Enhancement of CO2 adsorption on oxygen-functionalized epitaxial graphene surface under near-ambient conditions.

The functionalization of graphene is important in practical applications of graphene, such as in catalysts. However, the experimental study of the interactions of adsorbed molecules with functionalized graphene is difficult under ambient conditions at which catalysts are operated. Here, the adsorption of CO2 on an oxygen-functionalized epitaxial graphene surface was studied under near-ambient conditions using ambient-pressure X-ray photoelectron spectroscopy (AP-XPS). The oxygen-functionalization of graphene is achieved in situ by the photo-induced dissociation of CO2 with X-rays on graphene in a CO2 gas atmosphere. The oxygen species on the graphene surface is identified as the epoxy group by XPS binding energies and thermal stability. Under near-ambient conditions of 1.6 mbar CO2 gas pressure and 175 K sample temperature, CO2 molecules are not adsorbed on the pristine graphene, but are adsorbed on the oxygen-functionalized graphene surface. The increase in the adsorption energy of CO2 on the oxygen-functionalized graphene surface is supported by first-principles calculations with the van der Waals density functional (vdW-DF) method. The adsorption of CO2 on the oxygen-functionalized graphene surface is enhanced by both the electrostatic interactions between the CO2 and the epoxy group and the vdW interactions between the CO2 and graphene. The detailed understanding of the interaction between CO2 and the oxygen-functionalized graphene surface obtained in this study may assist in developing guidelines for designing novel graphene-based catalysts.

Draft Genome Sequences of Two Antimicrobial Compound-Producing Strains of Bacillus Species, TM-R and SY1-1.

Two antimicrobial compound-producing strains of Bacillus species, namely, TM-R and SY1-1, have been identified previously. In this study, we report the draft genome sequences of these strains and demonstrate the presence of 12 and 14 gene clusters for secondary metabolite biosynthesis in TM-R and SY1-1, respectively.

[A Preliminary Study of Optimal Imaging Acquisition Parameters for Fiducial Markers in Liver Stereotactic Body Radiotherapy].

In liver stereotactic body radiotherapy (SBRT) using fiducial markers, the accuracy of automatic image recognition of fiducial markers is important, and the imaging dose cannot be neglected in image-guided radiotherapy. Optimal imaging parameters of fiducial markers were investigated for automatic image recognition and imaging dose. We investigated automatic recognition with fiducial markers of different shapes and sizes. In addition, the optimum imaging conditions were examined based on the automatic recognition when the presence or absence of a filter, focal spot size, and phantom thickness were altered using the fiducial markers with a high automatic recognition. The results for different shapes and sizes of fiducial markers showed that larger markers were recognized more automatically, whereas shorter markers were recognized in the correct position. By using the filter, we were able to reduce the imaging dose by one third or one half compared to the case without the filter. The results for the focal spot size showed that using a larger size resulted in higher automatic recognition accuracy than using a smaller size. For the relationship between the automatically recognized imaging conditions and the air kerma when the phantom thickness was altered, it was necessary to keep the tube current-time product constant and increase the tube voltage in order to avoid poor recognition accuracy. The parameters we proposed are effective in shortening the treatment time and reducing the imaging dose because they allow us to acquire images with low doses and high accuracy of automatic recognition.

Optimization of injection dose in 18F-FDG PET/CT based on the 2020 national diagnostic reference levels for nuclear medicine in Japan.

OBJECTIVE: Recently, the national diagnostic reference levels (DRLs) in Japan were revised as the DRLs 2020, wherein the body weight-based injection dose optimization in positron emission tomography/computed tomography using 18F-fluoro-2-deoxy-D-glucose (18F-FDG PET/CT) was first proposed. We retrospectively investigated the usefulness of this optimization method in improving image quality and reducing radiation dose. METHODS: A total of 1,231 patients were enrolled in this study. A fixed injection dose of 240 MBq was administered to 624 patients, and a dose adjusted to 3.7 MBq/kg body weight was given to 607 patients. The patients with body weight-based injection doses were further divided according to body weight: group 1 (≤ 49 kg), group 2 (50-59 kg), group 3 (60-69 kg), and group 4 (≥ 70 kg). The effective radiation dose of FDG PET was calculated using the conversion factor of 0.019 mSv/MBq, per the International Commission on Radiological Protection publication 106. Image quality was assessed using noise equivalent count density (NECdensity), which was calculated by excluding the counts of the brain and bladder. The usefulness of the injection dose optimization in terms of radiation dose and image quality was analyzed. RESULTS: The body weight-based injection dose optimization significantly decreased the effective dose by 11%, from 4.54 ± 0.1 mSv to 4.05 ± 0.8 mSv (p < 0.001). Image quality evaluated by NECdensity was also significantly improved by 10%, from 0.39 ± 0.1 to 0.43 ± 0.2 (p < 0.001). In no case did NECdensity deteriorate when the effective dose was decreased. In group 1, the dose decreased by 32%, while there was no significant deterioration in NECdensity (p = 0.054). In group 2, the dose decreased by 17%, and the NECdensity increased significantly (p < 0.01). In group 3, the dose decreased by 3%, and the NECdensity increased significantly (p < 0.01). In group 4, the dose increased by 14%, but there was no significant change in the NECdensity (p = 0.766). CONCLUSION: Body weight-based FDG injection dose optimization contributed to not only the reduction of effective dose but also the improvement of image quality in patients weighing between 50 and 69 kg.

