Secondary Fish-Odor Syndrome Can be Acquired by Nitric Oxide-mediated Impairment of Flavin-containing Monooxygenase in Hepatitis B Virus-Infected Patients

Primary fish-odor syndrome (FOS) is a genetic disorder caused by defective flavin-containing monooxygenase 3 gene (FMO3) with deficient N-oxidation of trimethylamine (TMA), causing trimethylaminuria (TMAU). By contrast, secondary FOS can be acquired by decreased FMO activities in patients with chronic liver diseases, but the underlying mechanisms are unknown. In the present study, we examined plasma NOx concentrations and viral DNA contents as well as in vivo FMO activities and their correlations in chronic viral hepatitis (CVH) patients. Plasma concentration of NOx was significantly increased by 2.1 fold (56.2+/-26.5 vs. 26.6+/-5.4micrometer, p< 0.01), and it was positively correlated with plasma hepatitis B virus (HBV) DNA contents (r2=0.2838, p=0.0107). Furthermore, the elevated plasma NOx values were inversely and significantly correlated with in vivo FMO activities detected by ranitidine-challenged test (8.3% vs. 20.0%, r2=0.2109, p=0.0315). TMA N-oxidation activities determined in CVH patients without challenge test were also significantly low (73.6% vs. 95.7%, p< 0.05). In conclusion, these results suggested that secondary FOS could be acquired by the endogenously elevated NO in patients with CVH.

Correlation of the Serum Nitrate/Nitrite Level with the Severity of Biliary Tract Inflammation

PURPOSE: The relationship between the biophysical and biochemical processes of gallbladder bile and nitric oxide is still not well known. In this study, the correlation between nitric oxide production and the degree of biliary tract inflammation was investigated and the levels of nitrate/nitrite (NOx) and stable metabolite of nitric oxide in the serum proposed for assessing the severity of biliary tract inflammation. METHODS: Eighty two patients with biliary tract inflammation who underwent operative treatment between March and July 2002 were included in this study. Of the 82 patients, there were 31 and 51 men and women, respectively. The mean age was 53, ranging from 21 to 82 years. The subjects were divided into three groups, GB stone (n=42), and acute cholecystitis (n=27), and cholangitis (n= 13). The severity of biliary tract inflammation was assessed using the WBC count, total bilirubin count, GB wall thickness on pathology, bile duct stone detected on ultrasonography, open conversion of cholecystectomy, pyrexia and tenderness/rebound tenderness on physical examination. The serum NOx concentrations were analyzed according to the groups, clinicopathological, laboratory and radiological findings. The serum NOx levels were measured using the Griess reaction after conversion of all nitrates to nitrites. RESULTS: The nitrate/nitrite levels in the GB, acute cholecystitis and cholangitis groups were 70.0+/-44.6, 126.8+/-54.5 and 142.0+/-44.6mumol/L, respectively, with statistical differences between the three groups (P< 0.05). The NOx level in patients with pyrexia, hyperbilirubinemia, leukocytosis, GB wall thickness on pathology and open conversion were markedly increased compared with the control group (P<0.05). These data demonstrate the relationship between the intensity of nitric oxide and the severity of biliary tract inflammation. CONCLUSION: Measurement of the NOx concentration in patients with biliary tract inflammation provides information about the severity and course of the disease. These results suggest there is a correlation between nitric oxide and the degree of biliary tract inflammation.

Alteration of Substrate Specificity by Common Variants, E158K/E308G and V257M, in Human Hepatic Drug-metabolizing Enzyme, Flavin-containing Monooxygenase 3

Our earlier studies found a significant correlation between the activities of ranitidine N-oxidation catalyzed by hepatic flavin-containing monooxygenase (FMO) and the presence of mutations in exon 4 (E158K) and exon 7 (E308G) of the FMO3 gene in Korean volunteers. However, caffeine N-1 demethylation (which is also partially catalyzed by FMO) was not significantly correlated with these FMO3 mutations. In this study, we examined another common mutation (V257M) in exon 6 of FMO3 gene. The V257M variant, which is caused by a point mutation (G769A), was commonly observed (13.21% allele frequency) in our subjects (n=159). This point mutation causes a substitution of Val257 to Met257, with transformation of the secondary structure. The presence of this mutant allele correlated significantly with a reduction in caffeine N-1-demethylating activity, but was not correlated with the activity of N-oxidation of ranitidine. In a family study, the low FMO activity observed in a person heterozygous for a nonsense mutation in exon 4 (G148X) and heterozygous for missense mutation in exon 6 (V257M) of FMO3 was attributed to the mutations. Our results suggest that various point mutations in the coding regions of FMO3 may influence FMO3 activity according to the probe substrates of varying chemical structure that correlate with each mutation on the FMO3 gene.

