Screening and characterization of yeasts for xylitol production

AIMS

To discover novel naturally occurring xylitol producing yeast species with potential for industrial applications.

METHODS AND RESULTS

Exactly 274 strains were cultivated on both solid and liquid screening medium with xylose as the sole carbon resource. Five strains were selected on the basis of significant growth and high degree of xylose assimilation. Their phylogenetic position was confirmed by the PCR-RFLP and sequence analysis of the D1/D2 domain of the 5' end of the large subunit rDNA gene (5'-LSU rDNA). Enzymatic analysis was conducted to compare xylose metabolism in each strain. Candida guilliermondii Xu280 and Candida maltosa Xu316 were found to have high xylose consumption rates and xylitol yields in the batch fermentation under micro-aerobic condition. The effect of the different media with high initial xylose concentration on biosynthesis of xylitol by both strains was investigated.

CONCLUSIONS

We have identified Candida spp. strains, which exhibit high levels of xylitol production from xylose suggesting that these may have potential for industrial applications.

SIGNIFICANCE AND IMPACTS OF THE STUDY

Microbial species are of importance for xylitol production. Xylitol production involves complicated metabolic regulation including xylose transport, production of key enzymes and cofactor regeneration. Thus, screening of naturally occurring xylose-utilizing micro-organisms is a viable and effective mean to obtain xylitol producing organisms with industrial application. Moreover, the research on selected strains will contribute to a better understanding of regulatory properties of xylose metabolism in different yeasts.

Cloning and molecular characterization of a gene coding D-xylulokinase (CmXYL3) from Candida maltosa

AIMS

To clone and identify a gene (CmXYL3) coding D-xylulokinase from Candida maltosa Xu316 and understand its physiological function.

METHODS AND RESULTS

Based on the conserved regions of the known D-xylulokinase-encoding genes, a pair of degenerate primers was designed to clone the CmXYL3 gene from C. maltosa Xu316. The coding region and sequences flanking the CmXYL3 gene were obtained by PCR-based DNA walking method. Southern blotting analysis suggested that there is a single copy of the CmXYL3 gene in the genome. The open reading frame starting from ATG and ending with TAG stop codon encoded 616 amino acids with a calculated molecular mass of 68889.743 Da. The CmXYL3 gene under the control of the GPD1 promoter was heterologously expressed in Saccharomyces cerevisiae deficient in D-xylulokinase (deltaScXKS1::LEU2) activity, and restored growth on D-xylulose. The specific activity of D-xylulokinase varied during xylose fermentation and was correlated with aeration level. After growth on different pentoses and pentitols as sole carbon sources, the highest specific activity of D-xylulokinase was observed on D-xylose.

CONCLUSIONS

The CmXYL3 gene isolated from C. maltosa Xu316 encodes a novel D-xylulokinase that plays a pivotal role in xylulose metabolism.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that describes the isolation and cloning of D-xylulokinase gene (CmXYL3) from C. maltosa Xu316. D-xylulokinase is pivotal for growth and product formation during xylose metabolism. Better understanding of the biochemical properties and the physiological function of D-xylulokinase will contribute to optimizing fermentation conditions and determining the strategies for metabolic engineering of C. maltosa Xu316 for further improvement of xylitol yield and productivity.

Phase I study of ABT-751 in combination with CAPIRI (capecitabine and irinotecan) and bevacizumab in patients with advanced colorectal cancer

13553

Background: ABT-751 (A) is an orally (PO) bioavailable sulfonamide with antimitotic properties. We are performing a non-randomized phase I/II dose-escalation study of A in combination with capecitabine (C), irinotecan (I) and bevacizumab (B) to define the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics (PK) in patients with advanced colorectal cancer (1st or 2nd line). Methods: Patients are treated with A QD for 7d (lead-in) and then begin 21-d cycles of treatment with A (QD) and C (BID) d1–14 PO, I d1 IV, and B d1 IV. Dose escalation started at dose level (DL) 1 at A 150 mg, I 200 mg/m2, and C 1600 mg/m2 (total daily dose) and escalated to full dose CAPIRI (I 250 mg/m2, and C 2000 mg/m2) for DL2. B was then added as standard of care at 7.5 mg/kg for DL2b (and later, DL1b). Blood samples were collected for pharmacogenomics (PG), pharmacodynamics (PD), steady-state PK of A and A metabolites when administered alone or in combination with C, I, and B, and PK of I and I metabolites. Serial dynamic contrast MRI’s, before and after the ABT-751 monotherapy lead-in period, are being performed in a subset of subjects. Results: Eight patients have been treated at dose levels 1 (3), 2 (2), and 2b (3). One patient on DL2 experienced g3 transaminitis and another on DL2b had F&N which were dose-limiting. Dose level 1 is being expanded to 6 patients, now with B (DL1b). Other g3/4 toxicities have included g4 neutropenia (1 subject DL2, 1 DL2b). The formation of A glucuronide appears decreased during combination therapy (see table). I PK, PD, and PG samples were collected and analysis is pending. Of 8 subjects, there have been 4 PD and 4 SD after 2 cycles. Conclusions: The combination therapy of A 150 mg and 20% dose-reduced CAPIRI appears well-tolerated. Patient accrual continues at DL1b. [Table: see text]

