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E Tanaka

Publications and source records attributed to E Tanaka.

At least 55 records · Page 3Linked to original sources
PubMed2002

Viscoelastic properties and residual strain in a tensile creep test on bovine temporomandibular articular discs.

This study was designed to evaluate the creep characteristics and residual strain of bovine temporomandibular joint (TMJ) discs in tension. Twenty discs were divided into three specimens each: central, lateral and medial regions. Tension of 1.0 MPa was applied and sustained for 20 min to the specimens from 10 right-side discs, and tension of 1.5 MPa to specimens from 10 left-side discs. After the period of tension for creep, the specimens were removed from the tension devices and restoration observed for 20 min. Time-dependent creep curves showed a marked change in strain during the initial 5s. The essential time delay in strain ceased after 2 min, and strain reached an almost steady level after 3 min. At a tensile stress of 1.5 MPa, a strain of 14.5% on average was produced after 20 min creep in the central specimens; peripheral specimens showed strains of 12.4% on average. There were significant differences in strain between the central and peripheral specimens. The residual strain after 20 min restoration was 0.93% on average and there were no significant regional differences. This creep feature could be well represented by a generalized linear viscoelastic model. It was concluded that the regional differences in viscoelasticity might be caused by the complicated articulating functions of the TMJ, and that the residual strain caused by sustained stress could be an important factor in disc deformation.

Animals↗
PubMed2002

Biomechanical response of bovine temporomandibular joint disc to prolonged tensile stress.

This study was designed to evaluate the influence of prolonged tensile stress on the viscoelasticity of the temporomandibular joint (TMJ) disc. Twenty discs from 10, 3-year-old cattle were used. Tensile stress of 1.5 MPa was applied to specimens from the discs for 10, 20, 40 and 60 min. Following the prescribed period of tension for creep, the specimens were removed from the tension device and any recovery observed for 20 min. In all specimens, strain increased at the onset of stress application and reached almost steady conditions after 5 min. Although, the strain became slightly larger when the creep time was longer, no significant differences were found in the strains between any two tests with different periods of creep. The residual strain increased significantly with creep duration, and similarly the degree of recovery decreased significantly. In 10- and 20-min creep tests, the residual strains were 0.1 and 1.0%, the specimens in 40- and 60-min tests revealed irreversible changes in length. It was concluded that continuous loading for >40 min causes creep damage in bovine TMJ disc, and that prolonged sustained tension affects the recovery of joint homeostasis.

Animals↗
PubMed2002

The regional difference of viscoelastic property of bovine temporomandibular joint disc in compressive stress-relaxation.

An in vitro experimental technique was performed to measure the viscoelastic properties of the bovine disc. Thirteen TMJ discs from young cattle (3-year-old) were used. Each disc was divided into five specimens of anterior, central, posterior, lateral and medial regions, and they were used for compression tests. A series of stress-relaxation tests was conducted for each specimen from 5% strain up to 20% strain with 5% intervals. The stress-relaxation was monitored over a period of 5 min. Each region exhibited a different biomechanical behavior, which is presumably related to the organization and distribution of proteoglycans that indirectly modulate the stiffness of the collagen network. It is suggested that an improved understanding of the viscoelastic properties of the disc under function may guide consideration for design and selection of biomaterials for TMJ reconstruction.

Animals↗
PubMed2002

Direct and indirect actions of dopamine on the membrane potential in medium spiny neurons of the mouse neostriatum.

