Performance of antigen B isolated from different hosts and cyst locations in diagnosis of cystic echinococcosis

BACKGROUND

The aim of this study was to assess the performance of Antigen B (AgB) isolated from different Echinococcusgranulosus intermediate hosts and from different cyst locations for immunodiagnosis of human cystic echinococcosis (CE).

METHODS

Hydatid cyst fluids were collected from lung and liver cysts of sheep, liver cysts of goats, lung cysts of camels and cattle, and liver cysts of human. AgB was purified from each of these hydatid cysts fluids. Serum samples obtained from 47 pathologically confirmed cases of CE along with 30 sera samples from non-CE patients and 40 sera from healthy individuals were tested by ELISA using AgB prepared from different hosts or cyst locations.

RESULTS

The highest sensitivity (97.8%) for diagnosis of CE was seen with AgB prepared from human liver cysts. This maximal sensitivity was followed by AgB isolated from those of sheep liver and lung cysts. The least sensitivity was found with AgB prepared from bovine lung cysts. The highest specificities (97.1%) were observed with AgB isolated from human liver cysts followed by those of sheep and goat liver cysts while the lowest specificity was seen with AgB isolated from bovine lung cysts. In view of the specificities and sensitivities of the different AgB, the best validity was found for AgB prepared from human liver cysts while the least validity was found with AgB prepared from bovine lung cysts.

CONCLUSION

For any AgB-based tests, obtaining of the antigen from one of these sources will significantly increase the diagnostic sensitivity and specificity of the assay.

Anti-Taenia solium larval stage Ig G antibodies in patients with epileptic seizures

Background:

Cysticercosis is the most common differential diagnosis for epilepsy. The present study was carried out to assess the serological response among patients with epileptic seizures visiting JIPMER Hospital Puducherry.

Materials and Methods:

A total of 934 serum samples were collected from patients with epileptic seizures. A standardized questionnaire was designed to obtain information on the demographic, socioeconomic, environmental, and behavioral characteristics related to the transmission of infection. An enzyme-linked immunosorbent assay (ELISA) was used to detect the anti-Taenia solium larval stage IgG antibodies. Samples found reactive and inconclusive by ELISA were further tested by the enzyme immunotransfer blot (EITB).

Results:

The frequency of antibodies in the serum samples of the above-mentioned population was 16.2% by EITB. Anti-Taenia solium larval stage antibodies were detected in serum samples of 163 patients, out of which 27 (16.56%) patients belonged to the 0 – 15-year age group, 82 (50.30%) patients were in the 16 – 40-year age group, and 52 (31.90%) patients were above 41 years, respectively. Although the sera from males had higher OD values than those from females, the difference was not statistically significant. Out of 163 seropositive by ELISA, 152 (93.25%) were found to be positive by EITB. Out of the 152, 61 (40.13%) were farmers and 79 (51.97%) were office or factory workers.

Conclusions:

In conclusion, the results indicate a probable endemic situation and a high prevalence of cysticercosis in patients with epileptic seizures. Living in poor sanitary conditions seems to be an important factor related to human cysticercosis in Puducherry and the neighboring districts of Tamil Nadu.

Effect of Anticoagulants on Amyloid β-Protein Precursor and Amyloid Beta Levels in Plasma

Altered levels of amyloid β-protein precursor (AβPP) and/or amyloid beta (Aβ) are characteristic of several neurological disorders including Alzheimer's disease (AD), Down syndrome (DS), Fragile X syndrome (FXS), Parkinson's disease (PD), autism and epilepsy. Thus, these proteins could serve as valuable blood-based biomarkers for assessing disease severity and pharmacological efficacy. We have observed significant differences in Aβ_1-42 levels in human plasma dependent on the anticoagulant utilized during blood collection. Our data suggests that anticoagulants alter AβPP processing and that care needs to be used in comparing published studies that have not utilized the same blood collection methodology.

Prevalence of cryptosporidium infection in immunocompromised patients, in South-west of iran, 2009-10

BACKGROUND

Cryptosporidium is a protozoan parasite with worldwide distribution. The aim of this study was to estimate the prevalence of Cryptosporidium infection by antigen detection in faeces among immunocompromised patients referred to educational hospitals of Ahvaz City, South-West of Iran, 2009-2010.

METHODS

Fecal samples from 176 immunocompromised patients were collected and Cryptosporidium coproantigen test was performed using ELISA method (DRG kit, Germany). A questionnaire was completed for each case and the results were analyzed using descriptive and Chi-Square tests, by SPSS statistical software (15(th) version).

RESULTS

Our study indicated 5.1% Cryptosporidium infection prevalence in the immunocompromised participated population. Furthermore, 4.2 %, 4 %, 4.5 % and 9.1 % infection rates were identified in children suffered from hematopoietic malignancy, adult cancer patients, renal transplant recipients, and HIV(+) cases, respectively. There was not significant correlation between the infection and age and gender (P>0.05). Infection was most frequent among HIV(+) patients.

CONCLUSION

The present study confirmed the high prevalence of Cryptosporidium antigen in fecal samples of immunocompromised patients in the region. As no chemotherapeutic agents have yet proven, especially in immunosuppressed patients, therefore our results highlight the importance of preventive intervention in these groups.

Circulating Natural IgM Antibodies Against Angiogenin in the Peripheral Blood Sera of Patients with Osteosarcoma as Candidate Biomarkers and Reporters of Tumorigenesis

BACKGROUND

Tumor immunology research has led to the identification of a number of tumor-associated self antigens, suggesting that most tumors trigger an immunogenic response, as is the case in osteosarcoma, where the detection of natural serum IgM antibodies might achieve the diagnosis of osteosarcoma. Natural IgM antibodies to tumor-associated proteins may expand the number of available tumor biomarkers for osteosarcoma and may be used together in a serum profile to enhance test sensitivity and specificity. Natural IgM antibodies can be consistently detected in the peripheral blood sera months to years before the tumor is diagnosed clinically. The study of the level of a potential biomarker many months (or years) prior to diagnosis is fundamentally important. Integrated circulating and imaging markers in clinical practice treating osteosarcoma have potential applications for controlling tumor angiogenesis.

OBJECTIVES

To study the expression of natural IgM antibodies to the tumor antigens of angiogenesis in the peripheral blood sera of osteosarcoma patients and healthy individuals, and to develop serum-based predictive biomarkers.

METHODS

Peripheral venous blood samples were collected from 117 osteosarcoma patients and 117 patients with other tumors. All diagnosis was histologically confirmed. Staging of patients was performed according to the Enneking Surgical Staging System. The control group consisted of 117 age- and sex- matched healthy individuals. In this study, novel immunoconjugates were designed, synthesized and then used to develop a rapid, specific and sensitive enzyme-linked immunosorbent assay (ELISA) method to detect angiogenin (ANG)-IgM directly in the peripheral blood sera of humans.

RESULTS

Serum ANG-IgM levels are significantly higher in osteosarcoma patients than in healthy individuals (P < 0.005). Serum ANG-IgM levels varied widely, but were highly dependent on the concentration of IgM (r = 0.85; P < 0.0005). We found ANG-IgM in the sera of 85% of newly diagnosed osteosarcoma patients and ANG-IgM levels were significantly higher in osteosarcoma patients compared to any other tumors (P < 0.001).

CONCLUSIONS

These results demonstrated that the combined biomarker ANG-IgM has greater sensitivity and specificity in early diagnosis of osteosarcoma patients than the traditional biomarkers (ANG and vascular endothelial growth factor). Circulating ANG-IgM immune complexes can potentially serve as a biomarker for increased risk of osteosarcoma, because relatively high serum levels were also detected in otherwise healthy individuals with a first degree family history of osteosarcoma and in patients with a diagnosis of benign conditions. Immunological aspects of angiogenesis for managing osteosarcoma will have a practical value in early diagnosis, prognosis and monitoring response to antiangiogenic therapy.

