不同烧结温度对双相钙磷陶瓷颗粒材料介孔结构及其成骨性能的影响

目的通过体内外实验检测不同烧结温度下制备的不同介孔直径双相钙磷陶瓷（biphasic calcium phosphate，BCP）颗粒材料成骨能力差异，为筛选具备更好临床应用参数的 BCP 材料提供依据。方法将羟基磷灰石（hydroxyapatite，HA）及 β-磷酸三钙（β-tricalcium phosphate，β-TCP）以 8∶2 比例混合后，分别在 1 050、1 150 及 1 250℃ 下烧制 3 h 制备 3 种 BCP 材料（分别设为材料1、2、3），比表面积测试法（Brunauer-Emmett-Teller test，BET）测量材料的颗粒内部孔隙率及介孔直径、体积、面积，X 线衍射（X-ray diffraction，XRD）评估材料组成成份，扫描电镜观察材料微观表面形态。体外将第 3 代 SD 大鼠 BMSCs 与各材料共培养 7 d（分别设为 A、B、C 组），扫描电镜观察细胞黏附情况，鬼笔环肽染色观察 BMSCs 贴附于材料表面后的形态，细胞计数试剂盒 8 法检测细胞增殖活性。体内建立比格犬异位成骨模型：取 9 只比格犬，于每只犬双侧竖脊肌内制作 9 个肌袋，将肌袋随机分为 3 组（每组 3 个/只），A、B、C 组分别置入材料 1、2、3。术后 1、2、3 个月分别麻醉 3 只比格犬取材行 HE、Masson 及番红固绿染色，计算 BCP 间隙中的成骨面积比；行实时荧光定量 PCR（real-time fluorescence quantitative PCR，qRT-PCR）检测成骨相关基因 ALP、骨桥蛋白（osteopontin，OPN）、骨钙素（osteocalcin，OC）的表达。结果BET 检测示随烧结温度增加，颗粒内部孔隙率无明显变化，但介孔直径、体积及面积逐渐减小；XRD 检测示 3 种材料均可见 HA 及 β-TCP 两种 X 线衍射波；扫描电镜观察示 3 种材料表面有广泛分布的微孔，孔间有空隙相连。体外实验示 BMSCs 在 3 种材料表面黏附、增殖，B、C 组材料的细胞生物相容性优于 A 组。体内实验结果示，术后 2 个月开始 3 种材料颗粒孔隙内即可见明显的骨样组织沉积。各组成骨面积比随时间延长均增加，术后 2、3 个月 A 组成骨面积比显著高于 B、C 组，1 个月时显著高于 B 组（P<0.05）。qRT-PCR 检测示，A 组成骨相关基因表达在 2 个月时出现峰值，B、C 组各成骨相关基因表达随时间延长逐渐增加。术后 1 个月 A 组 ALP 和 OPN mRNA 相对表达量显著高于 B、C 组，术后 2 个月 A 组 OC mRNA 相对表达量显著高于 B、C 组，术后 3 个月 B、C 组 ALP mRNA 相对表达量及 B 组 OPN mRNA 相对表达量显著高于 A 组（P<0.05）；其余各时间点各组间比较各基因 mRNA 相对表达量差异均无统计学意义（P>0.05）。 结论不同烧结温度下制备的 BCP 材料，其介孔直径随温度增加而减小。不同介孔直径的 BCP 材料异位成骨能力存在差异，其中直径为 12.57 nm 的 BCP 材料能更早激活成骨基因，具备更强的成骨能力。介孔直径可作为一个优化 BCP 材料成骨能力的指标。     

