钛基表面纳米银复合涂层体外抗菌活性及生物安全性评价

背景:羟基磷灰石是骨的主要成分,具有诱导成骨细胞的功能。纳米银具有广谱和高效的抗菌效果,钛基表面羟基磷灰石/纳米银复合涂层材料既有生物活性又具有抗菌特性。目的:研究钛基表面羟基磷灰石/纳米银复合涂层体外抗菌作用及影响因素,评价钛基表面羟基磷灰石/纳米银复合涂层的生物相容性和安全性。方法:选取浓度0,0.5,1.0 mmol/L银溶液制备钛基表面沉积的羟基磷灰石/纳米银复合涂层样品,将其浸提液与金黄色葡萄球菌与材料共培养,进行体外抗菌定性分析。按照国家和国际标准化组织对生物材料相容性检测标准,对健康成年昆明小鼠、新西兰兔进行热原试验、溶血试验、急性毒性试验、皮肤刺激试验,综合评价材料的生物相容性和安全性。结果与结论:钛基表面沉积制备的羟基磷灰石/纳米银复合涂层材料体外对金黄色葡萄球菌有明显抗菌作用,复合材料中银含量越高抗菌作用越明显,且动物实验中未出现明显的热原反应、溶血反应、急性毒性反应、皮肤刺激反应,与不含银的纯羟基磷灰石材料相比,生物相容性差异无显著性意义。说明钛基表面沉积制备的羟基磷灰石/纳米银复合材料,体外对金黄色葡萄球菌具有良好的抗菌作用,且具有良好的生物相容性。     

纳米羟基磷灰石/聚酰胺66多孔材料制备和生物安全性初步评价

采用注塑方法，以医用纳米羟基磷灰石僳酰胺66（n-HA／PA66）复合材料为原料，使用专用发泡剂，制备出了一种具有贯通孔，平均孔隙尺寸约为500衄1的多孔材料，并参照GB／T16886和GB／T16175标准方法，对其生物安全性进行了相关评价。细胞毒性试验、致敏试验、热原试验和溶血试验结果表明本研究制备的多孔n-HA／PA66复合材料无细胞毒性、无致敏性、无热原反应，溶血率为0．59％（〈5％），可初步认为n—HA／PA66多孔材料具有良好的生物安全性，可用于骨组织修复。     

纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的生物相容性与体内降解研究

对制备的纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的生物相容性及体内降解情况进行研究,为临床提供实验依据。参照GB/T16886医疗器械生物学评价标准和要求,对纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥进行急性细胞毒性试验、溶血试验、热源试验、急性全身毒性试验及体内植入试验等系列体内外生物学试验研究,以进行有效的生物相容性和安全性评价。纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的溶血率小于国家规定的5%,在体外不引起溶血反应;浸提液注入动物体内后无死亡,活动进食正常;无细胞毒性反应;热原试验动物体温升高均在0.7℃以下,3只兔体温升高值的总数〈1.5℃,无致热作用;材料植入体内初期有轻度炎症反应,随植入时间延长逐渐减轻,材料也逐渐降解吸收。纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥具有良好的生物相容性和降解性能,具有临床开发应用前景。     

纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的生物相容性与体内降解研究

对制备的纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的生物相容性及体内降解情况进行研究,为临床提供实验依据.参照GB/T16886医疗器械生物学评价标准和要求,对纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥进行急性细胞毒性试验、溶血试验、热源试验、急性全身毒性试验及体内植入试验等系列体内外生物学试验研究,以进行有效的生物相容性和安全性评价.纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥的溶血率小于国家规定的5％,在体外不引起溶血反应;浸提液注入动物体内后无死亡,活动进食正常;无细胞毒性反应;热原试验动物体温升高均在0.7℃以下,3只兔体温升高值的总数＜1.5℃,无致热作用;材料植入体内初期有轻度炎症反应,随植入时间延长逐渐减轻,材料也逐渐降解吸收.纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥具有良好的生物相容性和降解性能,具有临床开发应用前景.     

