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Ping Chen

Publications and source records attributed to Ping Chen.

At least 73 records · Page 4Linked to original sources
PubMed2006

[Effect of lenti-mCCL20 on the growth of mouse tumor].

OBJECTS: We aim at inducing a potent antitumor immune response via CCL20 expressing in situ tumor. METHODS: We constructed a recombinant lentivirus encoding mouse CCL20 cDNA and transduced the mouse mesenchymal stem cells (mMSCs) in vitro, and then selected the transfected cells to get a stable mixed mCCL20-expressing pool (named as lenti-mCCL20-mMSCs) with blasticidin. By the same means, we produced another pool named as lenti-null-mMSCs. The CT26 was mixed with lenti-mCCL20-mMSC and inoculated sc into the left hinder back of BALB/c mouse. And also the CT26 was alone, or mixed with lenti-null-mMSCs or parent mMSCs, and then inoculated sc into BALB/c mice serving as controls. RESULTS: We got a lenti-mCCL20-mMSCs expression construct. It was shown that mCCL20 increased intratumoral lymphocytes infiltration and facilitated tumor growth in syngeneic murine tumor model. CONCLUSIONS: CCL20 expressing in situ tumor enhances intratumoral lymphocytes infiltration but facilitates tumor growth. However, the mechanism involved remains to be further elucidated.

Animals↗
PubMed2006

[Effect of 1-year specific immunotherapy with standardized house dust mite vaccine on mild to moderate allergic asthmatic patients].

OBJECTIVE: To evaluate the clinical efficacy and safety of specific immunotherapy (SIT) with standardized house dust mite (HDM) vaccine on allergic asthmatic patients. METHODS: The investigation was a multicentre, randomized, double-blind, placebo-controlled clinical study. 132 patients with mild to moderate asthma who were allergic to HDM, recruited from three hospitals of China (The First Affiliated Hospital of Guangzhou Medical College, Shenyang General Military Hospital, Suzhou Children's Hospital), were randomly allocated to the active group (n = 66) or the control group (n = 66) respectively. The active group received SIT with a standardized depot Dermatophagoides pteronyssinus (Der p) extract absorbed to aluminium hydroxide (Alutard SQ, ALK-Abelló, Denmark), while the control group received a placebo containing histamine dihydrochloride by subcutaneous injections for 1 year. Treatment of each group was started from the initial concentration. Updosing was performed with weekly injections from four 10-fold dose-increase vials (active group: 100, 1,000, 10,000, 100,000 SQ-U/ml, control group: 0.01, 0.1, 1.0, 10 microg/ml. 100,000 SQ-U/ml of Der p extract contains 9.8 microg/ml of the majoy allergen Der p1). The single-dose was injected weekly with 0.2, 0.4, 0.8 ml of each concentration in turn from the preceding 3 vials, totally for 9 weeks. Subsequently, the dose with 0.1, 0.2, 0.4, 0.6, 0.8 ml of the highest concentration was injected weekly from the 10th-14th week and a maintenance dose with 1 ml was reached at the 15th week. The dosing interval was then gradually increased to 2, 4, 6 weeks until the end of the first 26-weeks updosing phase (phase I, H(1)). Thereafter, the dosing continued at 6-week intervals for maintenance phase (phase II, H(2)) till the end of the complete treatment. The patient was observed for at least 30 minutes in the clinic after each injection. RESULTS: A total of 132 subjects were randomized and 129 subjects (64 in the active group, 65 in the control group) completed