The parameters of electron cyclotron resonance/radio-frequency hybrid hydrogen plasma adjusted by substrate arrangements

Hybrid hydrogen plasma was formed by biasing 13.56 MHz radio-frequency (rf) power on a substrate immersed in 2.45 GHz microwave electron cyclotron resonance (ECR) plasma. The influences of the substrate configuration on plasma characteristics were investigated. With increasing rf self-bias voltage, electron temperature, T(e), increases obviously in the case of the single-electrode substrate, whereas a slight change in T(e) was observed with the double-electrode substrate condition. Electron density rises almost with a same magnitude under both two substrate conditions. It exhibited that electron energy and density in ECR-rf hybrid mode could be adjusted independently by controlling rf discharge with favorable substrate configurations.

The antioxidant drink “effective microorganism-X (EM-X)” pre-treatment attenuates the loss of nigrostriatal dopaminergic neurons in 6-hydroxydopamine-lesion rat model of Parkinson’s disease

There is continued interest in the assessment and potential use of antioxidants as neuroprotective agents in diseases associated with increased oxidative stress, such as Parkinson's disease. The neuroprotective effect of a natural antioxidant drink, EM-X (a ferment derivative of unpolished rice, papaya and seaweeds with effective microorganisms), was investigated using the 6-hydroxydopamine (6-OHDA)-lesion rat model of Parkinson's disease. The nigrostriatal dopaminergic neurons were unilaterally lesioned with 6-OHDA (8 μg) in rats that were treated with a 10-times diluted EM-X drink (dilEM-X), standard EM-X drink (stdEM-X) or tap water for 4 days. Seven days post lesion, the integrity (no. of tyrosine hydroxylase positive cells (TH+ cells) in the substantia nigra pars compacta (SNpc)) and functionality (dopamine and its metabolites DOPAC and HVA content in the striata) of nigrostriatal dopaminergic neurons were assessed. In the vehicle-treated rats, infusion of 8 μg of 6-OHDA significantly reduced the number of TH+ cells in the SNpc as well as the levels of dopamine, DOPAC and HVA in the striata on the lesion side. The loss of TH+ cells, dopamine and HVA, but not the DOPAC levels, was significantly attenuated by stdEM-X pretreatment, but not by the dilEM-X pretreatment. There were no significant changes in the TH+ cells, or in the monoamine levels with the EM-X pretreatment per se, except for a small but significant fall in the levels of dopamine with the stdEM-X. The evidence presented supports the potential neuroprotective effects of stdEM-X drink, although its effect on dopamine levels needs further investigation.

Intestinal ischemia/reperfusion injury triggers activation of innate toll-like receptor 4 and adaptive chemokine programs

BACKGROUND

Ischemia/reperfusion injury (IRI) is a major problem in intestinal transplantation. Toll-like receptor 4 (TLR4) has been implicated as a possible link between the innate and adaptive immune systems, however little data exists regarding TLR4 in intestinal IRI. The goal of this study is to evaluate the involvement of TLR4 in intestinal IRI and to assess the effect on T cell related chemokine programs.

METHODS

C57BL6 mice underwent 100 minutes of warm intestinal ischemia by SMA clamping. Control WT mice underwent laparotomy without vascular occlusion. Separate survival and analysis groups were performed, and intestinal tissue was harvested at 1 hour, 2 hours, 4 hours, and 24 hours post-reperfusion. Analysis included histology, CD3 immunostaining, myeloperoxidase activity, Western blot, and PCR.

RESULTS

Survival was significantly worse in the IRI group vs control (50% vs. 100%). IRI caused severe histopathological injury including mucosal erosions and villous congestion and hemorrhage. Myeloperoxidase activity increased in a time-dependent manner after IRI (2.71 0.25 at 1 hour, 2.92 0.25 at 2 hours, 4 0.16 at 4 hours, 5.1 0.25 at 24 hours vs 0.47 0.11 controls, P < .05). Protein expression of TLR4 followed by NF-kappaB was increased after IRI. Additionally, mRNA production of IP-10, MIP-2, MCP-1, and RANTES was increased at all time-points, as was mRNA for ICAM-1 and E-selectin.

