An inactivated yellow fever 17DD vaccine cultivated in Vero cell cultures.

Yellow fever is an acute infectious disease caused by prototype virus of the genus Flavivirus. It is endemic in Africa and South America where it represents a serious public health problem causing epidemics of hemorrhagic fever with mortality rates ranging from 20% to 50%. There is no available antiviral therapy and vaccination is the primary method of disease control. Although the attenuated vaccines for yellow fever show safety and efficacy it became necessary to develop a new yellow fever vaccine due to the occurrence of rare serious adverse events, which include visceral and neurotropic diseases. The new inactivated vaccine should be safer and effective as the existing attenuated one. In the present study, the immunogenicity of an inactivated 17DD vaccine in C57BL/6 mice was evaluated. The yellow fever virus was produced by cultivation of Vero cells in bioreactors, inactivated with ß-propiolactone, and adsorbed to aluminum hydroxide (alum). Mice were inoculated with inactivated 17DD vaccine containing alum adjuvant and followed by intracerebral challenge with 17DD virus. The results showed that animals receiving 3 doses of the inactivated vaccine (2 µg/dose) with alum adjuvant had neutralizing antibody titers above the cut-off of PRNT50 (Plaque Reduction Neutralization Test). In addition, animals immunized with inactivated vaccine showed survival rate of 100% after the challenge as well as animals immunized with commercial attenuated 17DD vaccine.

Development of a whole cell pneumococcal vaccine: BPL inactivation, cGMP production, and stability.

Pneumococcal infections impose a large burden of disease on the human population, mainly in developing countries, and the current pneumococcal vaccines offer serotype-specific protection, but do not cover all pathogenic strains, leaving populations vulnerable to disease caused by non-vaccine serotypes. The pneumococcal whole cell vaccine is a low-cost strategy based on non-capsular antigens common to all strains, inducing serotype-independent immunity. Therefore, we developed the process for the cGMP production of this cellular vaccine. Initially, three engineering runs and two cGMP runs were performed in 60-L bioreactors, demonstrating the consistency of the production process, as evaluated by the growth curves, glucose consumption and metabolite formation (lactate and acetate). Cell recovery by tangential filtration was 92 ± 13 %. We optimized the conditions for beta-propiolactone (BPL) inactivation of the bacterial suspensions, establishing a maximum cell density of OD600 between 27 and 30, with a BPL concentration of 1:4000 (v/v) at 150 rpm and 4 °C for 30 h. BPL was hydrolyzed by heating for 2h at 37 °C. The criteria and methods for quality control were defined using the engineering runs and the cGMP Lots passed all specifications. cGMP vaccine Lots displayed high potency, inducing between 80 and 90% survival in immunized mice when challenged with virulent pneumococci. Sera from mice immunized with the cGMP Lots recognized several pneumococcal proteins in the extract of encapsulated strains by Western blot. The cGMP whole cell antigen bulk and whole cell vaccine product lots were shown to be stable for up to 12 and 18 months, respectively, based upon survival assays following i.p. challenge. Our results show the consistency and stability of the cGMP whole cell pneumococcal vaccine lots and demonstrate the feasibility of production in a developing country setting.

Efficacy and safety of two whole IgG polyvalent antivenoms, refined by caprylic acid fractionation with or without beta-propiolactone, in the treatment of Bothrops asper bites in Colombia.

The efficacy and safety of two whole IgG polyvalent antivenoms (A and B) were compared in a randomised, blinded clinical trial in 67 patients systemically envenomed by Bothrops asper in Colombia. Both antivenoms were fractionated by caprylic acid precipitation and had similar neutralising potencies, protein concentrations and aggregate contents. Antivenom B was additionally treated with beta-propiolactone to lower its anticomplementary activity. Analysing all treatment regimens together, there were no significant differences between the two antivenoms (A=34 patients; B=33 patients) in the time taken to reverse venom-induced bleeding and coagulopathy, to restore physiological fibrinogen concentrations and to clear serum venom antigenaemia. Blood coagulability was restored within 6-24 h in 97% of patients, all of whom had normal coagulation and plasma fibrinogen levels 48 h after the start of antivenom treatment. Two patients (3.0%) had recurrent coagulopathy and eight patients suffered recurrence of antigenaemia within 72 h of treatment. None of the dosage regimens of either antivenom used guaranteed resolution of venom-induced coagulopathy within 6 h, nor did they prevent recurrences. A further dose of antivenom at 6 h also did not guarantee resolution of coagulopathy within 12-24 h in all patients. The incidence of early adverse reactions (all mild) was similar for both antivenoms (15% and 24%; P>0.05).

A vanadium/aspirin complex controlled release using a poly(beta-propiolactone) film. Effects on osteosarcoma cells.