Many studies have shown dopamine (DA) to have a modulatory effect on neuronal excitability, which cannot be simply classified as excitatory or inhibitory in the neostriatum. To clarify whether the responses to DA (10-30 microM) are excitatory or inhibitory in the mouse medium spiny neurons, we examined the effects of DA agonists on the synchronous potential trajectory from the resting potential to the subthreshold potential. The DA-induced potential changes, which were estimated at the subthreshold potential (approximately -60 mV), were summarized as the combination of three kinds of responses: an initial hyperpolarization lasting approximately 1 min and a slow depolarization and/or hyperpolarization lasting more than 20 min. A D(1)-like receptor agonist, R(+)-6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide (SKF81297, 1 microM) mainly induced the initial hyperpolarization and slow depolarization. A D(2)-like receptor agonist, trans-(-)-4aR-4,4a,5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolo[3,4-g]quinoline hydrochloride (quinpirole, 1 microM), mainly induced the initial hyperpolarization and slow hyperpolarization. D(1)-like receptor antagonist R(+)-7-chloro-8-hydroxy-3-methyl1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390, 1 microM) depressed both the initial hyperpolarization and slow depolarization. D(2)-like receptor antagonist sulpiride (1 microM) depressed all the DA-induced responses except for the slow depolarization. TTX (0.5 microM) abolished all the DA-induced responses. Bicuculline (20 microM) and atropine (1 microM) abolished the DA-induced initial hyperpolarization and slow depolarization, respectively. Either DL-2-amino-5-phosphonopentanoic acid (AP5; 100 microM) or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 20 microM) blocked both the initial hyperpolarization and slow depolarization. The application of exogenous glutamate (Glu) mimicked the initial hyperpolarization and slow depolarization. These results suggest that the initial hyperpolarization is mainly due to GABA release via the cooperative action of D(1)- and D(2)-like receptors and Glu receptors in GABAergic interneurons, whereas the slow depolarization is mediated by acetylcholine (ACh) release via the cooperative action of mainly D(1)-like receptors and Glu receptors in cholinergic interneurons. The potential oscillation was generated at the subthreshold level in a Ba(2+)-, AP5-, CNQX-, bicuculline-, and atropine-containing medium. The oscillation depressed after the addition of TTX, Co(2+), or DA. In DA agonists, quinpirole rather than SKF81297 had a more depressive effect on the potential oscillation. These results indicate that the slow hyperpolarization is due to the suppression of noninactivating Na(+)-Ca(2+) conductances via mainly D(2)-like receptors in the medium spiny neurons. In conclusion, the DA actions on the medium spiny neurons show a transient inhibition by the activation of D(1)- and D(2)-like receptors in mainly GABAergic interneurons and a tonic excitation and/or inhibition by the activation of mainly D(1)-like receptors in cholinergic interneurons and by the activation of mainly D(2)-like receptors in the medium spiny neurons, respectively.

Anesthetics, Local↗
PubMed2002

Extrusion of intracellular calcium ion after in vitro ischemia in the rat hippocampal CA1 region.

Simultaneous recordings of intracellular Ca(2+) ([Ca(2+)](i)) signal and extracellular DC potential were obtained from the CA1 region in 1-[6-amino-2-(5-carboxy-2-oxazolyl)-5-benzofuranyloxy]-2-(2-amino-5-methylphenoxy)-ethane-N,N,N',N'-tetraacetic acid penta-acetoxymethyl ester (Fura-2/AM)-loaded rat hippocampal slices. Superfusion with oxygen- and glucose-deprived medium (in vitro ischemia) for 5-6 min produced a rapid rise of the [Ca(2+)](i) level in the stratum radiatum (rising phase of the [Ca(2+)](i) signal), which occurred simultaneously with a rapid negative DC potential (rapid negative potential). When oxygen and glucose were reintroduced, the increased [Ca(2+)](i) signal diminished rapidly (falling phase of the [Ca(2+)](i) signal) during the generation of a slow negative DC potential (slow negative potential), which occurred within 1 min from the onset of the reintroduction. Thereafter, the [Ca(2+)](i) signal partially and the slow negative potential completely returned to the preexposure level approximately 6 min after the reintroduction. The changes in [Ca(2+)](i) signal during and after in vitro ischemia were very similar to the changes in the membrane potential of glial cells. The rising and falling phases of [Ca(2+)](i) signal corresponded to the rapid depolarization and a depolarizing hump, respectively, in the repolarizing phase of glial cells. A prolonged application of in vitro ischemia or a reintroduction of either glucose or oxygen suppressed the falling phase after ischemic exposure. The application of ouabain (30 microM) generated both a rapid negative potential and a rapid elevation of [Ca(2+)](i), but no slow negative potential or rapid reduction in [Ca(2+)](i) were observed. When oxygen and glucose were reintroduced to slices in the Na(+)-free or ouabain- or Ni(2+)-containing medium, the falling phase was suppressed. The falling phase was significantly accelerated in Ca(2+)- and Mg(2+)-free with EGTA-containing medium. In contrast, the falling phase was significantly slower in the Ca(2+)-free with high Mg(2+)- and EGTA-containing medium. The falling phase of the [Ca(2+)](i) signal after ischemic exposure is thus considered to be primarily dependent on the reactivation of Na(+), K(+)-ATPases, while the extrusion of cytosolic Ca(2+) via the forward-mode operation of Na(+)/Ca(2+) exchangers in glial cells is thought to be directly involved in the rapid reduction of [Ca(2+)](i) after ischemic exposure.

