运动时呼吸口罩对动脉血气变化的影响

本文实验说明,呼吸口罩对动脉PO_2、PCo_2、pH、HCo_3~-和血氧饱和度不起显著性影响,其条件是呼吸口罩不受呼吸气的涡流、密度、粘度、温度和湿度等因素影响,并且肺通气量在6～200升/分时。     

ECHOCARDlOGRAPHIC FINDINGS IN TOTAL ANOMALOUS PULMONARY VENOUS RETIJRN (TAPVR) TD THE CORONARY SINUS

Two patients with tolial anomalous pulmo- nary venous return (TAPVR) to the coronary sinus are described. Both patients were neo- nates, cyanotic and had heart murmiirs. In each ease the diagnosis was suggested on the echocardiogram, but a definitive diagnosis re- quired angiography. The echocardiogram of each patient demanstratcd an additional cham- ber posterior to the lcft atrium iu the region of the atrioventrieuIar groave wliich subse- quently proved to be an enlarged coronary siuus. At the time of catheterization, cardio- green dye was injected and the rcstilts ohserved on A-mode :in the cathet,crization laboratory. Recordings could not be obtained of the A- mode display.     

Postischemic hyperperfusion on arterial spin labeled perfusion MRI is linked to hemorrhagic transformation in stroke

The purpose of this study was to investigate the relationship between hyperperfusion and hemorrhagic transformation (HT) in acute ischemic stroke (AIS). Pseudo-continuous arterial spin labeling (ASL) with background suppressed 3D GRASE was performed during routine clinical magnetic resonance imaging (MRI) on AIS patients at various time points. Arterial spin labeling cerebral blood flow (CBF) maps were visually inspected for the presence of hyperperfusion. Hemorrhagic transformation was followed during hospitalization and was graded on gradient recalled echo (GRE) scans into hemorrhagic infarction (HI) and parenchymal hematoma (PH). A total of 361 ASL scans were collected from 221 consecutive patients with middle cerebral artery stroke from May 2010 to September 2013. Hyperperfusion was more frequently detected posttreatment (odds ratio (OR)=4.8, 95% confidence interval (CI) 2.5 to 8.9, P<0.001) and with high National Institutes of Health Stroke Scale (NIHSS) scores at admission (P<0.001). There was a significant association between having hyperperfusion at any time point and HT (OR=3.5, 95% CI 2.0 to 6.3, P<0.001). There was a positive relationship between the grade of HT and time–hyperperfusion with the Spearman''s rank correlation of 0.44 (P=0.003). Arterial spin labeling hyperperfusion may provide an imaging marker of HT, which may guide the management of AIS patients post tissue-type plasminogen activator (tPA) and/or endovascular treatments. Late hyperperfusion should be given more attention to prevent high-grade HT.     

Diabetes Mellitus,Acute Hyperglycemia,and Ischemic Stroke

Acute brain ischemia is a dynamic process susceptible to multiple modulating factors, such as blood glucose level. During acute ischemic brain injury, hyperglycemia exacerbates multiple deleterious derangements. Timely and sufficient correction of hyperglycemia during acute brain ischemia may limit the brain injury and improve clinical outcomes. The clinical efficacy of such intervention remains to be proven. Although results from animal and clinical observational studies suggest that hyperglycemia during acute brain ischemia may exacerbate the brain injury, there is no evidence from randomized treatment trials that rapid correction of the hyperglycemia improves outcomes. Given the excess effort, cost, and risk involved in rapid and safe correction of hyperglycemia during acute stroke, less aggressive treatments with subcutaneous insulin seem appropriate at this time. Subcutaneous insulin protocols can maintain blood glucose levels below 200 mg/dL a majority of the time in most patients, especially if basal insulin is added. When available, an endocrinology consultant can optimize the acute treatment and help the transition to long-term care. Given the multiple reports linking admission hyperglycemia with symptomatic hemorrhagic conversion of ischemic stroke treated with thrombolytic drugs, it may be best to rapidly lower severe hyperglycemia in such patients. For example, if the admission blood glucose is approximately 300 mg/dL and the patient is a candidate for thrombolytic therapy, consider giving an intravenous bolus of regular insulin 8 units. Somewhat lower or higher insulin doses may be best for lesser or greater hyperglycemia. Such a bolus will start lowering the blood glucose in about 5 min. A temporary continuous intravenous insulin infusion may then be used in most patients to maintain the glucose closer to normal levels (eg, below 180 or 140 mg/dL).     

Improved survival following bone marrow transplantation for aplastic anaemia

We transplanted 46 patients with severe aplastic anaemia with a new pretransplant immunosuppressive regimen consisting of cyclophosphamide (200 mg/kg) and low-dose total body irradiation (3 Gy). This regimen (CY-TBI-2) was designed to decrease the high risk of graft rejection associated with the use of cyclophosphamide alone, without increasing the incidence of graft-versus-host disease (GHVD) or interstitial pneumonia (IPn). Two-year actuarial disease-free survival of patients conditioned with CY-TBI-2 was 62% (95% CI: 47-77%). Only one patient rejected her graft and the incidence and severity of GVHD and IPn were not increased compared to previous studies. Patients less than 25 years of age had excellent 2-year survival of 82% (95% CI: 69-95%). These data indicate that CY-TBI-2 is an effective means of preventing graft-rejection and achieving long-term disease-free survival in multiply transfused patients with severe aplastic anaemia.     

Truncating mutations in APP cause a distinct neurological phenotype

Dominant missense mutations in the amyloid β (Aβ) precursor protein (APP) gene have been implicated in early onset Alzheimer disease. These mutations alter protein structure to favor the pathologic production of Aβ. We report that homozygous nonsense mutations in APP are associated with decreased somatic growth, microcephaly, hypotonia, developmental delay, thinning of the corpus callosum, and seizures. We compare the phenotype of this case to those reported in mouse models and demonstrate multiple similarities, strengthening the role of amyloid precursor protein in normal brain function and development. Ann Neurol 2016;80:456–460