bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypothetical mortality risk associated with spiral tomography of the maxilla and mandible prior to endosseous implant treatment
Authors: Dula Karl , Mini Roberto , Lambrecht Jörg Thomas , van der Stelt Paul Frans , Schneeberger Paul , Clemens Gerard , Sanderink Herman , Buser Daniel
Published: October 2007

Radiation dose delivered from the SCANORA® radiography unit during the cross‐sectional mode for dentotangential projections was determined. With regard to oral implantology, patient situations of an edentulous maxilla and mandible as well as a single tooth gap in regions 16 and 46 were simulated. Radiation doses were measured between 0.2 and 22.5 mGy to organs and tissues in the head and neck region when the complete maxilla or mandible was examined. When examining a single tooth gap, only 8% to 40% of that radiation dose was generally observed. Based on these results, the mortality risk was estimated according to a calculation model recommended by the Committee on the Biological Effects of Ionizing Radiations. The mortality risk ranged from 31.4 × 10−6 for 20‐year‐old men to 4.8 × 10−6 for 65‐year‐old women when cross‐sectional imaging of the complete maxilla was performed. The values decreased by 70% when a single tooth gap in the molar region of the maxilla was radiographed. The figures for the mortality risk for examinations of the complete mandible were similar to those for the complete maxilla, but the mortality risk decreased by 80% if only a single tooth gap in the molar region of the mandible was examined. Calculations according to the International Commission on Radiological Protection carried out for comparison did not reveal the decrease of the mortality risk with age and resulted in a higher risk value in comparison to the group of 35‐year old individuals in calculations according to the Committee on the Biological Effects of Ionizing Radiations.
Changes in TGF‐β1 levels in gingiva, crevicular fluid and serum associated with periodontal inflammation in humans and dogs
Authors: Skalerič Uroš , Kramar Barbara , Petelin Milan , Pavllia Zlatko , Wahl Sharon M.
Published: October 2007

Transforming growth factor‐beta (TGF‐β) represents a family of polypeptide growth factors, involved in embryogenesis, inflammation, regulation of immune responses and wound healing. To determine whether TGF‐β contributes to the evolution of periodontal disease, we assayed TGF‐β levels in gingiva and crevicular fluid of patients with gingivitis and periodontitis. In parallel, TGF‐β was quantified m gingival fluid and serum of beagles with experimentally‐induced periodontitis. Disease was monitored by several clinical parameters including Plaque Index, Gingival Index, probing depth, and epithelial attachment loss. Gingival tissues were obtained from 9 patients at the time of periodontal surgery, and gingival fluid samples were collected from an additional population of 10 periodontal patients. In 14 beagles, experimental periodontitis was induced and gingival fluids collected 6 months later. Fluid was collected by paper strips and volume measured by Periotron. Additionally, sera was collected before and 9 months after the ligature‐induced periodontitis in 7 beagles. The levels of TGF‐β1 were measured by ELISA. In the patients, a significantly higher concentration of TGF‐β1 was observed both in the gingival tissues and fluid samples obtained from the sites with deeper periodontal pockets than in the less involved sites. In beagles, TGF‐β1 levels measured in gingival fluid were elevated in moderate disease, declining in fluid samples obtained from the pockets during more advanced experimental periodontitis. Furthermore, with the progression of experimental periodontitis, a decrease in TGF‐β1 occurred in the sera of the beagle dogs. These data suggest that TGF‐β1 may play a rǒle in the pathogenesis and diagnosis of periodontal disease, and that its actions can be further explored in an animal model.
Are sodium lauryl sulfate–containing toothpastes suitable vehicles for xylitol?
Authors: Assev Synnøve , Wäler Sonni Mette , Rolla Gunnar
Published: October 2007

The hypothesis to be tested in this study was that toothpastes containing sodium lauryl sulfate (SLS) is unsuitable vehicles for xylitol. The bacteriostatic (and cariostatic) effect of xylitol is assumed to be caused by intracellular accumulation of xylitol‐5‐P in plaque bacteria. Experiments were designed to investigate whether presence of SLS would affect the uptake of xylitol by interacting with the bacterial membranes and thus inhibit xylitol‐5‐P formation. It was shown in an in vitro study that even very low concentrations of the strong anionic detergent SLS inhibited uptake of xylitol and xylitol‐5‐phosphate formation by dental plaque totally. The mild nonionic detergent ethoxylated stearyl alcohol (30x EO) had no such effect. In vivo experiments with toothpastes containing xylitol and either the strong or the mild detergent, showed that xylitol in toothpaste with SLS was not available for the plaque bacteria and gave no adaptation to xylitol, whereas in the presence of 30x EO it was available, and a xylitol adaptation was observed. Glucose metabolism, which was also studied for the plaque samples, was not significantly affected by presence of any of the 2 detergents, indicating that the amounts of xylitol in toothpastes were presumably too low to give clinical significant effects, even when mild detergents are used.
Resin bonding to enamel and dentin with one–component UDMA/HEMA adhesives
Authors: Finger Werner J. , Fritz Ulrike B
Published: October 2007

