西罗莫司靶蛋白信号传导通路与肾脏足细胞自噬的研究进展

近些年来,随着人们对肾脏足细胞自噬研究的不断深入,越来越多的自噬信号通路被发现.其中,以西罗莫司靶蛋白(mTOR)介导的自噬信号传导通路为自噬治疗靶点的方案逐渐成为研究热点.很多研究证明,mTOR信号传导通路在肾小球足细胞自噬的发生发展中起重要作用,mTOR是肾小球足细胞自噬调控的重要信号通路,也是肾小球足细胞营养状态的感受器.目前根据自噬调控机制的不同,国际上统一将自噬调控机制分为依赖mTOR途径的自噬调控机制和非依赖mTOR途径的自噬调控机制.肾小球足细胞mTOR的上下游信号传导通路较为复杂,mTOR作为生长因子、胰岛素、氨基酸等物质的感受器,对足细胞生长发育起重要的调节作用.因此,mTOR活化介导的自噬在肾小球足细胞损伤中起重要作用,mTOR信号传导通路可能成为干预肾小球足细胞损害的一种潜在治疗方法.     

哺乳动物雷帕霉素靶蛋白在阿霉素诱导足细胞损伤中的作用

目的 探讨哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)复合体在阿霉素损伤足细胞中的作用.方法 用1 μmol/L的阿霉素(adriamycin,ADM)诱导小鼠足细胞24 h,检测足细胞活力、足细胞凋亡比例、足细胞损伤标志物结蛋白(Desmin)和mTOR相关分子的表达,分析mTOR复合体在ADM损伤足细胞中的作用.结果 (1)1μmol/L的ADM诱导足细胞24h,可使足细胞损伤.与对照组比较,足细胞活性下降(t =28.68,P＜0.001),足细胞早期凋亡比例增加(t=10.24,P=0.09),晚期凋亡比例也增加(t =-4.26,P=0.013);损伤标志分子Desmin表达增多(t=6.16 P＜0.001);(2) ADM诱导组足细胞mTOR蛋白表达下降,与对照组比较,mTOR和磷酸化mTOR表达均下降(t=3.57,P=0.023),mTOR下游分子S6K1和4EBP1 mRNA表达下降(t=18.28,P＜0.001).结论 ADM可诱导足细胞损伤,ADM损伤足细胞的机制可能与mTOR蛋白减少、活性下降有关.     

肾小球足细胞内的蛋白质降解机制

足细胞在维系肾小球滤过屏障的选择通透性方面有重要作用,而足细胞损伤导致的蛋白尿则足肾小球疾病的重要标志足细胞胞质内中主要有2种蛋白降解途径:自噬系统和泛索蛋白酶体系统.了解蛋白降解机制变化对足细胞的影响,期望为今后肾脏疾病的治疗提供可靠依据.     

肾小球足细胞生理功能与致损伤因素

近年来对足细胞在维持肾小球滤过屏障和肾功能的作用研究逐步深入.研究证实,足细胞是多种肾小球疾病免疫或非免疫损伤的靶标,多种类型的肾小球疾病均特征性地表现为足细胞异常.足细胞损伤往往会引起肾小球滤过膜结构和功能异常,从而导致蛋白尿的产生.深入认识足细胞的生理功能及致损伤因素,对于临床有效防治肾小球损伤性疾病有重要意义.     

mTOR信号通路在孤独症谱系障碍中的研究进展

哺乳动物雷帕霉素靶蛋白（mTOR）为细胞内信号通路转导分子,调节很多重要的生理过程。mTOR信号通路在神经系统的突触可塑性、信息传递和加工、神经调控等方面发挥重要作用。mTOR信号通路失调被认为与孤独症谱系障碍（ASD）的发病机制有关,mTOR抑制剂可以改善ASD的症状。本文对mTOR信号通路在ASD发病机制中的作用进行综述,以期为ASD的靶向治疗提供理论依据。     

Th17、Treg及足细胞损伤与原发性肾小球疾病研究进展

近年来辅助性T细胞17(T helper cell,Th17)、调节性T细胞(regulatory T cell,Treg)、足细胞损伤在原发性肾小球疾病发病机制中的作用受到广泛关注。 Th17细胞通过分泌IL-17等细胞因子,具有招募中性粒细胞和巨噬细胞到感染部位的功能;Treg细胞具有免疫调节功能,介导免疫耐受,保护机体免受炎症损伤。 Th17细胞比例升高、Treg细胞比例下降引起的失衡在原发性肾小球疾病的发病机制及病情进展中可能起到重要作用。足细胞作为肾小球滤过屏障的重要组成部分,近年来成为研究热点。深入探讨Th17、Treg以及足细胞损伤与原发性肾小球疾病的关系,可为原发性肾小球疾病的防治寻找新的靶点提供依据。     

