Effects of Antecedent Intravenous Thrombolysis on Endovascular Treatment of Acute Stroke Using Tirofiban.

PURPOSE: To investigate whether preceding intravenous thrombolysis combined with tirofiban in patients with acute ischemic stroke undergoing endovascular treatment is safe and effective. MATERIALS AND METHODS: Consecutive data were identified for patients who experienced acute ischemic stroke and were admitted to 2 comprehensive stroke centers from January 2015 to August 2021. All patients were divided into 2 groups-a thrombolytic with tirofiban group and a tirofiban-alone group-on the basis of whether intravenous thrombolysis before emergency endovascular angioplasty was used. Multivariate regression and propensity adjustment analyses were performed to characterize differences in safety and clinical outcomes between the 2 groups. RESULTS: Of 373 eligible patients, 111 (29.7%) were treated with thrombolysis with tirofiban. There was a significant difference in the rate of any intracerebral hemorrhage (35.1% vs 24.8%; P = .04) but not in the rates of symptomatic intracerebral hemorrhage (16.2% vs 11.5%; P = .23) and reocclusion at 24 hours (5.4% vs 7.6%; P = .51) between the 2 groups. Multivariate regression analysis revealed that intravenous thrombolysis was not associated with any or symptomatic intracerebral hemorrhage, artery occlusion, functional outcome, or death at the 3-month follow-up (all adjusted P > .05). After propensity adjustment, the thrombolytic with tirofiban group showed nonsignificant rates of clinical and safety outcomes compared with those of the tirofiban-alone group (all P > .05). CONCLUSIONS: Tirofiban may be used without increasing the risk of adverse events in selected patients who experienced ischemic stroke and were treated with intravenous thrombolysis and endovascular therapy.

Clinical, laboratory and brain Magnetic Resonance Imaging (MRI) characteristics of asymptomatic and symptomatic HIV-negative neurosyphilis patients.

INTRODUCTION: There are few studies concerning the differences between asymptomatic neurosyphilis (ANS) and symptomatic neurosyphilis (SNS). This study aimed to summarize clinical, laboratory and brain Magnetic Resonance Imaging (MRI) characteristics of HIV-negative patients with ANS and SNS. METHODS: Data from 43 HIV-negative patients with ANS and 59 HIV-negative patients with SNS were retrospectively collected from our hospital between December 2012 and December 2018. RESULTS: Compared with the ANS group, SNS group had more patients that were male, age≥45 years, had brain MRI abnormalities, and exhibited higher serum/cerebrospinal fluid (CSF) TRUST titer, CSF WBC count, CSF protein concentration (P < 0.05). Multivariate regression analysis revealed that male sex, age ≥45 years and CSF TRUST titer were risk factors for SNS [odds ratio (OR) = 7.946,P = 0.001;OR = 3.757, P = 0.041; OR = 2.713, P = 0.002; respectively]. The brain MRI findings of 78 patients without comorbidities showed that ischemic infarct lesions presented in 17/37 (45.95%) of patients with ANS; infarct ischemic stroke (73.17%) especially multiple cerebral infractions (46.34%), cerebral atrophy (48.78%) were also common presentations in the SNS group. CONCLUSIONS: Patients with HIV-negative ANS and SNS presented different clinical, laboratory and brain MRI features. Male sex, age ≥45 years and elevated CSF TRUST titer may have an increased risk of developing neurological symptoms. Brain MRI abnormalities may present prior to clinical symptoms. Multiple cerebral infarctions without explained reasons or cerebral atrophy should alert clinicians the possibility of SNS.

Inhibitory effect of kaempferol on mouse melanoma cell line B16 in vivo and in vitro.