Preparation of herbal tea as infusion or by maceration at room temperature using mistletoe tea as an example

Herbal tea can be prepared by infusion or maceration at room temperature resulting in different compositions of extractable constituents, which possibly influences the mode of action or safety profile. Knowledge on this topic is limited. The aim of this study was to investigate the substantial differences between infusion and maceration as recommended preparation methods for the preparation of herbal mistletoe tea, a traditional remedy against cardiovascular diseases. No active substances are known but analytical marker substances such as proteins, triterpenoids, phenylpropane derivatives and flavonoids can be quantified within the herb and the different herbal tea preparations. Whereas phenylpropane derivatives were completely extracted by infusion and maceration, neither method dissolved viscotoxins. 43% of mistletoe lectins were extracted by maceration, whereas by infusion they are inactivated by thermal degradation. By contrast, oleanolic acid and betulinic acid are present in higher concentrations in infusates compared with macerates, but even infusion extracted less than 2%. Infusion extracted 43% of flavonoid-like substances and maceration only 31%. In conclusion this study determines some differences between both extraction methods on the profile of solved substances. The relevance of it should be determined in studies dealing with the efficacy of herbal mistletoe tea.

Prevalence of Toxoplasma gondii infection in stray and household cats in regions of Seoul, Korea

The principal objective of this study was to investigate the prevalence of toxoplasmosis in household and stray cats in Seoul, Republic of Korea. We collected blood samples from 72 stray and 80 household cats, and all samples were examined by ELISA and nested PCR. The overall positive rates of Toxoplasma gondii in stray cats were 38.9% (28/72), with 15.3% (11/72) in ELISA and 30.6% (22/72) in PCR. The positive rate in male stray cats was slightly higher than that of female stray cats. The highest positive rate of T. gondii infection was noted in Gangnam and Songpa populations in ELISA and in Gwangjin population in PCR. In household cats, however, we could not detect any specific antibodies or DNA for T. gondii. In conclusion, we recognized that the infection rate of toxoplasmosis in stray cats in Seoul was considerably high but household cats were free from infection.

Serological Evaluation of EgAgB16 kDa, a Recombinant Antigen from Echinococcus granulosus for Diagnosis of Human Hydatidosis

BACKGROUND

Regarding that accurate diagnosis of human hydatidosis still needs more investigations, the present study was conducted to clone, express, and evaluate the gene encoding AgB subunits (EgAgB16 kDa) from Echinococcus granulosus (Iranian G1 strain) and its evaluation by ELISA test.

METHODS

DNA was extracted from protoscoleces and was utilized by PCR for strain identification. Total RNA was prepared with RNeasy protect mini kit from E. granulosus (Iranian G1 strain) protoscoleces collected from naturally infected sheep with hydatid cyst. Recombinant AgB16 kDa was produced using pETDuet as vector and evaluated by ELISA method. A panel of sera including hydatid cyst-infected individuals (n=72), healthy individual (n=48), toxoplasmosis (n=4), strongyloidosis (n=4), kala-azar (n=5) and tuberculosis (n=5) were examined using this recombinant antigen.

RESULTS

Recombinant protein was purified by affinity chromatography using His-Tag column. After purification, recombinant protein was confirmed by western blot analysis using His Tag monoclonal antibody or hydatid positive human serum. The sensitivity, specificity; positive and negative predictive values were calculated as 93.5%, 95.6%, 96% and 92.9%, in that order. The cut-off point was detected 0.3 for rAgB16.

CONCLUSION

While the produced recombinant AgB16 kDa showed promising results in diagnosing human hydatidosis, but more investigations should be implemented to reach an accurate gold standard.

A bivalent glycopeptide to target two putative carbohydrate binding sites on FimH

FimH is a mannose-specific bacterial lectin found on type 1 fimbriae with a monovalent carbohydrate recognition domain (CRD) that is known from X-ray studies. However, binding studies with multivalent ligands have suggested an additional carbohydrate-binding site on this protein. In order to prove this hypothesis, a bivalent glycopeptide ligand with the capacity to bridge two putative carbohydrate binding sites on FimH was designed and synthesized. Anti-adhesion assays with the new bivalent ligand and type 1-fimbriated bacteria have revealed, that verification of the number of carbohydrate binding sites on FimH with a tailor-made bivalent glycopeptide requires further investigation to be conclusive.

Hepatitis B virus genotyping by enzyme-linked immunosorbent assay in Taiwan

PURPOSE

Restriction fragment length polymorphism (RFLP) and enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies (mAbs) were used in this study to detect genotypes of HBV, and the efficiency and precision of ELISA using the mAbs for HBV genotype detection were also estimated.

METHODS

The ELISA with mAbs method was used for the detection of HBV genotype in a Taiwanese population. The HBV genotypes of 100 chronic hepatitis B patients were determined by ELISA and were then compared with those obtained using RFLP.

RESULTS

Genotype B was found to be the most prevalent in this study (63% by RFLP; 62% by ELISA) followed by genotype C (31% by RFLP; 35% by ELISA). There was no significant difference between the results obtained by RFLP and ELISA (P = 0.75). The ELISA overall genotypeable rate, the correct genotyping rate from genotypeable specimens, and the concordance of the HBV genotyping assay was 96.00, 94.79, and 91.00%; for the ELISA HBV genotyping assay for genotype B specimens was 96.77, 100.00, and 96.77%; and for genotype C specimens was 97.14, 91.18, and 88.57%, respectively. The mean HBV DNA level was higher in the specimens that could be genotyped by both RFLP and ELISA samples (6.24 ± 1.77 vs. 2.34 ± 0.90, log IU/ml), and a significant difference in terms of HBV DNA level of more than 2 × 10(3) IU/ml was identified between the genotyped RFLP samples (P < 0.001).

CONCLUSIONS

ELISA is a practical and a useful method for HBV genotyping in a clinical setting in Taiwan, in particular for patients with lower levels of HBV DNA.

Quantitative analysis of nerve growth factor in the amniotic fluid during chick embryonic development

Nerve growth factor (NGF) and most neurotrophic factors support the proliferation and survival of particular types of neurons. Besidesthe pivotal role of NGF in the development of neuronal cells, it also has important functions on non-neuronal cells. The amnion surrounds the embryo, providing an aqueous environment for the embryo. A wide range of proteins has been identified in human amniotic fluid (AF). In this study, total protein concentration (TPC) and NGF level in AF samples from chick embryos were measured using a Bio-Rad protein assay, enzyme linked immunosorbent assay (ELISA) and Western blot. TPC increased from days E10 to day E18. There was a rapid increase in AF TPC on day E15 when compared to day E16. No significant changes in NGF levels have been seen from day E10 to day E14. There was a rapid increase in NGF content on days E15 and E16, and thereafter the levels decreased from day E16 to day E18. Since, NGF is important in brain development and changes in AF NGF levels have been seen in some CNS malformations, changes in the TPC and NGF levels in AF during chick embryonic development may be correlated with cerebral cortical development. It is also concluded that NGF is a constant component of the AF during chick embryogenesis.

Development and characterization of a monoclonal antibody against Ochratoxin B and its application in ELISA

A monoclonal antibody specific to ochratoxin B (OTB) was employed for the development of an indirect competitive OTB-ELISA. The optimized OTB-ELISA resulted in a limit of detection (LOD) for OTB of 3 µg/L (8 nM), a limit of quantification (LOQ) of 3.7 µg/L (10 nM), and a 50% inhibitory concentration (IC(50)) of 150 nM. Due to very low cross-reactivity to OTA (2.7%) and structurally related molecules (0%), this OTB-ELISA was found to be suitable to detect OTB with excellent precision in different matrices, i.e., beer, coffee and wine. Therefore, this OTB-ELISA will allow screening of OTB in food and feed products.

An imported case of echinococcosis of the liver in a Korean who traveled to western and central Europe

Echinococcus granulosus, an intestinal tapeworm of dogs and other canids, infects humans in its larval stage and causes human echinococcosis or hydatid disease. In the Republic of Korea, 31 parasite-proven human echinococcosis cases have been reported, most of which were imported from the Middle East. We recently examined a 61-year-old Korean man who had a large cystic mass in his liver. ELISA was negative for tissue parasitic infections, including echinococcosis, cysticercosis, paragonimiasis, and sparganosis. The patient underwent surgery to remove the cyst, and the resected cyst was processed histopathologically for microscopic examinations. In sectioned cyst tissue, necrotizing protoscolices with disintegrated hooklets of E. granulosus were found. In some areas, only freed, fragmented hooklets were detected. The patient had traveled to western and central Europe in 1996, and had no other history of overseas travel. We report our patient as a hepatic echinococcosis case which was probably imported from Europe.

