Preliminary Study on Functional and Aesthetic Reconstruction by Using a Small Artery-only Free Medial Flap of the Second Toe for Fingertip Injuries

OBJECTIVES

This study was designed to introduce the feasibility of fingertip reconstruction by using a free medial flap of the second toe without vein anastomosis.

METHODS

In total, 8 patients with fingertip injuries were treated successfully with this method. Patients who underwent reconstruction from September 2016 to October 2017 in our hospital with an artery-only free medial flap transfer of the second toe for fingertip injuries were included, and patients who underwent additional procedures that may impact the postoperative results and were followed up for less than 6 months were excluded. Clinical trial registration: ChiCTR19000021883.

RESULTS

According to the Allen classification, five patients had Type 3 injuries, and three patients had Type 4 injuries. One arterial nerve and one digital nerve were repaired at the same time. No additional dissection was performed in either the donor or recipient site of the dorsal or volar vein. Postoperative venous congestion was monitored based on the color, temperature and the degree of tissue oxygen saturation. The flap size ranged from 1.20*1.0 cm2 to 1.80*1.0 cm2. The reconstruction time was 71.86 (SD 14.75) minutes. The two-point discrimination and the monofilament results were satisfying; cold intolerance did not appear in five patients, and the other three patients had cold intolerance with grades of 4, 12 and 26, which were considered satisfactory. Moreover, leech therapy, continuous bleeding and needle sutures were not utilized in any cases.

CONCLUSIONS

Reconstruction with a small artery-only free medial flap transfer of the second toe led to satisfactory sensory and motor function in the selected patients with fingertip injuries.

Surgical management and outcomes of duodenal gastrointestinal stromal tumors

BACKGROUND AND STUDY AIMS

This retrospective study purports to examine these characteristics and compare the surgical procedures available and appropriate for the treatment of patients affected by duodenal GISTs.

PATIENTS AND METHODS

A retrospective examination of reports and studies carried out between May 2012 and March 2017, and covering patients with primary GISTs of the duodenum was performed using modules from the SPSS package. Comparisons of treatment effects resulting from the administration of two differential methods of surgical treatment namely pancreaticoduodenectomy (PD), and limited resection (LR), were effected on the reports of the GIST patients thus selected.

RESULTS

Out of these 62 patients who had undergone resection of duodenal GISTs, 47 (76%) had limited resection (LR) and 15 (24%) underwent pancreaticoduodenectomy (PD). In Multivariate analyses, tumor size was an independent predictive factor for recurrence (p=0.008). ASA, tumor size, and PD were independent and significant prognostic factors on OS (p=0.021, p=0.024, and p=0.030, respectively). In the very low and low risk group, and high-risk group, there were no significant differences in the RFS (recurrence-free survival) and OS (overall survival) between the LR and PD groups.

CONCLUSIONS

When technically feasible, LR should be given due consideration as a reliable and curative option for duodenal GISTs achieving satisfactory RFS and OS.

[Prognostic influence of preoperative Nutritional Risk Screening -2002 (NRS-2002) score for patients with thoracic esophageal squamous cell carcinoma receiving surgery]

