Biomedical subjects

Jun Xu

Publications and source records attributed to Jun Xu.

214 records · Page 12Linked to original sources

PubMed2002

Influence of inoculum type, inorganic salt and nitrogen to carbon ratio on sclerotium formation and carotenoid production in surface culture of Penicillium sp. PT95.

This study examined the respective effect of inoculum type, inorganic salt and nitrogen to carbon ratio on sclerotium formation and carotenoid production in surface culture of Penicillium sp. PT95. Neither the spore inoculum nor the mycelial pellet inoculum could result in the formation of sclerotium on a modified Czapek agar medium after incubation of 28 days, whereas the inoculum in the form of sclerotium caused the formation of numerous orange, sand-shaped sclerotia after incubation of 14 days. Among four inorganic salts tested, K(2)HPO(4) was more essential to the sclerotium formation and carotenoid production of strain PT95 as compared to KCl, MgSO(4) or FeSO(4). It was also shown that the combination of K(2)HPO(4), KCl and MgSO(4) could produce the best positive cooperation and give the highest sclerotia biomass (782 mg/plate) and carotenoid content in sclerotium (420 microg/g of dry sclerotia) as well as pigment yield (328 microg/plate). The medium containing 0.24 approximately 0.48 g/l sodium nitrate-nitrogen was effective to both the sclerotium formation and carotenoid production of strain PT95 when available maltose-carbon concentrations were at 5.26 approximately 21.05 g/l. The optimal N:C ratio was found to be 1:25.

Biomass↗

PubMed2002

Breast reconstruction with the free bipedicled inferior TRAM flap by anastomosis to the proximal and distal ends of the internal mammary vessels.

Breast reconstruction after traditional radical mastectomy is particularly challenging for the plastic surgeon. Not only the breast, but subclavian and anterior axillary-fold deformities need to be corrected. An entire TRAM flap (including zone IV) is required, and bipedicled deep inferior epigastric vessels are needed to insure that the entire flap will survive completely. However, on the chest, it is difficult to locate the two suitable sets of recipient vessels for the two pedicles. The thoracodorsal vessels have usually been damaged during axillary dissection or radiation therapy. In the past, the proximal ends of the internal mammary artery and vein (IMA, IMV) have been used as recipient vessels with free flaps, with ligation of the distal ends. These authors have used both the proximal and distal ends of the IMA and IMV as recipient vessels for end-to-end anastomoses to the bipedicled deep inferior epigastric vessels (DIEA, DIEV) in seven clinical cases, with very satisfactory results obtained. Anatomic studies of the IMA and IMV were done in 10 dogs and two active patients, including studying hemodynamic changes at the proximal and distal ends of the IMA, and evaluation of perfusion units in the free bilateral TRAM flap. In the animal experiments, the mean pressure at the distal ends was 86/77 mmHg (left sides) and 87/78 mmHg (right sides); pressure was 63 to 71 percent of the proximal ends (p<0.05). There was no statistically significant difference between the pressures on the left and right sides. In the two patients, and in 5 others, the pressure at the distal ends was 66 and 58 mmHg, which was 75 to 77% of the pressure at the proximal ends. The blood flow at the two anastomotic stomas was similar in a 5-year follow-up. The clinical and experimental studies showed that the distal IMA has reduced perfusion pressure, but that it provides excellent flow and flap perfusion, allowing reliable use of two pedicles for survival of the entire flap.

Adult↗

PubMed2002

Craniosynostosis and altered patterns of fetal TGF-beta expression induced by intrauterine constraint.

