Spectroscopic study on sorption of hydrogen sulfide by means of red soil

This paper reports the results of the characterization of red soils in relation to the sorption of H2S from coal gas at 500 degrees C by spectroscopic techniques in order to provide more information on red soils' structural change both before and after reaction. In addition, by-products analysis has also been studied using Fourier transform infrared (FTIR) spectroscopy. Before and after the experiments the red soils were characterized with X-ray powder diffraction (XRPD), energy dispersion spectrum (EDS), X-ray photoelectron spectroscopy (XPS) and FTIR spectroscopy. XRPD results indicate that iron oxide species disappear from the original to reacted red soil. EDS analysis shows that a significant amount of sulfur is present in the reacted red soil, which is in agreement with the results of the elemental analysis and the calculated value based on breakthrough curve. XPS regression fitting results further indicate that sulfur retention may be associated with the iron oxides. S 2p XPS fittings point out that the major sulfur species present in the reacted red soil are composed of S(-2), elemental sulfur, polysulfide, sulfite and sulfate. Additionally, the binding energy of iron shifts to a lower position for the reacted red soil, which indicates that iron oxides in the original red soil have been converted into iron sulfide. Appreciable amounts of the by-products CO2, SO2 and COS are detected by on-line FTIR spectroscopy during the initial and later stages of the sorption process. The formation of CO2 is related to the water-shift reaction, and SO2 is probably attributable to the reaction of organic matters and H2S. The concentration of COS is quantified by GC/FPD and found it to be about 350 ppm, which is close to the equilibrium concentration of the reaction of inlet CO and H2S at a temperature of 500 degrees C.

High temperature removal of hydrogen sulfide using an N-150 sorbent

In this study, an N-150 sorbent was used as a high temperature desulfurization sorbent for the removal of hydrogen sulfide from coal gas in a fixed bed reactor. The results indicate that the N-150 sorbent could be used for H(2)S removal in the tested temperature ranges. Regeneration test also reveals that utilization of the N-150 sorbent maintains up to 85% compared to the fresh sorbent. No significant degeneration occurs on the N-150 sorbent. In addition, various concentrations of H(2)S, H(2) and CO were also considered in the performance test of the N-150 sorbent. Except for H(2)S, H(2) and CO act the important roles in the high temperature desulfurization. By increasing the H(2) concentration, the sulfur capacity of the sorbent decreases and an adverse result is observed in the case of increasing CO concentration. This can be explained via water-shift reaction. On the basis of the instrument analysis, X-ray powder diffraction determination and SEM images with EDS spectrum characterization, residual sulfur is found in the regenerated N-150 sorbent and this sulfur species is sulfate which resulted by incomplete regeneration. The sulfate formation and sintering effect are major reasons to cause activity loss in the sulfidation/regeneration cycles.

One year comparison of costs of coronary surgery versus percutaneous coronary intervention in the stent or surgery trial

OBJECTIVES

To compare initial and one year costs of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) in the stent or surgery trial.

DESIGN

Prospective, unblinded, randomised trial.

SETTING

Multicentre study.

PATIENTS

988 patients with multivessel disease.

INTERVENTIONS

CABG and stent assisted PCI.

MAIN OUTCOME MEASURES

Initial hospitalisation and one year follow up costs.

RESULTS

At one year mortality was 2.5% in the PCI arm and 0.8% in the CABG arm (p = 0.05). There was no difference in the composite of death or Q wave myocardial infarction (6.9% for PCI v 8.1% for CABG, p = 0.49). There were more repeat revascularisations with PCI (17.2% v 4.2% for CABG). There was no significant difference in utility between arms at six months or at one year. Quality adjusted life years were similar 0.6938 for PCI v 0.6954 for PCI, Delta = 0.00154, 95% confidence interval (CI) -0.0242 to 0.0273). Initial length of stay was longer with CABG (12.2 v 5.4 days with PCI, p < 0.0001) and initial hospitalisation costs were higher (7321 pounds sterling v 3884 pounds sterling for PCI, Delta = 3437 pounds sterling, 95% CI 3040 pounds sterling to 3848 pounds sterling). At one year the cost difference narrowed but costs remained higher for CABG (8905 pounds sterling v 6296 pounds sterling for PCI, Delta = 2609 pounds sterling, 95% CI 1769 pounds sterling to 3314 pounds sterling).

CONCLUSIONS

Over one year, CABG was more expensive and offered greater survival than PCI but little added benefit in terms of quality adjusted life years. The additional cost of CABG can be justified only if it offers continuing benefit at no further increase in cost relative to PCI over several years.

A feasibility study on the predictive emission monitoring system applied to the Hsinta power plant of Taiwan Power Company

The continuous emission monitoring system (CEMS) can monitor flue gas emissions continuously and instantaneously. However, it has the disadvantages of enormous cost, easily producing errors in sampling periods of bad weather, lagging response in variable ambient environments, and missing data in daily zero and span tests and maintenance. The concept of a predictive emission monitoring system (PEMS) is to use the operating parameters of combustion equipment through thermodynamic or statistical methods to construct a mathematic model that can predict emissions by a computer program. The goal of this study is to set up a PEMS in a gas-fired combined cycle power generation unit at the Hsinta station of Taiwan Power Co. The emissions to be monitored include nitrogen oxides (NOx) and oxygen (O2) in flue gas. The major variables of the predictive model were determined based on the combustion theory. The data of these variables then were analyzed to establish a regression model. From the regression results, the influences of these variables are discussed and the predicted values are compared with the CEMS data for accuracy. In addition, according to the cost information, the capital and operation and maintenance costs for a PEMS can be much lower than those for a CEMS.

Laboratory study of poisoning of a MnO/Fe2O3 catalyst by dimethyl sulfide and dimethyl disulfide

The catalytic incineration of dimethyl sulfide and dimethyl disulfide in a MnO/Fe(2)O(3) fixed bed catalytic reactor was studied. This paper provides information on the affect of the operating parameters that included: inlet temperature, space velocity, VOC concentration and O(2) concentration. The results show that the conversion of VOCs increases as the inlet temperature increases and the space velocity decreases. The higher the concentration of VOCs, the lower their conversions. The O(2) concentration has no affect on the conversion of VOCs. VOCs have poisoning affects on the MnO/Fe(2)O(3) catalyst, especially at lower temperatures.

