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Biomedical subjects

X Z Li

Publications and source records attributed to X Z Li.

At least 73 records · Page 4Linked to original sources
PubMed1989

Autoantibodies to the major nucleolar phosphoprotein B23 define a novel subset of patients with anticardiolipin antibodies.

Of 164 sera with antinucleolar antibodies, 7 (4.3%) were shown by Western blotting to react with a 37-kd polypeptide in a nuclear extract of HeLa cells and with the recombinant protein expressed by a complementary DNA clone encoding the major nucleolar protein B23. Six of the 7 sera (86%) had antibodies to cardiolipin (aCL), and the sample that was negative for aCL had had lupus anticoagulant on previous testing. All 7 patients had either systemic lupus erythematosus (SLE) or a variant of SLE, suggesting that anti-B23 identifies a subset of patients with SLE associated with a high frequency of aCL.

Adult↗
PubMed1989

[A case of hepatoid adenocarcinoma of the stomach].

A patient, male, 57 years old, with hepatoid adenocarcinoma of the stomach is reported. Chief complaint was right upper abdominal mass and anorexia for 11 months. The patient's serum AFP level was found to be elevated (652.8 ng/ml) and a mass was observed in left hepatic lobe by isotope scan. It was diagnosed as primary hepatic carcinoma. A large ulcerative tumor (14 x 13 x 0.8 cm) in gastric pylorus-antrum and liver metastasis were found by autopsy. Histologically, the tumor, diagnosed as hepatoid adenocarcinoma of the stomach by pathology, was composed of two but closely related to well differentiated tubular papillary adenocarcinoma and differentiated hepatoid adenocarcinoma. Histogenesis, production of AFP and its significance, and clinicopathologic characteristics of this tumor are discussed with review of literature.

Adenocarcinoma↗
PubMed1989

Viral etiology of cervical carcinoma. Human papilloma virus and herpes simplex virus type 2.

The possible role of human papilloma virus (HPV) and herpes simplex virus type 2 (HSV-2) in the viral etiology of cervical carcinoma was investigated a series of cervical lesions were studied for the presence of HPV and HSV-2 DNA sequences as well as HPV and HSV-2 antigens by DNA dot blot hybridization technique and high-specificity PAP staining method. The results obtained were correlated with the histologic diagnosis. HPV 16 DNA sequences detected in cervical carcinoma biopsies were 43%, whereas HSV-2 DNA sequences were only 8%. HPV antigens detected in cervical dysplasia were 31%, whereas those detected in cervical carcinoma and cervicitis were the least. HSV-2 antigens were detected in chronic cervicitis, dysplasia and cervical carcinoma. The difference in positive rate between the cervical carcinoma and cervicitis groups was statistically significant, (chi-square test, P less than 0.01). No HPV DNA and HSV-2 DNA sequences were found in the same specimen, although both HPV DNA sequences and HSV-2 antigens were found in the same sample in some cases. The results indicate that the viral etiology of cervical carcinoma may be multifactorial. Both HSV-2 and HPV may be associated with cervical carcinoma, but the mechanisms involved are different. HSV-2 and HPV may act synergistically in the development of cervical carcinoma.

Antigens, Viral, Tumor↗
PubMed1989

[Elimination of poison from Halitum violaceum by processing].

The contents of polysulphides in different forms of Halitum violaceum (unprocessed, processed with vinegar, calcinated and boiled with water) were determined indirectly by UV spectrophotometry. The results showed that the unprocessed forms are higher in the contents of polysulphides while the processed ones have little or no such contents at all. It is thus believed that the poisons can be eliminated from Halitum violaceum by processing, which helps to decrease or eliminate polysulphides and sulphides.

Hot Temperature↗
PubMed1988

Synergistic effect of hydroxyurea and excessive thymidine on the expression of the common fragile sites at 3p14 and 16q23.

There is a synergistic effect between hydroxyurea (HU) and high concentrations of thymidine (TdR) on the induction of the common fragile sites at 3p14 and 16q23. The frequencies of expression of these fragile sites were significantly higher than in the controls when excessive TdR (0.5 mM) and HU (4 mM) were added into lymphocyte cultures in MEM medium 24 h and 2 h before harvest. Two conditions for the maximum expression of common fragile sites, such as fra(3)(p14), fra(16)(q23) are discussed. The TdR-HU fra(3)(p14)-inducing system might be modified effectively and consistently to improve the prenatal diagnosis of the fragile X syndrome.

Chromosome Fragile Sites↗
PubMed1987

The effect of hydroxyurea on the expression of the common fragile site at 3p14.

