Antiproliferative activity of three methoxylated flavonoids isolated from Zeyheria montana Mart. (Bignoniaceae) leaves

The present study isolated three major active flavonoids, two flavones named 4',5,7-trimethoxy-luteolin (1) and 6-hydroxy-5,7-dimethoxyflavone (2) and the flavanone 5-hydroxy-6,7-dimethoxyflavanone (3) from Zeyheria montana dichloromethane leaf extract. Isolation and purification were conducted with the application of column chromatography and structures were assigned by spectral analysis. All compounds were evaluated for cytotoxic activities against human tumor cell lines UACC-62 (melanoma), MCF-7 (breast), NCI-ADR/RES (breast expressing phenotype multiple drug resistance), 786-0 (renal), NCI-H460 (lung, non-small cells), PC-3 (prostate), OVCAR-3 (ovarian), HT-29 (colon) and K562 (leukemia) in vitro. All compounds were active in different degrees on several tumor cell lines and flavanone 3 showed cytotoxicity against almost all cell lines, particularly against human NCI-ADR/RES and K562 cell lines. In conclusion, three antiproliferative compounds were isolated for the first time from Zeyheria montana and its leaves were characterized as an important source of methoxylated flavones and flavanone as potential antitumor compounds.     

Sida cordifolia leaf extract reduces the orofacial nociceptive response in mice

In this study, we describe the antinociceptive activity of the ethanol extract (EE), chloroform (CF) and methanol (MF) fractions obtained from Sida cordifolia, popularly known in Brazil as "malva branca" or "malva branca sedosa". Leaves of S. cordifolia were used to produce the crude ethanol extract and after CF and MF. Experiments were conducted on Swiss mice using the glutamate and formalin-induced orofacial nociception. In the formalin test, all doses of EE, CF and MF significantly reduced the orofacial nociception in the first (p < 0.001) and second phase (p < 0.001), which was also naloxone-sensitive. In the glutamate-induced nociception test, only CF and MF significantly reduced the orofacial nociceptive behavior with inhibition percentage values of 48.1% (100 mg/kg, CF), 56.1% (200 mg/kg, CF), 66.4% (400 mg/kg, CF), 48.2 (200 mg/kg, MF) and 60.1 (400 mg/kg, MF). Furthermore, treatment of the animals with EE, CF and MF was not able to promote motor activity changes. These data demonstrate that S. cordifolia has a pronounced antinociceptive activity on orofacial nociception. However, pharmacological and chemical studies are necessary in order to characterize the responsible mechanisms for this antinociceptive action and also to identify other bioactive compounds present in S. cordifolia.     

Association of -308 TNF-α promoter polymorphism with clinical aggressiveness in patients with head and neck squamous cell carcinoma

Genetic polymorphisms in the promoter region of the tumour necrosis factor-α (TNF-α) gene are involved in the regulation of the expression levels of its cytokine. Besides, these polymorphisms have been associated with the clinical behaviour of cancer. We investigated the −308 promoter region polymorphisms of the TNF-α gene and its association with the clinicopathological factors of a head and neck squamous cell carcinoma (HNSCC) sample. Furthermore, we analysed the impact of all the variables on the overall survival of patients. A sample of HNSCC (n = 89) was evaluated. Clinicopathological factors and overall survival data were gathered. The TNF-α gene was analysed by using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). Data analyses were performed by using bivariate and multivariate statistical tests. Significance was set at p < 0.05. HNSCC subjects carrying the A allele (GA/AA) exhibited associations with poor performance status (OR = 2.82, p = 0.039), lesions located on posterior areas (OR = 4.02, p = 0.002), and large-size tumours (OR = 2.91, p = 0.015). Subjects carrying only AA genotype exhibited association with poor performance status (OR = 6.667, p = 0.007). A worse overall survival was noted in subjects with large tumours (OR = 4.87, p = 0.005) and locoregional metastatic disease (OR = 2.50, p = 0.018). Our data suggests that the presence of the A allele/AA haplotype in HNSCC individuals might contribute to the higher clinical aggressiveness of malignant disease.     

