Immediate Release Formulation of Inhaled Beclomethasone Dipropionate-Hydroxypropyl-Beta-Cyclodextrin Composite Particles Produced Using Supercritical Assisted Atomization

In this study, the enhanced solubilization performance of a poorly soluble drug, beclomethasone dipropionate (BDP), was investigated using hydroxypropyl-β-cyclodextrin (HP-β-CD) and ethanol. The enhanced solubility of the drug was determined using the phase solubility method and correlated as a function of both HP-β-CD and ethanol concentrations. The effective progress of drug solubility originated from the formation of cyclodextrin and BDP inclusion complexes and increase in the lipophilicity of the medium, by aqueous ethanol, for hydrophobic BDP. BDP and HP-β-CD composite particles were produced using supercritical assisted atomization (SAA) with carbon dioxide as the spraying medium, 54.2% (w/w) aqueous ethanol as the solvent, and an optimal amount of the dispersion enhancer leucine. The effect of the mass ratio of HP-β-CD to BDP (Z) on the in vitro aerosolization and in vitro dissolution performance of BDP-HP-β-CD composite particles was evaluated. The aerosolization performance showed that the fine particles fraction (FPF) of the composite particles increased with increasing mass ratio. The water-soluble excipient (HP-β-CD) effectively enhance the dissolution rate of BDP from composite particles. This study suggests that BDP-HP-β-CD composite particles produced using SAA can be employed in immediate-release drug formulations for pulmonary delivery.

Accumulation of lipid production in Chlorella minutissima by triacylglycerol biosynthesis-related genes cloned from Saccharomyces cerevisiae and Yarrowia lipolytica

Discovery of an alternative fuel is now an urgent matter because of the impending issue of oil depletion. Lipids synthesized in algal cells called triacylglycerols (TAGs) are thought to be of the most value as a potential biofuel source because they can use transesterification to manufacture biodiesel. Biodiesel is deemed as a good solution to overcoming the problem of oil depletion since it is capable of providing good performance similar to that of petroleum. Expression of several genomic sequences, including glycerol-3-phosphate dehydrogenase, glycerol-3-phosphate acyltransferase, lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, diacylglycerol acyltransferase, and phospholipid:diacylglycerol acyltransferase, can be useful for manipulating metabolic pathways for biofuel production. In this study, we found this approach indeed increased the storage lipid content of C. minutissima UTEX 2219 up to 2-fold over that of wild type. Thus, we conclude this approach can be used with the biodiesel production platform of C. minutissima UTEX 2219 for high lipid production that will, in turn, enhance productivity.

High yield bio-butanol production by solvent-producing bacterial microflora

Highly efficient butanol-producing bacterial microflora were isolated from hydrogen-producing sludge of a sewage treatment plant. Based on denaturing gradient gel electrophoresis (DGGE) analysis and 16s rDNA comparison, four strains from the butanol-producing microflora were identified as Clostridium saccharoperbutylacetonicum, Clostridium butylicum, Clostridium beijernckii, and Clostridium acetobutylicum. The effects of glucose, FeSO(4) · 7H(2)O and yeast extract concentrations on the butanol production by the mixture culture were investigated on batch mode. The medium composition for bio-butanol production was optimized using the Box-Behnken design and response surface methodology (RSM). The maximum butanol production rate (0.25 ± 0.02 g/L-h) and concentration (12.4 g/L) were obtained under the condition of glucose concentration, 60 g/L; FeSO(4) · 7H(2)O, 0.516 g/L; yeast extract concentration, 5.13 g/L. Addition of 6.0 g/L butyric acid significantly increased the butanol titer to 17.51 ± 0.49 g/L. Pressurized fermentation strategy (employed with a 5L fermentor) further enhanced the butanol concentration to 21.35 g/L, along with a maximum butanol rate of 1.25 g/L-h.

