[Recurrent epistaxis with coagulation disorders in a boy aged 2 years]. / 2岁男孩反复鼻衄伴凝血功能异常.

A boy, aged 2 years and 5 months, had recurrent epistaxis, and the coagulation function examination showed that activated partial thromboplastin time (APTT) was significantly prolonged. Further laboratory examinations showed that the prolonged APTT was not immediately corrected in the APTT correction test, with positive lupus anticoagulant and low prothrombin activity. The boy was diagnosed with hypoprothrombinemia-lupus anticoagulant syndrome. The condition was improved after treatment with glucocorticoid, immunoglobulin, and vitamin K1. The boy has been followed up for 6 months, and no epistaxis was observed. Prothrombin activity returned to normal, and lupus anticoagulant remained positive. This is a relatively rare disease, and for patients with bleeding symptoms and coagulation disorders, it is recommended to perform the tests such as APTT correction test, lupus anticoagulant testing, and coagulation factor dilution test, which can improve the detection rate of this disease, so as to achieve early diagnosis, provide rational treatment in the early stage, and improve the prognosis.

Design and synthesis of 4-anilinoquinazolines as Raf kinase inhibitors. Part 1. Selective B-Raf/B-RafV600E and potent EGFR/VEGFR2 inhibitory 4-(3-hydroxyanilino)-6-(1H-1,2,3-triazol-4-yl)quinazolines.

This paper presents the design and synthesis of 4-(3-hydroxyanilino)-6-(1H-1,2,3-triazol-4-yl)quinazolines of scaffold 9 as selective B-Raf/B-RafV600E and potent EGFR/VEGFR2 kinase inhibitors. Total 14 compounds of scaffold 9 having different side chains at the triazolyl group with/without fluoro substituents at the anilino group were synthesized and investigated. Among them, 9m with a 2-carbamoylethyl side chain and C-4'/C-6' difluoro substituents was the most potent, which selectively inhibited B-Raf (IC50: 57 nM) and B-RafV600E (IC50: 51 nM) over C-Raf (IC50: 1.0 µM). Compound 9m also actively inhibited EGFR (IC50: 73 nM) and VEGFR2 (IC50: 7.0 nM) but not EGFRT790M and PDGFR-ß (IC50: >10 µM). Despite having good potency for B-Raf and B-RafV600E in the enzymatic assays, 9m was less active to inhibit melanoma A375 cells which proliferate due to constitutively activated B-Raf600E. The inferior activity of 9m for A375 was similar to that of sorafenib (6), suggesting that 9m might bind to the inactive conformations of B-Raf and B-RafV600E. Docking simulations could thus be performed to reveal the binding poses of 9m in B-Raf, B-RafV600E, and VEGFR2 kinases.

Hyperthermia inhibited the migration of tongue squamous cell carcinoma through TWIST2.

BACKGROUND: Hyperthermia has been shown promising in the treatment of head and neck squamous cell carcinoma (HNSCC); however, the mechanism underlying hyperthermia reducing tumor metastasis is poorly elucidated. TWIST2, an important transcription factor of epithelial-mesenchymal transition (EMT), plays a critical role in the tumor progression and metastasis. The role of TWIST2 in tongue squamous cell carcinoma (TSCC) and its association with hyperthermia still have not been reported. METHOD: The correlations between TWIST2 expression and the clinical-pathologic characteristics of 89 patients with TSCC were evaluated by immunohistochemical staining. TSCC cell lines transfected with siRNA against TWIST2 were heated for 40 min at 42.5°C, and the migration capability of cells was examined by migration assay. Xenograft tumors in nude mice were treated by hyperthermia, and TWIST2 expression was measured. RESULTS: Our data showed that TWIST2 expression was associated with the metastasis of human TSCC. In Tca8113 and Cal-27 cells, TWIST2-siRNA treatment can reduce cell migration ability and has no effect on the cell proliferation and apoptosis. Hyperthermia can decrease the level of TWIST2 in TSCC and inhibit the migration of cells. CONCLUSIONS: This demonstrated that hyperthermia might decrease the migration of Tca8113 and Cal-27 cells by reducing TWIST2 expression. Altogether, these findings suggest an as yet undescribed link between TWIST2 and hyperthermia in TSCC.

Parental weight changes as key predictors of child weight changes.

