羟基磷灰石在硬组织替代材料中的复合与组装

本介绍了硬组织替代材料复合方法从机械共混到超微结构自组装的不断发展过程，同时阐明了羟基磷灰石在人工硬组织替代材料复合中所扮演的重要角色。     

人体硬组织替代材料表面对血浆蛋白的吸附研究

本文研究了四种人体硬组织替代材料对三种血浆蛋白的吸附情况，发现材料吸附蛋白的多少是由材料的性质的蛋白质的种类决定的，并有一定规律性。其中生物玻璃陶瓷的吸附最强。钛合金最弱，球蛋白最易被吸附。     

羟基磷灰石生物陶瓷及涂层制备技术的研究进展

羟基磷灰石 (HA)具有较好的生物相容性和生物活性 ,而其涂层材料可作为生物硬组织替代材料 ,有很好的发展前景。对羟基磷灰石及其涂层材料的制备方法作综合介绍 ,并提出一些存在的问题和解决方法。     

输尿管细胞外基质修复输尿管缺损的实验研究

为了寻求理想的输尿管替代材料 ,采用生化方法制备了一种新型的组织工程材料细胞外基质 (Extra-cellular Matrix ,ECM) ,并用于替代同种异体输尿管缺损 ,结果表明 ECM很好的促进了缺损组织的再生 ,替代术后 16周再生组织的形态与功能已与正常组织无明显差异。异体输尿管细胞外基质是一种理想的输尿管替代材料     

复合抗肿瘤珊瑚羟基磷灰石人工骨的体内成骨

背景：复合抗肿瘤珊瑚羟基磷灰石人工骨在体内外有良好的缓释效果及抗肿瘤作用,但由于其所复合药物量较大,植入体内骨缺损处较高的局部药物浓度是否影响骨的正常诱导、传导及生长？ 目的：建立复合抗肿瘤珊瑚羟基磷灰石人工骨成骨模型,进一步分析复合抗肿瘤珊瑚羟基磷灰石人工骨的体内成骨效应及规律。 方法：分别将珊瑚羟基磷灰石人工骨及复合抗肿瘤珊瑚羟基磷灰石人工骨植入兔股骨两干骺端骨缺损模型,定期观察股骨X射线影像,并取材行组织病理切片,观察材料降解和被新骨替代的速度、骨与材料界面的结合情况,材料内部新骨生长情况。 结果与结论：珊瑚羟基磷灰石人工骨植入后与周围骨形成组织及骨桥连接较复合抗肿瘤珊瑚羟基磷灰石人工骨快,植入4周后X射线片影像及组织切片示珊瑚羟基磷灰石人工骨边缘开始逐渐不清,并逐步与动物骨形成骨愈合。复合抗肿瘤珊瑚羟基磷灰石人工骨植入后早期8周内局部以抑制组织细胞生长为主,6~12周逐渐有组织结构向材料孔隙内生长且逐渐出现成骨细胞、骨基质及骨细胞,新生骨逐渐生长替代融合,26周左右与周围骨形成骨愈合。说明复合抗肿瘤珊瑚羟基磷灰石人工骨植入早期虽对骨愈合有一定的抑制作用,但最终仍可自行与周围骨缺损达到骨愈合。     

针对组织工程多孔生物陶瓷的组织学技术优化探讨

目的 改进硬组织切片技术以适应生物陶瓷材料在骨组织工程中的研究.方法 探索硬组织切片的厚度、漂片温度、裱片方法、烤片温度和时间的最佳组合,针对阳离子防脱载玻片的使用条件进行反复比较,通过改进操作流程中的关键技术和需避免的问题,摸索出阳离子载玻片在硬组织切片裱片中的最佳应用条件,克服了硬组织切片制作技术中标本易破碎、切片易脱落及染色时染料容易吸附的缺点.结果 通过技术探索与改进,生物陶瓷支架材料体内植入后的类骨修复体标本的硬组织切片能保持其杂化后的组织结构与比较完整的材料结构,可进行Masson三色染色、苏木精-伊红(HE)及甲苯胺蓝染色.染色后镜下观察显示支架内杂化生长的组织结构完整、细胞形态清晰、切片质量好、生物陶瓷支架脱片少.荧光显微镜可观察到类骨修复体钙沉积现象完整.结论 改善了传统硬组织切片技术处理生物陶瓷材料时易于破坏组织-材料结构的缺点.改进的硬组织切片技术适应生物陶瓷材料在骨组织工程领域研究.     

