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Biomedical subjects

J Si

Publications and source records attributed to J Si.

45 records · Page 3Linked to original sources
PubMed1995

[Detection of p53 mutation using PCR-SSCP silver staining method].

A simple and sensitive technique to detect point mutation of the p53 gene using silver staining method for single-strand conformation polymorphism analysis of polymerase chain reaction (PCR-SSCP) is reported. In this study, the aberrations of the p53 gene (exon 6-8) in clinical specimens of primary cervical carcinoma were examined. Of 27 tumor tissues 2 samples showed mutations of p53 exon 7. Absence of abnormal bands in the p53 exon 6-8 in all ten normal cervical tissues. It appears that inactivation of p53 gene by point mutation is infrequent in clinical samples of human cervical carcinomas.

Base Sequence↗
PubMed1995

[The reversing effect of HPV-16 E6E7 gene antisense plasmid on the HPV-16 positive human cervical carcinoma cells].

Antisense reconstruct, p16as E6E7Neo, harboring HPV-16E6E7 gene of which the expression is regulatable by dexamethasone was constructed. Calcium phosphate mediated transfection was employed to transduce this antisense reconstruct into HPV-16 positive CasKi cell line and HPV negative C-33A cell line (both derived from human cervical carcinoma) respectively. After dexamethasone was added into the culture medium to induce the expression of E6E7 antisense gene, the malignity of CasKi cells were reversed, while the growth characteristics and malignity of C-33A cells were unchanged. The results show that the reversing effect on CasKi cell is specific and mediated by inhibition of expression of E6E7 gene. It also demonstrated a more profound pathogenic role of HPV-16 E6E7 gene in the tumorogenesis of cervical carcinoma and provides a possibility for gene therapy of this tumor.

Animals↗
PubMed1995

[Human papillomavirus, human cytomegalovirus and p53 gene in cervical carcinoma].

OBJECTIVE: To investigate the role of human papillomavirus (HPV) human cytomegalovirus (HCMV) infections and p53 gene mutations in the oncogenesis of cervical cancer and to clarify the association between p53 inactivation and the presence of HPV DNA. METHODS: We examined 38 primary cervical carcinomas and 21 normal cervical specimens for the presence of HPV and HCMV DNA sequences by multiple primers PCR and nest primers PCR. The structure of p53 gene (exons 6-8) was also analyzed by PCR-SSCP silver staining method. RESULTS: Mutations of p53 gene (exon 7) were detected in 2 of 38 tumors. One of the cases with p53 mutation was positive for HPV 16 and two positive for HCMV. HPV 16 and 18 infections were noted in 63.2% (24/38) of the tumors, the positive rate of HCMV was 84.2% (32/38). However, HPV 16,18 and HCMV infection occurred in 4.8% and 38.1% respectively in 21 normal cervical specimens. 21 of the 24 HPV 16,18 positive tumors were also HCMV positive, but none of the normal cervical tissues was infected with both HPV and HCMV. CONCLUSION: Detection of p53 mutations in cervical carcinoma is infrequent and apparently independent of HPV infection. Cervical carcinoma is strongly associated with HPV 16 and 18 infection. A synergistic interaction may occur between HPV and HCMV infections in the oncogenesis of cervical cancer.

Carcinoma, Squamous Cell↗
PubMed1994

Prevalence of human papillomavirus DNA sequences in an area with very high incidence of cervical carcinoma.

To improve our understanding of the relationship and possible associations between human papillomavirus (HPV) infection and the development of cervical malignancies, the presence of multiple types of HPV DNA sequences in cervical carcinoma was determined in Chinese citizens living in two different geographical locations where the incidences of cervical carcinoma are either relatively low or extremely high. HPV DNA sequences were found in 88.5% (54 of 61) of Chinese cervical carcinoma patients living in Taiwan, where the prevalence of cervical carcinoma is 23.7 per 100,000 women. In contrast, in LueYang in Shanxi province, an area with a very high prevalence of cervical carcinoma (1,026 per 100,000 women), only 57.1% (28 of 49) of Chinese cervical carcinoma patients were found to be infected with genital HPV. This result seems to suggest that either the presence of HPV may have different implications in different populations or HPV infection may not be the only factor that determines the development of cervical carcinoma, at least in certain geographical areas. Recently acquired transient or chronic persistent HPV infection may have a different outcome with regard to cervical carcinogenesis. Alternatively, other factors, such as host determinants, may play a role in the development of cervical carcinoma.

