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Biomedical subjects

B Huang

Publications and source records attributed to B Huang.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Production and detection of monoclonal anti-idiotype antibodies against Vibrio anguillarum].

Vibrio anguillarum is the pathogenic bacteria of Vibriosis, which is an infectious disease found in various fish species. Seven monoclonal anti-idiotype antibodies(mAb2) were raised against mAb1 4A6. Identification of subgroup showed that 1H5, 1D1, 2B12 and 2F12 belonged to IgG2b, 2H12 and 1H12 to IgG2a and 1E10 to IgG3. The titers of these mAb2 ascites were 1 x 10(-4)-1 x 10(-6). The capacity of the mAb2 to inhibit the binding between mAb1 and antigen was investigated with the competitive inhibition ELISA. The results showed that 1D1, 1E10 1H5 and 2H12 mAb2 were able to inhibit this binding. Another experiment demonstrated that four mAb2(1D1, 1E10, 1H5 and 2H12) might induce Balb/c mice to produce Ab3 and these Ab3 competed the same antigen epitopes with Ab1. These results indicate that mAb2(1D1, 1E10, 1H5 and 2H12) are likely to represent internal image of antigen and belong to Ab2 beta. They might be employed to induce antibodies against pathogenic epitopes of V. anguillarum in vivo so as to gave the safe and effective vaccine.

Animals↗
PubMed2001

The preliminary experimental study of induced differentiation of embryonic stem cells into corneal epithelial cells.

PURPOSE: To study preliminarily induced differentiation of embryonic stem cells into corneal epithelial cells in vitro. METHODS: Murine embryonic stem cells were co-cultured with Rabbit limbal corneal epithelial cells in Transwell system to induce differentiation. Mophological and immunohistochemical examination were implemented. RESULTS: The induced cells from embryonic stem cells have an epithelial appearance. The cells formed a network and were confluent into film gradually after being co-cultured with rabbit limbal corneal epithelial cells for 24-96 hours. The cells ranged mosaic structure and localized together with clear rim. Most of the cells showed polygonal appearance. Transmission electron microscope showed lots of microvilli on the surface of induced cells and tight junctions between them. These epithelial-like cells expressed the corneal epithelial cell specific marker cytokeratin3/cytokeratin12. CONCLUSION: The potential mechanism of the differentiation of murine embryonic stem cells into corneal epithelial cells induced by limbal corneal epithelial cell-derived inducing activity is to be further verified.

Animals↗
PubMed2001

[Clinical and experimental study on treatment of childhood hyperkinetic syndrome with yizhidan].

OBJECTIVE: To observe the clinical effect of Yizhidan (YZD) in treating childhood hyperkinetic syndrome (CHS) and its mechanism. METHODS: Random single blind method was used in clinical study to observe the clinical effect of YZD and compared with that of Ritalin. The dysmnesia model animal was used to observe the effect of YZD on learning memory function and cerebral monoamine neurotransmitter content. RESULTS: The markedly effective rate and the total effective rate of YZD were 45.56% and 87.78%, which were similar to those of Ritalin (53.33% and 86.67%). The Conners index lowered in both groups, showing insignificant difference (P > 0.05). Experimental observation showed that YZD could significantly improve the soft neurologic signs and abnormal encephalogram with less side-effects in comparing with Ritalin (P < 0.05). Moreover, YZD could obviously improve the learning memory disturbance induced by scopolamine, sodium nitrite and ethanol, and significantly increased the contents of DA in cerebral tissue, as compared with that of the control group, the difference was significant (P < 0.01). It also showed effect on DOPAC, NE, HVA, 5-HT and 5-HIAA of mice in certain degree. CONCLUSION: YZD is an effective drug in treating CHS, its mechanism might be probably related to the improvement of the memory and the enhancement of DA receptor in cerebral tissue.

Adrenergic Agents↗
PubMed2001

[RP-HPLC method for determination of protopine in plasma and pharmacokinetics in rats].

