In vitro bioactive behavior of hydroxylapatite-coated porous Al(2)O(3)

To produce bioactive materials for bone substitutes, two major deposition methods, suspension method and thermal deposition method, were employed to develop bioactive, mechanically strong, and porous ceramics. Hydroxylapatite (HA) has been uniformly coated onto inner pore surfaces of reticulated alumina substrates. It has been found that the in vitro bioactivity of HA coatings was affected by both structural crystallinity and specific surface area. Well-crystallized HA heat-treated at high temperatures has resulted in reduced bioactivity. The bio-reaction rate was found to increase with the surface area of HA. We have found that the stability of the well-crystallized HA is associated with the high driving force required for the formation of hydroxy-carbonate apatite (HCA) phase.     

Ergebnisse der klinischen Prüfung des Glukoneogenesehemmers 2-(3-Methylcinnamylhydrazono)-Propionat (MCHP)

Summary Many compounds which directly or indirectly inhibit gluconeogenesis have been described. Some of them showed hypoglycemic action in animal experiments.2-(3-Methylcinnamylhydrazono)-Propionat (MCHP) a derivative of hydrazine demonstrated marked hypoglycemic action in animal experiments. Nontheless the administration of MCHP to type II diabetic patients showed no hypoglycemic action. Clinical or biochemical sideeffects could not be observed.

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Abkürzungen MCHP 2-(3-methylcinnamylhydrazono)-Propionat - yGT Gamma-Glutamyl-Transferase - GOT Aspartataminotransferase - GPT Glutamyltranspeptidase - HDL-Cholesterin High density Lipoprotein-Cholesterin - BZ Blutzucker     

生物医用纳米(Y0.95Eu0.05)2O3的体外细胞相容性

背景：与有机荧光染料和荧光蛋白相比,稀土纳米材料具有更高的灵敏性和更好的光学稳定性,并且具有更低的细胞毒性。目的：探讨(Y_0.95Eu_0.05)₂O₃稀土纳米材料的体外细胞相容性,以及氨基化修饰对材料细胞相容性的影响。方法：采用溶胶-凝胶法合成(Y_0.95Eu_0.05)₂O₃稀土纳米材料,并进行氨基化修饰。将10,25,50,100,200 mg/L的氨基化与非氨基化(Y_0.95Eu_0.05)₂O₃稀土纳米材料悬液分别与SD大鼠血管平滑肌细胞共培养3 d,CCK-8法检测细胞增殖;将100 mg/L的氨基化与非氨基化(Y_0.95Eu_0.05)₂O₃稀土纳米材料悬液分别与L929细胞共培养48 h,荧光染色观察细胞凋亡。结果与结论：随着材料悬液质量浓度的升高,血管平滑肌细胞存活率呈逐渐减少趋势;在材料质量浓度为10,25,50 mg/L时,氨基化组细胞存活率明显高于未氨基化组(P < 0.05);当材料质量浓度高达200 mg/L时,未氨基化组细胞存活率降到76%,氨基化组细胞存活率仍然在80%以上,两组比较差异有显著性意义(P < 0.05)。氨基化组L929细胞生长状况良好,凋亡细胞数量较少;未氨基化组生长较稀疏,细胞凋亡数量较多,显示出轻微的细胞毒性。表明氨基化修饰可以有效提高(Y_0.95Eu_0.05)₂O₃稀土纳米材料的细胞相容性。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：     

Controlled synthesis of α,β-difunctional poly(hexafluoropropylene oxide)

An improved method is described for the preparation of difunctional poly(hexafluoropropylene oxide) of moderate molecular weight (M _n ≈ 6000) in good yield (>80 wt.-%). With the dependence of chain transfer constant on initiator concentration known, at least under controlled conditions, good molecular-weight control can be achieved.     

Polymer modification and synthesis using sulphenyl derivatives, 2. Preparation of poly(β-chlorothioether)s,poly(sulphone)s and poly(disulphide)s

The preparation of a further series of poly(β-chlorothioether)s, from reaction of 4,4′-methylenedisulphenyl chloride ( 2 ) with diolefins, is described. Poly(sulphone)s were prepared by controlled oxidation of the poly(β-chlorothioether)s from 2 and from 4,4′-biphenyldisulphenyl chloride ( 1 ). Poly(disulphide)s were prepared by reaction of 1 or 2 with dithiols or lithium metal. All the above polymers were characterized by NMR, IR, elemental analysis, and rel. mol. mass determinations.     

