FEASIBILITY OF MICRONUCLEUS METHODS FOR MONITORING GENETIC DAMAGE IN TWO FERAL SPECIES OF SMALL MAMMALS

EPA Science Inventory

Peromyscus leucopus (white-footed mouse) and Cryptotis parva (least shrew) possess desirable attributes for biomonitoring contamination of terrestrial ecoystems, but few studies have examined the potential use of these species for monitoring exposure to genotoxic contaminants. Th...

Can texture analysis of tooth microwear detect within guild niche partitioning in extinct species?

NASA Astrophysics Data System (ADS)

Purnell, Mark; Nedza, Christopher; Rychlik, Leszek

2017-04-01

Recent work shows that tooth microwear analysis can be applied further back in time and deeper into the phylogenetic history of vertebrate clades than previously thought (e.g. niche partitioning in early Jurassic insectivorous mammals; Gill et al., 2014, Nature). Furthermore, quantitative approaches to analysis based on parameterization of surface roughness are increasing the robustness and repeatability of this widely used dietary proxy. Discriminating between taxa within dietary guilds has the potential to significantly increase our ability to determine resource use and partitioning in fossil vertebrates, but how sensitive is the technique? To address this question we analysed tooth microwear texture in sympatric populations of shrew species (Neomys fodiens, Neomys anomalus, Sorex araneus, Sorex minutus) from BiaŁ owieza Forest, Poland. These populations are known to exhibit varying degrees of niche partitioning (Churchfield & Rychlik, 2006, J. Zool.) with greatest overlap between the Neomys species. Sorex araneus also exhibits some niche overlap with N. anomalus, while S. minutus is the most specialised. Multivariate analysis based only on tooth microwear textures recovers the same pattern of niche partitioning. Our results also suggest that tooth textures track seasonal differences in diet. Projecting data from fossils into the multivariate dietary space defined using microwear from extant taxa demonstrates that the technique is capable of subtle dietary discrimination in extinct insectivores.

Neotrombicula autumnalis (Acari, Trombiculidae) as a vector for Borrelia burgdorferi sensu lato?

PubMed

Kampen, H; Schöler, A; Metzen, M; Oehme, R; Hartelt, K; Kimmig, P; Maier, W A

2004-01-01

Larvae of the trombiculid mite Neotrombicula autumnalis were collected at 18 sites in and around Bonn, Germany, to be screened for infection with Borrelia burgdorferi s.l. by means of PCR. Questing larvae numbering 1380 were derived from the vegetation and 634 feeding ones were removed from 100 trapped micromammals including voles, mice, shrews and hedgehogs. In a laboratory infection experiment, a further 305 host-seeking larvae from the field were transferred onto Borrelia-positive mice and gerbils, and examined for spirochete infection at various intervals after repletion. In three cases borrelial DNA could be amplified from the mites: (1) from a larva feeding on a wild-caught greater white-toothed shrew (Crocidura russula), (2) from a pool of four larvae feeding on a B. garinii-positive laboratory mouse, and (3) from a nymph that had fed on a B. afzelii-positive laboratory gerbil as a larva. In the first case, borrelial species determination by DNA hybridization of the PCR product was only possible with a B. burgdorferi complex-specific probe but not with a species-specific one. In the second case, probing showed the same borrelial genospecies (B. garinii) as the laboratory host had been infected with. In the latter case, however, DNA hybridization demonstrated B. valaisiana while the laboratory host had been infected with B. afzelii. Subsequent DNA sequencing confirmed much higher similarity of the PCR product to B. valaisiana than to B. afzelii indicating an infection of the mite prior to feeding on the laboratory host. The negligible percentage of positive mites found in this study suggests that either the uptake of borrelial cells by feeding trombiculids is an extremely rare event or that ingested spirochetes are rapidly digested. On the other hand, the results imply a possible transstadial and transovarial transmission of borreliae once they are established in their trombiculid host. However, unless the transmission of borreliae to a given host is demonstrated, a final statement on the vector competence of trombiculid mites is not possible.

Habitat used by shrews in southeastern Montana

Treesearch

James G. MacCracken; Daniel W. Uresk; Richard M. Hansen

1985-01-01

Dwarf shrews (Sorex nanus), masked shrews (Sorex cinereus), and Merriam shrews (Sorex merriami) were most abundant in riparian and sagebrush-grass habitat types in southeastern Montana. Litter cover was greater in areas occupied by shrews than in areas without shrews. Microhabitat humidity, as related to litter...

Passage of infectious nuclear polyhedrosis virus through the alimentary tracts of two small mammal predators of the gypsy moth, Lymantria dispar

Treesearch

R.A. Lautenschlager; J.D. Podgwaite

1977-01-01

The white-footed mouse, Peromyscus leucopus Rafinesque, and the short-tailed shrew, Blarina brevicauda Say, 2 small mammal predators of the gypsy moth, have demonstrated the ability to pass significant amounts of infectious nuclear polyhedrosis virus (NPV) through their alimentary tracts. Ninety-five percent of the gypsy moth...

Effect of Nucleopolyhedrosis Virus on Selected Mammalian Predators of the Gypsy Moth

Treesearch

R.A. Lautenschlager; C.H. Kircher; J.D. Podgwaite

1977-01-01

Nucleopolyhedrosis virus (NPV) of the gypsy moth was fed to three mammalian predators of the insect: the white-footed mouse, the short-tailed shrew, and the Virginia opposum in the form of NPV-infected 5th instar gypsy moth larvae, polyhedral inclusion bodies (PIB's) mixed in dog food and PIB's mixed in a standard spray formulation. The total amount of NPV...

Passage of nucleopolyhedrosis virus by avian and mammalian predators of the gypsy moth, Lymantria dispar

Treesearch

R.A. Lautenschlager; J.D. Podgwaite

1979-01-01

Five species of mammals and 3 species of birds passed polyhedral inclusion bodies (PIB) of the gypsy moth nucleopolyhedrosis virus (NPV) through their alimentary tracts in amounts great enough to kIll gypsy moth larvae. In bioassays. Opossums and raccoons passed roughly 5% of the PIB administered by intubation while white-footed mice, a short-tailed shrew, and southern...

A novel male-associated marker for sex identification in Ussuri catfish Pseudobagrus ussuriensis

NASA Astrophysics Data System (ADS)

Zhu, Chuankun; Pan, Zhengjun; Wang, Hui; Chang, Guoliang; Ding, Huaiyu

2017-08-01

The Ussuri catfish Pseudobagrus ussuriensis is a promising aquaculture fish with sexual dimorphism that males grow 2-3 times faster than females. Therefore, all-male breeding could increase production of this fish, and sex-linked markers would be useful during the breeding process. In this study, a male-associated marker named PuGT54 was isolated in P. ussuriensis from a previously constructed microsatellite library. A total of 185 P. ussuriensis individuals containing 95 females and 90 males were used to test the usage of this maker. And results showed that sexes of all individuals were successfully identified, indicating the high reliability and accuracy of this marker for sex identification. Furthermore, the male-specific fragment amplified by this maker was cloned and sequenced, which was 118 base pairs in length. As homologous genes of this fragment was not found through BLASTn, detailed information of the male-specific fragment is unknown presently. Nevertheless, this marker would be helpful in conservation, breeding and ecological study of P. ussuriensis.

Contiguous allopatry of the masked shrew and southeastern shrew in the Southern Appalachians: segregation along an elevational and habitat gradient

Treesearch

W. Mark Ford; Michael A. Menzel; Timothy S. McCay; Joshua Laerm

2001-01-01

Southeastern shrew. (Sorex longirostris) and masked shrew (Sorex cinereus) distributions converge in the Southern Appalachians. A 306,454-pitfall--trapnight survey in Alabama, Georgia, North Carolina, and South Carolina doc-umented the presence of southeastern shrews in the Cumberland Plateau, Ridge and Valley, Upper Piedmont, and...

Identification of the full-length β-actin sequence and expression profiles in the tree shrew (Tupaia belangeri).

PubMed

Zheng, Yu; Yun, Chenxia; Wang, Qihui; Smith, Wanli W; Leng, Jing

2015-02-01

The tree shrew (Tupaia belangeri) diverges from the primate order (Primates) and is classified as a separate taxonomic group of mammals - Scandentia. It has been suggested that the tree shrew can be used as an animal model for studying human diseases; however, the genomic sequence of the tree shrew is largely unidentified. In the present study, we reported the full-length cDNA sequence of the housekeeping gene, β-actin, in the tree shrew. The amino acid sequence of β-actin in the tree shrew was compared to that of humans and other species; a simple phylogenetic relationship was discovered. Quantitative polymerase chain reaction (qPCR) and western blot analysis further demonstrated that the expression profiles of β-actin, as a general conservative housekeeping gene, in the tree shrew were similar to those in humans, although the expression levels varied among different types of tissue in the tree shrew. Our data provide evidence that the tree shrew has a close phylogenetic association with humans. These findings further enhance the potential that the tree shrew, as a species, may be used as an animal model for studying human disorders.

The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias.

PubMed

French, G C A; Stürup, M; Rizzuto, S; van Wyk, J H; Edwards, D; Dolan, R W; Wintner, S P; Towner, A V; Hughes, W O H

2017-10-01

Results from this study of the white shark Carcharodon carcharias include measurements obtained using a novel photographic method that reveal significant differences between the sexes in the relationship between tooth cuspidity and shark total length, and a novel ontogenetic change in male tooth shape. Males exhibit broader upper first teeth and increased distal inclination of upper third teeth with increasing length, while females do not present a consistent morphological change. Substantial individual variation, with implications for pace of life syndrome, was present in males and tooth polymorphism was suggested in females. Sexual differences and individual variation may play major roles in ontogenetic changes in tooth morphology in C. carcharias, with potential implications for their foraging biology. Such individual and sexual differences should be included in studies of ontogenetic shift dynamics in other species and systems. © 2017 The Fisheries Society of the British Isles.

Does shape co-variation between the skull and the mandible have functional consequences? A 3D approach for a 3D problem

PubMed Central

Cornette, Raphaël; Baylac, Michel; Souter, Thibaud; Herrel, Anthony

2013-01-01

Morpho-functional patterns are important drivers of phenotypic diversity given their importance in a fitness-related context. Although modularity of the mandible and skull has been studied extensively in mammals, few studies have explored shape co-variation between these two structures. Despite being developmentally independent, the skull and mandible form a functionally integrated unit. In the present paper we use 3D surface geometric morphometric methods allowing us to explore the form of both skull and mandible in its 3D complexity using the greater white-toothed shrew as a model. This approach allows an accurate 3D description of zones devoid of anatomical landmarks that are functionally important. Two-block partial least-squares approaches were used to describe the co-variation of form between skull and mandible. Moreover, a 3D biomechanical model was used to explore the functional consequences of the observed patterns of co-variation. Our results show the efficiency of the method in investigations of complex morpho-functional patterns. Indeed, the description of shape co-variation between the skull and the mandible highlighted the location and the intensity of their functional relationships through the jaw adductor muscles linking these two structures. Our results also demonstrated that shape co-variation in form between the skull and mandible has direct functional consequences on the recruitment of muscles during biting. PMID:23964811

Aspects of masticatory form and function in common tree shrews, Tupaia glis.

PubMed

Fish, D R

1983-04-01

Tree shrews have relatively primitive tribosphenic molars that are apparently similar to those of basal eutherians; thus, these animals have been used as a model to describe mastication in early mammals. In this study the gross morphology of the bony skull, joints, dentition, and muscles of mastication are related to potential jaw movements and cuspal relationships. Potential for complex mandibular movements is indicated by a mobile mandibular symphysis, shallow mandibular fossa that is large compared to its resident condyle, and relatively loose temporomandibular joint ligaments. Abrasive tooth wear is noticeable, and is most marked at the first molars and buccal aspects of the upper cheek teeth distal to P2. Muscle morphology is basically similar to that previously described for Tupaia minor and Ptilocercus lowii. However, in T. glis, an intraorbital part of deep temporalis has the potential for inducing lingual translation of its dentary, and the large medial pterygoid has extended its origin anteriorly to the floor of the orbit, which would enhance protrusion. The importance of the tongue and hyoid muscles during mastication is suggested by broadly expanded anterior bellies of digastrics, which may assist mylohyoids in tensing the floor of the mouth during forceful tongue actions, and by preliminary electromyography, which suggests that masticatory muscles alone cannot fully account for jaw movements in this species.

Short-tailed shrews: Toxicity and residue relationships of DDT, dieldrin, and endrin

USGS Publications Warehouse

Blus, L.J.

1978-01-01

Experiments involving dietary toxicity and residue relationships of DDT, dieldrin, and endrin were conducted with short-tailed shrews. Dietary concentrations of DDT dissolved in vegetable oils were usually more toxic than diets containing comparable amounts of powdered DDT. Younger shrews, particularly females, were more tolerant of powdered DDT than older animals; yet, there were no conspicuous age differences in toxicity of DDT dissolved in oils. In comparison to other mammals, short-tailed shrews are not unusually sensitive to DDT, dieldrin, or endrin on the basis of two-week feeding tests. The influence of age and sex on toxicity of DDT, endrin, and dieldrin was sometimes more important than body weight. Of those shrews of the same age and sex that were fed the same dietary dosage, heavier shrews were more tolerant than lighter individuals; and, heavier shrews tended to lose a greater percentage of body weight before death. There was a range of 15 to 105 DDT equivalents in brains of shrews dying on dietary dosages of DDT. Six shrews fed a high level of DDT seemed to have unusual metabolite capabilities and died with apparent lethal levels of DDD in their brains. Levels of dieldrin in brains of shrews that died on a dietary dosage of dieldrin ranged from 3.7 to 12.6 ppm. In the rates of gain and loss experiments where shrews were given diets containing 400 ppm DDT or 50 ppm dieldrin up to 17 days, high residues were noted in tissues of shrews after two weeks on a contaminated diet and a few died at that time. After shrews were placed on clean food, it was determined that >50% of the dieldrin residues in carcass and brain were lost in 50% of residues of DDT and metabolites in brains after 2 weeks on clean food; males lost nearly 50% of residues in carcasses after two weeks on clean food compared with a loss of only 11% in females.

Effect of four over-the-counter tooth-whitening products on enamel microhardness.

PubMed

Majeed, A; Grobler, S R; Moola, M H; Oberholzer, T G

2011-10-01

This in vitro study evaluated the effect of four over-the-counter tooth-whitening products on enamel microhardness. Fifty enamel blocks were prepared from extracted human molar teeth. The enamel surfaces were polished up to 1200 grit fineness and the specimens randomly divided into five groups. Enamel blocks were exposed to: Rapid White (n=10); Absolute White (n=10); Speed White (n=10) and White Glo (n=10) whitening products, according to the manufacturers' instructions. As control, ten enamel blocks were kept in artificial saliva at 37 degrees C without any treatment. Microhardness values were obtained before exposure (baseline) and after 1, 7 and 14-day treatment periods using a digital hardness tester with a Vickers diamond indenter. Data were analysed using Wilcoxon Signed Rank Sum Test, one-way ANOVA and Tukey-Kramer Multiple Comparison Test (p<0.05). Both Rapid White and Absolute White reduced enamel microhardness. Speed White increased the microhardness of enamel, while White Glo and artificial saliva had no effect on hardness. Over-the-counter tooth-whitening products might decrease enamel microhardness depending on the type of product.

Herpes Simplex Virus 1 Infection of Tree Shrews Differs from That of Mice in the Severity of Acute Infection and Viral Transcription in the Peripheral Nervous System

PubMed Central

Li, Lihong; Li, Zhuoran; Wang, Erlin; Yang, Rui; Xiao, Yu; Han, Hongbo; Lang, Fengchao; Li, Xin; Xia, Yujie; Gao, Feng; Li, Qihan; Fraser, Nigel W.

2015-01-01

ABSTRACT Studies of herpes simplex virus (HSV) infections of humans are limited by the use of rodent models such as mice, rabbits, and guinea pigs. Tree shrews (Tupaia belangeri chinensis) are small mammals indigenous to southwest Asia. At behavioral, anatomical, genomic, and evolutionary levels, tree shrews are much closer to primates than rodents are, and tree shrews are susceptible to HSV infection. Thus, we have studied herpes simplex virus 1 (HSV-1) infection in the tree shrew trigeminal ganglion (TG) following ocular inoculation. In situ hybridization, PCR, and quantitative reverse transcription-PCR (qRT-PCR) analyses confirm that HSV-1 latently infects neurons of the TG. When explant cocultivation of trigeminal ganglia was performed, the virus was recovered after 5 days of cocultivation with high efficiency. Swabbing the corneas of latently infected tree shrews revealed that tree shrews shed virus spontaneously at low frequencies. However, tree shrews differ significantly from mice in the expression of key HSV-1 genes, including ICP0, ICP4, and latency-associated transcript (LAT). In acutely infected tree shrew TGs, no level of ICP4 was observed, suggesting the absence of infection or a very weak, acute infection compared to that of the mouse. Immunofluorescence staining with ICP4 monoclonal antibody, and immunohistochemistry detection by HSV-1 polyclonal antibodies, showed a lack of viral proteins in tree shrew TGs during both acute and latent phases of infection. Cultivation of supernatant from homogenized, acutely infected TGs with RS1 cells also exhibited an absence of infectious HSV-1 from tree shrew TGs. We conclude that the tree shrew has an undetectable, or a much weaker, acute infection in the TGs. Interestingly, compared to mice, tree shrew TGs express high levels of ICP0 transcript in addition to LAT during latency. However, the ICP0 transcript remained nuclear, and no ICP0 protein could be seen during the course of mouse and tree shrew TG infections. Taken together, these observations suggest that the tree shrew TG infection differs significantly from the existing rodent models. IMPORTANCE Herpes simplex viruses (HSVs) establish lifelong infection in more than 80% of the human population, and their reactivation leads to oral and genital herpes. Currently, rodent models are the preferred models for latency studies. Rodents are distant from primates and may not fully represent human latency. The tree shrew is a small mammal, a prosimian primate, indigenous to southwest Asia. In an attempt to further develop the tree shrew as a useful model to study herpesvirus infection, we studied the establishment of latency and reactivation of HSV-1 in tree shrews following ocular inoculation. We found that the latent virus, which resides in the sensory neurons of the trigeminal ganglion, could be stress reactivated to produce infectious virus, following explant cocultivation and that spontaneous reactivation could be detected by cell culture of tears. Interestingly, the tree shrew model is quite different from the mouse model of HSV infection, in that the virus exhibited only a mild acute infection following inoculation with no detectable infectious virus from the sensory neurons. The mild infection may be more similar to human infection in that the sensory neurons continue to function after herpes reactivation and the affected skin tissue does not lose sensation. Our findings suggest that the tree shrew is a viable model to study HSV latency. PMID:26512084

Adoption of a nestling house mouse by a female short-tailed shrew

USGS Publications Warehouse

Blus, L.J.; Johnson, D.A.

1969-01-01

A nursing female short-tailed shrew adopted a nestling house mouse. The mouse was observed in the nest with the female and her litter of shrews three days after it was introduced into the aluminum box containing the shrews, but it was found dead in the nest four days later.

Chronic hepatitis B virus infection and occurrence of hepatocellular carcinoma in tree shrews (Tupaia belangeri chinensis).

PubMed

Yang, Chun; Ruan, Ping; Ou, Chao; Su, Jianjia; Cao, Ji; Luo, Chengpiao; Tang, Yanping; Wang, Qi; Qin, Hong; Sun, Wen; Li, Yuan

2015-02-13

Hepatitis B virus (HBV) infection has been believed as a major cause of hepatocellular carcinoma (HCC) for a long time, however, the evidences of which are mostly from clinical and epidemiological investigations while there is no evidence from animal experiments. Tree shrew (Tupaia) is a small animal closely related to primates evolutionarily, with about 8 years of lifespan. Our previous study proved that tree shrews can be chronically HBV-infected after being inoculated neonatally with HBV. The present study reports the further results from the longer-term observation of these animals. Neonatal tree shrews were inoculated with sera from HBV-infected patient or tree shrew. Their serum samples and liver biopsies were collected periodically for detection of HBV markers as well as for histopathological and immunohistochemical examinations. Group A consisted of six tree shrews with chronic HBV-infection, and group B consisted of nine tree shrews without chronic HBV infection. Periodical examinations on serum and liver biopsies of the animals in group A showed the progress of HBV infection, and two cases of HCC occurred at their late stage of life. The courses of HBV infection and the hepatic histopathological and immunohistochemical changes in the tree shrews were similar to those in humans. In contrast, neither HCC nor obvious hepatitis histopathological change was found among the tree shrews in group B. The course of HBV infection and the features of HCC discovered in tree shrews are similar to those of chronically HBV-infected humans. The tree shrew model might be used to investigate the underlying mechanisms favoring susceptibility for chronic HBV infection and disease progression.

[Analysis of the molecular characteristics and cloning of full-length coding sequence of interleukin-2 in tree shrews].

PubMed

Huang, Xiao-Yan; Li, Ming-Li; Xu, Juan; Gao, Yue-Dong; Wang, Wen-Guang; Yin, An-Guo; Li, Xiao-Fei; Sun, Xiao-Mei; Xia, Xue-Shan; Dai, Jie-Jie

2013-04-01

While the tree shrew (Tupaia belangeri chinensis) is an excellent animal model for studying the mechanisms of human diseases, but few studies examine interleukin-2 (IL-2), an important immune factor in disease model evaluation. In this study, a 465 bp of the full-length IL-2 cDNA encoding sequence was cloned from the RNA of tree shrew spleen lymphocytes, which were then cultivated and stimulated with ConA (concanavalin). Clustal W 2.0 was used to compare and analyze the sequence and molecular characteristics, and establish the similarity of the overall structure of IL-2 between tree shrews and other mammals. The homology of the IL-2 nucleotide sequence between tree shrews and humans was 93%, and the amino acid homology was 80%. The phylogenetic tree results, derived through the Neighbour-Joining method using MEGA5.0, indicated a close genetic relationship between tree shrews, Homo sapiens, and Macaca mulatta. The three-dimensional structure analysis showed that the surface charges in most regions of tree shrew IL-2 were similar to between tree shrews and humans; however, the N-glycosylation sites and local structures were different, which may affect antibody binding. These results provide a fundamental basis for the future study of IL-2 monoclonal antibody in tree shrews, thereby improving their utility as a model.

Tooth loss, systemic inflammation, and prevalent stroke among participants in the reasons for geographic and racial difference in stroke (REGARDS) study.

PubMed

You, Zhiying; Cushman, Mary; Jenny, Nancy S; Howard, George

2009-04-01

Periodontal disease results in tooth loss, may contribute to systemic inflammation, and is associated with stroke. We examined cross-sectional associations between tooth loss, inflammation markers, stroke, race, and geographic region among participants in the reasons for geographic and racial differences in stroke (REGARDS) study of whites and blacks > or =45 years. We studied 24,393 participants. Associations of tooth loss and inflammation markers (C-reactive protein (CRP), white blood cell count (WBC) and albumin) were examined by linear regression, and associations of tooth loss with geographic region, race, and prevalent stroke by logistic regression. Compared to whites, blacks had an odds ratio of 1.48 (95% confidence interval 1.37-1.60) of having more teeth lost. There were no geographic differences in tooth loss. Compared to no tooth loss, those with 17-32 teeth lost had 1.17mg/L higher CRP (p<0.0001) and 0.18x10(9)/L higher WBC (p=0.008), did not differ in albumin, and had an odds ratio of prevalent stroke of 1.28 (1.09-1.49). Those with 1-16 teeth lost did not differ in CRP and WBC, had 0.03g/dL higher albumin (p=0.004), and had no increased stroke prevalence. CRP or WBC did not attenuate associations between tooth loss and stroke. Tooth loss, which varied with race, but not region of residence, was associated with inflammation markers and stroke. The latter association was not confounded by inflammation markers.

Phylogenetic affinity of tree shrews to Glires is attributed to fast evolution rate.

PubMed

Lin, Jiannan; Chen, Guangfeng; Gu, Liang; Shen, Yuefeng; Zheng, Meizhu; Zheng, Weisheng; Hu, Xinjie; Zhang, Xiaobai; Qiu, Yu; Liu, Xiaoqing; Jiang, Cizhong

2014-02-01

Previous phylogenetic analyses have led to incongruent evolutionary relationships between tree shrews and other suborders of Euarchontoglires. What caused the incongruence remains elusive. In this study, we identified 6845 orthologous genes between seventeen placental mammals. Tree shrews and Primates were monophyletic in the phylogenetic trees derived from the first or/and second codon positions whereas tree shrews and Glires formed a monophyly in the trees derived from the third or all codon positions. The same topology was obtained in the phylogeny inference using the slowly and fast evolving genes, respectively. This incongruence was likely attributed to the fast substitution rate in tree shrews and Glires. Notably, sequence GC content only was not informative to resolve the controversial phylogenetic relationships between tree shrews, Glires, and Primates. Finally, estimation in the confidence of the tree selection strongly supported the phylogenetic affiliation of tree shrews to Primates as a monophyly. Copyright © 2013 Elsevier Inc. All rights reserved.

Creating animal models, why not use the Chinese tree shrew (Tupaia belangeri chinensis)?

PubMed

Yao, Yong-Gang

2017-05-18

The Chinese tree shrew ( Tupaia belangeri chinensis ), a squirrel-like and rat-sized mammal, has a wide distribution in Southeast Asia, South and Southwest China and has many unique characteristics that make it suitable for use as an experimental animal. There have been many studies using the tree shrew ( Tupaia belangeri ) aimed at increasing our understanding of fundamental biological mechanisms and for the modeling of human diseases and therapeutic responses. The recent release of a publicly available annotated genome sequence of the Chinese tree shrew and its genome database (www.treeshrewdb.org) has offered a solid base from which it is possible to elucidate the basic biological properties and create animal models using this species. The extensive characterization of key factors and signaling pathways in the immune and nervous systems has shown that tree shrews possess both conserved and unique features relative to primates. Hitherto, the tree shrew has been successfully used to create animal models for myopia, depression, breast cancer, alcohol-induced or non-alcoholic fatty liver diseases, herpes simplex virus type 1 (HSV-1) and hepatitis C virus (HCV) infections, to name a few. The recent successful genetic manipulation of the tree shrew has opened a new avenue for the wider usage of this animal in biomedical research. In this opinion paper, I attempt to summarize the recent research advances that have used the Chinese tree shrew, with a focus on the new knowledge obtained by using the biological properties identified using the tree shrew genome, a proposal for the genome-based approach for creating animal models, and the genetic manipulation of the tree shrew. With more studies using this species and the application of cutting-edge gene editing techniques, the tree shrew will continue to be under the spot light as a viable animal model for investigating the basis of many different human diseases.

Postglacial recolonization and Holocene diversification of Crocidura suaveolens (Mammalia, Soricidae) on the north-western fringe of the European continent

NASA Astrophysics Data System (ADS)

Rofes, Juan; Cucchi, Thomas; Hanot, Pauline; Herman, Jeremy; Stephan, Pierre; Cersoy, Sophie; Horáček, Ivan; Kerr, Elizabeth; Allberry, Kate; Valenzuela, Silvia; Zazzo, Antoine; Cornette, Raphaël; Tresset, Anne

2018-06-01

Phenotypic variation was characterized in 187 modern and archaeological specimens of the lesser white-toothed shrew (Crocidura suaveolens), obtained from both insular and continental European locations. Geometric morphometric methods were used to quantify variation in size and shape of the mandible. The phenotypic distance between populations, and the influence of several eco-geographical factors on the size and shape of the mandible in island populations, were assessed. Based on mandible shape divergence, the populations of C. suaveolens were clustered into continental, insular Atlantic and insular Mediterranean groups. Archaeological specimens from Molène Island, more than 3400 years old, display a mandible shape signal closer to that of the continental population than those of modern island populations. Conversely, the continental shape signals of the modern populations from Höedic and Sark suggest that these are relatively recent anthropogenic introductions. The populations of C. suaveolens from both the Atlantic and Mediterranean islands (except for Rouzic and Cyprus) show a significant increase in mandible size, compared to those from continental Europe. Significant phenotypic differences support the indigenous condition of C. suaveolens on most of the Atlantic islands, suggesting that the species arrived there before the separation of the Scilly Isles and Ushant from the continent due to the post-glacial rise in sea level. This provides an ante quem for its colonization of the north-western fringe of continental Europe, notwithstanding its absence from the region in the present day.

The Insect Eaters.

ERIC Educational Resources Information Center

Naturescope, 1986

1986-01-01

Presents information about insectivores, including definitions and characteristics of shrews, moles, hedgehogs, and tenrecs. Contains descriptions of the teaching activities "Little Starnose" and "You and a Shrew." A reproducible worksheet is provided for use in "You and a Shrew." (TW)

Mutualism between tree shrews and pitcher plants: perspectives and avenues for future research.

PubMed

Clarke, Charles; Moran, Jonathan A; Chin, Lijin

2010-10-01

Three species of Nepenthes pitcher plants from Borneo engage in a mutualistic interaction with mountain tree shrews, the basis of which is the exchange of nutritional resources. The plants produce modified "toilet pitchers" that produce copious amounts of exudates, the latter serving as a food source for tree shrews. The exudates are only accessible to the tree shrews when they position their hindquarters over the pitcher orifice. Tree shrews mark valuable resources with faeces and regularly defecate into the pitchers when they visit them to feed. Faeces represent a valuable source of nitrogen for these Nepenthes species, but there are many facets of the mutualism that are yet to be investigated. These include, but are not limited to, seasonal variation in exudate production rates by the plants, behavioral ecology of visiting tree shrews, and the mechanism by which the plants signal to tree shrews that their pitchers represent a food source. Further research into this extraordinary animal-plant interaction is required to gain a better understanding of the benefits to the participating species. © 2010 Landes Bioscience

Common tree shrews and primates share leukocyte membrane antigens.

PubMed

Palley, L S; Schlossman, S F; Letvin, N L

1984-01-01

Monoclonal antibodies reactive with human peripheral blood lymphocyte and myeloid cell surface antigens were utilized to study the phylogeny of the common tree shrew. Blood cells from the common tree shrew, but not the bat or short-tailed shrew, react with certain of these antibodies. These data strengthen the argument that the Tupaiidae are primitive primates rather than insectivores. They also indicate that this approach should be useful for further work in taxonomic systemization.

Estimation of body surface area in the musk shrew ( Suncus murinus): a small animal for testing chemotherapy-induced emesis.

PubMed

Eiseman, Julie L; Sciullo, Michael; Wang, Hong; Beumer, Jan H; Horn, Charles C

2017-10-01

Several cancer chemotherapies cause nausea and vomiting, which can be dose-limiting. Musk shrews are used as preclinical models for chemotherapy-induced emesis and for antiemetic effectiveness. Unlike rats and mice, shrews possess a vomiting reflex and demonstrate an emetic profile similar to humans, including acute and delayed phases. As with most animals, dosing of shrews is based on body weight, while translation of such doses to clinically equivalent exposure requires doses based on body surface area. In the current study body surface area in musk shrews was directly assessed to determine the Meeh constant (K m ) conversion factor (female = 9.97, male = 9.10), allowing estimation of body surface area based on body weight. These parameters can be used to determine dosing strategies for shrew studies that model human drug exposures, particularly for investigating the emetic liability of cancer chemotherapeutic agents.

Organization of the main olfactory bulbs of some mammals: musk shrews, moles, hedgehogs, tree shrews, bats, mice, and rats.

PubMed

Kosaka, Katsuko; Kosaka, Toshio

2004-04-19

We immunohistochemically examined the organization of the main olfactory bulbs (MOBs) in seven mammalian species, including moles, hedgehogs, tree shrews, bats, and mice as well as laboratory musk shrews and rats. We focused our investigation on two points: 1) whether nidi, particular spheroidal synaptic regions subjacent to glomeruli, which we previously reported for the laboratory musk shrew MOBs, are also present in other animals and 2) whether the compartmental organization of glomeruli and two types of periglomerular cells we proposed for the rat MOBs are general in other animals. The general laminar pattern was similar among these seven species, but discrete nidi and the nidal layer were recognized only in two insectivores, namely, the mole and laboratory musk shrew. Olfactory marker protein-immunoreactive (OMP-IR) axons extended beyond the limits of the glomerular layer (GL) into the superficial region of the external plexiform layer (EPL) or the nidal layer in the laboratory musk shrew, mole, hedgehog, and tree shrew but not in bat, mouse, and rat. We observed, in nidi and the nidal layer in the mole and laboratory musk shrew MOBs, only a few OMP-IR axons. In the hedgehog, another insectivore, OMP-IR processes extending from the glomeruli were scattered and intermingled with calbindin D28k-IR cells at the border between the GL and the EPL. In the superficial region of the EPL of the tree shrew MOBs, there were a small number of tiny glomerulus-like spheroidal structures where OMP-IR axons protruding from glomeruli were intermingled with dendritic branches of surrounding calbindin D28k-IR cells. Furthermore, we recognized the compartmental organization of glomeruli and two types of periglomerular cells in the MOBs of all of the mammals we examined. These structural features are therefore considered to be common and important organizational principles of the MOBs. Copyright 2004 Wiley-Liss, Inc.

Stereotaxic 18F-FDG PET and MRI templates with three-dimensional digital atlas for statistical parametric mapping analysis of tree shrew brain.

PubMed

Huang, Qi; Nie, Binbin; Ma, Chen; Wang, Jing; Zhang, Tianhao; Duan, Shaofeng; Wu, Shang; Liang, Shengxiang; Li, Panlong; Liu, Hua; Sun, Hua; Zhou, Jiangning; Xu, Lin; Shan, Baoci

2018-01-01

Tree shrews are proposed as an alternative animal model to nonhuman primates due to their close affinity to primates. Neuroimaging techniques are widely used to study brain functions and structures of humans and animals. However, tree shrews are rarely applied in neuroimaging field partly due to the lack of available species specific analysis methods. In this study, 10 PET/CT and 10 MRI images of tree shrew brain were used to construct PET and MRI templates; based on histological atlas we reconstructed a three-dimensional digital atlas with 628 structures delineated; then the digital atlas and templates were aligned into a stereotaxic space. Finally, we integrated the digital atlas and templates into a toolbox for tree shrew brain spatial normalization, statistical analysis and results localization. We validated the feasibility of the toolbox by simulated data with lesions in laterodorsal thalamic nucleus (LD). The lesion volumes of simulated PET and MRI images were (12.97±3.91)mm 3 and (7.04±0.84)mm 3 . Statistical results at p<0.005 showed the lesion volumes of PET and MRI were 13.18mm 3 and 8.06mm 3 in LD. To our knowledge, we report the first PET template and digital atlas of tree shrew brain. Compared to the existing MRI templates, our MRI template was aligned into stereotaxic space. And the toolbox is the first software dedicated for tree shrew brain analysis. The templates and digital atlas of tree shrew brain, as well as the toolbox, facilitate the use of tree shrews in neuroimaging field. Copyright © 2017 Elsevier B.V. All rights reserved.

Factors influencing the variation in capture rates of shrews in southern California, USA

USGS Publications Warehouse

Laakkonen, Juha; Fisher, Robert N.; Case, Ted J.

2003-01-01

We examined the temporal variation in capture rates of shrewsNotiosorex crawfordi (Coues, 1877) and Sorex ornatus (Merriam, 1895) in 20 sites representing fragmented and continuous habitats in southern California, USA. InN. crawfordi, the temporal variation was significantly correlated with the mean capture rates. Of the 6 landscape variables analyzed (size of the landscape, size of the sample area, altitude, edge, longitude and latitude), sample area was positively correlated with variation in capture rates ofN. crawfordi. InS. ornatus, longitude was negatively correlated with variation in capture rates. Analysis of the effect of precipitation on the short- and long-term capture rates at 2 of the sites showed no correlation between rainfall and capture rates of shrews even though peak number of shrews at both sites were reached during the year of highest amount of rainfall. A key problem confounding capture rates of shrews in southern California is the low overall abundance of both shrew species in all habitats and seasons.

Resting-Associated Vocalization Emitted by Captive Asian House Shrews (Suncus murinus): Acoustic Structure and Variability in an Unusual Mammalian Vocalization

PubMed Central

Schneiderová, Irena; Zouhar, Jan

2014-01-01

Shrews have rich vocal repertoires that include vocalizations within the human audible frequency range and ultrasonic vocalizations. Here, we recorded and analyzed in detail the acoustic structure of a vocalization with unclear functional significance that was spontaneously produced by 15 adult, captive Asian house shrews (Suncus murinus) while they were lying motionless and resting in their nests. This vocalization was usually emitted repeatedly in a long series with regular intervals. It showed some structural variability; however, the shrews most frequently emitted a tonal, low-frequency vocalization with minimal frequency modulation and a low, non-vocal click that was clearly noticeable at its beginning. There was no effect of sex, but the acoustic structure of the analyzed vocalizations differed significantly between individual shrews. The encoded individuality was low, but it cannot be excluded that this individuality would allow discrimination of family members, i.e., a male and female with their young, collectively resting in a common nest. The question remains whether the Asian house shrews indeed perceive the presence of their mates, parents or young resting in a common nest via the resting-associated vocalization and whether they use it to discriminate among their family members. Additional studies are needed to explain the possible functional significance of resting-associated vocalizations emitted by captive Asian house shrews. Our study highlights that the acoustic communication of shrews is a relatively understudied topic, particularly considering that they are highly vocal mammals. PMID:25390304

Deciduous tooth size standards for American blacks.

PubMed

Vaughan, M D; Harris, E F

1992-10-01

Normative standards for tooth sizes are valuable for assessing a given patient's status, both clinically and for evaluating intrinsic (e.g., genetic, chromosomal aberrations) and acquired conditions. There are, however, very few published standards for American Blacks and none for the deciduous teeth. Mesiodistal and buccolingual crown diameters are reported here for a series of 100 Black children. As with the permanent dentition, the primary teeth of Blacks are appreciably larger than Whites, though the amount differs by tooth type. In general, while all teeth are larger than norms for Whites, the posterior teeth (m1, m2) are preferentially larger. Applications of these standards are discussed.

Co-circulation of Soricid- and Talpid-borne Hantaviruses in Poland

PubMed Central

Gu, Se Hun; Hejduk, Janusz; Markowski, Janusz; Kang, Hae Ji; Markowski, Marcin; Połatyńska, Małgorzata; Sikorska, Beata; Liberski, Paweł P.; Yanagihara, Richard

2014-01-01

Previously, we reported the discovery of a genetically distinct hantavirus, designated Boginia virus (BOGV), in the Eurasian water shrew (Neomys fodiens), as well as the detection of Seewis virus (SWSV) in the Eurasian common shrew (Sorex araneus), in central Poland. In this expanded study of 133 shrews and 69 moles captured during 2010–2013 in central and southeastern Poland, we demonstrate the co-circulation of BOGV in the Eurasian water shrew and SWSV in the Eurasian common shrew, Eurasian pygmy shrew (Sorex minutus) and Mediterranean water shrew (Neomys anomalus). In addition, we found high prevalence of Nova virus (NVAV) infection in the European mole (Talpa europaea), with evidence of NVAV RNA in heart, lung, liver, kidney, spleen and intestine. The nucleotide and amino acid sequence variation of the L segment among the SWSV strains was 0–18.8% and 0–5.4%, respectively. And for the 38 NVAV strains from European moles captured in Huta Dłutowska, the L-segment genetic similarity ranged from 94.1–100% at the nucleotide level and 96.3–100% at the amino acid level. Phylogenetic analyses showed geographic-specific lineages of SWSV and NVAV in Poland, not unlike that of rodent-borne hantaviruses, suggesting long-standing host-specific adaptation. The co-circulation and distribution of BOGV, SWSV and NVAV in Poland parallels findings of multiple hantavirus species coexisting in their respective rodent reservoir species elsewhere in Europe. Also, the detection of SWSV in three syntopic shrew species resembles spill over events observed among some rodent-borne hantaviruses. PMID:25445646

Co-circulation of soricid- and talpid-borne hantaviruses in Poland.

PubMed

Gu, Se Hun; Hejduk, Janusz; Markowski, Janusz; Kang, Hae Ji; Markowski, Marcin; Połatyńska, Małgorzata; Sikorska, Beata; Liberski, Paweł P; Yanagihara, Richard

2014-12-01

Previously, we reported the discovery of a genetically distinct hantavirus, designated Boginia virus (BOGV), in the Eurasian water shrew (Neomys fodiens), as well as the detection of Seewis virus (SWSV) in the Eurasian common shrew (Sorex araneus), in central Poland. In this expanded study of 133 shrews and 69 moles captured during 2010-2013 in central and southeastern Poland, we demonstrate the co-circulation of BOGV in the Eurasian water shrew and SWSV in the Eurasian common shrew, Eurasian pygmy shrew (Sorex minutus) and Mediterranean water shrew (Neomys anomalus). In addition, we found high prevalence of Nova virus (NVAV) infection in the European mole (Talpa europaea), with evidence of NVAV RNA in heart, lung, liver, kidney, spleen and intestine. The nucleotide and amino acid sequence variation of the L segment among the SWSV strains was 0-18.8% and 0-5.4%, respectively. And for the 38 NVAV strains from European moles captured in Huta Dłutowska, the L-segment genetic similarity ranged from 94.1%-100% at the nucleotide level and 96.3%-100% at the amino acid level. Phylogenetic analyses showed geographic-specific lineages of SWSV and NVAV in Poland, not unlike that of rodent-borne hantaviruses, suggesting long-standing host-specific adaptation. The co-circulation and distribution of BOGV, SWSV and NVAV in Poland parallels findings of multiple hantavirus species co-existing in their respective rodent reservoir species elsewhere in Europe. Also, the detection of SWSV in three syntopic shrew species resembles spill over events observed among some rodent-borne hantaviruses. Copyright © 2014 Elsevier B.V. All rights reserved.

Histopathological changes in the liver of tree shrew (Tupaia belangeri chinensis) persistently infected with hepatitis B virus.

PubMed

Ruan, Ping; Yang, Chun; Su, Jianjia; Cao, Ji; Ou, Chao; Luo, Chengpiao; Tang, Yanping; Wang, Qi; Yang, Fang; Shi, Junlin; Lu, Xiaoxu; Zhu, Linqun; Qin, Hong; Sun, Wen; Lao, Yuanzhi; Li, Yuan

2013-11-12

An animal model for HBV that more closely approximates the disease in humans is needed. The tree shrew (Tupaia belangeri) is closely related to primates and susceptible to HBV. We previously established that neonatal tree shrews can be persistently infected with HBV in vivo, and here present a six year follow-up histopathological study of these animals. Group A consists of six tree shrews with persistent HBV infection, group B consists of three tree shrews with suspected persistent HBV infection, while group C consists of four tree shrews free of HBV infection. Serum and liver tissues samples were collected periodically from all animals. HBV antigen and HBV antibodies were detected by ELISA and/or TRFIA. HBV DNA in serum and in liver biopsies was measured by FQ-PCR. Liver biopsies were applied for general histopathologic observation and scoring, immunohistochemical detections of HBsAg and HBcAg, and ultrastructural observation with electron microscope technique. Hydropic, fatty and eosinophilic degeneration of hepatocytes, lymphocytic infiltration and hyperplasia of small bile ducts in the portal area were observed in group A. One animal infected with HBV for over six years showed multiple necrotic areas which had fused to form bridging necrosis and fibrosis, and megalocytosis. The hepatic histopathological scores of group A were higher than those of group B and C. The histopathological score correlated positively with the duration of infection. Hepatic histopathological changes observed in chronically HBV-infected tree shrews are similar to those observed in HBV-infected humans. The tree shrew may represent a novel animal model for HBV infection.

Captures of Crawford's gray shrews (Notiosorex crawfordi) along the Rio Grande in central New Mexico

Treesearch

Alice Chung-MacCoubrey; Heather L. Bateman; Deborah M. Finch

2009-01-01

We captured >2000 Crawford's gray shrews (Notiosorex crawfordi) in a riparian forest mainly consisting of cottonwoods (Populus deltoides) along the Rio Grande in central New Mexico. Little has been published about abundance and habitat of Crawford's gray shrew throughout its distributional range. During 7 summers, we...

The identity of the enigmatic "Black Shrew" (Sorex niger Ord, 1815)

USGS Publications Warehouse

Woodman, Neal

2013-01-01

The scientific name Sorex niger Ord, 1815 (Mammalia, Soricidae) was originally applied to a North American species that George Ord called the “Black Shrew.” The origin of the name “Black Shrew,” however, was obscure, and Samuel Rhoads subsequently wrote that the species represented by this name could not be determined. The names Sorex niger Ord and Black Shrew have since been mostly forgotten. Two of Ord's contemporaries, however, noted that Ord's use of these names probably alluded to Benjamin Smith Barton's Black Shrew, whose discovery near Philadelphia was announced by Barton in 1806. Examination of two unpublished illustrations of the Black Shrew made by Barton indicates that the animal depicted is Blarina brevicauda (Say, 1822). Had the connection between Ord's and Barton's names been made more clearly, one of the most common mammals in eastern North America would bear a different scientific name today. This connection also would have affected the validity of Sorex niger Horsfield, 1851. While Sorex niger Ord remains a nomen nudum, the animal it referenced can now be identified.

Responses of wild small mammals to arsenic pollution at a partially remediated mining site in Southern France.

PubMed

Drouhot, Séverine; Raoul, Francis; Crini, Nadia; Tougard, Christelle; Prudent, Anne-Sophie; Druart, Coline; Rieffel, Dominique; Lambert, Jean-Claude; Tête, Nicolas; Giraudoux, Patrick; Scheifler, Renaud

2014-02-01

Partial remediation actions at a former gold mine in Southern France led to a mosaic of contaminated and rehabilitated zones. In this study, the distribution of arsenic and its potential adverse effects on small mammals were investigated. The effectiveness of remediation for reducing the transfer of this element into wildlife was also discussed. Arsenic levels were measured in the soil and in the stomach contents, livers, kidneys, and lungs of four small mammal species (the wood mouse (Apodemus sylvaticus), the Algerian mouse (Mus spretus), the common vole (Microtus arvalis), and the greater white-toothed shrew (Crocidura russula)). The animals were caught at the former extraction site, in zones with three different levels of remediation treatments, and at a control site. Arsenic concentrations in the soil were highly spatially heterogeneous (ranging from 29 to 18,900 μg g(-1)). Despite the decrease in arsenic concentrations in the remediated soils, both wood mice and Algerian mice experienced higher oral exposure to arsenic in remediated zones than in the control area. The accumulated arsenic in their organs showed higher intra-zonal variability than the arsenic distribution in the soil, suggesting that, in addition to remediation processes, other variables can help explain arsenic transfer to wildlife, such as the habitat and diet preferences of the animals or their mobility. A weak but significant correlation between arsenic concentration and body condition was observed, and weak relationships between the liver/kidney/lung mass and arsenic levels were also detected, suggesting possible histological alterations. © 2013.

Shrews in managed northern hardwood stands in the Allegheny Mountains of West Virginia

Treesearch

W. Mark Ford; Chris A. Dobony; John W. Edwards

2002-01-01

Shrews are an abundant and important component of the mammalian fauna in central and southern Appalachian forested habitats. Because most soricids are small, cryptic, and difficult to survey, they typically have been underrepresented in research examining effects of forest management on small mammals. To assess shrew response to clearcutting northern hardwood forests...

Identification and Characterization of Liver MicroRNAs of the Chinese Tree Shrew via Deep Sequencing.

PubMed

Feng, Yue; Feng, Yue-Mei; Feng, Yang; Lu, Caixia; Liu, Li; Sun, Xiaomei; Dai, Jiejie; Xia, Xueshan

2015-10-01

Chinese tree shrew (Tupaia belangeri chinensis) is a small animal that possess many features, which are valuable in biomedical research, as experimental models. Currently, there are numerous attempts to utilize tree shrews as models for hepatitis C virus (HCV) infection. This study aimed to construct a liver microRNA (miRNA) data of the tree shrew. Three second filial generation tree shrews were used in this study. Total RNA was extracted from each liver of the tree shrew and equal quality mixed, then reverse-transcribed to complementary DNA (cDNA). The cDNAs were amplified by polymerase chain reaction and subjected to high-throughput sequencing. A total of 2060 conserved miRNAs were identified through alignment with the mature miRNAs in miRBase 20.0 database. The gene ontology and Kyoto encyclopedia of genes and genomes analyses of the target genes of the miRNAs revealed several candidate miRNAs, genes and pathways that may involve in the process of HCV infection. The abundance of miR-122 and Let-7 families and their other characteristics provided us more evidences for the utilization of this animal, as a potential model for HCV infection and other related biomedical research. Moreover, 80 novel microRNAs were predicted using the software Mireap. The top 3 abundant miRNAs were validated in other tree samples, based on stem-loop quantitative reverse transcription-polymerase chain reaction. According to the liver microRNA data of Chinese tree shrew, characteristics of the miR-122 and Let-7 families further highlight the suitability of tree shrew as the animal model in HCV research.

Assessing the influence of skin color and tooth shade value on perceived smile attractiveness.

PubMed

Sabherwal, Ruchika S; Gonzalez, Juan; Naini, Farhad B

2009-06-01

The authors conducted a study to determine whether variations in skin color would influence perceptions of smile attractiveness for a given tooth shade value. Using a photograph of a woman smiling, the authors altered skin color to consist of four tones (fair, fair/medium, medium/dark and dark) and altered tooth shade value (brightness) to range from 00 (brightest) to 05 (darkest). Two groups of judges (70 dentists, 70 laypeople) completed a questionnaire and rated the images for smile attractiveness. For most tooth shade values (00, 01, 03, 04, 05), multiple mixed linear regression showed that variation in skin color influenced respondents' perceptions of smile attractiveness (P < .001). For images corresponding to tooth shade values 01, 02, 03, 04 and 05, men provided lower ratings than did women (P < .05). Attractiveness ratings increased with the age of participants (P < .05). Dentists rated images higher than did laypeople (P < .05). Variation in skin color for most tooth shade values influenced dentists' and laypeople's perceived smile attractiveness. Dentists and laypeople did not perceive the brightest tooth shade to be the most attractive, and they did not perceive all skin colors to be equally attractive with bright white teeth. Respondents perceived dark skin with bright white teeth and fair skin with dark teeth as relatively unattractive.

Clinical and patient reported outcomes of bleaching effectiveness.

PubMed

Klaric Sever, Eva; Budimir, Zrinka; Cerovac, Matea; Stambuk, Mario; Par, Matej; Negovetic Vranic, Dubravka; Tarle, Zrinka

2018-01-01

The objective of this study is to evaluate clinical and patient reported outcomes of different bleaching products. Thirty participants were randomly divided into three bleaching groups (n = 10). Bleaching was performed with high concentrations of hydrogen peroxide (HP) - Boost (40%) and Dash (30%), and with prefabricated splints Bite&White (6% HP). Tooth colour was measured before, immediately after, and 1 and 6 months after the bleaching by using classical shade guide and spectrophotometer. Tooth hypersensitivity was self-rated by patients on the Wong-Baker's face scale. Patient satisfaction was evaluated on a 7-point Likert-type scales that measured perceived performance and importance of different characteristics of bleaching treatment. All products were effective in teeth colour change (ΔE > 3.3), which was significantly higher for Boost (p = .016) and Dash (p = .024) than Bite&White treatment. Perception of hypersensitivity was the highest in Boost group, followed by Dash and Bite&White treatment. Most of the patients were satisfied with final tooth colour, length and comfort during treatment, but were dissatisfied with the stability of bleached tooth colour. Materials with the higher concentrations of bleaching agent demonstrated greater bleaching effectiveness than at-home bleaching product, but also a greater hypersensitivity. Lengthening the treatment process, but achieving a more stable tooth colour may improve the perceived value of a bleaching service.

Development and microstructure of tooth histotypes in the blue shark, Prionace glauca (Carcharhiniformes: Carcharhinidae) and the great white shark, Carcharodon carcharias (Lamniformes: Lamnidae).

PubMed

Moyer, Joshua K; Riccio, Mark L; Bemis, William E

2015-07-01

Elasmobranchs exhibit two distinct arrangements of mineralized tissues in the teeth that are known as orthodont and osteodont histotypes. Traditionally, it has been said that orthodont teeth maintain a pulp cavity throughout tooth development whereas osteodont teeth are filled with osteodentine and lack a pulp cavity when fully developed. We used light microscopy, scanning electron microscopy, and high-resolution micro-computed tomography to compare the structure and development of elasmobranch teeth representing the two histotypes. As an example of the orthodont histotype, we studied teeth of the blue shark, Prionace glauca (Carcharhiniformes: Carcharhinidae). For the osteodont histotype, we studied teeth of the great white shark, Carcharodon carcharias (Lamniformes: Lamnidae). We document similarities and differences in tooth development and the microstructure of tissues in these two species and review the history of definitions and interpretations of elasmobranch tooth histotypes. We discuss a possible correlation between tooth histotype and tooth replacement and review the history of histotype differentiation in sharks. We find that contrary to a long held misconception, there is no orthodentine in the osteodont teeth of C. carcharias. © 2015 Wiley Periodicals, Inc.

White light scanner-based repeatability of 3-dimensional digitizing of silicon rubber abutment teeth impressions

PubMed Central

Jeon, Jin-Hun; Lee, Kyung-Tak; Kim, Hae-Young; Kim, Ji-Hwan

2013-01-01

PURPOSE The aim of this study was to evaluate the repeatability of the digitizing of silicon rubber impressions of abutment teeth by using a white light scanner and compare differences in repeatability between different abutment teeth types. MATERIALS AND METHODS Silicon rubber impressions of a canine, premolar, and molar tooth were each digitized 8 times using a white light scanner, and 3D surface models were created using the point clouds. The size of any discrepancy between each model and the corresponding reference tooth were measured, and the distribution of these values was analyzed by an inspection software (PowerInspect 2012, Delcamplc., Birmingham, UK). Absolute values of discrepancies were analyzed by the Kruskal-Wallis test and multiple comparisons (α=.05). RESULTS The discrepancy between the impressions for the canine, premolar, and molar teeth were 6.3 µm (95% confidence interval [CI], 5.4-7.2), 6.4 µm (95% CI, 5.3-7.6), and 8.9 µm (95% CI, 8.2-9.5), respectively. The discrepancy of the molar tooth impression was significantly higher than that of other tooth types. The largest variation (as mean [SD]) in discrepancies was seen in the premolar tooth impression scans: 26.7 µm (95% CI, 19.7-33.8); followed by canine and molar teeth impressions, 16.3 µm (95% CI, 15.3-17.3), and 14.0 µm (95% CI, 12.3-15.7), respectively. CONCLUSION The repeatability of the digitizing abutment teeth's silicon rubber impressions by using a white light scanner was improved compared to that with a laser scanner, showing only a low mean discrepancy between 6.3 µm and 8.9 µm, which was in an clinically acceptable range. Premolar impression with a long and narrow shape showed a significantly larger discrepancy than canine and molar impressions. Further work is needed to increase the digitizing performance of the white light scanner for deep and slender impressions. PMID:24353885

Isolation and identification of symbiotic bacteria from the skin, mouth, and rectum of wild and captive tree shrews.

PubMed

Li, Gui; Lai, Ren; Duan, Gang; Lyu, Long-Bao; Zhang, Zhi-Ye; Liu, Huang; Xiang, Xun

2014-11-18

Endosymbionts influence many aspects of their hosts' health conditions, including physiology, development, immunity, metabolism, etc. Tree shrews (Tupaia belangeri chinensis) have attracted increasing attention in modeling human diseases and therapeutic responses due to their close relationship with primates. To clarify the situation of symbiotic bacteria from their body surface, oral cavity, and anus, 12 wild and 12 the third generation of captive tree shrews were examined. Based on morphological and cultural characteristics, physiological and biochemical tests, as well as the 16S rDNA full sequence analysis, 12 bacteria strains were isolated and identified from the wild tree shrews: body surface: Bacillus subtilis (detection rate 42%), Pseudomonas aeruginosa (25%), Staphlococcus aureus (33%), S. Epidermidis (75%), Micrococcus luteus (25%), Kurthia gibsonii (17%); oral cavity: Neisseria mucosa (58%), Streptococcus pneumonia (17%); anus: Enterococcus faecalis (17%), Lactococus lactis (33%), Escherichia coli (92%), Salmonella typhosa (17%); whereas, four were indentified from the third generation captive tree shrews: body surface: S. epidermidis (75%); oral cavity: N.mucosa (67%); anus: L. lactis (33%), E. coli (100%). These results indicate that S. epidermidis, N. mucosa, L. lactis and E. coli were major bacteria in tree shrews, whereas, S. aureus, M. luteus, K. gibsonii, E. faecalis and S. typhosa were species-specific flora. This study facilitates the future use of tree shrews as a standard experimental animal and improves our understanding of the relationship between endosymbionts and their hosts.

Comparison of maxillary anterior tooth width and facial dimensions of 3 ethnicities.

PubMed

Parciak, Ewa C; Dahiya, Ankur T; AlRumaih, Hamad S; Kattadiyil, Mathew T; Baba, Nadim Z; Goodacre, Charles J

2017-10-01

As the cosmetic demands of patients increase, determining the appropriate dimensions of the maxillary anterior teeth has become increasingly relevant. The relationship between facial measurements and tooth size provide guidance for maxillary anterior tooth size selection. However, most publications on this topic have focused on the white population, and more data for tooth sizes and their proportions in other ethnicities are needed. The purpose of this observational study was to investigate the relationship between the mesiodistal dimensions of the 6 maxillary anterior teeth and the bizygomatic width, interpupillary distance, intercanthal distance, interalar width, and intercommissural width of individuals of Asian, African-American, and white ethnicities. Standardized digital images of 360 participants (120 Asian, 120 African-American, and 120 white) were used to measure facial segments. Individual dimensions of the 6 maxillary anterior teeth were measured using stone casts with digital sliding caliper. The combined width of the 6 maxillary anterior teeth on a straight line corresponded to the sum of the anterior tooth width. The means and standard deviations from descriptive measurements were calculated and analyzed for face and maxillary anterior tooth ratios and correlations. Statistical analysis was done using the Kruskal-Wallis procedure to compare facial and tooth parameters among the 3 ethnicities. Appropriate post hoc comparisons that adjusted for multiple testing were conducted when warranted (α=.05). The Spearman rho correlation, a nonparametric correlate of the Pearson correlation, was used to associate the facial and tooth parameters within the strata of sex and ethnicity. No consistent ratios were found among the examined facial dimensions and the mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities, except for the central incisor width-to-bizygomatic width ratio. No correlations were found between the facial dimensions and mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities except in Asian women. For Asian women, the intercommissural width correlated with the width of the central incisor (P=.001), the width of 2 central incisors (P=.001), the width of 4 incisors (P=.003), and the width of 6 maxillary anterior teeth (P=.005). No facial proportions by which the exact width of maxillary anterior teeth could be predicted were found in Asian, African-American, or white populations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Molecular cloning and characterization of the full-length cDNA encoding the tree shrew (tupaia belangeri) CD28

NASA Astrophysics Data System (ADS)

Huang, Xiaoyan; Yan, Yan; Wang, Sha; Wang, Qinying; Shi, Jian; Shao, Zhanshe; Dai, Jiejie

2017-11-01

CD28 is one of the most important co-stimulatory molecules expressed by naive and primed T cells. The tree shrews (Tupaia belangeri), as an ideal animal model for analyzing mechanism of human diseases receiving extensive attentions, demands essential research tools, in particular in the study of cellular markers and monoclonal antibodies for immunological studies. However, little is known about tree shrew CD28 (tsCD28) until now. In this study, a 663 bp of the full-length CD28 cDNA, encoding a polypeptide of 220 amino acids was cloned from tree shrew spleen lymphocytes. The nucleotide sequence of the tsCD28 showed 85%, 76%, and 75% similarities with human, rat, and mouse, respectively, which showed the affinity relationship between tree shrew and human is much closer than between human and rodents. The open reading frame (ORF) sequence of tsCD28 gene was predicted to be in correspondence with the signal sequence, immunoglobulin variable-like (IgV) domain, transmembrane domain and cytoplasmic tail, respectively.We also analyzed its molecular characteristics with other mammals by using biology software such as Clustal W 2.0 and so forth. Our results showed that tsCD28 contained many features conserved in CD28 genes from other mammals, including conserved signal peptide and glycosylation sites, and several residues responsible for binding to the CD28R, and the tsCD28 amino acid sequence were found a close genetic relationship with human and monkey. The crystal structure and surface charge revealed most regions of tree shrew CD28 molecule surface charges are similar as human. However, compared with human CD28 (hCD28) regions, in some areas, the surface positive charge of tsCD28 was less than hCD28, which may affect antibody binding. The present study is the first report of cloning and characterization of CD28 in tree shrew. This study provides a theoretical basis for the further study the structure and function of tree shrew CD28 and utilize tree shrew as an effective animal model of human disease.

High shrew diversity on Alaska's Seward Peninsula: Community assembly and environmental change

USGS Publications Warehouse

Hope, Andrew G.

2012-01-01

In September 2010, 6 species of shrews (genus: Sorex) were collected at a single locality on the Seward Peninsula of Alaska. Such high sympatric diversity within a single mammalian genus is seldom realized. This phenomenon at high latitudes highlights complex Arctic community dynamics that reflect significant turnover through time as a consequence of environmental change. Each of these shrew species occupies a broad geographic distribution collectively spanning the entire Holarctic, although the study site lies within Eastern Beringia, near the periphery of all individual ranges. A review of published genetic evidence reflects a depauperate shrew community within ice-free Beringia through the last glaciation, and recent assembly of current diversity during the Holocene.

Host switch during evolution of a genetically distinct hantavirus in the American shrew mole (Neurotrichus gibbsii)

PubMed Central

Kang, Hae Ji; Bennett, Shannon N.; Dizney, Laurie; Sumibcay, Laarni; Arai, Satoru; Ruedas, Luis A.; Song, Jin-Won; Yanagihara, Richard

2009-01-01

A genetically distinct hantavirus, designated Oxbow virus (OXBV), was detected in tissues of an American shrew mole (Neurotrichus gibbsii), captured in Gresham, Oregon, in September 2003. Pairwise analysis of full-length S- and M- and partial L-segment nucleotide and amino acid sequences of OXBV indicated low sequence similarity with rodent-borne hantaviruses. Phylogenetic analyses using maximum-likelihood and Bayesian methods, and host-parasite evolutionary comparisons, showed that OXBV and Asama virus, a hantavirus recently identified from the Japanese shrew mole (Urotrichus talpoides), were related to soricine shrew-borne hantaviruses from North America and Eurasia, respectively, suggesting parallel evolution associated with cross-species transmission. PMID:19394994

Somatostatin-immunoreactive senile plaque-like structures in the frontal cortex and nucleus accumbens of aged tree shrews and Japanese macaques.

PubMed

Yamashita, Akiko; Fuchs, Eberhard; Taira, Masato; Yamamoto, Takamitsu; Hayashi, Motoharu

2012-06-01

Previously, we demonstrated decreased expression of somatostatin mRNA in aged macaque brain, particularly in the prefrontal cortex. To investigate whether or not this age-dependent decrease in mRNA is related to morphological changes, we analyzed somatostatin cells in the cerebra of aged Japanese macaques and compared them with those in rats and tree shrews, the latter of which are closely related to primates. Brains of aged macaques, tree shrews, and rats were investigated by immunohistochemistry with special emphasis on somatostatin. We observed degenerating somatostatin-immunoreactive cells in the cortices of aged macaques and tree shrews. Somatostatin-immunoreactive senile plaque-like structures were found in areas 6 and 8 and in the nucleus accumbens of macaques, as well as in the nucleus accumbens and the cortex of aged tree shrews, where amyloid accumulations were observed. Somatostatin degenerations may be related to amyloid accumulations and may play roles in impairments of cognitive functions during aging. © 2012 John Wiley & Sons A/S.

Lead concentrations: Bats vs. terrestrial small mammals collected near a major highway

USGS Publications Warehouse

Clark, D.R.

1979-01-01

Wholebody lead concentrations of two species of bats (big brown and little brown) and three species of terrestrial mammals (meadow voles, white-footed mice, and short-tailed shrews) trapped along the Baltimore-Washington Parkway in 1976 are compared, including embryo lead concentration. These data are also compared to those of previous studies conducted in Illinois and Virginia within 20 miles of highways with high traffic volumes. Minimum dosages of various lead compounds that cause mortality or reproductive impairment in six species of domestic mammals (horses, cattle, sheep, dogs, rats, and mice) are noted.

A comparative study of sex difference in calbindin neurons among mice, musk shrews, and Japanese quails.

PubMed

Moe, Yadanar; Tanaka, Tomoko; Morishita, Masahiro; Ohata, Ryoko; Nakahara, Chihiro; Kawashima, Takaharu; Maekawa, Fumihiko; Sakata, Ichiro; Sakai, Takafumi; Tsukahara, Shinji

2016-09-19

The medial preoptic nucleus (MPN) and the bed nucleus of the stria terminalis (BNST) of mice contain sexually dimorphic nuclei (SDNs) that are larger and have more neurons expressing calbindin D-28K (CB), a calcium-binding protein, in males than females. However, it is largely unknown whether such SDNs exist in species other than rodents. In this study, we performed an immunohistochemical study of CB in the MPN and BNST of musk shrews and Japanese quails to examine the existence of homologs of SDNs in mice. Like mice, musk shrews had a SDN exhibiting male-biased sex differences in volume and CB-immunoreactive (ir) cell number in the MPN. The BNST of musk shrews also contained a male-biased SDN, but consisted of non-CB neurons. The paratenial thalamic nucleus of musk shrews, but not mice, had more CB-ir cells in males than females. In Japanese quails of both sexes, CB-ir cells in the MPN and BNST were extremely small in number and did not cluster. These results suggest that the distribution of CB neurons differs among these species. Musk shrews may have a homolog of the SDN composed of CB neurons in the MPN of mice. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Drug Target Mining and Analysis of the Chinese Tree Shrew for Pharmacological Testing

PubMed Central

Liu, Jie; Lee, Wen-hui; Zhang, Yun

2014-01-01

The discovery of new drugs requires the development of improved animal models for drug testing. The Chinese tree shrew is considered to be a realistic candidate model. To assess the potential of the Chinese tree shrew for pharmacological testing, we performed drug target prediction and analysis on genomic and transcriptomic scales. Using our pipeline, 3,482 proteins were predicted to be drug targets. Of these predicted targets, 446 and 1,049 proteins with the highest rank and total scores, respectively, included homologs of targets for cancer chemotherapy, depression, age-related decline and cardiovascular disease. Based on comparative analyses, more than half of drug target proteins identified from the tree shrew genome were shown to be higher similarity to human targets than in the mouse. Target validation also demonstrated that the constitutive expression of the proteinase-activated receptors of tree shrew platelets is similar to that of human platelets but differs from that of mouse platelets. We developed an effective pipeline and search strategy for drug target prediction and the evaluation of model-based target identification for drug testing. This work provides useful information for future studies of the Chinese tree shrew as a source of novel targets for drug discovery research. PMID:25105297

Euarchontan affinity of Paleocene Afro-European adapisoriculid mammals and their origin in the late Cretaceous Deccan Traps of India.

PubMed

Smith, Thierry; De Bast, Eric; Sigé, Bernard

2010-04-01

The controversial family Adapisoriculidae, a group of shrew-sized Paleocene mammals, had proposed relationships with insectivores, marsupials and more recently to plesiadapiforms. Adapisoriculid remains are numerous in the early Paleocene locality of Hainin, Belgium, and allow us a test of these different phylogenetic hypotheses. Here, we identify the first tarsal bones of adapisoriculid mammals. The highly specialised bones indicate an arboreal mode of life with euarchontan affinity. Moreover, the tarsal bones are morphologically very close to those of the late Cretaceous Deccanolestes from the Deccan intertrappean beds of India, and also share several characters with the Paleocene plesiadapiforms and the extant cynocephalid dermopterans. The adapisoriculid affinities of Deccanolestes are also confirmed by tooth morphology, indicating that Deccanolestes is a primitive member of this family. These phylogenetic affinities suggest a paleobiogeographic scenario for the family with dispersal either via East Africa or across the Tethys area.

Functional and numerical responses of shrews to competition vary with mouse density.

PubMed

Eckrich, Carolyn A; Flaherty, Elizabeth A; Ben-David, Merav

2018-01-01

For decades, ecologists have debated the importance of biotic interactions (e.g., competition) and abiotic factors in regulating populations. Competition can influence patterns of distribution, abundance, and resource use in many systems but remains difficult to measure. We quantified competition between two sympatric small mammals, Keen's mice (Peromyscus keeni) and dusky shrews (Sorex monticolus), in four habitat types on Prince of Wales Island in Southeast Alaska. We related shrew density to that of mice using standardized regression models while accounting for habitat variables in each year from 2010-2012, during which mice populations peaked (2011) and then crashed (2012). Additionally, we measured dietary overlap and segregation using stable isotope analysis and kernel utilization densities and estimated the change in whole community energy consumption among years. We observed an increase in densities of dusky shrews after mice populations crashed in 2012 as expected under competitive release. In addition, competition coefficients revealed that the influence of Keen's mice was dependent on their density. Also in 2012, shrew diets shifted, indicating that they were able to exploit resources previously used by mice. Nonetheless, increases in shrew numbers only partially compensated for the community energy consumption because, as insectivores, they are unlikely to utilize all food types consumed by their competitors. In pre-commercially thinned stands, which exhibit higher diversity of resources compared to other habitat types, shrew populations were less affected by changes in mice densities. These spatially and temporally variable interactions between unlikely competitors, observed in a relatively simple, high-latitude island ecosystem, highlight the difficulty in assessing the role of biotic factors in structuring communities.

Extensive characterization of Tupaia belangeri neuropeptidome using an integrated mass spectrometric approach.

PubMed

Petruzziello, Filomena; Fouillen, Laetitia; Wadensten, Henrik; Kretz, Robert; Andren, Per E; Rainer, Gregor; Zhang, Xiaozhe

2012-02-03

Neuropeptidomics is used to characterize endogenous peptides in the brain of tree shrews (Tupaia belangeri). Tree shrews are small animals similar to rodents in size but close relatives of primates, and are excellent models for brain research. Currently, tree shrews have no complete proteome information available on which direct database search can be allowed for neuropeptide identification. To increase the capability in the identification of neuropeptides in tree shrews, we developed an integrated mass spectrometry (MS)-based approach that combines methods including data-dependent, directed, and targeted liquid chromatography (LC)-Fourier transform (FT)-tandem MS (MS/MS) analysis, database construction, de novo sequencing, precursor protein search, and homology analysis. Using this integrated approach, we identified 107 endogenous peptides that have sequences identical or similar to those from other mammalian species. High accuracy MS and tandem MS information, with BLAST analysis and chromatographic characteristics were used to confirm the sequences of all the identified peptides. Interestingly, further sequence homology analysis demonstrated that tree shrew peptides have a significantly higher degree of homology to equivalent sequences in humans than those in mice or rats, consistent with the close phylogenetic relationship between tree shrews and primates. Our results provide the first extensive characterization of the peptidome in tree shrews, which now permits characterization of their function in nervous and endocrine system. As the approach developed fully used the conservative properties of neuropeptides in evolution and the advantage of high accuracy MS, it can be portable for identification of neuropeptides in other species for which the fully sequenced genomes or proteomes are not available.

Preservation of hippocampal neuron numbers and hippocampal subfield volumes in behaviorally characterized aged tree shrews.

PubMed

Keuker, Jeanine I H; de Biurrun, Gabriel; Luiten, Paul G M; Fuchs, Eberhard

2004-01-19

Aging is associated with a decreased ability to store and retrieve information. The hippocampal formation plays a critical role in such memory processes, and its integrity is affected during normal aging. We used tree shrews (Tupaia belangeri) as an animal model of aging, because in many characteristics, tree shrews are closer to primates than they are to rodents. Young and aged male tree shrews performed a holeboard spatial memory task, which permits assessment of reference and working memory. Upon completion of the behavioral measurements, we carried out modified stereological analyses of neuronal numbers in various subdivisions of the hippocampus and used the Cavalieri method to calculate the volumes of these subfields. Results showed that the working memory of aged tree shrews was significantly impaired compared with that of young animals, whereas the hippocampus-dependent reference memory remained unchanged by aging. Estimation of the number of neurons revealed preserved neuron numbers in the subiculum, in the subregions CA1, CA2, CA3, and in the hilus of the dentate gyrus. Volume measurements showed no aging-related changes in the volume of any of these hippocampal subregions, or in the molecular and granule cell layers of the dentate gyrus of tree shrews. We conclude that the observed changes in memory performance in aging tree shrews are not accompanied by observable reductions of hippocampal neuron numbers or hippocampal volume, rather, the changes in memory performance are more likely the result of modified subcellular mechanisms that are affected by the aging process. Copyright 2003 Wiley-Liss, Inc.

Blarina brevicauda as a biological monitor of polychlorinated biphenyls: Evaluation of hepatic cytochrome p450 induction

USGS Publications Warehouse

Russell, J.S.; Halbrook, R.S.; Woolf, A.; French, J.B.; Melancon, M.J.

2004-01-01

We assessed the value of short-tailed shrews (Blarina brevicauda) as a possible biomonitor for polychlorinated biphenyl pollution through measurement of the induction of hepatic cytochrome P450 and associated enzyme activities. First, we checked the inducibility of four monooxygenases (benzyloxyresorufin-O-dealkylase [BROD], ethoxyresorufin-O-dealkylase [EROD], methoxyresorufin-O-dealkylase [MROD], and pentoxyresorufin-O-dealkylase [PROD]) by measuring the activity of these enzymes in hepatic microsomes prepared from shrews injected with $-naphthoflavone ($NF) or phenobarbital (PB), typical inducers of cytochrome P4501A (CYP1A) and CYP2B enzyme families, respectively. Enzyme activity was induced in shrews that received $NF but not in shrews that received PB; PROD was not induced by either exposure. Later, shrews were exposed to a mixture of polychlorinated biphenyls (PCBs) (Aroclor 1242:1254, in 1:2 ratio) at 0.6, 9.6, and 150 ppm in food, for 31 d. Induction in these shrews was measured by specific enzyme activity (BROD, EROD, and MROD) in hepatic microsomes, by western blotting of solubilized microsomes against antibodies to CYP1A or CYP2B, and by duration of sodium pentobarbital-induced sleep. These three CYP enzymes were induced in shrews by PCBs at similar levels of exposure as in cotton rat (Sigmodon hispidus). Neither sleep time nor the amount of CYP2B family protein were affected by PCB exposure. Blarina brevicauda can be a useful biomonitor of PCBs that induce CYP1A, especially in habitats where they are the abundant small mammal.

Blarina brevicauda as a biological monitor of polychlorinated biphenyls: evaluation of hepatic cytochrome P450 induction.

PubMed

Russell, Julie S; Halbrook, Richard S; Woolf, Alan; French, John B; Melancon, Mark J

2004-08-01

We assessed the value of short-tailed shrews (Blarina brevicauda) as a possible biomonitor for polychlorinated biphenyl pollution through measurement of the induction of hepatic cytochrome P450 and associated enzyme activities. First, we checked the inducibility of four monooxygenases (benzyloxyresorufin-O-dealkylase [BROD], ethoxyresorufin-O-dealkylase [EROD], methoxyresorufin-O-dealkylase [MROD], and pentoxyresorufin-O-dealkylase [PROD]) by measuring the activity of these enzymes in hepatic microsomes prepared from shrews injected with beta-naphthoflavone (betaNF) or phenobarbital (PB), typical inducers of cytochrome P4501A (CYP1A) and CYP2B enzyme families, respectively. Enzyme activity was induced in shrews that received betaNF but not in shrews that received PB; PROD was not induced by either exposure. Later, shrews were exposed to a mixture of polychlorinated biphenyls (PCBs) (Aroclor 1242:1254, in 1:2 ratio) at 0.6, 9.6, and 150 ppm in food, for 31 d. Induction in these shrews was measured by specific enzyme activity (BROD, EROD, and MROD) in hepatic microsomes, by western blotting of solubilized microsomes against antibodies to CYP1A or CYP2B, and by duration of sodium pentobarbital-induced sleep. These three CYP enzymes were induced in shrews by PCBs at similar levels of exposure as in cotton rat (Sigmodon hispidus). Neither sleep time nor the amount of CYP2B family protein were affected by PCB exposure. Blarina brevicauda can be a useful biomonitor of PCBs that induce CYP1A, especially in habitats where they are the abundant small mammal.

[Expressions and significance of TLR2 and TLR4 in Kupffer cells of tree shrews chronically infected with hepatitis B virus].

PubMed

Ruan, Ping; Yang, Chun; Su, Jianjia; Ou, Chao; Cao, Ji; Luo, Chengpiao; Tang, Yanping; Qin, Hong; Sun, Wen; Li, Yuan

2014-07-01

To investigate the mRNA expression levels of Toll-like receptors 2 (TLR2) and TLR4 in Kupffer cells of tree shrews that were chronically infected with hepatitis B virus (HBV), and the effects of these receptors on the function of Kupffer cells. The tree shrews were divided into tree shrews proved with chronic HBV infection, tree shrews suspected with chronic HBV infection, and normal control tree shrews without hepatitis B vaccination. The samples of serum and liver biopsy were collected periodically, and the levels of HBV DNA in serum and liver tissues were detected by fluorescence-based quantitative real-time PCR (qRT-PCR). Meanwhile, Kupffer cells were isolated from the biopsied liver tissues, and then purified and primarily cultured. Afterwards, qRT-PCR was applied to detect the mRNA expression levels of TLR2, TLR4 and TNF-α in the Kupffer cells. Cell migration assay and lysosome-specific fluorescent probe were adopted to analyze the effects of TLR2 and TLR4 on the migration capacity of Kupffer cells and the quantity of lysosomes in these cells. The mRNA expression levels of TLR2 and TLR4 in tree shrews proved with chronic HBV infection were lower than those in the ones suspected with chronic HBV infection and normal controls without hepatitis B vaccination (P<0.05), and these expression levels were all negatively correlated with the level of HBV DNA in liver tissues of the animals (P<0.05), but were positively correlated with the number of migrated Kupffer cells, the density of lysosomes and the mRNA expression level of TNF-α (P<0.05). TLR2 and TLR4 in Kupffer cells may play important roles in the chronic process of hepatic pathological changes in tree shrews infected with HBV through their influence on the function of Kupffer cells.

