Synergistic effect of Tripterygium wilfordii Hook.F (TWHF) and cyclosporin A in rat liver transplantation.
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Animals↗
Biomedical subjects
X He
Publications and source records attributed to X He.
Identification of actin binding protein, ABP-280, as a binding partner of human Lnk adaptor protein.
Human Lnk (hLnk) is an adaptor protein with multiple functional domains that regulates T cell activation signaling. In order to identify cellular Lnk binding partners, a yeast two-hybrid screening of human spleen cDNA library was carried out using human hLnk as bait. A polypeptide sequence identical to the C-terminal segment of the actin binding protein (ABP-280) was identified as a hLnk binding protein. The expressed hLnk and the FLAG tagged C-terminal 673 amino acid residues of ABP-280 or the endogenous ABP-280 in COS-7 cells could be co-immunoprecipitated using antibodies either to hLnk, FLAG or ABP-280, respectively. Furthermore, immunofluorescence confocal microscope showed that hLnk and ABP-280 co-localized at the plasma membrane and at juxtanuclear region of COS-7 cells. In Jurkat cells, the endogenous hLnk also associates with the endogenous ABP-280 indicating that the association of these two proteins is physiological. The interacting domains of both proteins were mapped using yeast two-hybrid assays. Our results indicate that hLnk binds to the residues 2006-2454 (repeats 19-23C) of ABP-280. The domain in hLnk that associates with ABP-280 was mapped to an interdomain region of 56 amino acids between pleckstrin homology and Src homology 2 domains. These results suggest that hLnk may exert its regulatory role through its association with ABP-280.
Actins↗
Increased expression of apoptosis-linked gene 2 (ALG2) in the rat brain after temporary focal cerebral ischemia.
Calcium is an important mediator of programmed cell death induced by transient cerebral ischemia, and calcium-binding proteins have been implicated in calcium-regulated signal transduction. Apoptosis-linked gene 2 is a calcium-binding protein required for cell death induced by different apoptotic stimuli. By Western blot analysis, we found that apoptosis-linked gene 2 protein was expressed in normal brains, and that expression increased in ischemic brains after 20 or 90 min of transient focal cerebral ischemia. Immunocytochemistry showed increased apoptosis-linked gene 2 protein expression in frontal cortex, a region where neurons underwent ischemic stress but still survived, after 20 or 90 min of focal cerebral ischemia. Apoptosis-linked gene 2 protein was also up-regulated in the ischemic border-zone of parietal cortex 24h after 20 min of focal ischemia, and was remarkably over-expressed in the caudate-putamen and parietal cortex, (where cells are destined to die) 24h after 90 min of ischemia. The expression pattern of apoptosis-linked gene 2 protein was similar to that of deoxyribonucleic acid damage detected by Klenow labeling assay. Our results suggest that apoptosis-linked gene 2 may be involved in the regulation of cell death after transient focal cerebral ischemia.
Animals↗
High-performance liquid chromatography-electrospray ionization-mass spectrometry study of ginkgolic acid in the leaves and fruits of the ginkgo tree (Ginkgo biloba).
A method is developed for qualitative analysis of ginkgolic acids in the leaves and fruits of Ginkgo biloba by high-performance liquid chromatography (HPLC)-electrospray ionization-mass spectrometry technique. Negative ionization mode is successful in obtaining a very abundant deprotonated molecule [M - H]-. The mass detection sensitivity is higher than ultraviolet detection but relies heavily on the concentration of acetic acid in the HPLC eluent, which consists of acetonitrile-water-acetic acid. The method is also very specific for the analysis of ginkgolic acid with no interferences from the sample matrix.
Acetic Acid↗
Infusion of recombinant human acid sphingomyelinase into niemann-pick disease mice leads to visceral, but not neurological, correction of the pathophysiology.
