干扰素诱导跨膜蛋白抗病毒机制研究进展

干扰素诱导跨膜蛋白（IFITM）是一类新型抗病毒细胞防御分子,其在人体组织细胞中普遍表达,主要定位于质膜、内体及溶酶体中,这些部位是病毒侵入细胞的主要靶点。IFITM通过抑制病毒与宿主细胞间的膜融合,从而限制多种病毒侵染,包括埃博拉病毒、流感病毒、严重急性呼吸综合征（SARS）冠状病毒、登革热病毒、西尼罗病毒和寨卡病毒等。虽然,IFITM已经被证明可以抑制8个病毒科数十种病毒,而且其主要抑制病毒进入阶段的融合过程,但IFITM抗病毒机制尚未明确。近年来IFITM的抗病毒作用及其机制已成为相关领域的研究热点。现就IFITM抗病毒谱及抗病毒机制研究进展作一综述。     

IFITM3在原发性肝癌中的表达及其对MMP-9调控效应

目的:探讨干扰素诱导跨膜蛋白3(IFITM3)在原发性肝癌中的表达及作用。方法:用免疫组化与Western blot检测60例肝癌组织及对应癌旁组织中IFITM3以及基质金属蛋白酶9(MMP-9)蛋白的表达;构建IFITM3小干扰RNA片段(psilencer3.1-sh IFITM3)转染肝癌Hep G2细胞,用实时荧光定量PCR及Western blot法、CCK8法、Transwell试验和划痕试验分别检测细胞转染后IFITM3和MMP-9 m RNA及蛋白表达、增殖能力以及侵袭与迁移能力的变化。结果:与癌旁组织比较,肝癌组织中IFITM3与MMP-9的蛋白的阳性表达率与表达量均明显升高(81.67%vs.13.33%;88.33%vs.8.33%,均P0.05);psilencer3.1-sh IFITM3转染后,Hep G2细胞IFITM3和MMP-9的m RNA与蛋白表达水平、细胞增值率均明显降低,穿膜细胞数明显减少,划痕融合速率明显减慢。以上定量指标间的差异均有统计学意义(均P0.05)。结论:原发性肝癌中IFITM3表达增高,高表达的IFITM3可能通过调控MMP-9的表达而促进肝癌细胞的增殖、侵袭和迁移。     

干扰素诱导跨膜蛋白3在肝癌中的表达及功能研究

目的:探讨干扰素诱导跨膜蛋白3(IFITM3)在原发性肝癌中的表达及意义。方法:收集55例配对的肝癌与癌旁组织标本,分别用免疫组化和Western blot检测组织标本中IFITM3蛋白的表达,并分析IFITM3表达与肝癌患者临床病理因素的关系;用IFITM3干扰片段转染在肝癌Hep G2细胞后,观察肝癌细胞侵袭迁移能力的变化。结果:免疫组化结果显示,IFITM3蛋白在肝癌组织中的阳性表达率明显高于癌旁组织(88.2%vs.23.5%,P0.05),低/中分化的肝癌组织中阳性表达率高于高分化的肝癌组织(80.0%vs.8.3%,P0.05);Western blot结果显示,肝癌组织中IFITM3蛋白表达量明显高于癌旁组织(1.2 399 vs.0.9 565,P0.05);IFITM3表达量与门静脉癌栓形成、肿瘤大小、TNM分期有关(均P0.05)。Hep G2细胞转染IFITM3干扰片段后,侵袭、迁移能力均明显减弱。结论:IFITM3在肝癌中表达升高,且其升高程度与肝癌细胞的侵袭、迁移能力密切相关,提示IFITM3在肝癌的恶性进展中起了重要作用。     

诱导表达人IFITM3的293细胞株的建立及其对H1N1型流感病毒侵染作用

目的建立诱导表达IFITM3蛋白的293细胞株,为进一步研究人IFITM3对H1N1型流感病毒侵染的作用及其分子机制提供细胞模型。 方法构建IFITM3/pcDNA5/FRT/TO expression vector质粒及诱导表达细胞株,建立HN1型流感病毒假病毒评价系统,利用蛋白印迹（Western blot）和荧光素酶报告基因对筛选的诱导表达细胞株功能进行检测。 结果建立的293诱导表达细胞株能够很好表达目的蛋白,且诱导表达出来的IFITM3蛋白使H1N1型流感假病毒感染率下降97%（t = 38.08、P < 0.001）,使水泡性口炎假病毒（VSVpp）感染率下降68%（t = 54.56、P < 0.001）,而阴性对照组小鼠白血病假病毒（MLVpp）感染率（t = 1.282、P = 0.2208）和拉沙假病毒（LASVpp）感染率（t = 0.4814、P = 0.6377）无显著影响。 结论IFITM3蛋白诱导表达细胞株可以显著抑制H1N1型流感病毒感染,为进一步深入研究IFITM3抑制流感病毒感染的作用机制和分子机理提供了细胞模型和实验基础。     

Pygo2与肿瘤的研究进展

Pygopus2(Pygo2)是2002年发现的,为Wnt信号通路中β-catenin的下游功能蛋白.已有研究证明,Pygo2通过Wnt信号通路参与人类多种疾病的发生发展,尤其是肿瘤性疾病.目前发现其具有调控组织发育、转录共激活及染色质重塑作用,并且与多种恶性肿瘤有密切关系.了解Pygo2蛋白在生长发育中的作用及肿瘤调控中的机制对认识肿瘤发生和演进、临床诊断及治疗有十分重要的意义.深入研究Pygo2在肿瘤发生发展中的作用有助于找到新的靶点,从而为肿瘤治疗提供新的方法.     