Shades of Decay: The Meanings of Tooth Discoloration and Deterioration to Mexican Immigrant Caregivers of Young Children

PubMed Central

Masterson, Erin E.; Barker, Judith C.; Hoeft, Kristin S.; Hyde, Susan

2014-01-01

The objective of this article is to investigate parental understanding of tooth discoloration and decay and their related care seeking for young, Mexican-American children. The research design entailed semi-structured, face-to-face interviews conducted in Spanish with a convenience sample of 37 Mexican immigrant mothers of young children in a low-income urban neighborhood. Five major color terms – white, off-white, yellow, brown, and black – were used to describe tooth discoloration, the causes of which were mainly unrecognized or attributed to poor oral hygiene and exposure to sweet substances. Mothers also described three major levels of deterioration of the structural integrity of teeth due to caries, from stains to decayed portions to entirely rotten. A trend was observed between use of darker discoloration terms and extensive carious lesions. Teeth described as both dark in color and structurally damaged resulted in seeking of professional care. The paper concludes with the finding that Spanish terms used to describe tooth discoloration and carious lesions are broad and complex. Mexican immigrant mothers’ interpretations of tooth discoloration and decay may differ from dental professionals’ and result in late care seeking. Increased understanding between dental practitioners and caregivers is needed to create educational messages about the early signs of tooth decay. PMID:26279585

The role of potential mediators in racial inequalities in tooth loss: the Pró-Saúde study.

PubMed

Celeste, Roger Keller; Gonçalves, Letícia Gomes; Faerstein, Eduardo; Bastos, João Luiz

2013-12-01

To assess the relation between race and tooth loss, as well as the influence of socioeconomic factors, health behaviours, routine dental care and self-reported discrimination on this association. This is a cross-sectional study with data collected from the baseline of the Pró-Saúde Study (Rio de Janeiro/Brazil), among 3253 civil servants in 1999-2001. Race was measured as self-reported skin colour (Black/Brown/White). The outcome was self-reported tooth loss, measured in four ordered categories (none/one or few/many/all or almost all). Three mediating pathways were explored between race and tooth loss. The first included self-reported discrimination assessed with a five-item scale. The second pathway included behavioural factors: routine dental care, marital status, smoking and alcohol consumption. The third considered socioeconomic factors: income, education, maternal education and early life poverty. Confounding factors were age and sex. Statistical analyses were carried out with ordinal logistic regression. Absence of all or almost all teeth was reported by 8% of respondents. White individuals comprised 53% of the population, followed by Browns (26%) and Blacks (22%). After adjustment, Blacks had an odds ratio of being in a higher category of missing teeth equal to 1.39 (95% CI 1.12-1.72), and Browns, 1.33 (95% CI 1.10-1.60), when compared to Whites. Age, sex and socioeconomic variables explained most of racial inequalities in tooth loss, while behavioural and discrimination variables contributed very little. Behavioural and socioeconomic variables were associated with tooth loss, while discrimination was not. No statistically significant interactions were found. There is an association between race and tooth loss that is mainly explained by current and early life socioeconomic variables, but not by behavioural factors and self-reported discrimination. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Microcomputed tomography evaluation of white spot lesion remineralization with various procedures.

PubMed

Kucuk, Eyup Burak; Malkoc, Siddik; Demir, Abdullah

2016-09-01

The aim of this study was to use microcomputed tomography to evaluate the effects on white spot lesions of 3 remineralizing agents compared with artificial saliva (Inonu University, Malatya, Turkey). The agents were GC Tooth Mousse (GC International, Itabashi-ku, Tokyo, Japan), 50-ppm sodium fluoride solution (Inonu University, Malatya, Turkey), and Clinpro 5000 (3M ESPE Dental Products (St Paul, Minn). The experimental and control teeth were stored in artificial saliva. Forty-four extracted premolars were divided into 4 groups of 11 teeth each (3 experimental groups and 1 control group). After white spot lesions were created on the teeth, a remineralizing agent was applied. Microcomputed tomography scanning was performed at the following times: T0 (sound enamel), T1 (day 0, when the white spot lesion was formed), T2 (day 15), and T3 (day 30). Volume, depth, surface area, and mineral density changes of the white spot lesions were evaluated at different time points using CTAn software (SkyScan; Bruker, Kontich, Belgium). GC Tooth Mousse and Clinpro 5000 improved all measurements after 30 days. However, Clinpro 5000 was not as effective in reducing lesion depth as it was in the other parameters. The artificial saliva group and the 50-ppm sodium fluoride solution did not show significant effects in the regression of the white spot lesions at the end of the 30-day experiment. GC Tooth Mousse and Clinpro 5000 were more effective in remineralization of white spot lesions than sodium fluoride solution and artificial saliva. They can be preferred for use clinically. Microcomputed tomography is a novel and effective method that shows promise in accurately evaluating white spot lesions and remineralization. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Establishment of the Tree Shrew as an Alcohol-Induced Fatty Liver Model for the Study of Alcoholic Liver Diseases

PubMed Central

Xing, Huijie; Jia, Kun; He, Jun; Shi, Changzheng; Fang, Meixia; Song, Linliang; Zhang, Pu; Zhao, Yue; Fu, Jiangnan; Li, Shoujun

2015-01-01

Currently, the pathogenesis of alcoholic liver diseases (ALDs) is not clear. As a result, there is no effective treatment for ALDs. One limitation is the lack of a suitable animal model for use in studying ALDs. The tree shrew is a lower primate animal, characterized by a high-alcohol diet. This work aimed to establish a fatty liver model using tree shrews and to assess the animals’ suitability for the study of ALDs. Tree shrews were treated with alcohol solutions (10% and 20%) for two weeks. Hemophysiology, blood alcohol concentrations (BACs), oxidative stress factors, alcohol metabolic enzymes and hepatic pathology were checked and assayed with an automatic biochemical analyzer, enzyme-linked immunosorbent assay (ELISA), western blot, hematoxylin-eosin (HE) staining and oil red O staining, and magnetic resonance imaging (MRI). Compared with the normal group, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), total cholesterol (TC), triglyceride (TG), reactive oxygen species (ROS), and malondialdehyde (MDA) were significantly enhanced in alcohol-treated tree shrews. However, the activity of reduced glutathione hormone (GSH) and superoxide dismutase (SOD) declined. Notable changes in alcohol dehydrogenase(ADH1), aldehyde dehydrogenase(ALDH2), CYP2E1, UDP-glucuronosyl transferase 1A1 (UGT1A1) and nuclear factor erythroid-related factor 2 (Nrf2) were observed. HE and oil red O staining showed that hepatocyte swelling, hydropic degeneration, and adipohepatic syndrome occurred in the tree shrews. Alcohol can induce fatty liver-like pathological changes and result in alterations in liver function, oxidative stress factors, alcohol metabolism enzymes and Nrf2. Therefore, the established fatty liver model of tree shrews induced by alcohol should be a promising tool for the study of ALDs. PMID:26030870

Effects of late quaternary climate change on Palearctic shrews.

PubMed

Prost, Stefan; Klietmann, Johannes; van Kolfschoten, Thijs; Guralnick, Robert P; Waltari, Eric; Vrieling, Klaas; Stiller, Mathias; Nagel, Doris; Rabeder, Gernot; Hofreiter, Michael; Sommer, Robert S

2013-06-01

The Late Quaternary was a time of rapid climatic oscillations and drastic environmental changes. In general, species can respond to such changes by behavioral accommodation, distributional shifts, ecophenotypic modifications (nongenetic), evolution (genetic) or ultimately face local extinction. How those responses manifested in the past is essential for properly predicting future ones especially as the current warm phase is further intensified by rising levels of atmospheric carbon dioxide. Here, we use ancient DNA (aDNA) and morphological features in combination with ecological niche modeling (ENM) to investigate genetic and nongenetic responses of Central European Palearctic shrews to past climatic change. We show that a giant form of shrew, previously described as an extinct Pleistocene Sorex species, represents a large ecomorph of the common shrew (Sorex araneus), which was replaced by populations from a different gene-pool and with different morphology after the Pleistocene Holocene transition. We also report the presence of the cold-adapted tundra shrew (S. tundrensis) in Central Europe. This species is currently restricted to Siberia and was hitherto unknown as an element of the Pleistocene fauna of Europe. Finally, we show that there is no clear correlation between climatic oscillations within the last 50 000 years and body size in shrews and conclude that a special nonanalogous situation with regard to biodiversity and food supply in the Late Glacial may have caused the observed large body size. © 2013 Blackwell Publishing Ltd.

Comparison of risk factors for tooth loss between professional drivers and white-collar workers: an internet survey.

PubMed

Suzuki, Seitaro; Yoshino, Koichi; Takayanagi, Atsushi; Ishizuka, Yoichi; Satou, Ryouichi; Kamijo, Hideyuki; Sugihara, Naoki

2016-06-10

This cross-sectional study was conducted to examine tooth loss and associated factors among professional drivers and white-collar workers. The participants were recruited by applying screening procedures to a pool of Japanese registrants in an online database. The participants were asked to complete a self-reported questionnaire. A total of 592 professional drivers and 328 white-collar workers (male, aged 30 to 69 years) were analyzed. A multiple logistic regression analysis was performed to identify differences between professional drivers and white-collar workers. The results showed that professional drivers had fewer teeth than white-collar workers (odds ratio [OR], 1.74; 95% confidence interval [95% CI], 1.150-2.625). Moreover, a second multiple logistic regression analysis revealed that several factors were associated with the number of teeth among professional drivers: diabetes mellitus (OR, 2.68; 95% CI, 1.388-5.173), duration of brushing teeth (OR, 1.66; 95% CI, 1.066-2.572), frequency of eating breakfast (OR, 2.23; 95% CI, 1.416-3.513), frequency of eating out (OR, 1.70; 95% CI, 1.086-2.671) and smoking status (OR, 2.88; 95% CI, 1.388-5.964). These findings suggest that the lifestyles of professional drivers could be related to not only their general health status, but also tooth loss.

Orthodontic treatment of an unerupted mandibular canine tooth in a patient with mixed dentition: a case report.

PubMed

Dinoi, Maria Teresa; Marchetti, Enrico; Garagiola, Umberto; Caruso, Silvia; Mummolo, Stefano; Marzo, Giuseppe

2016-06-10

The aim of this case report was to describe the surgical-orthodontic treatment of an unerupted mandibular canine tooth in a 9-year-old girl. A 9-year-old white girl presented with an unerupted right mandibular canine tooth. Combined surgical-orthodontic treatment was performed to correct dental impaction and to achieve good aesthetic and functional results. Orthodontic treatment achieved all of the required objectives.

Long-term data from a small mammal community reveal loss of diversity and potential effects of local climate change.

PubMed

Santoro, Simone; Sanchez-Suarez, Cristina; Rouco, Carlos; Palomo, L Javier; Fernández, M Carmen; Kufner, Maura B; Moreno, Sacramento

2017-10-01

Climate change affects distribution and persistence of species. However, forecasting species' responses to these changes requires long-term data series that are often lacking in ecological studies. We used 15 years of small mammal trapping data collected between 1978 and 2015 in 3 areas at Doñana National Park (southwest Spain) to (i) describe changes in species composition and (ii) test the association between local climate conditions and size of small mammal populations. Overall, 5 species were captured: wood mouse Apodemus sylvaticus , algerian mouse Mus spretus , greater white-toothed shrew Crocidura russula , garden dormouse Eliomys quercinus , and black rat Rattus rattus . The temporal pattern in the proportion of captures of each species suggests that the small mammal diversity declined with time. Although the larger species (e.g., E. quercinus ), better adapted to colder climate, have disappeared from our trapping records, M. spretus , a small species inhabiting southwest Europe and the Mediterranean coast of Africa, currently is almost the only trapped species. We used 2-level hierarchical models to separate changes in abundance from changes in probability of capture using records of A. sylvaticus in all 3 areas and of M. spretus in 1. We found that heavy rainfall and low temperatures were positively related to abundance of A. sylvaticus , and that the number of extremely hot days was negatively related to abundance of M. spretus . Despite other mechanisms are likely to be involved, our findings support the importance of climate for the distribution and persistence of these species and raise conservation concerns about potential cascading effects in the Doñana ecosystem.

Development and characterization of 21 polymorphic microsatellite markers for the barren-ground shrew, Sorex ugyunak (Mammalia: Sorcidae), through next-generation sequencing, and cross-species amplification in the masked shrew, S. cinereus

USGS Publications Warehouse

Sonsthagen, Sarah A.; Sage, G. Kevin; Fowler, Megan C.; Hope, Andrew G.; Cook, J.A.; Talbot, Sandra L.

2013-01-01

We used next generation shotgun sequencing to develop 21 novel microsatellite markers for the barren-ground shrew (Sorex ugyunak), which were polymorphic among individuals from northern Alaska. The loci displayed moderate allelic diversity (averaging 6.81 alleles per locus) and heterozygosity (averaging 70 %). Two loci deviated from Hardy–Weinberg equilibrium (HWE) due to heterozygote deficiency. While the population did not deviate from HWE overall, it showed significant linkage disequilibrium suggesting this population is not in mutation-drift equilibrium. Nineteen of 21 loci were polymorphic in masked shrews (S. cinereus) from interior Alaska and exhibited linkage equilibrium and HWE overall. All loci yielded sufficient variability for use in population studies.

Bleachorexia-an addictive behavior to tooth bleaching: a case report.

PubMed

Lee, Denzel Kun-Tsung; Kastl, Cameron; Chan, Daniel C N

2018-05-01

Bleachorexia, addiction to tooth bleaching, is a behavioral disorder similar to anorexia. The patient feels that their teeth are always not white enough and continues to use whiteners to obtain a "perfect" smile. Such behavior falls under the category of a body dysmorphic disorder and may need medical counseling.

Racial/ethnic variations in associations between socioeconomic factors and tooth loss.

PubMed

Jimenez, Monik; Dietrich, Thomas; Shih, Mei-Chiung; Li, Yi; Joshipura, Kaumudi J

2009-06-01

To compare the associations between socioeconomic factors and tooth loss among White, Black, and Mexican-American people. Analyses were conducted on 16,821 adults, using data from the National Health and Nutrition Examination Survey-III. Age- and multivariate-adjusted negative binomial regressions were used to explore the relation of socioeconomic factors, region of residence, gender, and foreign birth with the number of missing teeth. Effect modification by race/ethnicity was assessed by the inclusion of interaction terms. In multivariate-adjusted analyses, non-Hispanic White people with 9-12 years of education exhibited 71% higher mean number of missing teeth than those with >12 years of education [incidence rate ratio (IRR) = 1.71, 95% confidence interval (CI): 1.52-1.92]. Education was unrelated to the number of teeth among non-Hispanic Black people (IRR = 1.16; 95% CI: 1.00-1.35) or Mexican-Americans (IRR = 1.10, 95% CI: 0.93-1.31). The poorest White people exhibited 39% more missing teeth, on average, than the most affluent White people, but no association between poverty and number of teeth was observed among Black or Mexican-American people. The associations between socioeconomic factors and tooth loss vary across race/ethnicity. This suggests that the health benefits associated with high socioeconomic status are not equally shared across racial/ethnic groups.

Efficacy of whitening oral rinses and dentifrices on color stability of bleached teeth

PubMed Central

Karadas, Muhammet

2015-01-01

Abstract Objective: This study aimed to evaluate the effect of whitening toothpastes and mouthrinses on the color stability of teeth bleached with 16% carbamide peroxide (CP) after immersion in coffee solution. Materials and methods: Specimens obtained from bovine incisors were bleached with 16% CP for 14 days. After bleaching, the specimens were stained in coffee solution for 24 h and randomly divided into eight groups according to the following products (n = 10): distilled water (control group, DW), Scope White mouthrinse (SW), Crest 3D White mouthrinse (CWR), Crest 3D White toothpaste (CWT), Crest 3D White toothpaste and Crest 3D White mouthrinse (CWT + CWR), Listerine Whitening toothpaste (LWT), Listerine Whitening mouthrinse (LWR), and Listerine Whitening mouthrinse and Listerine Whitening toothpaste (LWR + LWT). Color measurements were conducted using a spectrophotometer. The data were assessed by analysis of variance for repeated measures and Tukey’s multiple comparison test (p < 0.05). Results: Immersion in coffee solution after bleaching caused perceptible staining on tooth specimens (ΔE > 3.46). The whitening effect of CWR on teeth stained after bleaching was significantly greater than that in the other groups (p < 0.001). Tooth whitening (ΔE) in each group showed no significant difference from 6 to 12 weeks (p > 0.05). The combination of mouthrinse and toothpaste did not increase the degree of tooth whitening. Conclusion: Whitening mouthrinse and toothpaste had similar effects on the control group in terms of whitening of teeth stained after bleaching. Nevertheless, Crest 3D White mouthrinse produced the greatest recovery whitening effect among all the products tested. PMID:28642898

Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change

USGS Publications Warehouse

Hope, Andrew G.; Waltari, Eric; Fedorov, Vadim B.; Goropashnaya, Anna V.; Talbot, Sandra; Cook, Joseph A.

2011-01-01

Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes.

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus) in Bangladesh.

PubMed

Rahman, Mizanur; Islam, Shariful; Masuduzzaman, Md; Alam, Mahabub; Chawdhury, Mohammad Nizam Uddin; Ferdous, Jinnat; Islam, Md Nurul; Hassan, Mohammad Mahmudul; Hossain, Mohammad Alamgir; Islam, Ariful

2018-04-01

Asian house shrew ( Suncus murinus ), a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI) helminths in free-ranging Asian house shrew ( S. murinus ) in Bangladesh. A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. The overall prevalence of GI helminth was 77.9% (67/86), with six species including nematodes (3), cestodes (2), and trematodes (1). Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp.(59%), followed by Strongyloides spp.(17%), Capillaria spp. (10%), Physaloptera spp. (3%), and Echinostoma spp.(3%). The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp.) in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling) in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis.

Two new species of shrews (Soricidae) from the western highlands of Guatemala

USGS Publications Warehouse

Woodman, Neal

2010-01-01

The broad-clawed shrews (Soricomorpha: Soricidae: Cryptotis) encompass a clade of 5 species—Cryptotis alticolus (Merriam), C. goldmani (Merriam), C. goodwini Jackson, C. griseoventris Jackson, and C. peregrinus (Merriam)—that is known collectively as the Cryptotis goldmani group and is characterized by broadened forefeet, elongated and broadened fore claws, and broadened humeri. These shrews are distributed in highland regions from central Mexico to Honduras. Two broad-clawed shrews, C. goodwini and C. griseoventris, occur in southern Mexico and Guatemala and are presumed sister species whose primary distinguishing feature is the larger size of C. goodwini. In an investigation of variation within and between these 2 species, I studied characteristics of the postcranial skeleton. Statistical analyses of a variety of character suites indicate that the forelimb morphology in this group exhibits less intraspecific variation and greater interspecific variation than cranio-mandibular morphology, although most skull characters support groupings based on forelimb characters. Together, these characters define 4 distinct groups among the specimens examined. C. griseoventris is restricted to the northern highlands of Chiapas, Mexico, and C. goodwini occurs in the southern highlands of Chiapas and Guatemala. Herein, I describe 2 new species of broad-clawed shrews from the Sierra de los Cuchumatanes, Guatemala.

Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change

USGS Publications Warehouse

Hope, Andrew G.; Waltari, Eric; Fedorov, V.B.; Goropashnaya, A.V.; Talbot, Sandra; Cook, Joseph A.

2014-01-01

Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes.

Look What the Cat Brought In.

ERIC Educational Resources Information Center

Erslev, Carole

1984-01-01

The small, uneaten, slate-gray, pointed-nose animal that is distasteful to the cat because of foul-tasting scent glands is the shrew. Describes the short-tailed shrew's physical characteristics, lifespan, habitat, eating habits, and senses. (ERB)

The Study on Grinding Ratio in Form Grinding with White Fused Alumina (WA) Grinding Wheels

NASA Astrophysics Data System (ADS)

Junming, Wang; Jiong, Wang; Deyuan, Lou

2018-03-01

The study is carried out based on an experiment of form grinding spur rack with white fused alumina (WA) grinding wheels. In the experiment, SOV-3020A type tri-axial image mapper is utilized to measure the profile of the tooth space in the rack, and the curve equations between the sectional area of the tooth space and the tooth sequence under different grinding depths are established by nonlinear curve regress using software of origin8.0. Then, it deduces the prediction equations for current grinding ratio and cumulative grinding ratio under different grinding depths. The result shows that the grinding ratio is exponential decline relationship with the increase of the number of the tooth to be ground under the same grinding depth, and the decline speed is fast in the initial stage. With the increase of grinding depth, the grinding ratio increases gradually. The cumulative grinding ratio is about twice as high as the current grinding ratio. Thus, large grinding depth is generally used in rough grinding to improve grinding efficiency.

Evaluation of the remineralization potential of amorphous calcium phosphate and fluoride containing pit and fissure sealants using scanning electron microscopy.

PubMed

Choudhary, Prashant; Tandon, Shobha; Ganesh, M; Mehra, Anshul

2012-01-01

To evaluate the remineralization potential of Amorphous Calcium Phosphate (ACP) and Fluoride containing pit and Fissure Sealants using Scanning Electron Microscopy. Thirty maxillary first premolars were divided into three groups of ten each and were randomly selected for ACP containing (Aegis- Opaque White, Bosworth Co. Ltd.), Fluoride containing (Teethmate F1 Natural Clear, Kuraray Co. Ltd.), resin based (Concise- Opaque White, 3M ESPE Co. Ltd.) pit and fissure sealant applications. The Concise group served as a control. The teeth weresubjected to the pH-cycling regimen for a period of two weeks. After two weeks, the teeth were sectioned bucco-lingually into 4mm sections and were observed under Scanning Electron Microscope at 50X, 250X, 500X, 1000X and 1500X magnifications. The qualitative changes at the tooth surface and sealant interface were examined and presence of white zone at the interface was considered positive for remineralization. Both ACP containing (Aegis) and Fluoride containing (Teethmate F1) group showed white zone at the tooth surface-sealant interface. The resin based group (Concise) showed regular interface between the sealant and the tooth structure, but no clear cut white zone was observed. Both, Aegis and Teethmate F1 have the potential to remineralize. Release of Amorphous Calcium Phosphate molecules in Aegis group and formation of Fluoroapetite in Teethmate F1 group, were probably responsible for the remineralization.

Structure of corneal layers, collagen fibrils, and proteoglycans of tree shrew cornea.

PubMed

Almubrad, Turki; Akhtar, Saeed

2011-01-01

The stroma is the major part of the cornea, in which collagen fibrils and proteoglycans are distributed uniformly. We describe the ultrastructure of corneal layers, collagen fibrils (CF), and proteoglycans (PGs) in the tree shrew cornea. Tree shrew corneas (5, 6, and 10 week old animals) and normal human corneas (24, 25, and 54 years old) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in a sodium acetate buffer. The tissue was processed for electron microscopy. The 'iTEM Olympus Soft Imaging Solutions GmbH' program was used to measure the corneal layers, collagen fibril diameters and proteoglycan areas. The tree shrew cornea consists of 5 layers: the epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The epithelium was composed of squamous cells, wing cells and basal cells. The Bowman's layer was 5.5±1.0 µm thick and very similar to a normal human Bowman's layer. The stroma was 258±7.00 µm thick and consisted of collagen fibril lamellae. The lamellae were interlaced with one another in the anterior stroma, but ran parallel to one another in the middle and posterior stroma. Collagen fibrils were decorated with proteoglycan filaments with an area size of 390 ±438 nm(2). The collagen fibril had a minimum diameter of 39±4.25 nm. The interfibrillar spacing was 52.91±6.07 nm. Within the collagen fibrils, very small electron-dense particles were present. The structure of the tree shrew cornea is very similar to that of the normal human cornea. As is the case with the human cornea, the tree shrew cornea had a Bowman's layer, lamellar interlacing in the anterior stroma and electron-dense particles within the collagen fibrils. The similarities of the tree shrew cornea with the human cornea suggest that it could be a good structural model to use when studying changes in collagen fibrils and proteoglycans in non-genetic corneal diseases, such as ectasia caused after LASIK (laser-assisted in situ keratomileusis).

The Discoloration effect of White Mineral Trioxide Aggregate (WMTA), Calcium Enriched Mixture (CEM), and Portland Cement (PC) on Human Teeth.

PubMed

Salem-Milani, Amin; Ghasemi, Saeede; Rahimi, Saeed; Ardalan-Abdollahi, Amir; Asghari-Jafarabadi, Mohammad

2017-12-01

The aim of this study was to evaluate the discoloration induced by CEM cement, Portland cement (PC) and MTA mixed with propylene glycol (MTA-PG) in comparison to White MTA. Ninety extracted premolar and canine teeth were resected 2 mm below the CEJ. The coronal part of crown was prepared with peeso reamer and Gates-Glidden drills, and the specimens were randomly divided into 4 experimental (n=20) and one control (n=10) groups. The tooth crowns in experimental groups 1 to 4 were filled with White MTA, PC, CEM cement and MTA-PG, respectively; and in group 5, the teeth were kept empty. After incubation, digital photographs of teeth were acquired at 4 time points (before, immediately after placing the materials, 3 and 6 months afterwards). Images were transferred to Adobe Photoshop CS4 and CIE L*a*b color space was used for tooth shade assessment. One-Way ANOVA and One-Sample t-test were used to compare discoloration of teeth between groups. Significant statistical discoloration was only observed in the cervical one third of all groups at each time points (except between 3 and 6 months). Tooth discoloration was greatest in PC and lower in MTA and MTA-PG at the end of 6 months. The tooth discoloration between immediately and 3 months after placing the materials had significant difference only between MTA and PC; and also the tooth discoloration between immediately and 6 months after placing the materials was observed only between PC and MTA, and PC and MTA-PG. All of the experimental biomaterials caused tooth discoloration after 6 months, of those, PC had the most and MTA and MTA-PG had the least discoloration effect. Key words: Mineral trioxide aggregate (MTA). Calcium enriched mixture (CEM). Propylene glycol. Portland cement.

Comparison of laser and power bleaching techniques in tooth color change.

PubMed

Fekrazad, Reza; Alimazandarani, Shervin; Kalhori, Katayoun Am; Assadian, Hadi; Mirmohammadi, Seyed-Mahdi

2017-04-01

Laser-assisted bleaching uses laser beam to accelerate release of free radicals within the bleaching gel to decrease time of whitening procedure. The aim of this study was to compare the efficacy of power bleaching using Opalescence Xtra Boost® and laser bleaching technique using LaserSmile gel and diode laser as an activator in their tooth whitening capacity. Student t test showed that the laser bleaching group significantly outperformed the power bleaching group in changing ∆E ( p =0.977). Similarly, while comparing the groups in changing ∆L, the laser bleaching group indicated significantly superior results ( p =0.953). Statistical data from student t test while comparing the groups in changing the parameter of yellowness indicated that samples in laser bleaching group underwent a more significant reduction than power-bleached samples ( p =0.85). Correspondingly, changes in whiteness were statistically tested through student t test, showing that laser bleaching technique increased whiteness of the samples significantly more than those treated by power bleaching ( p =0.965). The digital color evaluation data was in accordance with spectrophotometry and showed that laser bleaching outperformed power bleaching technique. Both techniques were able to increase whiteness and decrease yellowness ratio of the samples. ΔE decrease for laser bleaching and power bleaching groups were 3.05 and 1.67, respectively. Tooth color change in laser bleaching group was 1.88 times more than that of power bleaching group ( p <0.001). It could be concluded that under the conditions of this study, both laser-assisted and power bleaching techniques were capable of altering tooth color change, but laser bleaching was deemed a more efficient technique in this regard. Key words: Laser, power bleaching, tooth color introduction.

Differences in the intensity of light-induced fluorescence emitted by resin composites.

PubMed

Kim, Bo-Ra; Kang, Si-Mook; Kim, Gyung-Min; Kim, Baek-Il

2016-03-01

The aims of this study were to compare the intensities of fluorescence emitted by different resin composites as detected using quantitative light-induced fluorescence (QLF) technology, and to compare the fluorescence intensity contrast with the color contrast between a restored composite and the adjacent region of the tooth. Six brands of light-cured resin composites (shade A2) were investigated. The composites were used to prepare composite discs, and fill holes that had been prepared in extracted human teeth. White-light and fluorescence images of all specimens were obtained using a fluorescence camera based on QLF technology (QLF-D) and converted into 8-bit grayscale images. The fluorescence intensity of the discs as well as the fluorescence intensity contrast and the color contrast between the composite restoration and adjacent tooth region were calculated as grayscale levels. The grayscale levels for the composite discs differed significantly with the brand (p<0.001): DenFil (10.84±0.35, mean±SD), Filtek Z350 (58.28±1.37), Premisa (156.94±1.58), Grandio (177.20±0.81), Charisma (207.05±0.77), and Gradia direct posterior (211.52±1.66). The difference in grayscale levels between a resin restoration and the adjacent tooth was significantly greater in fluorescence images for each brand than in white-light images, except for the Filtek Z350 (p<0.05). However, the Filtek Z350 restoration was distinguishable from the adjacent tooth in a fluorescence image. The intensities of fluorescence detected from the resin composites varied. The differences between the composite and adjacent tooth were greater for the fluorescence intensity contrast than for the colors observed in the white-light images. Copyright © 2016 Elsevier B.V. All rights reserved.

Clinical study of tooth shade lightening from dentist-supervised, patient-applied treatment with two 10% carbamide peroxide gels.

PubMed

Cibirka, R M; Myers, M; Downey, M C; Nelson, S K; Browning, W D; Hawkins, I K; Dickinson, G L

1999-01-01

Prescribed, patient-applied tooth lightening agents, or nightguard vital bleaching, typically utilizes a 10% carbamide peroxide agent applied during nocturnal hours. The purpose of this randomized double-blind study was to compare the amount of tooth color change in two groups of subjects using dentist-supervised, patient-applied 10% carbamide peroxide gel. One group used Opalescence (Ultradent Products Inc., South Jordan, Utah) and the other NiteWhite Excel (Discus Dental, Inc., Los Angeles, California). Evaluation of tooth color for the six maxillary anterior teeth was done using a Vita shade guide at baseline, 1, 2, and 4 weeks. Subjects were instructed to apply the gel nocturnally using a custom-made soft tray 8 hours per day for 2 weeks. The 16 tabs of the shade guide were ranked according to value from darkest to lightest. The number (1-16) that correlated to the shade tab selected as the match for each tooth was the outcome variable. A Kruskal-Wallis one way analysis of variance on ranks was used. The test revealed no statistically significant difference between Opalescence and NiteWhite Excel for lightening the teeth (p = .807). The color change was still significant after 2 weeks without further bleaching activity. The baseline evaluation of the maxillary incisors and canines for all subjects, regardless of group, demonstrated a significant shade difference, with the canines being darker. This difference was not seen after 2 weeks of active bleaching or at the 4-week evaluation. In this study comparing bleaching products, patients using Opalescence and NiteWhite Excel experienced a significant change in the color of their teeth relative to baseline values after 2 weeks of active treatment.

Digital soil map of the Ussuri River basin

NASA Astrophysics Data System (ADS)

Bugaets, A. N.; Pschenichnikova, N. F.; Tereshkina, A. A.; Krasnopeev, S. M.; Gartsman, B. I.; Golodnaya, O. M.; Oznobikhin, V. I.

2017-08-01

On the basis of digital soil, topographic, and geological maps; raster topography model; forestry materials; and literature data, the digital soil map of the Ussuri River basin (24400 km2) was created on a scale of 1: 100000. To digitize the initial paper-based maps and analyze the results, an ESRI ArcGIS Desktop (ArcEditor) v.10.1 (http://www.esri.com) and an open-code SAGA GIS v.2.3 (System for Automated Geoscientific Analyses, http://www.saga-gis.org) were used. The spatial distribution of soil areas on the obtained digital soil map is in agreement with modern cartographic data and the SRTM digital elevation model (SRTM DEM). The regional soil classification developed by G.I. Ivanov was used in the legend to the soil map. The names of soil units were also correlated with the names suggested in the modern Russian soil classification system. The major soil units on the map are at the soil subtypes that reflect the entire vertical spectrum of soils in the south of the Far East of Russia (Primorye region). These are mountainous tundra soils, podzolic soils, brown taiga soils, mountainous brown forest soils, bleached brown soils, meadow-brown soils, meadow gley soils, and floodplain soils). With the help of the spatial analysis function of GIS, the comparison of the particular characteristics of the soil cover with numerical characteristics of the topography, geological composition of catchments, and vegetation cover was performed.

Colonization of Ireland: revisiting 'the pygmy shrew syndrome' using mitochondrial, Y chromosomal and microsatellite markers.

PubMed

McDevitt, A D; Vega, R; Rambau, R V; Yannic, G; Herman, J S; Hayden, T J; Searle, J B

2011-12-01

There is great uncertainty about how Ireland attained its current fauna and flora. Long-distance human-mediated colonization from southwestern Europe has been seen as a possible way that Ireland obtained many of its species; however, Britain has (surprisingly) been neglected as a source area for Ireland. The pygmy shrew has long been considered an illustrative model species, such that the uncertainty of the Irish colonization process has been dubbed 'the pygmy shrew syndrome'. Here, we used new genetic data consisting of 218 cytochrome (cyt) b sequences, 153 control region sequences, 17 Y-intron sequences and 335 microsatellite multilocus genotypes to distinguish between four possible hypotheses for the colonization of the British Isles, formulated in the context of previously published data. Cyt b sequences from western Europe were basal to those found in Ireland, but also to those found in the periphery of Britain and several offshore islands. Although the central cyt b haplotype in Ireland was found in northern Spain, we argue that it most likely occurred in Britain also, from where the pygmy shrew colonized Ireland as a human introduction during the Holocene. Y-intron and microsatellite data are consistent with this hypothesis, and the biological traits and distributional data of pygmy shrews argue against long-distance colonization from Spain. The compact starburst of the Irish cyt b expansion and the low genetic diversity across all markers strongly suggests a recent colonization. This detailed molecular study of the pygmy shrew provides a new perspective on an old colonization question.

Colonization of Ireland: revisiting ‘the pygmy shrew syndrome' using mitochondrial, Y chromosomal and microsatellite markers

PubMed Central

McDevitt, A D; Vega, R; Rambau, R V; Yannic, G; Herman, J S; Hayden, T J; Searle, J B

2011-01-01

There is great uncertainty about how Ireland attained its current fauna and flora. Long-distance human-mediated colonization from southwestern Europe has been seen as a possible way that Ireland obtained many of its species; however, Britain has (surprisingly) been neglected as a source area for Ireland. The pygmy shrew has long been considered an illustrative model species, such that the uncertainty of the Irish colonization process has been dubbed ‘the pygmy shrew syndrome'. Here, we used new genetic data consisting of 218 cytochrome (cyt) b sequences, 153 control region sequences, 17 Y-intron sequences and 335 microsatellite multilocus genotypes to distinguish between four possible hypotheses for the colonization of the British Isles, formulated in the context of previously published data. Cyt b sequences from western Europe were basal to those found in Ireland, but also to those found in the periphery of Britain and several offshore islands. Although the central cyt b haplotype in Ireland was found in northern Spain, we argue that it most likely occurred in Britain also, from where the pygmy shrew colonized Ireland as a human introduction during the Holocene. Y-intron and microsatellite data are consistent with this hypothesis, and the biological traits and distributional data of pygmy shrews argue against long-distance colonization from Spain. The compact starburst of the Irish cyt b expansion and the low genetic diversity across all markers strongly suggests a recent colonization. This detailed molecular study of the pygmy shrew provides a new perspective on an old colonization question. PMID:21673740

Tooth whitening evaluation of blue covarine containing toothpastes.

PubMed

Tao, Danying; Smith, Richard N; Zhang, Qiong; Sun, Jianing N; Philpotts, Carole J; Ricketts, Stephen R; Naeeni, Mojgan; Joiner, Andrew

2017-12-01

To measure the tooth whitening effects delivered immediately after brushing with silica-based toothpastes containing blue covarine in vitro and in vivo. Salivary pellicle coated human extracted teeth were brushed with either a slurry of a toothpaste containing blue covarine (BC), a formulation containing an increased level of blue covarine (BC+) or a negative control toothpaste containing no blue covarine. The colour of the specimens were measured in vitro using either a Minolta chromameter or a VITA Easyshade spectrophotometer, before and after brushing and changes in CIELAB values and tooth Whiteness Index (WIO) values calculated. In a double-blind cross-over clinical study, subjects brushed with either BC or BC+ toothpaste and tooth colour changes were measured with a digital image analysis system. The in vitro studies demonstrated that toothpastes containing blue covarine gave a significantly (p<0.05) greater change in b* and WIO values than the negative control toothpaste; the BC+ toothpaste gave a significantly greater increase in b* and WIO values than the BC toothpaste, and BC+ gave a significant increase in shade change versus the negative control. Clinical results showed that BC and BC+ gave a significant reduction in b* (p<0.0001) and increase in WIO (p<0.0001) from baseline indicating significant tooth whitening had occurred. The parameter changes were significantly greater when brushing with the BC+ toothpaste than with the BC toothpaste (WIO p=0.006; b* p=0.013). Toothpastes containing blue covarine gave a statistically significant reduction in tooth yellowness and improvement in tooth whiteness immediately after brushing in both in vitro and clinical studies. In addition, the higher concentration blue covarine toothpaste gave statistically significant greater tooth whitening benefits than the lower concentration blue covarine toothpaste. The silica-based toothpastes containing blue covarine evaluated in the current study gave tooth whitening benefits immediately after one brush. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trap geometry in three giant montane pitcher plant species from Borneo is a function of tree shrew body size.

PubMed

Chin, Lijin; Moran, Jonathan A; Clarke, Charles

2010-04-01

*Three Bornean pitcher plant species, Nepenthes lowii, N. rajah and N. macrophylla, produce modified pitchers that 'capture' tree shrew faeces for nutritional benefit. Tree shrews (Tupaia montana) feed on exudates produced by glands on the inner surfaces of the pitcher lids and defecate into the pitchers. *Here, we tested the hypothesis that pitcher geometry in these species is related to tree shrew body size by comparing the pitcher characteristics with those of five other 'typical' (arthropod-trapping) Nepenthes species. *We found that only pitchers with large orifices and lids that are concave, elongated and oriented approximately at right angles to the orifice capture faeces. The distance from the tree shrews' food source (that is, the lid nectar glands) to the front of the pitcher orifice precisely matches the head plus body length of T. montana in the faeces-trapping species, and is a function of orifice size and the angle of lid reflexion. *Substantial changes to nutrient acquisition strategies in carnivorous plants may occur through simple modifications to trap geometry. This extraordinary plant-animal interaction adds to a growing body of evidence that Nepenthes represents a candidate model for adaptive radiation with regard to nitrogen sequestration strategies.

Isolation and characterization of a novel arenavirus harbored by Rodents and Shrews in Zhejiang province, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kun; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou; Lin, Xian-Dan

2015-02-15

To determine the biodiversity of arenaviruses in China, we captured and screened rodents and shrews in Wenzhou city, Zhejiang province, a locality where hemorrhagic fever diseases are endemic in humans. Accordingly, arenaviruses were detected in 42 of 351 rodents from eight species, and in 12 of 272 Asian house shrews (Suncus murinus), by RT-PCR targeting the L segment. From these, a single arenavirus was successfully isolated in cell culture. The virion particles exhibited a typical arenavirus morphology under transmission electron microscopy. Comparison of the S and L segment sequences revealed high levels of nucleotide (>32.2% and >39.6%) and amino acidmore » (>28.8% and >43.8%) sequence differences from known arenaviruses, suggesting that it represents a novel arenavirus, which we designated Wenzhou virus (WENV). Phylogenetic analysis revealed that all WENV strains harbored by both rodents and Asian house shrews formed a distinct lineage most closely related to Old World arenaviruses. - Highlights: • A novel arenavirus (Wenzhou virus) was identified in Zhejiang province, China. • The virus is highly circulating in five species of rats and one species of shrews • More efforts are needed to infer whether it is pathogenic to humans or not.« less

Prevalence and diversity of gastrointestinal helminths in free-ranging Asian house shrew (Suncus murinus) in Bangladesh

PubMed Central

Rahman, Mizanur; Islam, Shariful; Masuduzzaman, Md.; Alam, Mahabub; Chawdhury, Mohammad Nizam Uddin; Ferdous, Jinnat; Islam, Md. Nurul; Hassan, Mohammad Mahmudul; Hossain, Mohammad Alamgir; Islam, Ariful

2018-01-01

Background and Aim Asian house shrew (Suncus murinus), a widely distributed small mammal in the South Asian region, can carry helminths of zoonotic importance. The aim of the study was to know the prevalence and diversity of gastrointestinal (GI) helminths in free-ranging Asian house shrew (S. murinus) in Bangladesh. Materials and Methods A total of 86 Asian house shrews were captured from forest areas and other habitats of Bangladesh in 2015. Gross examination of the whole GI tract was performed for gross helminth detection, and coproscopy was done for identification of specific eggs or larvae. Results The overall prevalence of GI helminth was 77.9% (67/86), with six species including nematodes (3), cestodes (2), and trematodes (1). Of the detected helminths, the dominant parasitic group was from the genus Hymenolepis spp.(59%), followed by Strongyloides spp.(17%), Capillaria spp. (10%), Physaloptera spp. (3%), and Echinostoma spp.(3%). Conclusion The finding shows that the presence of potential zoonotic parasites (Hymenolepis spp. and Capillaria spp.) in Asian house shrew is ubiquitous in all types of habitat (forest land, cropland and dwelling) in Bangladesh. Therefore, further investigation is crucial to examine their role in the transmission of human helminthiasis. PMID:29805224

Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change

USGS Publications Warehouse

Hope, A.G.; Waltari, Eric; Fedorov, V.B.; Goropashnaya, A.V.; Talbot, S.L.; Cook, J.A.

2011-01-01

Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes. ?? 2011 Blackwell Publishing Ltd.

Forensic implications of the variation in morphology of marginal serrations on the teeth of the great white shark.

PubMed

Nambiar, P; Brown, K A; Bridges, T E

1996-06-01

The teeth of the Great White Shark have been examined to ascertain whether there is any commonality in the arrangement or number of the marginal serrations (peaks) or, indeed, whether individual sharks have a unique pattern of shapes or size of the peaks. The teeth of the White Shark are characteristic in size and shape with serrations along almost the entire mesial and distal margins. This study has revealed no consistent pattern of size or arrangement of the marginal serrations that was sufficiently characteristic within an individual shark to serve as a reliable index of identification of a tooth as originating from that particular shark. Nonetheless, the serrations are sufficiently distinctive to enable the potential identification of an individual tooth as having been the cause of a particular bitemark.

Contemporary permanent tooth dimensions, with comparisons to G.V. Black's data.

PubMed

Harris, Edward F; Burris, Benjamin G

2003-01-01

The tooth dimensions most commonly cited in the dental literature are those published by the famous restorative dentist G. V. Black late in the 19th century. We report here on the crown dimensions of a large series of contemporary North American Whites and show that Black's values differ significantly from modern values, but not in any consistent or predictable fashion. Black supplied no information about the nature of his sample. We suggest that it may be time to replace Black's data with modern tooth size standards.

Morphology and mechanics of the teeth and jaws of white-spotted bamboo sharks (Chiloscyllium plagiosum).

PubMed

Ramsay, Jason B; Wilga, Cheryl D

2007-08-01

The teeth of white-spotted bamboo sharks (Chiloscyllium plagiosum) are used to clutch soft-bodied prey and crush hard prey; however, the dual function is not evident from tooth morphology alone. Teeth exhibit characteristics that are in agreement with a clutching-type tooth morphology that is well suited for grasping and holding soft-bodied prey, but not for crushing hard prey. The dual role of this single tooth morphology is facilitated by features of the dental ligament and jaw joint. Tooth attachment is flexible and elastic, allowing movement in both sagittal and frontal planes. During prey capture spike-like tooth cusps pierce the flesh of soft prey, thereby preventing escape. When processing prey harder than the teeth can pierce the teeth passively depress, rotating inward towards the oral cavity such that the broader labial faces of the teeth are nearly parallel to the surface of the jaws and form a crushing surface. Movement into the depressed position increases the tooth surface area contacting prey and decreases the total stress applied to the tooth, thereby decreasing the risk of structural failure. This action is aided by a jaw joint that is ventrally offset from the occlusal planes of the jaws. The offset joint position allows many teeth to contact prey simultaneously and orients force vectors at contact points between the jaws and prey in a manner that shears or rolls prey between the jaws during a bite, thus, aiding in processing while reducing forward slip of hard prey from the mouth. Together the teeth, dental ligament, and jaws form an integrated system that may be beneficial to the feeding ecology of C. plagiosum, allowing for a diet that includes prey of varying hardness and elusiveness. (c) 2007 Wiley-Liss, Inc.

Improved Starch Digestion of Sucrase-deficient Shrews Treated With Oral Glucoamylase Enzyme Supplements.

PubMed

Nichols, Buford L; Avery, Stephen E; Quezada-Calvillo, Roberto; Kilani, Shadi B; Lin, Amy Hui-Mei; Burrin, Douglas G; Hodges, Benjamin E; Chacko, Shaji K; Opekun, Antone R; Hindawy, Marwa El; Hamaker, Bruce R; Oda, Sen-Ichi

2017-08-01

Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase-deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with congenital sucrase-isomaltase deficiency.Starch digestion is much more complex than sucrose digestion. Six enzyme activities, 2 α-amylases (Amy), and 4 mucosal α-glucosidases (maltases), including maltase-glucoamylase (Mgam) and sucrase-isomaltase (Si) subunit activities, are needed to digest starch to absorbable free glucose. Amy breaks down insoluble starch to soluble dextrins; mucosal Mgam and Si can either directly digest starch to glucose or convert the post-α-amylolytic dextrins to glucose. Starch digestion is reduced because of sucrase deficiency and oral glucoamylase enzyme supplement can correct the starch maldigestion. The aim of the present study was to measure glucogenesis in suc/suc shrews after feeding of starch and improvement of glucogenesis by oral glucoamylase supplements. Sucrase mutant (suc/suc) and heterozygous (+/suc) shrews were fed with C-enriched starch diets. Glucogenesis derived from starch was measured as blood C-glucose enrichment and oral recombinant C-terminal Mgam glucoamylase (M20) was supplemented to improve starch digestion. After feedings, suc/suc and +/suc shrews had different starch digestions as shown by blood glucose enrichment and the suc/suc had lower total glucose concentrations. Oral supplements of glucoamylase increased suc/suc total blood glucose and quantitative starch digestion to glucose. Sucrase deficiency, in this model of congenital sucrase-isomaltase deficiency, reduces blood glucose response to starch feeding. Supplementing the diet with oral recombinant glucoamylase significantly improved starch digestion in the sucrase-deficient shrew.

A comparative analysis of the potential of cannabinoids and ondansetron to suppress cisplatin-induced emesis in the Suncus murinus (house musk shrew).

PubMed

Kwiatkowska, Magdalena; Parker, Linda A; Burton, Page; Mechoulam, Raphael

2004-07-01

The 5-HT3 antagonist, ondansetron (OND), and the cannabinoid, delta9-tetrahydrocannabinol (delta9-THC), have been shown to interfere with emesis; however, their relative and/or combined effectiveness in suppressing vomiting produced by the chemotherapeutic agent, cisplatin, is unknown. To evaluate the potential of: 1) a broad range of doses of delta9-THC and OND to prevent cisplatin-induced vomiting and retching in the Suncus murinus (house musk shrew), 2) combined treatment with ineffective individual doses of delta9-THC and OND to prevent cisplatin-induced vomiting and retching, 3) the CB1 receptor antagonist, SR141716, to reverse the antiemetic effects of OND, and 4) cannabidiol (CBD), the principal non-psychoactive component of marijuana, to reverse cisplatin-induced vomiting in the shrew. Shrews were injected with various doses of OND (0.02-6.0 mg/kg), delta9-THC (1.25-10 mg/kg) and a combination of ineffective doses of each (0.02 mg/kg OND+1.25 mg/kg delta9-THC) prior to being injected with cisplatin (20 mg/kg) which induces vomiting. Shrews were also injected with CBD (5 mg/kg and 40 mg/kg) prior to an injection of cisplatin. OND and delta9-THC both dose-dependently suppressed cisplatin-induced vomiting and retching. Furthermore, a combined pretreatment of doses of the two drugs that were ineffective alone completely suppressed vomiting and retching. CBD produced a biphasic effect, suppressing vomiting at 5 mg/kg and potentiating it at 40 mg/kg. A low dose of the non-intoxicating cannabinoid CBD may be an effective anti-emetic treatment and combined doses of OND and delta9-THC that are ineffective alone suppresses cisplatin-induced emetic reactions in shrews.

Dynamic changes in DNA demethylation in the tree shrew (Tupaia belangeri chinensis) brain during postnatal development and aging.

PubMed

Wei, Shu; Hua, Hai-Rong; Chen, Qian-Quan; Zhang, Ying; Chen, Fei; Li, Shu-Qing; Li, Fan; Li, Jia-Li

2017-03-18

Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5-hydroxymethylcytosine (5hmC) ten-eleven translocation (TET) enzyme-mediated active DNA demethylation products were dynamically changed and involved in postnatal brain development and aging in tree shrews ( Tupaia belangeri chinensis ). The levels of 5hmC in multiple anatomic structures showed a gradual increase throughout postnatal development, whereas a significant decrease in 5hmC was found in several brain regions in aged tree shrews, including in the prefrontal cortex and hippocampus, but not the cerebellum. Active changes in Tet mRNA levels indicated that TET2 and TET3 predominantly contributed to the changes in 5hmC levels. Our findings provide new insight into the dynamic changes in 5hmC levels in tree shrew brains during postnatal development and aging processes.

Sticky snack for sengis: The Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea), as a pollinator of the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae)

NASA Astrophysics Data System (ADS)

Wester, Petra

2010-12-01

Following the recent discovery of rodent pollination in the Pagoda lily, Whiteheadia bifolia (Hyacinthaceae) in South Africa, now the Cape rock elephant-shrew, Elephantulus edwardii (Macroscelidea, Afrotheria) is reported as an additional pollinator. Elephant-shrews, live-trapped near W. bifolia plants, were released in two terraria, containing the plants. The animals licked nectar with their long and slender tongues while being dusted with pollen and touching the stigmas of the flowers with their long and flexible noses. The captured elephant-shrews had W. bifolia pollen in their faeces, likely as a result of grooming their fur as they visited the flowers without eating or destroying them. The animals mostly preferred nectar over other food. This is the first record of pollination and nectar consumption in the primarily insectivorous E. edwardii, contributing to the very sparse knowledge about the behaviour of this unique clade of African mammals, as well as pollination by small mammals.

Structure of corneal layers, collagen fibrils, and proteoglycans of tree shrew cornea

PubMed Central

Almubrad, Turki

2011-01-01

Purpose The stroma is the major part of the cornea, in which collagen fibrils and proteoglycans are distributed uniformly. We describe the ultrastructure of corneal layers, collagen fibrils (CF), and proteoglycans (PGs) in the tree shrew cornea. Methods Tree shrew corneas (5, 6, and 10 week old animals) and normal human corneas (24, 25, and 54 years old) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in a sodium acetate buffer. The tissue was processed for electron microscopy. The ‘iTEM Olympus Soft Imaging Solutions GmbH’ program was used to measure the corneal layers, collagen fibril diameters and proteoglycan areas. Results The tree shrew cornea consists of 5 layers: the epithelium, Bowman’s layer, stroma, Descemet’s membrane, and endothelium. The epithelium was composed of squamous cells, wing cells and basal cells. The Bowman’s layer was 5.5±1.0 µm thick and very similar to a normal human Bowman’s layer. The stroma was 258±7.00 µm thick and consisted of collagen fibril lamellae. The lamellae were interlaced with one another in the anterior stroma, but ran parallel to one another in the middle and posterior stroma. Collagen fibrils were decorated with proteoglycan filaments with an area size of 390 ±438 nm2. The collagen fibril had a minimum diameter of 39±4.25 nm. The interfibrillar spacing was 52.91±6.07 nm. Within the collagen fibrils, very small electron-dense particles were present. Conclusions The structure of the tree shrew cornea is very similar to that of the normal human cornea. As is the case with the human cornea, the tree shrew cornea had a Bowman's layer, lamellar interlacing in the anterior stroma and electron-dense particles within the collagen fibrils. The similarities of the tree shrew cornea with the human cornea suggest that it could be a good structural model to use when studying changes in collagen fibrils and proteoglycans in non-genetic corneal diseases, such as ectasia caused after LASIK (laser-assisted in situ keratomileusis). PMID:21921979

Effect of land cover, habitat fragmentation and ant colonies on the distribution and abundance of shrews in southern California

USGS Publications Warehouse

Laakkonen, Juha; Fisher, Robert N.; Case, Ted J.

2001-01-01

Because effects of habitat fragmentation and anthropogenic disturbance on native animals have been relatively little studied in arid areas and in insectivores, we investigated the roles of different land covers, habitat fragmentation and ant colonies on the distribution and abundance of shrews, Notiosorex crawfordi and Sorex ornatus, in southern California.Notiosorex crawfordi was the numerically dominant species (trap-success rate 0·52) occurring in 21 of the 22 study sites in 85% of the 286 pitfall arrays used in this study.Sorex ornatus was captured in 14 of the sites, in 52% of the arrays with a total trap-success rate of 0·2. Neither of the species was found in one of the sites.The population dynamics of the two shrew species were relatively synchronous during the 4–5-year study; the peak densities usually occurred during the spring. Precipitation had a significant positive effect, and maximum temperature a significant negative effect on the trap-success rate of S. ornatus.Occurrence and abundance of shrews varied significantly between sites and years but the size of the landscape or the study site had no effect on the abundance of shrews. The amount of urban edge had no significant effect on the captures of shrews but increased edge allows invasion of the Argentine ants, which had a highly significant negative impact on the abundance of N. crawfordi.At the trap array level, the percentage of coastal sage scrub flora had a significant positive, and the percentage of other flora had a significant negative effect on the abundance of N. crawfordi. The mean canopy height and the abundance of N. crawfordi had a significant positive effect on the occurrence of S. ornatus.Our study suggests that the loss of native coastal sage scrub flora and increasing presence of Argentine ant colonies may significantly effect the distribution and abundance of N. crawfordi. The very low overall population densities of both shrew species in most study sites make both species susceptible to extinction in isolated habitat fragments due to environmental stochasticity, and anthropogenic disturbance.

Nuclear Geoplosics Sourcebook. Volume IV. Part I. Empirical Analysis of Ground Motion from Above and Underground Explosions

DTIC Science & Technology

1979-03-01

for some detonations, for example, PLATYPUS , SHREW, and ERMINE, this secondary acceleration pulse is not evident in the data. *Maximum vertical...RADIAL C..) _j n ’U~n" -- m RINGTAIL \\ ,• • n MINK P "W o PLATYPUS \\ \\ •" p SHREW \\- .Cq HOGNOSERAD s ERMINEb; w CHINCHILLA \\ 0.10 1.0 10 102 DEPTH OF...h2xHOGNOSE RADIAL 0 _ 1 . - \\ \\\\ \\ m RINGTAIL n MINK a PLATYPUS p SHREW q HOGNOSE s ERMINE w CHINCHILLA 0.101I I I I I 1 LJI t. 10 30 DEPTH OF BURST, 102 ft

CircRNAs in the tree shrew (Tupaia belangeri) brain during postnatal development and aging.

PubMed

Lu, CaiXia; Sun, XiaoMei; Li, Na; Wang, WenGuang; Kuang, DeXuan; Tong, PinFen; Han, YuanYuan; Dai, JieJie

2018-04-30

Circular RNAs (circRNAs) are a novel type of non-coding RNA expressed across different species and tissues. At present, little is known about the expression and function of circRNAs in the tree shrew brain. In this study, we used RNA-seq to identify 35,007 circRNAs in hippocampus and cerebellum samples from infant (aged 47-52 days), young (aged 15-18 months), and old (aged 78-86 months) tree shrews. We observed no significant changes in the total circRNA expression profiles in different brain regions over time. However, circRNA tended to be downregulated in the cerebellum over time. Real-time RT-PCR analysis verified the presence of circRNAs. KEGG analysis indicated the occurrence of ubiquitin-mediated proteolysis, the MAPK signaling pathway, phosphatidylinositol signaling system, long-term depression, the rap1 signaling pathway, and long-term potentiation in both brain regions. We also observed that 29,087 (83.1%) tree shrew circRNAs shared homology with human circRNAs. The competing endogenous RNA networks suggested novel_circRNA_007362 potential functions as a 24-miRNAs sponge to regulate UBE4B expression. Thus, we obtained comprehensive circRNA expression profiles in the tree shrew brain during postnatal development and aging, which might help to elucidate the functions of circRNAs during brain aging and in age-related diseases.

Micro-CT application for infiltration technology in paedodontics and orthodontics

NASA Astrophysics Data System (ADS)

Ogodescu, Alexandru; Manescu, Adrian; Ogodescu, Ana Emilia; Giuliani, Alessandra; Todea, Carmen

2014-01-01

White spot lesions are an early evidence of the demineralization of the enamel surface and are the first step of future caries that will develop on those spots. Recently, a new and innovative biotechnology was developed - Icon, a caries infiltrant to be introduced in early tooth lesions, able to achieve a very good preservation of dental structures. In order to assess the infiltrant penetration level inside the white spot lesions, a non-destructive 3D visualization method is needed. Phase-contrast micro computed tomography using synchrotron radiation proved to be a powerful technique, allowing a 3D morphological investigation of all the components of interest: tooth structure, white spot lesions extension, infiltrant penetration inside the lesions, without the need of slicing the specimens. From our clinical experience and the conducted research we can conclude that this technology is effective and useful in many clinical situations encountered in pediatric dentistry.

Improved starch digestion of sucrase deficient shrews treated with oral glucoamylase enzyme supplements

USDA-ARS?s Scientific Manuscript database

Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with Congenita...

Predatory behaviors of Blarina brevicauda toward a fossorial eastern spadefoot toad (Scaphiopus holbrookii)

Treesearch

Thomas J. Maier

2005-01-01

Northern short-tailed shrews (Blarina brevicauda) have been reported to prey upon relatively large salamanders and anurans. Nevertheless, detailed observations of such behavior are rare, though important in providing insights into shrew foraging strategies, prey capture and handling, and possibly the coevolution of predator-antipredator mechanisms....

Aggregations of masked shrews (Sorex cinereus): density related mating behavior?

Treesearch

Thomas J. Maier; Katherine L. Doyle

2006-01-01

Large aggregations of shrews have been reported and various explanations offered for this seemingly rare behavior; however, there has been little evidence to support any particular interpretation. We observed two small aggregations of highly active vocalizing Sorex cinereus while performing wildlife surveys in forested habitats in central...

Structural Analysis Of CD59 Of Chinese Tree Shrew: A New Reference Molecule For Human Immune System Specific CD59 Drug Discovery.

PubMed

Panda, Subhamay; Kumari, Leena; Panda, Santamay

2017-11-17

Chinese tree shrews (Tupaia belangeri chinensis) bear several characteristics that are considered to be very crucial for utilizing in animal experimental models in biomedical research. Subsequent to the identification of key aspects and signaling pathways in nervous and immune systems, it is revealed that tree shrews acquires shared common as well as unique characteristics, and hence offers a genetic basis for employing this animal as a prospective model for biomedical research. CD59 glycoprotein, commonly referred to as MAC-inhibitory protein (MAC-IP), membrane inhibitor of reactive lysis (MIRL), or protectin, is encoded by the CD59 gene in human beings. It is the member of the LY6/uPAR/alpha-neurotoxin protein family. With this initial point the objective of this study was to determine a comparative composite based structure of CD59 of Chinese tree shrew. The additional objective of this study was to examine the distribution of negatively and positively charged amino acid over molecular modeled structure, distribution of secondary structural elements, hydrophobicity molecular surface analysis and electrostatic potential analysis with the assistance of several bioinformatical analytical tools. CD59 Amino acid sequence of Chinese tree shrew collected from the online database system of National Centre for Biotechnology Information. SignalP 4.0 online server was employed for detection of signal peptide instance within the protein sequence of CD59. Molecular model structure of CD59 protein was generated by the Iterative Threading ASSEmbly Refinement (I-TASSER) suite. The confirmation for three-dimensional structural model was evaluated by structure validation tools. Location of negatively and positively charged amino acid over molecular modeled structure, distribution of secondary structural elements, and hydrophobicity molecular surface analysis was performed with the help of Chimera tool. Electrostatic potential analysis was carried out with the adaptive Poisson-Boltzmann solver package. Subsequently validated model was used for the functionally critical amino acids and active site prediction. The functionally critical amino acids and ligand- binding site (LBS) of the proteins (modeled) was determined using the COACH program. Analysis of Ramachandran plot for Chinese tree shrew depicted that overall, 100% of the residues in homology model were observed in allowed and favored regions, sequentially leading to the validation of the standard of generated protein structural model. In case of CD59 of Chinese tree shrew, the total score of G-factor was found to be -0.66 that was generally larger than the acceptable value. This approach suggests the significance and acceptability of the modeled structure of CD59 of Chinese tree shrew. The molecular model data in cooperation to other relevant post model analysis data put forward molecular insight to protecting activity of CD59 protein molecule of Chinese tree shrew. In the present study, we have proposed the first molecular model structure of uncharted CD59 of Chinese tree shrew by significantly utilizing the comparative composite modeling approach. Therefore, the development of a structural model of the CD59 protein was carried out and analyzed further for deducing molecular enrichment technique. The collaborative effort of molecular model and other relevant data of post model analysis carry forward molecular understanding to protecting activity of CD59 functions towards better insight of features of this natural lead compound. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The Nd-YAG laser is useful in prevention of dental caries during orthodontic treatment.

PubMed

Harazaki, M; Hayakawa, K; Fukui, T; Isshiki, Y; Powell, L G

2001-05-01

Plaque control during the course of orthodontic treatment is not an easy task, and dental caries are not an unlikely complication. We examined the possibility of controlling dental caries with Nd-YAG laser irradiation in orthodontic patients. As a preliminary experiment, we used the Nd-YAG laser to irradiate an extracted tooth and then left it to soak in lactic acid. The decay of the tooth was evaluated with a scanning electron microscope (SEM); tooth decay was inhibited by the action of the laser. Twenty patients undergoing orthodontic treatment for early decalcification of the teeth (white spot lesions) were selected, and photographs were taken of their oral cavities. White spot lesions on the four incisors and two canines of the maxilla were traced on tracing paper, and their areas were calculated by computer. Ten of the patients received laser treatment and acidulated phosphate fluoride solution (APF); the other ten acted as the control group. Between 11 and 12 months later, we photographed the oral cavity as we had previously; the white spot lesions were again traced and their areas calculated. The changes in the areas of the white spots of the laser-irradiated and control groups showed the following increases: laser-irradiated group, 1.41 times; controls, 2.87 times. The difference was statistically significant. These results demonstrate that Nd-YAG laser irradiation with application of APF acts as an effective method of caries control during orthodontic treatment.

The In vitro Evaluation of the effect of xyliwhite, probiotic, and the conventional toothpastes on the enamel roughness and microhardness.

PubMed

Maden, E Arat; Altun, C; Polat, G Guven; Basak, F

2018-03-01

The aim of this study was to evaluate the effect of fluoride, Xylitol, Probiotic, and Whitening toothpastes on the permanent teeth enamel roughness and microhardness. One hundred and twenty teeth were randomly divided into 2 groups, each group having 60 samples. G1: The group in which enamel roughness was examined (n = 60). G2: The group in which enamel microhardness was examined (n = 60). Then, these groups were randomly divided into 4 groups among themselves (n = 15). Each group was brushed using four different toothpastes for 1 week with a battery-powered toothbrush in the morning and evening for 2 min. Vicker's hardness tester was used to measure the changes in microhardness, and the profilometer was used to measure the changes in surface roughness. No statistically significant differences were found on surface roughness and microhardness values measured after tooth brushing process in group brushed with Colgate MaxFresh toothpaste (P > 0.01). Statistically significant decrease was observed on Vicker's hardness values measured after tooth brushing process in groups brushed with Ipana White Power Carbonate toothpaste, Xyliwhite Toothpaste Gel, and Periobiotic Probiotic Toothpaste (P < 0.01). Statistically significant increase was observed on surface roughness values in groups brushed with Ipana White Power Carbonate toothpaste, Xyliwhite Toothpaste Gel, Periobiotic Probiotic Toothpaste (P < 0.01). As a result, Colgate MaxFresh abrasive-free toothpaste with fluoride has no effect on permanent tooth enamel surface roughness and microhardness. Xyliwhite, Periobiotic, and Ipana White Power Carbonate-containing abrasive toothpastes led to changes negatively on permanent tooth enamel surface roughness and microhardness.

Imaging and detection of early stage dental caries with an all-optical photoacoustic microscope

NASA Astrophysics Data System (ADS)

Hughes, D. A.; Sampathkumar, A.; Longbottom, C.; Kirk, K. J.

2015-01-01

Tooth decay, at its earliest stages, manifests itself as small, white, subsurface lesions in the enamel. Current methods for detection in the dental clinic are visual and tactile investigations, and bite-wing X-ray radiographs. These techniques suffer from poor sensitivity and specificity at the earliest (and reversible) stages of the disease due to the small size (<100μm) of the lesion. A fine-resolution (600 nm) ultra-broadband (200 MHz) all-optical photoacoustic microscopy system was is used to image the early signs of tooth decay. Ex-vivo tooth samples exhibiting white spot lesions were scanned and were found to generate a larger (one order of magnitude) photoacoustic (PA) signal in the lesion regions compared to healthy enamel. The high contrast in the PA images potentially allows lesions to be imaged and measured at a much earlier stage than current clinical techniques allow. PA images were cross referenced with histology photographs to validate our experimental results. Our PA system provides a noncontact method for early detection of white-spot lesions with a high detection bandwidth that offers advantages over previously demonstrated ultrasound methods. The technique provides the sensing depth of an ultrasound system, but with the spatial resolution of an optical system.

Present and future technologies of tooth whitening.

PubMed

Viscio, D; Gaffar, A; Fakhry-Smith, S; Xu, T

2000-01-01

Dental stains can be broadly classified as intrinsic or extrinsic. Intrinsic stains are a result of defects in tooth development, fluorosis, or acquired through the use of tetracycline. Extrinsic stains are localized mainly in the pellicle and are generated by the reaction between sugars and amino acids or acquired from the retention of exogenous chromophores in the pellicle. Three clinical methods are currently used for measuring stain removal and tooth whitening in the development of new whitening technologies: Lobene Stain Index, Shade Guide Color Change, and Minolta ChromaMeter. Professional tooth whitening products rely on proven technologies--35% hydrogen peroxide for in-office power bleaching or 10% to 15% carbamide peroxide for at-home bleaching--to reduce intrinsic stain and change the inherent tooth color. Over-the-counter tooth whitening products use a combination of surfactants, abrasives, anticalculus agents, and low levels of hydrogen peroxide to reduce extrinsic stain and help maintain tooth whiteness after professional treatment. Future technologies for whitening teeth could involve the use of activating agents to enhance the performance of hydrogen peroxide and natural enzymes.

A new species of small-eared shrew (Mammalia, Eulipotyphla, Cryptotis) from the Lacandona rain forest, Mexico

USGS Publications Warehouse

Guevara, Lázaro; Sánchez-Cordero, Víctor; León-Paniagua, Livia; Woodman, Neal

2014-01-01

The diversity and distribution of mammals in the American tropics remain incompletely known. We describe a new species of small-eared shrew (Soricidae, Cryptotis) from the Lacandona rain forest, Chiapas, southern Mexico. The new species is distinguished from other species of Cryptotis on the basis of a unique combination of pelage coloration, size, dental, cranial, postcranial, and external characters, and genetic distances. It appears most closely related to species in the Cryptotis nigrescens species group, which occurs from southern Mexico to montane regions of Colombia. This discovery is particularly remarkable because the new species is from a low-elevation habitat (approximately 90 m), whereas most shrews in the region are restricted to higher elevations, typically > 1,000 m. The only known locality for the new shrew is in one of the last areas in southern Mexico where relatively undisturbed tropical vegetation is still found. The type locality is protected by the Mexican government as part of the Yaxchilán Archaeological Site on the border between Mexico and Guatemala.

Identification and distribution of the Olympic Shrew (Eulipotyphla: Soricidae), Sorex rohweri Rausch et al., 2007 in Oregon and Washington, based on USNM specimens

USGS Publications Warehouse

Woodman, Neal; Fisher, Robert D.

2016-01-01

Review of specimens of long-tailed shrews (Mammalia, Soricidae, Sorex) from the northwestern United States in the National Museum of Natural History (USNM), Washington, DC, has revealed the presence of the Olympic Shrew, Sorex rohweri Rausch et al., 2007, in the Coastal Range west of the Willamette Valley in Oregon. This determination nearly doubles the documented distribution for this species and increases the species diversity of soricids in Oregon to eleven. Sorex rohweri is relatively uncommon, but it occurs in a variety of forest successional stages and even clear cuts, as long as there is nearby forest and trees are allowed to regenerate. All USNM specimens from Washington formerly identified as S. cinereus streatori Merriam, 1895 are instead referable to the Olympic Shrew. The distribution of S. c. streatori is thereby restricted to the Pacific coasts of British Columbia north of the lower Frasier River and south central Alaska. Our study highlights the importance of taking and preserving high-quality voucher specimens in a collection where they are readily available for re-study.

Identification and characterization of toll-like receptors (TLRs) in the Chinese tree shrew (Tupaia belangeri chinensis).

PubMed

Yu, Dandan; Wu, Yong; Xu, Ling; Fan, Yu; Peng, Li; Xu, Min; Yao, Yong-Gang

2016-07-01

In mammals, the toll-like receptors (TLRs) play a major role in initiating innate immune responses against pathogens. Comparison of the TLRs in different mammals may help in understanding the TLR-mediated responses and developing of animal models and efficient therapeutic measures for infectious diseases. The Chinese tree shrew (Tupaia belangeri chinensis), a small mammal with a close relationship to primates, is a viable experimental animal for studying viral and bacterial infections. In this study, we characterized the TLRs genes (tTLRs) in the Chinese tree shrew and identified 13 putative TLRs, which are orthologs of mammalian TLR1-TLR9 and TLR11-TLR13, and TLR10 was a pseudogene in tree shrew. Positive selection analyses using the Maximum likelihood (ML) method showed that tTLR8 and tTLR9 were under positive selection, which might be associated with the adaptation to the pathogen challenge. The mRNA expression levels of tTLRs presented an overall low and tissue-specific pattern, and were significantly upregulated upon Hepatitis C virus (HCV) infection. tTLR4 and tTLR9 underwent alternative splicing, which leads to different transcripts. Phylogenetic analysis and TLR structure prediction indicated that tTLRs were evolutionarily conserved, which might reflect an ancient mechanism and structure in the innate immune response system. Taken together, TLRs had both conserved and unique features in the Chinese tree shrew. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multilocus phylogeography and systematic revision of North American water shrews (genus: Sorex)

USGS Publications Warehouse

Hope, Andrew G.; Panter, Nicholas; Cook, Joseph A.; Talbot, Sandra L.; Nagorsen, David W.

2014-01-01

North American water shrews, which have traditionally included Sorex alaskanus, S. bendirii, and S. palustris, are widely distributed through Nearctic boreal forests and adapted for life in semiaquatic environments. Molecular mitochondrial signatures for these species have recorded an evolutionary history with variable levels of regional divergence, suggesting a strong role of Quaternary environmental change in speciation processes. We expanded molecular analyses, including more-comprehensive rangewide sampling of specimens representing North American water shrew taxa, except S. alaskanus, and sequencing of 4 independent loci from the nuclear and mitochondrial genomes. We investigated relative divergence of insular populations along the North Pacific Coast, and newly recognized diversity from southwestern montane locations, potentially representing refugial isolates. Congruent independent genealogies, lack of definitive evidence for contemporary gene flow, and high support from coalescent species trees indicated differentiation of 4 major geographic lineages over multiple glacial cycles of the late Quaternary, similar to a growing number of boreal taxa. Limited divergence of insular populations suggested colonization following the last glacial. Characterization of southwestern montane diversity will require further sampling but divergence over multiple loci is indicative of a relictual sky-island fauna. We have reviewed and revised North American water shrew taxonomy including the recognition of 3 species within what was previously known as S. palustris. The possibility of gene flow between most distantly related North American water shrew lineages coupled with unresolved early diversification of this group and other sibling species reflects a complex but potentially productive system for investigating speciation processes.

Effectiveness of and Dental Sensitivity to At-home Bleaching With 4% and 10% Hydrogen Peroxide: A Randomized, Triple-blind Clinical Trial.

PubMed

Chemin, K; Rezende, M; Loguercio, A D; Reis, A; Kossatz, S

To evaluate the risk for and intensity of tooth sensitivity and color change of at-home dental bleaching with 4% and 10% hydrogen peroxide (HP). For this study, 78 patients were selected according to the inclusion and exclusion criteria and randomized into two groups: HP 4 (White Class 4%, FGM) and HP 10 (White Class 10%, FGM). In both groups, the at-home bleaching was performed for a period of 30 minutes twice a day for two weeks. The color was assessed by Vita Classical, Vita Bleachedguide 3D-MASTER and spectrophotometer Vita Easyshade (Vita Zahnfabrik) at baseline, during bleaching (first and second weeks) and after bleaching (one month). Patients recorded their tooth sensitivity using a numeric rating scale (0-4) and visual analog scale (0-10). Data from color change (DeltaE data) was submitted to two-way analysis of variance. The color change data in Delta SGU from the two shade guide units were compared with the Mann Whitney test. The risk of tooth sensitivity was evaluated by χ 2 test and the intensity of tooth sensitivity from both scales was evaluated by a Mann-Whitney test (α=0.05). The absolute risk and intensity of tooth sensitivity was higher in the group that used HP 10 than the one that used HP 4. Data from change in the number of shade guide units and color variation after one month of bleaching for both groups showed significant whitening, with no difference between groups. At-home bleaching is effective with 4% and 10% HP concentrations, but 10% HP increased the absolute risk and intensity of tooth sensitivity during at-home bleaching.

[COMPARATIVE CHARACTERISTICS OF uNOS-POSITIVE STRUCTURES IN THE CNS OF SOME SPECIES OF CRUSTACEANS].

PubMed

Chertok, V M; Kotsyuba, E P

2015-01-01

We conducted a comparative study of NO-ergic system in the CNS of 10 species of crustaceans subclass Malacostraca, belonging to orders Stomatopoda and Decapoda, with a common habitat in Ussuri Bay (Sea of Japan). Both similar characteristics and differences in content and distribution of universal NO-synthase (uNOS) were revealed in homologous parts of the brain and ventral nerve cord of the investigated species of crustaceans. We discuss the involvement of nitric oxide in the regulation of physiological functions of decapod crustaceans and its role in the processes of adaptation to the environmental conditions.

Overview of the Cestode fauna of European shrews of the genus Sorex with an exploration of historical processes in post-glacial Europe

USDA-ARS?s Scientific Manuscript database

The cestode fauna in shrews of the genus Sorex from the European region consists of seventeen species. Twelve cestode species have broad Palearctic distributions, three belong to the Western-Asian–European faunistic complex, and only two are endemic to the European zone. Postglacial expansion into ...

"The Taming of the Shrew." A Play Packet To Accompany "Elementary, My Dear Shakespeare."

ERIC Educational Resources Information Center

Engen, Barbara; Campbell, Joy

Intended for use by elementary school teachers as a supplement to the book, "Elementary, My Dear Shakespeare," or for use by itself to produce one Shakespeare play, this play packet contains ready-to-reproduce materials for the production of "The Taming of the Shrew." Materials include: staging suggestions for scenery, props,…

A new species of small-eared shrew from Colombia and Venezuela (Mammalia: Soricomorpha: Soricidae: Genus Cryptotis)

USGS Publications Warehouse

Woodman, N.

2002-01-01

Populations of small-eared shrews inhabiting the northern Cordillera Oriental of Colombia and adjoining Venezuelan highlands in the vicinity of Paramo de Tama have been referred alternatively to Cryptotis thomssi or Cryptotis meridensis. Morphological and morphometrical study of this population indicates that it belongs to neither taxon, but represents a distinct, previously unrecognized species. I describe this new species as Cryptotis tamensis and redescribe C. meridensis. Recognition of the population at Paramo de Tama as a separate taxon calls into question the identities of populations of shrews currently represented only by single specimens from Cerro Pintado in the Sierra de Perija, Colombia, and near El Junquito in the coastal highlands of Venezuela.

Effects of Experimental Manipulations of Course Woody Debris on Sorcids and Other Fauna

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCay, T.S.; Komoroski, M.J.; Ford, W.M.