Biosilicification of dual-fusion enzyme immobilized on magnetic nanoparticle

Rapid recovery, immobilization, and silica encapsulation of a dual-fusion enzyme was achieved by using iminodiacetic acid (IDA) modified magnetic nanoparticle as a carrier. D-amino acid oxidase (DAAO) of Rhodosporidium toruloides was used as a model enzyme in which a silica-precipitating peptide R5 and a metal ion complexing peptide (His)(6) were fused to its N- and C-terminal, respectively. After charging the magnetic particle with Cu(2+), the dual-fusion DAAO of 0.43 g could be directly recovered from the recombinant E. coli crude extract and immobilized on 1 g of the magnetic particle. Once in contact with hydrolyzed tetramethoxysilane (TMOS), the homogeneously dispersed immobilized dual-fusion DAAO was biosilicificated to form aggregates with size about 50 microm. The silica-encapsulated immobilized DAAO demonstrated a pyruvic acid production rate comparable with that of the naked immobilized DAAO in five repeated batch reactions when D-alanine was used as substrate. Furthermore, 85% of its activity remained after incubation at 60 degrees C for 1 h while the naked immobilized DAAO lost all its activity. This process provides the advantages that recombinant fusion enzyme can be directly recovered from crude extract, silica encapsulation protects the enzyme from leakage and denaturation, and the enzyme activity can be easily retrieved by applying a magnetic field.

Hyaluronic acid production by recombinant Lactococcus lactis

Microbial hyaluronic acid (HA), commonly produced by pathogenic Streptococcus, was made possible to be produced by a generally recognized as safe Lactococcus lactis by coexpressing HA synthase and uridine diphosphate-glucose dehydrogenase (UDP-GlcDH) of Streptococcus equi subsp. zooepidemicus in a nisin-controlled expression (NICE) system. With scarce expressed HA synthase alone, the constructed recombinant L. lactis (LL-NA) strain could produce HA with a concentration about 0.08 g/l in the M17 medium supplemented with 1% (w/v) glucose. In contrast to HA synthase, UDP-GlcDH of Streptococcus could be overexpressed in the NICE system. With coexpression of heterologous UDP-GlcDH with HA synthase, the constructed LL-NAB strain grew slightly slower to a concentration about 10% lower that of the LL-NA strain. However, the HA concentration produced was enhanced about eightfold to 0.65 g/l.

Enhanced hyaluronic acid production in Bacillus subtilis by coexpressing bacterial hemoglobin

Bacillus subtilis strains that can produce hyaluronic acid (HA) were constructed by integrating the HA synthase gene (hasA) and the UDP-glucose dehydrogenase gene of group C Streptococcus (hasB) or of B. subtilis itself (tauD) into the amyE locus of the B. subtilis chromosome. All of the inserted genes were under the control of a strong constitutive vegII promoter of B. subtilis. Although HA production could be achieved by expressing hasA alone, coexpressing hasB or tauD with hasA could enhance HA production at least 2-fold. To replenish the energy consumed for HA biosynthesis, Vitreoscilla hemoglobin (VHb) was coexpressed with the HA-expressing genes. With the expression of VHb, not only the cell concentration was enhanced 25%, but also HA production was further increased by 100%. About 1.8 g/L of HA was obtained by the recombinant strain B. subtilis carrying VHb, hasA, and tauD genes in the expression cassette after 30 h cultivation.

Expressing Vitreoscilla hemoglobin in statically cultured Acetobacter xylinum with reduced O(2) tension maximizes bacterial cellulose pellicle production

Vitreoscilla hemoglobin (VHb) was constitutively expressed in Acetobacter xylinum to enhance bacterial cellulose (BC) production. A pronounced enhancement of BC production in static culture was observed. Reducing O(2) tension in gaseous phase of the culture by tightly sealing the culture tube could also enhance BC production by 70%. O(2) tension in gaseous phase reduced from 21 to 15% in the sealed and static culture of VHb-expressing A. xylinum after 7 days cultivation, while 7.36g/l of BC with yield of 0.44 were obtained. BC pellicle production by VHb-expressing A. xylinum was successfully scaled-up in a sealed 4l disposable zip lock plastic bag with BC yield of 0.38 and concentration of 6.73g/l.

Enhancement of cellulose pellicle production by constitutively expressing vitreoscilla hemoglobin in Acetobacter xylinum

Vitreoscilla hemoglobin (VHb) gene driven by the constitutive bla promoter was expressed in the cellulose-producing Acetobacter xylinum. The expressed VHb was biochemically active and could enhance cell growth in a shaken culture containing cellulase. VHb-expressing A. xylinum (VHb+) exhibited a specific growth rate 50% higher than that of the host strain (VHb-). Probably because of its faster growth rate, the size of tentacled cellulose beads produced by VHb+ was about 20% of that produced by VHb- after 2 days cultivation in a shake-flask. When cultured statically, the amount of cellulose pellicle produced by VHb+ could be 2-fold that produced by VHb-. Cellulose pellicle concentration of 11 g/L was obtained for VHb+, whereas 6 g/L was obtained for VHb- after 6 days of microaerobic incubation.

