水泥型羟基磷灰石人工骨的制备及性能分析

Objective: To prepare hydroxyapatite cement (or calcium phosphate cement,CPC) and analyze its capability. Methods: Tetracalcium phospluge (TTCP ) was prepared by the method of high heat. TTCP reacted with in simulated body situation and produced CPC. Its capability was analyzed by scanning electron microscopy ( SEM), X-ray diffraction( XRD). Its density, absorbing water coefficient, macroporosity and compressive strength were measured also. Results: The main element of CPC is hydroxyapatile (HA), its microstructure comprised of petal crys-tals. The diameter of micropore was 4-10μm, density was 1. 922 g/cm^3, macroporosity was 29. 777%, absorbing coefficient was 15. 503%, compressive strength was 42.70 Mpa. Conclusion: This CPC has three-dimensional spatial structure, its strength meets the need of cancellous bone grafting.     

PLACENTAL CALCIUM PUMP: CLINICAL-BASED EVIDENCE

Placenta can be considered as a pump of calcium necessary for the normal development of the fetus. We believe that the location of this pump is in the placental basement membrane. The calcification of this membrane has been described only in cases of in utero fetal death. In this study we describe for the first time a case of placental calcification in a living fetus. The fetus of a normal 21-year-old pregnant woman showed heart abnormalities but the genetic analysis showed a normal male karyotype. The histology of the placenta demonstrated multiple intravillous linear and granular calcific incrustations The hemtoxylin/eosin stain of the sections revealed basement membrane calcific incrustations and intravillous calcium deposits. We postulate that the fetal circulation in the villi was impaired and the calcium that reached the villi from the mother was deposited at this level.     

Fumonisins as a possible contributory risk factor for primary liver cancer: A 3-year study of corn harvested in Haimen, China, by HPLC and ELISA

Employing HPLC fluorometry, gas-liquid chromatography (GLC) and a novel enzymelinked immunosorbent assay (ELISA) based on a monoclonal antibody, 40 corn samples, each collected in 1993 from agricultural stocks for human consumption in Haimen (Jiangsu County) and Penlai (Shandong Province), high- and low-risk areas for primary liver cancer (PLC) in China, respectively, were analysed for fumonisins (FBs), aflatoxins (AFs) and trichothecenes. Levels and positive rates of FBs and deoxynivalenol (DON) were significantly higher in Haimen than in Penlai. ELISA of the 40 corn samples harvested in the two areas in 1994 revealed that FB contamination levels and rates in these areas were comparable to those observed in 1993 in Haimen. ELISA analysis of 1993 and 1994 products revealed a wide occurrence of AFB₁ but the positive rates as well as levels were not significantly different between these areas. ELISA of the same sample number of corn harvested in 1995 revealed that FB contamination in Haimen was significantly higher than in Penlai. These 3-yearly surveys of corn samples (240 in total) demonstrated that corn harvested in Haimen was highly contaminated with FBs and that the contamination level, as well as positive rate in 1993 and 1995, were 10–50-fold higher than those in Penlai, suggesting FBs as a risk factor for promotion of PLC in endemic areas, along with the trichothecene DON. Co-contamination with AFs, potent hepatocarcinogens, was assumed to play an important role in the initiation of hepatocarcinogenesis.     

水泥型羟基磷灰石人工骨的制备及性能分析(英文)

目的:制备水泥型羟基磷灰石人工骨,并进行性能分析。方法:高温法制备出磷酸四钙,然后在模拟体内环境下将其与无水磷酸氢钙发生水化固化反应,合成水泥型羟基磷灰石人工骨,采用X线衍射、扫描电镜观察、体积密度、吸水率、孔隙率及耐压强度测量进行性能分析。结果:该人工骨主要成分为低结晶度的羟基磷灰石;微观结构呈针状或花瓣状晶体构成,微孔直径约4-10 μm,孔隙相互交通;平均体积密度为1.922 g·cm~(-3);平均吸水率为15.503％;孔隙率为29.777％;耐压强度为42.70 MPa。结论:本研究所制人工骨具有三维空间结构,力学性能符合人体非负重骨植骨要求。     

Artificial bone of porous tricalcium phosphate ceramics and its preliminary clinical application

Summary The authors have prepared the artificial bone of porous tricalcium phosphate ceramics according to an appropriate formula and manufacturing technology. Physical and chemical testing shows that it possesses several distinguishing features: the communicating pores and macro/micropores; mean pore size, 380 μm (from 240 μm to 510 μm); porosity, 46.4 %; and compressive strength, 97.4 kg/cm². It consists of CaO (49.09 %) and P₂O₅ (48.84 %). The testing of its biocompatibility shows that it is devoid of systemic or local toxicity, and free of irritation or foreign body response in tissues, and it does not result in hemolysis or mutation. The new bone readily grows into its pores with direct contact to the implanted material. 11 cases of bone defects were treated with this artificial bone with satisfactory results.     

