Carotid Artery Angioplasty and Stenting as a First-choice Revascularization Therapy for Cervical Carotid Artery Stenosis

SUMMARY

We examined the patients with cervical carotid artery stenosis (> 70%) treated by carotid artery angioplasty and stenting (CAS) as a firstchoice direct revascularization therapy. The patients consisted of 45 men and seven women; their mean age was 70.4 years (range, 54-84 yr), with 60 cervical carotid stenosis (39 symptomatic and 21 asymptomatic). Sixty procedures resulted in successful stent deployment in 55 cases, percutaneous transluminal angioplasty (PTA) only without stenting in three, and failed angioplasty due to inaccessibility in two. Morbidity was seen in three cases associated with thromboembolic complication. Instent restenosis was observed in one case, which was successfully treated with subsequent PTA. CAS seems reasonable treatment for cervical carotid artery stenosis, although further accumulation of the cases will be needed to evaluate the efficacy between CAS and carotid endarterectomy.

Spontaneous improvement of persistent ulceration after carotid artery stenting

BACKGROUND AND PURPOSE

Because carotid plaque ulceration is associated with an increased risk of cerebral embolism, residual carotid plaque ulceration directly around a stent (persistent ulceration) after carotid angioplasty and stent placement (CAS) could still be a risk factor for a stroke. The purpose of this study is to understand the morphologic and clinical prognosis of persistent ulceration.

PATIENTS AND TECHNIQUES

CAS was attempted on 91 consecutive stenotic lesions (80 patients). Of these, 54 lesions (48 patients) had ulceration before CAS. Angiograms were evaluated immediately after the procedure. Persistent ulceration was found in 34 lesions (30 patients). The mean depth and length of persistent ulcers were 2.1 mm (range, 1-4.7 mm) and 8.9 mm (range, 1.5-22 mm), respectively. All patients with persistent ulceration were followed with antiplatelet therapy.

RESULTS

No ischemic event due to the lesions occurred during the mean follow-up period of 25.5 months (range, 3-48 months). Angiography on 25 lesions (21 patients) at a mean of 5.8 months (range, 1-21 months) after CAS showed that persistent ulceration disappeared in 12 lesions (48%), improved in 11 lesions (44%), and remained unchanged in 2 lesions (8%). Nine lesions (36%) showed restenosis, which were < or =30% and did not require any additional intervention. New ischemic lesions were not detected in any of the 14 patients (17 lesions) who underwent follow-up MR imaging at a mean of 9 months (range, 1-32 months) after CAS.

CONCLUSION

We conclude that persistent ulceration after CAS improves spontaneously and is not a risk factor for cerebral embolism.

A new three-dimensional automatic bodymarker system for transvaginal ultrasonography

OBJECTIVE

To evaluate the accuracy and usefulness of a newly developed three-dimensional automatic bodymarker system for transvaginal ultrasonography.

METHODS

A bodymarker system which utilizes an electromagnetic field to specify the probe position was developed. Software was written which enabled the positional information of the probe and the ultrasound image to be simultaneously displayed on a personal computer. The bodymarker was displayed as a three-dimensional graphic model. The differences between the estimated and the actual position--i.e. the error--for both position (x, y and z) and angles (azimuth, elevation and roll) of the probe were measured. The movement of the probe was then evaluated in healthy female volunteers and the comparative time required for ultrasound examination was determined.

RESULTS

Both the position and the angles of the probe were accurately shown in the computer display. The errors were 1.0 mm and 0.7 degrees (median) for position and angle, respectively. The system was also shown to work well in healthy female volunteers. Calibration of the new system required only 5.0 seconds, compared with an average of 7.6 seconds for the conventional bodymarker.

CONCLUSION

The newly developed three-dimensional automatic transvaginal bodymarker system provides an accurate indication of probe position and its tilting angle. It works well in healthy female volunteers and speeds up the examination time. It may be clinically useful for transvaginal ultrasound examination.

