胸腺内移植脾细胞延长大鼠移植肝存活的研究

探讨大鼠胸腺内移植供体脾细胞在建立特异性供体不反应性中的作用。ＴＪＲ／１大鼠作供体，ＳＤ大鼠为受体。切取供体鼠脾脏制成脾细胞悬液，注入到受体鼠胸腺内，此前两天受体鼠口服环孢素４０ｍｇ．ｋｇ＾－１．ｄ＾－１，胸腺内脾细胞移植前皮下注射地塞米松２５ｍｇ／ｋｇ。１０天后取同一供体肝脏进行原位肝移植，术后不用免疫抑制剂。     

胸腺内注射异基因抗原诱导同种异体肢体移植免疫耐受的实验研究

目的：探讨胸腺内注射异基因抗原对同种异体肢体移植存活的影响。方法：Wistar大鼠为供体,SD大鼠为受体。将SD大鼠随机分成4组,A组（自体肢体移植组）、B组（异体肢体移植组）、C组（异体肢体移植加用免疫抑制剂组）、D组（胸腺内注射组）。术后观察肢体的存活时间,术后7d进行组织学检查。结果：肢体存活时间C组和D组比较,差异无统计学意义（P〉0．05）,与B组比较,差异有统计学意义（P〈0．01）。组织学检查,D组优于B、C组（P〈0．05）。结论：胸腺内注射异基因抗原可诱导对异体肢体移植的特异性免疫耐受。     

细辛木脂素联合供者脾细胞对心脏移植大鼠免疫耐受的诱导效果

观察细辛木脂素联合供体脾细胞对同种异体心脏移植免疫耐受的诱导效果,为抗排斥药物的研究提供依据。方法:分别采用供体脾细胞、细辛木脂素(ＨＡＬ)和ＨＡＬ联合供者脾细胞预处理移植受体,然后行大鼠异位心脏移植术。根据实验各组移植心脏存活时间和混合淋巴细胞反应进行观察。结果:对照组、脾细胞组、ＨＡＬ组和ＨＡＬ＋脾细胞组的移植心脏存活天数分别为(６．８１±０．９７)ｄ,(７．２０±１．５５)ｄ,(１０．４０±２．７８)ｄ,(２７．６３±６．４６)ｄ,ＨＡＬ＋脾细胞组的移植心脏存活时间明显长于脾细胞组和 ＨＡＬ组(Ｐ＜０．０１);移植术后７ｄ和１４ｄ的混合淋巴细胞反应以ＨＡＬ＋脾细胞组的ＣＰＭ值为最低(Ｐ＜０．０１)。结论:细辛木脂素能够明显提高供体脾细胞所诱导的免疫耐受强度,显著地延长大鼠同种异移植体心脏的存活时间。     

抗淋巴细胞血清联合脾细胞促进异基因骨髓细胞形成嵌合体诱导免疫耐受

目的:探讨抗淋巴细胞血清(ALS)联合异基因脾细胞(SC)在促进异基因骨髓细胞移植诱导小鼠皮肤移植免疫耐受中的作用。方法:第-5～-3天,C57BL/6(H-2b)受体小鼠每天腹腔注入0.5 ml抗淋巴细胞血清(ALS),共3天。第0天,C57BL/6受体小鼠通过尾静脉输注均源自BALB/c(H-2d)的1×108脾细胞(SC)及2×107骨髓细胞(BMC)。第二天,受体鼠腹腔注入200 mg/kg的环磷酰胺(CP)。第六天进行从BALB/c到C57BL/6的尾-尾皮肤移植。每天观察移植皮片存活情况,共观察100天。并于骨髓细胞移植后30天、50天及70天对受体小鼠外周血进行嵌合体检查。结果:抗淋巴细胞血清和(或)异基因脾细胞的输注能促进异基因BMC的植入,并能延长移植皮片的存活时间。在30、50天及70天,SC BMC CP、ALS BMC CP及ALS SC BMC CP移植组受体小鼠体内能检测到供体骨髓源性细胞,ALS SC BMC CP移植组的嵌合率较高,随着时间推移,嵌合率下降,而且移植皮片存活时间与嵌合率具一定相关性。结论:抗淋巴细胞血清(ALS)联合异基因脾细胞能协助异基因BMC植入,形成嵌合体,促进免疫耐受的诱导,使移植皮片存活时间延长。     

