Differential chemokine response of murine macrophages stimulated with cytokines and infected with Listeria monocytogenes

During inflammatory processes the infected macrophage is a rich source of chemokines which induce infiltration of leukocytes to the site of infection. We investigated the regulation of chemokine production by murine macrophages in response to infection with the intracellular bacterial pathogen, Listeria monocytogenes. As a source of quiescent macrophages, murine bone marrow-derived macrophages (BMM) cultured under serum-free conditions were used. With RT-PCR, we detected induction of RNA message for the chemokines macrophage inflammatory protein (MIP)-2, KC, MIP-1alpha, MIP-1beta, IFN-gamma-inducible protein- 10 and RANTES in L. monocytogenes-infected macrophages. Accordingly, ELISA-detectable MIP-1alpha, MIP-2 and KC protein was induced by infection with L. monocytogenes. In contrast, L. monocytogenes infection of BMM alone failed to induce considerable expression of monocyte chemoattractant protein (MCP)-1 at the mRNA or protein level, but co-treatment with IFN-gamma was necessary. Release of infection- triggered MIP-2, MIP-1alpha and KC was negatively regulated by IFN- gamma. Similarly, IL-4 stimulated MCP-1 release by infected macrophages but reduced production of MIP-1alpha, MIP-2 and KC. IL-10 turned out to be a general deactivator in terms of macrophage chemokine production. IL-13 had no effect on MIP-1alpha, MIP-2 and KC production by infected BMM, but slightly reduced MCP-1 release. By using IFN-gamma and IL-4 gene deletion mutant mice, in vivo regulation of these chemokines by IL- 4 and IFN-gamma in listeriosis was studied. In summary, our results show that chemokines are produced by macrophages infected with L. monocytogenes, and that chemokine release is differentially regulated by the macrophage modulators IFN-gamma, IL-4, IL-10 and IL-13.      

Diagnosing Dysautonomia After Acute Traumatic Brain Injury: Evidence for Overresponsiveness to Afferent Stimuli

Baguley IJ, Nott MT, Slewa-Younan S, Heriseanu RE, Perkes IE. Diagnosing dysautonomia after acute traumatic brain injury: evidence for overresponsiveness to afferent stimuli.

Objective

To differentiate between traumatic brain injury (TBI) subjects with normal and elevated autonomic activity by quantifying cardiac responsivity to nociceptive stimuli and to determine the utility of heart rate variability (HRV) and event-related heart rate changes in diagnosing dysautonomia.

Design

Prospective cohort study.

Setting

Intensive care unit in a tertiary metropolitan trauma center.

Participants

Adults (N=27) with TBI recruited from 79 consecutive TBI admissions comprising 16 autonomically aroused and 11 control subjects matched by age, sex, and injury severity.

Interventions

None.

Main Outcome Measures

Immediate: pattern of autonomic changes indexed by HRV and event-related heart rate after nociceptive stimuli. Six months: length of stay, Glasgow Coma Scale, and Disability Rating Scale.

Results

Heart rate changes (for both HRV and event-related heart rate) were associated with the diagnostic group and 6-month outcome when evaluated pre- and poststimulus but not when evaluated at rest. When assessed on day 7 postinjury, the comparison of HRV and heart rate parameters suggested an overresponsivity to nociceptive stimuli in dysautonomic subjects. These subjects showed a 2-fold increase in mean heart rate relative to subjects with sympathetic arousal of short duration (16% vs 8%), and a 6-fold increase over nonaroused control subjects. Data suggest that post-TBI sympathetic arousal is a spectrum disorder comprising, at one end, a short-duration syndrome and, at the other end, a dramatic, severe sympathetic and motor overactivity syndrome that continued for many months postinjury and associated with a significantly worse 6-month outcome. These findings suggest that it is not the presence of reactivity per se but rather the failure of processes to control for overreactivity that contributes to dysautonomic storming.

Conclusions

This study provides empirical evidence that dysautonomic subjects show overresponsiveness to afferent stimuli. Findings from this study suggest an evidence-driven revision of diagnostic criteria and a simple clinical algorithm for the improved identification of cases.     

