肝癌组织中脱-γ-羧基凝血酶原的测定及意义

目的:定量分析癌组织和非癌组织脱-γ-羧基凝血酶原(DCP)的浓度,探讨它们在血清DCP升高的作用及临床意义.方法:用电化学发光免疫分析法(ECLIA)定量测定41例肝癌患者血清、癌组织和非癌组织中DCP的含量.结果:癌组织DCP浓度平均为84447.7(7.1-2098623.7)mAU/g,非癌组织DCP浓度平均为888.1(0-23299.2)mAU/g.细胞膜上的DCP浓度明显高于细胞质中DCP浓度(P<0.001),癌组织DCP浓度明显高于非癌组织(4926.5vs195.2mAU/g,P<0.001).血清DCP浓度对数与癌组织DCP浓度对数(P=0.019)、非癌组织DCP浓度对数(P=0.020)均存在明显相关性,癌组织DCP浓度对数和非癌组织DCP浓度对数间也存在相关性(P=0.011).HCV感染的肝癌组癌组织和非癌组织DCP浓度均明显高于HCV感染阴性的肝癌组(6336.6vs1799.1mAU/g,248.0vs102.5mAU/g,P<0.05).门脉浸润的肝癌组癌组织DCP浓度明显高于没有门脉浸润的肝癌组(P=0.028),而肝静脉浸润组癌组织DCP浓度明显低于无肝静脉浸润组(P=0.042).伴有肝内转移的肝癌组非癌组织DCP浓度明显高于无肝内转移的肝癌组(P=0.023).结论:癌组织产生过量DCP是肝癌血清DCP的主要来源,是一预后标志物,但肝癌血清DCP浓度是癌组织和非癌组织产生DCP浓度的整体表现.

测定血清层粘蛋白和透明质酸对诊断肝纤维化的探讨

层粘蛋白（ＬＮ）和透明质酸（ＨＡ）代谢失衡可致肝纤维化；两者血清含量可反映病变程度。该文作者应用ＲＩＡ法检测１５６例肝病和４２例健康者血清ＬＮ和ＨＡ。结果显示：急性肝病组血清ＬＮ和ＨＡ与对照组差异无显著性；ＣＰＨ组两项指标轻度增高；ＣＡＨ组测定值更高；ＬＣ组ＬＮ和ＨＡ测定值最高，分别为对照组的２．５倍和９．５倍（Ｐ＜０．００１）。按Ｃｈｉｌｄ－ｐｕｇｈ分级，ＬＮ和ＨＡ测定值在肝硬化Ａ、Ｂ和Ｃ级间呈递增趋势，且与总胆红素呈正相关（γ＝０．８４，０．５７），与白蛋白呈负相关（γ＝－０．９２，－０．９５）。作者认为：ＬＮ与ＨＡ对诊断肝纤维化有肯定价值，它们测定值的动态观察有助于反映肝硬化患者肝功能损害的程度及病程演变，还可用于对治疗效果的判定。

Human bocavirus: Current knowledge and future challenges

Human bocavirus(HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool samples, from patients with gastroenteritis. Since then, other viruses related to the first HBoV isolate(HBoV 1), namely HBoV 2, HBoV 3 and HBoV 4, have been detected principally in human faeces. HBo Vs are small nonenveloped single-stranded DNA viruses of about 5300 nucleotides, consisting of three open reading frames encoding the first two the non-structural protein 1(NS1) and nuclear phosphoprotein(NP1) and the third the viral capsid proteins 1 and 2(VP1 and VP2). HBoV pathogenicity remains to be fully clarified mainly due to the lack of animal models for the difficulties in replicating the virus in in vitro cell cultures, and the fact that HBo V infection is frequently accompanied by at least another viral and/or bacterial respiratory and/or gastroenteric pathogen infection. Current diagnostic methods to support HBoV detection include polymerase chain reaction, real-time PCR, enzymelinked immunosorbent assay and enzyme immunoassay using recombinant VP2 or virus-like particle capsid proteins, although sequence-independent amplification techniques combined with next-generation sequencing platforms promise rapid and simultaneous detection of the pathogens in the future. This review presents the current knowledge on HBoV genotypes with emphasis on taxonomy, phylogenetic relationship and genomic analysis, biology, epidemiology, pathogenesis and diagnostic methods. The emerging discussion on HBoV s as true pathogen or innocent bystander is also emphasized.

