RESUMO
We aimed to assess the distribution of human papillomavirus (HPV) genotypes in high-grade cervical lesions in Taiwan. The study included 1,086 paraffin-embedded, formaldehyde-fixed cervical intraepithelial neoplasia (CIN) 2/3 specimens. HPV genotyping was performed using polymerase chain reaction (PCR)-based methods. Multiple HPV types were validated by E6 type-specific PCR, direct sequencing and/or real-time PCR. HPV DNA was detected in 995 (91.6%) specimens, and multiple HPV types were identified in 192 (19.3%) samples. The leading HPV types were HPV16 (24%), HPV52 (20%), HPV58 (20%), HPV33 (13%), HPV31 (8%) and HPV18 (4.6%). Although the leading six types consisted of 87.6%, HPV16 or 18 comprised only 30.9%. The prevalence of different HPV types showed a significant association with age. In women older than 50 yr, HPV16 and 18 comprised 21.3% (83/389), while HPV52, 58 and 33 represented 55.5% (216/389). In women aged less than 50 yr, HPV16 and 18 comprised 32.1% (224/697, p < 0.0001), while HPV 52, 58 and 33 represented 47.9% (334/697, p = 0.02). The distribution of HPV genotypes was compared with previously reported findings for Taiwanese women with cervical cancer (CC). The overall HPV16 positivity rate was significantly higher in CC than in CIN 2/3 (odds ratio: 2.14, 95% CI: 1.91-2.40). In addition, HPV18, 39 and 45 were significantly overrepresented in CC, whereas HPV52, 58, 33, 31, 35, 51 and 53 were underrepresented. We concluded that an effective vaccine against the most common HPV types could prevent a significant proportion of cervical cancer cases that occur in Taiwan.
Assuntos
Papillomaviridae/genética , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/genética , Adulto , Envelhecimento , Alphapapillomavirus/classificação , Alphapapillomavirus/genética , Alphapapillomavirus/isolamento & purificação , Primers do DNA , DNA Viral/genética , DNA Viral/isolamento & purificação , Feminino , Amplificação de Genes , Genótipo , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Reação em Cadeia da Polimerase , Taiwan , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/genética , Displasia do Colo do Útero/patologiaRESUMO
MOTIVATION: Maximum-likelihood methods for solving the consensus sequence identification (CSI) problem on DNA sequences may only find a local optimum rather than the global optimum. Additionally, such methods do not allow logical constraints to be imposed on their models. This study develops a linear programming technique to solve CSI problems by finding an optimum consensus sequence. This method is computationally more efficient and is guaranteed to reach the global optimum. The developed method can also be extended to treat more complicated CSI problems with ambiguous conserved patterns. RESULTS: A CSI problem is first formulated as a non-linear mixed 0-1 optimization program, which is then converted into a linear mixed 0-1 program. The proposed method provides the following advantages over maximum-likelihood methods: (1) It is guaranteed to find the global optimum. (2) It can embed various logical constraints into the corresponding model. (3) It is applicable to problems with many long sequences. (4) It can find the second and the third best solutions. An extension of the proposed linear mixed 0-1 program is also designed to solve CSI problems with an unknown spacer length between conserved regions. Two examples of searching for CRP-binding sites and for FNR-binding sites in the Escherichia coli genome are used to illustrate and test the proposed method. AVAILABILITY: A software package, Global Site Seer for the Microsoft Windows operating system is available by http://www.iim.nctu.edu.tw/~cjfu/gss.htm
