Biomedical subjects

Feng Zhu

Publications and source records attributed to Feng Zhu.

At least 37 records · Page 2Linked to original sources

PubMed2006

Functional analysis of type II thioesterase of Streptomyces lydicus AS 4.2501.

Constructing a mutant strain of single gene disruption is the basis for the study of gene function and metabolomics. Systematic and complete genome sequencing is the basis of genetic manipulation. In the case of a little knowledge about the Streptomyces lydicus genome and the speculation that polyketide synthases (type I) might be responsible for the polyketide side chain biosynthesis of streptolydigin, a 588-bp fragment was amplified by polymerase chain reaction (PCR) according to the homology existing in the same functional genes among Streptomyces. A mutant strain of this gene was constructed by single crossover homologous recombination. The results of sequence analysis as well as the metabolite analysis of the mutant and the original strain by liquid chromatography/mass spectroscopy indicated that this fragment was part of type II thioesterase (TE) gene, which was required for streptolydigin biosynthesis like other type II TEs function in related antibiotics biosynthesis. Furthermore, targeted gene manipulation based on PCR was a powerful tool for studying gene function and metabolomics, especially when little was known about the genomic sequence of streptomyces.

Amino Acid Sequence↗

PubMed2006

Target organ protection from a novel angiotensin II receptor (AT1) vaccine ATR12181 in spontaneously hypertensive rats.

Hypertension produces pathophysiological changes that are often responsible for the mortality associated with the disease. It is evident that overactive renin-angiotensin systems play a central role in the development of hypertension and target organ damage associated with hypertension. We have previously found that a novel angiotensin II receptor (AT1) vaccine-ATR12181 attenuated the development of high blood pressure (BP) in spontaneously hypertensive rat (SHR) model of human essential hypertension. Our objective was to determine whether this attenuation of high BP is associated with prevention of target organ damage induced by hypertensive state. SHRs were immunized against a peptide (coded ATR12181) from the extracelluar portion of the AT1A receptor by repeated subcutaneous injections of peptide-tetanus-toxoid complex in combination with Freund's adjuvant. A 64 weeks long-term observation was performed. Repeated vaccinations resulted in the induction of anti-ATR12181 antibodies. At the end of observation, vaccinated SHRs manifested lower BP, decreased cardiac hypertrophy and attenuation of kidney injuries. mRNA levels of c-fos and c-jun in heart and kidneys were decreased in vaccinated SHRs. Since a self antigen was used, safety of vaccine was concerned. However, the signs of autoimmune diseases were not observed in the sections of heart and kidney. These data demonstrated that repeated immunization against a domain of the extracellular portion of the AT1 receptor was able to cause a target organ protection against hypertension. Active immunization against the AT1 receptor may be considered as a promising new strategy in the treatment of hypertension.

Animals↗

PubMed2006

[Clinical significance of CD117/CD34 co-expression in adult patients with acute leukemia].

BACKGROUND & OBJECTIVE: CD117 is highly expressed in acute non-lymphoblastic leukemia (ANLL), and may be used as an immunologic marker of myeloid leukemia. However CD117 is also expressed in some acute lymphoblastic leukemia (ALL) cases. CD34 is highly expressed in both ALL and ANLL. This study was to explore the clinical significance of the co-expression of CD117/CD34 in adult patients with acute leukemia. METHODS: Flow cytometry (FCM) was used to detect the positive rate and expression level of CD117 in bone marrow mononuclear cells (BMMNCs) of 92 patients with ALL and 81 patients with ANLL. The difference between the rates of CD117 expression and CD117/CD34 co-expression in ALL patients and the difference of CD117/CD34 co-expression between ALL and ANLL patients were compared. Twenty healthy individuals were set as controls. RESULTS: The positive rate of CD117 was significantly lower in ALL than in ANLL (15.2% vs. 71.6%, P<0.001). The co-expression rate of CD117/CD34 was significantly lower in ALL than in ANLL (5.4% vs. 55.5%, P<0.001). The positive rate of CD117 was significantly higher than co-expression rate of CD117/CD34 in ALL (15.2% vs. 5.4%, P=0.029). CONCLUSIONS: CD117 may be used as an immunologic marker for acute myeloid leukemia. The co-expression rate of CD117/CD34 is lower than that of CD117 alone in ALL, and therefore, this may be used in the exclusive diagnosis of ALL.

