1,289 research outputs found
2D-Based 3D Volume Retrieval Using Singular Value Decomposition of Detected Regions
In this paper, a novel 3D retrieval model to retrieve medical volumes using 2D images as input is proposed. The main idea consists of applying a multiâscale detection of saliency of image regions. Then, the 3D volumes with the regions for each of the scales are associated with a set of projections onto the three canonical planes. The 3D shape is indirectly represented by a 2Dâshape descriptor so that the 3Dâshape matching is transformed into measuring similarity between 2Dâshapes. The shape descriptor is defined by the set of the k largest singular values of the 2D images and Euclidean distance between the vector descriptors is used as a similarity measure. The preliminary results obtained on a simple database show promising performance with a mean average precision (MAP) of 0.82 and could allow using the approach as part of a retrieval system in clinical routine
Postherpetic Neuralgia: Role of Gabapentin and Other Treatment Modalities
Postherpetic neuralgia (PHN) is a chronic and painful condition that may occur after a herpes zoster infection. The frequency of PHN after untreated zoster varies widely. Age is the most important risk factor for development of PHN. The condition occurs in an estimated 50% of patients older than 50 years. The pain of PHN can be severe and debilitating and is frequently associated with allodynia. Although in most patients pain remits within the first year, it may persist for a lifetime. Tricyclic antidepressants (TCAs), topical agents, opioids, and gabapentin, a structural Î-amino butyric acid (GABA) analogue, are the only agents that have demonstrated efficacy in randomized clinical trials for treatment of both the shooting and the burning form of pain associated with PHN. TCAs are among the most commonly used classes of agents for treating PHN and are effective in a significant proportion of patients. However, various adverse events can limit treatment. These side effects tend to be more acute in the elderly, the population most likely to suffer from PHN. Topical agents have led to mild to moderate improvement in patients with PHN but are usually ineffective as monotherapy for this condition. Until recently, carbamazepine was the only antiepileptic drug evaluated for the treatment of PHN. Over the past few years, however, gabapentin has received increasing attention as a useful treatment for neuropathic pain. Gabapentin lacks significant drug-drug interactions and has a favorable safety profile, which makes it particularly useful for treatment of PHN.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65597/1/j.1528-1157.1999.tb00933.x.pd
Computational identification of condition-specific miRNA targets based on gene expression profiles and sequence information
<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are small and noncoding RNAs that play important roles in various biological processes. They regulate target mRNAs post-transcriptionally through complementary base pairing. Since the changes of miRNAs affect the expression of target genes, the expression levels of target genes in specific biological processes could be different from those of non-target genes. Here we demonstrate that gene expression profiles contain useful information in separating miRNA targets from non-targets.</p> <p>Results</p> <p>The gene expression profiles related to various developmental processes and stresses, as well as the sequences of miRNAs and mRNAs in <it>Arabidopsis</it>, were used to determine whether a given gene is a miRNA target. It is based on the model combining the support vector machine (SVM) classifier and the scoring method based on complementary base pairing between miRNAs and mRNAs. The proposed model yielded low false positive rate and retrieved condition-specific candidate targets through a genome-wide screening.</p> <p>Conclusion</p> <p>Our approach provides a novel framework into screening target genes by considering the gene regulation of miRNAs. It can be broadly applied to identify condition-specific targets computationally by embedding information of gene expression profiles.</p
Serotonin and corticosterone rhythms in mice exposed to cigarette smoke and in patients with COPD:implication for COPD-associated neuropathogenesis
