碳纳米管/羟基磷灰石复合材料兔胫骨生物相容性研究

目的：探讨不同比例碳纳米管/羟基磷灰石纳米复合材料兔胫骨的生物相容性.方法：将碳纳米管含量为2%和3%的碳纳米管/羟基磷灰石复合材料置入兔右侧胫骨的缺损处,在1周～12周分别进行x线检查、组织学检查及分子生物学分析.结果：不同碳纳米管含量的复合材料均能诱导成骨,无排斥反应.X线片、组织学检查、分子生物学检查均无明显差别.结论：碳纳米管/羟基磷灰石材料有良好的骨相容性.     

腮腺癌中血管内皮生长因子和血管内皮生长因子受体3表达与淋巴结转移

目的:研究血管内皮生长因子C及受体3(VEGF-C、VEGFR-3)在腮腺癌中的表达及其与淋巴结转移的关系。方法:采用免疫组织化学SP法检测62例腮腺癌标本组织中VEGF-C、VEGFR-3的表达,并计算其阳性表达率。结果:VEGF-C、VEGFR-3在腮腺癌中显著表达,其阳性率分别是51.6%、48.4%,与淋巴结转移密切相关。结论:VEGF-C、VEGFR-3与淋巴结转移有相关性,为肿瘤细胞淋巴道转移提供了条件,可以作为判断腮腺癌患者预后的一个重要指标。     

血管内皮生长因子及其受体在子宫内膜癌中的表达

目的探讨血管内皮生长因子(VEGF)及其受体fms样酪氨酸受体-1 (flt-1)和含插入区的激酶受体(KDR)在子宫内膜癌血管生成中的作用及其与内膜癌分化程度的关系.方法采用免疫组织化学及原位杂交方法对23例子宫内膜癌及6例正常绝经期子宫内膜中VEGF、flt-1、KDR蛋白质及其mRNA进行检测,并对少数病例行Western印迹分析,以检测VEGF亚型在内膜癌组织的分布,用内皮细胞标志Ⅷ因子标记内膜癌组织中的微血管密度.结果 VEGF、flt-1、KDR蛋白质及其mRNA主要分布在子宫内膜癌组织血管内皮细胞及癌细胞胞质内.VEGF蛋白质在中分化(G2)、低分化(G3)内膜癌血管内皮细胞及癌细胞上的表达高于高分化内膜癌(G1)及正常绝经期子宫内膜(P<0.05), VEGF mRNA在不同分化程度内膜癌组织的表达差异无显著性意义(P>0.05),但均大于正常绝经期子宫内膜(P<0.05);flt-1蛋白质及flt-1mRNA在G3内膜癌血管内皮细胞的表达高于G1、G2及正常绝经期子宫内膜(P<0.05),在癌细胞的表达差异无显著性意义(P>0.05) ,但均高于正常绝经期子宫内膜(P<0.05);KDR蛋白质在子宫内膜癌组织血管内皮细胞及癌细胞上的表达较强,但不随分化程度发生变化,其mRNA在中分化(G2)、低分化(G3)内膜癌血管内皮细胞及癌细胞上的表达高于正常绝经期子宫内膜(P<0.05).G3子宫内膜癌组织的血管密度(48个±12个)高于G1(27个±14个)、G2(26个±16个)及正常绝经期子宫内膜(26个±11个,P<0.05).结论 VEGF、flt-1、KDR及mRNA在子宫内膜癌中的表达形式提示其与癌组织血管生成及血管通透性相关,VEGF及其受体是与子宫内膜癌旺盛生长相关的因子之一.     

血管内皮生长因子C及血管内皮生长因子受体3在人直肠腺癌中的表达及其意义

目的:检测血管内皮生长因子C(VEGF-C)及血管内皮生长因子受体3(VEGFR-3)在人直肠癌组织和淋巴结中的表达,探讨VEGF-C在人直肠癌发生、发展和淋巴结转移中的作用.方法:选用31例手术切除并经病理切片确诊为直肠腺癌的癌组织石蜡标本,采用免疫组织化学方法检测VEGF-C及VEGFR-3在癌组织和淋巴结内的表达.结果:在31例直肠腺癌组织的癌细胞质中,VEGF-C显色阳性者54.8%;VEGFR-3显色阳性者64.5%;在14例淋巴结中,VEGF-C显色阳性者71.4%;VEGFR-3显色阳性者64.3%.结论:VEGF-C和VEGFR-3在直肠癌组织和淋巴结中均有较高表达,VEGF-C通过与VEGFR-3结合,促使淋巴管内皮细胞增殖、迁移并形成新的淋巴管,导致癌细胞转移.     

