Biomedical subjects

Jun Li

Publications and source records attributed to Jun Li.

At least 343 records · Page 19Linked to original sources

PubMed2005

[Chemical investingation of Chinese mangrove Sonneratia apetala II].

OBJECTIVE: Isolation and structural elucidation of the constituents of China mangrove Sonneratia apetala. METHOD: chromatography methods were used for isolation of compounds, spectroscopic methods were used for structural identifyication. RESULT: seven known compounds named (+/-) symgaresinol, betulinic acid, lupeol, lupeone, stigmast-5-ene-3beta, 7alpha-diol, beta-alpha myrin hexadecaneate, physcoion were isolated. CONCLUSION: these known compouns were unreported previously from this plant.

Magnoliopsida↗

PubMed2005

[Complete HBV DNA clone and sequence from serum samples of severe hepatitis B patients].

OBJECTIVE: To study the association between hepatitis B virus (HBV) mutants and the pathogenesis of severe hepatitis B by full-length HBV genome. METHODS: Serum samples from 10 severe hepatitis B patients were collected in our hospital. Serum HBV DNAs were extracted using DNA mini Kit, and amplified by LA Taq DNA polymerase to yield full-length HBV DNA. PCR products were isolated and cloned into vector pUCm-T, then transfected into DH-5 alpha cells. Positive clones were selected and checked by digestion, and full-length HBV DNAs were sequenced. RESULTS: 4 cases were cloned into vector pUCm-T successfully and completed the full-length sequencing. Among them, 3 cases had a G to A mutation at nucleotide 1896 in pre-C region and 1 had a double mutation of T1762-A1764 in the core promoter region. Some amino acid changes occurred within the known CTL, B or T cell epitopes of the PrS2 and C regions. CONCLUSIONS: This method could serve to study the relationship between HBV genome and the pathogenesis of severe hepatitis B.

Adult↗

PubMed2005

[The biotransformation of kaempferitrin by human intestinal flora].

AIM: To study the biotransformation of kaempferitrin, a major chemical principle of the fruits of Siraitia grosvenori (Swingle) C. Jeffery, with human intestinal flora. METHODS: The kaempferitrin was incubated with human intestinal flora. The biotransformation products were isolated and purified by chromatographic methods and the structures were determined by spectroscopic techniques. RESULTS: Kaempferitrin was converted into kaempferol 3-O-alpha-L-rhamnoside (afzelin, I) , kaempferol 7-O-alpha-L-rhamnoside (II), kaempferol (III) and p-hydroxybenzoic acid (IV) by human intestinal flora. rhamnoside (II), kaempferol (III) and p-hydroxybenzoic acid (IV) by human intestinal flora. CONCLUSION: The structure of kaempferitrin can be biotransformatedly converted by human intestinal flora.

Bacteria↗

PubMed2005

[Isolation and characterization of phenylethanoid glycosides from Clerodendron bungei].

AIM: To study the chemical constituents from Clerodendron bungei Steud. METHODS: The compounds were isolated and purified by various chromatographic techniques and identified by their physicochemical properties and spectral data. RESULTS: Ten phenylethanoid glycosides were isolated and identified as clerodendronoside (1), acteoside (2), isoacteoside (3), cistanoside C (4), jionoside C (5), leucosceptoside A (6), cistanoside D (7), campneoside I (8), campneoside II (9), cistanoside F (10). CONCLUSION: Compound 1 is a new phenylethanoid glycoside, while compounds 4-10 are obtained from this plant for the first time.

Catechols↗

PubMed2005

[Repair and reconstruction of oral and maxillofacial defect--clinical analysis of 1973 cases].

