157 research outputs found
Social Europe. No 2/87
BACKGROUND: DNA methylation is an important type of epigenetic modification involved in gene regulation. Although strong DNA methylation at promoters is widely recognized to be associated with transcriptional repression, many aspects of DNA methylation remain not fully understood, including the quantitative relationships between DNA methylation and expression levels, and the individual roles of promoter and gene body methylation. RESULTS: Here we present an integrated analysis of whole-genome bisulfite sequencing and RNA sequencing data from human samples and cell lines. We find that while promoter methylation inversely correlates with gene expression as generally observed, the repressive effect is clear only on genes with a very high DNA methylation level. By means of statistical modeling, we find that DNA methylation is indicative of the expression class of a gene in general, but gene body methylation is a better indicator than promoter methylation. These findings are general in that a model constructed from a sample or cell line could accurately fit the unseen data from another. We further find that promoter and gene body methylation have minimal redundancy, and either one is sufficient to signify low expression. Finally, we obtain increased modeling power by integrating histone modification data with the DNA methylation data, showing that neither type of information fully subsumes the other. CONCLUSION: Our results suggest that DNA methylation outside promoters also plays critical roles in gene regulation. Future studies on gene regulatory mechanisms and disease-associated differential methylation should pay more attention to DNA methylation at gene bodies and other non-promoter regions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13059-014-0408-0) contains supplementary material, which is available to authorized users
The photometric observation of the quasi-simultaneous mutual eclipse and occultation between Europa and Ganymede on 22 August 2021
Mutual events (MEs) are eclipses and occultations among planetary natural
satellites. Most of the time, eclipses and occultations occur separately.
However, the same satellite pair will exhibit an eclipse and an occultation
quasi-simultaneously under particular orbital configurations. This kind of rare
event is termed as a quasi-simultaneous mutual event (QSME). During the 2021
campaign of mutual events of jovian satellites, we observed a QSME between
Europa and Ganymede. The present study aims to describe and study the event in
detail. We observed the QSME with a CCD camera attached to a 300-mm telescope
at the Hong Kong Space Museum Sai Kung iObservatory. We obtained the combined
flux of Europa and Ganymede from aperture photometry. A geometric model was
developed to explain the light curve observed. Our results are compared with
theoretical predictions (O-C). We found that our simple geometric model can
explain the QSME fairly accurately, and the QSME light curve is a superposition
of the light curves of an eclipse and an occultation. Notably, the observed
flux drops are within 2.6% of the theoretical predictions. The size of the
event central time O-Cs ranges from -14.4 to 43.2 s. Both O-Cs of flux drop and
timing are comparable to other studies adopting more complicated models. Given
the event rarity, model simplicity and accuracy, we encourage more observations
and analysis on QSMEs to improve Solar System ephemerides.Comment: 23 pages, 5 appendixes, 16 figures, 7 table
The predictive value of G8 and the Cancer and aging research group chemotherapy toxicity tool in treatment-related toxicity in older Chinese patients with cancer
