Search PubMed⌕ Search

Biomedical subjects

Jing Hu

Publications and source records attributed to Jing Hu.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Ultrastructure of poly-DL-lactic acid as GTR membrane of soft tissue defects in goats palates].

OBJECTIVE: To study the ultrastructure changes of PDLLA as GTR membrane of soft tissue defects in the palates of goats. METHODS: To establish penetrating rectangle palate defects in 8 goats. PDLLA membranes were implanted into the defect areas to guide the regeneration of the soft tissue defects. In 1, 2, 4, 6 months after the operation, the membranes were observed with scanning electron microscope. RESULTS: The surface of PDLLA membrane was regular network before implantation. 1 month after the implantation, the edge of network became blunt. 2 months after the implantation, the surface of PDLLA membrane became coarse and irregular. 4 months after the implantation, PDLLA membrane network collapsed. 6 months after the implantation, PDLLA degraded into scraggly accumulation. CONCLUSION: PDLLA membrane supplies good supporting function during concrescence of the soft tissue defects. PDLLA gradually loses mechanic intensity and is absorbed.

Animals↗
PubMed2006

[Effects of mesenchymal stem cells transplantation on cranial suture distraction osteogenesis in growing goats].

OBJECTIVE: To observe the effects of mesenchymal stem cells (MSCs)on cranial suture under mechanical strain in growing goats. METHODS: 10 growing goats were used in this study. A customized distractor was used for distraction of the coronal suture at a rate of 0.4 mm/day for 8 days. The experimental group(5 goats) was injected with autologous MSCs into the distracted region, whereas the control group (5 goats) with injection of physiological saline. All animals were killed at 4 weeks after the end of distraction. Scanning electron microscopy and histological analysis were taken to observe the samples. RESULTS: 4 weeks after the end of distraction, the cranial sutures in all animals were separated successfully. The new bone formation at the edge of suture in the experimental group was superior to that in the control group. CONCLUSION: Autologous MSCs transplantation may promote the cranial suture distraction osteogenesis in the growing goats.

Animals↗
PubMed2006

[Effects of acupuncture on the cortical functional areas activated by index finger motion in the patient with ischemic stroke].

OBJECTIVE: To observe the effect of acupuncture on cortical functional areas of the patient with ischemic stroke activated by the index finger motion. METHODS: The cortical magnetic resonance imaging (fMRI) were carried out in 15 cases of ischemic stroke during the index finger motion at acupuncture or non-acupuncture. The distribution of the cortical functional areas activated and the size of the activated region and the intension of signals were measured. RESULTS: The finger motion with no acupuncture could activate the contralateral primary somatomotor area (M1), contralateral premotor area (PMA) and contralateral first somatosensory area (S1). The finger motion with acupuncture could activate the same areas and also activate ipsilateral M1, focus area contralateral superior parietal lobule, contralateral superior temporal gyrus, and contralateral insular lobe, etc.. Both the area of the activated region and the minimum signal in the finger motion with acupuncture were statistically significantly larger than those in finger motion with no acupuncture. CONCLUSION: Rehabilitation of motor functions of the patient with ischemic stroke by acupuncture is related with improvement of blood circulation functional area in the cortex.

Acupuncture Therapy↗
PubMed2006

[Screening, isolation and identification of nisin resistance determinant gene in strains of Lactococcus lactis].

OBJECTIVE: To isolate and identify nisin resistance determinant (NSR) gene from Lactococcus lactis. METHODS: The Lactococcus lactis strains harboring NSR gene were isolated from different milk samples by selective culture supplemented with nisin and confirmed by PCR detection of 16S rRNA. Nisin resistance determinant gene was determined by PCR amplification, enzyme digestion and sequencing. RESULTS: Thirty nisin-resistant Lactococcus lactis strains from fresh milk samples were obtained. Three of these strains contained NSR gene of about 1000 bp as determined by agarose gel electrophoresis and further confirmed by enzyme digestion and sequence analysis. The NSR gene was located on the plasmid of Lactococcus lactis. CONCLUSION: Complete NSR gene, located on the bacterial plasmid, has been successfully isolated from nisin-resistant Lactococcus lactis strains from fresh milk.

Animals↗
PubMed2006

An observation on the acupuncture treatment of ischemic wind-stroke with different lengths of needle-retaining time.

