Tailoring the carbon nanostructures grown on the surface of Ni-Al bimetallic nanoparticles in the gas phase.

A gas-phase, one-step method for producing various aerosol carbon nanostructures is described. The carbon nanostructures can be selectively tailored with either straight, coiled, or sea urchin-like structures by controlling the size of Ni-Al bimetallic nanoparticles and the reaction temperature. The carbon nanostructures were grown using both conventional spray pyrolysis and thermal chemical vapor deposition. Bimetallic nanoparticles with catalytic Ni (guest) and non-catalytic Al (host) matrix were reacted with acetylene and hydrogen gases. At the processing temperature range of 650-800 °C, high concentration straight carbon nanotubes (S-CNTs) with a small amount of coiled carbon nanotubes (C-CNTs) can be grown on the surface of seeded bimetallic nanoparticle size <100 nm, resulting from consumption of the melting Al matrix sites; sea urchin-like carbon nanotubes (SU-CNTs) of small diameter (∼10±4 nm) can be grown on the bimetallic nanoparticle size >100 nm, resulting from the significant size reduction of the available Ni sites due to thermal expansion of molten Al matrix sites without consumption of Al matrix. However, at the processing temperature range of 500-650 °C, C-CNTs can be grown on the bimetallic nanoparticle size <100 nm due to the presence of Al matrix in the bimetallic nanoparticles; SU-CNTs of large diameter (∼60±13 nm) can also be grown on the bimetallic nanoparticle size >100 nm due to the isolation of Ni sites in the Al matrix.

Delivery of AAV-IGF-1 to the CNS extends survival in ALS mice through modification of aberrant glial cell activity.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of the motor system. Recent work in rodent models of ALS has shown that insulin-like growth factor-1 (IGF-1) slows disease progression when delivered at disease onset. However, IGF-1's mechanism of action along the neuromuscular axis remains unclear. In this study, symptomatic ALS mice received IGF-1 through stereotaxic injection of an IGF-1-expressing viral vector to the deep cerebellar nuclei (DCN), a region of the cerebellum with extensive brain stem and spinal cord connections. We found that delivery of IGF-1 to the central nervous system (CNS) reduced ALS neuropathology, improved muscle strength, and significantly extended life span in ALS mice. To explore the mechanism of action of IGF-1, we used a newly developed in vitro model of ALS. We demonstrate that IGF-1 is potently neuroprotective and attenuates glial cell-mediated release of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO). Our results show that delivering IGF-1 to the CNS is sufficient to delay disease progression in a mouse model of familial ALS and demonstrate for the first time that IGF-1 attenuates the pathological activity of non-neuronal cells that contribute to disease progression. Our findings highlight an innovative approach for delivering IGF-1 to the CNS.

Gene transfer demonstrates that muscle is not a primary target for non-cell-autonomous toxicity in familial amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal, progressive paralysis arising from the premature death of motor neurons. An inherited form is caused by a dominant mutation in the ubiquitously expressed superoxide dismutase (SOD1). SOD1 mutant expression within motor neurons is a determinant of onset and early disease, and mutant accumulation within microglia accelerates disease progression. Muscle also is a likely primary source for toxicity, because retraction of motor axons from synaptic connections to muscle is among the earliest presymptomatic events. To test involvement of muscle in ALS, viral delivery of transcription-mediated siRNA is shown to suppress mutant SOD1 accumulation within muscle alone but to be insufficient to maintain grip strength, whereas delivery to both motor neurons and muscle is sufficient. Use of a deletable mutant gene to diminish mutant SOD1 from muscle did not affect onset or survival. Finally, follistatin expression encoded by adeno-associated virus chronically inhibited myostatin and produced sustained increases in muscle mass, myofiber number, and fiber diameter, but these increases did not affect survival. Thus, SOD1-mutant-mediated damage within muscles is not a significant contributor to non-cell-autonomous pathogenesis in ALS, and enhancing muscle mass and strength provides no benefit in slowing disease onset or progression.

Percutaneous laryngeal collagen augmentation for treatment of parkinsonian hypophonia.

OBJECTIVE: Our goal was to determine whether percutaneous laryngeal collagen augmentation improves hypophonia in parkinsonian patients. STUDY DESIGN AND SETTING: A retrospective review of 18 patients was performed. Patients and/or caretakers were called on the telephone and asked about their response to the procedure, if any. Videostroboscopic examinations for all patients were reviewed. RESULTS: Of 18 patients, 11 (61%) reported improvement in their hypophonia for a period of at least 2 months. Five of 7 patients without improvement were relatively aphonic both before and after the procedure. Five of 7 patients without improvement had severe dysphagia, which in 3 necessitated gastrostomy tube placement. Four of 7 patients without improvement were not ambulatory at the time of the procedure. CONCLUSIONS: Percutaneous laryngeal collagen augmentation is an effective treatment for parkinsonian hypophonia in a majority of patients. Patients with advanced neurologic disease with aphonia, difficulty with speech initiation, dysphagia, or ambulatory difficulty are less likely to respond to this procedure and should be so informed.