MSCs修饰受体胸腺对异种心脏移植免疫排斥反应的作用研究

目的大鼠胸腺以豚鼠骨髓间充质干细胞进行修饰,然后行豚鼠到大鼠的异种心脏移植。研究以间充质干细胞修饰胸腺对异种移植心脏存活时间的影响。方法供体豚鼠和受体SD大鼠各20只随机分成四组,A组(对照组);B组(胸腺修饰IT组);C组(CVF组);D组(IT加CVF组)。观测指标:移植心脏存活时间,病理变化,供受体异种淋巴细胞毒性试验。结果供心平均存活时间:A组(23.20±6.14)min,B组(24.20±9.28)min,C组(335.40±49.23)min,D组(451.00±50.10)min。A与B组两组比较,差异无统计学意义(P>0.05)。C、D组平均存活时间较A、B明显延长,差异有统计学意义(P<0.05)。D组与C组组间比较差异有统计学意义(P<0.05)。供受体淋巴细胞反应,测得光密度值分别为:D组为(381.20±12.01),A组为(590.20±15.38),胸腺修饰组明显低于对照组,差异有统计学意义(P<0.05)。结论豚鼠到大鼠心脏异种移植中,豚鼠MSCs修饰大鼠胸腺,当克服HAR后可以延长供心存活时间,但并不能完全克服AVR的发生。     

吻合血管的移植胸腺免疫形态学观察

用光镜和电镜观察带血管吻合的移植胸腺免疫形态学变化。发现移植15周后的人胚胸腺在光镜下皮质、髓质结构消失，无胸腺小体，出现大量新生小血管及毛细血管。电镜下移植的胸腺上皮细胞胞浆内含有分泌颗粒和大小不等的囊泡，见有树突状细胞和肥大细胞。提示移植的胸腺小器官存活并具有分泌功能。认为宿主对供体移植耐受的产生和免疫排异与树突状细胞出现的数量有关，肥大细胞则可能起多能细胞因子源的作用，参与移植胸腔的微环境调节。     

MSCs修饰受体胸腺的异种心脏移植中Th2细胞的表达研究

目的研究胸腺修饰对异种移植免疫排斥反应的影响,探讨Th2细胞的作用。方法将供体豚鼠(20只)和受体SD大鼠(20只)随机分成四组,A组(对照组);B组(胸腺修饰IT组);C组(CVF组);D组(IT加CVF组),每组各10只,5只供体豚鼠,5只受体SD大鼠。观测指标:脾脏GATA-3,CCR3变化。结果脾脏GATA-3的表达,测得灰度值分别为:A组:80.718±1.650,B组:81.510±1.890,C组:166.160±7.360,D组:115.074±3.090;D组表达较C组弱,差异有统计学意义(P<0.05)。C组的脾脏GATA-3、CCR3免疫组化较D组表达明显增强。结论 Th2细胞的增殖通过豚鼠MSCs修饰大鼠胸腺被有效抑制,从而使大鼠IgG类诱生异种抗体的产生也受到抑制。     

大鼠同种异体心脏移植免疫耐受的特异性实验研究

目的：研究大鼠同种异体心脏移植免疫耐受的特异性。方法：建立大鼠异位心脏移植模型,应用抗淋巴血清（ALS）及／或胸腺内注射脾细胞抗原预处理受体,21天后进行心脏移植,经过心脏移植并产生免疫,耐受的受体鼠在心脏移植60天后再次接受供体鼠的皮肤移植。结果：同时应用ALS及胸腺注射脾细胞抗原组的移植心平均存活时间较其它组显著延长（平均＞72天）,移植的皮肤在移植心耐受组中平均存活7．4天即被排斥,这与未处理组的皮肤移植无判别,但移植皮肤的排斥并不影响移植的心脏。结论：同种异体心脏移植产生的特异性免疫耐受是胸腺内注射供体脾细胞和腹腔注射ALS共同作用的结果。胸腺预注射供体脾细胞并腹腔注射ALS诱导产生的免疫耐受有器官特异性及组织特异性,。     

