Problemas bioéticos en la investigación de nuevas vacunas: ¿obedecen a razones de salud pública? / Bioethical problems in researching new vaccines: Do they respond to public health reasons?

Los problemas éticos de las investigaciones sobre vacunas han crecido en las últimas décadas en frecuencia y magnitud debido a la posición dominante de la industria farmacéutica en el desarrollo de esos estudios. Las tradicionales cuestiones de seguridad y eficacia se han visto agravadas por el conflicto de intereses introducido por la competencia comercial en un mercado a escala global de miles de millones de dólares. La integridad profesional de los investigadores, la responsabilidad moral de los patrocinadores, y la regulación y control por parte de los Estados nacionales, se muestra cuestionada en varios ejemplos. Los resultados de estos cambios son las amenazas a la protección de los derechos de las personas incluidas en estas investigaciones y el discutible progreso que resulta para la salud pública.

The ethical problems in vaccine research have grown in frequency and magnitude in last decades, due to the dominant place of the pharmaceutical industry in the development of such studies. Traditional issues of security and efficacy have been aggravated by the conflicts of interests introduced by commercial competition in a global market worth billions of dollars. We present here a few examples in which the professional integrity of researchers, the moral responsibility of sponsors, and the public regulation and control by national States are put into question. The consequences of these changes represent serious threats to the rights of people included in these studies as well as disputable progress for public health.

Hemocianinas, una herramienta inmunológica de la biomedicina actual / Hemocyanins as immunostimulants

Hemocyanins, the giant oxygen transporter glycoproteins of diverse mollusks, are xenogenic to the mammalian immune system and they display a remarkable immuno-genicity. Therefore they are ideal non-specific immunostimulants to treat some types of cancer. They are used as an alternative therapy for superficial urinary bladder cancer (SBC), that has been traditionally treated with Bacillus Calmette-Guerin (BCG). In contrast to BCG, hemocyanins do not cause side-effects, making them ideal for long-term repetitive treatments. Hemocyanins have also been exploited as carriers to develop antibodies against hapten molecules and peptides, as carrier-adjuvants for cutting-edge vaccines against cancer, drug addiction, and infectious diseases and in the diagnosis of parasitic diseases, such as Schistosomiasis. The hemocyanin from Megathura crenulata, also known as keyhole limpet hemocyanin (KLH), has been used for over thirty years for the purposes described above. More recently, hemoc yanin from the Chilean mollusk Concholepas concholepas (CCH) has proved to be a reliable alternative to KLH, either as carrier protein, and as a likely alternative for the immunotherapy of SBC. Despite KLH and CCH differ significantly in their origin and structure, we have demonstrated that both hemocyanins stimulate the immune system of mammals in a similar way by inducing a potent Thl-polarized cellular and humoral response.

Purificação e caracterização de peptídeos antimicrobianos presentes na hemolinfa de Acanthoscurria rondoniae (Mygalomorphae, Theraphosidae) / Purification and characterization of antimicrobial peptides in the Haemilymph of the Acanthoscurria rondoniae spider( Mygalomorphae, Theraphosidae