Recent work has demonstrated that fusion of the calvarial sutures is mediated by locally elaborated soluble growth factors, including the transforming growth factor-betas (TGF-betas), leading some to speculate that external biomechanical forces play little role in suture development. Clinical evidence has long suggested, however, that fetal head constraint may play a critical role in the pathogenesis of many cases of nonsyndromic craniosynostosis. The purpose of these experiments was to test the hypothesis that intrauterine constraint leads to an alteration in normal patterns of TGF-beta expression and that these alterations are associated with craniosynostosis. Fetal constraint was induced by allowing C57Bl/6 murine fetuses to grow for 2.5 days beyond the normal 20-day gestation by performing uterine cerclage on the eighteenth day. Cranial suture morphology was examined in hematoxylin and eosin-stained sections and in cleared whole-mount specimens, double stained with alizarin red S and Alcian blue. Expression patterns of TGF-beta1 and TGF-beta3 were examined by immunohistochemical techniques. Gross and microscopic examination of the cranial sutures of 17 constrained fetuses revealed changes that ranged from narrowing to complete osseous obliteration of the coronal and squamosal sutures. All sutures of 14 nonconstrained control pups remained patent. Fetal head constraint was associated with increased TGF-beta1 immunoreactivity within the new bone and the underlying dura when compared with nonconstrained age-matched controls. TGF-beta3 immunoreactivity was associated with the dura underlying patent, nonconstrained sutures, whereas constraint-induced synostosis was characterized by down-regulation of dural TGF-beta3 expression. These experiments confirm the ability of intrauterine constraint to induce premature fusion of the cranial sutures and provide evidence that intrauterine head constraint induces the expression of osteogenic growth factors in fetal calvarial bone and the underlying dura.

Animals↗

PubMed2002

Genetic and physiological characterization of rpoB mutations that activate antibiotic production in Streptomyces lividans.

Antibiotic production in Streptomyces lividans can be activated by introducing certain mutations (rif) into the rpoB gene that confer resistance to rifampicin. Working with the most typical (rif-17) mutant strain, KO-417, the rif-17 mutation was characterized. The rif-17 mutation was shown to be responsible for activating antibiotic production and for reducing the growth rate of strain KO-417, as demonstrated by gene-replacement experiments. Gene-expression analysis revealed that introduction of rif into S. lividans elevates expression of the pathway-specific regulatory gene actII-ORF4 to nearly the same level seen in Streptomyces coelicolor. The rif effect on antibiotic production was still evident in the genetic background of relC, indicating that the rif mutation can provoke its effect without depending on ppGpp. Accompanying the restoration of antibiotic production, rif mutants also exhibited a lower rate of RNA synthesis compared to the parental strain when grown in a nutritionally rich medium, suggesting that the mutant RNA polymerases may behave like 'stringent' RNA polymerases. These results indicate that the rif mutation can alter the gene-expression pattern independent of ppGpp. The impaired growth of strain KO-417 (rif-17) was largely restored by introducing the second rif mutation (rif-18) just adjacent to the rif-17 position. Proteome analysis using two-dimensional PAGE revealed that the rif mutant strain KO-418 (rif-17 rif-18) displayed a temporal burst of expression especially of two enzymes, glutamine synthetase (type II) and oxidoreductase, during the late growth phase.

Amino Acids↗

PubMed2002

Clinical short-term results of radiofrequency ablation in liver cancers.

AIM: To study local therapeutic efficacy, side effects, and complications of radiofrequency ablation (RFA), which is emerging as a new method for the treatment of patients with hepatocellular carcinoma (HCC) with cirrhosis or chronic hepatitis and metastatic liver cancer. METHODS: Thirty-six patients with primary and secondary liver cancers (21 with primary hepatocellular carcinoma, 12 with colorectal cancer liver metastases and 3 with other malignant liver metastases), which were considered not suitable for curative resection, were include in this study. They were treated either with RFA (RITA2000, Mountain View, California, USA) percutaneously (n=20) or intraoperatively (n=16).The procedures were performed using the ultrasound guidance. The quality of RFA were based on monitoring of equipments and subject feeling of the practitioners. Patients treated with RFA was followed according to clinical findings,radiographic images, and tumor markers. RESULTS: Thirty-six patients underwent RFA for 48 nodules. RFA was used to treat an average 1.3 lesions per patient, and the median size of treated lesions was 2.5 cm (range, 0.5-9 cm). The average hospital stay was 5.6 days overall (2.8 days for percutaneous cases and 7.9 days for open operations). Seven patients underwent a second RFA procedure (sequential ablations). Sixteen HCC patients with a high level of alpha fetoprotein (AFP) and 9 colorectal cancer liver metastases patients with a high level of serum carcinoembryonic antigen (CEA) have a great reduction benefited from RFA. Four (11.1 %) patients had complications: one skin burn; one postoperative hemorrhage; one cholecystitis and one hepatic abscess associated with percutaneous ablations of a large lesion. There were 4 deaths: 3 patients died from local and system diseases (1 at 7 month, 1 at 9 month, and 1 at 12 month), 1 patients died from cardiovascular shock, but no RFA-related death. At a median follow-up of 10 months (range, 1-24 months), 6 patients (16.7 %) had recurrences at an RFA site, and 20 patients (56.7 %) remained clinically free of disease. CONCLUSION: RF ablation appears to be an effective, safe, and relatively simple procedure for the treatment of unresectable liver cancers. The rate and severity of complications appear acceptable. However, further study is necessary to assess combination with other therapies, long-term recurrence rates and effect on overall survival.

