Confocal laser endomicroscopy as a new diagnostic tool for poorly differentiated gastric adenocarcinoma

Gastric cancer(GC)is a multifactorial disease,where both environmental and genetic features can have an impact on its occurrence and development.GC represents one of the leading causes of cancer-related deaths worldwide.GC is most frequent in males and is believed to arise from a series of premalignant lesions.The detection of GC at an early stage is crucial because early GC,which is an invasive stomach cancer confined to the mucosal or submucosal lining,may be curable with a reported 5-year survival rate of more than 90%.Advanced GC usually has a poor prognosis despite current treatment standards.The diagnostic efficacy of conventional endoscopy(with light endoscopy)is currently limited.Confocal laser endomicroscopy is a novel imaging technique that allows real-time in vivo histological examination of mucosal surfaces during endoscopy.Confocal laser endomicroscopy may be of great importance in the surveillance of precancerous gastric lesions and in the diagnosis of GC.In this editorial we commented on the article about this topic published by Lou et al in the recent issue of the World Journal of Clinical Cases.

Corneal nerve changes by anti-glaucoma medications examined by in vivo confocal microscopy

AIM:To evaluate the effects of antiglaucoma eye drops on corneal nerves by in vivo confocal microscopy(IVCM).METHODS:This study comprised 79 patients diagnosed with glaucoma and 16 healthy control individuals.Among the glaucoma patients,54 were treated with medication,while 25 remained untreated.Central corneal images were evaluated by IVCM,and then ACCMetrics was used to calculate the following parameters:corneal nerve fiber density(CNFD),branch density(CNBD),fiber length(CNFL),total branch density(CTBD),fiber area(CNFA),fiber width(CNFW),and fractal dimension(CNFrD).The correlation between IVCM parameters and drugs was evaluated using non-parametric measurements of Spearman’s rank correlation coefficient.RESULTS:The CNFD was reduced in glaucoma groups compared to healthy subjects(P<0.01).Patients using anti-glaucoma medications exhibited poorer confocal parameters compared to untreated patients.As the number of medications and usage count increased,CNFD,CNBD,CNFL,CTBD,CNFA,and CNFrD experienced a decline,while CNFW increased(all P<0.01).For the brinzolamide-therapy group,there was a significant decrease in CNFD and CNFL compared to the other monotherapy groups(P<0.001).In the absence of medication,CNFD in males was lower than that in females(P<0.05).Among patients under medication therapy,CNFD remained consistent between males and females.CONCLUSION:Antiglaucoma eye drops affect the microstructure of corneal nerves.IVCM and ACCMetrics are useful tools that could be used to evaluate the corneal nerve changes.

Advanced optical microscopy methods for in vivo imaging of sub-cellular structures in thick biological tissuesl

Optical microscopy has become an indispensable tool for visualizing sub-cellular structures andbiological processes.However,scattering in biological tissues is a major obstacle that preventshigh-resolution images from being obtained from deep regions of tissue.We review commontechniques,such as multiphoton microscopy(MPM)and optical coherence microscopy(OCM),for diffraction limited imaging beyond an imaging depth of 0.5 mm.Novel implementations havebeen emerging in recent years giving higher imaging speed,deeper penetration,and better imagequality.Focal modulation microscopy(FMM)is a novel method that combines confocal spatialfltering with focal modulation to reject out-of-focus background.FMM has demonstrated animaging depth comparable to those of MPM and OCM,near-real-time image acquisition,and thecapability for multiple contrast mechanisms.

Revealing the F_actin Networks in Interphase Nuclei of Garlic Clove Cells by Confocal Fluorescence Microscopy

The interphase nuclei of parenchyma cells and epidermal cells of garlic ( Allium sativum L.) clove were labelled with rabbit anti_actin antibody and FITC_conjugated goat anti_rabbit IgG antibody. The authors observed results with fluorescence microscopy and confocal laser scanning microscopy. The nuclei showed prominent green_yellow fluorescence, indicating the presence of actin in the nuclei. Fluorescence examination with TRITC_phalloidin showed distinctive red fluorescence in the nuclei, indicating that F_actin is present in the nuclei. Confocal laser scanning microscopy indicated the presence of F_actin containing network structures in the nuclei, but the network structures were absent and the nuclei still showed red fluorescence when the cells were treated with cytochalasin D before fixation; the red fluorescence in the nuclei was hard to be observed when the cells were treated with unlabelled phalloidin before the cells were stained with TRITC_phalloidin. These results indicate that F_actin is in the nuclei and forms network structures in the nuclei of garlic cells.

