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Hong Lu

Publications and source records attributed to Hong Lu.

At least 73 records · Page 4Linked to original sources
PubMed2005

Construction of a novel kind of expression plasmid by homologous recombination in Saccharomyces cerevisiae.

Based on a previously used plasmid pHC11, a new plasmid pHC11R was constructed. Cutting plasmid pHC11R with proper restriction enzymes, the resulting larger DNA fragment pHC11R' was co-transformed with a PCR amplified expression cassette of human IFNalpha2b into yeast. By means of the homologous sequences at both ends of two DNA fragments, a novel expression plasmid pHC11R-IFNalpha2b was formed via homologous recombination in the yeast. Compared with pHC11-IFNalpha2b, the expression plasmid pHC11R-IFNalpha2b was smaller in size and in absence of antibiotic resistant gene. The stability and copy number of pHC11R-IFNalpha2b were greatly increased and the expression level of heterologous protein was improved. As the derivatives of pHC11R, a series of recombination expression vectors pHRs containing different combination of expression elements were developed. This led to a rapid and powerful method for cloning and expressing of different genes in yeast.

Escherichia coli↗
PubMed2005

[Treatment of lower limb ischemia with combination of traditional Chinese medicine and transplantation of autologous bone marrow mononuclear cells: a report of 23 cases].

OBJECTIVE: To evaluate the therapeutic effect of transplantation of autologous bone marrow mononuclear cells combined with traditional Chinese medicine for the treatment of limb ischemia. METHODS: Twenty-three patients with limb ischemia were treated. G-CSF was used to stimulate the bone marrow. The mononuclear cells were separated from the aspirated bone marrow fluid in the stem cell studio. The cell amount was above 1x10(9). The transplantation was performed by the way of intra-muscular multi-injection. Traditional Chinese medicine for replenishing qi to activate blood was prescribed from the first day after operation. The pain, poikilothermia, ulcer or necrosis and ankle/brachial index (ABI) of the ischemic limb were evaluated before and after the treatment. RESULTS: The pain score and poikilothermia score decreased one month after the transplantation, with distinct differences as compared with the scores before the treatment (P<0.05). The ABI increased gradually after the treatment, and one month after the treatment, it was 0.15 higher than that before the treatment. CONCLUSION: Transplantation of autologous bone marrow mononuclear cells combined with traditional Chinese medicine can decrease the symptoms and signs of severe lower limb ischemia effectively, and improve the circulation of the ischemic area.

Adult↗
PubMed2005

Cutoff point separating affected and unaffected familial hypercholesterolemic patients validated by LDL-receptor gene mutants.

Familial hypercholesterolemia (FH) results from low-density lipoprotein (LDL) receptor gene mutations. Heterozygotes have twice normal LDL-cholesterol concentrations in early childhood, and experience early myocardial infarction. We demonstrated bimodal cholesterol frequency distributions, independently confirming existence of an identifiable hypercholesterolemic subpopulation. We assayed blood lipids in 181 FH patients genetically diagnosed and 100 unaffected relatives. Receiver operating characteristics curves were constructed. Total cholesterol and LDL-cholesterol concentrations showed bimodality. A total cholesterol cutoff of 225 mg/dl produced results agreeing with DNA testing (specificity, 98.5%; sensitivity, 99.4%). An LDL-cholesterol cutoff of 161-163 mg/dl produced 98.5% specificity and 98.3% sensitivity. Areas under curves were 0.9826 +/- 0.0058 for total cholesterol, and 0.9852 +/- 0.0043 for LDL-cholesterol. In conclusion, we define total cholesterol and LDL-cholesterol levels of 225 and 160 mg/dl, respectively, as cutoff points of normal subjects and FH patients.

Heterozygote↗
PubMed2005

A novel component of the ubiquitin pathway, ubiquitin carboxyl extension protein 1 is overexpressed in prostate cancer.

Prostate cancer is among the most common tumors in industrialized nations. However, little is known about the molecular events underlying its development. In the present study we used suppressive subtraction hybridization (SSH) in combination with laser-assisted microdissection in order to compare gene expression between prostate carcinoma and the normal prostate proper. Both are mixed tissues which consist of an epithelial and a stromal compartment. We first compared mRNA (cDNA) expression by SSH and then used real-time quantitative RT-PCR analysis of microdissected tissue probes in order to verify differential expression of subtracted cDNA clones. We also used differentially expressed cDNAs for the synthesis of radiolabelled riboprobes in order to attribute differential expression to specific cell types in tissue sections by in situ hybridization. Using this approach we found an up-regulation of ubiquitin carboxyl extension protein 1 (UBCEP-1) mRNA in prostate carcinoma cells compared to the normal glandular epithelium of the prostate proper. UBCEP-1 mediated ubiquitin chain elongation may promote prostate carcinoma development by increasing via the proteasome pathway the degradation of proteins which are involved in growth inhibition or apoptosis.

