BMP signaling inhibition overcomes chemoresistance of prostate cancer.

Chemoresistance is a major therapeutic challenge to prostate cancer and its underlying molecular mechanism is poorly understood. Previously, it has been suggested that bone morphogenetic protein (BMP) signaling is down-regulated during the prostate cancer progression from the early androgen-sensitive stage to the metastatic castration-resistant stage. However, no literature reports are available for BMP signaling in more advanced-chemoresistant prostate cancer. In this study, we found the expression levels of the BMP type I receptor members, Activin-like kinase-2 (ALK2) and Activin-like kinase-3 (ALK3), were significantly higher in the chemoresistant prostate cancer cells than those in the chemosensitive prostate cancer cells. In addition, the phospho-Smad1/5/9 proteins, the pivotal intracellular effectors of the BMP signaling, were notably elevated in the chemoresistant prostate cancer cells over the chemosensitive prostate cancer cells, indicating that BMP signaling is highly activated in the chemoresistant prostate cancer cells. We also found that BMP signaling inhibition with either DMH1 or the knockdown of ALK2/ALK3 sensitized chemoresistant prostate cancer cells to the chemotherapy drug docetaxel in a dose-dependent manner. Our further study indicates that DMH1 suppressed the migration and invasion of chemoresistant prostate cancer cells in vitro, and attenuated chemoresistant prostate tumor growth in the mouse xenograft model in vivo. In addition, we showed that DMH1 disrupted the sphere formation in DU145-TxR and PC3-TxR cells, and suppressed the expression of marker genes of the cancer stem cells (CSCs). In conclusion, our study demonstrates that BMP signaling is associated with prostate cancer chemoresistance and BMP signaling inhibition effectively overcomes the cancer chemoresistance potentially through the disruption of CSCs' stemness.

Effects of land use and landscape on the occurrence and distribution of microplastics in soil, China.

Microplastic pollution in the soil environment has gathered widespread attention. However, little is known about the effects of land use and landscape patterns on the occurrence and distribution of microplastics in the soil. Herein, the microplastic pollution in different land uses (facility farmland, traditional farmland, orchard, grassland, and woodland) in Yuanmou County, Yunnan Province was investigated. The results showed that the abundance of microplastic ranged from 50.000 to 3450.0 items·kg-1, with an average abundance of 595.00 ± 740.00 items·kg-1 and a median of 375.00 items·kg-1. Microplastics were found to primarily be green-coloured (28.4 %), fragment (72.7 %) in shape, <1 mm (75.7 %) in size, and composed of polypropylene (51.4 %). There were significant differences in the abundance and characteristics of the microplastics between different land use types. Microplastic abundance in facility farmlands, traditional farmlands, and orchard lands was significantly higher than that of grasslands and woodlands (p < 0.05). The main shape of the microplastics in facility farmlands, traditional farmlands, and orchards was fragments and it was fibers in grasslands and woodlands. The median particle size of microplastics in facility farmlands (539.50 µm) and traditional farmlands (574.00 µm), was smaller than those in the orchard (737.60 µm), grasslands (697.60 µm), and woodlands (1239.4 µm). Discrepancies among different land uses may be due to various reasons, such as different pollution sources and the weathering degree of microplastics. The results of the redundancy analysis showed that the microplastic abundance was negatively correlated with the largest patch index. It also showed that microplastic pollution was closely related to human activities. This study provides an important basis for further research on microplastic ecosystem risks that are associated with land use and provides a data basis for formulating effective prevention and control strategies and measures to mitigate soil microplastic pollution.

Mucoadhesive and Rheological Studies on the Co-Hydrogel Systems of Poly(Ethylene Glycol) Copolymers with Fluoroalkyl and Poly(Acrylic Acid).