大鼠胸腺内猪胰岛异种移植的实验研究

目的:观察胸腺内和肾包膜下胰岛移植对移植物存活时间的影响。方法:我们应用胰管内注射胶原酶的方法分离出猪胰岛为供体,以W istar糖尿病大鼠为受体,通过移植物的存活期来观察大鼠胸腺内及肾包膜下猪胰岛异种移植的效果。结果:单纯胸腺内移植的存活期(6.0±3.6)d,长于单纯肾包膜下组的(5.3±1.8)d。移植的同时加用抗大鼠胸腺淋巴血清(ATS),胸腺内移植+ATS的存活期为(21.7±9.1)d,明显长于肾包膜下移植+ATS组的(13.7±3.2)d。结论:胸腺可能为胰岛移植的理想部位,而且在诱导免疫耐受中具有重要作用。     

骨髓干细胞诱导大鼠心脏移植免疫耐受的实验研究

目的探讨注射供者的骨髓十细胞对大鼠异位移植心的影响。方法以wistar大鼠为供者．SD大鼠为受者,制作Wistar大鼠的骨髓干细胞．建立大鼠同种异体异位心脏移植模型。心脏移植术前2h经受者阴茎静脉注射骨髓干细胞0．3m1．心脏移植术后分别观察受者注射同一供者和无关供者的骨髓干细胞后移植心脏的存活时间;心脏停跳后取移植心做病理检查及免疫组织化学检测。结果心脏移植术前受者接受同一供者和无关供者的骨髓干细胞后,前者移植心脏存活时间延长,分别为（37．0±16．5）d和（9．5±2．4）d．两组比较,差异有统计学意义（P〈0．01）;且前者心肌出血、坏死程度更轻,心肌组织内IgM和IgG沉积更少。结论注射同一供者的骨髓干细胞能特异性减轻大鼠移植心脏的排斥反应．明显延长其存活时间。     

封闭血管内皮生长因子C对角膜淋巴管的抑制和对同种移植物存活的促进作用研究

目的:研究封闭血管内皮生长因子C对角膜淋巴管的抑制效果和同种移植物存活的影响。方法:将100只BALB/c小鼠随机分为正常对照组、移植对照组、血管内皮生长因子C抑制组,每组20只。正常对照组不作特殊处理,移植对照组、血管内皮生长因子C抑制组制作小鼠角膜移植模型,术后分别通过腹腔注射,正常组和移植组注射等剂量的生理盐水,血管内皮生长因子C抑制组使用单克隆抗VEGF-C抗体阻断VEGF-C,在术后第3,7,10,14d分别取材,角膜淋巴管显像特征性使用全组织包埋免疫荧光法,移植物的免疫排斥反应通过裂隙灯检查并进行排斥反应评分(RI),另外VEGF-C的表达通过免疫组化和即时PCR来检测。结果:正常对照组角膜无新生淋巴管;其余两组小鼠移植后有新生淋巴管从角膜缘发出,淋巴管计数(LVC)在第14d达峰值,移植组的淋巴管计数高于血管内皮生长因子C抑制组。RT-PCR和Western blotting检测结果显示,正常对照组有少量VEGF-C表达,移植对照组VEGF-C表达较正常对照组显著增多且在第14d达峰值(P<0.05);与移植对照组比较,血管内皮生长因子C抑制组VEGF-C表达降低(P<0.05),而血管内皮生长因子C抑制组VEGF-C表达高于正常对照组(P<0.05)。通过裂隙灯观察角膜通透性,分别计数不同组的小鼠移植存活量来评价封闭血管内皮生长因子C对同种移植物存活的影响。结论:封闭血管内皮生长因子C对角膜淋巴管有明显的抑制作用,能够显著增强同种移植物存活数量。     

