PEG-g-chitosan thermosensitive hydrogel for implant drug delivery: cytotoxicity,in vivo degradation and drug release

Thermosensitive hydrogels based on chitosan are of great interests for injectable implant drug delivery. The poly(ethylene glycol)-grafted-chitosan (PEG-g-CS) hydrogel was reported as a potential thermosensitive system. The objective of the present study is to evaluate the cytotoxicity, in vivo degradation and drug release of PEG-g-CS hydrogel. Cytotoxicity was evaluated using L929 murine fibrosarcoma cell line. Degradation and drug release in vivo were investigated by subcutaneous injection of the hydrogel into Sprague-Dawley rats. PEG-g-CS polymer exhibits no significant cytotoxicity when its concentration is less than 3 mg mL^?1. After being implanted, PEG-g-CS hydrogel maintains its integrity for two weeks and collapses, merging into the tissue, in the third week. It causes moderate inflammatory response but no fibrous encapsulation around the hydrogel is found. The hydrogel presents a three-week sustained release of cyclosporine A with no significant burst release in vitro and produces the effective drug concentration in blood for more than five weeks in vivo, performing almost the same bioavailability to chitosan/glycerophosphate hydrogel. Further modifications of PEG-g-CS hydrogel might be necessary to modulate the degradation and to mitigate the fluctuations in blood drug concentration.     

Ultrasonographic features of Langerhans cell histiocytosis of the thyroid

Langerhans cell histiocytosis (LCH) is a rare disease, especially when it involves the thyroid gland. Awareness of ultrasonic features will be helpful for a clinician who should consider this disease in the differential diagnosis from other more common thyroid disorders, especially prior to surgery. Here, we report two patients who have histologically confirmed LCH of the thyroid and summarize the reported cases with ultrasonographic scans from the last 10 years (n=10). Ultrasonograms showed isolated or multiple hypoechoic nodules in unilateral or bilateral thyroid gland. Internal acoustic features of most nodules was heterogeneous (n=5) or hypoechoic (n=2).     

Extraction and Isolation of Alkaloids of Sophora Alopecuroides and Their Anti-Tumor Effects in H22 Tumor-Bearing Mice

Background

Alkaloids of Sophora alopecuroides have good biological activity, and are widely used in clinical settings, which not only have pharmacological activities of anti-cancer, cancer suppression, as well as the inhibition, and killing of various microorganisms; but also possess extensive pharmacological effects on immune system, nervous system and cardiovascular system. The objective of this paper was to extract and isolate total alkaloids of Sophora alopecuroides (TASA), and to study their anti-tumor effects in H22 tumor-bearing mice.

Materials and Methods

TASA were extracted and isolated using thin-layer chromatography, and column chromatography; and the isolated compounds were analyzed using nuclear magnetic resonance. The inhibitory effects of TASA on tumor in H22-bearing mice were determined by MTT assay.

Results

Three compounds were isolated from Sophora alopecuroides L., which were matrine, oxymatrine and sophoridine, respectively. Meanwhile, mouse H22 sarcoma model was established and different doses of TASA apparently inhibited solid H22-tumor in mice; it inhibited the thymus, and spleen to some extent; the degree of inhibition was more obvious for the spleen.

Conclusion

TASA has an anti-tumor effect in H22 tumor-bearing mice.     

Inflammatory signaling regulates embryonic hematopoietic stem and progenitor cell production

