Biomedical subjects
Publications and source records attributed to F Papa.
A simple, rapid and reliable thin-layer chromatography method for the detection of the 2,3,6,6'-tetraacyl trehalose-2'-sulphate (sulpholipid I) from Mycobacterium tuberculosis was described. The method was found to be satisfactory as an aid in the rapid identification of M. tuberculosis in clinical laboratories.
Knowledge of mycobacterial glycolipid antigens and the study of their specificity have resulted in their utilization as species markers. We describe a thin-layer chromatography method which could serve as a useful adjunct for the identification of Mycobacterium tuberculosis, M. bovis BCG, M. kansasii, M. gastri and M. marinum.
Immunoglobulin G (IgG) and IgM antibodies against the SL-IV antigen of Mycobacterium tuberculosis in the sera of patients with tuberculosis with negative serology for human immunodeficiency virus (HIV) infection (TB group; n = 97), patients with tuberculosis with positive serology for HIV infection (TB-HIV group; n = 59), and healthy controls (n = 289) were determined by enzyme-linked immunosorbent assay. All sera were obtained at the onset of tuberculosis, i.e., when clinical symptoms appeared. Clinical specimens were collected and cultured for the isolation of M. tuberculosis, and treatment with antituberculous drugs was started. Sera were also obtained from patients in the TB group at fixed intervals during treatment; sera were available from 13 patients in the TB-HIV group before the onset of tuberculosis. The best specificity and positive predictive values were obtained with the IgG assays. In the IgG assays at specificities above 96.0%, the sensitivities of the tests were 45.3 and 72.8% for the TB and TB-HIV groups, respectively, and the sensitivity was 51.9% when data from both groups were combined for analysis. For the TB group, results of this study indicated that the levels of IgG antibodies remain high during treatment. Thus, repetitive serological assays may not be useful for treatment follow-up. In the TB-HIV group, 12 of 13 patients had IgG-specific antibodies against the SL-IV antigen between 1 and 30 months before the onset of tuberculosis, so we suggest that the IgG antibody assay against SL-IV may be helpful for identifying tuberculosis in patients infected with HIV.
Two glycolipids--one synthetic and non-natural (BDA.TDA), the other natural and Mycobacterium tuberculosis species-specific (SL-IV)--were tested to determine their serological activity in sera obtained from leprosy patients, and to determine their discriminating ability in the detection of disease. The ELISA results obtained in the IgG antibody class show that both were useful substances capable of detecting multibacillary and paucibacillary disease in about 2 out of 3 leprosy patients. When these antigens were tested in parallel, the sensitivity of the ELISA test was increased by 10% without a decrease in specificity.
Analysis of cell-mediated immunity [(CMI) as judged from the Mantoux, Fernandez, and Mitsuda reactions and the presence of granulomas in biopsy material] against humoral immunity (measurements of anti-PGL-I, PGL-Tb1, and SL-IV IgG and IgM antibody titers by ELISA) were performed in selected human populations. The investigations yielded data indicating that humoral (B-cell) responses preceded protective CMI in both tuberculosis and leprosy. The B-cell responses were unrelated to (unfavorable) cell-mediated delayed-type hypersensitivity (DTH). Notwithstanding the difficulty in inferring sequential events from studies in humans, it was shown that in humoral responses there was an initial rise of specific IgM immunoglobulins that switched afterward to IgG production during subclinical tuberculosis and leprosy infections. In patent tuberculosis disease the IgM-to-IgG switch was observed in the majority of patients; in patent leprosy disease the switch was impaired in the majority of patients. The clinical, immunological, and laboratory data indicated that the B-cell responses were suppressed as protective CMI was re-established in the patients during the protracted subclinical infection. According to the data, the diagnosis of subclinical tuberculosis and leprosy may be accomplished using ELISA. The yearly risk of tuberculosis in apparently healthy persons but with significant antibody titers was estimated at 44%; the yearly risk for leprosy has not yet been established. The clinical, epidemiologic, and diagnostic implications of these findings are discussed.
