HIV-1包膜蛋白2G12和2F5中和表位的改造对假病毒形成及中和活性的影响

目的 研究HIV-1膜蛋白(Env)特定中和表位的改造对功能性假病毒形成及中和活性的影响.方法 采用环形诱变及Dpn I筛选的方法对Env进行定点突变,将2G12和2F5两个中和表位整合入不含该表位的BC亚型的Env上,比较改造对假病毒的形成情况及对2G12和2F5单抗的中和活性的影响.结果 对5株假病毒(BC02、BE03、BC04、BC05和BC12)的Env特定中和表位进行改造,其中BC04和BCl2的2G12表位改造后,不能形成假病毒,BC02、BC03和BC05增加2G12和2F5两个表位后,仍能够形成假病毒,且假病毒滴度较改造前无明显变化,改造后的BC03假病毒较改造前对单抗2G12和2175的中和活性均有所提高,而改造后的BE02和BC05假病毒较改造前对单抗2F5的中和活性增强,而对单抗2G12的中和活性无变化.结论 2G12中和表位部分位点的改造影响假病毒的形成,中和表位的增加能够提高单抗2G12的中和活性,为免疫原的优化提供了新思路.     

Stressful life events precede exacerbations of multiple sclerosis

OBJECTIVE: We longitudinally monitored life events and health changes in patients with multiple sclerosis (MS) to determine whether stressful events may trigger exacerbation of MS. METHODS: Twenty-three women with MS were followed for 1 year. Each subject completed the Psychiatric Epidemiologic Research Interview on a weekly basis. Further information on potentially stressful events was acquired using the Life Events and Difficulties Schedule. Neurologic symptoms were also monitored on a weekly basis throughout the year. Potential MS exacerbations were confirmed by a neurologist who was blind to the presence and timing of stressors. RESULTS: Eighty-five percent of MS exacerbations were associated with stressful life events in the preceding 6 weeks. Stressful life events occurred an average of 14 days before MS exacerbations, compared with 33 days before a randomly selected control date (p < .0001). Survival analysis confirmed that an increase in frequency of life events was associated with greater likelihood of MS exacerbations (hazard ratio = 13.18, p < .05). CONCLUSIONS: These results are consistent with the hypothesis that stress is a potential trigger of disease activity in patients with relapsing-remitting MS.     

Eosinophil-fibroblast interactions induce fibroblast IL-6 secretion and extracellular matrix gene expression: implications in fibrogenesis

BACKGROUND: Eosinophils are frequently associated with tissue remodeling and fibrosis in allergic and other diseases and animal models. Their close physical proximity to fibroblasts at sites of tissue remodeling strongly implicates them in fibrogenesis, including subepithelial fibrosis and airway remodeling characteristic of asthma. OBJECTIVE: To identify the mediators and characterize the mechanisms underlying the fibrogenic activities of eosinophils. METHODS: A coculture system of blood eosinophils or eosinophil cell lines with normal fibroblasts was used to assess their ability to induce a fibrogenic fibroblast phenotype, including IL-6 secretion and mRNA expression, and induction of genes involved in extracellular matrix production and homeostasis. The mediators of these responses were identified by using transwell barrier cocultures, eosinophil-conditioned media, and cytokine-specific antibody neutralization. RESULTS: Eosinophil-fibroblast coculture induced potent fibroblast IL-6 secretion and mRNA expression, responses further enhanced by IL-5. The soluble nature of the eosinophil-derived mediators was demonstrated by using eosinophil-fibroblast coculture in the presence of permeable transwell barriers, and fibroblast culture in eosinophil-conditioned media, indicating that cell contact was not required. Induction of fibroblast IL-6 expression was accompanied by increased expression of fibronectin and the extracellular matrix regulatory genes plasminogen activator inhibitor 1 and tissue inhibitor of metalloproteinase 1. Antibody neutralization identified the principal eosinophil-derived mediator of fibroblast IL-6 expression as IL-1beta (>60%), with lesser contributions from IL-1alpha, IL-4, and TGF-beta (10% to 20%). CONCLUSION: Eosinophils express at least 2 potent mediators (IL-1beta and TGF-beta) that induce a fibrogenic fibroblast phenotype, strongly supporting a role for the eosinophil in the dysregulation of extracellular matrix homeostasis and consequent tissue remodeling and fibrosis in eosinophil-associated diseases.     