Antifungal spectrum characterization and identification of strong volatile organic compounds produced by Bacillus pumilus TM-R.

To obtain biocontrol agents for suppression of food-deteriorating fungi during storage of agricultural products, bacteria producing volatile organic compounds (VOCs) with strong antifungal activity were screened and isolated from various environmental samples. Among 136 bacterial isolates, strain TM-R showed the strongest and broadest antifungal activity. Based on physiological and genetical characterization, the bacterium was identified as Bacillus pumilus. The effects of VOCs produced by the bacterium, which was grown on four types of agar media (nutrient, Trypto-Soya, Luria-Bertani, and TM Enterprise), were examined against six species of fungi (Alternaria alternata, Aspergillus niger, Cladosporium cladosporioides, Curvularia lunata, Fusarium oxysporum, and Penicillium italicum) in both small- and large-scale tests (plate and 12-L tests, respectively). In the plate test, the bacterium markedly suppressed the mycelial growth of five fungi (Alternaria alternata, Cladosporium cladosporioides, Curvularia lunata, F. oxysporum, and P. italicum) but promoted the growth of Aspergillus niger. In the 12-L test, the degree of growth inhibitiondecreased; however, the bacterium grown on TMEA still exhibited the strongest inhibition, especially against P. italicum (growth inhibition rate of 93%). Surprisingly, the growth of Aspergillus niger was promoted even more strongly (-36%) by the bacterium on TMEA than in the plate test (-9%). Twenty-two of 32 VOCs detected by GC-MS were identified using three databases (NIST 2011, AromaOffice, and AroChemBase). The species and concentration of detected VOCs differed greatly among growth media. To identify causative antifungal VOCs, we estimated the correlation between growth inhibition of P. italicum by the bacterium grown on each of the four media vs. the relative abundance of individual VOCs. As a result, four VOCs (methyl isobutyl ketone, ethanol, 5-methyl-2-heptanone, and S-(-)-2-methylbutylamine) were determined to be the predominant antifungal VOCs. To the best of our knowledge, this study is the first to specify causative antifungal VOCs using such an approach.

Temporal trends in PCB concentrations in mussels collected from areas affected by the Great East Japan Earthquake and Tsunami.

In the Great East Japan Earthquake of 11 March 2011, a magnitude 9.0 earthquake and accompanying tsunami struck the Tohoku region of Japan. The tsunami washed away old equipment containing polychlorinated biphenyls (PCBs) stored in the region's factories, and these PCBs may have leaked out of their casings into the marine environment. In this study, we evaluate marine PCB contamination by comparing mussels collected before (in 2005) and after (June 2011) the tsunami. PCB contamination levels were significantly elevated in mussel samples collected after the tsunami in June 2011 (3 months after the tsunami). This indicates that PCBs (specifically, formulation KC-400) leaked out of old equipment swept away by the tsunami and accumulated in mussels. PCBs were estimated to have an environmental half-life (EHL) in mussels of 4 months. Our results show that an earthquake and subsequent tsunami can cause elevated PCB contamination in the marine environment.

Development of a novel scheme for rapid screening for environmental micropollutants in emergency situations (REPE) and its application for comprehensive analysis of tsunami sediments deposited by the great east Japan earthquake.

