维生素D与脓毒症关系的研究进展

正维生素D是一种脂溶性维生素,在调节钙磷代谢、维持骨骼生长发育等方面发挥着重要的生物学作用。近年来,人们发现维生素D除上述经典的生物学作用外,还可参与免疫调控,抗炎,抗感染等。脓毒症是机体对感染的反应失调而导致的严重器官功能障碍。免疫功能紊乱在脓毒症的发生     

第二讲 感染和抗感染的免疫

微生物进入机体,能否使机体致病,是一个复杂的过程。要从微生物及机体两方面来研究。一方面微生物依它自身情况感染机体;另一方面机体则根据微生物的不同而产生不同的功能抗感染。这种感染与抗感染的过程与免疫有密切关系。     

重症肺炎患者血清25-羟基维生素D水平及其影响因素分析

正研究认为机体的免疫功能紊乱在重症肺炎病程中起着重要作用~([1])。维生素D是一组具有生物活性的脂溶性类固醇衍生物,其活性形式之一25-羟基维生素D(25-OH Vit D)可调节机体代谢、免疫及炎症反应过程~([2,3])。Barker等~([4])报道患者血清25-OH Vit D水平低下与呼吸系统感染的病情严重程度存在一定相关性。Cava等~([5])认为低水平25-OH     

肺癌病人注射核糖酸出现过敏反应的抢救与护理

注射用核糖核酸(商品名BP素)用于肿瘤的辅助治疗、感染、免疫功能缺陷或低下及自身免疫性疾患疗效显著已被临床广泛应用。本品通过激活机体的细胞免疫和体液免疫两个系统产生特异性和非特异性免疫活性物质，抑制和调控免疫基因和致癌基因，调控并提高机体免疫功能。     

维生素D在肺部疾病中的作用

除了维持钙盐代谢和骨骼的稳态以外,研究发现维生素D还可调控包括机体防御,炎症,免疫,损伤修复等在内的多种生理和病理生理过程.流行病学资料表明,血清低水平的维生素D与肺功能受损、炎症反应和感染性疾病相关.因此,支气管哮喘、慢性阻塞性肺疾病和肺部感染性疾病都可能与维生素D水平有关,但具体的机制尚不明确.因此,本文通过文献回顾,概述维生素D在肺部疾病,包括支气管哮喘、慢性阻塞件肺疾病、肺结核和呼吸道感染中的作用.     

维生素D在肺部疾病中的作用

除了维持钙盐代谢和骨骼的稳态以外，研究发现维生素D还可调控包括机体防御，炎症，免疫，损伤修复等在内的多种生理和病理生理过程。流行病学资料表明，血清低水平的维生素D与肺功能受损、炎症反应和感染性疾病相关。因此，支气管哮喘、慢性阻塞性肺疾病和肺部感染性疾病都可能与维生素D水平有关，但具体的机制尚不明确。因此，本文通过文献回顾，概述维生素D在肺部疾病，包括支气管哮喘、慢性阻塞性肺疾病、肺结核和呼吸道感染中的作用。     

成纤维细胞生长因子23与维生素D的相互调节研究进展

成纤维细胞生长因子23（FGF23）是新近发现的主要由成骨细胞分泌的重要内分泌因子,参与机体钙、磷及维生素D代谢的调节;研究发现,活性维生素D除了经典的对骨和钙磷代谢的调节作用外,还具有免疫调节、抗炎、抗纤维化等功能[1,2],与人类很多疾病如衰老、肿瘤、自身免疫性疾病、     

巨噬细胞内脂滴在病原体感染中作用的研究进展

先天免疫系统是生物体在长期种系进化过程中逐渐形成的天然免疫防御体系。巨噬细胞是先天免疫细胞之一，在机体抗感染、抗肿瘤以及免疫调节等方面发挥重要作用。脂滴（LDs）是一种由单层磷脂膜构成的储脂细胞器，具有调控脂质代谢、能量稳态、合成和释放炎症介质以及介导免疫应答等功能。在一些病原体感染活化的巨噬细胞内经常观察到LDs累积现象，一方面LDs能够通过上调表面的抗微生物蛋白和肽类、合成脂类炎症介质等方式参与巨噬细胞对病原体的免疫炎症反应，另一方面某些病原体也可靶向LDs获取自身所需的营养物质和复制场所。考虑到目前抗菌药物耐药形势严峻，调控LDs的先天免疫有可能成为抗感染治疗新的策略。     

