Production and assay of antibodies against one antigenic component of Mycobacterium bovis BCG.
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Monospecific antisera against BCG antigen 60 were produced by all of four rabbits during immunization with precipitates containing antigen 60 cut out of gels after crossed immunoelectrophoresis. During electrolytic iodination of a crude antigen 60 preparation, preferential labeling of antigen 60 was demonstrated, and a specific radioimmunoassay was established to follow the development of anti-BCG-60 activity during immunization. (+info)
Pneumocystis carinii antigenemia in acquired immunodeficiency syndrome.
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The present study was conducted to determine the prevalence and significance of Pneumocystis carinii antigenemia in patients with acquired immunodeficiency syndrome (AIDS) and clinically or invasively diagnosed P. carinii pneumonitis. Single serum specimens from 20 AIDS patients invasively examined for P. carinii organisms and 106 AIDS patients with a clinical diagnosis only of P. carinii pneumonitis were blindly tested for P. carinii antigenemia by a counterimmunoelectrophoresis assay. In the 20 specimen-documented cases, the antigen test demonstrated a sensitivity of 75% and a specificity of 90%. The positive predictive value of the test was 90%, while the negative predictive value was 70%. In AIDS patients with specimen-documented P. carinii pneumonitis, the prevalence of P. carinii antigenemia coincided almost exactly with the prevalence of positive invasively obtained specimens (60 and 59%, respectively). In patients with a clinical diagnosis only of P. carinii pneumonitis, half as many (30%) were found to exhibit antigenemia. Sequential P. carinii antigen titers determined by a new latex agglutination technique on three AIDS patients with specimen-documented P. carinii pneumonitis demonstrated the influence of specific therapy upon P. carinii antigenemia and its potential prognostic application. (+info)
Deletion analysis of the proteinase gene of Streptococcus cremoris Wg2.
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The Streptococcus cremoris Wg2 proteinase gene, cloned in S. lactis, specified a proteinase which exhibited the same specificity toward casein as did the proteinase isolated from the original host. Although the cloned gene lacked the last 130 codons, the proteinase still specifically degraded beta-casein. Deletion of the C-terminal 343 amino acids from the proteinase did not influence this specificity. Cell-free transcription-translation studies of plasmids carrying deletion derivatives of the proteinase gene showed that the 100-kilodalton C-terminally truncated proteinase still exhibited proteolytic activity. Crossed immunoelectrophoresis revealed that proteins A and B identified in the proteolytic system of S. cremoris Wg2 are both encoded by the proteinase gene. A working model based on integration of available genetic, immunological, and biochemical data is presented to explain this result. (+info)
Precipitating antibodies in mycoplasma infection.
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The effectiveness of counterimmunoelectrophoresis (CIEP) for detecting human precipitating antibodies to mcyoplasma antigen was compared with the conventional complement fixation (CF) method in a double-blind experiment. Fifty-one sera from patients suspected of having acute mycoplasma infection were tested by both techniques. Dense precipitin lines to mycoplasma antigen developed in 28 sera with CIEP. Twenty-six of 28 had elevated CF titers to this antigen. No precipitin bands were observed in sera with low antibody titers to mycoplasma. These findings indicate that the CIEP test is a specific method for reliably detecting elevated serum CF antibody levels in patients with acute or recent mycoplasma infection. (+info)
Identification and partial characterization of a novel bipartite protein antigen associated with the outer membrane of Escherichia coli.
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A study by crossed immunoelectrophoresis performed in conjunction with precipitate excision and polypeptide analysis identified a new antigen complex in the envelope of Escherichia coli ML308-225. This antigen corresponds to antigen 43 in the crossed immunoelectrophoresis profile of membrane vesicles (P. Owen and H. R. Kaback, Proc. Natl. Acad. Sci. USA 75:3148-3152, 1978). Immunoprecipitation experiments conducted with specific antiserum revealed that the complex was expressed on the cell surface and that it contained, in equal stoichiometry, two chemically distinct polypeptides termed alpha and beta (Mrs of 60,000 and 53,000, respectively). The beta polypeptide was heat modifiable, displaying an apparent Mr of 37,000 when solubilized at temperatures below 70 degrees C. Analysis of fractions obtained following cell disruption, isopycnic centrifugation, and detergent extraction indicated that both alpha and beta polypeptides were components of the outer membrane. The two polypeptides were not linked by disulfide bonds, and neither was peptidoglycan associated. The complex contained no detectable lipopolysaccharide, enzyme activity, fatty acyl groups, or other cofactors. Neither correlated with E. coli proteins of similar molecular weight which had previously been shown to be associated with the outer membrane. Antibodies were raised to individual alpha and beta polypeptides. Each of these sera was shown to be subunit specific when tested against denatured membrane proteins. In contrast, each immunoglobulin preparation coprecipitated both alpha and beta polypeptides when tested against undenatured proteins derived from Triton X-100-treated membranes. The results reveal the presence of a novel bipartite protein antigen in the outer membrane of E. coli. (+info)
Precipitating antibodies to rabbit thymus extractable antigens in chronic liver disease: relationship with anti-actin antibodies.