The tsunami triggered by the Great East Japan Earthquake of March 2011, the strongest quake ever recorded in Japan, deposited tsunami sediments along the coastline of the affected area. Because the sediments contained a wide variety of hazardous chemicals, including organic micropollutants, a method for rapidly evaluating the environmental and human health risks of such chemicals is necessary. For this purpose, we propose a novel three-step scheme designated "rapid screening for environmental micropollutants in emergency situations (REPE)". In the first step, samples are subjected to target screening analysis using an automated identification and quantification system (TSA-AIQS) involving gas chromatography mass spectrometry (GC-MS). In the second step, the chemicals detected by TSA-AIQS analysis are quantified precisely by conventional target analysis. The third step is risk assessment of the target chemicals. TSA-AIQS analysis of the tsunami sediments detected 63 substances, including polycyclic aromatic hydrocarbons (both native and alkylated PAHs) at high concentrations. These PAHs were precisely quantified by target analysis, and the concentrations were used to assess the health risks posed by oral intake, which were found to be negligible. Our results suggest that the REPE scheme will be useful for rapid, comprehensive screening and risk assessment in emergency situations.

Inhibitory effect of branched-chain amino acid granules on progression of compensated liver cirrhosis due to hepatitis C virus.

BACKGROUND: A phase II randomized controlled trial was conducted in patients with compensated liver cirrhosis to investigate the inhibitory effect of branched-chain amino acid (BCAA) granules for oral use (TK-98) on disease progression. METHODS: Patients who had compensated liver cirrhosis due to hepatitis C virus with baseline serum albumin levels between 3.6 and 4.5 g/dl were assigned to the TK-98 group, which was treated with BCAA granules (TK-98) for 168 weeks, or to a control group (no treatment). RESULTS: No symptoms indicating decompensated cirrhosis, including ascites, edema, and hepatic encephalopathy were reported in either the TK-98 or control group during the study observation period. Hepatocellular carcinoma (HCC) was noted in eight of the 39 patients studied, and of these three received TK-98 (15.8%) and five were untreated (25.0%). A time-to-event analysis for the effect of BCAA therapy on development of HCC revealed no statistically significant differences between the two groups. However, an additional analysis of data from a subgroup with a baseline serum albumin level of <4.0 g/dl showed that the incidence of HCC was likely to be lower in BCAA-treated patients. CONCLUSIONS: BCAA may inhibit hepatic carcinogenesis in patients with compensated cirrhosis with a serum albumin level of <4.0 g/dl.

Variability and reliability of POP concentrations in multiple breast milk samples collected from the same mothers.

Risk assessment of infant using a realistic persistent organic pollutant (POP) exposure through breast milk is essential to devise future regulation of POPs. However, recent investigations have demonstrated that POP levels in breast milk collected from the same mother showed a wide range of variation daily and monthly. To estimate the appropriate sample size of breast milk from the same mother to obtain reliable POP concentrations, breast milk samples were collected from five mothers living in Japan from 2006 to 2012. Milk samples from each mother were collected 3 to 6 times a day through 3 to 7 days consecutively. Food samples as the duplicated method were collected from two mothers during the period of breast milk sample collection. Those were employed for POP (PCBs, DDTs, chlordanes, and HCB) analysis. PCB concentrations detected in breast milk samples showed a wide range of variation which was maximum 63 and 60% of relative standard deviation (RSD) in lipid and wet weight basis, respectively. The time course trend of those variations among the mothers did not show any typical pattern. A larger amount of PCB intake through food seemed to affect 10 h after those concentrations in breast milk in lipid weight basis. Intraclass correlation coefficient (ICC) analyses indicated that the appropriate sample size for good reproducibility of POP concentrations in breast milk required at least two samples for lipid and wet weight basis.

Photo-induced semimetallic states realised in electron-hole coupled insulators.

Using light to manipulate materials into desired states is one of the goals in condensed matter physics, since light control can provide ultrafast and environmentally friendly photonics devices. However, it is generally difficult to realise a photo-induced phase which is not merely a higher entropy phase corresponding to a high-temperature phase at equilibrium. Here, we report realisation of photo-induced insulator-to-metal transitions in Ta2Ni(Se1-xSx)5 including the excitonic insulator phase using time- and angle-resolved photoemission spectroscopy. From the dynamic properties of the system, we determine that screening of excitonic correlations plays a key role in the timescale of the transition to the metallic phase, which supports the existence of an excitonic insulator phase at equilibrium. The non-equilibrium metallic state observed unexpectedly in the direct-gap excitonic insulator opens up a new avenue to optical band engineering in electron-hole coupled systems.

Factors associated with the virological response of lamivudine-resistant hepatitis B virus during combination therapy with adefovir dipivoxil plus lamivudine.

