The Study of Host Immune Responses Elicited by the Model Murine Hookworms Nippostrongylus brasiliensis and Heligmosomoides polygyrus.

Hookworm infections (Necator americanus or Ancylostoma duodenale) represent a major neglected tropical disease, affecting approximately 700 million people worldwide, and can cause severe morbidity due to the need for these worms to feed on host blood. N. brasiliensis and H. polygrus, both rodent parasites, are the two most commonly employed laboratory models of experimental hookworm infection. Both parasites evoke type 2 immune responses, and their use has been instrumental in generating fundamental insight into the molecular mechanisms of type-2 immunity and for understanding how the immune response can control parasite numbers. Here we provide a complete set of methods by which to investigate the natural progression of infection and the host immunological responses in the lung and intestine of H. polygyrus- and N. brasiliensis-infected mice. Detailed information is included about the most important parasitological and immunological measurements to perform at each time point. © 2017 by John Wiley & Sons, Inc.

Propagating wave pattern on a falling liquid curtain.

A regular pattern of surface waves is observed on a liquid curtain falling from a horizontal, wetted tube, maintained between two vertical wires. Since the upper boundary is not constrained in the transverse direction, the top of the curtain enters a pendulum-like motion, when the flow rate is progressively reduced, coupled to the propagation of curtain undulations, structured as a checkerboard. This structure is formed by two patterns of propagating waves. In some sense, these propagating patterns replace the stationary pattern of liquid columns observed at a lower flow rate. Measurements of phase velocity, frequency, and wavelength are reported. The data are in agreement with a simple dimensional argument suggesting that the wave velocity is proportional to the surface tension divided by the mass flux of liquid per unit length. This scaling is also that followed by the fluid velocity at the so-called transonic point, i.e., the point where the fluid velocity equals that of sinuous waves. We finally discuss the implications of these results for the global stability of liquid curtains.

PFG NMR measurements of flow through porous media: effects of spatial correlations of the magnetic field and the velocity field.

Used for a long time for diffusion studies, PFG NMR techniques are now widely used to study flow through porous media. We discuss here the effects of the magnetic field inhomogeneities and the finite gradient pulse duration in this case. We propose a statistical model based on spatial correlations of the magnetic field and velocity field and as far as we can, we draw practical conclusions on the PFG NMR measurements conditions.

Tunneled hemodialysis catheter survival: comparison of radiologic and surgical implantation.

Cuffed, tunneled hemodialysis catheters (caths) are often implanted in the operating rooms (OR) by surgeons or by interventional radiologists in radiology suites (RS). Comparative outcome studies between OR and RS placed caths are few and tend to favor the specialty of the authors. In this longitudinal study, we monitored cath survival in patients while awaiting maturation of their fistulae, and compared outcomes between OR and RS placement. A total of 95 caths were placed in 50 patients between July 1996 and July 1999. Radiologically placed caths had a shorter primary patency duration than OR placed caths (80 +/- 40 days vs. 100 +/- 31 days, p = 0.04) and a lower primary patency rate at 120 days than OR placed caths (42% vs. 67%, p = 0.04). Cumulative infection rate per 1,000 catheter days was higher in RS than OR cases (3.8 Vs 2.2, p = 0.09), whereas mean sepsis free duration was shorter in RS than OR (60 +/- 45 days vs. 88 +/- 40 days, p = 0.02). The risk of infection was 1.7 times greater in RS than OR cases (chi-square = 6.4, p = 0.01). The RS placed caths also had a higher rate of primary nonfunction (31% vs. 8.3%, p = 0.04) and bleeding complications (42% vs. 17%, p = 0.04), but significantly shorter procedure scheduling time than OR cases (1.1 +/- 0.3 days vs. 2.5 +/- 0.6 days, p < 0.0001). In conclusion, radiologically placed caths seem to have higher rates of infection, bleeding, and functional failure but shorter scheduling time than surgically placed caths. Discussions are under way to improve the survival of RS placed caths at our affiliated hospitals.

Pulsed field gradient NMR measurements of probability distribution of displacement under flow in sphere packings.

In this work we used the PFG NMR displacement technique to investigate the transport of water particles under flow through a model porous media. Using different sizes of sphere for monodisperse glass sphere packings, we measured the probability distribution of displacement for mean displacements ranging from 0.08 to 7.3 times the characteristic length of the porous media. We observed, therefore, the transition between the velocity probability distribution and the Gaussian-shaped distribution of classical dispersion.

Antibodies to varicella-zoster virus modulate antigen distribution but fail to induce viral persistence in vitro.

Varicella-zoster virus (VZV) persists in human sensory ganglia. One of the hypotheses to explain the induction or the maintenance of VZV latency is that it could be promoted by the immune response itself. It is known that in the case of viruses which bud off the infected cell membrane, virus-specific antibodies can induce antigenic modulation, i.e., spatial redistribution of viral antigens and modulation of their synthesis. To determine whether antigenic modulation occurs during VZV infection in vitro and could possibly be involved in viral persistence, we have grown infected cells in the presence of anti-VZV antibodies either transiently or permanently. The distribution of immune complexes and viral proteins was then analyzed. In transient immunomodulation experiments, the distribution of one or more viral antigens was modified not only in the cytoplasmic membranes but also in the cytoplasm and nucleoplasm of infected cells. When infected cells were kept permanently in the presence of antibodies, the same pattern of redistribution of immune complexes was observed and the localization of internal viral glycoproteins was significantly modified. However, antibodies did not prevent the lytic effect of infection; they altered neither the infectious virus yield nor the Western immunoblot pattern of viral proteins, suggesting that immunomodulation is not the primary effector of viral persistence.