Occupational hazards among dental hygienists: Risk level assessment of scaling work.

OBJECTIVES: This study aimed to classify occupational hazards of ultrasonic scaling by factor and to identify the distribution of occupational risk levels of the study participants according to occupational hazards. In addition, the relationship between the general characteristics of dental hygienists and the occupational risk level of scaling was investigated. METHODS: This study was conducted on 237 dental hygienists. Exposure frequency and the degree of work loss were investigated on a five-point scale for each of the 15 occupational hazards of scaling. RESULTS: Among occupational hazards, the proportion of high-risk individuals for biological hazards (32.9%) was the highest. Dental clinics (33.6%) were found to have a higher proportion of high-risk individuals than dental hospitals (16.5%) (p < 0.05). The proportion of high-risk individuals was higher in the absence of an infection control coordinator (33.9%) (p < 0.05) and infection control education in the preceding 2 years (28.6%) (p < 0.05). CONCLUSION: To create a safe dental work environment, appropriate measures according to the risk level and measurement of occupational risk should be discussed.

Effect of self-learning media based on 360° virtual reality for learning periodontal instrument skills.

INTRODUCTION: Of 360° Virtual Reality (VR) is possibly produced and sufficiently effective as a consumer-friendly VR learning medium. Therefore, it is also expected to be useful in the dental practice field, as a self-learning medium for non-face-to-face skill training during the ongoing pandemic (COVID-19). Accordingly, this study was conducted to assess 360° VR self-learning media for a periodontal instrument operation. MATERIALS AND METHODS: We recruited 30 participants who had never experienced instrument training. We offered basic education and initial assessment (IA), then divided them into three groups: 1) PAPER: trained only with paper handouts; 2) 2D: trained with 2D video; 3) VR: trained with 360° VR. Each group performed self-learning and mid-term assessment (MA). Subjects then implemented home self-learning with the same media for one week, which was then followed by a final assessment (FA). RESULT: Analysis of IA-to-FA improvement scores showed that VR and 2D video were significantly higher than the PAPER groups. Meanwhile, analysis of MA-to-FA improvement scores showed that only VR was substantially higher than the PAPER group. Although VR and 2D video groups were not considerably different, VR scores were numerically higher than 2D video in all improvement score analyses. DISCUSSION: Both 2D video and 360° VR training were helpful to participants for an effective self-learning and also had good portability and accessibility as online-based learning methods. 360° VR showed higher learning efficiency than regular 2D video, possibly due to its autonomy, 360° visual information and physical and immersive characteristics, which positively affected self-training. CONCLUSION: Our findings showed the potential of 360° VR learning media and, further, suggest its usefulness as a novel self-learning method in future dental education.

GENETIC ANALYSIS OF ANCIENT CLONORCHIS SINENSIS EGGS ATTAINED FROM GORYEONG MUMMY OF JOSEON DYNASTY PERIOD.

Although Clonorchis sinensis is a parasite that still infects many people in East Asia, its genetics remain largely unknown. We conducted ancient DNA analysis of C. sinensis eggs obtained from a Joseon period mummy newly discovered in South Korea. Clonorchis sinensis DNA was amplified for internal transcribed spacer 1, cytochrome c oxidase subunit 1, and NADH dehydrogenase subunit 2 and 5 genes. The results of BLAST/NCBI showed that the consensus sequences were 98.24 to 100% identical to the modern and ancient C. sinensis sequences reported from Korea, China, Japan, and other Asian countries. Our report helps to fill in the genetic profile of ancient C. sinensis strains that infected East Asian people hundreds of years ago.

Two Helminthic Cases of Human Mummy Remains from Joseon-Period Graves in Korea.