BACKGROUND: The aim of this study was to investigate the factors associated with the response of lamivudine-resistant hepatitis B virus (HBV) during combination therapy with adefovir dipivoxil plus lamivudine. METHODS: Sixty-three patients with breakthrough hepatitis received a 10-mg once-daily dose of oral adefovir dipivoxil. RESULTS: The rates of undetectable serum HBV-DNA were 49.2% after 24 weeks, 61.9% after 48 weeks, and 67.2% after 72 weeks. The cumulative hepatitis B e antigen (HBeAg) loss rates in patients with alanine aminotransferase (ALT) levels of more than twice the upper limit of normal (ULN) were significantly higher than in patients with ALT less than twice the ULN (P = 0.0145). Multivariate analysis revealed that baseline ALT level (P = 0.003) and HBeAg status (P = 0.049) were associated with early virological response. CONCLUSIONS: Baseline ALT level was associated with HBeAg loss and seroconversion, and baseline ALT level and HBeAg status were associated with the virological response of lamivudine-resistant HBV during combination therapy with adefovir dipivoxil plus lamivudine.

Rapid and automated enumeration of viable bacteria in compost using a micro-colony auto counting system.

The micro-colony method was used to enumerate viable bacteria in composts. Cells were vacuum-filtered onto polycarbonate filters and incubated for 18 h on LB medium at 37 degrees C. Bacteria on the filters were stained with SYBR Green II, and enumerated using a newly developed micro-colony auto counting system which can automatically count micro-colonies on half the area of the filter within 90 s. A large number of bacteria in samples retained physiological activity and formed micro-colonies within 18 h, whereas most could not form large colonies on conventional media within 1 week. The results showed that this convenient technique can enumerate viable bacteria in compost rapidly for its efficient quality control.

Femtosecond to picosecond transient effects in WSe 2 observed by pump-probe angle-resolved photoemission spectroscopy.

Time-dependent responses of materials to an ultrashort optical pulse carry valuable information about the electronic and lattice dynamics; this research area has been widely studied on novel two-dimensional materials such as graphene, transition metal dichalcogenides (TMDs) and topological insulators (TIs). We report herein a time-resolved and angle-resolved photoemission spectroscopy (TRARPES) study of WSe2, a layered semiconductor of interest for valley electronics. The results for below-gap optical pumping reveal energy-gain and -loss Floquet replica valence bands that appear instantaneously in concert with the pump pulse. Energy shift, broadening, and complex intensity variation and oscillation at twice the phonon frequency for the valence bands are observed at time scales ranging from the femtosecond to the picosecond and beyond. The underlying physics is rich, including ponderomotive interaction, dressing of the electronic states, creation of coherent phonon pairs, and diffusion of charge carriers - effects operating at vastly different time domains.

Interferon lowers tumor recurrence rate after surgical resection or ablation of hepatocellular carcinoma: a pilot study of patients with hepatitis B virus-related cirrhosis.

BACKGROUND: Hepatocellular carcinoma (HCC) caused by hepatitis B virus (HBV) often recurs after surgical or medical treatment. METHODS: Eighty consecutive patients with HBV-positive cirrhosis and HCC who underwent potentially curative ablation for HCC were analyzed. Eleven patients received long-term interferon (IFN) therapy. HBV DNA was quantified at the time of HCC treatment. A DNA value of <6.0 log copies/ml was considered low. RESULTS: Initial DNA was low in 39 and high in 41 patients. HCC recurrence rates in the low DNA group and high DNA group were 46.9% and 82.6% at the fifth year, and 73.5% and 91.3% at the tenth year, respectively (P = 0.0103). Similarly, recurrence rates after treatment of HCC in the normal aspartate aminotransferase (AST) group (<38 IU/l, n = 42) and abnormal AST group (n = 38) were 50.6% and 84.0% at the fifth year, and 71.3% and 100% at the tenth year, respectively (P = 0.0003). Six of the 38 patients with abnormal AST, and 5 of 42 patients with normal AST, received IFN after confirmation of tumor ablation. In the subgroup of abnormal AST, tumor recurrence rates in the IFN and untreated groups were 16.7% and 37.9% at the end of the first year, 16.7% and 60.1% at the second year, and 16.7% and 83.4% at the third year, respectively (P = 0.0139). Multivariate analysis revealed that IFN significantly reduced the recurrence rate (hazard ratio = 0.21, P = 0.037) even after adjusting for background characteristics. CONCLUSIONS: IFN was inferred to decrease tumor recurrence after treatment of HCC in patients with HBV-related cirrhosis, especially in the subgroup with high AST.

