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Fermented papaya preparation (FPP) (a product of yeast fermentation of Carica papaya Linn) is a food supplement. Studies in chronic and degenerative disease conditions (such as thalassemia, cirrhosis, diabetes and aging) and performance sports show that FPP favorably modulates immunological, hematological, inflammatory, vascular and oxidative stress damage parameters. Neuroprotective potential evaluated in an Alzheimer's disease cell model showed that the toxicity of the β-amyloid can be significantly modulated by FPP. Oxidative stress trigger apoptotic pathways such as the c-jun N-terminal kinase (JNK) and p38-mitogen activated protein kinase (MAPK) are preferentially activated by pro-inflammatory cytokines and oxidative stress resulting in cell differentiation and apoptosis. FPP modulated the H₂O₂-induced ERK, Akt and p38 activation with the reduction of p38 phosphorylation induced by H₂O₂. FPP reduces the extent of the H₂O₂-induced DNA damage, an outcome corroborated by similar effects obtained in the benzo[a]pyrene treated cells. No genotoxic effect was observed in experiments with FPP exposed to HepG2 cells nor was FPP toxic to the PC12 cells. Oxidative stress-induced cell damage and inflammation are implicated in a variety of cancers, diabetes, arthritis, cardiovascular dysfunctions, neurodegenerative disorders (such as stroke, Alzheimer's disease, and Parkinson's disease), exercise physiology (including performance sports) and aging. These conditions could potentially benefit from functional nutraceutical/food supplements (as illustrated here with fermented papaya preparation) exhibiting anti-inflammatory, antioxidant, immunostimulatory (at the level of the mucus membrane) and induction of antioxidant enzymes., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

We have recently proposed that lifestyle-related factors, screening and aging cannot fully account for the present overall growing incidence of cancer. In order to propose the concept that in addition to lifestyle related factors, exogenous environmental factors may play a more important role in carcinogenesis than it is expected, and may therefore account for the growing incidence of cancer, we overview herein environmental factors, rated as certainly or potentially carcinogenic by the International Agency for Research on Cancer (IARC). We thus analyze the carcinogenic effect of microorganisms (including viruses), radiations (including radioactivity, UV and pulsed electromagnetic fields) and xenochemicals. Chemicals related to environmental pollution appear to be of critical importance, since they can induce occupational cancers as well as other cancers. Of major concerns are: outdoor air pollution by carbon particles associated with polycyclic aromatic hydrocarbons; indoor air pollution by environmental tobacco smoke, formaldehyde and volatile organic compounds such as benzene and 1,3 butadiene, which may particularly affect children, and food pollution by food additives and by carcinogenic contaminants such as nitrates, pesticides, dioxins and other organochlorines. In addition, carcinogenic metals and metalloids, pharmaceutical medicines and cosmetics may be involved. Although the risk fraction attributable to environmental factors is still unknown, this long list of carcinogenic and especially mutagenic factors supports our working hypothesis according to which numerous cancers may in fact be caused by the recent modification of our environment.

Background: Despite multiple exposures to HIV-1, some individuals remain uninfected, and their peripheral-blood mononuclear cells (PBMC) are resistant to in-vitro infection by primary HIV-1 isolates. Such resistance has been associated with a homozygous 32-base-pair deletion (delta 32) in the C-C chemokine receptor gene CCR5. We examined other mutations of the CCR5 gene that could be associated with resistance to HIV-1 infection., Methods: We assessed the susceptibility of PBMC to in-vitro infection by HIV-1 isolates that use the CCR5 as the major coreceptor for viral entry in 18 men who had frequent unprotected sexual intercourse with a seropositive partner. We also did genotypic analysis of CCR5 alleles. One of the 18 exposed but uninfected men (who we refer to as ExU2) showed total resistance to in-vitro infection by CCR5-dependent viruses, and was found to carry a CCR5 delta 32 allele and a single point mutation (T-->A) at position 303 on the other allele. To find out whether the CCR5 mutation was restricted to ExU2's family or existed in the general population, we did genetic analyses of the CCR5 genotype in ExU2's father and sister and also in 209 healthy blood donors who were not exposed to HIV-1., Findings: The m303 mutation found in ExU2 introduced a premature stop codon and prevented the expression of a functional coreceptor. The family studies revealed that the m303 mutant allele was inherited as a single mendelian trait. Genotype analysis showed that three of the 209 healthy blood donors were heterozygous for the mutant allele., Interpretation: We characterise a new CCR5 gene mutation, present in the general population, that prevents expression of functional coreceptors from the abnormal allele and confers resistance to HIV-1 infection when associated to the delta 32 CCR5 mutant gene.