OBJECTIVE: To compare the reconstructive method of oral and maxillofacial defect with free tissue flaps. METHODS: The clinical materials were collected from 1 973 reconstructive cases between January 2000 and June 2004 and analyzed in terms of the distribution of age, gender, disease type, defect location, reconstructive method and the incidence of vascular crisis of free flaps as well as success rate of free flap respectively. SAS 6. 12 was adopted for statistical analysis. RESULTS: A total of 1973 reconstructive cases included 764 in middle age (>45 years to < or =60 years, 38.72%), 527 in old age (>60 years, 26.71%), 450 young adults (>28 years to < or =45 years, 22.81%), 187 in young age (>14 years to < or =28 years, 9.48%) and 45 children (< or =14 years, 2.28%). The ratio of male to female was 1.5 : 1. The ratio of benign to malignancy lesion was 1 : 1.94. The tongue defect accounted for 20.63%, followed by mandibular defect(17.38%), parotid defect(13.74%), buccal defect(12.72%), maxillary defect (8.16%), oral pharynx defect (7.60%), floor of mouth defect (5.68%) and others (14.09%). Vascular free flap transfers accounted for 45.82%(904), followed by axial flap(38.17%, 753), random flap (10.19%, 201), a vascularized bone graft (1.52%, 30) and others(4.30%, 85). The most frequently used flap was the forearm flap(594 cases), followed by the fibula free flap(143 cases) and the pedicled pectoralis major myocutaneous flap(369 cases); these three flaps accounted for 56.06% (1106/1973). In 47 free tissue flaps (5.20%) having vascular crisis, 30 were saved (63.83%). The success rate of total free tissue flaps was 98.19% (923/940). CONCLUSION: The majority of reconstructive cases of oral and maxillofacial defects is the middle aged and the old aged male patients with malignancy. The tongue defect accounts for about one fifth of all the cases. The vascularized free flap has a high success rate, so it is a main method for reconstruction of oral and maxillofacial defects. The forearm flap, the fibular free flap and the pedicled pectoralis major myocutaneous flap are the main management for repairing oral and maxillofacial defects.

Adolescent↗

PubMed2005

[Transpositional anastomosis of C7 posterior root and spinal accessory nerve to reconstruct the trapezius muscle function].

OBJECTIVE: To introduce a new approach of neurotization to treatment of the shoulder syndrome after the radical neck dissection by using transpositional anastomosis of C7 posterior root and the spinal accessory nerve to reconstruct the function of trapezius muscle. METHODS: From March 1999 to February 2001, 10 patients underwent the neurotization during the radical neck dissection. In the operation, the apo-cranial part of spinal accessory nerve was preserved from the trapezius muscle (> 3. 0 cm in length) and anastomosed to C7 posterior root. Objective physical examinations and electromyography were conducted before and after operation. One, 6 and 12 months after operation the trapezius muscle function after the transpositional anastomosis was evaluated. RESULTS: One, 6 and 12 months after operation, the recovery rates of each part were as follows: 9.8%, 68.9% and 73.5% in upper part; 4.7%, 73.6% and 69.4% in middle part; and 6.2%, 70.5% and 70.3% in lower part. The range of abduction motion of upper arm in 7 cases (70%) exceeded 90 degrees. The mean maximal abduction angle was more than 95 degrees. Evaluation of the shoulder function showed that myoatrophy was mild and the disability of abduction was classified as grade II in 7 cases and grade II in 3 cases. CONCLUSION: Transpositional anastomosis of the C7 posterior root to the spinal accessory nerve after radical neck dissection can well reconstruct the function of trapezius muscle. This approach provides a wide indication in comparison with the functional neck dissection without impairment of arm function after the cutting of C7.

Accessory Nerve↗

PubMed2005

[Studies on the changes of 5-hydroxymethyl furfuraldehyde content in Radix Rehmanniae steamed for different time].

OBJECTIVE: To find the changing regularity of 5-Hydroxymethyl furfuraldehyde (5-HMF) content in Radix Rehmanniae steamed for different time. METHOD: HPLC method was used, with C18 column (6 mm x 200 mm, 5 microm), a mixture of methanol-water (15: 85) as the mobile phase. The flow rate was 1.0 mL x min(-1). The UV detection was setat 284 nm and the column temperature was set at 24 degrees C. RESULT: The linear range was from 0.01 to 0.08 microg, r = 0.999 9 (n = 5). The average recovery was 100.2% and RSD was 2.7% (n = 5). CONCLUSION: The 5-HMF content increases as the processing time prolongs in a certain time rang.

Chromatography, High Pressure Liquid↗

PubMed2005

[Analysis of essential oil components by GC/FTIR and GC/MS].

The volatile components of clary sage (Salvia sclarea L.) oil were identified by gas chromatography-Fourier transform infrared spectroscopy (GC/FTIR) and gas chromatography-mass spectrometry (GC/MS). The application of GC/FTIR in analysis of essential oil was mainly discussed. The accuracy of qualitative analysis for essential oil was improved by such technique asthe reconstruction of different spectra regions Gram-Schmidt Fourier transforms infrared spectroscopy, and the application of subtracting of Fourier transforms infrared spectroscopy, and the mass spectrometry.

Chromatography, Gas↗

PubMed2005

[New study progress of sinomenine].

To further understand sinomenine, this paper has introduced the abstract technology, assaying, pharmaceutical chemistry, pharmacological action, pharmacotoxicology, pharmacokinetics and clinical application of sinomenine based on the important and significant contents of reference which have been consulted in the past ten years. Sinomenine is a kind of non-steroidal anti-inflammatory drugs with very effective and little side effect and expected it as a good new drug withdrawal medicine in the future.

