多普勒超声诊断移植肾排斥反应与病理检查及肾功能指标的对比分析

目的：以病理活检结果为金标准，评估多普勒超声检查对移植肾排斥反应的诊断价值。方法：选择2003—01/2006—12在中国医科大学附属第一医院器官移植科行肾移植并在术后行超声检查的患者176例，均知情同意。①实验分组：根据术后移植肾功能分为2组，移植肾功能不良组78例，其中30例次行病理活检；移植肾功能正常组98例。②实验方法及评估：对患者移植肾行多普勒超声检查，参数选择峰收缩期流速、平均舒张期流速、阻力指数及血管显示率。血管显示率的评估标准（0～5级）：0级为肾动脉及其远侧血管未显示；5级为肾各级血管均显示良好。以病理活检结果为金标准，分别选取阻力指数=0．7，0．75，0．8，0．85为诊断界值进行诊断试验。结果：169例患者进入结果分析，脱落7例。①峰收缩期流速、平均舒张期流速不呈正态分布，无法作为肾功能评价指标。30例次病理活检中共有28例次被确诊为排斥反应，急性排斥反应15例次，慢性排斥反应13例次。②肾功能正常组患者中血管显示率5级者占63．30％，4级者占36．73％。肾功能不良组患者中血管显示率4级者占41．03％，3级者占46．15％，2级者占10．30％，1级者占2．60％。③移植肾功能不良组患者阻力指数显著高于移植肾功能正常组（P〈0．01）。移植肾功能不良组患者移植肾功能恢复后阻力指数显著低于移植肾尚未恢复时（P〈0．01），其中99％以上的患者△（阻力指数）≥0.20。④界值阻力指数=0．75的诊断试验的敏感性、特异性和准确性最高，均达到100％。结论：当移植肾血管阻力指数升高至0．75以上，特别是同一患者自身对照升高超过0.2以上和或血管显示率低于4级，结合临床表现和生化结果，提示可能出现移植肾排斥反应。     

体外分离培养人脐静脉内皮及内皮下间充质干细胞

目的:建立人脐静脉内皮及内皮下间充质干细胞体外培养和扩增的方法,探讨其生物学特性,建立间充质干细胞体外培养扩增体系。方法:实验于2006-04/2006-09在辽宁医学院解剖学实验室完成。解剖细胞培养室为无菌百级培养间。正常健康产妇顺产或剖宫产的新生儿脐带由辽宁医学院附属第一医院提供,产妇及其家属均知情同意,并经医院伦理委员会批准。实验方法:①体外分离和培养贴壁细胞:无菌条件下取正常健康产妇分娩或剖宫产脐带,将其用预热PBS充分洗涤去血渍后,从脐静脉一端插入留置针,用预热PBS冲净静脉腔血后,用止血钳夹闭另一端,注入经预热至37℃的Ⅰ型胶原酶,置于37℃水浴箱中消化,30min后放出胶原酶,并用PBS冲洗血管腔,收集消化液和冲洗液,400r/min离心10min,吸弃上清液,重悬于M199培养基(含体积分数为0.15的胎牛血清,2mmol/L谷氨z酰胺,2μg/L碱性成纤维细胞生长因子,100U/mL青霉素,100U/mL链霉素)。以5×108L-1密度接种于6孔培养板中,置于37℃、体积分数为0.05的CO2饱和湿度培养箱中培养,48h后全量换液,以后每3d全量换液。待细胞80%融合时,0.25%胰酶消化,按1×108L-1传代培养。②间充质干细胞生长曲线的测定:取传代培养细胞,按2×107L-1密度接种于24孔培养板内,每天取3孔,将细胞消化计数,连测8d,绘制间充质干细胞生长曲线。③间充质干细胞表面抗原检测:在24孔塑料培养板内放置无菌的盖玻片,每孔中种植108L-1第2代细胞悬液1mL。采用免疫细胞化学方法进行细胞表面抗原检测。结果:①间充质干细胞的形态学观察:接种的细胞48h后细胞完全贴壁生长,其镜下形态有呈椭圆形、多角形的内皮细胞以及呈梭形的成纤维样细胞,有的形成漩涡状生长的集落。②间充质干细胞生长曲线的分析:传代培养的潜伏期约为24～36h,细胞倍增时间约为30～36h,对数增殖期约为二三天,对数增殖期后第5天进入平台期。③间充质干细胞表面抗原特性:免疫细胞化学分析结果显示,间充质干细胞表面抗原cd166、cd44阳性,而vWF阴性,说明分离获得的细胞具有间充质干细胞的特点。结论:所建立的分离和培养方法可获取人脐静脉黏附细胞中一组独特的细胞群,具有间充质干细胞的生物学特性。     

The efficacy of subcutaneous recombinant human erythropoietin in the correction of phlebotomy-induced anemia in autologous blood donors

