Tabagismo e câncer no Brasil: evidências e perspectivas

Neste artigo analisa-se a tendência temporal da prevalência do tabagismo no Brasil, bem como as assimetrias da prevalência de acordo com as regiões do país, a idade, o gênero e o nível socioeconômico da população. Desde o estabelecimento da relação entre tabagismo e câncer de pulmão há 60 anos, o número de tumores malignos com evidências de associação causal com o tabagismo ascendeu a vinte. O declínio da prevalência do tabagismo na população brasileira tem sido constante desde o final da década de 80. Até 2003, foi mais intenso entre os homens. A partir daquele ano, a queda tornou-se mais pronunciada entre as mulheres. As mais altas prevalências de tabagismo encontram-se no Sudeste e Sul, as duas regiões com maiores incidências de neoplasias estritamente relacionadas ao tabaco (cavidade oral, esôfago e pulmão). A exposição ambiental à fumaça do tabaco também foi examinada considerando-se os efeitos para os adultos não fumantes, que apresentam maior risco de tumores de pulmão, laringe e faringe, e entre crianças de pais fumantes, suscetíveis ao risco de hepatoblastoma e leucemia linfocítica aguda. Apesar do incontestável sucesso da política de controle do tabagismo no país, as ações de prevenção devem considerar que as parcelas da população com piores condições socioeconômicas e com baixo nível educacional são as que apresentam taxas mais altas de prevalência de tabagismo. Dentro destes segmentos populacionais os adolescentes representam uma prioridade

Searching for molecular markers in head and neck squamous cell carcinomas (HNSCC) by statistical and bioinformatic analysis of larynx-derived SAGE libraries

Background: Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancies in humans. The average 5-year survival rate is one of the lowest among aggressive cancers, showing no significant improvement in recent years. When detected early, HNSCC has a good prognosis, but most patients present metastatic disease at the time of diagnosis, which significantly reduces survival rate. Despite extensive research, no molecular markers are currently available for diagnostic or prognostic purposes. Methods: Aiming to identify differentially-expressed genes involved in laryngeal squamous cell carcinoma (LSCC) development and progression, we generated individual Serial Analysis of Gene Expression (SAGE) libraries from a metastatic and non-metastatic larynx carcinoma, as well as from a normal larynx mucosa sample. Approximately 54,000 unique tags were sequenced in three libraries. Results: Statistical data analysis identified a subset of 1,216 differentially expressed tags between tumor and normal libraries, and 894 differentially expressed tags between metastatic and non-metastatic carcinomas. Three genes displaying differential regulation, one down-regulated (KRT31) and two up-regulated (BST2, MFAP2), as well as one with a non-significant differential expression pattern (GNA15) in our SAGE data were selected for real-time polymerase chain reaction (PCR) in a set of HNSCC samples. Consistent with our statistical analysis, quantitative PCR confirmed the upregulation of BST2 and MFAP2 and the downregulation of KRT31 when samples of HNSCC were compared to tumor-free surgical margins. As expected, GNA15 presented a non-significant differential expression pattern when tumor samples were compared to normal tissues. Conclusion: To the best of our knowledge, this is the first study reporting SAGE data in head and neck squamous cell tumors. Statistical analysis was effective in identifying differentially expressed genes reportedly involved in cancer development. The differential expression of a subset of genes was confirmed in additional larynx carcinoma samples and in carcinomas from a distinct head and neck subsite. This result suggests the existence of potential common biomarkers for prognosis and targeted-therapy development in this heterogeneous type of tumor.

