The dredge gear is dragged along the bottom of the sea to catch targeted edible bottom dwelling species. Species composition and ecological index of the catches of dredge were estimated around Gangneung coastal fishing ground by dredge with different mesh size and tooth space from July to December 2013. Eight different types of dredge including four different tooth space (24.7 mm, 29.9 mm, 34.9 mm, 40.1 mm) and four different mesh size(15.5 mm, 32.7 mm, 51.1 mm, 060.0 mm) were used in the experiment. During the experiment, total catches were collected 31 species as sipunculida 1 species, mollusca 13 species, annelida 3 species, arthropoda 8 species, echinodermata 4 species and others 2 species. The dominant genus were mollusca and echinodermata while the dominant species were Megangulus venulosus, Pseudocardium sachalinensis, Schaphechinus brevis. The richness index was ranged 1.29-1.72, evenness index was 0.6-0.65 and diversity index was 1.65-1.83 according to the tooth space and mesh size of dredge. Richness index, diversity index were high at tooth space 34.9 mm dredge and ecological index showed decreasing tendency with the increasing of mesh size of dredge. Cluster and MDS analysis, based on a Bray-Curtis and similarity matrix of fourth root transformed data of number of species and wet weight, showed division into four different groups as four different tooth space (Group A), four different mesh size Group B (51.1 mm, 60.0 mm), Group C (32.7 mm) and Group D (15.5 mm).

LAR-RPTP (leukocyte common antigen-related receptor protein tyrosine phosphatase) is an important regulator in the nervous system, but little is known about its expression pattern in rat trigeminal ganglion (TG) neurons. To examine whether LAR-RPTP is expressed in the TG in the current study, we sacrificed rats at 0, 7, 10 and 56 day postpartum (dpp) and a second group of rats at 3 and 5 days after an experimental tooth extraction as a TG injury model. RT-PCR was then used to determine the level of LAR-RPTP expression in the TG and immunohistology was employed to detect the subcellular localization of the protein. The mRNA expression of LAR-RPTP during the developmental stages in the TG was found to gradually increase. After experimental tooth extraction however, these transcript levels had significantly decreased at three days. LAR-RPTP protein signals in the TG were found to be cytoplasmic in the normal animals but interestingly, at five days after an experimental tooth extraction, these signals were rare. These results indicate that LAR-RPTP may be regulated during both the developmental as well as regenerative processes that take place in the TG. This further suggests that LAR-RPTP is not only involved in primary axonogenesis but possibly also in the molecular control of axons during TG repair.

Hertwig's epithelial root sheath (HERS) consists of bilayered cells derived from the inner and outer dental epithelia and plays important roles in tooth root formation as well as in the maintenance and regeneration of periodontal tissues. With regards to the fate of HERS, and although previous reports have suggested that this entails the formation of epithelial rests of Malassez, apoptosis or an epithelialmesenchymal transformation (EMT), it is unclear what changes occur in the epithelial cells in this structure. This study examined whether HERS cells undergo EMT using a keratin-14 (K14) cre:ROSA 26 transgenic reporter mouse. The K14 transgene is expressed by many epithelial tissues, including the oral epithelium and the enamel organ. A distinct K14 expression pattern was found in the continuous HERS bi-layer and the epithelial diaphragm were visualized by detecting the β-galactosidase (lacZ) activity in 1 week postnatal mice. The 2 and 4 week old mice showed a fragmented HERS with cell aggregation along the root surface. However, some of the lacZ-positive dissociated cells along the root surface were not positive for pan-cytokeratin. These results suggest that the K14 transgene is a valuable marker of HERS. In addition, the current data suggest that some of the HERS cells may lose their epithelial properties after fragmentation and subsequently undergo EMT.

The notion that dental amalgam is a potential source of mercury exposure remains a controversial issue. However, there are few epidemiological analyses that have addressed whether this occurs in children. We aimed in our current study to identify the relationship between dental amalgam filling surfaces and the blood mercury levels in a cohort of 711 South Korean children aged between 8-9 years. Oral examinations were conducted to detect the number of amalgam filling surfaces on the teeth of these individuals. Blood samples were also taken from these children to assess the levels of mercury accumulation in the body. The amalgam filling surfaces were classified into four groups based on their number: 0 (n = 368), 1-5 (n = 219), 6-10 (n = 89), and 11+ (n = 35). The blood mercury levels in the children with more than 10 amalgam surfaces was 0.47 μg/L higher on average than those with no amalgam surfaces after adjusting for the frequency of fish or seafood consumption, age, and gender (P < 0.05). We found from our data that a higher number of dental amalgam fillings correlated with a higher blood mercury level in Korean children. Further studies are needed to investigate whether these elevated mercury levels exert neurotoxic or nephrotoxic effects.

