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Biomedical subjects

J Cao

Publications and source records attributed to J Cao.

At least 235 records · Page 13Linked to original sources
PubMed1997

[Atypical manigioma].

Most meningiomas have typical clinical and CT features. But some meningiomas which have an atypical clinical and CT findings can lead to a wrong diagnosis. The authors have reviewed 123 hospitalized patients with meningiomas which had been pathologically diagnosed. Nine of them had atypical meningiomas according to their histories, symptoms, signs and CT findings. All of these patients were mis diagnosed as having gliomas or metastatic tumors. The authors analyed these cases carefully and find the clues that may help to do an accurate preoperative diagnosis.

Adult↗
PubMed1997

[Clinical study of expandable venous stents for treatment of Budd-Chiari syndrome].

Expandable venous stents is a new method for treatment of Budd-Chiari syndrome (BCS). Ten cases of BCS underwent expandable venous stents in inferior cava vein or/and in hepatic vein, or/and intrahepatic portosystemic shunt according to the location and the extent of lesion. Expandable venous stents were successful in all patients. No serious procedure-related complications were observed. The symptoms and signs disappeared. Portal pressure and inferior cava vein pressure gradient reduced immediately after treatment. The blood in stents flowed quickly. During follow-up of 1-21 months, rebleeding was observed in one case. The stenoses of intrahepatic shunts and inferior vena vein respectively occurred in two cases requiring repeat intervention. Therefore, expandable venous stent is safe and effective in patients with BCS, and will be of great value in wide application and further study.

Budd-Chiari Syndrome↗
PubMed1997

[Application of preoperative angiography in diagnosis of gastric cancer].

To improve preoperative diagnosis of gastric cancer, we applied DSA in clinical diagnosis. 36 patients with gastric cancer were observed. Preoperative DSA and postoperative pathological analysis revealed the following results. With DSA, the accuracy of diagnosis of invasion depth of gastric cancer reached 72.2%. We summarised the criteria for diagnosis of gastric cancer. If subsidiary anastomotic channels narrow or obliterate in DSA, the case may be early cancer. If parietal branches narrow or obliterate in DSA, the cancer may invade the muscle of the stomach. If arcade of this lesser curvature narrows in DSA, the cancer may invade the serosa of the stomach. If the roots of main vascular vessels, such as the left gastric artery, and vascular vessels of other organs narrow or obliterate in DSA, the cancer may directly invade other organs as well. Two-thirds of gastric cancer could be identified through DSA with their shapes and characteristics. The varied shapes of vascular vessels caused by invasion of gastric cancer could reveal growing mode of the cancer.

Adult↗
PubMed1997

[Inhibition effect of p53 antisense RNA on malignant phenotype of colorectal cancer cells].

OBJECTIVE: Inhibition effect of p53 antisense RNA on malignant phenotype of colorectal cancer cells was studied. METHODS: For the purpose of inhibiting tumorigenecity of mutant p53 gene in colorectal cancer cells, a 2.1 kb human p53 full length cDNA was inserted into a mammalian expression vector pREP9 to make a p53 antisense RNA expression vector pREP9-p53 (AS). pREP9-p53 (AS) was then introduced into human colorectal cancer cell line SW1116 (with mutated endogenous p53). MTT method and FCM analysis were performed to measure the effect of p53 antisense RNA expressed by pREP9-p53 (AS) on SW1116 cell cycle progression. RESULTS AND CONCLUSION: It was shown that the growth rate of SW1116 cells with pREP9-p53 (AS) was significantly suppressed by the expression of p53 antisense RNA as compared to the control SW1116 cells and SW1116 cells with pREP9 vector alone. FCM analysis showed that SW1116 cells with pREP9-p53 (AS) were arrested at G0/1 phase, whereas no significant influence can be observed on control SW1116 cells with pREP9.

Cell Division↗
PubMed1997

[Ten-case report on primary cervical lymphoma].

