bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinants of oral health in a group of Danish alcoholics
Authors: Hede Børge
Published: October 2007

The purposes of this survey were to describe dental health in a group of alcoholics and to analyze the influence of social background, dental health behavior and alcohol‐related variables on dental health among alcoholics. The dental health in a group of consecutively admitted alcoholics (n=195) was described with respect to number of teeth present, DMFS. DS and the prevalence of dental erosion, removable dentures, edentulousness, and untreated dental decay. No major differences were found with respect to number of teeth and dental caries (DMFS). when compared to reference figures of the general population. As to untreated decay, however. 3‐5 x more actual decayed surfaces were found among the alcoholics. In the multivariate analyses, neither DMFS, nor untreated decay were found to be associated with alcohol‐related indicators. These variables were, however, related to variables of social background and dental health behavior. As to number of teeth present, an association was found with duration of alcoholism, but this relationship was eliminated, when the analysis was controlled with respect to social situation. In contrast, dental erosion was related to duration of alcoholism irrespective of confounding control of dental health behavior and social situation. Hence, the study indicates that oral health in alcoholics can be explained mainly by social situation and dental health behavior and not by variables associated directly with alcohol consumption. An exception was the presence of dental erosion, which was associated with the exposure to alcohol.
Estimation of prophylactic measures in Swedish public dental health care Results from a questionnaire
Authors: Sundberg H. , Bjerner B. , Sjögren K.
Published: October 2007

The aim of the present investigation was to map the presence of prophylactic measures in organized Swedish dental health care systems, focusing on personnel working with children and adolescents. The study was conducted by sending a questionnaire to all public dental clinics in Sweden (830 clinics in all). The results showed that collectively – performed prophylactic measures were given at 66% of the child health centers/ child day care centers and at 63% of the pre‐schools. 51% of all clinics replied that they performed some kind of fluoride administration collectively (mainly fluoride varnish application or fluoride mouthrinses). 34% of all clinics used fluoride varnishes at the ages from 6 to 12 years, and collectively‐performed fluoride mouthrinsing in schools at these ages was carried out by 16% of the clinics. 26% of all the clinics answered that they aimed at increasing the time spent on prophylactic measures compared to only 2% that were planning to decrease this time. The remaining 12% aimed at maintaining the time spent at the present. Prophylactic measures were performed individually by 49% of the clinics, whereas 50% of the clinics preferred a combination of individually and collectively performed measures. It can be concluded that the preventive measures against dental caries in Swedish public dental care is mainly focused on individually performed prophylaxis.
Coordinated electromyographic activity of the human masseter and temporalis anterior muscles during mastication
Authors: Ferrario Virgilio F. , Sforza Chiarella
Published: October 2007

The present report aimed at evaluating the within‐ and between‐subject electromyographic coordination between the masseter (M) and temporalis anterior (T) muscles during the performance of a standardized chewing task. Electromyographic activity of M and T muscles was recorded in 60 young healthy adults (30 men. 30 women) during two 15‐s unilateral mastications of gum. Left‐right differential potentials (δM = MR‐ML. δT = TR‐TL) were computed and the moduli were calculated. The maximum modulus relative to each masticatory cycle was located, and each modulus and differential potential were expressed as a % of the maximum modulus for each subject and chewing trial. For each subject and chewing side, the masticatory frequency was computed, and statistics of the moduli as %s of the maximum were determined by means of bivariate analysis. Within‐subject repeatability of the unilateral chewing patterns was good. Mean population values for the modulus position (bivariate analysis), chewing frequency, and maximum modulus of the differential potentials (univariate statistics) were computed. A significant gender difference was found for the masticatory frequency, with larger values in men than in women. Conversely, no gender or side differences were found for the mean values of the maximum modulus or for the mean position of the percentage moduli. The chewing test applied allowed the evaluation of the neuromuscular coordination during the performance of a standardized physiologic activity. In particular, it quantified the within‐subject and chewing side repeatability of the muscular pattern.
Apoptosis in human and rat dental pulp
Authors: Vermelin Laurent , Lécolle Sylvie , Septier Dominique , Lasfargues Jean‐Jacques , Goldberg Michel
Published: October 2007

Apoptotic cells were visualized in human premolar and rat molar pulps using either the TUNEL method, which stains DNA strand breaks by in situ nick end labeling, or labeling sections with an anti‐transglutaminase antibody. Apoptotic cells were evident at the periphery of the pulp, mostly in a sub‐odontoblastic location, and were more numerous in the crown than in the root region of the pulp. Most odontoblasts were unlabeled. A few apoptotic nuclei in the pulp of rat molars displayed the characteristics of chromatin condensation, as observed by electron microscopy. Many cell debris resembling apoptotic bodies were also observed. The 3 methods support the occurrence of apoptosis in the dental pulp. As this phenomenon was observed in healthy teeth, apoptosis is probably involved in the regulation of the pulp cell population.
Matrix metalloproteinases‐1 and ‐8 and TIMP‐1 mRNA levels in normal and diseased human gingivae
Authors: Aiba Toshifumi , Akeno Nagako , Kawane Tetsuya , Okamoto Hiroshi , Horiuchi Noboru
Published: October 2007

