5,610 research outputs found

    NodeTrix Planarity Testing with Small Clusters

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    We study the NodeTrix planarity testing problem for flat clustered graphs when the maximum size of each cluster is bounded by a constant kk. We consider both the case when the sides of the matrices to which the edges are incident are fixed and the case when they can be chosen arbitrarily. We show that NodeTrix planarity testing with fixed sides can be solved in O(k3k+32n)O(k^{3k+\frac{3}{2}} \cdot n) time for every flat clustered graph that can be reduced to a partial 2-tree by collapsing its clusters into single vertices. In the general case, NodeTrix planarity testing with fixed sides can be solved in O(n)O(n) time for k=2k = 2, but it is NP-complete for any k>2k > 2. NodeTrix planarity testing remains NP-complete also in the free sides model when k>4k > 4.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

    A case of acanthosis nigricans in a HIV-infected patient

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    Background: To date, very little information is available concerning the relationship between acanthosis nigricans (AN) and infection with human immunodeficiency virus type 1 (HIV-1). Case presentation: Herein, we report the case of a middle-aged man admitted for fever and progressively worsening dyspnea in the context of an opportunistic pneumonia and firstly diagnosed with acquired immunodeficiency syndrome (AIDS). At the time of diagnosis, physical examination revealed the presence of a palpable, hyperpigmented skin lesion on the left areola with surface desquamation and velvety texture consistent with AN. Of note, the most common primary etiologies related to AN were excluded and the complete regression of the skin lesion was observed once antiretroviral therapy was started. Conclusion: This is the second report of AN found in patients with AIDS and apparently responsive to prolonged antiretroviral treatment. Possible explanations of this association are still not completely understood, probably related to virus-induced changes in lipid metabolism. Our experience suggests that HIV testing should always be considered in the setting of apparently idiopathic AN

    Intralabyrinthine Schwannoma of the Intravestibular Subtype: A Difficult Diagnosis

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    Intralabyrinthine schwannoma is a rare, slow-growing, benign tumor that affects the most terminal portions of the vestibular and cochlear nerves. It can be located in the vestibule, cochlea, or semicircular canals. In 2004, Kennedy et al proposed a classification system which recognized 7 subtypes of intralabyrinthine schwannoma; in 2013, Abel et al1 modified the Kennedy classification,2 which included intracochlear, intravestibular (IV), intravestibulocochlear, transmodiolar, transmacular, transotic, and tympanolabyrinthine, to also include translabyrinthine, tumors extending into the CPA, and tumors not otherwise specified. They also proposed to rename intralabyrinthine schwannoma as primary inner ear schwannoma to permit clear subsite categorization. Patients usually have nonspecific symptoms, including hearing loss, tinnitus, and only single episode of vertigo. Among the resulting symptoms, the most frequent is hearing loss, which affects 95% of the patients. Most times, this loss is slow and progressive, but it may be sudden or fluctuating. Less common symptoms include tinnitus (51%), imbalance (35%), vertigo (22%), and ear fullness (2%), which may be present alone or in combination.3-7 We report a rare case of a patient with hearing loss and single episode of vertigo secondary to the intralabyrinthine schwannoma of the IV subtype

    Lactate Threshold Training Program on Patients with Multiple Sclerosis: A Multidisciplinary Approach

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    Physical activity could play a key role in improving the quality of life, particularly in patients with nervous system diseases such as multiple sclerosis (MS). Through lactacid anaerobic training, this study aims to investigate the effects at a bio-psycho-physical level to counteract the chronic fatigue associated with the pathology, and to improve mental health at a psychological and neurotrophic level. Eight subjects (age: 34.88 ± 4.45 years) affected by multiple sclerosis were involved. A lactate threshold training program was administered biweekly for 12 weeks at the beginning of the study (T0), at the end of the study (T1) and at 9 months after the end of the study (T2), with physical, psychological and hematochemicals parameters, and dietary habits being tested. The results obtained confirmed that lactacid exercise can influence brain-derived neurotrophic factor (BDNF) levels as well as dehydroepiandrosterone sulfate (DHEAS) levels. In addition, levels of baseline lactate, which could be best used as an energy substrate, showed a decrease after the protocol training. Self-efficacy regarding worries and concerns management significantly increased from T0 to T1. The eating attitudes test (EAT-26) did not highlight any eating disease in the patients with a normal diet enrolled in our study. Physical exercise also greatly influenced the patients psychologically and emotionally, increasing their self-esteem. Lactate threshold training, together with dietary habits, appears to exert synergic positive effects on inflammation, neural plasticity and neuroprotection, producing preventive effects on MS symptoms and progressio

    Subtotal resection of vestibular schwannoma: evaluation with Ki-67 measurement, magnetic resonance imaging, and long-term observation

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    Purpose The aim of this study was to compare the postoperative clinical and radiological data of patients with vestibular schwannomas who were initially managed by near total resection (NTR) or subtotal resection (STR). The Ki-67 analysis results were compared with tumor regrowth to determine the presence of a correlation between this proliferative index and postoperative tumor regrowth. Study Design Seventeen adult patients (7 male, 10 female) were retrospectively reviewed. Nine (52.9%) and eight (47.1%) patients underwent NTR and STR, respectively. Postoperative clinical and radiological data associated with vestibular schwannoma growth were compared with the Ki-67 immunohistochemical analysis results. Results Evidence of clinically significant regrowth was observed in four (23.5%) patients. Patients who underwent NTR had a lower rate/incidence of tumor regrowth than did patients who underwent STR. Patients with a higher Ki-67 index had the highest tumor regrowth rates. Conclusions Our study indicates that assessment of the Ki-67 index may be useful for determining the probability of regrowth of vestibular schwannomas when only partial removal is accomplished

    Pediatric Stroke: Clinical Findings and Radiological Approach

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    This paper focuses on radiological approach in pediatric stroke including both ischemic stroke (Arterial Ischemic Stroke and Cerebral Sinovenous Thrombosis) and hemorrhagic stroke. Etiopathology and main clinical findings are examined as well. Magnetic Resonance Imaging could be considered as the first-choice diagnostic exam, offering a complete diagnostic set of information both in the discrimination between ischemic/hemorrhagic stroke and in the identification of underlying causes. In addition, Magnetic Resonance vascular techniques supply further information about cerebral arterial and venous circulation. Computed Tomography, for its limits and radiation exposure, should be used only when Magnetic Resonance is not available and on unstable patients
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