Distribution and determinants of trihalomethane concentrations in indoor swimming pools

OBJECTIVES

For many decades chlorination has been used as a major disinfectant process for public drinking and swimming pool water in many countries. However, there has been rising concern over the possible link between disinfectant byproducts (DBPs) and adverse reproductive outcomes. The purpose of this study was to estimate the concentrations of trihalomethanes (THMs) in some indoor swimming pools in London and their variation within and between pools and any correlation with other factors.

METHODS

Water samples were collected from eight different indoor swimming pools in London. A total of 44 pool samples were collected and analysed for total organic content (TOC) and THMs. Water and air temperature were measured along with the pH during the collection of pool samples. The level of turbulence and the number of people in the pool at the time were also assessed.

RESULTS

The geometric mean concentration for all swimming pools of TOC was 5.8 mg/l, of total THMs (TTHMs) 132.4 microg/l, and for chloroform 113.3 microg/l. There was a clear positive linear correlation between the number of people in the swimming pool and concentrations of TTHMs and chloroform (r=0.7, p<0.01), and a good correlation between concentrations of TOC and TTHMs (r=0.5, p<0.05) and water temperature and concentrations of TTHMs (r=0.5, p<0.01). There was a larger variation in THMs within pools than between pools.

CONCLUSION

Relatively high concentrations of THMs were found in London's indoor swimming pools. The levels correlated with the number of people in the pool, water temperature, and TOC. The variation in concentrations of THMs was greater within pools than between pools.

[Human factor VIII expression in retrovirus vector-transduced bone marrow stromal cells]

OBJECTIVE

To explore the feasibility of bone marrow stromal cells (BMSCs) used for gene therapy of hemophilia A.

METHODS

Murine and rabbit BMSCs were transduced with a recombinant replication-incompetent retrovirus LNC-FVIII delta B, which encloses a B-domain-deleted (760aa-1,639aa) human factor VIII cDNA. An optimized protocol involving temperature declining (32 degrees C) and centrifugation was used. Antigen and coagulant activity of human FVIII in the cell culture medium were measured by ELISA assay and one-stage method, respectively. Semi-quantitative PCR was performed for the transduction efficiencies. Western blot was used for FVIII protein analysis.

RESULTS

Transduction efficiencies were increased 5- to 8-fold by temperature decline and centrifugation, which resulted in high expression and secretion of FVIII in transduced mouse[(556 +/- 80) ng/10(6) cells/24 hr] and rabbit [480 +/- 56) ng/10(6) cells/24 hr] BMSCs. Coagulant activities of human FVIII secreted from transduced murine and rabbit BMSCs were 2.42 U/10(6) cells/24 hr and 1.8 U/10(6) cells/24 hr, respectively. Western blot analysis demonstrated that the B domain-deleted FVIII cDNA was secreted predominantly as heavy and light chain heterodimers that resemble the native forms in human plasma.

CONCLUSIONS

It was demonstrated that the BMSCs system has potential utility in the gene therapy for hemophilia A.

The kinetics of catalytic incineration of styrene over a MnO/Fe2O3 catalyst

Catalytic incineration is one of the cost-effective technologies to deal with unwanted volatile organic compounds (VOCs). Catalytic incineration of styrene over a MnO/Fe2O3 catalyst was carried out in a bench scale catalytic incinerator. Three kinetic models, the power-rate law, the Mars and van Krevelen model and the Langmuir-Hinshelwood model were used to analyze the results. A differential reactor design was used for best fit of kinetic models in this study. The results show that the Langmuir-Hinshelwood model may be feasible to describe the catalytic incineration of styrene. This suggests that the chemical adsorption of either O2 molecules or O atoms is important in the process of catalytic incineration of styrene.

Simultaneous absorption of SO2 and NO from flue gas with KMnO4/NaOH solutions

The wet scrubbing combined SOx/NOx removal system is an advanced air pollution control device. This study attempts to understand the absorption kinetics in the system. The absorption of diluted SO2 and simultaneous absorption of diluted SO2 and NO, as occurs in flue gases, in a stirred tank reactor with KMnO4/NaOH solutions were carried out at 50 degrees C. The liquid-side and gas-side mass transfer coefficients of the system were determined. The results indicate that the absorption of SO2 is close to completely gas-film controlled where the NaOH concentration is greater than 0.1 M or the KMnO4 concentration is greater than 0.05 M. The increasing gas flow rate has a positive effect on the absorption rate of SO2. The existence of O2 has no significant effect on the absorption rate of SO2. Adding SO2 would decrease the absorption rate of NO; however, the addition of NO has no effect on the absorption rate of SO2.

[Does response of rape to La and critical concentration of La in red earth]

The effects of different concentration of La added in red soil on the growth, yield, content of chlorophyll and peroxidase(POD) activity of rape were studied by pot experiments. The results showed that the growth and yield of rape could be improved by low concentration of La3+, however there was no significant difference between the treatment and the control, and inhibited when the dose were more than 300 mg kg-1 and killed after 600 mg.kg-1 La was added. The decrease of chlorophyll content and chlorophyll a/b was observed when the exogenous concentration of La was more than 15 mg.kg-1. POD activity increased gradually with increasing concentration and prolonging reaction. The feasible application level of La was suggested to be below 15 mg.kg-1.

High level expression of human factor VIII in mammalian cells after retroviral-mediated gene transfer

OBJECTIVE

To develop a retroviral-mediated high efficient expression system of human coagulation factor VIII.

METHODS

The LNC-FVIIIBD retroviral vector was generated by cloning a human B-domain-deleted (760aa-1639aa) Factor VIII (FVIII) cDNA (FVIII cDNA BD) into the retroviral vector pLNCX. Several mammalian cell lines, including NIH3T3, CHO, Cos-7 and human hepatic cell line, L-02, were transduced with viral supernatant from the highest virus-producing PA317 clone. Antigen and coagulant activity of human FVIII in cell culture medium were measured by ELISA and a one-stage method, respectively. RT-PCR was performed for the detection of FVIIIBD mRNA.