Objective: To apply Nutritional Risk Screening-2002(NRS-2002) to perform nutritional status score for the patients with thoracic esophageal squamous cell carcinoma (ESCC) receiving surgery, and to explore the prognostic impact of long-term survival. Methods: A total of 117 patients who were diagnosed with ESCC from 2010 to 2012 were retrospectively analyzed. They recieved standard curative esophagectomy in the Yangzhou University Affiliated Taixing People's Hospital. The nutritional status and risk score for recruited patients were assessed according to the standard of NRS-2002 tool prior to surgery, and these patients were grouped for further analysis according to the median values of NRS-2002 score. Finally, the relationship between NRS-2002 score and prognosis was analyzed. Results: Patients were classified into two groups, with 45 in the NRS-2002<2.0 group, and 72 cases in the NRS-2002≥2.0, respectively. In the NRS-2002<2.0 group, the 1-, 3-, and 5-year progression-free survival (PFS) rates were 75.6%, 44.4% and 40.0% separately, while in the NRS-2002≥2.0 group, the PFS rates were 61.1%, 6.9% and 4.2% respectively, and the differences were statistically significant (P<0.001). Correspondingly, in the NRS-2002< 2.0 group, the 1-, 3-, and 5-year overall survival (OS) rates were 97.8%, 66.7% and 57.8% separately, while in the NRS-2002≥2.0 group, the OS rates were 91.7%, 33.3% and 16.7% respectively, and the differences were also statistically significant (P<0.001). Univariate analysis showed that N stage, TNM stage and NRS-2002 score were closely related to PFS and OS (P<0.05), and T stage was only associated with OS in patients with thoracic esophageal squamous cell carcinoma (P<0.05). Furthermore, multivariate Cox regression analysis showed that N stage (RR=1.640, 95% CI 1.049-2.565, P=0.030) and NRS-2002 (RR=3.154, 95% CI 1.946-5.113, P<0.001) were independent prognostic factors for PFS in patients with ESCC after surgery. Additionally, pathological differentiation (RR=1.556, 95% CI 1.004-2.440, P=0.041), N stage (RR=1.624, 95% CI 1.017-2.593, P=0.042) and NRS-2002 (RR=3.906, 95% CI2.245-6.795, P<0.001) were independent prognostic factors for OS in ESCC patients following surgery. Conclusion: Preoperative nutritional risk screening NRS-2002 score is an independent prognostic factor in patients with ESCC receiving surgery and could be used as a tool for primary screening for nutritional risk.

MAGE-A is frequently expressed in triple negative breast cancer and associated with epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is a crucial step in tumor metastasis. Triple negative (TN) breast cancer, a high metastasis phenotype, has been verified to be associated with EMT. Melanoma associated antigen-A (MAGE-A) is exclusively expressed in cancers with high aggressiveness as well as unfavorable prognosis and likely to be associated with EMT of triple negative breast cancer (TNBC). The aim of the study is to analyze the expression profile of MAGE-A in breast cancer and the correlation between MAGE-A and EMT of TNBC. Immunohistochemistry (IHC) was performed to assess the prevalence of MAGE-A, vimentin, E-cadherin and β-catenin in breast cancer tissues and correlate them with clinical pathological parameters. The association between MAGE-A and EMT markers was also evaluated. Scratch assay and transwell invasion assay were carried out to evaluate the impact of MAGE-A down-regulation on migration and invasion of the breast cancer cells. Real-time PCR was also conducted to evaluate alterations in EMT markers with decrease in MAGE-A. The results showed that MAGE-A was absent in normal tissue but expressed in tumor samples with the incidence of 49.17% (P=0.008). MAGE-A staining was higher in TNBC (76.47%, 13/17), followed by HER-2(+) (53.85%, 7/13) and Luminal set (43.33%, 39/90), and it was significantly correlated with ER (-), PR (-), HER-2 (-), lymph nodes involvement and higher histological grade (P<0.05). E-cadherin-positivity was frequent in Luminal set (94.44%, 85/90) and linked to ER (+), negative lymph nodes and lower histological grade (P<0.05). Vimentin expression was often observed in TNBC (70.56%, 12/17) and ER (-), PR (-), lymph nodes (+) groups (P<0.05). Expression of β-catenin was prevalent in Luminal set (93.33%, 84/90) and correlated with ER (+), PR (+) and lower histological grade (P<0.05). MAGE-A was inversely associated with E-cadherin (P=0.011) and β-catenin (P=0.048) but expressed in the same trend with vimentin (P=0.000). Migration and invasion of MDA-MB-231 were inhibited when MAGE-A decreased. Increase in epithelial markers and decline in mesenchymal indicators were also seen with MAGE-A reduction. Snail, Slug, ZEB1 and ZEB2 were also down-regulated. In conclusion, MAGE-A may be responsible for high aggressiveness and EMT of TNBC and can be a new choice for targeted therapy.