2001-06-10

The authors studied the relationship between the level of course woody debris in experimental plots of mature loblolly pine and the richness and abundance of shrews, reptiles and amphibians. Comparisons were made between plots in which all down and standing debris were removed and plots that were not treated. Removal of woody debris resulted in a week treatment effect. The capture of southeastern shrews declined through the period perhaps due to drought. The least common shrew demonstrated the strongest effects from removal.In sampling 37 species of amphibians were observed. The Carolina anole and the red salamander were captured more frequentlymore » on removal plots. No difference were found between removal and controls with regard to reptiles.« less

Spatially Explicit Analysis of Metal Transfer to Biota: Influence of Soil Contamination and Landscape

PubMed Central

Fritsch, Clémentine; Cœurdassier, Michaël; Giraudoux, Patrick; Raoul, Francis; Douay, Francis; Rieffel, Dominique; de Vaufleury, Annette; Scheifler, Renaud

2011-01-01

Concepts and developments for a new field in ecotoxicology, referred to as “landscape ecotoxicology,” were proposed in the 1990s; however, to date, few studies have been developed in this emergent field. In fact, there is a strong interest in developing this area, both for renewing the concepts and tools used in ecotoxicology as well as for responding to practical issues, such as risk assessment. The aim of this study was to investigate the spatial heterogeneity of metal bioaccumulation in animals in order to identify the role of spatially explicit factors, such as landscape as well as total and extractable metal concentrations in soils. Over a smelter-impacted area, we studied the accumulation of trace metals (TMs: Cd, Pb and Zn) in invertebrates (the grove snail Cepaea sp and the glass snail Oxychilus draparnaudi) and vertebrates (the bank vole Myodes glareolus and the greater white-toothed shrew Crocidura russula). Total and CaCl2-extractable concentrations of TMs were measured in soils from woody patches where the animals were captured. TM concentrations in animals exhibited a high spatial heterogeneity. They increased with soil pollution and were better explained by total rather than CaCl2-extractable TM concentrations, except in Cepaea sp. TM levels in animals and their variations along the pollution gradient were modulated by the landscape, and this influence was species and metal specific. Median soil metal concentrations (predicted by universal kriging) were calculated in buffers of increasing size and were related to bioaccumulation. The spatial scale at which TM concentrations in animals and soils showed the strongest correlations varied between metals, species and landscapes. The potential underlying mechanisms of landscape influence (community functioning, behaviour, etc.) are discussed. Present results highlight the need for the further development of landscape ecotoxicology and multi-scale approaches, which would enhance our understanding of pollutant transfer and effects in ecosystems. PMID:21655187

Elevational Distribution and Ecology of Small Mammals on Africa’s Highest Mountain

PubMed Central

Stanley, William T.; Rogers, Mary Anne; Kihaule, Philip M.; Munissi, Maiko J.

2014-01-01

Mt Kilimanjaro is Africa’s highest mountain, and an icon for a country famous for its mammalian fauna. The distribution and abundance of small mammals on the mountain are poorly known. Here we document the distribution of shrews and rodents along an elevational gradient on the southeastern versant of Kilimanjaro. Five sites were sampled with elevational center points of 2000, 2500, 3000, 3500 and 4000 m, using a systematic methodology of standard traps and pitfall lines, to inventory the shrews and rodents of the slope. Sixteen species of mammal were recorded, including 6 shrew and 10 rodent species, and the greatest diversity of both was found at 3000 m, the elevational midpoint of the transect. No species previously unrecorded on Kilimanjaro were observed. Two genera of rodents that occur in nearby mountains (Hylomyscus and Beamys) were not recorded. Myosorex zinki, the only mammal endemic to Mt. Kilimanjaro, which previously was known by only a few specimens collected in the ericaceous or moorland habitat, was found in all but one (the lowest) of the sites sampled, and was one of the most widespread species of small mammal along the gradient. Two shrews (Crocidura allex and Sylvisorex granti) and one rodent (Dendromus insignis) were found throughout the entire transect, with Dendromus being observed at our highest trap point (4240 m). As in similar faunal surveys on other mountains of Tanzania, rainfall influenced the sample success of shrews, but not rodents. Trap success for rodents at 3500 m was notably low. This study contributes further justification for the conservation of the forest habitat of Mt. Kilimanjaro. PMID:25372387

Demographic responses of shrews to removal of coarse woody debris in a managed pine forest

Treesearch

Timothy S. McCay; Mark J. Komoroski

2004-01-01

We trapped shrews at six 9.3 ha plots from which logs ≥10 cm diameter (coarse woody debris; CWD) had been manually removed and six control plots in managed loblolly pine (Pinus taeda) forests of the southeastern coastal plain, USA. Trapping was conducted seasonally between antumn 1997 and summer 2001. Capture rates of Cryptotis...

Assembly rules for functional groups of North American shrews: effects of geographic range and habitat partitioning

Treesearch

Timothy S. McCay; Matthew J. Lovallo; W. Mark Ford; Michael A. Menzel; Michael A. Menzel

2004-01-01

We examined the representation of shrew species within assemblages at 197 sites in the southern Appalachian Mountains, USA. Assemblages were classified according to representation of functional groups, including fossorial, small epigeal, and large epigeal. Average (9?SD) species richness was 2.99?1.0 and assemblages averaged 0.8 species in the fossorial and large...

A new species of small-eared shrew in the Cryptotis thomasi species group from Costa Rica (Mammalia: Eulipotyphla: Soricidae)

USGS Publications Warehouse

Woodman, Neal; Timm, Robert M.

2017-01-01

We describe a new species of small-eared shrew, genus Cryptotis Pomel, 1848 (Eulipotyphla: Soricidae), from near the community of Monteverde in the Tilarán highlands of northwestern Costa Rica. The new species is immediately distinguished from all other Costa Rican shrews its large size and long tail. Morphologically, it belongs to the Cryptotis thomasi group of small-eared shrews, a clade that is more typically distributed in the Andes Cordillera and other highland regions of northern South America. The new Costa Rican species and the Panamanian endemic Cryptotis endersi Setzer, 1950 are the only two members of this species group known to occur in Central America. Like most other members of the C. thomasi group for which the postcranial skeleton has been studied, the new species tends be more ambulatory (rather than semi-fossorial) when compared with other members of the genus. Our survey efforts over several decades failed to locate a population of the new species, and we discuss its conservation status in light of its limited potential distribution in the Tilarán highlands and the significant climatic change that has been documented in the Monteverde region during the past four decades.

Tree shrew lavatories: a novel nitrogen sequestration strategy in a tropical pitcher plant.

PubMed

Clarke, Charles M; Bauer, Ulrike; Lee, Ch'ien C; Tuen, Andrew A; Rembold, Katja; Moran, Jonathan A

2009-10-23

Nepenthes pitcher plants are typically carnivorous, producing pitchers with varying combinations of epicuticular wax crystals, viscoelastic fluids and slippery peristomes to trap arthropod prey, especially ants. However, ant densities are low in tropical montane habitats, thereby limiting the potential benefits of the carnivorous syndrome. Nepenthes lowii, a montane species from Borneo, produces two types of pitchers that differ greatly in form and function. Pitchers produced by immature plants conform to the 'typical' Nepenthes pattern, catching arthropod prey. However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid. We tested the hypothesis that tree shrew faeces represent a significant nitrogen (N) source for N. lowii, finding that it accounts for between 57 and 100 per cent of foliar N in mature N. lowii plants. Thus, N. lowii employs a diversified N sequestration strategy, gaining access to a N source that is not available to sympatric congeners. The interaction between N. lowii and tree shrews appears to be a mutualism based on the exchange of food sources that are scarce in their montane habitat.

Tree shrew lavatories: a novel nitrogen sequestration strategy in a tropical pitcher plant

PubMed Central

Clarke, Charles M.; Bauer, Ulrike; Lee, Ch'ien C.; Tuen, Andrew A.; Rembold, Katja; Moran, Jonathan A.

2009-01-01

Nepenthes pitcher plants are typically carnivorous, producing pitchers with varying combinations of epicuticular wax crystals, viscoelastic fluids and slippery peristomes to trap arthropod prey, especially ants. However, ant densities are low in tropical montane habitats, thereby limiting the potential benefits of the carnivorous syndrome. Nepenthes lowii, a montane species from Borneo, produces two types of pitchers that differ greatly in form and function. Pitchers produced by immature plants conform to the ‘typical’ Nepenthes pattern, catching arthropod prey. However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid. We tested the hypothesis that tree shrew faeces represent a significant nitrogen (N) source for N. lowii, finding that it accounts for between 57 and 100 per cent of foliar N in mature N. lowii plants. Thus, N. lowii employs a diversified N sequestration strategy, gaining access to a N source that is not available to sympatric congeners. The interaction between N. lowii and tree shrews appears to be a mutualism based on the exchange of food sources that are scarce in their montane habitat. PMID:19515656

Horizontal transfers of Mariner transposons between mammals and insects.

PubMed

Oliveira, Sarah G; Bao, Weidong; Martins, Cesar; Jurka, Jerzy

2012-09-26

Active transposable elements (TEs) can be passed between genomes of different species by horizontal transfer (HT). This may help them to avoid vertical extinction due to elimination by natural selection or silencing. HT is relatively frequent within eukaryotic taxa, but rare between distant species. Closely related Mariner-type DNA transposon families, collectively named as Mariner-1_Tbel families, are present in the genomes of two ants and two mammalian genomes. Consensus sequences of the four families show pairwise identities greater than 95%. In addition, mammalian Mariner1_BT family shows a close evolutionary relationship with some insect Mariner families. Mammalian Mariner1_BT type sequences are present only in species from three groups including ruminants, tooth whales (Odontoceti), and New World leaf-nosed bats (Phyllostomidae). Horizontal transfer accounts for the presence of Mariner_Tbel and Mariner1_BT families in mammals. Mariner_Tbel family was introduced into hedgehog and tree shrew genomes approximately 100 to 69 million years ago (MYA). Most likely, these TE families were transferred from insects to mammals, but details of the transfer remain unknown.

Crossover clinical investigation of a whitening chewing gum for inhibiting dental stain formation in conjunction with tooth brushing.

PubMed

Milleman, Jeffery L; Milleman, Kimberly R; Kleber, Carl J; Proskin, Howard M; Dodds, Michael; Kelley, Michael; Ramirez, Lilian

2014-01-01

The purpose of this clinical investigation was to evaluate the effectiveness of a marketed whitening chewing gum compared to a no-gum control in preventing the formation of extrinsic stains on the teeth of stain-forming subjects when chewed over a 12-week period of regular unsupervised use in conjunction with daily tooth brushing. This was a single-center, examiner-blind, randomized, 12-week crossover clinical trial. Stain-forming (after smoking or drinking coffee or tea) adults, starting with a stain-free baseline, either chewed the test gum (Orbit White) unsupervised four times per day, 15 minutes/chew, or used no gum along with daily brushing with a commercially available toothbrush and dentifrice for 12 weeks. At the crossover, all procedures were repeated with subjects assigned the opposite treatment. Extrinsic stain was measured at six and 12 weeks by both the Lobene Stain Index (LSI) and the Modified Lobene Stain Index (MLSI) using separate experienced examiners. After 12 weeks, LSI stain scores showed a significant 25% reduction (p = 0.0008) in new stain formation for subjects using the test chewing gum along with tooth brushing versus tooth brushing alone (no-gum control). The corresponding MLSI stain scores demonstrated a 36% reduction (p < 0.0001) in the formation of extrinsic stain on the teeth. The overall findings of this clinical study demonstrated that regular use of Orbit White chewing gum, soon after smoking or drinking coffee or tea, will supplement daily tooth brushing in preventing unsightly stains from forming on the anterior teeth compared to brushing alone.

Dental maturation, eruption, and gingival emergence in the upper jaw of newborn primates.

PubMed

Smith, Timothy D; Muchlinski, Magdalena N; Jankord, Kathryn D; Progar, Abbigal J; Bonar, Christopher J; Evans, Sian; Williams, Lawrence; Vinyard, Christopher J; Deleon, Valerie B

2015-12-01

In this report we provide data on dental eruption and tooth germ maturation at birth in a large sample constituting the broadest array of non-human primates studied to date. Over 100 perinatal primates, obtained from natural captive deaths, were screened for characteristics indicating premature birth, and were subsequently studied using a combination of histology and micro-CT. Results reveal one probable unifying characteristic of living primates: relatively advanced maturation of deciduous teeth and M1 at birth. Beyond this, there is great diversity in the status of tooth eruption and maturation (dental stage) in the newborn primate. Contrasting strategies in producing a masticatory battery are already apparent at birth in strepsirrhines and anthropoids. Results show that dental maturation and eruption schedules are potentially independently co-opted as different strategies for attaining feeding independence. The most common strategy in strepsirrhines is accelerating eruption and the maturation of the permanent dentition, including replacement teeth. Anthropoids, with only few exceptions, accelerate mineralization of the deciduous teeth, while delaying development of all permanent teeth except M1. These results also show that no living primate resembles the altricial tree shrew (Tupaia) in dental development. Our preliminary observations suggest that ecological explanations, such as diet, provide an explanation for certain morphological variations at birth. These results confirm previous work on perinatal indriids indicating that these and other primates telegraph their feeding adaptations well before masticatory anatomy is functional. Quantitative analyses are required to decipher specific dietary and other influences on dental size and maturation in the newborn primate. © 2015 Wiley Periodicals, Inc.

Dental maturation, eruption, and gingival emergence in the upper jaw of newborn primates

PubMed Central

Smith, Timothy D.; Muchlinksi, Magdalena N.; Jankord, Kathryn D.; Progar, Abbigal J.; Bonar, Christopher J.; Evans, Sian; Williams, Lawrence; Vinyard, Christopher J.; DeLeon, Valerie B.

2015-01-01

In this report we provide data on dental eruption and tooth germ maturation at birth in a large sample constituting the broadest array of non-human primates studied to date. Over 100 perinatal primates, obtained from natural captive deaths, were screened for characteristics indicating premature birth, and were subsequently studied using a combination of histology and micro-CT. Results reveal one probable unifying characteristic of living primates: relatively advanced maturation of deciduous teeth and M1 at birth. Beyond this, there is great diversity in the status of tooth eruption and maturation (dental stage) in the newborn primate. Contrasting strategies in producing a masticatory battery are already apparent at birth in strepsirrhines and anthropoids. Results show that dental maturation and eruption schedules are potentially independently co-opted as different strategies for attaining feeding independence. The most common strategy in strepsirrhines is accelerating eruption and the maturation of the permanent dentition, including replacement teeth. Anthropoids, with only few exceptions, accelerate mineralization of the deciduous teeth, while delaying development of all permanent teeth except M1. These results also show that no living primate resembles the altricial tree shrew (Tupaia) in dental development. Our preliminary observations suggest that ecological explanations, such as diet, provide an explanation for certain morphological variations at birth. These results confirm previous work on perinatal indriids indicating that these and other primates telegraph their feeding adaptations well before masticatory anatomy is functional. Quantitative analyses are required to decipher specific dietary and other influences on dental size and maturation in the newborn primate. PMID:26425925

Comparative clinical evaluation of two professional tooth-whitening products.

PubMed

Kowitz, G M; Nathoo, S A; Wong, R

1994-01-01

A 2-week study was conducted to compare the tooth-whitening efficacy of two 10% carbamide peroxide products: Colgate Platinum Professional Toothwhitening System and Rembrandt Lighten Bleaching Gel. Fifty subjects were divided into two groups and assigned a product to use for 2 weeks. Change in tooth color was measured by reflectance spectroscopy at the initiation of study, at 1 week, and at 2 weeks into the study. Color change was calculated using the color-difference equation established by the Commission International de L'Eclairage. Results showed that Colgate Platinum was 62% more effective at tooth whitening after 1 week and 83% more effective after 2 weeks of treatment vs Rembrandt. At the termination of the study, the mean color difference (deltaE) for Colgate Platinum was 4.29 and 2.34 for Rembrandt. Statistical analysis demonstrated that the Colgate product is significantly superior at increasing tooth whiteness, increasing tooth lightness, reducing redness, and reducing yellowness. In this study, no adverse reactions were noted on clinical examination and none were reported by panelists with normal healthy dentition.

Effect of tray-based and trayless tooth whitening systems on microhardness of enamel surface and subsurface.

PubMed

Teixeira, Erica C N; Ritter, André V; Thompson, Jeffrey Y; Leonard, Ralph H; Swift, Edward J

2004-12-01

To evaluate the effect of tray-based and trayless tooth whitening systems on surface and subsurface microhardness of human enamel. Enamel slabs were obtained from recently extracted human third molars. Specimens were randomly assigned to six groups according to tooth whitening treatment (n = 10): 6.0% hydrogen peroxide (HP) (Crest Whitestrips), 6.5% HP (Crest Professional Whitestrips), 7.5% HP (Day White Excel 3), 9.5% HP (Day White Excel 3), 10% carbamide peroxide (Opalescence), and a control group (untreated). Specimens were treated for 14 days following manufacturers' recommended protocols, and were immersed in artificial saliva between treatments. Enamel surface Knoop microhardness (KHN) was measured immediately before treatment, and at days 1, 7, and 14 of treatment. After treatment, subsurface microhardness was measured at depths of 50-500 microm. Data were analyzed for statistical significance using analysis of variance. Differences in microhardness for treated vs. untreated enamel surface were not statistically significant at any time interval. For 6.5% and 9.5% HP, there was a decrease in surface microhardness values during treatment, but at the end of treatment the microhardness values were not statistically different from the baseline values. For the enamel subsurface values, no differences were observed between treated vs. untreated specimens at each depth. Trayless and tray-based tooth whitening treatments do not significantly affect surface or subsurface enamel microhardness.

Telemetric Study of Sleep Architecture and Sleep Homeostasis in the Day-Active Tree Shrew Tupaia belangeri

PubMed Central

Coolen, Alex; Hoffmann, Kerstin; Barf, R. Paulien; Fuchs, Eberhard; Meerlo, Peter

2012-01-01

Study Objectives: In this study the authors characterized sleep architecture and sleep homeostasis in the tree shrew, Tupaia belangeri, a small, omnivorous, day-active mammal that is closely related to primates. Design: Adult tree shrews were individually housed under a 12-hr light/12-hr dark cycle in large cages containing tree branches and a nest box. The animals were equipped with radio transmitters to allow continuous recording of electroencephalogram (EEG), electromyogram (EMG), and body temperature without restricting their movements. Recordings were performed under baseline conditions and after sleep deprivation (SD) for 6 hr or 12 hr during the dark phase. Measurements and Results: Under baseline conditions, the tree shrews spent a total of 62.4 ± 1.4% of the 24-hr cycle asleep, with 91.2 ± 0.7% of sleep during the dark phase and 33.7 ± 2.8% sleep during the light phase. During the dark phase, all sleep occurred in the nest box; 79.6% of it was non-rapid eye movement (NREM) sleep and 20.4% was rapid eye movement (REM) sleep. In contrast, during the light phase, sleep occurred almost exclusively on the top branches of the cage and only consisted of NREM sleep. SD was followed by an immediate increase in NREM sleep time and an increase in NREM sleep EEG slow-wave activity (SWA), indicating increased sleep intensity. The cumulative increase in NREM sleep time and intensity almost made up for the NREM sleep that had been lost during 6-hr SD, but did not fully make up for the NREM sleep lost during 12-hr SD. Also, only a small fraction of the REM sleep that was lost was recovered, which mainly occurred on the second recovery night. Conclusions: The day-active tree shrew shares most of the characteristics of sleep structure and sleep homeostasis that have been reported for other mammalian species, with some peculiarities. Because the tree shrew is an established laboratory animal in neurobiological research, it may be a valuable model species for studies of sleep regulation and sleep function, with the added advantage that it is a day-active species closely related to primates. Citation: Coolen A; Hoffmann K; Barf RP; Fuchs E; Meerlo P. Telemetric study of sleep architecture and sleep homeostasis in the day-active tree shrew Tupaia belangeri. SLEEP 2012;35(6):879-888. PMID:22654207

The relationship between past caries experience and tooth color determined by an opto-electronic method.

PubMed

Kerosuo, E; Kolehmainen, L

1982-01-01

The susceptibility of a tooth to dental caries has been proposed to depend on tooth color. So far there has, however, been no reliable method for tooth color determination. The aims of this study were to evaluate the reliability of an opto-electronic method and to examine the relationship between tooth color and past caries experience. The color of upper right central incisors of 64 school-children was determined using an opto-electronic tri-stimulus color comparator. The intra- and interexaminer reliability of the method was evaluated in vitro and in vivo being 85% and 83%, respectively. To assess the past caries experience the DMFS-index was calculated. Oral hygiene and dietary habits were also assessed. No significant difference in DMFS scores was obtained between the 'white teeth' group and the 'yellow teeth' group. The conclusion is, that the practical importance of possible colorrelated differences in caries resistance is negligible due to the multifaceted nature of dental caries.

Short-term response of shrews to prescribed fire and mechanical fuelr eduction in a Southern Appalachian upland hardwood forest

Treesearch

Cathryn H. Greenberg; Stanlee Miller; Thomas A. Waldrop

2007-01-01

As part of the multidisciplinary National Fire and Fire Surrogate study, we used drift fences with pitfall traps from May to September 2003 and 2004 to determine how three fuel reduction techniques affected shrews in the Southern Appalachian Mountains of North Carolina. Ground dwelling macroarthropods also were collected from a subset of pitfall traps to assess...

The Trinity River Greenway: A Prototype

DTIC Science & Technology

1972-06-01

study have gone into the formulation of a multipurpose plan of management designed to tame the raging waters of the Trinity, subdue its flooding crests...TABLE 6 MAMMALS OF THE STUDY AREA Shorttail Shrew (Blarina brevicauda) Beaver (Castor canadensis) Least Shrew (Crytotis parva) Armadillo (Dasypjs...property resulted. The Trinity became an J :enemy, a raging torrent to be tamed and eventually subdued. Meanwhile, thoughful men began to realize that

Recognition memory in tree shrew (Tupaia belangeri) after repeated familiarization sessions.

PubMed

Khani, Abbas; Rainer, Gregor

2012-07-01

Recognition memories are formed during perceptual experience and allow subsequent recognition of previously encountered objects as well as their distinction from novel objects. As a consequence, novel objects are generally explored longer than familiar objects by many species. This novelty preference has been documented in rodents using the novel object recognition (NOR) test, as well is in primates including humans using preferential looking time paradigms. Here, we examine novelty preference using the NOR task in tree shrew, a small animal species that is considered to be an intermediary between rodents and primates. Our paradigm consisted of three phases: arena familiarization, object familiarization sessions with two identical objects in the arena and finally a test session following a 24-h retention period with a familiar and a novel object in the arena. We employed two different object familiarization durations: one and three sessions on consecutive days. After three object familiarization sessions, tree shrews exhibited robust preference for novel objects on the test day. This was accompanied by significant reduction in familiar object exploration time, occurring largely between the first and second day of object familiarization. By contrast, tree shrews did not show a significant preference for the novel object after a one-session object familiarization. Nonetheless, they spent significantly less time exploring the familiar object on the test day compared to the object familiarization day, indicating that they did maintain a memory trace for the familiar object. Our study revealed different time courses for familiar object habituation and emergence of novelty preference, suggesting that novelty preference is dependent on well-consolidated memory of the competing familiar object. Taken together, our results demonstrate robust novelty preference of tree shrews, in general similarity to previous findings in rodents and primates. Copyright © 2012 Elsevier B.V. All rights reserved.

Rediscovery of the type series of the Sacred Shrew, Sorex religiosus I. Geoffroy Saint-Hilaire, 1826, with additional notes on mummified shrews of ancient Egypt (Mammalia: Soricidae).

PubMed

Woodman, Neal; Koch, Claudia; Hutterer, Rainer

2017-10-30

In 1826, Isidore Geoffroy Saint-Hilaire described the Sacred Shrew, Sorex religiosus [= Crocidura religiosa] from a series of 22 embalmed individuals that comprised a portion of the Italian archeologist Joseph Passalacqua's collection of Egyptian antiquities from an ancient necropolis near Thebes, central Egypt. Living members of the species were not discovered until the beginning of the 20th century and are currently restricted to the Nile Delta region, well north of the type locality. In 1968, the type series of S. religiosus was reported lost, and in 1978, a neotype was designated from among a small collection of modern specimens in the Natural History Museum, London. Our investigations have revealed, however, that the type series is still extant. Most of the specimens used by I. Geoffroy Saint-Hilaire to describe S. religiosus still form part of the Passalacqua Collection in the Ägyptisches Museum, Berlin, Germany. We summarize the taxonomic history of S. religiosus, review the history of the Passalacqua collection, and explain why the type series was thought to have been lost. We designate an appropriate lectotype from among the original syntypes of S. religiosus in the Ägyptisches Museum. Our examination of the shrew mummies in the Passalacqua collection also yielded a species previously unrecorded from either ancient or modern Egypt: Crocidura pasha Dollman, 1915. Its presence increases the number of soricid species embalmed in ancient Egypt to seven and provides additional evidence for a more diverse Egyptian shrew fauna in the archeological past. Finally, we provide details that will assist in better understanding the variety of mummification procedures used to preserve animals in ancient Egypt.

Morphological and molecular differentiation of Staphylocystis clydesengeri n. sp. (Cestoda, Hymenolepididae) from the vagrant shrew, Sorex vagrans (Soricomorpha, Soricidae), in North America.

PubMed

Tkach, Vasyl V; Makarikov, Arseny A; Kinsella, John M

2013-01-01

Staphylocystis clydesengeri n. sp. is described from shrews Sorex vagrans in Montana and Washington, United States. It differs from the only previously known North American representative of the genus, S. schilleri, in having more numerous (37-42 vs. 22-30) and larger (39-44 microm vs. 27-30 microm) rostellar hooks. The two species also differ in several other important characters such as relative length of the cirrus pouch, position of gonads and shape of mature proglottides. Morphological differentiation of the new species from all previously known Palearctic species of Staphylocystis from Sorex is also provided. Differentiation from Staphylocystis parasitic in crocidurine shrews is not provided due to the high level of specificity among shrew hymenolepidids to the host genera and much greater levels of sequence divergence between Staphylocystis from the two groups of shrews. Molecular differentiation based on 2,800 base pair long sequences of nuclear ribosomal RNA (complete ITS region and partial 28S region), 663 base pair long sequences of mitochondrial nad1 gene and 542 base pair long sequences of mitochondrial ribosomal 16S gene strongly support the status of Staphylocystis clydesengeri n. sp. Relative utility of the DNA fragments used in this study for reliable differentiation among closely related species of mammalian hymenolepidids is discussed. Nuclear ribosomal RNA region appears to be too conserved for this purpose. Use of at least one mitochondrial gene in addition to nuclear ribosomal RNA or without it, is recommended. Vampirolepis novosibirskiensis Sawada & Kobayashi, 1994 is transferred to Staphylocystis as a junior synonym of S. furcara (Stieda, 1862). Rodentolepis gnoskei Greiman & Tkach, 2012 is transferred to Pararodentolepis Makarikov and Gulyaev, 2009 as a new combination Pararodentolepis gnoskei (Greiman & Tkach, 2012) n. comb.

Delineation of vagal emetic pathways: intragastric copper sulfate-induced emesis and viral tract tracing in musk shrews

PubMed Central

Meyers, Kelly; Lim, Audrey; Dye, Matthew; Pak, Diana; Rinaman, Linda; Yates, Bill J.

2014-01-01

Signals from the vestibular system, area postrema, and forebrain elicit nausea and vomiting, but gastrointestinal (GI) vagal afferent input arguably plays the most prominent role in defense against food poisoning. It is difficult to determine the contribution of GI vagal afferent input on emesis because various agents (e.g., chemotherapy) often act on multiple sensory pathways. Intragastric copper sulfate (CuSO4) potentially provides a specific vagal emetic stimulus, but its actions are not well defined in musk shrews (Suncus murinus), a primary small animal model used to study emesis. The aims of the current study were 1) to investigate the effects of subdiaphragmatic vagotomy on CuSO4-induced emesis and 2) to conduct preliminary transneuronal tracing of the GI-brain pathways in musk shrews. Vagotomy failed to inhibit the number of emetic episodes produced by optimal emetic doses of CuSO4 (60 and 120 mg/kg ig), but the effects of lower doses were dependent on an intact vagus (20 and 40 mg/kg). Vagotomy also failed to affect emesis produced by motion (1 Hz, 10 min) or nicotine administration (5 mg/kg sc). Anterograde transport of the H129 strain of herpes simplex virus-1 from the ventral stomach wall identified the following brain regions as receiving inputs from vagal afferents: the nucleus of the solitary tract, area postrema, and lateral parabrachial nucleus. These data indicate that the contribution of vagal pathways to intragastric CuSO4-induced emesis is dose dependent in musk shrews. Furthermore, the current neural tracing data suggest brain stem anatomical circuits that are activated by GI signaling in the musk shrew. PMID:24430885

A new hero emerges: another exceptional mammalian spine and its potential adaptive significance.

PubMed

Stanley, William T; Robbins, Lynn W; Malekani, Jean M; Mbalitini, Sylvestre Gambalemoke; Migurimu, Dudu Akaibe; Mukinzi, Jean Claude; Hulselmans, Jan; Prévot, Vanya; Verheyen, Erik; Hutterer, Rainer; Doty, Jeffrey B; Monroe, Benjamin P; Nakazawa, Yoshinori J; Braden, Zachary; Carroll, Darin; Peterhans, Julian C Kerbis; Bates, John M; Esselstyn, Jacob A

2013-10-23

The hero shrew's (Scutisorex somereni) massive interlocking lumbar vertebrae represent the most extreme modification of the vertebral column known in mammals. No intermediate form of this remarkable morphology is known, nor is there any convincing theory to explain its functional significance. We document a new species in the heretofore monotypic genus Scutisorex; the new species possesses cranial and vertebral features representing intermediate character states between S. somereni and other shrews. Phylogenetic analyses of DNA sequences support a sister relationship between the new species and S. somereni. While the function of the unusual spine in Scutisorex is unknown, it gives these small animals incredible vertebral strength. Based on field observations, we hypothesize that the unique vertebral column is an adaptation allowing these shrews to lever heavy or compressive objects to access concentrated food resources inaccessible to other animals.

Tooth color measurement using Chroma Meter: techniques, advantages, and disadvantages.

PubMed

Li, Yiming

2003-01-01

Tooth whitening has become a popular and routine dental procedure, and its efficacy and safety have been well documented. However, the measurement of tooth color, particularly in the evaluation of the efficacy of a system intended to enhance tooth whiteness, remains a challenge. One of the instruments used for assessing tooth color in clinical whitening studies is the Minolta Chroma Meter CR-321 (Minolta Corporation USA, Ramsey, NJ, USA). This article describes the instrument and discusses various measuring procedures and the Chroma Meter's advantages, limitations, and disadvantages. The available information indicates that, although Minolta Chroma Meter CR-321 provides quantitative and objective measurements of tooth color, it can be tedious to use with a custom alignment device. The Chroma Meter data are inconsistent with the commonly used visual instruments such as Vitapan Classical Shade Guide (Vita Zahnfabrik, Bad Säckingen, Germany), although in many cases the general trends are similar. It is also questionable whether the small area measured adequately represents the color of the whole tooth. A more critical challenge is the lack of methods for interpreting the Chroma Meter data regarding tooth color change in studies evaluating the efficacy of whitening systems. Consequently, at present the Chroma Meter data alone do not appear to be adequate for determining tooth color change in whitening research, although the quantitative measurements may be useful as supplemental or supportive data. Research is needed to develop and improve the instrument and technique for quantitative measurement of tooth color and interpretation of the data for evaluating tooth color change. This paper will help readers to understand the advantages and limitations of the Minolta Chroma Meter used for evaluating the efficacy of tooth-whitening systems so that proper judgment can be made in the interpretation of the results of clinical studies.

Influence of elevation and forest type on community assemblage and species distribution of shrews in the central and southern Appalachian mountains

Treesearch

W. Mark Ford; Timothy S. McCay; Michael A. Menzel; W. David Webster; Cathryn H. Greenberg; John F. Pagels; Joseph F. Merritt; Joseph F. Merritt

2005-01-01

We analyzed shrew community data from 398,832 pitfall trapnights at 303 sites across the upper Piedmont, Blue Ridge, northern Ridge and Valley, southern Ridge and Valley, Cumberland Plateau and Allegheny Mountains and Plateau sections of the central and southern Appalachian Mountains from Alabama to Pennsylvania. The objectives of our research were to describe regional...

Influence of elevation and forest type on community assemblage and species distribution of shrews in the central and southern Appalachian Mountains

Treesearch

W. Mark Ford; Timothy S. McCay; Michael A. Menzel; W. David Webster; Cathryn H. Greenberg; John F. Pagels; Joseph F. Merritt

2006-01-01

We analyzed shrew community data from 398,832 pitfall trapnights at 303 sites across the upper Piedmont, Blue Ridge, northern Ridge and Valley, southern Ridge and Valley, Cumberland Plateau and Allegheny Mountains and Plateau sections of the central and southern Appalachian Mountains from Alabama to Pennsylvania. The objectives of our research were to describe regional...

Influence of elevation and forest type on community assemblage and species distribution of shrews in the central and southern Appalachian mountains

Treesearch

W. Mark Ford; Timothy S. McCay; Michael A. Menzel; W. David Webster; Cathryn H. Greenberg; John F. Pagels; Joseph F. Merritt

2005-01-01

We analyzed shrew community data from 398,832 pitfall trapnights at 303 sites across the upper Piedmont, Blue ridge, northern Ridge and Valley, southern Ride and Valley, Cumberland Plateau and Allegheny Mountains and Plateau sections of the central and southern Appalachian Mountains from Alabama to Pennsylvania. The objectives of our research were to describe regional...

[Molecular variability in the commom shrew Sorex araneus L. from European Russia and Siberia inferred from the length polymorphism of DNA regions flanked by short interspersed elements (Inter-SINE PCR) and the relationships between the Moscow and Seliger chromosome races].

PubMed

Bannikova, A A; Bulatova, N Sh; Kramerov, D A

2006-06-01

Genetic exchange among chromosomal races of the common shrew Sorex araneus and the problem of reproductive barriers have been extensively studied by means of such molecular markers as mtDNA, microsatellites, and allozymes. In the present study, the interpopulation and interracial polymorphism in the common shrew was derived, using fingerprints generated by amplified DNA regions flanked by short interspersed repeats (SINEs)-interSINE PCR (IS-PCR). We used primers, complementary to consensus sequences of two short retroposons: mammalian element MIR and the SOR element from the genome of Sorex araneus. Genetic differentiation among eleven populations of the common shrew from eight chromosome races was estimated. The NP and MJ analyses, as well as multidimensional scaling showed that all samples examined grouped into two main clusters, corresponding to European Russia and Siberia. The bootstrap support of the European Russia cluster in the NJ and MP analyses was respectively 76 and 61%. The bootstrap index for the Siberian cluster was 100% in both analyses; the Tomsk race, included into this cluster, was separated with the bootstrap support of NJ/MP 92/95%.

Variation in the myosoricine hand skeleton and its implications for locomotory behavior (Eulipotyphla: Soricidae)

USGS Publications Warehouse

Woodman, Neal; Stabile, Frank A.

2015-01-01

Substrate use and locomotory behavior of mammals are typically reflected in external characteristics of the forefeet, such as the relative proportions of the digits and claws. Although skeletal anatomy of the forefeet can be more informative than external characters, skeletons remain rare in systematic collections. This is particularly true for the Myosoricinae (Eulipotyphla: Soricidae), a small clade of African shrews that includes both ambulatory forest shrews (Myosorex) and semifossorial mole shrews (Surdisorex). Most species in this subfamily have restricted distributions, and their behavior and ecology are mostly unstudied. To better understand the potential range of locomotory behavior among myosoricines, we used digital x-rays to image and facilitate measuring the forefoot skeletons of 9 species. As a gauge of potential variation, we compared them with the ambulatory talpid Uropsilus (Talpidae) and the semifossorial talpid Neurotrichus. The hand morphologies of myosoricines show a graded range of potential substrate use between ambulatory and semifossorial. Some of these shrews exhibit adaptations for increased burrowing efficiency that are similar to those seen in talpids and other mammals, such as longer, broader distal phalanges and claws and shorter, wider metacarpals and proximal and middle phalanges. They also, however, have characteristics that are distinct from talpids, such as maintenance of forefoot asymmetry and an increased emphasis of ray III.

Aging is accompanied by a subfield-specific reduction of serotonergic fibers in the tree shrew hippocampal formation.

PubMed

Keuker, Jeanine I H; Keijser, Jan N; Nyakas, Csaba; Luiten, Paul G M; Fuchs, Eberhard

2005-12-01

The hippocampal formation is a crucial structure for learning and memory, and serotonin together with other neurotransmitters is essential in these processes. Although the effects of aging on various neurotransmitter systems in the hippocampus have been extensively investigated, it is not entirely clear whether or how the hippocampal serotonergic innervation changes during aging. Rat studies, which have mostly focused on aging-related changes in the dentate gyrus, have implied a loss of hippocampal serotonergic fibers. We used the tree shrew (Tupaia belangeri), an intermediate between insectivores and primates, as a model of aging. We applied immunocytochemistry with an antibody against serotonin to assess serotonergic fiber densities in the various hippocampal subfields of adult (0.9-1.3 years) and old (5-7 years) tree shrews. Our results have revealed a reduction of serotonergic fiber densities in the stratum radiatum of CA1 and CA3, and in the stratum oriens of CA3. A partial depletion of serotonin in the hippocampal formation, as can be expected from our current observations, will probably have an impact on the functioning of hippocampal principal neurons. Our findings also indicate that the rat and the tree shrew hippocampal serotonergic innervation show some variations that seem to be differentially affected during aging.

Assessing monkeypox virus prevalence in small mammals at the human-animal interface in the Democratic Republic of the Congo

USGS Publications Warehouse

Doty, Jeffrey B.; Malekani, Jean M.; Kalemba, Lem's N.; Stanley, William T.; Monroe, Benjamin P.; Nakazawa, Yoshinori J.; Mauldin, Matthew R.; Bakambana, Trésor L.; Liyandja Dja Liyandja , Tobit; Braden, Zachary; Wallace, Ryan; Malekani, Divin V.; McCollum, Andrea M.; Gallardo-Romero, Nadia; Kondas, Ashley; Peterson, A. Townsend; Osorio, Jorge E.; Rocke, Tonie E.; Karem, Kevin L.; Emerson, Ginny L.; Carroll, Darin S.

2017-01-01

During 2012, 2013 and 2015, we collected small mammals within 25 km of the town of Boende in Tshuapa Province, the Democratic Republic of the Congo. The prevalence of monkeypox virus (MPXV) in this area is unknown; however, cases of human infection were previously confirmed near these collection sites. Samples were collected from 353 mammals (rodents, shrews, pangolins, elephant shrews, a potamogale, and a hyrax). Some rodents and shrews were captured from houses where human monkeypox cases have recently been identified, but most were trapped in forests and agricultural areas near villages. Real-time PCR and ELISA were used to assess evidence of MPXV infection and other Orthopoxvirus (OPXV) infections in these small mammals. Seven (2.0%) of these animal samples were found to be anti-orthopoxvirus immunoglobulin G (IgG) antibody positive (six rodents: two Funisciurus spp.; one Graphiurus lorraineus; one Cricetomys emini; one Heliosciurus sp.; one Oenomys hypoxanthus, and one elephant shrew Petrodromus tetradactylus); no individuals were found positive in PCR-based assays. These results suggest that a variety of animals can be infected with OPXVs, and that epidemiology studies and educational campaigns should focus on animals that people are regularly contacting, including larger rodents used as protein sources. 

The Taming of the Shrew

NASA Astrophysics Data System (ADS)

Gad-El-Hak, M.

1996-11-01

Considering the extreme complexity of the turbulence problem in general and the unattainability of first-principles analytical solutions in particular, it is not surprising that controlling a turbulent flow remains a challenging task, mired in empiricism and unfulfilled promises and aspirations. Brute force suppression, or taming, of turbulence via active control strategies is always possible, but the penalty for doing so often exceeds any potential savings. The artifice is to achieve a desired effect with minimum energy expenditure. Spurred by the recent developments in chaos control, microfabrication and neural networks, efficient reactive control of turbulent flows, where the control input is optimally adjusted based on feedforward or feedback measurements, is now in the realm of the possible for future practical devices. But regardless of how the problem is approached, combating turbulence is always as arduous as the taming of the shrew. The former task will be emphasized during the oral presentation, but for this abstract we reflect on a short verse from the latter. From William Shakespeare's The Taming of the Shrew. Curtis (Petruchio's servant, in charge of his country house): Is she so hot a shrew as she's reported? Grumio (Petruchio's personal lackey): She was, good Curtis, before this frost. But thou know'st winter tames man, woman, and beast; for it hath tamed my old master, and my new mistress, and myself, fellow Curtis.

Assessing Monkeypox Virus Prevalence in Small Mammals at the Human-Animal Interface in the Democratic Republic of the Congo.

PubMed

Doty, Jeffrey B; Malekani, Jean M; Kalemba, Lem's N; Stanley, William T; Monroe, Benjamin P; Nakazawa, Yoshinori U; Mauldin, Matthew R; Bakambana, Trésor L; Liyandja Dja Liyandja, Tobit; Braden, Zachary H; Wallace, Ryan M; Malekani, Divin V; McCollum, Andrea M; Gallardo-Romero, Nadia; Kondas, Ashley; Peterson, A Townsend; Osorio, Jorge E; Rocke, Tonie E; Karem, Kevin L; Emerson, Ginny L; Carroll, Darin S

2017-10-03

During 2012, 2013 and 2015, we collected small mammals within 25 km of the town of Boende in Tshuapa Province, the Democratic Republic of the Congo. The prevalence of monkeypox virus (MPXV) in this area is unknown; however, cases of human infection were previously confirmed near these collection sites. Samples were collected from 353 mammals (rodents, shrews, pangolins, elephant shrews, a potamogale, and a hyrax). Some rodents and shrews were captured from houses where human monkeypox cases have recently been identified, but most were trapped in forests and agricultural areas near villages. Real-time PCR and ELISA were used to assess evidence of MPXV infection and other Orthopoxvirus (OPXV) infections in these small mammals. Seven (2.0%) of these animal samples were found to be anti-orthopoxvirus immunoglobulin G (IgG) antibody positive (six rodents: two Funisciurus spp.; one Graphiurus lorraineus ; one Cricetomys emini ; one Heliosciurus sp.; one Oenomys hypoxanthus , and one elephant shrew Petrodromus tetradactylus ); no individuals were found positive in PCR-based assays. These results suggest that a variety of animals can be infected with OPXVs, and that epidemiology studies and educational campaigns should focus on animals that people are regularly contacting, including larger rodents used as protein sources.

Assessing the effects of tooth loss in adult crania using geometric morphometrics.

PubMed

Small, Candice; Brits, Desiré; Hemingway, Jason

2016-01-01

With high numbers of unidentified skeletonised remains recovered annually in South Africa and an increased number of edentate individuals being reported, the question arises as to whether tooth loss would result in craniofacial changes which might alter the accuracy of osteological analyses. Forty-five fixed landmarks together with sliding semilandmarks were collected from 229 white South African crania and were used to capture curve data pertaining to the basicranium, alveoli, zygomatic arches, nasal aperture and orbits. Geometric morphometric methods were employed to assess the effects of tooth loss on these structures. Although a number of effects were seen when the skull was analysed in its entirety, only the alveoli proved to be significantly affected when regions were analysed individually. Both upper facial height and palate shape were affected by tooth loss, which may influence various osteometric measurements and qualitative traits that are used during the assessment of ancestry and sex.

Cerebral involvement in axonal Charcot-Marie-Tooth neuropathy caused by mitofusin2 mutations.

PubMed

Brockmann, Knut; Dreha-Kulaczewski, Steffi; Dechent, Peter; Bönnemann, Carsten; Helms, Gunther; Kyllerman, Marten; Brück, Wolfgang; Frahm, Jens; Huehne, Kathrin; Gärtner, Jutta; Rautenstrauss, Bernd

2008-07-01

Mutations in the mitofusin 2 (MFN2) gene are a major cause of primary axonal Charcot- Marie-Tooth (CMT) neuropathy. This study aims at further characterization of cerebral white matter alterations observed in patients with MFN2 mutations. Molecular genetic, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and diffusion tensor imaging (DTI) investigations were performed in four unrelated patients aged 7 to 38 years with early onset axonal CMT neuropathy. Three distinct and so far undescribed MFN2 mutations were detected. Two patients had secondary macrocephaly and mild diffuse predominantly periventricular white matter alterations on MRI. In addition, one boy had symmetrical T2-hyperintensities in both thalami. Two patients had optic atrophy, one of them with normal MRI. In three patients proton MRS revealed elevated concentrations of total N-acetyl compounds (neuronal marker), total creatine (found in all cells) and myo-inositol (astrocytic marker) in cerebral white and gray matter though with regional variation. These alterations were most pronounced in the two patients with abnormal MRI. DTI of these patients revealed mild reductions of fractional anisotropy and mild increase of mean diffusivity in white matter. The present findings indicate an enhanced cellular density in cerebral white matter of MFN2 neuropathy which is primarily due to a reactive gliosis without axonal damage and possibly accompanied by mild demyelination.

A Study of the Potential to Detect Caries Lesions at the White-Spot Stage Using V(Z) Technique

NASA Astrophysics Data System (ADS)

Bakulin, E. Y.; Denisova, L. A.; Maev, R. Gr.

Current wide-spread methods of non-destructive methods of caries diagnostics, such as X-ray techniques, do not provide the possibility to efficiently detect enamel caries lesions at the beginning ("white-spot") stage, when the tooth tissue is only slightly altered and no loss of the tissue occurs. Therefore, it is of paramount importance to develop new, more sensitive methods of caries diagnostics. In this paper, certain aspects of the ultrasonic approach to the problem are discussed - in particular, detection of the enamel's surface caries at the white-spot stage with a focused ultrasonic sensor positioned in front of the caries lesion (without cross-sectioning the tooth). Theoretical model using V(z) approach for layered media was applied to perform computer simulations resulting in V(z) curves for the different parameters of carious tissue and the degree of degradation. The curves were analyzed and it was shown that, comparing to a short-pulse/echo technique, V(z) approach provides much better distinction between sound and carious enamel and even makes possible to evaluate the degree of demineralization.

Inference Based on Transitive Relation in Tree Shrews ("Tupaia belangeri") and Rats ("Rattus norvegicus") on a Spatial Discrimination Task

ERIC Educational Resources Information Center

Takahashi, Makoto; Ushitani, Tomokazu; Fujita, Kazuo

2008-01-01

Six tree shrews and 8 rats were tested for their ability to infer transitively in a spatial discrimination task. The apparatus was a semicircular radial-arm maze with 8 arms labeled A through H. In Experiment 1, the animals were first trained in sequence on 4 discriminations to enter 1 of the paired adjacent arms, AB, BC, CD, and DE, with right…

This shrew is a jumping mouse (Mammalia, Dipodidae): Sorex dichrurus Rafinesque 1833 is a synonym of Zapus hudsonius (Zimmermann 1780)

USGS Publications Warehouse

Woodman, Neal; Carleton, Michael D.

2012-01-01

Constantine S. Rafinesque described Sorex dichrurus as a shrew in 1833, based on a specimen he found in a proprietary museum near Niagara Falls on the New York/Ontario border. The name subsequently has been ignored by the scientific community. By describing this specimen as a shrew and ascribing it to the genus Sorex, Rafinesque clearly indicated that his species should be considered a member of the taxonomic family now recognized as the Soricidae (Mammalia, Eulipotyphla). Yet, the description of the animal, and its comparison to ‘‘Gerbillus,’’ clearly identify it as a dipodid rodent, specifically Zapus hudsonius (Zimmermann, 1780); S. dichrurus should be treated as a junior subjective synonym of that taxon. Based on its type locality of Goat Island, New York, this name is also a junior synonym of the subspecies Z. hudsonius canadensis (Davies, 1798).

A new small-eared shrew of the Cryptotis nigrescens-group from Colombia (Mammalia: Soricomorpha: Soricidae)

USGS Publications Warehouse

Woodman, N.

2003-01-01

Cryptotis colombiana Woodman & Timm, 1993 previously was known from few specimens from two isolated regions in the Cordillera Central and Cordillera Oriental of Colombia. Recent collecting in the northern Cordillera Central and review of older collections from the central Cordillera Oriental in the vicinity of Bogota yielded additional specimens that permit reevaluation of the two geographic populations of these small-eared shrews. Morphological and morphometrical studies indicate that the population inhabiting the Cordillera Oriental represents a distinct, previously unrecognized species that I describe herein as Cryptotis brachyonyx. Study of 54 specimens of shrews from the Cordillera Oriental in systematic collections in North America, South America, and Europe yielded only four specimens of the new species, all collected before 1926. The paucity of modern specimens suggests that C. brachyonyx may be extremely restricted in distribution, or possibly extinct.

Diagnosis and Management of Hidden Caries in a Primary Molar Tooth.

PubMed

Gera, Arwa; Zilberman, Uri

2017-01-01

Hidden caries is a dentinal lesion beneath the dentinoenamel junction, visible on radiographs. A single report described this lesion in primary dentition. This case report describes a case of hidden caries in a mandibular second primary molar, misdiagnosed as malignant swelling. A 3-year-old white girl was referred to the Department of Pediatric Dentistry with a chief complaint of pain and extraoral swelling on the right side of the mandible for the last 3 months. She was earlier referred to the surgical department for biopsy of the lesion. Radiographic and computed tomography scan examination showed a periapical lesion with buccal plate resorption and radiolucency beneath the enamel on the mesial part of tooth 85. The tooth was extracted, and follow-up of 2 years showed normal development of tooth 45. The main problem is early detection and treatment, since the outer surface of enamel may appear intact on tactile examination. Gera A, Zilberman U. Diagnosis and Management of Hidden Caries in a Primary Molar Tooth. Int J Clin Pediatr Dent 2017;10(1):99-102.

Red Iron-Pigmented Tooth Enamel in a Multituberculate Mammal from the Late Cretaceous Transylvanian "Haţeg Island".

PubMed

Smith, Thierry; Codrea, Vlad

2015-01-01

Mammals that inhabit islands are characterized by peculiar morphologies in comparison to their mainland relatives. Here we report the discovery of a partial skull associated with the lower jaws of a Late Cretaceous (≈70 Ma) multituberculate mammal from the Carpathian "Haţeg Island" of Transylvania, Romania. The mammal belongs to the Kogaionidae, one of the rare families that survived the Cretaceous-Paleogene mass extinction in Europe. The excellent preservation of this specimen allows for the first time description of the complete dentition of a kogaionid and demonstration that the enigmatic Barbatodon transylvanicus presents a mosaic of primitive and derived characters, and that it is phylogenetically basal among the Cimolodonta. Another peculiarity is the presence of red pigmentation in its tooth enamel. The red coloration is present on the anterior side of the incisors and on the cusps of most of the teeth. Energy-dispersive X-ray spectrometry (EDS) analysis reveals that the pigmented enamel contains iron, as in living placentals. Such a red pigmentation is known in living soricine shrews and many families of rodents, where it is thought to increase the resistance of the enamel to the abrasion that occurs during "grinding" mastication. The extended pattern of red pigment distribution in Barbatodon is more similar to that in eulipotyplan insectivores than to that in rodents and suggests a very hard diet and, importantly, demonstrates that its grasping incisors were not ever-growing. As inferred for other endemic Transylvanian vertebrates such as dwarf herbivorous dinosaurs and unusual theropod dinosaurs, insularity was probably the main factor of survival of such a primitive mammalian lineage relative to other mainland contemporaries of the Northern hemisphere.

Skeletal morphology of the forefoot in shrews (Mammalia: Soricidae) of the genus Cryptotis, as revealed by digital x-rays

USGS Publications Warehouse

Woodman, N.; Morgan, J.P.J.

2005-01-01

Variation in the forefoot skeleton of small-eared shrews (family Soricidae, genus Cryptotis) has been previously documented, but the paucity of available skeletons for most taxa makes assessment of the degrees of intraspecific and interspecific variation difficult. We used a digital X-ray system to extract images of the forefoot skeleton from 101 dried skins of eight taxa (seven species, including two subspecies of one species) of these shrews. Lengths and widths of each of the four bones of digit III were measured directly from the digital images, and we used these data to quantify variation within and among taxa. Analysis of the images and measurements showed that interspecific variation exceeds intraspecific variation. In fact, most taxa could be distinguished in multivariate and some bivariate plots. Our quantitative data helped us define a number of specific forefoot characters that we subsequently used to hypothesize evolutionary relationships among the taxa using the exhaustive search option in PAUP, a computer program for phylogenetic analysis. The resulting trees generally concur with previously published evolutionary hypotheses for small-eared shrews. Cryptotis meridensis, a taxon not previously examined in recent phylogenies, is rooted at the base of the branch leading to the C. mexicana group of species. The position of this species suggests that the mostly South American C. thomasi group shares an early ancestor with the C. mexicana group.

Molecular Survey on Brucellosis in Rodents and Shrews - Natural Reservoirs of Novel Brucella Species in Germany?

PubMed

Hammerl, J A; Ulrich, R G; Imholt, C; Scholz, H C; Jacob, J; Kratzmann, N; Nöckler, K; Al Dahouk, S

2017-04-01

Brucellosis is a widespread zoonotic disease introduced from animal reservoirs to humans. In Germany, bovine and ovine/caprine brucellosis were eradicated more than a decade ago and mandatory measures in livestock have been implemented to keep the officially brucellosis-free status. In contrast, surveillance of wildlife is still challenging, and reliable data on the prevalence of brucellae in small mammal populations do not exist. To assess the epidemiology of Brucella spp. in rodents and shrews, a molecular survey was carried out. A total of 537 rodents and shrews were trapped in four federal states located throughout Germany and investigated for the presence of Brucella. Using a two-step molecular assay based on the detection of the Brucella-specific bcsp31 and IS711 sequences in tissue samples, 14.2% (n = 76) of the tested animals were positive. These originated mainly from western and south-western Germany, where preliminary analyses indicate population density-dependent Brucella prevalence in voles (Myodes glareolus) and mice (Apodemus spp.). recA typing revealed a close relationship to a potentially novel Brucella species recently isolated from red foxes (Vulpes vulpes) in Austria. The molecular detection of brucellae in various rodent taxa and for the first time in shrew species shows that these animals may be naturally infected or at least have a history of exposure to Brucella spp. © 2015 Blackwell Verlag GmbH.

Associative memory or algorithmic search: a comparative study on learning strategies of bats and shrews.

PubMed

Page, Rachel A; von Merten, Sophie; Siemers, Björn M

2012-07-01

Two common strategies for successful foraging are learning to associate specific sensory cues with patches of prey ("associative learning") and using set decision-making rules to systematically scan for prey ("algorithmic search"). We investigated whether an animal's life history affects which of these two foraging strategies it is likely to use. Natterer's bats (Myotis nattereri) have slow life-history traits and we predicted they would be more likely to use associative learning. Common shrews (Sorex araneus) have fast life-history traits and we predicted that they would rely more heavily on routine-based search. Apart from their marked differences in life-history traits, these two mammals are similar in body size, brain weight, habitat, and diet. We assessed foraging strategy, associative learning ability, and retention time with a four-arm maze; one arm contained a food reward and was marked with four sensory stimuli. Bats and shrews differed significantly in their foraging strategies. Most bats learned to associate the sensory stimuli with the reward and remembered this association over time. Most shrews searched the maze using consistent decision-making rules, but did not learn or remember the association. We discuss these results in terms of life-history traits and other key differences between these species. Our results suggest a link between an animal's life-history strategy and its use of associative learning.

Stages and transitions in the development of tooth brushing skills in children of Mexican immigrant families: a qualitative study.

PubMed

Benadof, Dafna; Polk, Deborah; Documet, Patricia

2015-01-01

Compared with white children, the oral health of Latino children in the United States is much worse. One factor contributing to oral health is tooth brushing. Few studies have addressed the formation of the tooth brushing habit in children, and only one of them studied a Latino population. The purpose of this study is to explore the development of the tooth brushing habit in children of Mexican immigrant families and develop hypothesis based on its results. This is an exploratory qualitative study, with a case study design based on 20 in-depth interviews. Participants were Mexican immigrant mothers living in Pittsburgh and Philadelphia, PA. Participants had at least one child six-years-old or younger. Interviews were recorded, transcribed verbatim, and analyzed using qualitative analysis procedures. Four stages were identified in the tooth brushing learning process: initiation and entirely dependent tooth brushing, assisted tooth brushing, road to tooth brushing independence, and independent tooth brushing. Two factors influenced parents' teaching approaches: parents' perceptions of their child's achievement of physical, cognitive, and motor developmental milestones and parents' knowledge about oral hygiene. We identified four distinct stages and found evidence to hypothesize that transitions from one stage to the next are triggered not by the age of the child but by parents' knowledge about oral hygiene and their perceptions of their child's achievement of physical, cognitive, and motor developmental milestones. Future quantitative research studies should be conducted to test this hypothesis in larger groups of Latinos as well as other ethnic groups. © 2015 American Association of Public Health Dentistry.

The bleaching of teeth: a review of the literature.

PubMed

Joiner, Andrew

2006-08-01

To review current knowledge of tooth whitening with respect to external bleaching methods. The scope is the external bleaching of vital teeth and focuses on mechanisms; in vivo and in vitro measurement methods, and factors influencing the efficacy of the whitening process. "Medline" and "ISI Web of Science" databases from 1966 and 1974, respectively were searched electronically with key words tooth, teeth, colo*r, white*, bleach* and peroxide. The importance of tooth whitening for patients and consumers has seen a dramatic increase in the number of products and procedures over recent years, with a concomitant rise in publications on this topic. Literature suggests that the mechanisms of tooth whitening by peroxide occur by the diffusion of peroxide through enamel to cause oxidation and hence lightening of coloured species, particularly within the dentinal regions. A number of approaches are available for measuring changes in tooth colour. These include visual measurements by trained clinicians and instrumental measurements using spectrophotometry, chromameters and digital image analysis. The key factors that affect tooth whitening efficacy by peroxide containing products are concentration and time. In general, higher concentrations are faster than lower concentrations. However, lower concentrations can approach the efficacy of higher concentrations with extended treatment times. Alternative bleach systems to peroxide have received only minor attention. The efficacy of light activated systems versus non-light activated controls in clinical studies is limited and conflicting. Other factors which can influence tooth bleaching outcome include type of stain, initial tooth colour and subject age.

Abundance & distribution of trombiculid mites & Orientia tsutsugamushi, the vectors & pathogen of scrub typhus in rodents & shrews collected from Puducherry & Tamil Nadu, India.

PubMed

Candasamy, Sadanandane; Ayyanar, Elango; Paily, Kummankottil; Karthikeyan, Patricia Anitha; Sundararajan, Agatheswaran; Purushothaman, Jambulingam

2016-12-01

Human cases of scrub typhus are reported every year from Puducherry and adjoining areas in southern India. However, information on the presence of causative agent, Orientia tsutsugamushi, and its vectors is lacking. Hence, the objective of the study was to find out the vector as well as pathogen distribution in rodents and shrews present in the scrub typhus-reported areas in southern India. Trombiculid mites were collected by combing rats and shrews collected using Sherman traps and identified to species level following standard taxonomical keys. The serum samples of the animals were used for Weil-Felix test and the clots containing blood cells were used for DNA extraction and polymerase chain reaction (PCR). A total of 181 animals comprising four rodent species and one shrew species were collected from 12 villages. High proportion of chiggers was collected from the shrew, Suncus murinus (79.1%) and Rattus rattus (47.6%). A total of 10,491 trombiculid mites belonging to nine species were collected. Leptotrombidium deliense, the known vector of scrub typhus pathogen, was the predominant species (71.0%) and the chigger (L. deliense) index was 41.1 per animal. Of the 50 animals screened for the pathogen, 28 showed agglutination against OX-K in Weil-Felix test indicating the presence of antibodies against O. tsutsugamushi, the causative agent of scrub typhus. PCR carried out with the DNA extracted from blood samples of two of the animals were positive for GroEl gene of O. tsutsugamushi. L. deliense index was well above the critical limit of chigger load, indicating that all the villages were receptive for high risk of transmission of scrub typhus to human. Pathogen positivity was higher among animals collected from villages recorded for higher chigger indices due to active transmission between the chigger mites and reservoir host animals. The results are suggestive of routine vector/pathogen surveillance at hot spots to initiate timely preventive measures.

Imaginary Figures of Early Childhood: Santa Claus, Easter Bunny, and the Tooth Fairy.

ERIC Educational Resources Information Center

Prentice, Norman M.; And Others

1978-01-01

The developmental progression of belief in three major imaginary figures of early childhood was examined in 20 White, Christian children (ages four to eight years) by means of interviews and parental questionnaires. (Author/DLS)

Evidence of Early Emergence of the Primary Dentition in a Northern Plains American Indian Population.

PubMed

Dawson, D V; Blanchette, D R; Douglass, J M; Tinanoff, N; Kramer, K W O; Warren, J J; Phipps, K R; Starr, D E; Marshall, T A; Mabry, T R; Pagan-Rivera, K; Banas, J A; Drake, D R

2018-04-01

The purposes of this study were to describe primary tooth emergence in an American Indian (AI) population during the first 36 mo of life to compare 1) patterns of emergence between male and female children and 2) tooth emergence between these AI children and other U.S. ethnic groups. Data were derived from a birth cohort of 239 AI children from a Northern Plains tribe participating in a longitudinal study of early childhood caries, with examination data at target ages of 8, 12, 16, 22, 28, and 36 mo of age (±1 mo). Patterns of emergence in AI children were characterized and sex comparisons accomplished with interval-censored survival methodology. Numbers of erupted teeth in AI children at each age were compared via Kruskal-Wallis tests against those in children of the same age, as drawn from a cross-sectional study of dental caries patterns in Arizona; these comparisons were based on the dental examinations of 547 White non-Hispanic and 677 Hispanic children. Characterization of time to achievement of various milestones-including emergence of the anterior teeth, the first molars, and the complete primary dentition-provided no evidence of sex differences among AI children. AI children had significantly more teeth present at 8 mo (median, 3) than either White non-Hispanic ( P < 0.0063) or Hispanic ( P < 0.0001) children (median, 2 each). This was also true at 12 mo ( P < 0.001; medians, 8 vs. 6 and 7, respectively) and 16 mo ( P < 0.001; medians, 12 vs. 11 each). Less pronounced differences were seen at 22 mo ( P < 0.0001). White non-Hispanic and Hispanic children did not differ at any time considered ( P > 0.05). These results provide evidence of earlier tooth emergence in AI children than in the other 2 ethnicities. Although the underlying etiology of the severity of early childhood caries in AI children is likely to be multifactorial, earlier tooth emergence may be a contributing factor. Knowledge Transfer Statement: The findings of this study have practical implications for practitioners providing childhood oral health care to ethnic groups with early tooth emergence. It may be important to provide parents with information on toothbrushing, dentist visits, and other practices supportive of good oral health as early as possible to protect their children's primary dentition.

Final Environmental Impact Statement. F-15E Beddown at Seymour Johnson AFB, North Carolina

DTIC Science & Technology

1988-11-18

beetle; and the following threatened species: artic peregrine falcon, piping plover, dismal swamp southeastern shrew , green sea turtle, and the log...Fish and Wildlife Service’s Raleigh Field Office. There would be no construction activity in the habitats of the shrew and tiger beetle and the Iong...sAadd .. 4 P~loqh/ DIN Z7-~2S ’UL 16 󈨡 9:31 703 614 7572 PAGE.002 DISGLAIMUJ NOTIGI THIS DOCUMENT IS BEST QUALITY AVAILABLE. THE COPY FURNISHED TO

A new species of small-eared shrew of the genus Cryptotis (Mammalia, Eulipotyphla, Soricidae) from the northernmost Peruvian Andes.

PubMed

Zeballos, Horacio; Pino, Kateryn; Medina, CÉsar E; Pari, Alexander; ChÁvez, Daniel; Tinoco, NicolÁs; Ceballos, Gerardo

2018-01-31

The northernmost Peruvian Andes, a unique biogeographic region characterized by the confluence of multiple distinct ecosystems (i.e. Amazon basin, Pacific rainforest, the Sechura Desert, the northern and central Andes), is the southernmost geographic range limit of the South American shrews representing the genus Cryptotis. In the northernmost Peruvian Andes, two poorly known species have traditionally been reported (C. peruviensis and C. equatoris). Our study, based on molecular and morphologic traits, confirms the presence of C. peruviensis but also the occurrence of C. montivaga, based on specimens erroneously assigned to C. equatoris. Moreover, a new species of Cryptotis from the páramo and montane forests of the Tabaconas Namballe National Sanctuary near the Ecuadorian border is also described. It is a member of the thomasi group and is distinguished from other South American shrews by a unique set of morphological characters, including large body size, comparatively short tail, simple ectoloph of M3, and large PM4 post protocrista.

Effectiveness of a new non-hydrogen peroxide bleaching agent after single use - a double-blind placebo-controlled short-term study.

PubMed

Bizhang, Mozhgan; Domin, Julia; Danesh, Gholamreza; Zimmer, Stefan

2017-01-01

Tooth whitening represents perhaps the most common aesthetic procedure in dentistry worldwide. The efficacy of bleaching depends on three aspects: bleaching agent, bleaching method, and tooth color. This in vivo study aimed to examine whitening effects on frontal teeth of the upper and lower jaws using an over-the-counter (OTC) non-hydrogen peroxide bleaching agent in comparison to a placebo after one single use. Forty subjects (25 female; 15 male) participated in this double-blind randomized placebo-controlled trial. The subjects were randomly allocated to two groups (n=20). The test group received the OTC product (iWhite Instant) and the placebo group received an identically composed product except for the active agents. Each subject was treated with a prefilled tray containing iWhite Instant or the placebo for 20 minutes. The tooth shade of the front teeth (upper and lower jaws) was assessed before (E_0), immediately after (E_1) and 24 h after treatment (E_2), using a shade guide (VITA classical). Statistical testing was accomplished using the Mann-Whitney U test (p<0.001). The dropout rate was 0%. There were no significant differences at E_0 between placebo and test groups regarding the tooth color. Differences in tooth color changes immediately after (ΔE1_0) and 24 h after treatment (ΔE2_0) were calculated for both groups. The mean values (standard deviations) of tooth color changes for ΔE1_0 were 2.26 (0.92) in the test group and 0.01 (0.21) in the placebo group. The color changes for ΔE2_0 showed mean values of 2.15 (1.10) in the test group and 0.07 (0.35) in the placebo group. For ΔE1_0 and ΔE2_0 significant differences were found between the groups. In this short-term study, the results showed that a non-hydrogen peroxide bleaching agent has significant whitening effects immediately and 24 h after a single-use treatment.

Carving out turf in a biodiversity hotspot: multiple, previously unrecognized shrew species co-occur on Java Island, Indonesia.

PubMed

Esselstyn, Jacob A; Maharadatunkamsi; Achmadi, Anang S; Siler, Cameron D; Evans, Ben J

2013-10-01

In theory, competition among species in a shared habitat results in niche separation. In the case of small recondite mammals such as shrews, little is known about their autecologies, leaving open questions regarding the degree to which closely related species co-occur and how or whether ecological niches are partitioned. The extent to which species are able to coexist may depend on the degree to which they exploit different features of their habitat, which may in turn influence our ability to recognize them as species. We explored these issues in a biodiversity hotspot, by surveying shrew (genus Crocidura) diversity on the Indonesian island of Java. We sequenced portions of nine unlinked genes in 100-117 specimens of Javan shrews and incorporated homologous data from most known Crocidura species from other parts of island South-East Asia. Current taxonomy recognizes four Crocidura species on Java, including two endemics. However, our phylogenetic, population genetic and species delimitation analyses identify five species on the island, and all are endemic to Java. While the individual ranges of these species may not overlap in their entirety, we found up to four species living syntopically and all five species co-occurring on one mountain. Differences in species' body size, use of above ground-level habitats by one species and habitat partitioning along ecological gradients may have facilitated species diversification and coexistence. © 2013 John Wiley & Sons Ltd.

Superovulation induction in the house musk shrew (Suncus murinus).

PubMed

Matsuzaki, T; Matsuzaki, K; Yokoyama, M; Yamada, S; Saito, M

1997-07-01

The number of ovulated oocytes in the adult house musk shrews was examined by natural mating. The positive rate of ovulation was 83.3%, and the mean number of ovulated oocytes was 4.4 +/- 1.9 (Mean +/- SD). The induction of superovulation was examined by administering either pregnant mare's serum gonadotropin (PMSG) or human chorionic gonadotropin (hCG), exogenous gonadotropin, to house musk shrews. As a result, the number of ovulated oocytes were within the number of oocytes ovulated spontaneously. The method of superovulation induction by administering both PMSG and hCG to house musk shrews was investigated. In the group intraperitoneally with 7.5 i.u. of PMSG followed by 7.5 i.u. of hCG 48 hr later, the positive rate of ovulation was as high as 94.6% and the mean number of ovulated oocytes was 11.7 +/- 13.4. Moreover, in 15 out of these 35 animals positive for ovulation, 10 oocytes or more were observed and the mean number of ovulated oocytes was 21.0 +/- 16.5, showing the superovulatory response. In the group of 5.0 i.u. PMSG and 5.0 i.u. hCG injected at an interval of 72 hr, every animal was induced to ovulate and the mean number of ovulated oocytes was 41.3 +/- 19.9. Thus, the injection of PMSG and hCG at a longer interval increased the number of superovulated oocytes. Furthermore, 97.5% of eggs recovered from superovulating animals contained cumulus cells.

Evolutionary Insights from a Genetically Divergent Hantavirus Harbored by the European Common Mole (Talpa europaea)

PubMed Central

Kang, Hae Ji; Bennett, Shannon N.; Sumibcay, Laarni; Arai, Satoru; Hope, Andrew G.; Mocz, Gabor; Song, Jin-Won; Cook, Joseph A.; Yanagihara, Richard

2009-01-01

Background The discovery of genetically distinct hantaviruses in shrews (Order Soricomorpha, Family Soricidae) from widely separated geographic regions challenges the hypothesis that rodents (Order Rodentia, Family Muridae and Cricetidae) are the primordial reservoir hosts of hantaviruses and also predicts that other soricomorphs harbor hantaviruses. Recently, novel hantavirus genomes have been detected in moles of the Family Talpidae, including the Japanese shrew mole (Urotrichus talpoides) and American shrew mole (Neurotrichus gibbsii). We present new insights into the evolutionary history of hantaviruses gained from a highly divergent hantavirus, designated Nova virus (NVAV), identified in the European common mole (Talpa europaea) captured in Hungary. Methodology/Principal Findings Pair-wise alignment and comparison of the full-length S- and L-genomic segments indicated moderately low sequence similarity of 54–65% and 46–63% at the nucleotide and amino acid levels, respectively, between NVAV and representative rodent- and soricid-borne hantaviruses. Despite the high degree of sequence divergence, the predicted secondary structure of the NVAV nucleocapsid protein exhibited the characteristic coiled-coil domains at the amino-terminal end, and the L-segment motifs, typically found in hantaviruses, were well conserved. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, showed that NVAV formed a distinct clade that was evolutionarily distant from all other hantaviruses. Conclusions Newly identified hantaviruses harbored by shrews and moles support long-standing virus-host relationships and suggest that ancestral soricomorphs, rather than rodents, may have been the early or original mammalian hosts. PMID:19582155

Reduced wear of enamel with novel fine and nano-scale leucite glass-ceramics.

PubMed

Theocharopoulos, Antonios; Chen, Xiaohui; Hill, Robert; Cattell, Michael J

2013-06-01

Leucite glass-ceramics used to produce all-ceramic restorations can suffer from brittle fracture and wear the opposing teeth. High strength and fine crystal sized leucite glass-ceramics have recently been reported. The objective of this study is to investigate whether fine and nano-scale leucite glass-ceramics with minimal matrix microcracking are associated with a reduction in in vitro tooth wear. Human molar cusps (n=12) were wear tested using a Bionix-858 testing machine (300,000 simulated masticatory cycles) against experimental fine crystal sized (FS), nano-scale crystal sized (NS) leucite glass-ceramics and a commercial leucite glass-ceramic (Ceramco-3, Dentsply, USA). Wear was imaged using Secondary Electron Imaging (SEI) and quantified using white-light profilometry. Both experimental groups were found to produce significantly (p<0.05) less volume and mean-height tooth loss compared to Ceramco-3. The NS group had significantly (p<0.05) less tooth mean-height loss and less combined (tooth and ceramic) loss than the FS group. Increased waviness and damage was observed on the wear surfaces of the Ceramco-3 glass-ceramic disc/tooth group in comparison to the experimental groups. This was also indicated by higher surface roughness values for the Ceramco-3 glass-ceramic disc/tooth group. Fine and nano-sized leucite glass-ceramics produced a reduction in in vitro tooth wear. The high strength low wear materials of this study may help address the many problems associated with tooth enamel wear and restoration failure. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparative anatomy of the foramen ovale in the hearts of cetaceans

PubMed Central

Macdonald, Alastair A; Carr, Peter A; Currie, Richard J W

2007-01-01

The structure of the cardiac foramen ovale from 17 species representing six cetacean families, the Monodontidae, Phocoenidae, Delphinidae, Ziphiidae, Balaenidae and the Balaenopteridae, was studied using the scanning electron microscope. Eight white whale fetuses (Delphinapterus leucas) and a narwhal fetus (Monodon monoceros) represented the Monodontidae; one fetal and nine neonatal harbour porpoises (Phocoena phocoena) and a finless porpoise fetus (Neophocoena phocoenoides) represented the Phocoenidae; two white-beaked dolphin fetuses (Lagenorhynchus albirostris), four fetal and one neonatal Atlantic white-sided dolphins (Lagenorhynchus acutus), a Risso's dolphin fetus (Grampus griseus), two common bottle-nosed dolphin neonates (Tursiops truncatus), a female short-beaked common dolphin fetus (Delphinus delphis), four killer whale fetuses (Orcinus orca) and two long-finned pilot whale fetuses (Globicephala melas) represented the Delphinidae; two northern bottlenose whale fetuses (Hyperoodon ampullatus) represented the Ziphiidae; one bowhead whale fetus (Balaena mysticetus) represented the Balaenidae and five Common minke whale fetuses (Balaenoptera acutorostrata), one blue whale fetus (Balaenoptera musculus), nine fin whale fetuses (Balaenoptera physalus) and four humpback whale fetuses (Megaptera novaeangliae) represented the Balaenopteridae. The hearts of an additional two incompletely identified toothed and four baleen whale fetuses were also studied. In each species the fold of tissue derived from the cardiac septum primum and subtended by the foramen ovale had the appearance of a short tunnel or sleeve which was fenestrated at its distal end. In the toothed whales the tissue fold was tunnel-shaped with the interatrial septum as the floor whereas in baleen whales it was more sleeve-like. In toothed whales thin threads extended from the fold to insert into the interatrial septum whereas a network of threads covered the distal end of the sleeve in the baleen whales. Similar structures were present in the corresponding cardiac tissues of neonatal Hippopotamidae. PMID:17532800

A new distinctively banded-species of Panaqolus (Siluriformes: Loricariidae) from the western Amazon Basin in Peru.

PubMed

Lujan, Nathan K; Steele, Sarah; Velasquez, Miquel

2013-01-01

Panaqolus albivermis is described as a new species based on four specimens from the San Alejandro River, a tributary of the upper Ucayali River in central Peru. Panaqolus albivermis is diagnosed from all other Panaqolus except P. maccus by having head, body, and fins with widely separated small white to yellow spots, vermiculations, and/or thin oblique bands on a black base (vs. exclusively small white to yellow spots on a black base in P. alboinaculatus, generally broad oblique bands of alternating light to dark brown in P. changae, P. gnomus, P purusiensis, and a uniformly dark gray to black body color in P. dentex, P. koko, and P. nocturnus); P. albivernis can be diagnosed from P. maccus by having a black base color (vs. brown), by having parallel dentary tooth cups (vs. acute intermandibular tooth cup angle), and by having a larger known adult body size (95.8 mm SL vs. 84.8).

[White spot lesions and orthodontic treatment. Prevention and treatment].

PubMed

Morrier, Jean-Jacques

2014-09-01

Decalcification of the enamel surface adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a common and frequent well-known side-effect of orthodontic treatment. Fixed appliances and the bonding materials increase the retention of biofilm and encourage the formation of white spot lesions. Management of these lesions begins with a good oral hygiene regime and needs to be associated with use of fluoride agents (fluoridated toothpaste, fluoride containing mouth rinse, gel, varnish, bonding materials, elastic ligature), CPP-ACP, antiseptics, LASER, tooth whitening, resin infiltration, micro-abrasion. The purpose of this review is to access the direct evidence regarding the prevention and management of white spot lesions during and after orthodontic treatment. © EDP Sciences, SFODF, 2014.

Predicting improvement of postorthodontic white spot lesions.

PubMed

Kim, Susan; Katchooi, Mina; Bayiri, Burcu; Sarikaya, Mehmet; Korpak, Anna M; Huang, Greg J

2016-05-01

Patients undergoing orthodontic treatment are at greater risk for developing white spot lesions (WSLs). Although prevention is always the goal, WSLs continue to be a common sequela. For this reason, understanding the patterns of WSL improvement, if any, has great importance. Previous studies have shown that some lesions exhibit significant improvement, whereas others have limited or no improvement. Our aim was to identify specific patient-related and tooth-related factors that are most predictive of improvement with treatment. Patients aged 12 to 20 years with at least 1 WSL that developed during orthodontic treatment were recruited from private dental and orthodontic offices. They had their fixed appliances removed 2 months or less before enrollment. Photographs were taken at enrollment and 8 weeks later. Paired photographs of the maxillary incisors, taken at each time point, were blindly assessed for changes in surface area and appearance at the individual tooth level using visual inspection. One hundred one subjects were included in this study. Patient age, brushing frequency, and greater percentage of surface area affected were associated with increased improvement. Central incisors exhibited greater improvements than lateral incisors. Longer time since appliance removal and longer length of orthodontic treatment were associated with decreased levels of improvement. Sex, oral hygiene status, retainer type, location of the lesion (gingival, middle, incisal), staining, and lesion diffuseness were not found to be predictive of improvement. Of the various patient-related and tooth-related factors examined, age, time since appliance removal, length of orthodontic treatment, tooth type (central or lateral incisor), WSL surface area, and brushing frequency had significant associations with WSL improvement. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

A chromosome painting test of the basal eutherian karyotype.

