Diagnosis of poorly differentiated adenocarcinoma of the stomach by confocal laser endomicroscopy:A case report

BACKGROUND In recent years,confocal laser endomicroscopy(CLE)has become a new endoscopic imaging technology at the microscopic level,which is extensively performed for real-time in vivo histological examination.CLE can be performed to distinguish benign from malignant lesions.In this study,we diagnosed using CLE an asymptomatic patient with poorly differentiated gastric adenocarcinoma.CASE SUMMARY A 63-year-old woman was diagnosed with gastric mucosal lesions,which may be gastric cancer,in the small curvature of the stomach by gastroscopy.She consented to undergo CLE for morphological observation of the gastric mucosa.Through the combination of CLE diagnosis and postoperative pathology,the intraoperative CLE diagnosis was considered to be reliable.According to our experience,CLE can be performed as the first choice for the diagnosis of gastric cancer.CONCLUSION CLE has several advantages over pathological diagnosis.We believe that CLE has great potential in the diagnosis of benign and malignant gastric lesions.

In situ observation of the dissolution kinetics of Al_(2)O_(3) particles in CaO–Al_(2)O_(3)–SiO_(2) slags using laser confocal scanning microscopy

The dissolution kinetics of Al_(2)O_(3) in CaO-Al_(2)O_(3) SiOslags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 K.The results show that the controlling step during the Al_(2)O_(3) dissolution was the diffusionin molten slag.It was found that the dissolution curves of Al_(2)O_(3) particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al_(2)O_(3) ratio of slag.A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al_(2)O_(3) in slag.Diffusion coefficients of Al_(2)O_(3) in slag were calculated as 2.8×10to 4.1×10m~2/s at the temperature of 1773-1873 K.The dissolution rate of Al_(2)O_(3) increased with higher temperature,CaO/Al_(2)O_(3),and particle size.A new model was shown to be v_(Al_(2)O_(3))=0.16×r_(0)^(1.58)×x^(3.52)×(T-T_(mp))^(1.11)to predict the dissolution rate and the total dissolution time of Al_(2)O_(3) inclusions with various sizes,where vAl_(2)O_(3) is the dissolution rate of Al_(2)O_(3) in volume,μm^(3)/s;x is the value of CaO/Al_(2)O_(3) mass ratio;R_(0) is the initial radius of Al_(2)O_(3),μm;T is the temperature,K;T_(mp) is the melting point of slag,K.

Confocal Laser Endomicroscopy in the Field of Esophageal Diseases

Confocal laser endomicroscopy (CLE) is a new endoscopic imaging technology that allows real-time, high-resolution observation of tomographic images of mucosal cells and subcellular levels in vivo, detecting microscopic structural changes in mucosal morphology, and its in vivo immediate pathological diagnostic capability can avoid delays in mucosal pathological diagnosis and reduce the pain caused by repeated biopsies. CLE is known as “optical biopsy” and compared with other endoscopic techniques, it has obvious advantages. CLE systems include probe-based confocal laser endomicroscopy (pCLE) and endoscope-based confocal laser endomicroscopy (eCLE). Since 2006, CLE has been widely used for the evaluation of various lesions in the digestive system, including esophageal, gastric, and colonic neoplasia, pancreatic cysts and solid lesions, and inflammatory bowel disease. The advent of CLE has made in vivo microscopic imaging possible, which has changed the endoscopic screening and diagnosis of multiple gastrointestinal (GI) lesions. However, the value of its use in GI diseases is still controversial. In this review, we focus on the application of CLE in the field of esophageal diseases.

Classification of histological severity of Helicobacter pylori-associated gastritis by confocal laser endomicroscopy

AIM: To classify the histological severity of Helicobacter pylori (H. pylori) infection-associated gastritis by confocal laser endomicroscopy (CLE). METHODS: Patients with upper gastrointestinal symptoms or individuals who were screened for gastric cancer were enrolled in this study. Histological severity of H. pylori infection-associated gastritis was graded according to the established CLE criteria. Diagnostic value of CLE for histo-logical gastritis was investigated and compared with that of white light endoscopy (WLE). Targeted biopsies from the sites observed by CLE were performed. RESULTS: A total of 118 consecutive patients with H. pylori infection-associated gastritis were enrolled in this study. Receiver operating characteristic curve analysis showedthat the sensitivity and specifi city of CLE were 82.9% and 90.9% for the diagnosis of H. pylori infection, 94.6% and 97.4% for predicting gastric normal mucosa, 98.5% and 94.6% for predicting histological active inflammation, 92.9% and 95.2% for predicting glan-dular atrophy, 98.6% and 100% for diagnosing intes-tinal metaplasia, respectively. Post-CLE image analysis showed that goblet cells and absorptive cells were the two most common parameters on the CLE-diagnosed intestinal metaplasia (IM) images (P < 0.001). More his-tological lesions of the stomach could be found by CLE than by WLE (P < 0.001). CONCLUSION: CLE can accurately show the histological severity of H. pylori infection-associated gastritis. Mapping IM by CLE has a rather good diagnostic accuracy.

