Investigation of the negative chronotropic action of SK&F 86466 in the pithed normotensive rat

SK&F 86466, 6-chloro-3-methyl-2,3,4,5-tetrahydro-1-H-3-benzazepine, is a potent and selective antagonist of the α₂-adrenoceptor in vitro. This compound produced a small pressor response accompanied by a marked bradycardia when administered i.v. to the pithed normotensive rat. The pressor response was not affected by reserpine treatment, pretreatment with α- or β-adrenoceptor antagonists, atropine, or hexamethonium. The bradycardia was markedly reduced by bilateral vagotomy and pretreatment with atropine and attenuated by hexamethonium. The negative chronotropic action of SK&F 86466 was abolished by a combination of vagotomy and atropine. Mediation of the bradycardia by a baroreceptor reflex was ruled out by the observations that a lack of change in heart rate was associated with the vasopressor response to phenylephrine in the pithed rat pretreated with propranolol. It is concluded that the negative chronotropic action of SK&F 86466 in the pithed rat is mediated indirectly by activation of the cholinergic innervation of the heart.     

Inhaled allergen-driven CD1c up-regulation and enhanced antigen uptake by activated human respiratory-tract dendritic cells in atopic asthma

Background Dendritic cells (DC) mediate inflammation in rodent models of allergic airway disease, but the role played by human respiratory‐tract DC (hRTDC) in atopic asthma remains poorly defined. Recent data suggest that CD1 antigen presentation by hRTDC may contribute to asthma pathogenesis. Objective To investigate the influence of hRTDC on the balance between atopy and allergic asthma in human subjects and to determine whether CD1 expression by hRTDC is modulated during asthmatic inflammation. Methods Sputum cells were induced from steroid‐naïve, allergen‐challenged and allergen‐naïve subjects (atopic asthmatics, atopic non‐asthmatics and non‐atopic controls). hRTDC were identified using monoclonal antibody labelling and analysis by flow cytometry. Results hRTDC stained HLA‐DR⁺ (negative for markers of other cell lineages) were predominantly myeloid and comprised ∼0.5% of viable sputum cells. Sputum cells were potent stimulators of allogeneic CD4⁺ naïve T cells and enrichment/depletion experiments correlated stimulatory potency with DC numbers. Sputum contained cells that exhibited typical dendritic morphology when analysed by electron microscopy. Myeloid hRTDC were endocytically active, but uptake of FITC‐dextran was enhanced in cells from asthmatics (P<0.001). Despite their increased endocytic capacity, asthmatic myeloid hRTDC appeared mature and expressed increased levels of maturation markers (P<0.05–P<0.001), CD1c, CD1d and langerin (P<0.05). CD1c expression by asthmatic myeloid hRTDC was enhanced upon in vivo allergen challenge (three to ninefold within 24 h; P<0.05). CD11c⁻CD123^high hRTDC were only detected in asthmatic sputum and were increased in number following allergen challenge. Conclusion Despite limited cell numbers, it proved possible to analyse human RTDC in induced sputum, providing evidence that increased antigen uptake and enhanced CD1 presentation by activated hRTDC may contribute to allergic airway disease. CD1 presentation by hRTDC in atopic asthma may therefore constitute a novel target for future intervention strategies.     

In vivo anti-melanoma activities of the Melan-A/MART-1101–115 T CD4+ cell peptide

Malignant melanoma causes significant health problems. The identification of tumour-associated antigens has led to novel approaches to increase T cell mediated anti-tumour immune response. Melan-A/MART-1 has been use as target antigen for several T cell based immunotherapeutic treatments. More recently, the critical role of CD4+ T cells in inducing and maintaining anti-tumour immunity has been increasingly recognized. In order to optimize tumour immunotherapy, greater efforts have been concentrated on the identification of tumour antigens presented by MHC class II molecules to CD4+ T cells. In a publication, Tiwari et al. (2004) [1] have identified by a computational approach the 15-mer amino-acid sequence 101–115 (PPAYEKLSAEQSPPP) of the Melan-A/MART-1 as a good target for a vigorous and safe immunotherapy. Therefore, we have investigated the in vivo anti-tumour activity of this peptide in a murine melanoma model. For the prophylactic treatment, 20 μg or 50 μg peptide was subcutaneously injected in mice once a week during 3 weeks before tumour induction. Treatment with 50 μg peptide significantly affected tumour development. Thus, our preliminary data demonstrate potential in vivo prophylactic activity of the 101–115 peptide-based vaccine to control melanoma growth.     

维生素D的骨外作用

越来越多的研究表明,维生素D除具有经典的调节钙磷平衡和维持骨骼健康的作用外,还具有其他更为广泛的骨外生物学效应,如调节免疫、抗肿瘤、保护中枢神经系统和防治代谢综合征等作用.本文就相关方面的研究进展进行综述.     

