BACKGROUND: Corneal confocal microscopy (CCM) is a noninvasive technique to detect early nerve damage of diabetic sensorimotor polyneuropathy (DSPN). Time in range (TIR) is an emerging metric of glycemic control which was reported to be associated with diabetic complications. We sought to explore the relationship between TIR and corneal nerve parameters in asymptomatic patients with type 2 diabetes (T2DM). METHODS: In this cross-sectional study, 206 asymptomatic inpatients with T2DM were recruited. After 7 days of continuous glucose monitoring, the TIR was calculated as the percentage of time in the glucose range of 3.9 to 10.0 mmol/L. CCM was performed to determine corneal nerve fiber density, corneal nerve branch density, and corneal nerve fiber length (CNFL). Abnormal CNFL was defined as ≤15.30 mm/mm 2 . RESULTS: Abnormal CNFL was found in 30.6% (63/206) of asymptomatic subjects. Linear regression analyses revealed that TIR was positively correlated with CCM parameters both in the crude and adjusted models (all P   <  0.05). Each 10% increase in TIR was associated with a 28.2% (95% CI: 0.595-0.866, P  = 0.001) decreased risk of abnormal CNFL after adjusting for covariates. With the increase of TIR quartiles, corneal nerve fiber parameters increased significantly (all P for trend <0.01). The receiver operating characteristic curve indicated that the optimal cutoff point of TIR was 77.5% for predicting abnormal CNFL in asymptomatic patients. CONCLUSIONS There is a significant independent correlation between TIR and corneal nerve fiber loss in asymptomatic T2DM patients. TIR may be a useful surrogate marker for early diagnosis of DSPN.
Humans ; Diabetes Mellitus, Type 2/complications* ; Cross-Sectional Studies ; Blood Glucose Self-Monitoring ; Blood Glucose ; Nerve Fibers ; Diabetic Neuropathies ; Cornea ; Microscopy, Confocal/methods*

Blood Glucose Self-Monitoring ; Blood Glucose ; Cornea ; Microscopy, Confocal

Confocal laser endomicroscopy technology can obtain cell-level images in real time and in situ, which can assist doctors in real-time intraoperative diagnosis, but its non-invasiveness makes it difficult to relocate the optical biopsy site. The confocal probe localization algorithm can automatically calculate the coordinates of the probe tip, that is, the coordinates of the optical biopsy site. In this paper, a confocal probe localization algorithm based on region growing and endoscope size prior was proposed. The algorithm detected the probe region by region growing on the probe edge image, then searched for tip points based on a given probe axis, and iteratively optimized it. Finally, based on the single-degree-of-freedom motion characteristics of the probe, the three-dimensional coordinates of the tip of the probe were calculated by using the prior information of the size of the endoscope, which solved the scale uncertainty problem of the monocular camera. The confocal probe localization algorithm was tested on the dataset collected in this paper. The results showed that our algorithm no longer relied on the color information of the probe, avoided the influence of uneven illumination on the gray value of the probe pixels, and had a more robust location accuracy and running speed. Within the length of the probe extending out of the endoscope from 0 to 5 cm, the pixel error could be as low as 11.76 pixels, and the average relative position error could be as low as 1.66 mm, which can achieve the real-time and accurate localization of the confocal probe.
Endoscopes ; Algorithms ; Microscopy, Confocal/methods*

Diabetic peripheral neuropathy(DPN),a chronic diabetic microvascular complication with a high incidence among diabetic patients,increases the risk of diabetic foot and amputation.Many methods are available for screening and evaluating DPN,including traditional 10 g monofilament,tuning fork and vibration perception,and tendon reflex tests,which should be combined with some nerve function score systems to improve the detection rate and accuracy for DPN.In recent years,a number of noninvasive new techniques have been developed for the evaluation of nerve injury,such as corneal confocal microscopy,quantitative sensory testing,current perception threshold test,sympathetic sudomotor function evaluation,and quantitative detection of skin advanced glycation end products.This paper reviews these noninvasive methods for screening and evaluating DPN to help clinicians detect and focus on DPN early.
Cornea ; Diabetes Mellitus ; Diabetic Foot ; Diabetic Neuropathies/diagnosis* ; Humans ; Mass Screening ; Microscopy, Confocal

Dermoscopy ; Diagnosis, Differential ; Humans ; Microscopy, Confocal ; Psoriasis/diagnostic imaging* ; Skin Neoplasms/diagnosis*

Glutathione (GSH) is a major antioxidant in cells, and plays vital roles in the cellular defense against oxidants and in the regulation of redox signals. In a previous report, we demonstrated that stem cell function is critically affected by heterogeneity and dynamic changes in cellular GSH concentration. Here, we present a detailed protocol for the monitoring of GSH concentration in living stem cells using FreSHtracer, a real-time GSH probe. We describe the steps involved in monitoring GSH concentration in single living stem cells using confocal microscopy and flow cytometry. These methods are simple, rapid, and quantitative, and able to demonstrate intracellular GSH concentration changes in real time. We also describe the application of FreSHtracer to the sorting of stem cells according to their GSH content using flow cytometry. Typically, microscopic or flow cytometric analyses of FreSHtracer and MitoFreSHtracer signals in living stem cells take ~2~3 h, and the fractionation of stem cells into subpopulations on the basis of cellular GSH levels takes 3~4.5 h. This method could be applied to almost every kind of mammalian cell with minor modifications to the protocol described here.
Flow Cytometry ; Fluorescent Dyes ; Glutathione ; Methods ; Microscopy, Confocal ; Oxidants ; Oxidation-Reduction ; Population Characteristics ; Stem Cells