Leukotriene B(4)-loaded microspheres: a new therapeutic strategy to modulate cell activation

Background: Leukotriene B(4) (LTB(4)) is a potent inflammatory mediator that also stimulates the immune response. In addition, it promotes polymorphonuclear leukocyte phagocytosis, chemotaxis, chemokinesis and modulates cytokines release. Regarding chemical instability of the leukotriene molecule, in the present study we assessed the immunomodulatory activities conferred by LTB(4) released from microspheres (MS). A previous oil-in-water emulsion solvent extraction-evaporation method was chosen to prepare LTB(4)-loaded MS. Results: In the mice cremasteric microcirculation, intraescrotal injection of 0.1 ml of LTB(4)-loaded MS provoked significant increases in leukocyte rolling flux, adhesion and emigration besides significant decreases in the leukocyte rolling velocity. LTB(4)-loaded MS also increase peroxisome proliferator-activated receptor-alpha (PPAR alpha) expression by murine peritoneal macrophages and stimulate them to generate nitrite levels. Monocyte chemoattractant protein-I (MCP-I) and nitric oxide (NO) productions were also increased when human umbilical vein and artery endothelial cells (HUVECs and HUAECs, respectively) were stimulated with LTB(4)-loaded MS. Conclusion: LTB(4)-loaded MS preserve the biological activity of the encapsulated mediator indicating their use as a new strategy to modulate cell activation, especially in the innate immune response.

Preliminary biocompatibility investigation of magnetic albumin nanosphere designed as a potential versatile drug delivery system

Background: The magnetic albumin nanosphere (MAN), encapsulating maghemite nanoparticles, was designed as a magnetic drug delivery system (MDDS) able to perform a variety of biomedical applications. It is noteworthy that MAN was efficient in treating Ehrlich's tumors by the magnetohyperthermia procedure. Methods and materials: In this study, several nanotoxicity tests were systematically carried out in mice from 30 minutes until 30 days after MAN injection to investigate their biocompatibility status. Cytometry analysis, viability tests, micronucleus assay, and histological analysis were performed. Results: Cytometry analysis and viability tests revealed MAN promotes only slight and temporary alterations in the frequency of both leukocyte populations and viable peritoneal cells, respectively. Micronucleus assay showed absolutely no genotoxicity or cytotoxicity effects and histological analysis showed no alterations or even nanoparticle clusters in several investigated organs but, interestingly, revealed the presence of MAN clusters in the central nervous system (CNS). Conclusion: The results showed that MAN has desirable in vivo biocompatibility, presenting potential for use as a MDDS, especially in CNS disease therapy.

Composite electrode of carbon nanotubes and vitreous carbon for electron field emission

In this work, the electron field emission behaviour of electrodes formed by carbon nanotubes (CNTs) grown onto monolithic vitreous carbon (VCarbon) substrates with microcavities is presented. Scanning electron microscopy was used to characterize the microstructure of the films. Tungsten probes, stainless steel sphere, and phosphor electrodes were employed in the electron field emission study. The CNT/VCarbon composite represents a route to inexpensive excellent large area electron emission cathodes with fields as low as 2.1 V mu m(-1). In preliminary lifetime tests for a period of about 24 h at an emission current of about 4 mA cm(-2), there is an onset degradation of the emission current of about 28%, which then stabilizes. Electron emission images of the composites show the cavity of the samples act as separate emission sites and predominantly control the emission process. The emission of CNTs/VCarbon was found to be stable for several hours. (c) 2008 American Institute of Physics.

Cell Therapy Attenuates Cardiac Dysfunction Post Myocardial Infarction: Effect of Timing, Routes of Injection and a Fibrin Scaffold