Observation of Insulin Exocytosis by a Pancreatic β Cell Line with Total Internal Reflection Fluorescence Microscopy

INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence （TIRF） microscopy has been employed to study insulin secretion.

False Human Immunodeficiency Virus Test Results Associated with Rheumatoid Factors in Rheumatoid Arthritis

Objective To investigate if immunological factors associated with rheumatoid arthritis(RA) affect the result of human immunodeficiency virus(HIV) screening by electrochemiluminescence immunoassay(ECLIA) and enzyme-linked immunosorbent assay(ELISA). Methods 100 RA cases were enrolled from January 2012 to February 2013 into this study. HIV screening was conducted with ECLIA detecting both HIV-1 p24 antigen, HIV-1 and HIV-2 antibodies, with ELISA and colloidal gold method detecting HIV-1 and HIV-2 antibodies. The samples producing positive results were submitted to the Center for Disease Control for confirmation using Western blotting method. The antibody titers of rheumatoid factors(RF) including RF-IgG, RF-IgM, RF-IgA, and CCP-IgG were analyzed by ELISA. Results The HIV positive-rate determined by ECLIA was significantly higher than that by ELISA and colloidal gold method(P<0.01). The false-positive rate of HIV screening was associated with antibody titers of RF-IgG, RF-IgM, RF-IgA, and CCP-IgG in RA(P<0.01). Conclusion Immunological factors, including RF and anti-CCP antibody, may influence the screening of HIV by ECLIA, producing false-positive result.

Assay of ghrelin concentration in infant formulas and breast milk

AIM: To test if total ghrelin is present in infant formulas. METHODS: Using a radioimmunoassay, we measured total ghrelin concentrations in 19 samples of commercial infant formulas and in 20 samples of human milk. We also determined ghrelin concentration in the serum of infants and lactating mothers. RESULTS: Ghrelin concentrations were significantly higher in artificial milk (2007.1 ± 1725.36 pg/mL) than in human milk (828.17 ± 323.32 pg/mL) (P = 0.005). The mean ghrelin concentration in infant serum (n = 56) was 1115.86 ± 42.89 pg/mL, and was significantly higher (P = 0.023) in formula-fed infants (1247.93 ± 328.07 pg/mL) than in breast-fed infants (1045.7 ± 263.38 pg/mL). The mean serum ghrelin concentration (mean ± SD) in lactating mothers (n = 20) was 1319.18 ± 140.18 pg/mL. CONCLUSION: This study provides evidence that total ghrelin is present in infant formulas. This findingraises diverse questions regarding the uptake, absorption and metabolic effects of this hormone.

Expression and significance of homeodomain protein Cdx2 in gastric carcinoma and precancerous lesions

AIM： To investigate the expression and significance of caudal-related homeobox transcription factor （Cdx2） in gastric carcinoma （GC） and precancerous lesions. METHODS： The expression of Cdx2 in GC, precancer- ous lesions and normal gastric mucosa were detected using immunohistochemical method. Hematoxylin and eosin staining, alcian blue/periodic acid-schiff and high iron diamine/alcian blue staining were used to classify intestinal metaplasia （IM） and GC. RESULTS： Cdx2 was not detected in normal gas- tric mucosa. Cdx2 expression was detected in 87.1% （101/116） of IM, 50% （36/72） of dysplasia and 48.2% （41/85） of GC. The Cdx2-expressing cells in IM were more prevalent than in dysplasia and carcinoma （P 〈 0.05）. There was no relationship between Cdx2 ex- pression and the classification of IM or the degree of dysplasia. Expression of Cdx2 was significantly higher in intestinal-type carcinoma than in diffuse and mixed- type carcinoma （P 〈 0.05）. Positive expression of Cdx2was mainly found in moderately to well differentiated GC. There was a negative association between nuclear Cdx2 expression and lymph node metastasis and tumor, nodes, metastasis stage of GC （P 〈 0.05）. The patients with Cdx2-positive expression showed a higher survival rate than those with Cdx2-negative expression （P = 0.038）. Multivariate analysis revealed that the expres- sion of Cdx2 and lymph node metastasis were indepen- dent prognostic indicators of GC （P 〈 0.05）.