肿瘤抑制基因P53研究进展

抑癌基因P53与人类肿瘤发生的关系十分密切,是细胞癌基因中研究最为广泛的基因之一,并被science杂志评为1993年度明星分子[1].约50%的肿瘤可检测出P53基因突变,是所检测到的最常见的基因改变[2].经多年的研究,对P53基因的结构有了明确的认识,功能研究也取得重要进展.P53与多种基因之间存在相互调节的作用[3].对P53的作用机制研究无论对肿瘤的诊断或是基因治疗都具有重要意义. 1 功能及作用特点 P53是一种抑癌基因,野生型的P53蛋白在细胞内的含量低,半衰期短,故免疫组化法很难检测到,而突变的P53蛋白在细胞内的含量高,半衰期长,可用免疫组化法检测到.野生型的P53蛋白位于人类第17号染色体短臂上,可通过使DNA受损细胞发生凋亡而阻止肿瘤的发生,具有抑制肿瘤发生的作用,对细胞的增殖有一个正调控作用.突变型P53蛋白,则对细胞的增殖有一个负调控作用,反而引起细胞的恶性增生及癌变[4].P53基因及其编码产物的变化是人类恶性肿瘤中最常见的分子改变,随着结构生物学的序列→空间结构→功能中心法则的推出,国外开始在肿瘤中着眼于P53蛋白三维空间结构改变的研究[5].     

胃癌组织IFITM1表达与临床及预后价值的探讨

目的 探讨胃癌组织中干扰素诱导跨膜蛋白-1(IFITM1)的表达在胃癌侵袭转移过程中的作用及预测胃癌患者预后的价值.方法 采用免疫组化方法检测68例胃癌组织和27例距癌组织5cm以上胃大部切除黏膜组织中IFITM1的表达情况.同时评估IFITM1表达与临床病理因素(年龄、性别、Lauren's分型、肿瘤分化程度、肿瘤浸润深度、淋巴结转移和临床分期)之间的关系.用Kaplan-Meier法及单因素和多因素分析来评估胃癌患者术后生存率.结果 胃癌组织中IFITM1阳性表达率为85.3%(58/68),与距癌组织5cm以上胃大部切除黏膜组织中的表达阳性率(22.2%)比较,差异有统计学意义(P<0.01).IFITM1阳性表达率与Lauren's分型(P=0.026)、肿瘤分化程度(P=0.033)、淋巴结转移(P=0.001)、肿瘤浸润深度等因素(P=0.041)有关.IFITM1阳性表达率与年龄、性别、肿瘤大小和临床分期无显著性相关.胃癌患者的生存分析显示,IFITM1阴性组,低表达组和高表达组生存率之间差异有统计学意义(P=0.011).结论 IFITM1高表达与胃癌的浸润和转移密切相关,可以作为预测胃癌预后的一个生物学指标.     

IFITM1在胰腺癌中的表达及对胰腺癌细胞生物学行为的影响

背景与目的:干扰素诱导的跨膜蛋白1(IFITM1)是一种在淋巴细胞中转导同型黏附信号的膜复合物,在胰腺癌组织中表达量异常,但是其在胰腺癌中的作用机制则仍不清楚,因此,本研究初步探讨IFITM1的表达对胰腺癌细胞生物学行为的影响.方法:用Western blot法检测78例胰腺癌患者(32例转移,46例未转移)的癌组织和...     

Sp蛋白家族及其表达对胰腺癌的重要作用

Sp1蛋白(specificity protein 1)是第一个为人类所识别与克隆的转录因子,该蛋白分布广泛,具有与特定序列DNA结合并对多种基因进行激活的功能.近年来,与Sp1蛋白结构类似,功能相关的多种蛋白相继被识别与克隆,并被称为Sp蛋白家族.该文就业已发现的Sp蛋白种类、分布、染色体定位、蛋白结构、发挥激活功能的机制,以及近期研究发现Sp蛋白家族成员Sp1、Sp3、Sp4在胰腺癌细胞中的重要作用进行综述.     

干扰素诱导跨膜蛋白3、半乳糖凝集素-7和半乳糖凝集素-9表达与胸中段食管鳞癌改良Ivor-lewis术后淋巴结转移性复发的关系

目的探讨胸中段食管鳞癌(ESCC)干扰素诱导跨膜蛋白3(IFITM3)、半乳糖凝集素-7(Galectin-7)和Galectin-9表达及与改良Ivor-lewis术后淋巴结转移性复发的关系。方法改良Ivor-lewis手术治疗的胸中段食管癌病人91例,采用免疫组织化学法(IHC)检测肿瘤组织及癌旁正常组织中IFITM3、Galectin-7、Galectin-9表达情况,并分析其与术后淋巴结转移性复发的关系。结果 ESCC病灶组织中IFITM3、Galectin-7表达量高于癌旁组织,Galectin-9表达量低于癌旁组,差异有统计学意义(P0.05);ESCC病灶组织中IFITM3、Galectin-7、Galectin-9阳性表达率分别为57.14%、65.93%和60.44%,癌旁组织分别为13.19%、5.49%和89.01%,两组比较差异有统计学意义(P0.05)。随着TNM分期的升高,IFITM3、Galectin-7的阳性表达率也明显升高(P0.05)。术后3年内有37例(40.66%)淋巴结复发性转移,TNM分期、IFITM3和Galectin-7过表达、Galectin-9欠表达是淋巴结转移性复发的独立危险因素(P0.05)。结论 IFITM3、Galectin-7过表达和Galectin-9欠表达参与了胸中段ESCC的发生及发展,且与改良Ivor-lewis术后淋巴结转移性复发密切相关。     

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.     

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.     

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.     

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.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.