血管内皮生长因子受体在膀胱癌中的表达及临床意义

目的：探讨血管内皮生长因子受体在膀胱癌中的表达及与临床病理因素的相关性。方法：免疫组化法采用链霉菌抗生物素一过氧化物酶连接法(SP法)对50例膀胱癌标本，20例正常膀胱组织标本中血管内皮生长因子受体的表达进行检测。结果：血管内皮生长因子受体在大多数膀胱癌组织中表达(74％)，而且其表达水平与病理分期及组织分级呈正相关。在正常膀胱组织中无1例表达(0％)。结论：膀胱癌组织中血管内皮生长因子受体阳性表达，提示其在膀胱癌的血管生成中起着重要作用。     

碳纳米管/羟基磷灰石生物复合材料的研究初探

目的 本文主要对碳纳米管／羟基磷灰石生物复合材料进行了初步研究。力争初步找到一条制备CNTs／HAp复合材料的工艺路线，并对所得复合材料的微观结构进行初步研究。方法以球磨和超声分散两种工艺制备了CNTs／HAp复合粉体，并经等静压成型、真空无压烧结制备出了碳纳米管／羟基磷灰石复合材料。结果XRD、IR、TEM及SEM研究发现，所制备羟基磷灰石为纳米级，纯度高，所使用的原料碳纳米管纯度高，碳纳米管在复合粉体中分散均匀。碳纳米管有细化晶粒的作用，但随着烧结温度的升高碳纳米管分解加剧，因此烧结温度以低于1100℃为宜。结论初步找到了一条制备CNTs／HAp复合材料的工艺路线。随温度的升高，复合材料中CNTs的存留量逐渐减少。因此真空下该复合材料的烧结温度应低于1100℃。     

血管内皮生长因子及其受体在肝癌细胞中的表达及意义

目的 探讨人肝癌细胞株血管内皮生长因子（VEGF）及其受体的表达,进一步认识VEGF在肝癌血管形成中的作用机制,方法 以人脐静脉血管内皮细胞系ECV304和小鼠成纤维细胞系L929作为对照,采用免疫组化染色及RT-PCR,检测体外培养的人肝细胞肝癌细胞系SMMC7721、HHCC和HepG2中VEGF及其受体的表达。结果 SMMC7721、HHCC和HepG2细胞均有VEGF的表达。同时VEGF受体1（Flt-1)在SMMC7721细胞中也有表达;而HHCC和HepG2细胞则表达VEGF的受体2（KDR）。结论 在肝癌的血管形成中可能存在VEGF的自分泌机制。     

血管内皮生长因子及其受体flt-1在宫颈癌中的表达和意义

我们拟通过观察血管内皮生长因子 (ＶＥＧＦ)与其受体ｆｌｔ 1在宫颈癌中的表达 ,探讨其与宫颈癌的生长、浸润、转移的关系 ,及其在间质血管生成中的作用和相互关系。一、材料和方法收集 1998年 9月至 2 0 0 0年 8月白求恩医科大学第一、二临床学院及吉林省肿瘤医院手术切除宫颈癌标本 72例 ,慢性宫颈炎 6例 ,患者术前均未经任何抗癌治疗 ,确诊为宫颈癌 ,其中腺癌 7例 ,鳞癌 6 5例。患者平均年龄 45岁 ,最大为 5 6岁 ,最小为 2 7岁。组织经常规石蜡包埋后做 4μｍ连续切片 ,行ＨＥ和免疫组织化学链霉素抗生物素 过氧化酶 (ＳＰ)法染色。一…     

血管内皮生长因子及其受体在子宫内膜异位症中的表达和意义

目的:研究血管内皮生长因子(Vascular endothelial growth factor,VEGF)及其受体(Vascular endothelial growth factor receptor1,VEGFR1)在子宫内膜异位症(内异症)患者子宫在位内膜、异位内膜及正常对照组内膜组织中的表达,探讨其在子宫内膜异位症中的作用机制.方法:采用免疫组织化学及Western blot方法检测34例异位症患者在位内膜、异位内膜(内异症组)及34例正常内膜(对照组)组织中VEGF及其受体VEGFR1蛋白的定位及表达.结果:异症组在位及异位子宫内膜组织腺上皮细胞及间质细胞中均有VEGF及VEGFR1蛋白表达,且均高于同期对照组内膜,差异有统计学意义;对照组分泌期内膜VEGF及VEGFR1蛋白表达高于增生期,呈现周期性变化,而内异症组在位及异位内膜VEGF及VEGFR1蛋白表达失去周期性变化,分泌期与增生期均高表达,差异无统计学意义.Western blot检测结果与免疫组化结果一致.结论:内异症患者在位及异位内膜组织中VEGF、VEGFR1蛋白高表达可能与内异症的发生发展有关.     

