Complement as a mediator of vascular inflammation and activation in allografts.
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Animals↗
Biomedical subjects
Z Qian
Publications and source records attributed to Z Qian.
Newcastle disease virus activates macrophages for anti-tumor activity.
Newcastle Disease Virus (NDV), an agent with interesting immune stimulatory and anti-tumor activity, was investigated for its capacity to activate anti-tumor activity in murine macrophages in vitro and in vivo. Direct macrophage activation was seen under a variety of experimental conditions using two different strains of NDV, different sources of macrophages (spleen and peritoneum) and different strains of mice (DBA/2, C57BL/6, 615). Various macrophage enzymes (ADA, iNOS, lysozyme, acid phosphatase) became upregulated and anti-tumor effector molecules such as nitric oxide (NO) and TNF-alpha were found in the supernatant. NDV activated macrophages performed anti-tumor activity in vitro such as anti-tumor cytostasis and anti-tumor cytotoxicity. The cytotoxic anti-tumor activity was broad and active against all tumor lines tested including mammary carcinoma, lung carcinoma, mastocytoma and immune escape variants (lymphoma). Macrophage activation via BCG/LPS also caused a broad range anti-tumor cytotoxic activity while activation via mixed lymphocyte culture conditioned medium had restricted anti-tumor activity. Anti-tumor activity of NDV activated macrophages could be transfered in vivo. Transfer of macrophages which had not been appropriately activated exerted either no effect or a tumor growth augmenting effect. Repeated intravenous transfer of NDV activated macrophages exerted a significant suppressive effect on pulmonary metastases in a mammary carcinoma tumor model as well as in a lung carcinoma model. Taken together these results demonstrate that NDV can strongly activate macrophages to perform anti-tumor activities in vitro and in vivo.
Animals↗
High-throughput screening for human collagenase 1 inhibitors.
AIM: To establish a high-throughput method for inhibitor screening using a recombinant collagenase catalytic domain. METHODS: Human collagenase 1 catalytic domain protein was expressed in E coli and used for screening a set of 2720 compounds in a high-throughput fashion. RESULTS: The screening was accomplished within 2 h and 10 min with consumption of each compound at 4 micrograms. Sixty-six compounds were identified with > 60% inhibitory activity at 20 mg/L, among which 44 compounds were confirmed by subsequent testing at multiple concentrations. The most potent compound showed an IC50 at 4.3 mumol/L, and there were total 15 compounds with IC50 less than 20 mumol/L. CONCLUSION: The high-throughput method using the recombinant collagenase is fast, effective and practical in identifying inhibitors.
Collagenases↗
[Herbological investigation on traditional Chinese medicine gegen].
In this paper, herbological investigation was carried out into a large of Ben-Cao literature that concerned the origin, clinical use and other relevant aspects of Gegen, from which we can judge that Gegen used in ancient times match to that specified in the present Chinese Pharmacopoeia.
Anti-Inflammatory Agents, Non-Steroidal↗
[Photochemistry study on novel water soluble thioxanthone photoinitiators].
The photochemistry of nine water soluble thioxanthone photoinitiators was examined by UV absorption, fluorescence, phosphorescence and ESR techniques. Maximal absorption, extinction coefficients, fluorescence and phosphorescence quantum yields, ESR intensity were determined. The solvent effects on absorption and fluorescence as well as the relationship between structure and photochemical activities were discussed.
Electron Spin Resonance Spectroscopy↗
Neuronally modulated transcription of a glycine transporter in rat dorsal cochlear nucleus and nucleus of the medial trapezoid body.