Age Factors↗
PubMed1994

[Study of histopathological and ultrastructural differences between condylomata acuminata and pseudocondyloma of vulvae].

Histopathological alterations of condylomata acuminata were characterized by hyperkeratosis, parakeratosis, acanthosis, elongation of the rete ridges, pseudoepitheliomatous hyperplasia, discrete or grouped koilocytes, proliferation and dilatation of dermal capillaries, lymphocytic and histocytic infiltration around dermal capillaries. Histopathological pattern of pseudocondyloma of vulvae were characterized by finger-shaped configuration, epithelium was similar to normal of mucous membrane without atypia. The lesion was composed of a rich vascular network surrounded by connective tissue and a mild lymphocytic infiltration. Ultrastructural alterations of condylomata acuminata were characterized by proliferation of basal cells, enlarged and swollen nuclei in all layers, 1-4 large nucleoli, 1-3 nuclear bodies, interchromatin granules and perichromatin granules in some proliferating nuclei, swollen mitochondria, dilated endoplasmic reticulum, and dissolved glycogen. Ultrastructural alterations of pseudocondyloma of vulvae were characterized by proliferation of mucomembranous epithelial cells, mild swollen nuclei, 1-2 nucleoli, no nuclear body interchromatin and perichromatin granule, the dilatation of interstitial capillaries, and abundant fibril bundles in the dermis. Thus, the histopathological and ultrastructural manifestations of condylomata acuminata and pseudocondyloma of vulvae were significantly different. It may be of help in differentiation between the two disease.

Adolescent↗
PubMed1993

[Molecular and ultrastructural study on the relationship between human papillomavirus and female genital condyloma in China].

From the results of DNA hybridization, it has been shown that there is a close relationship between HPV 16 and human uterine cervical carcinoma in China, and also that the viral DNA is integrated into the cancer cell genome. Genital condyloma revealed a high positive hybridization rate with HPV 11 DNA, and the viral DNA presented as an episome apart from the cell genome. Under the electron microscope, the inter and perichromatin granules as well as nuclear bodies were observed in all biopsies with positive hybridization, but no HPV particle was found in cancer cells, besides these two kinds of chromatin granules. Human papillomavirus nucleocapsid particles were observed in the nuclei of some genital condyloma cells. Electron-dense matrix aggregates of different sizes were seen in the perinuclear cytoplasm and in the nuclei. This kind of structure may be related to the process of HPV maturity, but its nature remains to be studied.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Validation of the in vitro gastrointestinal (IVG) method to estimate relative bioavailable lead in contaminated soils.

The effect of the dosing vehicle (e.g., dough) on the ability of an in vitro gastrointestinal (IVG) method to predict relative bioavailable Pb associated with soil ingestion was evaluated. Bioaccessible Pb determined by the IVG method was compared with relative bioavailable Pb measured from dosing trials using juvenile swine for 18 contaminated soils ranging from 1270 to 14200 mg Pb kg(-1). Bioaccessible Pb was measured in the IVG gastric extraction (GE) and intestinal extraction (IE) solutions. Mean bioaccessible Pb values were 32.2% for GE without dough, 23.0% for GE with dough, 1.06% for IE without dough, and 0.56% for IE with dough. It is possible that phytic acid associated with the dough addition decreased bioaccessible Pb. In vivo relative bioavailable Pb ranges for different swine tissues were 1 to 87% for blood, 0 to 110% for liver, 1 to 124% for kidney, and 0.04 to 94% for bone. Strong linear relationships between IVG GE Pb with dough (r > 0.76, P < 0.0002), IVG IE Pb with dough (r > 0.56, P < 0.015), and IVG GE Pb without dough (r > 0.81, P < 0.0001) and in vivo bioavailable Pb as estimated with blood, kidney, liver, and bone were found. Inexpensive in vitro methods may be useful in providing an estimate of the variability in relative bioavailable Pb at a single study site. The IVG method can be used to estimate relative bioavailable Pb, As, and Cd in contaminated soil.

Administration, Oral↗