In a phase 1/2, open-label dose escalation trial, we delivered rAAVrh74.MCK.GALGT2 (also B4GALNT2) bilaterally to the legs of two boys with Duchenne muscular dystrophy using intravascular limb ...infusion. Subject 1 (age 8.9 years at dosing) received 2.5 × 1013 vector genome (vg)/kg per leg (5 × 1013 vg/kg total) and subject 2 (age 6.9 years at dosing) received 5 × 1013 vg/kg per leg (1 × 1014 vg/kg total). No serious adverse events were observed. Muscle biopsy evaluated 3 or 4 months post treatment versus baseline showed evidence of GALGT2 gene expression and GALGT2-induced muscle cell glycosylation. Functionally, subject 1 showed a decline in 6-min walk test (6MWT) distance; an increase in time to run 100 m, and a decline in North Star Ambulatory Assessment (NSAA) score until ambulation was lost at 24 months. Subject 2, treated at a younger age and at a higher dose, demonstrated an improvement over 24 months in NSAA score (from 20 to 23 points), an increase in 6MWT distance (from 405 to 478 m), and only a minimal increase in 100 m time (45.6–48.4 s). These data suggest preliminary safety at a dose of 1 × 1014 vg/kg and functional stabilization in one patient.
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Results of a first-in-human phase 1/2a clinical trial are reported wherein two patients with Duchenne muscular dystrophy were given GALGT2 gene therapy. The study shows possible stabilization of muscle function in one of two subjects, who was treated with a higher dose and at a younger age.
High energy x-ray diffraction measurements of pure amorphous Ge were made and its radial distribution function (RDF) was determined at high resolution, revealing new information on the atomic ...structure of amorphous semiconductors. Fine structure in the second peak in the RDF provides evidence that a fraction of third neighbors are closer than some second neighbors; taking this into account leads to a narrow distribution of tetrahedral bond angles, (8.5 ± 0.1)°. A small peak which appears near 5 Å upon thermal annealing shows that some ordering in the dihedral bond-angle distribution takes place during structural relaxation. Extended range order is detected (in both a-Ge and a-Si) which persists to beyond 20 Å, and both the periodicity and its decay length increase upon thermal annealing. Previously, the effect of structural relaxation was only detected at intermediate range, involving reduced tetrahedral bond-angle distortions. These results enhance our understanding of the atomic order in continuous random networks and place significantly more stringent requirements on computer models intending to describe these networks, or their alternatives which attempt to describe the structure in terms of an arrangement of paracrystals.
Adults with Down syndrome (DS) represent a unique population who are in need of clinical guidelines to address their medical care. The United States Preventive Service Task Force (USPSTF) has ...developed criteria for prioritizing conditions of public health importance with the potential for providing screening recommendations to improve clinical care. The quality of existing evidence needed to inform clinical guidelines has not been previously reviewed. Using the National Library of Medicine (NLM) database PubMed, we first identified 18 peer reviewed articles that addressed co‐occurring medical conditions in adults with DS. Those conditions discussed in over half of the articles were prioritized for further review. Second, we performed detailed literature searches on these specific conditions. To inform the search strategy and review process a series of key questions were formulated a priori. The quality of available evidence was then graded and knowledge gaps were identified. The number of participating adults and the design of clinical studies varied by condition and were often inadequate for answering all of our key questions. We provide data on thyroid disease, cervical spine disease, hearing impairment, overweight‐obesity, sleep apnea, congenital heart disease, and osteopenia‐osteoporosis. Minimal evidence demonstrates massive gaps in our clinical knowledge that compromises clinical decision‐making and management of these medically complex individuals. The development of evidence‐based clinical guidance will require an expanded clinical knowledge‐base in order to move forward.