No significant financial relationships to disclose.

Extended effects of human papillomavirus 16 E6-specific short hairpin RNA on cervical carcinoma cells

Most cervical carcinomas express high-risk human papillomavirus (HPV) E6 and E7 oncogenes. Small interfering RNA can mediate sequence-specific inhibition of gene expression in mammalian cells. To find a most effective short hairpin RNA (shRNA) for HPV16 E6 messenger RNA (mRNA) and investigate the extended effects of the HPV16 E6 shRNA on cervical carcinoma cells, we stably transfected SiHa cells with four shRNA expression vectors (E6A-D). HPV16 E6A shRNA was found to be the most efficient in our study, which caused the reduction of HPV16 E6 mRNA to 10% in SiHa cells but did not reduce HPV18 E6 mRNA expression in HeLa cells. We subsequently demonstrated that E6A could stably express shRNA and effectively reduce HPV16 E6 and E7 viral genes expression in SiHa cells for more than 4 months. After E6 and E7 repression, there was a dramatic accumulation of p53, p21, and hypophosphorylated pRb proteins in cells. Furthermore, cell proliferation, colony formation ability, tumorigenicity, and in vitro cell invasive capability were suppressed substantially in E6A-transfected cells. These results suggest that the use of shRNA expression vector may be a potential approach for the treatment of persistent HPV infection and HPV-positive cervical carcinoma.

Electrolytic degradation of biorefractory organics and ammonia in leachate from bioreactor landfill

Electrochemical oxidation was applied to treat the effluent from bioreactor landfill with leachate recirculation, characterised as poor biodegradability and high NH3-N concentration. In this study, the effluent was electrolysed in a batch reactor with Ti/TiO2-IrO2-RuO2 anode and stainless steel cathode. The oxidation of dissolved organic matter (DOM) during electrolysis was evaluated based on the evolution of molecular weight grade, hydrophilic fractionation (humic acid, fulvic acid and hydrophilic fractions), specific ultraviolet absorbance (SUVA254) and AOX. The impact of the initial NH3-N concentration on the oxidation was discussed. The results showed that at a current density of 100 mA/cm2, electrolysis time of 1.5 h and electrode gap of 1 cm, NH3-N with an initial concentration of 1.2 g/L could be completely eliminated and 56% of COD with an initial concentration of 1.2 g/L could be removed, which illustrated that the electrolysis-produced chlorine preferentially oxidised ammonia. The electrolysis mainly resulted in the degradation of humic substances and other high molecular DOM, followed by the increase of BOD/COD ratio and decline of SUVA254 of the leachate. The current efficiencies for COD and ammonia oxidation gradually decreased during the electrolysis, with the latter obviously higher than the former. At the optimal electrolysis time of 1.5 h, NH3-N could be totally removed and the BOD/COD ratio could be enhanced to 0.3, which was also favourable to control the AOX at a reasonable level.

Optimum control of the Hemopump as a left-ventricular assist device

A general framework for designing an optimum control strategy for the Hemopump is described. An objective function was defined that includes four membership functions, each constructed based on the desired values of one of the four members: stroke volume, mean left atrial pressure, aortic diastolic pressure and mean pump rotation speed. The Hemopump was allowed to operate either at a constant speed or at two different speeds during a cardiac cycle. The goal was to maximise the objective function by varying the magnitude and timing of the pump speed. Using a canine circulatory model, it was demonstrated that, in general, different cardiac conditions or different clinical objectives require different operation parameters. For example, when a left ventricle with minor ischaemia was simulated, and the main objective was to increase stoke volume, the objective function was maximised, from a value of 0.877 when the pump was off, to 0.946 when the pump was operated at speed 2 (18 500 revolutions min(-1)). On the other hand, for a severely ischaemic heart, the optimum pump speed became speed 3 (20 000 revolutions min(-1)), which maximized the objective function to 0.943 (from 0.707 when the pump was off). The results also suggest that it is more beneficial to operate the Hemopump at two different speeds during a cardiac cycle (a higher speed during systole and early diastole, and a lower speed during late diastole) than to maintain a constant speed throughout the cardiac cycle.