Neurotransmitter transporters limit transmitter concentration at the postsynaptic membrane by removing neurotransmitters from the synaptic cleft. Not only do neurotransmitter transporters contribute to the regulation of synaptic transmission, but they themselves might be dynamically regulated by neuronal activity of the neurons in which they are expressed. In this experiment, we investigated the question of whether the transcription of two different glycine transporters, Glyt1 and Glyt2, is influenced by neuronal activity. These transporters are found in the dorsal cochlear nucleus (DCN) and medial nucleus of the trapezoid body. Glyt1 and Glyt2 mRNA were measured by using hybridization histochemistry and a semiquantitative reverse transcription polymerase chain reaction. Decreases in auditory primary afferent activity, caused by either unilateral labyrinthectomy or disruption of the middle ear ossicles, caused a reduction in Glyt2, but not Glyt1 mRNA in the ipsilateral DCN and in the contralateral medial nucleus of the trapezoid body. Acoustic stimulation at either 10 kHz or 40 kHz was used to provide controlled increases in primary afferent activity, evoking localized increases in Glyt2 mRNA in clusters of neurons in the DCN. The location of these clusters corresponded to the regions of the auditory tonotopic map devoted to these frequencies. The duration of changes in Glyt2 mRNA evoked by unilateral labyrinthectomy, measured with the reverse transcription polymerase chain reaction, was 5-10 days. These data provide the first example of in vivo regulation of transporter transcription by neuronal activity.
Amino Acid Transport Systems, Neutral↗
Complement causes allograft injury by cell activation rather than lysis.
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Animals↗
Molecular cloning and characterization of a mitogen-activated protein kinase-associated intracellular chloride channel.
ERK7, a member of the mitogen-activated protein kinase family, has a carboxyl-terminal tail that is required for ERK7 activation, cellular localization, and its ability to inhibit DNA synthesis. To identify proteins that interact with ERK7, we utilized a yeast two-hybrid screen with the COOH-terminal tail of ERK7 as bait and isolated the cDNA for a novel protein termed CLIC3. The interaction between CLIC3 and ERK7 in mammalian cells was confirmed by co-immunoprecipitation. CLIC3 has significant homology to human intracellular chloride channels 1 (NCC27/CLIC1) and 2 and bovine kidney chloride channel p64. Like NCC27/CLIC1, CLIC3 is predominantly localized in the nucleus and stimulates chloride conductance when expressed in cells. Taken together, these results suggest that CLIC3 is a new member of the human CLIC family. The observed interaction between CLIC3 and ERK7 is the first demonstration of a stable complex between a protein that activates chloride ion transport and a member of the mitogen-activated protein kinase family of signal transducers. The specific association of CLIC3 with the COOH-terminal tail of ERK7 suggests that CLIC3 may play a role in the regulation of cell growth.
Amino Acid Sequence↗
Investigation of the mechanism of the bioacoustic effect.
Bacterial biofilms growing on implanted medical devices are difficult to eradicate, even with aggressive antibiotic therapy. However, application of ultrasound enhances the effectiveness of the antibiotic. The possible mechanisms of this phenomenon were explored in light of the observed influence of various ultrasonic parameters on the enhanced action of gentamicin against biofilms of Pseudomonas aeruginosa. It is postulated that ultrasound increases the transport of gentamicin through the cell membranes, which is the proposed rate determining step in killing by gentamicin. It is possible that the ultrasound perturbs the cell membrane and stimulates active uptake or permits passive uptake by temporarily disrupting the membrane or other structural cell components. The cell membrane disruption could be caused by high pressure, high shear stress, or cavitation. The dependence upon peak power density suggests that acoustic pressure plays a significant role. There is also a strong frequency component that causes the killing effect to decrease as frequency increases. A mathematical analysis of oscillatory shear stress on the cell shows that the magnitude of stress increases with frequency; thus, the hypothesis of oscillatory shear inducing antibiotic uptake is discounted. In addition, the shear displacement caused by shear forces is very small, so the shear disruption caused by oscillatory flow in an acoustic field has minimal impact. The experimental data also rule out the existence of transient cavitation in the bioacoustic effect. It is possible that stable cavitation and the accompanying microstreaming contribute to the bioacoustic effect.
Anti-Bacterial Agents↗
C6 produced by macrophages contributes to cardiac allograft rejection.
