门冬酰胺合成酶表达水平与儿童急性淋巴细胞白血病预后的相关性研究

目的 探讨儿童急性淋巴细胞白血病(ALL)肿瘤细胞中门冬酰胺合成酶(AS)基因表达水平是否与ALL的治疗反应和预后相关.方法 用实时荧光定量PCR(Real-time Quantitative PCR,RQ-PCR)测定53例初发ALL患儿骨髓单个核细胞(BMMNC)AS mRNA水平,结合其临床资料,统计分析不同预后组患儿初诊时BMMNC中AS表达水平差异及其与预后的关系.结果 未缓解组患儿AS表达水平最高,表达水平中位值为17.25(2.48～46.82),复发组其次,为14.28(3.20～54.47),持续完全缓解组患儿AS表达水平最低,为5.08(0.84～54.92),三组比较差异有统计学意义(P＜0.05).合并未缓解和复发两组患儿,其中位AS mRNA水平为14.93(2.48～54.47),显著高于持续完全缓解组患JL(P＜0.01).AS低表达组患儿白血病持续完全缓解率为84.6%,而AS高表达组患儿持续完全缓解率仅为53.8%(P＜0.05).AS高表达组患儿的2年预计无病生存率为51.6%,显著低于AS低表达组患儿(84.6%)(P＜0.05).结论 AS高表达与患儿预后不良相关.     

Lack of cardioprotection from metabolic support with glutamine or glutamate in a porcine coronary occlusion model

Objective Previous experimental studies indicate that glutamine or glutamate may provide cardioprotection by improving the oxidative metabolism in myocardial ischemia. We investigated the effect of glutamine or glutamate, given during reperfusion, on resulting infarct size and hemodynamic recovery.

Design A porcine coronary occlusion model was applied. Infusions were initiated 15 min before reperfusion and supplemented with intracoronary bolus doses at reperfusion. The primary outcome measure was infarct size in relation to area at risk determined by a standard tissue staining procedure. Secondary outcome measures were the hemodynamic variables.

Results The infarct sizes as a proportion of the area at risk (mean±SD) were: control group, 0.64±0.19 (n=9); glutamine group, 0.87±0.07 (p<0.05 vs control group) (n=8); glutamate group, 0.72±0.11 (n=9). Glutamine increased systemic vascular resistance, while glutamate preserved cardiac output during infusion.

Conclusion Substrate supplementation with the anaplerotic precursors glutamine and glutamate is ineffective as adjunctive therapy for severe myocardial ischemia. Beneficial effects documented in less complex experimental systems could not be transferred to a more pathophysiological relevant model.     

Splicing variants in NARS2 are associated with milder phenotypes and intra-familial variability

Biallelic rare variants in NARS2 that encode the mitochondrial asparaginyl-tRNA synthetase are associated with a wide spectrum of clinical phenotypes ranging from severe neurodegenerative disorders to isolated mitochondrial myopathy or deafness. To date, only a small number of patients with NARS2 variants have been reported, and possible genotype-phenotype correlations are still lacking. Here, we present three siblings who had an early-onset hearing loss, while one developed severe symptoms in adulthood associated with early intellectual impairment, refractory seizures, moderate axonal sensorimotor neuropathy, and atypical psychiatric symptoms. Biochemical analysis revealed impairment of the activity and assembly of the respiratory chain complexes in this patient's muscle and fibroblasts. Whole Exome Sequencing allowed identification of a heterozygous variant NM_024678.5(NARS2):c.822G > C (p.Gln274His) that is known to be pathogenic and to affect splicing of the NARS2 gene, but was unable to detect a second variant in this gene. Coverage analysis and Sanger sequencing led to identification of a novel intronic deletion NM_024678.5(NARS2):c.922-21_922-19del in the three siblings in trans with the c.822G > C. Functional analysis by RT-PCR showed that this deletion was causing aberrant splicing and led to exon 9 skipping in NARS2 mRNA in patient fibroblasts. Our work expands the phenotype and genotype spectrum of NARS2-related disorders. We provide evidence of the pathogenic effect of a novel intronic deletion in the NARS2 gene and report on additional adult patients with a large intrafamilial variability associated with splice variants in this gene. More specifically, we detail the phenotype of the oldest living patient to date with NARS2 variants and, for the first time, we report the psychiatric symptoms associated with this gene. Our work confirms the complexity of genotype-phenotype correlation in patients with pathogenic NARS2 variants.     

Long-term effect of heme oxygenase (HO)-1 induction in glomerular immune injury

In a rat model of macrophage-dependent glomerular immune injury induced by administration of antibody against the glomerular basement membrane (anti-GBM), the authors assessed the anti-proteinuric effect of Heme Oxygenase-1 (HO-1) induction. Rats received anti-GBM antibody alone, anti-GBM antibody and treatment with the HO-1 inducer, hemin, or non-immune serum (controls). Urine protein, creatinine, and nitrite/nitrate excretion were measured on days 5, 7, and 14 after administration of the anti-GBM antibody. In hemin-treated animals with anti-GBM antibody-induced immune injury, HO-1 immunolocalized in macrophages infiltrating glomeruli and in tubular epithelial cells. In these animals, proteinuria was decreased. There was also a decrease in blood urea nitrogen (BUN) levels without a change in serum creatinine or systemic blood pressure. The observations establish the anti-proteinuric effect of hemin induction. This effect could be mechanistically linked to blunting of the ability of infiltrating macrophages to cause injury or to changes in tubular handling of filtered protein.     