Overexpression of GALGT2 in skeletal muscle can stimulate the glycosylation of alpha dystroglycan and the upregulation of normally synaptic dystroglycan-binding proteins, some of which are dystrophin ...and laminin alpha 2 surrogates known to be therapeutic for several forms of muscular dystrophy. This article describes the vascular delivery of GALGT2 gene therapy in a large animal model, the rhesus macaque. Recombinant adeno-associated virus, rhesus serotype 74 (rAAVrh74), was used to deliver GALGT2 via the femoral artery to the gastrocnemius muscle using an isolated focal limb perfusion method. GALGT2 expression averaged 44 + or - 4% of myofibers after treatment in macaques with low preexisting anti-rAAVrh74 serum antibodies, and expression was reduced to 9 + or - 4% of myofibers in macaques with high preexisting rAAVrh74 immunity (P < 0.001; n = 12 per group). This was the case regardless of the addition of immunosuppressants, including prednisolone, tacrolimus, and mycophenolate mofetil. GALGT2-treated macaque muscles showed increased glycosylation of alpha dystroglycan and increased expression of dystrophin and laminin alpha 2 surrogate proteins, including utrophin, plectin1, agrin, and laminin alpha 5. These experiments demonstrate successful transduction of rhesus macaque muscle with rAAVrhy4.MCK.GALGT2 after vascular delivery and induction of molecular changes thought to be therapeutic in several forms of muscular dystrophy.
The natural history of chronic hepatitis B in children is influenced by mode of transmission and varies with regional endemicity. Seroconversion rates were studied in 174 hepatitis B e antigen ...(HBeAg)–positive children who were of different ethnic origins and living in Canada. Overall, 40.2% became anti-HBeAg positive, and 8.6% were hepatitis B surface-antigen positive during a mean follow-up of 4.5 years. Spontaneous seroconversion rates were lower in Asian-born, mainly vertically infected, children, versus those born either in Canada or where horizontal transmission predominates (24% vs. 44%, P=.015). Kaplan-Meier analysis showed that the cumulative persistence of HBeAg after 13 years was 25% in Asian-born children, versus 6% in all others (P<.05). Treatment of 27 children accelerated seroconversion by 3 years, without influencing the proportion seroconverting over time. Thus, although Asian-born children seroconvert more slowly, a large proportion will seroconvert before adulthood. Because treatment appears to accelerate anti-HBe seroconversion, longitudinal studies are required in order to assess the long-term benefits of early treatment
Loss of functional RAB18 causes the autosomal recessive condition Warburg Micro syndrome. To better understand this disease, we used proximity biotinylation to generate an inventory of potential ...RAB18 effectors. A restricted set of 28 RAB18-interactions were dependent on the binary RAB3GAP1-RAB3GAP2 RAB18-guanine nucleotide exchange factor (GEF) complex. 12 of these 28 interactions are supported by prior reports and we have directly validated novel interactions with SEC22A, TMCO4 and INPP5B. Consistent with a role for RAB18 in regulating membrane contact sites (MCSs), interactors included groups of microtubule/membrane-remodelling proteins, membrane-tethering and docking proteins, and lipid-modifying/transporting proteins. Two of the putative interactors, EBP and OSBPL2/ORP2, have sterol substrates. EBP is a Δ8-Δ7 sterol isomerase and ORP2 is a lipid transport protein. This prompted us to investigate a role for RAB18 in cholesterol biosynthesis. We find that the cholesterol precursor and EBP-product lathosterol accumulates in both RAB18-null HeLa cells and RAB3GAP1-null fibroblasts derived from an affected individual. Further, de novo cholesterol biosynthesis is impaired in cells in which RAB18 is absent or dysregulated, or in which ORP2 expression is disrupted. Our data demonstrate that GEF-dependent Rab-interactions are highly amenable to interrogation by proximity biotinylation and may suggest that Micro syndrome is a cholesterol biosynthesis disorder.