Role of digital chromoendoscopy and confocal laser endomicroscopy for gastric intestinal metaplasia and cancer surveillance

In Japan and countries such as South Korea and Tai-wan, China, the standard technique for detecting earlygastric cancer (EGC) is chromoendoscopy. This technique involves a magnified endoscope and the use ofan indigo-carmine spray to distinguish between EGCand non-EGC areas. However, this technique is notwidely adopted in many parts of the world. One important reason for limited use is that this technique needsan experienced endoscopist to interpret the imagesduring the procedure. In addition, the sensitivity for detecting gastric intestinal metaplasia (GIM), a precancerous lesion of EGC, is graded as suboptimal. Moreover,the requirement of a cumbersome spraying method isinconvenient and needs preparation time. Easier digitalchromoendoscopy techniques, such as Narrow-bandImaging and Flexible spectral Imaging Color Enhancement, have been reported to facilitate targeted GIM and EGC biopsy. They provide higher sensitivities over conventional white light endoscopy. Recently, the noveltechnology of confocal laser endomicroscopy has been introduced as a high-magnification (1000 ×) real-time evaluation for many early gastrointestinal (GI) cancersand precancerous GI lesions, including colonic polyp,Barrett's esophagus, and GIM. The advantage of this technique is that it can be used as an in vivo confirmation of the presence of GIM and EGC during endoscopic surveillance. This review aims to explain the current information on the usefulness of digital chromoendos-copy and confocal laser endomicroscopy for evaluating GIM and EGC during endoscopic surveillance and the possible future role of these techniques for GI cancerscreening programs.

Three-dimensional image of hepatocellular carcinoma under confocal laser scanning microscope

AIM To investigate the application of confocallaser scanning microscopy(CLSM)in tumorpathology and three-dimensional( 3-D )reconstruction by CLSM in pathologic specimensof hepatocellular carcinoma(HCC).METHODS The 30μm thick sections were cutfrom the paraffin-embedded tissues of HCC,hyperplasia and normal liver,stained with DNAfluorescent probe YOYO-1 iodide and examinedby CLSM to collect optical sections of nuclei and3-D images reconstructed.RESULTS HCC displayed chaotic arrangementof carcinoma cell nuclei,marked pleomorphism,indented and irregular nuclear surface,andirregular and coarse chromatin texture.CONCLUSION The serial optical tomograms ofCLSM can be used to create 3-D reconstruction ofcancer cell nuclei.Such 3-D impressions mightbe helpful or even essential in making anaccurate diagnosis.

Probe based confocal laser endomicroscopy of the pancreatobiliary system

AIM:To review applications of confocal laser endomicroscopy(CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to p CLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and crossreferencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies.R E S U LT S : In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of(98% vs 45%) andhas a negative predictive value(97% vs 69%), but decreased the specificity(67% vs 100%) and the positive predictive value(71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of p CLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of p CLE in the evaluation of pancreatobiliary disorders might be better suited for those with an intermediate and low probability.

Real time detection of antibody-antigen interaction using a laser scanning confocal imaging-surface plasmon resonance system

A laser scanning confocal imaging-surface plasmon resonance （LSCI-SPR） instrument integrated with a wavelength-dependent surface plasmon resonance （SPR） sensor and a laser scanning confocal microscopy （LSCM） is built to detect the bonding process of human IgG and fluorescent-labeled affinity purified antibodies in real time. The shifts of resonant wavelength at different reaction time stages are obtained by SPR, corresponding well with the changes of the fluorescence intensity collected by using LSCM. The instrument shows the merits of the combination and complementation of the SPR and LSCM, with such advantages as quantificational analysis, high spatial resolution and real time monitor, which are of great importance for practical applications in biosensor and life science.