足细胞损伤与肾脏疾病的研究进展

近年来足细胞成为肾脏病学的研究热点之一.足细胞损伤在肾小球疾病的发生发展过程中起着关键性作用,对足细胞分子生物学和病理学的深入认识将为相关肾病的防治提供新的思路.该文就足细胞生物学、足细胞损伤与肾小球疾病及其干预的研究进展作一综述.     

特发性塌陷性肾小球病

特发性塌陷性肾小球病是一严重肾损伤类型,与非人类免疫缺陷病毒感染(如细小病毒B19)、免疫性疾病以及某些药物相关。肾小球塌陷的机制还不清楚,可能与足细胞表型异常调节致足细胞激活并进入细胞增殖周期有关。该病的主要病理特征为肾小球毛细血管袢塌陷伴肾小球上皮细胞肥大、增生和明显的肾小管.间质损伤。临床主要表现为肾病综合征,并迅速进展到肾功能不全,对激素耐药,预后不良。     

B7/CD28共刺激分子参与肾脏疾病的免疫机制研究进展

机体特异性免疫应答是一个需要一系列免疫细胞和免疫分子共同参与的异常复杂的过程,这些免疫细胞及分子之间相互调节又相互制约。目前大多数肾脏疾病发病机制尚不明确。B7(CD80)位于调节CD4+和CD8+T细胞的抗原提呈细胞上,通过与细胞上的糖蛋白CD28结合发挥信号传递作用、增强或放大免疫反应的功能,或者与细胞毒性T细胞蛋白-4(cytotoxic T lymphocyte-associated antigen4 CTLA-4)结合后抑制免疫应答。通常肾组织不表达或低表达B7,然而某些肾小球疾病的发生与B7的增加有关,其降低了足细胞附着肾小球基底膜的能力,增加炎症反应及肾脏纤维化。当B7与CTLA-4相结合时,免疫反应就会被减弱。因此通过阻断CD28或增强CTLA-4信号可能阻止疾病的发生。该文就共刺激分子B7/CD28在足细胞损伤、原发性肾小球肾炎、紫癜性肾炎、狼疮性肾炎等肾脏疾病的发病机制中的作用,以及B7阻滞剂在部分肾脏疾病靶向治疗的研究进展进行综述。     

TRPC6与肾脏疾病关系的研究进展

瞬时受体电位阳离子通道蛋白6（TRPC6）是由TRPC6基因编码的瞬时受体超家族成员之一,在人体内各组织或器官广泛表达,在肾小球足细胞也有表达。TRPC6与podocin、nephrin、ACTN4及CD2AP等多种裂孔隔膜（SD）蛋白相互作用共同维系肾小球足细胞的结构及功能。多因素作用导致肾小球足细胞损伤引起SD的足突融合是肾脏疾病最主要的形态学改变。该文就TRPC6生物学功能及其对肾脏疾病的影响作一简述。     

Allergic factors associated with the development of asthma and the influence of cetirizine in a double-blind, randomised, placebo-controlled trial: First results of ETA®

There is a common progression known as the allergic march from atopic dermatitis to allergic asthma. Cetirizine has several antiallergic properties that suggest a potential effect on the development of airway inflammation and asthma in infants with atopic dermatitis. Methods. Over a two year period, 817 infants aged one to two years who suffered from atopic dermatitis and with a history of atopic disease in a parent or sibling were included in the ETAC^® (Early Treatment of the Atopic Child) trial, a multi-country, double-blind, randomised, placebo-controlled trial. The infants were treated for 18 months with either cetirizine (0.25mg/ kg b.i.d.) or placebo. The number of infants who developed asthma was compared between the two groups. Clinical and biological assessments including analysis of total and specific IgE antibodies were performed. Results. In the placebo group, the relative risk (RR) for developing asthma was elevated in patients with a raised level of total IgE (≥ 30 kU/I) or specific IgE (≥ 0.35 kUA/I) for grass pollen, house dust mite or cat dander (RR between 1.4 and 1.7). Compared to placebo, cetirizine significantly reduced the incidence of asthma for patients sensitised to grass pollen (RR = 0.5) or to house dust mite (RR = 0.6). However, in the population that included all infants with normal and elevated total or specific IgE (intention-to-treat - ITT), there was no difference between the numbers of infants developing asthma while receiving cetirizine or placebo. The adverse events profile was similar in the two treatment groups. Discussion. Raised total IgE level and raised specific IgE levels to grass pollen, house dust mite or cat dander were predictive of subsequent asthma. Cetirizine halved the number of patients developing asthma in the subgroups sensitised to grass pollen or house dust mite (i.e. 20% of the study population). In view of the proven safety of the drug, we propose this treatment as a primary pharmacological intervention strategy to prevent the development of asthma in specifically sensitised infants with atopic dermatitis.     