The aim of this study was to investigate the potential of UDMA/HEMA mixtures as priming and sealing components of dental adhesives. The monomers were mixed in weight ratios 100/0, 80/20, 60740, 50/50, 40/60, 20/80, 10/90, and 0/100, light activated, and dissolved in acetone at equal parts. The 60/40 UDMA/HEMA mixture served as a reference which was modified with 5, 10, 20, and 30 parts 4‐MET relative to the mass of the basic monomer mixture. Shear bond strengths (24 h) of resin composite cylinders, bonded with the adhesive monomers on human enamel and dentin, were determined following a total etch technique with phosphoric acid and application of the adhesives in 2 coats on moist tooth surfaces. Average bond strength to enamel was 32 MPa with no difference between the adhesives. On dentin, significantly different bond strengths were found between UDMA (12.9 MPA) and HEMA (19.4 MPa), whereas all binary mixtures bond strengths were not significantly different (mean 16.2 MPa). Addition of 5 to 20 wt% 4‐MET resulted in a significantly increased mean shear bond strength of 22.3 MPa on dentin. At 10%, a maximum mean strength of 25.4 MPa was recorded. It is concluded that mixtures of commonly used polymerizable monomers, characterized by hydrophilic moieties and dissolved in acetone, are promising candidates for effective resin bonding to enamel and dentin, provided application by the moist bonding technique.
Assessment of patients with direct conditioned and indirect cognitive reported origin of dental fear
Authors: Berggren Ulf , Carlsson Sven G. , Hägglin Catharina , Hakeberg Magnus , Samsonowitz Viktor
Published: October 2007

This study investigated the reported conditioned or cognitive origin of dental phobia in 100 adult patients at a specialized dental phobia clinic. It was shown that a majority of patients reported a conditioned background to their dental fear. Patients'avoidance time and level of dental anxiety corresponded to previously reported data for fearful groups. Individuals with an aruosal conditioning etiology of dental fear reported significantly longer avoidance time as compared to individuals with a cognitively learned reaction. With the exception of an elevated level of general fears, most psychometrically assessed emotional reactions were well within normal ranges. However, patients with a non‐conditioned, cognitive etiology reported significantly higher levels of trait anxiety and fear of embarrassment. In addition, a separate analysis among women revealed a greater fear of physical injuries among patients with cognitive etiology.
Potential side effects of dental amalgam restorations
Authors: Bratel John , Haraldson Torgny , Meding Birgitta , Yontchev Evtim , Öhman Sven‐Christer , Ottosson Jan‐Otto
Published: October 2007

The aim of this study was to explore a possible association between health status and self‐reported adverse effects related to dental amalgam restorations. A group of 50 consecutive patients (index group), referred for complaints self‐related to dental amalgam restorations, was compared with a control group of individuals matched by age, sex and postal zip code. The patients underwent an oral, stomatognathic, medical and clinical chemistry examination. Mercury levels were examined in blood, urine and hair. The results revealed that somatic diseases were more common in the index group (38% versus 6%). Symptoms related to cranio‐mandibular dysfunction were reported by 74% of the patients in the index group versus 24% in the control group, and were diagnosed in 62% and 36%, respectively. The oral health status and the number of amalgam surfaces were similar in the 2 groups. No positive skin patch test to mercury was found in any of the groups. The estimated mercury intake from fish consumption, occupational exposure, and mercury levels in blood and urine were also similar and far below levels, where negative health effects would be expected. The correlation between the number of amalgam surfaces and mercury levels in plasma and urine (r= 0.43) indicated a release of mercury from dental amalgam restorations in both groups. Since the mercury levels were similar among index patients and controls, mercury was not a likely cause of the impaired health reported by the patients.
Expression and splicing of the fibronectin gene in healthy and diseased periodontal tissue
Authors: Parkar Mohamed H. , Bakalios Panagiotis , Newman Hubert N. , Olsen Irwin
Published: October 2007

Fibronectin is a major component of the extracellular matrix and is considered to have an important role in chronic inflammatory periodontal disease. The fibronectin gene product has been shown to be subject to alternative splicing in 3 regions, each generating different mRNA transcripts associated specifically with normal adult tissue, embryogenesis, tissue regeneration, and wound healing. In the present study, using the reverse‐transcribed polymerase chain reaction to examine splicing profiles of the primary transcript, we found that healthy periodontal tissue expressed all alternatively spliced embryonic isoforms, indicative of the extensive and ongoing rebuilding processes which occur in these tissues. In marked contrast, only the exon‐skipped transcripts were generated in tissue from chronic inflammatory periodontal disease patients. The loss of the high molecular weight isoforms in lesional tissues may be due to the excess production of inflammatory mediators in this disease, since we observed that high concentrations of the cytokine IL‐1β caused down‐regulation of these transcripts in normal periodontal cells in tissue culture. Moreover, we also demonstrated that growth factors likely to be involved in periodontal regeneration and repair, such as PDGF, IGF‐1 and TGF‐β, elicited pronounced upregulation of the embryonic isoforms of fibronectin in these cells. Although the functional activities of the antigens corresponding to the alternatively spliced variants of fibronectin are not yet known, our finding that they are selectively expressed suggests that they have highly specific roles in both periodontal breakdown and repair.
Expression of Hsc 70, but not Hsp 70, in human third molar dental pulp
Authors: Sens Donald A. , McGuirt Joan P. , Khan Wasil , Howell Robert M. , Todd John H.
Published: October 2007

