Potencial quimiopreventivo de lipídios estruturados obtidos da Tributirina e Tricaprilina na fase de promoção da hepatocarcinogênese experimental / Chemopreventive potential of structured lipids obtained from Tributyrin and Tricaprylin in the promotion phase of experimental hepatocarcinogenesis

A quimioprevenção do câncer refere-se ao uso de compostos naturais ou sintéticos para prevenir o desenvolvimento das neoplasias antes do estabelecimento da malignidade. O ácido butirico (AB) atua como um potente quimiopreventivo na hepatocarcinogênese, reduzindo o número e o tamanho de lesões pré neoplásicas persistentes (pLPN), induzindo a apoptose e modulando mecanismos epigenéticos. Já o ácido caprílico (AC), além da sua atuação como potencializador de absorção, vem sendo investigado na área da prevenção do câncer. Neste cenário, o objetivo do trabalho visa avaliar a atividade quimiopreventiva de lipídios estruturados (EST) obtidos por interesterificação enzimática da tributirina com a tricaprilina, na fase de promoção da hepatocarcinogênese experimental. Após o processo de interesterificação, o produto final apresentou novos triacilgliceróis com composição de duas moléculas de ácido butírico para uma de ácido caprilíco. Ratos machos isogênicos da linhagem Fischer 344 foram submetidos ao modelo do hepatócito resistente, sendo distribuídos em dois grupos e tratados diariamente por via intragástrica com lipídios estruturados (EST) ou com o seu controle isocalórico, a maltodextrina (MD), durante a fase de promoção. Como esperado, não houve diferença estatística (p>0,05) em relação ao peso inicial e final dos animais dos grupos MD e EST, o que indica ausência de toxicidade dos compostos administrados. Na análise macroscópica do fígado, foi observada uma redução de 33,3% no grupo EST em relação ao número médio de nódulos macroscópicos em comparação ao grupo MD, porém essa redução não atingiu diferença estatística (p>0,05). Para a avaliação das lesões pré neoplásicas (LPN) foi utilizada a marcação imunoistoquímica para glutationa-S-transferase (GST-P). O grupo EST apresentou uma redução no número de lesões em remodelação e total GSTP-P+, quando comparado com o grupo MD (p<0,05). Quando avaliada a % de corpúsculos apoptóticos e índice de proliferação celular, não houve diferença estatística entre os grupos (p>0,05). Animais tratados com lipídios estruturados apresentaram maiores (p<0,05) concentrações de AC e AB por grama de tecido hepático em relação ao tratamento com maltodextrina. Em relação aos danos no DNA, o grupo EST resultou em cometas de comprimentos menores (p<0,05), menores níveis de γ-H2AX (p<0,05) e maiores concentrações de p53 nuclear, quando comparados aos animais que receberam maltodextrina, sugerindo uma proteção contra danos no DNA no grupo tratado com EST. Os resultados mostraram que o tratamento com EST resultou em ações efetivas na fase de promoção da hepatocarcinogênese experimental

Cancer chemoprevention refers to the use of natural or synthetic compounds to prevent the development of neoplasms before the establishment of malignancy. Butyric acid (AB) acts as a potent chemopreventive in hepatocarcinogenesis, reducing the number and size of persistent preneoplastic lesions (pLPN), inducing apoptosis and modulating epigenetic mechanisms. Caprylic acid (CA), in addition to its role as an absorption enhancer, has been investigated in the area of cancer prevention. In this scenario, the objective of this work was to evaluate the chemopreventive activity of structured lipids (EST) obtained by enzymatic interesterification of tributyrin with tricaprylin, in the phase of promotion experimental hepatocarcinogenesis. After the interesterification process, the final product presented new triacylglycerols with a composition of two molecules of butyric acid to one of caprylic acid. Isogenic male Fischer 344 rats were submitted to the resistant hepatocyte model, divided into two groups and treated daily intragastrically with structured lipids (EST) or with its isocaloric control, maltodextrin (MD), during the promotion phase. As expected, there was no statistical difference (p>0.05) in relation to the initial and final weight of the animals in the MD and EST groups, which indicates the absence of toxicity of the administered compounds. In the macroscopic analysis of the liver, a reduction of 33.3% was observed in the EST group in relation to the mean number of macroscopic nodules compared to the MD group, but this reduction did not reach a statistical difference (p>0.05). For the evaluation of pre-neoplastic lesions (PNL) immunohistochemical staining for glutathione-Stransferase (GST-P) was used. The EST group showed a reduction in the number of remodeling lesions and total GSTP-P+, when compared to the MD group (p<0.05). Animals treated with structured lipids had higher (p<0.05) concentrations of AC and AB per gram of liver tissue compared to treatment with maltodextrin. Regarding DNA damage, the EST group resulted in comets of shorter lengths (p<0.05), lower levels of γ-H2AX (p<0.05) and high concentration of nuclear p53, when compared to animals that received maltodextrin, suggesting protection against DNA damage in the EST treated group. The results showed that EST treatment resulted in effective actions in the promotion phase of experimental hepatocarcinogenesis

