Biomedical subjects

Jun Liu

Publications and source records attributed to Jun Liu.

At least 253 records · Page 14Linked to original sources

PubMed2004

[Construction of tyrosine hydroxylase gene modified mesencephalic astrocytes].

OBJECTIVE: To construct tyrosine hydroxylase(TH) gene expressing mesencephalic astrocytes for the experiment of gene therapy for Parkinson's disease (PD). METHODS: The recombinant retroviral vector pN2ATH was constructed and transferred into PA317 pakaging cells by electroporation method. Resistant clones were obtained with G418 selective culture, and the virus supernatants were harvested. The mesencephalic astrocytes were cultured with the pN2ATH viral supernants. After 7-9 days culture, TH expression in the infected astrocytes were detected by immunohistochemistry. RESULTS: After G418 selection, high titer PA317/pN2ATH cells were obtained. The mesencephalic astrocytes transfected with pN2ATH succesfully expressed TH. CONCLUSION: Mesencephalic astrocytes transfected with pN2ATH can efficently express TH,which may provide a basis for further studies on gene therapy of PD in animals.

Animals↗

PubMed2004

[Clinical investigation of application of lung biopsy in the diagnosis of diffuse pulmonary interstitial disease].

OBJECTIVE: To evaluate the application of lung biopsy in the diagnosis of diffuse pulmonary interstitial disease (DPID). METHODS: The data of lung biopsy from 17 cases with uncertain DPID obtained during the period of July 1997 and December 2002 were retrospectively analysed. RESULTS: All the cases were diagnosed by pathology. Three of them were diagnosed as sarcoidosis. Two were pulmonary alveolar proteinosis. One with usual interstitial pneumonia (UIP), one with bronchiolitis obliterans and organizing pneumonia, one with nonspecific pneumonia, one with Castleman's disease, one with pulmonary lymph angio-leiomyomatosis, two with bronchioalveolar carcinoma, one as rheumatoid pulmonary fibrosis complicated with pulmonary squamous cancer and locally metastasis in lungs, two as pulmonary lymphangitic carcinomatosis, one as lung squamous cancer with pulmonary lymphangitic metastasis, and one with primary pulmonary paraganglioma. CONCLUSION: Harvest of lung tissue directly by biopsy could be the most useful diagnostic method for DPID, and it is a highly valuable diagnostic tool for those patients whose diagnosis is uncertain with routine chest film and high resolution computed tomography.

Adult↗

PubMed2004

[Changes of polyamines level in Glycine soja and Glycine max seedlings under NaCl stress].

With internationally common-used Glycine max (the salt-tolerant Lee68) and Glycine soja (the salt-sensitive N23232) as reference, this paper studied the polyamines (PAs) contents and polyamine oxidase (PAO) activities in the highly salt-tolerant BB52 (Glycine soja) seedlings, which showed that under 150mmol x L(-1) NaCl stress for 2d, the decrease of Put and Spd contents was more significant, but that of Spd content was less significant in roots of BB52 than in those of Lee68 and N23232. For leaves, the decrease of Put and increase of Spd contents were markedly observed in BB52. The ascent of (Spm + Spd)/Put ratios and descent of Put/PAs ratios showed a positive relation to their salt tolerance. The PAO activity in roots and leaves was all increased, and most obvious in N23232. The relationship between PAs levels in BB52 and its salt tolerance was also discussed.

Oxidoreductases Acting on CH-NH Group Donors↗

PubMed2004

[Cloning of potato invertase inhibitor St-inh cDNA and its expression in E. coli and functional analysis].

A full length cDNA clone encoding invertase inhibitor was isolated by RT-PCR combined with 5' RACE from potato (S. tuberosum) tubers of cv. JH and designated as St-inh. The encoding region of St-inh is of 663bp encoding a protein of 221 amino acids. The DNA fragment including St-inh cDNA was cloned into the vector pET28a (+) and expressed successfully in E. coli. Co-incubation of the proteins produced by St-inh in E. coli and the invertase extracts from potato tubers of cv. E1, JH and tomato fruits showed that the invertase activities of potato tubers and tomato fruits decreased by 34.3%, 21% and 33.8% respectively. These results indicated that products of St-INH protein had a function of invertase inhibitors. The analysises of the nucleotide and amino acid sequences using BLAST and T-COFFEE demonstrated that St-inh cDNA was of over 95% homologous to Kunitz-type C and there was a typical domain of Kunitz-type protein [L, I, V, M]-X-D-X-[E, D, N, T, Y-[D, G]-[R, K, H, D, E, N, Q]-X-[L, I, V, M]-X(5)-Y-X-[L, I, V, M. Therefore, it was conjectured that St-inh could be a member of Kunitz-type gene family.

