Modeling of Human Hepatic and Gastrointestinal Ethanol Metabolism with Kinetic-Mechanism-Based Full-Rate Equations of the Component Alcohol Dehydrogenase Isozymes and Allozymes

Alcohol dehydrogenase (ADH) is the principal enzyme responsible for the metabolism of ethanol. Human ADH constitutes a complex family of isozymes and allozymes with striking variation in kinetic properties and tissue distribution. The liver and the gastrointestinal tract are the major sites for first-pass metabolism (FPM). The quantitative contributions of ADH isozymes and ethnically distinct allozymes to cellular ethanol metabolism remain poorly understood. To address this issue, kinetic mechanism and the steady-state full-rate equations for recombinant human class I ADH1A, ADH1B (including allozymes ADH1B1, ADH1B2, and ADH1B3), ADH1C (including allozymes ADH1C1 and ADH1C2), class II ADH2, and class IV ADH4 were determined by initial velocity, product inhibition, and dead-end inhibition experiments in 0.1 M sodium phosphate at pH 7.5 and 25 °C. Models of the hepatic and gastrointestinal metabolisms of ethanol were constructed by linear combination of the numerical full-rate equations of the component isozymes and allozymes in target organs. The organ simulations indicate that in homozygous ADH1B*1/*1 livers, a representative genotype among ethnically distinct populations due to high prevalence of the allele, major contributors at 1 to 10 mM ethanol are ADH1B1 (45% to 24%) and the ADH1C allozymes (54% to 40%). The simulated activities at 1 to 50 mM ethanol for the gastrointestinal tract (total mucosae of ADH1C*1/*1-ADH4 stomach and the ADH1C*1/*1-ADH2 duodenum and jejunum) account for 0.68%-0.76% of that for the ADH1B*1/*1-ADH1C*1/*1 liver, suggesting gastrointestinal tract plays a relatively minor role in the human FPM of ethanol. Based on the flow-limited sinusoidal perfusion model, the simulated hepatic K_m^app, V_max^app, and C_i at a 95% clearance of ethanol for ADH1B*1/*1-ADH1C*1/*1 livers are compatible to that documented in hepatic vein catheterization and pharmacokinetic studies with humans that controlled for the genotypes. The model simulations suggest that slightly higher or similar ethanol elimination rates for ADH1B*2/*2 and ADH1B*3/*3 individuals compared with those for ADH1B*1/*1 individuals may result from higher hepatocellular acetaldehyde.

Ethanol oxidation and the inhibition by drugs in human liver, stomach and small intestine: Quantitative assessment with numerical organ modeling of alcohol dehydrogenase isozymes

Alcohol dehydrogenase (ADH) is the principal enzyme responsible for metabolism of ethanol. Human ADH constitutes a complex isozyme family with striking variations in kinetic function and tissue distribution. Liver and gastrointestinal tract are the major sites for first-pass metabolism (FPM). Their relative contributions to alcohol FPM and degrees of the inhibitions by aspirin and its metabolite salicylate, acetaminophen and cimetidine remain controversial. To address this issue, mathematical organ modeling of ethanol-oxidizing activities in target tissues and that of the ethanol-drug interactions were constructed by linear combination of the corresponding numerical rate equations of tissue constituent ADH isozymes with the documented isozyme protein contents, kinetic parameters for ethanol oxidation and the drug inhibitions of ADH isozymes/allozymes that were determined in 0.1 M sodium phosphate at pH 7.5 and 25 °C containing 0.5 mM NAD(+). The organ simulations reveal that the ADH activities in mucosae of the stomach, duodenum and jejunum with ADH1C*1/*1 genotype are less than 1%, respectively, that of the ADH1B*1/*1-ADH1C*1/*1 liver at 1-200 mM ethanol, indicating that liver is major site of the FPM. The apparent hepatic KM and Vmax for ethanol oxidation are simulated to be 0.093 ± 0.019 mM and 4.0 ± 0.1 mmol/min, respectively. At 95% clearance in liver, the logarithmic average sinusoidal ethanol concentration is determined to be 0.80 mM in accordance with the flow-limited gradient perfusion model. The organ simulations indicate that higher therapeutic acetaminophen (0.5 mM) inhibits 16% of ADH1B*1/*1 hepatic ADH activity at 2-20 mM ethanol and that therapeutic salicylate (1.5 mM) inhibits 30-31% of the ADH1B*2/*2 activity, suggesting potential significant inhibitions of ethanol FPM in these allelotypes. The result provides systematic evaluations and predictions by computer simulation on potential ethanol FPM in target tissues and hepatic ethanol-drug interactions in the context of tissue ADH isozymes.

