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1.
Pertussis toxin (PT) inhibited luminol-enhanced chemiluminescence induced in rabbit peritoneal neutrophils by N'-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) at doses as low as 0.8 ng.ml-1, even in the presence of a 10-fold higher concentration of filamentous haemagglutinin (FHA). A cell-free extract of Bordetella pertussis, containing predominantly PT and FHA, suppressed the neutrophil response to fMLP. After toxoiding with carbodiimide, the inhibitory activity of the extract was abolished and an enhancement of neutrophil chemiluminescence was observed due to FHA activity. Abrogation of the chemiluminescent response of neutrophils to fMLP is proposed as a sensitive, in vitro assay for pT, and may be useful for monitoring the residual toxin activity in pertussis toxoids and for determining the anti-toxic effects of anti-PT antibodies.  相似文献   

2.
The effect of secreted virulence components of Bordetella pertussis on chemiluminescence (CL) of rabbit peritoneal neutrophils was determined with the chemotactic peptide N'-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) or intact B. pertussis as the stimulus. Pertussis toxin (PT) inhibited the response to fMLP in a dose-dependent manner, although only after the neutrophils had been exposed to the toxin for greater than 15 min. Both filamentous haemagglutinin (FHA) and lipopolysaccharide (LPS) markedly enhanced the CL response to fMLP after greater than or equal to 15 min incubation with the neutrophils. Similar effects to those of B. pertussis LPS were also seen with smooth and rough LPS from Salmonella minnesota. With the lowest dose of each component which elicited a maximal effect on CL, the inhibitory effect of PT overrode the enhancing effect of FHA and B. pertussis LPS. Pre-incubation of neutrophils with PT, FHA or B. pertussis LPS caused a slight reduction in the subsequent CL response to virulent B. pertussis Tohama. Virulent (phase I, or X-mode) organisms of B. pertussis 18334 and B. pertussis Tohama induced greater neutrophil CL than their avirulent (C-mode) derivatives. There appeared to be an inverse correlation between bacterial hydrophilicity and the ability to induce neutrophil CL: X-mode bacteria were significantly less hydrophilic than C-mode organisms. Three mutants, the adenylate cyclase (AC)- and haemolysin (HLY)-deficient B. pertussis BP348, the FHA-deficient B. pertussis BP353, and the PT-deficient B. pertussis BP357, generated similar levels of CL and had similar hydrophilicity values. The hydrophilicity value of the avirulent mutant B. pertussis BP347 (deficient in AC, HLY, FHA and PT) and the CL induced by this strain were similar to those of B. pertussis C-mode organisms. Thus, the interaction of B. pertussis with neutrophils appears to be complex, reflecting both the alteration of leucocyte function by secreted virulence components of the organism and, in the absence of opsonins, the surface properties of the bacterium.  相似文献   

3.
Inhibition of lymphocyte and neutrophil chemotaxis by pertussis toxin   总被引:16,自引:0,他引:16  
The cells of the mammalian immune system possess special migratory properties within their in vivo environment, a surveillance characteristic that is thought to be important in the protection of the organism from transformants and exogenous pathogens. Pertussis toxin (PT) has been shown to disrupt the intensity of this process by seriously affecting lymphocyte recirculation in vivo. The mechanisms responsible for this inhibition were investigated by using the in vitro model systems of polymorphonuclear leukocyte and lymphocyte chemotaxis. The type of inhibition that was observed in these in vitro assay systems was quite similar to that observed in vivo, because PT could depress chemotaxis in vitro as well as the accumulation of radiolabeled lymphocytes and neutrophils within a peripheral site of inflammation in vivo. The alterations in neutrophil motility were found to be associated with a stimulus-specific inhibition of the triggering of superoxide anion generation and lysosomal secretion. Some inhibition of neutrophil adherence to plastic surfaces was also observed, most notably after augmentation of adherence with the chemoattractant fMLP. The observed alterations in cellular function after PT treatment occurred in the absence of defects in chemoattractant binding to the neutrophil cell surface, or of membrane potential changes stimulated by ligand binding. The effect of PT in this system was found to be associated with an abnormality in the regulation of intracellular free calcium, suggesting that the substrate for PT in neutrophils is involved in the regulation of calcium ion channels.  相似文献   