The cytotoxic T cell (CT) GalNAc transferase, or Galgt2, is a UDP-GalNAc:beta1,4-N-acetylgalactosaminyltransferase that is localized to the neuromuscular synapse in adult skeletal muscle, where it ...creates the synaptic CT carbohydrate antigen {GalNAcbeta1,4NeuAc(orGc)alpha2, 3Galbeta1,4GlcNAcbeta-}. Overexpression of Galgt2 in the skeletal muscles of transgenic mice inhibits the development of muscular dystrophy in mdx mice, a model for Duchenne muscular dystrophy. Here, we provide physiological evidence as to how Galgt2 may inhibit the development of muscle pathology in mdx animals. Both Galgt2 transgenic wild-type and mdx skeletal muscles showed a marked improvement in normalized isometric force during repetitive eccentric contractions relative to nontransgenic littermates, even using a paradigm where nontransgenic muscles had force reductions of 95% or more. Muscles from Galgt2 transgenic mice, however, showed a significant decrement in normalized specific force and in hindlimb and forelimb grip strength at some ages. Overexpression of Galgt2 in muscles of young adult mdx mice, where Galgt2 has no effect on muscle size, also caused a significant decrease in force drop during eccentric contractions and increased normalized specific force. A comparison of Galgt2 and microdystrophin overexpression using a therapeutically relevant intravascular gene delivery protocol showed Galgt2 was as effective as microdystrophin at preventing loss of force during eccentric contractions. These experiments provide a mechanism to explain why Galgt2 overexpression inhibits muscular dystrophy in mdx muscles. That overexpression also prevents loss of force in nondystrophic muscles suggests that Galgt2 is a therapeutic target with broad potential applications.
Recombinant adeno-associated virus (rAAV)rh74.MCK.GALGT2 is a muscle-specific gene therapy that is being developed to treat forms of muscular dystrophy. Here we report on an isolated limb infusion ...technique in a non-human primate model, where hindlimb blood flow is transiently isolated using balloon catheters to concentrate vector in targeted leg muscles. A bilateral dose of 2.5 × 1013 vector genomes (vg)/kg/limb was sufficient to induce GALGT2-induced glycosylation in 10%–60% of skeletal myofibers in all leg muscles examined. There was a 19-fold ± 6-fold average limb-wide increase in vector genomes per microgram genomic DNA at a bilateral dose of 2.5 × 1013 vg/kg/limb compared with a bilateral dose of 6 × 1012 vg/kg/limb. A unilateral dose of 6 × 1013 vg/kg/limb showed a 12- ± 3-fold increase in treated limb muscles compared to contralateral untreated limb muscles, which received vector only after release into the systemic circulation from the treated limb. Variability in AAV biodistribution between different segments of the same muscle was 125% ± 18% for any given dose, while variability between the same muscle for any given treatment dose was 45% ± 7%. These experiments demonstrate that treatment of muscles throughout the leg with rAAVrh74.MCK.GALGT2 can be accomplished safely using an isolated limb infusion technique, where balloon catheters transiently isolate the limb vasculature, but that intra- and inter-muscle transduction variability is a significant issue.
ABSTRACT
Background
Women with Down syndrome have a lower breast cancer risk and significantly lower life expectancies than women without Down syndrome. Therefore, it is not clear whether mammography ...screening strategies used for women without Down syndrome would benefit women with Down syndrome in the same way.
Objective
To determine the benefits and harms of various mammography screening strategies for women with Down syndrome using collaborative simulation modeling.
Design
Two established Cancer Intervention and Surveillance Modeling Network (CISNET) simulation models estimated the benefits and harms of various screening strategies for women with Down syndrome over a lifetime horizon.
Participants
We modeled a hypothetical cohort of US women with Down syndrome who were born in 1970.
Interventions
Annual, biennial, triennial, and one-time digital mammography screenings during the ages 40–74.
Main Measures
The models estimated numbers of mammograms, false-positives, benign biopsies, breast cancer deaths prevented, and life-years gained per 1000 screened women when compared with no screening.
Key Results
In average-risk women 50–74, biennial screening incurred 122 mammograms, 10 false-positive mammograms, and 1.4 benign biopsies per one life-year gained compared with no screening. In women with Down syndrome, the same screening strategy incurred 2752 mammograms, 242 false-positive mammograms, and 34 benign biopsies per one life-year gained compared with no screening. The harm/benefit ratio varied for other screening strategies, and was most favorable for one-time screening at age 50, which incurred 1629 mammograms, 144 false-positive mammograms, and 20 benign biopsies per one life-year gained compared with no screening.
Conclusions
The harm/benefit ratios for various mammography screening strategies in women with Down syndrome are not as favorable as those for average-risk women. The benefit of screening mammography for women with Down syndrome is less pronounced due to lower breast cancer risk and shorter life expectancy.
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