An inherited deficiency of acid sphingomyelinase (ASM) activity results in the Type A and B forms of Niemann-Pick disease (NPD). Using the ASM-deficient mouse model (ASMKO) of NPD, we evaluated the efficacy of enzyme replacement therapy (ERT) for the treatment of this disorder. Recombinant human ASM (rhASM) was purified from the media of overexpressing Chinese Hamster ovary cells and i.v. injected into 16 five-month-old ASMKO mice at doses of 0.3, 1, 3, or 10 mg/kg every other day for 14 days (7 injections). On day 16, the animals were killed and the tissues were analyzed for their sphingomyelin (SPM) content. Notably, the SPM levels were markedly reduced in the hearts, livers, and spleens of these animals, and to a lesser degree in the lungs. Little or no substrate depletion was found in the kidneys or brains. Based on these results, three additional 5-month-old ASMKO animals were injected every other day with 5 mg/kg for 8 days (4 injections) and killed on day 10 for histological analysis. Consistent with the biochemical results, marked histological improvements were observed in the livers, spleens, and lungs, indicating a reversal of the disease pathology. A group of 10 ASMKO mice were then i.v. injected once a week with 1 mg/kg rhASM for 15 wk, starting at 3 wk of age. Although anti-rhASM antibodies were produced in these mice, the antibodies were not neutralizing and no adverse effects were observed from this treatment. Weight gain and rota-rod performance were slightly improved in the treated animals as compared with ASMKO control animals, but significant neurological deficits were still observed and their life span was not extended by ERT. In contrast with these CNS results, striking histological and biochemical improvements were found in the reticuloendothelial system organs (livers, spleens, and lungs). These studies indicate that ERT should be an effective therapeutic approach for Type B NPD, but is unlikely to prevent the severe neurodegeneration associated with Type A NPD.
Animals↗
Unwinding of a herpes simplex virus type 1 origin of replication (Ori(S)) by a complex of the viral origin binding protein and the single-stranded DNA binding protein.
A herpes simplex virus type 1 (HSV-1) Ori(S) analogue in which the A+T sequence linking the box I and II elements was replaced by two single-stranded oligo(dT)s is unwound by the UL9 protein-ICP8 complex. Unwinding of wild-type Ori(S) by the UL9 protein-ICP8 complex was also observed under conditions which destabilize the A+T sequence. These experiments support a model for the unwinding of Ori(S) in which destabilization of the A+T sequence can generate a single-stranded DNA binding site for ICP8, which then associates with the UL9 protein bound to boxes I and II to promote the bidirectional unwinding of Ori(S).
Base Sequence↗
Inhibitory effect of NF-kappaB on 1,25-dihydroxyvitamin D(3) and retinoid X receptor function.
Responsiveness to 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] may be diminished in osteoporosis and inflammatory arthritis. The inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is produced in excess in these disorders and has been shown to decrease osteoblast transcriptional responsiveness to vitamin D and to inhibit the binding of the vitamin D receptor (VDR) and its nuclear partner the retinoid X receptor (RXR) to DNA. Previous studies have shown that a vitamin D (VDRE) or retinoid X DNA response element (RXRE) is sufficient to confer TNF-alpha inhibition of vitamin D or retinoid-stimulated transcription in the absence of known TNF-alpha-responsive DNA sequences. We tested the hypothesis that the TNF-alpha-stimulated transcription factor nuclear factor (NF)-kappaB could, in part, mediate TNF-alpha action by inhibiting the transcriptional potency of the VDR and RXR at their cognate cis regulatory sites. Osteoblastic ROS 17/2.8 cells transfected with a dose of NF-kappaB comparable to that stimulated by TNF-alpha decreased 1,25(OH)(2)D(3)-stimulated transcription. This inhibitory effect of NF-kappaB was not observed on basal transcription of a heterologous reporter in the absence of the VDRE. The effects of NF-kappaB and TNF-alpha were comparable but not additive. COS-7 cells were cotransfected with reporters under the regulation of VDRE or RXRE along with vectors expressing VDR, RXR, and NF-kappaB nuclear proteins. Reconstituted NF-kappaB and the NF-kappaB subunit p65 alone, but not p50, dose dependently suppressed basal and ligand-stimulated transcription. p65 overexpression completely abrogated enhanced VDRE-mediated transcriptional activity in response to 1,25(OH)(2)D(3). Electrophoretic mobility shift experiments did not reveal a direct effect of recombinant NF-kappaB or its individual subunits on the binding of heterodimeric VDR-RXR to DNA. These results suggest that TNF-alpha inhibition of hormone-stimulated transcriptional activation may be mediated by activation of NF-kappaB. In contrast, the inhibitory effect of TNF-alpha on binding of receptors to DNA is unlikely to be mediated by NF-kappaB and is not necessary for inhibition of transcription.