血管内皮生长因子及其可溶性血管内皮生长因子受体-1水平与胎儿出生体重

目的本研究通过对比血管内皮生长因子(VEGF)、可溶性血管内皮生长因子受体-1(sFlt-1)水平差异与新生儿出生体重的关系,以探讨其在胎儿出生体重发生中的作用。方法采用免疫组织化学法检测40例分娩正常出生体重儿组(AGA组)、30例高出生体重儿组(LGA组)及30例低出生体重儿组(SGA组)胎盘组织中VEGF、sFlt-1的表达水平。结果①LGA组胎盘组织中VEGF的表达高于AGA组,sFlt-1的表达水平低于AGA组,差异有统计学意义(χ2=21.17,P<0.01)。SGA组胎盘组织中VEGF的表达低于AGA组,sFlt-1的表达水平高于AGA组,差异有统计学意义(χ2=8.44,P=0.04)。②胎盘组织中VEGF的表达水平与胎儿出生体重呈正相关(r=0.427,P<0.01),胎盘组织中sFlt-1的表达水平与胎儿出生体重呈负相关(r=-0.569,P<0.01)。结论孕妇胎盘组织中VEGF及sFlt-1表达水平的变化可能与胎儿出生体重有关。     

置铜宫内节育器子宫内膜VEGF受体KDR及VEGF mRNA的表达

目的探讨置CuIUD引起的子宫出血是否与VEGF蛋白、VEGF受体KDR、VEGF mRNA表达的相关性。方法收集要求取CuIUD者60例分为3组,TCuIUD出血组、OCuIUD出血组、无出血组各20例,与未置器组10例对照,诊刮术采取子宫内膜,用免疫组化法检测子宫内膜中VEGF蛋白、VEGF受体KDR的表达,用免疫杂交法检测VEGF mRNA的表达。结果置TCuIUD出血组和OCuIUD出血组与无出血组比较,VEGF蛋白表达增加,分别为0.469±0.183,0.396±0.098,高于0.213±0.079,差异有显著性(P<0.05=;置TCuIUD出血组和OCuIUD出血组与无出血组对比,VEGF受体KDR的表达明显增加,分别为0.329±0.063,0.337±0.108,高于0.192±0.053,差异有显著性(P<0.05=。置TCuIUD出血组与OCuIUD出血组比较,VEGFmRNA的表达升高,TCuIUD出血组和OCuIUD组分别为0.694±0.238,0.377±0.169,差异有显著性(P<0.05=。结论VEGF、VEGF受体KDR的表达参与了置CuIUD引起的子宫出血,CuI-UD对子宫内膜的压迫、损伤作用可能与VEGFmRNA的表达间存在量化关系。     

Postnatal development of parvalbumin immunoreactivity in striated muscles of the rat

The presence of parvalbumin, a calcium-binding protein, has been correlated with the maturation of locomotor activity in developing striated muscle. In the present study, postnatal parvalbumin immunoreactivity is examined in the tibialis anterior, intercostal, diaphragm and intrinsic muscles of the tongue of the rat to gather a better understanding of the different developmental patterns. Parvalbumin immunoreactivity appears in the anterior tibialis muscle by day 4, and reaches an adult checkerboard pattern 2 days later. In contrast, parvalbumin immunoreactivity in the intrinsic muscles of the tongue, and in diaphragm and intercostal muscles, which are active near birth, does not appear until the 2nd week. Therefore, these features suggest that parvalbumin immunoreaction is not exclusively dependent on functional activity. In addition, the finding that differences in parvalbumin expression do not correlate in time with the differentiation of fiber types as judged by myosin ATPase activity, suggests that myosin and parvalbumin might be regulated by different mechanisms.     

