GALC transduction leads to morphological improvement of the twitcher oligodendrocytes in vivo

Globoid cell leukodystrophy (GLD, Krabbe disease) is a severe demyelinating disease caused by a genetic defect of beta-galactocerebrosidase (GALC). To date treatment to GLD is limited to hematopoietic stem cell transplantation. Experimental approaches by means of gene therapy in twitcher mouse, an authentic murine model of human GLD, showed significant but only marginal improvements of the disease. To clarify whether the introduction of GALC could provide beneficial effects on the oligodendrocytes in GLD, we transduced twitcher oligodendrocytes by stereotactically injecting recombinant retrovirus encoding GALC-myc-tag fusion gene into the forebrain subventricular zone of neonatal twitcher mouse. In vivo effects of exogenous GALC on twitcher oligodendrocytes were studied histologically by combined immunostaining for the myc-epitope and the oligodendroglial specific marker, pi form of glutathione-S-transferase, at around 40 days of age. We show here that GALC transduction led to dramatic morphological improvement of the twitcher oligodendrocytes comparing with those in untreated twitcher controls. This study provided direct in vivo evidence that GALC transduction could prevent or correct aberrant morphology of oligodendrocytes in GLD which may be closely related to the dysfunction and/or degeneration of oligodendrocytes and the demyelination in this disease.     

Contribution of redox-active iron and copper to oxidative damage in Alzheimer disease

Metal-catalyzed hydroxyl radicals are potent mediators of cellular injury, affecting every category of macromolecule, and are central to the oxidative injury hypothesis of Alzheimer disease (AD) pathogenesis. Studies on redox-competent copper and iron indicate that redox activity in AD resides exclusively within the neuronal cytosol and that chelation with deferoxamine, DTPA, or, more recently, iodochlorhydroxyquin, removes this activity. We have also found that while proteins that accumulate in AD possess metal-binding sites, metal-associated cellular redox activity is primarily dependent on metals associated with nucleic acid, specifically cytoplasmic RNA. These findings indicate aberrations in iron homeostasis that, we suspect, arise primarily from heme, since heme oxygenase-1, an enzyme that catalyzes the conversion of heme to iron and biliverdin, is increased in AD, and mitochondria, since mitochondria turnover, mitochondrial DNA, and cytochrome C oxidative activity are all increased in AD. These findings, as well as studies demonstrating a reduction in microtubule density in AD neurons, suggest that mitochondrial dysfunction, acting in concert with cytoskeletal pathology, serves to increase redox-active heavy metals and initiates a cascade of abnormal events culminating in AD pathology.     

Glibenclamide treatment in a Cantú syndrome patient with a pathogenic ABCC9 gain‐of‐function variant: Initial experience

Cantú syndrome (CS), characterized by hypertrichosis, distinctive facial features, and complex cardiovascular abnormalities, is caused by pathogenic variants in ABCC9 and KCNJ8 genes. These genes encode gain‐of‐function mutations in the regulatory (SUR2) and pore‐forming (Kir6.1) subunits of K_ATP channels, respectively, suggesting that channel‐blocking sulfonylureas could be a viable therapy. Here we report a neonate with CS, carrying a heterozygous ABCC9 variant (c.3347G>A, p.Arg1116His), born prematurely at 32 weeks gestation. Initial echocardiogram revealed a large patent ductus arteriosus (PDA), and high pulmonary pressures with enlarged right ventricle. He initially received surfactant and continuous positive airway pressure ventilation and was invasively ventilated for 4 weeks, until PDA ligation. After surgery, he still had ongoing bilevel positive airway pressure (BiPAP) requirement, but was subsequently weaned to nocturnal BiPAP. He was treated for pulmonary hypertension with Sildenafil, but failed to make further clinical improvement. A therapeutic glibenclamide trial was commenced in week 11 (initial dose of 0.05 mg^–1 kg^–1 day^–1 in two divided doses). After 1 week of treatment, he began to tolerate time off BiPAP when awake, and edema improved. Glibenclamide was well tolerated, and the dose was slowly increased to 0.15 mg^?1 kg^?1day^?1 over the next 12 weeks. Mild transient hypoglycemia was observed, but there was no cardiovascular dysfunction. Confirmation of therapeutic benefit will require studies of more CS patients but, based on this limited experience, consideration should be given to glibenclamide as CS therapy, although problems associated with prematurity, and complications of hypoglycemia, might limit outcome in critically ill neonates with CS.     