T-cell ageing in end-stage renal disease patients:Assessment and clinical relevance

End-stage renal disease （ESRD） patients have a defec-tive T-cell-mediated immune system which is related to excessive premature ageing of the T-cell compartment. This is likely to be caused by the uremia-associated pro-infammatory milieu, created by loss of renal func-tion. Therefore, ESRD patients are highly susceptible for infections, have an increased risk for virus-associated cancers, respond poorly to vaccination and have an increased risk for atherosclerotic diseases. Three ageing parameters can be used to assess an immu-nological T-cell age. First, thymic output can be deter-mined by assessing the T-cell receptor excision circles-content together with CD31 expression within the na？ve T cells. Second, the telomere length of T cells and third the T-cell differentiation status are also indicators of T-cell ageing. Analyses based on these parameters in ESRD patients revealed that the immunological T-cell age is increased by on average 20 years compared to the chronological age. After kidney transplantation （KTx） the aged T-cell phenotype persists although the pro-inflammatory milieu is diminished. This might be explained by epigenetic modifcations at hematopoietic stem cells level. Assessment of an immunological T-cell age could be an important tool to identify KTx recipi-ents who are at risk for allograft rejection or to prevent over-immunosuppression.

A self region based real-valued negative selection algorithm

Point-wise negative selection algorithms,which generate their detector sets based on point of self data,have lower training efficiency and detection rate.To solve this problem,a self region based real-valued negative selection algorithm is presented.In this new approach,the continuous self region is defined by the collection of self data,the partial training takes place at the training stage according to both the radius of self region and the cosine distance between gravity of the self region and detector candidate,and variable detectors in the self region are deployed.The algorithm is tested using the triangle shape of self region in the 2-D complement space and KDD CUP 1999 data set.Results show that,more information can be provided when the training self points are used together as a whole,and compared with the point-wise negative selection algorithm,the new approach can improve the training efficiency of system and the detection rate significantly.

Safety and Efficacy of Digoxin TherapymWhere Are We Now？

The aim of our study was to determine the criteria and key factors for the effectiveness of digoxin therapy. A prospective opened-type study was carried out in conditions of everyday clinical practice. The concentrations of digoxin were quantified from blood samples taken following the achievement of drug steady-state （using AxSYM microparticle enzyme immunoassay-MEIA）. The risk/benefit ratio was evaluated based upon the correlation between measured blood concentrations of the drug and clinical response. Study results （100 decompensated patients） revealed that therapy indication field was correctly covered, showing a higher prevalence in elderly. On average, each examinee had 2 or 3 comorbidities. Applied daily dose of digoxin ranged from 0.053 mg to 0.25 mg. Renal function was assessed by creatinine clearance which is one of the key factors for the accomplishment of optimal digoxin serum concentrations （p 〈 0.05）. Co-administration of seven drugs was complicating factor for the management of rational therapy. 76/100 patients were within referent range （0.8-2.0 ng/mL）, while 13/100 were above the upper limit. Four side effects in total were recorded （nausea, vomiting, confusion）, whereas in only two patients digoxin was excluded from the therapy. Digoxin confirmed the justifiability of its use in contemporary clinical practice.

Expression of Endogenous Retrovirus ev/J gp85 Gene and Analysis of Its Immunoreactivity in Comparison with Exogenous Viral Protein

The envelope gene gp85 of ev/J, a new family of endogenous avian retroviral sequences identified recently, has the most extensive nucleotide sequence identity ever described with ALV-J avian leukosis virus. This report described expression of ev/J envelope gene gp85 derived from commercial meat-type chicken using the Invitrogen Bac-to-Bac baculovirus expression system. The antigenicity and immunoreactivity of the recombinant endogenous gp85 gene product (SU) were analyzed by indirect immunofluorescence, Western blot, indirect and blocking Enzyme-Linked ImmunoSorbent Assay (ELISA) using JE9 monoclonal antibody (MAb) against the envelope protein of ALV-J (ADOL-4817), positive mouse antiserum against the ev/J gp85 SU and sera from chicken naturally infected with ALV-J. The results showed that the ev/J gp85 SU can bind specifically to JE9 MAb and antiserum from chicken naturally infected with ALV-J, and the binding reactivity between exogenous ALV-J gp85 SU and natural positive chicken serum against exogenous ALV-J can be blocked by positive mouse serum against the ev/J gp85 SU. It is concluded that recombinant endogenous gp85 gene product (SU) has close immunological relatedness to the envelope protein of exogenous ALV-J (ADOL-4817 and IMC10200 strain).