OBJECTIVE AND METHODS: Clinical feature, treatment and prognosis of primary cervical lymphoma: are retrospectively analysied. RESULTS: The disease is rare, comprising about 0.9% of all primary cervical malignancies. The average age was 43.6 years. Seven cases had history of familial carcinoma. The complaints: abnormal vaginal bleeding and/or vaginal discharge. The usual pattern of growth was endophytic or polypoid. By FIGO cervical cancer, staging system, there were 8/10 stage I b, 1/10 stage II b and 1/10 stage IV. Histologically all were NHL, B cell lesions(7/10) were the diffuse, cleaved or cleaved-noncleaved cell type. Combination of surgery and chemotherapy were used for 9 of these 10 patients. The follow-up period was 3-66 months. Only one patient had relapse 41 months after the treatment while, others (9/10) survived with no evidence of the disease. CONCLUSION: The prognosis is favorable if cervical lymphoma is discovered early and treated properly.

Adult↗
PubMed1997

[Quantitative determination of 7-ketocholesterol in human fetal liver cell supernatant and lysate by high performance liquid chromatography].

7-Ketocholesterol (7-KC), which is a major oxidation product of cholesterol and is selective cytotoxic to tumour cells, was isolated from human fetal liver. A fast, sensitive method of high performance liquid chromatography for the quantitation of 7-KC has been developed and applied to the determination of 7-KC in human fetal liver cell suspension. In this procedure a mixture of 2 : 1 chloroform-methanol (V/V) was used as extraction solvent. The extract was washed with distilled water and then evaporated to dryness under N2. An adsorption liquid chromatographic system used included mu-Porasil SiO2 column, hexane : iso-propanol (91 : 9) mobile phase and UV detector at 233nm. It was found that the level of 7-KC in human fetal liver cell supernatant was higher than in liver lysate.

Chromatography, High Pressure Liquid↗
PubMed1997

Studies of esophageal balloon cytology in Linxian, China.

Esophageal cancer is the second leading cause of cancer death in China. Esophageal cancer has a very poor prognosis, principally because most tumors are asymptomatic until they are unresectable. Esophageal balloon cytology is an early detection method developed by Chinese scientists to identify resectable early cancers and precursor lesions. Previous studies have reported high sensitivities for detecting esophageal cancer in symptomatic patients. The current report describes several studies evaluating this diagnostic technique in asymptomatic individuals. A comparison of Chinese and U. S. cytological diagnoses of the same esophageal samples showed that the Chinese categories of precancerous neoplasia were more inclusive than the corresponding U. S. categories. Comparisons of both Chinese and U. S. cytological diagnoses with concurrent histological findings showed low (14-36%) sensitivities for the cytological detection of biopsy-proven cancers. Prospective follow-up studies of several screened cohorts showed a consistent progression of risk for developing esophageal cancer with increasing severity of initial cytological diagnosis. These preliminary studies suggest that esophageal balloon cytology is a useful technique that can benefit from additional research to improve its optimal performance.

Adult↗
PubMed1997

Relationship of polymorphonuclear leukocytes to capillary dropout in the human diabetic choroid.

