RESUMO

Cultured astrocytes derived from newborn rat brain were inoculated with Junin virus (JV) to characterize their response to infection by means of their glial fibrillary acidic protein (GFAP) immunochemical profile. Samples from 1 to 11 days post-inoculation (pi), as well as matched controls, were serially harvested for GFAP labeling by peroxidase-antiperoxidase (PAP) method. It was only at day 3 that significantly greater values of GFAP staining (P < 0.05) were disclosed by three complementary approaches: image analysis, ELISA and immunoblot densitometry. Since such increase was abolished by Triton X-100 treatment, soluble GFAP fraction appeared responsible for the early though transient enhancement of GFAP immunoreactivity that followed viral inoculation.

Assuntos

RESUMO

Se realizó un estudio prospectivo en 90 neonatos provenientes de madres con rotura prematura de membrana (RPM) mayor de 24h, con el objeto de establecer la incidencia de sepsis neonatal precoz (SNP), determinar su etiología y evaluar la capacidad diagnóstica de pruebas alternativas al hemocultivo; cultivo de hisopado de conducto auditivo externo, de aspirado nasofarígeo y de aspirado gástrico. En los neonatos nacidos vivos, se rigistró una incidencia del 4 por ciento (n=90) de RPM mayor de 24 h, y 6,9//(16/2293 recién nacidos vivos) padecieron SNP. La incidencia de SNP en neonatos de madres con RPM mayor de 24 h fue del 17,8 por ciento (16/90) y se distribuyó de la siguiente forma: 3,3 por ciento (3/90) asociado exclusivamente a RPM sin otro factor agravante, 5,6 por ciento (5/90) cuando se asoció la RPM a corioamnionitis y 8,9 por ciento (8/90) con prematurez. Con respecto a los agentes etiológicos de SNP, predominaron los Gram positivos y, dentro de ellos, Staphylococcus aureus. Ninguna de las pruebas evaluadas alcanzó la seguridad diagnóstica (sensibilidad más especificidad) necesaria para ser utilizada como pruebas alternativas al hemocultivo para diagnóstico de SNP por RPM mayor de 24 h. No obstante, ellas pueden ser empleadas como pruebas complementarias para contribuir a la identificación de recién nacidos de alto riesgo que hayan estado expuestos a infección del líquido amniótico o corioamnionitis

Assuntos

RESUMO

Se realizó un estudio prospectivo en 90 neonatos provenientes de madres con rotura prematura de membrana (RPM) mayor de 24h, con el objeto de establecer la incidencia de sepsis neonatal precoz (SNP), determinar su etiología y evaluar la capacidad diagnóstica de pruebas alternativas al hemocultivo; cultivo de hisopado de conducto auditivo externo, de aspirado nasofarígeo y de aspirado gástrico. En los neonatos nacidos vivos, se rigistró una incidencia del 4 por ciento (n=90) de RPM mayor de 24 h, y 6,9//(16/2293 recién nacidos vivos) padecieron SNP. La incidencia de SNP en neonatos de madres con RPM mayor de 24 h fue del 17,8 por ciento (16/90) y se distribuyó de la siguiente forma: 3,3 por ciento (3/90) asociado exclusivamente a RPM sin otro factor agravante, 5,6 por ciento (5/90) cuando se asoció la RPM a corioamnionitis y 8,9 por ciento (8/90) con prematurez. Con respecto a los agentes etiológicos de SNP, predominaron los Gram positivos y, dentro de ellos, Staphylococcus aureus. Ninguna de las pruebas evaluadas alcanzó la seguridad diagnóstica (sensibilidad más especificidad) necesaria para ser utilizada como pruebas alternativas al hemocultivo para diagnóstico de SNP por RPM mayor de 24 h. No obstante, ellas pueden ser empleadas como pruebas complementarias para contribuir a la identificación de recién nacidos de alto riesgo que hayan estado expuestos a infección del líquido amniótico o corioamnionitis (AU)