Removal of ocular artifacts from electro-encephalogram by adaptive filtering

The electro-encephalogram (EEG) is useful for clinical diagnosis and in biomedical research. EEG signals, however, especially those recorded from frontal channels, often contain strong electro-oculogram (EOG) artifacts produced by eye movements. Existing regression-based methods for removing EOG artifacts require various procedures for preprocessing and calibration that are inconvenient and time-consuming. The paper describes a method for removing ocular artifacts based on adaptive filtering. The method uses separately recorded vertical EOG and horizontal EOG signals as two reference inputs. Each reference input is first processed by a finite impulse response filter of length M (M = 3 in this application) and then subtracted from the original EEG. The method is implemented by a recursive least-squares algorithm that includes a forgetting factor (lambda = 0.9999 in this application) to track the non-stationary portion of the EOG signals. Results from experimental data demonstrate that the method is easy to implement and stable, converges fast and is suitable for on-line removal of EOG artifacts. The first three coefficients (up to M = 3) were significantly larger than any remaining coefficients.

Conjugation metabolism of acetaminophen and bilirubin in extrahepatic tissues of rats

An anhepatic rat model was used to explore the extrahepatic conjugating metabolism of acetaminophen and serum bilirubin. The recovery of glucuronide- and sulfate-acetaminophen was 47.5% in normal control and 13.4% in model rats in the urine collected for 6 h after administration of acetaminophen 20 mg kg(-1). Following the increase of acetaminophen dose to 150 mg kg(-1), the recovery of urinary glucuronide-acetaminophen increased by 53.9% in normal control; but it decreased by 36.4% in model rats. In contrast to normal control, the pretreatment with phenobarbital did not affect acetaminophen and its metabolite levels in plasma and urine in model rats. After the establishment of anhepatic model the serum direct bilirubin rose dramatically. Urinary bilirubin test was positive in model rats, but not in normal control. No changes were observed in serum total bilirubin and ratio of direct/total bilirubin after the pretreatment with ranitidine or phenobarbital 50 mg kg (-1), i.p. for 5 days in model rats. The results indicate that the glucuronide- and sulfate-acetaminophen formed in the extrahepatic tissues of model rats is 28.2% of normal control, serum free bilirubin can be transformed into conjugated bilirubin in extrahepatic tissues, and the regulation mechanism of phase II conjugating enzymes is different between the hepatic and extrahepatic tissues.

Condition, prolonged swimming performance and muscle metabolic capacities of cod Gadus morhua

This study evaluated the link between swimming endurance and condition of Atlantic cod Gadus morhua that had been fed or starved during the 16 weeks preceding the tests, and assessed whether muscle metabolic capacities explain such links. The condition factor [(somatic mass x fork length(-3))x100] of starved cod was 0.54+/-0.1 whereas that of fed cod was 0.81+/-0.1. In white and red muscle, we measured four glycolytic enzymes: phosphofructokinase (PFK), pyruvate kinase (PK), creatine kinase (CK) and lactate dehydrogenase (LDH), two mitochondrial enzymes: cytochrome c oxidase (CCO) and citrate synthase (CS), a biosynthetic enzyme, nucleoside diphosphate kinase (NDPK), glycogen and protein levels and water content. Muscle samples were taken at three positions along the length of the fish; starvation affected the metabolic capacities of white muscle more than those of red muscle. The levels of glycolytic enzymes and glycogen changed more in white than red muscle during starvation. Both in fed and starved cod, muscle metabolic capacities varied with position along the fish; starvation reduced this longitudinal variation more in white than red muscle. In white muscle of fed cod, the glycolytic enzyme levels increased from head to tail, while in starved cod this longitudinal variation disappeared. In red muscle mitochondrial enzyme levels were highest in the caudal sample, but fewer differences were found for glycolytic enzymes. Swimming endurance was markedly affected by fish condition, with starved fish swimming only 30% of the time (and distance) of fed fish. This endurance was closely linked with the number of burst-coast movements during the test and the activity of CCO and LDH in white muscle. The number of burst-coast movements was significantly linked with condition factor and PFK activity in caudal red muscle and gill arch mass. Our data indicated that cod use both glycolytic and oxidative capacities to support endurance swimming. Furthermore, swimming endurance is linked with the metabolic capacities of red and white muscle.