The constitutive (hsc 70) and inducible (hsp 70) isoforms of heat shock protein 70 are important members of the superfamily of stress related proteins that protect and promote the recovery of cells from physiological and pathologic stress. The goal of this study was to define the baseline expression of hsc 70 and hsp 70 in disease‐free, minimally stressed human dental pulp of the adult 3rd molar. Immunolocalization demonstrated moderate to heavy staining intensity for hsc 70 in both the cytoplasm and nucleus of odontoblasts and fibroblasts comprising the human pulp. Endothelial and smooth muscle cells displayed weak to moderate immunoreactivity for hsc 70 in both the cytoplasm and nucleus. Schwann cells demonstrated only weak nuclear staining for hsc 70. No immunoreactivity for hsp 70 was observed in any cell type in human pulp. Western, northern, and RT‐PCR analysis of pulp preparations confirmed the expression of hsc 70 mRNA and protein within components of the pulp. These results demonstrate that cells of the human pulp express, under conditions of minimal stimulation, a key component of the stress response protein superfamily. The expression of hsc 70 under conditions of minimal stress may provide pulp components an advantage in resisting cell injury when stress occurs.
The Maillard reaction in demineralized dentin in vitro
Authors: Kleter Gijs A. , Damen Jan J. M. , Buijs Mark J. , Cate J. M. Ten
Published: October 2007

The Maillard reaction between carbohydrate and protein has been proposed as a cause of the browning of carious lesions. The aim of the present investigation was to determine the occurrence of this reaction in bovine dentin collagen in vitro and to establish the effect of the reaction on the proteolytic degradation of bovine dentin collagen in vitro. Slices of demineralized bovine dentin were incubated with 0.2 M glucose or buffer for 10 weeks at 37°C. The formation of initial (furosine) and advanced (pentosidine) products of the Maillard reaction in dentin exposed to glucose was confirmed by HPLC. After reduction with NaBH4 to prevent intermediate Maillard products from further reaction, slices were either degraded with collagenase for fluorescence measurement or incubated with trypsin or pepsin to assess enzymatic degradation. Fluorescence characteristic for the Maillard reaction increased in glucose‐exposed slices. Degradation of collagen by pepsin, but not by trypsin, was greatly depressed following glucose pretreatment. This may indicate an altered sensitivity to proteolytic degradation; the Maillard reaction thus has a potential role in caries arrestment.
Osteogenic response to hydroxyapatite‐fibrin implants in maxillofacial bone defects
Authors: Bonucci Ermanno , Marini Ettore , Valdinucci Federica , Fortunate Gianni
Published: October 2007

Bone formation in hydroxyapatite‐fibrin implants has been reported several times. However, available studies refer to experimental animals, or are limited to short periods after implantation. We report the results of histological. histochemical and ultrastructural studies carried out 2.5–8 yr after implantation of non‐resorbable, porous hydroxyapatite (HA) and fibrin glue in human maxillofacial bones. Prominent ossification was found in all cases, with the presence of normally structured spongy bone. HA granules were embedded in the calcified bone matrix. They had not elicited inflammatory reactions and did not induce bone resorption. Ossification was preceded by the appearance of alkaline phosphatase activity on fibroblast‐like cells, and by the formation of dense collagenous layers, similar to osteoid borders, on the surface of HA granules. The early phases of the calcification process occurred in these borders, with the appearance of calcification nodules adjacent to alkaline phosphatase‐positive osteoblast‐like cells. A remodeling process similar to that occurring in normal bones was found in the newly formed bone. These results justify the conclusion that HA‐fibrin implants lead to the formation of long‐lasting bone that does not differ from that of the normal maxillofacial skeleton. Mixing the HA granules with fibrin has the advantage of creating an easily mouldable material which can be adapted to any skeletal surface and stays in place after surgery.
Short‐term reproducibility of pressure pain thresholds in masseter and temporalis muscles of symptom‐free subjects
Authors: Isselée Hans , De Laat Antoon , Lesaffre Emmanuel , Lysens Roeland
Published: October 2007

Pressure pain thresholds (PPTs) of the bilateral masseter and temporalis muscles were assessed over a single day and in between 2 days with the aid of an electronic algometer in 11 males and 11 females. Using a mixed model approach, covariance results were controlled for confounding of gender, day. time of the day and the within‐session replications of the measurements. For every jaw muscle, the first PPT measurement of a session was markedly higher than the last one of that same session. Except for the right temporalis muscles. no significant systematic PPT differences could be observed between male and female subjects. The differences between morning and afternoon sessions were not significant for any of the muscles tested. Although the PPTs measured on the 1st day were systematically lower than those on the 2nd day for the left masseter and temporalis muscles, no significant difference between the time of the day could be observed when the values of the different muscles were grouped within a subject. Analysis of variance showed that the variability induced by the day or the time of the day was similar to the variability of the measurement itself. The inter‐individual variability of PPTs was 2.3 to 9 × higher than the variability observed between trials, sessions or days. The results indicate that the PPT measurement will not be systematically influenced by the time of registration (morning/afternoon) or inbetween consecutive days. In addition, the important inter‐individual differences favor the use of longitudinal within‐subject studies.
Enhancement by bFGF of osteogenesis induced by rhBMP‐2 in rats
Authors: Takita Hiroko , Tsuruga Eichi , Ono Ichiro , Kuboki Yoshinori
Published: October 2007

