bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracture Toughness of Dentin/Resin-composite Adhesive Interfaces
Authors: Tam L.E. , Pilliar R.M.
Published: November 2010

The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/ resin-composite bonded interfaces.

The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37°C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p < 0.05) between the dental adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2.

Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.
Salivary Yeasts, Saliva, and Oral Mucosa in the Elderly
Authors: Narhi T.O. , Ainamo A. , Meurman J.H.
Published: November 2010

Yeasts are commensals in the oral cavity and may not cause disease unless there are predisposing host factors, such as other disease, or when medication is being taken. The elderly are at increased risk of yeast infection. In this paper, prevalence of salivary yeasts in a group of 368 inhabitants of Helsinki aged 76, 81, and 86 years is reported. Salivary yeasts were counted by the Oricult-N® dip-slide method, salivary secretion rate and buffering capacity were measured, type of dentition was noted, and signs of yeast infection and the occurrence of subjective symptoms were determined.

There was no growth of yeasts in 25% of the subjects. From one to 20 colonies/slide were observed in 21%, 21-50 colonies in 21%, and over 50 colonies (a high count) in 33%. Subjects with low salivary flow rates and low buffering capacities had significantly higher yeast counts than did subjects with normal salivary flow rates and buffering capacities. High yeast counts were found in 19% of subjects with natural teeth. The corresponding percentages in those wearing partial or complete dentures were 32 and 41, respectively. High salivary yeast counts were associated with oral mucosal lesions but not with subjective complaints of oral symptoms.
Transformation Efficiency of EMS-induced Mutants of Streptococcus mutans of Altered Cell Shape
Authors: Tao L. , MacAlister T.J. , Tanzer J.M.
Published: November 2010

Some Streptococcus mutans strains change shape from bacillary to coccal or ellipsoid form in response to the ratio of bicarbonate to potassium or of borate to potassium in growth media. So that insight into determinants of shape of these streptococci could be gained, and future genetic studies facilitated, the shapes of a series of transformable and nontransformable strains of S. mutans were studied and attempts made to isolate a mutant of augmented transformability. Several strains were mutagenized by ethylmethane sulfonate and mutants with altered colonial and cellular morphologies isolated. Cell shapes were studied by Gram stain and Nomarski interference microscopy, and by scanning and transmission electron microscopy. Diverse shape-altered mutants were isolated from seven transformable and two nontransformable strains of S. mutans. Among these, length-to-width ratios ranged from >10 to about 0.25. Regulation of timing of cell division, septum formation, or septum completion events may have been altered in these mutants. While most mutants substantially or completely lost transformability, mutant LT11 had transformation efficiency of 1.3 x 10-4 to 2.3 x 10-3, more than two to three orders of magnitude greater than its parental UA159 and the well-known transformable strain GS5(HK), respectively. There was no evidence of production of competence factor by LT11. Competence of LT11 was maintained for at least six months upon storage at -70°C, facilitating its use for genetic studies. While the morphologies of several shape-altered mutants were no longer responsive to changes of the bicarbonate/potassium, unlike those oftheir parentals, the morphology of LT11 persisted in its response to this condition. The transformation proficiency of LT11 makes it highly useful for genetic studies of S. mutans.
Closest Speaking Space During the Production of Sibilant Sounds and its Value in Establishing the Vertical Dimension of Occlusion
Authors: Burnett C.A. , Clifford T.J.
Published: November 2010

The purpose of this investigation was to determine whether the production of sibilant sounds involved adopting a jaw position that corresponded to the closest vertical speaking space (CSS), by analysis of the smallest vertical excursion of the mandible during the performance of different phonetic exercises. A further objective was to establish the variability in the-CSS produced by individual sibilant phonemes. Thirty young adult subjects had their CSS determined during three separate phonetic tests, using a kinesiograph (Sirognathograph, Siemens A.G., Benshiem, Germany) and a Bio-Pak (BioResearch Associates Inc., Milwaukee, WI) jaw-tracking software program. The first test was a general phonetic articulation test containing all the sounds of the English language and specifically including all six sibilant word sounds. The second phonetic test contained the six sibilant sounds making up a short sentence. The third test included six single words, each expressing a different sibilant sound. No statistically significant difference among the mean CSS determined in each of the three exercises was demonstrable. A phonetic test containing all sibilant sounds produced a CSS equivalent to that of a test containing all speech sounds. The vertical component of the CSS was also independent of the form or duration of the phonetic tests containing the sibilant word sounds used in this investigation. The CSS determined for 5 of the individual sibilant phonemes in the third exercise differed (p < 0.05) from that calculated for the three complete exercises. It was concluded that voicing sibilant phonemes, or word sounds, does cause the subject to adopt the CSS. When a phonetic test is used in the determination of the vertical dimension of occlusion, one of short duration containing all the sibilant sounds appears to give a reliable guide to the CSS. It was also concluded that subjects varied with respect to which of the group of sibilant sounds produced the CSS, and that a single sibilant word sound does not give a reliable indication of the smallest speaking vertical dimension.
Recovery of the Jaw-opening Reflex after Lesions of the Lingual Nerve in the Rat
Authors: Radwan Y. , Thexton A.J.
Published: November 2010