Aged↗
PubMed2005

[Determination of relative error of pressure-broadening linewidth for the experimentally indistinguishable overlapped spectral lines with Voigt profile].

The simulation and fitting of the overlapped spectral lines with Voigt profile were presented in this paper. The relative errors epsilon of the fitted pressure-broadening linewidth when taking the overlapped spectral line as one spectrum were discussed in detail. The relationship between such error and the two spectral lines center distance deltav0, and theoretical pressure-broadening linewidth deltav(L)0 were analyzed. Epsilon is found to be very large and the relationship between epsilon and deltav0, deltav(L)0 is very complicated when the value of pressure-broadening linewidth is considerably less than that of Dopplerian one deltavD. When deltav(L)0 is comparative to deltaVD the relationship between epsilon and deltav0 is close to the smooth two-order polynomial curve. However, the slop of this curve is negative while deltav(L)0 is smaller than deltavD and is positive when larger. Generally, epsilon decreases with the increase of proportion of deltav(l)0 to the whole spectral linewidth. All the above conclusion and corresponding data are the significant reference to determine the precise pressure-broadening coefficient from the experimentally indistinguishable overlapped spectrum, as well as to correct the fitted pressure-broadening linewidth.

Algorithms↗
PubMed2005

Biodegradation of azo dyes by genetically engineered azoreductase.

A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides AS1.1737. The enzyme, with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.

Azo Compounds↗
PubMed2005

Cellular retinoic acid-binding protein 2 is down-regulated in prostate cancer.

Prostate cancer is among the most frequent tumours in industrialized nations and many questions remain open concerning the molecular events underlying its development and progression. In the present study we have combined cDNA array hybridization to laser-assisted microdissection (LAM) in order to investigate differences in gene expression between epithelial and stromal cells of prostate cancer and normal peripheral prostate tissue. Results have been verified for selected candidate genes by quantitative real-time RT-PCR. Using this approach and immunohistochemistry we could demonstrate a down-regulation of cellular retinoic acid binding protein 2 (CRABP2) mRNA and protein in carcinoma cells compared to normal glandular cells. CRABP2 is a main regulator of anti-carcinogenic activities of retinoic acid and may become a novel diagnostic marker and experimental therapeutic tool for prostate cancer. In addition, results of cDNA array hybridization suggest an up-regulation of 34 further genes and a down-regulation of 6 genes in cancer tissues compared to normal peripheral prostate tissues. Several of these genes have already been reported to be associated with carcinogenesis in organs such as the prostate.

Aged↗
PubMed2005

[Inhibition of salicylate on potassium channels in rat inferior colliculus neurons].

OBJECTIVE: To understand what role of the transient outward potassium channels and the delayed rectifier potassium channels play in the mechanism of salicylate-induced tinnitus. METHODS: The effects of salicylate on the transient outward potassium channels and the delayed rectifier potassium channels in freshly dissociated inferior colliculus neurons of rats were studied, using the whole-cell voltage clamp method. RESULTS: Salicylate blocked the transient outward potassium current (I(K(A and the delayed rectifier potassium current (I(K(DR in concentration-dependent manner (0.1-1 mmol/L). The IC50 values for the blocking action of salicylate on I(K(A)) and I(K(DR)) were 2.27 and 0.80 mmol/L, respectively. At a concentration of 1 mmol/L, salicylate did not shift the activation and inactivation curves of I(K(A)), but significantly shifted the activation and inactivation curves of I(K(DR)) negatively by approximately 11 mV and 24 mV. CONCLUSIONS: Salicylate inhibits both I(K(A)) and I(K(DR)) in rat inferior colliculus neurons but only significantly affects the activation and inactivation kinetics of I(K(DR)). Effects of I(K(A)) and I(K(DR)), especially I(K(DR)), by salicylate may play an important role in salicylate-induced tinnitus.

Animals↗
PubMed2004

Hypercholesterolemia stimulates angiotensin peptide synthesis and contributes to atherosclerosis through the AT1A receptor.

