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Abstract Background Acanthamoeba spp. are the causative agents of a severe keratitis occurring mainly in contact lens wearers. The genus comprises more than 24 species that are currently divided into 20 different genotypes (T1-T20) according to sequence variations in the 18S rRNA gene. The objective of this study was to identify the genotypes and sub-genotypes of Acanthamoeba isolates collected at the Parasitology Laboratory of the Public Health Institute of Chile, the only laboratory in the country where Acanthamoeba screening is performed. This is the first report of genotypic identification of clinical isolates of Acanthamoeba in Chile and one of the few in South America. Results In this study, 114 Acanthamoeba isolates from 76 Acanthamoeba keratitis patients, obtained between 2005–2016, were genotyped. T4 was the predominant genotype; T2 and T11 genotypes, which are scarcely reported worldwide, were also identified in Chilean patients (one and two patients, respectively). This is the first report of T2 and T11 genotypes isolated from Acanthamoeba keratitis patients in South America. It is also the first report of the T2 genotype circulating in this continent. Analysis of the diagnostic fragment 3 region of the 18S rRNA gene showed 24 T4 variants, with a predominance of the sub-genotype T4/A, followed by T4/B, T4/G, T4/C and T4/D. Bayesian analysis revealed three groups among the T4 variants: two well supported groups that included 12 and 7 sub-genotypes, respectively, and a weakly supported group that included 5 sub-genotypes. Most of the predominant T4 sub-genotypes belonged to the same group, which included 71.3% of the patients, while some minority variants lied mainly in the other two clusters. Conclusions T2, T4 and T11 genotypes were predominantly isolated from the Acanthamoeba keratitis patients in Chile. Chilean predominant T4 sub-genotypes, which have also been reported worldwide, formed a separate cluster of the minority T4 variants. This study provides useful information about the predominant genotypes and subgenotypes that would be useful in selecting suitable strains to develop immunological and/or molecular diagnostic assays in Chile.

Background: Acanthamoeba spp. are the causative agents of a severe keratitis occurring mainly in contact lens wearers. The genus comprises more than 24 species that are currently divided into 20 different genotypes (T1-T20) according to sequence variations in the 18S rRNA gene. The objective of this study was to identify the genotypes and sub-genotypes of Acanthamoeba isolates collected at the Parasitology Laboratory of the Public Health Institute of Chile, the only laboratory in the country where Acanthamoeba screening is performed. This is the first report of genotypic identification of clinical isolates of Acanthamoeba in Chile and one of the few in South America. Results: In this study, 114 Acanthamoeba isolates from 76 Acanthamoeba keratitis patients, obtained between 2005–2016, were genotyped. T4 was the predominant genotype; T2 and T11 genotypes, which are scarcely reported worldwide, were also identified in Chilean patients (one and two patients, respectively). This is the first report of T2 and T11 genotypes isolated from Acanthamoeba keratitis patients in South America. It is also the first report of the T2 genotype circulating in this continent. Analysis of the diagnostic fragment 3 region of the 18S rRNA gene showed 24 T4 variants, with a predominance of the sub-genotype T4/A, followed by T4/B, T4/G, T4/C and T4/D. Bayesian analysis revealed three groups among the T4 variants: two well supported groups that included 12 and 7 sub-genotypes, respectively, and a weakly supported group that included 5 sub-genotypes. Most of the predominant T4 sub-genotypes belonged to the same group, which included 71.3% of the patients, while some minority variants lied mainly in the other two clusters. Conclusions: T2, T4 and T11 genotypes were predominantly isolated from the Acanthamoeba keratitis patients in Chile. Chilean predominant T4 sub-genotypes, which have also been reported worldwide, formed a separate cluster of the minority T4 variants. This study provides useful information about the predominant genotypes and subgenotypes that would be useful in selecting suitable strains to develop immunological and/or molecular diagnostic assays in Chile. [ABSTRACT FROM AUTHOR]

