Bentonite Flocculation Test Research Articles

An epidemiologic study of trends in prevalence of rheumatoid factor seropositivity in Pima Indians: evidence of a decline due to both secular and birth-cohort influences.

Previous population studies have suggested that both rheumatoid factor (RF) production and rheumatoid arthritis (RA) may be declining in occurrence, and both secular and birth-cohort influences have been implicated. Since Pima Indians have a very high incidence of RA and also have shown recent evidence of a decline in RA, this study evaluated the relative contributions of age, secular, and birth-cohort influences on RF seropositivity in the Pima Indian population. RF data, as assayed by both the bentonite flocculation test (BFT) and the sheep cell agglutination test (SCAT), were available on 5,345 Pima Indians born between 1886 and 1975, who were surveyed at biennial intervals between 1966 and 1995. An age-period-cohort analysis was conducted using data on 18,295 examinations undertaken during the period of study. There was a decline in the proportion of positive test results for RF (titer > or = 1:32) by both BFT and SCAT, in both male and female subjects from 1966-1975 to the later decades of the study (1976-1985 and 1986-1995). Across all periods, by both assays, the crude proportion of positive titers increased with increasing age of the subjects. There was a very clear birth-cohort effect: the highest likelihood of seropositivity was in those individuals born around the end of the nineteenth century, with continuing decline in seropositivity up to the most recent birth cohort. A logistic regression analysis, adjusting for Pima heritage and sex, demonstrated a substantially greater influence of birth cohort than of calendar year on the frequency of RF positivity. In the Pima Indian population, environmental influences in early life are important predictors of the lifelong likelihood of RF positivity. This may have implications for understanding the epidemiology and etiology of RA.

Immuno-diagnosis of amoebiasis by antibody detection.

Serodiagnosis of amoebiasis can be accomplished by indirect hemagglutination, counterimmunoelectrophoresis indirect fluorescent antibody tests or enzyme-linked immunosorbent assay. The specificity and the sensitivity can be improved considerably by applying axenic antigen. Other tests like amoeba immobilization and complement fixation tests are inadequate. Bentonite flocculation and Latex agglutionation tests have similar drawbacks. Agar gel diffusion or immunoelectrophoresis may be used along with the other tests like indirect hemagglutination test, to differentiate the active disease. The detection of coproantibodies may prove useful especially in asymptomatic cases. Antibodies detection in liver abscess aspirates has limited utility, if any, in cases in which serum antibody titres may not be demonstrated at a significant level. Intradermal test (immediate type of hyper-sensitivity) because of its limitations has not much wide application for the diagnosis in routine.

Quantitative determination of rheumatoid factor by an enzyme-labeled immunoassay

The presence and quantity of rheumatoid factor (RF) in human serum were determined by an indirect enzyme-linked immunoabsorbent assay (ELISA). A human rheumatoid factor control serum, standardized against the WHO reference rheumatoid arthritis serum preparation, was used to derive a standard curve in each assay. The results of unknowns were estimated from the standard curve and reported in International Units (IU) per milliliter (ml). The ELISA assay was compared with the bentonite flocculation test. The overall coefficient of correlation between the two assays was 87%; it was 93.3% for patients with rheumatoid arthritis but only 67.5% for patients with undiagnosed conditions. The error of the ELISA assay (coefficient of variation) was generally less than 10% at both high and low concentrations of rheumatoid factor. The quantitative reproducible nature of the assay allows the detection of small variations of rheumatoid factor level and could be useful in the serial evaluation of patients.

Serological properties of turnip mosaic virus.

