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Biomedical subjects

Y Lu

Publications and source records attributed to Y Lu.

At least 649 records · Page 36Linked to original sources
PubMed1997

[Influence of transfection of sense- and antisense-TGF beta 1 gene on human pulmonary giant cell carcinoma cell proliferation].

OBJECTIVE: To investigate the effect of human sense- and antisense-transforming growth factor beta 1 (TGF beta 1) gene on human pulmonary giant cell carcinoma cell (PLA-801D) proliferation. METHODS: PLA-801D cells were transfected with an expression vector containing a full length human sense- or antisense-TGF beta 1 gene by gene transfer. The changes of cell proliferation, expressions of nm23 mRNA and c-myc mRNA and the feature of apoptosis were studied on transfected cells and untransfected cells. RESULTS: The cells transfected by sense-TGF beta 1 gene showed higher TGF beta 1 activity in the conditioned media, growth inhibition in vitro and decreased coloning formation in anchorage-independent assay. The tumorigenic rate was reduced about 47%, the metastasis was inhibited in athymic nude mice as compared with untransfected cells group. The mechanism of such changes described may be associated with the higher expression of nm23 mRNA, and the lower expression of c-myc mRNA as well as the apoptosis in sense-TGF beta 1 gene transfected cells. However, opposing changes were observed in the antisense-TGF beta 1 gene transfected cells. CONCLUSION: TGF beta 1 acts as a negative growth regulator of the PLA-801D in vitro as well as in vivo.

Animals↗
PubMed1997

[TGF beta 1 on murine tumor growth following direct intratumoral injection of plasmid DNA].

OBJECTIVE: To investigate TGF beta 1 gene expression and its effect on murine tumor growth following direct intratumoral injection of naked plasmid DNA encoding human TGF beta 1. METHODS: LM3 murine lung adenocarcinoma cells, were injected subcutaneously to T739 mice and grew to tumor nodules in 2 weeks, Multiple direct intratumoral injections of plasmid DNA, PMAM-neo-TGF beta 1, were given and were compared with saline or vector plasmid administration groups. The growth of tumor was observed till the 8th week when the mice were killed for Northern blot analysis and histopathological study of tumoral tissue. RESULTS: The growth of tumor was boosted in the TGF beta 1 gene treated mice as compared with the control groups, whereas there was no significant difference in the metastatic behavior. Northern blot showed efficient expression of TGF beta 1 mRNA in the treated group. CONCLUSION: TGF beta 1 may stimulate tumor growth in vivo through certain mechanisms. Direct intratumoral injection of nude plasmid DNA may be a promising gene transfer strategy in vivo.

Adenocarcinoma↗
PubMed1997

[Effect of hyaluronan perfusion through the round window on the function and morphology of the inner ear in guinea pigs].

UNLABELLED: In order to study the effect of the hyaluronan (HA) on the inner ear, twenty-six guinea pigs were divided into experimental and control groups, the experimental group were perfused with 2% HA 0.2 ml through the left round window. Auditory and vestibular function were investigated before and 5, 14, 28 days after perfusion. The threshold of action potential (AP) response to filtered clicks (0.25-10 kHz) were elevated at 5 days and were improved (at 1-4 kHz) at 14 days after perfusion (P < 0.05). At 28 days all AP response thresholds had returned to normal (P > 0.05). The nystagmus duration induced by caloric test (ENG) had no obviously change comparing with that of preoperation (P > 0.05). All guinea pigs were sacrificed 28 days after operation. The histology of inner ear were examined by means of membranous labyrinth mapping and temporal bone section after celloidin embedding. The morphology of Corti's and vestibular organs were not significantly damaged after perfusion. IN CONCLUSION: 1) 2%HA caused reversible and temporary changes in auditory function of inner ear; 2) 2%HA lacked ototoxic adverse effects, whereas exerted considerable osmotic effects and a slow dehydration of inner ears.

Action Potentials↗
PubMed1997

[Delayed damage of ionizing radiation on the inner ear].

