Selol-loaded magnetic nanocapsules: A new approach for hyperthermia cancer therapy

Polylactic-co-glycolic nanocapsules, loaded with nanosized magnetic particles and Selol (a selenium-based anticancer drug), were successfully prepared by the precipitation method. Maghemite (gamma-Fe(2)O(3)) nanoparticles were incorporated into the nanocapsules using a highly stable ionic magnetic fluid sample. The obtained nanocapsules presented no agglomeration, negative surface charge while revealing a narrow monomodal size distribution. All the nanocapsule formulations exhibited a good physical stability at 4 degrees C during 3 month storage period. The in vitro antitumoral activity of Selol-magnetic nanocapsules was assessed using a murine melanoma cell line. The influence of nanocapsules on cell viability was investigated by spectrophotometric assay. The results demonstrated that Selol-loaded magnetic nanocapsules (at 100 mu g/ml/5 x 10(9) particle/ml) showed antitumoral activity of 50% on melanoma cells (absence of magnetic field). These results clearly indicate that the loaded nanocapsules represent a novel and promising magnetic drug delivery system suitable for cancer treatment via the active drug and magnetohyperthermia. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3556950]

Anti-tumor therapy with macroencapsulated endostatin producer cells

Background: Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors. Results: Mice were inoculated subcutaneously with melanoma (B16F10 cells) or Ehrlich tumor cells at the foot pads. Treatment began when tumor thickness had reached 0.5 mm, by subcutaneous implantation of 10(7) recombinant encapsulated or non-encapsulated endostatin producer cells. Similar melanoma growth inhibition was obtained for mice treated with encapsulated or non-encapsulated endostatin-expressing cells. The treatment of mice bearing melanoma tumor with encapsulated endostatin-expressing cells was decreased by 50.0%, whereas a decrease of 56.7% in tumor thickness was obtained for mice treated with non-encapsulated cells. Treatment of Ehrlich tumor-bearing mice with non-encapsulated endostatin-expressing cells reduced tumor thickness by 52.4%, whereas lower tumor growth inhibition was obtained for mice treated with encapsulated endostatin-expressing cells: 24.2%. Encapsulated endostatin-secreting fibroblasts failed to survive until the end of the treatment. However, endostatin release from the devices to the surrounding tissues was confirmed by immunostaining. Decrease in vascular structures, functional vessels and extension of the vascular area were observed in melanoma microenvironments. Conclusions: This study indicates that immunoisolation devices containing endostatin-expressing cells are effective for the inhibition of the growth of melanoma and Ehrlich tumors. Macroencapsulation of engineered cells is therefore a reliable platform for the refinement of innovative therapeutic strategies against tumors.

Retamycin production by immobilized cells of Streptomyces olindensis ICB20 in repeated-batch cultures

Repeated-batch cultures of Ca-alginate immobilized cells of Streptomyces olindensis ICB20 for retamycin production were carried out in two different bioreactors: a basket-type stirred tank reactor (BSTR) and a bubble column reactor (BCR). Higher average values of retamycin content (R) and productivity (P-R) were achieved in the BSTR cultures (about 1.7 AU and 0.031 AU h(-1), respectively) compared to those obtained in the BCR cultures (about 0.6 AU and 0.012 AU h(-1), respectively). The BCR, on the other hand, presented significantly better operation stability than the BSTR, which makes the former much more promising regarding future industrial applications. (C) 2008 Elsevier Ltd. All rights reserved.

Evaluation of curcumin and cisplatin-induced DNA damage in PC12 cells by the alkaline comet assay

A very appropriate method for antigenotoxicity evaluation of antioxidants is the comet assay, since this analytical method detects initial DNA lesions that are still subject to repair; in other words, lesions that are very associated to damages resulting from the generation and subsequent action of reactive species. However, a solid evaluation should be developed in order to avoid inexact interpretations. In our study, besides the association of curcumin with cisplatin, curcumin and cisplatin agents were also tested separately. Classical genotoxic compounds, when tested by the comet assay, present an increase in the nucleoid tail; however, the cisplatin treatment has resulted in a decrease of DNA migration. This was an expected effect, as the cross-links between cisplatin and DNA decrease the DNA electrophoretic mobility. A similar effect was observed with the curcumin treatment, which decreased the nucleoid tail. Such effect was not expected and reinforced the necessity of including in the study, separate treatment groups with potentially antigenotoxic substances. The comet assay results have been analyzed using specific software for image analysis, as well as the classical visual analysis, and we have observed that the effect of decrease in DNA electrophoretic mobility was more easily observed when the data were analyzed by the software.

