Inosine Acedoben Dimepranol promotes an early and sustained increase in the natural killer cell component of circulating lymphocytes: A clinical trial supporting anti-viral indications.

Inosine Acedoben Dimepranol (IAD), licensed for the treatment of cell-mediated immune deficiencies associated with viral infections, has been reported to impact a variety of immune parameters both in vitro and in vivo. Here we report the results from a clinical trial where multiple lymphocyte subsets - CD19+ B cells, CD3+ T cells, CD4+ T-helper cells, FoxP3/CD25/CD127 regulatory T cells (Tregs), CD3-/CD56+ NK cells, and CD3+/CD56+ NKT cells - were, together with serum immunoglobulins and IgG subclasses, followed during 14days of IAD administration to ten healthy volunteers; these selected from 27 individuals pre-screened in vitro for their capacity to respond to IAD as gauged by increases in the percentage of Treg and/or NKT cells arising in PHA-stimulated cultures. While a transient spike and dip in Treg and T-helper fractions, respectively, was noted, the outstanding consequence of IAD administration (1g po, qds) was an early and durable rise in NK cells.

Clinical and Immunological Analysis of Cutaneous Leishmaniasis before and after Different Treatments.

Amastigotes from L. (L.)amazonensis (La), L.

Antigens from Leishmania amastigotes inducing clinical remission of psoriatic arthritis.

A first generation vaccine (AS100-1) was manufactured with protein from four cultured Leishmania species, which proved to be effective in the treatment of psoriasis. A single blind trial on 3,132 psoriasis patients revealed 508 (16.2%) subjects with psoriatic arthritis (PsA) that received AS100-1 antigens.

Purified proteins from Leishmania amastigotes-induced delayed type hypersensitivity reactions and remission of collagen-induced arthritis in animal models.

A treatment preparation composed of purified Leishmania (L) antigenic fractions (AS210) induced linear delayed type hypersensitivity (DTH) reactions over a 1-40 microg dose range, in guinea pigs. When a DBA-1 mouse collagen induced arthritis (CIA) model was used to compare AS210 treatment against: a polyvalent vaccine (AS110-1), a monovalent vaccine (AS110-2) and placebo, the AS210 treated mice had the least amount of forepaw inflammation and the lowest mean arthritis scores (MAS). When MAS for day(s) 1-40 were analyzed using one way ANOVA, statistically significant (P < 0.

Lymphocyte subsets in peripheral blood of patients with psoriasis before and after treatment with leishmania antigens.

Peripheral blood mononuclear cells (PBMC) collected from subjects prior to treatment and post-treatment with a vaccine composed of leishmania antigens were analyzed by flow cytometry. Upon analysis, it was noticed that lymphocyte subsets (LS) varied with psoriasis area and severity index (PASI) range (1-10, 11-20 and 21-72). Pre-treatment absolute values of gated LS were as follows.

Isolation of Leishmania amastigote protein fractions which induced lymphocyte stimulation and remission of psoriasis.

A first generation polyvalent vaccine (AS100(1)) was manufactured with protein from several cultured leishmania species, which proved to be effective in the treatment of psoriasis. To determine the effective factor, a single blind trial with four monovalent second generation vaccines (AS100(2)) was done in 26 subjects, which also resulted in remission of psoriasis. AS100(2) vaccines were further purified, resulting in seven chromatography fractions (AS200) per species.

Antigens from Leishmania amastigotes induced clinical remission of psoriasis.

While injecting volunteers in Venezuela with a vaccine for prevention of leishmaniasis, we observed 100% clinical remission of a psoriatic lesion in one subject. Subsequently, the vaccine (AS100) was evaluated in psoriatic patients with an open label, single center study. The study was conducted in 2,770 subjects and included plaque (79%), guttate (10%), plaque and guttate (10%), palm/plantar, erythrodermia, inverse, plaque and arthritis and nail psoriasis.

Overview of some biomedical research projects in tropical medicine conducted at the Instituto Venezolano de Investigaciones Cientificas.

