A substantial body of evidence has confirmed human papillomavirus (HPV) infection as an etiologic agent in human cervical cancer. To evaluate the association between HPV and cervical cancer in Chinese women, we examined tumor specimens from women who lived in Shanghai, People's Republic of China. Biopsies from 40 women, diagnosed with either squamous-cell carcinoma (n = 35) or adenocarcinoma (n = 5) were tested for HPV DNA by PCR. The HPV types present in tumors were determined either by hybridization of PCR products with HPV type-specific probes or by PCR-based sequencing. A total of 35 of the 40 cervical cancer specimens (87.5%) contained HPV DNA. The following distribution and types were detected: 7.5% HPV 16, 10% HPV 18, 20% HPVs 16 and 18, 15% HPV 52, 15% HPV 58, 12.5% HPVs 52 and 58 and 7.5% unclassified HPVs. In this population of Chinese women with cervical cancer, HPV 52 and 58 were as prevalent as the "high-risk" (for cervical cancer) viruses HPVs 16 and 18.
The tripeptide 1,2-dihydro-(3H)-pyrrolo[3,2-e]indole-7-carboxylate (CDPI3) binds to the minor groove of DNA with high affinity. When this minor groove binder (MGB) is conjugated to the 5'-end of short oligodeoxynucleotides (ODNs), the conjugates form unusually stable hybrids with complementary DNA in which the tethered CDPI3group resides in the minor groove. We show that these conjugates can be used as PCR primers. Due to their unusually high binding affinity, conjugates as short as 8-10mers can be used to amplify DNA with good specificity and efficiency. The reduced length primers described here might be appropriate for the PCR amplification of viral sequences which possess a high degree of variability (e.g., HPV, HIV) or for recent techniques such as gene hunting and differential display which amplify multiple sequences using short primer pairs.
Cyclooxygenase 2 (COX-2) overexpression has been described in sporadic colonic neoplasia, but its role in ulcerative colitis (UC) neoplastic progression remains unexplored. Although the specific role of cyclooxygenase in colonic neoplasia is uncertain, its inhibition by nonsteroidal anti-inflammatory drugs decreases the risk of sporadic colonic adenocarcinoma and causes regression of adenomas in familial adenomatous polyposis. To investigate the role of COX-2 in UC-associated neoplasia, we assessed COX-2 protein and mRNA expression throughout the spectrum of UC-associated neoplastic lesions in four total colectomy specimens, using immunocytochemistry and a novel TaqMan reverse transcriptase-polymerase chain reaction assay. The findings were correlated with DNA ploidy and inflammatory activity. We found COX-2 overexpression throughout the neoplastic spectrum in UC (P < 0.0001, R 2 ,)35.0؍ even in diploid samples that were negative for dysplasia. Overall, neoplastic change explained 53% of the variation in COX-2 expression, whereas inflammatory activity explained only 11%. COX-2 was overexpressed in all aneuploid samples and in 38% of diploid samples (P ؍ 0.0074). cDNA representational difference analysis was also performed and revealed that COX-2 mRNA was an up-regulated cDNA representational difference analysis difference product. COX-2 overexpression occurs early in UC-associated neoplasia, and the increase cannot be explained by inflammatory activity alone. The data suggest that COX-2-specific inhibitors may have a chemopreventative role in UC but the possibility that they could exacerbate UC inflammatory activity needs to be tested. Cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2) are cyclooxygenase enzymes that convert arachidonic acid to inflammatory and other physiological mediators, including prostaglandins, prostacyclin, and thromboxane. 1,2 COX-1 is constitutively expressed in most tissues, including the gastrointestinal tract, at a relatively stable level and is thought to help protect the gastrointestinal tract from injury. 1,2 COX-2 is an inducible cyclooxygenase whose production is stimulated by interleukin-1, tumor necrosis factor, and many other mediators. 1,2 COX-2 is thought to play a role in the reparative process after mucosal injury in the gastrointestinal tract. 1,2 Multiple studies suggest that COX-2 plays a role in sporadic colorectal neoplasia, based on its overexpression in colonic adenomas and carcinomas, as shown by both immunohistochemistry and reverse transcriptasepolymerase chain reaction (RT-PCR). [3][4][5] Cyclooxygenase inhibitors such as nonsteroidal anti-inflammatory drugs (NSAIDs) substantially decrease the risk of colorectal cancer, as well as the number and size of adenomas in familial adenomatous polyposis patients. 6 -8 Experimentally, NSAIDs prevent colonic adenocarcinoma in rodents with an familial adenomatous polyposis phenotype (the APC min mouse model). 9,10 Understanding the role of COX-2 in colonic neoplasia is thus particularly important because of these t...
Primers that contain portions noncomplementary to the target region are usually used to add to the PCR product a utility sequence such as a restriction site or a universal probe binding site. We have demonstrated that primers with short 5'AT-rich overhangs increase real-time PCR fluorescent signal. The improvement is particularly significant for difficult to amplify templates, such as highly variable viral sequences or bisulfite-treated DNA.
Most bacteria express multiple adhesins that contribute to surface attachment and colonization. However, the network and relationships between the various adhesins of a single bacterial species are less well understood. Here, we examined two well-characterized adhesins in Enterococcus faecalis, aggregation substance and endocarditis- and biofilm-associated pili, and found that they exhibit distinct functional contributions depending on the growth stage of the bacterial community. Pili interfere with aggregation substance-mediated clumping and plasmid transfer under planktonic conditions, whereas the two adhesins structurally complement one another during biofilm development. This study advances our understanding of how E. faecalis, a ubiquitous member of the human gut microbiome and an opportunistic pathogen, uses multiple surface structures to evolve and thrive.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.