Levels of natural antibodies (NAb) with high anti-trinitrophenyl (TNP) activity are increased during human immunodeficiency virus (HIV) infection. The aim of the present study was to examine the anti-HIV effect of natural anti-TNP antibodies, as well as that of their internal image, TNP antigen, on HIV infection in vitro. The results obtained with anti-TNP antibodies, as assessed by syncytia formation, were variable, although they demonstrated an inhibitory effect. In contrast, using RT activity assay plus evaluation of syncytia formation and the viral cytopathic effect, we found that bovine serum albumin (BSA) bearing different TNP groups was able to inhibit HIV infection of peripheral mononuclear cells and T4 cell lines without affecting cell metabolism or proliferation. BSA alone was devoid of activity; the antiviral effect depended on TNP substitution of the BSA molecule, and passage through an anti-TNP immunoadsorbent abolished this effect. The mechanism by which TNP exerts this antiviral effect is unclear. Antigenic epitopes may be shared by HIV and TNP, since monoclonal antibodies directed against various HIV proteins reacted with TNP in an enzyme immunoassay. TNP-BSA, however, did not bind to the CD4 receptor.

Lymph nodes obtained from 14 macaques sacrificed at early time points following experimental inoculation with simian immunodeficiency virus were analyzed by in situ hybridization for virus load and virus cellular tropism. The lymph nodes presented a remarkably high viral load during the early phase of infection, as viral RNA was detected in as many as 2% of lymph node cells 1 week after inoculation. At this stage, macrophages and T4 lymphocytes were identified by combined immunohistochemistry and in situ hybridization as the target cells of the virus. Simian immunodeficiency virus-positive macrophages concentrated in the subcapsular sinuses, suggesting an entry of infected cells via the afferent lymphatics. A shift in the pattern of viral infection was observed at 2 weeks after inoculation, with a concentration of viral RNA in the germinal centers of the developing lymphoid follicles. Follicular dendritic cells were found to be the major target of the virus at this stage. Follicular dendritic cells were associated with high levels of viral RNA but little or no detectable viral DNA, suggesting that the virus was present mostly in the form of viral particles trapped at the cell surface. Follicular dendritic cell-associated virus persisted at high levels for 2 months before subsiding, indicating that follicular dendritic cells constituted a major reservoir of the virus during the early stages of simian immunodeficiency virus infection.

To elucidate the initial pathogenic events in lymphoid organs, the major reservoir of virus in HIV infection, follow-ups of viral load, pathological changes and target cells were performed in the rhesus macaque SIVmac251 model and in the cat FIV model. Lymph nodes (LN) obtained from animals sacrificed at early time points following experimental inoculation were analysed by in situ hybridization for virus load and by combined immunohistochemistry and in situ hybridization for virus cellular tropism. In the SIV model, the LN presented a high viral load at 7 days post inoculation (p.i.); at this stage, macrophages and T4 lymphocytes were identified as the target cells of the virus. A shift in the pattern of viral infection was observed at 2 weeks p.i., with a concentration of viral RNA in follicular dendritic cells (FDC) in the germinal centres of the developing lymphoid follicles. This FDC-associated virus persisted at high levels for 2 months p.i. in the FIV model, the number of infected cells detected in LN was very low compared with that found in the SIV model, and a similar role played by FDC was found.

7 individuals who were negative for HIV-1 antibody in a licensed serum enzyme immunoassay (EIA) were positive in a urine EIA and western blot (WB). Follow-up in individuals by use of a cell-mediated immune response showed 1 positive and 1 negative for HIV-1 peptide reactivity. In a second study, 4 out of 5 subjects positive by urine EIA and indeterminate or negative by serum WB were HIV-1 peptide positive in the cell-mediated immune test. Comparison of cell-mediated responses with urine antibody responses may help to resolve discrepant HIV-1 results.