The efficacy of subcutaneous recombinant human erythropoietin (rhEPO) (500 U/kg; administered twice a week during the 3 weeks before surgery) in the recovery of preoperative hemoglobin concentrations within a 3- week period was studied in 40 patients, each of whom donated 2 units (900 mL) of blood for their own use before total hip replacement surgery. Twenty autologous blood donors received rhEPO (EPO group) and 20 were not treated (control group). The initial hemoglobin concentration (14.0 +/− 1.0 g/dL [140 +/− 10 g/L]) was completely recovered before surgery (14.0 +/− 1.6 g/dL [140 +/− 16 g/L]) in the EPO group, while a decrease from 13.8 +/− 1.1 to 12.2 +/− 1.3 g per dL (138 +/− 11 to 122 +/− 13 g/L) was observed in the control group. The preoperative reticulocyte count showed more than sixfold increase in the EPO group, whereas a twofold to threefold increase was found in the control group. Serum ferritin concentration fell to 42 +/− 29 micrograms per L in the EPO group and to 54 +/− 35 micrograms per L in the control group. The postoperative serum erythropoietin concentration in the EPO group was significantly lower than that in the control group, but it did not differ from the pretreatment value and was attended by a higher hemoglobin concentration after surgery. Only transient flu-like symptoms were mentioned by patients who were treated with rhEPO. Changes in blood pressure or platelet count or other adverse events were not observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Respiratory insufficiency in neuronopathic and neuropathic disorders

Twenty-nine patients with a neuronopathic or neuropathic disorder were referred for assessment of respiratory insufficiency between 1978 and 1994. Diagnoses included spinal muscular atrophy (6), chronic idiopathic demyelinating neuropathy (4), Vialetto-van Laere syndrome (3), hereditary motor and sensory neuropathy (3) and a miscellaneous group (5). We also describe seven patients with Guillain-Barre syndrome (GBS) who required long-term ventilatory support for over 6 months to 7 years after the initial illness. Respiratory insufficiency occurred as a consequence of respiratory muscle weakness, impaired bulbar function and restrictive lung defects. In some groups presentation was with progressive nocturnal hypoventilation culminating in acute respiratory failure. Five patients with GBS or chronic idiopathic demyelinating neuropathy were weaned from ventilatory support up to 18 months after the initial illness. The remaining 24 patients required continuous or nocturnal ventilatory support using intermittent positive-pressure ventilation (13), negative pressure ventilation (4), nasal-mask-delivered intermittent positive-pressure ventilation (4), nasal-mask-delivered continuous positive-pressure ventilation (3), mouthpiece-assisted ventilation by day (2) and rocking bed (1). None have been weaned from support after a period of ventilation ranging from one month to 10 years. Eight patients have subsequently died.      

Adaptive differentiation of murine lymphocytes. IV. (Responder × Nonresponder) F(1) T cells can be taught to preferentially help nonresponder,rather than responder, B cells

Responses to the synthetic terpolymer L-glutamic acid, L-lysine, L-tyrosine (GLT) in the mouse are controlled by H-2-1inked Ir-GLTgenes. (Responder × nonresponder) F(1) hybrid mice, themselves phenotypic responders, can be primed with GLT to develop specific helper cells capable of interacting with 2,4-dinitrophenyl hapten (DNP)-primed F(1) B cells in response to DNP-GLT. Unlike the indiscriminant ability of F(1) helper T cells for conventional antigens (i.e. not Ir gene-controlled), which can help B cells of either parental type (as well as F(1)) equally well, GLT-primed F(1) T cells can only provide help under normal circumstances for B lymphocytes of responder parent origin; they are unable to communicate effectively with nonresponder parental B cells (1, and the present studies). The present studies reveal, however, that the induction of a parental cell-induced allogeneic effect during priming of F(1) mice to GLT actually dictates the direction of cooperating preference that will be displayed by such F(1) helper cells for B cells of one parental type or the other. Thus, F(1) T cells, primed to GLT under the influence of an allogeneic effect induced by parental BALB/c cells, develop into effective helpers for nonresponder A/J B cells, but fail to develop effective helpers for responder BALB/c B cells, and vice-versa. In contrast, F(1) T cells, primed to GLT under the influence of an allogeneic effect induced by either parental type, display significantly enhanced levels of helper activity for B cells derived from F(1) donors. These results are interpreted to reflect the existence of two interdependent events provoked by the allogeneic effect: one event augments the differentiation of GLT-specific helper T cells belonging to the subset corresponding to the opposite parental type; this would explain the development of increased helper activity provided to partner B cells of opposite parental type (as well as of F(1) origin). The second event, we postulate, involves the production of responses against the receptors which normally self-recognize native cell interaction determinants; this form of anti-idiotype response is restricted against self- recognizing receptors of the same parental type used for induction of the allogeneic effect, hence explaining diminished helper activity of such F(1) cells for partner B lymphocytes of corresponding parental type.     

