Mucopolysaccharide Material Resulting from the Interaction of Treponema pallidum (Nichols Strain) with Cultured Mammalian Cells

During incubation of Treponema pallidum (Nichols strain) with cultured mammlian cells derived from normal rabbit testes (NRT), an amorphous material accumulated at the surface of the cultured cells. This material was randomly distributed on all tissue cells within the culture chambers. The amount of amorphous material was dependent on the treponemal inocula. With 3 x 10(8) organisms per ml, this material was readily apparent within 2 days; with 4 x 10(7) organisms per ml, this material was detectable within 4 to 5 days; with lower inocula, the accumulation of amorphous material was far less apparent. Deposition of this surface-associated material required attachment of treponemes to the cultured cells, and the amount deposited was related to the number of treponemes attached per cell. This amorphous material was not detected when NRT cells were incubated with preparations of T. pallidum that were heat or air inactivated. In addition, the accumulaton of amorphous material was not due to a soluble component from host testicular tissue or to a soluble component developing during treponemal infection. This was demonstrated by the inability of membrane filtered preparations of T. pallidum to induce the deposition of amorphous material at the surface of the cultured cells. The nature of this material appeared to be acidic mucopolysaccharide as indicated by its metachromatic staining properties, its stainability with ruthenium red, and its partial degradation by bovine and streptomyces hyaluronidase. This amorphous material that accumulated in vitro at the surface of cultured cells may be similar to the mucoid material that accumulates in vivo during syphilitic infection.     

Relationship between the quality of fixation and the presence of stippled material in newly formed enamel of the rat incisor

Extracellular accumulation of a granular material that is presumed to be an organic “precursor” to mineralized enamel has been reported. This material, generally referred to as “stippled material,” was observed mainly after immersion fixation with osmium tetroxide. In studies with perfusion fixation, the presence of stippled material was inconsistent. Therefore, it appeared that the occurrence of stippled material was dependent on the method of fixation. To test this assumption, tissues were fixed by immersion in either osmium tetroxide or glutaraldehyde and by perfusion with either glutaraldehyde or a mixture of acrolein, glutaradehyde, and formaldehyde. It was found that as the quality of cellular preservation improved, the occurrence of stippled material decreased. Since no stippled material could be found in material judged to be well fixed, it was concluded that stippled material is not an extracellular precursor to mineralized enamel, but is a breakdown product resulting from poor fixation.     

基于均匀化理论的功能梯度材料力学性质的研究

目的利用均匀化理论讨论了功能梯度材料的细观结构形式对其宏观性能的影响。方法利用均匀化理论，研究组分材料泊松比、表观密度、弹性模量硬分布的影响。结果组分材料的泊松比对功能梯度材料的弹性模量的影响不仅与泊松比的大小有关．而且与组分材料的分布形式有关；组分材料的表观密度对功能梯度材料弹性模量的影响可用指数函数模拟；组分材料的弹性模最对功能梯度材料弹性模量的影响可用线性函数模拟；组分材料的分布对功能梯度材料弹性模量的影响甚微。结论功能梯度材料的弹性模量是受组分材料的泊松比影响的。     

Capsulelike surface material of Mycoplasma dispar induced by in vitro growth in culture with bovine cells is antigenically related to similar structures expressed in vivo.

Electron microscopy has been used to show that Mycoplasma dispar produces an external capsulelike material in vivo that has an affinity for both ruthenium red and polycationic ferritin. This extracellular material is lost upon passage in culture medium but can be regained with a single passage on bovine lung fibroblast (BLF) cells. To confirm that the extracellular material associated with cell-grown mycoplasmas was the same as that observed in infected calves, rabbit antibodies were produced to purified capsulelike material isolated by protease digestion of cell-grown organisms. These antibodies bound to capsulelike material on the surface of M. dispar cells colonizing the bronchial epithelium of infected calves and to capsulelike material from cell-grown mycoplasmas. Calves infected with M. dispar produced antibodies in lung secretions that were capable of binding to the purified capsulelike material. The Fab fragments of rabbit antibodies to in vitro-produced capsulelike material could block this binding, indicating that the capsulelike material was similar in both in vivo-grown and cell-grown organisms. The carbohydrate nature of the capsular material suggested by the ruthenium red and polycationic staining characteristics was confirmed by its binding to Ricinus communis agglutinin, a galactose-specific lectin. These studies confirm that capsule material produced during infections with M. dispar share antigenic determinants with the material produced under in vitro conditions and that association with mammalian cells induces production of this material.     

