Intracoronary, adenovirus-mediated Akt gene transfer in heart limits infarct size following ischemia-reperfusion injury in vivo

BACKGROUND

Previous data have shown that enhanced Akt signaling inhibits cardiac myocyte apoptosis in vitro and in vivo. To elucidate the contribution of apoptosis to the pathogenesis of the infarct, we investigated whether intra-coronary Akt gene delivery could reduce gross infarct size following ischemia/reperfusion injury.

METHODS AND RESULTS

Replication-defective adenoviral constructs encoding a myristoylated, constitutively-active form of Akt (myrAkt) or beta -galactosidase were delivered to rat hearts by intracoronary perfusion. Twenty-four h after gene transduction, hearts in both groups underwent 45 min of ischemia followed by 4 h of reperfusion. A third group of animals also underwent ischemia-reperfusion injury but were not transduced with an adenoviral vector. The proportion of the left ventricle at risk was not different among the experimental groups. However, infarct size as a proportion of the area at risk was significantly lower in myrAkt-treated group than in the beta -galactosidase treated group or in the control group that was not subject to intracoronary perfusion (myrAkt=20.9+/-2.7%v beta -galactosidase=56.1+/-3.9% and control=46.2+/-4.6%, P<0.05), as was infarct size as a proportion of the total left ventricle (myrAkt=11.4+/-3.2 v beta -galactosidase=32. 9+/-3.3 and control=23.5+/-3.0, P<0.05).

CONCLUSIONS

These data demonstrate that Akt signaling limits infarct size following ischemia/reperfusion injury and they indicate that the activation of this pathway may be useful in protecting against myocardial loss in the diseased heart.

Structure-function study and anti-HIV activity of synthetic peptide analogues derived from viral chemokine vMIP-II

The viral macrophage inflammatory protein II (vMIP-II) shows a broad spectrum interaction with both CC and CXC chemokine receptors including CCR5 and CXCR4, two principal coreceptors for the cellular entry of human immunodeficiency virus type 1 (HIV-1). Recently, we have shown that a synthetic peptide derived from the N-terminus of vMIP-II, designated as V1, is a potent antagonist of CXCR4 but not CCR5 [Zhou, N., et al. (2000) Biochemistry 39, 3782-3787]. In this study, we synthesized a series of new peptides derived from other regions of vMIP-II and characterized their binding activities with both CXCR4 and CCR5. The results provided further support for the notion that the N-terminus of vMIP-II is the major determinant for CXCR4 recognition and that vMIP-II probably interacts with other chemokine receptors such as CCR5 with different sequence and conformational determinants. To understand the structure-function relationship of V1 peptide, its solution conformation was studied using circular dichroism spectroscopy, which showed a random conformation similar to that of the corresponding N-terminus in native vMIP-II. In addition, we synthesized a series of mutant analogues of V1 containing alanine, glycine, or phenylalanine substitution at various positions. Residues Val-1, Arg-7, and Lys-9 of V1 peptide were found to be critical for receptor interaction, because single alanine replacement at these positions dramatically decreased peptide binding to CXCR4. In contrast, alanine or phenylalanine substitution at Cys-11 led to significant enhancement in peptide affinity for CXCR4. Finally, we showed that V1 peptide inhibits HIV-1 replication in CXCR4(+) T-cell lines. These studies provide new insights into the structure-function relationship of V1 peptide and demonstrate that this peptide may be a lead for the development of therapeutic agents.

Development of an affordable diaphragmatic pump for cardiopulmonary bypass: an in vivo evaluation

A new diaphragmatic pump (L-Y pump) and its drive unit were developed in our institute. The pump has a priming volume of 80 ml. The pump housing is 72 mm in diameter and 42 mm in height. Its total weight is 139 g. To assess and confirm the function and controllability of this pump, comparative studies of cardiopulmonary bypass (CPB) with L-Y pump (group A) and conventional roller pump (Group B) were performed using dogs. Both pumps provided pump flow of 90 to 100 ml/kg/min. The hemodynamics of both groups were stable and within the normal range. No leakage or thrombus formation was observed in the L-Y pump. All biochemistry data showed no significant differences between the 2 groups. This data demonstrated low plasma-free hemoglobin levels in the L-Y pump group; after 120 min of CPB, mean plasma free hemoglobin levels were 48.7 +/- 8.6 mg/dl in the roller pump group and 21.4 +/- 7.1 mg/dl in the L-Y pump group, and minimal hemolysis was indicated. In conclusion, this L-Y pump and its controller system might be useful for CPB in terms of its low hemolysis and good pump quality. This pump demonstrated easy manipulation, good controllability, and provided a sufficient pulsatile flow. This pump is suitable not only for CPB, but also as a long-term circulatory support system.

[The modulating effect of panax pseudoginseng wall saponins on the DAG-PKC signal pathway and TNF secretion of macrophages]

OBJECTIVE

To explore the roles of panax pseudoginseng wall saponins on the DAG-PKC signal pathway and TNF secretion of macrophages.

METHODS

The changes of the activities of postburn inositol lipid signal system factors such as PLC, DAG, cytomembrane PKC, cytoplasma PKC, and intracellular calcium concentration and the secretory amount of macrophage TNF were observed.

RESULTS

Panax pseudoginseng wall saponins could reduce the increased PLC activity from 57.58 +/- 8.19 to 27.00 +/- 2.31 and the intracellular calcium concentration from 393.18 +/- 392.62 to 90.56 +/- 7.21. With the role of panax pseudoginseng wall saponins, DAG activity reduced from 488.10 +/- 40.20 to 288.30 +/- 30.00, cytomembrane PKC activity decreased from 3081.50 +/- 698.50 to 1699.50 +/- 218.50, and cytoplasmic PKC activity from 2 188.60 +/- 258.30 to 848.40 +/- 138.30. The secretory TNF amount of macrophage decreased by 55%.

CONCLUSION

Panax pseudoginseng wall saponins might play an very important role in the modulating of the DAG-PKC signal pathway and decreased TNF secretion of macrophage.

Raf-1/MEK/MAPK pathway is necessary for the G2/M transition induced by nocodazole

The dynamic balance between polymerization and depolymerization of microtubules is critical for cells to enter and exit mitosis, and drugs that disrupt this balance, such as taxol, colchicine, and nocodazole, arrest the cell cycle in mitosis. Although the Raf/MEK/MAPK pathway can be activated by these drugs, its role in mitosis has not been addressed. Here, we characterize activation of Raf/MEK/MAPK by nocodazole when mitosis is induced. We find that at early time points (up to 3 h) in nocodazole induction, Raf/MEK/MAPK is activated, and inhibition of MAPK activation by a MEK inhibitor, PD98059 or U0126, reduces the number of cells entering mitosis by creating a block at G(2). At later time points and in mitosis, activation of MEK/MAPK is severely inhibited, even though Raf-1 activity remains high and can be further increased by growth factor. This inhibition is reversed when cells are released from metaphase and enter G(0)/G(1) phase. In addition, we find that binding of Raf-1 to 14-3-3 is progressively induced by nocodazole, reaching a maximum in mitosis, and that this binding is necessary to maintain mitotic Raf-1 activity. Our present study indicates that activation of the Raf/MEK/MAPK pathway is necessary for the G(2)/M progression.

The relationship of hepatitis B virus infection between adults and their children in Guangxi Province, China

BACKGROUND/AIM

This study aimed to describe the seroepidemiology of hepatitis B virus (HBV) infection, with emphasis on transmission of HBV infection between adults and their children.

METHODS

We analyzed the hepatitis sero-survey data collected from 2132 persons aged 1-59 years (624 families) in Guangxi Province, China, 1992. Blood was tested for the presence of the hepatitis B surface antigen (HBsAg), the antibody to hepatitis B core antigen (anti-HBc), and the antibody to hepatitis B surface antigen (anti-HBs).

