Preferential priming of alloreactive T cells with indirect reactivity

The relative contributions of the direct and indirect pathways in alloimmune responses have not been fully elucidated. We report a novel murine TCR transgenic system that can simultaneously track the CD4-direct (CD4-d), CD4-indirect (CD4-i) and CD8-direct (CD8-d) pathways after transplantation. Using this system, we have observed a profoundly greater proliferation of CD4-i T cells relative to CD4-d and CD8-d T cells after transplantation. Furthermore, a much larger proportion of CD4-i T cells attain an effector phenotype. We also analyzed endogenous, wild-type T cells using enzyme-linked immunospot analysis. In naïve mice, T cells with indirect reactivity were undetectable, but T cells with direct reactivity were abundant. However, 10 days after skin or heterotopic heart transplantation, CD4-i T cells comprised approximately 10% of the CD4+ response. Consistent with increased priming of the CD4-i pathway, we observed that the CD4-i T cells were further enriched in the effector cells migrating to the allograft and in memory-like T cells persisting after rejection. Thus, priming of the CD4-i pathway is favored after transplantation, allowing a rare population to rapidly become a major component of the CD4+ T-cell response in acute allograft rejection. The generalizability of this observation to other models remains to be determined.

Apoptosis inducing and differentiation enhancement effect of oridonin on the all-trans-retinoic acid-sensitive and -resistant acute promyelocytic leukemia cells

We investigated the effects of oridonin (Ori), a diterpenoid isolated from Rabdosia rubescens, on apoptosis and differentiation of all-trans-retinoic acid (ATRA)-sensitive (NB4) and ATRA-resistant (NB4-R1) cells. The results showed that reactive oxygen species initiates Ori-induced apoptosis. In addition, we found that neither Ori nor ATRA (10 nM) alone induced marked cell differentiation, while co-treatment of these two compounds can induce differentiation of NB4 and NB4-R1 cells which was accompanied by increased RARalpha, C/EBPepsilon or C/EBPbeta. This is the first report to show that RARalpha could be accumulated by Ori which may be useful as a probe to investigate the mechanism of RARalpha catabolism. These results suggest that Ori is a potential candidate for acute promyelocytic leukemia cancer therapy.

Interleukin-6 increases prostate cancer cells resistance to bicalutamide via TIF2

The standard treatment for advanced, androgen-responsive prostate cancer is androgen deprivation therapy with or without a nonsteroidal antiandrogen, such as bicalutamide. Although maximal androgen blockade exhibits favorable responses in the majority of patients, prostate cancer eventually progresses to an androgen-refractory stage. The mechanism underlying bicalutamide resistance in the course of prostate cancer progression is incompletely understood. However, interleukin-6 (IL-6) plays a critical role in the development and progression of CRPC. Herein, we explored an association between IL-6 and bicalutamide resistance. To study this, series of lower and higher passages of LNCaP cell sublines generated by long-term exposure to IL-6 were used. The cells from higher passages of LNCaP treated with IL-6 developed resistance to bicalutamide treatment compared with parental LNCaP cells. The levels of transcriptional intermediary factor 2 (TIF2) in IL-6-treated LNCaP cells were found to be significantly higher than parental LNCaP cells. Down-regulation of TIF2 expression via short hairpin RNA in IL-6-treated LNCaP cells sensitized these cells to bicalutamide treatment, whereas overexpression of TIF2 in the parental LNCaP cells increased resistance to bicalutamide. Furthermore, overexpression of IL-6 attenuated bicalutamide-mediated blockage of androgen-induced androgen receptor nuclear translocation and recruitment. These results show that overexpression of IL-6 increases the resistance of prostate cancer cells to bicalutamide via TIF2. Overexpression of IL-6 not only plays an important role in prostate cancer progression but also contributes to bicalutamide resistance. Our studies suggest that bicalutamide-IL-6-targeted adjunctive therapy may lead to a more effective intervention than bicalutamide alone.

Change of cardiac function in experimental autoimmune myocarditis is correlated with the expression of annexin VI

OBJECTIVE

The objective of this study was to investigate annexin VI expression in polypeptides-induced experimental autoimmune myocarditis (EAM) in mice, and explore the relationship between the annexin VI and cardiac function at different periods of myocarditis.

METHODS AND RESULTS

BALB/C mice were randomly divided into two main groups: control and polypeptides-induced EAM group; the PA and the PC groups represent the acute and the chronic phase of myocarditis in polypeptides-induced EAM group separately. Cardiac function was evaluated by haemodynamic measurement. Myocardial histopathological observation was performed to identify the degree of inflammation in EAM. Expression level and distribution of annexin VI were assessed by Western blotting and immunohistochemistry. We found that the polypeptides induced myocarditis and moderately severe cardiomyopathic changes. Only the PC group had significantly reduced haemodynamics. Expression levels of annexin VI decreased in the PA group and increased in the PC group.

CONCLUSIONS

Annexin VI is down-regulated in the acute phase of EAM, and overexpressed in the chronic phase of EAM. Annexin-VI may be responsible for the compensation and aggravation of cardiac function in different phases of EAM.

