65 research outputs found

    H. pylori-infection and antibody immune response in a rural Tanzanian population

    Get PDF
    BACKGROUND: Helicobacter pylori (H. pylori) infection is ubiquitous in sub-Saharan Africa, but paradoxically gastric cancer is rare. METHODS: Sera collected during a household-based survey in rural Tanzania in 1985 were tested for anti-H. pylori IgG and IgG subclass antibodies by enzyme immunoassay. Odds ratios (OR) and confidence intervals (CI) of association of seropositivity with demographic variables were computed by logistic regression models. RESULTS: Of 788 participants, 513 were aged ≤17 years. H. pylori seropositivity increased from 76% at 0–4 years to 99% by ≥18 years of age. Seropositivity was associated with age (OR 11.5, 95% CI 4.2–31.4 for 10–17 vs. 0–4 years), higher birth-order (11.1; 3.6–34.1 for ≥3(rd )vs. 1(st )born), and having a seropositive next-older sibling (2.7; 0.9–8.3). Median values of IgG subclass were 7.2 for IgG1 and 2.0 for IgG2. The median IgG1/IgG2 ratio was 3.1 (IQR: 1.7–5.6), consistent with a Th2-dominant immune profile. Th2-dominant response was more frequent in children than adults (OR 2.4, 95% CI 1.3–4.4). CONCLUSION: H. pylori seropositivity was highly prevalent in Tanzania and the immunological response was Th2-dominant. Th2-dominant immune response, possibly caused by concurrent bacterial or parasitic infections, could explain, in part, the lower risk of H. pylori-associated gastric cancer in Africa

    Radiosensitisation of U87MG brain tumours by anti-epidermal growth factor receptor monoclonal antibodies

    Get PDF
    As epidermal growth factor receptor (EGFR) has been reported to be a radiation response modulator, HER inhibitors are regarded to act as potential radiosensitisers. Our study examined the role of nimotuzumab and cetuximab both, the two monoclonal antibodies (mAbs) to EGFR, as radiosensitisers in a murine glioma model in vivo. Co-administration of both the antibodies with radiation increased the radiosensitivity of U87MG, resulting in a significant delay of subcutaneous (s.c.) tumour growth. Furthermore, the addition of antibodies to the radiation decreased brain tumour sizes and is inhibited by 40–80% the increased tumour cell invasion provoked by radiotherapy, although promoted tumour cell apoptosis. Whereas nimotuzumab led to a reduction in the size of tumour blood vessels and proliferating cells in s.c. tumours, cetuximab had no significant antiangiogenic nor antiproliferative activity. In contrast, cetuximab induced a more marked inhibition of EGFR downstream signalling compared with nimotuzumab. Moreover, both antibodies reduced the total number of radioresistant CD133+ cancer stem cells (CSCs). These results were encouraging, and showed the superiority of combined treatment of mAbs to EGFR and radiation over each single therapy against glioblastoma multiforme (GBM), confirming the role of these drugs as radiosensitisers in human GBM. In addition, we first showed the ability of mAb specifics against EGFR to target radioresistant glioma CSC, supporting the potential use in patients

    Malignant lymphomas (ML) and HIV infection in Tanzania

    Get PDF
    \ud HIV infection is reported to be associated with some malignant lymphomas (ML) so called AIDS-related lymphomas (ARL), with an aggressive behavior and poor prognosis. The ML frequency, pathogenicity, clinical patterns and possible association with AIDS in Tanzania, are not well documented impeding the development of preventive and therapeutic strategies. Sections of 176 archival formalin-fixed paraffin-embedded biopsies of ML patients at Muhimbili National Hospital (MNH)/Muhimbili University of Health and Allied Sciences (MUHAS), Tanzania from 1996-2001 were stained for hematoxylin and eosin and selected (70) cases for expression of pan-leucocytic (CD45), B-cell (CD20), T-cell (CD3), Hodgkin/RS cell (CD30), histiocyte (CD68) and proliferation (Ki-67) antigen markers. Corresponding clinical records were also evaluated. Available sera from 38 ML patients were screened (ELISA) for HIV antibodies. The proportion of ML out of all diagnosed tumors at MNH during the 6 year period was 4.2% (176/4200) comprising 77.84% non-Hodgkin (NHL) including 19.32% Burkitt's (BL) and 22.16% Hodgkin's disease (HD). The ML tumors frequency increased from 0.42% (1997) to 0.70% (2001) and 23.7% of tested sera from these patients were HIV positive. The mean age for all ML was 30, age-range 3-91 and peak age was 1-20 years. The male:female ratio was 1.8:1. Supra-diaphragmatic presentation was commonest and histological sub-types were mostly aggressive B-cell lymphomas however, no clear cases of primary effusion lymphoma (PEL) and primary central nervous system lymphoma (PCNSL) were diagnosed. Malignant lymphomas apparently, increased significantly among diagnosed tumors at MNH between 1996 and 2001, predominantly among the young, HIV infected and AIDS patients. The frequent aggressive clinical and histological presentation as well as the dominant B-immunophenotype and the HIV serology indicate a pathogenic association with AIDS. Therefore, routine HIV screening of all malignant lymphoma patients at MNH is necessary to enable comprehensive ARL diagnosis and formulation of preventive and therapeutic protocols.\u