RESULTS

Of the 2132 persons surveyed, 119 (5.6%) reported receiving HBV vaccination. Among those persons who did not receive HBV vaccination, 19% were HBsAg positive (current HBV infection) and 57% had a past HBV infection (they were HBsAg negative and either anti-HBc positive or anti-HBs positive). Among 519 children aged 1-10 years who did not receive HBV vaccination, 21% had current HBV infection and 37% had past HBV infection. Among 289 children of both parents who were HBsAg negative, 16% had current HBV infection and 36% had past HBV infection.

CONCLUSIONS

The high prevalence of community-acquired HBV infection in children and the low HBV vaccination coverage in Guangxi should alert public health agencies to re-examine their current policies for preventing HBV transmission.

[Preventive effects of three kinds of inactive vaccines against epidemic hemorrhagic fever (EHF) after 5 years of vaccination]

OBJECTIVE

To observe the safety and the preventive effects of three kinds of vaccines as Mongolian gerbils kidney vaccine, mouse brains vaccine and hamster kidney vaccine inoculated 5 years ago.

METHODS

Field study and laboratory tests were carried out by random grouping and IFAT, MCPENT, ELISA, HI tests.

RESULTS

The antibody-dependent enhancement did not appear in all individuals who received vaccines after four or five years. The seroconversion rates of MCPENT were 8.97%, 11.76% and 18.75% while the seroconversion rates of IFAT were 20.73%, 30.22% and 23.40% respectively for Mongolian gerbils kidney vaccine, mouse brains vaccine and hamster kidney vaccine. The protection rates were 100% for all three kinds of inactive vaccines which showed good epidemiological efficacy.

CONCLUSION

The vaccines can protect clinical infection of EHF effectively after four or five years of the initial vaccination.

Progress in the molecular genetic research of multinodular goiter

Multinodular goiter is a worldwide-distributed disease, but yet its pathology and genetic etiology are not clear. At present, most researches have been restrained to traditional epidemiological survey and the disease has been rarely studied at the level of molecular genetics. The pathogenesis of multinodular goiter, as is generally accepted by most researchers, can be attributed to many factors such as hormones, growth factors and the inherent functional heterogeneity of thyroid follicles. Since hormone and iodine metabolization are widely recognized as a major mechanism in determining the formation of multinodular goiter, some reports in literature are mainly focused on such genes that are responsible for hormone synthesis and iodine metabolization. Mapping experimental data were available to support location of multinodular goiter gene(s) onto chromosome 14q by whole genome scanning in a large pedigree analysis. Additional data, particularly those extracted from large scaled marker-assisted mapping experiments, are important so as to confirm the gene location, to improve resolution of the location, and finally to dissect the genes underlying the disease at molecular level.

Younger and older adults' recall of typical and atypical actions from script-based text: evidence for interruption and bizarre-imagery effects

In the present research, younger (mean age 20) and older (mean age 78) adults' perception and recall of scripted and nonscripted actions were examined. Two primary types of nonscripted or atypical actions were presented: those that interrupted the sequence of the script and those that were irrelevant to the script. Script-irrelevant actions also varied in terms of how plausible they were in relationship to both the sentence they were embedded in and the context of the story. Across experiments, both younger and older adults recalled script-interruptive actions better than all other actions, including script actions. In addition, an unexpected finding was that both younger and older adults recalled implausible (bizarre) script-irrelevant actions better than script actions. This latter finding suggests that a bizarre-imagery effect may operate in both younger and older adults. Older adults' better recall of atypical actions over script actions is noteworthy, as these results question the assumption that older adults show an increased reliance on their schematic knowledge structures to recall. Contrary to expectations, older adults showed better recall of actions that required more active story integration (interruptive and implausible atypical actions) than actions requiring less integration (script and plausible atypical actions).

The HMG-CoA reductase inhibitor simvastatin activates the protein kinase Akt and promotes angiogenesis in normocholesterolemic animals

Recent studies suggest that statins can function to protect the vasculature in a manner that is independent of their lipid-lowering activity. We show here that statins rapidly activate the protein kinase Akt/PKB in endothelial cells. Accordingly, simvastatin enhanced phosphorylation of the endogenous Akt substrate endothelial nitric oxide synthase (eNOS), inhibited apoptosis and accelerated vascular structure formation in vitro in an Akt-dependent manner. Similar to vascular endothelial growth factor (VEGF) treatment, both simvastatin administration and enhanced Akt signaling in the endothelium promoted angiogenesis in ischemic limbs of normocholesterolemic rabbits. Therefore, activation of Akt represents a mechanism that can account for some of the beneficial side effects of statins, including the promotion of new blood vessel growth.

[The research and manufacture of the pneumatic left ventricular assist pump]

The manufacturing methods and testing results of the pneumatic left ventricular assist pump(L-Y pump) are introduced in this paper. The results demonstrate that L-Y pump is reliable, biocompatible and in keeping with the clinical requirements.

Acute modulation of endothelial Akt/PKB activity alters nitric oxide-dependent vasomotor activity in vivo

The serine/threonine protein kinase Akt (protein kinase B) phosphorylates endothelial cell nitric oxide synthase (eNOS) and enhances its ability to generate nitric oxide (NO). Because NO is an important regulator of vasomotor tone, we investigated whether Akt can regulate endothelium-dependent vasomotion in vivo using a rabbit femoral artery model of gene transfer. The endothelium of isolated femoral arteries was infected with replication-defective adenoviral constructs expressing beta-galactosidase, constitutively-active Akt (myr-Akt), or dominant-negative Akt (dn-Akt). Femoral arteries transduced with myr-Akt showed a significant increase in resting diameter and blood flow, as assessed by angiography and Doppler flow measurements, respectively. L-NAME, an eNOS inhibitor, blocked myr-Akt-mediated vasodilatation. In contrast, endothelium-dependent vasodilatation in response to acetylcholine was attenuated in vessels transduced with dn-Akt, although these vessels showed normal responses to nitroglycerin, an endothelium-independent vasodilator. Similarly, relaxation of murine aorta ex vivo in response to acetylcholine, but not nitroglycerin, was inhibited by transduction of dn-Akt to the endothelium. These data provide evidence that Akt functions as key regulator of vasomotor tone in vivo.

Expression of wild-type and noncleavable Fas ligand by tetracycline-regulated adenoviral vectors to limit intimal hyperplasia in vascular lesions

Proliferation of vascular smooth muscle cells (VSMCs) and the infiltration of T cells and macrophages into vessel wall are considered to be important for intimal lesion formation after balloon angioplasty. Previous studies have shown that Fas ligand (FasL) gene transfer to balloon-injured vessels inhibits lesion formation by killing both proliferating VSMCs and infiltrating inflammatory cells. Here, we describe the construction and utility of a binary, tetracycline-regulated adenovirus system that provides controlled transgene expression in vitro and in vivo. In this system, optimal transgene expression required cotransfection with an adenovirus encoding the tetracycline-dependent trans-activator (rtTA) and induction with doxycycline hydrochloride (DOX), an analog of tetracycline. Using this system, adenovirus constructs were designed that allow regulated expression of wild-type FasL and a noncleavable mutant of FasL (FasL-NC). Transduction of FasL and FasL-NC induced similar extents of apoptosis in proliferating VSMCs in vitro in a manner that was dependent on the doses of the rtTA adenovirus and the presence of DOX in the medium. Furthermore, inhibition of intimal hyperplasia in injured carotid arteries by FasL or FasL-NC transduction was also dependent on cotransfection with the rtTA adenovirus and administration of DOX by subcutaneous injection. In contrast to wild-type FasL, transduction of FasL-NC did not result in the production of soluble (cleaved) FasL in the medium of infected cells in vitro, or in the serum of rats after local gene transfer to carotid arteries. In conclusion, this binary tetracycline-inducible adenovirus system may allow for safer delivery of cytotoxic genes for therapeutic purposes.

