Biomedical subjects

Y Gao

Publications and source records attributed to Y Gao.

At least 235 records · Page 13Linked to original sources

PubMed1999

[Colorectal cancer: lymphatic metastasis and choice of operation].

OBJECTIVE: To study lymphatic metastasis of colorectal cancer for deceding the of dissection extent of dissection. METHODS: Six hundred and twenty-three lymph nodes from 74 cases of colorectal cancer were analyzed after D(3) resection. They were classified into peritumor, longitudinal spread, and upward spread groups. The metastasis rate of lymph node and its incidence were calculated. RESULTS: The metastasis rate of lymph node and its incidence in the peritumor, longitudinal spread, and upward spread (N(2) and N(3)) groups were 47.2% and 38.6%, 22.8% and 18.6%, and 29.7% (20.3% and 9.4%) and 10.2% (19.0% and 5.3%), respectively. The distribution rate of metastatic lymph node was 61.2%, 17.1%, and 21.6% in the peritumor, longitudinal spread, and upward spread groups, respectively. Within 2.0 cm on the anal side of rectal cancer, the metastasis rate was 3.7%, whereas in 2.0 - 4.0 cm no metastasis was observed cancer at the lower part of the rectum demonstrated a higher lateral metastasis rate. CONCLUSIONS: Colorectal cancer tends to metastasize to longitudinal and the risk of metastasis increased in the stage of pT(3) and pT(4) or low differentiation stage. Jump metastasis is also a feature. D(3) radical resection is necessary for colorectal cancer, but extended lateral lymph node needs enectomy or total mesorectal excision. No residual tumor tissue exists at the anastomosis site after low anterior resection when the excision distance is beyond 2.0 cm from the anal margin of rectal cancer.

Adult↗

PubMed1999

[Significance of expression of epidermal growth factor receptor, transforming growth factor beta, c-erbB-2 oncogene in myoepithelioma of salivary gland].

OBJECTIVE: To explore the effect of expression of epidermal growth factor receptor (EGFR), transforming growth factor beta (TGF beta), c-erbB-2 oncogene in myoepithelioma and malignant myoepithelioma. METHODS: 20 cases of myoepithelioma and 20 cases of malignant myoepithelioma were examined by immunohistochemical methods. RESULTS: All cases showed overexpression of EGFR and TGF beta, the intensity of expression didn't associate with the benignity and malignity of tumors. The overexpression of c-erbB-2 oncoprotein was seen in 5 cases of myoepithelioma and 13 cases of malignant myoepithelioma, and the cases of malignant myoepithelioma were stained more intense than that of myoepithelioma. CONCLUSION: The synergy of EGFR and TGFR beta had significant relation to the proliferative and differentiation processes of myoepithelial tumor. The activated c-erbB-2 oncogene, that is similar with EGFR in structure, plays an important promoting role in unrestricted progression of malignant myoepithelioma cells.

Biomarkers, Tumor↗

PubMed1999

[Smoking, related cancers, and other diseases in shanghai: a 10-year prospective study].

OBJECTIVE: To explore the relationship between smoking and related diseases among residents of Shanghai. METHODS: A cross-sectional study on current smoking status among 213,800 residents aged 20 yr and over in Shanghai urban, suburb and rural areas was carried out during the early 1980s. The residents in the urban area were followed up for 12 years (1983 - 1994) and those in suburb and rural areas for 11 years (1984 - 1994). A Poisson regression model was used to estimate relative risks RRs of certain diseases for smoking adjusted for age with their 95% confidence intervals by sex and area among persons aged 40 yr and over at the beginning of the study. RESULTS: In the urban area, the RRs of death for smoking were 1.48 and 1.62 in males and females, respectively and for cancer death were 2.20 and 2.00. Statistically significant elevated RRs were seen for cancers of the lung and liver in both males and females and for cancers of the oesophagus, stomach, pancreas and bladder only in males. Significantly higher RRs were also observed for cerebrovascular disease, chronic bronchitis and emphysema, and pulmonary heart disease. RRs lower than in the urban area were found in the suburb and rural areas. The population attributable risks (%, PAR) for death due to smoking for males were estimated by area. PARs for death were 20.9, 18.9 and 16.3 in urban, suburb and rural areas, respectively. For all cancers, PARs were 40.0, 34.5 and 34.2 and for lung cancer were 71.7, 59.2 and 64.7. CONCLUSION: Smoking was associated with the mortality of some common cancers, chronic bronchitis, and emphysema, pulmonary heart, and cerebrovascular diseases.

