Expression of glycoprotein 90K in human malignant pleural mesothelioma: correlation with patient survival

The expression of the tumour-associated glycoprotein 90K in patients with malignant pleural mesothelioma (MM) has not been described. This study used enzyme-linked immunoassay (ELISA) to measure 90K in pleural effusions (PEs) and sera from patients with MM (n=28), lung cancer (LC) (n=14) and benign pleural disease (BPD) (n=15). Immunohistochemistry was used to investigate 90K expression in MM and LC tissue sections. The expression of 90K was further evaluated in vitro by ELISA and western blot analysis of conditioned media and cellular extracts of MM, LC and normal human mesothelial (NHM) cell cultures. Finally, the relationships between 90K expression in MM and patient age and survival were studied. The mean 90K level was significantly higher (p<0.05) in PEs of MM patients (11.0+/-6.6 microg/ml) than in LC (6.1+/-3.2 microg/ml) or BPD (6.2+/-5.0 microg/ml) patients. Immunohistochemistry showed a positive reaction for 90K in MM biopsy sections and positive staining limited to inflammatory infiltrates in LC sections. The level of 90K was significantly higher in cell culture media of MM than of LC or NHM (p<0.001). Bands representing proteins with molecular weight of approximately 90 kDa were detected by western blot in MM cellular extracts. An inverse correlation between PE 90K levels and MM patient age (r=-0.45; p=0.017) and a positive correlation between serum 90K levels and MM patient survival (r=0.62; p=0.006) were detected by linear regression analysis. Kaplan-Meier univariate analysis showed increased survival probability for MM patients with serum 90K level >7.3 microg/ml (log rank, p<0.05). This is the first report in MM of the expression of 90K and of its potential diagnostic and prognostic application.     

Evaluation of tumor markers for the detection of hepatocellular carcinoma in Yangon General Hospital,Myanmar

Levels of alpha-fetoprotein (AFP), its glycoforms AFP-L3 and AFP-P4, and proteins induced by vitamin K absence or antagonist-II (PIVKA-II) were determined in sera obtained from patients in Yangon General Hospital (20 with hepatocellular carcinoma (HCC), 29 with chronic liver diseases, including 3 with chronic hepatitis and 26 with cirrhosis of the liver, and 9 with other hepatobiliary diseases). Forty-five percent of the patients with HCC had serum AFP levels above 10,000 ng/ml, indicating that nearly half of the HCC patients were at an advanced stage of the disease. Thus, the AFP sensitivity was as high as 70% with 100% specificity for a cutoff level of 200 ng/ml. The sensitivity of AFP-L3 was 75% and a specificity 90% for a cutoff level of 15%. AFP-P4 showed a higher sensitivity of 80% and a similar specificity of 86% for a cutoff level of 12%. Combined evaluation of AFP-L3 and/or AFP-P4 increased the sensitivity to 90% with the same specificity of 86%, indicating that AFP-L3 and AFP-P4 are useful as adjuncts for diagnosis of HCC in the present population. PIVKA-II had a high sensitivity of 90%, although the specificity was lower than 45%, probably due to the low cutoff level, as some cholestatic patients were included in the control group.     

Detection of aberrant p16INK4A methylation in sera of patients with liver cirrhosis and hepatocellular carcinoma

Hepatocellular carcinomas (HCCs) show genomic alterations, including DNA rearrangements associated with HBV DNA integration, loss of heterozygosity, and chromosomal amplification. The genes most frequently involved are those encoding tumor suppressors. The p16INK4A tumor suppressor gene frequently displays genetic alteration in HCC tissues. The present study was performed to examine the incidence of methylated p16INK4A in the sera of liver cirrhosis (LC) and HCC patients, and to evaluate its role as a tumor marker of HCC. The sera of 23 LC patients and 46 HCC patients were examined in this study. The methylation status of p16INK4A was evaluated by methylation-specific PCR of serum samples. Methylated p16INK4A was detected in 17.4% (4/23) of LC patients and in 47.8% (22/46) of HCC patients. No association was demonstrated between p16INK4A methylation and serum AFP level. As the status of p16INK4A methylation was not associated with serum AFP level, it may have a role as a tumor marker of HCC.     