Interstitial collagenases, including matrix metalloproteinase‐1 (MMP‐1) and ‐8 (MMP‐8), serve as initiators of extracellular matrix destruction in periodontal disease. Collagenase activities are mainly regulated by tissue inhibitors of metalloproteinases (TIMPs). We tested the effects of inflammation on MMP‐1 and MMP‐8 gene expression in periodontal disease. To determine the relative abundance of these mRNAs in gingiva, we used a reverse transcription‐polymerase chain reaction (RT‐PCR) assay. Gingival biopsies were divided into 2 groups; a control group and an inflamed group with severe gingivitis or periodontitis. The MMP‐1 mRNA levels were significantly elevated in inflamed gingiva, while the levels of the MMP‐8 transcript were not different in the 2 groups and barely detectable by RT‐PCR assay. The expression of the TIMP‐1 gene was not altered, and remained higher than any of these other genes in both control and diseased gingivae. These results suggest that MMP‐1 rather than MMP‐8 may play an important role in the initiation of collagen degradation in periodontal disease. However, the possibility remains that MMP‐8 plays an important role in periodontal tissue destruction, since the mRNA abundance and not the enzyme activity was assessed.
Controlled study of the association of smoking with lactobacilli, mutans streptococci and yeasts in saliva
Authors: Sakki Tero , Knuuttila Matti
Published: October 2007

The effect of smoking on salivary microbe levels was studied in 780 subjects by multivariate analysis, taking into account some confounding factors. Lactobacilli, mutans streptococci and yeasts were detected with Dentocult‐LB®, Dentocult‐SM® and Oricult‐N® tests. The explanatory variables considered were gender, presence of natural teeth, presence of removable denture, presence of decayed teeth, toothbrushing frequency, use of sugar in coffee or tea. consumption frequency of sugary products, secretion rate of stimulated and unstimulated saliva, buffering capacity of saliva, pH of saliva, oral hygiene and tobacco smoking habits. Smoking was strongly associated with higher lactobacilli counts and presence of yeasts, independently of oral status, hygiene or salivary factors. The relation between smoking and mutans streptococci was weaker. The overall associations of lactobacilli and yeasts with the study variables followed a very similar pattern.
Inability of calcium hydroxide to induce reparative dentinogenesis at non‐peripheral sites of dog dental pulp
Authors: Tziafas Dimitrios , Veis Alexander , Alvanou Athanasia
Published: October 2007

The ability of 2 calcium hydroxide‐containing materials to induce initiation of reparative dentinogenesis was tested at sites remote from the dentinogenically‐active regions of the pulp periphery. Pieces of the cements, Dycal and Life, were implanted in central parenchymal sites of dog dental pulps for periods of 6, 14 and 42 days, respectively. Similar pieces were placed in peripheral capping sites as controls. The responses were analyzed by light and transmission electron microscopy. Induction of tubular dentin matrix lined with elongated and polarized odontoblastlike cells was only seen at peripheral capping sites. In response to the centrally implanted cements, only atubular hard tissue with lining fibro–blast–like cells was deposited.
Presence of bacteriophage AaΦ23 correlates with the population genetic structure of Actinobacillus actinomycetemcomitans
Authors: Haubek Dorte , Will Karin , Poulsen Knud , Meyer Jürg , Kilian Mogens
Published: October 2007

Several bacteriophages associated with the oral bacterium Actinobacillus actinomycetemcomitans have been identified. Lysogeny might affect the virulence of this bacterium, which has been implicated in the etiology of juvenile and adult periodontitis. We have determined the presence of bacteriophage AaФ23–related DNA sequences among 185 A. actinomycetemcomitans strains belonging to 2 well‐characterized collections and have related the findings to the population genetic structure of the collections. 2 cloned AaФ23–specific DNA probes were used in Southern blot hybridization experiments to detect homologous sequences in whole‐cell DNA of the strains. DNA from 65 (35%) of the 185 strains hybridized to either of the DNA probes. The majority (74%) of the hybridizing strains showed an identical hybridization pattern, indicating presence of phage AaФ23. Whole‐cell DNA from the remaining hybridizing strains hybridized to the probes with different patterns, indicating that DNA sequences related to but different from phage AaФ23 occur in these strains. The majority (81%) of the strains which harbored phage AaФ23 were of serotype a, whereas serotype d strains appeared to be resistant to infection with this phage. There was a clear correlation between hybridization patterns and genetic subdivisions based on our previous population genetic analyses of A. actinomycetemcomitans. However, there was no significant correlation between occurrence of AaФ23 among A. actinomycetemcomitans strains and the periodontal status of the patients from whom the isolates were obtained, suggesting that this bacteriophage does not significantly influence the virulence of A. actinomycetemcomitans.
The start of caries decline and related fluoride use in Norway
Authors: von der Fehr F. R. , Haugejorden O.
Published: October 2007