Subcutaneous implantation of bone morphogenetic protein (BMP) combined with a fibrous glass membrane (FGM) induces cartilage formation in the entire inner area of the membrane within 2 wk. It has been hypothesized that a tight FGM network (1 μm exclusion size) provides immature cells with spaces for penetrating Into the membrane, but not for vascular formation, at least until 2 wk. To test this hypothesis, basic fibroblast growth factor (bFGF), known to be a potent stimulant of capillary formation, was applied to the implant. BMP was combined with FGM in the presence or absence of bFGF. and then implanted subcutaneously into the backs of rats. The bFGF‐supplemented implant caused 1.3 times higher alkaline phosphatase activity and 3 times higher calcium contents at 2 wk. whereas type II collagen contents decreased. thus indicating that bFGF enhances bone formation in BMP/FGM implants. These results suggest that bFGF induces faster and stronger invasion of capillaries into the FGM and destroys its tight network, resulting in acceleration of the ossification process.
Keratinocyte growth factor mRNA expression in periodontal ligament fibroblasts
Authors: Dabelsteen Sally , Wandall Hans H. , Grøn Birgitte , Dabelsteen Erik
Published: October 2007

Keratinocyte growth factor (KGF) is a fibroblast growth factor which mediates epithelial growth and differentiation. K.GF is expressed in subepithelial fibroblasts, but generally not in fibroblasts of deep connective tissue, such as fascia and ligaments. Here we demonstrate that KGF mRNA is expressed in periodontal ligament fibroblasts, and that the expression is increased upon serum stimulation. Fibroblasts from human periodontal ligament, from buccal mucosa. from gingival, and from skin were established from explants. Alkaline phosphatase activity was used as an indicator of the periodontal nature of fibroblasts. Cells were first cultured in DMEM with 0.5% fetal calf serum (PCS) and then incubated for 8 h, and 72 h in fresh DMEM with 10% PCS. Total RNA was isolated and used for Northern blotting with a P32‐labeled KGP cDNA. probe. Total RNA from cultured keratinocytes was used as negative controls. KGF mRNA was found in all cultured fibroblasts. Upon addition of 10% PCS to the cell cultures, an increase in KGF mRNA levels was noticed especially after 72 h. Furthermore. RT‐PCR analysis of material scraped from the tooth root surface indicated the presence of KGF mRNA even in non cultured periodontal ligament cells.
In situ hybridization study of cytokeratin 4, 13, 16 and 19 mRNAs in human developing junctional epithelium
Authors: Feghall‐Assaly M. , Sawaf M. H. , Ouhayoun J. P.
Published: October 2007

Cytokeratins (CKs) are now considered to be reliable markers for following the development and differentiation of epithelial tissue. We have investigated the pathway of differentiation in human developing junctional epithelium using monoclonal antibodies and two‐dimensional gel electrophoresis of mcrodissected tissue to identify CK 19. CK 16. CK 14. CK 13. CK 6. CK 5. CK 4 in the junctional epithelium (JE) over partially erupted human teeth. The CK profile was similar to that of developing oral epithelia. suggesting that the junctional epithelium in teeth during eruption is of odontogenic origin. The present study used in situ hybridization to determine the distribution of the mRNAs of CKs 19. 16. 13 and 4 in human developing junctional epithelium and to examine the correlation between mRNAs and their encoded proteins. CK 19 mRNA was abundant in the basal cell layers of the primary junctional epithelium (PJE) but less concentrated in the suprabasal layers. CK16. 13 and 4 mRNAs were abundant in the basal cell layers of the PJE. Tlie parabasal cell layers reacted intensely to the cRNA probe complementary to CK16 mRNA. as were the reactions in the suprabasal cell layers of the PJE for the CK 13 and 4 probes. Our results demonstrate that the PJE express the genes encoding for CKs 16 and 4 that have been revealed previously only by electrophoresis. They therefore confirm that the PJE is a well‐differentiated stratified epithelium with a complex unique phenotype that produces CKs specific for basal cells (CK 19), CKs associated with hyperproliferation (CK 16). and finally those associated with stratification (CKs 4 and 13). Only synthesis of CK 19 protein and mRNA are strictly parallel. CKs 4 and 13 mRNAs are present in basal and suprasal cells, while their encoded proteins were not. except for CK 13 in suprabasal cell layers of PJE. where the amount of its mRNAs was coincident with the expression of the protein.
Cell proliferation in developing human dental pulp A combined flow cytometric and immunohistochemical study
Authors: Casasco Andrea , Casasco Marco , Calligaro Alberto , Ferrieri Giovanni , Brambilla Eugenic , Strohmenger Laura , Alberici Roberta , Mazzini Giuliano
Published: October 2007

Information concerning cell proliferation and differentiation in dental pulp may be important to understand tooth response to exogenous stimuli. Since few data concerning human dental pulp are available, we have investigated the growth fraction and the localization of proliferating cells in pulp tissue of third molars of young adult human males and females, using flow cytometry and immunohistochemistry. Flow cytometric analysis demonstrates a low proliferative activity of pulp tissue that appears to be confined to radicular pulp, as revealed by immunohistochemical detection of proliferating cells. No polyploid or aneuploid cell populations could be identified, and G2‐blocked cells, if any. represented a negligible cell population. Odontoblasts, cells of the sub‐odontoblastic layer, and cells of coronal pulp were found to be not proliferating under normal conditions. These data provide the basis for future investigations on proliferative activity and regenerative potentiality of human pulp cells in experimental and clinical situations.
The end of science?
Authors: Löe Harald
Published: October 2007