Assuntos

RESUMO

In order to evaluate the diagnostic usefulness of coadjuvant tests such as external auditory canal swab culture and cultures from nasopharyngeal and gastric aspirates, and to determine the incidence and etiology of early neonatal sepsis (ENS) at our Unit, 90 newborn cases whose mothers experienced premature rupture of the membranes (PRM) were studied prospectively. Although a firm diagnosis requires positive blood cultures, the difficulty in recovering microorganisms and the trauma induced by sample collection in the baby justify the search for alternative diagnostic tests. Out of 2293 childbirths during 1991, 90 mothers (4%) had PRM more than 24 hours pre-partum, while 6.9/1000 (16/2293) developed ENS. In newborns from PMR mothers, ENS percentage was 3.3%, but increased to 5.5% in association with chorionamnionitis and reached 8.8% in premature cases. Among etiological ENS agents, Gram-positive microorganisms predominated (Table 1), particularly Staphylococcus aureus. Despite the finding that none of the coadjuvant assays (Table 2) had sufficient sensitivity or positive predictive value to identify all septic cases, they may prove useful to pinpoint newborns at high risk due to amniotic fluid exposure to infection or to chorioamnionitis.

Assuntos

RESUMO

In order to evaluate the diagnostic usefulness of coadjuvant tests such as external auditory canal swab culture and cultures from nasopharyngeal and gastric aspirates, and to determine the incidence and etiology of early neonatal sepsis (ENS) at our Unit, 90 newborn cases whose mothers experienced premature rupture of the membranes (PRM) were studied prospectively. Although a firm diagnosis requires positive blood cultures, the difficulty in recovering microorganisms and the trauma induced by sample collection in the baby justify the search for alternative diagnostic tests. Out of 2293 childbirths during 1991, 90 mothers (4

) had PRM more than 24 hours pre-partum, while 6.9/1000 (16/2293) developed ENS. In newborns from PMR mothers, ENS percentage was 3.3

, but increased to 5.5

in association with chorionamnionitis and reached 8.8

in premature cases. Among etiological ENS agents, Gram-positive microorganisms predominated (Table 1), particularly Staphylococcus aureus. Despite the finding that none of the coadjuvant assays (Table 2) had sufficient sensitivity or positive predictive value to identify all septic cases, they may prove useful to pinpoint newborns at high risk due to amniotic fluid exposure to infection or to chorioamnionitis.

RESUMO

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) applied to outer membrane protein (OMP), extracted by a micromethod, was employed to subtype H. influenza b type I. A total of 37 H. influenzae b strains were isolated from children under 4 years of age, either with lower acute respiratory infection (LARI), or asymptomatic carriers matched according sex, socioeconomic level and seasonality. Twenty seven out of the 37 H. influenzae b strains belonged to biotype I. On the basis of OMP profiles, these 27 were classified into 8 subtypes (Figs. 2, 3, 4 and 5). The probability of two randomly chosen isolates having different OMP profiles was 0.733. The subtype termed "a" showed the greatest relative frequency and was detected both in invasive strains and in those isolated from throat samples of LARI cases and healthy children. The use of 14% SDS-PAGE allowed de detection either of a 51kD or a 49kD, as well as 25-40kD proteins, in a single run (Fig. 1). Most subtype profiles showed the 51 kD protein. Growth conditions and extraction of OMPs by our modified micromethod provide a single and inexpensive procedure within the means of the average clinical laboratory. Besides, this test is much less time-consuming than classical assays. Jointly, biotyping , serotyping and OMP profile determination, proved a useful epidemiological tool to survey H. influenzae b infection.

Assuntos

RESUMO

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) applied to outer membrane protein (OMP), extracted by a micromethod, was employed to subtype H. influenza b type I. A total of 37 H. influenzae b strains were isolated from children under 4 years of age, either with lower acute respiratory infection (LARI), or asymptomatic carriers matched according sex, socioeconomic level and seasonality. Twenty seven out of the 37 H. influenzae b strains belonged to biotype I. On the basis of OMP profiles, these 27 were classified into 8 subtypes (Figs. 2, 3, 4 and 5). The probability of two randomly chosen isolates having different OMP profiles was 0.733. The subtype termed [quot ]a[quot ] showed the greatest relative frequency and was detected both in invasive strains and in those isolated from throat samples of LARI cases and healthy children. The use of 14

SDS-PAGE allowed de detection either of a 51kD or a 49kD, as well as 25-40kD proteins, in a single run (Fig. 1). Most subtype profiles showed the 51 kD protein. Growth conditions and extraction of OMPs by our modified micromethod provide a single and inexpensive procedure within the means of the average clinical laboratory. Besides, this test is much less time-consuming than classical assays. Jointly, biotyping , serotyping and OMP profile determination, proved a useful epidemiological tool to survey H. influenzae b infection.