羟基磷灰石基人工骨的研究进展

目的研究羟基磷灰石基人工骨作为最有发展前途的生物硬组织替代材料之一,在生物医用材料和医学研究领域的应用.方法制备具有良好生物相容性、力学性能、骨诱导性与治疗功能的羟基磷灰石基人工骨,用于人体骨组织的缺失的修复,及相关疾病的治疗.结果通过制备性能优良的羟基磷灰石粉体,结合纳米技术、组织工程技术和生物技术将不同材料通过合适的方法组合成羟基磷灰石人工骨,从而获得良好的临床应用性能.结论从临床角度,综合了国内外近十年相关文献的基础上,评述了羟基磷灰石人工骨的研究进展.     

超临界流体技术合成的复合型骨替代生物材料:体内外生物学评价

背景:在复合材料内部增加细胞黏附性较好的高分子材料或同骨组织羟基磷灰石成分相似的无机材料,可以改善材料的表面化学结构。过去的十几年,产生和发展了许多合成生物降解支架材料的新技术,虽然超临界流体技术应用在合成支架中时间尚短,但有着其他技术不可比拟的众多优点,目前越发受到学者的重视。目的:以聚乳酸和同种异体骨粉为原材料,通过超临界流体技术合成复合型骨替代生物材料,评价其生物学特性。方法:首先将同种异体皮质骨粉与聚乳酸在超临界二氧化碳作用下合成多孔复合型骨生物替代材料。将材料浸提液与成骨细胞系复合培养,体外观察细胞形态、增殖情况;通过材料浸提液皮内注射实验和材料肌袋内埋入实验,体内观察动物的致敏、组织炎症发生情况。结果与结论:体外大体观察该种复合材料形状、大小、孔隙可控,孔径适中,有较好的硬度,体外实验表明细胞相容性良好,对细胞的增殖无毒副作用;体内实验表明材料植入动物体内未发生致敏反应,组织相容性良好,但无异位成骨作用。说明制备的新型复合骨组织生物材料在细胞学和生物相容性检测上可以满足组织工程支架和骨组织替代的要求,该种合成技术及多孔生物材料有广阔发展前景。     

羟基磷灰石基人工骨的研究进展

目的 研究羟基磷灰石基人工骨作为最有发展前途的生物硬组织替代材料之一，在生物医用材料和医学研究领域的应用。方法制备具有良好生物相容性、力学性能、骨诱导性与治疗功能的羟基磷灰石基人工骨，用于人体骨组织的缺失的修复，及相关疾病的治疗。结果通过制备性能优良的羟基磷灰石粉体，结合纳米技术、组织工程技术和生物技术将不同材料通过合适的方法组合成羟摹磷灰石人工骨，从而获得良好的临床应用性能。结论从临床角度，综合了国内外近十年相关文献的基础上，评述了羟基磷灰石人工骨的研究进展。     

生物硬组织材料力学研究方法进展

研究生物硬组织材料的力学性质对于预防和治疗骨科和口腔疾病具有重要意义。同时,经过长期的进化,生物材料具有独特的力学性质,研究这些材料的结构与力学性质可以为工程材料的设计提供解决方案。与工程材料不同,生物材料的力学研究需要采用特殊的方法来准确描述其力学性质。本文针对生物硬组织材料力学性质的研究方法进行综述,包括生物硬组织材料的常规力学实验方法、断裂力学和压痕测试技术,以及微观和宏观力学数值模拟技术。     

Changes in the Metabolic Activity of Neurons in the Anterior Hypothalamic Nuclei in Rats during Hyperthermia,Fever, and Hypothermia

