Bio-artificial skin composed of gelatin and (1-->3), (1-->6)-beta-glucan

Porous scaffolds composed of gelatin and beta-glucan were prepared using the freeze-drying method. The scaffold had an inter-connected pore structure with average pore size of 90-150 microm. Results for the contact angle and cell attachment revealed that a high gelatin content was suitable for cellular attachment and distribution in two- or three-dimensional fibroblast cultures, because the gelatin had acidic residues, and arginine-glycine-aspartic acid groups. To prepare a stratified wound dressing to mimic the normal human skin, fibroblasts and keratinocyte cells were isolated from a child's foreskin, and were co-cultured in gelatin/beta-glucan scaffolds were cross-linked using 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide hydrochloride. An in vivo study showed that after 1 week, the artificial dermis containing the fibroblasts enhanced the re-epithelialization of a full-thickness skin defect rather than the acellular scaffold.     

TNF and TNF receptor polymorphisms in Korean Behcet's disease patients

Behcet's disease (BD) is an autoimmune disease characterized by recurrent oral ulcers, genital ulcers, erythema nodosum, and uveitis. Genetic factors are considered important in its pathogenesis. The serum level of tumor necrosis factor (TNF) is elevated in patients with active BD, and its production is elevated in monocytes and in the gamma delta T cells of BD patients. A dramatic response to anti-TNF-alpha antibody treatment further supports the role of TNF in BD. In this study, we investigated genetic polymorphisms of TNF alpha -308 G/A, TNF beta +252 G/A, and TNFR2 196 R/M in 94 Korean BD patients and age- and sex-matched healthy controls to investigate the role of TNF and TNF receptor polymorphisms in BD. The polymerase chain reaction-restriction fragment length polymorphism was used to identify the TNF-alpha promoter (G = TNFA1, A = TNFA2) and TNF-beta intron polymorphisms (G = TNFB1, A = TNFB2), and polymerase chain reaction-singly-strand conformation polymorphism was used to identify TNFR2 196R/M polymorphism (T = TNFR2M, G = TNFR2R). No differences were found in the TNF-alpha, TNF-beta or TNFR2 polymorphisms of the patients and the healthy controls. The allele frequencies of TNFA1/A2 were 0.94/0.06 in patients and 0.96/0.04 in healthy controls (p = 0.36, OR = 0.65, 95% CI = 0.26-1.63), for TNFB1/TNFB2 these were 0.42/0.58 in patients and 0.44/0.56 in controls (p = 0.68, OR = 0.91, 95% CI = 0.61-1.38), and for TNFR2R/TNFR2M 0.23/0.77 in patients and 0.21/0.79 in controls (p = 0.62, OR = 1.13, 95% CI = 0.69-1.84). In conclusion, this study found no differences of TNF alpha -308 G/A, TNF beta +252 G/A or of the TNFR2 196R/M polymorphisms in Korean BD patients versus healthy controls. These findings suggest that the role of TNF in BD is not genetically determined, but can be functionally explained.     

Differences in host susceptibility to disease progression in the human challenge model of Haemophilus ducreyi infection

With human volunteers inoculated at two sites with Haemophilus ducreyi, outcomes for a subject were not independent. In a reinfection trial, 2 of 11 previous pustule formers and 6 of 10 previous resolvers resolved all sites of infection. There was no correlation between serum bactericidal or phagocytic activity and outcome in the trial. These data indicate that different hosts are differentially susceptible to disease progression versus resolution in the model.     

