Dentin Exposure after Tooth Preparation for Laminate Veneers: A Microscopical Analysis to Evaluate the Influence of Operators’ Expertise

Background: To assess the quantity of dentin exposure detected by 3 operators with different clinical expertise for 2 designs of tooth preparation for laminate veneers: window (WI) and butt joint (BJ). Methods: 20 intact maxillary central incisors were collected and then prepared for laminate veneers to a depth of 0.6 mm, with a cervical mini-chamfer finish line of 0.3 mm. Each prepared tooth was analyzed by 3 operators with different expertise: undergraduate student (ST), general practitioner (GP), and prosthodontist (PR), at sight under magnification. Besides descriptive statistics (CI 95%), 2-way ANOVA and Games–Howell tests were used to analyze differences among groups (α = 0.05). Results: The means of percentage and area of detected dentin exposure were WI = 30.48%, 21.57 mm2; BJ = 30.99%, 21.97 mm2; ST/WI = 22.82%, 16.44 mm2; GP/WI = 58.05%, 40.64 mm2; PR/WI = 10.55%, 7.63 mm2; ST/BJ = 28.99%, 20.83 mm2; GP/BJ = 40.56%, 28.32 mm2; PR/BJ = 23.42%, 16.75 mm2. Significant differences were found between ST/WI vs. GP/WI (p = 0.005) and GP/WI vs. PR/WI (p < 0.001). Conclusions: There was no difference in detection of exposed dentin among operators with different expertise for BJ preparation, whereas differences were found between the general practitioner and the other 2 operators in WI. Moreover, the quantity of exposed dentin was not related to different tooth preparation designs

Effects of the combined action of a desensitizing gel and toothpaste on dentin hypersensitivity due to dental bleaching

Objectives: The present study is aimed at evaluating the effectiveness of a fluoride- and potassium nitrate-containing gel and toothpaste in reducing dentinal hypersensitivity due to dental bleaching. Materials and methods: Specific inclusion and exclusion criteria were used to recruit patients for the study. They were randomly allocated to a test or a placebo control group. Patients underwent a treatment of home dental bleaching with 10% carbamide peroxide. Dental shades were evaluated in a standardized environment and dentinal hypersensitivity was valuated by means of evaporation stimuli. A nominal scale was used to score the painful reaction. The patients were recalled 8, 15 and 28 days after the baseline for both shade and sensitivity assessment. Statistical analysis was performed using the Student’s T-test. Results: The patients recall rate was 96.9%. The statistical analysis demonstrated a significant reduction of the painful symptoms in the experimental group (p=0.031) while no statistically significant differences were evidenced in the control group at any follow-up recall (p>0.05). Discussion: The tested agents proved to be safe and effective in the short term. Neither pigmentations nor interferences with the bleaching action of peroxides due to the desensitizing agents were observed. The compliance of the patients to the proposed protocol as well as the motivation to maintain good oral hygiene were paramount in the achievement of the reported results. Conclusions: The use of a desensitizing gel and toothpaste containing fluoride and potassium nitrate was effective in reducing dentinal hypersensitivity due to dental bleaching and did not interfere with the bleaching action of peroxides. Clinical significance: Desensitizing gels and toothpastes containing fluoride and potassium nitrate can be considered safe and effective in the control of tooth sensitivity after dental bleaching

Non-Perturbative Renormalisation of Composite Operators

It is shown that the renormalisation constants of two quark operators can be accurately determined (to a precision of a few per-cent using 18 gluon configurations) using Chiral Ward identities. A method for computing renormalisation constants of generic composite operators without the use of lattice perturbation theory is proposed.Comment: 3 pages, uuencoded compressed postscript file, to appear in the Proceedings of the International Symposium on Lattice Field Theory, Dallas, Texas, 12-17 October 1993, Southampton Preprint 93/94-0

Remark on lattice BRST invariance

A recently claimed resolution to the lattice Gribov problem in the context of chiral lattice gauge theories is examined. Unfortunately, I find that the old problem remains.Comment: 4 pages, plain TeX, presentation improved (see acknowledgments

The Ferroxidase Hephaestin in Lung Cancer: Pathological Significance and Prognostic Value

Hephaestin (HEPH) belongs to a group of exocytoplasmic ferroxidases which contribute to cellular iron homeostasis by favouring its export. Down-regulation of HEPH expression, possibly by stimulating cell proliferation due to an increase in iron availability, has shown to correlate with poor survival in breast cancer. The lung is particularly sensitive to iron-induced oxidative stress, given the high oxygen tension present, however, HEPH distribution in lung cancer and its influence on prognosis have not been investigated yet. In this study we explored the prognostic value of HEPH and its expression pattern in the most prevalent histotypes of lung cancers, namely lung adenocarcinoma and lung squamous cell carcinoma. In silico analyses, based on UALCAN, Gene Expression Profiling Interactive Analysis (GEPIA) and Kaplan–Meier plotter bioinformatics, revealed a significant correlation between higher levels of HEPH expression and favorable prognosis, in both cancer histotypes. Moreover, TIMER web platform showed a statistically significant association between HEPH expression and cell elements belonging to the tumor microenvironment identified as endothelial cells and a subpopulation of cancer-associated fibroblasts, further confirmed by double immunohistochemical labeling with cell type specific markers. Taken together, these data shed a light on the complex mechanisms of local iron handling lung cancer can exploit to support tumorigenesis

Protein-energy malnutrition halts hemopoietic progenitor cells in the G0/G1 cell cycle stage, thereby altering cell production rates