In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy

AIM： To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents. METHODS： A novel rigid confocal probe （diameter 7 mm） was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation, Light emission was detected at 505 to 750 nm. The field of view was 475 μm × 475 μm. Optical slice thickness was 7 μm with a lateral resolution of 0.7 μm. Subsurface serial images at different depths （surface to 250 μm） were generated in real time at 1024 × 1024 pixels （0.8 frames/s） by placing the probe onto the tissue in gentle, stable contact. Tissue specimens were sampled for histopathological correlation.RESULTS： The esophagus, stomach, small and large intestine and meso, liver, pancreas and gall bladder were visualised in vivo at high resolution in n = 48 mice. Real time microscopic imaging with the confocal minimicroscopy probe was easy to achieve. The different staining protocols （fluorescein, acriflavine, FITC-labelled dextran and L. esculentum lectin） each highlighted specific aspects of the tissue, and in vivo imaging correlated excellently with conventional histology. In vivo blood flow monitoring added a functional quality to morphologic imaging.CONCLUSION： Confocal microscopy is feasible in vivo allowing the visualisation of the complete GI tract at high resolution even of subsurface tissue structures. The new confocal probe design evaluated in this study is compatible with laparoscopy and significantly expands the field of possible applications to intra-abdominal organs. It allows immediate testing of new in vivo staining and application options and therefore permits rapid transfer from animal studies to clinical use in patients.

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

To evaluate the clinical impact of confocal laser endomicroscopy (CLE) in the diagnosis and management of patients with an uncertain diagnosis. METHODSA 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. RESULTSA 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. CONCLUSIONCLE is a new diagnostic tool that has a significant clinical impact on the diagnosis and treatment of patients with uncertain diagnosis.

Confocal endomicroscopy:Is it time to move on?

Confocal laser endomicroscopy permits in-vivo microscopy evaluation during endoscopy procedures. It can be used in all the parts of the gastrointestinal tract and includes: Esophagus,stomach,small bowel,colon,biliary tract through and endoscopic retrograde cholangiopancreatography and pancreas through needles during endoscopic ultrasound procedures. Many researches demonstrated a high correlation of results between confocal laser endomicroscopy and histopathology in the diagnosis of gastrointestinal lesions; with accuracy in about 86% to 96%. Moreover,in spite that histopathology remains the gold-standard technique for final diagnosis of any diseases; a considerable number of misdiagnosis rate could be present due to many factors such as interpretation mistakes,biopsy site inaccuracy,or number of biopsies. Theoretically; with the diagnostic accuracy rates of confocal laser endomicroscopy could help in a daily practice to improve diagnosis and treatment management of the patients. However,it is still not routinely used in the clinical practice due to many factors such as cost of the procedure,lack of codification and reimbursement in some countries,absence of standard of care indications,availability,physician imageinterpretation training,medico-legal problems,and the role of the pathologist. These limitations are relative,and solutions could be found based on new researches focused to solve these barriers.

Large-field objective lens for multi-wavelength microscopy at mesoscale and submicron resolution

Conventional microscopes designed for submicron resolution in biological research are hindered by a limited field of view,typically around 1 mm.This restriction poses a challenge when attempting to simultaneously analyze various parts of a sample,such as different brain areas.In addition,conventional objective lenses struggle to perform consistently across the required range of wavelengths for brain imaging in vivo.Here we present a novel mesoscopic objective lens with an impressive field of view of 8 mm,a numerical aperture of 0.5,and a working wavelength range from 400 to 1000 nm.We achieved a resolution of 0.74μm in fluorescent beads imaging.The versatility of this lens was further demonstrated through high-quality images of mouse brain and kidney sections in a wide-field imaging system,a confocal laser scanning system,and a two-photon imaging system.This mesoscopic objective lens holds immense promise for advancing multi-wavelength imaging of large fields of view at high resolution.