Our previous research on coprolite specimens from the mummies of Joseon Dynasty (1392-1910 CE) has revealed various species of parasite eggs. Herein, we added 2 new helminthic cases of human remains from Joseon-period graves in the Republic of Korea (Korea). The organic materials precipitated on the hip bones of 2 half-mummied cases (Goryeong and Gwangmyeong cases) were collected, rehydrated, and examined by a microscope. In the sample from Goryeong-gun (gun=County), ova of Trichuris trichiura, Clonorchis sinensis, and Metagonimus spp. were detected, and eggs of T. trichiura and A. lumbricoides were found from the sample of Gwangmyeong-si (si=City). By adding this outcome to the existing data pool, we confirm our previous estimates of Joseon-period parasite infection rates. The overall rates of A. lumbricoides, T. trichiura, and C. sinensis decreased dramatically from Joseon to the modern period. In Goryeong mummy specimen, we also found Metagonimus spp. eggs that has rarely been detected in archaeological samples so far.

Effect of rosmarinic acid on differentiation and mineralization of MC3T3-E1 osteoblastic cells on titanium surface.

Titanium (Ti) is a widely used biomaterial for dental implants because of its outstanding biocompatibility for hard tissues. Osseointegration, the interaction between implanted biomaterials and living cells in bone, is essential for successful implantation. Rosmarinic acid (RA) is a plant-derived phytochemical with low toxicity and side effects and has various effects that can be applied as a therapeutic substance. The MC3T3-E1 osteoblastic cells on the Ti surface in medium with or without 14 µg/ml RA were used to test RA effects on osteoblast differentiation, cell viability and mineralization during differentiation. RA treatment increased osteoblast differentiation, cell viability and mineralization in MC3T3-E1 osteoblastic cells on Ti surface during differentiation, upregulating Runx-2 and OPG, but downregulating RANKL. This study suggest that RA should be applied as an effective functional and therapeutic substance to enhance osseointegration of osteoblast cells by increasing differentiation, mineralization, and bone formation through the RANKL/RANK/OPG pathway during the differentiation in MC3T3-E1 osteoblastic cells on the Ti surface.

Medieval mummies of Zeleny Yar burial ground in the Arctic Zone of Western Siberia.

Notwithstanding the pioneering achievements of studies on arctic mummies in Siberia, there are insufficient data for any comprehensive understanding of the bio-cultural details of medieval people living in the region. In the Western Siberian arctic, permafrost mummies have been found in 12th to 13th century graves located in the Zeleny Yar (Z-Y) burial ground (66°19'4.54"С; 67°21'13.54"В). In 2013-2016, we were fortunate to be able to excavate that cemetery, locating a total of 47 burials, including cases of mummification. Some of these mummies had been wrapped in a multi-layered birch-bark cocoon. After removal of the cocoon, we conducted interdisciplinary studies using various scientific techniques. Gross anatomical examination and CT radiography showed that the internal organs were still well preserved inside the body cavities. Under light and electron microscopy, the histological findings were very similar to those for naturally mummified specimens discovered in other countries. Ancient DNA analysis showed that the Z-Y mummies' mtDNA haplotypes belong to five different haplogroups, namely U5a (#34), H3ao (#53), D (#67-1), U4b1b1 (#67-2), and D4j8 (#68), which distinguish them for their unique combination of Western- and Eastern Siberia-specific mtDNA haplogroups. Our interdisciplinary study obtained fundamental information that will form the foundation of successful future investigations on medieval mummies found in the Western Siberian arctic.

Thymosin ß4 is associated with bone sialoprotein expression via ERK and Smad3 signaling pathways in MDPC-23 odontoblastic cells.