Midkine promoter-driven suicide gene expression and -mediated adenovirus replication produced cytotoxic effects to immortalised and tumour cells

We examined possible application of a regulatory region of midkine (MK) gene, which is frequently upregulated in a number of human tumours but not in normal cells, to cancer gene therapy. We examined transcriptional activity of the MK genomic fragments in paired cell lines, immortalized cells and their parental normal fibroblasts, and found that the MK fragments activated a fused reporter or a suicide gene preferentially in the immortalized cells. Recombinant adenoviruses (Ad), in which the MK fragment was inserted upstream to the E1A gene (AdMK), replicated preferentially in the immortalized cells and were cytotoxie to them. Human hepatocellular carcinoma cells were significantly susceptible to AdMK compared with human normal fibroblasts in vitro and the replication of AdMK was less than that of wild-type Ad in the infected fibroblasts. Hepatocellular carcinoma cells infected with AdMK did not form tumours in immunocompromised mice and intratumoural injection of AdMK into the hepatocellular carcinoma developed in mice retarded the subsequent tumour growth. Expression of E1A and necrosis of tumours were detected in AdMK-injected but not control Ad-injected cases. The MK promoter-driven suicide gene therapy and -mediated replicative Ad can thereby produce cytotoxic effects to immortalized and tumour cells with minimal damage to normal cells.

Human amniotic epithelial cells are morphologically homogeneous: enzymehistochemical, tracer, and freeze-substitution fixation study

We examined the fine subcellular morphology of human amniotic epithelial cells and attempted to answer the question as to whether amniotic epithelial cells consist of heterogeneous or homogeneous cells, which has long been controversial. Study subjects were fetal membranes from pregnant women (n=18) who abdominally gave birth to healthy infants at term (37.9+/-0.7 weeks of gestation, mean+/-sd). The methods employed were transmission electron microscopy, enzymehistochemistry, tracer permeability analysis, and freeze-substitution fixation. The labelings for acid phosphatase, cytochrome c oxidase, and CA++ATPase were seen in the lysosomes, mitochondria, and lateral plasma membranes, respectively. The staining distribution pattern of these three enzymes and the morphology of the organelle highlighted by these enzymehistochemistry did not differ among cells. Freeze-substitution fixation revealed that intercellular spaces in the amniotic epithelial cells were narrower than previously thought, but the tracers (horse radish peroxidase and lanthanum nitrate) fully entered these spaces. There were no variations in the tracer permeability among cells. All cells from freeze-substitution fixation exhibited the same morphological features. From these morphological viewpoints, we conclude that human term amniotic epithelial cells consist of a homogeneous cell population.

Pathological changes of the myonuclear fibrous lamina and internal nuclear membrane in two cases of autosomal dominant limb-girdle muscular dystrophy with atrioventricular conduction disturbance (LGMD1B)

Mutations in the lamin A/C gene have been reported in a variety of disorders including autosomal dominant Emery-Dreifuss muscular dystrophy and autosomal dominant limb girdle muscular dystrophy with cardiac conduction block or limb girdle muscular dystrophy type 1B (LGMD1B). However, how these mutations are involved in developing these diseases is not known. We examined morphological changes of the skeletal muscle in two cases of LGMD1B in a family, directing our attention to the nuclear envelope and its underlying structures where lamin A/C is located. Although conventional fluorescence microscope revealed no discernible abnormality in the distribution of emerin and lamin A/C, a serial multi-layer scanning with confocal laser scanning microscope showed an attenuated and uneven distribution of lamin A/C. Furthermore, under an electron microscope, the nuclear fibrous lamina and inner nuclear membrane were relatively indistinct compared to controls. These changes in the myonuclei may be related to pathomechanisms of the present cases.

Demonstration of glucose-6-phosphate dehydrogenase in rat Kupffer cells by a newly-developed ultrastructural enzyme-cytochemistry

Although various tissue macrophages possess high glucose-6-phosphate dehydrogenase (G6PD) activity, which is reported to be closely associated with their phagocytotic/bactericidal function, the fine subcellular localization of this enzyme in liver resident macrophages (Kupffer cells) has not been determined. We have investigated the subcellular localization of G6PD in Kupffer cells in rat liver, using a newly developed enzyme-cytochemical (copper-ferrocyanide) method. Electron-dense precipitates indicating G6PD activity were clearly visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of Kupffer cells. Cytochemical controls ensured specific detection of the enzymatic activity. Rat Kupffer cells abundantly possessed enzyme-cytochemically detectable G6PD activity. Kupffer cell G6PD may play a role in liver defense by delivering NADPH to NADPH-dependent enzymes. G6PD enzyme-cytochemistry may be a useful tool for the study of Kupffer cell functions.

