Quantitative analysis of lesion images to evaluate the efficiency of vascular-targeted photodynamic therapy for port-wine stains: Four case reports.

SIGNIFICANCE: Vascular-targeted photodynamic therapy (V-PDT) is a clinically approved therapeutic approach for treating vascular-related diseases, such as port-wine stains (PWS). For accurate treatment, varying light irradiance is required for different lesions due to the irregularity of vascular size, shape and degree of disease, which commonly alters during different stages of V-PDT. This makes quantitative analysis of the treatment efficiency urgently needed. APPROACH: Lesion images pre- and post- V-PDT treatment of patients with PWS were used to construct a quantitative method to evaluate the differences among lesions. Image analysis techniques were applied to evaluate the V-PDT efficiency for PWS by determining the Euclidean distances and two-dimensional correlation coefficients. RESULTS: According to the image analysis, V-PDT with good treatment efficiency resulted in a larger Euclidean distance and a smaller correlation coefficient compared with the case having lower V-PDT efficiency. CONCLUSIONS: A new method to quantify the Euclidean distances and correlation coefficients has been proposed, which is promising for the quantitative analysis of V-PDT efficiency for PWS.

Photodynamic therapy of vaginal intraepithelial neoplasia-How to do it?

Vaginal intraepithelial neoplasia (VaIN or VAIN), a rare precancerous disease, is difficult to treat. Photodynamic therapy (PDT) is a relatively new modality for the treatment of various precancerous mucosal lesions of the lower genital organs, including VaIN. Due to the special structure and location of the vagina, it is difficult to apply photosensitizer and light irradiation to VaIN lesions. This article provides a tutorial guide on the application of ALA-mediated intravaginal PDT for the treatment of VaIN lesions under different situations.

Photodynamic Therapy-Induced Anti-Tumor Immunity: Influence Factors and Synergistic Enhancement Strategies.

Photodynamic therapy (PDT) is an approved therapeutic procedure that exerts cytotoxic activity towards tumor cells by activating photosensitizers (PSs) with light exposure to produce reactive oxygen species (ROS). Compared to traditional treatment strategies such as surgery, chemotherapy, and radiation therapy, PDT not only kills the primary tumors, but also effectively suppresses metastatic tumors by activating the immune response. However, the anti-tumor immune effects induced by PDT are influenced by several factors, including the localization of PSs in cells, PSs concentration, fluence rate of light, oxygen concentration, and the integrity of immune function. In this review, we systematically summarize the influence factors of anti-tumor immune effects mediated by PDT. Furthermore, an update on the combination of PDT and other immunotherapy strategies are provided. Finally, the future directions and challenges of anti-tumor immunity induced by PDT are discussed.

The upregulation of immune checkpoints after photodynamic therapy reducing immune effect for treating breast cancer.

The immune effect induced by photodynamic therapy (PDT) has a limited effect on breast tumor. This study hypothesized that suppressive immune checkpoints on T cells might upregulate after PDT, which may reduce the antitumor effect of PDT for treating breast tumor. This study explored the alteration of immune checkpoint for the first time. A bilateral subcutaneous transplanted breast tumor mice model was established, and right tumors imitated primary tumors, and left tumors imitated distant tumors. Primary tumors were treated with PDT mediated by hematoporphyrin derivatives (HpD-PDT). Costimulatory molecules (ICOS, OX40, and 4-1BB) and immune checkpoints (PD1, LAG-3, CTLA-4, TIM-3, TIGIT) on tumor infiltrating T cells after HpD-PDT were analyzed by flow cytometry. Antitumor and immune effects were also assessed after HpD-PDT combined with anti-PD1 and LAG-3 antibodies. Primary tumors were suppressed, but distant tumors could not be inhibited after HpD-PDT. The number of T cells was increased, but function did not enhance after HpD-PDT. Additionally, costimulatory molecules (ICOS, OX40, and 4-1BB) were not elevated, but the suppressive immune checkpoints on tumor infiltrating T cells were upregulated after HpD-PDT. Notably, PD1+ LAG-3+ CD4+ T and PD1+ LAG-3+ CD8+ T cells were significantly increased. When PD1 and LAG-3 blockade combined with HpD-PDT, both primary and distant tumors were significantly suppressed, and antitumor immune effects were significantly enhanced. HpD-PDT could upregulate the PD1+ LAG-3+ CD4+ T and PD1+ LAG-3+ CD8+ T cells. Dual blockade of PD1 and LAG-3 immune checkpoints can enhance the antitumor effect of HpD-PDT.