Animals↗
PubMed2002

Dynamic properties of bovine temporomandibular joint disks change with age.

The temporomandibular joint disk exhibits morphological and biochemical age-related changes. However, the possible age-related changes of the dynamic viscoelasticity in the disk are unclear. We tested the hypothesis that the dynamic viscoelastic properties of the disk change with age. Thirty-six disks from young-adult, adult, and mature-adult cattle were used for dynamic tensile tests. In all disks, the magnitudes of the complex modulus, the storage modulus, and the loss modulus increased as the frequency increased. The mature-adult disks had higher values of these moduli than did the younger disks. The loss tangent ranged from 0.1 to 0.3, which means that the disk has relatively large elasticity and relatively small viscosity. It was concluded that both the elasticity and viscosity of the disk increase with age. This may reflect age-related changes in biochemical composition.

Aging↗
PubMed2001

Association between SEN virus infection and hepatitis C in Japan.

There is a strong association between 2 SEN virus (SENV) variants (SENV-D and SENV-H) and transfusion-associated non-A-E hepatitis. In total, 200 subjects from a Japanese region where hepatitis C virus (HCV) is highly endemic and 194 persons from a contiguous area where HCV is not endemic were tested for SENV-D and SENV-H DNA by polymerase chain reaction. SENV DNA was detected equally in subjects from each area (56% prevalence in the area of high endemicity vs. 61% in the nonendemic area). Age-specific prevalence of SENV was similar to that of TT virus, with equal distribution at all ages in both areas; HCV was predominant in the elderly population. Alanine aminotransferase levels were significantly associated with HCV viremia but not with SENV viremia. SENV is a common infection that appears to have transmission routes and age-related prevalence that are distinct from those of HCV. No evidence was found that SENV caused hepatitis or worsened the course of hepatitis C.

Adolescent↗
PubMed2001

Phase III trial of high- vs. low-dose-rate interstitial radiotherapy for early mobile tongue cancer.

PURPOSE: Early mobile tongue cancer can be controlled with interstitial radiotherapy (ISRT). We carried out a Phase III trial to compare the treatment results of low-dose-rate (LDR) ISRT and high-dose-rate (HDR) ISRT for early mobile tongue cancer. METHODS AND MATERIALS: From April 1992 through October 1996, 59 patients with cancer of the early mobile tongue were registered in this Phase III study. Eight patients were excluded from the evaluation because of violations of the requirements for this study. Of 51 eligible patients, 26 patients were treated with LDR-ISRT (70 Gy/4-9 days) and 25 patients with HDR-ISRT (60 Gy/10 fractions/1 week). For the hyperfractionated HDR-ISRT, the time interval between 2 fractions was more than 6 h. RESULTS: Five-year local control rates of the LDR and HDR groups were 84% and 87% respectively. Nodal metastasis occurred in 6 patients in each group. Five-year nodal control rates of the LDR and HDR groups were 77% and 76%, respectively. CONCLUSION: Hyperfractionated HDR-ISRT for early mobile tongue cancer has the same local control compared with continuous LDR-ISRT. Hyperfractionated HDR-ISRT is an alternative treatment for continuous LDR-ISRT.

Adult↗
PubMed2001

Determination of plasma bromvalerylurea and its main metabolite by a simple high-performance liquid chromatographic method and quantitation of bromide by energy dispersive X-ray spectrometry in carbon tetrachloride-intoxicated rats.