前列腺素E1对大鼠肝移植肾功能的保护作用

目的探讨术中应用前列腺素E1（prostaglandin E1，PGE1）对大鼠肝移植肾功能的保护作用。方法大鼠原位肝移植术中经颈内静脉灌注PGE1为治疗组，生理盐水和空白为对照组，观察术后1周存活率、1h的尿量，测定血浆肌酐、尿素氮和肾组织中丙二醛（malondjaldehyde，MDA）、谷胱甘肽（glutathione，GSH）含量，肾组织病理检查。结果PGE1治疗组术后1h尿量较对照组明显增加，肌酐和尿素氮水平均较对照组降低，PGE1治疗组肾组织中GSH含量显著高于两对照组，MDA含量低于两对照组。病理检查PGE1治疗组肾脏组织形态学损伤明显减轻。结论术中应用PGE1能显著改善大鼠肝移植后的肾功能，其机制可能与对抗氧自由基损伤作用有关。     

胰岛素样生长因子1对新生大鼠缺氧缺血性脑损伤保护机制的研究

目的　建立单侧缺氧缺血性脑损伤 (HIBD)动物模型 ,研究胰岛素样生长因子 1(IGF 1)对HIBD的影响和可能机制。　方法　选择健康 7日龄Wistar大鼠 12 0只 ,建立HIBD模型 ,随机分成假手术组、HIBD组、HIBD后 0 .2mg/kg人基因重组IGF 1干预组 (RH IGF 1组 )、0 .0 6 6mg/kg人基因重组IGF 1干预组 (SRH IGF 1组 )及盐水对照组 (对照组 )。各组按观察时段进一步分为 2 4、4 8、72h组 ,每组 8只。各组于规定时刻观测脑形态学改变、谷氨酸 (Glu)含量、凋亡细胞计数、Bcl 2蛋白表达。　结果　 (1)HIBD 4 8h组Glu(116 2 .2± 10 8.1)mg/kg ,较假手术组(75 0 .9± 5 3.4 )mg/kg明显升高 (P <0 .0 5 ) ;HIBD组凋亡细胞计数 [2 4h :(7.6± 1.9) % ,4 8h(12 .6±1.2 ) % ,72h :(13.8± 0 .9) % ],较假手术组 [2 4h(2 .0± 0 .2 ) % ,4 8h(2 .0± 0 .3) % ,72h(2 .0±0 .2 ) % ]明显增加 (P均 <0 .0 5 )。 (2 )与对照组相比 ,RH IGF 1组脑组织病变减轻 ;干预 4 8h组Glu[SRH IGF 1组 (781.4± 5 4 .2 )mg/kg ,RH IGF 1组 (74 0 .5± 4 6 .6 )mg/kg],较对照组 (112 6 .6± 4 8.0 )mg/kg明显降低 (P均 <0 .0 5 ) ;RH IGF 1组凋亡细胞计数 [2 4h :(3.6± 0 .9) % ,4 8h(8.2± 2 .2 ) % ,72h(9.4± 1.4 ) % ],较对     

Sauerstoff tragende L?sungen verbessern die Gewebeoxygenation im quergestreiften Hautmuskel nach kritischer Isch?miezeit

Zusammenfassung Fragestellung. Ziel der vorliegenden Untersuchung war, die Effekte der Sauerstoff tragenden freien H?moglobinl?sung (Diaspirin-crosslinked-H?moglobin, DCLHb) auf die kapillare Perfusion sowie die Oxygenation im quergestreiften Hautmuskelgewebe nach kritischer Isch?miezeit und nachfolgender Reperfusion zu analysieren. Material und Methode. Die kapillare Gewebeperfusion wurde anhand der funktionellen Kapillardichte im Hautmuskel des syrischen Goldhamsters quantitativ vor der Induktion einer 4-stündigen Isch?mie sowie nach 0,5 h, 2 h und 24 h Reperfusion mittels intravitaler Fluoreszenzmikroskopie erfasst (n=8 pro Versuchsgruppe). In separaten Tieren wurde nach demselben Versuchsansatz mit der Mehrdrahtoberfl?chenelektrode (MDO, Eschweiler, Kiel) die Gewebeoxygenation gemessen (n=8 pro Versuchsgruppe). Die Tiere der Testgruppe (n=8) erhielten 15 min vor der Reperfusion eine Kurzinfusion von 5 ml/kg KG DCLHb (Diaspirin-crosslinked-H?moglobin, 10 g/dl, Baxter, IL, USA). Die Kontrolltiere (n=8) erhielten ?quivalente Dosen einer isotonen Kochsalzl?sung (Braun, Melsungen). Ergebnisse. Die funktionelle Kapillardichte als Ma? für die L?nge von erythrozytenperfundierten Kapillaren pro Beobachtungsfeld war bei den Kontrolltieren in der Reperfusionsphase dramatisch vermindert, w?hrend bei den mit DCLHb behandelten Tieren signifikant h?here Werte nachweisbar waren (p<0,05). Diese Beobachtung spiegelte sich in einer vollst?ndigen Erholung des Gewebe-pO₂ bei den Behandlungstieren wider, was in Kontrolltieren nicht erreicht wurde. Schlussfolgerungen. Die Ergebnisse dieser Studie zeigen, dass die Sauerstoff tragende L?sung DCLHb nach kritischer Isch?mie und Reperfusion die nutritive Perfusion und Gewebeoxygenation gegenüber kristalloiden L?sungen verbessert. Die Anwendung derartiger L?sungen scheint unter den klinischen Bedingungen einer kritischen Isch?mie daher als viel versprechender adjuvanter therapeutischer Ansatz. Electronic Publication     