Recombinant SAG1 Antigen to Detect Toxoplasma gondii Specific Immunoglobulin G in Human Sera by ELISA Test

BACKGROUND

Although some serological tests for the detection of Toxoplasma gondii-specific immunoglobulin are commercially available, better diagnostic tools are needed. The aim of present study was to evaluate the usefulness of the recombinant Toxoplasma gondii SAG1 antigen for the recognition of toxoplasmosis by ELISA.

METHODS

This study was conducted in Cellular and Molecular Biology Research Centers, Shahid Beheshti University, M.C., Tehran, Iran in 2008-2009. Surface antigen 1 (SAG1), a tachyzoite stage-specific protein, was subcloned into an expression vector and was subsequently transformed into BL21 (DE3) pLysS competent bacterial cells. After inducing expression of the recombinant antigen, the protein product was purified using Ni-affinity chromatography. The immunoreactivity of recombinant SAG1 (rSAG1) was analyzed by SDS-PAGE and western blotting. The reactivity of the rec-SAG1 protein was evaluated using an ELISA.

RESULT

Sensitivity and specificity of the generated recombinant-ELISA (rec-ELISA) compared to a commercially available ELISA (com-ELISA) were 88.4% and 88%, respectively.

CONCLUSION

Recombinant SAG1 produced in E. coli is a promising antigen that can be used in diagnostic assays for the detection of specific antibodies against T. gondii.

Melatonin plays a protective role in postburn rodent gut pathophysiology

Melatonin is a possible protective agent in postburn gut pathophysiological dynamics. We investigated the role of endogenously-produced versus exogenously-administered melatonin in a major thermal injury rat model with well-characterized gut inflammatory complications. Our rationale is that understanding in vivo melatonin mechanisms in control and inflamed tissues will improve our understanding of its potential as a safe anti-inflammatory/antioxidant therapeutic alternative. Towards this end, we tested the hypothesis that the gut is both a source and a target for melatonin and that mesenteric melatonin plays an anti-inflammatory role following major thermal injury in rats with 3^rd degree hot water scald over 30% TBSA. Our methods for assessing the gut as a source of melatonin included plasma melatonin ELISA measurements in systemic and mesenteric circulation as well as rtPCR measurement of jejunum and terminal ileum expression of the melatonin synthesizing enzymes arylalkylamine N-acetyltransferase (AA-NAT) and 5-hydroxyindole-O-methyltransferase (HIOMT) in sham versus day-3 postburn rats. Our melatonin ELISA results revealed that mesenteric circulation has much higher melatonin than systemic circulation and that both mesenteric and systemic melatonin levels are increased three days following major thermal injury. Our rtPCR results complemented the ELISA data in showing that the melatonin synthesizing enzymes AA-NAT and HIOMT are expressed in the ileum and jejunum and that this expression is increased three days following major thermal injury. Interestingly, the rtPCR data also revealed negative feedback by melatonin as exogenous melatonin supplementation at a dose of 7.43 mg (32 μmole/kg), but not 1.86 mg/kg (8 μmole/kg) drastically suppressed AA-NAT mRNA expression. Our methods also included an assessment of the gut as a target for melatonin utilizing computerized immunohistochemical measurements to quantify the effects of exogenous melatonin supplementation on postburn gut mucosa barrier inflammatory profiles. Here, our results revealed that daily postburn intraperitoneal melatonin administration at a dose of 1.86 mg/kg (8 μmole/kg) significantly suppressed both neutrophil infiltration and tyrosine nitrosylation as revealed by Gr-1 and nitrotyrosine immunohistochemistry, respectively. In conclusion, our results provide support for high mesenteric melatonin levels and dynamic de novo gut melatonin production, both of which increase endogenously in response to major thermal injury, but appear to fall short of abrogating the excessive postburn hyper-inflammation. Moreover, supplementation by exogenous melatonin significantly suppresses gut inflammation, thus confirming that melatonin is protective against postburn inflammation.

Evaluation of plasma hormone concentrations using Enzyme-Immunoassay/Enzyme-linked Immunosorbent assay in healthy Indian men: Effect of ethnicity

The study involved three ethnic groups of India; Rajputs, Gorkhas and South-Indians. Each group consisted of ∼40 healthy, male soldiers between 20-50 years. The reference ranges for cortisol, testosterone, prolactin, arginine vasopressin and proAtrial natriuretic peptide(1-98) were determined using Enzyme-Immunoassay (EIA) while plasma levels of thyroid-stimulating hormone, triiodothyronine, free-triiodothyronine, thyroxine and freethyroxine were measured using Enzyme-linked immunosorbent assay (ELISA). The results indicated that plasma hormone concentrations were within physiological range and inter-ethnic differences were most prominent between north- (Rajputs and Gorkhas) and south- Indians. In comparison to Radioimmunoassay, the EIA method for prolactin, thyroid-stimulating hormone, free-thyroxine gave higher values while the ELISA method for triiodothyronine, free-triiodothyronine, and thyroxine gave lower values. These differences are due to differences in assay standards and design.

Evaluation of an enzyme-linked immunosorbent assay using purified, deglycosylated histoplasmin for different clinical manifestations of histoplasmosis

Diagnosis of invasive fungal diseases remains problematic, especially in undeveloped countries. We have developed an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Histoplasma capsulatum using metaperiodate treated purified histoplasmin (ptHMIN). Our ELISA was validated comparing sera from patients with histoplasmosis, related mycoses, and healthy individuals. The overall test specificity was 96%, with sensitivities of 100% (8/8) in acute disease, 90% (9/10) in chronic disease, 89% (8/9) in disseminated infection in individuals without HIV infection, 86% (12/14) in disseminated disease in the setting of HIV infection and 100% (3/3) in mediastinal histoplasmosis. These parameters are superior to the use of untreated histoplasmin in diagnostic ELISAs. The high specificities, sensitivities, and simplicity of our ELISA support further development of a deglycosylated HMIN ELISA for clinical use and for monitoring the humoral immune response during therapy in patients with chronic and disseminated histoplasmosis.

Evaluation of the stability of coated plates with antigen at different temperatures and times by ELISA test to diagnose fasciolosis

BACKGROUND

Considering that ELISA method presently is the test of choice for diagnosis of fasciolosis, the present study was undertaken to evaluate the maximum validity of coated plates at different temperatures and different times during one year of evaluation.

METHODS

Serum samples of patients infected with fasciolosis (n=10), hydatidosis (n=5), toxocariasis (n=5), and negative control sera (n=5) were examined. Two series of plates were considered. The first series were coated with Fasciola homogenate Ag 12 ug/ml, and after some steps were blocked with gelatin and preserved at different temperatures as -80°C, -20°C, -4°C and +4°C. The 2(nd) series were treated under the same criteria but were not blocked with gelatin. Each series were examined by ELISA test from 1(st) month to 12(th) month. Sera with 1:125 dilution, and peroxidase-conjugated goat anti-human IgG diluted 1:10000 were considered optimum.

RESULTS

To ease reporting the results and due to many similarities only results related to 1(st), 6(th) and 12(th) months were analyzed and sensitivity, specificity plus cut-off were determined for each series separately.

CONCLUSION

Preserving the coated plates, while unblocked at -80°C for 6-8 months is pertinent and functional and in that case, we can be sure the best out put would be applicable.

Sensing the deadliest toxin: technologies for botulinum neurotoxin detection

Sensitive and rapid detection of botulinum neurotoxins (BoNTs), the most poisonous substances known to date, is essential for studies of medical applications of BoNTs and detection of poisoned food, as well as for response to potential bioterrorist threats. Currently, the most common method of BoNT detection is the mouse bioassay. While this assay is sensitive, it is slow, quite expensive, has limited throughput and requires sacrificing animals. Herein, we discuss and compare recently developed alternative in vitro detection methods and assess their ability to supplement or replace the mouse bioassay in the analysis of complex matrix samples.