The effects of NK4 on viral myocarditis mice

NK4 may be a promising agent to inhibit tumor invasion and metastasis. To observe the effects of NK4 on the cardiovascular system with pathological injury and to discuss the mechanism, we established an experimental model of viral myocarditis (VCM) by coxsackievirus B3 infection in Balb/c mice on Day 0 and administered NK4 twice daily to the VCM and control mice from Day 20 to Day 45. We then evaluated the cardiac function by means of ultrasonic inspection. Hepatocyte growth factor, TNF (tumor necrosis factor)-alpha, and angiotensin II levels in the myocardial tissue were measured with enzyme-linked immunosorbent assay. Myocardium histopathology was examined with hematoxylin and eosin stain. Collagen deposition of the myocardium was detected through Masson staining. Microvessel staining with the RECA antibody and apoptosis detection with terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling were performed in the myocardium. The changes in MMP3 (matrix metalloproteinase 3), MMP9, TIMP1 (tissue inhibitor of metalloproteinase 1), and TGF (transforming growth factor)-beta1 expression in the myocardium were measured by reverse-transcriptase polymerase chain reaction. We found that NK4 intervention increased TGF-beta and angiotensin II expression, suppressed MMPs, improved the activities of TIMPs, and then promoted collagen deposition in the myocardium. NK4 intervention also decreased the microvessels' density and increased the apoptotic cell count in the myocardia of VCM mice. However, we did not observe the obvious changes in the myocardia of control mice after NK4 intervention. These data suggest that NK4 made negative impacts on the restoration of cardiac function and the recovery from VCM in the experimental mice.

Cellular repressor of E1A-stimulated genes attenuates cardiac hypertrophy and fibrosis

Cellular repressor of E1A-stimulated genes (CREG) is a secreted glycoprotein of 220 amino acids. It has been proposed that CREG acts as a ligand that enhances differentiation and/or reduces cell proliferation. CREG has been shown previously to attenuate cardiac hypertrophy in vitro. However, such a role has not been determined in vivo. In the present study, we tested the hypothesis that overexpression of CREG in the murine heart would protect against cardiac hypertrophy and fibrosis in vivo. The effects of constitutive human CREG expression on cardiac hypertrophy were investigated using both in vitro and in vivo models. Cardiac hypertrophy was produced by aortic banding and infusion of angiotensin II in CREG transgenic mice and control animals. The extent of cardiac hypertrophy was quantitated by two-dimensional and M-mode echocardiography as well as by molecular and pathological analyses of heart samples. Constitutive over-expression of human CREG in the murine heart attenuated the hypertrophic response, markedly reduced inflammation. Cardiac function was also preserved in hearts with increased CREG levels in response to hypertrophic stimuli. These beneficial effects were associated with attenuation of the mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase 1 (MEK-ERK1)/2-dependent signalling cascade. In addition, CREG expression blocked fibrosis and collagen synthesis through blocking MEK-ERK1/2-dependent Smad 2/3 activation in vitro and in vivo. Therefore, the expression of CREG improves cardiac functions and inhibits cardiac hypertrophy, inflammation and fibrosis through blocking MEK-ERK1/2-dependent signalling.

Promoter polymorphism of interleukin-18 in angiographically proven coronary artery disease

Interleukin 18 (IL-18) is a pro-atherogenic cytokine associated with the occurrence of various cardiac complications. The IL-18 gene has a functional -137 G/C polymorphism (rs187238) in the promoter region. Using the ligase detection reaction-polymerase chain reaction, we genotyped a cohort of patients in Chinese Han population in Xiangfan region. Case patients of coronary artery disease and control patients were identified by coronary angiography. The plasma IL-18 concentrations were measured by ELISA. A significant increase of G allele or GG-genotype was observed in 241 case patients compared to 145 control individuals (frequency of G allele = 0.90 vs 0.83, p=0.004; frequency of GG-genotype = 0.81 vs 0.68, p = 0.005). In case patients, G allele carriers in multi-vessel disease patients had a higher occurrence rate when compared to single-vessel disease patients, but no significant difference was detected (frequency of G allele = 0.92 vs 0.88, p=0.107; frequency of GG-genotype = 0.84 vs 0.75, p = 0.089). IL-18 protein concentration of the -137GG genotype was much higher than concentration of the CG and CC genotype (case patients: 229.1+/-131.5 vs 122.7+/-73.6 pg/ml, P < 0.001; control patients: 65.9+/-31.6 vs 42.4+/-19.5 pg/ml, P < 0.001). To conclude, IL-18 promoter -137G/C polymorphism influences IL-18 levels and the occurrence of coronary artery disease, suggesting that IL-18 is causally involved in the development of atherosclerosis.

The 5-HT2 antagonist ketanserin is an open channel blocker of human cardiac ether-à-go-go-related gene (hERG) potassium channels

BACKGROUND AND PURPOSE

Ketanserin, a selective 5-HT receptor antagonist, prolongs the QT interval of ECG in patients. The purpose of the present study was to determine whether ketanserin would block human cardiac ether-à-go-go-related gene (hERG) potassium channels.

EXPERIMENTAL APPROACH

Whole-cell patch voltage-clamp technique was used to record membrane currents in HEK 293 cells expressing wild type or mutant hERG channel genes.

KEY RESULTS

Ketanserin blocked hERG current (I(hERG)) in a concentration-dependent manner (IC50=0.11 microM). The drug showed an open channel blocking property, the block increasing significantly at depolarizing voltages between +10 to +60 mV. Voltage-dependence for inactivation of hERG channels was negatively shifted by 0.3 microM ketanserin. A 2.8 fold attenuation of inhibition by elevation of external K+ concentration (from 5.0 to 20 mM) was observed, whereas the inactivation-deficient mutants S620T and S631A had the IC50s of 0.84 +/- 0.2 and 1.7 +/-0.4 microM (7.6 and 15.4 fold attenuation of block). In addition, the hERG mutants in pore helix and S6 also significantly reduced the channel block (2-59 fold) by ketanserin.

CONCLUSIONS AND IMPLICATIONS

These results suggest that ketanserin binds to and blocks the open hERG channels in the pore helix and the S6 domain; channel inactivation is also involved in the blockade of hERG channels. Blockade of hERG channels most likely contributes to the prolongation of QT intervals in ECG observed clinically at therapeutic concentrations of ketanserin.

