Platelet interactions with viruses and parasites

Abstract

While the interactions between Gram-positive bacteria and platelets have been well characterized, there is a paucity of data on the interaction between other pathogens and platelets. However, thrombocytopenia is a common feature with many infections especially viral hemorrhagic fever. The little available data on these interactions indicate a similarity with bacteria-platelet interactions with receptors such as FcγRIIa and Toll-Like Receptors (TLR) playing key roles with many pathogens. This review summarizes the known interactions between platelets and pathogens such as viruses, fungi and parasites.     

妇科腹腔镜围手术期碳水化合物口服疗法对术后胰岛素抵抗影响的研究

目的观察妇科腹腔镜手术围术期碳水化合物口服疗法和传统禁饮食方案两种不同的临床处理措施对于术后胰岛素抵抗（IR）的影响。 方法选取2018年2月至8月入住徐州医科大学附属医院妇科，行腹腔镜下全子宫切除手术的非糖尿病患者共98例，将采用围术期碳水化合物口服疗法者作为观察组（50例），采用传统禁饮食方案者作为对照组（48例）。检测所有病例的术前、术后第1天及第3天的空腹血糖（FPG）及空腹胰岛素（FINS），并利用稳态模式评估法计算稳态模型胰岛素抵抗指数（HOME-IR）。对于观察组与对照组患者术前、术后第1天和术后第3天的FPG、FINS和HOME-IR等指标，组间比较采用独立样本t检验。两组患者术后腹胀、术后24 h通气、术后发热的发生情况的比较采用确切概率法检验。 结果观察组与对照组比较，术前和术后第1天FPG差异无统计学意义（P均>0.05），术后第3天FPG明显降低［（4.34±0.59）mmol/L vs （4.96±0.64）mmol/L］，差异有统计学意义（t=-4.96，P=0.002）。观察组与对照组比较，术前和术后第1天FINS差异无统计学意义（P均>0.05），术后第3天FINS明显降低［（45.39±13.55）mIU/L vs （51.18±9.34） mIU/L］，差异有统计学意义（t=-2.46，P=0.033）。观察组与对照组比较，术前HOME-IR差异无统计学意义（P>0.05），术后第1天和术后第3天HOME-IR明显降低［（13.08±4.80）vs （15.03±4.11）；（9.37±3.65）vs （11.30±2.55）］，差异有统计学意义（t=-0.69，P=0.042；t=-3.99，P=0.033）。两组患者术后其他观察指标比较，观察组术后24 h通气率与对照组比较明显增高（76.0% vs 64.6%），差异有统计学意义（P=0.045）。两组患者在术后腹胀、术后发热的发生率方面差异无统计学意义（P均>0.05）。两组患者均未发生术中误吸。 结论妇科腹腔镜手术围术期应用碳水化合物口服疗法较传统禁饮食方案，能有效减轻术后IR程度，促进术后康复进程，且不增加围术期并发症的发生率。     

Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep

Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.