Inhibition of Rat Splenocyte Proliferation with Methylprednisolone: In Vivo Effect of Liposomal Formulation

The effect of a liposomal formulation of methylprednisolone (MPL) on the inhibition of lymphocyte proliferation in spleen cells was investigated following IV dosing in rats. Liposomes do not alter the suppressive action of MPL when placed in lymphocyte culture. Rat splenocytes were found to have greater sensitivity to MPL (EC₅₀ = 7.9 nM) than do human peripheral blood lymphocytes (EC₅₀ = 28 nM). In vivo studies in rats utilized 2 mg/kg IV bolus doses of liposomal MPL compared to drug in solution. Animals were sacrificed at various times post-dosing until 120 h, spleen was excised and, after incubation of lymphocytes with PHA, splenocyte blastogenic responses were assessed by measuring cellular incorporation of ³H-thymidine. The suppressive effect of liposomal MPL in comparison with free drug was significantly prolonged (>120 h vs < 18 h). Inhibition effects versus time were described by a pharmacodynamic model using MPL concentrations in plasma as an input function. A nonlinear relationship was found between suppression of splenocyte proliferation and the concentration of bound glucocorticoid receptors in spleen. Only partial receptor occupancy accompanied complete lymphocyte suppression. The suppression of endogenous corticosterone in plasma for both treatments was similar with values from L-MPL rats returning to baseline after 24 h. These results demonstrate enhanced efficacy of local immunosuppression by targeting spleen with liposomal MPL.     

树突状细胞瘤苗预防接种联合吉西他滨治疗可提高胰腺癌小鼠模型的生存率

目的应用胰腺癌小鼠模型来研究吉西他滨是否可以提高树突状细胞瘤苗接种的疗效。方法 C57B L/6小鼠成功负载经紫外线辐射后的PanO2癌细胞后,从小鼠体内获得骨髓源性DCs然后经皮下给药。预防性接种的小鼠在PanO2癌细胞形成肿瘤威胁前接种瘤苗,每隔一周接种3次,治疗性接种于肿瘤形成可触及结节时开始。吉西他滨经腹腔给药,每周两次。结果预防性DC瘤苗接种可全面阻止皮下及原位肿瘤的发展并且可诱导肿瘤抗原特异性CTLs及免疫记忆。对于已形成皮下肿瘤的模型,治疗性DC瘤苗接种与吉西他滨同样有效(肿瘤威胁形成后58天生存率分别为14%和17%,对照组0%)。以上两种方法联合可显著提高带瘤小鼠的生存率(肿瘤威胁形成后58天生存率为50%)。树突状细胞瘤苗接种也可以预防静脉注射PanO2细胞后肺转移导致的死亡。结论:树突状细胞免疫治疗不仅可以成功地与吉西他滨联合治疗晚期胰腺癌,还能够有效地预防无瘤患者的肿瘤局部复发及转移。     

Post-mortem Survival of Hippuric Acid Formation in Rat and Human Cadaver Tissue Samples

1. A rapid and sensitive semi-micro method for the determination of hippuric acid formation by tissue samples in vitro is described and applied to the determination of the post-mortem survival of hippuric acid formation in rat and human cadaver tissue samples.

2. Hippuric acid formation survived in rat and human cadaver liver for at least 72 h when corpses were stored at 4°.

3. Hippuric acid formation was detected in human cadaver liver and kidney samples and was absent from brain, intestine, heart and lung.

4. Post-mortem liver samples from a case of acute pancreatitis failed to form hippuric acid as did kidney samples from a case of systemic lupus erythematosus with renal involvement.     