In three groups of rats, lesions were produced in the right lingual nerves near the base of the tongue; the three types of injury inflicted (cryogenic, crush, and stretch) are reputed to spare the epineurium but produce different degrees of intraneural damage. In regular assessments of recovery, an electrical stimulus (sufficient to elicit the jaw-opening reflex) was applied to either side of the tongue in turn; the amplitude of the reflex was measured as the isometric force of jaw opening. The size of the reflex response to stimulation of the injured side was followed up to 4 months post-lesion, with the response elicited from the control side used as the reference level. The reflex was absent when the experimental side was stimulated immediately after creation of a lesion; the first sign of reflex recovery was found at about 15 days post-operative. Subsequently, in 84% of the animals, the reflex activity elicited from the experimental side increased until it exceeded that elicited from the reference side; this relative hyperreflexia started 1-4 months post-lesion and had a highly variable duration. There was no difference in the incidence, latency, or duration of the hyperreflexia following any of the three types of lesion. The hyperreflexia found in this study is not readily explained by existing hypotheses of the mechanisms underlying post-lesion hyperesthesia or central neuronal hyperexcitability.
The Reinnervation of Healing Extraction Sockets in the Ferret
Authors: Mason A.G. , Holland G.R.
Published: November 2010

The objective of this study was to describe the pattern of healing of pulpal and periodontal nerve fibers following tooth extraction. The mandibular canine teeth were, under general anesthesia, removed from one side of nine young ferrets. One week (two animals), one month (four animals), and three months (three animals) later, again under general anesthesia, the animals were perfused with fixative. The mandibles were decalcified, paraffin-embedded, and serially sectioned. Sample sections were stained with hematoxylin and eosin, the remainder with a silver stain for nerves. Serial reconstructions were made of the innervation in control teeth and in the extraction sockets. A grid sampling technique was used for the estimation of the innervation density in different regions at various levels in the healing socket. One week after extraction, although osteoid material was beginning to fill the socket, the pattern of innervation remained similar to that of controls in being restricted to the former location of the periodontal ligament and being densest in the apical third of the socket. One month after extraction, the innervation consisted of many fine axons or small bundles distributed throughout the healing osteoid tissue though still most dense in the periphery of the socket. The overall innervation density increased between one week and one month post-extraction. At three months, as the margins of the socket were becoming obscured, the innervation consisted largely of one or two organized nerve trunks running from the apical to the coronal aspect in either the central or lateral aspects of the socket. At no time was there evidence of neuroma formation.
Crystallographic Morphology of Heterogeneous Fluoridated Carbonate Apatites
Authors: Okazaki M.
Published: November 2010

Carbonate-containing fluoridated apatites were synthesized with two different modes of fluoride incorporation: by supplying F-free solution initially, followed by a F-containing solution; and with the order of supply of these solutions reversed. Both of these heterogeneously synthesized fluoridated CO3 apatites showed typical apatitic x-ray diffraction patterns; and both had similar total fluoride contents (0.87 ± 0.07 and 0.94 ± 0.03 mmol/g, respectively), i.e.. half of the maximum fluoride content of fluorapatite. However, they differed considerably in their crystallographic properties. The 300 reflection peaks of both apatites were split, and their patterns were slightly different. In the former, SEM observation revealed capsule-like crystals with a rounded hexagonal shape. However, the latter had many small crystals, similar to those of homogeneous CO3 apatite, adhering to the larger hexagonal crystals, which were also similar to homogeneous fluorCO3apatite. Wavelength-dispersive spectroscopy attached to the SEM showed a higher fluoride intensity in the former spectrum than the latter. These results suggest that two different types of heterogeneous fluoridated CO3 apatites were formed, CO 3 apatite covered with fluorCO3apatite, and fluorCO 3apatite covered with CO3 apatite. The simple two-step supply system used in this study is helpful for the study of complicated heterogeneous formation of apatites.
The Level of Mercury in Human Dental Plaque and Interaction in vitro between Biofilms of Streptococcus mutans and Dental Amalgam
Authors: Lyttle H.A. , Bowden G.H.
Published: November 2010