Effects of contact lens wearing on keratoconus:a confocal microscopy observation

AIM： To evaluate the corneal cell morphology of new keratoconus patients wearing two different types of rigid gas-permeable（RGP） contact lenses for 1y.METHODS： Thirty nine eyes of 39 new keratoconus patients were selected and randomly fitted with two types of RGP contact lenses.Group 1 had 21 eyes with regular rigid gas-permeable（RRGP） contact lens and rest 18 eyes were in group 2 with specially designed rigid gas-permeable（SRGP） contact lens.Corneal cell morphology was evaluated using a slit scanning confocal microscope at no-lens wear and after 1y of contact lens wearing.RESULTS： After 1y of contact lens wearing in group 1,the mean anterior and posterior stromal keratocyte density were significantly less（P=0.006 and P=0.001,respectively） compared to no-lens wear.The mean cell area of anterior and posterior stromal keratocyte were also significantly different（P=0.005 and P=0.001） from no-lens wear.The anterior and posterior stromal haze increased by 18.74% and 23.81%,respectively after 1y of contact lens wearing.Whereas in group 2,statistically significant changes were observed only in cell density ＆ area of anterior stroma（P=0.001 and P=0.001,respectively） after 1y.While,level of anterior and posterior stromal haze increased by 16.67% and 11.11% after 1y of contact lens wearing.Polymegathism and pleomorphism also increased after 1y of contact lens wearing in both the contact lens groups.CONCLUSION： Confocal microscopy observation shows the significant alterations in corneal cell morphology of keratoconic corneas wearing contact lenses especially in group 1.The type of contact lens must be carefully selected to minimize changes in corneal cell morphology.

Confocal laser endomicroscopy in the “in vivo” histological diagnosis of the gastrointestinal tract

Recent technological advances in miniaturization have allowed for a confocal scanning microscope to be integrated into a conventional flexible endoscope,or into trans-endoscopic probes,a technique now known as confocal endomicroscopy or confocal laser endomicroscopy.This newly-developed technology has enabled endoscopists to collect real-time in vivo histological images or "virtual biopsies" of the gastrointestinal mucosa during endoscopy,and has stimulated significant interest in the application of this technique in clinical gastroenterology.This review aims to evaluate the current data on the technical aspects and the utility of this new technology in clinical gastroenterology and its potential impact in the future,particularly in the screening or surveillance of gastrointestinal neoplasia.

In vivo corneal confocal microscopy in diabetes: Where we are and where we can get

In vivo corneal confocal microscopy(IVCCM) is a novel,reproducible, easy and noninvasive technique that allows the study of the different layers of the cornea at a cellular level. As cornea is the most innervated organ of human body, several studies investigated the use of corneal confocal microscopy to detect diabetic neuropathies, which are invalidating and deadly complications of diabetes mellitus. Corneal nerve innervation has been shown impaired in subjects with diabetes and a close association between damages of peripheral nerves due to the diabetes and alterations in corneal sub-basal nerve plexus detected by IVCCM has been widely demonstrated. Interestingly, these alterations seem to precede the clinical onset of diabetic neuropathies, paving the path for prevention studies. However, some concerns still prevent the full implementation of this technique in clinical practice. In this review we summarize the most recent and relevant evidences about the use of IVCCM for the diagnosis of peripheral sensorimotor polyneuropathy and of autonomic neuropathy in diabetes. New perspectives and current limitations are also discussed.

Clinical features and in vivo confocal microscopy assessment in 12 patients with ocular cicatricial pemphigoid

AIM： To describe the clinical features and microstructural characteristics assessed by in vivo confocal microscopy（IVCM） in patients with ocular cicatricial pemphigoid（OCP）.· METHODS： A descriptive, uncontrolled case series study. Patients diagnosed with OCP were examined by clinical history, slit-lamp biomicroscopy features and IVCM images. The results of direct immunofluorescence（DIF） biopsies and indirect immunofluorescence（IIF） were also recorded. Local and systemic immunosuppressive therapy were administered and adjusted according to response.·RESULTS： A total of 12 consecutive OCP patients（7male, 5 female; mean age 60.42 ±10.39y） were recruited.All patients exhibited bilateral progressive conjunctival scarring and recurrent chronic conjunctivitis was the most frequent clinical pattern. The mean duration of symptoms prior to diagnosis of OCP was 2.95 ±2.85y（range： 5mo to 10y）. The Foster classification varied from stage I to IV and 20 eyes（83%） were within or greater than Foster stage Ⅲ on presentation. Two of the 12patients（17%） demonstrated positive DIF; 3 of the 12（25%） patients reported positive IIF. The mean duration of the follow-up period was 20.17 ±11.88mo（range： 6 to48mo）. IVCM showed variable degrees of abnormality in the conjuctiva-cornea and conjuctival scarring was detected in all the involved eyes. Corneal stromal cell activation and dendritic cell infiltration presented asocular surface inflammation, ocular surface keratinization along with the destroyed Vogt palisades was noted in eyes with potential limbal stem cell deficiency. After treatment, remission of ocular surface inflammation was achieved in all the patients, 18 eyes（75%） remained stable, 6 eyes（25%） had recurrent conjunctivitis and cicatrization in 2 eyes（8%） was progressing.· CONCLUSION： As an autoimmune disease, OCP manifests as variable degrees of clinical and laboratory abnormalities with both local and systemic immunosuppressive treatment playing important roles in disease therapy. IVCM can be as a valuable non-invasive technique to assess ocular surface changes in a cellular level with a potential value for providing diagnostic evidence and monitoring therapeutic effects during follow-up.