4.
The activation of leukocytes by particulates is a critical event in certain inflammatory syndromes, including acute gout associated with microcrystals of monosodium urate monohydrate. In this study we have evaluated mechanisms of human neutrophil activation by urate crystals. Both N-formyl-nor-leu-leu-phe-nor-leu-tyr-lys and uncoated urate crystals (0.5 to 5 mg/ml) but not urate crystals coated with human low density lipoprotein (which suppresses crystal-induced neutrophil responsiveness), stimulated pertussis toxin (PT)-sensitive GTPase activity in purified preparations of human neutrophil membranes. Hydroxyapatite crystals (up to 5 mg/ml) were inactive. Pretreatment of neutrophil membranes with cholera toxin also inhibited crystal-induced and formylated peptide-induced GTPase activity. Pretreatment of whole neutrophils with PT resulted in nearly complete inhibition of formylated peptide-induced cytosolic calcium mobilization, release of superoxide and release of the azurophil granule constituent alpha-mannosidase. In contrast, identical pretreatment of whole neutrophils with PT only partially suppressed urate crystal-induced alpha-mannosidase and superoxide release and failed to inhibit crystal phagocytosis and increases in cytosolic free calcium. Mechanisms of neutrophil activation by monosodium urate crystals appear to be heterogeneous in comparison with activation by formylated peptides and there is no absolute requirement for PT-sensitive membrane G proteins in neutrophil responsiveness to urate crystals.  相似文献   

5.
The addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to human peripheral blood neutrophils primes phospholipase D (PLD) to subsequent stimulation by N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol myristate acetate (PMA). The present investigation was directed at the elucidation of the pathway(s) involved in the regulation of the activity of PLD in untreated as well as in GM-CSF-primed neutrophils. Pretreatment with pertussis toxin (PT) totally inhibited fMLP-induced activation of PLD in control or GM-CSF-treated cells. PT did not affect the activation of PLD by PMA but inhibited the priming effect of GM-CSF. Activation of PLD by fMLP was dose-dependently inhibited by erbstatin, an inhibitor of tyrosine kinases. Furthermore, pre-incubation with GM-CSF accelerated the tyrosine phosphorylation response to fMLP (as analysed by protein immunoblot with antiphosphotyrosine antibodies). In PMA-stimulated neutrophils, erbstatin antagonized the priming effect of GM-CSF on PLD without affecting the direct effects of the phorbol ester. Buffering cytoplasmic calcium with the chelator BAPTA inhibited fMLP-induced activation of PLD as monitored by the formation of phosphatidylethanol. The stimulation of PLD by PMA was partially attenuated in BAPTA-loaded cells while the priming effect of GM-CSF was abolished. Thus, priming of human neutrophil PLD by GM-CSF may be mediated by G-proteins, by increases in the levels of cytosolic free calcium, and by stimulation of protein kinase C and/or tyrosine kinase(s).  相似文献   

6.
The role of neutrophil chemoattractant receptors in neutrophil stimulation in vitro is well established, however, the precise mechanisms underlying local neutrophil accumulation at inflammatory sites in vivo have not been defined. A fundamental question that remains open is whether chemoattractants act on the endothelial cell or the neutrophil to initiate the process of neutrophil migration in vivo. To address this question we have investigated whether neutrophil accumulation in vivo can occur if chemoattractant receptor occupancy is uncoupled from neutrophil stimulation. For this purpose we have used pertussis toxin (PT) as the pharmacologic tool. We have investigated the effect of in vitro pretreatment of rabbit neutrophils with PT on their responses in vitro and on their accumulation in vivo. Pretreatment of rabbit neutrophils with PT inhibited FMLP- and C5a-, but not PMA- induced increases in CD18 expression, neutrophil adherence, and degranulation in vitro. This pretreatment procedure with PT inhibited the accumulation of radiolabeled neutrophils in vivo in response to intradermally injected FMLP, C5a, C5a des Arg, leukotriene B4, IL-8, and zymosan in rabbit skin. Further, in contrast to the in vitro results, PT inhibited the PMA-induced 111In-neutrophil accumulation in vivo. Interestingly, pretreatment of neutrophils with PT also inhibited accumulation in response to intradermally injected IL-1, despite the reports that IL-1 lacks neutrophil chemoattractant activity in vitro. Although the experimental techniques used cannot distinguish the different stages of neutrophil migration involved, these results suggest that the accumulation of neutrophils induced by local extravascular chemoattractants in vivo depends on a pertussis toxin-sensitive receptor operated event on the neutrophil itself. Further, PMA and IL-1 may release secondary chemoattractants in vivo.  相似文献   