�¶�֢��ϵ�ϰ���ע��ȱ�ݶද�ϰ������ڵ�ת��

孤独症谱系障碍(autistic-spectrum disorders,ASDs)近年来患病率逐年攀升至1%左右,其症状往往伴随终生,成为严重威胁儿童健康和发展的神经发育性疾患;注意缺陷多动障碍(attention deficit hyperactivity disorder,ADHD)是儿童期最常见的精神障碍,国内报道患病率为4.13%～5.83%,其症状可延续至青少年期,甚至到成年期[1]。这两类精神障碍在成年期的临床表现、共患病、治疗策略和预后与儿童期有哪些不同呢?本文通过回顾相     

EXCITING NEW TREATMENT APPROACHES FOR PATHYPHYSIOLOGIC MECHANISMS OF SICKLE CELL DISEASE

During the past several decades, our understanding of the complex pathophysiology of vasoocclusion associated with sickle cell disease has improved greatly. Interaction of genes, hemoglobin molecules, red cell membrane and metabolic changes, cell-cell interactions and cell-plasma interactions, red cell adhesion to vascular endothelium, activation of coagulation, and vascular reactivity play a role in vaso occlusion. Penicillin prophylaxis of pneumococcal infections and appropriate use of blood transfusions and other supportive measures improved survival of sickle cell patients. Hydroxyurea made a major impact on sickle cell therapy when it was shown to decrease acute painful episodes, acute chest syndrome, and the need for blood transfusion in adults. Significant experience in the use of hydroxyurea has been accumulated in older children. The benefits and risks of hydroxyurea for younger children and long-term risks in all patients will be evaluated in future investigations. Other promising therapies include butyrate compounds, clotrimazole, magnesium supplementation, poloxamer 188, antiadhesion agents, anticoagulant approaches, and nitric oxide. Hemopoietic transplantation remains the only curative therapy. However, several transgenic mouse models are available for studies of gene therapy or other treatment approaches on biochemical, cellular, and pathologic effects of mutant genes.     

Infiltrations of Epstein-Barr virus-carrying cells in granular lymphocyte-proliferative disorders corresponding to chronic active Epstein-Barr virus infection

A 21-year-old man with granular lymphocyte-proliferative disorders (GLPD) associated with chronic active Epstein-Barr virus (EBV) infection is described. Chromosomal analyses revealed several clonal abnormalities and two of them were mainly repetitious. High copy numbers of monoclonal EBV genome were also detected in the proliferative large granular lymphocytes (LGLs), indicating the monoclonal expansion of EBV-infected LGLs. The patient had an indolent course for several years, and there was no evidence of infiltrations of his bone marrow until the end stage. At autopsy, microscopic studies revealed marked infiltrations of LGL in the liver and spleen, and the infiltrating cells were NK-cell immunophenotype. The infiltrated LGLs showed latency I.     