Animals↗

PubMed2005

[Dihydroartemisinin inhibits the expression of vascular endothelial growth factor in K562 cells].

AIM: To study the effect of dihydroartemisinin (DHA) on vascular endothelial growth factor (VEGF) expression in K562 cells and assess the effect of DHA on leukemic angiogenesis induced by K562 cells. METHODS: Firstly, analyzed the anti-proliferation effect of DHA on K562 cells and assessed the inhibitory effect on expression of VEGF in K562 cells. Further, the conditioned medium (CM) of K562 cells pretreated with DHA was assessed for its stimulating effect on proliferation of endothelial cells and angiogenesis on chicken chorioallantoic membrane (CAM) model. RESULTS: DHA effectively inhibited the proliferation of K562 cells in vitro, and the IC50 was 13.08 micromol x L(-1). The VEGF level of K562 cells was significantly lowered after treated with DHA for 48 h, even at a lower concentration (2 micromol x L(-1), P < 0.05). The stimulating effect on proliferation of endothelial cells and angiogenesis on CAM model were weakened in response to the CM from K562 cells pretreated with DHA in a dose-dependent manner. CONCLUSION: DHA could effectively downregulate the VEGF expression in K562 cells, and inhibit the leukemic angiogenesis induced by K562 cells.

Animals↗

PubMed2005

[Expression and prognosis significance of p73 and PCNA in laryngeal squamous cell carcinoma].

OBJECTIVE: This study was designed to investigate the expression of p73 and Proliferating Cell Nuclear Antigen (PCNA) and their association with clinical, histologic characteristics and prognosis in LSCC. METHOD: p73 protein and PCNA protein were examined by using immunochistochemical SABC staining method in 65 cases of LSCC and in 23 adjacency carcinoma cases. RESULT: p73 protein and PCNA protein in LSCC shows stronger expression than that in adjacency carcinoma, which is statistically significant (P <0.05). p73 protein positive expression shows stronger in stage III approximately IVof LSCC than that in stage I approximately II (P<0.05); it more often appears in recurrent cases than in primary cases (P <0.05). And p73 protein positive expression with distant metastasis was stronger than that in LSCC without distant metastasis (P <0.05). PCNA protein positive expression was stronger in stage III approximately IV of LSCC than that in stage I approximately II (P <0.05); it more often appears in recurrent cases than in primary cases (P <0.05). PCNA protein positive expression more frequently appears in poor differentiation of LSCC, compared to well/mediate differentiation (P <0.05); PCNA positive expression in cases with cervical lymph node metastasis and distant metastasis was stronger than that without metastasis (P <0.05). PCNA expression had a significantly stronger in patients whose survival time over 5 years than that in patients whose survival time less than 5 years (P <0.05). Analysing with multivariate Cox, the expression of PCNA is an important marker of poor prognosis (RR= 2.43, P <0.05). CONCLUSION: p73 protein positive expression may play a part in LSCC progression and function as an oncogene in the development of LSCC. PCNA positive expression was closely linked with the risk of LSCC; it can be an important predictor on evaluating the prognosis of LSCC. There was positive correlation existing between p73 protein and PCNA protein expression in LSCC.

Adult↗

PubMed2005

[Studies on flavones in the leaves of Cyclocarya paliums (batal.) Iljinsk].

To do investigation of flavones from the leaves of Cyclocarya paliums (Batal.) Iljinsk. The pure products were isolated by column chromatography of silica gel, thin layer chromatography of silica gel and column chromatography of Sephadex LH-20, their chemical structures were elucidated by NMR, IR and UV spectroscopic evidence. Four flavones were isolated from the leaves of Cyclocarya paliums. They are quercetin (I), kaempferol (II), kaempferol-7-O-alpha-L-rhamnopyranosyl (III) ,and kaempferol-4'-methoxyl-7-O-beta-D-mancopyranosyl (IV). Compounds III and IV are obtained for the first time from this plants.

Flavones↗

PubMed2005

Corneal neovascularization suppressed by TIMP2 released from human amniotic membranes.

