Neuroanatomy- and Pathology-Based Functional Examinations of Experimental Stroke in Rats: Development and Validation of a New Behavioral Scoring System

In experimental stroke studies, a neuroanatomy-based functional examination of behaviors is critical to predict the pathological extent of infarcts because brain-imaging studies are not always available. However, there is a lack of systematic studies to examine the efficiency of a behavioral test for this purpose. Our work aimed to design a new score for this goal in stroke rats, by simplifying the Garcia score (with subscore 1–6) and adding circling as subscore 7. MRI and 2,3,5-triphenyltetrazolium chloride staining were used to determine the pathological extent after transient middle cerebral artery occlusion. The modified summations of subscores were designed according to the predictability of each subscore for locations and sizes of infarcts in one group of stroke rats, and were validated in another group. The original Garcia score was able to predict the pathological extent of edema-adjusted infarct size ≥30%, and the summation of subscore 4, 6, and 7 (4: climbing, 6: vibrissae sensation, 7: circling) also could predict it well. The original Garcia score failed to predict infarct at the primary motor cortex, while the summation of subscore 4, 6, and 7 potentially could predict not only the primary motor cortex, but also the forelimb, hindlimb, and barrel field regions of the primary sensory cortex. Accordingly, this neuroanatomy-correlated functional assessment system composed of subscore 4, 6, and 7 was proposed, with less examination time and better inter-rater reliability than the original Garcia score. In summary, this new scoring system, summation (4,6,7) score, examined motor and sensory functions based on neuroanatomical involvement, having the potential to predict the pathological extent and specific relevant brain areas of infarcts, respectively

Pathophysiology of Neuropathic Pain in Type 2 Diabetes: Skin denervation and contact heat–evoked potentials

OBJECTIVE: Neuropathic pain due to small-fiber sensory neuropathy in type 2 diabetes can be diagnosed by skin biopsy with quantification of intra- epidermal nerve fiber ( IENF) density. There is, however, a lack of noninvasive physiological assessment. Contact heat-evoked potential ( CHEP ) is a newly developed approach to record cerebral responses of A fiber- mediated thermonociceptive stimuli. We investigated the diagnostic role of CHEP. RESEARCH DESIGN AND METHODS: From 2006 to 2009, there were 32 type 2 diabetic patients (20 males and 12 females, aged 51.63 10.93 years) with skin denervation and neuropathic pain. CHEPs were recorded with heat stimulations at the distal leg, where skin biopsy was performed. RESULTS: CHEP amplitude was reduced in patients compared with age- and sex-matched control subjects (14.8 15.6 vs. 33.7 10.1 V, P < 0.001). Abnormal CHEP patterns ( reduced amplitude or prolonged latency) were noted in 81.3 % of these patients. The CHEP amplitude was the most significant parameter correlated with IENF density (P = 0. 003) and pain perception to contact heat stimuli (P = 0.019) on multiple linear regression models. An excitability index was derived by calculating the ratio of the CHEP amplitude over the IENF density. This excitability index was higher in diabetic patients than in control subjects (P = 0.023), indicating enhanced brain activities in neuropathic pain. Among different neuropathic pain symptoms, the subgroup with evoked pain had higher CHEP amplitudes than the subgroup without evoked pain (P = 0.011). CONCLUSIONS: CHEP offers a noninvasive approach to evaluate the degeneration of thermonociceptive nerves in diabetic neuropathy by providing physiological correlates of skin denervation and neuropathic pain

Effective gene expression in the rat dorsal root ganglia with a non-viral vector delivered via spinal nerve injection