RESULTS

Human FVIII was expressed in all four target cells, with the highest FVIII expression observed in NIH3T3. The coagulant activity of secreted FVIII was up to 1.6 U/10(6) cells.24 hrs-1, and the FVIII antigen was 500 ng/10(6) cells.24 hrs-1. FVIII coagulant activity and antigen expressed by transduced CHO cells were 0.12 U/10(6) cells.24 hrs-1 and 62.4 ng/10(6) cells.24 hrs-1, respectively. Human FVIII expression was relatively low in Cos-7 and L-02 cells. RT-PCR results demonstrated transcription of FVIII cDNA BD in the target cells.

CONCLUSIONS

The constructed retroviral vector was able to direct high level expression of human FVIII in various mammalian cell lines. It has potential utility in the future gene therapy for Hemophilia A.

The absorption kinetics of NO in NaClO2/NaOH solutions

A combined wet scrubbing SOx/NOx removal system is an advanced air pollution control process. In this process, the mechanism of NO removal is relatively unknown. Consequently, absorption of NO by alkaline solutions of NaClO2 was studied to clarify the reaction kinetics. The experiments were carried out mainly at temperature 50 degrees C which is the common operating temperature for wet scrubbers. The assumption that the absorption occurred under the fast pseudo-mth reaction regime was verified in the experiments. The absorption rate of NO into NaClO2 solutions was found to be proportional to P(2)NO,0 and [NaClO2]0(2). The addition of NaOH to solutions of NaClO2 decreased the absorption rate of NO. The absorption rate of NO at 25 degrees C is lower than at 50 degrees C. In the study, the absorption rate of NO did not change with changing gas flow rates.

[Analysis of the reason that patients with chronic sinusitis having a negative CT manifestation]

OBJECTIVE

To explore the reason why the CT manifestation of the patients with chronic nasosinusitis is negative.

METHOD

To analyze the clinical and CT manifestation of the patients with chronic sinusitis having a negative CT manifestation.

RESULT

Pathological changes were found in all 8 patients during the course of endoscopic sinus surgery, such as pus storing in the sinus cavity, mucous swelling polypoidly, small polyps formation and so on.

CONCLUSION

The reasons that the patients with chronic sinusitis having a negative CT manifestation are, 1. CT scan can only give a static one-off image, 2. partial volume effect, 3. maybe result from the location of CT scan and the resolving power of tomograph, 4. maybe attribute to the pathological classify of chronic sinusitis.

The kinetics of catalytic incineration of C2H5SH and (CH3)2S2 over a Pt/Al2O3 catalyst

Catalytic incineration is one of the cost-effective technologies to solve the troublesome VOCs. However, some sulfur containing VOCs, such as ethyl mercaptan and dimethyl disulfide, may deactivate the Pt catalyst that is commonly used in the catalytic incineration process. The catalytic incineration of these compounds over a Pt/Al2O3 catalyst was carried out in a bench scale catalytic incinerator. Three kinetic models, such as power-rate law, Mars and Van Krevelen model, and Langmuir-Hinshelwood model were used to analyze the results. A differential reactor design was used for best fit of kinetic models in this study. The results show that the Langmuir-Hinshelwood model is feasible to describe the catalytic incineration of both C2H5SH and (CH3)2S2. This suggests that the chemical adsorption of O2 molecule is important in the process of catalytic incineration of C2H5SH and (CH3)2S2.

The kinetics of catalytic incineration of dimethyl sulfide and dimethyl disulfide over an MnO/Fe2O3 catalyst

The catalytic incineration of dimethyl sulfide and dimethyl disulfide [(CH3)2S and (CH3)2S2] over an MnO/Fe2O3 catalyst was carried out in a bench-scale catalytic incinerator. Three kinetic models (i.e., the power-rate law, the Mars and Van Krevelen model, and the Langmuir-Hinshelwood model) were used to analyze the results. A differential reactor design was used for best fit of kinetic models in this study. The results show that the Langmuir-Hinshelwood model may be feasible to describe the catalytic incineration of (CH3)2S and (CH3)2S2. This suggests that the chemical adsorption of O2 molecules is important in this incineration.

The catalytic incineration of (CH3)2S and its mixture with CH(3)SH over a Pt/Al(2)O(3) catalyst

Catalytic incineration is one of the cost-effective technologies to solve the troublesome volatile organic compounds (VOCs). However, some sulfur containing VOCs, such as dimethyl sulfide, may deactivate the Pt catalyst that is commonly used in the catalytic incineration process. This paper provides information on the poisoning effect of (CH3)2S. The catalytic incineration of (CH3)2S, typically emitted from the petrochemical industry, over a Pt/Al(2)O(3) fixed bed catalytic reactor was studied. The effects of operating parameters including inlet temperature, space velocity, (CH3)2S concentration, O2 concentration and catalyst size were characterized. Catalytic incineration on a mixture of (CH3)2S with CH(3)SH was also tested. The results show that the conversions of (CH3)2S increase as the inlet temperature increases and the space velocity decreases. The higher the (CH3)2S concentration is, the lower its conversion is. The O2 concentration has a positive effect on the conversion of (CH3)2S. (CH3)2S has a poisoning effect on the Pt/Al(2)O(3) catalyst, especially at lower temperatures. The conversion of (CH3)2S is significantly suppressed by the existence of CH(3)SH.

[Carrier detection and prenatal diagnosis for hemophilia A]

OBJECTIVE

To establish a simple, rapid carrier detection and prenatal diagnosis system for hemophilia A.

METHODS

Intron 22 inversion in FVIII gene was directly examined by long distance polymerase chain reaction. Polymorphism of factor VIII intragenic RFLP of Bcl I, STR within intron 13 and 22, and extragenic DXS 52 (St 14) VNTR loci by hereditary linkage analysis were assayed.

RESULTS

The diagnostic rates of these loci were 47.6% (intron 22 inversion), 27.8% (Bcl I), 28.6% and 29.4% (STR within intron 13 and 22), and 81.3% (DXS52), respectively. The overall diagnostic rate in 21 families was 94.7%.

