الملخص
Aim: To evaluate the use of proliferating cell nuclear antigen index in the different histopathological variants of ameloblastoma, such as the follicular, plexiform, and unicystic types, and in ameloblastic carcinoma by immunohistochemical staining. The proliferating cell nuclear antigen index values of the variants of ameloblastomas and ameloblastic carcinomas are compared in order to determine the biological behavior of these tumors. Materials and Methods: For the present study, archival tissues that had been diagnosed as ameloblastoma and ameloblastic carcinoma were collected from the department of oral pathology. Specimens were embedded in paraffin wax and were sectioned at a thickness of 5 μm and stained with hematoxylin-eosin for reconfirming the histologic pattern. It was also stained immunohistochemically for anti-proliferating cell nuclear antigen antibody. Results: Positive proliferating cell nuclear antigen expression is seen as a light brown, granular stain. The proliferating cell nuclear antigen values of ameloblastic carcinoma were almost five times the value of ameloblastoma. Analysis of variance test, Fischer's exact test/variance ratio test, and Student's t-test were performed and the probability values were determined. Summary and Conclusion: This study showed that ameloblastic carcinoma had the maximum proliferative capacity. Among the variants of ameloblastoma, the plexiform variety had the maximum proliferative capacity, followed by the follicular and unicystic varieties. Altogether, these data indicate that proliferating cell nuclear antigen is related to the biological behavior and proliferation of tumor cells in the variants of ameloblastoma and ameloblastic carcinoma.
الموضوعات
Ameloblastoma/classification , Ameloblastoma/pathology , Antibodies, Monoclonal/diagnosis , Cell Nucleus/pathology , Chromogenic Compounds/diagnosis , Coloring Agents/diagnosis , Humans , Immunohistochemistry , Odontogenic Tumors/classification , Odontogenic Tumors/pathology , Proliferating Cell Nuclear Antigen/analysis , Biomarkers, Tumor/analysisالملخص
Background: Pediatric acute lymphoblastic leukemia (ALL) is a biologically heterogeneous disease and socioeconomic and environmental factors are considered to be an important determinant of its immunophenotype. The aim of this analysis is to study the time trend in the immunophenotype of pediatric acute lymphoblastic leukemia (ALL) cases in our geographic setting. Materials and Methods: A total of 639 new pediatric ALL cases immunophenotyped during 1989-2009 forms the basis of this analysis. Representative bone marrow or peripheral blood of these patients was immunophenotyped flowcytometrically using an extensive panel of monoclonal antibodies. Results: During early phase of our study we noticed a relative excess of T-ALL and a paucity of common acute lymphoblastic leukemia (C-ALL) in contrast to western data. Over a period of 20 years we witnessed a gradual reduction in pediatric T-ALL cases and a proportionate increase in C-ALL cases. Conclusion: We find that this change of pattern is synchronizing with the socioeconomic and industrial development prevailing in our geographic setting and suggest a possible link between the predominant immunophenotype of pediatric ALL cases and the environmental and socioeconomic factors prevailing in that locality.
الموضوعات
Adolescent , Antibodies, Monoclonal/diagnosis , Child , Child, Preschool , Disease-Free Survival , Female , Flow Cytometry , Humans , Immunophenotyping/methods , Incidence , India/epidemiology , Male , Neprilysin/blood , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/epidemiology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/epidemiology , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/immunologyالملخص
BACKGROUND: The human polyoma virus, also known as the JC virus (JCV), replicates predominantly in the oligodendrocytes, the myelin producing cells in the central nervous system and results in the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML) especially in immunosuppressed patients with AIDS. Several investigators have also documented the presence of the viral genome and early and late antigens in a variety of brain tumors particularly in medulloblastomas, gliomas and ependymomas. Reports also indicate the presence of JCV in patients with colon cancer. The T antigen of JCV has been postulated to have oncogenic potential as substantiated by animal experiments. Although JCV infects 80% of the population, there are scant epidemiological studies regarding JCV from India. There are also reports of the low prevalence of PML in patients with AIDS from India and Africa. AIM: This study was undertaken to investigate if Indian children with medulloblastomas also show evidence of JCV. METHODS: Twenty-two consecutive cases of medulloblastomas were investigated for the presence of T antigen and agnoprotein of JCV in biopsy specimens by immunohistochemistry. Antibodies to the agnoprotein antigen raised in rabbits and a monoclonal antibody against SV40 T antigen raised in mice that cross-reacts with JCV T antigen were used. RESULTS: Out of 22 patients, 4 had desmoplastic tumors while the rest had classical tumors. All children were below the age of 10. Results indicate that while PML tissues showed consistent immunostaining both with antibody to T antigen and agnoprotein antibody, none of the tumors showed any positive staining for JC viral antigens. CONCLUSION: JCV antigens could not be detected by immunohistochemistry in the tumor tissues of Indian children with medulloblastomas.