锌指蛋白 A20 对兔腰椎间盘退变影响的实验研究

目的探讨锌指蛋白 A20 对兔腰椎间盘退变的影响。方法取 3 月龄新西兰大白兔 26 只，体质量 2.0～2.5 kg，经腹细针穿刺法制备 L_3、4、L_4、5、L_5、6 椎间盘退变模型，其中 24 只术后 4 周 MRI 检查明确造模成功，随机分为 4 组（n=6），于目标椎间盘中分别注射锌指蛋白 A20 过表达腺病毒（过表达 A20 组）、空载体腺病毒（空载体组）、PBS 液（对照组）、锌指蛋白 A20干扰腺病毒（干扰 A20 组）。于注射前 1 d 及注射后 1、2、3、6 d 行生物反应综合评分；注射后 2、4、8 周，各组行 MRI 检查并测量 T2 弛豫时间（T2 信号值）后，取材行阿利辛蓝染色观察椎间盘髓核细胞退变情况，免疫组织化学染色检测锌指蛋白 A20 以及椎间盘退变相关指标（Ⅱ型胶原、蛋白聚糖）的表达，Western blot 检测锌指蛋白 A20、NF-κB 结合蛋白［P65、磷酸化 P65（phosphate P65，P-P65）、Ⅱ型胶原、蛋白聚糖］、自噬相关蛋白［LC3 （LC3Ⅱ/LC3Ⅰ）、P62］以及炎症因子（TNF-α、IL-1β）的表达。 结果各组注射后各时间点生物反应综合评分均明显低于注射前 1 d（P<0.05）；注射后 6 d 干扰 A20 组评分明显低于其他组（P<0.05），其他组间比较差异均无统计学意义（P>0.05）。MRI 检测提示，注射后 2、4、8 周过表达 A20 组 T2 信号值均最高（P<0.05），2、4 周时干扰 A20 组最低（P<0.05），其余组间差异均无统计学意义（P>0.05）。阿利辛蓝染色显示，注射后 4 周过表达 A20 组蛋白聚糖含量最高（P<0.05）、干扰 A20 组最低（P<0.05）；8 周时过表达 A20 组蛋白聚糖含量显著高于其他组（P<0.05），其他组间比较差异无统计学意义（P>0.05）。免疫组织化学染色示，锌指蛋白 A20、Ⅱ型胶原、蛋白聚糖表达过表达 A20 组最高（P<0.05），干扰 A20 组上述蛋白表达最低（P<0.05）。Western blot 检测示锌指蛋白 A20、蛋白聚糖、Ⅱ型胶原、LC3 （LC3Ⅱ/LC3Ⅰ）蛋白相对表达量过表达 A20 组最高、干扰 A20 组最低，而 P-P65、TNF-α、IL-1β、P62 蛋白相对表达量过表达 A20 组最低、干扰 A20 组最高，与其他组比较差异均有统计学意义（P<0.05）；各组 P65 蛋白相对表达量差异均无统计学意义（P>0.05）。 结论锌指蛋白 A20 能通过抑制炎症反应，有效延缓兔腰椎间盘退变的进程。     

Einflu\ eines Β1-Rezeptorenblockers auf die Plasmaspiegel des atrialen natriuretischen Peptids bei Patienten mit essentieller Hypertonie unter Ergometerbelastung

Summary In order to investigate the behaviour of atrial natriuretic peptide (ANP) in untreated mild to moderate essential hypertension and the influence of blood pressure normalisation by a ₁-receptor blocker a study was conducted in groups of normotensive and hypertensive middle aged subjects. 10 normal subjects and 10 patients with essential hypertension (WHO I–II) without any medication and on betaxolol monotherapy were studied at rest and during graded exercise. In addition the response of ANP, cyclic guanosine monophosphate (cGMP) and the renin-aldosterone-system was investigated.Normal subjects and hypertensive patients did not differ in ANP levels at rest and also responded with a comparable exercise dependent increase at all workload levels. A steady decrease of ANP was noticed during the recovery period in both groups. After-blocker treatment in the hypertensive patients ANP concentrations significantly rose, both at rest and more pronounced during exercise. cGMP reacted in a similar way but showed a more inert response. A counter-regulatory behaviour between ANP and PRA or aldosterone, as seen under volume shifts, could not be detected. These findings demonstrate that plasma ANP is not altered in untreated essential hypertension. Increased ANP levels in ₁-blocker treatment may contribute to its blood lowering effect.

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Abkürzungsverzeichnis ANP atriales natriuretisches Peptid - ALD Aldosteron - C_In Inulin Clearance - cGMP zyklisches Guanosinmonophosphat - irANP immunoreaktives atriales natriuretisches Peptid - PAH Paraaminohippursäure - PRA Plasma-Renin-Aktivität - RAA-System Renin-Angiotensin-Aldosteron-System - RBF renaler Blutflu - RIA Radioimmunoassay - RVR renaler Gefä\widerstand     