CONCLUSIONS

The diagnosis in hemophilia A patients or carriers can be made if intron 22 inversion is present. The intragenic and extragenic loci hereditary linkage analysis could be used to establish the diagnosis in intron 22 inversion negative patients.

Detection and analysis of depolarization artifacts in rotating-compensator polarimeters

Absolute constraints, namely, the Schwarz inequality and a complementary expression derived by us, are used to obtain corresponding absolute constraints on the Fourier coefficients of the intensity transmitted through rotating-compensator polarimeters and ellipsometers. These expressions allow the investigation of artifacts that result in mixed or apparently mixed polarization states over the cross section of the beam, the averaging time of the detector, or the frequency passband of the dispersing element. Examples include multiple internal reflections or inhomogeneous strain within an element, scattered light, and other types of system and component defects that cannot be accessed by means of polarization-state data alone. We apply these results to our polarizer-sample-compensator-analyzer (PSCA) ellipsometer to illustrate capabilities. A simple analytic model is shown to give a quantitative description of depolarization in systems for which the resolution is finite and the retardation varies with wavelength.

Spray scrubbing of the nitrogen oxides into NaClO2 solution under acidic conditions

The operating conditions of this study were closed to the typical operating conditions of flue gas desulfurization system in the coal-fired power plant. The objective of this study was to investigate the absorption performance of lean NO in an aqueous solution of acidic sodium chlorite using a bench-scale spraying column. The NO conversion and NOx removal efficiency were increasing with the increasing NO concentration, retention time, sodium chlorite concentration, operating temperature, and decreasing initial pH of solution. As the sodium chlorite concentration were higher than 0.4 M, the NO conversion and NOx removal efficiency were 100% and 80%, respectively. The NO conversion and NOx removal efficiency under initial pH 4-7 were higher than that of initial pH > 7. It meant that this process might be suitable to combining with traditional wet flue gas desulfurization system. As the NO2/NOx ratio in the effluent gas was closed to 0.5, it might be suitable to be absorbed in the second scrubbing column operated under alkaline condition.

Removal of SO2 and NO from flue gas by wet scrubbing using an aqueous NaClO2 solution

This study used a NaClO2/NaOH solution as the additive/absorbent to determine the extent of NOx removal in a wet scrubbing system. A combined SOx/NOx removal system was also tested. The experiments were performed in a bench-scale spraying sieve tray wet scrubber in a continuous mode. The operating variables included NO and SO2 concentrations, L/G ratio, molar ratio, and initial pH. The results of the individual DeNOx experiments show that the maximum DeNOx efficiencies ranged from 3.1 to 12.6%. The results of the combined DeSOx/DeNOx experiments show that the maximum DeNOx and DeSOx efficiencies ranged from 36.6 to 71.9% and from 89.4 to 100.0%, respectively. The major parameters affecting NOx removal efficiencies are the L/G ratio and the dosage of additive. The major parameter influencing DeSOx efficiencies is the L/G ratio.

[Retroviral-mediated high efficient in vitro expression of human coagulation factor VIII]

OBJECTIVE

To develop a retroviral-mediated high efficient expression system of human coagulation factor VIII.

METHODS

The retroviral vector LNC-VIIIBD was generated by cloning a B-domain-deleted FVIII cDNA (760aa - 1639aa) into retroviral vector pLNCX. Several cell lines including NIH3T3, CHO, COS-7 and human hepatic cell line L-02 were infected with viral supernatant from the highest productive PA317 clones. The antigen and procoagulant activity of human FVIII in the cell culture medium were measured by ELISA assay and one-stage method, respectively. RT-PCR was performed for the detection of F VIII BD mRNA.

RESULTS

Human FVIII was expressed in all four target cells. The highest expression was observed in NIH3T3, the procoagulant activity of secreted FVIII was up to 1.6 U, and the FVIII antigen was 500 ng by 10(6) cells/ml in 24 hours, respectively.

CONCLUSION

The constructed retroviral vector was able to generate high level expression of human FVIII in some cell lines, and it might have potential utility in the gene therapy for Hemophilia A.

Antibody binding regions on human nerve growth factor identified by homolog- and alanine-scanning mutagenesis

The binding specificities of a panel of mouse monoclonal antibodies (MAbs) to human nerve growth factor (hNGF) were determined by epitope mapping using chimeric and point mutants of NGF. Subsequently, the MAbs were used to probe NGF structure-function relationships. Six MAbs, which recognize distinct or partially overlapping regions of hNGF, were evaluated for their ability to block the binding of hNGF to the TrkA and p75 NGF receptors in various in vitro assays, which included blocking of TrkA autophosphorylation and blocking of NGF-dependent survival of dorsal root ganglion sensory neurons. Three MAbs (911,912,938) were potent blockers of all activities. Potent blocking of p75 binding occurs only with MAb 909, which recognizes an NGF region identified by mutagenesis as important for NGF-p75 binding. These results are consistent with recently proposed models of binding regions involved in NGF-TrkA and NGF-p75 interactions generated through mutagenic analysis and structure determination of the NGF-TrkA complex. These studies provide insight to the epitope specificities and potency of MAbs that would be useful for physiological NGF blocking studies.

[Mechanism of tissue factor expression on NB4 cells down-regulated by all-trans retinoic acid and arsenic trioxide]

OBJECTIVE

To investigate molecular mechanism of tissue factor (TF) expression on acute promyelocytic leukemia cell line NB4 cells down-regulated by all-trans retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)).

METHODS

Cyclohexamide (CHX) inhibition test for de novo protein synthesis and actinomycin D (Act D) inhibition test for RNA synthesis were used to check the effect of ATRA on the TF expression. TF antigen of U937 cells transfected with pMSCV-PML-RARalpha treated with or without ATRA and As(2)O(3) was detected.

RESULTS

CHX treatment completely suppressed the down-regulation effect of ATRA on the TF mRNA expression, Act D inhibition test showed that half-life of TF mRNA in treated NB4 cells was shortened to about 30 min from that of around 60 min in untreated NB4 cells. The TF antigen contents in U937 cells transfected with pMSCV-PML-RARalpha were significantly higher than that in transfected U937 cells with retrovirus vector. Both ATRA and As(2)O(3) could down-regulate the TF antigen level in U937 cells transfected with or without PML-RARalpha.

