bluuebunny/crossref_metadata_2025_split huggingface dataset:
A scanning electron microscope study of the three‐dimensional extent of Retzius lines in human dental enamel
Authors: RISNES STEINAR 
Published: October 2007

Abstract –A method involving carefully planned sectioning and grinding of human maxillary first premolars, allowing enamel structure to be studied with the SEM in more than one plane at the same time, was employed to demonstrate the extent of Retzius lines within the confines of the three‐dimensional enamel cap. It was found that the Retzius lines behaved as could be predicted by the theory stating that the striae represent one‐dimensional cuts of two‐dimensional, curved growth planes. Retzius lines in adjoining planes were continuous across the edge where the two planes met. In a supernumerary tooth, the surface of its hypoplaslic tooth tip was continuous with distinct Retzius lines. The present observations provide for the first time direct morphologic verification of the supposed nature of Retzius lines, with reference to extent and continuity in three‐dimensional space.
Inactivation of guinea‐pig serum proteinase inhibitors by Bacteroides gingivalis
Authors: HERRMANN BJÖRN F. , CARLSSON JAN , SUNDQVIST GÖRAN K. 
Published: October 2007

Abstract –The activity of proteinase inhibitors of guinea‐pig serum was evaluated by using trypsin as test enzyme. Strains of black‐pigmcnted Bacteroides species were incubated with serum under anaerobic conditions. Strains of Bacteroides gingivalis inactivated the trypsin inhibitors of guinea‐pig serum within 1 h, while the other strains reduced the activity of the trypsin inhibitors by less than 50% within 48 h. The inactivation of proteinase inhibitors of guinea‐pig serum by B. gingivalis may be an important pathogenic mechanism in the spreading necrotic infections induced in guinea pigs by pure cultures of this species.
Influence of antiseptic storage solutions on physical properties of endodontic guttapercha points
Authors: MÖLLER BENGT , ÖRSTAVIK DAG 
Published: October 2007

Abstract –The effect of three commonly used antiseptic storage solutions on some physical properties of endodontic guttapercha points was studied. The solutions tested were: 70% isopropyl alcohol, 5% chloramine and 0.5% chlorhexidine. As a control solution, physiologic saline was used. There was a marked decrease in the force necessary to bend the points after 1 month. With few exceptions, the greatest decrease was seen with solutions containing alcohol, i.e. chlorhexidine and isopropyl alcohol. The difference between aqueous and alcoholic storage solutions was also noted for linear dimensional changes. Physiologic saline and chloramine hardly affected the length of the points. The decrease in stiffness may add to the difficulties when handling guttapercha points of small dimensions in curved root canals. From this point of view it is therefore recommended to avoid storage of points in antibacterial solutions. Rather, an effective surface disinfecting of the points immediately prior to use would be desirable.
Dual‐photon absorptiometry of mandibles: in vitro test of a new method
Authors: VON WOVERN NINA 
Published: October 2007

Abstract –A new method for non‐invasive in vivo measurement of changes in bone mineral content (BMC) of mandibles, comprising two‐dimensional dual‐photon absorptiometry (GT45), has been developed and tested in vitro on mandibular specimens. The analysis showed that: 1) in vitro precision and accuracy of the methods are high, 2) effect of fat and soft tissue on photon attenuation is slight when scanning jaws and forearm bones, 3) BMC in units (U/cm2) in standard area, comprising mandibular base and body in left molar region, is representative for BMC in total mandibular base and body, 4) cortical bone constitutes the main part of measured BMC in mandibles, and 5) BMC of molar region is highly correlated to cortical bone mass in mm3/mm2 subperiosteal surface of standard locality anterior to and below mental foramen, measured by histomorphometry. GT45 seems suitable for in vivo estimation of BMC changes in edentulous jaws and in mandibular base and body of dentate mandibles in longitudinal and cross‐sectional studies. The radiation dose is negligible.
Electron microscopic demonstration of non‐mineralized and hypomineralized areas in dentin and cementurn by silver methenamine staining of collagen
Authors: MATTHIESSEN MARTIN EBBE , SÖGAARD‐PEDERSEN BO , RÖMERT PAUL 
Published: October 2007