Expression of Bacterial Hemoglobin in the Yeast, Pichia pastoris, with a Low O2-Induced Promoter

The PsADH2-promoter of Pichia stipitis alcohol dehydrogenase II (ADH II) gene was employed to control the expression of Vitreoscilla hemoglobin (VHb) gene in Pichia pastoris. As in P. stipitis, the promoter was also induced microaerobically in P. pastoris. The expression level of VHb in P. pastoris at low O2 tension (<5% air saturation) was 16 nmol/g dry cell wt, i.e. about 24-fold higher than that at 60% air saturation. The expressed VHb enhanced growth of P. pastoris under microaerobic conditions. The application of O2-regulated promoter in P. pastoris revealed that induction of high-level expression of heterologous protein is feasible without addition of supplementary compounds.

Coexpression of Vitreoscilla hemoglobin reduces the toxic effect of expression of D-amino acid oxidase in E. coli

Expression of the gene (daao) encoding D-amino acid oxidase (DAAO) in Escherichia coli typically results in a marked decrease of cell viability, and it has generally been assumed that the consumption of intracellular D-alanine by DAAO is responsible for this effect. Vitreoscilla hemoglobin (VHb) gene (vgb) was coexpressed with Rhodosporidium toruloides D-amino acid oxidase in E. coli BL21(DE3) and BL21(DE3)pLysS, expression hosts differing in the stringency of suppressing basal transcription. Not only was the toxic effect of DAAO on cell growth relieved but also the pronounced cell lysis of BL21(DE3)pLysS caused by the expression of DAAO was prevented by coexpressing VHb with DAAO. As a result of the higher cell density achieved, DAAO activity about 1.5-fold higher than that of DAAO-expressing control strains could be obtained by DAAO/VHb-coexpressing strains. The relieving effect of VHb on DAAO toxicity resulted from its oxygen-binding ability. The low availability of free intracellular oxygen reduced DAAO activity and consequently its toxicity.

Measles seroepidemiology and decay rate of vaccine-induced measles IgG titers in Taiwan, 1995-1997

Community-based seroepidemiologic studies were conducted to monitor the effectiveness of measles immunization programmes and to estimate the decay rate of vaccine-induced measles IgG titres. Sera collected from a mountain (792 sera), rural (875 sera) and urban (894 sera) populations in 1995-1997 were available. Measles IgG was quantified using a commercial EIA kit. Measles IgG seroprevalence and geometric mean titre (GMT) were calculated by setting the cut-off titre at 50 mIU/ml. The decay rate of measles IgG titres was estimated by assuming that the measles IgG titres, without exposing to wild measles virus, decay exponentially and constantly after 1 year post vaccination. The half-life of measles IgG titres was calculated from the corresponding decay rate. Measles IgG seroprevalences in these three populations have reached >95% in school children (7-18 years old) and >98% in young adults (19-25 years old) but varied from 87 to 96% in pre-school children (4-6 years old). Two-dose vaccinees, comparing with 1-dose vaccinees, had a significantly higher seroprevalence (98 versus 92%, P<0.01) and a slightly longer half-life of measles IgG titres (61 versus 27 months, P=0.08) but the measles IgG GMT in the two groups did not differ significantly (675 versus 618 mIU/ml, P=0.78).

Antibody to the nonstructural protein NS1 of Japanese encephalitis virus: potential application of mAb-based indirect ELISA to differentiate infection from vaccination

An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and differentiate the antibody responses to Japanese encephalitis (JE) virus nonstructural protein NS1 between infected and vaccinated individuals. The results showed that all convalescent sera from JE patients contained NS1-specific IgG antibodies, while 65 and 40% of these sera showed detectable NS1-specific IgM and IgA antibodies, respectively. Specificity analysis showed that NS1-specific IgM and IgA antibodies from JE patients do not cross-react to dengue virus NS1 glycoprotein, while IgG antibodies from 10% of JE patients showed significant cross-reaction to dengue virus NS1 glycoprotein. To differentiate infection from vaccination, the immune sera from 24 children vaccinated with inactivated JE vaccine were analyzed. The data showed that none of these immune sera had detectable NS1-specific IgG antibodies. The results demonstrated the potential application of JE NS1-specific indirect ELISA to differentiate infection from vaccination.