Measurement of melatonin in alcoholic and hot water extracts of Tanacetum parthenium, Tripleurospermum disciforme and Viola odorata

BACKGROUND AND THE PURPOSE OF THE STUDY

Melatonin has recently been found in several plant tissues. Some reports show that the majority of the herbs containing the high level of melatonin have been used traditionally to treat neurological disorders or diseases associated with the generation of free radicals. Current study was undertaken to screen some medicinal plant species with historical evidence of efficacy in the treatment of neurological and antioxidant deficiency related disorders for their melatonin content. The melatonin content of boiled and alcoholic extracts were also compared.

METHODS

In this study, three medicinal herbs, Tanacetum parthenium (L.) Schultz. Bip. (Asteraceae), Tripleurospermum disciforme (C.A.Mey) Schultz. Bip. (Asteraceae) and Viola odorata (L.) (Violaceae) were analyzed using high performance liquid chromatography with ultraviolet detector (HPLC-UV), enzyme linked immunosorbent assay (ELISA) and thin layer chromatography (TLC).

RESULTS

Melatonin content in the dry plant powders differed with different assay methods (p < 0.001). For example, the melatonin content in T. disciforme was determined as 3.073 µg/g and 2.906 µg/g by the HPLC and the ELISA methods, respectively.

MAJOR CONCLUSION

The results demonstrated that a hydroalcoholic solution could extract more melatonin from flowers of the herbs than hot water (p < 0.001). The presence of melatonin in these plant tissues may provide some explanation for the anecdotal evidence of their physiological effects in humans.

Sensing the deadliest toxin: technologies for botulinum neurotoxin detection

Sensitive and rapid detection of botulinum neurotoxins (BoNTs), the most poisonous substances known to date, is essential for studies of medical applications of BoNTs and detection of poisoned food, as well as for response to potential bioterrorist threats. Currently, the most common method of BoNT detection is the mouse bioassay. While this assay is sensitive, it is slow, quite expensive, has limited throughput and requires sacrificing animals. Herein, we discuss and compare recently developed alternative in vitro detection methods and assess their ability to supplement or replace the mouse bioassay in the analysis of complex matrix samples.

Production and characterization of mouse monoclonal antibodies recognizing multiple subclasses of human IgG

Different IgG subclass profiles are produced in response to different antigenic stimuli in a variety of diseases. IgG subclass levels may reflect disease severity. Quantification of IgG subclasses depends on the availability of specific Monoclonal antibodies (MAbs). In the present study seven hybridoma clones producing MAbs reactive with multiple subclasses of human IgG were established. Splenocytes from Balb/c mice immunized with Fc fractions of human IgG1 or IgG2 myeloma proteins were fused with mouse myeloma cells. Fused cells were selected and cloned by limiting dilution assay. Antibody secreting cells were screened by Enzyme-linked immunosorbent assay (ELISA) and the specificity of secreted MAbs was further analyzed, using a panel of purified human myeloma paraproteins of different IgG subclasses by ELISA and immunoblotting. Cross-reactivity to immunoglobulins (Igs) of other species was studied by indirect ELISA using serum samples collected from 9 animals. The MAbs were found to react with triple IgG subclasses, including IgG1,2,4 (n=4) and IgG1,2,3 (n=3). Immunoblotting studies revealed recognition of linear (n=4) or conformational (n=3) epitopes by these MAbs. The most abundant cross-reactivity (71.4%) was observed with monkey Ig while no cross-reactivity was detected with hen and cat sera. The MAbs mostly displayed a restricted pattern of cross-reactivity and one of them did not bind to any of the animal sera tested. The affinity constant of 3 MAbs was measured by ELISA. Based on the data obtained from this study, mouse MAbs reactive with multiple human IgG subclasses are directed to a variety of immunogenic epitopes, mostly shared with IgG of other species. These MAbs are valuable tools for purification of non-reactive IgG subclasses through negative affinity chromatography. These MAbs could also provide an opportunity for epitope mapping of the Fc region of IgG, as well as serological phylogenetic studies.

Development of a sensitive enzyme-linked immunosorbent assay for detection of hepatitis B surface antigen using novel monoclonal antibodies

Hepatitis B virus (HBV) infection is the 10th leading cause of death worldwide. The most important diagnostic and screening marker for HBV infection is Hepatitis B surface antigen (HBsAg), and the most widely used HBsAg screening test is Enzyme-linked Immunosorbent Assay (ELISA). In this study, an ELISA assay has been developed for detection of HBsAg using two novel monoclonal antibodies (mAb) as capture layer and a polyclonal biotinylated Ab as detector phase. We evaluated the sensitivity, specificity, detection limit, seroconversion time, positive and negative predictive values and reproducibility of our assay with standard panels and different serum samples. The results were compared with a well established commercial kit. Both assays showed similar detection limit values of 0.5 to 0.7 ng/ml and the same seroconversion periods of 42 and 65 days for "ad" and "ay" serotypes of HBsAg, respectively. Sensitivity and specificity of the assay were 98.98% and 99.6%, respectively. The positive and negative predictive values of our assay were also calculated as 99.49% and 99.2%, respectively. Analysis of reproducibility of the present assay demonstrated 3.96% and 5.85% intra-and inter-assay coefficient of variations, respectively, which were less than those obtained by the commercial kit. There was a highly significant correlation between our designed assay and the commercial ELISA kit (p < 0.0001, r = 0.957). Altogether, our results indicate that the designed assay is comparable to the commercial kit in terms of sensitivity, specificity, positive and negative predictive values and reproducibility and could be employed for diagnosis of HBV infection in blood samples.

Analysis of clinical assessment data for a hepatitis E virus antibody test kit

AIM: To evaluate the quality and possible uses of a hepatitis E virus (HEV) antibody test kit.

METHODS: The kit evaluated (HEV antibody test kit; Dia.Pro Diagnostic Bioprobes Srl, Italy), reference kit (HEV antibody test kit; Wantai Biological Pharmacy, Beijing, China) and a third-party kit were used to detect 450 serum samples taken from individuals undergoing routine physical examination and those potentially infected with HEV. Statistical analysis was then performed to evaluate the test data obtained.

RESULTS: The coincidence rates of positive and negative results and the total coincidence rate between the evaluated kit and the reference kit were 98.35%, 99.70% and 99.33%, respectively. A sample that showed inconsistent results between the evaluated kit and the reference kit was subjected to confirmation test using the third-party kit. The results demonstrated that the evaluated kit had a sensitivity of 99.17% and a specificity of 100%.

CONCLUSION: Combined detection of HEV antibody (IgG+IgM) in the serum of patients can improve the detection rate of HEV.

Seroepidemiology of Bordetella pertussis infections in the twin cities of Pakistan

BACKGROUND

Bordetella pertussis is the cause of whooping cough occurring mainly in children. The prevalence of this disease has been reduced largely due to worldwide mass vaccination with DTP vaccine. However, the immunity produced by the vaccination wanes by the passage of time. Still this disease kills around 2-4 million children annually. Adults may be a source of infection for infants and children. Furthermore, Bordetella pertussis has also been found to be associated with cases of persistent cough in adults in many countries.

AIM

The aim of this study was to study the exposure of the adult population to the Bordetella pertussis by detecting IgG antibodies.

MATERIALS AND METHODS

We performed Seroepidemiology of Bordetella pertussis infections in multiethnic twin cities of Pakistan (Rawalpindi and Islamabad) using a commercially available ELISA kit to have a picture of epidemiology of Bordetella pertussis in Pakistan. We targeted adults of age between 18-45 years (mean age 29.64 years).

RESULTS

The results of our study show a high percentage of seropositivity to Bordetella pertussis (89 percent), which indicates higher exposure to this organism and risk of infection to infants, children, adolescents and adults.

CONCLUSION

A high percentage of seropositive individuals are alarming to health care professionals as well as policy makers. Bordetella pertussis infections may be associated with their atypical manifestation in Pakistan. Adult vaccination with DTP is recommended to reduce the risk of infection in infants and children through adult reservoirs.