the whole study. Dropouts included three females because of poor compliance, being afraid of the epidemic of Severe Acute Respiratory Syndrome (SARS) and emigration respectively. Both groups were comparable at baseline in all clinical and laboratory parameters. The mean daily symptom scores in 4-weekly began to diverge at the 29th-32nd week with the active group showing a significant lower scores (0.17 +/- 0.33) than the control group (0.39 +/- 0.74, Z = 2.031, P < 0.05) till the end of the study. Significant difference was found in average daily symptom scores between H(1) (0.29 +/- 0.39) and H(2) (0.19 +/- 0.27) in the active group (Z = 2.923, P < 0.01), while no significant difference was found between H(1) (0.45 +/- 0.62) and H(2) (0.40 +/- 0.68) in the placebo group (Z = 1.885, P > 0.05). There were significant differences in subjective judgement of the improvement about overall asthmatic symptoms, exacerbation severity and exacerbation frequency between the active group (96.9%, 95.3%, 95.4%) and the control group (80.0%, 75.4%, 83.1%) with the self-evaluation questionnaire (chi(2) = 13.246, 11.576, 16.204, all P < 0.01). The trend line of daily medication scores in weekly intervals showed a significant decline. The mean daily medication score of phase II (0.20 +/- 0.36) was significant lower than that of phase I (0.33 +/- 0.67, Z = 3.344, P < 0.01), whereas the control group did not show a significant difference between phase II (0.35 +/- 0.96) and phase I (0.32 +/- 0.95, Z = 0.744, P > 0.05). After 1-year treatment, no significant differences were found in morning and evening peak expiratory flow of predicted value (PEF%), forced expiratory volume in one second of predicted value (FEV(1)/FVC), forced vital capacity of predicted value (FVC%), forced expiratory volume in one second to forced vital capacity ratio (FEV(1)/FVC), provoking dose decreasing FEV(1) by 20% (PD(20)-FEV(1)) between the active group [(97 +/- 17)%, (98 +/- 18)%, (91 +/- 11)%, (98 +/- 9)%, (82 +/- 10)%, 2.35 (7.9) micromol] and the control group [(99 +/- 19)%, (100 +/- 19)%, (90 +/- 14)%, (99 +/- 13)%, (82 +/- 9)%, 1.80 (7.8) micromol] (t = 0.170 - 0.630, Z = 0.264, all P > 0.05). Skin index (SI) to Der p in the active group (1.2 +/- 0.5) was significantly lower than that of the control group (1.5 +/- 0.6) after treatment (t = 2.395, P < 0.05). There was no significant difference in the level of serum sIgE against Der p between groups, which was 76.80 (97.0) kU/L in active group and 66.50 (99.3) kU/L in the control group (Z = 0.232, P > 0.05). The frequency of systemic adverse reactions graded by guidelines based on the position paper of European Academy of Allergology and Clinical Immunology (EAACI), was 5.7% and 1.8% of the total injections in the active group and the control group, respectively. Although significant difference was found in adverse reactions between groups (chi(2) = 4.705, P < 0.05), all were mild or moderate. The majority occurred within 30 minute after injection and were controlled well with symptomatic therapy. No any severe systemic adverse reaction was shown in the study. CONCLUSION: One year specific immunotherapy with standardized house dust mite (HDM) vaccine significantly improved symptoms and reduced medication use in mild to moderate allergic asthmatic patients. SIT also reduced skin prick test reactivity to Der p. Complying with the EAACI immunotherapy guidelines, SIT with standardized HDM vaccine was a safe treatment.