Efficacy of interferon monotherapy in young adult patients with chronic hepatitis C virus infection.

BACKGROUND: Suppression of the progression to cirrhosis and hepatocellular carcinoma is important, especially for young hepatitis C virus (HCV)-infected patients. The aim of this study was to analyze the response to interferon (IFN) monotherapy in young HCV patients. METHODS: Between 1989 and 2002, 1021 anti-HCV-positive patients hospitalized at Toranomon Hospital received IFN monotherapy. Among these patients, 144 were < or =35 years of age, while the remaining 877 were 36-73 years old. We retrospectively identified 209 patients with known dates of blood transfusion (i.e., start of HCV infection) among the 1021 patients. IFN treatment lasted 6 months. RESULTS: HCV RNA level (P < 0.001), HCV genotype (P < 0.001), age (P < 0.001), and liver histology (P = 0.01) were identified as determinants of the response to IFN monotherapy in 1021 patients. Moreover, in patients with high viral load and genotype 1b, the sustained virological response (SVR) rate was significantly higher in those aged < or =35 years than in older patients (P < 0.001). In patients with genotype 1b with known date of blood transfusion, a longer duration of infection negatively influenced the SVR rate. In the 209 patients, multivariate analysis identified HCV RNA level (P < 0.001), age (P = 0.002), and duration of infection (P = 0.049) as determinants of SVR. CONCLUSIONS: The response of IFN monotherapy is better in patients aged < or =35 years than in older patients, probably because of mild stage histology, the effect of host-related factors, and shorter period of infection. Long-term IFN monotherapy may be suitable for young women who desire to become pregnant or those with anemia.

Determinants of serum ALT normalization after phlebotomy in patients with chronic hepatitis C infection.

BACKGROUND: Phlebotomy is performed to reduce excessive iron accumulation in hepatic tissue. We studied serum alanine aminotransferase (ALT) normalization rates and 50% reduction in initial serum ALT (ALT(50%) reduction rate) in patients with hepatitis C viral (HCV) infection and investigated the factors that influenced the response to phlebotomy therapy. METHODS: We evaluated 23 consecutive patients with HCV infection who underwent phlebotomy. Phlebotomy was performed a few times per week, then a few times per month, and 200-400 ml of blood was removed at each session, depending on the clinical response. During the course of therapy, hemoglobin (Hb), serum ALT, and ferritin levels were assessed monthly. RESULTS: In patients with Hb of less than 11 g/dl, the ALT(50%) reduction rate was 87.5%. In patients with a serum ferritin level of less than 10 g/dl the ALT(50%) reduction rate was 83.3%. In patients with Hb of less than 11 g/dl, the ALT normalization rate was 50%, and in those with a serum ferritin level of less than 10 g/dl, the ALT normalization rate was 41.7%. Multivariate analysis identified ALT less than 100 IU/l at the start of phlebotomy as an independent factor associated with ALT normalization. Of the 7 patients who showed no response to phlebotomy, 85.7% were obese (body mass index > or =25 kg/m(2)), and 40% showed more than 30% steatosis on liver histology. The cumulative ALT normalization rate in relation to the total volume of blood loss was 43.9% with a blood less or more than 3 l, and thus was optimal above 3 l. CONCLUSIONS: Although the sample number was relatively small, the results of our study suggest that phlebotomy is effective therapy for HCV patients who are nonobese, show little or no steatosis on liver histology, and have a baseline serum ALT level of less than 100 IU/l.

Cost-effectiveness of radiofrequency ablation and surgical therapy for small hepatocellular carcinoma of 3cm or less in diameter.

BACKGROUND: Cost-effectiveness of radiofrequency ablation (RFA) was assessed in treatment of hepatocellular carcinoma (HCC). PATIENTS AND METHODS: During 5 years, 153 patients with HCC of 3cm or less received RFA, and 60 underwent surgery. Judgment after RFA therapy was classified into three grades: residual tumor (grade 1), necrotic area with a less safety margin of 5mm (grade 2), and necrosis with a safety margin of 5mm in all directions (grade 3). RESULTS: Local recurrence rates after RFA and surgery were 7.9% and 0% at the third year. The rates in patients with grades 2 and 3 after RFA were 18.7% and 1.2% at the third year, respectively (P=0.0005). Among 91 patients with grades 1 and 2 necrosis after initial therapy, 52 received additional ablation. Although local recurrence rate was 24.9% in 39 patients without additional therapy, the rates after therapy repetition were 10.9% in 21 patients with eventual grade 2 necrosis, and 0% in 31 patients with grade 3 (P=0.038). Median costs of single RFA, repeated RFA, and surgery were yen849,900, yen1,086,000, and yen1,745,100, respectively. Additional ablation reduced local recurrence by 20.7% at the cost of yen236,100. CONCLUSION: Cost-effectiveness of RFA in the treatment of small HCC was superior to that of surgery.