الموضوعات
Animals , Antibodies, Monoclonal/diagnosis , Antibodies, Viral/diagnosis , Antigens, Polyomavirus Transforming/analysis , Biopsy , Brain/pathology , Child , Child, Preschool , Humans , Immunohistochemistry , India , JC Virus/chemistry , Mice , Rabbits , Viral Regulatory and Accessory Proteins/analysisالملخص
The histological differentiation of Hepatocellular carcinoma (HCC) from cholangiocarcinoma (CC) and metastatic adenocarcinoma (MA) of the liver is difficult in some cases and immunohistochemistry (IHC) is necessary for the diagnosis. HepPar-1 is a recently available antibody which seems to be very specific and sensitive for the diagnosis of HCC. MOC31 is an antibody directed against a cell surface glycoprotein and has been shown to be helpful in distinguishing between HCC and CC or MA as a negative marker in HCC. In this study we tried to apply these two markers for the diagnosis of HCC cases as a simple, useful and reliable panel. We selected 101 liver tumors which had proven diagnosis by several antibodies and cilinicopathologic correlation. The tumors with confirmed histologic diagnosis including 35 HCC, 58 MA, 7 CC and 1 combined HCC-CC.. HepPar-1 was positive in 30 of 35 cases of HCC; none of the other tumors were reactive for HepPar1 except for a case of metastatic gall bladder adenocarcinoma which showed areas of hepatoid differentiation in the H&E slides. MOC31 was positive in 5 of the HCC cases and stained 60 of 65 cases of MA. There were 4 cases of HCC with clear cell morphology, in most of which, IHC pattern was not diagnostic and further investigation was needed. As a conclusion the combination of positive Hepar1 and negative MOC31 is highly suggestive for HCC except for the clear cell variant. These two reliable markers are recommended for the initial step of differential diagnosis between HCC and MA and for the confirmation of the histologic diagnosis.
الموضوعات
Adenocarcinoma/diagnosis , Adult , Aged , Antibodies, Monoclonal/diagnosis , Carcinoma, Hepatocellular/diagnosis , Cholangiocarcinoma/diagnosis , Diagnosis, Differential , Humans , Immunohistochemistry , Liver Neoplasms/diagnosis , Membrane Glycoproteins/immunology , Middle Aged , Biomarkers, Tumor/immunologyالملخص
OBJECTIVE: We tested the hypothesis that inducible nitric oxide synthase (iNOS) modulates angiogenesis in human models and this information could be extrapolated in elucidating the pathophysiology of oral submucous fibrosis (OSF). A hypothesis which looks inadequate, but is deep rooted in literature is the epithelial alteration ("atrophy") seen in OSF and the events that lead to its causation. This aspect was tried to be addressed and an alternative pathogenetic pathway for the disease is proposed. MATERIALS AND METHODS: This immunohistochemical study sought to investigate the expression of iNOS in OSF samples (n=30) a using monospecific antibody (SC- 2050, Santa Cruz Biotechnology, Inc) to the protein and also to correlate it with different grades of epithelial dysplasia associated with the disease. Twenty (20) healthy adults acted as controls. RESULTS: iNOS staining was not demonstrated in normal oral epithelium. In oral epithelial dysplasia, staining was seen in all cases (100%) in the basal layers of the epithelium and in 30% of cases it extended into the parabasal compartments as well. iNOS staining was uniformly positive in moderate dysplasia with an increase in intensity and distribution noted as the severity of dysplasia progressed. There were highly significant differences in overall positivity for iNOS in epithelium between cases and controls (Mann-Whitney U=11.000, Wilcoxon W=221.00, P=0.000). Significant comparisons were made of mild Vs moderate dysplasia (Mann-Whitney U=48.000, P=0.014) CONCLUSIONS: This study supports our earlier morphological assessment (image analysis) of the nature of vascularity in OSF mucosa. The significant vasodilation noticed in these cases argues against the concept of ischemic atrophy of the epithelium. This observation of vascularity and iNOS expression helped to explain the vasodilation noticed (sinusoids) in this disease; NO being a net vasodilator. The mechanism of activation of iNOS in dysplasia is difficult to explain. The role of contingent paracrine-activating factors on keratinocytes and macrophages is discussed.