CONCLUSION

This study is the first to demonstrate increased expression of TLR4 and NF-kappaB after warm intestinal IRI. This detrimental cascade may be initiated by TLR4 via NF-kappaB signaling pathways, implicating TLR4 as a potential therapeutic target for the prevention of intestinal IRI.

Diannexin, a novel annexin V homodimer, protects rat liver transplants against cold ischemia-reperfusion injury

Ischemia/reperfusion injury (IRI) remains an important problem in clinical transplantation. Following ischemia, phosphatidylserine (PS) translocates to surfaces of endothelial cells (ECs) and promotes the early attachment of leukocytes/platelets, impairing microvascular blood flow. Diannexin, a 73 KD homodimer of human annexin V, binds to PS, prevents attachment of leukocytes/platelets to EC, and maintains sinusoidal blood flow. This study analyzes whether Diannexin treatment can prevent cold IRI in liver transplantation. Rat livers were stored at 4 degrees C in UW solution for 24 h, and then transplanted orthotopically (OLT) into syngeneic recipients. Diannexin (200 microg/kg) was infused into: (i) donor livers after recovering and before reperfusion, (ii) OLT recipients at reperfusion and day +2. Controls consisted of untreated OLTs. Both Diannexin regimens increased OLT survival from 40% to 100%, depressed sALT levels, and decreased hepatic histological injury. Diannexin treatment decreased TNF-alpha, IL-1beta, IP-10 expression, diminished expression of P-selectin, endothelial ICAM-1, and attenuated OLT infiltration by macrophages, CD4 cells and PMNs. Diannexin increased expression of HO-1/Bcl-2/Bcl-xl, and reduced Caspase-3/TUNEL+ apoptotic cells. Thus, by modulating leukocyte/platelet trafficking and EC activation in OLTs, Diannexin suppressed vascular inflammatory responses and decreased apoptosis. Diannexin deserves further exploration as a novel agent to attenuate IRI, and thereby improve OLT function/increase organ donor pool.

P-selectin knockout mice have improved outcomes with both warm ischemia and small bowel transplantation

AIM

To analyze the role of P-selectin in intestinal ischemia and reperfusion injury (IRI) using murine models.

METHODS

A model of warm IRI wherein the SMA was occluded for 100 minutes was undertaken in the following groups (10 mice per group): Group 1 (control) wild-type (WT) C57BL6, no treatment; Group 2: 0.4 mg/kg of r-PSGL1-lg 10 minutes before and after clamping; Group 3: PSGL KO mice. Survival was assessed at 7 days; the intestine was assayed for histopathology, apoptosis, myeloperoxidase (MPO), IL1, and TNF. A second model of cold IRI followed by intestinal transplantation (IT) was undertaken in the following groups (two mice per group): Group A WT --> WT: Group B PSGL KO --> WT (1-hour ischemia); Group C: PSGL KO --> WT (2 hour ischemia). Survival only was assessed.

RESULTS

Survival was 50% in group 1, 90% in group 2, and 100% in group 3. Graded histopathology and crypt apoptosis demonstrated significantly less injury in groups B and C. MPO was not different between groups. IL1 and TNF were significantly reduce in groups 2 and 3. Following IT, survival was <12 hours in group A, >7 days in group B, and <72 hours in group C.

CONCLUSION

This study clearly demonstrates the importance of P-selectin in warm and cold IRI in that the blockade of P-selectin using rPSGL1-lg or the absence of P-selectin using KO mice confers a survival advantage and reduction in tissue injury. The mechanism is unclear but appears to be independent of neutrophil infiltration.

Heavy chain ferritin acts as an antiapoptotic gene that protects livers from ischemia reperfusion injury

Heme oxygenase-1 (HO-1) is induced under a variety of pro-oxidant conditions such as those associated with ischemia-reperfusion injury (IRI) of transplanted organs. HO-1 cleaves the heme porphyrin ring releasing Fe2+, which induces the expression of the Fe2+ sequestering protein ferritin. By limiting the ability of Fe2+ to participate in the generation of free radicals through the Fenton reaction, ferritin acts as an anti-oxidant. We have previously shown that HO-1 protects transplanted organs from IRI. We have linked this protective effect with the anti-apoptotic action of HO-1. Whether the iron-binding properties of ferritin contributed to the protective effect of HO-1 was not clear. We now report that recombinant adenovirus mediated overexpression of the ferritin heavy chain (H-ferritin) gene protects rat livers from IRI and prevents hepatocellular damage upon transplantation into syngeneic recipients. The protective effect of H-ferritin is associated with the inhibition of endothelial cell and hepatocyte apoptosis in vivo. H-ferritin protects cultured endothelial cells from apoptosis induced by a variety of stimuli. These findings unveil the anti-apoptotic function of H-ferritin and suggest that H-ferritin can be used in a therapeutic manner to prevent liver IRI and thus maximize the organ donor pool used for transplantation.