OBJECTIVE: To observe the effects of different lengths of needle-retaining time on the therapeutic results of acupuncture treatment for ischemic wind-stroke. METHODS: According to the severity of disease, 251 cases of ischemic wind-stroke were randomly divided into 3 groups and treated by acupuncture, with the needle-retaining time lasting 20, 40, and 60 minutes respectively. Observation was mainly focused on the scores of nervous dysfunction and the clinical therapeutic results. RESULTS: The comparison of the scores of nervous dysfunction in the 3 groups before and after the treatment showed that under Wilcoxon's pair-match symbol rank test, except for horizontal gaze, other indexes all showed significant differences (P < 0.01). In the between-group comparison before and after the treatment, there showed significant or very significant differences in the indexes of myodynamia of the upper limb, myodynamia of hand and the total scores (P < 0.05, P < 0.01). In the between-group comparison by Mann-Whitney rank test of the indexes of myodynamia of upper limb, myodynamia of hand and the total scores, the 20-min. group and the 60-min. group showed significant differences (P < 0.05); and 40-min. group and 60-min. group showed significant differences in myodynamia of upper limb (P < 0.05). In comparison of the therapeutic effects of the 3 groups by Kruskal-wallis rank test, there showed very significant differences (P < 0.01). In the between-group comparison by Mann-Whitney rank test, the 40-min.group and 60-min. group showed significant differences (P = 0.013); while the 20-min. group and 60-min. group showed very significant differences (P = 0.000). CONCLUSION: There is a time-effect relationship between the length of needle-retaining time and the therapeutic effects of acupuncture for ischemic wind-stroke.

Acupuncture Therapy↗
PubMed2006

MEF2A gene and susceptibility to coronary artery disease in the Chinese people.

OBJECTIVE: To explore MEF2A gene and susceptibility to coronary artery disease in the Chinese. METHODS: One hundred seventy-five coronary artery disease (CAD) patients and 228 normal subjects were recruited and their blood samples were amplified to detect sequences of all 11 exons of MEF2A gene by PCR. Single-strand conformational polymorphism (SSCP) analysis was used to detect the mutation. The amplified products were purified and sequenced. RESULTS: The tri-nucleotide (CAG) length polymorphism in the last coding exon of MEF2A in the Chinese was revealed and 4 of the 175 (2.3%) CAD samples containing 4 prolines were due to one proline deletion in MEF2A gene. But all the 228 normal subjects contained 5 prolines. The mutation in both 175 CAD samples and 228 normal subjects was not found in other exons. CONCLUSION: The deletion mutation in exon 11 in MEF2A gene may be related to CAD susceptibility in the Chinese population.

Base Sequence↗
PubMed2006

[P21 expression in renal interstitial fibrosis and regulative effect of enalapril].

OBJECTIVE: To investigate the expression of P21 in renal interstitial fibrosis rats and the effect of enalapril on it. METHODS: Sprague Dawley rats were randomly divided into 3 groups: a sham operation group,a unilateral urethral obstruction group, and an enalapril treatment group. The expression of P21 in renal tubular epithelial cells on the process was detected by immunohistochemistry at different time spots (7, 14, 21 d after UUO, sham-surgery or enalapril treatment). The expression of p21 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Seven days after the surgery, significant differences were found in P21 expression between UUO and SOR renal tubular cells. With degree of interstitial fibrosis aggravating, P21 expression increased. Enalapril can inhibit its expression. CONCLUSION: In the kidney of UUO rats, P21 expression increased and enalapril possessed significant inhibitory effects on the procedure. P21 may participate in the pathogenesis of renal tubule-interstitial fibrosis.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2006

[Studies on flavonoids extraction technology from Glycyrrhiza inflata and their bacteriostatic activities].

OBJECTIVE: To study the extraction technique for the flavonoids from Glycyrrhiza inflata and their bacteriostatic bioactivities. METHODS: It was investigated about comparison of extraction methods such as ultrasonic-assisted extraction (UAE), enzymatic extraction (EE), whisk extraction (WE) and repeat freeze-dissolve extraction (FDE). The UAE conditions were optimized by orthogonal array. The bacteriostatic effect was studied using doubling dilution. RESULTS: The UAE was the most effective method and the optimal UAE conditions were adding 20-fold ethanol (30% v/v), extracting for two times, 20 min each time. Futhermore, the minimal inhibitory concentrations (MIC) of the flavonoids against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis were 0.03125, 0.03125, 0.125, 0.03125 mg/ml respectively. CONCLUSION: UAE is suitable for fast and effective extraction of flavonoids. The flavonoids have obvious bacteriostatic bioactivities against microorganisms mentioned above.

