石骨症并颈椎后纵韧带骨化1例报告

正石骨症又名Albers Schonberg病,是由破骨细胞数目减少或功能缺陷导致的一种以骨吸收障碍为主的罕见遗传性代谢性骨病,发生率约为1∶100 000,且具有一定的地区性~([1])。其典型的临床特征为骨密度增高、骨骼畸形~([2])。石骨症患者因骨脆性增加,骨组织弹性降低,骨折的发生率较高,且骨折后骨不愈合的发生率较高,因此既往文献主要涉及石骨症并四肢骨折的处理~([2])。又由于石骨症患者以骨吸收障碍为主,因此     

共育体系中成骨细胞和破骨细胞生物学特性观察

目的建立成骨细胞和破骨细胞的体外共育体系,观察在此体系中成骨细胞和破骨细胞生物学特性的变化,探讨成骨细胞和破骨细胞间的相互作用。方法取髂骨松质骨,Ⅱ型胶原酶消化,分次获得成骨细胞和破骨细胞。建立培养上清相通但二者互不接触的成骨细胞-破骨细胞共育模型。以细胞增殖(MTT法)、碱性磷酸酶(ALP)活性代表成骨细胞的成骨活性,以抗酒石酸酸性磷酸酶(TRAP)活性、骨吸收陷窝面积代表破骨细胞的破骨能力,检测共育对成骨细胞和破骨细胞生物学特性的影响。结果成骨细胞呈饱满的梭形,ALP染色阳性;破骨细胞呈多核,TRAP染色阳性,可以吸收骨质形成骨陷窝。当成骨细胞与破骨细胞共育后,其MTT法OD值(0.60±0.08)较单独培养时(0.36±0.03)明显提高(P=0.000);其ALP活性(23.37±2.48)u/mg较单独培养时(18.33±0.34)u/mg明显提高(P=0.000)。破骨细胞与成骨细胞共育后,形成骨吸收陷窝的平均面积犤(6.55±0.34)×10-2犦μm2较单独培养时犤(5.15±0.17)×10-2犦μm2明显增大(P=0.000)。结论共育体系中成骨细胞和破骨细胞的功能相互促进,为骨组织代谢的体外研究提供了可靠的模型。     

成骨细胞吞噬金黄色葡萄球菌在骨感染中的作用

骨的重建是骨组织在成骨与破骨间一个连续、协调的平衡过程.成骨细胞与破骨细胞参与此过程,破骨细胞主要通过酸化作用和释放溶酶体酶使骨吸收;成骨细胞则具有两个主要功能,一是合成细胞外基质成分(主要是Ⅰ型胶原)参与骨形成,二是产生细胞因子调控破骨细胞的形成或活性[1-4].     

骨保护蛋白及配体与破骨细胞

破骨细胞对骨量的维持起重要作用,它的发育、成熟信号是由成骨细胞传递的。当受到骨吸收因子作用时,成骨细胞表达骨保护蛋白配体分子,与破骨前体细胞膜上的核因子κB受体激活子结合,使之分化、成熟为破骨细胞。而成骨细胞旁分泌的骨保护蛋白分子,则作为伪受体与核因子κB受体激活子竞争结合骨保护蛋白配体,从而抑制破骨细胞的生成。骨保护蛋白配体-核因子κB受体激活子-骨保护蛋白组成了破骨细胞分化的信号传导通路,对它的认识有助于临床治疗代谢性骨病。     

废用性骨质疏松症发病机制研究进展

骨重建是由破骨细胞和成骨细胞调节,废用性骨质疏松症正是骨重建失衡的结果。破骨细胞和成骨细胞之间的生物偶联因素与力学有关。破骨细胞吸收骨质形成“小腔”,导致局部应力集中,成骨细胞募集并成骨,这可能是长期制动导致废用性骨质疏松症的原因。此外,某些神经细胞产生的相关肽及神经递质,如降钙素基因相关多肽、P物质可以调节成骨细胞和破骨细胞的分化,在维持骨密度方面发挥着重要作用。     

