Fetal liver and bone marrow JORO 75+ lymphocyte progenitors are precursors of CD4+8- TCR/CD3- early thymocytes.

We show here that cell sorter purified JORO 75+ lymphocyte progenitors from fetal liver or bone marrow of adult mice give rise in vitro to CD4+8- T cell receptor (TCR)/CD3- early thymocytes and CD4+8- TCR/CD3+ thymocyte subsets after coculture with the EH6 subcapsular thymic epithelial cell line, recombinant interleukin 7 (rIL-7) and F (supernatants from the FLS4.1 fetal liver stromal cell line). We find that in cultures that had additionally received rIL-2, CD4-8+ TCR/CD3+ cells were also generated. The results strongly suggest that fetal liver and marrow JORO 75+ lymphocyte progenitors are precursors to the early CD4+8- TCR/CD3- intrathymic population previously identified in the adult mouse. The EH6 subcapsular thymic epithelial cell line should facilitate the study of the molecular events responsible for very early stages of T cell development including T lymphocyte-lineage commitment.

Paclitaxel liposome aerosol treatment induces inhibition of pulmonary metastases in murine renal carcinoma model.

The present studies were undertaken to evaluate the pulmonary pharmacokinetics and therapeutic efficacy of paclitaxel (PTX) administered by aerosol. PTX was encapsulated into dilauroylphosphatidylcholine liposomal formulations (PTX-DLPC). The deposition and clearance of PTX-DLPC in the lungs administered by aerosol or i.v. at comparative doses was performed, and PTX was quantitatively determined in tissue extracts by high-performance liquid chromatography analysis. The murine renal carcinoma (Renca) pulmonary metastases model was used to determine the therapeutic effect of drug formulation administered by aerosol. PTX-DLPC aerosols were generated with the Aero-Mist jet nebulizer (cis-USA). The most effective schedule of treatment was when mice inhaled the drug for 30 min 3 days per week. There was a significant reduction of the lung weights and reduced number of visible tumor foci on the lung surfaces of mice treated with PTX aerosol (P < 0.004 and P < 0.01, respectively) compared with control groups. Inhalation of PTX-DLPC also led to prolonged survival in mice inoculated with Renca cells. The results of the present studies demonstrate the therapeutic potential of aerosol technology for lung cancer treatment.

Improved respiratory delivery of the anticancer drugs, camptothecin and paclitaxel, with 5% CO2-enriched air: pharmacokinetic studies.

PURPOSE: To increase pulmonary deposition of anticancer liposome aerosols in mice by modulation of respiratory physiology through the addition of 5% CO2 to the air source used to generate the aerosols. Breathing CO2-enriched aerosol increases pulmonary ventilation with concurrent increased deposition of inhaled particles. METHODS: Dilauroylphosphatidylcholine liposome formulations of two anticancer drugs, paclitaxel (PTX) and camptothecin (CPT), were investigated. The aerosol droplet size was measured using an Andersen cascade impactor. Drug concentrations in aerosol droplet fractions and tissues were determined by HPLC analysis. ICR mice were exposed to each liposome aerosol for 30 min. For each drug, one group of mice inhaled the drug-liposome aerosol generated with a mixture of 5% CO2 in air and another group inhaled the drug-liposome aerosols produced with normal air. Tissue distribution and pharmacokinetics were determined for both drug delivery systems. RESULTS: Significantly higher concentrations of PTX and CPT were found in organs of mice exposed to 5% CO2-air aerosols compared to organs of mice exposed to normal air aerosols. The highest concentrations of drug were detected in the lungs and were two- to fourfold higher with 5% CO2-air aerosols than with aerosols generated with normal air. Higher concentrations were also detected in liver, spleen, kidneys, blood, and brain. CONCLUSION: 5% CO2 enrichment of air increased respiratory tract deposition of inhaled aerosol particles containing PTX and CPT.

Cyclosporin A aerosol improves the anticancer effect of paclitaxel aerosol in mice.

Paclitaxel (PTX) is a lipophilic agent with broad anticancer activity. In the present study we examined the antitumor effect and toxicity of co-administration of cyclosporine A (CsA) and PTX in liposomal aerosol using the Renca lung metastases mouse model. The untreated and PTX-only groups exhibited cancer growth while CsA aerosol plus PTX had more favorable effects on tumor growth. Weight loss was seen in mice treated with CsA/PTX+CsA by day 9 to 22. Histopathological examination showed no toxicity following treatment. The findings offer evidence that a combination of CsA and PTX may be suitable for aerosol treatment of lung cancer if it is possible to control toxicity of the therapy.

In vitro generation of hematopoietic stem cells from an embryonic stem cell line.

