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Biomedical subjects

Min Hu

Publications and source records attributed to Min Hu.

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

Principal axis-based correspondence between multiple cameras for people tracking.

Visual surveillance using multiple cameras has attracted increasing interest in recent years. Correspondence between multiple cameras is one of the most important and basic problems which visual surveillance using multiple cameras brings. In this paper, we propose a simple and robust method, based on principal axes of people, to match people across multiple cameras. The correspondence likelihood reflecting the similarity of pairs of principal axes of people is constructed according to the relationship between "ground-points" of people detected in each camera view and the intersections of principal axes detected in different camera views and transformed to the same view. Our method has the following desirable properties: 1) Camera calibration is not needed. 2) Accurate motion detection and segmentation are less critical due to the robustness of the principal axis-based feature to noise. 3) Based on the fused data derived from correspondence results, positions of people in each camera view can be accurately located even when the people are partially occluded in all views. The experimental results on several real video sequences from outdoor environments have demonstrated the effectiveness, efficiency, and robustness of our method.

Algorithms↗
PubMed2006

[Bone mineral density and biomechanical characters of the augmented alveolar ridge by distraction osteogenesis using Ti-Ni shape memory alloy distractor].

OBJECTIVE: To evaluate the quality of the alveolar ridge augmented by Ti-Ni shape memory alloy (Ti-Ni SMA) distractor. METHODS: All of the mandibular premolars and the first molars were extracted from 12 adult mongrel canines. One month later, box-shaped osteotomy was carried out in the left mandibles and Ti-Ni SMA distractors were imbedded. The right sides served as blank control. The canines were killed 3 or 6 months later and specimens were taken from corresponding area of the experiment sides and the control. Bone mineral density and biomechanical function were measured. RESULTS: Bone mineral density, ultimate compressive strength and Young's Modules of the augmented ridge were lower than the blank control three months after distraction. But the indexes increased and showed no significant difference with the control six months after distraction. CONCLUSIONS: The canines mandibular posterior alveolar ridge could be augmented by distraction osteogenesis using Ti-Ni SMA distractor, and the new bone is strong enough for implant placement.

Alveolar Ridge Augmentation↗
PubMed2006

[Characteristics of mass distributions of aerosol particle and its inorganic water-soluble ions in summer over a suburb farmland in Beijing].

Agricultural activity is one of the important sources of aerosol particle. To understand the mass distribution and sources of aerosol particle and its inorganic water-soluble ions in the suburb farmland of Beijing, particle samples were collected with a MOUDI cascade impactor in the summer of 2004 in a suburb vegetable field. The mass distributions of the particle and its inorganic water-soluble ions in the diameter range of 0.18 to approximately 18 microm were measured. The dominant ions in the fine particle were SO4(2-), NOS3(-) and NH4+. The association of day to day variation of the concentration of these ions with temperature, humidity and solar radiation suggests that they are formed by the reaction of NH3 released from the vegetable field with the acid species produced from photochemical reactions. K+ in the fine particle is likely from the vegetation emission and biomass burning. Ca2+, Mg2+, NO3(-) and SO4(2-) in the coarse particle are suggested to come from the mechanical process by which the soil particle entered the atmosphere, and from the reactions of the acid species at the surface of the soil particle. The results show that fertilizer and soil are possibly important factors determining the aerosol particle over the agricultural fields, and the vegetable fields in suburb Beijing could contribute significantly to the aerosol particle.

Aerosols↗
PubMed2006

[The post-injury regenerating ability of temporomandibular joint of rats exposed to the repeated + Gz forces].

OBJECTIVE: To observe the post-injury regenerating ability of temporomandibular joint of rats exposed to the repeated + Gz forces. METHODS: One hundred and eight male rats were randomly assigned to 9 groups, with 12 rats in each group. Group A was normally fed serving as the blank control group. Group B was only fixed with rat-kept devices for 5 minutes as the fixed control group. Group C was borne +1 Gz for 5 minutes. In the same position as group C, group D, E, F, G, H and I were repeatedly exposed to +10 Gz for 30 seconds each time with 5 times a day and +1 Gz for 1 minutes as a interval. The 6 groups were treated in the condition above for 4 days a week and 4 weeks in total. The rats in group A, B, C and D were killed on the next day after the centrifuge. The rats in group E, F, G, H and I were killed at 1, 2, 4, 8 and 12 weeks after the centrifuge, respectively. After the rats were killed, temporomandibular joint were taken for observation under optical microscope, scanning electron-microscope (SEM) and transmission electron-microscope (TEM). RESULTS: There was no significant difference observed in group A, B and C. But in group D, E, F, G, H and I pathologic injuries and self-regeneration were seen in TMJ in different degrees. CONCLUSIONS: The injury of TMJ could regenerate gradually with time.

