Thromboses et thrombopathies dans les syndromes myéloprolifératifs

Myeloproliferative neoplasms are acquired hematological malignancies, mainly affecting the adult and whose morbidity and mortality stems from haemostasis disorders. The most frequently encountered complications include thrombosis, affecting preferentially the arterial territory, but also atypical locations such as splanchnic vein thrombosis. The pathophysiology of these thromboses is complex and involves different actors: blood cells, endothelium and flow conditions. Numerous studies have been conducted to identify risk factors for thrombosis. To date, only two risk factors have been validated through prospective studies (age over 60 years old, history of thrombotic events) and allow classification of patients as “low risk” and “high risk” as the basis for current treatment recommendations. Haemorrhagic manifestations, less frequent than thrombosis, are mainly related to an alteration of primary haemostasis and are therefore manifested by mucocutaneous bleeding. In these patients, platelet dysfunctions and/or acquired Willebrand syndromes can be found. The pathophysiology of thrombosis and platelet dysfunction during myeloproliferative neoplasms remains to date partially unknown. In this review, we offer to focus on physiopathological mechanisms as well as the latest advances in their understanding.     

Transfusion outcome for volume- and plasma-reduced platelet concentrates for pediatric patients

Background and ObjectivesPlasma reduction in platelet concentrate (PC) products has been reported to prevent large volume load and transfusion-related adverse reactions (TRARs). However, volume reduction might be associated with a poor transfusion response because of a deterioration in platelet (PLT) quality. Because PLT quality control and transfusion responses for recently washed PCs using PLT additive solutions are superior, we investigated the clinical safety and transfusion efficacy of volume-reduced washed PCs in pediatric patients.Materials and MethodsWe prepared a simplified resuspended PC product (RPC) as a washed PC. Regular RPC (R-RPC) included equivalent volumes of bicarbonate Ringer's solution and anticoagulant citrate dextrose solution A (BRS-A) as the resuspension solution. Half RPC (H-RPC) was prepared by adding a half volume of BRS-A. Twenty-four pediatric patients were scheduled for transfusions with R-RPC and H-RPC up to 4 times. R-RPC was transfused 42 times into 24 patients. H-RPC was transfused 41 times into 23 patients.ResultsNeither product was observed to cause TRARs. Although the calculated PLT recovery for H-RPC was significantly reduced, the posttransfusion corrected count increment (24 h) did not differ. Moreover, similar results were observed for vital signs during transfusion.ConclusionVolume-reduced washed PC can be transfused without causing TRARs, differences in vital signs, or inferior transfusion responses. Volume-reduced washed PC also provides the advantages of shortened transfusion times and reduced volume loads. Although a standard technique for stable resuspension is necessary, volume-reduced washed PC may be a beneficial option for children, including neonates, or individuals with cardiovascular or renal problems.     

腺样体肥大或伴扁桃体肥大的睡眠呼吸障碍儿童平均血小板体积和血小板分布宽度变化的临床意义

目的 探讨腺样体肥大或伴扁桃体肥大的睡眠呼吸障碍(SDB)儿童的平均血小板体积(MPV)和血小板分布宽度(PDW)变化的临床意义。方法 选择2018年1月至2019年1月安徽医科大学附属巢湖医院耳鼻咽喉-头颈外科住院患儿99例,均诊断为SDB(腺样体肥大或伴扁桃体肥大),设为病例组。另选取同时期因SDB以外原因(包括先天性耳前瘘管,鼻骨骨折,先天性鳃裂瘘管,颈部良性肿瘤,外耳道异物)而收住入院的51例患儿为对照组,并经过仔细询问病史,否认有SDB,体格检查均无腺样体肥大或伴有扁桃体肥大。记录病例组与对照组的血常规各项指标数值,比较两组血常规相关指标的差异。结果 病例组平均血小板体积(MPV)为(10.89±1.30)fL,对照组为(11.38±1.28)fL,差异有统计学意义(P<0.05)。对照组血小板分布宽度(PDW)为[13.60(12.00,15.90)]fL,病例组为[12.70(10.85,15.35)]fL,差异有统计学意义(P<0.05)。其余血常规指标在病例组与对照组间差异均无统计学意义(P>0.05)。Pearson积差相关分析显示,病例组的MPV和PDW均与年龄呈正相关,Spearman秩相关显示,MPV和PDW均与腺样体肥大等级呈负相关。结论 MPV和PDW可能作为判断腺样体肥大或伴有扁桃体肥大SDB患儿病情严重程度的潜在指标。     

Structural adaption of axons during de‐ and remyelination in the Cuprizone mouse model

Multiple Sclerosis is an autoimmune disorder causing neurodegeneration mostly in young adults. Thereby, myelin is lost in the inflammatory lesions leaving unmyelinated axons at a high risk to degenerate. Oligodendrocyte precursor cells maintain their regenerative capacity into adulthood and are able to remyelinate axons if they are properly activated and differentiate. Neuronal activity influences the success of myelination indicating a close interplay between neurons and oligodendroglia. The myelination profile determines the distribution of voltage‐gated ion channels along the axon. Here, we analyze the distribution of the sodium channel subunit Nav1.6 and the ultrastructure of axons after cuprizone‐induced demyelination in transgenic mice expressing GFP in oligodendroglial cells. Using this mouse model, we found an increased number of GFP‐expressing oligodendroglial cells compared to untreated mice. Analyzing the axons, we found an increase in the number of nodes of Ranvier in mice that had received cuprizone. Furthermore, we found an enhanced portion of unmyelinated axons showing vesicles in the cytoplasm. These vesicles were labeled with VGlut1, indicating that they are involved in axonal signaling. Our results highlight the flexibility of axons towards changes in the glial compartment and depict the structural changes they undergo upon myelin removal. These findings might be considered if searching for new neuroprotective therapies that aim at blocking neuronal activity in order to avoid interfering with the process of remyelination.     

Postoperative development of sarcopenia is a strong predictor of a poor prognosis in patients with adenocarcinoma of the esophagogastric junction and upper gastric cancer

Background

There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).