Ex vivo rapamycin treatment of human cord blood CD34+ cells enhances their engraftment of NSG mice

Since cord blood (CB) has become a commonly used source of transplantable hematopoietic stem (HSC) and hematopoietic progenitor cells (HPC), there has been a need to overcome the limited HSC and HPC numbers available to transplant from a single CB, especially for adult recipients. Our laboratory previously demonstrated that Rheb2 overexpression significantly impaired the repopulating ability of HSC. Since overexpression of Rheb2 leads to increased signaling through mTOR, we examined the effect of the mTOR inhibitor rapamycin ex vivo on cytokine expanded CD34(+) CB cells for the engraftment of these cells in non-obese diabetic, severe combined immunodeficient, IL-2 receptor γ chain null (NSG) mice. We observed significant enhancement in engraftment of the CB treated ex vivo with cytokines in the presence of rapamycin prior to transplant, effects seen in primary as well as secondary transplants. These pre-clinical results suggest a positive role for rapamycin during ex vivo culture of CB SCID repopulating cells/HSC.     

Identification of a cellulose synthase-associated protein required for cellulose biosynthesis

Cellulose synthase-interactive protein 1 (CSI1) was identified in a two-hybrid screen for proteins that interact with cellulose synthase (CESA) isoforms involved in primary plant cell wall synthesis. CSI1 encodes a 2,150-amino acid protein that contains 10 predicted Armadillo repeats and a C2 domain. Mutations in CSI1 cause defective cell elongation in hypocotyls and roots and reduce cellulose content. CSI1 is associated with CESA complexes, and csi1 mutants affect the distribution and movement of CESA complexes in the plasma membrane.     

Resveratrol and liver disease: from bench to bedside and community

Liver diseases incorporate several maladies, which can range from benign histological changes to serious life‐threatening conditions. These may include inborn metabolic disease, primary and metastatic cancers, alcoholic cirrhosis, viral hepatitis and drug‐induced hepatotoxicity. Liver disease remains a major cause of morbidity and mortality with significant economic and social costs. Several novel approaches are currently being studied which may provide a better therapeutic outcome. The use of naturally occurring phytochemicals, some of them obtained from dietary sources, in the amelioration of illness have recently gained considerable popularity. These agents, having anti‐oxidant and anti‐inflammatory properties, provide a safe and effective means of ameliorating chronic disease. Resveratrol, a grape polyphenol, has shown considerable promise as a therapeutic agent in the treatment of the aforementioned liver ailments. Several studies have highlighted the hepatoprotective properties of resveratrol. Resveratrol has been shown to prevent hepatic damage because of free radicals and inflammatory cytokines, induce anti‐oxidant enzymes and elevate glutathione content. Resveratrol has also been shown to modulate varied signal transduction pathways implicated in liver diseases. This review critically examines the current preclinical in vitro and in vivo studies on the preventive and therapeutic effects of resveratrol in liver diseases. The review highlights the pharmacological mechanisms involved in mediating the aforementioned effects. Toxicity, pharmacokinetics and clinical bioavailability of resveratrol are also reviewed in this article. The challenges involved, future directions and novel approaches such as site‐specific drug delivery in the use of resveratrol for the prevention and treatment of liver disease are also discussed.     

口腔白斑病组织中环状RNA的差异表达谱分析

目的 探讨环状RNA(circRNA)在口腔白斑(oral leukoplakia,OLK)组织及正常口腔黏膜组织(nor-mal oral mucosal,NOM)中表达谱的差异及临床意义.方法 采用高通量测序技术检测6对OLK和NOM组织中差异表达circRNA,利用qRT-PCR验证所筛选的10个circRNA在...     

