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Biomedical subjects

Pei Li

Publications and source records attributed to Pei Li.

At least 19 recordsLinked to original sources
PubMed2007

Amine-containing core-shell nanoparticles as potential drug carriers for intracellular delivery.

The present study aimed at exploring the use of amine-containing core-shell nanoparticles as potential drug carriers for intracellular delivery. Stable nanoparticles (100-200 nm in diameter) that consisted of poly(methyl methacrylate) (PMMA) cores with hydrophilic poly(ethyleneimine) (PEI) shells were synthesized and used to study their complexation with model drug, ibuprofen (IB), and release it under various electrolyte concentrations. The complexed IB/PEI-PMMA nanoparticles were characterized with FTIR, photon correlation spectroscopy, zeta-potential, and transmission electron microscopy (TEM). Results suggested that the PEI-PMMA nanoparticles could effectively complex with the IB via electrostatic interaction. The thick PEI shells ( approximately 30 nm) significantly enhanced the drug loading capacity up to 23% (w/w) of the complexed nanopartricle. In vitro release of the drug from the complexed nanoparticles was sensitive to the ionic strength of the media. Study of cellular entry of fluorescently labeled IB/nanoparticle complexes using a confocal laser scanning microscopy demonstrated that the entry of the complexed nanoparticles strongly depended on the complexing ratio between IB and PEI-PMMA nanoparticles.

Aziridines↗
PubMed2006

Development, utilization of introgression lines using a synthetic wheat as donor.

A series of introgression lines (ILs) were generated from repeated backcrossing between the exotic hexaploid wheat genotype Am3 and the common wheat genotype Laizhou953. Am3 was synthesized by crossing Triticum carthlicum with Aegilops tauschii and was used as the donor parent in this study, and Laizhou953 was used as the recurrent parent. Two hundred and five SSR markers showing polymorphism between the two parents were used to identify the introgressed Am3 chromosome segments in 97 BC4F3 ILs. The introgressed segments in each line and the length of the introgressed segments were estimated according to the wheat SSR consensus map. The introgressed segments from Am3 in the 97 lines covers 37.7% of the donor genome. The introgressed segments were most found on 2D, 3B, 6B, and 1D with coverage of 59.8, 59.5, 59.1, and 59% of the chromosomes, respectively. None of the 97 lines tested contained chromosome 4D segments introgressed from Am3. Introgressed segments for each of the chromosomes were mapped using the consensus wheat linkage map. Nine agronomic traits from BC4F3 lines were evaluated and the phenotype showed most lines have the tendency to be more similar to the recurrent parent. There were lines showing better agronomic traits than the recurrent parent, which indicated the introgression of favorable alleles from the exotic hexaploid wheat into the elite cultivar Laizhou953. Marker and phenotype data were used to identify quantitative trait loci (QTLs) controlling these nine traits. In total, 38, 33, and 28 putative QTLs were detected for seven of the nine traits in 2003, 2004, and 2005, respectively. Some of these agronomic important QTLs were detected in more than one season.

Alleles↗
PubMed2006

Formation of nanostructured materials via coalescence of amphiphilic hollow particles.

A new, simplified route to amphiphilic core-shell nanotubes, microfibers, and microrods has been developed that does not involve the traditional utilization of well-defined block copolymers. Thus, amphiphilic graft copolymers (PEI-g-PMMA) are prepared by an aqueous free radical polymerization that self-assemble in situ to form uniform core-shell nanoparticles. The hydrophobic homopolymer (PMMA) that is also formed is incorporated in the cores. Slight cross-linking of the shells followed by extraction of the homopolymer results in hollow nanoparticles that coalesce to form nanotubes. When the shells are not cross-linked, the hollow particles coalesce to form microrods and microfibers. The sizes and shapes of the micromaterials can be controlled by varying the experimental conditions.

Journal Article↗
PubMed2006

Intracellular uptake and release of poly(ethyleneimine)-co-poly(methyl methacrylate) nanoparticle/pDNA complexes for gene delivery.

Our previous studies demonstrated that cationic nanoparticles composed of well-defined poly(methyl methacrylate) (PMMA) cores surrounded by a hairly poly(ethyleneimine) (PEI) shells have comparative advantages over the PEI system for gene delivery. In this study, we focused on the intracellular uptake and release of PEI-PMMA nanoparticle/pDNA complexes. The behavior of the nanoparticle/pDNA complexes in recipient cells was monitored by using confocal laser scanning microscopy. We found that the nanoparticle/pDNA complexes were internalized very effectively by endocytosis. In the recipient cells the nanoparticles were found localized in the cytoplasm. At the same time, the pDNA carried by the nanoparticles successfully detached from the nanoparticles and localized in the nucleus of the HeLa cells.

Active Transport, Cell Nucleus↗
PubMed2006

Expression profile of metastasis-associated genes in esophageal squamous cell carcinoma.