7.
The hemagglutinating (HA) activities of purified pertussis toxin (PT) and filamentous hemagglutinin (FHA) were evaluated against unfixed and glutaraldehyde-fixed erythrocytes from ox, goose, horse, monkey, sheep, chicken, and rabbit. Both PT and FHA showed HA activities against fixed and unfixed erythrocytes from all the animals studied. The HA titers of FHA were higher than those of PT. The HA activities of FHA and PT were not destroyed completely even after heating these preparations at 56 C for 30 min. A simple test for the assay of PT in culture supernatants of Bordetella pertussis on the basis of HA activity has been described.  相似文献   

8.
In a mouse model of respiratory tract infection by Bordetella pertussis, bacteria multiply in the airways over the first week and are then cleared over the next 3–4 weeks by the host immune response. Pertussis toxin (PT), a virulence factor secreted exclusively by B. pertussis, promotes bacterial growth in the airways by suppression and modulation of host immune responses. By comparison of wild type and PT-deficient strains, we examined the role of PT in modulating airway cytokine and chemokine responses affecting neutrophil recruitment during B. pertussis infection in mice. We found that, despite early inhibition of neutrophil recruitment by PT, high numbers of neutrophils were recruited to the airways by 4 days post-infection with the wild type strain, but not with the PT-deficient strain, and that this correlated with upregulation of neutrophil-attracting chemokine gene expression. In addition, there was similar upregulation of genes expressing the cytokines IL-17A (IL-17), TNF-α and IFN-γ, indicating a mixed Th1/Th17 response. Expression of IL-6, a cytokine involved in Th17 induction, was upregulated earlier than the IL-17 response. We showed that PT, rather than bacterial numbers, was important for induction of these responses. Flow cytometric analysis revealed that the IL-17-producing cells were macrophages and neutrophils as well as T cells, and were present predominantly in the airways rather than the lung tissue. Antibody neutralization of IL-17 significantly reduced chemokine gene expression and neutrophil recruitment to the airways, but only modestly increased peak bacterial loads. These data indicate that PT stimulates inflammatory responses by induction of Th1- and Th17-associated cytokines, including IL-17, during B. pertussis infection in mice, but a role for IL-17 in protection against the infection remains to be established.  相似文献   

9.
Acellular pertussis vaccines typically consist of antigens isolated from Bordetella pertussis, and pertussis toxin (PT) and filamentous hemagglutinin (FHA) are two prominent components. One of the disadvantages of a multiple-component vaccine is the cost associated with the production of the individual components. In this study, we constructed an in-frame fusion protein consisting of PT fragments (179 amino acids of PT subunit S1 and 180 amino acids of PT subunit S3) and a 456-amino-acid type I domain of FHA. The fusion protein was expressed by the commensal oral bacterium Streptococcus gordonii. The fusion protein was secreted into the culture medium as an expected 155-kDa protein, which was recognized by a polyclonal anti-PT antibody, a monoclonal anti-S1 antibody, and a monoclonal anti-FHA antibody. The fusion protein was purified from the culture supernatant by affinity and gel permeation chromatography. The immunogenicity of the purified fusion protein was assessed in BALB/c mice by performing parenteral and mucosal immunization experiments. When given parenterally, the fusion protein elicited a very strong antibody titer against the FHA type I domain, a moderate titer against native FHA, and a weak titer against PT. When given mucosally, it elicited a systemic response and a mucosal response to FHA and PT. In Western blots, the immune sera recognized the S1, S3, and S2 subunits of PT. These data collectively indicate that fragments of the pertussis vaccine components can be expressed in a single fusion protein by S. gordonii and that the fusion protein is immunogenic. This multivalent fusion protein approach may be used in designing a new generation of acellular pertussis vaccines.  相似文献   