Interactive Effects of Three Structurally Different Polychlorinated Biphenyls in a Rat Liver Tumor Promotion Bioassay

Interactive effects between the non-ortho-substituted 3,3′, 4,4′,5-pentachlorobiphenyl (PCB126), the mono-ortho-substituted 2,3,3′,4,4′-pentachlorobiphenyl (PCB105), and the di-ortho-substituted 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) were studied in an initiation/promotion bioassay. Female Sprague–Dawley rats were injected with 30 mg/kg ip ofN-nitrosodiethylamine 24 h after partial hepatectomy. Five weeks later, weekly sc administrations of the three PCBs in 15 systematically selected dose combinations started. After 20 weeks of administration, the animals were killed and the livers were analyzed for areas expressing placental glutathione-S-transferase as a marker of preneoplastic foci. In addition, concentration of liver and kidney retinoids and plasma retinol was analyzed, as well as body and organ weights, plasma transaminases, and induction of hepatic cytochrome P450 1A1/2 (CYP1A1/2) and CYP2B1/2 activities. Data were analyzed with a multivariate method. At the doses applied in this study, weak antagonism was observed between PCB126 and PCB153 for effects on volume fraction of foci, number of foci/cm³, concentration of plasma retinol and liver retinoids, relative liver weight, and induction of CYP2B1/2 activity. Weak antagonism was also observed between PCB126 and PCB105 for effects on volume fraction of foci, number of foci/cm³, and plasma retinol concentration. No interactions other than pure additivity were observed between PCB105 and PCB153. Synergism was not observed within the dose ranges investigated in this study. Knowledge of interactive effects is important for risk assessment of environmental mixtures of dioxin-like compounds. Antagonism between congeners generally results in risk assessments that overestimate human risk. The significance to human risk assessment of the relatively weak antagonism observed in this study is however unclear, considering many other uncertainties involved in the toxic equivalency factor (TEF) concept. A change of the TEF concept for risk assessments of dioxin-like substances is not motivated based on the results of this study.     

川芎嗪对大鼠大脑皮层神经细胞的体外存活及其钙超载的影响

目的:研究川芎嗪对体外培养的大鼠大脑皮层神经细胞的保护作用及其钙超载的影响。方法:取出生1d内的乳鼠大脑皮层制成细胞悬液,接种于经多聚赖氨酸包被的培养板。于培养6d后,加入不同浓度的川芎嗪,继续培养1d,采用MTT比色法测量其存活细胞的吸收值,同时行NSE检查。采用激光扫描共聚焦显微镜(LSCM)技术检测药物对谷氨酸(500μmol·L-1)、KCl(50mmol·L-1)诱导培养6d的大脑皮层神经细胞内钙超载的影响,计算荧光强度变化率。结果:NSE检查结果表明,培养6d的存活细胞大部分均为神经元。MTT比色检查结果表明,川芎嗪浓度为1.6～200.0μg·mL-1时,存活细胞数均明显增加(P<0.05)。LSCM测定结果表明,100μg·mL-1川芎嗪能明显降低荧光强度变化率(P<0.01)。结论:川芎嗪能促进体外培养的大脑皮层神经细胞存活,且可抑制谷氨酸、KCl诱导的神经细胞内钙超载,这可能是其治疗缺血性脑血管病的作用机制。     

Promotion of noise-induced hearing loss by chemical contaminants

Recent studies have underscored the ability of a wide range of chemical agents to potentate noise-induced hearing loss. Given the ubiquitous nature of noise exposure particularly in many work settings, the high rate of noise-induced hearing loss, the limited degree to which auditory function can recover following damage to the inner ear, and the disparate chemical structures that appear capable of impairing hearing, this issue appears to have great public health significance. A compendium of chemicals known to potentiate noise induced hearing loss is presented along with a hypothesis that might explain at least one basis for potentiation of noise-induced hearing loss by certain chemical toxicants. The use of benchmark dose analysis to undertake a risk assessment for promotion of noise-induced hearing loss by both carbon monoxide and hydrogen cyanide is described.