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Biomedical subjects

Jie Liu

Publications and source records attributed to Jie Liu.

At least 55 records · Page 3Linked to original sources

Treatment of gastric precancerous lesions with Weiansan.

AIM: To observe the curative effect of Weiansan (WAS) on gastric precancerous lesions (GPL) and H pylori elimination. METHODS: Seventy-six patients with GPL were randomly divided into two groups: WAS group (n = 42) and Weifuchun (WFC) group (n = 34). The patients in the WAS group were administered 5 g WAS 3 times a day, and the patients in the WFC group took WFC (4 tablets) 3 times a day. To monitor inflammation of gastric mucosa, degree of glandular atrophy (GA), intestinal metaplasia (IM) and dysplasia, and H pylori infection, all patients underwent gastroscopy and biopsy with pathological examination before and after treatment. Fifty male Sprague-Dawley (SD) rats were used in animal experiments. Of these, 10 served as the control group (n = 10), 40 were given ranitidine combined with N-methyl-N(1)-nitro-N-nitrosoguanidine (MNNG) for 12 wk and divided into 4 groups randomly: model group (n = 10), high-dose WAS group (n = 10), low-dose WAS group (n = 10) and WFC group (n = 10). Twelve weeks later, all rats were killed and a 2 cm multiply 1 cm tissue was taken from the lesser curvature of the gastric antrum. H pylori infection was determined by the fast urease method. RESULTS: The curative effect in WAS groups was similar to that in WFC groups. There was no statistical difference in degree of GA, IM and dysplasia between WAS and WFC groups. The rate of H pylori infection in the model group (positive/negative: 9/1) was significantly higher than that in the control group (positive/negative: 1/9) (P < 0.01). H pylori elimination in the high-dose WAS group (positive/negative: 4/6) and low-dose WAS group (positive/negative: 6/4) was similar to that in the WFC group (positive/negative: 4/6) (P > 0.05). CONCLUSION: WAS improves clinical symptoms by suppressing GA, IM and dysplasia and eliminating H pylori.

Adult↗

A biosynthetic pathway for anandamide.

The endocannabinoid arachidonoyl ethanolamine (anandamide) is a lipid transmitter synthesized and released "on demand" by neurons in the brain. Anandamide is also generated by macrophages where its endotoxin (LPS)-induced synthesis has been implicated in the hypotension of septic shock and advanced liver cirrhosis. Anandamide can be generated from its membrane precursor, N-arachidonoyl phosphatidylethanolamine (NAPE) through cleavage by a phospholipase D (NAPE-PLD). Here we document a biosynthetic pathway for anandamide in mouse brain and RAW264.7 macrophages that involves the phospholipase C (PLC)-catalyzed cleavage of NAPE to generate a lipid, phosphoanandamide, which is subsequently dephosphorylated by phosphatases, including PTPN22, previously described as a protein tyrosine phosphatase. Bacterial endotoxin (LPS)-induced synthesis of anandamide in macrophages is mediated exclusively by the PLC/phosphatase pathway, which is up-regulated by LPS, whereas NAPE-PLD is down-regulated by LPS and functions as a salvage pathway of anandamide synthesis when the PLC/phosphatase pathway is compromised. Both PTPN22 and endocannabinoids have been implicated in autoimmune diseases, suggesting that the PLC/phosphatase pathway of anandamide synthesis may be a pharmacotherapeutic target.

Animals↗

Optical factors determined by the T-matrix method in turbidity measurement of absolute coagulation rate constants.

Turbidity measurement for the absolute coagulation rate constants of suspensions has been extensively adopted because of its simplicity and easy implementation. A key factor in deriving the rate constant from experimental data is how to theoretically evaluate the so-called optical factor involved in calculating the extinction cross section of doublets formed during aggregation. In a previous paper, we have shown that compared with other theoretical approaches, the T-matrix method provides a robust solution to this problem and is effective in extending the applicability range of the turbidity methodology, as well as increasing measurement accuracy. This paper will provide a more comprehensive discussion of the physical insight for using the T-matrix method in turbidity measurement and associated technical details. In particular, the importance of ensuring the correct value for the refractive indices for colloidal particles and the surrounding medium used in the calculation is addressed, because the indices generally vary with the wavelength of the incident light. The comparison of calculated results with experiments shows that the T-matrix method can correctly calculate optical factors even for large particles, whereas other existing theories cannot. In addition, the data of the optical factor calculated by the T-matrix method for a range of particle radii and incident light wavelengths are listed.