China↗

PubMed1999

[A case-control study on relationship between body mass index and lung cancer in non-smoking women].

OBJECTIVE: To investigate the relationship between body mass index (BMI) and lung cancer in non-smoking women. METHODS: A population-based case-control study on lung cancer in non-smoking women was conducted during February 1992 to December 1993 in Shanghai. Totally, 504 cases of lung cancer of non-smoking women and 601 population controls were studied. RESULTS: The risk of lung cancer increased with the decrease of BMI. The odds ratio of lung cancer in non-smoking women was 1.95, as compared to controls with the highest quartile of their BMI, with a dose-response pattern (P < 0.0002 with chi(2) test for trend), adjusted for age, schooling and income. Non-conditional logistic regression analysis was used to adjust for some main risk factors found in other studies carried out at home, such as passive smoking, tea drinking, eye irritation by cooking oil fume, kinds of cooking oils, pulmonary tuberculosis, family history of lung cancer, age of menarche, menstrual cycle and dietary nutrition (including intake of vitamins C and E, beta-carotene, total fat and calorie), was used to adjust. There still existed relationship between BMI and lung cancer in non-smoking women after adjustment for those factors. Stratification analysis showed that there was relationship mainly between BMI and lung adenocarcinoma. CONCLUSION: BMI may be a risk factor for lung cancer in non-smoking women.

Adult↗

PubMed1999

[Infrared spectral identification of rhizoma Corydalis and rhizoma Corydalis repentis].

OBJECTIVE: To study the IR spectra of Rhizoma Corydalis and Rhizoma Corydalis Repentis. METHOD: The petroleum ether, ethyl ether and water extracts obtained by the same isolating procedure from Rhizoma Corydalis and Rhizoma Corydalis Repentis were determined by IR spectrophotometry. RESULTS: The IR spectral evidences of the two samples showed distinct characteristics and good repeatability. CONCLUSION: The IR spectral evidences can be used to differentiate Rhizoma Corydalis and Rhizoma Corydalis Repentis.

Corydalis↗

PubMed1999

[Diagnosis and treatment of internal jugular phlebectasia (three cases report].

OBJECTIVE: To discuss the diagnosis and treatment of patients with rare abnormal veins: the internal jugular phlebectasia. METHODS: Three patients with swollen during straining or crying were diagnosed as internal jugular vein dilatation by ultra-sonography, DSA and MRI. Then an operation of envelopment of the right internal jugular vein with the sternocleidomastoid muscle was performed in two cases. In the third case, the bilateral internal jugular ectasia, the right internal jugular vein were resected and the left internal jugular vein was enveloped with the resected vein. RESULTS: These three patients were treated satisfactorily by operation, and no recurrence in the following two years. CONCLUSION: To those who want their internal jugular phlebectasia to be treated, the operation of envelopment of internal jugular vein with sternocleidomastoid muscle is a good method.

Adolescent↗

PubMed1999

[Influence of pavulon on facial nerve monitoring during middle ear-mastoid operation].

OBJECTIVE: To evaluate the influence of pavulon (muscle relaxant) on facial nerve monitoring for patient with middle ear-mastoid operation during general anesthesia. METHOD: Intraoperative monitoring of the facial nerve (FNM) was done in 45 ears (44 case). For patient with middle ear-mastoid disease, 38 ears underwent inhaled-intravenous anesthesia with muscle relaxant pavulon (group of general anesthesia), 7 ears underwent local anesthesia (group of local anesthesia). Accelography (ACCG) was used in 10 case for testing the correlation between of FNM and the various degree of recovery from ulnar nerve-musculor blockade. RESULT: FNM could be elicited during different periods of recovery with values of T4/T1 varying from 10%-98%. Pavulon could be used to eliminate muscular vibration from disturbing FNM. Electromyography (EMG) potentials were successfully recorded in 34 ears (89.4%). Anesthesia was uneventful and it may be controled satisfactority. CONCLUSION: Considering the advantage of pavulon. It can be used for general anesthesia during intraoperative monitoring of the facial nerve for children or adults suffering from local complicated diseases.