Adult↗

PubMed2002

[Treatment of partial thickness burn wound with herb plaster Tangshangxiaobogao]

OBJECTIVE: To evaluate the therapeutic effect of the herbal plaster Tangshangxiaobagao on partial thickness burn wound. METHODS: A randomized controlled trial was conducted with two herbal plasters: Tangshang-xiaobagao and Jingwanhong in 57 hospitalized burn patients. Both the effect and safety of two herbal plasters were noted in patients with partial thickness burns. RESTULTS: In superficial second degree burns, the 7 d healing rate of both groups was (61.35+/-36.26)%and (51.21+/-37.24)% and the healing time (10.56+/-3.43)d and (11.98+/-4.13)d P<0.05 respectively. While in deep second degree burns, the 14 d healing rate of both groups was (62.9+/-36.0) % and (53.9+/-32.2) % and the healing time (19.4+/-4.9)d and (21.5+/-5.5)d, respectively. Study group had lower VAS(visual analogue scale)score than control group. No obvious side effects were observed in study group. CONCLUSION: Tangshangxiaobagao is safe and may be an effective adjunct for treatment of partial thickness burn wounds.

Journal Article↗

PubMed2002

[The immunotherapeuftc effect of DNA vaccine of mite major allergen on mite extract triggered allergic pulmonary diseases].

OBJECTIVE: To assess the effects of DNA vaccine of mite major allergens on murine pulmonary allergic inflammation triggered by mite extract. METHODS: Two eukarycyte expression plasmids of Derp 1 and Derp 2 (pDerp 2-IRES-Derp 1 and pCMV-Derp 1) were constructed. BALB/c mice were divided into four groups: normal group, control group, mono-plasmid group and mixture immunization group. The latter three groups were immunized with blank plasmid, pDerp 2-IRES-Derp 1 and mixture of both pDerp 2-IRES-Derp 1 and pCMV-Derp 1, respectively. The mice were sensitized and challenged with mite extract 4 weeks later. Pathological scores, bronchoalveolar lavage (BAL) total cell count and differentiation were studied. IL-4 and IFN-gamma levels in BAL fluid (BALF) were detected by ELISA. RESULTS: Total cell count and eosinophil count in the mixture immunization group [(6 +/- 4) x 10(5)/ml], 0.05 +/- 0.04 were significantly lower than those in the control group [(21 +/- 13)10(5)/ml], 1.80 +/- 1.39, (P < 0.05). IL-4 in BALF in the mixture immunization [(168 +/- 233) g/L] group was significantly lower than that in the control group [(538 +/- 256) g/L], (P < 0.05). IFN-gamma showed no significant changes among different groups (P > 0.05). CONCLUSIONS: DNA vaccine of mite major allergens showed inhibitory effect on pulmonary allergic inflammation induced by mite extract, and this effect was more prominent in the DNA vaccine expressing two allergens than that expressing only one allergen.

Animals↗

PubMed2002

A model of (often mixed) stereotype content: competence and warmth respectively follow from perceived status and competition.