Evidence for the existence of two forms of α2A-adrenoceptors in the rat

Summary The _2A-adrenoceptors in rat spleen, kidney, spinal cord and cerebral cortex were studied using [³H]-RX821002 radioligand binding. In the spleen, spinal cord and cerebral cortex, the ligand bound to saturable sites with a K _d of about 1 nmol/l and capacities of 134, 240 and 290 fmol/mg protein, respectively. Computer modelling competition curves for 39 drugs, including those for _2A-, _2B- or _2C-adrenoceptor selective drugs, indicated that the sites labelled by [³H]-RX821002 in the spleen consisted of a single population of _2A-adrenoceptors. However, the competition curves for guanoxabenz were definitely biphasic and resolved into two site fits, indicating that guanoxabenz was binding to both high affinity (K _d = 35 nmol/1) and low affinity (K _d = 8900 nmol/1) _2A-adrenoceptor sites in the proportions 57% and 43%, respectively. The K _d ^Sfor a number of ₂-adrenoceptor subtype selective drugs, measured in competition with [³H]-RX821002 in cerebral cortex and spinal cord, were highly correlated with those obtained in the spleen indicating their _2A-adrenoceptor nature. However, by contrast to the results with the spleen, the guanoxabenz competition curves for the spinal cord and cerebral cortex were monophasic and resolved only into one site fits, the K _d of guanoxabenz being about 4000 nmol/l for both tissues. Drug K _d ^Sfor kidney _2A-adrenoceptors were also determined using [³H]-RX821002. For nearly all drugs tested, the K _d ^Swere highly correlated with those found for the _2A-adrenoceptors in the other rat tissues. However, for guanoxabenz, the data indicated that it competed with [³H]-RX821002 at a single _2A-adrenoceptor site with a K _d of 39 nmol/1. When the rat _2A-adrenoceptor gene RG20 was transiently expressed in COS-7 cells and its ligand binding properties probed using [³H]-RX821002, the drug K _d ^Sobtained were also highly correlated with those found for the _2A-adrenoceptors in the spleen, cerebral cortex, spinal cord and kidney of the rat. For the RG20 encoded receptor, the guanoxabenz competition curves were steep and monophasic and modelled best into one site fits, with the Kd of guanoxabenz being 5200 nmol/1.It is suggested that guanoxabenz can differentiate between two forms of _2A-adrenoceptors in the rat: _2A1 and _2A2. The _2A1-form is present in the spleen and kidney where it shows a high apparent affinity for guanoxabenz. The _2A2-form shows a low apparent affinity for guanoxabenz and is present in the spleen, cerebal cortex and spinal cord. The _2A2-form of the rat ₂-adrenoceptor appears to be encoded by the RG20 gene. The _2A, and _2A2-adrenoceptor forms do not represent high and low affinity receptor forms for agonists because assays included EDTA, Gpp(NH)p and Na⁺, which eliminated the high affinity receptors for agonists.     

乳化剂OP存在下胶束增溶分光光度法测定水中镉

目的：用胶束增溶分光光度法测定水中镉的含量,并比较了乳化剂OP(聚乙二醇辛基苯基醚)和吐温-20(聚氧乙烯山梨醇酐单月桂酸酯)的胶束增溶作用。方法：分别以体积分数为10％OP和体积分数为10％吐温-20为增溶剂,以PAN(1-(2-吡啶偶氮)-2-萘酚)为显色剂,在555nm波长处测定水中镉络合物的吸光度。结果：相同条件下,同浓度的镉络合物用OP的吸光度值是吐温-20的1．6倍,用OP作乳化剂平均回收率为96．5％,平行样品的相对平均偏差为2．57％,标准曲线线性良好,回归系数r=0．999 9,ε=4．6×104L·mol-1·cm-1。结论：乳化剂OP的增溶作用优于吐温-20,此法测定水中痕量镉较好。     

The effects of d-cycloserine and MK-801 on the performance of rats in two spatial learning and memory tasks

The present study was undertaken to investigate the effects of modulation of the (NMDA) receptor on learning and memory. Thus, the performance of rats treated with d-cycloserine, a partial agonist at the glycine recognition site of the NMDA receptor complex, and MK-801, a noncompetitive NMDA receptor antagonist, either alone or concurrently were assessed in radial arm maze and water maze tasks. Administration of MK-801 (0.1 mg/kg, i.p.) impaired acquisition in the water maze (increased escape latency and distance) and working memory in the radial arm maze (increased re-entries) in rats. Moreover, in the radial arm maze, MK-801 disrupted locomotion (increased latencies and decreased arm entries per minute) and impaired the acquisition of reference memory (increased number of errors) performance of rats. d-Cycloserine (0.03, 0.3, 1.0, 3.0, 10 mg/kg, i.p.) had no effects on acquisition or memory performance of control or MK-801-treated rats in either of these tasks. However, d-cycloserine (0.03, 0.3, 3.0 mg/kg) reversed the MK-801-induced disruption in locomotion. Furthermore, 3.0 mg/kg d-cycloserine increased behavioral activity and also decreased the time needed to complete the task in control animals. To conclude, our results suggest that the consequences of NMDA receptor modulation on learning and memory processes and sensorimotor functions may be functionally different or have distinct anatomical locations.     