Structural and functional properties of Bp-LAAO, a new L-amino acid oxidase isolated from Bothrops pauloensis snake venom

An L-amino acid oxidase (Bp-LAAO) from Bothrops pauloensis snake venom was highly purified using sequential chromatography steps on CM-Sepharose, Phenyl-Sepharose CL4B, Benzamidine Sepharose and C18 reverse-phase HPLC. Purified Bp-LAAO showed to be a homodimeric acidic glycoprotein with molecular weight around 65 kDa under reducing conditions in SDS-PAGE. The best substrates for Bp-LAAO were L-Met, L-Leu, L-Phe and L-Ile and the enzyme showed a strong reduction of its catalytic activity upon L-Met and L-Phe substrates at extreme temperatures. Bp-LAAO showed leishmanicidal, antitumoral and bactericidal activities dose dependently. Bp-LAAO induced platelet aggregation in platelet-rich plasma and this activity was inhibited by catalase. Bp-LAAC-cDNA of 1548 bp codified a mature protein with 516 amino acid residues corresponding to a theoretical isoelectric point and molecular weight of 6.3 and 58 kDa, respectively. Additionally, structural and phylogenetic studies identified residues under positive selection and their probable location in Elp-LAAO and other snake venom LAAOs (svLAAOs). Structural and functional investigations of these enzymes can contribute to the advancement of toxinology and to the elaboration of novel therapeutic agents. (C) 2009 Elsevier Masson SAS. All rights reserved.

Cytotoxic and mutagenic evaluation of extracts from plant species of the Miconia genus and their influence on doxorubicin-induced mutagenicity: An in vitro analysis

The Miconia genus, a plant widely used for medicine, occurs in tropical America and its extracts and isolated compounds have demonstrated antibiotic, antitumoral, analgesic and antimalarial activities. However, no study concerning its genotoxicity has been conducted and it is necessary to determine its potential mutagenic effects to develop products and chemicals from these extracts. This study assessed the cytotoxicity, mutagenicity and the protective effects of methanolic extracts from Miconia species on Chinese hamster lung fibroblast cell cultures (V79). The cytotoxicity was evaluated using a clonogenic assay. Cultures exposed to the extract of Miconia albicans up to a concentration of 30 mu g/mL, M. cabucu up to 40 mu g/mL, M. albicans up to 40 mu g/mL and M. stenostachya up to 60 mu g/mL exhibited a cytotoxic effect on the cells. The clonogenic assay used three non-cytotoxic concentrations (5, 10 and 20 mu g/mL) to evaluate mutagenicity and antimutagenicity of the extracts. Cultures were treated with these three extract concentrations (mutagenicity test) or the extract associated with doxorubicin (DXR) (antimutagenicity test) in three protocols (pre-, simultaneous and post-treatments). Distilled water and DXR were used as negative and positive controls, respectively. In the micronucleus (MN) test, a significant reduction was observed in MN frequency in cultures treated with DXR and extracts compared to those receiving only DXR; a significant reduction was also observed for the presence of mutagenicity in all treatments. This study confirmed the safe use of Miconia extracts at the concentrations tested and reinforced the therapeutic properties previously described for Miconia species by showing their protective effects on doxorubicin-induced mutagenicity. (C) 2010 Elsevier GmbH. All rights reserved.

