A Unique Carrier for Delivery of Therapeutic Compounds beyond the Blood-Brain Barrier

BACKGROUND: Therapeutic intervention in many neurological diseases is thwarted by the physical obstacle formed by the blood-brain barrier (BBB) that excludes most drugs from entering the brain from the blood. Thus, identifying efficacious modes of drug delivery to the brain remains a "holy grail" in molecular medicine and nanobiotechnology. Brain capillaries, that comprise the BBB, possess an endogenous receptor that ferries an iron-transport protein, termed p97 (melanotransferrin), across the BBB. Here, we explored the hypothesis that therapeutic drugs "piggybacked" as conjugates of p97 can be shuttled across the BBB for treatment of otherwise inoperable brain tumors. APPROACH: Human p97 was covalently linked with the chemotherapeutic agents paclitaxel (PTAX) or adriamycin (ADR) and following intravenous injection, measured their penetration into brain tissue and other organs using radiolabeled and fluorescent derivatives of the drugs. In order to establish efficacy of the conjugates, we used nude mouse models to assess p97-drug conjugate activity towards glioma and mammary tumors growing subcutaneously compared to those growing intracranially. PRINCIPAL FINDINGS: Bolus-injected p97-drug conjugates and unconjugated p97 traversed brain capillary endothelium within a few minutes and accumulated to 1-2% of the injected by 24 hours. Brain delivery with p97-drug conjugates was quantitatively 10 fold higher than with free drug controls. Furthermore, both free-ADR and p97-ADR conjugates equally inhibited the subcutaneous growth of gliomas growing outside the brain. Evocatively, only p97-ADR conjugates significantly prolonged the survival of animals bearing intracranial gliomas or mammary tumors when compared to similar cumulated doses of free-ADR. SIGNIFICANCE: This study provides the initial proof of concept for p97 as a carrier capable of shuttling therapeutic levels of drugs from the blood to the brain for the treatment of neurological disorders, including classes of resident and metastatic brain tumors. It may be prudent, therefore, to consider implementation of this novel delivery platform in various clinical settings for therapeutic intervention in acute and chronic neurological diseases

Gender differences in competition and dominance during marriedcouples group therapy. Social Psychology Quarterly

Previous research on sanze-sex interaction has documented competitive patterns for males, but not for females. By contrast, some studies characterize cross-sex interaction as competitive; other studies, as noncotnpetitive. To extend research on the processes of competition and dominance in same- and cross-sex interaction, the present study examines verbal interaction sequences that occurred during two brief psychotherapy groups conducted for the same set oj five married couples. All interaction sequences have been classified according to the Ericson-Rogers Relational Coding System, and patterns analyzed by means of a log-linear statistical procedure. For same-sex interaction, findings document more indiscriminant competition between males than between females. These results extend previous findings. For cross-sex interaction, a complex pattern of competition and dominance is observed. Although females compete with males under certain conditions, males do not compete with females. However, males apparently interrupt females freely, thus suggesting that males assume a dominant position. Females tend to "interrupt back, " an indication that male dominance is not acceptable. However, females are also more submissive toward husbands than toward other males. The question remains whether these patterns are applicable to a more general popula-tion