The sensitivities of some serological methods such as tube precipitin, ring interface, bentonite flocculation and agar gel immunodiffusion tests were compared by using antiserum prepared with purified turnip mosaic virus (TuMV) and various antigen preparations of the virus. When crude sap from infected plants or partially purified virus preparation was used as an antigen, the tube precipitin, ring interface and bentonite flocculation tests showed almost similar sensitivities. When purified TuMV or its degraded protein was used, however, the sensitivity of bentonite flocculation test was remarkably high as compared to other methods. In agar gel immunodiffusion test, intact virus antigen did not react with antiserum. In order to prepare TuMV antigen useful for immunodiffusion test, the purified virus preparations were subjected to ultrasonication or chemical degradation. When the virus suspensions were sonicated for various periods, both mean length of the particles and infectivities were markedly reduced and the reduction correlated with increase of sonication period. The purified virus suspensions sonicated for periods over 1min formed single precipitin line with TuMV antiserum. With preparation sonicated for 5 to 10min, a sharp precipitin line was produced midway between the antigen and antiserum wells. TuMV proteins degraded by BaCl2, ethanolamine or pyrrolidine produced a continuous single and clear precipitin line in agar gel. BaCl2 treatment produced the highest useful amount of soluble antigen for agar gel immunodiffusion test. The products degraded by sodium dodecyl sulfate formed 2 precipitin lines; the faster-diffusing antigen was identical with those degraded with other reagents. No difference was observed in serological properties between the sonicated fragments and degraded proteins of TuMV.

Hydatid disease screening: Sanpete County, Utah, 1971-1976.

Between 1971 and 1976 approximately 20% (2,265) of the population of Sanpete County, Utah, was screened for hydatid disease (Echinococcus granulosus) by intradermal, indirect hemagglutination, and bentonite flocculation tests. Of 34 persons who had follow-up chest radiographs and radioisotope liver scans, 6 were found to have asymptomatic hepatic cysts. If a participant who had pulmonary cysts and negative screening tests were included, the prevalence of asymptomatic hydatid disease would be 3 per 1,000. During the same period, 82 (148 per 1,000) of 553 dogs successfully purged and examined had E. granulosus infections. Human cyst carriage was associated with dog ownership, particularly of infected dogs or in conjunction with sheep raising as the main livelihood. Combinations of immunodiagnostic tests were more efficacious in identifying cyst carriers than the tests used singly. Limitation of screening to high risk groups (e.g., sheep raisers with dogs) can reduce costs without reducing yield. Optimum management of the cyst carrier awaits further information on the natural history of asymptomatic hydatid disease.

SEROLOGICAL RESPONSES IN EXPERIMENTAL BOVINE TUBERCULOSIS

Five two-year-old heifers were each inoculated intravenously with 0.02 mg M. bovis strain AN5. Clinical, haematological and microbiological observations were made during the course of the experiment and antibody levels were measured before and after infection by means of the indirect immunofluorescent antibody (IFA) and bentonite flocculation tests. All cattle developed M. bovis infection varying in severity from peracute tuberculous pneumonia resulting in death within 33 days to chronic progressive generalised tuberculosis. Only cattle developing peracute or acute forms of tuberculosis showed marked haematological changes characterised by leucopenia with lymphopenia. Bacteraemia was detected in the two cattle with peracute tuberculosis 22 days after infection. Anti-mycobacterial antibody was detected after infection in all cattle but fluctuated markedly during the course of the disease. Of a total of 61 serum samples examined from all cattle after inoculation with M. bovis, only 38 were positive to the IFA test and 30 to the bentonite flocculation test. Only 18 were positive to both tests at any one time. IgM was the predominant type of anti-mycobacterial antibody detected by the IFA test and this was found to cross-react with M. avium in almost every sample.

Radiological cervical arthritis in populations.