Stereotype research emphasizes systematic processes over seemingly arbitrary contents, but content also may prove systematic. On the basis of stereotypes' intergroup functions, the stereotype content model hypothesizes that (a) 2 primary dimensions are competence and warmth, (b) frequent mixed clusters combine high warmth with low competence (paternalistic) or high competence with low warmth (envious), and (c) distinct emotions (pity, envy, admiration, contempt) differentiate the 4 competence-warmth combinations. Stereotypically, (d) status predicts high competence, and competition predicts low warmth. Nine varied samples rated gender, ethnicity, race, class, age, and disability out-groups. Contrary to antipathy models, 2 dimensions mattered, and many stereotypes were mixed, either pitying (low competence, high warmth subordinates) or envying (high competence, low warmth competitors). Stereotypically, status predicted competence, and competition predicted low warmth.

Adult↗

PubMed2002

[Clinical study of the hemodynamics of both ends (proximal and distal) of internal mammary artery and its following-up].

OBJECTIVE: To verify the value of retrograde flow of Internal Mammary Artery (IMA) used as one of the supplying arteries and to develop a new method of applying IMA in breast reconstruction. METHODS: During breast reconstruction with free bilateral transverse rectus abdominis myocutaneous (TRAM) flap, the pressures and velocities of the two ends (proximal and distal) of internal mammary artery as well as the according perfusion unit (PU) of TRAM were measured in two patients who suffered from mammectomy because of carcinoma. RESULTS: The pressure at distal end was 66 or/and 58 mmHg, the pressure at proximal end was 88 or/and 75 mmHg, the former is 75%-77% of the later. The immediate rate of blood flow of distal anastomotic stoma was 74 or/and 52 ml/min, that of proximal was 94 or/and 70 ml/min, the former is 74%-78% of the later after anastomosed to the two sides of deep inferior epigastric arteries (DIEA) separately. Under condition that both ends (proximal and distal) of IMA contributing as the supplying blood vessels simultaneously, the PU of TRAM was the best. The rates of blood flow at the two anastomotic stomas are similar to each other in late stage (evaluated at the fifth year follow-up). CONCLUSION: The distal end of internal mammary artery can supply blood flow in a considerable level, similar with the proximal end.

Adult↗

PubMed2002

Effect of CYP2D6*10 genotype on propafenone pharmacodynamics in Chinese patients with ventricular arrhythmia.

AIM: To determine the effect of CYP2D6*10 genotype on propafenone pharmacodynamics in Chinese patients with ventricular arrhythmia. METHODS: Seventeen Chinese patients with ventricular premature contractions (VPC> or =1000/d) were recruited. They were normal in routine laboratory testing and administered propafenone hydrochloride 450-600 mg per day in three divided doses. Twelve lead cardiogram and 24 h Holter monitoring were performed before and after 7 d treatment of propafenone. Steady-state peak and trough concentrations of propafenone were measured by HPLC method. CYP2D6*10 genotypes of patients were assayed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: Total inhibitory rate of VPC was 79.9 % in 17 patients with ventricular arrhythmia after propafenone treatment. PR interval prolongation was increased from 0.146 s+/-0.018 s to 0.161 s+/-0.022 s (P<0.05). CYP2D6 genotypes played an important role in plasma levels and effects of propafenone. In 450 mg/d group, patients with homozygous mutant of CYP2D6*10 not only had a Cmax of propafenone two times as high as those of wild-type genotype, but also showed a two fold higher inhibitory rate of VPC compared with those with homozygous CYP2D6*1 (P<0.05). CONCLUSION: CYP2D6*10 genotype is relevant to decreased activity of CYP2D6 enzyme in Chinese patients. Elevated plasma concentration is consistent with better efficacy of propafenone in patients with ventricular arrhythmia.

Adult↗

PubMed2002

[Effects of respiratory syncytial virus infection on T-helper cytokines expression in Balb/c mice sensitized with ovalbumin].

