Biomedical subjects

Dolores Bustos

Publications and source records attributed to Dolores Bustos.

3 recordsLinked to original sources

PubMed2006

Salinity-induced decrease in NADPH oxidase activity in the maize leaf blade elongation zone.

We reported previously that salinity-induced elongation constraints in the expansion zone of maize leaves are associated with reduced reactive oxygen species (ROS) production and could be alleviated by the addition of ROS. The NaCl effect was salt-specific and not osmotic. This paper explores the causes for such reduction. The decrease in ROS levels under salinity was not accompanied by increases in soluble apoplastic antioxidant activities such as superoxide dismutase, peroxidases and ascorbate. In experimental systems devoid of cell walls (protoplasts and membrane fractions) superoxide anion (O(2)(-)) production was inhibited by 50 and 100 mM NaCl, 50 microM DPI, 10 mM EGTA, and 5mM verapamil, a Ca(2+) channel inhibitor. Inhibitory effects of NaCl and reduced Ca(2+) supply were also observed in in gel assessment of O(2)(-) -generating activity. The main activity band excised from the ND-PAGE was recognized by an antibody against the C-terminal portion of the tomato gp91(phox) homolog. These results indicate the *O(2)(-) -generating activity negatively affected by NaCl was compatible with that of plasma membrane NADPH oxidase.

Antioxidants↗

PubMed2006

Loss of maternally-derived human herpesvirus-7 immunity and natural infection in Argentinian infants.

BACKGROUND: Human herpes virus-7 (HHV-7) infection is widespread throughout the world. No data are available in Argentina about loss of maternally-derived HHV-7 immunity and natural infection. OBJECTIVES: The objective of this study was to characterize the time when children lose maternal antibodies and become susceptible to natural infection. METHODS: Sera from 39 pregnant women and 207 infants between 2 and 29 months of age were tested. Determination of IgG antibodies was made by indirect immunofluorescence. RESULTS: The seropositive ratio fell in the 2-4 month group (15% seropositive) and increased between 5 months (47% seropositive) and 23 months (67%). Geometric mean titers (GMT) of the infants aged 2-4 months (GMT = 60) were statistically different (p < 0.0001, Student's t-test) to those from the group of pregnant women (GMT = 83) and those from the other infant groups (p < 0.001, least significant difference (LSD) test). The GMT of the groups between 5 and 23 months did not show significant differences whereas those of infants between 24 and 29 months (GMT = 179, 79% seropositive) were different from all the groups studied (p < 0.0001, LSD test). CONCLUSIONS: This study shows a significant association between the loss of passive HHV-7 antibody and age. HHV-7 enters the susceptible population at 5 months, leading to the high prevalence of antibodies between 24 and 29 months of age. This study also shows that natural infection by HHV-7 in children during their first years of life follows the infection pattern found in developing countries.

Adult↗

PubMed2004

Isotype immune response of IgG antibodies at the persistence and reactivation stages of human herpes virus 6 infection.

BACKGROUND: Infections with human herpes virus 6 (HHV-6) are very common. After primary infection, the virus remains latent and persists at low level in cells and tissues. Not usually associated with disease in the immunocompetent host, HHV-6 infection is a major cause of opportunistic viral infections in the immunosuppressed. The different stages of HHV-6 infection are difficult to characterize in the laboratory. OBJECTIVES: The aim of this paper was to assess the isotype patterns of IgG antibodies against HHV-6 in seropositive subjects during different stages of the virus activity. STUDY DESIGN: From a total of 190 human serum samples from 43 healthy children, 24 pregnant women and 24 patients with bone marrow transplants, 111 sera were processed by indirect immunofluorescence assay for the detection of IgG1, IgG2, IgG3 and IgG4 specific antibodies. The mean geometrical title (MGT) of the antibodies was calculated. RESULTS: All pregnant women had IgG1 (24/24; 100%; MGT 46). A 95% (41/43) of healthy infants had IgG1 (MGT 57). In bone marrow transplants, 58% (14/24) of the patients showed seroconversion (MGT 529) with an isotype response of IgG1 and IgG4 during the observation period. Remaining bone marrow transplant patients, who had the IgG without any variations (MGT 184), had isotype IgG1. CONCLUSIONS: These results revealed two different immune isotype response patterns. One of them is restrictive to IgG1 in the latent phase of HHV-6 infection in healthy children, pregnant women and transplant patients with stable levels of antibodies whereas IgG1 and IgG4 are detected in the reactivation of HHV-6 in transplant patients. The IgG isotype immune responses may contribute to the existing set of serological markers in characterizing the different stages of natural infection of HHV-6.

Adult↗