BACKGROUND: Parents are the key agents of behavioural changes in their children. This fact is as an important aspect of obesity treatment and prevention. The present study aims to evaluate the influence of parents who have gained or lost weight on their children's weights and to examine parental and child patterns of weight changes from a baseline over a 14-year duration. METHODS: We performed a secondary analysis on the Indonesia Family Life Survey (IFLS), an ongoing national prospective longitudinal cohort study in Indonesia. Height and weight measurements, information regarding parental education, maternal employment, household income, and residence were collected from children under five years old (n = 3,147) and their parents in 1993. Data were taken from the same individuals at different points in time, in 1997, 2000, and 2007. RESULTS: During each transition, the children of parents who gained weight had a significantly weights than did children of parents who lost weight. A mother's positive weight change increased the chance of her pre-schooler's or school-aged child's positive weight change. However we found no such association between a father's positive weight change and his child's positive weight change. CONCLUSIONS: Parental weight change is an independent predictor of child weight change. Positive weight change in the mother had a more dominant influence than did the father's positive weight change. Future family-based obesity prevention and treatment programs should consider how best to include and engage mothers as a catalyst for the reduction of obesity-related risk factors in the long term.

Drug­resistant Acinetobacter baumannii: From molecular mechanisms to potential therapeutics (Review).

Bacterial drug resistance is increasingly becoming an important problem that needs to be solved urgently in modern clinical practices. Infection caused by Acinetobacter baumannii is a serious threat to the life and health of patients. The drug resistance rate of Acinetobacter baumannii strains is increasing, thus research on the drug resistance of Acinetobacter baumannii has also seen an increase. When patients are infected with drug-resistant Acinetobacter baumannii, the availability of suitable antibiotics commonly used in clinical practices is becoming increasingly limited and the prognosis of patients is worsening. Studying the molecular mechanism of the drug resistance of Acinetobacter baumannii is fundamental to solving the problem of drug-resistant Acinetobacter baumannii and potentially other 'super bacteria'. Drug resistance mechanisms primarily include enzymes, membrane proteins, efflux pumps and beneficial mutations. Research on the underlying mechanisms provides a theoretical basis for the use and development of antibiotics and the development of novel treatment methods.

Highly reliable GIGA-sized synthetic human therapeutic antibody library construction.

Background: Monoclonal antibodies (mAbs) and their derivatives are the fastest expanding category of pharmaceuticals. Efficient screening and generation of appropriate therapeutic human antibodies are important and urgent issues in the field of medicine. The successful in vitro biopanning method for antibody screening largely depends on the highly diverse, reliable and humanized CDR library. To rapidly obtain potent human antibodies, we designed and constructed a highly diverse synthetic human single-chain variable fragment (scFv) antibody library greater than a giga in size by phage display. Herein, the novel TIM-3-neutralizing antibodies with immunomodulatory functions derived from this library serve as an example to demonstrate the library's potential for biomedical applications. Methods: The library was designed with high stability scaffolds and six complementarity determining regions (CDRs) tailored to mimic human composition. The engineered antibody sequences were optimized for codon usage and subjected to synthesis. The six CDRs with variable length CDR-H3s were individually subjected to ß-lactamase selection and then recombined for library construction. Five therapeutic target antigens were used for human antibody generation via phage library biopanning. TIM-3 antibody activity was verified by immunoactivity assays. Results: We have designed and constructed a highly diverse synthetic human scFv library named DSyn-1 (DCB Synthetic-1) containing 2.5 × 1010 phage clones. Three selected TIM-3-recognizing antibodies DCBT3-4, DCBT3-19, and DCBT3-22 showed significant inhibition activity by TIM-3 reporter assays at nanomolar ranges and binding affinities in sub-nanomolar ranges. Furthermore, clone DCBT3-22 was exceptionally superior with good physicochemical property and a purity of more than 98% without aggregation. Conclusion: The promising results illustrate not only the potential of the DSyn-1 library for biomedical research applications, but also the therapeutic potential of the three novel fully human TIM-3-neutralizing antibodies.

Establishment and verification a nomogram for predicting portal vein thrombosis presence among admitted cirrhotic patients.

