PubMed Health⌕ Search

Biomedical subjects

I G Kagan

Publications and source records attributed to I G Kagan.

At least 19 recordsLinked to original sources
PubMed1984

Enzyme-linked immunosorbent assay for the diagnosis of cerebral cysticercosis.

Central nervous system cysticercosis is common in countries where Taenia solium occurs in pigs and the level of hygiene and sanitation is low. The clinical presentation may include epileptic seizures, focal neurological deficits, hydrocephalus, or aseptic meningitis. The disease is frequently seen in California residents of Hispanic origin. It sometimes occurs in whites from homes that employ Hispanic cooks. Diagnosis is often difficult. Computerized tomography scan and brain biopsy are the most reliable diagnostic procedures, but each has its limitations. We have found that a radioimmunoassay improves our diagnostic capability, and more recently we have adapted this to an enzyme-linked immunosorbent assay that is equally sensitive and specific and, in addition, obviates the need for radioactive materials. Details of the enzyme-linked immunosorbent assay procedure and its application to the diagnosis of central nervous system cysticercosis form the basis of this report.

Animals↗
PubMed1981

Gross and histological studies of immediate, Arthus, and delayed skin test responses to schistosome antigen, and of delayed response to ubiquitous antigens in Egyptians.

Gross studies of skin reactions to adult antigen of Schistosoma mansoni were made on 156 hospitalized patients with schistosomiasis and 114 subjects from the nonendemic area of Hurghada in Egypt. Wheal areas equal to or greater than 1.0 cm2 indicated a positive immediate (15-min) reaction to adult worm antigen; the criterion of positivity for both 24-hour and 48-hour delayed reactions was an area of induration equal to or greater than 0.6 cm2. Immediate reactions with adult worm antigen were observed in 99% of the patients with schistosomiasis and 11% of the subjects from Hurghada: the percentages with delayed reaction were 58% and 2%, respectively. Biopsies of skin test sites at various intervals after antigen injection were done on 87 individuals. Eosinophilic and mononuclear infiltrates were characteristic of immediate and delayed skin responses, respectively. Biopsies from 22 patients with marked skin reactions 5 hours after antigen injection showed that a neutrophilic response indicative of Arthus reactivity was present in only 18. Thus, Arthus reactivity could not be determined on gross appearance alone. The studies did not show any evidence of delayed basophilic hypersensitivity to schistosome antigen. Immunofluorescent studies on a small number of biopsies suggested that a late phase (5-hour) reaction due to IgE may occur in some patients. Delayed reactivity to mumps and/or monilia skin test antigens was observed in 91% of Egyptians in a nonendemic area of schistosomiasis. Delayed hypersensitivity to PPD was detected in 44% of the same group.

Adolescent↗
PubMed1981

Acquired immunity in B cell-deficient mice to challenge exposure following primary infection with Schistosoma mansoni.

Mice were made B cell-deficient by injections of globulin prepared from goat antimouse mu-chain serum. Anti-mu globulin was administered throughout the experiments (18 or 23 weeks). B cell deficiency was determined at the time of assay of worm burden levels (7 weeks after challenge with Schistosoma mansoni) by quantitation of serum IgM and IgG, by assaying the specific antibody response to cercarial and adult worm antigens in enzyme-linked immunosorbent assay and by histologic examination of the spleen and mesenteric (regional) lymph nodes. Four-week-old mice were exposed to S. mansoni and 8 weeks later were challenged with a second exposure. The B cell-deficient mice developed a degree of resistance (79%) similar to that of the intact controls (81%). The IgM and IgG levels of the B cell-deficient mice were markedly suppressed. Follicular development was not detected in their lymph nodes; but in the spleen of some animals clusters of cells morphologically similar to B cells were observed peripheral to a central T cell-like area. B cell-deficient mice developed schistosome egg granulomas comparable to those of the intact controls. Control animals developed an antibody response with titers of 1:64 to 1:1,024 against cercarial and adult worm antigens; B cell-deficient animals were nonreactive in these assays. The data suggest that specific antibody does not play a major role in resistance acquired within 8 weeks as a result of a primary infection in murine schistosomiasis.