Orthotopic heart transplantation with prolonged donor ischemic time:report of 3 cases and literature review

Heart transplantation has become an effective therapy for patients with end stage heart failure. The preservation of the donor heart is an important factor that affects the results of the operation. We performed 3 cases of orthotopic heart transplantation and obtained some experience in the preservation of the donor heart. Methods： Three male patients with end stage heart failure received the operation in our department successfully. Doppler echocardiography showed left ventrieular end diameter （LVED） of the patients were 91, 87, and 83 mm, and ejection fraction （EF） were 24%, 20%, 12.9%, respectively. Once the declaration of brain death had been made, the median stemotomy was performed with a sternal saw. Haparin at a dose of 300 U/kg of body weight was administered. After at least 2-min heparin circulation, the procurement proceeded. The superior vena cava and the inferior vena cava were nearly completely divided. When the heart was empty, the ascending aorta was cross-clamped and the St. Thomas solution was infused by gravity. The heart was excised by transection of the inferior vena cava, the superior vena cava and all pulmonary veins. After donor heart was removed, it was infused with University of Wisconsin （UW） solution by gravity at a temperature of 4-6℃, then placed in UW solution for storage during transportation. The temperature of solution was maintained at about 4-6℃. The ischemic times of donor heart were 9, 8 and 6 h, respectively. The bicaval anastomotic heart transplantation was adopted. The left atrial anastomoses were constructed using 3.0 polypropylene. The inferior vene cava anastomosis was constructed, the donor and native aorta were cut to an appropriate length. Then the aorta and main pulmonary artery anastomosis were performed respectively. The superior vene cava anastomosis was usually constructed during the rewarming phase. The intraoperative course with a cardiopulmonary bypass of the 3 patients was 96, 44 and 49 min, respectively. Standard triple immunosuppression therapy was commenced in the immediate post-operative period. Results： The operation procedure was smooth and no perioperative death occurred. The follow-up was carried out carefully. The patient＇s condition was fine in 25, 30 and 32 months after operation. The blood pressure was 130/90, 140/95 and 120/80 mmHg, respectively, and LVED was 51, 49 and 53 mm; EF was 50%, 54% and 60%, respectively. Cardiothoracic ratio was 0.63, 0.55, and 0.64, respectively. Conclusion： Preservation time of donor heart with St. Thomas solution infusion and UW solution storage at 0-4℃ may exceed 6 h, and receive comparable middle-term outcomes.

Kidney regeneration: Where we are and future perspectives

In 2012, about 16487 people received kidney transplants in the United States, whereas 95022 candidates were on the waiting list by the end of the year. Despite advances in renal transplant immunology, approximately 40% of recipients will die or lose graft within 10 years. The limitations of current therapies for renal failure have led researchers to explore the development of modalities that could improve, restore, or replace the renal function. The aim of this paper is to describe a reasonable approach for kidney regeneration and review the current literature regarding cell sources and mechanisms to develop a bioengineering kidney. Due to kidneys peculiar anatomy, extracellular matrix based scaffolds are rational starting point for their regeneration. The perfusion of detergents through the kidney vasculature is an effcient method for delivering decel-lularizing agents to cells and for removing of cellular material from the tissue. Many efforts have focused on the search of a reliable cell source to provide enrichment for achieving stable renal cell systems. For an effcient bioengineered kidney, these cells must be attached to the organ and then maturated into the bio-ractors, which simulates the human body environment.A functional bioengineered kidney is still a big challenge for scientists. In the last ten years we have got many improvements on the feld of solid organ regeneration; however, we are still far away from the main target. Currently, regenerative centers worldwide have been striving to find feasible strategies to develop bioengi-neered kidneys. Cell-scaffold technology gives hope to end-stage renal disease patients who struggle with morbidity and mortality due to extended periods on dialysis or immunosupression. The potential of bioengi-neered organ is to provide a reliable source of organs, which can be refunctionalized and transplanted.