Capillary dropout is an initial event in diabetic retinopathy, but the etiology is unknown. Recent evidence suggests that similar events may occur in the diabetic choroid. We have developed a method to evaluate the relationship between the polymorphonuclear leukocytes (PMNs) and capillary dropout in the human diabetic choroid using alkaline phosphatase (APase) histochemistry to label blood vessels and nonspecific esterase activity to identify PMNs. The number and distribution of PMNs in diabetic and nondiabetic choroidal capillaries (choriocapillaris) were analyzed in the flat perspective and the tissue then flat embedded in glycol methacrylate for histological sectioning. The total number of PMNs was increased within the choriocapillaris in five diabetic eyes (170.9 +/- 12.9 PMNs/mm2 of choroid) compared with five nondiabetic eyes (84.2 +/- 16.9 PMNs/mm2; P < 0.001). PMNs were almost always within blood vessel lumens and not in interstitial tissue. In the diabetic choroid, increased numbers of PMNs were present in areas of choriocapillaris with pathological changes (loss in APase activity and choroidal neovascularization) compared with nonpathological choriocapillaris (205.1 +/- 46.9 PMNs/mm2 in pathological versus 152.3 +/- 23.4 PMNs/mm2 in nonpathological areas; P < 0.001). PMNs were often queued up within the lumens of capillaries, demonstrating loss in APase activity. We have observed an increased number of PMNs in diabetic choroid compared with control nondiabetic choroids, and PMNs in diabetic choroid were associated with loss in APase activity, which was related to loss in viable endothelial cells. The results suggest that PMNs contribute to vaso-occlusive processes and endothelial cell injury in the diabetic choroid.

Aged↗
PubMed1997

Isotypic antibody responses of a population in an endemic area of schistosomiasis japonica and their epidemiologic significance.

The present study was designed to explore if there exists a correlation between predominant isotype-defined antibody levels and reinfection in low age groups of the population in an endemic area of schistosomiasis japonica in China. One hundred and thirty-eight individuals aged 3-25 years old were selected for serological investigations including the levels of IgG, IgG4, IgM and IgE, detected by ELISA with soluble egg antigen and soluble adult worm antigen. Results show that age is a determinant for SEA-specific IgG, IgG4, and IgE, and SWA-specific IgG and IgG4 antibody levels, which increased with age, and that SEA- and SWA- specific IgG4 antibody levels are risk factors of reinfection, ie, the risk of reinfection occurrence of the population with high level of SEA or SWA-specific IgG4 is 2.83 or 2.40 times, respectively, that with low level of SEA or SWA-specific IgG4, suggesting that in the endemic area of schistosomiasis japonica, there exists a possibility that in the population aged 3-25 years, SEA and SWA-specific IgG4 antibodies mediate a blocking immunity response.

Adolescent↗
PubMed1997

Screening and identification of down-regulated genes in colorectal carcinoma by subtractive hybridization: a method to identify putative tumor suppressor genes.

OBJECTIVE: To search for new putative tumor suppressor genes in colorectal carcinoma. METHODS: Subtractive hybridization technologies were applied to screen and select genes, the expression of which was down-regulated in colorectal carcinoma. mRNAs uniquely expressed in normal cells but not in colorectal carcinoma were recovered as cDNA (sub-cDNA) after two rounds of subtractive hybridization with mRNA prepared from colorectal carcinoma. The sub-cDNAs were then used as probes to screen a normal human colon cDNA library constructed in lambda-Zap II phage. The DNAs of positive clones were in vivo excised, and partial DNA sequences were analyzed and compared with DNA sequence database Genbank. RESULTS: A total of 46 different clones with an average of about 1 kilobases in transcript size was recovered. Among these 46 down-regulated genes in colorectal carcinoma were genes encoding immunoglobulin (n = 32), 40-kDa keratin intermediate filamentous protein or IFP (n = 1), major histocompatibility complex-related protein (n = 1), unrelated structural proteins (n = 10) and gene products yet to be identified (n = 2). RNA dotblot hybridizations confirmed that all 46 clones contained genes that were down-regulated and have not been reported before in colorectal carcinoma. CONCLUSION: The results of this study suggested that the 46 clones were down-regulated in colorectal carcinoma, they should be further studied as new putative tumor suppressor genes and could be used as new tumor markers of colorectal carcinoma.

Colorectal Neoplasms↗
PubMed1997

[Application of subtractive hybridization in screening for colorectal cancer negatively related genes].