High-frequency intrachromosomal gene conversion induced by triplex-forming oligonucleotides microinjected into mouse cells

To test the ability of triple helix-forming oligonucleotides (TFOs) to promote recombination within chromosomal sites in mammalian cells, a mouse LTK(-) cell line was established carrying two mutant copies of the herpes simplex virus thymidine kinase (TK) gene as direct repeats in a single chromosomal locus. Recombination between these repeats can produce a functional TK gene and occurs at a spontaneous frequency of 4 x 10(-6) under standard culture conditions. When cells were microinjected with TFOs designed to bind to a 30-bp polypurine site situated between the two TK genes, recombination was observed at frequencies in the range of 1%, 2,500-fold above the background. Recombination was induced efficiently by injection of both psoralen-conjugated TFOs (followed by long-wave UVA light; 1. 2%) and unconjugated TFOs alone (1.0%). Control oligomers of scrambled sequence but identical base composition were ineffective, and no TFO-induced recombination was seen in a control LTK(-) cell line carrying an otherwise identical dual TK gene construct lacking the 30-bp polypurine target site. TFOs transfected with cationic lipids also induced recombinants in a highly sequence-specific manner but were less effective, with induced recombination frequencies of 6- to 7-fold over background. Examination of the TFO-induced recombinants by genomic Southern blotting revealed gene conversion events in which both TK genes were retained, but either the upstream (57%) or the downstream gene (43%) was corrected to wild type. These results suggest that, with efficient intracellular delivery, TFOs may be effective tools to promote site-specific recombination and targeted modification of chromosomal loci.

[Effect of hydroxyurea combined with interferon-alpha on growth and apoptosis-related oncogene expression of K562 cells]

OBJECTIVE

To observe the effect of hydroxyurea (HU) alone and in combination with interferon-alpha (IFN-alpha) on the cell growth and cell death, and the related oncogene expression of chronic myelogenous leukemia (CML) cell line, K562 cells. To further investigate the molecular basis of combination therapy on CML by chemotherapeutants combined with cytokines.

METHODS

The proliferation and viability of K562 cells were detected by cell-counting and trypan blue dye exclusion test. The levels of bcr-abl, bax and c-myc gene expression in K562 cells incubated for 48 hours were examined using RT-PCR technique.

RESULTS

proliferation was suppressed and cell death process was accelerated by both HU and HU combined with IFN-alpha. HU significantly inhibited bcr-abl gene expression and increased bax gene expression level (both P < 0.05 as compared with that of control). Furthermore, IFN-alpha dose-dependently enhanced the regulatory effects of HU on bcr-abl and bax gene expression. HU alone and in combination with IFN-alpha suppressed slightly c-myc gene expression.

CONCLUSIONS

Both HU and HU combined with IFN-alpha can inhibit cell proliferation and promote cell death or apoptotic cell death by regulating the expression levels of the genes relating to cell proliferation and apoptosis. The molecular mechanism of HU and IFN-alpha synergistically acting on leukemic cells is further elucidated from the expression level of the related genes which control the balance of survival and death or apoptosis of the cells.

[Effects of IFN-alpha combined with IL-6 on cell growth and related genes expression and apoptosis of bone marrow cells from CGL patients]

OBJECTIVE

To investigate the effects of interferon-alpha (IFN-alpha) and IFN-alpha combined with interleukin-6 (IL-6) on cell growth and bcr/abl, bcl-2 and c-myc genes expression in the bone marrow mononuclear cells (MNC) from chronic granulocytic leukemia (CGL) patients.

METHODS

MNCs were cultured in liquid medium at the presence of IFN-alpha (200 U/ml) or IFN-alpha (200 U/ml) plus IL-6 (100 ng/ml). The viable cells were counted and the expression levels of beta-actin, bcr/abl, bcl-2 and c-myc genes were quantitatively detected by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

The cell growth was markedly inhibited by IFN-alpha, but the extent of the inhibition was slightly decreased when IFN-alpha combined with IL-6. The expression levels of bcr/abl and bcl-2 gene were reduced by IFN-alpha or IFN-alpha plus IL-6. The expression of c-myc gene was inhibited by IFN-alpha but promoted by IL-6.

CONCLUSIONS

Both IFN-alpha and IFN-alpha plus IL-6 can inhibit the expression of anti-apoptosis genes, and modulate the expression of c-myc. It is the possible mechanism of IFN-alpha therapy for CGL in chronic phase.

Interruption and bizarreness effects in the recall of script-based text

Recall of script, script-irrelevant, and script-interruptive actions in script-based stories was examined in four experiments. By varying the plausibility of the script-irrelevant and the script-interruptive actions, the bizarreness effect (i.e., enhanced recall for bizarre, implausible actions) was assessed within the context of script-based text. In addition, presentation of script-interruptive actions actions allowed for an assessment of the interruption effect (i.e., enhanced recall for interruptive actions). A bizarreness effect was found, to the extent that implausible script-irrelevant actions were better recalled than their more plausible counterparts and script actions. However, implausible actions were not better recalled than script-interruptive actions, nor did bizarreness significantly enhance recall of script-interruptive actions. These results are discussed in terms of recent assumptions underlying interruptions underlying interruption and bizarreness effects, and in terms of recent assumptions about how scripted and nonscripted actions are retained in memory.

[Modulation of endothelin-1 on pulmonary surfactant synthesis in lung explants]

The effect of endothelin-1(ET-1) on pulmonary surfactant(PS) synthesis was studied in cultured lung explants without serum. The results showed that: 1. ET-1 increased [3H] choline incorporation with dose-dependence and time-dependence. 10(-10) mol.L-1 ET-1 increased the contents of total phospholipids, phosphatidylcholine and phosphatidylglcerol in lung tissues. The major membrane characteristic phospholipids, such as phosphatidylethanolamine, phosphatidylinostitol, phosphatidylserine and sphingomyelin, did not show changes. 2. BQ123, a ETA receptor selective antagonist, could decline the [3H] choline incorporation induced by ET-1(10(-12) and 10(-10) mol.L-1) (P < 0.01). 3. PMA, a protein kinase C(PKC) activator, increased [3H] choline incorporation into lung tissues (P < 0.01); the PKC inhibitor H7 decreased [3H] choline incorporation induced by ET-1(P < 0.01). The results demonstrated that ET-1 at physiological level can enhance the PS synthesis mediated by ETA receptor and PKC.

[Effect of calcium on adherence of Streptococcus mutans MT6R(serotype c) surface protein P1]

OBJECTIVE

To study effects of calcium on the adherence of Streptococcus mutans MT6R(serotype c) surface protein P1 to saliva-coated hydroxyapatite(S-HA).

METHODS

The surface protein P1 of Streptococcus mutans MT6R was purified by PAGE and labeled with 131I(131I-P1). The adherence amount of 131I-P1 to S-HA in different calcium concentration liquid was measured.

RESULTS

The amount of 131I-P1 adherence to S-HA in 0, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0 mmol/L, and calcium was 7175 + 183, 7516 + 192, 8850 + 215, 9335 + 204, 10087 + 228, 10179 + 224 and 10200 + 317 cpm, respectively(P < 0.01). The calcium concentration from 0 to 1.0 mmol/L, the amount of 131I-P1 adherence was increased statistically(P < 0.05), calcium concentration from 1.0 mmol/L to 2.0 mmol/L, the amount of 131I-P1 adherence was increased unstatistically(P > 0.05).

CONCLUSION

Calcium promoted the adherence of surface protein P1 to the S-HA. This result suggested that calcium was involved in the adherence of Streptococcus mutans MT6R (serotype c) surface protein P1.

[Result of orthokeratology for treatment of young people with myopia]

PURPOSE

To evaluate the effectiveness of orthokeratology (Ortho-K) for treatment of myopia in youngths.