Background: Portal vein thrombosis (PVT) is an increasingly recognized complication of cirrhosis and possibly associated with mortality. This study aims to evaluate provoking factors for PVT, then establish a concise and efficient nomogram for predicting PVT presence among admitted cirrhotic patients. Materials and methods: All cirrhotic patients admitted in Hunan Provincial People's Hospital between January 2010 and September 2020 were retrospectively reviewed, the clinical and laboratory data were collected. Multivariate logistic regression analysis and the least absolute shrinkage and selection operator regression method were used for screening the independent predictors and constructing the nomogram. The calibration curve was plotted to evaluate the consistent degree between observed outcomes and predicted probabilities. The area under the receiver operating characteristics curve was used to assess the discriminant performance. The decision curve analysis (DCA) was carried out to evaluate the benefits of nomogram. Results: A total of 4,479 patients with cirrhosis were enrolled and 281 patients were identified with PVT. Smoking history, splenomegaly, esophagogastric varices, surgical history, red blood cell transfusion, and D-dimer were independent risk factors for PVT in cirrhosis. A nomogram was established with a good discrimination capacity and predictive efficiency with an the area under the curve (AUC) of 0.704 (95% CI: 0.664-0.745) in the training set and 0.685 (95% CI: 0.615-0.754) in the validation set. DCA suggested the net benefit of nomogram had a superior risk threshold probability. Conclusion: A concise and efficient nomogram was established with good performance, which may aid clinical decision making and guide best treatment measures.

Novel Polymerization of Dental Composites Using Near-Infrared-Induced Internal Upconversion Blue Luminescence.

Blue light (BL) curing on dental resin composites results in gradient polymerization. By incorporating upconversion phosphors (UP) in resin composites, near-infrared (NIR) irradiation may activate internal blue emission and a polymerization reaction. This study was aimed to evaluate the competency of the NIR-to-BL upconversion luminance in polymerizing dental composites and to assess the appropriate UP content and curing protocol. NaYF4 (Yb3+/Tm3+ co-doped) powder exhibiting 476-nm blue emission under 980-nm NIR was adapted and ball-milled for 4-8 h to obtain different particles. The bare particles were assessed for their emission intensities, and also added into a base composite Z100 (3M EPSE) to evaluate their ability in enhancing polymerization under NIR irradiation. Experimental composites were prepared by dispensing the selected powder and Z100 at different ratios (0, 5, 10 wt% UP). These composites were irradiated under different protocols (BL, NIR, or their combinations), and the microhardness at the irradiated surface and different depths were determined. The results showed that unground UP (d50 = 1.9 µm) exhibited the highest luminescence, while the incorporation of 0.4-µm particles obtained the highest microhardness. The combined 20-s BL and 20-120-s NIR significantly increased the microhardness on the surface and internal depths compared to BL correspondents. The 5% UP effectively enhanced the microhardness under 80-s NIR irradiation but was surpassed by 10% UP with longer NIR irradiation. The combined BL-NIR curing could be an effective approach to polymerize dental composites, while the intensity of upconversion luminescence was related to specific UP particle size and content. Incorporation of 5-10% UP facilitates NIR upconversion polymerization on dental composites.

Synthesis of selenophene derivatives as novel CHK1 inhibitors.

A series of selenophene derivatives 3 were synthesized as potential CHK1 inhibitors. The effects of substitution on the 4'- or 5'-position of selenophene moiety and shifting the hydroxyl group position on C6- phenolic ring of oxindole were explored. This study led to the discovery of the most potent CHK1 inhibitors 29-33 and 39-43, which had IC(50) values in the subnanomolar range.

Direct involvement of the tumor suppressor p53 in nucleotide excision repair.

The tumor suppressor p53 enhances repair of UVC-induced DNA damage. The comet-NE assay, a conventional alkaline comet assay which includes a nuclear digestion step, was used to examine the effects of p53 on the excision activity of nuclear extracts (NEs). In contrast with untreated NEs, NEs immunodepleted of p53 or NEs of p53-null cells were unable to excise UVC-induced DNA adducts. Introduction of p53 by transfection restored the excision activity to NEs of p53-null cells. Deletion of the N-terminal 99 amino acids and/or the C-terminal 85 amino acids of p53 barely affected the excision activity, whereas further deletion of the C-terminus of p53 by another 10 amino acids completely abolished the excision activity of NEs. Immunostaining following localized UV irradiation was used to examine the effects of p53 on the recruitment of repair proteins for nucleotide excision repair (NER). Although recruitment of XPC occurred regardless of the presence of p53, the recruitment of XPB was p53-dependent. However, p53 with the 95 amino acid deletion at its C-terminus was unable to support this recruitment of XPB. Consistently, intact p53 (but not the C-terminal 95 residue truncated version) was detected in co-immunoprecipitation assays with an anti-XPB antibody. These results support the hypothesis that p53 facilitates NER through direct involvement by protein-protein interactions.

