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Q X Liu

Publications and source records attributed to Q X Liu.

15 recordsLinked to original sources
PubMed2001

Saikosaponin v-1 from roots of Bupleurum chinense DC.

Three triterpenoidal saponins, saikosaponin v-1(1), 6"-O-acetyl-saikosaponin b2 (2) and 6"-O-acetyl-saikosaponin d(3) were isolated from the roots of the title plant and the structures were identified on the basis of spectral analysis. Saikosaponin v-1 is a new compound, which was identified as 3beta,16alpha,23,28-tetrahydroxy-olean-11,13(18)-dien-30-oic acid-3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-fucopyranosyl-30-O-xylitol ester.

Adjuvants, Immunologic↗
PubMed2000

MBF2 is a tissue- and stage-specific coactivator that Is regulated at the step of nuclear transport in the silkworm Bombyx mori.

Coactivators MBF1 and MBF2 mediate BmFTZ-F1-dependent transcriptional activation in vitro by interconnecting BmFTZ-F1, TATA binding protein TBP, and TFIIA. Here, we analyzed temporal and spatial expression patterns of MBF2 during embryonic and larval development of the silkworm Bombyx mori. MBF2 was detected in unfertilized eggs and embryos until stage 26. In stage 22 embryos, MBF1, MBF2, and BmFTZ-F1 colocalize in neural cells. During the larval stage, MBF2 was not expressed in the fat body and trachea. In the silk gland, MBF2 mRNA was constitutively expressed, but MBF2 protein appeared in the period between the second day and the molting D3 stage in both the third and the fourth instars and then disappeared. MBF2 was also detected on the second and third days of the fifth instar. Immunostaining during the fourth molt showed that MBF1, MBF2, and BmFTZ-F1 localize in the nucleus only at the D3 stage, while the two cofactors are present in the cytoplasm at other stages. Immunoprecipitation experiments suggested that MBF1, MBF2, and BmFTZ-F1 form a complex at the D3 stage. Transient expression of these factors in Schneider cell line 2 revealed that MBF1 and MBF2 localize to the nucleus and enhance BmFTZ-F1-dependent transcription only when all three factors are present. These data illustrate the functional regulation of MBF1 and MBF2 at the step of nuclear transport and implicate MBF2 in tissue- and stage-specific transcription.

Animals↗
PubMed2000

[Studies on the chemical constituents from Sophora flavescens ait].

OBJECTIVE: To study the constituents from Sophora flavescens. METHODS: Separating the constituents by means of chromatography and identifying their structures on the basis of spectral analysis. RESULTS: The five compounds obtained were identified as sucrose, lignoceric acid, beta-sitosterol, sinapic acid hexadecyl ester and umbelliferon. CONCLUSION: Sinapic acid hexadecyl ester is a new compound. These compounds were obtained from the plant for the first time.

Coumaric Acids↗
PubMed1998

Comparison of sequences of a transcriptional coactivator MBF2 from three Lepidopteran species Bombyx mori, Bombyx mandarina and Samia cynthia.

MBF2 was first isolated from the silkworm Bombyx mori as a positive cofactor that activates transcription through its interaction with TFIIA. To identify conserved domain(s) within the MBF2 molecule, we isolated cDNAs encoding MBF2 homologues from other silkworms Bombyx mandarina and Samia cynthia. Bacterially expressed and purified MBF2 of B. mandarina and S. cynthia activated transcription in vitro. The predicted amino acid sequences of MBF2 from two Bombyx species share 97% homology. When we compared between B. mori and S. cynthia factors, the homology reduced to 50%. Four regions in MBF2 are conserved among these three species. Two of them are present in the middle region of MBF2 that is essential for the transcriptional activation.

Amino Acid Sequence↗
PubMed1998

Voltage-dependent, open channel blockade of the cardiac sarcoplasmic reticulum potassium channel by 4-aminopyridine.

The nature of open state block was characterized in isolated canine cardiac sarcoplasmic reticulum (SR) potassium channel incorporated into planar lipid bilayers. 4-Aminopyridine (4-AP) blocked the open conductance state of the potassium channels in a voltage-dependent manner. Blockade was reversible, occurred from either the cis (cytoplasmic) or the trans (lumenal) side and was competitive with potassium ions. Reversal potential measurements indicated that this channel was impermeable to 4-AP. Measured effective electrical distances were roughly symmetrical and indicated penetration of 0.39 and 0.42 of the membrane electrical field from the cis and trans sides, respectively. Effective electrical distance was insensitive to potassium ion concentration in the range 50 to 200 mM and indicated that 4-AP was able to penetrate relatively deeply into the pore compared with blockade of sarcolemmal potassium channels. Potassium ion concentration and voltage dependence of 4-AP blockade were consistent with a two binding site blockade model, similar to the model used previously to describe calcium ion blockade of the SR potassium ion channel. Unlike calcium blockade, however, 4-AP blocked from either cis or trans in a similar manner, suggesting a distinct binding site for each of these two blockers. Open channel, voltage-dependent blockade of the SR potassium channel by 4-AP is in marked contrast to its action on sarcolemmal potassium channels and suggests that either 4-AP penetrates much farther into the potassium channel permeation pathway than was previously believed, or the SR potassium channel has a very different physical pore arrangement from that of sarcolemmal potassium channels.

4-Aminopyridine↗
PubMed1993

[Long-term surveillance after basic elimination of bancroftian filariasis].

