External biliary drainage plus bile acid feeding is not equal to internal drainage in preserving the cellular immunity following prolonged obstructive jaundice

This study investigates the importance of intestinal bile flow in cellular immunity. Sprague-Dawley rats undergoing bile duct ligation (BDL) and sham ceiliotomy (Sham) for 14 and 21 days were investigated. Experimental animals following BDL were further divided into an external drainage (ED) group, an ED group with rat chow mixed with 2:2:1 cholic acid, chenodeoxycholic acid, and deoxycholic acid (ED + BF), and an internal drainage (ID) group. Fourteen days later, they were killed and analyzed for spleen lymphocytic [3H] thymidine uptake (LHU) under mitogen stimulation with phytohemagglutinin, blood biochemistry, hemogram, and liver pathology. In the 14-day BDL experiment, LHU and serum albumin level were decreased in the BDL group (P < 0.05). After drainage, they were not significantly different among sham, ED, ED + BF, and ID groups. In the 21-day BDL experiment, the red cell volume was decreased (P < 0.05). After drainage, the ED, ED + BF, and ID groups still had a significantly lower LHU than the sham group (P < 0.05). However, the ID group had higher LHU than the ED and ED + BF groups (P < 0.05). The ED + BF group had a slightly higher LHU than the ED group but not statistically significant. Liver pathology returned to normal after drainage in the 14-day BDL model. In contrast, the 21-day BDL group had prominent periportal necrosis and developed periportal fibrosis after drainage. The present study reveals the duration of BDL determines the severity of hepatic damage. In the 14-day BDL groups, all kinds of drainage completely reverse the impaired liver function and cellular immunity. In the 21-day BDL group, 14-day drainage is inadequate for recovery because irreversible pathological changes are found. The reversal of cellular immunity in ID is better and faster, because it provides a better hepatic functional, nutritional, and hematological recovery besides the presence of primarily secreted bile acids.

Role of AKT kinase in sphingosine-induced apoptosis in human hepatoma cells

Our previous work has shown that a number of sphingolipid metabolites including sphingosine, sphinganine, and other long-chain bases potently induced apoptosis in human hepatoma cells. In this study, we examined the possibility that sphingosine may trigger apoptosis in human hepatoma cells via inhibition of anti-apoptotic pathways. We investigated the effect of sphingosine on AKT kinase, a serine/threonine kinase which was found to protect cells from apoptosis induced by a variety of extracellular stresses. Our results indicated that sphingosine inhibited basal and serum-stimulated AKT kinase activity in a dose-dependent manner in hepatoma cells. Additionally, sphingosine-induced inhibition of AKT kinase was correlated with induction of apoptosis in these cells. Pretreatment of insulin, a potent stimulator of AKT kinase, partially reversed the inhibition of AKT kinase by sphingosine and counteracted the apoptotic action of this sphingolipid. Expression of activated AKT kinase partially protected cells from sphingosine-induced apoptosis, whereas expression of kinase-dead AKT kinase had no effect. The molecular mechanism by which AKT kinase suppressed the apoptotic action of sphingosine was investigated. Our results showed that increased release of cytochrome C from mitochondria and subsequent activation of caspase-3 were detected in sphingosine-treated hepatoma cells. On the contrary, expression of activated AKT kinase in Hep3B cells attenuated cytochrome C release and caspase-3 activation induced by sphingosine. Taken together, these findings suggest that suppression of AKT kinase is one of the mechanisms by which sphingosine induces apoptosis in hepatoma cells and activation of AKT kinase may inhibit sphingosine-induced apoptosis by blocking a step upstream of cytochrome C release and caspase-3 activation.

Modified plication of the tunica albuginea in treating congenital penile curvature

OBJECTIVE

To describe a modified plication technique and compare the results with the Nesbit procedure for treating congenital penile curvature.

