Increased Prevalence of Advanced Histologic Features in Small and Diminutive Polyps in Patients Undergoing Surveillance and Diagnostic Colonoscopy.

OBJECTIVE: Studies addressing small and diminutive polyps and their potential of harboring advanced histologic features (AH) are scarce in Hispanics. We aimed to determine the prevalence of AH in a cohort of Hispanics. METHODS: A retrospective review of medical records of patients who had a colonoscopy from 2005 through 2010. The data collected included demographics, indications, history (personal/family) of colon cancer and/or polyps, and polyp histology. Polyps with high-grade dysplasia, prominent villous component, adenocarcinoma or serrated were classified as having AH. RESULTS: The population comprised 1884 patients, and 3835 polyps were evaluated; 63.3% were diminutive (1-5 mm), 22.7% small (6-9 mm), and 13.9% large (≥10 mm). The prevalence of AH for small and diminutive polyps were 4.9% and 1.1%, respectively. Of the polyps with AH, 11.9% were diminutive and 19.6% small. Small polyps were 5.04 times more likely to harbor AH than were diminutive polyps. Distal rather than proximal polyps were more likely to harbor AH. Furthermore, AH was >7 times more common in small (6-9 mm) polyps identified during diagnostic or surveillance colonoscopies compared to screening colonoscopies. CONCLUSION: The prevalence of AH was significantly associated with size, location (distal), and procedure indication. Although diminutive polyps (<6 mm) were less likely to harbor AH, the risk for non-Hispanics was higher than previously reported. The "resect and discard" strategy for polyps ≤ 1 cm should be used with caution in ethnically diverse cohorts, as the risk for AH may be higher in Hispanics than in non-Hispanic Whites.

Genome Sequences of 408 SARS-CoV-2 Strains Obtained from Nasopharyngeal Swabs in La Araucanía Region, Southern Chile.

Here, we announce the genome sequences of 408 strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) obtained from nasopharyngeal swabs in the Araucanía Region, Southern Chile. The genomes obtained are valuable to expand the availability of useful genomic data for future epidemiological studies of SARS-CoV-2 in Chile and worldwide.

Hyper-phosphorylation of Rb S249 together with CDK5R2/p39 overexpression are associated with impaired cell adhesion and epithelial-to-mesenchymal transition: Implications as a potential lung cancer grading and staging biomarker.

Prediction of lung cancer metastasis relies on post-resection assessment of tumor histology, which is a severe limitation since only a minority of lung cancer patients are diagnosed with resectable disease. Therefore, characterization of metastasis-predicting biomarkers in pre-resection small biopsy specimens is urgently needed. Here we report a biomarker consisting of the phosphorylation of the retinoblastoma protein (Rb) on serine 249 combined with elevated p39 expression. This biomarker correlates with epithelial-to-mesenchymal transition traits in non-small cell lung carcinoma (NSCLC) cells. Immunohistochemistry staining of NSCLC tumor microarrays showed that strong phospho-Rb S249 staining positively correlated with tumor grade specifically in the squamous cell carcinoma (SCC) subtype. Strong immunoreactivity for p39 positively correlated with tumor stage, lymph node invasion, and distant metastases, also in SCC. Linear regression analyses showed that the combined scoring for phospho-Rb S249, p39 and E-cadherin in SCC is even more accurate at predicting tumor staging, relative to each score individually. We propose that combined immunohistochemistry staining of NSCLC samples for Rb phosphorylation on S249, p39, and E-cadherin protein expression could aid in the assessment of tumor staging and metastatic potential when tested in small primary tumor biopsies. The intense staining for phospho-Rb S249 that we observed in high grade SCC could also aid in the precise sub-classification of poorly differentiated SCCs.

Utility of the tourniquet test and the white blood cell count to differentiate dengue among acute febrile illnesses in the emergency room.

Dengue often presents with non-specific clinical signs, and given the current paucity of accurate, rapid diagnostic laboratory tests, identifying easily obtainable bedside markers of dengue remains a priority. Previous studies in febrile Asian children have suggested that the combination of a positive tourniquet test (TT) and leucopenia can distinguish dengue from other febrile illnesses, but little data exists on the usefulness of these tests in adults or in the Americas. We evaluated the diagnostic accuracy of the TT and leucopenia (white blood cell count <5000/mm(3)) in identifying dengue as part of an acute febrile illness (AFI) surveillance study conducted in the Emergency Department of Saint Luke's Hospital in Ponce, Puerto Rico. From September to December 2009, 284 patients presenting to the ED with fever for 2-7 days and no identified source were enrolled. Participants were tested for influenza, dengue, leptospirosis and enteroviruses. Thirty-three (12%) patients were confirmed as having dengue; 2 had dengue co-infection with influenza and leptospirosis, respectively. An infectious etiology was determined for 141 others (136 influenza, 3 enterovirus, 2 urinary tract infections), and 110 patients had no infectious etiology identified. Fifty-two percent of laboratory-positive dengue cases had a positive TT versus 18% of patients without dengue (P<0.001), 87% of dengue cases compared to 28% of non-dengue cases had leucopenia (P<0.001). The presence of either a positive TT or leucopenia correctly identified 94% of dengue patients. The specificity and positive predictive values of these tests was significantly higher in the subset of patients without pandemic influenza A H1N1, suggesting improved discriminatory performance of these tests in the absence of concurrent dengue and influenza outbreaks. However, even during simultaneous AFI outbreaks, the absence of leucopenia combined with a negative tourniquet test may be useful to rule out dengue.