人源抗狂犬病毒G蛋白单链抗体的生物学鉴定及其小鼠体内中和活性测定

目的对从噬菌体抗体库中筛选的人源抗狂犬病毒单链抗体A12进行生物学活性鉴定及小鼠体内中和活性检测。方法用免疫荧光法检测其结合感染狂犬病毒CVS的鼠脑组织的能力,用小鼠中和实验测定A12表达产物的体内中和活性。结果免疫荧光试验显示A12表达产物与感染CVS的鼠脑细胞有强的荧光反应。小鼠中和试验结果表明,A12ScFv样品组小鼠有9只存活,而对照组小鼠全部死亡。A12在729倍稀释时能100%保护小鼠抵抗致死量狂犬病毒的脑内攻击。结论A12对狂犬病毒具有一定的中和活性,有可能被用于暴露后狂犬病的预防。     

Radiofrequency ablation during continuous saline infusion can extend ablation margins

AIM:To determine whether fluid injection during radiofrequency ablation(RFA) can increase the coagulation area.METHODS:Bovine liver(1-2 kg) was placed on an aluminum tray with a return electrode affixed to the base,and the liver was punctured by an expandable electrode.During RFA,5% glucose;50% glucose;or saline fluid was infused continuously at a rate of 1.0 mL/min through the infusion line connected to the infusion port.The area and volume of the thermocoagulated region of bovine liver were determined after RFA.The Joule heat generated was determined from the temporal change in output during the RFA experiment.RESULTS:No liquid infusion was 17.3 ± 1.6 mL,similar to the volume of a 3-cm diameter sphere(14.1 mL).Mean thermocoagulated volume was significantly larger with continuous infusion of saline(29.3 ± 3.3 mL) than with 5% glucose(21.4 ± 2.2 mL),50%glucose(16.5 ± 0.9 mL) or no liquid infusion(17.3 ± 1.6 mL).The ablated volume for RFA with saline was approximately 1.7-times greater than for RFA with no liquid infusion,representing a significant difference between these two conditions.Total Joule heat generated during RFA was highest with saline,and lowest with 50% glucose.CONCLUSION:RFA with continuous saline infusion achieves a large ablation zone,and may help inhibit local recurrence by obtaining sufficient ablation margins.RFA during continuous saline infusion can extend ablation margins,and may be prevent local recurrence.     

Characteristics of Hypertensive Patients With Increased Plasma Na+-K+Pump Inhibitory Activity

Recent studies in our laboratories and in the laboratories of other investigators suggest the presence of a sodium-potassium pump inhibitor in the plasma of some patients with arterial hypertension. We here review these studies in an attempt to determine what characteristics increase the likelihood of detecting the inhibitor. The review suggests but does not prove that the inhibitor is most likely to be found in males with increased sodium intake, decreased renal function, and decreased plasma renin activity. In future studies of plasma sodium-potassium pump inhibitory activity in hypertensive humans, we should pay more attention to the characteristics of the patients. These characteristics include age, sex, race, therapy, stage of hypertension, sodium intake, renal function, and renin status. We should also make an attempt to match the patients properly with normotensive control subjects.     

Engineering a lysosomal enzyme with a derivative of receptor-binding domain of apoE enables delivery across the blood–brain barrier

To realize the potential of large molecular weight substances to treat neurological disorders, novel approaches are required to surmount the blood–brain barrier (BBB). We investigated whether fusion of a receptor-binding peptide from apolipoprotein E (apoE) with a potentially therapeutic protein can bind to LDL receptors on the BBB and be transcytosed into the CNS. A lysosomal enzyme, α-L-iduronidase (IDUA), was used for biological and therapeutic evaluation in a mouse model of mucopolysaccharidosis (MPS) type I, one of the most common lysosomal storage disorders with CNS deficits. We identified two fusion candidates, IDUAe1 and IDUAe2, by in vitro screening, that exhibited desirable receptor-mediated binding, endocytosis, and transendothelial transport as well as appropriate lysosomal enzyme trafficking and biological function. Robust peripheral IDUAe1 or IDUAe2 generated by transient hepatic expression led to elevated enzyme levels in capillary-depleted, enzyme-deficient brain tissues and protein delivery into nonendothelium perivascular cells, neurons, and astrocytes within 2 d of treatment. Moreover, 5 mo after long-term delivery of moderate levels of IDUAe1 derived from maturing red blood cells, 2% to 3% of normal brain IDUA activities were obtained in MPS I mice, and IDUAe1 protein was detected in neurons and astrocytes throughout the brain. The therapeutic potential was demonstrated by normalization of brain glycosaminoglycan and β-hexosaminidase in MPS I mice 5 mo after moderate yet sustained delivery of IDUAe1. These findings provide a noninvasive and BBB-targeted procedure for the delivery of large-molecule therapeutic agents to treat neurological lysosomal storage disorders and potentially other diseases that involve the brain.     