Long-term cognitive functions in neonatal short bowel syndrome patients

OBJECTIVE

The aim of the study was to evaluate the long-term effects of neonatal short bowel syndrome on cognitive functions during development.

SUBJECTS AND METHODS

Nine patients diagnosed with short bowel syndrome during the neonatal period were enrolled in this study. Their medical records were reviewed; anthropometric measurements and blood tests were assayed; IQ tests (the Chinese versions of WAIS-R, WPPSI-R and WISC-R) were performed depending on their age, and a BSID assessment was carried out in those patients less than 4 years old.

RESULTS

Eight of 9 patients were followed up except for one patient who died in a car accident at the age of three. All patients had been weaned off parenteral nutrition for more than 2 years. The average residual small bowel length was 58.1 cm (range 35-70 cm), and the mean parenteral nutrition (PN) duration was 73.1 days (43-147 days). The mean duration of the period without PN was 7.4 years (range 2.1-17.1 years). Weight, height and BMI for age were normal in 7 children except for 1 child, who was overweight. Hemoglobin and albumin concentrations were normal in all 8 patients. Evaluation of cognitive development showed normal results for all 8 patients while a verbal/performance discrepancy was found in 2.

CONCLUSION

Patients with neonatal SBS who were weaned off PN for more than 2 years were found to have normal growth and cognitive development during this long-term follow-up. There was no evidence for a strong correlation between SBS and nutritional/cognition disorder. Longer term and controlled studies with a larger sample size are warranted.

Mathematical analysis of an integral equation arising from population dynamics

In this paper, we establish the existence of travelling wave solution to an intrinsically non-linear differential-integral equation formed as a result of mathematical modelling of the evolution of an asexual population in a changing environment. This equation is first converted to a non-linear integral equation. The discretization and manipulation of the corresponding eigenvalue problem allows us to use the theory of positive matrices to get some very useful estimates and then to confirm the existence of solution. We also exhibit numerical simulation results and explain the biological meaning of the results.

β-CTX and ICTP Act as Indicators of Skeletal Metastasis Status in Male Patients with Non-Small Cell Lung Cancer

Bone metastasis is common in lung cancer patients and associated with reduced quality of life and reduced overall and median survival, so the early detection of bone metastasis and monitoring of its status is very important for clinicians. Serum bone-specific alkaline phosphatase (BAP), osteocalcin (OC), β isomer of C-terminal telopeptide of type I collagen (β-CTX) and cross-linked C-terminal telopeptide of type I collagen (ICTP) were compared with regard to their usefulness as indicators of bone metastasis in lung cancer. The serum concentrations of the 4 markers were measured by commercially available tests in 96 male patients with non-small cell lung cancer and 30 male patients with other pulmonary diseases. The levels of both β-CTX and ICTP were significantly higher in 61 lung cancer patients with bone metastases than in 35 lung cancer patients without bone metastases (both p<0.001), and significantly correlated with the extent of bone disease. Although ICTP had a better sensitivity and accuracy than β-CTX (75.4% vs 65.6% and 72.9% vs 68.8%, respectively), they had a similar area under the receiver operating characteristic curve (0.85 vs 0.83). These results support the use of β-CTX and ICTP as an adjunct tool for the diagnosis and screening of bone metastasis in lung cancer.

CD4+CD25+ regulatory T cells in transplantation: progress, challenges and prospects

The involvement of CD4(+)CD25(+) regulatory T cells (Treg) in general immune homeostasis and protection from autoimmune syndromes is now well established. Similarly, there has been increasing evidence for Treg involvement in allograft rejection and current immunotherapies. However, despite significant advances in understanding the development, function, and therapeutic efficacy of Treg in certain well-defined rodent models, the relevance of Treg to clinical transplantation remains unclear. In this review, we summarize our current understanding of the role of Treg in immunity and organ transplantation in experimental and clinical settings. In addition, we review advances in using Treg as a form of immune therapy. The goal is to highlight the complexities and opportunities in the field and to provide evidence to support the use of antigen-specific Tregs in the context of transplantation to facilitate a robust and selective state of immune tolerance.

Microarray analysis reveals the role of matrix metalloproteinases in mouse experimental autoimmune myocarditis induced by cardiac myosin peptides

Autoimmune myocarditis develops after the presentation of heart-specific antigens to autoaggressive CD4(+) T cells and after inflammation has infiltrated the tissues. To shed light on global changes in the gene expression of autoimmune myocarditis and to gain further insight into the molecular mechanisms underlying the genesis of myocarditis, we conducted a comprehensive microarray analysis of mRNA using an experimental mouse autoimmune myocarditis model via immunization with alpha-myosin heavy chain-derived peptides. Of over 39,000 transcripts on a high density oligonucleotide microarray, 466 were under-expressed and 241 over-expressed by >or= 1.5-fold compared with the controls in BALB/C mouse with autoimmune myocarditis. In this paper, we list the top 50 up-regulated genes related to the immune response. These altered genes encode for leukocyte-specific markers and receptors, the histocompatibility complex, cytokines/receptors, chemokines/receptors, adhesion molecules, components of the complement cascade, and signal transduction-related molecules. Interestingly, matrix metalloproteinases (MMPs) such as MMP-3 and MMP-9 were up-regulated, as further revealed by the reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry assays. This indicates that MMPs may act as major regulators of the cytokine profile. Together, these findings provide new insight into the molecular events associated with the mechanism of the autoimmune genesis of myocarditis.