Identifying signaling pathways that regulate hematopoietic stem and progenitor cell (HSPC) formation in the embryo will guide efforts to produce and expand HSPCs ex vivo. Here we show that sterile tonic inflammatory signaling regulates embryonic HSPC formation. Expression profiling of progenitors with lymphoid potential and hematopoietic stem cells (HSCs) from aorta/gonad/mesonephros (AGM) regions of midgestation mouse embryos revealed a robust innate immune/inflammatory signature. Mouse embryos lacking interferon γ (IFN-γ) or IFN-α signaling and zebrafish morphants lacking IFN-γ and IFN-ϕ activity had significantly fewer AGM HSPCs. Conversely, knockdown of IFN regulatory factor 2 (IRF2), a negative regulator of IFN signaling, increased expression of IFN target genes and HSPC production in zebrafish. Chromatin immunoprecipitation (ChIP) combined with sequencing (ChIP-seq) and expression analyses demonstrated that IRF2-occupied genes identified in human fetal liver CD34⁺ HSPCs are actively transcribed in human and mouse HSPCs. Furthermore, we demonstrate that the primitive myeloid population contributes to the local inflammatory response to impact the scale of HSPC production in the AGM region. Thus, sterile inflammatory signaling is an evolutionarily conserved pathway regulating the production of HSPCs during embryonic development.     

Lipoxin A4 Inhibits NF-κB Activation and Cell Cycle Progression in RAW264.7 Cells

Lipoxins (LXs), including lipoxin A₄ (LXA₄), etc., have been approved for potent anti-inflammatory and immunomodulatory properties. Based on the important roles of macrophages in inflammation and immunomodulation, we investigate the effects of LXA₄ on lipopolysaccharide (LPS)-induced proliferation and the possible signal transduction pathways in RAW264.7 macrophages. RAW264.7 cells were treated in vitro with or without LPS in the absence or presence of LXA₄. [³H]-TdR incorporation assay and flow cytometry were used for detecting cell proliferation and cycle, respectively. Moreover, Western blot was applied to evaluate the protein expression levels of Cyclin E, IκBα, nuclear factor-κB (NF-κB), and IκB kinase (IKK). Our research showed that LXA₄ suppressed LPS-induced proliferation, increased the proportion of the G₀/G₁ phase, decreased the proportion of the S phase, and downregulated the expression of Cyclin E. Besides these, LXA₄ suppressed LPS-induced IκBα degradation, NF-κB translocation, and the expression of IKK. The data suggested that LXA₄ inhibited LPS-induced proliferation through the G₀/G₁ phase arrest in RAW264.7 macrophages, and the inhibitory effect might depend on NF-κB signaling transduction pathway.     

Vascular Risk Factor Burden,Atherosclerosis, and Functional Dependence in Old Age: A Population-Based Study

Background

Vascular risk factors such as hypertension and obesity have been associated with physical limitations among older adults.

Purpose

The purpose of this study is to examine whether individual and aggregated vascular risk factors (VRFs) are associated with functional dependence and to what extent carotid atherosclerosis (CAS) or peripheral artery disease (PAD) may mediate the possible associations of aggregated VRFs with functional dependence.

Method

This cross-sectional study included 1,451 community-living participants aged ≥60 years in the Confucius Hometown Aging Project of China. Data on demographic features, hypertension, high total cholesterol, obesity, smoking, physical inactivity, diabetes, CAS, PAD, and cardiovascular diseases (CVDs) were collected through an interview, a clinical examination, and laboratory tests. Functional dependence was defined as being dependent in at least one activity in the personal or instrumental activities of daily living. Data were analyzed using multiple logistic models controlling for potential confounders. We used the mediation model to explore the potential mediating effect of CAS and PAD on the associations of aggregated VRFs with functional dependence.

Results

Of the 1,451 participants, 222 (15.3 %) had functional dependence. The likelihood of functional dependence increased linearly with increasing number of VRFs (hypertension, high total cholesterol, abdominal obesity, and physical inactivity) (p for trend <0.002). Mediation analysis showed that controlling for demographics and CVDs up to 11 % of the total association of functional dependence with clustering VRFs was mediated by CAS and PAD.

Conclusion

Aggregation of multiple VRFs is associated with an increased likelihood of functional dependence among Chinese older adults; the association is partially mediated by carotid and peripheral artery atherosclerosis independently of CVDs.     

