Applications of Data Characteristic AI-Assisted Raman Spectroscopy in Pathological Classification.

Raman spectroscopy has been widely used for label-free biomolecular analysis of cells and tissues for pathological diagnosis in vitro and in vivo. AI technology facilitates disease diagnosis based on Raman spectroscopy, including machine learning (PCA and SVM), manifold learning (UMAP), and deep learning (ResNet and AlexNet). However, it is not clear how to optimize the appropriate AI classification model for different types of Raman spectral data. Here, we selected five representative Raman spectral data sets, including endometrial carcinoma, hepatoma extracellular vesicles, bacteria, melanoma cell, diabetic skin, with different characteristics regarding sample size, spectral data size, Raman shift range, tissue sites, Kullback-Leibler (KL) divergence, and significant Raman shifts (i.e., wavenumbers with significant differences between groups), to explore the performance of different AI models (e.g., PCA-SVM, SVM, UMAP-SVM, ResNet or AlexNet). For data set of large spectral data size, Resnet performed better than PCA-SVM and UMAP. By building data characteristic-assisted AI classification model, we optimized the network parameters (e.g., principal components, activation function, and loss function) of AI model based on data size and KL divergence etc. The accuracy improved from 85.1 to 94.6% for endometrial carcinoma grading, from 77.1 to 90.7% for hepatoma extracellular vesicles detection, from 89.3 to 99.7% for melanoma cell detection, from 88.1 to 97.9% for bacterial identification, from 53.7 to 85.5% for diabetic skin screening, and mean time expense of 5 s.

The value of the dermal rim sign on nonenhanced MRI for predicting dermal backflow in patients with primary lower extremity lymphedema.

PURPOSE: The dermal rim sign (DRS) on nonenhanced MRI has been shown to predict dermal backflow (DBF) in patients with secondary upper limb lymphedema. However, whether DRS has the same effects on primary lower extremity lymphedema (PLEL) has not been clearly reported. Therefore, this study aimed to explore whether the DRS can be used to diagnose the DBF on lymphoscintigraphy in patients with PLEL. METHODS: Ninety-four patients who were diagnosed with PLEL were recruited for this retrospective study from January 2022 to December 2023. According to the findings of the lymphoscintigraphy, all patients were divided into two groups: non-DBF and DBF. The MRI data of the two groups were recorded and statistically compared for the following indicators: range of lymphedema involvement (left, right, whole lower limbs, only thigh, only calf+ankle), signs of lymphedema (notable thickening of skin, parallel line sign, grid sign, honeycomb sign, band sign, lymph lake sign, crescent sign, dermal rim sign), and lymphedema (skin thickness, band width). The dermal rim sign is characterized by notable thickening of the skin+grid sign/honeycomb sign (one or both of which appear)+band sign. RESULTS: The following statistically significant differences in the following indicators were found between the two groups (P<0.05): notable skin thickening, parallel line sign, grid sign, honeycomb sign, band sign, dermal rim sign, skin thickness and band width. The sensitivity of predicting DBF with the DRS was 82%, the specificity was 64%, and the accuracy was 77%. CONCLUSION: This study confirmed good consistency between the DRS and DBF from the perspective of imaging; this tool is suitable for children, adolescents, and patients with contraindications to lymphoscintigraphy. The DRS has important value in assessing the severity of PLEL. DRS is suggested for the clinical use of combined surgical treatment for PLEL.

A Senescence-Associated Secretory Phenotype of Bone Marrow Mesenchymal Stem Cells Inhibits the Viability of Breast Cancer Cells.

