1,114 research outputs found
New pandemics: HIV and AIDS, HCV and chronic hepatitis, Influenza virus and flu
New pandemics are a serious threat to the health of the entire world. They are essentially of viral origin and spread at large speed. A meeting on this topic was held in Lyon, France, within the XIXth Jacques Cartier Symposia, a series of France-Québec meetings held every year. New findings on HIV and AIDS, on HCV and chronic hepatitis, and an update on influenza virus and flu were covered during this meeting on December 4 and 5, 2006. Aspects of viral structure, virus-host interactions, antiviral defenses, drugs and vaccinations, and epidemiological aspects were discussed for HIV and HCV. Old and recent data on the flu epidemics ended this meeting.The
meeting sponsors were the Centre Jacques Cartier, the Agence Nationale
de Recherches sur le SIDA et les hépatites (ANRS) France, the Ecole Normale
Supérieure en Sciences de Lyon, The Réseau SIDA et Maladies Infectieuses
from the Fond de la Recherche en Santé du Québec (FRSQ), The
Institut de Recherches Cliniques de Montréal (IRCM), Boehringer Ingelheim,
Sanofi Aventis, ViroChem Pharma and Merck Frosst. The authors
thank the speakers for their meeting abstracts and comments that helped
writing this review
HIV-1 Subtype and Reverse Transcriptase Genotype: Role for Geographical Location and Founder Effects
Effects of alterations of primer-binding site sequences on human immunodeficiency virus type 1 replication
The human immunodeficiency virus type 1 genomic RNA primer-binding site (PBS) sequence comprises 18 nucleotides which are complementary to those at the 3\u27 end of the replication initiation primer tRNA(3Lys). To investigate the role of the PBS in viral replication, we either deleted the original wild-type PBS (complementary to tRNA(3Lys) or replaced it with DNA sequences complementary to either tRNA(1,2Lys) or tRNA(Phe). Transfection of COS cells with such molecular constructs yielded similar levels of viral progeny that were indistinguishable with regard to viral proteins and tRNA content. Virus particles derived from PBS-deleted molecular clones were noninfectious for MT-4, Jurkat, and CEM-T4 cells. However, infectious viruses were derived from constructs in which the PBS had been altered to sequences complementary to either tRNA(1,2Lys) or tRNA(Phe), although mutated forms showed significant lags in replication efficiency in comparison with wild types. Molecular analysis of reverse-transcribed DNA in cells infected by the mutated viruses indicated that both tRNA(1,2Lys) and tRNA(Phe) could function as primers for reverse transcription during the early stages of infection. Sequencing of full-length proviral DNA, obtained 6 days after infection, revealed the mutated PBS, indicating that a complete cycle of reverse transcription had occurred. During subsequent rounds of infection, reversion of the mutated PBS to wild-type sequences was observed, accompanied by increased production of viral gene products. Reversion to wild-type PBS sequences was confirmed both by specific PCR analysis, using distinct primer pairs, and by direct sequencing of amplified segments. We also performed endogenous in vitro reverse transcription experiments in which synthesis of minus-strand strong-stop viral DNA was primed from a synthetic RNA template containing a PBS complementary to various tRNA isoacceptors. These results showed that tRNA(3Lys) was a much more efficient primer of such reactions than either tRNA(1,2Lys) or tRNA(Phe).<br /
Burnout syndrome and coping strategies in Portuguese oncology health care providers
Background Burnout is a multidimensional syndrome and includes symptoms of emotional exhaustion, depersonalization, and reduced personal accomplishment at work. Oncology health care providers are at high risk to develop symptoms of burnout because of work-related stressors. Adaptive coping strategies adopted to deal with stressors may prevent the development of burnout. Objective The present study aims to assess the association between burnout, functional coping strategies, and occupational factors in a sample of oncology providers, mostly nurses. Methods Sociodemographic Questionnaire, the Maslach Burnout Inventory, and the Problem Solving Inventory âInventĂĄrio de Resolução de Problemasâ were administered. Descriptive, correlational, and linear regression analyses were performed. Results The study showed that emotional exhaustion correlated with lower levels of adaptive coping, less years of experience in Oncology, and a greater amount of hours worked per week. Personal accomplishment was associated with the adaptive coping strategies. No further statistically significant associations were identified. Discussion Our findings support the importance of adaptive coping strategies in order to prevent symptoms of burnout when health professionals face potentially stressful occupational factors. Training aimed at improving adaptive coping skills may prevent burnout syndrome for health care professionals working in Oncology