In the present study, small volumes of plasma were used for the measurement of bromvalerylurea (BVU), its metabolite, 3-methylbutyrylurea (MVU), and bromide in carbon tetrachloride (CCl4)-treated rats by HPLC-UV and energy dispersive X-ray spectrometry. A liquid-liquid extraction system was also investigated. BVU and MVU were extracted from 100 microl plasma samples in a single-step involving deproteination with 1 M hydrochloric acid using ethenzamide as internal standard. Samples were separated by HPLC in an acetonitrile-8 mM potassium dihydrogenphosphate buffer (35:65, v/v) mobile phase at a flow-rate of 0.4 ml/min on a 15 cm octadecylsilyl column at room temperature. Analytes were detected at a wavelength of 210 nm. The limits of quantitation for BVU, MVU and bromide are 0.1, 0.1 and 50 microg/ml, respectively. The intra-day accuracies over the range of concentrations were 95.8 to 121.1%, 97.2 to 119.7% and 96.2 to 105.8% for BVU, MVU and bromide, respectively. The inter-day accuracies were 97.7 to 115.1%, 98.3 to 111.6% and 98.3 to 102.9% for BVU, MVU and bromide, respectively. The absolute recoveries using tert.-butyl methyl ether are 96-98% for BVU and 95-98% for MVU. The decline in the plasma concentrations of BVU in olive oil-treated rats fitted a one-compartment model and the plasma MVU level reached a peak at around 1.5-2 h and then decreased gradually. The elimination of BVU in CCl4 (1 ml/kg)-treated rats was delayed and MVU production was less than that in the olive oil-treated group. However, there was no difference in the plasma levels of bromide between CCl4-treated rats and control rats. rights reserved.

Animals↗
PubMed2001

Influence of age on the results of brachytherapy for early tongue cancer.

PURPOSE: To determine the influence of elder age on the results of brachytherapy for early (T1-2 N0 M0) oral tongue cancer and examine the compatibility of low-dose rate (LDR) with high-dose rate (HDR) brachytherapy. METHODS AND MATERIALS: We analyzed 591 patients treated at Osaka University Hospital between 1967 and 1999. We compared the results of radiotherapy for 156 elderly patients (137 LDR and 19 HDR) 65 years of age or older and 435 patients (383 LDR and 52 HDR) less than 65 years of age. RESULTS: HDR brachytherapy showed the same local control rate as LDR brachytherapy (81% at 3 years). Elderly patients showed a poorer local control rate (75% at 3 years) than the younger group (83% at 3 years)(p = 0.002). Multivariate analysis identified age as the only prognostic factor for local control (p = 0.002). CONCLUSIONS: HDR brachytherapy achieved the same result as LDR brachytherapy. However, the elderly patient showed a higher rate of local recurrence after brachytherapy.

Adult↗
PubMed2001

Role of endogenous nitric oxide generation in the regulation of vascular tone and reactivity in small vessels as investigated in transgenic mice using synchrotron radiation microangiography.

Nitric oxide (NO) produced by endothelial NO synthase (eNOS) plays a central role in regulation of vascular tone and reactivity. The purpose of this study is to clarify the basal tone and microvascular reactivity in eNOS-overexpressing transgenic (Tg) mice in vivo with a microangiography system using monochromatic synchrotron radiation (SR). The mouse femoral artery was cannulated, nonionic contrast media was injected, and microangiography was performed in hindlimbs of mice. Serial images of the small blood vessels (diameter <200 microm) were recorded by the SR microangiography system. At basal conditions, the diameter of tibial arteries in eNOS-Tg mice was larger than that of wild-type mice (179 +/- 8 versus 132 +/- 8 microm; P < 0.01). l-NAME treatment decreased the vessel diameter and canceled the difference in vessel diameters between two genotypes. Acetylcholine- and sodium nitroprusside-induced relaxations of small vessels were significantly reduced in Tg mice compared with wild-type mice (35.0 +/- 9.4 versus 61.6 +/- 6.7%, 85.0 +/- 10.2 versus 97.3 +/- 6.7% of the maximum relaxation, respectively). Our data provide the evidence that overproduced NO from endothelium reduces vascular tone and plays a pivotal role in regulation of vascular tone in small vessels. Furthermore, the reduced NO-mediated relaxation in small vessels of eNOS-Tg mice is demonstrated for the first time in vivo. SR microangiography allows us to evaluate the reactivity in small-sized vessels and appears to be a powerful tool for assessing the microvascular circulation in vivo.

Angiography↗
PubMed2001

Relationship between hepatitis C virus infection and schistosomal liver disease: not simply an additive effect.

