Microglial activation decreases retention of the protease inhibitor saquinavir: implications for HIV treatment.

Background: Active HIV infection within the central nervous system (CNS) is confined primarily to microglia. The glial cell compartment acts as a viral reservoir behind the blood-brain barrier. It provides an additional roadblock to effective pharmacological treatment via expression of multiple drug efflux transporters, including P-glycoprotein.

Full-length sequence, regulation and developmental studies of a second vitellogenin gene from the American dog tick, Dermacentor variabilis.

Vitellogenin (Vg) is the precursor of vitellin (Vn) which is the major yolk protein in eggs. In a previous report, we isolated and characterized the first Vg message from the American dog tick Dermacentor variabilis. In the current study, we describe a second Vg gene from the same tick.

Molecular characterization, tissue-specific expression and RNAi knockdown of the first vitellogenin receptor from a tick.

This is the first full-length message for a vitellogenin receptor (VgR) sequenced from ticks. VgRs, members of the low-density lipoprotein receptor (LDLR) superfamily, mediate the uptake of the yolk protein, vitellogenin (Vg), from the hemolymph. The VgR message from the American dog tick, Dermacentor variabilis (GenBank accession No.

Sequence and the developmental and tissue-specific regulation of the first complete vitellogenin messenger RNA from ticks responsible for heme sequestration.

The first full-length mRNA for vitellogenin (Vg) from ticks was sequenced. This also represents the first complete sequence of Vg from the Chelicerata and of a heme binding Vg. The Vg cDNA from the American dog tick, Dermacentor variabilis was 5744nt in length (GenBank Accession number AY885250), which coded for a protein of 1843 aa with a calculated molecular weight of 208 kD.

The flounder organic anion transporter fOat has sequence, function, and substrate specificity similarity to both mammalian Oat1 and Oat3.

The flounder renal organic anion transporter (fOat) has substantial sequence homology to mammalian basolateral organic anion transporter orthologs (OAT1/Oat1 and OAT3/Oat3), suggesting that fOat may have functional properties of both mammalian forms. We therefore compared uptake of various substrates by rat Oat1 and Oat3 and human OAT1 and OAT3 with the fOat clone expressed in Xenopus oocytes. These data confirm that estrone sulfate is an excellent substrate for mammalian OAT3/Oat3 transporters but not for OAT1/Oat1 transporters.

In vivo role of 20-hydroxyecdysone in the regulation of the vitellogenin mRNA and egg development in the American dog tick, Dermacentor variabilis (Say).

Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4 d after the 50 x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not engorged to repletion.