Hematopoietic stem cells (HSC) are unique in that they give rise both to new stem cells (self-renewal) and to all blood cell types. The cellular and molecular events responsible for the formation of HSC remain unknown mainly because no system exists to study it. Embryonic stem (ES) cells were induced to differentiate by coculture with the stromal cell line RP010 and the combination of interleukin (IL) 3, IL-6, and F (cell-free supernatants from cultures of the FLS4.1 fetal liver stromal cell line). Cell cytometry analysis of the mononuclear cells produced in the cultures was consistent with the presence of PgP-1+ Lin- early hematopoietic (B-220- Mac-1- JORO 75- TER 119-) cells and of fewer B-220+ IgM- B-cell progenitors and JORO 75+ T-lymphocyte progenitors. The cell-sorter-purified PgP-1+ Lin- cells produced by induced ES cells could repopulate the lymphoid, myeloid, and erythroid lineages of irradiated mice. The ES-derived PgP-1+ Lin- cells must possess extensive self-renewal potential, as they were able to produce hematopoietic repopulation of secondary mice recipients. Indeed, marrow cells from irradiated mice reconstituted (15-18 weeks before) with PgP-1+ Lin- cell-sorter-purified cells generated by induced ES cells repopulated the lymphoid, myeloid, and erythroid lineages of secondary mouse recipients assessed 16-20 weeks after their transfer into irradiated secondary mice. The results show that the culture conditions described here support differentiation of ES cells into hematopoietic cells with functional properties of HSC. It should now be possible to unravel the molecular events leading to the formation of HSC.

Detection frequency by thin-layer chromatography of phosphatidylglycerol in amniotic fluid with clinically functional pulmonary surfactant.

Densitometric lecithin/sphingomyelin ratios (LSR) and the presence of phosphatidylglycerol (PG) were determined for 735 consecutively received amniotic fluids. Of the 371 fluids with "mature" LSR between 2.0 and 4.5, more than one-third lacked detectable PG. Clinical outcomes for the 305 of the total group that were delivered within 72 h of sampling were also determined. Respiratory distress syndrome (RDS) did not occur in the 239 cases with LSR greater than or equal to 2.0, even when, as in 43 instances, PG was not detected. When the LSR was greater than or equal to 2.0, transient tachypnea was more prevalent in the absence of detectable PG (PG detected, 3% transient tachypnea; PG undetected, 16% transient tachypnea). Of the 103 cases where PG was undetected, 58% exhibited no respiratory problems. Even in the 60 cases where the LSR was less than 2.0 and PG was not detected, 42% of the cases were free of respiratory problems. RDS did not occur in any case where PG was detected, even in the six where the LSR was less than 2.0. We evaluate these results in light of various contradictory reports in the literature.

Glucuronides of monohydroxylated bile acids: specificity of microsomal glucuronyltransferase for the glucuronidation site, C-3 configuration, and side chain length.

The ability of rat liver microsomes to catalyze UDP-glucuronic acid-dependent glucuronidation of monohydroxy-bile acids was examined. The following bile acids were used as substrates, each as the 3 alpha and 3 beta epimer: 3-hydroxy-5 beta-cholanoic acid (C24), 3-hydroxy-5 beta-norcholanoic acid (C23), 3-hydroxy-5 beta-bisnorcholanoic acid (C22), 3-hydroxy-5 beta-pregnan-21-oic acid (C21), and 3-hydroxy-5 beta-androstane-17 beta-carboxylic acid (C20). The corresponding glucuronides were chemically synthesized to serve as standards and were characterized by thin-layer and gas-liquid chromatography as well as by nuclear magnetic resonance. Enzymatic glucuronidation reactions were optimized with respect to pH for each product formed and the kinetic parameters for each reaction were measured. Analytical techniques necessary to separate products from unreacted substrates and to identify them included thin-layer chromatography, gas-liquid chromatography, and nuclear magnetic resonance. It was found that the 3 alpha epimers of the five bile acids listed above enzymatically formed 3-O-glucuronides, C24 being the best substrate, followed by C21 and C20; C22 and C23 gave rise to only small amounts of this product. The 3 beta epimers of all bile acids tested were poorer substrates, although by a factor that varied widely. In addition to the expected hydroxyl-linked glucuronide, three of the 3 alpha-bile acids (C23, C22, and C20) and at least one 3 beta-bile acid (C20), gave rise to a novel metabolite in which the 1-OH of glucuronic acid was esterified with the steroidal carboxyl group (carboxyl-linked glucuronide).

Transgene expression in mouse airway epithelium by aerosol gene therapy with PEI-DNA complexes.

Gene therapy targeted at the respiratory epithelium holds therapeutic potential for diseases such as cystic fibrosis and alpha-1 anti-trypsin deficiency. A variety of approaches such as intranasal or intratracheal instillation and aerosol delivery have been utilized to target genes to the airways. Polyethylenimine (PEI), a linear or branched polycationic polymer, has been used for delivery of genes to various organs. In this study, using fluorescein isothiocyanate (FITC)-labeled branched PEI, we initially examined the localization of PEI in the lungs after aerosol delivery to Balb/C mice. Further, after aerosol delivery of PEI-CAT DNA, in situ immunostaining for chloramphenicol acetyl transferase (CAT) protein was used to localize the transgene expression within the lungs. Immunohistochemistry for CAT, as well as localization of FITC-labeled PEI, revealed that after aerosol delivery, the PEI-DNA complexes deposit and subsequently transfect most of the epithelial cells in the conducting airways (including the peripheral airways). High levels of CAT were detected at 24 h after aerosol exposure and significant CAT expression was detected in the lungs up to 28 days after a single aerosol exposure. The data suggest that aerosol delivery of PEI-DNA complexes could be effective for the treatment of pulmonary diseases such as cystic fibrosis and alpha-1 anti-trypsin deficiency.