Adolescent↗

PubMed1999

[Determination of beta-carotene in tobacco by HPTLC].

This paper reports the high performance thin-layer chromatography (HPTLC) determination of beta-carotene in tobacco. The developer used was V(benzene):V(acetone) = 4:1. The detection wavelength was 450 nm. The linear range and the detectable limit of the method were 50 ng-0.5 microgram and 20 ng per spot of beta-carotene respectively. The method has been proved to be simple, sensitive, accurate and reproducible.

Chromatography, Thin Layer↗

PubMed1999

[Effects of cyclosporin A combined with T4 on collagen IV production, coll alpha 1 (IV) mRNA and TGF beta 1 mRNA expression in cultured human mesangial cells].

OBJECTIVE: To investigate the effects of single cyclosporin A (CsA), tripcholorlide (T4) or both on renal fibrosis. METHODS: Collagen IV concentrations in the supernatants of human mesangial cells (HMCs) in culture were measured by ELISA. Collagen type IV alpha 1 mRNA (Coll alpha 1 IV mRNA) and transforming growth factor beta 1 (TGF beta 1) mRNA expression were tested by RT-PCR. RESULTS: CsA regulated HMC collagen IV production biphysically, i.e., 1.0 microgram/ml CsA increased collagen synthesis while 0.01-0.1 microgram/ml CsA decreased its formation. T4 enhanced collagen IV production in a dose dependent manner. Combination of the two drugs in lower doses could reach the same degree of immunosuppression as a higher dose of CsA did but with less fibrogenesis. Both CsA and T4 up-regulated HMC Coll alpha 1 (IV) mRNA and TGF beta 1 mRNA expression. The degree of Coll alpha 1 (IV) mRNA expression in different groups were in accordance with that of TGF beta 1 mRNA. CONCLUSIONS: Both CsA and T4 regulate extracellular matrix formation which may be mediated by TGF beta 1. Combination of the two drugs in lower dose results in less fibrosis than a higher dose of CsA.

Cells, Cultured↗

PubMed1999

[The characterization of a novel testis-specific nucleoporin gene].

OBJECTIVE: To investigate the structure and function of testis-specific gene and spermatogenesis in human. METHODS: Screening cDNA expression library, 5' rapid amplification of cDNA ends, Northern blot and fluorescent in situ hybridization(FISH) were used. Gene expressing, purified of expressed protein by affinity chromatography and SDS-PAGE as well as phosphorylation of expressed protein in vitro by PKC and p34cdc2 were observed. RESULTS: A cDNA designated as BS-63 was isolated and found to consist of 2,209 bp with an open reading frame of 2,100 bp and assigned the accession number U64675 by GenBank. The deduced polypeptide consisted of 700 amino acid residues containing XFXFG or FG motifs that were characteristic of nuclear pore complex (NPC) protein and acted as potential binding sites for Ran. The N-terminal region had high homology with Ran BP2/Nup 358, a nucleoporin component, showing that BS-63 was a member of the NPC family. Northern blot analysis of mRNA prepared from various human tissues showed that BS-63 gene was transcribed in two forms: 6.0 and 8.5 kb. The 8.5 kb transcript was present in low amounts in several somatic tissues; whereas the 6.0 kb transcript was expressed only in testis. Analysis by FISH method mapped the BS-63 gene in 2q11.2-12. A protein band with an estimated Mr of 80,000 was detected with E. coli BL21 (DE3) transfected with recombinant plasmid pET30a (+)-BS-63. In vitro phosphorylation test indicated the BS-63 recombinant protein could be phosphorylated by PKC and p34cdc2. CONCLUSIONS: The study was the first demonstration that the BS-63 gene encoding a nucleoporin-related protein with Ran binding sites was expressed in germ cells of human testis.

Amino Acid Sequence↗

PubMed1999

Apoptosis of hemopoietic cells in irradiated mouse bone marrow.

