2,110 research outputs found

    A critical look at studies applying over-sampling on the TPEHGDB dataset

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    Preterm birth is the leading cause of death among young children and has a large prevalence globally. Machine learning models, based on features extracted from clinical sources such as electronic patient files, yield promising results. In this study, we review similar studies that constructed predictive models based on a publicly available dataset, called the Term-Preterm EHG Database (TPEHGDB), which contains electrohysterogram signals on top of clinical data. These studies often report near-perfect prediction results, by applying over-sampling as a means of data augmentation. We reconstruct these results to show that they can only be achieved when data augmentation is applied on the entire dataset prior to partitioning into training and testing set. This results in (i) samples that are highly correlated to data points from the test set are introduced and added to the training set, and (ii) artificial samples that are highly correlated to points from the training set being added to the test set. Many previously reported results therefore carry little meaning in terms of the actual effectiveness of the model in making predictions on unseen data in a real-world setting. After focusing on the danger of applying over-sampling strategies before data partitioning, we present a realistic baseline for the TPEHGDB dataset and show how the predictive performance and clinical use can be improved by incorporating features from electrohysterogram sensors and by applying over-sampling on the training set

    Steps in the bacterial flagellar motor

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    The bacterial flagellar motor is a highly efficient rotary machine used by many bacteria to propel themselves. It has recently been shown that at low speeds its rotation proceeds in steps [Sowa et al. (2005) Nature 437, 916--919]. Here we propose a simple physical model that accounts for this stepping behavior as a random walk in a tilted corrugated potential that combines torque and contact forces. We argue that the absolute angular position of the rotor is crucial for understanding step properties, and show this hypothesis to be consistent with the available data, in particular the observation that backward steps are smaller on average than forward steps. Our model also predicts a sublinear torque-speed relationship at low torque, and a peak in rotor diffusion as a function of torque

    Connective tissue disease related interstitial lung diseases and idiopathic pulmonary fibrosis: provisional core sets of domains and instruments for use in clinical trials

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    Rationale Clinical trial design in interstitial lung diseases (ILDs) has been hampered by lack of consensus on appropriate outcome measures for reliably assessing treatment response. In the setting of connective tissue diseases (CTDs), some measures of ILD disease activity and severity may be confounded by non-pulmonary comorbidities. Methods The Connective Tissue Disease associated Interstitial Lung Disease (CTD-ILD) working group of Outcome Measures in Rheumatology—a non-profit international organisation dedicated to consensus methodology in identification of outcome measures—conducted a series of investigations which included a Delphi process including >248 ILD medical experts as well as patient focus groups culminating in a nominal group panel of ILD experts and patients. The goal was to define and develop a consensus on the status of outcome measure candidates for use in randomised controlled trials in CTD-ILD and idiopathic pulmonary fibrosis (IPF). Results A core set comprising specific measures in the domains of lung physiology, lung imaging, survival, dyspnoea, cough and health-related quality of life is proposed as appropriate for consideration for use in a hypothetical 1-year multicentre clinical trial for either CTD-ILD or IPF. As many widely used instruments were found to lack full validation, an agenda for future research is proposed. Conclusion Identification of consensus preliminary domains and instruments to measure them was attained and is a major advance anticipated to facilitate multicentre RCTs in the field

    Determining the HPV vaccine schedule for a HIV-infected population in sub Saharan Africa, a commentary

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    Background: Epidemiological studies have established human papillomavirus (HPV) infection as the central cause of invasive cervical cancer (ICC) and its precursor lesions. HIV is associated with a higher prevalence and persistence of a broader range of high-risk HPV genotypes, which in turn results in a higher risk of cervical disease. Recent WHO HPV vaccination schedule recommendations, along with the roll out of HAART at an earlier CD4 count within the female HIV-infected population, may have programmatic implications for sub Saharan Africa. This communication identifies research areas, which will need to be addressed for determining a HPV vaccine schedule for this population in sub Saharan Africa. A review of WHO latest recommendations and the evidence concerning one-dose HPV vaccine schedules was undertaken. Conclusion: For females >= 15 years at the time of first dose and immunocompromised and/or HIV-infected, a 3-dose schedule (0, 1-2, 6 months) is recommended for all three vaccines. There is some evidence that there is similar protection against HPV 16 and 18 infection from a single vaccination than from two or three doses, however there is no cross protection conferred to other genotypes. There is a need for periodic prevalence studies to determine the vaccination coverage of bivalent, quadrivalent and nonavalent vaccine targeted oncogenic HPV genotypes in women with CIN 3 or ICC at national level. In light of the increasing number of sub Saharan HIV-infected girls initiating HAART at a CD4 count above 350 mm(3), there are a number of clinical, virological and public health research gaps to address before a tailored vaccine schedule can be established for this population

    Translation initiation mediated by RNA looping

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    Eukaryotic translation initiation commences at the initiation codon near the 5' end of mRNA by a 40S ribosomal subunit, and the recruitment of a 40S ribosome to an mRNA is facilitated by translation initiation factors interacting with the m7G cap and/or poly (A) tail. The 40S ribosome recruited to an mRNA is then transferred to the AUG initiation codon with the help of translation initiation factors. To understand the mechanism by which the ribosome finds an initiation codon, we investigated the role of eIF4G in finding the translational initiation codon. An artificial polypeptide eIF4G fused with MS2 was localized downstream of the reporter gene through MS2-binding sites inserted in the 3' UTR of the mRNA. Translation of the reporter was greatly enhanced by the eIF4G-MS2 fusion protein regardless of the presence of a cap structure. Moreover, eIF4G-MS2 tethered at the 3' UTR enhanced translation of the second cistron of a dicistronic mRNA. The encephalomyocarditis virus internal ribosome entry site, a natural translational-enhancing element facilitating translation through an interaction with eIF4G, positioned downstream of a reporter gene, also enhanced translation of the upstream gene in a cap-independent manner. Finally, we mathematically modeled the effect of distance between the cap structure and initiation codon on the translation efficiency of mRNAs. The most plausible explanation for translational enhancement by the translational-enhancing sites is recognition of the initiation codon by the ribosome bound to the ribosome-recruiting sites through "RNA looping." The RNA looping hypothesis provides a logical explanation for augmentation of translation by enhancing elements located upstream and/or downstream of a protein-coding region.open112122sciescopu

    Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice

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    BACKGROUND: An epidemiological study conducted in Italy indicated that coffee has the greatest antioxidant capacity among the commonly consumed beverages. Green coffee bean is rich in chlorogenic acid and its related compounds. The effect of green coffee bean extract (GCBE) on fat accumulation and body weight in mice was assessed with the objective of investigating the effect of GCBE on mild obesity. METHODS: Male ddy mice were fed a standard diet containing GCBE and its principal constituents, namely, caffeine and chlorogenic acid, for 14 days. Further, hepatic triglyceride (TG) level was also investigated after consecutive administration (13 days) of GCBE and its constituents. To examine the effect of GCBE and its constituents on fat absorption, serum TG changes were evaluated in olive oil-loaded mice. In addition, to investigate the effect on hepatic TG metabolism, carnitine palmitoyltransferase (CPT) activity in mice was evaluated after consecutive ingestion (6 days) of GCBE and its constituents (caffeine, chlorogenic acid, neochlorogenic acid and feruloylquinic acid mixture). RESULTS: It was found that 0.5% and 1% GCBE reduced visceral fat content and body weight. Caffeine and chlorogenic acid showed a tendency to reduce visceral fat and body weight. Oral administration of GCBE (100 and 200 mg/kg· day) for 13 days showed a tendency to reduce hepatic TG in mice. In the same model, chlorogenic acid (60 mg/kg· day) reduced hepatic TG level. In mice loaded with olive oil (5 mL/kg), GCBE (200 and 400 mg/kg) and caffeine (20 and 40 mg/kg) reduced serum TG level. GCBE (1%), neochlorogenic acid (0.028% and 0.055%) and feruloylquinic acid mixture (0.081%) significantly enhanced hepatic CPT activity in mice. However, neither caffeine nor chlorogenic acid alone was found to enhance CPT activity. CONCLUSION: These results suggest that GCBE is possibly effective against weight gain and fat accumulation by inhibition of fat absorption and activation of fat metabolism in the liver. Caffeine was found to be a suppressor of fat absorption, while chlorogenic acid was found to be partially involved in the suppressive effect of GCBE that resulted in the reduction of hepatic TG level. Phenolic compounds such as neochlorogenic acid and feruloylquinic acid mixture, except chlorogenic acid, can enhance hepatic CPT activity

    Interleukin-1β sequesters hypoxia inducible factor 2α to the primary cilium.

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    BACKGROUND: The primary cilium coordinates signalling in development, health and disease. Previously we have shown that the cilium is essential for the anabolic response to loading and the inflammatory response to interleukin-1β (IL-1β). We have also shown the primary cilium elongates in response to IL-1β exposure. Both anabolic phenotype and inflammatory pathology are proposed to be dependent on hypoxia-inducible factor 2 alpha (HIF-2α). The present study tests the hypothesis that an association exists between the primary cilium and HIFs in inflammatory signalling. RESULTS: Here we show, in articular chondrocytes, that IL-1β-induces primary cilia elongation with alterations to cilia trafficking of arl13b. This elongation is associated with a transient increase in HIF-2α expression and accumulation in the primary cilium. Prolyl hydroxylase inhibition results in primary cilia elongation also associated with accumulation of HIF-2α in the ciliary base and axoneme. This recruitment and the associated cilia elongation is not inhibited by blockade of HIFα transcription activity or rescue of basal HIF-2α expression. Hypomorphic mutation to intraflagellar transport protein IFT88 results in limited ciliogenesis. This is associated with increased HIF-2α expression and inhibited response to prolyl hydroxylase inhibition. CONCLUSIONS: These findings suggest that ciliary sequestration of HIF-2α provides negative regulation of HIF-2α expression and potentially activity. This study indicates, for the first time, that the primary cilium regulates HIF signalling during inflammation

    Prognostic parameters for recurrence of papillary thyroid microcarcinoma

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    <p>Abstract</p> <p>Background</p> <p>Papillary thyroid microcarcinoma (PTMC) is defined as a papillary thyroid carcinoma less than or equal to 1.0 cm in size. Independent prognostic factors for clinical recurrence of PTMC have not been clearly delineated.</p> <p>Methods</p> <p>Clinicopathological parameters predicting PTMC recurrence were determined by retrospective analysis of 307 patients.</p> <p>Results</p> <p>Of the 293 patients eligible for analysis, 14 (5%) had recurrence during a median follow-up time of 65 months. Recurrence was observed in 8 of 166 patients (0.5%) treated with total or near-total thyroidectomy; gender (P = 0.02) and presence of lateral cervical node metastases at initial surgery (P = 0.01) were associated with recurrence. Six of the 127 patients (0.5%) treated with hemi- or subtotal thyroidectomy experience recurrences, but no significant prognostic factor for recurrence was identified. Multivariate Cox-regression analysis showed that gender and cervical lymph node metastasis were significant variables</p> <p>Conclusion</p> <p>PTMC showed very diverse disease extent and could not be regarded as indolent, relatively benign disease based on the primary tumor size. The extent of surgery should be based on prognostic parameters, such as gender and lateral neck node metastasis, in patients with PTMC.</p
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