Amino Acid Sequence↗

PubMed2004

ZNF268, a novel kruppel-like zinc finger protein, is implicated in early human liver development.

The advancement in gene knockout and transgenesis have brought about enormous improvement in our understanding of mouse embryogenesis in the past decade or so. On the other hand, relatively little is known about human embryogenesis due largely to the lack of easy access to human embryos and tissues for biomedical studies. We have previously isolated a novel zinc finger gene, ZNF268, from a 3-week-old human embryo cDNA library in an effort to identify genes important for human embryonic development. To investigate the potential involvement of ZNF268 in human embryogenesis, we report here the spatial and temporal regulation of its expression during development. Northern blot and Western blot analyses revealed that ZNF268 is expressed in early embryos, predominantly, if not exclusively, in fetal liver with little detectable expression in other fetal organs. Interestingly, unlike most zinc finger proteins, ZNF268 protein was found to be localized mainly in the cytoplasm of embryonic hepatocytes. This subcellular localization was substantiated by the localization of EGFP-ZNF268 fusion protein overexpressed in the transfected COS7 cells. These results suggest that ZNF268 plays a role in early human liver development most likely by functioning through a cytoplasmic mechanism.

Antibodies↗

PubMed2004

Relationship between AtPase activity and conjugated polyamines in mitochondrial membrane from wheat seedling roots under osmotic stress.

The effects of osmotic stress on the ATPase activity, the contents of -SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No. 18 (drought-tolerant) and cv. Yumai No. 9 (drought-sensitive)] roots were investigated. The results showed that ATPase activity and -SH group content decreased with polyethylene glycol(PEG) 6000(-0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine (NCC-Spd)/noncovalently conjugated putrescine(NCC-Put) and increase of the covalently conjugated putrescine (CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidine(Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, -SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No. 18 seedlings with methylglyoxyl bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase(SAMDC), and phenanthrolin (o-Phen), an inhibitor of transglutaminase(TGase), caused a significant decrease of the ratio of NCC-Spd/NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, -SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of -SH group, NCC-Spd and CC-Put in mitochondrial membrane.

Adenosine Triphosphatases↗

PubMed2004

[The relations between polyamine types and forms and polyamine oxidase activities in barley seedlings under salt stress].

The three polyamines (Put, Spd and Spm) and their different forms (free, perchioric acid soluble and insoluble conjugated) together with polyamine oxidase (PAO) activities were measured in barley (Hordeum vulgare L. KP7) seedlings under salt stress. The results showed that the free polyamines were dominant forms among three polyamines, account about 2/3 total polyamines. All three polyamines decreased in roots and leaves after 8 d under NaCl 200 mmol/L stress. The free polyamine content decreased dramatically as well as soluble conjugated polyamine content, while the insoluble ones changed little. Different concentration salt stress increased markedly the ratios of (Spd+Spm)/Put and decreased significantly the total polyamine content in roots and leaves. PAO activities in roots was increased at first and then decreased under NaCl stress, while in leaves the activities changed in opposite direction. It has been noted that the sum of free Spd and Spm (Spd+Spm) content is reversely correlated with PAO activity changes, which suggests that PAO might regulate the free polyamine content, therefore, the contents of the soluble and insoluble conjugated polyamines were affected.

Biogenic Polyamines↗

PubMed2004

[Induction of chilling tolerance and heat shock protein synthesis in rice seedlings by heat shock].