Evaluation of two ELISA and two indirect hemagglutination tests for serodiagnosis of pulmonary hydatid disease

To establish a definite diagnosis for pulmonary hydatid disease, combination of radiology and serology is useful. In this study, 19 preoperative sera from patients with surgically confirmed pulmonary hydatidosis, 40 sera from patients with other parasitosis and pulmonary diseases, and 20 sera from healthy donors were evaluated using 4 different serological tests, i.e., the commercial ELISA (ELISA-kit) test, the ELISA (ELISA-lab) test prepared in our laboratory, the commercial indirect hemagglutination assay kit (IHA-kit) test, and the IHA test using sensitized sheep red blood cells with tannic acid (IHA-TA). The ELISA-kit was the most sensitive (84.2%) and the most specific test (100.0%). The ELISA-kit also demonstrated the highest positive (100.0%) and negative (95.2%) predictive values. The sensitivity of the ELISA-lab test, that we prepared, was found to be 73.6%, whereas the IHA-kit test and the IHA-TA test were found to be 73.6% and 68.4%, respectively. The specificity of these tests was 96.6%, 98.3%, and 83.3%, respectively. When all 4 tests were assessed together, it was found that the sensitivity had risen to 94.7%. When the ELISA-kit was assessed with the IHA-kit and IHA-TA together, it was found that the sensitivity was 89.5% and 84.2%, respectively. Likewise, the combination of the ELISA-lab and IHA-kit or IHA-TA allowed us to achieve a sensitivity of 84.2% in cases of pulmonary echinococcosis. In conclusion, the diagnosis would be imminent if least 2 tests were applied together.

LOCALIZATION OF MICROCYSTIN SYNTHETASE GENES IN COLONIES OF THE CYANOBACTERIUM MICROCYSTIS USING FLUORESCENCE IN SITU HYBRIDIZATION(1)

To better understand the production of microcystins (MCs) in Microcystis colonies, fluorescence in situ hybridization (FISH) methods were developed to detect DNA involved in the synthesis of these cyanobacterial hepatotoxins. Using colonies of Microcystis aeruginosa (Kütz.) Kütz. isolated from environmental blooms of cyanobacteria and from a colony-forming, MC-producing laboratory strain of Microcystis, amplified PCR products were observed, coincident with positive controls. The total MC content of individual colonies of Microcystis, determined by ELISA, showed a positive correlation with colony cross-sectional area. FISH analysis of Microcystis colonies gave high fluorescence in comparison to negative controls, indicating the presence of MC synthetase DNA (mcyA) in situ. FISH analysis for MC synthetase genes has the potential to be developed into an effective early warning tool for drinking and recreational water management.

Soluble and membranous vascular endothelial growth factor receptor-2 in pregnancies complicated by pre-eclampsia

PURPOSE

There is a paucity of information on the serum soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) concentrations, membranous VEGFR-2 expression and the mechanism involved in their modulations during the clinical onset of pre-eclampsia. This cross-sectional study was conducted to evaluate the concentration of sVEGFR-2 in serum and to investigate the expression of membranous VEGFR-2 in placentae of pre-eclampsia group.

MATERIALS AND METHODS

The serum levels of sVEGFR-2 (n = 120) and the expression of membranous VEGFR-2 in placentae (n = 100) were analysed at third trimester of pregnancy by enzyme linked immunosorbent assay (ELISA) and immunohistochemistry respectively. The diagnostic parameters of sensitivity, specificity and association of soluble and membranous VEGFR-2 in these patients were evaluated.

RESULTS

The serum levels of sVEGFR-2 in pre-eclampsia patients were found to be significantly reduced (p = 0.01, p = 0.001) in early and late pre-eclamptic sub-groups as compared to their respective third trimester control sub-groups. Also, the receiver operating characteristic (ROC) curve analysis showed a cut-off value of 7350.4 pg/mL, higher sensitivity (76%) and specificity (76%) for sVEGFR-2 in late onset (> 34 weeks) pre-eclamptic group. Significant down-regulation of membranous VEGFR-2 immunoreactivity was observed in all the placental cells (p = 0.0001) at > 34 weeks preeclamptic group.

CONCLUSION

The reduced serum levels of soluble VEGFR-2 and the down-regulated expression of membranous VEGFR-2 in the study group denoted abnormality in VEGF mediated placental function in all placental cells and thus VEGFR-2 may be a key factor, intimately associated with pre-eclampsia. This study shows the clinical utility of soluble and membranous VEGFR-2 in pre-eclampsia patients.

Quantification of natural populations of Gluconacetobacter diazotrophicus and Herbaspirillum spp. In sugar cane (Saccharum spp.) Using differente polyclonal antibodies

The species Gluconacetobacterdiazotrophicus, Herbaspirillum seropedicae and H. rubrisubalbicans are endophytic N₂-fixing [diazotrophic] bacteria which colonise not only roots, but also the aerial tissue of sugar cane. However, the technique most commonly used to quantify the populations of these microbes in plants is by culturing serial dilutions of macerates of plant tissues in N free semi-solid media which are only semi-selective for the species/genera [the Most Probable Number (MPN) Technique] and each culture must be further subjected to several tests to identify the isolates at the species level. The use of species-specific polyclonal antibodies with the indirect ELISA (enzyme-linked immunosorbent assay) can be an alternative which is rapid and specific to quantify these populations of bacteria. This study was performed to investigate the viability of adapting the indirect ELISA technique to quantify individually the populations of these three species of diazotroph within the root and shoot tissues of sugarcane. The results showed that species-specific polyclonal antibodies could be obtained by purifying sera in protein-A columns which removed non-specific immuno-globulins. It was possible to quantify the three bacterial species in the Brazilian sugarcane variety SP 70-1143 in numbers above 10⁵ cells per g fresh weight in roots, rhizomes and leaves. The numbers of the different bacterial species evaluated using the ELISA technique were found to be higher than when the same populations were evaluated using the MPN technique, reaching 1400 times greater for G. diazotrophicus and 225 times greater for Herbaspirillum spp. These results constitute the first quantification of Herbaspirillum using immunological techniques.

A hospital-based serological survey of cryptosporidiosis in the Republic of Korea

The seroprevalence of cryptosporidiosis was examined using patients' sera collected from hospitals located in 4 different areas of the Republic of Korea. ELISA was used to measure antibody titers against Cryptosporidium parvum antigens from a total of 2,394 serum samples, which were collected randomly from patients in local hospitals; 1) Chungbuk National University Hospital, 2) Konkuk University Hospital, 3) local hospitals in Chuncheon, Gangwon-do (province), 4) Jeonnam National University Hospital, from 2002 through 2003. Of the 2,394 samples assayed, 34%, 26%, and 56% were positive for C. parvum-specific IgG, IgM, and IgA antibodies, respectively. Positive IgG titers were most common in sera from Jeonnam National University Hospital, Gwangju, Jeollanam-do, and positive IgM titers were most common in sera from Chungbuk National University Hospital, Cheongju, Chuncheongbuk-do. The seropositivity was positively correlated with age for both the IgG and IgA antibodies but was negatively correlated with age for the IgM antibodies. Western blotting revealed that 92%, 83%, and 77% of sera positive for IgG, IgM, and IgA ELISA reacted with 27-kDa antigens, respectively. These results suggested that infection with Cryptosporidium in hospital patients occurs more commonly than previously reported in the Republic of Korea.

Diagnostic sensitivity of enzyme-linked immunosorbent assay for IgG in hydatid disease

CONTEXT

Hydatid disease in humans is most commonly caused by Echinococcus granulosus and results in development of cysts in various organs of body. The diagnosis is made by serology i.e. by estimation of antibody levels or on imaging studies. Enzyme-linked immunosorbent assay (ELISA) is widely used for serological confirmation of the disease.

AIM

To study the sensitivity of ELISA for IgG antibodies against E. granulosus in detecting hydatid disease of liver or lung.

SETTINGS

A retrospective study of serology of all surgically confirmed cases of hydatid cysts of liver or lung in a tertiary level hospital.

METHODS AND MATERIAL

The levels of IgG antibodies against Echinococcus, measured by ELISA, in patients of cystic lesions of liver or lung, who underwent surgery for the same and confirmed as having hydatid disease, during surgery or on histopathological examination after surgery, were recorded and analysed. There were 28 such patients from January 2001 to 2007. Twenty-three patients with hydatid cysts in liver and 4 in lung were included. One patient with hydatid liver was excluded from the study due to heavily calcified cyst.

RESULTS

Two types of kits were used; one using crude antigen and other using purified antigens. Among 23 patients with hydatid cysts of liver, 8 had positive serology while 15 had either equivocal or negative results. All 4 patients with hydatid of lung had positive serology.

