Murine dendritic cells modified with CXCL10 gene and tumour cell lysate mediate potent antitumour immune responses in mice

The aim of our present study was to estimate the effect of a therapeutic vaccine against tumour based on dendritic cells (DC) vaccine modified with tumour cell lysate and chemokine CXCL10 gene. In this study, mouse bone marrow DC were pulsed with tumour cell (RM-1) lysate and then transfected with a plasmid vector expressing CXCL10 cDNA by DOTAP liposome. The protective and therapeutic effects of the DC vaccine in RM-1 tumour model were assessed (divided into CXCL10/Lysate-DC, CXCL10/DC, pcDNA/Lysate-DC, Lysate-DC, pcDNA-DC, DC and PBS). The DC transfected with CXCL10 gene were capable of synthesizing and secreting CXCL10 chemokine. The highest CTL activity against RM-1 cells was induced in mice immunized with DC vaccine that was modified with RM-1 lysate and CXCL10 gene (CXCL10/Lysate-DC) when compared with its counterpart in mice. The CXCL10/Lysate-DC immunized mice also exhibited resistance to tumour challenge most effectively. In the RM-1 tumour model, immunization of CXCL10/Lysate-DC inhibited the tumour growth most significantly when compared with other groups and the survival time of the mice treated with CXCL10/Lysate-DC was greatly extended. These findings provide a potential strategy to improve the efficacy of DC-based tumour vaccine.     

An inv(16) in Ph-negative cells of a chronic myelogenous leukemia patient after imatinib treatment

Secondary chromosomal changes are known to develop in Philadelphia chromosome-negative (Ph-) cells of chronic myelogenous leukemia (CML) patients after treatment with imatinib mesylate, an ABL kinase inhibitor. We report here a novel case of a pericentric inversion of chromosome 16 as the sole cytogenetic abnormality in Ph- cells after treatment of Ph+ CML with imatinib.     

Carnosine inhibits pentylenetetrazol-induced seizures by histaminergic mechanisms in histidine decarboxylase knock-out mice

In the present study, we used both histidine decarboxylase-deficient (HDC-KO) mice and wild-type (WT) mice to elucidate the possible role of carnosine in pentylenetetrazol (PTZ)-induced seizures. In the acute PTZ challenge study, PTZ (75 mg/kg) was injected intraperitoneally (i.p.) to induce seizures. Carnosine (200, 500 or 1000 mg/kg, i.p.) significantly decreased seizure stage, and prolonged the latency for myoclonic jerks in WT mice in a dose-dependent manner. The effects of carnosine (500 mg/kg) were time-dependent and reached a peak at 1 h. However, it had no significant effect on HDC-KO mice. Carnosine (500 mg/kg) also significantly elevated the thresholds in WT mice but not HDC-KO mice following intravenous (tail vein) administration of PTZ. We also found that α-fluoromethylhistidine substantially reversed the protective effects of carnosine in WT mice. In addition, carnosine pretreatment reduced the cortical EEG activity induced by PTZ (75 mg/kg, i.p.). These results indicate that carnosine can protect against PTZ-induced seizures and its action is mainly through the carnosine–histidine–histamine metabolic pathway. This suggests that carnosine may be an endogenous anticonvulsant factor in the brain and may be used as a new antiepileptic drug in the future.     

Reciprocal generation of Th1/Th17 and T(reg) cells by B1 and B2 B cells

Regulatory T (T(reg)) cells are indispensable for maintaining peripheral tolerance, whereas T helper (Th)1 and Th17 cells induce inflammation and tissue destruction. Using Foxp3-GFP knock-in mice, we report a novel regulatory role for B cell subsets in influencing the differentiation of T(reg) versus Th1/Th17 cells. Peritoneal B1 cells strongly promoted T cell proliferation and cytokine secretion when presenting nominal or allogeneic antigens, as compared to conventional follicular B (B2) cells. However, peritoneal B1 cells largely failed to convert naive Foxp3(-)CD4(+) T cells into Foxp3(+) T(reg) cells in the presence of TGF-beta and IL-2, in marked contrast to conventional B2 cells, which excelled in T(reg) conversion. Interestingly, under the same T(reg) conversion conditions, peritoneal B1 cells preferentially promoted Th1 and Th17 cell differentiation. Blockade of CD86 but not CD80 costimulation markedly enhanced T(reg) cell induction by B1 cells. Thus, B cell antigen presentation function is inversely correlated with de novo T(reg) cell induction for these B cell subsets. Our findings suggest that B1 and B2 cell subsets play distinct roles in immune regulation by promoting reciprocal differentiation of T cell lineages.     

Correlative BOLD MR imaging of stages of synovitis in a rabbit model of antigen-induced arthritis

Background

Because of the ability of blood-oxygen-level-dependent (BOLD) MRI to assess blood oxygenation changes within the microvasculature, this technique holds potential for evaluating early perisynovial changes in inflammatory arthritis.

Objective

To evaluate the feasibility of BOLD MRI to detect interval perisynovial changes in knees of rabbits with inflammatory arthritis.

Materials and methods

Rabbit knees were injected with albumin (n?=?9) or saline (n?=?6) intra-articularly, or were not injected (control knees, n?=?9). Except for two rabbits (albumin-injected, n?=?2 knees; saline-injected, n?=?2 knees) that unexpectedly died on days 7 and 21 of the experiment, respectively, all other animals were scanned with BOLD MRI on days 0, 1, 7, 14, 21 and 28 after induction of arthritis. T2*-weighted gradient-echo MRI was performed during alternate 30?s of normoxia/hyperoxia. BOLD MRI measurements were compared with clinical, laboratory and histological markers.