METHODS

110 eyes of 56 young peoples with myopia received Ortho-K were studied. The patients were divided into 3 groups according to preoperative diopters. No. I: -1.00(-)-3.00 D, No. II: -3.25(-)-6.00 D, NO. III: -6.25(-)-7.50 D. The uncorrected visual acuities, residual diopters and corneal refractive powers at various time of three months after the operation were statistically analyzed and compared with that of preoperation. Correlation analysis and linear regression analysis were performed between the corneal refractive reduction (X) and clinical refractive reduction (Y) after 3 months of the operation.

RESULTS

In 110 eyes, the uncorrected visual acuities in the first day, first week, first month, second month and third month after operation were significantly improved than that of the preoperation (P < 0.01). The mean residual diopters were significantly reduced than that of preoperation (P < 0.01). The mean refractive powers of cornea were significantly decreased than that of the preoperative (P < 0.01). There was significant correlation between the corneal refractive reduction and clinical refractive reduction. (r = 0.3181, P < 0.001).

CONCLUSION

Orthokeratology is a safe and effective therapeutic method for treatment of myopia in youngths. The long term effect of Orthokeratology need further observation.

Anergic T cells generated in vitro suppress rejection response to islet allografts

BACKGROUND

Induction of antigen-specific unresponsiveness to grafts is the ultimate goal for organ transplantation. It has been shown that anergic T cells generated in vivo can be transferred as suppressor cells. Anergic cells generated in vitro have never been successfully used to prevent allograft rejection in vivo. We examined whether anergic cells generated in vitro by blocking CD28/B7 costimulatory pathway can suppress allograft rejection in vivo.

METHODS

Anergic T cells were generated in vitro by the addition of anti-B7-1 and anti-B7-2 monoclonal antibodies (mAbs) to primary mixed lymphocyte reaction (MLR) consisting of C57BL/6 (B6) splenocytes as responder and irradiated BALB/c splenocytes as stimulator. We tested the ability of these cells to respond to various stimuli and to suppress alloreactive T-cell responses in vitro. For in vivo studies, 4x10(7) anergic cells were injected intravenously immediately after transplantation of BALB/c islets under the renal subcapsular space of streptozotocin-induced diabetic and 2.5-Gy X-irradiated B6 mice.

RESULTS

Anergic cells treated with both mAbs in the primary MLR did not proliferate in secondary MLR against BALB/c and third-party C3H/He stimulators. The cells also failed to respond to immobilized anti-CD3 mAb, although they proliferated in response to concanavalin A or phorbol myristate acetate + ionomycin. The anergic state was reversed by the addition of exogenous IL-2. Furthermore, these cells suppressed the proliferation of naive B6 T cells against either the same (BALB/c) or third-party (C3H/He) stimulator cells. In in vivo studies, irradiated B6 mice rejected BALB/c islet allografts acutely with a mean survival time of 27.0+/-8.3 days, whereas two of six animals injected with the anergic cells accepted the allografts indefinitely (>100 days) with a mean survival time of 52.0+/-38.2 days.

CONCLUSIONS

Anergic cells generated in vitro by blocking CD28/B7 costimulatory pathway suppress islet allograft rejection after adoptive transfer. This procedure might be clinically useful for promoting allograft survival.

A novel peptide antagonist of CXCR4 derived from the N-terminus of viral chemokine vMIP-II

The viral macrophage inflammatory protein-II (vMIP-II) encoded by Kaposi's sarcoma-associated herpesvirus is unique among all known chemokines in that vMIP-II shows a broad-spectrum interaction with both CC and CXC chemokine receptors including CCR5 and CXCR4, two principal coreceptors for the cell entry of human immunodeficiency virus type 1 (HIV-1). To elucidate the mechanism of the promiscuous receptor interaction of vMIP-II, synthetic peptides derived from the N-terminus of vMIP-II were studied. In contrast to the full-length protein that recognizes both CXCR4 and CCR5, a peptide corresponding to residues 1-21 of vMIP-II (LGASWHRPDKCCLGYQKRPLP) was shown to strongly bind CXCR4, but not CCR5. The IC(50) of this peptide in competing with CXCR4 binding of (125)I-SDF-1alpha is 190 nM as compared to the IC(50) of 14.8 nM of native vMIP-II in the same assay. The peptide selectively prevented CXCR4 signal transduction and coreceptor function in mediating the entry of T- and dual-tropic HIV-1 isolates, but not those of CCR5. Further analysis of truncated peptide analogues revealed the importance of the first five residues for the activity with CXCR4. These results suggest that the N-terminus of vMIP-II is essential for its function via CXCR4. In addition, they reveal a possible mechanism for the distinctive interactions of vMIP-II with different chemokine receptors, a notion that may be further exploited to dissect the structural basis of its promiscuous biological function. Finally, the potent CXCR4 peptide antagonist shown here could serve as a lead for the development of new therapeutic agents for HIV infection and other immune system diseases.

A short daytime nap modulates levels of emotions objectively evaluated by the emotion spectrum analysis method

A novel objective technique, the emotion spectrum analysis method, was first applied to investigate emotional fluctuations before, during and after a daytime nap in eight healthy young adults (four males and four females). The subjects were allowed to freely nap between 13.00 and 14.00 h, in which stages 1 and 2 non-rapid eye movement sleep occurred on average for 5.9 and 20.8 min, respectively. Emotional components such as anger, joy, relaxation and sadness were numerically estimated on the basis of spatio-temporal behavior of 21-channel electroencephalogram and analyzed statistically. In comparison with the prenap waking level, the magnitudes of the anger, joy and relaxation components remained stably unchanged during the nap but elevated significantly during the postnap waking period. The sadness component exhibited little significant change throughout the observation period. From the results, we suggest that a short daytime nap modulates the emotions to improve the postnap mental states.

[Preliminary study of clinical scoring on prognosis of severe head-injury]

In this article, 68 cases of severly head-injured patients scoring and prognosis evaluation were reviewed. We have come to a practicable severe head injury index (SHII) for first aid: the blood pressure (Bp), pulse rate (P), respiration rate (R), degree of consciousness and reaction of the pupils are five items taken for estimation of the patients. The highest total score was 25, the lowest was 5. If the score was lasted for 2-4 hours below 7, and first aid non-responsive in 4-6 hours, the mortality and morbidity rates will be high. When the score is more than 14, the first aid salvage will be meaningful. The first aid salvage will be meaningful. The first aid had significant measing especially for those patients whose score was over 18. The detailed method of clinical scoring is shown on chart 2.

Transduction of human IL-9 receptor cDNA into TF1 cells induces IL-9 dependency and erythroid differentiation

Human growth factor-dependent cell line TF1, which lacks interleukin (IL)-9 receptors (R) and does not grow in IL-9, was transduced with a retroviral vector containing human IL-9R cDNA and a selection marker. An IL-9-dependent TF1 cell line, which could also grow in other cytokines, was established after selection in G418 and could produce mature RBC in response to cytokine stimulation. TF1 cells transduced with the same viral vector without the IL-9R insert cDNA (mock control) and then selected responded the same as nontransduced TF1 cells. They failed to grow in response to IL-9 and did not generate RBC. An increased number and size of burst-forming units-erythroid (BFU-E)-like colonies were detected from IL-9R-transduced TF1 cells, compared with mock-transduced cells, in response to erythropoietin (EPO) and IL-9. To evaluate self-renewal and differentiation capacity, colony-replating assays were performed in the presence of IL-3, GM-CSF, IL-9, and EPO. After four replatings, the cloning efficiency of IL-9R-transduced TF1 cells decreased from 98% to 38%, most likely due to terminal erythroid cell differentiation. In contrast, no change in replating efficiency was detected in mock-transduced cells. TF1 cells stably expressing IL-9R and responding to IL-9 can serve as a cell line model to study the intracellular signals mediating IL-9-induced erythroid cell proliferation and differentiation.

[Clinical pathology of Dubin-Johnson syndrome]

OBJECTIVE

To investigate the property of pigment granules in the hepatocytes in patients with Dubin-Johnson syndrome.

METHOD

Light microscopy, histochemical, immnohistochemical and electron microscopy techniques were used to study the pigment glanules and the expression of S-100 protein and HMB45 in hepatocytes.