A self-assembled co-hydrogel system with sol-gel two-phase coexistence and mucoadhesive properties was developed based on the combined properties of fluoroalkyl double-ended poly(ethylene glycol) (Rf-PEG-Rf) and poly(acrylic acid) (PAA), respectively. We have synthesized an Rf-PEG-g-PAA (where g denotes grafted) copolymer and integrated it into the Rf-PEG-Rf physically cross-linked micellar network to form a co-hydrogel system. Tensile strengths between the co-hydrogel surfaces and two different sets of mucosal surfaces were acquired. One mucosal surface was made of porcine stomach mucin Type II, while the other one is a pig small intestine. The experimental results show that the largest maximum detachment stresses (MDSs) were obtained when the Rf-PEG-g-PAA's weight percent in the dehydrated polymer mixture is ~15%. Tensile experiments also found that MDSs are greater in acidic conditions (pH = 4-5) (123.3 g/cm2 for the artificial mucus, and 43.0 g/cm2 for pig small intestine) and basic conditions (pH = 10.6) (126.9 g/cm2, and 44.6 g.cm2, respectively) than in neutral pH (45.4 g/cm2, and 30.7 g.cm2, respectively). Results of the rheological analyses using shear strain amplitude sweep and frequency sweep reveal that the Rf-PEG-g-PAA was physically integrated into the Rf-PEG-Rf micellar network, and the co-hydrogels remain physically cross-linked in three-dimensional micellar networks with long-term physical dispersion stability. Therefore, the co-hydrogel system is promising for drug delivery applications on mucosal surfaces.

A Novel TNM Classification for Colorectal Cancers based on the Metro-ticket Paradigm.

Background: Several revisions of the TNM classifications for colorectal cancer (CRC) have acknowledged that the oncological outcomes of stage IIB/IIC CRC are worse than those of stage IIIA. We aimed to develop a novel TNM (nTNM) classification based on the metro-ticket paradigm. Methods: We identified eligible CRC patients from the Surveillance, Epidemiology, and End Results database. The nTNM was developed using distance from the origin on a Cartesian plane incorporating the pN (x-axis) and pT (y-axis) stages, and was compared with the AJCC TNM classification. The areas under the curves (AUCs), calibration curves, and Akaike's information criterion (AIC) were used to evaluate the predictive performances of the two classifications. Clinical benefits were further estimated by decision curve analyses. The validation cohort was applied to validate these findings. Results: A total of 58,192 CRC patients (40,736 training cohort, 17,456 validation cohort) were finally included. In the training cohort, 18,476 patients (45.4%) experienced upstaging and 15,907 patients (39.0%) experienced downstaging in the nTNM classification compared with the TNM classification. Taking the prognosis of stage I as the reference, survival decreased with increasing nTNM stage. The nTNM classification showed better discrimination (AUC, 0.678 vs. 0.667, P<0.001), model-fitting (AIC, 236,525 vs. 237,741), and clinical benefits than the TNM classification. Similar results were found in the validation cohort. Conclusions: The nTNM classification for CRC has better predictive performances and superior accuracy for predicting prognosis compared with the TNM classification. The nTNM classification should therefore be considered in future revisions of the TNM classification.

A Modified Tumor-Node-Metastasis Classification for Stage III Colorectal Cancers Based on Treating Tumor Deposits as Positive Lymph Nodes.

Background: The tumor-node-metastasis classification of the American Joint Committee on Cancer classified tumor deposits (TDs) in patients with colorectal cancer (CRC) without lymph node (LN) metastasis as N1c, but the classification of TDs in patients with LN metastases remains controversial. This study investigated the probability of regarding TDs as positive LNs (pLNs) in pN stage and estimated its prognostic ability in CRC. Methods: We used the Surveillance, Epidemiology, and End Results program to analyze CRC patients who underwent surgical therapy (14,906 training cohort, 6,384 validation cohort). A modified pN stage (mpN) was identified using the number of pLNs plus TDs. Overall survival (OS) was analyzed using the Kaplan-Meier survival curves, and significant prognostic factors were identified by univariate and multivariate analyses. Prognostic ability was estimated using the area under the curve (AUC), calibration curve, and the Akaike's information criterion (AIC). Clinical benefit was measured by the decision curve analyses (DCA). The results were validated using the validation cohort. Results: Both the pN and mpN stages were independent prognostic factors in CRC according to univariate and multivariate analyses. The AUC analysis showed that the mpN stage had better prognostic discrimination for OS than the pN stage (0.612 vs. 0.605, P < 0.001). The AIC demonstrated that the mpN stage also showed superior model-fitting compared with the pN stage (49,756 vs. 49,841). The DCA further revealed that the mpN stage had better clinical benefits than the pN stage. The validation cohort showed similar findings. Conclusions: We concluded that counting TDs as pLNs may be superior to the pN stage when assessing the prognosis of CRC patients.