Abstract –An electron microscopic, study on silver methenamine staining of hard dental tissues was made on a material that comprised human permanent teeth and primary tooth germs from human and porcine fetuses. It was demonstrated that silver‐stained material consisted of collagen fibrils. In predentin and precementum all collagen fibrils were stained, while collagen fibrils of dentin and cementum were unstained except for some fibrils of minor special areas such as Owen's contour lines, interglobular dentin, Tomes's granular layer, and in cementum small “interglobular‐like” areas. It is concluded that silver methenamine visualizes collagen fibrils of hypo‐ and unmineralized areas in dental hard tissues and therefore may be used to demonstrate abnormal patterns of mineralization. Finally variations of silver methenamine stainability in relation to differences in material and methods were studied and discussed.
Purification of a protein component in extracts from supragingival dental calculus
Authors: EGGEN K. H. , RÖLLA G. 
Published: October 2007

Abstract –In the present study supragingival dental calculus of unknown age was collected from the mandibular incisors of three individuals and solubilized by EDTA. The extracts were examined by gel filtration, ionic exchange chrornatography and amino acid analysis. A protein component with similar characteristics to the main protein component of the acquired enamel pellicle was a regular constituent of the calculus extracts from the three subjects.
Dental erosions in relation to lactovegetarian diet
Authors: LINKOSALO EEVA , MARKKANEN HELENA 
Published: October 2007

Abstract –The subjects of this study were 26 lac to vegetarians and their age‐ and sex‐matched controls. Clinical and radiologic examinations were made and samples of wax‐stimulated whole saliva were collected. Dental erosions were recorded and documented with photographs and plaster models. Incipient, moderate and grave erosive defects were observed in 26.9%, 19.2% and 30.8% of the lactovegetarians, respectively. In controls, however, no erosions were observed. When tested by multiple linear regression analysis, the main factors affecting dental erosions were the rate of flow of saliva., and consumption of vinegar and vinegar conserves, citrus fruits and acidic berries.
Fluoride release from a fluoride‐containing amalgam in vivo
Authors: SKARTVEIT LIV , TVEIT ANNE BJÖRG , EKSTRAND JAN 
Published: October 2007

Abstract –Six test subjects using a low fluoride diet collected saliva samples each morning for 1 wk to determine the normal fluoride concentration. During the following 8 wk an acrylic plate, containing amalgam “fillings” corresponding to 6 MOD amalgams in premolars, was worn each night. Saliva samples were collected every morning and analyzed with a fluoride‐ion electrode. Normal fluoride values ranged from 1.22 μM to 0.57 μM. The first days after insertion of the plates the fluoride concentration ranged from 91.06 μM to 12.26 μM in the subjects. The following 25—30 days there was an exponential decline of the fluoride concentration in saliva with a half‐life of 6 to 7 days. The fluoride level was significantly higher (P < 0.01) than basal levels in all subjects during this period. The following 20–25 days the fluoride level decreased more slowly, approaching the basal level. One subject had a significantly higher fluoride level for all 8 wk. Since the saliva fluoride concentrations registered seem to be sufficient to enhance remineralization, it is concluded that restorations with this material may have a favorable effect not only on secondary caries, but on any initial demineralization in the mouth.
Effectiveness of Veadent as a plaque‐inhibiting mouthwash
Authors: ABBAS DHIA K. , THRANE PER , OTHMAN SALAH J. 
Published: October 2007

Abstract –The aim of this study was to compare the effect of the commercially available Veadent mouthwash and chlorhexidine on plaque formation. Plaque accumulating during two 5‐day periods was recorded in a group of 10 students. During the experimental periods, the test subjects abstained from mechanical cleaning of the teeth, and chewed sucrose‐containing chewing gum every 4th h in order to enhance plaque formation. They also rinsed with either chlorhexidine or Veadent twice a day according to the manufacturer's recommendations. Chlorhexidine mouthrinses resulted in significantly lower plaque scores than did Veadent in the present short‐term model study.
Changes in composition of whole saliva in patients with fissured tongue
Authors: KULLAA‐MIKKONEN ARJA , TENOVUO JORMA , SORVARI TAPANI 
Published: October 2007