The objective was to determine the start of caries decline and to estimate the use of fluorides about this time. The material consisted of service reports from the Norwegian municipal School Dental Services (SDS) and the county‐based Public Dental Service (PDS), literature reports, private sales and marketing statistics, and a national health survey. The national data for the permanent dentition demonstrated a distinct decline in the average number of filled tooth surfaces from around 1970. Counties were grouped as “early”, 1970, and “late”, 1971. The 5 “early” counties showed the decline to be evident in 1968. Several local districts reported caries reductions since 1963, following the implementation of fluoride programs. Altogether, there was a steady increase in the % of schoolchildren taking part in organized brushing or rinsing programs from 1960. In 1970, 60% of the schoolchildren regularly took part in the supervised fluoride programs. From September 1971, 0.1% fluoride dentifrices became generally available over the counter in retail stores. In 1972, 32–54% of all toothpaste delivered or sold was fluoridated. The distinct time interval between the caries decline and the availability of fluoridated toothpaste rules out the possibility of an interaction before 1971. The extensive activities with fluoride‐based preventive programs in the SDS and PDS have probably been the major factors behind the decline in the late 60s/early 70s.
Effects of frequent mouthrinses with palatinose and xylitol on dental plaque
Authors: Lingström Peter , Lundgren Fredrik , Birkhed Dowen , Takazoe Ichiro , Frostell Goran
Published: October 2007

The aim was to evaluate the effects of frequent mouthrinses with palatinose, xylitol and a mixture of palatinose and xylitol on plaque pH, plaque formation and cariogenic microorganisms. 15 subjects refrained from toothbrushing during 3 test periods and rinsed 15 × daily for 4 d with 10 nil of: (1) 50% palatinose, (2) 37.5% palatinose+ 12.5% xylitol, or (3) 50% xylitol. A contrast period with no mouthrinses was also carried out. The 4 periods were carried out in a randomized order with a cross–over design. After the 4–day periods, 3 parameters were measured: (1) plaque pH during the first 30 min after a mouthrinse with palatinose, a mixture of palatinose and xylitol or xylitol alone, directly followed by a 2nd rinse with 10% sucrose; (2) number of mutans streptococci and lactobacilli in plaque and saliva; (3) plaque index. The most pronounced pH drop for the sugar substitutes was found when rinsing with 50% palatinose after the palatinose period, and the least pH drop with 50% xylitol after the xylitol period. The sucrose rinse gave similar pH fall after all 4 periods. The microbial data showed no differences between the 4 periods, but the mutans streptococcus counts in saliva decreased after the xylitol period in contrast to the 3 other periods. Regarding the plaque index, xylitol gave lower scores compared to the other 3 periods.
Effects of xylitol, xylitolsorbitol, and placebo chewing gums on the plaque of habitual xylitol consumers
Authors: Söderling Eva , Trahan Luc , Tammiala‐Salonen Tuulikki , Häkkinen Lari
Published: October 2007

Xylitol reduces plaque but the reduction mechanism is largely unknown. The main aim of the present study was to determine whether the xylitol‐induced reduction in the amount of plaque and the number of mutans streptococci could be demonstrated in subjects with (presumably) high levels of xylitol‐resistant (XR; not inhibited by xylitol) mutans streptococci acquired following previous xylitol consumptions. 37 healthy dental students participated in the double‐blind study. All subjects had been uncontrolled, habitual consumers of xylitol‐containing products for at least 1 yr before the study, A 1‐month washout period was followed by a 2‐week test period during which either xylitol, xylitol‐sorbitol or unsweetened chewing gum base was chewed 3–5 × a day. Plaque and saliva samples were collected at baseline and at the 2‐week point for determination of the amount of plaque, microbiological variables, and hydrolytic enzymes. Mixtures of xylitol and sorbitol seemed to perform equally well with respect to reduction in the amount of plaque but not the number of mutans streptococci. Thus, polyols were the active ingredients of chewing gums able to modulate the amount of plaque and its microbial composition. Xylitol reduced plaque with a mechanism which appeared not to be associated with the study‐induced changes in the proportion (%) of mutans streptococci in plaque, the number of salivary mutans streptococci, the proportion of XR strains in plaque or saliva, or the hydrolytic enzyme activities of plaque.
Representation of verbal pain descriptors on a visual analogue scale by dental patients and dental students
Authors: Tammaro Stefano , Berggren Ulf , Bergenholtz Gunnar
Published: October 2007

Verbal rating scales (VRS), composed of ranked pain descriptors, are often employed in pain research. Factors that may influence the subjective pain intensity values, however, are not well established. In this study, 5 common pain descriptor adjectives were represented on a visual analogue scale (VAS) by a group of 80 dental students, by a group of 48 patients undergoing periodontal therapy, and by a group of 31 dental phobic patients. It was thought that each group of individuals on conducting the test represented a different degree of apprehension, ranging from a relaxed to a very tense status. There were differences in the interpretation of the pain descriptors between groups. Furthermore, age seemed to influence the interpretation of the pain descriptors. No correlation was found with gender. The descriptors did not divide the analogue scale into equal segments. 71% of all subjects gave the adjective “mild” a lower pain intensity representation than the adjective “weak”, while the order was reversed among remaining subjects. Findings cast doubt on the reliability of VRS and the data handling methods commonly adopted in clinical pain research.
Comparison between cephalometric classification methods for sagittal jaw relationships
Authors: Hurmerinta Kirsti , Rahkamo Auli , Haavikko Kaarina
Published: October 2007