Effect of Type I Antifreeze Proteins on the Freezing and Melting Processes of Cryoprotective Solutions Studied by Site-Directed Spin Labeling Technique.

Antifreeze proteins (AFPs) protect organisms living in subzero environments from freezing injury, which render them potential applications for cryopreservation of living cells, organs, and tissues. Cryoprotective agents (CPAs), such as glycerol and propylene glycol, have been used as ingredients to treat cellular tissues and organs to prevent ice crystal's formation at low temperatures. To assess AFP's function in CPA solutions, we have the applied site-directed spin labeling technique to a Type I AFP. A two-step process to prevent bulk freezing of the CPA solutions was observed by the cryo-photo microscopy, i.e., (1) thermodynamic freezing point depression by the CPAs; and (2) inhibition to the growth of seed ice crystals by the AFP. Electron paramagnetic resonance (EPR) experiments were also carried out from room temperature to 97 K, and vice versa. The EPR results indicate that the spin labeled AFP bound to ice surfaces, and inhibit the growths of ice through the bulk freezing processes in the CPA solutions. The ice-surface bound AFP in the frozen matrices could also prevent the formation of large ice crystals during the melting processes of the solutions. Our study illustrates that AFPs can play an active role in CPA solutions for cryopreservation applications.

Mechanisms of antifreeze proteins investigated via the site-directed spin labeling technique.

The site-directed spin labeling (SDSL) technique was used to examine the antifreeze mechanisms of type-I antifreeze proteins (AFPs). The effects on the growth of seed ice crystals by the spin-label groups attached to different side chains of the AFPs were observed, and the states of water molecules surrounding the spin-label groups were probed via analyses of variable-temperature (VT) dependent electron paramagnetic resonance (EPR) spectra. The first set of experiments revealed the antifreeze activities of the spin-labeled AFPs at the microscopic level, while the second set of experiments displayed those at the molecular level. The experimental results confirmed the putative ice-binding surface (IBS) of type-I AFPs. The VT EPR spectra indicate that type-I AFPs can inhibit the nucleation of seed ice crystals down to ~ - 20 °C in their aqueous solutions. Thus, the present authors believe that AFPs protect organisms from freezing damage in two ways: (1) inhibiting the nucleation of seed ice crystals, and (2) hindering the growth of seed ice crystals once they have formed. The first mechanism should play a more significant role in protecting against freezing damage among organisms living in cold environments. The VT EPR spectra also revealed that liquid-like water molecules existed around the spin-labeled non-ice-binding side chains of the AFPs frozen within the ice matrices, and ice surrounding the spin-label groups melted at subzero temperatures during the heating process. This manuscript concludes with the proposed model of antifreeze mechanisms of AFPs based on the experimental results.

Effects of a type I antifreeze protein (AFP) on the melting of frozen AFP and AFP+solute aqueous solutions studied by NMR microimaging experiment.