Background: Cell therapy approaches for biologic cardiac repair hold great promises, although basic fundamental issues remain poorly understood. In the present study we examined the effects of timing and routes of administration of bone marrow cells (BMC) post-myocardial infarction (MI) and the efficacy of an injectable biopolymer scaffold to improve cardiac cell retention and function. Methodology/Principal Findings: (99m)Tc-labeled BMC (6x10(6) cells) were injected by 4 different routes in adult rats: intravenous (IV), left ventricular cavity (LV), left ventricular cavity with temporal aorta occlusion (LV(+)) to mimic coronary injection, and intramyocardial (IM). The injections were performed 1, 2, 3, or 7 days post-MI and cell retention was estimated by gamma-emission counting of the organs excised 24 hs after cell injection. IM injection improved cell retention and attenuated cardiac dysfunction, whereas IV, LV or LV* routes were somewhat inefficient (< 1%). Cardiac BMC retention was not influenced by timing except for the IM injection that showed greater cell retention at 7 (16%) vs. 1, 2 or 3 (average of 7%) days post-MI. Cardiac cell retention was further improved by an injectable fibrin scaffold at day 3 post-MI (17 vs. 7%), even though morphometric and function parameters evaluated 4 weeks later displayed similar improvements. Conclusions/Significance: These results show that cells injected post-MI display comparable tissue distribution profile regardless of the route of injection and that there is no time effect for cardiac cell accumulation for injections performed 1 to 3 days post-MI. As expected the IM injection is the most efficient for cardiac cell retention, it can be further improved by co-injection with a fibrin scaffold and it significantly attenuates cardiac dysfunction evaluated 4 weeks post myocardial infarction. These pharmacokinetic data obtained under similar experimental conditions are essential for further development of these novel approaches.

High-Density Lipoprotein Inhibits the Uptake of Modified Low-Density Lipoprotein and the Expression of CD36 and Fc gamma RI

Aim: Modified low-density lipoprotein (mLDL), mainly upon oxidative and enzymatic modification, is the major atherogenic lipoprotein. Conversely, high-density lipoprotein (HDL) is considered anti-atherogenic because of its ability to remove cholesterol. The aim of this work was to analyze both the influence of HDL on the uptake of mLDL and the expression of CD36 and Fc gamma I receptors on monocytic cell lines during cell differentiation. Methods: Uptake of fluorescein isothiocyanate (FITC)-conjugated LDL and FITC-conjugated mLDL, i.e., copper-oxidized LDL (oxLDL) or trypsin enzyme modified LDL (enzLDL), was analyzed, as well as the expression of CD36 and Fc gamma RI in THP-1 and U937 cells, using flow cytometry. Results: HDL inhibited the uptake of mLDL, which varied in degree depending on the cell line or type of mLDL. Further, HDL rapidly decreased CD36 and Fc gamma RI involved in the uptake of mLDL. Conclusions: We demonstrate that modified LDL promotes specific LDL receptor-independent uptake by monocytic cell lines, and that the uptake of LDL and enzLDL is less than that of oxLDL. In this process, HDL diminishes the uptake of LDL or mLDL, which may involve the down-regulation of receptors (CD36 and Fc gamma I). This regulatory process represents another way by which HDL can be anti-atherogenic and it depends on the type of modification of LDL and the stage of differentiation of monocytes to macrophages.

Association between intratumoral lymphatic microvessel density (LMVD) and clinicopathologic features in endometrial cancer: a retrospective cohort study

Background: Lymph node metastasis in endometrial cancer significantly decreases survival rate. Few data on the influence of intratumoral lymphatic microvessel density (LMVD) on survival in endometrial cancer are available. Our aim was to assess the intratumoral LMVD of endometrial carcinomas and to investigate its association with classical pathological factors, lymph node metastasis and survival. Methods: Fifty-seven patients with endometrial carcinoma diagnosed between 2000 and 2008 underwent complete surgical staging and evaluation of intratumoral LMVD and other histologic variables. Lymphatic microvessels were identified by immunohistochemical staining using monoclonal antibody against human podoplanin (clone D2-40) and evaluated by counting the number of immunostained lymphatic vessels in 10 hot spot areas at 400x magnification. The LMVD was expressed by the mean number of vessels in these 10 hot spot microscopic fields. We next investigated the association of LMVD with the clinicopathologic findings and prognosis. Results: The mean number of lymphatic vessels counted in all cases ranged between 0 and 4.7. The median value of mean LMVD was 0.5, and defined the cut-off for low and high LMVD. We identified low intratumoral LMVD in 27 (47.4%) patients and high LMVD in 30 (52.6%) patients. High intratumoral LMVD was associated with lesser miometrial and adnaexal infiltration, lesser cervical and peritoneal involvement, and fewer fatal cases. Although there was lower lymph node involvement among cases with high LMVD, the difference did not reach significance. No association was seen between LMVD and FIGO staging, histological type, or vascular invasion. On the other hand, low intratumoral LMVD was associated with poor outcome. Seventy-five percent of deaths occurred in patients with low intratumoral LMVD. Conclusion: Our results show association of high intratumoral LMVD with features related to more localized disease and better outcome. We discuss the role of lymphangiogenesis as an early event in the endometrial carcinogenesis.

