特异亲合转录因子E2F的寡脱氧核苷酸对移植静脉内膜增生的影响

目的　观察E2F亲合性寡脱氧核苷酸对大鼠自体移植静脉内膜增生的影响。方法以Wistar大鼠建立自体静脉移植模型 ,术中将含有E2F亲合性双链寡脱氧核苷酸的医用生物胶涂沫于移植静脉的外膜。术后 14d取移植静脉 ,观察细胞周期基因c myc ,核增殖抗原基因 (PCNA)的表达指数和内膜增生程度。以空白胶和错配双链寡脱氧核苷酸作为对照。结果　对照组移植静脉中有大量平滑肌细胞表达c myc和PCNA ,内膜明显增生。错配双链寡脱氧核苷酸对c myc ,PC NA的表达和内膜增生无抑制作用。当静脉外膜施加 10 0 μgE2F亲合性寡脱氧核苷酸时 ,PCNA和c myc的表达率分别是 ( 2 0 .41± 4.15 ) %、( 10 .83± 2 .87) % ,比对照静脉分别下降 5 0 %、34% ,内膜厚度为 ( 18.2± 2 .8) μm ,比对照组减轻 44% ( P <0 .0 5 )。 2 0 0 μg的E2F亲合性双链寡脱氧核苷酸对PCNA、c myc和内膜增生的抑制更为显著。 结论　E2F亲合性寡核苷酸可能通过抑制c myc、PCNA的表达抑制内膜增生 ,存在剂量效应关系。     

核转录因子κB decoy寡核苷酸对移植静脉内膜增生的影响

目的 研究核转录因子κB(NFKB)decoy寡核苷酸(decoy ODNs)对移植静脉内膜增生的抑制作用,探讨其作用机制。方法 Wistar大鼠72只,建立自体静脉移植模型,术后随机分为：对照组,NFκB decoyODNs 50μg、200μg组,杂码decoyODNs 50μg、200μg组,lipofectin pluronic组等6个组,施加不同的处理方法,在移植后1、2周取材。组织形态学方法比较内膜增生程度,半定量RT-PCR方法检测细胞间黏附分子(ICAM)-1的mRNA表达,Western blot和免疫组化方法检测p65、ICAM-1的蛋白产物表达。结果 移植后1、2周内膜增生明显,局部应用50μg NFκB decoyODNs明显抑制内膜增生,抑制率为22％-31％;200μg组受抑制程度更为明显,抑制率达41％～53％,其他组内膜增生无明显变化。NFκB decoyODNs能够抑制：ICAM-1mRNA表达,p65和：ICAM-1的蛋白表达均显著低于各对照组,抑制率为30％-57％。结论 NFκB decoyODNs可显著抑制移植静脉的内膜增生,其作用可能是通过减少黏附分子的基因转录及蛋白产物表达而实现的。     

Pharmacologic inhibition of vein graft neointimal hyperplasia

Although arterial conduits are widely used and have improved the long-term results of coronary artery bypass grafting, vein grafts remain important additional conduits in coronary surgery. Newer studies show a saphenous vein graft patency of 60% or more at 10 years postoperatively. The pathology of vein graft disease consists of thrombosis, neointimal hyperplasia, and vein graft atherosclerosis, which limit graft longevity. Therapeutic strategies to prevent vein graft disease include external stenting, pharmacotherapy, and gene therapy. The potential benefits of a pharmacologic approach are as follows: (1) Drugs with a broad clinical experience can be used; (2) side effects of systemic application can be minimized by local therapy; and (3) no vascular injury, such as pressurizing the vein for a viral transfection approach, is necessary. The different sites for pharmacotherapy in vein graft disease are reviewed in this article.     