Thymosin ß4 (Tß4) regulates the expression of molecules associated with dentinogenesis, including bone sialoprotein (BSP). BSP regulates the initiation of mineralization and the direction of dentin growth. However, the association between Tß4 signaling and BSP expression in odontoblasts remains unclear. Therefore, the aim of the present study was to investigate Tß4 mRNA expression in odontoblasts during dentinogenesis and the association between the Tß4 signaling pathway and BSP expression in MDPC­23 odontoblastic cells. Expression and localization of Tß4 mRNA was determined by in situ hybridization during mouse tooth development. The effect of Tß4 signaling on BSP expression was investigated by reverse transcription polymerase chain reaction, western blot analysis, immunofluorescence and a luciferase reporter assay in the presence or absence of specific inhibitors of mitogen activated protein kinase kinase (PD98059) and mothers against decapentaplegic homolog 3 (Smad3; SIS3) in MDPC­23 cells. The expression of Tß4 mRNA in the odontoblast layer was highest at postnatal day 5, known as the advanced bell stage, when odontoblasts actively secrete dentin matrix proteins. Tß4 increased BSP mRNA and protein levels in MDPC­23 cells, but this was inhibited by PD98059 or SIS3 treatment. Tß4 increased levels of phosphorylated (p) extracellular signal­regulated kinase (ERK)1/2, pSmad3, pß­catenin, and runt­related transcription factor 2 (Runx2) protein, but these effects were inhibited by PD98059 or SIS3. Tß4 induced the nuclear translocation of Runx2 and pSmad3, while nuclear translocation of ß­catenin was decreased. Tß4 significantly increased BSP promoter activity, which was decreased by PD98059 or SIS3 treatment. Tß4 induced BSP expression in MDPC­23 cells via ERK and Smad3 signaling pathways, suggesting its role as a signaling molecule in odontoblasts for regulating BSP secretion during dentinogenesis.

Thymosin ß4 Reduces H2O2 Induced Oxidative Stress in MC3T3-E1 Cells on Titanium Surface.

Thymosin ß4 (Tß4) is known to inhibit an inflammatory response and to increase the survival of osteoblasts on titanium (Ti) surfaces. Ti is the most widely used graft material in dentistry; however, an inflammatory response induced following implant placement results in the generation of reactive oxygen species (ROS). The oxidative stress from the production of ROS such as nitric oxide (NO) and hydrogen peroxide (H2O2) can damage surrounding cells, resulting in implant failure by decreasing cell viability. Thus, the aim of this study was to determine the biological effects of Tß4 on the oxidative stress induced to MC3T3-E1 preosteoblasts on the Ti surface. Based on an MTT assay and bromodeoxyuridine immunofluorescence staining, Tß4 was found to increase the proliferation of the H2O2-exposed MC3T3-E1 cells on Ti discs. Reverse transcription-polymerase chain reaction and western blot analyses showed that Tß4 decreased the mRNA and protein expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in H2O2-exposed MC3T3-E1 cells on the Ti discs. Tß4 inhibited the synthesis of intracellular ROS and the secretion of NO and prostaglandin E2 (PGE2) from H2O2-exposed MC3T3-E1 cells on the Ti discs. In conclusion, Tß4 inhibits H2O2-induced iNOS and COX-2 expression with a decrease in ROS, NO, and PGE2 synthesis, which leads to improved cell survival with low cytotoxicity under an oxidative stress condition in MC3T3-E1 cells on the Ti surface. This suggests that Tß4 may be a crucial molecule to reduce oxidative stress-induced cell damage or hypoxia, leading to promoted osseointegration on the Ti surface during implant placement.

Association Between Chewing Difficulty and Symptoms of Depression in Adults: Results from the Korea National Health and Nutrition Examination Survey.

OBJECTIVES: To assess the association between chewing difficulty and symptoms of depression in a representative sample of the Korean population. DESIGN: Cross-sectional. SETTING: Korea National Health and Nutrition Examination Survey (KNHANES). PARTICIPANTS: KNHANES participants (N = 5,158). MEASUREMENTS: Chewing difficulty was assessed according to the self-reported presence of chewing problems using a structured questionnaire. Symptoms of depression were defined as having feelings of sadness or depression consecutively over 2 weeks during the last 12 months. Multivariable logistic regression analysis was used to determine the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of the associations between chewing difficulty and symptoms of depression, adjusted for age; sex; monthly household income; education; number of teeth; number of decayed, missing, or filled permanent teeth; periodontitis; state of dentition; tooth brushing frequency; regular dental visits; smoking status; alcohol consumption; hypertension; diabetes mellitus; and obesity. The interaction effects between chewing difficulty and confounders were evaluated, and age- and sex-stratified analyses were performed. RESULTS: There was a significant positive association between chewing difficulty and symptoms of depression in the fully adjusted model (AOR = 1.86, 95% CI = 1.48-2.33). The strength of the association was highest in men aged 60 and older (AOR = 3.28, 95% CI = 1.54-7.00). CONCLUSION: Chewing difficulty was independently associated with symptoms of depression in a representative sample of Korean adults.