Screening of pyruvate-producing yeast and effect of nutritional conditions on pyruvate production

AIMS

To find a yeast strain that can overproduce pyruvate and to investigate the effect of nutrients on pyruvate production.

METHODS AND RESULTS

Trichosporon cutaneum PD70, a yeast strain that can overproduce pyruvate, was isolated from shake-flask cultures of 132 yeast strains. Pyruvate was measured by the HPLC or DNP method (see Materials and methods). Pyruvate production reached approximately 30.0 +/- 1.0 g l(-1) in basal fermentation medium. Different nutrient supplements had great effects on pyruvate production. Some of the conditions that gave the highest yield are described.

CONCLUSIONS

Exogenous thiamine supplement caused a decrease in pyruvate yield. Some amino acids, such as L-arginine, L-isoleucine and L-valine, caused a minor increase in pyruvate yield. Soybean peptone was the most suitable nitrogen source for pyruvate production. A glucose concentration of 15% in fermentation medium gave the highest yield (34.6 g l(-1)) and the highest yield against consumed glucose (0.429 g g(-1)).

SIGNIFICANCE AND IMPACT OF THE STUDY

Nutrients have significant impacts on pyruvate production. As a pyruvate overproducing yeast strain independent of exogenous vitamins or amino acids, T. cutaneum PD70 provides an advantage for commercial pyruvate production.

Simulation study of the Hemopump as a cardiac assist device

A dynamic model was developed for a Hemopump that withdraws blood from the left ventricle and discharges it to the aorta through a miniature axial-flow pump. Incorporation of the Hemopump model in a previously established model for the canine circulatory system enabled the effects of the Hemopump on various haemodynamic variables of the circulatory system to be studied, and the benefit of the Hemopump to the failing heart was investigated. In addition, the influence of the physiological status of the right ventricle on the Hemopump performances was examined, and the synchronous and non-synchronous operations of the Hemopump were compared. Results verified that the Hemopump assists the failing heart by increasing the oxygen supply, while reducing the oxygen consumption of the heart through a reduction in the workload of the left ventricle. These beneficial effects were enhanced when the pump's rotation speed was increased. When pump speed was increased from 17,000 to 23,000 revolutions min-1, the oxygen supply increased 101%, and the oxygen consumption decreased 60%. However, when the pump rotation speed was too high, the inflow to the pump could be impaired and the pump performance could be negatively affected. Predications from the model were in good agreement with the results previously obtained in animal experiments and in vitro measurements.

Phenacetin O-deethylation in extrahepatic tissues of rats

Phenacetin O-deethylation is a marker reaction of CYP450 1A2 activity. The drug-metabolizing enzyme is constitutively expressed in liver. In this study, an in vivo rat model for assessment of extrahepatic metabolism was used to investigate phenacetin O-deethylation and the alterations in the disposition of phenacetin due to the loss of liver function. Rats were divided into the model and normal control groups. The model was established according to our previously described method. The concentrations of phenacetin and its major metabolites acetaminophen, glucuronate-acetaminophen and sulfate-acetaminophen in plasma and urine were determined by HPLC. 30 min after intravenous administration of 0.16% phenacetin 10 mg x kg(-1), plasma acetaminophen in the model group was only 3.6% of that in the control group (0.09+/-0.04 microg x mL(-1) vs 2.49+/-0.85 microg x mL(-1), n = 8). 30 min after intragastric injection of 0.4% phenacetin 30 mg x kg(-1), plasma acetaminophen formation was very slight, about 8.6% of plasma phenacetin in the model group (0.74+/-0.43 microg x mL(-1) acetaminophen vs 8.57+/-8.42 microg x mL(-1) phenacetin) and 6.8% in the control group (1.06+/-0.59 microg x mL(-1) acetaminophen vs 15.47+/-7.21 microg x mL(-1) phenacetin, n = 8); no significant differences were observed in plasma phenacetin, total acetaminophen and the ratio of acetaminophen to phenacetin between control and model groups. In the urine collected for 3 h after intravenous administration of 0.16% phenacetin 10 mg x kg(-1), the total recovery of acetaminophen (as free, glucuronate- and sulfate-acetaminophen ) in the model group was 4.6% of that in the control group (4.47+/-4.27 microg vs 96.63+/-8.50 microg, n = 6), but phenacetin recovery in the model group was 9 times higher than that in the control group (15.03+/-17.72 microg vs 1.66+/-0.50 microg). The results indicate that phenacetin O-deethylation in the extrahepatic tissues and the first-pass metabolism of the probe compound seem to be negligible in rats, but the renal excretion of phenacetin, as a compensation, dramatically increases in model rats.