The present study evaluated how 2 widely used cephalometric sagittal analyses, ANB angle and WITS appraisal, classify skeletal classes I, II, and III in a random selection of 497 Finnish boys aged 4–20 years. This distribution was also compared with the visual inspection of cephalometric structures judged by 2 university instructors in orthodontics. The results, showed remarkable differences and even sparked controversy concerning classification of the sagittal jaw relationships. The ANB angle and the WITS appraisal emphasized the role of class II based on a failure to distinguish the proportion of class I. The low‐angle influence skewed the distribution of the ANB pattern in the class III direction, and the WITS pattern, conversely, towards class II. High‐or low‐angle influence had only minor effects on the visual inspection of cephalometric structures. This cross‐sectional study showed an age‐related decreasing mean value for the ANB angle and increasing mean value for the WITS appraisal, thus explaining the remarkable difference in the distribution of sagittal classes. However, the findings of age‐related changes makes the use of the fixed norms questionable. For extreme or controversial cephalometric interpretations, visual inspection provides an essential aid in diagnosis and skeletal classification.
Impact of nocturnal bruxism on mercury uptake from dental amalgams
Authors: Isacsson Göran , Barregård Lars , Seldén Anders , Bodin Lennart
Published: October 2007

The mercury (Hg) release from dental amalgam fillings increases by mechanical stimulation. The aim of this study was to investigate the possible impact of nocturnal bruxism on Hg exposure from dental amalgams and to evaluate the effect of an occlusal appliance. 88 female patients from an orofacial pain clinic with a complete maxillary and mandibuiar dentition, a normal frontal vertical overbite with cuspid guidance, and at least 4 occlusal amalgam fillings in contact with antagonists in intercuspidal position, were examined with the Bruxcore bruxism monitoring device to measure the level of on‐going nocturnal bruxism. Based on the degree of abrasion recorded, the subjects were divided into a group denned as bruxists, (n= 29), another group defined as non‐bruxists, (n= 32), serving as controls, the intermediate group being discarded. The Hg exposure was assessed from the Hg concentration in plasma and urine, corrected for the creatinine content. In a regression model with bruxism as the only explanatory variable, no significant effect of bruxism was found, but when the number of amalgam fillings, chewing gum use, and other background variables were taken into account, there was a limited impact of bruxism on Hg in plasma. The nocturnal use of an occlusal appliance did not, however, significantly change the Hg levels. This study indicates that mechanical wear on amalgams from nocturnal bruxism may increase the Hg uptake, but the magnitude of this effect seems to be less than from the use of chewing gum.
Dental maturity in children of short stature, with or without growth hormone deficiency
Authors: Krekmanova Larisa , Carlstedt‐Duke Jan , Brönnegård Mikael , Marcus Claude , Gröndahl Eva , Modéer Thomas , Dahllöf Göran
Published: October 2007

The aim of this investigation was to study dental maturity in healthy prepubertal children of short stature (height < −2 SD), with or without growth hormone (GH) deficiency, compared to healthy controls. The GH‐deficient group (GH level < 10.0 μg/l) included 29 children (11 female. 18 male) with a mean age of 10.2 ± 2.2 years. The GH non‐deficient group consisted of 17 children (5 female. 12 male) with a mean age of 8.5 ± 2.1 years. All the children were evaluated for serum concentrations of IGF‐1, alkaline phosphatase (ALP), triiodthyronin (T3), thyroxine (T4). thyroid‐stimulating hormone (TSH). and fasting plasma insulin: height and bone age were also recorded. Dental maturity was determined from panoramic radiographs. The mean difference between the dental and chronological ages was −0.67 ± 0.89 years in the GH‐deficient group compared to 0.23 ± 1.07 years in their controls: in the GH non‐deficient group the difference was −0.95 ± 0.82 years compared to controls 0.16 ± 1.06 years in their controls. Compared to chronological age. both bone and dental age were lower in the GH‐deficient and GH non‐deficient groups. It is concluded that children of short stature, both GH‐deficient and GH non‐deficient, exhibit a delayed dental age compared to their chronological age‐ and sex‐matched controls. A multiple stepwise regression analysts showed that the sitting height and GH level were the only significant factors associated with dental maturity.
On the value of research in health care
Authors: Afseth John
Published: October 2007

This paper describes 3 important myths that reduce the political impact of academic research in healthcare and reviews data on the social return of such research. The myths are (i) scientists' interest in pursuing issues without concern for value to society; (ii) industry and private investors should fund more of society's basic research; (iii) Academic research can be improved by better administration. A recent study on return on investment in academic research in general is discussed as well as more specific studies on research related to healthcare. Examples include the BCG and Polio vaccines that today saves Norway more in healthcare costs than the entire public bill for drugs. Some factors that explain why research is undervalued are reviewed, notably rapid changes making benchmarking difficult, insufficient routines in accounting, changing goals, and unpredictable outcomes.
The resistance of titanium tetrafluoride‐treated human enamel to strong hydrochloric acid
Authors: Büyükyilmaz Tamer , Øgaard Bjørn , Rølla Gunnar
Published: October 2007

The acid resistance of TiF4‐treated enamel was investigated to establish a possible treatment modality for endogenous dental erosion. Enamel slabs were prepared from human molars and treated with solutions of TiF4. Scanning electron microscopy (SEM) and microhardness testing were used to examine the effects of the exposure of the treated enamel to strong acid. SEM micrographs showed the presence of heavy deposits on enamel surfaces. The surface coating, formed following TiF4 application, appeared to be resistant to severe acid attacks. Microhardness measurements showed that TiF4 treatment inhibited enamel softening. It is concluded that topical TiF4 application may be effective in prevention of dental erosion caused by hydrochloric acid from the stomach in patients with frequent vomiting or gastroesophageal reflux.
Chemical agents for the control of plaque and plaque microflora: an overview
Authors: Gaffar A. , Afflitto J. , Nabi N.
Published: October 2007

