Results of animal experiments using an undulation pump total artificial heart: analysis of 10 day and 19 day survival

An undulation pump is a special rotary blood pump in which rotation of a brushless DC motor is transformed to an undulating motion by a disc in the pump housing attached by means of a special link mechanism. In the blood pump, a closed line between the disc and housing moves from the inlet to the outlet by this undulating disc motion, which sucks and pushes the blood from the inlet to the outlet. Because the same phenomena occurs at both sides of the disc, a continuous flow is obtained when the motor rotational speed is constant. The pump flow pattern can be easily changed from continuous flow to pulsatile flow by controlling the motor drive current pattern. A seal membrane made of segmented polyurethane protects the blood from invading the link mechanism as well as the motor. UPTAH is fabricated with two undulation pumps and two brushless DC motors. Its size is 75 mm in diameter and 80 mm long, and it has one of the great advantage of no compliance chamber required in the system. UPTAHs were implanted under cardiopulmonary bypass (CPB) into the chest cavities of 16 goats, each weighing between 41 and 72 kg. No anticoagulant and antiplatelet agent was used after the surgery. The left atrial pressure was automatically controlled to prevent its elevation and sucking of the atrial wall into the atrial cuff. The following results were obtained: (1) UPTAHs fit well into all the goats; (2) the longest survival was 19.8 days, the cause of death was bleeding from the aortic anastomosis; (3) No thrombus was observed in the blood pump despite no anticoagulant use. Hemolysis depended upon the length of CPB during surgery. When CPB time was within 2 hours, hemolysis level returned to baseline within a few days of the surgery. UPTAH is a promising implantable TAH, because of its small size and easy controllability.     

Increased mast cell density during the infection with velogenic Newcastle disease virus in chickens

In addition to their well-characterized role in allergic inflammation, recent data confirm that mast cells play a more extensive role in a variety of viral infections. The contribution of mast cells to Newcastle disease pathogenesis has not been investigated. We evaluated mast cell activity after Newcastle disease virus (NDV) infection in specific pathogen free chickens using cytochemical and immunocytochemical analyses. The results were as follows. Severe tissue damage was observed in the proventriculus, duodenum, jejunum and caecal tonsil, and NDV antigens were detected and presented extensively in these tissues. Second, in the NDV-infected group, the mast cell population was increased markedly in the proventriculus, duodenum, jejunum and caecal tonsil at 24, 48, 72 and 96 h after infection (P<0.01). However, very few mast cells were observed in those same tissues in the control. More intriguingly, the greatest number of mast cells was found in the proventriculus, which also showed the greatest level of NDV antigens. Third, the content of tryptase was significantly higher (P<0.01) in the NDV-infected group compared with the control from 24 to 96 h post infection). Furthermore, as an important protease released by mast cells, tryptase had a positive correlation with mast cell distribution. These data indicated that mast cells were involved in the response to NDV. Our results also suggested that the broad range of mast cell mediators might have a role in the pathology of Newcastle disease.     

Effect of anti-inflammatory medication on monocyte response to titanium particles

Cytokines produced by macrophages in the periprosthetic membranes surrounding joint replacements have been implicated as causal agents in osteolysis and prosthetic loosening. The present study characterizes the response of human peripheral blood monocytes to titanium particles. Monocytes were obtained from donated blood and were cultured in the presence of different-sized titanium particles. Exposure to titanium-aluminum-vanadium particles significantly changed the release of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 (IL-1), whereas there was no significant effect on the release of prostaglandin E(2) (PGE(2)). When monocytes were cultured with particles, the titanium alloy particles induced significantly more release of TNF-alpha and less IL-1 secretion. Ciprofloxacin inhibited production of TNF-alpha, IL-6, IL-1, and PGE(2) in human monocytes exposed to titanium particles. In contrast to ciprofloxacin, indomethacin was not a potent inhibitor of TNF-alpha production but potentiated IL-6 production in titanium-stimulated monocytes. Indomethacin had no effect on the production of IL-1 and was a potent inhibitor of PGE(2) production in titanium-stimulated monocytes. Pentoxifylline had an inhibitor effect on TNF-alpha production in titanium-stimulated monocytes. Pentoxifylline potentiated IL-6 and IL-1 production in monocytes exposed to titanium particles and had a biphasic effect on the PGE(2) production. The results of this study support our hypothesis that human monocytes release bone resorption mediators after in vitro exposure to TiAlV alloy particles. The results also demonstrate the differences of bone-resorbing mediators in response to different wear particle size. The pharmacologic agents (ciprofloxacin, pentoxifylline, and indomethacin) that can modulate the release of bone resorbing mediators such as PGE(2), TNF-alpha, IL-1, and IL-6 release from human monocytes. The results help to elucidate the differences in cellular response to wear particles but may not be directly transposed to the human situation.     

缺血性股骨头坏死患者血清透明质酸及层粘连蛋白的研究

为探讨细胞外间质主要成分透明质酸（ＨＡ）与层粘连蛋白（ＬＮ）在缺血性股骨头坏死（ＩＮＦＨ）中的生理病理过程及临床价值，采用放射免疫分析法对４５例不同病因的ＩＮＦＨ患者进行了血清ＨＡ与ＬＮ的定量分析，并与３０例正常人对照。结果显示，ＩＮＦＨ患者血清ＨＡ含量极显著地高于对照组（ｔ＝３－２９；Ｐ＜０－０１）。尤以激素性ＩＮＦＮ增高最为显著（ｔ＝３－６２；Ｐ＜０－０１）。ＩＮＦＨ患者ＬＮ含量亦明显高于对照组（ｔ＝２－８４；Ｐ＜０－０１）。同时，ＨＡ与ＬＮ含量增高与病程发展密切相关。故定量检测ＨＡ与ＬＮ可作为ＩＮＦＨ早期诊断及判断预后的良好指标     

Endoscopic sclerotherapy as compared with endoscopic ligation for bleeding esophageal varices.

