A unique localization of mechanoreceptors in the periodontal tissue of guinea pig teeth

This study describes the unique distribution of Ruffini endings (RE) in the periodontal tissues of the guinea pig teeth with special references to their presence in the enamel-related aspects of the continuously growing incisors and molars. In guinea pig incisors, immunohistochemistry for PGP 9.5 and glia specific S-100 protein revealed a condensed distribution of well-developed RE in the bone-related part of the lingual periodontal ligament as has been reported in many other rodents. In most cases, some RE-like nerve elements characterized by dendritic ramification and rounded terminal Schwann cells were found to be located in the labial, enamel-related regions, where no periodontal ligament-like fiber arrangement was established. In the molar periodontal ligament, well-developed RE-like nerve elements were also distributed in the enamel-related part, but in intimate relation to thick periodontal fiber bundles inserted in the cementum pearls grown on the enamel surface. In some cases, few RE were located in the apical region of the alveolar socket, where no periodontal fiber bundles could be identified. Our data provide the first morphological evidence of the presence of RE-like nerve elements in the enamel-related, fibrous connective tissue of continuously erupting rodent incisors. These data indicate that RE in guinea pig periodontal tissues have variable spatial correlation to the surrounding fibers, implicating their diverse mechanoreceptive properties depending on the anatomical location.     

Dothideales

The type specimens or representative specimens of the potentially dothidealean genera Bagnisiella, Botryochora, Coccostromella, Columnosphaeria, Delphinella, Dictyodothis, Discosphaerina, Dothidea, Dothiora, Endodothiora, Jaffuela, Mycoporis, Omphalospora, Pachysacca, Plowrightia, Saccothecium, Stylodothis, Sydowia and Yoshinagaia were examined while, fresh specimens of Aureobasidium pullulans, Dothidea insculpta, Plowrightia ribesia and Saccothecium sepincola were made from Italy and Thailand. An introduction and the history of these genera, their family placement, morphology, and molecular phylogeny are provided. Morphology plus GenBank data are used to provide a systematic treatment of Dothideales. Phylogenetic analysis of LSU, SSU and ITS gene regions was carried out and in the resulting phylogenetic tree the taxa cluster in two clades with high bootstrap support. Clade A comprises Dothideaceae, the family type of Dothideales. The family Dothioraceae is not recognized as a distinct family and is synonymized under Dothideaceae. Neocylindroseptoria is introduced to accommodate Cylindroseptoria pistaciae as it forms a well-supported distinct clade in Dothideaceae. Clade B comprises Aureobasidium, Kabatiella, Pseudoseptoria, Saccothecium and Selenophoma species and Columnosphaeria fagi, for which we propose a new family, Aureobasidiaceae. The recently introduced Sydowia eucalypti also clustered within Clade B and therefore based on morphology and molecular phylogeny a new genus Pseudosydowia is introduced for Sydowia eucalypti. Celosporium laricicola is separated in a distinct clade, and therefore it is placed in Dothideales, genera, incertae sedis. The genera Bagnisiella, Botryochora, Coccostromella, Jaffuela, Lucidascocarpa, Mycoporis, Omphalospora, Pachysacca and Yoshinagaia are excluded from Dothideales and their placements are discussed.     

N-Linked Glycosylation on Anthrax Toxin Receptor 1 Is Essential for Seneca Valley Virus Infection

Seneca Valley virus (SVV) is a picornavirus with potency in selectively infecting and lysing cancerous cells. The cellular receptor for SVV mediating the selective tropism for tumors is anthrax toxin receptor 1 (ANTXR1), a type I transmembrane protein expressed in tumors. Similar to other mammalian receptors, ANTXR1 has been shown to harbor N-linked glycosylation sites in its extracellular vWA domain. However, the exact role of ANTXR1 glycosylation on SVV attachment and cellular entry was unknown. Here we show that N-linked glycosylation in the ANTXR1 vWA domain is necessary for SVV attachment and entry. In our study, tandem mass spectrometry analysis of recombinant ANTXR1-Fc revealed the presence of complex glycans at N166, N184 in the vWA domain, and N81 in the Fc domain. Symmetry-expanded cryo-EM reconstruction of SVV-ANTXR1-Fc further validated the presence of N166 and N184 in the vWA domain. Cell blocking, co-immunoprecipitation, and plaque formation assays confirmed that deglycosylation of ANTXR1 prevents SVV attachment and subsequent entry. Overall, our results identified N-glycosylation in ANTXR1 as a necessary post-translational modification for establishing stable interactions with SVV. We anticipate our findings will aid in selecting patients for future cancer therapeutics, where screening for both ANTXR1 and its glycosylation could lead to an improved outcome from SVV therapy.     