Reduced subcortical glutamate/glutamine in adults with autism spectrum disorders: a [1H]MRS study

Dysfunctional glutamatergic neurotransmission has been implicated in autism spectrum disorder (ASD). However, relatively few studies have directly measured brain glutamate in ASD adults, or related variation in glutamate to clinical phenotype. We therefore set out to investigate brain glutamate levels in adults with an ASD, comparing these to healthy controls and also comparing results between individuals at different points on the spectrum of symptom severity. We recruited 28 adults with ASD and 14 matched healthy controls. Of those with ASD, 15 fulfilled the ‘narrowly'' defined criteria for typical autism, whereas 13 met the ‘broader phenotype''. We measured the concentration of the combined glutamate and glutamine signal (Glx), and other important metabolites, using proton magnetic resonance spectroscopy in two brain regions implicated in ASD—the basal ganglia (including the head of caudate and the anterior putamen) and the dorsolateral prefrontal cortex—as well as in a parietal cortex ‘control'' region. Individuals with ASD had a significant decrease (P<0.001) in concentration of Glx in the basal ganglia, and this was true in both the ‘narrow'' and ‘broader'' phenotype. Also, within the ASD sample, reduced basal ganglia Glx was significantly correlated with increased impairment in social communication (P=0.013). In addition, there was a significant reduction in the concentration of other metabolites such as choline, creatine (Cr) and N-acetylaspartate (NAA) in the basal ganglia. In the dorsolateral prefrontal cortex, Cr and NAA were reduced (P<0.05), although Glx was not. There were no detectable differences in Glx, or any other metabolite, in the parietal lobe control region. There were no significant between-group differences in age, gender, IQ, voxel composition or data quality. In conclusion, individuals across the spectrum of ASD have regionally specific abnormalities in subcortical glutamatergic neurotransmission that are associated with variation in social development.     

脂肪酸合成酶在大肠癌中的表达及临床意义

[目的]研究脂肪酸合成酶(FAS)在大肠癌的表达状况及临床意义.[方法]用免疫组织化学染色法观察47例大肠癌中的FAS表达情况,并与Dukes分期进行比较,同时比较FAS的表达与病人生存率的关系.[结果]47例大肠癌中FAS阳性表达率为70.21%(33/47),FAS的表达与Duke's分期呈正相关,但与总体生存率无关.[结论]FAS在大肠癌呈高表达,FAS不能作为大肠癌独立的预后指标.     

Lens cholesterol biosynthesis inhibition: A common mechanism of cataract formation in laboratory animals by pharmaceutical products

CJ‐12,918, a 5‐lipoxygenase (5‐LO) inhibitor, caused cataracts during a 1‐month safety assessment studies in rats whereas the structurally similar ZD‐2138 was without effect. For CJ‐12,918 analogs, blocking different sites of metabolic liability reduced (CJ‐13,454) and eliminated (CJ‐13,610) cataract formation in both rats and dogs. Using this chemical series as a test set, models and mechanisms of toxicity were first explored by testing the utility of ex vivo rat lens explant cultures as a safety screen. This model overpredicted the cataractogenic potential of ZD‐2138 due to appreciably high lens drug levels and was abandoned in favor of a mechanism‐based screen. Perturbations in lens sterol content, from a decline in lathosterol content, preceded cataract formation suggesting CJ‐12,918 inhibited lens cholesterol biosynthesis (LCB). A 2‐day bioassay in rats using ex vivo LCB assessments showed that the level of LCB inhibition was correlated with incidence of cataract formation in animal studies by these 5‐LO inhibitors. Thereafter, this 2‐day bioassay was applied to other pharmaceutical programs (neuronal nitric oxide synthase, sorbitol dehydrogenase inhibitor, squalene synthetase inhibitor and stearoyl‐CoA desaturase‐1 inhibitors/D₄ antagonists) that demonstrated cataract formation in either rats or dogs. LCB inhibition >40% was associated with a high incidence of cataract formation in both rats and dogs that was species specific. Bioassay sensitivity/specificity were further explored with positive (RGH‐6201/ciglitazone/U18666A) and negative (tamoxifen/naphthalene/galactose) mechanistic controls. This body of work over two decades shows that LCB inhibition was a common mechanism of cataract formation by pharmaceutical agents and defined a level of inhibition >40% that was typically associated with causing cataracts in safety assessment studies typically ≥1 month.     