Adolescent↗

PubMed2006

[Autoantibodies against alpha1 adrenergic receptor related with cardiac remodeling in hypertensive patients by clinical observation].

OBJECTIVE: To investigate the effects of autoantibodies against alpha(-) adrenergic receptor on cardiac remodeling in patients with hypertension. METHODS: Five hundred and fifty three patients with hypertension in our hospital were selected. The autoantibodies against alpha(1) adrenergic receptor in sera of donor were detected by ELISA, and the results of echocardiography were recorded. By multiple logistic regressions, the risk factors were analyzed on left ventricular enlargement of hypertension. RESULTS: The percentage of autoantibodies against alpha(1) adrenergic receptor positive was 32.3% (179/553). There were significant difference between the positive group and negative group on the ratio of left atrial enlargement (53.6%, 44.3%, respectively; P < 0.05) and left ventricular enlargement (12.8%, 6.1%, respectively; P < 0.01). The result of regression analysis demonstrated that 4 risk factors were related to left ventricular enlargement, including male, course of disease, heart rate (HR) and autoantibodies against alpha(1) adrenergic receptor in the serum (all P < 0.05). CONCLUSIONS: The autoantibodies against alpha(1) adrenergic receptor have a relationship with left ventricular enlargement of hypertension. Patients with the activity of autoantibodies against alpha(1) adrenergic might contribute to predict cardiac remodeling.

Adult↗

PubMed2006

Quantitative analysis of types I and II collagen in the disc annulus in adolescent idiopathic scoliosis.

OBJECTIVE: To find the possible roles of collagen in the pathogenesis of AIS through studies of the distribution of the collagen I and II in the disc annulus fibrous in adolescent idiopathic scoliosis (AIS). METHODS: The disc annulus fibrous of apex curve were harvested during anterior surgery and divided into concave and convex samples. 25 AIS cases were covered in this study including 6 males and 19 females, with an average age of 14.6 years (range 12-18 years). 11 specimens were intervertebral disc from the thoracic region (from T8 to T11) and 14 sample were from lumbar discs (from L1 to L2). RT-PCR was employed to investigate the distribution and content of collagen I (220 bp) and collagen II (359 bp) in the intervertebral disc specimens. 1% agarose gel electrophoresis and the Gelwork image analysis system was used in the semi-quantitative analysis of the product. RESULTS: For the AIS group, type I collagen and type II collagen significantly increased on convex side compared with that of the concave side (p<0.01). The same trend was observed in both thoracic and lumber disc annulus fibrosis, but there was no statistical difference expect for the expression of type II collagen in convex side of disc annulus fibrous (p<0.05). CONCLUSION: The asymmetric expression of collagen I and II collagen showing that there was degeneration in the intervertebral disc of AIS. The abnormal collagen metabolism may be one of reasons in the development of AIS and probably an important factor in the progression of AIS.

Adolescent↗

PubMed2006

[Effect of high volume hemofiltration on pulmonary surfactant protein in endotoxin induced acute lung injury in dog].

