West Nile virus preferentially transports along motor neuron axons after sciatic nerve injection of hamsters

Prior findings led us to hypothesize that West Nile virus (WNV) preferentially transports along motor axons instead of sensory axons. WNV is known to undergo axonal transport in cell culture and in infected hamsters to infect motor neurons in the spinal cord. To investigate this hypothesis, WNV was injected directly into the left sciatic nerve of hamsters. WNV envelope-staining in these hamsters was only observed in motor neurons of the ipsilateral ventral horn of the spinal cord, but not in the dorsal root ganglion (DRG). To evaluate the consequence of motor neuron infection by WNV, the authors inoculated wheat germ agglutinin—horseradish peroxidase (WGA-HRP) 9 days after WNV sciatic nerve injection, and stained the spinal cord and the DRG for HRP activity 3 days later. The degree of HRP-staining in DRG was the same in WNV- and sham-infected animals, but the HRP-staining in the motor neuron in the ventral horn was considerably less for WNV-infected hamsters. To investigate the mechanism of WNV transport, hamsters were treated with colchicine, an inhibitor of membranous microtubule-mediated transport. The intensity of the WNV-stained area in the spinal cord of colchicine-treated hamsters at 6 days after WNV infection were significantly reduced (P≤.05) compared to the placebo-treated hamsters. These data suggest that WNV is preferentially transported through the motor axons, but not the sensory axons, to subsequently infect motor neurons and cause motor weakness and paralysis.     

The impact of ownership on health care services in HMOs

Tests the theory that owners (hospital, physician, insurance) of vertically integrated health maintenance organizations (HMOs) might substitute towards production of their own specialty goods. Uses data from various sources in the USA. Determines the impact of ownership on factors such as average physician ambulatory services per enrollee and average hospital days per enrollee. Concludes that policymakers need to encourage the development of standard publicly available quality measures to intensify competition and eliminate excess profits accruing to provider-owners who substitute towards production of their own goods.     

Safety & efficacy of single subconjunctival triamcinolone 5 mg depot vs topical loteprednol post cataract surgery: less drop cataract surgery

AIM: To do a randomized prospective interventional study for comparing the effects of a single subconjunctival triamcinolone acetonide (SCTA) injection to tapering topical loteprednol in patients undergoing phacoemulsification surgery under topical anesthesia. METHODS: A total of 400 patients were randomized into 2 groups; Group A (200 patients) received 5 mg SCTA at the end of surgery and topical ketorolac tromethamine (0.5%) with ofloxacin (0.3%) combination for 3wk. Group B (200 patients) received tapering topical loteprednol etabonate (0.5%) along with ofloxacin (0.3%) and ketorolac tromethamine (0.5%) for 3wk. Outcomes evaluated were intraocular pressure (IOP), anterior chamber cells/flare and macular oedema postoperatively at 1, 6 and 12wk. RESULTS: Baseline parameters were almost similar in both the groups. No statistical difference was seen between the preoperative and postoperative IOP values for Group A (P=0.82) and Group B (P=0.61) and postoperative IOP values in between both groups (P=0.14) at 1wk. Incidence of cells/flare postoperative was statistically not significant (P=0.82) in both groups at all follow up visits. Postoperative macular oedema was not observed at any follow up visit. CONCLUSION: SCTA appears to be an effective alternative to prolong postoperative topical steroid use.     

Mutant C9orf72 human iPSC-derived astrocytes cause non-cell autonomous motor neuron pathophysiology

Mutations in C9orf72 are the most common genetic cause of amyotrophic lateral sclerosis (ALS). Accumulating evidence implicates astrocytes as important non-cell autonomous contributors to ALS pathogenesis, although the potential deleterious effects of astrocytes on the function of motor neurons remains to be determined in a completely humanized model of C9orf72-mediated ALS. Here, we use a human iPSC-based model to study the cell autonomous and non-autonomous consequences of mutant C9orf72 expression by astrocytes. We show that mutant astrocytes both recapitulate key aspects of C9orf72-related ALS pathology and, upon co-culture, cause motor neurons to undergo a progressive loss of action potential output due to decreases in the magnitude of voltage-activated Na⁺ and K⁺ currents. Importantly, CRISPR/Cas-9 mediated excision of the C9orf72 repeat expansion reverses these phenotypes, confirming that the C9orf72 mutation is responsible for both cell-autonomous astrocyte pathology and non-cell autonomous motor neuron pathophysiology.     

A scaleable and defined system for generating neural stem cells from human embryonic stem cells

The ability to differentiate human ESCs (hESCs) to defined lineages in a totally controlled manner is fundamental to developing cell-based therapies and studying human developmental mechanisms. We report a novel, scaleable, and widely applicable system for deriving and propagating neural stem cells from hESCs without the use of animal products, proprietary formulations, or genetic manipulation. This system provides a definitive platform for studying human neural development and has potential therapeutic implications.     

Multiple sclerosis: correlation of magnetic resonance imaging with cerebrospinal fluid findings.

MRI examination of 41 patients with clinical definite multiple sclerosis showed white matter lesions of high proton T2 signal consistent with demyelination in 76% and CSF abnormalities present in 76%. Of patients with CSF abnormalities, 26% had normal MRI scans; conversely 26% of patients with MRI abnormalities had negative CSF studies. Thus a significant number of multiple sclerosis patients had negative results on either MRI or CSF examination, while only 5% had normal results on both tests.     