Animals↗
Inhibition of osteoblast differentiation by tumor necrosis factor-alpha.
Tumor necrosis factor-alpha (TNF-alpha) has a key role in skeletal disease in which it promotes reduced bone formation by mature osteoblasts and increased osteoclastic resorption. Here we show that TNF inhibits differentiation of osteoblasts from precursor cells. TNF-alpha treatment of fetal calvaria precursor cells, which spontaneously differentiate to the osteoblast phenotype over 21 days, inhibited differentiation as shown by reduced formation of multilayered, mineralizing nodules and decreased secretion of the skeletal-specific matrix protein osteocalcin. The effect of TNF was dose dependent with an IC50 of 0.6 ng/ml, indicating a high sensitivity of these precursor cells. Addition of TNF-alpha from days 2-21, 2-14, 7-14, and 7-10 inhibited nodule formation but addition of TNF after day 14 had no effect. Partial inhibition of differentiation was observed with addition of TNF on only days 7-8, suggesting that TNF could act during a critical period of phenotype selection. Growth of cells on collagen-coated plates did not prevent TNF inhibition of differentiation, suggesting that inhibition of collagen deposition into matrix by proliferating cells could not, alone, explain the effect of TNF. Northern analysis revealed that TNF inhibited the expression of insulin-like growth factor I (IGF-I). TNF had no effect on expression of the osteogenic bone morphogenic proteins (BMPs-2, -4, and -6), or skeletal LIM protein (LMP-1), as determined by semiquantitative RT-PCR. Addition of IGF-I or BMP-6 to fetal calvaria precursor cell cultures enhanced differentiation but could not overcome TNF inhibition, suggesting that TNF acted downstream of these proteins in the differentiation pathway. The clonal osteoblastic cell line, MC3T3-E1-14, which acquires the osteoblast phenotype spontaneously in postconfluent culture, was also studied. TNF inhibited differentiation of MC3T3-E1-14 cells as shown by failure of mineralized matrix formation in the presence of calcium and phosphate. TNF was not cytotoxic to either cell type as shown by continued attachment and metabolism in culture, trypan blue exclusion, and Alamar Blue cytotoxicity assay. These results demonstrate that TNF-alpha is a potent inhibitor of osteoblast differentiation and suggest that TNF acts distal to IGF-I, BMPs, and LMP-1 in the progression toward the osteoblast phenotype.
Adaptor Proteins, Signal Transducing↗
Accumulation of T cells reactive to type II collagen in synovial fluid of patients with rheumatoid arthritis.
OBJECTIVE: To determine if type II collagen (CII) reactive T lymphocytes selectively accumulate in the inflamed joint of patients with rheumatoid arthritis (RA) and to study the specificity of the CII reactive cells. METHODS: Synovial fluid (SF) cells or peripheral blood lymphocytes were cultured with interleukin 2 (IL-2) for 24 h and then cultured at limiting dilution concentrations in the presence of filler cells and IL-2. The outgrowing cell lines were screened for their responses to CII. The percentages of the CII reactive T cells from SF were compared with those from peripheral blood of patients with RA. The CII reactive T cell lines were tested for their responses to different types of collagen. RESULTS: CII reactive T cell lines were identified in the SF of 3 RA patients; the frequencies were 5.0% (11/219), 3.7% (5/134), and 3.5% (3/86), respectively. In contrast, none of CII-specific T cell lines were identified in peripheral blood of the patients. The T cell lines recognized both human and bovine CII and, to a lesser extent, type I collagen. CONCLUSION: CII reactive T cells are present in high frequency in the inflamed joint of patients with RA, where they may play an important role in the pathogenesis of RA.