First Report of Aspergillus niger Causing Root Rot of Peanut in China

Peanut (Arachis hypogaea) is one of the most important oil crops and food legumes worldwide. China sows approximately 3.5 million hectares each year and produces 40% of the world's peanuts. Fungal diseases are among the main biotic stresses affecting peanut production. Root rot is a serious disease caused by several fungi. Pythium spp., Fusarium spp., and Rhizopus spp. are some of the root rot fungi that have been reported in China. In 2012 and 2013, root rot symptoms were observed in several fields in Laixi District, Qingdao City, Shandong Province, China. The first symptoms appeared in July. Initial symptoms of the disease were brown spots on the stem base and root. Affected plants were stunted, with leaf chlorosis, reduced growth, or sudden wilting. As disease progressed, the infected tissues showed brown discoloration and rot, and abundant dark brown and black powdery spores were visible on the surfaces of affected parts. Eventually, affected plants collapsed and died. To isolate the causal organism, roots and stems were cut into sections, which were surface-disinfected with 70% ethanol solution (v/v) for 20 s, soaked in 0.1% mercuric chloride solution for 50 s, rinsed with sterilized water three times, dried, placed on Czapek's Dox agar supplemented with chloramphenicol (100 μg/ml), and incubated at 28°C for 7 days. Fungal colonies were white initially and then covered with a dense layer of dark brown or black conidial heads. The conidial head was radiate; vesicles were nearly spherical and covered with irregular metulae and phialides. Conidia were globose or subglobose (3.0 to 5.5 μm in diameter), dark brown to black, with rough cell walls. Total genomic DNA was extracted from mycelia using the EasyPure Genomic DNA Kit (TransGEN, Beijing, China). The rDNA-ITS region was amplified using PCR with the universal fungal primers ITS1 and ITS4 (2). The purified products were separately sequenced in both directions using the same primer pair. The sequences (GenBank Accession No. KJ848716) obtained were 99% similar to the ITS sequence of isolates of Aspergillus niger. This, together with the morphological characters (1) described above, suggested that the microorganism we had isolated was A. niger. Koch's postulates were completed in the laboratory by inoculating peanut. Thirty Huayu20 peanut seeds were placed in a 500-ml sterile pot with 300 g of autoclaved soil. Twenty days after seedling emergence, 15 peanut plants were wounded with a needle and inoculated with 5 ml of conidia suspension (10⁶ ml^-1). The same number of peanuts were similarly wounded and inoculated with 5 ml of sterile distilled water to serve as controls in the same pot. All peanuts were kept in a randomized complete block design at 30°C under a 12-h photoperiod. After 7 days, disease symptoms similar to those observed in the field appeared in all inoculated but not in non-inoculated peanuts. The tests were repeated three times in the greenhouse. Koch's postulates were satisfied after re-isolating the A. niger from inoculated peanuts using the method described above. To our knowledge, this is the first report of A. niger causing root rot in peanut in China. References: (1) M. A. Klich. Page 12 in: Identification of Common Aspergillus Species. Centraalbureau voor Schimmelcultures, Utrecht, The Netherlands, 2002. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

Potential modulation on P-glycoprotein and CYP3A by soymilk and miso: in vivo and ex-vivo studies

P-glycoprotein (P-gp) and CYP3A4 both play very important roles in drug bioavailability, resistance and interactions. Our in vitro studies indicated that P-gp function was activated by many isoflavones. This study investigated the in vivo effects of soymilk and miso, isoflavone-rich soy foods, on P-gp and CYP3A by tracing the pharmacokinetics of cyclosporine (CSP), a probe drug of P-gp. Rats were orally administered CSP with and without soymilk or miso. A specific monoclonal fluorescence polarisation immunoassay was used to determine the blood concentration of CSP. The results showed that soymilk and miso significantly decreased the C(max) of CSP by 64.5% and 78.3%, and reduced the AUC(0-540) by 64.9% and 78.3%, respectively. Mechanism studies revealed that the activities of P-gp and CYP3A4 were induced by soymilk and miso. In conclusion, ingestion of soymilk and miso significantly activated the functions of P-gp and CYP3A.