Cellulase↗
PubMed2006

[Continuous blood purification therapy in 22 children with sepsis].

OBJECTIVE: Since continuous blood purification (CBP) has the effects of eliminating inflammatory mediators and improving organs function, CBP had been applied to treat non-renal diseases for nearly 10 years, but few studies have been conducted in children with sepsis and multiorgan dysfunction syndrome (MODS), especially in China. The present study aimed to evaluate the clinical effect of CBP in treatment of children with severe sepsis and MODS. METHODS: Twenty-two children with severe sepsis and MODS admitted to our PICU from Aug. 2003 to Aug. 2005 were treated with continuous veno-venous hemodialysis filtration. Their heart rate, arterial blood pressure, doses of vasoactive agents, spontaneous respiratory rate, PO2/FiO2 and prognosis were investigated. RESULTS: Catheterization and CBP were carried out in all the 22 children. Continuous vein-vein hemodialysis filtration (CVVHDF) and pre-dilution were chosen. The duration of CBP was (64.4 +/- 34.5) h. All the children had tachycardia before CBP and the heart rate fell gradually to 45 +/- 13 bpm 4 h after CBP. Blood pressure (BP) was stable in 7 children without shock during CBP. Ten children with early shock could maintain normal BP during CBP, but the doses of vasoactive agents were tapered 1 to 5 h after beginning of CBP and use of these agents was discontinued at 2 to 8 h. BP was elevated by (25.2 +/- 10.7) mmHg (1 mmHg = 0.133 kPa) in 5 refractorily shocked children 4 h after CBP and returned to normal level 8 h later. The doses of the vasoactive drugs were reduced at 2 to 8 h and ended 4 to 16 h later, which was longer than that of children with early stage shock. The accelerated spontaneous respiratory rate was slowed down by 7 +/- 4 per minute 4 h later, PO2/FiO2 rose from (177.7 +/- 53.1) mmHg before CBP to (341.0 +/- 60.2) mmHg 4 h after CBP in children with respiratory failure and reached the normal value (5.3 +/- 2.1) h later. FiO2 declined to less than 50%. Pediatric critical illness score was 62.2 +/- 7.4 on admission and elevated to (86.6 +/- 9.0) 24 h later, which was a significant elevation as compared to that of children with sepsis who were not treated with CBP seen between Aug. 2001 and July 2003. The survival rate was 72.7% after CBP and the effective rate of the treatment was 90.9%, but was 36% in children who were not treated with CVVHDF. CONCLUSION: CBP can effectively improve the vital organ's function of children with sepsis and MODS and raise their survival rate. Replacement fluid of modified Ports formula was useful for stability of serum potassium and sodium, but resulted in elevation of serum glucose, calcium, and osmolarity. The application of CBP in children with sepsis can lead to slight drop of blood pressure at the beginning and to bleeding during CBP.

Adolescent↗
PubMed2005

Fast removal and recovery of Cr(VI) using surface-modified jacobsite (MnFe2O4) nanoparticles.

In this work, the effectiveness of surface-modified jacobsite (MnFe2O4) nanoparticles was investigated for the removal and recovery of Cr(VI) from synthetic wastewater. Ten nanometer modified MnFe2O4 nanoparticles were produced to be a new adsorbent using a co-precipitation method followed by a surface redox reaction. The equilibrium time for Cr(VI) adsorption onto modified MnFe2O4 nanoparticles was as short as 5 min, and the adsorption data fit the Langmuir model well. The maximum uptake of 31.5 mg of Cr(VI)/g of modified MnFe2O4 was obtained at pH 2, which was comparable with other common adsorbents such as activated carbon and sawdust. The effects of ligands (EDTA, SO4(2-), NH4+) and ionic strength were studied in a pH range of 2-10. EDTA and SO4(2-) inhibited the adsorption of Cr(VI) over the entire pH range studied, whereas NH4+ enhanced the uptake of Cr(VI) at pH greater than 6.5. The mechanisms leading to Cr(VI) adsorption by modified MnFe2O4 nanoparticles were determined by X-ray diffraction and X-ray photoelectron spectroscopy to be a combination of electrostatic interaction and ion exchange. Regeneration studies indicated the potential reuse of the modified MnFe2O4 nanoparticles without sacrificing adsorption capacity and the possible recycling of Cr(VI) without changing the valence.

Journal Article↗
PubMed2005

Reliability of the 0-1 test for chaos.