Heme oxygenase-1 overexpression protects rat livers from ischemia/reperfusion injury with extended cold preservation

This study analyzes the effects and mechanisms of heme oxygenase-1 (HO-1)-mediated cytoprotection in rat livers exposed to cold preservation. In the first series, rats were pretreated with cobalt protoporphyrin (CoPP) or zinc protoporphyrin (ZnPP), HO-1 inducer and antagonist, respectively. Livers were stored at 4 degrees C for 24 h, and then perfused ex vivo for 2 h. Livers pretreated with CoPP had significantly higher portal venous blood flow and increased total bile production, as compared with the ZnPP group. This correlated with histologic (Banff) criteria of hepatocyte injury/liver function. In the second series, rat livers were stored at 4 degrees C for 24 h or 40 h, and then transplanted into syngeneic recipients. After 24 h of preservation, 80% of rats bearing CoPP-pretreated liver grafts survived 21 days (vs. 50% in controls). After 40h of cold preservation, liver transplant survival at day 1, 7 and 21 for the CoPP group was: 100%, 71% and 57%, respectively (vs. 50%, 50% and 33% in controls). This correlated with improved hepatic function/histologic (Suzuki) criteria of hepatocyte injury after HO-1 overexpression (immunohistology/Western blots) by infiltrating macrophages. This study documents the potential utility of HO-1-inducing agents in preventing ischemia/reperfusion injury resulting from prolonged storage of liver transplants.

[Sequencing-based typing of HLA-DPB1 and DQB1 exon 2 in patients with type 1 diabetes mellitus]

OBJECTIVE

To investigate the correlation between type 1 diabetes mellitus susceptibility and HLA-DPB1 and DQB1 genes in Shandong Han population.

METHODS

HLA-DPB1 and DQB1 genes analysis were performed by sequencing-based typing in 52 type 1 diabetes mellitus patients and 38 normal controls.

RESULTS

The frequency of DPB1*2201 in diabetics was significantly higher than that in controls(26.92% vs 5.26%, P<0.01), but the frequency of DPB1*0402 in diabetics was significantly lower than that in controls(11.54% vs 34.21%, P<0.01). The frequencies of DQB1*0201, *0303 and *0604 in diabetics were higher than those in controls (24.04% vs 10.53%, P< 0.01; 22.12% vs 6.58%, P<0.05; 19.23% vs 7.89%, P<0.05), while the frequency of DQB1*0301 in diabetics was significantly lower than that in controls (4.81% vs 25.00%, P<0.01).

CONCLUSION

DPB1*2201, DQB1*0201, *0303 and *0604 may be susceptible alleles, and DPB1*0402 and DQB1*0301 may be protective alleles in patients with type 1 diabetes mellitus.

Antisense TGF-beta2 immunotherapy for hepatocellular carcinoma: treatment in a rat tumor model

BACKGROUND

The overexpression of transforming growth factor-beta (TGF-beta) in hepatocellular carcinoma (HCC) appears to induce immunosuppression toward the tumor cells.

METHODS

A rat HCC cell line, Morris hepatoma rat cell line (MRH)-7777 (MRH), was transfected with antisense TGF-beta2 in pCEP-4 vector and used as immunotherapy against the development of wild-type tumors. An enzyme-linked immunosorbent assay (ELISA) confirmed that TGF-beta2 production was markedly lower for antisense modified cells as compared to wild-type tumor cells. Tumors were initiated by injecting MRH cells into the flanks of Buffalo rats. This was followed by biweekly vaccinations with irradiated MRH cells (unmodified, pCEP-4 alone, or antisense TGF-beta2 modified).