AIM: To develop a reversed phase high performance liquid chromatographic method (RP-HPLC) for determination of protopine (Pro) in rat plasma and to investigate the pharmacokinetics of Pro in rats. METHODS: The column was packed with 5 microns C18. The mobile phase (pH 5.6) was a mixture of methanol-water-10% acetic acid (80:20:2). After twice extracted with ether under basic condition, and reextracted with 0.02 mol.L-1 sulfuric acid, protopine in the plasma samples was isolated well. The content of protopine in the plasma sample was measured by UV detector at 285 nm. RESULTS: The lowest limit of detection was 50 ng.mL-1. The intraday and interday precisions were 1.5%-3.0% and 2.1%-6.2%, respectively. The mean recovery was 80.6%-97.6%. A good linear relationship between the peak height and the concentration of protopine in rat plasma was observed. The pharmacokinetics of protopine had been investigated in rats after intravenous administration 10 mg.kg-1. The concentration-time curve of protopine in rat was confirmed to two-compartment open model. The T1/2 alpha, T1/2 beta, Ke, CL, Vd were 0.05 h, 1.85 h, 1.52 h, 6.41 L.h-1 and 17.27 L, respectively. CONCLUSION: This method is suitable for studies on pharmacokinetics of protopine.

Analgesics, Opioid↗
PubMed2001

[Karyotype analysis of Echinocodon lobophyllus].

The paper reported the chromosome number, karyotype and chromosome volume of Echinocodon lobophyllus. The normal diploid was 2n = 16, karyotype formula based on Levan's publication was K(2n) = 16= 14m + 2Sm. According to the method of S. R. Kuo, the chromosome relative length was 2n = 16 = 10M2 + 6M1, which belong to "1A" type according to the Stebbins' karyotype classification. The AS.K% was 57.24% from Arano's method. The total volume of chromosome groups was 1.16 microm3.

Campanulaceae↗
PubMed2000

Immunoblot assays using recombinant antigens for the detection of Mycoplasma hyopneumoniae antibodies.

The 36kDa L-lactate dehydrogenase (LDH) and a 29kDa partial fragment of an ABC transporter ATP-binding protein analogue/multidrug resistance protein homologue (PR2) of Mycoplasma hyopneumoniae were tested for their potential as diagnostic antigens. Recombinant LDH was genetically engineered to contain six histidine residues at its C-terminal end, expressed in Escherichia coli and purified to a high degree using Ni(2+)-chelate affinity chromatography. A partial 262 amino acid segment representing the C-terminal end of the PR2 protein was cloned as a glutathione S-transferase (GST) fusion protein, expressed in E. coli and purified by urea extraction. Purified recombinant LDH-6xHis and PR2-GST were then reacted with pig sera in immunoblot assays. Our immunoblots showed that both proteins detected anti-M. hyopneumoniae antibodies in field and experimentally infected pig sera but not in any of the SPF control sera. The two proteins were specific for M. hyopneumoniae as they did not react with sera of pigs infected with the closely related Mycoplasma flocculare and Mycoplasma hyorhinis which are frequently isolated in pigs but are not of particular concern.

ATP-Binding Cassette Transporters↗
PubMed2000

Lansoprazole compared with ranitidine for the treatment of nonerosive gastroesophageal reflux disease.

BACKGROUND: Traditionally, proton pump inhibitors are used primarily for patients with esophagitis. However, patients with nonerosive reflux disease may also benefit from these powerful medications. OBJECTIVE: To compare the safety and symptom relief efficacy of lansoprazole with ranitidine therapy and with placebo. METHODS: In 2 randomized, double-blind, multicenter trials of 901 patients with symptomatic reflux disease, which was confirmed by endoscopy to be nonerosive, received lansoprazole, 15 or 30 mg once daily; ranitidine, 150 mg twice daily; or placebo for 8 weeks. RESULTS: Analysis of daily diary data during the first 4 weeks and for the entire 8 weeks of treatment revealed that patients who were treated with either dosage of lansoprazole reported significantly (P<.05) lower percentages of days and nights with heartburn, less pain severity of both day and night heartburn, fewer days of antacid use, and smaller amounts of antacid use compared with patients who were treated with ranitidine or placebo. The incidence of possible or probable treatment-related adverse reactions was comparable among the treatment groups; abdominal pain and diarrhea were the most commonly reported adverse events. No statistically significant differences were noted between treatment groups in laboratory analyses. CONCLUSION: Lansoprazole therapy is more effective than standard dosages of ranitidine or placebo in relieving symptoms in patients with endoscopically confirmed non-erosive reflux esophagitis.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Superiority of lansoprazole vs ranitidine in healing nonsteroidal anti-inflammatory drug-associated gastric ulcers: results of a double-blind, randomized, multicenter study. NSAID-Associated Gastric Ulcer Study Group.