Identification of B cell epitopes at the C-terminus of latency-associated nuclear protein of the kaposi's sarcoma-associated herpesvirus

The latency-associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV) plays a key role in the induction of cell transformation, maintenance of viral episome, and modulation of immune response in human. To identify the presence of B cell epitopes within C-terminus of LANA and to characterize the monoclonal antibodies (MAbs) against this protein, we expressed the C-terminal region at aa 794-1000 of LANA (pLANA-C) in Escherichia coli as a fusion protein. KSHV-positive human sera were able to recognize the recombinant LANA-C in the Western blot analysis and ELISA. Mapping of antigenic epitopes of pLANA-C by KSHV-positive human sera revealed two B cell antigenic epitopes located at aa 846-854 and aa 794-822. The MAb 3F11 recognized a region between at aa 840 to 846 of LANA and exhibited a strong and specific binding to both pLANA-C and native viral LANA. These findings showed that pLANA-C and MAb 3F11 could be used for the detection of KSHV antibodies in human sera and for the advanced study of biological functions of LANA.

Antiarrhythmic effect of atorvastatin on autoimmune myocarditis is mediated by improving myocardial repolarization

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, or statins, are known to inhibit cholesterol biosynthesis and prevent inflammation and oxidative stress. To explore the effects of atorvastatin on inflammatory progression and major cardiac electrophysiological changes in myocarditis, we used an animal model of experimental autoimmune myocarditis (EAM). In this model, BALB/c mice were treated with atorvastatin and we evaluated the levels of inflammation markers and currents of ionic channels that contribute to the duration of action potential (APD) of ventricular myocytes. We demonstrated that atorvastatin treatment attenuated inflammatory infiltration and suppressed the increase in TNF-alpha and IFN-gamma levels in EAM mouse hearts. In the whole-cell patch-clamp experiment, ventricular cardiomyocyte APD was prolonged in EAM group, and atorvastatin blocked this change. We further found that atorvastatin attenuated the significant decrease in outward potassium currents in EAM myocytes. Our results suggested that atorvastatin may ameliorate EAM progression by reducing inflammatory cytokine level. Atorvastatin exerted the antiarrhythmic effects by selectively affecting cardiomyocyte ion channel activity and therefore improves myocardial repolarization.

The effect of renal ischemia-reperfusion injury on expression of RAE-1 and H60 in mice kidney

INTRODUCTION

NKG2D, an activating receptor, may trigger NK and CD8+ T cells. Ligands for NKG2D and major histocompability complex class I chain-related antigen (MIC) have been reported to be expressed in rejected human renal allografts. MIC-NKG2D engagement may induce natural killer (NK) cell activation providing T-cell costimulation. We hypothesized that this interaction between innate and adaptive immunity may occur during kidney ischemia-reperfusion injury (IRI).

METHODS

Male C57BL/6 mice after right renal resection were subjected to 35 minutes of left renal ischemia: the ischemic group. Sham-operated mice underwent the same protocol without vascular occlusion. The sham and ischemic kidneys were removed at 2 to 7, 10, 14, or 28 days postoperatively. The normal, sham, and ischemic kidney tissues were collected for reverse-transcriptase polymerase chain reaction, and immunohistochemistry analysis of MIC homologues in mice (Rae-1 and H60).

RESULTS

Compared with no expression in sham control and normal kidneys, IRI caused mRNA expression of Rae-1 from 2 to 10 days postoperatively and protein expression of Rae-1 from 2 to 14 days postoperatively in ischemic kidneys. We observed no expression of H60 mRNA or protein in any kidney.

CONCLUSION

H60 transcripts have been reported to be present in the BALB/c background but not in C57BL/6. We found IRI did not cause H60 mRNA on protein expression in C57BL/6 kidneys. Rae-1 was absent in normal C57BL/6 kidneys. The IRI-induced expression of the NKG2D ligand, Rae-1, might activate NK and CD8+ T cells. Our results suggested that MIC may be an important link between innate and adaptive immunity in kidney IRI.

[Preparation and characterization of the monoclonal antibodies against Japanese encephalitis virus.]

BACKGROUND

To prepare mouse monoclonal antibodies (McAbs) against Japanese encephalitis virus (JEV)and evaluate their biological characteristics.

METHODS

McAbs against JEV were prepared by immunizing, fusing, cloning and screening. Their sensitivity, specificity, universality and neutralizing function were analyzed with ELISA, IFA, NT and Western blot.

RESULTS

Titers of three McAbs against JEV were higher than 106. Three McAbs only reacted with JEV and not with other nine arboviruses. F12.37 could react with ten strains of JEV and sensitively detected ten replicating strains of viruses in BHK cell. The strains P3 and SH03-103 of JEV were neutralized by F12.37, its titers of protecting 50% cell were 3.2x105 and 105. Western blot showed that F12.37 reacted with envelop(E)protein of JEV.

CONCLUSION

Three McAbs against JEV had high titer and good specificity. And F12.37 was very sensitive and universal in reacting with JEV, and neutralized JEV of Genotype I and Genotype .The binding site of F12.37 lays in E protein of JEV.

Study on energy metabolism in perioperative infants

OBJECTIVES

To evaluate resting energy expenditure (REE) in surgical infants and define the effects of the degree of stress on its level.

SUBJECTS AND METHODS

Between June 1999 and June 2003 forty-five infants awaiting surgery (boys/girls: 32/13) from the Department of Pediatric Surgery were entered in the study. Indirect calorimetry was used to measure the REE of all the patients before operation and 1 - 7 days after operation. Clinical data were collected, including age, weight, height, diagnosis, operative method, site and duration, and first day postoperative C-reactive protein (CRP) levels.

RESULTS

The REE before operation did not differ significantly from the postoperative values (paired t-test, p > 0.05). The predicted REE was significantly higher than the measured REE even before and after the operation (p < 0.01). REE values in the first three postoperative days were lower in the mild stress group than in the severe surgical stress group.

CONCLUSIONS

REE variation among the patients is relatively large. Changes in REE may be related to the degree of stress. Predicted REE values may be not a good reflection of measured REE.