OBJECTIVE: To determine the effects of RSV infection on the development of lung inflammation and the expressions of T-helper cell related cytokines in Balb/c mice pre-sensitized with ovalbumin. METHODS: Forty mice were randomly divided into four groups: (1) the control group: nonsensitized, noninfected; (2) the RSV group: nonsensitized, infected; (3) the OVA group: sensitized, noninfected; and (4) the OVA + RSV group: sensitized, infected (RSV 6.5 x 10(6) PFU nasal drip). Bronchoalveolar lavage (BAL) was performed in six mice from each group five days after RSV nasal inoculation. Cells in the BAL were counted and classified and the supernatants of the BALF were used for detection of IL-4 and IFN-gamma. Four mice in each group were sacrificed for lung RNA extraction, and IL-4, IL-5 and IFN-gamma mRNA levels were determined by RT-PCR. RESULTS: (1) Total BAL cells from the RSV group [(14.5 +/- 5.4) x 10(6)/ml] and the OVA + RSV group [(16.8 +/- 4.9) x 10(6)/ml] were significantly higher than those in the control group [(7.7 +/- 2.4) x 10(6)/ml] and the OVA group [(9.0 +/- 2.5) x 10(6)/ml] (all P < 0.05), with more lymphocytes in the RSV group (0.63 +/- 0.05) and the OVA + RSV group (0.77 +/- 0.09) than the control group (0.28 +/- 0.05) (P < 0.05) and the OVA group (0.36 +/- 0.03) (P < 0.05). More eosinophils were found in the OVA + RSV group (0.0690 +/- 0.0100) than in the RSV group (0.0090 +/- 0.0050), the OVA group (0.0100 +/- 0.0040) and the control (0.0030 +/- 0.0010) (all P < 0.05). (2) Pulmonary inflammation in the OVA + RSV group and the RSV group was more severe than that in the OVA group and the control group. More lymphocyte infiltration was found in the OVA + RSV and the RSV groups. More eosinophils were found in the OVA + RSV group, but not in the other groups. (3) Expression of IL-4, IL-5, and IFN-gamma mRNA: IFN-gamma mRNA expression (1.05 +/- 0.12) was higher in the RSV group, than in the control (0.00 +/- 0.00). There were only minimal expression of IL-5 mRNA and no expression of IL-4 mRNA, indicating a Th1-like cytokine response. Expressions of IL-4 mRNA and IL-5 mRNA were significantly higher in the OVA + RSV group than in the other groups, but the IFN-gamma mRNA expression was less than that in the RSV group, indicating a Th2-like cytokine response. (4) IFN-gamma activation in BALF from the RSV group [(33.8 +/- 1.1) pg/ml] was significantly higher than that in the other groups (P < 0.05), while IL-4 showed no significant change as compared to the control group. The level of IL-4 in the OVA + RSV group [(24.0 +/- 1.5) pg/ml] was significantly higher than that in all the other groups (P < 0.05). CONCLUSION: RSV infection in OVA-sensitized Balb/c mice caused a different immune response from that caused by RSV infection in nonsensitized mice. RSV infection alone resulted in a Th1-like cytokine response, while infection after OVA sensitization resulted in a Th2-like response.

Animals↗

PubMed2002

[Repair of circular cicatricial contracture of the thigh using deep inferior epigastric perforator flap].

OBJECTIVE: To provide an ideal method for repairing the circular cicatricial contracture of thigh. METHODS: Deep inferior epigastric perforator (DIEP) island flaps was elevated based only on the deep inferior epigastric artery and vein and transferred to cover the thigh wound after scar had been resected. RESULTS: Four DIEP island flaps was applied clinically and all flaps survived. The size of the flaps ranged from (8 cm x 28 cm) to (11 cm x 32 cm). Venous return and edema had been obviously improved postoperatively. There was no abdominal weakness and hernia in the donor sites. CONCLUSION: DIEP flap not only retains the advantages of TRAM flap such as good blood supply and rich tissue volume, but also preserves the integrity of the rectus abdominis muscle. DIEP island flap is a good material for repair of the circular cicatricial contracture of the thigh.

Adolescent↗

PubMed2002

[Overlapping tissue expansion techniques and its clinical applications].

OBJECTIVE: To improve the results of the soft tissue expansion technique. METHODS: Two expanders were buried in the same soft tissue pocket in an overlapping pattern. The inflation process was carried out routinely. RESULTS: 19 cases of various tissue defects were treated with the overlapping tissue expansion technique since March 1999. Good results have been achieved. CONCLUSION: The overlapping tissue expansion technique can provide much more expanded tissue and reduce complications compared with the traditional expansion technique. It is especially suitable for repair of the defects at the facial and cervical region.

Adolescent↗

PubMed2002

[A computer processing system for bronchoscopes images].