Molecular confocal laser endomicroscopy:A novel technique for in vivo cellular characterization of gastrointestinal lesions

While flexible endoscopy is essential for macroscopic evaluation,confocal laser endomicroscopy(CLE)has recently emerged as an endoscopic method enabling visualization at a cellular level.Two systems are currently available,one based on miniprobes that can be inserted via a conventional endoscope or via a needle guided by endoscopic ultrasound.The second system has a confocal microscope integrated into the distal part of an endoscope.By adding molecular probes like fluorescein conjugated antibodies or fluorescent peptides to this procedure(either topically or systemically administered during on-going endoscopy),a novel world of molecular evaluation opens up.The method of molecular CLE could potentially be used for estimating the expression of important receptors in carcinomas,subsequently resulting in immediate individualization of treatment regimens,but also for improving the diagnostic accuracy of endoscopic procedures by identifying otherwise invisible mucosal lesions.Furthermore,studies have shown that fluorescein labelled drugs can be used to estimate the affinity of the drug to a target organ,which probably can be correlated to the efficacy of the drug.However,several of the studies in this research field have been conducted in animal facilities or in vitro,while only a limited number of trials have actually been carried out in vivo.Therefore,safety issues still needs further evaluations.This review will present an overview of the implications and pitfalls,as well as future challenges of molecular CLE in gastrointestinal diseases.

Confocal laser endomicroscopy distinguishing benign and malignant gallbladder polyps during choledochoscopic gallbladderpreserving polypectomy:A case report

BACKGROUND In the last decade, confocal laser endomicroscopy (CLE) has emerged as a newendoscopic imaging modality for real-time in vivo histological examination at themicroscopic level. CLE has been shown to be useful for distinguishing benign andmalignant lesions and has been widely used in many digestive diseases. In ourstudy, we used CLE for the first time to examine the morphology of cholesterolpolyps as well as the different parts of normal gallbladder mucosa.CASE SUMMARY A 57-year-old woman was diagnosed by ultrasound with a polyp of 21 mm in thegallbladder wall. She consented to polyp removal by laparoscopic choledochoscopy.During laparoscopic cholecystectomy combined with choledochoscopicpolyp resection, CLE was used to observe the morphology of the polyp surfacecells. The appearance of the mucosa and microvessels in various parts of thegallbladder were also observed under CLE. Through comparison betweenpostoperative pathology and intraoperative CLE diagnosis, the reliability ofintraoperative CLE diagnosis was confirmed. CLE is a reliable method to examineliving cell pathology during cholecystectomy. Based on our practice, CLE shouldbe prioritized in the diagnosis of gallbladder polyps.CONCLUSION Compared with traditional histological examination, CLE has several advantages.We believe that CLE has great potential in this field.

Confocal Laser Scanning Microscope Evaluation of Early Bacterial Colonization on Zirconium Oxide and Titanium Surfaces:An in vivo Study

To investigate the bacterial colonization on zirconium oxide and titanium surfaces in vivo quantitatively using a confocal laser scanning microscope （CLSM）. Ten samples of zirconium oxide ceramic and commercially pure titanium were fabricated and polished using silicon carbide abrasive paper. One sample from each group was evaluated topographic pattern under a scanning electron microscope. One sample from each group was to evaluate roughness using a profilometer. Eight volunteers were selected. The samples were cemented at the buccal surfaces of upper first molars. All samples were removed after 48 hours, immersed in SYTO-9 and propidium iodide fluorescent to stain for adherent bacteria and obseIved with CLSM. Fewer bacteria were observed in zirconia group than titanium group. However, there was no statistical difference between two groups. The experimental results demonstrate that zirconium oxide may be considered as a promising material for dental implant abutments.

Confocal laser endomicroscopy and immunoendoscopy for real-time assessment of vascularization in gastrointestinal malignancies

Gastrointestinal cancers represent a major cause of morbidity and mortality,with incomplete response to chemotherapy in the advanced stages and poor prognosis.Angiogenesis plays a crucial part in tumor growth and metastasis,with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network.Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents.Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination(immunoendoscopy),as a future challenge,will add functional analysis to the morphological aspect of the neoplastic process.This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization,resulting in a broad spectrum of potential clinical applications,and also preclinical research that could be translated to human studies.