Isolation of Mycobacterium tuberculosis from Captive Ateles paniscus

An adult female red-faced black spider monkey (Ateles paniscus), housed for 2 years in the Parque Estoril Zoo in Sao Paulo, Brazil, showed apathy. Clinical examination revealed discrete emaciation, swelling and induration of lymph nodes, and presence of a mass in the abdominal cavity. Therapies with enrofloxacin, azithromycin, and ceftiofur were ineffective. The animal died after 6 months. Necropsy and histopathology confirmed granulommas in lymph nodes, parietal and visceral pleura, lungs, liver, spleen, and kidneys. Acid-fast bacilli were isolated and identified as Mycobacterium tuberculosis by polymerase chain reaction restriction analysis and Spoligotyping techniques. The zoo personnel and other animals that had had contact with the infected primate were negative to tuberculosis diagnostic procedures, such as sputum exam (baciloscopy) and thorax radiography. It was impossible to determine whether the infection occurred before or after the arrival of the animal to the Parque Estoril Zoo. This is the first report of M. tuberculosis infection in Ateles paniscus, a neotropical primate.

Analysis of Permeability and Morphology of Root Canal Dentin After Er,Cr:YSGG Laser Irradiation

Objective: The aim of this study was to evaluate the morphology and permeability of root canal walls irradiated with Er,Cr:YSGG laser after conventional endodontic treatment. Background: Laser irradiation can be used for dentinal tubule exposure, smear layer removal, and disinfection. Another potential, interesting application is as an adjunct to endodontic treatment, especially in the intracanal medication phase. Methods: Fifty-two single-rooted teeth had their crowns sectioned at the cementoenamel junction and were randomly divided into four groups (n = 13): G1: conventional preparation (CP) + irrigation with EDTA-T+rhodamine B dye solution associated with NDP (dexamethasone phosphate, paramonochlorophenol, polyethylenoglycol) (Rhod-NDP); G2: CP+EDTA-T + Er,Cr:YSGG laser irradiation 0.75W+Rhod-NDP; G3: CP + EDTA-T + Er,Cr:YSGG 1.5W+Rhod-NDP; G4: CP + EDTA-T + Er,Cr:YSGG 2.5W + Rhod-NDP. For the permeability analysis (n = 9), teeth were transversely cut and two slices of each third were selected. The images were analyzed by ImageLab software (Softium Informatica Ltda., Sao Paulo, SP, Brazil). Additional samples (n = 4) were examined by scanning electron microscopy. Results: Data were analyzed statistically using the Kruskal-Wallis and Student-Newman-Keuls tests for the following areas: apical third (H = 23.4651): G1 (14.25)(a), G2 (17.66)(ab), G3 (26.50)(b), G4 (39.58)(c); medium (H = 23.1611): G1 (14.16)(a), G2 (16.66)(ab), G3 (28.83)(b), G4 (38.33)(b); and cervical (H = 32.4810): G1 (9.66)(a), G2 (20.00)(ab), G3 (27.00)(b), G4 (41.33)(c), (p<0.01). Despite the irregular aspect of laser irradiation along the canal walls, the parameters of 1.5W and 2.5W allowed morphologic modifications that increased dentinal permeability. Conclusions: Irradiation with Er, Cr: YSGG laser could be effective in endodontic treatment for increasing dentinal permeability.