Radioimmunoassay of detirelix ([ N-Ac-D-Nal(2)1,D-p-Cl-Phe2,D-Trp3, D-hArg(Et)6(2),D-Ala10]-luteinizing hormone-releasing hormone) in plasma or serum

A procedure for the radioimmunoassay (RIA) of detirelix in plasma or serum at concentrations as low as 0.15 ng/ml is described. Antiserum was produced by deacetylation of the N-terminus amino groups of detirelix and coupling this analog to bovine serum albumin with a carbodiimide and immunizing rabbits with the resultant conjugate. For RIA, 125I-labeled detirelix was used as the tracer and a double antibody procedure was used to separate the free and bound fractions. No purification of samples was required prior to RIA. Accuracy of the method was assessed by adding known quantities of detirelix to detirelix-free plasma and determining the ratio of measured to added analyte. Linear regression analysis for the concentration range 0.15-150.0 ng/ml yielded a regression equation of y = 0.88 X +1.46 and a correlation coefficient of 0.996. Additional validation was obtained from an in vivo study in which [14C]detirelix was administered to monkeys and plasma clearance profiles were determined by RIA and an HPLC-radiochemical method. The RIA results were in good agreement with those obtained by the HPLC method.     

In vitro cloning of murine megakaryocyte progenitors (CFU-Meg)

Summary Convenient and reproducible culture systems for murine megakaryocyte progenitor cells (colony-forming unit-megakaryocytes, CFU-Meg) are described. Mouse bone marrow cells are cultured in fibrin clots supplemented with Iscove's modified Dulbecco's medium and fetal bovine serum or in fibrin clots supplemented with serum-free IMDM, bovine serum albumin, transferrin, cholesterol, and L--phosphatidylcholine. In the presence of murine interleukin-3 or pokeweed mitogen-stimulated murine spleen cell-conditioned medium, these cultures support CFU-Meg colony formation effectively. The cultivation and counting of colonies in these culture systems is considerably easier when compared with previously reported culture systems.     

Sulfur-containing optically active polymers, 1. Synthesis and chiroptical properties of poly(γ-ketosulfide)s derived from (−) (2R, 3R)-1,4-dimercapto-2,3-butanediol

The synthesis of optically active poly(γ-ketosulfide)s from bis-Mannich bases or α,β,α′,β′-unsaturated ketones and (?) (2R, 3R)-1, 4-dimercapto-2,3-butanediol, is described. The corresponding low-molecular-weight analogs were also synthesized. The products were fully characterized and their stereochemical features investigated by NMR. The relations between chiroptical and conformational properties in solution were also studied by circular dichroism measurements. Although an appreciable local asymmetric induction on the chromophores belonging to the starting achiral co-reagent is observed, the macromolecules do not display any occurrence of ordered secondary structures due to a low stereoregularity degree orginated by the presence of randomly distributed constitutional repeating units having different diastereomeric configurations.     

In vitro activity of (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)-adenine against newly isolated clinical varicella-zoster viras strains

The highly potent and selective anti-DNA virus agent (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA] was found to inhibit in vitro the replication of a number of clinical varicella-zoster virus strains within the concentration range of 0.63—5.7 ng/ml. With a mean 50 % inhibitory concentration of 1.8 ng/ml and selectivity index of 29000, (S)-HPMPA is one of the most potent and most selective varicella-zoster virus inhibitors discovered to date.     

Chronic idiopathic myelofibrosis (CIMF) resulting from a unique 3;9 translocation disrupting the janus kinase 2 (JAK2) gene

We report a case of t(3;9)(q21;p24) in a patient with chronic idiopathic myelofibrosis (CIMF), a chronic myeloproliferative disorder (CMPD), initially detected by G-banding and fluorescent in situ hybridization (FISH) in an unstimulated culture of peripheral blood. Subsequent cytogenetic studies of bone marrow aspirates showed the presence and persistence of the same translocation. No additional cytogenetic abnormalities were found. This appears to be a unique translocation that has not been previously reported in the English literature, although both breakpoints, 3q21 and 9p24, are well known cancer-related breakpoints. The former is the mapped location of the ribophorin 1 (RPN1) gene, whereas the latter is the mapped location of the janus kinase 2 (JAK2) gene. This raises the possibility that disruption of one or both loci at the breakpoints of the presently described structural chromosomal rearrangement may be the primary event leading to the initiation and development of the hematopoietic disorder in this patient. It is not unreasonable to hypothesize that the juxtaposition of the RPN1 gene on 3q21 with the JAK2 gene on 9p24 leads to enhanced JAK2 activity. Additional studies will be needed to provide further support for or to disprove this hypothesis. To the best of our knowledge, this is the first reported case of CIMF associated with a reciprocal 3;9 translocation with the 3q21 and 9p24 breakpoints. The elucidation of the mechanism of leukemogenesis in CIMF may one day lead to successful targeted therapy in this hematopoietic disorder. It may also shed additional light on the diagnosis, prognosis and treatment of certain other cancers with similar genetic etiologies.     