Clinical Significance of CENP-H Expression in Uterine Cervical Cancer

Objective This work aims to investigate the expression pattern and clinicopathologic significance of centromere protein H(CENP-H) in uterine cervical cancer(UCC). Methods The level of CENP-H expression in the paraffin sections of 62 UCC cases was determined by the SP immunohistochemical method,with complete clinicopathologic data in all cases.Statistical analysis was conducted to evaluate the prognostic and diagnostic significance of CENP-H using SPSS13.0 software package. Results Immunohistochemical assay showed strong CENP-H expression in 61.29% (38/62) of the paraffin-embedded cervical cancer tissues.Statistical analysis revealed a strong correlation between the CENP-H expression and the clinical classification(P=0.038) of the cervical carcinoma.The expression increased with rise of the stages.The analysis of Cox proportional hazards regression model suggested that CENP-H expression(P=0.002) and tumor stage(P=0.001) were independent prognostic markers for the survival of UCC patients.The survival analysis showed that the survival rate was significantly lower in patients with high expression of CENP-H than in those with low expression of CENP-H(P=0.001). Conclusions CENP-H is likely to be a valuable marker for carcinogenesis and progression of UCC.It might be used as the important diagnostic and prognostic marker for cervical carcinoma patients,especially for those at early stage.

Screening and Primary Characterization of NewAntigen Genes of Schistosoma Japonicum

To find Schistosoma japonicum(S.j)new antigen gene thus provide more useful vaccine candidates, the cDNA library of S.j adult worm was screened with sera of rabbits immunized with the membrane antigens of Schistosoma japonicum hepato-portal schistosomula (SjHmAg). The positive clones were amplified by PCR and sequenced, then the sequences of clones were compared with all sequences in GenBank database using Blast process. The new clones were submitted to GenBank for accession numbers. Fifteen positive clones were obtained after three rounds of immunoscreening. The size of S.j cDNA fragments in positive clones ranged from 0.7?kb-3.0?kb after automatically excised with the helper phage. Sequence analysis revealed that partial sequence of clone M5 had significant homology with S.j mitochondria mRNA, the other positive clones were new S.j genes. M2 clone sequence (GenBank accession number AF502579) was 730?bp long it had a 117?bp open reading frame (ORF). The sequence of M15 (GenBank accession number AF502582) has no transmembrane region and encodes 92 amino acids, and its protein contains a ferredoxins iron-sulfur binding region signature and two VWFC signal regions. The size of M1、M8、M9、M12(GenBank accession numbers: AF502578, AF502580, AF500622, AF502581) ranges from 402?bp to 766?bp. It concluded that the sera from rabbit immunized with SjHmAg could recognize S.j specific antigens molecules, and these antigens may induce the protective immunity against S.j infection.

Interleukin-2 and Interleukin-6 in Recurrent Genital Herpes Patients

Objective:To study the cellular immunity status of patientswith recurrent genital herpes. Methods: Serum levels of interlukin-2 and its solublereceptor and interlukin-6 were measured by ELISA in 34patients with recurrent genital herpes. Results: Serum levels of IL-2 and IL-6 were significantlydecreased in patients compared to healthy controls (P<0.01),and the level of sIL-2R was significantly increased in patientswith recurrent genital herpes (P<0.01). There were nosignificant differences in all variables amongst patientsregarding relapse stage and remission stage (P>0.05). Conclusion: There was a cellular immune deficiency inpatients with recurrent genital herpes.

Bone Marrow Urokinase Plasminogen Activator Receptor Levels are Associated with the Progress of Multiple Myeloma

Objective To determine the mRNA and protein levels of urokinase plasminogen activator receptors(u PAR) in bone marrow fluid and bone marrow tissue from multiple myeloma(MM) patients and assess association of u PAR level with prognosis of MM.Methods u PAR levels in bone marrow fluid of 22 MM patients at the stable and progressive stages and 18 iron deficiency anemia patients with normal bone marrow(control) were examined by ELISA.Furthermore,u PAR expression in bone marrow tissue was investigated by RT-PCR and Western blot,respectively.The distribution of u PAR in MM cells was examined using immunofluorescence staining.The pathological changes in different stages of MM patients were studied by HE staining.Results u PAR level in bone marrow fluid of MM patients(1.52±0.32 μg/ml) was found to be higher than that in the control group(0.98±0.15 μg/ml).Interestingly,u PAR protein(0.686±0.075 vs.0.372±0.043,P<0.05) and m RNA(2.51±0.46 vs.4.46±1.15,P<0.05) expression levels of MM patients at the progressive stage were significantly higher than those at the stable stage.The expression of u PAR in MM bone marrow was confirmed by immunofluorescence staining.Moreover,HE staining revealed a great increased number of nucleated cells and severe impairment of hematopoietic function in the bone marrow of patients with progressive-stage myeloma.Conclusion Our study reveals that u PAR expression is positively correlated with the development and progress of MM.

