转hCTLA4-IgG基因小鼠移植皮肤在糖尿病大鼠创面存活的延 长

CTLA4-IgG是呈分泌性表达的CTLA4胞外区与人IgG恒定区的融合分子 ,可有效阻断T细胞B7-CD28共刺激信号通路,从而抑制T细胞活化、延长移 植物存活.糖尿病溃疡创面难愈合是其高致病力和高致残率的主要原因,而 及时有效的封闭创面是创面愈合的关键.异种（异体）皮肤是应用广泛的创 面覆盖物,但免疫排斥反应是移植皮肤存活的主要障碍.通过建立糖尿病大 鼠溃疡创面模型,研究表达人CTLA4-IgG蛋白的转基因小鼠皮肤在糖尿病大 鼠溃疡创面的存活及对创面愈合的影响.结果发现：糖尿病大鼠溃疡创面的 自然愈合时间显著长于正常大鼠(41.7±7.4 d vs 18.5±6.9 d, P <0.01),说明糖尿病大鼠及其溃疡模型已建立;在糖尿病大鼠创面,转 基因皮肤存活时间为22.2±5.8 d,显著长于野生型皮肤(8.2±1.8 d, P<0.01);在转基因皮肤移植后27d,糖尿病大鼠创面已完全愈合, 显著快于其自然愈合过程;在供、受体混合淋巴细胞反应（MLR）中,转基 因皮肤移植受体的淋巴细胞对供体抗原的应答能力与野生型皮肤移植受体无 显著差异.上述结果表明,移植皮肤表达人CTLA4-IgG蛋白可显著延长其在 糖尿病大鼠创面的存活时间,进而促进创面愈合,并对受体免疫系统无显著 的全身性影响     

Prolonged Graft Survival in Older Recipient Mice Is Determined by Impaired Effector T-Cell but Intact Regulatory T-Cell Responses

Elderly organ transplant recipients represent a fast growing segment of patients on the waiting list. We examined age-dependent CD4⁺ T-cell functions in a wild-type (WT) and a transgenic mouse transplant model and analyzed the suppressive function of old regulatory T-cells. We found that splenocytes of naïve old B6 mice contained significantly higher frequencies of T-cells with an effector/memory phenotype (CD4⁺CD44^highCD62L^low). However, in-vitro proliferation (MLR) and IFNγ-production (ELISPOT) were markedly reduced with increasing age. Likewise, skin graft rejection was significantly delayed in older recipients and fewer graft infiltrating CD4⁺T-cells were observed. Old CD4⁺ T-cells demonstrated a significant impaired responsiveness as indicated by diminished proliferation and activation. In contrast, old alloantigen-specific CD4⁺CD25⁺FoxP3⁺ T-cells demonstrated a dose-dependent well-preserved suppressor function. Next, we examined characteristics of 18-month old alloreactive T-cells in a transgenic adoptive transfer model. Adoptively transferred old T-cells proliferated significantly less in response to antigen. Skin graft rejection was significantly delayed in older recipients, and graft infiltrating cells were reduced. In summary, advanced recipient age was associated with delayed acute rejection and impaired CD4⁺ T-cell function and proliferation while CD4⁺CD25⁺FoxP3⁺ T-cells (Tregs) showed a well-preserved function.     