BACKGROUND. Endoscopic sclerotherapy is an accepted treatment for bleeding esophageal varices, but it is associated with substantial local and systemic complications. Endoscopic ligation, a new form of endoscopic treatment for bleeding varices, may be safer. We compared the effectiveness and safety of the two techniques. METHODS. In this randomized trial we compared endoscopic sclerotherapy and endoscopic ligation in 129 patients with cirrhosis who had proved bleeding from esophageal varices. Sixty-five patients were treated with sclerotherapy, and 64 with ligation. Initial treatment for acute bleeding was followed by elective retreatment to eradicate varices. The patients were followed for a mean of 10 months, during which we determined the incidence of complications and recurrences of bleeding, the number of treatments needed to eradicate varices, and survival. RESULTS. Active bleeding at the first treatment was controlled by sclerotherapy in 10 of 13 patients (77 percent) and by ligation in 12 of 14 patients (86 percent). Slightly more sclerotherapy-treated patients had recurrent hemorrhage during the study (48 percent vs. 36 percent for the ligation-treated patients, P = 0.072). The eradication of varices required a lower mean (+/- SD) number of treatments with ligation (4 +/- 2 vs. 5 +/- 2, P = 0.056) than with sclerotherapy. The mortality rate was significantly higher in the sclerotherapy group (45 percent vs. 28 percent, P = 0.041), as was the rate of complications (22 percent vs. 2 percent, P less than 0.001). The complications of sclerotherapy were predominantly esophageal strictures, pneumonias, and other infections. CONCLUSIONS. Patients with cirrhosis who have bleeding esophageal varices have fewer treatment-related complications and better survival rates when they are treated by esophageal ligation than when they are treated by sclerotherapy.     

当归对大鼠肺β-受体数目的影响

建立了用放射性配基测定肺组织β-受体数目的方法,并探讨了当归对其影响。结果表明:当归与~3H-DHA没有竞争性结合,对正常大鼠、低氧大鼠肺组织β-受体数均无明显影响。提示当归缓解低氧性肺动脉高压不是通过改变肺β-受体数目而实现的。     

Prevalence of neutralizing antibodies to adenoviral serotypes 5 and 35 in the adult populations of The Gambia, South Africa, and the United States

One of the major limitations of the use of adenoviruses as gene therapy vectors is the existence of preformed immunity in various populations. Recent studies have linked failure of adenoviral gene therapy trials to the presence of antiadenoviral neutralizing antibodies (NAb). Understanding the distribution and specificity of such antibodies will assist in the design of successful recombinant adenoviral gene therapies and vaccines. To assess the prevalence of NAb to adenovirus serotypes 5 and 35 (Ad5 and Ad35), we analyzed serum samples from adult immunocompetent individuals living in The Gambia, South Africa, and the United States by using a neutralization assay. Serum samples were incubated with A549 lung carcinoma cells and adenoviruses encoding enhanced green or yellow fluorescent proteins; results were analyzed by fluorescence microscopy and flow cytometry. Using this technique, we found a high prevalence of NAb against Ad5 in Gambian, South African, and U.S. subjects at both low and high titers. Conversely, all subjects displayed a low prevalence of NAb to Ad35; when present, anti-Ad35 NAb were seen at low titers. Because of the ability of adenoviruses to elicit systemic and mucosal immune responses, Ad35 with its low NAb prevalence appears to be an attractive candidate vector for gene therapy applications.     

抗体包被对红细胞变形性影响的研究

作者对抗体包被的红为性进行研究，发现抗体包被改变了红细胞的变形性，在我们研究的抗体量范围内，抗体量越多，红细胞的变形性越小，作者从血液流变学的角度对上述结果作了讨论，并提出了通过测定其对红细胞变形性的影响来比较准确地标定抗体效价的可能性。     

针刺对实验性脑缺血作用机理的研究进展

缺血性脑血管疾病是一个非常复杂的病理生理过程 ,是多种机制共同作用的结果。本文从针刺对实验性脑缺血在脑组织形态学改变、血液流变学、脑微循环等方面的研究进展作一综述。     

Towards cellular receptors for prions

Transmissible spongiform encephalopathies (TSE) are attributed to the conversion of the cellular prion protein (PrP(c)) into an abnormal isoform (PrP(sc)). This can be caused by the invasion of living organisms by infectious particles, or be inherited due to mutations on the PrP(c) gene. One of the most intriguing problems of prion biology is the inability to generate the infectious agent in vitro. This argues strongly that other cellular proteins besides those added in test tubes or found in cellular preparations are necessary for infection. Despite recent progress in the understanding of prion pathology, the subcellular compartments in which the interaction and conversion of PrP(c) into PrP(sc) take place are still controversial. PrP(c) interacts with various macromolecules at the cell membrane, in endocytic compartments and in the secretory pathway, all of which may play specific roles in the internalisation of PrP(sc) and conversion of PrP(c). A specific interacting protein required for the propagation of prions was originally proposed as a prion receptor, and later referred to as a ligand, a cofactor, protein X, or a partner. However, current studies indicate that PrP(c) associates with multi-molecular complexes, which mediate a variety of functions in distinct cellular compartments. It is proposed that a deeper understanding of the mechanics of such interactions, coupled to a better knowledge of the corresponding signalling pathways and ensuing cellular responses, will have a major impact on the prevention and treatment of TSE.