Integration of stakeholder engagement from development to dissemination in genomic medicine research: Approaches and outcomes from the CSER Consortium

PurposeThere is a critical need for genomic medicine research that reflects and benefits socioeconomically and ancestrally diverse populations. However, disparities in research populations persist, highlighting that traditional study designs and materials may be insufficient or inaccessible to all groups. New approaches can be gained through collaborations with patient/community stakeholders. Although some benefits of stakeholder engagement are recognized, routine incorporation into the design and implementation of genomics research has yet to be realized.MethodsThe National Institutes of Health–funded Clinical Sequencing Evidence-Generating Research (CSER) consortium required stakeholder engagement as a dedicated project component. Each CSER project planned and carried out stakeholder engagement activities with differing goals and expected outcomes. Examples were curated from each project to highlight engagement strategies and outcomes throughout the research lifecycle from development through dissemination.ResultsProjects tailored strategies to individual study needs, logistical constraints, and other challenges. Lessons learned include starting early with engagement efforts across project stakeholder groups and planned flexibility to enable adaptations throughout the project lifecycle.ConclusionEach CSER project used more than 1 approach to engage with relevant stakeholders, resulting in numerous adaptations and tremendous value added throughout the full research lifecycle. Incorporation of community stakeholder insight improves the outcomes and relevance of genomic medicine research.     

Morphological analysis of degeneration and regeneration of syncytiotrophoblast in first trimester placental villi during organ culture

We have recently shown using dansyl-L-lysine exclusion studies that the release of human chorionic gonadotrophin (HCG) in conjunction with L- lactate dehydrogenase (LDH) from first trimester villi during organ culture is symptomatic of syncytiotrophoblast degeneration. The purpose of this study was to examine chorionic villi at the ultrastructural level in order to determine events occurring during organ culture. The tissue was sampled after 0, 24, 48 and 120 h in culture and processed for electron microscopy. In addition to confirming the previously recorded syncytial degeneration, the electron micrographs showed clearly the generation of a new syncytiotrophoblast layer. The new layer, derived from differentiating cytotrophoblast cells, was largely formed by 48 h and was maintained for at least 120 h in culture. This study demonstrates a model which provides an opportunity to study the differentiation of cytotrophoblast cells whilst they retain their anatomical relationships within the villous structure.      

A second locus (GLC3B) for primary congenital glaucoma (Buphthalmos) maps to the 1p36 region

Primary congenital glaucoma (gene symbol: GLC3) is an ocular disorder that occurs for 0.01-0.04% of blind people. In the majority of familial cases reported so far, this condition is inherited as an autosomal recessive trait. We have recently used a group of 17 GLC3 families with a minimum of two affected offspring and consanguinity in most of the parental generation and mapped the first GLC3 locus (GLC3A) to the 2p21 region. Six families did not show any linkage to the GLC3A locus and thus provided evidence for genetic heterogeneity of this disorder. A total of eight families unlinked to the 2p21 region were used to search for the chromosomal location of the second GLC3 locus. Herein, we describe mapping of a new locus (designated GLC3B) for primary congenital glaucoma to the short arm of chromosome 1 (1p36.2-36.1) that is situated centromeric to the neuroblastoma and Charcot-Marie-Tooth type 2A (CMT2A) loci. A total of 17 DNA markers were genotyped from this region of chromosome 1. Four families showed no recombination with the two markers D1S2834 and D1S402 with a maximum lod score of 4.510 and 4.157 respectively. Pairwise and multipoint linkage analysis and inspection of the haplotypes revealed that the remaining four families are not linked to this part of chromosome 1, thus providing further evidence that at least one more locus for the autosomal recessive form of GLC3 must exist in the genome. Based on the recombination events, the overall linkage map of this region is: tel-D1S1192-D1S1635-D1S1193 - (D1S1597/-D1S489/D1S228)- [GLC3B/D1S2834/D1S402] - (D1S1176/D1S507/D1S407) - D1S2728-(MFAP2/D1S170) - D1S1368 - D1S436- D1S1592-cen.      