A delivery system for vanadium was developed using poly(beta-propiolactone) (PbetaPL) films. The release kinetics of a complex of vanadium (IV) with aspirin (VOAspi) was evaluated with films prepared from polymers of different molecular weights, as well as with variable drug load. A sustained release of vanadium over 7 days was achieved. The drug release kinetics depends on contributions from two factors: (a) diffusion of the drug; and (b) erosion of the PbetaPL film. The experimental data at an early stage of release were fitted with a diffusion model, which allowed determination of the diffusion coefficient of the drug. VOAspi does not show strong interaction with the polymer, as demonstrated by the low apparent partition coefficient (approximately 10(-2)). UMR106 osteosarcoma cells were used as a model to evaluate the anticarcinogenic effects of the VOAspi released from the PbetaPPL film. VOAspi-PbetaPL film inhibited cell proliferation in a dose-response manner and induced formation of approximately half of the thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. compared to that with free VOAspi in solution. The unloaded PbetaPL film did not generate cytotoxicity, as evaluated by cell growth and TBARS. Thus, the polymer-embedded VOAspi retained the antiproliferative effects showing lower cytotoxicity than the free drug. Results with VOAspi-PbetaPL films suggest that this delivery system may have promising biomedical and therapeutic applications.

Effect of beta-propiolactone treatment on the complement activation mediated by equine antisera

A reducao da ativacao do complemento atraves de uma alteracao do fragmento Fc das imunoglobulinas pela beta-propiolactona foi obtida em soros hiperimunes equinos antivirus rabico, venenos Bothrops e toxina difterica. Os resultados foram avaliados por teste de anafilaxia em cobaias, e comparados com aqueles obtidos com os mesmos soros purificados por precipitacao salina (sulfato de amonio), seguidos ou nao por digestao enzimatica com pepsina. Os niveis de pureza proteica foram para o soro antibotropico de 184,5 mg/g e 488,5 mg/g tratado pela beta-propiolactona e digeridos pela pepsina, respectivamente...(au)

Effect of beta-propiolactone treatment on the complement activation mediated by equine antisera.

Reduction of complement activation through an alteration of the Fc fragment of immunoglobulins by beta-propiolactone treatment was carried out in equine antisera raised against rabies virus, Bothrops venoms and diphtherial toxin. Results were evaluated by means of an anaphylactic test performed on guinea-pigs, and compared to the ones obtained with the same sera purified by saline precipitation (ammonium sulfate), followed or not by enzymatic digestion with pepsin. Protein purity levels for antibothropic serum were 184.5 mg/g and 488.5 mg/g in beta-propiolactone treated and pepsin-digested sera, respectively. The recovery of specific activity was 100% and 62.5% when using antibothropic serum treated by beta-propiolactone and pepsin digestion, respectively. The antidiphtherial and anti-rabies sera treated with beta-propiolactone and pepsin presented protein purity levels of 5,698 and 7,179 Lf/g, 16,233 and 6,784 IU/g, respectively. The recovery of specific activity for these antisera were 88.8%, 77.7%, 100% and 36.5%, respectively. beta-propiolactone treatment induced a reduction in complement activation, tested "in vivo", without significant loss of biological activity. This treatment can be used in the preparation of heterologous immunoglobulins for human use.

Influência da beta-propiolactona em testes laboratoriais hematológicos / Beta-propiolactone influence on haematological laboratory tests

Foram analisados os efeitos da beta-propiolactona em testes hematológicos. A incubaçäo do sangue com este agente resultou numa significante diminuiçäo da VHS e num aumento da concentraçäo da hemoglobina globular média e da contagem dos bastöes. A realizaçäo dos esfregaços logo após a adiçäo da droga evita este artefato. Os demais parâmetros permaneceram inalterados

Efeito da beta-propiolactona em testes iminológicos / The effect of beta-propiolactone on immunological tests

Foi estudada a interferência da beta-propiolactona (BPL) em testes imunológicos in vitro. As dosagens das imunoglobulinas, dos componentes C3 e C4 do complemento e a a pesquisa de fatores antinucleares näo foram afetadas pela presença deste agente químico. No entanto, foram observadas alteraçöes significativas nas determinaçöes do título do complemento hemolítico total (CH50), do percentual de linfócitos totais e de suas subpopulaçöes, e na pesquisa de células LE

Efeito da beta-propiolactona em exames bioquímicos. I: Laboratório de automaçäo / The effect of beta-propiolactone on biochemical tests. I: Automation laboratory

Foram estudados os efeitos da beta-propiolactona em testes bioquímicos, não sendo observadas alterações significantes em qualquer dos testes realizados.

Efeito da beta-propiolactona em exames bioquímicos. II: Laboratório de bioquímica / The effect of beta-propiolactone on biochemical tests. II: Biochemical laboratory

Foram estudados os efeitos resultantes da adição da beta-propiolactona (BPL) ao sangue total e soro nas dosagens de íons, na capacidade de fixação do ferro (TIBC), nas mucoproteínas, na eletroforese de proteínas e em algumas provas de funções hepáticas e pancreáticas. A adição desta substância ao sangue pode levar à hemólise, com conseqüentes alterações de análises bioquímicas. De todos os testes estudados apenas as dosagens de mucoproteínas nas alíquotas de soro contendo BPL apresentaram alterações com significado estatístico. Os autores recomendam o uso da BPL antes da realização das análises bioquímicas de rotina em soros de indivíduos infectados pelo HIV ou pertencentes a grupos de risco.