Abstract –Both resting and paraffin‐stimulated whole saliva were studied in 25 patients with fissured tongue and in their age and sex‐matched healthy controls. The groups did not differ in dental or periodontal health. No significant differences were found between the groups in the salivary secretion rate, pH and buffer capacity, or in the frequency of lactobacilli and yeasts in saliva samples and scrapings from tongue surface. In patients with fissured tongue, unstimulated whole saliva displayed significantly elevated levels of sodium, lysozyme, myeloperoxidase and all immunoglobulins (isotypes A, G and M) when compared with the controls. These changes most likely reflect the inflammation frequently seen in the biopsies of fissured tongue. No differences between the groups existed in the amounts of salivary potassium, calcium, inorganic phosphate, amylase and total protein. Our study shows that in patients with fissured tongue the salivary secretion and composition are normal. However, components from plasma and inflammatory cells are diagnostically elevated in the whole saliva samples of patients with fissured tongue when compared with the healthy controls.
Electron microscopic and histochemical studies on dystrophic masseter muscle
Authors: MIKKELSEN HANNE , KIRKEBY SVEND 
Published: October 2007

Abstract –Masseter muscles from normal and dystrophic mice were investigated with the electron microscope and by the use of histochemical techniques for myosin ATPase and succinic dehydrogenase activity. The observations show that the muscle fibers arc severely affected in the masseter of the dystrophic mouse.
Scanning electron microscopic study of surface of human oral mucosa
Authors: KULLAA‐MIKKONEN ARJA 
Published: October 2007

Abstract –The surface ultrastructure of the healthy oral mucosa of humans was studied using SEM as follows: dorsum of the tongue (10 specimens), buccal mucosa (5), floor of the mouth (3), hard palate (5), and gingiva (10). One part of each formalin‐fixed sample was processed routinely using the system of critical point drying for scanning electron microscopy. The other part of the specimen was embedded in paraffin blocks and stained with hematoxylin‐eosin for light microscopy. With SEM at low magnification, the surface structure of the oral mucosa at different areas of the oral cavity was smooth with some desquamating cells. Only the tongue mucosa with its papillae formed a specialized mucosa. The hairs of the filiform papillae were covered by microorganisms, whereas on the oral mucosa there usually was little or no colonization by microorganisms. At high magnification, the surface structure of the superficial epithelial cells was pitted or microplicated. On keratinized epithelium the surface structure was pitted, whereas on non‐keratinized epithelium it was microplicated. On cell boundaries some variation could also be seen; in keratinized epithelium these boundaries were overlapping and in non‐keratinized epithelium they were tight.
Aspects of mastication with bridges on osseointegrated implants
Authors: JEMT TORSTEN , CARLSSON GUNNAR E. 
Published: October 2007

Abstract –Sixteen edentulous patients were examined before and 2 months after rehabilitation with fixed bridges supported by fixtures in the mandible. Data were collected regarding bite force, chewing efficiency, chewing movements and self‐estimated chewing ability. The results after rehabilitation indicated that patients with an obvious improvement of chewing efficiency showed a greater increase of the mean bite force parameters than patients with unchanged chewing efficiency. However, it was not possible to find any definite pattern of differences between the groups of patients, based on the chewing efficiency index after rehabilitation. Furthermore, after rehabilitation the test group revealed a positive correlation between the duration of the occlusion phase and bite force values, negative correlations between bite force “as when chewing” and closing velocity and between duration of the occlusion phase and opening mandibular velocity and displacement, respectively.
Clinical assessment of a fluoride‐containing amalgam
Authors: SKARTVEIT LIV , TVEIT ANNE BJÖRG , MJÖR IVAR A. , AAS HILDE TOMBRE 
Published: October 2007

Abstract –The aim of this study was to compare the marginal breakdown as a measure of clinical behavior of fillings made with two conventional amalgam alloys, one of which contained 1% stannous fluoride. Children requiring class II restorations in both mandibular molars received conventional amalgam (New True Dentalloy (R)) in one molar and a fluoride‐containing amalgam (Fluor Alloy (R)) in the other. Impressions of the filled teeth were taken just after polishing and at 1‐yr intervals up to a 2‐yr period. Plastic models were made and evaluated under a stereomicroscope. The results showed that the fluoride‐containing amalgam presented slightly better margins than the conventional amalgam after 2 yr.
Non‐restraining factors affecting setting expansion of phosphate‐bonded investments
Authors: JÖRGENSEN KNUD DREYER , OKAMOTO AKIRA 
Published: October 2007