Elimination of metformin-croscarmellose sodium interaction by competition

During analytical method development and validation, a strong charge interaction between metformin and croscarmellose sodium was observed when the aqueous solution containing metformin was spiked with croscarmellose sodium. The charge interaction resulted in the retention of metformin in croscarmellose sodium and caused a serious drug recovery problem. The percent recovery of metformin in the solution was much lower than its theoretical values, especially in the low metformin concentration range. To overcome the metformin-croscarmellose interaction, arginine was selected as a competitor for the binding sites on croscarmellose sodium. Because of the competition and stronger interaction between arginine and croscarmellose sodium than metformin and croscarmellose sodium, a complete recovery of metformin in presence of arginine in both low and high concentration ranges was achieved. The effect of arginine on the recovery of metformin and the competition mechanism are discussed in this paper.

Defect complexes in Re3+-doped magnesium sulphate phosphors

A series of magnesium sulphate phosphors MgSO4:RE3+,X ( RE = Dy, Tm, Eu and X = P, Mn) have been prepared and studied. Based on the experimental results of thermoluminescence (TL) emission spectra and dose responses studies, it is proposed that in these phosphors large defect complexes are formed, which include intrinsic imperfections and dopants. These defect complexes were formed in the course of preparation of phosphors and could be regarded as basic elements in the TL multi-stage processes. This defect model might be applicable to the most of TL materials.

TL and OSL of SrSO4 phosphors doped with Eu

The thermoluminescence (TL) and optically stimulated luminescence (OSL) of SrSO4:Eu (0.1 mol%) powder sample were studied. The TL and OSL emission spectrum are measured after irradiation (absorbed dose 100 Gy) of 90Sr source; both of them showed that the emission wavelength is at approximately 375 nm, which indicates that TL and OSL have the same luminescence centres, and the luminescence comes from transitions between the energy levels of Eu2+. The TL glow curves and OSL decay curves illustrate that there is only one main TL peak but two main components in OSL curves. By a comparative study of TL and OSL it is concluded that OSL traps are different from TL traps. The TL and OSL dose responses of SrSO4:Eu phosphor were measured, and it showed that phosphor has similar dose responses for OSL and TL.

Thermoluminescence glow curves and optical stimulated luminescence of undoped alpha-Al2O3 crystals

The characteristics of thermoluminescence (TL) and optical stimulated luminescence (OSL) in undoped alpha-Al2O3 single crystals were studied. The TL glow curves of the crystal samples irradiated at various dose levels were measured by RisØ TL/OSL-DA-15B/C reader with U-340 or 7-59 filters at different heating rates. The glow peaks measured with U-340 at approximately 210 degrees C of the undoped alpha-Al2O3 can be well fitted by first-order kinetic equation whereas the glow peaks measured with 7-59 filters are a composite of two first-order glow peaks. It indicates that the TL glow curves are dependent upon the filter used in the reader that is related to the emission spectra of luminescence materials. The OSL were also measured and fitted by two exponential functions to get the luminescence intensities. The TL and OSL dose responses of the undoped alpha-Al2O3 crystal were obtained in the dose range of 0.12-248 Gy and fitted by the composite action dose-response function to get nonlinear characteristic parameters. The TL and OSL dose responses are linear-sublinear.

In vitro expanded human CD4+CD25+ regulatory T cells suppress effector T cell proliferation

Regulatory T cells (Tregs) have been shown to be critical in the balance between autoimmunity and tolerance and have been implicated in several human autoimmune diseases. However, the small number of Tregs in peripheral blood limits their therapeutic potential. Therefore, we developed a protocol that would allow for the expansion of Tregs while retaining their suppressive activity. We isolated CD4+CD25 hi cells from human peripheral blood and expanded them in vitro in the presence of anti-CD3 and anti-CD28 magnetic Xcyte Dynabeads and high concentrations of exogenous Interleukin (IL)-2. Tregs were effectively expanded up to 200-fold while maintaining surface expression of CD25 and other markers of Tregs: CD62L, HLA-DR, CCR6, and FOXP3. The expanded Tregs suppressed proliferation and cytokine secretion of responder PBMCs in co-cultures stimulated with anti-CD3 or alloantigen. Treg expansion is a critical first step before consideration of Tregs as a therapeutic intervention in patients with autoimmune or graft-versus-host disease.

Recombinant adeno-associated virus-mediated alpha-1 antitrypsin gene therapy prevents type I diabetes in NOD mice

Type I diabetes results from an autoimmune destruction of the insulin-producing pancreatic beta cells. Although the exact immunologic processes underlying this disease are unclear, increasing evidence suggests that immunosuppressive, immunoregulatory and anti-inflammatory agents can interrupt the progression of the disease. Alpha 1 antitrypsin (AAT) is a multifunctional serine proteinase inhibitor (serpin) that also displays a wide range of anti-inflammatory properties. To test the ability of AAT to modulate the development of type I diabetes, we performed a series of investigations involving recombinant adeno-associated virus vector (rAAV)-mediated gene delivery of human alpha-1 antitrypsin (hAAT) to nonobese diabetic (NOD) mice. Recombinant AAV-expressing hAAT (rAAV2-CB-AT) was administered intramuscularly to 4-week-old female NOD mice (1 x 10(10) i.u./mouse). A single injection of this vector reduced the intensity of insulitis, the levels of insulin autoantibodies, and the frequency of overt type I diabetes (30% (3/10) at 32 weeks of age versus 70% (7/10) in controls). Transgene expression at the injection sites was confirmed by immunostaining. Interestingly, antibodies against hAAT were present in a majority of the vector-injected mice and circulating hAAT was undetectable when assessed 10 weeks postinjection. This study suggests a potential therapeutic role for AAT in preventing type I diabetes as well as the ability of AAV gene therapy-based approaches to ameliorate disease effectively.