The circadian timing system controls daily rhythms of physiology and behavior, and disruption of clock function can trigger stressful life events. Daily exposure to cigarette smoke (CS) can lead to alteration in diverse biological and physiological processes. Smoking is associated with mood disorders, including depression and anxiety. Patients with chronic obstructive pulmonary disease (COPD) have abnormal circadian rhythms, reflected by daily changes in respiratory symptoms and lung function. Corticosterone (CORT) is an adrenal steroid that plays a considerable role in stress and anti-inflammatory responses. Serotonin (5-hydroxytryptamine; 5HT) is a neurohormone, which plays a role in sleep/wake regulation and affective disorders. Secretion of stress hormones (CORT and 5HT) is under the control of the circadian clock in the suprachiasmatic nucleus. Since smoking is a contributing factor in the development of COPD, we hypothesize that CS can affect circadian rhythms of CORT and 5HT secretion leading to sleep and mood disorders in smokers and patients with COPD. We measured the daily rhythms of plasma CORT and 5HT in mice following acute (3 d), sub-chronic (10 d) or chronic (6 mo) CS exposure and in plasma from non-smokers, smokers and patients with COPD. Acute and chronic CS exposure affected both the timing (peak phase) and amplitude of the daily rhythm of plasma CORT and 5HT in mice. Acute CS appeared to have subtle time-dependent effects on CORT levels but more pronounced effects on 5HT. As compared with CORT, plasma 5HT was slightly elevated in smokers but was reduced in patients with COPD. Thus, the effects of CS on plasma 5HT were consistent between mice and patients with COPD. Together, these data reveal a significant impact of CS exposure on rhythms of stress hormone secretion and subsequent detrimental effects on cognitive function, depression-like behavior, mood/anxiety and sleep quality in smokers and patients with COPD
Shear capacity of reinforced concrete corbels using mechanism analysis
A mechanism analysis is developed to predict the shear capacity of reinforced concrete corbels. Based on shear failure observed in experimental tests, kinematically admissible failure mechanisms are idealised as an assemblage of two rigid blocks separated by a failure plane of displacement discontinuity. Shear capacity predictions obtained from the developed mechanism analysis are in better agreement with corbel test results of a comprehensive database compiled from the available literature than other existing models for corbels. The developed mechanism model shows that the shear capacity of corbels generally decreases with the increase of shear span-to-depth ratio, increases with the increase of main longitudinal reinforcement up to a certain limit beyond which it remains constant, and decreases with the increase of horizontal applied loads. It also demonstrates that the smaller the shear span-to-overall depth ratio of corbels, the more effective the horizontal shear reinforcement
Neuronal circuitry for pain processing in the dorsal horn
Neurons in the spinal dorsal horn process sensory information, which is then transmitted to several brain regions, including those responsible for pain perception. The dorsal horn provides numerous potential targets for the development of novel analgesics and is thought to undergo changes that contribute to the exaggerated pain felt after nerve injury and inflammation. Despite its obvious importance, we still know little about the neuronal circuits that process sensory information, mainly because of the heterogeneity of the various neuronal components that make up these circuits. Recent studies have begun to shed light on the neuronal organization and circuitry of this complex region
Clinical Presentation of Hepatocellular Carcinoma (HCC) in Asian-Americans Versus Non-Asian-Americans
The incidence of HCC is rising worldwide. Studies on ethnicity-based clinical presentation of HCC remain limited. The aim is to compare the clinical presentation and stage of HCC between Asian-Americans and non-Asian-Americans. This retrospective study assessed ethnicity-based differences in HCC presentation, including demographics, laboratory results, diagnosis of underlying liver disease, and stage of HCC. Of 276 patients, 162 were Asian-Americans and 114 were non-Asian-Americans. Compared to non-Asian-Americans, Asian-Americans had a significantly higher incidence of history of hepatitis B virus (HBV) infection (55.0% vs. 4.9%, P < 0.001), family history of HBV infection (12.5% vs. 0.0%, P < 0.001) and HCC (15.2% vs. 2.9%, P = 0.002), but lower incidence of history of hepatitis C virus (HCV) infection (37.5% vs. 61.6%, P < 0.001). At diagnosis of HCC, Asian-American patients had a significantly lower frequency of hepatic encephalopathy (8.9% vs. 29.3%, P = 0.001), and ascites (26.7% vs. 57.3%, P < 0.001). Asian-Americans had lower Child-Pugh scores (class A: 62.0% vs. 31.4%, P < 0.001), and MELD scores (9.2 ¹ 4.4 vs. 12.0 ¹ 6.4, P = 0.02), and presented with a lower stage of HCC by Okuda staging (I: 43.8% vs. 22.8%, P = 0.001). Asian-American patients with HCC presented with a higher incidence of history and family history of HBV infection, lower incidence of hepatic decompensation, lower Child and MELD scores, and an early stage HCC disease