In order to investigate the role of germ cells in the sexual transmission of immunodeficiency virus (HIV), spermatozoa from healthy HIV-seronegative men were incubated in vitro with HIV1. After washing, they were cocultured with peripheral blood leukocytes from seronegative blood donors. Reverse transcriptase assays and p24 antigen tests were performed in culture supernatants. Electron microscopy examination of these HIV-incubated spermatozoa was carried out, as well as the search for CD4 molecules on their surface. Although virus bound to and seemed to enter spermatozoa despite the absence of detectable CD4 epitopes on their surface, no replication of HIV was apparent. However, HIV particles on the surface of spermatozoa were capable of infecting CD4 T lymphocytes. Present results would seem to preclude artificial insemination between an HIV-seropositive man and an HIV-seronegative woman.

In contrast to others groups, we have previously shown that N-linked glycans of HIV-1 and HIV-2 envelope glycoproteins do not play a major role in the gp-CD4 interaction. In order to clarify these inconsistencies, we investigated the role of N-glycans in the interaction of SIV with the CD4 receptor. The inhibition of binding of radiolabeled SIV envelope glycoprotein (gp140) to CD4+ cells by increasing concentrations of soluble CD4 shows that the interaction occurred with high affinity (K0.5 = 1.4 x 10(-8) M). Treating SIV gp140 with endo F-N glycanase, with or without detergent, reduced its molecular mass from 140 to 75 KDa. This indicates that N-glycan represents about 50% of molecular mass of the glycoprotein. Interestingly, the fact that deglycosylated SIV gp140 as its native form bound significantly and specifically to CD4 receptor indicates that oligosaccharides of SIV gp140 are not required for the gp-CD4 interaction.

Early encephalopathy was studied in rhesus macaques in the first month following intravenous (i.v.) infection with SIV-mac-251. Histopathological analysis of brain tissues showed slight gliosis, associated with perivascular infiltrates and occasional glial nodules. Immunophenotyping of brain tissue showed microgliosis with expression of MHC class II molecule and macrophage infiltration associated with a few lymphocytes. At the early stage of infection, most infected cells were perivascular, suggesting that infiltrating cells are the main route of entry of the virus into the brain. Using combined immunochemistry and in situ hybridization, it was shown that these infected perivascular cells were mostly macrophages. Later, SIV infected a limited number of cells expressing the same CD68 monocyte/macrophage/microglia marker. Using different genome probes, hypotheses concerning SIV RNA expression during early brain infection were tested. It was shown that the latent brain infection was not due to a complete transcription block, but rather to productive replication of SIV at a low level in a small number of target cells in the brain. Injection of SIV by the intracerebral (i.c.) route induced the same slight encephalitis as observed in i.v. inoculated animals. The very small number of infected cells found around the site of i.c. inoculation suggests that resident microglia are poorly susceptible to infection by SIV.

To establish an animal model of AIDS, two different "wild" or "adapted" HIV2 Rod and Eho strains were cultivated on monkey cells from different species (baboons, cynomolgus, Rhesus monkeys). Five different available strains were then injected both by intravenous (i.v.) and intracerebral (i.c.) route into ten Rhesus monkeys. Seven animals seroconverted between days 13 and 230. Reverse transcriptase activity in the lymphocyte culture supernatants was detectable in six of the seven animals that seroconverted, and in one animal that remained seronegative. Lymphopenia and a decrease in the CD4+ cell counts were observed in eight animals. One animal, inoculated with HIV2-Rod "wild type," developed a severe cachexia, with dyspnea, and associated neurological symptoms 150 days after inoculation. This animal was sacrificed on day 220. Pathological examination showed typical lesions of actinomycetes infection in the lungs and in the meninges. Another monkey had significant weight loss associated with lymphadenopathies and pancytopenia. These results suggest that in vivo replication of HIV2 in Rhesus monkeys may induce clinical symptoms of immune deficiency. This method is reproducible and may provide a good model for AIDS.

To investigate the mechanism of simian immunodeficiency virus (SIV) entry into the central nervous system (CNS) and the initial events leading to neuropathogenesis, SIV replication was studied by in situ hybridization in the CNS of 5 Rhesus macaques at 7 days, 1, 2, and 3 months after SIV intravenous inoculation. CNS infection was found to be a frequent and early event, as SIV was detected in the CNS of all the animals studied and as early as 7 days postinoculation. At the earliest stage, the infection localized mainly to perivascular cells. Using combined immunohistochemistry and in situ hybridization, infected cells were shown to express the CD68 marker, suggesting that infected mononuclear phagocytes crossing the blood-brain barrier represent the main source of virus in the CNS. Early viral replication coincided with neuropathologic changes, consisting in gliosis, perivascular infiltrates and rare glial nodules. Immunophenotyping of brain tissue showed that increased macrophage infiltration, microglial reactivity and MHC class II induction occurred within the first week of infection, indicating a possible immunopathologic mechanism in early CNS pathogenesis.