BACKGROUND: DF3/MUC1 mucin is expressed in various cancer tissues, and many in vitro studies have suggested that it may play a role in the aggressive behavior of malignant tumors. However, to the best of the authors' knowledge, the relation between DF3/MUC1 expression and outcome has not yet been investigated in patients with oral squamous cell carcinoma (OSCC). The objective of the current study was to evaluate the prognostic significance of DF3/MUC1 expression in patients with OSCC. METHODS: The expression profile of DF3/MUC1 in OSCC tissues from 206 patients was examined using immunohistochemistry. Its prognostic significance in OSCC was statistically analyzed on the basis of detailed clinicopathologic factors. RESULTS: DF3/MUC1 expression was found to be significantly correlated with tumor aggressiveness, such as pathologic lymph node metastasis ( P = .002), advanced tumor stage ( P = .02), diffuse invasion of cancer cells ( P = .03), and vascular invasion ( P = .01). Respectively, the overall survival (OS)and disease-free survival (DFS) rates were significantly worse for patients with DF3/MUC1 expression compared with those without DF3/MUC1 expression ( P = .001 and P = .0003, respectively). Multivariate analysis demonstrated that DF3/MUC1 expression was an independent prognostic factor for both OS and DFS ( P = .04 for both). In addition, DF3/MUC1 expression was found to be an independent risk factor for subsequent regional lymph node metastasis ( P = .03). CONCLUSIONS: Aberrant expression of DF3/MUC1 is an independent prognostic factor indicating poor prognosis in patients with OSCC. DF3/MUC1 expression is a risk factor for subsequent lymph node metastasis in patients with OSCC and therefore may represent an indication for elective neck dissection. Patients with OSCC demonstrating positive expression of DF3/MUC1 should be followed carefully. Cancer 2012. © 2012 American Cancer Society. [ABSTRACT FROM AUTHOR]

To study the effects of recombinant expression vector containing human breast cancer DF3 promotor and diphtheria toxin A fragment on human breast cancer cells. Constructing recombinant expression vector PGL3-DF3-DTA and transfecting it into human breast cancer cells of DF3 positive and negative. By means of RT-PCR to measure the expression of DTA in human breast cancer cells. MTT color-imetry was used to examine the effect of PGL3-DF3-DTA on growth of human breast cancer cells. By experiment on nude mice to observe the killing effect of PGL3-DF3-DTA on human breast cancer cells. Recombinant expression vector PGL3-DF3-DTA was highly expressed in human breast cancer cell line of DF3 positive, and it could kill the human breast cancer cells not only in vitro but also in vivo. Recombinant expression vector PGL3-DF3-DTA could produce specific killing effect on human breast cancer cell line of DF3 positive. [ABSTRACT FROM AUTHOR]

Introduction. Acanthamoeba keratitis is a sight-threatening corneal infection that is commonly reported among contact lens users and those suffering from corneal trauma. The prevalence of Acanthamoeba species or genotypes in causing keratitis infection is not well known. Aim. This study was conducted to identify and genotype Acanthamoeba isolates from keratitis patients, targeting the ribosomal nuclear subunit ( Rns ) region, and describe the associated clinical presentation and treatment outcome. Methodology. Thirty culture-confirmed patients with Acanthamoeba keratitis, identified in a tertiary eye care centre in South India during the period from December 2016 to December 2018, were included in this study. The data collected from patient records include demographic details, history of illness, mode of trauma, treatment history and follow-up status. The genotype and species were identified based on the Rns sequence and phylogenetic tree analysis. Results. Acanthamoeba culbertsoni was the most predominant keratitis-causing species, followed by Acanthamoeba quina, Acanthamoeba castellanii, Acanthamoeba healyi, Acanthamoeba hatchetti, Acanthamoeba polyphaga and Acanthamoeba stevensoni . Three major genotypes were identified (T4, T11 and T12), with the T4 genotype being the most predominant, with four subclusters, i.e. T4A, T4B, T4D and T4E. This is the first report on corneal infection by the A. stevensoni T11 genotype and the A. healyi T12 genotype. No significant correlation was observed between the clinical outcomes of corneal disease and the genotypes or species. Conclusion. Rns genotyping is very effective in identifying the Acanthamoeba species and genotype in keratitis. Genotyping of Acanthamoeba spp. will help to advance our understanding of genotype-specific pathogenesis and geographical distribution.