INTRODUCTION: Melanoma is a malignant tumour and is the leading cause of death in patients with skin tumours. AIM: Kaempferol belongs to a class of flavonoids, and is associated with many biological functions such as anti-inflammatory, anti-oxidation and anti-cancer. However, the inhibitory effect of kaempferol on melanoma still remains unclear. MATERIAL AND METHODS: The effect of kaempferol on melanoma was determined by conducting both in vitro and in vivo experiments using MTT assay and flow cytometry. RESULTS: The in vitro results revealed that kaempferol obviously inhibited cell viability of melanoma B16 cells, induced cell cycle arrest and cell apoptosis. The in vivo results showed that kaempferol effectively inhibited the growth of mice xenografts. More importantly, kaempferol down-regulated the number of MDSC cells and up-regulated the number of NKT cells and CD8 T cells in the spleen. CONCLUSIONS: Taken together, these findings indicate that kaempferol might play an inhibitory role in the growth of melanoma by enhancing anti-tumour immunity of organisms.

Efficacy and safety of endovascular thrombectomy in mild ischemic stroke: results from a retrospective study and meta-analysis of previous trials.

BACKGROUND: Mechanical thrombectomy has been proven as a standard care for moderate to severe ischemic stroke with anterior large vessel occlusion (LVO); however, whether it is equally effective in mild ischemic stroke (MIS) is controversial. METHODS: In this retrospective study, a total of 177 Chinese patients presenting with MIS (NIHSS ≤8) and LVO between January 2014 and September 2017 from seven comprehensive stroke centers were identified. Odds of good outcome with endovascular thrombectomy versus medical treatment were obtained by logistic regression analysis and propensity-score matching method, and a meta-analysis pooled results from six studies (n = 733). RESULTS: Good outcome (mRS: 0-1) was 58.2% (46/79) in the thrombectomy and 46.9% (46/98) in the medical group, which showed no statistical significance before adjustment (P = 0.13; OR = 1.57, 95% CI: 0.86 to 2.86). The adjusted ORs of thrombectomy versus medical group were 3.23 (95% CI, 1.35 to 7.73; P = 0.008) by multivariable logistic analysis, 2.78 (1.12 to 6.89; P = 0.02) by propensity score matching analysis, and 3.20 (1.22 to 8.37; P = 0.01) by propensity score matching analysis with additional adjustments, respectively. Thrombectomy treatment did not result in excessive mortality or symptomatic intracranial hemorrhage after adjustments. The meta-analysis did not confirm the associations between good outcome and endovascular treatment. CONCLUSIONS: The current study indicates that endovascular thrombectomy is associated with good functional outcome in MIS patients with LVO, and without additional risk of symptomatic intracranial hemorrhage and mortality. Although the meta-analysis failed to demonstrate its superiority compared to medical treatment, randomized clinical trials are needed.

Selective attention function impairment in HIV-negative patients with early forms of neurosyphilis.

BACKGROUND: The attentional network test (ANT) is widely used to evaluate the performance of three attentional networks: alerting, orienting and executive attention networks. This study aimed to investigate the characteristics of attention functions in HIV-negative patients with early forms of neurosyphilis (NS) and their correlation with abnormalities in brain magnetic resonance imaging (MRI). METHODS: Thirty patients with early forms of NS, 31 patients with syphilis but without NS (Non-NS) and 35 healthy controls were recruited from an HIV-negative cohort between September 2020 and November 2022. The participants were evaluated with the ANT and the Mini-Mental State Examination (MMSE). Brain MRI was performed in NS and Non-NS patients. RESULTS: No significant differences were observed in the MMSE scores among the three groups. However, patients with early forms of NS showed poorer performance in orienting and alerting functions than Non-NS group (F = 6.952, P = 0.011 and F = 8.794, P = 0.004, respectively); No significant difference was observed in executive function between the two groups (F = 0.001, P = 0.980). Multivariate analysis of variance using the Bonferroni post hoc test indicated that patients with NS exhibited less efficient orienting function (P = 0.023), and alerting function (P = 0.003) but not executive function (P = 0.99), compared to Non-NS patients. Additionally, a significant difference was found in orienting function between patients with NS and healthy controls (P < 0.001) compared to healthy controls. MRI scans revealed that the NS group had a higher prevalence of abnormalities in the frontal lobes and/or the temporoparietal junction compared to the Non-NS group (24/25 vs. 13/19, P = 0.032). CONCLUSIONS: The orienting and alerting functions but not executive function were significantly less efficient in early forms of NS group than in the Non-NS group (P < 0.01). This indicates deficits in selective attention in patients with early forms of NS. Brain MRI scans revealed abnormalities in the frontal and/or parietal lobes, as well as the temporoparietal junction, suggesting potential neuropathological correlates of these attentional deficits.