Apoptosis of hemopoietic cells in bone marrow following radiation has been rarely reported, let alone studied quantitatively and pathologically. LACA mice were irradiated with 2.5, 4.0, 5.5, and 7.0 Gy gamma-rays, and the bone marrow was examined at 6 hours, 1 day, and 3 days after radiation. Semi-thin and thin sections were examined by light and electron microscopy. The number and area density of the apoptotic cells were assessed by means of a Cambridge Quantimet 970 Image Analyzer. We found that apoptosis occurred in only a few hemopoietic cells in the control mouse bone marrow, whereas 6 hours after radiation there were many apoptotic hemopoietic cells in each sample of irradiated bone marrow. Compared with controls, both the number and area density of the apoptotic cells markedly increased in the bone marrow of animals in every radiation dose group, and the difference was statistically significant (p < 0.01). Furthermore, the number and area density increased as the radiation dose increased. Our findings suggest that apoptosis is the main mode of radiation-induced hemopoietic cell death.

Animals↗

PubMed1999

Overexpression of c-fos and Rb proteins in radiation-induced skin ulcers.

We established an animal model of radiation-induced skin ulcers in rats irradiated with 35 to 55 Gy y-rays. The pathological changes were observed for 1 year. Immunohistochemical studies were performed on 72 radiation-induced skin ulcer specimens using c-fos and Rb protein polyclonal antibodies. We found that the overexpression rate of c-fos was 45.8% and of Rb was 63.9%. The overexpression of c-fos was mainly seen in the nuclei of activated squamous epithelial cells and in some fibroblasts and endothelial cells of arterioles in the deep part of the skin ulcers. The overexpression of Rb had the same localization. Our results suggest that the changes in c-fos and Rb proteins may be related to the poor healing of radiation-induced skin ulcers.

Animals↗

PubMed1999

Overexpression of c-erbB-2 and EGF-R proteins in radiation-induced skin ulcers.

We established an animal model of radiation-induced skin ulcers in rats irradiated with 35-55Gy gamma-rays. The pathological changes were studied for 1 year. Immunohistochemical studies were performed on 72 radiation-induced skin ulcer specimens using c-erbB-2 and epidermal growth factor receptor (EGF-R) protein antibodies. We found that the overexpression rate of c-erbB2 oncoprotein was 59.7% and of EGF-R was 70.8%. The overexpression of c-erbB-2 was chiefly seen in the activated squamous epithelial cells and in the cytoplasm of fibroblasts, endothelial cells, and leiomyocytes of the arteriolar media in the deep part of the ulcers. The overexpression of EGF-R had the same localizations. It is suggested that the overexpression of c-erbB-2 and EGF-R proteins may be due to the poor healing of the radiation-induced skin ulcers.

Animals↗

PubMed1999

Overexpression of p53 and MDM2 proteins in rat radiation-induced skin ulcers.

We established an animal model of radiation-induced skin ulcer in rats that were locally irradiated with 35 to 55 Gy gamma-rays. The pathological changes were observed for 1 year. Immunohistochemical studies using p53 and MDM2 protein polyclonal antibodies were performed on 72 radiation-induced skin ulcer specimens. The results showed that the overexpression rate of p53 protein was 9.7% and of MDM2 was 19.4%. The overexpression of p53 was chiefly seen in the nuclei of the activated squamous epithelial cells and in the fibroblasts and endothelial cells of arterioles in the deeper part of the skin ulcers. The overexpression of MDM2 had the same localizations. These results suggest that the changes of p53 and MDM2 may be related to the poor healing rate of radiation-induced skin ulcers.

Animals↗

PubMed1998

A critical role for DNA end-joining proteins in both lymphogenesis and neurogenesis.

XRCC4 was identified via a complementation cloning method that employed an ionizing radiation (IR)-sensitive hamster cell line. By gene-targeted mutation, we show that XRCC4 deficiency in primary murine cells causes growth defects, premature senescence, IR sensitivity, and inability to support V(D)J recombination. In mice, XRCC4 deficiency causes late embryonic lethality accompanied by defective lymphogenesis and defective neurogenesis manifested by extensive apoptotic death of newly generated postmitotic neuronal cells. We find similar neuronal developmental defects in embryos that lack DNA ligase IV, an XRCC4-associated protein. Our findings demonstrate that differentiating lymphocytes and neurons strictly require the XRCC4 and DNA ligase IV end-joining proteins and point to the general stage of neuronal development in which these proteins are necessary.