RESULTS

In the group that received irradiated MRH unmodified cells, 55% of rats died from tumor burden, and 36% developed tumor regression. In the group that received irradiated MRH cells modified with pCEP-4 vector alone, 50% died from tumors and 33% had spontaneous regression. In animals treated with pCEP-4/TGF-beta antisense modified cells, none developed tumors. Cell-mediated cytotoxicity assays demonstrated a twofold increase in lytic activity in the effector cells of the animals treated with antisense modified cells.

CONCLUSIONS

These results demonstrate the successful treatment of HCC tumors in rats by a HCC vaccine genetically altered with antisense TGF-beta2. Decreased production of TGF-beta in HCC vaccine enhances immunogenicity against wild-type HCC tumor cells.

Regulatory cells potentiate the efficacy of IL-4 gene transfer by up-regulating Th2-dependent expression of protective molecules in the infectious tolerance pathway in transplant recipients

We have previously shown that the tolerant state in allograft recipients can be maintained and perpetuated by an "infectious" T cell-dependent regulatory mechanism. Hence, 1) treatment of LEW rats with RIB-5/2, a CD4 nondepleting mAb, produces indefinite survival of LBNF1 cardiac allografts; 2) donor-specific tolerance can be then transferred by spleen cells into new cohorts of test allograft recipients; and 3) putative regulatory CD4+ Th2-like cells are instrumental in this tolerance model. We now report on studies aimed at exposing mechanisms underlying the infectious tolerance pathway, with emphasis on the interactions between intragraft adenovirus-IL-4 gene transfer and systemic infusion of regulatory cells from tolerant hosts. Unlike individual treatment regimens, adjunctive therapy with adenovirus-IL-4 and suboptimal doses of regulatory spleen cells was strongly synergistic and extended donor-type test cardiac allograft survival to about 2 mo. RT-PCR-based expression of intragraft mRNA coding for IL-2 and IFN-gamma remained depressed, whereas that of IL-4 and IL-10 reciprocally increased selectively in the combined treatment group, data supported by ELISA studies. In parallel, only adjunctive treatment triggered intragraft induction of molecules with anti-oxidant (HO-1) and anti-apoptotic (Bcl-xL/Bag-1) but not with pro-apoptotic (CPP-32) functions, both in the early and late posttransplant phases. Hence, systemic infusion of regulatory cells potentiates the effects of local adenovirus-IL-4 gene transfer in transplant recipients. Th2-driven up-regulation of protective molecule programs at the graft site, such as of anti-oxidant HO-1 and/or anti-apoptotic Bcl-xL and Bag-1, may contribute, at least in part, to the maintenance of the infectious tolerance pathway in transplant recipients.

Fas ligand gene transfer prolongs rat renal allograft survival and down-regulates anti-apoptotic Bag-1 in parallel with enhanced Th2-type cytokine expression

BACKGROUND

Fas ligand (FasL) induces apoptosis of cells bearing Fas receptor, and may play a role in the acquisition of immune privilege. We have previously shown that adenovirus (Ad)-mediated FasL gene transfer significantly prolongs survival in a strongly major histocompatibility complex-incompatible rat kidney allograft model. This study analyzes putative mechanisms of FasL-mediated effects, with particular emphasis on Th1 and Th2 immune activation and Bag-1 expression, a Bcl-2-binding anti-apoptotic protein.

METHODS

Kidney transplants were performed in Wistar-Furth to Lewis rat combination. Donor kidneys were perfused in situ with Ad-FasL or Ad-beta-Gal, and then transplanted. Kidney allografts were harvested at days 2, 7, and 56 and were evaluated by hematoxylin and eosin and immunohistochemical staining. The expression of FasL, Bag-1, and Th1/Th2 cytokine genes was assessed by Northern blots, Western blots, and competitive template reverse-transcriptase polymerase chain reaction, respectively.

RESULTS

Intragraft expression of FasL was enhanced, whereas that of anti-apoptotic Bag-1 gene was diminished throughout, in Ad-FasL-transduced well-functioning renal allografts, compared with Ad-beta-Gal-treated rejecting controls. In parallel, the expression of mRNA coding for IL-2 and IFN-gamma remained depressed, whereas that of IL-4 and IL-10 reciprocally and progressively increased in the Ad-FasL animal group.

