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Biomedical subjects

Y Tian

Publications and source records attributed to Y Tian.

At least 199 records · Page 11Linked to original sources
PubMed1995

Two classes of structurally different antagonists display similar species preference for the human tachykinin neurokinin3 receptor.

Two classes of structurally different tachykinin neurokinin3 (NK3) antagonists were used to evaluate species difference in antagonist binding between human and rat NK3 receptors. In competition binding experiments with [125I-MePhe7]NKB as radioligand, PD 154740, PD 157672, SR 48968, and SR 142801 displayed lower Ki values for the human NK3 receptor (40 +/- 4, 12 +/- 1,350 +/- 50, and 0.40 +/- 0.05 nM, respectively) than for the rat NK3 receptor (2450 +/- 130, 288 +/- 25, > 10,000, and 11.0 +/- 0.5 nM, respectively). Data from in vitro functional assay showed similar species preference as observed with the competition binding assay. It was shown previously that substitution of only two amino acid residues in the rat receptor to their human counterparts could change the species selectivity of SR 48968, a weak NK3 antagonist. In the double-substituted rat mutant, all three antagonists (PD 154740, PD 157672, and SR 142801) displayed Ki values (76 +/- 8, 16 +/- 2, and 0.50 +/- 0.05 nM, respectively) very similar to the Ki values for the wild-type human NK3 receptor. Thus, in addition to their previously reported effects on SR 48968, these two amino acid residues are responsible for the species selectivity of these three additional NK3 antagonists. Because PD 154740 and PD 157672 are very different structurally from SR 48968 and SR 142801, our results indicate that the two identified residues may be involved in adopting a receptor conformation that favors the binding of NK3 antagonists that display species preference for the human NK3 receptor.

Animals↗
PubMed1995

[Induced expression of whiG, a gene crucial for sporulation of Streptomyces coelicolor].

whiG gene has been subcloned into Streptomyces expression vector pAK203 containing inducible promoter tipA. The expression of whiG gene promoted the spore formation of S. coelicolor J1501 and recovered the sporulation ability of whiG-deficient S. coelicolor C71. Increased amount of whiG gene product was detected by Western blot hybridization after induction of thiostrepton. It will be helpful for the future study of in vitro transcription of whiG-dependent promoters.

Gene Expression Regulation, Bacterial↗
PubMed1995

Dissecting protein:protein interactions between transcription factors with an RNA aptamer.

Nucleic acid aptamers isolated from random sequence pools have generally proven useful at inhibiting the interactions of nucleic acid binding proteins with their cognate nucleic acids. In order to develop reagents that could also be used to study protein:protein interactions, we have used in vitro selection to search for RNA aptamers that could interact with the transactivating protein Tax from human T-cell leukemia virus. Tax does not normally bind to nucleic acids, but instead stimulates transcription by interacting with a variety of cellular transcription factors, including the cyclic AMP-response element binding protein (CREB), NF-kappa B, and the serum response factor (SRF). Starting from a pool of greater than 10(13) different RNAs with a core of 120 random sequence positions, RNAs were selected for their ability to be co-retained on nitrocellulose filters with Tax. After five cycles of selection and amplification, a single nucleic acid species remained. This aptamer was found to bind Tax with high affinity and specificity, and could disrupt complex formation between Tax and NF-kappa B, but not with SRF. The differential effects of our aptamer probe on protein:protein interactions suggest a model for how the transcription factor binding sites on the surface of the Tax protein are organized. This model is consistent with data from a variety of other studies.

Base Sequence↗
PubMed1995

[Surgical treatment of chronic pancreatitis and evaluation of therapeutic efficiency].

Twenty-eight patients with chronic pancreatitis (CP) were treated surgically in our department from 1987 to 1994. According to imaging features of B-us, CT, ERCP and operative pancreatogram, CPs were classified into five imaging types: mass type (11 cases), mass with dilated bile duct type (8), diffusely swelling type (4), dilated bile and pancreatic duct type (3), dilated pancreatic duct type (2). The surgical procedure was determined by considering both of the imaging type and major symptoms. The patients with pancreatic mass were treated mainly with pancreatic resection, whereas the patients with dilated bile or/and pancreatic duct were treated with bile or/and pancreatic ductal drainage procedures. Sphincteroplasty, neurectomy, lithotomy and T tube drainage were combined with above mentioned procedures according to intraoperative findings. One patient died of acute cholangitis and hepatic failure, 19 patients were free of pain postoperatively. There was no obvious deterioration of pancreatic function. These data suggest that pathologic changes of CP can be shown by imaging techniques. On the basis of imaging features and major symptoms, choice of appropriate procedure or combination of various operations will improve therapeutic efficiency of CP.

