Lithium chloride inhibits the expression and secretion of insulin-like growth factor-binding protein-1.

Insulin-like growth factor-binding protein-1 (IGFBP-1) regulates IGF availability for glucose homeostasis. The IGFBP-1 promoter shares common regulatory response elements with phosphoenol pyruvate carboxykinase (PEPCK), the expression and activity of which is inhibited by lithium chloride, associated with an inhibition of glycogen synthase kinase (GSK)-3 activity, in the rat hepatoma cell line H4-II-E. We therefore determined the effect of lithium chloride on IGFBP-1 expression and secretion in H4-II-E cells. Lithium chloride inhibited IGFBP-1 secretion in a dose response and reversible manner by approx 80% during 5-h and 16-h incubations. An inhibitory effect on IGFBP-1 mRNA expression was observed at 2 h. The inhibitory effect of lithium and insulin were not additive when used alone, but inhibition by lithium occurred when insulin action was blocked by activating AMP-activated protein kinase with 5-aminoimidazole-4-carboxamide-riboside (AICAR). These findings suggest that GSK-3 inhibition, or another pathway activated by lithium, may be involved in a pathway controlling IGFBP-1, inhibiting synthesis when insulin activity is absent or impaired.

MtDNA sequences support monophyly of Hemispingus tanagers.

Tanagers of the genus Hemispingus comprise an array of 12 recognized species of rather dull-colored tanagers restricted to Andean forests. Four of these species are polytypic, with as many as seven subspecies recognized for H. superciliaris. Taxonomic relationships within this group, and with similar-looking Basileuterus warblers, have been confusing and not well understood. We used partial DNA sequences of the mitochondrial ND2 gene and a set of morphological characters to study their phylogenetic relationships. Our molecular dataset strongly supports the monophyly of Hemispingus (including the warbler-like species and the finch-like H. rufosuperciliaris) compared to other nine-primaried oscines (Ramphocelus, Chlorospingus, Atlapetes/Buarremon, Basileuterus) and indicates either that Atlapetes/Buarremon could be tanagers or that Chlorospingus could be finches. We propose a phylogeny containing three major clades: mostly greenish eye-browed birds (trifasciatus, atropileus, auricularis, calophrys), mostly gray warbler-like birds (superciliaris, verticalis, xanthophthalmus), and mostly ochraceous birds (rufosuperciliaris and goeringi, piurae, frontalis, melanotis). The relationships among these three clades are left unresolved. We suggest species status for H. auricularis and H. piurae. Our molecular data suggest that most of the diversity in Hemispingus tanagers predates the period of marked ecoclimatic fluctuations in the upper Pleistocene.

Pioneer 6: Measurement of Transient Faraday Rotation Phenomena Observed during Solar Occultation.

Pioneer 6, which was launched into orbit around the sun on 16 December 1965, was occulted by the sun in the last half of November 1968. During the period in which the spacecraft was occulted by the solar corona, the S-band telemetry carrier underwent Faraday rotation as a result of this anisotropic plasma. The NASA-Jet Propulsion Laboratory 210-foot (64-meter) antenna of the Deep Space Network at Barstow, California, which was equipped with an automatic polarization tracking system, was used to measure this effect. Three large-scale transient phenomena were observed. The measurement of these phenomena indicated that Faraday rotation on the order of 40 degrees occurred. The duration of each phenomenon was approximately 2 hours. These phenomena appear to be correlated with observations of solar radio bursts with wavelengths in the dekametric region.