Evite as doenças transmitidas após as enchentes

RIO - O Ministério da Saúde publicou em seu site uma série de dicas que podem evitar a transmissão de doenças após as enchentes. A água da chuva misturada ao lixo e ao esgoto pode carregar vírus e bactérias que causam leptospirose, hepatite A e doenças diarréicas agudas. Além de evitar contato com a água suja, é preciso estar atento às frutas, legumes e verduras, que podem estar contaminados.

Proteja sua saúde com as recomendações do Ministério:

- A doença mais perigosa é a leptospirose, transmitida pela urina de ratos. Ela é causada por uma bactéria e pode causar febre, dor de cabeça e dor no corpo, principalmente nas panturrilhas. Se diagnosticada tardiamente, pode matar. Para evitar a contaminação, não entre em contato com água de enchente, mantenha os alimentos em recipientes resistentes e bem fechados, evite acumular lixo e não deixe sobras de ração de animais nos pratos. Se a água de chuva tiver entrado em casa, faça uma limpeza minuciosa com produtos contendo cloro ou água sanitária.

- Na hora de beber água, fique apenas com a fervida ou a tratada com hipoclorito de sódio a 2,5%. Use 2 gotas para cada litro de água e deixe a mistura descansar por 15 minutos.

- Cuidado com a caixa d'água. Ela deve ser esvaziada e desinfetada. Limpe bem o seu interior usando panos, esponjas e escovas, mas sem utilizar sabão, detergente, ou outros produtos de limpeza. Feito isso, deve-se deixar a água entrar, adicionar hipoclorito de sódio (um litro para cada mil litros de água) ou água sanitária e deixar agir por duas horas. Atenção: essa água com hipoclorito de sódio não deve ser ingerida! Por fim, é só esvaziar e encher a caixa novamente.

- Atenção redobrada aos animais peçonhentos. Aranhas, escorpiões e serpentes costumam aparecer depois de enchentes. Para prevenir picadas, bata colchões, roupas e sapatos e não coloque as mãos em buracos ou frestas.

- A contaminação dos alimentos acontece pela água infectada. Por isso, escolha muito bem o que vai comer. Qualquer alimento que tenha tido contato direto com a água das inundações deve ser descartado.

- Os produtos industrializados que estiverem em embalagens resistentes, intactas e lacradas - e que não sejam de plástico, papelão ou papel - devem ser higienizados também com hipoclorito de sódio (duas colheres diluídas em um litro de água).

- A nutricionista Mônica Dalmácio ensina que o vinagre não deve ser usado nessas situações, já que mata apenas algumas bactérias. Ela recomenda lavar todas as frutas e legumes primeiro com água e sabão e depois colocá-las de molho na mistura com hipoclorito de sódio.

- Além da leptospirose, alimentos contaminados podem transmitir hepatite A, salmonella, estafilococos e estreptococos, que podem causar febre, diarreia, dores de cabeça e intoxicação alimentar. Os cuidados com as frutas e os legumes devem continuar por no mínimo 30 dias após as chuvas.

MicroRNA Suppresses Prostate Cancer Stem Cells and Metastasis

ScienceDaily (Jan. 16, 2011) — A small slice of RNA inhibits prostate cancer metastasis by suppressing a surface protein commonly found on prostate cancer stem cells. miR-34a targets a surface protein common to cancer stem cells and associated with tumor development and metastasis. When the micro RNA stifles CD44, it inhibits formation of prostate stem cells. Researchers blocked tumor formation, shrunk tumors and inhibited metastasis in mouse models.

A research team led by scientists at The University of Texas MD Anderson Cancer Center reported January 16 in an advance online publication at Nature Medicine.

"Our findings are the first to profile a microRNA expression pattern in prostate cancer stem cells and also establish a strong rationale for developing the microRNA miR-34a as a new treatment option for prostate cancer," said senior author Dean Tang, Ph.D., professor in MD Anderson's Department of Molecular Carcinogenesis.

MicroRNAs, or miRNAs, are short, single-stranded bits of RNA that regulate the messenger RNA expressed by genes to create a protein.

Cancer stem cells are capable of self-renewal, have enhanced tumor-initiating ability and are generally more resistant to treatment than other cancer cells. They are associated with tumor recurrence and metastasis, the lethal spreading of cancer to other organs. These capacities are more prevalent in cancer cells that feature a specific cell surface protein called CD44, Tang said.

"CD44 has long been linked to promotion of tumor development and, especially, to cancer metastasis," Tang said. "Many cancer stem cells overexpress this surface adhesion molecule. Another significant finding from our study is identifying CD44 itself as a direct and functional target of miR-34a."

MicroRNA goes up, CD44 and cancer stem cells fall.

In a series of lab experiments with cell lines, human xenograft tumors in mice and primary human prostate cancer samples, the researchers demonstrated that miR-34a inhibits prostate cancer stem cells by suppressing CD44.

miR-34a is greatly reduced in prostate cancer cells that express high levels of CD44 on the cell surface. In 18 human prostate tumors, the microRNA was expressed at 25 to 70 percent of the levels found in cells without CD44.

Prostate tumors in mice that also received miR-34a treatment were one third to half the average size of those in control group mice.

In CD44-positive prostate cancer cell lines, treatment with miR-34a resulted in greatly reduced tumor incidence. Most dramatically, in one cell line, tumor regeneration was blocked in all 10 treated animals, while tumors formed in all 10 animals treated with the control miRNAs.

Many characteristics of cancer stem cells -- formation of self-renewing cells, clonal growth capacity and formation of spheres -- were suppressed when miR-34a was overexpressed in prostate cancer cell lines.

Most significantly, intravenous treatment of tumor-bearing mice with synthetic miR-34a reduced tumor burden by half in one tumor type. It also steeply reduced lung metastases in another tumor type, resulting in increased animal survival.

Interestingly, the researchers observed a consistent, inverse relationship between miR-34a levels and CD44, the surface marker used to enrich prostate cancer stem cells. For example, the CD44 protein and CD44-expressing cancer cells were reduced in tumors treated with the microRNA. Tumors with miR-34a blocked had higher levels of CD44 protein and messenger RNA.

Finally, knocking down CD44 with a short hairpin RNA produced the same results as treating cells with miR-34a did -- reduced tumor development, tumor burden and metastases.

"There are many companies developing microRNA-based drugs," Tang said. "Delivery of miRNAs is a challenge, but the field is moving fast through the preclinical stage."

Scientists from Austin-based Mirna Therapeutics collaborated on the study. Mirna has eight microRNAs in preclinical development, including miR-34a.

The project was funded in part by grants from the National Cancer Institute and the National Institute of Environmental Health Science, the U.S. Department of Defense and the Elsa Pardee Foundation.

Co-authors were first author Can Liu, Bigang Liu, M.D., Xin Chen, Tammy Calhoun-Davis, Hangwen Li, Ph.D., Hong Yan, Ph.D., Collene Jeter, Ph.D., and Sofia Honorio, Ph.D., all of MD Anderson's Department of Molecular Carcinogenesis at the Science Park in Smithville, Texas; Can Liu and Xin Chen are also students in The University of Texas Graduate School of Biomedical Sciences at Houston, jointly operated by MD Anderson and The University of Texas Health Science Center at Houston; Lubna Patrawala, Ph.D., Kevin Kelnar, Jason Wiggins, Andreas Bader, Ph.D., and David Brown, Ph.D., all of Mirna Therapeutics, Inc. and Randy Fagin, M.D., of The Hospital at Westlake, Austin, Texas.