Expression of tumor suppressor p53 facilitates DNA repair but not UV-induced G2/M arrest or apoptosis in Chinese hamster ovary CHO-K1 cells.

Tumor suppressor p53 is an essential regulator in mammalian cellular responses to DNA damage including cell cycle arrest and apoptosis. Our study with Chinese hamster ovary CHO-K1 cells indicates that when p53 expression and its transactivation capacity was inhibited by siRNA, UVC-induced G2/M arrest or apoptosis were unaffected as revealed by flow cyotmetric analyses and other measurements. However, inhibition of p53 rendered the cells slower to repair UV-induced damages upon a plasmid as shown in host cell reactivation assay. Furthermore, the nuclear extract (NE) of p53 siRNA-treated cells was inactive to excise the UV-induced DNA adducts as analyzed by comet assay. Consistently, the immunodepletion of p53 also deprived the excision activity of the NE in the similar experiment. Thus, tumor suppressor p53 of CHO-K1 cells may facilitate removal of UV-induced DNA damages partly via its involvement in the repair mechanism.

Postures of upper extremity correlated with carpal tunnel syndrome (CTS).

OBJECTIVES: Non-medical hospital staff members are in frequent contact with patients and therefore are required to perform a wide variety of repetitive and high-frequency activities. The objective of this study was to assess the relationships between upper extremity activity and carpal tunnel syndrome (CTS) among non-medical hospital staff members. MATERIAL AND METHODS: Carpal tunnel syndrome in 144 non-medical hospital staff members was diagnosed using the Nordic Musculoskeletal Questionnaire (NMQ), a physician's diagnosis, physical examination (Tinel's signs and Phalen test) and a nerve conduction velocity (NCV) test. In addition, an ergonomic assessment was performed and a video camera was used to record the physical activities at work. RESULTS: The prevalence rate of CTS was highest for the NMQ (51.9%), followed by physician's diagnosis (49.5% for the right hand, 29.9% for the left hand), physical examination (54.7%), and nerve conduction test (motor nerve 27.5% and 25%, sensory nerve 21.7% and 15%, for right and left hands, respectively). Based on logistic regression models for the NMQ and physician's diagnoses, there was a dose-dependently higher risk of CTS with the upper extremity index among participants, but this was non-significant based on the physical examination and nerve conduction tests. CONCLUSIONS: Nerve conduction velocity is the gold standard in diagnosis of CTS, but use of NMQ and physician's diagnosis may overestimate the incidence of CTS in workers who have been engaging in repetitive stress activities for a relatively short time. Int J Occup Med Environ Health 2017;30(2):281-290.

The Effects of PM2.5 from Asian Dust Storms on Emergency Room Visits for Cardiovascular and Respiratory Diseases.

A case-crossover study examined how PM2.5 from Asian Dust Storms (ADS) affects the number of emergency room (ER) admissions for cardiovascular diseases (CVDs) and respiratory diseases (RDs). Our data indicated that PM2.5 concentration from ADS was highly correlated with ER visits for CVDs and RDs. The odds ratios (OR) increased by 2.92 (95% CI: 1.22-5.08) and 1.86 (95% CI: 1.30-2.91) per 10 µg/m³ increase in PM2.5 levels, for CVDs and RDs, respectively. A 10 µg/m³ increase in PM2.5 from ADSs was significantly associated with an increase in ER visits for CVDs among those 65 years of age and older (an increase of 2.77 in OR) and for females (an increase of 3.09 in OR). In contrast, PM2.5 levels had a significant impact on RD ER visits among those under 65 years of age (OR = 1.77). The risk of ER visits for CVDs increased on the day when the ADS occurred in Taiwan and the day after (lag 0 and lag 1); the corresponding risk increase for RDs only increased on the fifth day after the ADS (lag 5). In Taiwan's late winter and spring, the severity of ER visits for CVDs and RDs increases. Environmental protection agencies should employ an early warning system for ADS to reduce high-risk groups' exposure to PM2.5.

A RRAM Integrated 4T SRAM with Self-Inhibit Resistive Switching Load by Pure CMOS Logic Process.

This paper reports a novel full logic compatible 4T2R non-volatile static random access memory (nv-SRAM) featuring its self-inhibit data storing mechanism for in low-power/high-speed SRAM application. With compact cell area and full logic compatibility, this new nv-SRAM incorporates two STI-ReRAMs embedded inside the 4T SRAM. Data can be read/write through a cross-couple volatile structure for maintaining fast accessing speed. Data can be non-volatilely stored in new SRAM cell through a unique self-inhibit operation onto the resistive random access memory (RRAM) load, achieving zero static power during data hold.