الموضوعات
Adult , Antibodies, Monoclonal/diagnosis , Atrophy , Disease Progression , Epithelium/enzymology , Female , Gene Expression Regulation, Enzymologic/genetics , Humans , Immunohistochemistry , Male , Mouth Mucosa/enzymology , Nitric Oxide Synthase Type II/genetics , Oral Submucous Fibrosis/enzymology , Up-Regulation/physiology , Vasodilation/physiologyالملخص
Immunohistochemical staining of formalin fixed, paraffin embedded tissue sections of OSF for MMPs-1,2,9 and their tissue inhibitors TIMP-1and 2 was performed using monospecific antibodies coupled with gelatin zymography (MMP-2 and 9) for measuring enzymatic activity quantitatively and for distinguishing the active from the inactive variants of enzymes. The present study, contrary to earlier reports, recorded statistically significant increase in the levels of stromal expression of MMP-1, MMP-2 and MMP-9 and TIMP-1 and TIMP-2 using monospecific antibodies reacting against tissue antigens.The simultaneous increase in reactivity of MMPs and TIMPs poise difficulty in interpretingthe results of this study. The possible reasons for this result, against the backdrop of existing knowledge, were attempted in this study.
الموضوعات
Adult , Antibodies, Monoclonal/diagnosis , Biopsy , Case-Control Studies , Epithelial Cells/enzymology , Female , Humans , Immunohistochemistry , Male , Matrix Metalloproteinase 1/analysis , Matrix Metalloproteinase 2/analysis , Matrix Metalloproteinase 9/analysis , Mouth Mucosa/enzymology , Oral Submucous Fibrosis/enzymology , Prospective Studies , Stromal Cells/enzymology , Tissue Inhibitor of Metalloproteinase-1/analysis , Tissue Inhibitor of Metalloproteinase-2/analysisالملخص
Diagnosis of hepatocellular carcinoma (HCC) is not always easy on simple hematoxylin and eosin (H&E) stain. The diagnostic problems arise when tumor shows pseudoglandular, pleomorphic or clear cell differentiation. Various tumors markers have been described with varying sensitivity and specificity. Monoclonal antibody Hep Par 1 (OCH1E5) which is specific for hepatocytes offers great help in separation of these tumors. The aim of the present study was to determine utility of Hep Par 1 (OCH1E5) in differentiating HCC from metastatic tumors and cholangiocarcinoma. Total of 62 cases of liver tumors obtained from biopsies, resected or autopsy specimens were included in the study. Slides having representative sections were subjected to immunohistochemistry with monoclonal antibody Hep Par 1 (Dako Corp) using avidin biotin technique with primary antibody dilution of 1:40. Adjacent nontumorous hepatocytes were taken as positive control. Slides were examined by experienced pathologist without any information of clinical or H&E diagnosis. Cases were considered positive for Hep Par 1 if tumor cells showed cytoplasmic brown colored granules. The intensity and distribution (diffuse/ focal) of immunoreactivity was noted. Subsequently immunohistochemistry results were correlated with histology and clinical diagnosis. Hep Par 1 antibody was positive in 26 (42 %) and negative in 36 (58 %) liver tumors. On correlating with H&E sections, out of 26 positive cases, 25 (89.2%) were HCC and one was the case of metastasis of mucin secreting adenocarcinoma. From 36 tumors with negative staining 3 were cases of HCC, 27 metastatic adenocarcinomas and 6 cholangiocarcinomas. Only one case of liver metastasis of mucin secreting adenocarcinoma showed positivity. None of the cases of cholangiocarcinoma showed positivity for Hep Par 1. The three HCCs which did not take up staining for Hep Par 1 were 2 cases of moderately differentiated HCC having pseudoglandular pattern and a case of well differentiated HCC with trabecular arrangement. In 11(44%) cases staining was diffuse while in 14 (56%) it was focal but intense. Hep Par 1 is a useful marker in differentiating HCC from metastaic tumors and cholangiocarcinoma with sensitivity and specificity of 89 % and 97 % respectively and positive predictive value of 96 %. However one should be aware of limitations of immunohistochemistry.