In situ detection of human glioma based on tissue optical properties using diffuse reflectance spectroscopy.

Safely maximizing brain cancer removal without injuring adjacent healthy tissue is crucial for optimal treatment outcomes. However, it is challenging to distinguish cancer from noncancer intraoperatively. This study aimed to explore the feasibility of diffuse reflectance spectroscopy (DRS) as a label-free and real-time detection technology for discrimination between brain cancer and noncancer tissues. Fifty-five fresh cancer and noncancer specimens from 19 brain surgeries were measured with DRS, and the results were compared with co-registered clinical standard histopathology. Tissue optical properties were quantitatively obtained from the diffuse reflectance spectra and compared among different types of brain tissues. A machine learning-based classifier was trained to differentiate cancerous versus noncancerous tissues. Our method could achieve a sensitivity of 93% and specificity of 95% for discriminating high-grade glioma from normal white matter. Our results showed that DRS has the potential to be used for label-free, real-time in vivo cancer detection during brain surgery.

Mapping port wine stain in vivo by optical coherence tomography angiography and multi-metric characterization.

Port wine stain (PWS) is a congenital cutaneous capillary malformation composed of ecstatic vessels, while the microstructure of these vessels remains largely unknown. Optical coherence tomography angiography (OCTA) serves as a non-invasive, label-free and high-resolution tool to visualize the 3D tissue microvasculature. However, even as the 3D vessel images of PWS become readily accessible, quantitative analysis algorithms for their organization have mainly remained limited to analysis of 2D images. Especially, 3D orientations of vasculature in PWS have not yet been resolved at a voxel-wise basis. In this study, we employed the inverse signal-to-noise ratio (iSNR)-decorrelation (D) OCTA (ID-OCTA) to acquire 3D blood vessel images in vivo from PWS patients, and used the mean-subtraction method for de-shadowing to correct the tail artifacts. We developed algorithms which mapped blood vessels in spatial-angular hyperspace in a 3D context, and obtained orientation-derived metrics including directional variance and waviness for the characterization of vessel alignment and crimping level, respectively. Combining with thickness and local density measures, our method served as a multi-parametric analysis platform which covered a variety of morphological and organizational characteristics at a voxel-wise basis. We found that blood vessels were thicker, denser and less aligned in lesion skin in contrast to normal skin (symmetrical parts of skin lesions on the cheek), and complementary insights from these metrics led to a classification accuracy of ∼90% in identifying PWS. An improvement in sensitivity of 3D analysis was validated over 2D analysis. Our imaging and analysis system provides a clear picture of the microstructure of blood vessels within PWS tissues, which leads to a better understanding of this capillary malformation disease and facilitates improvements in diagnosis and treatment of PWS.

M-CSAFN: Multi-Color Space Adaptive Fusion Network for Automated Port-Wine Stains Segmentation.