Antibodies to Haemophilus influenzae type b polysaccharide affect bacterial adherence and multiplication.

Since immunization of infants with conjugated Haemophilus influenzae type b (Hib) capsular polysaccharide (PS) vaccines results in a reduction of colonization, we determined the inhibitory effect of anti-Hib PS on two steps in the colonization, i.e., adherence of H. influenzae to nasopharyngeal epithelium and bacterial growth. Monoclonal antibody (MAb) E117-5 specific for Hib PS inhibited at a concentration of at least 80 microg/ml in vitro the adherence of Hib strain 770235f+b+ to oropharyngeal epithelial cells by 50% (P <, 0.02), but this MAb and sera from children immunized with Hib PS conjugate vaccine (n = 10) were not inhibitory in final dilutions containing up to 20 microg of anti-Hib PS per ml. The growth of Hib strain 770235f+b+ did completely stop in the presence of 5 microg of anti-Hib PS MAb E117-5 per ml and human sera with an anti-Hib PS concentration of 2 microg/ml or more, in contrast to the growth of the nonencapsular variant strain 770235f+b0.     

Second trimester maternal serum pregnancy specific beta-1 glycoprotein (SP-1) levels in normal and Down syndrome pregnancies

Maternal serum pregnancy specific beta-1 glycoprotein (SP-1) levels in the second trimester may be predictive of Down syndrome (DS). An enzyme immunoassay was used to measure SP-1 sera from 46 DS pregnancies and 117 normal control women matched for maternal age, gestational age, and length of storage. In the normal control samples, there were slight correlations between the SP-1 concentration and maternal age. The maternal serum SP-1 levels increased with each week of gestation from 15 to 20 weeks. All but one of the DS sera had SP-1 levels greater than the normal median. Using a cutoff of 2.8 multiples of the median (MoM), 15.2% of the DS pregnancies were detected with a false-positive rate of 4.3%. A combinational logistic regression analysis of maternal age and pregnancy related serum proteins will detect additional DS pregnancies and decrease the false-positive rate. The combination of maternal age and SP-1 detected 33 (71.7%) of Down syndrome pregnancies. The addition of maternal serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) levels allowed for the detection of 36 (78.3%) of the DS pregnancies with a decrease in the false-positive rate to 3.4%. The measurement of other serum constituents in conjunction with AFP appears to be a valuable addition to current screening programs, as this can increase the proportion of DS cases detected prenatally.     

Purification of a plasma protein that inhibits complement-mediated prevention of immune precipitation.

A pre-albumin glycoprotein that inhibits complement-mediated prevention of immune precipitation (PIP) has been purified from normal human serum by sequential affinity chromatography on IgG-Sepharose, protein A-Sepharose and Con A-Sepharose. A total of 4.7 mg of this protein were obtained from 50 ml of serum, representing a yield of 49% and a 253-fold degree of purification. We have named this glycoprotein gp60 as it has an apparent molecular weight of 60,000 on SDS-PAGE. The addition of gp60 to normal serum produced dose-dependent inhibition of both PIP and solubilization of immune precipitates. Maximum inhibition of PIP was achieved by a concentration of 600 micrograms/ml. A monospecific antiserum was produced by the immunization of rabbits, which enabled us to develop an enzyme-linked immunosorbent assay to measure serum concentrations of gp60. In 12 normal sera the mean concentration was 205 micrograms/ml (range 132-258 micrograms/ml), while that in 15 rheumatoid arthritis sera was 515 micrograms/ml (range 430-708 micrograms/ml). The serum concentration of this protein correlated with the level of inhibition of PIP (r = 0.91, P less than 0.01).     