Teeth develop via a reciprocal induction between the ectomesenchyme originating from the neural crest and the ectodermal epithelium. During complete formation of the tooth morphology and structure, many cells proliferate, differentiate, and can be replaced with other structures. Apoptosis is a type of genetically-controlled cell death and a biological process arising at the cellular level during development. To determine if apoptosis is an effective mechanism for eliminating cells during tooth development, this process was examined in the rat mandible including the developing molar teeth using the transferase-mediated dUTP-biotin nick labeling (TUNEL) method. The tooth germ of the mandibular first molar in the postnatal rat showed a variety of morphological appearances from the bell stage to the crown stage. Strong TUNEL-positive reactivity was observed in the ameloblasts and cells of the stellate reticulum. Odontoblasts near the prospective cusp area also showed a TUNEL positive reaction and several cells in the dental papilla, which are the forming pulp, were also stained intensively in this assay. Our results thus show that apoptosis may take place not only in epithelial-derived dental organs but also in the mesenchyme-derived dental papilla. Hence, apoptosis may be an essential biological process in tooth development.

Cholinesterase (ChE) is one of the most ubiquitous enzymes and in addition to its well characterized catalytic function, the morphogenetic involvement of ChE has also been demonstrated in neuronal tissues and in non-neuronal tissues such as bone and cartilage. We have previously reported that during mouse tooth development, acetylcholinesterase (AChE) activity is dynamically localized in the dental epithelium and its derivatives whereas butyrylcholinesterase (BuChE) activity is localized in the dental follicles. To test the functional conservation of ChE in tooth morphogenesis among different species, we performed cholinesterase histochemistry following the use of specific inhibitors of developing molar and incisors in the hamster from embryonic day 11 (E11) to postnatal day 1 (P1). In the developing molar in hamster, the localization of ChE activity was found to be very similar to that of the mouse. At the bud stage, no ChE activity was found in the tooth buds, but was first detectable in the dental epithelium and dental follicles at the cap and bell stages. AChE activity was found to be principally localized in the dental epithelium whereas BuChE activity was observed in the dental follicle. In contrast to the ChE activity in the molars, BuChE activity was specifically observed in the secretory ameloblasts of the incisors, whilst no AChE activity was found in the dental epithelium of incisors. The subtype and localization of ChE activity in the dental epithelium of the incisor thus differed from those of the molar in hamster. In addition, these patterns also differed from the ChE activity in the mouse incisor. These results strongly suggest that ChE may play roles in the differentiation of the dental epithelium and dental follicle in hamster, and that morphogenetic subtypes of ChE may be variable among species and tooth types.

Two male reticulated giraffes (Giraffa camelopardalis reticulata), 21-year-old, died of nutritional deficiency that primarily caused by serious tooth wear at Seoul Zoo in winter. A 970 kg-weighed giraffe showed tooth wear of premolars, molars and incisors at necropsy. A foreign body in the rumen, congestion and ulcer of abomasum and duodenum were also observed. Mild appearance of serous fat atrophy in pericardial sac suggests that lack of nutritional intake caused by tooth wear can become harmful enough to threat life. At the necropsy of a 1,290 kg-weighed giraffe, a large quantity of sandy soil were found in the rumen which would stuck the pathway of well-fermented ruminal contents at esophageal groove. Nutritional deficiency could be suspected to urge this giraffe to graze grass on the ground along with sandy soil. Secondarily, the soil damaged teeth and become a culprit making irregular tooth wear and mild serous fat atrophy. Nutritionally good care of geriatric animals is needed especially for browsing animals like giraffes and critically in winter season.