Automatic segmentation of port-wine stains (PWS) from clinical images is critical for accurate diagnosis and objective assessment of PWS. However, this is a challenging task due to the color heterogeneity, low contrast, and indistinguishable appearance of PWS lesions. To address such challenges, we propose a novel multi-color space adaptive fusion network (M-CSAFN) for PWS segmentation. First, a multi-branch detection model is constructed based on six typical color spaces, which utilizes rich color texture information to highlight the difference between lesions and surrounding tissues. Second, an adaptive fusion strategy is used to fuse complementary predictions, which address the significant differences within the lesions caused by color heterogeneity. Third, a structural similarity loss with color information is proposed to measure the detail error between predicted lesions and truth lesions. Additionally, a PWS clinical dataset consisting of 1413 image pairs was established for the development and evaluation of PWS segmentation algorithms. To verify the effectiveness and superiority of the proposed method, we compared it with other state-of-the-art methods on our collected dataset and four publicly available skin lesion datasets (ISIC 2016, ISIC 2017, ISIC 2018, and PH2). The experimental results show that our method achieves remarkable performance in comparison with other state-of-the-art methods on our collected dataset, achieving 92.29% and 86.14% on Dice and Jaccard metrics, respectively. Comparative experiments on other datasets also confirmed the reliability and potential capability of M-CSAFN in skin lesion segmentation.

Melatonin protects against developmental PBDE-47 neurotoxicity by targeting the AMPK/mitophagy axis.

The neurotoxicity of 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) is closely linked to mitochondrial abnormalities while mitophagy is vital for mitochondrial homeostasis. However, whether PBDE-47 disrupts mitophagy contributing to impaired neurodevelopment remain elusive. Here, this study showed that neonatal PBDE-47 exposure caused learning and memory deficits in adult rats, accompanied with striatal mitochondrial abnormalities, neuronal apoptosis and the resultant neuronal loss. Mechanistically, PBDE-47 suppressed PINK1/Parkin-mediated mitophagy induction and degradation, inducing mitophagosome accumulation and mitochondrial dysfunction in vivo and in vitro. Additionally, stimulation of mitophagy by adenovirus-mediated Parkin or Autophagy-related protein 7 (Atg7) overexpression aggravated PBDE-47-induced mitophagosome accumulation, mitochondrial dysfunction, neuronal apoptosis and death. Conversely, suppression of mitophagy by the siRNA knockdown of Atg7 rescued PBDE-47-induced detrimental consequences. Importantly, melatonin, a hormone secreted rhythmically by the pineal, improved PBDE-47-caused neurotoxicity via preventing neuronal apoptosis and loss by restoring mitophagic activity and mitochondrial function. These neuroprotective effects of melatonin depended on activation of the AMP-activated protein kinase (AMPK)/Unc-51-like kinase 1 (ULK1) signaling. Collectively, these data indicate that PBDE-47 impairs mitophagy to perturb mitochondrial homeostasis, thus triggering apoptosis, leading to neuronal loss and consequent neurobehavioral deficits. Manipulation of the AMPK-mitophagy axis via melatonin could be a novel therapeutic strategy against developmental PBDE-47 neurotoxicity.

A water-dependent reversible photoacidity strategy for cancer treatment.

In the reported mechanisms of reversible photoacidity, protons were dissociated from compounds which contained hydroxyl, indazole or formed hydroxyl via intramolecular hydrogen abstraction under irradiation. Herein, a water-dependent reversible photoacidity (W-RPA) mechanism mediated by a thiadiazoloquinoxaline compound (TQs-Th-PEG5) has been found, in which the proton is not dissociated from TQs-Th-PEG5 itself but from a water locked by TQs-Th-PEG5 under the irradiation of a 660 nm laser. After turning off the laser, the produced acid will disappear quickly. This process is repeatable with no consumption of TQs-Th-PEG5. More importantly, water is indispensable. Furthermore, it is confirmed that there is no other element involved in the process except TQs-Th-PEG5, light and water. Excitingly, W-RPA therapy mediated by TQs-Th-PEG5 nanoparticle exhibits remarkable antitumor effect both in vitro and in vivo, especially in hypoxic tumors with diameter larger than 10 mm owing to its oxygen-independent feature. This study not only discovers a W-RPA mechanism but also provides a novel phototherapy strategy for cancer treatment.

A Novel Pyroptotic and Inflammatory Gene Signature Predicts the Prognosis of Cutaneous Melanoma and the Effect of Anticancer Therapies.

