A Bilayer Method for Measuring Toughness and Strength of Dental Ceramics

The ever-increasing usage of ceramic materials in restorative dentistry necessitates a simple and effective method to evaluate flexural strength σF and fracture toughness KC. We propose a novel method to determine these quantities using a bilayer specimen composed of a brittle plate adhesively bonded onto a transparent polycarbonate substrate. When this bilayer structure is placed under spherical indentation, tunneling radial cracks initiate and propagate in the lower surface of the brittle layer. The failure analysis is based on previous theoretical relationships, which correlate σF with the indentation force P and layer thickness d, and KC with P and mean length of radial cracks. This work examines the accuracy and limitations of this approach using a wide range of contemporary dental ceramic materials. The effect of layer thickness, indenter radius, load level, and length and number of radial cracks are carefully examined. The accuracy of the predicted σF and KC is similar to those obtained with other concurrent test methods, such as biaxial flexure and 3-point bending (σF), and bending specimens with crack-initiation flaws (KC). The benefits of the present approach include treatment for small and thin plates, elimination of the need to introduce a precrack, and avoidance of dealing with local material nonlinearity effects for the KC measurements. Finally, the bilayer configuration resembles occlusal loading of a ceramic restoration (brittle layer) bonded to a posterior tooth (compliant substrate).

Enhanced thermally stable performance of Pr3+-doped vanadate phosphor by inhibiting the intervalence charge transfer quenching channel

Praseodymium (Pr3+) ion and the transition metal vanadium (V5+) ion with d0 electronic configuration can form an intervalence charge transfer (IVCT) band, which can function both as a compensatory channel for its red emission and as a quenching channel, thus affecting the luminescence thermal stability of the phosphors. Research studies reveal that the emission of Pr3+ in the YVO4 matrix can be quenched by the IVCT mechanism, thereby limiting the application of phosphors. As such, the present contribution is based on the solid solution replacement strategy to inhibit the constitutent of the IVCT quenching channel and thus improve thermal stability. Therefore, phosphonium (P5+) with a valence state matching V5+ and a similar ion radius was selected for the V/P substitution. It lacks a d0 electron configuration, preventing the formation of an IVCT band with Pr3+ and thereby inhibiting the construction of the quenching channels to enhance thermal stability. While the empirical formula of IVCT indicates a decrease in the IVCT energy level from 3.32438 to 3.06251 eV upon the introduction of P5+, the PLE spectra demonstrate a sharp reduction in IVCT intensity, i.e., weakening of the quenching channel. The thermal stability of the phosphors at different excitation locations was enhanced with the rise of P5+ concentration. When excited at the 3P2 level, the Y0.995PO4:0.5%Pr3+ phosphor demonstrated highly stable red emission from 303 to 523 K, with a luminescence integrated intensity ranging from 95.5% to 105.3% compared to that at 303 K. This research provides a novel approach for inhibiting the IVCT quenching channel and broadens the commercial value of YVO4:Pr3+ phosphor for various applications.

Using haematological indices to predict impaired liver function in DTC patients

OBJECTIVE

In patients with normal liver function, patients with acute or chronic thyroid disease are more likely to develop liver dysfunction. Although the mechanisms underlying this process are not yet fully understood, it has been shown that hypothyroidism can lead to hepatic injury. We evaluated haematological function trends in patients with differentiated thyroid cancer (DTC) at baseline and approximately 4 weeks after l-thyroxine withdrawal before radioactive iodine ablation.

SUBJECTS AND METHODS

This is a retrospective study, and 157 patients were enrolled. Logistic regression analysis was used to find significant predictors. Four weeks after LT4 withdrawal, 64 patients belonged to the group of liver injury, and 93 patients belonged to the group of normal liver function.

RESULTS

Univariate analysis determined that platelet count (PC) (P=0.005), mean platelet volume (MPV) (P=0.013), platelet distribution width (PDW) (P=0.039) and absolute lymphocyte count (ALC) (P=0.008) were responsible risk factors for liver injury in DTC patients after withdrawal of levothyroxine (l-thyroxine). Multivariate analysis showed that slight increases in PC (OR: 2.243, P: 0.024) and ALC (OR: 0.398, P: 0.017) were closely associated with liver injury in DTC patients after 4 weeks LT4 withdrawal before radioactive iodine ablation.

CONCLUSION

Our results suggest that PC and ALC are independent predictors of hypo-related liver injury. Our study is the first to suggest that haematological indices can be used for predicting the development and progression of hypo-related liver disorders.

Circ_0000467 modulates malignant characteristics of colorectal cancer via sponging miR-651-5p and up-regulating DNMT3B

Circular RNAs (circRNAs) are widely expressed in cancer tissues and participate in modulating the progression of malignant tumors, playing a pro- or anti-cancer role. This work is conducted to probe the precise role of circ_0000467 in colorectal cancer (CRC) and its regulatory mechanism. The differentially expressed circRNAs in CRC tissues and paracancerous tissues were screened by bioinformatics analysis. The expression levels of circ_0000467, miR-651-5p and DNA methyltransferases 3B (DNMT3B) mRNA in CRC tissues and cells were detected by qRT-PCR. circ_0000467 knockdown cell model was constructed to investigate the effects of circ_0000467 on CRC cell growth, migration and invasion by CCK-8 and Transwell experiments. Western blot was performed to examine DNMT3B protein expression in CRC cells. Dual-luciferase reporter gene experiment was executed to validate the targeting relationship between circ_0000467 and miR-651-5p, miR-651-5p and DNMT3B. Circ_0000467 expression and DNMT3B mRNA expression were increased and miR-651-5p expression was down-regulated in CRC tissues and cell lines. Knockdown of circ_0000467 repressed CRC cell growth, migration and invasion. Dual-luciferase reporter gene experiments validated that miR-651-5p was a direct target of circ_0000467 and miR-651-5p could specifically bind with DNMT3B 3'UTR. Functional compensation experiments showed that the regulatory effect of circ_0000467 on CRC cells' behaviors could be partially counteracted by miR-651-5p. Circ_0000467 may enhance the growth and metastasis of CRC cells by targeting miR-651-5p and up-regulating DNMT3B expression. Circ_0000467 may be a potential diagnostic biomarker and therapeutic target for CRC.

