In vivo vascular engineering: directed migration of smooth muscle cells to limit neointima

Pathologic neointima formation requires directional smooth muscle cell (SMC) migration from media to intima. The very direction of SMC migration thus becomes a potential therapeutic target. Here, we hypothesize that proliferating SMC after injury can be redirected using engineered chemotactic gradients of elastin degradation to limit late pathologic neointima formation. Buffered bioerodible polymeric microspheres (MS) were constructed to provide 4-week sustained release of elastase, heat-killed elastase, or polymer only. In vitro elastase function and timecourse of release at 37 degrees C, physiologic pH, and shear was determined. Curves revealed an initial bolus followed by sustained linear release for elastase MS, while controls exhibited baseline hydrolysis of substrate. We then employ controlled perivascular release of elastase after angioplasty to engineer modified in vivo gradients of elastin degradation in rabbit femoral arteries. NZW rabbits (n = 8 each) underwent balloon angioplasty of the common femoral artery followed by perivascular distribution of MS. Significant early perivascular elastin degradation resulted. Concurrently, proliferating SMC were guided peripherally (further from lumen) with treatment without significant changes in total proliferation or inflammation. At 28 days, treatment significantly reduces neointima by 42% relative to controls. These results confirm that directionally guiding SMC responses after injury achieves favorable arterial remodeling and limits development of pathologic neointima. Thus, a potential class of therapeutics and the paradigm of in vivo vascular engineering emerge from this work.     

Immunohistochemical study of p53, p21 and PCNA in pterygium

Since mutated p53 is one of the most frequent gene abnormalities in human cancer, we hypothesized that mutation of p53 may play an important role in growth and recurrence of pterygia, a dysplasia of the conjunctiva. Therefore, we compared pterygia of Japanese and Tunisian patients using antibodies against p53, p21 and proliferating cell nuclear antigen (PCNA). In Nagasaki, 21 pterygia of Japanese individuals were removed and in Gabes, 19 primary pterygia of Tunisian individuals. Positive staining of wild type p53 was not found in the Japanese pterygia, whereas 38.1% were positive for mutant p53, none were positive for p21 and 76.2% were positive for PCNA. The incidence of mutant p53-positive staining was 50.0% in males and 22.2% in females, which was statistically significant. In the 19 Tunisian patients, positive staining of wild type p53 was not found, whereas 36.8% were positive for mutant p53, 0% for p21 and 63.1% for PCNA. Differences between Japanese patients and Tunisian patients were not significant. There were 2 types of pterygium. One type did not show mutant p53 and the other showed mutant p53 caused by ultraviolet light. However, damage caused by p53-dependent programmed cell death of pterygium cells may lead to mutations in other genes which may allow the progressive multistep development of limbal tumors. It is possible that mutant p53-positive pterygia can develop into limbal tumors.     

Response of Balloon-Expandable Endoprosthetic Metallic Stents Subjected to Over-Expansion <Emphasis Type="Italic">In Vitro</Emphasis>

We attempted to evaluate the in vitro behavior and performance of balloon-expandable endoprosthetic metallic stents subjected to over-expansion (OE). Seventy-two balloon-expandable endoprosthetic stents, representing 22 models from six manufacturers, were over- expanded in vitro. Stents were initially expanded to their maximum manufacturer- recommended diameter and then over-expanded incrementally to their endpoints. Endpoints for OE were either stent disarticulation or an inability to undergo further expansion despite balloon insufflation to maximum burst pressure. Measurements of stent dimensions were recorded at each overexpanded diameter and comparisons were made to manufacturers specifications. A total of 288 balloon-driven expansions were performed on 72 stents. Sixteen stents were expanded to large diameters ( 16 mm), 20 stents underwent OE of 50% or greater. One model tended to disarticulate after OE greater than 50%. There were five models that had a tendency to disarticulate after minimal OE. Five models were resistant to OE (25% or less OE) but did not disarticulate. Nearly all stents showed some degree of foreshortening with OE, while 36 stents underwent foreshortening of 30% or more. Models that are not recommended for OE include Intrastent, Intrastent DoubleStrut, NIR Royale and Omniflex. Good candidates for OE include Intrastent DoubleStrut LD, Palmaz large, Medtronic Extra Support Biliary Plus and Medtronic Flexible Biliary. Palmaz XL remains the only model available for expansion from 20 to 28 mm in diameter. For the remaining stents, OE is possible, however, caution should be used.     