Histochemical methods were used to detect differently directed changes in the metabolic activity of neurons in the anterior hypothalamic nuclei in rats during hyperthermia, fever, and hypothermia. Hyperthermia induced by high temperatures was associated with increases in the activities of enzymes involved in energy metabolism, with increases in RNA contents in neurons in the supraoptic, paraventricular, and median preoptic nuclei of the anterior hypothalamus of the rat, which is evidence for increases in metabolic activity in the neurons of these nuclei. Endotoxin-induced fever was accompanied by decreases in the metabolic activity of neurons in the median preoptic nucleus, while activity in neurons of the supraoptic and paraventricular nuclei showed no significant change. The development of hypothermia induced by low temperatures was characterized by decreases in the metabolic activity of neurons in the supraoptic, paraventricular, and median preoptic nuclei of the anterior hypothalamus. It is suggested that the differently directed changes in metabolic activity in the neurons of the anterior hypothalamus in hyperthermia, fever, and hypothermia are associated with their roles in the central mechanisms of thermoregulation (median preoptic nucleus) and neurosecretory processes (supraoptic and paraventricular nuclei).     

哺乳动物垂体后叶比较化学神经解剖学Ⅰ.P物质免疫反应神经纤维在人、猴、狗、猫及大鼠垂体后叶的分布比较

垂体后叶是重要的神经内分泌器官。对于垂体后叶的形态和功能研究是神经科学研究的热门课题。但以往对垂体后叶的研究大都是以大鼠、兔等低等动物为材料，而动物种间的差异很大。仅以大鼠等啮齿动物的资料为根据难以得出全面的解释。为此，作者对包括人、恒河猴在内的多种哺乳动物的垂体后叶内13种神经活性物质的分布进行了比较研究，得到了较为全面的资料。还发现2种新的神经纤维也存在于哺乳动物垂体后叶。本文用免疫组织化学方法证明了P物质免疫反应神经纤维不但存在于大鼠垂体后叶，也存在于人、猴、狗和猫的垂体后叶。比较五种动物垂体后叶P物质免疫反应神经纤维的密度，以狗垂体后叶为最高，人和大鼠次之，猴垂体有稀疏的分布，猫垂体后叶密度最低。在人和猴垂体后叶，P物质免疫反应神经纤维主要分布在垂体柄、神经叶的中央部和腹后部，其它部位仅见散在纤维。在狗垂体后叶背部和漏斗壁可见非常密集的纤维网，腹后部仅见中等密度P物质阳性纤维。猫漏斗壁的纤维束为中等密度，并沿漏斗隐窝壁直达漏斗隐窝底壁，其它部位仅见稀少的阳性纤维。大鼠垂体后叶周边部纤维密度高于中央区，吻侧端又稍多于尾侧端。     

Comparison of lipid peroxidation parameters in the heart,liver, and brain of rats with different degrees of resistance to hypoxia

The relationship between the intensity of lipid peroxidation and the activity of the antioxidant system in the heart, liver, and brain is studied in male Wistar rats with low and high resistance to hypoxia tested by being “raised” to an altitude of 11.5 km and in intact outbred rats. It is found that in all groups of rats the content of lipid peroxidation products is highest in the liver, lower in the heart, and lowest in the brain. In all groups, the rate of the ascorbate-induced lipid peroxidation is highest in the brain, lower in the liver, and lowest in the heart. The activity of the antioxidant system is highest in the brain, lower in the liver, and lowest in the heart of low-resistance and outbred rats, while in high-resistance rats it is the same in all the organs. Thus, the difference in the parameters of lipid peroxidation and, particularly, of the antioxidant system in the studied organs is most pronounced in rats with a low resistance to hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 138–143, February, 1996 Presented by A. I. Archakov, Member of the Russian Academy of Medical Sciences     

Effects of thyroid hormone deficiency on behavior in rat strains with different predisposition to catalepsy