Multivariate morphometry statistics reveal the morphological change pattern of hippocampus during normal aging

There have been numerous studies focusing on normal aging in previous decades which is accompanied by the structural and functional decline in the hippocampus, while the pattern of hippocampal alteration with age remains unclear. Figuring out the mechanism of hippocampal changes precisely is beneficial for a better understanding of the aging process. In this study, we included a total of 451 T1 MRI scans of subjects of age 50-90 who were labeled as normal in the Alzheimer's Disease Neuroimaging Initiative. Taking 10 years of age as an age band, we divided the subjects into four groups (denoted as HC1, HC2, HC3, and HC4, respectively), with the youngest being 50-60 and the oldest 81-90. Then the Multivariate Morphometry Statistics (MMS) of the hippocampus segmented from the four groups were extracted by surface reconstruction, mesh generation, and surface registration. Finally, the significant differences between the youngest group and the other three were statistically analyzed. Results showed that the earliest deformation region of the left hippocampus located in the frontal subiculum and the dorsal CA1 of the tail part and gradually expanded with aging, while the right hippocampal deformation mainly concentrated in the dorsal CA1 and spread to the posterior CA2-3, which occurred later than that of the left. All the results illustrated that the hippocampus is truly a vulnerable structure in the course of aging, and the MMS are sensitive metrics for detecting the changes in the subcortical convex structure.

[A review of the influence of the 1956 Senior Teacher Training Program on Medical History]

The 1956 Senior Teacher Training Program on Medical History, hosted by the Institute of Traditional Chinese Medicine of the Ministry of Health, was the first teacher training program on the history of medicine in higher education in P. R. China. It was designed in the context of "Learning from the Soviet Union" for teaching reformation, "Integrating Western and Traditional Chinese Medicine" and performing the policy of "Blossom of Hundred Flowers and Contention of Hundred Schools of Thought" (by Mao Zedong for encouraging a variety of thinking conflicts) after the birth of the New China. The teaching management for the program was well organised, with a strong staff, and outcomes. A few of the trainees from this program were engaged in teaching and research of the history of medicine, and made outstanding academic achievements and promoted the teaching and research of the history of medicine in Chinese universities in the second half of the 20^th century. This program also provides a valuable reference for teacher training programs as well as teaching and research of medical history today.

Can Next-generation Sequencing Replace Fecal Immunochemical Tests or CT in the Screening of Colorectal Cancer and Advanced Adenoma?

OBJECTIVE

To explore the feasibility of next-generation sequencing (NGS) for the screening of colorectal cancer (CRC) and advanced adenoma (AA).

STUDY DESIGN

Observational study. Place and Duration of the Study: Renmin Hospital of Wuhan University, Wuhan, China, from June 2019 to February 2020.

METHODOLOGY

Patients who met inclusion and exclusion criteria were divided into three groups: CRC, AA, and control group. Then, the gene methylation status in the blood in the CRC, AA, and control group was analysed by NGS, and the CRC screening risk assessment model was used for comprehensive analysis. Afterwards, the methylated haplotype index (PHF Index) was calculated, and the screening results of the patients were classified as positive or negative, according to the score. The clinicopathological results were used as the gold standard, and the screening results for NGS were compared with the computed tomography (CT) and fecal immunochemical test (FIT) to text its feasibility.

RESULTS

NGS has a certain detection ability for CRC, with a sensitivity of 57.1% (8/14). This was higher than that of FIT and CT, and the combined positive rate of these three methods could reach 92.3% (12/13). The sensitivity of detection of AA could reach up to 75.0% (6/8) after combining with FIT and CT. The positive rate of the NGS test for postoperative CRC was 23.1% (3/13), which was significantly lower than preoperative CRC. The sensitivity of CT for preoperative CRC detection was only 45.5% (5/11), but the specificity could reach up to 98.2% (55/56), which was higher than NGS (71/78, 91.0%) and FIT (27/33, 81.8%).

CONCLUSION

Although NGS cannot replace FIT and CT at present, this provides a new effective and auxiliary detection method for people who are unsuitable or unwilling to receive colonoscopy. Key Words: Colorectal neoplasms, Adenoma, High-throughput nucleotide sequencing, Mass screening, Fecal immunochemical tests, Computed tomography.

An elephant trunk stent graft strayed into the false lumen leading to a death during the Sun's operation: A case report

Type A aortic dissection (AD) is a critical and severe disease with high mortality. The Sun's operation is a standard surgical method for this kind of disease at present. For the procedure, an elephant trunk stent is inserted into the true lumen of the descending aorta and the aortic arch is replaced. A patient was admitted to the First Hospital of Lanzhou University due to sudden chest and back pain for 6 days. Computed tomography angiography (CTA) showed type A AD. Ascending aorta replacement, Sun's operation, and ascending aorta to right femoral artery bypass grafting were performed. After surgery, the patient's condition was worsened. The digital subtraction angiography (DSA) showed the elephant trunk stent was inserted into the false lumen of AD, leading to the occlusion of the large blood vessel at the distal part of the abdominal aorta and below. Although we performed intima puncture and endovascular aortic repair, the patient was still dead.

