Transplanted neural stem cells survive,differentiate, and improve neurological motor function after experimental traumatic brain injury

OBJECTIVE: Using the neural stem cell (NSC) clone C17.2, we evaluated the ability of transplanted murine NSCs to attenuate cognitive and neurological motor deficits after traumatic brain injury. METHODS: Nonimmunosuppressed C57BL/6 mice (n = 65) were anesthetized and subjected to lateral controlled cortical impact brain injury (n = 52) or surgery without injury (sham operation group, n = 13). At 3 days postinjury, all brain-injured animals were reanesthetized and randomized to receive stereotactic injection of NSCs or control cells (human embryonic kidney cells) into the cortex-hippocampus interface in either the ipsilateral or the contralateral hemisphere. One group of animals (n = 7) was killed at either 1 or 3 weeks postinjury to assess NSC survival in the acute posttraumatic period. Motor function was evaluated at weekly intervals for 12 weeks in the remaining animals, and cognitive (i.e., learning) deficits were assessed at 3 and 12 weeks after transplantation. RESULTS: Brain-injured animals that received either ipsilateral or contralateral NSC transplants showed significantly improved motor function in selected tests as compared with human embryonic kidney cell-transplanted animals during the 12-week observation period. Cognitive dysfunction was unaffected by transplantation at either 3 or 12 weeks postinjury. Histological analyses showed that NSCs survive for as long as 13 weeks after transplantation and were detected in the hippocampus and/or cortical areas adjacent to the injury cavity. At 13 weeks, the NSCs transplanted ipsilateral to the impact site expressed neuronal (NeuN) or astrocytic (glial fibrillary acidic protein) markers but not markers of oligodendrocytes (2'3'cyclic nucleotide 3'-phosphodiesterase), whereas the contralaterally transplanted NSCs expressed neuronal but not glial markers (double-labeled immunofluorescence and confocal microscopy). CONCLUSION: These data suggest that transplanted NSCs can survive in the traumatically injured brain, differentiate into neurons and/or glia, and attenuate motor dysfunction after traumatic brain injury.     

Attentional modulation of SSVEP power depends on the network tagged by the flicker frequency

Modulation of the steady-state visual evoked potential (SSVEP) by attention was studied in detail using 15 'tag' frequencies in the range of 2.5-20 Hz. The stimuli were two series of random disc search arrays superimposed on two concentric color-marked annuli respectively. Two series of arrays were updated independently; one updated at one fixed frequency (flicker) and the other updated randomly according to a white noise distribution (random broadband flicker, rbbf). On each trial, the observer was instructed to attend one annulus and to detect a target (a triangle) that occasionally appeared in a random disc array in the attended annulus. The SSVEP results show that the choice of flicker frequency selects which cortical network synchronizes to the flicker two distinct cortical networks showed different effects of attention. SSVEP power and the effects of attention on SSVEP power strongly depend on both flicker frequency and radial position of rbbf annulus. At flicker frequencies in the delta band (2-4 Hz), and in the upper alpha band (10-11 Hz), an occipital-frontal network appears to phase-lock to the flicker when attending to the flicker, increasing the magnitude of the SSVEP. At flicker frequencies in the lower alpha band (8-10 Hz), a global response to a peripheral flickering stimulus, that includes parietal cortex and posterior frontal cortex, has higher amplitude when attention is directed away from the flickering peripheral stimulus and towards a competing rbbf stimulus in the fovea. Increases in SSVEP power when attention is directed to peripheral flicker are always associated with increases in phase locking. By contrast, at frequencies in the lower alpha band, increases in SSVEP power when attention is directed away from the flicker and towards foveal stimuli are not associated with changes in phase-locking. Thus, whether attention to a flicker stimulus increases or decreases SSVEP amplitude and phase locking depends on which of two cortical networks, which have distinct spatial and dynamic properties, is selected by the flicker frequency.     

End-of-Skin Grafts in Syndactyly Release: Description of a New Flap for Web Space Resurfacing and Primary Closure of Finger Defects

Treatment of syndactyly necessitates creation of neo-web space and separation of fingers. Traditionally, this has been done by use of flaps taken from the dorsum; the resultant raw areas thus created have been managed by use of skin grafts. The classical teaching has been that the separated fingers will need skin graft as primary closure is not possible. The skin grafts have a tendency to contract and lead to finger flexion contractures and “creep” of the web space. We describe a flap based upon subcutaneous tissue in the web that is moved in a V–Y fashion to resurface the neo-web. The flap donor site can easily be closed primarily. The fingers are then separated; the subcutaneous fat is carefully removed from the finger flaps under magnification to allow primary closure of the finger defects. It has been possible to primarily close the donor site and fingers in all the patients. The procedure has been used in seven patients with 14 web releases. The age varied between 10 months to 3 years. The V–Y advancement flap based upon the subcutaneous pedicle in the region of the web allows adequate creation of a new web space. The careful de-fattening of skin flaps allows the separated fingers to be closed primarily.     