The effects of thyroidectomy on anxiety-related behavior in the elevated plus-maze test, locomotor activity, and defecation in the open-field test and duration of cataleptic freezing were studied in rats of two strains differing in predisposition to catalepsy: cataleptic strain GC and its ancestor strain Wistar. Total thyroxine level was significantly decreased in control GC rats compared to that in control Wistar rats. Control Wistar and GC rats did not differ either in the percentages of open-arm entries or the time spent therein in the elevated plus-maze test or in defecation score in the open-field test. At the same time, control Wistar rats showed more locomotor activity compared to control GC rats in the open-field test. Thyroid hormone deficiency did not affect the percentages of open-arm entries and the time spent therein in the elevated plus-maze test as well as defecation score in both strains. Thyroidectomy did not alter significantly locomotor activity in Wistar rats, but produced a nearly twofold increase in locomotor activity in GC rats. The most important finding is that thyroidectomy significantly increased the expression of catalepsy in Wistar rats, which points to a role of thyroid hormones in the regulation of predisposition to cataleptic reaction.     

Type 1 metalloproteinase is selectively expressed in adult rat brain and can be rapidly up-regulated by kainate

The expression of metalloproteinase MMP-1 was traced in frontal sections of the rat brain in normal conditions and 4 h after an intraperitoneal injection of kainate. In the olfactory lobe, immunoreactivity was normally detected in the lateral olfactory tract. Kainate treatment led to the appearance of additional immunoreactivity in the neuropilar tracts. In the hippocampal part of brain, immunoreactive neurons were found exclusively after the kainate treatment in several hypothalamic and amygdalar nuclei, and in the restricted cortex areas (clusters of neurons in layers 3–4 of cortex, and a stripe of cells in layer 6). In the area between the hippocampus and cerebellum, MMP-1-like immunoreactivity was normally present in the entorhinal cortex, in the lateral periaqueductal gray, and in the pontine nucleus. After kainate treatment, the immunoreactive neurons were also found in the medial entorhinal cortex and in the dorsal raphe nucleus. In the brain stem, the immunoreactive cells were normally found in six nuclei. After kainate treatment, additional immunoreactivity appeared in the inferior olive neurons and in tracts supplying the cerebellar cortex. Thus, MMP-1 is present in several brain areas in normal conditions at a detectable level, and its expression increases after kainate-induced seizures.     

Glicentin-immunoreactive perikarya and varicosities in the guinea pig central nervous system

Glicentin-immunoreactive (GLI-IR) neurons and nerves were studied in the central nervous system of guinea pig. GLI-IR perikarya were found in the medulla oblongata located in the nucleus tractus solitarii, in the nucleus commissuralis, in the nucleus reticularis lateralis and the formatio reticularis. Immunoreactive varicosities, however, were seen in many other areas of the central nervous system such as in the hypothalamus, in the nucleus proprius striae terminalis, in the nuclei thalami mediani, in the substantia grisea centralis, in the nuclei raphe, in the formatio reticularis and in the vagus nucleus tractus solitarii-system. Some of the described GLI-IR varicosities may therefore be extensions of the neurons located in the medulla oblongata. Furthermore, the role of GLI as a putative neurotransmitter is discussed.     

Isochronic transplantation of neonatal grafts in the visual cortex of cats: responsiveness,ocular dominance and specificity of cortical cells to visual stimulation