Inhibition of BAMBI reduces the viability and motility of colon cancer via activating TGF-β/Smad pathway in vitro and in vivo

Colon cancer is a highly metastatic gastrointestinal cancer. BMP activin membrane-bound inhibitor (BAMBI), as a pseudo-receptor of the tumor growth factor (TGF)-β signal transduction pathway, has previously been demonstrated to be involved in human cancers. The present study demonstrated that BAMBI-small interfering (si)RNA regulated the viability and motility of colon cancer by activating TGF-β signaling. The expression level of BAMBI was suppressed by transfecting BAMBI-siRNA into the SW480 and HT-29 colon cancer cell lines. Decreased cell proliferation and increased cell apoptosis were detected in SW480 and HT-29 cells transfected with BAMBI-siRNA. Decreased expression of proliferation marker proteins Ki67 and proliferating cell nuclear antigen and elevated expression of apoptosis marker proteins (caspases-3, −8 and −9) further verified the role of BAMBI-siRNA in inhibiting cell viability. Silencing of BAMBI strongly reduced the closing rate and the number of invasive cells compared with control group. BAMBI-siRNA additionally resulted in decreased expression of migration marker proteins matrix metalloproteinase-9 (MMP-9), MMP-14 and vascular endothelial cell growth factor. In addition, the expression of TGF-β and phosphorylated-mothers against decapentaplegic homolog (Smad) 2/3 was increased in W480 and HT-29 cells transfected with BAMBI-siRNA. Elevated expression of the downstream signaling molecule E2F transcription factor 4/5 and suppressed c-MYC were additionally detected in the BAMBI-siRNA group. Finally, the in vivo experiment in the CSC xenograft revealed that BAMBI-siRNA strongly reduced the tumor growth and tumor volume. BAMBI-siRNA inhibited hepatic metastases and the expression of metastasis-associated proteins. The upregulated expression of TGF-β signaling proteins were detected in the BAMBI-siRNA group compared with control group in vivo. Overall, the results of the present study indicated that the inhibition of BAMBI reduces the viability and motility of colon cancer and may involve activation of the TGF-β/Smad pathway in vitro and in vivo.

Optimal threshold of stimulated serum thyroglobulin level for 18F-FDG PET/CT imaging in patients with thyroid cancer

This study was to explore the optimal threshold of thyroid-stimulating hormone (TSH)-stimulated serum thyroglobulin (s-Tg) for patients who were to receive ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT scan owing to clinical suspicion of differentiated thyroid cancer (DTC) recurrence but negative post-therapeutic ¹³¹I whole-body scan (¹³¹I-WBS). A total of 60 qualified patients underwent PET/CT scanning from October 2010 to July 2014. The receiver operating characteristic (ROC) curve analyses showed that s-Tg levels over 49 μg/L led to the highest diagnostic accuracy of PET/CT to detect recurrence, with a sensitivity of 89.5% and a specificity of 90.9%. Besides, bivariate correlation analysis showed positive correlation between s-Tg levels and the maximum standardized uptake values (SUVmax) of ¹⁸F-FDG in patients with positive PET/CT scanning, suggesting a significant influence of TSH both on Tg release and uptake of ¹⁸F-FDG. So, positive PET/CT imaging is expected when patients have negative ¹³¹I-WBS but s-Tg levels over 49 μg/L.

An evolution-based DNA-binding residue predictor using a dynamic query-driven learning scheme

DNA-binding proteins play a pivotal role in various biological activities. Identification of DNA-binding residues (DBRs) is of great importance for understanding the mechanism of gene regulations and chromatin remodeling. Most traditional computational methods usually construct their predictors on static non-redundant datasets. They excluded many homologous DNA-binding proteins so as to guarantee the generalization capability of their models. However, those ignored samples may potentially provide useful clues when studying protein-DNA interactions, which have not obtained enough attention. In view of this, we propose a novel method, namely DQPred-DBR, to fill the gap of DBR predictions. First, a large-scale extensible sample pool was compiled. Second, evolution-based features in the form of a relative position specific score matrix and covariant evolutionary conservation descriptors were used to encode the feature space. Third, a dynamic query-driven learning scheme was designed to make more use of proteins with known structure and functions. In comparison with a traditional static model, the introduction of dynamic models could obviously improve the prediction performance. Experimental results from the benchmark and independent datasets proved that our DQPred-DBR had promising generalization capability. It was capable of producing decent predictions and outperforms many state-of-the-art methods. For the convenience of academic use, our proposed method was also implemented as a web server at .

Diagnostic value of Tg and TgAb for metastasis following ablation in patients with differentiated thyroid carcinoma coexistent with Hashimoto thyroiditis

PURPOSE

This study was designed to investigate the clinical value of serum thyroglobulin (Tg) and antithyroglobulin antibody (TgAb) measurements and the cutoff value after ablation in differentiated thyroid carcinoma (DTC) complicated by Hashimoto thyroiditis (HT) with metastasis.

MATERIALS AND METHODS

We measured serum Tg and TgAb levels and evaluated the disease status in 164 cases of DTC coexistent with HT in pathologically confirmed patients after surgery and post-remnant ablation during a 3-year follow-up. All Tg and TgAb levels were assessed by chemiluminescent immunoassay (IMA). Receiver operating characteristic (ROC) curve analysis was used to evaluate the prognostic value of Tg and TgAb for disease metastasis. The relationship between Tg and TgAb was analyzed using the scatter diagram distribution method.

