czcD gene from Bacillus megaterium and Microbacterium liquefaciens as a potential nickel–vanadium soil pollution biomarker

Metals are among the most prevalent pollutants released into the environment. For these reasons, the use of biomarkers for environmental monitoring of individuals and populations exposed to metal pollution has gained considerable attention, offering fast and sensitive detection of chemical stress in organisms. There are different metal resistance genes in bacteria that can be used as biomarkers, including cation diffusion facilitators carrying metal ions; the prototype is the cobalt–zinc–cadmium transporter (czcD). The present study reports the expression changes in the czcD gene in Bacillus megaterium and Microbacterium liquefaciens under nickel and vanadium exposure by real-time polymerase chain reaction. The nickel–vanadium-resistant strains of B. megaterium and M. liquefaciens used in this study were isolated from mine tailings in Guanajuato, Mexico. The czcD gene showed high expression under exposure to 200 ppm of Ni and 200 ppm of V during the logarithmic growth phase of M. liquefaciens in PHGII liquid media. In contrast, no changes were observed in B. megaterium during logarithmic and stationary growth, perhaps due to the gene having differential expression during the growth phases. The expression profiles obtained for czcD show the possibility of using this gene from M. liquefaciens as a biomarker of nickel and vanadium pollution in microorganisms.     

Combined meningococcal serogroup A and W135 outer-membrane vesicles activate cell-mediated immunity and long-term memory responses against non-covalent capsular polysaccharide A

Outer-membrane vesicles (OMVs) have inherent adjuvant properties, and many vaccines use OMV as vaccine components. Utilizing the adjuvant properties of OMV could lead to the formulation of vaccines that are less expensive and potentially more immunogenic than covalently conjugated polysaccharide vaccines. We evaluated the adjuvant effect in Balb/c mice of combinations of OMV from Neisseria meningitidis serogroup A and W₁₃₅ as compared to that of the non-covalently conjugated capsular polysaccharide A. Both antigens were adsorbed onto aluminum hydroxide. The mice were given a booster dose of plain polysaccharide A to stimulate an immunologic memory response. Subclasses determination and cytokine assays demonstrated the capacity of OMV to induce a IgG2a/IgG2b isotype profile and IFN-γ production, suggesting the induction of a Th1 pattern immune response. Lymphoproliferative responses to OMVs were high, with affinity maturation of antibodies observed. Bactericidal titers after the booster dose were also observed. Memory B cells and long-term memory T cells were also detected. The results of this study indicate that combined meningococcal serogroup A and W₁₃₅ OMV can activate cell-mediated immunity and induce a long-term memory response.     

The hypothalamus-pituitary-thyroid axis in teleosts and amphibians: Endocrine disruption and its consequences to natural populations

Teleosts and pond-breeding amphibians may be exposed to a wide variety of anthropogenic, waterborne contaminants that affect the hypothalamus-pituitary-thyroid (HPT) axis. Because thyroid hormone is required for their normal development and reproduction, the potential impact of HPT-disrupting contaminants on natural teleost and amphibian populations raises special concern. There is laboratory evidence indicating that persistent organic pollutants, heavy metals, pharmaceutical and personal care products, agricultural chemicals, and aerospace products may alter HPT activity, development, and reproduction in teleosts and amphibians. However, at present there is no evidence to clearly link contaminant-induced HPT alterations to impairments in teleost or amphibian population health in the field. Also, with the exception of perchlorate for which laboratory studies have shown a direct link between HPT disruption and adverse impacts on development and reproductive physiology, little is known about if or how other HPT-disrupting contaminants affect organismal performance. Future field studies should focus on establishing temporal associations between the presence of HPT-disrupting chemicals, the occurrence of HPT alterations, and adverse effects on development and reproduction in natural populations; as well as determining how complex mixtures of HPT contaminants affect organismal and population health.     

Effect of hematologic treatment on the growth and puberty of children with thalassemia major

This study reports on the endocrine abnormalities associated with delayed growth and puberty, observed in 10 children presenting with thalassemia major. Hormonal changes were followed up during treatment with regular transfusions and efficient chelating agents. Recovery of growth and onset of puberty were observed in most cases. When puberty was delayed, an associated substitutive treatment with sexual hormones was useful. In one case only, an isolated gonadotropic deficiency could be proven. In all cases STH, TSH and PRL secretions were normal. Without efficient and early treatment, the main consequence of the disease with respects to growth seems to be the risk of delayed puberty, mainly functional, or rarely hypogonadotropic due to definite LH and FSH deficiency.     

Maternal and childhood nutrition and later blood pressure levels in young Guatemalan adults

BACKGROUND: Low birth weight and subsequent rapid child growth are associated with later blood pressure levels. The role of maternal and child nutrition in this association remains unclear. METHODS: We studied 450 men and women (ages 21-29 years) born during a randomized trial of protein-energy supplementation (Atole) vs low energy/no protein supplementation (Fresco) in pregnancy and early childhood in four rural Guatemalan villages from 1969 to 1977. RESULTS: Protein-energy supplementation was not associated with differences in blood pressure in adulthood (diastolic blood pressure (DBP): beta = 0.69 mm Hg, 95% confidence internal (CI) (20.82-2.19); P = 0.37; systolic blood pressure (SBP): beta = 0.17 mm Hg, 95% CI (21.68-2.02); P = 0.86). Within the Atole group, maternal height was associated with later SBP (0.22 mm Hg/cm, 95% CI (20.002-0.45); P = 0.05). No other associations between maternal nutritional status, birth size, child growth, or supplement intake were observed for adult blood pressure. CONCLUSIONS: Our data do not support the role of maternal nutrition during pregnancy, birth size, or early child growth in programming adult blood pressure. Likewise, we found no effect of protein-energy supplementation in pregnancy or in early childhood on blood pressure in young adults.