Detection of circulating immune complexes with polyethylene glycol precipitation F(ab')2 anti-C3 ELISA

A polyethylene glycol (PEG) precipitation F(ab')2 anti-C3 ELISA for the detection of complement-fixing IgG circulating immune complexes (CIC) is described. For this assay, test sera were treated with 3.5% PEG and then measured with F(ab')2 anti-C3 ELISA. The lower detection limit was 4 micrograms/ml of heat aggregated human IgG (HAHG). Intra-assay coefficient of variation (CV) was 4.9-8.3%. High levels of CIC are found in the sera of patients with systemic lupus erythematosus (SLE), hepatitis B and stomach cancer.     

Synthesis, characterization and biocompatibility of poly(2-ethyl-2-oxazoline)-poly(D,L-lactide)-poly(2-ethyl-2-oxazoline) hydrogels

A novel thermoreversible hydrogel based on poly(2-ethyl-2-oxazoline)-derived amphiphilic triblock copolymer, poly(2-ethyl-2-oxazoline)-poly(D,L-lactide)-poly(2-ethyl-2-oxazoline) (PEOz-PLA-PEOz), was developed. The synthesis of PEOz-PLA-PEOz was carried out by coupling monohydroxylated PEOz-PLA diblocks with adipoyl chloride as coupling agent and dimethylamino pyridine as catalyst. The tube inverting and rheological tests showed that triblock copolymers had sol-gel-sol transition behavior with increasing temperature, and the gelation was found to be thermoreversible. The critical gelation concentration, the sol-gel transition temperature at a given concentration depended on the EOz/LA ratio and the molecular weight of PEOz. Scanning electron microscopy observation revealed that the resultant bulky gel exhibited an interconnected porous three-dimensional (3D) microstructure after freeze-drying. In addition, the hydrogels showed good cytocompatibility in vitro. MTT assays revealed that the human skin fibroblast cells encapsulated within the hydrogels were viable and proliferated inside the 3D scaffold. This newly described thermoreversible hydrogel demonstrated attractive properties to serve as cell matrix for a variety of tissue engineering applications or pharmaceutical delivery vehicles.     

Properties of polyacetylene obtained with (η-Cp)2Ti(PMe3)2

Acetylene was polymerized by (η-Cp)₂Ti(PMe₃)₂ at room temperature to give predominantly trans-polyacetylene. All properties are within the ranges reported for polyacetylene produced with Ti(OBu)₄/AlEt₃ as catalyst.     

Preparation of poly(ethylene glycol) grafted poly(3-hydroxyalkanoate) networks

Poly(3-hydroxyalkanoate)-g-poly(ethylene glycol) crosslinked graft copolymers are described. Poly(3-hydroxyalkanoate)s containing double bonds in the side chain (PHA-DB) were obtained by co-feeding Pseudomonas oleovorans with a mixture of nonanoic acid and anchovy (hamci) oily acid (in weight ratios of 50/50 and 70/30). PHA-DB was thermally grafted with a polyazoester synthesized by the reaction of poly(ethylene glycol) with MW of 400 (PEG-400) and 4,4′-azobis(4-cyanopentanoyl chloride). Sol-gel analysis and spectrometric and thermal characterization of the networks are reported.     