CONCLUSION

ELISA test is not sensitive enough to be relied upon for confirmation of hydatid disease and considering its high cost, an alternative more specific, sensitive, cheaper and easily available test needs to be evaluated for confirming hydatid disease.

Blood Meal Identification in Field-Captured Sand flies: Comparison of PCR-RFLP and ELISA Assays

BACKGROUND

We aimed to develop a PCR-RFLP assay based on available sequences of putative vertebrate hosts to identify blood meals ingested by field female sand fly in the northwest of Iran. In addition, the utility of PCR-RFLP was compared with ELISA as a standard method.

METHODS

This experimental study was performed in the Insect Molecular Biology Laboratory of School of Public Health, Tehran University of Medical Sciences, Iran in 2006-2007. For PCR-RFLP a set of conserved vertebrate primers were used to amplify a part of the host mitochondrial cytochrome b (cyt b) gene followed by digestion of the PCR products by Hae III enzyme.

RESULTS

The PCR-RFLP and ELISA assays revealed that 34% and 27% of field-collected sand flies had fed on humans, respectively. Additionally, PCR-RFLP assays could reveal specific host DNA as well as the components of mixed blood meals. Results of PCR-RFLP assay showed that the sand flies had fed on cow (54%), human (10%), dog (4%), human and cow (21%), dog and cow (14%), and human and dog (3%).

CONCLUSION

The results can provide a novel method for rapid diagnosis of blood meal taken by sandflies. The advantages and limitations of PCR and ELISA assays are discussed.

HCV antibody response and genotype distribution in different areas and races of China

Hepatitis C virus (HCV) heterogeneity accounts for the failure of effective vaccine development and the lack of successful anti-viral therapy in some patients. Little is known about the immune response to HCV peptides and the region or race specific genotypes in China. The objective of this study was to characterize HCV antibody immune response to HCV peptides and HCV genotypes in different regions and races of China. A total of 363 serum samples were collected from HCV carriers in 6 regions in China. The immune response to HCV peptides was evaluated by ELISA. HCV genotypes were examined using nested RT-PCR. We found that the anti-HCV antibody neutralization rates were significantly different among the serum samples from different areas or from different races in the same area. For samples from Tibet and Sinkiang, the rates of neutralization by HCV peptides were only 3.2% and 30.8%, respectively. The genotypes of samples from Tibet and Sinkiang were apparently heterogeneic and included type I, II, III and multiple types (I/II/III, I/II, I/III, II/III). One specific sample with multiple-genotype (I/II/III) HCV infection was found to consist of type I, II, III, II/III and an unclassified genotype. These studies indicate that the anti-HCV antibody immune response to HCV peptides varied across regions and among races. The distribution of HCV genotypes among Tibetans in Tibet and Uighurs in Sinkiang was different from that in the inner areas of China. In addition, a "master" genotype, type II, was found to exist in HCV infection with multiple HCV genotypes.

Serum antigen and antibody detection in echinococcosis: application in serodiagnosis of human hydatidosis

Diagnosis of hydatidosis is based on immunodiagnostic methods along with radiological and ultrasound examinations. The objectives of the present study were to develop a specific and simple antigen-based ELISA method for diagnosis of hydatidosis and compare it with antibody detection method. The subjects in this study included 89 patients in the following groups: surgically confirmed hydatidosis patients (35 cases), control with other parasitic diseases (29 cases), and healthy controls (25 cases). Hyperimmune serum was raised against hydatid cyst fluid in rabbits. Anti-hydatid cyst IgG was purified by affinity chromatography using protein A column and labeled with horseradish peroxidase. Collected sera were assessed for hydatid cyst antigens and antibody by ELISA. Circulating hydatid antigen was found in 9 out of 35 patients with surgically confirmed hydatidosis. A sensitivity of 25.7% and a specificity of 98.0% were calculated for the antigen detection assay. Antibody detection by indirect ELISA, using antigen B, showed that 94.2% of patients (33 cases) have anti-hydatid cyst antibodies in their serum while cross reaction was noted in a few of non-hydatidosis patients. A sensitivity of 94.2% and specificity of 81.6% were found for the antibody detection assay. Findings of this study indicated that antibody detection assay is a sensitive approach for diagnosis of hydatid cyst while antigen detection assay might be a useful approach for assessment of the efficacy of treatment especially after removal of the cyst.

Detection of diarrheic shellfish poisoning and azaspiracid toxins in Moroccan mussels: comparison of the LC-MS method with the commercial immunoassay kit

Diarrheic shellfish poisoning (DSP) is a recurrent gastrointestinal illness in Morocco, resulting from consumption of contaminated shellfish. In order to develop a rapid and reliable technique for toxins detection, we have compared the results obtained by a commercial immunoassay-“DSP-Check” kit” with those obtained by LC-MS. Both techniques are capable of detecting the toxins in the whole flesh extract which was subjected to prior alkaline hydrolysis in order to detect simultaneously the esterified and non esterified toxin forms. The LC-MS method was found to be able to detect a high level of okadaic acid (OA), low level of dinophysistoxin-2 (DTX2), and surprisingly, traces of azaspiracids 2 (AZA2) in mussels. This is the first report of a survey carried out for azaspiracid (AZP) contamination of shellfish harvested in the coastal areas of Morocco. The “DSP-Check” kit was found to detect quantitatively DSP toxins in all contaminated samples containing only OA, provided that the parent toxins were within the range of detection and was not in an ester form. A good correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit appeared to be more sensitive, specific and faster than LC-MS for determination of DSP in total shellfish extract.

Assay validation for KIM-1: human urinary renal dysfunction biomarker

Urinary kidney injury molecule (KIM-1) is a sensitive quantitative biomarker for early detection of kidney tubular injury. The objective of the present work was to analytically validate this urinary renal injury biomarker. Duo-set reagents from R&D were used to develop the ELISA and validate the assay's linearity, intra-run precision, inter-run precision, lower limit of quantification, recovery, dilutional verification, reference range, stability, and length of run. The reference range data suggests that the healthy population falls within the assay range (59 - 2146 pg/mL) and upper limit of quantitation for this assay is 17168 pg/mL for the patient population. This is a robust assay to detect urinary levels of KIM-1, which serves as a non-invasive sensitive, reproducible, and potentially high-throughput method to detect early kidney injury in drug development studies.

SEROPREVALENCE OF ERYTHROVIRUS B19 IgG AMONG SAUDI BLOOD DONORS IN MAKKAH, SAUDI ARABIA

OBJECTIVES

To determine the seroprevalence of immunoglobulin G (IgG) to erythrovirus B19 in Saudi blood donors in Makkah. Saudi Arabia.

SUBJECTS AND METHODS

A total of 578 blood (serum) samples were tested for erythrovirus B19-specific-IgG antibody among Saudi blood donors in Makkah. Saudi Arabia.

RESULTS

Erythrovirus B19-specific-IgG antibodies were detected in 441/578 (76.3%) of Saudi blood donors of different age groups.

CONCLUSION

This study indicated that 76.3% of Saudi blood donors in Makkah city, Saudi Arabia, had been exposed to erythrovirus B19. This result is in accordance with previous studies performed in other countries.

Evaluation of immunohistochemistry and enzyme linked immunosorbent assay for HER-2/neu expression in breast carcinoma

HER-2 is overexpressed in approximately 20-30% of invasive Breast Cancer. ECD of the HER-2 protein is frequently cleaved and released into the circulation, where it can be detected by ELISA in up to 45% of patients with metastatic breast cancer. The objective of our study was to compare the current methods for the detection of HER-2 protein. Tissue HER-2 levels were studied in 100 breast cancer patients by IHC and compared with serum HER-2 levels by ELISA. IHC frequency was 29%. Serum HER-2 ECD was positive in 42% of patients. A statistically significant correlation was observed. HER-2 detected by IHC correlates significantly with serum HER-2 levels detected by ELISA. Thus, ELISA is a reliable and economical tool to assess the HER-2 status in tumors, when breast tissue sample is not available.

