β-catenin is Required in Odontoblasts for Tooth Root Formation

The tooth root is an important part of the tooth that works together with the surrounding periodontium to maintain the tooth in the alveolar socket. The root develops after crown morphogenesis. While the molecular and cellular mechanisms of early tooth development and crown morphogenesis have been extensively studied, little is known about the molecular mechanisms controlling tooth root formation. Here, we show that β-catenin is strongly expressed in odontoblast-lineage cells and is required for root formation. Tissue-specific inactivation of β-catenin in developing odontoblasts produced molars lacking roots and aberrantly thin incisors. At the beginning of root formation in the mutant molars, the cervical loop epithelium extended apically to form Hertwig’s epithelial root sheath (HERS), but root odontoblast differentiation was disrupted and followed by the loss of some HERS inner layer cells. However, the outer layer of the HERS extended without the root, and the mutant molars finally erupted. The periodontal tissues extensively invaded the dental pulp. These results indicate that there is a cell-autonomous requirement for Wnt/β-catenin signaling in the dental mesenchyme for root formation.

Serum concentrations of resistin and adiponectin and their relationship to insulin resistance in subjects with impaired glucose tolerance

OBJECTIVES

This study measured the serum concentrations of resistin and adiponectin in Chinese subjects with impaired glucose tolerance (IGT) and investigated their association with insulin resistance, metabolic parameters and circulating inflammatory markers.

METHODS

A total of 124 subjects participated in the study (44 with IGT and 80 with normal glucose tolerance [NGT]). Fasting serum concentrations of lipids, glucose, insulin and adipocytokines (resistin, adiponectin, leptin, tumour necrosis factor-α [TNF-α], interleukin-6 and C-reactive protein) were measured.

RESULTS

Serum resistin concentrations were similar in the IGT and NGT groups but were significantly higher in overweight/ obese IGT subjects than in those of normal weight. Serum adiponectin concentrations were significantly lower in the IGT group than in the NGT group. In the IGT group, resistin was positively correlated with age, body mass index and TNF-α, and adiponectin was correlated positively with high-density lipoprotein cholesterol and negatively with TNF-α and waist/hip ratio.

CONCLUSIONS

Circulating resistin is unlikely to be a major mediator of glucose tolerance in humans but it may have an inflammatory role in IGT. The data support the theory that circulating adiponectin has an anti-inflammatory and anti-insulin resistance function.

Excessive Wnt/β-catenin signaling disturbs tooth-root formation

BACKGROUND AND OBJECTIVE

Wingless-type MMTV integration site family (Wnt)/β-catenin signaling plays an essential role in cellular differentiation and matrix formation during skeletal development. However, little is known about its role in tooth-root formation. In a previous study, we found excessive formation of dentin and cementum in mice with constitutive β-catenin stabilization in the dental mesenchyme. In the present study we analyzed the molar roots of these mice to investigate the role of Wnt/β-catenin signaling in root formation in more detail.

MATERIAL AND METHODS

We generated OC-Cre:Catnb(+/lox(ex3)) mice by intercrossing Catnb(+/lox(ex3)) and OC-Cre mice, and we analyzed their mandibular molars using radiography, histomorphometry and immunohistochemistry.

RESULTS

OC-Cre:Catnb(+/lox(ex3)) mice showed impaired root formation. At the beginning of root formation in mutant molars, dental papilla cells did not show normal differentiation into odontoblasts; rather, they were prematurely differentiated and had a disorganized arrangement. Interestingly, SMAD family member 4 was upregulated in premature odontoblasts. In 4-wk-old mutant mice, molar roots were about half the length of those in their wild-type littermates. In contrast to excessively formed dentin in crown, root dentin was thin and hypomineralized in mutant mice. Biglycan and dentin sialophosphoprotein were downregulated in root dentin of mutant mice, whereas dentin matrix protein 1 and Dickkopf-related protein 1 were upregulated. Additionally, ectonucleotide pyrophosphatase/phosphodiesterase 1 was significantly downregulated in the cementoblasts of mutant molars. Finally, in the cementum of mutant mice, bone sialoprotein was downregulated but Dickkopf-related protein 2 was upregulated.

CONCLUSION

These results suggest that temporospatial regulation of Wnt/β-catenin signaling plays an important role in cell differentiation and matrix formation during root and cementum formation.