Identification of proteins from 4200-year-old skin and muscle tissue biopsies from ancient Egyptian mummies of the first intermediate period shows evidence of acute inflammation and severe immune response.

We performed proteomics analysis on four skin and one muscle tissue samples taken from three ancient Egyptian mummies of the first intermediate period, approximately 4200 years old. The mummies were first dated by radiocarbon dating of the accompany-\break ing textiles, and morphologically examined by scanning electron microscopy of additional skin samples. Proteins were extracted, separated on SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) gels, and in-gel digested with trypsin. The resulting peptides were analysed using nanoflow high-performance liquid chromatography-mass spectrometry. We identified a total of 230 unique proteins from the five samples, which consisted of 132 unique protein identifications. We found a large number of collagens, which was confirmed by our microscopy data, and is in agreement with previous studies showing that collagens are very long-lived. As expected, we also found a large number of keratins. We identified numerous proteins that provide evidence of activation of the innate immunity system in two of the mummies, one of which also contained proteins indicating severe tissue inflammation, possibly indicative of an infection that we can speculate may have been related to the cause of death.This article is part of the themed issue 'Quantitative mass spectrometry'.

Secretory leukocyte protease inhibitor promotes differentiation and mineralization of MC3T3-E1 preosteoblasts on a titanium surface.

Mineralized bone matrix constituted with collagenous and non-collagenous proteins was synthesized by osteoblasts differentiated from mesenchymal stem cells. Secretory leukocyte protease inhibitor (SLPI), a serine protease inhibitor, promotes cell migration and proliferation, and suppresses the inflammatory response. Recent studies reported that SLPI regulates the formation of dentin and mineralization by odontoblasts and increases the adhesion and viability of preosteoblasts on a titanium (Ti) surface. Ti and its alloys are widely used implant materials in artificial joints and dental implants owing to their biocompatibility with bone. Therefore, this study aimed to examine whether SLPI can be an effective molecule in promoting differentiation and mineralization of osteoblasts on a Ti surface. In order to investigate the effects of SLPI on osteoblasts, an MTT assay, PCR, western blotting and Alizarin Red S staining were performed. The results demonstrated that SLPI increased the viability of osteoblasts during differentiation on Ti discs compared with that of the control. The expression levels of SLPI mRNA and protein were higher than that of the control after treatment of osteoblasts with SLPI on Ti discs during differentiation. SLPI increased the formation of mineralized nodules and mRNA expression of alkaline phosphatase, dentin sialophosphoprotein, dentin matrix protein 1, bone sialoprotein, and collagen I in osteoblasts on Ti discs compared with that of the control. In conclusion, SLPI increases the viability and promotes the differentiation and mineralization of osteoblasts on Ti surfaces, suggesting that SLPI is an effective molecule for achieving successful osseointegration between osteoblasts and a Ti surface.

The Effect of Thymosin ß4 for Osteoblast Adhesion on Titanium Surface.