Acceleration↗
PubMed2006

[Identification of the components and products of hydrolysis in acetylleucomycin by LC-MS].

AIM: To identify the components of acetylleucomycin and its hydrolytic products by LC-MS. METHODS: Acetylleucomycin was separated on a Diamonsil C18 column with 0.1 mol x L(-1) ammonium acetate-acetontrile (35 : 65) as mobile phase. The LC-MS was equipped with an electorspray ion source (ESI), which was set at the positive ion mode, and the mass spectra of each component in chromatogram were obtained with difference cone voltage. RESULTS: The components of acetylleucomycin and its hydrolytic products can be separated by HPLC. The components were identified according to the molecular weight and its major mass fragment ions. The major components identified in domastic acetylleucomycin were acetylleucomycin A4, A5; acetylleucomycin A1, A3; acetylleucomycin A6, A7, and acetylleucomycin A13. The hydrolytic products of acetylleucomycin were not kitasamycin, but some non-complete hydrolytic product. CONCLUSION: The method is rapid, sensitive and specific. It' s suitable to application in the fields of multi-components antibiotics analysis.

Chromatography, Liquid↗
PubMed2006

[Expression and characterization of mouse 17-1A antigen from Pichia pastoris].

OBJECTIVE: This is a ground work in preparation for the development of a vaccine against tumor, in which 17-1A glucoprotein, a tumor associated antigen (TAA), was cloned and expressed in Pichia pastoris. METHODS: The cDNA of 17-1A gene was cloned from nephridial tissue of mouse embryo by RT-PCR and subsequently inserted into pPICZaA plasmid after digestion with Xho I and Xba I. The linearized recombinant plasmid was transformed into Pichia pastoris strain GS115. 17-1A glucoproteins were secreted into culture supernatant through alpha-signal peptide of AOX I after inducation with methanol. The protein products were analyzed and characterized by SDS-PAGE and Western-blot. RESULTS: The plasmid pPICZalphaA-17-1A was constructed and verified by sequenceing. 17-1A glucoproteins were expressed stably and glycosylated in Pichia pastoris. CONCLUSION: Glycosylated tumor associated antigen 17-1A can be expressed in Pichia pastoris.

Animals↗
PubMed2006

[TRAIL impacts in growth and apoptosis of human ovarian carcinoma cell line SKOV3].

OBJECTIVE: To investigate the effect of TRAIL on growth and apoptosis of ovarian carcinoma cell line SKOV3. METHODS: The effects of TRAIL alone and/or associating with DDP to treat on SKOV3 cells growth inhibition were measured by MTT assay, and the changes of DR4 and DR5 mRNA were detected by RT-PCR technique. The cell cycle and apoptosis index were analyzed by technique of Flow Cytometry (FCM). RESULTS: The soluble TRAIL protein had the inhibiting effect on the growth SKOV3 cells. The DDP increased the ability of TRAIL to SKOV3 cell growth inhibition. The apoptotic indexes (AI) of SKOV3 cells detected by FCM were 5.9%, 13.4% and 39.5% for control group, TRAIL group and TRAIL plus DDP group, respectively. The DDP increased the DR5 expressing in SKOV3 cells by 1.95 folds than control group and by 1.54 times for the DR4 expressing than the control group (P < 0.05). CONCLUSIONS: The soluble TRAIL has the effect on inhibiting the growth of SKOV3 cells. The combination use of TRAIL and DDP increases significantly the growth-inhibiting ratio to SKOV3 cells. The AI of SKOV3 cell is raised after TRAIL intervening in. The DDP can increase the expressions of DR4 and DR5 in SKOV3 cells.

Antineoplastic Agents↗
PubMed2006

[Studies on aclacinomycin spectral characters and the interaction between aclacinomycin and DNA by spectroscopic method].