Epigenetic Silencing of CRABP2 and MX1 in Head and Neck Tumors

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease affecting the epithelium of the oral cavity, pharynx and larynx. Conditions of most patients are diagnosed at late stages of the disease, and no sensitive and specific predictors of aggressive behavior have been identified yet. Therefore, early detection and prognostic biomarkers are highly desirable for a more rational management of the disease. Hypermethylation of CpG islands is one of the most important epigenetic mechanisms that leads to gene silencing in tumors and has been extensively used for the identification of biomarkers. In this study, we combined rapid subtractive hybridization and microarray analysis in a hierarchical manner to select genes that are putatively reactivated by the demethylating agent 5-aza-2'-deoxycytidine (5Aza-dC) in HNSCC cell lines (FaDu, UM-SCC-14A, UM-SCC-17A, UM-SCC-38A). This combined analysis identified 78 genes, 35 of which were reactivated in at least 2 cell lines and harbored a CpG island at their 5' region. Reactivation of 3 of these 35 genes (CRABP2, MX1, and SLC15A3) was confirmed by quantitative real-time polymerase chain reaction (PCR; fold change, >= 3). Bisulfite sequencing of their CpG islands revealed that they are indeed differentially methylated in the HNSCC cell lines. Using methylation-specific PCR, we detected a higher frequency of CRABP2 (58.1% for region 1) and MX1 (46.3%) hypermethylation in primary HNSCC when compared with lymphocytes from healthy individuals. Finally, absence of the CRABP2 protein was associated with decreased disease-free survival rates, supporting a potential use of CRABP2 expression as a prognostic biomarker for HNSCC patients.

Severity of Oral Mucositis in Patients Undergoing Hematopoietic Cell Transplantation and an Oral Laser Phototherapy Protocol: A Survey of 30 Patients

Background Data and Objective: Oral mucositis (OM) is one of the worst cytotoxic effects of chemotherapy and radiotherapy in patients undergoing hematopoietic cell transplantation (HCT), and it causes severe morbidity. Laser phototherapy has been considered as an alternative therapy for prevention and treatment of OM. The aim of this study was to describe the incidence and severity of OM in HCT patients subjected to laser phototherapy, and to discuss its effect on the oral mucosa. Patients and Methods: Information concerning patient age and gender, type of basic disease, conditioning regimen, type of transplant, absence or presence of pain related to the oral cavity, OM grade, and adverse reactions or unusual events were collected from 30 patients undergoing HCT (allogeneic or autologous). These patients were given oral laser phototherapy with a InGaAIP laser (660 nm and 40 mW) daily. The data were tabulated and their frequency expressed as percentages. Results: In the analysis of those with OM, it was observed that 33.4% exhibited grade I, 40% grade II, 23.3% grade III, and 3.3% grade IV disease. On the most critical post-HCT days (D+5 and D+8), it was observed that 63.3% of patients had grade I and 33.3% had grade II disease; no patients had grade III or IV disease in this period. This severity of OM was similar to that seen in other studies of laser phototherapy and OM. Conclusion: The low grades of OM observed in this survey show the beneficial effects of laser phototherapy, but randomized clinical trials are necessary to confirm these findings.