Heat shock applied to germinated rice seeds increased the chilling tolerance of seedlings. Comparison with the control, brief heat shock applied before chilling at 4 degrees C for 2 days and recovery at 25 degrees C for another 2 days decreased the permeability of cellular membranes and increased the content of proline in rice seedlings. Heat shock applied before chilling also increased the activities of superoxide dismutase, catalase, and peroxidase and the content of ascorbate in rice seedlings. In contrast, the lipoxygenase activity and the malondialdehyde content in the heat-shocked rice seedlings were lower than those in the control. Germinated rice embryos synthesized heat shock proteins of Mr 78, 70, 64, 46, 38, 24, 17 and 16 kD during heat shock. The results of Western blot suggested that the binding protein (Bip) of HSP70 play an important role in protecting the rice seedling against chilling damage.

Arabidopsis Proteins↗

PubMed2004

[Nitric oxide alleviates growth inhibition of maize seedlings under NaCl stress].

The effect of nitric oxide (NO) on growth of maize seedlings under 100 mmol/L NaCl stress was studied. The results showed that 0.1-200 mumol/L sodium nitroprusside (SNP), especially 100 mumol/L SNP, increased dry accumulation in maize seedlings significantly, the chlorophyll content, K(+)/Na(+) ratio and (Spd+Spm)/Put ratio, and decreased electrolyte leakage. These results suggest that NO may alleviate the damage caused by NaCl stress through increasing K(+) uptake and transport to shoots and decreasing Na(+) uptake and transport, and also through enhancing the conversing of Put to Spd and Spm.

Biogenic Polyamines↗

PubMed2004

[A prospective study of relationship between blood pressure and 10-year cardiovascular risk in a Chinese cohort aged 35-64 years].

OBJECTIVE: To provide epidemiological data for the revision of The National Guideline for Prevention and Treatment of Hypertension through the analysis of the association between blood pressure (BP) and the risk of cardiovascular diseases (CVD) in a cohort aged 35-64 years. METHODS: A prospective study was carried out in 11 provinces from 1992 to 2002. The association between BP and CVD (CHD and stroke) was analyzed in 31728 subjects aged 35 - 64 years. RESULTS: (1) Compared with BP < 110/75 mmHg, the risk of CVD increased 1 time (RR=2.09), 2 times (RR=3.23), and 10 times (RR=11.81) when BP was 120-129/80-84 mmHg, 140-149/90-94 mmHg, and > or = 180/110 mm Hg, respectively. (2) The risk of acute CHD for subjects with stage 2 hypertension was 2.3 times of those with optimal BP, whereas the risk of ischemic stroke and hemorrhagic stroke was 4.9 times and 11.7 times, respectively. (3) 36.1% of all CVDs, 44.0% of the acute stroke and 23.7% of the acute CHD were attributable to hypertension. (4) In each BP level, the 10-year risk of CVD increased with the increased number of other risk factors. CONCLUSIONS: The risk of CVD increases with BP continuously from BP of 110/75 mmHg. Therefore, the cutpoint of the diagnostic criteria for hypertension is arbitrary. Comprehensive intervention for multiple risk factor clustering should be strengthened to reduce the overall risk of CVD.

Adult↗

PubMed2004

[Fine needle aspiration cytology diagnosis of extramedullary leukemic infiltration].

OBJECTIVES: To assess the diagnostic accuracy of fine needle aspiration cytology (FNAC) in extramedullary leukemic infiltration. METHODS: The results of FNAC from 65 cases of extramedullary leukemic infiltration were reviewed and analyzed. RESULTS: In the 65 cases studied, there were 24 cases of acute lymphoblastic leukemia (ALL), 25 cases of acute myelogenous leukemia (AML), 6 cases of chronic lymphocytic leukemia (CLL) and 10 cases of chronic granulocytic leukemia (CML). The commonest site of infiltration was lymph node, which accounted for 73.8% of all cases. CONCLUSIONS: Accurate cytologic diagnosis of extramedullary leukemic infiltration relies on detailed morphologic assessment as well as correlation with clinical examination and other relevant laboratory findings, especially in patients whose initial symptom being a local mass. Leukemic infiltration, which represents proliferation of primitive cells, should be distinguished from non-Hodgkin's lymphoma. Morphologic assessment by oil immersion lens and examination of peripheral blood smears is useful in this respect.

Adolescent↗

PubMed2004

[A statistic analysis on absence of third molar germs in orthodontic patients].