PATIENTS AND METHODS

Eleven men with congenital penile curvature were treated by a modified tunica albuginea plication technique. An artificial erection was induced by normal saline injection; in the areas where plication was planned, Buck's fascia was opened longitudinally and dissected a short distance toward the midline to free the neurovascular bundles. Allis clamps were used to grasp the tunica albuginea and "bumps" created. Two interrupted U-shaped sutures using 2/0 polyglactin were placed underneath each Allis clamp to secure the bump. The results were analysed retrospectively and compared with the results of 11 other men treated using the Nesbit procedure.

RESULTS

The mean (range) follow-up was 25 (12-47) months for the Nesbit procedure and 15 (8-26) months for the modified plication procedure. In the Nesbit group, eight patients had satisfactory cosmetic and functional results; three complained of penile shortening and one had erectile dysfunction. In the modified plication group, 10 patients reported satisfactory cosmetic and functional results; one complained of penile shortening, two were concerned about the indurations of the penis but none had erectile dysfunction.

CONCLUSIONS

The modified plication technique is easier to perform, is more often successful and causes fewer surgical complications than the Nesbit procedure for treating congenital penile curvature.

Syntheses, structures, and physicochemical properties of diruthenium compounds of tetrachlorocatecholate with metal-metal bonded Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+) cores (R = CH(3) and C(2)H(5))

Metal-metal bonded Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+) (R = CH(3) and CH(3)CH(2)) compounds with tetrachlorocatecholate (Cl(4)Cat) have been synthesized in the corresponding alcohol, MeOH and EtOH, from a nonbridged Ru(2+)-Ru(3+) compound, Na(3)[Ru(2)(Cl(4)Cat)(4)(THF)].3H(2)O.7THF (1). In alcohol solvents, compound 1 is continuously oxidized by oxygen to form Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+) species. The presence of a characteristic countercation leads to selective isolation of either Ru(3+)(mu-OR)(2)Ru(3+) or Ru(3.5+)(mu-OR)(2)Ru(3.5+) as a stable adduct species. In methanol, Ph(4)PCl and dibenzo-18-crown-6-ether afford Ru(3+)(mu-OMe)(2)Ru(3+) species, [A](2)[Ru(2)(Cl(4)Cat)(4)(mu-OMe)(2)Na(2)(MeOH)(6)] ([A](+) = Ph(4)P(+) (2), [Na(dibenzo-18-crown-6)(H(2)O)(MeOH)](+) (3)), while benzo-15-crown-5-ether provides a Ru(3.5+)(mu-OMe)(2)Ru(3.5+) species, [Na(benzo-15-crown-5)(2)][Ru(2)(Cl(4)Cat)(4)(mu-OMe)(2)Na(2)(MeOH)(6)] (4). The air oxidation of 1 in a MeOH/EtOH mixed solvent (1:1 v/v) containing benzo-15-crown-5-ether provides a Ru(3.5+)(mu-OMe)(2)Ru(3.5+) species, [Na(benzo-15-crown-5)(H(2)O)][Ru(2)(Cl(4)Cat)(2)(mu-OMe)(2)Na(2)(EtOH)(2)(H(2)O)(2)(MeOH)(2)].(benzo-15-crown-5) (5). Similarly, the oxidation of 1 in ethanol with Ph(4)PCl provides a Ru(3.5+)(mu-OEt)(2)Ru(3.5+) species, (Ph(4)P)[Ru(2)(Cl(4)Cat)(4)(mu-OEt)(2)Na(2)(EtOH)(6)] (7). A selective formation of a Ru(3+)(mu-OEt)(2)Ru(3+) species, (Ph(4)P)(2)[Ru(2)(Cl(4)Cat)(4)(mu-OEt)(2)Na(2)(EtOH)(2)(H(2)O)(2)] (6), is found in the presence of pyrazine or 2,5-dimethylpyrazine. The crystal structures of these compounds, except 2 and 7, have been determined by X-ray crystallography, and all compounds have been characterized by several spectroscopic and magnetic investigations. The longer Ru-Ru bonds are found in the Ru(3+)(mu-OR)(2)Ru(3+) species (2.606(1) and 2.628(2) A for 3 and 6, respectively) compared with those of Ru(3.5+)(mu-OMe)(2)Ru(3.5+) species (2.5260(6) A and 2.514(2) A for 4 and 5, respectively). These structural features and magnetic and ESR data revealed the electronic configurations of sigma(2)pi(2)delta(2)delta(2)pi(2) and sigma(2)pi(2)delta(2)delta(2)pi(1) for Ru(3+)(mu-OR)(2)Ru(3+) and Ru(3.5+)(mu-OR)(2)Ru(3.5+), respectively, in which the former is diamagnetic and the latter is paramagnetic with S = (1)/(2) ground state. Compound 5 forms a one-dimensional chain with alternating arrangement of a Ru(3.5+)(mu-OMe)(2)Ru(3.5+) unit and a free benzo-15-crown-5-ether molecule by intermolecular hydrogen bonds (O(H(2)O).O(crown-ether) = 2.91-3.04 A). The cyclic voltammetry in DMF affords characteristic metal-origin voltammograms; two reversible and two quasi-reversible redox waves were observed. The feature of cyclic voltammograms for the Ru(3+)(mu-OR)(2)Ru(3+) species (2, 3, and 6) and the Ru(3.5+)(mu-OR)(2)Ru(3.5+) species (4 and 7) are similar to each other, indicating that both species are electrochemically stable. The isolation of the pyrazine-trans-coordinated species, [Ph(4)P][Ru(Cl(4)Cat)(2)(L)(2)] (L = pyrazine (8), 2,5-dimethylpyrazine (9)), revealed the selective isolation of 6 from pyrazine-containing solution. UV-vis spectral variation by ethanolysis for 9 demonstrated the selective conversion from the pyrazine-trans-coordinated species to the Ru(3+)(mu-OEt)(2)Ru(3+) species without an oxidation to the Ru(3.5+)(mu-OEt)(2)Ru(3.5+) species. This result suggests the presence of equilibrium between [Ru(Cl(4)Cat)(2)(L)(2)](-) and Ru(3+)(mu-OEt)(2)Ru(3+) species in the synthetic condition for 6.