Low-density platelet populations demonstrate low in vivo activity in sporadic Alzheimer disease

Platelets contain a substantial quantity of amyloid-precursor protein (APP) and β-amyloid. However, despite the large importance of APP and β-amyloid to dementia, little is known about platelets in sporadic Alzheimer dementia (AD). Furthermore, platelet heterogeneity influences human pathology and has been described to affect the progression of AD. This study investigated AD platelets with respect to density diversity and in vivo activity associated with density sub-fractions. We included 39 AD patients and used, as controls, 22 elderly individuals without apparent memory disorder. A continuous Percoll? gradient covering the density span 1.04–1.09?kg/l provided the basis to divide platelets of whole blood into density fractions (n?=?16). All platelet populations were evaluated accordingly. Platelet counts were determined electronically. A flow-cytometer was put to use to measure surface-bound fibrinogen as a measure of platelet in vivo activity. Samples obtained from patients diagnosed with sporadic AD contained platelets (fractions numbers 4–16) that circulated with significantly less surface-bound fibrinogen, i.e., their platelet activation in vivo was reduced, compared with controls. In particular, highly significant differences (p?<?0.001) were obtained for the six less dense platelet populations (fractions numbers 11–16) when comparing sporadic AD with controls. In contrast, the densest AD platelets in fractions numbers 1–3 did not differ significantly from control cells with respect to in vivo platelet-bound fibrinogen. It is concluded that sporadic AD is characterized by lower density platelet populations that, while circulating, exhibited reduced activation. The clinical significance of this finding is unclear but these results suggest the importance of platelet heterogeneity in dementia as a topic for further investigation.     

脐血造血干/祖细胞体外定向诱导扩增的研究

目的　观察不同因子组合在体外对脐血 (CB)中的巨核系等造血祖细胞的诱导扩增作用。方法　用体外液体悬浮培养法 ,将白细胞介素 3(IL 3)、白细胞介素 6 (IL 6 )、血小板生成素 (TPO)、脐血血浆 (CBP)作为刺激因子 ,添加不同的细胞因子组合 ,对CB的单个核细胞 (MNC)短期培养 2 1d。在培养的 0、7、14、2 1d检测新鲜细胞和培养细胞中的有核细胞数 (NC)、巨核系祖细胞 (CFU Mk)、粒巨噬系祖细胞 (CFU GM)、混合系祖细胞 (CFU GEMM)增殖倍数。结果　在 2 1d内 ,3个实验组的NC数 ,CFU GM、CFU Mk、CFU GEMM都有不同程度的增加 ,其中NC、CFU GM在培养的 2 1d达到高峰。CFU Mk、CFU GEMM在培养的 14d达高峰。在含有TPO的实验组中 ,CFU Mk的增殖倍数高于不含TPO的实验组 ,CFU GM、CFU GEMM增殖的倍数也高于不含TPO的实验组。含有CBP的实验组对CFU GM、CFU Mk、CFU GEMM有明显的促增殖作用。结论　CB中的含有丰富的造血干 祖细胞 ,可以在不同细胞因子的刺激下进行定向扩增 ,TPO可以促进干 祖细胞向巨核系分化 ,对粒巨噬系祖细胞也有促进作用。脐血血浆可以作为协同刺激因子促进CB中干 祖细胞增殖。