Adolescent↗
PubMed2006

[Expression of pituitary tumor-transforming gene in patients with multiple myeloma].

To explore the expression of pituitary tumor-transforming gene (PTTG) in elderly patients with multiple myeloma (MM) and its relationship with MM, the expressions of PTTG mRNA were detected in bone marrow mononuclear cells (BMMNC) from 33 patients with MM and 10 normal controls by using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the expression of PTTG mRNA in MM patients (0.3415 +/- 0.2172) was significantly higher than that in normal controls (0.0590 +/- 0.0233) (P < 0.05). It is concluded that the overexpression of oncogene PTTG may be related to genesis and progression of MM. It provided a new ideas to study the pathogenesis and gene therapy for MM patients.

Aged↗
PubMed2006

[Bone marrow mesenchymal cell transplantation reduces left ventricular remodeling in heart failure following acute myocardial infarction].

OBJECTIVE: Bone marrow mesenchymal cell (MSC) transplantation has been shown to improve heart failure but the mechanism and the subsequent effects are unclear. We tested the hypothesis that MSC transplantation reduces left ventricular remodeling through the MMP/TIMP system in heart failure following acute myocardial infarction. METHODS: Female SD rats underwent coronary artery ligation to induce myocardial infarction. Four weeks later, the rats were divided into the test group (n = 7) and the control group (n = 7), respectively. The donor MSCs were harvested and expanded from male SD rats (5 x 10(6) in 50 microl PBS) and injected into the ischemic myocardium, while the control group received the same volume of PBS. Left ventricular morphology was then evaluated in both groups through staining with H&E and Masson's trichrome. Immunohistochemical staining was used to examine the expressions of MMP2 and TIMP1, as well as type I and type III collagens, in the scar zones. The protein levels of MMP2 and TIMP1 were determined by Western blotting. RESULTS: MSC differentiated into fibroblast-like cells at 21 days after transplantation in the test group. In addition, many inflammatory cells infiltrated and aggregated in the scar area, but this effect was reduced at day 7 after transplantation. The following changes were noted in the test group compared to the control group: ejection fraction and shortening fraction were higher [(63.43 +/- 3.97)% vs. (36.20 +/- 3.99)%, (31.71 +/- 1.98)% vs. (18.00 +/- 2.07)%, P < 0.05]; dp/dt(min) was reduced [(-4756.24 +/- 270.00) mm Hg/s vs. -2789.53 +/- 624.13) mm Hg/s, P < 0.05]; the left ventricular thinning ratio was significantly higher [(76.34 +/- 2.66)% vs. (64.37 +/- 2.36)%, P < 0.05]; the infarct size was smaller [(36.19 +/- 0.83)% vs. (42.12 +/- 1.88)%, P < 0.05]; type I collagen expression in the scar area was much higher; type III collagen expression was much lower; MMP2 expression was reduced and TIMP1 expression was increased. CONCLUSION: MSC transplantation led to dynamic changes in the collagen network through regulation of MMP2/TIMP1 system and consequently interrupted the progress of adverse LV remodeling in heart failure following acute myocardial infarction.

Animals↗
PubMed2006

[Amniotic membrane as a carrier for cultivated and labeled corneal endothelial cell transplantation].

OBJECTIVE: To investigate the feasibility of using amniotic membrane (AM) as a carrier for cultured corneal endothelial cells transplantation. METHODS: Rabbit corneal endothelial cells were cultivated, passaged, and labeled with the fluorescent tracker CM-DiI, then transplanted onto denuded AM. The cell density, morphology, histology and ultrastructure of the cultured cells on AM were examined by light microscope, fluorescent microscopy and scanning electron microscope. To determine whether these composite endothelial sheets were functional in vivo, the sheets were transplanted onto rabbit corneas whose deep lamellar with Descemet's membrane and endothelial cells had been completely removed. The deep layer excised rabbit corneas without any transplantation or with transplantation of denuded AM were treated as controls. After transplantation, the corneal appearance and corneal thickness were examined. The grafts were examined for cell density, morphology and histology 4 weeks after the surgery. RESULTS: A monolayer of endothelial cells were confluent on the AM 5 - 7 days after seeding. The density of the endothelial cells was (3202.84 +/- 347.77)/mm(2). Morphologically, the sheets consisted of a fairly continuous layer of flat polygonal endothelial cells that appeared uniform in size with tight junctions. The labeled cells were red in color under fluorescent microscopy. After transplantation, the corneas that received cultured endothelial cells had little edema and retained their thinness and transparency, while the corneas of controls showed prominent edema and opacity, indicating that these cells were transplanted cells rather than the cells migrated from peripheral cornea. Four weeks after surgery, the labeled endothelial cells were still found in the cornea with red fluorescence. CONCLUSIONS: AM maintains cultured endothelial cells' morphology and function both in vitro and in vivo. AM could serve as a carrier for corneal endothelial cells transplantation. These results provide a promising method for the treatment of diseases caused by corneal endothelial disorders.

Amnion↗
PubMed2005

Core/shell quantum-dot-photosensitized nano-TiO2 films: fabrication and application to the damage of cells and DNA.

Through the use of monodisperse core/shell quantum dots (QDs) as photosensitizers for the first time, a novel strategy for the fabrication of QD-photosensitized nano-TiO2 films was demonstrated. Core/shell QDs were self-assembled on nano-TiO2 films through carboxyls as anchoring groups to metal oxides. Atomic force microscopy and some other experiments showed the fabrication strategy is successful. Reactive oxygen species detection experiments indicated that such films have photosensitization ability. The results of bactericidal and DNA damage experiments demonstrate that such films have excellent photoactivity.

DNA↗
PubMed2005

ISL1 physically interacts with BETA2 to promote insulin gene transcriptional synergy in non-beta cells.

ISL1 is a LIM homeodomain protein that plays an important role in insulin gene transcriptional activation and islet cell formation. BETA2 is a transcription factor in the basic helix-loop-helix (bHLH) family, which activates expression of tissue-specific genes in several developmental systems. In this study, we investigated the functional and physical interactions of ISL1 and BETA2 in promoting insulin gene transcription in non-beta cells. Using the luciferase assay, we demonstrated that ISL1 and BETA2 could activate insulin gene transcription synergistically. Co-immunoprecipitation also supported that ISL1 and BETA2 appear in one complex and this physical interaction mediates the synergy between these two proteins.