PubMed

Svartman, Marta; Stone, Gary; Page, John E; Stanyon, Roscoe

2004-01-01

We studied the chromosomes of an Afrotherian species, the short-eared elephant shrew Macroscelides proboscideus with traditional banding techniques and mapped the homology to human chromosomes by in-situ hybridization of human chromosome paints. Here we present for the first time the karyotype of this species, including banding patterns. The chromosome painting allowed us to test various hypotheses of the ancestral Eutherian karyotype, the validity of the radical taxonomic assemblage known as Afrotheria and the phylogenetic position of the elephant shrew within the Afrotheria. Current hypotheses concerning the Eutherian ancestral karyotype include diploid numbers ranging from 2n = 44 to 50 while molecular studies have proposed a new superordinal grouping of extant Eutherians. In particular, the Afrotheria is hotly debated, as it appears to be an odd mixture of species from Ungulata, Tubulidentata, Macroscelidea and Lipotyphla, which have no apparent morphological traits to unite them. The hybridization pattern delimited a total of 37 segments in the elephant shrew genome and revealed 21 different associations of human chromosome segments. Associations 1/19 and 5/21 link all Afrotheria so far studied and support the Afrotheria assemblage. Associations 2/8, 3/20, and 10/17 strongly link aardvarks and elephant shrews after the divergence of the line leading to elephants. The most likely ancestral Eutherian karyotype would be 2n = 48 chromosomes. However, the lack of comparative chromosome painting data between Eutherians and an appropriate outgroup is a severe limitation on attempts to delineate the ancestral genome of Eutherians. Current attempts lack legitimacy until this situation is corrected.

The central nervous system phenotype of X-linked Charcot-Marie-Tooth disease: a transient disorder of children and young adults.

PubMed

Al-Mateen, Majeed; Craig, Alexa Kanwit; Chance, Phillip F

2014-03-01

We describe 2 patients with X-linked Charcot-Marie-Tooth disease, type 1 (CMTX1) disease and central nervous system manifestations and review 19 cases from the literature. Our first case had not been previously diagnosed with Charcot-Marie-Tooth disease, and the second case, although known to have Charcot-Marie-Tooth disease, was suspected of having CMTX1 after presentation with central nervous system manifestations. The most common central nervous system manifestations were transient and included dysarthria, ataxia, hemiparesis, and tetraparesis resembling periodic paralysis. Of the 21 patients, 19 presented at 21 years of age or younger, implicating CMTX1 with transient central nervous system manifestations as a disorder that predominantly affects children and adolescents. CMTX1 should be included in the differential diagnosis of patients who present with transient central nervous system phenomena, including stroke-like episodes, tetraparesis suggestive of periodic paralysis, dysarthria, ataxia, or combinations of these deficits. Reversible, bilateral, nonenhancing white matter lesions and restricted diffusion on magnetic resonance imaging are characteristic features of the central nervous system phenotype of CMTX1.

Size of the great white shark (carcharodon).

PubMed

Randall, J E

1973-07-13

The maximum length of 36.5 feet (11.1 meters) attributed to the white shark (Carcharodon carcharias) by Günther and others is a mistake. Examination of the jaws and teeth of the specimen referred to by Günther and comparison with the jaws of white sharks of known length revealed a length of about 17 feet ( approximately 5 meters). The largest white shark reliably measured was a 21-foot (6.4-meter) individual from Cuba. Bites on whale carcasses found off southern Australia suggest that white sharks as long as 25 or 26 feet (7 (1/2) or 8 meters) exist today. The size of extinct Carcharodon has also been grossly exaggerated. Based on a projection of a curve of tooth size of Recent Carcharodon carcharias, the largest fossil Carcharodon were about 43 feet ( approximately 13 meters) long.

Size evolution in Goodwin’s small-eared shrew, Cryptotis goodwini

USGS Publications Warehouse

Woodman, N.; Merritt, J.F.; Churchfield, S.; Hutterer, R.; Sheftel, B.A.

2005-01-01

Fossils of Cryptotis goodwini from Honduras indicate that body sizes of modern individuals average at least 18% larger than among members of the late Pleistocene population of this species. Palynological and other paleoenvironmental studies provide evidence that the Neotropical montane environments that these shrews inhabit were cooler and drier in the late Pleistocene than at present and supported communities of plants without modern analog. Therefore, the most likely cause of this change in size ultimately was related to climatic change at the end of the Pleistocene?but to what specific factors did the species respond? I examined the possibilities that this species changed in size: to accommodate a change in temperature regime; to escape from predators; as a response to a change in intensity of interspecific competition; to take advantage of a newly abundant food resource. Based on evidence from studies of modern communities of shrews and niche partitioning, I hypothesized that size evolution in C. goodwini was directly related to changes in the community of soil and soil-surface invertebrates upon which the species depends, specifically an increase in the availability of earthworms (Annelida).

Accumulation of Methylmercury in Invertebrates and Masked Shrews (Sorex cinereus) at an Upland Forest-Peatland Interface in Northern Minnesota, USA.

PubMed

Tavshunsky, Ilana; Eggert, Susan L; Mitchell, Carl P J

2017-12-01

Mercury (Hg) methylation is often elevated at the terrestrial-peatland interface, but methylmercury (MeHg) production at this "hot spot" has not been linked with in situ biotic accumulation. We examined total Hg and MeHg levels in peat, invertebrates and tissues of the insectivore Sorex cinereus (masked shrew), inhabiting a terrestrial-peatland ecotone in northern Minnesota, USA. Mean MeHg concentrations in S. cinereus (71 ng g -1 ) fell between concentrations measured in spiders (mean 70-140 ng g -1 ), and ground beetles and millipedes (mean 29-42 ng g -1 ). Methylmercury concentrations in S. cinereus increased with age and differed among tissues, with highest concentrations in kidneys and muscle, followed by liver and brain. Nearly all Hg in S. cinereus was in the methylated form. Overall, the high proportional accumulation of MeHg in peat at the site (3.5% total Hg as MeHg) did not lead to particularly elevated concentrations in invertebrates or shrews, which are below values considered a toxicological risk.

Dental caries detection by optical spectroscopy: a polarized Raman approach with fibre-optic coupling

NASA Astrophysics Data System (ADS)

Ko, A. C.-T.; Choo-Smith, L.-P.; Werner, J.; Hewko, M.; Sowa, M. G.; Dong, C.; Cleghorn, B.

2006-09-01

Incipient dental caries lesions appear as white spots on the tooth surface; however, accurate detection of early approximal lesions is difficult due to limited sensitivity of dental radiography and other traditional diagnostic tools. A new fibre-optic coupled spectroscopic method based on polarized Raman spectroscopy (P-RS) with near-IR laser excitation is introduced which provides contrast for detecting and characterizing incipient caries. Changes in polarized Raman spectra are observed in PO 4 3- vibrations arising from hydroxyapatite of mineralized tooth tissue. Demineralization-induced morphological/orientational alteration of enamel crystallites is believed to be responsible for the reduction of Raman polarization anisotropy observed in the polarized Raman spectra of caries lesions. Supporting evidence obtained by polarized Raman spectral imaging is presented. A specially designed fibre-optic coupled setup for simultaneous measurement of parallel- and cross-polarized tooth Raman spectra is demonstrated in this study.

Color masking of developmental enamel defects: a case series.

PubMed

Torres, C R G; Borges, A B

2015-01-01

Developmental defects involving color alteration of enamel frequently compromise the esthetic appearance of the tooth. The resin infiltration technique represents an alternative treatment for color masking of these lesions and uniformization of tooth color. This technique is considered relatively simple and microinvasive, since only a minimal portion of enamel is removed. This article illustrates the color-masking effect with resin infiltration of fluorosis and traumatic hypomineralization lesions with a case series. The final esthetic outcomes demonstrated the ability of the resin infiltrant to mask the color of white developmental defect lesions, resulting in satisfactory clinical esthetic improvements. However, in more severe cases, the color-masking effect was not complete.

Effects of a New Bleaching Gel on Tooth Whitening

DTIC Science & Technology

2016-05-17

that claims "wow’’ results and permanent whiteness unaffected by consumption of coffee, tea, or red wine with low to no sensitivity. KOR has also...bleaching to result in greater lightness {delta L *)than Home bleaching, suggesting no overall benefit from either technique. Two recent clinical

Effect of a New Bleaching Gel on Tooth Whitening

DTIC Science & Technology

2016-05-12

that claims “wow” results and permanent whiteness unaffected by consumption of coffee, tea, or red wine with low to no sensitivity. KöR has also...tendency for Combined bleaching to result in greater lightness (delta L*) than Home bleaching, suggesting no overall benefit from either technique

Profound seasonal shrinking and regrowth of the ossified braincase in phylogenetically distant mammals with similar life histories

PubMed Central

Dechmann, Dina K. N.; LaPoint, Scott; Dullin, Christian; Hertel, Moritz; Taylor, Jan R. E.; Zub, Karol; Wikelski, Martin

2017-01-01

Ontogenetic changes in skull shape and size are ubiquitous in altricial vertebrates, but typically unidirectional and minimal in full-grown animals. Red-toothed shrews exhibit a rare exception, where the shape, mass and size of the skull, brain, and several major organs, show significant bidirectional seasonal changes. We now show a similar but male-biased shrinking (16%) and regrowth (8%) in the standardized braincase depth of least weasels (Mustela nivalis). Juvenile weasels also exhibit a growth overshoot, followed by a shrinkage period lasting until the end of their first winter. Only male weasels then regrow during their second summer. High-resolution CT scans suggest areas of the skull are affected differently during shrinking and regrowth in both species. This suggests multiple evolutionary drivers: while the shrinking likely facilitates survival during seasonal low resource availability in these high-metabolic mammals with year-round activity, the regrowth may be most strongly influenced by high investment into reproduction and territories, which is male-biased in the weasels. Our data provide evidence for convergent evolution of skull and thus brain shrinkage and regrowth, with important implications for understanding adaptations to changing environments and for applied research on the correlated changes in bone structure, brain size and the many other affected organs. PMID:28211896

Profound seasonal shrinking and regrowth of the ossified braincase in phylogenetically distant mammals with similar life histories.

PubMed

Dechmann, Dina K N; LaPoint, Scott; Dullin, Christian; Hertel, Moritz; Taylor, Jan R E; Zub, Karol; Wikelski, Martin

2017-02-13

Ontogenetic changes in skull shape and size are ubiquitous in altricial vertebrates, but typically unidirectional and minimal in full-grown animals. Red-toothed shrews exhibit a rare exception, where the shape, mass and size of the skull, brain, and several major organs, show significant bidirectional seasonal changes. We now show a similar but male-biased shrinking (16%) and regrowth (8%) in the standardized braincase depth of least weasels (Mustela nivalis). Juvenile weasels also exhibit a growth overshoot, followed by a shrinkage period lasting until the end of their first winter. Only male weasels then regrow during their second summer. High-resolution CT scans suggest areas of the skull are affected differently during shrinking and regrowth in both species. This suggests multiple evolutionary drivers: while the shrinking likely facilitates survival during seasonal low resource availability in these high-metabolic mammals with year-round activity, the regrowth may be most strongly influenced by high investment into reproduction and territories, which is male-biased in the weasels. Our data provide evidence for convergent evolution of skull and thus brain shrinkage and regrowth, with important implications for understanding adaptations to changing environments and for applied research on the correlated changes in bone structure, brain size and the many other affected organs.

Age estimation by pulp/tooth ratio in lower premolars by orthopantomography.

PubMed

Cameriere, Roberto; De Luca, Stefano; Alemán, Inmaculada; Ferrante, Luigi; Cingolani, Mariano

2012-01-10

Accurate age estimation has always been a problem for forensic scientists, and apposition of secondary dentine is often used as an indicator of age. Since 2004, in order to examine patterns of secondary dentine apposition, Cameriere et al. have been extensively studying the pulp/tooth area ratio of the canines by panoramic and peri-apical X-ray images. The main aim of this paper is to examine the relationship between age and age-related changes in the pulp/tooth area ratio in monoradicular teeth, with the exception of canines, by orthopantomography. A total of 606 orthopantomograms of Spanish white Caucasian patients (289 women and 317 men), aged between 18 and 75 years and coming from Bilbao and Granada (Spain), was analysed. Regression analysis of age of monoradicular teeth indicated that the lower premolars were the most closely correlated with age. An ANCOVA did not show significant differences between men and women. Multiple regression analysis, with age as dependent variable and pulp/tooth area ratio as predictor, yielded several formulae. R(2) ranged from 0.69 to 0.75 for a single lower premolar tooth and from 0.79 to 0.86 for multiple lower premolar teeth. Depending on the available number of premolar teeth, the mean of the absolute values of residual standard error, at 95% confidence interval, ranged between 4.34 and 6.02 years, showing that the pulp/tooth area ratio is a useful variable for assessing age with reasonable accuracy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Social stress in tree shrews as an animal model of depression: an example of a behavioral model of a CNS disorder.

PubMed

Fuchs, Eberhard

2005-03-01

Animal models are invaluable in preclinical research on human psychopathology. Valid animal models to study the pathophysiology of depression and specific biological and behavioral responses to antidepressant drug treatments are of prime interest. In order to improve our knowledge of the causal mechanisms of stress-related disorders such as depression, we need animal models that mirror the situation seen in patients. One promising model is the chronic psychosocial stress paradigm in male tree shrews. Coexistence of two males in visual and olfactory contact leads to a stable dominant/subordinate relationship, with the subordinates showing obvious changes in behavioral, neuroendocrine, and central nervous activity that are similar to the signs and symptoms observed during episodes of depression in patients. To discover whether this model, besides its "face validity" for depression, also has "predictive validity," we treated subordinate animals with the tricyclic antidepressant clomipramine and found a time-dependent recovery of both endocrine function and normal behavior. In contrast, the anxiolytic diazepam was ineffective. Chronic psychosocial stress in male tree shrews significantly decreased hippocampal volume and the proliferation rate of the granule precursor cells in the dentate gyrus. These stress-induced changes can be prevented by treating the animals with clomipramine, tianeptine, or the selective neurokinin receptor antagonist L-760,735. In addition to its apparent face and predictive validity, the tree shrew model also has a "molecular validity" due to the degradation routes of psychotropic compounds and gene sequences of receptors are very similar to those in humans. Although further research is required to validate this model fully, it provides an adequate and interesting non-rodent experimental paradigm for preclinical research on depression.

Posture does not matter! Paw usage and grasping paw preference in a small-bodied rooting quadrupedal mammal.

PubMed

Joly, Marine; Scheumann, Marina; Zimmermann, Elke

2012-01-01

Recent results in birds, marsupials, rodents and nonhuman primates suggest that phylogeny and ecological factors such as body size, diet and postural habit of a species influence limb usage and the direction and strength of limb laterality. To examine to which extent these findings can be generalised to small-bodied rooting quadrupedal mammals, we studied trees shrews (Tupaia belangeri). We established a behavioural test battery for examining paw usage comparable to small-bodied primates and tested 36 Tupaia belangeri. We studied paw usage in a natural foraging situation (simple food grasping task) and measured the influence of varying postural demands (triped, biped, cling, sit) on paw preferences by applying a forced-food grasping task similar to other small-bodied primates. Our findings suggest that rooting tree shrews prefer mouth over paw usage to catch food in a natural foraging situation. Moreover, we demonstrated that despite differences in postural demand, tree shrews show a strong and consistent individual paw preference for grasping across different tasks, but no paw preference at a population level. Tree shrews showed less paw usage than small-bodied quadrupedal and arboreal primates, but the same paw preference. Our results confirm that individual paw preferences remain constant irrespective of postural demand in some small-bodied quadrupedal non primate and primate mammals which do not require fine motoric control for manipulating food items. Our findings suggest that the lack of paw/hand preference for grasping food at a population level is a universal pattern among those species and that the influence of postural demand on manual lateralisation in quadrupeds may have evolved in large-bodied species specialised in fine manipulations of food items.

Effect of cannabinoids on lithium-induced vomiting in the Suncus murinus (house musk shrew).

PubMed

Parker, Linda A; Kwiatkowska, Magdalena; Burton, Page; Mechoulam, Raphael

2004-01-01

Marijuana has been reported to interfere with nausea and vomiting in chemotherapy patients. The principal cannabinoids found in marijuana include the psychoactive compound Delta-9-tetrahydrocannabinol (THC) and the non-psychoactive compound cannabidiol (CBD). The experiments reported here evaluated the potential of THC and CBD to interfere with vomiting in the Suncus murinus (house musk shrew) produced by lithium chloride (LiCl), which is the most commonly employed unconditioned stimulus for taste avoidance. To evaluate the potential of the principal components of marijuana, THC and CBD, to suppress Li-induced vomiting in the house musk shrew. Shrews were injected with vehicle or one of two cannabinoids [Delta-9-THC (1-20 mg/kg), or CBD (2.5-40 mg/kg)] 10 min prior to an injection of LiCl (390 mg/kg of 0.15 M) and were then observed for 45 min. The frequency of vomiting episodes and the latency to the first episode were measured. The role of the CB1 receptor in these effects was also evaluated by pretreatment with SR-141716. Delta-9-THC produced a dose-dependent suppression of Li-induced vomiting, with higher doses producing greater suppression than lower doses. CBD produced a biphasic effect with lower doses producing suppression and higher doses producing enhancement of Li-induced vomiting. The suppression of Li-induced vomiting by THC, but not by CBD, was reversed by SR-141716. These results indicate that two major cannabinoid compounds found in marijuana, THC and CBD, are effective treatments for Li-induced vomiting; however, only THC acts by the CB1 receptor. The effects of THC and CBD on vomiting were dose dependent; with THC the effect was linear, but with CBD the effect was biphasic.

Douglas-fir forests in the Cascade Mountains of Oregon and Washington: is the abundance of small mammals related to stand age and moisture?

USGS Publications Warehouse

Coen, P.S.; Bury, R.B.; Spies, T.A.

1988-01-01

Red tree voles (Arborimus longicaudus) were the only small mammal strongly associated with old-growth forests, whereas vagrant shrews (Sorex vagrans) were most abundant in young forests. Pacific marsh shrews (S. bendirii) were most abundant in wet old-growth forests, but abundance of this species in young (wet) forests needs further study. Clearcuts had a mammalian fauna distinct from young forest stands. Abundance of several species was correlated to habitat features unique to naturally regenerated forests, indicated an urgent need to study the long-term effects of forest management to nongame wildlife.

[Life cycle of Maupasina weissi Seurat, 1913, Subuluroidea Nematode, parasite of the elephant shrew (author's transl)].

PubMed

Quentin, J C; Verdier, J M

1979-01-01

The life cycle of Maupasina weissi Seurat, 1913, the parasite of the elephant shrew, has been experimentally obtained from the intermediate host Locusta migratoria. The biology of this Nematoda is considered as being more primitive than the Subuluridae: -- egg maturation in external environment is in fact necessary to the Maupasina larvae to penetrate into the insect, -- The different localizations of the infective larvae, such as mesenteron regeneration crypta, fat body, demonstrate that the parasite is not completely adaptated to its intermediate host, -- the ontogenesis of cephalic structures is characterized by an hypertrophy of the archaic structures mainly from cuticular origin.

Declining ecosystem health and the dilution effect.

PubMed

Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Magnusson, Magnus; Hörnfeldt, Birger

2016-08-08

The "dilution effect" implies that where species vary in susceptibility to infection by a pathogen, higher diversity often leads to lower infection prevalence in hosts. For directly transmitted pathogens, non-host species may "dilute" infection directly (1) and indirectly (2). Competitors and predators may (1) alter host behavior to reduce pathogen transmission or (2) reduce host density. In a well-studied system, we tested the dilution of the zoonotic Puumala hantavirus (PUUV) in bank voles (Myodes glareolus) by two competitors and a predator. Our study was based on long-term PUUV infection data (2003-2013) in northern Sweden. The field vole (Microtus agrestis) and the common shrew (Sorex araneus) are bank vole competitors and Tengmalm's owl (Aegolius funereus) is a main predator of bank voles. Infection probability in bank voles decreased when common shrew density increased, suggesting that common shrews reduced PUUV transmission. Field voles suppressed bank vole density in meadows and clear-cuts and indirectly diluted PUUV infection. Further, Tengmalm's owl decline in 1980-2013 may have contributed to higher PUUV infection rates in bank voles in 2003-2013 compared to 1979-1986. Our study provides further evidence for dilution effect and suggests that owls may have an important role in reducing disease risk.

Angioarchitecture of the coeliac sympathetic ganglion complex in the common tree shrew (Tupaia glis)

PubMed Central

PROMWIKORN, WARAPORN; THONGPILA, SAKPORN; PRADIDARCHEEP, WISUIT; MINGSAKUL, THAWORN; CHUNHABUNDIT, PANJIT; SOMANA, REON

1998-01-01

The angioarchitecture of the coeliac sympathetic ganglion complex (CGC) of the common tree shrew (Tupaia glis) was studied by the vascular corrosion cast technique in conjunction with scanning electron microscopy. The CGC of the tree shrew was found to be a highly vascularised organ. It normally received arterial blood supply from branches of the inferior phrenic, superior suprarenal and inferior suprarenal arteries and of the abdominal aorta. In some animals, its blood supply was also derived from branches of the middle suprarenal arteries, coeliac artery, superior mesenteric artery and lumbar arteries. These arteries penetrated the ganglion at variable points and in slightly different patterns. They gave off peripheral branches to form a subcapsular capillary plexus while their main trunks traversed deeply into the inner part before branching into the densely packed intraganglionic capillary networks. The capillaries merged to form venules before draining into collecting veins at the peripheral region of the ganglion complex. Finally, the veins coursed to the dorsal aspect of the ganglion to drain into the renal and inferior phrenic veins and the inferior vena cava. The capillaries on the coeliac ganglion complex do not possess fenestrations. PMID:9877296

Molecular, serological and epidemiological observations after a suspected outbreak of plague in Nyimba, eastern Zambia.

PubMed

Nyirenda, Stanley S; Hang'ombe, Bernard M; Kilonzo, Bukheti S; Kabeta, Mathews N; Cornellius, Mundia; Sinkala, Yona

2017-01-01

Plague is a re-emerging zoonotic disease caused by the bacterium Yersinia pestis. The disease has caused periodic global devastation since the first outbreak in the 6th century. Two months after a suspected plague outbreak in Nyimba district, samples were collected from 94 livestock (goats and pigs), 25 rodents, 6 shrews and 33 fleas. Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques were used to investigate the presence of Y. pestis, which showed that 16.0% (4/25) of rodents, 16.7% (1/6) of shrews (Crocidura spp) and 6.0% (5/83) of goats were positive for IgG antibodies against Fraction 1 antigen of Y. pestis. Plasminogen activator (Pla) gene (DNA) of Y. pestis was detected in five pools containing 36.4% (12/33) fleas collected from pigs (n = 4), goats (n = 5) and rodents (n = 3). The detection of Pla gene in fleas and IgG antibodies against Fraction1 antigen in rodents, shrews and goats suggest that Y. pestis had been present in the study area in the recent past. © The Author(s) 2016.

Serological and PCR investigation of Yersinia pestis in potential reservoir hosts from a plague outbreak focus in Zambia.

PubMed

Nyirenda, S S; Hang'ombe, B M; Mulenga, E; Kilonzo, B S

2017-07-28

Plague is a bacterial zoonotic disease, caused by Yersinia pestis. Rodents are the natural hosts with fleas as the vehicle of disease transmission. Domestic and wild dogs and cats have also been identified as possible disease hosts. In Zambia, plague outbreaks have been reported in the Southern and Eastern regions in the last 20 years. Based on these observations, Y. pestis could possibly be endemically present in the area. To substantiate such possibility, sera samples were collected from rodents, shrews, dogs and cats for detection of antibodies against Fraction 1 gene (Fra1) of Y. pestis while organs from rodents and shrews, and fleas from both dogs and rodents were collected to investigate plasminogen activator gene (pla gene) of Y. pestis using ELISA and PCR respectively. A total of 369 blood samples were collected from domestic carnivores, shrews and domestic and peri-domestic rodents while 199 organs were collected from the rodents and shrews. Blood samples were tested for antibodies against Fra1 antigen using ELISA and 3% (5/165) (95% CI 0.99-6.93%) dogs were positive while all cats were negative. Of 199 sera from rodents and shrews, 12.6% (95% CI 8.30-17.98%) were positive for antibodies against Fra1 using anti-rat IgG secondary antibody while using anti-mouse IgG secondary antibody, 17.6% (95% CI 12.57-23.60%) were positive. PCR was run on the organs and 2.5% (95% CI 0.82-5.77%) were positive for plasminogen activator gene of Y. pestis and the amplicons were sequenced and showed 99% identity with Y. pestis reference sequences. All 82 fleas collected from animals subjected to PCR, were negative for pla gene. The specific rat-flea and dog-flea indices were 0.19 and 0.27 respectively, which were lower than the level required to enhance chances of the disease outbreak. We concluded that plague was still endemic in the area and the disease may infect human beings if contact is enhanced between reservoir hosts and flea vectors. The lower specific rodent-flea Indices and absence of Y. pestis in the potential vectors were considered to be partly responsible for the current absence of plague outbreaks despite its presence in the sylvatic cycle.

Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching

PubMed Central

Ghanbarzadeh, Majid; Akbari, Majid; Hamzei, Haniye

2015-01-01

Background There is little data regarding the effect of tooth whitening on microhardness of white spot lesions. This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel. Material and Methods Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both groups. Results Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (p<0.05). There were no significant differences in hardness values among the two groups either before (p=0.131) or after (p=0.182) the bleaching procedures. Conclusions Tooth whitening through home bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on bleached demineralized enamel. Key words:White spot lesion, bleaching, laser, microhardness, demineralized enamel, home bleaching, in-office bleaching. PMID:26330939

Evaluation of a 6% hydrogen peroxide tooth-whitening gel on enamel microhardness after extended use.

PubMed

Toteda, Mariarosaria; Philpotts, Carole J; Cox, Trevor F; Joiner, Andrew

2008-11-01

To evaluate the effects of a 6% hydrogen peroxide tooth whitener, Xtra White, on sound human enamel microhardness in vitro after an extended and exaggerated simulated 8 weeks of product use. Polished human enamel specimens were prepared and baseline microhardness and color measurements determined. The enamel specimens were exposed to a fluoride-containing toothpaste for 30 seconds and then exposed to water, Xtra White, a control carbopol gel containing no hydrogen peroxide, or a carbonated beverage (each group, n = 8) for 20 minutes. Specimens were exposed to whole saliva at all other times. In order to simulate 8 weeks of extended product use, quadruple the length of the manufacturer's instructions, 112 treatments, were conducted. Microhardness measurements were taken after 2, 4, 6, and 8 weeks of simulated treatments, and color was measured after 2 and 8 weeks. The Xtra White-treated specimens showed a statistically significant (P < .0001) increase in L* and decrease in b* compared to the water-treated specimens after 2 weeks simulated use, indicating bleaching had occurred. The carbonated beverage-treated specimens were significantly softened (P = .0009) compared to baseline after only 1 treatment. The carbopol gel-treated specimens were significantly softened (P = .0028) after 2 weeks of simulated treatments compared to baseline. There were no statistically significant differences in enamel microhardness between baseline and all treatment times for XW and water groups. Xtra White does not have any deleterious effects on sound human enamel microhardness after an extended and exaggerated simulated 8 weeks of product use.

Mechanics of biting in great white and sandtiger sharks.

PubMed

Ferrara, T L; Clausen, P; Huber, D R; McHenry, C R; Peddemors, V; Wroe, S

2011-02-03

Although a strong correlation between jaw mechanics and prey selection has been demonstrated in bony fishes (Osteichthyes), how jaw mechanics influence feeding performance in cartilaginous fishes (Chondrichthyes) remains unknown. Hence, tooth shape has been regarded as a primary predictor of feeding behavior in sharks. Here we apply Finite Element Analysis (FEA) to examine form and function in the jaws of two threatened shark species, the great white (Carcharodon carcharias) and the sandtiger (Carcharias taurus). These species possess characteristic tooth shapes believed to reflect dietary preferences. We show that the jaws of sandtigers and great whites are adapted for rapid closure and generation of maximum bite force, respectively, and that these functional differences are consistent with diet and dentition. Our results suggest that in both taxa, insertion of jaw adductor muscles on a central tendon functions to straighten and sustain muscle fibers to nearly orthogonal insertion angles as the mouth opens. We argue that this jaw muscle arrangement allows high bite forces to be maintained across a wider range of gape angles than observed in mammalian models. Finally, our data suggest that the jaws of sub-adult great whites are mechanically vulnerable when handling large prey. In addition to ontogenetic changes in dentition, further mineralization of the jaws may be required to effectively feed on marine mammals. Our study is the first comparative FEA of the jaws for any fish species. Results highlight the potential of FEA for testing previously intractable questions regarding feeding mechanisms in sharks and other vertebrates. Copyright © 2010 Elsevier Ltd. All rights reserved.

Allometric relationships of the dentition of the great White Shark, Carcharodon carcharias, in forensic investigations of shark attacks.

PubMed

Nambiar, P; Bridges, T E; Brown, K A

1991-06-01

As a result of a systematic morphometric study of shark dentitions, a system of notation for describing the location of shark teeth has been developed and is proposed as a standard to be adopted for use in similar studies in the future. The macroscopic morphology of White Shark teeth has been characterised in order to gain quantitative data which might assist in identification of these sharks from bite marks on victims or objects or from shark carcasses. Using these data, a nomogram has been developed which can be used to estimate the body length of a White Shark from measurements of tooth or bite mark morphology. An example of the forensic application of such allometric data is provided as it applied to a recent fatal attack on a diver by a White Shark.

Current technology and techniques in re-mineralization of white spot lesions: A systematic review

NASA Astrophysics Data System (ADS)

Podray, Susan S.

White Spot lesions are a common iatrogenic occurrence on patients who are treated with fixed orthodontic appliances. There is a dynamic chemical interaction between enamel and saliva at the tooth surface that allow a lesion to have phase changes involving demineralization of enamel and reminerlization. This is due to calcium and phosphate dissolved in saliva that is deposited onto the tooth surface or removed depending on the surrounding pH. Caseinphosphopeptide-amorphous calcium phosphate (CPP-ACP) is gaining popularity in dentistry as a way to increase the available level of calcium and phosphate in plaque and saliva to improve the chemical gradient so that if favors reminerlization. The aim of our investigation is to search the available current literature and formulate a recommendation for use of CPP-ACP in orthodontics. Publications from the following electronic databases were searched: PubMed, Web of Science, Cochrane Library and Science Direct. Searches from August 2010 to April 1st 2012 were performed under the terms "MI Paste OR Recaldent OR caseinphosphopeptide-amorphous calcium phosphate OR CPP-ACP or tooth mousse". The searches yielded 155 articles, These were reviewed for relevance based on inclusion and exclusion criteria. Articles with inappropriate study design or no outcome measures at both baseline and end point were also excluded. 13 articles were deemed of relevance with a high quality study design and were included in this study for evaluation. The current literature suggests a preventative treatment regimen in which MI Paste Plus is used. It should be delivered once daily prior to bed after oral hygiene for 3 minutes in a fluoride tray, throughout orthodontic treatment. It should be recommended for high risk patients determined by poor oral hygiene, as seen by the inability to remove plaque from teeth and appliances. This protocol may prevent or assist in the remineralization of enamel white spot lesions during and after orthodontic treatment.

UTILIZATION OF THE LEAST SHREW AS A RAPID AND SELECTIVE SCREENING MODEL FOR THE ANTIEMETIC POTENTIAL AND BRAIN PENETRATION OF SUBSTANCE P AND NK1 RECEPTOR ANTAGONISTS

PubMed Central

Darmani, Nissar A.; Wang, Yaozhi; Abad, Joseph; Ray, Andrew P.; Thrush, Gerald R.; Ramirez, Juan

2008-01-01

Substance P (SP) is thought to play a cardinal role in emesis via the activation of central tachykinin NK1 receptors during the delayed phase of vomiting produced by chemotherapeutics. Although the existing supportive evidence is significant, due to lack of an appropriate animal model, the evidence is indirect. As yet, no study has confirmed that emesis produced by SP or a selective NK1 receptor agonist is sensitive to brain penetrating antagonists of either NK1, NK2, or NK3 receptors. The goals of this investigation were to demonstrate: 1) whether intraperitoneal (i.p.) administration of either SP, a brain penetrating (GR73632) or non-penetrating (e.g. SarMet – SP) NK1 receptor agonist, an NK2 receptor agonist (GR64349), or an NK3 receptor agonist (Pro7-NKB), would induce vomiting and/or scratching in the least shrew (Cryptotis parva) in a dose-dependent manner; and whether these effects are sensitive to the above selective receptor antagonists; 2) whether an exogenous emetic dose of SP (50 mg/kg, i.p.) can penetrate into the shrew brain stem and frontal cortex; 3) whether GR73632 (2.5 mg/kg, i.p.)-induced activation of NK1 receptors increases Fos-measured neuronal activity in the neurons of both brain stem emetic nuclei and the enteric nervous system of the gut; and 4) whether selective ablation of peripheral NK1 receptors can affect emesis produced by GR73632. The results clearly demonstrated that while SP produced vomiting only, GR73632 caused both emesis and scratching behavior dose-dependently in shrews, and these effects were sensitive to NK1-, but not NK2- or NK3-receptor antagonists. Neither the selective, non-penetrating NK1 receptor agonists, nor the selective NK2- or NK3-receptor agonists, caused a significant dose-dependent behavioral effect. An emetic dose of SP selectively and rapidly penetrated the brain stem but not the frontal cortex. Systemic GR73632 increased Fos expression in the enteric nerve plexi, the medial subnucleus of nucleus tractus solitarius, and the dorsal motor nucleus of the vagus, but not the area postrema. Ablation of peripheral NK1 receptors attenuated the ability of GR73632 to induce a maximal frequency of emesis and shifted its percent animals vomiting dose-response curve to the right. The NK1-ablated shrews exhibited scratching behavior after systemic GR73632-injection. These results, for the first time, affirm a cardinal role for central NK1 receptors in SP-induced vomiting, and a facilitatory role for gastrointestinal NK1 receptors. In addition, these data support the validation of the least shrew as a specific and rapid behavioral animal model to screen concomitantly both the CNS penetration and the antiemetic potential of tachykinin NK1 receptor antagonists. PMID:18471804

Small mammal community composition in cornfields, roadside ditches, and prairies in eastern Nebraska

USGS Publications Warehouse

Kirsch, E.M.

1997-01-01

Community composition of small mammals was examined in prairies, cornfields, and their adjacent roadside ditches in eastern Nebraska. Western harvest mice (Reithrodontomys megalotis) and meadow voles (Microtus pennsylvanicus) were associated with prairie habitat, were common in ditches, but avoided cornfields. Prairie voles (M. Ochrogaster) and white-footed mice (Peromyscus leucopus) were associated with ditch habitat, were common in prairies, but avoided cornfields. Short-tailed shrews (Blarina brevicauda) avoided cornfields, were associated with ditches next to cornfields, but were common in prairies and ditches next to prairies. Deer mice (P. Maniculatus) were associated with cornfields but were relatively common in prairies and ditches. House mice (Mus musculus) were most common in ditches next to cornfields, occurred in cornfields and ditches next to prairies, but were not captured in prairies. Although community composition appears to differ among prairies, ditches, and cornfields, ditches support a more complete suite of the native small mammal species in large and relatively even numbers, whereas cornfields only support deer mice in large numbers.

Achieving a precise color chart with common computer software for excellence in anterior composite restorations.

PubMed

Salat, Anna; Devoto, Walter; Manauta, Jordi

2011-01-01

Achieving similar features to those on natural teeth is a common problem with esthetic restorations. Color matching is a fundamental procedure required to perform a predictable composite resin restoration. It is no longer enough to measure these criteria with conventional shade guides, which provide the hue and chroma, but do not take into account other dimensions of the tooth such as value, intensives, opalescence and characterizations. The present article presents a simple and effective technique for color selection using a digital photograph of the tooth and an image-editing program such as Adobe Photoshop or Picture Project. The digital editing of the photograph with two simple steps described in this paper reveals the internal structures of the tooth easily. The modified photographs highlight the opalescence, white spots, shape of the internal mammelons and other features that are not visible at first glance. This procedure provides an accurate color chart with which the clinician can begin an esthetic restoration process.

Ecotoxicological damage from zinc smelting at Palmerton, Pennsylvania

USGS Publications Warehouse

Beyer, W. Nelson; Storm, Gerald L.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

1995-01-01

The two zinc smelters at Palmerton, PA emitted huge amounts of contaminants ( 260,000 t of Zn, 3,300 t of Cd, 6,800 t of Pb) to the air and severely damaged the forest on Blue Mountain. The high Zn concentrations in soil killed tree seedlings by inhibiting root elongation. The result was a forest with too few young trees. When natural stresses such as fire challenged the forest, the forest failed to regenerate, and the exposed soil eroded down the steep slopes. Tree species that could sprout were favored over those that developed from seeds. As a result of high zinc concentrations, the lichen and moss communities were depauperate for at least 20 km along Blue Mountain. The denuded areas are in the process of being reclaimed with the addition of a mixture of fly ash and sewage sludge, which is seeded with grasses tolerant to the harsh conditions. In preliminary experiments, the fly ash and sewage sludge mixture was stable, despite the steepness of the slopes of the reclaimed sites on Blue Mountain. Zinc emissions reduced the decomposition rate of plant material on Blue Mountain. The partially decomposed litter, in particular, accumulated on the surface of the mineral soil. The populations of both microorganisms and arthropods were greatly reduced in soils near the smelters. Samples of litter collected from sites spanning 30 km were toxic to woodlice, and Zn was shown to be the toxic factor. A white-tailed deer examined had a very high renal Zn concentration and an articular lesion in one of its hind legs that closely resembled the lesions reported in Zn-poisoned horses. Zinc concentrations were regulated in wildlife tissues and were not reliable indicators of exposure, except in extreme cases. Two songbirds, a shrew, and several rabbits contained Pb concentrations that were suggested to be toxic. Shrews and ground-feeding songbirds accumulated relatively high concentrations of Pb. Exposure to Pb seemed to be related to the amount of soil that an animal ingests. Some white-tailed deer and cottontails had renal Cd concentrations near 600 ppm w.w., which is associated with renal damage in other mammals. The accumulation of Cd was greatest in wildlife that lived longest. The destruction of the habitat for wildlife on Blue Mountain decreased wildlife populations. Populations of insectivorous birds, however, were depressed well beyond the area of obvious damage to the forest. Forest-floor salamanders were completely absent from study sites spanning 18 km along Blue Mountain. Actual reductions in wildlife populations were much greater than would have been predicted from habitat suitability models alone.

Functional skeletal morphology and its implications for locomotory behavior among three genera of myosoricine shrews (Mammalia: Eulipotyphla: Soricidae)

USGS Publications Warehouse

Woodman, Neal; Stabile, Frank A.

2015-01-01

Myosoricinae is a small clade of shrews (Mammalia, Eulipotyphla, Soricidae) that is currently restricted to the African continent. Individual species have limited distributions that are often associated with higher elevations. Although the majority of species in the subfamily are considered ambulatory in their locomotory behavior, species of the myosoricine genus Surdisorex are known to be semifossorial. To better characterize variation in locomotory behaviors among myosoricines, we calculated 32 morphological indices from skeletal measurements from nine species representing all three genera that comprise the subfamily (i.e., Congosorex, Myosorex, Surdisorex) and compared them to indices calculated for two species with well-documented locomotory behaviors: the ambulatory talpid Uropsilus soricipes and the semifossorial talpid Neurotrichus gibbsii. We summarized the 22 most complete morphological variables by 1) calculating a mean percentile rank for each species and 2) using the first principal component from principal component analysis of the indices. The two methods yielded similar results and indicate grades of adaptations reflecting a range of potential locomotory behaviors from ambulatory to semifossorial that exceeds the range represented by the two talpids. Morphological variation reflecting grades of increased semifossoriality among myosoricine shrews is similar in many respects to that seen for soricines, but some features are unique to the Myosoricinae.

Discovery of hantaviruses in bats and insectivores and the evolution of the genus Hantavirus.

PubMed

Zhang, Yong-Zhen

2014-07-17

Hantaviruses are among the most important zoonotic pathogens of humans, causing either hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). From the period 1964-2006 almost all hantaviruses had been identified in rodents, with the exception of Thottapalayam virus (TPMV) isolated from shrews sampled in India. As a consequence, rodents were considered as the natural reservoir hosts. However, over the past seven years, most of the newly found hantavirus genotypes have been from either shrews or moles. Remarkably, in recent years divergent hantaviruses have also been identified in bats sampled from both Africa and Asia. All these data indicate that hantaviruses have a broad range of natural reservoir hosts. Phylogenetic analyses of the available sequences of hantaviruses suggest that hantaviruses might have first appeared in Chiroptera (bats) or Soricomorpha (moles and shrews), before emerging in rodent species. Although rodent hantaviruses cluster according to whether their hosts are members of the Murinae and Cricetidae, the phylogenetic histories of the viruses are not always congruent with those of their hosts, indicating that cross-species transmission events have occurred at all taxonomic levels. In sum, both cross-species transmission and co-divergence have produced the high genetic diversity of hantaviruses described to date. Copyright © 2014. Published by Elsevier B.V.

Rediscovery of the type series of the Acadian Masked Shrew, Sorex acadicus Gilpin, 1865 (Mammalia: Soricidae), with the designation of a neotype and a reevaluation of its taxonomic status

USGS Publications Warehouse

Woodman, Neal

2018-01-01

The name Sorex acadicus Gilpin, 1865 is currently recognized as the valid name for the Nova Scotian subspecies of the masked shrew, S. cinereus Kerr, 1792 (Mammalia: Soricidae), but a holotype for the taxon was never designated, and the location of the type series has been a mystery. The authority for this species, John Bernard Gilpin, was associated with the Nova Scotia Museum, Halifax, NS, but that institution has no Gilpin specimens in its possession, and I could find no record of Gilpin shrews in any other Canadian Museum. I recently discovered a series of Gilpin specimens in the Mammal Collection of the National Museum of Natural History, Washington, DC (USNM), some of which may have been part of the original type series of S. acadicus, and I show that these specimens best represent Gilpin's concept of the taxon. From this series, I designate a neotype for S. acadicus. I also evaluate the distinctiveness of Nova Scotian S. c. acadicus compared with S. c. cinereus from Maine, New Brunswick, and New Hampshire and determine that S. acadicus should be considered a junior synonym of S. c. cinereus.

Fine structure of the uteri in two hymenolepidid tapeworm Skrjabinacanthus diplocoronatus and Urocystis prolifer (Cestoda: Cyclophyllidea) parasitic in shrews that display different fecundity of the strobilae.

PubMed

Korneva, Janetta V; Kornienko, Svetlana A; Jones, Malcolm K

2012-10-01

Adult specimens of Skrjabinacanthus diplocoronatus and Urocystis prolifer were investigated by light and transmission electron microscopy, and data on the uterine organization in these species are presented. The interrelationships of morphological changes of the uterus and developing eggs on the one hand with fecundities of the strobilae of cyclophyllidean cestodes on the other hand are investigated. The development of the excretory system forming a network of excretory ducts close to the uterus is characteristic of S. diplocoronatus. Numerous excretory ducts are located near the uterus or contact the uterine epithelium and are also found in uterine cords. Accumulation of lipids is observed in the cavity of excretory ducts, in muscular cells, and in the lumen of the uterus as well as in the developing eggs. This species displays the largest fecundity among cestode parasites of the shrew. U. prolifer has one of the lowest fecundities among cestodes from shrews. A small amount of lipids found in cells of gravid proglottids could serve as a supply of nutrients. It seems that some cestodes with great fecundity possess specific paths by which eggs are supplied with nutrients. As a result, diverse modifications of the uterus in Cyclophyllidea are formed.

Declining ecosystem health and the dilution effect

PubMed Central

Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Magnusson, Magnus; Hörnfeldt, Birger

2016-01-01

The “dilution effect” implies that where species vary in susceptibility to infection by a pathogen, higher diversity often leads to lower infection prevalence in hosts. For directly transmitted pathogens, non-host species may “dilute” infection directly (1) and indirectly (2). Competitors and predators may (1) alter host behavior to reduce pathogen transmission or (2) reduce host density. In a well-studied system, we tested the dilution of the zoonotic Puumala hantavirus (PUUV) in bank voles (Myodes glareolus) by two competitors and a predator. Our study was based on long-term PUUV infection data (2003–2013) in northern Sweden. The field vole (Microtus agrestis) and the common shrew (Sorex araneus) are bank vole competitors and Tengmalm’s owl (Aegolius funereus) is a main predator of bank voles. Infection probability in bank voles decreased when common shrew density increased, suggesting that common shrews reduced PUUV transmission. Field voles suppressed bank vole density in meadows and clear-cuts and indirectly diluted PUUV infection. Further, Tengmalm’s owl decline in 1980–2013 may have contributed to higher PUUV infection rates in bank voles in 2003–2013 compared to 1979–1986. Our study provides further evidence for dilution effect and suggests that owls may have an important role in reducing disease risk. PMID:27499001

Measuring airborne components of seismic body vibrations in a Middle-Asian sand-dwelling Insectivora species, the piebald shrew (Diplomesodon pulchellum).

PubMed

Volodin, Ilya A; Zaytseva, Alexandra S; Ilchenko, Olga G; Volodina, Elena V; Chebotareva, Anastasia L

2012-08-15

Self-produced seismic vibrations have been found for some subterranean rodents but have not been reported for any Insectivora species, although seismic sensitivity has been confirmed for blind sand-dwelling chrysochlorid golden moles. Studying the vocal behaviour of captive piebald shrews, Diplomesodon pulchellum, we documented vibrations, apparently generated by the whole-body wall muscles, from 11 (5 male, 6 female) of 19 animals, placed singly on a drum membrane. The airborne waves of the vibratory drumming were digitally recorded and then analysed spectrographically. The mean frequency of vibration was 160.5 Hz. This frequency matched the periodicity of the deep sinusoidal frequency modulation (159.4 Hz) found in loud screech calls of the same subjects. The body vibration was not related to thermoregulation, hunger-related depletion of energy resources or fear, as it was produced by well-fed, calm animals, at warm ambient temperatures. We hypothesize that in the solitary, nocturnal, digging desert piebald shrew, body vibrations may be used for seismic exploration of substrate density, to avoid energy-costly digging of packed sand for burrowing and foraging. At the same time, the piercing quality of screech calls due to the deep sinusoidal frequency modulation, matching the periodicity of body vibration, may be important for agonistic communication in this species.

Long-wavelength (red) light produces hyperopia in juvenile and adolescent tree shrews.

PubMed

Gawne, Timothy J; Ward, Alexander H; Norton, Thomas T

2017-11-01

In infant tree shrews, exposure to narrow-band long-wavelength (red) light, that stimulates long-wavelength sensitive cones almost exclusively, slows axial elongation and produces hyperopia. We asked if red light produces hyperopia in juvenile and adolescent animals, ages when plus lenses are ineffective. Animals were raised in fluorescent colony lighting (100-300 lux) until they began 13days of red-light treatment at 11 (n=5, "infant"), 35 (n=5, "juvenile") or 95 (n=5, "adolescent") days of visual experience (DVE). LEDs provided 527-749 lux on the cage floor. To control for the higher red illuminance, a fluorescent control group (n=5) of juvenile (35 DVE) animals was exposed to ∼975 lux. Refractions were measured daily; ocular component dimensions at the start and end of treatment and end of recovery in colony lighting. These groups were compared with normals (n=7). In red light, the refractive state of both juvenile and adolescent animals became significantly (P<0.05) hyperopic: juvenile 3.9±1.0 diopters (D, mean±SEM) vs. normal 0.8±0.1D; adolescent 1.6±0.2D vs. normal 0.4±0.1D. The fluorescent control group refractions (0.6±0.3D) were normal. In red-treated juveniles the vitreous chamber was significantly smaller than normal (P<0.05): juvenile 2.67±0.03mmvs. normal 2.75±0.02mm. The choroid was also significantly thicker: juvenile 77±4μmvs. normal 57±3μm (P<0.05). Although plus lenses do not restrain eye growth in juvenile tree shrews, the red light-induced slowed growth and hyperopia in juvenile and adolescent tree shrews demonstrates that the emmetropization mechanism is still capable of restraining eye growth at these ages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Life cycle of Renylaima capensis, a brachylaimid trematode of shrews and slugs in South Africa: two-host and three-host transmission modalities suggested by epizootiology and DNA sequencing

PubMed Central

2012-01-01

Background The life cycle of the brachylaimid trematode species Renylaima capensis, infecting the urinary system of the shrew Myosorex varius (Mammalia: Soricidae: Crocidosoricinae) in the Hottentots Holland Nature Reserve, South Africa, has been elucidated by a study of its larval stages, epizootiological data in local snails and mammals during a 34-year period, and its verification with mtDNA sequencing. Methods Parasites obtained from dissected animals were mounted in microscope slides for the parasitological study and measured according to standardized methods. The mitochondrial DNA cox1 gene was sequenced by the dideoxy chain-termination method. Results The slugs Ariostralis nebulosa and Ariopelta capensis (Gastropoda: Arionidae) act as specific first and second intermediate hosts, respectively. Branched sporocysts massively develop in A. nebulosa. Intrasporocystic mature cercariae show differentiated gonads, male terminal duct, ventral genital pore, and usually no tail, opposite to Brachylaimidae in which mature cercariae show a germinal primordium and small tail. Unencysted metacercariae, usually brevicaudate, infect the kidney of A. capensis and differ from mature cercariae by only a slightly greater size. The final microhabitats are the kidneys and ureters of the shrews, kidney pelvis and calyces in light infections and also kidney medulla and cortex in heavy infections. Sporocysts, cercariae, metacercariae and adults proved to belong to R. capensis by analysis of a 437-bp-long cox1 fragment, which was identical except for three mutations in metacercariae, of which only one silent. Epizootiological studies showed usual sporocyst infection in A. nebulosa and very rare metacercarial infection in A. capensis, which does not agree with high prevalences and intensities in the shrews. Conclusions The presence of monotesticular adult forms and larval prevalences and intensities observed suggest that R. capensis may use two transmission strategies, a two-host life cycle by predation of A. nebulosa harbouring intrasporocystic cercariae may be the normal pattern, whereas a second mollusc host is just starting to be introduced. In shrews, a tissue-traversing, intraorganic migration followed by an interorganic migration to reach and penetrate the outer surface of either of both kidneys should occur. For first slug infection, the fluke takes advantage of the phenomenon that M. varius always urinate during defaecation. Consequently, in Brachylaimidae, the second intermediate mollusc host should evolutionarily be seen as a last addition to the cycle and their present adult stage microhabitat restricted to digestive tract and related organs as a loss of the tissue-traversing capacity of the metacercaria. PMID:22889081

Differential protein expression in Tree Shrew sclera during development of lens-induced myopia and recovery

PubMed Central

Norton, Thomas T.

2007-01-01

Purpose The tree shrew model of refractive development is particularly useful because, like humans, tree shrews have a fibrous sclera. Selective changes in some candidate extracellular matrix proteins and mRNAs have been found in the sclera during the development of, and recovery from, induced myopia. We undertook a more neutral proteomic analysis using two-dimensional gel electrophoresis and mass spectrometry to identify scleral proteins that are differentially expressed during the development of, and recovery from, lens-induced myopia. Methods Five tree shrews (Tupaia glis belangeri) wore a monocular –5 D lens for 4 days, starting 24 days after natural eye opening. At the end of this time, all treated eyes had partially compensated for the lens and were –3.5±0.7 D (mean ± SEM) myopic relative to the untreated fellow control eyes. An additional five animals wore a –5 D lens for 11–13 days, followed by 4 days of recovery without the –5 D lens. The amount of recovery was 1.6±0.4 D. Scleral proteins from both groups were then isolated and resolved by two-dimensional gel electrophoresis and spots that were differentially expressed were identified by mass spectrometry. Results The scleral protein profile typically displayed ~700 distinct protein spots within the pH 5–8 range. Comparison of the treated-eye and control-eye scleras of the lens-compensation animals revealed five spots that were significantly differentially expressed in all five pairs of eyes; all were downregulated 1.2 to 1.7 fold in the treated eye. These proteins were identified as: pigment epithelium-derived factor (PEDF), procollagen I α1, procollagen I α2, and thrombospondin I (two spots). In the recovering eyes, the two thrombospondin I spots remained lower in abundance while PEDF and the procollagens were no longer downregulated. In addition, 78 kDa glucose-regulated protein (GRP 78), a member of the heat shock protein 70 family, was slightly upregulated 1.3 fold. Conclusions We found consistent results across animals that were of a magnitude consistent with the physiologically small changes to the focal plane of these eyes. Changes in collagen confirm previous findings, but downregulation of thrombospondin I adds detail to our understanding of the chain of signals that regulates scleral creep rate. The differential changes in PEDF and GRP 78 were not expected, based on previous studies, and demonstrate the utility of the proteomic approach in tree shrew sclera. PMID:17893659

BLOOD CHEMISTRY AND HEMATOLOGY VALUES IN HEALTHY AND REHABILITATED ROUGH-TOOTHED DOLPHINS ( STENO BREDANENSIS).

PubMed

Manire, Charles A; Reiber, C Melanie; Gaspar, Cécile; Rhinehart, Howard L; Byrd, Lynne; Sweeney, Jay; West, Kristi L

2018-01-01

Rehabilitation efforts for live stranded marine mammals are guided by diagnostic measures of blood chemistry and hematology parameters obtained from each individual undergoing treatment. Despite the widespread use of blood parameters, reference values are not available in the literature from healthy rough-toothed dolphins ( Steno bredanensis) with which to infer the health status of an animal. We examined serum or plasma chemistry and hematology data from 17 rough-toothed dolphins either housed at Dolphin Quest French Polynesia or during their rehabilitation at the Dolphin and Whale Hospital in Sarasota, Florida, US between 1994 and 2005. Blood parameters were compared among healthy animals, rehabilitation animals that were eventually released, and rehabilitation animals that died. This study indicated significant differences in many blood parameters for the poorly known rough-toothed dolphin that are likely to vary between healthy and sick animals. These included aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, bicarbonate, and globulins, which were greater in sick dolphins, and alkaline phosphatase and total protein which were greater in healthy individuals. Total white blood cell counts were lower in healthy animals as were the absolute numbers of neutrophils, monocytes, and eosinophils. Analysis of first blood sample levels for glucose, sodium, and erythrocyte sedimentation rate may have value for triage and prognostic evaluation.

Measurements and modelling of the influence of dentine colour and enamel on tooth colour.

PubMed

Battersby, Paul D; Battersby, Stephen J

2015-03-01

We provide a quantitative predictive model for the extent to which coloured dentine, visible through the enamel, contributes to tooth colour. Our model uses (L(*),a(*),b(*)) measurements rather than spectral measurements. We have used a model system, composed of a slice of bovine enamel placed on top of coloured paper. We have measured the colour of the enamel-paper combination, as an analogue for a tooth, and have related this to the colour of the paper, as an analogue for dentine. By changing the paper colour, we have been able to explore how the colour of dentine determines tooth colour, according to our model system. We have also compared hydrated and desiccated samples. In qualitative terms, superimposing the enamel on top of the paper increases the "lightness" for all colours tested except white while simultaneously reducing the chromaticity, a measure of the extent to which the colour differs from grey. Desiccated enamel is much more effective at increasing the lightness and reducing the chromaticity than hydrated enamel. Quantitatively, our measurements are reproduced by the mathematical model we have developed to within 2% in "lightness" and about 8% in chromaticity. We are able to predict the colour of an analogue for a tooth, composed of bovine enamel and coloured paper, from the colour of an analogue for the dentine, the coloured paper alone, with good accuracy. This understanding provides insights into the role of dentine colour in determining tooth colour. Our work helps quantify the importance of dentine colour, compared to other, extrinsic causes of colour, such as staining, in determining the visible colour of teeth. Our predicted colours represent a baseline to which extrinsic sources will add. Copyright © 2015. Published by Elsevier Ltd.

Deletion of epithelial cell-specific Cdc42 leads to enamel hypermaturation in a conditional knockout mouse model.

PubMed

Tian, Zhihui; Lv, Xiaolin; Zhang, Min; Wang, Xueer; Chen, Yinghua; Tang, Pei; Xu, Pengcheng; Zhang, Lu; Wu, Buling; Zhang, Lin

2018-04-21

Recent evidence suggests that GTPases Rho family plays an important role in tooth development; however, the role of Cdc42 in tooth development remains unclear. We aimed to investigate the function of Cdc42 in tooth development and amelogenesis. We generated an epithelial cell-specific K5-Cdc42 knockout (KO) mouse to evaluate post-eruption dental phenotypes using a K5-Cre driver line. This model overcomes the previously reported perinatal lethality. Tooth phenotypes were analyzed by micro X-ray, micro-computed tomography (CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), wear rate, shear strength, and a microhardness test. Enamel matrix protein expression was determined by immunohistochemistry. KO mice displayed a hypomaturation phenotype, including incisors that lacked yellow pigmentation and were abnormally white, rapid attrition of molars following eruption, and decreased micro-hardness and shearing strength. Micro-CT data revealed that of incisor and molar enamel volumes were smaller in the KO than in wild-type (WT) mice. SEM analysis showed that the enamel prism structure was disordered. In addition, HE staining indicated a remarkable difference in the ameloblast morphology and function between KO and WT mice, and immunohistochemistry showed increased expression of amelogenin, ameloblastin, matrix metallopeptidase 20, kallikrein-related peptidase 4 and amelotin in the KO mice teeth. Our results suggest epithelium cell-specific Cdc42 deletion leads to tooth hypomaturation and transformation of the enamel prism structure that is likely due to altered ameloblast morphology and the secretion of enamel matrix proteins and proteases. This is the first in vivo evidence suggesting that Cdc42 is essential for proper tooth development and amelogenesis. Copyright © 2018. Published by Elsevier B.V.

Caries prevention during orthodontic treatment: In-vivo assessment of high-fluoride varnish to prevent white spot lesions.

PubMed

Perrini, Federico; Lombardo, Luca; Arreghini, Angela; Medori, Silvia; Siciliani, Giuseppe

2016-02-01

Our objective was to evaluate the efficacy of a fluoridated varnish in preventing white spot lesions in patients with fixed appliances. A laser-induced fluorescence device was used to determine any correlations between the degree of demineralization and the length of the observation period, the arch sector, the frequency of varnish application, and the specific tooth site. A split-mouth study design was used for 24 orthodontic patients, allocated randomly to 2 subgroups with differing frequencies of Duraphat varnish (Colgate-Palmolive, New York, NY) application. Repeated measures of the degree of demineralization were taken on the vestibular surfaces of 12 teeth (6 varnished and 6 unvarnished controls). Measurements were taken at 4 sites using a DIAGNOdent Pen 2190 laser (KaVo, Biberach an der Riss, Germany) and then subjected to statistical analysis. Generalized linear model and coefficient model analysis showed differences in the degrees of demineralization between treated and untreated teeth, but this was not statistically significant in terms of time point, frequency of application, or specific tooth site. However, when we analyzed the position of the teeth, the varnished anterior teeth showed a statistically significant reduction in demineralization compared with their unvarnished counterparts. Periodic application of fluoride varnish can offer some protection against white spots, but not to a statistically significant degree if the patients have excellent oral hygiene. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

[Biotope distribution of cestodes from the common shrew Sorex araneus in southern Karelia].

PubMed

Anikanova, V S; Ieshko, E P; Bugmyrin, S V; Borodina, K A

2003-01-01

Specific features in the formation of cestode species composition in the common shrew in different biotopes have been analyzed. Four categories of parasites have been recognized depending on a degree of dominance: dominants (Neoskrjabinolepis singularis, Molluscotaenia crassiscolex), subdominants (Ditestolepis diaphana), adominants A (Staphylocystis furcata, Vigisolepis spinulosa, adominants B (Hymenolepis scutigera, Dilepis undula, D. secunda, Taenia mustelae). A significant similarity was discovered between the species diversity and the dominance characteristics of cestodes. It was found that the distribution of mass species of parasites in the host population corresponds to the gamma distribution model. In regard to cestodes examined, a hypothesis considering the spatial structure and size of territory occupied by stable parasitic system is put forward.

Nomenclatural notes and identification of small-eared shrews (Mammalia: genus Cryptotis) from Cobán, Guatemala, in The Natural History Museum, London

USGS Publications Warehouse

Woodman, Neal

2011-01-01

A small series of shrews collected in Guatemala and registered in the British Museum between 1843 and 1907 includes parts of type series for three species: Corsira tropicalis Gray (1843), Sorex micrurus Tomes (1862), and Blarina tropicalis Merriam (1895). These three names are now considered equivalent, but my recent review of the specimens comprising the series indicates that they include three distinct species: Cryptotis merriami Choate (1970), Cryptotis oreoryctes Woodman (2011), and Cryptotis tropicalis (Merriam 1895). I review the taxonomic history of these specimens, provide current identifications tied directly to museum register numbers, describe how to distinguish the three species, and provide revised synonymies for these species.

Racial and ethnic disparities in dental care for publicly insured children.

PubMed

Pourat, Nadereh; Finocchio, Len

2010-07-01

Poor oral health has important implications for the healthy development of children. Children in Medicaid, especially Latinos and African Americans, experience high rates of tooth decay, yet they visit dentists less often than privately insured children. Even Latino and African American children with private insurance are less likely than white children to visit dentists and have longer intervals between dental visits. Furthermore, Latino and African American children in Medicaid are more likely than white children in Medicaid to have longer intervals between visits. These findings raise concerns about Medicaid's ability to address disparities in dental care access and, more broadly, in health care.

The abrasive effect of commercial whitening toothpastes on eroded enamel.

PubMed

Mosquim, Victor; Martines Souza, Beatriz; Foratori Junior, Gerson Aparecido; Wang, Linda; Magalhães, Ana Carolina

2017-06-01

To evaluate the in vitro abrasive effect of commercial whitening toothpastes on eroded bovine enamel samples in respect to erosive tooth wear. 72 bovine crowns were embedded, polished and subjected to the baseline profile analysis. The samples were then protected in 2/3 of the enamel surface and were randomly assigned to six groups (n= 12/group): G1: Oral-B 3D White, G2: Close-up Diamond Attraction Power White, G3: Sorriso Xtreme White 4D, G4: Colgate Luminous White, G5: Crest (conventional toothpaste), G6:erosion only (control). All samples were submitted to an erosive pH cycling (4 x 90 seconds in 0.1% citric acid, pH 2.5, per day) and abrasive challenges (2 x 15 seconds, per day) for 7 days. After the first and the last daily cycles, the samples were subjected to abrasive challenges, using a toothbrushing machine, soft toothbrushes and slurry of the tested toothpastes (1.5 N). Between the challenges, the samples were immersed in artificial saliva. The final profile was obtained and overlaid to the baseline profile for the calculation of the erosive tooth wear (μm). The data were subjected to Kruskal-Wallis/Dunn tests (P< 0.05). G1 promoted the highest enamel wear (3.68±1.06 μm), similarly to G3 (3.17± 0.80 μm) and G4 (3.44± 1.29 μm). G3 and G4 performed similarly between them and compared with G5 (2.35± 1.44 μm). G2 (1.51± 0.95 μm) and G6 (0.85± 0.36 μm) showed the lowest enamel wear, which did not differ between them and from G5. Oral-B 3D White showed the highest abrasive potential while Close-up Diamond Attraction Power White showed the lowest abrasive potential on eroded enamel in vitro. This study showed that some commercial whitening toothpastes, especially those containing pyrophosphate associated with hydrated silica, enhanced enamel erosive wear.

Adverse effects associated with the clinical use of 4% TiF₄ on teeth enamel: case report.

PubMed

Pedro, Rafael de Lima; Pomarico, Luciana; Villardi, Michele; Maia, Lucianne Cople

2011-05-01

Titanium tetrafluoride (TiF₄) has been studied in dentistry as a promissory alternative for prevention and treatment of carious lesions. However, there are few in vivo studies concerning the consequences of its use on tooth enamel. The goal of this study was to report the effects of a 4% TiF₄ application on the remineralization of an incipient carious lesion of a permanent tooth. This research found an unexpected clinical outcome. A patient with active white spots had two of these lesions treated with 4% TiF₄ associated with fluoridated dentifrice and another lesion treated with fluoridated dentifrice only, thus the remineralization of the two kinds of treatment administered could be observed and compared. An extrinsic pigment appeared in the regions that received the TiF₄ treatment, which was partially removed by professional prophylaxis. Also, regular recidivists of this pigmentation in the review consultations were noted. The authors concluded that although the use of 4% TiF₄ was effective in treating incipient carious lesions on enamel, it was also responsible for an undesired pigmented layer on the tooth to which it was applied. Beyond the varied fluoridated materials used in dentistry, titanium tetrafluoride (TiF₄) deserves attention. This compound has the common properties of fluorides, and researchers are exploring its role in carious lesion prevention, fissure sealing, and tooth erosion prevention in in vitro and in situ studies. Research is also exploring its use for microinfiltration prevention in tooth restoration and hypersensitivity treatment. However, when compared to other fluoridated products TiF₄ demonstrates additional, specific particularities, such as the formation of a titanium dioxide (TiO₂) layer, which is tough, hydrophobic, and resistant in acidic environments. Nevertheless, there are insufficient in vivo studies concerning the consequences of TiF₄-containing products affecting tooth enamel. Thus, the goals of this study were to report the effects of a 4% TiF₄ application on the remineralization of an incipient carious lesion of a permanent tooth and to show the results of a backscattered scanning electron (BSE) analysis that was performed on the primary tooth. The clinical outcome was unexpected.

Relapsing remitting multiple sclerosis in x-linked charcot-marie-tooth disease with central nervous system involvement.

PubMed

Koutsis, Georgios; Karadima, Georgia; Floroskoufi, Paraskewi; Raftopoulou, Maria; Panas, Marios

2015-01-01

We report a patient with relapsing remitting multiple sclerosis (MS) and X-linked Charcot-Marie-Tooth disease (CMTX), carrying a GJB1 mutation affecting connexin-32 (c.191G>A, p. Cys64Tyr) which was recently reported by our group. This is the third case report of a patient with CMTX developing MS, but it is unique in the fact that other family members carrying the same mutation were found to have asymptomatic central nervous system (CNS) involvement (diffuse white matter hyperintensity on brain MRI and extensor plantars). Although this may be a chance association, the increasing number of cases with CMTX and MS, especially with mutations involving the CNS, may imply some causative effect and provide insights into MS pathogenesis.

Relapsing Remitting Multiple Sclerosis in X-Linked Charcot-Marie-Tooth Disease with Central Nervous System Involvement

PubMed Central

Karadima, Georgia; Floroskoufi, Paraskewi; Raftopoulou, Maria; Panas, Marios

2015-01-01

We report a patient with relapsing remitting multiple sclerosis (MS) and X-linked Charcot-Marie-Tooth disease (CMTX), carrying a GJB1 mutation affecting connexin-32 (c.191G>A, p. Cys64Tyr) which was recently reported by our group. This is the third case report of a patient with CMTX developing MS, but it is unique in the fact that other family members carrying the same mutation were found to have asymptomatic central nervous system (CNS) involvement (diffuse white matter hyperintensity on brain MRI and extensor plantars). Although this may be a chance association, the increasing number of cases with CMTX and MS, especially with mutations involving the CNS, may imply some causative effect and provide insights into MS pathogenesis. PMID:25883816

The evolution of micro-cursoriality in mammals.

PubMed

Lovegrove, Barry G; Mowoe, Metobor O

2014-04-15

In this study we report on the evolution of micro-cursoriality, a unique case of cursoriality in mammals smaller than 1 kg. We obtained new running speed and limb morphology data for two species of elephant-shrews (Elephantulus spp., Macroscelidae) from Namaqualand, South Africa, which we compared with published data for other mammals. Elephantulus maximum running speeds were higher than those of most mammals smaller than 1 kg. Elephantulus also possess exceptionally high metatarsal:femur ratios (1.07) that are typically associated with fast unguligrade cursors. Cursoriality evolved in the Artiodactyla, Perissodactyla and Carnivora coincident with global cooling and the replacement of forests with open landscapes in the Oligocene and Miocene. The majority of mammal species, though, remained non-cursorial, plantigrade and small (<1 kg). The extraordinary running speed and digitigrady of elephant-shrews was established in the Early Eocene in the earliest macroscelid Prodiacodon, but was probably inherited from Paleocene, Holarctic stem macroscelids. Micro-cursoriality in macroscelids evolved from the plesiomorphic plantigrade foot of the possum-like ancestral mammal earlier than in other mammalian crown groups. Micro-cursoriality evolved first in forests, presumably in response to selection for rapid running speeds facilitated by local knowledge, in order to avoid predators. During the Miocene, micro-cursoriality was pre-adaptive to open, arid habitats, and became more derived in the newly evolved Elephantulus and Macroscelides elephant-shrews with trail running.

Prevalence of zoonotic Bartonella species among rodents and shrews in Thailand.

PubMed

Pangjai, Decha; Maruyama, Soichi; Boonmar, Sumalee; Kabeya, Hidenori; Sato, Shingo; Nimsuphan, Burin; Petkanchanapong, Wimol; Wootta, Wattanapong; Wangroongsarb, Piyada; Boonyareth, Maskiet; Preedakoon, Poom; Saisongkorh, Watcharee; Sawanpanyalert, Pathom

2014-03-01

We investigated the prevalence of Bartonella species in 10 rodent and one shrew species in Thailand. From February 2008 to May 2010, a total of 375 small animals were captured in 9 provinces in Thailand. Bartonella strains were isolated from 57 rodents (54 from Rattus species and 3 from Bandicota indica) and one shrew (Suncus murinus) in 7 of the 9 provinces, and identified to the species level. Sequence analysis of the citrate synthase and RNA polymerase β subunit genes identified the 58 isolates from each Bartonella-positive animal as B. tribocorum in 27 (46.6%) animals, B. rattimassiliensis in 17 (29.3%) animals, B. elizabethae in 10 (17.2%) animals and B. queenslandensis in 4 (6.9%) animals. R. norvegicus, R. rattus, and Suncus murinus carried B. elizabethae, which causes endocarditis in humans. The prevalence of Bartonella bacteremic animals by province was 42.9% of the animals collected in Phang Nga, 26.8% in Chiang Rai, 20.4% in Sa Kaeo, 16.7% in Nakhon Si Thammarat, 12.0% in Surat Thani, 9.1% in Mae Hong Son and Loei Provinces. These results indicate that Bartonella organisms are widely distributed in small mammals in Thailand and some animal species may serve as important reservoirs of zoonotic Bartonella species in the country. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Nuclear organisation of some immunohistochemically identifiable neural systems in five species of insectivore-Crocidura cyanea, Crocidura olivieri, Sylvisorex ollula, Paraechinus aethiopicus and Atelerix frontalis.

PubMed

Calvey, Tanya; Patzke, Nina; Bennett, Nigel C; Consolate, Kaswera-Kyamakya; Gilissen, Emmanuel; Alagaili, Abdulaziz N; Mohammed, Osama B; Pettigrew, John D; Manger, Paul R

2016-03-01

The organization of the cholinergic, catecholaminergic, and serotonergic neurons in the brains of five species of insectivores and the orexinergic (hypocretinergic) system in four insectivore species is presented. We aimed to investigate the nuclear complement of these neural systems in comparison to those of other mammalian species. Brains of insectivores were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei were similar among the species investigated and to mammals in general, but certain differences in the nuclear complement highlighted potential phylogenetic interrelationships. In the cholinergic system, the three shrew species lacked parabigeminal and Edinger-Westphal nuclei. In addition, the appearance of the laterodorsal tegmental nucleus in all insectivores revealed a mediodorsal arch. All three of these features are the same as those present in microchiropterans. The catecholaminergic system of the three shrew species lacked the A4 and A15d nuclei, as well as having an incipient A9v nucleus, again features found in microchiropteran brains. The serotonergic and orexinergic systems of the insectivores are similar to those seen across most eutherian mammals. The analysis of similarities and differences across mammalian species indicates a potential phylogenetic relationship between the Soricidae (shrews) and the microchiropterans. Copyright © 2015 Elsevier B.V. All rights reserved.

Receptor-Selective Agonists Induce Emesis and Fos Expression in the Brain and Enteric Nervous System of the Least Shrew (Cryptotis parva)

PubMed Central

Ray, Andrew P.; Chebolu, Seetha; Darmani, Nissar A.

2009-01-01

Research on the mechanisms of emesis has implicated multiple neurotransmitters via both central (dorsal vagal complex) and peripheral (enteric neurons and enterochromaffin cells) anatomical substrates. Taking advantage of advances in receptor-specific agonists, and utilizing Fos expression as a functional activity marker, this study demonstrates a strong, but incomplete, overlap in anatomical substrates for a variety of emetogens. We used cisplatin and specific agonists to 5-HT3 serotonergic, D2/D3 dopaminergic, and NK1 tachykininergic receptors to induce vomiting in the least shrew (Cryptotis parva), and quantified the resulting Fos expression. The least shrew is a small mammal whose responses to emetic challenges are very similar to its human counterparts. In all cases, the enteric nervous system, nucleus of the solitary tract, and dorsal motor nucleus of the vagus demonstrated significantly increased Fos immunoreactivity (Fos-IR). However, Fos-IR induction was notably absent from the area postrema following the dopaminergic and NK1 receptor-specific agents. Two brain nuclei not usually discussed regarding emesis, the dorsal raphe nucleus and paraventricular thalamic nucleus, also demonstrated increased emesis-related Fos-IR. Taken together, these data suggest the dorsal vagal complex is part of a common pathway for a variety of distinct emetogens, but there are central emetic substrates, both medullary and diencephalic, that can be accessed without directly stimulating the area postrema. PMID:19699757

Release brochure for Amethyst Germplasm Hoary Tansyaster (Machaeranthera canescens)

Treesearch

Derek Tilley

2014-01-01

Hoary tansyaster is a short-lived perennial forb with pale to dark purple flowers. Plants are 6 to 30 inches tall with diffuse branching. Leaves are about 2 inches long and oblong or lance shaped with entire to sharply toothed margin. The flower heads have many subtending bracts that reflex away from the flower at the tip. These bracts are white and membranous at the...

The use of different analgesics in orthodontic tooth movements.

PubMed

Hammad, Shaza M; El-Hawary, Yousry M; El-Hawary, Amira K

2012-09-01

To provide a semi-quantitative assessment of the effect of different analgesics (celecoxib, ketorolac, and paracetamol) on tooth movement and bone resorption using immunohistochemical staining of matrix metalloproteinase-13 (MMP-13). Forty white male rats (12-weeks old; body weight: 230-250 g) were divided into four groups (10 rats each) and were given the treatment once a day for 2 consecutive months. Group A (control group) rats were given the reverse osmosis water; group B rats were given 10 mg/kg celecoxib; group C rats were given 3 mg/kg ketorolac; and group D rats were given 150 mg/kg paracetamol. A precalibrated closed Sentalloy coil spring was placed inside each rat mouth to deliver a constant force of 50 cN. The magnitude of tooth movement was measured intraorally. After 2 months, the rats were sacrificed, and the sections were mounted on L-polylysine-coated glass slides. Slides from each specimen were stained with hematoxylin and eosin, and others were stained with MMP-13. Data were analyzed with the one-way analysis of variance (ANOVA). Celecoxib, ketorolac, and paracetamol groups showed tooth movement of 1.81 ± 0.43 mm, 1.13 ± 0.28 mm, and 1.08 ± 0.27 mm, respectively. The mean number of MMP-13-positive osteoclasts was highest in celecoxib-treated group followed by the control group and was decreased in the ketorolac and paracetamol groups. Comparing all groups to the control revealed significant differences (P < .05). Administration of celecoxib did not reduce bone resorption or interfere with tooth movement in rats compared to other analgesics tested (ketorolac and paracetamol).

[Chromatic study of all-ceramic crown--IPS Empress: difference of color by manufacturing technique and cements].

PubMed

Hata, Utako; Sadamitsu, Kenichiro; Yamamura, Osamu; Kawauchi, Daisuke; Fujii, Teruhisa

2004-12-01

In recent years,aesthetic appearance and function are called for and all-ceramic crowns are spreading. By choosing an all-ceramic crown the problem of metal ceramics is avoided. There are difficulties of color tone reproducibility of cervical margin and darkness of gingival margin. We examined IPS Empress also in various all-ceramic crowns. IPS Empress has high permeability a ceramic ingot of various color tones and excellent color tone reproducibility of natural teeth. Generally a layering technique is used for an anterior tooth and the staining technique is used for a molar. However the details are unknown We examined how differences of manufacturing method and cement affect the color tone of all ceramics clinically. Two kinds of Empress crown were fabricated for a 27 year-old woman's upper left-side central incisors:the staining technique of IPS Empress and the layering technique of IPS Empress II. Various try-in pastes(transparent opaque white white and yellow) of VariolinkII of the IPS Empress System were used for cementing. Color was measured using a spectrophotometer CMS 35FS. The L*a*b* color system was used for showing a color. The right-side central incisors on the opposite side of the same name teeth were used for comparison. We analyzed the color difference (DeltaE* ab)with a natural tooth. Consequently when it had no cement of staining technique and was tranceparent small values were obtained. It is considered that the color tone can be adjusted by color cement. It is effective to use the staining technique for an anterior tooth crown depending on the case. The crown manufactured using the layering technique is not easily influenced by cement. The crown manufactured by the staining technique tends to be influenced by cement.

Fossil shrews from Honduras and their significance for late glacial evolution in body size (Mammalia: Soricidae: Cryptotis)

USGS Publications Warehouse

Woodman, N.; Croft, D.A.