Expression of VEGF-C and b-FGF in Lung Cancer and Its Relationship with Cancer Progress

Objective： to observe expression of vascular endothelial growth factor-C （VEGF-C） and alkaline fibroblast growth factor （b-FGF） in tissues of lung cancer, and its relationship with cancer metastasis.Methods： to adopt immunohistochemical methods, analysis of 60 cases of lung tissue expression of VEGF-C and b-FGF in the situation.Result： positive rates of VEGF-C and b-FGF in lung cancer are respectively 56.67% and 63.33%; expression of VEGF-C and b-FGF in lung cancer is not related to pathological grades, pathologic stages or ages of patients （P 〉 0.05）,but closely related to TNM stages and existence of lymph node metastasis （P 〈 0.01）. IMVD in center of lung cancer tissues is obviously higher than surrounding area, with significant differences （P 〈 0.01）. Conclusion： expression of VEGF-C and b-FGF is related to lung cancer progress.

Developing antibodies from cholinesterase derived from prokaryotic expression and testing their feasibility for detecting immunogen content in Daphnia magna

To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT GATGTG-3＇ and reverse primer 5＇-GYAAGTTRGCCCAATATCT-3＇. To express the gene, one sequence of the amplified DNA, which was able to encode a putative protein containing two conserved carboxylesterase domains, was connected to the prokaryotic expression vector PET-29a（＋）. The recombinant vector was transformed into Escherichia coil BL21（DE3）. Protein expression was induced by isopropy-D-thiogalactoside. The expressed ChE was used as an immunogen to immunize BALB/c mice. The obtained antibodies were tested for their specificity towards crude enzymes from species such as Alona milleri, Macrobrachium nipponense, Bombyx mori, Chironomus kiiensis, Apis mellifera, Eisenia foetida, Brachydanio rerio, and Xenopus laevis. Results indicated that the antibodies had specificity suitable for detecting ChE in Daphnia magna. A type of indirect and non-competitive enzyme-linked immunosorbent assay（IN-ELISA） was used to test the immunoreactive content of ChE（ChE-IR） in Daphina magna. The detection limit of the IN-ELISA was found to be 14.5 ng/ml at an antiserum dilution of 1：22 000. Results from tests on Daphnia magna exposed to sublethal concentrations of triazophos indicated a maximal induction of 57.2% in terms of ChE-IR on the second day after the animals were exposed to a concentration of 2.10 μg/L triazophos. Testing on animals acclimatized to a temperature of 16 °C indicated that ChE-IR was induced by 16.9% compared with the ChE-IR content detected at 21 °C, and the rate of induction was 25.6% at 10 °C. The IN-ELISA was also used to test the stability of ChE-IR in collected samples. Repeated freezing and thawing had no influence on the outcome of the test. All these results suggest that the polyclonal antibodies developed against the recombinant ChE are as efficient as those developed against the native ChE in detecting ChE content in Daphnia magna.

Gold nanolabels and enzymatic recycling dual amplification-based electrochemical immunosensor for the highly sensitive detection of carcinoembryonic antigen

A sensitive electrochemical immunoassay system for the detection of a protein tumor biomarker through a dual amplified strategy was reported. Firstly, this protocol involves in the electropolymerization of o-aminobenzoic acid (o-ABA) on a glass carbon electrode (GCE). Subsequently, capture anti-CEA (Abl) is covalently linked to poly(o-ABA) (PAB) film, via N-(3-dimethylamminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysulfosuccinimid sodium salt (NHS) activation of the carboxyl groups and surface blocking with ethanolamine. Later, the target, carcinoembryonic antigen (CEA), is sandwiched between an electrode surface confined Ab1 and the alkaline phosphatase-labeled signal anti-CEA antibodies conjugated with gold nanoparticles (Ab2-ALP-AuNP bioconjugates). The dual biocatalytic signal amplification for CEA monitoring is achieved by coupling the numerous enzymes loaded on the AuNPs with redox-recycling of the enzymatic products in the presence of the secondary enzyme and the corresponding substrate. The novel dramatic signal amplification strategy, exhibits a good linearity at the studied concentration range from 0.005 to 50 ng mL-1 towards CEA with a detection limit of 2 pg mL-1 (S/N=3). There is a 5-100-fold improvement in detection limit compared to other similar studies. The developed dual signal amplified strategy shows good selectivity, regeneration, stability and acceptable reproducibility. Therefore, the signal amplification approach holds great potential applications in detection of ultra-trace protein biomarkers.