Journal Article↗

Isotretinoin-loaded solid lipid nanoparticles with skin targeting for topical delivery.

The purpose of this study was to construct isotretinoin-loaded SLN (IT-SLN) formulation with skin targeting for topical delivery of isotretinoin. PRECIROL ATO 5 was selected as the lipid of SLN. Tween 80 and soybean lecithin were used as the surfactants to stabilize SLN. The hot homogenization method was performed to prepare the drug-loaded SLN. The various formulations were characterized by photon correlation spectroscopy and all the SLN formulations had low average size between 30 and 50 nm. Transmission electron microscopy studies showed that the IT-SLN formulation had a spherical shape. All the formulations had high entrapment efficiency ranging from 80% to 100%. The penetration of isotretinoin from the IT-SLN formulations through skins and into skins were evaluated in vitro using Franz diffusion cells fitted with rat skins. The in vitro permeation data showed that all the IT-SLN formulations can avoid the systemic uptake of isotretinoin in skins, however the control tincture had a permeation rate of 0.76+/-0.30 microg cm(-2)h(-1) through skins. The IT-SLN consisting of 3.0% PRECIROL ATO 5, 4.0% soybean lecithin and 4.5% Tween 80 could significantly increased the accumulative uptake of isotretinoin in skin and showed a significantly enhanced skin targeting effect. The studied IT-SLN showed a good stability. These results indicate that the studied IT-SLN formulation with skin targeting may be a promising carrier for topical delivery of isotretinoin.

Administration, Cutaneous↗

Endophytic occupation of root nodules and roots of Melilotus dentatus by Agrobacterium tumefaciens.

Agrobacterium strains have been frequently isolated from the root nodules of different legumes. Various possible mechanisms have been proposed to explain the existence of these bacteria in nodules, but there is no sufficient experimental evidence to support the estimations. In this work, we proved that the Agrobacterium strain CCBAU 81181, which was originally isolated from the root nodules of Onobrychis viciaefolia, and a symbiotic strain of Sinorhizobium meliloti CCBAU 10062 could coinhabit the root nodules of Melilotus dentatus. Analyses were performed by using a fluorescence marker, reisolation of bacteria from nodules, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole cellular proteins, and polymerase chain reaction amplification of symbiotic genes. The inoculation of A. tumefaciens CCBAU 81181 did not affect the growth and nodulation of plants. CCBAU 81181 and 24 other Agrobacterium strains isolated from nodules were incapable of nodulating on their original or alternative host and 22 strains of these strains were endophytes in the roots and stems of their hosts. Also, the tumor-inducing A. tumefaciens strains IAM 13129(T) and C58 were found capable of entering the roots of Glycyrrhiza pallidiflora, but did not cause pathogenic symptoms. With these results, we conclude that A. tumefaciens strains could be endophytic bacteria in the roots, stems, and root nodules. This finding partially explains why Agrobacterium strains were frequently isolated from the surface-sterilized nodules.

Agrobacterium tumefaciens↗

TRF2 promotes multidrug resistance in gastric cancer cells.

The role of telomere in drug resistance has not been clearly understood. Recent studies have been focused on telomerase activity and telomere length, but the findings are still controversial. It's been found that DNA double-strand breaks induced by anticancer drugs or irradiation increase TRF2 expression as an early response to DNA damage, which inhibits activation of ATM-dependent DNA damage response network, indicating TRF2 might probably be a general DNA-repair factor rather than merely a telomere-binding factor. In this study, the possible involvement of telomerase, telomere and TRF2 in DNA damage response and drug resistance was investigated. Telomere length was found elongated in multidrug-resistant variants of gastric cancer cell line SGC7901 treated with adriamycin or etoposide, however, drug-treatment per se had no effect on telomere length. Telomerase activity and TRF2 expression were upregulated after treatment, but not TRF1. TRF2 upregulation was more dramatic in drug-resistant cells and occurred before the expression of ATM, gammaH2AX and p53. Moreover, TRF2 inhibited the expression of ATM-dependent DSB responsive genes. Inhibition of TRF2 expression by RNA interference in drug-resistant cells partially reversed its resistance phenotype and overexpression of TRF2 in SGC7901 promoted its resistance phenotype. Taken together, current results indicate that TRF2 plays an important role in DNA damage response, and is involved in drug resistance of gastric cancer. Further study of the biological functions of TRF2 might be helpful to dissect the molecular mechanism of multiple drug-resistance and generate novel target to overcome it.