Purpose: The purpose of this study was to construct a gene signature comprising genes related to both inflammation and pyroptosis (GRIPs) to predict the prognosis of patients with cutaneous melanoma patients and the efficacy of immunotherapy, chemotherapy, and targeted therapy in these patients. Methods: Gene expression profiles were collected from The Cancer Genome Atlas. Weighted gene co-expression network analysis was performed to identify GRIPs. Univariable Cox regression and Lasso regression further selected key prognostic genes. Multivariable Cox regression was used to construct a risk score, which stratified patients into high- and low-risk groups. Areas under the ROC curves (AUCs) were calculated, and Kaplan-Meier analyses were performed for the two groups, following validation in an external cohort from Gene Expression Omnibus (GEO). A nomogram including the GRIP signature and clinicopathological characteristics was developed for clinical use. Gene set enrichment analysis illustrated differentially enriched pathways. Differences in the tumor microenvironment (TME) between the two groups were assessed. The efficacies of immune checkpoint inhibitors (ICIs), chemotherapeutic agents, and targeted agents were predicted for both groups. Immunohistochemical analyses of the GRIPs between the normal and CM tissues were performed using the Human Protein Atlas data. The qRT-PCR experiments validated the expression of genes in CM cell lines, Hacat, and PIG1 cell lines. Results: A total of 185 GRIPs were identified. A novel gene signature comprising eight GRIPs (TLR1, CCL8, EMP3, IFNGR2, CCL25, IL15, RTP4, and NLRP6) was constructed. The signature had AUCs of 0.714 and 0.659 for predicting 3-year overall survival (OS) in the TCGA entire and GEO validation cohorts, respectively. Kaplan-Meier analyses revealed that the high-risk group had a poorer prognosis. Multivariable Cox regression showed that the GRIP signature was an independent predictor of OS with higher accuracy than traditional clinicopathological features. The nomogram showed good accuracy and reliability in predicting 3-year OS (AUC = 0.810). GSEA and TME analyses showed that the high-risk group had lower levels of pyroptosis, inflammation, and immune response, such as lower levels of CD8+ T-cell infiltration, CD4+ memory-activated T-cell infiltration, and ICI. In addition, low-risk patients whose disease expressed PD-1 or CTLA-4 were likely to respond better to ICIs, and several chemotherapeutic and targeted agents. Immunohistochemical analysis confirmed the distinct expression of five out of the eight GRIPs between normal and CM tissues. Conclusion: Our novel 8-GRIP signature can accurately predict the prognosis of patients with CM and the efficacies of multiple anticancer therapies. These GRIPs might be potential prognostic biomarkers and therapeutic targets for CM.

Multiscale confocal photoacoustic dermoscopy to evaluate skin health.

Background: Photoacoustic dermoscopy (PAD) is a promising branch of photoacoustic microscopy (PAM) that can provide a range of functional and morphologic information for clinical assessment and diagnosis of dermatological conditions. However, most PAM setups are unsuitable for clinical dermatology because their single-scale mode and narrow frequency band result in insufficient imaging depth or poor spatiotemporal resolution when visualizing the internal texture of the skin. Methods: We developed a multiscale confocal photoacoustic dermoscopy (MC-PAD) with a multifunction opto-sono objective that could achieve high quality dermatological imaging. Using the objective to coordinate the spatial resolution and penetration depth, the MC-PAD was used to visualize pathophysiological biomarkers and vascular morphology from the epidermis (EP) to the dermis, which enabled us to quantify skin abnormalities without using exogenous contrast agents for human skin. Results: The MC-PAD was shown to have the ability to differentiate between different types of cells (such as red blood cells and melanoma cells), image and quantify pigment of the skin, and visualize skin morphology and blood capillary landmarks. The MC-PAD detected a significant difference in the structures of some pigmented and vascular lesions of skin diseases compared with that of healthy skin (P<0.01). The café au lait macule (CALM) skin type was found to have a relatively higher melanin concentration and thicker stratum basale (SB) in the EP than healthy skin. The dermal vascular network of skin that had a port wine stain (PWS) had greater diameters and a denser distribution than healthy skin, as reported in clinical trials. Conclusions: The MC-PAD has a broad range of applications for the diagnosis of human skin diseases and evaluation of the curative effect of treatments, and it can offer new perspectives in biomedical sciences.