感染免疫与Th1／Th2漂移对抗肿瘤免疫的影响

动物免疫系统在机体健康状下Th1／Th2处于平衡状态,许多研究表明Th1／Th2漂移与肿瘤、自身免疫性疾病、微生物感染和移植排斥反应等多种疾病有关。Th1／Th2分化因子相互促进、相互制约。病原体侵入导致机体的这种平衡失调,产生抗感染反应。抗感染免疫长时间持续应答,也可以导致Th0,Th1,Th2细胞免疫功能紊乱。当免疫系统发生Th1／Th2漂移时,机体免疫被抑制,病原体或突变的细胞逃逸免疫监视。抗肿瘤免疫临床研究表明,有些恶性肿瘤患者经过手术切除肿瘤原发灶后,由于机体免疫系统处于抑制状态,肿瘤还是易复发。因此现在肿瘤免疫研究的热点是Th2向Th1方向的转移。细胞因子或免疫细胞和单克隆肿瘤抗体等与传统的手术、化疗、放疗结合起来,实现综合性治疗是各种恶性肿瘤研究的目的。感染免疫和Th1／Th2漂移相互作用机制以及肿瘤发生与复发关系的研究正在起步,现综述如下。     

多糖抗感染作用的研究进展

天然多糖广泛存在于植物、动物和微生物组织中,约有300多种。人们对多糖生物活性的研究可以追溯到1936年Shear对多糖抗肿瘤活性的发现[1]。多糖作为药物始于1943年[2],随着化学和生物学的快速发展和分离技术的提高,多糖的生物学功能,特别是多糖作为生命物质参与生命的全部时间和空间功能,如受精、着床、分化、发育、免疫、感染、癌变、衰老等等[3],突破了多糖作为支持组织和能量来源的传统观念。近年来,研究表明多糖具有广泛的生物活性而且作为药物具有低毒高效的优点,至今已报道其具有增强机体免疫功能、抗肿瘤、抗感染、抗衰老、降血糖、…     

The Role of Innate Immunity in the Host Defense Against Intestinal Bacterial Pathogens

Eradication of infectious disease is our global health challenge. After encountering intestinal infection with a bacterial pathogen, the host defense program is initiated by local antigen-presenting cells (APCs) that eliminate invading pathogens by phagocytosis and establish localized inflammation by secreting cytokines and chemokines. These pathogen-experienced APCs migrate to the mesenteric lymph nodes, where host immune responses are precisely orchestrated. Initiation and regulation of this defense program appear to be largely dependent on innate immunity which is antigen non-specific and provides a rapid defense against broader targets. On the other hand, many bacterial enteropathogens have evoked abilities to modify the host defense program to their advantage. Therefore, better understanding of the host-pathogen interactions is essential to establish effective eradication strategies for enteric infectious diseases. In this review, we will discuss the current understanding of innate immune regulation of the host defense mechanisms against intestinal infection by bacterial pathogens.     

D vitamin and immunity

Active vitamin D3 is a key factor in many pathological states. In this review its influence on the immune system will be discussed, especially in the scope of innate and adaptive immunity. D3 has a crucial importance in defense against infections and in development of immunopathological reactions, especially in autoimmunity.     

Vitamin D and the immune system: new perspectives on an old theme

It is almost 30 years since an interaction between vitamin D and the immune system was first documented. Although this was initially proposed as a nonclassic effect of vitamin D associated with granulomatous diseases, our current view is now changed considerably. Recent studies have shown a potential physiologic role for vitamin D in regulating normal innate and adaptive immunity. Future studies now need to focus on the clinical implications of vitamin D–mediated immunity and, in particular, the possible beneficial effects of supplementary vitamin D with respect to infectious and autoimmune diseases.     

Mast cells in allergy and host defense.

Mast cells have been implicated in the pathogenesis of allergic diseases and in inflammatory responses associated with pathological immune and disease-related processes including fibrosis, autoimmune pathology, and neoplasia. Recent findings in animal models of bacterial infection also suggest that mast cells may have a protective role in host defense against pathogens in innate immunity along with the probable role of mast cells in acquired immunity against parasitic infections. Mast cells are strategically located at the host-environment interface and may provide an early defense against an invading pathogen. Mast cells express an array of adhesion and immune receptors that may assist in the recognition of invading pathogens. When activated, these cells then synthesize and release key immunoregulatory cytokines, one consequence of which is to mobilize a rapid and vigorous inflammatory response. However, although it has been demonstrated that mast cells may have a role in innate immunity in defined in vitro and animal models, it remains to be determined whether mast cells are protective in innate immune responses in humans.     