Basic Helix-Loop-Helix Proteins↗
PubMed2005

Gap junction-mediated intercellular biochemical coupling in cochlear supporting cells is required for normal cochlear functions.

Dysfunction of gap junctions (GJs) caused by mutations in connexin26 (Cx26) and Cx30 accounts for nearly half of all cases of hereditary nonsyndromic deafness cases. Although it is widely held that GJs connecting supporting cells in the organ of Corti mainly provide ionic pathways for rapid removal of K+ around the base of hair cells, the function of GJs in the cochlea remains unknown. Here we show that GJs were not assembled in the supporting cells of the organ of Corti until 3 days after birth in mice and then gradually matured to connect supporting cells before the onset of hearing. In organotypic cochlear cultures that were confirmed to express GJs, GJs mediated the propagation of intracellular Ca2+ concentration waves in supporting cells by allowing intercellular diffusion of inositol 1,4,5-trisphosphate. We found that a subset of structurally mild Cx26 mutations located at the second transmembrane region (V84L, V95M, and A88S) and a Cx30 mutation located at the first cytoplasmic segment (T5M) specifically affect the intercellular exchange of larger molecules but leave the ionic permeability intact. Our results indicated that Cx26 and Cx30 mutations that are linked to sensorineural deafness retained ionic coupling but were deficient in biochemical permeability. Therefore, GJ-mediated intercellular exchange of biochemically important molecules is required for normal cochlear functions.

Animals↗
PubMed2005

MRS algorithm: a new method for searching myocardial region in SPECT myocardial perfusion images.

First, the necessity of automatically segmenting myocardium from myocardial SPECT image is discussed in Section 1. To eliminate the influence of the background, the optimal threshold segmentation method modified for the MRS algorithm is explained in Section 2. Then, the image erosion structure is applied to identify the myocardium region and the liver region. The contour tracing method is introduced to extract the myocardial contour. To locate the centriod of the myocardium, the myocardial centriod searching method is developed. The protocol of the MRS algorithm is summarized in Section 6. The performance of the MRS algorithm is investigated and the conclusion is drawn in Section 7. Finally, the importance of the MRS algorithm and the improvement of the MRS algorithm are discussed.

Algorithms↗
PubMed2005

Identification of a new antitubercular drug candidate, SQ109, from a combinatorial library of 1,2-ethylenediamines.

OBJECTIVES: The aim of this study was to identify a candidate drug for clinical development from a previously synthesized combinatorial library based on the 1,2-ethylenediamine structure of ethambutol. METHODS: Sixty-nine of the most potent hits against Mycobacterium tuberculosis from the original studies were subjected to a sequential set of tests in vitro and in vivo--determination of MIC for M. tuberculosis H37Rv, cytotoxicity, intracellular antimycobacterial activity, permeability evaluation and in vivo efficacy testing. RESULTS: Twenty-seven compounds with MICs of < or = 15.6 microM were tested on Vero cells to determine in vitro cytotoxicity (IC50) and to establish a selectivity index (SI) (SI = IC50/MIC). Ten compounds with acceptable SI were tested for activity against intracellular bacteria--all were equivalent (within 1%) or superior to ethambutol and several demonstrated cidal activity. Five of the most potent compounds were tested for in vivo efficacy in a murine model of chronic tuberculosis infection. CONCLUSION: Compound SQ109 with an MIC of 0.7-1.56 microM (H37Rv, Erdman and drug-resistant strains of M. tuberculosis), an SI of 16.7 and 99% inhibition activity against intracellular bacteria, demonstrated potency in vivo and limited toxicity in vitro and in vivo, and was selected for further development.

Animals↗
PubMed2005

Regulation of polarized extension and planar cell polarity in the cochlea by the vertebrate PCP pathway.