2005-01-01

Our study of mammalian remains excavated in the 1940s from McGrew Cave, north of Copan, Honduras, yielded an assemblage of 29 taxa that probably accumulated predominantly as the result of predation by owls. Among the taxa present are three species of small-eared shrews, genus Cryptotis. One species, Cryptotis merriami, is relatively rare among the fossil remains. The other two shrews, Cryptotis goodwini and Cryptotis orophila, are abundant and exhibit morpho metrical variation distinguishing them from modern populations. Fossils of C. goodwini are distinctly and consistently smaller than modern members of the species. To quantify the size differences, we derived common measures of body size for fossil C. goodwini using regression models based on modern samples of shrews in the Cryptotis mexicana-group. Estimated mean length of head and body for the fossil sample is 72-79 mm, and estimated mean mass is 7.6-9.6 g. These numbers indicate that the fossil sample averaged 6-14% smaller in head and body length and 39-52% less in mass than the modern sample and that increases of 6-17% in head and body length and 65-108% in mass occurred to achieve the mean body size of the modern sample. Conservative estimates of fresh (wet) food intake based on mass indicate that such a size increase would require a 37-58% increase in daily food consumption. In contrast to C. goodwini, fossil C. orophila from the cave is not different in mean body size from modern samples. The fossil sample does, however, show slightly greater variation in size than is currently present throughout the modern geographical distribution of the taxon. Moreover, variation in some other dental and mandibular characters is more constrained, exhibiting a more direct relationship to overall size. Our study of these species indicates that North American shrews have not all been static in size through time, as suggested by some previous work with fossil soricids. Lack of stratigraphic control within the site and our failure to obtain reliable radiometric dates on remains restrict our opportunities to place the site in a firm temporal context. However, the morphometrical differences we document for fossil C. orophila and C. goodwini show them to be distinct from modern populations of these shrews. Some other species of fossil mammals from McGrew Cave exhibit distinct size changes of the magnitudes experienced by many northern North American and some Mexican mammals during the transition from late glacial to Holocene environmental conditions, and it is likely that at least some of the remains from the cave are late Pleistocene in age. One curious factor is that, whereas most mainland mammals that exhibit large-scale size shifts during the late glacial/postglacial transition experienced dwarfing, C. goodwini increased in size. The lack of clinal variation in modern C. goodwini supports the hypothesis that size evolution can result from local selection rather than from cline translocation. Models of size change in mammals indicate that increased size, such as that observed for C. goodwini, are a likely consequence of increased availability of resources and, thereby, a relaxation of selection during critical times of the year.

Comparison of the clinical effects of white brand toothbrushes versus Vitis Suave®

PubMed Central

Segarra-Vidal, Marta; Lucas-Alcahuz, Eduardo; López-Roldán, Andrés; Gil-Loscos, Francisco; Alpiste-Illueca, Francisco

2015-01-01

Background There has been an increase in the use of white label manual toothbrushes and a greater increase in inquiries for discomfort of the gingiva and mucosa. Material and Methods A randomized, double-blind, cross-over clinical trial was made of four white brand toothbrushes versus a control brush (Vitis Suave®), with the recording of plaque index, bleeding upon probing, and gingival abrasions following utilization of the different brushes. Results All the brushes except Deliplus® were equally effective in terms of plaque removal (p<0.05). Vitis Suave® and Veckia® were the brushes associated to the greatest increase in minor abrasions (p<0.01), while Veckia®, Carrefour® and Deluxe® significantly increased the number of medium intensity abrasions (p<0.05). These brushes also increased the number of large abrasions, though statistical significance was not reached in this case. Conclusions The white brand brushes proved effective in controlling bacterial plaque, but were associated to more intense soft tissue abrasion. Key words:Gingival abrasions, manual tooth brushing, white brand, clinical effects. PMID:26535095

Knowledge, attitude, willingness and readiness of primary health care providers to provide oral health services to children in Niagara, Ontario: a cross-sectional survey.

PubMed

Singhal, Sonica; Figueiredo, Rafael; Dupuis, Sandy; Skellet, Rachel; Wincott, Tara; Dyer, Carolyn; Feller, Andrea; Quiñonez, Carlos

2017-01-01

Most children are exposed to medical, but not dental, care at an early age, making primary health care providers an important player in the reduction of tooth decay. The goal of this research was to understand the feasibility of using primary health care providers in promoting oral health by assessing their knowledge, attitude, willingness and readiness in this regard. Using the Dillman method, a mail-in cross-sectional survey was conducted among all family physicians and pediatricians in the Niagara region of Ontario who have primary contact with children. A descriptive analysis was performed. Close to 70% (181/265) of providers responded. More than 90% know that untreated tooth decay could affect the general health of a child. More than 80% examine the oral cavity for more than 50% of their child patients. However, more than 50% are not aware that white spots or lines on the tooth surface are the first signs of tooth decay. Lack of clinical time was the top reason for not performing oral disease prevention measures. Overall, survey responses show a positive attitude and willingness to engage in the oral health of children. To capitalize on this, there is a need to identify mechanisms of providing preventive oral health care services by primary health care providers; including improving their knowledge of oral health and addressing other potential barriers.

Evaluation of arch form between Vietnamese and North American Caucasians using 3-dimensional virtual models.

PubMed

Trang, Vu Thi Thu; Park, Jae Hyun; Bayome, Mohamed; Shastry, Shruti; Mellion, Alex; Kook, Yoon-Ah

2015-01-01

The purpose of this study was to investigate the three-dimensional (3D) morphologic differences in the mandibular arch of Vietnamese and North American White subjects. The sample included 113 Vietnamese subjects (41 Class I, 37 Class II and 35 Class III) and 96 White subjects (29 Class I, 30 Class II and 37 Class III). The samples were regrouped according to arch form types (tapered, ovoid, and square) to compare the frequency distribution of the three arch forms between ethnic groups in each angle classification. The facial axis point of each tooth was digitized on 3D virtual models. Four linear and two ratio variables were measured. In comparing arch dimensions, the intercanine and intermolar widths were wider in Vietnamese than in Whites (p < 0.001, p = 0.042, respectively). In the White group, there was even frequency distribution of the three arch forms. However, in the Vietnamese group, the square arch form was the most frequent followed by tapered and ovoid arch forms. The arch forms of Whites were narrower than Vietnamese. In North American Whites, the distribution of the arch form types showed similar frequency. In Vietnamese, the square arch form was more frequent.

Effect of EDTA conditioning upon the retention of fibre posts luted with resin cements.

PubMed

Rasimick, B J; Shah, R P; Musikant, B L; Deutsch, A S

2008-12-01

To determine if a final rinse with EDTA improves the short-term in-tooth retentive strength of adhesively luted fibre-reinforced composite posts. Six different commercial fibre post systems were tested. Post spaces in extracted human anterior teeth were irrigated with either 6% NaOCl or 6% NaOCl followed by 17% EDTA. Posts were luted using the manufacturer's recommended bonding agent and luting cement. Two different sizes of post were tested for each post system. After 24 h of storage, the retentive strength of the post to the tooth (14 per group, 336 total) was tested using a pull-out technique. Three-way anova and the Student-Newman-Kuels test were used to test the effects of irrigation regimen, post size and post brand on the retentive strength of the fibre post. Almost every sample failed at the interface between dentine and luting cement. Irrigation method did not have any significant effect (P > 0.14) for any group other than ParaPost Fibre White (P < 0.001). The overall retention of a post appeared to be correlated to the amount of surface texture on the post; the smooth ICEPost was the least retentive brand, the textured FibreKor and the ParaPost Fibre White posts were moderately retained, and the threaded Flexi-Post Fibre and the Flexi-Flange Fibre posts were the most retentive brands tested. For all brands, larger diameter posts were more retentive than smaller diameter posts (P < 0.008). A final rinse of EDTA did not improve the short-term retention of fibre posts except for ParaPost Fibre White.

Efficacy of mouth rinses and toothpaste on tooth whitening.

PubMed

Torres, C R G; Perote, L C C C; Gutierrez, N C; Pucci, C R; Borges, A B

2013-01-01

People increasingly desire tooth whitening. Considering the wide range of whitening products on the market, this study evaluated the efficacy of whitening toothpastes and mouth rinses compared with the 10% carbamide peroxide (CP) whitening gel. We obtained 120 cylindrical specimens from bovine teeth, which were darkened for 24 hours in a coffee solution. The color measurement was performed by a spectrophotometer using the CIE L*a*b* system, and specimens were divided into six groups according to the use of the following agents: group 1, conventional fluoridated toothpaste; group 2, Close Up White Now; group 3, Listerine Whitening; group 4, Colgate Plax Whitening; group 5, experimental mouth rinse with Plasdone; and group 6, 10% CP Whiteness Perfect. After the simulation of 12 weeks of treatment for groups 1 to 5 and 14 days of treatment for group 6, the specimens were subjected to a new color reading. Data were subjected to one-way analysis of variance (α=0.05), which showed significant differences among groups after 12 weeks for ΔE (p=0.001). Results of the Tukey test revealed that groups 3, 4, and 6 presented significantly higher color alteration than groups 1, 2, and 5. The whitening toothpaste Close Up White Now and the experimental mouth rinse with Plasdone showed similar color alteration as conventional toothpaste after a 12-week treatment simulation. These groups presented significantly lower color alteration compared with whitening mouth rinses Listerine and Colgate Plax Whitening, which showed similar results to those observed after 14 days of bleaching with 10% CP treatment.

Megabrasion: a conservative strategy for the anterior dentition.

PubMed

Magne, P

1997-05-01

Continuous developments in adhesive restorative techniques, tooth whitening procedures, and restorative materials have significantly broadened the initially defined spectrum of indications for composite restorations. These developments have thereby contributed to the achievement of one of the major objectives of conservative restorative dentistry--the maximum preservation of sound tooth structure. In order to optimize the application of modern composite resin technology, mastering the basic principles of natural aesthetics is an essential prerequisite. The learning objective of this article is to discuss the etiology of enamel discoloration and conservative treatment strategies, including microabrasion and masking procedures. Emphasis is placed on a simple procedure--the megabrasion technique--which does not depend extensively on the artistic skills of the operator. It represents a useful and predictable approach for the elimination of white opaque stains on the enamel and yellow-brown enamel discolorations.

Intracortical Microstimulation Maps of Motor, Somatosensory, and Posterior Parietal Cortex in Tree Shrews (Tupaia belangeri) Reveal Complex Movement Representations.

PubMed

Baldwin, Mary K L; Cooke, Dylan F; Krubitzer, Leah

2017-02-01

Long-train intracortical microstimulation (LT-ICMS) is a popular method for studying the organization of motor and posterior parietal cortex (PPC) in mammals. In primates, LT-ICMS evokes both multijoint and multiple-body-part movements in primary motor, premotor, and PPC. In rodents, LT-ICMS evokes complex movements of a single limb in motor cortex. Unfortunately, very little is known about motor/PPC organization in other mammals. Tree shrews are closely related to both primates and rodents and could provide insights into the evolution of complex movement domains in primates. The present study investigated the extent of cortex in which movements could be evoked with ICMS and the characteristics of movements elicited using both short train (ST) and LT-ICMS in tree shrews. We demonstrate that LT-ICMS and ST-ICMS maps are similar, with the movements elicited with ST-ICMS being truncated versions of those elicited with LT-ICMS. In addition, LT-ICMS-evoked complex movements within motor cortex similar to those in rodents. More complex movements involving multiple body parts such as the hand and mouth were also elicited in motor cortex and PPC, as in primates. Our results suggest that complex movement networks present in PPC and motor cortex were present in mammals prior to the emergence of primates. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The Asian house shrew Suncus murinus as a reservoir and source of human outbreaks of plague in Madagascar.

PubMed

Rahelinirina, Soanandrasana; Rajerison, Minoarisoa; Telfer, Sandra; Savin, Cyril; Carniel, Elisabeth; Duplantier, Jean-Marc

2017-11-01

Identifying key reservoirs for zoonoses is crucial for understanding variation in incidence. Plague re-emerged in Mahajanga, Madagascar in the 1990s but there has been no confirmed case since 1999. Here we combine ecological and genetic data, from during and after the epidemics, with experimental infections to examine the role of the shrew Suncus murinus in the plague epidemiological cycle. The predominance of S. murinus captures during the epidemics, their carriage of the flea vector and their infection with Yersinia pestis suggest they played an important role in the maintenance and transmission of plague. S. murinus exhibit a high but variable resistance to experimental Y. pestis infections, providing evidence of its ability to act as a maintenance host. Genetic analyses of the strains isolated from various hosts were consistent with two partially-linked transmission cycles, with plague persisting within the S. murinus population, occasionally spilling over into the rat and human populations. The recent isolation from a rat in Mahajanga of a Y. pestis strain genetically close to shrew strains obtained during the epidemics reinforces this hypothesis and suggests circulation of plague continues. The observed decline in S. murinus and Xenopsylla cheopis since the epidemics appears to have decreased the frequency of spillover events to the more susceptible rats, which act as a source of infection for humans. Although this may explain the lack of confirmed human cases in recent years, the current circulation of plague within the city highlights the continuing health threat.

Ultrastructural Examination of Diffuse and Specific Tectopulvinar Projections in the Tree Shrew

PubMed Central

CHOMSUNG, RANIDA D.; PETRY, HEYWOOD M.; BICKFORD, MARTHA E.

2008-01-01

Two pathways from the superior colliculus (SC) to the tree shrew pulvinar nucleus have been described, one in which the axons terminate in dense (or specific) patches and one in which the axon arbors are more diffusely organized (Luppino et al. [1988] J. Comp. Neurol. 273:67– 86). As predicted by Lyon et al. ([2003] J. Comp. Neurol. 467:593– 606), we found that anterograde labeling of the diffuse tectopulvinar pathway terminated in the acetylcholinesterase (AChE)-rich dorsal pulvinar (Pd), whereas the specific pathway terminated in the AChE-poor central pulvinar (Pc). Injections of retrograde tracers in Pd labeled non-γ-aminobutyric acid (GABA)-ergic wide-field vertical cells located in the lower stratum griseum superficiale and stratum opticum of the medial SC, whereas injections in Pc labeled similar cells in more lateral regions. At the ultrastructural level, we found that tectopulvinar terminals in both Pd and Pc contact primarily non-GABAergic dendrites. When present, however, synaptic contacts on GABAergic profiles were observed more frequently in Pc (31% of all contacts) compared with Pd (16%). Terminals stained for the type 2 vesicular glutamate transporter, a potential marker of tectopulvinar terminals, also contacted more GABAergic profiles in Pc (19%) compared with Pd (4%). These results provide strong evidence for the division of the tree shrew pulvinar into two distinct tectorecipient zones. The potential functions of these pathways are discussed. J. Comp. Neurol. 510:24 – 46, 2008. PMID:18615501

The Stephen H. Long Expedition (1819?1820), Titian R. Peale?s field illustrations, and the lost holotypes of the North American shrews Sorex brevicaudus Say and Sorex parvus Say (Mammalia: Soricidae) from the Philadelphia Museum

USGS Publications Warehouse

Woodman, N.

2009-01-01

While encamped for the winter of 1819?1820 at Engineer Cantonment along the Missouri River in present-day eastern Nebraska, members of Major Stephen Harriman Long?s Expedition to the Rocky Mountains collected a number of animals that were previously unknown. Among the mammals were two soricids that were subsequently described by Thomas Say as Sorex brevicaudus (Northern Short-tailed Shrew, Blarina brevicauda) and Sorex parvus (Least Shrew, Cryptotis parvus). The holotypes of these species were deposited and placed on public exhibit in the Philadelphia Museum, the predominant North American systematic collection of the early nineteenth century. Like most private museums of that era, the Philadelphia Museum eventually went out of business, and its collections were dispersed and, for the most part, lost. Fortunately, Titian R. Peale made a detailed field sketch of the two specimens soon after their capture and subsequently executed a watercolor based on that sketch. In addition, an engraving of the holotypes was published in the decade following the discovery of the two species. Illustrations of holotypes are taxonomically useful when they depict diagnostic characters of species. They take on added taxonomic significance in the absence of the holotypes. In the cases of Sorex brevicaudus and Sorex parvus, pictures provide strong confirmation of the taxonomic identities of these two species, as well as recording the early history of the specimens.

Polychlorinated biphenyls and their hydroxylated metabolites (OH-PCBs) in the blood of toothed and baleen whales stranded along Japanese coastal waters.

PubMed

Nomiyama, Kei; Murata, Satoko; Kunisue, Tatsuya; Yamada, Tadasu K; Mizukawa, Hazuki; Takahashi, Shin; Tanabe, Shinsuke

2010-05-15

In this study, we determined the residue levels and patterns of polychlorinated biphenyls (PCBs) and hydroxylated PCBs (OH-PCBs) in the blood from eight species of toothed whales and three species of baleen whales stranded along the Japanese coast during 1999-2007. Penta- through hepta-chlorinated PCB congeners were the dominant homologue groups in all cetaceans. In contrast, specific differences in the distribution of dominant OH-PCB isomers and homologues were found among the cetacean species. In five species of toothed whales (melon-headed whale, Stejneger's beaked whale, Pacific white-sided dolphin, Blainville's beaked whale, and killer whale), the predominant homologues were OH-penta-PCBs followed by OH-tetra-PCBs and OH-tri-PCBs. The predominant homologues of finless porpoise and beluga whale were OH-penta-PCBs followed by OH-hexa-PCBs and OH-tri-PCBs. The predominant OH-PCB isomers were para-OH-PCBs such as 4OH-CB26, 4'OH-CB25/4'OH-CB26/4OH-CB31, 4OH-CB70, 4'OH-CB72, 4'OH-CB97, 4'OH-CB101/4'OH-CB120, and 4OH-CB107/4'OH-CB108 in toothed whales. In three baleen whales (common minke whale, Bryde's whale, and humpback whale) and in sperm whale (which is a toothed whale), OH-octa-PCB (4OH-CB202) was the predominant homologue group accounting for 40-80% of the total OH-PCB concentrations. The differences in concentrations and profiles of OH-PCBs may suggest species-specific diets, metabolic capability, and the transthyretin (TTR) binding specificity. These results reveal that the accumulation profiles of OH-PCBs in cetacean blood are entirely different from the profiles found in pinnipeds, polar bear, and humans.

Prevalence of lesions in incisors of mule deer from Colorado Springs, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borrero, L.M.; Scanlon, P.F.

1995-12-31

Lesions in teeth may be influenced by exposure to fluorides, malnutrition and trauma. Incisors of 228 mule deer (Odocoileus hemionus) taken from the USAF Academy, Colorado Springs, CO during the 1993 hunting season were examined for lesions. A classification scheme (scale = 0--5) for lesions was derived from the method of Shupe et al. 1963. Lesions were present in at least one incisor of 84.6% of deer. Of the deer with lesions, 86% had at least one tooth with very slight effect (one to few white spots), 9.8% had a slight effect (generalized mottling), 2.6% had a moderate effect (generalizedmore » mottling and wear), 10.04% had a marked effect (mottling and hypoplasia of the enamel) , and 0.5 % ad severe effects (hypoplasia of the enamel and abnormal wear). Lesions that affect the enamel are produced during the period of formation of the tooth. The severity of lesions depends on the cause and the length of exposure to the causative agent. Generally mottling and hypoplasia of the enamel are associated with fluorosis. The relationship of lesions to bone and tooth fluoride concentrations was examined.« less

Influence of unilateral tooth loss in the temporomandibular joint and masseter muscle of rabbits.

PubMed

Im, Jae-Hyung; Kim, Su-Gwan; Oh, Ji-Su; Lim, Sung-Chul; Ha, Jung-Min

2012-07-01

The purpose of this study was to evaluate the influence of the masticatory system in patients with missing teeth. The influence of tooth loss on the masticatory system was analyzed with the use of bone scintigraphy ((99m)Tc-MDP) and histochemistry. Eight white rabbits (New Zealand, 12 weeks old) were used. The rabbits were divided into 2 groups: 6 weeks and 12 weeks. Teeth were extracted unilaterally in each rabbit under general anesthesia. Six and 12 weeks after extraction, scintigraphy was conducted, and the rabbits were killed and their masseter muscles removed for histochemical analysis. The results of bone metabolism (relative ratio) measured by bone scintigraphy were 48.27% at extraction sites and 51.73% at nonextraction sites at 6 weeks and 39.96% at extraction sites and 60.04% at nonextraction sites at 12 weeks. There was a significant difference at 12 weeks (P < .05). Tissue calcium contents and osteoclast counts showed different results between the extraction and nonextraction sites, but these differences did not reach statistical significance. The bone metabolism of temporomandibular joints and histochemical aspects of masticatory muscles may be associated with occlusal alterations following tooth loss. Copyright © 2012 Elsevier Inc. All rights reserved.

What is the critical pH and why does a tooth dissolve in acid?

PubMed

Dawes, Colin

2003-12-01

This paper discusses the concept of critical pH for dissolution of enamel in oral fluids. The critical pH does not have a fixed value but rather is inversely proportional to the calcium and phosphate concentrations in the solution. The paper also discusses why teeth dissolve in acid, why remineralization of white-spot caries lesions is possible and why remineralization of teeth eroded by acid is not possible.

Knowledge, attitude, willingness and readiness of primary health care providers to provide oral health services to children in Niagara, Ontario: a cross-sectional survey

PubMed Central

Singhal, Sonica; Figueiredo, Rafael; Dupuis, Sandy; Skellet, Rachel; Wincott, Tara; Dyer, Carolyn; Feller, Andrea; Quiñonez, Carlos

2017-01-01

Background: Most children are exposed to medical, but not dental, care at an early age, making primary health care providers an important player in the reduction of tooth decay. The goal of this research was to understand the feasibility of using primary health care providers in promoting oral health by assessing their knowledge, attitude, willingness and readiness in this regard. Methods: Using the Dillman method, a mail-in cross-sectional survey was conducted among all family physicians and pediatricians in the Niagara region of Ontario who have primary contact with children. A descriptive analysis was performed. Results: Close to 70% (181/265) of providers responded. More than 90% know that untreated tooth decay could affect the general health of a child. More than 80% examine the oral cavity for more than 50% of their child patients. However, more than 50% are not aware that white spots or lines on the tooth surface are the first signs of tooth decay. Lack of clinical time was the top reason for not performing oral disease prevention measures. Interpretation: Overall, survey responses show a positive attitude and willingness to engage in the oral health of children. To capitalize on this, there is a need to identify mechanisms of providing preventive oral health care services by primary health care providers; including improving their knowledge of oral health and addressing other potential barriers. PMID:28401141

Clinical comparison of Colgate Platinum Toothwhitening System and Rembrandt Gel Plus.

PubMed

Kowitz, G M; Nathoo, S A; Rustogi, K N; Chmielewski, M B; Liang, L J; Wong, R

1994-01-01

A 2-week, three-cell study was conducted to evaluate the tooth-whitening efficacy of the Colgate Platinum Professional Toothwhitening System vs Rembrandt Gel Plus (a regimen of products consisting of a 10% carbamide peroxide gel, a whitening toothpaste, and a mouthrinse), and a placebo paste. Seventy subjects completed this parallel, single-blind, three-compartment, randomized clinical study. The subjects were balanced into two groups based on a minimal shade of A3 on the Vita shade guide and assigned a product. The duration of product usage was 1 hour twice daily for 2 weeks. Change in tooth color was measured by reflectance spectroscopy using a colorimeter. The readings were taken in the L*, a*, b* color space at the initiation, at 1 week, and at 2 weeks of the study. Calculation of color change (delta E) was performed using the color difference equation established by the Commission Internationale de L'Eclairage. Visual evaluation of shade changes was performed using the Vita shade guide. Results from this clinical study showed that Colgate Platinum was 77.7% more effective at tooth whitening after 1 week and 41.8% more effective after 2 weeks of treatment vs the Rembrandt regimen. Results showed that the Colgate product is significantly superior vs Rembrandt at increasing tooth whiteness (increase in delta E). Shade guide changes showed an overall improvement of 7.08 Vita tabs for the Colgate product and 5.12 Vita tabs for the Rembrandt regimen.

The current status of vital tooth whitening techniques.

PubMed

Blankenau, R; Goldstein, R E; Haywood, V B

1999-08-01

Tooth whitening of vital teeth continues to have a major impact on the practice of dentistry. The growing public interest in having whiter, brighter teeth is clearly evident in the advertisements from toothpaste manufacturers on "whitening" formulations of their products and by the number of individuals seeking whitening procedures from their dentists. In addition, new over-the-counter whitening products continue to emerge in a marketplace that cannot seem to get teeth white enough, bright enough, fast enough. What new products and procedures have evolved over the past decade to whiten teeth? Are they better, safer, faster, and more effective now? Are dentists meeting public demand for whiter teeth and is this quest having a positive or negative impact on the practice of dentistry or the patient's dental health? I posed these questions to a group of experts on whitening procedures to get their opinions and recommendations.

FATE OF FLUORIDE-INDUCED SUBAMELOBLASTIC CYSTS IN DEVELOPING HAMSTER MOLAR TOOTH GERMS

PubMed Central

Lyaruu, DM; Alberga, JMR; Kwee, NCH; Bervoets, TJM; Bronckers, ALJJ; DenBesten, PK

2016-01-01

White opacities and pits are developmental defects in enamel caused by high intake of fluoride (F) during amelogenesis. We tested the hypothesis that these enamel pits develop at locations where F induces the formation of sub-ameloblastic cysts. We followed the fate of these cysts during molar development over time. Mandibles from hamster pups injected with 20 mg NaF/kg at postnatal day 4 were excised from 1 h after injection till shortly after tooth eruption, 8 days later. Tissues were histologically processed and cysts located and measured. Cysts were formed at early secretory stage and transitional stage of amelogenesis and detected as early 1 h after injection. The number of cysts increased from 1 to almost 4 per molar during the first 16 h post-injection. The size of the cysts was about the same, i.e., 0.46±0.29 ×106 μm3 at 2hr and 0.50±0.35×106 μm3 at 16 h post-injection. By detachment of the ameloblasts the forming enamel surface below the cyst was cell-free the first 16 h post-injection. With time new ameloblasts repopulated and covered the enamel surface in the cystic area. Three days after injection all cysts had disappeared and the integrity of the ameloblastic layer restored. After eruption, white opaque areas with intact enamel surface were found occlusally at similar anatomical locations as late secretory stage cysts were seen pre-eruptively. We conclude that at this moderate F dose, the opaque sub-surface defects with intact surface enamel (white spots) are the consequence of the fluoride-induced cystic lesions formed earlier under the late secretory–transitional stage ameloblasts. PMID:21277565

Soricid response to coarse woody debris manipulations in Coastal Plain loblolly pine forests.

Treesearch

Kurtis R. Moseley; Audrey K. Owens; Steven B. Castleberry; W. Mark Ford; John C. Kilgo; Timothy S. McCay

2009-01-01

We assessed shrew (soricids) response to coarse woody debris (CWD) manipulations in managed upland loblolly pine (Pinus taeda) stands in the upper Coastal Plain of South Carolina over multiple years and...

Pneumocystosis in wild small mammals from California

USGS Publications Warehouse

Laakkonen, Juha; Fisher, Robert N.; Case, Ted J.

2001-01-01

Cyst forms of the opportunistic fungal parasite Pneumocystis carinii were found in the lungs of 34% of the desert shrew, Notiosorex crawfordi (n = 59), 13% of the ornate shrew, Sorex ornatus (n = 55), 6% of the dusky-footed wood rat, Neotoma fuscipes (n = 16), 2.5% of the California meadow vole,Microtus californicus (n = 40), and 50% of the California pocket mouse, Chaetodipus californicus (n= 2) caught from southern California between February 1998 and February 2000. Cysts were not found in any of the harvest mouse, Reithrodontomys megalotis (n = 21), California mouse,Peromyscus californicus (n = 20), brush mouse, Peromyscus boylii (n = 7) or deer mouse, Peromyscus maniculatus (n = 4) examined. All infections were mild; extrapulmonary infections were not observed. Other lung parasites detected were Hepatozoon sp./spp. from M. californicus andNotiosorex crawfordi, Chrysosporium sp. (Emmonsia) from M. californicus, and a nematode from S. ornatus.

Light Levels, Refractive Development, and Myopia – a Speculative Review

PubMed Central

Norton, Thomas T.; Siegwart, John T.

2013-01-01

Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree shrew) have found that light levels (similar to being in the shade outdoors) that are mildly elevated compared to indoor levels, slow form-deprivation myopia and (in chick and tree shrew) lens-induced myopia. Normal chicks raised in low light levels (50 lux) with a circadian light on/off cycle often develop spontaneous myopia. We propose a model in which the ambient illuminance levels produce a continuum of effects on normal refractive development and the response to myopiagenic stimuli such that low light levels favor myopia development and elevated levels are protective. Among possible mechanisms, elevation of retinal dopamine activity seems the most likely. Inputs from intrinsically-photosensitive retinal ganglion cells (ipRGCs) at elevated light levels may be involved, providing additional activation of retinal dopaminergic pathways. PMID:23680160

The taming of the shrew: batterers' constructions of their wives' narratives.

PubMed

Borochowitz, Dalit Yassour

2008-10-01

Constructing a life story is a need shared by all humans to give their lives meaning and coherence. This article explores some of the narrative devices that batterers use to achieve a sense of coherence when telling their stories and justifying their violent behavior. A central theme that emerged from these stories centered on the men's perception of their wives as the embodiment of their own emotions and inner world. Two narrative strategies were identified in this context: (a) The construction of a "couple narrative" that focused on an idealized marital relationship rather than "allowing" the wife her story and (b) constructing a story around the theme of "she's not the same woman I married," which portrays the wife as "a shrew" and the violence as an attempt to discipline her. The stories of 18 batterers were used for this analysis, and two narratives were used to illustrate these strategies.

Mammals of South America, Volume 1, Marsupials, Xenarthrans, Shrews, and Bats

USGS Publications Warehouse

Gardner, A.L.

2007-01-01

The vast terrain between Panama and Tierra del Fuego contains some of the world?s richest mammalian fauna, but until now it has lacked a comprehensive systematic reference to the identification, distribution, and taxonomy of its mammals. The first such book of its kind and the inaugural volume in a three-part series, Mammals of South America both summarizes existing information and encourages further research of the mammals indigenous to the region. Containing identification keys and brief descriptions of each order, family, and genus, the first volume of Mammals of South America covers marsupials, shrews, armadillos, sloths, anteaters, and bats. Species accounts include taxonomic descriptions, synonymies, keys to identification, distributions with maps and a gazetteer of marginal localities, lists of recognized subspecies, brief summaries of natural history information, and discussions of issues related to taxonomic interpretations. Highly anticipated and much needed, this book will be a landmark contribution to mammalogy, zoology, tropical biology, and conservation biology.

Body size variation of mammals in a fragmented, temperate rainforest.

PubMed

Lomolino, Mark V; Perault, David R

2007-08-01

Body size is perhaps the most important trait of an organism, affecting all of its physiological and ecological processes and, therefore, fundamentally influencing its ability to survive and reproduce in different environments, including those that have been modified by human activities. We tested the hypothesis that anthropogenic transformation of old-growth forest landscapes can result in significant intraspecific changes in body size of resident biotas. We collected data on five species of nonvolant mammals (common deer mouse[Peromyscus maniculatus], northwestern deer mouse[P. keeni], southern red-backed vole[Clethrionomys gapperi], montane shrew[Sorex monticolus], and Trowbridge's shrew[S. trowbridgii]) to test whether body size (mass and length) of these species varied across types of land cover (macrohabitats) and along elevational gradients of the fragmented, temperate rainforest of Olympic National Forest (Washington, U.S.A.). We measured 2168 and 1134 individuals for body mass and body length, respectively. Three species (P. keeni, S. monticolus, and S. trowbridgii) exhibited significantly different body size among macrohabitats: individuals from fragments were smaller than those in old-growth corridors and those in more extensive stands of old-growth forest. Body size of P. keeni was significantly correlated with elevation along corridors, peaking near the medial reaches of the corridors. The effects of anthropogenic transformations of this landscape of old-growth, temperate rainforest, although not universal among the five species, were significant and rapid-developing in just a few decades following tree harvests. Thus, anthropogenic fragmentation may influence not only the diversity, species composition, and densities of local biotas, but also one of the most fundamental and defining characteristics of native species-their body size.

Solar Radiation during Rewarming from Torpor in Elephant Shrews: Supplementation or Substitution of Endogenous Heat Production?

PubMed Central

Thompson, Michelle L.; Mzilikazi, Nomakwezi; Bennett, Nigel C.; McKechnie, Andrew E.

2015-01-01

Many small mammals bask in the sun during rewarming from heterothermy, but the implications of this behaviour for their energy balance remain little understood. Specifically, it remains unclear whether solar radiation supplements endogenous metabolic thermogenesis (i.e., rewarming occurs through the additive effects of internally-produced and external heat), or whether solar radiation reduces the energy required to rewarm by substituting (i.e, replacing) metabolic heat production. To address this question, we examined patterns of torpor and rewarming rates in eastern rock elephant shrews (Elephantulus myurus) housed in outdoor cages with access to either natural levels of solar radiation or levels that were experimentally reduced by means of shade cloth. We also tested whether acclimation to solar radiation availability was manifested via phenotypic flexibility in basal metabolic rate (BMR), non-shivering thermogenesis (NST) capacity and/or summit metabolism (Msum). Rewarming rates varied significantly among treatments, with elephant shrews experiencing natural solar radiation levels rewarming faster than conspecifics experiencing solar radiation levels equivalent to approximately 20% or 40% of natural levels. BMR differed significantly between individuals experiencing natural levels of solar radiation and conspecifics experiencing approximately 20% of natural levels, but no between-treatment difference was evident for NST capacity or Msum. The positive relationship between solar radiation availability and rewarming rate, together with the absence of acclimation in maximum non-shivering and total heat production capacities, suggests that under the conditions of this study solar radiation supplemented rather than substituted metabolic thermogenesis as a source of heat during rewarming from heterothermy. PMID:25853244

Solar radiation during rewarming from torpor in elephant shrews: supplementation or substitution of endogenous heat production?

PubMed

Thompson, Michelle L; Mzilikazi, Nomakwezi; Bennett, Nigel C; McKechnie, Andrew E

2015-01-01

Many small mammals bask in the sun during rewarming from heterothermy, but the implications of this behaviour for their energy balance remain little understood. Specifically, it remains unclear whether solar radiation supplements endogenous metabolic thermogenesis (i.e., rewarming occurs through the additive effects of internally-produced and external heat), or whether solar radiation reduces the energy required to rewarm by substituting (i.e, replacing) metabolic heat production. To address this question, we examined patterns of torpor and rewarming rates in eastern rock elephant shrews (Elephantulus myurus) housed in outdoor cages with access to either natural levels of solar radiation or levels that were experimentally reduced by means of shade cloth. We also tested whether acclimation to solar radiation availability was manifested via phenotypic flexibility in basal metabolic rate (BMR), non-shivering thermogenesis (NST) capacity and/or summit metabolism (Msum). Rewarming rates varied significantly among treatments, with elephant shrews experiencing natural solar radiation levels rewarming faster than conspecifics experiencing solar radiation levels equivalent to approximately 20% or 40% of natural levels. BMR differed significantly between individuals experiencing natural levels of solar radiation and conspecifics experiencing approximately 20% of natural levels, but no between-treatment difference was evident for NST capacity or Msum. The positive relationship between solar radiation availability and rewarming rate, together with the absence of acclimation in maximum non-shivering and total heat production capacities, suggests that under the conditions of this study solar radiation supplemented rather than substituted metabolic thermogenesis as a source of heat during rewarming from heterothermy.

The Asian house shrew Suncus murinus as a reservoir and source of human outbreaks of plague in Madagascar

PubMed Central

Rajerison, Minoarisoa; Telfer, Sandra; Savin, Cyril; Carniel, Elisabeth; Duplantier, Jean-Marc

2017-01-01

Identifying key reservoirs for zoonoses is crucial for understanding variation in incidence. Plague re-emerged in Mahajanga, Madagascar in the 1990s but there has been no confirmed case since 1999. Here we combine ecological and genetic data, from during and after the epidemics, with experimental infections to examine the role of the shrew Suncus murinus in the plague epidemiological cycle. The predominance of S. murinus captures during the epidemics, their carriage of the flea vector and their infection with Yersinia pestis suggest they played an important role in the maintenance and transmission of plague. S. murinus exhibit a high but variable resistance to experimental Y. pestis infections, providing evidence of its ability to act as a maintenance host. Genetic analyses of the strains isolated from various hosts were consistent with two partially-linked transmission cycles, with plague persisting within the S. murinus population, occasionally spilling over into the rat and human populations. The recent isolation from a rat in Mahajanga of a Y. pestis strain genetically close to shrew strains obtained during the epidemics reinforces this hypothesis and suggests circulation of plague continues. The observed decline in S. murinus and Xenopsylla cheopis since the epidemics appears to have decreased the frequency of spillover events to the more susceptible rats, which act as a source of infection for humans. Although this may explain the lack of confirmed human cases in recent years, the current circulation of plague within the city highlights the continuing health threat. PMID:29155827

Architectonic subdivisions of neocortex in the tree shrew (Tupaia belangeri)

PubMed Central

Wong, Peiyan; Kaas, Jon H.

2010-01-01

Tree shrews are small mammals that bear some semblance to squirrels, but are actually close relatives of primates. Thus, they have been extensively studied as a model for the early stages of primate evolution. In the present study, subdivisions of cortex were reconstructed from brain sections cut in the coronal, sagittal or horizontal planes, and processed for parvalbumin (PV), SMI-32 immunopositive neurofilament protein epitopes, vesicle glutamate transporter 2 (VGluT2), free ionic zinc, myelin, cytochrome oxidase (CO) and Nissl substance. These different procedures revealed similar boundaries between areas, suggesting the detection of functionally relevant borders and allowed a more precise demarcation of cortical areal boundaries. Primary cortical areas were most clearly revealed by the zinc stain, due to the poor staining of layer 4, as thalamocortical terminations lack free ionic zinc. Area 17 (V1) was especially prominent, as the broad layer 4 was nearly free of zinc stain. However, this feature was less pronounced in primary auditory and somatosensory, cortex. In primary sensory areas, thalamocortical terminations in layer 4 densely express VGluT2. Auditory cortex consists of two architectonically distinct subdivisions, a primary core region (Ac), surrounded by a belt region (Ab) that had a slightly less developed koniocellular appearance. Primary motor cortex (M1) was identified by the absence of VGluT2 staining in the poorly developed granular layer 4 and the presence of SMI-32 labeled pyramidal cells in layers 3 and 5. The presence of well-differentiated cortical areas in tree shrews indicates their usefulness in studies of cortical organization and function. PMID:19462403

Comparative morphology of the penis and clitoris in four species of moles (Talpidae)

PubMed Central

Sinclair, Adriane Watkins; Glickman, Stephen; Catania, Kenneth; Shinohara, Akio; Baskin, Lawrence; Cunha, Gerald R.

2017-01-01

The penile and clitorial anatomy of four species of Talpid moles (broad-footed, star-nosed, hairy-tailed, and Japanese shrew moles) were investigated to define penile and clitoral anatomy and to examine the relationship of the clitoral anatomy with the presence or absence of ovotestes. The ovotestis contains ovarian tissue and glandular tissue resembling fetal testicular tissue and can produce androgens. The ovotestis is present in star-nosed and hairy-tailed moles, but not in broad-footed and Japanese shrew moles. Using histology, 3D reconstruction, and morphometric analysis, sexual dimorphism was examined in regard to a nine feature masculine trait score that included perineal appendage length (prepuce), anogenital distance, and presence/absence of bone. The presence/absence of ovotestes was discordant in all four mole species for sex differentiation features. For many sex differentiation features, discordance with ovotestes was observed in at least one mole species. The degree of concordance with ovotestes was highest for hairy-tailed moles and lowest for broad-footed moles. In relationship to phylogenetic clade, sex differentiation features also did not correlate with the similarity/divergence of the features and presence/absence of ovotestes. Hairy-tailed and Japanese shrew moles reside in separated clades, but they exhibit a high degree of congruence. Broad-footed and hairy-tailed moles reside within the same clade but had one of the lowest correlations in features and presence/absence of ovotestes. Thus, phylogenetic affinity and the presence/absence of ovotestes are poor predictors for most sex differentiation features within mole external genitalia. PMID:28251823

OCT of early dental caries: a comparative study with histology and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Hewko, Mark D.; Choo-Smith, Lin-P'ing; Ko, Alex C.; Leonardi, Lorenzo; Dong, Cecilia C.; Cleghorn, Blaine; Sowa, Michael G.

2005-03-01

Early dental caries result from destruction of the tooth's outer mineral matrix by acid-forming bacteria found in dental plaques. Early caries begin as surface disruptions where minerals are leached from the teeth resulting in regions of decreased mineral matrix integrity. Visually, these early carious regions appear as white spots due to the higher backscattering of incident light. With age these areas may become stained by organic compounds. Optical coherence tomography (OCT) examination of human teeth demonstrates a difference in penetration depth of the OCT signal into the carious region in comparison with sound enamel. However, while OCT demonstrates a structural difference in the enamel in the region of the caries, this technique provides little insight into the source of this difference. Raman spectroscopy provides biochemical measures derived from hydroxyapatite within the enamel as well as information on the crystallinity of the enamel matrix. The differences in the biochemical and morphological features of early caries and intact sound enamel are compared. Histological thin sections confirm the observations by OCT morphological imaging while Raman spectroscopy allows for biochemical identification of carious regions by a non-destructive method. Visual examination and conventional radiographic imaging of the intact tooth are used in clinical assessment prior to optical measurements. The combination of OCT, Raman spectroscopy and thin section histology aid in determining the changes that give rise to the visual white spot lesions.

Associations of types of pain with crack-level, tooth-level and patient-level characteristics in posterior teeth with visible cracks: Findings from the National Dental Practice-Based Research Network.

PubMed

Hilton, Thomas J; Funkhouser, Ellen; Ferracane, Jack L; Gordan, Valeria V; Huff, Kevin D; Barna, Julie; Mungia, Rahma; Marker, Timothy; Gilbert, Gregg H

2018-03-01

The objective of this study was to determine which patient traits, behaviors, external tooth and/or crack characteristics correlate with the types of symptoms that teeth with visible cracks exhibit, namely pain on biting, pain due to cold stimuli, or spontaneous pain. Dentists in the National Dental Practice-Based Research Network enrolled a convenience sample of subjects each of whom had a single, vital posterior tooth with at least one observable external crack (cracked teeth); 2858 cracked teeth from 209 practitioners were enrolled. Data were collected at the patient-, tooth-, and crack-level. Generalized estimating equations were used to obtain significant (p < .05) independent odds ratios (OR) associated with teeth that were painful for 10 outcomes based on types of pain and combinations thereof. Overall, 45% of cracked teeth had one or more symptoms. Pain to cold was the most common symptom, which occurred in 37% of cracked teeth. Pain on biting (16%) and spontaneous pain (11%) were less common. Sixty-five percent of symptomatic cracked teeth had only one type of symptom, of these 78% were painful only to cold. No patient-, tooth- or crack-level characteristic was significantly associated with pain to cold alone. Positive associations for various combinations of pain symptoms were present with cracks that: (1) were on molars; (2) were in occlusion; (3) had a wear facet through enamel; (4) had caries; (5) were evident on a radiograph; (6) ran in more than one direction; (7) blocked transilluminated light; (8) connected with another crack; (9) extended onto the root; (10) extended in more than one direction; or (11) were on the distal surface. Persons who were <65 yo or who clench, grind, or press their teeth together also were more likely to have pain symptoms. Pain was less likely in teeth with stained cracks or exposed roots, or in non-Hispanic whites. Although pain to cold was the most commonly noted pain associated with symptomatic cracked teeth, no patient-, tooth- or crack-level characteristic was significantly associated with pain to cold alone. Characteristics were only associated with pain on biting and/or spontaneous pain with or without pain to cold. Although often considered the most reliable diagnosis for a cracked tooth, pain on biting is not the most common symptom of a tooth with a visible crack, but rather pain to cold. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dental Fear in Children with Repeated Tooth Injuries.

PubMed

Negovetić Vranić, Dubravka; Ivančić Jokić, Nataša; Bakarčić, Danko; Carek, Andreja; Rotim, Željko; Verzak, Željko

2016-06-01

Tooth injuries are serious clinical conditions. Some children experience dental trauma only once, while others are more prone to repeated tooth injuries. Repeated dental trauma occurs in 19.4% to 30% of patients. Pain and dental trauma are the most common reasons for fear and anxiety. The main objective of this study was to investigate how dental trauma, as well as repeated dental trauma affects the occurrence and development of dental fear in children. The study was conducted on a random sample of 147 subjects (88 boys and 59 girls) aged 5-8 and 9-12 years. Subjects in both age groups were divided into subroups without dental trauma, with one dental trauma and with repeated dental trauma. The validated Children’s Fear Survey Schedule – Dental Subscale was used on fear assessment. Results showed that only 12.2% of children without trauma, 33.3% with one trauma and 51.7% with repeated trauma were not afraid of injection. Older children had a significantly lower fear of injections, touch of an unknown person, choking, going to the hospital and people in white uniforms. Dentist was not the cause of fear in 65.5% of patients with repeated trauma. With each repeated injury of teeth, the degree of their fear of dental treatment was lower.

Impact of Bisphosphonate on Orthodontic tooth movement and osteoclastic count: An Animal Study.

PubMed

Venkataramana, V; Chidambaram, S; Reddy, B Vishnuvardhan; Goud, E V Soma Shekara; Arafath, Mohammed; Krishnan6, Santhana

2014-04-01

Background : The aim of the current study is to examine the effect of systemically administered BP-Pamidronate, on Orthodontic Tooth Movement (OTM) along with osteoclastic quantification in New Zealand white rabbits. Materials & Methods : Twenty rabbits used in the study, were equally divided into 2 groups ; Group-1 as Control & Group-2 as Experimental. A sentalloy NITI closed coil spring (GAC International, USA) of 100 gram force, ligated between the lower first molar and the anterior most incisors of the rabbit has served as orthodontic force element. The BP- Pamidronate was administered at the dosage of 1.5 mg/kg body intra-peritonially, on the 1st, 7th and 14th day of the experiment. On the 21st day both group of animals were sacrificed, mandibles were dissected. The formed diastema between the 1st and 2nd molar was measured on the dissected mandibles using standard metric scale, which is considered as the OTM in the mesial direction. Next, the alveolar bone regions along with intact mesial surfaces were processed for histological investigation (osteoclastic count). Results : The student 't' test has been done to compare the mean values of molar tooth movement and osteoclastic count. Parameter :1 molar tooth movement has shown a significant difference between the control (3.750 ± 0.548 mm) and the experimental group (3.050 ± 0.556 mm) with calculated 'p' value (p-value <0.05) is significant at 0.0110 level. Parameter : 2 osteoclastic count has shown a significant difference between the control (13.335000 ± 0.735856 per square mm.) and the experimental group (11.426900 ± 1.49369 per square mm) calculated 'p' value (p-value <0.05) is significant at 0.003 level. Conclusion : The molar tooth movement and the osteoclastic count were significantly reduced in BP - Pamidronate administered animals than non-drug recipients. How to cite the article: Venkataramana V, Chidambaram S, Reddy BV, Goud EV, Arafath M, Krishnan S. Impact of Bisphosphonate on Orthodontic tooth movement and olsteoclastic count: An Animal Study. J Int Oral Health 2014;6(2):1-8.

Impact of Bisphosphonate on Orthodontic tooth movement and osteoclastic count: An Animal Study

PubMed Central

Venkataramana, V; Chidambaram, S; Reddy, B Vishnuvardhan; Goud, E V Soma Shekara; Arafath, Mohammed; Krishnan, Santhana

2014-01-01

Background : The aim of the current study is to examine the effect of systemically administered BP-Pamidronate, on Orthodontic Tooth Movement (OTM) along with osteoclastic quantification in New Zealand white rabbits. Materials & Methods : Twenty rabbits used in the study, were equally divided into 2 groups ; Group-1 as Control & Group-2 as Experimental. A sentalloy NITI closed coil spring (GAC International, USA) of 100 gram force, ligated between the lower first molar and the anterior most incisors of the rabbit has served as orthodontic force element. The BP- Pamidronate was administered at the dosage of 1.5 mg/kg body intra-peritonially, on the 1st, 7th and 14th day of the experiment. On the 21st day both group of animals were sacrificed, mandibles were dissected. The formed diastema between the 1st and 2nd molar was measured on the dissected mandibles using standard metric scale, which is considered as the OTM in the mesial direction. Next, the alveolar bone regions along with intact mesial surfaces were processed for histological investigation (osteoclastic count). Results : The student ‘t’ test has been done to compare the mean values of molar tooth movement and osteoclastic count. Parameter :1 molar tooth movement has shown a significant difference between the control (3.750 ± 0.548 mm) and the experimental group (3.050 ± 0.556 mm) with calculated ‘p’ value (p-value <0.05) is significant at 0.0110 level. Parameter : 2 osteoclastic count has shown a significant difference between the control (13.335000 ± 0.735856 per square mm.) and the experimental group (11.426900 ± 1.49369 per square mm) calculated ‘p’ value (p-value <0.05) is significant at 0.003 level. Conclusion : The molar tooth movement and the osteoclastic count were significantly reduced in BP – Pamidronate administered animals than non-drug recipients. How to cite the article: Venkataramana V, Chidambaram S, Reddy BV, Goud EV, Arafath M, Krishnan S. Impact of Bisphosphonate on Orthodontic tooth movement and olsteoclastic count: An Animal Study. J Int Oral Health 2014;6(2):1-8. PMID:24876695

Small species indicate big changes? Arctic report card

USDA-ARS?s Scientific Manuscript database

As Arctic climate warms, how will terrestrial ecosystems and the communities that they support respond in the coming decades? Small mammals including shrews and their associated parasites can serve as key indicators and proxies of accelerating perturbation, contributing to general models for anticip...

Comparison of arch forms between Egyptian and North American white populations.

PubMed

Bayome, Mohamed; Sameshima, Glenn T; Kim, Yoonji; Nojima, Kunihiko; Baek, Seung-Hak; Kook, Yoon-Ah

2011-03-01

The aim of this study was to evaluate the morphologic differences in the mandibular arches of Egyptian and North American white subjects. The sample included 94 Egyptian subjects (35 Class I, 32 Class II, and 27 Class III) and 92 white subjects (37 Class I, 29 Class II, and 26 Class III). The subjects were grouped according to arch form types (tapered, ovoid, and square) to compare their frequency distribution between ethnic groups in each Angle classification. The most facial portions of 13 proximal contact areas were digitized on scanned images of mandibular casts to estimate the corresponding clinical bracket point for each tooth. Four linear and 2 proportional measurements were taken. In comparing arch dimensions, intermolar width was narrower in Egyptians than in the whites (P = 0.001). There was an even frequency distribution of the 3 arch forms in the Egyptian group. On the other hand, the most frequent arch form was ovoid followed by tapered and square in the white group; the square arch form was significantly less frequent than the tapered and ovoid arch forms (P = 0.029). The arch forms of Egyptians are narrower than those of whites. The distribution of the arch form types in Egyptians showed similar frequency, but the square arch form was less frequent in whites. It is recommended to select narrower archwires from the available variations to suit many Egyptian patients. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

All-optical photoacoustic imaging and detection of early-stage dental caries

NASA Astrophysics Data System (ADS)

Sampathkumar, Ashwin; Hughes, David A.; Longbottom, Chris; Kirk, Katherine J.

2015-02-01

Dental caries remain one of the most common oral diseases in the world. Current detection methods, such as dental explorer and X-ray radiography, suffer from poor sensitivity and specificity at the earliest (and reversible) stages of the disease because of the small size (< 100 microns) of early-stage lesions. We have developed a fine-resolution (480 nm), ultra-broadband (1 GHz), all-optical photoacoustic imaging (AOPAI) system to image and detect early stages of tooth decay. This AOPAI system provides a non-contact, non-invasive and non-ionizing means of detecting early-stage dental caries. Ex-vivo teeth exhibiting early-stage, white-spot lesions were imaged using AOPAI. Experimental scans targeted each early-stage lesion and a reference healthy enamel region. Photoacoustic (PA) signals were generated in the tooth using a 532-nm pulsed laser and the light-induced broadband ultrasound signal was detected at the surface of the tooth with an optical path-stabilized Michelson interferometer operating at 532 nm. The measured time-domain signal was spatially resolved and back-projected to form 2D and 3D maps of the lesion using k-wave reconstruction methods. Experimental data collected from areas of healthy and diseased enamel indicate that the lesion generated a larger PA response compared to healthy enamel. The PA-signal amplitude alone was able to detect a lesion on the surface of the tooth. However, time- reversal reconstructions of the PA scans also quantitatively depicted the depth of the lesion. 3D PA reconstruction of the diseased tooth indicated a sub-surface lesion at a depth of 0.6 mm, in addition to the surface lesion. These results suggest that our AOPAI system is well suited for rapid clinical assessment of early-stage dental caries. An overview of the AOPAI system, fine-resolution PA and histology results of diseased and healthy teeth will be presented.

Distributional records of shrews (Mammalia, Soricomorpha, Soricidae) from Northern Central America with the first record of Sorex from Honduras

USGS Publications Warehouse

Woodman, Neal; Matson, John O.; McCarthy, Timothy J.; Eckerlin, Ralph P.; Bulmer, Walter; Ordonez-Garza, Nicte

2012-01-01

Short term surveys for small mammals in Guatemala and Honduras during 1992–2009 provided important new records for 12 taxa of shrews from 24 localities. These locality records expand the known geographic distributions for five species and for the genus Sorex Linnaeus, 1758: the geographic range of Cryptotis goodwini Jackson, 1933, now includes the Sierra de las Minas, Guatemala, and several isolated highlands in western Honduras; the known distribution of Cryptotis mayensis (Merriam, 1901) is increased with the first definite modern record for this shrew from Guatemala; Cryptotis merriami Choate, 1970, is now known to occur in the Sierra de las Minas and the Sierra del Merendon, Guatemala, as well as the isolated Sierra de Omoa and Montana de La Muralla in Honduras, and its documented elevational range (600–1720 m) is expanded; records of Sorex veraepacis Alston, 1877, expand the known distribution of this species to include the Sierra de Yalijux, Guatemala; and discovery of Sorex salvini Merriam, 1897, at Celaque, Honduras (1825–3110 m), represents a considerable extension of the geographic range of the species, and it is the first record of the genus Sorex from Honduras. In addition, the first record of potential syntopy among C. goodwini, C merriami, and Cryptotis orophilus (J.A. Allen, 1895), is reported at an elevation of 1430 m in the Sierra de Celaque, Honduras. Information associated with these records contributes substantially to knowledge of habitat use, elevational distributions, reproductive patterns, diet, and parasites of the species encountered. General patterns include the first evidence that Neotropical species of soricids have smaller litters than their temperate congeners.

Acarine ectoparasites of Panti Forest Reserve in Johore, Malaysia

PubMed Central

Mariana, A; Mohd, Kulaimi B; Halimaton, I; Suhaili, ZA; Shahrul-Anuar, MS; Nor, Zalipah M; Ho, TM

2011-01-01

Objective To identify the presence of acarine ectoparasites and determine whether there is any potential public health risk in Panti Forest Reserve, Johore, Malaysia. Methods Trapping of animals and avifauna was conducted simultaneously along 5 expedition trails using 150 wire traps, 10 harp traps and 30 mist nets for 6 consecutive nights. A total of 140 animals consisting of 7 species of birds, 19 species of bats, 6 species of rodents and 1 species of tree-shrew as well as 8 myriapods were examined. Results Infestation rates of ticks, mesostigmatid mites and chiggers on animals examined were 24.3%, 28.6% and 27.9%, respectively. Infestation on bats was low (1.5%) and none occurred on birds. Majority of ticks extracted were at immature stages (78.9%). Genera of ticks on animals were Amblyomma, Dermacentor, Haemaphysalis and Ixodes. Ixodes granulatus was the only species of ticks identified from the animals. Examination of ticks under vegetation revealed 54% adults leading to identification of 3 species of ticks. A total of 7 species of mesostigmatid mites were found. 6 species were on rodent, Maxomys surifer and another one species, Laelaps nuttalli was found only on Leopoldamys sabanus. Laelaps sanguisugus was the only mesostigmatid found infesting tree-shrews. Seven genera of chiggers were identified. From this, 5 genera were on rodents, 4 genera on tree-shrews and 1 genus on a bat. Conclusions A total of 16 genera, 2 sub-genus and 14 species of acarine ectoparasites were found in this area. Findings of the survey demonstrate the presence of three spesies of acarine ectoparasites which have potential health risk i.e. Ixodes granulatus, Laelaps nuttalli and Leptotrombidium deliense. PMID:23569714

Wild rodents and shrews are natural hosts of Staphylococcus aureus.

PubMed

Mrochen, Daniel M; Schulz, Daniel; Fischer, Stefan; Jeske, Kathrin; El Gohary, Heba; Reil, Daniela; Imholt, Christian; Trübe, Patricia; Suchomel, Josef; Tricaud, Emilie; Jacob, Jens; Heroldová, Marta; Bröker, Barbara M; Strommenger, Birgit; Walther, Birgit; Ulrich, Rainer G; Holtfreter, Silva

2017-09-22

Laboratory mice are the most commonly used animal model for Staphylococcus aureus infection studies. We have previously shown that laboratory mice from global vendors are frequently colonized with S. aureus. Laboratory mice originate from wild house mice. Hence, we investigated whether wild rodents, including house mice, as well as shrews are naturally colonized with S. aureus and whether S. aureus adapts to the wild animal host. 295 animals of ten different species were caught in different locations over four years (2012-2015) in Germany, France and the Czech Republic. 45 animals were positive for S. aureus (15.3%). Three animals were co-colonized with two different isolates, resulting in 48 S. aureus isolates in total. Positive animals were found in Germany and the Czech Republic in each studied year. The S. aureus isolates belonged to ten different spa types, which grouped into six lineages (clonal complex (CC) 49, CC88, CC130, CC1956, sequence type (ST) 890, ST3033). CC49 isolates were most abundant (17/48, 35.4%), followed by CC1956 (14/48, 29.2%) and ST890 (9/48, 18.8%). The wild animal isolates lacked certain properties that are common among human isolates, e.g., a phage-encoded immune evasion cluster, superantigen genes on mobile genetic elements and antibiotic resistance genes, which suggests long-term adaptation to the wild animal host. One CC130 isolate contained the mecC gene, implying wild rodents might be both reservoir and vector for methicillin-resistant S. aureus. In conclusion, we demonstrated that wild rodents and shrews are naturally colonized with S. aureus, and that those S. aureus isolates show signs of host adaptation. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Gene expression signatures in tree shrew choroid in response to three myopiagenic conditions

PubMed Central

He, Li; Frost, Michael R.; Siegwart, John T.; Norton, Thomas T.

2014-01-01

We examined gene expression in tree shrew choroid in response to three different myopiagenic conditions: minus lens (ML) wear, form deprivation (FD), and continuous darkness (DK). Four groups of tree shrews (n = 7 per group) were used. Starting 24 days after normal eye opening (days of visual experience [DVE]), the ML group wore a monocular −5 D lens for 2 days. The FD group wore a monocular translucent diffuser for 2 days. The DK group experienced continuous darkness binocularly for 11 days, starting at 17 DVE. An age-matched normal group was examined at 26 DVE. Quantitative PCR was used to measure the relative (treated eye vs. control eye) differences in mRNA levels in the choroid for 77 candidate genes. Small myopic changes were observed in the treated eyes (relative to the control eyes) of the ML group (−1.0 ± 0.2 D; mean ± SEM) and FD group (−1.9 ± 0.2 D). A larger myopia developed in the DK group (−4.4 ± 1.0 D) relative to Normal eyes (both groups, mean of right and left eyes). In the ML group, 28 genes showed significant differential mRNA expression; eighteen were down-regulated. A very similar pattern occurred in the FD group; twenty-seven of the same genes were similarly regulated, along with five additional genes. Fewer expression differences in the DK group were significant compared to normal or the control eyes of the ML and FD groups, but the pattern was similar to that of the ML and FD differential expression patterns. These data suggest that, at the level of the choroid, the gene expression signatures produced by “GO” emmetropization signals are highly similar despite the different visual conditions. PMID:25072854

Mercury in soil, earthworms and organs of voles Myodes glareolus and shrew Sorex araneus in the vicinity of an industrial complex in Northwest Russia (Cherepovets).

PubMed

Komov, V T; Ivanova, E S; Poddubnaya, N Y; Gremyachikh, V A

2017-03-01

The characteristic properties of uptake and distribution of mercury in terrestrial ecosystems have received much lesser attention compared to aquatic particularly in Russia. Terrestrial ecosystems adjacent to large industrial manufactures-potential sources of mercury inflow into the environment frequently remain unstudied. This is the first report on mercury (Hg) levels in the basic elements of terrestrial ecosystems situated close to a large metallurgical complex.Mean values of mercury concentration (mg Hg/kg dry weight) in the vicinity of city of Cherepovets were the following: 0.056 ± 0.033-in the humus layer of soil; 0.556 ± 0.159-in earthworms; in the organs of voles Myodes glareolus (kidneys-0.021 ± 0.001; liver-0.014 ± 0.003; muscle-0.014 ± 0.001; brain-0.008 ± 0.002); in the organs of shrew Sorex araneus (kidneys-0.191 ± 0.016; liver-0.124 ± 0.011; muscle-0.108 ± 0.009; brain-0.065 ± 0.000). Correlation dependences between Hg content in soil and earthworms (r s  = 0.85, p < 0.01) as well as soil and all studied shrews' organs (rs = 0.44-0.58; p ≤ 0.01) were found.The results obtained evidence for a strong trophic link in the bioaccumulation of Hg in terrestrial food webs. Despite the vicinity to a large metallurgical complex, mercury content in the studied objects was significantly lower than values of corresponding parameters in the soils and biota from industrial (polluted) areas of Great Britain, the USA, and China.

Anandamide transport inhibition by ARN272 attenuates nausea-induced behaviour in rats, and vomiting in shrews (Suncus murinus)

PubMed Central

O'Brien, L D; Limebeer, C L; Rock, E M; Bottegoni, G; Piomelli, D; Parker, L A

2013-01-01

Background and Purpose To understand how anandamide transport inhibition impacts the regulation of nausea and vomiting and the receptor level mechanism of action involved. In light of recent characterization of an anandamide transporter, fatty acid amide hydrolase-1-like anandamide transporter, to provide behavioural support for anandamide cellular reuptake as a facilitated transport process. Experimental Approach The systemic administration of the anandamide transport inhibitor ARN272 ([(4-(5-(4-hydroxy-phenyl)-3,4-diaza-bicyclo[4.4.0]deca-1(6),2,4,7,9-pentaen-2-ylamino)-phenyl)-phenylamino-methanone]) was used to evaluate the prevention of LiCl-induced nausea-induced behaviour (conditioned gaping) in rats, and LiCl-induced emesis in shrews (Suncus murinus). The mechanism of how prolonging anandamide availability acts to regulate nausea in rats was explored by the antagonism of cannabinoid 1 (CB1) receptors with the systemic co-administration of SR141716. Key Results The systemic administration of ARN272 produced a dose-dependent suppression of nausea-induced conditioned gaping in rats, and produced a dose-dependent reduction of vomiting in shrews. The systemic co-administration of SR141716 with ARN272 (at 3.0 mg·kg−1) in rats produced a complete reversal of ARN272-suppressed gaping at 1.0 mg·kg−1. SR141716 alone did not differ from the vehicle solution. Conclusions and Implications These results suggest that anandamide transport inhibition by the compound ARN272 tonically activates CB1 receptors and as such produces a type of indirect agonism to regulate toxin-induced nausea and vomiting. The results also provide behavioural evidence in support of a facilitated transport mechanism used in the cellular reuptake of anandamide. PMID:23991698

Reproductive characteristics of the african pygmy hedgehog, atelerix albiventris.

PubMed

Bedford, J M; Mock, O B; Nagdas, S K; Winfrey, V P; Olson, G E

2000-09-01

To obtain further perspective on reproduction and particularly gamete function among so-called primitive mammals presently grouped in the Order Insectivora, we have examined the African hedgehog, Atelerix albiventris, in light of unusual features reported in shrews and moles. Atelerix proves to share many but not all of the characteristics seen in these other insectivores. The penis of Atelerix has a 'snail-like' form, but lacks the surface spines common in insectivores and a number of other mammals. Hedgehog spermatozoa display an eccentric insertion of the tail on the sperm head, and they manifest the barbs on the perforatorium that, in shrews, probably effect the initial binding of the sperm head to the zona pellucida. As a possible correlate, the structural matrix of the hedgehog acrosome comprises only two main components, as judged by immunoblotting, rather than the complex of peptides seen in the matrix of some higher mammals. The Fallopian tube of Atelerix is relatively simple; it displays only minor differences in width and in the arborized epithelium between the isthmus and ampulla, and shows no evidence of the unusual sperm crypts that characterize the isthmus or ampulla, depending on the species, in shrews and moles. In common with other insectivores, Atelerix appears to be an induced ovulator, as judged by the ovulation of some 6-8 eggs by about 23 h after injection of hCG. The dense cumulus oophorus appeared to have little matrix, in keeping with the modest dimensions of the tubal ampulla and, while it was not quite as discrete as that of soricids, it did show the same insensitivity to 0.5% (w/v) ovine or bovine hyaluronidase.

Introduction to Shakespeare: English.

ERIC Educational Resources Information Center

Hargraves, Richard

The "Introduction to Shakespeare" course in the Quinmester Program involves the careful study of the tragedy "Romeo and Juliet" and the comedy "The Taming of the Shrew," emphasizing language, development of character and theme. The course also includes the study of biographical data relevant to the evolution of…

Word Magic: Shakespeare's Rhetoric for Gifted Students.

ERIC Educational Resources Information Center

Kester, Ellen S.

Intended for teachers of gifted students in grades 4-12, the curriculum uses six of Shakespeare's comedies ("The Taming of the Shrew,""The Tempest,""Twelfth Night,""The Comedy of Errors,""As You Like It," and "A Midsummer Night's Dream") as materials for nurturing intellectual and…

Effect of coarse woody debris manipulation on soricid and herpetofaunal communities in upland pine stands of the southeastern coastal plain.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Justin, Charles

2009-04-01

Abstract -The majority of studies investigating the importance of coarse woody debris (CWD) to forest- floor vertebrates have taken place in the Pacific Northwest and southern Appalachian Mountains, while comparative studies in the southeastern Coastal Plain are lacking. My study was a continuation of a long-term project investigating the importance of CWD as a habitat component for shrew and herpetofaunal communities within managed pine stands in the southeastern Coastal Plain. Results suggest that addition of CWD can increase abundance of southeastern and southern short-tailed shrews. However, downed wood does not appear to be a critical habitat component for amphibians andmore » reptiles. Rising petroleum costs and advances in wood utilization technology have resulted in an emerging biofuels market with potential to decrease CWD volumes left in forests following timber harvests. Therefore, forest managers must understand the value of CWD as an ecosystem component to maintain economically productive forests while conserving biological diversity.« less

Phylogeography and recolonization of the Swiss Alps by the Valais shrew (Sorex antinorii), inferred with autosomal and sex-specific markers.

PubMed

Yannic, G; Basset, P; Hausser, J

2008-09-01

Using one male-inherited, one female-inherited and eight biparentally inherited markers, we investigate the population genetic structure of the Valais shrew (Sorex antinorii) in the Swiss Alps. Bayesian analysis on autosomal microsatellites suggests a clear genetic differentiation between two groups of populations. This geographically based structure is consistent with two separate postglacial recolonization routes of the species into Switzerland from Italian refugia after the last Pleistocene glaciations. Sex-specific markers also confirm genetic structuring among western and eastern areas, since very few haplotypes for either Y chromosome or mtDNA genome are shared between the two regions. Overall, these results suggest that two already well-differentiated genetic lineages colonized the Swiss Alps and came into secondary contact in the Rhône Valley. Low level of admixture between the two lineages is likely explained by the mountainous landscape structure of lateral valleys orthogonal to the main Rhône valley.

Effect of Photo-Fenton Bleaching on Tetracycline-stained Dentin in vitro.

PubMed

Bennett, Zackary Yale; Walsh, Laurence James

2015-02-01

Tetracycline-stained tooth structure is difficult to bleach using nightguard tray methods. The possible benefits of in-office light-accelerated bleaching systems based on the photo-Fenton reaction are of interest as possible adjunctive treatments. This study was a proof of concept for possible benefits of this approach, using dentine slabs from human tooth roots stained in a reproducible manner with the tetracycline antibiotic demeclocycline hydrochloride. Color changes overtime in tetra-cycline stained roots from single rooted teeth treated using gel (Zoom! WhiteSpeed(®)) alone, blue LED light alone, or gel plus light in combination were tracked using standardized digital photography. Controls received no treatment. Changes in color channel data were tracked overtime, for each treatment group (N = 20 per group). Dentin was lighter after bleaching, with significant improvements in the dentin color for the blue channel (yellow shade) followed by the green channel and luminosity. The greatest changes occurred with gel activated by light (p < 0.0001), which was superior to effects seen with gel alone. Use of the light alone did not significantly alter shade. This proof of concept study demonstrates that bleaching using the photo-Fenton chemistry is capable of lightening tetracycline-stained dentine. Further investigation of the use of this method for treating tetracycline-stained teeth in clinical settings appears warranted. Because tetracycline staining may respond to bleaching treatments based on the photo-Fenton reaction, systems, such as Zoom! WhiteSpeed, may have benefits as adjuncts to home bleaching for patients with tetracycline-staining.

Petroscirtes pylei, a new saber-toothed blenny from the Fiji Islands (Teleostei: Blenniidae)

USGS Publications Warehouse

Smith-Vaniz, W.F.

2005-01-01

Petroscirtes pylei is described from three specimens, 20.3-40.9 mm SL, obtained from a deep-water reef off Suva, Viti Levu, Fiji Islands. It is distinguished from all other congeners by its color pattern, including the presence of two dark body stripes, the lower one broadly extending onto the anal fin, and the dorsal fin with a broad, dark basal stripe, superimposed by a conspicuous white spot centered on the 4th spine. Among Petroscirtes, only the new species and P. springeri typically have 12 dorsal-fin spines but they are not closely related. The holotype was collected in 104-110 m, the second deepest depth record for a species of Petroscirtes. Discovery of this new species, and an apparently second new deep-water Petroscrites (uncollected), at a different Fijian reef indicates that our knowledge of the biodiversity of this habitat and of the saber-toothed blennies is very incomplete. Copyright ?? 2005 Magnolia Press.

Radiographic bone fill following debridement of a periodontal abscess. A case report.

PubMed

Khocht, A; Faldu, M G

1998-01-01

A periodontal abscess often develops in association with deepened periodontal pockets. Traditional management is by establishing drainage and prescribing antibiotics. This is usually followed by surgical pocket reduction. This case report discusses the remarkable healing of a periodontal abscess by establishing drainage alone without resorting to surgical pocket reduction. A 42-year-old white male presented with swollen gingivae associated with the mesiolingual of tooth #23. Increased probing depth and suppuration were evident. Radiographic bone loss on mesial #23 was present. A diagnosis of periodontal abscess was established. The abscess was drained through the orifice of the pocket. The patient failed to return for follow-up as instructed. A year later, the patient came back. Clinical evaluation showed healthy gingival tissues with probing depth of 3 mm on the mesiolingual of tooth #23. Radiographic evaluation showed bone fill of the osseous defect on the mesial of #23. The results of this case suggest that sufficient time should be allowed for healing prior to surgical pocket reduction.

Elastic band causing exfoliation of the upper permanent central incisors.

PubMed

Alves, Monica Ghislaine Oliveira; Kitakawa, Dárcio; Becker, Joao Batista Macedo; Brandão, Adriana Aigotti Haberbeck; Cabral, Luiz Antonio Guimarães; Almeida, Janete Dias

2015-01-01

Objective. This study reports a case in which elastic band use culminated in the loss of the incisors. Case Report. An 11-year-old white girl was seen complaining of pain, with purulent discharge and severe tooth mobility. The bone destruction detected radiographically in the region, despite its single location and absence in posterior quadrants of the maxilla and/or mandible, was similar to that observed in Langerhans cell disease. To our surprise, an elastic band involving the midportion of the roots of the two upper central incisors was found during biopsy. The debris was removed and a metal wire was placed in permanent maxillary right and left incisors. The patient was followed up, but no improvement in tooth mobility was observed. Bone loss increased, and internal resorption and root exposure occurred, which culminated in the extraction of permanent maxillary right and left incisors. Conclusion. The present case highlights the fact that professionals sometimes are confronted by anamnestic reports never seen before.

Dental fragment embedded in the lower lip after facial trauma: Brief review literature and report of a case

PubMed Central

Lauritano, Dorina; Petruzzi, Massimo; Sacco, Gerardo; Campus, Guglielmo; Carinci, Francesco; Milillo, Lucio

2012-01-01

Upper incisors are the most frequently involved teeth in traumatic dental injuries. Soft tissues (lips and/or oral mucosa) adjacent to incisal edge can receive direct and/or indirect traumas. Laceration of the lower lip is a not rare eventuality and teeth fragments could be embedded in labial soft tissue. The reattachment of these fragments, if possible, is the elective treatment choice, thanks to the modern adhesive and restorative techniques. The authors present a case of a white Caucasian 10-year-old child, who attended the dental clinic for the treatment of both upper central incisors’ crown fractures. The fragment of the left incisor was retrieved embedded in the lower lip. It was successfully surgically removed and reattached using a composite adhesive technique. A careful clinical and radiographic examination with the surgical removal of tooth fragments could prevent undesirable foreign body reaction, infection and scarring. The authors also reviewed the most relevant literature concerning tooth fragment reattachment after removal from oral soft tissues. PMID:23814592

Biological monitors of pollution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Root, M.

1990-02-01

This article discusses the use of biological monitors to assess the biological consequences of toxicants in the environment, such as bioavailability, synergism, and bioaccumulation through the food web. Among the organisms discussed are fly larvae, worms, bees, shellfish, fishes, birds (starlings, owls, hawks, songbirds) and mammals (rabbits, field mice, shrews).

Metal contamination in wildlife living near two zinc smelters

USGS Publications Warehouse

Beyer, W.N.; Pattee, O.H.; Sileo, L.; Hoffman, D.J.; Mulhern, B.M.

1985-01-01

Wildlife in an oak forest on Blue Mountain was studied 10 km upwind (Bake Oven Knob site) and 2 km downwind (Palmerton site) of two zinc smelters in eastern Pennsylvania, USA. Previous studies at sites near these smelters had shown changes in populations of soil microflora, lichens, green plants and litter-inhabiting arthropods. The 02 soil litter horizon at Palmerton was heavily contaminated with Pb (2700 mg kg-1), Zn (24000 mg kg-1), and Cd (710 mg kg-1), and to a lesser extent with Cu (440 mg kg-1). Various kinds of invertebrates (earthworms, slugs and millipedes) that feed on soil litter or soil organic matter were rare at, or absent from, the Palmerton site. Those collected at Bake Oven Knob tended to have much higher concentrations of metals than did other invertebrates. Frogs, toads and salamanders were very rare at, or absent from, the Palmerton site, but were present at Bake Oven Knob and at other sites on Blue Mountain farther from the smelters. Metal concentrations (dry wt) in different organisms from Palmerton were compared. Concentrations of Pb were highest in shrews (110 mg kg-1), followed by songbirds (56 mg kg-1), leaves (21 mg kg-1), mice (17 mg kg-1), carrion insects (14 mg kg-1), berries (4.0 mg kg-1), moths (4,3 mg kg-1) and fungi (3.7 mg kg-1). Concentrations of Cd, in contrast, were highest in carrion insects (25 mg kg-1 ),followed by fungi (9.8 mg kg-1), leaves (8.1 mg kg-1), shrews (7.3 mg kg-I), moths (4.9 mg kg-1), mice (2.6 mg kg -1), songbirds (2.5 mg kg -1) and berries (1.2 mg kg-1). Concentrations of Zn and Cu tended to be highest in the same organisms that had the highest concentrations of Cd. Only a small proportion of the metals in the soil became incorporated into plant foliage, and much of the metal contamination detected in the biota probably came from aerial deposition. The mice from both sites seemed to be healthy. Shrews had higher concentrations of metals than did mice, and one shrew showed evidence of Pb poisoning; its red blood cell ALAD activity was greatly reduced, one kidney contained acid-fast intranuclear inclusion bodies, and the other kidney had 280 mg kg-1 Pb (wet wt). The livers from two cuckoos from Palmerton had elevated Pb concentrations (18 and 25 mg kg-1, wet wt). Most of the songbirds seemed to be healthy.

Maternal and early life factors of tooth emergence patterns and number of teeth at one and two years of age

PubMed Central

Ntani, Georgia; Day, Peter F; Baird, Janis; Godfrey, Keith M; Robinson, Sian M; Cooper, Cyrus; Inskip, Hazel M

2015-01-01

Various environmental factors have been associated with the timing of eruption of primary dentition, but the evidence to date comes from small studies with limited information on potential risk factors. We aimed to investigate associations between tooth emergence patterns and pre-conception, pregnancy and post-natal influences. Dentition patterns were recorded at ages one and two years in 2,915 children born to women in the Southampton Women’s Survey from whom information had been collected on maternal factors before conception and during pregnancy. In mutually adjusted regression models we found that: children were more dentally advanced at ages one and two years if their mothers had smoked during pregnancy or they were longer at birth; mothers of children whose dental development was advanced at age two years tended to have poorer socioeconomic circumstances, and to have reported a slower walking speed pre-pregnancy; and children of mothers of Asian ethnicity had later tooth development than those of white mothers. The findings add to the evidence of environmental impacts on the timing of the eruption of primary dentition in indicating that maternal smoking during pregnancy, socio-economic status and physical activity (assessed by reported walking speed) may influence the child’s primary dentition. Early life factors, including size at birth are also associated with dentition patterns, as is maternal ethnicity. PMID:25936832

Effect of various tooth-whitening products on enamel microhardness.

