1,681 research outputs found
Stimulation of MCM helicase activity by a Cdc6 protein in the archaeon Thermoplasma acidophilum
Replicative DNA helicases are ring-shaped hexamers that play an essential role in chromosomal DNA replication. They unwind the two strands of the duplex DNA and provide the single-stranded (ss) DNA substrate for the polymerase. The minichromosome maintenance (MCM) proteins are thought to function as the replicative helicases in eukarya and archaea. The proteins of only a few archaeal organisms have been studied and revealed that although all have similar amino acid sequences and overall structures they differ in their biochemical properties. In this report the biochemical properties of the MCM protein from the archaeon Thermoplasma acidophilum is described. The enzyme has weak helicase activity on a substrate containing only a 3′-ssDNA overhang region and the protein requires a forked DNA structure for efficient helicase activity. It was also found that the helicase activity is stimulated by one of the two T.acidophilum Cdc6 homologues. This is an interesting observation as it is in sharp contrast to observations made with MCM and Cdc6 homologues from other archaea in which the helicase activity is inhibited when bound to Cdc6
Successful management of heterotopic cornual pregnancy with laparoscopic cornual resection
AbstractObjectiveTo examine the feasibility of laparoscopic cornual resection for the treatment of heterotopic cornual pregnancy.Study designWomen who underwent laparoscopic cornual resection for heterotopic cornual pregnancy at our hospital between January 2003 and March 2015 were retrospectively analyzed. We evaluated significant parameters such as operative complications and postoperative pregnancy outcomes of concomitant pregnancy.ResultsThirteen patients with heterotopic cornual pregnancy were included in the study. All were pregnant through assisted reproductive technology, and the diagnosis was made at a median of 6+6 weeks (range 5+4–10+0). They were successfully treated with laparoscopic cornual resection and admitted for a median of 4 days (range, 2–7) postoperatively. The median operative time was 65min (range, 35–145min) and estimated blood loss was 200mL (range, 10–3000mL). There was a spontaneous abortion at 7+6 gestational weeks in a patient who received bilateral cornual resection. Seven patients delivered babies at term and 3 at preterm. All 10 women delivered without any maternal or neonatal complications. Two were lost to follow-up.ConclusionsLaparoscopic cornual resection is a feasible primary approach for the management of heterotopic cornual pregnancy
Non-Invasive Epigenetic Detection of Fetal Trisomy 21 in First Trimester Maternal Plasma
BACKGROUND: Down syndrome (DS) is the most common known aneuploidy, caused by an extra copy of all or part of chromosome 21. Fetal-specific epigenetic markers have been investigated for non-invasive prenatal detection of fetal DS. The phosphodiesterases gene, PDE9A, located on chromosome 21q22.3, is completely methylated in blood (M-PDE9A) and unmethylated in the placenta (U-PDE9A). Therefore, we estimated the accuracy of non-invasive fetal DS detection during the first trimester of pregnancy using this tissue-specific epigenetic characteristic of PDE9A. METHODOLOGY/PRINCIPAL FINDINGS: A nested, case-control study was conducted using maternal plasma samples collected from 108 pregnant women carrying 18 DS and 90 normal fetuses (each case was matched with 5 controls according to gestational weeks at blood sampling). All pregnancies were singletons at or before 12 weeks of gestation between October 2008 and May 2009. The maternal plasma levels of M-PDE9A and U-PDE9A were measured by quantitative methylation-specific polymerase chain reaction. M-PDE9A and U-PDE9A levels were obtained in all samples and did not differ between male and female fetuses. M-PDE9A levels did not differ between the DS cases and controls (1854.3 vs 2004.5 copies/mL; P = 0.928). U-PDE9A levels were significantly elevated in women with DS fetuses compared with controls (356.8 vs 194.7 copies/mL, P<0.001). The sensitivities of U-PDE9A level and the unmethylation index of PDE9A for non-invasive fetal DS detection were 77.8% and 83.3%, respectively, with a 5% false-positive rate. In the risk assessment for fetal DS, the adjusted odds ratios of U-PDE9A level and UI were 46.2 [95% confidence interval: 7.8-151.6] and 63.7 [95% confidence interval: 23.2-206.7], respectively. CONCLUSIONS: Our findings suggest that U-PDE9A level and the unmethylation index of PDE9A may be useful biomarkers for non-invasive fetal DS detection during the first trimester of pregnancy, regardless of fetal gender
