DNA Damage-Induced RNAPII Degradation and Its Consequences in Gene Expression.

RPB1, the major and catalytic subunit of human RNA Polymerase II (RNAPII), is specifically degraded by the ubiquitin-proteasome system upon induction of DNA damage by different agents, such as ultraviolet (UV) light. The "last resort" model of RNAPII degradation states that a persistently stalled RNAPII is degraded at the site of the DNA lesion in order to facilitate access to Nucleotide Excision Repair (NER) factors, thereby promoting repair in template strands of active genes. Recent identification and mutation of the lysine residue involved in RPB1 ubiquitylation and degradation unveiled the relevance of RNAPII levels in the control of gene expression.

Estimation of crowding factors for public transport during the COVID-19 pandemic in Santiago, Chile.

A sharp decrease in public transport demand has been observed during the COVID-19 pandemic around the world. In this context, it is relevant to understand how mode preferences have changed since the surge of COVID-19. In order to better understand how the pandemic changed mode choice, particularly regarding the impact of crowding and face mask use in public transport, we conducted a stated preference on-line and on-street survey in Santiago, Chile.

Relationship between the coronary artery calcium quantification and gut microbiota composition in subjects without previous cardiovascular disease: A pilot study.

Aim: To investigate the relationship between gut microbiota composition and the presence of coronary atherosclerosis assessed by coronary artery calcium (CAC) quantification in individuals without previous cardiovascular disease (CVD).

Methods: We included 20 patients over 18 years of age with no history of CVD who underwent multiple detector-computed tomography. From each patient, a stool sample was obtained to characterize gut microbiota composition by sequencing bacterial 16S ribosomal RNA gene.

Characteristics of Serrated Adenomas in Non-Hispanic Whites and African Americans Undergoing Screening Colonoscopy.

Background and aim Adenomatous polyps are precursor lesions for colorectal cancer (CRC). Serrated adenomas/polyps are considered a risk factor for the development of proximal and interval CRC. African-Americans are at higher risk for right-sided CRC.

A DNA intercalating dye-based RT-qPCR alternative to diagnose SARS-CoV-2.

Early detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proven crucial during the efforts to mitigate the effects of the COVID-19 pandemic. Several diagnostic methods have emerged in the past few months, each with different shortcomings and limitations. The current gold standard, RT-qPCR using fluorescent probes, relies on demanding equipment requirements plus the high costs of the probes and specific reaction mixes.

Reciprocal regulation between alternative splicing and the DNA damage response.

Splicing, the process that catalyzes intron removal and flanking exon ligation, can occur in different ways (alternative splicing) in immature RNAs transcribed from a single gene. In order to adapt to a particular context, cells modulate not only the quantity but also the quality (alternative isoforms) of their transcriptome. Since 95% of the human coding genome is subjected to alternative splicing regulation, it is expected that many cellular pathways are modulated by alternative splicing, as is the case for the DNA damage response.

Protective Propensity of Race or Environmental Features in the Development of Barrett's Esophagus in African Americans - A Single Center Pilot Study.

Background And Study Aims: Barrett's Esophagus (BE) is a well-recognized pre-malignant condition. Previous data indicate histologically confirmed BE frequency varies by ethnicity in the United States. However, clinical factor assessment to explain this has only occurred in a veteran population to date.

Coupling between nucleotide excision repair and gene expression.

Gene expression and DNA repair are fundamental processes for life. During the last decade, accumulating experimental evidence point towards different modes of coupling between these processes. Here we discuss the molecular mechanisms by which RNAPII-dependent transcription affects repair by the Nucleotide Excision Repair system (NER) and how NER activity, through the generation of single stranded DNA intermediates and activation of the DNA damage response kinase ATR, drives gene expression in a genotoxic scenario.

Relation between serum levels of chemotaxis-related factors and the presence of coronary artery calcification as expression of subclinical atherosclerosis.

Background: Atherosclerotic plaque formation is characterized by recruitment of monocytes/macrophages, which contributes to its calcification by releasing pro-osteogenic cytokines. Chemotaxis-related proteins, including netrin-1, gremlin-1 and macrophage inflammatory protein-1β (MIP-1β), regulate immune cell migration. However, their relation with the presence of subclinical atherosclerosis, assessed by measures of coronary artery calcifications (CAC) in patients without known coronary artery disease (CAD), remains unclear.

Stent type used does not impact complication rate or placement time but can decrease treatment cost for benign and malignant esophageal lesions.

