50 research outputs found

    Timeless Links Replication Termination to Mitotic Kinase Activation

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    The mechanisms that coordinate the termination of DNA replication with progression through mitosis are not completely understood. The human Timeless protein (Tim) associates with S phase replication checkpoint proteins Claspin and Tipin, and plays an important role in maintaining replication fork stability at physical barriers, like centromeres, telomeres and ribosomal DNA repeats, as well as at termination sites. We show here that human Tim can be isolated in a complex with mitotic entry kinases CDK1, Auroras A and B, and Polo-like kinase (Plk1). Plk1 bound Tim directly and colocalized with Tim at a subset of mitotic structures in M phase. Tim depletion caused multiple mitotic defects, including the loss of sister-chromatid cohesion, loss of mitotic spindle architecture, and a failure to exit mitosis. Tim depletion caused a delay in mitotic kinase activity in vivo and in vitro, as well as a reduction in global histone H3 S10 phosphorylation during G2/M phase. Tim was also required for the recruitment of Plk1 to centromeric DNA and formation of catenated DNA structures at human centromere alpha satellite repeats. Taken together, these findings suggest that Tim coordinates mitotic kinase activation with termination of DNA replication

    CTCF Prevents the Epigenetic Drift of EBV Latency Promoter Qp

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    The establishment and maintenance of Epstein-Barr Virus (EBV) latent infection requires distinct viral gene expression programs. These gene expression programs, termed latency types, are determined largely by promoter selection, and controlled through the interplay between cell-type specific transcription factors, chromatin structure, and epigenetic modifications. We used a genome-wide chromatin-immunoprecipitation (ChIP) assay to identify epigenetic modifications that correlate with different latency types. We found that the chromatin insulator protein CTCF binds at several key regulatory nodes in the EBV genome and may compartmentalize epigenetic modifications across the viral genome. Highly enriched CTCF binding sites were identified at the promoter regions upstream of Cp, Wp, EBERs, and Qp. Since Qp is essential for long-term maintenance of viral genomes in type I latency and epithelial cell infections, we focused on the role of CTCF in regulating Qp. Purified CTCF bound ∼40 bp upstream of the EBNA1 binding sites located at +10 bp relative to the transcriptional initiation site at Qp. Mutagenesis of the CTCF binding site in EBV bacmids resulted in a decrease in the recovery of stable hygromycin-resistant episomes in 293 cells. EBV lacking the Qp CTCF site showed a decrease in Qp transcription initiation and a corresponding increase in Cp and Fp promoter utilization at 8 weeks post-transfection. However, by 16 weeks post-transfection, bacmids lacking CTCF sites had no detectable Qp transcription and showed high levels of histone H3 K9 methylation and CpG DNA methylation at the Qp initiation site. These findings provide direct genetic evidence that CTCF functions as a chromatin insulator that prevents the promiscuous transcription of surrounding genes and blocks the epigenetic silencing of an essential promoter, Qp, during EBV latent infection

    Mortality and pulmonary complications in patients undergoing surgery with perioperative sars-cov-2 infection: An international cohort study

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    Background The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (740%) had emergency surgery and 280 (248%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (261%) patients. 30-day mortality was 238% (268 of 1128). Pulmonary complications occurred in 577 (512%) of 1128 patients; 30-day mortality in these patients was 380% (219 of 577), accounting for 817% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 175 [95% CI 128-240], p<00001), age 70 years or older versus younger than 70 years (230 [165-322], p<00001), American Society of Anesthesiologists grades 3-5 versus grades 1-2 (235 [157-353], p<00001), malignant versus benign or obstetric diagnosis (155 [101-239], p=0046), emergency versus elective surgery (167 [106-263], p=0026), and major versus minor surgery (152 [101-231], p=0047). Interpretation Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Impact of pollution on coastal zone monitoring with benthic foraminifera of Tuticorin, south east coast of India

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    376-378Magnitude of corrosive effect, lower than normal ornamentation sutural thickenings, pores enlargement and widening of apertures in foraminifera were taken as indices of pollution impact on the coastal zone of Tuticorin. Pollution causes reduced diversity with a decrease in foraminiferal population. More over, there is a reduction in size followed by test wall thickening in Ammonia and Florilus and dispersal and dilution of the pollutants resulting faunal abundances. The effluents effect presents morphological anomalies like erosion along peripheries, abnormal growth of the end chambers inferred dissolution and consequent destruction of small thin walled biota