Clinical impact of confocal laser endomicroscopy in the management of gastrointestinal lesions with an uncertain diagnosis

AIM To evaluate the clinical impact of confocal laser endomicroscopy(CLE) in the diagnosis and management of patients with an uncertain diagnosis.METHODS A retrospective chart review was performed.Patients who underwent CLE between November 2013 and October 2015 and exhibited a poor correlation between endoscopic and histological findings were included.Baseline characteristics,indications,previous diagnostic studies,findings at the time of CLE,clinical management and histological results were analyzed.Interventions based on CLE findings were also analyzed.We compared the diagnostic accuracy of CLE and target biopsies of surgical specimens.RESULTS A total of 144 patients were included.Of these,51%(74/144) were female.The mean age was 51 years old.In all,41/144(28.4%) lesions were neoplastic(13 bile duct,10 gastric,8 esophageal,6 colonic,1 duodenal,1 rectal,1 ampulloma and 1 pancreatic).The sensitivity,specificity,positive predictive value,negative predictive value,and observed agreement when CLE was used to detect N-lesions were 85.37%,87.38%,72.92%,93.75% and 86.81%,respectively.Cohen's Kappa was 69.20%,thus indicating good agreement.Changes in management were observed in 54% of the cases.CONCLUSION CLE is a new diagnostic tool that has a significant clinical impact on the diagnosis and treatment of patients with uncertain diagnosis.

In-vivo characterization of DALM in ulcerative colitis with high-resolution probe-based confocal laser endomicroscopy

Recently,the use of confocal laser endomicroscopy(CLE) in the diagnosis of chronic ulcerative colitis(CUC) was reported.In this brief report we aimed to assess the application of probe-based CLE to characterize colonic mucosa and dysplasia in CUC.The study involved a patient presenting long-standing CUC.Confocal imaging of both the inflamed mucosa,a circumscribed lesion(dysplasiaassociated lesional mass),and adjacent colonic mucosa are demonstrated and the correlation between the CLE and histological images.Inflamed mucosa and dysplasia showed specific alteration of crypt architecture,cellular infiltration,and vessel architecture with an excellent correlation between CLE and standard histological examination.

Diagnosis of gastric intraepithelial neoplasia by narrow-band imaging and confocal laser endomicroscopy

AIM:To evaluate the diagnosis of different differentiated gastric intraepithelial neoplasia (IN) by magnifica-tion endoscopy combined with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE). METHODS:Eligible patients with suspected gastric IN lesions previously diagnosed by endoscopy in secondary hospitals and scheduled for further diagnosis and tratment were recruited for this study. Excluded from the study were patients who had liver cirrhosis, impaired renal function, acute gastrointestinal (GI) bleeding, coagulopathy, esophageal varices, jaundice, and GI post-surgery. Also excluded were those who were pregnant, breastfeeding, were younger than 18 years old, or were unable to provide informed consent. All patients had all mucus and bile cleared from their stom-achs. They then received upper GI endoscopy. When a mucosal lesion is found during observation with whitelight imaging, the lesion is visualized using maximal magnification, employing gradual movement of the tip of the endoscope to bring the image into focus. Saved images are analyzed. Confocal images were evaluated by two endoscopists (Huang J and Li MY), who were familiar with CLE, blinded to the related information about the lesions, and asked to classify each lesion as either a low grade dysplasia (LGD) or high grade dysplasia (HGD) according to given criteria. The results were compared with the final histopathologic diagnosis. ME-NBI images were evaluated by two endoscopists (Lu ZS and Ling-Hu EQ) who were familiar with NBI, blinded to the related information about the lesions and CLE images, and were asked to classify each lesion as a LGD or HGD according to the "microvascular pattern and surface pattern" classification system. The results were compared with the final histopathologic diagnosis. RESULTS: The study included 32 pathology-proven low grade gastric IN and 26 pathology-proven high grade gastric IN that were detected with any of the modalities. CLE and ME-NBI enabled clear visualization of the vascular microsurface patterns and microvascular structures of the gastric mucosa. The accuracy of the CLE and the ME-NBI diagnosis was 88% (95% CI:78%-98%) and 81% (95% CI: 69%-93%), respectively. The kappa coefficient of agreement between the histopathology and the in vivo CLE imaging was 0.755; between the histopathology and the in vivo CLE imaging was 0.615. McNemar's test (binomial distribution used) indicated that the agreement was significant (P < 0.05). When patients were diagnosed by MENBI with CLE, the overall accuracy of the diagnosis was 86.21% (95% CI:73%-96%), and the kappa coefficient of agreement was 0.713, according to McNemar's test (P < 0.05). CONCLUSION:Higher diagnostic accuracy, sensitivityand specificity of CLE over ME-NBI indicate the feasibility of these two techniques for the efficacious diagnostic classification of gastric IN.