Titanium (Ti) is the most widely used implant material in dentistry and orthopedics but the release of metal ions from Ti implants results in increased bone resorption by enhancing the production of inflammatory cytokines from the macrophages and facilitating osteoclast differentiation. Thymosin ß4 (Tß4) has several biological activities, such as promoting wound healing, angiogenesis, cell proliferation and migration in mammalian cells. This study examined the role of Tß4 in osteoblasts via focal adhesions (FAs) and ERK1/2 signaling related to cell adhesion and proliferation for cell survival on the Ti surface. As a result, cell adhesion and proliferation increased in the Tß4 treated cells (Tß4/MC3T3-E1) but was significantly lower in the Tß4 knock-down cells by Tß4-siRNA (si-Tß4/MC3T3-E1) than that of the untreated cells. The levels of FAK phosphorylation, paxillin expression, and paxillin localization were higher in the Tß4/IMC3T3-E1 cells than that of the untreated cells but lower in the si-Tß4/MC3T3-E1 cells. In addition, the levels of cell proliferation, Grb2 and Ras protein expression and phosphorylation of ERK1/2 were higher in the Tß4/MC3T3-E1 cells than in the untreated cells but lower in the si-Tß4/IMC3T3-E1 cells. These results suggest that Tß4 might be a good nanomolecule that promotes osteoblast survival by facilitating adhesion and proliferation on the Ti surface.

Diastolic Dysfunction Induced by a High-Fat Diet Is Associated with Mitochondrial Abnormality and Adenosine Triphosphate Levels in Rats.

BACKGROUND: Obesity is well-known as a risk factor for heart failure, including diastolic dysfunction. However, this mechanism in high-fat diet (HFD)-induced obese rats remain controversial. The purpose of this study was to investigate whether cardiac dysfunction develops when rats are fed with a HFD for 10 weeks; additionally, we sought to investigate the association between mitochondrial abnormalities, adenosine triphosphate (ATP) levels and cardiac dysfunction. METHODS: We examined myocardia in Wistar rats after 10 weeks of HFD (45 kcal% fat, n=6) or standard diet (SD, n=6). Echocardiography, histomorphologic analysis, and electron microscopy were performed. The expression levels of mitochondrial oxidative phosphorylation (OXPHOS) subunit genes, peroxisome-proliferator-activated receptor γ co-activator-1α (PGC1α) and anti-oxidant enzymes were assessed. Markers of oxidative stress damage, mitochondrial DNA copy number and myocardial ATP level were also examined. RESULTS: After 10 weeks, the body weight of the HFD group (349.6±22.7 g) was significantly higher than that of the SD group (286.8±14.9 g), and the perigonadal and epicardial fat weights of the HFD group were significantly higher than that of the SD group. Histomorphologic and electron microscopic images were similar between the two groups. However, in the myocardium of the HFD group, the expression levels of OXPHOS subunit NDUFB5 in complex I and PGC1α, and the mitochondrial DNA copy number were decreased and the oxidative stress damage marker 8-hydroxydeoxyguanosine was increased, accompanied by reduced ATP levels. CONCLUSION: Diastolic dysfunction was accompanied by the mitochondrial abnormality and reduced ATP levels in the myocardium of 10 weeks-HFD-induced rats.

Sulfasalazine induces autophagic cell death in oral cancer cells via Akt and ERK pathways.

Sulfasalazine (SSZ) is an anti-inflammatory drug that has been used to treat inflammatory bowel disease and rheumatoid arthritis for decades. Recently, some reports have suggested that SSZ also has anti-cancer properties against human tumors. However, little is known about the effects of SSZ on oral cancer. The aim of this study was to investigate the anti-cancer effects of SSZ in oral squamous cell carcinoma (OSCC) cells and to elucidate the mechanisms involved. The authors investigated the anti-proliferative effect of SSZ using the MTT method in HSC-4 cells (an OSCC cell line). Cell cycle analysis, acidic vesicular organelle (AVO) staining, monodansylcadaverine (MDC) staining and Western blotting were also conducted to investigate the cytotoxic mechanism of SSZ. SSZ significantly inhibited the proliferation of HSC-4 cells in a dose-dependent manner. In addition, SSZ induced autophagic cell death, increased microtubule-associated protein 1 light chain (MAP1- LC; also known as LC) 3-II levels, as well as induced punctate AVO and MDC staining, resulted in autophagic cell death. Furthermore, these observations were accompanied by the inhibition of the Akt pathway and the activation of ERK pathway. These results suggest that SSZ promotes autophagic cell death via Akt and ERK pathways and has chemotherapeutic potential for the treatment of oral cancer.