RESULTS

Histological examination revealed normal lobular architecture and the abundont brown pigments which were chiefly seen in the centrilobular zone hepatocytes. The pigment granules were evidenced to have the characterization of both lipofuscin and melanin by histochemical staining and ultrastructural studies and to have the featurts of the melanin by immnohistochemical staining.

CONCLUSION

The results suggest that the pigment graunles are lipfuscin-melanin complex in the hepatocytes in patients with Dubin-Johnson syndrome.

Structure-based discovery of small molecule inhibitors targeted to protein tyrosine phosphatase 1B

Protein tyrosine phosphatases (PTPases) are involved in the control of tyrosine phosphorylation levels in the cell and are believed to be crucial for the regulation of a multitude of cellular functions. A detailed understanding of the role played by PTPases in various signaling pathways has not yet been achieved, and potent and selective PTPase inhibitors are essential in the quest to determine the functionality of individual PTPases. Using the DOCK methodology, we have carried out a structure-based, computer-assisted search of an available chemical database in order to identify low molecular weight, nonpeptidic PTP1B inhibitors. We have identified several organic molecules that not only possess inhibitory activity against PTP1B but which also display significant selectivity for PTP1B. This indicates that although structural features important for pTyr recognition are conserved among different PTPases, it is possible to generate selective inhibitors targeted primarily to the catalytic site. Kinetic analysis and molecular modeling experiments suggest that the PTP1B active site possesses significant plasticity such that substituted and extended aromatic systems can be accommodated. The newly identified molecules provide a molecular framework upon which therapeutically useful compounds can ultimately be based, and systematic optimization of these lead compounds is likely to further enhance their potency and selectivity.

Analysis of adenoviral transport mechanisms in the vessel wall and optimization of gene transfer using local delivery catheters

Local delivery devices have been used for adenovirus-mediated gene transfer to the arterial wall for the potential treatment of vascular proliferative diseases. However, low levels of adenoviral gene expression in vascular smooth muscle cells may pose a serious limitation to the success of these procedures in the clinic. In this study, we examined the mechanisms controlling adenoviral transport to the vessel wall, using both hydrogel-coated and infusion-based local delivery catheters, with the goal of enhancing in vivo gene transfer under clinically relevant delivery conditions. The following delivery parameters were tested in vivo: applied transmural pressure, viral solution volume and concentration, and delivery time. We found that viral particles are transported into the vessel wall in a manner consistent with diffusion rather than pressure-driven convection. Consistent with diffusion, viral concentration was shown to be the key variable for viral transport in the vessel wall and thus gene expression in vascular smooth muscle cells. A transduction level of 17.8+/-3.2% was achieved by delivering a low volume of concentrated adenoviral beta-galactosidase solution through an infusion balloon catheter at low pressure without an adverse effect on medial cellularity. Under these conditions, effective gene transfer was accomplished within a clinically relevant time frame of 2 min, indicating that longer delivery times may not be necessary to achieve efficient gene transfer.

Glass needle-mediated microinjection of macromolecules and transgenes into primary human blood stem/progenitor cells

A novel glass needle-mediated microinjection method for delivery of macromolecules, including proteins and larger transgene DNAs, into the nuclei of blood stem/progenitor cells was developed. Temporary immobilization of cells to extracellular matrix-coated dishes has enabled rapid and consistent injection of macromolecules into nuclei of CD34(+), CD34(+)/CD38(-), and CD34(+)/CD38(-)/Thy-1(lo) human cord blood cells. Immobilization and detachment protocols were identified, which had no adverse effect on cell survival, progenitor cell function (colony forming ability), or stem cell function (NOD/SCID reconstituting ability). Delivery of fluorescent dextrans to stem/progenitor cells was achieved with 52% +/- 8.4% of CD34(+) cells and 42% +/- 14% of CD34(+)/CD38(-)cells still fluorescent 48 hours after injection. Single-cell transfer and culture of injected cells has demonstrated long-term survival and proliferation of CD34(+) and CD34(+)/CD38(-) cells, and retention of the ability of CD34(+)/CD38(-) cells to generate progenitor cells. Delivery of DNA constructs (currently </= 19.6 kb) and fluorescently labeled proteins into CD34(+) and CD34(+)/CD38(-) cells was achieved with transient expression of green fluorescent protein observed in up to 75% of injected cells. These data indicate that glass needle-mediated delivery of macromolecules into primitive hematopoietic cells is a valuable method for studies of stem cell biology and a promising method for human blood stem cell gene therapy. (Blood. 2000;95:437-444)

Molecular modeling and site-directed mutagenesis of CCR5 reveal residues critical for chemokine binding and signal transduction

The CC chemokine receptor CCR5 is the receptor for several chemokines and coreceptor for the entry of HIV-1. Whereas many studies focus on CCR5 interaction with HIV-1, residues in CCR5 important for chemokine binding and subsequent signal transduction remain poorly understood. Here we use an approach combining protein structure modeling and site-directed mutagenesis to probe the structure of CCR5 and its interactions with chemokine ligands and HIV-1. Structural models of CCR5 rationalize extensive biological data about the role of CCR5 in HIV-1 envelope glycoprotein gp120 binding and HIV-1 entry. Furthermore, we carry out site-directed mutagenesis guided by structural analysis of the complex of CCR5 and a chemokine. This leads to the novel observation that certain residues, such as Tyr10 and Lys26, in the N terminus of CCR5 play a critical structural role for ligand binding and signaling. Single glycine substitution of these residues significantly decreases chemokine binding and signal transduction. These results provide new insight into the structural basis for CCR5 receptor-ligand interaction and may guide the design of novel inhibitors.

[Changes of PMN apoptosis in rabbits after burn]

OBJECTIVES

To study the dynamic changes of apoptosis of PMN from rabbits in the early stage after severe burn in vivo and investigate the effect of burn serum and wound exudate on PMN apoptosis in vitro.

METHODS

12 rabbits were randomly divided into 2 groups: control group (37 degrees C) and burn group (95 degrees C, 15 sec, III degrees 30% TBSA). Whole blood from the burn group at 0, 4, 8, 12, 24 h postburn was stained with acridine orange/ethidium bromide (AO + EB), and observed under UV microscopy. PMNs were isolated from both groups and cultured for 24 h (37 degrees C, 5% CO(2)) with normal serum (NS), burn serum (BS), and subeschar tissue fluid (STF) respectively. Morphological assessment and quantitation of apoptosis were performed with AO + EB stain and flow cytometric analysis.

RESULTS

The number of apoptotic PMN in vivo decreased in the early stage postburn. In the BS + PMN group and STF + PMN group, the percentage of apoptotic PMN reduced (vs NS + PMN group, P < 0.05) and the specific DNA "ladder" pattern for apoptotic cells was not detected by agarose gel electrophoresis. We observed that both burn serum and STF could similarly suppressed PMN apoptosis while there was no significant difference between NS + normal PMN group and NS + burn PMN group.

CONCLUSIONS

Apoptosis is inhibited in PMN from rabbits postburn in the early stage. Both burn serum and STF from rabbits postburn can inhibit PMN apoptosis in vitro.

The roles of side chain and backbone in protein structure probed with glycine- and sarcosine-rich synthetic leucine zipper peptides

The protein folding problem has long been a formidable challenge. Here we present a synthetic natural motif approach that exploits small preexisting structural models for the dissection of forces important in protein folding. An example for this approach is shown in the modification of a 31-residue leucine zipper peptide with the helix-breaking amino acid glycine and the hydrogen bond-breaking imino acid sarcosine. Circular dichroism and NMR experiments have shown that the glycine-modified leucine zipper peptide adopts a stable helical conformation similar to the native conformation while the sarcosine-modified leucine zipper peptide adopts a random coil conformation. These results provide valuable insight into the current controversy over the relative importance of long-range side chain-side chain interactions versus local backbone interactions in protein structure and suggest that the natural motif strategy may represent a useful model to study protein folding.