A new equipment of a computer multimedia system combined with a bronchoscope is presented here, which is able to provide active images with a high definition, image capture, synchronized video recording and playback during bronchoscopy. Its operation is easy and its quality is reliable. It is an advanced product for endoscopies and is worth while to be applied to clinical application.

Algorithms↗

PubMed1999

Synthesis, Characterization, and Reactivity of Urea Derivatives Coordinated to Cobalt(III). Possible Relevance to Urease.

The syntheses of a cobalt(III) complex, 2, containing N-(2-pyridylmethyl)urea and of six complexes, 3, containing phenyl-substituted N-2-pyridylmethyl-N'-(X)phenylureas (where X = 4-H, 4-CH(3), 4-Br, 3-Cl, 4-CF(3), and 4-NO(2)), have been accomplished by reaction of [(en)(2)Co(OSO(2)CF(3))(2)](CF(3)SO(3)) with the urea ligands in tetramethylene sulfone. The complexes have been characterized by UV-vis, FTIR, (1)H NMR, and (13)C NMR spectra along with elemental analysis. Also, X-ray crystallographic analysis of 2 confirms that the urea ligand chelates as a bidentate through the pyridyl nitrogen atom and the endo deprotonated, urea nitrogen atom to form a stable five-membered ring. Crystals of the perchlorate salt of 2 were monoclinic, space group P2(1)/c with a = 9.743(1) Å, b = 13.924(3) Å, c = 15.006(4) Å, beta = 97.07(1) degrees, and Z = 4. Reflection data (3454) with I = 3sigma(I) were refined to conventional R factors of 0.037 and 0.051. In acidic solution (0.05-1.00 M HCl at 55 degrees C), the phenyl-substituted complexes undergo hydrolysis to form the bis(ethylenediamine)(2-picolylamine-N,N')cobalt(III) ion, 4, aniline, and CO(2). The hydrolysis kinetics of the phenyl-substituted complexes were studied by UV-vis spectroscopy (I = 1.00 M HCl/LiCl). At 55 degrees C the observed rate constants fit the rate law k(obsd) = kK[H(+)]/(1 + K[H(+)]). It is proposed that the protonated urea eliminates aniline to give a coordinated isocyanate intermediate that hydrolyzes rapidly to the pyridyl methylamine complex and CO(2) via the carbamate complex. Since all of the studies of this kind to date appear to involve the NCO intermediate, it raises the prospect that urease also functions by a similar path and that urease should be tested with NCO(-) as a substrate.

Journal Article↗

PubMedDate not supplied

Treatment of advanced gastric cancer by chemotherapy combined with autologous cytokine-induced killer cells.

The effects of autologous cytokine-induced killer (CIK) (CD3+CD56+) cells together with chemotherapy were investigated in patients who suffered from advanced gastric cancers (stage IV). Fifty-seven patients were divided into two groups: chemotherapy plus CIK biotherapy and chemotherapy alone. CIK cells were induced from autologous peripheral blood mononuclear cells in vitro and separated by flow cytometry and then transfused into the patients. The T-lymphocyte subgroups (CD3+, CD4+ or CD8+), CIK cells and NK cells (CD3-CD56+) were separated and determined by flow cytometry and the serum levels of MG7-Ag, CA72-4, CA19-9 and CEA were determined by ELISA or ECLIA. It was demonstrated that the cytotoxic activity of CIK cells reached a maximum between days 14 to 21 (68.7+/-10.9% and 65.3+/-10.4%, respectively). The amounts of CIK cells were gradually increased from day 0 to day 21 and slightly decreased in the further incubations. Thereafter, the CIK cells on days 14 to 21 (with the highest population of CIK cells) transfused back to the patients. The serum levels of the tumor markers were significantly decreased, the host immune function was increased and the short-term curative effect as well as the quality of life (QOL) were improved in the patients treated by chemotherapy plus CIK cells compared to the patients treated by chemotherapy alone. Moreover, the 2-year life-span was prolonged in the group treated by chemotherapy plus CIK cells compared to the group treated with chemotherapy alone. It is concluded that chemotherapy plus CIK cells has obvious benefits for patients who suffer from advanced gastric cancers.

Adult↗