Amplification of DNA remnants in mummified human brains from medieval Joseon tombs of Korea.

Recently, a number of mummified brains obtained from the remains of medieval Joseon Koreans have been subjected to biological investigations. Although the morphology of the organs had been perfectly maintained on gross examination, we still do not know how well biomolecules such as DNA were preserved. In the present study, the preservation status of remnant DNA in mummified brain tissue was determined by means of comparisons with corresponding DNA taken from the femurs of the same subjects. Quantifiler analysis revealed that DNA from the mummified brain was less fragmented than that contained in the femurs. The better preservation status of the brain DNA was shown also in MiniFiler assays: the number of short tandem repeat (STR) locus profiles for the mummified brain was far higher than in the case of the femur bones. In the case of the mtDNA analysis, longer DNA fragments (821 bp) could be successfully amplified with brain samples, whereas only shorter PCR amplicons (221-263 bp) were seen with the femur samples. Indeed mummified brain tissue, if discovered in amounts suitable for ancient DNA analysis, promises to be the preferred source for genetic analysis of individuals from pre-modern Korean tombs.

Dynamin II involves in cell migration and actin formation of NIH3T3 cells.

It was previously reported that in Ras transformed NIH3T3 cells, dynamin II acts as an intermediate messenger in the Ras signal transduction pathway leading to membrane ruffling and cell migration. However, these results do not provide sufficient evidence of a relationship between dynamin II and the Ras signal transduction pathway leading to membrane ruffling and cell migration. The results showed that a dynamin II association with myosin II as a signaling molecule is involved in NIH3T3 cell migration through the Ras/PI3K signaling pathway, and is associated with the p85 subunit of PI3K. Confocal microscopy also revealed co-localization between dynamin II and paxillin after PDGF stimulation. In addition, immunofluorescence results showed that dynamin II was colocalized with the actin filament. After stimulating the NIH3T3 cells with PDGF and treating them with an actin inhibitor, such as Cytochalasin D, it was observed that dynamin II with the myosin II complex inhibited binding to the actin. Therefore, dynamin II is localized in focal adhesion when cell migration is triggered and binds to the actin filament component, suggesting that it is a good candidate nanomolecule to regulate the cell attachment and migration to the materials such as implants etc.

Expression of thymosin ß4 in odontoblasts during mouse tooth development.

Thymosin ß4 (Tß4) is expressed in developing tissue, where it stimulates cell differentiation and migration. Further, Tß4 is expressed during molar development in mice, but the expression and function of Tß4 in odontoblasts during mammalian tooth development have not yet been reported. Therefore, this study examined the expression and function of Tß4 in differentiating odontoblasts during tooth development. As observed by immunohistochemistry, Tß4 was expressed in the oral epithelium and inside cells of the tooth bud on embryonic day 15 (E15). Further, on E17, Tß4 was expressed strongly in the dental lamina and oral epithelium, but only expressed in part of the cells in the outer and inner dental epithelium. Tß4 was strongly expressed in the entire cytoplasm of odontoblasts on postnatal day 1 (PN1) and expressed intensively in the apical area of odontoblasts on PN4. Further, expression of Tß4 was increased gradually in odontoblasts from PN1 to PN21. In an odontoblast cell line, MDPC-23, expression of Tß4 mRNA and protein was increased strongly on day 4 and gradually decreased from day 14. The gene expression of dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), osteocalcin (OCN), osteonectin (ON), and collagen type I, related with mineralization, was significantly decreased in si-Tß4/MDPC-23 during differentiation compared to that in MDPC-23 cells. Taken together, our results suggest that Tß4 may be involved in oral epithelial cell proliferation at the initial stage of tooth development and regulates the expression and secretion of proteins during odontoblast differentiation.