OBJECTIVE: To examine the absence of the third molar germs in orthodontic patients and to evaluate the relationship between third molar germs and malocclusion. METHODS: The subjects comprised 234 patients (male 92, female 142) from the orthodontic clinic whose ages were 14-18. The assessments of the third molar germs were made from panoramic radiographs, and the assessments of ANB angle were made from lateral cephalograms. All the data were analyzed by statistic chi2 test. RESULTS: The percentage of male who missed one or more third molar gems (37.0%) was higher than that of female (24.6%). There was no significant difference between the absent frequencies of third molar germs on left and right sides in either maxilla or mandible. The absent percentage of third molar germs in skeletal III subjects was higher than those in both skeletal class I and II subjects. The absent difference of third molar germs was in upper arches (P < 0.05), but not in lower arches (P > 0.05). There was no significant difference in absent percentage of third molar germs between skeletal class I and II subjects. CONCLUSION: Male patients have higher absent frequencies of third molar germs than female ones. Skeletal class III patients have higher absence of third molar germs in upper jaws than skeletal class I and II patients.

Adolescent↗

PubMed2004

[Studies on influence of fungal elicitor on hairy root of Panax ginseng biosynthesis ginseng saponin and biomass].

OBJECTIVE: To study influence of fungal elicitors on the biomass and ginseng saponin biosynthesis of hairy roots of Panax ginseng (HRPG). METHOD: Fungal elicitors were extracted from Colletorichum lagnarinm, Phoma filtrate, Fusarium oxysponum, Asperillus niger and culture with HRPG. The total ginseng sponin and four kinds of monomeric sponins were analysed by UV-spectrophotometry and RP-HPLC. RESULT: Fungal elicitors coula not only can influence on HRPG biomass and total ginseng sponin, but also improve or decrease some monomeric sponin. The total ginseng sponin could be increased to 3.649% but Rg1 and Re could not be detected when A. niger elicitors wss 20 mg x L(-1) in the culture fluid. CONCLUSION: Fungal elicitor has specificity influence on secondary metabolite of HRPG. HRPG can biosynthesize specially active component by using specific fungal elicitor is used.

Aspergillus niger↗

PubMed2004

[Morphogenesis in formative process in vitro from Rehmannia glutinosa].

OBJECTIVE: To study the morphogenesis in formative process of tuberous root in vitro from Rehmannia glutinosa and compare the anatomical shape of tuberous root with nature term R. glutinosa. METHOD: Tuberous roots of different vegetal phase were cut and dyed, then made into paraffin cuts and observed microscope. RESULT AND CONCLUSION: In anatomical shape, nature R. glutinosa and tuberous root were the same, which showed that no structural variation occurred in tuberous root induced process.

Plant Roots↗

PubMed2004

[The relationship between the fragment deletion of mtDNA in old rat and the sensitivity to aminoglycoside antibiotic induced deafness].

OBJECTIVE: To analyze the relationship between the fragnent deletion of mitochondrial DNA (mtDNA) of inner ear in rats and aminoglycoside antibiotic induced deafness (AAID), and to investigate the possible role of mtDNA deletion in the sensitivity to aminoglycoside antibiotic induced deafness in old rat. METHOD: Thirty wistar rats were divided into group A (old rat, > 24 months, n = 15) and group B (young rat, 4 months, n = 15) according to the age. Kanamycin (KM) was intraperitoneally injected 500 mg/kg per day for 10 consecutive day in all rats. The threshold of the auditory brainstem response (ABR) was measured before and after the drug administrations. The inner ear tissue was harvested and the mtDNA was amplified to identify the 4834 bp deletion by PCR technique. RESULT: The elevation of the mean ABR thresholds in group A (42.08 +/- 8.19) dB peSPL was significantly higher than that in group B (12.71 +/- 4.42) dB peSPL (P < 0.01). In group A, 10 of the 15 rats demonstrate the mtDNA4834 deletion and the elevation of the mean ABR thresholds in the rats with mtDNA4834 deletion (45.00 +/- 7.67) dB peSPL was significantly higher than that without so deletion (33.33 +/- 4.08) dB peSPL (P < 0.01). However, mtDNA4834 deletion was negative in group B. CONCLUSION: Deletion of mtDNA of inner ear tissue in old rat is found. The mtDNA deletion may play an important role in the hypersensitivity to aminoglycoside antibiotic ototoxiciy in old rats.