Mercury levels (ug/mg dry weight) in dental plaque from amalgam and enamel surfaces in human subjects with amalgam restorations were (range, mean, SD) 0.5-1.31, 0.72,0.34 and 0.01-0.54, 0.2, 0.19, respectively. The levels of mercury in plaque from amalgam surfaces were significantly higher than those from plaque on enamel (p < 0.001). No mercury was detected in plaque from subjects without amalgam restorations. The mean level of mercury in a 24-hour collection of plaque was 2 pg (median, 1.8 ug), an amount close to those calculated by other workers (1.2-1.7 pg) for the amount of mercury liberated in the mouth from amalgam restorations in 24 h. Freshly prepared amalgam liberated relatively large amounts of mercury into culture broth in the first 24 h of exposure; subsequently, the levels declined except in the presence of Streptococcus mutans. In vitro, biofilms of Streptococcus mutans facilitated the release of mercury from freshly prepared amalgam, in what appeared to be a cyclical fashion. Amalgam aged for two years did not release mercury, even when supporting the growth of an S. mutans biofilm. The resistance of aged amalgam was attributed to the presence of a passive tarnish layer. The mercury released by the biofilm had an effect on the composition of the biofilm. The biofilms on fresh amalgam had significantly lower levels of carbohydrate (p < 0.001- p < 0.01) and protein (p < 0.001 - p < 0.02) than did biofilms on aged amalgam and on control stainless steel wires.
Immunohistochemical Studies on the Distributions and Age-related Changes of Types I and III Collagen in the Oral Mucosa of Mice
Authors: Xu L.X. , Ohsaki Y. , Nagata K. , Kurisu K.
Published: November 2010

The distribution of types I and III collagen in mouse oral mucosa and the age-related changes over 3 days to 2 years of age were examined by immuno-fluorescence and -electron microscopy, with use of affinity-purified polyclonal antibodies. Immunofluorescence microscopy revealed that types I and III collagen existed in all tissues and at all ages examined. The staining intensity for type I collagen was stronger and increased more markedly in the lamina propria of the hard palate (HPlp) and gingiva (G), compared with that in the submucosa of the hard palate (HPsm) and the buccal mucosa (BM). The staining intensity for type III collagen was strong and increased markedly with age in all connective tissues examined. Examination of immunogold-labeled tissues demonstrated that most of the collagen fibrils were labeled for both type I and type III collagen, which suggests that they were hybrid fibrils containing both types of collagen. The quantitative evaluation of the labeling densities of gold particles revealed that the labeling density of type III collagen in BM and HPsm was higher and increased more rapidly during growth than in HPIp and G, while the labeling density of type I collagen was higher in HPIp and G. The fibril diameters in HPIp were larger and increased more rapidly during growth than in BM and HPsm. These studies are the first to demonstrate the distribution of types I and III collagen and their age-related changes in mouse oral mucosa. The results support previous suggestions that type I collagen may contribute to the stability of the connective tissue organization and that type III collagen may play an important role in the flexibility of the connective tissue of oral mucosa as well as in the regulation of the collagen fibril diameters in the tissue.
Antigenic Relationships among Oral Actinomyces Isolates, Actinomyces naeslundii genospecies 1 and 2, Actinomyces howellii, Actinomyces denticolens, and Actinomyces slackii
Authors: Putnins E.E. , Bowden G.H.
Published: November 2010

Antigenic relatedness among human strains of oral Actinomyces and similar isolates from cattle has been analyzed by agglutination and immunoblotting. Whole cell agglutination placed A. viscosus serotype II, A. naeslundii serotypes II and III, Actinomyces NV, and strains from numerical taxomonic clusters C1, C2, C3, C4, and C6 into a single group. A. viscosus serotype I cross-reacted weakly with this group. A. naeslundii serotype I strains and the cattle isolates Actinomyces denticolens and Actinomyces howellii were distinct. The agglutination results for A. slackii were equivocal. Immunoblots of cell wall extracts developed with non-absorbed sera showed cross-reactivity (23% to 90% antigenic similarity) among all of the strains tested, including A. israelii. The range of antigenic similarities among the group which included strains of A. viscosus serotype II, the A. naeslundii serotypes, and clusters C1, C2, C3, C4, and C6 was from 39% to 89%. Immunoblotting showed that A. howellii and A. denticolens were between 39% and 72% similar to A. naeslundii and A. viscosus. Absorption of antisera with A. israelii cell walls removed antibodies recognizing antigens common to Actinomyces and made the sera more specific. Immunoblotting with absorbed sera supported the grouping and separation of strains shown by agglutination. In some cases, serotypes could be included into a specific taxonomic cluster. A. naeslundii serotype II and Actinomyces NV most closely resembled cluster C1 strains, and A. naeslundii serotype III resembled cluster C3 strains. A. naeslundii serotype I and A. viscosus serotype I were included into clusters C5 and C7, respectively. The results support a recent proposal that strains of A. viscosus serotype II, A. naeslundii serotypes II and III, and Actinomyces NV be included into A. naeslundii genospecies 2, that A. naeslundii serotype I should be designated A. naeslundii genospecies 1, and that A. viscosus serotype I should be retained distinct from A. naeslundii, as A. viscosus.
An in vitro Simulation of the Effects of Chewing Sugar-free and Sugar-containing Chewing Gums on pH Changes in Dental Plaque
Authors: Macpherson L.M.D. , Dawes C.
Published: November 2010