The interaction of aclacinomycin(ACR) and DNA was investigated by fluorescence spectrum, and the characteristics of the fluorescence and absorption of aclacinomycin (ACR) were studied. The results indicate that there are two situations: in the case that the concentration ratio of ACR to DNA is small, the ACR is intercalated into the stacked base pairs of DNA; in the other case that the concentration ratio of ACR to DNA is great, the interaction between ACR and DNA is complex. The binding constant of the interaction between ACR and DNA, calculated by the fluorescence titration method, is 2.7 x 10(6) mol x L(-1), and the binding site number is about 0.67 base pairs.

Aclarubicin↗
PubMed2006

[Stromal cells change after epipolis laser in situ keratomileusis and laser-assisted subepithelial keratectomy in rabbits].

OBJECTIVE: To compare the effects of epipolis laser in situ keratomileusis (Epi-LASIK) and laser-assisted subepithelial keratectomy (LASEK) on the corneal stromal cells, and to evaluate their effects on corneal haze histopathologically. METHODS: Forty-eight New Zealand white rabbits (96 eyes) were randomly treated with Epi-LASIK in one eye and LASEK in the other, and 2 rabbits (4 eyes) without any treatment were used as control. Cornea stromal cell apoptosis was evaluated by terminal deoxyribonucleotidyl transferase-mediated deoxynuridine triphosphate nick end labeling (TUNEL) assay. Stromal cells proliferation and myofibroblasts generation were evaluated by immunocytochemical analyses the expression of Ki-67 and alpha-smooth muscle actin (alpha-SMA) respectively. Myofibroblast generation was further testified by Western blot analysis of alpha-SMA. Both number of TUNEL, Ki-67 and alpha-SMA positive cells and expression of alpha-SMA were semi quantitatively analyzed to explore their effects on corneal haze. RESULTS: Many TUNEL-positive cells appeared in the central anterior stromal in early stages after both LASEK and Epi-LASIK, and the number of TUNEL-positive cells reached a peak 24 hours after either LASEK or Epi-LASIK. There were more TUNEL positive cells found in LASEK group than that in Epi-LASIK group in 1 week postoperatively (t = 3.63, 7.80, 4.34, 2.95, all P < 0.01). There were a lot of Ki-67-positive cells in anterior corneal stroma after both LASEK and Epi-LASIK, but the peak appeared at 72 hours after the treatments. The significant difference was also found in the number of Ki-67-positive cell between the two treatments in 1 week postoperatively (t = 3.81, 5.85, 5.09, 5.59, all P < 0.01). alpha-SMA-positive cells started to appear apparently at 1 week after both LASEK and Epi-LASIK, and both the peaks appeared at 1 month after the treatments, and there were still a lot of alpha-SMA-positive cells in corneal stroma at 3 months after LASEK. There were more alpha-SMA-positive cells found after 1 week in LASEK group than that in Epi-LASIK group (t = 2.97, 7.19, 6.73, all P < 0.01). CONCLUSION: There are less stromal cell apoptosis, proliferation and myofibroblast generation in Epi-LASIK than that in LASEK. Therefore, comparing with LASEK, Epi-LASIK induces less corneal haze response in correcting myopia.

Actins↗
PubMed2006

[Identification of the degradation compounds of cefathiamidine by liquid chromatography-tandam mass spectrometry].

AIM: To identify the degradation compounds of cefathiamidine by a liquid chromatography-tandam mass spectrometry (LC-MS). METHODS: According to the accelerated storage condition, two main degradation compounds of cefathiamindine were its hydrolytic products. Cefathiamidine was separated on a C18 column, with 1% acetate solution-acetonitrile (85 : 15) as mobile phase. The mass spectra and MS/MS spectra were obtained with set at the positive ion mode. Combined the UV spectra and the chromatography behavior, the structures of two degradation compounds were identified. RESULTS: The method can be used for the separation of the degradation compounds of cefathiamindine. The two major degradation compounds were desacetylcefathiamidine and cefathiamidine lactone. CONCLUSION: The method is rapid, sensitive and specific, and it is suitable for the identification of the degradation compounds of cephalosporin.