OBJECTIVES: To investigate whether the cytotoxic effect of Cimicifuga rhizoma extract is associated with cell death in the human keratinocyte (HaCaT) and human melanoma cell lines (G361). METHODS: Apoptosis induced by Cimicifuga rhizoma extract was confirmed by water-soluble tetrazolium salts-1 (WST-1) assay, immunocytochemistry, and western blot. Additionally, the release of cytochrome c and apoptosis-inducing factor (AIF) was visualized by confocal laser scanning microscopy. RESULTS: The results showed that Cimicifuga rhizoma extract significantly reduced the viability of G361 cells with half-maximal inhibitory concentration (IC 50) of 200 µg/ml, and the apoptotic process was found to occur via the activation of caspase-3 and caspase-9 pathways. Besides, the release of cytochrome c and AIF was also detected. CONCLUSIONS: This study suggests that Cimicifuga rhizoma extract causes apoptosis of human melanoma cells through the intrinsic apoptotic pathway.
Apoptosis Inducing Factor ; Apoptosis ; Blotting, Western ; Caspase 3 ; Caspase 9 ; Cell Death ; Cell Line ; Cimicifuga ; Cytochromes c ; Humans ; Immunohistochemistry ; Keratinocytes ; Melanoma ; Microscopy, Confocal

PURPOSE: Direct application of atmospheric-pressure plasma jets (APPJs) has been established as an effective method of microbial decontamination. This study aimed to investigate the bactericidal effect of direct application of an APPJ using helium gas (He-APPJ) on Porphyromonas gingivalis biofilms on sandblasted and acid-etched (SLA) titanium discs. METHODS: On the SLA discs covered by P. gingivalis biofilms, an APPJ with helium (He) as a discharge gas was applied at 3 different time intervals (0, 3, and 5 minutes). To evaluate the effect of the plasma itself, the He gas–only group was used as the control group. The bactericidal effect of the He-APPJ was determined by the number of colony-forming units. Bacterial viability was observed by confocal laser scanning microscopy (CLSM), and bacterial morphology was examined by scanning electron microscopy (SEM). RESULTS: As the plasma treatment time increased, the amount of P. gingivalis decreased, and the difference was statistically significant. In the SEM images, compared to the control group, the bacterial biofilm structure on SLA discs treated by the He-APPJ for more than 3 minutes was destroyed. In addition, the CLSM images showed consistent results. Even in sites distant from the area of direct He-APPJ exposure, decontamination effects were observed in both SEM and CLSM images. CONCLUSIONS: He-APPJ application was effective in removing P. gingivalis biofilm on SLA titanium discs in an in vitro experiment.
Bacterial Load ; Biofilms ; Decontamination ; Helium ; In Vitro Techniques ; Methods ; Microbial Viability ; Microscopy, Confocal ; Microscopy, Electron, Scanning ; Plasma Gases ; Plasma ; Porphyromonas gingivalis ; Porphyromonas ; Stem Cells ; Titanium

PURPOSE: Surface alterations of titanium discs following instrumentation with either a nylon brush or a metal brush were evaluated. METHODS: A total of 27 titanium discs with 3 surface types (9 discs for each type), including machined (M) surfaces, sandblasted and acid-etched (SA) surfaces, and surfaces treated by resorbable blast media (RBM), were used. Three discs were instrumented with a nylon brush, another 3 discs were instrumented with a metal brush, and the remaining 3 discs were used as controls for each surface type. Surface properties including the arithmetic mean value of a linear profile (Ra), maximum height of a linear profile (Rz), skewness of the assessed linear profile (Rsk), arithmetic mean height of a surface (Sa), maximum height of a surface (Sz), developed interfacial area ratio (Sdr), skewness of a surface profile (Ssk), and kurtosis of a surface profile (Sku) were measured using confocal microscopy. RESULTS: Instrumentation with the nylon brush increased the Ra, Sa, and Sdr of the M surfaces. On the SA surfaces, Ra, Sa and Sdr decreased after nylon brush use. Meanwhile, the roughness of the RBM surface was not affected by the nylon brush. The use of the metal brush also increased the Ra, Sa, and Sdr of the M surface; however, the increase in Sdr was not statistically significant (P=0.119). The decreases in the Rz, Sz, Ra, Sa, and Sdr of the SA surfaces were remarkable. On the RBM surfaces, the use of the metal brush did not cause changes in Ra and Sa, whereas Rz, Sz, and Sdr were reduced. CONCLUSIONS: Titanium surfaces were altered when instrumented either with a nylon brush or a metal brush. Hence, it is recommended that nylon or metal brushes be used with caution in order to avoid damaging the implant fixture/abutment surface.
Dental Implants ; Microscopy, Confocal ; Nylons ; Peri-Implantitis ; Surface Properties ; Titanium

Diabetic polyneuropathy (DPN) causes neuropathic pain with reduced quality of life as well as diabetic foot ulceration which sometimes resulted in amputation. Early detection and improved knowledge of pathogenic pathways are important to prevent and to manage DPN. The screening methods and several tests to diagnose DPN-quantitative sensory testing, skin biopsy, corneal confocal microscopy, etc.-will be described.
Amputation ; Biopsy ; Diabetic Foot ; Diabetic Neuropathies ; Mass Screening ; Microscopy, Confocal ; Neuralgia ; Quality of Life ; Skin ; Ulcer