PURPOSE: To investigate the effects of culture medium of human amniotic membrane (AM) on corneal neovascularization (CNV) induced by basic fibroblast growth factor (bFGF) in mice. METHODS: Culture medium of amniotic membrane was prepared by cultivating AM (with epithelium side up) in EGM basic medium for 3 days, and was collected separately to three groups, e.g. control (EGM only), AM with epithelium (AM) and AM without epithelium (De-AM). Corneal neovascularization was induced in mice by using micropocket assay with Hydron polymer pellets containing 100 ng bFGF. Migration and proliferation of human umbilical cord vein endothelial cells (HUVEC) were performed in Boyden chambers and by using the CyQUANT fluorescence binding assay respectively. The levels of tissue inhibitors of metalloproteinase 1 and 2 (TIMP1, TIMP2) in culture medium were determined by ELISA assay. RESULTS: CNV induced by bFGF was significantly suppressed by culture medium of amniotic membrane. When the medium was applied as an eyedrop 4 times a day for 7 days, the area of CNV was (2.48+/-0.76) mm(2),(0.64+/-0.52) mm(2) and (1.96+/-0.65) mm(2) in control, AM and De-AM group respectively. The migration and proliferation of HUVEC were strongly inhibited by culture medium of AM with epithelium, while the De-AM had no effect on the migration of HUVEC cells. The high level of TIMP2 was found in AM group, but not in De-AM group, while there was no difference in the amount of TIMP1 in medium among three groups. CONCLUSION: Culture medium of amniotic membrane significantly suppresses the corneal nevovascularization induced by bFGF. The mechanism of which at least in part is that high level of TIMP2 protein secreted or released into the culture medium of AM and inhibition of migration and growth of vascular endothelial cells.

Amnion↗

PubMed2004

The effect of ethanol-induced CYP2E1 on proteasome activity: the role of 4-hydroxynonenal.

Previous studies have shown that the induction of P450 cytochrome 2E1 (CYP2E1) is associated with the loss of proteasomal activities. To correlate the loss of proteasomal activity with CYP2E1 induction, ethanol was fed intragastrically for 1, 3, 7, and 15 days. The maximum induction of CYP2E1 (3.5-fold) occurred after 15 days of ethanol feeding. However, there was no significant decrease in the 26 S chymotrypsin-like and trypsin-like activity over this period of time. When ethanol was given to rats for 1 month, CYP2E1 was significantly induced, and the proteasomal activity was significantly decreased. These results indicate that proteasomal activity was not directly affected by ethanol or CYP2E1 induction. Since 4-hydroxynonenal (4-HNE) concentration was significantly increased at 1 month of ethanol feeding, it was suspected that 4-HNE adduct formation with proteasome subunits could be the mechanism of proteasome inhibition. Using an antibody to 4-HNE adducted proteins in Western blot analysis of the 26 S proteasome fraction isolated from the liver of alcohol fed rats, one extra band appeared around 44 kDa. When the antibody to an ATPase Rpt4 was used to stain the stripped membrane, the same band that was detected with the 4-HNE antibody was detected with the Rpt4 antibody. An adduct of 4-HNE formed with the Rpt4 subunit of 26 S could impede the association of 19 S and 20 S and thus account for the observed decrease of proteasomal activity.

Aldehydes↗

PubMed2004

Gastroprotective effect and mechanism of amtolmetin guacyl in mice.

AIM: To investigate the gastroprotective effect and mechanism of amtolmetin guacyl (AMG, MED15) in mice. METHODS: Male and female Kunming strain mice, weighing 18-22 g, were utilized in the experiment. Normal or ethanol-induced gastric mucosal damage models in mice were successfully established to investigate the gastroprotective effect and mechanism of AMG. In the experiment of gastric mucosal damage after repeated treatment with AMG, the mice were randomly divided into 5 groups: normal group, 3 AMG groups receiving (75, 150 and 300 mg/kg), and tolmetin group receiving 90 mg/kg. The mice were randomly divided into 6 groups as follows: normal group, model group, AMG groups with doses of 75, 150 and 300 mg/kg, respectively, and tolmetin group with a dose of 90 mg/kg in ethanol-induced gastric mucosal damage experiment. The severity of gastric mucosal lesions was scored from 0 to 5. Gastric tissue sections were stained with hematoxylin and eosin (HE) and examined under light microscopy. Also gastric tissue sections were stained with uranyl acetate and lead citrate, and examined under electron microscopy. In addition, nitric oxide (NO) and malondialdehyde (MDA) contents, and nitric oxide synthase (NOS) and superoxide dismutase (SOD) activities in the stomach tissue homogenates were measured by biochemical methods. RESULTS: Repeated treatment with AMG (75, 150 and 300 mg/kg) for 7 d did not induce any appreciable mucosal damage, and the average score was not significantly different from that of normal mice. In contrast, tolmetin (90 mg/kg) produced significant gastric mucosal lesions compared with the normal group (P<0.01). AMG (75, 150 and 300 mg/kg) significantly reduced the severity of gastric lesions induced by ethanol in a dose-dependent manner as compared with the model group (P<0.05, AMG 75 and 150 mg/kg vs model; P<0.01, AMG 300 mg/kg vs model). Light and electron microscopy revealed that AMG (150 and 300 mg/kg) induced minimal changes in the surface epithelium layer, without vascular congestion or leucocyte adherence. AMG (75,150 and 300 mg/kg) demonstrated dose-dependent gastroprotective effects on mice in our study. AMG (75, 150 and 300 mg/kg) could significantly increase NO content and NOS level in the stomach homogenates of mice compared with the model group (P<0.05, AMG 75 mg/kg and 150 mg/kg groups vs model group; P<0.01, AMG 300 mg/kg vs model group) respectively. Moreover, AMG (150 and 300 mg/kg) not only significantly increased SOD activities but also obviously decreased the MDA content in the stomach homogenates of mice.