Rhizoctonia solani Identified as the Disease Causing Agent of Peanut Leaf Rot in China

Peanut (Arachis hypogaea L.) is one of the most economically important oil crops in the world. Since the 1990s, the peanut industry has developed rapidly in China. However, because of the use of high-yield varieties and increased plant density, a peanut leaf rot disease occurred in Laixi Experimental Fields in Shandong Province, China in 2007. Leaves had nearly circular, brown lesions that enlarged quickly developing yellow-brown halos at the edges of the lesions. High relative humidity under field conditions led to complete necrosis of the leaves with cotton wool-like mycelia observed followed by the development of sclerotia on the leaf surface. Symptomatic plants were observed between 2007 and 2010, and symptomatic leaf tissue was collected from the Laixi Experimental Fields. An isolate (designated YF-1) from symptomatic peanut leaves was isolated and purified on potato dextrose agar (PDA) and water agar (WA) medium. On PDA, the colony appeared initially as colorless and grew to the diameter of a 9-cm petri dish within 3 days. As the mycelium aged, the colony color gradually became light brown, and sclerotia developed on the surface of the colony. YF-1 was identified as Rhizoctonia solani Kühn based on the number of nuclei per cell ranging from 4 to 13 (average 6.1), hyphal diameter being 7.5 to 12.9 μm (average 8.3 μm), branching at right angles, a septum was present near each hyphal branch with a slight constriction, and no clamp connection structures or conidia were ever observed (4). To further confirm the identity of isolate YF-1, genomic DNA was extracted using the DNeasy Plant Mini DNA Extraction Kit (Shanghai Leifeng Biotechnol. Co., Ltd.), and the complete internal transcribed spacer (ITS) region of ribosomal DNA was amplified and sequenced with a pair of primers ITS1/ITS4 (2). A GenBank BLAST search produced an exact match for the sequences of R. solani (AY154301), with 100% sequence similarity. To estimate the mode of anastomosis, YF-1 was paired on WA medium with each reference strain belonging to anastomosis groups (AGs) 1 through 8 (provided by Shandong Agriculture University) (1,3). The results indicated that YF-1 belonged to group AG-1, subgroup AG-1-IA of R. solani. Pathogenicity tests were conducted by inoculating 10 peanut leaves using a colonized paper disc method (filter paper 1 cm in diameter suspended in the mycelia suspension). Ten control leaves received paper discs without mycelium. Inoculated and non-inoculated plants were kept in humid chambers for 24 h at 25°C. Three days after inoculation, the leaves developed typical brown lesions that were similar to those of naturally diseased plants. Koch's postulates were fulfilled by reisolation of R. solani from symptomatic leaves. No symptoms were observed on control leaves. To our knowledge, this is the first report of peanut leaf rot caused by R. solani. Occurrence of the disease in China is a new threat to the health of peanut. References: (1) Y. X. Chen et al. Acta Phytopathol. Sin. 3:139, 1985. (2) T. Misawa and S. Kuninaga. J. Gen. Plant Pathol. 76:310, 2010. (3) A. Ogoshi. Ann. Phytopathol. Soc. Jpn. 38:117, 1972. (4) J. R. Jr. Pameter and H. S. Whitmey. UC Press. 135, 1970.

Molecular analysis of the coat protein gene of peanut stripe virus from China

Peanut stripe virus (PStV) is one of the most common viruses infecting peanut that causes great economic losses every year. The 3ʹ-terminal 1082 bp of 74 PStV isolates collected from 12 districts of Shandong province, China were sequenced. Their coat protein (CP) genes were 864 bp in length and shared identities of 98.0%~100% and 98.3% ~100% at nt and aa levels. The identities between the CP genes of these isolates and other 36 isolates from the GenBank were 93.5%~100% and 92.0%~100% at nt and aa levels, respectively. PStV isolates can be clustered into two phylogenetic groups. The isolates from United States, mainland China, and Indonesia formed group I and those from Viet Nam, Thailand, and Taiwan formed group II. The PStV isolates in group I can be further classified to two subgroups. The gene flow of PStV populations within a country was frequent, but that between countries was infrequent.

Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge

Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

Parental concerns for the child with febrile convulsion: long-term effects of educational interventions

OBJECTIVE

To evaluate long-term effects of educational interventions on parental concerns for children with febrile convulsions (FC).

SUBJECTS AND METHODS

209 FC parents were recruited from southern Taiwan, and assigned into program or pamphlet groups by their choices. A questionnaire was used to examine the parental concerns at 4 time points: prior to the interventions, 3 months, 1 year, and 2 years after the interventions.

RESULTS

The concern scores were high before the interventions. Parents concerned that their child is apt to get a fever, has further seizures in the night, that FC results in potential brain damage and is life threatening. After interventions the concern scores were significantly lower for the program group than for the pamphlet group. The educational program was the most significant factor that influenced the change in parental concerns. The recurrence of FC did not significantly influence the change in the concern trajectory in the program group but showed a significant difference in the pamphlet group.