In vitro and in vivo evaluation of a chlorin-based photosensitizer KAE® for cancer treatment.

BACKGROUND: Photodynamic therapy (PDT) has been approved for the clinical treatment of cancers. Photosensitizer (PS) is a crucial element of PDT. In the current study, in vitro and in vivo evaluation of a chlorin-based photosensitizer KAE® was performed. METHODS: The physicochemical characteristics of KAE® were compared with chlorin e6. The intracellular distribution of KAE® in HeLa cells was observed by laser scanning confocal microscopy. Reactive oxygen species (ROS) generation was detected through a 2', 7-dichlorodihydrofluorescein diacetate probe. The pharmacokinetics of KAE® was studied in mice. The photodynamic activities of KAE® and porphyrin based PSs were compared both in vitro and in vivo. The biosafety of KAE® in mice was evaluated by pathological section observation, blood routine examination and biochemistry assays. RESULTS: KAE® was readily dissolved in an aqueous solvent in a clinically acceptable concentration and showed a strong absorption at around 660 nm. Most of KAE® was located in the mitochondria of the tumor cells. Compared with hematoporphyrin derivative and 5-aminolevulinic acid, KAE® displayed a higher efficiency in cell killing. Furthermore, it could be completely eliminated from mouse body in 2 days. KAE® had no toxicity to mice under the tested dosage. CONCLUSIONS: Our results suggested that KAE® is an effective and safe PS for PDT in cancer therapy and has a promising prospect for clinical application.

Quantitative and anatomical imaging of dermal angiopathy by noninvasive photoacoustic microscopic biopsy.

The ability to noninvasively acquire the fine structure of deep tissues is highly valuable but remains a challenge. Here, a photoacoustic microscopic biopsy (PAMB) combined switchable spatial-scale optical excitation with single-element depth-resolved acoustic detection mode was developed, which effectively coordinated the spatial resolution and the penetration depth for visualizations of skin delamination and chromophore structures up to reticular dermis depth, with the lateral resolution from 1.5 to 104 µm and the axial resolution from 34 to 57 µm. The PAMB obtained anatomical imaging of the pigment distribution within the epidermis and the vascular patterns of the deep dermal tissue, enabling quantification of morphological abnormalities of angiopathy without the need for exogenous contrast agents. The features of healthy skin and scar skin, and the abnormal alteration of dermal vasculature in port wine stains (PWS) skin were first precisely displayed by PAMB-shown multi-layered imaging. Moreover, the quantitative vascular parameters evaluation of PWS were carried out by the detailed clinical PAMB data on 174 patients, which reveals distinct differences among different skin types. PAMB captured the PWS changes in capillary-loop depth, diameter, and vascular volume, making it possible to perform an objective clinical evaluation on the severity of PWS. All the results demonstrated the PAMB can provide vascular biopsy and new indexes deep into the dermal skin noninvasively, which should be meaningful to timely evaluate the pathological types and treatment response of skin diseases. This opens up a new perspective for label-free and non-invasive biopsies of dermal angiopathy.

Quantitative assessment of vascular features in port wine stains through optical coherence tomography angiography.

