51 research outputs found

    Treatment experience for different risk groups of Kaposiform hemangioendothelioma

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    BackgroundKaposiform hemangioendothelioma (KHE) is a rare vascular tumor with a high risk of mortality. Few studies with large samples of KHE have been reported. KHE may develop into the Kasabach–Merritt phenomenon (KMP), which is characterized by thrombocytopenia and consumptive coagulopathy. The features of severe symptomatic anemia and life-threatening low platelets make the management of KHE associated with KMP challenging.ObjectiveThe aim of this study was to examine the clinical characteristics of patients with KHE and discuss the treatment experience for different risk groups of KHE.MethodsThrough a retrospective review of 70 patients diagnosed with KHE between 2017 and 2022 in our center, we classify lesions into three clinicopathological stages based on the tumor involving depth, and divided the severity of KHE into three levels by estimating clinicopathological stages and severity of thrombocytopenia. Treatments of different severity groups were estimated with sufficient data.ResultsIn our cohort, 27% were neonates, and KHE lesion occurred at birth in 84% of patients. There was a slight male predominance (32 girls and 38 boys). Common clinical characteristics included associated coagulation disorder (100%), locally aggressive cutaneous blue–purple mass (89%), thrombocytopenia (78%), and local pain or joint dysfunction (20%). The lower extremities were the dominant location (35%), followed by the trunk (29%), the maxillofacial region and neck (24%), and the upper extremities (10%). Of the total cohort, 78% developed KMP; the median age at which thrombocytopenia occurred was 27.8 days. The median platelet count of patients who were associated with KMP was 24,000/µL in our cohort. Ninety-two percent of patients were given surgery treatment and 89% of these patients were given high-dose methylprednisolone (5-6 mg/kg daily) before surgery. In 55 patients with KMP, 36% were sensitive to high-dose corticosteroid therapy. Patients from the low-risk group (eight cases) underwent operation, all of whom recovered without recurrence after a maximum follow-up of 5 years. Out of 26 patients from the high-risk group, 25 underwent surgery treatment, with 1 case undergoing secondary surgery after recurrence and 1 case taking sirolimus. Out of 36 cases from the extremely high-risk group, 32 underwent surgery (including 2 cases who underwent external carotid artery ligation and catheterization), 3 of whom underwent secondary operation after recurrence, and the remaining 4 cases took medicine. The mean length of having sirolimus was 21 months; two cases stopped taking sirolimus due to severe pneumonia. Two cases died at 1 and 3 months after discharge.ConclusionsOur study describes the largest assessment of high-risk patients with KHE who have undergone an operation to date, with 5 years of follow-up to track recovery, which provides invaluable knowledge for the future treatment of patients with KHE and KMP from different risk groups: Early surgical intervention may be the most definitive treatment option for most patients with KHE; multimodality treatment is the best choice for the extremely high-risk group

    Transcriptional profiles of drought-responsive genes in modulating transcription signal transduction, and biochemical pathways in tomato

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    To unravel the molecular mechanisms of drought responses in tomato, gene expression profiles of two drought-tolerant lines identified from a population of Solanum pennellii introgression lines, and the recurrent parent S. lycopersicum cv. M82, a drought-sensitive cultivar, were investigated under drought stress using tomato microarrays. Around 400 genes identified were responsive to drought stress only in the drought-tolerant lines. These changes in genes expression are most likely caused by the two inserted chromosome segments of S. pennellii, which possibly contain drought-tolerance quantitative trait loci (QTLs). Among these genes are a number of transcription factors and signalling proteins which could be global regulators involved in the tomato responses to drought stress. Genes involved in organism growth and development processes were also specifically regulated by drought stress, including those controlling cell wall structure, wax biosynthesis, and plant height. Moreover, key enzymes in the pathways of gluconeogenesis (fructose-bisphosphate aldolase), purine and pyrimidine nucleotide biosynthesis (adenylate kinase), tryptophan degradation (aldehyde oxidase), starch degradation (β-amylase), methionine biosynthesis (cystathionine β-lyase), and the removal of superoxide radicals (catalase) were also specifically affected by drought stress. These results indicated that tomato plants could adapt to water-deficit conditions through decreasing energy dissipation, increasing ATP energy provision, and reducing oxidative damage. The drought-responsive genes identified in this study could provide further information for understanding the mechanisms of drought tolerance in tomato

    Heterogeneous strain distribution of elastomer substrates to enhance the sensitivity of stretchable strain sensors