Animals↗
Indoor coal combustion emissions, GSTM1 and GSTT1 genotypes, and lung cancer risk: a case-control study in Xuan Wei, China.
The lung cancer mortality rate in Xuan Wei County, China is among the highest in the country and has been associated with exposure to indoor smoky coal emissions that contain high levels of polycyclic aromatic hydrocarbons. This risk may be modified by variation in metabolism genes, including GSTM1, which encodes an enzyme known to detoxify polycyclic aromatic hydrocarbons. To investigate the relationship between GST genotypes and lung cancer risk in Xuan Wei County, we analyzed GSTM1 and GSTT1 genotypes in a population-based case-control study. A total of 122 lung cancer patients and 122 controls, individually matched by age, sex, and home fuel type, were studied. Compared to subjects who used less than 130 tons of smoky coal during their lifetime, heavier users (> or =130 tons) had a 2.4-fold (95% confidence interval, 1.3-4.4) increased risk of lung cancer. The GSTM1-null genotype was associated with a 2.3-fold (95% confidence interval, 1.3-4.2) increased risk of lung cancer. Furthermore, there was some evidence that smoky coal use was more strongly associated with lung cancer risk among GSTM1-null versus GSTM1-positive individuals. In contrast, the GSTT1 genotype was not significantly associated with lung cancer risk. Our data suggest that the GSTM1-null genotype may enhance susceptibility to air pollution from indoor coal combustion emissions.
Air Pollution, Indoor↗
Actions of NO and INOS on endotoxin induced rat acute lung injury and effect of rhubarb on them.
This study is to explore the actions of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) on endotoxin (lipopolysaccharide, LPS) induced rat acute lung injury (ALI) and effect of Rhubarb on them. LPS was injected into the sublingual vein of male Wistar rats to prepare ALI animal models. The rats were divided into 4 groups: LPS, control, Rhubarb, and dexamethasone. Macroscopic and histopathological examinations of the lung specimens were performed and the biological indexes of lung, including wet weight/dry weight, the rate of neutrophils and protein content in the pulmonary alveolar lavage fluid, pulmonary vascular permeability and pulmonary alveolar permeability were observed. In the mean time, the contents of serum NO and the activities of lung tissue homogenate iNOS were measured. The results showed that in the LPS group, the injury and celluar infiltration in the pulmonary stroma and alveoli were more prominent than that in the control group. Lung wet weight/dry weight, the rate of neutrophils, protein content, pulmonary alveolar permeability, pulmonary vascular permeability were significantly increased (P < 0.01); NO and iNOS were also markedly elevated (P < 0.01). In the groups of dexamethasone and Rhubarb, the histopathological changes were significantly milder, and all the above biological indexes of lung injury and the contents of NO and the activities of iNOS were correspondingly decreased (P < 0.05). The above data demonstrate that NO and iNOS play an important role in the onset of ALI; dexamethasone and Rhubarb interfering treatment can ameliorate lung injury and decrease the concentrations of NO and the activities of iNOS, showing that through inhibiting the levels of NO and the activities of iNOS, these 2 agents exert protective effect on ALI induced LPS.
Animals↗
Pharmacophore/receptor models for GABA(A)/BzR alpha2beta3gamma2, alpha3beta3gamma2 and alpha4beta3gamma2 recombinant subtypes. Included volume analysis and comparison to alpha1beta3gamma2, alpha5beta3gamma2, and alpha6beta3gamma2 subtypes.