Regulation of smooth muscle cell migration and integrin expression by the Gax transcription factor

Homeobox transcription factors specify body plan by regulating differentiation, proliferation, and migration at a cellular level. The homeobox transcription factor Gax is expressed in quiescent vascular smooth muscle cells (VSMCs), and its expression is downregulated by vascular injury or other conditions that lead to VSMC proliferation. Previous investigations demonstrate that Gax may regulate VSMC proliferation by upregulating the cyclin-dependent kinase (cdk) inhibitor p21. Here we examined whether Gax influences VSMC migration, a key feature in the development of stenotic lesions after balloon injury. Transduction of a Gax cDNA inhibited the migratory response of VSMCs toward PDGF-BB, basic fibroblast growth factor, or hepatocyte growth factor/scatter factor. Gax expression also inhibited migration of NIH.3T3 fibroblasts and embryonic fibroblasts lacking p53. Gax was unable to inhibit the migration of fibroblasts lacking p21, but this effect could be restored in these cells by providing exogenous p21 or by overexpressing another cdk inhibitor, p16. Flow cytometric analysis implicated a Gax-mediated downregulation of alpha(v)beta(3) and alpha(v)beta(5) integrin expression in VSMCs as a potential cause for reduced cell motility. Gax specifically downregulated beta(3) and beta(5) in VSMCs in culture and after acute vascular injury in vivo. Repression of integrin expression was also found in NIH 3T3 cells and p53 knockout fibroblasts, but not in p21-knockout fibroblasts, unless these cells express exogenous p21 or p16. These data suggest that cycle progression, integrin expression, and cell migration can be regulated in VSMCs by the homeobox gene product Gax.

[Combined use of rhBMP2/BCB and free periosteum in repairing segmental defects in radii of rabbits]

OBJECTIVE

To study the efficacy of combined use of rhBMP2/BCBand free periosteal graft in repairing segmental bony defects.

METHODS

A new grafting material (rhBMP2/BCB) was made by combining recombinant human BMP2 (rhBMP2) and an antigen-free bovine cancellous bone (BCB) as a carrier. rhBMP2/BCB was used alone in conjunction with free periosteal graft to repair a 1.5 cm defect in the radius of the rabbit. The defect-repairing capability for each of the treatment modalities was assessed radiographically, biomechanically, and by densitometry and histological studies.

RESULTS

rhBMP2/BCB used alone was capable of healing the defect in large by 16 weeks, with a similar repair process and mechanism seen with RBX. Combined use of rhBMP2/BCB and free periosteal graft was superior in terms of increased amount and quality of the new bone formed at the early stage of the repair process (within 12 weeks) to rhBMP2/BCB used in isolation, with the defect basically healed by 12 weeks.

CONCLUSIONS

Both methods are effective in repairing segmental bony defects, with rhBMP2/BCB used in conjunction with free periosteal graft being most preferred, considering the satisfactory osteogenesis, osteoconduction and osteoinduction.

A neural network approach to the biopsy diagnosis of early acute renal transplant rejection

AIMS

To develop and test a neural network to assist in the histological diagnosis of early acute renal allograft rejection.

METHODS AND RESULTS

We used three sets of biopsies to train and test the network: 100 'routine' biopsies from Leicester; 21 selected difficult biopsies which had already been evaluated by most of the renal transplant pathologists in the UK, in a study of the Banff classification of allograft pathology and 25 cases which had been classified as 'borderline' according to the Banff classification in a review of transplant biopsies from Oxford. The correct diagnosis for each biopsy was defined by careful retrospective clinical review. Biopsies where this review did not provide a clear diagnosis were excluded. Each biopsy was graded for 12 histological features and the data was entered into a simple single layer perception network, designed using the MATLAB neural network toolbox. Results were compared with logistic regression using the same data, and with 'conventional' histological diagnosis. If the network was trained only with the 100 'routine' cases, its performance with either of the other sets was poor. However, if either of the 'difficult' sets was added to the training group, testing with the other 'difficult' group improved dramatically; 19 of the 21 'Banff' study cases were diagnosed correctly. This was achieved using observations made by a trainee pathologist. The result is better than was achieved by any of the many experienced pathologists who had previously seen these biopsies (maximum 18/21 correct), and is considerably better than that achieved by using logistic regression with the same data.

CONCLUSION

A neural network can provide a considerable improvement in the diagnosis of early acute allograft rejection, though further development work will be needed before this becomes a routine diagnostic tool. The selection of cases used to train the network is crucial to the quality of its performance. There is scope to improve the system further by incorporating clinical information. Other related areas where this approach is likely to be of value are discussed.

Attachment of C-terminus of SDF-1 enhances the biological activity of its N-terminal peptide

The N-terminus of stromal cell-derived factor 1 (SDF-1) is known to be a critical site for CXCR4 receptor binding and signaling. However, the functional role of other regions, in particular the C-terminal helix of SDF-1, has yet to be defined. In this study, we designed and synthesized a peptide model of SDF-1 containing its N- and C-terminal regions. The attachment of the C-terminus of SDF-1, which by itself had no activity in receptor binding and signaling, dramatically increased the effect of the N-terminal fragment in inducing chemotaxis and intracellular Ca(2+) influx in sup T1 cells compared with the peptide containing only the N-terminal sequence. The enhancement in activity was not due to the increase in receptor affinity as the N,C-terminal peptide did not show higher CXCR4 binding than the N-terminal peptide. On the other hand, the intracellular Ca(2+) influx activated by the N,C-terminal peptide, but not the N-terminal peptide, was completely abolished by the addition of heparin, suggesting that the C-terminal fragment of the peptide binds glycosaminoglycans (GAGs) and exerts an effect to modulate biological activity. These data raise the possibility that the C-terminus in native SDF-1 is one of interaction sites with GAGs and may be associated with biological function of SDF-1. Furthermore, this study demonstrates an approach for the design of novel agonists or antagonists of other chemokine receptors that possess enhanced biological activity.

The role of positively charged residues in CXCR4 recognition probed with synthetic peptides

A high positive charge is the common characteristic shared by the beta-sheet region of stromal cell-derived factor-1 (SDF-1) and CXCR4 antagonists such as ALX40-4C consisting of nine D-arginines. This raises the question that the positively charged residues may play a role in recognition of CXCR4. To test this hypothesis, two studies were carried out using synthetic peptides. In the first study, peptide analogs possessing amino acid sequences from both the N-terminus and the beta-sheet region of SDF-1 were used as models to study the functional role of the beta-sheet region of SDF-1. The attachment of positively charged residues to the N-terminal peptide sequence of SDF-1 was found to enhance the ability of the peptides in CXCR4 binding and inhibiting CXCR4-mediated T-tropic HIV-1 entry. In the second study, two peptides containing nine arginines and the N-terminal signal sequence of SDF-1 were used as models to study the receptor binding mechanism of CXCR4 antagonists of high positive charges such as ALX40-4C. One peptide did not show signaling activity as indicated by the lack of calcium influx while another peptide induced unusual calcium influx distinct from that induced by the SDF-1 N-terminal peptide. In addition, the signal induced by the SDF-1 N-terminal peptide was inhibited by ALX40-4C. Therefore, the first study provides experimental support for the role of the highly positive beta-sheet region of SDF-1 in CXCR4 binding. The second study suggests that the binding site of ALX40-4C in CXCR4 may partially overlap with that of the SDF-1 N-terminal peptide. Both findings should be valuable for the design of SDF-1 agonists and antagonists.