BACKGROUND: The usefulness of nonsteroidal anti-inflammatory drugs (NSAIDs) is limited by adverse gastrointestinal tract events. OBJECTIVE: To identify the optimal antisecretory therapy for healing of gastric ulcer in patients using NSAIDs and the impact of concurrent Helicobacter pylori infection on ulcer healing. DESIGN: Prospective, double-blind, multicenter, parallel-group study. SETTING: Gastroenterology practices in ambulatory and referral center settings. PATIENTS: Three hundred fifty-three patients with an active, nonmalignant gastric ulcer at least 5 mm in diameter confirmed by endoscopy and biopsy and who continued to receive stable doses of NSAIDs. INTERVENTION: Patients were randomized to receive ranitidine hydrochloride, 150 mg twice daily, or lansoprazole, 15 mg or 30 mg once daily, for 8 weeks. MEASUREMENTS: Healing was assessed by endoscopy at 4 and 8 weeks in an intent-to-treat population. Helicobacter pylori status was assessed by histological examination. RESULTS: After 8 weeks of treatment, healing was observed in 61 (53%) of 115, 81 (69%) of 118, and 85 (73%) of 117 patients receiving ranitidine lansoprazole, 15 mg, and lansoprazole, 30 mg, respectively (P<.05 for ranitidine vs both lansoprazole doses; 95% confidence interval, 3.2-28.0 for ranitidine vs lansoprazole, 15 mg, and 7.4-31.8 for ranitidine vs lansoprazole, 30 mg). The gastric ulcer healing rates were similar between H pylori-infected and -noninfected patients, with a statistically significant increase with the use of lansoprazole vs ranitidine. CONCLUSIONS: In patients who require continuous treatment with NSAIDs, lansoprazole is superior to ranitidine for healing of NSAID-associated gastric ulcers. Healing is not delayed by the presence of H pylori infection.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Serum lipid effects of a high-monounsaturated fat diet based on macadamia nuts.

BACKGROUND: Recent studies have identified potential beneficial effects of eating nuts, most of which have substantial amounts of monounsaturated fats. Macadamia nuts are 75% fat by weight, 80% of which is monounsaturated. OBJECTIVE: To examine variations in serum lipid levels in response to a high-monounsaturated fat diet based on macadamia nuts. METHODS: A randomized crossover trial of three 30-day diets was conducted in 30 volunteers aged 18 to 53 years from a free-living population. Each was fed a "typical American" diet high in saturated fat (37% energy from fat); an American Heart Association Step 1 diet (30% energy from fat); and a macadamia nut-based monounsaturated fat diet (37% energy from fat) in random order. Serum total cholesterol, high-density lipoprotein cholesterol, and triglyceride levels were measured. RESULTS: Mean total cholesterol level after the typical American diet was 5.20 mmol/L (201 mg/dL). After the Step 1 diet and the macadamia nut diet, total cholesterol level was 4.99 mmol/L (193 mg/dL) and 4.95 mmol/L (191 mg/dL), respectively. Low-density lipoprotein cholesterol level was 3.37 mmol/L (130 mg/dL) (typical diet), 3.21 mmol/L (124 mg/dL) (Step 1 diet), and 3.22 mmol/L (125 mg/dL) (macadamia nut diet). High-density lipoprotein cholesterol level was 1.43 mmol/L (55 mg/dL) (typical), 1.34 mmol/L (52 mg/dL) (Step 1), and 1.37 mmol/L (53 mg/dL) (macadamia nut). Lipid values after the Step 1 and macadamia nut diets were significantly different from those after the typical diet (P<.05). CONCLUSIONS: The macadamia nut-based diet high in monounsaturated fat and the moderately low-fat diet both had potentially beneficial effects on cholesterol and low-density lipoprotein cholesterol levels when compared with a typical American diet.

