Actinomyces in Chronic Granulomatous Disease: An Emerging and Unanticipated Pathogen

Chronic granulomatous disease (CGD) is a rare inherited disease of the phagocyte NADPH oxidase system that causes defective production of toxic oxygen metabolites, impaired bacterial and fungal killing, and recurrent life-threatening infections, mostly by catalase-producing organisms. We report for the first time, to our knowledge, chronic infections with Actinomyces species in 10 patients with CGD. Actinomycosis is a chronic granulomatous condition that commonly manifests as cervicofacial, pulmonary, or abdominal disease, caused by slowly progressive infection with oral and gastrointestinal commensal Actinomyces species. Treatment of actinomycosis is usually simple in immunocompetent individuals, requiring long-term, high-dose intravenous penicillin, but is more complicated in those with CGD because of delayed diagnosis and an increased risk of chronic invasive or debilitating disease.

The Carnegie Astrometric Planet Search Program

We are undertaking an astrometric search for gas giant planets and browndwarfs orbiting nearby low mass dwarf stars with the 2.5-m du Pont telescope atthe Las Campanas Observatory in Chile. We have built two specializedastrometric cameras, the Carnegie Astrometric Planet Search Cameras (CAPSCam-Sand CAPSCam-N), using two Teledyne Hawaii-2RG HyViSI arrays, with the cameras'design having been optimized for high accuracy astrometry of M dwarf stars. Wedescribe two independent CAPSCam data reduction approaches and present adetailed analysis of the observations to date of one of our target stars, NLTT48256. Observations of NLTT 48256 taken since July 2007 with CAPSCam-S implythat astrometric accuracies of around 0.3 milliarcsec per hour are achievable,sufficient to detect a Jupiter-mass companion orbiting 1 AU from a late M dwarf10 pc away with a signal-to-noise ratio of about 4. We plan to follow about 100nearby (primarily within about 10 pc) low mass stars, principally late M, L,and T dwarfs, for 10 years or more, in order to detect very low mass companionswith orbital periods long enough to permit the existence of habitable,Earth-like planets on shorter-period orbits. These stars are generally toofaint and red to be included in ground-based Doppler planet surveys, which areoften optimized for FGK dwarfs. The smaller masses of late M dwarfs also yieldcorrespondingly larger astrometric signals for a given mass planet. Our searchwill help to determine whether gas giant planets form primarily by coreaccretion or by disk instability around late M dwarf stars.

Borrelia burgdorferiStimulates Macrophages to Secrete Higher Levels of Cytokines and Chemokines thanBorrelia afzeliiorBorrelia garinii

To delineate the inflammatory potential of the 3 pathogenic species of Borrelia burgdorferi sensu lato, we stimulated monocyte-derived macrophages from healthy human donors with 10 isolates each of B. burgdorferi, Borrelia afzelii, or Borrelia garinii recovered from erythema migrans skin lesions of patients with Lyme borreliosis from the United States or Slovenia. B. burgdorferi isolates from the United States induced macrophages to secrete significantly higher levels of interleukin (IL)-8, CCL3, CCL4, IL-6, IL-10, and tumor necrosis factor than B. garinii or B. afzelii isolates. Consistent with this response in cultured macrophages, chemokine and cytokine levels in serum samples of patients from whom the isolates were obtained were significantly greater in B. burgdorferi-infected patients than in B. afzelii- or B. garinii-infected patients. These results demonstrate in vitro and in vivo that B. burgdorferi has greater inflammatory potential than B. afzelii and B. garinii, which may account in part for variations in the clinical manifestations of Lyme borreliosis.

The Effect of Imatinib on Cytomegalovirus Reactivation in Hematopoietic Cell Transplantation

In vitro studies have shown possible antiviral effects of tyrosine kinase inhibitors. In a retrospective study, we show that use of the tyrosine kinase inhibitor imatinib does not appear to reduce cytomegalovirus reactivation during the first 100 days after transplantation in a cohort of hematopoietic cell transplant recipients.

Pollination Efficiency and the Evolution of Specialized Deceptive Pollination Systems

The ultimate causes of evolution of highly specialized pollination systems are little understood. We investigated the relationship between specialization and pollination efficiency, defined as the proportion of pollinated flowers relative to those that experienced pollen removal, using orchids with different pollination strategies as a model system. Rewarding orchids showed the highest pollination efficiency. Sexually deceptive orchids had comparably high pollination efficiency, but food-deceptive orchids had significantly lower efficiency. Values for pollinator sharing (a measure of the degree of generalization in pollination systems) showed the reverse pattern, in that groups with high pollination efficiency had low values of pollinator sharing. Low pollinator sharing may thus be the basis for efficient pollination. Population genetic data indicated that both food- and sexually deceptive species have higher degrees of among-population gene flow than do rewarding orchids. Thus, the shift from food to sexual deception may be driven by selection for more efficient pollination, without compromising the high levels of gene flow that are characteristic of deceptive species.

Reply to Hage et al

Preterm Infants' T Cell Responses to Inactivated Poliovirus Vaccine

The antigen-specific T cell responses of preterm infants to immunization are not well understood. The aim of the present study was to compare the T cell responses of preterm infants after inactivated poliovirus vaccination with those of term infants.

Kuiper Belt Object Occultations: Expected Rates, False Positives, and Survey Design

A novel method of generating artificial scintillation noise is developed andused to evaluate occultation rates and false positive rates for surveys probingthe Kuiper Belt with the method of serendipitous stellar occultations. Athorough examination of survey design shows that: (1) diffraction-dominatedoccultations are critically (Nyquist) sampled at a rate of 2 Fsu^{-1},corresponding to 40 s^{-1} for objects at 40 AU, (2) occultation detectionrates are maximized when targets are observed at solar opposition, (3) MainBelt Asteroids will produce occultations lightcurves identical to those ofKuiper Belt Objects if target stars are observed at solar elongations of: 116deg 7-8 sigmashould be adopted to ensure that viable candidate events can be disentangledfrom false positives.

THE ACTIVITY AND VARIABILITY OF THE SUN AND SUN-LIKE STARS. II. CONTEMPORANEOUS PHOTOMETRY AND SPECTROSCOPY OF BRIGHT SOLAR ANALOGS

We present 14 years of contemporaneous photometric and spectroscopic observations of 28 solar analog stars, taken with the Tennessee State University Automatic Photometric Telescopes at Fairborn Observatory and the Solar-Stellar Spectrograph at Lowell Observatory. These are the best observed and most nearly Sun-like of the targets in our magnitude-limited (V 7.5) sample. The correlations between luminosity and activity reveal the expected inverse activity-brightness correlations for active stars. Strong direct correlations between activity and brightness are not prevalent for the less active solar age stars, but are precision limited. The Sun does not appear to have unusually low photometric variability when compared with the most Sun-like inactive solar analogs. We present evidence that the activity index R HK is not a good discriminant of Maunder Minimum candidate stars. On the basis of a star that appears to have transitioned from a low-variability state to a cycling state, we investigate the regime in which stars might switch from faculae-dominated to spot-dominated variations.

NONDETECTION OF THE NEPTUNE-MASS PLANET REPORTED AROUND GJ 176