The prevalence of cervical rheumatoid arthritis and its relationship to rheumatoid serum factors and erosive arthritis in peripheral joints has been studied in radiographs of the cervical spine and of the hands and feet drawn from 12 population samples. The changes were graded in accordance with the Atlas of Standard Radiographs of Arthritis. Rheumatoid arthritis of the cervical spine (grades 2-4) was observed in 4.1% of males and 4.7% of females aged 15 and over. Prevalence was greatest in those born before 1900, 15% of whom were affected. There was a significant association with the sheep cell agglutination test but not with the bentonite flocculation test, though the latter correlated well with erosive arthritis in the joints of the hands and feet. Arthritis of the cervical spine showed a significant correlation with both seropositive and seronegative erosive arthritis in the peripheral joints. A significantly higher prevalence of cervical arthritis than expected was noted in two population samples, one in Germany and the other in West Africa, though in neither was there a high prevalence of peripheral arthritis. The German population had relatively high antistreptolysin titres. A low prevalence of cervical arthritis was noted in populations in Czechoslovakia and in Arizona. 'Congenital' block vertebra had a prevalence of 0.9% in persons born before 1935, but none was observed in those born since. The figures suggest that environmental influences predisposing to cervical arthritis and block vertebra have changed in the last 40 years.

An epidemic of trichinosis after ingestion of wild pig in Hawaii.

Forty-five percent of young adults who ate roast wild pig at a barbecue in Hawaii experienced an illness compatible with trichinosis. Eosinophilia was present in all of those who were ill and in none who remained well. There were no positive results in skin tests with commercial skin-test antigen. Latex agglutination and counterelectrophoresis were equally good methods for the diagnosis of trichinosis and were more sensitive than the bentonite flocculation test. Levels of IgE in those with illness and eosinophilia were not significantly different from the levels in persons who remained well. It is concluded that skin tests should be abandoned until an improved antigen becomes available, that the relative value of diagnostic serologic methods require continued evaluation, and that levels of IgE may not rise significantly after trichinosis.

Reactivity of bentonite flocculation, indirect haemagglutination and Casoni tests in hydatid disease.

Various immunodiagnostic procedures like indirect haemagglutination, immunofluorescence and scolex precipitation have been used in hydatid disease with variable sensitivity and specificity [1–3]. More recently inert substances like latex and bentonite particles have also been employed for serodiagnosis in Trichinosis amoebiasis and hydatid infection [4–6]. These tests have the advantage that they are quite simple to perform and are not time consuming.

Anti-DNA Investigated the DNA bentonite flocculation technique.

The DNA bentonite flocculation test was used to investigate the presence of antibody to DNA. In most sera a prozone-like phenomenon was found, caused by a non-specific inhibition of serum. Anti-DNA was found with extreme frequency in patients with SLE, chronic liver disease, acute hepatitis, infectious mononucleosis, and blood donors over the age of 60, but was found rarely or not at all in patients with some other disease or blood donors under 60 years of age.

Assessment of the bentonite flocculation test for detecting tuberculosis in cattle.

Australian Veterinary JournalVolume 49, Issue 10 p. 445-450 ASSESSMENT OF THE BENTONITE FLOCCULATION TEST FOR DETECTING TUBERCULOSIS IN CATTLE A. W. D. Lepper B. Vet.Med., M.R.C.V.S., Ph.D., M.A.C.V.Sc., A. W. D. Lepper B. Vet.Med., M.R.C.V.S., Ph.D., M.A.C.V.Sc. CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No 1, Parkville, Victoria, 3052Search for more papers by this authorCatherine W. Pearson B.Sc., Catherine W. Pearson B.Sc. CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No 1, Parkville, Victoria, 3052Search for more papers by this authorP. M. Outteridge B.V.Sc., Ph.D., P. M. Outteridge B.V.Sc., Ph.D. CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No 1, Parkville, Victoria, 3052Search for more papers by this author A. W. D. Lepper B. Vet.Med., M.R.C.V.S., Ph.D., M.A.C.V.Sc., A. W. D. Lepper B. Vet.Med., M.R.C.V.S., Ph.D., M.A.C.V.Sc. CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No 1, Parkville, Victoria, 3052Search for more papers by this authorCatherine W. Pearson B.Sc., Catherine W. Pearson B.Sc. CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No 1, Parkville, Victoria, 3052Search for more papers by this authorP. M. Outteridge B.V.Sc., Ph.D., P. M. Outteridge B.V.Sc., Ph.D. CSIRO Division of Animal Health, Animal Health Research Laboratory, Private Bag No 1, Parkville, Victoria, 3052Search for more papers by this author First published: October 1973 https://doi.org/10.1111/j.1751-0813.1973.tb09288.xCitations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume49, Issue10October 1973Pages 445-450 RelatedInformation

Bear meat trichinosis. Epidemiologic, serologic, and clinical observations from two Alaskan outbreaks.