人工气管组分材料胶原蛋白/羟基磷灰石体外细胞毒理学研究

细胞毒性和细胞相容性是生物材料应用于临床所遇到的首要问题。将胶原蛋白作为载体与羟基磷灰石混合制成人工气管的组分材料，通过体外实验研究其细咆毒性和细胞相容性，为临床应用作前期准备。采用体外细胞培养法、MTT比色法评价胶原蛋白和羟基磷灰石复合材料对培养细胞L-929的细胞形态、生长和增殖的影响，同时采用溶血试验评价该复合材料是否对红细咆的功能和代谢产生不良反应。结果显示，胶原蛋白和羟基磷灰石复合材料对体外培养的细胞形态不构成损害，对其生长和增殖无明显抑制作用，细胞毒性为0级；溶血率为1．85％，低于5％的国家标准，在体外不引起溶血反应。实验表明，胶原蛋白和羟基磷灰石复合材料具有良好的细胞相容性，属无毒级生物材料，其作为人工气管组分材料应用于临床具有可行性和安全性。     

聚醚醚酮／羟基磷灰石／碳纤维复合材料的组织相容性初步研究

目的对新型复合材料聚醚醚酮/羟基磷灰石/碳纤维的组织相容性进行综合性评价。方法依据GB/T 16886系列标准,应用大鼠对聚醚醚酮/羟基磷灰石/碳纤维复合材料进行急性全身毒性实验、热原实验、溶血实验及皮内反应实验。结果急性全身毒性实验,各实验组大鼠一般状况良好,各时相体质量变化差异无统计学意义（P﹥0.05）,无急性全身毒性反应,肝肾标本与对照组比较无阳性病理改变;热原实验,各组大鼠在各时间段内测得的体温变化均符合热原实验评价标准;溶血实验,复合材料浸提液的溶血百分率均低于标准规定的5%;皮内反应实验,皮下组织在各时相点水肿极轻微,无红斑形成。结论新型复合材料聚醚醚酮/羟基磷灰石/碳纤维初步研究证明具有良好的组织相容性和安全性。     

纳米羟基磷灰石生物安全性评价与研究进展

国内外大多数研究显示羟基磷灰石具有良好的生物相容性和生物活性,医学领域的运用中,普通羟基磷灰石的缺点是脆性大,有很多研究显示纳米羟基磷灰石有更高的强度和韧性,纳米羟基磷灰石晶体在形态、尺寸、组成、结构和结晶度上与人骨羟基磷灰石晶体高度类似,因此纳米羟皋磷灰石在医学领域的应用也日益广泛。对纳米羟基磷灰石生物安全性的评价不断取得进展,大量研究认为纳米羟苯磷灰石具备生物安全性,但是作为一种新型生物材料,纳米羟基磷灰石在评价标准方面有一些问题。     

PMMA/HA-GF复合材料的体外实验研究

对以无机纤维(GF)增强聚甲基丙烯酸甲酯／羟基磷灰石(PMMA／HA)的复合材料(PDLLA／HA—GF)进行了材料表面结构形貌的观察和体外实验，包括材料的稳定性、体外细胞毒性试验、全身急性毒性试验、过敏试验、溶血试验等。实验结果表明：PMMA／HA-GF复合材料无毒、无过敏刺激性、不引起溶血，具有好的生物相容性。     

纳米含氟羟基磷灰石牙种植体的生物相容性

背景：有关纳米含氟羟基磷灰石牙种植体材料生物相容性的报道较少。 目的：检测纳米含氟羟基磷灰石牙种植体材料的体外生物相容性。 方法：采用溶胶凝胶技术分别制备羟基磷灰石与纳米含氟羟基磷灰石。①溶血性实验：在0.2 mL稀释兔抗凝血中分别加入0.01,0.15,0.2 g/L纳米含氟羟基磷灰石溶液、生理盐水及蒸馏水各10 mL,检测各组上清液吸光度值。②体外细胞毒性实验：分别以100%,50%纳米含氟羟基磷灰石浸提液、100%羟基磷灰石浸提液、苯酚溶液及RPMI1640培养液培养传至第2代的L929细胞,MTT法检测培养2,4,7 d的吸光度值。 结果与结论：体外溶血性实验显示,各浓度梯度纳米含氟羟基磷灰石的溶血率均在5%以内,符合医用材料的溶血要求。体外细胞毒性实验显示,随着培养时间的增加,100%,50%纳米含氟羟基磷灰石浸提液组细胞贴壁覆盖率增加,细胞密度增高,细胞为长梭形或多角形,细胞增殖及形态与RPMI1640培养液组、羟基磷灰石组无明显差别,细胞毒性为0级。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