Elevated serum levels of soluble Fas/APO-1 (CD95) in patients with hepatocellular carcinoma

Fas (APO-1/CD95)-mediated apoptosis plays an important role in liver cell destruction in viral hepatitis. Using sandwich ELISA, we measured serum levels of soluble Fas (sFas) in patients with hepatocellular carcinoma (HCC) who were positive for hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (HCV) antibody. sFas levels were significantly higher in HCC patients (median 4.07 ng/ml; range 0.14–29.18 ng/ml) than levels in age-matched healthy donors (0.29 ng/ml; 0–4.90 ng/ml) (P < 0.0001) and HBsAg or anti-HCV antibody-positive patients with liver cirrhosis (LC) (2.16 ng/ml; 0.24–8.39 ng/ml) (P = 0.0015). An arbitrary cut-off level of 3.03 ng/ml (mean + 3 s.d. of controls) revealed the positive frequency of sFas in each group: 1.7% in healthy subjects, 25.9% in LC, and 59.0% in HCC (sensitivity 59.0% and specificity 74.1%). All HCC sera tested contained transmembrane-deleted sFas and some contained another sFas lacking the Fas C-terminal. The positive frequency of either sFas (59.0%) or α-fetoprotein (AFP) (57.4%) in HCC patients reached 77.0%. HCC patients with multiple tumour foci (7.53 ng/ml; 1.40–29.18 ng/ml) had significantly higher sFas levels than did patients with a solitary tumour (2.70 ng/ml; 0.14–19.0 ng/ml) (P = 0.003). In all of the sFas-positive patients with a solitary tumour, surgical removal of the tumour reduced sFas levels to the negative in the first post-op week. These findings suggest that sFas may be closely linked with HCC and may be a candidate for a clinical parameter for HCC.     

Serum levels of galectin-3 and its ligand 90k/mac-2bp in colorectal cancer patients

Galectin-3 is an endogenous lectin that binds glycan epitopes of cell membrane and some extracellular glycoproteins such as integrins and laminin. Galectin-3 is involved in several biological activities including regulation of cellular cycle, modulation of adhesion and tumor progression and metastasis. 90K/Mac-2BP glycoprotein is also a serum galectin-3 ligand. 90K is able to modulate the immune reaction against tumors and viruses and its level increases in sera of several neoplastic diseases. In our study, we have evaluated levels of both glycoproteins in sera of non metastatic colon cancer patients. Interestingly, galectin-3 ranged higher in cancer patients than in controls (p<0.0001), particularly in more differentiated tumors (p<0.04). Moreover, 90K mean values ranged higher in right-side than in left-side colon cancer. In conclusion, serum galectin3 might represent a useful biomarker to evaluate colon cancer transformation and, together with its ligand 90K, could contribute to the characterization of colon cancer.     

肝癌患者血清和癌组织中锌指蛋白216表达增加

目的 寻找肝癌相关抗原.方法 应用SEREX技术对肝癌组织cDNA文库进行血清学筛选,获得人类锌指蛋白ZNF216.利用原核表达和亲和层析技术获得ZNF216的6*His融合蛋白,建立间接ELISA方法,检测血清中产生的ZNF216抗体水平;利用RT-PCR技术检测肝癌患者肝癌组织及癌旁组织内ZNF216 mRNA的水平.结果 肝癌患者血清中产生的抗ZNF216抗体水平高于正常个体,ZNF216 mRNA在肝癌组织内的表达明显高于癌旁组织.结论 ZNF216在肝癌病人血清及癌组织内的过表达可能参与肝癌的发生,但还需要进一步研究证明.     

Studies on the mechanism of elevation of serum PIVKA-II levels in alcoholic liver cirrhosis