Introduction: Older patients experience a higher risk of treatment-related toxicity (TRT). The G8 screening tool was developed to separate cancer older patients fit to receive standard treatment from those who are frail and experiencing functional decline due to reduced organ function and multiple comorbidities. The Cancer and Aging Research Group chemotherapy toxicity tool (CARG-tt) questionnaire was developed to predict chemotherapy toxicity in geriatric patients. This prospective observational study evaluated the performance of G8 and CARG-tt in predicting severe TRT in older Chinese cancer patients. Methods: Chinese patients aged ≥65 with a diagnosis of solid malignancy and scheduled to receive anti-cancer treatment (chemotherapy or targeted therapy) were enrolled from March 2016 to July 2017 at the Department of Clinical Oncology at Queen Mary Hospital in Hong Kong. All patients completed the G8 and CARG-tt screening and pre-treatment assessments before starting treatment. Patients were monitored for any severe TRT, which was defined by grades 3–5 using the National Cancer Institute's Common Terminology Criteria for Adverse Events v4.03, treatment discontinuation, or unexpected hospitalization from starting to 30 days after treatment. Results: A total of 259 patients (male: 154, 59.5%; median age: 73.4, age range: 65–93) were enrolled in the study. Two hundred and ten (81.1%) patients received chemotherapy while the rest (n = 49, 18.9%) received targeted therapy. Overall, 146 patients (56.8%) experienced severe TRT. The mean G8 score was 12.4 (SD: 2.8). The G8 score had a significant association with unexpected admission (cutoff: 14, 41.3% vs. 26.5%, p = 0.03) but not significant in other types of TRTs. The mean CARG-tt score was 7.67 (SD: 3.7); it was not associated with severe TRTs. Conclusions: The G8 and CARG-tt demonstrated a weak prediction of severe TRT in older Chinese cancer patients. Future studies need to develop predictive tools for TRT in patients receiving novel antineoplastic therapies, with a focus on subgroup analysis for different populations
Poliserosite, artrite e doença respiratória em leitões: estudo de caso
O complexo da poliserosite em suĂnos Ă© causado por mĂşltiplos factores, em particular pelo agente Haemophilus parasuis (HPS), que tem vindo a causar vários problemas em suĂnos, quer ao nĂvel respiratĂłrio, quer nas articulações.
O agente HPS é o responsável pela Doença de Glässer (DG), caracterizada por uma inflamação generalizada da pleura, pericárdio, peritoneu, membranas sinoviais e meninges, acompanhada pela elevada presença de fibrina.
HPS Ă© normalmente um agente secundário causado por algum factor predisponente, como stress, pneumonias ou por algum vĂrus, em particular o VĂrus do SĂndrome RespiratĂłrio e Reprodutor Porcino (PRRSv).No caso das pneumonias verificou-se que o agente HPS Ă© um invasor secundário oportunista e que causa doença em associação com outros agentes vĂricos ou bacterianos e está associado com maior prevalĂŞncia de pneumonia por agentes respiratĂłrios vĂricos, como o SĂndrome RespiratĂłrio e Reprodutor Porcino (PRRS).
Durante este estudo de caso acompanhou-se um lote de leitões desde o desmame atĂ© ao final da recria, em que foram feitas serologias e enviados leitões inteiros para laboratĂłrio de forma a isolar e identificar o agente. Foi feita a avaliação da morbilidade bem como o cálculo do Ăndice de tosse e taxa de mortalidade nas primeiras quatro semanas de recria. Efectuaram-se necropsias dos leitões deste lote.
Pretende-se, como objectivo deste estudo, definir o agente primário causador da patologia, neste caso o PRRSv, bem como a entrada da infecção bacteriana secundária causada pelo HPS.
Procedeu-se à vacinação do efectivo frente ao PRRSv.