الموضوعات
Adult , Antibodies, Monoclonal/diagnosis , Antibodies, Neoplasm/diagnosis , Antigens, Neoplasm/immunology , Antigens, Surface/immunology , Biopsy , Carcinoma, Hepatocellular/immunology , Cell Differentiation/immunology , Diagnosis, Differential , Hepatocytes/immunology , Humans , Immunohistochemistry , Liver/metabolism , Liver Neoplasms/immunology , Neoplasm Metastasis , Sensitivity and Specificity , Biomarkers, Tumor/analysisالملخص
Burkholderia pseudomallei is the causative agent of melioidosis, a severe and potentially fatal infectious disease in humans known to be endemic in Southeast Asia and northern Australia. The infection is also increasingly recognized in various animal species with a potential to spread to humans. With the potential as a biological warfare agent, specific serodiagnosis of melioidosis for surveillance in large populations at risk, humans or animals, would be highly valuable. In this study, a competitive enzyme-linked immunosorbent assay (ELISA) using a lipopolysaccharide-specific monoclonal antibody was developed. The assay provides high specificity, based on a previously described monoclonal antibody to a specific epitope on the lipopolysaccharide (LPS) of B. pseudomallei. The assay sensitivity of 96.0% and specificity of 100% were achieved at a cutoff value of 50% inhibition in human culture-proven melioidosis cases. An optimal cutoff value of 65% inhibition for sera from a melioidosis endemic area was obtained by ROC analysis and resulted in an assay specificity of 86.2%, while maintaining assay sensitivity of 92.0%. A potential application of the assay in the serodiagnosis of melioidosis in animal species was also evaluated usina dolphin sera with satisfactory results.
الموضوعات
Animals , Antibodies, Bacterial/immunology , Antibodies, Monoclonal/diagnosis , Antigen-Antibody Reactions/immunology , Antigens, Bacterial/immunology , Burkholderia pseudomallei/immunology , Endemic Diseases , Enzyme-Linked Immunosorbent Assay , Humans , Lipopolysaccharides/immunology , Melioidosis/diagnosis , Sensitivity and Specificity , Serologic Tests , Thailand/epidemiologyالملخص
Recent progress in understanding the biology of keratins together with the development of monoclonal antibodies to individual keratin proteins provide the foundation for studying the keratin expression in normal and pathological oral epithelia. Cytokeratin (CK) alterations have been reported in carcinomas and these have been associated with specific aspects of tumour behaviour. Immunohisto-chemistry with monospecific CK19 antibody was used to study the expression pattern in normal mucosa, dysplasias, and oral squamous cell carcinomas (OSCC). In non-keratinzed normal mucosa, CK19 was detected in the basal cell layer, while in dysplasias (diagnosed in H and E stained sections, mild-severe) stained strongly for CK 19 in the basal and supra basal cell layers indicating layer specificity for CK 19 expression. In OSCC, in the number of CK19 labelled cells increased from well to poorly differentiated tumour. Thus the results of the present study indicate an alteration in synthesis of keratin proteins when exposed to carcinogens.
الموضوعات
Antibodies, Monoclonal/diagnosis , Carcinoma, Squamous Cell/pathology , Coloring Agents/diagnosis , Epithelium/pathology , Fluorescent Dyes/diagnosis , Humans , Immunoenzyme Techniques , Immunohistochemistry , Keratins/analysis , Leukoplakia, Oral/pathology , Mouth Mucosa/pathology , Mouth Neoplasms/pathologyالملخص
Monoclonal antibodies to human thyroglobulin were produced using the hybridoma technique. Two monoclonal antibodies D5I and F9I were radiolabeled with 125I and used for radioimmunolocalization studies in an immunosuppressed animal model bearing xenografts of human thyroid tumor tissue. Biodistribution studies were carried out at various time intervals post-injection. Maximum tumor uptake was obtained at 72 hr after administration of the antibodies. The absolute tumor uptake (ATU) expressed as percentage of injected dose per gram of tissue (% ID/g) was 15.49 +/- 2.47, 4.51 +/- 0.69 and 2.50 +/- 0.41 for D5I, F9I and control Igs respectively. The tumor to blood ratios (T/B) obtained were 3.01 +/- 0.43 for D5I, 0.98+/-0.2 for F9I and 0.47 +/- 0.12 for control Igs. ATU as well as T/B ratio obtained with D5I was significantly higher as compared to F9I and control Igs. The results indicated the potential application of radiolabeled monoclonal antibodies to human thyroglobulin for tumor targetting in patients of differentiated thyroid carcinoma, particularly those metastases which did not concentrate radioiodine.