Breast cancer, the most prevalent malignancy in women, often progresses to bone metastases, especially in older individuals. Dormancy, a critical aspect of bone-metastasized breast cancer cells (BCCs), enables them to evade treatment and recur. This dormant state is regulated by bone marrow mesenchymal stem cells (BMMSCs) through the secretion of various factors, including those associated with senescence. However, the specific mechanisms by which BMMSCs induce dormancy in BCCs remain unclear. To address this gap, a bone-specific senescence-accelerated murine model, SAMP6, was utilized to minimize confounding systemic age-related factors. Confirming senescence-accelerated osteoporosis, distinct BMMSC phenotypes were observed in SAMP6 mice compared to SAMR1 counterparts. Notably, SAMP6-BMMSCs exhibited premature senescence primarily due to telomerase activity loss and activation of the p21 signaling pathway. Furthermore, the effects of conditioned medium (CM) derived from SAMP6-BMMSCs versus SAMR1-BMMSCs on BCC proliferation were examined. Intriguingly, only CM from SAMP6-BMMSCs inhibited BCC proliferation by upregulating p21 expression in both MCF-7 and MDA-MB-231 cells. These findings suggest that the senescence-associated secretory phenotype (SASP) of BMMSCs suppresses BCC viability by inducing p21, a pivotal cell cycle inhibitor and tumor suppressor. This highlights a heightened susceptibility of BCCs to dormancy in a senescent microenvironment, potentially contributing to the increased incidence of breast cancer bone metastasis and recurrence observed with aging.

A Ship Detection Model Based on Dynamic Convolution and an Adaptive Fusion Network for Complex Maritime Conditions.

Ship detection is vital for maritime safety and vessel monitoring, but challenges like false and missed detections persist, particularly in complex backgrounds, multiple scales, and adverse weather conditions. This paper presents YOLO-Vessel, a ship detection model built upon YOLOv7, which incorporates several innovations to improve its performance. First, we devised a novel backbone network structure called Efficient Layer Aggregation Networks and Omni-Dimensional Dynamic Convolution (ELAN-ODConv). This architecture effectively addresses the complex background interference commonly encountered in maritime ship images, thereby improving the model's feature extraction capabilities. Additionally, we introduce the space-to-depth structure in the head network, which can solve the problem of small ship targets in images that are difficult to detect. Furthermore, we introduced ASFFPredict, a predictive network structure addressing scale variation among ship types, bolstering multiscale ship target detection. Experimental results demonstrate YOLO-Vessel's effectiveness, achieving a 78.3% mean average precision (mAP), surpassing YOLOv7 by 2.3% and Faster R-CNN by 11.6%. It maintains real-time detection at 8.0 ms/frame, meeting real-time ship detection needs. Evaluation in adverse weather conditions confirms YOLO-Vessel's superiority in ship detection, offering a robust solution to maritime challenges and enhancing marine safety and vessel monitoring.

ERRα regulates synaptic transmission through reactive oxygen species in hippocampal neurons.

Reactive oxygen species (ROS) play multiple roles in synaptic transmission, and estrogen-related receptor α (ERRα) is involved in regulating ROS production. The purpose of our study was to explore the underlying effect of ERRα on ROS production, neurite formation and synaptic transmission. Our results revealed that knocking down ERRα expression affected the formation of neuronal neurites and dendritic spines, which are the basic structures of synaptic transmission and play important roles in learning, memory and neuronal plasticity; moreover, the amplitude and frequency of miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) were decreased. These abnormalities were reversed by overexpression of human ERRα. Additionally, we also found that knocking down ERRα expression increased intracellular ROS levels in neurons. ROS inhibitor PBN rescued the changes in neurite formation and synaptic transmission induced by ERRα knockdown. These results indicate a new possible cellular mechanism by which ERRα affects intracellular ROS levels, which in turn regulate neurite and dendritic spine formation and synaptic transmission.

Value of the short time inversion recovery sequence of magnetic resonance imaging in the staging of Klippel-Trenaunay syndrome complicated with lymphedema.