[Epidemiological investigation and analysis of an outbreak of mycoplasma pneumoniae pneumonia in adult]

Objective: To conduct an epidemiological investigation and analysis of an outbreak of mycoplasma pneumonia in adults. Methods: The first case was a 23-year-old male came from the Third Military Medical University, who served as an intern in the Fuzhou General Hospital of PLA and presented on July 16, 2015 with a history of low-grade fever, dizziness, fatigue and chest tightness. Chest CT revealed pulmonary nodules shadow. It was found that other 11 individuals who had been in close contact with the first patient also had similar pulmonary nodules shadow after chest CT examination. Immediately, the health and epidemic prevention department of the ministry of health of Nanjing Military Command and the disease prevention and control center of the Nanjing Military Command received a phone call from Fuzhou General Hospital of PLA. Upon arrival, the prevention and control team conducted a series of epidemiological investigations and on-site prevention, control and disposal of the event, and conducted chest CT screening for other 289 students and staff who volunteered to be examined living in the same area. After the patients with similar pulmonary nodules shadow were screened out, mycoplasma antibody titer detection and chest CT re-scanning were performed for compliance patients. Results: There were 301 students living in the dormitories (Building A and B) of the student living area, and they were screened by chest CT, and it was found that 27 of them had pulmonary nodules shadow, including single pulmonary nodules shadow (48.1%, 13 out of 27) and multiple pulmonary nodules shadow (51.9%, 14 out of 27). And halo sign was observed in 25 of 27 patients (92.6%). The majority of the 27 patients were asymptomatic, only 2 patients got cough, a few of them had systemic symptoms such as fever, dizziness, fatigue. The positive rate of pulmonary nodules shadow was 32.8% (22/67) in building A (poor environmental hygiene), 2.14% (5/234) in building B, and the total incidence rate was 8.97%. Four-fold increase in the mycoplasma pneumoniae (MP) antibody titer in the paired sera was observed in first 12 patients. Measures such as disinfection, isolation and sanitation were taken to control the spread of the epidemic. There was no serious and death cases on the basis of active treatment on the affected patients. Conclusions: The outbreak of mycoplasma pneumoniae pneumonia often occur in crowded places. And the clinical and imaging features of mycoplasma pneumoniae pneumonia are atypical. Standard epidemiological intervention should be adopted for the sudden onset of respiratory diseases with unknown causes.

Realization of continuous electron doping in bulk iron selenides and identification of a new superconducting zone

It is known that iron selenide superconductors exhibit unique characteristics distinct from iron pnictides, especially in the electron-doped region. However, a comprehensive study of continuous carrier doping and the corresponding crystal structures of FeSe is still lacking, mainly due to the difficulties in controlling the carrier density in bulk materials. Here we report the successful synthesis of a new family of bulk Lix(C3N2H10)0.37FeSe, which features a continuous superconducting dome harboring Lifshitz transition within the wide range of 0.06 ⩽ x ⩽ 0.68 . We demonstrate that with electron doping, the anion height of FeSe layers deviates linearly away from the optimized values of pnictides and pressurized FeSe. This feature leads to a new superconducting zone with unique doping dependence of the electronic structures and strong orbital-selective electronic correlation. Optimal superconductivity is achieved when the F e 3 d t 2 g orbitals have almost the same intermediate electronic correlation strength, with moderate mass enhancement between 3 ~ 4 in the two separate superconducting zones. Our results shed new light on achieving unified mechanism of superconductivity in iron-based superconductors.

Similar Effect of P16 Hydroxymethylation and True Methylation on Prediction of Malignant Transformation of Oral Epithelial Dysplasia: A Prospective Study

Background: Total P16 methylation (P16M), including P16 hydroxymethylation (P16H) and true-P16M, correlates with malignant transformation of oral epithelial dysplasia (OED). Both true-P16M and P16H are early events in carcinogenesis. Aim: The aim of this study is to prospectively determine if discrimination of true-P16M from P16H similarly is necessary for prediction of cancer development from OEDs. Methods: Patients (n = 265) with mild or moderate OED were recruited into the double-blind 2-center cohort. Total-P16M and P16H were analyzed using the 115-bp MethyLight, TET-assistant bisulfite (TAB) methylation-specific PCR (MSP), and TAB-sequencing. Total-P16M-positive and P16H-negative samples were defined as true-P16M-positive. Progression of OEDs was monitored for a minimum 24 months follow-up period. Results: P16H was detected in 23 of 73 (31.5%) total-P16M-positive OEDs. Follow-up information was obtained from 247 patients with an ultimate compliance of 93.2%. OED-derived squamous cell carcinomas were observed in 13.0% (32/247) patients during the follow-up (median, 41.0 months). The cancer progression rate for total-P16M-positive patients was significantly increased when compared with total-P16M-negative patients (23.3% vs 8.6%; adjusted odds ratio = 2.67 [95% CI: 1.19-5.99]). However, the cancer progression rate was similar between P16H- and true-P16M-positive OEDs (26.1% [6/23] vs 22.0% [11/50]; odds ratio = 0.80 [95% CI: 0.22-2.92]). The progression-free survival was also similar for these patients. Conclusion: P16H and true-P16M are similar biomarkers for determining malignant potential of OEDs. Discrimination of P16H from true-P16M, at least in OED, may be not necessary in clinical applications.