A promoter region of the midkine gene that is frequently expressed in human hepatocellular carcinoma can activate a suicide gene as effectively as the alpha-fetoprotein promoter

We examined the expression of the midkine (MK) and alpha-fetoprotein (AFP) genes in 15 paired human specimens obtained from hepatocellular carcinoma (HCC) and the corresponding noncancerous regions of the same patients. A total of 14 HCC but none of the noncancerous specimens were positive for the MK mRNA. In contrast, three HCC specimens and one corresponding noncancerous sample out of the three AFP-positive HCC cases expressed the AFP gene. A 2.3-kb genomic fragment in the regulatory region of the MK gene could activate a fused reporter gene in both AFP-producing and -nonproducing HCC lines, and the MK fragment-mediated transcriptional activity was comparable to the AFP enhancer-linked AFP promoter in AFP-producing cell lines. The AFP-producing but not AFP-nonproducing HCC cell lines that were transfected with the MK promoter-linked herpes simplex virus-thymidine kinase (HSV-TK) gene became susceptible to a prodrug ganciclovir to a similar degree of the HCC transfected with the enhancer-linked AFP promoter-fused HSV-TK gene. These data suggest that the MK promoter can activate a therapeutic gene preferentially in HCC and is as useful as the AFP promoter in clinical settings.

Diagnosis of acute brain-stem infarcts using diffusion-weighed MRI

There are many reports on acute cerebral infarcts diagnosed by diffusion-weighted MRI (DWI), but few describe brain-stem infarcts diagnosed by this method. Using the apparent diffusion coefficient (ADC), we studied 18 consecutive patients with brain-stem infarcts who underwent DWI during the acute phase. We calculated and compared the ADC ratio (lesion ADC/contralateral ADC) in 10 patients with brain-stem and 23 with supratentorial cortical infarcts examined within 24 h of the onset of stroke. Ischaemic brain-stem lesions were detected in all 15 patients who underwent DWI more than 3 h after the onset, but not in two who had DWI within 3 h of the onset; their ADC ratio was more than 0.95. ADC ratios in patients with brain-stem infarcts decreased as the interval between onset and DWI increased; the decrease was slower than in patients with supratentorial cortical infarcts.

Glucose-6-phosphate dehydrogenase in rat lung alveolar epithelial cells. An ultrastructural enzyme-cytochemical study

Glucose-6-phosphate dehydrogenase (G6PD) is the key enzyme of the pentose phosphate pathway in carbohydrate metabolism, and it plays an important role in cell proliferation and antioxidant regulation within cells in various organs. Although marked cell proliferation and oxidant/antioxidant metabolism occur in lung alveolar epithelial cells, definite data has been lacking as to whether cytochemically detectable G6PD is present in alveolar epithelial cells. The distribution pattern of G6PD within these cells, if it is present, is also unknown. The purpose of the present study was to investigate the subcellular localization of G6PD in alveolar cells in the rat lung using a newly-developed enzyme-cytochemistry (copper-ferrocyanide) method. Type I cells and stromal endothelia and fibroblasts showed no activities. Electron-dense precipitates indicating G6PD activity were clearly visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of type II alveolar epithelial cells. The cytochemical controls ensured specific detection of enzyme activity. This enzyme may play a role in airway defense by delivering substances for cell proliferation and antioxidant forces, thus maintaining the airway architecture.

Simultaneous demonstration of acid phosphatase and glucose-6-phosphate dehydrogenase in mouse hepatocytes. A novel electron-microscopic dual staining enzyme-cytochemistry

Acid phosphatase (ACPase) and glucose-6-phosphate dehydrogenase (G6PD) play important roles in cell biology/disease pathophysiology in various organs including the liver. The purpose of the present report is to introduce a new enzymecytochemical method to simultaneously demonstrate the subcellular localization of ACPase and G6PD within the same hepatocyte in the mouse liver. The ultrastructural localization of ACPase and G6PD were demonstrated, with concomitant use of the cerium method and the copper-ferrocyanide method, respectively. ACPase labelings were localized in the lysosomes, and G6PD labelings were visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of the hepatocyte. This novel double staining procedure may be a useful histochemical tool for the study of liver functions in both physiological and pathological conditions.

Hofbauer cell activation and its increased glucose-6-phosphate dehydrogenase activity in second trimester-spontaneous abortion: an ultrastructural dual staining enzyme-cytochemical study

PROBLEM

While activated/phagocytosing phagocytes infiltrating to the chorioamnion are considered to be one of the causal agents of preterm labor onset, whether placental villous macrophages (Hofbauer cells) are activated/phagocytosing in this condition is not known.