Effect of 5-Aminolevulinic Acid Photodynamic Therapy with Transfer Factor Capsules in the Treatment of Multiple Plantar Warts.

Background: Plantar warts are a common cutaneous disease of the sole of the foot caused by human papillomavirus. Photodynamic therapy has gained increasing attention in the treatment of plantar warts. Objective: To investigate the effect of photodynamic therapy combined with transfer factor capsules in the treatment of multiple plantar warts. Methods: Sixty-one patients with multiple plantar warts who visited our outpatient department from September 2017 to August 2019 were randomly divided into two groups. Twenty-three patients received photodynamic therapy (treatment group) and thirty-eight received cryotherapy (control group). Both groups also received immune modulator transfer factor capsules. Skin lesion score, numeric rating scale- (NRS-) 10 score, recurrence rate, adverse reactions, and Dermatology Life Quality Index (DLQI) were analyzed in both groups. Results: The mean skin lesion score improved from 13.39 ± 3.88 before treatment to 1.48 ± 2.50 after the last treatment in the treatment group and from 12.47 ± 2.99 before treatment to 4.47 ± 3.67 after the last treatment in the control group. The success rate after 3 months of treatment was 86.96% in the treatment group and 39.47% in the control group. After 3 months of follow-up, the recurrence rate was significantly lower in the treatment group (20%) than in the control group (53.33%). The mean DLQI score at three months after treatment was significantly lower in the treatment group (3.61 ± 1.16) than in the control group (6.31 ± 2.59). Conclusion: Photodynamic therapy combined with immunomodulators significantly increased the cure rate and reduced the recurrence rate of multiple plantar warts compared with traditional cryotherapy combined with immunomodulators.

Differences in clinical characteristics and lesion proteomics between inflammatory linear verrucous epidermal nevus and local verrucous epidermal nevus.

BACKGROUND: Verrucous epidermal nevus (VEN) are keratinocytic epidermal nevus that appear at birth or in early childhood. They exhibit a range of manifestations, depending on the patient's age. VEN are rarely encountered in clinical practice, and the systemic and comprehensive clinical characteristics of VEN have not been well investigated. Furthermore, the association between tandem mass tag (TMT)-based quantitative proteomics and the VEN phenotype is still unclear. OBJECTIVES: This study investigated the differences in the clinical characteristics and lesion proteomics between inflammatory linear VEN (ILVEN) and local VEN. METHODS: This retrospective study enrolled 125 patients with histopathologically diagnosed VEN who presented to our hospital between 2019 and 2021. We collected the clinical data of all patients with VEN using a self-designed questionnaire. The expression of proteins in VEN lesions was analyzed using TMT proteomics technology. RESULTS: In total, there were 125 patients with VEN that were evaluated, including 67 (53.60%) patients with local VEN and 58 (46.40%) with ILVEN. No significant differences were found in sex, onset age, and lesion location between patients with local VEN and those with ILVEN (all P > 0.05). Significant differences were found in the onset site and pruritus scores between patients with ILVEN and those with local VEN (all P < 0.05). According to the TMT proteomics results, 89 proteins were up or downregulated with at least 1.3-fold (upregulated: 38, downregulated: 51; P < 0.05) in ILVEN lesions relative to VEN lesions. The top 10 differentially expressed proteins between ILVEN and local VEN lesions were OGN, NT5C3A, ADD1, OLFML1, DHRS1, CALML5, SAMHD1, SFRP2, SPRR1B, and SERPINB13. The upregulated proteins are mainly involved in neutrophil activation, neutrophil-mediated immunity, and p53 signaling pathway (hsa04115). The downregulated proteins are mainly involved in cellular response to cytokine stimulus, cell adhesion, Th1 and Th2 cell differentiation. In total, based on the differentially expressed proteins between ILVEN and local VEN, five pathways that may be associated with the pathogenesis of inflammation, including CAMs (P = 0.006), Th1 and Th2 cell differentiation (P = 0.017), PPAR signaling pathway (P = 0.023), Th17 cell differentiation (P = 0.024), and p53 signaling pathway (P = 0.041). CONCLUSIONS: Clinical data of the patients revealed that ILVEN lesions presented with intense pruritus and inflammatory change. Differentially expressed proteins between ILVEN and local VEN are mainly involved in multiple inflammation related pathways associated with the pathogenesis mechanisms of pruritus. LIMITATIONS: The small sample size in clinical characteristic and proteomics study is one of the most significant limitations in our study. The inflammation associated proteins and signal pathways in the pathogenesis of pruritus in ILVEN is not explored. SIGNIFICANCE: In this study, we found the lesions of ILVEN patients presented with intense pruritus and inflammational change. A total of 89 proteins were up or downregulated with at least 1.3-fold (upregulated: 38, downregulated: 51; P < 0.05) in ILVEN lesions relative to VEN lesions. On the other hand, the etiology of itch in ILVEN mainly associated with inflammation, but the exact mechanisms was still unclear. We found the differentially expressed proteins between ILVEN and local VEN enriched five pathways that may be associated with the pathogenesis of inflammation and pruritus.