Löe H: The end of science?
On the rôle of human salivary micelle‐like globules in bacterial agglutination
Authors: Young Alix , Rykke Morten , Smistad Gro , Rølla Gunnar
Published: October 2007

The hypothesis to be tested in this in –vitro study was that the salivary micelle like globules (SMGs) have a rôle in the agglutination of some oral bacteria. An attempt to determine the mechanisms for the interactions involved was also carried out. 4 laboratory and 4 native streptococci strains were tested. Human whole (HWS) and parotid (HPS) saliva was collected from 4 subjects, and SMGs were isolated from both salivas, and agglutination was recorded in the various bacterial suspensions over time. HPS, HWS and SMGs isolated from HPS and HWS caused typical agglutination patterns for the mutans strains. Salivary supernatants (without SMGs) caused a much delayed or no agglutination. Electron microscopy showed SMG‐like structures on the surface of the agglutinated bacteria. Addition of pyrophosphate to HPS prevented agglutination, whereas guanidine HC1 prevented normal agglutination of a sanguis strain, and urea had no obvious effect. Together, these results indicate that the SMGs are important in the agglutination of streptococci, and that both calcium‐dependent, electrostatic and hydrophobia interactions may be involved.
The influence of triclosan, zinc or propylene glycol on oral mucosa exposed to sodium lauryl sulphate
Authors: Skaare Anne B. , Rölla Gunnar , Barkvoll Pål
Published: October 2007

Previous studies on triclosan treatment of skin exposed to sodium lauryl sulphate (SLS) indicated a protective role of zinc and an irritant effect of propylene giycol (PG). The aim was hence to examine whether zinc or PG also may affect SLS‐induced oral mucosal reactions, and also to test the influence of zinc in combination with triclosan. 15 healthy dental students participated in this double‐blind crossover study performed in 2 experimental series. They were rinsing 2 x daily with solutions containing (A) 1.5% SLS, (B) 1.5% SLS/0.5% zinc citrate and (C) 1.5% SLS/PG (1:8) in experiment 1, and (D) 1.5% SLS/0.15% tridosan/0.3% zinc citrate and (E) 1.5% SLS/0.15% triclosan in experiment 2. Clinical evaluation by 2 examiners of degree of erythema and oral mucosal desquamations was then performed. The critical micellar concentration was also determined. SLS and SLS/PG. which were not different in effect, evoked significantly more erythematous reactions than SLS/Tri/Zn. This solution was numerically but not statistically better than SLS/PG, and the latter also did lead to significantly less erythema than SLS/PG. In conclusion, the present study revealed no irritation of the oral mucosa due to PG, whereas a protective effect of zinc as well as the anti‐inflammatory effect of triclosan were confirmed.
On the transformation of sulfur‐containing amino acids and peptides to volatile sulfur compounds (VSC) in the human mouth
Authors: Wåler Sonni Mette
Published: October 2007

Halitosis is most often caused by oral conditions. Volatile sulfur compounds (VSC), constituting the major components of oral malodor, are produced by anaerobic, gram‐negative bacteria retained mainly in periodontal pockets or on the tongue dorsum. Sulfur‐containing amino acids serve as substrate for these bacteria. VSC have also been found to have unfavorable effect on the tissue. The aim of this study was to examine whether normal, healthy individuals with no history of halitosis were able to produce VSC from cysteine, when applied as a mouthrinse. A further aim of the study was to investigate and compare the potential of other sulfur‐containing amino acids and peptides as substrates for oral VSC production and to localize the odor‐production sites. A portable sulfide monitor was used for VSC registration. Results showed that all test subjects produced high oral concentrations of VSC upon rinses with cysteine, which thus seems to be a major substrate for VSC production. The other sulfur‐containing substrates had much less effect. It was found that the tongue was the major site for VSC production, and that saliva per se caused low VSC production.
Salivary levels of immunoglobulin A in Triathletes
Authors: Steerenberg Peter A. , van Asperen Ilse A. , Amerongen Arievan Nieuw , Biewenga Jeike , Mol Damaris , Medema Gertjan
Published: October 2007

We Investigated whether the physical exercise of an olympic distance triathlon affected the salivary lgA exerction of triathletes, ad a Biomarker for mucosal immune defence. 42 triathletes participated in the study. It was found that the salivary flow rate was decreased significantly after the race, thereby resulting in a significant reducation of the total salivary lgA output. The salivary Lga concentration (Mg lga/ml) did not differ, but expressed as total salivary protein, a significant reduction was observed. This was on the account of the salivary protein concentration (mg protein/ml), which was significantly increased, in contrast to the lgA secretion, the salivary amylase actitivy was increased significantly after the race. Therefore, our date suggest that the exercise of a triathlon may decrease the level of lgA mediated immune protection at the mucosal surface. As triathletes may during the race be exposed to micro‐organisms present in the swimming water, a decreased IgA‐ mediated immunity during the race may pose triathletes at an increased risk of infections.
Relationship of Serotype, leukotoxin gene type and lysogeny in Actinobbacillus actinomycetemcomitans to periodontal disease status
Authors: Tinogo Eduardo Muniz Barretto , Stevens Roy , Haubek Dorte , Lal Chem‐Hsiung , Balachandran Sukumar , Preus Hans
Published: October 2007