46, XY gonadal dysgenesis: new SRY point mutation in two siblings with paternal germ line mosaicism

Stoppa‐Vaucher S, Ayabe T, Paquette J, Patey N, Francoeur D, Vuissoz J‐M, Deladoëy J, Samuels ME, Ogata T, Deal CL. 46, XY gonadal dysgenesis: new SRY point mutation in two siblings with paternal germ line mosaicism. Familial recurrence risks are poorly understood in cases of de novo mutations. In the event of parental germ line mosaicism, recurrence risks can be higher than generally appreciated, with implications for genetic counseling and clinical practice. In the course of treating a female with pubertal delay and hypergonadotropic hypogonadism, we identified a new missense mutation in the SRY gene, leading to somatic feminization of this karyotypically normal XY individual. We tested a younger sister despite a normal onset of puberty, who also possessed an XY karyotype and the same SRY mutation. Imaging studies in the sister revealed an ovarian tumor, which was removed. DNA from the father's blood possessed the wild type SRY sequence, and paternity testing was consistent with the given family structure. A brother was 46, XY with a wild type SRY sequence strongly suggesting paternal Y‐chromosome germline mosaicism for the mutation. In disorders of sexual development (DSDs), early diagnosis is critical for optimal psychological development of the affected patients. In this case, preventive karyotypic screening allowed early diagnosis of a gonadal tumor in the sibling prior to the age of normal puberty. Our results suggest that cytological or molecular diagnosis should be applied for siblings of an affected DSD individual.     

Dysregulated mTORC1 renders cells critically dependent on desaturated lipids for survival under tumor-like stress

Solid tumors exhibit heterogeneous microenvironments, often characterized by limiting concentrations of oxygen (O₂), glucose, and other nutrients. How oncogenic mutations alter stress response pathways, metabolism, and cell survival in the face of these challenges is incompletely understood. Here we report that constitutive mammalian target of rapamycin complex 1 (mTORC1) activity renders hypoxic cells dependent on exogenous desaturated lipids, as levels of de novo synthesized unsaturated fatty acids are reduced under low O₂. Specifically, we demonstrate that hypoxic Tsc2^−/− (tuberous sclerosis complex 2^−/−) cells deprived of serum lipids exhibit a magnified unfolded protein response (UPR) but fail to appropriately expand their endoplasmic reticulum (ER), leading to inositol-requiring protein-1 (IRE1)-dependent cell death that can be reversed by the addition of unsaturated lipids. UPR activation and apoptosis were also detected in Tsc2-deficient kidney tumors. Importantly, we observed this phenotype in multiple human cancer cell lines and suggest that cells committed to unregulated growth within ischemic tumor microenvironments are unable to balance lipid and protein synthesis due to a critical limitation in desaturated lipids.     

脊柱骨巨细胞瘤误诊1例

发生于骶骨以上的脊柱骨巨细胞瘤罕见[1],关于其CT表现仅见零星个案报道。我院误诊1例,报告如下。患者男性,20岁。胸背部疼痛2月,加重伴双下肢麻木10天入院。病史中无明显咳嗽、潮热、盗汗现象。外院X线及CT提示第5胸椎体结核伴椎旁冷脓肿形成。专科检查:胸椎活动受限,尤以屈曲位为明显,第5胸椎处叩压痛明显,局部无明显畸形及包块,剑突平面以下痛觉略减退,双下肢踝阵挛阳性,双膝反射、踝反射亢进。实验室检查:肝功、肾功、电解质、CEA、AFP及血、尿常规均无异常,入院时ESR:41mm/h,1周后复查ESR:16mm/h,2周后复查ESR:37mm/h。影像表…