Publications by authors named "Oswaldo Ortiz"

Background And Aims: The adenoma detection rate (ADR), recognized as a surrogate marker for colorectal cancer (CRC) incidence and mortality reduction, is closely linked to the efficacy of bowel cleansing. However, there is a dearth of evidence examining the impact on ADR when using 2 distinct very-low-dose bowel cleansing products. This study sought to compare ADR in an immunochemical fecal occult blood test (iFOBT)-based organized screening program by using 1 L of polyethylene glycol plus ascorbate (1L-PEGA) versus sodium picosulfate with magnesium citrate (SPMC), both administered in a split-dose regimen.

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Background: Computer-aided detection (CADe) systems for colonoscopy have been shown to increase small polyp detection during colonoscopy in the general population. People with Lynch syndrome represent an ideal target population for CADe-assisted colonoscopy because adenomas, the primary cancer precursor lesions, are characterised by their small size and higher likelihood of showing advanced histology. We aimed to evaluate the performance of CADe-assisted colonoscopy in detecting adenomas in individuals with Lynch syndrome.

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Background And Study Aims: Our aim was to determine the impact of the SARS-CoV-2 pandemic on the diagnosis and prognosis of colorectal cancer (CRC).

Patients And Methods: This prospective cohort study included individuals diagnosed with CRC between March 13, 2019 and June 20, 2021 across 21 Spanish hospitals. Two time periods were compared: prepandemic (from March 13, 2019 to March 13, 2020) and pandemic (from March 14, 2020 to June 20, 2021, lockdown period and 1 year after lockdown).

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Background: Detection and treatment of recurrence after piecemeal endoscopic mucosal resection of nonpedunculated colorectal polyps are crucial for avoidance of post-colonoscopy cancer. Linked-color imaging (LCI) has demonstrated improved polyp detection but has never been assessed for evaluation of post-polypectomy scars. Our aim was to compare sensitivity and negative predictive value (NPV) between LCI and white-light endoscopy (WLE) for detection of post-polypectomy recurrence.

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Article Synopsis
  • * Results showed no significant difference in the overall detection rates of advanced colorectal neoplasia between the CAD-assisted group (34.8%) and the control group (34.6%), indicating CAD might not enhance the detection of these lesions.
  • * However, CAD did lead to an increase in detecting specific types of lesions, such as nonpolypoid lesions and proximal adenomas, suggesting it may still have some benefits in certain scenarios, though the high detection rates in controls could affect the findings' applicability.
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Serrated polyposis syndrome (SPS) is one of the most frequent polyposis syndromes characterized by an increased risk for developing colorectal cancer (CRC). Although SPS etiology has been mainly associated with environmental factors, germline predisposition to SPS could also be relevant for cases with familial aggregation or a family history of SPS/CRC. After whole-exome sequencing of 39 SPS patients from 16 families, we identified a heterozygous germline frameshift variant in the gene (c.

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 Artificial intelligence is currently able to accurately predict the histology of colorectal polyps. However, systems developed to date use complex optical technologies and have not been tested in vivo. The objective of this study was to evaluate the efficacy of a new deep learning-based optical diagnosis system, ATENEA, in a real clinical setting using only high-definition white light endoscopy (WLE) and to compare its performance with endoscopists.

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Serrated polyposis syndrome (SPS) is associated with a high risk for colorectal cancer. Intense promoter hypermethylation is a frequent molecular finding in the serrated pathway and may be present in normal mucosa, predisposing to the formation of serrated lesions. To identify novel biomarkers for SPS, fresh-frozen samples of normal mucosa from 50 patients with SPS and 19 healthy individuals were analyzed by using the 850K BeadChip Technology (Infinium).

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Article Synopsis
  • The study looked at the occurrence of patients with 10 or more colorectal adenomas in a screening program using a fecal immunochemical test (FIT) from 2010 to 2018.
  • Out of nearly 10,000 participants, only 2.2% had 10 or more adenomas, and only a small percentage exhibited inherited syndromes.
  • The findings indicate a low risk of colorectal cancer and advanced neoplasia after the first surveillance colonoscopy, with risk decreasing over time.
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BACKGROUND AND STUDY AIM : Delayed bleeding is a common adverse event following endoscopic mucosal resection (EMR) of large colorectal polyps. Prophylactic clip closure of the mucosal defect after EMR of nonpedunculated polyps larger than 20 mm reduces the incidence of severe delayed bleeding, especially in proximal polyps. This study aimed to evaluate factors associated with complete prophylactic clip closure of the mucosal defect after EMR of large polyps.

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  • The "diagnose-and-leave-in" policy aims to lower risks and costs linked to unnecessary polypectomies in the average-risk population but recommends removing all polyps in individuals with Lynch syndrome due to their higher cancer risk.
  • A study analyzed data from a clinical trial involving 256 Lynch syndrome patients, using advanced visual techniques to assess diminutive rectosigmoid lesions before making decisions about polypectomy.
  • Results indicated that this strategy could safely avoid 59% of unnecessary polypectomies, suggesting it's a feasible approach for managing diminutive polyps in Lynch syndrome patients.
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Background & Aims: Management of delayed (within 30 days) postpolypectomy bleeding (DPPB) has not been standardized. Patients often undergo colonoscopies that do not provide any benefit. We aimed to identify factors associated with therapeutic intervention and active bleeding after DPPB.

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Background And Aims: Recent studies have found an increase in the seroprevalence of hepatitis E virus (HEV) infection in patients with autoimmune hepatitis (AIH). We aimed to assess the prevalence of positive anti-HEV IgM and IgG, and HEV-RNA in a cohort of patients with AIH, to determine the impact of positive HEV serology on patient outcome, and to evaluate the role of hypergammaglobulinemia and positive autoantibodies in the presence of positive anti-HEV serology.

Methods: One hundred and five patients tested for HEV infection between 2014 and 2018 were included in the study: 50 with chronic AIH (more than 1 year on treatment), and 55 with an acute hepatitis (30 patients with acute AIH and 25 with non-AIH).

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Background And Study Aims: Serrated polyposis syndrome (SPS) is a condition with high risk for colorectal cancer. The Endocuff device has been shown to increase adenoma detection in the general and screening population. We aimed to ascertain whether Endocuff-assisted colonoscopy increases detection of serrated lesions in comparison with standard colonoscopy during the surveillance of patients with SPS.

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Study Objectives: By measuring the apnea length, ventilatory phase, respiratory cycle length, and loop gain, we can further characterize the central apneas of high altitude (CAHA).

Methods: Sixty-three drivers of all-terrain vehicles, working in a Peruvian mine located at 2,020 meters above sea level (MASL), were evaluated. A respiratory polygraph was performed in the first night they slept at high altitude.

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Objectives: While the pathophysiology of bipolar disorder (BD) remains to be elucidated, postmortem and neuroimaging studies have suggested that abnormalities in the dorsolateral prefrontal cortex (DLPFC) are implicated. We compared the levels of specific brain chemicals of interest measured with proton magnetic resonance spectroscopy ((1)H MRS) in medication-free BD subjects and age- and gender-matched healthy controls. We hypothesized that BD subjects would present abnormal cellular metabolism within the DLPFC, as reflected by lower N-acetyl-aspartate (NAA) and creatine + phosphocreatine (Cr + PCr).

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