Occurrence of deoxynivalenol in maize and wheat in Serbia

A total of 226 samples of maize and 59 of wheat from the 2004-2007 harvests were investigated for the presence and concentration of deoxynivalenol (DON). Samples of the 2004 harvest were analyzed after their storing for one year in barns, while those of the 2005-2007 harvest were taken directly off fields immediately after the harvest. The samples were analyzed by liquid chromatography on an ODS Hypersil column with DAD detector and ELISA methods. The average incidence rate of DON in maize from the 2004 harvest was 50% (concentration range 0.042-2.460 mg/kg, average value 0.536 mg/kg), while for those of the 2005-2007 harvest it was 32.4% (concentration range 0.027-2.210 mg/kg, average value 0.223 mg/kg). In the case of wheat incidence rate of DON for 2004 harvest was 50.0% (concentration range 0.630-1.840 mg/kg, average value 1.235 mg/kg), while for those of the 2005-2007 harvest it was 34.5% (concentration range 0.057-0.423 mg/kg, average value 0.190 mg/kg). Concentrations in two samples of maize and one of wheat (one sample of each cereal being of the 2004 harvest) were above the maximum level adopted by the European Commission. The results obtained were analyzed as a function of climatic conditions and compared with those of the neighboring countries where the relevant data existed.

Qualification and application of an ELISA for the determination of Tamm Horsfall protein (THP) in human urine and its use for screening of kidney stone disease

Kidney stone disease affects 1 - 20% of the general population. At present, the diagnosis of a stone is done using radiography method when noticeable symptoms appeared. We developed a non-invasive quantitative assay for urinary THP, namely ELISA; whereby our previous study and other reports had shown the usefulness of THP as biomarker for kidney stone disease. Since urine is biological fluid that is easily obtainable, this method could be used as a screening assay for kidney stone prior to confirmation with radiography. The ELISA gave assay linearity r(2) > 0.999 within the range of 109 ng/mL to 945 ng/mL THP. Assay precisions were < 4% (C.V.) for repeatability and < 5% (C.V.) for reproducibility. Assay accuracy range from 97.7% to 101.2% at the various THP concentrations tested. Assay specificity and sensitivity were 80% and 86%, respectively. The cut-off points at P < 0.05 were 37.0 and 41.2 mug/mL for male and female, respectively. The assay is cost effective and rapid whereby the cost for assaying each urine sample in duplicate is approximately USD0.35 and within 5 hours, 37 samples can be assayed alongside full range of standards and 3 QC samples in each plate. Furthermore, sample preparation is relatively easy where urine sample was diluted 10 times in TEA buffer. The usability of the ELISA method for diagnosis of kidney stone disease is evaluated with 117 healthy subjects and 58 stone formers.

An alternative for the preadsorption step in the paratuberculosis serodiagnosis: Mycobacterium fortuitum

ELISAs for paratuberculosis employ a preadsorption step with Mycobacterium phlei to diminish unspecific reactions As M. fortuitum is one of the most frequent environmental mycobacteria, the purpose of this pilot study was to evaluate its use as an alternative for the preadsorption in ELISAs for paratuberculosis. Results suggest that M. fortuitum can be an alternative instead of or associated to M. phlei with comparable results (κ > 0.8) to conventional ELISAs using M. phlei as a preadsorption antigen.

In vitro effect of N-desulfated heparin on the expression of basic fibroblast growth factor in gastric carcinoma cell line SGC-7901

AIM: To investigate the effect of N-desulfated heparin on the expression of basic fibroblast growth factor (bFGF) in human gastric carcinoma SGC-7901 cells in vitro.

METHODS: Human gastric carcinoma cell line SGC-7901 was cultured in vitro, and then treated with N-desulfated heparin at different concentrations (0.1, 1.0 g/L). Meanwhile, SGC-7901 cells cultured in single RPMI 1640 medium were used as controls. Each group contained 3 paralleled samples. Enzyme-linked immunosorbent assay (ELISA) and real time polymerase chain reaction (PCR) were used to detect the expression of bFGF in SGC-7901 cells at 12 h and 24 h, respectively.

RESULTS: After treatment with 0.1 or 1.0 g/L N-desulfated heparin for 12 or 24 h, bFGF protein expression was decreased significantly (t = 7.502, P = 0.002; t = 55.416, P = 0.000; t = 52.221, P = 0.000; t = 48.080, P = 0.000). The expression of bFGF (CT value) in each N-desulfated heparin group was higher than that in the control group at the same time. The inhibition of N-desulfated heparin on bFGF protein and mRNA expression in SGC-7901 cells was dose- and time-dependent.

CONCLUSION: N-desulfated heparin can inhibit the expression of bFGF in gastric cancer cell line SGC-7901 in a dose- and time-dependent manner in vitro.

Diagnosing latent tuberculosis infection in the HIV era

Tuberculin skin testing (TST) and Interferon-gamma (IFNγ)release assays (IGRAs) are presently the only available assays for the detection of Mycobacterium tuberculosis infected individuals. IGRAs might progressively replace TST, as numerous published reports establish their higher specificity and similar sensitivity when tested in BCG vaccinated, immunocompetent individuals or in populations who may have been in contact with atypical mycobacteria. However, few published reports have commented on their role in TB diagnosis in immunocompromised individuals (HIV, immunosuppressive therapy, cancer…). It is the purpose of this report to review IGRAs published studies in HIV individuals in endemic and non endemic area for tuberculosis (TB). IGRAs were tested in the presence or absence of active TB but correlated to duration of exposure. In newly diagnosed active TB, IGRAs demonstrated a similar sensitivity to TST. In TB non infected individuals, TST and IGRAs also gave similar values when categorization of individuals was correlated to the risk of infection. A higher number of positive IGRAs was observed in individuals from TB endemic areas, in similar proportions to immunocompetent individuals. Comparison between the two IGRAs: QuantiFERON-TB Gold^® (QF-TB, Cellestis, Australia) and T-SPOT-TB^® (Oxford Immunotec, UK), and against TST, in the same HIV population demonstrates a higher sensitivity of T-SPOT-TB and TST than QF-TB. Indeterminate results, which correspond to the absence of a positive T-cell IFNγ response towards phytohemaglutinin (PHA), is a key point when comparing both IGRAs. This PHA control is indicative of the level of immunosuppression observed in the tested individual. QF-TB seems to present, in HIV populations, more indeterminate results than T-SPOT-TB. The calibration and/or concentration of PBMC on nitrocellulose membrane for the T-SPOT-TB, as compared to a whole blood assay, might explain this difference, with less indeterminate results with the T-SPOT-TB assay. Neither assay is able to differentiate active TB from latent TB infection (LTBI). Several laboratories have tried new antigenic epitopes to solve this issue. It is of importance that these studies need to be repeated on a larger scale by others to validate their results. Two blood assays might add information characterising the evolution from LTBI to active TB: either by losing protective immunity, as demonstrated by the whole blood killing assay, or by evaluating the kinetics of the antibodies synthesized against M. tuberculosis specific antigens. In conclusion, longitudinal studies are still needed to validate IGRAs and other assays and to define their respective predictive values.

Non-invasive diagnosis of H pylori infection: Evaluation of serological tests with and without current infection marker CIM

AIM: To evaluate the performance of commercially available immunochromatographic (ICT) and immunoblot tests covering the current infection marker CIM and conventional ELISA for the diagnosis of H pylori infection in adult dyspeptic patients.

METHODS: Consecutive non-treated dyspeptic patients undergoing diagnostic endoscopy were tested for H pylori infection by culture, rapid urease test, and histology of gastric biopsy specimens. Serum from 61 H pylori infected and 21 non-infected patients were tested for anti-H pylori IgG antibodies by commercial ELISA (AccuBind^TM ELISA, Monobind, USA), ICT (Assure^®H pylori Rapid Test, Genelabs Diagnostics, Singapore), and immunoblot (Helico Blot 2.1, Genelabs Diagnostics, Singapore) assays. ICT and immunoblot kits cover CIM among other parameters and their performance with and without CIM was evaluated separately.

RESULTS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of ELISA were 96.7%, 42.8%, 83.1%, 81.8%, and 82.9%, of ICT were 90.1%, 80.9%, 93.2%, 73.9%, and 87.8%, of ICT with CIM were 88.5%, 90.4%, 96.4%, 73.0%, and 89.0%, of immunoblot were 98.3%, 80.9%, 93.7%, 94.4%, and 93.9%, and of immunoblot with CIM were 98.3%, 90.4%, 96.7%, 95.0%, and 96.3%, respectively.