Animals↗

PubMed1998

A multidrug resistance transporter from human MCF-7 breast cancer cells.

MCF-7/AdrVp is a multidrug-resistant human breast cancer subline that displays an ATP-dependent reduction in the intracellular accumulation of anthracycline anticancer drugs in the absence of overexpression of known multidrug resistance transporters such as P glycoprotein or the multidrug resistance protein. RNA fingerprinting led to the identification of a 2.4-kb mRNA that is overexpressed in MCF-7/AdrVp cells relative to parental MCF-7 cells. The mRNA encodes a 655-aa [corrected] member of the ATP-binding cassette superfamily of transporters that we term breast cancer resistance protein (BCRP). Enforced expression of the full-length BCRP cDNA in MCF-7 breast cancer cells confers resistance to mitoxantrone, doxorubicin, and daunorubicin, reduces daunorubicin accumulation and retention, and causes an ATP-dependent enhancement of the efflux of rhodamine 123 in the cloned transfected cells. BCRP is a xenobiotic transporter that appears to play a major role in the multidrug resistance phenotype of MCF-7/AdrVp human breast cancer cells.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

PubMed1998

Antiinflammatory effects of CD95 ligand (FasL)-induced apoptosis.

Apoptosis is critical to homeostasis of multicellular organisms. In immune privileged sites such as the eye, CD95 ligand (FasL)-induced apoptosis controls dangerous inflammatory reactions that can cause blindness. Recently, we demonstrated that apoptotic cell death of inflammatory cells was a prerequisite for the induction of immune deviation after antigen presentation in the eye. In this report, we examine the mechanism by which this takes place. Our results show that Fas- mediated apoptosis of lymphoid cells leads to rapid production of interleukin (IL)-10 in these cells. The apoptotic cells containing IL-10 are responsible for the activation of immune deviation through interaction with antigen-presenting cells (APC). In support of this, we found that apoptotic cells from IL-10(+/+) animals fed to APC in vitro promote Th2 cell differentiation, whereas apoptotic IL-10(-/-) cells, as well as nonapoptotic cells, favor Th1 induction. Thus, apoptotic cell death and tolerance are linked through the production of an antiinflammatory cytokine to prevent dangerous and unwanted immune responses that might compromise organ integrity.

Animals↗

PubMed1998

Tissue factor transcription driven by Egr-1 is a critical mechanism of murine pulmonary fibrin deposition in hypoxia.

Local hypoxemia and stasis trigger thrombosis. We have demonstrated previously that in a murine model of normobaric hypoxia pulmonary fibrin deposition is a result of expression of tissue factor, especially in oxygen-deprived mononuclear phagocytes (MPs). We now show that transcription factor early-growth-response gene product (Egr-1) is rapidly activated in hypoxia, both in vitro and in vivo, and is responsible for transcription and expression of tissue factor in hypoxic lung. MPs and HeLa cells subjected to hypoxia (pO2 approximately 13 torr) had increased levels of tissue factor transcripts (approximately 18-fold) and an increased rate of transcription (approximately 15-fold), based on nuclear run-on analysis. Gel-shift analysis of nuclear extracts from hypoxic MPs and HeLa cells demonstrated increased DNA-binding activity at the serum response region (SRR; -111/+14 bp) of the tissue factor promoter at Egr-1 motifs. Using 32P-labeled Egr consensus oligonucleotide, we observed induction of DNA-binding activity in nuclear extracts from hypoxic lung and HeLa cells because of activation of Egr-1, by means of supershift analysis. Transient transfection of HeLa cells with chimeric plasmids containing wild-type or mutant SRR from the tissue factor promoter showed that intact Sp1 sites are necessary for basal promoter activity, whereas the integrity of Egr-1 sites was required for hypoxia-enhanced expression. A central role for Egr-1 in hypoxia-mediated tissue factor expression was confirmed by experiments with homozygous Egr-1 null mice; wild-type mice subjected to oxygen deprivation expressed tissue factor and showed fibrin deposition, but hypoxic homozygous Egr-1 null mice displayed neither tissue factor nor fibrin. These data delineate a novel biology for hypoxia-induced fibrin deposition, in which oxygen deprivation-induced activation of Egr-1, resulting in expression of tissue factor, has an unexpected and central role.

Animals↗