OBJECTIVE: To search previously uncertained factors that corelated with the occurence and development of human colorectal cancer. METHOD: Subtractive hybridization technique was employed to screen down-regulated genes of colorectal cancer. RESULTS: We obtained 46 clones which highly were expressed in normal intestinal mucosa but much lower or none in colorectal cancer. Two of the 46 clones, SCN6 and SCN19, were accepted by the Genbank Database as novel genes with the accession numbers U17714 and U20248. Full length cDNA (2932bp) of SNC6 was sequenced, and supposed to encode a protein comprised 271 amino acids, MW30kd, which shared less than 30% homology with the protein database. The gene was localized to human chromosome 22q13. RNA dot blot analysis showed that the expression level of SNC6 was lower in colorectal cancer than in normal intestinal mucosa, and similar results were found in breast cancer. Northern blot showed higher expression levels of SNC6 in liver, lung, prostate, testis, ovary and K562 cell line than in other tissues. CONCLUSION: SNC6 can be further investigated as a novel colorectal cancer negatively related gene.

Colonic Neoplasms↗
PubMed1997

[The induction and the prevention of Vi antigen of S.typhi loss by three metalic ions of salts].

Three metalic salts Ferrous, Mgnesium and Calcium were used to induce and to prevent Vi antigen of S. typhi loss. All of the 96 Vi-II phage typing standard strains belonged to V type (a recovery rate of 100%). Out of 1320 local strains, 1292 were type V (a recovery rate of 97.7%) and 28 remained type W with a Vi loss rate of 2.1%. The results showed that induction and prevention of Vi antigen of S. typhi loss by the three metalic salts was higher than that of other reports which showed a loss rate of 5% Vi antigen of S. typhi.

Animals↗
PubMed1996

Membrane type matrix metalloproteinase 1 activates pro-gelatinase A without furin cleavage of the N-terminal domain.

Membrane type matrix metalloproteinase 1 (MT-MMP1), a novel 63-kDa member of the matrix metalloproteinase family, is a membrane-anchored enzyme and an activator for gelatinase A. In addition to its C-terminal hydrophobic transmembrane domain, MT-MMP1 has an insertion of 11 amino acids between its propeptide and catalytic domain encrypted with a RRKR recognition motif for the paired basic amino acid cleaving enzyme, furin. In this report, we investigated whether the cleavage of the RRKR motif of MT-MMP1 by Golgi-associated furin is analogous to a similar enzyme activation mechanism observed with stromelysin-3. Mutant forms of MT-MMP1 were cotransfected into COS-1 cells with cDNAs for pro-gelatinase A and/or furin. Immunoprecipitation and immunoblotting using specific antibodies were employed to characterize cell proteins. Whereas furin readily cleaved soluble MT-MMP1 lacking the transmembrane domain (DeltaMT-MMP1), a soluble stromelysin-1/DeltaMT-MMP1 chimera without the RRKR basic motif was resistant to furin-induced cleavage. COS-1 cells cotransfected with wild type MT-MMP1 cDNA and furin cDNA demonstrated a 63-kDa protein (latent enzyme) on SDS-polyacrylamide gel electrophoresis rather than the anticipated lower molecular weight activated enzyme. Inhibition of furin activity with alpha1-protease inhibitorPittsburgh (a furin inhibitor) did not affect the pro-gelatinase A activation mechanism in COS-1 cells cotransfected with MT-MMP1 and pro-gelatinase A cDNAs. Furthermore, substitution of the RRKR motif of MT-MMP1 with alanine residues by site-directed mutagenesis resulted in the same 63-kDa protein without loss of pro-gelatinase A activation function. These data indicate that furin-induced activation of MT-MMP1 is not a prerequisite for pro-gelatinase A activation. The mechanism of activation of cell-bound MT-MMP1 remains to be elucidated.

Animals↗
PubMed1996

Reversal of P-glycoprotein-mediated multidrug resistance by a potent cyclopropyldibenzosuberane modulator, LY335979.