BACKGROUND: Vascular lesions such as port wine stains (PWS) lead to facial and psychological problems, which require careful and precise treatments. The key point of treating PWS is to selectively destroy the abnormal blood vessels. Hence, the in vivo monitoring of targeted vessels is crucial. Optical coherence tomography angiography (OCTA), an emerging label-free imaging tool, facilitates the evaluation of skin structure and vasculature at a high resolution. In this study, we utilised OCTA to capture the structural and vascular morphology in patients with PWS. Moreover, we quantitatively characterised the morphological features of different types of PWS. METHODS: This observational clinical study was conducted on 3 patients with flat PWS and 3 patients with thickened PWS. The age range was 4-27 years, and all of them had not received any treatment before this study. The OCTA images of the PWS lesions and contralateral skin were compared. Vascular morphology was characterized, and ectatic vessel depth was quantified according to the OCTA images. RESULTS: The blood vessels of the PWS lesions tend to had larger diameters and higher densities than those in the contralateral normal skin. The vessel diameters of PWS lesions were 73 ± 14 µm, with high heterogeneity ranging from 10 to >150 µm, however, the vessel diameters of normal skin were 28 ± 2 µm, ranging from 10 µm to 60 µm. In terms of different PWS lesions, the thickened type showed a trend of larger vessel diameter and higher density than those of the purplish red type. The ectatic vessels were located at the depth of 216 ± 13 µm in the PWS skin. CONCLUSIONS: OCTA can facilitate the in vivo three-dimensional visualization of structure and vasculature for PWS lesions. Various quantitative analysis parameters, such as vessel diameter, density, and depth, are typically measured using OCTA. This fact demonstrates the superior capability of OCTA for the precise and comprehensive assessment of PWS lesions.

Selective photodynamic inactivation of Helicobacter pylori by a cationic benzylidene cyclopentanone photosensitizer - an in vitro and ex vivo study.

The rise in the antibiotic resistance rate of Helicobacter pylori has led to an increasing eradication failure of this carcinogenic bacterial pathogen worldwide. This underlines the need for alternative antibacterial strategies against H. pylori infection. Antimicrobial photodynamic therapy (aPDT) is a promising non-pharmacological antibacterial technology. In this study, the selective killing activities of three benzylidene cyclopentanone (BCP) photosensitizers (Y1, P1 and P3) towards H. pylori over normal human gastric epithelial GES-1 cells were evaluated and the ex vivo photodynamic inactivation effect was preliminarily assessed on twelve H. Pylor-infected mice. Results showed that under the irradiation of 24 J/cm2 532 nm laser, Y1, P1 and P3 at 2.5 µM induced a 3-log10 reduction of H. pylori CFU (99.9% killing). Confocal images showed that P3, unlike Y1 and P1, could not be uptaken by GES-1 cells. P3 at 2.5 to 20 µM showed not significant (p > 0.05) phototoxicity to GES-1 cells, nevertheless, Y1 and P1 under the same concentrations exhibited remarkable phototoxicity to GES-1 cells. In the co-culture of H. pylori and GES-1 cells, P3 at 2.5 µM led to a complete eradication of H. pylori under the irradiation of 24 J/cm2 532 nm laser. While for the GES-1 cells, no significant (p > 0.05) phototoxicity was observed under the same aPDT dosage. The ex vivo experiments showed that P3 mediated aPDT resulted in 82.4% to 100% reduction of H. pylori CFU without damaging the gastric mucosa. To sum up, P3 is a promising anti-H. pylori photosensitizer with the ability to selectively photo-inactivate H. pylori while sparing normal gastric tissues.

Light delivery device modelling for homogenous irradiation distribution in photodynamic therapy of non-spherical hollow organs.