Prolonged Survival of Campylobacter Species in Bovine Manure Compost

The persistence of naturally occurring campylobacteria in aerobic compost constructed of manure from beef cattle that were administered chlortetracycline and sulfamethazine (AS700) or from cattle not administered antibiotics (control) was examined. Although there were no differences in population sizes of heterotrophic bacteria, the temperature of AS700 compost was more variable and did not become as high as that of control compost. There were significant differences in water content, total carbon (C), total nitrogen (N), and electrical conductivity but not in the C/N ratio or pH between the two compost treatments. Campylobacteria were readily isolated from pen manure, for up to day 15 from control compost, and throughout the active phase of AS700 compost. Campylobacter DNA (including Campylobacter coli, Campylobacter fetus, Campylobacter hyointestinalis, and Campylobacter jejuni) was detected over the ca. 10-month composting period, and no reductions in quantities of C. jejuni DNA were observed over the duration of the active phase. The utilization of centrifugation in combination with ethidium monoazide (EMA) significantly reduced (>90%) the amplification of C. jejuni DNA that did not originate from cells with intact cell membranes. No differences were observed in the frequency of Campylobacter DNA detection between EMA- and non-EMA-treated samples, suggesting that Campylobacter DNA amplified from compost was extracted from cells with intact cell membranes (i.e., from viable cells). The findings of this study indicate that campylobacteria excreted in cattle feces persist for long periods in compost and call into question the common belief that these bacteria do not persist in manure.Campylobacter jejuni and, to a lesser extent, Campylobacter coli incite serious acute and chronic afflictions. Enteritis caused by C. jejuni (i.e., campylobacteriosis) is the most common cause of bacterial enteritis in Canada (http://dsol-smed.phac-aspc.gc.ca/dsol-smed/ndis/index-eng.php). Although the epidemiology of campylobacteriosis is poorly understood, sporadic outbreaks of campylobacteriosis involving contaminated water have occurred when water treatment has failed. The most serious outbreak in Canada occurred in Walkerton Ontario in 2000; more than 2,300 people became infected with waterborne Escherichia coli O157:H7 and/or C. jejuni originating from cattle feces (3). Alberta, Canada, possesses a very large beef cattle population (≈6 million animals) primarily concentrated in the southern region of the province, and ≈2 million of these animals are in finishing feedlots (1). Large quantities of manure are produced by feedlot cattle. For example, in the Chinook Health Region of Southwestern Alberta in which Lethbridge is situated, there are ≈700,000 cattle in feedlots at any given time, producing ≈12 million kg of manure (fresh weight) per day. Several Campylobacter species, including C. jejuni and C. coli, are frequently shed in beef cattle feces in large numbers (15, 16). Although the impact of cattle-borne campylobacters on human health has not been definitely determined, the southern region of Alberta possesses one of the highest rates of campylobacteriosis in Canada among its human inhabitants, concomitant with the very high density of cattle in this region.Large-scale windrow composting of bovine manure from intensive cattle operations is practiced by some Alberta feedlots. Composting is an aerobic process in which organic matter in manure is stabilized into a humus-like product (30). The process results in water loss and mass reduction, nutrient transformation (22), alteration of physical structure (23), elimination of weed seeds (21), and the inactivation of coliform bacteria (25), protozoan cysts and oocysts (34), and viruses (39). Limited research has investigated the impact of manure management systems, such as aerobic composting, on deactivation of campylobacters. Furthermore, the impact of antimicrobial agents excreted into the manure on the efficacy of the composting process on Campylobacter deactivation has not been investigated. Most studies conducted to date have indicated that campylobacters do not persist well in solid manure once excreted (7, 11, 12, 26, 32, 39). Although it is difficult to isolate or enumerate Campylobacter species within microbiologically complex substrates, molecular detection and/or quantification methods have not been extensively applied to study the persistence of campylobacteria. Furthermore, the persistence of naturally shed campylobacteria has largely been overlooked. Thus, the overall objective of the current study was to measure the ability of campylobacteria naturally shed in bovine feces to persist in manure compost using a combination of culture- and culture-independent methods. Specific objectives were (i) to develop and utilize a centrifugation method to facilitate isolation and detection of DNA from Campylobacter species in bovine manure compost, (ii) to apply qualitative and quantitative PCR methods to evaluate persistence of campylobacteria in compost, (iii) to validate the molecular methods used to amplify DNA from viable cells, and (iv) to contrast the persistence of Campylobacter species in composted manure obtained from beef cattle maintained on a diet supplemented with chlortetracycline and sulfamethazine (AS700) with composted manure from animals not administered antimicrobial agents.     

Prolonged Oliguria with Survival in Acute Bilateral Cortical Necrosis

Survival is uncommon in cases of acute bilateral cortical necrosis. Three cases admitted to the renal unit at Newcastle have regained useful renal function after oliguric phases of 38, 46, and 120 days.Prolonged periods of intermittent dialysis are justified in patients in whom a firm diagnosis of acute cortical necrosis is made.     

