and metazoan complete genome sequences allowed the identification of putative membrane receptors, signaling proteins, and other components of central interest to diatom ecophysiology and evolution. Thalassiosira pseudonana likely perceives light through a novel phytochrome and several cryptochrome photoreceptors; it may lack the conserved RHO small‐GTPase subfamily of cell‐polarity regulators, despite undergoing polarized cell‐wall synthesis; and it possesses an unusually large number of heat‐shock transcription factors, which may indicate the central importance of transcriptional responses to environmental stress. The availability of the complete gene repertoire will permit a detailed biochemical and genetic analysis of how diatoms prosper in aquatic environments and will contribute to the understanding of eukaryotic evolution.
A Quality Assessment of the Casting Process on Magnetic Keepers
Authors: Luk Henry W.K. , Pow Edmond H.N. , Dias Andrew P.L.H. 
Published: May 2007

Purpose: The objective of this study was to qualitatively investigate the effect of the burn‐out (mold) temperature, investment material, and casting alloy on the surface integrity of the Magfit EX keeper.
Materials and Methods: Forty‐two Magfit EX keepers were waxed‐up, invested in five investment materials (Beauty‐Cast, Cristobalite, CM‐10, Cera‐Fina, Castorit‐super), and subjected to burn‐out temperatures ranging from 450 to 700°C at intervals of 50°C. The keeper samples were then cast into copings with three alloys (Castwell, Protor 3, Optimum) under standard conditions. The keeper surfaces were then examined under a microscope, and the compositions were assessed by an X‐ray micro‐analyzer in a scanning electron microscope (SEM). A new keeper served as control.
Results: At a burn‐out temperature of 550°C, the keeper surface started to disintegrate. X‐ray micro‐analysis showed an increase in oxygen content with increasing temperature. At 700°C, the keeper surface disintegrated, and the composition differed markedly from that of the new keeper. The keeper surfaces were intact with all investments except those with Beauty‐Cast. The keeper surfaces were found to be damaged when the casting alloy was Optimum.
Conclusions: Beauty‐Cast investment with a burn‐out temperature of 700°C is unsuitable for casting the Magfit EX keeper‐coping unit. Also, high fusing alloys are not recommended for casting Magfit EX keepers.
Precision of Fit of Two Margin Designs for Metal‐Ceramic Crowns
Authors: Limkangwalmongkol Penwadee , Chiche Gerard J. , Blatz Markus B. 
Published: May 2007

Statement of Problem: Although metal‐ceramic restorations are widely used, there is a lack of information about how the fit is affected by margin designs.
Purpose: This study measured and compared the precision of fit of metal‐ceramic crowns with two margin designs.
Material and Methods: Thirty‐two extracted human premolar teeth were prepared for complete‐coverage restorations with an internally rounded shoulder preparation. Impressions were made from all teeth, and master dies were poured with improved stone type V. MC crowns were fabricated with a porcelain‐butt margin on the buccal aspect (n = 32) and a feather‐edge metal margin on the lingual aspect (n = 32), which served as a control group. Precision of fit was measured three times at the mid‐buccal and mid‐lingual margins of each crown with a profilometer. The data were statistically analyzed with the paired t‐test (α < .05).
Results: Mean marginal gap size of porcelain‐butt margins was 27.93 μm (±15.84) and of feather‐edge metal margins 42.43 μm (±24.12). The marginal gap size of feather‐edge metal margins was statistically significantly greater than that of porcelain‐butt margins (p = 0.0045).
Conclusion: The marginal fit of porcelain‐butt margins was significantly better than that of feather‐edge metal margins.
Clinical Implications
: Porcelain‐butt margins in this study had a better marginal fit than feather‐edge metal margins, and thus have given clinicians evidence to prefer the use of porcelain‐butt margins.
Effect of Different Finishing and Polishing Agents on the Surface Roughness of Cast Pure Titanium
Authors: Reddy E. Srinivas , Patil Narendra P. , Guttal Satyabodh S. , Jagadish H.G. 
Published: May 2007

Purpose:
The aim of this study was to evaluate the effect of finishing and polishing agents on surface roughness of cast commercially pure titanium using scanning electron microscope (SEM) analysis.
Materials and Methods:
A standardized square steel die measuring 10 × 10 mm with a thickness of 2 mm was machine cut. An impression of this die was used to create wax patterns for casting. Sixty specimens were cast in commercially pure titanium. These were divided into three groups (A, B, and C) of 20 specimens each. Group A specimens were polished with black, brown, and green rubber discs followed by green polishing compound with buff. Group B specimens were polished with black, brown, and green rubber cones, buffed with yellow polishing cake designed for gold alloy. Group C specimens were polished with silicium carbide cones and buffed with orange polishing cake. Surface roughness of the test specimens was measured in microns with a perthometer. Data were analyzed with ANOVA and Tukey's honest significant difference (HSD) multiple comparison tests among the different groups. Qualitative analysis was done by SEM photomicrographs.
Results:
Surface roughness values Ra for Groups A, B, and C were 0.68 μm, 0.78 μm, and 0.27 μm, respectively. SEM photomicrographs and the statistical analysis revealed that the finishing and polishing were better with Group C test specimens with lower surface roughness values compared with groups A and B. Tests showed that Group C was statistically smoother (p< 0.01).
Conclusion:
Within the limitations of this study, surface roughness was less on cast CpTi specimens that were finished and polished from the cutters designed specifically for titanium.
The Effect of Water Immersion on the Shear Bond Strength Between Chairside Reline and Denture Base Acrylic Resins
Authors: Azevedo Andrea , Machado Ana Lucia , Giampaolo Eunice Teresinha , Pavarina Ana Claudia , Vergani Carlos Eduardo 
Published: May 2007

