Inhibition of retrovirus-induced syncytium formation by photoproducts of a brominated 1,8-naphthalimide compound.

A major disadvantage of conventional phototherapy is the requirement for the in situ delivery of stimulating photoenergy subsequent to the binding of photochemicals to target malignant cells, or virus-infected cells, or viruses. This drawback has resulted in considerable limitation in the use of photochemicals in photomedicine. To circumvent this problem, we have investigated the antiviral efficacy of a brominated 1,8-naphthalimide photocompound, termed LY66Br [3-bromo-4-(hexylamino)-N-hexyl-1,8-naphthalimide], which upon exposure to visible light at 420 nm generates independently of oxygen one or more stable antiviral molecular photoproducts (e.

Neutralization of HIV-1 and inhibition of HIV-1-induced syncytia by 1,8-naphthalimide photoactive compound.

The antiviral property of a newly designed class of 1,8-naphthalimide photochemical compounds was investigated. One such photoactive compound, 1,14-bis-(N-hexyl-3'-bromo-1,8'-naphthalimide-4'-yl)-1,4,11,14- tetraazatetradecane-5,10-dione (diED66Br), when activated to an excited state by visible light (420 nm), effectively neutralized the in vitro infectivity of human immunodeficiency virus (HIV-1). Light-activated diED66Br also inhibited syncytium formation induced by cells infected with HIV-1.

Inactivation of viruses with photoactive compounds.

The transmission of human immunodeficiency virus (HIV-1) and other enveloped virus by blood transfusion is a major concern. Photosensitive dyes such as hematoporphyrin derivative (HPD), dihematoporphyrin ether (DHE), benzoporphyrin derivatives (BPD), extended ring porphyrins, sapphyrins and texaphyrins, and various cyanines were used with viral cultures to test the feasibility of using those light-excitable dyes to kill virus. A photodynamic flow cell was used to irradiate viral suspensions or viral infected cells in culture media or in whole blood.

Preliminary studies of photoinactivation of human immunodeficiency virus in blood.

The transmission of human immunodeficiency virus (HIV) by blood or blood components is a major concern in blood banking. A photodynamic flow cell system was designed to inactivate cell-free HIV mixed with blood from a healthy donor. Blood containing 4 x 10(3) infectious units of HIV was treated with 10 and 20 micrograms per mL of commercially available dihematoporphyrin ether (DHE) per mL.

Protective qualities of mitochondrial and cytosolic fluorescent dyes against in vitro and in vivo infection by the Tulahuen strain of Trypanosoma cruzi.

This study demonstrates the binding of various fluorescent dyes (3,3' dihexyloxacarbocyanine iodide [DiOC6I], doxycycline [DOTC], rhodamine 123, and merocyanine 540) to infectious and intracellular forms of the Tulahuen strain of Trypanosoma cruzi. These dyes predominantly localize in mitochondria. Following treatment with DiOC6I and DOTC, both irradiated and nonirradiated samples showed dark toxicity to T.

Protection of NIH 3T3 cells from infection by trypomastigotes and sphaeromastigotes of Trypanosoma cruzi, Telahuen strain, by porphyrins in the presence and absence of light (630 and 690 nm).

The light and dark toxicities of naturally occurring and synthesized porphyrins were investigated for their potential to protect NIH 3T3 cells from infection with mammalian tissue culture-derived trypomastigotes of Trypanosoma cruzi. The fluorescent nucleic acid dye Hoechst 33342 was employed to trace T. cruzi intracellular development following porphyrin exposure with and without irradiation.

Photodynamic inactivation of simian immunodeficiency virus.

A photodynamic flow system employing a dihematoporphyrin ether (DHE) was tested for its ability to inactivate the in vitro infectivity of simian immunodeficiency virus (SICMac) at 630 +/- 5 nm with a light fluence of 5 J/cm2. Cell-free SIVMac was inactivated by photoactivated hematoporphyrin derivative in a dose-dependent fashion. Since SIVMac is closely related to human immunodeficiency virus type 2 (HIV-2) and we have previously reported the successful photodynamic inactivation of HIV-1 in cell-free medium as well as in whole human blood, this technology has the potential for the eradication of transfusion-associated acquired immunodeficiency diseases caused by the above-mentioned retroviruses.

Photodynamic therapy of viral contaminants with potential for blood banking applications.