Polydatin Protects against Lipopolysaccharide-Induced Fulminant Hepatic Failure in D-Galactosamine-Sensitized Mice

Fulminant hepatic failure (FHF) is a devastating clinical syndrome with extremely poor prognosis and high mortality. Therefore, better treatment is urgently needed. Polydatin (PD), a traditional anti-inflammatory drug, has been described to protect against liver injury induced by certain hepatotoxins. The present study investigated the protective effect of PD against lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced FHF in mice and the underlying mechanism. Mice were pretreated with an increasing dose of PD (10, 30, and 100 mg/kg), following LPS/D-GalN challenge. The liver injury was assessed biochemically and histologically. We found that PD exerted a protective effect on LPS/D-GalN-induced FHF as evidenced by reducing sera alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, diminishing liver histopathological injury, and lowering mortality in a dose-dependent manner. In addition, pretreatment mice with PD dose-dependently suppressed tumor necrosis factor-α (TNF-α) production, myeloperoxidase (MPO) activity, intercellular adhesion molecule-1 (ICAM-1) and endothelial cell adhesion molecule-1 (ECAM-1) expression, caspase-3 activation, and transcription factor nuclear factor-kappa B(NF-kB) activity induced by LPS. These results suggested that PD could effectively protect from LPS/D-GalN-induced FHF and the protective effect afforded by PD probably contributed to reduce TNF-α production via inhibiting NF-kB activation.

Poster - Thur Eve - 70: Quantification of tumour dose enhancement at kilo-voltage energies due to the presence of gold nanoparticles during radiation therapy: EGSnrcMP Monte Carlo study

One of the greatest challenges in radiation therapy is the ability to deliver a lethal dose of radiation to a tumour while sparing the surrounding normal tissues. In theory, the dose delivered to a tumour during photon-based radiation therapy can be enhanced by loading high atomic number (Z) materials into the tumour, which results in greater photoelectric absorption and hence increased photoelectron fluence within the tumour than in surrounding tissues. The EGSnrcMP Monte Carlo code, together with DOSXYZnrc, a three-dimensional voxel dose calculation module has been used to study the macroscopic dose enhancement factor (MDEF) in a tumour infused with gold nanoparticles at the kilo-voltage energies. We observed that gold nanoparticles infused in a tumour irradiated with kilo-voltage energies has the potential to enhance the tumour dose by a factor ranging from 0.25 to about 5 depending on the mean energy of the beam and the concentration of gold nanoparticles in the tumour. The increase in dose can be attributed to the significant increase in the photoelectron fluence within the tumour loaded with gold particles during the irradiation. Future studies will involve the characterization of the MDEF at megavoltage energies.

Poster - Thur Eve - 77: Coordinate transformation from DICOM to DOSXYZnrc

DICOM format is the de facto standard for communications between therapeutic and diagnostic modalities. A plan generated by a treatment planning system (TPS) is often exported to DICOM format. BEAMnrc/DOSXYZnrc is a widely used Monte Carlo (MC) package for beam and dose simulations in radiotherapy. It has its own definition for beam orientation, which is not in compliance with the one defined in DICOM standard. Dose simulations using TPS generated plans require transformation of beam orientations to DOSXYZnrc coordinate system (c.s.) after extracting the necessary parameters from DICOM RP files. The transformation is nontrivial. There have been two studies for the coordinate transformations. The transformation equation sets derived have been helpful to BEAMnrc/DOSXYZnrc users. However, both the transformation equation sets are complex mathematically and not easy to program. In this study, we derive a new set of transformation equations, which are more compact, better understandable, and easier for computational implementation. The derivation of polar angle θ and azimuthal angle φ is similar to the existing studies by applying a series of rotations to a vector in DICOM patient c.s. The derivation of beam rotation Φ_col for DOSXYZnrc, however, is different. It is obtained by a direct combination of the actual collimator rotation with the projection of the couch rotation to the collimator rotating plane. Verification of the transformation has been performed using clinical plans created with Eclipse. The comparison between Eclipse and MC results show exact geometrical agreement for field placements, together with good agreement in dose distributions.

Sci-Thur AM: Planning - 12: Comparative study of SBRT lung dose calculation using Eclipse and Monte Carlo

Stereotactic Body Radiation Therapy (SBRT) is an option for early stage non-small cell lung cancer treatment. In SBRT treatment, high biological effective dose is delivered to the patient within a small number of fractions. High level of confidence in accuracy is required in the entire treatment procedure, from patient setup, tumour delineation, treatment simulation and planning, to the final dose delivery. SBRT lung treatment utilizes small fields that are incident on large tissue inhomogeneities within the patient. It is difficult for commercially available treatment planning systems (TPS) to model the lack of charged particle equilibrium and the dose near tissue-lung interfaces accurately. The Monte Carlo (MC) technique calculates the dose distribution from the first principles thereby providing a feasible tool for verifying the dose distribution computed from TPS. In this study, we compared the SBRT dose distribution between Eclipse 8.9 and BEAMnrc/DOSXYZnrc for both conformal and RapidArc plans. Calculation results for five clinical SBRT conformal lung plans were compared. Eclipse and MC results for each plan showed good agreement in dose received by organs at risk. MC simulation predicted uniformly hotter or similar PTV coverage for three cases with tumor either small or attached to the chest wall. When tumor is inside lung and at relatively medium to larger size for SBRT, MC predicted lower PTV coverage. The variation in dose coverage may depend on the tumour size and its position within the lung. Dose comparison for RapidArc plans shows similar dependence.