Delivering gene constructs into the dorsal root ganglia (DRG) is a powerful but challenging therapeutic strategy for sensory disorders affecting the DRG and their peripheral processes. The current delivery methods of direct intra-DRG injection and intrathecal injection have several disadvantages, including potential injury to DRG neurons and low transfection efficiency, respectively. This study aimed to develop a spinal nerve injection strategy to deliver polyethylenimine mixed with plasmid (PEI/DNA polyplexes) containing green fluorescent protein (GFP). Using this spinal nerve injection approach, PEI/DNA polyplexes were delivered to DRG neurons without nerve injury. Within one week of the delivery, GFP expression was detected in 82.8% ± 1.70% of DRG neurons, comparable to the levels obtained by intra-DRG injection (81.3% ± 5.1%, p = 0.82) but much higher than those obtained by intrathecal injection. The degree of GFP expression by neurofilament(+) and peripherin(+) DRG neurons was similar. The safety of this approach was documented by the absence of injury marker expression, including activation transcription factor 3 and ionized calcium binding adaptor molecule 1 for neurons and glia, respectively, as well as the absence of behavioral changes. These results demonstrated the efficacy and safety of delivering PEI/DNA polyplexes to DRG neurons via spinal nerve injection.National Science Council of Taiwan (100-2321-B-002-007)National Science Council of Taiwan (100-2320-B-002-083-MY3)Taiwan. Ministry of Science and Technology (104-2300-B-002-019-MY3)National Taiwan University. College of Medicine (Translational Medicine Project)National Taiwan University Hospital (101C101-201

Role of acid-sensing ion channel 3 in sub-acute-phase inflammation

<p>Abstract</p> <p>Background</p> <p>Inflammation-mediated hyperalgesia involves tissue acidosis and sensitization of nociceptors. Many studies have reported increased expression of acid-sensing ion channel 3 (ASIC3) in inflammation and enhanced ASIC3 channel activity with pro-inflammatory mediators. However, the role of ASIC3 in inflammation remains inconclusive because of conflicting results generated from studies of <it>ASIC3 </it>knockout (<it>ASIC3</it>^-/-) or dominant-negative mutant mice, which have shown normal, decreased or increased hyperalgesia during inflammation.</p> <p>Results</p> <p>Here, we tested whether ASIC3 plays an important role in inflammation of subcutaneous tissue of paw and muscle in <it>ASIC3</it>^-/-mice induced by complete Freund's adjuvant (CFA) or carrageenan by investigating behavioral and pathological responses, as well as the expression profile of ion channels. Compared with the <it>ASIC3</it>^+/+controls, <it>ASIC3</it>^-/-mice showed normal thermal and mechanical hyperalgesia with acute (4-h) intraplantar CFA- or carrageenan-induced inflammation, but the hyperalgesic effects in the sub-acute phase (1–2 days) were milder in all paradigms except for thermal hyperalgesia with CFA-induced inflammation. Interestingly, carrageenan-induced primary hyperalgesia was accompanied by an <it>ASIC3</it>-dependent <it>Nav1.9 </it>up-regulation and increase of tetrodotoxin (TTX)-resistant sodium currents. CFA-inflamed muscle did not evoke hyperalgesia in <it>ASIC3</it>^-/-or <it>ASIC3</it>^+/+mice, whereas carrageenan-induced inflammation in muscle abolished mechanical hyperalgesia in <it>ASIC3</it>^-/-mice, as previously described. However, <it>ASIC3</it>^-/-mice showed attenuated pathological features such as less CFA-induced granulomas and milder carrageenan-evoked vasculitis as compared with <it>ASIC3</it>^+/+mice.</p> <p>Conclusion</p> <p>We provide a novel finding that ASIC3 participates in the maintenance of sub-acute-phase primary hyperalgesia in subcutaneous inflammation and mediates the process of granuloma formation and vasculitis in intramuscular inflammation.</p

Mobile-cloud assisted video summarization framework for efficient management of remote sensing data generated by wireless capsule sensors

