Search

Chlorpromazine may be capable of preventing HIV from infecting T cells especially when used in conjunction with zidovudine. The initial step in T cell infection occurs when the gp120 viral protein binds to the CD4 T cell receptor. This involves an electrostatic attachment that could be blocked by charged molecules such as chlorpromazine. Researchers studied several derivatives of chlorpromazine and found that 7,8-dioxo-chlorpromazine blocked the attachment of recombinant gp120 and also prevented infection of a T cell culture in the presence of zidovudine.

Isolation of a pentaene macrolide antibiotic (NSC-277813) from Streptomyces griseus(FCRC-21) fermentation broth is described. Using field desorption mass spectrometry and high resolution field desorption mass spectrometry on the intact and derivatized antibiotic and degradation products, the antibiotic was identified as fungichromin. The application of field desorption mass spectrometry in the identification of polyene antibiotics is discussed.

A reverse-phase high-performance liquid chromatographic (HPLC) method was developed for simultaneous potency determination of amphotericin A and amphotericin B in bulk amphotericin B preparations. This single, rapid, specific, and simple method can be used for qualitative and quantitative analyses and is proposed to replace a combination of cumbersome official tests presently in use. This new HPLC method employs an isocratic acidic phosphate buffer-methanol mixture in a reverse mode on an octadecylsilane-bonded silica column at ambient temperature, using UV detection at 313nm. Results obtained by HPLC compare favorably with the official assay results. During these studies, an apparent heptaenic component, not previously described, was detected in commercial amphotericin B preparations at concentrations ranging from ~6 to 14%.

The immunosuppressive effect of cyclosporin A (CsA) was studied on the anti-CD3 antibody (anti-CD3)- and concanavalin A (Con A)-induced activation of human T lymphocytes. A similar suppressive effect was observed in the Con A- and anti-CD3-induced proliferation as measured by the amount of [3H]thymidine incorporated on the third day of culture. When the cells were washed 30 min after activation with anti-CD3, the response was diminished and the CsA sensitivity was increased. In contrast, addition of interleukin-2 (IL-2) resulted in a significantly increased response and a decreased sensitivity. In cultures activated with anti-CD3, CsA treatment resulted in suppression of proliferation after 3 days and an enhancement after 5 days. This latter phenomenon was not seen in cultures treated with Con A. Removal of macrophages (MPH) abolished the proliferative response to anti-CD3. The addition of 10% MPH restored the response, while pretreatment of MPH with CsA diminished this ability. There were differences in the activation kinetics elicited by these two agents as reflected by the changes in membrane potential and the rate of IL-2 receptor (Tac) expression. The changes in the membrane potential (in the absence of CsA) seemed to be parallel with Tac expression and thymidine incorporation. CsA caused a hyperpolarization of the cell membrane. Both Con A and anti-CD3 brought about a strong depolarization which was blocked by the presence of CsA.

The effect of the polyene antibiotic nystatin, used in combination with several other antibiotics, on the membranes of Candida albicansSC#8169 (yeast) cells and of Chinese hamster ovary and 3T3 (mammalian) cells was investigated. It was concluded from determinations of the viability of the yeast cells and from measurements of deoxyribonucleic acid synthesis by the mammalian cells that nystatin acts synergistically with several antibiotics on yeast cells, but not on CHO and 3T3 cells. This selective action of nystatin may prove useful in chemotherapy.