Protective effect of poly-2-vinylpyridine-N-oxide on susceptibility of silica-treated mice to experimental histoplasmosis

In vivo CRISPR/Cas9 targeting of fusion oncogenes for selective elimination of cancer cells

Fusion oncogenes (FOs) are common in many cancer types and are powerful drivers of tumor development. Because their expression is exclusive to cancer cells and their elimination induces cell apoptosis in FO-driven cancers, FOs are attractive therapeutic targets. However, specifically targeting the resulting chimeric products is challenging. Based on CRISPR/Cas9 technology, here we devise a simple, efficient and non-patient-specific gene-editing strategy through targeting of two introns of the genes involved in the rearrangement, allowing for robust disruption of the FO specifically in cancer cells. As a proof-of-concept of its potential, we demonstrate the efficacy of intron-based targeting of transcription factors or tyrosine kinase FOs in reducing tumor burden/mortality in in vivo models. The FO targeting approach presented here might open new horizons for the selective elimination of cancer cells.

The role of oxidative stress in diseases caused by mineral dusts and fibres: current status and future of prophylaxis and treatment

Inhalation of silica and asbestos fibres by humans can lead to fibrosis of the lung and cancer. Different mechanistic approaches, including oxidative stress, are used for prophylactic and therapeutic interventions to attenuate the fibrogenic and carcinogenic effects of these particles. Thus far, most of these therapeutic interventions have been only partly successful. A review of the mechanisms which are thought to be involved in mineral particle-induced toxicity and the relevant therapeutic interventions used to date to counteract these mechanisms, will help formulate better prophylactic and treatment intervention strategies in the future.

The role of oxidative stress in diseases caused by mineral dusts and fibres: current status and future of prophylaxis and treatment

Inhalation of silica and asbestos fibres by humans can lead to fibrosis of the lung and cancer. Different mechanistic approaches, including oxidative stress, are used for prophylactic and therapeutic interventions to attenuate the fibrogenic and carcinogenic effects of these particles. Thus far, most of these therapeutic interventions have been only partly successful. A review of the mechanisms which are thought to be involved in mineral particle-induced toxicity and the relevant therapeutic interventions used to date to counteract these mechanisms, will help formulate better prophylactic and treatment intervention strategies in the future.

Effect of silica treatment on resistance to Babesia rodhaini infection in immunized mice

The effect of silica treatment on the course of Babesia rodhaini infection was investigated in ICR mice pretreated with either a mixture of B. rodhaini parasitized red blood cell hemolysation-sonication (S) antigen and Propionibacterium acnes bacterin or P. acnes bacterin alone and not subjected to immunization. In the normal mice (non-immunized), the mean survival time was decreased by approximately 1 day when 5 mg per mouse of silica were intraperitoneally inoculated at 5 h before infection. In immunization with S antigen and P. acnes bacterin, all mice survived regardless of the dose of silica (15-25 mg per mouse) treatment. In contrast, in immunization with P. acnes bacterin alone, 3/10, 4/10 and 1/10 mice died of B. rodhaini, when inoculated with 15 mg per mouse, 20 mg per mouse and 25 mg per mouse of silica treatment 5 h before infection, respectively. These results suggest that peritoneal macrophages (M luminal diameter of), especially when activated non-specifically by P. acnes bacterin, play an important role in inhibiting multiplication of organisms at the early stage of infection and the mice immunized with S antigen were ready to quickly acquire an enhanced solid specific protection even if the function of M luminal diameter of was damaged by a high dose of silica treatment.

Functional analysis of Histoplasma capsulatum-reactive T-cell hybridomas

Activation of CD4+ T cells is a crucial step in the elimination of Histoplasma capsulatum yeast cells from tissues. However, only a limited amount of information exists concerning the immunobiology of H. capsulatum-reactive T cells that are CD4+. To facilitate the analysis of the functional activities of this T-cell subpopulation, we developed a panel of 10 murine T-cell hybridomas from splenocytes of immune C57BL/6 mice. All hybridomas reacted with monoclonal anti-CD4+ antibody and released interleukin-2 after stimulation with histoplasmin. Within 3 weeks, the reactivity of hybridomas to histoplasmin declined dramatically, yet the cells responded vigorously to yeast-phase preparations that were enriched for cytosol, cell wall, or cell membrane. Of 10 hybridomas studied, only one recognized heterologous fungal antigens. Responsiveness to yeast-phase antigens was restricted by I-Ab. We mapped determinants in cytosol and cell wall or cell membrane by the technique of one-dimensional T-cell immunoblotting. The patterns of responses of hybridomas to cytosol were nearly uniform. All hybridomas responded to two immunodominant regions in cytosol with masses ranging from less than or equal to 18 to 26 kilodaltons (kDa) and 35 to 39 kDa. All hybridomas tested responded to determinants in the cell wall or cell membrane preparation with masses of 35 to 39 kDa. These hybridomas provide a useful tool for defining yeast-phase antigens that trigger T-cell activation.

The chemical properties of silica particle surface in relation to silica-cell interactions

Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are thought to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.

Diagnosis and management of histoplasmosis

Histoplasmosis occurs throughout the world but is more common within the endemic areas of North America, particularly in fertile river valleys. Disease manifestations range from asymptomatic infection in the normal host with low-inoculum exposure to rapidly fatal, disseminated infection in the severely immunocompromised host, emphasizing the importance of cellular immunity in defense against Histoplasma capsulatum. Diagnosis depends on a high index of suspicion, knowledge of the clinical and epidemiologic features of the infection, and a thorough understanding of the uses and limitations of fungal cultural and serological laboratory procedures. Recently, a method has been developed for rapid diagnosis based on detection of a polysaccharide antigen in body fluids of patients with histoplasmosis. Amphotericin B remains the preferred treatment for more severe forms of histoplasmosis, particularly in the immunocompromised host, but oral treatment with ketoconazole or newer imidozoles appears to be effective in less severe infections in non-immunocompromised individuals.

An overview of macrophage-fungal interactions

A review of the literature (148 references) on the interactions of fungi with polymorphonuclear cells, monocytes and macrophages is presented. The interactions of Aspergillus species, Coccidioides immitis, Blastomyces dermatitidis, Histoplasma capsulatum, Cryptococcus neoformans, Candida albicans, and Candida species with human and experimental animal derived immune cells are examined in this overview. An effort has been made to present the reader with a comprehensive list of references with the intent of encouraging additional reading and research in this important area.