OBJECTIVE: Currently, the focus on limb lymphedema (LE) is on classification and staging. However, few scholars have conducted staging for Klippel-Trenaunay syndrome complicated LE (KTS-LE). This study aimed to investigate the value of the short time inversion recovery sequence of magnetic resonance imaging (MRI) in the staging of KTS-LE. METHODS: Forty-six patients who were diagnosed with KTS-LE were recruited for this retrospective study from July 2011 to November 2022. Referring to the clinical staging standard of lower extremity LE of the International Society of Lymphology in 2020, all patients were divided into three groups: stages I, II, and III. The MRI indicators of the three groups were recorded and statistically compared: LE range (unilateral bilateral, lower limbs, only thighs, only calves and ankles), abnormal parts (skin thickening, abnormal subcutaneous fat signal, abnormal muscle signal, muscle hypertrophy or contraction, abnormal bone signal, hyperostosis), and subcutaneous soft tissue signs (parallel line sign, grid sign, band sign, honeycomb sign, lymph lake sign, crescent sign, and nebula sign). RESULTS: There was a significant difference in the honeycomb sign among the three periods (P = .028). There was a significant difference between stage II and stage I disease (P < .05). There was a significant difference between stage II and stage III disease (P < .05). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the honeycomb sign in diagnosing KTS-LE of stage II were 87.5%, 63.2%, 33.3%, 96.0%, and 67.4%, respectively. In contrast, the other signs were not statistically significant among the three periods. CONCLUSIONS: The short time inversion recovery sequence of MRI is of great value in KTS-LE. The honeycomb sign is an important imaging indicator for the diagnosis of stage II disease. It is necessary to evaluate the severity of edema with MRI for KTS-LE, which is very important for therapeutic options.

An In Silico Platform to Predict Cardiotoxicity Risk of Anti-tumor Drug Combination with hiPSC-CMs Based In Vitro Study.

OBJECTIVE: Antineoplastic agent-induced systolic dysfunction is a major reason for interruption of anticancer treatment. Although targeted anticancer agents infrequently cause systolic dysfunction, their combinations with chemotherapies remarkably increase the incidence. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provide a potent in vitro model to assess cardiovascular safety. However, quantitatively predicting the reduction of ejection fraction based on hiPSC-CMs is challenging due to the absence of the body's regulatory response to cardiomyocyte injury. METHODS: Here, we developed and validated an in vitro-in vivo translational platform to assess the reduction of ejection fraction induced by antineoplastic drugs based on hiPSC-CMs. The translational platform integrates drug exposure, drug-cardiomyocyte interaction, and systemic response. The drug-cardiomyocyte interaction was implemented as a mechanism-based toxicodynamic (TD) model, which was then integrated into a quantitative system pharmacology-physiological-based pharmacokinetics (QSP-PBPK) model to form a complete translational platform. The platform was validated by comparing the model-predicted and clinically observed incidence of doxorubicin and trastuzumab-induced systolic dysfunction. RESULTS: A total of 33,418 virtual patients were incorporated to receive doxorubicin and trastuzumab alone or in combination. For doxorubicin, the QSP-PBPK-TD model successfully captured the overall trend of systolic dysfunction incidences against the cumulative doses. For trastuzumab, the predicted incidence interval was 0.31-2.7% for single-agent treatment and 0.15-10% for trastuzumab-doxorubicin sequential treatment, covering the observations in clinical reports (0.50-1.0% and 1.5-8.3%, respectively). CONCLUSIONS: In conclusion, the in vitro-in vivo translational platform is capable of predicting systolic dysfunction incidence almost merely depend on hiPSC-CMs, which could facilitate optimizing the treatment protocol of antineoplastic agents.

[hiPSCs and organoids: prediction of arrhythmogenic risks for optimized traditional Chinese medicine].