Determination of chidamide in rat plasma and cerebrospinal fluid

Chidamide is a new subtype-selective histone deacetylase inhibitor (HDACi), which has been approved for the treatment of recurrent or refractory peripheral T-cell lymphoma (PTCL) in China. However, there are few studies about the application of chidamide in PTCL with central nervous system (CNS) involvement. It is essential to investigate the penetration of chidamide in the blood brain barrier (BBB). LC-MS methods were established firstly to determine the concentration of chidamide in rat plasma and CSF. Then five rats were anaesthetized and the plasma and CSF samples were collected at the time of 5, 15, 30, 60, 120, 180, 240, 360 and 480 min after being administered 1 mg/kg chidamide by intravenous injection, respectively. All samples were analyzed with the established LC-MS method by using the precursor/product transitions (m/z) of 391.1/265.1 for chidamide and 441.1/138.2 for internal standard (IS). The PK parameters were calculated after both of the concentrations of chidamide in plasma and CSF were determined. The penetration ratio of chidamide in BBB ranged from 0.19% to 0.67%. Result indicated chidamide could pass through the BBB, enter into the CNS and have the potential to be utilized in PTCL with CNS involvement.

[Construction of Chinese peripheral nerve society and progress in repair and reconstruction of peripheral nerve injury]

The peripheral nerve group of the reparative and reconstructive surgery committee (branch of Chinese association of rehabilitation medicine) was established in 1995. Major research progress has been made in the repair, regeneration, and reconstruction of peripheral nerve injury. Professor GU Yudong initiated the contralateral cervical7 root (CC7) transfer for the treatment of total brachial plexus root injury in 1986. Now this method has been applied safely and effectively for 30 years with profound progress and refinement. In addition, the repair and reconstruction of peripheral nerve injury had achieved great development such as the treatment of spastic paralysis of upper limb, CC7 transfer using a modified prespinal route, the reconstruction of bladder function after spinal cord injury, the development of acellular allograft nerve, the small gap suture technique, the functioning free gracilis muscle transplantation, and contralateral S ₁ transfer which have been widely used in clinical application with good outcomes. With the progress of the biological manufacturing of peripheral nerve bio-materials and the remodeling of central nervous system after brachial plexus injury, a novel peripheral neuroscience research field was growing up. It is still a challenge for surgeons and scholars in this field to insist on the popularization and improvement of peripheral nerve repair and reconstruction by microsurgical technique, and to make efforts to transform the results of peripheral nerve research into clinical practice.

A novel mutation in the conserved sequence of vascular endothelial growth factor receptor 3 leads to primary lymphoedema

Objective

To investigate whether lymphoedema in a Chinese family showed the hereditary and clinical characteristics of Milroy disease, an autosomal dominant form of congenital lymphoedema, typically characterized by chronic lower limb tissue swelling due to abnormal lymphatic vasculature development, and to perform mutational analyses of vascular endothelial growth factor receptor (VEGFR)3.

Methods

Individuals from a three-generation family affected by congenital lymphoedema were clinically assessed for Milroy disease. Mutation analysis of VEGFR3 was performed using DNA from family members and healthy controls.

Results

Out of 20 family members, eight were diagnosed with hereditary lymphoedema. Mutation analyses revealed a novel mutation site for c.3163 G>A, resulting in a p.1055D>N mutation in the second tyrosine kinase domain of VEGFR3, which was present in affected individuals only (absent in all unaffected family members and 130 healthy controls). Computed functional analyses showed the mutation may lead to structural alterations with a probability of 0.99999 of being disease causing.