METHOD OF STUDY

We concomitantly localized two important phagocytosis-related enzymes, acid phosphatase (ACP) and glucose-6-phosphate dehydrogenase (G6PD), in Hofbauer cells in second trimester placental villi, and compared them with those from infection-related second trimester-spontaneous abortion (miscarriage) placentas.

RESULTS

There were two types of Hofbauer cells. The first cells exhibited ACP stainings confined to the lysosomes, suggesting that they are dormant/non-activated cells. Approximately two-thirds of these cells showed weak G6PD labeling on the cytosolic side of endoplasmic reticula, and G6PD labeling was hardly recognizable in the remaining one-third. The second cells, possessing large phagosomes, showed marked ACP labeling in the phagosomes, suggesting that they are activated/phagocytosing cells. All these cells exhibited G6PD labeling, and in 'bursting cells' (possibly hyperactivated cells) G6PD deposits were marked. The percentage of activated cells in miscarriage placentas was significantly higher (44.8 +/- 6.0%) than that in gestational age-matched controls (17.4 +/- 5.3%).

CONCLUSIONS

These observations indicated that (1) G6PD activity increased in activated/phagocytosing Hofbauer cells, and (2) the percentage of phagocytosing cells increased in infection-related miscarriage placentas. Hofbauer activation and G6PD may play an role in the pathogenesis/pathophysiology of preterm labor onset.

Evaluation of Bifidobacterium breve strain Yakult-fermented soymilk as a probiotic food

We evaluated the effects of Bifidobacterium breve-fermented soymilk on probiotic function. An administered strain of B. breve strain Yakult was capable of growing in soymilk with no additives as high as 10(9) CFU/ml. During storage of the fermented soymilk at 10 degrees C for 20 days, viable counts of the strain did not change. The growth inhibition of the strain in a bile-containing medium was lessened by the addition of soy protein. In human feeding experiments, the administered B. breve was recovered at a level of over 10(9) CFU/g faeces, accompanied by an increase in the total number of bifidobacteria. These results indicate that fermented soymilk with B. breve strain Yakult could be a novel type of probiotic food.

Umbilical cord pseudocyst in a fetus with trisomy 18

An umbilical cord pseudocyst was detected in the 28th week of gestation in a fetus complicated with growth restriction and polyhydramnios. The combination of cord pseudocysts, growth restriction, and polyhydramnios prompted us to perform a detailed ultrasonographic examination (gray scale and three-dimensional), which revealed the presence of micrognathia, overlapping fingers, and congenital heart defects, features characteristic of trisomy 18. Karyotyping confirmed a diagnosis of trisomy 18. After spontaneous labor onset, the infant was delivered at 31 weeks of gestation, and died soon after delivery. An umbilical cord pseudocyst is a good marker for the prenatal detection of trisomy 18.

The multiple endocrine neoplasia type 1 gene product, menin, inhibits the human prolactin promoter activity

Menin is a protein encoded by the gene mutated in multiple endocrine neoplasia type 1 (MEN1) characterized by multiple endocrine tumors of the parathyroid glands, pancreatic islets and the anterior pituitary, especially prolactinoma. In this study, we examined the effects of menin on human prolactin (hPRL) expression. In rat pituitary GH3 cells stably expressing menin, both PRL gene expression/secretion and thymidine incorporation into DNA were inhibited as compared with mock-transfected cells. The transcriptional activity of PRL promoter in GH3 cells co-transfected with menin was significantly decreased. A deletion mutation (569 delC), which we identified in a Japanese MEN1 family, was introduced into menin. When GH3 cells were transfected with a mutant menin expression vector, inhibition of hPRL promoter activity was partially reversed. These observations suggest that menin inhibits hPRL promoter activity and cell proliferation, raising the possibility that menin might play an important role in the tumorigenesis of prolactinoma.

Clinical implications of cardiac (123)I-meta-iodobenzylguanidine scintigraphy and cardiac natriuretic peptides in patients with heart disease