Antineoplastic Agents↗

Cellular prion protein promotes invasion and metastasis of gastric cancer.

Cellular prion protein (PrPc) is a glycosylphosphatidylinositol (GPI) -anchored membrane protein that is highly conserved in mammalian species. PrPc has the characteristics of adhesive molecules and is thought to play a role in cell adhesion and membrane signaling. Here we investigated the possible role of PrPc in the process of invasiveness and metastasis in gastric cancers. PrPc was found to be highly expressed in metastatic gastric cancers compared to nonmetastatic ones by immunohistochemical staining. PrPc significantly promoted the adhesive, invasive, and in vivo metastatic abilities of gastric cancer cell lines SGC7901 and MKN45. PrPc also increased promoter activity and the expression of MMP11 by activating phosphorylated ErK1/2 in gastric cancer cells. MEK inhibitor PD98059 and MMP11 antibody (Ab) significantly inhibited in vitro invasive and in vivo metastatic abilities induced by PrPc. N-terminal fragment (amino acid 24-90) was suggested to be an indispensable region for signal transduction and invasion-promoting function of PrPc. Taken together, the present work revealed a novel function of PrPc that the existence of N-terminal region of PrPc could promote the invasive and metastatic abilities of gastric cancer cells at least partially through activation of MEK/ERK pathway and consequent transactivation of MMP11.

Animals↗

Electronic and fluorescence spectral studies of a novel porphyrin-polypyridyl ruthenium(II) hybrid linked by a butyl chain.

The electronic and fluorescence spectroscopic properties of a novel porphyrin-polypyridyl ruthenium(II) hybrid, [C(4)-TPP-(ip)Ru(phen)(2)](ClO(4))(2) (TPP=5,10,15,20-tetraphenylporphyrin, ip=imidazo[4,5-f][1,10]phenanthroline and phen=1,10-Phenanthroline), in which a polypyridyl ruthenium(II) moiety is linked to a porphyrin moiety by a butyl chain have been investigated and compared to its corresponding reference compounds. The studies of electronic absorption spectra have shown that there is an electronic interaction between the porphyrin moiety and the polypyridyl ruthenium(II) moiety in the hybrid. It can be found that intramolecular photoinduced electron and energy transfer processes may occur in the hybrid from the fluorescence spectra. When exciting in Soret band and Q band of porphyrin, the fluorescence quenching of the porphyrin moiety of the hybrid takes place due to electron transfer from the lowest singlet excited state (S(1)) to the appended polypyridyl rutherium(II) moiety, while the decay of S(2) (the second-excited singlet state) of the porphyrin moiety is mainly contributed to internal conversion to S(1). When exciting in MLCT band of the polypyridyl ruthenium(II) moiety, fluorescence corresponding to the polypyridyl ruthenium(II) moiety is quenched by intramolecular energy transfer from (3)MLCT of the ruthenium moiety to the lowest-energy triplet state localized on the porphyrin moiety.

Absorption↗

Dynamics of bacteriophage T4 presynaptic filament assembly from extrinsic fluorescence measurements of Gp32-single-stranded DNA interactions.