Como profilaxia, devido à falha de protecção de imunidade maternal, fez-se a administração de tulatromicina a todos os leitões até todo o efectivo estar devidamente protegido frente ao PRRSv, conferindo assim uma boa imunidade maternal.The porcine polyserositis complex is caused by multiple factors, particularly by Haemophilus parasuis (HPS), which has been causing several problems in pigs, both at the respiratory and articular levels. HPS is the causative agent of Glässer's Disease (DG), characterized by a generalized inflammation of the pleura, pericardium, peritoneum, synovial membranes and meninges, toguether with an abundant presence of fibrin. HPS is usually a secondary agent enhanced by some predisposing factor, like stress, pneumonia or some viruses, such as Porcine Reproductive and Respiratory Syndrome virus (PRRSv). In pneumonia, it has been show that HPS is an opportunistic secondary invader causing disease in association with other viral or bacterial agents being PRRSv the most prevalent respiratory viral agent found together with HPS. During this study a batch of piglets was followed from weaning until the end of nursery season, when serologies were performed, samples were collected and whole piglets were sent to pathology in order to isolate and identify the agent. Health condition was evaluated as well as the calculation of cough index and mortality rate in the first four weeks of nursery. Necropsies of the piglets of this batch were also carried out.The objective of this study was to define the primary agent causing disease (in this case PRRSv), as well as the factors that predisposed to secondary bacterial infections caused by HPS. Following these findings all herd was vaccinated against PRRSv. Due to lack of protective maternal immunity, tulathromycin was administered in pigs, as prophylactic measure until all sows were adequately protected against PRRSv, thus conferring good maternal immunity to their offspring
Acute renal impairment in coronavirus-associated severe acute respiratory syndrome
Acute renal impairment in coronavirus-associated severe acute respiratory syndrome.BackgroundSevere acute respiratory syndrome (SARS) is a newly emerged infection from a novel coronavirus (SARS-CoV). Apart from fever and respiratory complications, acute renal impairment has been observed in some patients with SARS. Herein, we describe the clinical, pathologic, and laboratory features of the acute renal impairment complicating this new viral infection.MethodsWe conducted a retrospective analysis of the plasma creatinine concentration and other clinical parameters of the 536 SARS patients with normal plasma creatinine at first clinical presentation, admitted to two regional hospitals following a major outbreak in Hong Kong in March 2003. Kidney tissues from seven other patients with postmortem examinations were studied by light microscopy and electron microscopy.ResultsAmong these 536 patients with SARS, 36 (6.7%) developed acute renal impairment occurring at a median duration of 20 days (range 5–48 days) after the onset of viral infection despite a normal plasma creatinine level at first clinical presentation. The acute renal impairment reflected the different prerenal and renal factors that exerted renal insult occurring in the context of multiorgan failure. Eventually, 33 SARS patients (91.7%) with acute renal impairment died. The mortality rate was significantly higher among patients with SARS and acute renal impairment compared with those with SARS and no renal impairment (91.7% vs. 8.8%) (P < 0.0001). Renal tissues revealed predominantly acute tubular necrosis with no evidence of glomerular pathology. The adjusted relative risk of mortality associated with the development of acute renal impairment was 4.057 (P < 0.001). By multivariate analysis, acute respiratory distress syndrome and age were the most significant independent risk factors predicting the development of acute renal impairment in SARS.ConclusionAcute renal impairment is uncommon in SARS but carries a high mortality. The acute renal impairment is likely to be related to multi-organ failure rather than the kidney tropism of the virus. The development of acute renal impairment is an important negative prognostic indicator for survival with SARS
Chronic adiponectin deficiency leads to Alzheimer’s disease-like cognitive impairments and pathologies through AMPK inactivation and cerebral insulin resistance in aged mice
(a) Immunoblotting analysis of IRβ in the hippocampus and frontal cortex of 18-month old wildtype and APN-KO mice. (b) Densitometric analysis of the ratio of IRβ. Mean ± S.E.M.; ***p < 0.001, n.s. statistically not significant; Scale bar: 100 μm. (JPG 30 kb
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Repurposing hyperpolarization-activated cyclic nucleotide-gated channels as a novel therapy for breast cancer.