BACKGROUND: To study the association, clinical significance, and impact of hepatitis C virus (HCV) co-infection in patients with schistosomal liver disease (SLD). METHODS: A total of 240 patients with chronic liver diseases encountered consecutively were enrolled in the study. Fifty volunteer blood donors were enrolled as controls. HCV antibody determination (enzyme-linked immunosorbent assay), qualitative and quantitative HCV RNA assay (reverse transcriptase polymerase chain reaction), and HCV genotyping (line probe assay) were performed. RESULTS: Twenty-eight patients had SLD alone, 60 had both SLD and chronic hepatitis C (CH-C), 120 had CH-C alone, and 32 had other liver diseases. The positivity rates for HCV antibody (76% vs 20%; P < 0.001) and HCV RNA (59% vs 10%; P < 0.001) were significantly higher in the patients with SLD (n = 88) than in the volunteer blood donors (n = 50). Complications of liver cirrhosis were more common in patients with concomitant SLD and CH-C than in those with either SLD or CH-C alone. The mean levels of alanine aminotransferase (77 +/- 42 vs 93 +/- 55 IU/l; P = 0.049) and HCV RNA concentrations (3.5 +/- 1.0 vs 4.2 +/- 1.0 log copy/ml; P < 0.001) were significantly lower in patients with concomitant SLD and CH-C than in those with CH-C alone. HCV genotype 4 predominated in both these groups (93% and 98%). CONCLUSIONS: SLD in Egypt is significantly associated with HCV infection, with the predominance of genotype 4. Concurrent HCV infection and SLD result in much more severe liver disease than that seen with either disease alone. However, the activity of HCV infection seems to be partially suppressed in patients with SLD.

Adult↗
PubMed2001

Seroepidemiological study of hepatitis E virus infection in Japan using a newly developed antibody assay.

PURPOSE: A seroepidemiological study of hepatitis E virus (HEV) infection was conducted in Japan, where HEV infection is not considered endemic. METHODS: IgG and IgM class antibodies to HEV were measured with a newly developed enzyme-linked immunosorbent assay in which recombinant virus-like particles were used as an antigen. A total of 1253 individuals (401 males and 852 females; age range, 6-89 years) were enrolled from two different areas: area 1 (n = 478), in which hepatitis C was endemic; and area 2 (n = 775), in which it was not endemic. RESULTS: The HEV antibody (IgG class) positive rate was 6.7% in area 1 and 4.6% in area 2. Similarly, the HAV antibody (IgG class) positive rates were 65.3% and 72.3%. The age- and sex-specific prevalence of both HAV and HEV antibodies was quite similar in the two areas, and the HAV antibody positive rate clearly increased with age in both males and females. On the other hand, the HEV antibody positive rate showed a slight tendency to increase with age in males, but not in females. None of the 32 individuals with the HEV antibody who were interviewed had a history of visiting countries in which hepatitis E was endemic. In both areas, the mean age, percentage of males, and HAV antibody positive rate were significantly higher in the group of individuals with the HEV antibody than in the group of those without it, according to conventional statistical analyses. Of the three factors age, male sex, presence of HAV antibody, and the area factor, only male sex was statistically significant (P < 0.001) on multivariate logistic regression analysis. Two (0.2%) of the total of 1253 individuals were positive for the IgM class antibody to HEV. CONCLUSIONS: Our results suggest the possibility that HEV infection is circulating in Japan at a low level. HEV infection was associated with male sex, but not with HAV infection.

Adolescent↗
PubMed2001

A new procedure of percutaneous microwave coagulation therapy under artificial hydrothorax for patients with liver tumors in the hepatic dome.

Percutaneous microwave coagulation therapy (PMCT) has been widely used as an effective minimal invasive therapy for small liver tumors. The occurrence of a sonographic masked space due to the presence of the lung, however, has become a major obstacle to visualizing the whole tumor in the hepatic dome. To facilitate the use of PMCT for liver tumors in the hepatic dome, we developed PMCT in combination with the artificial hydrothorax method (percutaneous transdiaphragmatic MCT: PTD-MCT). Our new approach for PMCT to the hepatic tumors located in Couinaud's segments VIII or VII just under the diaphragm resulted in a successful treatment. The separation of the lung from the diaphragm by the infusion of saline into the pleural cavity enabled us not only to visualize the whole tumor in the hepatic dome to accurately target the tumor, but also helped us to avoid injuring the lung. PTD-MCT is therefore strongly recommended for the treatment of liver tumors in the hepatic dome.

