In vitro infection of human macrophages with human T-cell leukemia virus type 1

The tropism of the human T-cell leukemia virus type 1 (HTLV-1) for the cells of monocyte-macrophage lineage was evaluated by the coculture of blood monocyte-derived macrophages, with irradiated cells of HTLV-1 producing cell lines MT2 or C91/PL. The susceptibility to HTLV-1 was assessed by the detection of viral DNA using the polymerase chain reaction method. HTLV-1 gene expression in the cells was detected using in situ hybridization and by immunofluorescent staining of viral antigen. The presence of type C virus-like particles detected by electron microscopy and the ability to infect normal cord blood lymphocytes demonstrated that the infected macrophages produced infectious virus. These results indicate that human macrophages are susceptible in vitro to productive HTLV-1 infection, and thus might be involved in the pathogenesis of HTLV-1-related diseases.     

The Many Faces of CD4+ T Cells: Immunological and Structural Characteristics

As a major arm of the cellular immune response, CD4⁺ T cells are important in the control and clearance of infections. Primarily described as helpers, CD4⁺ T cells play an integral role in the development and activation of B cells and CD8⁺ T cells. CD4⁺ T cells are incredibly heterogeneous, and can be divided into six main lineages based on distinct profiles, namely T helper 1, 2, 17 and 22 (Th1, Th2, Th17, Th22), regulatory T cells (Treg) and T follicular helper cells (Tfh). Recent advances in structural biology have allowed for a detailed characterisation of the molecular mechanisms that drive CD4⁺ T cell recognition. In this review, we discuss the defining features of the main human CD4⁺ T cell lineages and their role in immunity, as well as their structural characteristics underlying their detection of pathogens.     

Microstructure of milk gel and cheese curd observed using cryo scanning electron microscopy and confocal microscopy

Cryo scanning electron microscopy (cryo SEM) and confocal laser scanning microscopy (CLSM) were used to visualise changes in the microstructure of milk, rennet-induced gel and curd during the manufacture of Cheddar cheese. Our results show that cryo preservation did not alter the microstructure of the sample when it was fixed by rapid freezing in slush liquid nitrogen due to the formation of amorphous ice. Artefacts such as the formation of ice crystals could be observed in samples when immersed directly into liquid nitrogen (−196 °C) at atmospheric pressure. These ice crystals changed the shape of sample pores increasing their size to >20 μm. The etching time, thickness of gold coating, accelerating voltage and type of detector used for cryo SEM observation were varied in order to minimise the formation of such artefacts and optimise conditions for imaging. Chains and clusters of casein micelles and fat globules were best observed in the gel and the cooked curd when the samples were freeze fractured and etched for 30 min, coated with a mixture of gold and palladium alloy approximately 6 nm thick at −140 °C and observed using a backscattered electron detector at 15 kV. The structure of the gel, curd and cheese was also observed using CLSM. Spherical fat globules were mostly present in the serum pores of the gel prepared from unhomogenised milk but were found embedded in the aggregated chains of the casein network within the gel prepared from homogenised milk when observed using CLSM. The porosity measurements obtained using cryo SEM were similar to those obtained using CLSM. These two complementary techniques can potentially be used to assist studies for the control of cheese texture and functionality.     

Quantification and kinetics of the residual brine generation during ham and shoulder pile salting

Salting is one of the most important stages of the traditional process of cured ham manufacturing. During pile salting a saturated brine is formed and drips through the orifices located at the bottom of the salting containers.

The objective of the present work was to quantify the released brine in the ham manufacturing industry in Spain and to relate the brine generation with the salt gained by hams in the process.

The total released brine during ham and shoulder salting in Spain was determined theoretically and from the experimental values obtained from the industry (around 38,000 metric tons in 2002). In addition to that, an easy method for the estimation of the NaCl gained by hams and shoulders was developed by using the measurements of the released brine (the estimated NaCl gained differed 3.5% from the experimental data).     

Rayleigh scattering, absorption, and birefringence of large-size bulk single-crystal sapphire

While the thermomechanical properties of sapphire make it an excellent candidate of test mass for advanced laser interferometers, its optical quality is not well understood or well controlled. We have studied the results from high-resolution measurements of scattering, absorption, and birefringence in test-mass samples to better understand issues of quality. Samples show large-scale scattering structures clearly linked to the crystal-growth process. Samples characterized by the presence of point defects have significantly lower scattering (except at the point defects). In general on a large scale, high scattering also correlates with higher absorption and higher average birefringence inhomogeneity. However, on a smaller scale there is not a clear point-to-point correlation between scattering and absorption. Often a large-scale scattering structure is spatially displaced by tens of millimeters from a similar absorption structure, indicating that quite separate microscopic mechanisms give rise to scattering and absorption. The spatial displacements indicate that absorption centers and scattering centers are laid down during crystal growth at different distances from the solid-liquid interface. We suggest that absorption may be linked to F centers, while scattering may be linked to impurities such as iron.     

An investigation of factors reducing seat belt use amongst Spanish drivers and passengers on urban roads

Seat belt use on Spain's highways is more than 80%, while on the urban roads this figure is around 50%. As there was little information available to explain the difference in seat belt use rates, the main aim of this study was to investigate why there is a lower rate of seat belt use on urban roads. A number of perceptions, beliefs and expectancies about seat belt use were examined to identify variables that discriminated between seat belt users and non-users on urban roads. The subjects were 398 undergraduate students (aged 17-47) studying at the University of Girona, Spain. On the urban roads reported discomfort from using the seat belt was higher, while perceptions of risk (for non-users), safety perceptions (for those using a seat belt), beliefs about the seriousness of a crash or the effectiveness of the seat belt were all lower than on the highway. Perceptions of safety, discomfort, and social influence predicted seat belt use on urban roads. Concern about being fined for not using a seat belt did not predict seat belt use. The results of this research suggest that in order to increase seat belt use on urban roads, the issue of discomfort must be addressed. In addition, prevention campaigns should include information about the effectiveness of the seat belt in preventing/reducing injuries or deaths on urban roads. The results also highlight the importance of social influence for determining seat belt use/non-use and the potential role social influence could play in increasing seat belt usage.     

A testing device for rolling–sliding behavior in harsh environments: the twin-disk cryotribometer

Understanding the mechanical behavior of angular contact ball bearing contacts in extremely harsh environments has led to the development of specialized apparatus. This device simulates the rolling–sliding behavior of elliptical contacts where the dynamic and kinematic conditions are perfectly controlled. Such a device facilitates several types of analyses: that of mechanically induced surface damage, that of transfer film, that of characterizing surface treatments and surface coatings, and that of thermal phenomena at the contact. Moreover the testing device allows the experimental confirmation of theoretical models developed for determining bearing lifetimes. First we shall describe the testing device end afterwards we shall present results for each type of analysis mentioned above.