RESULTS

We found that the cutoff values of Tg and TgAb were 1.48 µg/L and 45 kIU/L, respectively. The area under the ROC curve (AUC) of Tg and TgAb was 0.907 and 0.650, respectively.

CONCLUSIONS

In DTC coexistent with HT patients, the optimal cutoff value correlated with metastasis in Tg and TgAb was 1.48 µg/L and 45 kIU/L, respectively.

Protein-protein interaction network construction for cancer using a new L1/2-penalized Net-SVM model

Identifying biomarker genes and characterizing interaction pathways with high-dimensional and low-sample size microarray data is a major challenge in computational biology. In this field, the construction of protein-protein interaction (PPI) networks using disease-related selected genes has garnered much attention. Support vector machines (SVMs) are commonly used to classify patients, and a number of useful tools such as lasso, elastic net, SCAD, or other regularization methods can be combined with SVM models to select genes that are related to a disease. In the current study, we propose a new Net-SVM model that is different from other SVM models as it is combined with L1/2-norm regularization, which has good performance with high-dimensional and low-sample size microarray data for cancer classification, gene selection, and PPI network construction. Both simulation studies and real data experiments demonstrated that our proposed method outperformed other regularization methods such as lasso, SCAD, and elastic net. In conclusion, our model may help to select fewer but more relevant genes, and can be used to construct simple and informative PPI networks that are highly relevant to cancer.

Nutritional State Predicts All-Cause Death Independent of Comorbidities in Geriatric Patients with Coronary Artery Disease

OBJECTIVE

To explore whether nutritional risk is associated with poor outcomes independent of complicated clinical status in older patients with coronary artery disease (CAD).

DESIGN

Cohort study.

SETTING

Patients referred for coronary angiography in West China Hospital, Sichuan University, China.

PARTICIPANTS

1772 patients with angiographic documented CAD whose age was above 65 years.

MEASUREMENTS

Nutritional state was appraised using geriatric nutritional risk index (GNRI). Nutritional risk was defined as the GNRI below 98. The event rate of all-cause death was observed among patients with nutritional risk and those without.

RESULTS

During a median follow-up period of 27 months, 224 patients died. Multivariate Cox regression analysis showed that nutritional risk was associated with all-cause death (adjusted hazard ratio 1.99; 95% confidence interval 1.35-2.95; P=0.001). Subgroup analysis verified the association between nutritional risk and death among patients with distinct clinical features, comorbidities, and medication. There was no interaction between nutritional risk and clinical characteristics with regard to all-cause death.

CONCLUSION

Nutritional state is independently associated with the risk of all-cause death in geriatric patients with CAD. Whether nutritional support in appropriate patients improves clinical outcomes deserves further investigation.

Increased interventricular septum wall thickness predicts all-cause death in patients with coronary artery disease

BACKGROUND

There is debate regarding the predictive value of interventricular septum (IVS) wall thickness for adverse events.

AIMS

The study investigated the association between the severity of thickened IVS and all-cause death in Chinese patients with coronary artery disease (CAD).

METHODS

A total of 2297 CAD patients verified by angiography was consecutively included. Patients were grouped according to the severity of thickened IVS. Cox regression analysis was conducted to determine the independent prognostic value of thickened IVS for all-cause death.

RESULTS

During a median follow up of 25 months, 149 patients died. A gradient increase in the risk of death was observed across thickened IVS groups. Compared to patients with normal IVS thickness, the adjusted hazard ratio (HR) was 1.49 (95% confidence interval (CI) 1.00-2.23, P = 0.05) and 2.13 (95% CI 1.29-3.54, P = 0.003) for all-cause death in those with mildly and moderately/severely thickened IVS respectively. For one unit increase in IVS thickness, the risk of all-cause death was elevated by 14% (adjusted HR 1.14, 95% CI 1.05-1.24, P = 0.003). In patients with normal indexed left ventricular mass, thickened IVS was also demonstrated as an independent risk factor for all-cause death.

CONCLUSION

Thickened IVS can be served as a reliable marker for predicting all-cause death in Chinese patients with CAD, even in those with normal left ventricular mass.

Lean mass index, body fat and survival in Chinese patients with coronary artery disease

BACKGROUND

'Obesity paradox' was not consistently observed in Asians with coronary artery disease (CAD).

AIM

The study investigated the association between body composition and outcomes in Chinese patients with CAD.

DESIGN

Cohort study.

METHOD

A total of 3280 patients with angiographically validated CAD were consecutively included. Body fat (BF) percentage and lean mass index (LMI) were evaluated using the Clínica Universidad de Navarra-Body Adiposity Estimator. The rate of mortality from any cause was compared across groups classified by the quartiles of LMI.

RESULTS

During a median period of 24 months, 288 (8.8%) participants died. There was a close association between increasing LMI and reducing mortality rate. However, univariate analyses did not find protective effect of BF on survival. After adjusting for age, sex, diabetes, current smoking, systolic blood pressure, creatinine, white blood cell count, haemoglobin and medication, Cox regression analyses showed that the significant relation between higher quartiles (Q) of LMI and survival benefit (Q4, hazard ratio 0.58 (95% confidence interval: 0.36-0.94) vs. Q3, 0.60 (0.39-0.91) vs. Q2, 0.60 (0.41-0.88) vs. Q1, reference) remained.

CONCLUSION

Low LMI but not BF predicts all-cause mortality in Chinese patients with CAD.

Efficacy of transcatheter aortic valve implantation in patients with aortic stenosis and reduced LVEF. A systematic review

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is safe and effective for patients with aortic stenosis (AS) who have a high operative risk. However, there is still debate on the effect of TAVI in AS patients with reduced left ventricular ejection fraction (REF). The objective of the review is to clarify the efficacy of TAVI and the impact of REF on the 30-day and midterm mortality in these patients.