The objective of these studies was to simulate the effect of chewing sugar-free and sucrose-containing chewing gums on the return of the pH to neutrality after exposure to sucrose of plaque located on the buccal (BLM) and lingual (LLM) surfaces of the lower molar teeth. In study 1, a 0.5-mm-deep artificial plaque containing Streptococcus oralis cells was exposed to 10% sucrose for one min, and a 0.1-mm-thick film of sucrose-free artificial saliva was then flowed over the plaque surface at the unstimulated salivary film velocities previously found at the BLM and LLM sites. At the time of the pH minimum (pH 4-5), one of three conditions was simulated: (a) a no-gum-chewing control, or chewing for 20 min on either (b) a sugar-free gum or (c) a sucrose-containing gum. The recovery of the plaque pH to resting values was rapid during simulation of chewing a sugar-free gum (SFG), much slower with the no-gum control, and even slower with simulation of chewing a sucrose-containing gum (SCG). The pH recovery was slower with the BLM than the LLM plaque. In study 2, the BLM plaque was exposed to a 2% sucrose solution for 20 min under stimulated salivary conditions, to simulate the consumption of a meal, followed by one of conditions (a), (b), or (c) described above. The pH recovery with simulation of chewing a SCG was faster than with the no-gum control, but much slower than with the SFG simulation. In study 3, when both BLM and LLM plaques were exposed for 20 min to the sucrose levels in chewing-gum-stimulated saliva and then unstimulated conditions were simulated, the pH fall and recovery were similar to those found by others in vivo. From the results of these studies, it would be expected that when the plaque pH has fallen, after exposure to fermentable carbohydrate, it would return to neutrality more readily with the use of sugar-free rather than sucrose-containing gums.
Effects of CO2 Laser Irradiation in vivo on Rat Alveolar Bone and Incisor Enamel, Dentin, and Pulp
Authors: McKee M.D.
Published: November 2010

Previous studies have shown that a surgical 'window' can be drilled in alveolar bone for experimental manipulation of the underlying enamel organ and enamel. To determine whether similar and/or improved access could be obtained by use of the surgical capabilities of laser optics, and to note the effects of laser irradiation in vivo on the extracellular matrices and cells of bone, enamel, and dentin, tissue responses to laser-created lesions were examined histologically. Briefly, samples were prepared in which the alveolar bone along the inferior mandibular border of Wistar rats was exposed, and a continuous-wave CO2 laser equipped with a custom-made micromanipulator was used to penetrate the bone and to create lesions within the lower incisor. Animals were perfusion-fixed at either 10 min or 10 days post-treatment, and affected tissues were processed for light and transmission electron microscopy. At 10 min, all lesions consisted of a void of ablated tissue containing some organic debris. Tissues immediately surrounding the lesion were generally intact, but showed some damage, presumably resulting from elevated temperature effects. At 10 days, lesions in the bone, dentin, odontoblast layer, or pulp showed morphological evidence of tissue repair represented by the presence of cell infiltrates, new bone, or reparative dentin. In lesions that were created during the secretory stage of amelogenesis that had moved into the maturatiori stage, there was evidence of delayed or incomplete maturation of enamel ( i.e., retention of organic matrix normally lost during maturation) related to the enamel organ affected by the laser treatment. In the bone lesion at 10 days, new bone formation was observed, while bone fragments originally created at the time of lasing were surrounded by mononuclear and large multinucleated giant cells. It is thus concluded that the application of this laser system is an alternative method for exposing unerupted dental tissues for experimental manipulation, and that laser irradiation may also be useful for the study of mineralized tissue repair.
Diagnostic Value of Orthopedic Tests in Patients with Temporomandibular Disorders
Authors: Lobbezoo-Scholte A.M. , Steenks M.H. , Faber J.A.J. , Bosman F.
Published: November 2010

For a better definition of diagnostic subgroups of patients with temporomandibular disorders (TMD), clinical orthopedic tests have been developed for the masticatory system, for use together with the commonly used active movement tests and palpation. In the present study, the characteristics and additional diagnostic value of four orthopedic tests-namely, passive opening, the joint play test, compression, and the static pain test-were determined for a patient group, diagnostic subgroups, and a control group. Significant differences among the scores of the tests in the different groups indicated that all six orthopedic tests contributed to the diagnostic process. Because of the close functional relationship of the masticatory system, most information was obtained when patients indicated where pain occurred during the different tests.

