The Discovery of Two New Satellites of Pluto

Pluto's first known moon, Charon, was discovered in 1978 (Christy 1978) and has a diameter about half that of Pluto (Buie 1992,Young 1994, Sicardy 2005), which makes it larger relative to its primary than any other moon in the Solar System. Previous searches for other satellites around Pluto have been unsuccessful (Stern 1991, Stern 1994, Stern 2003), but they were not sensitive to objects <=150 km in diameter and there are no fundamental reasons why Pluto should not have more satellites (Stern 1994). Here we report the discovery of two additional moons around Pluto, provisionally designated S/2005 P1 (hereafter P1) and S/2005 P2 (hereafter P2), which makes Pluto the first Kuiper belt object (KBO) known to have multiple satellites. These new satellites are much smaller than Charon (diameter~1200 km), with P1 ranging in diameter from 60-165 km depending on the surface reflectivity, and P2 about 20% smaller than P1. Although definitive orbits cannot be derived, both new satellites appear to be moving in circular orbits in the same orbital plane as Charon, with orbital periods of ~38 days (P1) and ~25 days (P2). The implications of the discovery of P1 and P2 for the origin and evolution of the Pluto system, and for the satellite formation process in the Kuiper belt, are discussed in a companion paper (Stern 2006).Comment: Preprint of a paper accepted for publication in the journal Natur

Self-complementary AAV Virus (scAAV) Safe and Long-term Gene Transfer in the Trabecular Meshwork of Living Rats and Monkeys

AAV vectors produce stable transgene expression and elicit low immune response in many tissues. AAVs have been the vectors of choice for gene therapy for the eye, in particular the retina. scAAVs are modified AAVs that bypass the required second-strand DNA synthesis to achieve transcription of the transgene. The goal was to investigate the ability of AAV vectors to induce long-term, safe delivery of transgenes to the trabecular meshwork of living animals

Histological changes of the peripheral zone in small and large prostates and possible clinical implications

Jonathan A Guzman,1 Pranav Sharma,1 Lisa A Smith,1 John D Buie,2 Werner T de Riese1 1Department of Urology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; 2Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, TX, USA Introduction: It is well documented in literature that most prostate carcinomas (PCa) arise in the peripheral zone (PZ). Additionally, an inverse relationship between prostate size and the incidence of PCa has been demonstrated in recent studies. However, little is known about gland distribution in the peripheral zone of larger prostates compared to smaller prostates. In this study, we examined the histo-anatomical gland distribution within the peripheral zone in small and large prostates and discuss possible clinical implications. Methods: A semi-quantitative analysis of gland density and capsule thickness was performed using light microscopy on 10 large (&ge;80 g) prostate specimens and 10 small ( Results: Large prostates possessed a significantly lower mean gland count per field compared to small prostates (10.34&plusmn;4.15, n=50 vs 18.00&plusmn;5.41, n=50; t=8.16, df=49, P&lt;0.001). Additionally, large prostates showed a significantly higher average capsule thickness in millimeters compared to small prostates (1.80 mm, &plusmn;1.12 mm, n=30 vs 0.90 mm, &plusmn;0.56, n=30; t=8.16, df=49, P&lt;0.001). Conclusion: The results demonstrate that prostate hypertrophy leads to both decreased gland density in the peripheral zone and increased capsule thickness, suggesting that growth-induced expansion of the prostate against its capsule leads to compression-induced atrophy and fibrosis of glandular tissue within the peripheral zone (PZ). A decrease in gland density within the PZ may have clinical implications shedding light, for instance, on the reduction in PCa incidence in patients with large prostates as compared to smaller prostates, a phenomenon well documented in the literature. Keywords: prostate, adenocarcinoma, prostatic hyperplasia, peripheral zon

Gastrointestinal Problems in Children with Autism, Developmental Delays or Typical Development

OBJECTIVES: To compare GI problems among children with: 1) autism spectrum disorder (ASD), 2) developmental delay (DD) and 3) typical development (TD). METHODS: In 960 children from the CHildhood Autism Risks from Genetics and the Environment (CHARGE) study, we assessed GI symptom frequency. We examined scores on five Aberrant Behavior Checklist subscales comparing ASD children with high vs. low frequency GI symptoms. RESULTS: Compared to TD children, those with ASD (aOR 7.92[4.89–12.85]) and DD (aOR 4.55 [2.51–8.24]) were more likely to have at least one frequent GI symptom. Restricting to ASD children, those with frequent abdominal pain, gaseousness, diarrhea, constipation or pain on stooling scored worse on Irritability, Social Withdrawal, Stereotypy, and Hyperactivity compared with children having no frequent GI symptoms. CONCLUSIONS: Frequent GI problems affect young children with ASD and DD more commonly than those with TD. Maladaptive behaviors correlate with GI problems, suggesting these comorbidities require attention

FES-rowing attenuates bone loss following spinal cord injury as assessed by HR-pQCT

Neurologically motor complete spinal cord injury (SCI) presents a unique model of bone loss whereby specific regional sites are exposed to a complete loss of voluntary muscle-induced skeletal loading against gravity. This results in a high rate of bone loss, especially in the lower limbs where trabecular bone mass decreases by ~50–60% and cortical bone mass decreases by 25–34% before the rate of bone loss slows. These SCI-induced losses that are likely superimposed on continual age-related bone losses, increase the risk of low-impact fragility fracture. The fracture incidence 20 years post SCI is reported to be 4.6% per year. An intervention that effectively prevents, attenuates, or reverses bone loss is therefore highly desirable. We present a case study of an individual with chronic complete SCI, where bone loss has been attenuated following long-term functional electrical stimulation (FES)-rowing training. In this case study, we characterize the ultradistal tibia and ultradistal radius of the FES-rower with chronic complete SCI using high-resolution-peripheral quantitative computed tomography. These data are compared with a group of FES-untrained individuals with chronic complete SCI and to a normative non-SCI cohort. The evidence suggests, albeit from a single individual, that long-term FES-rowing training can attenuate bone loss secondary to chronic complete SCI. Indeed, key FES-rower’s bone metrics for the ultradistal tibia more closely resemble normative age-matched values, which may have clinical significance since the majority of fragility fractures in chronic SCI occur in the lower extremities