Anti-Bacterial Agents↗
PubMed2006

[Experimental study on osteoking in promoting gene expression of core binding factor alpha 1 in necrotic femoral head of rabbits].

OBJECTIVE: To study the effects of Osteoking in promoting gene expression of core binding factor alpha 1 (cbfalpha 1) in necrotic femoral head of rabbits. METHODS: Rabbit model of femoral head necrosis (FHN) was induced by intravenous injection of lipopolysaccharide (LPS) 10 microg/kg body weight twice with an interval of 24 h and intramuscular injection with methyl prednisone (MPS) 20 mg/kg body weight 3 times. The dynamic changes of cbfalpha 1 gene expression in the femoral head were observed with immunohistochemistry and real-time quantitative PCR. RESULTS: The protein expression of cbfa 1 gene was negative in both model and treatment groups at the 4th week, it turned to weakly positive in the treatment group at the 8th and 12th week but still negative in the model group. The mRNA expression of cbfalpha 1 in the treatment group was 2.87 times that in the model group at the 12th week. There was no significant difference in cbfalpha 1 expression between the normal rabbits with or without Osteoking treatment. CONCLUSION: Osteoking could promote the endogenous cbfalpha 1 expression in the FHN, the effect is better along with the prolonging of the time applied. But it showed no affection on cbfalpha 1 expression in the normal femoral head of rabbits.

Animals↗
PubMed2005

Mitochondrial genomes of parasitic nematodes--progress and perspectives.

Mitochondria are subcellular organelles in which oxidative phosphorylation and other important biochemical functions take place within the cell. Within these organelles is a mitochondrial (mt) genome, which is distinct from, but cooperates with, the nuclear genome of the cell. Studying mt genomes has implications for various fundamental areas, including mt biochemistry, physiology and molecular biology. Importantly, the mt genome is a rich source of markers for population genetic and systematic studies. To date, more than 696 mt genomes have been sequenced for a range of metazoan organisms. However, few of these are from parasitic nematodes, despite their socioeconomic importance and the need for fundamental investigations into areas such as nematode genetics, systematics and ecology. In this article, we review knowledge and recent progress in mt genomics of parasitic nematodes, summarize applications of mt gene markers to the study of population genetics, systematics, epidemiology and evolution of key nematodes, and highlight some prospects and opportunities for future research.

Animals↗
PubMed2005

A putative role for psoriasin in breast tumor progression.

Psoriasin (S100A7) was identifi;ed as a gene highly expressed in psoriatic keratinocytes and highly and more frequently expressed in ductal carcinoma in situ (DCIS) than in invasive breast carcinomas (IBC), suggesting a potential role in tumor progression. Psoriasin expression is associated with poor prognostic factors in both DCIS and IBC. Several putative functions have been proposed for psoriasin in various disease types, but none of these can fully explain its involvement in breast tumor progression. Here, we show that down-regulation of endogenous psoriasin expression via stable short hairpin RNAs in a human IBC cell line (MDA-MB-468) increases cell migration and invasion without influencing cell proliferation and survival in vitro but inhibits tumor growth in vivo. These seemingly paradoxical results are potentially explained by the dramatic up-regulation and down-regulation of matrix metalloproteinase-13 and vascular endothelial growth factor (VEGF), respectively, observed in cells with decreased psoriasin levels compared with controls. Correlating with this, high psoriasin expression in human IBC is associated with increased angiogenesis and worse clinical outcome, and psoriasin mRNA levels are coordinately regulated with VEGF and other genes related to hypoxia and mitochondrial reactive oxygen species (ROS). Based on these results, we propose that psoriasin may play a role in breast tumor progression by promoting angiogenesis and enhancing the selection for cells that overcome its anti-invasive function. This hypothesis may explain why psoriasin expression is highest in high-grade and/or estrogen receptor-negative tumors, as these are associated with increased hypoxia and ROS, a setting in which the angiogenic effects of psoriasin are most important.

Animals↗
PubMed2005

Structure and mechanisms of the proteasome-associated deubiquitinating enzyme USP14.