Systematic Review of l-glutamine for Prevention of Vaso-occlusive Pain Crisis in Patients with Sickle Cell Disease

l -glutamine was approved by the U.S. Food and Drug Administration (FDA) for sickle cell disease (SCD) in 2017. A vaso-occlusive crisis (VOC) occurs in persons with SCD and is associated with acute pain episodes. This systematic review summarizes the evidence for l -glutamine in the prevention of VOC and associated pain in patients with SCD. Medline, Embase, and International Pharmaceutical Abstracts were searched for records reporting on l -glutamine use in persons with SCD. Eligibility criteria identified primary reports of investigations conducted in humans who were administered l -glutamine, reported on outcomes related to VOC or associated pain, published in English, and were available as full text. All relevant efficacy, safety, participant demographic data, and study method characteristics were extracted and documented. Risk-of-bias assessments were conducted using the Risk of Bias in Non-Randomized Studies-of Interventions (ROBINS-I) tool and the revised Cochrane risk-of-bias tool for randomized studies. Three studies assessing the effect of exogenous l -glutamine administration in patients with SCD met eligibility criteria: one prospective nonrandomized controlled study and two prospective randomized controlled trials. Rate of VOC and related hospitalizations were reduced in patients receiving l -glutamine, although some conflicting results were noted between studies. l -glutamine was generally well tolerated. Limitations of one or more of the eligible studies included small sample size, nonblinding, and study groups that differed at baseline. l -glutamine has limited high-quality evidence supporting its use. Although l -glutamine is FDA approved for the prevention of frequent episodes of VOC pain, only one randomized controlled trial has strong evidence to support this indication. Based on the results of a systematic review, l -glutamine may be considered for patients unable to receive hydroxyurea or in addition to hydroxyurea for reduction in VOC and associated pain.     

2型糖尿病大鼠血浆同型半胱氨酸与阴茎海绵体内NOS和内源性CO的相关性研究

目的:研究2型糖尿病性大鼠血浆同型半胱氨酸(Hcy)与阴茎海绵体内NOS和内源性CO的相关性。方法:选取3月龄雄性Wistar大鼠50只,随机选取10只为对照组(A组);高糖高脂饲料饲养4周后从其他40只大鼠中筛选出30只构建成功的糖尿病(DM)大鼠模型,随机分成3组:DM大鼠组(B组);胰岛素治疗组(C组)和叶酸+维生素B12治疗组(D组)。8周及12周后注射阿朴吗啡观察各组大鼠阴茎勃起情况。12周后测各组大鼠血浆总Hcy含量及阴茎海绵体内NOS活性和CO含量。结果:与A组比较,B组大鼠血浆Hcy浓度明显升高,阴茎勃起功能明显降低,阴茎海绵体NOS活性和CO含量均下降,差异有显著性(P<0.01)。2型DM大鼠中高Hcy血症发生率为55%。与B组比较,C组和D组中大鼠血浆Hcy浓度显著下降,阴茎勃起功能、阴茎海绵体NOS活性均升高(P<0.01),Hcy与NOS(rA=-0.89,rB=-0.76,rC=-0.91,rD=-0.91)及CO含量(rA=-0.82,rB=-0.77,rC=-0.93,rD=-0.81)均呈负相关。结论:2型DM大鼠血浆中的高Hcy可能是引起阴茎海绵体NOS活性下降、CO含量下降,进而导致DM ED发病的分子机制之一。胰岛素、叶酸和维生素B12可以改善DM大鼠的勃起功能,提高阴茎海绵体NOS活性和CO含量。     

Universal monoclonal antibody-based influenza hemagglutinin quantitative enzyme-linked immunosorbent assay

Seasonal and pandemic influenza infections remain a serious public health concern. Many health authorities recommend annual vaccination as the most effective way to control influenza infection. Accordingly, regulatory guidelines ask vaccine manufacturers to determine vaccine potency at the time of release and throughout shelf-life to ensure vaccine quality. The potency of inactivated influenza vaccine is related to the quantity of hemagglutinin (HA). Since 1970s, single radial immunodiffusion (SRID) assay has been standardly used for the quantitation of HA in influenza vaccine. However, SRID is labor-intensive, inaccurate, and requires standard reference reagents that should be updated annually. Therefore, there have been extensive efforts to develop alternative potency assays. In this study, we developed and tested a new HA quantitative enzyme-linked immunosorbent assay (ELISA) using a universal monoclonal antibody that can bind to HAs from various subtypes in group 1 influenza A virus (IAV). We analyzed the conserved stalk domain of HA via a library approach to design a consensus HA antigen for group 1 IAV. The antigens were expressed as a soluble form in E. coli and were purified by Ni-affinity chromatography. When tested with variety of HAs from IAVs or influenza B viruses (IBVs), the mAbs exhibited specific binding to group 1 HAs, with potential exception to H9 subtype. Among various conditions of pH, urea, and reducing agents, pretreatment of HA at low pH exposing the conserved stalk domain was crucially important for optimal ELISA performance. Calibration curves for various HAs were generated to determine accuracy, specificity, sensitivity, and linear dynamic range. The ELISA method shows high sensitivity and accuracy compared with the SRID assay. The HA group specific universal mAbs against the consensus stalk domain of HA are conducive to establishing an ELISA-based standard procedure for the quantitation of HA antigens for annual vaccination against influenza infection.