The differentially expressed genes between esophageal squamous cell carcinoma (ESCC) with or without lymphatic metastasis were investigated by gene chip, and the lymphatic metastasis-associated genes were screened out. Expression array was used to detect the mRNA from both the primary carcinoma and the corresponding esophageal epithelium in 15 cases of human ESCC. The lymphatic metastasis-associated genes were screened by bioinformatics between ESCC with or without lymphatic metastasis. The results showed that 43 (4.85 %) genes significantly differed between the ESCC with and without lymphatic metastasis (P<0.05), of which 18 (2.03 %)were upregulated and 25 (2.82 %) down-regulated. The up-regulated genes were involved in cell adhesion molecules and cell membrane receptors and the down-regulated genes were mostly cell cycle regulators and intracellular signaling molecules. It was suggested that lymphatic metastasis-associated genes were screened by gene chip, which was helpful to understand the molecular mechanism of ESCC lymphatic metastasis and lymphatic metastasis-associated genes might be used as diagnostic markers and therapeutic targets for lymphatic metastasis.

Adult↗
PubMed2006

[cDNA microarray-based study of gene expression profile changes in human esophageal squamous cell carcinoma].

OBJECTIVE: To investigate the differentially expressed genes between human esophageal squamous cell carcinoma (ESCC) and normal esophageal mucosa and explore an effective method with high throughput for screening the molecular markers closely correlated with the development, invasion and metastasis of ESCC. METHODS: With cDNA microarray and laser capture microdissection, T7-based amplification were used to detect the mRNA from both the primary carcinoma and the corresponding esophageal epithelium in 15 ESCC cases, and the results were analyzed by bioinformatics methods. RESULTS: Among the 886 target genes, 110 (12.42%) genes were differentially expressed commonly at least twice in all the 15 samples, including 56 (6.32%) up-regulated by at least 2 folds and 54 (6.09%) down-regulated by at least 0.5 folds. CONCLUSION: Many ESCC-associated genes were screened by the high-throughput gene chip method, and functional study of these genes may help to identify the key genes or pathways involved in the pathogenesis and development of ESCC.

Carcinoma, Squamous Cell↗
PubMed2005

A simple self-assembly method for colloidal photonic crystals with a large area.

Colloidal photonic crystals were fabricated using polystyrene particles (180 nm) and PMMA particles (450 nm), respectively, with a new and simple self-assembly method without special equipment. SEM images indicate that the prepared samples have ordered structures with few defects. The position of the stop-band scale nicely agrees with the particles' size. The sintering process of the PS photonic crystal film was studied with AFM heating system.

Journal Article↗
PubMed2005

Development of wheat near-isogenic lines for powdery mildew resistance.

Using three Chinese wheat cultivars, 'Bainong 3217', 'Beijing 837' and 'Laizhou 953', as recurrent parents, 33 near-isogenic lines (NILs) carrying 22 powdery mildew resistance genes (Pm1c, Pm2, Pm4b, Pm12, Pm13, Pm16, Pm20, Pm21, Pm23, and 13 undocumented genes) were developed. All NILs had no significant difference to their recurrent parents in the investigated traits of agronomic importance. The results of AFLP analysis indicated Jaccard's genetic similarity of the NILs with their recurrent parents varied from 0.96 to 0.98, and confirmed that the NILs had high genetic similarity with their recurrent parents. The resistance to powdery mildew was stably expressed by the relevant NILs. Eleven of the NILs were tested using molecular markers linked to the resistance genes Pm1c, Pm4b, Pm13, Pm21, PmP, PmE, PmPS5A, PmPS5B, PmY39, PmY150, and PmH, and they were all found to carry the targeted genes. The potential application of these NILs in gene discovery is discussed.

Crosses, Genetic↗
PubMed2005

[The creation of laosun yutie plaster and safety experiment].

OBJECTIVE: To create an externally-applied TCD plaster (Laosun Yutie plaster) for the lumbar muscle strain (LMS). METHOD: (1) The raw material such as angelica, safflower, frankincense, myrrh, clove and so on were turned into solid TCD plaster by a serial of modern treatment technology-distillation, extraction, condense, dehydration. Meanwhile, the naphtha from the distillation process and borneol were dissolved into ethanol solution and the dilution was thus made; (2) The solid TCD plaster and the dilution from the aboved-mentioned process were put together to form the TCD plaster and the corresponding safety experiments were applied to rabits' skin. RESULT: The experimental results showed that it is neither of urgent toxicity, stimulary function, nor of allergy-inducing response. CONCLUSION: The laosun Yutie plaster was a newly externally-applied TCD plaster which could be used safely and handily.

Administration, Cutaneous↗
PubMed2005

[Acupuncture and moxibustion in Germany].

Although Germany is an important cradle of Western medicine, traditional Chinese acupuncture and moxibustion are widely accepted and have been developed hardly in Germany for several centuries. This paper reviews the development courses of acupuncture and moxibustion in Germany, and gives an introduction to the level of acupuncture and moxibustion science, acupuncture in medical insurance, acupuncture research, acupuncture clinics, acupuncture organizations, acupuncture journals and trend of acupuncture development in Germany.

Acupuncture↗
PubMed2005

[PEI-PMMA cationic nanoparticles as carriers for gene transfer].