Mathematical analysis of a model describing evolution of an asexual population in a changing environment

We investigate a mathematical model for an asexual population with non-overlapping (discrete) generations, that exists in a changing environment. Sexual populations are also briefly discussed at the end of the paper. It is assumed that selection occurs on the value of a single polygenic trait, which is controlled by a finite number of loci with discrete-effect alleles. The environmental change results in a moving fitness optimum, causing the trait to be subject to a combination of stabilising and directional selection. This model is different from that investigated by Waxman and Peck [Genetics 153 (1999) 1041] where overlapping generations and continuous effect alleles were considered. In this paper, we consider non-overlapping generations and discrete effect alleles. However in [Genetics 153 (1999) 1041] and the present work, there is the same pattern of environmental change, namely a constant rate of change of the optimum. From [Genetics 153 (1999) 1041], no rigorous theoretical conclusion can be drawn about the form of the solutions as t grows large. Numerical work carried out in [Genetics 153 (1999) 1041] suggests that the solution is a lagged travelling wave solution, but no mathematical proof exists for the continuous model. Only partial results, regarding existence of travelling wave solutions and perturbed solutions, have been established (see [Nonlin. Anal. 53 (2003) 683; An integral equation describing an asexual population in a changing environment, Preprint]). For the discrete case of this paper, under the assumption that the ratio between the unit of genotypic value and the speed of environment change is a rational number, we are able to give rigorous proof of the following conclusion: the population follows the environmental change with a small lag behind, moreover, the lag is represented using a calculable quantity.

Targeting recombinant adeno-associated virus vectors to enhance gene transfer to pancreatic islets and liver

Human pancreatic islet cells and hepatocytes represent the two most likely target cells for genetic therapy of type I diabetes. However, limits to the efficiency of rAAV serotype 2 (rAAV2)-mediated gene transfer have been reported for both of these cell targets. Here we report that nonserotype 2 AAV capsids can mediate more efficient transduction of islet cells, with AAV1 being the most efficient serotype in murine islets, suggesting that receptor abundance could be limiting. In order to test this, we generated rAAV particles that display a ligand (ApoE) that targets the low-density lipoprotein receptor, which is present on both of these cell types. The rAAV/ApoE viruses greatly enhanced the efficiency of transduction of both islet cells ex vivo and murine hepatocytes in vivo when compared to native rAAV2 serotype (220- and four-fold, respectively). The use of receptor-targeted rAAV particles may circumvent the lower abundance of receptors on certain nonpermissive cell types.

Swimming and ammonia toxicity in salmonids: the effect of sub lethal ammonia exposure on the swimming performance of coho salmon and the acute toxicity of ammonia in swimming and resting rainbow trout

This study tested the hypothesis that swimming exacerbates ammonia toxicity in fish. Both sub-lethal and acute toxicity testing was conducted in a swim tunnel on swimming and resting coho salmon and rainbow trout, respectively. The sub lethal tests on coho salmon also considered the compartmentalization of ammonia within the fish. Coho salmon showed a significant linear decrease in U(crit) both with increasing water ammonia (0, 0.02, 0.04 and 0.08 mg per l NH3) and increasing plasma ammonia. Data collected included plasma pH and ammonia, muscle pH and ammonia and muscle membrane potential. Based on results found in these experiments it was concluded that the reduction in swimming performance was due to both metabolic challenges as well as depolarization of white muscle. Acute toxicity testing on swimming and resting rainbow trout revealed that swimming at (60% U(crit) or approximately 2.2 body lengths/s) decreased the LC50 level from 207+/-21.99 mg N per l in resting fish to 32.38+/-10.81. The LC50 for resting fish was significantly higher than that for swimming fish. The acute value set forth by the US EPA at the same pH is 36.1 mg N per l and may not protect swimming fish. In addition the effect of water hardness on ammonia toxicity was considered. It was found that increased water calcium ameliorates ammonia toxicity in fish living in high pH water.

Comparative study of catheter-mediated gene transfer into heart

OBJECTIVE

To investigate the feasibility and features of 3 catheter-mediated approaches of gene transfer into heart, including direct myocardial injection (DMI), coronary artery perfusion (CAP), and intrapericardial cavity injection (ICI).

METHODS

Fifteen dogs were used, and 0.3 ml (1 x 10(9) pfu) of an adenovirus (Adex1SR LacZ) was injected into the heart by 3 methods. The dogs were killed 5 days following injection, and gene expressions in heart and liver were evaluated by histochemical analysis.

RESULTS

The results showed that (1) the CAP method was relatively less damaging and induced sparse LacZ expression in the myocardium, and the gene expression was also found in both vessels within the myocardium and liver; (2) gene transfer by DMI resulted in intense LacZ expression around the injection accompanied by a local inflammatory response; (3) LacZ expression elicited by ICI was detected in either the inner surface of the parietal pericardium or epicardial surface of the heart, and also in the myocardium underlying the visceral pericardium.

CONCLUSION

Three catheter-mediated methods of gene transfer into the heart may be used and a reasonable approach should be chosen according to purpose.