Follow-up study identifies two novel susceptibility loci PRKCB and 8p11.21 for systemic lupus erythematosus.

OBJECTIVE: We have performed a large-scale replication study based on our previous genome-wide association study (GWAS) of SLE in the Chinese Han population to further explore additional genetic variants affecting susceptibility to SLE. METHODS: Thirty-eight single nucleotide polymorphisms from our GWAS were genotyped in two additional Chinese Han cohorts (total 3152 cases and 7050 controls) using the Sequenom Massarray system. Association analyses were performed using logistic regression with gender or sample cohorts as a covariate. RESULTS: Association evidence for rs16972959 (PRKCB at 16p11.2) and rs12676482 (8p11.21) with SLE was replicated independently in both replication cohorts (P < 0.05), showing high significance for SLE in combined all 4199 cases and 8255 controls of Chinese Han [rs16972959: odds ratio (OR) = 0.81; 95% CI 0.76, 0.87; P(combined) = 1.35 × 10(-9); rs12676482: OR = 1.26; 95% CI 1.15, 1.38; P(combined) = 6.68 × 10(-7)). PRKCB is related to the established SLE immune-related pathway (NF-κB) and 8p11.21 contains important candidate genes such as IKBKB and DKK4. IKBKB is a critical component of NF-κB and DKK4 is an inhibitor of canonical Wnt signalling pathway. Interestingly, PRKCB is required for recruiting IKBKB into lipid rafts, up-regulating NF-κB-dependent survival signal. CONCLUSIONS: Our findings provided novel insights into the genetic architecture of SLE and emphasized the contribution of multiple variants of modest effect. Further study focused on PRKCB, 8p11.21, should advance our understanding on the pathogenesis of SLE.

Down-regulated expression of IKZF1 mRNA in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease with complex genetic inheritance. IKZF1 was established as a new susceptibility gene for SLE in a recent genome-wide association study (GWAS) in Chinese Han population. In order to examine whether expression levels of IKZF1 contribute to the pathogenesis of SLE, we estimated IKZF1 mRNA expression levels in peripheral blood mononuclear cells (PBMCs) via fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) in 60 patients with SLE and 60 controls. We also explored whether the IKZF1 mRNA expression levels are associated with the variant of the SNP rs4917014 and the SLE Disease Activity Index (SLEDAI). The expression levels of IKZF1 mRNA in patients with SLE were significantly decreased compared with those in healthy controls (P<0.001). No significant differences were found between IKZF1 mRNA expression levels and SLEDAI scores, SNP rs4917014. Our results suggest that decreased expression of IKZF1 mRNA may be correlated with the pathogenesis of SLE.