人FascDNA的克隆及其在大肠杆菌中表达的研究

为获得高质量及充足的Ｆａｓ蛋白，采用ＰＣＲ技术调整Ｆａｓ基因的开放阅读框架，使之与生物素化蛋白基因阅读框架一致；缺失了ＦａｓｃＤＮＡ基因的起始密码子并增加一个大肠杆菌偏性终止密码子，构建ＦａｓｃＤＮＡ和生物素化融合原核表达质粒ＰｉｎＰｏｉｎｔ－Ｆａｓ。将重组质粒转入大肠杆菌ＨＢ１０１，经５００ｍｍｏｌＩＰＴＧ在３７℃条件下诱导４ｈ，ＳＤＳ－ＰＡＧＥ及Ｗｅｓｔｅｒｎ印迹检测融合蛋白在大肠杆菌得以高效表达，表达量为细菌总蛋白的１３．８％。用亲和层析树脂对生物素化融合蛋白进行亲和层析纯化，得到Ｆａｓ重组的蛋白，且表达的Ｆａｓ融合蛋白具有抗体结合活性。此蛋白的表达成功将解决Ｆａｓ膜蛋白不易提取的难题，为深入研究Ｆａｓ提供了良好材料来源     

Emergency department visits for asthma: the role of frequent symptoms and delay in care.

BACKGROUND: Use of the emergency department (ED) for asthma care is a costly form of health care that is largely preventable. However, little is known about how to reduce the number of people using the ED for asthma care. OBJECTIVE: To identify modifiable factors related to ED visits for asthma among a diverse nonelderly adult population. METHODS: This study used cross-sectional data from the 2001 California Health Interview Survey. A total of 4,359 adult respondents ages 18 to 64 years who reported being diagnosed as having asthma and experiencing symptoms in the past year were included. Any ED visits due to asthma in the previous 12 months among all nonelderly respondents with asthma, with stratification by those with daily or weekly symptoms and with less frequent symptoms, were examined. RESULTS: Adults with daily or weekly asthma symptoms, with fair or poor health status, and who delayed care for asthma because of cost or insurance issues were more likely to visit the ED for asthma. Stratification of the study population into those with daily or weekly symptoms and those with less frequent symptoms revealed that delay in care due to cost or insurance issues and fair or poor health status remained significant for both groups. Latinos and women were more likely to visit the ED in the severe asthma group, whereas Asian, African American, and uninsured adults were more likely to visit the ED in the group with less severe asthma. CONCLUSIONS: Results suggest that to prevent ED visits for asthma, it is important to control asthma symptoms. However, it is equally if not more important to reduce delays in receiving asthma care.     

维生素A阻抑大鼠实验性肝纤维化的病理研究

利用光镜、电镜、免疫组化和形态学定量技术动态研究维生素A对大鼠四氯化碳肝纤维化的抑制作用。结果表明,维生素A可减少四氯化碳中毒大鼠肝内纤维连接蛋白和Ⅰ、Ⅲ型胶原沉积,抑制贮脂细胞向成纤维细胞转化,并可明显地减轻肝纤维化程度。本文还对维生素A抑制肝纤维化的机理及意义作了初步探讨。     

Differential expression of stem cell mobilization-associated molecules on multi-lineage cells from adipose tissue and bone marrow

Our laboratory has characterized a population of stromal cells obtained from adipose tissue termed processed lipoaspirate cells (PLAs). PLAs, like bone-marrow derived mesenchymal stem cells (BM-MSCs), have the capacity to differentiate along the adipogenic, osteogenic, chondrogenic, and myogenic lineages, In order to better characterize these two multi-lineage populations, we examined the surface phenotype of both bone marrow and adipose tissue-derived cells from five patients undergoing surgery. PLA and BM-MSC cells were isolated, subcultivated, and evaluated for cell surface marker expression using flow cytometry. PLA and BM-MSC cells both expressed CD13, CD29, CD44, CD90, CD105, SH-3, and STRO-1. Differences in expression were noted for cell adhesion molecules CD49d (Integrin alpha4), CD54 (ICAM-1), CD34, and CD106 (VCAM-1). While markedly similar, the surface phenotypes of PLA and BM-MSC cells are distinct for several cell adhesion molecules implicated in hematopoietic stem cell homing, mobilization, and proliferation.     

“Smart” Materials for Biosensing Devices: Cell-Mimicking Supramolecular Assemblies and Colorimetric Detection of Pathogenic Agents

Mimicking cell membrane and the biomolecular recognition associated with membranes represents a great technical challenge, yet it has opened doors to innovative diagnostic and therapeutic methods. Our work has focused on design and synthesis of a class of smart materials exploiting biological principals for use in biosensors: these materials are functional polymeric assemblies that mimic the cell membrane and conveniently report the presence of pathogens with a color change. Biologically active cell membrane components are incorporated into conjugated polymers with desirable optical properties and the binding of the target molecules onto the material triggers conformational and electronic shifts that are reflected in a chromatic change (a so-called biochromic shift) that is conveniently observed and recorded. Langmuir–Blodgett thin films and vesicle bilayers provide ideal configurations for precise delivery of the biological binding entity to the sensing interface, and for control of molecular orientation for effective biomolecular interaction. Polydiacetylenic membrane-mimicking materials containing cell surface receptor gangliosides and sialic acid residues, respectively were formulated into these architectures and used for colorimetric detection of bacterial toxins and influenza virus. One advantage of these biochromic conjugated polymer (BCP) sensors is that their molecular recognition and signal transduction functionalities are resident in a single functional unit, making them amenable to convenient microfabrication and use.