Novel ultrasonic fusion imaging method based on cyclic variation in myocardial backscatter

Quantitative ultrasonic tissue characterisation of the myocardium based on integrated backscatter (IB) has the potential of becoming an effective method for detecting and evaluating myocardial ischaemia. To facilitate IB-based clinical applications, a new imaging method has been developed that combines the anatomical information of a B-mode image with the contractile performance of a selected myocardial region. To produce such a fusion image, a region of interest (ROI) in a B-mode cardiac image was first selected by the user. Algorithms for detection of the endocardium and epicardium were developed, and the resulting mean distance between the computer-detected curve and the manually traced curve was 0.83mm for the endocardium and 0.58mm for the epicardium. The cyclic variation of IB (CVIB) of each myocardial tissue element within the ROI was then calculated over one cardiac cycle. Finally, a grey-scale B-mode image at the end of diastole was displayed as a still image, and the pixels representing the myocardial tissue in the ROI colour-coded according to the corresponding CVIB over the past heart cycle. Both the B-mode image and the colour-coded region were refreshed (up-dated) at the next end-of-diastole. Preliminary results from normal (CVIB= 10-12dB) and ischaemic (CVIB = 5-7 dB) canine hearts are presented that demonstrate the utility of this new imaging method.

Overexpression of Pti5 in tomato potentiates pathogen-induced defense gene expression and enhances disease resistance to Pseudomonas syringae pv. tomato

The tomato Pti5 gene encodes a pathogen-inducible ethylene response element-binding protein-like transcription factor that interacts with the disease resistance gene product Pto. Overexpression of Pti5 or Pti5-VP16, a translational fusion with a constitutive transcriptional activation domain, in tomato enhanced resistance to Pseudomonas syringae pv. tomato. Constitutive expression of Pti5 or Pti5-VP16 did not affect the basal level of pathogenesis-related gene expression, but it accelerated pathogen-induced expression of GluB and Catalase. The results demonstrate a positive role of Pti5 in defense gene regulation and disease resistance and suggest that a pathogen-activated posttranscriptional regulatory step is necessary for the pathogen induction of the defense gene expression.

[Study on expression of caspase-3 and bcl-2 proteins and their relations with cell apoptosis and proliferation in non-Hodgkin's lymphoma]

OBJECTIVE

To explore the possible roles of caspase-3 and bcl-2 proteins in the development and progression of non-Hodgkin's lymphoma (NHL) and their relationship.

METHODS

TdT-mediated dUTP nick end labeling (TUNEL) and immunohistochemistry were used to study cell apoptosis and expression of proliferating cell nuclear antigen (PCNA), caspase-3 and bcl-2 in 119 NHL cases.

RESULTS

The caspase-3 and bcl-2 positive rates were 86.6% (103/119) and 53.8% (64/119) respectively. Contrasting expression of these two proteins were found in reactive and malignant lymphoid tissues: In reactive lymphoid follicles, caspases-3 exhibited strong immunoactivity in cells located in germinal centers but not in mantle zone lymphocytes, whereas bcl-2 exhibited strong immunoactivity in mantle zone lymphocytes but not in cells located in germinal centers, and in neoplastic follicles, caspase-3 was negatively or weakly expressed, whereas bcl-2 was often positively expressed. In B cell lymphomas, the high grade group had a higher caspase-3 immunointensity and a lower bcl-2 immunointensity than the low grade group (P < 0.01). Apoptotic index correlated positively with expression of caspase-3 (r = 0.512, P < 0.01) and inversely with expression of bcl-2 (r = -0.436, P < 0.01). In addition, apoptotic index and proliferative index were positively related (r = 0.710, P < 0.01).

CONCLUSIONS

caspase-3 may participate in the regulation mechanism of lymphoma cell apoptosis. The contrasting expression of caspase-3 and bcl-2 is often seen in reactive and malignant lymphoid tissues, and it may indicate a close relationship between these two proteins in the regulation of lymphocyte proliferation kinetics.