Results

Percentage of activated voxels was significantly greater in albumin-injected knees than in contralateral saline-injected knees (P?=?0.04). For albumin-injected knees (P?P?=?0.009), the percentage of activated BOLD voxels varied over time. A quadratic curve for on-and-off BOLD difference was delineated for albumin- and saline-injected knees over time (albumin-injected, P?=?0.047; saline-injected, P?=?0.009). A trend toward a significant difference in synovial histological scores between albumin-injected and saline-injected knees was noted only for acute scores (P?=?0.07).

Conclusion

As a proof of concept, BOLD MRI can depict perisynovial changes during progression of experimental arthritis.     

靶向小干扰RNA抑制人神经母细胞瘤裸鼠荷瘤生长及转移的实验研究

目的 探讨靶向CXCR4的小干扰RNA(siRNA)对人神经母细胞瘤QDDQ-NM细胞裸鼠肿瘤的生长及转移的抑制作用.方法 采用本实验室已成功建立QDDQ-NM裸鼠荷瘤模型,以CXCR4为靶基因,设计合成siRNA序列及对照序列HK.通过瘤体局部多位点注射,将CXCR4-siRNA转染到裸鼠皮下荷瘤内.A组(阳性治疗组),B组(阴性治疗组),同时设立空载体对照组(C组)和空白对照组(D组).观察肿瘤的转移及治疗前后体积变化,并用RT-PCR方法及免疫组化方法检测CXCR4的基因转录及蛋白表达情况,来评价CXCR4-siRNA对肿瘤的作用.结果 A组转移率为25％明显小于其余3组对照组(75％,58％,75％),其肿瘤体积也显著低于其余3组,利用RT-PCR检测CXCR4基因在转录水平的表达,A组为1.0451±0.0778,B、C、D组分别为1.4286±0.0655、1.3839±0.0037、1.3882±0.0733(P＜0.05),A组CXCR4蛋白表达水平也显著低于B、C、D组(P＜0.05).结论脂质体介导的CXCR4-siRNA对神经母细胞瘤的生长及转移有明显抑制作用,可为下一步肿瘤治疗提供基础.     

Epidural spinal cord stimulation plus quipazine administration enable stepping in complete spinal adult rats

We hypothesized that epidural spinal cord stimulation (ES) and quipazine (a serotonergic agonist) modulates the excitability of flexor and extensor related intraspinal neural networks in qualitatively unique, but complementary, ways to facilitate locomotion in spinal cord-injured rats. To test this hypothesis, we stimulated (40 Hz) the S(1) spinal segment before and after quipazine administration (0.3 mg/kg, ip) in bipedally step-trained and nontrained, adult, complete spinal (mid-thoracic) rats. The stepping pattern of these rats was compared with control rats. At the stimulation levels used, stepping was elicited only when the hindlimbs were placed on a moving treadmill. In nontrained rats, the stepping induced by ES and quipazine administration was non-weight bearing, and the cycle period was shorter than in controls. In contrast, the stepping induced by ES and quipazine in step-trained rats was highly coordinated with clear plantar foot placement and partial weight bearing. The effect of ES and quipazine on EMG burst amplitude and duration was greater in flexor than extensor motor pools. Using fast Fourier transformation analysis of EMG bursts during ES, we observed one dominant peak at 40 Hz in the medial gastrocnemius (ankle extensor), whereas there was less of dominant spectral peak in the tibialis anterior (ankle flexor). We suggest that these frequency distributions reflect amplitude modulation of predominantly monosynaptic potentials in the extensor and predominantly polysynaptic pathways in the flexor muscle. Quipazine potentiated the amplitude of these responses. The data suggest that there are fundamental differences in the circuitry that generates flexion and extension during locomotion.     

脊神经后支形态特点及其阻滞麻醉下腰椎间盘手术4063例报告

目的 :介绍一种安全、简便、有效的腰椎间盘手术的局麻方法—脊神经后支阻滞法。方法 :0 .5 %普鲁卡因 10 0ml和 2 %利多卡因 2 0ml混合备用。先在切口处皮内注射 5ml麻药 ,再于开窗侧阻滞 5根脊神经后支主干 (上 3下 2 ) ,麻药用量 3～ 5ml。脊神经后支主干位于横突根部上缘。其体表投影点的确定方法是通过上下棘突连线的上中 1 3交界点作一水平线 ,该线是横突的上缘线的体表投影 ;旁开腰 1棘突 2cm取一点 ;再旁开腰 5棘突 3cm取一点 ;通过这两点作一直线 ,该线与各横线的交点即为各脊神经后支主干部的发出点。结果 :40 63例麻醉效果 :优 72 .2 % ,良 2 4.6% ,中 3 % ,差 0 .2 %。效果差者 ,经静脉使用镇痛镇静类药也取得较好效果。结论 :腰椎间盘手术采用脊神经后支阻滞麻醉经济安全可靠。     

组织工程化心脏瓣膜的研究进展

心脏瓣膜置换术是外科治疗瓣膜性心脏病的主要方法，但目前临床应用的人工瓣膜的远期效果尚不满意。近年来，随着组织工程学技术的进展，利用培养的自身组织细胞种植于支架材料表面，体外重新构建理想的心脏瓣膜植物日益成为研究热点。本文简述了心脏瓣膜工程的定义，细胞支架材料的选择，种子细胞的培养、种植方法以及组织工程化心脏瓣膜的评估，并指出下一步研究中尚需解决的问题。