Improving Outcomes for Solid-Organ Transplant Recipients At Risk from Cytomegalovirus Infection: Late-Onset Disease and Indirect Consequences

Cytomegalovirus (CMV) is one of the most important pathogens following solid-organ transplantation, and effective prevention of CMV infection is a priority. The long-term control of CMV infection is dependent, in part, on the development of CMV-specific T cells, and controversy exists regarding whether CMV prophylaxis may prevent this. Although preemptive therapy is beneficial for the prevention of CMV disease, monitoring of viral levels in the blood does not always reflect what is occurring in tissues. Persistent low-level CMV infection has been associated with indirect consequences, such as transplant-associated vasculopathy, posttransplantation diabetes, an increased risk of opportunistic infection, and graft rejection. The issues surrounding preventive strategies for CMV disease following solid-organ transplantation are reviewed. We argue that prophylaxis is more effective than preemptive therapy; extending the duration of prophylaxis to the period of less intense immunosuppression could protect patients from late-onset disease, as well as from the indirect effects of CMV infectio

Conditions for the sliding-bouncing transition for the interaction of a bubble with an inclined wall

In this study we analyze the interaction of a single rising bubble with an inclined wall. We conduct experiments considering different liquids and bubble sizes, to cover a wide range of Reynolds and Weber numbers, with wall angles from nearly horizontal to nearly vertical. For all cases, the bubble initially collides with the wall; after the initial interaction, in accord with previous studies, the bubble either steadily slides on the wall or ascends, colliding repeatedly with it. Considering a force balance for the bubble motion on the wall, we propose a set of conditions for the transition from sliding to bouncing that is validated with the present and previous data

Sliding motion of a bubble against an inclined wall from moderate to high bubble Reynolds number

The motion of a bubble sliding over an inclined wall from moderate to high bubble Reynolds number is studied experimentally for a wide range of liquid properties and bubbles sizes, considering wall inclination angles from nearly horizontal to nearly vertical. All experiments are restricted to sliding behavior, below the transition to steady bouncing motion. We study both the shape of the bubble and its drag coefficient. For small angles, the bubble shape is dominated by gravitational effects resulting in a flattened shape against the wall; for large angles, the bubble remains in constant contact with the wall but adopts a shape that is aligned perpendicularly to the wall, closer to that observed for an inertia- dominated free rising bubble. We model this transition of shape considering balances among surface tension, gravitational, and inertial forces; we observe good agreement with experiments. We found that the drag coefficient is strongly influenced by the shape that the bubble adopts as it slides over the wall. By considering the flow in the film and around the bubble, we propose a correlation to predict the drag coefficient for each regime of bubble shape. In the regime dominated by viscous effects, the drag of a single bubble is increased due to the mirror effect with the wall and by the friction in the film formed between the wall; conversely, for the case dominated by inertial effects, the drag coefficient is constant. The behavior for a single bubble is changed: no significant increase due to deformation. In both shape regimes the proposed expression agrees well with the experimental measurements

Egg production in the euryhaline tilapia, Sarotherodon melanotheron heudelotii, experimentally maintained in fresh, sea and hypersaline waters

Through the experiments presented here we wanted to test whether egg production of the black-chinned tilapia Sarotherodon melanotheron heudelotii under experimental conditions varies as a function of ambient salinity (fresh waters vs. sea waters vs. hypersaline waters, 0, 35 and 70, respectively) and whether these responses differ between fish acclimated within a few weeks from fresh water to saline and hypersaline environments (experiments E1 and E2, monitoring over 10 and 18 weeks), and individuals born and raised all life long at the experimental salinities (E3, monitoring over 18 weeks). In total, 233 spawns were collected. In each of the three experiments, the reproductive investment (gram of egg per gram of female over 2 weeks) did not differ between salinities of 0 and 35, whereas it was 2-3 times lower at 70 than at 0-35, because of lower spawning frequency (E1-E3), smaller clutch size (E1) and lower spawn mass (E1-E3). Finally, fish acclimated to salinity from fresh water over a few weeks and those maintained at a particular salinity all life long showed similar reproductive traits, thereby emphasizing the remarkable physiological plasticity of this species

Mechanisms of opsonized HIV entry in normal B lymphocytes

AbstractUsing our in vitro model of normal B cell infection that functions with low doses of HIV but requires virus opsonization by seropositive patient serum, and complement, we analyzed what receptors allowed virus entry. Here, we show that HIV infection of B cells occurs through 2 major receptors: the CD4 antigen and the CR1/CR2 complex. These 2 pathways work independently since a complete inhibition of virus entry requires both CD4 and CD21/CD35 blockade on CD4dim tonsillar B cells whereas only the latter is critical on CD4-negative B cells

Plasticity of gene expression according to salinity in the testis of broodstock and F1 black-chinned tilapia, Sarotherodon melanotheron heudelotii

The black-chinned tilapia Sarotherodon melanotheron heudelotii Ruppell 1852 (Teleostei, Cichlidae) displays remarkable acclimation capacities. When exposed to drastic changes of salinity, which can be the case in its natural habitat, it develops quick physiological responses and keeps reproducing. The present study focused on the physiological impact of salinity on male reproductive capacities, using gene expression as a proxy of acclimation process. Two series of experimental fish were investigated: the first one was composed of fish maintained in freshwater for several generations and newly acclimated to salinities of 35 and 70, whereas the second one consisted of the descendants of the latter born and were raised under their native salinity. Expression patterns of 43 candidate genes previously identified from the testes of wild males was investigated in the three salinities and two generations. Twenty of them showed significant expression differences between salinities, and their predicted function revealed that most of them are involved in the osmotic tolerance of sperm cells and/or in the maintenance of sperm motility. A high level of expression variation was evidenced, especially for fish maintained in freshwater. In spite of this, gene expression patterns allowed the differentiation between fish raised in freshwater and those maintained in hypersaline water in both generations. Altogether, the results presented here suggest that this high variability of expression is likely to ensure the reproductive success of this species under varying salinities