Combination of the neutrophil to lymphocyte ratio and serum toluidine red unheated serum test titer as a predictor of neurosyphilis in HIV-negative patients.

The present study explored the associations of the neutrophil to lymphocyte ratio (NLR) and the serum toluidine red unheated serum test (TRUST) titer with neurosyphilis (NS). The present retrospective study examined 87 NS patients and 80 Non-NS patients from an HIV-negative cohort and 1:1 age- and gender-matched healthy controls. The results demonstrated that the NLR was increased in both NS and Non-NS groups compared with that in the healthy controls (P<0.001 and P=0.01, respectively). The NLR and serum TRUST titer in the NS group were significantly higher than those in the Non-NS group (P=0.004 and P<0.001, respectively). The NLR was positively correlated with the serum TRUST titer (r=0.298, P<0.001). Age, elevated NLR and serum TRUST titer were distinctly associated with NS by binomial logistic regression analysis [odds ratio (OR)=1.10, P<0.001; OR=1.36, P=0.028; OR=3.07, P<0.001; respectively]. The cut-off values for the NLR and serum TRUST titer were 1.97 and 1:8, respectively. A significantly higher sensitivity of 90.8% was obtained for screening out NS with a combination of the NLR and serum TRUST titer compared with each test alone. Age, elevated NLR and serum TRUST titer were associated with NS. The combination of NLR and serum TRUST titer is a potential predictor for NS, and the reduced NLR and serum TRUST titer at the 6-month follow up suggested that the NLR and serum TRUST titer were biomarkers for monitoring the disease course.

Platelet-derived growth factor receptor alpha gene mutations in vitiligo vulgaris.

Vitiligo vulgaris is an acquired depigmenting disorder resulting from the loss of melanocytes in the skin. Though several putative susceptibility loci of vitiligo have been identified in different populations, the pathogenesis of the disease remains poorly understood. Through genetic linkage analysis of a large Chinese family cohort of vitiligo, we identified a vitiligo linkage locus AIS4 within chromosome 4q12-q21, a region containing several possible candidate genes, including the platelet-derived growth factor receptor alpha (PDGFRA) gene. We postulated that PDGFR mutations may be linked with vitiligo. To test this hypothesis, we performed DNA sequencing on this gene in 143 multiplex families with familial vitiligo vulgaris, 480 patients with sporadic vitiligo vulgaris, and 480 healthy subjects. Mutations were found in 3.5% of familial vitiligo cases, which is significantly higher than for the general population (0.42%, p = 0.008, Fisher's exact test), and possibly higher than in sporadic vitiligo patients (1.0%, p = 0.053). To our knowledge, this is the first observation that PDGFRA mutations are linked with familial vitiligo vulgaris.

Neuroimaging Features, Follow-Up Analyses, and Comparisons Between Asymptomatic and Symptomatic Neurosyphilis.

INTRODUCTION: Many studies have explored the imaging characteristics of patients with neurosyphilis, but no systematic study has been made on the neuroimaging changes after anti-syphilitic treatment. The purpose of this study was to examine neuroimaging differences before and after treatment, comparing patients with asymptomatic and symptomatic neurosyphilis. METHODS: A total of 102 patients with neurosyphilis, including 60 cases of symptomatic neurosyphilis and 42 cases of asymptomatic neurosyphilis, were identified between December 2012 and June 2019. Their demographics, medical histories, serological tests of peripheral blood and cerebrospinal fluid, and especially neuroimaging features before and after anti-syphilitic treatment were collected and analyzed. RESULTS: The patients presented with variable clinical and neuroimaging features, including cerebral infarction or hemorrhage, atrophy, demyelination, arteritis, encephalitis, and hippocampal sclerosis. A total of 29 neuroradiological re-examinations were performed in 19 patients treated with anti-syphilitic medicine. The results indicated that some patients still presented neuroradiological progression after treatment, including 42.1% showing infarction lesions, 47.4% mild to severe brain atrophy, and 15.8% white matter demyelination. CONCLUSION: The clinical and neuroimaging features of neurosyphilis patients are diverse, and their follow-up neuroimaging continued to show progression even with standardized treatment.