CONCLUSION

The modulation of the TF mRNA expression in NB4 cells by ATRA might be indirect. TF mRNA destabilization was involved in the TF regulation process mediated by ATRA. Elevated TF antigen level in U937 cells transfected with pMSCV-PML-RARalpha may be related to the fusion protein PML-RARalpha. The down-regulation effect of ATRA and As(2)O(3) on the TF expression of U937 cells might not involve the fusion protein.

[Effects of holothuria glycosaminoglycan on the expression of tissue factor and thrombomodulin in stimulated endothelial cells]

OBJECTIVE

To study the mechanism of antithrombotic effects of holothuria glycosaminoglycan (GAG).

METHODS

Endothelial cells from human umbilical vein which were pre-induced with 1 mg/L lipopolysaccharide, were treated by GAG (1 mg/L, 5 mg/L, and 10 mg/L, respectively) and 5 mg/L heparin as a control for 6 hours. Procoagulant activity (PCA), the expressions of tissue factor (TF) antigen and thrombomodulin (TM) antigen and their mRNA transcriptions were investigated.

RESULTS

GAG could down-regulate the expression of TF antigen and mRNA, up-regulate the expression of TM antigen and mRNA, down-regulate the PCA of stimulated endothelial cells.

CONCLUSION

Down-regulating TF expression and up-regulating TM expression of stimulated endothelial cells may be one of the mechanisms of GAG antithrombosis.

[A study on the relationship between serum free alpha-subunit of human chorionic gonadotropin and pregnancy induced hypertension]

OBJECTIVE

To determine the correlation of free alpha subunit of human chorionic gonadotropin (F alpha-hCG) with pregnancy induced hypertension(PIH), and to observe the immunohistochemical expression of alpha-hCG in placentae from PIH.

METHODS

Serum was obtained from 66 successive pregnant women diagnosed with PIH (5 mild, 8 middle and 53 severe) at 21-43 weeks' gestation. A group of 30 non PIH gravid women were used as controls. The serum was assayed for F alpha-hCG by monoclonal technology and human prolactin was assayed for correcting the blood contraction. Immunolocalization and the intensity of the immunohistochemical stained in the placentae from 13 PIH and 13 normal pregnancies.

RESULTS

Significant difference was noted between the two groups mean of F alpha-hCG (the control group VS PIH group was 528 +/- 421 IU/L VS 222 +/- 129 IU/L, P < 0.001); no significant between two groups of hPL. The mean value of F alpha-hCG of severe PIH revealed significantly higher than the mild and moderate (569 +/- 455 IU/L VS 363 +/- 159 IU/L, P < 0.01); The leve of F alpha-hCG in group of proteinuria > or = +++ was higher than that of proteinuria < +++ (598 +/- 474 IU/L VS 425 +/- 291 IU/L, P > 0.05). The intensity of alpha-hCG immunostaining in syncytiotrophoblast was significantly increased in 13 PIH compared with the control group (the strong positive rate 10/13 VS 3/13 P < 0.025).

CONCLUSIONS

The level of F alpha-hCG are significantly higher in PIH compared with controls. The more severe the higher level of F alpha-hCG is in PIH. The higher level of alpha-hCG has the basement of placentae pathology.

The lipid treatment assessment project (L-TAP): a multicenter survey to evaluate the percentages of dyslipidemic patients receiving lipid-lowering therapy and achieving low-density lipoprotein cholesterol goals

OBJECTIVE

To determine the percentage of patients in the multicenter Lipid Treatment Assessment Project receiving lipid-lowering therapy who are achieving low-density lipoprotein cholesterol (LDL-C) goals as defined by National Cholesterol Education Program (NCEP) guidelines.

METHODS

Adult patients with dyslipidemia, who had been receiving the same lipid-lowering therapy for at least 3 months, were assessed at investigation sites. Lipid levels were determined once in each patient at the time of enrollment. The primary end point was the success rate, defined as the proportion of patients who achieved their LDL-C target level as specified by NCEP guidelines.

RESULTS

A total of 4888 patients from 5 regions of the United States were studied. Of these, 23% had fewer than 2 risk factors for coronary heart disease (CHD) and no evidence of CHD (low-risk group), 47% had 2 or more risk factors and no evidence of CHD (high-risk group), and 30% had established CHD. Overall, only 38% of patients achieved NCEP-specified LDL-C target levels; success rates were 68% among low-risk patients, 37% among high-risk patents, and 18% among patients with CHD. Drug therapy was significantly (P< or =.001) more effective than nondrug therapy in all patient risk groups. However, many patients treated with lipid-lowering drugs did not achieve LDL-C target levels.

CONCLUSIONS

Large proportions of dyslipidemic patients receiving lipid-lowering therapy are not achieving NCEP LDL-C target levels. These findings indicate that more aggressive treatment of dyslipidemia is needed to attain goals established by NCEP guidelines.

Validation of a rat pheochromocytoma (PC12)-based cell survival assay for determining biological potency of recombinant human nerve growth factor

A method has been validated, according to the Guidelines of the International Conference on Harmonization (ICH), for precise quantitation of the biological activity of recombinant human nerve growth factor (rhNGF) for lot release testing. The assay is based on the survival of a subclone of rat pheochromocytoma PC12 cells (PC12-CF) in response to rhNGF. Cell survival is measured by monitoring the reduction, by living cells, of the alamarBlue dye into a red form which is highly fluorescent. The assay is simple, has high throughput (performed in 96-well microtiter plates) and shows reproducible dose-response curves in the concentration range of 0.2-50 ng/ml. The method was validated for its linearity, accuracy, precision, robustness, and to meet current regulatory requirements. The assay demonstrated good linearity, yielding a coefficient of determination of 0.9902. Sample recovery studies demonstrated an accuracy ranging from 96 to 98%. The repeatability of the assay and intermediate precision had coefficients of variation (CV) of <9%. The assay was stability-indicating since it was able to detect changes in rhNGF samples degraded by protease treatment and in a number of isolated rhNGF variants. Robustness was demonstrated by the relative insensitivity of the assay to small deliberate changes in key method parameters. The validation data, provided in this manuscript, indicate that the newly described bioassay for rhNGF is robust, accurate, precise, and suitable for lot release potency testing of rhNGF.