The effects of a type I AFP on the bulk melting of frozen AFP solutions and frozen AFP+solute solutions were studied through an NMR microimaging experiment. The solutes studied include sodium chloride and glucose and the amino acids alanine, threonine, arginine, and aspartic acid. We found that the AFP is able to induce the bulk melting of the frozen AFP solutions at temperatures lower than 0 °C and can also keep the ice melted at higher temperatures in the AFP+solute solutions than those in the corresponding solute solutions. The latter shows that the ice phases were in super-heated states in the frozen AFP+solute solutions. We have tried to understand the first experimental phenomenon via the recent theoretical prediction that type I AFP can induce the local melting of ice upon adsorption to ice surfaces. The latter experimental phenomenon was explained with the hypothesis that the adsorption of AFP to ice surfaces introduces a less hydrophilic water-AFP-ice interfacial region, which repels the ionic/hydrophilic solutes. Thus, this interfacial region formed an intermediate chemical potential layer between the water phase and the ice phase, which prevented the transfer of water from the ice phase to the water phase. We have also attempted to understand the significance of the observed melting phenomena to the survival of organisms that express AFPs over cold winters.

Effect of sonographically guided cerebral glioma surgery on survival time.

OBJECTIVES: We investigated the value of intraoperative sonography in improving the prevalence of total tumor resection and the survival time of patients who underwent resection of cerebral gliomas. METHODS: One hundred thirty-seven patients who underwent sonographically guided surgery were followed for 6 to 60 months. In addition, 60 randomly selected patients (30 with low-grade gliomas and 30 with high-grade gliomas) who had surgery in our hospital without sonographic guidance served as the control group. Follow-up included the survival time, and the difference in the survival time between the study and control groups was statistically analyzed. RESULTS: Total removal of the lesion was achieved in 77 cases (69%), and partial removal was achieved in 35 (31%). In the control low-grade glioma group, 6-month survival was 96.7%; 1-year survival was 73.3%; and 2-year survival was 53.3%. In the study low-grade glioma group, survival rates at 6 months, 1 year, and 2 years were 98.0%, 96.1%, and 88.2%, respectively. In the control and study high-grade glioma groups, survival rates at 6 months, 1 year, and 2 years were 83.3% and 93.4%, 43.3% and 59.2%, and 13.3% and 32.8%. When comparing survival at 6 months, 1 year, and 2 years between the control and study groups, there was no significant difference at 6 months (P > .05), but survival at 1 and 2 years was significantly different (P < .05). CONCLUSIONS: Sonographically guided resection of cerebral gliomas helps the surgeon understand the relationship between the lesion and the surrounding structures. It is of value in improving the prevalence of total tumor resection and the patient's survival time.

Threonine side chain conformational population distribution of a type I antifreeze protein on interacting with ice surface studied via ¹³C-¹5N dynamic REDOR NMR.

Antifreeze proteins (AFPs) provide survival mechanism for species living in subzero environments by lowering the freezing points of their body fluids effectively. The mechanism is attributed to AFPs' ability to inhibit the growth of seed ice crystals through adsorption on specific ice surfaces. We have applied dynamic REDOR (Rotational Echo Double Resonance) solid state NMR to study the threonine (Thr) side chain conformational population distribution of a site-specific Thr ¹³C(γ) and ¹5N doubly labeled type I AFP in frozen aqueous solution. It is known that the Thr side chains together with those of the 4th and 8th Alanine (Ala) residues commencing from the Thrs (the 1st) in the four 11-residue repeat units form the peptide ice-binding surface. The conformational information can provide structural insight with regard to how the AFP side chains structurally interact with the ice surface. χ-squared statistical analysis of the experimental REDOR data in fitting the theoretically calculated dynamic REDOR fraction curves indicates that when the AFP interacted with the ice surface in the frozen AFP solution, the conformations of the Thr side chains changed from the anti-conformations, as in the AFP crystal structure, to partial population in the anti-conformation and partial population in the two gauche conformations. This change together with the structural analysis indicates that the simultaneous interactions of the methyl groups and the hydroxyl groups of the Thr side chains with the ice surface could be the reason for the conformational population change. The analysis of the theoretical dynamic REDOR fraction curves shows that the set of experimental REDOR data may fit a number of theoretical curves with different population distributions. Thus, other structural information is needed to assist in determining the conformational population distribution of the Thr side chains.

Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by H molecular diffusion NMR and F spin diffusion NMR.

R(f)-PEG (fluoroalkyl double-ended poly(ethylene glycol)) hydrogel is potentially useful as a drug delivery depot due to its advanced properties of sol-gel two-phase coexistence and low surface erosion. In this study, (1)H molecular diffusion nuclear magnetic resonance (NMR) and (19)F spin diffusion NMR were used to probe the drug loading and diffusion properties of the R(f)-PEG hydrogel for small anticancer drugs, 5-fluorouracil (FU) and its hydrophobic analog, 1,3-dimethyl-5-fluorouracil (DMFU). It was found that FU has a larger apparent diffusion coefficient than that of DMFU, and the diffusion of the latter was more hindered. The result of (19)F spin diffusion NMR for the corresponding freeze-dried samples indicates that a larger portion of DMFU resided in the R(f) core/IPDU intermediate-layer region (where IPDU refers to isophorone diurethane, as a linker to interconnect the R(f) group and the PEG chain) than that of FU while the opposite is true in the PEG-water phase. To understand the experimental data, a diffusion model was proposed to include: (1) hindered diffusion of the drug molecules in the R(f) core/IPDU-intermediate-layer region; (2) relatively free diffusion of the drug molecules in the PEG-water phase (or region); and (3) diffusive exchange of the probe molecules between the above two regions. This study also shows that molecular diffusion NMR combined with spin diffusion NMR is useful in studying the drug loading and diffusion properties in hydrogels for the purpose of drug delivery applications.

Model of drug-loaded fluorocarbon-based micelles studied by electron-spin induced (19)f relaxation NMR and molecular dynamics simulation.

Rf-IPDU-PEGs belong to a class of fluoroalkyl-ended poly(ethylene glycol) polymers (Rf-PEGs), where the IPDU (isophorone diurethane) functions as a linker to connect each end of the PEG chain to a fluoroalkyl group. The Rf-IPDU-PEGs form hydrogels in water with favorable sol-gel coexistence properties. Thus, they are promising for use as drug delivery agents. In this study, we introduce an electron-spin induced 19F relaxation NMR technique to probe the location and drug-loading capacity for an electron-spin labeled hydrophobic drug, CT (chlorambucil-tempol adduct), enclosed in the Rf-IPDU-PEG micelle. With the assistance of molecular dynamics simulations, a clear idea regarding the structures of the Rf-IPDU-PEG micelle and its CT-loaded micelle was revealed. The significance of this research lies in the finding that the hydrophobic drug molecules were loaded within the intermediate IPDU shells of the Rf-IPDU-PEG micelles. The molecular structures of IPDU and that of CT are favorably comparable. Consequently, it appears that this study opens a window to modify the linker between the Rf group and the PEG chain for achieving customized structure-based drug-loading capabilities for these hydrogels, while the advantage of the strong affinity among the Rf groups to hold individual micelles together and to interconnect the micellar network is still retained in hopes of maintaining the sol-gel coexistence of the Rf-PEGs.

[Clinical evaluation of fluor protector and glass-ionomer cement used as pit and fissure sealant for preventing pit and fissure caries in children].

PURPOSE: To study the clinical effect of the fluor protector and glass-ionomer cement used as pit and fissure sealant for preventing pit and fissure caries in children. METHODS: 622 health permanent teeth in 6-8 years old children were divided into three groups. Children in the experimental group A (n=207,335 teeth) underwent fluor protector every six months, experimental group B(n=205, 327 teeth) with glass-ionomer cement used as pit and fissure sealant and children in the control group(n=210, 354 teeth) underwent no treatment. The incidence of caries were compared among the three groups using SPSS10.0 software package after 3 years. RESULTS: After 3 years, the incidence of caries in A and B experimental groups were lower than in the control group, the difference was significant (P<0.01), but there were no significant difference between group A and group B (P>0.05). CONCLUSION: Fluor protector and glass-ionomer cement used as pit and fissure sealant also have good clinical effect in preventing caries.