We measured serum PIVKA-II concentrations in 18 patients with alcoholic liver cirrhosis. Alcoholic liver disease was diagnosed by the history of ethanol intake of more than 900 ml/day for over 10 years. Liver cirrhosis was diagnosed histologically. Infections with hepatitis B and C viruses were ruled out by assaying serum virus markers. No tumor was detected in liver by ultrasonography and computed tomography during observation period. None of the patients studied were positive for alpafetoprotein (AFP). Eight out of 18 (44.4%) patients with alcoholic liver cirrhosis showed elevated serum PIVKA-II levels. In contrast, only eight out of 93 (8.6%) patients with nonalcholic liver cirrhosis had elevated serum PIVKA-II levels. PIVKA-II is well known as a tumor marker of hepatocellular carcinoma (HCC). The rates of positive PIVKA-II found in alcoholic liver cirrhosis approached its rates in HCC. However, the time course for the elevation of serum PIVKA-II levels was different each other in alcoholic liver cirrhosis and HCC. In HCC, serum PIVKA-II "levels" continued to elevate until therapy. In contrast, its elevation was transient and its levels returned to baseline in alcoholic liver cirrhosis. The values of ALT (GPT), gamma-GTP, and ALP correlated poorly with serum PIVKA-II levels in patients with alcoholic liver cirrhosis. To investigate the mechanism by which elevation of serum PIVKA-II levels in patients with alcoholic liver cirrhosis occurred, we studied the effect of vitamin K on production of PIVKA-II and AFP by hepatocytes. Hepatocytes(Alexander PLC/PRF/F cell line) were cultured in the presence of various concentrations of vitamin K (Kaytwo, Eisai, Tokyo). Vitamin K had no effect on AFP production. In contrast, PIVKA-II production was inhibited by addition of vitamin K in a dose dependent manner. Moreover, elevation of serum PIVKA-II levels in patients with alcoholic liver cirrhosis was suppressed by administration of vitamin K (Kaytwo) to these patients. Taken together, these results suggest that vitamin K may have a role in the mechanism of PIVKA-II elevation in sera of these patients. Then, we measured serum concentrations of vitamin K(PK, MK-4, MK-7) in these patients. There was no correlation observed between vitamin K and PIVKA-II in these patients. This result suggests that elevation of serum PIVKA-II in these patients may not be due to vitamin K deficiency. One question not answered here is how serum PIVKA-II levels in these patients are suppressed by treatment with vitamin K (Kaytwo). More detailed analysis of the mechanism of elevation of serum PIVKA-II levels in patients with alcoholic liver cirrhosis is needed.     

Monoclonal antibody to a major surface glycoprotein immunogen differentiates isolates and subpopulations of Trichomonas vaginalis.

To produce monoclonal antibodies (MAbs) to highly immunogenic membrane proteins of Trichomonas vaginalis NYH286, the sera of subcutaneously infected BALB/c mice were first monitored for antibody to trichomonad surface proteins. The sera possessed antibody to one major surface protein by 7 days and antibody to numerous other trichomonad membrane proteins by 4 weeks postinfection. A hybridoma was then generated that synthesized an MAb, designated C20A3, which reacted to a parasite-derived glycoprotein possessing a molecular weight of 267,000 (267K glycoprotein). The immunogen corresponded to the single high-molecular-weight immunogenic surface protein recognized by 7-day mouse antisera. The MAb differentiated T. vaginalis isolates by a whole-cell enzyme-linked immunosorbent assay and by indirect immunofluorescence, using either fixed or live organisms. All isolates, however, possessed C20A3-reactive material when tested by enzyme-linked immunosorbent assay, using detergent extracts of the isolates incubated with MAb-coated microtiter well plates. The epitope was accessible to antibody binding on live T. vaginalis organisms expressing the major immunogen, and the 267K glycoprotein was readily removed from the parasite membranes by trypsinizing the intact trichomonads. The antigen incorporated radiolabeled glucose, mannose, and acetate. Also, an unlabeled 267K glycoprotein on nitrocellulose blots was detected by 125I-concanavalin A and 125I-wheat germ agglutinin, confirming the glycoprotein nature of the immunogen. Finally, of seven isolates used in this study, one possessed a cross-reactive 170K, rather than 267K, antigen. The data reinforce the idea that antigenic heterogeneity among T. vaginalis isolates may be a function of the presence or absence of high-molecular-weight glycoprotein immunogens from trichomonal membranes.     

Histological study of PIVKA-II expression in hepatocellular carcinoma and adenomatous hyperplasia