Purpose: The effect of water immersion on the shear bond strength (SBS) between 1 heat‐polymerizing acrylic resin (Lucitone 550‐L) and 4 autopolymerizing reline resins (Kooliner‐K, New Truliner‐N, Tokuso Rebase Fast‐T, Ufi Gel Hard‐U) was investigated. Specimens relined with resin L were also evaluated.
Materials and Methods: One hundred sixty cylinders (20 × 20 mm) of L denture base resin were processed, and the reline resins were packed on the prepared bonding surfaces using a split‐mold (3.5 × 5.0 mm). Shear tests (0.5 mm/min) were performed on the specimens (n = 8) after polymerization (control), and after immersion in water at 37°C for 7, 90, and 180 days. All fractured surfaces were examined by scanning electron microscopy (SEM) to calculate the percentage of cohesive fracture (PCF). Shear data were analyzed with 2‐way ANOVA and Tukey's test; Kruskall‐Wallis test was used to analyze PCF data (α= 0.05).
Results: After 90 days water immersion, an increase in the mean SBS was observed for U (11.13 to 16.53 MPa; p < 0.001) and T (9.08 to 13.24 MPa, p= 0.035), whereas resin L showed a decrease (21.74 MPa to 14.96 MPa; p < 0.001). The SBS of resins K (8.44 MPa) and N (7.98 MPa) remained unaffected. The mean PCF was lower than 32.6% for K, N, and T, and higher than 65.6% for U and L.
Conclusions: Long‐term water immersion did not adversely affect the bond of materials K, N, T, and U and decreased the values of resin L. Materials L and U failed cohesively, and K, N, and T failed adhesively.
Optimization of Tooth Color and Shade Guide Design
Authors: Paravina Rade D. , Majkic Goran , Imai Francisco H. , Powers John M. 
Published: May 2007

Purpose:
One critical prerequisite for dental shade guides is to match the color range and distribution of human teeth. The purpose of this study was to design computer models for dental shade guides and compare them with an existing shade guide. A targeted coverage error for a newly developed shade guide was ΔEab < 2 with a corresponding CIE2000 value.
Materials and Methods:
A total of 1064 teeth were evaluated in vivo using an intra‐oral spectrophotometer. Shade guide models were designed using different methods for representation of the data set, hierarchical clustering, and nonlinear constrained optimization. Coverage error was calculated for both CIELAB and CIE2000 values. Recorded values were compared with coverage error of Vitapan Classical (VC) shade guide. Wilcoxon signed‐rank test for paired samples and linear regression were used in statistical analysis.
Results:
Coverage error of VC was 4.1 (SD 1.8), ranging from 0.5 to 11.5 ΔEab. Group A shades had the best match for human teeth (43.9%) followed by Groups C (24.1%), B (20.4%), and D (11.7%) shades, respectively. CIELAB coverage error of the newly designed 24‐tab shade guide using clustering and optimization was 2.05 (0.95) and 1.96 (0.92), respectively. Corresponding CIE2000 coverage error values were 1.43 (0.68) and 1.40 (0.65), respectively. A significant difference between results obtained using clustering and optimization was determined. CIELAB color differences were greater, but highly correlated as compared with their CIE2000 counterparts (ΔE00= 0.64 ×ΔE76+ 0.13, r > 0.99).
Discussion:
This study demonstrated that, compared with existing shade guides, future shade guides can provide either (a) similar coverage of tooth color with fewer tabs, thus simplifying shade matching procedure, or (b) better coverage of tooth color with a similar number of tabs, in both cases increasing the chances of satisfactory matches and, consequently, better esthetics.
Conclusions:
Both clustering and optimization enabled better representation of tooth color as compared with an existing dental shade guide. Optimization outperformed clustering and is therefore recommended as a method of choice for representation of tooth color and designing of dental shade guides.
Prolonged hemostatic ability of polyethylene glycol–modified polymerized albumin particles carrying fibrinogen γ‐chain dodecapeptide
Authors: Okamura Yosuke , Fujie Toshinori , Maruyama Hitomi , Handa Makoto , Ikeda Yasuo , Takeoka Shinji 
Published: May 2007

BACKGROUND: Second‐generation platelet (PLT) substitutes for treatment of bleeding were studied and the focus was on a dodecapeptide, HHLGGAKQAGDV (H12), which is a fibrinogen γ‐chain carboxy‐terminal sequence (γ 400‐411) and exists only in a fibrinogen domain.STUDY DESIGN AND METHODS: H12 was conjugated to the surface of polymerized albumin particles (polyAlb) modified with polyethylene glycol (PEG) chains to produce biocompatible particles (H12‐PEG‐polyAlb) that had prolonged blood circulation t½ and were more stable in vitro and in vivo compared with H12‐polyAlb (not modified with PEG). H12‐PEG‐polyAlb was administered intravenously into thrombocytopenic rats and the t½ of the particles and the tail bleeding time were measured to evaluate the prolongation in the hemostatic effect.RESULTS: H12‐PEG‐polyAlb particles modified with PEG prolonged the t½ and maintained specific binding ability to activated PLTs. The particles dose dependently shortened the tail bleeding time of thrombocytopenic rats 6 hours after injection.CONCLUSION: H12‐PEG‐polyAlb may be a suitable candidate for treatment of bleeding into thrombocytopenic patients as an alternative to PLT concentrate transfusion.