The terminal components of complement C5b-C9 can cause significant injury to cardiac allografts. Using C6-deficient rats, we have found that the rejection of major histocompatibility (MHC) class I-incompatible PVG.R8 (RT1.A(a)B(u)) cardiac allografts by PVG.1U (RT1.A(u)B(u)) recipients is particularly dependent on C6. This model was selected to determine whether tissue injury results from C6 produced by macrophages, which are a conspicuous component of infiltrates in rejecting transplants. We demonstrated that high levels of C6 mRNA are expressed in isolated populations of macrophages. The relevance of macrophage-produced C6 to cardiac allograft injury was investigated by transplanting hearts from PVG. R8 (C6-) donors to PVG.1U (C6-) rats which had been reconstituted with bone marrow from PVG.1U (C6+) rats as the sole source of C6. Hearts grafted to hosts after C6 reconstitution by bone marrow transplantation underwent rejection characterized by deposition of IgG and complement on the vascular endothelium together with extensive intravascular aggregates of P-selectin-positive platelets. At the time of acute rejection, the cardiac allografts contained extensive perivascular and interstitial macrophage infiltrates. RT-PCR and in situ hybridization demonstrated high levels of C6 mRNA in the macrophage-laden transplants. C6 protein levels were also increased in the circulation during rejection. To determine the relative contribution to cardiac allograft rejection of the low levels of circulating C6 produced systemically by macrophages, C6 containing serum was passively transferred to PVG.1U (C6-) recipients of PVG.R8 (C6-) hearts. This reconstituted the C6 levels to about 3 to 6% of normal values, but failed to induce allograft rejection. In control PVG.1U (C6-) recipients that were reconstituted with bone marrow from PVG.1U (C6-) donors, C6 levels remained undetectable and PVG.R8 cardiac allografts were not rejected. These results indicate that C6 produced by macrophages can cause significant tissue damage.
Animals↗
Animal model of bile duct dilatation created with minimally invasive surgery.
RATIONALE AND OBJECTIVES: The purpose of the study was to evaluate a method of producing obstruction of the common bile duct and concomitant biliary duct dilatation in an animal model. MATERIALS AND METHODS: Laparoscopic placement of a double-balloon occlusion device was used to produce common bile duct obstruction and bile duct dilatation in pigs. RESULTS: One week after the procedure, common bile duct obstruction and dilatation of the biliary tree were demonstrated with either percutaneous transhepatic cholangiography or percutaneous cholecystography. CONCLUSION: The use of this method is technically feasible and provides a useful subacute and chronic animal model of common bile duct obstruction and dilatation of the biliary tree for percutaneous interventional training and research purposes.
Animals↗
Functional interactions between herpesvirus oncoprotein MEQ and cell cycle regulator CDK2.
Marek's disease virus, an avian alphaherpesvirus, has been used as an excellent model to study herpesvirus oncogenesis. One of its potential oncogenes, MEQ, has been demonstrated to transform a rodent fibroblast cell line, Rat-2, in vitro by inducing morphological transformation and anchorage- and serum-independent growth and by protecting cells from apoptosis induced by tumor necrosis factor alpha, C2-ceramide, UV irradiation, or serum deprivation. In this report, we show that there is a cell cycle-dependent colocalization of MEQ protein and cyclin-dependent kinase 2 (CDK2) in coiled bodies and the nucleolar periphery during the G1/S boundary and early S phase. To our knowledge, this is the first demonstration that CDK2 is found to localize to coiled bodies. Such an in vivo association and possibly subsequent phosphorylation may result in the cytoplasmic translocation of MEQ protein. Indeed, MEQ is expressed in both the nucleus and the cytoplasm during the G1/S boundary and early S phase. In addition, we were able to show in vitro phosphorylation of MEQ by CDKs. We have mapped the CDK phosphorylation site of MEQ to be serine 42, a residue in the proximity of the bZIP domain. An indirect-immunofluorescence study of the MEQ S42D mutant, in which the CDK phosphorylation site was mutated to a charged residue, reveals more prominent cytoplasmic localization. This lends further support to the notion that the translocation of MEQ is regulated by phosphorylation. Furthermore, phosphorylation of MEQ by CDKs drastically reduces the DNA binding activity of MEQ, which may in part account for the lack of retention of MEQ oncoprotein in the nucleus. Interestingly, the localization of CDK2 in coiled bodies and the nucleolar periphery is observed only in MEQ-transformed Rat-2 cells, implicating MEQ in modifying the subcellular localization of CDK2. Taken together, our data suggest that there is a novel reciprocal modulation between the herpesvirus oncoprotein MEQ and CDK2.
Animals↗
Intravenous hydroxyethylrutosides combined with long-term oral anticoagulation in atherosclerotic nonreconstructable critical leg ischemia: a retrospective study.