Gestational Diabetes Is Characterized by Reduced Mitochondrial Protein Expression and Altered Calcium Signaling Proteins in Skeletal Muscle
The rising prevalence of gestational diabetes mellitus (GDM) affects up to 18% of pregnant women with immediate and long-term metabolic consequences for both mother and infant. Abnormal glucose uptake and lipid oxidation are hallmark features of GDM prompting us to use an exploratory proteomics approach to investigate the cellular mechanisms underlying differences in skeletal muscle metabolism between obese pregnant women with GDM (OGDM) and obese pregnant women with normal glucose tolerance (ONGT). Functional validation was performed in a second cohort of obese OGDM and ONGT pregnant women. Quantitative proteomic analysis in rectus abdominus skeletal muscle tissue collected at delivery revealed reduced protein content of mitochondrial complex I (C-I) subunits (NDUFS3, NDUFV2) and altered content of proteins involved in calcium homeostasis/signaling (calcineurin A, ĂÂą1-syntrophin, annexin A4) in OGDM (nââŹĹ =ââŹĹ 6) vs. ONGT (nââŹĹ =ââŹĹ 6). Follow-up analyses showed reduced enzymatic activity of mitochondrial complexes C-I, C-III, and C-IV (âËâ60ââŹâ75%) in the OGDM (nââŹĹ =ââŹĹ 8) compared with ONGT (nââŹĹ =ââŹĹ 10) subjects, though no differences were observed for mitochondrial complex protein content. Upstream regulators of mitochondrial biogenesis and oxidative phosphorylation were not different between groups. However, AMPK phosphorylation was dramatically reduced by 75% in the OGDM women. These data suggest that GDM is associated with reduced skeletal muscle oxidative phosphorylation and disordered calcium homeostasis. These relationships deserve further attention as they may represent novel risk factors for development of GDM and may have implications on the effectiveness of physical activity interventions on both treatment strategies for GDM and for prevention of type 2 diabetes postpartum
Normal Leptin Expression, Lower Adipogenic Ability, Decreased Leptin Receptor and Hyposensitivity to Leptin in Adolescent Idiopathic Scoliosis
Leptin has been suggested to play a role in the etiology of Adolescent Idiopathic Scoliosis (AIS), however, the leptin levels in AIS girls are still a discrepancy, and no in vitro study of leptin in AIS is reported. We took a series of case-control studies, trying to understand whether Leptin gene polymorphisms are involved in the etiology of the AIS or the change in leptin level is a secondary event, to assess the level of leptin receptor, and to evaluate the differences of response to leptin between AIS cases and controls. We screened all exons of Leptin gene in 45 cases and 45 controls and selected six tag SNPs to cover all the observed variations. Association analysis in 446 AIS patients and 550 healthy controls showed no association between the polymorphisms of Leptin gene and susceptibility/severity to AIS. Moreover, adipogenesis assay of bone mesenchymal stem cells (MSCs) suggested that the adipogenic ability of MSCs from AIS girls was lower than controls. After adjusting the differentiation rate, expressions of leptin and leptin receptor were similar between two groups. Meanwhile, osteogenesis assay of MSC showed the leptin level was similar after adjusting the differentiation rate, but the leptin receptor level was decreased in induced AIS osteoblasts. Immunocytochemistry and western blot analysis showed less leptin receptors expressed in AIS group. Furthermore, factorial designed studies with adipogenesis and osteogenesis revealed that the MSCs from patients have no response to leptin treatment. Our results suggested that Leptin gene variations are not associated with AIS and low serum leptin probably is a secondary outcome which may be related to the low capability of adipogenesis in AIS. The decreased leptin receptor levels may lead to the hyposensitivity to leptin. These findings implied that abnormal peripheral leptin signaling plays an important role in the pathological mechanism of AIS
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