Optically detecting the edge-state of a three-dimensional topological insulator under ambient conditions by ultrafast infrared photoluminescence spectroscopy.

Ultrafast infrared photoluminescence spectroscopy was applied to a three-dimensional topological insulator TlBiSe2 under ambient conditions. The dynamics of the luminescence exhibited bulk-insulating and gapless characteristics bounded by the bulk band gap energy. The existence of the topologically protected surface state and the picosecond-order relaxation time of the surface carriers, which was distinguishable from the bulk response, were observed. Our results provide a practical method applicable to topological insulators under ambient conditions for device applications.

Exposure assessment of organophosphorus and organobromine flame retardants via indoor dust from elementary schools and domestic houses.

To assess the exposure of flame retardants (FRs) for school-children, organophosphorus flame retardants and plasticizers (PFRs) and organobromine flame retardants (BFRs) were determined in the indoor dust samples collected from elementary schools and domestic houses in Japan in 2009 and 2010. PFRs were detected in all the dust samples analyzed and the highest concentration of total PFRs was thousand-fold higher than that of BFRs. Among the PFRs, tris(butoxyethyl)phosphate (TBOEP) showed the highest concentration with a median (med.) of 270,000 ng g(-1) dry weight (3700-5,500,000 ng g(-1) dry weight), followed by tris(methylphenyl)phosphate (TMPPs)>triphenyl phosphate (TPHP)=tris(1,3-dichloro-2-propyl)phosphate (TDCIPP)=tris(2-chloroisopropyl)phosphate (TCIPP)=tris(2chloroethyl)phosphate (TCEP)>ethylhexyl diphenyl phosphate (EHDPP). Significantly higher concentrations of TBOEP, tri-n-butyl phosphate (TNBP), TPHP, TMPPs, and total-PFRs were found in dust samples from elementary schools than from domestic houses. It might be due to that higher concentrations of TBOEP (as leveling agent) were detected from the floor polisher/wax products collected in those elementary schools. On the other hand, significantly higher concentrations of TCEP, TCIPPs, and total chloroalkyl-PFRs were found in domestic houses than in elementary schools. Exposure assessments of PFRs via indoor dust from elementary schools and domestic houses were conducted by calculating the hazard quotient (HQ). Among PFRs, HQs for TBOEP exceeded 1 (higher than reference dose: RfD) and its highest value was 1.9. To reduce the intake of TBOEP by school-children, it is recommended that the use of floor polisher/wax containing TBOEP be reduced in schools.

Adequate timing of ribavirin reduction in patients with hemolysis during combination therapy of interferon and ribavirin for chronic hepatitis C.

BACKGROUND: Hemolytic anemia is one of the major adverse events of the combination therapy of interferon and ribavirin. Because of ribavirin-related hemolytic anemia, dose reduction is a common event in this therapy. In this clinical retrospective cohort study we have examined the suitable timing of ribavirin reduction in patients with hemolysis during combination therapy. METHODS: Thirty-seven of 160 patients who had HCV-genotype 1b, had high virus load, and received 24-week combination therapy developed anemia with hemoglobin level <10 g/dl or anemia-related signs during therapy. After that, these 37 patients were reduced one tablet of ribavirin (200 mg) per day. After reduction of ribavirin, 27 of 37 patients could continue combination therapy for a total of 24 weeks (group A). However, 10 of 37 patients with reduction of ribavirin could not continue combination therapy because their <8.5 g/dl hemoglobin values decreased to or anemia-related severe side effects occurred (group B). We assessed the final efficacy and safety after reduction of ribavirin in groups A and B. RESULTS: A sustained virological response (SVR) was 29.6% (8/27) in group A and 10% (1/10) in group B, respectively. A 34.4% (12/27) of SVR + biological response in group A was higher than 10% (1/10) in group B ( P = 0.051), with slight significance. With respect to hemoglobin level at the time of ribavirin reduction, a rate of continuation of therapy in patients with > or =10 g/dl hemoglobin was higher than that in patients with <10 g/dl ( P = 0.036). CONCLUSIONS: Reduction of ribavirin at hemoglobin level > or =10 g/dl is suitable in terms of efficacy and side effects.