OBJECTIVE: To evaluate in a group of seriously diseased patients with nonreconstructable chronic critical leg ischemia (CLI), treated by a combination of i.v. hydroxyethylrutosides (HR)* and oral anticoagulation (AC) by warfarin, the short-term effects on the cutaneous microvascular blood perfusion of the soles of feet and especially the long-term clinical outcome in terms of amputation and death. DESIGN: A retrospective comparison between two groups of patients, HR + AC and a comparable reference group, fulfilling the same inclusion and exclusion criteria corresponding to the definition of CLI according to the Second European Consensus Document (1991). Clinical follow-up in both groups was made after 1, 3, 6, 12, and 24 months. SETTING: Patients were examined at university departments of clinical physiology with special interest in peripheral vascular disease, in cooperation with colleagues at university departments of surgery, internal medicine and dermatology of Karolinska Hospital, Södersjukhuset and Huddinge Hospital. PATIENTS: A total of seventy patients with CLI according to the definition of the Second European Consensus Document, 1991, ie, besides severe rest pain or ischemic lesions also a toe blood pressure < 30 mg Hg. Group with HR + anticoagulation (AC): 42 patients (19 diabetics, 23 nondiabetics). Reference group: 28 patients (18 diabetics, 10 nondiabetics). For distribution of age and toe blood pressure at baseline, see Table I. INTERVENTIONS: Therapy group: besides ordinary standard therapy, daily HR infusions for a mean period of 3.6 weeks + oral anticoagulation continued to the end of the study at 24 months. A comparable reference group on the same basic therapy but without the combination HR + AC. PARAMETERS IN EVALUATION: Short-term parameters: clinical data, skin temperature, and fluorescein imaging. Long-term outcome: amputation or death. RESULTS: Short-term and long-term results with HR + AC indicated that patients with severe CLI and very poor prognosis benefited in terms of survival and limb salvage from initial therapy with HR infusion combined with long-term oral anticoagulation. Results of this combined treatment seem at least comparable with those with i.v. prostacyclin analogies.
Administration, Oral↗
Recanalization of thrombosed superficial femoral arteries with a hydraulic thrombectomy catheter in a canine model.
OBJECTIVE: This experiment was conducted to evaluate efficacy and safety of the Oasis thrombectomy catheter on arterial thrombosis in dogs. MATERIALS AND METHODS: Thrombosis was induced in 18 femoral arteries of nine mongrel dogs. Recanalization of the thrombosed femoral artery was performed using a thrombectomy catheter 7-10 days after thrombus induction. Pre- and postprocedural arterial status was documented by angiography. After mechanical thrombectomy, the animals were sacrificed and the femoral arteries were harvested and examined macro- and microscopically. Additionally, in vitro fragmentation was carried out to determine particle size and distribution from the recovered effluent. RESULTS: Subacute thrombosis was successfully created in 15 femoral arteries. Full recanalization was achieved in 80% (12/15) of the thrombosed femoral arteries without any residual thrombus. No significant downstream embolization was documented angiographically. Endothelial denudation was observed in all the treated arteries along with occasional disruption of the internal elastic lamina. No medial injury was seen. Ninety-eight percent of thrombus was liquefied, defined as particles smaller than 15 microm, by the catheter. Particles larger than 400 microm represented 0.27% of the original clot weight. CONCLUSION: Occluded femoral arteries with 7- to 10-day-old thrombus can be efficiently recanalized with the Oasis catheter in dogs without any significant complication. This thrombectomy catheter appears to be highly effective and safe and requires no sophisticated equipment. Blood loss was our major concern regarding use of this catheter but can be minimized by strictly controlling activation time and restricting the inflow into the vascular segment being treated.
Animals↗
A simplified arteriovenous malformation model in sheep: feasibility study.