Pharmacophore/receptor models for 6 recombinant GABA(A)/BzR subtypes (alphax beta3gamma2, x = 1-6) have been established via an SAR ligand mapping approach. This study was based on the affinities of 166 BzR ligands at 6 distinct (alpha1-6beta3gamma2) recombinant GABA(A)/BzR receptor subtypes from at least twelve different structural families. Examination of the included volumes indicated that the shapes of binding pockets for alpha1, alpha2 and alpha3 subtypes are very similar to each other. Region L2 for the alpha5 containing subtype appeared to be larger in size than the analogous region of the other receptor subtypes. Region L(Di), in contrast, appeared to be larger in the alpha1 subtype than in the other subtypes. Moreover, region L3 in the alpha6 subtype is either very small or nonexistent in this diazepam insensitive "DI" subtype as compared to the other subtypes. Preliminary results for the alpha4-containing receptor subtype (DI) indicate that L3 in the alpha4 subtype suffers a similar fate. Use of the pharmacophore/receptor models for these subtypes have resulted in the design of novel BzR ligands selective for the alpha5beta3gamma2, receptor subtype.
Animals↗
[Construction of B. thuringiensis shuttle vector and expression of the cry1C gene].
We have constructed the E. coli-Bt shuttle vector pHV-1 by cloning the replicon (approximately 1.6 kb) of Bt ken-Ag and the aphI gene of pUC4K into pUC19. The rate of plasmid maintenance is more than 80% after 100 generations in E. coli, whereas 80% after 40 generations in Bti 4Q8. We have also constructed pHV-cry1C through cloning the alpha-amylase promoter from B. licheniformis and the cry1C gene from Bt 9510 into pHV-1 and introduced it into Bti 4Q8 by means of electroporation. Under the microscope, we can see that there is no crystal in Bti 4Q8, however, there are many rhomboid crystals in Bti 4Q8 (pHV-cry1C), which are smaller than those of Bt 9510. The bioassay result of Bti 4Q8 (pHV-cry1C) demonstrates that the expressed crystal protein is insecticidally active against Spodoptera exigue.
Animals↗
Hierarchical processing and level-repetition effect as indexed by early brain potentials.
Event-related potentials were recorded to investigate the mechanisms of hierarchical processing and level-repetition effect. Participants identified targets that appeared at global, local, or both levels of hierarchical patterns. Reaction times showed global precedence and level-repetition effects. An occipital P1 wave was enhanced to local relative to global targets. The P1 to local targets was also larger when preceded by global than local targets. Global and both-level target selections were indexed by two posterior negativities peaking at 130 and 190 ms poststimulus, whereas local target selection was indexed by a broad occipitotemporal negativity. A late selection positivity was observed over the left occipitotemporal site for global targets but over the central site for local targets. The findings suggest that sensory-perceptual mechanisms contribute to global precedence and level-repetition effects in hierarchical processing.
Adult↗
[Changes of hepatic energy metabolism following partial hepatopetal blood occlusion].
OBJECTIVE: To evaluate the changes of hepatic energy metabolism by temporary occlusion of partial hepatopetal blood. METHODS: The animal mode of partial hepatopetal blood occlusion (PBO) was established without portal stasis. The hepatic energy metabolism parameters including adenosine triphosphate, respiratory control ratio, P/O ratio, and arterial ketone bodies ratio were studied following 30 min ischemia or 1, 6, and 24 h of reperfusion. The total hepatopetal blood occlusion (TBO) and sham groups served as control. RESULTS: The parameters of hepatic motochondrial function reflecting hepatic damage to ischemia-reperfusion showed different in PBO comparing with TBO group. The functional lesion was restored progressively in PBO-30 min group, but it was maintained low level in TBO-30 min group. CONCLUSION: The results suggest that it is beneficial to restoration of the hepatic energy metabolism in the ischemia-reperfusion injury by partial hepatopetal blood occlusion.
Adenosine Triphosphate↗
[Mycorrhizal research on nitrogen-fixing plants].
Advances in mycorrhizal research on nitrogen-fixing plants were introduced. The universality of mycorrhizal formation in nitrogen fixing plants, the reciprocal promotion effect of symbiosis, and the application prospect of mycorrhizal techniques under stressed conditions were summarized and reviewed. The mechanism of enhancing nitrogen fixation of N-fixing plants by mycorrhizal fungi in symbiosis was preliminary discussed.
