Efficient method for site-directed mutagenesis in large plasmids without subcloning.

Commonly used methods for site-directed DNA mutagenesis require copying the entire target plasmid. These methods allow relatively easy modification of DNA sequences in small plasmids but become less efficient and faithful for large plasmids, necessitating full sequence verification. Introduction of mutations in larger plasmids requires subcloning, a slow and labor-intensive process, especially for multiple mutations. We have developed an efficient DNA mutagenesis technique, UnRestricted Mutagenesis and Cloning (URMAC) that replaces subcloning steps with quick biochemical reactions. URMAC does not suffer from plasmid size constraints and allows simultaneous introduction of multiple mutations. URMAC involves manipulation of only the mutagenesis target site(s), not the entire plasmid being mutagenized, therefore only partial sequence verification is required. Basic URMAC requires two PCR reactions, each followed by a ligation reaction to circularize the product, with an optional third enrichment PCR step followed by a traditional cloning step that requires two restriction sites. Here, we demonstrate URMAC's speed, accuracy, and efficiency through several examples, creating insertions, deletions or substitutions in plasmids ranging from 2.6 kb to 17 kb without subcloning.

Strategies to Promote Cultural Competence in Distance Education.

Cultural competence is a mainstay in health care and nursing education. With the expansion in the number of distance-based nursing programs across the country, innovative teaching methods for distance learning faculty are required to instill cultural competence in students. Faculty must be deliberate when planning distance-based learning activities that incorporate cultural experiences. This article describes several such strategies including the creative use of blogging, recorded lectures, the online synchronous classroom, social media, and cultural immersion projects. These methods capitalize on existing information technologies and offer distance-based students the opportunity to connect with one another, as well as develop the awareness, sensitivity, and respect that is required when providing culturally competent care. These teaching methods are modifiable to meet the teaching and learning needs of the faculty and the students, thereby allowing educators to support the integration of cultural competence into patient care for distance students.

Analysis of dystrophin deletion mutations predicts age of cardiomyopathy onset in becker muscular dystrophy.

BACKGROUND: Becker muscular dystrophy (BMD) and X-linked dilated cardiomyopathy often result from deletion mutations in the dystrophin gene that may lead to expression of an altered dystrophin protein in cardiac muscle. Cardiac involvement is present in approximately 70% of BMD and all X-linked dilated cardiomyopathy cases. To date, the timing of cardiomyopathy development remains unpredictable. We analyzed 78 BMD and X-linked dilated cardiomyopathy patients with common deletion mutations predicted to alter the dystrophin protein and correlated their mutations to cardiomyopathy age of onset. This approach was chosen to connect dystrophin structure with function in the heart. METHODS AND RESULTS: Detailed cardiac information was collected for BMD and X-linked dilated cardiomyopathy patients with defined dystrophin gene deletion mutations. Patients were grouped based on the dystrophin protein domain affected by the deletion. Deletions affecting the amino-terminal domain are associated with early-onset dilated cardiomyopathy (DCM; mid-20s), whereas deletions removing part of the rod domain and hinge 3 have a later-onset DCM (mid-40s). Further, we modeled the effects of the most common mutations occurring in the rod domain on the overall structure of the dystrophin protein. By combining genetic and protein information, this analysis revealed a strong correlation between specific protein structural modifications and DCM age of onset. CONCLUSIONS: We identified specific regions of the dystrophin gene that when mutated predispose BMD patients to early-onset DCM. In addition, we propose that some mutations lead to early-onset DCM by specific alterations in protein folding. These findings have potential implications for early intervention in the cardiac care of BMD patients and for therapeutic approaches that target the heart in dystrophinopathies.

AAV as a gene transfer vector for the treatment of neurological disorders: novel treatment thoughts for ALS.

Therapeutic delivery to the central nervous system has challenged scientists and clinicians due to the difficulty in delivering molecules and genes in an efficient manner across the blood brain barrier (BBB). This has particularly hampered efforts to deliver therapeutics to widely dispersed neurons that perish in diseases such as Amyotrophic Lateral Sclerosis (ALS), a disease affecting motor neurons throughout the brainstem and the entire spinal cord. Gene therapy has offered several potential routes to overcome the difficulties in delivering therapeutics to the brain and spinal cord. Adeno-associated viral vectors (AAV) have taken center stage for gene delivery to the central nervous system, given their ability to express genes in post mitotic cells for long periods with minimal to no toxicity. This review will focus on recent approaches to treat motor neuron disease, in particular ALS using AAV vectors.

Current understanding and management of dilated cardiomyopathy in Duchenne and Becker muscular dystrophy.

PURPOSE: To review the current understanding of the pathophysiology of dilated cardiomyopathy (DCM) in patients with Duchenne and Becker muscular dystrophies, assessment of cardiac dysfunction for these patients, and the recommended pharmacological treatment options and ongoing research directions. DATA SOURCES: Reviews and original research articles from scholarly journals and books. CONCLUSIONS: Duchenne and Becker muscular dystrophies are debilitating neuromuscular disorders, both caused by mutations in the dystrophin gene. Most patients develop DCM as part of the disease course; in fact, DCM is the leading cause of death among these patients. Cardiac surveillance, including routine monitoring of electrocardiograms, echocardiograms, and appropriate blood biomarkers, may detect early DCM development. Although previous studies have shown that early administration of cardiac medications may delay the development of DCM, current standard of care does not emphasize cardiac surveillance and timely treatment. This, in turn, limits clinicians, including advanced practice nurses, to be optimally engaged in providing the most aggressive and proactive patient care. IMPLICATIONS FOR PRACTICE: Implementing a routine cardiac assessment and timely pharmacological treatment in primary or specialty care settings is highlighted as an important step to optimize cardiac health among patients with Duchenne and Becker muscular dystrophies.

Gene therapy and informed consent decision making: nursing research directions.

Recent gene therapy clinical trials have demonstrated significant promise for treating a number of genetic neuromuscular disorders. Although nurses are experienced in educating patients and families about the benefits and risks of conventional therapeutics, there are significant challenges for guiding patients through the decision-making phase of gene therapy clinical trial participation. The first part of this review provides an overview and update on neuromuscular gene therapy, including viral delivery principles and historical progress. The second part discusses risk/benefit perception of gene therapy and factors affecting the decision making for patients interested in participating in a trial. Future challenges for gene therapy are targeted high-efficiency delivery, and additional research on developing patient-centered decision support interventions.

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.