Abstract –Only a few studies on the setting expansion of phosphate‐bonded investments have been published. In the present work the effect on the non‐restrained setting expansion of mixing time, mixing liquid, mixing device, and volume mixed was investigated for selected brands of this type of investment. It was found that all variables studied may greatly affect the setting expansion, and that the use of the special liquid delivered by the manufacturers in most cases causes an unacceptably high expansion. A modification of the brands studied appears necessary before they can be employed in a precision‐requiring technique.
Triboelectric Charge, Electrophysical Properties and ElectricalBeneficiation Potential of Chemically Treated Feldspar, Quartz and Wollastonite
Authors: Manouchehri H. R. , Hanumantha Rao K. , Forssberg K. S. E. 
Published: October 2007

The triboelectric charge attributes of the pure feldspar, quartz and wollastonite mineral
samples, after contact with plate and cyclone type tribochargers made up of different
materials were investigated. The main electrical properties of the minerals, i.e., electrical
conductivity and dielectric constant, were measured and their energetic work functions
were estimated. In addition, the behaviour of mineral samples in the electric field of a
free‐fall separator before and after chemical treatment with different organic reagents
was deduced.The results reveal that the cyclone tribochargers are more effective in imparting
charges on mineral grains. The reproducible charges with higher magnitudes are created
when cyclones are used for imparting charges on mineral grains. Furthermore, in spite of
having relatively similar energetic structures for the three minerals, the Teflon tribocharger
demonstrates the feasibility of quartz separation from wollastonite and feldspar.
The salicylic acid conditioning promotes feldspar‐wollastonite separation.
Fetal Microchimerism in Women with Breast Cancer
Authors: Gadi Vijayakrishna K. , Nelson J. Lee 
Published: October 2007

Abstract
Fetal microchimerism (FMc) describes long-term persistence of small numbers of fetal-derived allogeneic cells in the mother. Although FMc has been implicated as a mechanism of autoimmune disease, it may confer a beneficial effect with immune surveillance of malignant cells. We hypothesized that allogeneic FMc imparts a protective effect against breast cancer. Two observations provided a rationale for the study hypothesis. First, allogeneic cells convey risk reduction for recurrent malignancy in hematopoietic cell transplantation. Second, reduced risk of breast cancer is well recognized among parous compared with nulliparous women. As an initial test of the hypothesis, we investigated 82 women, 35 with breast cancer and 47 who were healthy, for male DNA in peripheral blood, presumed from a prior pregnancy with a male fetus. The prevalence and levels of male DNA were determined by real-time quantitative PCR for the Y chromosome–specific gene DYS14 in DNA extracted from peripheral blood mononuclear cells. FMc was found significantly more often in healthy women than women with breast cancer (43% versus 14%, respectively). Considering the absence of FMc as a risk factor, the odds ratio was 4.4 [95% confidence intervals (95% CI), 1.34–16.99; P = 0.006]. Restricting analysis to women known to had given birth to a son, the odds ratio was 5.9 (95% CI, 1.26–6.69; P = 0.01). Our findings indicate that allogeneic FMc may contribute to reduction in risk of breast cancer. Further studies are indicated and, if confirmed, extended studies to examine whether allogeneic immune surveillance from FMc is deficient in women with breast cancer. [Cancer Res 2007;67(19):9035–8]
Cell Division Cycle 25B Phosphatase Is Essential for Benzo(a)Pyrene-7,8-Diol-9,10-Epoxide–Induced Neoplastic Transformation
Authors: Srivastava Sanjay K. , Bansal Pallavi , Oguri Tetsuya , Lazo John S. , Singh Shivendra V. 
Published: October 2007