OBJECTIVE: To explore the effect of high volume hemofiltration (HVHF) on pulmonary surfactant protein (SP) in endotoxin induced acute lung injury (ALI) in dogs. METHODS: Sixteen healthy male mongrel dogs were given lipopolysaccharide(LPS 650 mug/kg) via central vein within 30 minutes. After the reproduction of the model, they were divided into two groups randomly (n=8). One group received the treatment of HVHF and mechanical ventilation (MV, treatment group), while another received only MV (model group). Parameters of arterial blood gas and respiratory mechanics were recorded at basic values, after reproduction of the experimental model, and 1, 2 and 4 hours after HVHF. Content of SP-B in lung tissue homogenate was measured by protein Western blot. RESULTS: After injection of LPS, partial pressure of oxygen in artery (PaO(2)) and PaO(2)/fractional concentration of inspired oxygen (FiO(2)) began to decrease (both P<0.05). PaO(2)/FiO(2) <300 mm Hg (1 mm Hg=0.133 kPa) when ALI was reproduced. PaO(2) and PaO(2)/FiO(2) were higher in treatment group than those in model group 4 hours after HVHF (both P<0.01). Inspiratory resistance of airway (Raw) and peak inspiratory pressure (PIP) in model group were kept stable after MV. Lung dynamic compliance (Cdyn) and lung total compliance (Ctot) in model group were both decreased while ventilatory work of breathing (WOBvent) increased 4 hours after MV (all P<0.01). All parameters in the treatment group were kept stable and differences in Cdyn and Ctot were significant at 4 hours after HVHF compared to model group (P<0.01 and P<0.05). Content of SP-B in lung tissue homogenate was significantly higher in treatment group than that in model group (P<0.01). CONCLUSION: HVHF could effectively increase the content of SP-B in lung to prevent aggravation of respiratory mechanics and improve oxygenation.

Acute Lung Injury↗

PubMed2005

The tumor suppressor p16(INK4a) prevents cell transformation through inhibition of c-Jun phosphorylation and AP-1 activity.

Inactivation of the p16(INK4a) tumor suppressor protein is critical for the development of human cancers, including human melanoma. However, the molecular basis of the protein's inhibitory effect on cancer development is not clear. Here we investigated a possible mechanism for p16(INK4a) inhibition of neoplastic transformation and UV-induced skin cancer. We show that p16(INK4a) suppresses the activity of c-Jun N-terminal kinases (JNKs) and that it binds to the glycine-rich loop of the N-terminal domain of JNK3. Although p16(INK4a) does not affect the phosphorylation of JNKs, its interaction with JNK inhibits c-Jun phosphorylation induced by UV exposure. This, in turn, interferes with cell transformation promoted by the H-Ras-JNK-c-Jun-AP-1 signaling axis.

Animals↗

PubMed2005

[Trabecular bone micro-architecture in adolescent idiopathic scoliosis compared between concave and convex site of the facet joints].

OBJECTIVE: To evaluate the trabecular bone micro-structure from different sites of spine in adolescent idiopathic scoliosis patients. The target site consisted of the bilateral facet joints from apical vertebrae and from end vertebrae. METHODS: Nine AIS patients with mean age 14.9 years (range 12-17 years) and mean Cobb angle 56 degrees (ranged 48 degrees-84 degrees) were recruited into this study. Corrective surgery was indicated to these patients, and facet joint biopsies were collected during decortications for spinal fusion. Biopsy consents were obtained from patients. Bone specimens were fixed with routine histology procedures and scanned by micro computer tomography (muCT40, Scanco Medical, Switzerland). Ten pairs of facet joint were harvested from apical vertebrae and 12 pairs from end vertebrae. Three-dimensional reconstructed images with the resolution of 20 microm were achieved for histomorphometric analysis. RESULTS: The values of BV/TV (0.268 vs. 0.354, P < 0.05), TbTh (0.20 vs. 0.24, P < 0.05), TbSP (0.66 vs. 0.56, P < 0.05) and BS/BV (12.7 vs. 10.4, P < 0.05) between convex and concave side at the apex area were significantly different. No difference was found in any structural parameters between left and right side at end area, and upper thoracic (T5, 6) and thoracolumbar (T12, L1). CONCLUSION: Due to asymmetric compression and tension shared between convex and concave side, more bone and thicker and more profound trabecular bones are observed in the concave side than in the convex side, which seems to resist the progression of spinal curvature. This finding suggests that the provocative factors which cause the progression of the curve in certain patients may not lie in the bone component of spine.