Thermoluminescence of MgSO4 doped with Eu and P impurities

CaSO4:Eu, MgSO4:Eu and MgSO4:Eu,P phosphors have been prepared and their thermoluminescence (TL) characteristics were studied. A main glow peak due to Eu2+ ions is seen at approximately 146 degrees C and 440 nm and glow peaks at approximately 145 degrees C, approximately 190 degrees C, approximately 260 degrees C and approximately 360 degrees C for 590 nm and 625 nm wavelengths are identified as Eu3+ ion emissions in MgSO4:Eu. Emission spectra in MgSO4:Eu and the MgSO4:Eu,P show that the MgSO4:Eu3+ glow peak at 260 degrees C for 590 nm and 625 nm shifts to 280 degrees C with enhanced intensity while the Eu2+ ion glow peak at 146 degrees C remains but with reduced intensity. The main glow peak at approximately 146 degrees C and 440 nm from Eu2+ ions shows significant difference from the characteristic glow peaks of Eu3+ ions. It is observed that the wavelength of the Eu2+ ion glow peak is inversely proportional to the radius of the cation of the host sulphate in alkaline-earth sulphate phosphors. By contrast the wavelengths of the Eu3+ ion glow peaks remain unchanged in different sulphates. Besides, the glow curve at approximately 146 degrees C obtained using a conventional blue sensitive reader shows simply the first order kinetics. It is concluded that the luminescence centres and distribution of traps related to Eu2+ ions are different from that of Eu3+ ions in MgSO4:Eu and MgSO4:Eu,P phosphors.

Morphologically Controlled Proton-Conducting Membranes Using Graft Polymers Possessing Block Copolymer Graft Chains

Ionic graft membranes comprising macromonomeric poly(styrene-block-styrene sulfonic acid) grafted polystyrene [PS-g-mac(PS-b-PSSA)] polymers were prepared by copolymerization of styrene and poly(styrene-block-sodium styrene sulfonate) (PS-b-PSSNa) macromonomers followed by ion-exchange. The latter were prepared with controlled molecular weight by stable free radical polymerization. Membranes exhibit varying degrees of phase separation. Membranes of low ion content are comprised of isolated ionic domains and exhibit low ionic conductivity. Increasing the number density of ionic graft chains in the polymer results in a network of nanochannels and a dramatic increase in ion conductivity. In comparison to analogous macromonomeric poly(styrene sulfonic acid) grafted polystyrene (PS-g-macPSSA) membranes, of similar ion exchange capacity (IEC) and PSSA chain length, dehydrated PS-g-mac(PS-b-PSSA) membranes consist of smaller, more densely connected ionic domains; however, water sorption and ionic conductivity are similar.

ERM-dependent movement of CD43 defines a novel protein complex distal to the immunological synapse

The large mucin CD43 is actively excluded from T cell/APC interaction sites, concentrating in a membrane domain distal to the site of TCR engagement. The cytoplasmic region of CD43 was necessary and sufficient for this antipodal movement. ERM cytoskeletal adaptor proteins colocalized with CD43 in this domain. An ERM dominant-negative mutant blocked the distal accumulation of CD43 and another known ERM binding protein, Rho-GDI. Inhibition of ERM function decreased the production of IL-2 and IFNgamma, without affecting PKC(theta) focusing or CD69 upregulation. These results indicate that ERM proteins organize a complex distal to the T cell/APC interaction site and provide evidence that full T cell activation may involve removal of inhibitory proteins from the immunological synapse.

Antigen-specific blockade of T cells in vivo using dimeric MHC peptide

Ag-specific immune tolerance in clinical organ transplantation is currently an unrealized but critical goal of transplant biology. The specificity and avidity of multimerized MHC-peptide complexes suggests their potential ability to modulate T cell sensitization and effector functions. In this study, we examined the ability of MHC-peptide dimers to modulate T cell function both in vitro and in vivo. Soluble MHC dimers induced modulation of surface TCR expression and inhibited T cell cytolytic activity at nanomolar concentrations in vitro. Furthermore, engagement of TCR by soluble dimers resulted in phosphorylation of the TCR zeta-chain and recruitment and phosphorylation of zeta-associated protein-70 to the signaling complex, the latter of which increased upon dimer cross-linking. Significantly, Ag-specific inhibition of an alloreactive TCR-transgenic T cell population in vivo resulted in consequent outgrowth of an allogeneic tumor. The prolonged Ag-specific suppression of expansion and/or effector function of cognate T cells in vivo suggests that soluble MHC dimers may be a means of inducing sustained Ag-specific T cell unresponsiveness in vivo.

Role of cyclic AMP responsive element in the UVB induction of cyclooxygenase-2 transcription in human keratinocytes

It has been shown that UVB irradiation induces expression of COX-2 and up-regulation of COX-2 plays a functional role in UVB tumor promotion. In this study, we examined the cis-elements in the human COX-2 promoter that may be responsible for the UVB induction of COX-2. Analyses with the COX-2 promoter region revealed that the cyclic AMP responsive element near the TATA box was essential for both basal and UVB induced COX-2 expression. This was further supported by studies using a dominant negative mutant of CREB, which strongly inhibited the activity of COX-2 promoter. Electrophoretic mobility shift assays indicated that CREB and ATF-1 were the major proteins binding to the COX-2 CRE. CREB and ATF-1 were phosphorylated upon UVB treatment, and SB202190, a p38 MAPK inhibitor, decreased the phosphorylation of CREB/ATF-1 and suppressed COX-2 promoter activity. In contrast, treatment with forskolin, an activator of adenylyl cyclase, led to phosphorylation of CREB and ATF-1 and activation of COX-2 promoter. Finally, enhanced binding of phospho-CREB/ATF-1 to the COX-2 CRE was observed after UVB induction. Thus, one signaling pathway for UVB induction of human COX-2 involves activation of p38, subsequent phosphorylation of CREB/ATF-1, and activation of the COX-2 CRE through enhanced binding of phosphorylated CREB/ATF-1.

Vesicle trafficking and cell surface membrane patchiness

Membrane proteins and lipids often appear to be distributed in patches on the cell surface. These patches are often assumed to be membrane domains, arising from specific molecular associations. However, a computer simulation (Gheber and Edidin, 1999) shows that membrane patchiness may result from a combination of vesicle trafficking and dynamic barriers to lateral mobility. The simulation predicts that the steady-state patches of proteins and lipids seen on the cell surface will decay if vesicle trafficking is inhibited. To test this prediction, we compared the apparent sizes and intensities of patches of class I HLA molecules, integral membrane proteins, before and after inhibiting endocytic vesicle traffic from the cell surface, either by incubation in hypertonic medium or by expression of a dominant-negative mutant dynamin. As predicted by the simulation, the apparent sizes of HLA patches increased, whereas their intensities decreased after endocytosis and vesicle trafficking were inhibited.