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are members of the voltage-gated cation channel family known to be expressed in the heart and central nervous system. Ivabradine, a small molecule HCN channel-blocker, is FDA-approved for clinical use as a heart rate-reducing agent. We found that HCN2 and HCN3 are overexpressed in breast cancer cells compared with normal breast epithelia, and the high expression of HCN2 and HCN3 is associated with poorer survival in breast cancer patients. Inhibition of HCN by Ivabradine or by RNAi, aborted breast cancer cell proliferation in vitro and suppressed tumour growth in patient-derived tumour xenograft models established from triple-negative breast cancer (TNBC) tissues, with no evident side-effects on the mice. Transcriptome-wide analysis showed enrichment for cholesterol metabolism and biosynthesis as well as lipid metabolism pathways associated with ER-stress following Ivabradine treatment. Mechanistic studies confirmed that HCN inhibition leads to ER-stress, in part due to disturbed Ca2+ homeostasis, which subsequently triggered the apoptosis cascade. More importantly, we investigated the synergistic effect of Ivabradine and paclitaxel on TNBC and confirmed that both drugs acted synergistically in vitro through ER-stress to amplify signals for caspase activation. Combination therapy could suppress tumour growth of xenografts at much lower doses for both drugs. In summary, our study identified a new molecular target with potential for being developed into targeted therapy, providing scientific grounds for initiating clinical trials for a new treatment regimen of combining HCN inhibition with chemotherapy
Identification of microbial community in the urban environment: The concordance between conventional culture and nanopore 16S rRNA sequencing
IntroductionMicrobes in the built environment have been implicated as a source of infectious diseases. Bacterial culture is the standard method for assessing the risk of exposure to pathogens in urban environments, but this method only accounts for <1% of the diversity of bacteria. Recently, full-length 16S rRNA gene analysis using nanopore sequencing has been applied for microbial evaluations, resulting in a rise in the development of long-read taxonomic tools for species-level classification. Regarding their comparative performance, there is, however, a lack of information.MethodsHere, we aim to analyze the concordance of the microbial community in the urban environment inferred by multiple taxonomic classifiers, including ARGpore2, Emu, Kraken2/Bracken and NanoCLUST, using our 16S-nanopore dataset generated by MegaBLAST, as well as assess their abilities to identify culturable species based on the conventional culture results.ResultsAccording to our results, NanoCLUST was preferred for 16S microbial profiling because it had a high concordance of dominant species and a similar microbial profile to MegaBLAST, whereas Kraken2/Bracken, which had similar clustering results as NanoCLUST, was also desirable. Second, for culturable species identification, Emu with the highest accuracy (81.2%) and F1 score (29%) for the detection of culturable species was suggested.DiscussionIn addition to generating datasets in complex communities for future benchmarking studies, our comprehensive evaluation of the taxonomic classifiers offers recommendations for ongoing microbial community research, particularly for complex communities using nanopore 16S rRNA sequencing
Carboxyl-terminal truncated HBx regulates a distinct microRNA transcription program in Hepatocellular carcinoma development
Background: The biological pathways and functional properties by which misexpressed microRNAs (miRNAs) contribute to liver carcinogenesis have been intensively investigated. However, little is known about the upstream mechanisms that deregulate miRNA expressions in this process. In hepatocellular carcinoma (HCC), hepatitis B virus (HBV) X protein (HBx), a transcriptional trans-activator, is frequently expressed in truncated form without carboxyl-terminus but its role in miRNA expression and HCC development is unclear. Methods: Human non-tumorigenic hepatocytes were infected with lentivirus-expressing full-length and carboxyl-terminal truncated HBx (Ct-HBx) for cell growth assay and miRNA profiling. Chromatin immunoprecipitation microarray was performed to identify the miRNA promoters directly associated with HBx. Direct transcriptional control was verified by luciferase reporter assay. The differential miRNA expressions were further validated in a cohort of HBV-associated HCC tissues using real-time PCR. Results: Hepatocytes expressing Ct-HBx grew significantly faster than the full-length HBx counterparts. Ct-HBx decreased while full-length HBx increased the expression of a set of miRNAs with growth-suppressive functions. Interestingly, Ct-HBx bound to and inhibited the transcriptional activity of some of these miRNA promoters. Notably, some of the examined repressed-miRNAs (miR-26a, -29c, -146a and -190) were also significantly down-regulated in a subset of HCC tissues with carboxyl-terminal HBx truncation compared to their matching non-tumor tissues, highlighting the clinical relevance of our data. Conclusion: Our results suggest that Ct-HBx directly regulates miRNA transcription and in turn promotes hepatocellular proliferation, thus revealing a viral contribution of miRNA deregulation during hepatocarcinogenesis. © 2011 Yip et al.published_or_final_versio
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