Survival of Arthrobacter crystallopoietes During Prolonged Periods of Extreme Desiccation

Cells of Arthrobacter crystallopoietes mixed in sand and air-dried have survived for up to 6 months after an initial period in which approximately half the cells lost their viability. Comparative survival curves have been obtained from inoculated sands maintained under CaSO(4) or P(2)O(5). Selections for more desiccation-resistant progeny capable of surviving the initial period were unsuccessful. Both the coccoid and rod-shaped forms are equally resistant to several months of desiccation. Desiccated spherical cells converted 0.0005% of their cell carbon to carbon dioxide per hr, which corresponds to a half-life for self-consumption of approximately 12 years.     

Impact of Early Reoperation following Living-Donor Liver Transplantation on Graft Survival

Background

The reoperation rate remains high after liver transplantation and the impact of reoperation on graft and recipient outcome is unclear. The aim of our study is to evaluate the impact of early reoperation following living-donor liver transplantation (LDLT) on graft and recipient survival.

Methods

Recipients that underwent LDLT (n = 111) at the University of Tokyo Hospital between January 2007 and December 2012 were divided into two groups, a reoperation group (n = 27) and a non-reoperation group (n = 84), and case-control study was conducted.

Results

Early reoperation was performed in 27 recipients (24.3%). Mean time [standard deviation] from LDLT to reoperation was 10 [9.4] days. Female sex, Child-Pugh class C, Non-HCV etiology, fulminant hepatitis, and the amount of intraoperative fresh frozen plasma administered were identified as possibly predictive variables, among which females and the amount of FFP were identified as independent risk factors for early reoperation by multivariable analysis. The 3-, and 6- month graft survival rates were 88.9% (95%confidential intervals [CI], 70.7–96.4), and 85.2% (95%CI, 66.5–94.3), respectively, in the reoperation group (n = 27), and 95.2% (95%CI, 88.0–98.2), and 92.9% (95%CI, 85.0–96.8), respectively, in the non-reoperation group (n = 84) (the log-rank test, p = 0.31). The 12- and 36- month overall survival rates were 96.3% (95%CI, 77.9–99.5), and 88.3% (95%CI, 69.3–96.2), respectively, in the reoperation group, and 89.3% (95%CI, 80.7–94.3) and 88.0% (95%CI, 79.2–93.4), respectively, in the non-reoperation group (the log-rank test, p = 0.59).

Conclusions

Observed graft survival for the recipients who underwent reoperation was lower compared to those who did not undergo reoperation, though the result was not significantly different. Recipient overall survival with reoperation was comparable to that without reoperation. The present findings enhance the importance of vigilant surveillance for postoperative complication and surgical rescue at an early postoperative stage in the LDLT setting.     

Bacteria Induce Prolonged PMN Survival via a Phosphatidylcholine-Specific Phospholipase C- and Protein Kinase C-Dependent Mechanism

Polymorphonuclear leukocytes (PMNs) are essential for the human innate immune defense, limiting expansion of invading microorganisms. PMN turnover is controlled by apoptosis, but the regulating signaling pathways remain elusive, largely due to inherent differences between mice and humans that undermine use of mouse models for understanding human PMN biology. Here, we aim to elucidate signal transduction mediating survival of human peripheral blood PMNs in response to bacteria, such as Yersinia pseudotuberculosis, an enteropathogen that causes the gastro-intestinal disease yersiniosis, as well as Escherichia coli and Staphylococcus aureus. Determinations of cell death reveal that uninfected control cells undergo apoptosis, while PMNs infected with either Gram-positive or -negative bacteria show profoundly increased survival. Infected cells exhibit decreased caspase 3 and 8 activities, increased mitochondrial integrity and are resistant to apoptosis induced by a death receptor ligand. This bacteria-induced response is accompanied by pro-inflammatory cytokine production including interleukin-8 and tumor necrosis factor-α competent to attract additional PMNs. Using agonists and pharmacological inhibitors, we show participation of Toll-like receptor 2 and 4, and interestingly, that protein kinase C (PKC) and phosphatidylcholine-specific phospholipase C (PC-PLC), but not tyrosine kinases or phosphatidylinositol-specific phospholipase C (PI-PLC) are key players in this dual PMN response. Our findings indicate the importance of prolonged PMN survival in response to bacteria, where general signaling pathways ensure complete exploitation of PMN anti-microbial capacity.     