Oral squamous cell carcinoma versus oral verrucous carcinoma: an approach to cellular proliferation and negative relation to human papillomavirus (HPV)

Human papillomavirus (HPV) has been cited as a possible initiating agent in the pathogenesis of oral cancer. However, the literature tends to be both controversial and inconclusive about the prevalence of HPV and its potential for proliferation in oral squamous cell carcinoma (SCC). The aim of this study was to investigate the cellular proliferation and the presence of HPV in SCC and verrucous carcinoma (VC). Forty-seven samples of SCC were selected and divided into three groups: 39 SCC, 8 VC, and 9 of normal mucosa (control-CT). Quantitative analyses of all groups showed a greater expression of PCNA, followed by Ki-67 and cyclin B1. A significant difference was observed in cyclin B1 expression in the SCC group compared with VC. PCNA, Ki-67, and cyclin B1 were statistically significant when comparing the SCC and CT groups. However, when SCC and VC were compared, there was no difference in Ki-67 expression. Our results showed that only cyclin B1 had an association with histological grade, and that poorly differentiated tumors presented a higher expression of cyclin B1. Therefore, considerable differences in the cellular proliferation between SCC and VC were observed, and no correlation with HPV was established, since all samples were negative for HPV.     

RNA expression of the molecular signature genes for metastasis in colorectal cancer

Colorectal cancer is an endemic disease in the western world. Search for molecular signatures present in primary tumors that predict tumor metastasis potential has been proposed and in particular, a 17-gene molecular signature is associated with poor survival in breast cancer, prostate cancer, meduloblastoma and lymphoma in a recent study. Using quantitative real-time PCR assay (qPCR), our study observed tumor-normal differential RNA expression in 15 of these 17 genes in a cohort of 52 stage III colorectal cancer patients (all p<0.05), which signified the importance of these 17 signature genes in colorectal cancer. Although no significant correlation was found between tumor RNA levels of these 17 genes and some of clinical features (age, gender, and location, all p>0.05), two distinct groups among these genes were observed with Spearman correlation scores>0.6 (p<0.01), suggesting co-expression/interaction within these genes. Of the 37 patients for whom complete follow-up data was available, 12 patients had recurrence and 25 had no recurrence. There was no significant difference in tumor RNA levels between recurrence and non-recurrence groups for the 17 genes (all p>0.05), but the recurrence group had more patients with mucinous tumors (9/12 vs. 7/25, p<0.05) and more lymph node involvement (median 7.2 vs. 2.5, p<0.05) compared to the non-recurrence group. Moreover, survival analysis revealed a significant difference in patient overall survival time between low and high tumor RNA levels for 1 of the 17 genes (PTTG1, p=0.024). Our qPCR validation study confirms the importance of most 17-gene molecular signature genes with differential RNA expression and suggests the relevance of PTTG1 for survival in colorectal cancers.     

Phenotypic changes in a laboratory-derived ertapenem-resistant Escherichia coli strain

The aim of this study was to identify phenotypic changes in a laboratory-derived strain of ertapenem-resistant Escherichia coli (Ec-ERT) when compared to its susceptible parent strain (Ec-WT). In both strains, we assessed both the effects of ertapenem via time-kill curves and the occurrence of cross resistance with other beta-lactams. The strains were compared based on growth pattern, biochemical-physiological profile and changes in the subproteome using 2D-DIGE followed by MALDI-TOF/TOF MS. To assess virulence, we employed a murine model of intraperitoneal infection in which we investigated the invasiveness of both strains. Growth persistence of the laboratory-derived resistant strain was observed via the time-kill curve assay, but cross resistance was not observed for other beta-lactams. We also observed a slower growth rate and changes in the biochemical and physiological characteristics of the drug-resistant bacteria. In the resistant strain, a total of 51 protein spots were increased in abundance relative to the wild-type strain, including an outer membrane protein A, which is related to bacterial virulence. The mouse infection assay showed a higher invasiveness of the Ec-ERT strain in relation to the Ec-WT strain. In conclusion, the alterations driven by ertapenem in E. coli reinforce the idea that antimicrobial agents may interfere in several aspects of bacterial cell biology, with possible implications for host-bacteria interactions.     