Actinobacillus actinomycetemcomitans has been associated with different forms of periodontities, particularly with localized juvenile periodontitis (LJP). The bacterium possesses several virulence factors which have been shown to interact with the hos immune system. Among these factors, leukotoxin, surface antigens (serotype) and bacteriophages have been suggested directly or indirectly to influence the course of infection. However, few studies have been able to show associations between these factors and periodontal disease, alonw or in combination. Thus, the purpose of the present study was to investigate possible correlations between periodontal disease status and selected virulence factors (serotype, presence of bacteriophages, and the presence of a 530 bp delection in the promotor region of the leukotoxin gene). 36 subjects took part in the study. Serotype c was the most frequently found serotype among periodontally affected subjects, although serotypes a and b were also present, 27 out of 36 strains harbored bacteriophages, and there was strong evidence that some of the bacteriophages were different from the previously characterized ΦAa Phage. actinomyceremcomitans the F‐Fragment phage were more frequently associated with periodontal disease. Five strains, all serotyype b, 3 from LJP patients and 2 from healthy subjects, showed a 530‐bp deletion in the promotor regiion of the leukotoxin gene.
The effect of comonomer composition, silane heating, and filler type on aqueous TEGDMA leachability in model resin composites
Authors: Müller Hermann , Olsson Stina , Söderholm Kari‐Johan
Published: October 2007

Experimental composites using either bisGMA/TEGDMA or UEDMA/ TEGDMA matrices, quartz or barium glass fillers, and 2 different filler silanization methods were evaluated regarding monomer leachability in distilled water. The leached amount was detected and quantified using gas chromatography. The results showed that twice as much TEGDMA is leached from a bisGMA/TEGDMA based composite than from an UEDMA/ TEGDMA based composite, when both contain 50 wt% TEGDMA. The hypothesis suggested that the higher degree of cure of UEDMA/TEGDMA based composites would be reflected in a lower monomer leaching value, and this hypothesis was supported by the findings. Whether such a correlation exists within groups of UEDMA/TEGDMA based matrices having different degrees of cure was not determined and needs to be investigated in future studies. Variables such as filler composition and silane treatment did not affect the leaching values of TEGDMA in water. That finding suggests that future studies should target differences in matrices, and that the need for considering effects of filler composition and silane treatment methods should not receive the same priority.
A new genus of the Zygomycetes
Authors: Barron G. L.
Published: October 2007

Brachymyces is described as a new genus of the Zygomycetes based on a single species, Brachymyces megasporus, isolated from garden soil. This species produces one to four very large blackish-brown conidia at the apex of short, stout, hyaline conidiophores. In contrast to the massive spores, the vegetative hyphae are extremely fine in diameter (ca. 1.0 μm). Hyphae attack rotifers which become filled with broad, convoluted, assimilative hyphae. Neither resting spores nor sexual spores were observed. The fungus appears to be related to Rhopalomyces in the Helicocephalidaceae of the Mucorales.
Spore morphology in Coleosporium plumeriae
Authors: Traquair J. A. , Kokko E. G.
Published: October 2007

Coleosporium plumeriae Pat. is a rust fungus (Melampsoraceae) found on Plumeria species. The spermagonial and aecial states are unknown. Light and scanning electron microscopy of uredinia have revealed catenulate, verrucose urediniospores with scattered germ pores. We expect that, as in other Coleosporium species, the urediniospores are morphologically similar to aeciospores. The urediniospore ornamentation consists of distinctive, annulate, bluntly capitate tubercles. Light microscopy of telia indicates that teliospores are smooth, gelatinous, and one celled, quickly appearing four celled with division of the protoplast into an internal four-celled basidium.
Some nutritional factors regulating formation of sclerotia of Sclerotium rolfsii
Authors: Zoberi M. H.
Published: October 2007

Growth requirements of Sclerotium rolfsii Sacc. were studied. Sclerotia developed on solid media and primordia started forming when the entire surface of the media in the culture plates was covered with mycelia. The optimal temperature for sclerotium formation varied between 20 and 37 °C. A wide range of carbon sources stimulated the formation of sclerotia, glucose clearly being the most effective. Sclerotia failed to form when a carbon source was absent from the medium. Sclerotia developed in the presence of all the nitrogen sources tested; the highest yield was obtained on (NH4)2SO4 and poorest on L-lysine. Experiments on the growth response to different vitamins showed that S. rolfsii produced sclerotia even on the medium lacking vitamins; the best harvest was obtained on the medium containing ascorbic acid. Media lacking potassium, magnesium, calcium, and sodium supported a good growth of mycelium, but sclerotia failed to form in the medium lacking potassium.
The waterweeds (Elodea and Egeria, Hydrocharitaceae) in Canada
Authors: Catling Paul M. , Wojtas Walter
Published: October 2007

A study of herbarium material of Elodea spp. and Egeria densa was undertaken to document status in Canada and to evaluate existing methods of identification. Except in Elodea longivaginata, nonflowering plants are 2 – 3 times more common than flowering plants and females are more common than males. Leaf width partially separates E. canadensis and E. nuttallii males but not females. The ratio of pistillate sepal length versus leaf width separates female E. canadensis from female E. nuttallii, but intermediates exist. Nonflowering plants with leaf widths of 1.8 – 2.2 mm are treated as unknowns. Bifid styles are characteristic of E. longivaginata. Keys, descriptions, and drawings based on Canadian material are provided. The introduced Egeria densa occurs rarely in southwestern British Columbia. Elodea longivaginata and E. nuttallii are both rare native species, the former occurring in southern Alberta and southern Saskatchewan and the latter occurring in southern Ontario and southern Québec, Nova Scotia, southern Manitoba, and southern British Columbia. Elodea canadensis is a widespread native species occurring throughout southern Canada.
Marine fungi from Seychelles. II. Lanspora coronata gen. et sp. nov. from driftwood
Authors: Hyde Kevin D. , Jones E. B. Gareth
Published: October 2007