Animals↗
PubMed1980

Epidemiologic studies among Amerindian populations of Amazonia. III. Intestinal parasitoses in newly contacted and acculturating villages.

The prevalences of intestinal parasites among the residents of three South American Indian villages in the process of acculturation were compared with those found in earlier unpublished surveys in two newly contracted village.s Although one individual in an acculturating village harbored 11 different intestinal parasites, in general the average number of different parasitic species carried per person was somewhat higher in the newly contacted villages. Helminth egg counts, performed on direct smears of each specimen from one newly contacted village, were low. There were no sex-associated differences in prevalences. The overall prevalences, unadjusted for age, were among the highest recorded for Amerindians. No Taenia species were present. Balantidium coli was present in two acculturating villages, concomitant with the beginning of agricultural practices which include raising swine. No cases of moderate or severe protein-calorie malnutrition was observed in any of the villages during the surveys. These limited data provide a baseline for future comparisons and, perhaps, a glimpse into the past.

Acculturation↗
PubMed1979

Immunization against Schistosoma mansoni in rhesus monkeys and the requirement of activation of both cell-mediated and humoral mechanisms.

When groups of rhesus monkeys were pretreated with BCG plus hyperimmune serum from monkeys with chronic schistosomiasis or with dialyzable transfer factor from uninfected monkeys plus hyperimmune serum and were challenged with 1,500 cercariae of Schistosoma mansoni, the mean worm burdens were significantly lower than that of untreated controls. Pretreatment with neither BCG alone nor Corynebacterium parvum plus a membrane antigen of adult worms of S. mansoni affected susceptibility. Neither lymphocyte proliferation in the presence of mitogens or schistosome antigen nor serological responsiveness (as measured by gel diffusion, Cercarienhüllenreaktion, circumoval precipitation, or enzyme-linked immunoabsorbent assay) correlated with the degree of resistance of the animals to S. mansoni. The pretreatment procedures used did not cause any abnormal histopathological responses and did not alter the characteristic host response to schistosome eggs in the lungs, liver, mesenteric lymph nodes, and colon.

Animals↗
PubMed1979

Immune responses to Schistosoma mansoni in rhesus monkeys with multiple chronic and early primary infections.

Immunological reactivity in 10 rhesus monkeys was monitored over a 22-week period. Cellular and humoral responses of three animals were studied after primary infection with Schistosoma mansoni. Two uninfected animals served as controls. Increased lymphocyte proliferative responsiveness to mitogens and adult worm antigen was evident during the prepatent period of the infection. Marked suppression of these responses occurred during the acute phase of the disease, but by weeks 9 and 11 the animals were again responsive to mitogens and antigen, respectively, and remained so throughout the remainder of the observation period. No antibody response to various cercarial, adult worm, and egg antigens could be detected until weeks 5 to 7, after which these responses also persisted. Comparison of the immunological reactivities of these animals with primary infection and those of five chronically infected immune animals indicated possible correlations between protective immunity and (i) strong Cercarienhüllenreaktion reactivity, and (ii) lymphocyte proliferative responsiveness to adult worm antigen.

Animals↗
PubMed1979

The serologic response of hamsters to experimental liver inoculations with Entamoeba histolytica as measured by indirect hemagglutination test and enzyme linked immunosorbent assay.

Results of testing 298 sera from hamsters inoculated in the liver with Entamoeba histolytica and from 25 uninoculated controls by indirect hemagglutination (IHA) and enzyme linked immunosorbent assay (ELISA) showed that measurable amounts of antibody appeared as early as 5 days after inoculation, generally increased to a high level within 20 days, and persisted for the duration of the experiments (58 days). There was fair correlation between size of liver lesion and titers. Strain differences in amebae used for antigen and for inoculation could not be detected by either test. The IHA test appeared to be very sensitive, and titers of 1:16 and above were specific. With the ELISA technique, it was tentatively concluded that titers of 1:32 were specific for anti-amebic antibodies but only those of 1:128 and above were indicative of liver infections in the experimentally infected hamsters.

Amebiasis↗