Micronutrients and innate immunity

Micronutrients such as zinc, selenium, iron, copper, beta-carotene, vitamins A, C, and E, and folic acid can influence several components of innate immunity. Select micronutrients play an important role in alteration of oxidant-mediated tissue injury, and phagocytic cells produce reactive oxidants as part of the defense against infectious agents. Thus, adequate micronutrients are required to prevent damage of cells participating in innate immunity. Deficiencies in zinc and vitamins A and D may reduce natural killer cell function, whereas supplemental zinc or vitamin C may enhance their activity. The specific effects of micronutrients on neutrophil functions are not clear. Select micronutrients may play a role in innate immunity associated with some disease processes. Future studies should focus on issues such as age-related micronutrient status and innate immunity, alterations of micronutrients in disease states and their effect on innate immunity, and the mechanisms by which micronutrients alter innate immunity.     

巨噬细胞在抗结核感染中的作用

巨噬细胞在结核病发病过程及机体抗结核免疫过程中扮演重要的角色。巨噬细胞是机体天然免疫的重要组成细胞,同时又是一类主要的抗原提呈细胞。在天然免疫和获得性免疫中都起着关键的作用。结核病是由结核分枝杆菌引起的严重危害人类健康的主要传染病,结核分枝杆菌可以通过多种途径来干扰机体巨噬细胞的免疫应答。本篇综述的目的在于讨论宿主被结核分枝杆菌入侵后,巨噬细胞在各种抗结核感染的免疫应答中的作用机制。     

Vitamin D, respiratory infections, and asthma

Over the past decade, interest has grown in the role of vitamin D in many nonskeletal medical conditions, including respiratory infection. Emerging evidence indicates that vitamin D-mediated innate immunity, particularly through enhanced expression of the human cathelicidin antimicrobial peptide (hCAP-18), is important in host defenses against respiratory tract pathogens. Observational studies suggest that vitamin D deficiency increases risk of respiratory infections. This increased risk may contribute to incident wheezing illness in children and adults and cause asthma exacerbations. Although unproven, the increased risk of specific respiratory infections in susceptible hosts may contribute to some cases of incident asthma. Vitamin D also modulates regulatory T-cell function and interleukin-10 production, which may increase the therapeutic response to glucocorticoids in steroid-resistant asthma. Future laboratory, epidemiologic, and randomized interventional studies are needed to better understand vitamin D’s effects on respiratory infection and asthma.     

Vitamin D recommendations: beyond deficiency

Vitamin D plays an important role in regular bone growth and in adequate function of the innate immune system, including barrier functions of mucous membranes. A sufficient supply during pregnancy and lactation protects the child from infectious diseases. Clinical symptoms of severe vitamin D deficiency (rickets) are well known and can be easily detected. Signs and symptoms beyond deficiency, however, remain to be elucidated. Based on clinical and observational data, the plasma level of 25(OH)D may serve as a 'marker' to detect or define a subclinical deficiency. Levels below 50 nmol/l might be insufficient to maintain the non-bone-related activities of vitamin D. Finally, it has to be considered that all of the nonbone activities of vitamin D are in concert with vitamin A (9-cis retinoic acid). Studies combining both vitamins in sufficient amounts (cod liver oil) demonstrated a beneficial effect on the prevention of respiratory tract infections. Consequently, it should be strongly recommended to increase the intake of vitamin D and to ensure a daily intake of vitamin A as counseled.     

Vitamin D deficiency and hepatitis viruses-associated liver diseases:a literature review

The secosteroid hormone vitamin D has, in addition to its effects in bone metabolism also functions in the modulation of immune responses against infectious agents and in inhibiting tumorigenesis. Thus, deficiency of vitamin D is associated with several malignancies, but also with a plethora of infectious diseases. Among other communicable diseases, vitamin D deficiency is involved in the pathogenesis of chronic liver diseases caused by hepatitis B and C viruses(HBV, HCV) and high prevalence of vitamin D deficiency with serum levels below 20 mg/mL in patients with HBV and HCV infection are found worldwide. Several studies have assessed the effects of vitamin D supplementation on the sustained virological response(SVR) to interferon(IFN) plus ribavirin(RBV) therapy in HBV and HCV infection. In these studies, inconsistent results were reported. This review addresses general aspects of vitamin D deficiency and, in particular, the significance of vitamin D hypovitaminosis in the outcome of HBVand HCV-related chronic liver diseases. Furthermore,current literature was reviewed in order to understand the effects of vitamin D supplementation in combination with IFN-based therapy on the virological response in HBV and HCV infected patients.