Subclinical atherosclerosis, airflow obstruction and emphysema: the MESA Lung Study

Airflow obstruction is an independent risk factor for cardiovascular events in the general population. The affected vascular bed and contribution of emphysema to cardiovascular risk are unclear. We examined whether an obstructive pattern of spirometry and quantitatively defined emphysema were associated with subclinical atherosclerosis in the carotid, peripheral and coronary circulations. The Multi-Ethnic Study of Atherosclerosis recruited participants aged 45-84 yrs without clinical cardiovascular disease. Spirometry, carotid intima-media thickness (IMT), ankle-brachial index (ABI) and coronary artery calcium (CAC) were measured using standard protocols. Percentage of emphysema-like lung was measured in the lung windows of cardiac computed tomography scans among 3,642 participants. Multiple linear regression was used to adjust for cardiac risk factors, including C-reactive protein. Decrements in forced expiratory volume in 1 s (FEV(1)) and FEV(1)/forced vital capacity ratio were associated with greater internal carotid IMT, particularly among smokers (p=0.03 and p<0.001, respectively) whereas percentage emphysema was associated with reduced ABI regardless of smoking history (p=0.004). CAC was associated with neither lung function (prevalence ratio for the presence of CAC in severe airflow obstruction 0.99, 95% CI 0.91-1.07) nor percentage emphysema. An obstructive pattern of spirometry and emphysema were associated distinctly and independently with subclinical atherosclerosis in the carotid arteries and peripheral circulation, respectively, and were not independently related to CAC.

Effect of ginsenoside Rg1 on proliferation and differentiation of human dental pulp cells in vitro

BACKGROUND

Human dental pulp cells (hDPCs) have the potency to proliferate and differentiate into odontoblasts and play an important role in dentine formation and reparation. The aim of the present study is to evaluate the effects of ginsenoside Rg1 on the proliferation and differentiation of hDPCs.

METHODS

hDPCs were incubated with different concentrations of ginsenoside Rg1 (0.1, 0.5, 2.5, 5, 10 and 20 μmol/L). The effects of ginsenoside Rg1 on the proliferative ability of hDPCs were evaluated by a fibroblast colony forming test, MTT assay and flow cytometry for cell cycle. The control group, osteogenic induction group, ginsenoside Rg1 (5 μmol/L) group and combination group were designed, and alkaline phosphatase (ALP) activity and FQ-PCR for gene expressions of dentine sialophosphoprotein (DSPP) and dentine matrix protein 1 (DMP1) were performed to evaluate the differentiation of hDPCs.

RESULTS

The proliferative ability of hDPCs in ginsenoside Rg1 was significantly enhanced (p < 0.05), especially in the ginsenoside Rg1 (5 μmol/L) group. ALP activity and gene expressions of DSPP and DMP1 were increased in the induction group, ginsenoside Rg1 group, and their combination group compared with the control group (p < 0.05).

CONCLUSIONS

The results indicate that ginsenoside Rg1 promotes the proliferation and differentiation of hDPCs.

Patterns of placental development evaluated by X chromosome inactivation profiling provide a basis to evaluate the origin of epigenetic variation

BACKGROUND

Inactivation of the maternally or paternally derived X chromosome (XCI) initially occurs in a random manner in early development; however as tissues form, a ‘patchiness’ will occur in terms of which X is inactivated if cells positioned near each other are clonally descended from a common precursor. Determining the relationship between skewed XCI in different tissues and in different samples from the same tissue provides a molecular assessment of the developmental history of a particular tissue that can then be used to understand how genetic and epigenetic variation arises in development.

METHODS

XCI skewing was evaluated in and compared between amnion, chorion, trophoblast and mesenchyme using multiple sampling sites from 14 term placentae. XCI was also evaluated in chorionic villus samples obtained at multiple sites and depths from four additional term placentae. The pattern of variation was then compared with methylation variation associated with the H19/IGF2 imprinting control region (ICR); promoter regions of KISS1, PTPN6, CASP8 and APC; and LINE-1 elements.

RESULTS

Mean placental level of skewing for amnion and chorion are correlated, consistent with a common developmental origin of at least a component of these membranes from inner cell mass derivatives subsequent to XCI, while trophoblast appears to be derived independently, consistent with its origin from the trophectoderm. Villus samples taken from different depths spanning the fetal to maternal side of the placenta were highly clonally related. Comparing patterns of clonal growth identified through XCI to the distribution of epigenetic variation in other genomic regions suggests that some variation arises early in development (e.g. LINE-1 methylation), whereas other variation arises predominantly after villus tree formation (e.g. methylation at H19/IGF2 ICR).