羟基磷灰石/聚苯硫醚复合材料的制备及体外生物相容性

背景:利用传统固相复合工艺难以将纳米级羟基磷灰石粉体与聚苯硫醚进行复合,从而无法发挥纳米材料的优势,并且目前缺少羟基磷灰石/聚苯硫醚复合材料生物相容性的相关研究。目的:应用液相复合工艺制备纳米羟基磷灰石/聚苯硫醚复合材料,评价其体外生物相容性。方法:应用液相复合工艺制备纳米羟基磷灰石/聚苯硫醚复合材料粉体和片材,利用红外光谱分析仪及扫描电镜分析复合材料的成分结构;利用接触角测试仪评估材料的亲水性,利用兔血及L929小鼠成纤维细胞进行材料的溶血实验及体外细胞毒性实验。结果与结论:通过液相复合工艺制备的羟基磷灰石/聚苯硫醚复合材料混合均匀,结合紧密;聚苯硫醚粉体的接触角为81.25°,而纳米羟基磷灰石/聚苯硫醚复合材料粉体接触角为16.1°;聚苯硫醚片材的接触角为83.5°,纳米羟基磷灰石/聚苯硫醚复合材料片材的接触角为42.5°,对比可知,纳米羟基磷灰石的加入明显改善了单纯聚苯硫醚材料的亲水性能。纳米羟基磷灰石/聚苯硫醚复合材料的溶血率为1.66%(5%),提示材料血液相容性良好;L929细胞在材料浸提液中生长良好,CCK-8法检测提示体外细胞毒性属无毒范畴(0至1级)。以上结果表明羟基磷灰石/聚苯硫醚复合材料制备成功,体外生物相容性良好。     

Counterpointing the functional role of the forebrain and of the brainstem in the control of the sleep-waking system

This paper reviews the lifetime contributions of the author to the field of sleep-wakefulness (S-W), reinterprets results of the early studies, and suggests new conclusions and perspectives. Long-term cats with mesencephalic transection show behavioral/polygraphic rapid eye movement sleep (REMS), including the typical oculo-pupillary behavior, even when the section is performed in kittens prior to S-W maturation. REMS can be induced as a reflex. Typical non-rapid eye movement S (NREMS) is absent and full W/arousal is present only after a precollicular section. The isolated forebrain (IF) rostral to the transection exhibits all features of W/arousal and NREMS [with electroencephalographic (EEG) spindles and delta waves], arousal to olfactory stimuli, and including the appropriate oculo-pupillary behaviors. These features also mature normally after neonatal transection. REMS is absent from the IF. After deprivation there is NREMS pressure and rebound in the IF, but the decerebrate cat only shows pressure for REMS. Most IF reactions to pharmacologic agents are within expectations, except for the tolerance/withdrawal effects of long-term morphine use which are absent. In contrast, these effects are supported by the brainstem (i.e. seen in the decerebrate cat). In cats with ablation of the telencephalon, or diencephalic cats, delta waves are absent in the thalamus. EEG thalamic spindle waves are seen triggering S for only 4-5 days after ablation. Therefore, true NREMS is absent in chronic diencephalic cats although pre- and postsomniac behaviors persist. These animals are hyperactive and show a pronounced, permanent insomnia; however, a low dose of barbiturate triggers a dramatic REMS/atypical NREMS rebound. Cats without the thalamus (athalamic cats), initially show a dissociation between behavioral hyperactivity/insomnia and the neocortical EEG, which for 15-20 days exhibits only delta and slower oscillations. Fast, low-voltage W rhythms appear later on, first during REMS, but spindle waves and S postures are absent from the start, such that these cats also display only atypical NREMS. Athalamic cats also show barbiturate-sensitive insomnia. Cats with ablation of the frontal cortices or the caudate nuclei remain permanently hyperactive. They also show a mild, but significant hyposomnia, which is permanent in afrontal cats, but lasts for about a month in acaudates. The polygraphic/behavioral features of their S-W states remain normal. We conclude and propose that: (a) the control of the S-W system is highly complex and distributed, but is organized hierarchically in a well-defined rostro-caudal manner; the rostral-most or highest level (telencephalon), is the most functionally complex/adaptative and regulates the lower levels; the diencephalic/basal forebrain, or middle level, has a pivotal role in inducing switching between S and W and in coordinating the lowest (brainstem) and highest levels; (b) W can occur independently in both the forebrain and brainstem, but true NREMS- and REMS-generating mechanisms exist exclusively in the forebrain and brainstem, respectively; (c) forebrain and brainstem S-W processes can operate independently from each other and are preprogrammed at birth; this helps understanding normal and abnormal polygraphic/behavioral dissociations in humans and normal dissociations/splitting in aquatic mammals; (d) NREMS homeostasis is present in the IF, but only REMS pressure after deprivation persists in the decerebrate cat; (e) the thalamus engages in both NREMS and W; (f) insomnia in diencephalic cats is the result of an imbalance between antagonistic W- and S-promoting cellular groups in the ventral brain (normally modulated by the telencephalon); (g) the EEG waves, which are signature for each S-W state, appear to truly drive the concomitant behaviors, e.g. a hypothetical human IF could alternate between behavioral NREMS and W/arousal/awareness; (h) a role for REMS is to keep the individual sleeping at the end of the self-limiting NREMS periods. The need for accelerating research on telencephaling NREMS periods. The need for accelerating research on telencephalic S-W processes and downstream control of the lower S-W system levels is emphasized.     