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    Stretchable strain sensors, which convert mechanical stimuli into electrical signals, largely fuel the growth of wearable bioelectronics due to the ubiquitous, health-related strain in biological systems. In contrast to rigid conventional strain sensors, stretchable strain sensors present advantages of conformality and stretchability, solving the mechanical mismatch between electronics and the human body. However, the great challenge of stretchable strain sensors lies in achieving high sensitivity, which is required for both signal fidelity and cost considerations. Recent advances to solve this sensitivity challenge have focused on material optimization, in search of the optimum combination of conductive active materials and elastomer substrates among a myriad of artificial or natural materials. However, high sensitivity with a gauge factor larger than 50 remains a grand challenge, especially within large-strain regions.Here we present heterogeneous strain distribution of elastomer substrates as a powerful strategy to significantly enhance the sensitivity of stretchable strain sensors. The theoretical foundation of this strategy is mathematically proven on the basis of Ohm’s law in electrics and mechanics of materials. First, the extent of the sensitivity enhancement is proved to be determined by the local strain in resistance-testing segments of heterogeneous strain sensors. Next, the local strain is proved to be quantitatively decided by material properties such as section area and Young’s modulus. Thus, the necessary and sufficient condition to achieve high sensitivity in heterogeneous strain sensors is that the Young’s modulus reciprocal or section area reciprocal in the resistance-testing segment is larger than the mean value. This provides a theoretical design guideline to achieve high sensitivity via heterogeneous strain distribution. On the basis of this guideline, we systematically summarize concrete instances of heterogeneity-induced sensitivity improvement in stretchable strain sensors, in sequence of increasing dimensionality. A typical example of a one-dimensional heterogeneous strain sensor is a structured fiber with microbeads, where the varied section area along the fiber axis results in heterogeneous strain and sensitivity improvement. Two-dimensional heterogeneous sensors in the form of thin films contain thickness gradient sensors and auxetic mechanical metamaterial sensors. The former exhibit heterogeneous section area via the self-pinning method, while the latter show heterogeneity in both the strain direction and amplitude, leading to a 24-fold improvement in sensitivity. Three-dimensional strain sensors include rationally structured sensors for out-of-plane force detection and asymmetric active materials in electronic whiskers. The resultant enhanced sensitivity in these heterogeneous strain sensors is beneficial for applications such as continuous health monitoring, biomedical diagnostics, and replacement prosthetics, taking advantage of augmented detection accuracy and declined device cost. Finally, we discuss possible future work in exploiting heterogeneous strain distributions, involving extended methodology to achieve heterogeneity, employing suppressed strain for stretchable electrodes, cyclic durability for long-term applications, and multifunctional system-level integration. We believe that this strategy of using heterogeneous strain distribution to enhance sensitivity can strongly promote the development of stretchable strain sensors for both practical and theoretical requirements.NRF (Natl Research Foundation, S’pore)MOE (Min. of Education, S’pore)Accepted versio

    Mechanomaterials: a rational deployment of forces and geometries in programming functional materials

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    The knowledge of mechanics of materials has been extensively implemented in developing functional materials, giving rise to recent advances in soft actuators, flexible electronics, mechanical metamaterials, tunable mechanochromics, regenerative mechanomedicine, etc. While conventional mechanics of materials offers passive access to mechanical properties of materials in existing forms, a paradigm shift is emerging toward proactive programming of materials' functionality by leveraging the force-geometry-property relationships. Here, such a rising field is coined as "mechanomaterials". To profile the concept, the design principles in this field at four scales is first outlined, namely the atomic scale, the molecular scale, the manipulation of nanoscale materials, and the microscale design of structural materials. A variety of techniques have been recruited to deliver the multiscale programming of functional mechanomaterials, such as strain engineering, capillary assembly, topological interlocking, kirigami, origami, to name a few. Engineering optical and biological functionalities have also been achieved by implementing the fundamentals of mechanochemistry and mechanobiology. Nonetheless, the field of mechanomaterials is still in its infancy, with many open challenges and opportunities that need to be addressed. The authors hope this review can serve as a modest spur to attract more researchers to further advance this field.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Research Foundation (NRF)Submitted/Accepted versionThe authors thank the financial support from the Agency for Science, Technology and Research (A*STAR) under its AME Programmatic Funding Scheme (project no. A18A1b0045) Cyber-Physiochemical Interfaces (CPI) Programme, the National Research Foundation, Prime Minister’s office, Singapore, under its NRF Investigatorship (NRF-NRFI2017-07), and Singapore Ministry of Education (MOE2017-T2-2-107)

    Surgical treatment of kaposiform hemangioendothelioma in the pelvic cavity, bladder and ureter

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    Kasabach-Merritt phenomenon (KMP) is a rare potentially life-threatening consumptive coagulopathy characterized by thrombocytopenia and hypofibrinogenemia occurring associated with the vascular tumors kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). KHE in the specific sites will also cause some non-hemorrhagic complications. We report a two-month old female infant with KHE in her pelvic cavity, bladder and ureter who responded well to surgical excision. Keywords: Kaposiform hemangioendothelioma, Kasabach-Merritt phenomenon, Pelviccavity, Bladder, Ureter, Surgical excision, Thrombocytopenia, Coagulopathy, Therap

    A systematic review of unilateral versus bilateral percutaneous vertebroplasty/percutaneous kyphoplasty for osteoporotic vertebral compression fractures

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    Objective: The aim of this study was to compare the unilateral and bilateral approaches in treating osteoporotic vertebral compression fractures. Methods: Based on the principles and methods of the Cochrane systematic reviews, the records of the Cochrane Library, PubMed, Web of Science, Chinese Bio-medicine database, China Journal Full-text Database, VIP database, and Wanfang database were reviewed until October 2014. The randomized controlled trials on unilateral and bilateral approaches to percutaneous vertebroplasty (PVP)/percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures were included. The risk of bias of included trials was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions Version. The RevMan Software 5.0 was used for meta-analysis. Results: Fifteen randomized controlled trials with a total of 850 patients were included. Risk of bias in the included studies was inevitable. There was no statistically significant difference in visual analog scale, vertebral height, kyphotic angular, and quality of life. The main operative complications were bone cement leakage and adjacent vertebral fracture, without difference between the two groups. Conclusions: In view of the current evidence, there is insufficient evidence to show any difference between the unilateral and bilateral approaches in both the PVP and PKP treatment in osteoporotic vertebral compression fractures. Level of Evidence: Level I, Therapeutic study. Keywords: Minimally invasive surgery, Osteoporotic vertebral compression fracture, Percutaneous kyphoplasty, Percutaneous vertebroplasty, Systematic revie
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