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Biomedical subjects

L Xu

Publications and source records attributed to L Xu.

At least 667 records · Page 37Linked to original sources
PubMed1995

[The expression of Cath-D, c-erbB-2 and EGFR in breast cancer and its correlation to lymphatic metastasis].

The expression of Cath-D c-erbB-2 and EGFR in breast cancer and its correlation of lymphatic metastases were studied in 277 cases by immunohistochemical technique. Positive staining of Cath-D was detected in 107 cases (38.62%), of which, 89 cases (83.17%) had documented metastasis in the lymph nodes. One hundred and seventy cases (61.38%) stained negative for Cath-D, of which 64 cases (37.64%) had detectable lymphatic metastases. There was a significant difference in the rate of the lymphatic metastases between the Cath-D positive and Cath-D negative groups (P < 0.0001). Fifty-six out of 107 Cath-D positive cases (52.34%) were c-erbB-2 positive as well. However, only 27 out of 170 Cath-D negative cases (15.88%) were c-erbB-2 positive. The positive rate of c-erbB-2 in Cath-D positive group was significantly different from that of Cath-D negative group (P < 0.0001). Among those 107 Cath-D positive cases, 49 cases (45.79%) were EGFR positive. Only 24 cases (14.12%) were EGFR positive among the 170 Cath-D negative cases. The positive rate of EGFR between these two groups was also significantly different (P < 0.0001). The results suggest that Cath-D status can be used as an indicator of the aggressiveness of the breast cancer. Breast cancer cases with a positive Cath-D staining are more likely to have lymphatic metastases and a poor prognosis. Therefore, alternative therapeutic strategies and close follow-ups are needed for these patients.

Adenocarcinoma↗
PubMed1995

[The effects of antitumor agents of croton alkaloids and cisplatin on human red blood cell membranes].

The effects of antitumor drugs of croton alkaloids (CA) extracted from croton, and cisplatin on the structure of human erythrocyte membrane and bovine serum albumin (BSA) were studied with the techniques of circular dichroism, fluorescence spectroscopy and ultraviolet absorption. From measuring circular dichroism between 200-240nm, it was found that the alpha helix of membrane and BSA increased after CA addition. Cisplatin was also found effective in altering membrane alpha helical content. BSA showed a loss of fluorescence intensity and a blue-shift of emission peak after CA addition. The florescence quenching and peak shift may reflect the movement of tryptophan to a more nonpolar environment (the hydrophobic portions of proteins). This is consistent with the increase in helicity of BSA in the presence of CA. From measuring fluorescence polarization of membrane, it was found that membrane fluidity decreased in the presence of CA, but did not change in the presence of cisplatin. The results indicate that both CA and cisplatin lead to alterations in the secondary structure of membrane protein. The conformation change in membrane protein may account for the pharmocological effect of CA and cisplatin.

Alkaloids↗
PubMed1995

The effect of Acanthamoeba concentration on adherence to four types of unworn soft contact lenses.

Contact lens wear is a predominant risk factor for Acanthamoeba keratitis. The exact nature of the relationship between organism concentration and contact lens adherence is poorly understood. We investigated the effect of Acanthamoeba inoculation concentration on adherence to four categories of contact lenses of varying polymers and water content. Acanthamoeba polyphaga was harvested in log growth phase at 5 days subculture and suspended in PBS at concentrations of 1 x 10(2), 10(3), 10(4), 10(5), and 10(6) organisms/mL (trophozoite:cyst ratio 90:10 +/- 2). Sterile unworn polymacon, etafilcon, lidofilcon, and bufilcon contact lens segments were exposed to Acanthamoeba for 2 hours. Acanthamoeba adherence was quantified using phase contrast microscopy. For all lens types, trophozoite adherence increased as the concentration of inoculum increased, but the relationship was not directly proportional. In all cases the minimal adherence was observed at 10(2). Trophozoite adherence increased disproportionate to cysts for all contact lens types. The greatest adherence was to lidofilcon lenses. At all concentrations adherence was greater to lidofilcon than etafilcon or polymacon, and greater to bufilcon than etafilcon or polymacon at the P < 0.01 level. Adherence was significantly greater to lidofilcon than bufilcon only at 1 x 10(5) and 10(6); P < 0.05 (ANOVA). This study suggests that adherence of A. polyphaga to contact lenses increases with the number of organisms in the inoculum, but the relationship is not directly proportional. The number of adherent organisms varies by contact lens type, with the greatest adherence to lidofilcon and the least to etafilcon lenses.

Acanthamoeba↗
PubMed1995

[The investigation on actinomycete population and resources in some areas in Yunnan. IX. The actinomycetes in the west and the northeast of Yunnan].

Two hundred of soil samples of primeval forest, secondary forest, wasteland, nonirrigated farmland, vegetable farmland and paddy farmland were collected from both the west and the northeast of Yunnan in February, 1989. The actinomycetes in the samples were isolated and identified by various methods. This paper discussed the actinomycete population and its difference in the both areas of Yunnan.