Animals↗

PubMed2004

Modulated heat shock protein expression during pathogenic Vibrio alginolyticus stress of sea bream.

The effects of infective Vibrio alginolyticus and its extracellular product (ECP) on host fish function are not well understood. In this study a partial biochemical characterization of the ECP from an infective strain of V. alginolyticus isolated from diseased silver sea bream Sparus sarba was achieved and the effects of live V. alginolyticus and ECP on hepatic heat shock protein (hsp) expression was compared. The ECP fraction was found to contain several hydrolytic enzymes including both haemolytic and proteolytic activities. Intramuscular administration of ECP to sea bream resulted in vibriosis with similar pathological signs as those observed with live V. alginolyticus administration. Using quantitative immunoassays we assessed the levels of the major hsp families, hsp90, hsp70 and hsp60, in hepatic tissue of diseased sea bream between 12 and 48 h post-infection. Throughout the infective period, live V. alginolyticus did not alter hsp90 whereas ECP significantly reduced hepatic hsp90 during the late stages of acute infection. The levels of hsp70 were found to be rapidly and drastically increased with both live V. alginolyticus and ECP. The transcript levels of both gene members of the hsp70 family (hsc70 and hsp70) were significantly increased with both live V. alginolyticus and ECP. The levels of hsp60 remained unchanged with both live V. alginolyticus and ECP. The data presented in this study is the first report describing an effect of both live V. alginolytus and ECP on hsp expression in diseased fish.

Animals↗

PubMed2004

The pre-ischaemic neuroprotective effect of a novel polyamine antagonist, N1-dansyl-spermine in a permanent focal cerebral ischaemia model in mice.

The polyamine sites on the NMDA receptor complex offer a therapeutic target for focal ischaemia, potentially devoid of most side effects associated with NMDA antagonists. In this study, we investigated the effect of a novel polyamine antagonist, N(1)-dansyl-spermine (0.5-10 mg kg(-1)) in a permanent focal cerebral ischaemia model in mice, and compared its effect to that of MK-801 (0.3-3 mg kg(-1)) following administration 30 min prior to ischaemia. A battery of histological and behavioural tests was employed following permanent middle cerebral artery occlusion to assess any neuroprotective effect. Following middle cerebral artery occlusion, N(1)-dansyl-spermine (1-5 mg kg(-1)) and MK-801 (1 or 3 mg kg(-1)) caused a comparable and significant reduction in the percentage hemisphere lesion volume. Similarly, both drugs significantly reduced oedema and neurological deficit score to a similar extent. Locomotor activity in MCAO mice was not significantly improved by MK-801 or N(1)-dansyl-spermine, although N(1)-dansyl-spermine induced a trend towards significant improvement. Significant improvement in rotarod performance was observed at neuroprotective doses with both drugs. Upon comparison of the profile of effects, N(1)-dansyl-spermine at least matched the effectiveness of MK-801 as a neuroprotective agent in this model. In addition, in sham-operated control mice, N(1)-dansyl-spermine was well tolerated, in contrast to the pronounced adverse effects of MK-801 on locomotor activity and rotarod performance. In conclusion, this study has shown that N(1)-dansyl-spermine is as effective a neuroprotective drug as MK-801 in this model. Moreover, in contrast to MK-801, N(1)-dansyl-spermine could be a promising therapeutic candidate for stroke as it is well tolerated at neuroprotective doses in sham-operated animals.

Analysis of Variance↗

PubMed2004

A draft sequence for the genome of the domesticated silkworm (Bombyx mori).

We report a draft sequence for the genome of the domesticated silkworm (Bombyx mori), covering 90.9% of all known silkworm genes. Our estimated gene count is 18,510, which exceeds the 13,379 genes reported for Drosophila melanogaster. Comparative analyses to fruitfly, mosquito, spider, and butterfly reveal both similarities and differences in gene content.

Algorithms↗