In the bacteriophage T4 homologous recombination system, presynaptic filament assembly on single-stranded (ssDNA) DNA requires UvsX recombinase, UvsY mediator, and Gp32 ssDNA-binding proteins. Gp32 exerts both positive and negative effects on filament assembly: positive by denaturing ssDNA secondary structure, and negative by competing with UvsX for ssDNA binding sites. UvsY is believed to help UvsX displace Gp32 from the ssDNA. To test this model we developed a real-time fluorescence assay for Gp32-ssDNA interactions during presynapsis, based on changes in the fluorescence of a 6-iodoacetamidofluorescein-Gp32 conjugate. Results demonstrate that the formation of UvsX presynaptic filaments progressively disrupts Gp32-ssDNA interactions. Under stringent salt conditions the disruption of Gp32-ssDNA by UvsX is both ATP- and UvsY-dependent. The displacement of Gp32 from ssDNA during presynapsis requires ATP binding, but not ATP hydrolysis, by UvsX protein. Likewise, UvsY-mediated presynapsis strongly requires UvsY-ssDNA interactions, and is optimal at a 1:1 stoichiometry of UvsY to UvsX and/or ssDNA binding sites. Presynaptic filaments formed in the presence of UvsY undergo assembly/collapse that is tightly coupled to the ATP hydrolytic cycle and to stringent competition for ssDNA binding sites between Gp32 and various nucleotide-liganded forms of UvsX. The data directly support the Gp32 displacement model of UvsY-mediated presynaptic filament assembly, and demonstrate that the transient induction of high affinity UvsX-ssDNA interactions by ATP are essential, although not sufficient, for Gp32 displacement. The underlying dynamics of protein-ssDNA interactions within presynaptic filaments suggests that rearrangements of UvsX, UvsY, and Gp32 proteins on ssDNA may be coupled to central processes in T4 recombination metabolism.

Adenosine Triphosphate↗

Electrochemically platinized carbon paste enzyme electrodes: a new design of amperometric glucose biosensors.

A platinized carbon paste prepared via electrodeposition had a preferential electrocatalytic action toward H(2)O(2). Therefore, we have developed a new amperometric glucose biosensor based on the immobilization of glucose oxidase on to the electrochemically platinized carbon paste. The proposed biosensor is free of potential interferences due to its cathodic detection of glucose at the potential of 0.0 V (vs. Ag/AgCl). It also shows acceptable analytical performance in terms of linearity (6 x 10(-5)to 1.2 x 10(-2)M, r = 0.998), detection limit (2 x 10(-5)M), response time (20-30 s), reproducibility (RSD = 4.4%), and storage life (t(0.80) = 45 days). All these advantages of the biosensor raise potential possibilities for its medical or other biotechnical applications.

Biosensing Techniques↗

Hypersusceptibility to cisplatin carcinogenicity in metallothionein-I/II double knockout mice: production of hepatocellular carcinoma at clinically relevant doses.

Metallothionein (MT) is a high-affinity metal binding protein thought to mitigate the toxicity of various metals. Cisplatin is a widely used cancer chemotherapeutic that is a rodent carcinogen and may have carcinogenic potential in humans. MT seems to reduce cisplatin toxicity by binding the metal compound but how MT deficiency might impact the carcinogenic effects of cisplatin is unknown. Thus, groups (n = 25) of male MT-I/II double knockout (MT-null) or MT wild-type (WT) mice were exposed to a single treatment of cisplatin (5 or 10 mg/kg, i.p.), or left untreated (control) and observed over the next 104 weeks. The doses of cisplatin used equate to only a fraction of the total dose used typically in clinical settings. In cisplatin-treated MT-null mice, a dose-related increase in hepatocellular carcinoma (HCC) occurred (control, 0%; 5 mg/kg, 17%; 10 mg/kg, 36%) that was not seen in WT mice. Similarly, liver carcinoma multiplicity (HCC/liver) was increased markedly by cisplatin but only in MT-null mice, indicating the formation of multiple primaries in MT deficient mice. Harderian gland carcinoma incidence was also increased by cisplatin treatment in MT-null mice but not WT mice. Our results indicate that MT-null mice are hypersusceptible to the hepatocarcinogenic effects of cisplatin, and poor MT expression may be a predisposing factor for cisplatin-induced secondary tumors after chemotherapy.

Animals↗

Expression and distribution of trihydrophobin 1 in postnatal developing mouse testis.

