胰岛素样生长因子在骨生长,修复及改建中的作用

胰岛素样生长因子是骨组织细胞的极其重要的局部调节因子之一。一方面，通过内分泌、自分泌或旁分泌方式刺激成骨细胞的分化、增殖及其基质的形成，促进骨生长与修复；另一方面，通过介导作用，调节成骨细胞和破骨细胞泊分化形成及其功能活性，在骨改建偶联过程中发挥着重要的作用。     

同型半胱氨酸在多囊卵巢综合征中的研究进展

多囊卵巢综合征(PCOS)是女性常见的内分泌疾病,主要以排卵障碍、卵巢呈多囊样改变和高雄激素血症为特征。同型半胱氨酸(Hcy)是在蛋氨酸循环期间形成的含硫氨基酸,最新发现高同型半胱氨酸血症(HHcy)与PCOS密切相关,影响着PCOS的卵母细胞质量、高雄激素血症、胰岛素抵抗(IR)和高胰岛素血症,并且是其远期并发症如不良妊娠结局、心血管疾病、妊娠糖尿病的潜在危险因素。本文综述近年Hcy与PCOS的相关研究,旨在为PCOS临床诊断和治疗提供新的依据。     

胰岛素样生长因子1对2型糖尿病合并骨质疏松中骨钙素表达的影响

随着流行病学的调查研究发现,2型糖尿病患者与健康人群相比,其罹患骨折事件的发生率明显增高,所以骨质疏松及骨折等并发症需引起2型糖尿病患者的足够重视。在分子机制层面的研究显示,2型糖尿病合并骨质疏松的发生可能与胰岛素样生长因子1、葡萄糖毒性、硬骨素、骨钙素及氧化应激等多种代谢途径的改变有关。胰岛素样生长因子1是骨形成的调节因子,在调节成骨细胞和破骨细胞介导的骨骼重建过程中起着重要的作用。骨钙素是由成骨细胞产生的一种非胶原蛋白,能够反映成骨细胞的活性,常作为骨形成和骨转换的特异性指标。有研究显示,胰岛素样生长因子1以浓度依赖方式刺激骨钙素的合成增加,本文试就胰岛素样生长因子1对2型糖尿病合并骨质疏松中骨钙素表达的影响做一综述,探讨在2型糖尿病合并骨质疏松患者中胰岛素样生长因子1与骨钙素之间的相关性,以期对2型糖尿病合并骨质疏松患者能够进行早期诊断及治疗,预防骨折事件的发生,提高患者生活质量。     

良性乳腺疾病(综合报道)

一、良性乳腺疾病的内分泌学说/Dogliottl L//World J Surg.-1989,13(6).-674～679乳腺是最复杂的内分泌靶器官之一,其良性病变为:(1)局灶性,如纤维腺瘤、脂肪瘤、导管扩张等,与内分泌失衡的关系不大;(2)弥漫性和囊肿,统称为纤维囊性乳腺病,则与内分泌密切有关.(一)催乳激素:催乳激素可促进乳腺发育、分泌系统分泌以及乳腺免疫系统的成长,并具激发和维持乳腺分泌的功能.已知催乳激素不是单一的激素,而由不同分子量和各种免疫反应与生物活力性能的肽复合物组成,其受体具有高吸附力的膜.过去十年中,已发现纤维囊性乳腺病患者的催乳激素分泌有变化,但一     

胰岛素样生长因子-1与成骨细胞

胰岛素样生长因子-1(IGF-1)是一个由70个氨基酸残基组成的单链多肽,由3个二硫键相连,分子量为7600。胰岛素样生长因子-1和生长介素C是同一部分,受垂体生长激素的控制。胰岛素样生长因子-1是各种组织细胞有丝分裂原,包括成纤维细胞、成骨细胞、平滑肌细胞等,对成骨细胞有中等促进有丝分裂作用。调节了动物细胞周期G1期的活动,并具有胰岛素样作用。胰岛素样生长因子-1是骨骼细胞分泌的重要生长因子,以自分泌、旁分泌的形式调节成骨细胞的功能。以下就胰岛素样生长因子-1基因构成、骨骼分布特点及其对成骨细胞作用等作一综述。     