METHODS

Studies on TAVI were searched in PubMed, Embase, and the Cochrane Library databases and were included in this review following predefined criteria. Data were extracted and pooled risk ratios (RR) were synthesized to explore the relationship between REF and 30-day plus midterm mortality.

RESULTS

Twenty-eight studies comprising 14,099 patients were included in the analysis of the association of REF with the prognosis of patients after TAVI. An average increase in left ventricular ejection fraction of 8-10 % was observed among these patients after TAVI. REF was not related to the 30-day mortality [RR = 1.90, 95 % confidence interval (CI) = 0.80-4.47]; however, it was related to the midterm mortality (RR = 1.49, 95 %CI = 1.14-1.93) of patients undergoing TAVI. Patients with low-flow and low-gradient AS had a higher 30-day mortality (RR = 1.54, 95 %CI = 1.11-2.13) and midterm mortality rate (RR = 1.69, 95 %CI = 1.33-2.14) compared with AS patients without these characteristics. The mortality of TAVI patients was significantly lower than that of those undergoing conservative therapy, and was similar to that of patients undergoing surgical aortic valve replacement.

CONCLUSION

REF was not associated with 30-day mortality, but it was associated with the midterm mortality of TAVI patients. Patients with REF could benefit from TAVI compared with conservative therapy.

Processing of facial expressions of emotions in healthy volunteers: an exploration with event-related potentials and personality traits

AIMS OF THE STUDY

Previous studies have shown that event-related potentials (ERPs) are modulated by anxiety or psychopathic personality traits. Therefore, we hypothesized that the automatic processing of facial expressions of emotions (FEE) is also correlated with related disordered personality traits.

METHODS

Thirty-seven healthy volunteers underwent both an "oddball" ERP recording to facial expressions of Anger, Happiness, Sadness, and Neutral, and a test of the Dimensional Assessment of Personality Pathology (DAPP).

RESULTS

Mean reaction time was longer in response to anger than to other facial expressions. Facial expressions of Anger, Happiness and Sadness did not affect N1 (N170). By contrast, Happiness elicited a delayed P2, Anger elicited both a smaller N2 and a delayed P3b, and both Happiness and Anger elicited a P3b of higher amplitude. In addition, P3a latencies to Happiness were negatively correlated with DAPP Identity problems, and P3b latencies to Happiness were negatively correlated with DAPP Stimulus seeking, Callousness, Passive aggressivity, and Narcissism.

CONCLUSION

Our study demonstrates that Anger implicitly captures attentional resources, and Happiness triggers more facilitated processing in individuals with dissocial traits.

Renal Myopericytoma: Case Report and Review of Literature

Myopericytoma arising in the visceral organs is rare and only 1 case of renal myopericytoma has been reported in the literature to date. We report the second case of myopericytoma arising in the kidney in a 40-year-old Hispanic woman who presented with pain on the left side of the abdomen and frequent urination. Abdominal computed tomography scan showed an exophytic left-sided renal mass. Partial nephrectomy was performed. The patient remains free of disease at 24 months after diagnosis. Our case is histologically distinct from the previously described case as it lacks the “hemangiopericytic/glomangiopericytoma” pattern. The tumor in our case showed the characteristic pattern of myopericytoma and an additional glomus tumorlike pattern. The tumor cells showed diffuse reactivity for vimentin, smooth muscle actin, smooth muscle myosin heavy chain, and muscle-specific actin in both morphologic patterns and strong diffuse CD34 expression in glomus tumorlike focus. This case report adds to the morphologic heterogeneity of myopericytomas.

Lysophosphatidic acid causes endothelial dysfunction in porcine coronary arteries and human coronary artery endothelial cells

AIM

The objective of this study was to determine the effects of lysophosphatidic acid (LPA) on endothelial functions and molecular alternations in both porcine coronary arteries and human coronary artery endothelial cells (HCAECs).

METHODS AND RESULTS

The vessel rings and HCAECs were treated with clinically relevant concentrations of LPA for different times. Vasomotor reactivity was studied with a myograph tension system. LPA (10 and 50 μM) treatment for the vessel rings significantly reduced endothelium-dependent vasorelaxation in response to bradykinin (×10(-5)M) by 32% and 49%, respectively, compared with the control (P<0.05). LPA decreased endothelial nitric oxide synthase (eNOS) mRNA and immunoreactivity levels in the vessel rings. In HCAECs, LPA reduced eNOS mRNA, phospho-eNOS and total eNOS protein levels. In addition, superoxide anion levels in LPA-treated vessel rings and HCAECs were significantly increased by lucegenin-enhanced chemiluminescence assay and dihydroethidium staining, respectively. Mitochondrial membrane potential and ATP content in LPA-treated HCAECs were substantially decreased. The mRNA levels of reactive oxygen species generating enzymes NOX4 and p40(phox) were increased, while endogenous antioxidant enzyme superoxide dismutase 1 was decreased in response to LPA treatment in HCAECs. Furthermore, exogenous antioxidant molecule selenomethionine (SeMet) effectively reversed these LPA-induced effects in both porcine coronary arteries and HCAECs.

CONCLUSIONS

LPA causes endothelial dysfunction by a mechanism associated with decreased eNOS expression and increased oxidative stress in porcine coronary arteries and HCAECs.