Effects of massage on limb and skin blood flow after quadriceps exercise

PURPOSE: At present, there is little scientific evidence that postexercise manual massage has any effect on the factors associated with the recovery process. The purpose of this study was to compare the effects of massage against a resting control condition upon femoral artery blood flow (FABF), skin blood flow (SKBF), skin (SKT), and muscle (MT) temperature after dynamic quadriceps exercise. METHODS: Thirteen male volunteers participated in 3 x 2-min bouts of concentric quadriceps exercise followed by 2 x 6-min bouts of deep effleurage and pétrissage massage or a control (rest) period of similar duration in a counterbalanced fashion. Measures of FABF, SKBF, SKT, MT, blood lactate concentration (BLa), heart rate (HR), and blood pressure (BP) were taken at baseline, immediately after exercise, as well as at the midpoint and end of the massage/rest periods. Data were analyzed by two-way ANOVA. RESULTS: Significant main effects were found for all variables over time due to effects of exercise. Massage to the quadriceps did not significantly elevate FABF (end-massage 760 +/- 256 vs end-control 733 +/- 161 mL x min(-1)), MT, BL, HR, and BP over control values (P < 0.05). SKBF (end-massage 150 +/- 49 vs end control 6 +/- 4 au) SKT (end-massage 32.2 +/- 0.9 vs end-control 31.1 +/- 1.3degreesC) were elevated after the application of massage compared with the control trial (P < 0.05). CONCLUSION: From these data it is proposed that without an increase in arterial blood flow, any increase in SKBF is potentially diverting flow away from recovering muscle. Such a response would question the efficacy of massage as an aid to recovery in postexercise settings.     

Effects of IL-13 on murine listeriosis

Acquired resistance against Listeria monocytogenes is a typical T helper (Th) 1 dominated immune response, whereas Th2 cytokines are thought to worsen listeriosis. We investigated effects of recombinant IL-13 (rIL-13) on the host response to L. monocytogenes in mice. Although IL-13 has been described as a Th2 cytokine with deactivating anti-inflammatory activities, it was found to enhance antilisterial resistance. In vitro, rIL-13 increased IL-12 p40 and p70 production by bone marrow macrophages infected with L. monocytogenes. In vivo, numbers of viable bacteria in spleens and livers were decreased after treatment of mice with rIL-13. In addition, granuloma formation was impaired and NK cell activity of spleen cells was enhanced. At the onset of infection, frequencies of IL-12-producing cells were increased and numbers of IL-4- and IFN-gamma-secreting cells were diminished in rIL-13-treated mice as compared to controls. In contrast, on day 6 after infection, IL-12, IL-4 and IFN-gamma levels in rIL-13-treated animals were equal to or even higher than those in controls. Although direct activation of host macrophages by IL-13 is possible, we consider it more likely that IL-13 acted indirectly through stimulation of IL-12 production and inhibition of IL-4 release early after infection. In contrast, our data argue against an apparent role of IFN-gamma in IL-13- induced antilisterial resistance.      

BEMF对OVX-OP大鼠骨细胞凋亡的影响

目的 观察BEMF对 OVX-OP大鼠骨细胞凋亡的影响,探讨其治疗 OVX-OP的作用机制.方法 6月龄雌性未孕Wistar大鼠40只,按体质量随机分为模型组(OVX)、假手术组(Sham)、仿生电磁场治疗组(EM)、雌激素治疗组(E).OVX、EM、E组行双侧卵巢切除术,Sham组行假手术.术后第9周开始治疗:E组行苯甲酸雌二醇肌肉注射,0.5mg/kg,1次/2周.EM组大鼠暴露于仿生脉冲电磁场治疗,1h·次-1·d-1,OVX、Sham组不予任何处理,作为对照组.治疗10周后应用原位凋亡法计数腰椎松质骨骨细胞的凋亡指数、透射电镜观察骨细胞凋亡情况、免疫组化法观察骨细胞Fas、bax、bcl-2表达情况.结果 与OVX组相比, EM组骨细胞凋亡指数显著下降,差异有统计学意义(P＜0.01),透射电镜观察显示EM组骨细胞活性增强,无明显凋亡征象,而OVX组骨细胞呈退行改变,可见异染色体凝聚、边集等典型细胞凋亡征象.EM组Fas阳性骨细胞数较OVX组显著性减少, bax阳性骨细胞数与bcl-2阳性骨细胞数比值显著减少,差异有统计学意义(P＜0.01).结论 BEMF对 OVX-OP骨细胞凋亡的抑制作用,可能是其治疗 OVX-OP的机制之一.     