Periventricular- intraventricular hemorrhage in the premature infant- A historical perspective

The objective of this chapter is to trace the evolution of intraventricular hemorrhage in the premature infant highlighting the importance of the germinal matrix, a critical role for cerebral blood flow changes in the genesis of hemorrhage, clinical factors that increase the bleeding risk, and potential preventative strategies. In 1976, neuropathological studies demonstrated capillary rupture within the germinal matrix as the precursor of hemorrhage. In 1980, introduction of cranial ultrasound facilitated diagnosis of intraventricular hemorrhage. In 1979, loss of cerebral autoregulation in sick newborn infants was demonstrated. In the 1980’s, studies demonstrated the importance of intravascular factors in provoking hemorrhage. In 1983, the association of cerebral blood flow velocity fluctuations and subsequent hemorrhage was demonstrated. In 1994, antenatal steroids use to accelerate lung development was recommended. This was associated with an unanticipated reduction in hemorrhage. In the mid 1990’s early indomethacin administration was associated with a reduction of severe hemorrhage.     

Auswirkungen von Argon-Gasembolien während eines PneumoperitoneumsRID="*"ID="*"Die Studie wurde zum Teil gefördert von der DFG (Bo 1329/8–1)

Zusammenfassung. In einer experimentellen Studie wurde bei 10 Schweinen mit einem mittleren K?rpergewicht von 18,9 (15–24) kg eine intraven?se CO₂- oder Argon-Embolie mit 10, 20 und 30 ml Gas durchgeführt. Das invasive Monitoring zeigte bei der Gasembolie mit Argon im Gegensatz zur Gasembolie mit CO₂ einen st?rkeren Anstieg des pulmonal arteriellen Drucks (p < 0,001), einen st?rkeren Abfall des endexspiratorischen CO₂ (p < 0,01), des Herzminutenvolumens (p < 0,01) und des mittleren arteriellen Drucks (p < 0,01). In der Argon-Gruppe (n = 5) starben zwei Tiere nach 20 bzw. 30 ml Bolusgabe. Ein weiteres Tier konnte nach Gabe von 30 ml Bolus erfolgreich reanimiert werden. In der CO₂-Gruppe (n = 5) starb weder eines der Tiere noch war eine Reanimation erforderlich. Wenig l?sliche Gase wie Argon sollten in Situationen mit erh?htem Risiko einer Gasembolie nicht angewendet werden. ID=" Dr. T. Junghans Klinik f&uuml;r Allgemein-, Visceral-, Gef&auml;&szlig;- und Thoraxchirurgie Universit&auml;tsklinikum Medizinische Fakult&auml;t der Humboldt-Universit&auml;t Campus Charit&eacute; Mitte Schumannstra&szlig;e 20/21 D-10117 Berlin     

Acute interactions between -DOPA and the neurotoxic effects of 1-methyl-4-phenylpyridinium or 6-hydroxydopamine in mice

We have compared the effects of an i.p. pretreatment with L-DOPA (200 mg/kg) associated with benserazide (25 mg/kg) on neurotoxic effects of either 6-hydroxydopamine (6-OHDA) (50 microg, 10 microl per mouse) or 1-methyl-4-phenylpyridinium (MPP+) (17.5 microg, 10 microl per mouse). The striatal dopamine (DA) content, the vesicular monoamine transporter (VMAT2) density, as well as the hypothalamic norepinephrine (NE) content were measured 8 days after treatments. The L-DOPA-benserazide pretreatment worsened by 65% the 6-OHDA-induced depletion in striatal DA. On the contrary, it reduced by 42% the MPP+-induced depletion in striatal DA and by 54% the MPP+-induced decrease in VMAT2 density. It was noticed that the L-DOPA-benserazide pretreatment did not modify the marked decrease in hypothalamic NE content induced by 6-OHDA.     

Occupational induction of hypersensitivity after an accidental exposure to chloromethylisothiazolinone and methylisothiazolinone (CMI/MI) in an industrial worker.

A process worker in a paper chemical plant developed an immediate local dermal irritation and delayed bullous dermatitis due to induction of hypersensitivity following an accidental exposure to chloromethylisothiazolinone and methylisothiazolinone (CMI/MI) biocide. Contact allergy to the isothiazolinone mixture was confirmed by skin patch testing. The dermatitis healed in four weeks, and the worker was advised to avoid all CMI/MI containing products. In a one-year follow-up he did not present with any further skin symptoms. Preventive measures are important for avoiding induction of hypersensitivity to concentrated CMI/MI solutions in industrial workers.