A photodynamic method has been evaluated as a means of eradicating viral contaminants with the potential for rendering blood safe for transfusion. Herpes simplex virus type 1 (HSV-1) was tested under flowing conditions in culture media or in blood supplemented with the virus. Hematoporphyrin derivative was used as the sensitizer and was photoactivated with visible light at 630 nm and 5 J/cm2.

The selection of antigens for the diagnosis, prognosis and evolutive study of parasitic diseases.

The hypothesis is set forth that schizodeme (kDNA) typing of Trypanosoma cruzi, and possible other parasites, may be used to resolve the problem associated with the protean clinical manifestations of the disease. kDNA typing of T. cruzi clones may turn out to be useful in: (1) diagnosis; (2) prognosis; (3) production of species (generic) vaccines; (4) the study of autoimmunity.

Secretory/excretory antigens produced by tetrathyridia of Mesocestoides corti defined by SDS--PAGE and HPLC.

Antigens derived from culture medium in which metacestodes of Mesocestoides corti Hoeppli, 1925, had been maintained were studied by sodium-dodecyl-sulfate--polyacrylamide gel electrophoresis (SDS--PAGE) and high performance liquid chromatography (HPLC). By SDS--PAGE a minimum of 18 Coomassie-staining bands were discerned, of which 4 major bands and 4 major peaks by HPLC of similar molecular weights were observed. The HPLC eluate peaks were analyzed for antigenic activity in vitro by double diffusion in two dimensions, and in vivo in a rabbit.

Circulating antigens in infections of mice by tetrathyridia of Mesocestoides corti Hoeppli, 1925.

Two circulating antigens were detected in the serum of ICR/Timco female mice infected intraperitonealy with tetrathyridia of the cestode Mesocestoides corti Hoeppli, 1925. One circulating antigen appeared by day 2 postinfection (p.i.

Fine structure of the tegument of Mesocestoides tetrathyridia by scanning and transmission electron microscopy.

The tegumental surface of tetrathyridial stages of the tapeworm, Mesocestoides corti, was studied by scanning and transmission electron microscopy. Two structural types of microvilli were observed--blade-shaped or conical ones, and elongated, slender microvilli. The distribution and relative frequency of the two types of microvilli differs in different areas of the body surface.

Immunoglobulins on the surfaces of tetrathyridia of Mesocestoides corti Hoeppli 1925 (Cestoda), from laboratory infections of ICR mice.

7Sgamma2b antibody was detected, by fluorescein labeled antibodies, on the body surfaces and wall of excretory bladder of tetrathyridia of M. corti removed from the peritoneums of 5--24-week laboratory infections of ICR/TIMCO mice. 7Sgamma1, 7Sgamma2a, 7Sgamma3, IgM, IgA, and C3 were not found by use of the same techniques.

Antibodies sequestered in the liver granulomata of 8-week infections of CF1 mice by Schistosoma mansoni Sambon, 1907.

With our methods IgM, 7Sgamma1 and C3 were detected in the egg-induced liver granulomata of 8-week infections of CF1 mice by Schistosoma mansoni. It is speculated that, in addition to sequestration of antigens within these lesions by these antibodies, 7Sgamma1 may be associated with the Hoeppli phenomenon, and IgM in combination with C3 may be responsible for the ultimate death of the embryo or miracidium within the egg shell.

Delayed type hypersensitivity in guinea pig infected subcutaneously with Naegleria fowleri Carter.

A soluble fraction, derived from Naegleria fowleri trophozoites disrupted by freeze-thawing, was tested for antigenic properties. Intradermal injections of this preparation were administered to guinea pigs previously infected subcutaneously with viable N. fowleri.

Immunoglobulins attached to and in the integument of adult Schistosoma mansoni Sambon 1907, from first infection of CF mice.

7Sgamma2b antibody was found attached to and in the integument of adult Schistosoma mansoni removed from CF1 white mice. With the techniques used, IgA, IgM, 7Sgamma1, 7Sgamma2a, 7Sgamma3, and C3 complement were not found to be attached to the integumental surfaces. 7Sgamma2b does not seem to fix C3, and it is suggested this antibody may be acting in enhancing and blocking roles which protect the worms from the host.

Viruslike inclusions in the cecal epithelial cells of Pa agonimus kellicotti (Digenea, Troglotrematidae).

Rodlike or tubular inclusions are described from the cytoplasm and nuclear matrix of the cecal epithelial cells of Paragonimus kellicotti. These inclusions are 3.4 mu or more long, 350 A in diameter, and comprised of a wall of helically arranged subunits and a dense, possibly filar, central core.