The Impact of Prolonged Storage of Red Blood Cells on Cancer Survival

Background

The duration of storage of transfused red blood cells (RBC) has been associated with poor clinical outcomes in some studies. We sought to establish whether prolonged storage of transfused RBC in cancer patients influences overall survival (OS) or cancer recurrence.

Methods and Findings

Patients diagnosed with cancer at The Ottawa Regional Cancer Centre between January 01, 2000 and December 31, 2005 were included (n = 27,591) where 1,929 (7.0%) received RBC transfusions within one year from diagnosis. Transfused RBC units were categorized as “new” if stored for less than 14 days, “intermediate” if stored between 14 and 28 days and “old” if stored for more than 28 days. Baseline characteristics between the comparative groups were compared by ANOVA test. Categorical variables and continuous variables were compared using Chi-squared and Wilcoxan rank-sum tests respectively. Overall survival was not associated with duration of storage of transfused RBC with a median survival of 1.2, 1.7, 1.1 years for only new, intermediate and old RBC units respectively (p = 0.36). Cancer recurrence was significantly higher in patients who received a RBC transfusion than those who did not (56.3% vs 33.0% respectively; p<0.0001) but was not affected by the duration of storage of transfused RBC (p = 0.06). In multivariate analysis, lung cancer, advanced stage, chemotherapy, radiation, cancer-related surgery and cancer recurrence were associated with inferior OS (p<0.05), while age, advanced stage, lung cancer, and more than 6 units of blood transfused were associated with cancer recurrence (p<0.05). The duration of storage of RBC before transfusion was not associated with OS or cancer recurrence in multivariate analysis.

Conclusion

In patients diagnosed with cancer, the duration of storage of transfused RBC had no impact on OS or cancer recurrence. This suggests that our current RBC storage policy of providing RBC of variable duration of storage for patients with malignancy is safe.     

Prolonged Survival of CAM-Mode Mesembryanthemum crystallinum in Darkness and its Possible Dependence on Malate

A remarkable difference was found in the survival of leavesof Mesembryanthemum crystallinum with plants grown in the C₃versus the CAM mode. With excised leaves (petiole in solution)of C₃-mode plants subjected to 6 days of darkness, there wasa large reduction in the chlorophyll content of the leaf andleaf turgor had decreased. By day 9, the chlorophyll had disappeared,except at the major veins, and the leaf tip had dried and turnedbrown. In contrast, the leaf tissue in the CAM mode showed onlya partial loss of chlorophyll during the same period, and evenafter 17 days of darkness, the tissue at the base was stillalive. Similarly, intact plants grown in the C₃ mode deterioratedmuch faster during 20 days of darkness than did plants grownin the CAM mode. Chlorophyll content, chlorophyll a/b ratio,phosphoenolpyruvate carboxylase, NADP-malic enzyme, malate andstarch content were measured. In both C₃- and CAM-mode plants,the starch content decreased rapidly during the dark periodand was nearly depleted after two days. In the CAM-mode tissue,there was a relatively high level of malate during prolongeddarkness (up to 17 days), with a transitory rise early in thedark period. In contrast, the malate content was low and rapidlydepleted in the C₃-mode leaves kept in darkness. These findingssuggest that malate may be an important source of carbon forsustaining leaves of CAM-mode M. crystallinum during prolongeddarkness. (Received May 20, 1987; Accepted October 23, 1987)     

