Monocytes/macrophages infected with Toxoplasma gondii do not increase co‐stimulatory molecules while maintaining their migratory ability

Toxoplasma gondii is an obligate intracellular parasite that is able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. The parasite is able to infect macrophages and dendritic cells and use them for dispersal throughout the body, but the activation state of those cells is unknown. We investigated the ability of human and murine cells from monocytic/macrophage lineages that had not previously been exposed to inflammatory cytokines to up‐regulate co‐stimulatory and adhesion molecules upon infection. Toxoplasma gondii‐infected human monocytes (freshly isolated and THP1 lineage) were unable to up‐regulate CD86, CD83, CD40 or CD1a. CD80 expression increased in infected cells but expression of l ‐selectin and β2 integrin was unaltered. We evaluated the ability of infected macrophages from wild type C57/BL/6 or CD14^?/? mice to migrate in 8 μm transwells. Infected cells from CD14^?/? mice were more likely to de‐adhere than infected cells from wild type mice but they did not show any increase in migratory ability. The non‐stimulatory profile of these infected cells may contribute to parasite spread throughout the lymphatic circulation in the initial phases of infection.     

Mediastinal extramedullary erythropoiesis in hereditary spherocy tosis

Summary Evidence of thoracic extramedullary erythropoiesis has been noted before but it is considered rare in the course of chronic haemolytic anaemia. We report an adult who was admitted for splenectomy because of hereditary spherocytosis (HS). The evidence of a large mediastinal mass before surgery ledus, after isotopic scanning using ¹¹¹ Indium transferrin, to suspect extramedullary erythropoiesis; this was confirmed by cytology during surgery. The utility of ¹¹¹ Indium transferrin as a bone marrow tracer is also noted.     

Sleep deprivation suppresses the increase of rapid eye movement density across sleep cycles

We investigated the association between rapid eye movement (REM) density (REMd) and electroencephalogram (EEG) activity during non‐rapid eye movement (NREM) and REM sleep, within the re‐assessment, in a large sample of normal subjects, of the reduction of oculomotor activity in REM sleep after total sleep deprivation (SD). Coherently with the hypothesis of a role of homeostatic sleep pressure in influencing REMd, a negative correlation between changes in REMd and slow‐wave activity (SWA) was expected. A further aim of the study was to evaluate if the decreased REMd after SD affects ultradian changes across sleep periods. Fifty normal subjects (29 male and 21 female; mean age = 24.3 ± 2.2 years) were studied for four consecutive days and nights. Sleep recordings were scheduled in the first (adaptation), second (baseline) and fourth night (recovery). After awakening from baseline sleep, a protocol of 40 h SD started at 10:00 hours. Polysomnographic measures, REMd and quantitative EEG activity during NREM and REM sleep of baseline and recovery nights were compared. We found a clear reduction of REMd in the recovery after SD, due to the lack of REMd changes across cycles. Oculomotor changes positively correlated with a decreased power in a specific range of fast sigma activity (14.75–15.25 Hz) in NREM, but not with SWA. REMd changes were also related to EEG power in the 12.75–13.00 Hz range in REM sleep. The present results confirm the oculomotor depression after SD, clarifying that it is explained by the lack of changes in REMd across sleep cycles. The depression of REMd can not simply be related to homeostatic mechanisms, as REMd changes were associated with EEG power changes in a specific range of spindle frequency activity, but not with SWA.     

CASE REPORT: Cytomegalovirus infection as a cause of acute portal vein thrombosis

We report on the case of a 31-year-old woman who developed acute portal vein thrombosis during the course of an acute cytomegalovirus (CMV) infection. We suggest a relationship between CMV infection, its endothelial cell-damaging effects and portal vein thrombosis.     

Venous blood platelets decrease during allergen-induced asthmatic reactions

To determine whether circulating platelets alter during asthmatic reactions induced by allergens, we studied nine subjects previously shown to develop an early or dual asthmatic reaction after inhalation challenge with extracts of house dust mite or grass pollen. In each subject, FEV1, circulating platelets and leucocytes were measured before, 15, 30 and 60 min, and 2, 4, 6 and 8 hr after inhalation of allergen and diluent control administered in a single-blind, randomized fashion. The same procedure was repeated in six of the nine subjects after bronchoconstriction induced by methacholine. Each subject developed an early asthmatic reaction after allergen inhalation challenge, which was followed by a late asthmatic reaction in six subjects and by an equivocal late asthmatic reaction in two of them (fall in FEV1 of 15 and 17% respectively). Compared with the control day, circulating platelets significantly decreased during the allergen-induced early asthmatic reaction (P less than 0.025, at 30 min). Platelet counts returned to baseline values within 4 hr and remained steady thereafter both in subjects who did and did not develop a late asthmatic reaction. No changes in platelet counts occurred after bronchoconstriction induced by methacholine. Diurnal increase of leucocyte numbers occurred after challenge with both allergen and diluent control. These results suggest that platelets may be involved in the pathogenesis of allergen-induced asthmatic reactions.