10.
We have characterized the GTPase activity of the Ni-like guanine-nucleotide-binding regulatory protein in rabbit neutrophil plasma membranes. The low Km (3.64 +/- 0.87 X 10(-7) M) GTPase copurified with the formyl peptide receptor in the plasma membrane fraction obtained by discontinuous sucrose density gradient centrifugation. The Vmax (23.9 +/- 2.91 pmol/mg/min) and Km of the unstimulated enzyme were similar to those reported for Ni in other cell types. The activity of the unstimulated enzyme was both magnesium and sodium dependent and linear over the first 4 min of the assay. The chemoattractants, formyl-methionyl-leucyl-phenylalanine (fMLP), C5a, and leukotriene B4 (LTB4) stimulated the GTPase in purified neutrophil plasma membrane preparations, whereas other secretagogues, such as A23187 and PMA, were without effect. Lineweaver-Burk analysis showed an fMLP-induced increase in Vmax (31.94 +/- 4.80 pmol/mg/min) (33.1 +/- 9.5%) but not in Km. The dose-response curve for fMLP stimulation showed an ED50 of 4.1 +/- 1.0 X 10(-8) M and an overall 22.2 +/- 3.1% maximal stimulation. C5a (30 micrograms/ml) increased the activity of the GTPase 21.3 +/- 5.7% and 10(-7) M LTB4 produced a 32.2 +/- 5.4% increase. Activated pertussis toxin treatment of neutrophil plasma membranes inhibited by 72.5 +/- 14.3% the stimulation of GTPase activity induced by fMLP; however, activated cholera toxin had no effect on the inhibition of fMLP stimulation, suggesting a direct role for an Ni-like protein in the coupling process. In contrast to the lack of inhibition of fMLP stimulation by activated cholera toxin treatment of plasma membranes, both pertussis toxin and to a lesser extent cholera toxin treatment reduced fMLP, C5a, and LTB4 stimulation of the GTPase in sonicates prepared from pretreated whole cells. Pertussis toxin inhibited fMLP stimulation of the GTPase by 75 +/- 7%, C5a stimulation was inhibited by 83 +/- 13%, and LTB4 stimulation was inhibited completely. Sonicates prepared from neutrophils treated similarly with cholera toxin showed a smaller inhibition of GTPase activity (50 +/- 4% and 14 +/- 9% for fMLP and LTB4, respectively) with the exception of C5a, where CT inhibition (81 +/- 32%) equaled pertussis toxin inhibition. Similarly, pertussis toxin completely inhibited the release of the granule enzyme N-acetyl-glucosaminidase by all three chemoattractants, whereas cholera toxin, except with C5a stimulation, had little or no effect.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

11.
为扩大生产,采用500立升发酵罐培养无细胞百日咳菌苗,发现随着培养时间的延续,细胞浓度增高,培养液的pH值上升,PT、FHA活性、血凝效价逐渐增加、O2溶压下降、CO2溶压上升。pH值达82时,PT活性最高为300EU/ml,较现用扁瓶培养方法高5倍。pH值继续上升时,PT活性开始下降。FHA活性及血凝效价具有相似的变化。通过测定培养液pH值以确定收获时间,可获得富含PT、FHA、且活性均保持较高水平的培养液  相似文献   

12.
The aim of this study was to determine and evaluate IgG, IgM and IgA levels to pertussis toxin (PT), filamentous hemagglutinin (FHA) and endotoxin (LPS) of B. pertussis in children with clinical symptoms of whooping cough. The serum samples obtained from 265 children (age range: 2 months-16 years) suspected of pertussis were examined by indirect haemagglutination (IH) and ELISA tests. Higher antibody level was most frequently observed in IgA class to PT, FHA and LPS in 45.3%, 35.1% and 66% of pertussis patients sera respectively. The least positive results were obtained in IgM class to PT and FHA (in 9.8% and 2.6% of children sera respectively) but in the case of LPS applied as the antigen in ELISA, higher IgM level was determined in 46.8% of pertussis patients sera. The four times increase of antibody level to LPS determined by IH was observed in 86.7% of children suspected of pertussis. Humoral response to B. pertussis infection is mainly connected with higher IgA level to PT, FHA, LPS and IgM to LPS in children with clinical symptoms of whooping cough.  相似文献   