一项左旋多巴乙酯对伴有运动波动帕金森病患者疗效的随机对照试验

背景：运动波动是长期接受左旋多巴治疗的帕金森病（PD）患者的一个常见并发症。胃排空减慢及胃肠道左旋多巴溶解性差会延迟给药后疗效的产生。左旋多巴乙酯作为左旋多巴的一种乙酯前体药物具有更好的胃溶性，可迅速进入小肠并快速水解成左旋多巴，缩短了左旋多巴达到最大浓度的时间。目的：确定左旋多巴乙酯对伴有运动波动PD患者的疗效、安全性和耐受性。设计：一项双盲、随机、比较的临床试验。机构：美国和加拿大的44个地区。患者：每日给予左旋多巴后至少需潜伏90min才能达到“开”期（TTON）的327例PD患者。干预：使用左旋多巴乙酯-卡比多巴或左旋多巴-卡比多巴治疗18周。主要观察指标：利用家庭日记测定每日总的TTON相对于基线的改变。结果：左旋多巴乙酯-卡比多巴治疗组平均每日总的TTON减少0．58h，而左旋多巴-卡比多巴治疗组减少了0．79h（P=0．24）。两治疗组在减少治疗无效方面无显著性差异（-6．82％vs-4．69％，P=0．20）。左旋多巴乙酯-卡比多巴（-0．85h）和左旋多巴-卡比多巴治疗组（-0．87h）每日总的“关”期都得到改善且未增加令人棘手的运动障碍。结论：从药物动力学理论上讲，左旋多巴乙酯尽管有优点，但与左旋多巴相比并未能改善TTON、治疗无效和“关”的时间。     

Identification of signaling motifs within human Fc gamma RIIa and Fc gamma RIIb isoforms

To assess the functional capacity of the heterogeneous Fc gamma RII (CD32) family and to identify critical regions for functioning, we generated a panel of B-cell transfectants. The Fc gamma R-negative B- cell line IIA1.6 was transfected with wild-type or mutant human Fc gamma RIIa and IIb molecules. Solely Fc gamma RIIa-expressing IIA1.6 cells were capable of phagocytosing opsonized Staphylococcus aureus bacteria, and cross-linking of Fc gamma RIIa triggered a rapid induction of tyrosine phosphorylation after 20 seconds. Analysis of Fc gamma RIIa mutants identified the immunoreceptor tyrosine-based activation motif (ITAM; previously described as ARH-1 motif) within the IIa cytoplasmic tail to be critical for B-cell activation. In contrast, Fc gamma RIIb isoforms triggered tyrosine phosphorylation on cross- linking with much slower kinetics (> 3 minutes) than Fc gamma RIIa. Furthermore, solely Fc gamma RIIb molecules proved capable of downregulating [Ca2+]i and interleukin-2 production on co-cross-linking with sIgG in IIA1.6. The Fc gamma RIIb-mediated functions were absent in Fc gamma RIIb mutants in which the tyrosine or leucine within the YSLL motif in a conserved 13-aa region (now known as immunoreceptor tyrosine-based inhibitor motif [ITIM]) were changed into phenylalanines. In conclusion, these data show the presence of functionally critical motifs within Fc gamma RII cytoplasmic tails. Fc gamma RIIa contains an ITAM involved in B-cell activatory functions, whereas the downregulatory activity of Fc gamma RIIb isoforms is linked to an ITIM.