Successful treatment of autoimmunity in NZB/NZW F1 mice with monoclonal antibody to L3T4.

Autoimmune NZB/NZW mice were treated with weekly injections of monoclonal antibody (mAb) to L3T4, an antigen expressed on a distinct subpopulation of T cells that respond to class II major histocompatibility antigens. Treatment with anti-L3T4 depleted circulating target cells, reduced autoantibody production, retarded renal disease, and prolonged life relative to control mice treated either with saline or with purified nonimmune rat IgG. These findings establish that autoimmune disease in NZB/NZW mice is regulated by T cells. In contrast to mice treated with nonimmune rat IgG, mice treated with rat anti-L3T4 mAb developed little or no antibody to rat Ig. Thus, the benefits of treatment with anti-L3T4 were achieved while minimizing the risks associated with a host immune response to therapy. This study raises the possibility that treatment with mAb against Leu-3/T4, the human homologue for L3T4 might be effective in the treatment of certain autoimmune diseases in people

Mass fluxes and isofluxes of methane (CH4) at a New Hampshire fen measured by a continuous wave quantum cascade laser spectrometer

We have developed a mid‐infrared continuous‐wave quantum cascade laser direct‐absorption spectrometer (QCLS) capable of high frequency (≥1 Hz) measurements of 12CH4 and 13CH4 isotopologues of methane (CH4) with in situ 1‐s RMS image precision of 1.5 ‰ and Allan‐minimum precision of 0.2 ‰. We deployed this QCLS in a well‐studied New Hampshire fen to compare measurements of CH4 isoflux by eddy covariance (EC) to Keeling regressions of data from automated flux chamber sampling. Mean CH4 fluxes of 6.5 ± 0.7 mg CH4 m−2 hr−1 over two days of EC sampling in July, 2009 were indistinguishable from mean autochamber CH4 fluxes (6.6 ± 0.8 mgCH4 m−2 hr−1) over the same period. Mean image composition of emitted CH4 calculated using EC isoflux methods was −71 ± 8 ‰ (95% C.I.) while Keeling regressions of 332 chamber closing events over 8 days yielded a corresponding value of −64.5 ± 0.8 ‰. Ebullitive fluxes, representing ∼10% of total CH4 fluxes at this site, were on average 1.2 ‰ enriched in 13C compared to diffusive fluxes. CH4 isoflux time series have the potential to improve process‐based understanding of methanogenesis, fully characterize source isotopic distributions, and serve as additional constraints for both regional and global CH4 modeling analysis

Total column CO_2 measurements at Darwin, Australia – site description and calibration against in situ aircraft profiles

An automated Fourier Transform Spectroscopic (FTS) solar observatory was established in Darwin, Australia in August 2005. The laboratory is part of the Total Carbon Column Observing Network, and measures atmospheric column abundances of CO_2 and O_2 and other gases. Measured CO_2 columns were calibrated against integrated aircraft profiles obtained during the TWP-ICE campaign in January–February 2006, and show good agreement with calibrations for a similar instrument in Park Falls, Wisconsin. A clear-sky low airmass relative precision of 0.1% is demonstrated in the CO2 and O2 retrieved column-averaged volume mixing ratios. The 1% negative bias in the FTS X_(CO_2) relative to the World Meteorological Organization (WMO) calibrated in situ scale is within the uncertainties of the NIR spectroscopy and analysis

Boreal forest CO2 exchange and evapotranspiration predicted by nine ecosystem process models: Intermodel comparisons and relationships to field measurements

Nine ecosystem process models were used to predict CO2 and water vapor exchanges by a 150-year-old black spruce forest in central Canada during 1994–1996 to evaluate and improve the models. Three models had hourly time steps, five had daily time steps, and one had monthly time steps. Model input included site ecosystem characteristics and meteorology. Model predictions were compared to eddy covariance (EC) measurements of whole-ecosystem CO2exchange and evapotranspiration, to chamber measurements of nighttime moss-surface CO2release, and to ground-based estimates of annual gross primary production, net primary production, net ecosystem production (NEP), plant respiration, and decomposition. Model-model differences were apparent for all variables. Model-measurement agreement was good in some cases but poor in others. Modeled annual NEP ranged from −11 g C m−2 (weak CO2source) to 85 g C m−2 (moderate CO2 sink). The models generally predicted greater annual CO2sink activity than measured by EC, a discrepancy consistent with the fact that model parameterizations represented the more productive fraction of the EC tower “footprint.” At hourly to monthly timescales, predictions bracketed EC measurements so median predictions were similar to measurements, but there were quantitatively important model-measurement discrepancies found for all models at subannual timescales. For these models and input data, hourly time steps (and greater complexity) compared to daily time steps tended to improve model-measurement agreement for daily scale CO2 exchange and evapotranspiration (as judged by root-mean-squared error). Model time step and complexity played only small roles in monthly to annual predictions

On spin-rotation contribution to nuclear spin conversion in C_{3v}-symmetry molecules. Application to CH_3F

The symmetrized contribution of E-type spin-rotation interaction to conversion between spin modifications of E- and A_1-types in molecules with C_{3v}-symmetry is considered. Using the high-J descending of collisional broadening for accidental rotational resonances between these spin modifications, it was possible to co-ordinate the theoretical description of the conversion with (updated) experimental data for two carbon-substituted isotopes of fluoromethane. As a result, both E-type spin-rotation constants are obtained. They are roughly one and a half times more than the corresponding constants for (deutero)methane.Comment: 13 pages with single-spacing, REVTeX, no figures, accepted for publication in <J. Phys. B

Treatment of lupus nephritis with abatacept: the Abatacept and Cyclophosphamide Combination Efficacy and Safety Study

OBJECTIVE: To assess the efficacy and safety of a 24-week course of abatacept in the treatment of active lupus nephritis and to assess the potential of abatacept to induce clinical tolerance, defined as sustained clinical quiescence of lupus nephritis after discontinuation of immunosuppressive therapy. METHODS: Patients with active lupus nephritis (n = 134) were enrolled in a randomized, double-blind phase II add-on trial in which they received either abatacept or placebo in conjunction with the Euro-Lupus Nephritis Trial regimen of low-dose cyclophosphamide (CYC) followed by azathioprine (AZA). The primary efficacy outcome was the frequency of complete response at week 24. Thereafter, patients who met either complete or partial response criteria continued blinded treatment through week 52. During this phase of the study, subjects in the abatacept treatment group in whom a complete response was achieved at week 24 discontinued immunosuppressive therapy other than prednisone (10 mg/day). RESULTS: There were no statistically significant differences between groups with respect to the primary outcome or any of the secondary outcomes, including measures of safety. A complete response was achieved in 33% of the subjects in the treatment group and in 31% of the subjects in the control group at week 24. Fifty percent of the subjects in the treatment group who met complete response criteria and therefore discontinued immunosuppressive therapy at week 24 maintained their complete response status through week 52. CONCLUSION: The addition of abatacept to a regimen of CYC followed by AZA did not improve the outcome of lupus nephritis at either 24 or 52 weeks. No worrisome safety signals were encountered