This presentation provides an overview of the technologies available for the chemical control of plaque. It is generally accepted that the formation of dental plaque at the interfaces of tooth/gingiva is one of the major causes of gingival inflammation and dental caries. Several therapeutic approaches have been used to control dental plaque and supragingival infections. These include fluoride preparations such as stannous fluoride, oxygenating agents, anti‐attachment agents, and cationic and non‐cationic antibacterial agents. Among the fluoride preparations, stable stannous fluoride pastes and gels have been shown to reduce supragingival plaque, gingivitis, hypersensitivity and caries. The effect of the oxygenating agents on the supragingival plaque has been equivocal, but recent data indicate that a stable agent which provides sustained active oxygen release is effective in controlling plaque. A polymer, PVPA, which reduced attachment of bacteria to teeth was shown to significantly reduce plaque formation in humans. A new generation of antibacterials includes nonionics such as triclosan, which in combination with a special polymer delivery system, has been shown to reduce plaque, gingivitis, supragingival calculus and dental caries in long‐term studies conducted around the world. Unlike the first generation of agents, the triclosan/copolymer/sodium fluoride system is effective in long‐term clinicals and does not cause staining of teeth, increase in calculus, or disturbance in the oral microbial ecology.
Breath odor: etiopathogenesis, assessment and management
Authors: Scully Crispian , El‐Maaytah Mohamed , Porter Stephen R , Greenman John
Published: October 2007

Oral malodor is a significant social disability which usually has a local cause, particularly arising from the oral flora. Malodor may arise from the lingual or periodontal flora, gram‐negative anaerobes being the main organisms capable of releasing sulphur compounds, from the putrefaction of debris and other material. Volatile sulphur compounds, cadaverine and other substances appear responsible for much of the malodor. Systemic disease may underlie some cases of oral malodor. The objective assessment of malodor is still best performed by the human sense of smell (organoleptic method) but more quantifiable measures are being developed.
Masticatory muscle function after unilateral condylar fractures: a prospective and quantitative electromyographic study
Authors: Hjorth T. , Melsen B. , Møller E.
Published: October 2007

Electromyographic (EMG) recording of masticatory muscle activity was performed in 9 adult men with unilateral condylar fracture immediately after conservative treatment of the condylar fracture (TO) and 4 (T1) and 8 (T2) months after the trauma. From TO to T2, maximal voluntary contraction of the anterior and posterior temporal muscles and of the masseter muscle opposite the fracture side (contralateral) increased significantly. Activity in the anterior temporal muscles also rose significantly during natural chewing, whereas the masseter muscles remained at the same level, but activity consistently tended to be strongest contralaterally to the condylar fracture. In addition, there was a tendency from T1 to T2 for natural chewing to take place predominantly on the contralateral side. The most obvious overall changes during the follow‐up were shorter and stronger contractions in all muscles during chewing, on the side of the impaired joint. The increase of activity in the anterior temporal muscles during maximal bite and natural chewing, and the occurrence of stronger and shorter contractions during ipsilateral chewing, were interpreted as signs of improved function due to healing and relief of pain from the impaired joint. On the other hand, there was a specific rise of maximal activity only in the contralateral masseter. and during natural chewing, activity was constantly stronger in the same muscle in combination with the tendency of increasing predominance of contralateral strokes. These traits specificly related to the masseter muscles were considered an indication of a permanent functional distortion due to reflex suppression on the fracture side as an after‐effect of the injury.
Mineralized nodule formation by human dental papilla cells in culture
Authors: Jianjun Hao , Junnan Shi , Zhongying Nlu , Wenxing Xum , Ling Yue , Mingzhen Xiao
Published: October 2007

Human dental papilla cells were enzymatically separated from deciduous tooth germs of an 8‐month‐old embryo legally aborted. the second passage cells were cultured up to 35 days in 3 groups. The β‐gp group was cultured in the Dulbecco MEM containing ascorbic acie and β‐glycerophosphate supplemented with 15% fetal bovine serum. The Dex group was in the same medium, in addition containing dexamethasone. The Control group contained none of the 3 chemicals, Mineralized nodules were formed after 15 days in the β‐GP and Dex groups. Only in the presence of ascorbic acid and organic phosphate did they mineralize. The addition of dexamethasone caused a significant increase in the number of nodules. By electron microscopy, the nodules contained needle‐shaped crystals associated with a network of collagen fibrils. Calcium and phosphorus were detected by energy‐dispersive X‐ray diffiractometry. Cells showed high levels of alkaline phosphatase activity, which was increased 2∼3 times in the presence of the 3 chemicals. These results indicated that human dental papilla cells have the ability to from dentin in culture. The formation of mineralized nodules by human dental papilla in vitro provides a useful model for studying the morphogenesis and differentiation of dental papilla cctomesenchyme.
Expression of BMP‐2 and TGF‐β1 mRNA during healing of the rabbit mandible
Authors: Si Xiaohui , Jin Yan , Yang Lianjia , Tipoe Geirge L. , White Frank H.
Published: October 2007