YesWireless capsule endoscopy (WCE) has great advantages over traditional endoscopy because it is portable and easy to use, especially in remote monitoring health-services. However, during the WCE process, the large amount of captured video data demands a significant deal of computation to analyze and retrieve informative video frames. In order to facilitate efficient WCE data collection and browsing task, we present a resource- and bandwidth-aware WCE video summarization framework that extracts the representative keyframes of the WCE video contents by removing redundant and non-informative frames. For redundancy elimination, we use Jeffrey-divergence between color histograms and inter-frame Boolean series-based correlation of color channels. To remove non-informative frames, multi-fractal texture features are extracted to assist the classification using an ensemble-based classifier. Owing to the limited WCE resources, it is impossible for the WCE system to perform computationally intensive video summarization tasks. To resolve computational challenges, mobile-cloud architecture is incorporated, which provides resizable computing capacities by adaptively offloading video summarization tasks between the client and the cloud server. The qualitative and quantitative results are encouraging and show that the proposed framework saves information transmission cost and bandwidth, as well as the valuable time of data analysts in browsing remote sensing data.Supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2013R1A1A2012904)

Modulation of Keratinocyte Proliferation by Skin Innervation

Several lines of evidence suggest that sensory nerves ending at the skin have profound influences on their target, the epidermis. To test the hypothesis, we examined the consequences of denervation on the paw skin of rats by eliminating its innervation. We investigated temporal changes of nerve degeneration, keratinocyte proliferation and differentiation, gene expression, and epidermal thickness. Nerve terminals in the epidermis began to degenerate within 24 h after denervation. All epidermal nerves were completely degenerated by 2 d. During the interval of nerve degeneration, there was a significant reduction of bromodeoxyuridine incorporation from 24 h of nerve injury (39 +/- 7% of the control side, p 0.01). By 2 d, there was a further reduction of bromodeoxyuridine labeling (11 +/- 8%, p < 0. 0001). The incorporation of bromodeoxyuridine remained depressed when the skin was denervated (35 +/- 11%, p < 0.01). Four days after eliminating skin innervation, the denervated epidermis became thinner than the control epidermis (70 +/- 8% of the control, p < 0. 01). Epidermal thinning was associated with a significant decrease in expression of glyceraldehyde-3-phosphate dehydrogenase and beta-actin transcripts (33 +/- 8% of the control epidermis from postoperative day 4, p < 0.001). Other aspects of keratinocyte differentiation, including the patterns of keratin expression, and programmed cell death, were unaltered by skin denervation. These data indicate that skin denervation is sufficient to influence keratinocyte proliferation and therefore epidermal thickness

Neuropathology of Skin Denervation in Acrylamide-Induced Neuropathy

Previous studies have established the neurotoxicity and pathology of acrylamide to large-diameter nerves. It remains unclear (1) whether small- diameter sensory nerves are vulnerable to acrylamide and (2) if so, how the pathology evolves during intoxication. We investigated the influence of acrylamide on small-diameter sensory nerves by studying the pathology of sensory nerve terminals in the skin. The neurotoxic effects of acrylamide (400 ppm in drinking water) on mice were assessed by immunostaining the skin with protein gene product 9.5, a ubiquitin C- terminal hydrolase, particularly useful for demonstrating cutaneous nerve terminals. Within 5 days of acrylamide administration (the initial stage), epidermal nerves showed two major changes: ( 1) terminal swelling and (2) increased branching. There was a progressive reduction in epidermal nerve density (END) thereafter. Fifteen days after acrylamide intoxication (the late stage), reduction in END became evident (25.22 +/- 2.19 fibers/mm vs 41.74 +/- 2.60 fibers/mm in control mice, P < 0.003). At this stage, there was significant dermal nerve degeneration with ultrastructural demonstrations of vacuolar changes. These findings establish the pathological consequences of acrylamide neurotoxicity in cutaneous sensory nerves with far-reaching implications: (1) providing an animal system to study &quot;dying-back&quot; pathology of nociceptive nerves and (2) forming the ultrastructural foundation for interpreting the pathology of cutaneous nerve degeneration in skin biopsies. (C) 2002 Elsevier Science ( USA)