Comparison of HIV1Bru and HIV2Rod external envelope glycoprotein sequences enabled us to select ten highly conserved peptide sequences. The corresponding peptides were chemically synthesized, then coupled to bovine serum albumin before injection in rabbits. Although all peptides were immunogenic, only antibodies directed against peptides P1 (amino acid residues 33-55), P22 (418-462), P8 (487-508) and P21 (487-534) were able to interact with significant affinity (K0.5 about 10(-6) to 10(-8) M) with the native glycoprotein by radioimmunoassay. Noteworthy was the capacity of anti-P1 antibodies to also recognize the glycoprotein of HIV2. Anti-peptide antibodies were tested for their ability to interfere with the gp120-CD4 interaction, membrane fusion and virus replication. Preincubation of gp120 with antibodies directed to the region previously described as the putative CD4-binding site, P22 (418-462), did not abolish gp120 binding to CD4-positive cells.

The relevance, previously suggested by some authors, of anti-nef antibody detection as an early marker of human immunodeficiency virus (HIV) infection was examined with a sensitive liquid phase radioimmunoassay by investigating: (1) the kinetics of appearance of anti-nef-antibodies in a set of 77 longitudinal sera collected from 12 HIV-infected donors at the time of seroconversion; and (2) nef serology in a population of 32 HIV seropositive and three seronegative hemophiliacs and their seronegative or seropositive sexual partners. The results obtained showed that anti-nef antibodies could not be detected in the sera tested independently of the appearance of antibodies specific to HIV structural proteins. Thus, the detection of anti-nef antibodies appears to be of little diagnostic value.

Tetracycline analogs were evaluated for anti-HIV activity in CEM cells; minocycline and doxycycline were the most active of these in inhibiting the virus-induced cytopathic effect between 7 and 14 days post-infection. The active concentrations (0.3-1.5 micrograms/ml) were devoid of toxicity in uninfected cultures. Virus production, however, was not inhibited, indicating a dissociation between protection against cell death and suppression of virus growth. These protected cells could be maintained in culture for 6-7 weeks, even in the absence of the compounds. After that period, virus production ceased and cells could then be cultivated for several months without loss of viability or reappearance of virus production. As HIV stocks produced in the presence of tetracycline analogs were unable to induce cell death, we suggest that the cytopathogenicity of HIV may be due in some cases to the presence of tetracycline-sensitive contaminating microorganisms.

In a study of the transmissibility of human immunodeficiency virus (HIV) in haemophilic and non-haemophilic children living together in a boarding school in France, half of the haemophilic children had seroconverted by the end of a 3-year study period. By contrast none of the non-haemophilic children seroconverted. All children had had close casual contact, some of them for several years. Hepatitis B virus (HBV) markers detected in all polytransfused haemophiliacs were found in 4 of 20 control children in the school, whereas all healthy youngsters living with their families were HBV negative. This study adds support to the theory that transmissibility of HIV among casual contacts is low and that there is no reason to exclude HIV-antibody carriers from communities.

Newly synthesized dipyrido [4,3-b] [3,4-f] indole compounds have a structural similarity with the DNA intercalating agents ellipticines (pyrido-carbazoles). The procedure of synthesis of these compounds allows the addition of a lateral chain in position 1 of the nucleus. Comparison is made between different substitutions and the resulting cytotoxic and antitumoral effects. The most active compound of the serie (1-gamma-diethyl amino propyl amino)-5-methyl-dipyrido [4,3-b] [3,4-f] indole (called here BD40) protects mice against L1210 leukemia. At the non-toxic dose of 20 mg/kg, particularly, a single infection of this compound given one day after inoculation of 10(5) L1210 cells resulted in an increased life span of 69 per cent with one survivor at 60 days. A combination of cyclophosphamide and BD40 had a synergic effect on the life span of L1210 inoculated mice. The antitumoral action of these drugs may be linked to their intercalative action upon biding to DNA.