13.
The effects of highly purified preparations of three Bordetella pertussis components--pertussis toxin (PT), lipopolysaccharide (LPS) and filamentous haemagglutinin (FHA)--were examined in the mouse weight gain test, a toxicity test for pertussis vaccine. When these components were administered alone, PT enhanced initial weight gains of the mice, LPS produced an initial weight loss and FHA had no detectable effect on the weights of the mice. However, testing the components in combinations revealed that the effect of PT and LPS together was not simply the sum of their individual effects. This combination generally produced lower weights than LPS alone, particularly in the later stages of the test.  相似文献   

14.
Acellular pertussis vaccines typically consist of antigens isolated from Bordetella pertussis, and pertussis toxin (PT) and filamentous hemagglutinin (FHA) are two prominent components. One of the disadvantages of a multiple-component vaccine is the cost associated with the production of the individual components. In this study, we constructed an in-frame fusion protein consisting of PT fragments (179 amino acids of PT subunit S1 and 180 amino acids of PT subunit S3) and a 456-amino-acid type I domain of FHA. The fusion protein was expressed by the commensal oral bacterium Streptococcus gordonii. The fusion protein was secreted into the culture medium as an expected 155-kDa protein, which was recognized by a polyclonal anti-PT antibody, a monoclonal anti-S1 antibody, and a monoclonal anti-FHA antibody. The fusion protein was purified from the culture supernatant by affinity and gel permeation chromatography. The immunogenicity of the purified fusion protein was assessed in BALB/c mice by performing parenteral and mucosal immunization experiments. When given parenterally, the fusion protein elicited a very strong antibody titer against the FHA type I domain, a moderate titer against native FHA, and a weak titer against PT. When given mucosally, it elicited a systemic response and a mucosal response to FHA and PT. In Western blots, the immune sera recognized the S1, S3, and S2 subunits of PT. These data collectively indicate that fragments of the pertussis vaccine components can be expressed in a single fusion protein by S. gordonii and that the fusion protein is immunogenic. This multivalent fusion protein approach may be used in designing a new generation of acellular pertussis vaccines.  相似文献   

15.
An acellular pertussis vaccine manufactured by Biken was investigated for purity, potency and toxicity. The vaccine was composed of almost equal proportions of pertussis toxin (PT) and filamentous hemagglutinin (FHA). The purity of the vaccine was 97-99%. The protective effects of component vaccines containing various ratios of PT and FHA were tested and it was found that the ratio of 1:1 provided the most effective vaccine.  相似文献   

16.
Diacylglycerol has gained wide acceptance as an important second messenger in the signal transduction mechanism by which occupancy of certain membrane receptors such as the formyl peptide receptor of neutrophils leads to biological responses, but supporting evidence for this proposed role is limited. We have utilized a recently developed diacylglycerol kinase assay (Preiss, J. E., Loomis, C. R., Bishop, W. R., Stein, R., Niedel, J. E., and Bell, R. M. (1986) J. Biol. Chem. 261, 8597-8600) to characterize the diacylglycerol response of normal human neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and other formyl peptides. fMLP alone stimulated a slow, prolonged 36% rise in diacylglycerol levels above basal levels. Cytochalasin B enhances several fMLP-stimulated neutrophil responses, including aggregation, superoxide production, and degranulation. Pretreatment of neutrophils with cytochalasin B markedly increased the rate and extent of the diacylglycerol response to fMLP stimulation. Diacylglycerol peaked at 5 min at 206 +/- 21% above basal levels with a t1/2 of 45 s. The diacylglycerol response was time- and fMLP and cytochalasin B concentration-dependent, appropriate for the known biological activities of several peptide analogues, and completely inhibited by pretreatment with pertussis toxin. These data demonstrate that diacylglycerol may function as a second messenger for neutrophil activation and suggest that cytochalasin B enhancement of neutrophil biology may be the result of an enhanced diacylglycerol response.  相似文献   