BACKGROUND AND PURPOSE: Recently, a swine model of a cerebral arteriovenous malformation (AVM) has been developed that closely resembles a human AVM of the brain. The creation of such a model requires sophisticated neurointerventional techniques. The purpose of this study was to develop a simple and cost-effective AVM animal model that does not require additional endovascular techniques. METHODS: A surgical anastomosis was created in seven sheep between the common carotid artery and the ipsilateral jugular vein, followed by ligation of the jugular vein above the anastomosis and of the proximal common carotid artery below the anastomosis. The anastomosis was created on the left side in four animals and on the right side in three. Cerebral angiography from the contralateral carotid artery was performed before and immediately after surgery to delineate the relevant cerebral vascular anatomy and to determine the direction of blood flow. RESULTS: An angiographic appearance simulating an AVM was found in all the animals. The ramus anastomoticus and arteria anastomotica functioned as the feeding vessels to the rete mirabile, which represented the nidus in our model, and to the jugular vein, which represented the draining vein from the malformation. Extensive collateral flow through the rete mirabile into the distal segment of the external carotid artery above the ligature was observed angiographically, with retrograde flow through the surgical anastomosis into the jugular vein. CONCLUSION: A simple surgically created experimental model for cerebral AVMs was developed in sheep without the need for additional complex endovascular catheter manipulations of intracranial branches. Such an animal model can substantially reduce the cost of research and training in the neurointerventional or radiosurgical management of AVMs.
Anastomosis, Surgical↗
[Soft extravascular model (SEM) with beta-radioactive ray inhibits smooth muscle cell proliferation and intimal hyperplasia in autogenous vein graft].
OBJECTIVE: To investigate the effects of the soft extravascular model (SEM) with 32P on intimal hyperplasia and smooth muscle cell preliferation in autogenous vein grafts. METHODS: We transplanted the femoral veins to the co-lateral femoral arteries in rabbits. The animals were divided into three groups of Aspirin group, 32P group and control group. We observed the expression density of endothelin type A receptor cDNA (ETAcDNA) and intimal relative thickness by using in situ molecular hybridization of ETAcDNA by computerized image analysis technology. RESULTS: SEM with beta-ray obviously inhibited SMC preliferation from 1 W to 12 W postoperation, and notably restrained intimal hyperplasia at early to middle stage of graft. Aspirin could not inhibit SMC proliferation and intimal hyperplasia under the condition of this experiment.
Animals↗
[The effects of transforming growth factor alpha and beta 1 on the proliferation of alveolar type II cells in vitro].
OBJECTIVE: To investigate the effect of transforming growth factor alpha and beta(1) (TGFalpha and beta(1)) on the proliferation of alveolar type II cells in vitro and the molecular mechanism related. METHODS: (3)H-TdR incorporation and cell counting for the assay of cell growth; dot blot, in situ hybridization, and immunohistochemical methods for analysing the expression of cyclin D1 and cycle-dependent kinase 4 (CDK4) genes. RESULTS: With increasing of the concentration of TGFalpha and beta(1) (0.01 ng-100 ng/ml), TGFalpha enabled to increase (3)H-TdR incorporation and the number of alveolar type II cells, while the effect of TGFbeta(1) was opposite and both effects were dose-dependent (P < 0.01). TGFalpha-treated cells decreased the expression of CDK4 mRNA, and the relevant in comparing with the control (P < 0.01). On the contrary, TGFbeta(1)-treated cells decreased the expression of CDK4 mRNA), CDK4 as well as the cyclin D1 proteins (P < 0.05). CONCLUSION: Both TGFalpha and beta(1) were considered implicated in the regulation of proliferation of cultured alveolar type II cells isolated from the adult rats and CDK4 might be a common target against TGFalpha and beta(1) signals.
Animals↗
[Anti-Toxoplasma effect of activated mouse macrophages induced by interferon-gamma combined with TNF-alpha].
AIM: To compare the inhibitory effect of the macrophages activated by IFN-gamma combined with TNF-alpha against RH strain and Fukaya strain. METHODS: The average parasite proliferation rates of the two strains within the cytokine-activated M phi s were calculated at different times post-challenge, the nitric oxide (NO) levels in the medium supernatant were simultaneously determined. RESULTS: In the macrophages activated by 100 U each of IFN-gamma and TNF-alpha, the invaded tachyzoites of RH strain were completely killed, while the invaded tachyzoites of Fukaya strain remained slow proliferation with significantly lower levels of NO detected at 24 h post challenge. CONCLUSION: The difference in the anti-Toxoplasma effect of the activated macrophages against RH and Fukaya strains might be attributed to the different amount of NO produced by the macrophages.
Animals↗