Dengue NS1-specific antibody responses: isotype distribution and serotyping in patients with Dengue fever and Dengue hemorrhagic fever

To understand the antibody responses to dengue (DEN) nonstructural 1 (NS1) glycoprotein and their roles in protective immunity or pathogenesis of dengue fever (DF) and dengue hemorrhagic fever (DHF), we have analyzed the NS1-speccific IgM, IgA and IgG antibodies from patients with DF and DHF. An isotype-specific, indirect enzyme-linked immunosorbent assay (ELISA) was established by coating a NS1-specific monoclonal antibody (MAb), D2/8-1, to capture soluble NS1 antigens secreted in the culture supernatants of Vero cells infected with DEN virus. We observed strong anti-NS1 antibody responses in all of the convalescent sera of patients with DF and DHF. Similar NS1-specific isotypic and serotypic antibody responses were found in the sera from DF and DHF patients. The results showed that all DEN infections induced significant NS1-specific IgG, whereas 75% and 60% of primary DF patients vs. 40% and 90% of secondary DF patients produced IgM and IgA antibodies, respectively. Specificity analysis showed that DEN NS1-specific IgG and IgA antibodies cross-react strongly to Japanese encephalitis (JE) virus NS1 glycoprotein, whereas DEN NS1-specific IgM antibodies do not cross-react to JE virus NS1 glycoprotein at all. The serotype specificity of NS1-specific IgM, IgA and IgG were found to be 80%, 67% and 75% for primary infections, and 50%, 22% and 30% for secondary infections in positive samples of DF patients. Similar pattern was found in DHF patients. The results showed that all of the DF and DHF patients produced significant NS1-specific antibodies. We did not observe direct correlation between the anti-NS1 antibody responses and DHF because sera from patients with DF and DHF showed similar anti-NS1 antibody responses.

Significance of carbohydrate antigen sialyl-Lewis X, sialyl-Lewis A, and possible unknown ligands to adhesion of human urothelial cancer cells to activated endothelium

OBJECTIVE

To assess the contribution of the carbohydrate antigens, sialyl-Lewis X (sLe(x)) and sialyl-Lewis A (sLe(a)), which are known to be ligands for E-selectin, to the adhesion between human urothelial cancer cells and cytokine-activated human endothelial cells.

MATERIALS AND METHODS

We studied the expression of sLe(x) and sLe(a) antigens of three bladder cancer cell lines (JTC 30, JTC 32, and T24) by flow cytometry and the adherence to interleukin 1beta-activated human umbilical vein endothelial cells (HUVEC).

RESULTS

JTC 30 and JTC 32 cells expressed both sLe(x) and sLe(a) antigens, and showed adhesion to activated HUVEC, which was completely abolished by anti-E-selectin antibody. T24 cells expressed neither sLe(x) nor sLe(a) antigen, and did not adhere to activated HUVEC. Each of anti-sLe(a) or anti-sLe(x) antibody partially blocked the attachment of JTC 30 cells to activated HUVEC, and combination of these antibodies almost completely blocked the adhesion. The combination of antibodies did not significantly influence the adhesion of JTC 32 cells.

CONCLUSION

These results indicate that both sLe(a) and sLe(x) carbohydrate antigens are involved in E-selectin-mediated adhesion of some urothelial cancers, and that there might be unknown ligands for E-selectin on urothelial cancer cells.

Differentiation-induced transmigration of HL60 cells across activated HUVEC monolayer involves E-selectin-dependent mechanism

The leukocyte-endothelial adhesive interaction is one of the key mechanisms during inflammation. The human promyelocytic cell line HL60 has been used in a number of studies to characterize leukocyte-endothelial interactions, especially selectin-mediated adhesion. HL60 also has been used in studies to characterize the myeloid cell function during differentiation. In this study, we investigated the adhesive interactions of HL60 to vascular endothelium, either in its undifferentiated state or after dimethylsulfoxide-induced granulocytic differentiation. Granulocytic differentiation of HL60 cells significantly enhanced their transmigration across cytokine-activated (IL-1 beta 10 U/ml, 4 h) HUVEC monolayer. Interestingly, this enhanced transmigration of differentiated HL60 cells was inhibited by pretreatment of the monolayers with anti-E-selectin mAb as well as anti-ICAM-1 mAb or anti-VE-cadherin mAb, suggesting a potential role for E-selectin in transendothelial migration. Further study of this enhanced transmigration mechanism may elucidate the regulation of selectin-mediated leukocyte-endothelial interactions.