Adolescent↗

PubMed2005

2-Arachidonoylglycerol stimulates activator protein-1-dependent transcriptional activity and enhances epidermal growth factor-induced cell transformation in JB6 P+ cells.

2-Arachidonoylglycerol (2-AG) is the most abundant endocannabinoid, and it plays a critical role in cannabinoid receptor-mediated cell signaling. Although 2-AG was shown to induce ERK activation via the cannabinoid receptor 1 (CB1), only a nonspecific CB receptor agonist and antagonist was used in those studies. Whether cannabinoid receptor 2 (CB2) is involved in 2-AG-induced ERK activation is still unclear. Moreover, whether 2-AG is involved in mediation of AP-1 activity and cell transformation is also not known. In the present study, we show that 2-AG stimulates AP-1-dependent transcriptional activity and enhances epidermal growth factor-induced cell transformation in mouse epidermal JB6 P+ Cl41 cells. Using JB6 P+ C141 cells, stably transfected with an AP-1 luciferase reporter, we found that 10 microm 2-AG induced up to a 3-fold stimulation of AP-1 transcriptional activity. The AP-1 stimulation appeared to be mediated by ERK but not JNK or p38 kinase. PD98059, a specific inhibitor of MEK1, almost completely blocked 2-AG-induced ERK phosphorylation and AP-1 activation. Using CB1/2-/- murine embryonic fibroblasts, we present the first direct evidence that both cannabinoid receptors 1 and 2 (CB1/2) are involved in 2-AG-induced ERK activation. 2-AG could not stimulate ERK phosphorylation or Fyn kinase activity in dominant negative Fyn. In addition, the Fyn inhibitor PP2 blocked 2-AG-induced Fyn kinase activity and ERK phosphorylation and activity. Small interfering RNA Fyn also suppressed 2-AG-induced ERK phosphorylation. Interestingly, 2-AG enhanced epidermal growth factor-induced AP-1 DNA binding and cell transformation. Taken together, our data provide direct evidence suggesting that 2-AG may have a novel role in cell transformation and carcinogenesis in a signaling pathway involving CB1/2 and activation of Fyn, ERKs, and AP-1.

Animals↗

PubMed2005

The p53 protein is a novel substrate of ribosomal S6 kinase 2 and a critical intermediary for ribosomal S6 kinase 2 and histone H3 interaction.

The tumor suppressor p53 protein is one of the most highly connected nodes in cellular signal transduction pathways and acts as a central regulatory switch in networks controlling cell proliferation and apoptosis. It is involved in the activation of genes that maintain control over cellular responses to DNA errors such as DNA repair, chromosomal recombination, and chromosome segregation. Here we show that ribosomal S6 kinase 2 (RSK2) activates and phosphorylates p53 (Ser15) in vitro and in vivo and colocalizes with p53 in the nucleus. Deficiency of p53 diminishes RSK2-mediated phosphorylation of histone H3 (Ser10) and adding back p53 to p53-/- embryonic fibroblasts restored phosphorylation of histone H3 at Ser10. These results show that the p53 protein is an important substrate of RSK2 and a critical intermediary in the RSK2 and histone H3 interaction. The RSK2-p53-histone H3 complex may likely contribute to chromatin remodeling and cell cycle regulation.

Animals↗

PubMed2005

Efficacy of omeprazole and amoxicillin with either clarithromycin or metronidazole on eradication of Helicobacter pylori in Chinese peptic ulcer patients.