The purpose of this study was to evaluate whether or not cardiac sympathetic nerve activity, using (123)I-meta-iodobenzylguanidine ((123)I-MIBG) imaging, and cardiac natriuretic peptides (atrial and brain, ANP and BNP) were independent predictors of cardiac events, and, if so, which was the stronger predictor. Planar (123)I-MIBG images were obtained from 62 patients with heart disease. Plasma ANP and BNP levels, left ventricular ejection fraction (LVEF) by echocardiography, serum total cholesterol and triglyceride were measured. (123)I-MIBG was assessed as the heart-to-mediastinum (H/M) ratio of the delayed image and the washout rate (WoR) from the early to the delayed image. Patients were followed up for an average of 16.2 months, and 12 of 62 patients had cardiac events. Patients with events had significantly lower LVEF and H/M ratio compared with those without events. They had significantly higher WoR, ANP and BNP. By multivariate Cox proportional hazard analysis, (123)I-MIBG (H/M or WoR), ANP and BNP were independent predictors for cardiac events. Event-free survival using a Kaplan-Meier model, with a threshold value of 2.0 for H/M and 45% for WoR, showed that patients with H/M<2.0 and/or WoR>45% had a significantly poorer prognosis. These results suggest that (123)I-MIBG imaging and cardiac natriuretic peptides are useful tools for the evaluation of patients with heart disease, and that cardiac sympathetic nerve activity is a stronger predictor of cardiac events.

Prophylactic cranial irradiation of acute lymphoblastic leukemia in childhood: outcomes of late effects on pituitary function and growth in long-term survivors

It is well known that prophylactic cranial irradiation is highly effective in preventing central nervous system (CNS) relapse of acute lymphoblastic leukemia (ALL). Nevertheless, there have been very few reports on the late effects, especially pituitary function and growth, in long-term survivors who were treated with 18 Gy cranial irradiation in childhood. The subjects consisted of 35 children with ALL who were treated with prophylactic 18 Gy cranial irradiation at Kanagawa Children's Medical Center between October 1981 and February 1995. All patients received cranial irradiation after first attaining complete remission with induction chemotherapy, according to the treatment protocols prescribed by the Tokyo Children's Leukemia Study Group (TCLSG) and Tokyo Children's Cancer Study Group (TCCSG). Their ages at the time of cranial irradiation ranged from 2.2-15.0 years (mean 6.8). We evaluated their pituitary functions by measuring their pituitary hormone values 0.7-11.3 years (mean 6.0) after cranial irradiation and their growth by analyzing their height standard deviation score (SDS) at diagnosis of ALL and their final height SDS at the mean follow-up period of 8.2 years after cranial irradiation. Height SDS is defined as the difference between the patient's height and the mean height of their age and sex, divided by the standard deviation of their age and sex. Eight of 35 patients had ALL relapse, involving the bone marrow in seven patients and the CNS in only one. Six of the eight patients with relapse died 1.5-6.6 years after cranial irradiation and the other two patients were salvaged by further intensive therapies. The remaining 27 relapse-free patients have survived for 1.4-15.8 years (mean 10.1) after cranial irradiation. Twenty-six of the 29 survivors are long-term survivors of more than 5 years. Although there was one patient with an abnormal result in each value of growth hormone (GH), adrenocorticotropic hormone (ACTH), and prolactin (PRL), and two patients with abnormal results in thyroid-stimulating hormone (TSH) values, none of the patients had clinical symptoms of pituitary hormone abnormality and none required hormone supplements. The final height SDS decreased significantly compared with the height SDS at diagnosis of ALL in the long-term survivors (P = 0.001) and the height SDS of the patients who had received cranial irradiation at a young age tended to decrease gradually (P = 0.019). However, no patient showed severe growth failure. It is considered that prophylactic 18 Gy cranial irradiation plus chemotherapy for ALL in childhood can effectively prevent CNS relapse and is unlikely to produce clinically significant late effects, although it may cause slight pituitary hormone abnormality.

Effect of labor on maternal dehydration, starvation, coagulation, and fibrinolysis

BACKGROUND

Dehydration, starvation, and enhanced blood coagulability may occur during labor.

METHODS

We studied 60 women who gave birth vaginally to a healthy singleton infant at term. Sampling of urine and blood specimens was performed on admission to the hospital with labor pains and just after birth. Paired samples were available from 50 women for urine analysis and 29 women for blood analysis. Total fluid intake (oral and intravenous) during labor was recorded. Changes in various parameters in the urine and blood in relation to the total fluid intake were analyzed.

RESULTS

Osmolality and creatinine concentration in the urine, red blood cell count, hemoglobin concentration, hematocrit value, thrombin-antithrombin III complex, plasmin-alpha 2-plasmin inhibitor complex and D dimer significantly increased during labor. Ketone bodies were absent in the urine in 84% (42/50) of women on admission to the hospital whereas these were present in 74% (37/50) of women just after delivery (p < 0.01). The degree of these changes appeared to be smaller with an increase in fluid intake.