The distribution of IgG and IgM antibodies immunoreacting with the sulpholipid I (SLI) and sulpholipid IV (SLIV) of Mycobacterium tuberculosis was examined in sera from leprosy patients. It was found that the immunological reactions correlated with the clinical spectrum of leprosy; and in multibacillary patients, antibody titres declined in response to successful treatment. The serological patterns were similar to the PGL I patterns, however, the IgG responses towards the sulpholipids were predominant over the IgM responses in the case of the sulpholipid antigens.
The authors analysed 1061 early amniocentesis carried out during 1000 pregnancies. The indications were as follows: chromosomal abnormalities (79,6 p. 100), fetal karyotypes for X-linked diseases (4,7 p. 100), metabolic disorders (5,9 p. 100), amniotic fluid alpha-foetoprotein (9,8 p. 100) in neural tube defect or congenital nephrosis. Amniotic fluid was obtained on the first attempt in 98.2 p. 100 and on the second attempt in 100 p. 100. The fluid was heavily blood-stained in 1,7 p. 100, sanguinolent in 3,8 p. 100 and brownish in 2,40 p. 100. Cells were grown on the first attempt in 98 p. 100 and on the second attempt in 100 p. 100. The outcome of pregnancies was correlated with the indications of amniocentesis. The rate of spontaneous abortion is 1,7 p. 100, but only 6 of them can be due to amniocentesis (0,6 p. 100). Perinatal mortality was 1,8 p. 100: mortinatality (1,2 p. 100) and neonatal mortality (0.6 p. 100). All this fetal deaths have other causes. The fetal loss was 3,9 p. 100. Fetal morbidity was low: none fetal injuries, none cutaneous scar, few premature deliveries (1,6 p. 100), some malformations more or less serious (2,6 p. 100) with 4 congenital luxations of the hips (0,45 p 100). Maternal morbidity was limited at a greater cesarean section rate: 21 p. 100 (30 p. 100 in women 40 years old and more), none feto-maternal rhesus immunization was observed because immunoprophylaxis was strictly performed. The rate of therapeutic abortion was 4,6 p. 100 without any diagnostic error. Diagnostic accuracy was 100 p. 100. Several conditions are necessary to be the procedure safe accurate and reliable: appropriate genetic counseling, exact determination of gestational age (17 international weeks), sufficient volume of amniotic fluid counseling, exact determination of gestational age (17 international weeks), sufficient volume of amniotic fluid (uterus size: 12 cm), gynecologic examination by operator himself, perfect echography to localize the placenta and detect multiple gestations, adequately trained obstetrician, use of 20 gauge spinal needle, stric asepsis, experimented laboratory and experienced staff.
Since 1972, we have performed 951 early amniocentesis in 902 pregnant women. There were 19 twin pregnancies, all diamniotic, representing 2.1% of the sample. Diagnosis was always suspected before the amniocentesis. It was confirmed by echography in the 14 cases in which this technique was used. Out of the first 5 cases without echography, we punctured only one sac. In the 14 last cases, the process was successful in 13 cases thanks:--the perfection of echography showing the exact location of the fetuses and the position of the septum--the injection of congo red (12 cases) or methylene blue (2 cases) into the first sac. The indications were as follows: chromosomal aberrations (14 cases) metabolic diseases (1 case), sex-linked disorders (1 cases) neural tube defects (3 cases). No complications due to amniocentesis were observed but three abortions and one fetal death occurred. The reason why is discussed. We have made only one therapeutic abortion.
Anatomical study of a complete form of papyraceous right ventricle in a young adult hospitalized at the terminal. This is the fifth case with an autopsy examination, but the peculiar fact lies in the combination with a spondylo-epiphyseal dysplasia.
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A DOT-ELISA method for detection of 2,3-diacyl-trehalose (DAT, previously referred to as SL-IV antigen) and triglycosyl phenol phthiocerol di-mycocerosate (PGL-Tb1) antigens from Mycobacterium tuberculosis is described. The method enabled the detection of both antigens in 14 clinical isolates of M. tuberculosis from different geographic origins; the presence of the glycolipids was confirmed by chemical analysis. It was therefore concluded that the synthesis of both of these compounds is characteristic of the species.
In La Martinique a study of 7,861 coprocultures shows that the number of Salmonella carriers constantly increases; in 1974, it reaches 3-95 0/0. The main serotypes are: S. panama, S. saint-paul, S. typhi murium and S. anatum. Imported foodstuffs seem to be responsible for this dissemination.
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