Reduced Messenger RNA Expression of the Neuronal Nitric Oxide Synthase Gene in Infantile Hypertrophic Pyloric Stenosis

PURPOSE: Nitric oxide synthesized by neuronal nitric oxide synthase (nNOS) has been described as a mediator of smooth muscle relaxation in the mammalian gastrointestinal tract. Impaired expression of the nNOS gene is suggested in the development of infantile hypertrophic pyloric stenosis (IHPS). We examined the expression of nNOS mRNA in pyloric muscle biopsy specimens obtained from 8 patients with IHPS and attempted to correlate the results with the clinical characteristics. METHODS: The expression of nNOS mRNA in pyloric muscle biopsy specimens for 8 patients with IHPS was examined using a reverse transcription- polymerase chain reaction (RT-PCR) technique. For the control, a smooth muscle layer specimen of a neonate with a normal pylorus was used. RESULTS: In the control specimen, the level of nNOS mRNA expression was 48.4% of beta-actin mRNA. In the two thinnest (each 3 mm) of pyloric muscle thicknesses as determined by ultra-sonography, the expressed nNOS mRNA were 16.7% and 30.3%. The two thickest (each 8.3 mm) expressed as 35.3% and 22.9% nNOS. The two samples from the earliest age of symptomatic onset (1 day, 7 days after birth) expressed as 25.6% and 4.8%. The two from the latest age of onset (each 30 days) expressed as 7.4% and 10.5%. The control specimen revealed a higher level of nNOS mRNA expression than those of the IHPS specimens. There was no significant correlation between the clinical characteristics and the levels of nNOS mRNA in the IHPS specimens. CONCLUSION: Since a low level of nNOS mRNA expression may lead to impaired production of NO, our observations indicate that the hypertrophic pyloric muscle of an IHPS patient may be the result of a reduced expression of the nNOS gene at the mRNA level. In IHPS patients, there was no correlation between the clinical characteristics and the levels of expressed nNOS mRNA.

An Effect of Health Promotion Program in Mid-life Women / 간호학회지

The purpose of the study was to test the effect of the health promotion program in middle women. The research design was a quasi experimental, nonequivalent control-group pretest-posttest design. The data were collected from February 24 to April 14, 1988. The subjects were midlife women, age 40 to 50 years who reside in Chonju city. The experimental group consisted of 41 subjects and the control group 40 subjects. The instruments used for the study were the Self Efficacy Scale and the Health Promotion Behavior Scale developed by Park(1995). The data was analyzed by SPSS/PC. The study result were as follows: Through the 7 week education program for health promotion, self efficacy and health behavior were effectively changed in middle-aged.

Assessment of flavin-containing monooxygenase (FMO) activity by determining urinary ratio of theobromine and caffeine in a Korean population after drinking a cup of coffee

To examine individual variation in drug metabolism catalyzed by flavin-containing monooxygenase (FMO), 179 Korean volunteers' urinary molar concentration ratio of theobromine (TB) and caffeine (CA) was determined. Their urine was collected for 1 hr (between 4 and 5 hrs) after they drank a cup of coffee containing 115 mg CA and analyzed by an HPLC system. The lowest TB/CA ratio obtained was 0.40, the highest ratio was 15.17 (38-fold difference), and the median ratio for all subjects was 1.87. The mean was 2.66 with 2.36 S.D.. In 134 nonsmokers, the mean ratio was 2.35 +/- 1.93, that of 51 males was 2.30 +/- 2.26 and 83 females was 2.37 +/- 1.85, respectively. There was no significant gender difference in the obtained TB/CA ratio (Mann-Whitney test; p=0.518). There were no smokers among the 83 female volunteers. In the remaining 96 male subjects, the ratio obtained in 51 nonsmokers was 2.30 +/- 2.06 and that of 45 smokers was 3.62 +/- 3.19. This indicated that the TB/CA ratio was increased significantly in smokers (p=0.007). However, when the TB/CA ratios (FMO activity) obtained in all 179 Korean volunteers are compared with the urinary concentration ratios of paraxanthine (PX) plus 1,7-dimethylurate (17U) to CA (CYP1A2 activity), there was a weak but significant correlation (Pearson's correlation coefficient test; r2=0.28, p<0.0001). This indicates that, although the urinary TB/CA ratio mostly represents FMO activity, minor contribution by CYP1A2 activity cannot be ignored. In conclusion, the FMO activity measured by taking the urinary TB/CA ratio from normal healthy Korean volunteers shows marked individual variations without significant gender differences and the increased TB/CA ratio observed in cigarette smokers may have been caused by the increased CYP1A2 activity.