穿心莲酸对高脂饲料喂养C57BL/6及NLRP3基因敲除小鼠脂质及炎症水平的影响

目的研究穿心莲酸对高脂饲料喂养C57BL/6及NLRP3基因敲除小鼠脂质及炎症水平及其相关蛋白的影响。方法将18只C57BL/6小鼠和18只NLRP3基因敲除小鼠分别随机分为3组,每组6只,雌雄各半。分别为对照组(Control)、模型组(HFD)、穿心莲酸(ANDA,12.5 mg·kg-1)组。对照组小鼠给予维持饲料,其余小鼠每笼每天给予20 g高脂饲料喂养(high fat diet,HFD),连续8周。第5周起,ANDA组连续灌胃给药4周,其他组小鼠灌胃给予蒸馏水,每天1次。收集血样及肝脏,测定血清中TC、TG、HDL-c、LDL-c及IL-1β水平;Western Blot测定肝脏中caspase-1、IL-1β、CYP7A1及LXRα的蛋白表达水平。结果给予高脂饲料喂养后,WT小鼠和NLRP3-/-小鼠血清TC、TG、LDL-c水平均较对照组显著升高、HDL-c水平显著下降(P<0.01);与对应模型组相比较,穿心莲酸均能降低高脂饲料喂养的WT小鼠和NLRP3-/-模型小鼠血清TC、TG、LDL-C含量,提高HDL-c含量(P<0.01或P<0.05)。穿...     

精神分裂症患者外周色氨酸-犬尿氨酸代谢通路中代谢物水平与临床症状的关系

背景 精神分裂症是一种常见的重性精神障碍,其发病机制复杂,目前关于精神分裂症外周血清和尿液犬尿氨酸（KYN）代谢物相关性的研究有限。目的 分析精神分裂症患者外周血清和尿液色氨酸（TRP）-KYN代谢物与白细胞介素-6(IL-6)的浓度以及血清与尿液KYN代谢物的相关性以及代谢物水平与临床症状的相关性,以期为探索精神分裂症的潜在生物标志物提供参考。方法 纳入2021年12月—2022年12月在杭州市第七人民医院住院治疗或门诊就诊的、符合《精神障碍诊断与统计手册（第5版）》（DSM-5）精神分裂症诊断标准的38例患者为研究对象,同期在杭州市社区招募健康对照组共26例。采用阳性和阴性症状量表（PANSS）评定患者的精神病性症状,采用超高效液相色谱串联三重四极杆质谱技术检测所有受试者血清和尿液TRP、KYN、犬尿喹啉酸（KYNA）、喹啉酸（QUIN）、吡啶甲酸（PIC）、黄尿酸和5-羟色胺（5-HT）水平,采用酶联免疫分析检测血清和尿液IL-6水平。采用Pearson相关分析考查精神分裂症患者血清与尿液TRP-KYN代谢物之间的相关性以及代谢物水平与临床症状的相关性。结果 精神分裂症患者血清...     

Stent-based controlled release of intravascular angiostatin to limit plaque progression and in-stent restenosis

PURPOSE: To evaluate the importance of angiogenesis in plaque progression after stent placement, this study examines stent-based controlled delivery of the antiangiogenic agent, angiostatin, in a rabbit model. MATERIALS AND METHODS: Controlled release biodegradable microspheres delivering angiostatin or polymer-only microspheres (polylactic-co-glycolic-acid-polyethylene glycol; PLGA/PEG) were loaded in channeled stents, anchored, and deployed in the aorta of adult New Zealand white rabbits (n = 6 animals per group, three each per time point). The stented aortas were harvested at 7 days and 28 days and evaluated for neovascularization, local inflammation, vascular smooth muscle cell proliferation, and in-stent plaque progression. RESULTS: At 7 days, neovascularization was significantly decreased in the angiostatin groups (1.6 +/- 1.6 neovessels per mm(2) plaque) versus the control group (15.4 +/- 2.6 neovessels per mm(2) plaque; P =.00081), as were local inflammation where angiostatin-treated groups demonstrated significantly lower macrophage recruitment per cross section (34.9 +/- 4.9 cells per cross section) relative to the control group (55.2 +/- 3.84 cells per cross section; P =.0037). And a significant decrease in the overall vascular smooth muscle cell proliferation (143.8 +/- 26.3 Ki-67 positive cells per mm(2)) relative to the control group (263.2 +/- 16.6 Ki-67 positive cells per mm(2); P =.00074). At both 7 and 28 days, in-stent plaque progression in the angiostatin groups was successfully limited relative to the control group by 54% (0.255 +/- 0.019% of cross section; P =.00016) and 19% (1.981 +/- 0.080; P =.0033) respectively and resulted in reduction of in-stent restenosis relative to the control group. CONCLUSION: Angiostatin-eluting stents may limit neovascularity after arterial implantation, offer insight into in-stent restenosis, and allow future refinement of bioactive stent designs and clinical strategies, particularly in light of evidence that intimal smooth muscle cells may in part be marrow-derived.     