Cilostazol suppresses neointimal hyperplasia in canine vein grafts

Purpose  To investigate whether cilostazol, a cyclic adenosine monophosphate (cAMP) phosphodiesterase inhibitor, suppresses intimal hyperplasia in canine vein grafts, and to elucidate its mechanisms in terms of cell proliferation and apoptosis. Methods  Bilateral reversed jugular vein interposition grafts of the common carotid artery were performed in 12 beagle dogs. Starting from 7 days before surgery, either cilostazol (30 mg/day; n = 6) or a placebo (n = 6) was given orally twice daily. Vein grafts were harvested at 1 or 4 weeks, and fixed under pressure for histological examination. Results  By 1 week after implantation, the cilostazol group showed significantly less cell proliferation than the placebo group. By 4 weeks after implantation, intimal and medial thickness was significantly thinner in the cilostazol group than in the placebo group. There was significantly more apoptosis in the placebo group than in the cilostazol group at both time points. Conclusion  Cilostazol suppressed the development of intimal hyperplasia in canine autogenous vein grafts. Thus, it may be associated with the modulation of cell proliferation and apoptosis.     

L-arginine polymers inhibit the development of vein graft neointimal hyperplasia

OBJECTIVE: We sought to determine whether L -arginine polymer treatment of vein grafts enhances vascular production of nitric oxide and inhibits the development of neointimal hyperplasia. METHODS: External jugular veins of New Zealand White rabbits (n = 42) were harvested; treated intraluminally for 15 minutes with phosphate-buffered saline solution or L -arginine polymer 5, 7, or 9 at either 10 or 100 micromol/L; and then grafted into the contralateral carotid artery. Rabbits were killed after 28 days, and 5-microm sections of vessels were stained with hematoxylin and scored for intima/media ratio by using computerized morphometric analysis. Separate veins were treated in a similar fashion with biotinylated polymers and phosphate-buffered saline solution to assess for translocation efficiencies. Finally, vein segments pretreated with either phosphate-buffered saline solution or L -arginine polymers were cultured in Dulbecco's modified Eagle's medium containing lipopolysaccharide (100 microg/mL) and interferon gamma (200 U/mL) for 48 hours before measuring nitric oxide levels by means of the Griess reaction. RESULTS: Biotinylated L -arginine polymers demonstrated a dose- and length-dependent uptake into intimal and medial cells of treated vessels. Nitric oxide levels were significantly higher in vein segments treated with 100 micromol/L of L -arginine polymer 9 compared with control segments. Finally, the intima/media ratio also reflected both length- and concentration-dependent inhibition of neointimal hyperplasia.intima/media ratio PBS R5 R7 R9 10 micromol/L 0.909 +/- 0.072 0.920 +/- 0.073 0.861 +/- 0.138 0.710 +/- 0.122 100 micromol/L 0.924 +/- 0.061 0.581 +/- 0.089* 0.529 +/- 0.093* PBS, Phosphate-buffered saline solution; R, L -arginine polymer. *P <.001 versus phosphate-buffered saline solution and L -arginine polymer 5 controls (Bonferroni-corrected value). CONCLUSIONS: Arginine polymers of sufficient length and concentration were effective in increasing nitric oxide levels and reducing neointimal hyperplasia in this vein graft model.     

反义寡核苷酸抑制Survivin基因表达对移植静脉内膜增生的影响

目的研究反义寡脱氧核苷酸（ASODN）抑制Survivin基因表达对移植静脉内膜增生的抑制作用。方法Wistar大鼠60只，建立自体静脉移植模型，术后随机分为：对照组、Survivin ASODN 50、200μg组、正义对照组、Lipofectin＋pluronic等五个组，施加不同的处理因素，在移植后1、2周取材。组织形态学方法比较内膜增生程度，逆转录．聚合酶链反应（RT-PCR）检测Survivin基因的mRNA表达，Westem blot检测Survivin基因的蛋白产物表达，免疫组织化学方法检测Survivin及增殖细胞核抗原（PCNA）的表达，脱氧核苷酸转移酶末端标记法（TUNEL）检测血管平滑肌细胞（VSMC）凋亡的变化。结果移植后1、2周内膜增生明显，局部转染50μg Survivin ASODN组内膜增生明显受抑制（P〈0．05），200μg组受抑制程度更为明显（P〈0．05）；与对照组相比，Survivln ASODN组Survivin的mRNA及蛋白产物表达显著减少（P〈0．05），PCNA阳性表达同时减少，而TUNEL阳性细胞却明显增加。结论Survivin ASODN可显著抑制移植静脉的内膜增生，其作用可能是通过抑制Survivin基因及其蛋白产物表达，从而抑制VSMC增殖、促进其凋亡而实现的。     