To identify the cell types which produce BMP and TGF‐β during fracture healing and to elucidate the interactions between BMP and TGF‐β in regulating cell proliferation and differeentiation at various stages, an experimental model of fracture healing in the rabbit mandible was established and the expression of BMP‐2 and TGF‐β1 mRNA was studied at different healing stages by in situ hybridization. The results showed that undifferentiated mesenchymal cells, differentiating osteoblasts and chondroblasts, had higher levels of BMP‐2 mRNA at the stage of intramembranous bone formation and early chondrogenesis, while the level of TGF‐β1 mRNA expression was closely associated with the active synthetic stage of osteoblasts and chondrocytes. These obserbvations suggest that both BMP and TGF‐β are involved in the regulation of fracture healing, BMP may play an important role in bone induction and early chondrogenesis, while TGF‐β regulates the proliferation and active synthetic ability of chondrocytes and osteoblasts.
Pseudophacidium garmanii n.sp., on interior spruce in British Columbia
Authors: Funk A.
Published: October 2007

A new species, Pseudophacidium garmanii (Ascomycetes: Phacidiales), is described from interior spruce (Picea glauca (Moench) Voss and P. engelmannii Parry) in British Columbia, Canada. The anamorph is a Myxofusicoccum, but sometimes the apothecia are also partly or entirely conidial.
Etude structurale, fonctionnelle et métabolique du méristème apical jeune de l’Isoetes setacea
Authors: Michaux-Ferrière Nicole
Published: October 2007

The apical meristem of Isoetes setacea Lam. is morphologically and cytologically individualized after the third plastochron. Compared with the adult, the young meristem is characterized by reduced dimensions and the absence of structural and functional zonation. In these young meristems, cells have a very fast RNA turnover and a short cell cycle in which the presynthesis phase, G1, is preponderant. No cells exhibiting morphological, cytological, or metabolical characters typical of filicinean apical cells have been recognized.
La végétation des combes à neige du golfe de Richmond, Québec nordique
Authors: Morin Hubert , Payette Serge
Published: October 2007

An exhaustive survey of snow patches, along an altitudinal gradient situated in an area of about 10 km2 along the Hudson Bay highlands, underlines the role of altitude, exposition, and topography in maintaining these habitats. The principal component analysis from a stratified sampling of the snow patches in the three cuesta lithological zones (arkose, dolomite, and basalt) stresses the effect of the snow melt gradient on species distribution within a snow patch. The ordination of abiotic variables performed on the ordination frame of snow patches shows that lithology and substratum are the principal factors responsible for the vegetation characteristics, allowing the determination of two main types of snow patches in the arkose and dolomite zones and three types in the basalt zone.
Questieriella quercina n. sp. and notes on an additional collection of Schiffnerula oyedaeae
Authors: Hughes S. J.
Published: October 2007

Questieriella quercina n. sp. is illustrated and described on leaves of Quercus sp. from Costa Rica. Sydow's Fungi exotici exsiccati 857 sub Schiffnerula compositarum is assigned to S. oyedaeae.
A study of morphological variation in Pseudotsuga menziesii in southwestern British Columbia
Authors: Chen Zhong-Yi , Scagel R. K. , Maze Jack
Published: October 2007

Variation in needle and twig anatomy for 46 populations of Pseudotsuga menziesii was apportioned into that due to (i) taxonomic structure (the variety menziesii from coastal areas, the variety glauca from east of the Cascade crest, and intermediates from intervening areas); (ii) populations; and (iii) individual trees within populations. The variation was classified on the basis of summary variables, the principal components resulting from principal components analysis. Principal components analysis was performed both on original needle and twig variables and on residuals from multiple regression analysis of elevation, latitude, and longitude. The analysis of residuals removes the effect of allopatry and macroclimate. In both analyses, the smallest source of variation was taxonomic structure while most of the variation occurred within populations, suggesting that recognition of subspecific taxa in this portion of the geographic range is not appropriate. The results of analyses of original variables and residuals were highly correlated, indicating that relationships between individuals are not the result of allopatry or selection due to macroclimate. The observation that individuals account for most of the variation in the data is interpreted as indicating that the production of individual variants is a more significant evolutionary event than population differentiation.
Localization of polyphenol oxidase activity in the lamellae and membrane-bound inclusions of etiolated soybean hypocotyl chloroplasts
Authors: Lazarovits G. , Singh B.
Published: October 2007

Localization for polyphenol oxidase was carried out on 6-day-old etiolated soybean (Glycine max (L.) Merr.) tissue. Light and electron microscope observations of tissues exposed to the substrate L-dihydroxyphenylalanine after chemical fixation revealed that polyphenol oxidase activity was present in the lamellae and membrane-bound inclusions of chloroplasts. Inhibitors of polyphenol oxidase, diethyldithiocarbamate and phenylhydrazine, prevented formation of the reaction product. Only plastids in epidermal and associated cortex collenchyma cell layers contained inclusions and enzyme activity. Most guard cells and all cortex parenchyma cells were devoid of both. Homogenates of epidermal strips were shown to contain 95–99% of the total polyphenol oxidase activity present in hypocotyls.
Discochora yuccae sp. nov. with Phyllosticta and Leptodothiorella synanamorphs
Authors: Bissett John
Published: October 2007