Chipping resistance of graded zirconia ceramics for dental crowns

A serious drawback of veneering porcelains is a pronounced susceptibility to chipping. Glass-infiltrated dense zirconia structures can now be produced with esthetic quality, making them an attractive alternative. In this study, we examined the hypothesis that such infiltrated structures are much more chip-resistant than conventional porcelains, and at least as chip-resistant as non-infiltrated zirconia. A sharp indenter was used to produce chips in flat and anatomically correct glass-infiltrated zirconia crown materials, and critical loads were measured as a function of distance from the specimen edge (flat) or side wall (crown). Control data were obtained on zirconia specimens without infiltration and on crowns veneered with porcelains. The results confirmed that the resistance to chipping in graded zirconia is more than 4 times higher than that of porcelain-veneered zirconia and is at least as high as that of non-veneered zirconia.

2,6-Dibromo-4-(2-hy-droxy-eth-yl)phenol

The title compound, C₈H₈Br₂O₂, crystallized with two independent mol­ecules (A and B) in the asymmetric unit. They differ in the conformation of the 2-hy­droxy­ethyl chain with the C—C—C—O torsion angle being −68.0 (12)° in mol­ecule A and 172.2 (9)° in mol­ecule B. In the crystal, the A mol­ecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers, while the B mol­ecules are linked via an O—H⋯O hydrogen bond, forming a polymeric chain propagating in [010]. In addition, there are O—H⋯O and O—H⋯Br hydrogen bonds, and Br⋯Br [3.599 (2) Å] and π–π inter­actions [centroid–centroid distances = 3.581 (6) and 3.931 (6) Å], leading to the formation of a two-dimensional network parallel to (001).

Therapeutic potential for protein kinase C inhibitor in vascular restenosis

Vascular restenosis, an overreaction of biological response to injury, is initialized by thrombosis and inflammation. This response is characterized by increased smooth muscle cell migration and proliferation. Available pharmacological treatments include anticoagulants, antiplatelet agents, immunosuppressants, and antiproliferation agents. Protein kinase C (PKC), a large family of serine/threonine kinases, has been shown to participate in various pathological stages of restenosis. Consequently, PKC inhibitors are expected to exert a wide range of pharmacological activities therapeutically beneficial for restenosis. In this review, the roles of PKC isozymes in platelets, leukocytes, endothelial cells, and smooth muscle cells are discussed, with emphasis given to smooth muscle cells. We will describe cellular and animal studies assessing prevention of restenosis with PKC inhibitors, particularly targeting -α, -β, -δ, and -ζ isozymes. The delivery strategy, efficacy, and safety of such PKC regulators will also be discussed.

Resistin decreases expression of endothelial nitric oxide synthase through oxidative stress in human coronary artery endothelial cells

Resistin is a newly discovered adipocyte-derived cytokine that may play an important role in insulin resistance, diabetes, adipogenesis, inflammation, and cardiovascular disease. However, it is largely unknown whether resistin impairs endothelial functions by affecting the endothelial nitric oxide synthase (eNOS) system. In this study, we determined the effect of human recombinant resistin protein on eNOS expression and regulation in human coronary artery endothelial cells (HCAECs). When cells were treated with clinically relevant concentrations of resistin (40 or 80 ng/ml) for 24 h, the levels of eNOS mRNA, protein, and activity and eNOS mRNA stability were significantly reduced. Cellular nitric oxide levels were also decreased. In addition, the cellular levels of reactive oxygen species (ROS), including superoxide anion, were significantly increased in resistin-treated HCAECs. Mitochondrial membrane potential and the activities of catalase and superoxide dismutase were reduced. Three antioxidants, seleno-L-methionine, ginsenoside Rb1, and MnTBAP (superoxide dismutase mimetic), effectively blocked resistin-induced eNOS downregulation. Meanwhile, resistin activated the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase (JNK), and the specific p38 inhibitor SB-239063 effectively blocked resistin-induced ROS production and eNOS downregulation. Furthermore, immunoreactivity of resistin was increased in atherosclerotic regions of human aorta and carotid arteries. Thus resistin directly induces eNOS downregulation through overproduction of ROS and activation of p38 and JNK in HCAECs. Resistin-induced mitochondrial dysfunction and imbalance in cellular redox enzymes may be the underlying mechanisms of oxidative stress.

Sorafenib downregulates ERK/Akt and STAT3 survival pathways and induces apoptosis in a human neuroblastoma cell line

Neuroblastoma is a common solid tumor in children and its tumorigenicity is enhanced by the expression of survival pathways such as Akt and signal transducer and activator of transcription 3 (STAT3). Sorafenib is a multikinase inhibitor that also inhibits STAT3 signaling and induces apoptosis. In this study, we will examine the efficacy of sorafenib on a human neuroblastoma cell line (SK-N-AS) and also investigate its possible mechanisms. After cells reached 50-60% confluence, they were treated with various concentrations of sorafenib (0, 0.1, 1, 5, 10 and 20 microM) for different periods of time. The cell viability and apoptosis were determined by MTS colorimetric assay and TUNEL, respectively. Phosphorylation of Akt1/2/3 (p-Akt1/2/3), extracellular signal-regulated kinase 1/2 (p-ERK1/2), STAT3 (p-STAT3), and AMP-activated protein kinase alpha subunit (p-AMPKalpha) were determined with Western blot. The results indicate that as early as 2 hours post-treatment, cell viability was significantly decreased at 10 microM concentration. In 24 hours or longer treatment groups, sorafenib at 5 microM and above significantly decreased cell viability. TUNEL assay showed a significant increased of apoptosis in 5 and 20 microM treatment groups 24 hours after treatment. Western blots showed a decrease of p-ERK1/2, p-Akt1/2/3, p-STAT3, and p-AMPKalpha expression levels in various sorafenib treatment groups. Our results indicate that sorafenib significantly decreased cell viability and increased apoptosis in human neuroblastoma cell line in association with down-regulation of p-ERK1/2, p-Akt, p-STAT3 survival pathways. These data suggested potential clinical application of sorafenib in the treatment of neuroblastoma.