Abstract
Cell division cycle 25B (Cdc25B) phosphatase controls entry into mitosis and regulates recovery from G2-M checkpoint-induced arrest. In the present study, we show that exposure of diploid mouse embryonic fibroblasts (MEF) to the ultimate carcinogen anti-benzo(a)pyrene (BP)-7,8-diol-9,10-epoxide (anti-BPDE) resulted in a concentration- and time-dependent increase in Cdc25B protein levels. Chronic exposure of wild-type (Cdc25B+/+) MEFs to anti-BPDE (0.1 μmol/L) caused neoplastic transformation characterized by colony formation in culture and tumor production in nude mice. In contrast, the Cdc25B null MEFs were resistant to anti-BPDE–induced transformation. Furthermore, a carcinogenic dose of the parent hydrocarbon (BP) increased Cdc25B protein levels in the target organ, lung. The biological importance of elevated Cdc25B levels was documented by the early reentry into mitosis of cells overexpressing ectopic Cdc25B levels even in the presence of DNA damage following anti-BPDE exposure, whereas control cells resumed only after DNA damage was repaired. We conclude that Cdc25B has an essential role in anti-BPDE–induced neoplastic transformation, including regulation of cell cycle resumption in the presence of DNA damage. [Cancer Res 2007;67(19):9150–7]
Reduced Body Size and Decreased Intestinal Tumor Rates in HDAC2-Mutant Mice
Authors: Zimmermann Stephan , Kiefer Franz , Prudenziati Michela , Spiller Carmen , Hansen Jens , Floss Thomas , Wurst Wolfgang , Minucci Saverio , Göttlicher Martin 
Published: October 2007

Abstract
Histone deacetylases (HDAC) reverse the acetylation of histone and nonhistone proteins and thereby modulate chromatin structure and function of nonhistone proteins. Many tumor cell lines and experimental tumors respond to HDAC inhibition. To assess the role of an individual HDAC isoenzyme in physiology and tumor development, HDAC2-mutant mice were generated from a gene trap embryonic stem cell clone. These mice express a catalytically inactive fusion protein of the NH2-terminal part of HDAC2 and β-galactosidase, which fails to integrate into corepressor complexes with mSin3B. They are the first class 1 HDAC mutant mice that are viable although they are ∼25% smaller than their littermates. Cell number and thickness of intestinal mucosa are reduced. Mutant embryonic fibroblasts fail to respond to insulin-like growth factor I (IGF) by the IGF-I–induced increase in cell number observed in wild-type cells. These data suggest a novel link between HDACs and IGF-I–dependent responses. Crossing of HDAC2-mutant with tumor-prone APCmin mice revealed tumor rates that are lower in HDAC2-deficient mice by 10% to 100% depending on segment of the gut and sex of the mice. These mice provide evidence that the key functions of HDAC2, although not essential for survival of the organism, play a rate-limiting role for tumor development in vivo. [Cancer Res 2007;67(19):9047–54]
Class III β-Tubulin Mediates Sensitivity to Chemotherapeutic Drugs in Non–Small Cell Lung Cancer
Authors: Gan Pei Pei , Pasquier Eddy , Kavallaris Maria 
Published: October 2007

AbstractFirst line therapy for non–small cell lung carcinoma (NSCLC) commonly includes combination therapy with a tubulin-binding agent (TBA) and a DNA-damaging agent. TBAs suppress microtubule dynamics by binding to the β-tubulin subunit of α/β-tubulin, inducing mitotic arrest and apoptosis. Up-regulation of class III β-tubulin (βIII-tubulin) has been implicated in clinical resistance in NSCLC, ovarian and breast tumors treated in combination with a TBA and DNA-damaging agent. To investigate the functional significance of βIII-tubulin in resistance to both these classes of agents, small interfering RNA (siRNA) was used to silence the expression of this isotype in two NSCLC cell lines, NCI-H460 and Calu-6. Reverse transcription-PCR and immunoblotting showed that βIII-siRNA potently inhibited the expression of βIII-tubulin, without affecting the expression of other major β-tubulin isotypes. Clonogenic assays showed that βIII-siRNA cells were significantly more sensitive to TBAs, paclitaxel, vincristine, and vinorelbine, and for the first time, DNA-damaging agents, cisplatin, doxorubicin, and etoposide compared with controls. Cell cycle analysis of H460 βIII-siRNA cells showed reduced accumulation at the G2-M boundary and an increase in the sub-G1 population in response to TBA treatment compared with control cells. Importantly, βIII-siRNA cells displayed a significant dose-dependent increase in Annexin V staining when treated with either paclitaxel or cisplatin, compared with controls. These findings have revealed a novel role for βIII-tubulin in mediating response to both TBA and DNA-damaging agent therapy and may have important implications for improving the targeting and treatment of drug-refractory NSCLC. [Cancer Res 2007;67(19):9356–63]