The Instituto Venezolano de Investigaciones Cientificas (IVIC) is a government-funded multidisciplinary academic institution dedicated to research, development and technology in many areas of knowledge. Biomedical projects and publications comprise about 40% of the total at IVIC. In this article, we present an overview of some selected research and development projects conducted at IVIC which we believe contain new and important aspects related to malaria, ancylostomiasis, dengue fever, leishmaniasis and tuberculosis.

Epidemiologic characterization of American cutaneous leishmaniasis in an endemic region of eastern Venezuela.

The status of American cutaneous leishmaniasis was investigated from 1985 to 1991 to provide an epidemiologic characterization of the disease in Bergantin, a rural community in the northeastern part of Anzoátegui State, Venezuela. The study revealed the presence of the infection during the period analyzed, with an average incidence of 50.2 cases per 10,000 inhabitants and this number has increased 1.

Comparison of chagasic and non-chagasic myocardiopathies by ELISA and immunoblotting with antigens of Trypanosoma cruzi and Trypanosoma rangeli.

Trypanosoma cruzi associated myocardiopathy, or Chagas disease, continues to be a serious problem in Venezuela, for which there is neither a vaccine nor a cure. In order to learn more about the humoral immune response to trypanosomal antigens, and to try to identify dominant antigens, we used ELISA and immunoblotting to study the reactivity of sera from patients with chagasic and non-chagasic myocardiopathies, against surface and secreted proteins from T. cruzi and T.

A carrageenan hydrogel stabilized colloidal gold multi-enzyme biosensor electrode utilizing immobilized horseradish peroxidase and cholesterol oxidase/cholesterol esterase to detect cholesterol in serum and whole blood.

The preparation of two immobilized enzyme electrodes is described. One electrode contains horseradish peroxidase absorbed to colloidal gold and deposited on a glassy carbon electrode along with cholesterol oxidase entrapped in a carrageenan hydrogel. The second electrode also includes cholesterol esterase entrapped in the carrageenan.

A comparison of the molecular biology of trypanosomes and leishmaniae, and its impact on the development of methods for the diagnosis and vaccination of leishmaniasis and Chagas disease.

Our main interest have focused on Chagas disease and Leishmaniasis, working in the areas of: 1--The molecular biology of Trypanosomes and Leishmaniae, and 2--The immunology of Chagas disease, cutaneous leishmaniasis and visceral leishmaniasis. In this article we summarize the work realized in the last 20 years in the Immunobiology Laboratory at the IVIC with special emphasis in the development of a vaccine against leishmaniasis that is being currently used in a field trial in human beings of the endemic area of Guatire, Miranda State, Venezuela.

Colloidal gold as a biocompatible immobilization matrix suitable for the fabrication of enzyme electrodes by electrodeposition.

Glucose oxidase, horseradish peroxidase, xanthine oxidase, and carbonic anhydrase have been adsorbed to colloidal gold sols with good retention of enzymatic activity. Adsorption of xanthine oxidase on colloidal gold did not result in a change in enzymatic activity as determined by active site titration with the stoichiometric inhibitor pterin aldehyde and by measurement of the apparent Michaelis constant (K'(M)). Gold sols with adsorbed glucose oxidase, horseradish peroxidase, and xanthine oxidase have also been electrodeposited onto conducting matrices (platinum gauze and/or glassy carbon) to make enzyme electrodes.

Electrochemical enzyme immunoassay for detection of toxic substances.

Sensors that provide reliable, rapid measurement of toxic substances are needed to solve significant human health and safety problems. We developed a new biosensor design that combines the advantages of immunoassay with electrochemical response. We established that this enzyme-linked immunosensor measures toxic substances in biological samples.

Comparison of colloidal gold electrode fabrication methods: the preparation of a horseradish peroxidase enzyme electrode.

In order to prepare biosensing electrodes which respond to hydrogen peroxide, horseradish peroxidase has been adsorbed to colloidal gold sols and electrodes prepared by deposition of these enzyme-gold sols onto glassy carbon using three methods: evaporation, electrodeposition and electrolyte deposition. In the latter method the enzyme-gold sol is applied to the surface of a glassy carbon disk electrode followed by an equal volume of 2 mM CaCl2. The electrolyte causes the sol to precipitate on the electrode surface, producing an immobilized enzyme electrode.