CONCLUSION

FC parental concerns decreased as time passed particularly in the program group. The educational program was the significant factor that influenced the change of concern trajectories, and the recurrent/non-recurrent factor influenced the change of concern only in pamphlet group. FC parental concerns should be assessed, and information given combined with emotional support.

Risk factors for a first febrile convulsion in children: a population study in southern Taiwan

PURPOSE

To identify risk factors for a first febrile convulsion among 3-year-old children by a matched case-control population study.

METHODS

All 11,714 neonatal survivors born in Tainan City between October 1989 and September 1991 were enrolled. At age 3, 10,460 children were available for telephone survey for febrile convulsions, and were confirmed by home visit interviews. Those without history of seizure were randomly matched to each febrile convulsion case by age, gender, and residence district.

RESULTS

Two hundred fifty six children had febrile convulsions, and 218 of them and their matched controls were available for analysis. The febrile convulsion cases had significantly more febrile episodes (four or more) per year (33.0 vs. 22.5%; p = 0.021), and cases had a higher percentage of developmental delay (3.7 vs. 0.4%; p = 0.046) and a higher percentage of febrile convulsions in their siblings (12 vs. 0.4%; p = 0.011) than controls. The other sociodemographic, environmental, and biologic variables showed no differences between cases and controls. Step-wise logistic regression showed a highly significant independent association between febrile convulsions and history of febrile convulsions in the siblings, and a moderate one between febrile convulsions and the number of febrile episodes per year.

CONCLUSIONS

The presence of febrile convulsions in the siblings and the number of fever episodes per year were the independent and significant predictors of febrile convulsion for an individual case in our population-based sample.

Prevention of chronic lung disease in preterm infants by early postnatal dexamethasone therapy

Recent studies suggest that early dexamethasone therapy may lessen the pulmonary inflammation in preterm infants with respiratory distress syndrome (RDS). To investigate whether early (<12 hr) postnatal dexamethasone therapy would reduce the incidence of chronic lung disease (CLD), a randomized, double-blind, controlled trial was conducted in 40 infants (birth weights from 500 to 1,999 gm) who had severe RDS and required mechanical ventilation within 6 hr of birth. All infants received one dose of Survanta before they were randomly assigned to control (saline placebo) or dexamethasone-treated groups (0.5 mg/kg/d for 1 week, then tapered over 3 weeks). Sequential analysis was performed with the end point of assessment being the presence or absence of CLD on postnatal Day 28. Statistical significance favoring dexamethasone was reached when 12 consecutive pairs in which one infant had CLD and the other did not have CLD showed that ten pairs favored dexamethasone and two pairs favored control treatment. Among the survivors, 12/15 were extubated in the dexamethasone group and 9/16 in the control group at the end of study. Infants in the treated group had transient hyperglycemia and hypertension. There was no difference between the groups in mortality and in incidence of sepsis or intraventricular hemorrhage. We conclude that early postnatal dexamethasone therapy is potentially effective in the lessening of CLD in preterm infants. To substantiate our result, large randomized controlled trials are needed and warranted.

Potential value of urinary intercellular adhesion molecule-1 determination in patients with bladder cancer

OBJECTIVE

Intercellular adhesion molecule-1 (ICAM-1) is known to play a role in immunity against bladder cancer and can be detected in the supernatants of cultured bladder cancer cells that constitutively express ICAM-1. This study was performed to examine the relevance of the ICAM-1 urine test in patients with bladder cancer.

METHODS

A total of 53 patients with bladder carcinoma, 35 with history of bladder cancer, and 30 normal control subjects were included in this analysis. Urinary ICAM-1 (ulCAM-1) levels were measured by immunoassay and corrected for hydration status.

RESULTS

Levels of ulCAM-1 were significantly elevated in patients with bladder cancer or those at tumor-free status compared with normal control subjects (P=0.001). However, there was no apparent difference between the two groups of urothelial disorders (P >0.1). ulCAM-1 did not correlate with clinicopathologic variables of bladder cancer or patient outcome (P >0.1). Six patients at tumor-free status had multiple ulCAM-1 determinations during the study period. Three of these 6 patients had elevated ulCAM-1 levels and proved to have recurrent tumors; 3 of the 6 had stable ulCAM-1 levels and were still free of disease.

CONCLUSIONS

Our results suggest that urinary excretion of ICAM-1 is elevated in the early stage of bladder carcinogenesis, but is independent of biologic properties of bladder cancer. Serial monitoring of ulCAM-1 may be helpful in selecting patients who are at risk of tumor recurrence.