A low serum Tat-interacting protein 30 level is a diagnostic and prognostic biomarker for hepatocellular carcinoma.

The present study aimed to evaluate the diagnostic and prognostic value of Tat-interacting protein 30 (HTATIP2/TIP30) levels alone and in combination with α-fetoprotein (AFP) for the evaluation of hepatocellular carcinoma (HCC) patients. ELISA and immunohistochemical measurements on the serum and tissue of HTATIP2/TIP30 protein from HCC patients and normal controls were made. Receiver operating characteristic (ROC) curve analyses of AFP and HTATIP2/TIP30 were performed, as well as logistic regression analysis of APF combined with HTATIP2/TIP30. Log-rank analysis was used to correlate the prognosis with various levels of HTATIP2/TIP30. HTATIP2/TIP30 levels were significantly lower in the HCC group compared with the control group (4.50±2.63 vs. 9.50±2.04 ng/ml, P<0.001). ROC analysis revealed an optimal cut-off point at 7.27 ng/ml HTATIP2/TIP30 for separating the HCC from the control groups. The sensitivity and specificity were 84.6 and 93.7% (P<0.001), respectively. ROC areas of HTATIP2/TIP30 (0.928, P<0.001) were significantly higher than those for AFP (P<0.001). The area under the curve of the HTATIP2/TIP30 and AFP combination was 0.950 (P<0.001). Log-rank tests revealed that the recurrence-free survival time of the group with HTATIP2/TIP30>5.71 ng/ml was significantly higher than that of the control group (P<0.001). This is the first study to demonstrate that HTATIP2/TIP30 levels in serum may be an effective biomarker for the diagnosis and prognosis of HCC.

Indirect regulation of human dehydroepiandrosterone sulfotransferase family 1A member 2 by thyroid hormones.

Thyroid hormone, T(3), regulates cell metabolism, differentiation, and development. cDNA microarrays were performed to study the mechanism of target gene regulation after T(3) treatment in a thyroid hormone receptor-alpha (TRalpha)-overexpressing hepatoma cell line (HepG2-TRalpha). The differentially expressed target genes are several metabolic enzymes, including dehydroepiandrosterone-sulfotransferase family 1A member 2 (SULT2A1). Enzyme SULT2A1 was elevated roughly 5-fold at the protein level and 9-fold increase at the mRNA level after 48 h T(3) treatment in HepG2-TRalpha cells. Cycloheximide inhibited T(3)-induced SULT2A1 expression, suggesting that regulation was indirect. SULT2A1 has been reported to be regulated by the two transcription factors, steroidogenic factor 1 (SF1) and GATA, in the human adrenal gland. T(3) induced a 2.5- to 3.5-fold elevation of SF1 at the protein level and a 6.2-fold increase at the RNA level in HepG2-TRalpha cells. About seven SF1 binding sites exist on the SULT2A1 gene. To identify and localize the critical SF1 binding site, series of deletion mutants of SULT2A1 promoter fragments in pGL2 plasmid were constructed. The promoter activity of the SULT2A1 gene was enhanced about 2.8- to 7.1-fold by T(3). The -228 SF1 binding site was identified as the most critical site because deleting this region reduced T(3)-induced expression. Transcription factor SF1 application enhanced the -228 but not -117 reporter plasmid activities. SULT2A1 and SF1 up-regulation at protein and RNA levels in thyroidectomized rats occurred after T(3) application. In summary, this work demonstrated that the SULT2A1 gene was mediated by SF1 and indirectly regulated by T(3). Further study is required to elucidate the physiological importance of SULT2A1 induction mediated by T(3).

Mediation of the inhibitory effect of thyroid hormone on proliferation of hepatoma cells by transforming growth factor-beta.