Discochora yuccae sp. nov. and its conidial anamorph Phyllosticta yuccae sp. nov. and spermatial synanamorph Leptodothiorella notabilis Petrak & Ciferri are described. The fungus causes a leaf-blotch disease of Yucca spp. and is distinguished by the long, cylindrical asci and relatively large, ellipsoidal ascospores. New combinations in Discochora are made for nine species previously assigned to Guignardia (auct.) and occurring on Liliales. One new combination is made in Botryosphaeria.
Taxonomy of the North and South American species of Hordeum section Hordeastrum
Authors: Baum Bernard R. , Bailey L. Grant
Published: October 2007

The four species H. euclaston Steud., H. flexuosum Nees ex Steud., H. intercedens Nevski, and H. pusillum Nutt. have been regarded as conspecific by some authors, because of a lack of markers for distinguishing among the species. Bothmer and co-workers recently recognized the four species but were unable to demonstrate morphological discontinuities that could be used in keys to permit definite identification to species. This paper provides new evidence from lodicule and epiblast characters for existence of four species. A key based on the rachilla, lodicules, and epiblast is presented. Furthermore, carefully defined morphometric characters of the four species were analysed by various discriminant analyses techniques. These analyses confirm the recognition of four morphological species and enable identification by means of resulting discriminant functions in addition to and complementary to the key.
Some Ramaria taxa from Nova Scotia
Authors: Petersen Ronald H.
Published: October 2007

Several taxa of Ramaria subgenera Ramaria and Laeticolora are described from herbarium specimens and material collected in Nova Scotia. Distribution patterns of the taxa are discussed, and taxa are compared with extralimital organisms. Proposed new taxa are, in subg. Ramaria, R. cinereocarnea, R. daucipes, and R. zeppelinospora; and in subg. Laeticolora, R. neoformosa var. macrospora, R. aenea, R. somniculosa, R. primulina, R. grundii, and R. harrisonii. Ramaria rubripermanens var. longissimispora stat. nov. and R. subtilis stat. nov. are also proposed.
Competition and niche separation in Sphagnum
Authors: Rydin Håkan
Published: October 2007

In bogs in eastern Sweden there are usually three, four, or five species of Sphagnum occurring along the gradient from hummock to hollow in the order S. fuscum, S. rubellum, S. balticum, S. tenellum, and S. cuspidatum. Transect studies revealed that, in some cases, the distribution of the species along the gradient was affected by the species composition in the transect. These cases were interpreted as niche shifts, indicating that some species are replaced at their lower limit by a superior competitor. Results from field experiments, in which the species were grown in different combinations at different heights above the water table, were not always in agreement with the transect studies. For example, the experiments gave only partial evidence of S. rubellum replacing S. fuscum and no evidence of S. tenellum replacing S. balticum. In these cases, priority of colonization may be more important than competition.
Association of Parkerella populi with declining hybrid aspen in Wisconsin
Authors: Ostry Michael E.
Published: October 2007

Parkerella populi Funk was found for the first time in the United States on hybrid aspen in two test plantings in Wisconsin. Parkerella populi was associated only with declining trees of a triploid Populus tremuloides Michx. × P. tremula L. hybrid. Parkerella populi was the only fungus found associated with deeply fissured, black bark of the declining trees. Adjacent trees of different clones were not affected in either plantation. These observations suggest, therefore, that P. populi may have been a primary pathogen of these hybrids.
LINEAR BENDING ANALYSIS OF INHOMOGENEOUS VARIABLE-THICKNESS ORTHOTROPIC PLATES UNDER VARIOUS BOUNDARY CONDITIONS
Authors: ZENKOUR A. M. , ALLAM M. N. M. , MASHAT D. S.
Published: October 2007

An exact solution to the bending of variable-thickness orthotropic plates is developed for a variety of boundary conditions. The procedure, based on a Lévy-type solution considered in conjunction with the state-space concept, is applicable to inhomogeneous variable-thickness rectangular plates with two opposite edges simply supported. The remaining ones are subjected to a combination of clamped, simply supported, and free boundary conditions, and between these two edges the plate may have varying thickness. The procedure is valuable in view of the fact that tables of deflections and stresses cannot be presented for inhomogeneous variable-thickness plates as for isotropic homogeneous plates even for commonly encountered loads because the results depend on the inhomogeneity coefficient and the orthotropic material properties instead of a single flexural rigidity. Benchmark numerical results, useful for the validation or otherwise of approximate solutions, are tabulated. The influences of the degree of inhomogeneity, aspect ratio, thickness parameter, and the degree of nonuniformity on the deflections and stresses are investigated.
AMERICA'S LARGEST BLACK-OWNED COMPANIES: A 30-YEAR LONGITUDINAL ANALYSIS
Authors: SONFIELD MATTHEW C.
Published: October 2007

This article investigates the largest American black-owned companies over a 30-year period, from 1974 to 2004. Trends with regard to the growth and decline of industry categories and of individual companies, and with regard to these companies' survival rates, are analyzed. Comparable survival rates of small businesses in general, of minority businesses, and of large corporations are investigated. The important factors of corporate minority procurement programs and government minority set-aside programs are evaluated. The phenomenon of large American corporations acquiring some of the most successful black-owned businesses is also studied. These various factors relating to black business success and failure lead to a range of implications and recommendations for current and aspiring minority business owners, as well as to consultants to and researchers of minority business.
A SIMULATED ANNEALING ALGORITHM FOR SYSTEM-ON-CHIP TEST SCHEDULING WITH, POWER AND PRECEDENCE CONSTRAINTS
Authors: HARMANANI HAIDAR M. , SALAMY HASSAN A.
Published: October 2007