[Assay of trace elements and heavy metals in different growth stages of Ganoderma lucidum]

The trace elements and heavy metals in the different growth stages of Ganoderma lucidum were analyzed by ICP-MS, AFS and AAS. The fermented mycelia, fruiting bodies and spore contained all kinds of detected trace elements and heavy metals, the contents of which were higher in spore. The content of Se was same in different growth stages. Ganoderma lucidum had the ability of bio-enrichment of Ge.

Role of p38 MAP kinases and ERK in mediating ultraviolet-B induced cyclooxygenase-2 gene expression in human keratinocytes

The roles of p38 MAP kinases and ERK in UVB induced cox-2 gene expression were studied in a human keratinocyte cell line, HaCaT. UVB significantly increased cox-2 gene expression at both protein and mRNA levels. As we reported previously, p38 and ERK were significantly activated after UVB irradiation in HaCaT cells. In addition, treating the cells with p38 inhibitor SB202190 or MEK inhibitor PD98059 specifically inhibited UVB induced p38 or ERK activation, respectively. In this study, we further examined the roles of p38 and ERK in UVB induced cox-2 gene expression in HaCaT cells. We found that SB202190 strongly inhibited UVB induced COX-2 protein expression at different time points and various UVB doses. Furthermore, SB202190 markedly inhibited UVB induced cox-2 mRNA. Our data indicated that ERK did not play a role in UVB induced cox-2 gene expression in human keratinocytes since suppression of ERK did not significantly alter UVB induced increase of COX-2 protein and mRNA. These results suggested, for the first time, that activation of p38 is required for UVB induced cox-2 gene expression in human keratinocytes. Since cox-2 expression plays an important role in UV carcinogenesis, p38 could be a potential molecular target for chemoprevention of skin cancer.

Roles of Akt and glycogen synthase kinase 3beta in the ultraviolet B induction of cyclooxygenase-2 transcription in human keratinocytes

Ultraviolet B (UVB)-induced cyclooxygenase-2 (COX-2) expression plays an important role in UVB tumor promotion. We examined whether Akt and glycogen synthase kinase 3beta (GSK-3beta), components of the phosphatidylinositol 3'-kinase pathway, are involved in UVB induction of COX-2 transcription. UVB caused Akt phosphorylation at both Thr-308 and Ser-473 that was inhibited by LY294002, a phosphatidylinositol 3'-kinase inhibitor. LY294002 also decreased the expression of endogenous COX-2 protein and a luciferase construct driven by COX-2 promoter. Similarly, UVB caused phosphorylation of GSK-3beta (Ser-9) and presumably inactivation of GSK-3beta. Inhibition of GSK-3beta by lithium induced endogenous COX-2 protein expression and COX-2 promoter activity. Finally, overexpression of a dominant-negative Akt mutant or wild-type GSK-3beta suppressed UVB-mediated induction of COX-2 promoter. These studies suggest that inactivation of GSK-3beta through activation of Akt plays an important role in the UVB induction of COX-2 transcription.

Elimination of active tad elements during the sexual phase of the Neurospora crassa life cycle

Tad is an active LINE-like retrotransposon isolated from the Adiopodoumé strain of Neurospora crassa. Extensive analysis of other Neurospora strains has revealed no other strain with active Tad, but all strains tested have multiple copies of defective Tad elements. We have examined the ability of Tad to survive during the sexual cycle of Neurospora and find that active Tad is rapidly eliminated. The characteristics of this elimination suggest that the repeat-induced point mutation (RIP) mechanism was responsible. By the use of transformation to switch the mating type of the Adiopodoumé strain we concluded that this strain is not defective in the RIP process. Analysis of defective Tad elements isolated from a variety of strains indicates that the major difference between these elements and active Tad is due to the presence of a large number of G-C to A-T transition mutations. This would be expected if the changes were due primarily to the RIP process. Mapping of a selection of defective Tad elements reveals that they are present on all of the chromosomes; however, many of the elements are not widely shared among strains. This suggests that repeated introduction and elimination of Tad elements has occurred. Mechanisms that might be responsible for this repeated introduction are discussed.

[Studies on calluses induced from various explants of Cistanche deserticola]

Calluses were induced from various explants (flower, stem, bud and squama) of Cistanche deserticola Y.C.Ma and compared with each other. The result showed that the inducement rate of ovary and stem were higher than that of other explants which the inducement time was short and the characters of calluses were good. The effect of basal culture medium added hormone on callus reproduction was also studied. The result showed that B5 culture medium added 1 mg/L IBA and 2 mg/L 6-BA was optimal.

[Maintenance ration and conversion efficiency of Hyporhamphus sajori]

The maintenance ration and conversion efficiency of Japanese halfbeak, Hyporhamphus sajori were tested with enclosures installed in a shrimp raising pond. The results showed that there existed an evident relationship between daily ration(DR) and growth rate(GR) of the fish, GR = 140.37 DR - 24.03. The conversion efficiency was 13.96% in biomass or 16.12% in energy. The maintenance ration was 17.12% and 20.39% of body weight in terms of growth rate and specific growth rate, respectively, indicating that it could be deduced from growth rate quite differently from that from specific growth rate in the same experiment. The abnormal growth rate appeared when daily ration was below 3.30% of body weight, implied that Japanese halfbeak may get other food resources besides supplied net zooplankton.