Actinomyces↗
PubMed1995

[Chemical compositions of Podocarpus imbricatus].

Twelve components were isolated from Podocar pus imbricatus, of which ten were identified as imbricatafiavone A (1), imbricataflavone B (2), robustaflavone (3), robustaflavone-7"-methyl ether (4), podocarpusflavone A (5), sandaracopimaric acid (6), beta-sitosterol (7), p-hydroxybenzoic acid (8), n-C34H69OH (9) and 10-nonacosanone (10). 4, 5, 8, 9 and 10 are obtained from the species for the first time.

Biflavonoids↗
PubMed1995

[Nationwide survey of the distribution of human parasites in China--infection with parasite species in human population].

The infection rate of main species of parasites and their character by first nationwide survey of human parasites was made. The overall infection rate of human intestinal parasite and the infection rate of most species of parasites were higher in females than that in males. The infection rate according to the age group, the highest infection rate was found in the group aged 5-14 years. With regard to the relation between parasitic infections and occupations of the infected persons, the highest infection rates of Ascaris lumbricoides were exhibited in school children, of hookworm and Clonorchis sinensis were in halfpeasants and halfmerchant and vegetable grower; of Trichuris trichiura were in fishers, of Giardia lamblia, Entamoeba histolytica and Taenia were in herdsmen and halfherdsmen and halfpeasants. In this survey it is also shown that each nationality has their main species of parasites. The family clustering of some main parasites were proved by some province/autonomous region/municipality.

Adolescent↗
PubMed1995

[Studies on amino acid and chemical element in five species of filariae].

Five species of human and domestic animal filariae (B. m, S. d, S. l, S. e, D. i) after lyophilization and hydrolysis were resolved using HPLC and type WFX-IB AAS to determine amino acid (AA) and microelement (ME) content, respectively. The results showed that there were 16 and 17 AA in B. malayi and the animal filariae, respectively. Among AA, the total amount (microgram/mg dry wt.) was markedly higher in animal filariae than that in B. malayi in which the content of acidic and aliphatic AA was significantly higher than those of basic and aromatic AA, respectively. Among five ME (Zn, Cu, Fe, Mn, Cd) and two microelements (Ca, Mg) found in all these filariae. Zn Content was the predominant ME and Ca was much more than Mg.

Amino Acids↗
PubMed1995

[Studies on the enzyme cytochemistry of Toxoplasma gondii and the influence of artemether].

Male mice of Kunming strain were infected with 10,000 tachyzoites intraperitoneally. 2 hours after infection the mice were divided into 2 groups and administered 5% of amylum and 200 mg/kg of artemether by gavage for 8 consecutive days. The ultrastructural enzyme cytochemical studies on cytidine monophosphatase (CMP-ase) and glucose-6-phosphatase (G-6-P-ase) of the parasites were carried out. CMP-ase was found scattered in the lysosomes of the parasites as well as in the macrophages. No differences were observed in the localization and intensity of CMP-ase activity between the nontreated and treated with drug parasites. G-6-P-ase was found surrounding the parasite membrane and scattered in the parasitophorous vacuole in the nontreated parasites. After treatment with artemether, the intensity of G-6-P-ase activity was decreased compared with nontreated control parasites. It is suggested that artemether may exert some action on the G-6-P-ase of T. gondii and thus influence the energy metabolis of the parasite.

Animals↗
PubMed1995

[Characteristics and recent trends in endemicity of human parasitic diseases in China].

An analysis of the nationwide survey of the distribution of human parasites in the light of the literature previously published, two major trends in the endemicity of parasitic diseases in China was observed. For one trend, the infection rate of E. histolytica, Fasciolopsis buski and soil-transmitted helminthasis etc. declined markedly. The second trend was that the prevalence of food-transmitted parasitic diseases (Trichinella spiralis, Clonorchis sinensis, Paragonimiasis, cysticercosis) and hydatidosis was increasing. The relationship between the social economic factors and the two trends were discussed.

Animals↗
PubMed1995

[Surgical treatment of familial acromegaly].

The annual incidence of the acromegaly is three cases per million, and that of the familial acromegaly is even far rarer. The number of familial acromegaly reported in the medical literature of all the world is fewer than 10 cases per year, and up till now none of such a patient has been reported in China. All the three cases of familial acromegaly reported here were from the same family, and showed typical clinical manifestations. They presented the history of acral enlargement, headache, amenorrhoea, elevated serum GH level, enlargement and erosion of pituitary fossa in X-ray and CT scan, and characteristic immunohistochemical findings of GH-secreting pituitary adenoma. All of them underwent successful transsphynoidal total removal of the pituitary adenoma, and recovered well by clinical, endocrine, and pathological criteria. An extended family tree of 65 members excluded consanguinous marriage and suggested that the mode of inheritance was irregular autosomal dominant.

Acromegaly↗
PubMed1995

Treatment of 23 patients with advanced gastric cancer by intravenously transfer of autologous tumor-infiltrating lymphocytes combined with rIL-2.