CONCLUSIONS

Prolonged survival in Ad-FasL-transduced rat renal allograft model correlates with down-regulation of Bag-1, a novel anti-apoptotic gene, and preferential Th2-type cytokine elaboration profile at the graft site. Because Th1-like cells are sensitive to FasL-mediated cytotoxic effects, T-cell apoptosis may preferentially spare Th2-like cells, with resultant prolonged graft survival.

Upregulation of heme oxygenase-1 protects genetically fat Zucker rat livers from ischemia/reperfusion injury

We examined the effects of upregulation of heme oxygenase-1 (HO-1) in steatotic rat liver models of ex vivo cold ischemia/reperfusion (I/R) injury. In the model of ischemia/isolated perfusion, treatment of genetically obese Zucker rats with the HO-1 inducer cobalt protoporphyrin (CoPP) or with adenoviral HO-1 (Ad-HO-1) significantly improved portal venous blood flow, increased bile production, and decreased hepatocyte injury. Unlike in untreated rats or those pretreated with the HO-1 inhibitor zinc protoporphyrin (ZnPP), upregulation of HO-1 by Western blots correlated with amelioration of histologic features of I/R injury. Adjunctive infusion of ZnPP abrogated the beneficial effects of Ad-HO-1 gene transfer, documenting the direct involvement of HO-1 in protection against I/R injury. Following cold ischemia/isotransplantation, HO-1 overexpression extended animal survival from 40% in untreated controls to about 80% after CoPP or Ad-HO-1 therapy. This effect correlated with preserved hepatic architecture, improved liver function, and depressed infiltration by T cells and macrophages. Hence, CoPP- or gene therapy-induced HO-1 prevented I/R injury in steatotic rat livers. These findings provide the rationale for refined new treatments that should increase the supply of usable donor livers and ultimately improve the overall success of liver transplantation.

Irradiation-induced up-regulation of Fas in esophageal squamous cell carcinoma is not accompanied by Fas ligand-mediated apoptosis

BACKGROUND AND OBJECTIVES

Fas (APO-1) induces apoptosis after binding Fas ligand (FasL). Evidence suggests that tumors may use this interaction to evade the host immune response. Fas/FasL expression has not been reported in esophageal cancer. We hypothesized that Fas expression would render esophageal cancer cells susceptible to Fas ligation and that irradiation of the cells would increase Fas expression.

METHODS

Two human esophageal squamous cell carcinoma lines, KYSE 150, which has a wild-type (wt) p53 gene, and 410 (mutated p53), were irradiated. Reverse-transcriptase polymerase chain reaction was used to detect Fas and FasL expression. Fas protein was quantitated by enzyme-linked immunosorbent assay and its presence further confirmed by Western analysis. FasL was detected by Western analysis. Cells were treated with Fas monoclonal antibody (maximum 0.05 microg/ml)+/-cycloheximide, and viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cells were also transduced with FasL cDNA and then quantified.

RESULTS

Both lines expressed Fas and FasL, but only the KYSE 150 cell line displayed an increase in Fas following irradiation. No alteration in cell growth was detected for Fas antibody- or FasL-transduced groups versus controls.

CONCLUSIONS

We have demonstrated Fas and FasL expression in esophageal tumor lines. We have also shown that Fas levels are significantly increased in response to irradiation in a wt p53 line. However, cells were resistant to treatment with Fas antibody or following transduction with FasL, suggesting that these tumor cells may use Fas/FasL expression to evade the host immune response.

Effects of pravastatin on chronic rejection of rat cardiac allografts

BACKGROUND

Pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, inhibits coronary transplant vasculopathy in the clinical setting. To further delineate the immune modulatory effect of this agent, it was tested in a rat cardiac transplant model of chronic rejection.

METHODS

Rat heterotopic abdominal cardiac transplants were performed using a Lewis to Fischer 344 combination. Fischer 344 recipients received a brief course of cyclosporine to decrease the incidence of acute rejection. Experimental groups were treated with either high-dose (10 mg/kg) or low-dose (5 mg/kg) pravastatin for 120 days, while a control group did not receive pravastatin. The effect of pravastatin on chronic rejection of cardiac allografts was analyzed by histology, and the expression of laminin, fibronectin, macrophages, and T cells was assessed by immunohistochemistry.