Cryo-EM Structure of a Possum Enterovirus

Enteroviruses (EVs) represent a substantial concern to global health. Here, we present the cryo-EM structure of a non-human enterovirus, EV-F4, isolated from the Australian brushtail possum to assess the structural diversity of these picornaviruses. The capsid structure, determined to ~3 Å resolution by single particle analysis, exhibits a largely smooth surface, similar to EV-F3 (formerly BEV-2). Although the cellular receptor is not known, the absence of charged residues on the outer surface of the canyon suggest a different receptor type than for EV-F3. Density for the pocket factor is clear, with the entrance to the pocket being smaller than for other enteroviruses.     

Distribution pattern of cholinesterase enzymes in human tooth germs

The two distinct molecular forms of cholinesterase (ChE) are acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Our previous studies have reported that ChE is involved in tooth development. However, further experiments are needed to understand the precise action of ChE in tooth development. This study aimed to localise types of ChE in human tooth germs, and identify their distribution pattern.ChE were localised in frozen sections of jaws which were prepared from dead fetuses, neonates and stillborns who were free from visible abnormalities by Karnovsky and Root method.AChE was identified in the inner and outer enamel epithelia including the cervical loop region, stratum intermedium and preameloblasts of tooth germs at bell stage. Secretory ameloblasts were free from staining. The bud and cap stages of permanent tooth germs showed AChE activity on the lingual aspect and top surface of the epithelial ingrowths, respectively. BuChE activity was localised in the degenerating dental lamina.Our study reported the first evidence of localisation of ChE in human tooth development and identified the possible molecular form of ChE in tooth germs as AChE. Also, our results have provided strong evidence to speculate the action of AChE is on the cells of enamel organ during tooth development.     

Synthesis of macromolecular antioxidants by reaction of aromatic amines with epoxidized polyisoprene, 3. Reaction of 4-anilinoaniline with epoxidized 1,4-polyisoprene

4-Anilinoaniline ( 6 ) reacts with expoxidized 1,4-polyisoprene in toluene under phenol catalysis. Secondary cyclization reactions are detected at longer reaction times (≧ 18 h). However, the kinetic results, obtained at the beginning of the reaction and for limited phenol concentrations, agree with a mechanism involving a trimolecular transition state and a concerted transfer.     

Prevention of dental caries in partially erupted permanent teeth with a CO2 laser

OBJECTIVE: The purpose of this study was to determine the effect of CO2 laser irradiation in the prevention of pit and fissure caries in immature molars with covering opercula. BACKGROUND DATA: In pediatric dentistry, it is not unusual to find partially erupted immature permanent teeth, especially with opercula. Conventional dental caries prevention is not effective in these cases because of the immaturity of tooth substance and the presence of the opercula, which accumulate a substantial amount of plaque. MATERIALS AND METHODS: The CO2 laser was used on 22 immature erupting molars with opercula. In each case, we first cut the operculum with a CO2 laser in a 2- or 3-watt continuous mode. Then, the occlusal surface was irradiated spot by spot along the pits and fissures of the molar using a CO2 laser in a 2-watt pulsed mode with 0.2 sec of irradiation time (average power, 0.3 watt; pulse width, 10 msec; repetition time, 15 Hz; energy density, 15 J/cm2). Each of the studied teeth was clinically examined for dental caries for 3 years. RESULTS: It took less than 2 min to cut the operculum, and there was no bleeding. The irradiation imparted acid resistance to the teeth without any discomfort to the patients. The patients did not complain of any pain after the procedure. Only two of the studied teeth developed dental caries during the observation period. CONCLUSION: We conclude that a CO2 laser might be an effective mode of treatment in the prevention of pit and fissure caries in partially erupted permanent molars covered with opercula.