Accurate assessment of the risks associated with traditional Chinese medicine(TCM), such as the potential to induce serious cardiovascular adverse reactions including cardiac arrhythmias, is crucial. This article introduced the pharmacological evaluation strategies for cardiac safety and the progress in cardiac organ research, with a focus on discussing the application prospects of human induced pluripotent stem cells(hiPSCs) and organoids in assessing the risks of TCM-induced cardiac arrhythmias. Compared with traditional animal models, hiPSCs and organoid models provide better reference and predictive capabilities, allowing for more accurate simulation of human cardiac responses. Researchers have successfully generated various cardiac tissue models that mimic the structure and function of the heart to evaluate the effects of TCM on the heart. The hiPSCs model, by reprogramming adult cells into pluripotent stem cells and differentiating them into cardiac cells, enables the generation of personalized cardiac tissue, which better reflects individual differences and drug responses. This provides guidance for the assessment of TCM cardiac toxicity risks. By combining organoid model with cardiac safety pharmacology strategies such as electrocardiogram monitoring and ion channel function assessment, the impact of TCM on the heart can be comprehensively evaluated. In addition, the application of the Comprehensive in Vitro Proarrhythmia Assay(CiPA) approach improves the accuracy of evaluation. Applying the CiPA approach to TCM research reveals potential risks and provides a scientific basis for the clinical application and industrial development of TCM. In conclusion, organoid model and cardiac safety pharmacology evaluation strategies provide important tools for assessing the cardiac toxicity risks of TCM. The combination of hiPSCs model, comprehensive assessment methods, and the CiPA strategy enables an accurate assessment of the risks of TCM-induced cardiac arrhythmias, thus providing a scientific basis for the safe use and international recognition of TCM in clinical practice. This contributes to ensuring the safety and efficacy of TCM and promoting its clinical application and global acceptance.

Comparison of visual performance with iTrace analyzer following femtosecond laser-assisted cataract surgery with bilateral implantation of two different trifocal intraocular lenses.

AIM: To compare the postoperative binocular visual performance with an iTrace analyzer following femtosecond laser-assisted cataract surgery (FLACS) combined with bilateral implantation of two different types of diffractive trifocal intraocular lenses (IOL). METHODS: During this retrospective observational study, patients who received bilateral FLACS combined with implantation of two different types of diffractive trifocal IOLs were evaluated. According to the IOLs' different types and design, the patients were divided into AT LISA tri839MP group (tri839 group) and AcrySof PanOptix TFNT00 group (TFNT group). Study parameters included preoperative and postoperative uncorrected distance visual acuity (UDVA) at 5 m, uncorrected near visual acuity (UNVA) at 30 cm and 40 cm, uncorrected intermediate visual acuity (UIVA) at 60 cm and 80 cm, postoperative refractive status, objective visual qualities and total high order aberrations (HOAs) postoperatively. The postoperative complications were also recorded. RESULTS: Totally 56 eyes of 28 patients (tri839 group, n=26; TFNT group, n=30) were included. Preoperative baseline characteristics between groups were not statistically significantly different. UDVA was not significantly different between groups except for 1wk follow-up due to the postoperative corneal edema. TFNT group showed statistically significant better UNIA at 60 cm than tri839 group at the 1wk (0.05±0.19 vs 0.15±0.10 logMAR, P=0.013), 1mo (0.05±0.12 vs 0.15±0.09 logMAR, P=0.001) and 3mo (0.04±0.12 vs 0.15±0.11 logMAR, P=0.001) follow-up, while tri839 group showed statistically significant better UNIA at 80 cm than TFNT group at the 1d (0.14±0.15 vs 0.20±0.14 logMAR, P=0.041) and 1mo (0.09±0.07 vs 0.14±0.10 logMAR, P=0.042) follow-up. Postoperative refractive status showed stable at every visit. Modulated transfer function (MTF) values and strehl ratio (SR) values were improved and HOAs were lower significantly after surgery. CONCLUSION: FLACS with bilateral implantations of both tri839 and TFNT00 can achieve satisfactory natural whole-course vision, high postoperative refractive stability and good visual quality but without significantly difference. iTrace aberration instrument can accurately evaluate the visual quality under different status.

Path planning for mobile robots in complex environments based on improved ant colony algorithm.