An outbreak of trichinosis associated with the ingestion of bear meat occurred in Anchorage, Alaska, during July and August 1968. Of the 30 persons who ate the bear meat, three developed clinical trichinosis, and two showed serologic evidence of subclinical infection. The symptoms remitted with administration of thiabendazole. Viable larvae were observed in the meat after 81 days of storage at — 18 °C [0 °F], indicating that heat and not cold inactivation may be necessary to prevent trichinosis from infected arctic bears. Bentonite flocculation, latex agglutination, and charcoal-card flocculation tests of serums from 30 persons in this outbreak and of serums from 15 persons infected with trichinosis 9 years previously showed that the charcoal flocculation test is a sensitive indicator of clinical and subclinical infection.

Trichinosis From Bear Meat

Twenty-three people were involved in an outbreak of trichinosis due to ingestion of bear meat. Of 18 persons who ate uncooked meat, 12 developed fever, myalgia, periorbital edema, and eosinophilia. All had positive skin-tests, and ten had positive bentonite-flocculation-tests (BFTs). Of the 11 asymptomatic patients, including all five who had eaten only cooked meat, six had tests negative to both, and five had positive skin tests or BFTs or both.

Use of the Bentonite Flocculation Test for the Diagnosis of Schistosomiasis: Standardization and Evaluation

Use of the Bentonite Flocculation Test for the Diagnosis of Schistosomiasis: Standardization and Evaluation

Schistosoma mansoni: Immunity in Macaca mulatta

Twenty-nine rhesus monkeys were used to investigate immunity to Schistosoma mansoni. Infection with 1000 cercariae conferred complete protection to reinfection; this was demonstrated by failure of challenge cercariae to develop into egg-producing adults. Sensitization of monkeys with adult worm extracts did not result in any protection against subsequent exposure. Humoral response was assayed by indirect hemagglutination, cercarienhüllenreaktion, and circumoval precipitation, bentonite flocculation, and complement fixation tests. Infection or sensitization stimulated reactivity in all except the circumoval precipitation test. In this test reactivity was only induced by infection. Reinfection stimulated marked anamnestic responses detectable by all tests except the circumoval precipitation. Skin tests and passive cutaneous anaphylaxis reactions revealed reaginic type antibody in infected monkeys. Delayed-type skin reactivity was not observed. Antilymphocytic serum, Cytoxan and total-body irradiation were unable to alter the actively acquired immunity.

Schistosoma mansoni Infection in the Rat. I. Worm Burden and Serological Response in Infected, Reexposed, and Antigen-Sensitized Animals