Lanspora, a new marine pyrenomycete from driftwood collected in the Seychelles is described with L. coronata as the type species. The genus is compared with the marine genera Corollospora, Eiona, Halosphaeriopsis, Ocostaspora, and Remispora.
Chara buckellii, a euryhaline charophyte from an unusual saline environment. I. Osmotic relations at steady state
Authors: Hoffmann Rosanne , Bisson Mary A.
Published: October 2007

Chara buckellii is a euryhaline alga that provides a model for the comparative study of osmotic relations under different salinity regimes within the same species. Chara buckellii is native to a saline lake (Waldsea Lake) in which the major ionic constituents are Mg2+ and [Formula: see text] as well as Na+ and Cl− (approximately 110 mM each). Plants were cultured in artificial Waldsea water, ordinary seawater diluted to match the osmotic pressure of Waldsea water (375 mosmol/kg), and freshwater. The major osmotica in the vacuole of Waldsea-water and seawater cells are K+, Cl−, and Na+, although seawater cells have significantly more Na+ than Waldsea-water cells. The vacuole of freshwater cells contains primarily K+, Cl−, and Mg2+. Turgor is regulated in a range from 323 ± 5 to 212 ± 7 mosmol/kg when the external osmotic pressure ranges from 5 (freshwater) to 567 (1.5 × Waldsea water) mosmol/kg. Waldsea-water cells regulate turgor primarily with K+ and Cl−, whereas seawater cells regulate with K+, Cl−, and Na+. The possible role of Mg2+ in the early stages of turgor regulation is discussed. Cytoplasmic K+ concentrations are also reported and are comparable with those found in the literature for related charophyte genera. The results presented here are compared with modes of turgor and osmotic regulation in other euryhaline and freshwater algae.
The vegetative and floral development of the hybrid grape cultivar ‘Ventura’
Authors: Posluszny Usher , Gerrath Jean M.
Published: October 2007

The vegetative and floral development of the hybrid grape cultivar ‘Ventura’ was studied. A tendril forms opposite the last-formed leaf on the shoot but is slightly delayed in its initiation. Six nodes and 10 primordia complete one leaf–tendril initiation cycle. The inflorescence develops at the same site and is initially indistinguishable from the tendril. Inflorescence primordia are initiated on the upper arm, first opposite each other in a decussate arrangement and then apparently spirally. Each inflorescence primordium may subsequently initiate two lateral primordia, which become subtended by bracts. These in turn may repeat the pattern so that ultimately third- or fourth-order cysmose inflorescence branches may be produced. During floral development the calyx is initiated at first as three primordia, followed by a ring, which ultimately develops five lobes. The five corolla primordia alternate with the sepals. The five stamen primordia are initiated opposite the petals. The gynoecium initiates as five primordia, which later become a ring. Two septae are initiated opposite each other on the inner flank of the ring, forming the two-loculed ovary. Each septum forms a placenta, giving rise to two ovules. The upper portion of the gynoecial ring grows up over the ovules and forms the short style and discoid stigma.
Évolution de paramètres morphologiques au cours du cycle de croissance de Callisia fragrans (Commelinaceae)
Authors: Souza I. Barcellos de , Lauri P. E. , Blanc P.
Published: October 2007

The growth habits in Callisia fragrans are studied in relation to the variation of simple morphological parameters such as the leaf area and the internode length and diameter. The architecture of this species being simple, as in many Monocotyledons, these parameters are the main morphological indicators for the different phases of the biological cycle. Five phases have been distinguished: the stolon, the establishment of the leafy stem, the indefinite growth of the leafy stem, the transition to flowering, and the final stage of flowering with the production of axillary flowers. The establishment of the leafy stem and the transition to flowering are two evolutionary phases while the others are stabilized. The quantitative study of the parameters shows that the stem diameter is always positively correlated to the leaf area while the internode length is negatively correlated to the leaf area mainly during the evolutionary phases. The internode lengthening coefficient, which expresses the internode shape, is negatively correlated to the leaf area. The correlations in C. fragrans are compared to those observed in previous studies, and some general laws concerning the evolution of the morphological parameters are formulated.
Sand movement and vegetation in the Apostle Islands, Lake Superior
Authors: Middleton Beth A. , Schimpf David J.
Published: October 2007

Recent sand movement was inferred from grain morphology, modal grain size, and grain size distributional skewness of samples from the surfaces of beach–dune landscapes. Negative skewness indicated recent net deflation, and either positive skewness or small modal grain size indicated recent net aeolian accretion. Large grains that were shiny and angular indicated surfaces that could not have been deposited by wind. Net deflation occurred where vegetational cover was below 10%, in foredunes and an interdunal blowout. All other sites in dunal, interdunal, or forested zones showed evidence of net accretion or a balance of accretion and deflation. Net accretion was evident in locations with as little as 15% cover. Relationships between sand movement and vegetational composition could not be separated from relationships with total cover. The sandy foreland of one island was bulldozed during the 1950s. This apparently brought coarser Holocene beach deposits near the surface, which limited the severity of blowout by providing a deflation armor. Ammophila breviligulata has not recolonized the interdunal zone of this island, though it persists in this zone on the other islands. The study of grains in cores may reveal the history of vegetational cover at a site.
Late Holocene reproductional patterns of Pinus sylvestris and Picea abies at the forest limit in central Sweden
Authors: Kullman Leif
Published: October 2007