Biological evaluation of an apatite-mullite glass-ceramic produced via selective laser sintering

The biological performance of a porous apatite-mullite glass-ceramic, manufactured via a selective laser sintering (SLS) method, was evaluated to determine its potential as a bone replacement material. Direct contact and extract assays were used to assess the cytotoxicity of the material. A pilot animal study, implanting the material into rabbit tibiae for 4 weeks, was also carried out to assess in vivo bioactivity. The material produced by SLS did not show any acute cytotoxic effects by either contact or extract methods. There was no evidence of an apatite layer forming on the surface of the material when soaked in SBF for 30 days, suggesting that the material was unlikely to exhibit bioactive behaviour in vivo. It is hypothesized that the material was unable to form an apatite layer in SBF due to the fact that this glass-ceramic was highly crystalline and the fluorapatite crystal phase was relatively stable in SBF, as were the two aluminosilicate crystal phases. There was thus no release of calcium and phosphorus and no formation of silanol groups to trigger apatite deposition from solution within the test time period. Following implantation in rabbit tibiae for 4 weeks, bone was seen to have grown into the porous structure of the laser-sintered parts, and appeared to be very close to, or directly contacting, the material surface. This result may reflect the local environment in vivo compared to that artificially found with the in vitro SBF test and, furthermore, confirms previous in vivo data on these glass-ceramics.     

可降解血管支架材料的表面性能及生物相容性

BACKGROUND: Biodegradable stent implantation is a commonly used method in the clinical treatment of a variety of cardiovascular diseases. Importantly, the corresponding stent should have good surface properties and biocompatibility. OBJECTIVE: To observe the surface properties of the biodegradable vascular stent material, and to analyze its biocompatibility. METHODS: Artificial plasma was prepared for soaking the biodegradable magnesium alloy stent, and the corrosion of the material was observed by scanning electron microscope. Stent extraction solution was prepared and cytotoxicity test was carried out to observe the toxicity level of human umbilical vein endothelial cells cultured in the culture medium. Platelet adhesion test and hemolysis test were performed to detect cell and blood compatibility of the material. RESULTS AND CONCLUSION: After the 10-day immersion in artificial plasma, the material was scanned and a uniform corrosion layer was found on the surface of the material. During the drying of the material, some cracks appeared on the corrosion layer. After the corrosion products were removed, there were corrosion pits uniformly distributed on the corrosion surface of the material. In the cytotoxicity test, there were no absorbance values in the positive control group, and almost all of the cells died. After cultured in the material extraction, the toxicity level of human umbilical vein endothelial cells was graded 0 or 1. In the adhesion test, platelets on the stent surface were mostly disk-shaped under scanning electron microscope, some of which were deformed and extended pseudopodia, but no platelet aggregation occurred. The hemolysis rate of the material was 3.15%, in accordance with the requirement of the hemolytic rate < 5%. These experimental results show that the biodegradable magnesium alloy stent material has good corrosion resistance and good cell and blood compatibility, which can meet the demand of clinical application.      