The effects of catechol-O-methyltransferase inhibition on estrogen metabolite and oxidative DNA damage levels in estradiol-treated MCF-7 cells

Many of the major identified risk factors for breast cancer are associated with exposure to endogenous estrogen. In addition to the effects of estrogen as a growth factor, experimental and epidemiological evidence suggest that catechol metabolites of estrogen also contribute to estrogen carcinogenesis by both direct and indirect genotoxic mechanisms. O-Methylation catalyzed by catechol-O-methyltransferase (COMT) is a Phase II metabolic inactivation pathway for catechol estrogens. We and others have found that a polymorphism in the COMT gene, which codes for a low activity variant of the COMT enzyme, is associated with an increased risk of developing breast cancer; therefore, the goal of the current study was to investigate the role of decreased COMT activity on estrogen catechol levels and on oxidative DNA damage, as measured by 8-hydroxy-2'-deoxyguanosine (8-oxo-dG) levels. MCF-7 cells were pretreated with dioxin as a means to increase estrogen metabolism to catechol estrogens, then treated with estradiol (E2) +/- Ro 41-0960, a COMT-specific inhibitor. After extraction from culture medium, estrogen metabolites were separated using an high-performance liquid chromatography-electrochemical detection method. As expected, dioxin dramatically increased E2 oxidative metabolism, primarily to its 2-OH and 2-methoxy metabolites. The COMT inhibitor blocked 2-methoxy E2 formation. This was associated with increased 2-hydroxy E2 (2-OH E2) and 8-oxo-dG levels. In the presence of COMT inhibition, increased oxidative DNA damage was detected in MCF-7 cells exposed to as low as 0.1 microM E2, whereas in the absence of COMT inhibition, no increase in 8-oxo-dG was detected at E2 concentrations < or =10 microM. This study is the first to show that O-methylation of 2-OH E2 by COMT is protective against oxidative DNA damage caused by 2-OH E2, a major oxidative metabolite of E2.

Simultaneous measurement of sound velocity and wall thickness of a tube

A method for simultaneously measuring the sound propagation velocity and the thickness of each wall on the opposite sides of a tube is presented. The method uses a pair of ultrasound transducers to produce two reflected pulses from the outer and inner surfaces of the tube wall on the each side, and two transmitted pulses, one with and one without the tube sample between the two transducers. Using the time-domain analysis, sound velocity and wall thickness of the tube are determined from the time delays between the three pairs of ultrasound pulses, whereas using the frequency-domain analysis, phase velocity, group velocity, and wall thickness of the tube are determined from the phase differences between the three pairs of ultrasound pulses. Results of measurements on five tube samples are reported.

Comparative effect of dietary olive, safflower, and linseed oils on spontaneous liver tumorigenesis in C3H/He mice

In male C3H/He mice, which frequently develop spontaneous liver tumorigenesis, 5 wk of age and weighing about 20 g, the comparative effects on liver tumor incidence from the feeding of olive oil (OLI), safflower oil (SAF), and linseed oil (LIS) diets for 50 wk, the concentrations of total cholesterol (T-CHOL), triacylglycerol (TG), lipid peroxides in the plasma and liver, and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the plasma were examined. The changes in body weight and liver weight were not different among dietary groups. The number of mice bearing liver adenoma was greater in the SAF group than in the OLI and LIS groups. Liver carcinoma was observed in the SAF group, but not in the OLI and LIS groups. The concentrations of T-CHOL in the plasma and liver were higher in the OLI group than in the other groups. TG levels in the plasma and liver were highest in the OLI group and followed in order by the SAF and LIS groups. The concentration of plasma lipid peroxide was higher in the LIS group than in the other groups. Liver lipid peroxide content was extremely high in the LIS group, medium in the SAF group, and low in the OLI group. The activity of AST was highest in the OLI group and followed in order by the SAF and LIS groups. ALT activity was higher in the OLI group than in the other groups. A positive relationship between spontaneous liver tumorigenesis and the concentrations of T-CHOL, TG, and lipid peroxide or AST and ALT activities was hardly observed. These results suggested that spontaneous tumorigenesis in the liver of male C3H/He mice bred for 50 wk was suppressed by being supplied with OLI and LIS, compared with SAF, which had no direct relation to the concentrations of T-CHOL, TG, and lipid peroxide in the plasma and liver and the activities of plasma AST and ALT.