23 research outputs found

    Hydroxychloroquine is much less active than chloroquine against chloroquine-resistant Plasmodium falciparum, in agreement with its physicochemical properties.

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    The 4-aminoquinoline drug hydroxychloroquine (HCQ) is reported to be as active as chloroquine (CQ) against falciparum malaria, and less toxic. Existing prophylactic regimens for areas where there is CQ-resistant malaria recommend CQ with proguanil as an alternative where none of the three preferred regimens (atovaquone-proguanil, doxycycline or mefloquine) is thought suitable. In such cases, toxicity is likely when CQ-proguanil is administered to persons being treated for autoimmune disease with daily HCQ. The question therefore arises whether in such circumstances HCQ could effectively replace the CQ component of the prophylactic combination. We confirmed similar activity of CQ and HCQ against CQ-sensitive Plasmodium falciparum, but found that whereas HCQ in vitro was 1.6 times less active than CQ in a CQ-sensitive isolate, it was 8.8 times less active in a CQ-resistant isolate. The result can also be predicted from an analysis of the physicochemical properties of CQ and HCQ. To give limited protective effect similar to 300 mg CQ base weekly against CQ-resistant P. falciparum would demand daily doses of HCQ above the recommended safe level. These observations contraindicate the use of HCQ in prophylaxis or treatment of CQ-resistant falciparum malaria. Where CQ-proguanil prophylaxis is the only option available in a patient on high-dose HCQ treatment, visiting a CQ-resistant area, replacement of the anti-inflammatory regimen by a daily CQ course at a suitable dose should be considered

    Introduction of modifying agents into skin by electroporation

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    A method of modifying epidermis for transport of a material by electroporation includes applying to epidermis an agent that, upon entry into the epidermis, will modify the epidermis to thereby cause and altered rate of transport of a material across the epidermis. Typically, the altered rate will be an increased rate of transport. The epidermis is electroporated, whereby at least a portion of the modifying agent enters the electroporated epidermis, thereby modifying the epidermis to cause an altered rate of transport of a material across the epidermis. In another embodiment, the modifying agent can modify the epidermis to enable measurement and/or monitoring of physiological conditions or change within or beneath the epidermis. The modifying agents can also be employed to facilitate discharge of fluids from within an organism, such as by providing pathways for discharge of fluids from a tumor. Examples of modifying agents include: oxidizing agents; reducing agents; particles, such as optical indicator beads or beads that include drugs to be released into tissue; electrically-charged particles or molecules; etc. Materials that can be transported by the method of the invention include, for example, proteins, nucleic acids, electrically charged molecules or particles, microorganisms suitable for immunization, etc. Also, tissues other than skin can be employed in the method of the invention

    Breaking the one antibody–one target axiom

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    Studies at the interface of chemistry and biology have allowed us to develop an immunotherapeutic approach called chemically programmed antibodies (cpAbs), which combines the merits of traditional small-molecule drug design with immunotherapy. In this approach, a catalytic antibody catalyzes the covalent conjugation of a small molecule or peptide to the active site of the antibody, effectively recruiting the binding specificity of the conjugated molecule to the antibody. In essence, this technology provides the tools for breaking the “one antibody–one target axiom” of immunochemistry. Our studies in this area have focused on using the chemistry of the well studied aldolase catalytic antibodies of which mAb 38C2 is a member. Previously, we explored reversible assembly of cpAbs available through diketone chemistry. In this article, we explore a unique proadapter assembly strategy wherein an antibody 38C2-catalyzed transformation unveils a reactive tag that then reacts to form a stable covalent bond with the antibody. An integrin α(v)β(3) antagonist was synthesized with the designed proadapter and studied using human breast cancer cell lines MDA-MB-231 and MDA-MB-435. We demonstrate that this approach allows for (i) the effective assembly of cpAbs in vitro and in vivo, (ii) selective retargeting of 38C2 to integrin α(v)β(3) expressing breast cancer cell lines, (iii) intracellular delivery of cpAbs into cells, (iv) dramatically increased circulatory half-life, and (v) substantial enhancement of the therapeutic effect over the peptidomimetic itself in animal models of breast cancer metastasis. We believe that this technology possesses potential for the treatment and diagnosis of disease
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