To investigate the feature and mechanism of delayed effect of ionizing radiation on the inner ear, the function and structure of the inner ear of the guinea pigs were observed during 8 month's period after exposure to fractional doses of gamma radiation (2 Gy per day) with a total dose of 60 Gy. Morphological study was performed using light microscopy, transmission and scanning electron microscopy while the function was measured with electrocochleography (ECochG) and electronystagmography (ENG). The results showed that the mean CAP response threshold was 35.67 +/- 6.78 dB before radiation, and 41.17 +/- 7.76 dB, 47.00 +/- 8.82 dB and 71.00 +/- 7.63 dB at 1st day, 3rd month and 8th months after completion of treatment, respectively. No significant change was demonstrated in the auditory responses at the 1st day of radiation (P > 0.05), but there was obvious hearing loss at 3rd and 8th month (P < 0.01). The nystagmus duration induced by ice water (ENG) was 40.00 +/- 5.44 seconds before radiation, 22.71 +/- 7.93 seconds at 8th month after radiation (P < 0.01). Histologic examination at 8th month after radiation revealed atrophy and degeneration of stria vascularis, a reduced number of capillaries, degeneration of endotheliocyte in vessels, outer hair cell and supporting cell of Corti's organ. The percentage of damaged hair cells in basal turn of the cochlea was significantly higher than those of the upper turn. Degeneration of vestibular hair cell was found. It is suggested that radiation from routine radiotherapy doses may result in a delayed impairment of the inner ear. The main mechanism of the radiation damage may be interference of oxygen supply and metabolism of the inner ear by radiation vascular lesion.

Animals↗
PubMed1997

[Exogenous mtsl/p16 gene suppresses tumorigenicity of human gastric cancer cell line].

OBJECTIVE: To determine the effect on cell growth and tumorigenicity of mstl/p16 gene in human gastric cancer cell line. METHODS: mtsl/p16 gene vector was constructed and transfected into PAMC82 cells which retains down-regulated mtsl/p16 gene expression. Integration and expression of exogenous mtsl/p16 gene were confirmed by PCR, Northern blot, mRNA in situ hybridization and Western blot techniques. Cell morphology was observed in regular culture medium and tumorigenicity in nude mice. RESULTS: The growth of the cells transferred with mtsl/p16 gene (named as PAMCp16) was dramatically inhibited in nude mice as compared to that of the parental PAMC82 cells. Histologically, the tumor grown from PAMCp16 cells was much better differentiated than that from the parental ones. CONCLUSION: Tumorigenicity of a human gastric cancer cell line in nude mice can be inhibited by transduced exogenous mtsl/p16 gene. mtsl/p16 gene may have potential value in gene diagnosis and gene therapy.

Animals↗
PubMed1997

[Extraction and sequencing of trace DNA from cornu Cervi pantotrichum].

The trace DNA extraction method was used to extract DNA from the blood, hair, Cornu cervi pantotrichum, hairy antler of the sika deer, Cervus nippon, and penis of Bulbalus bublis and Asinus vulgaris. A 307 bp fragment of mitochondrial DNA cytochrome b gene was amplified with primers L14841 and H15149 for these extractions. The purified PCR products were sequenced by the dideoxy method. DNA sequence obtained from the Cornu cervi pantotrichum is the same as that obtained from the fresh blood and hair of the sika deer, but the sequence of the so-called hairy antler is quite different, implying that it is not from the sika deer. In addition, the phylogenetic relationships among different species are congruent with the traditional known phylogeny.

Animals↗
PubMed1997

[The development of a multivision glare tester].

This paper presents a new kind of multivision glare tester. Its composition, function, hardware, software and application are introduced. The tester provides a practical tool for evaluating visual function change under glare-producing conditions.

Contrast Sensitivity↗
PubMed1997

[Determination of adenosine and thymidine in Fritillaria bulbs by ultraviolet spectrophotometry].

A convenient method for quantitative analysis of the nucleosides in Fritillaria bulbs has been developed by means of thin layer chromatography and ultraviolet spectrophotometry. The MeOH extracts from four species of Fritillaria were analyzed with this method. The results show that both adenosine and thymidine in the four species are quite disparate, suggesting that the nucleosides may be responsible for the anti-coagulative activity of Fritillaria.

Adenosine↗
PubMed1997

[Studies on X-ray diffraction pattern of traditional Chinese medicinal materials].

Traditional Chinese medicine(TCM) as prescribed by Chinese traditional physicians is usually available as "decoction slices" which calls for a ready method for assessment of quantity or even genuineness. Three groups of TCM drugs (radix Rubiae, bulbus Fritillariae and rhizoma Dioscoreae) were selected by using powder X-ray diffraction analysis with complete absorption profile. Topological regularity and characteristic peaks of the absorption profile were obtained as fingerprint in X-ray diffraction diagrams of the pertinent medicinal materials. We have discovered the similarities of 3 radix Rubiae samples gathered from different localities and their differences with Rubia tinctorum, the similarities and differences between 7 species belonging to Fritillaria Genus, the similarities of 2 rhizoma Dioscoreae samples from different localities and their differences with 2 counterfeits. The result points to a promising prospect in achieving an objective assessment of genuineness at TCM drugs.

Drugs, Chinese Herbal↗
PubMed1997

[Amplification, clone and identification of the specific fragments of tumor metastasis-suppressor gene nm23-H1 and nm23-H2].