Amino acid substitutions within the leucine zipper domain of the murine coronavirus spike protein cause defects in oligomerization and the ability to induce cell-to-cell fusion

The murine coronavirus spike (S) protein contains a leucine zipper domain which is highly conserved among coronaviruses. To assess the role of this leucine zipper domain in S-induced cell-to-cell fusion, the six heptadic leucine and isoleucine residues were replaced with alanine by site-directed mutagenesis. The mutant S proteins were analyzed for cell-to-cell membrane fusion activity as well as for progress through the glycoprotein maturation process, including intracellular glycosylation, oligomerization, and cell surface expression. Single-alanine-substitution mutations had minimal, if any, effects on S-induced cell-to-cell fusion. Significant reduction in fusion activity was observed, however, when two of the four middle heptadic leucine or isoleucine residues were replaced with alanine. Double alanine substitutions that involved either of the two end heptadic leucine residues did not significantly affect fusion. All double-substitution mutant S proteins displayed levels of endoglycosidase H resistance and cell surface expression similar to those of the wild-type S. However, fusion-defective double-alanine-substitution mutants exhibited defects in S oligomerization. These results indicate that the leucine zipper domain plays a role in S-induced cell-to-cell fusion and that the ability of S to induce fusion may be dependent on the oligomeric structure of S.

AP180 and AP-2 interact directly in a complex that cooperatively assembles clathrin

Clathrin-coated vesicles are involved in protein and lipid trafficking between intracellular compartments in eukaryotic cells. AP-2 and AP180 are the resident coat proteins of clathrin-coated vesicles in nerve terminals, and interactions between these proteins could be important in vesicle dynamics. AP180 and AP-2 each assemble clathrin efficiently under acidic conditions, but neither protein will assemble clathrin efficiently at physiological pH. We find that there is a direct, clathrin-independent interaction between AP180 and AP-2 and that the AP180-AP-2 complex is more efficient at assembling clathrin under physiological conditions than is either protein alone. AP180 is phosphorylated in vivo, and in crude vesicle extracts its phosphorylation is enhanced by stimulation of casein kinase II, which is known to be present in coated vesicles. We find that recombinant AP180 is a substrate for casein kinase II in vitro and that its phosphorylation weakens both the binding of AP-2 by AP180 and the cooperative clathrin assembly activity of these proteins. We have localized the binding site for AP-2 to amino acids 623-680 of AP180. The AP180/AP-2 interaction can be disrupted by a recombinant AP180 fragment containing the AP-2 binding site, and this fragment also disrupts the cooperative clathrin assembly activity of the AP180-AP-2 complex. These results indicate that AP180 and AP-2 interact directly to form a complex that assembles clathrin more efficiently than either protein alone. Phosphorylation of AP180, by modulating the affinity of AP180 for AP-2, may contribute to the regulation of clathrin assembly in vivo.

[Enhancing effect of Chinese herbal medicine mixture on peripheral blood lymphocyte proliferation and interleukin-2 production in patients of burn]

OBJECTIVE

To study the regulatory effect of Chinese herbal medicine mixture (CHMM) on cell-mediated immune function in patients of burn.

METHODS

Patients of burn were treated with CHMM and the therapeutic effect was evaluated by their peripheral blood T-lymphocyte (PBL) proliferation and interleukin-2 (IL-2) production determination.

RESULTS

The PBL proliferation began to increase after 5 days of medication and the response was significant between the 10th to 20th day, which was in accordance with the change of IL-2 production.

CONCLUSION

CHMM has immune regulatory effect on cell-mediated immune function in patients of burn.

[The design of a reflection sensor of NIRS tissue oximetry]

A design of the reflection light-electric Sensor suited to monitoring the statues of tissue blood oxygen on the surface of body is described. The designed sensors have been used too to detect blood oxygen statues of brain and muscle respectively, and many useful informations have been acquired Therefore The above-mentioned design is reasonalle and Feasikle.

Adenovirus-mediated delivery of the Gax transcription factor to rat carotid arteries inhibits smooth muscle proliferation and induces apoptosis

Adenovirus-mediated gene delivery in animal models of vascular injury has provided insights into the mechanisms underlying vessel wall pathologies. We have previously demonstrated that overexpression of the Gax transcription factor inhibits neointimal formation in rat and rabbit models of arterial injury. Here, we evaluate potential mechanisms for the reduction in stenotic lesion size due to Gax overexpression. At 3, 7 and 14 days after injury the Ad-Gax-infected arteries displayed a marked decrease in medial vascular smooth muscle cell number (3 days, 54% reduction P < 0.01; 7 days, 41% reduction P < 0.003; 14 days, 49% reduction P < 0.02). At 3 days after injury, PCNA expression was attenuated in the Ad-Gax-treated vessels compared with control vessels (65% reduction P < 0.02), indicating a reduction in cellular proliferation. At 7 days and 14 days after injury Ad-Gax-infected arteries exhibited elevated number of TUNEL-positive medial VSMCs compared with control-treated arteries (7 days, 9.2-fold increase P < 0.03; 14 days, 17.2-fold increase P < 0.03), indicating an induction of apoptotic cell death. These data suggest that deregulated Gax expression induces first cell cycle arrest and then apoptosis in the vascular smooth muscle cells that contribute to the neointimal layer. Therefore, the efficacy of this therapeutic strategy appears to result from the ability of the Gax transcriptional regulator to modulate multiple cellular responses.

Adenovirus-mediated delivery of fas ligand inhibits intimal hyperplasia after balloon injury in immunologically primed animals

BACKGROUND

Adenoviral constructs have been used for studies of injury-induced vascular hyperplasia in immunologically naive laboratory animals, but their usefulness for intra-arterial gene therapy may be limited by the prevalence of preexisting immunity to adenovirus in the patient population. Here, we explored the efficacy of adenovirus-mediated transfer of Fas ligand, a cytotoxic gene with immunomodulatory properties, in inhibiting injury-induced vascular lesion formation in both naive and immunologically primed animals.

METHODS AND RESULTS

Lesion formation was evaluated in balloon-injured carotid arteries of naive and adenovirus-immunized rats that were infected with adenoviral constructs expressing Fas ligand (Ad-FasL), the cyclin-dependent kinase inhibitor p21 (Ad-p21), or beta-galactosidase (Ad-betagal). In naive rats, Ad-FasL induced apoptosis in medial vascular smooth muscle cells and inhibited intimal hyperplasia by 60% relative to Ad-betagal-treated vessels (P<0.05), whereas the cytostatic agent Ad-p21 decreased lesion size by 58% (P<0.05). In animals preimmunized with an adenoviral vector containing no transgene, Ad-FasL significantly inhibited neointima formation (73% reduction, P<0.05), but Ad-p21 failed to inhibit neointima formation relative to controls. Immunologically primed rats displayed robust T-cell infiltration in Ad-p21- and Ad-betagal-treated vessels, but T-cell infiltration was markedly attenuated in Ad-FasL-treated vessels.

CONCLUSIONS

Our data demonstrate that adenovirus-mediated Fas ligand delivery can inhibit intimal hyperplasia in both immunologically primed and naive animals, whereas the efficacy of an adenovirus-mediated p21 delivery is limited to immunologically naive animals. This study documents, for the first time, the therapeutic efficacy of intravascular adenoviral gene transfer in animals with preexisting immunity to adenovirus.