    Perceptions of HIV cure research among people living with HIV in Australia

    Get PDF
    Participation in HIV cure-related clinical trials that involve antiretroviral treatment (ART) interruption may pose substantial individual risks for people living with HIV (PLHIV) without any therapeutic benefit. As such, it is important that the views of PLHIV are considered in the design of HIV cure research trials. Examining the lived experience of PLHIV provides unique and valuable perspectives on the risks and benefits of HIV cure research. In this study, we interviewed 20 PLHIV in Australia about their knowledge and attitudes toward clinical HIV cure research and explored their views regarding participation in HIV cure clinical trials, including those that involve ART interruption. Data were analysed thematically, using both inductive and deductive coding techniques, to identity themes related to perceptions of HIV cure research and PLHIV’s assessment of the possible risks and benefits of trial participation. Study findings revealed interviewees were willing to consider participation in HIV cure research for social reasons, most notably the opportunity to help others. Concerns raised about ART interruption related to the social and emotional impact of viral rebound, including fear of onward HIV transmission and anxiety about losing control. These findings reveal the ways in which PLHIV perspectives deepen our understanding of HIV cure research, moving beyond a purely clinical assessment of risks and benefits in order to consider the social context

    Borrelia Burgdorferi Induces a Type I Interferon Response During Early Stages of Disseminated Infection in Mice

    Get PDF
    BACKGROUND: Lyme borrelia genotypes differ in their capacity to cause disseminated disease. Gene array analysis was employed to profile the host transcriptome induced by Borrelia burgdorferi strains with different capacities for causing disseminated disease in the blood of C3H/HeJ mice during early infection. RESULTS: B. burgdorferi B515, a clinical isolate that causes disseminated infection in mice, differentially regulated 236 transcripts (P \u3c 0.05 by ANOVA, with fold change of at least 2). The 216 significantly induced transcripts included interferon (IFN)-responsive genes and genes involved in immunity and inflammation. In contrast, B. burgdorferi B331, a clinical isolate that causes transient skin infection but does not disseminate in C3H/HeJ mice, stimulated changes in only a few genes (1 induced, 4 repressed). Transcriptional regulation of type I IFN and IFN-related genes was measured by quantitative RT-PCR in mouse skin biopsies collected from the site of infection 24 h after inoculation with B. burgdorferi. The mean values for transcripts of Ifnb, Cxcl10, Gbp1, Ifit1, Ifit3, Irf7, Mx1, and Stat2 were found to be significantly increased in B. burgdorferi strain B515-infected mice relative to the control group. In contrast, transcription of these genes was not significantly changed in response to B. burgdorferi strain B331 or B31-4, a mutant that is unable to disseminate. CONCLUSIONS: These results establish a positive association between the disseminating capacity of B. burgdorferi and early type I IFN induction in a murine model of Lyme disease

    In vitro toxicokinetics and analytical toxicology of three novel NBOMe derivatives - Phase I and II metabolism, plasma protein binding, and detectability in standard urine screening approaches studied by means of hyphenated mass spectrometry

    Get PDF
    Purpose Toxicokinetic studies are essential in clinical and forensic toxicology to understand drug-drug interactions, influence of individual polymorphisms, and elimination routes, as well as to evaluate targets for toxicological screening procedures. An N-(2-methoxybenzyl)-substituted phenethylamines (NBOMe analogues) intake has been associated with severe adverse reactions including deaths. 1-(1-Benzofuran-5-yl)-N-[(2-methoxyphenyl)methyl]propan-2-amine (5-APB-NBOMe), 2-(8-bromo-2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b′]difuran-4-yl)-N-[(5-chloro-2-ethoxyphenyl)methyl]ethan-1-amine (2C-B-FLY-NB2EtO5Cl), and 2-(8-bromo-2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b′]difuran-4-yl)-N-[(2-methoxyphenyl)methyl]ethan-1-amine (2C-BFLY-NBOMe) are three emerging NBOMe analogues, which have encountered on the drugs of abuse market. So far, their toxicokinetic data are completely unexplored. Methods The study included mass spectrometry-based identification of phase I and II metabolites following exposure to the terminally differentiated human hepatocellular carcinoma cells (HepaRG). The determination of enzymes involved in the major phase I/II metabolic steps and determination of plasma protein binding (PPB) was done. Finally, the evaluation of the toxicological detectability by different hyphenated mass spectrometry techniques in standard urine screening approaches (SUSAs) was investigated. Results The compounds were extensively metabolized in HepaRG cells mainly via O-dealkylation, hydroxylation, glucuronidation, and combinations thereof. CYP1A2, 2D6, 2C8, 2C19, and 3A4, were involved in the initial reactions of all investigated compounds. Glucuronidation of the phase I metabolites – when observed - was mainly catalyzed by UGT1A9. The PPB of all compounds was determined to be > 85%. Only the high-resolution mass spectrometry-based SUSA allowed detection of all compounds in rat urine but only via metabolites. Conclusions The toxicokinetic data provided by this study will help forensic and clinical toxicologists to reliably identify these substances in case of abuse and/or intoxication and will allow them a thorough risk assessment

    Gravitational Lensing from a Spacetime Perspective

    Full text link
    • …
    corecore