Synthesis and biocompatibility of an experimental glass ionomer cement prepared by a non-hydrolytic sol-gel method

The aims of this study were to demonstrate the synthesis of an experimental glass ionomer cement (GIC) by the non-hydrolytic sol-gel method and to evaluate its biocompatibility in comparison to a conventional glass ionomer cement (Vidrion R). Four polyethylene tubes containing the tested cements were implanted in the dorsal region of 15 rats, as follows: GI - experimental GIC and GII - conventional GIC. The external tube walls was considered the control group (CG). The rats were sacrificed 7, 21 and 42 days after implant placement for histopathological analysis. A four-point (I-IV) scoring system was used to graduate the inflammatory reaction. Regarding the experimental GIC sintherization, thermogravimetric and x-ray diffraction analysis demonstrated vitreous material formation at 110oC by the sol-gel method. For biocompatibility test, results showed a moderate chronic inflammatory reaction for GI (III), severe for GII (IV) and mild for CG (II) at 7 days. After 21 days, GI presented a mild reaction (II); GII, moderate (III) and CG, mild (II). At 42 days, GI showed a mild/absent inflammatory reaction (II to I), similar to GII (II to I). CG presented absence of chronic inflammatory reaction (I). It was concluded that the experimental GIC presented mild/absent tissue reaction after 42 days, being biocompatible when tested in the connective tissue of rats.     

The 434(G>C) polymorphism in the eosinophil cationic protein gene and its association with tissue eosinophilia in oral squamous cell carcinomas

J Oral Pathol Med (2010) 39 : 56–62
Objective:  The aim of this study was to investigate the prevalence of the Eosinophil cationic protein (ECP)-gene polymorphism 434(G>C) in oral squamous cell carcinoma (OSCC) patients and its association with tumor-associated tissue eosinophilia (TATE), demographic, clinical, and microscopic variables.
Methods:  The ECP genotypes of 165 healthy individuals and 157 OSCC patients were detected by PCR-RFLP analysis after cleavage of the amplified DNA sequence with enzyme Ps tI. TATE was obtained by morphometric analysis. Chi-square test or Fisher's exact test was used to analyze the association of ECP-gene polymorphism 434(G>C) with TATE, demographic, clinical, and microscopic variables in OSCC patients. Disease-free survival and overall survival were calculated by the Kaplan–Meier product-limit actuarial method and the comparison of the survival curves were performed using log rank test.
Results:  Most of healthy individuals (53.33%) and OSCC patients (57.97%) were heterozygous for the ECP 434(G>C) polymorphism. Based on numerical differences, our results showed that OSCC patients with intense TATE and at least one C allele had a higher frequency of bilateral neck dissection, local recurrence, vascular embolization, involved resection margins, and postoperative radiotherapy. No statistically significant differences on survival rates were found in OSCC patients presenting different ECP 434(G>C) genotypes.
Conclusions:  These results suggest a tendency towards a poor clinical outcome in OSCC patients with intense TATE and 434GC/CC genotypes, probably due to an ECP genetic variant with altered cytotoxic activity.     

Influence of Cusp Inclination on Stress Distribution in Implant‐Supported Prostheses. A Three‐Dimensional Finite Element Analysis

Purpose: The aim of this study was to assess the influence of cusp inclination on stress distribution in implant‐supported prostheses by 3D finite element method. Materials and Methods: Three‐dimensional models were created to simulate a mandibular bone section with an implant (3.75 mm diameter × 10 mm length) and crown by means of a 3D scanner and 3D CAD software. A screw‐retained single crown was simulated using three cusp inclinations (10°, 20°, 30°). The 3D models (model 10d, model 20d, and model 30d) were transferred to the finite element program NeiNastran 9.0 to generate a mesh and perform the stress analysis. An oblique load of 200 N was applied on the internal vestibular face of the metal ceramic crown. Results: The results were visualized by means of von Mises stress maps. Maximum stress concentration was located at the point of application. The implant showed higher stress values in model 30d (160.68 MPa). Cortical bone showed higher stress values in model 10d (28.23 MPa). Conclusion: Stresses on the implant and implant/abutment interface increased with increasing cusp inclination, and stresses on the cortical bone decreased with increasing cusp inclination.