Risk factors associated with hepatitis C virus infection in Taiwanese government employees

This study evaluated the roles of multiple factors in hepatitis C virus (HCV) infection, with emphasis on the modification of various individual characteristics on the risk associated with percutaneous exposure to blood. Serum samples taken from 4869 men in Taiwan within a cohort study were tested for HCV antibody. The overall positive rate of anti-HCV was 1.6%. In a logistic regression, factors positively associated with anti-HCV positivity were previous blood transfusion (odds ratio [OR] = 7.28: 95% confidence interval [CI] = 4.26-12.45), a history of surgery (OR = 2.06: 95% CI = 1 23-3.46), and lower educational levels (OR = 1.94; 95% CI = 1.14-3.32). The anti-HCV positive rate was significantly lower in hepatitis B surface antigen (HBsAg) carriers than in non-carriers (OR = 0.60; 95% CI = 0.37-0.95). Ageing, lower educational levels, O blood group, and Taiwanese ethnicity enhanced the likelihood of HCV infection through blood transfusion/surgery, whereasHBsAg status, cigarette smoking, and habitual alcohol drinking reduced it.

Rubber foreign bodies in puncture wounds of the foot in patients wearing rubber-soled shoes

We report 8 cases of puncture wound of the foot associated with rubber foreign bodies in patients who were wearing rubber-soled shoes. The difficulty in making the correct diagnosis and the complications arising from these injuries are reviewed. The morbidity associated with these seemingly innocuous puncture wounds can be serious. Infective complications resolved only with removal of all imbedded rubber foreign bodies. A history of wearing rubber-soled shoes during the injury and a high index of suspicion may prevent complications.