The ubiquitin-specific processing protease (UBP) family of deubiquitinating enzymes plays an essential role in numerous cellular processes. Mammalian USP14 (Ubp6 in yeast) is unique among known UBP enzymes in that it is activated catalytically upon specific association with the 26S proteasome. Here, we report the crystal structures of the 45-kDa catalytic domain of USP14 in isolation and in a complex with ubiquitin aldehyde, which reveal distinct structural features. In the absence of ubiquitin binding, the catalytic cleft leading to the active site of USP14 is blocked by two surface loops. Binding by ubiquitin induces a significant conformational change that translocates the two surface loops thereby allowing access of the ubiquitin C-terminus to the active site. These structural observations, in conjunction with biochemical characterization, identify important regulatory mechanisms for USP14.

Amino Acid Sequence↗
PubMed2005

Genetic analysis of Trichinella populations by 'cold' single-strand conformation polymorphism analysis.

A non-isotopic single-strand conformation polymorphism ('cold' SSCP) technique has been assessed for the analysis of sequence variability in the expansion segment 5 (ES5) of domain IV and the D3 domain of nuclear ribosomal DNA within and/or among isolates and individual muscle (first-stage) larvae representing all currently recognized species/genotypes of Trichinella. Data are consistent with the ability of cold SSCP to identify intra-specific as well as inter-specific variability among Trichinella genotypes. The cold SSCP approach should be applicable to a range of other genetic markers for comparative studies of Trichinella populations globally.

Animals↗
PubMed2005

Regulation of glucagon secretion at low glucose concentrations: evidence for adenosine triphosphate-sensitive potassium channel involvement.

Glucagon is a potent counterregulatory hormone that opposes the action of insulin in controlling glycemia. The cellular mechanisms by which pancreatic alpha-cell glucagon secretion occurs in response to hypoglycemia are poorly known. SUR1/K(IR)6.2-type ATP-sensitive K(+) (K(ATP)) channels have been implicated in the glucagon counterregulatory response at central and peripheral levels, but their role is not well understood. In this study, we examined hypoglycemia-induced glucagon secretion in vitro in isolated islets and in vivo using Sur1KO mice lacking neuroendocrine-type K(ATP) channels and paired wild-type (WT) controls. Sur1KO mice fed ad libitum have normal glucagon levels and mobilize hepatic glycogen in response to exogenous glucagon but exhibit a blunted glucagon response to insulin-induced hypoglycemia. Glucagon release from Sur1KO and WT islets is increased at 2.8 mmol/liter glucose and suppressed by increasing glucose concentrations. WT islets increase glucagon secretion approximately 20-fold when challenged with 0.1 mmol/liter glucose vs. approximately 2.7-fold for Sur1KO islets. Glucagon release requires Ca(2+) and is inhibited by nifedipine. Consistent with a regulatory interaction between K(ATP) channels and intra-islet zinc-insulin, WT islets exhibit an inverse correlation between beta-cell secretion and glucagon release. Glibenclamide stimulated insulin secretion and reduced glucagon release in WT islets but was without effect on secretion from Sur1KO islets. The results indicate that loss of alpha-cell K(ATP) channels uncouples glucagon release from inhibition by beta-cells and reveals a role for K(ATP) channels in the regulation of glucagon release by low glucose.

ATP-Binding Cassette Transporters↗
PubMed2005

Chemical characterization of fine particles from on-road vehicles in the Wutong tunnel in Shenzhen, China.

Vehicle populations in China have been increasing sharply since 1990s. Vehicle emissions including various gaseous pollutants and particulate matter cause deterioration of air quality. However, measurements of particulate mater from on-road vehicles in China are scarcely reported, and thus the chemical compositions of particles emitted from vehicles in China are unknown. In this research, tunnel experiments were performed to measure PM2.5 in the Wutong tunnel, Shenzhen, China. Detailed PM2.5 chemical compositions, with organic compounds determined by GC/MS, in the tunnel were presented. Elemental carbon and organic matter composed 63% and 34% of the total PM2.5 mass in the Wutong tunnel, respectively. Alkanes, PAHs, hopanes, fatty acids, and dicarboxylic acids were the major identified organic compounds, and their source profiles in the PM2.5 in the Wutong tunnel were characterized. The comparisons of our measurements with those in the literature were also made to demonstrate the characteristics of the vehicle source profiles in the Wutong tunnel. The experimental results in this paper can improve understanding of particulate matter emitted from vehicles in China.

Air Pollutants↗