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.     

Adequate function of the cell: Interactions between the needs of the cell and the needs of the organism

The continuous maintenance of cell adequate function (cellular stress) is considered to be the main feature which characterizes the activity of a live cell. In accordance with the concept of cellular stress, the transition of the cell to the state of adequate funcitoning represents a dual commitment. The cell must function adequately to respond to the demands of the organism and to provide for its own needs. Thus, it is proposed that two systems exist for the regulation of the adequate function of the cell: one enabling the cell to respond to the demands of the organism, and the other providing for the needs of the cell itself. The hormonal system of the organism represents the first of these mechanisms, and I believe that another system exists for regulation of intracellular needs. Adequate function of the cell is determined by the regulative, controlling and defense mechanisms. The balance between the needs of the cell and of the organism should be a concern of physician, since it provides for the optimal function and health of the organism as a whole.     

The Beauty of the Network in the Brain and the Origin of the Mind in the Control of Behavior

Behavior is not adequately described as a stimulus-response process. It is initiated by the animal and is generated because of its expected outcome in the future. The outcome can be good or bad for the animal. The brain is in charge of the selection process. This is the basic function of the brain. Taking Drosophila as a study case, this paper discusses initiating activity, several examples of outcome expectations, trying out (the internal search for a suitable behavior), chaining of actions, and the functional roles of chance in action selection. It takes mental processes and states such as goals, intentions, feelings, memories, cognition, and attention as higher levels of behavioral control that have their origin in biological evolution.     

On the development of the sympathetic chain and the adrenal medulla in the mouse

Summary The first visible primordia of the sympathetic chain appear in the anterior thoracic region and run caudally through 8 segments in an embryo of 11 gestation days. At 12 gestation days the trunk reaches from the base of the skull into the sacral region. During the following days the trunk develops into ganglia with interganglionic fibers.At 16 gestation days there is a well developed trunk with a cranial ganglion cervicale superior and a ganglion stellatum in the anterior part of the thoracic region. In the remaining sympathetic chain there are segmentally arranged ganglia but in this common pattern large differences are noticed.At the 13th gestation day the first signs of the adrenal medulla and the splanchnic plexus appear in the form of sympathoblasts ventral to the sympathetic chain. The migration of sympathoblasts into the primordia of the adrenal cortex goes on for 3 days while the migration to the splancnic plexus in the mesenchym ventral and lateral to the aorta goes on at least 2 more days.     

指背腱膜滑动与近侧指间关节屈曲关系及临床意义

目的:探讨指背腱膜滑动距离与近侧指间关节(PIP)屈曲关系,为临床修复提供解剖学基础。方法:男性成人新鲜尸体标本10侧30指(示、中、环指各10指),切除手指皮肤,不破坏腱鞘、屈肌支持带、伸肌支持带、内在肌及外在肌,使肌腱保持正常的生理状态,分别测量各指中央束(CS)、侧束(LB)在PIP屈曲45°和90°时的滑动距离。结果:当PIP屈曲45°时,CS滑动距离为(2.7±0.4)mm,LB滑动距离为(2.8±0.6)mm;当PIP屈曲90°时,CS滑动距离为(4.3±0.7)mm,LB滑动距离为(4.8±0.6)mm。结论:指背腱膜滑动距离减少,严重影响手指的屈曲功能。对于指背腱膜的新鲜性损伤应予以精确修复;对于陈旧性损伤的修复应确保指背腱膜的正常滑动范围。     