In time series analysis, it has been considered of key importance to determine whether a complex time series measured from the system is regular, deterministically chaotic, or random. Recently, Gottwald and Melbourne have proposed an interesting test for chaos in deterministic systems. Their analyses suggest that the test may be universally applicable to any deterministic dynamical system. In order to fruitfully apply their test to complex experimental data, it is important to understand the mechanism for the test to work, and how it behaves when it is employed to analyze various types of data, including those not from clean deterministic systems. We find that the essence of their test can be described as to first constructing a random walklike process from the data, then examining how the variance of the random walk scales with time. By applying the test to three sets of data, corresponding to (i) 1/falpha noise with long-range correlations, (ii) edge of chaos, and (iii) weak chaos, we show that the test mis-classifies (i) both deterministic and weakly stochastic edge of chaos and weak chaos as regular motions, and (ii) strongly stochastic edge of chaos and weak chaos, as well as 1/falpha noise as deterministic chaos. Our results suggest that, while the test may be effective to discriminate regular motion from fully developed deterministic chaos, it is not useful for exploratory purposes, especially for the analysis of experimental data with little a priori knowledge. A few speculative comments on the future of multiscale nonlinear time series analysis are made.

Journal Article↗
PubMed2005

Downregulation of MDM2 expression by RNAi inhibits LoVo human colorectal adenocarcinoma cells growth and the treatment of LoVo cells with mdm2siRNA3 enhances the sensitivity to cisplatin.

To investigate the biological effect of mdm2 in human colorectal adenocarcinoma LoVo cells, three mdm2siRNA constructions were recombined and transient transfected into human colorectal adenocarcinoma LoVo cells with low differentiation character in vitro. The results showed that mdm2siRNA3 reduced mRNA level of mdm2 and protein level of mdm2, leading to proliferation inhibition on LoVo cells, and reduced tumor growth in nude mice. It was found that depletion of MDM2 in this pattern promoted apoptosis of LoVo cells and Cisplatin (DDP) treated in the mdm2siRNA3 transfected cell population would result in a substantial decrease by MTT colorimetry. Decreasing the MDM2 protein level in LoVo cells by RNAi could significantly inhibit tumor growth both in vitro and in vivo, which indicated that mdm2 gene played a definite role in the development and aggressiveness of human colon carcinoma. It also could be a therapeutic target in colorectal carcinoma. The synergistic activation of RNAi and cell toxicity agents indicated that the combination of chemotherapy and gene therapy will be a promising approach in the future.

Adenocarcinoma↗
PubMed2005

Enteroaggregative Escherichia coli isolated from Chinese diarrhea patients with high-pathogenicity island of Yersinia is involved in synthesis of siderophore yersiniabactin.

AIM: To investigate the distribution of 12 high-pathogenicity island (HPI) genes and the relation between HPI genes and expression of yersiniabactin (Ybt) in enteroaggregative E.coli (EAggEC) isolated from Chinese diarrhea patients. METHODS: The distribution of 12 HPI genes was investigated by PCR and DNA hybridization in two prototype strains of EAggEC, EAggEC 17-2, EAggEC O42, and 6 clinical EAggEC isolates from China. The production of siderophore Ybt in HPI-positive strains was detected by reporter gene bioassay to determine the relation between HPI genes and expression of Ybt. Flow cytometry was used to detect fluorescent signal of the reporter strain that could designate production of Ybt. RESULTS: Seven strains were HPI-positive and one strain was HPI-negative. Six of seven HPI-positive strains were inserted into asnT-tRNA site. Moreover, seven EAggEC HPI-positive strains revealed enhanced fluorescence signal but the EAggEC HPI-negative strain did not. However, there was a difference in Ybt expression condition and level among these seven EAggEC HPI-positive strains. Although UFT073 strain, the prototype strain of uropathogenic E.coli (UPEC), carried the complete HPI core part, we did not detect the expression of Ybt in it. CONCLUSION: EAggEC HPI-positive strains can express the Ybt system, but the presence of HPI core part does not mean the functional expression of Ybt.

Animals↗
PubMed2005

The R362A mutation at the C-terminus of CA inhibits packaging of human immunodeficiency virus type 1 RNA.

