Chloroquine is a 9-aminoquinoline known since 1934. Apart from its well-known antimalarial effects, the drug has interesting biochemical properties that might be applied against some viral infections. Chloroquine exerts direct antiviral effects, inhibiting pH-dependent steps of the replication of several viruses including members of the flaviviruses, retroviruses, and coronaviruses. Its best-studied effects are those against HIV replication, which are being tested in clinical trials. Moreover, chloroquine has immunomodulatory effects, suppressing the production/release of tumour necrosis factor alpha and interleukin 6, which mediate the inflammatory complications of several viral diseases. We review the available information on the effects of chloroquine on viral infections, raising the question of whether this old drug may experience a revival in the clinical management of viral diseases such as AIDS and severe acute respiratory syndrome, which afflict mankind in the era of globalisation.

/pdf/effects-of-chloroquine-on-viral-infections-an-old-drug-3b3wv4o3ga.pdf

Effects of chloroquine on viral infections: an old drug against today's diseases

Hydrogels for protein delivery.

This review describes the diverse array of pathways and molecular targets that are used by viruses to elude immune detection and destruction. These include targeting of pathways for major histocompatibility complex-restricted antigen presentation, apoptosis, cytokine-mediated signaling, and humoral immune responses. The continuous interactions between host and pathogens during their coevolution have shaped the immune system, but also the counter measures used by pathogens. Further study of their interactions should improve our ability to manipulate and exploit the various pathogens.

Viral Subversion of the Immune System

Telomeres are nucleoprotein caps flanking DNA. They are shortened by cell division and oxidative stress and are lengthened by the enzyme telomerase and DNA exchange during mitosis. Short telomeres induce cellular senescence. As an indicator of oxidative stress and senescence (2 processes thought to be fundamental to aging), telomere length is hypothesized to be a biomarker of aging. This hypothesis has been tested for more than a decade with epidemiologic study methods. In cross-sectional studies, researchers have investigated whether leukocyte telomere length (LTL) is associated with demographic, behavioral, and health variables. In prospective studies, baseline LTL has been used to predict mortality and occasionally other adverse health outcomes. Conflicting data have generated heated debate about the value of LTL as a biomarker of overall aging. In this review, we address the epidemiologic data on LTL and demonstrate that shorter LTL is associated with older age, male gender, Caucasian race, and possibly atherosclerosis; associations with other markers of health are equivocal. We discuss the reasons for discrepancy across studies, including a detailed review of methods for measuring telomere length as they apply to epidemiology. Finally, we conclude with questions about LTL as a biomarker of aging and how epidemiology can be used to answer these questions.

/pdf/telomere-length-in-epidemiology-a-biomarker-of-aging-age-4mo2s2f14c.pdf

Telomere Length in Epidemiology: A Biomarker of Aging, Age-Related Disease, Both, or Neither?

Fertilization calcium waves are introduced, and the evidence from which we can infer general mechanisms of these waves is presented. The two main classes of hypotheses put forward to explain the ge...

/pdf/calcium-at-fertilization-and-in-early-development-4f8xabt5ha.pdf

Calcium at fertilization and in early development.

Porcine alveolar macrophages (AMphi) are the dominant cell type that supports the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in vivo and in vitro. In order to determine the characteristics of the virus-receptor interaction, the attachment of PRRSV to cells was examined by using biotinylated virus in a series of flow cytometric assays. PRRSV bound specifically to AMphi in a dose-dependent manner. Binding of PRRSV to AMphi increased gradually and reached a maximum within 60 min at 4 degrees C. By confocal microscopy, it was shown that different degrees of PRRSV binding exist and that entry is by endocytosis. Virus uptake in vesicles is a clathrin-dependent process, as it was blocked by the addition of cytochalasin D and co-localization of PRRSV and clathrin was found. Furthermore, by the use of two weak bases, NH4Cl and chloroquine, it was demonstrated that PRRSV uses a low pH-dependent entry pathway. In the presence of these reagents, input virions accumulated in large vacuoles, indicating that uncoating was prevented. These results indicate that PRRSV entry into AMphi involves attachment to a specific virus receptor(s) followed by a process of endocytosis, by which virions are taken into the cell within vesicles by a clathrin-dependent pathway. A subsequent drop in pH is required for proper virus replication.