Krox-25, a Kruppel type zinc finger protein, may play an important role for the morphogenesis of tooth in ectomesenchymal interaction between enamel epithelium and odontogenic mesenchyme. The interrupted expression of Krox-25 by antisense inhibition is supposed to affect the abnormal development of tooth germ similar to the deranged proliferation of odontogenic tumors. This study was performed to know the histomorphogenetic effect of Krox-25 antisense inhibition in tooth germs of mouse embryos and to understand the abnormal expressions of Krox-25 in different odontogenic tumors which proliferate in aberrant direction of ecto-mesenchymal interaction. Total 95 tooth germs obtained from pregnant mice in the 13th day of fertilization were cultured with antisense oligonucleotides targeting mouse Krox-25 gene, and their histological patterns were compared with those of different odontogenic tumors, i.e., ameloblastic fibro-odontoma (n=5), ameloblastoma (n=8), and ameloblastic carcinoma (n=2). Resultantly, the cultured tooth germs treated with antisense oligodeoxynucleotides produced primitive dentine and enamel by odontoblasts and ameloblasts, respectively, but they aberrantly grew and formed abnormal tooth organs. Especially, the harmonious growth of enamel and dentine formation was greatly deranged by the antisense inhibition in the organ culture system. These findings were much similar to the abnormal growth of odontogenic tumors. The relatively well differentiated enamel epithelium of ameloblastic fibro-odontoma showed irregularly strong reaction of Krox-25, while the poorly differentiated enamel epithelium of ameloblastic carcinoma showed weak reaction. These data suggest that Krox-25 may play important roles for the histomorphogenesis of tooth germ by signaling the ecto-mesenchymal interaction between odontoblasts and ameloblasts in normal tooth germ development of mouse embryos as well as in cytodifferentiation of odontogenic tumors.

This study was carried out to find out the effect of establishment or renovation of organic pasture by hoof and tooth cultivation with Korean native goat. This study was conducted from August, 2005 to the end of growing season in 2008 at test field of RDA in Cheonan. Experiment design composed with 4 treatment : Standard(Control, T1), Grazing after application cattle manure(T2), Application cattle manure after grazing(T3), Application cattle manure at half of grazing(T4).

The purpose of this study is to investigate the relationship of periodontal disease to self-reported history of stroke in the elderly(60 years of age and older) with a special emphasis on elderly women. Data from the Third National Health and Nutrition Examination Survey(NHANES III), a large population-based cross-sectional survey of the United States, were utilized for this study. Since we have 1,563 edentulous subjects from a total of 5,123 subjects and periodontal disease is a major cause of tooth loss, it was necessary to account for this in our statistical analysis. Hence, we developed a new index called the Periodontal Health Status(PHS) index. In the logistic regression models with stratification by gender, males did not show statistically significant relationship between Periodontal Health Status(PHS) and stroke history. In contrast, females showed some marginal association between Periodontal Health Status(PHS) and stroke history. Further longitudinal intervention studies need to be conducted to determine the temporal relationship between periodontal disease and stroke

We developed a new tooth profile designed for P/M internal gear pump rotors. The theoretical discharge volume of the new tooth profile internal gear rotors is more than 10% higher than that of the same size conventional rotors. Our new profile rotors can achieve a decrease in torque, and fuel-efficiency will also be improved.

rt is well known that glycosaminoglycans are 01' fllndamental importance to the processes 01' morphogenesis and cytodifferentiati on dllring the teeth development , With HlD-TCH-SP(High - iron diamine-thiocarbohydrazide-silvel protcinntc) , s lllfatcd glycosaminoglycans such as chondroitin sulfate and heparan slllfate have been localized a t the III trastrllctural level i n a wide variety of tlssues The pmpose of this stlldy were to examine slllfated glycosaminoglycan at llltrastrllctllral level fo 1' the phase of morphogenesis and cytodifferentiation of hllma n fetal tooth germs, and to detect the protein expression of slllfated glycosaminoglycan by immunoslot blot Human tooth gerll1s fl'Oll1 the a lveolar bone of twenty still born fetuses we1'e fixed in a mixtllre of 2% gllltaraldehyde/1% forma ldehyde, The 미 t 1'athin sections were stained witb HID-TCH-SP and were treated with 0, 05% solution of t esticular hyaluronidase to identify the histochemical properties 01' tbe HID-TCH-SP stain deposits , For semi quantitative protein assay , immllnoslot blot was done Sulfated glycocongugated deposits were localized in DEJ, peri tubular dentin , and mantle dentin matrix‘ enamel prism sheath , interrod area , and enamel matnx Heparan sll l띠 te deposits i n DEJ resisted to testicular hyalllronidase treatment prior to HID-TCH-SP staining, Immunoslot blot s howed that• chondroitin sulfate was detected higher in enamel and dentin extract, while heparan sulfate was relatively expressed in enamel and dentin extract, but rarely expressed in enamel or dentin extract It suggest ecl that chonclroi tin and hepa ran slllfate woulcl play an important role in the formation of DEJ, while chondroitin sulfate would in the clevelopll1ent of enamel prism sheath, enamel matrix, and mantle 01' peritublllar clentin of human fetal tooth germs,