Synthesis of chlorambucil-tempol adduct and its delivery using fluoroalkyl double-ended poly (ethylene glycol) micelles.

In our pursuit to find potent anticancer drugs, we have covalently bonded free radical tempol to chlorambucil giving a chlorambucil-tempol (CT) adduct in which both of the anticancer active sites in tempol and chlorambucil were left intact. Analysis using NMR, Maldi-TOF, and EPR verified the designed chemical structure. Because the CT adduct is more hydrophobic than chlorambucil, its delivery also was investigated using fluoroalkyl double-ended poly (ethylene glycol) (Rf-PEG) micelles. Results from EPR spectra and(19) F and(1) H NMR spin lattice relaxation times show that the Rf-PEG micelles are able to encapsulate CT into the Rf cores of the micelles.

Ice-surface adsorption enhanced colligative effect of antifreeze proteins in ice growth inhibition.

This Communication describes a mechanism to explain antifreeze protein's function to inhibit the growth of ice crystals. We propose that the adsorption of antifreeze protein (AFP) molecules on an ice surface induces a dense AFP-water layer, which can significantly decrease the mole fraction of the interfacial water and, thus, lower the temperature for a seed ice crystal to grow in a super-cooled AFP solution. This mechanism can also explain the nearly unchanged melting point for the ice crystal due to the AFP's ice-surface adsorption. A mathematical model combining the Langmuir theory of adsorption and the colligative effect of thermodynamics has been proposed to find the equilibrium constants of the ice-surface adsorptions, and the interfacial concentrations of AFPs through fitting the theoretical curves to the experimental thermal hysteresis data. This model has been demonstrated by using the experimental data of serial size-mutated beetle Tenebrio molitor (Tm) AFPs. It was found that the AFP's ice-surface adsorptions could increase the interfacial AFP's concentrations by 3 to 4 orders compared with those in the bulk AFP solutions.

[Clinical evaluation of two light cured pit and fissure sealants for preventing pit and fissure caries in children].

PURPOSE: To evaluate the clinical effect of two light cured pit and fissure sealants for preventing pit and fissure caries. METHODS: 416 health permanent teeth in 162 children aged 6 to 8 years old children were divided into two groups, enameloplasty sealant technique (EST) and cup-shaped brush sealant technique (CST) were used in two groups, respeitively. 90 and 112 contralateral healthy teeth were used as self controls respectively. The rate of the sealant reservation and the incidence of caries were compared in the two groups, and the clinical effect of the two groups was compared using SPSS10.0 software package for Chi-square test. RESULTS: After 3 years, the rate of the sealant reservation and the incidence of caries of EST were 85.4% and 0.9% respectively, the rate of the sealant reservation and the incidence of caries of CST were 63.8% and 6.7% respectively. Statistical analysis revealed a significant difference (P<0.05) between the two groups. CONCLUSION: EST and CST both have good clinical effects, While EST is superior to CST in preventing pit and fissure caries.

Insight into the binding of antifreeze proteins to ice surfaces via 13C spin lattice relaxation solid-state NMR.

The primary sequences of type I antifreeze proteins (AFPs) are Ala rich and contain three 11-residue repeat units beginning with threonine residues. Their secondary structures consist of alpha-helices. Previous activity study of side-chain mutated AFPs suggests that the ice-binding side of type I AFPs comprises the Thr side chains and the conserved i + 4 and i + 8 Ala residues, where i indicates the positions of the Thrs. To find structural evidence for the AFP's ice-binding side, a variable-temperature dependent (13)C spin lattice relaxation solid-state NMR experiment was carried out for two Ala side chain (13)C labeled HPLC6 isoforms of the type I AFPs each frozen in H(2)O and D(2)O, respectively. The first one was labeled on the equivalent 17th and 21st Ala side chains (i + 4, 8), and the second one on the equivalent 8th, 19th, and 30th Ala side chains (i + 6). The two kinds of labels are on the opposite sides of the alpha-helical AFP. A model of Ala methyl group rotation/three-site rotational jump combined with water molecular reorientation was tested to probe the interactions of the methyl groups with the proximate water molecules. Analysis of the T(1) data shows that there could be 10 water molecules closely capping an i + 4 or an i + 8 methyl group within the range of van der Waals interaction, whereas the surrounding water molecules to the i + 6 methyl groups could be looser. This study suggests that the side of the alpha-helical AFP comprising the i + 4 and i + 8 Ala methyl groups could interact with the ice surface in the ice/water interface.