The human trihydrophobin 1 (TH1) is a highly conserved and widely expressed protein. It is clear that TH1 serves as a new specific negative regulator of A-Raf kinase. In this study, we found that TH1 associated with A-Raf in mouse testis by using coimmunoprecipitation analysis. Then we characterized the gene expression of TH1 in mouse testis and analyzed the changes of TH1 protein during postnatal development. The protein expression of TH1 in mouse testis was further analyzed by immunohistochemistry staining. Strong signals were detected in the seminiferous tubules and the distribution patterns varied with the different ages of postnatal mouse testis. TH1 was distributed in spermatocytes and Sertoli cells at 2 weeks postnatal, and was abundant in spermatogonia at 8 weeks postnatal. Leydig cells were positive to TH1 throughout testicular development. A high expression of TH1 in both Leydig cells and mouse Leydig tumor cells (mLTC-1cells) was found to be concentrated in the cytoplasm. The colocalization of TH1 and A-Raf in mLTC-1 cells or in adult testis was also observable.

Animals↗

Further studies on aberrant gene expression associated with arsenic-induced malignant transformation in rat liver TRL1215 cells.

Chronic arsenic exposure of rat liver epithelial TRL1215 cells induced malignant transformation in a concentration-dependent manner. To further define the molecular events of these arsenic-transformed cells (termed CAsE cells), gene expressions associated with arsenic carcinogenesis or influenced by methylation were examined. Real-time RT-PCR showed that at carcinogenic concentrations (500 nM, and to a less extent 250 nM of arsenite), the expressions of alpha-fetoprotein (AFP), Wilm's tumor protein-1 (WT-1), c-jun, c-myc, H-ras, c-met and hepatocyte growth factor, heme oxygenase-1, superoxide dismutase-1, glutathione-S-transferase-pi and metallothionein-1 (MT) were increased between 3 to 12-fold, while expressions of insulin-like growth factor II (IGF-II) and fibroblast growth factor receptor (FGFR1) were essentially abolished. These changes were not significant at the non-carcinogenic concentration (125 nM), except for IGF-II. The positive cell-cycle regulators cyclin D1 and PCNA were overexpressed in CAsE cells, while the negative regulators p21 and p16 were suppressed. Western-blot confirmed increases in AFP, WT-1, cyclin D1 and decreases in p16 and p21 protein in CAsE cells. The CAsE cells over-expressed MT but the demethylating agent 5-aza-deoxycytidine (5-aza-dC, 2.5 microM, 72 h) stimulated further MT expression. 5-Aza-deoxycytidine restored the loss of expression of p21 in CAsE cells to control levels, but did not restore the expression of p16, IGF-II, or FGFR1, indicating the loss of expression of these genes is due to factors other than DNA methylation changes. Overall, an intricate variety of gene expression changes occur in arsenic-induced malignant transformation of liver cells including oncogene activation and alterations in expression of genes critical to growth regulation.

Animals↗

An evaluation on the efficacy and safety of amlexanox oral adhesive tablets in the treatment of recurrent minor aphthous ulceration in a Chinese cohort: a randomized, double-blind, vehicle-controlled, unparallel multicenter clinical trial.

OBJECTIVE: The objectives of this study were to clinically determine the topical efficacy and safety of amlexanox oral adhesive tablets in the treatment of recurrent minor aphthous ulcerations (MiRAU) in a Chinese cohort. STUDY DESIGN: A randomized, double-blind, vehicle-controlled, unparallel multicenter clinical trial was carried out. The tablets were applied by subjects themselves 4 times a day for 5 days. Four parameters (pain scale, size change, degree of erythema and exudation, and efficacy index) were recorded both before (baseline) and during the trial (on the morning of days 4 and 6). RESULTS: There were 104 and 108 subjects who fulfilled the trial in the amlexanox group and the vehicle-control group, respectively. Group differences for all parameters but degree of erythema and exudation of day 4 were statistically significant both for the day 4 visit and the day 6 visit (P < .05). No systemic side effects were reported. CONCLUSIONS: Amlexanox oral adhesive tablets are effective and safe in reducing aphthous ulcer pain and lesion size, as well as erythema and exudation in this Chinese cohort.

Adhesives↗

Pathophysiological role of the acute inflammatory response during acetaminophen hepatotoxicity.