Agonist-directed signaling of serotonin 5-HT2C receptors: differences between serotonin and lysergic acid diethylamide (LSD)

For more than 40 years the hallucinogen lysergic acid diethylamide (LSD) has been known to modify serotonin neurotransmission. With the advent of molecular and cellular techniques, we are beginning to understand the complexity of LSD's actions at the serotonin 5-HT2 family of receptors. Here, we discuss evidence that signaling of LSD at 5-HT2C receptors differs from the endogenous agonist serotonin. In addition, RNA editing of the 5-HT2C receptor dramatically alters the ability of LSD to stimulate phosphatidylinositol signaling. These findings provide a unique opportunity to understand the mechanism(s) of partial agonism.

Leginon: a system for fully automated acquisition of 1000 electron micrographs a day

We have developed a system to automatically acquire large numbers of acceptable quality images from specimens of negatively stained catalase, a biological protein which forms crystals. In this paper we will describe the details of the system architecture and analyze the performance of the system as compared to a human operator. The ultimate goal of the system if to automate the process of acquiring cryo-electron micrographs.

Neuronal overexpression of APPL, the Drosophila homologue of the amyloid precursor protein (APP), disrupts axonal transport

The two pathological hallmarks of Alzheimer's disease, amyloid plaques and neurofibrillary tangles, involve two apparently unrelated proteins, the amyloid precursor protein (APP) and Tau. Although it is known that aberrant processing of APP is associated with Alzheimer's disease, the definitive role of APP in neurons is not yet clear. Tau regulates microtubule stabilization and assembly in axons and is, thus, an essential component of the microtubule-associated organelle transport machinery. Although several groups have reported physical interaction between APP and Tau, and induction of Tau phosphorylation by APP and beta-amyloid peptide, the functional connection between APP and Tau is unclear. To explore the possibility that the functions of these two proteins may somehow converge on the same cellular process, we overexpressed APPL, the Drosophila homologue of APP, along with Tau in Drosophila neurons. Panneural coexpression of APPL and Tau resulted in adults that, upon eclosion, failed to expand wings and harden the cuticle, which is suggestive of neuroendocrine dysfunction. We analyzed axonal transport when Tau and APPL were coexpressed and found that transport of axonal cargo was disrupted, as evidenced by increased retention of synaptic proteins in axons and scarcity of neuropeptide-containing vesicles in the distal processes of peptidergic neurons. In an independent approach, we demonstrated genetic interaction and phenotypic similarity between APPL overexpression and mutations in the Kinesin heavy chain (Khc) gene, the product of which is a motor for anterograde vesicle trafficking.

Association between HPV 16/18 infection and expression of P53 protein in laryngeal papillomas

To understand the relationship between expression of P53 protein and HPV16/18 infection in laryngeal papillomas, PCR and immunohistochemical techniques were used to examine the paraffin-embedded tissue samples of laryngeal papillomas from 35 subjects. HPV 16/18-DNA was found in 24 cases of laryngeal papillomas (68.8%). Overexpression of P53 protein was detected in 19 cases (54.3%). Both HPV16/18-DNA and overexpression of P53 protein were demonstrated in 12 cases of laryngeal papillomas (34.3%). Our results suggest that HPV16/18 infection and P53 gene mutation are associated with pathogenesis of laryngeal papillomas. The relation between HPV infection and P53 mutation in tissues of laryngeal papillomas remains to be clarified.

Formation and specification of ventral neuroblasts is controlled by vnd in Drosophila neurogenesis

During Drosophila neural development, neuroblasts delaminate from the neuroectoderm of each hemisegment in a stereotypic orthogonal array of five rows and three columns (ventral, intermediate, and dorsal). Prevailing evidence indicates that the individual neuroblast fate is determined by the domain-specific expression of genes along the dorsoventral and anteroposterior axis. Here, we analyze the role of Vnd, a NK-2 homeodomain protein, expressed initially in the ventral neuroectoderm adjacent to the ventral midline, in the dorsoventral patterning of the neuroectoderm and the neuroblasts. We show that in vnd null mutants most ventral neuroblasts do not form and the few that form do not develop ventral fates, but instead develop intermediate-like fates. Furthermore, we demonstrate that Vnd influences the gene expression patterns in the ventral proneural clusters and neuroectoderm, and that its action in neuroblast formation includes, but is not exclusive to the activation of proneural AS-C genes. Through the use of GAL4/UAS gene-expression system we show that ectopic Vnd expression can promote ventral-like fates in intermediate and dorsal neuroblasts and can suppress certain normal characteristics of the intermediate and dorsal neuroectoderm. Our results are discussed in the context of the current evidence in dorsoventral patterning in the Drosophila neuroectoderm.

[Using superselective digital subtraction angiographic localization and embolization to control vascular pulsative tinnitus]

Treating two cases of vascular palsative tinnitus with digital subtraction angiographic and superselective embolization was reported in this paper. The etiology pathogenesis, clinical sign and its treatment were also discussed.

Expression and characterization of recombinant murine lactoferrin

Lactoferrin (Mw=78 kDa) is a member of the transferrin family of iron-binding glycoproteins. Previous studies carried out primarily in vitro indicate that the protein has multifunctional properties and may be involved in regulation of iron homeostasis, inhibition of bacterial growth and regulation of immune responses. However, the significance and species specificity of these proposed functions in vivo have not been adequately addressed due to lack of sufficient purified homospecies lactoferrin for analysis in small animal models. We previously reported the successful production of biologically active recombinant human lactoferrin using an Aspergillus expression system. In the present study, we report the production of recombinant murine lactoferrin using a similar expression strategy. Recombinant murine lactoferrin was purified to homogeneity and was similar in size and immunoreactivity to native murine milk lactoferrin. The recombinant protein was correctly processed at its N-terminus and was glycosylated. Interestingly, while both human and murine lactoferrin bind iron in a 2:1 molar ratio, iron bound to recombinant murine lactoferrin was more acid labile than human lactoferrin, demonstrating species-specific variation in the stability of iron-binding to this protein. Finally, the availability of recombinant murine lactoferrin will now facilitate the study of the species specificity of lactoferrin action in a mouse model system.