Quick Sepsis-related Organ Failure Assessment score is not sensitive enough to predict 28-day mortality in emergency department patients with sepsis: a retrospective review
Objective To test the hypothesis that the quick Sepsis-related Organ Failure Assessment (qSOFA) score, derived from vital signs taken during triage and recommended by current sepsis guidelines for screening patients with infections for organ dysfunction, is not sensitive enough to predict the risk of mortality in emergency department (ED) sepsis patients. Methods Patients diagnosed with severe sepsis and septic shock using the old definition between May 2014 and April 2015 were retrospectively reviewed in three urban tertiary hospital EDs. The sensitivities of systemic inflammatory response syndrome (SIRS) criteria, qSOFA, and Sequential Organ Failure Assessment (SOFA) scores ≥2 were compared using McNemar’s test. Diagnostic performances were evaluated using specificity, positive predictive value, and negative predictive value. Results Among the 928 patients diagnosed with severe sepsis or septic shock using the old definition, 231 (24.9%) died within 28 days. More than half of the sepsis patients (493/928, 53.1%) and more than one-third of the mortality cases (88/231, 38.1%) had a qSOFA score <2. The sensitivity of a qSOFA score ≥2 was 61.9%, which was significantly lower than the sensitivity of SIRS ≥2 (82.7%, P<0.001) and SOFA ≥2 (99.1%, P<0.001). The specificity, positive predictive value, and negative predictive value of a qSOFA score ≥2 for 28-day mortality were 58.1%, 32.9%, and 82.2%, respectively. Conclusion The current clinical criteria of the qSOFA are less sensitive than the SIRS assessment and SOFA to predict 28-day mortality in ED patients with sepsis
Association between hemoglobin glycation index and cardiometabolic risk factors in Korean pediatric nondiabetic population
Purpose The hemoglobin glycation index (HGI) represents the degree of nonenzymatic glycation and has been positively associated with cardiometabolic risk factors (CMRFs) and cardiovascular disease in adults. This study aimed to investigate the association between HGI, components of metabolic syndrome (MS), and alanine aminotransferase (ALT) in a pediatric nondiabetic population. Methods Data from 3,885 subjects aged 10–18 years from the Korea National Health and Nutrition Examination Survey (2011–2016) were included. HGI was defined as subtraction of predicted glycated hemoglobin (HbA1c) from measured HbA1c. Participants were divided into 3 groups according to HGI tertile. Components of MS (abdominal obesity, fasting glucose, triglycerides, high-density lipoprotein cholesterol, and blood pressure), and proportion of MS, CMRF clustering (≥2 of MS components), and elevated ALT were compared among the groups. Results Body mass index (BMI) z-score, obesity, total cholesterol, ALT, abdominal obesity, elevated triglycerides, and CMRF clustering showed increasing HGI trends from lower-to-higher tertiles. Multiple logistic regression analysis showed the upper HGI tertile was associated with elevated triglycerides (odds ratio, 1.65; 95% confidence interval, 1.18–2.30). Multiple linear regression analysis showed HGI level was significantly associated with BMI z-score, HbA1c, triglycerides, and ALT. When stratified by sex, age group, and BMI category, overweight/obese subjects showed linear HGI trends for presence of CMRF clustering and ALT elevation. Conclusions HGI was associated with CMRFs in a Korean pediatric population. High HGI might be an independent risk factor for CMRF clustering and ALT elevation in overweight/obese youth. Further studies are required to establish the clinical relevance of HGI for cardiometabolic health in youth
Gut taste receptor type 1 member 3 is an intrinsic regulator of Western diet-induced intestinal inflammation
Background
Long-term intake of a Western diet (WD), characterized by a high-fat content and sugary drinks, is hypothesized to contribute to the development of inflammatory bowel disease (IBD). Despite the identified clinical association, the molecular mechanisms by which dietary changes contribute to IBD development remain unknown. Therefore, we examined the influence of long-term intake of a WD on intestinal inflammation and the mechanisms by which WD intake affects IBD development.