Adult↗
PubMed1995

[Over-expression of glutathione S-transferase in Streptomyces].

mRNA was isolated and purified from human liver, and it was also used as templet for cDNA synthesis under the existence of reverse transcriptase. Two primers were designed and synthesized according to GST gene sequence which has been reported, GST gene was obtained using cDNA as templet and PCR technique. The sequencing result indicated that the GST gene is reliable, it was subcloned into NdeI and Bg1 II sites of plasmid pIJ6021, and then introduced into Streptomyces lividans TK54. Proteins were isolated from transformants (TK54/pIJ4486 and TK54/pIJ6021) respectively, SDS-PAGE result showed that the GST over-expressed and its yield is about 15% in soluble proteins in Streptomyces.

Glutathione Transferase↗
PubMed1995

[Experimental study on effect of sanchaning in treating primary trigeminal neuralgia].

Sanchaning is an empirial prescription in treating primary trigeminal neuralgia (PTN). Pills of this prescription have been applied to animal models in an experimental study and their effects were compared with that of distilled water as well as carbamazepine, a common Western medicine for curing PTN. The indexes, including the attack number of PTN of the model animals, the duration of the spontaneous reaction and the positive time of the induced response, showed that Sanchaning differed significantly from distilled water in treating PTN (P < 0.01), but slightly differed from that of carbamazepine (P < 0.05). The sequential trial has identified that Sanchaning could be used effectively to inhibit PTN and has the same effect as carbamazepine. But further study should be carried out to investigate the mechanism of its function in relieving PTN.

Animals↗
PubMed1995

[Value of dobutamine technetium-99m-MIBI SPECT in detecting coronary artery disease].

The value of dobutamine 99mTc-MIBI SPECT (Dobu-ECT) for detecting coronary artery disease (CAD) was assessed in 39 patients. Compared with coronary angiography, the overall sensitivity and specificity of Dobu-ECT for detecting CAD were 92.9% and 90.9%. Of 13 patients with CAD without myocardial infarction, the sensitivity of Dobu-ECT was 84.6%. In detecting CAD with single, double or triple vessel diseases, the sensitivity of Dobu-ECT was 90.9%, 87.5% and 100% respectively. Furthermore, 88.2% of the patients (15/17) with multivessel (two or three vessels) diseases were correctly identified as having multivessel involvement. For detecting CAD, the sensitivity and specificity of dobutamine ECG were 53.5% and 82%. No serious side effects were observed in the study. The results showed that Dobu-ECT is a feasibie, safe and noninvasive method for diagnosing CAD.

Adult↗
PubMed1995

Cloning of a gene encoding the precursor of nisin by PCR.

The structural gene for the precursor of nisin was synthesized by polymerase chain reaction and then cloned in pUC18. The nucleotide sequence of the cloned precursor nisin gene was determined by dideoxy termination method. The sequence data obtained agreed with those of precursor nisin genes isolated by other workers from different Lactococcus lactis strains.

Amino Acid Sequence↗
PubMed1995

[Relationship between the fetal axis and dystocia in cephalic presenting deliveries].

OBJECTIVE: To study the relationship between the fetal axis and dystocia in cephalic presenting deliveries. METHODS: The fetal axis of the observed cases in their late pregnancy were measured by the method which was designed by anatomical projection. During labor the cases with abnormal fetal axis were divided randomly into control group and study group. The abnormal fetal axis in the study group was corrected by hand. RESULTS: The abnormal fetal axis existed in 108 of 512 (21.1%) cases in late pregnancy and were divided into different degrees. The rate of severe degree was 51.8%. During labor 88 of 483 (18.2%) cases were severe degree. They were sub-divided into control group (30 cases) and study group (58 cases). The results showed: in the study group the descent of fetal-presentation was accelerated, the stage of labor became shorter, the incidence of persistent occipito-posterior or occipito-transverse position and operative delivery were decreased, and the postpartum hemorrhage out down also. CONCLUSIONS: The abnormality of fetal axis exists and it can affect the progress of labor. The abnormal fetal axis should be diagnosed and corrected in time. To some extent, it can reduce the mother's physical consumption in labor and decrease the incidence of dystocia.

Delivery, Obstetric↗
PubMed1994

Dopamine and gamma-aminobutyric acid transporters: differential regulation by agents that promote phosphorylation.

Treatment of striatal synaptosomes with the protein phosphatase inhibitor okadaic acid significantly decreased gamma-aminobutyric acid (GABA) uptake, indicating that the GABA transporter may be regulated by phosphorylation. Forskolin and 8-bromoadenosine-3,5-cyclic monophosphate (8-br-cAMP) inhibited GABA uptake to the same extent as okadaic acid, suggesting the involvement of protein kinase A in GABA transporter regulation. In contrast, the same treatments did not alter dopamine (DA) uptake into striatal synaptosomal preparations. The results suggest that the structurally related GABA and DA transporters may be subject to different post-translational regulation.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1994

Effect of type of resection on plasma granulocyte elastase levels following surgery for non-small cell lung carcinoma.