The cytostatic effect of various derivatives of 2-nitro-naphthofurans has been determined in vitro on L1210 leukemia cells. A recently described new bio-assay (Discotest) was used, which consists in plating the cells in soft agarose and placing on top of the agarose layer a paper disc soaked with the compound to be tested. The halo of inhibition of colony formation which results from diffusion of the compound is proportional to the logarithm of the compound concentration. The most active derivatives were the 2-nitro-7-methoxy and 2-nitro-8-methoxy-naphtho[2,1-b] furans which are known to be highly bactericidal and protozoocidal.

We described here the characteristics of the Reverse Transcriptase activity associated with the Lymphadenopathy Associated Virus ( LAV ). A critical concentration of non ionic detergent, all four deoxyribonucleosides triphosphates and the divalent cation Mg2+ are required for optimal endogenous enzyme activity. The endogenous reaction product is digested by DNase and not by RNase and its synthesis is only slightly inhibited by actinomycin D. Exogenous reactions are optimal using poly A oligo dT12 -18 or poly Cm oligo dG12 -18 as template primer and Mg2+ as divalent cation. This enzyme can be distinguished from other cellular DNA polymerases activities and from Terminal deoxynucleotidyl Transferase (TdT) by purification from LAV infected T lymphocytes using phosphocellulose column.

Reverse transcriptase activity of lymphadenopathy associated virus was assayed after exposure to various standard chemical disinfectants. 25% ethanol or 1% glutaraldehyde should prove sufficient to disinfect medical instruments, and 0.2% sodium hypochlorite for cleaning floors and benches. 0.1% formalin is too slow to be recommended.

IgG antibodies to lymphadenopathy-associated virus ( LAV ) were found by a specific enzyme-linked immunosorbent assay in 18/48 (37.5%), patients with acquired immunodeficiency syndrome, 38/51 (74.5%) patients with lymphadenopathy syndrome, 8/44 (18%) homosexual men without lymphadenopathy, and 1/100 unselected blood donors.

Lymphadenopathy associated virus is inactivated by heating at 56 degrees C for 30 min, and is not inactivated by 2 X 10(5) rad gamma irradiation or 5 X 10(3) J/m2 ultraviolet irradiation.

We studied the sensitivity of human herpesvirus-6 (HHV-6) to 4 antiviral drugs known to be effective in the treatment of infections with other human herpesviruses and human immunodeficiency virus. HHV-6 was grown in peripheral blood lymphocytes, and virus multiplication was quantified by evaluation of the cytopathic effect by molecular hybridization and indirect immunofluorescence assay. The 50% and 90% inhibitory concentrations (IC50 and IC90) were determined for each drug. The results obtained by the 3 different quantification techniques were found to correlate, and enabled us to conclude that HHV-6 replication was readily inhibited by foscarnet or ganciclovir. In contrast, inhibition of HHV-6 replication was observed only at high concentrations of acyclovir, and was not detected at the tested concentrations of zidovudine.

Various aspects of membrane changes in cells transformed by oncogenic viruses are briefly described and discussed. Emphasis is made on changes recently observed in the hydrophobic portion of plasma membrane with the freeze-etching technique. The hypothesis is put forward that other changes seen at the surface of transformed cells are caused by a primary event occuring in proteins of the hydrophobic area.

Twenty-six sera containing anti-HIV antibodies from individuals with AIDS, AIDS-related complex, lymphadenopathy syndrome, or from seropositive individuals without clinical symptoms, were tested for the presence of natural autoantibodies (NAb) to actin, DNA, tubulin, thyroglobulin, albumin, myosin and TNP-BSA. Sera from 22 seronegative individuals at high risk for HIV infection were also examined. NAb titres to all these antigens were found to be elevated in both groups as compared to the titres in pooled normal human sera. The most prevalent NAb were those of the IgG class directed against TNP found in high titre in seropositive individuals. On the basis of the above results, sera from 50 anti-HIV-positive and 67 anti-HIV-negative individuals were tested for IgG antibody activity against a panel of protein antigens with different degrees of TNP substitution. The greater the TNP substitution, the higher the titres of IgG antibodies detected in anti-HIV-positive sera. Antibody titres in seronegative individuals at high risk for HIV infection were independent of the degree of TNP substitution. In almost all cases, the highest titres of IgG anti-TNP antibodies were found in anti-HIV-positive sera from individuals with clinical manifestations.