The pathophysiology and clinical relevance of platelet heterogeneity

Recent studies on platelet heterogeneity support the hypothesis that platelet production is regulated to maintain a constant functional platelet mass. In concept this form of regulation is analogous to the manner by which RBC production is controlled to maintain the oxygen- carrying capacity of blood. The platelet mass appears to correlate more closely with platelet function than the platelet count alone, since several factors in addition to the platelet count have been shown to influence the platelets' hemostatic function. These factors include platelet size, density, age, and previous hemostatic interactions. Application of these concepts to clinical problems has provided important insights into platelet physiology and reactivity. Failure to account for differences in platelet heterogeneity among individuals may introduce significant errors in the interpretation of data from laboratory and clinical investigations. However, despite advances, a number of practical issues remain to be resolved before measurements of platelet heterogeneity become accepted as routine clinical tests and are used in the diagnosis of pathologic states.     

Concerns about anti-angiogenic treatment in patients with glioblastoma multiforme

Background  

The relevance of angiogenesis inhibition in the treatment of glioblastoma multiforme (GBM) should be considered in the unique context of malignant brain tumours. Although patients benefit greatly from reduced cerebral oedema and intracranial pressure, this important clinical improvement on its own may not be considered as an anti-tumour effect.     

Why screen for cystic fibrosis? A clinician's view

Cystic fibrosis (CF) is relatively common, serious, and causes progressive lung damage. Clinical diagnosis may be delayed until lung damage has occurred, and infection may start as early as six weeks of life. A well organised screening programme should identify the great majority of affected infants within the first three weeks after birth, which leaves a small time window during which effective preventive treatment and surveillance may be instituted. Active treatment, whether for screened or unscreened infants, improves clinical status and long-term survival of CF patients. It is anticipated that new treatments will become available within the next few years, and these will clearly give maximal benefit to young infants if instituted before lung damage is evident. In addition to any hypothetical effects on morbidity and survival, pre-symptomatic diagnosis greatly improves the doctor-parent relationship. Economic arguments may be distorted, but, at best, screening is cost-beneficial, and, at worst, it is cost-neutral. The overwhelming majority of CF professionals and parents universally support neonatal screening, so the onus is therefore on those who oppose screening to prove that their approach offers a superior strategy.     

DEEP VEIN THROMBOSIS AS A PRESENTING SYMPTOM OF CONGENITAL INTERRUPTION OF THE INFERIOR VENA CAVA

Intrahepatic interruption of the inferior vena cava is a congenital anomaly, resulting in venous drainage of the lower extremities by way of a compensatory enlarged vena azygos system. We report the case of a 37-year-old male who presented with symptoms of deep vein thrombosis of the entire right lower extremity. A right-sided mediastinal mass on the chest X-ray was mistaken for a haematological malignancy but proved later to represent an enlarged azygos vein. The case illustrates that in a case of deep vein thrombosis, especially in younger patients, interruption of the inferior vena cava should be considered. A right-sided paratracheal mass on the chest X-ray may give a clue in making the correct diagnosis.     

Percutaneous renal biopsy complicated by renal capsular artery pseudoaneurysm

We report a case of renal capsular artery pseudoaneurysm caused by percutaneous renal biopsy. The injury was diagnosed and treated with arteriography and transarterial embolization. Because the arterial injury was extraparenchymal, the clinical manifestations of blood loss were flank pain and decreasing hematocrit without hematuria. Injury to renal capsular arteries during percutaneous renal biopsy is a rare possibility because of their small size.     

108例创伤性动静脉瘘的介入诊疗分析

目的分析创伤性动静脉瘘（AVF）的临床特点、造影表现、造影技术及治疗方式的选择。方法回顾性分析纽约Kings County医疗中心25年间全部确诊的108例创伤性AVF的介入相关诊疗资料。分析内容包括患者外伤种类、临床表现、损伤部位、血管造影异常特征、AVF血流动力学特征（分5个类型）、治疗方式的选择等。结果 108例患者中共发现117处AVF,大多数患者临床特征不明确。创伤种类包括枪伤（导致72处AVF）、刺伤（24处）、钝性伤（8处）、高处坠落伤（3处）、医源性损伤（2处）。损伤部位常见于肢体（46例）、颈部（19例）、肝脏（13例）和锁骨下血管（11例）。所有病变均可见静脉早显,显示动脉横断52处,撕裂37处,49.6%的AVF与假性动脉瘤有关。最常见的血流特点是Ⅰ型,即瘘口所在的动脉近段和远段、静脉的近段和远段都显示,伴远侧段静脉瓣功能不全,共40处瘘（34.2%）,其次是Ⅲ型22个（18.8%）,Ⅴ型最不常见（4.3%）。34例接受手术治疗,61例栓塞治疗,7例临床观察。分别采用弹簧圈（47例）、明胶海绵（9例）、无水乙醇（3例）、可脱球囊（2例）,其中弹簧圈效果理想、并发症少。6例采用覆膜支架效果好。结论血管造影是诊断创伤性AVF的金标准,造影时准确观察动脉损伤的性质,瘘口的解剖和血流特点及所有进入瘘口的动脉分支,对于选择治疗方式及保证介入治疗的成功完成至关重要。     

脊髓损伤后一氧化氮含量及一氧化氮合酶活性的变化与脊髓水肿的关系

目的 :为了探讨脊髓损伤后一氧化氮 (NO)含量及其合酶 (NOS)活性与脊髓水肿的关系。方法 :测定不同程度脊髓损伤后NO含量及NOS活性的变化 ,同时测定脊髓组织含水量。结果 :随着损伤程度的增加 ,NO含量及NOS活性均增加 ,脊髓组织水肿增加。结论 :脊髓损伤后NO含量及NOS活性增加 ,与脊髓组织的水肿密切相关 ,提示NO参与了脊髓伤后的病理生理改变。