Evaluation of recombinant human interferon beta 1b by liquid chromatography methods and bioassay

Recombinant human interferon beta 1b (rhIFNß-1b) is clinically used to treat multiple sclerosis. A reversed-phase liquid chromatography (RP-LC) method was carried out on a Jupiter C4 column (250 mm × 4.6 mm i.d.). The mobile phase A consisted of 0.1% trifluoroacetic acid (TFA) in water, and the mobile phase B was acetonitrile with 0.1% TFA run at a flow rate of 1.0 mL/min. A size exclusion liquid chromatography (SE-LC) method was carried out on a BioSep-SEC-S 2000 column (300 mm × 7.8 mm i.d.). The mobile phase consisted of 1 mM monobasic potassium phosphate, 8 mM sodium phosphate dibasic and 200 mM sodium chloride buffer pH 7.4, run isocratically at a flow rate of 0.8 mL/min. Retention times were 31.87 and 17.78 min, and calibration curves were linear over the concentration range of 1-200 µg/mL (r2 = 0.9998) and 0.50-200 µg/mL (r2 = 0.9999), respectively, for RP-LC and SE-LC, with detection at 214 nm. Liquid chromatography (LC) methods were validated and employed in conjunction with the in vitro bioassay to assess the content/potency of rhIFNß-1b, contributing to improve the quality control and to ensure the efficacy of the biotherapeutic

From medical invention to clinical practice: the reimbursement challenge facing new device procedures and technology--part 2: coverage.

This paper, the second of 3 that discuss the reimbursement challenges facing new medical device technology in various issues of this journal, explains the key aspects of coverage that affect the adoption of medical devices. The process Medicare uses to make coverage determinations has become more timely and open over the past several years, but it still lacks the predictability that product innovators prefer. The continued uncertainty surrounding evidence requirements undermines the predictability needed for optimal product planning and innovation. Recent steps taken by the Centers for Medicare and Medicaid Services to provide coverage in return for evidence development should provide patients with access to promising new technologies and procedures while generating important evidence concerning their effectiveness.

Estimating research productivity and quality in assistive technology: a bibliometric analysis spanning four decades.

OBJECTIVE: Conduct a quantitative assessment of the number of papers contained in MEDLINE related to selected types of assistive technology (AT), and to identify journals publishing significant numbers of papers related to AT, and evaluate them with quantitative productivity and quality measures. DESIGN: Consecutive sample of all papers in MEDLINE identified by standard medical subject headings for selected types of AT from 1963-2003. MAIN OUTCOME MEASURES: Number of journals carrying AT papers, papers per journal (both total number and those specific to AT), journal impact factor, circulation, and number of AT citations per year over time for each area of AT. RESULTS: We present search terms, estimates of the numbers of AT citations in MEDLINE, the journals most likely to contain articles related to AT, journal impact factors, and journal circulations (when available). We also present the number of citations in various areas of AT over time from 1963-2003. Suggestions are presented for possible future modifications of the MEDLINE controlled vocabulary, based on terminology used in existing AT classifications schemes, such as ISO 9999. CONCLUSION: Research papers in the areas of AT examined showed publication across a wide variety of journals. There are a number of journals publishing articles in AT that have impact factors above the median. Some areas of AT have shown an increase in publications per year over time, while others have shown a more constant level of productivity.

The European biotechnology funding map.

Biotechnology is an industry with very strong links to basic science. Therefore, the commercialisation of biotechnology draws heavily on public funded research. All European countries have developed policies to support biotechnology. This contribution gives an overview of public funding activities in all European member states during the 90s and identifies the biotechnology areas which received funding in the different countries. About 50% of all funds were channelled to biomedical research. Plant biotechnology, industrial biotechnology, and the cell factory were other important targets of public funding. Other fields such as animal biotechnology, environmental biotechnology, and non-technical areas of biotechnology were largely ignored by public funding in most European countries. Future funding trends indicate that this pattern will be mainly preserved.

El embrión humano: una realidad necesitada de protección / Human embryo: a reality that needs protection

No disponible

Biotecnología ambiental / Environmental biotechnology

Nuestro ambiente está deteriorandose inexorablemente como resultado del continuo crecimiento de la población humana. La Organización Mundial de la Salud ha hecho un llamado acerca del hecho de que el número de personas que en la actualidad presentan enfermedades atribuidas a una pobre calidad ambiental está al borde de miles de millones. La Biotecnología Ambiental puede indudablemente jugar un importante papel en el esfuerzo de prevención del daño posterior al medio ambiente y a combatir las enfermedades asociadas. Existen dos tipos de aplicaciones clásicas en la Biotecnología Ambiental: en la Agricultura y en el tratamiento de desechos. Los organismos usados con aplicaciones agricolas y bacterias fijadoras de nitrógeno en el suelo. En cuanto al tratamiento de desechos, los más importantes desarrollos se encuentran en el campo de la biorremediación para el tratamiento de desechos tóxicos, tanto industriales como domésticos en el campo, en biorreactores o en procesos que los eliminen de los efluentes de fábricas