SIGNIFICANCE: Photodynamic therapy (PDT) is a useful treatment for select cancers. Homogeneous illumination is a key factor in the successful application of PDT treatment of tumours in hollow organs. Over illumination may damage normal tissue while under illumination may not ablate the target. BACKGROUND: There have been many approaches to provide homogeneous irradiation for PDT treatment of hollow organs, including light-scattering medium and isotropic emitter to diffuse light, a balloon filled with solution to expand the organ wall, and shaped fibres. In most studies, the organ is assumed to be spherical. However, many hollow organs treated by PDT are non-spherical, and the uniformity of azimuthal irradiation remains an unsolved problem for cylindrical light sources. OBJECTIVE: Find a design principle for homogeneous irradiation in a non-spherical cavity for PDT treatment. METHOD: A PDT light delivery device is modeled by a series of sub light sources placed along the longitudinal axis of an ellipsoid. In order to achieve a homogeneous azimuthal irradiation distribution on the elliptical arc, a cost function is solved by adding modulation coefficient to the emission profile. The coefficient of variation of uniformity (Ucov) describes the statistical dispersion of the variation in irradiation over the ellipsoid to the average value. Ucov is used to evaluate the homogeneity of the azimuthal irradiation distribution. RESULT: By minimizing the cost function, we found that the truncated Gaussian function can be chosen as the emission profile to generate homogeneous irradiation profile within an ellipsoid cavity model. The emission profile can be tailored to generate Ucov of 96.7 %. Further discussion shows that the light distribution could be generated practically by a side-emitting optical fibre, a LED array, or moving an isotropic emitter successively. The impact of emission angle of light sub-source is analysed and the irradiation profile from discrete longitudinal emissions is calculated. CONCLUSION: Theory analysis and simulation indicate that a cylindrical emitter with a non-uniform longitudinal emission profile (truncated Gaussian functions) results in an approximate homogeneous irradiance profile within an ellipsoidal cavity.

Automatic 3D adaptive vessel segmentation based on linear relationship between intensity and complex-decorrelation in optical coherence tomography angiography.

BACKGROUND: Vascular quantitative metrics have been widely used in the preclinical studies and clinical applications (e.g., the diagnosis and treatment of port wine stain, PWS), which require accurate vessel segmentation. An automatic 3D adaptive vessel segmentation is in need for a reproducible and objective quantification of the optical coherence tomography angiography (OCTA) image. METHODS: Human skin imaging was performed with a lab-built optical coherence tomography (OCT) system. Rather than separately applying the conventional 2-step (intensity and binarization) thresholding in the decorrelation-contrast OCTA, we proposed a 3D adaptive threshold using the linear relationship between the local intensity and complex-decorrelation which was termed as inverse SNR-decorrelation (ID) threshold. Furthermore, the ID threshold was automatically determined by defining a binary image similarity (BISIM) index as the feedback and searching the ID threshold with the minimal BISIM value. The proposed ID-BISIM threshold was applied to the acquired OCTA skin images for further vessel quantification. RESULTS: The proposed ID-BISIM threshold enabled a 3D adaptive binarization and presented superior sensitivity and specificity in vessel segmentation over conventional 2-step thresholding method in the decorrelation-contrast OCTA and a 37-65% improvement of the Youden's index in human skin experiments. The 3D binarization enabled a depth-resolved vessel skeleton and enhanced the differentiation of the overlapping vessels in the depth direction. Using ID-BISIM, the quantitative OCTA image presented a significant increase of vessel diameter index (P=0.0015) and vessel area density (VAD) (P=0.0485) as well as a significant decrease of vessel complexity index (VCI) (P=0.0094) in PWS lesion skin compared with normal skin. CONCLUSIONS: The proposed ID-BISIM method enables an automatic 3D adaptive vessel segmentation with enhanced performance in quantitative OCTA. The vascular quantitative metrics would be a useful tool for improving the diagnosis and the treatment of PWS.

Prevalence of human papillomavirus genotypes and precancerous cervical lesions in a screening population in Beijing, China: analysis of results from China's top 3 hospital, 2009-2019.