Anatomical relationship between the morphology of the styloid process of the ulna and the attachment of the radioulnar ligaments

The radioulnar ligaments are the major stabilizers of the distal radioulnar joint under dynamic loading; however, anatomical detail regarding their attachment on the middle and distal thirds of the styloid process of the ulna remains unclear. Because previous anatomical studies included only old cadavers, their anatomical findings might not reflect the morphological features of younger and healthy specimens. This study investigated the anatomical features of the distal ulna, particularly the styloid process, to determine the attachment of the radioulnar ligaments to the styloid process and verified their direction and attachment to the styloid process in younger and healthy donors using magnetic resonance imaging (MRI). We investigated the morphological features of the distal ulna of 12 cadaveric wrists using micro-computed tomography (micro-CT). We also visualized and measured the distribution of the cortical bone thickness. We histologically analyzed three specimens in the axial plane and macroscopically analyzed seven specimens to examine the attachment of the radioulnar ligaments to the styloid process. In addition, we evaluated five wrists from living volunteers using 3.0 Tesla MRI. The distal ulna has a ridge on the dorsoradial aspect of the styloid process that corresponds to the attachment of the radioulnar ligaments. Micro-CT images after data processing revealed that the cortical thickness of the dorsoradial quadrant was thicker than that of the other quadrant at the proximal slice of the styloid process (p < 0.01), and that of the dorsoulnar (p = 0.021) and ulnopalmar (p < 0.01) quadrants at the middle slice. Histological analyses showed that the radioulnar ligaments were attached to the middle and distal thirds of the styloid process via chondral-apophyseal entheses. The direction of the fiber was dorsal in the middle third of the styloid process and changed to palmar in the distal third of the styloid process. The direction and attachment of the radioulnar ligaments on the styloid process were confirmed using MRI for younger and healthy participants. The radioulnar ligaments were attached to the dorsoradial ridge of the styloid process, which was confirmed by cortical bone thickening, histology at the attachment sites, and in vivo MR imaging. The directions of the radioulnar ligaments sterically intersected, which would satisfy both slipping stability and rotational mobility. These anatomical findings may provide the basis for biomechanical consideration of distal radioulnar joint stabilization.     

On the musculature of the gastro-intestinal tract of the guinea-pig

Summary The small intestine, caecum, colon and part of the stomach of guinea-pigs were studied by light microscopy, using semithin sections of plastic embedded specimens. The muscular coat is thicker in the duodenum than in the rest of the small intestine. The ratio between longitudinal and circular muscle is 1:4.6 in the duodenum and it increases regularly along the small intestine, to reach 1:2 in the terminal ileum. In the caecum, shape and sectional area of the muscle tissue were analyzed along the full length of the taeniae. In the caecal circular muscle there is a characteristic change in the arrangement of the muscle bundles from the regions in the centre of the haustrations to the regions of the grooves between haustrations or to those lying beneath a taenia. The functional significance of the taeniae is discussed in terms of an arrangement allowing reduction of the lumen of the organ (which at the level of the grooves between haustrations acquires a triangular outline) more efficiently than if the longitudinal musculature were spread over the entire surface of the organ. Haustrations are present also on one side of the wall of the ascending colon where there is no longitudinal muscle layer. In the descending colon the structure of the wall is examined in different functional states, namely in the regions between fecal pellets (constricted regions) and in the regions around a fecal pellet (moderately distended regions). The musculature increases considerably in thickness in the constricted regions (both muscle layers being actively contracted), while the mucosa and submucosa are thrown into prominent longitudinal folds. These folds produce occlusion of the lumen when the circular muscle has shortened by about 50%.     

On the origin of the corticotectal projections in the cat

Summary Stereotaxic injection of horseradish peroxidase into the superior colliculus produced retrograde labelling of layer V pyramides in the Clare Bishop area and the lateral bank of the suprasylvian sulcus, in area 17,18 and 19. Single labelled cells were also found scattered in the splenial, the suprasplenial, the lateral and the suprasylvian gyri. In the cruciate sulcus no labelled cells were observed. Autoradiographically, the lateral bank of the suprasylvian sulcus was also shown to give rise to fibres to the superior colliculus.