Aiming at the problems of the basic ant colony algorithm in path planning, such as long convergence time, poor global path quality and not being suitable for dynamic environments and unknown environments, this paper proposes a path planning method for mobile robots in complex environments based on an improved ant colony (CBIACO) algorithm. First, a new probability transfer function is designed for an ant colony algorithm, the weights of each component in the function are adaptively adjusted to optimize the convergence speed of the algorithm, and the global path is re-optimized by using the detection and optimization mechanism of diagonal obstacles. Second, a new unknown environment path exploration strategy (UPES) is designed to solve the problem of poor path exploration ability of the ant colony algorithm in unknown environment. Finally, a collision classification model is proposed for a dynamic environment, and the corresponding dynamic obstacle avoidance strategy is given. The experimental results show that CBIACO algorithm can not only rapidly generate high-quality global paths in known environments but also enable mobile robots to reach the specified target points safely and quickly in a variety of unknown environments. The new dynamic obstacle avoidance strategy enables the mobile robot to avoid dynamic obstacles in different directions at a lower cost.

Region-specific sympatho-adrenergic regulation of specialized vasculature in bone homeostasis and regeneration.

Type H vessels couple angiogenesis with osteogenesis, while sympathetic cues regulate vascular and skeletal function. The crosstalk between sympathetic nerves and type H vessels in bone remains unclear. Here, we first identify close spatial connections between sympathetic nerves and type H vessels in bone, particularly in metaphysis. Sympathoexcitation, mimicked by isoproterenol (ISO) injection, reduces type H vessels and bone mass. Conversely, beta-2-adrenergic receptor (ADRB2) deficiency maintains type H vessels and bone mass in the physiological condition. In vitro experiments reveal indirect sympathetic modulation of angiogenesis via paracrine effects of mesenchymal stem cells (MSCs), which alter the transcription of multiple angiogenic genes in endothelial cells (ECs). Furthermore, Notch signaling in ECs underlies sympathoexcitation-regulated type H vessel formation, impacting osteogenesis and bone mass. Finally, propranolol (PRO) inhibits beta-adrenergic activity and protects type H vessels and bone mass against estrogen deficiency. These findings unravel the specialized neurovascular coupling in bone homeostasis and regeneration.

Translational Pharmacokinetic/Pharmacodynamic Modeling and Simulation of Oxaliplatin and Irinotecan in Colorectal Cancer.

Despite the recent advances in this field, there are limited methods for translating organoid-based study results to clinical response. The goal of this study was to develop a pharmacokinetic/pharmacodynamic (PK/PD) model to facilitate the translation, using oxaliplatin and irinotecan treatments with colorectal cancer (CRC) as examples. The PK models were developed using qualified oxaliplatin and irinotecan PK data from the literature. The PD models were developed based on antitumor efficacy data of SN-38 and oxaliplatin evaluated in vitro using tumor organoids. To predict the clinical response, translational scaling of the models was established by incorporating predicted ultrafiltration platinum in plasma or SN-38 in tumors to PD models as the driver of efficacy. The final PK/PD model can predict PK profiles and responses following treatments with oxaliplatin or irinotecan. After generation of virtual patient cohorts, this model simulated their tumor shrinkages following treatments, which were used in analyzing the efficacies of the two treatments. Consistent with the published clinical trials, the model simulation suggested similar patient responses following the treatments of oxaliplatin and irinotecan with regards to the probabilities of progression-free survival (HR = 1.05, 95%CI [0.97;1.15]) and the objective response rate (OR = 1.15, 95%CI [1.00;1.32]). This proposed translational PK/PD modeling approach provides a significant tool for predicting clinical responses of different agents, which may help decision-making in drug development and guide clinical trial design.

Quantitative evaluation of primary lower extremity lymphedema staging using MRI: a preliminary study.