Laser Phototherapy for Stevens-Johnson Syndrome: A Case Report

Background and Objective: Stevens-Johnson syndrome (SJS) is a life-threatening dermatosis characterized by epidermal sloughing and stomatitis. We report the case of a 7-year-old boy in whom laser phototherapy (LPT) was highly effective in reversing the effects of an initial episode of SJS that had apparently developed in association with treatment with phenobarbital for a seizure disorder. The patient was first seen in the intensive care unit (ICU) of our institution with fever, cutaneous lesions on his extremities, trunk, face, and neck; mucosal involvement of his genitalia and eyes (conjunctivitis); ulcerative intraoral lesions; and swollen, crusted, and bleeding lips. He reported severe pain at the sites of his intraoral and skin lesions and was unable to eat, speak, swallow, or open his mouth. Materials and Methods: Trying to prevent and minimize secondary infections, gastric problems, pain, and other complications, the patient was given clindamycin, ranitidine, dipyrone, diphenhydramine (Benadryl) drops, and morphine. In addition, he was instructed to use bicarbonate solution and Ketoconazole (Xylogel) in the oral cavity. Because of the lack of progress of the patient, the LPT was selected. Results: At 5 days after the initial session of LPT, the patient was able to eat gelatin, and on the following day, the number and severity of his intraoral lesions and his labial crusting and swelling had diminished. By 6 days after his initial session of LPT, most of the patient's intraoral lesions had disappeared, and the few that remained were painless; the patient was able to eat solid food by himself and was removed from the ICU. Ten sessions of LPT were conducted in the hospital. The patient underwent three further and consecutive sessions at the School of Dentistry, when complete healing of his oral lesions was observed. Conclusion: The outcome in this case suggests that LPT may be a new adjuvant modality for SJS complications.

Improvement in Quality of Life of An Oncological Patient by Laser Phototherapy

Objective and Background Data: Common side effects of radiotherapy (RT) to the head and neck include oral mucositis, xerostomia, and severe pain. The aim of this study is to report improvement in the quality of life of an oncological patient by laser phototherapy (LPT). Clinical Case and Laser Phototherapy Protocol: The patient, a 15-year-old girl diagnosed with mucoepidermoid carcinoma, underwent surgical excision of a tumor of the left palatomaxilla. After that, she was subjected to 35 sessions of RT (2 Gy/d). Clinical examination revealed the spread of severe ulcerations to the jugal mucosa, gums, lips, hard palate, and tongue (WHO mucositis score 3). She had difficulty in moving her tongue and she was unable to eat any solid food. Oral hygiene orientation and LPT were performed throughout all RT sessions. A continuous diode laser, 660 nm, 40 mW, 6 J/cm(2), 0.24 J per point in contact mode, with spot size of 0.04 cm(2) was used in the entire oral cavity. A high-power diode laser at 1 W, 10 sec per cm of mucositis, approximately 10 J/cm(2), was used in defocused mode only on ulcerative lesions. After the first laser irradiation session, decreases in pain and xerostomia were reported; however, a more significant improvement was seen after five sessions. At that point although the mucositis score was still 2, the patient reported that she was free of pain, and consequently a palatine plate could be made to rehabilitate the entire surgical area. Seventeen laser irradiation sessions were necessary to eliminate all oral mucositis lesions. Conclusion: Normal oral function and consequent improvements in the quality of life of this oncologic patient were observed with LPT.

Ablation Rate and Morphology of Superficial and Deep Dentin Irradiated with Different Er:YAG Laser Energy Levels

Objective: In this study we evaluated the ablation rate of superficial and deep dentin irradiated with different Er:YAG laser energy levels, and observed the micromorphological aspects of the lased substrates with a scanning electron microscope (SEM). Background Data: Little is known about the effect of Er: YAG laser irradiation on different dentin depths. Materials and Methods: Sixty molar crowns were bisected, providing 120 specimens, which were randomly assigned into two groups ( superficial or deep dentin), and later into five subgroups (160, 200, 260, 300, or 360 mJ). Initial masses of the specimens were obtained. After laser irradiation, the final masses were obtained and mass losses were calculated followed by the preparation of specimens for SEM examination. Mass-loss values were subjected to two-way ANOVA and Fisher's least significant difference multiple-comparison tests (p < 0.05). Results: There was no difference between superficial and deep dentin. A significant and gradual increase in the mass-loss values was reached when energies were raised, regardless of the dentin depth. The energy level of 360 mJ showed the highest values and was statistically significantly different from the other energy levels. The SEM images showed that deep dentin was more selectively ablated, especially intertubular dentin, promoting tubule protrusion. At 360 mJ the micromorphological features were similar for both dentin depths. Conclusion: The ablation rate did not depend on the depth of the dentin, and an energy level lower than 360 mJ is recommended to ablate both superficial and deep dentin effectively without causing tissue damage.