Thrombopoietic potential and serial repopulating ability of murine hematopoietic stem cells constitutively expressing interleukin 11.

Based on transplantation studies with bone marrow cultured under various conditions, a role of interleukin 11 (IL-11) in the self-renewal and/or the differentiation commitment of hematopoietic stem cells has been indicated. To better evaluate the in vivo effects of IL-11 on stem/progenitor cell biology, lethally irradiated mice were serially transplanted with bone marrow cells transduced with a defective retrovirus, termed MSCV-mIL-11, carrying the murine IL-11 (mIL-11) cDNA and the bacterial neomycin phosphotransferase (neo) gene. High serum levels (i.e., > 1 ng/ml) of mIL-11 in all (20/20) primary and 86% (12/14) of secondary long-term reconstituted mice, as well as 86% (12/14) of tertiary recipients examined at 6 weeks posttransplant, demonstrated persistence of vector expression subsequent to transduction of bone marrow precursors functionally definable as totipotent hematopoietic stem cells. In agreement with results obtained with human IL-11 in other myeloablation models, ectopic mIL-11 expression accelerated recovery of platelets, neutrophils, and, to some extent, total leukocytes while preferentially increasing peripheral platelet counts in fully reconstituted mice. When analyzed 5 months posttransplant, tertiary MSCV-mIL-11 recipients had a significantly greater percentage of G418-resistant colony-forming cells in their bone marrow compared with control MSCV animals. Collectively, these data show that persistent stimulation of platelet production by IL-11 is not detrimental to stem cell repopulating ability; rather, they suggest that IL-11 expression in vivo may have resulted in enhanced maintenance of the most primitive hematopoietic stem cell compartment. The prolonged expression achieved by the MSCV retroviral vector, despite the presence of a selectable marker, contrasts with the frequent transcriptional extinction observed with other retroviral vectors carrying two genes. These findings have potentially important implications for clinical bone marrow transplantation and gene therapy of the hematopoietic system.

Structure of the sodium channel pore revealed by serial cysteine mutagenesis.

The pores of voltage-gated cation channels are formed by four intramembrane segments that impart selectivity and conductance. Remarkably little is known about the higher order structure of these critical pore-lining or P segments. Serial cysteine mutagenesis reveals a pattern of side-chain accessibility that contradicts currently favored structural models based on alpha-helices or beta-strands. Like the active sites of many enzymes of known structure, the sodium channel pore consists of irregular loop regions.

Particulars of the trial and execution of George Partridge, aged 21: who was executed at Bury-St.-Edmund's, on Monday last, for the wilful murder of George Ansell, aged 9 years, within a few miles of Polstead, the late scene of Maria Martin's murder. Also, the prisoner's confession

Date of imprint from execution date, April 13, 1829 -- Capital Punishment UK site via WWW, viewed December 14, 2007.

Second war powers act, 1942. : Hearings on S. 2208, an act to further expedite the prosecution of the war. January 30 and February 2, 1942. Serial no. 10.

Mode of access: Internet.

Referees in bankruptcy : Hearings before the special subommittee on bankruptcy and reorganization, 79th ong. 1st sess. on H.R. 33 and H.R. 3338. June 25 and 26, 1945. Serial no. 4.

Mode of access: Internet.

Public laws and resolutions passed by the General Assembly at its session of ... [serial].

Title varies slightly.

Report of the Adjutant General of the state of North Carolina [serial].

Describes the activities of National Guard units including registers of officers.

United States Congressional serial set.

Mode of access: Internet.