82 research outputs found

    Natural images allow universal adversarial attacks on medical image classification using deep neural networks with transfer learning

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    Transfer learning from natural images is used in deep neural networks (DNNs) for medical image classification to achieve a computer-aided clinical diagnosis. Although the adversarial vulnerability of DNNs hinders practical applications owing to the high stakes of diagnosis, adversarial attacks are expected to be limited because training datasets (medical images), which are often required for adversarial attacks, are generally unavailable in terms of security and privacy preservation. Nevertheless, in this study, we demonstrated that adversarial attacks are also possible using natural images for medical DNN models with transfer learning, even if such medical images are unavailable; in particular, we showed that universal adversarial perturbations (UAPs) can also be generated from natural images. UAPs from natural images are useful for both non-targeted and targeted attacks. The performance of UAPs from natural images was significantly higher than that of random controls. The use of transfer learning causes a security hole, which decreases the reliability and safety of computer-based disease diagnosis. Model training from random initialization reduced the performance of UAPs from natural images; however, it did not completely avoid vulnerability to UAPs. The vulnerability of UAPs to natural images is expected to become a significant security threat

    Universal adversarial attacks on deep neural networks for medical image classification

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    Deep neural networks (DNNs) are widely investigated in medical image classification to achieve automated support for clinical diagnosis. It is necessary to evaluate the robustness of medical DNN tasks against adversarial attacks, as high-stake decision-making will be made based on the diagnosis. Several previous studies have considered simple adversarial attacks. However, the vulnerability of DNNs to more realistic and higher risk attacks, such as universal adversarial perturbation (UAP), which is a single perturbation that can induce DNN failure in most classification tasks has not been evaluated yet

    Topical Mevalonic Acid Stimulates De Novo Cholesterol Synthesis and Epidermal Permeability Barrier Homeostasis in Aged Mice11The authors did not submit a completed declaration of conflict of interest form as requested by the JID’s ‘‘Information for authors’’.

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    Extracellular lipids of the stratum corneum, which are composed of cholesterol, fatty acid, and ceramides, are essential for the epidermal permeability barrier function. With damage to the barrier, a decreased capacity for epidermal lipid biosynthesis in aged epidermis results in an impaired repair response. Mevalonic acid is an intermediate after the rate-limiting step in cholesterol biosynthesis, which is catalyzed by 3-hydroxy-3-methylglutaryl coenzyme A reductase. In the present study, we investigated the effect of topical mevalonic acid on the murine epidermal permeability barrier function, comparing it with that of cholesterol. Topical treatment with acetone caused linear increases in transepidermal water loss, in proportion to the number of treatments more rapidly in aged mice than in young mice. Administration of mevalonic acid on aged murine epidermis enhanced its resistance against damage and the recovery rate of barrier function from acute barrier disruption. In contrast, although cholesterol also had the same effect, it required a much higher amount than mevalonic acid. In young mice, neither mevalonic acid nor cholesterol had any effect on resistance against acetone damage nor the recovery rate from acetone damage. In the skin of mice topically administered with mevalonic acid, stimulation of cholesterol synthesis and 3-hydroxy-3-methylglutaryl coenzyme A reductase activity were both observed, whereas none was seen with stimulation by equimolar cholesterol. These data indicate that a topical application of mevalonic acid enhances barrier recovery in aged mice, which is accompanied by not only acceleration of cholesterol synthesis from mevalonic acid but also stimulation of the whole cholesterol biosynthesis

    Neurogenic Tumor of The Chest Wall: A

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    A rare case of schwannoma of the chest wall is presented. A 65-year-old Japanese man had a painful mass, measuring 3×3cm, in the 10th intercostal space of the right back. A fine needle biopsy seemed to fail to prove a nature of the tumor. A computed tomography (CT) scan of the chest showed a well-demarcated low density mass with no invasion to the ribs, lung and pleura with the CT density being 30 Hounsfield unit. These findings were suggestive of a neurogenic tumor. The tumor was easily extirpated and a histological diagnosis was schwannoma

    The effect of anastrozole on bone mineral density during the first 5 years of adjuvant treatment in postmenopausal women with early breast cancer

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    PURPOSE: The administration of aromatase inhibitors is associated with bone loss in postmenopausal women. We assessed changes in bone mineral density (BMD) from baseline to 60 months of treatment in patients receiving anastrozole as initial adjuvant therapy. METHODS: Postmenopausal women with hormone receptor-positive breast cancer receiving anastrozole as adjuvant therapy at our center since 2004 were enrolled in this study. BMD was assessed by dual-energy X-ray absorptiometry at baseline and after 6, 12, 24, 36, 48 and 60 months. Oral bisphosphonate (Bis) treatment was initiated when patients were diagnosed with osteoporosis having a T-score of −2.5 or lower. RESULTS: Fifty-five patients were enrolled in the study between 2004 and 2011, and the mean follow-up period was 53.6 months. Thirty-five patients were administered Bis (risedronate in 27 patients, alendronate in 8 patients). After 6 months of hormone therapy, BMD decreased by 0.5% from baseline at the lumbar spine (LS) and BMD decreased by 1.5% at the femoral neck (FN). However, BMD increased by 1.9% at the LS and BMD decreased by 1.5% at the FN for 60 months of treatment. In patients treated with upfront Bis (n = 19), 5.4% BMD increase from baseline was noted at the LS whereas in those without Bis (n = 21) BMD decreased by 4.3% from baseline within 24 months (P < 0.0001). Fractures were observed in 4 patients (7.3%), and 1 patient (1.8%) had a fragility fracture. CONCLUSIONS: Upfront treatment of Bis with anastrozole significantly increased BMD at the LS and an optimal use of Bis would not increase bone fractures. TRIAL REGISTRATION: UMIN000001757

    Truncated KCNQ1 mutant, A178fs/105, forms hetero-multimer channel with wild-type causing a dominant-negative suppression due to trafficking defect

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    AbstractWe identified a novel mutation Ala178fs/105 missing S3–S6 and C-terminus portions of KCNQ1 channel. Ala178fs/105-KCNQ1 expressed in COS-7 cells demonstrated no current expression. Co-expression with wild-type (WT) revealed a dominant-negative effect, which suggests the formation of hetero-multimer by mutant and WT. Confocal laser microscopy displayed intracellular retention of Ala178fs/105-KCNQ1 protein. Co-expression of the mutant and WT also increased intracellular retention of channel protein compared to WT alone. Our findings suggest a novel mechanism for LQT1 that the truncated S1–S2 KCNQ1 mutant forms hetero-multimer and cause a dominant-negative effect due to trafficking defect
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