心脏瓣膜钙化在慢性肾脏病患者中的流行病学研究

目的 调查CKD不同分期患者瓣膜钙化的患病率及特点,了解影响CKD患者瓣膜钙化的可能因素。方法 回顾性分析2008年1月至2010年12月广东省人民医院肾内科CKD患者的心脏彩色B超和临床资料。患者分成CKD1-5期、5D期6个组。采用Logistic回归分析与瓣膜钙化相关的因素。结果 1550例CKD患者中,瓣膜钙化者有180例（占11.6%）,瓣环钙化（60%）多于瓣叶钙化（40%）。CKD1-5D期瓣膜钙化患病率依次为：0.6%、3.1%、8.9%、6.8%、4.4%和28.8%。CKD-5D期瓣膜钙化现象随透析龄的延长而增多。Logistic回归分析结果显示,与CKD心脏瓣膜钙化相关的危险因素包括年龄、血钙、iPTH、中重度瓣膜关闭不全、左室肥厚、进入维持性血液透析及伴有心血管合并症。结论 并非所有CKD都易合并瓣膜钙化,其在CKD1-2期非常少见,一旦进入维持性血液透析阶段,合并瓣膜钙化者明显增加。因此,瓣膜钙化的风险需要在CKD人群里分层评估,应重视筛查CKD-5D期患者的瓣膜钙化情况及可调控因素的综合干预。     

防钙化的人工心脏生物瓣膜实验研究和临床应用

我们首次应用环氧氯丙烷化学改性戊二醛处理的猪主动脉瓣，牛心包瓣和猪心包瓣，经家兔皮下移植和犬心内移植后钙定性，定量研究，结果证实均能明显减轻生物瓣钙化，并保持较好的组织结构和抗张强度，免疫学测试阴性，并发现猪心包组织比牛心包薄，柔韧度好，钙含量低，抗张强度较好是一种较好的单瓣叶组织材料，临床应用亦收到较好效果。     

珠三角地区血液透析患者代谢性酸中毒与心脏瓣膜钙化的相关关系——多中心横断面研究

目的:探讨维持性血液透析（maintenance hemodialysis,MHD）患者代谢性酸中毒与心脏瓣膜钙化的相关关系。方法:选择2019年7月1日至9月30日在珠三角地区10家血液净化中心行MHD大于3个月的患者纳入该多中心横断面研究,应用心脏彩超检查分为非心脏瓣膜钙化组和心脏瓣膜钙化组,记录人口学特征、透析次...     

心脏瓣膜钙化与骨质疏松

本文对４０例５０及５０岁以上中老年人伴有心脏瓣膜钙化的病人做骨密度检查，结果显示瓣膜钙化（心脏退行性变）的病人骨密度低于正常对照组又高于ＢＭＤ减低组，提示心脏退行性变病人的ＢＭＤ与正常ＢＭＤ呈负相关而与骨密度减低组病人呈显著正相关。简要讨论骨质疏松、软组织钙化、骨质增生之间可能的内在联系。     

左旋咪唑预防生物心脏瓣膜钙化的实验研究

近年来研究发现，生物心脏瓣膜钙化与碱性磷酸酶(AKP)密切相关，戊二醛处理的牛心包的死亡细胞仍有AKP活性，移植后能促使宿主迅速吸收AKP并沉积于生物瓣中；钙化抑制剂中Al3^ 、Fe3^ 等能作用于AKP存在部位。左旋咪唑为AKP特异性抑制剂，在抑制生物瓣表面AKP活力的同时，也有可能抑制和(或)延缓生物瓣钙化过程。本研究初步观察AKP特异性抑制剂左旋咪唑对兔体内牛心包片钙化的抑制作用。     

60岁以上病人心脏瓣膜替换术

从１９９０年１月至１９９５年１２月,我院为４３例６０岁以上病人行人工瓣膜替换术,占同期心脏瓣膜替换手术的４％（４３／１０７３）,疗效满意,现报告如下。临床资料本组男２６例,女１７例;年龄６０～６７岁;体重４４～７５ｋｇ。其中风湿性心脏病２８例,先天性...     

透析病人的获得性心脏瓣膜钙化

近十年来，透析病人的获得性心脏瓣膜钙化已越来越多地被发现，并引起重视，二尖瓣钙化的发生率约４０％，主动脉瓣钙化的发生率约２８－５５％，其中约１０％合并有瓣膜狭窄，钙化的发生和血钙、磷尤其是钙磷乘积的升高有关，亦和继发性甲旁亢和维持透析时间相磁，并对其发展及防治进行了分析。     

透析病人的获得性心脏瓣膜钙化

近十年来，透析病人的获得性心脏瓣膜钙化已越来越多地被发现，并引起重视。二尖瓣钙化的发生率约４０％，主动脉瓣钙化的发生率约２８－５５％，其中约１０％合并有瓣膜狭窄。钙化的发生和血钙、磷尤其是钙磷乘积的升高有关，亦和继发性甲旁亢和维持透析时间相关。并对其发展及防治进行了分析     

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.     