Neutrophils are recruited into the liver after acetaminophen (AAP) overdose but the pathophysiological relevance of this acute inflammatory response remains unclear. To address this question, we compared the time course of liver injury, hepatic neutrophil accumulation and inflammatory gene mRNA expression for up to 24 h after treatment with 300 mg/kg AAP in C3Heb/FeJ and C57BL/6 mice. Although there was no relevant difference in liver injury (assessed by the increase of plasma alanine aminotransferase activities and the areas of necrosis), the number of neutrophils and the expression of several pro-inflammatory genes (e.g., tumor necrosis factor-alpha, interleukin-1beta and macrophage inflammatory protein-2) was higher in C3Heb/FeJ than in C57BL/6 mice. In contrast, the expression of the anti-inflammatory genes interleukin-10 and heme oxygenase-1 was higher in C57BL/6 mice. Despite substantial hepatic neutrophil accumulation, none of the liver sections from both strains stained positive for hypochlorite-modified proteins, a specific marker for a neutrophil-induced oxidant stress. In addition, treatment with the NADPH oxidase inhibitors diphenyleneiodonium chloride or apocynin or the anti-neutrophil antibody Gr-1 did not protect against AAP hepatotoxicity. Furthermore, although intercellular adhesion molecule-1 (ICAM-1) was previously shown to be important for neutrophil extravasation and tissue injury in several models, ICAM-1-deficient mice were not protected against AAP-mediated liver injury. Together, these data do not support the hypothesis that neutrophils aggravate liver injury induced by AAP overdose.

Acetaminophen↗

Conformational transition between four and five-stranded phenylalanine zippers determined by a local packing interaction.

Alpha-helical coiled coils play a crucial role in mediating specific protein-protein interactions. However, the rules and mechanisms that govern helix-helix association in coiled coils remain incompletely understood. Here we have engineered a seven heptad "Phe-zipper" protein (Phe-14) with phenylalanine residues at all 14 hydrophobic a and d positions, and generated a further variant (Phe-14(M)) in which a single core Phe residue is substituted with Met. Phe-14 forms a discrete alpha-helical pentamer in aqueous solution, while Phe-14(M) folds into a tetrameric helical structure. X-ray crystal structures reveal that in both the tetramer and the pentamer the a and d side-chains interlock in a classical knobs-into-holes packing to produce parallel coiled-coil structures enclosing large tubular cavities. However, the presence of the Met residue in the apolar interface of the tetramer markedly alters its local coiled-coil conformation and superhelical geometry. Thus, short-range interactions involving the Met side-chain serve to preferentially select for tetramer formation, either by inhibiting a nucleation step essential for pentamer folding or by abrogating an intermediate required to form the pentamer. Although specific trigger sequences have not been clearly identified in dimeric coiled coils, higher-order coiled coils, as well as other oligomeric multi-protein complexes, may require such sequences to nucleate and direct their assembly.

Amino Acid Motifs↗

Screening and identification of vascular-endothelial-cell-specific binding peptide in gastric cancer.

Antiangiogenesis therapy has become a hot field in cancer research. Blood vessels of tumor carry specific markers that are usually related to angiogenesis. Study of these heterogeneous molecules in different tumor vessels may be beneficial for promoting antiangiogenic therapy. In this study, we established an in vitro co-culture model of human umbilical vein endothelial cells (HUVECs) and gastric adenocarcinoma cell line SGC7901, screened the peptides binding specifically to the HUVECs co-cultured with gastric cancer cells (Co-HUVECs) using phage display peptides library, and studied the affinity of these peptides to gastric cancer vascular endothelial cells. After four rounds of panning, there was an obvious enrichment for the phages specifically binding to the Co-HUVECs, and the output/input ratio of Co-HUVECs increased about 590-fold (from 0.95x10(-7) to 561.25x10(-7)). Five phage clones (M6, M3, M9, IN12, IN11), which could strongly bind to Co-HUVECs instead of wild-type HUVECs, were characterized by ELISA. In vitro cellular binding assay showed that phage IN11 preferably bound to Co-HUVECs rather than control HUVECs, and the number of the phage IN11 recovered from Co-HUVECs was 5.7- and 16.9-folds, respectively, as much as those from control HUVECs and GES cells. Immunocytochemical and immunohistochemical staining confirmed that phage IN11 could specifically bind to Co-HUVECs as well as vascular endothelial cells in gastric cancer tissue sections. Competitive and inhibitory assay revealed the synthetic peptide GEBP11 (CTKNSYLMC) displayed on phage IN11 could competitively inhibit binding of the phage IN11 to Co-HUVECs. Immunofluorescence microscopy showed that the fluorescence-labeled peptide GEBP11 was located at the membrane and perinuclear cytoplasm of Co-HUVECs. Meanwhile, GEBP11 was found to be able to target the gastric cancer vascular endothelial cells. Therefore, GEBP11 may be a potential candidate for targeted drug delivery in antivascular therapy and diagnosis of gastric cancer.

