A method for measuring mouse respiratory allergic reaction to low-dose chemical exposure to allergens: An environmental chemical of uncertain allergenicity,a typical contact allergen and a non-sensitizing irritant

Our aim was to improve a method for detecting respiratory hypersensitivity by testing three confirmed respiratory allergens (trimellitic anhydride [TMA], phthalic anhydride [PA] and toluene diisocyanate [TDI]), an environmental chemical of uncertain allergenicity (2,4-d-butyl [DB]), a confirmed contact allergen (2,4-dinitrochlorobenzene [DNCB]) and a standard irritant (sodium dodecyl sulfate [SDS]). BALB/c mice were topically sensitized (nine times in 3 weeks) with these chemicals, then challenged via the trachea. One day post-challenge, samples were taken from the mice to assay for total immunoglobulin (IgE and IgG₁) levels in serum and bronchoalveolar lavage fluid (BALF); differential cell counts and cytokine/chemokine levels in BALF; lymphocyte counts and surface antigen expression on B-cells within lung-associated lymph nodes (LNs); ex situ cytokine production by cells from these LNs; and gene expression in BALF (CCR3) and LNs (CCR4, STAT6 and GATA-3). The three confirmed respiratory allergens and DB induced immune response characteristic of immediate-type respiratory reactions, as evidenced by increased total IgE and IgG₁ levels; influx of eosinophils, neutrophils, chemokines and cytokines in BALF; increased surface antigen expression on B-cells in LNs; increased Th2 cytokine production in LNs; and increased respiratory allergy-related gene expression in both BALF and LNs. In contrast, DNCB and SDS treatments yielded, at most, insignificant increases in all respiratory allergic parameters. Thus, the protocol was equally suitable for use with an environmental chemical of unknown allergenicity and for typical respiratory allergens. Since the protocol differentiated respiratory allergens from contact allergens and irritants, it may be useful for detecting respiratory allergy related to environmental chemicals.     

Comparative study of anticoagulant and procoagulant properties of 28 snake venoms from families Elapidae, Viperidae, and purified Russell’s viper venom-factor X activator (RVV-X)

Snake venoms consist of numerous molecules with diverse biological functions used for capturing prey. Each component of venom has a specific target, and alters the biological function of its target. Once these molecules are identified, characterized, and cloned; they could have medical applications. The activated clotting time (ACT) and clot rate were used for screening procoagulant and anticoagulant properties of 28 snake venoms. Crude venoms from Daboia russellii siamensis, Bothrops asper, Bothrops moojeni, and one Crotalus oreganus helleri from Wrightwood, CA, had procoagulant activity. These venoms induced a significant shortening of the ACT and showed a significant increase in the clot rate when compared to the negative control. Factor X activator activity was also measured in 28 venoms, and D. r. siamensis venom was 5-6 times higher than those of B. asper, B. moojeni, and C. o. helleri from Wrightwood County. Russell’s viper venom-factor X activator (RVV-X) was purified from D. r. siamensis venom, and then procoagulant activity was evaluated by the ACT and clot rate. Other venoms, Crotalus atrox and two Naja pallida, had anticoagulant activity. A significant increase in the ACT and a significant decrease in the clot rate were observed after the addition of these venoms; therefore, the venoms were considered to have anticoagulant activity. Venoms from the same species did not always have the same ACT and clot rate profiles, but the profiles were an excellent way to identify procoagulant and anticoagulant activities in snake venoms.     