Aim: To evaluate if differences exist between self-expanding esophageal metal stents (SEMS) and self-expanding esophageal plastic stents (SEPS) when used for benign or malignant esophageal disorders with regard to safety, efficacy, clinical outcomes, placement ease and cost.

Methods: A retrospective analysis was performed to evaluate outcome in patients having SEPS/SEMS placed for malignant or benign esophageal conditions from January 2005 to April 2012. Inclusion criteria was completed SEMS/SEPS placement.

Choice of sedation and its impact on adenoma detection rate in screening colonoscopies.

Background: Studies have demonstrated that the use of sedation (regardless of type) increases polyp detection rates during colonoscopy. Compared to conscious sedation (CS), propofol sedation (PS) has led to detection of more advanced polyps, yet no apparent difference was found in the overall adenoma detection rate (ADR) in patients undergoing colonoscopy for various reasons. We aimed to assess whether there was a significant difference in the ADR in patients specifically undergoing screening colonoscopies using PS versus CS.

Gastrointestinal Kaposi's sarcoma: Case report and review of the literature.

Kaposi's sarcoma (KS) of the gastrointestinal tract is not an uncommon disease among individuals with acquired immunodeficiency syndrome (AIDS). The majority is asymptomatic, and for this reason, gastrointestinal KS (GI-KS) remains undiagnosed. With continued tumor growth, considerable variation in clinical presentation occurs including abdominal pain, nausea, vomiting, iron deficiency anemia (either chronic or frank gastrointestinal bleeding), and rarely mechanical obstruction alone or combined with bowel perforation.

African American ethnicity is not associated with development of Barrett's oesophagus after erosive oesophagitis.

Background: Barrett's oesophagus is the primary risk factor for oesophageal adenocarcinoma; erosive oesophagitis is considered an intermediate step with Barrett's oesophagus development potential upon healing. Barrett's oesophagus occurs in 9-19% following erosive oesophagitis but minimal data exists in African Americans. The study aim was to determine if ethnicity is associated with Barrett's oesophagus formation following erosive oesophagitis.

Proton radiotherapy dose perturbations caused by esophageal stents of varying material composition are negligible in an experimental model.

Background: Self-expanding metal and plastic esophageal stents (SEMS and SEPS, respectively) are used in conjunction with chemoradiation for palliation of malignant dysphagia. To date, the dosimetric effects of stents undergoing proton radiotherapy are not known.

Study Aim: To investigate the proton radiotherapy dose perturbations caused by esophageal stents of varying designs and materials undergoing external beam treatment for esophageal cancer.

Neuroendocrine tumors of the gastrointestinal tract: Case reports and literature review.

Neuroendocrine tumors (NET) previously called carcinoid tumors are neoplasms of enterochromaffin/neuroendocrine cell origin which display neurosecretory capacity that may result in the carcinoid syndrome. The annual incidence of patients with NET is 8.4 per 100000; yet many NET remain asymptomatic and clinically undetected.

Ultrasound marking by gastroenterologists prior to percutaneous liver biopsy removes the need for a separate radiological evaluation.

Background/aim: Ultrasound marking by radiologists prior to percutaneous liver biopsy (PLB) results in biopsy site adjustment, decreased pain related complications and improved tissue yield. Minimal data exists on the impact of ultrasound marking by gastroenterologists on these parameters. The study aim was to evaluate whether ultrasound marking by gastroenterologists results in improved PLB tissue yield, fewer needle passes and decreased biopsy failure rates compared to blind biopsy, eliminating the need for a separate radiological evaluation.

[Outbreak of human A (H1N1) influenza in turkeys of a commercial poultry farm, Valparaiso, Chile: August 2009].

The Chilean Ministry of Health (MINSAL) led an investigation to identify associated factors to human influenza A (H1N1) infection in turkeys from poultry farms, Valparaíso. The Agriculture and Livestock Farming Service (SAG) informed the detection of influenza A (low pathogenicity) in turkeys and the Public Health Institute (ISP) confirmed influenza A (H1N1).The study included 100% of operative wards: 31% presented positive event (influenza A (H1N1)); 60% if considered only reproductive wards.

Rubella outbreaks following virus importations: the experience of Chile.

Background: Strategies for accelerated control of rubella and congenital rubella syndrome (CRS) in Chile included mass vaccination of women of childbearing age in 1999 but did not include vaccination of adult men.

Methods: We reviewed data from Chile's integrated surveillance system for measles, rubella, and CRS from 2004 through 2009 and describe the epidemiology of rubella outbreaks and implementation of control measures in 2005 and 2007 following mass vaccination of women. Population estimates from census data were used to calculate rubella incidence rates.