Methods
Mice fed normal diet or WD for 10weeks, and bowel inflammation was evaluated through pathohistological and infiltrated inflammatory cell assessments. To understand the role of intestinal taste receptor type 1 member 3 (TAS1R3) in WD-induced intestinal inflammation, cultured enteroendocrine cells harboring TAS1R3, subjected to RNA interference or antagonist treatment, and Tas1r3-deficient mice were used. RNA-sequencing, flow cytometry, 16S metagenomic sequencing, and bioinformatics analyses were performed to examine the involved mechanisms. To demonstrate their clinical relevance, intestinal biopsies from patients with IBD and mice with dextran sulfate sodium-induced colitis were analyzed.
Results
Our study revealed for the first time that intestinal TAS1R3 is a critical mediator of WD-induced intestinal inflammation. WD-fed mice showed marked TAS1R3 overexpression with hallmarks of serious bowel inflammation. Conversely, mice lacking TAS1R3 failed to exhibit inflammatory responses to WD. Mechanistically, intestinal transcriptome analysis revealed that Tas1r3 deficiency suppressed mTOR signaling, significantly increasing the expression of PPARγ (a major mucosal defense enhancer) and upregulating the expression of PPARγ target-gene (tight junction protein and antimicrobial peptide). The gut microbiota of Tas1r3-deficient mice showed expansion of butyrate-producing Clostridia. Moreover, an increased expression of host PPARγ-signaling pathway proteins was positively correlated with butyrate-producing microbes, suggesting that intestinal TAS1R3 regulates the relationship between host metabolism and gut microflora in response to dietary factors. In cultured intestinal cells, regulation of the TAS1R3–mTOR–PPARγ axis was critical for triggering an inflammatory response via proinflammatory cytokine production and secretion. Abnormal regulation of the axis was observed in patients with IBD.
Conclusions
Our findings suggest that the TAS1R3–mTOR–PPARγ axis in the gut links Western diet consumption with intestinal inflammation and is a potential therapeutic target for IBD.This work was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education (Grant NRF-2021R1A2C3010280), and the Korea Mouse Phenotyping Project through the National Research Foundation of Korea funded by the Ministry of Science and ICT (Grant NRF-2013M3A9D5072550). The funding sources had no role in the design of the study, in the collection, analysis, and interpretation of data, or in the writing of the manuscrip
The Effect of Infliximab on Patients with Ulcerative Colitis in Korea
Background/AimsInfliximab was introduced recently as a rescue therapy for ulcerative colitis (UC) patients refractory to conventional treatments such as therapy with 5-amiono salicylic acids (5-ASA), immune modulators, and corticosteroids. However, there is insufficient data about its efficacy and safety in Korea.MethodsFrom 7 tertiary referral hospitals, 33 patients who were treated with infliximab for moderate to severe (Mayo score 6-12) UC refractory to conventional treatment were recruited to this study. Clinical remission was defined as a total Mayo score of 2 or lower and every subscore less than 2. Partial response was defined as a decrease of Mayo score at least 3 points from baseline.ResultsTwenty-three patients (69.7%) showed clinical remission and 29 patients (87.8%) showed partial response in the observation period. When the remission and non-remission groups were compared in univariate analysis, only a higher total Mayo score at base line (11.0±0.9 vs. 9.9±1.5; P=0.04) was related to remission. The remission maintenance rate decreased with time in the Kaplan-Meier analysis. Two patients experienced re-remission after the first remission followed by aggravation during infliximab treatment. Three patients stopped infliximab treatment owing to adverse events including rhabdomyolysis, pneumonia, and fever of unknown origin.ConclusionsIf there is no choice except surgery for UC patients refractory to conventional treatment, infliximab is an effective and relatively safe treatment option for these patients in Korea
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