Todos os organismos vivos, abrangendo desde microrganismos até plantas e animais, evoluíram de forma a desenvolver mecanismos para ativamente defender-se contra o ataque de patógenos. Peptídeos antimicrobianos são importantes componentes do sistema imune dos vertebrados e invertebrados podendo ser agrupados de acordo com suas propriedades químicas e estruturais. Podem agir na membrana plasmática de microorganismos formando poros na bicamada de fosfolipídeos ou serem internalizados e atuar sobre alvos intracelulares. Estudos sobre a biodiversidade de moléculas antimicrobianas nos vários grupos de artrópodes podem ser importantes para se entender o processo imunológico de uma maneira mais ampla, possibilitando compreender as relações existentes entre os vários sistemas, bem como sua origem, além de poder contribuir para o desenvolvimento e utilização de novas drogas para o uso na medicina e na agricultura. O objetivo deste trabalho foi verificar a produção de substâncias antimicrobianas, como observada em outros artrópodes, utilizando a aranha Acanthoscurria rondoniae como exemplo, através da purificação e caracterização de moléculas presentes na hemolinfa e caracterizando-as para um entendimento mais amplo dos processos envolvidos no sistema imune de aracnídeos e dos artrópodes em geral. Neste trabalho foram encontradas três frações com atividade antimicrobiana nos hemócitos que apresentaram massa molecular de 2.270,3 Da, 418,2 Da e 10.111,8 Da, respectivamente. Essas massas quando comparadas as encontradas em A. gomesiana, mostram similaridade com a gomesina, mygalina e acanthoscurrina, podendo indicar que as duas espécies apresentam as mesmas moléculas antimicrobianas em seus hemócitos. No plasma, foram encontradas seis frações, mais somente uma foi caracterizada, que apresentou massa molecular de 1.236,776 Da, recebeu o nome de rondonina em homenagem a espécie estudada. Pela primeira vez foi observado...

Influence of the pituitary gland on the immune response in young rats

The response of hypophysectomized (HYPOX) and sham-operated (S-HYPOX) female and male Wistar young rats (8 weeks old) to antigenic stimulation was compared. Humoral antigenic responses against hemocyanin were measured by ELISA. [3H]thyimidine incorporation into cultured splen cells was used to determine proliferative response to concanavalin A (ConA) or antigenic stimulation. Anti-hemocyanin serum titers in the HYPOX animals was about half of that observed in control S-HYPOX rats. Similarly, the cellular proliferative response was significantly decreased in HYPOX animals when compared to S-HYPOX rats; the blastogenic response to hemocyanin in UC rats (which did not receive the antigen injection) was close to zero. S-HYPOX control rats responded to direct ConA stimulation as UC controls. Body weight and the weight of pituitary target organs (adrenal, thyroid, ovary and testes) was about 1/4 of that of controls. Hypophysectomy also resulted in a striking reduction in spleen weight. These results indicate that the pituitary gland is involved in cellular and humoral immune regulation in young rats.

Acute schistosomiasis: clinical, diagnostic and therapeutic features

Three distinct syndromes caused by schistosomiasis have been described: cercarial dermatitis or swimmer's itch, acute schistosomiasis or Katayama fever, and chronic schistosomiasis. Complications of acute schistosomiasis have also been reported. The absence of a serological marker for the acute stage has hindered early diagnosis and treatment. Recently, an ELISA test using KLH (keyhole limpet haemocyanin) as antigen, has proved useful in differentiating acute from chronic schistosomiasis mansoni. Clinical and experimental evidence indicate that steroids act synergistically with schistosomicides in the treatment of Katayama syndrome. In this paper, clinical, diagnostic and therapeutic features of acute schistosomiasis are updated.

Permeabilidade vascular nas reacoes de hipersensibilidade cutanea basofilica. / Vascular permeability in cutaneous basophillic hypersensitivity

Reacoes de hipersensibilidade cutanea basofilica (HCB) provocadas em cobaias com ovoalbumina e hemocianina apresentaram aumento de permeabilidade vascular quando estes antigenos foram injetados localmente nas lesoes. Animais imunizados concomitantemente com os dois antigenos (ovoalbumina e hemocianina) apresentaram desgranulacao dos bosafilos apos injecao de hemocianina nas reacoes provocadas pela ovoalbumina.Quando estes antigenos alteraram a permeabilidade vascular nas reacoes de HCB, houve paralelamente extravasamento de proteinas plasmaticas na pele normal, embora em menor grau. Os resultados deste trabalho sugerem que as reacoes de HCD causadas pela ovoalbumina e apresentam caracteristicas semelhantes e que extrusao dos granulos dos basofilos nestas reacoes do tempo de desenvolvimento da lesao e da presenca de anticorpos especificos