Although serum concentration of protein induced vitamin K absence or antagonist II (PIVKA-II) has been widely used for diagnosing hepatocellular carcinoma (HCC), little information is available concerning tissue PIVKA-II as an immunohistochemical marker for liver histology. In this study, we examined the expression of PIVKA-II in precancerous nodules (adenomatous hyperplasia) and various differentiation grades of HCC by immunohistochemical study using the monoclonal anti-PIVKA-II antibody (MU-3). We examined the relationship between tissue PIVKA-II staining and serum PIVKA-II level, tumor histology and tumor size. PIVKA-II was mainly detected in the cytoplasm of the HCC cells. The positive rates of PIVKA-II were as follows: adenomatous hyperplasia (AH), 0% (0/9); well-differentiated HCC, 65% (15/23); moderately differentiated HCC, 85% (22/26); poorly differentiated HCC, 54% (7/13). The expression of tissue PIVKA-II staining in moderately differentiated HCC was significantly higher than in well- or poorly differentiated HCC, whereas the serum PIVKA-II level in poorly differentiated HCC was higher than well- or moderately differentiated HCC. There was no relationship between the expression of PIVKA-II in cancer tissues and serum levels of PIVKA-II. Immunohistochemical studies revealed that PIVKA-II was expressed even in small-sized or well-differentiated HCC cells, but expression was not detected in AH. It was concluded that PIVKA-II is a useful immunohistochemical marker, even in small-sized or well-differentiated HCC.     

Sandwich ELISA assay for quantitative measurement of SP-40,40 in seminal plasma and serum

SP-40,40 was purified from human plasma by PEG fractionation, DEAE-Sephacel, Phenyl-Toyopearl 650M, Bio-Gel A-0.5m and hydroxylapatite chromatographies. Three monoclonal antibodies (IF12, IID9 and IVF4) to this protein were prepared: IF12 and IID9 were specific for the beta subunit and IVF4 for the alpha subunit. The concentrations of SP-40,40 in seminal plasmas and sera were determined using a sandwich ELISA method. The results showed that the average concentrations of SP-40,40 were 438 +/- 285 micrograms/ml in seminal plasmas and 111 +/- 50 micrograms/ml in sera of normal donors. SP-40,40 concentrations in seminal plasmas of Klinefelter and excretory azoospermia patients were similar to those of normal donors. However, those of oligozoospermia and idiopathic azoospermia patients were about half the normal value.     

Rapid, sensitive, and specific lateral-flow immunochromatographic device to measure anti-anthrax protective antigen immunoglobulin g in serum and whole blood

Evidence from animals suggests that anti-anthrax protective antigen (PA) immunoglobulin G (IgG) from vaccination with anthrax vaccine adsorbed (AVA) is protective against Bacillus anthracis infection. Measurement of anti-PA IgG in human sera can be performed using either enzyme-linked immunosorbent assay or fluorescent covalent microsphere immunoassay (ELISA) (R. E. Biagini, D. L. Sammons, J. P. Smith, B. A. MacKenzie, C. A. Striley, V. Semenova, E. Steward-Clark, K. Stamey, A. E. Freeman, C. P. Quinn, and J. E. Snawder, Clin. Diagn. Lab. Immunol. 11:50-55, 2004). Both these methods are laboratory based. We describe the development of a rapid lateral-flow immunochromatographic assay (LFIA) test kit for the measurement of anti-PA IgG in serum or whole-blood samples (30-microl samples) using colloidal gold nanoparticles as the detection reagent and an internal control. Using sera from 19 anthrax AVA vaccinees (anti-PA IgG range, 2.4 to 340 microg/ml) and 10 controls and PA-supplemented whole-blood samples, we demonstrated that the LFIA had a sensitivity of approximately 3 microg/ml anti-PA IgG in serum and approximately 14 microg/ml anti-PA IgG in whole blood. Preabsorption of sera with PA yielded negative anti-PA LFIAs. The diagnostic sensitivity and specificity of the assay were 100% using ELISA-measured anti-PA IgG as the standard. This kit has utility in determining anti-PA antibody reactivity in the sera of individuals vaccinated with AVA or individuals with clinical anthrax.     