Background: The staging of primary lower extremity lymphedema (LEL) is difficult yet vital in clinical work, and magnetic resonance imaging (MRI) can be used for quantitative assessment of primary LEL due to its high resolution for soft tissues. In this study, we evaluated the value of MRI-based soft tissue area measurements for staging primary LEL. Methods: A total of 90 consecutive patients with clinically diagnosed primary lower limb lymphoedema from January 2017 to December 2019 in Beijing Shijitan Hospital were enrolled retrospectively. Short time inversion recovery (STIR) sequence was applied to measure the total, muscle, bone, and subcutaneous areas in the upper 1/3 level of the bilateral lower calf. The difference between the affected and unaffected calf regarding the subcutaneous area was obtained, and (subcutaneous area)/(bone area) and (subcutaneous area)/(muscle area) were calculated. According to the International Society of Lymphology (ISL) clinical staging standard established in 2020, all patients were divided into stages I, II, and III, accordingly. Statistical analysis was performed to determine the validity of MRI measurements in staging LEL. Results: There were 33 patients classified as stage I clinically, 44 patients as stage II, and 13 patients as stage III. There were significant differences in total, subcutaneous, the difference in subcutaneous area of limbs, subcutaneous/bone (S/B), and subcutaneous/muscle (S/M) between stage I and II as well as between stage I and III (P<0.001), but not between stage II and III (P=0.706, 0.329, and 0.229, respectively). A positive correlation was detected between the clinical stage and difference in subcutaneous area of limbs (rho =0.752, P<0.001), S/B (rho =0.747, P<0.001), S/M (rho =0.709, P<0.001), and subcutaneous (rho =0.723, P<0.001). For staging primary LEL, receiver operating characteristic (ROC) curves indicated that the difference in subcutaneous area of limbs had the best discrimination ability among parameters [area under the ROC curve (AUC) =0.950; 95% confidence interval (CI): 0.875-0.987; sensitivity: 95.45%; specificity: 84.85%], followed by S/B (AUC =0.930; 95% CI: 0.848-0.975; sensitivity: 77.27%; specificity: 93.94%) and S/M (AUC =0.895; 95% CI: 0.804-0.953; sensitivity: 77.27%; specificity: 90.91%). The ROC curves indicated that subcutaneous area (AUC =0.927; 95% CI: 0.844-0.974; sensitivity: 84.09%, specificity: 90.91%) and total (AUC =0.852; 95% CI: 0.753-0.923; sensitivity: 70.45%; specificity: 90.91%) also had discrimination ability between stage I and II. Conclusions: The measurement of the soft tissue area of the calf may be used as an auxiliary method for staging primary LEL. For patients with unilateral primary LEL, the difference in subcutaneous area of limbs could be a specific indicator to distinguish clinical stage I from II.

Lymphoscintigraphy findings in patients with chylothorax: influence of biochemical parameters.

BACKGROUND: Chylothorax is a condition that can be challenging to diagnose due to its nonspecific clinical presentation. Several biochemical parameters of chylous pleural effusion have been identified as important indicators for the diagnosis of chylothorax. Lymphoscintigraphy is utilized to assess chylothorax and determine the location of chyle leakage. The present study aimed to evaluate the correlation between the biochemical parameters of chylous pleural effusion and 99mTc-dextran (99mTc-DX) lymphoscintigraphy in diagnosing chylothorax. MATERIAL AND METHODS: A total of 120 patients were enrolled in the study, 83 of the patients with unilateral chylothorax, and 37 with bilateral chylothorax. All patients underwent both 99mTc-DX lymphoscintigraphy and pleural effusion laboratory analysis. The 99mTc-DX lymphoscintigraphy images were categorized as positive or negative groups based on the presence or absence of abnormal radioactive tracer accumulation in the thorax, respectively. The biochemical parameters of the two groups were subsequently compared. RESULTS: Among these patients, 101 (84.17%) had exudative effusions, while 19 (15.83%) had transudative effusions, as determined by the levels of pleural effusion protein, lactate dehydrogenase and cholesterol. Abnormal tracer accumulation in thorax was observed in 82 patients (68.33%). Our findings indicated that lymphoscintigraphy results were not associated with exudative and transudative chylothorax (P = 0.597). The lymphoscintigraphy positive group displayed significantly higher levels of pleural effusion triglyceride and pleural effusion triglyceride/serum triglyceride ratio in all biochemical parameters, compared to the negative group (P = 0.000 and P = 0.005). We identified cutoff values of 2.870 mmol/L for pleural effusion triglycerides and 4.625 for pleural effusion triglyceride/serum triglyceride ratio, respectively, which can facilitate differentiating the positive and negative cases on lymphoscintigraphy. CONCLUSION: Lymphoscintigraphy technique is a dependable diagnostic tool for the qualitative assessment of chylous pleural effusion. Higher pleural effusion triglyceride level and pleural effusion triglyceride/serum triglyceride ratio indicate a positive result in patients with chylothorax on lymphoscintigraphy, with the cutoff values of 2.870 mmol/L and 4.625 aiding in the diagnosis.

