The Role of Platelets in Infective Endocarditis

Over the last decade, the incidence of infective endocarditis (IE) has increased, with a change in the frequency of causative bacteria. Early evidence has substantially demonstrated the crucial role of bacterial interaction with human platelets, with no clear mechanistic characterization in the pathogenesis of IE. The pathogenesis of endocarditis is so complex and atypical that it is still unclear how and why certain bacterial species will induce the formation of vegetation. In this review, we will analyze the key role of platelets in the physiopathology of endocarditis and in the formation of vegetation, depending on the bacterial species. We provide a comprehensive outline of the involvement of platelets in the host immune response, investigate the latest developments in platelet therapy, and discuss prospective research avenues for solving the mechanistic enigma of bacteria-platelet interaction for preventive and curative medicine.

Combination of PI3K and MEK inhibitors yields durable remission in PDX models of PIK3CA-mutated metaplastic breast cancers

Background

Metaplastic breast cancer (MBC) is a rare form of breast cancer characterized by an aggressive clinical presentation, with a poor response to standard chemotherapy. MBCs are typically triple-negative breast cancers (TNBCs), frequently with alterations to genes of the PI3K-AKT-mTOR and RTK-MAPK signaling pathways. The objective of this study was to determine the response to PI3K and MAPK pathway inhibitors in patient-derived xenografts (PDXs) of MBCs with targetable alterations.

Methods

We compared survival between triple-negative MBCs and other histological subtypes, in a clinical cohort of 323 TNBC patients. PDX models were established from primary breast tumors classified as MBC. PI3K-AKT-mTOR and RTK-MAPK pathway alterations were detected by targeted next-generation sequencing (NGS) and analyses of copy number alterations. Activation of the PI3K-AKT-mTOR and RTK-MAPK signaling pathways was analyzed with reverse-phase protein arrays (RPPA). PDXs carrying an activating mutation of PIK3CA and genomic changes to the RTK-MAPK signaling pathways were treated with a combination consisting of a PI3K inhibitor and a MEK inhibitor.

Results

In our clinical cohort, the patients with MBC had a worse prognosis than those with other histological subtypes. We established nine metaplastic TNBC PDXs. Three had a pathogenic mutation of PIK3CA and additional alterations to genes associated with RTK-MAPK signaling. The MBC PDXs expressed typical EMT and stem cell genes and were of the mesenchymal or mesenchymal stem-like TNBC subtypes. On histological analysis, MBC PDXs presented squamous or chondroid differentiation. RPPA analysis showed activation of the PI3K-AKT-mTOR and RTK-MAPK signaling pathways. In vivo, the combination of PI3K and MAPK inhibitors displayed marked antitumor activity in PDXs carrying genomic alterations of PIK3CA, AKT1, BRAF, and FGFR4.

Conclusion

The treatment of metaplastic breast cancer PDXs by activation of the PI3K-AKT-mTOR and RTK-MAPK pathways at the genomic and protein levels with a combination of PI3K and MEK inhibitors resulted in tumor regression in mutated models and may therefore be of interest for therapeutic purposes.

« Réa’ssure moi » Des outils pour accompagner l’enfant visiteur en réanimation

Alors que se généralise progressivement l’ouverture des services de réanimation aux visites 24 heures sur 24, la présence des enfants semble encore controversée. Les unités de réanimation chirurgicale du CHU de Caen ont décidé de mettre fin à cette politique restrictive de visites. Cependant, accompagner un enfant face à la mort ou à la maladie ne s’improvise pas. La présence de ce « petit visiteur » est particulièrement stressante pour les familles et les soignants. Elle nécessite donc un encadrement spécifique, plus complexe que celui de l’adulte. En réponse à ce besoin, les équipes de réanimation du CHU de Caen ont développé divers supports (livret et pièce d’accueil, box de réanimation miniature) pour accompagner les enfants et soutenir les équipes soignantes dans cette démarche.

Fasciolosis due to Fasciola hepatica in ruminants in abattoirs and its economic impact in two regions in Algeria

and February 2009. The aim of the study was to determine the prevalence of infected livers with fascioliasis and to evaluate the economic loss due to the condemnation of livers infected with fascioliasis. A total of 3,457 cattle, 6,161 sheep and 5,764 goats were slaughtered and examined in El Tarf abattoir, north Algeria (humid climate), and 2,151 cattle, 5,724 sheep, 351 goats and 582 camels in Ouargla abattoir, south Algeria (saharan climate). In El Tarf region, the prevalence of fascioliasis infection was 26.7±2.5%, 6.5±0.4% and 2.5±0.2% in cattle, sheep and goats, respectively (P< 0.001). In Ouargla region, fascioliasis is reported for the first time in cattle (1.7±0.7%). Sheep, goats and camels were not infected. The overall economic loss due to hepatic condemnations as a result of fascioliasis was estimated at 60,000 euros in El Tarf region and 4,000 euros in Ouargla region. According to this study, it can be concluded that fascioliasis is endemic in the northern Algeria in ruminants and, the disease should be considered seriously as a great threat to ruminant health and profitability.

Sarcoidosis-related hypercalcemia in 3 chronic hemodialysis patients

Hypercalcemia is a frequent complication in chronic hemodialysis (CHD) patients. A rare cause of this condition is sarcoidosis, and has only been reported 6 times in CHD. Herein, we report on 3 cases of sarcoidosis-related hypercalcemia in CHD patients: an overt case, a probable case, and a recurrence of pre-dialysis sarcoidosis. Hypercalcemia is a frequent complication in chronic hemodialysis patients: it is often related to uncontrollable secondary hyperparathyroidism or to the inappropriate use of calcium phosphate binders, 1alpha-hydroxylated vitamin D metabolites, high dialysate calcium concentrations, or to aluminium-related bone disease [Uach and Bover 1996]. However, other rare causes should also be considered, such as multiple myeloma, non-Hodgkin lymphoma [Uach and Bover 1996], vitamin A intoxication [Fishbane et al. 1995], or granulomatous diseases such as sarcoidosis. The latter has only been described in a total of 6 hemodialysis patient reports [Barbour et al. 1981, Barnard et al. 2002, Herrero et al. 1998, Kalantar-Zadeh et al. 1994, Kuwae et al. 2003, Naito et al. 1999]. In the present paper, we report on 3 cases of sarcoidosis-related hypercalcemia in chronic hemodialysis patients with 3 different patterns, i.e. overt sarcoidosis, probable sarcoidosis, and recurrence of pre-dialysis sarcoidosis.