Aged↗
PubMed2001

Biomechanical behaviour of bovine temporomandibular articular discs with age.

The purpose was to evaluate age-associated changes in the creep and restoration properties of bovine temporomandibular joint (TMJ) discs under and after sustained tensile stress. Forty discs were obtained from 7- and 10-year-old cattle, referred to as the adult and mature adult groups, respectively. Tension of 1.0 MPa was applied and sustained for 20 min to specimens from ten right discs and of 1.5 MPa to specimens from ten left discs. After the period of tension for the study of creep, the specimens were removed from the tension devices and their restoration observed for 20 min. For comparative purposes the relevant results for a young adult group were recruited from data on 3-year-old bovine TMJ discs reported in a previous study on viscoelastic properties. In all the specimens the time-dependent creep curves showed a marked change in strain during the initial 5 s, but the elastic moduli at the onset of stress were significantly larger in the mature adult group than in the other groups. After 20-min creep, the strains were decreased in relation to the age of the specimen and were significantly smaller in the mature adult than in the young adult. With regard to regional differences, the medial specimens exhibited significantly smaller strains than the central ones in all three age groups. Furthermore, the residual strains after 20-min restoration also decreased slightly with age. It is concluded that the bovine TMJ disc becomes stiff and acquires the capacity to recover from continuous deformation during growth and maturation. These findings suggest that the TMJ disc can modify its viscoelasticity in order to withstand extrinsic functional stresses.

Aging↗
PubMed2001

Proposal of a new grading system for evaluation of tongue hemiatrophy as a late effect of brachytherapy for oral tongue cancer.

PURPOSE: To evaluate tongue hemiatrophy as a late effect of brachytherapy, a new grading system was designed and applied to patients who had received low dose rate (LDR) or high dose rate (HDR) brachytherapy for early tongue cancer. METHODS AND MATERIALS: Between December 1998 and April 1999, 49 patients who had received brachytherapy for early tongue cancer (T1/T2=22:27) at Osaka University Hospital were investigated. All patients had undergone either LDR or HDR brachytherapy with Ir-192 (LDR/HDR=30:19) between 1980 and 1998. Atrophic changes in their tongue were classified into four categories (G0-G3): G3, not able to protrude the tongue beyond incisors; G2, hemiatrophy is seen on the irradiated side in the resting position of the tongue; G1, deviation of the tip of the tongue to the irradiated side is seen when protruded; and G0, none of these signs. The relationship between tongue hemiatrophy and tumor factors, treatment factors, and patients' functional impairment was then investigated. The median time from treatment to assessment was 75 months (range 8-219 months). Volume index was defined as the number of needles that were implanted vertically into the tongue. RESULTS: Fourteen patients were classified as G0, 29 as G1, five as G2, and one as G3. None of the G0 patients showed any speech or swallowing dysfunction, pain or contracted feeling, or general dissatisfaction with post-treatment tongue status. There was a tendency for such problems to increase with the tongue hemiatrophy grade. The frequency of T2 and non-superficial type tumors also tended to increase with the tongue hemiatrophy grade. The volume index of the G2-3 hemiatrophy group was significantly larger than that of the G0-1 group (P=0.041). CONCLUSION: This new grading system makes evaluation of atrophic changes in the tongue after brachytherapy easy and effective.

Adult↗
PubMed2001

Hepatocarcinogenesis inhibition by caffeine in ACI rats treated with 2-acetylaminofluorene.

The inhibitory effects of caffeine have been demonstrated on the development of various organs in animals. The purpose of the present study was to examine the inhibitory effect of caffeine on hepatocarcinogenesis and to determine the responsive dose of caffeine on hepatocarcinogenesis in young male ACI rats. Animals given a diet containing 2-acetylaminofluorene (2-AAF) for 12 weeks and then a basal diet and tap water containing caffeine for 18 weeks showed statistically significant decreases in the incidence, multiplicity (the number of hepatic tumors per rat) and histological grade compared with rats fed a diet containing carcinogen for 12 weeks followed by tap water alone. Dose-dependent inhibition of hepatocarcinogenesis by caffeine was also seen. The inhibitory effect of caffeine on hepatocarcinogenesis in rats was found when caffeine was administered during the initiation phase.

2-Acetylaminofluorene↗