Probing the interaction of solvents with the stationary phase of C18 high-performance liquid chromatographic column material by variable-temperature dependent 129Xe nuclear magnetic resonance spectroscopy.

VT (129)Xe NMR was applied to probe the interactions of solvents having different polarity indices with the stationary phase of a RP-C18 HPLC column material. It was observed that the highly polar ethylene glycol molecules do not mix with the alkyl chains of the RP-C18 stationary phase and the solvent is unable to enter the pores and the spaces between the particles. Three phases in this sample are defined as stationary/xenon phase, xenon gas phase (in the pores and the spaces between the particles) and ethylene glycol/xenon phase. In contrast to ethylene glycol, the nonpolar solvent cyclohexane was observed to be well mixed with the RP-C18 stationary phase. The capillary rise effect allows the solvent to enter the pores and the spaces between the particles. Two phases in this sample are defined as stationary/cyclohexane/xenon phase and cyclohexane/xenon phases. The properties of ethyl acetate are between those of ethylene glycol and cyclohexane. The (129)Xe NMR results show that the rational reversed phases should be conditioned from highly solvating to more polar solvents to remove the trapped air. The (129)Xe NMR results also show that pure stationary phase exists only when a highly polar solvent is used in reversed-phase chromatography. For a solvent with lower polarity, a stationary/solvent phase actually forms. This, together with the mobile phase, determines the selective factor for separating mixtures.

[A three-year clinical evaluation of ceramic optimized polymer posterior inlays].

PURPOSE: To evaluate the clinical results of ceramic optimized polymer (Targis) posterior inlays. METHODS: 345 type I cavities were divided into two groups: 170 in Targis inlays group (42 premolars and 128 molars) and 175 in control group (composite resin inlays, 45 premolars and 130 molars). The clinical effects of Targis inlays and composite resin inlays in posterior teeth were compared in marginal discoloration, marginal adaption, secondary caries, anatomic shape integrity, fractures of tooth and color match 3 years later. The data were analyzed using Chi-square test. RESULTS: 3 years after treatment, 166 Targis inlays were followed up, 2 had marginal discoloration, 158 had good marginal adaption, 162 had anatomic shape integrity, 1 had secondary caries, 161 had color match, and 5 had fractures of teeth. 169 composite resin inlays were followed up, 27 had marginal discoloration, 134 had good marginal adaption, 150 had anatomic shape integrity, 20 had secondary caries, 164 had color match,5 had fractures of teeth. The marginal discoloration, marginal adaption, secondary caries, anatomic shape integrity of Targis inlays were better than that of composite resin inlays (P < 0.05), but fractures of teeth was not different between inlays in the two group (P > 0.05). CONCLUSION: Targis posterior inlays is a good newly developed prosthesis.

[Observation of the change of blood pressure in 835 patients during extraction of teeth].

PURPOSE: To observe the change of blood pressure during extraction of teeth. METHODS: Patients without hypertension who needed extraction were randomly selected, tooth extraction was carried out. The blood pressure and the patient's response to operation were observed and recorded during the procedure. RESULTS: The blood pressure in 825 patients increased significantly. The average increased blood pressure was 45/26 mmHg, 3 patients had arrhythmia, 5 patients had adverse reaction. CONCLUSION: The patient's blood pressure must be fewer than 140/90 mmHg, before a difficult extraction of teeth.