Animals↗

PubMed2004

[Study on the identification of standard and false BanXia by two-dimensional infrared correlation spectroscopy].

Standard BanXia (Pinellia temata (Thumb.) Breit) and false Shui BanXia (Typhonium flagelliforme (Lodd.) Blume) were identified fast and nondestructively by Fourier Transform Infrared Spectroscopy (FTIR) combined with two-dimensional correlation spectroscopy (2D) in this paper. The two kinds of BanXia wree similar to each other in one-dimensional IR spectra but quite different in 2D FTIR spectra. In the range between 1 220 cm(-1) and 1700 cm(-1), one strong autopeak was aroused by BanXia around 1410 cm(-1) in synchronous spectrum, whereas three autopeaks not only at 1460 cm(-1) but also at 1540 cm(-1) and 1680 cm(-1) aroused by Shui BanXia. Also in the range between 940 cm(-1) and 1220 cm(-1), three autopeaks were shown at 980, 1080 and 1150 cm(-1) in synchronous spectrum of BanXia, but only two autopeaks at 1080 and 1150 cm(-1) in synchronous spectrum of Shui BanXia. It is proved that the 2D FTIR could serve in distinguishing standard and false medicinal herbs due to its unique advantages such as enhanced resolution and increased identification ability. Therefore, the rapidity and accuracy of 2D FTIR spectroscopy make it a powerful and new approach to evaluating the medicinal herbs.

Binding Sites↗

PubMed2004

[Protective roles of vitamin E and coenzyme Q10 in the inner ear mitochondrial DNA 4834 bp deletion mutation of rats].

OBJECTIVE: To explore the protective roles of vitamin E and coenzyme Q10 in the inner ear mitochondrial DNA 4834 bp deletion mutation of rats. METHODS: Forty-six Wistar rats were randomly divided into three groups. The rats of group A (18 rats) had admitted adriamycin 1 mg/kg by intraperitoneal injection twice a week and had taken vitamin E 50 mg/kg, coenzyme Q10 10 mg/kg orally everyday for three months. Group B (18 rats) was given the same dose of adriamycin as group A and saline instead of vitamin E and coenzyme Q10. Group C (10 rats) was given Saline only. The inner ear tissue was harvested and mitochondrial DNA was amplified to identify t he 4834 bp deletion mutation by nested-primer polymerase chain reaction (nested-PCR) technique. And the serum glutathione peroxidase (GSH-PX) activity was measured. RESULTS: The incidence of mitochondrial DNA 4834 bp deletion mutation of group A was 23.08% (3/13), group B was 68.75% (11/16), and group C was 0 (0/8). The mutation incidence of group A was significantly lower than group B (Fisher's exact test, 1-sided, P = 0.018) and there was no significant difference between group A and group C (Fisher's exact test, 1-sided, P = 0.215). The activity of serum glutathione peroxidase of group A was marked higher than that of group B (adjusted t' test, 1-sided, t' = 6.474, P < 0.01). And the difference of activity of serum glutathione peroxidase between group A and group C was not significantly (adjusted t' test, 2-sided, t' = 1.920, P > 0.05). CONCLUSION: The results suggested that vitamin E and coenzyme Q10 could improve the ability of free radicals cleaning and protect the mitochondrial DNA from 4834 bp deletion mutation.

Animals↗

PubMed2004

[Stochastic resonance in weak signal detection by sensory systems].

OBJECTIVE: To study the stochastic resonance phenomenon in biological sensory systems through signal detection theories and psychophysical experiments. METHOD: Sensory system is considered as threshold detectors including the receiver part and the classifier part. Compared with conventional models regarding the receiver part of the sensory system as a linear or single non-linear system, a summing network constructed by MacCulloch-Pitts neurons was provided in our model to simulate the receiver part. RESULT: The simulation results showed that the relevant indices of the percent correct measure and the detectability of signal both exhibit stochastic resonance behaviors. Psychophysical experiments were carried out through both 1IFC (one interval forced choice) and 2IFC (two interval alternative forced choice) methods. The experimental results qualitatively verified the considerations in accordance with the theoretical model. CONCLUSION: This work gives a proof that stochastic resonance is not only an epiphenomenon in sensory systems.

Models, Neurological↗