Adolescent↗
PubMed2000

Synthesis and structure of intramolecularly hydrogen bonded dendrons

[reaction: see text] A convenient synthesis of monodendrons whose conformation is restricted through the intervention of intramolecular hydrogen bonding and repulsive electrostatic interactions is described. X-ray crystal structure analysis of the second generation dendron shows the presence of a propeller-type secondary structure and indicates that the dendrons have assembled into a symmetrically interdigitated dimer in the solid state. 1H NMR and IR spectral data are in agreement with the presence of intramolecular hydrogen bonding between the amides and the pyridine N throughout the dendron structure in solution.

Journal Article↗
PubMed2000

[K-ras gene mutations of asbestos and welding-fumes related human lung cancer].

UNLABELLED: To investigate the K-ras gene mutations in asbestos and welding-fumes related human lung cancer (hLC), comparing with the mutational spectrum of K-ras gene in non-occupational hLC, 8 cases of non-occupational hLC, 9 cases of asbestos-related hLC and 4 cases of welding-fumes related hLC were collected. The techniques of genomic DNA extraction, nested-polymerase chain reaction (PCR), polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and DNA direct sequencing were employed. THE RESULTS: showed the mutation frequencies of K-ras gene were 25% in non-occupational hLC and welding-fumes related hLC, whereas 44.4% in asbestos-related hLC. Mutations mainly occurred in codons 12 and 15. A mutation of codon 13 was detected in welding-fumes related hLC. The type of base substitution was principally G-->T transversion in non-occupational hLC, whereas mainly G-->A transition in asbestos and welding-fumes related hLC. THE RESULTS suggested there were obvious differences of K-ras gene mutations among non-occupational hLC, asbestos and silica related hLC. Therefore, different mechanisms of carcinogenesis were implicated among them. However, no speific spectrum of K-ras gene mutation can be derived from welding-fumes related hLC because of the limitation of samples.

Asbestos↗
PubMed2000

The regulatory effects of protein kinase C on the proliferation of cultured human low-passage meningioma cells.

The potential role of the protein kinase C (PKC)-mediated signal transduction pathways in growth regulation was evaluated and the effects and the possible mechanism of PKC inhibitor on low-passage human meningioma cells in vitro investigated. Freshly resected meningiomas obtained from the operation were placed into cell cultures. Cells from early-passage were used for the following experiments. The numbers of the cultured meningioma cells were counted to evaluate the effect of the PKC inhibitor staurosporine on proliferation of meningioma cells. The basal phosphatidylinositol (PI) turnover rate and the inhibitory rate of starosporine on the proliferation of the meningioma cells were detected. It was found that the proliferation of the low-passage human meningioma cells was inhibited by staurosporine in a dose-dependent manner. The inhibitory rate of staurosporine was positively correlated with the basal PI turnover rate (r = 0.58, P < 0.01). It was suggested that PKC-mediated signal pathway is involved in the proliferation of the low-passage human meningioma cells. The procedure that PKC regulated the proliferation of human meningioma cells is a complex procedure. It is necessary to make more research in order to explore a non-operation therapy or an adjuvant therapy.

Cell Division↗
PubMed2000

Construction of eukaryotic expressing vector pCH503 of CH50 and its chemotaxis and anti-tumor function by expression in vivo in mice.

An eukaryotic expressing vector that expresses CH50, a recombinant polypeptide of human fibronectin, in mice was constructed, and its chemotactic and anti-tumor function by in vivo gene transfection was investigated. The plasmid was constructed by recombination techniques. The cDNA fragment coding CH50 polypeptide from a prokaryotic expressing vector of CH50 was ligated with 5'-terminal noncoding region and coding region of signal peptide of mouse IFN-gamma cDNA at 5' side and 3'-terminal noncoden region of human FN cDNA at 3' side. The recombinant cDNA was inserted into plasmid pREP8. The resulted expressing plasmid was designated as pCH503. The macrophages transfected with pCH503 in vivo and cultured in vitro could produce CH50. The expressed product was identified by heparin-affinity chromatography and SDS-PAGE. By counting and Giemsa-staining of coeliac cells and histotomy and staining of muscle tissue, the chemotaxis on immune cells was observed after transfection of pCH503 either in peritoneal cavity or in muscle. The inhibition of gene transfection of pCH503 on melanoma was observed in mice. The number of melanoma nodes in mice was reduced by 50%-60% after coeliac transfection with pCH503. The pCH503, an eukaryotic expressing vector of CH50, can express in vivo in mice. The transfection of pCH503 in vivo has the chemotaxis on immune cells and can inhibit the formation of tumor nodes, suggesting that plasmid pCH503 is potentially useful in combined treatment of tumor.

