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Biomedical subjects

A Sebastiani

Publications and source records attributed to A Sebastiani.

At least 55 records · Page 3Linked to original sources
PubMed1989

Histamine release test in the diagnosis of human hydatidosis.

An evaluation of the use of the histamine release test (HRT) in the diagnosis of human hydatidosis is presented. This technique, which makes it possible to evaluate directly IgE dependent immediate hypersensitivity by measuring the histamine released from leucocytes (basophils) after antigenic challenge, was compared with the detection of serum specific IgE by the radio-allergosorbent test (RAST), and with the determination of serum specific IgE by the enzyme-linked immunosorbent assay (ELISA). Of the 54 patients with hydatidosis, all were positive according to HRT, 42 according to RAST and 47 according to ELISA. No false positive results were obtained by HRT in 43 patients with parasitosis other than hydatidosis, however, of these 43, 10 resulted in false positives according to RAST and five according to ELISA. It is concluded that HRT is more sensitive and more specific than RAST and ELISA.

Basophils↗
PubMed1989

Total and specific IgE in sera from patients with invasive amoebiasis.

Total and specific IgE antibodies were determined in 20 patients with invasive amoebiasis. Using a histamine release assay by passive sensitized human leukocytes, a significant increase of Entamoeba histolytica induced IgE-mediated histamine liberation was found in basophils sensitized with sera from patients with amoebiasis as compared to those of control groups. Concerning the total serum IgE, no statistically significant changes were found in different serum groups. Our results suggest that E. histolytica can induce a detectable level of circulating specific IgE without change in total serum IgE.

Amebiasis↗
PubMed1988

A new serological technique, time-resolved fluoroimmunoassay (TRFIA), for the immunological diagnosis of urinary schistosomiasis.

The application of a new serological method, time-resolved fluoroimmunoassay (TRFIA), is described for the diagnosis of urinary schistosomiasis. A chelate of lanthanides (europium) with a long fluorescent life-time is used as label. The intensity of fluorescence is measured after a delay selected to eliminate almost completely the background fluorescence, which decays rapidly. TRFIA was compared with an established method, enzyme linked immunosorbent assay (ELISA). Using sera from proven cases of Schistosoma haematobium infection, 98.1% of the samples were positive by TRFIA and 86.5% by ELISA. Sera from patients infected with helminths other than schistosomes produced only 1.5% of false positives with TRFIA, compared with 12.3% by ELISA. TRFIA is more sensitive and specific than ELISA.

Enzyme-Linked Immunosorbent Assay↗
PubMed1987

Application of time-resolved fluoroimmunoassay (TR-FIA) for the diagnosis of invasive amoebiasis.

A development of solid-phase immunoassay, time-resolved fluoroimmunoassay (TR-FIA), was used for anti-amoebic antibodies. The test used a chelate of the lanthanide europium as label. The long fluorescent life-time and large Stoke's shift of europium chelates permit sensitive detection in a time-resolved fluorimeter. The TR-FIA was compared with counterimmunoelectrophoresis (CIEP), indirect haemagglutination (IHA) and enzyme-linked immunosorbent assay (ELISA) using 61 sera from patients with invasive amoebiasis, 344 sera submitted routinely for amoebic serology without clinical data, 125 sera from patients with diseases other than amoebiasis, and 86 sera from "healthy" individuals. Overall agreement between TR-FIA and ELISA was 97.1%, between TR-FIA and IHA 93.2%, and between TR-FIA and CIEP 94.0%. Sensitivity, specificity and positive and negative predictive values were calculated to compare the 4 diagnostic methods in invasive amoebiasis. TR-FIA showed a higher validity than other methods. The application of such highly detectable labels in immunometric assays promises to open up entirely new areas of research.

Amebiasis↗
PubMed1987

Epidemiological study of parasitic infections in Somali nomads.

In Somali nomads the incidence of intestinal helminths is very low compared with that observed in Somalian closed institutions and practically no Entamoeba infection occurs. Schistosoma haematobium eggs are observed in urine of 50% of adults nomads. Immunological tests reveal that the relative prevalences of leishmaniasis (the lowest), malaria, and toxoplasmosis (the highest) in nomads are similar to those shown by the same techniques in settled communities.

Adolescent↗
PubMed1987

The prevalence and intensity of intestinal parasites in two Somalian communities.