PubMed

Grobler, S R; Majeed, A; Moola, M H

2009-11-01

The purpose of this in vitro study was to evaluate the effect of various tooth-whitening products containing carbamide peroxide (CP) or hydrogen peroxide (HP), on enamel microhardness. Enamel blocks were exposed to: Nite White ACP 10% CP (Group 2, n=10); Yotuel Patient 10% CP (Group 3, n=10); Opalescence PF 10% CP (Group 4, n=10); Opalescence PF 20% CP (Group 5, n=10); Opalescence Treswhite Supreme 10% HP (Group 6, n=10); Yotuel 10 Minutes 30% CP (Group 7, n=10); Opalescence Quick 45% CP (Group 8, n=10), Yotuel Special 35% HP (Group 9, n=10), Opalescence Boost 38% HP (Group 10, n=10) according to the instructions of the manufacturers. The control (Group 1, n=10) was enamel blocks kept in artificial saliva at 37 degrees C without any treatment. The microhardness values were obtained before exposure and after a 14-day treatment period. Specimens were kept in artificial saliva at 37 degrees C between treatments. Data were analysed using Kruskal-Wallis one-way ANOVA and Tukey-Kramer Multiple Comparison Test. Indent marks on the enamel blocks were also examined under the Scanning Electron Microscope. All whitening products decreased enamel microhardness except group 10 but only Groups 2, 3, 4, 5 and 7 showed significant decrease in enamel microhardness as compared to the control group (p < 0.05). Groups 2, 3 and 7 differed significantly from all the other groups (p < 0.05). The highest damage was recorded for Group 2 (Nite White ACP 10% CP), which differed significantly from Groups 3 and 7. SEM images also showed damage to enamel. All products tested in this study decreased enamel microhardness except Opalescence Boost 38% HP. The products containing carbamide peroxide were more damaging to enamel because of the longer application times. Nite White ACP 10% CP showed the highest reduction in enamel microhardness as compared to other products tested.

Is dolphin morbillivirus virulent for white-beaked dolphins (Lagenorhynchus albirostris)?

PubMed

van Elk, C E; van de Bildt, M W G; Jauniaux, T; Hiemstra, S; van Run, P R W A; Foster, G; Meerbeek, J; Osterhaus, A D M E; Kuiken, T

2014-11-01

The virulence of morbilliviruses for toothed whales (odontocetes) appears to differ according to host species. In 4 species of odontocetes, morbilliviruses are highly virulent, causing large-scale epizootics with high mortality. In 8 other species of odontocetes, including white-beaked dolphins (Lagenorhynchus albirostris), morbilliviruses have been found as an incidental infection. In these species, the virulence of morbilliviruses is not clear. Therefore, the admission of 2 white-beaked dolphins with morbillivirus infection into a rehabilitation center provided a unique opportunity to investigate the virulence of morbillivirus in this species. By phylogenetic analysis, the morbilliviruses in both animals were identified as a dolphin morbillivirus (DMV) most closely related to that detected in a white-beaked dolphin in Germany in 2007. Both animals were examined clinically and pathologically. Case No. 1 had a chronic neural DMV infection, characterized by polioencephalitis in the cerebrum and morbillivirus antigen expression limited to neurons and glial cells. Surprisingly, no nervous signs were observed in this animal during the 6 months before death. Case No. 2 had a subacute systemic DMV infection, characterized by interstitial pneumonia, leucopenia, lymphoid depletion, and DMV antigen expression in mononuclear cells and syncytia in the lung and in mononuclear cells in multiple lymphoid organs. Cause of death was not attributed to DMV infection in either animal. DMV was not detected in 2 contemporaneously stranded white-beaked dolphins. Stranding rate did not increase in the region. These results suggest that DMV is not highly virulent for white-beaked dolphins. © The Author(s) 2013.

Characterization of Candidatus Bartonella ancashi: A Novel Human Pathogen Associated with Carrins Disease

DTIC Science & Technology

2015-03-12

12 Endocarditis ...Reservoir Human Disease Year Recognized Reference B. alsatica Rabbits Lymphadenitis and Endocarditis 1999 (5; 100; 198) B. acomydis Mice 2013...132) B. coopersplainsensis Rats 2009 (97) B. doshiae Voles 1995 (23) B. elizabethae Rats Endocarditis 1993 (57) B. florencae Shrews 2013

Rickettsia felis in Xenopsylla cheopis, Java, Indonesia

PubMed Central

Jiang, Ju; Soeatmadji, Djoko W.; Henry, Katherine M.; Ratiwayanto, Sutanti; Bangs, Michael J.

2006-01-01

Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas. PMID:16965716

TOXICITY EVALUATION OF 1,3,5-TRINITROBENZENE (TNB) IN SHREWS (CRYPTOTIS PARVA)

EPA Science Inventory

TNB has been detected as an environmental contaminant of soil and water at certain Army installations and production waste disposal sites. At present there are no toxicity data on TNB in small wild mammals that might be used for ecological risk assessment. Therefore, a 14-day to...

Knowledge and attitude of some nigerian school teachers on the emergency management of avulsed permanent incisor.

PubMed

Olatosi, O O; Iwuala, S O; Isiekwe, G I; Oredugba, F A; Adenaike, A S; Oluwo, A O

2013-01-01

Tooth avulsion has been known to be the most severe of all dental injuries. The immediate action taken at the accident site will determine the prognosis of the tooth. Replantation of an avulsed tooth is the treatment of choice. To assess the knowledge and attitude of primary and secondary (Basic educational) school teachers on the emergency management of avulsed permanent incisors. Twenty public and private basic educational schools were randomly selected from Lagos State. Descriptive cross-sectional study. A 23 item self administered questionnaire was distributed to teachers to determine their knowledge and attitude on the emergency management of avulsed permanent incisors. Data was analysed using SPSS (Statistical Package for Social Sciences), Version 21.0. The responses obtained were tabulated and expressed as frequency distributions and then computed in percentages. Chi-square was used to test the association between knowledge of the schools teachers regarding the emergency management of avulsed permanent incisors and their socio-demographic variables. Multivariate analysis was used to adjust for confounding variables. The level of significance was set at P ≤0.05. A total of 320 teachers answered the questionnaires. Most of the teachers were female (63.1%). Only (30.9%) had received first aid training which included emergency management of dental trauma. Forty- two percent (134) didn't know that an avulsed permanent tooth could be replanted. Twenty teachers (44.4%) would clean an avulsed tooth with toothbrush and toothpaste. A greater proportion of the respondents 130 (40.6%) would transport an avulsed tooth using a clean white handkerchief. The overall knowledge of the school teachers was poor (84%).There was a statistically significant association between the knowledge of the school teachers and the inclusion of emergency management of dental trauma in the first aid training of the teachers P=0.05. Predictors of teachers' level of knowledge of emergency management of avulsed teeth were receipt of advise on management of traumatic dental injuries (OR= 2.5, CI=1.19-4.28) and type of school (OR=0.93, CI=0.206-0.750). The school teachers had insufficient knowledge about the emergency management of avulsed permanent teeth. School oral health campaigns with regards to emergency management of avulsed teeth will help improve teachers' knowledge and modify their behaviour.

The potential for dental plaque to protect against erosion using an in vivo-in vitro model--a pilot study.

PubMed

Cheung, A; Zid, Z; Hunt, D; McIntyre, J

2005-12-01

Tooth erosion is a problem for professional wine tasters (exogenous erosion from frequent exposure to wine acids) and for people with gastro oesophageal reflux disease (GORD) and bulimia who experience frequent reflux of gastric contents into the mouth (endogenous erosion from mainly HCl). The objective in this study was to determine whether plaque/pellicle could provide teeth with any protection from two common erosive acids, using an in vivo-in vitro technique. Tiles of human tooth enamel and root surfaces were prepared from six extracted, unerupted third molar teeth and sterilized. Mandibular stents were prepared for six volunteer subjects and the tiles bonded to the buccal flanges of these stents. They were worn initially for three days to permit a layer of pellicle and plaque to form over the tile surfaces, and for a further 10 days of experimentation. Following cleaning of the plaque/ pellicle layer from the tiles on the right side flange, all the tiles were submerged in either 0.06M HCl or white wine for an accumulated time of 600 and 1500 minutes, respectively. Depths of erosion were determined using light microscopy of sections of the enamel and root tiles. SEM of the lesion surfaces was carried out to investigate the nature of erosive damage and of plaque/pellicle remnants. Retained plaque was found to significantly inhibit dental erosion on enamel, from contact with both HCl and wine, compared with that resulting following its removal. However, it was found to provide no significant protection on root surfaces. SEM analysis of the tile surfaces revealed marked etching of enamel on the cleaned surfaces, and considerable alteration to the appearance of remaining plaque and pellicle on most surfaces. Within the limitations of numbers of specimens, dental plaque/pellicle provided a significant level of protection to tooth enamel against dental erosion from simulated gastric acids and from white wine, using an in vivo-in vitro model. It was unable to provide any significant protection to root surfaces from these erosive agents. Possible reasons for this difference are explored.

Skeletal injuries in small mammals: a multispecies assessment of prevalence and location

USGS Publications Warehouse

Stephens, Ryan B.; Burke, Christopher B.; Woodman, Neal; Poland, Lily B.; Rowe, Rebecca J.

2018-01-01

Wild mammals are known to survive injuries that result in skeletal abnormalities. Quantifying and comparing skeletal injuries among species can provide insight into the factors that cause skeletal injuries and enable survival following an injury. We documented the prevalence and location of structural bone abnormalities in a community of 7 small mammal species inhabiting the White Mountains of New Hampshire. These species differ in locomotion type and levels of intraspecific aggression. Overall, the majority of injuries were to the ribs or caudal vertebrae. Incidence of skeletal injuries was highest in older animals, indicating that injuries accumulate over a lifetime. Compared to species with ambulatory locomotion, those with more specialized (semi-fossorial, saltatorial, and scansorial) locomotion exhibited fewer skeletal abnormalities in the arms and legs, which we hypothesize is a result of a lesser ability to survive limb injuries. Patterns of skeletal injuries in shrews (Soricidae) were consistent with intraspecific aggression, particularly in males, whereas skeletal injuries in rodents (Rodentia) were more likely accidental or resulting from interactions with predators. Our results demonstrate that both the incidence and pattern of skeletal injuries vary by species and suggest that the ability of an individual to survive a specific skeletal injury depends on its severity and location as well as the locomotor mode of the species involved.

Conspicuous impacts of inconspicuous hosts on the Lyme disease epidemic.

PubMed

Brisson, Dustin; Dykhuizen, Daniel E; Ostfeld, Richard S

2008-01-22

Emerging zoonotic pathogens are a constant threat to human health throughout the world. Control strategies to protect public health regularly fail, due in part to the tendency to focus on a single host species assumed to be the primary reservoir for a pathogen. Here, we present evidence that a diverse set of species can play an important role in determining disease risk to humans using Lyme disease as a model. Host-targeted public health strategies to control the Lyme disease epidemic in North America have focused on interrupting Borrelia burgdorferi sensu stricto (ss) transmission between blacklegged ticks and the putative dominant reservoir species, white-footed mice. However, B. burgdorferi ss infects more than a dozen vertebrate species, any of which could transmit the pathogen to feeding ticks and increase the density of infected ticks and Lyme disease risk. Using genetic and ecological data, we demonstrate that mice are neither the primary host for ticks nor the primary reservoir for B. burgdorferi ss, feeding 10% of all ticks and 25% of B. burgdorferi-infected ticks. Inconspicuous shrews feed 35% of all ticks and 55% of infected ticks. Because several important host species influence Lyme disease risk, interventions directed at a multiple host species will be required to control this epidemic.

Esthetic Outcomes of Immediately Loaded Locking Taper Implants in the Anterior Maxilla: A Case Series Study.

PubMed

Lombardo, Giorgio; Corrocher, Giovanni; Pighi, Jacopo; Mascellaro, Anna; Marincola, Mauro; Nocini, Per Francesco

2016-06-01

The purpose of this study was to evaluate the esthetic outcome of single-tooth locking taper connection implants placed in the anterior maxilla following a postextractive nonfunctional loading protocol. This preliminary clinical study involving 16 patients evaluated the results of 21 implants placed in areas with high esthetic value. For each implant the pink esthetic score, white esthetic score, cumulative survival rate, and health status of peri-implant tissues were evaluated. The cumulative survival rate was 100% 2 years after prosthetic loading, and the mean total pink esthetic score/white esthetic score was 16.9 ± 1.14 on a maximum value of 20. There was excellent plaque control in all patients, and inflammation indices were within the norm. Within the limits of this study, this immediate nonfunctional loading protocol seems to be a successful procedure esthetically and for the maintenance of peri-implant soft tissues.

The effect of three whitening oral rinses on enamel micro-hardness.

PubMed

Potgieter, E; Osman, Y; Grobler, S R

2014-05-01

The purpose of this study was to determine the effect on human enamel micro-hardness of three over-the-counter whitening oral rinses available in South Africa. Enamel fragments were gathered into three groups of 15 each. One group was exposed to Colgate Plax Whitening Blancheur, the second group to White Glo 2 in 1 and the third to Plus White, in each case for periods recommended by the respective manufacturers. Surface micro-hardness of all groups was measured before and after a 14 day treatment period. pH levels of the oral rinses were also determined with a combination pH electrode. Pre- and post- treatment data were analysed by the Wilcoxon Signed Rank Sum Test. According to the micro-hardness values no significant (p > 0.05) enamel damage was found as a result of treatment. However, it was observed that Colgate Pax and White Glo decreased the enamel hardness, an early sign of enamel damage, while Plus White showed a small increase in hardness. The three whitening oral rinses on the South African market do not damage the tooth enamel significantly when used as recommended by the manufacturers. However, extending the contact period and increasing the frequency of application might lead to damage of enamel.

77 FR 40705 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Buena Vista...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

... from strictly morphological measurements for this group did not clarify distribution of the various... of mitochondrial DNA, that the shrew occurrences in the Tulare Basin group together with the Buena... litter containing four to six young. Within a population, the number of litters produced per year depends...

Propelling Students into Active Grammar Participation

ERIC Educational Resources Information Center

Jurhill, Dennis A.

2011-01-01

"O! this learning, what a thing it is." -W. Shakespeare, "The Taming of the Shrew." The aim of this action research was to find out if active grammar involvement amongst students might lead to better results. My approach was to activate my students during grammar instruction by using cooperative learning: that is a form of…

The Importance of Perceived Control: Fact or Fantasy?

DTIC Science & Technology

1977-01-01

thus Shakespeare’s com- ment in Taming of the Shrew that “there’s small choice in rotten apples” requires further commentary. Let’s turn now to......Maryland Destroy this report when no longer needed. Do not return it to the originator. The findings in this report are not to be construed as an

Reproduction, Contestation, and Political Theater: Reflections on Three Productions.

ERIC Educational Resources Information Center

Shirley, Dennis

1986-01-01

Considers the potential of political theater to raise questions of social justice in a provocative manner for students. Describes three productions at a Swiss boarding school, in which the author served as director: a feminist "Taming of the Shrew," a student-written satirical cabaret, and Brecht's "The Good Person of Sezuan."…

Patterns of morphological variation amongst semifossorial shrews in the highlands of Guatemala, with the description of a new species (Mammalia, Soricomorpha, Soricidae)

USGS Publications Warehouse

Woodman, Neal

2011-01-01

Members of the Cryptotis goldmani group of small-eared shrews (Mammalia, Soricomorpha, Soricidae) represent a clade within the genus that is characterized by modifications of the forelimb that include broadened forefeet, elongated and broadened foreclaws, and massive humeri with enlarged processes. These modifications are consistent with greater adaptation to their semifossorial habits than other members of the genus. The species in this group occur discontinuously in temperate highlands from southern Tamaulipas, Mexico, to Honduras. In Guatemala, there are three species: the relatively widespread Cryptotis goodwini and two species (Cryptotis lacertosus, Cryptotis mam) endemic to highland forests in the Sierra de los Cuchumatanes of western Guatemala. Ongoing studies focusing on the relationships of variation in cranial and postcranial skeletal morphology have revealed a fourth species from remnant cloud forest in the Sierra de Yalijux, central Guatemala. In this paper, I describe this new species and characterize its morphology relative to other species in the C. goldmani group and to other species of Cryptotis in Guatemala. In addition, I summarize available details of its habitat and ecology.

Astrocytic and neuronal oxidative metabolism are coupled to the rate of glutamate-glutamine cycle in the tree shrew visual cortex.

PubMed

Sonnay, Sarah; Poirot, Jordan; Just, Nathalie; Clerc, Anne-Catherine; Gruetter, Rolf; Rainer, Gregor; Duarte, João M N

2018-03-01

Astrocytes play an important role in glutamatergic neurotransmission, namely by clearing synaptic glutamate and converting it into glutamine that is transferred back to neurons. The rate of this glutamate-glutamine cycle (V NT ) has been proposed to couple to that of glucose utilization and of neuronal tricarboxylic acid (TCA) cycle. In this study, we tested the hypothesis that glutamatergic neurotransmission is also coupled to the TCA cycle rate in astrocytes. For that we investigated energy metabolism by means of magnetic resonance spectroscopy (MRS) in the primary visual cortex of tree shrews (Tupaia belangeri) under light isoflurane anesthesia at rest and during continuous visual stimulation. After identifying the activated cortical volume by blood oxygenation level-dependent functional magnetic resonance imaging, 1 H MRS was performed to measure stimulation-induced variations in metabolite concentrations. Relative to baseline, stimulation of cortical activity for 20 min caused a reduction of glucose concentration by -0.34 ± 0.09 µmol/g (p < 0.001), as well as a -9% ± 1% decrease of the ratio of phosphocreatine-to-creatine (p < 0.05). Then 13 C MRS during [1,6- 13 C]glucose infusion was employed to measure fluxes of energy metabolism. Stimulation of glutamatergic activity, as indicated by a 20% increase of V NT , resulted in increased TCA cycle rates in neurons by 12% ( VTCAn, p < 0.001) and in astrocytes by 24% ( VTCAg, p = 0.007). We further observed linear relationships between V NT and both VTCAn and VTCAg. Altogether, these results suggest that in the tree shrew primary visual cortex glutamatergic neurotransmission is linked to overall glucose oxidation and to mitochondrial metabolism in both neurons and astrocytes. © 2017 Wiley Periodicals, Inc.

Cannabidiolic acid prevents vomiting in Suncus murinus and nausea-induced behaviour in rats by enhancing 5-HT1A receptor activation

PubMed Central

Bolognini, D; Rock, EM; Cluny, NL; Cascio, MG; Limebeer, CL; Duncan, M; Stott, CG; Javid, FA; Parker, LA; Pertwee, RG

2013-01-01

Background and Purpose To evaluate the ability of cannabidiolic acid (CBDA) to reduce nausea and vomiting and enhance 5-HT1A receptor activation in animal models. Experimental Approach We investigated the effect of CBDA on (i) lithium chloride (LiCl)-induced conditioned gaping to a flavour (nausea-induced behaviour) or a context (model of anticipatory nausea) in rats; (ii) saccharin palatability in rats; (iii) motion-, LiCl- or cisplatin-induced vomiting in house musk shrews (Suncus murinus); and (iv) rat brainstem 5-HT1A receptor activation by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and mouse whole brain CB1 receptor activation by CP55940, using [35S]GTPγS-binding assays. Key Results In shrews, CBDA (0.1 and/or 0.5 mg·kg−1 i.p.) reduced toxin- and motion-induced vomiting, and increased the onset latency of the first motion-induced emetic episode. In rats, CBDA (0.01 and 0.1 mg·kg−1 i.p.) suppressed LiCl- and context-induced conditioned gaping, effects that were blocked by the 5-HT1A receptor antagonist, WAY100635 (0.1 mg·kg−1 i.p.), and, at 0.01 mg·kg−1 i.p., enhanced saccharin palatability. CBDA-induced suppression of LiCl-induced conditioned gaping was unaffected by the CB1 receptor antagonist, SR141716A (1 mg·kg−1 i.p.). In vitro, CBDA (0.1–100 nM) increased the Emax of 8-OH-DPAT. Conclusions and Implications Compared with cannabidiol, CBDA displays significantly greater potency at inhibiting vomiting in shrews and nausea in rats, and at enhancing 5-HT1A receptor activation, an action that accounts for its ability to attenuate conditioned gaping in rats. Consequently, CBDA shows promise as a treatment for nausea and vomiting, including anticipatory nausea for which no specific therapy is currently available. PMID:23121618

Heavy-metal concentrations in small mammals from a diffusely polluted floodplain: importance of species- and location-specific characteristics.

PubMed

Wijnhoven, S; Leuven, R S E W; van der Velde, G; Jungheim, G; Koelemij, E I; de Vries, F T; Eijsackers, H J P; Smits, A J M

2007-05-01

The soil of several floodplain areas along large European rivers shows increased levels of heavy metals as a relict from past sedimentation of contaminants. These levels may pose risks of accumulation in food webs and toxicologic effects on flora and fauna. However, for floodplains, data on heavy-metal concentrations in vertebrates are scarce. Moreover, these environments are characterised by periodical flooding cycles influencing ecologic processes and patterns. To investigate whether the suggested differences in accumulation risks for insectivores and carnivores, omnivores, and herbivores are reflected in the actual heavy-metal concentrations in the species, we measured the current levels of Zn, Cu, Pb, and Cd in 199 specimens of 7 small mammal species (voles, mice, and shrews) and in their habitats in a diffusely polluted floodplain. The highest metal concentrations were found in the insectivorous and carnivorous shrew, Sorex araneus. Significant differences between the other shrew species, Crocidura russula, and the vole and mouse species was only found for Cd. The Cu concentration in Clethrionomys glareolus, however, was significantly higher than in several other vole and mouse species. To explain the metal concentrations found in the specimens, we related them to environmental variables at the trapping locations and to certain characteristics of the mammals. Variables taken into account were soil total and CaCl(2)-extractable metal concentrations at the trapping locations; whether locations were flooded or nonflooded; the trapping season; and the life stage; sex; and fresh weight of the specimens. Correlations between body and soil concentrations and location or specimen characteristics were weak. Therefore; we assumed that exposure of small mammals to heavy-metal contamination in floodplains is significantly influenced by exposure time, which is age related, as well as by dispersal and changes in foraging and feeding patterns under influence of periodic flooding.

Effectiveness of Hyperopic Defocus, Minimal Defocus, or Myopic Defocus in Competition with a Myopiagenic Stimulus in Tree Shrew Eyes

PubMed Central

Norton, Thomas T.; Siegwart, John T.; Amedo, Angela O.

2007-01-01

Purpose To examine the ability of hyperopic defocus, minimal defocus, and myopic defocus to compete against a myopiagenic −5-D lens in juvenile tree shrew eyes. Methods Juvenile tree shrews (n ≥ 5 per group), on a 14-hour lights-on/10-hour lights-off schedule, wore a monocular −5-D lens (a myopiagenic stimulus) over the right eye in their home cages for more than 23 hours per day for 11 days. For 45 minutes each day, the animals were restrained so that all visual stimuli were >1 m away. While viewing distance was controlled, the −5-D lens was removed and another lens was substituted with one of the following spherical powers: −5 D, −3 D (hyperopic defocus); plano (minimal defocus); or +3, +4, +5, +6, or +10 D (myopic defocus). Daily noncycloplegic autorefractor measures were made on most animals. After 11 days of treatment, cycloplegic refractive state and axial component dimensions were measured. Results Eyes with the substituted −5- or −3-D-lens developed significant myopia (mean ± SEM, −4.7 ± 0.3 and −3.1 ± 0.1 D, respectively) and appropriate vitreous chamber elongation. All animals with the substituted plano lens (minimal defocus) during the 45-minute period showed no axial elongation or myopia (the plano lens competed effectively against the −5-D lens). Variable results were found among animals that wore a plus lens (myopic defocus). In 11 of 20 eyes, a +3-, +4-, or +5-D lens competed effectively against the −5-D lens (treated eye <1.5 D myopic relative to its fellow control eye). In the other eyes (9/20) myopic defocus was ineffective in blocking compensation; the treated eye became more than 2.5 D myopic relative to the control eye. The +6- and +10-D substituted lenses were ineffective in blocking compensation in all cases. Conclusions When viewing distance was limited to objects >1 m away, viewing through a plano lens for 45 minutes (minimal defocus) consistently prevented the development of axial elongation and myopia in response to a myopiagenic −5-D lens. Myopic defocus prevented compensation in some but not all animals. Thus, myopic defocus is encoded by at least some tree shrew retinas as being different from hyperopic defocus, and myopic defocus can sometimes counteract the myopiagenic effect of the −5-D lens (hyperopic defocus). However, it appears that minimal defocus is a more consistent, strong antidote to a myopiagenic stimulus in this mammal closely related to primates. PMID:17065475

Effective of diode laser on teeth enamel in the teeth whitening treatment

NASA Astrophysics Data System (ADS)

Klunboot, U.; Arayathanitkul, K.; Chitaree, R.; Emarat, N.

2011-12-01

This research purpose is to investigate the changing of teeth color and to study the surface of teeth after treatment by laser diode at different power densities for tooth whitening treatment. In the experiment, human-extracted teeth samples were divided into 7 groups of 6 teeth each. After that laser diode was irradiated to teeth, which were coated by 38% concentration of hydrogen peroxide, during for 20, 30 and 60 seconds at power densities of 10.9 and 52.1 W/cm2. The results of teeth color change were described by the CIEL*a*b* systems and the damage of teeth surface were investigated by scanning electron microscopy (SEM). The results showed that the power density of the laser diode could affect the whiteness of teeth. The high power density caused more luminous teeth than the low power density did, but on the other hand the high power density also caused damage to the teeth surface. Therefore, the laser diode at the low power densities has high efficiency for tooth whitening treatment and it has a potential for other clinical applications.

Investigation of trophic level and niche partitioning of 7 cetacean species by stable isotopes, and cadmium and arsenic tissue concentrations in the western Pacific Ocean.

PubMed

Liu, J-Y; Chou, L-S; Chen, M-H

2015-04-15

A total of 24 stranded or bycatch cetaceans, including Balaenoptera omurai, Lagenodelphis hosei, Kogia sima, Stenella attenuata, Grampus griseus, Neophocaena phocaenoides, and Sousa chinensis, were collected from 2001 to 2011 in Taiwan. Using the muscular δ(13)C and δ(15)N data, three ecological groups were identified as the oceanic baleen whale, the neritic, and the coastal toothed whale groups, coinciding with their taxonomy, feeding habits and geographical distribution. A horizontal inshore to offshore distribution was found for the sympatric neritic toothed dolphins, G. griseus, K. sima, S. attenuata, and L. hosei in the outermost offshore waters, accompanying their growth. For the first time we identify Taiwan's Chinese white dolphin, S. chinensis, as an exclusive fish eater. Cd and As bioaccumulated in the G. griseus, L. hosei and S. attenuata increase as they grow. Prey-derived As- and Cd-induced health threats were found in L. hosei, and G. griseus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Staged Hard and Soft Tissue Reconstruction Followed by Implant Supported Restoration in the Aesthetic Zone: A Case Report.

PubMed

Parthasarathy, Harinath; Ramachandran, Lakshmi; Tadepalli, Anupama; Ponnaiyan, Deepa

2017-04-01

Alveolar ridge deficiency is a common clinical consequence following tooth loss due to chronic periodontitis complicating ideal implant placement. Advanced hard and soft tissue augmentation procedures have been developed in the recent past with predictable clinical outcomes. A male patient presented with a Grade III mobile upper right central incisor associated with advanced bone loss and soft tissue deficit. Following extraction of tooth #11, socket augmentation was done using an autogenous cortico-cancellous block graft and subsequent soft tissue augmentation was done with palatal connective tissue graft. At the end of six months, a tapered self tapping implant fixture was placed with adequate primary stability and after eight weeks, second stage implant surgery was done with the Misch technique in order to recreate papillae and the implant was prosthetically restored. The alveolar ridge was adequately recontoured following the staged surgical protocol. The implant was well integrated at the end of 15 months. Execution of sequential surgical procedures in a highly deficient edentulous site made it possible to achieve of optimal pink and white aesthetics with stable implant supported fixed prosthesis.

The Impact of Fluoride on Ameloblasts and the Mechanisms of Enamel Fluorosis

PubMed Central

Bronckers, A.L.J.J.; Lyaruu, D.M.; DenBesten, P.K.

2009-01-01

Intake of excess amounts of fluoride during tooth development cause enamel fluorosis, a developmental disturbance that makes enamel more porous. In mild fluorosis, there are white opaque striations across the enamel surface, whereas in more severe cases, the porous regions increase in size, with enamel pitting, and secondary discoloration of the enamel surface. The effects of fluoride on enamel formation suggest that fluoride affects the enamel-forming cells, the ameloblasts. Studies investigating the effects of fluoride on ameloblasts and the mechanisms of fluorosis are based on in vitro cultures as well as animal models. The use of these model systems requires a biologically relevant fluoride dose, and must be carefully interpreted in relation to human tooth formation. Based on these studies, we propose that fluoride can directly affect the ameloblasts, particularly at high fluoride levels, while at lower fluoride levels, the ameloblasts may respond to local effects of fluoride on the mineralizing matrix. A new working model is presented, focused on the assumption that fluoride increases the rate of mineral formation, resulting in a greater release of protons into the forming enamel matrix. PMID:19783795

A novel autosomal-recessive mutation, whitish chalk-like teeth, resembling amelogenesis imperfecta, maps to rat chromosome 14 corresponding to human 4q21.

PubMed

Masuyama, Taku; Miyajima, Katsuhiro; Ohshima, Hayato; Osawa, Masaru; Yokoi, Norihide; Oikawa, Toshihiro; Taniguchi, Kazuyuki

2005-12-01

A rat mutant, whitish chalk-like teeth (wct), with white, chalk-like abnormal incisors, was discovered and morphologically and genetically characterized. The mutant rats showed tooth enamel defects that were similar to those of human amelogenesis imperfecta. The wct mutation was found to disturb the morphological transition of ameloblasts from secretory to maturation stages and to induce cyst formation. This mutation also disturbs the transfer of iron into the enamel, resulting in the whitish chalk-like incisors. A genetic linkage study indicated that the wct locus maps to a specific interval of rat chromosome 14 between D14Got13 and D14Wox2. Interestingly, the human chromosomal region orthologous to wct, a 5.5-Mb interval in human chromosome 4q21, is a critical region for the locus of human amelogenesis imperfecta AIH2. These results strongly suggest that this wct mutant is a useful model for the identification of genes responsible for amelogenesis imperfecta and molecular mechanisms of tooth development.

Effect of local administration of simvastatin on postorthodontic relapse in a rabbit model.

PubMed

AlSwafeeri, Hani; ElKenany, Walid; Mowafy, Mohamed; Karam, Sahar

2018-06-01

Posttreatment relapse is a major challenging clinical issue. The objective of this study was to evaluate the effect of local administration of simvastatin on posttreatment relapse. Orthodontic tooth movement was induced in 10 white New Zealand rabbits. After 21 days of active tooth movement, the orthodontic appliances were removed, and the experimental teeth were allowed to relapse for 21 days. During the relapse phase, 1 mandibular quadrant received local simvastatin administration, and the other received the control vehicle solution on a weekly basis. Three-dimensional models of the experimental teeth were created to allow the measurement of experimental tooth movement and posttreatment relapse. The animals were killed at the end of the relapse phase for histomorphometric analysis of alveolar bone remodeling. The mean relapse percentages were 75.83% in the quadrant receiving the control vehicle solution and 62.01% in the quadrant receiving simvastatin. Neither the relapse magnitude nor the relapse percentage showed a significant difference between the 2 quadrants. Histomorphometric analyses showed that local simvastatin administration yielded a significant reduction in the area of active bone-resorptive lacunae and a significant increase in newly formed bone area. Although local administration of simvastatin aids in bone remodeling associated with posttreatment relapse by reducing the area of active bone resorption and upregulating bone formation, it did not significantly minimize posttreatment relapse. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Detection of white spot lesions by segmenting laser speckle images using computer vision methods.

PubMed

Gavinho, Luciano G; Araujo, Sidnei A; Bussadori, Sandra K; Silva, João V P; Deana, Alessandro M

2018-05-05

This paper aims to develop a method for laser speckle image segmentation of tooth surfaces for diagnosis of early stages caries. The method, applied directly to a raw image obtained by digital photography, is based on the difference between the speckle pattern of a carious lesion tooth surface area and that of a sound area. Each image is divided into blocks which are identified in a working matrix by their χ 2 distance between block histograms of the analyzed image and the reference histograms previously obtained by K-means from healthy (h_Sound) and lesioned (h_Decay) areas, separately. If the χ 2 distance between a block histogram and h_Sound is greater than the distance to h_Decay, this block is marked as decayed. The experiments showed that the method can provide effective segmentation for initial lesions. We used 64 images to test the algorithm and we achieved 100% accuracy in segmentation. Differences between the speckle pattern of a sound tooth surface region and a carious region, even in the early stage, can be evidenced by the χ 2 distance between histograms. This method proves to be more effective for segmenting the laser speckle image, which enhances the contrast between sound and lesioned tissues. The results were obtained with low computational cost. The method has the potential for early diagnosis in a clinical environment, through the development of low-cost portable equipment.

Archaeological and Paleontological Investigation at Kalaeloa (Barber’s Point), Honouliuli, ’EWA, O’Ahu Island, Federal Study Areas 1a and 1b, and State of Hawaii Optional Area 1,

DTIC Science & Technology

1981-07-01

gravel, slightly sticky, slightly plastic, massive structure. Granule size limestone decreases with depth. Color whitens with depth influenced by neutral...fish. Vertebrae from shark or ray are present in 2787 and 2745 and fragments of large toothed jaws, tentatively identified as crevally (ulua) are present...a white enameled 5-gallon liquid dispenser sits on top a wooden crate. The barracks is wired for lighting with a drop-cord light over the desks

The use of albendazole for the treatment of trematodiasis in two tree shrews (Tupala glis)

USGS Publications Warehouse

Beehler, B.A.; Tuggle, B.N.

1983-01-01

Albendazole is a broad-spectrum anthelmintic of the benzimidazole group which has been tested in several rodents and domestic animals. Albendazole has been used effectively to treat trematodes in sheep, cattle, dogs, and cats. The use of this anthelmintic in exotic small mammals has not been reported to the authors' knowledge.

California Wild Summer 2003 - Rafflesia

Science.gov Websites

-tipped warts—the anthers—which exuded slimy pollen. In female flowers, which are much rarer, tiny the wound. Other scientists think that tree shrews or ground squirrels gnaw the columns of dead female female, seeds in the remnant of the central column are now available for dispersal. Although long

Non-surgical retreatment of a failed apicoectomy without retrofilling using white mineral trioxide aggregate as an apical barrier.

PubMed

Stefopoulos, Spyridon; Tzanetakis, Giorgos N; Kontakiotis, Evangelos G

2012-01-01

Root-end resected teeth with persistent apical periodontitis are usually retreated surgically or a combination of non-surgical and surgical retreatment is employed. However, patients are sometimes unwilling to be subjected to a second surgical procedure. The apical barrier technique that is used for apical closure of immature teeth with necrotic pulps may be an alternative to non-surgically retreat a failed apicoectomy. Mineral trioxide aggregate (MTA) has become the material of choice in such cases because of its excellent biocompatibility, sealing ability and osseoinductive properties. This case report describes the non-surgical retreatment of a failed apicoectomy with no attempt at retrofilling of a maxillary central incisor. White MTA was used to induce apical closure of the wide resected apical area. Four-year follow-up examination revealed an asymptomatic, fully functional tooth with a satisfactory healing of the apical lesion. White MTA apical barrier may constitute a reliable and efficient technique to non-surgically retreat teeth with failed root-end resection. The predictability of such a treatment is of great benefit for the patient who is unwilling to be submitted to a second surgical procedure.

Hyperglycemia and xerostomia are key determinants of tooth decay in type 1 diabetic mice.

PubMed

Yeh, Chih-Ko; Harris, Stephen E; Mohan, Sumathy; Horn, Diane; Fajardo, Roberto; Chun, Yong-Hee Patricia; Jorgensen, James; Macdougall, Mary; Abboud-Werner, Sherry

2012-06-01

Insulin-dependent type 1 diabetes mellitus (DM) and oral diseases are closely interrelated. Poor metabolic control in diabetics is associated with a high risk of gingivitis, periodontitis and tooth loss. Salivary flow declines in diabetics and patients suffer from xerostomia. Reduced saliva predisposes to enamel hypomineralization and caries formation; however, the mechanisms that initiate and lead to progression of tooth decay and periodontitis in type 1 DM have not been explored. To address this issue, we analyzed tooth morphology in Akita ⁻/⁻ mice that harbor a point mutation in the Ins2 insulin gene, which leads to progressive hyperglycemia. Mandibles from Akita ⁻/⁻ and wild-type littermates were analyzed by microCT, scanning EM and histology; teeth were examined for amelogenin (Amel) and ameloblastin (Ambn) expression. Mice were injected with pilocarpine to assess saliva production. As hyperglycemia may alter pulp repair, the effect of high glucose levels on the proliferation/differentiation of cultured MD10-F2 pulp cells was also analyzed. Results showed that Akita ⁻/⁻ mice at 6 weeks of age showed chalky white incisors that correlated with marked hyperglycemia and impaired saliva production. MicroCT of Akita ⁻/⁻ teeth revealed excessive enamel wearing and hypomineralization; immunostaining for Amel and Ambn was decreased. A striking feature was invasion of dentinal tubules with Streptococcus mitis and microabcesses that originated in the coronal pulp and progressed to pulp necrosis and periapical periodontitis. High levels of glucose also inhibited MD10-F2 cell proliferation and differentiation. Our findings provide the first evidence that hyperglycemia in combination with reduced saliva in a model of type1 DM leads to decreased enamel mineralization/matrix proteins and predisposes to excessive wearing and decay. Importantly, hyperglycemia adversely affects enamel matrix proteins and pulp repair. Early detection and treatment of hyperglycemia and hyposalivation may provide a useful strategy for preventing the dental complications of diabetes and promoting oral health in this population.

Esthetic evaluation of maxillary single-tooth implants in the esthetic zone

PubMed Central

Cho, Hae-Lyung; Lee, Jae-Kwan; Um, Heung-Sik

2010-01-01

Purpose The aim of this study is to assess the influence exerted by the observer's dental specialization and compare patients' opinion with observers' opinion of the esthetics of maxillary single-tooth implants in the esthetic zone. Methods Forty-one adult patients, who were treated with a single implant in the esthetic zone, were enrolled in this study. Eight observers (2 periodontists, 2 prosthodontists, 2 orthodontists and 2 senior dental students) applied the pink esthetic score (PES)/white esthetic score (WES) to 41 implant-supported single restorations twice with an interval of 4 weeks. We used a visual analog scale (VAS) to assess the patient's satisfaction with the treatment outcome from an esthetic point of view. Results In the PES/WES, very good and moderate intraobserver agreements were noted between the first and second rating. The mean total PES/WES was 11.19 ± 3.59. The mean PES was 5.17 ± 2.29 and mean WES was 6.02 ± 1.96. In the total PES/WES, the difference between the groups was not significant. However, in the WES, the difference between the groups was significant and prosthodontists were found to have assigned poorer ratings than the other groups. Periodontists gave higher ratings than prosthodontists and senior dental students. Orthodontists were clearly more critical than the other observers. The statistical analysis revealed statistically significant correlation between patients' esthetic perception and dentists' perception of the anterior tooth. However, the correlation between the total PES/WES and the VAS score for the first premolar was not statistically significant. Conclusions The PES/WES is an objective tool in rating the esthetics of implant supported single crowns and adjacent soft tissues. Orthodontists were the most critical observers, while periodontists were more generous than other observers. The statistical analysis revealed a statistically significant correlation between patients' esthetic perception and dentists' perception of the anterior tooth. PMID:20827328

Anterior dental microwear textures show habitat-driven variability in Neandertal behavior.

PubMed

Krueger, Kristin L; Ungar, Peter S; Guatelli-Steinberg, Debbie; Hublin, Jean-Jacques; Pérez-Pérez, Alejandro; Trinkaus, Erik; Willman, John C

2017-04-01

The causes of Neandertal anterior tooth wear patterns, including labial rounding, labial scratches, and differential anterior-posterior wear, have been debated for decades. The most common explanation is the "stuff-and-cut" hypothesis, which describes Neandertals clamping down on a piece of meat and slicing a portion close to their lips. "Stuff-and-cut" has been accepted as a general aspect of Neandertal behavior without fully assessing its variability. This study analyzes anterior dental microwear textures across habitats, locations, and time intervals to discern possible variation in Neandertal anterior tooth-use behavior. Forty-five Neandertals from 24 sites were analyzed, represented by high-resolution replicas of permanent anterior teeth. The labial surface was scanned for antemortem microwear using a white-light confocal profiler. The resultant 3D-point clouds, representing 204 × 276 μm for each specimen, were uploaded into SSFA software packages for texture characterization. Statistical analyses, including MANOVAs, ANOVAs, and pairwise comparisons, were completed on ranked microwear data. Neandertal descriptive statistics were also compared to 10 bioarchaeological samples of known or inferred dietary and behavioral regimes. The Neandertal sample varied significantly by habitat, suggesting this factor was a principal driving force for differences in Neandertal anterior tooth-use behaviors. The Neandertals from open habitats showed significantly lower anisotropy and higher textural fill volume than those inhabiting more closed, forested environments. The texture signature from the open-habitat Neandertals was most similar to that of the Ipiutak and Nunavut, who used their anterior teeth for intense clamping and grasping behaviors related to hide preparation. Those in more closed habitats were most similar to the Arikara, who did not participate in non-dietary behaviors. These Neandertal individuals had a broad range of texture values consistent with non-dietary and dietary behaviors, suggesting they varied more in anterior tooth-use behaviors and exploited a wider variety of plant and animal resources than did those from open habitats. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hyperglycemia and xerostomia are key determinants of tooth decay in type 1 diabetic mice

PubMed Central

Yeh, Chih-Ko; Harris, Stephen E; Mohan, Sumathy; Horn, Diane; Fajardo, Roberto; Chun, Yong-Hee Patricia; Jorgensen, James; MacDougall, Mary; Abboud-Werner, Sherry

2012-01-01

Insulin-dependent type 1 diabetes mellitus (DM) and oral diseases are closely interrelated. Poor metabolic control in diabetics is associated with a high risk of gingivitis, periodontitis and tooth loss. Salivary flow declines in diabetics and patients suffer from xerostomia. Reduced saliva predisposes to enamel hypomineralization and caries formation; however, the mechanisms that initiate and lead to progression of tooth decay and periodontitis in type 1 DM have not been explored. To address this issue, we analyzed tooth morphology in Akita −/− mice that harbor a point mutation in the Ins2 insulin gene, which leads to progressive hyperglycemia. Mandibles from Akita −/− and wild-type littermates were analyzed by microCT, scanning EM and histology; teeth were examined for amelogenin (Amel) and ameloblastin (Ambn) expression. Mice were injected with pilocarpine to assess saliva production. As hyperglycemia may alter pulp repair, the effect of high glucose levels on the proliferation/differentiation of cultured MD10-F2 pulp cells was also analyzed. Results showed that Akita −/− mice at 6 weeks of age showed chalky white incisors that correlated with marked hyperglycemia and impaired saliva production. MicroCT of Akita −/− teeth revealed excessive enamel wearing and hypomineralization; immunostaining for Amel and Ambn was decreased. A striking feature was invasion of dentinal tubules with Streptococcus mitis and microabcesses that originated in the coronal pulp and progressed to pulp necrosis and periapical periodontitis. High levels of glucose also inhibited MD10-F2 cell proliferation and differentiation. Our findings provide the first evidence that hyperglycemia in combination with reduced saliva in a model of type1 DM leads to decreased enamel mineralization/matrix proteins and predisposes to excessive wearing and decay. Importantly, hyperglycemia adversely affects enamel matrix proteins and pulp repair. Early detection and treatment of hyperglycemia and hyposalivation may provide a useful strategy for preventing the dental complications of diabetes and promoting oral health in this population. PMID:22449801

Evolution of alanine:glyoxylate aminotransferase 1 peroxisomal and mitochondrial targeting. A survey of its subcellular distribution in the livers of various representatives of the classes Mammalia, Aves and Amphibia.

PubMed

Danpure, C J; Fryer, P; Jennings, P R; Allsop, J; Griffiths, S; Cunningham, A

1994-08-01

As part of a wider study on the molecular evolution of alanine:glyoxylate aminotransferase 1 (AGT1) intracellular compartmentalization, we have determined the subcellular distribution of immunoreactive AGT1, using postembedding protein A-gold immunoelectron microscopy, in the livers of various members of the classes Mammalia, Aves, and Amphibia. As far as organellar distribution is concerned, three categories could be distinguished. In members of the first category (type I), all, or nearly all, of the immunoreactive AGT1 was concentrated within the peroxisomes. In the second category (type II), AGT1 was found more evenly distributed in both peroxisomes and mitochondria. In the third category (type III), AGT1 was localized mainly within the mitochondria with much lower, but widely variable, amounts in the peroxisomes. Type I animals include the human, two great apes (gorilla, orangutan), two Old World monkeys (anubis baboon, Japanese macaque), a New World monkey (white-faced Saki monkey), a lago, morph (European rabbit), a bat (Seba's short-tailed fruit bat), two caviomorph rodents (guinea pig, orange-rumped agouti), and two Australian marsupials (koala, Bennett's wallaby). Type II animals include two New World monkeys (common marmoset, cotton-top tamarin), three prosimians (brown lemur, fat-tailed dwarf lemur, pygmy slow loris), five rodents (a hybrid crested porcupine, Colombian ground squirrel, laboratory rat, laboratory mouse, golden hamster), an American marsupial (grey short-tailed opossum), and a bird (raven). Type III animals include the large tree shrew, three insectivores (common Eurasian mole, European hedgehog, house shrew), four carnivores (domestic cat, ocelot, domestic dog, polecat ferret), and an amphibian (common frog). In addition to these categories, some animals (e.g. guinea pig, common frog) possessed significant amounts of cytosolic AGT1. Whereas the subcellular distribution of AGT1 in some orders (e.g. Insectivora and Carnivora) did not appear to vary markedly between the different members, in other orders (e.g. Primates, Rodentia and Marsupialia) it fluctuated widely between the different species. Phylogenetic analysis indicates that the subcellular distribution of AGT1 has changed radically on numerous occasions during the evolution of mammals. The new observations presented in this paper are compatible with our previous demonstration of a relationship between AGT1 subcellular distribution and either present or putative ancestral dietary habit, and our previous suggestion that the molecular evolution of the AGT gene has been markedly influenced by dietary selection pressure.

In vitro effect of fluoride oral hygiene tablets on artificial caries lesion formation and remineralization in human enamel

PubMed Central

Gängler, Peter; Kremniczky, Thomas; Arnold, Wolfgang H

2009-01-01

Background Aim of this in-vitro-study was to assess the remineralization potential of a tooth cleaning tablet with different fluoride content. Methods Twenty three caries free impacted third molars were examined, enamel surfaces were wax coated leaving two 3 × 4 mm windows for exposure to demineralization/remineralization cycles. The teeth were randomly assigned to 4 groups of 5 control and 6 experimental teeth. Demineralization by standardised HEC-gel, pH 4.7 at 37°C for 72 h, was alternated by rinsing in remineralization solution, pH 7.0 at 37°C for 72 h, total challenge time 432 h. The negative control group N was treated during remineralization cycles with saline; positive control group P was treated with remineralization solution; experimental group D1 was exposed to remineralization solution containing Denttabs®-tablets with 1450 ppm F; experimental group D2 was exposed to remineralization solution and Denttabs®-tablets with 4350 ppm F. Each tooth was cut into serial sections and analyzed by polarized light microscopy for assessment of the different zones of white-spot lesions in 3 representative sections. Statistical analysis was based on the Mann-Whitney-Test. Results Both control groups N(-) and P(+) exhibited characteristic white-spot lesions. The remineralization and the demineralization inhibition of the lesions increased considerably from N

Shrew species richness and abundance in relation to vernal pond habitat in southern New England

Treesearch

Robert T. Brooks; Katherine L. Doyle

2001-01-01

Vernal ponds are important aquatic habitat for many species of amphibians and invertebrates. While many aspects of such ponds have been investigated, small mammal populations in the adjacent upland [catchment] habitat are largely unstudied. We selected three ponds in central Massachusetts to determine whether the presence of vernal ponds in forested habitat influences...

Genomic Imprinting of the M6P/IGF2 Receptor: A Novel Breast Cancer Susceptibility Mechanism

DTIC Science & Technology

2000-07-01

i.e. echidna and platypus ), marsupials (i.e. opossum) and eutherian mammals (i.e. mouse, rat, pig, cow, bat, flying lemur, tree shrew, ringtail lemur...and humans). Our findings demonstrate that M6P/IGF2R is not imprinted in the egg-laying platypus and echidna, whereas it is imprinted in the opossum

Thinning effects on spotted owl prey and other forest-dwelling small mammals

Treesearch

Todd M. Willson; Eric D. Forsman

2013-01-01

Th inning has been promoted as a method for accelerating the development of late-seral habitat and improving the overall health and function of young forests in the Pacifi c Northwest. Population studies have shown early and positive responses to thinning by some small forest-floor mammals (primarily mice, terrestrial voles, and shrews). However, thinning reduces the...

In vitro colorimetric evaluation of the efficacy of home bleaching and over-the-counter bleaching products.

PubMed

Dietschi, Didier; Benbachir, Nacer; Krejci, Ivo

2010-06-01

Various bleaching modalities are now offered to patients, either monitored by the dental office or self-directed, for which relative efficiency is unknown. The aim of this in vitro study was to evaluate the ability of bleaching products and protocols to lighten enamel and dentin. Bovine tooth specimens of standardized thickness (2.5 +/- 0.025 mm with similar dentin and enamel thickness) were prepared and stained with whole blood and hemolysate before being submitted to seven supervised or self-directed bleaching regimens: tray-based bleaching using 10% (Opalescence, Ultradent; Nite White, Discus Dental) or light-activated 30% (Metatray, Metatray) carbamide peroxide (CP); 6% (Zoom, Discus Dental) or 9% (TresWhite, Ultradent) hydrogen peroxide (HP); strips (Whitening Strips, Oral B-Rembrandt); and paint-on gel (Paint on Plus, Ivoclar Vivadent) containing 8.1% and 6% HP, respectively. Colorimetric measurements were performed on each specimen side, according to the CIE L*a*b* system, before and after staining, as well as after 5, 10, and the recommended number of bleaching applications. Color change after recommended number of applications (DEr) varied from 15.72 (Metatray) to 29.67 (Nite White) at enamel and 14.91 (Paint on Plus) to 41.43 (Nite White) at dentin side; Nite White (10% CP) and TresWhite (9% HP) were more effective than Metatray (30% CP) and Paint on Plus (6% HP) after 5 or the recommended number of applications. In this in vitro study based on bovine teeth, tray-based systems produced the faster and better bleaching effect, regardless of the product and concentration used, at both enamel and dentin sides.

Short interspersed elements (SINEs) from insectivores. Two classes of mammalian SINEs distinguished by A-rich tail structure.

PubMed

Borodulina, O R; Kramerov, D A

2001-10-01

Four tRNA-related SINE families were isolated from the genome of the shrew Sorex araneus (SOR element), mole Mogera robusta (TAL element), and hedgehog Mesechinus dauuricus (ERI-1 and ERI-2 elements). Each of these SINEs families is specific for a single Insectivora family: SOR, for Soricidae (shrews); TAL, for Talpidae (moles and desmans); ERI-1 and ERI-2, for Erinaceidae (hedgehogs). There is a long polypyrimidine region (TC-motif) in TAL, ERI-1, and ERI-2 elements located immediately upstream of an A-rich tail with polyadenylation signals (AATAAA) and an RNA polymerase III terminator (T(4-6)) or TCT(3-4)). Ten out of 14 analyzed mammalian tRNA-related SINE families have an A-rich tail similar to that of TAL, ERI-1, and ERI-2 elements. These elements were assigned to class T+. The other four SINEs including SOR element have no polyadenylation signal and transcription terminator in their A-rich tail and were assigned to class T-. Class T+ SINEs occur only in mammals, and most of them have a long polypyrimidine region. Possible models of retroposition of class T+ and T- SINEs are discussed.

The Celtic fringe of Britain: insights from small mammal phylogeography

PubMed Central

Searle, Jeremy B.; Kotlík, Petr; Rambau, Ramugondo V.; Marková, Silvia; Herman, Jeremy S.; McDevitt, Allan D.

2009-01-01

Recent genetic studies have challenged the traditional view that the ancestors of British Celtic people spread from central Europe during the Iron Age and have suggested a much earlier origin for them as part of the human recolonization of Britain at the end of the last glaciation. Here we propose that small mammals provide an analogue to help resolve this controversy. Previous studies have shown that common shrews (Sorex araneus) with particular chromosomal characteristics and water voles (Arvicola terrestris) of a specific mitochondrial (mt) DNA lineage have peripheral western/northern distributions with striking similarities to that of Celtic people. We show that mtDNA lineages of three other small mammal species (bank vole Myodes glareolus, field vole Microtus agrestis and pygmy shrew Sorex minutus) also form a ‘Celtic fringe’. We argue that these small mammals most reasonably colonized Britain in a two-phase process following the last glacial maximum (LGM), with climatically driven partial replacement of the first colonists by the second colonists, leaving a peripheral geographical distribution for the first colonists. We suggest that these natural Celtic fringes provide insight into the same phenomenon in humans and support its origin in processes following the end of the LGM. PMID:19793757

Radiation ecology issues associated with murine rodents and shrews in the Chernobyl exclusion zone.

PubMed

Gaschak, Sergey P; Maklyuk, Yulia A; Maksimenko, Andrey M; Bondarkov, Mikhail D; Jannik, G Timothy; Farfán, Eduardo B

2011-10-01

This article describes major studies performed by the Chernobyl Center's International Radioecology Laboratory (Slavutich, Ukraine) on radioecology of murine rodents and shrews inhabiting the Chernobyl Exclusion Zone. The article addresses the long-term (1986-2005) and seasonal dynamics of radioactive contamination of animals and reviews interspecies differences in radionuclide accumulations and factors affecting the radionuclide accumulations. It is shown that bioavailability of radionuclides in the "soil-to-plant" chain and a trophic specialization of animals play key roles in determining their actual contamination levels. The total absorbed dose rates in small mammals significantly reduced during the years following the Chernobyl Nuclear Power Plant accident. In 1986, the absorbed dose rate reached 1.3-6.0 Gy h(-1) in the central areas of the Chernobyl Exclusion Zone (the "Red Forest"). In 1988 and 1990, the total absorbed dose rates were 1.3 and 0.42 Gy h(-1), respectively. In 1995, 2000, and 2005, according to the present study, the total absorbed dose rates rarely exceeded 0.00023, 0.00018, and 0.00015 Gy h(-1), respectively. Contributions of individual radiation sources into the total absorbed dose are described.

A new species of Cryptotis (Mammalia, Eulipotyphla, Soricidae) from the Sierra de Perijá, Venezuelan-Colombian Andes

USGS Publications Warehouse

Quiroga-Carmona, Marcial; Woodman, Neal

2015-01-01

The Sierra de Perijá is the northern extension of the Cordillera Oriental of the Andes and includes part of the border between Colombia and Venezuela. The population of small-eared shrews (Mammalia, Eulipotyphla, Soricidae, Cryptotis) inhabiting the Sierra de Perijá previously was known from only a single skull from an individual collected in Colombia in 1989. This specimen had been referred to alternatively as C. thomasi and C. meridensis, but more precise definition of the known Colombian and Venezuelan species of Cryptotis has since excluded the Sierra de Perijá population from any named species. The recent collection of a specimen from the Venezuelan slope of Sierra de Perijá, prompted us to re-evaluate the taxonomic status of this population and determine its relationship with other Andean shrews. Our examination of the available specimens revealed that they possess a unique suite of morphological and morphometrical characters, and we describe the Sierra de Perijá population as a new species in the South American C. thomasi species group. Recognition of this new species adds to our knowledge of this genus in South America and to the biodiversity of the Sierra de Perijá.

Assessment of White Spot Lesions and In-Vivo Evaluation of the Effect of CPP-ACP on White Spot Lesions in Permanent Molars of Children.

PubMed

Munjal, Deepti; Garg, Shalini; Dhindsa, Abhishek; Sidhu, Gagandeep Kaur; Sethi, Harsimran Singh

2016-05-01

As hindrance of remineralisation process occurs during orthodontic therapy resulting in decalcification of enamel because number of plaque retention sites increases due to banding and bonding of appliances to teeth. The present analytic study was undertaken to assess the occurrence of white spot lesions in permanent molars of children with and without orthodontic therapy and to evaluate the effect of Casein PhosphoPeptide-Amorphous Calcium Phosphate (CPP-ACP) on white spot lesions in post-orthodontic patients in a given period of time. The study comprised of examination of 679 first permanent molars which were examined to assess the occurrence of smooth surface white spot lesions in children of 8 to 16 years age group. Group I comprised subjects without any orthodontic treatment and Group II comprised of subjects who had undergone orthodontic therapy. The sample size was calculated using the epi-info6 computer package. Treatment group included 20 post-orthodontic patients examined with at least one white spot lesion within the enamel who received remineralizing cream (GC Tooth Mousse, Recaldent, GC Corporation.) i.e., CPP-ACP cream two times a day for 12 consecutive weeks. Computerized image analysis method was taken to evaluate white spot lesions. These frequency and percentages were compared with chi-square test. For comparison of numeric data, paired t-test was used. Of the total 278 (49.6%) first permanent molars showed occurrence of smooth surface white spot lesions out of 560 in Group I and 107 (89.9%) first permanent molars showed presence of white spot lesions out of 119 debanded first permanent molars of children examined in Group II. CPP-ACP therapy group showed reduction in severity of codes which was found to be highly significant after 12 weeks and eight weeks on gingival-third, p-value (<0.001) and significant after eight weeks and four weeks on middle-third according to ICDAS II criteria and computerized image analysis. CPP-ACP therapy minimum for 12 weeks is highly recommended as post-orthodontic treatment need in management of smooth surface white spot lesions on teeth undergoing fixed orthodontic therapy according to the present study.

Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography.

PubMed

Maia, Ana Marly Araújo; de Freitas, Anderson Zanardi; de L Campello, Sergio; Gomes, Anderson Stevens Leônidas; Karlsson, Lena

2016-06-01

An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light-Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System. QLF versus OCT imaging of enamel caries: a photonics assessment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prevention and Treatment of White Spot Lesions in Orthodontic Patients.

PubMed

Khoroushi, Maryam; Kachuie, Marzie

2017-01-01

Decalcification of enamel, appearing as white spot lesions (WSLs), around fixed orthodontic appliances is a major challenge during and after fixed orthodontic treatment by considering the fact that the goal of orthodontic treatment is to enhance facial and dental esthetic appearance. Banded or bonded teeth exhibit a significantly higher rate of WSLs compared to the controls with no braces as fixed appliances and the bonding materials promote retention of biofilms. These lesions are managed in the first step by establishing good oral hygiene habits and prophylaxis with topical fluorides, including high-fluoride toothpastes, fluoride mouthwashes, gels, varnishes, fluoride-containing bonding materials, and elastic ligatures. Recently, other materials and methods have been recommended, including the application of casein phosphopeptides-amorphous calcium phosphate, antiseptics, probiotics, polyols, sealants, laser, tooth bleaching agents, resin infiltration, and microabrasion. This article reviews the currently used methods to manage enamel demineralization during and after orthodontic treatment and the risk factors and preventive measures based on the latest evidence.

Prevention and Treatment of White Spot Lesions in Orthodontic Patients

PubMed Central

Khoroushi, Maryam; Kachuie, Marzie

2017-01-01

Decalcification of enamel, appearing as white spot lesions (WSLs), around fixed orthodontic appliances is a major challenge during and after fixed orthodontic treatment by considering the fact that the goal of orthodontic treatment is to enhance facial and dental esthetic appearance. Banded or bonded teeth exhibit a significantly higher rate of WSLs compared to the controls with no braces as fixed appliances and the bonding materials promote retention of biofilms. These lesions are managed in the first step by establishing good oral hygiene habits and prophylaxis with topical fluorides, including high-fluoride toothpastes, fluoride mouthwashes, gels, varnishes, fluoride-containing bonding materials, and elastic ligatures. Recently, other materials and methods have been recommended, including the application of casein phosphopeptides-amorphous calcium phosphate, antiseptics, probiotics, polyols, sealants, laser, tooth bleaching agents, resin infiltration, and microabrasion. This article reviews the currently used methods to manage enamel demineralization during and after orthodontic treatment and the risk factors and preventive measures based on the latest evidence. PMID:28566845

Effect of 3 cements on white spot lesion formation after full-coverage rapid maxillary expander: A comparative in-vivo study.

PubMed

Yagci, Ahmet; Korkmaz, Yasemin Nur; Yagci, Filiz; Atilla, Aykan Onur; Buyuk, Suleyman Kutalmiş

2016-12-01

The aim of this study was to assess the effects of 3 luting agents (glass ionomer cement, compomer, and polycarboxylate cement) on white spot lesion formation in patients with full-coverage bonded acrylic splint expanders. White spot lesion formation was assessed with quantitative light-induced fluorescence. Full-coverage rapid maxillary expanders were cemented with glass ionomer cement, compomer, and polycarboxylate cement in groups 1, 2, and 3, respectively. A control group comprised patients who never had orthodontic treatment. Quantitative light-induced fluorescence images taken before and after rapid maxillary expansion treatment were analyzed for these parameters: the percentages of fluorescence loss with respect to the fluorescence of sound tooth tissue (ΔF) and maximum loss of fluorescence intensity in the whole lesion; lesion area with ΔF equal to less than a -5% threshold; and the percentage of fluorescence loss with respect to the fluorescence of sound tissue times the area that indicated lesion volume. All 3 groups showed statistically significantly greater demineralization than the control group. The 3 experimental groups differed from each other in half of the parameters calculated. Teeth in the polycarboxylate group developed the most white spot lesions. With the highest rate of white spot lesion formation, polycarboxylate cements should not be used for full-coverage bonded acrylic splint expanders. Compomers may be preferred over glass ionomer cements, based on the findings of this study. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

A longitudinal study of occlusal caries in Newark New Jersey school children: relationship between initial dental finding and the development of new lesions

PubMed Central

Markowitz, Kenneth; Fairlie, Karen; Ferrandiz, Javier; Nasri-Heir, Cibele

2012-01-01

Objective Dental caries is a significant public health problem especially amongst children from low-income backgrounds. This longitudinal study examined the development of new occlusal caries in 227 Newark, NJ children ages 10–18. The role of previous caries experience and the presence of occlusal white and dark lesions in predicting the development of new lesions were examined. Design At each visit, the patient’s teeth were given a visual-tactile examination and the subject’s decayed; missing and filled (DMFS) score was determined. Next, molars lacking probeable caries or restorations were examined using transillumination for occlusal white and dark spots. This examination was repeated periodically. A Cox proportional hazard was used to analyze data concerning the development of new occusal caries in molars. Results The longitudinal data indicates that patients who were caries free at visit-1 developed significantly fewer occlusal caries during the longitudinal study. The hazard ratio for subjects who had first-visit caries was 2.27 compared to caries free subjects. Intact molars with occlusal white or dark lesions had caries hazard ratios of 0.78 and 1.49 respectively, compared to molars lacking initial color changes. Conclusion Having a prior caries history places the subject at increased risk of developing future caries. Teeth with dark lesions but not white lesions are at significantly increased risk for developing decay. White lesions may represent remineralizing or slowly progressing lesions. The results of this study can help identify patients and tooth surfaces at risk for future occlusal decay. PMID:22841633

Test Area B-70 Final Range Environmental Assessment, Revision 1

DTIC Science & Technology

2009-06-01

the Sandhills and Open Grassland ecological associations on the Eglin Range, where it excavates a tunnel -like burrow for shelter from climatic extremes...Sciurus niger Gallberry Ilex glabra Least Shrew Cryptotis parva Gopher Apple Licania michauxii Cottontail Rabbit Sylvilagus floridanus Sand Blackberry ...within the Sandhills and Open Grassland ecological associations on Eglin, where it excavates a tunnel - like burrow for shelter from climatic extremes and

Response of soricid populations to repeated fire and fuel reduction treatments in the southern Appalachain Mountains

Treesearch

Charlotte E Matthews; Christopher E Moorman; Cathryn H Greenberg

2009-01-01

Fuel hazards have increased in forests across the United States because offire exclusion during the 20th century. Treatments used to reduce fuel buildup Illay affect wildlife. such as shrews. living 011 the forest floor. especially when treatments are applied repeatedly. From mid-May to mid-August 2006 and 2007.  we used drift fences...

Toward assessing the effects of bank stabilization activities on wildlife communities of the upper Yellowstone River, U.S.A

USGS Publications Warehouse

Skagen, Susan K.; Muths, Erin; Adams, Rod D.

2001-01-01

Four amphibian species, three reptile species, and one mammal species are highly vulnerable to bank stabilization activities. Tiger salamanders, boreal toads, western chorus frogs, spotted frogs, rubber boas, racers, western garter snakes, and water shrews are expected to respond primarily to alterations in stream and bank morphology and the loss of still water for amphibian breeding.

Intravitreally-administered dopamine D2-like (and D4), but not D1-like, receptor agonists reduce form-deprivation myopia in tree shrews.

PubMed

Ward, Alexander H; Siegwart, John T; Frost, Michael R; Norton, Thomas T

2017-01-01

We examined the effect of intravitreal injections of D1-like and D2-like dopamine receptor agonists and antagonists and D4 receptor drugs on form-deprivation myopia (FDM) in tree shrews, mammals closely related to primates. In eleven groups (n = 7 per group), we measured the amount of FDM produced by monocular form deprivation (FD) over an 11-day treatment period. The untreated fellow eye served as a control. Animals also received daily 5 µL intravitreal injections in the FD eye. The reference group received 0.85% NaCl vehicle. Four groups received a higher, or lower, dose of a D1-like receptor agonist (SKF38393) or antagonist (SCH23390). Four groups received a higher, or lower, dose of a D2-like receptor agonist (quinpirole) or antagonist (spiperone). Two groups received the D4 receptor agonist (PD168077) or antagonist (PD168568). Refractions were measured daily; axial component dimensions were measured on day 1 (before treatment) and day 12. We found that in groups receiving the D1-like receptor agonist or antagonist, the development of FDM and altered ocular component dimensions did not differ from the NaCl group. Groups receiving the D2-like receptor agonist or antagonist at the higher dose developed significantly less FDM and had shorter vitreous chambers than the NaCl group. The D4 receptor agonist, but not the antagonist, was nearly as effective as the D2-like agonist in reducing FDM. Thus, using intravitreally-administered agents, we did not find evidence supporting a role for the D1-like receptor pathway in reducing FDM in tree shrews. The reduction of FDM by the dopamine D2-like agonist supported a role for the D2-like receptor pathway in the control of FDM. The reduction of FDM by the D4 receptor agonist, but not the D4 antagonist, suggests an important role for activation of the dopamine D4 receptor in the control of axial elongation and refractive development.

Intravitreally-administered dopamine D2-like (and D4), but not D1-like, receptor agonists reduce form-deprivation myopia in tree shrews

PubMed Central

Ward, Alexander H.; Siegwart, John T.; Frost, Michael R.; Norton, Thomas T.

2017-01-01

We examined the effect of intravitreal injections of D1-like and D2-like dopamine receptor agonists and antagonists and D4 receptor drugs on form-deprivation myopia (FDM) in tree shrews, mammals closely related to primates. In eleven groups (n = 7 per group), we measured the amount of FDM produced by monocular form deprivation (FD) over an 11-day treatment period. The untreated fellow eye served as a control. Animals also received daily 5 μL intravitreal injections in the FD eye. The reference group received 0.85% NaCl vehicle. Four groups received a higher, or lower, dose of a D1-like receptor agonist (SKF38393) or antagonist (SCH23390). Four groups received a higher, or lower, dose of a D2-like receptor agonist (quinpirole) or antagonist (spiperone). Two groups received the D4 receptor agonist (PD168077) or antagonist (PD168568). Refractions were measured daily; axial component dimensions were measured on day 1 (before treatment) and day 12. We found that in groups receiving the D1-like receptor agonist or antagonist, the development of FDM and altered ocular component dimensions did not differ from the NaCl group. Groups receiving the D2-like receptor agonist or antagonist at the higher dose developed significantly less FDM and had shorter vitreous chambers than the NaCl group. The D4 receptor agonist, but not the antagonist, was nearly as effective as the D2-like agonist in reducing FDM. Thus, using intravitreally-administered agents, we did not find evidence supporting a role for the D1-like receptor pathway in reducing FDM in tree shrews. The reduction of FDM by the dopamine D2-like agonist supported a role for the D2-like receptor pathway in the control of FDM. The reduction of FDM by the D4 receptor agonist, but not the D4 antagonist, suggests an important role for activation of the dopamine D4 receptor in the control of axial elongation and refractive development. PMID:28304244

Inhibition of monoacylglycerol lipase attenuates vomiting in Suncus murinus and 2-arachidonoyl glycerol attenuates nausea in rats.

PubMed

Sticht, Martin A; Long, Jonathan Z; Rock, Erin M; Limebeer, Cheryl L; Mechoulam, Raphael; Cravatt, Benjamin F; Parker, Linda A

2012-04-01

To evaluate the role of 2-arachidonoyl glycerol (2AG) in the regulation of nausea and vomiting using animal models of vomiting and of nausea-like behaviour (conditioned gaping). Vomiting was assessed in shrews (Suncus murinus), pretreated with JZL184, a selective monoacylglycerol lipase (MAGL) inhibitor which elevates endogenous 2AG levels, 1 h before administering the emetogenic compound, LiCl. Regulation of nausea-like behaviour in rats by exogenous 2AG or its metabolite arachidonic acid (AA) was assessed, using the conditioned gaping model. The role of cannabinoid CB(1) receptors, CB(2) receptors and cyclooxygenase (COX) inhibition in suppression of vomiting or nausea-like behaviour was assessed. JZL184 dose-dependently suppressed vomiting in shrews, an effect prevented by pretreatment with the CB(1) receptor inverse agonist/antagonist, AM251. In shrew brain tissue, JZL184 inhibited MAGL activity in vivo. In rats, 2AG suppressed LiCl-induced conditioned gaping but this effect was not prevented by AM251 or the CB(2) receptor antagonist, AM630. Instead, the COX inhibitor, indomethacin, prevented suppression of conditioned gaping by 2AG or AA. However, when rats were pretreated with a high dose of JZL184 (40 mg·kg(-1) ), suppression of gaping by 2AG was partially reversed by AM251. Suppression of conditioned gaping was not due to interference with learning because the same dose of 2AG did not modify the strength of conditioned freezing to a shock-paired tone. Our results suggest that manipulations that elevate 2AG may have anti-emetic or anti-nausea potential. This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Predominant Leptospiral Serogroups Circulating among Humans, Livestock and Wildlife in Katavi-Rukwa Ecosystem, Tanzania

PubMed Central

Assenga, Justine A.; Matemba, Lucas E.; Muller, Shabani K.; Mhamphi, Ginethon G.; Kazwala, Rudovick R.

2015-01-01

Background Leptospirosis is a worldwide zoonotic disease and a serious, under-reported public health problem, particularly in rural areas of Tanzania. In the Katavi-Rukwa ecosystem, humans, livestock and wildlife live in close proximity, which exposes them to the risk of a number of zoonotic infectious diseases, including leptospirosis. Methodology/Principal Findings A cross-sectional epidemiological study was carried out in the Katavi region, South-west Tanzania, to determine the seroprevalence of Leptospira spp in humans, domestic ruminants and wildlife. Blood samples were collected from humans (n = 267), cattle (n = 1,103), goats (n = 248), buffaloes (n = 38), zebra (n = 2), lions (n = 2), rodents (n = 207) and shrews (n = 11). Decanted sera were tested using the Microscopic Agglutination Test (MAT) for antibodies against six live serogroups belonging to the Leptospira spp, with a cutoff point of ≥ 1:160. The prevalence of leptospiral antibodies was 29.96% in humans, 30.37% in cattle, 8.47% in goats, 28.95% in buffaloes, 20.29% in rodents and 9.09% in shrews. Additionally, one of the two samples in lions was seropositive. A significant difference in the prevalence P<0.05 was observed between cattle and goats. No significant difference in prevalence was observed with respect to age and sex in humans or any of the sampled animal species. The most prevalent serogroups with antibodies of Leptospira spp were Sejroe, Hebdomadis, Grippotyphosa, Icterohaemorrhagie and Australis, which were detected in humans, cattle, goats and buffaloes; Sejroe and Grippotyphosa, which were detected in a lion; Australis, Icterohaemorrhagie and Grippotyphosa, which were detected in rodents; and Australis, which was detected in shrews. Antibodies to serogroup Ballum were detected only in humans. Conclusions The results of this study demonstrate that leptospiral antibodies are widely prevalent in humans, livestock and wildlife from the Katavi-Rukwa ecosystem. The disease poses a serious economic and public health threat in the study area. This epidemiological study provides information on circulating serogroups, which will be essential in designing intervention measures to reduce the risk of disease transmission. PMID:25806825

Inhibition of monoacylglycerol lipase attenuates vomiting in Suncus murinus and 2-arachidonoyl glycerol attenuates nausea in rats

PubMed Central

Sticht, Martin A; Long, Jonathan Z; Rock, Erin M; Limebeer, Cheryl L; Mechoulam, Raphael; Cravatt, Benjamin F; Parker, Linda A

2012-01-01

BACKGROUND AND PURPOSE To evaluate the role of 2-arachidonoyl glycerol (2AG) in the regulation of nausea and vomiting using animal models of vomiting and of nausea-like behaviour (conditioned gaping). EXPERIMENTAL APPROACH Vomiting was assessed in shrews (Suncus murinus), pretreated with JZL184, a selective monoacylglycerol lipase (MAGL) inhibitor which elevates endogenous 2AG levels, 1 h before administering the emetogenic compound, LiCl. Regulation of nausea-like behaviour in rats by exogenous 2AG or its metabolite arachidonic acid (AA) was assessed, using the conditioned gaping model. The role of cannabinoid CB1 receptors, CB2 receptors and cyclooxygenase (COX) inhibition in suppression of vomiting or nausea-like behaviour was assessed. KEY RESULTS JZL184 dose-dependently suppressed vomiting in shrews, an effect prevented by pretreatment with the CB1 receptor inverse agonist/antagonist, AM251. In shrew brain tissue, JZL184 inhibited MAGL activity in vivo. In rats, 2AG suppressed LiCl-induced conditioned gaping but this effect was not prevented by AM251 or the CB2 receptor antagonist, AM630. Instead, the COX inhibitor, indomethacin, prevented suppression of conditioned gaping by 2AG or AA. However, when rats were pretreated with a high dose of JZL184 (40 mg·kg−1), suppression of gaping by 2AG was partially reversed by AM251. Suppression of conditioned gaping was not due to interference with learning because the same dose of 2AG did not modify the strength of conditioned freezing to a shock-paired tone. CONCLUSIONS AND IMPLICATIONS Our results suggest that manipulations that elevate 2AG may have anti-emetic or anti-nausea potential. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 PMID:21470205

Differences on the Root and Root Canal Morphologies between Asian and White Ethnic Groups Analyzed by Cone-beam Computed Tomography.

PubMed

Martins, Jorge N R; Gu, Yongchun; Marques, Duarte; Francisco, Helena; Caramês, João

2018-06-01

Populations from different geographic regions and ethnic backgrounds may present differences in dental morphology. The aim of this study was to compare the differences in root and root canal configurations on Asian and white subpopulations using cone-beam computed tomographic imaging. Information from Asian and white patients was retrieved from 2 cone-beam computed tomographic imaging databases in China and Western Europe. Two calibrated observers collected data regarding the number of roots and Vertucci root canal system configuration for all groups of teeth. A total of 15,655 teeth were analyzed. The z test for independent groups was used to analyze differences between the groups. The significance level was considered at a P value < .05. Reliability tests were performed between observers. Differences were noted in the number of roots per tooth in 6 groups of teeth. The Asian group showed a higher prevalence of single-root configurations in maxillary first premolars (83.2%) and mandibular second molars (45.4%) when compared with whites with 48.7% and 14.3%, respectively. Moreover, 3-rooted configurations in mandibular first molars were more common in Asians (25.9%) compared with whites (2.6%). Seventeen of the 20 analyzed roots had a higher prevalence of Vertucci type I configuration in Asians. Maxillary first molars with second mesiobuccal root canals were more commonly found in whites than in Asians (71.3% and 58.4%, respectively). A similar situation was found in maxillary second molars. The Asian ethnic group presented a higher prevalence of Vertucci type I configuration, whereas the white group displayed a higher number of multiple root canal system morphologies. A clinician should be aware of these differences when treating patients from these ethnic groups. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Elastomeric-ligated vs self-ligating appliances: a pilot study examining microbial colonization and white spot lesion formation after 1 year of orthodontic treatment.

PubMed

Buck, Tyson; Pellegrini, Peter; Sauerwein, Rebecca; Leo, Michael C; Covell, David A; Maier, Tom; Machida, Curtis A

2011-01-01

To (1) evaluate the use of adenosine triphosphate (ATP)-driven bioluminescence for quantification of total plaque bacteria in orthodontic patients, (2) compare plaque bacteria amounts at the bracket-tooth interface with use of elastomeric-ligated and self-ligating brackets after 1 year of orthodontic treatment, and (3) analyze formation of white spot lesions by photographic evaluation and laser-light fluorescence (DIAGNOdent). Thirteen subjects had fixed orthodontic appliances placed where lateral incisors were bonded with either elastomeric-ligated or self-ligating brackets. Plaque bacteria were collected from incisor surfaces after 1 year and quantified using plating methods and ATP-driven bioluminescence. White spot lesions were evaluated by photographic and DIAGNOdent determinations. A 2 x 2 x 2 mixed-design ANOVA was conducted to determine differences in plaque retention between elastomeric-ligated and self-ligating brackets. ATP-driven bioluminescence values correlated to numbers of total plaque bacteria (r = 0.80). However, unlike findings published in the original pilot study, which described increased plaque retention with elastomeric-ligated brackets at 5 weeks postbonding, there were no significant differences in bacterial numbers or ATP-driven bioluminescence values surrounding the elastomeric-ligated vs self-ligating brackets after 1 year of orthodontic treatment. Based on photographic and DIAGNOdent determinations, white spot lesions were found relatively equally on teeth bonded with either bracket type. DIAGNOdent measurements were found to have moderate sensitivity (0.71) and good specificity (0.88) when compared to white spot lesions determined using photographic evaluation. ATP-driven bioluminescence can be used as an accurate assessment of total plaque bacteria in orthodontic patients. After 1 year of orthodontic treatment for patients in this pilot study, there appeared to be no differences in retention of plaque bacteria or white spot lesions comparing the bracket types. The use of DIAGNOdent has some limitations, but may prove to be useful to monitor white spot lesions longitudinally.

Effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel: An in vitro study.

PubMed

Hernandé-Gatón, Patrícia; Palma-Dibb, Regina Guenka; Silva, Léa Assed Bezerra da; Faraoni, Juliana Jendiroba; de Queiroz, Alexandra Mussolino; Lucisano, Marília Pacífico; Silva, Raquel Assed Bezerra da; Nelson Filho, Paulo

2018-04-01

To evaluate the effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel. 40 tooth segments obtained from third molar crowns had the enamel surface divided into thirds, one of which was not subjected to toothbrushing. In the other two thirds, sound enamel and enamel with artificially induced white spot lesions were randomly assigned to four groups (n=10) : UT: ultrasonic toothbrush (Emmi-dental); ST1: sonic toothbrush (Colgate ProClinical Omron); ST2: sonic toothbrush (Sonicare Philips); and ROT: rotating-oscillating toothbrush (control) (Oral-B Professional Care Triumph 5000 with SmartGuide). The specimens were analyzed by confocal laser microscopy for surface roughness and wear. Data were analyzed statistically by paired t-tests, Kruskal-Wallis, two-way ANOVA and Tukey's post-test (α= 0.05). The different powered toothbrushing systems did not cause a significant increase in the surface roughness of sound enamel (P> 0.05). In the ROT group, the roughness of white spot lesion surface increased significantly after toothbrushing and differed from the UT group (P< 0.05). In the ROT group, brushing promoted a significantly greater wear of white spot lesion compared with sound enamel, and this group differed significantly from the ST1 group (P< 0.05). None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear. None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) tested caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear. Copyright©American Journal of Dentistry.

Functional tooth restoration utilising split germs through re-regionalisation of the tooth-forming field

PubMed Central

Yamamoto, Naomi; Oshima, Masamitsu; Tanaka, Chie; Ogawa, Miho; Nakajima, Kei; Ishida, Kentaro; Moriyama, Keiji; Tsuji, Takashi

2015-01-01

The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force. PMID:26673152

Evolution of high tooth replacement rates in sauropod dinosaurs.

PubMed

D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

2013-01-01

Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs

PubMed Central

Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

2013-01-01

Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs. PMID:23874921

Can they dig it? Functional morphology and semifossoriality among small-eared shrews, genus Cryptotis (Mammalia, Soricidae)

USGS Publications Warehouse

Woodman, Neal; Gaffney, Sarah A.

2014-01-01

Small-eared shrews (Mammalia: Soricidae: Cryptotis), exhibit modifications of the forelimb skeleton that have been interpreted as adaptations for semifossoriality. Most species inhabit remote regions, however, and their locomotory and foraging behaviors remain mostly speculative. To better understand the morphological modifications in the absence of direct observations, we quantified variation in these species by measuring 151 individuals representing 18 species and populations of Cryptotis and two species of moles (Talpidae) for comparison. From our measurements, we calculated 22 indices, most of which have been used previously to characterize substrate use among rodents and other taxa. We analyzed the indices using 1) average percentile ranks, 2) principal components analysis, and 3) cluster analysis. From these analyses, we determined that three basic modes of substrate adaptation are present within Cryptotis: 1) a primarily terrestrial mode, with species that are capable of burrowing, but lack adaptations to increase digging efficiency, 2) a semifossorial mode, with species whose forelimbs bones show strong muscle attachment areas and increased mechanical advantage, and 3) an intermediate mode. In addition to identifying new morphological characters and contributing to our understanding of the functional morphology of soricids, these analyses provide additional insight into the ecology of the species of interest.

A climate for speciation: rapid spatial diversification within the Sorex cinereus complex of shrews

USGS Publications Warehouse

Hope, Andrew G.; Speer, Kelly A.; Demboski, John R.; Talbot, Sandra L.; Cook, Joseph A.

2012-01-01

The cyclic climate regime of the late Quaternary caused dramatic environmental change at high latitudes. Although these events may have been brief in periodicity from an evolutionary standpoint, multiple episodes of allopatry and divergence have been implicated in rapid radiations of a number of organisms. Shrews of the Sorex cinereus complex have long challenged taxonomists due to similar morphology and parapatric geographic ranges. Here, multi-locus phylogenetic and demographic assessments using a coalescent framework were combined to investigate spatiotemporal evolution of 13 nominal species with a widespread distribution throughout North America and across Beringia into Siberia. For these species, we first test a hypothesis of recent differentiation in response to Pleistocene climate versus more ancient divergence that would coincide with pre-Pleistocene perturbations. We then investigate the processes driving diversification over multiple continents. Our genetic analyses highlight novel diversity within these morphologically conserved mammals and clarify relationships between geographic distribution and evolutionary history. Demography within and among species indicates both regional stability and rapid expansion. Ancestral ecological differentiation coincident with early cladogenesis within the complex enabled alternating and repeated episodes of allopatry and expansion where successive glacial and interglacial phases each promoted divergence. The Sorex cinereus complex constitutes a valuable model for future comparative assessments of evolution in response to cyclic environmental change.

Early Tertiary mammals from North Africa reinforce the molecular Afrotheria clade

PubMed Central

Tabuce, Rodolphe; Marivaux, Laurent; Adaci, Mohammed; Bensalah, Mustapha; Hartenberger, Jean-Louis; Mahboubi, Mohammed; Mebrouk, Fateh; Tafforeau, Paul; Jaeger, Jean-Jacques

2007-01-01

The phylogenetic pattern and timing of the radiation of mammals, especially the geographical origins of major crown clades, are areas of controversy among molecular biologists, morphologists and palaeontologists. Molecular phylogeneticists have identified an Afrotheria clade, which includes several taxa as different as tenrecs (Tenrecidae), golden moles (Chrysochloridae), elephant-shrews (Macroscelididae), aardvarks (Tubulidentata) and paenungulates (elephants, sea cows and hyracoids). Molecular data also suggest a Cretaceous African origin for Afrotheria within Placentalia followed by a long period of endemic evolution on the Afro-Arabian continent after the mid-Cretaceous Gondwanan breakup (approx. 105–25 Myr ago). However, there was no morphological support for such a natural grouping so far. Here, we report new dental and postcranial evidence of Eocene stem hyrax and macroscelidid from North Africa that, for the first time, provides a congruent phylogenetic view with the molecular Afrotheria clade. These new fossils imply, however, substantial changes regarding the historical biogeography of afrotheres. Their long period of isolation in Africa, as assumed by molecular inferences, is now to be reconsidered inasmuch as Eocene paenungulates and elephant-shrews are here found to be related to some Early Tertiary Euramerican ‘hyopsodontid condylarths’ (archaic hoofed mammals). As a result, stem members of afrotherian clades are not strictly African but also include some Early Paleogene Holarctic mammals. PMID:17329227

Distributions of vesicular glutamate transporters 1 and 2 in the visual system of tree shrews (Tupaia belangeri)1

PubMed Central

Balaram, P; Isaamullah, M; Petry, HM; Bickford, ME; Kaas, JH

2014-01-01

Vesicular glutamate transporter (VGLUT) proteins regulate the storage and release of glutamate from synapses of excitatory neurons. Two isoforms, VGLUT1 and VGLUT2, are found in most glutamatergic projections across the mammalian visual system, and appear to differentially identify subsets of excitatory projections between visual structures. To expand current knowledge on the distribution of VGLUT isoforms in highly visual mammals, we examined the mRNA and protein expression patterns of VGLUT1 and VGLUT2 in the lateral geniculate nucleus (LGN), superior colliculus, pulvinar complex, and primary visual cortex (V1) in tree shrews (Tupaia belangeri), which are closely related to primates but classified as a separate order (Scandentia). We found that VGLUT1 was distributed in intrinsic and corticothalamic connections, whereas VGLUT2 was predominantly distributed in subcortical and thalamocortical connections. VGLUT1 and VGLUT2 were coexpressed in the LGN and in the pulvinar complex, as well as in restricted layers of V1, suggesting a greater heterogeneity in the range of efferent glutamatergic projections from these structures. These findings provide further evidence that VGLUT1 and VGLUT2 identify distinct populations of excitatory neurons in visual brain structures across mammals. Observed variations in individual projections may highlight the evolution of these connections through the mammalian lineage. PMID:25521420

Effects of different types of tooth movement and force magnitudes on the amount of tooth movement and root resorption in rats.

PubMed

Nakano, Takako; Hotokezaka, Hitoshi; Hashimoto, Megumi; Sirisoontorn, Irin; Arita, Kotaro; Kurohama, Takeshi; Darendeliler, M Ali; Yoshida, Noriaki

2014-11-01

To investigate differences in the amount of tooth movement and root resorption that occurred after tipping and bodily movement of the maxillary first molar in rats. Ten-week-old female Wistar rats were divided into two groups according to type of tooth movement and subdivided into four subgroups according to the magnitude of applied force. Nickel-titanium closed-coil springs exerting forces of 10, 25, 50, or 100 g were applied to the maxillary left first molars to induce mesial tooth movement. We designed a novel orthodontic appliance for bodily tooth movement. Tooth movement distance and root resorption were measured using microcomputed tomography and scanning electron and scanning laser microscopy. The amount of tooth movement in the bodily tooth movement group was less than half that in the tipping tooth movement group. The greatest amount of tooth movement occurred in the 10-g tipping and 50-g bodily tooth movement subgroups, and the amount of tooth movement decreased with the application of an excessive magnitude of force. Conversely, root resorption increased when the heavier orthodontic force was applied in both groups. Root resorption in the tipping tooth movement group was approximately twice that in the bodily tooth movement group. Root resorption in the tipping tooth movement group was more pronounced than that in the bodily tooth movement group. Although the amount of tooth movement decreased when extremely heavy forces were applied, root resorption increased in both the tipping and bodily tooth movement groups in rats.

Clinical efficacy of a bleaching enzyme-based toothpaste. A double-blind controlled clinical trial.

PubMed

Llena, Carmen; Oteo, Carlos; Oteo, Jesús; Amengual, José; Forner, Leopoldo

2016-01-01

To assess the efficacy of a bleaching enzyme-based toothpaste. A randomized clinical trial was carried out, comprising 48 participants with teeth exhibiting color A3 or higher according to the Vita Classical guide. One-half of the sample received the bleaching enzyme-based toothpaste (White Kin(®)), while the other received placebo toothpaste. Both products were supplied in identical containers and had the same composition except for the active components. The teeth color was measured with a spectrophotometer. The patients were instructed to brush their teeth three times a day during 3 min with the assigned product, during 12 weeks. The color measurements were repeated after 3, 6, 9 and 12 weeks of treatment. Color variation was based on the CIE L*a*b* coordinates, ΔE and the EW index. The relationship of these variables at different observation times were performed using a generalized estimating equations model, which evaluated the effect of treatment, time and interaction. The patients using the bleaching enzyme-based toothpaste showed an increase in lightness (80.14 -treatment- versus 79.25 -control group-) and a reduction in component b*. ΔE was found higher in the treatment group (p=0.064), close to statistical significance. The bleaching enzyme-based toothpaste could be potentially efficient in the modification in tooth color progressing from the third to ninth week of treatment, tending to stabilize after the ninth week. A very low carbamide peroxide concentration, with the incorporation of lactoperoxidase, tooth paste, tends to offer clinically satisfactory results, in terms of modifications in tooth color, nevertheless no significant differences were founded when compared to the control group, with an oral hygiene controlled along the study. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of blood and saliva contamination on bond strength of brackets bonded with a protective liquid polish and a light-cured adhesive.

PubMed

Sayinsu, Korkmaz; Isik, Fulya; Sezen, Serdar; Aydemir, Bulent

2007-03-01

The application of a polymer coating to the labial enamel tooth surface before bonding can help keep white spot lesions from forming. Previous studies evaluating the effects of blood and saliva contamination on the bond strengths of light-cured composites showed significant reductions in bond strength values. The purpose of this study was to investigate whether the bond strength of a light-cured system (Transbond XT, 3M Unitek, Puchheim, Germany) used with a liquid polish (BisCover, Bisco, Schaumburg, Ill) is affected by contamination with blood or saliva. One hundred twenty permanent human premolars were randomly divided into 6 groups of 20. Various enamel surface conditions were studied: dry, blood contaminated, and saliva contaminated. A light-cured bonding system (Transbond XT) was used in all groups. The teeth in group 1 were bonded with Transbond XT. In the second group, BisCover polymeric resin polish was applied on the etched tooth surfaces before the brackets were bonded with Transbond XT resin. Comparison of the first and second groups showed no statistically significant difference. Groups 3 through 6 were bonded without Transbond XT. For groups 3 and 5, a layer of blood or saliva, respectively, was applied to the etched enamel followed by BisCover. In groups 4 and 6, blood or saliva, respectively, was applied on the light-cured BisCover. Shear forces were applied to the samples with a universal testing machine, and bond strengths were measured in megapascals. The protective liquid polish (BisCover) layer did not affect bond strength. Blood contamination on acid-etched surfaces affects bond strength more than saliva contamination. When a protective liquid polish (BisCover) is applied to the tooth surface, the effect of contamination by blood or saliva is prevented.

Biomaterial Selection for Tooth Regeneration

PubMed Central

Yuan, Zhenglin; Nie, Hemin; Wang, Shuang; Lee, Chang Hun; Li, Ang; Fu, Susan Y.; Zhou, Hong

2011-01-01

Biomaterials are native or synthetic polymers that act as carriers for drug delivery or scaffolds for tissue regeneration. When implanted in vivo, biomaterials should be nontoxic and exert intended functions. For tooth regeneration, biomaterials have primarily served as a scaffold for (1) transplanted stem cells and/or (2) recruitment of endogenous stem cells. This article critically synthesizes our knowledge of biomaterial use in tooth regeneration, including the selection of native and/or synthetic polymers, three-dimensional scaffold fabrication, stem cell transplantation, and stem cell homing. A tooth is a complex biological organ. Tooth loss represents the most common organ failure. Tooth regeneration encompasses not only regrowth of an entire tooth as an organ, but also biological restoration of individual components of the tooth including enamel, dentin, cementum, or dental pulp. Regeneration of tooth root represents perhaps more near-term opportunities than the regeneration of the whole tooth. In the adult, a tooth owes its biological vitality, arguably more, to the root than the crown. Biomaterials are indispensible for the regeneration of tooth root, tooth crown, dental pulp, or an entire tooth. PMID:21699433

[Assessment of antibacterial efficacy of ozone therapy in treatment of caries at the white spot stage].

PubMed

Makeeva, I M; Turkina, A Yu; Margaryan, E G; Paramonov, Yu O; Polyakova, M A

Effect on cariogenic flora is the key toremineralizing therapy efficacy in treatment of initial caries (at the white spot stage). Ozone in dentistry is used as a highly effective antibacterial agent. Treatment of white spot lesions with the ozone-air mixture leads to significant increase of efficacy in non-invasive treatment of initial caries. clinical and microbiological assessment of antibacterial efficacy of ozone therapy in treatment of caries at the white spot stage. The trial recruited 86 patients for non-invasive treatment of caries at the white spot stage which included the complex of professional oral hygiene, medicamental treatment of white spot lesions with hydrogen peroxide 3% and chlorhexidinedigluconate 0,2%, treatment with the ozone-air mixture and application of hydroxyapatite Са2+. Material for microbiological study was received before the treatment, after the complex of professional oral hygiene and medicamental treatment of white spot lesions conducted as well as after the treatment with the ozone-air mixture. Before the treatment up to 16 kinds of microorganisms on the surface of white spot lesion were detected with the following shares: S. mutans (19.9%), S. salivarius (15.1%), S. epidermidis (8.7%), S. mitis (6.5%), Lactobacillus (6.5%) and different kinds of staphylococci (10.8%). After the complex of professional oral hygiene and medicamental treatment conducted decrease in number of cariogenic microorganisms was indicated as follows: S. mutans - from 1·105 to 1·104, S. salivarius - from 1·107 to 1·106, S. epidermidis - from 1·105 to 1·104, S. mitis - from 1·104 to 1·103, Lactobacillus - from 1·104 tо 1·103. After the treatment of tooth enamel with the ozone-air mixture increase in microorganisms was not observed. The efficacy of ozone on cariogenic microorganisms exceeds significantly the efficacy of 3% hydrogen peroxide and 0,2% chlorhexidinedigluconate. It is strongly advisable to include ozone in protocol of non-invasive treatment of initial dental caries.

Prostaglandin PGE2: a possible mechanism for bone destruction in calcinosis circumscripta.

PubMed

Caniggia, A; Gennari, C; Vattimo, A; Runci, F; Bombardieri, S

1978-02-28

A patient showed evident osteolysis in phalanges and heavy periarticular calcium deposits of the fingers, wrists and toes which avidly took up 47Ca. The dense, white, tooth-paste like fluid contained in the periarticular calcium deposits has been studied by two different X-ray diffraction methods, by Ubatuba's bioassay for prostaglandin, by thin layer chromatography and by mass spectrometry. The calcium deposits were hydroxyapatite and prostaglandin PGE2 was detected in them. The bone resorption stimulating activity of PGE2 would be expected to result in increased bone destruction with release of calcium salts and this could be a working hypothesis of the pathogenesis of calcinosis circumscripta.

Assessment of White Spot Lesions and In-Vivo Evaluation of the Effect of CPP-ACP on White Spot Lesions in Permanent Molars of Children

PubMed Central

Munjal, Deepti; Garg, Shalini; Dhindsa, Abhishek; Sidhu, Gagandeep Kaur

2016-01-01

Introduction As hindrance of remineralisation process occurs during orthodontic therapy resulting in decalcification of enamel because number of plaque retention sites increases due to banding and bonding of appliances to teeth. Aim The present analytic study was undertaken to assess the occurrence of white spot lesions in permanent molars of children with and without orthodontic therapy and to evaluate the effect of Casein PhosphoPeptide-Amorphous Calcium Phosphate (CPP-ACP) on white spot lesions in post-orthodontic patients in a given period of time. Materials and Methods The study comprised of examination of 679 first permanent molars which were examined to assess the occurrence of smooth surface white spot lesions in children of 8 to 16 years age group. Group I comprised subjects without any orthodontic treatment and Group II comprised of subjects who had undergone orthodontic therapy. The sample size was calculated using the epi-info6 computer package. Treatment group included 20 post-orthodontic patients examined with at least one white spot lesion within the enamel who received remineralizing cream (GC Tooth Mousse, Recaldent, GC Corporation.) i.e., CPP–ACP cream two times a day for 12 consecutive weeks. Computerized image analysis method was taken to evaluate white spot lesions. These frequency and percentages were compared with chi-square test. For comparison of numeric data, paired t-test was used. Results Of the total 278 (49.6%) first permanent molars showed occurrence of smooth surface white spot lesions out of 560 in Group I and 107 (89.9%) first permanent molars showed presence of white spot lesions out of 119 debanded first permanent molars of children examined in Group II. CPP-ACP therapy group showed reduction in severity of codes which was found to be highly significant after 12 weeks and eight weeks on gingival-third, p-value (<0.001) and significant after eight weeks and four weeks on middle-third according to ICDAS II criteria and computerized image analysis. Conclusion CPP-ACP therapy minimum for 12 weeks is highly recommended as post-orthodontic treatment need in management of smooth surface white spot lesions on teeth undergoing fixed orthodontic therapy according to the present study. PMID:27437352

The prevalence of tooth discolouration and the self-satisfaction with tooth colour in a Chinese urban population.

PubMed

Xiao, J; Zhou, X D; Zhu, W C; Zhang, B; Li, J Y; Xu, X

2007-05-01

To determine the prevalence of tooth discolouration, self-satisfaction with tooth colour, and correlation with socio-demographic-behavioural factors in adults and teenagers in Chengdu, China. A cross-sectional survey. 405 Chinese urban adults and teenagers from a multistage random probability sample. Tooth colour was measured on the maxillary central incisors using a colorimeter. Tooth discolouration was determined according to the discolouration level figure and evaluation criteria. Self-satisfaction with tooth colour was assessed on a five-point qualitative scale. Data were coded and analyzed using SPSS software. The mean values for L*, a* and b* were 70.67 (s.d. 1.91), 4.29 (s.d. 2.05) and 17.51 (s.d. 4.13), respectively. Age and sex were the most important factors associated with tooth colour (P < 0.05). About half of the study population (48.9%) suffered from some tooth discolouration, and 52.6% were dissatisfied with their tooth colour. Education and smoking were significant factors affecting self-satisfaction with tooth colour (P < 0.05). Tooth discolouration is common among the Chinese, and many Chinese are dissatisfied with their tooth colour. Self-satisfaction with tooth colour decreased with increasing severity of discolouration. Further research is needed to determine types of tooth discolouration among broader regions in China.

[Effect of a tooth-brushing education program on oral health of preschool children].

PubMed

Kang, Bok-Hee; Park, Sun-Nam; Sohng, Kyeong-Yae; Moon, Jung-Soon

2008-12-01

To examine the effect of tooth-brushing education on the oral health of preschoolers. A quasi-experimental design with a non-equivalent control group was used. Two kindergartens were selected and 39 preschoolers from one kindergarten were assigned to the experimental group with tooth-brushing education and 39 from the other kindergarten to the control group. The tooth-brushing education program included 1 session on oral health education, individual tooth-brushing instruction for 1 week and supervised tooth-brushing after lunch for 4 weeks. Oral health behavior including use of tooth paste, tooth-brushing time and method of tooth-brushing, plague, streptococcus mutans, lactobacillus and dental caries were measured before and after the education. Fisher's exact test, t-test and paired t-test with the Window SAS 9.1 program were used to analyze the data. A significant increase in the use of tooth paste, tooth-brushing time and the practice of correct tooth-brushing and a decrease in plague and development of dental caries were observed in the experimental group. This tooth-brushing education was partially effective in improving oral health of preschoolers.

Bioengineered Tooth Buds Exhibit Features of Natural Tooth Buds.

PubMed

Smith, E E; Angstadt, S; Monteiro, N; Zhang, W; Khademhosseini, A; Yelick, P C

2018-06-01

Tooth loss is a significant health issue currently affecting millions of people worldwide. Artificial dental implants, the current gold standard tooth replacement therapy, do not exhibit many properties of natural teeth and can be associated with complications leading to implant failure. Here we propose bioengineered tooth buds as a superior alternative tooth replacement therapy. We describe improved methods to create highly cellularized bioengineered tooth bud constructs that formed hallmark features that resemble natural tooth buds such as the dental epithelial stem cell niche, enamel knot signaling centers, transient amplifying cells, and mineralized dental tissue formation. These constructs were composed of postnatal dental cells encapsulated within a hydrogel material that were implanted subcutaneously into immunocompromised rats. To our knowledge, this is the first report describing the use of postnatal dental cells to create bioengineered tooth buds that exhibit evidence of these features of natural tooth development. We propose future bioengineered tooth buds as a promising, clinically relevant tooth replacement therapy.

Assessment of color stability of white mineral trioxide aggregate angelus and bismuth oxide in contact with tooth structure.

PubMed

Marciano, Marina Angélica; Costa, Reginaldo Mendonça; Camilleri, Josette; Mondelli, Rafael Francisco Lia; Guimarães, Bruno Martini; Duarte, Marco Antonio Hungaro

2014-08-01

Dental discoloration with use of materials containing bismuth oxide has been reported. It is postulated that the discoloration is a result of chemical interaction of bismuth oxide with dentin. The aim of the study was to analyze dental color alteration and the chemical interaction of bismuth oxide with the main components present in composite (methacrylate) and in dentin (collagen). Fifty bovine teeth were prepared and filled with white mineral trioxide aggregate (MTA) Angelus, Portland cement (PC) with 20% zirconium oxide, or PC with 20% calcium tungstate and then sealed with composite. Triple antibiotic paste and unfilled samples were the positive and negative controls, respectively. The specimens were stored in separate flasks immersed in tap water at 37°C with ambient light blocked out. The color assessment was performed with a spectrophotometer at different intervals, namely before filling and 24 hours, 15 days, and 30 days after filling. The color change and the luminosity were calculated. The statistical analysis was performed by using nonparametric Kruskal-Wallis and Dunn tests (P < .05). The interaction of the bismuth oxide, zirconium oxide, and calcium tungstate with collagen and methacrylate was assessed by placing the materials in contact, followed by color assessment. The analysis of color change values showed that all the materials presented color alteration after the evaluated periods. Statistically higher luminosity was verified for PC/20% zirconium oxide in comparison with white MTA Angelus (P < .05). The teeth filled with white MTA Angelus demonstrated a grayish discoloration with evident dentin staining. Bismuth oxide exhibited a color change when in contact with collagen. The color of white MTA Angelus was altered in contact with dental structures. Collagen, which is present in dentin matrix, reacted with bismuth oxide, resulting in a grayish discoloration. The use of an alternative radiopacifier to replace bismuth in white MTA is indicated. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Rickettsial Infections of Fleas Collected From Small Mammals on Four Islands in Indonesia

DTIC Science & Technology

2010-01-01

cheopis from shrews ( Suncus murinus). X. cheopis were pooled and tested for DNA from rickettsial agents Rickettsia typhi, Rickettsia felis, and spotted...fever group rickettsiae . R. typhi, the agent of murine typhus, was detected in X. cheopis collected from small mammals in West Java and East...Kalimantan. R.felis was detected in X. cheopis collected from small mammals in Manado, North Sulawesi. R. felis and spotted fever group rickettsiae were

[Tooth wear, a proposal for an evaluation system].

PubMed

Wetselaar, P; van der Zaag, J; Lobbezoo, F

2011-06-01

The present-day terminology and definitions of tooth wear are not unambiguous. For diagnosing tooth wear, however, it is essential that they are unambiguous. In this article a proposal is presented for a tooth wear evaluation system with simplified definitions. This system consists ofa number of modules and can be used for various aspects of the diagnostic procedure. It can be used for the quantification of tooth wear, both for periodic screening and for the monitoring of tooth wear in individual patients. The scoring of occlusal/incisal tooth wear as well as of non-occlusal/non-incisal tooth wear is possible. The evaluative system is also suitable for determining which type of tooth wear, such as attrition, abrasion and erosion, is most likely to have caused any observed loss of hard tooth tissue.

Evaluation of a 6% hydrogen peroxide tooth whitening gel on enamel and dentine microhardness in vitro.

PubMed

Joiner, Andrew; Thakker, Gopal; Cooper, Yvonne

2004-01-01

The aims of this study were to evaluate the effects of a novel 6% hydrogen peroxide containing tooth whitener, Xtra White (XW), on enamel and dentine microhardness in vitro. Polished human enamel and dentine specimens were prepared and baseline microhardness determined. In study 1, enamel specimens were exposed to 20 min cycles of either water, XW or Sprite Light for up to 28 cycles. In studies 2 and 3, enamel specimens were treated with 20 min cycles of either XW or water and exposed to whole saliva at all other times. In study 3, an additional exposure to a fluoride containing toothpaste was conducted. In total, 28 treatments were conducted in order to simulate a 2 weeks product use. In study 4, dentine specimens were treated as per study 3. Final microhardness measurements were taken and for studies 3 and 4 colour measurements were additionally taken. XW and water gave no statistically significant (p>0.05) changes in enamel and dentine microhardness after 28 treatments. Sprite Light gave a significant (p<0.00002) reduction in enamel microhardness after one 20 min treatment. XW showed significant bleaching of enamel and dentine specimens as compared to the water control. XW does not have any significant effect on enamel and dentine microhardness.

Estimating ages of white-tailed deer: Age and sex patterns of error using tooth wear-and-replacement and consistency of cementum annuli

USGS Publications Warehouse

Samuel, Michael D.; Storm, Daniel J.; Rolley, Robert E.; Beissel, Thomas; Richards, Bryan J.; Van Deelen, Timothy R.

2014-01-01

The age structure of harvested animals provides the basis for many demographic analyses. Ages of harvested white-tailed deer (Odocoileus virginianus) and other ungulates often are estimated by evaluating replacement and wear patterns of teeth, which is subjective and error-prone. Few previous studies however, examined age- and sex-specific error rates. Counting cementum annuli of incisors is an alternative, more accurate method of estimating age, but factors that influence consistency of cementum annuli counts are poorly known. We estimated age of 1,261 adult (≥1.5 yr old) white-tailed deer harvested in Wisconsin and Illinois (USA; 2005–2008) using both wear-and-replacement and cementum annuli. We compared cementum annuli with wear-and-replacement estimates to assess misclassification rates by sex and age. Wear-and-replacement for estimating ages of white-tailed deer resulted in substantial misclassification compared with cementum annuli. Age classes of females were consistently underestimated, while those of males were underestimated for younger age classes but overestimated for older age classes. Misclassification resulted in an impression of a younger age-structure than actually was the case. Additionally, we obtained paired age-estimates from cementum annuli for 295 deer. Consistency of paired cementum annuli age-estimates decreased with age, was lower in females than males, and decreased as age estimates became less certain. Our results indicated that errors in the wear-and-replacement techniques are substantial and could impact demographic analyses that use age-structure information. 

Positioning the actual interference fringe pattern on the tooth flank in measuring gear tooth flanks by laser interferometry

NASA Astrophysics Data System (ADS)

Fang, Suping; Wang, Leijie; Liu, Shiqiao; Komori, Masaharu; Kubo, Aizoh

2011-05-01

In measuring form deviation of gear tooth flanks by laser interferometry, the collected interference fringe pattern (IFP) is badly distorted, in the case of shape, relative to the actual tooth flank. Meanwhile, a clear and definite mapping relationship between the collected IFP and the actual tooth flank is indispensable for both transforming phase differences into deviation values and positioning the measurement result on the actual tooth flank. In order to solve these problems, this paper proposes a method using the simulation tooth image as a bridge connecting the actual tooth flank and the collected IFP. The mapping relationship between the simulation tooth image and the actual tooth flank has been obtained by ray tracing methods [Fang et al., Appl. Opt. 49(33), 6409-6415 (2010)]. This paper mainly discusses how to build the relationship between the simulation tooth image and the collected IFP by using a matching algorithm of two characteristic point sets. With the combination of the two above-mentioned assistant mapping relationships, the mapping relationship between the collected IFP and the actual tooth flank can be built; the collected IFP can be positioned on the actual tooth flank. Finally, the proposed method is employed in a measurement of the form deviation of a gear tooth flank and the result proves the feasibility of the proposed method.

Correlation of panoramic radiography and cone beam CT findings in the assessment of the relationship between impacted mandibular third molars and the mandibular canal

PubMed Central

Neves, F S; Souza, T C; Almeida, S M; Haiter-Neto, F; Freitas, D Q; Bóscolo, F N

2012-01-01

Objectives The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images. Methods The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated. Results Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05). Conclusion Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case. PMID:22282507

Effectiveness of a new dentifrice with baking soda and peroxide in removing extrinsic stain and whitening teeth.

PubMed

Ghassemi, A; Hooper, W; Vorwerk, L; Domke, T; DeSciscio, P; Nathoo, S

2012-01-01

The primary purpose of this randomized, controlled, six-week clinical trial was to determine the effectiveness and safety of a new whitening dentifrice in removing extrinsic tooth stain and whitening teeth. An additional two-week exploratory study was conducted to determine whether the whitening or stain-prevention activity of the dentifrice would persist following cessation of use. In the first study (Phase I), one-hundred and forty-six qualifying subjects were randomly assigned to either a sodium bicarbonate whitening dentifrice group (Arm & Hammer Advance White Extreme Whitening Baking Soda and Peroxide Toothpaste) or a silica-based negative control dentifrice group, and brushed twice daily with their assigned dentifrice for six weeks. Tooth shade on the labial surfaces of the eight incisors was assessed using a Vita Classic shade guide, and extrinsic tooth stain was scored using a Modified Lobene Stain Index (MLSI) at baseline, week 4, and week 6. In Phase II (after the week 6 examination), volunteers from the Arm & Hammer whitening dentifrice group were randomly assigned to continue using the whitening dentifrice or to use the negative control dentifrice twice daily for two weeks. The six-week shade and stain index scores served as the baseline for this exploratory phase and were rescored after two weeks. The whitening dentifrice group had statistically significant (p < 0.0001) mean shade score reductions of 1.82 and 2.57 from baseline to weeks 4 and 6, respectively. For the same periods, the negative control dentifrice group was virtually unchanged from baseline. For tooth stain, the MLSI total mean scores for the whitening dentifrice group showed statistically significant (p < 0.0001) decreases from baseline of 1.42 (41.6%) and 2.11 (61.6%) at weeks 4 and 6, respectively. In contrast, the negative control dentifrice group had a MLSI reduction of 0.07 at week 4 and a 0.06 increase at week 6. Between-group analyses using baseline-adjusted ANCOVA showed the whitening dentifrice to be statistically significantly more effective (p < 0.0001) than the negative control for shade and tooth stain reductions for all index comparisons. Compared to the six-week (baseline) scores, subjects who continued to use the whitening dentifrice for the additional two weeks experienced statistically significant (p < 0.0001) further mean reductions of 0.88 in shade score and 0.46 in MLSI score, while subjects who switched to the negative control dentifrice experienced smaller, statistically significant (p < 0.05) reductions of 0.34 in shade score and 0.13 in total MLSI score. The Arm & Hammer whitening dentifrice tested in this study is effective for removing extrinsic tooth stain and whitening teeth. While the results also suggest that this dentifrice may have stain-prevention activity that persists following cessation of product use, such activity would need to be confirmed with further studies.

Satisfaction with appearance and the desired treatment to improve aesthetics.

PubMed

Al-Zarea, Bader K

2013-01-01

Objective. To identify participants' satisfaction with appearance and the desired treatment to improve aesthetics. Materials and Methods. 220 participants (127 males and 93 females, mean age = 21.4 ± 1.5 years) were recruited into the study. A structured questionnaire was used to assess patients' satisfaction with appearance and what treatment they desire to improve aesthetics. Participants scored the level of satisfaction with appearance using visual analogue scale. Results. The VAS mean score of satisfaction with general appearance was 6.8 ± 2.3. Half participants were dissatisfied with tooth appearance and 65.9% were dissatisfied with tooth colour. Higher VAS scores were associated with higher desire for all treatments that improve tooth appearance (P < .05). Dissatisfaction with tooth appearance increased with increased dissatisfaction with teeth colour, feeling of poor tooth alignment, presence of fractured anterior teeth, and increased desire for orthodontic, crowns, and dentures treatments (P < .05). Dissatisfaction with tooth colour was associated with increased desire for tooth whitening and tooth coloured fillings (P < .05). Conclusions. Participants had high levels of dissatisfaction with tooth appearance and tooth colour. Dissatisfaction with tooth colour contributed to the increased dissatisfaction with tooth appearance. Dissatisfaction with tooth appearance, colour, alignment, and condition was significantly related to high desire for aesthetic treatments.

A numerical algorithm of tooth profile of non-circular cylindrical gear

NASA Astrophysics Data System (ADS)

Wang, Xuan

2017-08-01

Non-circular cylindrical gear (NCCG) is a common form of non-circular gear. Different from the circular gear, the tooth profile equation of NCCG cannot be obtained. So it is necessary to use a numerical algorithm to calculate the tooth profile of NCCG. For this reason, this paper presents a simple and highly efficient numerical algorithm to obtain the tooth profile of NCCG. Firstly, the mathematical model of tooth profile envelope of NCCG is established based on the principle of gear shaping, and the tooth profile envelope of NCCG is obtained. Secondly, the polar radius and polar angle of shaper cutter tooth profile are chosen as the criterions, by which the points of NCCG tooth cogging can be screened out. Finally, the boundary of tooth cogging points is extracted by a distance criterion and correspondingly the tooth profile of NCCG is obtained.

Practical whole-tooth restoration utilizing autologous bioengineered tooth germ transplantation in a postnatal canine model

PubMed Central

Ono, Mitsuaki; Oshima, Masamitsu; Ogawa, Miho; Sonoyama, Wataru; Hara, Emilio Satoshi; Oida, Yasutaka; Shinkawa, Shigehiko; Nakajima, Ryu; Mine, Atsushi; Hayano, Satoru; Fukumoto, Satoshi; Kasugai, Shohei; Yamaguchi, Akira; Tsuji, Takashi; Kuboki, Takuo

2017-01-01

Whole-organ regeneration has great potential for the replacement of dysfunctional organs through the reconstruction of a fully functional bioengineered organ using three-dimensional cell manipulation in vitro. Recently, many basic studies of whole-tooth replacement using three-dimensional cell manipulation have been conducted in a mouse model. Further evidence of the practical application to human medicine is required to demonstrate tooth restoration by reconstructing bioengineered tooth germ using a postnatal large-animal model. Herein, we demonstrate functional tooth restoration through the autologous transplantation of bioengineered tooth germ in a postnatal canine model. The bioengineered tooth, which was reconstructed using permanent tooth germ cells, erupted into the jawbone after autologous transplantation and achieved physiological function equivalent to that of a natural tooth. This study represents a substantial advancement in whole-organ replacement therapy through the transplantation of bioengineered organ germ as a practical model for future clinical regenerative medicine. PMID:28300208

Tooth-meshing-harmonic static-transmission-error amplitudes of helical gears

NASA Astrophysics Data System (ADS)

Mark, William D.

2018-01-01

The static transmission errors of meshing gear pairs arise from deviations of loaded tooth working surfaces from equispaced perfect involute surfaces. Such deviations consist of tooth-pair elastic deformations and geometric deviations (modifications) of tooth working surfaces. To a very good approximation, the static-transmission-error tooth-meshing-harmonic amplitudes of helical gears are herein expressed by superposition of Fourier transforms of the quantities: (1) the combination of tooth-pair elastic deformations and geometric tooth-pair modifications and (2) fractional mesh-stiffness fluctuations, each quantity (1) and (2) expressed as a function of involute "roll distance." Normalization of the total roll-distance single-tooth contact span to unity allows tooth-meshing-harmonic amplitudes to be computed for different shapes of the above-described quantities (1) and (2). Tooth-meshing harmonics p = 1, 2, … are shown to occur at Fourier-transform harmonic values of Qp, p = 1, 2, …, where Q is the actual (total) contact ratio, thereby verifying its importance in minimizing transmission-error tooth-meshing-harmonic amplitudes. Two individual shapes and two series of shapes of the quantities (1) and (2) are chosen to illustrate a wide variety of shapes. In most cases representative of helical gears, tooth-meshing-harmonic values p = 1, 2, … are shown to occur in Fourier-transform harmonic regions governed by discontinuities arising from tooth-pair-contact initiation and termination, thereby showing the importance of minimizing such discontinuities. Plots and analytical expressions for all such Fourier transforms are presented, thereby illustrating the effects of various types of tooth-working-surface modifications and tooth-pair stiffnesses on transmission-error generation.

Social ranking effects on tooth-brushing behaviour.

PubMed

Maltby, John; Paterson, Kevin; Day, Liz; Jones, Ceri; Kinnear, Hayley; Buchanan, Heather

2016-05-01

A tooth-brushing social rank hypothesis is tested suggesting tooth-brushing duration is influenced when individuals position their behaviour in a rank when comparing their behaviour with other individuals. Study 1 used a correlation design, Study 2 used a semi-experimental design, and Study 3 used a randomized intervention design to examine the tooth-brushing social rank hypothesis in terms of self-reported attitudes, cognitions, and behaviour towards tooth-brushing duration. Study 1 surveyed participants to examine whether the perceived health benefits of tooth-brushing duration could be predicted from the ranking of each person's tooth-brushing duration. Study 2 tested whether manipulating the rank position of the tooth-brushing duration influenced participant-perceived health benefits of tooth-brushing duration. Study 3 used a longitudinal intervention method to examine whether messages relating to the rank positions of tooth-brushing durations causally influenced the self-report tooth-brushing duration. Study 1 demonstrates that perceptions of the health benefits from tooth-brushing duration are predicted by the perceptions of how that behaviour ranks in comparison to other people's behaviour. Study 2 demonstrates that the perceptions of the health benefits of tooth-brushing duration can be manipulated experimentally by changing the ranked position of a person's tooth-brushing duration. Study 3 experimentally demonstrates the possibility of increasing the length of time for which individuals clean their teeth by focusing on how they rank among their peers in terms of tooth-brushing duration. The effectiveness of interventions using social-ranking methods relative to those that emphasize comparisons made against group averages or normative guidelines are discussed. What is already known on this subject? Individual make judgements based on social rank information. Social rank information has been shown to influence positive health behaviours such as exercise. What does this study add? The health benefits of tooth-brushing are predicted by how tooth-brushing duration ranks within a distribution. Focussing on how teeth-cleaning duration ranks among others produces longer teeth-cleaning durations. © 2015 The British Psychological Society.

A numerical simulation of tooth movement by wire bending.

PubMed

Kojima, Yukio; Fukui, Hisao

2006-10-01

In orthodontic treatment, wires are bent and attached to teeth to move them via elastic recovery. To predict how a tooth will move, the initial force system produced from the wire is calculated. However, the initial force system changes as the tooth moves and may not be used to predict the final tooth position. The purpose of this study was to develop a comprehensive mechanical, 3-dimensional, numerical model for predicting tooth movement. Tooth movements produced by wire bending were simulated numerically. The teeth moved as a result of bone remodeling, which occurs in proportion to stress in the periodontal ligament. With an off-center bend, a tooth near the bending position was subjected to a large moment and tipped more noticeably than the other teeth. Also, a tooth far from the bending position moved slightly in the mesial or the distal direction. With the center V-bend, when the second molar was added as an anchor tooth, the tipping angle and the intrusion of the canine increased, and movement of the first molar was prevented. When a wire with an inverse curve of Spee was placed in the mandibular arch, the calculated tendency of vertical tooth movements was the same as the measured result. In these tooth movements, the initial force system changed as the teeth moved. Tooth movement was influenced by the size of the root surface area. Tooth movements produced by wire bending could be estimated. It was difficult to predict final tooth positions from the initial force system.

MAC/FAC: A Model of Similarity-Based Retrieval

DTIC Science & Technology

1994-10-01

Grapes (0.28) 327 Sour Grapes, analog The Taming of the Shrew (0.22), Merry Wives 251 (0.18), S[11 stories], Sour Grapes (-0.19) Sour Grapes, literal... The Institute for the 0 1 Learning Sciences Northwestern University CD• 00 MAC/FAC: A MODEL OF SIMILARITY-BASED RETRIEVAL Kenneth D. Forbus Dedre...Gentner Keith Law Technical Report #59 • October 1994 94-35188 wit Establisthed in 1989 with the support of Andersen Consulting Form Approved REPORT

[The Gongylonematid parasitic in the elephant shrew Elephantus rozeti (Macrocelidae) in Tunisia was identified as Gongylonema brevispiculum Seurat, 1914 (author's transl)].

PubMed

Quentin, J C; Seureau, C

1978-01-01

Its larval form obtained from experimentally infected intermediate hosts, differs from those of other Gongylonematids. In the genus Gongylonema four types of larvae were recognized. They are characterized by the size and the cephalic and caudal structures of the larvae. The cellular reactions caused by the larvae of G. brevispiculum in the insect muscles are similar to those caused by infections with larvae of Acuarid nematodes.

THE subfossil occurrence and paleoecological significance of small mammals at ankilitelo cave, southwestern Madagascar

USGS Publications Warehouse

Muldoon, K.M.; De Blieux, D. D.; Simons, E.L.; Chatrath, P.S.

2009-01-01

Small mammals are rarely reported from subfossil sites in Madagascar despite their importance for paleoenvironmental reconstruction, especially as it relates to recent ecological changes on the island. We describe the uniquely rich subfossil small mammal fauna from Ankilitelo Cave, southwestern Madagascar. The Ankilitelo fauna is dated to the late Holocene (???500 years ago), documenting the youngest appearances of the extinct giant lemur taxa Palaeopropithecus, Megaladapis, and Archaeolemur, in association with abundant remains of small vertebrates, including bats, tenrecs, carnivorans, rodents, and primates. The Ankilitelo fauna is composed of 34 mammalian species, making it one of the most diverse Holocene assemblages in Madagascar. The fauna comprises the 1 st report of the short-tailed shrew tenrec (Microgale brevicaudata) and the ring-tailed mongoose (Galidia elegans) in southwestern Madagascar. Further, Ankilitelo documents the presence of southwestern species that are rare or that have greatly restricted ranges today, such as Nasolo's shrew tenrec (M. nasoloi), Grandidier's mongoose (Galidictis grandidieri), the narrow-striped mongoose (Mungotictis decemlineata), and the giant jumping rat (Hypogeomys antimena). A simple cause for the unusual small mammal occurrences at Ankilitelo is not obvious. Synergistic interactions between climate change, recent fragmentation and human-initiated degradation of forested habitats, and community-level processes, such as predation, most likely explain the disjunct distributions of the small mammals documented at Ankilitelo. ?? 2009 American Society of Mammalogists.

At the foot of the shrew: Manus morphology distinguishes closely-related Cryptotis goodwini and Cryptotis griseoventris (Mammalia: Soricidae) in Central America

USGS Publications Warehouse

Woodman, Neal; Stephens, Ryan B.

2010-01-01

Small-eared shrews (Mammalia, Soricidae) of the New World genus Cryptotis are distributed from eastern North America to the northern Andes of South America. One well-defined clade in this genus is the Central American Cryptotis mexicana group, whose members are set off from other species in the genus by their variably broader fore feet and more elongate and broadened fore claws. Two species in the C. mexicana group, Cryptotis goodwini Jackson and Cryptotis griseoventris Jackson, inhabit highlands in Guatemala and southern Mexico and are presumed to be sister species whose primary distinguishing feature is the larger body size of C. goodwini. To better characterize these species and confirm the identification of recently-collected specimens, we obtained digital X-ray images of the manus from large series of dried skins of both species. Measurements of the metacarpals and phalanges successfully separated most specimens of C. goodwini and C. griseoventris. These measurements also show that the fore feet of C. griseoventris from Chiapas, Mexico, are morphologically distinct from those of members of the species inhabiting Guatemala. Univariate, bivariate, and multivariate analyses indicate that fore foot characters are more conservative within species of the C. mexicana group than are cranio-mandibular characters. Patterns of evolution of fore foot characters that superficially appear to be linear gradations are actually more complex, illustrating individual evolutionary trajectories.

Predator-induced synchrony in population oscillations of coexisting small mammal species.

PubMed

Korpimäki, Erkki; Norrdahl, Kai; Huitu, Otso; Klemola, Tero

2005-01-22

Comprehensive analyses of long-term (1977-2003) small-mammal abundance data from western Finland showed that populations of Microtus voles (field voles M. agrestis and sibling voles M. rossiaemeridionalis) voles, bank (Clethrionomys glareolus) and common shrews (Sorex araneus) fluctuated synchronously in 3 year population cycles. Time-series analyses indicated that interspecific synchrony is influenced strongly by density-dependent processes. Synchrony among Microtus and bank voles appeared additionally to be influenced by density-independent processes. To test whether interspecific synchronization through density-dependent processes is caused by predation, we experimentally reduced the densities of the main predators of small mammals in four large agricultural areas, and compared small mammal abundances in these to those in four control areas (2.5-3 km(2)) through a 3 year small-mammal population cycle. Predator reduction increased densities of the main prey species, Microtus voles, in all phases of the population cycle, while bank voles, the most important alternative prey of predators, responded positively only in the low and the increase phase. Manipulation also increased the autumn densities of water voles (Arvicola terrestris) in the increase phase of the cycle. No treatment effects were detected for common shrews or mice. Our results are in accordance with the alternative prey hypothesis, by which predators successively reduce the densities of both main and alternative prey species after the peak phase of small-mammal population cycles, thus inducing a synchronous low phase.

Distributions of vesicular glutamate transporters 1 and 2 in the visual system of tree shrews (Tupaia belangeri).

PubMed

Balaram, P; Isaamullah, M; Petry, H M; Bickford, M E; Kaas, J H

2015-08-15

Vesicular glutamate transporter (VGLUT) proteins regulate the storage and release of glutamate from synapses of excitatory neurons. Two isoforms, VGLUT1 and VGLUT2, are found in most glutamatergic projections across the mammalian visual system, and appear to differentially identify subsets of excitatory projections between visual structures. To expand current knowledge on the distribution of VGLUT isoforms in highly visual mammals, we examined the mRNA and protein expression patterns of VGLUT1 and VGLUT2 in the lateral geniculate nucleus (LGN), superior colliculus, pulvinar complex, and primary visual cortex (V1) in tree shrews (Tupaia belangeri), which are closely related to primates but classified as a separate order (Scandentia). We found that VGLUT1 was distributed in intrinsic and corticothalamic connections, whereas VGLUT2 was predominantly distributed in subcortical and thalamocortical connections. VGLUT1 and VGLUT2 were coexpressed in the LGN and in the pulvinar complex, as well as in restricted layers of V1, suggesting a greater heterogeneity in the range of efferent glutamatergic projections from these structures. These findings provide further evidence that VGLUT1 and VGLUT2 identify distinct populations of excitatory neurons in visual brain structures across mammals. Observed variations in individual projections may highlight the evolution of these connections through the mammalian lineage. © 2015 Wiley Periodicals, Inc.

Molecular Genetics of Supernumerary Tooth Formation

PubMed Central

Wang, Xiu-Ping; Fan, Jiabing

2011-01-01

Summary Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhibit one dentition, with very few mouse models exhibiting supernumerary teeth similar to those in humans. Inactivation of Apc or forced activation of Wnt/β(catenin signalling results in multiple supernumerary tooth formation in both humans and in mice, but the key genes in these pathways are not very clear. Analysis of other model systems with continuous tooth replacement or secondary tooth formation, such as fish, snake, lizard, and ferret, is providing insights into the molecular and cellular mechanisms underlying succesional tooth development, and will assist in the studies on supernumerary tooth formation in humans. This information, together with the advances in stem cell biology and tissue engineering, will pave ways for the tooth regeneration and tooth bioengineering. PMID:21309064

Development and growth of compound tooth plates in Callorhinchus milii (chondrichthyes, holocephali).

PubMed

Didier, D A; Stahl, B J; Zangerl, R

1994-10-01

The chimaeroid holocephalian fishes are distinguished among extant chondrichthyans by the possession of three pairs of tooth plates, evergrowing and partially hypermineralized, that are not shed and replaced like the teeth of living elasmobranchs. Although derivation of the chimaeroid tooth plate from the fusion of members of a plesiomorphic chondrichthyan tooth family has been proposed, evidence for this hypothesis has been lacking. A new analysis of the development and structure of the tooth plates in Callorhinchus milii (Holocephali, Chimaeriformes) reveals the compound nature of the tooth plates in a chimaeroid fish. Each tooth plate consists of an oral and aboral territory that form independently in the embryo and maintain separate growth surfaces through life. The descending lamina on the aboral surface of the tooth plate demarcates the growth surface of the aboral territory. Comparison with the tooth plates of Chimaera monstrosa indicates that compound tooth plates may be a feature of all chimaeroids in which a descending lamina is present. The tooth plates in these fishes represent the fusion of two members of a reduced tooth family. The condition of the tooth plates in C. milii is plesiomorphic for chimaeroids and is of evolutionary significance in that it provides further evidence to support a lyodont dentition in chimaeroid fishes similar to that found in other chondrichthyans. © 1994 Wiley-Liss, Inc. Copyright © 1994 Wiley-Liss, Inc.

Elemental mapping of teeth using μSRXRF

NASA Astrophysics Data System (ADS)

Anjos, M. J.; Barroso, R. C.; Pérez, C. A.; Braz, D.; Moreira, S.; Dias, K. R. H. C.; Lopes, R. T.

2004-01-01

Human teeth were analysed by X-ray microfluorescence analysis using synchrotron radiation (μSRXRF). The aim of this work was to study the elemental distribution for Ca, Zn and Sr along the dental regions, enamel, dentine and pulp from patterns of relative fluorescence intensities. The measurements were performed in standard geometry of 45° incidence, exciting with a white beam and using a conventional system collimation (orthogonal slits) in the XRF beamline at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that Ca distribution is quite constant and it is independent of the tooth type and individuals characteristics. An increase of the Zn concentration was found for the pulp region and for untreated carious areas. Ca and Sr distributions show a similar behavior.

A new record of pasiphaeid shrimp of the genus Pasiphaea (Crustacea: Decapoda: Caridea) in Korean waters

NASA Astrophysics Data System (ADS)

Kim, Jung Nyun; Choi, Jung Hwa; Jo, Hyun-su

2016-09-01

A single specimen of the pelagic shrimps, Pasiphaea japonica Omori, 1976 (Pasiphaeidae) collected in the southeastern waters of Korea is described and illustrated. Although this species occurs widely in the Indo-West Pacific including the Japanese coast of the East/Japan Sea and the middle and southern parts of the East China Sea, this is the first record of the species and the genus in Korean waters. The species is distinguished from other congeners by the following combination of characteristics: non-carinate dorsal sixth abdominal somite with a terminal tooth, rudimentary pleurobranch on the eighth thoracic somite, merus of the first pereopod with more than eight spines, and almost entirely transparent white color.

Study of the kinematic and load sharing properties of wormgearing with non-symmetric tooth profiles

NASA Technical Reports Server (NTRS)

Sun, D. C.; Yuan, Qin

1995-01-01

The geometry of non-symmetric tooth profiles, i.e. tooth profiles with different pressure angles on the two sides of the tooth, is studied. A feasible non-symmetric tooth profile for application in helicopter transmissions is laid out as the best compromise among several conflicting factors. The non-symmetric tooth profile is then compared with the symmetric tooth profile studied previously. Based on the detailed comparisons it is concluded that the use of the non-symmetric tooth profile would severely limit the face width of the worm, consequently reduce the number of meshing teeth and cause much higher normal load on the individual gear teeth.

Discoloration Potential of Endodontic Sealers: A Brief Review

PubMed Central

Tour Savadkouhi, Sohrab; Fazlyab, Mahta

2016-01-01

Tooth discoloration induced by endodontic sealers, is a common finding that impairs aesthetic outcome of endodontic treatment. The aim of the present mini literature review, was to summarize the existing data on discoloration potential of different endodontic sealers. The research covered the article published in PubMed and Google Scholar from 2000 to 2015. The searched keywords included ‘tooth discoloration AND endodontic’, ‘tooth discoloration AND sealer, ‘tooth discoloration AND zinc-oxide eugenol sealer’, ‘tooth discoloration AND Calcium Hydroxide Sealer’, ‘tooth discoloration AND Glass Ionomer Sealer’, ‘tooth discoloration AND epoxy-resin Sealer’, ‘tooth discoloration AND Silicon Based Sealer’, ‘tooth discoloration AND Bioceramic Sealer’ and ‘Spectrophotometry’. Conclusion: A total number of 44 articles were gained which reduced to 11 after excluding the repetitive items. The available evidence for discoloration potential of endodontic sealers currently available on the market is scarce. However, it can be concluded that all endodontic sealers can potentially stain the tooth structure to different degrees. PMID:27790251

Tooth colour change with Ozicure Oxygen Activator: a comparative in vitro tooth bleaching study.

PubMed

Grundlingh, A A; Grossman, E S; Witcomb, M J

2012-08-01

This in vitro study compared a new tooth bleaching product, Ozicure Oxygen Activator (O3, RSA) with Opalescence Quick (Ultradent, USA) using a randomised block design to assess tooth colour change. Colour change, stability and relapse in canine, incisor and premolar teeth was assessed following three bleach treatments and subsequent tooth colour assessment. Ninety nine teeth (canines, incisors and premolars), which were caries free, had no surface defects and were within the colour range 1M2 and 5M3 were selected. Teeth were randomly divided into the three experimental groups: Opalescence Quick, Ozicure Oxygen Activator and control. The three experimental groups received three treatments of one hour each over three consecutive days. Tooth colour was assessed using the Vitapan 3D Master Tooth Guide (VITA, Germany). A General Linear Models test for analysis of variance for a fractional design with significance set at P < 0.05 was used to test for significance. Both bleaching methods significantly lightened the teeth (P < 0.0001). Tooth colour change was mainly after the first hour of tooth bleaching. The tooth type was significant in tooth colour change (P = 0.0416). Tooth colour relapse and resistance to colour change were observed. Ozicure Oxygen Activator bleached teeth in a manner and to an extent similar to Opalescence Quick.

Inhibitory effect of interferon-γ on experimental tooth movement in mice.

PubMed

Kohara, Haruka; Kitaura, Hideki; Yoshimatsu, Masako; Fujimura, Yuji; Morita, Yukiko; Eguchi, Toshiko; Yoshida, Noriaki

2012-09-01

The aim of this study was to investigate the effects of interferon (IFN)-γ on experimental tooth movement in mice using a murine experimental tooth movement model. An Ni-Ti closed-coil spring was inserted between the upper-anterior alveolar bones and the upper-left first molars in mice. We evaluated the relationship between local Ifn-γ mRNA levels and orthodontic tooth movement. In other experiments, IFN-γ was injected adjacent to each first molar every other day during tooth movement. After 12 days, the amount of tooth movement was measured. Tartrate-resistant acid phosphatase (TRAP)-positive cells at the pressure side of each experimental tooth were counted as osteoclasts. Local Ifn-γ mRNA expression increased with orthodontic tooth movement. The number of TRAP-positive cells increased on the pressure side of the first molar. In contrast, the degree of tooth movement and the number of TRAP-positive cells on the pressure side in IFN-γ-injected mice were less than those of control mice. IFN-γ was induced in experimental tooth movement, and could inhibit mechanical force-loaded osteoclastogenesis and tooth movement. These results suggest that IFN-γ might be useful in controlling orthodontic tooth movement because of its inhibitory action on excessive osteoclastogenesis during this movement.

Occlusal tooth wear in the general population of Germany: effects of age, sex, and location of teeth.

PubMed

Schierz, Oliver; Dommel, Sandra; Hirsch, Christian; Reissmann, Daniel R

2014-09-01

Tooth wear is an increasing problem in a society where people are living longer. The purpose of this study was to assess the effect of age, sex, and location of teeth on the severity of tooth wear and to determine the prevalence of dentin exposure in the general population of Germany. Tooth wear was measured in casts of both jaws of 836 persons with a 6-point (0-5) ordinal rating scale. Linear random-intercept regression models with the covariates of age, sex, jaw, and tooth group (with the participant as a grouping variable) were computed to determine the association of these covariates with tooth wear of a single tooth. The mean tooth wear score across all age groups, both sexes, and all teeth was 2.9 (standard deviation, 0.8), and the prevalence of teeth with exposed dentin was 23.4%. The participants' age was correlated with the mean tooth wear scores (r=0.51). The tooth wear level among women was on average 0.15 units lower than among men, and tooth wear was on average 0.59 units higher for anterior teeth than for posterior teeth. Increased tooth wear in anterior teeth may be due to the initially predominant guidance by anterior teeth, with age-related linear progress in tooth wear. Occlusal tooth wear scores and dentin exposure increase with age. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Tooth bleaching and young adults in Nigeria: knowledge, experiences and intention.

PubMed

Azodo, C C; Ogbomo, A C; Agbor, M A

2012-12-01

To assess the knowledge, experiences and intention to have tooth bleaching among young adults studying in a Nigerian University. A cross-section of part-time undergraduate students of University of Benin, Benin City, Nigeria were studied in 2010 using a self-administered questionnaire. About three-quarters 289 (72.4%) of the respondents reported awareness of at least one cause of tooth discoloration. A total of 143 (35.8%) of the respondents have heard of tooth bleaching with main sources of information being friends/relatives, dentists and the internet. One-third 132 (33.1%) of the respondents correctly identified that the aim of tooth bleaching was to make the teeth whiter. The respondents that had correct knowledge about mechanism, duration and complications of tooth bleaching were 51 (12.8%), 25 (6.3%) and 35 (8.8%) respectively. The major perceived benefits of tooth bleaching reported by the respondents were self confidence boost 152 (38.1%) and improvement of one's beauty 107 (26.8%). Out of the 68 (17.0%) respondents that have attempted tooth bleaching, 36 (52.9%) used tooth whitening toothpaste. Out of the 151 (37.8%) respondents that expressed intention of having tooth bleaching procedure, 32 (21.2%) would pursue the course, no matter the cost. In the studied population, knowledge of tooth discoloration was high, awareness and experiences of tooth bleaching were low but significant number expressed intention of having tooth bleaching. It is important that dentists increase oral health information particularly tooth bleaching information accessibility to the young adult population to improve the knowledge and prevent adverse effects.

Tooth quality in dental fluorosis genetic and environmental factors.

PubMed

Vieira, A P G F; Hanocock, R; Eggertsson, H; Everett, E T; Grynpas, M D

2005-01-01

Dental fluorosis (DF) affects the appearance and structure of tooth enamel and can occur following ingestion of excess fluoride during critical periods of amelogenesis. This tooth malformation may, depending on its severity, influence enamel and dentin microhardness and dentin mineralization. Poor correlation between tooth fluoride (F) concentration and DF severity was shown in some studies, but even when a correlation was present, tooth fluoride concentration explained very little of DF severity. This fact calls into question the generally accepted hypothesis that the main factor responsible for DF severity is tooth fluoride concentration. It has been shown previously that genetic factors (susceptibility to DF) play an important role in DF severity although DF severity relates to individual susceptibility to fluoride exposure (genetics), tooth fluoride concentration relates to fluoride ingestion (environmental). The objective of this study was to investigate the correlation between tooth fluoride concentration, DF severity, and tooth mechanical and materials properties. Three strains of mice (previously shown to have different susceptibility to DF) at weaning were treated with four different levels of F in their water (0, 25, 50, and 100 ppm) for 6 weeks. Mice teeth were tested for fluoride by instrumental neutron activation analysis (INAA), DF severity determined by quantitative light-induced fluorescence [QLF], and tooth quality (enamel and dentin microhardness and dentin mineralization). Tooth fluoride concentration (environment factor) correlated positively with DF severity (QLF) (rs=0.608), fluoride treatment group (rs=0.952). However, tooth fluoride concentration correlated negatively with enamel microhardness (rs=-0.587), dentin microhardness (rs=-0.268) and dentin mineralization (rs=-0.245). Dental fluorosis (genetic factor) severity (QLF) correlated positively with fluoride treatment (rs=0.608) and tooth fluoride concentration (rs=0.583). DF severity correlated negatively with enamel microhardness (rs=-0.564) and dentin microhardness (rs=-0.356). Genetic factors (DF severity) and the environmental factor (fluoride concentration in tooth structure) have similar influence on tooth biomechanical properties, whereas only the environmental factor has an influence on tooth material property (mineralization).

Tooth - abnormal shape

MedlinePlus

Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... The appearance of normal teeth varies, especially the molars. ... conditions. Specific diseases can affect tooth shape, tooth ...

Prevalence of Tooth Shade and its Correlation with Skin Colour - A Cross-sectional Study.

PubMed

Vadavadagi, Suneel V; Kumari, K V Halini; Choudhury, Gopal Krishna; Vilekar, Abhishek Madhukar; Das, Sitansu Sekhar; Jena, Debkant; Kataraki, Bharat; B L, Bhavana

2016-02-01

Aesthetics has become an important issue in modern society. Tooth shade is one of the factors in determining aesthetics. Studies have revealed that tooth shade is influenced by age, gender, eye colour, skin colour and other factors. The present study was aimed to assess the prevalence of tooth shade and its correlation with skin colour. A total of 300 subjects aged 18-20 years were evaluated for tooth shade using Vitapan - 3D shade guide. Anterior teeth were checked under natural light and facial skin colour by Lakme liquid foundation make up as a shade guide. Data was analysed using chi square test and spearman's correlation. Out of 300 students, 114 (38.00%) had A2 tooth shade; the least prevalent tooth shade among Chitradurga population was C1 (4.00%). There was a positive correlation between tooth shade and skin colour which was found to be statistically significant (p <0.05). The most prevalent tooth shade among Chitradurga population was A2 and least was C1. There was a significant correlation between tooth shade and skin colour with lighter skin tone subjects having lighter tooth shade hence skin colour can be used as a guide for shade selection.

Application of tooth brushing behavior to active rest.

PubMed

Sadachi, Hidetoshi; Murakami, Yoshinori; Tonomura, Manabu; Yada, Yukihiro; Simoyama, Ichiro

2010-01-01

We evaluated the usefulness of tooth brushing with toothpaste as active rest using the flicker value as a physiological parameter and a subjective questionnaire as a psychological parameter. Seventeen healthy, right-handed subjects (12 males and 5 females) aged 22.5 +/- 1.5 yr (mean +/- standard deviation) were randomly divided into tooth brushing with toothpaste (N=9) and non-tooth brushing groups (N=8). The subjects performed a serial calculation task for 20 min using personal computers. Subsequently, the tooth brushing group brushed their teeth, and the flicker value and mood were compared before and after the tooth brushing. The flicker value significantly increased in the tooth brushing group compared with the non-tooth brushing group (p<0.05). Concerning the mood, in the tooth brushing group, the incidence of a "feeling of being refreshed" significantly increased (p<0.05), that of "concentration power" or a "feeling of clear-headedness" tended to increase (p<0.1), and that of "lassitude" or "sleepiness" significantly decreased (p<0.01). Somatosensory stimulation and intraoral tactile stimulation during tooth brushing activated cerebral activity, producing refreshing effects. These results suggest the applicability of tooth brushing to active rest.

[Assessment of tooth bleaching efficacy with spectrophotometer].

PubMed

Zhu, Wenhao; Liu, Chang; Pan, Jie

2014-06-01

To analyze the changes in CIE L*, a*, and b* at cervical, body, and incisal sites after tooth bleaching by using a spectrophotometer. Sixty-seven intact and healthy maxillary central incisors were in-vestigated. These incisors were darker than A3 according to the Vita Classical shade guide. The CIE tooth shade parameters L*, a*, and b* were simultaneously recorded at three tooth areas (cervical, body, and incisal) with a spectrophotometer before and after tooth bleaching (35%H2O2 coordinating with Beyond whitening accelerator irradiating). The shade dif-ferential (DeltaE) was calculated. ANOVA, paired t-test, and Pearson correlation analysis were used for data analysis. The efficacy rates of tooth bleaching were satisfactory, with 86.6%, 86.6%, and 85.1% in the cervical, body, and incisal sites, respectively. The average values of DeltaE were 5.09, 4.44, and 4.40 in the cervical, body, and incisal sites. Tooth bleaching significantly increased L* and significantly decreased a* and b* in all tooth areas (P < 0.01). The decreasing range of Deltab* was more than the increasing range of DeltaL* at the cervical site; opposite results were observed at the incisal site. A positive correlation was detected between baseline b* and DeltaE. The spectrophotometer could objectively evaluate the whitening effect of tooth bleaching at the different tooth sites. The tooth bleaching system (35%H202 coordinating with Beyond whitening accelerator irradiating) exerts powerful bleaching actions in most of the tooth areas investigated. The order of tooth bleaching effectiveness is cervicalbody>incisal. Yellow coloration is decreased mainly at the cervical site, and brightness was increased mostly at theincisal site. The effectiveness of tooth bleaching increases as the baseline b* value increases.

Distinct developmental genetic mechanisms underlie convergently evolved tooth gain in sticklebacks

PubMed Central

Ellis, Nicholas A.; Glazer, Andrew M.; Donde, Nikunj N.; Cleves, Phillip A.; Agoglia, Rachel M.; Miller, Craig T.

2015-01-01

Teeth are a classic model system of organogenesis, as repeated and reciprocal epithelial and mesenchymal interactions pattern placode formation and outgrowth. Less is known about the developmental and genetic bases of tooth formation and replacement in polyphyodonts, which are vertebrates with continual tooth replacement. Here, we leverage natural variation in the threespine stickleback fish Gasterosteus aculeatus to investigate the genetic basis of tooth development and replacement. We find that two derived freshwater stickleback populations have both convergently evolved more ventral pharyngeal teeth through heritable genetic changes. In both populations, evolved tooth gain manifests late in development. Using pulse-chase vital dye labeling to mark newly forming teeth in adult fish, we find that both high-toothed freshwater populations have accelerated tooth replacement rates relative to low-toothed ancestral marine fish. Despite the similar evolved phenotype of more teeth and an accelerated adult replacement rate, the timing of tooth number divergence and the spatial patterns of newly formed adult teeth are different in the two populations, suggesting distinct developmental mechanisms. Using genome-wide linkage mapping in marine-freshwater F2 genetic crosses, we find that the genetic basis of evolved tooth gain in the two freshwater populations is largely distinct. Together, our results support a model whereby increased tooth number and an accelerated tooth replacement rate have evolved convergently in two independently derived freshwater stickleback populations using largely distinct developmental and genetic mechanisms. PMID:26062935

Factors associated with tooth loss and prosthodontic status among Sudanese adults.

PubMed

Khalifa, Nadia; Allen, Patrick F; Abu-bakr, Neamat H; Abdel-Rahman, Manar E

2012-01-01

A study was conducted to determine the degree of tooth loss, factors influencing tooth loss, and the extent of prosthodontic rehabilitation in Sudanese adults (≥ 16 years old) attending outpatient clinics in Khartoum State. Pearson and multivariate analyses were used to examine the relationships between tooth loss and specific characteristics determined through interviews and clinical examinations. The mean number of missing teeth was 3.6 (SD, 4.9) and the prevalence of edentulism was 0.1%. The prevalence of tooth loss (missing at least one tooth) was 78%; 66.9% of tooth loss was due to caries, and 11.2% was attributable to other reasons. Prosthetic replacement of missing teeth was evident in 3%, whereas a need for prosthetic replacement was evident in 57%. Having < 20 teeth was associated with age, gender, and socioeconomic status; tooth loss due to caries was associated with age, tribe, frequency of tooth-brushing, and a low rate of dental consultation. Tooth loss due to other reasons was associated with age, tribe, education, periodontal pocketing, tobacco use, tooth wear, and prosthetic status. The results of the present study indicated that the major cause of tooth loss was dental caries, thus emphasizing the importance of a public prevention-based healthcare program. Replacement of missing teeth was uncommon in the study subjects, which may reflect lack of access to this type of oral healthcare.

Influence of tooth profile on the noncircular gear tooth contact

NASA Astrophysics Data System (ADS)

Cristescu, A.; Andrei, L.; Cristescu, B.

2017-02-01

With noncircular gears, the continuous modification of the tooth meshing, in terms of variation of the tooth profiles and the line of action position and inclination, makes difficult the implementation of a general standard procedure for the analysis of the noncircular gears tooth contact. In this paper, the authors present a graphical approach that enables the tooth contact static pattern to be produced and evaluated in case of a noncircular gear with complex geometry of the pitch curve. The study is virtually developed, in AutoCAD environment, by animating and investigating the gear solid models in mesh. The tooth static contact analysis enables the path of contact area and distribution to be evaluated in correlation with the following variable initial data: gear pitch curve geometry, tooth profile geometry, as a consequence of different generating procedures, and the gear pressure angle. It was found out that the noncircular gear tooth contact could be improved by choosing different procedures for the tooth flank generation in concave and convex zones and by increasing the gear pressure angle.

The prevalence, aetiology and clinical appearance of tooth wear: the Nigerian experience.

PubMed

Oginni, O; Olusile, A O

2002-08-01

To establish the prevalence and severity of tooth wear among Nigerians and to compare the pattern and aetiology with findings of earlier studies in Western populations. Clinical examinations for tooth wear using the tooth wear index (TWI). The Federal Republic of Nigeria. Patients attending the Dental Hospital, Obafemi Awolowo University Teaching Hospital's Complex Ile-Ife. Attrition, abrasion and erosion. Of the 126 patients with tooth wear 81 had attrition, 20 had abrasion, 9 had erosion and 16 had attrition and abrasion combined. A total of 15,480 tooth surfaces were examined. 2,229 (14.4%) surfaces had tooth wear out of which 1,007 (6.5%) were pathologically worn down. The frequency of tooth wear increased with the age of patients. Most of the pathologically worn surfaces were just one point above maximum acceptable value. The aetiological factors associated with tooth wear are not different from those encountered in Western cultures but the pattern of wear differs. Pathological tooth wear presents as an age related phenomenon and is probably more severe in Nigerians.

Additional Cultural Resources Investigations at Selected Portions of the State-Road Coulee - Pammel Creek Flood Control Project at La Crosse, Wisconsin

DTIC Science & Technology

1986-05-01

Mammals: Ten mammal taxa are represented in the Lc176 assemblage. Two of these, the short-tailed shrew (Blarina brevivicauda) and a vole (Microtus sp...ADDITIONAL CULTURAL RESOURCES INVESTIGATIONS AT SELECTED PORTIONS OF THE STATE-ROAD COULEE - PAMMEL CREEK FLOOD CONTROL PROJECT ATm LA CROSSE...INVESTIGATIONS AT SELECTED PORTIONS OF THE STATE-ROAD COULEE- PAMMEL CREEK FLOOD CONTROL PROJECT AT LA CROSSE. WISCONSIN 12. PERSONAL AUTHOR(S

First report of a parasitic mite, Leptotrombidium (Hypotrombidium) subquadratum (Lawerence) (Acari: Trombiculidae: Trombiculinae), from dogs and children in the Bloemfontein area, South Africa.

PubMed

Heyne, H; Ueckermann, E A; Coetzee, L

2001-06-01

Leptotrombidium subqunadratum larvae were collected for the first time in 1994 from dogs in Bloemfontein. The larvae have been collected annually, during the summer months, over a period of 6-7 years. Previously the only known hosts were scrub hare (Lepus saxatilis) (locality unknown) and short-snouted elephant shrew (Elephantulus brachyrhynchus) (Kruger National Park). These mites cause severe itching and dermatitis in humans and dogs.

Woodbridge Research Facility Remedial Investigation/Feasibility Study; Remedial Investigation, Volume 1 - Text, Tables, and Figures

DTIC Science & Technology

1997-11-01

toxic form of organic mercury ( Eisler , 1987 ). The EEQs were calculated for both inorganic mercury and methyl mercury for robins and shrews to...always less than the toxicity of methylmercury, and methylmercury is the most toxic form of organic mercury ( Eisler , 1987 ), this assumption is likely to...The UST was installed in 1966 and was used to store #2 fuel oil. The tank was removed in 1986 or 1987 with no record of leak testing or soil

Ameloglyphics: A possible forensic tool for person identification following high temperature and acid exposure

PubMed Central

Juneja, Manjushree; Juneja, Saurabh; Rakesh, Nagaraju; Bhoomareddy Kantharaj, Yashoda Devi

2016-01-01

Introduction: Forensic odontology is a branch that is evolving over time and has opened newer avenues that may help in the identification of individuals. Tooth prints are the enamel rod end patterns on tooth surface and they are considered as a hard tissue analog to fingerprints. Teeth have the highest resistance to most environmental effects like fire, desiccation, and decomposition, and may be used as a forensic evidence. Aims and Objectives: The aim of the study was to evaluate if the tooth prints could be used for an individual's identification and reproducibility and permanency of these tooth prints after exposing the teeth to acid and various degrees of temperature. Materials and Methods: 90 tooth prints from 20 freshly extracted maxillary premolar teeth were obtained. Cellophane tape technique was used to record enamel rod end patterns on tooth surface. Ten teeth (one from each patient) were immersed in 36.46% hydrochloric acid and the tooth prints were obtained at various intervals (5 min, 10 min, and 20 min). The other 10 teeth (one from each patient) were incinerated and impression was made at various intervals (80° C, 400° C, 600° C, and 750° C). Tooth prints obtained from different teeth (total of 90 tooth prints) were analyzed using Verifinger® standard SDK version 5.0 software. Results: All the 20 original tooth prints were distinct from each other and no inter-individual or intra-individual similarity was found. The tooth prints from the same tooth after it was exposed to acid or heat were reproducible and showed high to very high similarity with the original tooth print of that particular tooth stored in the database. Conclusion: Tooth prints may be used as an effective aid in person identification even in adverse conditions such as burn and acid attack injuries. PMID:27051220

Associations between smoking and tooth loss according to reason for tooth loss

PubMed Central

Mai, Xiaodan; Wactawski-Wende, Jean; Hovey, Kathleen M.; LaMonte, Michael J.; Chen, Chaoru; Tezal, Mine; Genco, Robert J.

2013-01-01

Background Smoking is associated with tooth loss. However, smoking's relationship to the specific reason for tooth loss in postmenopausal women is unknown. Methods Postmenopausal women (n = 1,106) who joined a Women's Health Initiative ancillary study (The Buffalo OsteoPerio Study) underwent oral examinations for assessment of the number of missing teeth, as well as the self-reported reasons for tooth loss. The authors obtained information about smoking status via a self-administered questionnaire. The authors calculated odds ratios (ORs) and 95 percent confidence intervals (CIs) by means of logistic regression to assess smoking's association with overall tooth loss, as well as with tooth loss due to periodontal disease (PD) and with tooth loss due to caries. Results After adjusting for age, education, income, body mass index (BMI), history of diabetes diagnosis, calcium supplement use and dental visit frequency, the authors found that heavy smokers (≥ 26 pack-years) were significantly more likely to report having experienced tooth loss compared with never smokers (OR = 1.82; 95 percent CI, 1.10-3.00). Smoking status, packs smoked per day, years of smoking, pack-years and years since quitting smoking were significantly associated with tooth loss due to PD. For pack-years, the association for heavy smokers compared with that for never smokers was OR = 6.83 (95 percent CI, 3.40-13.72). The study results showed no significant associations between smoking and tooth loss due to caries. Conclusions and Practical Implications Smoking may be a major factor in tooth loss due to PD. However, smoking appears to be a less important factor in tooth loss due to caries. Further study is needed to explore the etiologies by which smoking is associated with different types of tooth loss. Dentists should counsel their patients about the impact of smoking on oral health, including the risk of tooth loss due to PD. PMID:23449901

Tooth fracture risk analysis based on a new finite element dental structure models using micro-CT data.