Local resistance to oxidative stress by overexpression of copper-zinc superoxide dismutase limits neointimal formation after angioplasty.

PURPOSE: To examine the effects of oxidative stress on neointimal hyperplasia through local overexpression of human copper-zinc superoxide dismutase (Cu-Zn SOD). METHODS: The left common femoral arteries (CFA) of 18 New Zealand white rabbits were subjected to balloon overdilation injury. Each dilated CFA was then incubated with either a nonviral (buffer) or viral (adenovirus overexpressing beta-galactosidase) control or an adenovirus overexpressing Cu-Zn SOD. Animals were then sacrificed at 3, 7, or 28 days (3 arteries per group per time point) and the treated CFA segments were harvested for analysis of esterase-positive inflammatory cells and extracellular matrix elements. The intima-to-media ratio (I/M) was measured to assess the degree of neointimal formation. RESULTS: At 3 days, local SOD levels in the Cu-Zn SOD-treated group were significantly elevated relative to both controls (p<0.01). Significant reductions in lipid peroxidation byproducts were also seen in the SOD group relative to viral and nonviral controls (p<0.05). Mean I/M at 28 days was 0.582+/-0.088 for the nonviral control group versus 0.565+/-0.133 for the viral control group. The SOD-treated group had a significant reduction relative to both controls: 0.259+/-0.045 (p<0.05). Statistically significant reductions in I/M were also demonstrated in the SOD group relative to control groups at 7 days (p<0.05). The SOD-treated group demonstrated significant preservation of elastin relative to controls, as well as a significant reduction in esterase-positive granulocytes relative to controls (p<0.05). CONCLUSIONS: Direct buffering of oxidative stress in balloon-injured vessels can significantly alter postinjury response and limit neointimal hyperplasia.     

双源计算机断层扫描双能量结肠镜检测结肠肿瘤准确性的临床研究

目的：比较常规 CT 结肠镜（CTC）与双能量 CTC 检测占位性病变的准确性。方法选择临床怀疑有结肠占位性病变患者28例,均采用双能量增强 CT 扫描,并进行结肠镜重建和双能量碘图重建。比较结肠占位性病变的直径、增强后 CT 值和含碘值。以结肠镜及病理结果作为金标准,比较常规 CTC 和双能量 CTC 诊断结肠占位性病变的敏感度、特异度、准确率、阳性预测值和阴性预测值。多组间的计量资料比较采用方差分析,计数资料比较采用卡方检验。结果28例患者中,CTC 检出结肠占位性病变24例,经结肠镜及病理证实假阳性4例,假阴性1例。双能量 CTC 检出结肠占位性病变20例,经结肠镜及病理证实无假阳性患者,假阴性1例。腺瘤样息肉、腺瘤、腺癌和粪块增强后的 CT 值分别为（38．54±6．82）、（49．16±7．31）、（52．61±5．93）和（34．00±1．41）Hu,腺瘤和腺癌的强化值明显高于腺瘤样息肉和粪块,差异有统计学意义（F ＝10．760,P ＝0．001）;息肉与粪块两组间比较,差异无统计学意义（t ＝1．44,P ＝0．188）。常规 CTC 与双能量 CTC 检测占位性病变的敏感度分别为95．6％（95％CI ：77．9％～99．2％）和95．6％（95％CI ：77．9％～99．2％）,特异度分别为42．8％（95％CI ：15．4％～93．5％）和100．0％（95％CI ：47．9％～100．0％）。结论与传统的 CTC 相比,双能量 CTC 可区分粪便残渣与肿块,有助于肿瘤良恶性的鉴别,进一步提高 CTC 诊断的准确性。     

Effect of IGFBP-derived peptides on incorporation of(35)SO(4)into proteoglycans.

18 amino acid peptides from the C-terminal region of IGFBP-3, -5 (P3, P5), increased the incorporation of(35)SO(4)into proteoglycans in endothelial cells with greater stimulation in large vessel than microvessel cells. The homologous region of IGFBP-6 (P6) also stimulated sulfate uptake, but less potently than P3 and P5. P6 variants were synthesized with one or two amino acids changed to the basic amino acid in the equivalent position of P3. The P6 variants with one additional basic amino acid behaved similarly to P6. The P6 mutant with two altered amino acids was equipotent to P3. P3F, a scrambled version of P3 was less effective than P3. P3, P5, P6, P3F and all P6 variants all stimulated glucose uptake, which occurred only in microvessel cells. P1, P2, P4, and equimolar intact IGFBP-3 stimulated neither glucose uptake nor sulfate incorporation. Thus, C-terminal basic portions of IGFBP-3, -5 and -6 alter two specific functions of endothelial cells with sufficient differences to suggest mediation by distinct mechanisms.