Imaging the electron charge density in monolayer MoS2 at the Ångstrom scale.

Four-dimensional scanning transmission electron microscopy (4D-STEM) has recently gained widespread attention for its ability to image atomic electric fields with sub-Ångstrom spatial resolution. These electric field maps represent the integrated effect of the nucleus, core electrons and valence electrons, and separating their contributions is non-trivial. In this paper, we utilized simultaneously acquired 4D-STEM center of mass (CoM) images and annular dark field (ADF) images to determine the projected electron charge density in monolayer MoS2. We evaluate the contributions of both the core electrons and the valence electrons to the derived electron charge density; however, due to blurring by the probe shape, the valence electron contribution forms a nearly featureless background while most of the spatial modulation comes from the core electrons. Our findings highlight the importance of probe shape in interpreting charge densities derived from 4D-STEM and the need for smaller electron probes.

Spatial localization ability of planarians identified through a light maze paradigm.

Spatial localization ability is crucial for free-living animals to fit the environment. As shown by previous studies, planarians can be conditioned to discriminate directions. However, due to their simplicity and primitiveness, they had never been considered to have true spatial localization ability to retrieve locations of objects and places in the environment. Here, we introduce a light maze training paradigm to demonstrate that a planarian worm can navigate to a former recognized place from the start point, even if the worm is transferred into a newly produced maze. This finding identifies the spatial localization ability of planarians for the first time, which provides clues for the evolution of spatial learning. Since the planarians have a primitive brain with simple structures, this paradigm can also provide a simplified model for a detailed investigation of spatial learning.

A retrospective analysis of Stewart-Treves syndrome in the context of chronic lymphedema

Abstract Background stewart-treves syndrome (STS) is an angiosarcoma associated with chronic lymphedema. Objectives This article analyses the characteristics of twenty-two patients and proposes active intervention in lymphedema and the early diagnosis of STS. Methods Twenty-two patients with STS were diagnosed at the centre over an 11-year period. Clinical manifestations, a series of conventional analyses, and histopathology were used to study these cases retrospectively. Results The age range of 22 patients with STS was 15 to 78 years. The main clinical manifestations included multiple skin and subcutaneous nodules and scattered red or purplish-red rashes in the lymphoedematous limbs. These patients often showed clinical symptoms such as lymphedema, weakness, emaciation, pain, mass, lymphadenopathy and so on. The positive rates of ultrasonography, MRI and radionuclide imaging were 66.7% (6/9), 92.3% (12/13) and 18.2% (2/11), respectively. The main points regarding active intervention in lymphedema and early diagnosis of STS were summarized. Study limitations Since this was a retrospective study, the main points summarized by the author need to be further quantified in clinical work to guide the diagnosis of this kind of disease more conveniently. In addition, further clinical trials are needed to evaluate the role of lymphedema in the occurrence and development of malignant tumors. Conclusions STS can appear in lymphoedematous tissue many years after lymphedema onset. To avoid delays in the diagnosis and therapy of STS, physicians should actively look for signs or symptoms of malignant lymphedema during the follow-up period and promptly manage patients developing problems.