小半夏加茯苓汤对小鼠移植心存活时间的延长效果研究

目的:探讨小半夏加茯苓汤对小鼠心脏移植模型中移植心存活时间的延长效果及作用机制。方法:将接受过腹腔心脏移植手术的小鼠分为实验组和对照组,自移植手术当日起至术后7天,每日经口给药,通过腹部触诊判断移植心脏跳动情况,移植术后30日,取部分小鼠移植心脏进行病理检查,取脾细胞进行淋巴细胞培养,并检测培养液中白细胞介素(IL)-2、IL-4、IL-10和干扰素(IFN)-γ的浓度。取移植心脏存活时间超过30天的小鼠脾脏,通过流式细胞术检测调节性T细胞(Regulatory Tcells,Tregs)的含量。结果:与对照组相比,实验组的移植心存活时间明显延长(P0.01),心脏病理切片结果提示实验组的心脏血管病变受到了抑制,脾细胞培养液中IL-2和IFN-γ浓度明显降低,而IL-4和IL-10的浓度升高,脾细胞CD4阳性细胞中CD25和Foxp3均阳性的细胞含量明显高于对照组中同类细胞含量。结论:小半夏加茯苓汤可以显著延长小鼠移植心脏的存活时间,可能与其诱导调节T细胞的产生、改变受体小鼠体内Th-1和Th-2细胞因子的平衡及抑制IL-2、IFN-γ减轻心脏损伤有关。     

Prolonged Survival of Tetrahymena at 0.5 C in Citrated, Lecithinized, Defined Media

SYNOPSIS. A fully defined medium aside, also one with acid-hydrolyzed casein, both pH 6.2–6.4 permitted survival of Tetrahymena pyriformis (syngen 1, mating type II) for no more than a week at 0.5 C, despite fortification with crude soy lecithin. Lecithin had permitted prolonged survival in crude media (pH 7.2), probably due largely to its phytosterols and antioxidants. Metal imbalances appeared responsible for the poor survival in defined media because additional citrate, histidine or Fe permitted monthlong survival. Al or Ni in the presence of increased citrate were also favorable. The casein-hydrolysate medium and a fully defined medium, both fortified with lecithin, and with additional citrate or Fe, permitted survival at 0.5 C for at least 2 months. Krebs-cycle intermediates, uridine, thymidine, adenosine, and guanosine acted as growth substrates in nearly carbohydrate-free media, which suggests trial of their survival-promoting properties for cold-stored cultures. Parallels are noted for survival in the cold between Tetrahymena and erythrocytes and sperm.     

Survival ofDrosophila melanogaster Progeny after Prolonged Suppression of Pairing and Recombination in Autosome 3

Two laboratory strains of Drosophila melanogaster carrying autosome 3 with a meiotic mutation c(3)G, that is maintained since 1985 in various balancer chromosomes, were used to study progeny survival. The conditions of maintenance of these strains and the effect of c(3)G mutation completely suppress pairing and crossing over in autosome 3. In addition, selection pressure was reduced because of permanent heterozygosity, mediating mutation accumulation in the studied chromosome. In both strains, all homozygotes for autosome 3 (c(3)G/c(3)G) perished. The hybrid homozygotes carrying chromosomes with c(3)G mutation from different strains survived in 0.4 of the progeny. Higher viability was observed after normal pairing and meiotic recombination of the studied chromosome with the chromosome from the wild-type line. The possible nature of mutations accumulated after prolonged suppression of chromosome pairing and recombination is discussed.     

Survival of Skin Graft between Transgenic Cloned Dogs and Non-Transgenic Cloned Dogs

Whereas it has been assumed that genetically modified tissues or cells derived from somatic cell nuclear transfer (SCNT) should be accepted by a host of the same species, their immune compatibility has not been extensively explored. To identify acceptance of SCNT-derived cells or tissues, skin grafts were performed between cloned dogs that were identical except for their mitochondrial DNA (mtDNA) haplotypes and foreign gene. We showed here that differences in mtDNA haplotypes and genetic modification did not elicit immune responses in these dogs: 1) skin tissues from genetically-modified cloned dogs were successfully transplanted into genetically-modified cloned dogs with different mtDNA haplotype under three successive grafts over 63 days; and 2) non-transgenic cloned tissues were accepted into transgenic cloned syngeneic recipients with different mtDNA haplotypes and vice versa under two successive grafts over 63 days. In addition, expression of the inserted gene was maintained, being functional without eliciting graft rejection. In conclusion, these results show that transplanting genetically-modified tissues into normal, syngeneic or genetically-modified recipient dogs with different mtDNA haplotypes do not elicit skin graft rejection or affect expression of the inserted gene. Therefore, therapeutically valuable tissue derived from SCNT with genetic modification might be used safely in clinical applications for patients with diseased tissues.