Conclusion

A novel mutation associated with Milroy disease was identified in a Chinese family, expanding our knowledge of VEGFR3 gene function and providing a potential molecular target for treating hereditary lymphoedema.

Ureteral tunnel length versus ureteral orifice configuration in the determination of ureterovesical junction competence: A computer simulation model

INTRODUCTION

The long-held belief that a ureteral re-implant tunnel should be five times the diameter of the ureter, as proposed by Paquin in 1959, ignores the effect of the orifice on the occurrence of reflux. In 1969, Lyon proposed that the shape of the ureteral orifice (UO) is more important than the intravesical tunnel. However, both theories missed quantitative evidence from principles of physics. The goal of the current study was to test Lyon's theory through numerical models (i.e. to quantify the sensitivity of ureterovesical junction (UVJ) competence to intravesical tunnel length and to the UO).

MATERIALS AND METHODS

The closure of a three-dimensional spatial configuration of ureter, constrained within a bladder, was simulated. Two common UO shapes (i.e. golf type vs 2-mm volcano type (Summary Fig.)), and two different intravesical ureteral tunnel length/diameter ratios (3:1 and 5:1) were examined. The required closure pressures were then compared.

RESULTS

The UO was a significant factor in determining closure pressure. Given the same intravesical ureteral tunnel length/diameter ratio, the required closure pressure for the volcanic orifice was 78% less than that for the golf orifice. On the other hand, the intravesical ureteral tunnel length/diameter ratio had minimal effect on the required closure pressure. As the intravesical ureteral tunnel length/diameter ratio changed from 3:1 to 5:1, the required closure pressure was reduced by less than 7%, regardless of the orifice shape.

CONCLUSIONS

The simulation results showed that UVJ competence was more sensitive to a 2-mm protrusion of the UO compared to an increase in the intravesical tunnel length from 3:1 to 5:1. This agrees with Lyon's theory, and at the same time challenges Paquin's 5:1 rule. Researchers could use this information to consider the UO configuration in further animal, human, computer or material models.

Identification of a 5‑lncRNA signature‑based risk scoring system for survival prediction in colorectal cancer

The present study aimed to investigate potential prognostic long noncoding RNAs (lncRNAs) associated with colorectal cancer (CRC). An mRNA‑seq dataset obtained from The Cancer Genome Atlas was employed to identify the differentially expressed lncRNAs (DELs) between CRC patients with good and poor prognoses. Subsequently, univariate and multivariate Cox regression analyses were conducted to analyze the prognosis‑associated lncRNAs among all DELs. In addition, a risk scoring system was developed according to the expression levels of the prognostic lncRNAs, which was then applied to a training set and an independent testing set. Furthermore, the co‑expressed genes of prognostic lncRNAs were screened using a Multi‑Experiment Matrix online tool for construction of lncRNA‑gene networks. Finally, Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology (GO) function enrichment analyses were performed on genes in the lncRNA‑gene networks using KOBAS, GOATOOLS and ClusterProfiler. The present study identified 82 DELs, of which long intergenic nonprotein coding RNA 2159, RP11‑452L6.6, RP11‑894P9.1 and RP11‑69M1.6, and whey acidic protein four‑disulfide core domain 21 (WFDC21P) were reported to be independently associated with the prognosis of patients with CRC. A 5‑lncRNA signature‑based risk scoring system was developed, which may be used to classify patients into low‑ and high‑risk groups with significantly different recurrence‑free survival times in the training and testing sets (P<0.05). Co‑expressed genes of WFDC21P or RP11‑69M1.6 were utilized to construct the lncRNA‑gene networks. Genes in the networks were significantly enriched in 'tight junction', 'focal adhesion' and 'regulation of actin cytoskeleton' pathways, and numerous GO terms associated with 'reactive oxygen species metabolism' and 'nitric oxide metabolism'. The present study proposed a 5‑lncRNA signature‑based risk scoring system for predicting the prognosis of patients with CRC, and revealed the associated signaling pathways and biological processes. The results of the present study may help improve prognostic evaluation in clinical practice.