About 85% of the population of two Somali communities harboured soil-transmitted intestinal nematodes and/or protozoa. The commonest parasite (75% in the Lafoole institution and 59% in the Afgoye institution) was Trichuris trichiura. Mixed infections were common. The source of infection is contaminated fields around dwelling quarters, because of indiscriminate defaecation. One of the factors responsible for the higher incidence of hookworm in Lafoole (45%) compared with Afgoye (1.5%) may be the different soil character of the surrounding fields.

Adolescent↗
PubMed1987

Time-resolved immunofluorescence: a sensitive and specific assay for anti-HIV antibody detection in human sera.

We describe a new immunoassay, time-resolved fluoroimmunoassay (TR-FIA), for detection of anti-HIV antibodies in human sera. This method is based on the use of a crude virus preparation coated on a polystyrene microtitre plate and of a swine anti-human IgG labelled with a rare earth metal, europium, as fluorescent label chelated with EDTA derivatives. A light pulse from a xenon lamp (340 nm) was used to excite the label and after a 400 microseconds delay time the emission fluorescence was counted for 400 microseconds at 613 nm. This cycle was repeated 1000 times during the total counting time of 1 s. TR-FIA presents considerable advantages over other techniques: (a) it avoids time-consuming, expensive and hazardous virus purification steps; (b) it excludes the use of radiotracers or substrates with potential health risks to reveal the reaction; (c) it has high sensitivity and specificity. A total of 475 serum specimens were tested by ELISA and by TR-FIA. The proportions of positivity were 29.6% by ELISA versus 26.7% by TR-FIA. The sensitivity of both systems was 100%. The specificity was 87.5% for ELISA, whereas it reached a value of 99.4% for immunofluorimetric assay.

Antibodies, Viral↗
PubMed1987

Clinical anophthalmos in a family.

Monolateral or bilateral anophthalmos recurring in the absence of other associated defects in six members of a family is reported. The malformation appears to be inherited as a dominant (autosomal or X-linked) trait with incomplete penetrance. Implications for genetic counselling are briefly discussed.

Adolescent↗
PubMed1986

Primary hepatitis A virus infection in developing countries: decline of maternal antibodies and time of infection.

In developing countries, HAV seems to be responsible for a widespread, inapparent and protective infection during early childhood. This report emphasizes early infection and its relationship to protection by passive immunity from maternal antibody in a highly endemic area such as Somalia. Our result show that HAV infection in Somalia primarily occurs during the first 4 years of life (4 months to 4 years). Cases are infrequent in the first 3 months due to passive immunity secondary to maternal antibody (cord-blood and colostrum anti-HAV). As the level of protection declines, the rate of acute infection rises as determined by the presence of IgM-specific anti-HAV.

Adolescent↗
PubMed1985

Analysis of HSV isolated from patients with unilateral and bilateral herpetic keratitis.

Restriction enzyme analysis was utilized to investigate 11 HSV isolates from patients with herpetic keratitis. The electrophoretic profiles of the DNAs indicate that the isolates belong to HSV-1 and are epidemiologically unrelated. Two of the isolates, derived from a patient with simultaneous bilateral herpetic keratitis were further characterized by genetic and phenotypic analyses. These studies showed the following: (i) the two recrudescent lesions were caused by the same HSV-1 isolate; (ii) the isolate yielded two different plaque phenotypes; (iii) these plaques showed different sensitivity to I.D.U.

Acyclovir↗
PubMed1985

Hepatitis B virus circulation in three different villages of Somalia.

Hepatitis B virus (HBV) circulation was surveyed in three Somalian villages (Buur-Fuul, Mooda-Moode and Bajuni Islands) in different districts and 52 children living in a closed community, aged under one year, were studied. Of the 331 village subjects aged one to 83 years, 12.08% were HBs positive, 29.9% anti-HBs positive, 43.8% anti-HBc positive and 21.4 anti-HBe positive. Among the HBs-positive subjects, 34.7% had HBeAg and 21.7% had anti-HBcAg-IgM. No statistically significant differences were found for HBs, anti-HBs, anti-HBc and anti-HBe among the three villages. HBeAg prevalence was higher in Buur-Fuul than in Mooda-Moode and in Bajuni Islands. HBsAg prevalence was about the same for each age group studied, whereas the prevalence of anti-HBc showed a continuous rise and reached its maximum level of 43.8% in those aged 39 years and older. The proportion of HBs-positive subjects who also carried HBeAg was high in the youngest children but fell with age. HBs-positive children aged under one year had a high anti-HBc-IgM prevalence. Our finding suggests that perinatal infection may play an important role among the Somalian population in determining the reservoir of virus carriers.

Adolescent↗