Effect of zinc upon human and murine cell viability and differentiation.

Most zinc studies show its benefits or changes that coincide with its deficiency, but some have reported damages by supplements. In this work, the effects of zinc in different cell lines (U-937, human monocytes, and murine bone marrow cells) were analyzed. The cells were put in their specific culture medium either alone or with a stimulant [1-phorbol 12-myristate 13-acetate (PMA) for U-937 and monocytes, granulocyte macrophage colony stimulating factor (GM-CSF) for bone marrow cells]. These preparations, with or without zinc (0.05 to 1.0 mM), were incubated and microscopically analyzed on days 3, 9, and 11. The viability of all cells cultivated with 0.05 and 0.1 mM of zinc was similar to that of the controls without zinc (90%). With 1.0 mM of zinc, the viability diminished (p < 0.005) to 80% in U-937 and to 50% in monocytes and bone marrow cells; the number of cells increased in the three lines, but there was no differentiation. We conclude that the effects observed with different doses of zinc vary not only among the different species but also according to the time the cells were exposed to the metal. The same doses of zinc can have either a stimulatory or an inhibitory effect.

[Inflammatory markers associated with asthma and body mass index]. / Marcadores inflamatorios relacionados con asma e índice de masa corporal.

BACKGROUND: Obesity can be considered as a chronic inflammatory process, which is associated with many different diseases. Its relationship with asthma has been poorly evaluated. Obesity induces the production of leptin and cytokines in asthmatic patients, and it is associated with worse disease severity. OBJECTIVE: To determine the relationship between obesity (according to body mass index, BMI), asthma severity and leptin, IL-1 beta, and IL-4 concentrations in blood. PATIENTS AND METHOD: 37 adult allergic asthmatic patients where involved in the study, each of them with different clinical disease stages, evaluated by GINA international diagnosis and treatment criteria 2004. BMI was determined and peripheral blood samples were taken to determine IL-1 beta, IL-4, and leptin concentrations. RESULTS: BMI and asthma severity shown a moderate correlation (r = 0.528), according to Colton's criteria. BMI and leptin correlation levels were r = 0.425 with p < 0.025. Plasma leptin levels and asthma severity shown a significant difference in the groups composed of intermittent mild asthma and persistent severe asthma (p < 0.02). There was a non significant correlation between BMI and asthma severity with IL-4, and finally there was no correlation with IL-1 beta. This results suggest that asthmatic patients with a BMI3 30 have higher plasma leptin concentrations and worse disease severity, mainly in women.

Salivary excretion of rabies virus by healthy vampire bats.

Salivary excretion of rabies virus was evaluated in 14 adult vampire bats (Desmodus rotundus) intramuscularly injected with a large dose (10(6) MICLD50) of vampire rabies virus variant CASS88. Saliva samples were obtained from surviving bats every other day for 30 days, then weekly for 2 months, and finally 1 and 2 years later. Rabies virus was isolated in murine neuroblastoma cells and in randomly selected cases by PCR. Rabies virus was not detected in the saliva of any of the 11 animals that succumbed (somewhat early) to rabies challenge, nor in the control bats. In contrast, virus was detected early, and only once (days 6, 6 and 21) in each of the three animals that survived rabies challenge and remained healthy for at least 2 years after challenge. At that time even vigorous dexamethasone and cyclosporine administration failed to provoke further viral excretion.