AIM: To investigate the properties of cationic nanoparticles composed of poly (ethyleneimine)-g-poly (methyl methacrylate) (PEI-PMMA) as gene delivery carriers and explore the mechanism of PEI-PMMA nanoparticles mediated gene transfer. METHODS: PEI-PMMA nanoparticles were synthesized by free radical polymerization. The morphology of nanoparticles was observed by scanning electron microscopy. The particle size and zeta potential were measured by zeta sizer. The complex between pGL3 plasmid and nanoparticles was analyzed by gel electrophoresis; and PEI-PMMA nanoparticles mediated gene transfer into HeLa cells was observed by confocal laser scanning microscopy. RESULTS: PEI-PMMA nanoparticles are spherical shape and monodispersity. The particle size and zeta potential are 172 nm and +50.3 mV, respectively. When pGL3 plasmid complexed with nanoparticles at N/P ratio of 5: 1 and 20: 1, the particle size of pGL3/nanoparticle complex are 133 and 139 nm and zeta potential is + 21.4 and + 33.7 mV, respectively. pGL3 plasmid complexed with nanoparticles completely at N/P ratio of 5: 1. PEI-PMMA nanoparticles can deliver pGL3 plasmid into HeLa cells by endocytosis and release pGL3 into the cytosol. CONCLUSION: PEI-PMMA nanoparticles effectively transferred DNA to target cells and it is a promising non-viral carrier for gene delivery.

DNA↗
PubMed2004

[Protective effect of ketamine against septic shock in rats].

OBJECTIVE: To investigate the effects and the mechanism of ketamine on hemodynamics and pro-inflammatory cytokine levels of plasma in septic shock rats. METHODS: Cecal ligation and puncture (CLP) was used to reproduce septic shock model. Twenty healthy and male Sprague-Dawlay (SD) rats weighing (225+/-25) g were randomly divided into four equal groups: Sham CLP group, CLP group, ketamine I (KT I) and ketamine II (KT II) group. Thirty minutes before CLP, normal saline (0.9 %) was infused continuously at a rate of 5 ml.kg(-1).h(-1) through the left femoral vein cannula in sham CLP and CLP group, and ketamine (5 mg.kg(-1).h(-1) and 10 mg.kg(-1).h(-1), respectively) was infused continuously in KT I or KT II group. The right femoral artery was cannulated to monitor mean arterial pressure. The plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured using enzyme-linked immunosorbent assays (ELISA). RESULTS: CLP produced progressive hypotension, and a large increase in the plasma TNF-alpha and IL-6 concentrations. The hemodynamic responses were reversed and the cytokine responses were suppressed in ketamine treated animals. CONCLUSION: Ketamine administration has protective effect against septic shock in CLP rats.

Analgesics↗
PubMed2003

[Experience of perioperative nursing of benign prostate hyperplasia patients with diabetes].

OBJECTIVE: To study the perioperative nursing the benign prostate hyperplasia (BPH) patients with diabetes mellitus. METHODS: The nursing and treatment of 126 BPH patients with diabetes mellitus were investigated. RESULTS: Satisfactory nursing effect was seen in 122 of the patients, and postoperative improvement was significantly associated with post-void residual urine volume and urine flow in the 122 patients. CONCLUSIONS: Perioperative nursing lays an important base for successful operation and ensures curative effect of BPH patients with diabetes mellitus.

Aged↗
PubMed2003

[Capturing-ELISA for the detection of anti-HCMV-IgM antibody in serum].

BACKGROUND: To develop a capturing-ELISA for the detection of anti-HCMV-IgM antibody in serum. METHODS: The anti-HCMV-IgM antibody was detected in 68 patients with HCMV infection by the capturing-ELISA, and the results were compared with those of indirect ELISA. RESULTS: The specificity and sensitivity of the capturing-ELISA were shown to be significantly higher than those of indirect ELISA, and its results were not affected by RF factor. CONCLUSION: The capturing ELISA is specific, sensitive, convenient and reliable method which may be feasible for clinical use.

Antibodies, Viral↗
PubMedDate not supplied

Role of low-molecular-weight heparins in the treatment of sudden hearing loss.

OBJECTIVE: For the present, no definitive treatment is universally accepted for sudden sensorineural hearing loss (SNHL). The goal of this study was to evaluate the role of low-molecular-weight heparins in its therapeutic regimen. METHODS: A retrospective analysis has been taken in 100 patients with SNHL in which they were divided into 2 groups: 50 patients received commonly therapy added with and without low-molecular-weight heparins each. The audiogrametric data at pretreatment were compared with data at day 10 and with data collected at follow-up (average 20 days). RESULTS: The results showed that there was a significant improvement for early or late audiometric outcome in group 1 when compared with group 2 (P <.05). Forty-three patients (86%) were classified into recovery or good improvement in group 1, which was higher than group 2 (P <.01). The improvement rate was calculated for each of the 100 patients, and the average value was 84. Seventy percent in group 1 and 70% in group 2. CONCLUSION: It is concluded that the use of low-molecular-weight heparins not only considerably improve the curative rate in the hearing improvement of sudden sensorineural hearing loss but without such potential risk as unfractionated heparins.

Adult↗