Thyroid hormone (triiodothyronine, T3) regulates growth, development and differentiation. To examine the influence of T3 on hepatoma cell growth, thyroid receptor (TR)alpha1 or TRbeta1 over-expressing HepG2 cell lines were used. Growth of the HepG2-TR stable cell line was inhibited by over 50% following treatment with T3. However, transforming growth factor (TGF)-beta neutralizing antibody, but not the control antibody can reverse the cell growth inhibition effect of T3. Flow cytometric analysis indicated that the growth inhibition was apparent at the transition point between the G1 and S phases of the cell cycle. The expression of major cell cycle regulators was used to provide further evidence for the growth inhibition. Cyclin-dependent kinase 2 (cdk2) and cyclin E were down-regulated in HepG2-TR cells. Moreover, p21 protein or mRNA levels were up-regulated by around 5-fold or 7.3-fold respectively following T3 treatment. Furthermore, phospho-retinoblastoma (ppRb) protein was down-regulated by T3. The expression of TGF-beta was studied to delineate the repression mechanism. TGF-beta was stimulated by T3 and its promoter activity was enhanced six- to eight-fold by T3. Furthermore, both T3 and TGF-beta repressed the expression of cdk2, cyclin E and ppRb. On the other hand, TGF-beta neutralizing but not control antibody blocked the repression of cdk2, cyclin E and ppRb by T3. These results demonstrated that T3 might play a key role in liver tumor cell proliferation.

Association of Maternal and Child Health Center (Posyandu) Availability with Child Weight Status in Indonesia: A National Study.

Little is known about the childhood obesity prevention and treatment practices of Maternal and Child Health services (Posyandu) in Indonesia or in other countries. The present study aims to assess the association of the availability of Posyandu with overweight and obesity in children of different household wealth levels. This was a secondary analysis of data collected in the 2013 Riskesdas (or Basic Health Research) survey, a cross-sectional study, representative population-based data. Height and weight, the availability of Posyandu, and basic characteristics of the study population were collected from parents with children aged 0 to 5 years (n = 63,237). Non-availability of Posyandu significantly raised the odds of being obese (OR = 1.13, 95% CI: 1.06-1.21) and did not show a significant relationship in the odds for overweight (OR = 0.99, 95% CI: 0.93-1.07). This relationship persisted after a full adjustment (OR = 1.16, 95% CI: 1.07-1.25 and OR = 1.04, 95% CI: 0.96-1.13, respectively). There was effect modification by household wealth, which was stronger for obese children. The availability of Posyandu has a protective association with childhood obesity in Indonesia. Posyandu services are well placed to play an important role in obesity prevention and treatment in early life.

Colcemid inhibits the rejoining of the nucleotide excision repair of UVC-induced DNA damages in Chinese hamster ovary cells.

In our previous study, we found that colcemid, an inhibitor of mitotic spindle, promotes UVC-induced apoptosis in Chinese hamster ovary cells (CHO.K1). In this study, a brief treatment of colcemid on cells after but not before UV irradiation could synergistically reduce the cell viability. Although colcemid did not affect the excision of UV-induced DNA damages such as [6-4] photoproducts or cyclobutane pyrimidine dimers, colcemid accumulated the DNA breaks when it was added to cells following UV-irradiation. This colcemid effect required nucleotide excision repair (NER) since the same accumulation of DNA breaks was barely or not detected in two NER defective strains of CHO cells, UV5 or UV24. Furthermore, the colcemid effect was not due to semi-conservative DNA replication or mitosis since the colcemid-caused accumulation of DNA breaks was also seen in non-replicating cells. Moreover, colcemid inhibited rejoining of DNA breaks accumulated by hydroxyurea/cytosine arabinoside following UV irradiation. Nevertheless, colcemid did not affect the unscheduled DNA synthesis as assayed by the incorporation of bromodeoxyuridine. Taken together, our results suggest that colcemid might inhibit the step of ligation of NER pathways.

[Effect of thermal cycling on surface microstructure of different light-curing composite resins].

OBJECTIVE: To evaluate the effect of thermal cycling on surface microstructure of different light-curing composite resins. METHODS: A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from lateral to center to form cubic specimens. The lateral surfaces were abrased and polished before water storage and 40 000 thermal cycles (5/55 degrees celsius;). The mean surface roughness (Ra) were measured and compared before and after thermal cycling, and the changes of microstructure were observed under scanning electron microscope (SEM). RESULTS: Significant decreases of Ra were observed in the composites, especially in Spectrum (from 0.164±0.024 µm to 0.140±0.017 µm, P<0.001) and Z250 (from 0.169±0.035 µm to 0.144±0.033 µm, P<0.001), whose Ra approximated that of P60 (0.121±0.028 µm) with smoothly polished surface. SEM revealed scratches and shallower pits on the surface of all the 5 resins, and fissures occurred on Z350 following the thermal cycling. CONCLUSION: Water storage and thermal cycling may produce polishing effect on composite resins and cause fissures on nanofilled composite resins.