盐酸戊乙奎醚对粘连性肠梗阻大鼠肠黏膜免疫屏障的保护作用

目的 探讨盐酸戊乙奎醚(PHC)对粘连性肠梗阻(AIO)大鼠肠黏膜免疫屏障功能的影响及可能机制.方法 将60只SD大鼠分为正常组(N组)、假手术组(S组)、生理盐水组(NS组)及盐酸戊乙奎醚组(P2、P4、P8组).建立AIO模型.正常组不予处理,生理盐水组及假手术组均给予0.4 ml生理盐水,PHC组按0.2、0.4、0.8 mg/kg配成0.4 ml,于术后第7d开始连续肌注7d.ELISA法测量血清中IL-4、IL-10含量以及肠内容物中分泌型免疫球蛋白A(sIgA)含量.结果 与S组、NS组比较,P2、P4、P8组血清IL-4[(19.34±2.87),(23.85±2.72),(27.89±2.71) vs (6.18±1.42),(8.37±2.69) ng/L)]、IL-10[(118.93±20.78),(121.61±24.932),(127.41±22.61) vs (78.19±19.41),(42.72±21.31) ng/L]以及肠内容物中sIgA含量(0.64±0.089,0.99±0.093,1.02±0.12 vs 0.41±0.06,0.14±0.03 ng/L)均有明显增高,差异均有统计学意义(均P＜ 0.05).与P2组比较,P4、P8组IL-4与sIgA水平升高更为明显,差异均有统计学意义(P＜ 0.05).结论 中、高剂量PHC对AIO大鼠肠黏膜的免疫屏障有一定保护作用,且以高剂量更为显著,其机制可能与增加抗炎因子释放和抑制炎性因子产生有关.     

干细胞移植治疗糖尿病肾病

背景：糖尿病肾病所致的终末期肾病已成为慢性肾功能衰竭的主要原因,传统的血液透析和肾脏移植已无法满足临床治疗的需求,以干细胞为基础的再生医学研究有可能为糖尿病肾病的治疗带来新的希望。 目的：综合分析不同来源干细胞治疗糖尿病肾病的机制及临床研究进展。 方法：应用计算机检索CNKI和PubMed数据库中2006年1月至2011年8月关于干细胞治疗糖尿病肾病的文章,在标题和摘要中以“胚胎干细胞;骨髓间充质干细胞;诱导性多能干细胞;糖尿病肾病”或Embryonic stem cells; Bone marrow mesenchymal stem cells;induced poluripotent stem cells;induced multipotent stem cells; diabetic nephropathy”为检索词进行检索。最终选择26篇文章进行综述。 结果与结论：胚胎干细胞、骨髓间充质干细胞、诱导性多能干细胞均具有向肾脏组织细胞分化的潜能,大量研究表明干细胞移植对肾脏损伤和修复具有积极的作用。通过对干细胞相关特性的描述和相关机制的研究,干细胞移植有可能为糖尿病肾病提供一种新型的治疗方案。     

微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折

目的探讨切开复位微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折的手术方法及疗效。方法2010年1月~2012年1月,对我院收治的15例闭合性距骨颈粉碎性骨折患者,根据Hawkins分型：Ⅱ型11例,Ⅲ型4例。术前常规行CT三维重建明确骨折类型和粉碎程度,择期行切开复位微型接骨板内固定加自体松质骨移植术。术后定期复查X片及CT观察骨折愈合情况,并记录相关并发症,采用Hawkins评分标准评估疗效。结果本组14例获得随访,随访时间12~24m,,平均16.4m。术后外侧切口边缘部分坏死1例,经局部清创换药后治愈,无并发感染,骨折均在8~12w内获得愈合,平均愈合时间11.3w,无畸形愈合发生,距骨体部分坏死1例（Ⅲ型）,轻度创伤性关节炎3例（Ⅱ型1例,Ⅲ型2例）,末次随访时未发现内固定松动断裂。Hawkins评分：优7例（Ⅱ型）,良5例（Ⅱ型4例,Ⅲ型1例）,可2例（Ⅲ型）。结论采用切开复位微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折,术中可获得满意复位,牢靠的内固定可有效维持骨折复位,自体松质骨移植可促进骨折愈合,是治疗距骨颈粉碎性骨折的有效方法。