Delayed healing and induction of secretory leukocyte protease inhibitor in polycystic ovary syndrome rat skin wounds.

Secretory leukocyte protease inhibitor (SLPI) and estrogen promote wound healing through a decrease in the excessive inflammatory response, accelerating re-epithelialization and increasing the amount of collagen deposition. The excessive administration of estradiol valerate (EV) using hormonal therapy decreases the concentration of estrogen abruptly and induces the polycystic ovary syndrome (PCOS). In this study, the PCOS rat skin wound area was wider than that of the normal groups and the rate of keratinocyte migration in PCOS was lower than the normal group. The numbers of inflammatory cells and macrophages recruited in the PCOS group were larger than that of the normal group. More collagen was deposited in the healing area of the normal group than in the PCOS group. The level of SLPI expression was higher in the PCOS group than the normal group after wounding, with the exception of the epithelium. On the other hand, mRNA and protein expression levels of transforming growth factor-ß1 (TGF-ß1) were lower in the PCOS group than in the normal group. Matrix metalloproteinase-2 (MMP-2) and MMP-9 levels in the PCOS group were significantly lower than that of the normal group. Therefore, increased SLPI in PCOS skin wounds may help prevent an excessive inflammatory response and aberrant collagen deposition but not are sufficient to accelerate PCOS skin wound healing, suggesting that SLPI may act as a local rather than a systemic modulating molecule in PCOS rat skin wounds.

Expression of dynamin II in odontoblast during mouse tooth development.

Odontoblasts secrete a collagen-based matrix and release numerous membrane-bound matrix vesicles, which are involved in dentin formation during tooth development. Dynamin II is a GTPase protein that contributes a variety of vesicular budding events, such as endocytotic membrane fission, caveolae internalization and protein trafficking in the Golgi apparatus. However, the expression and function of dynamin II in odontoblasts has not been reported. Therefore, this study examined the expression and possible role of dynamin II in odontoblasts during tooth development and mineralization. The levels of mRNA and protein expression in MDPC23 cells were significantly high at the early stages of differentiation and then decreased gradually thereafter. Immunohistochemistry showed that dynamin II was not expressed near the region of the odontoblasts at embryonic day 17 (E17) and E21. However, dynamin II was expressed strongly in the odontoblast layer at postnatal day 1 (PN1) and decreased gradually at PN3 and PN5. In addition, at PN15 in the functional stage, the dynamin II protein was also expressed in the odontoblast process as well as adjacent to the nuclear region. In conclusion, dynamin II may be involved in the transport of vesicles containing collageneous and non-collageneous proteins for dentin formation in odontoblast, suggesting that it is a good nanomolecule as a candidate to regulate the secretion of collagen on the bone and other nano material.

Induction of secretory leukocyte protease inhibitor (SLPI) in estradiol valerate (EV) induced polycystic ovary.

The excessive administration of estradiol valerate induces polycystic ovary syndrome by formation of follicular cysts. Secretory leukocyte protease inhibitor (SLPI) promotes wound healing by decreasing the excessive inflammatory response, stimulating keratinocyte proliferation and increasing collagen deposition through the inhibition of protease activity. In this study, SLPI expression was high in the ovarian stroma, corpus luteum, unilaminar primary follicle, multilaminar primary follicle and granulose layer of the antral follicle in polycystic ovary (PCO) compared to the normal ovary. SLPI was expressed strongly in the theca around the cyst in PCO compared to the mature follicle in the normal ovary. The levels of SLPI mRNA and protein expression were higher in PCO than in the normal ovary, and the level of MMP-2 expression was lower in PCO. These results showed that the formation of a cyst was initiated from a multilaminar primary follicle and SLPI expression was increased depending on the morphological changes in the follicle and ovarian stroma. Therefore, an increase in SLPI may be related to the suppression of tissue disruption, and act as a protease inhibitor in PCO, suggesting that SLPI increases independently of the estrogen concentration in pathological tissues.