重组人骨形态发生蛋白2/骨修复材料的制备与性能

BACKGROUND: It has become a hotspot to prepare the bone repair material that exhibits natural bone structure and is used in combination with biological factors. OBJECTIVE: To prepare the recombinant human bone morphogenetic protein-2 (rhBMP-2)/bone repair material, and to evaluate its capacities of release, activity and ectopic osteoinduction. METHODS: A collagen-binding domain was added to the N-terminal of native rhBMP-2 that allowed bind to collagens in the bone repair material. Then, rhBMP-2/bone repair material was obtained through freeze-dried method. The releasing ability of rhBMP-2 in vitro was assayed by ELISA. C2C12 cell lines were loaded to the composite material with 0.25, 0.5 and 1 µg rhBMP-2, respectively. Afterwards, alkaline phosphatase activity was detected at 72 hours. The composite materials with 0, 2, 5 and 10 µg rhBMP-2 were implanted into the quadriceps of Sprague-Dawley rats, respectively. Alkaline phosphatase activity and the newly formed bone were detected at 2 and 4 weeks after implantation. The CY-7-labeled composite material was implanted into the quadriceps of Sprague-Dawley rats to observe its stability. RESULTS AND CONCLUSION: Substantially no rhBMP-2 from the rhBMP-2/bone repair material was released within 45 days. The alkaline phosphatase activity of C2C12 was in a rise with the increased concentration of rhBMP-2. The stability of the composite material in vivo was better, the alkaline phosphatase activity and ectopic bone formation increased as the concentration of rhBMP-2 rose. To conclude, the rhBMP-2/bone repair material preserves the stability of rhBMP-2, and improves ectopic osteoinduction ability.     

Biodegradable material for bladder reconstruction.

The objective of this study was to develop a biodegradable material for use in reconstructive surgery of the bladder to serve a temporary function until normal regrowth of the host's tissue is completed. The biodegradable material can serve as a base over which the new bladder can regenerate. At the conclusion of the regrowth of the new tissue, the temporary material could be consumed by the body and therefore not have to be removed. Material evaluation showed that 70% acetic anhydride treated bovine pericardium was digested and dissolved in 4 weeks when implanted subcutaneously in dogs. Based upon this, supplementation of the bladder using this material was performed on 5 dogs. One dog showed urinary leakage and was sacrificed after 1 week. In 3 dogs examined 4, 6, and 48 weeks after implantation, respectively, the implanted material had been dissolved. In one animal autopsied at 10.5 months, a small remnant of the material still remained. Post-operative observation of the animals, excretory pyelocystograms and cystometry confirmed that the material applied was useful for experimental urinary bladder supplementation.     

Development of a resorbable macroporous cellulosic material used as hemostatic in an osseous environment

The control of bleeding is a frequently encountered therapeutic problem, particularly during dental surgery. The most efficient substances used to resolve this problem are not risk-free because of their animal or human origins, so cellulosic materials are potentially of interest. The aim of this study was to develop a resorbable macroporous cellulosic material for use as a resorbable hemostatic agent in bone sites. The degradation and the cytocompatibility of the cellulosic material versus controls were evaluated and its behaviour in vivo was studied. An original process using calcium carbonate powder as inverse matrix was used to develop a macroporous material. In order to predegrade the cellulosic material for hemostatic use, oxidation was performed with periodate. A dialdehyde component unstable at physiological pH was thus obtained. The material was found to have cytotoxicity, biocompatibility, and resorption properties similar to control but its hemostatic power was higher.     

人工植骨材料的生物学特性与临床应用

目的：总结近年有关人工植骨材料的生物学特性与临床应用现状。 方法：由作者应用计算机检索维普数据库,检索时限为1998-01/2010-10。检索关键词：骨充填材料,骨缺损,骨肿瘤,骨病,骨组织工程。纳入与各种人工植骨材料的生物学特性与临床应用有关的文献,对资料进行初审,并查看每篇文献后的引文。共15篇文献符合标准纳入结果分析。 结果：人工植骨材料包括无机材料、有机材料和复合材料,复合材料组合了前两者的优势,具备较好的生物安全性、生物相容性、生物活性及生物力学性能。在四肢骨折内固定或骨肿瘤刮除后于骨缺损处植入人工骨,明显加速骨骼愈合过程．降低延迟愈合或不愈合的发生率,有较大临床应用价值。 结论：人工植骨材料在促进骨愈合、椎体融合效果接近自体骨,无排异反应,具有良好的生物相容性。     