The epidemiology of Japanese encephalitis on Taiwan during 1966-1997

Japanese encephalitis (JE) is an endemic disease in Taiwan. A mass vaccination program of children against JE was first implemented in 1968. Along with general improvements in various aspects of living conditions over the years, the program has brought JE well under control. The main characteristics of JE epidemiology in Taiwan in the past 3 decades are as follows. The transmission mode remains unchanged-that is, the amplification stage of the virus in pigs is followed by a human epidemic each year. The frequency of JE incidence has dropped significantly. The incidence rate of confirmed cases was 2.05 per 100,000 in 1967, the highest in record, and merely 0.03 per 100,000 in 1997. Confirmed cases occur sporadically all over the island. The peak of the epidemic season has shifted from August in the 1960s to June since the 1980s. The age distribution of confirmed cases has shifted gradually from mainly children to adults. Vaccine efficacy for those having received more than 2 doses of the vaccine is estimated to be about 85%.

Antibody responses to an immunodominant nonstructural 1 synthetic peptide in patients with dengue fever and dengue hemorrhagic fever

Two flaviviruses, dengue (DEN) virus and Japanese encephalitis (JE) virus, are important because of their global distribution and the frequency of epidemics in tropical and subtropical areas. To study the B-cell epitopes of nonstructural 1 (NS1) glycoprotein and anti-NS1 antibody response in DEN infection, a series of 15-mer synthetic peptides from the predicted B-cell linear epitopes of DEN-2 NS1 protein were prepared. Enzyme-linked immunosorbent assay (ELISA) was performed to analyze antibody responses to these peptides from sera of both DEN and JE patients. One peptide derived from DEN-2 NS1, D2 NS1-P1 (amino acids 1-15), was identified as the immunodominant epitope that reacted with sera from dengue fever (DF) patients but not JE patients. The isotype of D2 NS1-P1-specific antibodies was mainly immunoglobulin M (IgM) in all sera that tested positive. A specificity study demonstrated that sera from all four DEN types reacted with D2 NS1-P1. A dynamics study showed that specific antibodies to this peptide could be detected as early as 2 days after the onset of symptoms. We observed significant anti-D2 NS1-P1 antibody responses in 45% of patients with primary and secondary infections with DF or with dengue hemorrhagic fever. This is the first report demonstrating that significant anti-DEN NS1 antibodies can be induced in the sera of patients with primary DEN infection.

RNA-protein interactions: involvement of NS3, NS5, and 3' noncoding regions of Japanese encephalitis virus genomic RNA

The mechanism of replication of the flavivirus Japanese encephalitis virus (JEV) is not well known. The structures at the 3' end of the viral genome are highly conserved among divergent flaviviruses, suggesting that they may function as cis-acting signals for RNA replication and, as such, might specifically bind to cellular or viral proteins. UV cross-linking experiments were performed to identify the proteins that bind with the JEV plus-strand 3' noncoding region (NCR). Two proteins, p71 and p110, from JEV-infected but not from uninfected cell extracts were shown to bind specifically to the plus-strand 3' NCR. The quantities of these binding proteins increased during the course of JEV infection and correlated with the levels of JEV RNA synthesis in cell extracts. UV cross-linking coupled with Western blot and immunoprecipitation analysis showed that the p110 and p71 proteins were JEV NS5 and NS3, respectively, which are proposed as components of the RNA replicase. The putative stem-loop structure present within the plus-strand 3' NCR was required for the binding of these proteins. Furthermore, both proteins could interact with each other and form a protein-protein complex in vivo. These findings suggest that the 3' NCR of JEV genomic RNA may form a replication complex together with NS3 and NS5; this complex may be involved in JEV minus-strand RNA synthesis.

Silent transmission of the dengue virus in southern Taiwan

Immunoglobulin M (IgM) antibody to dengue virus was examined from a total of 3,099 serum samples collected in southern Taiwan. Of 1,232 sera collected from a junior high school and four elementary schools in Liu-Chiu, 35 were IgM-positive, demonstrating that the dengue virus has been circulating on the island, despite the fact that no epidemic has been reported in the past 10 years. Sixteen of 925 sera collected from three elementary schools in Tung-Kang in 1991 were found to be IgM-positive and two of 192 sera from adults in the local community were positive. The IgM-positive subjects tended to be aggregated around a port. Fishing boats that had stopped in neighboring endemic countries were presumed to have introduced the virus periodically, causing a low level of inapparent infections. In the Kaohsiung area, two of 108 suspected clinical cases and four of 642 community-based sera were IgM-positive. Rapid urbanization has provided appropriate circumstances for vector breeding in this area and the high population density has also increased contact frequency between humans and mosquito vectors. This has, in turn, increased the possibility of silent transmission of the dengue virus via either intermittent reintroduction of the virus or continuation of inapparent infections or both. Establishment of a early warning system using the IgM antibody capture-enzyme-linked immunosorbent assay is suggested for effective monitoring of the disease.