The mammalian auditory sensory organ, the organ of Corti, consists of sensory hair cells with uniformly oriented stereocilia on the apical surfaces and has a distinct planar cell polarity (PCP) parallel to the sensory epithelium. It is not certain how this polarity is achieved during differentiation. Here we show that the organ of Corti is formed from a thicker and shorter postmitotic primordium through unidirectional extension, characteristic of cellular intercalation known as convergent extension. Mutations in the PCP pathway interfere with this extension, resulting a shorter and wider cochlea as well as misorientation of stereocilia. Furthermore, parallel to the homologous pathway in Drosophila melanogaster, a mammalian PCP component Dishevelled2 shows PCP-dependent polarized subcellular localization across the organ of Corti. Taken together, these data suggest that there is a conserved molecular mechanism for PCP pathways in invertebrates and vertebrates and indicate that the mammalian PCP pathway might directly couple cellular intercalations to PCP establishment in the cochlea.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Mutations of connexin43 in fetuses with congenital heart malformations.

BACKGROUND: Gap junction channels formed by connexin43 (Cx43) protein are important in cardiac morphogenesis, and Cx43 gene is thought to be associated with congenital heart malformation (CHM). This study was undertaken to detect the mutations of Cx43 in fetuses with CHM. METHODS: Cx43 extron DNA was amplified by PCR from 16 fetuses with a variety of CHM. The PCR products were analyzed by SSCP and DNA sequencing. Thirty children who had no CHM were selected as controls. RESULTS: Eight homozygous mutations of Cx43 were observed in a fetus with double outlet right ventricule (DORV), five of the 8 mutations were missense mutations including Arg239Trp, Ser251Thr, Ala253Pro, Pro283Leu and Thr290Asn, and the remaining 3 were silent polymorphisms including Gly252Gly, Pro256Pro and Thr275Thr. No mutations were found in other fetuses and the control group. CONCLUSIONS: Mutations of Cx43 may be associated with congenital conotruncal anomalies. PCR-SSCP is an effective method for screening the mutations of Cx43.

Connexin 43↗
PubMed2005

Relationship between proliferative activity of cancer cells and clinicopathological factors in patients with esophageal squamous cell carcinoma.

AIM: To assess whether the molecular markers of malignant tumors could improve the understanding of tumor characteristics, and to observe the characteristics of expression of cell cycle markers Ki-67 and cyclin A in esophageal carcinoma and to analyze the relationship between proliferative activity of cancer cells and clinicopathological factors. METHODS: Seventy of surgically resected esophageal squamous cell carcinoma (SCC) were examined by immunohistochemistry utilizing commercially available antibodies. Nuclear staining was regarded as a positive result. At least 50 fields in each tumor and non-tumor section were evaluated at a medium power (X200) to determine the proportion of tumor cells and the staining intensity of nuclei in the entire sections. RESULTS: Ki-67 and cyclin A were only expressed in base cells of normal esophageal mucosa. The positive immuno-staining of nuclei of SCC was significantly higher than that in normal esophageal mucosa (t=13.32 and t=7.52, respectively, P<0.01). The distribution of positively stained was more diffuse and stronger in poorly differentiated SCC. Both Ki-67 and cyclin A expressions were related to histological grades of tumors (t=3.5675 and t=3.916; t=2.13, respectively, P<0.05) but not to the sex and age of the patients, tumor size, lymphatic invasion, location, or stage grouping. CONCLUSION: The proliferative activity of cancer cells may be understood by immunohistochemistry of Ki-67 and cyclin A in Chinese patients with esophageal SCC. These cell cycle markers may serve as an indicator of cancer cell proliferation rate. The overexpression of cell cycle markers Ki-67 and cyclin A suggests the poor SCC differentiation in patients with esophageal carcinoma.

Biomarkers, Tumor↗
PubMed2005

A novel anti-platelet monoclonal antibody (3C7) specific for the complex of integrin alpha IIb beta3 inhibits platelet aggregation and adhesion.

Activation or ligand binding induces conformational changes in alpha IIb beta3, resulting in exposure of neoepitopes named ligand-induced binding sites. We reported here a novel monoclonal antibody developed by using Chinese hamster ovary (CHO) cells expressing an activated alpha IIb beta3 mutant (CHO alpha IIb beta3Delta717) as the immunogen. This IgG 2b kappa named 3C7 was specific for the complex of alpha IIb beta3 as demonstrated by flow cytometry, immunoprecipitation, and EDTA chelating. The binding of 3C7 to platelets increased significantly when platelets were activated by ADP/thrombin or occupied by RGDS peptides, fibrinogen, or PAC-1, suggesting that 3C7 was an anti-ligand-induced binding site antibody. The antibody failed to bind to the CHO cells expressing another alpha IIb beta3 mutant (beta3Y178A) suggesting that the Cys177-Cys184 loop of beta3 was likely the epitope for 3C7. 3C7 inhibited platelet aggregation, which was initiated by ADP or thrombin in a dose-dependent manner (IC50s of 5.6 and 0.05 microg/ml, respectively). The antibody also inhibited platelet adhesion to immobilized fibrinogen but not to fibronectin or collagen. These findings suggested that 3C7 was a potent antagonist of integrin alpha IIb beta3 and a potential anti-thrombotic agent.