Graded structures for all-ceramic restorations

One failure mode of all-ceramic restorations is radial cracking at the cementation surface, from occlusally induced flexure of the stiffer ceramic layer(s) on the softer dentin underlayer. We hypothesize that such failure may be substantially mitigated by an appropriate grading of elastic modulus through the ceramic thickness. In this study, we fabricated graded structures by infiltrating glass into zirconia plates, with resulting diminished modulus in the outer surfaces. The plates were then bonded to a polymeric base and subjected to flexure by contact loading until fracture. Comparison of infiltrated specimens with non-infiltrated controls showed a significant increase in the fracture loads, by a factor of nearly 2. Finite element analysis revealed the cause of increase in the load-bearing capacity to be diminished tensile stresses within the lower-modulus graded zone, corresponding to an increase in material strength. The results confirmed that suitably graded structures can be highly beneficial in the design of next-generation all-ceramic restorations.

Discrimination and classification of tobacco wastes by identification and quantification of polyphenols with LC-MS/MS

The chemical composition of polyphenols in tobacco waste was identified by HPLC-PAD-ESI/MS/MS and the contents of chlorogenic acids and rutin in 10 varieties of tobacco wastes were determined by HPLC-UV. The relationships between the contents of active polyphenols and the varieties of tobacco wastes were interpreted by hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results showed that 15 polyphenols were identified in a methanolic extract of dried tobacco waste. The tobacco wastes were characterized by high levels of chlorogenic acids (3-CQA, 5-CQA, and 4-CQA) and rutin; their ranges in the 10 tobacco varieties were 0.116-0.196, 0.686-1.781, 0.094- 0.192, and 0.413-0.998 %, respectively. According to multivariate statistics models, two active compound variables can be considered important for the discrimination of the varieties of tobacco wastes: chlorogenic acids and rutin. Consequently, samples of 10 tobacco varieties were characterized into three groups by HCA based on the PCA pattern. In conclusion, tobacco waste could be used as a new pharmaceutical material for the production of natural chlorogenic acids and rutin in the ethnopharmacological industry.

[Prognostic impact of heart block during transcatheter closure of ventricular septal defect]

OBJECTIVE

To investigate the prognostic impact of heart block during the transcatheter closure of ventricular septal defect (VSD).

METHODS

Forty three patients developed complete left or right bundle branch block (CLBBB, CRBBB), incomplete left or right bundle branch block (ILBBB, IRBBB), and atrioventricular block (AVB) during and within 1 week post procedure were followuped at 1, 6, 12, 24, 36, 48 and 60 months post procedure. Electrocardiogram, dynamic electrocardiogram and transthoracic echocardiography were made.

RESULTS

Bundle branch block and atrioventricular block were detected in 26 patients (CLBBB n = 4, CRBBB n = 5, ILBBB n = 2, IRBBB n = 10 and third-degree AVB n = 5) during the transcatheter closure of VSD, and in 17 patients (CLBBB n = 5, CRBBB n = 2, first-degree AVB n = 3, second-degree I-type AVB n = 1 and third-degree AVB n = 6) within 1 week post procedure. Heart block disappeared in 33 patients (76.7%) before discharge, in 37 patients (86.1%) at 1 month and in 41 patients (95.4%) at 6 months post procedure. CLBBB or CRBBB was seen in two cases at 24 months after closure. There was no heart failure and serious cardiac dilatation during follow up.

CONCLUSION

The heart block occurred during the periprocedure period of transcatheter closure of VSD was a benign phenomenon without prognostic importance.

Lactosylceramide causes endothelial dysfunction in porcine coronary arteries and human coronary artery endothelial cells

BACKGROUND

Lactosylceramide (LacCer) is a member of the glycosphingolipid family, which has been implicated in the atherogenic process. The goal of this study was to determine the effects and molecular mechanisms of LacCer on endothelial functions in porcine coronary arteries and human coronary endothelial cells (HCAECs).

MATERIAL/METHODS

The vessel rings and HCAECs were treated with different concentrations of LacCer for 24 hours. Vasomotor function was studied using a myograph tension system in response to thromboxane A2 analog U46619, bradykinin and sodium nitroprusside (SNP). Superoxide anion production was determined using lucigenin-enhanced chemiluminescence. The expression of endothelial nitric oxide synthase (eNOS), NADPH oxidase subunit NOX4 and catalase was determined by real-time PCR.

RESULTS

LacCer (0.1, 1 and 10 microM) significantly decreased endothelium-dependent vasorelaxation (bradykinin) in porcine coronary artery rings in a concentration-dependent manner compared with untreated controls (P<0.05). High concentration of LacCer (10 microM) also reduced endothelium-independent vasorelaxation (SNP). However, LacCer did not affect vessel contraction (U46619). Antioxidant selenomethionine (SeMet) effectively reversed LacCer-induced endothelial dysfunction in the vessel rings. Furthermore, LacCer significantly increased superoxide anion production in the vessel rings in a concentration-dependent manner compared with untreated controls (P<0.05). In response to LacCer treatment, NOX4 mRNA levels were significantly increased, while the expression of catalase and eNOS was significantly decreased in HCAECs compared with controls (P<0.05).

CONCLUSIONS

LacCer causes endothelial dysfunction with potential mechanisms of the down-regulation of eNOS and increase of oxidative stress due to the activation of NADPH oxidase and inhibition of internal antioxidant catalase. This study suggests that LacCer may represent a risk factor to the vascular system and antioxidant SeMet may have clinical applications for prevention of vascular disease.

Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells

AIMS

Clinically, Chlamydia pneumoniae infection and its heat shock protein 60 (cHSP60) may contribute to atherogenesis; however, its underlying mechanisms are largely unknown. The objective of this study was to determine whether cHSP60 could cause endothelial dysfunction in human coronary artery endothelial cells (HCAECs) and porcine coronary arteries.

METHODS AND RESULTS

When HCAECs were treated with recombinant cHSP60, endothelial nitric oxide synthase (eNOS) mRNA and protein levels, enzyme activities, cellular NO levels, mRNA stability, and promoter activities were significantly decreased. Superoxide anion production was significantly increased due to the inhibition of mitochondrial membrane potential and catalase and superoxide dismutase (SOD) activities as well as activation of NADPH oxidase. Antioxidant seleno-l-methionine (SeMet) or SOD mimetic MnTBAP effectively blocked cHSP60-induced eNOS downregulation. In addition, cHSP60 activated mitogen-activated protein kinases (MAPKs) including p38, c-Jun-N-terminal kinase/stress-activated protein kinase, and extracellular signal-regulated kinases. Specific chemical inhibitors or their dominant-negative mutant forms of these MAPKs effectively blocked cHSP60-induced eNOS downregulation. cHSP60-induced eNOS downregulation and oxidative stress were also demonstrated in porcine coronary artery rings in vitro. Functionally, endothelium-dependent vasorelaxation was significantly reduced in cHSP60-treated vessels.

CONCLUSION

cHSP60 directly induces eNOS downregulation through oxidative stress and MAPK activation in both HCAECs and porcine coronary arteries, thereby causing endothelial dysfunction.

Fracture Modes in Human Teeth

The structural integrity of teeth under stress is vital to functional longevity. We tested the hypothesis that this integrity is limited by fracture of the enamel. Experiments were conducted on molar teeth, with a metal rod loaded onto individual cusps. Fracture during testing was tracked with a video camera. Two longitudinal modes of cracking were observed: median cracking from the contact zone, and margin cracking along side walls. Median cracks initiated from plastic damage at the contact site, at first growing slowly and then accelerating to the tooth margin. Margin cracks appeared to originate from the cemento-enamel junction, and traversed the tooth wall adjacent to the loaded cusp from the gingival to the occlusal surface. All cracks remained confined within the enamel shell up to about 550 N. At higher loads, additional crack modes—such as enamel chipping and delamination—began to manifest themselves, leading to more comprehensive failure of the tooth structure.

Roles and mechanisms of human immunodeficiency virus protease inhibitor ritonavir and other anti-human immunodeficiency virus drugs in endothelial dysfunction of porcine pulmonary arteries and human pulmonary artery endothelial cells

The objective of this study was to determine the effects of highly active antiretroviral therapy (HAART) drugs on pulmonary endothelial function. Porcine pulmonary arteries or human pulmonary arterial endothelial cells (HPAECs) were incubated with eight HAART drugs [ritonavir, indinavir, lopinavir, zidovudine (AZT), abacavir, stavudine, didanosine (ddI), and lamivudine] individually or in combination [three HAART drugs (3-plex; indinavir, stavudine, and ddI)] at their clinical plasma concentrations for 24 hours. Endothelium-dependent vasorelaxation in response to bradykinin was reduced significantly by the ritonavir in a concentration-dependent manner. Five other HAART drugs (indinavir, lamivudine, abacavir, AZT, and ddI) and the 3-plex significantly also impaired endothelium-dependent vasorelaxation in response to bradykinin. Five HAART drugs (ritonavir, indinavir, lamivudine, abacavir, and AZT) significantly decreased endothelial nitric oxide synthase (eNOS) expression and increased superoxide anion levels in both vessels and HPAECs. Furthermore, both ritonavir and AZT substantially activated ERK2 in HPAECs. Additionally, the antioxidants ginsenoside Rb1 and ginkgolide A effectively reversed HAART drug-induced vasomotor dysfunction and eNOS down-regulation. Inhibition of ERK1/2 also partially blocked ritonavir- and AZT-induced down-regulation of eNOS and vasomotor dysfunction. Thus, HAART drugs significantly impair endothelial functions of porcine pulmonary arteries and HPAECs, which may be mediated by eNOS down-regulation, oxidative stress, and ERK1/2 activation. These findings suggest that HAART drugs may contribute to the high incidence of pulmonary artery hypertension in human immunodeficiency virus-infected patients.

Field effect in cancer-an update

The concept "field effect in cancer" originated in 1953 from the histopathological observations of Slaughter and colleagues [1] regarding the occurrence of multiple primary oral squamous cell carcinomas and their local recurrences. The development of modern molecular technologies has extended the field effect concept by exploring the molecular abnormalities in tissues that appear histologically normal. To date, such field effect biomarkers have been reported in several sites and organs, eg, head and neck, colon and rectum, prostate, breast, lung, esophagus, stomach, and skin. Two popular hypotheses have been proposed. One hypothesis implicates genetic alterations that occur in a stepwise fashion (initiation, promotion, and progression); a clone gains growth advantage and acquires more genetic alterations, which eventually result in cancer. A second hypothesis focuses on epigenetic alterations, which include hypermethylation of the DNA promoter of certain tumor suppressor genes, leading to down-regulation of these genes. In this update, we discuss in detail the evidence that supports these two hypotheses. In addition, we attempt to provide a comprehensive overview of the field effect in carcinogenesis and its possible mechanisms in various organs. Moreover, we discuss the potential utilization of field effect biomarkers in cancer prevention, surgical considerations, and clinical prognosis.