AIM: One-week triple therapy with proton pump inhibitors, clarithromycin and amoxicillin has recently been proposed as the first-line treatment for Helicobacter pylori (H. pylori) infection; however, data regarding the effects of this regimen in China are scarce. The aim of this prospective and randomized study was to compare the efficacy of clarithromycin and metronidazole when they were combined with omeprazole and amoxicillin on eradication of H. pylori and ulcer healing in Chinese peptic ulcer patients. METHODS: A total of 103 subjects with H. pylori-positive peptic ulcer were randomly divided into two groups, and accepted triple therapy with omeprazole 20 mg, amoxicillin 1000 mg and either clarithromycin 500 mg (OAC group, n = 58) or metronidazole 400 mg (OAM group, n = 45). All drugs were given twice daily for 7 d. Patients with active peptic ulcer were treated with omeprazole 20 mg daily for 2-4 wk after anti-H. pylori therapy. Six to eight weeks after omeprazole therapy, all patients underwent endoscopies and four biopsies (two from the antrum and two others from the corpus of stomach) were taken for rapid urease test and histological analysis (with modified Giemsa staining) to examine H. pylori. Successful eradication was defined as negative results from both examination methods. RESULTS: One hundred patients completed the entire course of therapy and returned for follow-up. The eradication rate of H. pylori for the per-protocol analysis was 89.3% (50/56) in OAC group and 84.1% (37/44) in OAM group. Based on the intention-to-treat analysis, the eradication rate of H. pylori was 86.2% (50/58) in OAC group and 82.2% (37/45) in OAM group. There were no significant differences in eradication rates between the two groups on either analysis. The active ulcer-healing rate was 96.7% (29/30) in OAC group and 100% (21/21) in OAM group (per-protocol analysis, P>0.05). Six patients in OAC group (10.3%) and five in OAM group (11.1%) reported adverse events (P>0.05). CONCLUSION: One-week triple therapy with omeprazole and amoxicillin in combination with either clarithromycin or metronidazole is effective for the eradication of H. pylori. The therapeutic regimen comprising metronidazole with low cost, good compliance and mild adverse events may offer a good choice for the treatment of peptic ulcers associated with H. pylori infection in China.

Adult↗

PubMed2005

ADAM33 enzyme properties and substrate specificity.

ADAM33 is an asthma susceptibility gene recently identified through a genetic study of asthmatic families [van Eerdewegh, et al. (2002) Nature 418, 426-430]. To understand the function of the gene product, the recombinant metalloproteinase domain of human ADAM33 was purified and tested for its substrate cleavage specificity using peptides derived from beta-amyloid precursor protein (APP). A single Ala substitution at the P2 position of a 10-residue APP peptide, YEVHHQKLVF, yielded a 20-fold more efficient substrate. Terminal truncation studies identified a minimal nine-residue core (P5-P4') important for ADAM33 recognition and cleavage. Full positional scanning of the 10-mer peptide using the 19 naturally occurring l-amino acids (excluding Cys) revealed a substrate specificity profile. A strong preference for Val or Ile at P3, Ala at P2, and Gln at P1' was observed. The substrate binding model based on the X-ray structure of the ADAM33-inhibitor complex supported the observed substrate specificity profile. On the basis of this, an improved substrate was designed and a fluorescence resonance energy transfer (FRET) assay was developed using a fluorogenic derivative of this substrate. Kinetic studies confirmed that the best substrate, FRET-P2 [K(Dabcyl)YRVAFQKLAE(Edans)K], was approximately 100-fold more efficient than the wild-type APP peptide substrate, with a k(cat)/K(m) value of (3.6 +/- 0.1) x 10(4) s(-)(1) M(-)(1). Using this substrate and the FRET assay, ADAM33 enzyme activity and thermal stability were characterized. ADAM33 dependence on buffer conditions, detergents, and temperature was examined, and optimal conditions were defined. Accurate K(i) values for tissue inhibitors of metalloproteinase and small molecule compounds were obtained.

ADAM Proteins↗

PubMed2005

Phosphorylation of Ser28 in histone H3 mediated by mixed lineage kinase-like mitogen-activated protein triple kinase alpha.