Animals↗
PubMed2000

Reexpression of T-type Ca2+ channel gene and current in post-infarction remodeled rat left ventricle.

OBJECTIVE: T-type Ca2+ currents (I(Ca-T)) are present in neonatal rat myocytes but is not detected in adult ventricular myocytes. The present study was designed to investigate the expression of the T-type Ca2+ channel gene and current in post-infarction remodeled hypertrophied rat left ventricle (LV). METHODS: We compared the expression of T-type Ca2+ channel gene alpha-1G in neonatal rat LV, in adult sham-operated LV and remodeled hypertrophied LV 3 to 4 weeks post-myocardial infarction (MI) using RNase protection assay (RPA). The cDNA fragment of alpha-1G used in RPA was obtained from poorly conserved region of recently published T-type Ca2+ channel coding sequence of rat by RT-PCR. The fragment was verified by restriction enzyme digestion and sequencing. The presence of I(Ca-T) in LV of sham and post-MI rats was examined using patch-clamp techniques. In the presence of K+-free, Na+-free external solution, I(Ca-T) was separated from I(Ca-L) by different holding potentials (HP). I(Ca-T) was also recorded during depolarization to -40 mV from a HP of -80 mV with NaCl in external solution and I(Na) suppressed by 100 microM tetrodotoxin (TTX). RESULTS: The T-type Ca2+ channel gene alpha-1G was expressed in neonatal heart, the expression level decreased by 80%, in adult sham heart and was reexpressed in MI (158% increases compared to sham; P<0.01). I(Ca-T) was recorded in 11 of 31 MI cells in presence of K+-free, Na+-free external solution and in 9 of 14 cells when I(Na) was suppressed by TTX. I(Ca-T) was not detected in any of 21 sham cells. I(Ca-T) density was 1.1+/-0.4 pA/pF. I(Ca-T) was more sensitive to Ni2+ and less sensitive to nisoldipine. CONCLUSIONS: T-type Ca2+ channel gene and current are reexpressed in rat post-MI remodeled LV myocytes. Its functional significance in the post-MI remodeling process remains to be defined.

Analysis of Variance↗
PubMed2000

Auto-tuning of TITO decoupling controllers from step tests

This paper considers auto-tuning of simple lead-lag decoupler plus decentralized PI/PID controllers for effective control of two-input and two-output (TITO) processes. A new robust identification method from step tests is presented first for SISO processes and then sequentially applied to TITO processes. The resulting 1st-order plus dead-time model is used for decoupler design and the 2nd-order one is used for decentralized PID sequential tuning. The simulation is given for illustration of the proposed tuning.

Journal Article↗
PubMed2000

Structural identification of two metabolites of catechins and their kinetics in human urine and blood after tea ingestion.

Tea is a popular beverage consumed worldwide. The metabolic fate of its major constituents, catechins, however, is not well-known. In this study, two catechin metabolites were detected in the urine and plasma of human volunteers after ingestion of green tea. These metabolites were identified by LC/ESI-MS and NMR as (-)-5-(3',4', 5'-trihydroxyphenyl)-gamma-valerolactone (M4) and (-)-5-(3', 4'-dihydroxyphenyl)-gamma-valerolactone (M6). The renal excretion of M4 and M6 had a 3 h lag time and peaked 7.5-13.5 h after ingestion of a single dose of green tea, while (-)-epigallocatechin (EGC) and (-)-epicatechin peaked at 2 h. M4 and M6 were two major tea metabolites with urinary cumulative excretions as high as 8-25 times the levels of EGC and (-)-epicatechin in some of our subjects, and accounted for 6-39% of the amounts of ingested EGC and (-)-epicatechin. Both the metabolites appeared to be produced by intestinal microorganisms, with EGC and (-)-epicatechin as the precursors of M4 and M6, respectively. Repeated ingestion of green tea produced a slight accumulative effect of the metabolites. They were also detected in the plasma, exhibiting kinetics similar to those of the urinary metabolites, and in the feces. Study on these metabolites may help us further understand the cancer chemopreventive actions and other beneficial effects of tea.

Adult↗