PubMed

Chen, G; Fan, W; Mishra, S; El-Atem, A; Schuetz, M A; Xiao, Y

2012-10-01

The finite element (FE) analysis is an effective method to study the strength and predict the fracture risk of endodontically-treated teeth. This paper presents a rapid method developed to generate a comprehensive tooth FE model using data retrieved from micro-computed tomography (μCT). With this method, the inhomogeneity of material properties of teeth was included into the model without dividing the tooth model into different regions. The material properties of the tooth were assumed to be related to the mineral density. The fracture risk at different tooth portions was assessed for root canal treatments. The micro-CT images of a tooth were processed by a Matlab software programme and the CT numbers were retrieved. The tooth contours were obtained with thresholding segmentation using Amira. The inner and outer surfaces of the tooth were imported into Solidworks and a three-dimensional (3D) tooth model was constructed. An assembly of the tooth model with the periodontal ligament (PDL) layer and surrounding bone was imported into ABAQUS. The material properties of the tooth were calculated from the retrieved CT numbers via ABAQUS user's subroutines. Three root canal geometries (original and two enlargements) were investigated. The proposed method in this study can generate detailed 3D finite element models of a tooth with different root canal enlargements and filling materials, and would be very useful for the assessment of the fracture risk at different tooth portions after root canal treatments. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Inhibition of Wnt signaling by Wise (Sostdc1) and negative feedback from Shh controls tooth number and patterning.

PubMed

Ahn, Youngwook; Sanderson, Brian W; Klein, Ophir D; Krumlauf, Robb

2010-10-01

Mice carrying mutations in Wise (Sostdc1) display defects in many aspects of tooth development, including tooth number, size and cusp pattern. To understand the basis of these defects, we have investigated the pathways modulated by Wise in tooth development. We present evidence that, in tooth development, Wise suppresses survival of the diastema or incisor vestigial buds by serving as an inhibitor of Lrp5- and Lrp6-dependent Wnt signaling. Reducing the dosage of the Wnt co-receptor genes Lrp5 and Lrp6 rescues the Wise-null tooth phenotypes. Inactivation of Wise leads to elevated Wnt signaling and, as a consequence, vestigial tooth buds in the normally toothless diastema region display increased proliferation and continuous development to form supernumerary teeth. Conversely, gain-of-function studies show that ectopic Wise reduces Wnt signaling and tooth number. Our analyses demonstrate that the Fgf and Shh pathways are major downstream targets of Wise-regulated Wnt signaling. Furthermore, our experiments revealed that Shh acts as a negative-feedback regulator of Wnt signaling and thus determines the fate of the vestigial buds and later tooth patterning. These data provide insight into the mechanisms that control Wnt signaling in tooth development and into how crosstalk among signaling pathways controls tooth number and morphogenesis.

Evaluation of the influence of implant placement timing on the esthetic outcomes of single tooth implant treatment in the anterior maxilla: A retrospective study.

PubMed

Arora, Himanshu; Ivanovski, Saso

2018-05-15

The purpose of this retrospective study was to investigate the influence of implant placement timing on the esthetic outcomes for single implants in the anterior maxilla. One hundred and ten patients (48 males; 62 females) who received a single-tooth implant after extraction either immediately (Type 1); after 4-8 weeks (Type 2); after 8-16 weeks (Type 3); or more than 16 weeks (Type 4) were evaluated in terms of esthetic outcomes after a mean post-placement interval of 26.3 months (range 12-116). Esthetic outcomes were measured using the Pink and White Esthetic Score (PES; WES). Stepwise regression analysis was performed to analyze the effect of timing of placement, as well as patient demographics and other clinical parameters on the esthetic outcomes. No statistically significantly differences in PES were found between the various treatment modalities with Type 1 implants (n = 33) scoring 10.58 ± 1.65 (median: 11), followed by 10.36 ± 2.09 (median: 10.5), 9.68 ± 2.43 (median: 10), and 9.63 ± 2.21 (median: 10) for Type 2 (n = 14), Type 3 (n = 19), and Type 4 (n = 44), respectively. For immediate implants, a trend towards better esthetic outcomes was observed when implant placement was done flaplessly in cases with intact buccal bone (Type 1A, median PES 11) as compared to cases with partial/complete missing buccal plates where a flap was raised (Type 1B, median PES 10). Overall, the only parameter that influenced esthetic outcomes (as measured by PES) was gender, with females having significantly superior results. The median WES was 8 and 96% of the crowns were deemed esthetically acceptable, with crowns placed by specialist prosthodontists yielding higher scores than those placed by general practitioners. Single tooth implants in the anterior maxilla showed satisfactory outcomes when measured with objective esthetic criteria. Timing of implant placement did not significantly influence the esthetic outcomes, although a trend towards better outcomes was seen with immediate implant placement as observed by higher median PES values. Single tooth implant placement in the anterior maxilla is a predictable treatment modality for achieving acceptable esthetic outcomes regardless of the timing of placement. © 2018 Wiley Periodicals, Inc.

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur.

PubMed

Liu, Min; Reed, David A; Cecchini, Giancarlo M; Lu, Xuanyu; Ganjawalla, Karan; Gonzales, Carol S; Monahan, Richard; Luan, Xianghong; Diekwisch, Thomas G H

2016-01-01

Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here, we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids vs. snakes: (i) the orientation of replacement teeth compared to the major tooth axis, (ii) the occurrence of resorption pits, and (iii) the mode of tooth implantation/attachment to the tooth bearing element (TBE). The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as Heloderma. In conjunction with the presence of resorption pits and the evidence for pseudothecodont tooth implantation, the tooth eruption and implantation characters described in the present study either place mosasaurs among the varanoids or suggest convergent evolution mechanisms between both clades, with mosasaurs evolving somewhat independently from a common varanoid ancestor.

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur

PubMed Central

Liu, Min; Reed, David A.; Cecchini, Giancarlo M.; Lu, Xuanyu; Ganjawalla, Karan; Gonzales, Carol S.; Monahan, Richard; Luan, Xianghong

2016-01-01

Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here, we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids vs. snakes: (i) the orientation of replacement teeth compared to the major tooth axis, (ii) the occurrence of resorption pits, and (iii) the mode of tooth implantation/attachment to the tooth bearing element (TBE). The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as Heloderma. In conjunction with the presence of resorption pits and the evidence for pseudothecodont tooth implantation, the tooth eruption and implantation characters described in the present study either place mosasaurs among the varanoids or suggest convergent evolution mechanisms between both clades, with mosasaurs evolving somewhat independently from a common varanoid ancestor. PMID:27242535

Kinematics modeling and experimentation of the multi-manipulator tooth-arrangement robot for full denture manufacturing.

PubMed

Zhang, Yong-de; Jiang, Jin-gang; Liang, Ting; Hu, Wei-ping

2011-12-01

Artificial teeth are very complicated in shape, and not easy to be grasped and manipulated accurately by a single robot. The method of tooth-arrangement by multi-manipulator for complete denture manufacturing proposed in this paper. A novel complete denture manufacturing mechanism is designed based on multi-manipulator and dental arch generator. Kinematics model of the multi-manipulator tooth-arrangement robot is built by analytical method based on tooth-arrangement principle for full denture. Preliminary experiments on tooth-arrangement are performed using the multi-manipulator tooth-arrangement robot prototype system. The multi-manipulator tooth-arrangement robot prototype system can automatically design and manufacture a set of complete denture that is suitable for a patient according to the jaw arch parameters. The experimental results verified the validity of kinematics model of the multi-manipulator tooth-arrangement robot and the feasibility of the manufacture strategy of complete denture fulfilled by multi-manipulator tooth-arrangement robot.

Orthodontic Tooth Movement: A Historic Prospective.

PubMed

Will, Leslie A

2016-01-01

The earliest report on orthodontic tooth movement in the English literature was published in 1911. Oppenheim carried out studies on baboons to determine what histologic changes occurred during tooth movement. Reitan and many others carried out research into the nature of tooth movement. The pressure-tension model of tooth movement developed from these studies, whereby the two sides of the tooth responded to forces as if in isolation. A second theory, proposed by Stuteville in 1938, was the hydraulic theory of tooth movement. In this theory, fluid from the vasculature, lymphatic system and intercellular spaces responds to the forces of tooth movement, damping the force and limiting movement. Bien and Baumrind expanded on this theory with their own studies in the 1960s. It is clear that both the pressure-tension and fluid flow concepts have merit, but considerable work needs to be done to ascertain the details so that tooth movement can be managed and controlled. © 2016 S. Karger AG, Basel.

Tooth Eruption without Roots

PubMed Central

2013-01-01

Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the difficulties in studying late stages of tooth development and tooth movement and the lack of good model systems. Transgenic mice with eruption problems and short or no roots can be used as a powerful model for further deciphering of the cellular, molecular, and genetic mechanisms underlying root formation and tooth eruption. Better understanding of these processes can provide hints on delivering more efficient dental therapies in the future. PMID:23345536

Monte Carlo simulation for light propagation in 3D tooth model

NASA Astrophysics Data System (ADS)

Fu, Yongji; Jacques, Steven L.

2011-03-01

Monte Carlo (MC) simulation was implemented in a three dimensional tooth model to simulate the light propagation in the tooth for antibiotic photodynamic therapy and other laser therapy. The goal of this research is to estimate the light energy deposition in the target region of tooth with given light source information, tooth optical properties and tooth structure. Two use cases were presented to demonstrate the practical application of this model. One case was comparing the isotropic point source and narrow beam dosage distribution and the other case was comparing different incident points for the same light source. This model will help the doctor for PDT design in the tooth.

Sinus floor elevation from a maxillary molar tooth extraction socket in a patient with chronic inflammation.

PubMed

Tözüm, Tolga F; Dursun, Erhan; Tulunoglu, Ibrahim

2009-03-01

The compromised nature of the residual interradicular bone after extraction of periodontally hopeless maxillary molars often requires a sinus elevation procedure to ideally place the implants to accept future prosthesis. Maxillary sinus elevation surgery is a procedure used to increase the volume of bone mass so that dental implants can be placed. This article documents a sinus floor elevation technique through an extraction socket in a 65-year-old white male with chronic inflammation to increase the bone mass after the extraction of a periodontally involved maxillary molar tooth. Computerized tomography revealed an increased thickness of the sinus membrane, which was attributed to possible chronic sinus inflammation and periodontal inflammation. After consultation with the Department of Otolaryngology, it was diagnosed as chronic inflammation without any contraindication for sinus elevation surgery or implant placement. One month after the extraction, the sinus floor elevation surgery was performed through the extraction socket, and implants were placed 4 months later. An uneventful healing was noted after 6 months of osseointegration; two porcelain-fused-to-metal crowns were fabricated. Clinical follow-up took place every 3 months for 3 years, and successful healing was achieved. The patient was satisfied with the esthetic and functional results of the oral rehabilitation. Sinus floor elevation through an extraction socket without any residual bone, followed by dental implant placement, provided successful functional results and acceptable stability.

Can dead man tooth do tell tales? Tooth prints in forensic identification.

PubMed

Christopher, Vineetha; Murthy, Sarvani; Ashwinirani, S R; Prasad, Kulkarni; Girish, Suragimath; Vinit, Shashikanth Patil

2017-01-01

We know that teeth trouble us a lot when we are alive, but they last longer for thousands of years even after we are dead. Teeth being the strongest and resistant structure are the most significant tool in forensic investigations. Patterns of enamel rod end on the tooth surface are known as tooth prints. This study is aimed to know whether these tooth prints can become a forensic tool in personal identification such as finger prints. A study has been targeted toward the same. In the present in-vivo study, acetate peel technique has been used to obtain the replica of enamel rod end patterns. Tooth prints of upper first premolars were recorded from 80 individuals after acid etching using cellulose acetate strips. Then, digital images of the tooth prints obtained at two different intervals were subjected to biometric conversion using Verifinger standard software development kit version 6.5 software followed by the use of Automated Fingerprint Identification System (AFIS) software for comparison of the tooth prints. Similarly, each individual's finger prints were also recorded and were subjected to the same software. Further, recordings of AFIS scores obtained from images were statistically analyzed using Cronbach's test. We observed that comparing two tooth prints taken from an individual at two intervals exhibited similarity in many cases, with wavy pattern tooth print being the predominant type. However, the same prints showed dissimilarity when compared with other individuals. We also found that most of the individuals with whorl pattern finger print showed wavy pattern tooth print and few loop type fingerprints showed linear pattern of tooth prints. Further more experiments on both tooth prints and finger prints are required in establishing an individual's identity.

Can dead man tooth do tell tales? Tooth prints in forensic identification

PubMed Central

Christopher, Vineetha; Murthy, Sarvani; Ashwinirani, S. R.; Prasad, Kulkarni; Girish, Suragimath; Vinit, Shashikanth Patil

2017-01-01

Background: We know that teeth trouble us a lot when we are alive, but they last longer for thousands of years even after we are dead. Teeth being the strongest and resistant structure are the most significant tool in forensic investigations. Patterns of enamel rod end on the tooth surface are known as tooth prints. Aim: This study is aimed to know whether these tooth prints can become a forensic tool in personal identification such as finger prints. A study has been targeted toward the same. Settings and Design: In the present in-vivo study, acetate peel technique has been used to obtain the replica of enamel rod end patterns. Materials and Methods: Tooth prints of upper first premolars were recorded from 80 individuals after acid etching using cellulose acetate strips. Then, digital images of the tooth prints obtained at two different intervals were subjected to biometric conversion using Verifinger standard software development kit version 6.5 software followed by the use of Automated Fingerprint Identification System (AFIS) software for comparison of the tooth prints. Similarly, each individual's finger prints were also recorded and were subjected to the same software. Statistical Analysis: Further, recordings of AFIS scores obtained from images were statistically analyzed using Cronbach's test. Results: We observed that comparing two tooth prints taken from an individual at two intervals exhibited similarity in many cases, with wavy pattern tooth print being the predominant type. However, the same prints showed dissimilarity when compared with other individuals. We also found that most of the individuals with whorl pattern finger print showed wavy pattern tooth print and few loop type fingerprints showed linear pattern of tooth prints. Conclusions: Further more experiments on both tooth prints and finger prints are required in establishing an individual's identity. PMID:28584483

How to Prevent Tooth Decay in Your Baby

MedlinePlus

... life-threatening infections. Tooth decay (called early childhood caries) is the most common chronic infectious disease of childhood. Tooth decay may also be called nursing caries or baby bottle tooth decay . Healthy dental habits ...

Effect of tooth brushing on gloss retention and surface roughness of five bulk-fill resin composites.

PubMed

O'Neill, Catherine; Kreplak, Laurent; Rueggeberg, Frederick A; Labrie, Daniel; Shimokawa, Carlos Alberto Kenji; Price, Richard Bengt

2018-01-01

To determine the effects of tooth brushing on five bulk-fill resin based composites (RBCs). Ten samples of Filtek Supreme Enamel (control), Filtek One Bulk Fill, Tetric EvoCeram Bulk Fill, SonicFill 2, SDR flow+, and Admira Fusion X-tra were light cured for 20 seconds using the Valo Grand curing light. After 24 hours storage in air at 37°C, specimens were brushed in a random order using Colgate OpticWhite dentifrice and a soft toothbrush. Surface gloss was measured prior to brushing, after 5,000, 10,000 and 15,000 back and forth brushing cycles. Surface roughness was measured after 15,000 brushing cycles using atomic force microscopy (AFM) and selected scanning electron microscope (SEM) images were taken. The data was examined using ANOVA and pair-wise comparisons using Scheffe's post-hoc multiple comparison tests (α = 0.05). Surface gloss decreased and the surface roughness increased after brushing. Two-way ANOVA showed that both the RBC and the number of brushing cycles had a significant negative effect on the gloss. One-way ANOVA showed that the RBC had a significant effect on the roughness after 15,000 brushing cycles. For both gloss and roughness, brushing had the least effect on the nano-filled control and nano-filled bulk-fill RBC, and the greatest negative effect on Admira Fusion X-tra. The SEM images provided visual agreement. There was an excellent linear correlation (R 2  = 0.98) between the logarithm of the gloss and roughness. After brushing, the bulk-fill RBCs were all rougher than the control nano-filled RBC. The nano-filled bulk-fill RBC was the least affected by brushing. Bulk-fill RBCs lose their gloss faster and become rougher than the nanofilled conventional RBC, Filtek Supreme Ultra. The nanofilled bulk-fill RBC was the least affected by tooth brushing. © 2017 Wiley Periodicals, Inc.

CMT2C with vocal cord paresis associated with short stature and mutations in the TRPV4 gene

PubMed Central

Chen, D.-H.; Sul, Y.; Weiss, M.; Hillel, A.; Lipe, H.; Wolff, J.; Matsushita, M.; Raskind, W.; Bird, T.

2010-01-01

Background: Recently, mutations in the transient receptor potential cation channel, subfamily V, member 4 gene (TRPV4) have been reported in Charcot-Marie-Tooth Type 2C (CMT2C) with vocal cord paresis. Other mutations in this same gene have been described in separate families with various skeletal dysplasias. Further clarification is needed of the different phenotypes associated with this gene. Methods: We performed clinical evaluation, electrophysiology, and genetic analysis of the TRPV4 gene in 2 families with CMT2C. Results: Two multigenerational families had a motor greater than sensory axonal neuropathy associated with variable vocal cord paresis. The vocal cord paresis varied from absent to severe, requiring permanent tracheotomy in 2 subjects. One family with mild neuropathy also manifested pronounced short stature, more than 2 SD below the average height for white Americans. There was one instance of dolichocephaly. A novel S542Y mutation in the TRPV4 gene was identified in this family. The other family had a more severe, progressive, motor neuropathy with sensory loss, but less remarkable short stature and an R315W mutation in TRPV4. Third cranial nerve involvement and sleep apnea occurred in one subject in each family. Conclusion: CMT2C with axonal neuropathy, vocal cord paresis, and short stature is a unique syndrome associated with mutations in the TRPV4 gene. Mutations in TRPV4 can cause abnormalities in bone, peripheral nerve, or both and may result in highly variable orthopedic and neurologic phenotypes. GLOSSARY CMAP = compound muscle action potential; CMT = Charcot-Marie-Tooth; CMT2C = Charcot-Marie-Tooth Type 2C; HMSN = hereditary motor and sensory neuropathy; NCV = nerve conduction velocity; RFLP = restriction fragment length polymorphism; SMA = spinal muscular atrophy; SNAP = sensory nerve action potential; SPSMA = scapuloperoneal spinal muscular atrophy. PMID:21115951

Regenerative endodontic treatment of an immature tooth with a necrotic pulp and apical periodontitis using platelet-rich plasma (PRP) and mineral trioxide aggregate (MTA): a case report.

PubMed

Sachdeva, G S; Sachdeva, L T; Goel, M; Bala, S

2015-09-01

To report the successful clinical and radiographic outcome of a regenerative endodontic treatment. A 16-year-old male patient presented with a discoloured, maxillary left lateral incisor with a necrotic pulp. Radiographic examination revealed an incompletely developed root with an open apex. Under local anaesthesia and rubber dam isolation, an access cavity was prepared and the necrotic pulpal remnants were removed. The canal was disinfected without mechanical instrumentation with 5.25% NaOCl solution and dried with sterile paper points. A triple antibiotic (metronidazole, ciprofloxacin and minocycline) mixed with distilled water was packed in the canal and left for 28 days. Ten millimetres of whole blood was drawn by venipuncture from the patients antecubital vein for preparation of platelet-rich plasma (PRP). After removal of the antibiotic mixture, the PRP was injected into the canal space up to the cementoenamel junction level. Three millimetres of white MTA was placed directly over the PRP clot. Two days later, the tooth was restored with permanent filling materials. The patient was recalled for 3, 6, 12, 24 and 36 months clinical/radiographic follow-up. A 3-year follow-up radiograph revealed resolution of the periapical lesion, increased thickening of the root walls, further root development and continued apical closure of the root apex. The tooth was not responsive to cold tests; however, sensitivity tests with an electric pulp tester (EPT) elicited a delayed positive response. Regeneration is a viable treatment modality that allows continued root development of immature teeth with open apices and necrotic pulps. Platelet-rich plasma appears to be a suitable scaffold for regeneration of vital tissues in teeth with a necrotic pulps and an associated periapical lesion. Regenerative endodontic procedures may offer an effective treatment option to save teeth with compromised structural integrity. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Spectrophotometric Analysis of Coronal Tooth Discoloration Induced by Various Bioceramic Cements and Other Endodontic Materials.

PubMed

Kohli, Meetu R; Yamaguchi, Maimi; Setzer, Frank C; Karabucak, Bekir

2015-11-01

Coronal tooth discoloration induced by various endodontic materials was evaluated in vitro. Eighty extracted human maxillary anterior teeth were accessed, instrumented, and sectioned to standardized root lengths of 10 mm below the cementoenamel junction. Pulp chambers were cleaned chemomechanically to ensure complete tissue removal. Specimens were filled with experimental materials in 8 random groups: RRM, EndoSequence RRM putty (Brasseler, Savannah, GA); RRMF, EndoSequence RRM fast set paste (Brasseler); BD, Biodentine (Septodont, Saint-Maur-des-Fossés, France); WMTA, white MTA (Dentsply, York, PA), GMTA, gray MTA (Dentsply); AH+, AH Plus sealer (Dentsply); TAP, triple antibiotic paste (metronidazole, ciprofloxacin, and minocycline); and NF, no filling (negative control group). After incubation in 100% humidity at 37°C, color changes were evaluated with a spectrophotometer (Ocean Optics, Dunedin, FL) on days 0, 7, 30, 60, and 180 after material placement (T0-T180). Data were transformed into Commission International de I'Eclairage's L*a*b color values, and corresponding ΔE values were calculated. Two-way analysis of variance and the Bonferroni method were performed. Visual discoloration was observed in all specimens in the GMTA, WMTA, and TAP groups at T7, increasing with time. The ΔE value between the initial color at T0 and at T7, T30, T60, and T180 was significantly different for GMTA, WMTA, and TAP (P < .001). ΔE values for the BD, RRM, RRMF, AH+, and NF groups were not statistically significantly different between T0 and T7, T30, T60, and T180, respectively, except for 3 samples below the human perceptible threshold. Values of L* dropped significantly from T0 to T180 in the TAP, GMTA, and WMTA groups. Significant coronal tooth discoloration was caused by TAP, GMTA, and WMTA but not by BD, RRM, and RRMF. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Socioeconomic and ethnic inequalities in oral health among children and adolescents living in England, Wales and Northern Ireland.

PubMed

Rouxel, Patrick; Chandola, Tarani

2018-06-10

Although adolescence is a sensitive developmental period in oral health, the social equalization hypothesis that suggests health inequalities attenuate in adolescence has not been examined. This study analyses whether the socioeconomic gap and ethnic disadvantage in oral health among children aged 5 reduces among adolescents aged 15. Data from the cross-sectional Children's Dental Health Survey 2013 were analysed, comprising of 8541 children aged 5, 8, 12 and 15 attending schools in England, Wales and Northern Ireland. Oral health indicators included decayed and filled teeth, plaque, gingivitis and periodontal health. Ethnicity was measured using the 2011 UK census ethnic categories. Socioeconomic position was measured by family, school and residential deprivation. Negative binomial and probit regression models estimated the levels of oral health by ethnicity and socioeconomic position, adjusted for demographic and tooth characteristics. The predicted rate of decayed teeth for White British/Irish children aged 5 was 1.54 (95%CI 1.30-1.77). In contrast, the predicted rate for Indian and Pakistani children was about 2-2.5 times higher. At age 15, ethnic differences had reduced considerably. Family deprivation was associated with higher levels of tooth decay among younger children but not among adolescents aged 15. The influence of residential deprivation on the rate of tooth decay and filled teeth was similar among younger and older children. Moreover, inequalities in poor periodontal health by residential deprivation was significantly greater among 15-year-old children compared to younger children. This study found some evidence of smaller ethnic and family socioeconomic differences in oral health among British adolescents compared to younger children. However, substantial differences in oral health by residential deprivation remain among adolescents. Community levels of deprivation may be particularly important for the health of adolescents. © 2018 The Authors. Community Dentistry and Oral Epidemiology Published by John Wiley & Sons Ltd.

Tooth loss patterns in older adults with special needs: a Minnesota cohort

PubMed Central

Chen, Xi; Clark, Jennifer J

2011-01-01

This study was conducted to detail tooth loss patterns in older adults with special needs. A total of 491 elderly subjects with special needs were retrospectively selected and followed during 10/1999-12/2006. Medical, dental, cognitive, and functional assessments were abstracted from dental records and used to predict risk of tooth loss. Tooth loss events were recorded for subjects during follow-up. Chi-squared tests were used to study the association between tooth loss and the selected risk factors. Logistic, poisson, and negative binomial regressions were developed to study tooth loss patterns. Overall, 27% of the subjects lost at least one tooth during follow-up. Fourteen subjects had tooth loss events per 100 person-years. Tooth loss pattern did not differ significantly among different special-needs subgroups (i.e. community-dwelling vs. long-term care, physically disabled vs. functionally independent). Special-needs subjects with three or more active dental conditions at arrival had more than twice the risk of losing teeth than those without any existing conditions. After adjusting other factors, the number of carious teeth or retained roots at arrival was a significant predictor of tooth loss for older adults with special needs (P=0.001). These findings indicate that appropriately managing active caries and associated conditions is important to prevent tooth loss for older adults with special needs. PMID:21449213

[Establishment of database with standard 3D tooth crowns based on 3DS MAX].

PubMed

Cheng, Xiaosheng; An, Tao; Liao, Wenhe; Dai, Ning; Yu, Qing; Lu, Peijun

2009-08-01

The database with standard 3D tooth crowns has laid the groundwork for dental CAD/CAM system. In this paper, we design the standard tooth crowns in 3DS MAX 9.0 and create a database with these models successfully. Firstly, some key lines are collected from standard tooth pictures. Then we use 3DS MAX 9.0 to design the digital tooth model based on these lines. During the design process, it is important to refer to the standard plaster tooth model. After some tests, the standard tooth models designed with this method are accurate and adaptable; furthermore, it is very easy to perform some operations on the models such as deforming and translating. This method provides a new idea to build the database with standard 3D tooth crowns and a basis for dental CAD/CAM system.

A windowing and mapping strategy for gear tooth fault detection of a planetary gearbox

NASA Astrophysics Data System (ADS)

Liang, Xihui; Zuo, Ming J.; Liu, Libin

2016-12-01

When there is a single cracked tooth in a planet gear, the cracked tooth is enmeshed for very short time duration in comparison to the total time of a full revolution of the planet gear. The fault symptom generated by the single cracked tooth may be very weak. This study aims to develop a windowing and mapping strategy to interpret the vibration signal of a planetary gear at the tooth level. The fault symptoms generated by a single cracked tooth of the planet gear of interest can be extracted. The health condition of the planet gear can be assessed by comparing the differences among the signals of all teeth of the planet gear. The proposed windowing and mapping strategy is tested with both simulated vibration signals and experimental vibration signals. The tooth signals can be successfully decomposed and a single tooth fault on a planet gear can be effectively detected.

A new method for measuring nocturnal tooth contacts.

PubMed

Yamashita, S; Ai, M; Mizutani, H

1993-09-01

A new portable system for measuring nocturnal tooth contacts has been devised. This system was suitable for patients to take home and record tooth contacts by themselves. A micro photo sensor using optical fibres was applied to detect tooth contacts. The sensor and the target were accurately fixed to opposed molars, respectively on the same side, with removable metal attachments. Patients were instructed to set the attachment to their tooth each experimental night. In the present study, data was assembled for four or five nights in three subjects who were free of masticatory pain and dysfunction. Each subject showed an individual tooth contact pattern. It is suggested that this new system is useful and convenient for measuring nocturnal tooth contacts.

Nucleolus organizer regions and B-chromosomes of wood mice (mammalia, rodentia, Apodemus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boeskorov, G.G.; Kartavtseva, I.V.; Zagorodnyuk, I.V.

1995-02-01

Distribution of nucleolus organizer regions (NORs) in karyotypes was studied in 10 species of wood mice, including Apodemus flavicollis, A. sylvaticus, A. uralensis (=A. microps), A. fulvipectus (=A. falzfeini), A. ponticus, A. hyrcanicus, A. mystacinus, A. agrarius, A. peninsulae, and A. speciosus. Peculiarities of NOR location in karyotypes can be used in interspecific diagnostics of wood mice. Intraspecific polymorphism of A. sylvaticus, A. agrarius, and A. peninsulae in terms of the number of NORs and their localization in chromosomes can serve as evidence for karyological differentiation in certain populations of these species. The minimum number of active NORs in micemore » of the genus Apodemus is two to four. Two A. flavicollis wood mice with karyotypes containing one small acrocentric B-chromosome (2n = 49) were identified among animals captured in Estonia. In A. peninsulae, B-chromosomes were found among animals captured in the following regions: the vicinity of Kyzyl (one mouse with 17 microchromosomes, 2n = 65); the vicinity of Birakan (two mice with one metacentric chromosome each, 2n = 49); and in the Ussuri Nature Reserve (one mouse with five B-chromosomes, including three metacentric and two dotlike chromosomes; 2n = 53). In the latter animal, the presence of NORs on two metacentric B-chromosomes was revealed; this is the first case of identification of active NORs on extra chromosomes of mammals. 29 refs., 4 figs., 1 tab.« less

Pseudo-Outbreak of Actinomyces graevenitzii Associated with Bronchoscopy

PubMed Central

Peaper, David R.; Havill, Nancy L.; Aniskiewicz, Michael; Callan, Deborah; Pop, Olivia; Towle, Dana

2014-01-01

Outbreaks and pseudo-outbreaks of infection related to bronchoscopy typically involve Gram-negative bacteria, Mycobacterium species or Legionella species. We report an unusual bronchoscopy-related pseudo-outbreak due to Actinomyces graevenitzii. Extensive epidemiological and microbiological investigation failed to identify a common source. Strain typing revealed that the cluster was comprised of heterogeneous strains of A. graevenitzii. A change in laboratory procedures for Actinomyces cultures was coincident with the emergence of the pseudo-outbreak, and we determined that A. graevenitzii isolates more readily adopted a white, dry, molar tooth appearance on anaerobic colistin nalidixic acid (CNA) agar which likely facilitated its detection and identification in bronchoscopic specimens. This unusual pseudo-outbreak was related to frequent requests of bronchoscopists for Actinomyces cultures combined with a change in microbiology laboratory practices. PMID:25355767

Diversity in tooth eruption and life history in humans: illustration from a Pygmy population

PubMed Central

Ramirez Rozzi, Fernando

2016-01-01

Life history variables (LHV) in primates are closely correlated with the ages of tooth eruption, which are a useful proxy to predict growth and development in extant and extinct species. However, it is not known how tooth eruption ages interact with LHV in polymorphic species such as modern humans. African pygmies are at the one extreme in the range of human size variation. LHV in the Baka pygmies are similar to those in standard populations. We would therefore expect tooth eruption ages to be similar also. This mixed (longitudinal and cross-sectional) study of tooth eruption in Baka individuals of known age reveals that eruption in all tooth classes occurs earlier than in any other human population. Earlier tooth eruption can be related to the particular somatic growth in the Baka but cannot be correlated with LHV. The link between LHV and tooth eruption seems disrupted in H. sapiens, allowing adaptive variations in tooth eruption in response to different environmental constraints while maintaining the unique human life cycle. PMID:27305976

[Application of micro-power system in the surgery of tooth extraction].

PubMed

Kaijin, Hu; Yongfeng, Li

2015-02-01

Tooth extraction is a common operation in oral surgery. Traditional-extraction instruments, such as bone chisel, elevator, and bone hammer, lead to not only severe trauma but also unnecessary complications, and patients easily become nervous and apprehensive if tooth extraction is performed using these violent instruments. In recent years, with the develop- ment of minimally invasive concept and technology, various micro-power instruments have been used for tooth extraction. This innovative technology can reduce the iatrogenic trauma and complications of tooth extraction. Additionally, this technology can greatly decrease the patient's physical and mental pressure. The new equipment compensates for the deficiency of traditional tooth extraction equipment and facilitates the gradual replacement of the latter. Diverse micro-power systems have distinct strengths and weaknesses, so some auxiliary instruments are still needed during tooth extraction. This paper focuses on the various micro-power systems for tooth extraction and tries to compare the advantages and disadvantages of these systems. Selection and usage of auxiliary equipment are also introduced. Thus, this paper provides reference for the proper application of the micro-power systems in tooth extraction.

Associations between bacteremia from oral sources and distant-site infections: tooth brushing versus single tooth extraction.

PubMed

Mougeot, Farah K Bahrani; Saunders, Sabrina E; Brennan, Michael T; Lockhart, Peter B

2015-04-01

To determine the impact of antibiotic prophylaxis (AP) on the incidence of bacteremia caused by oral bacterial species associated with infective endocarditis (IE) and prosthetic joint infections (PJIs) and to compare the incidence of following tooth brushing versus single tooth extraction. Bacterial species in blood following single tooth extraction, with or without AP, and tooth brushing(1) were compared with IE- and PJI-associated bacteria reported in the literature. Of the 98 bacterial species identified in blood following single tooth extraction and tooth brushing, 32(1) and 12 were species were associated with IE and PJI, respectively. AP decreased the frequency of IE- and PJI-causing oral bacterial species in blood; however, single tooth extraction versus brushing resulted in bacteremia with IE- and PJI-causing species with similar frequencies: 65% versus 56% for IE, and 31% versus 28% for PJI. Although AP significantly decreased the incidence of bacteremia, the similarity between the incidence of bacteremia following brushing and extraction undermines AP as an effective strategy for the prevention of these distant-site infections. Copyright © 2015 Elsevier Inc. All rights reserved.

The proximal gastric corpus is the most responsive site of motilin-induced contractions in the stomach of the Asian house shrew.

PubMed

Dudani, Amrita; Aizawa, Sayaka; Zhi, Gong; Tanaka, Toru; Jogahara, Takamichi; Sakata, Ichiro; Sakai, Takafumi

2016-07-01

The migrating motor complex (MMC) is responsible for emptying the stomach during the interdigestive period, in preparation for the next meal. It is known that gastric phase III of MMC starts from the proximal stomach and propagates the contraction downwards. We hypothesized that a certain region of the stomach must be more responsive to motilin than others, and that motilin-induced strong gastric contractions propagate from that site. Stomachs of the Suncus or Asian house shrew, a small insectivorous mammal, were dissected and the fundus, proximal corpus, distal corpus, and antrum were examined to study the effect of motilin using an organ bath experiment. Motilin-induced contractions differed in different parts of the stomach. Only the proximal corpus induced gastric contraction even at motilin 10(-10) M, and strong contraction was induced by motilin 10(-9) M in all parts of the stomach. The GPR38 mRNA expression was also higher in the proximal corpus than in the other sections, and the lowest expression was observed in the antrum. GPR38 mRNA expression varied with low expression in the mucosal layer and high expression in the muscle layer. Additionally, motilin-induced contractions in each dissected part of the stomach were inhibited by tetrodotoxin and atropine pretreatment. These results suggest that motilin reactivity is not consistent throughout the stomach, and an area of the proximal corpus including the cardia is the most sensitive to motilin.

Molecular systematics and biodiversity of the Cryptotis mexicanus group (Eulipotyphla: Soricidae): two new species from Honduras supported

USGS Publications Warehouse

Baird, Amy B.; McCarthy, Timothy J.; Trujillo, Robert G.; Kang, Yuan Yuan; Esmaeiliyan, Mehdi; Valdez, Joselyn; Woodman, Neal; Bickham, John W.

2018-01-01

Small-eared shrews of the genus Cryptotis (Mammalia: Eulipotyphla: Soricidae) are widespread in the northern Neotropics. Systematic studies of these shrews over the past two decades have revealed previously undocumented morphological and species diversity, resulting in a quadrupling of the number of recognized species. Unfortunately, a small proportion of the species in the genus have been included in molecular phylogenetic studies, and evolutionary relationships within the genus are incompletely known. Traditionally, species have been assigned to four or five morphologically defined ‘species groups’, but tests of the monophyly of some of these groups show weak support and relationships amongst species groups remain somewhat speculative. The largest species group is the C. mexicanus group inhabiting Mexico and northern Central America. We studied sequences from mitochondrial cytochrome-b and 16S genes, as well as nuclear ApoB and BRCA1 genes from 22 species of Cryptotis, including 15 species in the C. mexicanus group. Our combined analysis shows that the C. goldmani subgroup is very weakly supported as monophyletic; however, the C. mexicanus group as a whole is not monophyletic. Our molecular phylogenetic analyses confirm the distinctiveness of two newly described species (C. celaque and C. mccarthyi) from isolated highlands of western Honduras and illustrate their relationship with other species formerly considered part of a widespread C. goodwini.

Action of Bacopa monnieri to antagonize cisplatin-induced emesis in Suncus murinus (house musk shrew).

PubMed

Ullah, Ihsan; Subhan, Fazal; Lu, Zengbing; Chan, Sze Wa; Rudd, John A

2017-04-01

Bacopa monnieri (BM, family Scrophulariaceae) is used in several traditional systems of medicine for the management of epilepsy, depression, neuropathic pain, sleep disorders and memory deficits. The present study investigated the potential of BM methanol (BM-MetFr) and BM n-butanol fractions (BM-ButFr) to reduce chemotherapy-induced emesis in Suncus murinus (house musk shrew). Cisplatin (30 mg/kg, i.p.) reliably induced retching and/or vomiting over a 2 day period. BM-MetFr (10-40 mg/kg, s.c.) and BM-ButFr (5-20 mg/kg, s.c.) antagonized the retching and/or vomiting response by ∼59.4% (p < 0.05) and 78.9% (p < 0.05), respectively, while the 5-HT 3 receptor antagonist, palonosetron (0.5 mg/kg, s.c.), reduced the response by ∼71% (p < 0.05). The free radical scavenger/antioxidant, N-(2-mercaptopropionyl)-glycine (30-300 mg/kg, s.c.) reduced the retching and/or vomiting response occurring on day one non-significantly by 44% (p > 0.05). In conclusion, the n-butanol fractions of BM have anti-emetic activity comparable with palonosetron and MPG. BM may be useful alone or in combination with other anti-emetic drugs for the treatment of chemotherapy-induced emesis in man. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Multilocus phylogeny and cryptic diversity in Asian shrew-like moles (Uropsilus, Talpidae): implications for taxonomy and conservation

PubMed Central

2013-01-01

Background The genus Uropsilus comprises a group of terrestrial, montane mammals endemic to the Hengduan and adjacent mountains. These animals are the most primitive living talpids. The taxonomy has been primarily based on cursory morphological comparisons and the evolutionary affinities are little known. To provide insight into the systematics of this group, we estimated the first multi-locus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range. Results We obtained two mitochondrial genes (~1, 985 bp) and eight nuclear genes (~4, 345 bp) from 56 specimens. Ten distinct evolutionary lineages were recovered from the three recognized species, eight of which were recognized as species/putative species. Five of these putative species were found to be masquerading as the gracile shrew mole. The divergence time estimation results indicated that climate change since the last Miocene and the uplift of the Himalayas may have resulted in the diversification and speciation of Uropsilus. Conclusions The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. Two synonyms of gracilis (atronates and nivatus) should be given full species status, and the taxonomic status of another three potential species should be evaluated using extensive taxon sampling, comprehensive morphological, and morphometric approaches. Consequently, the conservation status of Uropsilus spp. should also be re-evaluated, as most of the species/potential species have very limited distribution. PMID:24161152

Predator-induced synchrony in population oscillations of coexisting small mammal species

PubMed Central

Korpimäki, Erkki; Norrdahl, Kai; Huitu, Otso; Klemola, Tero

2005-01-01

Comprehensive analyses of long-term (1977–2003) small-mammal abundance data from western Finland showed that populations of Microtus voles (field voles M. agrestis and sibling voles M. rossiaemeridionalis) voles, bank (Clethrionomys glareolus) and common shrews (Sorex araneus) fluctuated synchronously in 3 year population cycles. Time-series analyses indicated that interspecific synchrony is influenced strongly by density-dependent processes. Synchrony among Microtus and bank voles appeared additionally to be influenced by density-independent processes. To test whether interspecific synchronization through density-dependent processes is caused by predation, we experimentally reduced the densities of the main predators of small mammals in four large agricultural areas, and compared small mammal abundances in these to those in four control areas (2.5–3 km2) through a 3 year small-mammal population cycle. Predator reduction increased densities of the main prey species, Microtus voles, in all phases of the population cycle, while bank voles, the most important alternative prey of predators, responded positively only in the low and the increase phase. Manipulation also increased the autumn densities of water voles (Arvicola terrestris) in the increase phase of the cycle. No treatment effects were detected for common shrews or mice. Our results are in accordance with the alternative prey hypothesis, by which predators successively reduce the densities of both main and alternative prey species after the peak phase of small-mammal population cycles, thus inducing a synchronous low phase. PMID:15695211

Molecular epidemiological investigations of plague in Eastern Province of Zambia.

PubMed

Nyirenda, Stanley S; Hang Ombe, Bernard M; Simulundu, Edgar; Mulenga, Evans; Moonga, Ladslav; Machang U, Robert S; Misinzo, Gerald; Kilonzo, Bukheti S

2018-01-04

Plague is a flea-borne zoonotic and invasive disease caused by a gram negative coccobacillus bacterium called Yersinia pestis. Plague has caused three devastating pandemics globally namely: the Justinian, Black Death and Oriental plague. The disease in the Eastern Province of Zambia has been reported in Nyimba and Sinda Districts in the past 15 years. The aim of this study was to investigate the molecular epidemiology of plague in the two affected districts. Polymerase Chain Reaction (PCR), targeting Plasminogen activator gene (pla gene) of Y. pestis, was performed on suspected human bubo aspirates (n = 7), rodents (n = 216), shrews (n = 27) and fleas (n = 1494). Of these, one positive sample from each source or host was subjected to sequencing followed by phylogenetic analysis. The plasminogen activator gene (pla gene) of Y. pestis was detected in 42.8% bubo aspirates, 6.9% rodents, 3.7% shrew and 0.8% fleas. The fleas were from pigs (n = 4), goats (n = 5) and rodents (n = 3). The sequencing and phylogenetic analysis suggested that the pla gene of Y. pestis in Nyimba and Sinda was similar and the isolates demonstrated a high degree of evolutionary relationship with Antiqua strains from the Republic of Congo and Kenya. It can be concluded that pla gene of Y. pestis was present in various hosts in the two districts and the strains circulating in each district were similar and resembles those in the Republic of Congo and Kenya.

Shrews, rats, and a polecat in "the pardoner’s tale": Chapter 3

USGS Publications Warehouse

Feinstein, Sandy; Woodman, Neal; Van Dyke, Carolynn

2012-01-01

While historically existing animals and literary animal characters inform allegorical and metaphorical characterization in The Canterbury Tales, figurative usage does not erase recognition of the material animal. "The Pardoner's Tale," for one, challenges the terms of conventional animal metaphors by refocusing attention on common animals as common animals and common human creatures as something worse than vermin. Most attention has been paid to the larger animals-goat, hare, and horse-that constitute the physical portrait of Chaucer's Pardoner in the "General Prologue" and in the prologue to his tale.! Like these animals, rats and a polecat, together with rhetorical shrews, appear in this tale as well as in other literature, including bestiaries and natural histories. Equally to the purpose, these animals could be physically observed as constituents of both urban and rural landscapes in fourteenth-century England.2 In the Middle Ages, animals were part of the environment as well as part of the culture: they lived inside as well as outside the city gates, priory walls, and even domestic spaces; a rat in the street or the garden might not be any less welcome or uncommon than encountering someone's horses and goats nibbling vegetation or blocking a passage. Not being out of the ordinary, though, such animals could (and can) be overlooked or dismissed as com­mon, too familiar to register. This chapter reveals why readers and listeners should pay close attention to the things they think they know and what they hear about what they think they know.

Phylogeny and origins of hantaviruses harbored by bats, insectivores, and rodents.

PubMed

Guo, Wen-Ping; Lin, Xian-Dan; Wang, Wen; Tian, Jun-Hua; Cong, Mei-Li; Zhang, Hai-Lin; Wang, Miao-Ruo; Zhou, Run-Hong; Wang, Jian-Bo; Li, Ming-Hui; Xu, Jianguo; Holmes, Edward C; Zhang, Yong-Zhen

2013-02-01

Hantaviruses are among the most important zoonotic pathogens of humans and the subject of heightened global attention. Despite the importance of hantaviruses for public health, there is no consensus on their evolutionary history and especially the frequency of virus-host co-divergence versus cross-species virus transmission. Documenting the extent of hantavirus biodiversity, and particularly their range of mammalian hosts, is critical to resolving this issue. Here, we describe four novel hantaviruses (Huangpi virus, Lianghe virus, Longquan virus, and Yakeshi virus) sampled from bats and shrews in China, and which are distinct from other known hantaviruses. Huangpi virus was found in Pipistrellus abramus, Lianghe virus in Anourosorex squamipes, Longquan virus in Rhinolophus affinis, Rhinolophus sinicus, and Rhinolophus monoceros, and Yakeshi virus in Sorex isodon, respectively. A phylogenetic analysis of the available diversity of hantaviruses reveals the existence of four phylogroups that infect a range of mammalian hosts, as well as the occurrence of ancient reassortment events between the phylogroups. Notably, the phylogenetic histories of the viruses are not always congruent with those of their hosts, suggesting that cross-species transmission has played a major role during hantavirus evolution and at all taxonomic levels, although we also noted some evidence for virus-host co-divergence. Our phylogenetic analysis also suggests that hantaviruses might have first appeared in Chiroptera (bats) or Soricomorpha (moles and shrews), before emerging in rodent species. Overall, these data indicate that bats are likely to be important natural reservoir hosts of hantaviruses.

Relationship between food habits and tooth erosion occurrence in Malaysian University students.

PubMed

Manaf, Zahara Abdul; Lee, Mei Tee; Ali, Nor Hazirah Muhammad; Samynathan, Selvamary; Jie, Ying Phor; Ismail, Noor Hasnani; Bibiana Hui Ying, Yong; Wei Seng, Yeo; Yahya, Nurul Asyikin

2012-04-01

Tooth erosion is a growing dental problem; however, the role of diet in the aetiology of tooth erosion is unclear. A cross-sectional study was conducted to determine the association between tooth erosion occurrence and the consumption of acidic foods and drinks among undergraduate university students. A total of 150 undergraduate students (33 males and 117 females) aged 19 to 24 years at Universiti Kebangsaan Malaysia participated in this study. The Basic Erosive Wear Examination was used to assess the occurrence of tooth erosion. Information regarding dental hygiene practices, usual dietary habits, and consumption of acidic foods and drinks was obtained through a structured questionnaire. In all, 68% of subjects had tooth erosion. Subjects who reported having received information about healthy eating were less likely to have tooth erosion (χ(2) [1, N = 150] = 7.328, P = 0.007). The frequencies of milk (OR = 0.29, 95% CI = 0.13-0.67) and tea/coffee (adjusted OR = 0.42, 95% CI = 0.19-0.95) consumption were negatively associated with tooth erosion. Dental hygiene practice, the frequency and amount of acidic food and drink intake, and body mass index classification were not significantly associated with the risk of tooth erosion (P > 0.05). A high prevalence of tooth erosion was observed among this group of students. Preventive measures, such as dietary advice and increased consumption of milk at a younger age, may reduce the occurrence of tooth erosion among this age group.

Relationship between Food Habits and Tooth Erosion Occurrence in Malaysian University Students

PubMed Central

Zahara, Abdul Manaf; Mei Tee, Lee; Nor Hazirah, Muhammad Ali; Selvamary, Samynathan; Ying Phor, Jie; Noor Hasnani, Ismail; Bibiana Hui Ying, Yong; Wei Seng, Yeo; Nurul Asyikin, Yahya

2012-01-01

Background: Tooth erosion is a growing dental problem; however, the role of diet in the aetiology of tooth erosion is unclear. A cross-sectional study was conducted to determine the association between tooth erosion occurrence and the consumption of acidic foods and drinks among undergraduate university students. Methods: A total of 150 undergraduate students (33 males and 117 females) aged 19 to 24 years at Universiti Kebangsaan Malaysia participated in this study. The Basic Erosive Wear Examination was used to assess the occurrence of tooth erosion. Information regarding dental hygiene practices, usual dietary habits, and consumption of acidic foods and drinks was obtained through a structured questionnaire. Results: In all, 68% of subjects had tooth erosion. Subjects who reported having received information about healthy eating were less likely to have tooth erosion (χ2 [1, N = 150] = 7.328, P = 0.007). The frequencies of milk (OR = 0.29, 95% CI = 0.13–0.67) and tea/coffee (adjusted OR = 0.42, 95% CI = 0.19–0.95) consumption were negatively associated with tooth erosion. Dental hygiene practice, the frequency and amount of acidic food and drink intake, and body mass index classification were not significantly associated with the risk of tooth erosion (P > 0.05). Conclusion: A high prevalence of tooth erosion was observed among this group of students. Preventive measures, such as dietary advice and increased consumption of milk at a younger age, may reduce the occurrence of tooth erosion among this age group. PMID:22973138

Dental Erosion and Medical Conditions: An Overview of Aetiology, Diagnosis and Management.

PubMed

Paryag, A; Rafeek, R

2014-09-01

Tooth wear or tooth surface loss is a normal physiological process and occurs throughout life but is considered pathological when the degree of destruction is excessive or the rate of loss is rapid, causing functional, aesthetic or sensitivity problems. The importance of tooth wear as a dental problem has been increasingly recognized. The findings of a study in Trinidad indicate that the prevalence of tooth wear in a Trinidadian population is comparable to the United Kingdom (UK) and, indeed, that the level of moderate and severe wear is in fact nearly twice as high. The aetiology of tooth wear is attributed to four causes: erosion, attrition, abrasion and abfraction. Erosion is generally considered to be the most prevalent cause of tooth wear in the UK and Europe. Acids that cause dental erosion originate mainly from the diet or the stomach and to a lesser extent, the environment. Underlying medical problems can contribute to the progress of tooth wear due to erosion and the patient may not be aware of these conditions. Moderate to severe tooth wear poses a significant clinical challenge to dental practitioners and may result in treatment that is more complex and costly to the patient both in terms of finances and time spent in the dental chair. This paper provides an overview of aetiology and diagnosis of tooth wear, in particular tooth wear due to erosion, so that medical and dental practitioners may recognize tooth wear early, institute preventive measures and manage patients appropriately.

Dental Erosion and Medical Conditions An Overview of Aetiology, Diagnosis and Management

PubMed Central

Paryag, A; Rafeek, R

2014-01-01

ABSTRACT Tooth wear or tooth surface loss is a normal physiological process and occurs throughout life but is considered pathological when the degree of destruction is excessive or the rate of loss is rapid, causing functional, aesthetic or sensitivity problems. The importance of tooth wear as a dental problem has been increasingly recognized. The findings of a study in Trinidad indicate that the prevalence of tooth wear in a Trinidadian population is comparable to the United Kingdom (UK) and, indeed, that the level of moderate and severe wear is nearly twice as high. The aetiology of tooth wear is attributed to four causes: erosion, attrition, abrasion and abfraction. Erosion is generally considered to be the most prevalent cause of tooth wear in the UK and Europe. Acids that cause dental erosion originate mainly from the diet or the stomach and, to a lesser extent, the environment. Underlying medical problems can contribute to influence the progress of tooth wear due to erosion and the patient may not be aware of these conditions. Moderate to severe tooth wear poses a significant clinical challenge to dental practitioners and may result in treatment that is more complex and costly to the patient, both in terms of finances and time spent in the dental chair. This paper provides an overview of aetiology and diagnosis of tooth wear, in particular tooth wear due to erosion, so that medical and dental practitioners may recognize tooth wear early, institute preventive measures and manage patients appropriately. PMID:25781289

Pre-existing Periapical Inflammatory Condition Exacerbates Tooth Extraction–induced BRONJ Lesions in Mice

PubMed Central

Song, Minju; Alshaikh, Abdullah; Kim, Terresa; Kim, Sol; Dang, Michelle; Mehrazarin, Shebli; Shin, Ki-Hyuk; Kang, Mo; Park, No-Hee; Kim, Reuben H.

2016-01-01

Introduction Surgical interventions such as tooth extraction increase a chance of developing osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonates (BPs) for treatment of bone-related diseases. Tooth extraction is often performed to eliminate pre-existing pathological inflammatory conditions that make the tooth unsalvageable; however, the role of such conditions on bisphosphonate-related ONJ (BRONJ) development following tooth extraction is not clearly defined. Here, we examined the effects of periapical periodontitis on tooth extraction-induced BRONJ development in mice. Methods Periapical periodontitis was induced by exposing the pulp of the maxillary first molar for 3 weeks in C57/BL6 mice that were intravenously administered with BP. The same tooth was extracted, and after 3 additional weeks, the mice were harvested for histological, histomorphometric, and histochemical staining analyses. Results Pulp exposure induced periapical radiolucency as demonstrated by increased inflammatory cells, TRAP+ osteoclasts, and bone resorption. When BP was administered, pulp exposure did not induce apical bone resorption despite the presence of inflammatory cells and TRAP+ osteoclasts. While tooth extraction alone induced BRONJ lesions, pulp exposure further increased tooth extraction-induced BRONJ development as demonstrated by the presence of more bone necrosis. Conclusion Our study demonstrates that pre-existing pathological inflammatory condition such as periapical periodontitis is a predisposing factor that may exacerbate BRONJ development following tooth extraction. Our study further provides a clinical implication whereby periapical periodontitis should be controlled before performing tooth extraction in BP-users in order to reduce the risk of developing BRONJ. PMID:27637460

Minimizing the extra-oral time in autogeneous tooth transplantation: use of computer-aided rapid prototyping (CARP) as a duplicate model tooth.

PubMed

Lee, Seung-Jong; Kim, Euiseong

2012-08-01

The maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique. Briefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth. The average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model. These data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation.

Impact of bisphosphonate drug burden in alveolar bone during orthodontic tooth movement in a rat model: a pilot study.

PubMed

Kaipatur, Neelambar R; Wu, Yuchin; Adeeb, Samer; Stevenson, Thomas R; Major, Paul W; Doschak, Michael R

2013-10-01

The aim of this pilot study was to investigate the effect of long-term bisphosphonate drug use (bone burden) on orthodontic tooth movement in a rat model. Sprague Dawley rats were used for orthodontic protraction of the maxillary first molars with nickel-titanium coil springs and temporary anchorage devices as anchorage. Four groups of 5 rats each were included in the study; the first 2 groups were dosed with alendronate or a vehicle during concurrent orthodontic tooth movement. The third and fourth groups were pretreated for 3 months with alendronate or vehicle injections, and bisphosphonate drug treatment was discontinued before orthodontic tooth movement. Tooth movement measurements were obtained at 0, 4, and 8 weeks using high-resolution in-vivo microcomputed tomography, and the tissues were analyzed with histology and dynamic labeling of bone turnover. Appreciable tooth movement was achieved during the 8-week duration of this study with nickel-titanium coil springs and temporary anchorage devices. Both bisphosphonate treatment groups exhibited reduced tooth movement compared with the vehicle-dosed controls with a tendency toward more severe reduction in the bisphosphonate predosed group. Concurrent dosing of the bisphosphonate drug resulted in 56% and 65% reductions in tooth protraction at the 4-week and 8-week times, respectively. The impact of bisphosphonate bone burden in retarding tooth movement was even greater, with 77% and 86% reductions in tooth movement at 4 and 8 weeks, respectively. In this study, we used a robust rat model of orthodontic tooth movement with temporary anchorage devices. It has provided evidence that the bone burden of previous bisphosphonate use will significantly inhibit orthodontic tooth movement. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Endodontic Treatment of an Anomalous Anterior Tooth with the Aid of a 3-dimensional Printed Physical Tooth Model.

PubMed

Byun, Chanhee; Kim, Changhwan; Cho, Seungryong; Baek, Seung Hoon; Kim, Gyutae; Kim, Sahng G; Kim, Sun-Young

2015-06-01

Endodontic treatment of tooth formation anomalies is a challenge to clinicians and as such requires a complete understanding of the aberrant root canal anatomy followed by careful root canal disinfection and obturation. Here, we report the use of a 3-dimensional (3D) printed physical tooth model including internal root canal structures for the endodontic treatment of a challenging tooth anomaly. A 12-year-old boy was referred for endodontic treatment of tooth #8. The tooth showed class II mobility with swelling and a sinus tract in the buccal mucosa and periapical radiolucency. The tooth presented a very narrow structure between the crown and root by distal concavity and a severely dilacerated root. Moreover, a perforation site with bleeding and another ditching site were identified around the cervical area in the access cavity. A translucent physical tooth model carrying the information on internal root canal structures was built through a 3-step process: data acquisition by cone-beam computed tomographic scanning, virtual modeling by image processing, and manufacturing by 3D printing. A custom-made guide jig was then fabricated to achieve a safe and precise working path to the root canal. Endodontic procedures including access cavity preparation were performed using the physical tooth model and the guide jig. At the 7-month follow-up, the endodontically treated tooth showed complete periapical healing with no clinical signs and symptoms. This case report describes a novel method of endodontic treatment of an anomalous maxillary central incisor with the aid of a physical tooth model and a custom-made guide jig via 3D printing technique. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Common developmental pathways link tooth shape to regeneration

PubMed Central

Fraser, Gareth J.; Bloomquist, Ryan F.; Streelman, J. Todd

2013-01-01

In many non-mammalian vertebrates, adult dentitions result from cyclical rounds of tooth regeneration wherein simple unicuspid teeth are replaced by more complex forms. Therefore and by contrast to mammalian models, the numerical majority of vertebrate teeth develop shape during the process of replacement. Here, we exploit the dental diversity of Lake Malawi cichlid fishes to ask how vertebrates generally replace their dentition and in turn how this process acts to influence resulting tooth morphologies. First, we used immunohistochemistry to chart organogenesis of continually replacing cichlid teeth and discovered an epithelial down-growth that initiates the replacement cycle via a labial proliferation bias. Next, we identified sets of co-expressed genes from common pathways active during de novo, lifelong tooth replacement and tooth morphogenesis. Of note, we found two distinct epithelial cell populations, expressing markers of dental competence and cell potency, which may be responsible for tooth regeneration. Related gene sets were simultaneously active in putative signaling centers associated with the differentiation of replacement teeth with complex shapes. Finally, we manipulated targeted pathways (BMP, FGF, Hh, Notch, Wnt/β-catenin) in vivo with small molecules and demonstrated dose-dependent effects on both tooth replacement and tooth shape. Our data suggest that the processes of tooth regeneration and tooth shape morphogenesis are integrated via a common set of molecular signals. This linkage has subsequently been lost or decoupled in mammalian dentitions where complex tooth shapes develop in first generation dentitions that lack the capacity for lifelong replacement. Our dissection of the molecular mechanics of vertebrate tooth replacement coupled to complex shape pinpoints aspects of odontogenesis that might be re-evolved in the lab to solve problems in regenerative dentistry. PMID:23422830

Hedgehog signaling is required at multiple stages of zebrafish tooth development.

PubMed

Jackman, William R; Yoo, James J; Stock, David W

2010-11-30

The accessibility of the developing zebrafish pharyngeal dentition makes it an advantageous system in which to study many aspects of tooth development from early initiation to late morphogenesis. In mammals, hedgehog signaling is known to be essential for multiple stages of odontogenesis; however, potential roles for the pathway during initiation of tooth development or in later morphogenesis are incompletely understood. We have identified mRNA expression of the hedgehog ligands shha and the receptors ptc1 and ptc2 during zebrafish pharyngeal tooth development. We looked for, but did not detect, tooth germ expression of the other known zebrafish hedgehog ligands shhb, dhh, ihha, or ihhb, suggesting that as in mammals, only Shh participates in zebrafish tooth development. Supporting this idea, we found that morphological and gene expression evidence of tooth initiation is eliminated in shha mutant embryos, and that morpholino antisense oligonucleotide knockdown of shha, but not shhb, function prevents mature tooth formation. Hedgehog pathway inhibition with the antagonist compound cyclopamine affected tooth formation at each stage in which we applied it: arresting development at early stages and disrupting mature tooth morphology when applied later. These results suggest that hedgehog signaling is required continuously during odontogenesis. In contrast, over-expression of shha had no effect on the developing dentition, possibly because shha is normally extensively expressed in the zebrafish pharyngeal region. We have identified previously unknown requirements for hedgehog signaling for early tooth initiation and later morphogenesis. The similarity of our results with data from mouse and other vertebrates suggests that despite gene duplication and changes in the location of where teeth form, the roles of hedgehog signaling in tooth development have been largely conserved during evolution.

Paleobiology: A Tooth for a Tooth.

PubMed

Johanson, Zerina

2017-02-06

Many vertebrates replace teeth through shedding of the functional tooth. New analyses of a fossil fish demonstrate that shedding involved tooth resorption, a primitive feature in bony fishes, but absent in sharks and their relatives. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

A probability distribution model of tooth pits for evaluating time-varying mesh stiffness of pitting gears

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Liu, Zongyao; Wang, Delong; Yang, Xiao; Liu, Huan; Lin, Jing

2018-06-01

Tooth damage often causes a reduction in gear mesh stiffness. Thus time-varying mesh stiffness (TVMS) can be treated as an indication of gear health conditions. This study is devoted to investigating the mesh stiffness variations of a pair of external spur gears with tooth pitting, and proposes a new model for describing tooth pitting based on probability distribution. In the model, considering the appearance and development process of tooth pitting, we model the pitting on the surface of spur gear teeth as a series of pits with a uniform distribution in the direction of tooth width and a normal distribution in the direction of tooth height, respectively. In addition, four pitting degrees, from no pitting to severe pitting, are modeled. Finally, influences of tooth pitting on TVMS are analyzed in details and the proposed model is validated by comparing with a finite element model. The comparison results show that the proposed model is effective for the TVMS evaluations of pitting gears.

Ontogenetic Tooth Reduction in Stenopterygius quadriscissus (Reptilia: Ichthyosauria): Negative Allometry, Changes in Growth Rate, and Early Senescence of the Dental Lamina

PubMed Central

Dick, Daniel G.; Maxwell, Erin E.

2015-01-01

We explore the functional, developmental, and evolutionary processes which are argued to produce tooth reduction in the extinct marine reptile Stenopterygius quadriscissus (Reptilia: Ichthyosauria). We analyze the relationship between mandible growth and tooth size, shape, and count, to establish an ontogenetic trend. The pattern in S. quadriscissus is consistent with hypotheses of tooth size reduction by neutral selection, and this unusual morphology (a functionally edentulous rostrum) was produced by a series of different evolutionary developmental changes that are known for other taxa showing tooth reduction and loss. Specifically, this species evolved functional edentulism by evolutionary changes in the growth allometry of the dentition and by altering growth rates through ontogeny. This observation supports previous hypotheses that S. quadriscissus underwent ontogenetic tooth reduction. Tooth reduction in S. quadriscissus may be caused by unique selective pressures resulting from prey choice and feeding behavior, expanding our current understanding of the mechanisms producing tooth reduction. PMID:26579712

Ontogenetic Tooth Reduction in Stenopterygius quadriscissus (Reptilia: Ichthyosauria): Negative Allometry, Changes in Growth Rate, and Early Senescence of the Dental Lamina.

PubMed

Dick, Daniel G; Maxwell, Erin E

2015-01-01

We explore the functional, developmental, and evolutionary processes which are argued to produce tooth reduction in the extinct marine reptile Stenopterygius quadriscissus (Reptilia: Ichthyosauria). We analyze the relationship between mandible growth and tooth size, shape, and count, to establish an ontogenetic trend. The pattern in S. quadriscissus is consistent with hypotheses of tooth size reduction by neutral selection, and this unusual morphology (a functionally edentulous rostrum) was produced by a series of different evolutionary developmental changes that are known for other taxa showing tooth reduction and loss. Specifically, this species evolved functional edentulism by evolutionary changes in the growth allometry of the dentition and by altering growth rates through ontogeny. This observation supports previous hypotheses that S. quadriscissus underwent ontogenetic tooth reduction. Tooth reduction in S. quadriscissus may be caused by unique selective pressures resulting from prey choice and feeding behavior, expanding our current understanding of the mechanisms producing tooth reduction.

Tooth shade measurements under standard and nonstandard illumination and their agreement with skin color.

PubMed

Al-Dwairi, Ziad; Shaweesh, Ashraf; Kamkarfar, Sohrab; Kamkarfar, Shahrzad; Borzabadi-Farahani, Ali; Lynch, Edward

2014-01-01

The purpose of this study was to examine the relationship between skin color (shade) and tooth shade under standard and nonstandard illumination sources. Four hundred Jordanian participants (200 males, 200 females, 20 to 50 years of age) were studied. Skin colors were assessed and categorized using the L'Oreal and Revlon foundation shade guides (light, medium, dark). The Vita Pan Classical Shade Guide (VPCSG; Vident) and digital Vita EasyShade Intraoral Dental Spectrophotometer (VESIDS; Vident) were used to select shades in the middle thirds of maxillary central incisors; tooth shades were classified into four categories (highest, high, medium, low). Significant gender differences were observed for skin colors (P = .000) and tooth shade guide systems (P = .001 and .050 for VPCSG and VESIDS, respectively). The observed agreement was 100% and 93% for skin and tooth shade guides, respectively. The corresponding kappa statistic values were 1.00 and 0.79, respectively (substantial agreement, P < .001). The observed agreement between skin color and tooth shades (VPCSG and VESIDS) was approximately 50%. The digital tooth shade guide system can be a satisfactory substitute for classical tooth shade guides and clinical shade matching. There was only moderate agreement between skin color and tooth shade.

Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel.

PubMed

Zhang, Zhihong; Wang, Xiaoyang; Tong, Jin; Stephen, Carr

2018-01-01

A highly efficient soil-burrowing dung beetle possesses an intricate outer contour curve on its foreleg end-tooth. This study was carried out based on evidence that this special outer contour curve has the potential of reducing soil penetration resistance and could enhance soil-burrowing efficiency. A toothed wheel is a typical agricultural implement for soil imprinting, to increase its working efficiency; the approach of the bionic geometrical structure was utilized to optimize the innovative shape of imprinting toothed wheel. Characteristics in the dung beetle's foreleg end-tooth were extracted and studied by the edge detection technique. Then, this special outer contour curve was modeled by a nine-order polynomial function and used for the innovative design of imprinting the tooth's cutting edge. Both the conventional and bionic teeth were manufactured, and traction tests in a soil bin were conducted. Taking required draft force and volume of imprinted microbasin as the evaluating indexes, operating efficiency and quality of different toothed wheels were compared and investigated. Results indicate that compared with the conventional toothed wheel, a bionic toothed wheel possesses a better forward resistance reduction property against soil and, meanwhile, can enhance the quality of soil imprinting by increasing the volume of the created micro-basin.

3D Simulation Modeling of the Tooth Wear Process.

PubMed

Dai, Ning; Hu, Jian; Liu, Hao

2015-01-01

Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

3D Simulation Modeling of the Tooth Wear Process

PubMed Central

Dai, Ning; Hu, Jian; Liu, Hao

2015-01-01

Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation. PMID:26241942

Consequences of tooth loss: 2. Dentist considerations--restorative problems and implications.

PubMed

Craddock, Helen L

2010-01-01

Partial tooth loss is much less well tolerated by patients than was previously the case and, on occasions, when extraction is inevitable, they may seek prosthetic replacement. This paper explores some of the consequences of tooth loss that may cause difficulties in tooth replacement, particularly if replacement is delayed for some time. An awareness of potential difficulties, particularly with posterior tooth replacement, will allow clinicians to make treatment decisions in the light of current evidence.

Detecting gear tooth fracture in a high contact ratio face gear mesh

NASA Technical Reports Server (NTRS)

Zakrajsek, James J.; Handschuh, Robert F.; Lewicki, David G.; Decker, Harry J.

1995-01-01

This paper summarized the results of a study in which three different vibration diagnostic methods were used to detect gear tooth fracture in a high contact ratio face gear mesh. The NASA spiral bevel gear fatigue test rig was used to produce unseeded fault, natural failures of four face gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face gears, vibration signals were monitored and recorded for gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. These methods use the signal average in both the time and frequency domain. Method NA4* was able to conclusively detect the gear tooth fractures in three out of the four fatigue tests, along with gear tooth surface pitting and heavy wear. For multiple tooth fractures, all of the methods gave a clear indication of the damage. It was also found that due to the high contact ratio of the face gear mesh, single tooth fractures did not significantly affect the vibration signal, making this type of failure difficult to detect.

Premolar and molar rotation in wild Japanese serow populations on Honshu Island, Japan.

PubMed

Natsume, Asuka; Koyasu, Kazuhiro; Oda, Sen-ichi; Nakagaki, Haruo; Hanamura, Hajime

2006-11-01

The skulls of 1195 Japanese serow (Capricornis crispus) from six geographically distinct populations were examined for tooth rotation. Our objectives were to determine tooth rotation patterns in Japanese serows, investigate geographical variation in tooth rotation and examine whether space limitations in the jaw accounted for variations. We then sought to explain the origin of tooth rotation in the Japanese serow. Rotated teeth were found in 131 specimens (62 males, 57 females and 12 unknown gender), with no statistically significant difference between males and females (chi(2)=0.03, P=0.86, d.f.=1). Among the six populations, the frequency of tooth rotation varied from 3.7-32.1% (average 11.0%). Most tooth rotation occurred in the upper third and fourth premolars. The lingual cusp of anomalous teeth was rotated 30 degrees -90 degrees mesially or distally from the buccolingual tooth axis, and the rotation direction differed among populations. However, we found no difference in skull or tooth morphology between normal individuals and those with tooth rotation. Therefore, hereditary factors may be involved in Japanese serow tooth rotation. We concluded that genetic differentiation occurred in the past among local Japanese serow populations isolated in mountainous habitats. Gene frequencies were likely subject to random drift, especially during possible population bottlenecks, when genetic factors could most strongly affect the direction of rotation.

A new digitized reverse correction method for hypoid gears based on a one-dimensional probe

NASA Astrophysics Data System (ADS)

Li, Tianxing; Li, Jubo; Deng, Xiaozhong; Yang, Jianjun; Li, Genggeng; Ma, Wensuo

2017-12-01

In order to improve the tooth surface geometric accuracy and transmission quality of hypoid gears, a new digitized reverse correction method is proposed based on the measurement data from a one-dimensional probe. The minimization of tooth surface geometrical deviations is realized from the perspective of mathematical analysis and reverse engineering. Combining the analysis of complex tooth surface generation principles and the measurement mechanism of one-dimensional probes, the mathematical relationship between the theoretical designed tooth surface, the actual machined tooth surface and the deviation tooth surface is established, the mapping relation between machine-tool settings and tooth surface deviations is derived, and the essential connection between the accurate calculation of tooth surface deviations and the reverse correction method of machine-tool settings is revealed. Furthermore, a reverse correction model of machine-tool settings is built, a reverse correction strategy is planned, and the minimization of tooth surface deviations is achieved by means of the method of numerical iterative reverse solution. On this basis, a digitized reverse correction system for hypoid gears is developed by the organic combination of numerical control generation, accurate measurement, computer numerical processing, and digitized correction. Finally, the correctness and practicability of the digitized reverse correction method are proved through a reverse correction experiment. The experimental results show that the tooth surface geometric deviations meet the engineering requirements after two trial cuts and one correction.

[Clinical evaluation of influence of aspirin on post-operative bleeding after tooth extraction in the elderly].

PubMed

Wang, Wen-ying; Cui, Nian-hui; Wang, En-bo; Zhang, Wei

2013-05-01

To investigate the feasibility of continuation of aspirin before tooth extraction in the elderly. The patients enrolled in this study were the elderly requiring a single non-impacted tooth extraction. 300 elderly outpatients used lidocaine local infiltration anesthesia, 200 patients without using aspirin before tooth extraction served as control group I, 100 patients with prolong use of aspirin before tooth extraction as observation group I. 300 elderly outpatients used compound articaine local infiltration anesthesia, 200 patients without using aspirin before tooth extraction served as control group II, 100 patients with prolong use of aspirin before tooth extraction as observation group II.Bleedings at 5, 10, 30 min, 24 h after tooth extraction were observed and the relationship between postoperative bleeding and intake of aspirin was analyzed. There was no significant difference at 5, 10, 30 min, 24 h in postoperative bleeding after extraction between control group I and observation group. The incidence of bleeding of observation group II after tooth extraction at 5 min was higher than that of control group II and there was no significant difference at 10, 30 min, 24 h between the two groups. Continuation of aspirin have no influence on postoperative bleeding. Therefore we suggest that there was no indication to discontinue aspirin for the elderly before a single non-impacted tooth extraction.

Formation of a successional dental lamina in the zebrafish (Danio rerio): support for a local control of replacement tooth initiation.

PubMed

Huysseune, Ann

2006-01-01

In order to test whether the formation of a replacement tooth bud in a continuously replacing dentition is linked to the functional state of the tooth predecessor, I examined the timing of development of replacement teeth with respect to their functional predecessors in the pharyngeal dentition of the zebrafish. Observations based on serial semithin sections of ten specimens, ranging in age from four week old juveniles to adults, indicate that (i) a replacement tooth germ develops at the distal end of an epithelial structure, called the successional dental lamina, budding off from the crypt epithelium surrounding the erupted part of a functional tooth; (ii) there appears to be a developmental link between the eruption of a tooth and the formation of a successional dental lamina and (iii) there can be a time difference between successional lamina formation and initiation of the new tooth germ, i.e., the successional dental lamina can remain quiescent for some time. The data suggest that the formation of a successional lamina and the differentiation of a replacement tooth germ from this lamina, are two distinct phases of a process and possibly under a different control. The strong spatio-temporal coincidence of eruption of a tooth and development of a successional dental lamina is seen as evidence for a local control over tooth replacement.

[Esthetic analysis on immediate single-tooth implant restoration in anterior maxilla].

PubMed

Li, Shao-wei; Wang, Guo-shi; Sha, Yan-zhi

2015-10-01

To evaluate the esthetic outcomes of immediate single-tooth implant restoration in anterior maxilla with the pink esthetic score (PES). Nine patients were treated with 9 Straumann implants by immediate single-tooth implant restoration in anterior maxilla. Assessment of PES after crown placement at 1 week (baseline) and 6 months after implantation was conducted. Statistical analysis was performed using SPSS 16.0 software package. Nine implants achieved a retention rate of 100%. PES for single-tooth implant was 10.33 ± 1.50 at 1 week and 11.44 ± 0.88 at 6 months after crown placement. The difference was significant(P=0.021). This study indicates that immediate single-tooth implant restoration in anterior maxilla is predictable. Immediate single-tooth implantation can result in good clinical esthetic results in most patients with single-tooth missing in anterior maxilla.

Deciduous tooth chronology in the mandible of the domestic pig.

PubMed

Bivin, W S; McClure, R C

1976-01-01

Fetuses of known age, collected from 20 days' gestation to term, were used to characterize the chronology of deciduous tooth development within the right mandible of swine. Tooth development was first observed at 32 days' embryonic development, with the differentiation of the deciduous third molar. Bud stages for the remaining deciduous teeth differentiated within the period of 32 to 38 days of embryonic development. Although the initial histological appearance of these teeth covered a short period of time, it was apparent that each tooth continued to develop at its own rate. The deciduous second incisor and first molar reached a stage of enamel formation by the 80th and 86th day of fetal development. This is a much later stage than previously recorded for beginning enamel formation. The stages of tooth development and enamel formation for each tooth are summarized. A previous report on the distribution of the dental lamina and deciduous tooth development in the mandible of the domestic pig combined with the information presented in this report on tooth chronology provide much of the information required for future studies using the domestic pig in dental research. A fetus observed at the 74th day of development demonstrated a tooth bud for the deciduous first premolar. The development of this tooth was followed closely throughout the remainder of fetal development with the cap stage representing its most definitive form at 110 days' development. The suggested deciduous origin for this tooth could result in a reevaluation of the nomenclature for the dental formula of swine.

Regenerative Endodontic Treatment with Orthodontic Treatment in a Tooth with Dens Evaginatus: A Case Report with a 4-year Follow-up.

PubMed

Natera, Marianella; Mukherjee, Padma M

2018-06-01

Dens evaginatus is a developmental tooth anomaly in which an extra cusp or tubercle protrudes on the occlusal surface of the tooth along with some pulpal tissue. Because of the fragile nature of the protrusion, these teeth are often at risk of pulpal exposure. When this occurs in an immature tooth, regenerative endodontic treatment may be a good treatment approach to promote root formation. There is limited literature that documents the occurrence of orthodontic treatment in teeth that have undergone regenerative endodontic therapy using triple antibiotic paste. Here we present a case of an immature premolar tooth with dens evaginatus that was diagnosed with pulp necrosis and chronic apical abscess. The tooth was treated with regenerative endodontic treatment; after which, the patient received orthodontic treatment with fixed appliances for 2 years. The tooth responded favorably to the regenerative endodontic treatment and orthodontic tooth movement. Clinically and radiographically, all the follow-up examinations revealed an asymptomatic tooth with evidence of periapical healing with stunted root development. The tooth remained asymptomatic even after 4 years. The regenerative endodontic procedure (REP) was successful in treating an immature permanent premolar with pulp necrosis and apical periodontitis with dens evaginatus. In this case, the tooth treated with an REP responded to orthodontic treatment similar to the nonendodontically treated teeth. Further studies are recommended to clarify the precise effects of orthodontic treatment on teeth treated with an REP. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.