The age structure was studied of two stands of Pinus sylvestris L. and Picea abies (L.) Karst. growing on "fire-safe," opposing (north- and south-facing, respectively) slopes at the forest limit in the Scandes Mountains, in central Sweden. It is suggested that the spatial species segregation is due to different microclimatic demands during seedling establishment and early survival stages. Establishment of pine correlated positively with the mean "tetraterm" (June – September) air temperature over 20-year periods (1861 – 1980). A sequence of thermally favourable years appears to be important for population net growth at the forest limit. Establishment of spruce may relate to an absence of early summer drought, stable snow cover during the winter, and certain high-temperature demands for seed maturation. The extant pine population died off almost entirely during the climatic deterioration of the Little Ice Age (prior to A.D. 1700). From the mid-18th century onwards a new pine population was established, the seed parents being the few remaining survivors from the foregoing decimation. This process conforms broadly with the known pattern of climatic change. After the climax of the Little Ice Age spruce colonized new territory, a consequence of the summer warming combined with the still fairly humid conditions in early summer. No spruce established during the climax phase of warming during the 20th century (A.D. 1925 – 1940).
Mycorrhizae of alpine fell-field communities on soils derived from crystalline and calcareous parent materials
Authors: Lesica Peter , Antibus Robert K.
Published: October 2007

The degree of vesicular–arbuscular mycorrhizal root colonization of alpine fell-field plants was measured at six sites in the northern Rocky Mountains of Montana and Wyoming. Soils derived from calcareous or acidic crystalline parent materials were analyzed for chemical and physical properties and vesicular–arbuscular mycorrhizal fungal propagule density. Soils associated with calcareous parent materials had finer texture, higher pH, and higher levels of calcium, sodium, and silicon. Viable vesicular–arbuscular mycorrhizal propagule density was positively correlated with plant canopy cover. Typical vesicular–arbuscular mycorrhizal colonization occurred in 84% of the species examined. Vesicular–arbuscular mycorrhizal root colonization was significantly greater on soils derived from calcareous parent materials. Alkaline pH and high levels of calcium associated with calcareous soils may result in these soils being functionally more phosphorus deficient than are crystalline soils. Phosphorus deficiency may partially explain the higher levels of vesicular–arbuscular mycorrhizal colonization observed.
Patterns of within-tree variation in a population of Pinus ponderosa
Authors: Maze Jack , Scagel R. K. , Bohm L. R.
Published: October 2007

The amount and structure of within-individual variation in different aged and sized individuals in a population of Pinus ponderosa were compared using multivariate analytical techniques. We wished to determine if the increase in variation and progressive between-plant differentiation that occur with ontogeny of part of a plant are also manifested by entire plants as they age or increase in size. We detected some evidence of increasing differentiation with age or size. The impact on multivariate descriptors of within-tree variation, age and size of trees, microsite differences where the trees grew, and indicators of the climate at the time the trees became established was estimated using ratios of sums of squares. The error term accounted for most of the variation in the data. No single term (age, size, or site) accounted for more than 5% of the variation in the data. Terms that accounted for more than 10% of the variation in the data were either past climate (an extrinsic factor), or interaction terms assessing past climate, site (an extrinsic factor), size (a combination of extrinsic and intrinsic factors), and age. An impact of extrinsic factors on within-tree variation is not surprising since such factors determine which specific trees survive. Furthermore, since natural selection is the result of extrinsic factors, natural selection may have its major impact on within-tree variation. That interaction terms account for within-tree variation may be taken as evidence that selection is the result of many interacting, as opposed to single, factors.
Totipotence du péricycle des organes souterrains et aériens de Rorippa sylvestris. II Régénération de racines et de bourgeons à partir de feuilles détachées ou de fragments foliaires cultivés in vitro
Authors: Projetti Marie-Laure , Chriqui Dominique
Published: October 2007

When detached and placed on water, leaves of Rorippa sylvestris (Brassicaceae) can rapidly initiate roots and subsequently buds at their proximal end. This ability can be modulated through in vitro culture of leaf explants with exogenous growth hormones. Indoleacetic acid enhances both rhizogenesis and caulogenesis with optimal responses at 10 mg∙L−1. Kinetin inhibits the two processes when applied at low concentration (0.05 mg∙L−1) and leads to necrosis above 0.1 mg∙L−1. When applied simultaneously or as a short pretreatment (48 h), indoleacetic acid cancels the toxic effects of kinetin and increases budding. Budding always occurs after rhizogenesis. In all the experiments, roots and buds arise from reactivation of cells belonging to the pericycle surrounding the vascular bundle and located near the protoxylem vessels. Sequential treatments applied in order to induce early morphogenetic reorientations in this totipotent layer are also presented. The double organogenetic ability of the pericycle is discussed as well as the absence of interconversion between root and shoot meristems.