Poly-L-lactide surfaces subjected to long-term cell cultures: cell proliferation and polymer degradation

Short term cell cultures are usually grown in contact with biomaterials to assess cytocompatibility. Depending on the rate of material degradation or corrosion, the time of culture can be a key-point in the method which, if too short, may not show any effect of the released material on the cells. A long term culture was therefore carried out with L929 fibroblast cells in contact with PLLA/PDLA samples for up to eight months. The degradation was measured in terms of shear-strength properties, intrinsic viscosity of the material and its cristallinity. The effect of the material on the cells was evaluated by measuring the growth rate of the cells. A significant decrease in the shear strength of the material was measured after three months. The rate of modification of the intrinsic viscosity was regular and decreased progressively throughout the culture period. Differential scanning calorimetry showed that the samples were initially essentially amorphous and that contact with the cell culture and its medium did not change its crystallinity level. The growth rate of the cells was not modified by the presence of the material when compared to the control. This study showed this material to be cytocompatible for a long period of time, even after detection of modifications of its physico-chemical properties.     

Scanning electron microscopy, x-ray diffraction, and electron microprobe analysis of calcific deposits on intrauterine contraceptive devices

Deposits found intrauterine contraceptive devices (IUDs) were studied by scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray microanalysis. All seven devices, including five plastic and two copper IUDs, were coated with a crust containing cellular, acellular, and fibrillar material. The cellular material was composed of erythrocytes, leukocytes, cells of epithelial origin, sperm, and bacteria. Some of the bacteria were filamentous, with acute-angle branching. The fibrillar material appeared to be fibrin. Most of the acellular material was amorphous; calcite was identified by x-ray diffraction, and x-ray microanalysis showed only calcium. Some of the acellular material, particularly that on the IUD side of the crust, was organized in spherulitic crystals and was identified as calcium phosphate by x-ray microanalysis. The crust was joined to the IUD surface by a layer of fibrillar and amorphous material. It is suggested that the initial event in the formation of calcific deposits on IUD surfaces is the deposition of an amorphous and fibrillar layer. Various types of cells present in the endometrial environment adhere to this layer and then calcify. Thus, the deposition of calcific material on the IUDs is a calcification phenomenon, not unlike the formation of plaque on teeth. Hum Pathol 16:732-738, 1985.     

脱细胞胶原基质双层材料与骨髓间充质干细胞的生物相容性研究

目的 对脱细胞胶原基质双层材料和骨髓间充质干细胞（BMSCs）间的生物相容性进行研究.方法 将BMSCs与脱细胞胶原基质双层材料共培养作为实验组,单独培养的BMSCs为对照组,对BMSCs的生长和增殖情况进行研究,扫描电镜下观察细胞在材料上的贴附生长情况,并采用CCK-8法测定细胞活性.结果 扫描电镜结果显示BMSCs在脱细胞胶原基质双层材料上生长良好.CCK-8法测得的BMSCs与脱细胞胶原基质双层材料共培养的生长曲线显示,实验组与对照组间差异无统计学意义（P＞0.05）.结论 脱细胞胶原基质双层材料具有较好的生物相容性,这为脱细胞胶原基质组织工程支架双层材料下阶段在体内动物中的应用提供了科学依据.     