Clinical and biological implications of CD133-positive and CD133-negative cells in glioblastomas

A number of recent reports have demonstrated that only CD133-positive cancer cells of glioblastoma multiforme (GBM) have tumor-initiating potential. These findings raise an attractive hypothesis that GBMs can be cured by eradicating CD133-positive cancer stem cells (CSCs), which are a small portion of GBM cells. However, as GBMs are known to possess various genetic alterations, GBMs might harbor heterogeneous CSCs with different genetic alterations. Here, we compared the clinical characteristics of two GBM patient groups divided according to CD133-positive cell ratios. The CD133-low GBMs showed more invasive growth and gene expression profiles characteristic of mesenchymal or proliferative subtypes, whereas the CD133-high GBMs showed features of cortical and well-demarcated tumors and gene expressions typical of proneuronal subtype. Both CD133-positive and CD133-negative cells purified from four out of six GBM patients produced typical GBM tumor masses in NOD-SCID brains, whereas brain mass from CD133-negative cells showed more proliferative and angiogenic features compared to that from CD133-positive cells. Our results suggest, in contrast to previous reports that only CD133-positive cells of GBMs can initiate tumor formation in vivo CD133-negative cells also possess tumor-initiating potential, which is indicative of complexity in the identification of cancer cells for therapeutic targeting.     

Acetazolamide-challenged perfusion magnetic resonance imaging for assessment of cerebrovascular reserve capacity in patients with symptomatic middle cerebral artery stenosis: comparison with technetium-99m-hexamethylpropyleneamine oxime single-photon emission computed tomography

Objectives

Acetazolamide-challenged perfusion magnetic resonance imaging (MRI) has been shown as a method for assessment of cerebrovascular reserve (CVR) capacity in patients with atherosclerotic steno-occlusive disease of internal carotid artery. We have assessed the feasibility of the acetazolamide-challenged perfusion MRI for evaluating CVR in symptomatic patients with severe middle cerebral artery (MCA) stenosis (≥70%) by comparison with the acetazolamide-challenged technetium-99m-hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT).

Methods

Seventeen prospectively enrolled patients with symptomatic unilateral MCA stenosis underwent technetium-99m-hexamethylpropyleneamine oxime SPECT and perfusion MRI without and with acetazolamide challenge, respectively. Acetazolamide-challenged SPECT and perfusion MRI were compared quantitatively by Region of interest (ROI) analysis.

Results

At all ROIs, there were no significant differences in percent change between SPECT and perfusion MRI. Patients with impaired CVR showed significant decreases in the percent changes of respective cerebral blood flow (P=.016) and respective cerebral blood volume (P=.029).

Conclusion

Acetazolamide-challenged perfusion MRI is feasible for evaluating CVR in symptomatic patients with severe MCA stenosis quantitatively.     

Interbrain phase synchronization during turn‐taking verbal interaction—a hyperscanning study using simultaneous EEG/MEG

Recently, neurophysiological findings about social interaction have been investigated widely, and hardware has been developed that can measure multiple subjects' brain activities simultaneously. These hyperscanning studies have enabled us to discover new and important evidences of interbrain interactions. Yet, very little is known about verbal interaction without any visual input. Therefore, we conducted a new hyperscanning study based on verbal, interbrain turn‐taking interaction using simultaneous EEG/MEG, which measures rapidly changing brain activities. To establish turn‐taking verbal interactions between a pair of subjects, we set up two EEG/MEG systems (19 and 146 channels of EEG and MEG, respectively) located ～100 miles apart. Subjects engaged in verbal communication via condenser microphones and magnetic‐compatible earphones, and a network time protocol synchronized the two systems. Ten subjects participated in this experiment and performed verbal interaction and noninteraction tasks separately. We found significant oscillations in EEG alpha and MEG alpha/gamma bands in several brain regions for all subjects. Furthermore, we estimated phase synchronization between two brains using the weighted phase lag index and found statistically significant synchronization in EEG and MEG data. Our novel paradigm and neurophysiological findings may foster a basic understanding of the functional mechanisms involved in human social interactions. Hum Brain Mapp 39:171–188, 2018. © 2017 Wiley Periodicals, Inc.     

Microsurgical resection of deep-seated lesions using transparent tubular retractor: pediatric case series

Background  

To facilitate effective resection of deep-seated brain lesions without causing significant trauma to the overlying cortex, the authors used a transparent plastic tubular retractor to approach these lesions.