The multiply injured child

Blunt trauma is the principal cause of childhood death in many developed countries. This review outlines the differences between adults and children with respect to resuscitation and treatment of orthopaedic injuries in a child with polytrauma. Recent advances in techniques of fracture stabilization are reported.     

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.     

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.     

Development of Selective Low-Density Lipoprotein (LDL) Apheresis System: Immobilized Polyanion as LDL-Specific Adsorption for LDL Apheresis System

Abstract: Low-density lipoprotein (LDL) is widely recognized as one of the major risk factors for developing coronary heart diseases. Despite intensive development of LDL-lowering drugs, there still exist those patients with refractory hyperlipidemia whose plasma LDL levels are not sufficiently lowered by drugs. LDL apheresis, direct removal of plasma LDL from circulating blood, is thought to be the most promising treatment for such refractory patients. Various techniques, such as the use of an im-munoadsorbent utilizing an anti-LDL antibody, have been used in an attempt to achieve the selective removal of LDL. However, none were widely used because of complications, poor selectivity, and so forth. To establish a safe and effective LDL apheresis system, we chose a synthetic affinity adsorbent as the LDL-removing device. Synthetic polyanion compounds were used as the affinity ligands for LDL adsorbent to simulate the anion-rich sequence of LDL binding sites in the human LDL receptor. Among various polyanion compounds, those polyanions with sulfate or sulfonate groups and hydrophilic backbone were found to have strong affinity for LDL. In contrast, polyanions with carboxyl groups showed poor affinity. Dextran sulfate (DS) was selected as the affinity ligand of LDL adsorbent for its high affinity and low toxicity. The influence of its charge density and molecular weight on its affinity for LDL was suitable. The affinity rapidly increased as the charge density increased, then, reached a constant value. Little affinity was found for either the DS monomer (glucose sulfate) or DS with a molecular weight higher than 10⁴ daltons whereas DS with molecular weights in the midrange showed strong affinity. DS with a midrange molecular weight was immobilized on cellulose hard gel to give LDL adsorbent clinical application. The adsorbent demonstrated an excellent selectivity for LDL and very low density lipoprotein (VLDL) in vitro. Adsorption of high-density lipoprotein and major plasma proteins was almost negligible. Additional study of the LDL-binding mechanism revealed that DS directly interacts with positively charged sites on LDL, which demonstrates that the nature of the interaction is the same as that of LDL receptor. An LDL adsorption column (Liposorber) packed with an LDL adsorbent and polysulfone hollow-fiber plasma separator (Sulflux) was developed as an efficient LDL apheresis system. Clinical investigation proved that this system is capable of intensively lowering the plasma LDL level without affecting major plasma components.     

Artificial organs 2010: a year in review

In this Editor's Review, articles published in 2010 are organized by category and briefly summarized. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, and the International Society for Rotary Blood Pumps, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level."Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide such meaningful suggestions to the author's work whether eventually accepted or rejected and especially to those whose native tongue is not English. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, Wiley-Blackwell, for their expert attention and support in the production and marketing of Artificial Organs. In this Editor's Review, that historically has been widely received by our readership, we aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. We look forward to recording further advances in the coming years.     

Avaliação do clube de revista de anestesiologia por meio de mudanças semânticas

Background and objectives

The interactive approach of a journal club has been described in the medical education literature. The aim of this investigation is to present an assessment of journal club as a tool to address the question whether residents read more and critically.

Methods

This study reports the performance of medical residents in anesthesiology from the Clinics Hospital – University of São Paulo Medical School. All medical residents were invited to answer five questions derived from discussed papers. The answer sheet consisted of an affirmative statement with a Likert type scale (totally disagree–disagree–not sure–agree–totally agree), each related to one of the chosen articles. The results were evaluated by means of item analysis – difficulty index and discrimination power.

Results

Residents filled one hundred and seventy three evaluations in the months of December 2011 (n = 51), July 2012 (n = 66) and December 2012 (n = 56). The first exam presented all items with straight statement, second and third exams presented mixed items. Separating “totally agree” from “agree” increased the difficulty indices, but did not improve the discrimination power.

Conclusions

The use of a journal club assessment with straight and inverted statements and by means of five points scale for agreement has been shown to increase its item difficulty and discrimination power. This may reflect involvement either with the reading or the discussion during the journal meeting.