BACKGROUND: Hypercholesterolemia-induced atherosclerosis is attenuated by either pharmacological antagonism of AT1 receptors or AT1A receptor deficiency. However, the mechanism underlying the pronounced responses to angiotensin II (Ang II) antagonism has not been determined. We hypothesized that hypercholesterolemia stimulates the production of angiotensin peptides to provide a rationale for the profound effect of AT1A receptor deficiency on atherogenesis. METHODS AND RESULTS: Atherosclerotic lesions were analyzed in LDL receptor-deficient mice. Immunocytochemical analysis demonstrated that atherosclerotic lesions contained all the components of the conventional pathway for Ang II synthesis. AT1A receptor deficiency caused a marked decrease in atherosclerotic lesion size in both the aortic root and arch of male and female mice, without a discernible effect on composition. AT1A receptor deficiency-induced reductions in atherosclerosis were independent of systolic blood pressure and measurements of oxidation and chemoattractants. Aortic AT2 receptor mRNA expression was not altered in AT1A receptor-deficient mice, and AT2 receptor deficiency had no effect on lesion area or cellular composition. Hypercholesterolemia greatly augmented the systemic renin-angiotensin system, as demonstrated by large increases in plasma concentrations of angiotensinogen and angiotensin peptides (Ang II, III, IV, and 4-8). These increases were ablated in hypercholesterolemic AT1A receptor-deficient mice. CONCLUSIONS: AT1A receptor deficiency had a striking effect in reducing hypercholesterolemia-induced atherosclerosis in LDL receptor-negative mice. Hypercholesterolemia was associated with increased systemic angiotensinogen and angiotensin peptides, which were reduced in AT1A receptor-deficient mice. These results demonstrate that hypercholesterolemia-induced stimulation of angiotensin peptide production provides a basis for the marked effect of AT1A receptor deficiency in reducing atherosclerosis.

Amino Acid Sequence↗
PubMed2004

Proteomic fingerprints for potential application to early diagnosis of severe acute respiratory syndrome.

BACKGROUND: Definitive early-stage diagnosis of severe acute respiratory syndrome (SARS) is important despite the number of laboratory tests that have been developed to complement clinical features and epidemiologic data in case definition. Pathologic changes in response to viral infection might be reflected in proteomic patterns in sera of SARS patients. METHODS: We developed a mass spectrometric decision tree classification algorithm using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Serum samples were grouped into acute SARS (n = 74; <7 days after onset of fever) and non-SARS [n = 1067; fever and influenza A (n = 203), pneumonia (n = 176); lung cancer (n = 29); and healthy controls (n = 659)] cohorts. Diluted samples were applied to WCX-2 ProteinChip arrays (Ciphergen), and the bound proteins were assessed on a ProteinChip Reader (Model PBS II). Bioinformatic calculations were performed with Biomarker Wizard software 3.1.1 (Ciphergen). RESULTS: The discriminatory classifier with a panel of four biomarkers determined in the training set could precisely detect 36 of 37 (sensitivity, 97.3%) acute SARS and 987 of 993 (specificity, 99.4%) non-SARS samples. More importantly, this classifier accurately distinguished acute SARS from fever and influenza with 100% specificity (187 of 187). CONCLUSIONS: This method is suitable for preliminary assessment of SARS and could potentially serve as a useful tool for early diagnosis.

Adolescent↗
PubMed2004

Effect of 2-(3-carboxy-1-oxopropyl) amino-2-deoxy-D-glucose on human esophageal cancer cell line.

AIM: To determine whether 2-(3-carboxy-1-oxopropy1) amino-2-deoxy-D-glucose (COPADG), a derivative of D-amino-glucose, inhibited the growth of human esophageal cancer cell line Eca-109. METHODS: Effects of COPADG on Eca-109 cells cultured in RPMI 1640 medium were examined by a tetrazolium-based colorimetric assay (MTT assay). RESULTS: COPADG inhibited the growth of Eca-109 cells in a dose- and time-dependent manner; the maximum inhibition rate was 83.75%. CONCLUSION: COPADG can directly inhibit the proliferation of Eca-109 cells, which may serve as the experimental evidence for development of new drugs for esophageal cancer therapy.

Antineoplastic Agents↗
PubMed2004

Antitumor activity of methoxymorpholinyl doxorubicin: potentiation by cytochrome P450 3A metabolism.