To Transformers and Beyond: Large Language Models for the Genome
In the rapidly evolving landscape of genomics, deep learning has emerged as a
useful tool for tackling complex computational challenges. This review focuses
on the transformative role of Large Language Models (LLMs), which are mostly
based on the transformer architecture, in genomics. Building on the foundation
of traditional convolutional neural networks and recurrent neural networks, we
explore both the strengths and limitations of transformers and other LLMs for
genomics. Additionally, we contemplate the future of genomic modeling beyond
the transformer architecture based on current trends in research. The paper
aims to serve as a guide for computational biologists and computer scientists
interested in LLMs for genomic data. We hope the paper can also serve as an
educational introduction and discussion for biologists to a fundamental shift
in how we will be analyzing genomic data in the future
Pembrolizumab alone or in combination with chemotherapy as first-line therapy for patients with advanced gastric or gastroesophageal junction adenocarcinoma: results from the phase II nonrandomized KEYNOTE-059 study
BACKGROUND:
The multicohort, phase II, nonrandomized KEYNOTE-059 study evaluated pembrolizumabâ±âchemotherapy in advanced gastric/gastroesophageal junction cancer. Results from cohorts 2 and 3, evaluating first-line therapy, are presented.
METHODS:
Patients â„â18 years old had previously untreated recurrent or metastatic gastric/gastroesophageal junction adenocarcinoma. Cohort 3 (monotherapy) had programmed death receptor 1 combined positive score â„â1. Cohort 2 (combination therapy) received pembrolizumab 200 mg on day 1, cisplatin 80 mg/m2 on day 1 (up to 6 cycles), and 5-fluorouracil 800 mg/m2 on days 1-5 of each 3-week cycle (or capecitabine 1000 mg/m2 twice daily in Japan). Primary end points were safety (combination therapy) and objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 by central review, and safety (monotherapy).
RESULTS:
In the combination therapy and monotherapy cohorts, 25 and 31 patients were enrolled; median follow-up was 13.8 months (range 1.8-24.1) and 17.5 months (range 1.7-20.7), respectively. In the combination therapy cohort, grade 3/4 treatment-related adverse events occurred in 19 patients (76.0%); none were fatal. In the monotherapy cohort, grade 3-5 treatment-related adverse events occurred in seven patients (22.6%); one death was attributed to a treatment-related adverse event (pneumonitis). The objective response rate was 60.0% [95% confidence interval (CI), 38.7-78.9] (combination therapy) and 25.8% (95% CI 11.9-44.6) (monotherapy).
CONCLUSIONS:
Pembrolizumab demonstrated antitumor activity and was well tolerated as monotherapy and in combination with chemotherapy in patients with previously untreated advanced gastric/gastroesophageal junction adenocarcinoma
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Mitigation of off-target toxicity in CRISPR-Cas9 screens for essential non-coding elements.
Pooled CRISPR-Cas9 screens are a powerful method for functionally characterizing regulatory elements in the non-coding genome, but off-target effects in these experiments have not been systematically evaluated. Here, we investigate Cas9, dCas9, and CRISPRi/a off-target activity in screens for essential regulatory elements. The sgRNAs with the largest effects in genome-scale screens for essential CTCF loop anchors in K562 cells were not single guide RNAs (sgRNAs) that disrupted gene expression near the on-target CTCF anchor. Rather, these sgRNAs had high off-target activity that, while only weakly correlated with absolute off-target site number, could be predicted by the recently developed GuideScan specificity score. Screens conducted in parallel with CRISPRi/a, which do not induce double-stranded DNA breaks, revealed that a distinct set of off-targets also cause strong confounding fitness effects with these epigenome-editing tools. Promisingly, filtering of CRISPRi libraries using GuideScan specificity scores removed these confounded sgRNAs and enabled identification of essential regulatory elements
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