The immune responses in random-bred Sherman and inbred Lewis and ACI rats exposed to a standard dose of 1,000 cercariae of a Puerto Rican strain of Schistosoma mansoni were evaluated. Worm burdens rose to a maximum by the 4th week of infection, and by the 8th week had declined to very low levels. Some protective immunity was conferred by infection and was demonstrable when challenge exposure occurred as early as 4 weeks after initial exposure. Using a battery of 5 serologic tests and passive cutaneous anaphylaxis, sera were evaluated from time of exposure to 23 weeks after infection. Sherman rats infected with S. mansoni had antibodies demonstrable by the indirect hemagglutination test (IHA) and passive cutaneous anaphylaxis (PCA) test 4 weeks after exposure. However, titers obtained by complement fixation, bentonite flocculation, cercarienhiillen reaktion, or circumoval precipitin tests rose to high levels after the decline in worm burden. Animals sensitized to S. mansoni antigen by use in PCA tests developed IHA antibodies only. Previous studies of Schistosoma mansoni infections in the rat revealed this host to be refractory to massive infection (Koppisch, 1937; Krakower et al., 1940; Cram and Files, 1947; Moore et al., 1949; Stirewalt et al., 1951; Thompson, 1954; Kuntz et al., 1954). Stirewalt et al. (1951), Ritchie et al. (1963a), and Smithers and Terry (1965a, b) reported a decline in worm burden of infected animals between the 4th and 8th weeks after exposure. Warren and Peters (1967) showed that, although the same number of cercariae penetrated the skin of the rat, hamster, mouse, guinea pig, and rabbit, the number of worms that had developed by the 4th week after exposure was the lowest in the rat (26% compared with 37 to 50% for the other animals). By the 8th week the worm burden had fallen to 4% compared with 17 to 64% for other hosts. The mechanism of the reduction of worm burden in the rat has not been adequately studied. The loss of worms resembles the phenomenon described by Stoll (1929) for Haemonchus contortus infection in lambs. The classical self-cure reaction requires the trigger of reinfection and the antigenic stimulation of the molting larvae to initiate the process of worm elimination (Soulsby, 1960). The mechanism of this response in the lamb resembles a hypersensitivity reaction of Received for publication 9 December 1969. the immediate type (Soulsby, 1966). However, not all self-cure phenomena require reinfection to initiate response on the part of the host. In Nippostrongylus brasiliensis infections in rats, worm decline takes place in the absence of reinfection (Mulligan et al., 1965). The mechanism of this response appears to be unrelated to reaginic antibody (Ogilvie and Jones, 1968) but associated with antibodies and alterations of the intestinal wall (Barth et al., 1966). In the present study, baseline data were obtained on the worm burden and serologic response in normal, reexposed rats infected with S. mansoni and antigen-sensitized animals. MATERIALS AND METHODS Random-bred Sherman rats were raised in our laboratory. Inbred Lewis and ACI animals were obtained from Microbiological Associates.* The rats were of either sex and weighed 150 to 200 g. The technique of Smithers and Terry (1965a) was used to expose rats to 1,000 cercariae of a Puerto Rican strain of S. mansoni. Rings placed on the shaved abdominal surfaces of the rats held the cercarial suspension during exposure. At selected intervals from the 2nd week through the 23rd week after exposure, a minimum of 5 rats were bled and autopsied. The number of Sherman rats in this series was 133. Worm burdens in the liver and mesenteric veins were determined by severing the hepatic vein and perfusing with citrate-saline * Use of trade names is for identification only and does not constitute endorsement by the Public Health Service or by the U. S. Department of Health, Education, and Welfare.

Isolation and Characterization of Antibodies from Sera of Humans Infected with Echinococcus granulosus

Antibodies were isolated from sera of patients with hydatidosis using an immunoadsorbent prepared by cross-linkage of sheep hydatid fluid with glutaraldehyde. The antibodies eluted consisted mainly of IgG but IgA and IgM were also detected. In sera from patients with echinococcosis, antibodies directed against antigens present in the hydatid fluid can be detected by serological techniques such as indirect hemagglutination (IHA), latex flocculation, bentonite flocculation, complement fixation, and skin sensitivity tests. For review see Kagan (1968). Kagan et al. (1968) demonstrated serological activity in the IgG fraction of a patient's serum. Castagnari et al. (1968) found an increase in IgG and IgA levels both in patients who had undergone surgery several years before, and in recently diagnosed cases. They found serological activity in IHA to reside in the IgG and IgM fractions, though at a much lower level in the latter. Melli et al. (1966) were able to detect reaginic activity in a fraction containing IgA and free from IgM and IgG. Nevertheless, absorption with rabbit antiIgA did not remove the reaginic activity, suggesting the presence of a further type of immunoglobulin possibly similar to that found by Ishizaka, Ishizaka, and Lee (1966) in the sera of atopic patients (IgE). It is clear from these studies that infection with Echinococcus cysts results in the formation of circulating antibodies belonging to several immunoglobulin classes. This paper describes an attempt to isolate such antibodies by an immunospecific method. MATERIALS AND METHODS Sheep hydatid fluid (SHF) A pool of hydatid fluid from liver cysts in infected sheep was used throughout this study. Merthiolate 1/10,000 was added as a preservative and the fluid was stored at -20 C. It was concentrated either by lyophilization or dialysis against Carbowax 20.000 (Union Carbide, USA). Received for publication 18 September 1969. Sera from patients with hydatid cysts P-1 and P-2 were pools from 8 and 7 patients, respectively, whose IHA titers varied from 1/200 to 1/40,000. All these patients had been receiving "biological treatment" at the Hospital Alvarez, Buenos Aires, Argentina. This treatment consists of a course of immunization against Echinococcus granulosus antigens administered intradermally and/or subcutaneously. The antigen employed is a mixture of germinative membrane and hydatid fluid, in the proportion of 100 g of wet membrane to 4 to 6 liters of hydatid fluid of both ovine and bovine origin. Some patients had been under this treatment for a period of more than 10 years. Pool P-3 was from 5 untreated hydatidosis patients. Pools of normal human serum (NS-1 and NS-2) were acquired from persons clinically and serologically free from hydatid disease. All sera were delipidized prior to use by centrifugation followed by filtration at 4 C.