RESULTS

Coronary transplant vasculopathy was inhibited in both groups of pravastatin-treated animals, as compared with controls. Immunohistochemistry revealed that control animals had degraded laminin and fibronectin which paralleled the degree of tissue necrosis. In contrast, pravastatin-treated animals had modest amounts of extracellular matrix proteins retained within intermyocytes and endothelium, a pattern seen in native cardiac tissue. The pravastatin-treated groups also had fewer graft-infiltrating macrophages, specifically within the arterial intima and perivascular areas.

CONCLUSIONS

Progressive chronic vascular rejection, a leading cause of allograft failure, can be inhibited by pravastatin in a well-defined rat cardiac transplant model. Pravastatin appears to inhibit the synthesis and subsequent degradation of extracellular matrix proteins and block the infiltration of macrophages to the graft, which emphasizes that this inflammatory cell plays a major role in the pathogenesis of transplant chronic rejection.

Fas ligand gene transfer to renal allografts in rats: effects on allograft survival

BACKGROUND

Fas ligand (FasL) induces apoptosis of cells bearing its receptor Fas, and has been shown to be important in T-cell development and regulation and in immune privilege. We hypothesized that FasL expression by renal allografts might provide protection from rejection.

METHODS

The murine FasL cDNA was cloned into a replication-defective adenovirus (AdV-FasL). Protein expression was confirmed by immunostaining of AdV-FasL-transduced HeLa cells. Allogeneic kidney transplants were performed between WF (RT1u) donors and Lewis (RT1) recipients. Donor kidneys were perfused in situ with saline alone (control), or 9 x 10(9) plaque-forming units of AdV-FasL. One native kidney was removed at the time of transplant and the other at 6 or 7 days. Uremic death was the endpoint, and deaths within 7 days of transplant were excluded. Transduced allografts were stained for FasL expression using a monoclonal antibody and tested for FasL mRNA production by reverse transcriptase-polymerase chain reaction and Northern blotting.

RESULTS

Immunostaining of AdV-FasL-transduced allografts demonstrated efficient gene transfer lasting approximately 2 weeks, and FasL mRNA production in the AdV-FasL-transduced allografts was confirmed by Northern blotting and reverse transcriptase-polymerase chain reaction. Mean survival of animals with AdV-FasL-transduced renal allografts was 27.8 days vs. 11.6 days in control animals (P < 0.05).

CONCLUSIONS

(1) Adenoviral vectors can successfully transduce rat kidneys with the FasL cDNA. (2) FasL gene transfer prolongs rat renal allograft survival.

Pravastatin increases survival and inhibits natural killer cell enhancement factor in liver transplanted rats

Pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has been shown to decrease the number of acute rejection episodes in cardiac and renal transplant patients. This study evaluates the effects of pravastatin on survival of rats following liver transplant and attempts to elucidate the mechanisms of these effects. Both survival and natural killer cell enhancing factor (NKEF) studies utilized Dark Agouti rats for donor livers transplanted into Brown Norway rats as recipients. All rats received daily low-dose cyclosporine (CsA) 2 mg/kg/day by gavage. The treated groups also received gavage doses of pravastatin, 20 mg/kg/day. Survival data were analyzed by the method of Kaplan-Meier and log-rank chi 2 tests for statistical significance. For NKEF evaluation, rats were sacrificed at varying time points; total RNA was extracted from the liver and hybridized with 32P-radiolabeled NKEF DNA probes in the Northern blot technique. Radiographs were quantitated using densitometry. Data were analyzed by two-way ANOVA. Actuarial survival was improved (P < < 0.05) in rats treated with pravastatin in addition to low-dose CsA (n = 41, CsA alone n = 74). Less fibrosis and chronic rejection was seen on histological section in the treated animal livers, P < 0.05, NKEF was seen maximally at Days 5-15 tapering off at Day 21. NKEF-a and NKEF-b levels were significantly decreased in the animals treated with CsA and pravastatin compared to CsA alone in the group of animals < 16 days postop (P < < 0.05). Pravastatin improves survival in rats following OLT and while the mechanism is still unknown, inhibition of natural killer cell enhancement factor may represent an alteration in the overall immune response.