Usefulness of the Novel Oncofetal Antigen Glypican-3 for Diagnosis of Hepatocellular Carcinoma and Melanoma

Glypican-3 (GPC3) mRNA and protein are expressed in >80% of human hepatocellular carcinomas (HCC) but not in normal tissues except for placenta and fetal liver. The oncofetal antigen GPC3 is a glycosylphosphatidyl inositol-anchored membrane protein and may be secreted. It is a novel tumor marker for human HCC: GPC3 protein was present in sera from 40-50% of HCC patients, but was not detected in sera from patients with liver cirrhosis or chronic hepatitis, or in sera from healthy individuals. alpha-Fetoprotein (AFP) and PIVKA-II (protein induced by vitamin K absence or antagonist-II), are well known major tumor markers for HCC. Generally, AFP shows high positivity for HCC but also high false-positivity in detection assays. Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) is a recently described marker of HCC. Detection of AFP-L3 shows a much higher specificity than AFP, but a lower sensitivity. On the other hand, detection of PIVKA-II shows a lower false-positivity, but is not always sensitive enough to detect low levels secreted by small HCCs. There was no correlation between the three tumor markers, AFP, PIVKA-II, and GPC3 in terms of their presence in HCC cells. All three tumor markers showed similar positivity in patients with HCC, detecting 80% of patients with the disease. GPC3 is also a novel tumor marker for the diagnosis of human melanoma, especially in the early stages of the disease. Expression of GPC3 mRNA and protein was evident in tumor cells from >80% of patients with melanoma and melanocytic nevus, which is a common benign lesion. GPC3 protein was detected in sera from 40% (36/91) of melanoma patients, but not in sera from those with large congenital melanocytic nevus, or from healthy donors. Surprisingly, we detected serum GPC3 even in patients with stage 0, in situ melanoma. The positive detection rate of serum GPC3 at stage 0, I, and II (44.4%, 40.0%, 47.6%, respectively) was significantly higher than that of 5-S-cysteinyldopa, a well known tumor marker for melanoma (0.0%, 8.0%, and 10.0%, respectively). Interestingly, GPC3 was highly immunogenic in mice and elicited effective anti-tumor immunity with no evidence of autoimmunity. Thus, GPC3 is useful for diagnosis of HCC and melanoma and may also have a role in immunotherapy or tumor prevention. However, studies in humans are warranted.     

Antimicrobial susceptibility of multidrug-resistant Gram negative bacteria to fosfomycin

We evaluated the antimicrobial activity of fosfomycin against a randomly selected sample of 30 Klebsiella pneumoniae, 30 Pseudomonas aeruginosa, and 30 Acinetobacter baumannii multidrug-resistant, clinical isolates from patients in a general tertiary care hospital in Athens, Greece. Standard laboratory methods were used for susceptibility testing to commonly used antibiotics and the detection of extended-spectrum-beta-lactamase (ESBL) and metallo-beta-lactamase (MBL) production. The minimum inhibitory concentration (MIC) of fosfomycin for each isolate was determined by the agar dilution method. All K. pneumoniae isolates were both ESBL and MBL producers; all P. aeruginosa isolates were ESBL producers. The K. pneumoniae strains had fosfomycin MICs distributed across a range of 8-64 microg/ml; MIC(50) was 16 microg/ml and MIC(90) 32 microg/ml. The fosfomycin MICs of the P. aeruginosa strains had a distribution across a range of 4 to over 512 microg/ml; MIC(50) was 32 microg/ml and MIC(90) 128 microg/ml. The fosfomycin MICs of the A. baumannii strains had a distribution across a range of 64 to over 512 microg/ml; MIC(50) was 256 microg/ml and MIC(90) more than 512 microg/ml. Although standardized fosfomycin MIC interpretative breakpoints for the species studied are lacking, the findings of our study support the idea that fosfomycin may be further investigated as one among a decreasing list of therapeutic options for the treatment of infections due to multidrug-resistant strains of, primarily, K. pneumoniae and, secondly, P. aeruginosa.     

The interrelationship between HBV-markers and HIV antibodies in patients with hepatocellular carcinoma.