Experiments on the use of latex, bentonite, and water-insoluble antiserum protein polymers in sensitive serological tests

Experiments were performed to detect low concentrations of plant viruses with the latex-agglutination test, the bentonite-flocculation test, and a test using water-insoluble antiserum protein polymers. Special attention was paid to the potato viruses X and S, and to the influence of high concentrations of normal plant constituents, notably from potato plants, on the sensitivity of the methods. It was found that under certain circumstances lower virus concentrations could be detected with these methods than with the conventional micro-agglutination or micro-precipitation test. However, sensitivity was negatively influenced by sap from potato plants, especially in experiments with potato virus S. To really profit from the sensitive tests mentioned, their sensitivity should be greater than in my experiments.

Adaptation of the Bozicevich Trichinella bentonite flocculation test for the diagnosis of amebiasis.

Standard reagents and procedures employed in the Bozicevich Trichinella bentonite flocculation test (BFT) were used, the bentonite particles being coated with the sonicated antigen of Entamoeba histolytica strain DKB. Serum from 84 of 90 persons (93%) with extraintestinal amebiasis were reactive in the BFT, whereas 43 of 50 serum samples (86%) from persons with symptomatic intestinal disease were positive. None of 24 serum samples from asymptomatic carriers was positive, nor was any of 279 specimens obtained from persons with a variety of gastrointestinal, parasitic, bacterial, or virus diseases. The BFT showed good positive-negative agreement (93%) with the indirect hemagglutination test on tests of 121 selected serum samples. The BFT became nonreactive earlier than did indirect hemagglutination in tests on serum from two of five follow-up cases of amebiasis. The BFT is another useful procedure for the serodiagnosis of amebiasis.

In Vitro Detection of Antibody to Cholera Enterotoxin in Cholera Patients and Laboratory Animals

Two new in vitro microtests for anticholeragen (cholera exo-enterotoxin) antibodies are described and compared. In both tests, choleragen and choleragenoid, antigenically identical purified moieties which differ in size, charge, and toxicity, may be used as sensitizing antigens with apparently equal facility. The passive hemagglutination (PHA) test in which sensitized tanned chicken erythrocytes are used was found to be more sensitive than the sensitized bentonite flocculation test. Tests with sera from cholera patients almost invariably demonstrated a rise in titer on convalescence. Results with the PHA test were directly correlated with results derived from in vivo toxin neutralization assays involving inhibition of skin reactivity and the ileal loop reaction. These observations strengthen the hypothesis that choleragen is involved in the pathogenesis of cholera in man and support the unitarian concept that skin reactivity and choleragenesis are manifestations of the same toxin acting in different tissues. Both of the tests described have been modified and used as inhibition tests in the detection and assay of choleragen antigen.