الموضوعات
Animals , Antibodies, Monoclonal/diagnosis , Female , Humans , Iodine Radioisotopes/diagnosis , Isotope Labeling , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Transplantation , Radioimmunoassay , Thyroglobulin/immunology , Thyroid Gland/metabolism , Tissue Distribution , Transplantation, Heterologousالملخص
The 3 murine monoclonal antibodies, Yps1, Yps2 and Yps3 reactive to Y. pseudotuberculosis can be stabilized and all were found to be of IgG type. Monoclonal antibody, Yps1, recognized a glycoprotein antigen of the organism with reactivity at the 55-75 kDa region, while Yps2 and Yps3 recognized protein antigens of Y. pseudotuberculosis 65 kDa and 26-28 kDa molecular weight regions, respectively. The specificity of monoclonal antibodies was tested using dot ELISA and Western blotting with whole cell organisms or whole cell sonicated soluble antigens of different Yersinia species, Salmonella typhi, Klebsiella pnemoniae, Streptococcus abortus-equi and Escherichia coli. Monoclonal antibody, Yps1 exhibited cross-reactivity with soluble antigens and whole cell preparations of Y. pestis. Yps2 cross-reacted to soluble antigens of all the tested bacteria. Reactivity of monoclonal antibody, Yps3 was restricted to Y. pseudotuberculosis and Y. pestis with soluble antigen preparations. No reaction was observed with Yps2 and Yps3 to whole cell organism preparations from tested bacteria including Y. pseudotuberculosis. The co-agglutination reagent prepared by sensitizing staphylococcal cells with Yps1 monoclonal antibody produced a positive agglutination with all the 4 Y. pseudotuberculosis isolates and the 3 Y. pestis strains tested. Sandwich dot ELISA using monospecific antisera as a capture antibody and a monoclonal antibody, and Yps3 as a revealing antibody had a high level of specificity in detecting Y. pseudotuberculosis antigens.
الموضوعات
Animals , Antibodies, Monoclonal/diagnosis , Cross Reactions , Enzyme-Linked Immunosorbent Assay , Male , Rabbits , Sensitivity and Specificity , Yersinia pseudotuberculosis/isolation & purification , Yersinia pseudotuberculosis Infections/diagnosisالملخص
BACKGROUND: About 10% of meningiomas behave aggressively and are graded atypical or malignant with important therapeutic and prognostic implications. Routine histological parameters are inconsistent in the assessment of their aggressive behavior. AIMS: The aim of this study was to find a threshold level of the MIB-1 labeling index (MIB-1 LI) with the highest diagnostic validity in predicting histological atypia in a meningioma. SETTING AND DESIGN: This was a retrospective study of all atypical and malignant meningiomas diagnosed at our center between January 1995 and June 2000 and which were identified from the General Pathology Registry. MATERIAL AND METHODS: These meningiomas were assessed histologically with respect to the individual criteria of atypia. They were categorized according to the WHO 2000 classification as benign, atypical and anaplastic meningiomas, WHO Grades I, II and III respectively and by immunohistochemical analysis using the MIB-1 monoclonal antibody. STATISTICAL ANALYSIS: The diagnostically useful cut-off level for the prediction of atypia was estimated by calculating the sensitivity and specificity of the MIB-1 LI at various levels and a receiver operated characteristic (ROC) analysis was performed. The correlation between the individual histological parameters was studied and the MIB-1 LI was obtained using Fisher's exact test. RESULTS: Of the 40 meningiomas studied 21 were benign, 16 atypical and 3 anaplastic. Atypical tumors had a higher MIB-1 LI than benign tumors, with diagnostic validity highest at a threshold of 7%, with a sensitivity of 0.86 and a specificity of 0.93, giving a likelihood ratio of 17. The MIB-1 LI correlated well with mitotic activity and the other individual criteria in the WHO 2000 definition of atypia in a meningioma. MIB-1 LI did not, however, correlate well with brain invasion. CONCLUSION: The MIB-1 LI has the highest validity in the diagnosis of atypia in meningiomas at a threshold level of 7%. The MIB-1 LI used in conjunction with histological features can help in making a recommendation regarding potentially aggressive behavior in meningiomas.