Viral myocarditis: identification of five differentially expressed genes in coxsackievirus B3-infected mouse heart

Differences in host susceptibility to viral myocarditis caused by a given strain of coxsackievirus B3 (CVB3) are known to be largely related to host genetic factors. Little is known, however, about the key genes that encode determinants (mediators) of myocarditis development or the nature of injury. To identify these genes and further understand the molecular mechanisms of the disease process, we have used a murine model and the differential display technique to fingerprint mRNAs from CVB3-infected mouse hearts. Total RNA was extracted from hearts of 4- and 10-week-old A/J(H-2(a)) mice at day 4 after CVB3 infection, and mRNAs were detected by reverse transcriptase-polymerase chain reaction and subsequently analyzed on polyacrylamide DNA sequencing gels. The differentially displayed bands were confirmed by Northern hybridization using the bands as cDNA probes. Twenty-eight upregulated or downregulated bands were selected from the sequencing gels; among these, 2 upregulated and 3 downregulated cDNA fragments were confirmed by Northern hybridization. DNA sequence analysis and GenBank searching have determined that 4 of the 5 candidate genes are homologous to genes encoding Mus musculus inducible GTPase, mouse mitochondrial hydrophobic peptide (a subunit of NADH dehydrogenase), mouse beta-globin, and Homo sapiens cAMP-regulated response element binding protein (CREB) binding protein (CBP), respectively. The remaining candidate gene matches an unpublished cDNA clone, M musculus Nip21 mRNA (GenBank accession number, AF035207), which is homologous to human Nip2, a Bcl-2 binding protein. Our data suggest preliminarily that both structural and nonstructural genes are involved in myocarditis development. For the structural gene, beta-globin, we further confirmed its downregulation at the protein level by measuring the mean cell volume of red blood cells and found it was marginally reduced in the CVB3-infected group (P<0.06), with no change in hemoglobin concentration. Cardiac myoglobin concentration was also measured and found to be decreased (P<0.005), with a parallel decrease in total soluble protein in the CVB3-infected mouse myocardium (P<0.01). We also noted that the ratio of myoglobin to total protein was not significantly changed; this may be due to the downregulation of additional genes in the host heart, a number being observed on the differential display gels. The significant downregulation of beta-globin major gene expression in the heart may be relevant to impaired cardiac function in both the early and late postinfection period. The other identified nonstructural genes are known to be involved in regulation of gene expression, signal transduction pathways, and apoptotic cell death. The altered expression of structural and nonstructural genes may play important roles in the mediation of myocarditis development and perhaps other pathological processes in the heart.

Reversal of GATA-6 downregulation promotes smooth muscle differentiation and inhibits intimal hyperplasia in balloon-injured rat carotid artery

The GATA-6 transcription factor is expressed in quiescent vascular smooth muscle cells (VSMCs) in culture, and levels of its transcript are rapidly downregulated on mitogen stimulation. In this study, we demonstrate that the GATA-6 transcript, protein, and DNA-binding activity are downregulated in rat carotid arteries on balloon injury. Downregulation was detected at 1 and 3 days after injury and recovered by 7 days. To assess the role of GATA-6 downregulation in injury-induced vascular lesion formation, adenoviral vectors were used to express wild-type human GATA-6 cDNA (Ad-GATA6) or an inactive mutant cDNA that lacks a portion of the zinc-finger domain (Ad-GATA6DeltaZF). Adenovirus-mediated GATA-6 gene transfer to the vessel wall after balloon injury partially restored the levels of GATA-6 protein and DNA-binding activity to before injury levels. The local delivery of Ad-GATA6 but not Ad-GATA6DeltaZF inhibited lesion formation by 46% relative to saline control and 50% relative to a control adenovirus that expressed lacZ. Local delivery of Ad-GATA6 also reversed changes in the expression patterns of smooth muscle myosin heavy chain, smooth muscle alpha-actin, calponin, vinculin, metavinculin, and proliferating cell nuclear antigen that are associated with injury-induced VSMC phenotypic modulation. These data indicate that the injury-induced downregulation of GATA-6 is an essential feature of VSMC phenotypic modulation that contributes to vessel lesion formation.

A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton

Here we describe a new triconodont mammal from the Late Jurassic/Early Cretaceous period of Liaoning, China. This new mammal is represented by the best-preserved skeleton known so far for triconodonts which form one of the earliest Mesozoic mammalian groups with high diversity. The postcranial skeleton of this new triconodont shows a mosaic of characters, including a primitive pelvic girdle and hindlimb but a very derived pectoral girdle that is closely comparable to those of derived therians. Given the basal position of this taxon in mammalian phylogeny, its derived pectoral girdle indicates that homoplasies (similarities resulting from independent evolution among unrelated lineages) are as common in the postcranial skeleton as they are in the skull and dentition in the evolution of Mesozoic mammals. Limb structures of the new triconodont indicate that it was probably a ground-dwelling animal.

Early cell loss after angioplasty results in a disproportionate decrease in percutaneous gene transfer to the vessel wall

Acute cell loss has been documented following angioplasty of normal rat and rabbit arteries. Here we analyzed the effects of balloon injury intensity on early cellular loss in single- and double-injury models and how it influences the efficiency of percutaneous gene delivery to the vessel wall. Rabbits underwent bilateral iliac angioplasties (n = 52) with 2.5-mm (balloon-to-artery [B/A] ratio, 1.08 to 1.13) and 3.0-mm (B/A ratio, 1.29 to 1.34) balloons. In the single-injury model, the 3.0-mm balloon induced a 61% reduction in medial cellularity at 3 days postinjury (p < 0.001) while the 2.5-mm balloon did not produce significant cell loss. In the double-injury model, the effects were more pronounced, with 35% (p < 0.01) and 91% (p < 0.001) reductions in medial cellularity at 3 days with the 2.5- and 3.0-mm balloons, respectively, but neointimal cellularity was decreased only with the 3.0-mm balloon (37% reduction, p = 0.025). Adenovirus-mediated beta-galactosidase gene delivery with a channel balloon (n = 24) revealed that larger balloon-to-artery ratios decreased both absolute levels and relative frequencies of transgene expression in the vessel wall. In the single-injury model, gene transfer efficiency was 4.2+/-1.1 and 1.3+/-0.25% (p < 0.05) for the small and large balloons, respectively. In the double-injury model, gene transfer efficiency was 6.6+/-1.6 and 2.3+/-0.8% (p < 0.05) in the neointima and 4.1+/-1.2 and 2.6+/-1.2% (p = NS) in the media for the small and large balloon, respectively. We conclude that early cell loss is dependent on the intensity of the injury in both single- and double-injury models of balloon angioplasty, with greater frequencies of cell loss occurring in the media than in the neointima. In both models, larger balloon-to-artery ratios result in disproportionate reductions in percutaneous adenovirus-mediated gene delivery.

Hyperglycemia inhibits insulin activation of Akt/protein kinase B but not phosphatidylinositol 3-kinase in rat skeletal muscle

Sustained hyperglycemia impairs insulin-stimulated glucose utilization in the skeletal muscle of both humans and experimental animals--a phenomenon referred to clinically as glucose toxicity. To study how this occurs, a model was developed in which hyperglycemia produces insulin resistance in vitro. Rat extensor digitorum longus muscles were preincubated for 4 h in Krebs-Henseleit solution containing glucose or glucose + insulin at various concentrations, after which insulin action was studied. Preincubation with 25 mmol/l glucose + insulin (10 mU/ml) led to a 70% decrease in the ability of insulin (10 mU/ml) to stimulate glucose incorporation into glycogen and a 30% decrease in 2-deoxyglucose (2-DG) uptake, compared with muscles incubated with 0 mmol/l glucose. Glucose incorporation into lipid and its oxidation to CO2 were marginally diminished, if at all. The alterations of glycogen synthesis and 2-DG uptake were first evident after 1 h and were maximal after 2 h of preincubation; they were not observed in muscles preincubated with 25 mmol/l glucose + insulin for 5 min. Preincubation for 4 h with 25 mmol/l glucose in the absence of insulin produced a similar although somewhat smaller decrease in insulin-stimulated glycogen synthesis; however, it did not alter 2-DG uptake, glucose oxidation to CO2, or incorporation into lipids. Studies of insulin signaling in the latter muscles revealed that activation of Akt/protein kinase B (PKB) was diminished by 60%, compared with that of muscles preincubated in a glucose-free medium; whereas activation of phosphatidylinositol (PI) 3-kinase, an upstream regulator of Akt/PKB in the insulin-signaling cascade, and of mitogen-activated protein (MAP) kinase, a parallel signal, was unaffected. Immunoblots demonstrated that this was not due to a change in Akt/PKB abundance. The results indicate that hyperglycemia-induced insulin resistance can be studied in rat skeletal muscle in vitro. They suggest that impairment of insulin action in these muscles is related to inhibition of Akt/PKB by events that do not affect PI 3-kinase.