Entry of porcine reproductive and respiratory syndrome virus into porcine alveolar macrophages via receptor-mediated endocytosis.

receptors were found in the oocytes, fertilized zygotes as well as cleaved embryos at all stages studied. The pattern and distribution of the receptor staining in the oocytes changed gradually from a diffuse granular patchy one at the germinal vesicle (GV) stage to a reticular and predominantly peripheral one through the metaphase I and metaphase II (MII) stages. After fertilization, the distribution changed gradually to both, peripheral and central in the zygotes and early 2‐4-cell embryos and predominantly perinuclear in the 6‐8cell embryos. Furthermore, an overall increase in the staining intensity was observed from GV to MII stage oocytes and from zygotes to 6‐8-cell embryos. We also studied the spatial distribution of the receptor in detail by constructing three-dimensional images from the serial optical sections obtained on the CLSM. Peculiar peripheral aggregates of receptor clusters were noted in the MII stage oocytes, zygotes and some blastomeres from early cleaved embryos. Finally, Western blots performed on the extracts of 72 in-vitro matured oocytes and 50 spare cleavage stage embryos showed positive bands at ~260 kDa. These findings coincide with and thus possibly represent the dynamic changes occurring in the cellular Ca 2F release systems

/pdf/presence-and-dynamic-redistribution-of-type-i-inositol-1-4-5-1fcurfuouv.pdf

Presence and dynamic redistribution of type I inositol 1,4,5-trisphosphate receptors in human oocytes and embryos during in-vitro maturation, fertilization and early cleavage divisions.

This paper reports the results and the interpretation of rheological experiments on and diffusion measurements of fluorescent polymer chains in solutions and gels of dextran (dex) derivatized with methacrylate (ma) groups. We illustrate the use of confocal scanning laser microscopy (CSLM) and fluorescence recovery after photobleaching (FRAP) to study the mobility of large molecules in polymer systems. The main aim was to understand the influence of the polymer network in the gels on the mobility of large molecules. Therefore we measured the diffusion coefficients before and after cross-linking the dextran methacrylate (dex−ma) chains. Increasing the dex−ma concentration did not spectacularly increase the sterical hindrance by the dex−ma network. However, the sterical hindrance did become significantly stronger when the size of the diffusing probe and the degree of ma substitution were increased. The mobility of the probes decreased when the dex−ma gels became more elastic. However, the decrease in the dif...

Diffusion of Macromolecules in Dextran Methacrylate Solutions and Gels As Studied by Confocal Scanning Laser Microscopy

Telomere length versus hormonal and bone mineral status in healthy elderly men.

The organization of proteins in space and time is essential to their function. To accurately quantify subcellular protein characteristics in a population of cells with regard for the stochasticity of events in a natural context, there is a fast-growing need for image-based cytometry. Simultaneously, the massive amount of data that is generated by image-cytometric analyses, calls for tools that enable pattern recognition and automated classification. In this article, we present a general approach for multivariate phenotypic profiling of individual cell nuclei and quantification of subnuclear spots using automated fluorescence mosaic microscopy, optimized image processing tools, and supervised classification. We demonstrate the efficiency of our analysis by determination of differential DNA damage repair patterns in response to genotoxic stress and radiation, and we show the potential of data mining in pinpointing specific phenotypes after transient transfection. The presented approach allowed for systematic analysis of subnuclear features in large image data sets and accurate classification of phenotypes at the level of the single cell. Consequently, this type of nuclear fingerprinting shows potential for high-throughput applications, such as functional protein assays or drug compound screening. © 2009 International Society for Advancement of Cytometry

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/cyto.a.20807

P. Van Oostveldt

Papers

Entry of porcine reproductive and respiratory syndrome virus into porcine alveolar macrophages via receptor-mediated endocytosis.

Presence and dynamic redistribution of type I inositol 1,4,5-trisphosphate receptors in human oocytes and embryos during in-vitro maturation, fertilization and early cleavage divisions.

Diffusion of Macromolecules in Dextran Methacrylate Solutions and Gels As Studied by Confocal Scanning Laser Microscopy

Telomere length versus hormonal and bone mineral status in healthy elderly men.

High content image cytometry in the context of subnuclear organization