الموضوعات
Adolescent , Adult , Aged , Antibodies, Antinuclear/diagnosis , Antibodies, Monoclonal/diagnosis , Female , Humans , Immunohistochemistry/methods , Ki-67 Antigen/analysis , Male , Meningeal Neoplasms/chemistry , Meningioma/chemistry , Middle Aged , Reproducibility of Results , Retrospective Studiesالملخص
In this study, specific hybridomas secreting monoclonal antibodies (MAb) to antigen of Strongyloides stercoralis filariform larvae were produced. Specific epitopes targeted by the MAb were protein in nature and located in situ in the internal content of the filariform larvae of the parasite but not in the esophagus. The MAb reacted to the homologous antigen in an indirect ELISA but did not reveal any reaction to the SDS-PAGE separated-homologous antigen in a Western blot analysis (WB) suggesting a conformational epitope specificity. The MAb were of IgG1 isotype which is the isotype known to have high affinity to this epitope so they were used in a dot-ELISA to detect the antigen of the parasite. The assay could detect the epitopes in 78 ng or more of the crude filariform larval extract but did not reveal any positive result when applied to detect antigen in stool samples of parasitologically confirmed strongyloidiasis patients. The negative antigen test results can be explained as follows. Either the MAb were filariform stage-specific and thus did not recognize the rhabditiform larval antigen mainly contained in the patient's stool or the amounts of antigen in the stool samples were too small and/or unevenly dispersed. In the latter instance, the MAb developed in this study would have a diagnostic potential if used in an immunological test design where more volume of fresh stool sample could be accommodated in the test, e.g. a sandwich plate ELISA.
الموضوعات
Animals , Antibodies, Helminth/immunology , Antibodies, Monoclonal/diagnosis , Antibody Specificity , Antigens, Helminth/immunology , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay/methods , Epitopes/immunology , Feces/parasitology , Humans , Hybridomas , Larva/immunology , Mice , Sensitivity and Specificity , Strongyloides stercoralis/immunology , Strongyloidiasis/diagnosisالملخص
CD13 is a pan-(MPO-positive) AML antigen, while it is expressed in some B-lineage neoplasms (ALL and PLL) and in T-linaege neoplasms at pro-thymic stage. Some reports have described the lack of this antigen in MPO-positive AML, and tried to regard such MPO-postive AML cases as an clinical entity. However, considering the easy induction or enhancement of the expression in in vitro culture, it is pertinent to interpret that the expression of CD13 in these "CD13-negative and MPO-positive AML" cases is marginally positive, which is readily induced or enhanced in expression in in vitro culture. It can, however, be pointed out that the CD13 expression in ex vivo-positive cases are significantly stronger than that in ex-vivo-negative in vitro-positive cases. Such consideration is necessary particularly in interpreting the results obtained after overnight transportation in commercial laboratories.
الموضوعات
Antibodies, Monoclonal/diagnosis , CD13 Antigens/analysis , Humans , Leukemia, Myeloid/immunology , Tumor Cells, Culturedالملخص
BACKGROUND & OBJECTIVES: Chikungunya (CHIK) virus has caused numerous large outbreaks in India. No active or passive surveillance has been carried out since the last epidemic which occurred in 1971. For active surveillance, it is necessary to have a test, which can detect the virus from a large number of field-collected mosquitoes. METHODS: The present study describes the standardization of monoclonal antibody (MAb) based antigen capture ELISA to detect chikungunya virus antigen from the mosquitoes. CHIK virus antigen from suspension of experimentally infected mosquitoes and their progeny was captured on mouse polyclonal antibody, while biotinylated CHIK Mab was used as a probing antibody. CHIK virus antigen in the head squashes of virus inoculated mosquitoes was detected using indirect immunofluorescence antibody (IFA) test for confirmation of ELISA results. RESULTS: The ELISA test was sensitive enough to detect antigen even if a small fraction of a single infected mosquito homogenate was incorporated in the test. The IFA test failed to detect CHIK antigen in 10 and 25 microliters of suspension whereas with ELISA it was detected in all the samples. Progeny of Aedes aegypti and Ae. albopictus mosquitoes infected with chikungunya virus did not show the possibility of existence of transovarial transmission. INTERPRETATION & CONCLUSION: This test is rapid and simple since it can be completed in two days as compared to the conventional mosquito inoculation and IFA techniques, which require at least 10 days. There is an additional advantage with this test that a large number of samples can be processed, and the remaining homogenate of the mosquitoes can be used for screening other viruses. Experimental data raised using this test showed that transovarial transmission of this virus does not occur in these vector species.