Identification of immunodominant, group-specific and subcomplex-specific, continuous epitopes in the core regions of Japanese encephalitis virus using synthetic peptides

Two flaviviruses, Japanese encephalitis (JE) virus and Dengue (DEN) virus which have high pathogenicity for humans, continue to pose a serious public health problem in tropical and subtropical countries of the world. In order to identify the immunodominant B-cell epitopes for diagnostic application, we have prepared a series of 15-mer synthetic peptides from JE virus core protein based on computer analysis. Four linear, immunodominant epitopes corresponding to amino acids 91-105 (P78), 1-15 (P73), 8-22 (P74), and 34-48 (P75) of JE virus core proteins were identified by employing an enzyme-linked immunosorbent assay (ELISA), using high-titered immune sera from JE-vaccinated children. P78 was found to be the most immunodominant. The sero-specificity of these peptides was tested by binding to seroconverted samples from JE and DEN-1 patients. P78 and P74 belonged to group-specific epitopes which reacted with both JE and DEN-1 patient sera. P73 and P75 belonged to subcomplex-specific epitopes which reacted only with JE but not with DEN-1 patient sera. The study suggests that these peptides corresponding to the immunodominant epitopes of JE virus core protein might have the potential to be used as peptide-based diagnostic reagents for the detection and differentiation of JE and DEN antibody responses.

Clinical efficacy of recombinant human erythropoietin in the treatment of anemia in hemodialysis patients: influence of dosing regimen, iron status, and serum aluminum

To evaluate the clinical efficacy of recombinant human erythropoietin (EPO) and its influencing factors in the treatment of anemia in hemodialysis (HD) patients, 17 chronic stable HD patients (10 males, 7 females; mean age: 46.0 +/- 2.6 years) with severe anemia were enrolled in this study. The study period (ranging from 5 to 11 months) was divided into the initial 12 weeks of correction phase and the subsequent maintenance phase. EPO, 1500 U initially, was administered intravenously twice weekly (BIW group, n = 10) or thrice weekly (TIW group, n = 7) at the end of each HD. Dose was doubled every 4 weeks until up to a maximum dose of 6000 U if increment of hematocrit (Hct) was less than 3%. At the end of correction phase, anemia was markedly improved. Hct and hemoglobin (Hb) increased from 19.3 +/- 0.8 to 28.7 +/- 1.1% and from 6.5 +/- 0.3 to 9.6 +/- 0.4 g/dl, respectively. Fifteen patients (88%) reached to the target Hct of 30% at 13.7 +/- 1.2 weeks. At the end of study, Hct and Hb was maintained at 29.1 +/- 0.7% and 9.6 +/- 0.3 g/dl, respectively. Requirement of EPO dose to reach the target and maintain the stable Hct (greater than or equal to 28%) was 99 +/- 14 and 62 +/- 11 U/kg/week, respectively. Laboratory parameters showed that serum iron, transferrin saturation, sugar and triglyceride decreased significantly and uric acid and aluminum (Al) increased significantly. There was no significant change in predialysis blood pressure, body weight, cardiac ratio, and ECG. Quality of life was markedly improved with the better subjective feelings, physical activity and Karnorfsky index. Common adverse effects included exacerbated hypertension (23%), hyperphosphatemia (18%), hyperkalemia (18%), and flu-like syndrome (12%). All of them could be managed by medical and dialysis treatment. Investigation of influencing factors on response to EPO suggests that 1) TIW group had a better response than BIW group 2) Response was better in patients with more adequate iron status and less severe Al burden. 3) Time to target Hct correlated approximately with basal serum Al levels but did not correlate with basal serum parathyroid hormone levels. In conclusion, low dose of EPO therapy corrects anemia effectively with minimal adverse effects in HD patients. Dosing regimen, iron status, and serum Al will influence the response to EPO.