Three-dimensional visualization of the functional fascicular groups of a long-segment peripheral nerve.

The three-dimensional (3D) visualization of the functional bundles in the peripheral nerve provides direct and detailed intraneural spatial information. It is useful for selecting suitable surgical methods to repair nerve defects and in optimizing the construction of tissue-engineered nerve grafts. However, there remain major technical hurdles in obtaining, registering and interpreting 2D images, as well as in establishing 3D models. Moreover, the 3D models are plagued by poor accuracy and lack of detail and cannot completely reflect the stereoscopic microstructure inside the nerve. To explore and help resolve these key technical problems of 3D reconstruction, in the present study, we designed a novel method based on re-imaging techniques and computer image layer processing technology. A 20-cm ulnar nerve segment from the upper arm of a fresh adult cadaver was used for acetylcholinesterase (AChE) staining. Then, 2D panoramic images were obtained before and after AChE staining under the stereomicroscope. Using layer processing techniques in Photoshop, a space transformation method was used to fulfill automatic registration. The contours were outlined, and the 3D rendering of functional fascicular groups in the long-segment ulnar nerve was performed with Amira 4.1 software. The re-imaging technique based on layer processing in Photoshop produced an image that was detailed and accurate. The merging of images was accurate, and the whole procedure was simple and fast. The least square support vector machine was accurate, with an error rate of only 8.25%. The 3D reconstruction directly revealed changes in the fusion of different nerve functional fascicular groups. IN CONCLUSION: The technique is fast with satisfactory visual reconstruction.

Effect of platelet-rich plasma (PRP) concentration on proliferation, neurotrophic function and migration of Schwann cells in vitro.

Platelet-rich plasma (PRP) contains various growth factors and appears to have the potential to promote peripheral nerve regeneration, but evidence is lacking regarding its biological effect on Schwann cells (SCs). The present study was designed to investigate the effect of PRP concentration on SCs in order to determine the plausibility of using this plasma-derived therapy for peripheral nerve injury. PRP was obtained from rats by double-step centrifugation and was characterized by determining platelet numbers and growth factor concentrations. Primary cultures of rat SCs were exposed to various concentrations of PRP (40%, 20%, 10%, 5% and 2.5%). Cell proliferation assays and flow cytometry were performed to study to assess SC proliferation. Quantitative real-time PCR and ELISA analysis were performed to determine the ability of PRP to induce SCs to produce nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF). Microchemotaxis assay was used to analyse the cell migration capacity. The results obtained indicated that the platelet concentration and growth factors in our PRP preparations were significantly higher than in whole blood. Cell culture experiments showed that 2.5-20% PRP significantly stimulated SC proliferation and migration compared to untreated controls in a dose-dependent manner. In addition, the expression and secretion of NGF and GDNF were significantly increased. However, the above effects of SCs were suppressed by high PRP concentrations (40%). In conclusion, the appropriate concentration of PRP had the potency to stimulate cell proliferation, induced the synthesis of neurotrophic factors and significantly increased migration of SCs dose-dependently. Copyright © 2013 John Wiley & Sons, Ltd.

Improved peripheral nerve regeneration using acellular nerve allografts loaded with platelet-rich plasma.

Acellular nerve allografts (ANAs) behave in a similar manner to autografts in supporting axonal regeneration in the repair of short peripheral nerve defects but fail in larger defects. The objective of this article is to evaluate the effect of ANA supplemented with platelet-rich plasma (PRP) to improve nerve regeneration after surgical repair and to discuss the mechanisms that underlie this approach. Autologous PRP was obtained from rats by double-step centrifugation and was characterized by determining platelet numbers and the release of growth factors. Forty-eight Sprague-Dawley rats were randomly divided into 4 groups (12/group), identified as autograft, ANA, ANA loaded with PRP (ANA+PRP), and ANA loaded with platelet-poor plasma (PPP, ANA+PPP). All grafts were implanted to bridge long-gap (15 mm) sciatic nerve defects. We found that PRP with a high platelet concentration exhibited a sustained release of growth factors. Twelve weeks after surgery, the autograft group displayed the highest level of reinnervation, followed by the ANA+PRP group. The ANA+PRP group showed a better electrophysiology response for amplitude and conduction velocity than the ANA and ANA+PPP groups. Based on histological evaluation, the ANA+PRP and autograft groups had higher numbers of regenerating nerve fibers. Quantitative real-time polymerase chain reaction (qRT-PCR) demonstrated that PRP boosted expression of neurotrophins in the regenerated nerves. Moreover, the ANA+PRP and autograft groups showed excellent physiological outcomes in terms of the prevention of muscle atrophy. In conclusion, ANAs loaded with PRP as tissue-engineered scaffolds can enhance nerve regeneration and functional recovery after the repair of large nerve gaps nearly as well as autografts.