骨细胞对破骨细胞形成和功能的影响

破骨细胞的骨吸收作用和成骨细胞骨形成作用的交替进行维持了骨量的平衡。破骨细胞可以选择性吸收损伤部位的骨质,其激活和定位机制目前还未阐明。近年来的研究认为骨细胞是感知骨环境的基本单位,而且骨细胞还可以将所感知的信号传递给其它骨细胞,骨衬细胞,成骨细胞及破骨细胞等。对骨细胞和破骨细胞的研究中发现骨细胞可能在破骨细胞的激活和定位中起到了重要的作用,但是具体机制还有待研究。     

前列腺素E2转导力学信号对骨形成的影响

骨细胞对流体剪切力、压力、磁场力、重力等作出重要生物信号反应之一是释放大量激素,其中前列腺素E2的影响作用十分显著。成骨细胞在受到力学刺激后膜表面的蛋白多糖迅速接收信号、微管剪切应力增大及细胞产生变形,使得成骨细胞释放一氧化氮和前列腺素E2增加。前列腺素E2通过对破骨细胞前体细胞表达的核因子-κB受体活化因子配体进行调控,刺激破骨细胞分化,抑制其凋亡,还可与细胞中其他细胞因子相互调节来维持成骨细胞与破骨细胞的平衡,最终实现其对骨形成的作用。     

破骨细胞介导炎症性骨丢失的研究进展

破骨细胞起源于骨髓的多潜能干细胞,破骨细胞的数量和功能决定了关节破坏与骨丢失的严重程度,而炎症本身并不介导关节破坏和骨丢失。炎症性关节的滑膜成纤维细胞产生大量的炎症因子,如肿瘤坏死因子-α(TNF-α)和白介素-1(IL-1)。这些炎症因子不仅诱发炎症反应,而且通过促进核因子κB受体激活子配体,间接或直接增加破骨细胞的生成,并促进其功能,从而将炎症反应与局部骨丢失及损坏联系在一起。本文综述了近年来关于TNF-α、IL-1及破骨细胞靶疗法在破骨细胞介导的炎症性骨丢失过程中的研究进展。TNF-α通过促进外周血破骨细胞前体细胞的分化直接影响关节局部成熟破骨细胞的最终数目,而IL-1主要通过延长成骨细胞的寿命及调控破骨细胞骨架的重组来增加其骨吸收能力。抑制破骨细胞生长及功能的破骨细胞靶疗法在治疗炎症性骨丢失和关节损伤等方面日益得到重视。     

成骨细胞与破骨细胞间接共培养研究进展

在骨代谢过程中,成骨细胞形成新骨,破骨细胞吸收旧骨,一旦成骨细胞介导的骨基质形成和破骨细胞介导的骨吸收失衡,则会导致骨质疏松症等危害人类健康的疾病产生。因此,不同研究者致力于开发模拟体内环境的成骨细胞与破骨细胞体外共培养模型,以进行骨代谢相关疾病的研究。间接式共培养是通过物理方式将成骨细胞与破骨细胞分隔,使二者可以进行细胞间的交流而不接触,可以针对单一的细胞进行分析,在药物筛选及研究方面,具有高通量和经济便捷等独特的优势,本文对成骨细胞和破骨细胞的间接共培养技术进行归纳和总结。     

细胞因子与溶骨增强

骨转换包括破骨细胞骨吸收和随后发生的成骨细胞骨形成的过程 ,成骨细胞与破骨细胞数量、活性和存活均受全身激素及局部因子的影响 ,尤其是骨髓微环境中的细胞因子对骨转换起重要作用。破骨细胞起源于骨髓造血干细胞 ,具体地说 ,起源于粒细胞 /巨噬细胞集落形成单位 (CFU-GM) ,其形成包括由 CFU-GM经过分裂增殖形成单核破骨细胞前体 (增殖阶段 ) ,后者融合形成多核巨细胞 ,此为不成熟的破骨细胞 (分化阶段 ) ,再经活化后形成成熟的破骨细胞 ,成熟的破骨细胞贴附于骨表面并极化 ,分泌酸和蛋白酶进行溶骨 ,最后破骨细胞凋亡。溶骨增强包括…     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.