Logistic regression techniques were used for determination of the relative diagnostic value of each orthopedic test in the diagnostic process. Active movement was the most powerful test for distinguishing the different subgroups. Palpation and passive opening were additionally useful for distinguishing between patients and control subjects and between the subgroups of arthrogenous and myogenous patients. Besides active movement, both compression and the joint play test played a minor role in the distinction of subgroups of arthrogenous patients. It may be concluded that in routine clinical practice, besides history taking and conventional radiography, a functional examination consisting of active movements, passive opening, and palpation provides valuable diagnostic information. In patients with a specific diagnostic problem, one of the other additional tests might be indicated.
A Chondroitin Sulfate Epitope in Mammalian Dental Pulp and its Developmental Expression in Mouse Dental Papilla
Authors: Nieminen P. , Vainio S. , Jernvall J. , Lukinmaa P.-L. , Lehtonen E. , Thesleff I.
Published: November 2010

The molecular specificity of the dental papilla of a bell-stage tooth was studied by production of dental-papilla-reactive monoclonal antibodies (Mabs). One of the Mabs, designated 7C5, recognized an epitope present in glycosaminoglycan. Several lines of evidence suggested that the 7C5-epitope consists of chondroitin 6-sulfate. The Mab did not react with mouse dental epithelium, but reacted uniformly with mesenchymal tissue in the mandibular process and accumulated in the dental sac and in the papilla of bell-stage tooth germs. The 7C5-staining was lost from the differentiating odontoblasts, while the staining in the molar tooth papilla was accumulated in the subodontoblastic layer. In the developing mouse incisor, the 7C5-epitope was restricted to the lingual-posterior area. The 7C5-epitope was also present in pulpal tissue and predentin of different types of teeth of various mammalian species, including man, sheep, swine, and rat. Collagenase pre-treatment of tissue sections abolished the bulk of the 7C5-reactivity in peridental mesenchyme during embryonic stages while leaving the staining of the dental papilla intact. In newborn and adult teeth, collagenase also impaired the reactivity in the pulp except for the subodontoblastic layer. This suggests the existence of different subpopulations of the 7C5-epitope containing proteoglycans in dental papilla and pulp. A high-molecular-weight proteoglycan, sensitive to chondroitinase ABC but not to heparinase or heparitinase, was immunoprecipitated by 7C5 from extracts of bell-stage mouse tooth germs. We suggest that the evolutionary conservation of chondroitin 6-sulfate in the dental pulp reflects its properties as non-terminally differentiated tissue and perhaps the retention of a potential to differentiate to odontoblasts.
The Effects of Enamel Anisotropy on the Distribution of Stress in a Tooth
Authors: Spears I.R. , Van Noort R. , Crompton R.H. , Cardew G.E. , Howard I.C.
Published: November 2010

Enamel is thought to have highly anisotropic stiffness characteristics, because of its prismatic structure. It is probable that the enamel is stiffer in the prism direction compared with a direction perpendicular to it. The prisms are thought to run approximately perpendicular to the enamel-dentin junction. The curvilinear anisotropy that will result can readily be modeled by TOMECH, a finite element program developed at the University of Sheffield, since curvilinearity of mechanical properties is available as an automated feature of this program. The patterns of stress due to an external load were investigated in two-dimensional abstract models, and in a model of a mandibular second premolar, for both anisotropic and isotropic enamel. Results were compared with the commercial code ANSYS and good agreement obtained. Enamel with anisotropic properties was found to have a profoundly different stress distribution under load when compared with models with isotropic enamel. For isotropic enamel, the load path is directed through the stiff enamel shell, while for anisotropic enamel, the load path is directed into the dentin, as the load path follows the stiff direction ofthe enamel prisms. Thus, if enamel is indeed anisotropic, its function differs greatly from that suggested in previous hypotheses. Enamel with anisotropic material characteristics would provide a hard-wearing protective surface-coating while simultaneously diverting the load away from this brittle, low-tensile-strength phase, thus reducing the potential for tooth fracture.
Interferometric Measurements of Cusp Deformation of Teeth Restored with Composites
Authors: Suliman A.A. , Boyer D.B. , Lakes R.S.
Published: November 2010

A Michelson interferometry apparatus was used for measurement of the displacement of the buccal cusps of premolars after restoration of MOD preparations with composites. The effects of composite type, cavity size, and hydration conditions were examined. Interferometry permitted real-time measurement of cusp movement as it occurred. Contraction occurred very rapidly, about 1/3 of the 60-minute amount within the two-minute period of exposure to the curing light. Cusp movement was smooth rather than interrupted, indicating lack of microfracturing at deformations of 11-46 μm. Contraction, 0.94% for Heliomolar and 1.2% for P-50, was similar to the linear polymerization shrinkage of the resins. Less cusp movement occurred in small cavities than in large cavities. Hydrated teeth had less cusp movement than dehydrated teeth.
A Study of Macrophages, Macrophage-related Cells, and Endothelial Adhesion Molecules in Recurrent Aphthous Ulcers in HIV-positive Patients
Authors: Regezi J.A. , Macphail L.A. , Richards D.W. , Greenspan J.S.
Published: November 2010