CONCLUSION: Immunoblot with CIM had the best performance. ICT with CIM was found to be more specific and accurate than the conventional ELISA and may be useful for non-invasive diagnosis of H pylori infection.

Effects of micron rhubarb charcoal on the platelet function and fibrinolytic activity in rats

AIM: To study the effects of micron rhubarb charcoal on platelet function and fibrinolytic activity in rats.

METHODS: SD rats were divided into control group, Yunan Baiyao group[0.9 g/(100 g·d)] and high [0.8 g/(100 g·d)], normal [0.4 g/(100 g·d)]and low [0.2 g/(100 g·d)] micron rhubarb charcoal dosage groups(ig for six days). The effects of micron rhubarb charcoal on platelet aggregation, TXB₂, 6-keto-PGF_1α and the activity of tissue fibrinolytic activating factor (t-PA) and its inhibitors (PAI-1) in SD rats were studied.

RESULTS: Compared with normal rats treated with Yunan Baiyao, the platelet aggregation and TXB2 level were increased while the 6-keto-PGF1α level was decreased in rats treated with micron rhubarb charcoal (P < 0.05), suggesting that high micron rhubarb charcoal dosage had a better effect than Yunan Baiyao on platelet function and fibrinolytic activity in rats (64.19% ± 8.79% vs 56.82% ± 4.78%, 273.35 ± 24.86 ng/L vs 238.35 ± 47.30 ng/L, 15.21 ± 2.71 mg/L vs 13.12 ± 3.09 mg/L, P < 0.05). However, micron rhubarb charcoal had no effect on the activity of t-PA and its inhibitor PAI.

CONCLUSION: Micron rhubarb charcoal regulates platelet aggregation by decreasing the level of TXB2 and 6-Keto-PGF1α and its effects on hemostasia are better than Yunan Baiyao.

Heparanase levels are elevated in the plasma of pediatric cancer patients and correlate with response to anticancer treatment. Neoplasia. 2007;9:909-916. [PMID: 18030359 DOI: 10.1593/neo.07673]

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate (HS) side chains of heparan sulfate proteoglycans, the major proteoglycan in the extracellular matrix (ECM) and cell surfaces. Heparanase upregulation was documented in an increasing number of primary human tumors, correlating with reduced postoperative survival rate and enhanced tumor angiogenesis. The purpose of the current study was to determine heparanase levels in blood samples collected from pediatric cancer patients using an ELISA method. Heparanase levels were elevated four-fold in the plasma of cancer patients compared with healthy controls (664 +/- 143 vs 163 +/- 18 pg/ml, respectively). Evaluating plasma samples following anticancer therapy revealed reduced heparanase levels (664 +/- 143 vs 429 +/- 82 pg/ml), differences that are statistically highly significant (P = .0048). Of the 55 patients with complete remission (CR) or very good partial remission (VGPR) at restaging, 41 (74.5%) had lower heparanase amounts, whereas 14 patients (25.5%) had similar or higher amounts of plasma heparanase. All nine patients with stable or advancing disease had similar or elevated levels of heparanase on restaging. The results show that heparanase levels are elevated in the plasma of pediatric cancer patients and closely correlate with treatment responsiveness, indicating that heparanase levels can be used to diagnose and monitor patient's response to anticancer treatment.

Neonatal Screening Programme for Increasing Early Postnatal Diagnosis of Congenital Cytomegalovirus Infection in the West Poland Province

Congenital infection with cytomegalovirus (CMV) is the main cause of sensorineural hearing loss and psychomotor impairment which can develop at birth or later in infant's life. Because of a lack of nation-wide serological screening for pregnant women and accepted antiviral therapy during pregnancy in a high seroprevalence rate population of Poland, we introduced the regional screening programme for CMV infection in neonates from the Poznan Province to diminish a risk of the symptomatic disease. The aims of the study were: (i) to determine the prevalence of specific anti-CMV antibodies in populations of pregnant women and newborns from the Poznan area, (ii) to increase the early postnatal detection of congenital CMV infections, and (iii) to evaluate a risk of perinatal or early postnatal infections with CMV in newborns or infants born to seropositive mothers. Serological testing was performed in 4.192 live born neonates, using dried blood filter-paper specimens. The seropositivity rate in the studied population of neonates and pregnant women was 78.6%. The incidence of perinatal and early postnatal CMV infections was evaluated to be 3.1% or 1 per 25 neonates born to seropositive mothers. Congenital CMV infections confirmed by a presence of specific IgM antibodies were diagnosed in 5 newborns, which represent 1 case per 838 successive deliveries. In a clinical pattern of cytomegalovirus disease respiratory disorders and low birth weight were most frequently observed, and neurological signs, hepatitis, haemorrhagies or jaundice were sporadically diagnosed. Implementation of mass immunodiagnostic screening for congenital CMV infection, combined with other obligatory neonatal tests for metabolic errors, congenital malformations and endocrine disorders seems to be a valuable third line prophylactic strategy to prevent a late development of clinically overt cytomegalovirus disease.

The Sample Type used Affects the Levels of Gelatinases (MMP-2 and -9) and their Inhibitors (TIMP-1 and -2) in Circulating Blood of Healthy Controls and Breast Cancer Patients

New potential tumor markers such as matrix metalloproteinases and their inhibitors have been extensively studied during the last decades. The aim is to find prognostic markers that are measurable in easily available samples, such as serum or plasma. The proper sample type to use when measuring the levels of gelatinases and their inhibitors from blood samples is currently under critical evaluation. In this study, the effect of sample type is studied in 26 healthy controls, and the result is confirmed in a series of 80 breast carcinoma patients.Sample type had the most evident effect on the levels of TIMP-1 and MMP-9. Serum samples gave about two-fold levels of TIMP-1 compared to plasma samples (p < 0.001), with a strong linear correlation between these two (r = 0.79). Pro-MMP-9 levels were significantly affected by the presence of a blood coagulation activator in the serum sample, or a different anticoagulant in the plasma sample. The serum and plasma values had only a weak correlation (r = 0.37).In conclusion, sample type should be carefully considered, especially when measuring proMMP-9, and plasma should be preferred for this measurement. For TIMP-1 the correlation of serum and plasma values is good; the use of serum samples can therefore be justified as long as the generally higher levels in the serum are acknowledged.

Immunochromatographic assay for simple and rapid detection of Satsuma dwarf virus and related viruses using monoclonal antibodies

A simple and rapid immunochromatographic assay (ICA) to detect Satsuma dwarf virus (SDV) was developed using colloidal gold conjugates of anti-SDV monoclonal antibodies. Of six homogenization buffers tested, 0.1 M citrate buffer (pH 7.0) gave the best results for the ICA. In the ICA, addition of 0.1% thioglycolic acid in the homogenization buffers that have been widely used in enzyme-linked immunosorbent assays (ELISA) was deleterious to the reaction because of undesirable coagulation of the colloidal gold. ICA using the anti-SDV monoclonal antibodies was 8 times and 16 times more sensitive than double antibody sandwich-ELISA and ICA using the anti-SDV polyclonal antibody, respectively. The analysis is complete in only 15 min. Furthermore, ICA using the anti-SDV monoclonal antibodies could also detect SDV-related viruses.

Prevalence of antibodies to human parvovirus b19 in saudi women of childbearing age in makkah

OBJECTIVES

To determine the seroprevalence rate of immunoglobulin G (IgG) and immunoglobulin M (IgM) to parvovirus B19 in pregnant Saudi women in Makkah.

SUBJECTS AND METHODS

Using enzyme-linked immunosorbent assay (ELISA), a total of 1200 serum samples were tested for antibodies to parvovirus B19 known to cause a variety of clinical syndromes in women and newborn infants.

RESULTS

Parvovirus B19 IgG antibodies detected in 46.6% and IgM antibodies were found in 2.25% of different age groups.

CONCLUSION

The previous exposure to parvovirus B19 was determined, and 560 (46.6%) of 1200 pregnant Saudi women tested at their first antenatal visit were seropositive for specific IgG. The rate of maternal infection in susceptible pregnancies was 2.25%. These results were in accordance with previous studies performed in other countries.