新型大孔隙磷酸钙骨水泥作为骨组织工程支架的相关研究

目的 探讨新型大孔隙磷酸钙骨水泥(CPC)材料支架的细胞毒性和对细胞黏附、生长和增殖的影响.方法 通过添加甘露醇制孔剂和应用磷酸钠溶液作为CPC固化液的方法合成新型CPC材料.通过CCK8法检测细胞在新型CPC材料浸提液中的生长增殖情况;通过电子扫描电镜测试材料孔径和细胞在材料表面上黏附生长情况;应用力学三点弯曲实验测试新型CPC的生物力学性能.结果 新型CPC材料的孔径值达到(267.43±118.01)μm,孔隙率为(66.15±6.91)％.新型CPC材料的最大负荷、抗弯强度和坚韧度较传统CPC均增加了约1倍(P＜0.05).新型CPC材料浸提液与细胞共培养2、4、6、8d后CCK8法测试吸光度(OD)值与阴性对照组比较其差异无统计学意义(P＞0.05).结论 新型CPC材料具有强大的生物力学性能、大孔隙、高孔隙率和良好的生物相容性,有望成为理想的骨组织工程支架.     

Subtyping of nonsmall cell lung cancer on cytology specimens: Reproducibility of cytopathologic diagnoses on sparse material

Cytologic examination of fine‐needle aspiration (material is increasingly used in diagnosing lung cancer. High interobserver agreement in distinguishing small‐cell lung cancer from nonsmall‐cell lung cancer (NSCLC) on cytologic material has been demonstrated. Because of new treatment‐modalities, subclassification of NSCLC into squamous cell carcinoma (SQC) and non‐SQC has clinical impact. Subclassification based on morphology alone may be difficult, but applying immunohistochemistry (IHC) to clot‐material has proved helpful. When insufficient material is available to make a clot from the aspirate, cytoscrape (CS) can convert cytologic material into tissue fragments useful for IHC. The purpose of this study was to test the reproducibility of pulmonary malignant diagnoses, in particular distinction between subgroups of NSCLC, based on smeared material and IHC on CS. A consecutive series of May–Grunwald–Giemsa (MGG) stained smears and CS with IHC on material from 79 patients suspected of having lung cancer was included. The material was circulated twice to four pathologists. The diagnoses were categorized in five groups: SQC, adenocarcinoma of the lung, non‐SQC, benign lesion and other forms of malignancy, including metastases. Reproducibility was analyzed using Kappa statistics. Interobserver reproducibility of the diagnoses in round 1 was good to very good (kappa 0.57–0.71) and very good in round 2 (0.63–0.80). Reproducibility of subclassification of NSCLC based on MGG stained smear and IHC on CS, was very good among experienced pathologists. With only sparse material available, CS should be used to achieve reproducible diagnoses, including subtyping of NSCLC. Diagn. Cytopathol. 2014;42: 105–110. © 2013 Wiley Periodicals, Inc.     

不饱和聚磷酸酯/β-磷酸三钙复合材料修复骨缺损的实验研究

目的 观察以不饱和聚磷酸酯（UPPE）／β-磷酸三钙（β—TCP）制备的复合材料对骨缺损的修复效果。方法利用溶液浇铸法技术制备UPPE／β-TCP复合材料。将36只新西兰大白兔随机等分为两组,手术造成右股骨髁部腔洞状直径8mm骨缺损,实验组植入直径8mm复合材料,对照组作空白对照。通过影像学、组织学、图像分析技术观察骨缺损的修复效果及材料的降解情况。结果影像学结果表明,实验组术后8周新生骨痂将缺损修复,术后16周骨痂塑形良好;对照组术后16周内均无骨痂形成,缺损未修复。组织学显示,实验组术后8周复合材料降解成较大的数块,有新骨形成;术后16周正常骨与材料之间形成贯通的髓腔;对照组为少量纤维组织连接。术后8周和16周材料降解率分别是30．3％和52．2％。结论以不饱和聚磷酸酯／β-磷酸三钙制备的骨修复材料对骨缺损具有良好的修复作用。     

Mechanical and morphological study of biostable polyurethane heart valve leaflets explanted from sheep