Visualization of Golgia apparatus as an intracellular calcium store by laser scanning confocal microscope

Using laser scanning confocal microscopy, we have found that the in cells loaded with fluo-3/AM, highest intracellular Ca(2+) in the perinuclear region is associated with the Golgi apparatus. The spatiotemporal subcellu lar distribution of Ca(2+) in living human fibroblasts exposing to calcium-free medium in response to agonists has been investigated. PDGF, which releases Ca(2+) from intracellular stores by inositol(1, 4, 5)-trisphosphate pathway,produced a biphasic transient rise in intracellular calcium.The initial rise was resulted from a direct release of calcium from the Golgi apparatus. Calcium could be also released from and reaccumulated into the Golgi apparatus by the stimulation of thapsigargin, an inhibitor of the Ca(2+) transport ATPase of intracellular calcium store. Permeablizing the plasma membrane by 10 μM digitonin resulted in the calcium release from the Golgi apparatus and depletion of the internal calcium store. These results suggest that the Golgi apparatus plays a role in Ca(2+) regulation in signal transduction.

Appraisal of needle-based confocal laser endomicroscopy inthe diagnosis of pancreatic cysts

Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Eventhough most of these are incidental findings, it remains very concerning for both patients and treating clinicians. Differentiating and predicting malignant transformation in pancreatic cystic lesions is clinically challenging. Current evaluation of suspicious cystic lesions includes a combination of radiologic imaging, endoscopic ultrasound(EUS) and cyst fluid analyses. Despite these attempts, precise diagnostic stratification among nonmucinous, mucinous, and malignant cystic lesions is often not possible until surgical resection. EUS-guided needle based confocal laser endomicroscopy(n CLE) for evaluation of pancreatic cysts is emerging as a powerful technique with remarkable potential. Though limited imaging data from 3 large clinical trials(INSPECT, DETECT and CONTACT) are currently the reference standard for n CLE imaging, nonetheless these have not been validated in large studies. The aim of this review article is to review the evolving role of EUS-guided n CLE in management of pancreatic cystic lesions in terms of its significance, adverse events, limitations, and implications.

Confocal laser endomicroscopy in inflammatory bowel diseases:Dream or reality?

Confocal laser endomicroscopy(CLE)is a newly introduced procedure that provide real-time,high-resolution imaging of the gastrointestinal mucosa during endoscopy,allowing the visualization of the pathology of the mucosal epithelium with its cellular and subcellular structures.Recently,the use of CLE was reported in the study of colonic mucosa in patients with inflammatory bowel diseases and in particular in patients affected by ulcerative colitis.CLE has the potential to have an important role in management of inflammatory bowel diseases(IBD)patients as it can be used to assess the grading of colitis and in detection of microscopic colitis in endoscopically silent segments.Moreover,CLE can be used in surveillance programs especially in highrisk patients.Finally,CLE has been effectively used in diagnosing a biliary dysplasia/neoplasia in patients with primary sclerosing cholangitis,a pathological condition frequently associated with IBD,with a coexisting bile duct stricture.

Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probebased confocal laser endomicroscopy of the normal stomach

Probe-based confocal laser endomicroscopy(p CLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. p CLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pC LE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein.

Neuroprotective effects of low-concentration alpha-tocopherol Confocal laser microscopy observations

BACKGROUND： Alpha-tocopherol （ α-tocopherol） can effectively relieve neuronal damage induced by oxygen-centered free radicals. However, the effective dose remains controversial. OBJECTIVE： To evaluate the protective effects of low-concentration α-tocopherol on neuronal membranes. DESIGN, TIME AND SETTING： Contrast observation and in vitro study, performed at Laboratory of Neurosurgery, Tianjin Huanhu Hospital between April and September 2006. MATERIALS： Fetal cortical neurons were derived from two 14-day pregnant SD rats, and α-tocopherol was provided by Sigma, USA. METHODS： The neurons were randomly assigned to six groups： （1） normal： neurons were cultured under normal conditions; （2） oxidative damage： oxidative free radicals was damaged using the Fenton reaction; （3） α-tocopherol： neurons were cultured in different concentrations of -tocopherol 10, 20, 40, and 80 mg/L for 2 hours, respectively. MAIN OUTCOME MEASURES： Neuronal membrane damage was observed using a confocal laser microscope, and malonaldehyde production was detected using the thiobarbituric acid method. RESULTS： At normal, biological concentrations （10 mg/L）, α-tocopherol induced no change in the damaged neurons （P 〉 0.05）. However, at a concentration of 80 mg/L, the number of damaged neurons was significantly reduced, compared with the damage group （P 〈 0.05）. Malonaldehyde levels following 80 mg/L α-tocopherol treatment were less than the oxygen free radical damage group （P 〈 0.05）, but greater than the control group （P 〈 0.01）. CONCLUSION： A concentration of 80 mg/L α-tocopherol can effectively protect the neuronal cell membrane from oxidative damage