Methoxymorpholinyl doxorubicin (MMDX) is a novel liver cytochrome P450 (P450)-activated anticancer prodrug whose toxicity toward cultured tumor cells can be potentiated up to 100-fold by incubation with liver microsomes and NADPH. In the present study, a panel of human liver microsomes activated MMDX with potentiation ratios directly correlated to the CYP3A-dependent testosterone 6beta-hydroxylase activity of each liver sample. Microsome-activated MMDX exhibited nanomolar IC(50) values in growth-inhibition assays of human tumor cell lines representing multiple tissues of origin: lung (A549 cells), brain (U251 cells), colon (LS180 cells), and breast (MCF-7 cells). Analysis of individual cDNA-expressed CYP3A enzymes revealed that rat CYP3A1 and human CYP3A4 activated MMDX more efficiently than rat CYP3A2 and that human P450s 3A5 and 3A7 displayed little or no activity. MMDX cytotoxicity was substantially increased in Chinese hamster ovary cells after stable expression of CYP3A4 in combination with P450 reductase. CYP3A activation of MMDX abolished the parent drug's residual cross-resistance in a doxorubicin-resistant MCF-7 cell line that overexpresses P-glycoprotein. CYP3A-activated MMDX displayed a comparatively high intrinsic stability, with a t(1/2) of approximately 5.5 h at 37 degrees C. MMDX was rapidly activated by CYP3A at low ( approximately 1-5 nM) prodrug concentrations, with 100% tumor cell kill obtained after as short as a 2-h exposure to the activated metabolite. These findings demonstrate that MMDX can be activated by CYP3A metabolism to a potent, long-lived, and cell-permeable cytotoxic metabolite and suggest that this anthracycline prodrug may be used in combination with CYP3A4 in a P450 prodrug activation-based gene therapy for cancer treatment.

Animals↗
PubMed2004

Tissue distribution of concentrative and equilibrative nucleoside transporters in male and female rats and mice.

Concentrative nucleoside transporters (Cnts) and equilibrative nucleoside transporters (Ents) have essential physiological functions and are important in disposition of anticancer and antiviral nucleoside analogs. Information on tissue distribution of Cnts and Ents in rodents is sparse. Thus, the present study aimed to determine the distribution of Cnt1-3 and Ent1-3 transcripts in 19 tissues of Sprague-Dawley rats and C57BL/6 mice of both genders. These six transcripts were quantified using the branched DNA signal amplification assay. Cnt1 transcripts were highest in small intestine, followed by kidney and testes, with similar expression in both species. Cnt2 mRNA was expressed highest in the small intestine of both rats and mice, intermediate in liver of rats but not in mice, and lower in thymus and spleen of both species. Cnt3 mRNA has marked species differences, with the highest expression in lung of rats but uterus of mice. Ent1 mRNA was most highly expressed in testes and lung of both species. Ent1 mRNA was highly expressed in liver and pituitary of mice, but not in rats. Ent2 mRNA was highly expressed in testes and brain of both species. Ent3 mRNA was highest in kidney, followed by testes, in both species. Significant gender differences were observed in kidney (mouse) and heart (rat). These studies demonstrate that in general, tissue distribution of Cnt and Ent is similar in rats and mice. However, a few important species and gender differences do exist, which could be responsible for related differences in efficacy and toxicity of substrates for these transporters.

Animals↗
PubMed2004

Synthesis and anti-HIV-1 activity of 4-[4-(4,6-bisphenylamino-triazin-2-ylamino)-5-methoxy-2-methylphenylazo]-5-hydroxynaphthalene-2,7-disulfonic acid and its derivatives.

A structure-based design approach has been used to optimize a lead HIV-1 entry inhibitor targeted to the envelope glycoprotein gp41. The docking study on this lead compound revealed important structural requirements that need to be preserved as well as structural non-requirements that could be eliminated to substantially reduce the molecular size of the lead compound. Based on the results from docking study, a limited number of analogues were designed and synthesized. This approach yielded a new analogue (compound 4) that retained the anti-HIV-1 activity with reduced molecular size approaching towards more drug-like character.

Anti-HIV Agents↗
PubMed2004

Urinary and plasma levels of resveratrol and quercetin in humans, mice, and rats after ingestion of pure compounds and grape juice.

The present study investigates the bioavailability of resveratrol and quercetin in humans, mice, and rats after oral ingestion of grape juice preparations or pure aglycones. Oral administration of resveratrol and quercetin to humans yielded detectable levels of resveratrol, quercetin, and their derivatives in the plasma and urine. Urinary levels of resveratrol, quercetin, and their metabolites were observed in human subjects receiving 600 and 1200 mL of grape juice, whereas quercetin metabolites were identified in urine samples even after receiving 200 mL of grape juice. The cumulative amounts of resveratrol and quercetin excreted in the urine of mice receiving concentrated grape juice for 4 days were 2.3 and 0.7% of the ingested doses, respectively. After i.g. administration of resveratrol to rats (2 mg/kg), up to 1.2 microM resveratrol was observed in the plasma. The study demonstrates that the glycoside forms of resveratrol and quercetin in grape juice are absorbed to a lesser extent than the aglycones.

Animals↗