CONCLUSION

Concentrated urine, hemoconcentration, starvation, and activation of the thrombogenic and fibrinolytic system occur in parturient women. Sufficient fluid intake during labor may ameliorate these unfavorable changes.

Chorion laeve trophoblasts of preeclamptic fetal membranes: histochemically detectable enzyme activities do not change at a subcellular level

We examined the subcellular localization of ADP-degrading activity and cytochrome c oxidase (CCO) activity in chorion laeve trophoblasts from term and near term human fetal membranes, and compared them with those from severe preeclamptic fetal membranes. The methods used for the detection of enzyme activities were the lead nitrate method for ADP-degrading activity and the diaminobenzidine method for CCO. Precipitates indicative of ADP-degrading activity were visible on surface microvillous plasma membranes of chorion laeve trophoblasts both from normal and preeclamptic fetal membranes. The intensity and distribution patterns were the same in the normal and preeclamptic subjects. CCO labeling was visible in almost all laeve trophoblastic mitochondria both in normal and preeclamptic cases. Previously, we demonstrated that in preeclamptic villous trophoblasts there were decreases in ADP-degrading activity and the presence of CCO-negative mitochondria, which were proposed to lead to dysfunction of each villous trophoblast, and finally to placental insufficiency in preeclampsia. Reductions or changes in enzyme intensities/distribution patterns, which are characteristic features of preeclamptic villous trophoblasts, were absent in chorion laeve trophoblasts in preeclampsia. These results suggest that in preeclampsia there are no, or at least less severe, abnormalities in the enzyme activities of chorion laeve trophoblasts, compared with villous trophoblasts, as far as enzyme-histochemically detectable enzymes are concerned.

Magnetic resonance analysis of abnormal diaphragmatic motion in patients with emphysema

The purpose of this study was to quantitatively evaluate paradoxical diaphragmatic motion using magnetic resonance (MR) imaging. A total of 27 subjects were examined, including 12 normal young adults, six control individuals, and nine patients with emphysema. With subjects in the supine position, 30 sequential sagittal MR images of the entire right lung were obtained during tidal and deep slow breathing. Diaphragmatic movement between sequential images was estimated as the displacement area and the total diaphragmatic movement in a respiratory cycle was calculated. The paradoxical motion of the diaphragm, representing the inverted movement to increase or decrease lung area, since paradoxical movement ratio (Mpr=(total paradoxical diaphragmatic movement/total diaphragmatic movement)x100), was evaluated. In patients with emphysema, paradoxical diaphragmatic motion was observed on MR images during deep breathing. The mean Mpr in emphysematous patients during deep breathing was 10+/-4%, which was significantly higher than 0.5+/-0.2% in young adults (p<0.05), and 1.2+/-0.6% in aged-matched controls (p<0.05). The present results indicate that magnetic resonance images could be used to detect paradoxical diaphragmatic motion in patients with emphysema.

Soymilk products affect ethanol absorption and metabolism in rats during acute and chronic ethanol intake

In this study we evaluated the effects of soy products on ethanol metabolism during periods of acute and chronic consumption in rats. Gastric ethanol content and blood ethanol and acetaldehyde concentrations were investigated after the oral administration of ethanol (34 mmol/kg) plus soy products such as soymilk (SM) or fermented soymilk (FSM). The gastric ethanol concentration of the FSM group was greater than that of the control group, whereas portal and aortal blood ethanol concentrations of the FSM group were lower than in controls. The aortal acetaldehyde concentration in the FSM group was lower than that of the control group. The direct effect of isoflavones on liver function was investigated by using hepatocytes isolated from untreated rats. Genistein (5 micromol/L) decreased ethanol (P = 0.045) and tended to decrease acetaldehyde (P = 0.10) concentrations in the culture filtrate. Some variables of ethanol metabolism in the liver were investigated after chronic ethanol exposure for 25 d. Rats consumed a 5% ethanol fluid plus the SM diet, the FSM diet or a control diet. Microsomal ethanol oxidizing activity was significantly lower in the FSM group than the control group. Furthermore, cytosolic glutathione S-transferase activity was higher in the SM and FSM groups than in the control group. Acetaldehyde dehydrogenase activity (low K(m)) in the FSM group (P = 0.15), but not in the SM group (P = 0.31), tended to be greater than in the control group. The amount of thiobarbituric acid reacting substances in the liver of the SM and FSM groups tended to be less than that of the control group (P = 0.18 and 0.10, respectively). These results demonstrate that soymilk products inhibit ethanol absorption and enhance ethanol metabolism in rats.