The capsid (CA) sequence of human immunodeficiency virus type 1 (HIV-1) Gag protein consists of two independently folded domains named the N-terminal domain (NTD) and C-terminal domain (CTD) that are connected by a flexible linker. Most of the CTD sequence adopts rigid structure except for the last 11 amino acids (positions 354 to 364) that are disordered even in the context of the downstream SP1 and nucleocapsid (NC) sequence. Although disordered, this short peptide region plays a crucial role in HIV-1 replication. In this study, we identified three second-site mutations within Gag named A238T, G358S, and N373K that rescued a deleterious mutation R362A located at the C-terminus of CA. A238T is located within the NTD of CA, G358S and N373K are positioned proximal to R362A. One of the mechanisms underlying this compensation event is correction of reduced packaging of viral RNA into the R362A mutated viruses, as shown by the results of RNase protection assays, native Northern blots experiments as well as filter-binding assays. These data suggest that one potential function for the C-terminal disordered sequence of CA in HIV-1 replication is to regulate HIV-1 RNA packaging.

Amino Acid Sequence↗
PubMed2005

Removal and recovery of Cr(VI) from wastewater by maghemite nanoparticles.

Hexavalent chromium existing in the effluent is a major concern for the metal-processing plant. In this study, a new method combining nanoparticle adsorption and magnetic separation was developed for the removal and recovery of Cr(VI) from wastewater. The nanoscale maghemite was synthesized, characterized, and evaluated as adsorbents of Cr(VI). Various factors influencing the adsorption of Cr(VI), e.g., pH, temperature, initial concentration, and coexisting common ions were studied. Adsorption reached equilibrium within 15 min and was independent of initial Cr concentration. The maximum adsorption occurred at pH 2.5. The adsorption data were analyzed and fitted well by Freundlich isotherm. Cr(VI) adsorption capacity of maghemite nanoparticles was compared favorably with other adsorbents like activated carbon and clay. Competition from common coexisting ions such as Na+, Ca2+, Mg2+, Cu2+, Ni2+, NO3-, and Cl- was ignorable, which illustrated the selective adsorption of Cr(VI) from wastewater. Regeneration studies verified that the maghemite nanoparticles, which underwent six successive adsorption-desorption processes, still retained the original metal removal capacity. In addition, the adsorption mechanisms were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopic techniques.

Adsorption↗
PubMed2005

Quasiperiodic route to chaotic dynamics of internet transport protocols.

We show that the dynamics of transmission control protocol (TCP) may often be chaotic via a quasiperiodic route consisting of more than two independent frequencies, by employing a commonly used ns-2 network simulator. To capture the essence of the additive increase and multiplicative decrease mechanism of TCP congestion control, and to qualitatively describe why and when chaos may occur in TCP dynamics, we develop a 1D discrete map. The relevance of these chaotic transport dynamics to real Internet connections is discussed.

Journal Article↗
PubMed2005

Suppression of p65 phosphorylation coincides with inhibition of IkappaBalpha polyubiquitination and degradation.

Transcription factor nuclear factor-kappaB (NF-kappaB) is held in the cytoplasm in an inactive state by IkappaB inhibitors. Oncogenic activation of NF-kappaB is achieved by stimulus-induced ubiquitination and subsequent proteasome-mediated degradation of IkappaBalpha. Once released from the inhibitor, NF-kappaB/p65 enters the nucleus. A pre-requisite for cytokine-induced IkappaBalpha ubiquitination and degradation is the phosphorylation of IkappaBalpha at S32/S36. Phosphorylation of IkappaBalpha alone, however, is not sufficient to trigger its degradation, suggesting other events must be required for regulating IkappaBalpha degradation. In this study, we tested the hypothesis that phosphorylation of p65 at 536 is required for TNF-alpha induced IkappaBalpha proteolysis that in turn controls p65 nuclear translocation. We observed that, without affecting IkappaBalpha phosphorylation, MEK1 inhibitor U0126 treatment inhibited not only p65-S536 phosphorylation but also TNF-alpha-induced polyubiquitination of IkappaBalpha thereby inhibiting IkappaBalpha degradation. With p65 S536 phosphorylation mutants and mimics, we further observed that the structural mutation of p65 serine 536 to alanine inhibited the recruitment of ubiquitin to the p65-containing complex. As a consequence of suppressing polyubiquitination of the p65-containing complex, degradation of p65 phosphorylation mutant-bound IkappaBalpha was also inhibited. Accordingly, the nuclear translocation of phosphorylation-impaired p65 was significantly reduced. These findings suggest that p65 phosphorylation plays a key role in stimulus-induced IkappaBalpha ubiquitination.

Animals↗