An appropriately sized soft polyester external stent prevents enlargement and neointimal hyperplasia of a saphenous vein graft in a canine model

Although the efficacy of external stents for vein grafts in coronary artery bypass grafting has been recognized, the ideal diameter and material of the stent remain controversial. We created a new external stent made of soft polyester mesh and performed an animal experiment using canines. Bilateral saphenous vein grafts were interposed in the bilateral common carotid artery of 10 beagles. The grafts in the left carotid artery were designated as the control group, and those in the right rolled by a soft polyester mesh external stent were designated as mesh group. Two of the 10 animals were sacrificed due to severe wound infection. The other eight were observed by echography for 6 months, and then grafts were extracted and thickness of the neointima of the grafts was measured. The control group showed 146% ± 26% postoperative enlargement of the internal diameter of the vein grafts after 6 months, whereas the mesh group showed only 115% ± 15% after the same duration (P = 0.0003). The median thickness of the neointima in the mesh group (170 µm [range: 150–190]) was significantly thinner than that in the control group (260 µm [range: 220–310], P < 0.0001). Some degree of correlation between the thickness of neointima and proportion of enlargement was noted (r = 0.518, P = 0.0024). A soft polyester mesh external stent for vein grafts successfully suppressed the enlargement of the vein grafts and thickness of the neointima after 6 months.     

Locally applied cilostazol suppresses neointimal hyperplasia and medial thickening in a vein graft model.

BACKGROUND: Pathological changes in vein grafts begin immediately after arterial circulation is applied to the grafts. Chemical mediator stimulation and mechanical strain induce neointimal hyperplasia and medial thickening of the vein grafts, resulting in their failure. We investigated the inhibitory effect of locally applied cilostazol, an inhibitor of cyclic adenosine monophosphate phosphodiesterase III, on neointimal hyperplasia and medial thickening of the grafts. METHODS AND RESULTS: We established a distal anastomotic stricture model of femoral vein-abdominal aorta interposition grafting in rats. In this model, neointimal hyperplasia was observed not only at the distal anastomotic sites, but also in the graft body at postoperative day 14 and was markedly progressed at day 28. A strong expression of tenascin-C was found in the media and neointima of the graft body. In the grafts around which cilostazol was administered locally using Pluronic gel, neointimal hyperplasia was significantly suppressed compared with control grafts treated with the gel alone, with the mean neointimal cross-sectional area reduced by 87.1% for the graft body and by 78.9% for the distal anastomotic sites and mean medial cross-sectional area of the graft body reduced by 54.2% at day 28 versus the control. Cilostazol treatment decreased cell proliferation and the number of tenascin-C-producing cells seen by in situ hybridization, but the expression of tenascin-C protein was not suppressed. CONCLUSION: We concluded that a single perivascular application of cilostazol inhibits neointimal hyperplasia and medial thickening of vein grafts in a rat model.     

Peptide inhibition of neointimal hyperplasia in vein grafts.

Angiopeptin, a novel synthetic octapeptide, was evaluated as a new approach toward the inhibition of neointimal hyperplasia in vein grafts. Male New Zealand white rabbits (n = 22) underwent carotid artery interposition bypass grafting with autologous reversed jugular vein. Nine rabbits were in the treatment group, and 13 were in the control group. The treatment group received angiopeptin 20 micrograms/kg/day by subcutaneous injection beginning 1 day before operation and continuing for 3 weeks until they were killed. At death the vein grafts were fixed in situ with 10% buffered formalyn at 80 mm Hg perfusion pressure. Histologic sections through each vein graft were analyzed by computerized morphometric analysis for area of neointimal hyperplasia (mm2). Neointimal hyperplasia in the control animals was 0.080 + 0.017 mm2 (mean + SEM), whereas neointimal hyperplasia in the group treated with angiopeptin was 0.022 + 0.006 mm2 (mean + SEM) (p = 0.02). This is the first time that peptide inhibition of neointimal hyperplasia has been demonstrated in vein grafts and may have significant implications for future use in vascular surgery.     