Regulation of serotonin-2C receptor G-protein coupling by RNA editing

The neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) elicits a wide array of physiological effects by binding to several receptor subtypes. The 5-HT2 family of receptors belongs to a large group of seven-transmembrane-spanning G-protein-coupled receptors and includes three receptor subtypes (5-HT2A, 5-HT(2B) and 5-HT(2C)) which are linked to phospholipase C, promoting the hydrolysis of membrane phospholipids and a subsequent increase in the intracellular levels of inositol phosphates and diacylglycerol. Here we show that transcripts encoding the 2C subtype of serotonin receptor (5-HT(2C)R) undergo RNA editing events in which genomically encoded adenosine residues are converted to inosines by the action of double-stranded RNA adenosine deaminase(s). Sequence analysis of complementary DNA isolates from dissected brain regions have indicated the tissue-specific expression of seven major 5-HT(2C) receptor isoforms encoded by eleven distinct RNA species. Editing of 5-HT(2C)R messenger RNAs alters the amino-acid coding potential of the predicted second intracellular loop of the receptor and can lead to a 10-15-fold reduction in the efficacy of the interaction between receptors and their G proteins. These observations indicate that RNA editing is a new mechanism for regulating serotonergic signal transduction and suggest that this post-transcriptional modification may be critical for modulating the different cellular functions that are mediated by other members of the G-protein-coupled receptor superfamily.

The stability of recombinant human growth hormone in poly(lactic-co-glycolic acid) (PLGA) microspheres

PURPOSE

The development of a sustained release formulation for recombinant human growth hormone (rhGH) as well as other proteins requires that the protein be stable at physiological conditions during its in vivo lifetime. Poly(lactic-co-glycolic acid) (PLGA) microspheres may provide an excellent sustained release formulation for proteins, if protein stability can be maintained.

METHODS

rhGH was encapsulated in PLGA microspheres using a double emulsion process. Protein released from the microspheres was assessed by several chromatrographic assays, circular dichroism, and a cell-based bioassay. The rates of aggregation, oxidation, diketopiperazine formation, and deamidation were then determined for rhGH released from PLGA microspheres and rhGH in solution (control) during incubation in isotonic buffer, pH 7.4 and 37 degrees C.

RESULTS

rhGH PLGA formulations were produced with a low initial burst (< 20%) and a continuous release of rhGH for 30 days. rhGH was released initially from PLGA microspheres in its native form as measured by several assays. In isotonic buffer, pH 7.4 and 37 degrees C, the rates of rhGH oxidation, diketopiperazine formation, and deamidation in the PLGA microspheres were equivalent to the rhGH in solution, but aggregation (dimer formation) occurred at a slightly faster rate for protein released from the PLGA microspheres. This difference in aggregation rate was likely due to the high protein concentration used in the encapsulation process. The rhGH released was biologically active throughout the incubation at these conditions which are equivalent to physiological ionic strength and pH.

CONCLUSIONS

rhGH was successfully encapsulated and released in its fully bioactive form from PLGA microspheres over 30 days. The chemical degradation rates of rhGH were not affected by the PLGA microspheres, indicating that the internal environment of the microspheres was similar to the bulk solution. After administration, the microspheres should become fully hydrated in the subcutaneous space and should experience similar isotonic conditions and pH. Therefore, if a protein formulation provides stability in isotonic buffer, pH 7.4 and 37 degrees C, it should allow for a safe and efficacious sustained release dosage form in PLGA microspheres.

Long-acting growth hormones produced by conjugation with polyethylene glycol

Derivatives of human growth hormone (hGH) of increasing size were produced by reaction with the N-hydroxysuccinimide ester of polyethylene glycol-5000 (PEG5000), a 5-kDa reagent that selectively conjugates to primary amines. By adjusting the reaction conditions and purification procedure, it was possible to isolate hGH derivatives containing up to seven PEG moieties that altered the Stokes radius and thereby the effective molecular masses of the unmodified hormone from 22 to 300 kDa. Fortunately, the most reactive amines were ones that did not lie in either of the two sites important for receptor binding. Nonetheless, increasing the level of PEG modification linearly reduced the affinity of hGH for its receptor and increased the EC50 in a cell-based assay up to 1500-fold. Most of the reduction in affinity was the result of slowing the association rate for the receptor. The clearance rate of hGH in rats was inversely proportional to effective molecular weight and closely fit a filtration model. We have tested the potency of these analogs by injecting them daily or every 6 days into hypophysectomized rats and determining the effects on body and organ growth. The efficacy of these analogs was optimal for hGH conjugated with 5 eq of PEG5000, and the potency was increased by about 10-fold compared with unmodified hGH. Such PEG-hGH derivatives show promise as long-acting alternatives to daily injections of hGH. More generally these studies show that improving hormone clearance properties, even at the expense of reducing receptor binding affinity, can lead to dramatic increases in hormone efficacy.

Novel assays based on human growth hormone receptor as alternatives to the rat weight gain bioassay for recombinant human growth hormone

Two methods, High-Performance Receptor Binding Chromatography (HPRBC) and Cell Proliferation (CP), have been developed as alternatives to the classical hypophysectomized rat weight gain bioassay for the determination of potency for recombinant human growth hormone (rhGH). In the HPRBC assay, rhGH is combined with an excess of the soluble extracellular domain of the recombinant human growth hormone receptor (referred to as 'receptor' in the discussion of the HPRBC assay). Nondenaturing size-exclusion chromatography is used to analyzed the resulting complex, which forms in a 2:1 receptor to rhGH ratio. The 2:1 complex is assayed at a concentration near the Kd (approximately 0.4 nM), providing high specificity for rhGH and detection of rhGH variants with reduced activity. In the CP assay, a mouse myeloid leukaemia cell line (FDC-P1) transfected with the full-length receptor is exposed to varying levels of rhGH for 16-20 h. The incorporation of 3H-thymidine into DNA is used as an index of cell proliferation. The results show that the HPRBC assay provides significantly improved precision with a relative standard deviation (RSD) of < or = 5% vs. an RSD of 23% for the rat bioassay. The CP assay has RSDs of 4-16%. Analysis of rhGH variants and mutants shows that the potencies measured by both the HPRBC and CP assays are in general agreement with the rat weight gain bioassay. Both of the HPRBC and CP assays are sufficiently rugged for operating in a Good Manufacturing Practices (GMP) routine batch release testing environment. In vitro alternatives such as the HPRBC and CP assays build a foundation for replacing the hypophysectomized rat weight gain bioassay by correlating receptor dimerization, binding specificity and signal transduction with the biological activity of rhGH.