In vitro study on hemocompatibility and cytocompatibility of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

Samples of polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) containing 4–20% (mol/mol) 3-hydroxyhexanoate (3HHx) were characterized as potential components of blood-contact biomaterials. In an erythrocyte contact hemolysis assay, all tested PHBHHx films had substantially reduced reactivity, typically displaying about 2-fold less hemolytic activity compared with that of PHBV. Both 12% and 20% containing PHBHHx also bound less platelets than other films. After a 120-min exposure to platelet-rich plasma (PRP), few platelets adhered to the 12% and 20% containing PHBHHx films, while numerous platelets were seen on PHBV. Surface properties investigation suggested along with increasing 3HHx content, PHBHHx co-polymer films became smoother and smoother, which may contribute to lower platelet adhesion of PHBHHx containing high HHx content in a short-term contact to platelet-rich plasma. In a long-term contact to PRP, the difference in crystallization of PHBVand PHBHHx can be a critical parameter for platelet adhesion. Human umbilical vein endothelial cells (HUVECs) grew well on PHBHHx containing high content of 3HHx, indicating that both had good biocompatibility with HUVECs. While gelatin-coated or lipase-treated polyesters improved HUVECs proliferation compared with that on uncoated films, platelet adhesion was also decreased on gelatin-coated polyester. The hemocompatibility and biocompatibility of PHBHHx film were markedly improved. Thus, PHBHHx, particularly the surface-modified PHBHHx film, is promising for blood-contact materials.     

Flip angle considerations in (3)helium-MRI

3Helium-MRI ((3)He-MRI) can be used for analysis of lung function, e. g. dynamic imaging of ventilation and gas diffusion within the lung, assessment of intrapulmonary oxygen concentrations and their time course. During imaging, the irreversible signal loss due to depolarizing radio frequency excitations can be described using the flip angle (FA) alpha. This parameter has to be quantified in order to account for it during quantitative assessment of the (3)helium signal intensity and its temporal development. This technical report reviews two different methods to determine alpha. Limitations and possible error sources of each method are discussed.     

Precipitation of carbonated apatite in the cement system alpha-Ca(3)(PO(4))(2)-Ca(H(2)PO(4))(2)-CaCO(3).

Powder mixtures of alpha-Ca(3)(PO(4))(2), Ca(H(2)PO(4))(2), and CaCO(3) were investigated to assess their potential for the precipitation of a carbonated apatite suitable for cement applications from a supersaturated solution. Of particular interest was the requirement of carbon dioxide release during the setting reaction to obtain Ca(9-x)(HPO(4))(1-1.5x) (PO(4))(5-2.5x)(CO(3))(3.5x)(OH)(1 + 1.5x) with a fixed carbonate content. Results indicated that a compromise is necessary with respect to the maximum permissible level of CaCO(3) addition to the powder mixture as against appropriate setting and hardening properties. Cementlike materials with good setting and hardening properties were obtained when alpha-Ca(3)(PO(4))(2) was the main reactant using Ca(H(2)PO(4))(2) and CaCO(3) as additives in relative proportions of <10 wt % corresponding, approximately, to the stability field area (x,lambda) contained within the lines lambda = -1.5x, x = 0.3, and lambda = -1. Desirable workability and setting properties were lost as the parameters x and -lambda increased. Finally, it was also found to be virtually impossible to obtain a predetermined chemical composition for the setting apatite precipitate, since to increase the amount of carbon dioxide released from the initial powder mixture during setting, the solution pH would need to be decreased, and in doing so the nature of the precipitate could be altered to fulfil the thermodynamic conditions of the solubility diagrams of calcium phosphates.     

Polymeric phospholipid analogues, 20. Synthesis and polymerization of 20-(methacryloyloxy)icosyl 2-(trimethylammonio)ethyl phosphate and 32-(methacryloyloxy)dotriacontyl 2-(trimethylammonio)ethyl phosphate

20-(Methacryloyloxy)icosyl 2-(trimethylammonio)ethyl phosphate ( 4a ) and 32-(methacryloyloxy)dotriacontyl 2-(trimethylammonio)ethyl phosphate ( 4b ) were prepared and characterized. These monomers were polymerized and the properties of the resultant polymers are described.     

Novel translocation (2;4) with consistent involvement of 2p23 in acute nonlymphocytic leukemia (M2).

A translocation involving the short arm of chromosome 2 and the long arm of chromosome 4 is described in three patients, all of whom had acute nonlymphocytic leukemia (M2). One patient had M2 de novo, one progressed from refractory anemia with excess blasts in transformation to M2 over a 4-month period, and one had had sideroblastic anemia 30 years prior to development of M2. In all three patients, the translocation involved the breakpoint p23 on chromosome 2, but the breakpoints on chromosome 4 varied between q25, q31, and q35. Translocations specifically involving 2p23 have not previously been described in leukemia, but more cases are required to identify a specific association with either the FAB type or prognosis.