The purpose of this immunohistochemical study was to investigate the presence and distribution of macrophages (CDllc+ and CD68+) and macrophage-related dendritic cells (factor XIIIa+ and CD36+) in early and late aphthous ulcers associated with HIV infection. To substantiate a mechanism by which these cells may move from the vascular compartment to tissue spaces, we also investigated expression of ELAM (endothelial leukocyte adhesion molecule), ICAM-1 (intercellular adhesion molecule), and CD18 (leukocyte function antigen). Numerous CD 1 lc+ and CD68+ macrophages were seen in early lesions, though larger numbers of CD68+ cells were present in older lesions. No significant increases in factor XIIIa+ dendrocytes were seen in either early or late lesions, though dendrocytes appeared enlarged. CD36+ cells and CD18+ leukocytes were more numerous in early than in late aphthous ulcers. ELAM and ICAM expression was most intense on endothelial cells in early aphthous ulcers, with staining intensity fading toward the lesion periphery. Control specimens showed weaker ELAM and ICAM staining than did the ulcer specimens. Keratinocytes did not express ICAM. By virtue of their numbers, macrophages and macrophage subtypes appear to have a significant role in both the early and late stages of this disease. Although factor XIIIa-expressing dendrocytes may not have been more numerous in the ulcers, they appeared to be "activated" because of their prominence in the lesions and their occasional co-expression of CD68 antigen (KP1+). They may have a minor role in antigen processing, phagocytosis, and fibroplasia. ELAM and ICAM expression by endothelial cells provides a mechanism by which macrophages and other leukocytes can be recruited to the site of the lesion. This mechanism appears to be functional in HIV-positive patients.
A Comparison of Serine and Threonine O-Glycosylation by UDP-GaINAc:Polypeptide N-Acetylgalactosaminyltransferase
Authors: O'Connell B.C. , Tabak L.A.
Published: November 2010

O-glycosylated proteins are ubiquitous in eukaryotes and are responsible for a variety of biological functions. O-glycosylation is initiated by the addition of N-acetylgalactosamine to serine or threonine residues, though it is not clear how specific residues are selected for modification. We have compared serine and threonine glycosylation using peptide substrates based on sequences from erythropoietin (EPO) and von Willebrand factor (HVF) that are glycosylated in vivo. UDP-GaINAc :polypeptide N-acetylgalactosaminyltransferase was derived from rat parotid, submandibular, and sublingual glands, liver and kidney as well as from human colostrum. The threonine-containing substrates were glycosylated to a much greater extent than those containing serine for all the enzyme sources. Changes in reaction pH, donor concentration, or divalent cation were unable to increase glycosylation of serine. When the incubation time was extended, serine in the EPObased peptide was found to incorporate GalNAc at a low level, in contrast to the serine-containing HVF peptide, which did not glycosylate at all. By circular dichroism, the non-glycosylating peptide was the only one of the series that did not exhibit random coil structure. Our data suggest that although the structural and sequence requirements for O-glycosylation of serine and threonine residues are similar, serine sites are glycosylated less effectively than are threonine sites in vitro.
Interaction of the Salivary Glycoprotein EP-GP with the Bacterium Streptococcus salivarius HB
Authors: Schenkels L.C.P.M. , Ligtenberg A.J.M. , Veerman E.C.I. , Van Nieum Amerongen A.
Published: November 2010

The interaction of the human salivary glycoprotein EP-GP with a number of oral bacterial species, following incubation with human whole saliva, has been investigated. EP-GP could be detected with a specific monoclonal antibody, by means of ELISA or by electrophoresis in combination with Western Transfer. The results indicated that EP-GP is bound only by Streptococcus salivarius, and not by the other tested strains of bacteria, Actinomyces viscosus, A. naeslundii, Actinobacillus actinomycetemcomitans, Bacteroides fragilis, S. gordonii, S. oralis, S. sanguis, S. mitis, S. mutans, S. sobrinus, S. rattus, S. constellatus, and S. anginosus. Binding of EP-GP to S. salivarius is mediated by a protein-protein interaction, which was found to be pH-dependent with a maximum binding between pH 5 and 6. For further characterization of the binding of EP-GP to S. salivarius, four mutants were tested, each of them lacking different cell wall antigens. EP-GP was bound to all mutants in amounts comparable with the wildtype, in spite of the different surface antigen compositions. We were able to identify a 27-kD EP-GP binding protein, by extraction of S. salivarius-cell wall antigens and electrophoretic techniques. In addition to EP-GP, S. salivarius also bound two other salivary proteins, namely, secretory IgA and low-molecular-weight mucin (MG-2).
Caries Prevalence in 6- to 15-year-old French Children based on the 1987 and 1991 National Surveys
Authors: Cahen P.M. , Obry-Musset A.M. , Grange D. , Frank R.M.
Published: November 2010