OCO-2 advances photosynthesis observation from space via solar-induced chlorophyll fluorescence

Quantifying gross primary production (GPP) remains a major challenge in global carbon cycle research. Spaceborne monitoring of solar-induced chlorophyll fluorescence (SIF), an integrative photosynthetic signal of molecular origin, can assist in terrestrial GPP monitoring. However, the extent to which SIF tracks spatiotemporal variations in GPP remains unresolved. Orbiting Carbon Observatory-2 (OCO-2)'s SIF data acquisition and fine spatial resolution permit direct validation against ground and airborne observations. Empirical orthogonal function analysis shows consistent spatiotemporal correspondence between OCO-2 SIF and GPP globally. A linear SIF-GPP relationship is also obtained at eddy-flux sites covering diverse biomes, setting the stage for future investigations of the robustness of such a relationship across more biomes. Our findings support the central importance of high-quality satellite SIF for studying terrestrial carbon cycle dynamics.

Comparative pharmacokinetics study of anastrozole after single administration and combination with celecoxib

1. There are numerous investigations demonstrating that the cyclooxygenase-2 (COX-2) inhibitors might enhance the efficiency of anastrozole in breast cancer. Hence, this study was conducted to investigate the comparative pharmacokinetics of anastrozole after single administration and combination with celecoxib. 2. A simple protein precipitation procedure was adopted for the sample preparation with satisfactory extraction recovery for both anastrozole and the internal standard, and then anastrozole was separated and analysed on an ACQUITY BEH UPLC C₁₈ column (50 × 2.0 mm, 1.7 μm, Waters) within 2 min. The calibration curves showed good linarites (r = 0.994). Intra- and inter-day precision were within 4.93 and 13.83%, respectively. The mean extraction recoveries across QC levels were within 91.4%, and the matrix effects were within 94.5%. 3. Results showed that the method was reliable to determine anastrozole in rat plasma. Compared with rats in single administration group, no significant difference was found in the combination group. It is workable to use celecoxib combined with anastrozole in clinical therapy.

Genome-wide association analysis identifies potential regulatory genes for eumelanin pigmentation in chicken plumage

Plumage color in chicken is determined by the proportion of eumelanin and pheomelanin pigmentation. As the main ingredient in plumage melanin, eumelanin plays a key role in the dark black, brown and grey coloration. However, very few studies have been performed to identify the related genes and mutations on a genome-wide scale. Herein, a resource family consisting of one backcross population and two F2 cross populations between a black roster and Yukou Brown I parent stockbreed was constructed for identification of genes related to eumelanin pigmentation. Chickens with eumelanin in their plumage were classified as the case group, and the rest were considered the control group. A genome-wide association study of this phenotype and genotypes using Affymetrix 600K HD SNP arrays in this F2 family revealed 13 significantly associated SNPs and in 10 separate genes on chromosomes 1, 2, 3 and 5. Based on previous studies in model species, we inferred that genes, including NUAK family kinase 1 (NUAK1) and sonic hedgehog (SHH), may play roles in the development of neural crest cells or melanoblasts during the embryonic period, which may also affect the eumelanin pigmentation. Our results facilitate the understanding of the genetic basis of eumelanin pigmentation in chicken plumage.

Iodine and freeze-drying enhanced high-resolution MicroCT imaging for reconstructing 3D intraneural topography of human peripheral nerve fascicles

BACKGROUND

The precise annotation and accurate identification of the topography of fascicles to the end organs are prerequisites for studying human peripheral nerves.

NEW METHOD

In this study, we present a feasible imaging method that acquires 3D high-resolution (HR) topography of peripheral nerve fascicles using an iodine and freeze-drying (IFD) micro-computed tomography (microCT) method to greatly increase the contrast of fascicle images.

RESULTS

The enhanced microCT imaging method can facilitate the reconstruction of high-contrast HR fascicle images, fascicle segmentation and extraction, feature analysis, and the tracing of fascicle topography to end organs, which define fascicle functions.

COMPARISON WITH EXISTING METHODS

The complex intraneural aggregation and distribution of fascicles is typically assessed using histological techniques or MR imaging to acquire coarse axial three-dimensional (3D) maps. However, the disadvantages of histological techniques (static, axial manual registration, and data instability) and MR imaging (low-resolution) limit these applications in reconstructing the topography of nerve fascicles.