In vivo regulation of the Vi antigen in Salmonella and induction of immune responses with an in vivo-inducible promoter

Salmonella enterica serovar Typhi, the agent of typhoid fever in humans, expresses the surface Vi polysaccharide antigen that contributes to virulence. However, Vi expression can also be detrimental to some key steps of S. Typhi infectivity, for example, invasion, and Vi is the target of protective immune responses. We used a strain of S. Typhimurium carrying the whole Salmonella pathogenicity island 7 (SPI-7) to monitor in vivo Vi expression within phagocytic cells of mice at different times after systemic infection. We also tested whether it is possible to modulate Vi expression via the use of in vivo-inducible promoters and whether this would trigger anti-Vi antibodies through the use of Vi-expressing live bacteria. Our results show that Vi expression in the liver and spleen is downregulated with the progression of infection and that the Vi-negative population of bacteria becomes prevalent by day 4 postinfection. Furthermore, we showed that replacing the natural tviA promoter with the promoter of the SPI-2 gene ssaG resulted in sustained Vi expression in the tissues. Intravenous or oral infection of mice with a strain of S. Typhimurium expressing Vi under the control of the ssaG promoter triggered detectable levels of all IgG subclasses specific for Vi. Our work highlights that Vi is downregulated in vivo and provides proof of principle that it is possible to generate a live attenuated vaccine that induces Vi-specific antibodies after single oral administration.     

Controlled delivery of ranitidine in the stomach using magnetic field

An attempt has been made to localize ranitidine loaded microspheres in the stomach by magnetic means. Since ranitidine undergoes metabolism by microbial enzymes in the intestine, it is ideal to localize the controlled drug delivery system within the stomach to get uniform release and absorption of the drug for the desired period. Gelatin magnetic microspheres loaded with 9.1, 17.9, 26.3 and 33.3% w/w of ranitidine hydrochloride were prepared by emulsification-cross linking technique. The formulated microspheres were characterized by magnetite content, particle size and in vitro drug release. The efficiency of microspheres to be localized in the stomach is tested in vivo in rats. The prepared microspheres were spherical and had a size distribution from 10 to 105 microm. The in vitro study revealed the capability of microspheres to release the drug over a period of 8 to 12 hours, depending on drug loading. The release was found to be diffusion controlled and followed fickian diffusion principle. The in vivo study showed the efficiency of microspheres to be retained in the stomach over a period of 8 hours.     

Longitudinal changes in serum lipids among HIV-infected men on highly active antiretroviral therapy

OBJECTIVE: The aim of the study was to describe longitudinal changes in serum lipids among HIV-infected men receiving highly active antiretroviral therapy (HAART) with long-term follow-up. METHODS: A total of 304 HIV-infected men who initiated HAART and who had serum lipid measurements prior to and for up to 7 years after HAART initiation were identified from the Multicenter AIDS Cohort Study (MACS). Mean levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were examined at biannual time-points. RESULTS: Significant lipid changes were seen within 0.5 years of HAART initiation but increases in TC (+1.09 mmol/L), LDL-C (+0.57 mmol/L), HDL-C (+0.16 mmol/L) and non-HDL-C (+0.91 mmol/L) reached peak levels 2-3 years after HAART initiation. Declines in serum TC, LDL-C and non-HDL-C in subsequent years occurred concurrently with a substantial increase in use of lipid-lowering medications (from 1% usage pre-HAART to 43% 6-7 years after HAART initiation) but the proportion of men who either were treated with cholesterol-lowering medication or had elevated cholesterol levels (>5.18 mmol/L) did not change during the 2-7-year interval after HAART. Mean HDL-C also decreased after 2-3 years and was low (<1.04 mmol/L) in 55% of HIV-infected men 6-7 years after HAART initiation. CONCLUSIONS: Atherogenic serum lipids increased early after the initiation of HAART, peaked at 2-3 years and remained high or required treatment thereafter. Low HDL-C levels persisted in the majority of men. The long-term effects of lipid abnormalities on cardiovascular risk and the effectiveness and toxicity of prolonged use of lipid-lowering medications in combination with HAART are not known.     

Cannabis and benzodiazepines as determinants of methadone trough plasma concentration variability in maintenance treatment: a transnational study

Purpose

To assess tobacco, alcohol, cannabis and benzodiazepine use in methadone maintenance treatment (MMT) as potential sources of variability in methadone pharmacokinetics.

Methods

Trough plasma (R)- and (S)-methadone concentrations were measured on 77 Australian and 74 Swiss MMT patients with no additional medications other than benzodiazepines. Simple and multiple regression analyses were performed for the primary metric, plasma methadone concentration/dose.

Results

Cannabis and methadone dose were significantly associated with lower 24-h plasma (R)- and (S)-methadone concentrations/dose. The models containing these variables explained 14–16% and 17–25% of the variation in (R)- and (S)-methadone concentration/dose, respectively. Analysis of 61 patients using only CYP3A4 metabolised benzodiazepines showed this class to be associated with higher (R)-concentration/dose, which is consistent with a potential competitive inhibition of CYP3A4.

Conclusion

Cannabis use and higher methadone doses in MMT could in part be a response to—or a cause of—more rapid methadone clearance. The effects of cannabis and benzodiazepines should be controlled for in future studies on methadone pharmacokinetics in MMT.