    Mycosynthesis of silver nanoparticles and their characterization

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    Mycosynthesis deal with an energy-saving and eco-friendly process intended for extracellular synthesis of AgNPs, by means of cell-free filtrates of fungi Aspergillus niger and Fusarium semitectum as reducing agents. Optimization of different parameters during biosynthetic process demonstrated diverse property on production rate, the size, distribution, yield of biosynthesized AgNPs. SEM micrographs showed polydisperse spherical and ellipsoid nanoparticles (SIZE). AgNPs exhibits potential antimicrobial effect than Ag+ not in favor of E. coli, Staphylococcus aureus, and Pseudomonas aeruginosa. These results demonstrate that mycosynthesis of AGNPs is a cost effective and eco-friendly method, resulting in particles with antibacterial properties that are efficient as an antimicrobial agent. • Characterization of Silver nano particle is widely applauded domain at present. • Mycosynthesis of AgNPs as reducing agents and exhibits potential antimicrobial effect. • Results of mycosynthesis of AgNPs is cost effective and ecofriendly. Keywords: AgNPs, Extracellular biosynthesis, Aspergillus niger, Fusarium semitectum, Antimicrobial effec

    Analysis of Boil-Off loss in the cocoon shells of theSilkworm (Bombyx Mori L.) bivoltine breeds and their hybrids.

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    The silkworm, Bombyx moriL has been reared since dawn of human civilization because of commercial use of silk in textile industry. The silk fiber is made up of two distinguished proteins namely: fibroin and sericin. The removal of sericin is known as boil off loss ratio (B.O.R). It is considered as one of the important qualitative trait during the course of silk worm breeding. An attempt has been made in the current investigation to record the cocoon parameters and boil off loss ratio in parental bivoltine breeds viz., CSR2, CSR4,CSR6, CSR16, CSR17, CSR26 and CSR27. and direct cross hybrids viz., CSR2 x CSR4, CSR16 x CSR17, CSR2 x CSR27, CSR6 x CSR26 and FC1x FC2 [(CSR6 x CSR26) x (CSR2 x CSR27)] and reciprocal crosses hybrids viz., CSR4 x CSR2, CSR17 x CSR16, CSR27 x CSR 2, CSR26x CSR6 and FC2 x FC1 [( CSR2 x CSR27) x (CSR6 x CSR26)]. The result of the study inferred that, the hybrids of direct cross performed well in respect of cocoon weight, shell weight, shell percentage, filament length and denier. The hybrids of direct crosses recorded lowest boil-off loss ratio compared to reciprocal crosses. The hybrids of direct crosses such as CSR2 x CSR4 and CSR16 x CSR17 expressed better heterosis over mid parental value for boil-off loss ratio. Similarly, the hybrid of reciprocal crosses CSR26 x CSR6 expressed heterosis over mid parental value

    Tidal fluctuations in relation to certain physic-chemical parameters in Swarnamukhi river estuary, east coast of India

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    232-234Diurnal variations in environmental features covering over 3 days were recorded. Wind velocity and salinity followed the tidal fluctuations. A slight inverse relationship was observed between water temperature and dissolved oxygen. Variations in the environmental features during the day and night with tides were not so marked. However, these features showed significant variations during the two low tides. The low tides of the day hours showed higher-dissolved oxygen content and relative higher temperatures when compared with low tides of night

    Anthropogenic Impact on the Pulicat Lagoon Monitoring with Foraminifera, East coast of India

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    Abstract Coastal lagoons are well investigated areas because of their economical and ecological importance. Pulicat Lagoon system which is a store house of all resources is under great threat following the anthropogenic pollution. This complex lagoon ecosystem's surface area is about 500 sq.kms. In spite of the System's conservation statutes its structure has been degenerating rapidly because of pressures fishing, tourism and agricultural activities. Fishing production of Pulicat Lagoon System is approximately 52 tons/ha/year. Although a serious fishery pressure has been determined in the area, according to mortality rate and age compositions, it has been found that the growth of marine life in the environment is in unhealthy condition. The date show that land based and atmospheric sources account about two-thirds of the total impact of contaminants in to the marine lagoon constituting 44 % and 33 % respectively. A total of 30 sediment samples were collected with in the depth zone of 5 fathoms from the lagoon. The study yielded 50 benthic foraminiferal species belongs to 24 genera, 16familys, 8 super families and 3 sub-orders. Variations are also reflected on the foraminiferal test morphology, diversity and distribution. A high percentage of foraminifers almost exclusively Ammonia have damaged shells with a few channels to entire whorl missing. The phenomenon is stress response to the anthropogenic pollution. The Ammonia-Elphidium assemblage is dominant in all stations followed by Spiroloculina -Bolivina assemblage.Suggestions for development of the lagoon management and maximum sustainable marine life production have been offered by determining the present lagoon management and some a biotic characteristics of this ecosystem. Many studies assume or conclude that foraminiferal assemblages and the frequency of deformed tests are proxy indicators of pollution, but others present confounding results. Under studying the complexity of anthropogenic pollution, coastal waters and sediment is critical to the design and interpretation of meaningful studies. Keywords Lake, Foraminifera, Ecology, Anthropogenic Pollution, Ecological Parameters 1.Introduction The study area, is located in the Survey of India toposheets nos: 66 B/2, 66 B/3, 66 C/2 respectively at the scale of 1: 50,000. The study area lies between longitudes 80o 02' -80o 20' E and latitudes 13o22'-13o 45'
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