Mitochondrial D-loop sequence variation and maternal lineage in the endangered Cleveland Bay horse

Genetic diversity and maternal ancestry line relationships amongst a sample of 96 Cleveland Bay horses were investigated using a 479bp length of mitochondrial D-loop sequence. The analysis yielded at total of 11 haplotypes with 27 variable positions, all of which have been described in previous equine mitochondrial DNA d-loop studies. Four main haplotype clusters were present in the Cleveland Bay breed describing 89% of the total sample. This suggests that only four principal maternal ancestry lines exist in the present-day global Cleveland Bay population. Comparison of these sequences with other domestic horse haplotypes (Fig 2) shows a close association of the Cleveland Bay horse with Northern European (Clade C), Iberian (Clade A) and North African (Clade B) horse breeds. This indicates that the Cleveland Bay horse may not have evolved exclusively from the now extinct Chapman horse, as previous work as suggested. The Cleveland Bay horse remains one of only five domestic horse breeds classified as Critical on the Rare Breeds Survival Trust (UK) Watchlist and our results provide important information on the origins of this breed and represent a valuable tool for conservation purposes

Policy Coherence in US Tobacco Control: Beyond FDA Regulation

Joshua Yang and Thomas Novotny explore whether the US government can develop and implement a coherent policy agenda to reduce tobacco-related morbidity and mortality

Solid variant of aneurysmal bone cyst of the thoracic spine: a case report

<p>Abstract</p> <p>Introduction</p> <p>The solid variant of aneurysmal bone cyst is rare, and only 13 cases involving the spine have been reported to date, including seven in the thoracic vertebrae. The diagnosis is difficult to secure radiographically before biopsy or surgery.</p> <p>Case report</p> <p>An 18-year-old Hispanic man presented to our facility with a one-year history of left chest pain without any significant neurological deficits. An MRI scan demonstrated a 6 cm diameter enhancing multi-cystic mass centered at the T6 vertebral body with involvement of the left proximal sixth rib and extension into the pleural cavity; the spinal cord was severely compressed with evidence of abnormal T2 signal changes. Our patient was taken to the operating room for a total spondylectomy of T6 with resection of the left sixth rib from a single-stage posterior-only approach. The vertebral column was reconstructed in a 360° manner with an expandable titanium cage and pedicle screw fixation. Histologically, the resected specimen showed predominant solid fibroblastic proliferation, with minor foci of reactive osteoid formation, an area of osteoclastic-like giant cells, and cyst-like areas filled with erythrocytes and focal hemorrhage, consistent with a predominantly solid variant of aneurysmal bone cyst. At 16 months after surgery, our patient remains neurologically intact with resolution of his chest and back pain.</p> <p>Conclusions</p> <p>Because of its rarity, location, and radical treatment approach, we considered this case worthy of reporting. The solid variant of aneurysmal bone cyst is difficult to diagnose radiologically before biopsy or surgery, and we hope to remind other physicians that it should be included in the differential diagnosis of any lytic expansile destructive lesion of the spine.</p

A recurrent mosaic mutation of SMO, encoding the hedgehog signal transducer smoothened, is the major cause of Curry-Jones syndrome

Curry-Jones syndrome (CJS) is a multisystem disorder characterized by patchy skin lesions, polysyndactyly, diverse cerebral malformations, unicoronal craniosynostosis, iris colobomas, microphthalmia, and intestinal malrotation with myofibromas or hamartomas. Cerebellar medulloblastoma has been described in a single affected individual; in another, biopsy of skin lesions showed features of trichoblastoma. The combination of asymmetric clinical features, patchy skin manifestations, and neoplastic association previously led to the suggestion that this could be a mosaic condition, possibly involving hedgehog (Hh) signaling. Here, we show that CJS is caused by recurrent somatic mosaicism for a nonsynonymous variant in SMO (c.1234C&gt;T [p.Leu412Phe]), encoding smoothened (SMO), a G-protein-coupled receptor that transduces Hh signaling. We identified eight mutation-positive individuals (two of whom had not been reported previously) with highly similar phenotypes and demonstrated varying amounts of the mutant allele in different tissues. We present detailed findings from brain MRI in three mutation-positive individuals. Somatic SMO mutations that result in constitutive activation have been described in several tumors, including medulloblastoma, ameloblastoma, and basal cell carcinoma. Strikingly, the most common of these mutations is the identical nonsynonymous variant encoding p.Leu412Phe. Furthermore, this substitution has been shown to activate SMO in the absence of Hh signaling, providing an explanation for tumor development in CJS. This raises therapeutic possibilities for using recently generated Hh-pathway inhibitors. In summary, our work uncovers the major genetic cause of CJS and illustrates strategies for gene discovery in the context of low-level tissue-specific somatic mosaicism