الموضوعات
Aedes/immunology , Animals , Antibodies, Monoclonal/diagnosis , Antigens, Viral/analysis , Chikungunya virus/immunology , Enzyme-Linked Immunosorbent Assay/methods , Female , Miceالملخص
In vivo tumor targetting with radiolabelled monoclonal antibodies is a promising approach for the diagnosis and therapy of tumors. A specific monoclonal antibody (mAb), DLAB was generated to the Dalton's lymphoma associated antigen (DLAA) from Haemophilus paragallinarum-induced spontaneous fusion. In order to study the tumor localisation and biodistribution properties of the monoclonal antibody, scintigraphic studies were performed using the radiolabelled DLAB. 131-labelled DLAB was administered intravenously into Swiss mice bearing Dalton's lymphoma and external scintiscanning was performed at different time intervals. Clear tumor images were obtained which revealed selective and specific uptake of radiolabel and the results were compared with biodistribution data. The radioiodinated monoclonal antibody showed fast tumor uptake which increased significantly to 14.6% injected dose (ID)/g at 12 hr post-injection. Enhanced blood clearance of radioactivity resulted in higher tumor/blood ratio of 5.96 at 48 hr. 131I-labelled DLAB resulted in selective and enhanced uptake of the radioactivity by the tumor compared to the non-specific antibody and the results suggest the potential use of spontaneous fusion for producing specific monoclonal antibodies for tumor detection and therapy.
الموضوعات
Animals , Antibodies, Monoclonal/diagnosis , Antibodies, Neoplasm/diagnosis , Antigens, Neoplasm/immunology , Disease Models, Animal , Iodine Radioisotopes/diagnosis , Lymphoma/immunology , Mice , Mice, Inbred DBA , Radioimmunodetection/methods , Sensitivity and Specificityالملخص
In developing a new method for preparing a radiopharmaceutical for clinical investigation, a thorough understanding of reaction stoichiometry is crucial in optimizing the labelling chemistry. Factors determining labelling efficiency of the 2-mercaptoethanol (2-ME)-mediated 99mTc-labelling of antibody molecules were elucidated using anti-tumor monoclonal antibodies of different IgG subclasses (i.e. IOR-CEA(IgG1), M170(IgG1), 3F8(IgG3) and EMD (IgG2a)) and polyclonal human immunoglobulins (Sandoglobulin). Antibodies which were sensitive to 2-ME reduction (i.e. required 500-1000 molar excess of 2-ME) could tag 99mTc with high efficiency since they possessed abundant reactive sites (i.e. sulfydryl groups) for 99mTc binding. Reduction sensitivity of antibodies was unlikely to be affected by IgG subclass and could be rated as follows: Sandoglobulin > IOR-CEA > 3F8 > M170 > EMD. Concentrations of the reduced antibodies for effective labelling appeared to be related to the reduction sensitivity, i.e. 0.2, 0.4 and 0.6 mg/ml were required for labelling of IOR-CEA, 3F8 and M170 respectively. In addition, susceptibility to 2-ME reduction seemed to reflect the rate of antibody labelling. For 2-ME resistant molecules, i.e. M170 and EMD, successful labelling could be achieved by using a slow 99mTc reducing agent such as SnCl2 instead of SnF2 which reacted more rapidly. Since 2-ME generates reactive sulfhydryl groups that are distal to antigen binding sites, the immunoreactivity of the modified antibody was not affected by the effect of reduction.