应激时β—内啡肽与糖代谢

应激反应致机体内分泌代谢改变已受到普遍重视。应激性代谢失常最显著的改变是高血糖、组织对葡萄糖利用率下降。一般认为胰岛素分泌减少,分解性代谢激素活动增高是其关键性因素。多年来,我们对上腹部手术病人内分泌激素进行了研究。结果表明:应激状态时机体胰岛素分泌功能并无降低,但儿茶酚胺,泌乳素等分泌升高;同时看到β-内啡肽(β-endorphin;β-EP)释放增多。本文将着重介绍手术应激状态下β-EP对糖代谢的影响。     

胰岛素生长因子—1与成骨细胞

胰岛素样生长因子 - 1(ＩＧＦ - 1)是一个由 70个氨基酸残基组成的单链多肽 ,由 3个二硫键相连 ,分子量为 760 0。胰岛素样生长因子 - 1和生长介素Ｃ是同一部分 ,受垂体生长激素的控制。胰岛素样生长因子 - 1是各种组织细胞有丝分裂原 ,包括成纤维细胞、成骨细胞、平滑肌细胞等 ,对成骨细胞有中等促进有丝分裂作用。调节了动物细胞周期Ｇ1期的活动 ,并具有胰岛素样作用。胰岛素样生长因子 - 1是骨骼细胞分泌的重要生长因子 ,以自分泌、旁分泌的形式调节成骨细胞的功能。以下就胰岛素样生长因子 - 1基因构成、骨骼分布特点及其对成骨细胞作用…     

男性生殖内分泌研究进展

男性生殖活动主要受下丘脑-垂体-性腺轴的调节,下丘脑、垂体和睾丸所分泌的激素一直是男性生殖生物学研究的热点。近年来发现睾丸除接受下丘脑-垂体激素的调节外,其内部还存在一个局部调节系统,过去一直认为仅是睾丸激素靶器官的前列腺也具有内分泌功能。目前男性生殖内分泌的研究极为活跃,一些研究的结果十分令人鼓舞。一、下丘脑在下丘脑分泌的众多激素中,对生殖活动来说,促性腺激素释放激素(GnRH)无疑是最重要的。分泌GnRH的神经分泌细胞主要位于视前区与结节区(弓状核)。GnRH的分子结构已经搞清楚,它是个10肽。现在又搞清了GnRH前体的分子结构,它是由92个氨基酸残基组成,氨基端(N端)     

性激素结合球蛋白在多囊卵巢综合征中的研究进展

多囊卵巢综合征(PCOS)是女性常见的内分泌疾病,主要以排卵障碍,卵巢呈多囊样改变和高雄激素血症为特征。性激素结合球蛋白(SHBG)主要作用是结合睾酮和雌激素,调节性激素在血中的浓度。本文对SHBG基因表达水平与PCOS,SHBG水平和胰岛素抵抗(IR)、高雄激素血症、2型糖尿病、代谢综合征(MS)、妊娠糖尿病、乳腺癌和子宫内膜癌等远期并发症的相关性进行综述,以期为PCOS的诊断提供一定参考,为临床治疗提供指导。     

梗阻性黄疸患者血清IGF-1变化的临床意义

胰岛素样生长因子 (IGF)是胰岛素源同系肽类 ,为分子量 7KD的单一链多肽 ,并由多种组织细胞合成和分泌 ,既是内分泌激素又是旁分泌激素 ,能调节多种细胞的生长增殖和分化 ,它们分为IGF 1和IGF 2。IGF 1是基础性生长介素 ,含 70个氨基酸 ,分子量为 76 4 6D。为探讨IGF 1在恶性梗阻性黄疸中的意义。我们对恶性梗阻性黄疸、良性梗阻性黄疸及胆石症患者IGF 1等的血清浓度进行检测 ,报告如下。资料与方法1.临床资料 :本组资料选择 2 0 0 1年 11月至 2 0 0 2年 9月我院普外科收治的梗阻性黄疸 5 6例 (剔除伴有胆道炎症和其它炎症的患者 )…     

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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.