Summary The visual cortex of adult cats was studied physiologically following neonatal isochronic transplantation of grafts from areas 17,18, which were placed homotopically, in order to reveal their functional integration and thus possible repairing of damaged cortical neuronal circuits. Three homograft cats, in which transplantation was carried out between siblings (228 cortical cells) were compared to 4 animals receiving reimplanted autografts of the equivalent size (131 cells) as well as 3 animals with analogous sectioning of the visual cortex (162 cells) (pseudograft controls). The location of the boundaries between the transplant region and the host were determined using the Nissl's method for staining histological cross sections. Extracellular unit recording revealed typical waveform of the action potentials in the transplanted region and in the surrounding host tissue of all groups of cats. Visual responsiveness in the homograft cats was 17.5% in the transplanted region and 80.4% in the unoperated hemisphere; the corresponding results were 40.3% for the transplanted region and 82.2% for the unoperated hemisphere in the autografts and 23.1% and 73.4% in the pseudografts. The specificity of the cells to visual stimulation as expressed by their orientation and direction specificity, indicated preservation of these properties in the transplanted cats. While all responsive cells in the transplanted region of the homografts were orientation specific, their proportion was 60% in the autografts and 55.5% in the analogous region in the pseudograft controls. As to the direction specific cells, their performance in the grafted region of the grafted cats was even much higher than that of the pseudograft controls. The ocular dominance distribution of the cells showed preservation of binocularity in the transplanted region (90.0% binocular cells) of the homografts; it was however smaller in the equivalent region of the autografts (65.0%) and remarkably reduced (20.0%) in the pseudografts. It was concluded that despite the deafferentation induced during the transplantation procedure, a remarkable visual responsiveness was found in the transplanted region, indicating postoperative recovery. However, the cells there were mainly affected in their activity and less in their specificity to visual stimulation.     

Anterograde tracer and field potential analysis of the neocortical layer I projection from nucleus ventralis medialis of the thalamus in cat

The projection of the ventromedial nucleus of the thalamus to the neocortex was studied in cat by means of anterograde and retrograde transport of horseradish peroxidase, by the depth profile of evoked thalamocortical field potentials, and by superfusion of the cortex with manganese to block transmitter release. Horseradish peroxidase injected into the ventromedial nucleus was anterogradely transported to the outer third of layer I in the neocortex, extending from the depth of the cruciate sulcus anterior to the olfactory bulb and tract. The region of projection from the ventromedial nucleus extended mediolaterally from the medial wall of the proreus gyrus to the ventral tip of the coronal gyrus. Horseradish peroxidase injections or applications in these areas of the neocortex resulted in the retrograde labeling of neurons in the ventromedial nucleus. Injections in many other cortical areas did not result in labeled neurons in this nucleus. Stimulation of the ventromedial nucleus with single pulses elicited surface-negative waves in the medial part of the precruciate region that had superficial isoelectric points. Superfusion of the precruciate area with manganese resulted in the suppression of the ventromedial-evoked wave, whereas control extracellular waves in deeper layers were unaffected. An additional additional finding was that horseradish peroxidase injections in the ventromedial nucleus led to a dense reciprocal retrograde labeling of neurons in layer VI of that part of the cortex to which the ventromedial nucleus projects. We conclude that, in cat, (1) the ventromedial nucleus projects to layer I of the cerebral cortex anterior to the cruciate sulcus and receives a dense reciprocal projection from layer VI; (2) stimulation of neurons in the ventromedial nucleus causes depolarization of structures in layer I and these neurons are responsible for recruiting responses in the anterior cortex.     

Pentylenetetrazol kindling in rats: Is neurodegeneration associated with manifestations of convulsive activity?

Structural changes in neurons and measures of oxidative stress were studied in the hippocampus of rats tolerant (ST) and sensitive (SS) to developing clonic-tonic seizures in conditions of pentylenetetrazol kindling. Sequences of 11 injections of pentylenetetrazol significantly decreased the number of normal neurons in hippocampal field CA1 in SS rats, this effect being seen in both hippocampal field CA1 and the dentate fascia in ST rats. Decreases in the numbers of normal neurons were accompanied by increases in the numbers of damaged cells in field CA4 in rats of both groups. After 21 injections, decreases in the numbers of normal neurons were seen in field CA1 in both SS and ST rats, while the numbers of damaged neurons were significantly greater than control only in ST rats in fields CA1 and CA4. The glutathione level was significantly lower in the hippocampus in both groups of rats than in controls. Thus, rats “ tolerant” to developing convulsions show signs of oxidative stress and neurodegenerative changes in the hippocampus. This suggests that oxidative neuron damage leading to neurodegeneration in the pentylenetetrazol kindling model is not directly associated with convulsive activity. __________ Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 91, No. 7, pp. 764–775, July, 2005.