Overexpression of P-glycoprotein (Pgp) by tumors results in multidrug resistance (MDR) to structurally unrelated oncolytics. MDR cells may be sensitized to these oncolytics when treated with a Pgp modulator. The present study evaluates LY335979 as a modulator both in vitro and in vivo. LY335979 (0.1 microM) fully restored sensitivity to vinblastine, doxorubicin (Dox), etoposide, and Taxol in CEM/VLB100 cells. LY335979 modulated Dox cytotoxicity even when LY335979 (0.5 microM) was removed 24 h prior to the cytotoxicity assay. LY335979 blocked [3H]azidopine photoaffinity labeling of the M(r) approximately 170,000 Pgp in CEM/VLB100 plasma membranes and competitively inhibited equilibrium binding of [3H]vinblastine to Pgp (Ki of approximately 0.06 microM). Treatment of mice bearing P388/ADR murine leukemia cells with LY335979 in combination with Dox or etoposide gave a significant increase in life span with no apparent alteration of pharmacokinetics. LY335979 also enhanced the antitumor activity of Taxol in a MDR human non-small cell lung carcinoma nude mouse xenograft model. Thus, LY335979 is an extremely potent, efficacious modulator that apparently lacks pharmacokinetic interactions with coadministered anticancer drugs and is, therefore, an exciting new agent for clinical evaluation for reversal of Pgp-associated MDR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Xu et al. Reply.

Explore the source record for details and available documents.

Journal Article↗
PubMed1996

Requirement of a corepressor for Dr1-mediated repression of transcription.

A Dr1-associated polypeptide (DRAP1) was isolated from HeLa cells and found to function as a corepressor of transcription. Corepressor function requires an interaction between DRAP1 and Dr1. Heterodimer formation was dependent on a histone fold motif present at the amino terminus of both polypeptides. Association of DRAP1 with Dr1 results in higher stability of the Dr1-TBP-TATA motif complex and precluded the entry of TFIIA and/or TFIIB to preinitiation complexes. DRAP1 was found to be expressed in all tissues analyzed with higher levels in tissues with a low mitotic index. Analysis of DRAP1 in the developing brain of rat demonstrated undetectable levels of DRAP1 in actively dividing cells but high levels of DRAP1 expression in differentiated non dividing cells. Dr1 was immunodetected in all cells analyzed. A model for DRAP1-dependent, Dr1-mediated repression of transcription is proposed.

Amino Acid Sequence↗
PubMed1996

VH gene usage is multiple myeloma: complete absence of the VH4.21 (VH4-34) gene.

The immunoglobin heavy chain variable region (VH) gene usage in multiple myeloma (MM) has not been reported, although a few studies have incidentally identified the VH gene rearranged in small cohorts of MM patients. We used a reverse transcriptase-polymerase chain reaction based technique to analyze the VH gene usage in MM. The VH sequences were obtained after amplification of bone marrow cDNA using the seven VH family-specific and constant region primers. The VH sequences of 72 patients were successfully identified. The frequency of VH family usage in decreasing order was VH3>VH4>VH1>VH5>VH2>VH6>VH7 and corresponded to the functional germline complexity of the VH families. Individual VH genes (VH1-69, VH3-9, VH3-23, and VH3-30) were overrepresented in our cohort of MM patients; some VH genes [VH3-49, VH3-53, and VH4.21 (VH4-34)], which are rearranged with increased frequency in normal circulating B cells, autoimmune diseases, and other B-cell malignancies, were not detected in any MM patient. Compared with germline sequences, an average of 8.8% (range, 2.7% to 16.5%) of the nucleotides had evidence of mutation within each VH sequence. Based on these results, we conclude that (1) the VH gene usage in MM is unique compared with other malignant and nonmalignant B-cell populations, (2) the physiologic process of clonal deletion functions to remove clones that have rearranged VH genes (VH4.21) capable of expressing antibodies, which recognize self-antigens, and (3) the complete lack of VH4.21 gene rearrangement may help to partially explain the paucity of autoimmune phenomena in MM.

Base Sequence↗