الموضوعات
Antibodies, Monoclonal/diagnosis , Humans , Immunoglobulins/diagnosis , Isotope Labeling/methods , Radioimmunodetection/methods , Radiopharmaceuticals/chemistry , Reducing Agents/chemistry , Technetium/chemistry , Tumor Cells, Cultured/drug effectsالملخص
A comparison between R-phycocyanin (R-PC)-labeled monoclonal antibody (MAb) probe and R-phycoerythrin (R-PE)-labeled MAb probe for the detection of the three standard reference strains of the cultured-derived Entamoeba histolytica trophozoites, namely HK-9, HM-1:IMSS, and HTH-56:MUTM were evaluated by using direct immunofluorescence antibody (DIFA) assay five times for each strain. Under the blue irradiation of the fluorescent microscope, both R-PC-labeled and R-PE-labeled MAb probes showed consistently greenish-yellow trophozoites and golden-orange trophozoites, respectively. The R-PE-labeled MAb probe stained the trophozoites more brightly and clearly than those stained by the R-PC-labeled MAb probe of the same Eh208C2-2MAb. When observed under the green irradiation, both probes showed the same intensity of brightly red color at the trophozoites of all three strains of E. histolytica. The sensitivity of both tests was 100%. Since this Eh208C2-2MAb could recognize specifically E. histolytica pyruvate:ferredoxin oxidoreductase (PFOR) enzyme, therefore, our two antibody probes would be valuable for use as a rapid, easy and sensitive test for diagnosis of invasive amebiasis. Further applications of these two probes directly onto the fecal sample spots and to more culture-derived strains of E. histolytica/E. dispar of known zymodemes in collaboration with the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDRB), Dhaka, Bangladesh, are under investigation.
الموضوعات
Animals , Antibodies, Monoclonal/diagnosis , Antibodies, Protozoan/diagnosis , Dysentery, Amebic/diagnosis , Entamoeba histolytica/immunology , Entamoebiasis/diagnosis , Fluorescent Antibody Technique, Direct/methods , Fluorescent Dyes , Humans , Mice , Phycocyanin/diagnosis , Phycoerythrin/diagnosis , Reproducibility of Results , Sensitivity and Specificityالملخص
Group A rotavirus, obtained from children of Goiânia, Brazil, during 1987-1994, were analyzed for subgroup and G serotype by enzyme-linked immunosorbent assay with monoclonal antibodies. The index of serotyping obtained was 61.4% with the following proportions: G1--19.7%, G2--28.0%, G3--9.8%, G4--1.5%, and G5--2.3%. It was observed that G1 occurred from 1987 to 1989 and from 1993 to 1994, and G2 from 1990 to 1993. About 94% of the samples (85/90) could be subgrouped with the following results: 55.5% for SG II, 7.8% SG I, and 31.1% for SG non-I-non-II. Unusual relationship patterns were also detected among serotypes, subgroups, and profiles of electropherotypes in 57.0% of the samples: 20 of them were G2/SG II/"long" profile. The results suggest that variation in temporal and regional characteristics should be considered in the development of rotavirus vaccine.
الموضوعات
Antibodies, Monoclonal/diagnosis , Antibodies, Viral/blood , Brazil/epidemiology , Child , Child, Preschool , Diarrhea/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunization Programs/organization & administration , Infant , Male , Rotavirus/classification , Rotavirus Infections/epidemiology , Serotypingالملخص
Although dengue virus infects a variety of cells in vitro, little is known about cell types infected in vivo. Since blood is a readily accessible tissue, we chose to determine which circulating blood cells are infected by dengue viruses. We collected blood mononuclear cells from acutely ill dengue patients and separated the cells by flow cytometry into subsets for virus isolation. Cells were sorted into groups corresponding to the cluster designations CD3, CD14, CD16 and CD20. Virus was isolated from sorted groups by inoculation into Toxorhynchites splendens mosquitos. The majority of the virus was recovered from the CD20 or B cell positive subset. Little virus was isolated from monocytes, NK cells or T cells. Virus was isolated from B cells regardless of the age or sex of the patient, virus serotype isolated, or the patient's history of dengue virus infection. The location of cell associated virus was determined by proteolytic digestion of surface virus. There was an equal distribution of virus between the intracellular compartment and the surface of B cells. The intracellular localization of virus was confirmed by immunocytochemistry. Since this study focused on circulating cells, no inferences were made regarding infection of cells in solid tissues.