Two novel biostable polyurethanes, designated EV3.34 and EV3.35, were used to manufacture a flexible trileaflet heart valve. The valves were implanted in the mitral position in young adult (18 month) sheep. Six valves were electively explanted at 6 months and the remaining six valves at 9 months follow-up. The leaflet material was examined by surface Fourier transform infrared spectrometry (ATR/FTIR) and scanning electron microscopy (SEM). The leaflet material was also subjected to cyclic mechanical testing and, compared with unimplanted control material, to demonstrate any change in mechanical properties during implantation. There was no degradation of functional groups detected by ATR/FTIR, although there was a slight surface enrichment of siloxane soft segment. Surface morphology of the explanted leaflet material was similar to unimplanted control material. EV3.34 demonstrated similar inelastic energy loss behavior, with no significant change in residual strain in explanted compared with control material. EV3.35 demonstrated a reduction in inelastic energy and residual strain in explanted compared with control material. There is no evidence of biodegradation of these siloxane-based polyurethanes, in functional valves up to 9 months implantation in sheep. The FTIR and SEM findings are supported by the retention of mechanical properties of the materials.     

自制IPS-Empress2铸瓷快速包埋材料的膨胀特性研究

IPS—Empress2铸瓷是国内外广泛应用的全瓷修复系统。为取代昂贵的进口专用包埋材料，国内已自制出与之相配套的快速包埋材料。本文研究的是其最关键的膨胀特性。采用千分尺位移计和热机械分析仪，分别测量了进口专用快速包埋材料和自制快速包埋材料的凝固膨胀及热膨胀性能，进行了统计分析和比较。结果显示，进口专用快速包埋材料的凝固膨胀率、热膨胀率和总膨胀率分别为0．858％、1．11％和1．17％；自制包埋材料的上述指标分别为0．798％、1．09％和1．16％，三项指标均无统计学差异，表明自制快速包埋材料的膨胀性能指标接近IPS—Empress2专用快速包埋材料，能满足IPS—Empress2铸瓷精密铸造的要求。     

离心法测定细胞与材料之间黏附强度的研究

建立一种简单的离心法用以评价细胞与材料之间的黏附强度。改造离心涂片机以适合研究需要；建立离心法测定三种贴壁细胞（HeLa、SH～SY5Y、ECV304）在两种材料（聚苯乙烯板、丝素蛋白膜）上的黏附强度，以研究在不同的培养时间下三种贴壁细胞在两种材料上的黏附情况。结果表明在相同的培养时间下，三种贴壁细胞与丝素蛋白膜的黏附强度强于与聚苯乙烯的黏附强度，其黏附强度的大小可以相对量化。结论该离心法检测细胞对生物材料黏附强度的方法简单易行，重复性高；丝素膜材料是一较为理想的生物材料。     

In vivo evaluation of a porous hydroxyapatite/poly-DL-lactide composite for bone tissue engineering

As reported previously, a porous composite of uncalcined hydroxyapatite (u-HA) and poly-DL-lactide (PDLLA) showed excellent osteoconductivity and biodegradability as a bone substitute in rabbit model. In this study, to investigate the usefulness of this composite as a scaffold loaded with cells, we estimated whether this material showed osteogenesis on implantation to extraosseous site. On loading with syngeneic bone marrow cells and implantation into rat dorsal subcutaneous tissue, osteogenesis with enchondral ossification was seen both on and in the material at 3 weeks after implantation. The osteogenesis in the u-HA/PDLLA had progressed, and newly formed bone tissue was found in the material by 6 weeks. To investigate the osteoinductive properties of the material, we implanted this porous composite material into extraosseous canine dorsal muscle. At 8 weeks, osteogenesis was seen in the pores of the material. Newly formed bone could be observed adjacent to the material. In addition, cuboidal osteoblasts adjacent to the newly formed bone were evident. Neither cartilage nor chondrocytes were found. These results might indicate that the material induced osteogenesis by intramembranous ossification. Conversely, similar porous PDLLA did not induce osteogenesis during the observation period. Therefore, porous HA/PDLLA, which has osteoconductive and osteoinductive properties, might be a useful material for use as a bone substitute and cellular scaffold.