Protein energy malnutrition (PEM) is a syndrome that often results in immunodeficiency coupled with pancytopenia. Hemopoietic tissue requires a high nutrient supply and the proliferation, differentiation and maturation of cells occur in a constant and balanced manner, sensitive to the demands of specific cell lineages and dependent on the stem cell population. In the present study, we evaluated the effect of PEM on some aspects of hemopoiesis, analyzing the cell cycle of bone marrow cells and the percentage of progenitor cells in the bone marrow. Two-month-old male Swiss mice (N = 7-9 per group) were submitted to PEM with a low-protein diet (4%) or were fed a control diet (20% protein) ad libitum. When the experimental group had lost about 20% of their original body weight after 14 days, we collected blood and bone marrow cells to determine the percentage of progenitor cells and the number of cells in each phase of the cell cycle. Animals of both groups were stimulated with 5-fluorouracil. Blood analysis, bone marrow cell composition and cell cycle evaluation was performed after 10 days. Malnourished animals presented anemia, reticulocytopenia and leukopenia. Their bone marrow was hypocellular and depleted of progenitor cells. Malnourished animals also presented more cells than normal in phases G0 and G1 of the cell cycle. Thus, we conclude that PEM leads to the depletion of progenitor hemopoietic populations and changes in cellular development. We suggest that these changes are some of the primary causes of pancytopenia in cases of PEM.FAPESPCNP

Clinical significance of endometrial abnormalities: an observational study on 1020 women undergoing hysteroscopic surgery

Background: The overall clinical significance of the finding of endometrial abnormalities in predicting premalignant/malignant endometrial lesions is still incompletely determined. For this reason the management, surgical or expectant, of women in which an endometrial abnormality has been detected is debated. Methods: This retrospective study was carried out on 1020 consecutive women, 403 premenopausal and 617 postmenopausal, who underwent operative hysteroscopy in a University Hospital for suspected endometrial abnormalities, which were detected by transvaginal ultrasound (TVS) and/or office hysteroscopy. In these women, the clinical characteristics and findings at TVS and hysteroscopy were evaluated in relation to the presence/absence of premalignant/malignant endometrial lesions at pathology report. Results: The clinical characteristics considered were significantly different when the study women were compared according to their menopausal status. Premalignant/malignant lesions were found in 34/1020 (3.33%) women. Complex hyperplasia with atypia and endometrial cancer were detected in 22 (2.15%) and 12 (1.17%) cases, respectively. The postmenopausal women had a significantly higher risk of premalignant/malignant lesions than premenopausal women (O.R. = 5.098 [95% C.I.: 1.782–14.582], P &lt; 0.005). This risk was even higher when abnormal uterine bleeding (AUB) was present (O.R. = 5.20 [95% C.I.: 2.38–11.35], P &lt; 0.0001). The most significant associations with premalignant/malignant endometrial lesions were BMI, AUB in postmenopause, overall polyp size, atypical aspect of endometrial polyps at hysteroscopy, postmenopausal status, diabetes mellitus and patient age. Conclusions: The results of the present study suggest that the proper, aggressive or expectant, management of endometrial abnormalities should take into account both ultrasonographic and hysteroscopic findings together with the specific clinical characteristics of the patients

Metodologias para avaliação da integridade estrutural de cúpulas e abóbadas históricas em alvenaria

Modern non-destructive investigation techniques and computational tools for nonlinear analysis allow understanding the structural behavior and damage of existing buildings, aiming at the least possible extent of intervention. Careful and minimal intervention is essential to preserve the authenticity of the built cultural heritage. An investigation with a historical, experimental, and numerical approach was carried out in the Theatro Municipal do Rio de Janeiro, in Brazil, a building with an eclectic architecture from the beginning of the twentieth century. Its masonry domes and vault have paintings by renowned artists on their intrados and were strengthened in the 1970s. The adopted methodology was based on anamnesis, characterization and observation of the structure employing non-destructive tests, and on the assessment of its vulnerability by nonlinear analyses of calibrated numerical models. Several hypotheses of differential settlement under gravitational actions were investigated, seeking to reproduce the cracking pattern and to identify the causes of damage to the masonry domes and vault before the strengthening. The nonlinear analysis of the structure allowed to evaluate the causes of the observed damage, assess the level of safety, identify the most vulnerable parts, and characterize the collapse mechanisms, in addition to demonstrating the efficiency of the intervention measures adopted in the past.Técnicas modernas de investigação não destrutiva e ferramentas computacionais para análise não linear permitem compreender o comportamento estrutural e danos em edifícios existentes, visando a menor intervenção possível. A intervenção cuidadosa e mínima é essencial para preservar a autenticidade do patrimônio cultural construído. Uma investigação de abordagem histórica, experimental e numérica foi realizada no Theatro Municipal do Rio de Janeiro, no Brasil, edifício de arquitetura eclética do início do século XX. Suas cúpulas e abóbada em alvenaria possuem pinturas de renomados artistas no intradorso e foram reforçadas na década de 1970. A metodologia adotada baseou-se na anamnese, caracterização e observação da estrutura por meio de ensaios não destrutivos e na avaliação de sua vulnerabilidade por análises não lineares de modelos numéricos calibrados. Diversas hipóteses de recalque diferencial sob ações gravitacionais foram investigadas, buscando reproduzir o padrão de fissuração e identificar as causas dos danos nas alvenarias antes do reforço. A análise não linear da estrutura permitiu avaliar as causas dos danos observados, estimar o nível de segurança, identificar as partes mais vulneráveis e caracterizar os mecanismos de colapso, além de demonstrar a eficácia das medidas de intervenção adotadas no passado.This research was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001 and Faperj, grant number E-26/201.812/2017