BACKGROUND: Cervical cancer is the fourth most common cancer in women. Early detection and diagnosis play an important role in secondary prevention of cervical cancer. This study aims to provide more information to develop an effective strategy for the prevention and control of cervical cancer in northern China. METHODS: A retrospective single-centre descriptive cross-sectional study was conducted in Chinese PLA General Hospital located in Beijing, covering the period from January 2009 to June 2019. The patients who underwent a polymerase chain reaction (PCR)-based HPV genotyping test and cervical pathological diagnosis were included. Furthermore, we limited the interval between the two examination within 180 days for the purpose of making sure their correlation to analyse their relationship. Moreover, the relationship between different cervical lesions and age as well as single/multiple HPV infection was assessed. RESULTS: A total of 3134 patients were eligible in this study after HPV genotyping test and pathological diagnosis. Most of the patients (95%) were from northern China. Among the patients, 1745(55.68%) had high-grade squamous intraepithelial neoplasia (HSIL), 1354 (43.20%) had low-grade squamous intraepithelial neoplasia (LSIL) and 35 (1.12%) were Normal. The mean age was 42.06 ± 10.82(range, 17-79 years). The women aged 35-49 years accounted for the highest incidence rate. The top five most commonly identified HPV genotypes in each lesion class were as follows: HPV16, 58, 52, 31 and 51 in the class of HSIL; HPV16, 52, 58, 56 and 51 in the class of LSIL; HPV16, 31, 6,11, 52 and 58 in the class of normal. The frequencies of HPV single genotype infection and multiple genotypes infection were 55.26 and 34.18%, respectively. There was no difference in the attributable proportions of multiple genotypes infection amongst HSIL, LSIL and Normal. CONCLUSIONS: In Northern China, HPV16 was the most dominant genotype in the patients with pathological examination. The peak age of the onset of HSIL was between 35 and 49 years of age. Infection with multiple HPV genotypes did not increase the risk of HSIL. Type-specific HPV prevalence and attribution proportion to cervical precancerous lesions should be taken into consideration in the development of vaccines and strategy for screening in this population.

Wide-field monitoring and real-time local recording of microvascular networks on small animals with a dual-raster-scanned photoacoustic microscope.

Photoacoustic microscopy (PAM) provides a new method for the imaging of small-animals with high-contrast and deep-penetration. However, the established PAM systems have suffered from a limited field-of-view or imaging speed, which are difficult to both monitor wide-field activity of organ and record real-time change of local tissue. Here, we reported a dual-raster-scanned photoacoustic microscope (DRS-PAM) that integrates a two-dimensional motorized translation stage for large field-of-view imaging and a two-axis fast galvanometer scanner for real-time imaging. The DRS-PAM provides a flexible transition from wide-field monitoring the vasculature of organs to real-time imaging of local dynamics. To test the performance of DRS-PAM, clear characterization of angiogenesis and functional detail was illustrated, hemodynamic activities of vasculature in cerebral cortex of a mouse were investigated. Furthermore, response of tumor to treatment were successfully monitored during treatment. The experimental results demonstrate the DRS-PAM holds the great potential for biomedical research of basic biology.

Modulating mitochondrial morphology enhances antitumor effect of 5-ALA-mediated photodynamic therapy both in vitro and in vivo.

5-aminolevulinic acid mediated PDT (5-ALA-PDT) is an approved therapeutic procedure for treating carcinomas of the cervix. However, when employed as a monotherapy, 5-ALA-PDT could not produce satisfactory results toward large and deep tumors. Therefore, developing a method to improve the efficacy of 5-ALA-PDT becomes important. In this study, we demonstrate an enhanced antitumor effect of 5-ALA-PDT by the modulation of mitochondrial morphology. The mitochondria in the cells were regulated into tubular mitochondria or fragmented mitochondria through over expression of Drp1 or Mfn2. Then these cells were treated with identical dose of 5-ALA-PDT. Our results suggest that HeLa cells predominantly containing fragmented mitochondria were more sensitive to 5-ALA-PDT than the cells predominantly containing tubular mitochondria. The morphology of mitochondria changed as the cell cycle progressed, with tubular mitochondria predominantly exhibited in the S phase and uniformly fragmented mitochondria predominantly displayed in the M phase. Paclitaxel significantly increased the population of M-phase cells, while 5-fluorouracil significantly increased the population of S-phase cells in xenograft tumors. Furthermore, low-dose paclitaxel significantly increased the antitumor effects of PDT. However, 5-fluorouracil didn't improve the antitumor effects of PDT. These results demonstrated an enhanced antitumor effect of 5-ALA-PDT from the modulation of mitochondrial morphology. We anticipate that our results will provide an insight for selecting potential chemotherapeutic agents to combine with PDT for tumor treatment.