To determine the interrelationship between hepatitis B viral markers (HBV), the human Immunodeficiency virus (HIV), and hepatocellular carcinoma (HCC) in HCC patients, a total of 282 subjects were included in the study. Out of 282 subjects, 182 were HCC patients as determined by raised alpha-feto-protein (AFP) of greater than 1,000 ng/ml. The other 100 control patients presented with other conditions and had detectable AFP of less than 1,000 ng/ml in their sera. On presentation, 10 ml of venous blood was drawn from each enrolled subject and taken to the laboratory. HBV markers were detected using commercial reagents; HIV antibodies were detected by the commercial ELISA tests and were confirmed by Western blot. AFP was detected using an RIA technique. Of 282 examined subjects 182 (64.5%) had detectable AFP of greater than 1,000 ng/ml. 113 (40.1%) and 103 (36.5%) had HBsAg and Anti-HBc respectively. However, HBeAg was found in 21 of 113 (18.6%) of the HBsAg positive only. Anti-HIV antibodies were present in 15 (5.3%) of the 282 tested individuals. Only 1 (1.0%) of the control group had detectable anti-HIV antibodies in the serum. Eleven percent and 4.0% of the same control group had HBsAg and anti-HBc in their sera respectively. The study shows a significant correlation between HCC and HBV-markers (P less than 0.0001). Similarly, a significant correlation between anti-HIV antibodies and HBV-markers, (P less than 0.0001) was found.     

ELISA for human serum leucine-rich alpha-2-glycoprotein-1 employing cytochrome c as the capturing ligand

Leucine-rich alpha-2-glycoprotein-1 (LRG) is a serum glycoprotein of unknown function that has shown promise based on qualitative assessments as a biomarker for certain diseases including microbial infections and cancer. However, the lack of a quantitative assay for LRG has limited its application. Here an indirect enzyme-linked immunosorbent assay (ELISA) for quantifying LRG in human serum is described in which cytochrome c is employed as the capturing ligand and a monoclonal antibody specific for LRG is used to detect the captured glycoprotein. Application of this assay in quantifying LRG in various patients' sera is demonstrated. The concentration of LRG in sera of control subjects as determined by this assay is approximately 50 microg/ml. Consistent with expectations from published reports, LRG was found to be significantly elevated in the sera of some patients with a bacterial infection (toxic shock syndrome, TSS). LRG was only slightly elevated in patients infected with the human immunodeficiency virus as compared to uninfected control subjects, while normal levels of LRG were observed in patients with non-infectious diseases (inflammatory arthritis and neurological disorders, primarily Parkinson's disease). Although LRG and C-reactive protein (CRP) are both produced by the liver and are classified as acute-phase proteins, there was no significant correlation between the levels of LRG and CRP in the sera of the patients. Thus, LRG and CRP measurements are non-redundant and indicate different physiological contexts. The ELISA described in this report should be useful to further assess serum LRG as a biomarker for clinical diagnostics.     

gC1qR/p33 blockade reduces Staphylococcus aureus colonization of target tissues in an animal model of infective endocarditis

gC1qR/p33 (gC1qR) is a ubiquitously expressed cellular protein that is also found in plasma and the extracellular matrix. In addition to its role in modulating the activation of complement and kinin cascades, gC1qR has been identified as a putative host ligand for endovascular pathogens, including Staphylococcus aureus. The present study provides evidence of the ability of soluble gC1qR to enhance S. aureus-fibrinogen interactions via simultaneously binding fibrinogen and S. aureus. This interaction was inhibited in vitro by two monoclonal antibodies (MAbs 74.5.2 and 60.11) recognizing distinct structural and functional domains of gC1qR. To evaluate the in vivo role of gC1qR, MAbs 74.5.2 and 60.11 were used in an experimental rat model of S. aureus endocarditis. Each MAb (100 mg/kg of body weight, given intraperitoneally) reached sustained (>60 h) and high (100 to 200 microg/ml) serum levels. Prophylaxis with MAb 60.11 or 74.5.2 caused substantial reductions in S. aureus colonization of aortic valves, kidneys, and the spleen compared to untreated controls. However, only MAb 74.5.2 prophylaxis therapy reached statistical significance, and only sera from animals protected with MAb 74.5.2 inhibited gC1qR-mediated S. aureus interactions with fibrinogen. Although not statistically significant, the reductions in bacterial colonization achieved with MAb 60.11 alone and in combination with MAb 74.5.2 (versus MAb 74.5.2 alone) suggest that there are effects of gC1qR blockade on S. aureus infective endocarditis in addition to blocking gC1qR-mediated S. aureus binding to fibrinogen. Such impacts may include direct modulation of complement (MAb 60.11) and kinin cascades (MAb 74.5.2) and/or activation of immune and inflammatory responses via localized immune complex formation.