Automated mechanical passaging: a novel and efficient method for human embryonic stem cell expansion

There is a need for more standardized methods of maintenance and propagation of human embryonic stem cell (hESC) cultures. Enzymatic passaging currently represents the most widely used method for expansion of hESCs. Although rapid and straightforward, this technique results in variable-sized cell clusters and significant cellular trauma, which may apply selective pressure in long-term culture. Mechanical passaging has the potential advantages of defined colony fragment sizes, reduced cellular trauma, and the possibility of selecting undifferentiated colonies for transfer. However, manual dissection of individual colonies is a prohibitively time-consuming process unsuitable for maintaining large numbers of hESCs without the use of additional chemical means. In this study we report an efficient automated method for mechanically passaging hESCs. We have used this method exclusively to maintain hESCs in long-term undifferentiated culture without the use of enzymatic digestion for longer than 100 days. This automated technique can thus be used routinely to culture hESCs in the laboratory.     

Development and evaluation of a multifaceted ergonomics program to prevent injuries associated with patient handling tasks

PROBLEM STATEMENT: Nurses have one of the highest rates of work-related musculoskeletal injury of any profession. Over the past 30 years, efforts to reduce work-related musculoskeletal disorders in nurses have been largely unsuccessful. SPECIFIC AIMS: The primary goal of this program was to create safer working environments for nursing staff who provide direct patient care. Our first objective was to design and implement a multifaceted program that successfully integrated evidence-based practice, technology, and safety improvement. The second objective was to evaluate the impact of the program on injury rate, lost and modified work days, job satisfaction, self-reported unsafe patient handling acts, level of support for program, staff and patient acceptance, program effectiveness, costs, and return on investment. INTERVENTION: The intervention included six program elements: (1) Ergonomic Assessment Protocol, (2) Patient Handling Assessment Criteria and Decision Algorithms, (3) Peer Leader role, "Back Injury Resource Nurses", (4) State-of-the-art Equipment, (5) After Action Reviews, and (6) No Lift Policy. METHODS: A pre-/post design without a control group was used to evaluate the effectiveness of a patient care ergonomics program on 23 high risk units (19 nursing home care units and 4 spinal cord injury units) in 7 facilities. Injury rates, lost work days, modified work days, job satisfaction, staff , and patient acceptance, program effectiveness, and program costs/savings were compared over two nine month periods: pre-intervention (May 2001-January 2002) and post-intervention (March 2002-November 2002). Data were collected prospectively through surveys, weekly process logs, injury logs, and cost logs. RESULTS: The program elements resulted in a statistically significant decrease in the rate of musculoskeletal injuries as well as the number of modified duty days taken per injury. While the total number of lost workdays decreased by 18% post-intervention, this difference was not statistically significant. There were statistically significant increases in two subscales of job satisfaction: professional status and tasks requirements. Self-reports by nursing staff revealed a statistically significant decrease in the number of 'unsafe' patient handling practices performed daily. Nurses ranked program elements they deemed to be "extremely effective": equipment was rated as most effective (96%), followed by No Lift Policy (68%), peer leader education program (66%), ergonomic assessment protocol (59%), patient handling assessment criteria and decision algorithms (55%), and lastly after action reviews (41%). Perceived support and interest for the program started at a high level for managers and nursing staff and remained very high throughout the program implementation. Patient acceptance was moderate when the program started but increased to very high by the end of the program. Although the ease and success of program implementation initially varied between and within the facilities, after six months there was strong evidence of support at all levels. The initial capital investment for patient handling equipment was recovered in approximately 3.75 years based on annual post-intervention savings of over $200,000/year in workers' compensation expenses and cost savings associated with reduced lost and modified work days and worker compensation. CONCLUSIONS: This multi-faceted program resulted in an overall lower injury rate, fewer modified duty days taken per injury, and significant cost savings. The program was well accepted by patients, nursing staff, and administrators. Given the significant increases in two job satisfaction subscales (professional status and task requirements), it is possible that nurse recruitment and retention could be positively impacted.     

A highly enriched niche of precursor cells with neuronal and glial potential within the hair follicle dermal papilla of adult skin

Skin-derived precursor cells (SKPs) are multipotent neural crest-related stem cells that grow as self-renewing spheres and are capable of generating neurons and myelinating glial cells. SKPs are of clinical interest because they are accessible and potentially autologous. However, although spheres can be readily isolated from embryonic and neonatal skin, SKP frequency falls away sharply in adulthood, and primary sphere generation from adult human skin is more problematic. In addition, the culture-initiating cell population is undefined and heterogeneous, limiting experimental studies addressing important aspects of these cells such as the behavior of endogenous precursors in vivo and the molecular mechanisms of neural generation. Using a combined fate-mapping and microdissection approach, we identified and characterized a highly enriched niche of neural crest-derived sphere-forming cells within the dermal papilla of the hair follicle of adult skin. We demonstrated that the dermal papilla of the rodent vibrissal follicle is 1,000-fold enriched for sphere-forming neural crest-derived cells compared with whole facial skin. These "papillaspheres" share a phenotypic and developmental profile similar to that of SKPs, can be readily expanded in vitro, and are able to generate both neuronal and glial cells in response to appropriate cues. We demonstrate that papillaspheres can be efficiently generated and expanded from adult human facial skin by microdissection of a single hair follicle. This strategy of targeting a highly enriched niche of sphere-forming cells provides a novel and efficient method for generating neuronal and glial cells from an accessible adult somatic source that is both defined and minimally invasive.