Cost-effectiveness Analysis for Technology Acquisition

Background

In a developing country with limited resources, it is important to utilize the total cost visibility approach over the entire life-cycle of the technology and then analyse alternative options for acquiring technology.

Methods

The present study analysed cost-effectiveness of an “In-house” magnetic resonance imaging (MRI) scan facility of a large service hospital against outsourcing possibilities. Cost per unit scan was calculated by operating costing method and break-even volume was calculated. Then life-cycle cost analysis was performed to enable total cost visibility of the MRI scan in both “In-house” and “outsourcing of facility” configuration. Finally, cost-effectiveness analysis was performed to identify the more acceptable decision option.

Result

Total cost for performing unit MRI scan was found to be Rs 3,875 for scans without contrast and Rs 4,129 with contrast. On life-cycle cost analysis, net present value (NPV) of the “In-house” configuration was found to be Rs-(4,09,06,265) while that of “outsourcing of facility” configuration was Rs-(5,70,23,315). Subsequently, cost-effectiveness analysis across eight Figures of Merit showed the “In-house” facility to be the more acceptable option for the system.

Conclusion

Every decision for acquiring high-end technology must be subjected to life-cycle cost analysis.Key Words: Technology assessment, Cost benefit analysis, Cost-effectiveness analysis     

Cost-effectiveness analysis for technology acquisition

Background: In a developing country with limited resources, it is important to utilize the total cost visibility approach over the entire life-cycle of the technology and then analyse alternative options for acquiring technology.     

Giant cell tumour of talus--a case report

Giant cell tumour of the talus bone is rare and is usually seen in skeletally mature adults. Here a case of giant cell tumour of the talus in a skeletally immature boy of 15 years is reported. The patient presented with swelling and tenderness of the left ankle with an osteolytic lesion seen in the talus on x-ray. A trephine biopsy followed by left talar excision was done. Following the biopsy report the patient underwent arthotomy and joint clearance. There was no recurrence noted at six months follow-up.     

Possible role of glial cells in the onset and progression of Lyme neuroborreliosis

Background  

Lyme neuroborreliosis (LNB) may present as meningitis, cranial neuropathy, acute radiculoneuropathy or, rarely, as encephalomyelitis. We hypothesized that glia, upon exposure to Borrelia burgdorferi, the Lyme disease agent, produce inflammatory mediators that promote the acute cellular infiltration of early LNB. This inflammatory context could potentiate glial and neuronal apoptosis.     

Preparation and characterization of Antheraea assama silk fibroin based novel non‐woven scaffold for tissue engineering applications

The quest for novel materials as scaffolds with suitable micro‐architecture for supporting tissue neogenesis in tissue engineering and regenerative medicine (TERM) is continuing. In this paper we report an Antheraea assama silk‐based non‐woven fibroin scaffold for applications in TERM. The novel three‐dimensional scaffold is highly interconnected and porous, with a pore size of 150 µm, porosity of 90% and water uptake capacity of 85%. FTIR revealed a typical β‐sheet structure of fibroin. The scaffold has thermal and mechanical properties superior to those of Bombyx mori, as revealed by DSC, TGA and tensile tests. The scaffold exhibited satisfactory blood compatibility, as determined by thrombogenicity, haemolysis, platelet/leukocyte count, platelet adhesion and protein adsorption studies. The scaffold was found to be cytocompatible with human cell lines A549, KB, HepG2 and HeLa for a period of up to 4 weeks. SEM analysis revealed excellent attachment, spreading and migration of cells in the scaffold. MTT assay was performed to estimate the viability and growth of cells in the matrix. Quantification of collagen in cell–scaffold constructs was done by picro‐Sirius red assay. Ex ovo chorioallantoic membrane assay and nitric oxide estimations in spent culture medium showed the scaffold's ability to promote angiogenesis. Finally, the biodegradability of the scaffold was determined by the weight loss observed upon treatment with trypsin over a period of 4 weeks. The results reveal that the fibroin from A. assama is a promising candidate as a biocompatible, biomimetic and biodegradable biomaterial of natural origin for applications in TERM. Copyright © 2009 John Wiley & Sons, Ltd.