预防性应用钙拮抗剂对缺血大鼠心肌细胞和红细胞内钙变化的影响

利用大鼠缺血模型观察预防性应用钙桔抗剂尼莫地平对大鼠缺血心肌和红细胞内钙的影响发现，缺血时大鼠心肌细胞、心肌组织和红细胞内均有钙积聚，红细胞膜钙泵活性下降；缺血前30分钟给予尼莫地平可使红细胞内钙恢复至正常水平，红细胞膜钙泵活性升高；心肌细胞和心肌组织内钙虽较缺血鼠降低，但仍高于对照组。提示：（1）缺血时细胞的钙内流可能是全身性的；（2）预防性应用尼莫地平可阻滞或减轻细胞内钙超载，同时还可保护细胞膜膜泵活性。     

Graves病患者血甲状旁腺激素、钙、磷、碱性磷酸酶基础值的观察

对照观察了28例Graves病患者及29名正常人血浆甲状旁腺激素、(PTH)血钙、血磷、碱性磷酸酶的基础值。Graves病组血碱性磷酸酶明显高于对照组,而PTH、钙、磷无显著差异。Graves病组血钙>2.75mmol/L者占21%,与某些文献大致相符。正常组血钙与PTH基础值间呈负相关,而Graves病组该两值间无相关,提示Graves病时血钙浓度的平衡调节中PTH以外的因素如甲状腺激素等可能对其影响较大。     

雌激素,胎盘生乳素,钙,磷与妊高征的关系

目的：探讨雌激素，胎盘生乳素，钙在妊高征发病中的作用及其相互关系，方法：采用放射免疫法及离心分析钙试剂，测定了４２例妊高征患者血清雌二醇，胎盘生乳素，钙，磷及尿钙，磷的含量，３４例同期门诊正常孕妇作为对照组，结果：轻度妊高征患者血清雌二醇明显增加（Ｐ〈０．０５）。重度妊高征患者血清胎盘生乳素显著减少（Ｐ〈０．０５），轻，中，重度妊高征患者血钙，尿钙含量显著降低（Ｐ〈０．０５，Ｐ〈０．０１，Ｐ〈０．     

取代四氢异喹啉衍生物的合成及其生物活性

粉防己碱有钙拮抗作用,临床试用于治疗高血压,其裂解产物钙拮抗作用降低,但有α-肾上腺素能受体拮抗作用,本文以裂解物为先导化合物设计合成了两类取代的四氢异喹啉衍生物Ⅲ及Ⅳ。初步药理试验表明:大部分化合物有α-肾上腺素能受体拮抗作用,少数化合物钙拮抗活性有所增强,其中Ⅲ_15,19对正常麻醉大鼠有一定的降压作用、Ⅳ_17,19对实验性动物心律失常有明显的保护作用。部分化合物量化计算表明:化合物与α₁-受体作用方式可能是形成电荷转移复合物。     

Functional role and histological demonstration of nitric-oxide-mediated inhibitory nerves in dog sphincter of Oddi

Abstract Nitric oxide (NO) plays an important physiological role in regulating gastrointestinal motility. Involvement of endogenous NO was evaluated in the response to non-adrenergic, non-cholinergic (NANC) nerve stimulation of the dog sphincter muscle of Oddi. Transmural electrical stimulation (TES), nicotine (10^?5M) and K⁺ (10 mM) produced only a relaxation in the sphincter muscle strips contracted with substance P, which was not potentiated by atropine. The TES-induced relaxation was abolished by tetrodotoxin (3 times 10^?7 M) and oxyhaemoglobin (1.6 times 10^?5 M), but not affected by atropine (10^?7 M), propranolol (10^?7 M), phentolamine (10^?7 M), indomethacin (10^?6 M), chole-cystokinin (CCK, 10^?8 M) and vasoactive intestinal polypeptide (VIP, 10^?8 M). The relaxation was also abolished by treatment with N^G-nitro-L-arginine (L-NA, 10^?5 M), an NO synthase inhibitor. Nicotine produced a transient relaxation, which was abolished by tetrodotoxin, hexamethonium (10^?5 M) and L-NA, but not affected by atropine and N^G-nitro-D-arginine (D-NA, 10^?5 M). The addition of K⁺ elicited a transient relaxation, which was abolished by tetrodotoxin and L-NA. The inhibitory effects of L-NA were antagonized by L-arginine (10^?3 M). The presence of neurons containing nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase was histochemically demonstrated in the sphincter of Oddi. These findings may indicate that TES, nicotine and K⁺ liberate NO from NANC inhibitory nerve which is involved in the relaxation of the dog sphincter of Oddi. The muscular tone does not seem to be regulated by cholinergic nerves under the experimental conditions used.