Human peripheral nerve-derived scaffold for tissue-engineered nerve grafts: histology and biocompatibility analysis.

Human acellular nerve grafts (ANGs) have been rarely used to construct tissue-engineered nerves compared to the animal-derived ANGs, and their potential clinical applications were relatively unknown. In this study, it was aimed to investigate the structure and components of a scaffold derived from human peripheral nerve and evaluate its biocompatibility. The human peripheral nerves were processed to prepare the scaffolds by chemical extraction. Light and electron microscopy were carried out to analyze scaffold structure and components. The analysis of cytotoxicity, hemolysis, and skin sensitization were performed to evaluate their biocompatibility. It was shown that Schwann cells and axons, identified by S-100 and neurofilament (NF) expression, were absent, and the scaffolds were cell-free and rich in collagen-I and laminin whose microarchitecture was similar to the fibrous framework of human peripheral nerves. It was revealed from biocompatibility tests that the scaffolds had very mild cytotoxicity and hemolysis, whereas skin sensitization was not observed. The constructed human peripheral nerve-derived scaffolds with well biocompatibility for clinical practice, which were cell-free and possess the microstructure and extracellular matrix (ECM) of a human nerve, might be an optimal scaffold for tissue-engineered nerve grafts in human.

[Key technologies of functional fascicular groups three dimensional visualization of long segmented peripheral nerve based on two-time imaging technique and automatic registration].

OBJECTIVE: To explore and solve the key technologies of the three dimensional (3D) visualization reconstruction of functional fascicular groups inside long segmented peripheral nerve. METHODS: A 20 cm ulnar nerve from upper arm of fresh adult dead body was embedded by OCT with four pieces of woman's hair which was used as locating material, then the samples were serially horizontally sliced into 400 slices with 15 microm thickness and 0.5 mm interval. All slices were stained with acetylcholinesterase (AchE) histochemical staining. After that, the 2D panorama images of the same slice were obtained with Olympus stereomicroscope and MSHOT MD90 micro figure image device before and after AchE staining. Using the layer processing technique of Photoshop image processing software, the decomposition images including complete 4 location pots were obtained, based on which the algorithm of optimized least square support vector machine (Optimized LS-SVM) and space transformation method was used to fulfill automatic registration. Finally, with artificial assistant outline obtaining, the 3D visualization reconstruction model of functional fascicular groups of 20 cm ulnar nerve was made using Amira 4.1, and the effects of reverse reduction and the suitability of 3D reconstruction software were evaluated. RESULTS: The two-time imaging technique based on the layer process of Photoshop image processing software had the advantages: the image outline had high goodness of fit; the locating pots of merging image was accurate; and the whole procedure was simple and fast. The algorithm of Optimized LS-SVM had high degree of accuracy, and the error rate was only 8.250%. The 3D reconstruction could display the changes of the chiastopic fusion of different nerve functional fascicular groups directly. It could extract alone, merge and combine arbitrarily, and revolve at any angles. Furthermore, the reverse reduction on arbitrarily level dissection of the 3D model was very accurately. CONCLUSION: Based on the two-time imaging technique and computer image layer processing technology, the compute algorithm of auto-registration can be developed and applied to 3D visualization reconstruction of long segmented peripheral nerve. The technological processes is fast, and the reconstruction effect is good.