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Using counterimmunoelectrophoresis (CIE), serum antibodies to rabbit thymus extractable antigens were detected in 15% (38/259) of patients with chronic liver disease (CLD) of various aetiologies and 33% (41/124) of patients with miscellaneous connective tissue diseases (CTD). A remarkable diversity of precipitating systems was apparent among cases with the two classes of disorders. All the five systems found in CLD (XR, XR2, SS-B, XR3, XR4) were associated mostly with immunological hepatic disorders. In the 52 autoimmune hepatitis cases, XR was mainly detected (29%), whereas in the 82 primary biliary cirrhosis patients the whole spectrum of reactivities was represented (XR: 11%, XR2: 10%, SS-B and XR3: 2% each, XR4: 1%). XR proved to be closely associated with smooth muscle antibodies (SMA, detected by indirect immunofluorescence on rat kidney sections) both qualitatively and quantitatively. Since all SMA positive sera with anti-actin specificity (SMAT, SMAG) were XR positive and purified actin could absorb out XR CIE reactivity, the hypothesis is made that a cross-reaction occurs between XR antigen and actin epitope(s). (+info)
Comparison between autoantibodies in malaria and leprosy with lupus.
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Sera from 16 patients with falciparum malaria, 16 patients with vivax malaria and 31 patients with leprosy were tested for autoantibodies to intracellular proteins and nucleic acids. Precipitating antibodies to soluble protein extracts were not detected in any serum. Sera from malaria patients showed prominent immunofluorescence staining of the HEP2 nuclear membrane as well as frequent 75% (24/32) and intense Western blot reactivity. In contrast, only 20% and 36% of patients with leprosy had positive immunofluorescence or positive immunoblots respectively, and reactivity was weak in most cases. Neither the malaria nor leprosy sera contained autoantibodies with specificities similar to the characteristic lupus autoantibodies such as double stranded DNA (dsDNA), Ro/SSA, La/SSB, Sm, RNP and P proteins. Low levels of antibodies to single stranded (ssDNA) were however found in 11 (34%) malaria sera and in seven (23%) leprosy sera. Thirteen percent of patients with leprosy had anti-histone antibodies. These findings demonstrate considerable differences in the capacity of infectious agents to induce autoantibodies and also the infrequency with which autoantibodies characteristic of idiopathic systemic lupus erythematosus are induced. (+info)
Diagnosis of acute bacterial pneumonia in Nigerian children. Value of needle aspiration of lung of countercurrent immunoelectrophoresis.
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Eighty-eight Nigerian children with untreated, severe, acute pneumonia were investigated by standard bacteriological techniques (blood culture and culture of pharyngeal secretions) and by needle aspiration of the consolidated lung. Countercurrent immunoelectrophoresis (CIE) against grouped pneumococcal and Haemophilus influenzae type b antisera was carried out on serum samples from 45 patients. The aetiology of pneumonia was shown by examination of the needle aspirate in 70/88 patients (79%), by CIE in 9/45 patients (20%), and by blood culture in 4/36 patients (11%). Overall, a bacterial cause for pneumonia was shown in 73/88 patients (83%). The results of pharyngeal culture were misleading when compared with cultures of needle aspirates. The prediction of aetiology from the radiological appearance was alos inaccurate, even for labor pneumonia. Needle aspiration of the lung, with a low (5%) and minor complication rate, merits wider application in the diagnosis of acute pulmonary infections in children. Tradiational bacteriological techniques (blood culture and pharyngeal culture) are of very limited value. The place of CIE in the investigation of childhood pneumonia still needs thorough evaluation. (+info)