Effect on vein graft intimal hyperplasia of nuclear factor-kB decoy transfection using the second generation of HVJ vector

AIM: Vein graft stenosis due to intimal hyperplasia (IH) is the main cause of graft failure. We examined possibilities of nuclear factor-kB (NF-kB) expression in vein grafts, and inhibitive effects of NF-kB decoy on the gene expression and subsequent vein graft IH. METHODS: Fifteen mongrel dogs underwent femoral artery replacement with autogenous vein grafts. Group I: grafts were retrieved at a predetermined time and subjected to NF-kB binding activity assay; Groups II and III: grafts were transfected with scrambled (II-a, III-a) or NF-kB (II-b, III-b) decoy using hemagglutinating virus of Japan envelope before implantation. Grafts were retrieved 7 days after implantation for evaluation of intercellular adhesion molecule-1 (ICAM-1) mRNA expression (Group II) and 4 weeks after implantation for comparison of IH by morphometric analysis (Group III). RESULTS: NF-kB binding activity was increased in a time-dependent manner, with a peak 2 days after implantation. The ratio between ICAM-1 and glyceraldehyde-3-phosphate dehydrogenase mRNA expression in II-b was significantly lower than that in II-a (0.347 +/- 0.07 versus 0.612+/-0.08; P = 0.047). The ratio of intimal cross-section area to luminal cross-section area of III-b was significantly lower than that of the III-a (0.096+/-0.03 versus 0.461+/-0.11; P = 0.048). CONCLUSION: NF-kB binding activity in vein grafts increases after implantation, and transfection of NF-kB decoy before implantation may reduce IH through the inhibition of ICAM-1 expression.     

重组arresten蛋白对自体移植静脉内膜增生的抑制作用

目的 观察原核表达人arresten重组蛋白对自体移植静脉内膜增生的抑制作用.方法 用pRSET原核表达系统表达并纯化人arresten重组蛋白.将Wistar大鼠颈外静脉移植于腹主动脉,建立大鼠自体静脉移植模型,实验分3组:假手术组、移植对照组和移植实验组.自术后第3天起,皮下注射给予arresten重组蛋白(每日4 mg/kg体重)处理.4周后取移植静脉组织标本,进行病理组织学观察与免疫组织化学染色分析.结果 移植组移植静脉均呈现典型的内膜增生、肥厚,导致血管管腔狭窄;新生内膜主要有过度增殖的α-SMA染色阳性平滑肌细胞组成.移植实验组移植静脉内膜增生受到明显抑制,新生内膜面积(0.12±0.07)mm2及新生内膜/中膜面积比(0.373±0.085)均显著低于对照组[(0.38±0.11)mm2,1.621±0.086,P<0.01];并且实验组移植静脉新生内膜细胞PCNA标记指数显著低于对照组[(15.62±3.97)%比(56.36±3.49)%,P<0.01].结论 重组arresten蛋白通过抑制新生内膜平滑肌细胞的增殖能有效抑制自体移植静脉内膜增生的发生发展,在防治血管重建术后再狭窄方面显示出良好的应用前景.     

Local application of rapamycin inhibits neointimal hyperplasia in experimental vein grafts