The longitudinal and cross-sectional systemic surveillance have been conducted for 9-11 consecutive years in six counties (cities) of Guangxi Zhuang Autonomous Region after basic elimination of bancroftian filariasis. The two different control regimens had been used with DEC selective treatment followed by mass treatment of all persons and selective treatment followed by taking DEC medicated salt. During the former 6 years, residual microfilaremia cases could still be detected; whereas during the latter 5 years, no microfilaremia cases could be detected at all. The natural infection of vector mosquitoes showed negative. The positive rate of antibody in the populations was reduced to 1.4-5.5% detected by IFAT, reaching to the level of local non-endemic areas. The result indicated that the transmission of filariasis in these areas has been blocked. The authors suggested that a period of 10 years might be appropriate for surveillance after basic elimination of bancroftian filariasis.

Animals↗
PubMed1991

Treatment of bilateral intrahepatic stones with high duct strictures through selective central hepatic resection.

Bilateral intrahepatic duct stones with strictures, more common in the Orient than elsewhere, are difficult to access surgically. The results of surgical procedures have not been generally successful and are attended by a high postoperative complication and recurrence rate. We report the treatment of 30 patients with intrahepatic calculi and high duct strictures by means of selective central hepatic resection without dissection of the major vessels at the hilum. Central hepatic resection provided satisfactory access to the primary and secondary confluences of the intrahepatic ducts, allowed removal of residual stones and ascariasis, and permitted correction of multiple strictures. Twenty-nine patients so treated were followed for a mean of 32 months after operation. No patients developed recurrent fever, biliary colic, or jaundice after the operation. The technique is therefore recommended as an effective alternative to extensive hepatic lobectomy in the treatment of the intrahepatic calculi with multiple strictures.

Adult↗
PubMed1990

Selenium supplementation increases renal glomerular filtration rate.

Selenium (Se) is a trace element variously distributed in the human body and especially concentrated in certain organs, such as the renal cortex. We report results obtained during a ten weeks' oral Se supplementation. Experiments were devised to evaluate previous preliminary observations which suggested a possible effect of Se addition on the renal glomerular filtration rate. Eleven healthy volunteers have given increasing oral Se (as a sodium selenite solution) as follows: on the first week they have given 100 micrograms Se per day; this was progressively increased 100 micrograms per day for each of the following 6 weeks; the last dose (700 micrograms per day) was maintained for three further weeks. Serum and 24-hour urine were collected weekly for creatinine determination by kinetic Jaffé reaction and Se measurement by proton-induced X ray emission (PIXE). The final mean serum creatinine concentration was 13% lower than the initial mean value (p less than 0.01). Mean creatinine clearance increased significantly (p less than 0.05) and showed a direct correlation with mean Se clearance (r = 0.79; p less than 0.001). As the increase of creatinine clearance was concomitant with a reduction of serum creatinine levels, we excluded the possibility of toxic effects. Our results seem to suggest a positive influence of Se supplementation on the rate of glomerular filtration and we hypothesize that Se might be involved in the vascular regulatory mechanism of the kidney.

Adult↗
PubMed1990

[Pathology of placenta from small for gestational age infants].

Pathologic study was carried out in 125 placentas, of which 25 were from cases of small for gestational age infants (SGA) and 100 from normal pregnancies. Ultrastructural study was done in 5 cases of each group. In the SGA group placenta circumvallata and velamentous insertion of cord were more frequently seen and the percentages of syncytial knots, cytotrophoblastic cells, and fibrinoid necrosis, stromal fibrosis and obliterative endarteritis of chorionic villi were also higher. Deficiency of vasculo-syncytial membranes and unduly thick trophoblastic basement membranes were common features of the SGA placentas. The most significant ultrastructural finding was the spasticity of capillaries of the villous stroma. It is believed that insufficient utero-placental blood flow may lead to the occurrence of SGA infants.

Chorionic Villi↗
PubMed1988

The changing patterns of occurrence and management in primary mediastinal tumors and cysts in the People's Republic of China.

Primary mediastinal tumors and cysts (MTC) constitute a common problem in thoracic operations done in the People's Republic of China. Data from 4,357 instances of MTC diagnosed in China between 1963 and 1985, including 307 from our own facility, are presented. Teratoid tumors are the most common of the MTC in the northern part of China contrasting with thymomas and neurogenic tumors which are the most common in the southern part of China; a finding that notes a significant difference (p less than 0.01). Beyond this, the distribution of MTC is different than in North America. In patients we studied, we were able to predict the correct histopathologic diagnosis 80 per cent of the time by considering the history of the patient and the results of a conventional roentgenogram of the chest. This was increased to 91.4 per cent when needle biopsy was added. Optimal therapy for MTC is complete surgical resection. We present a scheme for localization of the various types of MTC and an operative approach.

Adolescent↗
PubMed1985

[Histochemical changes in endometrial fibrolytic activity with different IUDs].

The histochemical changes of endometrial fibrinolytic activity were observed in rabbits. 1 horn of the uterus was put in IUDs made of different materials (steel, copper, magnet, and EACA-copper). It was found that the endometrial fibrinolytic activity in the experimental horns was significantly higher than the controls, and the effect was the highest with the copper IUD. In the contrasted groups (copper versus steel, copper versus magnet, steel versus magnet), the endometrial fibrinolytic activity induced by the copper IUD was the highest (P0.05), while there was no significant diffeence between that of steel and magnet (P0.05). In the EACA-copper IUD groups, the results were also observed on days 7, 14, and 28 after insertion of the devices. There was no difference in fibrinolytic activity between the experimental horns and the controls in 7 and 14 days groups, but it was significantly higher than the controls in 28 days group. In the contrasted groups of the EACA-copper IUD and copper IUD the endometrial fibrinolytic activity of the former was lower than that of the latter in 7 days group (0.05 P 0.1). This suggests that fibrinolytic activity may be inhibited by EACA, which, however, may be released from IUD at such a rapid rate that it loses its effect in 28 days.

Animals, Laboratory↗