Variability of Trypanosoma cruzi epimastigote surface antigens with changes in the temperature of the cultures.

Trypanosoma cruzi epimastigotes changed their pattern of surface proteins when the temperature of growth rose from 30 degrees C to 34 degrees C. Challenge of mice with blood-form trypomastigotes produced high parasitemias when animals were immunized with surface proteins from epimastigotes cultured at 30 degrees C and with Nonidet P-40-extracted epimastigotes pellets cultured at 34 degrees C. However, low parasitemias were recorded after immunization with surface proteins from epimastigotes cultured at 34 degrees C or Nonidet P-40-extracted epimastigotes pellets at 30 degrees C.

Splenocyte membrane changes and immunosuppression during infection and reinfection with Trypanosoma cruzi.

Antisera to epi- and trypomastigote forms of Trypanosoma cruzi were used to detect trypanosome antigens on the surface of lymphocytes from infected mice. Only the anti-trypomastigote serum could recognize antigens expressed transiently on the splenocyte membranes from infected animals. The number or structural configuration of Concanavalin A receptors was similarly affected and a clear correlation was seen between these two types of membrane changes and the immunosuppression to mitogens and SRBC presented by the infected mice.

Differential growth requirements of several Leishmania spp. in chemically defined culture media.

17 strains of Leishmania from 4 species: brasiliensis, mexicana, donovani and garnhami have been continually cultured at 26 degrees C, in the absence of proteins, in a medium containing salts, glucose, D-ribose, 2-deoxyribose, hemin, tricine, HEPES, 34 amino acids and intermediates of amino acid metabolism, 23 vitamins, 6 nucleotides and tetrahydrofolic acid. A wide variation in growth requirements was observed among leishmaniae which permitted the preparation of different minimum culture media for each Leishmania spp. Virulence of parasites was maintained after 30 passages in these chemically defined media.

Preparation and activity of carbonic anhydrase immobilized on porous silica beads and graphite rods.

Techniques for the immobilization of bovine carbonic anhydrase (BCA) on porous silica beads and graphite are presented. Surface coverage on porous silica beads was found to be 1.5 x 10(-5) mmol BCA/m(2), and on graphite it was 1.

Trypanosoma cruzi: growth requirements at different temperature in fetal bovine serum or peptide supplemented media.

An enriched synthetic medium with low molecular weight peptides allows Trypanosoma cruzi epimastigotes to grow at 26-37 C. Using this medium, the growth requirements of T. cruzi were compared at different temperatures.

Protein and nucleotide contamination of bovine liver catalase used in culture medium explains growth of Trypanosoma cruzi.

Commercially available bovine liver catalase has been used to supplement chemically defined medium for growth of Trypanosoma cruzi. The protein extract was found to be contaminated with 25 to 30 protein bands as well as DNA and RNA polymers.

Immunization of hamsters with TLCK-killed parasites induces protection against Leishmania infection.

Hamsters immunized with N-p-tosyl-L-lysine-chloromethyl ketone TLCK-treated L. brasiliensis brasiliensis (LB) from culture, infected with LB amastigotes presented: a gradual increase in T and B cell responsiveness to mitogens by lymph node lymphocytes, and an increased response to concanavalin A with no changes for dextran sulphate and pokeweed mitogen in splenocytes. Absence of parasites in lymph nodes after 6 weeks post-infection and a nodule 4 times smaller than that of infected control animals.

Differential effect of culture epimastigotes and blood-form trypomastigotes on normal mouse splenocyte responsiveness to mitogens.

Blood form trypomastigotes of the Y strain of T. cruzi, produced a strong inhibition of the blastogenic response to T and B cell mitogens, of the C3H/He, C57BL/6 and BALB/cJ strains of mice, while culture epimastigotes of the Y strain kept in a medium that allows parasite growth at 26 degrees, 30 degrees, 34 degrees and 37 degrees C produced a strong stimulatory effect that was even higher than the effect of the mitogens alone. Both the inhibitory or the stimulatory effects were dose-dependent.