Theory of disk accretion onto supermassive black holes

Accretion onto supermassive black holes produces both the dramatic phenomena associated with active galactic nuclei and the underwhelming displays seen in the Galactic Center and most other nearby galaxies. I review selected aspects of the current theoretical understanding of black hole accretion, emphasizing the role of magnetohydrodynamic turbulence and gravitational instabilities in driving the actual accretion and the importance of the efficacy of cooling in determining the structure and observational appearance of the accretion flow. Ongoing investigations into the dynamics of the plunging region, the origin of variability in the accretion process, and the evolution of warped, twisted, or eccentric disks are summarized.Comment: Mostly introductory review, to appear in "Supermassive black holes in the distant Universe", ed. A.J. Barger, Kluwer Academic Publishers, in pres

Interface of culture, insecurity and HIV and AIDS: Lessons from displaced communities in Pader District, Northern Uganda

<p>Abstract</p> <p>Background</p> <p>Northern Uganda unlike other rural regions has registered high HIV prevalence rates comparable to those of urbanized Kampala and the central region. This could be due to the linkages of culture, insecurity and HIV. We explored community perceptions of HIV and AIDS as a problem and its inter-linkage with culture and insecurity in Pader District.</p> <p>Methods</p> <p>A cross sectional qualitative study was conducted in four sub-counties of Pader District, Uganda between May and June 2008. Data for the study were collected through 12 focus group discussions (FGDs) held separately; 2 FGDs with men, 6 FGDs with women, and 4 FGDs with the youth (2 for each sex). In addition we conducted 15 key informant interviews with; 3 health workers, 4 community leaders at village and parish levels, 3 persons living with HIV and 5 district officials. Data were analysed using the content thematic approach. This process involved identification of the study themes and sub-themes following multiple reading of interview and discussion transcripts. Relevant quotations per thematic area were identified and have been used in the presentation of study findings.</p> <p>Results</p> <p>The struggles to meet the basic and survival needs by individuals and households overshadowed HIV as a major community problem. Conflict and risky sexual related cultural practices were perceived by communities as major drivers of HIV and AIDS in the district. Insecurity had led to congestion in the camps leading to moral decadence, rape and defilement, prostitution and poverty which increased vulnerability to HIV infection. The cultural drivers of HIV and AIDS were; widow inheritance, polygamy, early marriages, family expectations, silence about sex and alcoholism.</p> <p>Conclusions</p> <p>Development partners including civil society organisations, central government, district administration, religious and cultural leaders as well as other stakeholders should mainstream HIV in all community development and livelihood interventions in the post conflict Pader district to curtail the likely escalation of the HIV epidemic. A comprehensive behaviour change communication strategy is urgently needed to address the negative cultural practices. Real progress in the region lies in advocacy and negotiation to realise lasting peace.</p

A Longitudinal Study of Medicaid Coverage for Tobacco Dependence Treatments in Massachusetts and Associated Decreases in Hospitalizations for Cardiovascular Disease

Thomas Land and colleagues show that among Massachusetts Medicaid subscribers, use of a comprehensive tobacco cessation pharmacotherapy benefit was followed by a substantial decrease in claims for hospitalizations for acute myocardial infarction and acute coronary heart disease