LUTEINIZING HORMONE RECEPTOR MUTATIONS IN DISORDERS OF SEXUAL DEVELOPMENT AND CANCER

Human male sexual development is regulated by chorionic gonadotropin (CG) and luteinizing hormone (LH). Aberrant sexual development caused by both activating and inactivating mutations of the human luteinizing hormone receptor (LHR) have been described. All known activating mutations of the LHR are missense mutations caused by single base substitution. The most common activating mutation is the replacement of Asp-578 by Gly due to the substitution of A by G at nucleotide position 1733. All activating mutations are present in exon 11 which encodes the transmembrane domain of the receptor. Constitutive activity of the LHR causes LH releasing hormone-independent precocious puberty in boys and the autosomal dominant disorder familial male-limited precocious puberty (FMPP). Both germline and somatic activating mutations of the LHR have been found in patients with testicular tumors. Activating mutations have no effect on females. The molecular genetics of the inactivating mutations of the LHR are more variable and include single base substitution, partial gene deletion, and insertion. These mutations are not localized and are present in both the extracellular and transmembrane domain of the receptor. Inactivation of the LHR gives rise to the autosomal recessive disorder Leydig cell hypoplasia (LCH) and male hypogonadism or male pseudohermaphroditism. Severity of the clinical phenotype in LCH patients correlates with the amount of residual activity of the mutated receptor. Females are less affected by inactivating mutation of the LHR. Symptoms caused by homozygous inactivating mutation of the LHR include polycystic ovaries and primary amenorrhea.     

Resurgence of measles in Singapore: profile of hospital cases

OBJECTIVE: To ascertain the profile of cases of measles seen at a general hospital during a recent outbreak that occurred despite a measles vaccination program. METHODOLOGY: A retrospective study from January 1991 to March 1998. All patients with measles (ICD code 055. 9) seen at the emergency unit or as inpatients were included. RESULTS: There were 87 cases identified. The diagnosis was clinical in all and proven serologically in 71%. Eighty-five per cent of the cases occurred between January 1997 and March 1998. There was a bi-modal age distribution with peaks in the very young (相似文献   

Personality profiles and heart rate variability (vagal tone) in children with recurrent abdominal pain

The aim of the study was to explore psychological factors and autonomic activity in children with recurrent abdominal pain and to compare them with those in a control group of healthy children. The Personality Inventory for Children was used for assessment of developmental, emotional and psychosocial factors in 25 children with recurrent abdominal pain (age, 7-15 y). Parasympathetic and sympathetic functions in these children and in 23 healthy control subjects (age, 7-13 y) were also investigated, non-invasively using a computerized polygraph. Vagal tone (parasympathetic function) was indexed by calculation of respiratory sinus arrhythmia in beats/min. Skin conductance (sympathetic function) was recorded by the constant current method. On the Personality Inventory for Children, 16 patients had high scores on somatic concern. Several patients had scores in the clinical range for depression, withdrawal and anxiety, but the mean scores for these personality profile scales were well within the normal range of healthy children. Interestingly, there was a spike on the L (Lie)-scale for most of the patients and 15 patients had scores above or close to the clinical cut-off value. As compared with the scores in healthy children, vagal tone and sympathetic tone were normal. Conclusion: Many children with recurrent abdominal pain have scores in the clinical range for depression, withdrawal, anxiety and L-scale indicating coping problems, denial and a trend towards somatic concern that may contribute to the evolution of abdominal pain. Autonomic nerve activity was not disturbed in these children.     

Overcoming surfactant inhibition with polymers

Inhibition of the function of pulmonary surfactant in the alveolar space is an important element of the pathophysiology of many lung diseases, including meconium aspiration syndrome, pneumonia and acute respiratory distress syndrome. The known mechanisms by which surfactant dysfunction occurs are (a) competitive inhibition of phospholipid entry into the surface monolayer (e.g. by plasma proteins), and (b) infiltration and destabilization of the surface film by extraneous lipids (e.g. meconium-derived free fatty acids). Recent data suggest that addition of non-ionic polymers such as dextran and polyethylene glycol to surfactant mixtures may significantly improve resistance to inhibition. Polymers have been found to neutralize the effects of several different inhibitors, and can produce near-complete restoration of surfactant function. The anti-inhibitory properties of polymers, and their possible role as an adjunct to surfactant therapy, deserve further exploration.     

Understanding infant formula

The World Health organisation recommends breast feeding infants for the first six months of life. When this breast feeding does not occur either through parental choice or medical need, infant formulas will be required. There is a bewildering array of formulas on the UK market for many different requirements. When faced with an unsettled infant many parents (and healthcare professionals) will experiment with the infant formula available and then attend the paediatric clinic looking for help and advice. It is therefore essential that paediatricians understand what milks are available and what the key differences between different products are. This review attempts to provide a simple guide through many of the formulations currently available in the UK; and offers advice for the dietary management of the child with extra calorie requirements, infants with cow's milk protein allergy, gastro oesophageal reflux disease, apparent unresolved hunger and infantile colic. Whatever the underlying condition, there is likely to be an infant formula that is suitable in this generation of ever expanding formulations.