Fungi↗
Effect of preoperative transcatheter arterial chemoembolization on tumor cell activity in hepatocellular carcinoma.
OBJECTIVE: To evaluate the role of preoperative transcatheter arterial chemoembolization (TACE) as a palliative approach in hepatocellular carcinoma (HCC). METHODS: From January 1992 to December 1998, 279 patients with HCC underwent curative liver resection. One to five courses of TACE prior to liver resection were performed in 117 patients (TACE group), while the other 162 patients received only liver resection (control group). All 279 specimens of resected tumors were submitted to the following assessments: PCNA and expression of P53 protein. All specimens from the TACE group were examined for downstaging or necrosis of tumors. RESULTS: In the TACE group, gross inspection revealed downstaging or necrosis of tumor in all cases. Total necrosis (100%) of tumor was observed in 11.1% of 117 patients, > 90% but incomplete necrosis in 15.4%, 50%-90% necrosis in 46.2% and < 50% necrosis in 27.3%. Microscopically, extensive and homogenous coagulative necrosis was observed. Viable cancer cells were also present within and outside the tumor capsule in 111 cases. In the remaining 6 cases, the tumor necrosed completely. In control group, necrosis was observed in 8.0% of 162 cases and reduction of tumor size was < 20%. Microscopically, viable HCC cells were noted in all cases. There was no statistical difference in expression of P53 protein between the TACE and control group. High labeling index of PCNA was significantly higher in the TACE group. CONCLUSIONS: TACE has a marked antitumor effect resulting in various degree of tumor necrosis, but only a small proportion of tumors show complete necrosis. Since the residual tumor cells following preoperative TACE may have more aggressive behavior, we conclude that sequential liver resection is the preferred therapy whenever feasible and preoperative TACE should be avoided in resectable HCC.
Adult↗
[The immunogenic characteristics of the recombinant 38,000 antigen from Mycobacterium tuberculosis].
OBJECTIVE: To study the ability of recombinant 38,000 protein of Mycobacterium tuberculosis (rMT38) to induce antibodies and its value as a serological diagnostic reagent. METHODS: Rabbits were divided into six groups, namely: PPD + physiological saline(group A), rMT38 + physiological saline(group B), rMT38 + adjuvent(group C), 1/2 rMT38 + 1/2 rMT16 + physiological saline(group D), 1/2 rMT38 + 1/2 rMT16 + adjuvent(group E), rMT16 + adjuvent(group F). The sera from the immunized rabbits and the sera immunized by mycobacteria were evaluated by enzyme-linked immunosorbent assay(ELISA) and bilateral agar diffusion assay (BADA). 389 human sera, including 145 patients with pulmonary tuberculosis, 105 healthy controls, 31 non-tuberculosis respiratory patients, 78 BCG-vaccinated healthy controls and 30 patients with M. abscessus infection, were detected by ELISA. RESULTS: Titers of specific antibodies in sera from C and E groups were 1:16 and 1:4 in BADA, and 1:6,400 and 1:3,200 in ELISA, respectively. Precipitate lines of sera from A, B, D, F groups reacting with rMT38 were not found by BADA. Sera titer of A, B, D, F groups were negative, 1:400, 1:400, and negative by ELISA, respectively. Sera from E group had no reaction with PPD from thirteen mycobacteria, however, sera from E group reacted with PPD from Mycobacterium tuberculosis and BCG. Sera titer of all rabbits decreased with time. After two months, serum titers in B and D groups became negative. However, antibodies were still found in C and E groups after five months. The sensitivity of rMT38 and PPD in detecting pulmonary tuberculosis were 69.0% and 75.2%, respectively. The specificity of rMT38 and PPD in detecting healthy controls, non-tuberculosis respiratory patients, BCG-vaccinated healthy controls and M. abscessus-infected patients were 97.1%, 93.5%, 86.0%, 53.6% and 94.3%, 87.1%, 67.9%, 39.3% respectively. CONCLUSION: rMT38 has a strong immunogenicity, which may be used as an immunodiagnostic reagent for tuberculosis.
Animals↗