Absolute quantification of gene E7 in cervical samples of women infected by HPV using real time PCR

Objective: High grade oncogenic types of human papillomavirus (HPV), especially HPV16 and HPV18, possess a gene called E7, which acts on genes that regulate cell growth, promoting development of pre-neoplastic lesions that can lead to invasive carcinomas. The absolute quantification of this gene in cervical samples of HPV-infected women may contribute for better understanding the evolution of these lesions induced by the virus. Methods: We collected 60 cervicovaginal smears of women infected by HPV with or without uterine cervical squamous intraepithelial lesion, SIL) and 10 samples of women with no HPV infection or SIL. The absolute quantification of gene E7 was performed by Realtime PCR using specific primers and probes. Results: Samples infected by HPV16 have a higher number of gene E7 copies when compared to samples infected by HPV18. In the HPV18 group it was observed that those obtained from patients with low or high grade squamous intraepithelial lesions (HSIL) or invasive cervical cancer presented significantly higher concentrations of gene E7 when compared to patients with no cervical lesions. The number of gene E7 copies was higher in the group infected by HPV16 than by HPV18. In spite of that, there was no difference in the number of gene E7 copies in samples infected by HPV16 with or without SIL. Conclusions: Among the samples with HPV18, the number of copies of gene E7 was higher in the group with cervical lesions, and no differences were found for SIL, HSIL or invasive cancer patients.

The emergence of the cortisol circadian rhythm in monozygotic and dizygotic twin infants: the twin-pair synchrony.

OBJECTIVE: Studies on the influence of genetic factors on the ontogeny of cortisol circadian rhythm in infants are lacking. This study evaluated the influence of twinning and the heritability on the age of emergence of salivary cortisol rhythm. DESIGN AND SUBJECTS: A longitudinal study was performed using salivary samples obtained during morning and night, at 2, 4, 8, 12, 16, 20 and 24 weeks of postnatal life in 34 infants, 10 monozygotic (MZ) and 7 dizygotic (DZ) twin pairs. Salivary cortisol was determined by radioimmunoassay (RIA). Zigosity was verified by DNA analysis of at least 13 short tandem repeat polymorphisms. Difference of the emergence of cortisol circadian rhythm, within each twin pair, the intraclass correlation coefficient and the heritability index (h(2)) were calculated. RESULTS: The mean (+/- SEM) age of emergence of salivary cortisol circadian rhythm was similar in MZ and DZ (7.8 +/- 1.0 vs 7.4 +/- 1.3 weeks). Seven pairs showed coincidence of the emergence of cortisol rhythm. Ten pairs were not coincident; among them the within-pair difference of emergence of salivary circadian rhythm was similar in both MZ and DZ groups. The intraclass correlation coefficients were rMZ = 0.60, P = 0.02; and rDZ = 0.65, P = 0.03, respectively. The heritability index (h(2)) was 0.21 (ns). CONCLUSIONS: Salivary circadian rhythm appeared at the same postnatal age in MZ and DZ twin infants. Although several physiological aspects might be involved, the heritability index, obtained in the present study, suggests less genetic than environmental impact on the age of the onset of the cortisol circadian rhythm. Our data also indicated that each twin-pair show synchrony because they probably shared prenatal and postnatal environmental synchronizers.

PCR diagnosis of HPV in cervical biopsies of CIN and invasive neoplasia formerly diagnosed as HPV negative.

OBJECTIVE: To evaluate whether the polymerase chain reaction (PCR) enhances the diagnosis of human papillomavirus (HPV) in biopsies of the uterine cervix with cervical intraepithelial neoplasia (CIN) or invasive neoplasia. STUDY DESIGN: Samples of 71 paraffin-embedded cervical tissue blocks from patients seen in the period 1997-1998 were analyzed. Samples were selected according to age (18-60 years old) and an active sexual life and divided in to 3 groups: test (samples with CIN or invasive neoplasia and a negative HPV diagnosis), positive controls (samples with CIN or invasive neoplasia and a positive HPV diagnosis) and negative controls (samples without CIN or invasive neoplasia and a negative HPV diagnosis). Samples were subjected to DNA extraction and PCR for HPV detection. RESULTS: PCR analysis matched the colposcopic and cytopathologic diagnoses in the positive and negative controls. However, 77% of samples in test group were HPV positive. CONCLUSION: CIN, an invasive neoplasm, is associated with the presence of HPV. Colposcopy and cytopathology are efficient but not sufficient to identify HPV. Thus, despite the high cost, PCR can be used as an additional examination, in women with cervical lesions.