Anticlastogenic and antigenotoxic effects of selenomethionine on doxorubicin-induced damage in vitro in human lymphocytes

The use of antioxidants during chemotherapy has been shown to reduce or prevent the undesirable effects experienced by healthy cells. Micronutrient selenium is well known for its antioxidant properties; however, selenium exhibits a bimodal nature in that both its beneficial and toxic properties lie within a limited and narrow dose range. The present study investigated the possible protective effects of selenomethionine (SM) on the cytotoxicity, genotoxicity and clastogenicity of the chemotherapic doxorubicin (DXR), a key chemotherapic used in cancer treatment. Human peripheral lymphocytes were treated in vitro with varying concentrations of SM (0.25 mu M, 0.5 mu M, 1.0 mu M and 2.0 mu M), tested in combination with DXR (0.15 mu g/mL). SM alone was not cytotoxic and when combined with DXR treatment, reduced the DNA damage index significantly, the frequency of chromosomal aberrations, the number of aberrant metaphases and the frequency of apoptotic cells. The mechanism of chemoprotection of SM may be related to its antioxidant properties as well as its ability to interfere with DNA repair pathways. Therefore this study showed that SM is effective in reducing the genetic damage induced by the antitumoral agent DXR. (C) 2007 Elsevier Ltd. All rights reserved.

Phase I trial of DNA-hsp65 immunotherapy for advanced squamous cell carcinoma of the head and neck

Considering that mycobacterial heat-shock protein 65 (hsp65) gene transfer can elicit a profound antitumoral effect, this study aimed to establish the safety, maximum-tolerated dose (MTD) and preliminary efficacy of DNA-hsp65 immunotherapy in patients with advanced head and neck squamous cell carcinoma (HNSCC). For this purpose, 21 patients with unresectable and recurrent HNSCC were studied. Each patient received three ultrasound-guided injections at 21-day intervals of: 150, 600 or 400 mu g of DNA-hsp65. Toxicity was graded according to CTCAE directions. Tumor volume was measured before and after treatment using computed tomography scan. The evaluation included tumor mass variation, delayed-type hypersensitivity response and spontaneous peripheral blood mononuclear cell proliferation before and after treatment. The MTD was 400 mg per dose. DNA-hsp65 immunotherapy was well tolerated with moderate pain, edema and infections as the most frequent adverse effects. None of the patients showed clinical or laboratory alterations compatible with autoimmune reactions. Partial response was observed in 4 out of 14 patients who completed treatment, 2 of which are still alive more than 3 years after the completion of the trial. Therefore, DNA-hsp65 immunotherapy is a feasible and safe approach at the dose of 400 mg per injection in patients with HNSCC refractory to standard treatment. Further studies in a larger number of patients are needed to confirm the efficacy of this novel strategy.

Resveratrol and quercetin cooperate to induce senescence-like growth arrest in C6 rat glioma cells

Glioma is the most frequent and malignant primary human brain tumor with dismal prognosis despite multimodal therapy. Resveratrol and quercetin, two structurally related and naturally occurring polyphenols, are proposed to have anticancer effects. We report here that resveratrol and quercetin decreased the cell number in four glioma cell lines but not in rat astrocytes. Low doses of resveratrol (10 mu M) or quercetin (25 mu M) separately had no effect on apoptosis induction, but had a strong effect on caspase 3/7 activation when administered together. Western blot analyses showed that resveratrol (10 mu M) and quercetin (25 mu M) caused a reduction in phosphorylation of Akt, but this reduction was not sufficient by itself to mediate the effects of these polyphenols. Most important, resveratrol and quercetin chronically administered presented a strong synergism in inducing senescence-like growth arrest. These results suggest that the combination of polyphenols can potentialize their antitumoral activity, thereby reducing the therapeutic concentration needed for glioma treatment. (Cancer Sci 2009; 100: 1655-1662).

Substance P and NK-1R expression in oral precancerous epithelium

The objectives of this study were to investigate the presence and distribution of substance P and neurokinin 1 receptor in oral premalignant epithelium and their relation with the presence of dysplasia, and to analyze whether the expression of substance P can be considered an early oncogenic event in oral carcinogenesis. Substance P and neurokinin I receptor expression was immunohistochemically studied in 83 oral carcinomas and adjacent nontumor epithelia. The presence and degree of epithelial dysplasia was assessed according to WHO criteria. The nuclear, cytoplasmic, and membrane expression of substance P and the cytoplasmic and membrane expression of neurokinin 1 receptor were assessed in tumor and adjacent non-tumor epithelium. Nuclear and cytoplasmic expression of substance P in non-tumor epithelium was significantly associated with the presence of epithelial dysplasia (p<0.001) and carcinoma in. situ (p=0.021). Nuclear, cytoplasmic, and membrane expressions of substance P in non-tumor epithelium were significantly (p<0.001) associated with its expression in the corresponding tumor. These findings suggest that substance P plays a role in early oral carcinogenesis by promoting the proliferation and growth of premalignant fields.