EFFECT OF THE TOTAL SAPONIN OF DIPSACUS ASPER ON INTRACELLULAR FREE CALCIUM CONCENTRATION IN THE CELLULAR MODEL OF ALZHEIMER'S DISEASE-SCANNING CONFOCAL MICROSCOPY

Objective To study the effect of ginsenoside Rb1 and total saponin of dipsacus asper on intracellular free calcium concentration mediated by β amyloid protein.So as to lay a foundation for developing effective Chinese traditional medicine to treat Alzheimer’s disease.Methods The technique of laser scanning confocal microscopy combining primary cultured neurons was adopted to quantitatively analyze the change of [Ca 2+ ] i.Results The [Ca 2+ ] i of primary cultured hippocampal neurons was nmol·L -1 on basal levels.Control group showed obvious change of calcium vibration,[Ca 2+ ] i was elevated to nmol·L -1 .The peak of [Ca 2+ ] i of Rb1 group reached nmol·L -1 and was lower than that of control group .The tSDA group displayed distinct change of calcium vibration too,and [Ca 2+ ] i reached nmol·L -1 .There was a significant difference in [Ca 2+ ] i between control and tSDA group .Conclusion The research indicated that one of mechanisms by which Rb1 and tSDA protected the neurons was to maintain the balance of [Ca 2+ ] i.

Investigation of confocal microscopy for differentiation of renal cell carcinoma versus benign tissue.Can an optical biopsy be performed?

Objective:Novel optical imaging modalities are under development with the goal of obtaining an“optical biopsy”to efficiently provide pathologic details.One such modality is confocal microscopy which allows in situ visualization of cells within a layer of tissue and imaging of cellular-level structures.The goal of this study is to validate the ability of confocal microscopy to quickly and accurately differentiate between normal renal tissue and cancer.Methods:Specimens were obtained from patients who underwent robotic partial nephrectomy for renal mass.Samples of suspected normal and tumor tissue were extracted from the excised portion of the kidney and stained with acridine orange.The stained samples were imaged on a Nikon E600 C1 Confocal Microscope.The samples were then submitted for hematoxylin and eosin processing and read by an expert pathologist to provide a gold-standard diagnosis that can later be compared to the confocal images.Results:This study included 11 patients,17 tissue samples,and 118 confocal images.Of the 17 tissue samples,10 had a gold-standard diagnosis of cancer and seven were benign.Of 118 confocal images,66 had a gold-standard diagnosis of cancer and 52 were benign.Six confocal images were used as a training set to train eight observers.The observers were asked to rate the test images on a six point scale and the results were analyzed using a web based receiver operating characteristic curve calculator.The average accuracy,sensitivity,specificity,and area under the empirical receiver operating characteristic curve for this study were 91%,98%,81%,and 0.94 respectively.Conclusion:This preliminary study suggest that confocal microscopy can be used to distinguish cancer from normal tissue with high sensitivity and specificity.The observers in this study were trained quickly and on only six images.We expect even higher performance as observers become more familiar with the confocal images.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy and needle-based confocal laser-endomicroscopy increase detection of potentially malignant pancreatic cystic lesions:A single-center study