The mitogen-activated protein kinase cascades elicit modification of chromatin proteins such as histone H3 by phosphorylation concomitant with gene activation. Here, we demonstrate for the first time that the mixed lineage kinase-like mitogen-activated protein triple kinase (MLTK)-alpha phosphorylates histone H3 at Ser28. MLTK-alpha but neither a kinase-negative mutant of MLTK-alpha nor MLTK-beta interacted with and phosphorylated histone H3 in vivo and in vitro. When overexpressed in 293T or JB6 Cl41 cells, MLTK-alpha phosphorylated histone H3 at Ser28 but not at Ser10. The interaction between MLTK-alpha and histone H3 was enhanced by stimulation with ultraviolet B light (UVB) or epidermal growth factor (EGF), which resulted in the accumulation of MLTK-alpha in the nucleus. UVB- or EGF-induced phosphorylation of histone H3 at Ser28 was not affected by PD 98059, a MEK inhibitor, or SB 202190, a p38 kinase inhibitor, in MLTK-alpha-overexpressing JB6 Cl41 cells. Significantly, UVB- or EGF-induced phosphorylation of histone H3 at Ser28 was blocked by small interfering RNA of MLTK-alpha. The inhibition of histone H3 phosphorylation at Ser28 in the MLTK-alpha knock-down JB6 Cl41 cells was not due to a defect in mitogen- and stress-activated protein kinase 1 or 90-kDa ribosomal S6 kinase (p90RSK) activity. In summary, these results illustrate that MLTK-alpha plays a key role in the UVB- and EGF-induced phosphorylation of histone H3 at Ser28, suggesting that MLTK-alpha might be a new histone H3 kinase at the level of mitogen-activated protein kinase kinase kinases.

Amino Acid Sequence↗

PubMed2005

[Cloning and subcellular localization of apr-1--a new gene of tumor specific antigen family].

BACKGROUND & OBJECTIVE: apr-1 was cloned by improved polymerase chain reaction (PCR)-based subtractive hybridization from all-trans retinoic acid (ATRA)-induced apoptotic leukemia HL-60 cells in 1999. Preliminary results showed that apr-1 might be an apoptosis-related gene (GenBank ID: NM_014061). This study was to explore the background of apr-1 through gene cloning, bioinformatic analysis, and subcellular locating. METHODS: The cDNA encoding Apr-1 was amplified by reverse transcription-PCR (RT-PCR), and sequenced. Open reading frame (ORF) of apr-1 was analyzed with ORF finder software. Chromosome locus was defined by genome blast software. Conserved domains of amino acids were analyzed by protein blast software. Align (Cluster W) software in Vector NTI software package was used to analyze homogeneous genes (or proteins), and to draw the Phylogenetic Tree. Subcellular localization of apr-1 was performed. RESULTS: apr-1 was mapped to chromosome Xp11.22 with the ORF locating in 1 exon. Two MAGE conserved domains were found in Apr-1. Apr-1 shared homology with MAGE-A1, MAGE-B1, MAGE-C1, MAGE-D1, and Necdin. Phylogenetic analysis showed that Apr-1 was more closely related to MAGE-D1 and Necdin. Gene products of apr-1 were located in the nuclei of eukaryocytes. CONCLUSIONS: apr-1 is a member of MAGE family, and might belong to type II MAGE genes.

Amino Acid Sequence↗

PubMed2005

[Study on serum leptin level of urban resident and the relationship between body mass index, blood lipid, insulin and leptin level].