A Role for the Substance P/NK-1 Receptor Complex in Cell Proliferation in Oral Squamous Cell Carcinoma

Objective: To investigate the presence and distribution of substance P (SP) and neurokinin I receptor (NK-IR) in oral squamous cell carcinoma (OSCC) and their relationship with proliferation. Patients and Methods: Ninety OSCCs from 73 patients were immunohistochemically analyzed using monoclonal antibodies against SP, NK-IR and Ki-67 in a case and control study. Results: Seventy-one percent (n=49) of cases expressed SP on tumour cell membrane, 81.3% (n=69) in cytoplasm, 39.4% (n=28) in nucleus, 81.6% (n=71) in infiltrating lymphocytes, and 58.1% (n=43) in peritumoural or intratumoural blood vessels; 14% (n=12) of cases expressed NK-1R on tumour cell membrane, 50% (n=43) in cytoplasm, 48.3% (n=42) in infiltrating lymphocytes and 22.5% (n=18) in tumour blood vessels. All cases expressed Ki-67, which was expressed in >25% of tumour cells in 79.8% of cases (n=63). Direct significant associations were observed in SP expression between different tissue levels (p<0.01), between SP and NK-IR tumour cell membrane expression (p<0.01), and between joint,SP and NK-IR expression in tumour cell cytoplasm and a higher expression of Ki-67 (p<0.05). Conclusion: The ubiquitous presence of SP strongly suggests a role for SP/NK-1R complex in tumour development and progression and possibly for NK-IR antagonists, such as L-773060, in the management of patients with oral cancer.

Fatores etiológicos da deficiência auditiva em crianças e adolescentes de um centro de referência APADA em Salvador-BA

A audição representa a principal fonte para aquisição das habilidades de linguagem e fala da criança. A criança portadora de deficiência auditiva nos primeiros meses de vida é privada de estimulação sonora no período mais importante de seu desenvolvimento, e conseqüentemente, poderá apresentar alterações emocionais, sociais, e lingüísticas. Neste contexto é de suma relevância conhecer os principais fatores etiológicos que ocasionam a lesão auditiva para se traçar um perfil nosológico fidedigno, e serem tomadas as medidas cabíveis de prevenção e orientação as famílias sobre as repercussões da deficiência auditiva na infância. OBJETIVOS: Caracterizar o perfil etiológico da deficiência auditiva em um centro de referência para atendimento a crianças e adolescentes deficientes auditivos. METODOLOGIA: Foram realizadas entrevistas, triagem fonoaudiológica e avaliação de prontuários de 87 crianças deficientes auditivas cadastradas na Associação de Pais e Amigos dos Deficientes Auditivos do Estado da Bahia(APADA-BA), buscando-se determinar a etiologia, distribuição por sexo, idade do diagnóstico, grau de deficiência, idade de protetização e da reabilitação fonoaudiológica. RESULTADOS: Dentre as 87 crianças e adolescentes que passaram pela triagem fonoaudiológica, selecionamos uma amostra de 53 sujeitos, cujos pais compareceram as três sessões de anamnese e avaliação. O principal fator etiológico responsável pela deficiência auditiva na população avaliada foi a rubéola materna responsável por 32% dos casos de surdez, seguida pela meningite piogênica com 20%, causa idiopática com 15%, prematuridade com 9%, hereditariedade (pai ou mãe surdo) e icterícia neonatal também apresentaram incidência de 6%; otite média crônica representou 4%, uso de misoprostol na gestação, sarampo, ototoxicidade e caxumba apareceram na amostra, cada fator, com 2%. CONCLUSÃO: O presente estudo demonstrou a heterogeneidade de fatores que ocasionam o comprometimento auditivo, e como as duas principais causas (rubéola e meningite piogênica) ainda apresentam uma incidência alta na população em estudo. Acreditamos que medidas de prevenção devem ser tomadas, principalmente na profilaxia da rubéola materna e na vacinação ampliada de neonatos e lactentes contra a meningite bacteriana.