The importance of frequency and amount of electrical stimulation for contractile properties of denervated rat muscles

Soleus (SOL) and extensor digitorum longus (EDL) muscles were denervated and directly stimulated for 23–69 days through implanted electrodes employing three different patterns. The stimulation was delivered in impulse trains where the pulse frequency differed (20, 75, and 150 Hz), while the train duration (0.3 s) and train repetition rate (1 min^-1) were identical. Consequently, the number of pulses varied such that higher frequency was combined with a higher amount of stimulation. In both SOL and EDL the high-frequency pattern resulted in shorter twitch time-to-peak, greater post-tetanic potentiation, and greater tetanic force than the low frequency. Isotonic shortening velocity was increased to the same extent by all the patterns in SOL whereas in EDL fast intrinsic shortening velocity was maintained by the low-frequency pattern while it was decreased by the high-frequency pattern. We attribute this unexpected effect on the EDL to the larger number of pulses in the high-frequency pattern. By combining the present findings with previous data on directly stimulated rat muscles we conclude: in SOL the twitch duration is influenced by both the frequency and the amount of impulse activity, higher frequencies and smaller amounts leading to faster twitches. The EDL twitch duration is similarly dependent on the amount of activity, but the role of frequency is more unclear. In both SOL and EDL the isotonic shortening velocity is reduced by increasing amounts of activity and there is no evidence that impulse frequency plays a role. In EDL force output is strongly influenced by the impulse frequency, low frequencies resulting in low force outputs irrespective of the amount of activity.     

Effects of cold‐water immersion on VEGF mRNA and protein expression in heart and skeletal muscles of rats

Aim: The effects of cold exposure on gene and protein expression of vascular endothelial growth factor (VEGF), in heart and skeletal muscles, were studied in male adult Wistar rats. Methods: Cold immersion was accomplished by submerging the rats in shoulder‐deep water maintained at ～18 °C, either acutely (1 h) or chronically (1 h day^?1, 5 days week^?1 for 20 weeks). The expressions of VEGF mRNA and protein in heart, gastrocnemius, and soleus muscles were examined by Northern and Western blotting and competitive‐polymerase chain reaction techniques. Results: The expressions of VEGF mRNA and protein were markedly increased in cardiac muscle of the cold‐immersed group, particularly in the 1‐hour exposure group, whereas VEGF mRNA and protein in gastrocnemius were decreased significantly after an acute exposure. Although the protein level in gastrocnemius remained low in the chronically exposed group, the expression of mRNA of VEGF₁₆₅ with chronic exposure in this group returned to the control level and that of VEGF₂₀₆ was 15% greater than that in controls. The expression of mRNA for VEGF₁₆₅ in soleus was also lowered by acute cold exposure, although that for VEGF₂₀₆ was stable. However, VEGF protein was increased by 50%. After 20 weeks, all of these parameters were increased over the levels found in the controls. Conclusion: These results suggest that the VEGF gene may be a major regulatory factor in cardiac and skeletal muscle adaptation to the cold environment stimulating angiogenesis and thermogenesis.     

Androgen replacement therapy improves function in male rat muscles independently of hypertrophy and activation of the Akt/mTOR pathway

Aim: We analysed the effect of physiological doses of androgens following orchidectomy on skeletal muscle and bone of male rats, as well as the relationships between muscle performance, hypertrophy and the Akt/mammalian target of rapamycin (mTOR) signalling pathway involved in the control of anabolic and catabolic muscle metabolism. Methods: We studied the soleus muscle and tibia from intact rats (SHAM), orchidectomized rats treated for 3 months with vehicle (ORX), nandrolone decanoate (NAN) or dihydrotestosterone (DHT). Results: Orchidectomy had very little effect on the soleus muscle. However, maximal force production by soleus muscle (+69%) and fatigue resistance (+35%) in NAN rats were both increased when compared with ORX rats. In contrast, DHT treatment did not improve muscle function. The relative number of muscle fibres expressing slow myosin heavy chain and citrate synthase activity were not different in NAN and ORX rats. Moreover, NAN and DHT treatments did not modify muscle weights and cross‐sectional area of muscle fibres. Furthermore, phosphorylation levels of downstream targets of the Akt/mTOR signalling pathway, Akt, ribosomal protein S6 and eukaryotic initiation factor 4E‐binding protein 1 were similar in muscles of NAN, DHT and ORX rats. In addition, trabecular tibia from NAN and DHT rats displayed higher bone mineral density and bone volume when compared with ORX rats. Only in NAN rats was this associated with increased bone resistance to fracture. Conclusion: Physiological doses of androgens are beneficial to muscle performance in orchidectomized rats without relationship to muscle and fibre hypertrophy and activation of the Akt/mTOR signalling pathway. Taken together our data clearly indicate that the activity of androgens on muscle and bone could participate in the global improvement of musculoskeletal status in the context of androgen deprivation induced by ageing.     