The lung is the primary focus of complications associated with adult respiratory distress syndrome (ARDS) and increased activation of granulocytes has been implicated in the genesis of ARDS. In the present study, plasma granulocyte elastase levels were measured in 24 patients undergoing lung resection for non-small cell lung carcinoma. Pre-, peri- and post-operative assessments of plasma elastase levels were made of patients who underwent a partial resection (lobectomy, n = 13) and patients who underwent a complete lung resection (pneumonectomy, n = 11). Preoperatively, values were similar for both patient cohorts and did not differ from those of normal volunteers. However, immediately (1 h) post-operation, elastase levels in patients who had undergone pneumonectomy were significantly elevated (300% of baseline value, P < 0.005), whereas levels were unchanged in lobectomy patients. On the 1st post-operative day (POD), elastase levels had returned to normal in pneumonectomy patients, whilst lobectomy patients now exhibited increased plasma elastase levels which remained marginally increased until the time of discharge (P < 0.05). The determinants of granulocyte activation following lung resection remain to be elucidated but may potentially relate to ischemic reperfusion in patients undergoing lobectomy, or alternatively may simply reflect the extent of manipulation, compression and contusion of lung tissue.

Aged↗
PubMed1994

Molecular biology of rotaviruses. IX. Conservation and divergence in genome segment 5.

Nucleotide sequencing of RNA segment 5 from seven strains of group A rotavirus has been carried out to investigate the extent of diversity and conservation, as well as possible selective pressures involved in driving the fixation of sequence changes in this gene. Analyses of the derived sequences revealed that sequence conservation could not be correlated either with rotavirus serotype or the species of origin of the virus strain. These sequences together with other published and unpublished sequences of this gene have raised the total number available for comparison to 17. Alignment of all the available sequences revealed that only 88 amino acid positions (17.6%) in the protein encoded by gene 5 (VP5) are absolutely conserved but that the metal-binding motif reported by others is conserved in all sequences. Despite the high degree of sequence divergence, alignment of secondary structure predictions for VP5 showed a high level of conservation, suggesting that constraints on sequence divergence may operate at the level of overall higher-order structure of the encoded protein.

Amino Acid Sequence↗
PubMed1994

[Cloning of T7 lysozyme gene and construction of the vector for transgenic plants resistant to bacterial infection].

DNA were extracted from bacteriophage T7 and digested partially with Ava II. T7 lysozyme gene was obtained by PCR. DNA sequence analysis showed that the nucleotide sequence of T7 lysozyme gene was 99.5% homologous with the reported sequence and its deduced amino acid sequence was the same as reported. DNA fragment encoding the signal peptide of the pathogenesis-related protein 1b(PR-1b) from tobacco and cecropin (Shiva-I) gene cloned in pUC19 were modified by PCR. The PR-1b signal peptide gene was fused respectively to the 5' terminals of T7 lysozyme gene and expression vector, so that T7 lysozyme gene and Shiva-I gene could express simultaneously in transgenic plants and the two gene products could be secreted to extracellular space.

Amino Acid Sequence↗
PubMed1994

Cloning of polygalacturonase (PG) cDNA and inhibition effects of its antisense RNA on the expression of PG gene in transgenic tomato plants.

We have amplified a 1.5-kb PG cDNA including its complete open reading frame, using two primers specific to PG gene and PCR technique. Its fidelity and correctness were confirmed by restriction mapping and partial DNA sequencing. The PG gene was then inserted into a binary vector, pBin437, in an inverted orientation between the 35S promoter with duplicated enhancers and the Nos3' transcriptional termination sequence, and the resulting plasmid pBPG was introduced into LBA 4404. The A. tumefaciens harboring pBPG was used to transform tomato plants. Sixty kanamycin-resistant transformants were selected. PCR detection showed two-third of the transformed plants tested (30 plants) contain the exogenous PG gene. The PG activity assay and SDS-PAGE analysis of proteins from ripening fruit cell wall showed that the PG activity in transgenic tomato plants were inhibited in different extent. One of them, plant 3, gave only 7% PG activity compared with the control (100%). These results suggest that the expression of the anti-PG gene has effectively inhibited the expression of endogenous PG gene. The effect of low-level PG activity on tomato fruit ripening and storage is being investigated.

Base Sequence↗
PubMed1994

[Determination of total arsenic in food by borohydride reduction colorimetric method].

A method for determination of total arsenic in food by borohydride reduction colorimetry is presented. After samples' digestion, the arsenic is converted into trivalent arsenic by KI-thiourea under heating when the solution's acidity is more than 1.0mol/L. Trivalent arsenic is then reduced by sodium borohydride to arsine gas which can react with AgNO3 in absorbing solution to form a yellow substance whose maximum absorption wavelength is 400nm. The method was applied to the determination of total arsenic in grape wine, carp, dried shrimp, rice powder and lettuce, and the variation coefficients were 13.3%, 12.8%, 8.2%, 12.2% and 7.2%, respectively. The recoveries from dried shrimp, carp and rice powder were 98.0%-112.0%, 82.0%-98.8%, and 84.2%-115.0%, respectively. The method was also applied to the determination of arsenic in reference material rice powder NBS 1568 and the result, 0.37-0.43mg/kg, coincided with the given value 0.41 +/- 0.05mg/kg.

Animals↗