BACKGROUND: Rapamycin is an immunosuppressive agent which also exhibits marked antiproliferative properties. Rapamycin coated stents have been demonstrated to suppress restenosis in experimental and clinical studies of percutaneous coronary catheter intervention. We investigated whether rapamycin can reduce neointima formation in a mouse model of vein graft disease. METHODS: C57BL6J mice underwent interposition of the inferior vena cava from isogenic donor mice into the common carotid artery using a previously described cuff technique. In the treatment group, 100 microg or 200 microg of rapamycin was applied locally in pluronic gel. The control group did not receive local treatment. Grafts were harvested at 1, 2, 4, and 6 weeks and underwent morphometric analysis as well as immunohistochemical analysis. RESULTS: In grafted veins without treatment (controls), median intimal thickness was 9.6 (6.4 to 29)microm, 11.9 (7.9 to 39.9)microm, 46.6 (12.4 to 57.7)microm, and 57.5 (32.5 to 71.1)microm after 1, 2, 4, and 6 weeks, respectively. Treatment with 100 microg or 200 microg rapamycin showed a dose dependent reduction of intimal thickness. In the 200 microg rapamycin treatment group the intimal thickness was 4.3 (3.4 to 5.6)microm, 3.8 (3.2 to 6.3)microm, 17.1 (4.8 to 63)microm, and 33.9 (11.3 to 80.3)microm after 1, 2, 4, and 6 weeks, respectively. This difference of intimal thickness of 200 microg treated animals compared with controls was statistically significant at 1 and 2 weeks. Immunohistochemically the reduction of intimal thickness was associated with a decreased amount of infiltration of CD-8 positive cells and a decreased amount of metallothionein positive cells in the rapamycin treated grafts. CONCLUSIONS: We conclude that perivascular application of rapamycin inhibits neointimal hyperplasia of vein grafts in a mouse model. These results suggest that rapamycin may have a therapeutic potential for the treatment of vein graft disease.     

血管外雷帕霉素缓释涂层抑制移植静脉再狭窄

目的观察血管周围局部应用雷帕霉素对兔自体移植静脉段内膜过度增殖的抑制作用,并初步探讨其作用机制。方法大耳白兔30只,采用自身对照设计建立模型。任取一侧静脉旁路为干预组,外涂含0.3 mg雷帕霉素的Pluronic凝胶;另一侧为对照组,外涂空凝胶。4周后测旁路静脉内膜厚度、细胞的增殖指数及PCNA、P27~(kipl)免疫组化阳性细胞数。并于术后1、2、4、8周检测血管壁中雷帕霉素的含量。结果干预组旁路静脉内膜厚度(63.72±14.00)μm与对照组(77.76±14.90)μm相比,增生明显减少(P<0.05)。增殖指数对照组(29.30±7.15)明显高于干预组(20.10±9.48)(P<0.05)。在干预组和对照组均有阳性PCNA免疫组化染色表达细胞,正常静脉未见阳性表达,对照组较干预组细胞的阳性表达更强(P<0.05)。P27~(kipl)免疫组化染色干预组见阳性表达细胞,对照组表达阴性(P<0.05)。干预组血管壁术后1～8周均可测到雷帕霉素,含量呈逐步递减趋势。结论血管周围局部应用雷帕霉素具有抑制兔移植静脉内膜过度增殖的作用;这种作用和P27~(kipl)的上调表达有关。     

Rapamycin-loaded nanoparticles for inhibition of neointimal hyperplasia in experimental vein grafts

Background

To report our experience, with Deep mediastinal wound infections (DMWI). Emphasis was given to the management of deep infections with omental flaps

Methods

From February 2000 to October 2007, out of 3896 cardiac surgery patients (prospective data collection) 120 pts (3.02%) developed sternal wound infections. There were 104 males & 16 females; (73.7%) CABG, (13.5%) Valves & (9.32%) CABG and Valve.

Results

Superficial sternal wound infection detected in 68 patients (1.75%) and fifty-two patients (1.34%) developed DMWI. The incremental risk factors for development of DMWI were: Diabetes (OR = 3.62, CI = 1.2-10.98), Pre Op Creatinine > 200 μmol/l (OR = 3.33, CI = 1.14-9.7) and Prolong ventilation (OR = 4.16, CI = 1.73-9.98). Overall mortality for the DMWI was 9.3% and the specific mortality of the omental flap group was 8.3%. 19% of the "DMWI group", developed complications: hematoma 6%, partial flap loss 3.0%, wound dehiscence 5.3%. Mean Hospital Stay: 59 ± 21.5 days.

Conclusion

Post cardiac surgery sternal wound complications remain challenging. The role of multidisciplinary approach is fundamental, as is the importance of an aggressive early wound exploration especially for deep sternal infections.