BACKGROUND Currently,there is insufficient data about the accuracy in the diagnosing of pancreatic cystic lesions(PCLs),especially with novel endoscopic techniques such as with direct intracystic micro-forceps biopsy(mFB)and needle-based confocal laser-endomicroscopy(nCLE).AIM To compare the accuracy of endoscopic ultrasound(EUS)and associated techniques for the detection of potentially malignant PCLs:EUS-guided fine needle aspiration(EUS-FNA),contrast-enhanced EUS(CE-EUS),EUS-guided fiberoptic probe cystoscopy(cystoscopy),mFB,and nCLE.METHODS This was a single-center,retrospective study.We identified patients who had undergone EUS,with or without additional diagnostic techniques,and had been diagnosed with PCLs.We determined agreement among malignancy after 24-mo follow-up findings with detection of potentially malignant PCLs via the EUSguided techniques and/or EUS-guided biopsy when available(EUS malignancy detection).RESULTS A total of 129 patients were included, with EUS performed alone in 47/129. In 82/129 patients,EUS procedures were performed with additional EUS-FNA (21/82), CE-EUS (20/82), cystoscopy(27/82), mFB (36/82), nCLE (44/82). Agreement between EUS malignancy detection and the 24-mo follow-up findings was higher when associated with additional diagnostic techniques thanEUS alone [62/82 (75.6%) vs 8/47 (17%);OR 4.35, 95%CI: 2.70-7.37;P < 0.001]. The highestmalignancy detection accuracy was reached when nCLE and direct intracystic mFB were bothperformed, with a sensitivity, specificity, positive predictive value, negative predictive value andobserved agreement of 100%, 89.4%, 77.8%, 100% and 92.3%, respectively (P < 0.001 comparedwith EUS-alone).CONCLUSIONThe combined use of EUS-guided mFB and nCLE improves detection of potentially malignantPCLs compared with EUS-alone, EUS-FNA, CE-EUS or cystoscopy.

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

SUPPRESSION OF SIDELOBES IN SINGLE-PHOTON 4PI CONFOCAL MICROSCOPY BY FORSTER RESONANT ENERGY TRANSFER

Recently,we theoretically demonstrate that utilization of silica nanobeads co-doped with Cy3 and Cy5 molecules instead of single dye molecules asfluorescent labels can enable optical resolutions far beyond the diffraction-limit.Here,we show that by combining the 4Pi microscopy and the novelfluorescent label,it is possible to completely suppress the sidelobes in 4Pi focal spot and significantly enhance the optical resolution in the axial direction.

Aplication of <i>in Vivo</i>Confocal Microscopy in Ophtalmology—Overview

Confocal microscopy is a method which has been increasingly used over the last decade in the study of the anterior ocular surface. The method allows testing and in vivo high resolution imaging of the structures of the anterior eye segment, at a cellular level, which is close to the histological examination of tissues. The data provided by this method allow for a better understanding of both the functional and pathological processes occurring in the anterior ocular surface not only for scientific purposes but also in clinical practice. The aim of the present work is to summarize the current knowledge and applications of confocal microscopy of the anterior ocular surface.

Computing methods for icosahedral and symmetry-mismatch reconstruction of viruses by cryo-electron microscopy

Three-dimensional(3 D)reconstruction of icosahedral viruses has played a crucial role in the development of cryoelectron microscopy single-particle reconstruction,with many cryo-electron microscopy techniques first established for structural studies of icosahedral viruses,owing to their high symmetry and large mass.This review summarizes the computational methods for icosahedral and symmetry-mismatch reconstruction of viruses,as well as the likely challenges and bottlenecks in virus reconstruction,such as symmetry mismatch reconstruction,contrast transformation function(CTF)correction,and particle distortion.

Nevus changed by recurrent <i>Herpes</i>simplex infection: Reflectance confocal microscopy

During a screening program, a 24-year-old woman presented an itchy nodule above the upper lip, 5 × 5 mm in size with irregular pigmentation, which had enlarged over the previous three weeks. Personal clinical history revealed a recurrent Herpes virus infection. Dermoscopy showed light brown irregular pigmentation, milia-like cysts and an atypical vascular pattern. Reflectance confocal microscopy revealed architectural, cytologic and vascular features suggestive of melanoma. A Tzanck test revealed multinucleated keratinocytes with the typical nuclei infected by Herpes virus. Our case shows that dermoscopy alone, despite its sensitivity and specificity, may not provide adequate diagnostic accuracy on which to base a surgical decision. Epiluminescence criteria should be considered together with a clinical evaluation of the lesion and the patient’s clinical history. Reflectance-mode confocal microscopy confirmed the difficulty of presurgical diagnosis in this case, which highlights the importance of traditional cytological analysis in order to avoid unnecessary surgical treatment.