Adenosine Diphosphate↗
PubMed2005

Heterogeneity in predisposition of hepatic cells to be induced into pancreatic endocrine cells by PDX-1.

AIM: The role of Pancreatic and Duodenal Homeobox-1 (PDX-1) as a major regulator of pancreatic development determines the function and phenotype of beta cell. In this study, potential plasticity of liver cells into pancreatic endocrine cells induced by PDX-1 was evaluated. METHODS: Human hepatoma cell line HepG2 was stably transfected with mammalian expression plasmid pcDNA3-PDX encoding human PDX-1 gene. Ectopic expression of PDX-1 and insulin were detected by RT-PCR, Western blot and/or immunostaining. PDX-1(+) HepG2 cells were transplanted under renal capsule of STZ-induced diabetic nude mice (n = 16) to examine the inducing effect in vivo. RESULTS: Exogenous PDX-1 transgene was proved to express effectively in HepG2 cell at both mRNA and protein levels. The expression of endogenous insulin and some beta cell-specific differentiation markers and transcription factors were not induced in PDX-1(+) HepG2 cells. When transplanted under renal capsule of STZ-induced diabetic nude mice, PDX-1(+) HepG2 cells did not generate insulin-producing cells. These data indicated that stable transfected PDX-1 could not convert hepatoma cell line HepG2 to pancreatic cells in vitro or in vivo. Mature hepatocytes might need much more complicated or rigorous conditions to be shifted to insulin-producing cells. CONCLUSION: The expression of exogenous PDX-1 is not sufficient to induce relatively mature hepatocytes differentiating into insulin-producing cells.

Animals↗
PubMed2005

Atorvastatin reduces lipopolysaccharide-induced expression of cyclooxygenase-2 in human pulmonary epithelial cells.

OBJECTIVE: To explore the effects of atorvastatin on expression of cyclooxygenase-2 (COX-2) in human pulmonary epithelial cells (A549). METHODS: A549 cells were incubated in DMEM medium containing lipopolysaccharide (LPS) in the presence or absence of atorvastatin. After incubation, the medium was collected and the amount of prostaglandin E2 (PGE2) was measured by enzyme-linked immunosorbent assay (ELISA). The cells were harvested, and COX-2 mRNA and protein were analyzed by RT-PCR and western-blot respectively. RESULTS: LPS increased the expression of COX-2 mRNA and production of PGE2 in a dose- and time-dependent manner in A549. Induction of COX-2 mRNA and protein by LPS were inhibited by atorvastatin in a dose-dependent manner. Atorvastatin also significantly decreased LPS-induced production of PGE2. There was a positive correlation between reduced of COX-2 mRNA and decreased of PGE2 (r = 0.947, P < 0.05). CONCLUSION: Atorvastatin down-regulates LPS-induced expression of the COX-2 and consequently inhibits production of PGE2 in cultured A549 cells.

Atorvastatin↗
PubMed2005

Characteristics of trapping various organophosphorus pesticides with a ferritin reactor of shark liver (Sphyrna zygaena).

A reactor is composed of liver ferritin of Sphyrna zygaena (SZLF) and an oscillating bag. A reactive procedure for trapping various organphosphorus pesticides (OPs) with the SZLF reactor in the flowing water is described in detail, showing the maximal trapping numbers of 28 +/-1.0 dichlorovos/SZLF, 42 +/- 1.0 dimethoate/SZLF, and 55 +/- 1.0 methamido-phos/SZLF determined by a improved spectrophotometric method in 12 h. In addition, it is found that the OP numbers trapped by the reactor increase along with the incubation time and its concentration increment in the flowing water (or seawater), respectively. This trapping capacity is considered to depend on the composition of amino acids on the surface of the ferritin shell interior rather than the available volume within the shell. A novel pathway for trapping various OPs with the ferritin is suggested in reference to unstable characteristics of the protein subunits. We claim that the ferritin reactor will be employed to monitor the contamination level of various OPs in the flowing water continuously.

Animals↗