Hydroxyurea (HU) is an inhibitor of DNA synthesis, which can inhibit the enzyme ribonucleotide reductase, reduce the syntheses of all four deoxyribonucleoside diphosphates (dNDP), and disturb the balance of the dNTP pool. We have studied the effect of HU on the common fragile site at 3p14 (FRA3B) and have found that G2 treatment with HU increased not only the frequency of chromosomal aberration but also the expression of FRA3B in both complete and folate deficient media. There is a synergistic effect between HU and growth in folate deficient medium on the induction of FRA3B. Our results suggest that the inhibition of DNA repair, including the inhibition in G2 phase, plays an important role in the expression of FRA3B, supporting other authors' data on the effect of other DNA repair inhibitors, such as aphidicolin, caffeine, 1-beta-D-arabinofuranosylcytosine, and 5-fluorodeoxyuridine, on the expression of FRA3B.

Caffeine↗
PubMed1986

The effect of 1-beta-D-arabinofuranosyl-cytosine on the expression of the common fragile site at 3p14.

The effect of the G2-treatment of 1-beta-D-arabino-furanosyl-cytosine (araC) on the expression of the common fragile site at 3p14 (FRA3B) was studied. A significantly increased frequency of FRA3B induced by G2 treatment of araC was found in the lymphocytes grown in folate-deficient medium (positive rate 100%). A relatively low frequency of FRA3B was also induced in the cultures with folate in four of the seven subjects. There is a synergistic effect between araC and growth in folate-deficient medium on the induction of FRA3B. The results suggest that the DNA lesions related to the expression of FRA3B induce the long-patch repair and that the low DNA polymerase alpha activity and inefficient repair process during G2 phase is involved in the expression of FRA3B.

Cells, Cultured↗
PubMed1986

Folic acid and chromosome breakage. III. Types and frequencies of spontaneous chromosome aberrations in proliferating lymphocytes.

The types and frequencies of spontaneous chromosome aberrations were studied in human lymphocytes cultured for 96 h in minimal essential medium (MEM) or MEM without folic acid (MEM-FA). In both media, the most frequent aberrations were chromatid gaps, isochromatid gaps and chromatid breaks. Chromosome (isochromatid) breaks and dicentrics were seen less frequently. Neither of these less frequent aberrations was seen in 4000 cells from MEM, but both were seen in 4000 cells from MEM-FA.

Cells, Cultured↗
PubMed1986

Identification of human N-ras as the common oncogene in NIH 3T3 cells transformed with DNAs from human primary hepatic cancer and hepatoma 7402 line.

DNA was extracted from NIH 3T3 cells transformed with DNAs from human primary hepatic cancer (PHC) and Hepatoma 7402 cell line. The transformant DNA was analyzed by Southern transfer and hybridization with 32P-labeled probes of various oncogenes. The EcoRI 7.2 and 9.0 kb bands characteristic of human N-ras gene were identified in transformed NIH 3T3 cells derived both from PHC and 7402 DNA. The BamHI 6.6 kb band characteristic of human c-Ha-ras I was present only in 7402 transformants, but not in PHC transformants. Using 35S-methionine incorporation, immunoprecipitation with anti-p21 monoclonal antibodies, SDS-PAGE and autoradiography, it was demonstrated that p21 synthesis was remarkably enhanced in 7402 cells as well as in transformed cells derived from both 7402 and PHC DNA. Taking the data together, it strongly implies that N-ras is one of the transforming genes for human liver cancer.

Animals↗
PubMed1986

Expression of N-ras gene in human primary hepatocarcinoma.

Poly(A)+ RNA was isolated from 9 specimens of human primary hepatic carcinoma, 1 non-tumorous liver tissue adjacent to cancer and 1 normal liver tissue samples. The Oligo-dT cellulose-purified poly(A)+ RNAs were subjected to formaldehyde agarose gel electrophoresis, Northern transfer and hybridization with various oncogene probes. Two RNA species, 5.6 kb and 2.2 kb were identified by N-ras gene hybridization in 6 out of 9 mRNA samples from primary hepatic carcinoma specimen. N-ras specific mRNA was not detectable in mRNA samples from normal human liver and tumor surrounding cirrhotic tissue. No detectable hybridization of mRNA from hepatoma and normal liver with Ki-ras or Ha-ras was observed. As human N-ras gene has been identified in DNA of mouse transfectants transformed with PHC DNA, it strongly suggests that N-ras gene might be responsible for the transforming activity of part of cases of human liver cancer.

Carcinoma, Hepatocellular↗