A series of DNA primers specific for the specific fragments of nm23-H1 and nm23-H2 were designed and synthesized. The specific fragments of nm23-H1(185 bp) and nm23-H2(145 bp) were amplified from human blood DNA by using polymerase chain reaction (PCR). The recovered PCR products were treated with Klenow fragment, inserted into pGEM-3zf(+) vector with blunt-end ligation, and then transformed into competent cell JM109. The positive colonies were directly identified by colour screening on indicator plates. The recombinant plasmids were digested by Alu I and identified by PCR. The results showed that the authors had obtained the specific fragments of nm23-H1 and nm23-H2 respectively, and these specific fragments could be used for study the expression of nm23-H1 and nm23-H2 seperately.

Cloning, Molecular↗
PubMed1997

[mRNA expression of metastasis-suppressor gene nm23 in carcinoma of buccal mucosa I. Northern blotting study].

In this study the authors detected both nm23-H1 and nm23-H2 mRNA levels in 52 tissues samples of patients with carcinoma of buccal mucosa (CBM) by Northern blotting method. The expression levels of both nm23-H1 and nm23-H2 mRNA in CBM were higher than those in normal buccal mucosa, leukoplakia, adjacent nontumorous mucosa, and lymph nodes with or without metastasis. The nm23-H1 mRNA expression levels in CBM with lymph nodes metastases were lower than those in CBM without metastasis, and were lower in metastatic lympho nodes (P < 0.05). Of the 11 cases with metastases, 9 cases (81.8%) showed low expression of nm23-H1 mRNA, of 19 cases without metastasis, 15 cases (78.9%) were high expression. No significance of nm23-H2 mRNA expression levels were found between CBM with and CBM without metastasis (P > 0.05). The expression of nm23-H1 and nm23-H2 mRNA showed no significant correlation with each clinical-pathological parameter examed. The result suggested that the expression of nm23-H1 mRNA significantly correlated inversely with lymph node metastasis in CBM, while the expression of nm23-H2 mRNA not. nm23 mRNA expression levels can provide a valuable predictor of lymph node metastases in CBM.

Antigens, Neoplasm↗
PubMed1997

[mRNA expression of metastasis-suppressor gene nm23 in carcinoma of buccal mucosa. II. Quantitative reverse transcription PCR amplification].

The nm23 gene is a conspicuous metastasis-suppressor gene. The authors detected both nm23-H1 and nm23-H2 mRNA levels in 47 tissues samples of patients with carcinoma of buccal mucosa (CBM) by quantitative reverse transcription PCR amplification. The results showed that expression levels of both nm23-H1 and nm23-H2 mRNA varied in normal buccal mucosa, leukoplakia, adjacent nontumorous mucosa, submandibular gland, CBM and lymph nodes with or without metastasis. The nm23-H1 mRNA expression levels in CBM with lymph nodes metastases were lower than those in CBM without metastases (P < 0.05), while no significance of nm23-H2 mRNA expression levels was found between CBM with and CBM without metastasis (P > 0.05). The results were comparative to those of Northern blotting of the same cases. The authors concluded that, as also in the study of Northern blotting, the expression of nm23-H1 mRNA significantly correlated inversely with lymph node metastasis in CBM, while the expression of nm23-H2 mRNA not. Q-RT-PCR was a useful method to detect the mRNA levels of nm23 gene in buccal carcinoma.

Antigens, Neoplasm↗
PubMed1997

[The structure correction of villosolside].

The crystal structure of villosolside was determined by X-ray diffraction, which led to some stereochemical amendment of the structure proposed in the article by Xu CJ et al. in Acta Pharm Sin 1985, 20:652.

Crystallography, X-Ray↗
PubMed1997

[Determination of adenosine and thymidine in Fritillaria bulbs by dual wavelength ultraviolet spectrophotometry].

A convenient method for the quantitative analysis of adenosine and thymidine in Fritillaria bulbs was developed by means of dual wavelength ultraviolet spectrophotometry. This method has good linear relationship and the interrelated coefficient of standard curve for adenosine and thymidine were all found to be 0.9999. The methanol extracts of four species of Fritillaria have been analyzed with this method. The results show that the the bulbs of four species contain different quantities of adenosine and thymidine, which indicates that the nucleosides may be responsible for the anti-coagulation activity of Fritillaria.

Adenosine↗
PubMed1997

[The antibechic, expectorant and antiasthmatic actions of Cynanchum komarovii].

The water and ethanol extracts of Lao Gua Tou (Cynanchum komarovii) is effective on relieving cough caused by the irritation of ammonnia water in mice. The extract can increase the secretion of repiratory tract and promote expectoration, also alleviate asthma induced by histamine and acetylcholing chloride in guinea pigs.

Animals↗