The caries prevalence in a multi-stage probability sample of 18,786 children representative of all French children 6-15 years of age was studied in 1991 and compared with the results of a similar survey made in 1987. A significant decline in dental caries in France became evident. This decline, observed in primary as well as in permanent teeth, was of variable magnitude among the different age groups. At the age of 6, 48.6% of the children were totally caries-free in 1991. At the age of 12, the DMFT and DMFS indices were 2.59 and 4.72, respectively, representing a corresponding decrease of 38% and 37%. In 1991, more caries-affected teeth or surfaces were filled, whereas fewer caries-affected teeth or surfaces were untreated. Females and children living in rural areas had a higher caries prevalence in both surveys. Pit-and-fissure lesions were the predominant caries types. Dental fluorosis was very uncommon; 96.1% of the 18,786 children examined in 1991 were totally free of any such lesions. Average plaque and calculus indices were similar in 1987 and in 1991, but a decrease of 25% was observed in the average gingival indices. Although the relative contributions of various preventive factors to to this caries reduction are not clear, it should be noted that use of fluoridated salt (250 mg/kg KF) started in January, 1987. The sale of fluoridated dentifrices and the use of fluoride tablets and sugar substitutes increased during the period from 1987 to 1991.
A Single-section Model for Enamel De- and Remineralization Studies. 1. The Effects of Different Ca/P Ratios in Remineralization Solutions
Authors: Exterkate R.A.M. , Damen J.J.M. , Ten Cate J.M.
Published: November 2010

A prerequisite for the accurate measurement of differences between pre- and post-experimental mineral profiles in single sections by quantitative microradiography is a high degree of reproducibility of the analytical procedures. We have determined the reproducibility of both the production and analyses of microradiographs. Lesions were made in seven single bovine enamel sections and radiographed three times. Each microradiograph was then analyzed on three different occasions by use of an image analysis system. This resulted in only small standard deviations in the lesion parameters. The method was used to determine the sites of mineral deposition in lesions in single sections during remineralization in three different solutions, one of which contained 1.5 mmol/L Ca and 0.9 mmol/L PO4 (standard solution); the other two solutions were low in either Ca or PO4, but all three had the same degree of supersaturation. The mineral profiles and lesion parameters were determined after lesion formation and after remineralization for 4 days, 1, 2, and 3 weeks. The decrease in IML (integrated mineral loss) in the lesions remineralized in the standard solution was greatest during the first week. Lesion profiles revealed that, under non-standard conditions, mineral deposition was retarded in the deeper part of the lesion, in contrast to the even distribution of mineral deposition from the standard solution. Differences in IML changes and lesion profiles between these bovine enamel experimental groups diminished when remineralization continued for 2 and 3 weeks. Possibly, the reactivity of mineral surfaces in newly made lesions affected the diffusion ofremineralizing ions from low concentration solutions to the lesion front.
Community Participation and Forest Policies in India
Authors: Pratap Dinesh
Published: November 2010

Community participation emerged as the defining principle of forest policies all over the world in the closing decades of the last century. In India, this came about after the Indian forest policies went through different stages from largely commercial-centric to a community-oriented approach. The access to forests and participation in their management has always been a bone of contention between the state agencies and the local communities. The colonial forest policy of the British and the first forest policy of independent India systematically curtailed the traditional rights and role of forest-dependent communities while claiming to address community demands. After a long and continuous denial of the crucial stake that local communities have in their nearby forests, it was only in late 1980s that they were accorded some space. While the current policies seem to be advancing communities’ role in forest management, yet there are several bottlenecks in terms of their implementation. The dominant role of the forest department, failure to involve community as an equal partner, weak institutional mechanism and inadequate legal back up, among other factors, have obstructed the satisfactory execution of the policies. This article is a critical overview of the changing paradigms of successive forest policies in India and argues that the real participation of the community can be ensured only when it is accorded a meaningful stake in all forest matters affecting the community.
Education as Culture Mapping
Authors: Sabar Bhubaneswar
Published: November 2010

This article deals with issues relating to education of Chuktia Bhunjia tribe of Orissa, highlighting the major factors determining girls’ education in this society. While looking at the low literacy of the girl child, factors like material culture, life cycle rituals and customary cultural norms are found largely responsible for high drop out from school. However, poverty, school timings and need of girl children in household chores are other causes of this. However, few girls have dared to cross the customary laws to carve out a space for themselves, even as the fear of social ostracism forces many parents to stop sending their girls child to schools. Thus, it is pertinent here to find out ‘alternatives’ so as to encourage girls’ education without dismantling their social structure as well as traditional cultural practices. Further, there is a need to redraft, fine tune them with cultural practices and social norms, as the existing policies fail to facilitate equal rights to everybody as enshrined in the Constitution of India.
Agriculture and Energy Subsidy in US and Europe and the World Food Crisis
Authors: Lazo Manuel Lajo
Published: November 2010

This article empirically demonstrates that the European and US globalisation and capitalism in agriculture, food and the agro-industry since the mid-20th century have been supported and powered by subsidies (which at present is 50 per cent of the value of agricultural production in Europe and the US) and technological advances in the cultivation of mainly grains (wheat, corn, rice and barley), oilseeds (especially soybeans), milk and cotton. This led to a major expansion in the periphery of the standard food and textile industries dependent on imports of commodities at artificially low prices and a pattern of food consumption with a growing imported and subsidised component for the urban and rural low-income masses. With the emergence of agro-fuels prompted by OECD countries has begun a process of unification of the global market for food with the fuel or energy market in general. Our proposal—keeping in mind the recent experience of the recession that could threaten to become a global depression like in 1929—is a design to replace the current one-agri-food and energy global systems, seeking the restoration of the validity of the real comparative advantages.
Political Ecology and Social Movements with Reference to Kudremukh Environment Movement
Authors: Sridhar V.K.
Published: November 2010