CONCLUSIONS

The patterns of XCI skewing are consistent with a model whereby each biopsied site of chorionic villi represents one or a few individual villus trees, each of which is clonally derived from only one or a few precursor cells. Sampling of placentae to evaluate changes associated with clinical pathology should be done with consideration of the tree-to-tree differences. A limitation of this study is the small number of placentas used and therefore placental-specific differences in variation could not be assessed.

Correlation between the band gap, elastic modulus, Raman shift and melting point of CdS, ZnS, and CdSe semiconductors and their size dependency

With structural miniaturization down to the nanoscale, the detectable quantities of solid materials no longer remain constant but become tunable. For the II-VI semiconductors example, the band gap expands, the elastic modulus increases, the melting point drops, and the Raman optical phonons experience red shift associated with creation of low frequency Raman acoustic modes that undergo blue shift with decreasing the dimensional scale. In order to understand the common origin of the size dependency of these seemingly irrelevant properties, we formulated these quantities for CdS, ZnS, and CdSe semiconductors from the perspectives of bond order-length-strength correlation and the local bond averaging approach. Consistency between the theory predictions and the measured size dependence of these quantities clarified that the undercoordination-induced local strain and quantum entrapment and the varied fraction of undercoordinated atoms of the entire solid correlate these quantities and dominate their size effect.

Novel magnetic chitosan/poly(vinyl alcohol) hydrogel beads: preparation, characterization and application for adsorption of dye from aqueous solution

Novel magnetic chitosan/poly(vinyl alcohol) hydrogel beads (m-CS/PVA HBs) were prepared by an instantaneous gelation method and characterized by X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). Results of characterization indicated that m-CS/PVA HBs have been prepared successfully without damaging the crystal structure of Fe(3)O(4) and their saturation magnetization were about 21.96 emu g(-1). The adsorption capacity of Congo Red on the m-CS/PVA HBs was 470.1 mg g(-1). The adsorption was well described by pseudo-second-order kinetics and Langmuir equation. Positive value of enthalpy change (ΔH(∘)) (13.32 kJ mol(-1)) showed that the adsorption was endothermic and physical in nature. The values of Gibbs free energy change (ΔG(∘)) were found to be -3.321 kJ mol(-1) at 298 K for m-CS/PVA HBs, indicating the spontaneity of Congo Red adsorption. Therefore, the m-CS/PVA HBs could be employed as a low-cost alternative to other adsorbents in the removal of dyes from aqueous solution.

Predictors of survival in patients with recurrent ovarian cancer undergoing secondary cytoreductive surgery based on the pooled analysis of an international collaborative cohort

BACKGROUND

This study aims to identify prognostic factors and to develop a risk model predicting survival in patients undergoing secondary cytoreductive surgery (SCR) for recurrent epithelial ovarian cancer.

METHODS

Individual data of 1100 patients with recurrent ovarian cancer of a progression-free interval at least 6 months who underwent SCR were pooled analysed. A simplified scoring system for each independent prognostic factor was developed according to its coefficient. Internal validation was performed to assess the discrimination of the model.

RESULTS

Complete SCR was strongly associated with the improvement of survival, with a median survival of 57.7 months, when compared with 27.0 months in those with residual disease of 0.1-1 cm and 15.6 months in those with residual disease of >1 cm, respectively (P<0.0001). Progression-free interval (≤23.1 months vs >23.1 months, hazard ratio (HR): 1.72; score: 2), ascites at recurrence (present vs absent, HR: 1.27; score: 1), extent of recurrence (multiple vs localised disease, HR: 1.38; score: 1) as well as residual disease after SCR (R1 vs R0, HR: 1.90, score: 2; R2 vs R0, HR: 3.0, score: 4) entered into the risk model.

CONCLUSION

This prognostic model may provide evidence to predict survival benefit from secondary cytoreduction in patients with recurrent ovarian cancer.

New red flower germplasm lines of cotton selected from hybrid ofGossypium hirsutum XG. bickii

By means of dropping GA(3)(50 ppm) and NAA (40 ppm) on the hybrid boll-embryo culturein vitro, one F(1) plant ofG. hirsutum x G. bickii was obtained; when F(1) branches were grafted on upland cotton and then back-crossed with upland cotton under short-day and cooler-night condition, some BC(1) seeds could be harvested. The characteristic segregation was very violent in early generation. Through 3 times of back-crossing and selecting, ten stable hybrid lines with the character of both male parent (viz. red petal-purple spot and strong fibre) and female parent (plant type, earliness, white fibre, lint length, etc.) were established. These lines were assigned as HB red flower lines (HBRL). Transference of character ofG. bickii to upland cotton was proved to be successful for the first time. These new germplasms may play an important role in both the genetic research and new cotton variety breeding.