Urinary excretion of transforming growth factor-alpha in patients with transitional cell carcinoma

This study was performed to examine the involvement of transforming growth factor-alpha (TGF-alpha) in urothelial tumorigenesis. TGF-alpha urine levels were measured in patients with urothelial carcinoma (n = 68), patients who were tumor-free (n = 58), patients with non-neoplastic inflammatory disease (n = 20), and normal controls (n = 39). Both inflammatory and neoplastic urologic diseases had elevated TGF-alpha urine levels (169.5 ng/gm and 116.7 ng/gm, respectively) as compared to normal controls (39.1 ng/gm) (P = 0.0001). For patients with active cancer, TGF-alpha levels were positively associated with histologic grading (P = 0.009), nodular shape, expression of epidermal growth factor receptor in primary tumor (P = 0.03, respectively). But, there was no important relationship with staging classification, number and size of tumor (P > 0.1, respectively). TGF-alpha urine levels did not correlate with the serum content (n = 26; P > 0.5), or the immunohistochemical expression of TGF-alpha (n = 60) in corresponding tumor (P < 0.05, 0.1). Significant factors in predicting patient survival were clinical staging, nodular shape and size of tumor (P < 0.05, respectively). Our data implies that interaction of urinary TGF-alpha/urothelial epidermal growth factor receptor may play a positive role in the carcinogenesis of human urothelium.

[Study of effects of Chinese herbal prescription combined with copper, iron on malignancy of cancer cells]

BALB/c mice bearing ascitic liver cancer were used, and Chinese herbal prescriptions combined with Cu and Fe (CHCF) was given by gavage continuously for 10 days, and some cell biological parameters were measured; furthermore, the ascitic cancer cells (control and treated group) were removed, and retransplanted to another mice and observed. The results showed that in CHCF treated group, DNA content of the cancer cells was decreased, and the proliferation index (PI) was reduced (control: 83.4 +/- 2.6, CHCF group: 78.8 +/- 1.5; or control: 67.2 +/- 1.3, CHCF group: 64.2 +/- 1.6, P < 0.05). The number of the cancer cells in G1 phase increased obviously, but, those of S+G2M phases decreased considerably (P < 0.05-0.01); on the DNA histogram, the diploid peak became higher and bigger, but multiploid peaks became smaller. Furthermore, retransplanted experiments showed that in 2/10 animals, the tumor did not grow, the growth inhibition rate was 71.7%-88.3%; and the survival period of retransplanted animals was prolonged significantly (from 26.1 +/- 11.8 days to 38.1 +/- 9.6 days, or to 39.6 +/- 7.2 days, P < 0.01); the increase in life span was 46%-52% respectively. These results suggested that CHCF could decrease the malignancy of liver cancer cells in mice.

Expression of c-erbB-2 protein in normal and neoplastic urothelium: lack of adverse prognostic effect in human urinary bladder cancer

The clinical significance of c-erb B-2 expression in urinary bladder cancer remains controversial. We performed an immunohistochemical study to examine the expression of c-erb B-2 in non-neoplastic urothelium (n = 12) and transitional cell carcinoma of the urinary bladder (n = 82). c-erb B-2 protein was localized in superficial and some intermediate cells of non-neoplastic urothelium. A total of 29 out of 82 (35%) tumors were positive for c-erb B-2 over-expression. There was no significant association of c-erbB-2 expression with tumor grade (p = 0.12), stage (p = 0.93), DNA ploidy status (p = 0.56) and the sex of patients (p = 0.5). Expression of epidermal growth factor receptor and Ki-67 index was available in 33 cases. Both parameters showed no apparent association with c-erbB-2 expression (p = 0.53 and 0.58 respectively). Factors correlated with poor patient survival by univariate analysis were tumor stage (p = 0.0001), tumor grade (p = 0.001), development of second recurrence (p = 0.002) and negative expression of c-erbB-2 (p = 0.017). Important indicators associated with first recurrence were tumor stage (p = 0.028), and c-erbB-2 expression with the risk of second recurrence (p = 0.031). Multivariate survival analysis revealed that tumor stage was among the most important prognostic factors (p = 0.029), followed by tumors without c-erbB-2 expression (p = 0.031) with a median follow-up at 46 months. The age of patients and c-erbB-2 expression were significantly associated with developing second recurrence (p = 0.031 and 0.046 respectively). The results indicate that expression of c-erbB-2 is independent of the stage and grade of bladder cancer. Although c-erbB-2 status can discriminate subpopulations with a high risk of recurrence, evaluation of its expression in paraffin-embedded tumors does not indicate poor prognosis for patients with urinary bladder cancer. To address this discrepancy a better understanding of the regulatory mechanism and physiological properties of c-erbB-2 protein in urothelium is required.