The main premise of political ecology is that environmental change is not a neutral process amenable to technical management. Rather, it has political sources, conditions and ramifications that impinge on socio-economic inequalities and political process. The article seeks to provide an introduction to the rapidly growing research field of Third World political ecology and provides an overview of the historical development of the field since the 1970s. The theoretical tool has been employed to analyse the case study of kudremukh environment movement. The article raises certain questions like weren’t the priorities of workers considered upon the closure of mining? Why have the trade unions not been able to dictate the central content of bargaining policy for trade unions? Why do NGOs select a particular issue in terms of environmental degradation and play crucial roles as lobbyist and umpire through judicial activism and well as act as interpreters and mediators through the press?
Turnover, Transfer, Absenteeism: An interdependent Perspective
Authors: Dalton Dan R. , Todor William D.
Published: November 2010

While there is a rich tradition of research addressing turnover, transfer, and absenteeism as singular phenomenon, there has been relatively little attention to the various associations among these employee behaviors. We provide rationale and a model that turnover/transfer/absenteeism are interdependent phenomena. Specifically, we argue that levels of employee turnover can be markedly altered by attention to transfer and absenteeism policies within the organization.
Making Sense of Careers: A Review 1989-1992
Authors: Ornstein Suzyn , Isabella Lynn A.
Published: November 2010

The following provides an overview of the field of careers by focusing on research published in the last four years. The information is organized around the major content areas of the field: attraction/selection, socialization, commitment, mentoring, plateaus, voluntary and involuntary separations, work-family conflicts, and demographic impacts. Some general observations and suggestions for future research directions are offered.
An Integrative Framework of Strategic International Human Resource Management
Authors: Schuler Randall S. , Dowling Peter J. , De Cieri Helen
Published: November 2010

The globalization of business is making it more important than ever to understand how multinational enterprises (MNEs) can operate more effectively. A major component of this understanding appears to be the field of human resource management, and in particular, the field of international human resource management (Brewster, 1991; Hendry, 1992; Desatnick & Bennett, 1978; Dowling, 1986; Dowling & Schuler, 1990; Evans, 1986; Laurent, 1986; Tung, 1984). The trend over the past few years has been to identify the linkage of human resource management with strategy and offer an understanding of how single country or domestic human resource management can facilitate organizational understanding and effectiveness (Wright and McMhan, 1992). In this article we attempt to extend this line of work into the international arena. We do this by offering a framework of strategic international human resource management (SIHRM). Anchoring SIHRM in the strategic components of MNEs, namely their interunit linkages and internal operations, strategic aspects of international human resource management are described, Using several theoretical bases, numerous propositions are offered. These propositions reflect the single and multiple influence of the strategic components of MNEs and several exogenous and endogenous factors on SIHR. The intention is to offer a framework that can serve both academics and practitioners in furthering our understanding of strategic international human resource management.
The Stock Market Effects of CEO Succession in Bankrupt Firms
Authors: Davidson Wallace N. , Worrell Dan L. , Dutia Dipa
Published: November 2010

This article examines the effects of CEO successions on stockholder wealth in large firms that are also experiencing bankruptcy. Succession announcements that occurred prior to and subsequent to bankruptcy announcements are associated with positive abnormal returns, and we found a greater incidence of outside succession near bankruptcy than for successions in general. The market’s reaction was also more positive for outsiders than for insiders, and this was especially so when the succession happened after bankruptcy.
Watch the Time Carefully: The Use and Misuse of Time Effects in Management Research
Authors: Bergh Donald D.
Published: November 2010

This article assesses how management researchers have used, and in some cases misused, time effects in their research designs, data analyses, and interpretations. Drawing from a content analysis of studies appearing in the Academy of Management Journal and Administrative Science Quarterly over the years 1988-1992, five different approaches for defining and operationalizing time effects are identified. Evaluation within and across these five approaches reveals three recurring patterns of “time series errors. ” The implications of these “errors “for studies with, and on time are provided.
Configuration Research in Strategic Management: Key Issues and Suggestions
Authors: Dess Gregory G. , Newport Stephanie , Rasheed Abdul M. A.
Published: November 2010

This paper discusses major theoretical and methodological issues that strategic management researchers must consider when developing and testing configuration theories. The theoretical issues include: (1) number of domains, (2) causality, and (3) temporal stability. The methodological issues are: (I) specification of key constructs, (2) effects of data aggregation, (3) the choice of unit of analysis, and (4) the appropriateness of research methodologies. Greater attention to these issues should result in more accurate findings and more meaningful interpretations.