COX-2 expression in DCIS: correlation with VEGF, HER-2/neu, prognostic molecular markers and clinicopathological features

AIMS: There is considerable evidence that links COX-2 to the development of cancer. The aim of our study was to assess, by immunohistochemistry, COX-2 expression in ductal carcinoma in situ (DCIS) and its possible correlation with HER-2/neu, vascular endothelial growth factor (VEGF) expression and other common immunohistochemical parameters (p53, ER, PGR, Ki67). METHODS AND RESULTS: Tissue samples of 49 archival cases of DCIS without any invasive component were analysed for COX-2, HER-2/neu, VEGF, oestrogen and progesterone receptors, Ki67 and p53 by immunohistochemistry using specific antibodies. COX-2 expression was detected in 43 (87.8%) tissue samples, of which 12 (24.5%) were graded as weak, 22 (44.9%) as moderate and nine (8.4%) as high expression. Only six (12.2%) lesions were negative for COX-2 expression. VEGF expression was detected in 93.8% of samples; 66.7% of lesions were found to be positive for HER-2/neu expression. Furthermore, COX-2 expression was significantly correlated with VEGF expression (P = 0.003). A significant positive correlation was also observed between COX-2 and HER-2/neu expression (P < 0.0001). CONCLUSIONS: Our results suggest that COX-2 is highly expressed in DCIS and takes part in the molecular pathway implicated in progression of breast cancer and may provide a rationale for targeting COX-2 in preinvasive breast cancer therapy.     

Effects of anabolic/androgenic steroids on regenerating skeletal muscles in the rat

We have examined the effect of male sexual hormones on the regeneration of skeletal muscles. Degeneration/regeneration of the left soleus and extensor digitorum longus muscles (EDL) of Wistar male rats was induced by an injection of snake venom (2 μg, Notechis scutatus scutatus). During the muscle regeneration (25 days), rats were treated with either oil (CON), nandrolone (NAN), NAN combined with exercise (NAN + EXE) or were castrated (CAS). Muscle growth and myosin heavy chain (MyHC) isoform content of regenerating muscles were studied. Castration altered the concentrations of MyHC in venom-treated EDL (P < 0.01) and soleus (P < 0.05). NAN increased the mass (P < 0.01) of regenerating soleus and decreased the relative amount of fast MyHC protein (% of total, P < 0.05). The effect of NAN + EXE on the fast MyHC proteins of venom-treated soleus was opposite (P < 0.05). NAN and NAN + EXE were without effect on the regenerating EDL (P > 0.05). In conclusion, it is possible that male sexual hormones play a role in the growth (synthesis of contractile proteins) of regenerating muscles in rat. In addition, contrary to NAN + EXE, NAN could be beneficial to soleus regeneration.     

Myostatin and follistatin expression in skeletal muscles of rats with chronic heart failure

Skeletal muscle abnormalities can contribute to decreased exercise capacity in heart failure. Although muscle atrophy is a common alteration in heart failure, the mechanisms responsible for muscle mass reduction are not clear. Myostatin, a member of TGF-β family (transforming growth factor), regulates muscle growth and mass. Several studies have shown a negative correlation between myostatin expression and muscle mass. The aim of this study was to evaluate myostatin expression in skeletal muscles of rats with heart failure. As myostatin gene expression can be modulated by follistatin, we also evaluated its expression. Heart failure was induced by myocardial infarction (MI, n  = 10); results were compared to Sham-operated group ( n  = 10). Ventricular function was assessed by echocardiogram. Gene expression was analyzed by real-time PCR and protein levels by Western blotting in the soleus and gastrocnemius muscles; fibre trophism was evaluated by morphometric analysis. MI group presented heart failure evidence such as pleural effusion and right ventricular hypertrophy. Left ventricular dilation and dysfunction were observed in MI group. In the soleus muscle, cross-sectional area ( P  = 0.006) and follistatin protein levels (Sham 1.00 ± 0.36; MI 0.18 ± 0.06 arbitrary units; P  = 0.03) were lower in MI and there was a trend for follistatin gene expression to be lower in MI group ( P  = 0.085). There was no change in myostatin expression between groups. In gastrocnemius, all MI group parameters were statistically similar to the Sham. In conclusion, our data show that during chronic heart failure, decreased skeletal muscle trophism is combined with unchanged myostatin and reduced follistatin expression.