17.
Incubation of membranes of human erythrocytes and platelets but not of human neutrophils with [32P]NAD leads to covalent modification of various membrane proteins and of added albumin. In membranes of all three cell types, pertussis toxin (PT), in the presence of NAD, specifically labelled a 40 kDa peptide, i.e. the alpha-subunit of a guanine nucleotide-binding protein. This effect of PT was slightly reduced by NADP, whereas modification of other membrane proteins and of albumin was largely suppressed, independent of whether PT was present or not. Labelling of cytosolic proteins in the presence of NAD was marginal; only in neutrophil cytosol, PT modified a 40 kDa peptide. Membranes of erythrocytes and platelets exhibited NAD-degrading activity, which was inhibited by NADP. The data suggest a high substrate specificity of PT for NAD. Inhibition of endogenous enzymes by NADP may prove useful for the evaluation of PT substrates.  相似文献   

18.
In vitro effect of actinomycin D on human neutrophil function   总被引:1,自引:0,他引:1  
The effect of actinomycin D (ACT-D) on human neutrophil chemotaxis, chemiluminescence (CL), superoxide (O2-) production, phagocytic uptake, and intracellular bacterial killing has been examined. The viability of the ACT-D-treated neutrophils was 98% even at a concentration of 10 micrograms/ml for 4 hr. Using fMLP as the chemotactic factor, depressed chemotaxis was demonstrated following ACT-D (1-10 micrograms/ml) pretreatment of neutrophils as compared with the non-treated controls. Similar ACT-D pretreatment produced the depressed responses in phorbol myristate acetate-induced CL and superoxide production by neutrophils. Moreover, using heat-inactivated human serum as an opsonin for Salmonella enteritidis (NCTC 6676), there was a significant difference in intracellular killing (P less than 0.01) but no difference in phagocytic uptake between ACT-D-treated and non-treated neutrophils. These studies indicate that ACT-D profoundly impairs both intracellular bacterial killing by human neutrophil through an effect on respiratory burst activity and directed cell migration of human neutrophils.  相似文献   

19.
Athymic (nu/nu) and euthymic (+/nu) BALB/c mice were immunized with a whole cell pertussis vaccine or with an acellular vaccine which contained detoxified pertussis toxin (PT) and filamentous hemagglutinin (FHA). Only the euthymic mice were protected against intracerebral challenge with virulent Bordetella pertussis which implies involvement of T-cells. As a cell transfer from mice immunized with whole cell or acellular vaccine prior to the challenge did not protect naive euthymic recipients, cellular immunity seems to be non-protective as an effector mechanism. Mice could be protected passively against a challenge by administration of immune sera. Therefore, T-cell dependent humoral immune responses to B. pertussis appear to be crucial for protection. The humoral response was further studied with athymic and euthymic mice. In euthymic mice the whole cell vaccine induced antibodies to FHA, pililipopolysaccharides (LPS) and an outer membrane protein (OMP) preparation, whereas the acellular vaccine induced antibodies to PT, FHA and OMP. Both IgM and IgG could be detected. From the nude mice only those immunized with the whole cell vaccine showed an antibody response which consisted of low titres of IgM directed to LPS. Sera from both +/nu and nu/nu mice immunized with the whole cell vaccine were bactericidal in vitro. These data demonstrate that in the mouse model protection to intracerebral challenge with B. pertussis is T-cell dependent as is the humoral response to PT, FHA, OMP and pili. The T-independent B-cell activation by the whole cell preparation is due to the presence of LPS.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
The cell mediated immune response (CMI) against pertussis antigens following vaccination with the traditional Danish whole cell pertussis vaccine (WC-P) and the Japanese acellular pertussis vaccine (A-PV) JNIH-3 was studied in four adult human volunteers. Vaccination with the A-PV induced an in vitro proliferative response of peripheral blood lymphocytes to pertussis toxin (PT) subunits S2-S4, S3-S4 and S5 and the filamentous hemagglutinin (FHA), and a better serological response to native PT, detoxified PT (dPT) and FHA than the WC-PV. The induced CMI and serological response were followed over a period of 17 weeks, and were not seen to decline during this period. Further, an in vitro proliferative response to Bordetella pertussis agglutinogen 2 and 3 were demonstrated using lymphocytes from recently and not-so-recently pertussis-vaccinated adults.  相似文献   

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