vnd, a gene required for early neurogenesis of Drosophila, encodes a homeodomain protein

The development of the central nervous system in Drosophila is initiated by the segregation of neuroblasts, the neural progenitors, from the embryonic neuroectoderm. This process is guided by at least two classes of genes: the achaete-scute complex (AS-C) proneural genes and the neurogenic genes. It has been known for some time that loss-of-function mutations in the AS-C result in neural hypoplasia and the first observed defect is failure of segregation of a fraction of neuroblasts. Loss-of-function mutations at the ventral nervous system defective (vnd) locus are known to lead to similar phenotypic defects in early neurogenesis. More recently, the vnd locus has been implicated in the regulation of the proneural AS-C genes and the neurogenic genes of the Enhancer of split complex. In this paper we report the identification of a transcript associated with the vnd locus, the transcript distribution in embryogenesis, which is compatible with the nervous system mutant phenotypes described for this gene, and that the protein product is a member of the NK-2 homeodomain family. We discuss these findings within the framework of early Drosophila neurogenesis and the known phenotypes associated with the vnd locus.

[Analysis of short tandem repeats polymorphism in the phenylalanine hydroxylase gene and its application to prenatal gene diagnosis of phenylketonuria]

There is a polymorphic tetranucleotide short tandem repeats (STR) sequence in the intron 3 of the phenylalanine hydroxylase (PAH) gene. The polymorphism of this STR sequence in Chinese was analysed on 36 normal individuals and 16 PKU families. After PCR amplification, the DNA fragments were separated on polyacrylamide sequencing gel and visualized by silver-staining. Seven alleles were identified with frequencies of 0.028, 0.042, 0.014, 0.138, 0.542, 0.208 and 0.028 in normal populations, and 0.016, 0.078, 0.047, 0.312, 0.375, 0.156 and 0.016 in PKU families, and PICs of 0.585 and 0.693, respectively. This polymorphic marker is very useful in quick prenatal gene diagnosis in PKU families, and prenatal gene diagnosis was performed by linkage analysis in two pregnancies at risk.

m-chlorophenylpiperazine and m-trifluoromethylphenylpiperazine are partial agonists at cloned 5-HT2A receptors expressed in fibroblasts

Serotonin2A (5-HT2A) and 5-HT2C receptors share numerous pharmacological properties. Two compounds thought to discriminate between these two receptor subtypes are m-chlorophenypiperazine (mCPP) and m-trifluoromethylphenylpiperazine (TFMPP). These two drugs have been classified as antagonists at 5-HT2A receptors but as agonists at 5-HT2C receptors on the basis of phosphoinositide hydrolysis studies in cerebral cortex and choroid plexus, respectively. To determine more fully the properties of mCPP and TFMPP at 5-HT2A receptors, NIH 3T3 fibroblasts transfected with the 5-HT2A receptor complementary DNA (GF6 cells) were used as a model system of receptor function. These cells express approximately 15-fold higher 5-HT2A receptor density than is found in cerebral cortex. In GF6 cells, mCPP and TFMPP dose-dependently stimulated phosphoinositide hydrolysis with maximal effects less than that of 5-HT. This agonist activity was blocked by 5-HT2A receptor antagonists but not by prior treatment with pertussis toxin. Partial inactivation of 5-HT2A receptors with phenoxybenzamine decreased the maximal effects of mCPP and TFMPP but did not eliminate agonist activity. Thus mCPP and TFMPP are partial agonists at 5-HT2A receptors in GF6 cells, and these agonist properties are retained even under conditions where receptor density is comparable to that of cerebral cortex. Although it has not yet been demonstrated that mCPP and TFMPP are agonists at central 5-HT2A receptors, this possibility should be considered when evaluating in vivo effects of these drugs.

Effect of caffeine treatment on plasma renin activity and angiotensin I concentrations in rats on a low sodium diet

Animals treated acutely with an adenosine receptor antagonist have elevated plasma renin activity. This observation suggests that endogenous adenosine plays a physiologically significant role in restraining renin release. However, it is unclear whether chronic blockade of adenosine receptors would cause a rise of renin activity since tolerance to adenosine blockade is known to develop quickly. An earlier study partially addressed this question by showing that chronic blockade of adenosine receptors with caffeine exacerbated both the rise of plasma renin activity and the decline of renal function in 2-kidney-1-clip (2K1C) renovascular hypertensive rats. However, that study did not determine whether the difference in renin activity occurred solely as a secondary result of the difference in renal function. The purpose of this study was to reexamine the effect of chronic caffeine consumption on plasma renin activity and angiotensin I levels in animals in another high-renin model, i.e., the low sodium diet. The low sodium diet is devoid of the potential confounding effect of deteriorating renal function associated with the 2K1C renovascular hypertension model. In this study, animals received normal rat chow and drank either 0.1% caffeine water or vehicle for ten days. After ten days, all rats were switched to a low sodium diet for three weeks. Plasma renin activity and plasma angiotensin I levels were measured before, and at 1 and 3 weeks after initiating the low sodium diet. The results of this study show that chronic blockade of adenosine receptors with 0.1% caffeine water increases plasma renin activity and angiotensin I concentration before and throughout the three weeks when animals were on the low sodium diet. The results of this study suggest that the inhibitory role of adenosine on renin release is a general physiological process, rather than a special situation applicable only to the 2K1C model.