Caracterização do sistema de saúde na assistência a doentes diabéticos com base numa farmácia comunitária

Introdução: O Programa de Controlo da Diabetes Mellitus de 1998 tem como objectivo procurar a integração dos vários profissionais de saúde num ambicioso projecto cujo objectivo final é dar mais qualidade de vida aos doentes diabéticos. Neste programa, ao lado do médico de medicina geral e familiar, da enfermeira, do médico hospitalar é integrado o farmacêutico. Método: Estudo transversal (epidemiologia descritiva) realizado numa farmácia comunitária, durante dois meses realizado sobre todos os indivíduos utentes de uma farmácia comunitária portadores de uma prescrição médica para o próprio com pelo menos um antidiabético oral, insulina ou material de autovigilância. Os doentes foram questionados quanto à utilização do Guia do Diabético (GD), número de consultas médicas nos últimos 3 meses, realização de exames oftalmológicos alguma vez na vida e nos últimos 12 meses, vacinação da gripe no último inverno e sobre qual o papel dos vários profissionais de saúde da educação terapêutica do doente diabético. Resultados: Na resposta à pergunta se têm o GD, 82,9% (68/82) afirmou que o tinha. Dos 56 doentes que realizam dieta alimentar, em 87,5% (49/56) a dieta foi instituída pelo médico, em 32,1% (18/56) pelo farmacêutico, em 7,1% (4/56) pelo enfermeiro e em 19,6% (11/56) pelo dietista. Apenas 56% dos doentes tiveram consulta de oftalmologia no último ano. Apenas 37% dos doentes receberam a vacina para a gripe no último inverno. Discussão: Melhorias na articulação entre as diversas entendidas envolvidas na prevenção e no tratamento da diabetes devem ser introduzidas, visando o alcance de resultados clínicos positivos nos doentes diabéticos. Conclusão: Apenas 56% dos doentes tiveram consulta de oftalmologia no último ano. Apenas 37% dos doentes receberam a vacina para a gripe no último Inverno. As farmácias são locais adequados para a realização de estudos sobre a qualidade dos serviços de saúde prestados.

Estudo epidemiológico da Leishmaniose canina na zona da Arrábida

A Leishmmaniose canina é uma zoonose endémica provocada por um protozoário do género Leishmania cujo ciclo de vida requer a existência de um hospedeiro intermediário, o flebótomo e de um hospedeiro definitivo, o cão. É uma doença sistémica cuja sintomatologia clássica inclui a anorexia, letargia, poliúria e polidipsia, lesões cutâneas, linfadenomegália, epistáxis e onicogrifose. Muitos animais podem estar infectados mas permanecerem assintomáticos. O diagnóstico deve ser feito pela conjugação da sintomatologia clínica, resultados hematológicos e bioquímicos e resultados laboratoriais como testes serológicos e/ou provas de biologia molecular. Existem várias formas de tratamento da doença, no entanto nenhum protocolo leva à cura parasitológica da doença, mas apenas à remissão da sintomatologia. Várias medidas preventivas podem ser levadas a cabo, como o uso de coleiras insecticidas e num futuro próximo a possível vacinação. O estudo epidemiológico apresentado utilizou uma amostra de 60 cães, aos quais foi realizado um exame clínico e recolha de sangue para análise de hemograma, parâmetros bioquímicos e análise laboratorial, com o fim de se diagnosticar Leishmaniose canina na zona da Arrábida. Foram diagnosticados 34 animais infectados, dos quais 13 eram portadores assintomáticos descobertos pelo uso das técnicas de Imunofluorescência Indirecta, Teste de Aglutinação Directa e Polymerase Chain Reaction.

Estado atual do problema da poliomielite no município de São Paulo

Estudo do problema da poliomielite no município de São Paulo, desde 1933 até 1967, dando ênfase ao período de 1962 a 1967, quando é analisada a relação entre a variação da incidência da doença em tela e as campanhas de vacinação em massa com a vacina de vírus vivos atenuados, então relizadas. Com base nos dados apresentados, conclue-se que no ano de 1967, em que o coeficiente de morbidade por 100.000 habitantes por poliomielite foi de 0,6, foi possível se conseguir o controle dessa doença em nossa Capital.