It is well known that glycoproteins, glycosaminoglycans and proteoglycans are of fllndamental importance to the processes of morphogenesis and cytodifferentiation dllring the teeth development. With HID-TCH-SP(High-iron diamine-thiocarbohydrazide-silver proteinate), slllfated glycosaminoglycans sllch as chondroitin slllfate and heparan slllfate have been localized at the 1I1trastructurallevel in a wide variety of tisslles. 까le pllrpose of this study were to characterize slllfated glycosaminoglycan profiles of hllman fetal tooth genns at 비trastructurallevel for the phase of morphogenesis and cytodifferentiation, and to detect the protein expression of sulfated glycosaminoglycan by immunoslot blot. Human tooth germs from the alveolar bone of twenty still born fetuses were f1xed in a mixture of 2% glutaraldehyde/ l% fonnaldehyde. The ultrathin sections were stained with HIDTCH- SP, and some sections were σ'eated with 0.05% solution of testicular hyaluronidase to identify the histochemical properties of the HID-TCH-SP stain deposits. For semiquantitative protein assay, immunoslot blot was done. The obtained results were as follows 1. HID-TCH-SP staining showed sulfated glycocongugated deposits in DEJ, peritublllar dentin, and mantle dentin matrix, enamel prism sheath, interrod area, and enamel matrix. 2. Heparan sulfate deposits in DEJ resisted to testicular hyalllronidase treatment prior to HID-TCH-SP staining 3. In immunoslot blot, chondroitin slllfate was detected higher in enamel and dentin extraα ， while heparan slllfate was relatively expressed in enamel and dentin extract, but rarely expressed in enamel or dentin extract. From the aboving results, it was suggested that chondroitin and heparan sulfate would play an important role in the formation of D티， while chondroitin sulfate would in the development of enamel prism sheath, enamel matrix, and mantle or peritllblllar dentin of human fetal t∞th germs.

Worldwide consumption of vegetable soybean bas been increasing recently, hence it is necessary to produce good quality of soybean in our farms. In the process of vegetable soybean production threshing and seperation work accounts for about 80% of overall labor. Therefore, developing of the vegetable soybean thresher is necessary to reduce the cost of labor. The purpose of this study is to acquire the basic informations to design of the vegetable soybeans-thresher. We make the experimental system which measure the physical properties and investigate the detachment forces. Also, We calculated the minimum speed of threshing cylinder. The result are as follows; 1. The average length of soybean stem is 68.2cm. 2. The length of soybean pods are seen as 61.3mm for 3 grain, 52.6mm fer 2 grains and 41.0mm fer 1 grain 3. The widths of soybean pods are seen as 14.1mm fer 3 grain, 13.8mm fer 2 grains and 13.4mm fer 1 grain. 4. The weights of soybean pods are seen as 4.1grams for 3 grains, 2.7grams for 2 grains and 1.4grams for 1 grain. 5. The average detachment forces of pods are seen as 1.5kgf for 3 grains, 1.2kgf for 2 grains and 0.8kgf for 1 grain respectively For 1 grain, the detachment force of pods ranges from 0.2kgf to 1.4kgf. For 2 grains, the minimum detachment force of pods is seen as 0.6kgf and the maximum one is seen as 2.5kgf. For 3 grains, the minimum detachment force of pods is seen as 0.7kgf and the maximum one is seen as 2.7kgf. 6. The minimum speed of threshing cylinder is shown 6.83m/s.