OBJECTIVE: To measure serum leptin concentration of urban residents and investigate the relationship between serum leptin concentration and body mass index(BMI), blood lipid, insulin. METHODS: One hundred fifty-eight men and women ages 18-72 years were initially drawn from a community in Ji'nan City. The parameters measured included height, weight, waist and hip circumference, insulin, blood lipid and leptin concentrations. Statistical analyses were performed with SPSS11.5. RESULTS: The mean serum concentration of leptin was (17.47 +/- 13.52)ng/ml, in male subjects was (8.38 +/- 6.31)ng/ml, in female subjects it was (24.98 +/- 13.29)ng/ml. Serum level of leptin was significantly positively correlated with BMI, waist and hip circumference, not correlated with WHR. Serum leptin level in females was positively correlated with WHR. There was no association between serum level of leptin and insulin. Serum leptin level in males was positively correlated to apo B, in females was positively correlated to TC, LDL-c. CONCLUSION: BMI is an important factor to determine serum leptin level. The relationships between plasma glucose, insulin, blood lipids and serum leptin are affected by gender. In males serum leptin level was positively correlated to apo B, in females was positively correlated to TC, LDL-c. We need further research to explain this difference.

Adolescent↗

PubMed2005

[Anterior and posterior spinal growth plates in adolescent idiopathic scoliosis: a histological study].

OBJECTIVE: To investigate the morphology of the growth plates in anterior and posterior spinal column in adolescent idiopathic scoliosis (AIS) and congenital scoliosis (CS) respectively. METHODS: Seventeen AIS patients (mean age 13.6 years, ranged 10 to 17 years) were recruited in this study and 10 patients with CS (mean age 9.3 years, ranged 6 to 12 years) were selected as control group. Growth plates were harvested during anterior and posterior surgery and then were paraffin embedded, sectioned at the thickness of 6 microm, and stained with Heametoxylin and Eosin. Quantitative histomorphometric analysis was made to measure the area and height of proliferative and hypertrophic zones by image analysis system. RESULTS: In AIS, the hypertrophic and proliferative zones were significantly larger and/or higher in anterior column than those in posterior column (P < 0.05). The sizes of different subtype zones were similar in anterior and posterior columns in CS. CONCLUSION: The histological difference between anterior and posterior spinal column may exist in patients with AIS. The overgrowth of the anterior spinal column may predispose to lordotic instability and development of spine deformity.

Adolescent↗

PubMed2005

[Study on multi-photon excited fluorescence combined with capillary electrophoresis].

This paper describes a new method, multiphoton excitation fluorescence detection combined with capillary electrophoresis separation. The excitation source was a self mode-locked femtosecond titanium-sapphire laser (Spectra-physics Inc.), producing a stream of pulses with a pulse duration of about 100 fs at 82 MHz repetition rate. Its average power was about 200 mW at 750 nm. The laser beam was focused into a thin wall flow cell of capillary electrophoresis. A high numerical aperture objective (100 x NA 1.25) was chosen to focus the laser beam and to collect the fluorescence emitted by detecting molecules. Then the fluorescence was detected by a fast response PMT. All data were acquired and processed by a microcomputer. For three biological molecules, 5HT, FAD and NADH, it was demonstrated that they can be separated and detected efficiently by this method with three-photon and two-photon excitation respectively using only one 750 nm laser beam. The detection limits were 1.0 x 10(-6) mol x L(-1) for 5HT, 7.4 x 10(-7) mol x L(-1) for FAD and 9.8 x 10(-7) mol x L(-1) for NADH using the criterion of three standard deviations above background. The results are much better than those with UV absorption detection by one or two magnitudes.

Electrophoresis, Capillary↗

PubMed2005

[The preparation and quality control of Solanum lyratum Thunb Extract gel].

OBJECTIVE: To introduce the preparation and quality control of Solanum lyratum Extract Thunb gel. METHODS: The gel was prepared with Solanum lyratum Thunb Extract as main component and carbopol 940 as base material, and Solasodine was determined by TLCS. RESULTS: The preparation of this gel was feasible, its quality was reliable, its detection method was rapid, stable, and could be used to control the quality of Solanum lyratum Thunb Extract gel. CONCLUSIONS: Studies on Solanum lyratum Thunb Extract gel will find a new path for the treatment of eczema with mono traditional Chinese medicine.

Acrylic Resins↗