Ethanol prevents from acetaminophen inducible hepatic necrosis by inhibiting its metabolic activation in mice

Concomitant administration of a single acute dose of ethanol (4 g/kg) protected mice from the hepatocellular injury observed upon administration of a large dose of acetaminophen (400 mg/kg). This was evidenced by the normal histological appearances of liver sections and by the lowered serum aminotransferase activities in mice treated with ethanol and acetaminophen together. In the mice treated with acetaminophen alone, along with the hepatic necrosis, the hepatic microsomal aminopyrine N-demethylase activity was decreased. However, co-administration of ethanol prevented this acetaminophen dependent inhibition on the microsomal mixed function oxidase activity. Pharmacokinetic studies indicated that the concentration of un-metabolized drug in the blood was increased in the ethanol treated mice. Furthermore, upon co-administration of ethanol, although the biliary levels of acetaminophen metabolites (glucuronide, sulfate and cysteine conjugates) were decreased, the level of unmetabolized acetaminophen was increased. Our findings suggest that co-administration of an acute dose of ethanol reduces the degree of hepatocellular necrosis produced by a large dose of acetaminophen and this ethanol dependent protection is, in major part, afforded by suppression of the hepatic microsomal mixed function oxidase activity catalyzing the metabolic activation of acetaminophen.

Thiobenzamide S-oxidation in perfused rat liver: Ex vivo determination of hepatic flavin-containing monooxygenase activity

An ex vivo assay determining the flavin-containing monooxygenase (FMO) activity in perfused rat liver has been developed by assessing the rate of thiobenzamide S-oxide (TBSO) formation from the infused thiobenzamide (TB). The hepatotoxicity by TB or TBSO was not a critical factor for maintaining the FMO activity for up to 50 min. The FMO activity expressed in nmoles TBSO produced/g liver/min was the same for the recycling and non-recycling perfusion. This implies that reduction of the oxidized TBSO back to the parent compound (TB) is negligible. Hydrolysis of the collected perfusates with either beta-glucuronidase or arylsulfatase did not increase the TBSO level and thus, TBSO does not appear to undergo conjugation either to glucuronide or sulfate esters. Thus, measuring the rate of TB S-oxidation in the isolated perfused liver with 1 mM TB for 50 min provides a useful tool for evaluation of the hepatic FMO activity in the absence of hepatic necrosis and without the interferences caused by further conjugation or back reduction of the TBSO to the parent TB.

Enhancement of O-dealkylation in Mouse Liver by Dietary Administrations of BHA and BHT: Studies with Isolated Perfused Livers and Hepatic Microsomes

Effects of feeding 2(3)-tert-butyl 4-hydroxyanisole (BHA) and 3, 5-di-tert-butyl 4-hydroxytoluene (BHT) on the rates of mixed function oxidation and conjugation enzyme reactions have been determined using isolated hepatic microsomal fractions and isolated perfused livers of mice. The treatments with either of the antioxidants have increased the rates of O-demethylation for p-nitroanisole and of O-deethylation for 7-ethoxycoumarin up to 2-fold, both in microsomes and in perfused liver. Analysis of the perfusate showed that the increased amounts of p-nitrophenol and 7-hydroxycoumarin produced by the elevated mixed-function oxidase activities were reflected by the increase in the amounts of glucuronide conjugates and not in the increase for the amounts of the sulfate ester conjugates. Comparison of results also indicated that in the perfused liver, the maximal rate of metabolite conjugation is limited by the maximal rates of the initial mixed function oxidase activities.

Enhancements of Mouse Hepatic Cytosol Enzyme Activities Involved in UDP-Glucuronic Acid Synthesis, Glutathione Reduction and Conjugation with Butylated Hydroxyanisole (BHA) and Its Structural Analogs

Activities of hepatic cytosol enzymes involved in UDP-g1ucuronic acid synthesis as well as in glutathione reduction and conjugation systems were determined following administrations of butylated hydroxyanisole (approximately 5 mmol/kg body weight/day) and of equimolar intake doses of its structural anglogs. These compounds included the multi-functional group side chain compounds (t-butyl hydroquinone, 4-hydroxy- anisole, hydroquinone, benzoquinone) and the mono-functional side chain compounds (t-butyl benzene, anisole, phenol). They were administered to mice for 10 days either by mixing them in the diet or by oral intubations. Results showed that glutathione Stransferase activities were markedly increased by all tested compounds except for the t-butyl benzene. Activities of glutathione reductase and glucose 6-phosphate dehydrogenase were increased together on1y by BHA and t-butyl hydroguinone. UDP-glucose dehydrogenase and NADH:quinone reductase activities were significantly elevated by the multi-functional side chain compounds, but not by the mono-functional analogs. The relations between chemical structures of tested BHA analogs and elevations of the measured hepatic cytosol conjugation (detoxification) system enzyme activities for the metabolism and excretion of BHA analogs are discussed.