Tumor-infiltrating lymphocytes (TIL) isolated from metastatic lymph nodes in patients with nonoperable advanced gastric cancer were induced to become LAK-like cytotoxic activity of TIL after in vitro culture with rIL-2. Twenty-three patients with advanced gastric cancer were treated by intravenously transfer of autologous TIL combined with rIL-2. The tumor focus disappeared (complete remission, CR) in 3 patients (13.0%) and significantly decreased (partial remission, PR) in 5 patients (21.7%). Fifteen patients did not respond to the treatment. The amount of soluable IL-2 receptor in serum was significantly decreased after treatment, the cytotoxicity of NK cells and OT test were significantly increased. No significant difference in CD4/CD8 was found between before and after treatment. No serious side effect was observed in the treatment.

Adenocarcinoma↗
PubMed1995

[Antibacterial components of rat uterus].

The acid-soluble extract of rat uterus cavity wall was obtained by washing out the normal Sprague-Dawley rat uterus cavity with 1% acetic acid in the presence of protease inhibitors. When tested for antibacterial activity by sensitive agarose diffusion assay, the extract effectively killed E. coli ML-35P. The bactericidal activity of the acid-soluble extract was further analyzed by gel overlay technique. The result showed that three protein bands, which were designated rat uterus protein 1 (rat UP-1), rat uterus protein 2 (rat UP-2), and rat uterus protein 3 (rat UP-3), were potently antibacterial against E. coli ML-35P. The rat UP-1, rat UP-2, and rat UP-3 accounted for 4.5%, 5.7%, and 6.6% of the total proteins of the rat uterus acid-soluble extract respectively. The lysoplate assay for the determination of lysozyme activity showed that extract had some lysozyme activity, but the activity was very low. AU-PAGE analysis of the extract did not show the presence of lysozyme on the gel. This study suggested that the uterus wall might secrete some currently-unknown antibiotic polypeptides which play an important role in the uterus defense against bacterial infections.

Animals↗
PubMed1995

[Establishment of a new culture system for fetal human tracheobronchus].

Human tracheobronchial tissues were cultured in CMRL 1066 medium containing insulin, hydrocortisone, bovine pituitary extract, and trace elements, with or without fetal bovine serum, in a rocked atmosphere chamber. The morphology of the epithelium remained normal for two months after in organ culture, and then, squamous metaplasia appeared in the epithelium and maintained for more than one year. There were continuous epithelial outgrowths from the human tracheobronchial tissues during the whole duration of organ culture, and the epithelial outgrowth can be subcultured in MCDB 151 medium supplemented with growth factors and grew as a tightly packed monolayer of polygonal cells with the presence of keratin and microvilli. The advantages of organ culture and epithelial cell culture were combined in this new culture system. The new culture model has already been used for the investigation of in vitro transformation of human tracheobronchial epithelial cells by chemical carcinogens in our laboratory.

Bronchi↗
PubMed1995

[The prospective study of trial labor following previous cesarean section].

OBJECTIVE: To investigate the trial of labor following previous cesarean section. METHODS: Three hundred and sixty one cases of pregnant women with history of previous low segment transverse cesarean section were prospectively studied on mode of delivery. 158 cases delivered by elective repeat cesarean section. 203 cases were allowed a trial of labor. RESULTS: 183 out of 203 patients had successful vaginal deliveries. One patient with uterine scar partly ruptured was noted on uterine exploration after delivery. There was no maternal death. The rate of spontaneous vaginal delivery was 79.2%. The rate of vacuum extractor and low forceps deliveries was 20.8%. The 1 minute Apgar score of 170 newborns was > or = 8. Neonatal asphyxia was found in 13 newborns and there was one neonatal death due to congenital abnormality. CONCLUSIONS: Carefully selecting the indication of trial labor and monitoring the labor course are very important for increasing successful vaginal delivery rate and reducing repeat cesarean section.

Adult↗
PubMed1995

[Status and strategy of parasitosis control in preventive health care in China].

According to the result of nationwide human parasitic disease distribution survey, the public significance of parasitosis control was set forth in terms of preventive health care and economic impact as well as parasitosis control and primary health care. A suggestion was made on the control strategy aiming at the parasitosis of priorities listed in the above survey.

China↗
PubMed1995

Effect of 3'-untranslated region on expression of TNF alpha cDNA in Escherichia coli.

A construct pRL-rhTNF alpha 2, in which the 110 bp 3'-untranslated region of rhTNF alpha cDNA was deleted, was transformed in E.coli. The expression level of several positive transformants was determined. The results showed that the expression of pRL-TNF alpha 2 was stable and the biological characteristics of the protein product were the same as that of pRL-rhTNF alpha. Furthermore, the expression level of pRL-rhTNF alpha 2 was increased. It is suggested that the 3'-untranslated region may have some effects on gene expression. A TA-rich sequence, TTTATTA, contained in the 3'-untranslated region of pRL-rhTNF alpha may be involved in the inhibitory effect on gene expression.

Base Sequence↗