Targeting podocyte-associated diseases

Injury to the podocytes is the initiating cause of many renal diseases, leading to proteinuria with possible progression to end-stage renal disease. Podocytes are highly specialized cells, with an important role in maintaining the glomerular filtration barrier and producing growth factors for both mesangial cells and endothelial cells. With their foot processes they cover the glomerular basement membrane, and form slit diaphragms with neighboring podocytes.Human podocytopathies include focal and segmental glomerulosclerosis, minimal change disease, membranous nephropathy, collapsing glomerulopathy and diabetic nephropathy. Research in the last two decades has demonstrated great progress in understanding the molecular mechanisms leading to podocytopathies. These include single gene defects in slit diaphragm proteins, but also discovery of apoptotic, enzymatic and other pathways involved in podocyte injury. With this progress, a great number of animal models is now available to study either specific podocytopathies, e.g. in mouse models with single gene mutations, or more general podocyte injury patterns, such as the lipopolysaccharide or protamine sulfate model of foot process effacement.In this review, the morphology of the glomerulus will be discussed, with a focus on the podocyte, its interactions with surrounding cells, and the highly differentiated slit diaphragm separating the apical from the basal membrane. We also provide an overview of human podocytopathies and animal models to study these diseases. In the last part we discuss targeted therapies addressing pathways and proteins affected in podocyte injury.     

CpG ODN对小鼠哮喘模型气道炎症及信号转导子和转录激活子6（STAT6）表达的影响

目的：研究寡核甘酸免疫刺激序列（CpG oligonucleotides,CpG ODN）对急性支气管哮喘小鼠气道炎症及信号转导子和转录激活子6（STAT6）表达的调控作用。方法：将32只雄性BALB／c小鼠随机分为对照组、哮喘组、地塞米松干预组和CpG ODN干预组,建立急性哮喘气道炎症模型。对支气管肺泡灌洗液（BALF）进行细胞总数、嗜酸粒细胞（EOS）分类计数;取左叶肺组织切片做HE染色观察气道和肺组织炎症改变;用免疫组织化学法检测气道上皮组织中STAT6表达。结果：哮喘组小鼠BALF中细胞总数、EOS绝对值显著高于对照组（P〈0．05）,地塞米松组和CpG ODN组上述炎症细胞计数比哮喘组明显减少（P〈0．05）。HE染色示地塞米松组和CpG ODN组小鼠肺组织炎症程度较哮喘组减轻。STAT6在气道上皮细胞表达,哮喘组气道上皮细胞中STAT6表达较对照组增强,地塞米松组和CpG ODN组STAT6表达与哮喘组比较有明显减少（P〈0．05）,较对照组增加。支气管上皮细胞STAT6蛋白表达与BALF中的EOS绝对值呈显著正相关（r=0．748）,而地塞米松组和CpG ODN组之间的作用无统计学差异（P〉0．05）。结论：应用地塞米松和CpG ODN均可在一定程度上减轻哮喘小鼠的气道炎症,CpG ODN可能通过下调肺组织中STAT6蛋白的过度表达,从而抑制依赖于STAT6/IL-4通路的急性气道炎症,减轻哮喘的症状。     

Acute pulmonary embolism in childhood

Pulmonary embolism is an uncommon, but potentially fatal disease in children. Most children with pulmonary embolism have underlying clinical conditions, of which the presence of a central venous catheter is the most frequent. The clinical presentation is often subtle, or masked by the underlying clinical condition. Diagnostic as well as therapeutic strategies for pulmonary embolism in children are mostly extrapolated from studies in adults. Pulmonary angiography is still the gold standard in diagnosing pulmonary embolism, but several other radiographic tests can be used to diagnose pulmonary embolism, including ventilation-perfusion lung scanning, helical computed tomography, magnetic resonance imaging and echocardiography. The choice of treatment depends on the clinical presentation of the patient. Anticoagulation is the mainstay of therapy for children with pulmonary embolism. However, thrombolytic therapy can be considered for patients with hemodynamic instability. The outcome of pediatric pulmonary embolism is uncertain and needs to be studied.     

Thrombolytic therapy in children

Thrombolysis is increasingly considered a treatment option in newborns and children with arterial and venous thromboembolic events, or occluded central venous lines. However, no uniform recommendations are available with regard to indications, drug of choice, route of administration, and dosing regimen. Thus, several protocols are used for the different thrombolytic agents, leading to differing outcome with respect to the effectiveness of therapy and bleeding complications. This article will summarize the available information on the use of thrombolytic agents in newborns and children, focussing on the potential indications, efficacy and safety profiles, and evidence supporting dosing schedules.