Amino Acid Sequence↗

beta1-Adrenergic receptor polymorphisms influence the response to metoprolol monotherapy in patients with essential hypertension.

OBJECTIVES: The human beta(1)-adrenergic receptor, an important therapeutic target in cardiovascular diseases, has 2 common functional polymorphisms (Ser49Gly and Gly389Arg). Our study aimed to confirm that beta(1)-adrenergic receptor polymorphisms affect the blood pressure response to metoprolol monotherapy in the Chinese population with hypertension. METHODS: beta(1)-Adrenergic receptor genotype was determined by polymerase chain reaction-restriction fragment length polymorphism assay for 223 patients with essential hypertension. Sixty-one patients with certain beta(1)-adrenergic receptor diplotypes, 18 for 49Ser389Arg/49Ser389Arg, 15 for 49Ser389Arg/49Gly389Arg, 19 for 49Ser389Gly/49Gly389Arg, and 9 for 49Ser389Gly/49Ser389Gly, were selected from those 61 for measurement of the antihypertensive effect of metoprolol. Patients were given 25 mg metoprolol every 12 hours for 4 weeks. Heart rate and blood pressure were measured weekly for the duration of metoprolol therapy. RESULTS: The descent of systolic blood pressure after metoprolol administration was significantly different among genotype groups (10.4% +/- 4.0%, 2.8% +/- 4.7%, and 1.1% +/- 1.5% for Arg389Arg, Gly389Arg, and Gly389Gly patients, respectively; P < .001). We also found a similar difference in changes of diastolic blood pressure (6.1% +/- 4.3%, 2.2% +/- 4.2%, and 0.9% +/- 4.0%, respectively; P < .001) and mean arterial pressure (8.1% +/- 3.5%, 2.5% +/- 3.0%, and 1.0% +/- 2.5%, respectively; P > .001) for Arg389Arg, Gly389Arg, and Gly389Gly patients. Ser49Gly variance exhibited a smaller contribution to the antihypertensive effect of metoprolol. Systolic blood pressure decreased significantly in Ser49 homozygous patients compared with Ser49Gly patients (8.4% +/- 3.2% versus 5.3% +/- 5.2%, P = .047). There was a highly significant relationship between diplotype and blood pressure during treatment. Systolic blood pressure significantly decreased in 49Ser389Arg/49Ser389Arg (12.0% +/- 3.8%, P < .001) and 49Ser389Arg/49Gly389Arg (8.4% +/- 5.5%, P < .001) patients, with the decrease in the former being more pronounced (P = .023). We also found a significant decrease in diastolic blood pressure (6.5% +/- 4.7% versus 5.7% +/- 3.2%, respectively; both P < .001) and mean arterial pressure (8.8% +/- 3.2% versus 6.9% +/- 3.7%, respectively; both P < .001) in 49Ser389Arg/49Ser389Arg and 49Ser389Arg/49Gly389Arg patients. However, blood pressure did not change significantly in 49Ser389Gly/49Gly389Arg and 49Ser389Gly/49Ser389Gly patients (all P > .05). CONCLUSIONS: beta(1)-Adrenergic receptor polymorphism was associated with different blood pressure responses to metoprolol therapy in patients with essential hypertension. 49Ser389Arg/49Ser389Arg and 49Ser389Arg/49Gly389Arg patients were good responders to metoprolol therapy; 49Ser389Arg/49Ser389Arg patients had a larger systolic blood pressure reduction than 49Ser389Arg/49Gly389Arg patients did. 49Ser389Gly/49Gly389Arg and 49Ser389Gly/49Ser389Gly patients were nonresponders to metoprolol antihypertensive therapy.

Adrenergic beta-Antagonists↗