CONCLUSIONS

Thus, enhanced microCT is a new technique for acquiring 3D intraneural topography of the human peripheral nerve fascicles both to improve our understanding of neurobiological principles and to guide accurate repair in the clinic. Additionally, 3D microstructure data can be used as a biofabrication model, which in turn can be used to fabricate scaffolds to repair long nerve gaps.

The Effect of Apolipoprotein E ɛ4 (APOE E4) on Visuospatial Working Memory in Healthy Elders and Amnestic Mild Cognitive Impairment Patients: An Event-related Potentials Study

Introduction

Previous studies provided inconsistent evidences for the effect of apolipoprotein E ɛ4 (APOE ɛ4) status on the visuospatial working memory (VSWM). Our study was the first investigation with event-related potential (ERP) to explore the effect of APOE ɛ4 on VSWM in healthy elders and aMCI patients.

Objective

The aim was to investigate the effect of APOE ɛ4 on VSWM with event-related potential (ERP) study in healthy elders and aMCI patients.

Methods

Thirty-nine aMCI patients (27 APOE ɛ4 non-carriers and 12 APOE ɛ4 carriers) and 43 their matched control (25 APOE ɛ4 non-carriers and 18 APOE ɛ4 carriers) performed an N-back task, a VSWM paradigm that manipulated the number of items to be stored in memory.

Results

Our study detected reduced accuracy and delayed mean correct response time in aMCI patients than healthy elders. P300 was elicited by VSWM and its amplitude was lower in aMCI patients at the central-parietal and parietal electrodes than healthy controls. In healthy elders, P300 amplitude declined prior to task performance change in APOE ɛ4 carriers than non-carriers. Regarding aMCI patients, P300 amplitude result revealed exacerbated VSWM deficits in APOE ɛ4 carriers than APOE ɛ4 non-carriers. Additionally, standardized low-resolution brain electromagnetic tomography analysis (s-LORETA) result showed enhanced brain activation in right parahippocampal gyrus during P300 time range in APOE ɛ4 carriers than non-carriers in aMCI patients (Fig. 1, Tables 1 and 2).

Conclusions

It demonstrated that P300 amplitude might serve as a biomarker for recognizing aMCI patients and contribute to early detection of worse VSWM in APOE ɛ4 carriers than non-carriers.

Disclosure of interest

The author has not supplied his/her declaration of competing interest.

Investigation of the protective effect of Paeonia lactiflora on Semen Strychni-induced neurotoxicity based on monitoring nine potential neurotoxicity biomarkers in rat serum and brain tissue

Semen Strychni has been widely used as a traditional Chinese herb medicine, but its clinical use was limited for its potential neurotoxicity and nephrotoxicity. This study aimed to investigate S. Strychni-induced neurotoxicity and the neuro-protective effect of Paeonia lactiflora based on monitoring nine potential neurotoxicity biomarkers in rat serum and brain tissue. A sensitive liquid chromatography-tandem mass spectrometry method was developed and validated to monitor serotonin, tryptophan, dopamine, tyrosine and glutamate in serum and five brain regions (prefrontal cortex, hippocampus, striatum, cerebellum and hypothalamus). Analytes were separated on a CAPCELL CORE PC column (150 mm × 2 mm, 2.7 μm) with a gradient program of acetonitrile-water (0.2 % formic acid) and a total runtime of 7.5 min. In addition, enzyme-linked immunosorbent assay was conducted to determine four kinds of protein (tryptophan hydroxylase, tyrosine hydroxylase, endogenous brain-derived neurotrophic factor and nerve growth factor). Results demonstrated that the administration of S. Strychni could cause certain endogenous substances disorder. These analytes were found significantly changed (p < 0.05) in serum (except glutamate) and in certain tested brain regions in S. Strychni extract group. Pretreatment of P. lactiflora could significantly reverse the S. Strychni-induced neurotoxicity and normalize the levels of such endogenous substances. The study could be further used in predicting and monitoring neurotoxicity caused by other reasons, and it was expected to be useful for improving clinical use of S. Strychni through pretreatment with P. lactiflora.