HIV.1的转录因子NF-kB及其抑制剂的研究进展

在病毒复制循环过程中,HIV-1的转录是其中的关键步骤,可作为HIV-1治疗的新靶点.在此过程涉及的所有因子中,细胞核因子κB(nuclear factor kappa B,NF-κB)是HIV-1转录过程中重要的诱导剂.NF-κB通过与HIV-1的长末端重复序列(long terminal repeat,LTR)增强子区的连接来激活HIV-1的转录.许多化合物通过抑制NF-κB的活性来抑制HIV-1的转录.本文综述了NF-κB对HIV-1转录过程的调节及当前NF-κB抑制剂的研究进展.     

Sick day management using blood 3-hydroxybutyrate (3-OHB) compared with urine ketone monitoring reduces hospital visits in young people with T1DM: a randomized clinical trial.

AIMS: Diabetic ketoacidosis (DKA), a life-threatening acute complication of Type 1 diabetes, may be preventable with frequent monitoring of glycaemia and ketosis along with timely supplemental insulin. This prospective, two-centre study assessed sick day management using blood 3-hydroxybutyrate (3-OHB) monitoring compared with traditional urine ketone testing, aimed at averting emergency assessment and hospitalization. METHODS: One hundred and twenty-three children, adolescents and young adults, aged 3-22 years, and their families received sick day education. Participants were randomized to receive either a blood glucose monitor that also measures blood 3-OHB (blood ketone group, n = 62) or a monitor plus urine ketone strips (urine ketone group, n = 61). All were encouraged to check glucose levels > or = 3 times daily and to check ketones during acute illness or stress, when glucose levels were consistently elevated (> or = 13.9 mmol/l on two consecutive readings), or when symptoms of DKA were present. Frequency of sick days, hyperglycaemia, ketosis, and hospitalization/emergency assessment were ascertained prospectively for 6 months. RESULTS: There were 578 sick days during 21,548 days of follow-up. Participants in the blood ketone group checked ketones significantly more during sick days (276 of 304 episodes, 90.8%) than participants in the urine ketone group (168 of 274 episodes, 61.3%) (P < 0.001). The incidence of hospitalization/emergency assessment was significantly lower in the blood ketone group (38/100 patient-years) compared with the urine ketone group (75/100 patient-years) (P = 0.05). CONCLUSIONS: Blood ketone monitoring during sick days appears acceptable to and preferred by young people with Type 1 diabetes. Routine implementation of blood 3-OHB monitoring for the management of sick days and impending DKA can potentially reduce hospitalization/emergency assessment compared with urine ketone testing and offers potential cost savings.     

Homocysteinylation of low-density lipoproteins (LDL) from subjects with Type 1 diabetes: effect on oxidative damage of human endothelial cells.

BACKGROUND: Homocysteine (Hcy) is an independent risk factor for cardiovascular disease (CVD). Individuals with Type 1 and Type 2 diabetes are more susceptible to the effects of homocysteine than non-diabetic subjects. The interaction between homocysteine-thiolactone (Hcy-thiolactone), a reactive product of Hcy, and low-density lipoproteins (LDL) induces the formation of homocystamide-LDL adducts (Hcy-LDL) and it has been suggested that homocysteinylation could increase atherogenicity of lipoproteins. AIM: The aim of the study was to compare the effect of in vitro homocysteinylation of LDL isolated from healthy control subjects (C-LDL) and from Type 1 diabetic patients (DM-LDL) and to investigate the effect of homocysteinylated LDL (Hcy-C-LDL and Hcy-DM-LDL) on peroxynitrite production of endothelial cells. METHODS: The in vitro homocysteinylation of LDL isolated from control (n = 12) and DM subjects (n = 12) was carried out by incubating lipoproteins with Hcy-thiolactone. The reaction was verified by quantifying the increase in sulphydryl groups (-SH groups) in Hcy-LDL with respect to control LDL. Control and homocysteinylated LDL were incubated with human aortic endothelial cells (HAEC) in culture. Peroxynitrite production in cells treated in different experimental conditions was assayed by a fluorimetric method. RESULTS: The increase in -SH groups after incubation with homocysteine was greater in LDL from diabetic subjects compared with LDL from control subjects (P < 0.001). In addition, peroxynitrite production from HAEC incubated with Hcy-LDL from diabetic patients was greater than after incubation with Hcy-LDL from control subjects and untreated LDL from diabetic patients (P < 0.001). CONCLUSIONS: These results show that LDL from diabetic patients is more susceptible to in vitro homocysteinylation than LDL from non-diabetic individuals and demonstrate that the compositional changes in Hcy-LDL from diabetic subjects have cytotoxic effects on human endothelial cells.