This paper presents an efficient method to determine minimum system-on-chip (SOC) test schedules with precedence and power constraints based on simulated annealing. The problem is solved using a partitioned testing scheme with run to completion that minimizes the number of idle test slots. The method can handle SOC test scheduling with and without power constraints in addition to precedence constraints that preserve desirable orderings among tests. We present experimental results for various SOC examples that demonstrate the effectiveness of the method. The method achieved optimal test schedules in all attempted cases in a short CPU time.
PROTEIN SECONDARY STRUCTURE PREDICTION USING SUPPORT VECTOR MACHINES AND A NEW FEATURE REPRESENTATION
Authors: GUBBI JAYAVARDHANA , LAI DANIEL T. H. , PALANISWAMI MARIMUTHU , PARKER MICHAEL
Published: October 2007

Knowledge of the secondary structure and solvent accessibility of a protein plays a vital role in the prediction of fold, and eventually the tertiary structure of the protein. A challenging issue of predicting protein secondary structure from sequence alone is addressed. Support vector machines (SVM) are employed for the classification and the SVM outputs are converted to posterior probabilities for multi-class classification. The effect of using Chou–Fasman parameters and physico-chemical parameters along with evolutionary information in the form of position specific scoring matrix (PSSM) is analyzed. These proposed methods are tested on the RS126 and CB513 datasets. A new dataset is curated (PSS504) using recent release of CATH. On the CB513 dataset, sevenfold cross-validation accuracy of 77.9% was obtained using the proposed encoding method. A new method of calculating the reliability index based on the number of votes and the Support Vector Machine decision value is also proposed. A blind test on the EVA dataset gives an average Q3accuracy of 74.5% and ranks in top five protein structure prediction methods. Supplementary material including datasets are available on .
SYSTEMATIC DESIGN PROCEDURE OF TS-TYPE FUZZY CONTROLLERS
Authors: SOUKKOU A. , KHELLAF A. , LEULMI S.
Published: October 2007

This paper contributes a new alternative for the synthesis of Takagi–Sugeno fuzzy logic controller with reduced rule base. A Genetic Approach to Fuzzy Supervised Learning algorithm called GAFSL based on the Multiobjective Genetic Algorithms (MGAs) is used to construct the proposed robust fuzzy controller. The result controller is similar to nonlinear PI/PD controllers. The tuning algorithm cannot only tune the scaling factors, the shapes of membership functions, and the consequent values, but also optimize the number of rules as possible with guaranteed desired performances: accuracy and robustness. The construction of the chromosomes is based on the mixed binary–real coding system. The genes of chromosome are arranged into two parts, the first part contains the control genes (the certainty factors) and the second part contains the parameters genes that represent the fuzzy knowledge base. The concept of elite strategy is adopted, where the best individuals in a population are regarded as elites. Computer simulation results on two nonlinear problems that are derived to demonstrate the powerful GAFSL algorithm.
Antitumor and Antivascular Effects of AVE8062 in Ovarian Carcinoma
Authors: Kim Tae Jin , Ravoori Murali , Landen Charles N. , Kamat Aparna A. , Han Liz Y. , Lu Chunhua , Lin Yvonne G. , Merritt William M. , Jennings Nicholas , Spannuth Whitney A. , Langley Robert , Gershenson David M. , Coleman Robert L. , Kundra Vikas , Sood Anil K.
Published: October 2007

The purpose of this study was to examine the therapeutic efficacy and underlying mechanisms of action of a vascular-disrupting agent, AVE8062, and to determine its effects on tumor metabolic activity. The in vitro and in vivo effects of AVE8062 alone and in combination with docetaxel were tested in chemotherapy-sensitive and chemotherapy-resistant ovarian cancer models. Tumors were analyzed for necrosis, microvessel density, endothelial cell apoptosis, and proliferation following treatment. The effect of AVE8062 on tumor regression and metabolic activity was examined by magnetic resonance (MR) or by [18F]fluorodeoxyglucose ([18F]FDG) uptake by positron emission tomography (PET) with MR imaging, respectively. AVE8062 monotherapy was effective in inhibiting tumor growth in all models (range 43–51% versus control; P < 0.05). Combination therapy was even more effective in inhibiting tumor growth (range 76–90% compared with controls, P < 0.01). AVE8062 in combination with chemotherapy significantly prolonged survival in HeyA8-injected mice (P < 0.001) compared with other groups. AVE8062-based therapy resulted in rapid development of central tumor necrosis, decreased microvessel density, decreased proliferation, and induction of apoptosis of tumor-associated endothelial cells. MR imaging showed regression of established HeyA8 ovarian tumors and [18F]FDG PET with MR showed rapid decrease in metabolic activity after AVE8062 therapy. Combination of AVE8062 plus docetaxel results in potent inhibition of ovarian cancer growth. These results suggest that AVE8062 may be useful as a clinical therapeutic approach for ovarian cancer patients and that functional [18F]FDG PET imaging may predict clinical response before an anatomic reduction in tumor size. [Cancer Res 2007;67(19):9337–45]