Iodide oxidation and iodine reduction mediated by horseradish peroxidase in the presence of ethylenediaminetetraacetic acid (EDTA): the superoxide effect

Ethylenediaminetetraacetic acid (EDTA) is an inhibitor of iodide (I-) oxidation that is catalyzed by horseradish peroxidase (HRP). HRP-mediated iodine (I2) reduction and triiodide (I3+) disappearance occur in the presence of this inhibitor. It is interesting that in the presence of EDTA, HRP produces superoxide radical, a reactive oxygen species that is required for iodine reduction. Substitution of potassium superoxide (KO2) or a biochemical superoxide generating system (xanthine/xanthine oxidase) for HRP and H2O2 in the reaction mixture also can reduce iodine to iodide. Thus, iodine reduction mediated by HRP occurs because HRP is able to mediate the formation of superoxide in the presence of EDTA and H2O2. Although superoxide is able to mediate iodine reduction directly, other competing reactions appear to be more important. For example, high concentrations (mM range) of EDTA are required for efficient iodine reduction in this system. Under such conditions, the concentration (microM range) of contaminating EDTA-Fe(III) becomes catalytically important. In the presence of superoxide, EDTA-Fe(III) is reduced to EDTA-Fe(II), which is able to reduce iodine and form triiodide rapidly. Also of importance is the fact that EDTA-Fe(II) reacts with hydrogen peroxide to form hydroxyl radical. Hydroxyl radical involvement is supported by the fact that a wide variety of hydroxyl radical (OH) scavengers can inhibit HRP dependent iodine reduction in the presence of EDTA and hydrogen peroxide.

Assays for angiotensin converting enzyme inhibitory activity

A colorimetric method and a capillary electrophoresis procedure were developed for quantifying histidyl-leucine and hippurate, respectively. The colorimetric method is sensitive (extinction coefficient = 7.5 mM(-1) cm(-1)) and reproducible (CV = 1.7%, n = 5), which is based on a selective chromogenic reaction for histidyl-leucine (lambda(max) = 390 nm) using o-phthalaldehyde. For samples containing unusually high levels of histidine and/or histidyl peptides, the separation-based approach is preferable. The capillary electrophoresis method makes use of an in-capillary microextraction technique; complicated samples can be measured in less than 4 min without pretreatment. Protocols using both methods to measure angiotensin converting enzyme inhibitory activity were proposed.

Evaluation of Etest for direct antifungal susceptibility testing of yeasts in positive blood cultures

The performance of the Etest (AB BIODISK, Solna, Sweden) for direct antifungal susceptibility testing of yeasts in positive blood cultures was compared with that of the macrodilution method for determining the MICs of five antifungal agents. Culture broths with blood from bottles positive for yeasts were inoculated directly onto plates for susceptibility testing with the Etest, and the MICs were read after 24 and 48 h of incubation. A total of 141 positive blood cultures (72 cultures of Candida albicans, 31 of Candida tropicalis, 14 of Candida glabrata, 11 of Candida parapsilosis, 3 of Candida krusei, and 3 of Cryptococcus neoformans, 4 miscellaneous yeast species, and 3 mixed cultures) were tested, and the rates of MIC agreement (+/-1 log(2) dilution) between the direct Etest (at 24 and 48 h, respectively) and macrodilution methods were as follows: amphotericin B, 81.8 and 93.5%; flucytosine, 84.8 and 87.7%; fluconazole, 89.4 and 85.5%; itraconazole, 69.7 and 63.8%; ketoconazole, 87.9 and 79.0%. By a large-sample t test, the difference in log(2) dilution between the direct Etest and the macrodilution method was found to be small (P < 0.05). The lone exceptions were ketoconazole at 48 h of incubation and itraconazole at both 24 and 48 h of incubation (P > 0.05). By Tukey's multiple comparisons, the difference between the direct Etest (48 h) and reference methods among different species was found to be less than 1 log(2) dilution. When the MICs were translated into interpretive susceptibility, the minor errors caused by the direct Etest (at 24 and 48 h, respectively) were as follows: flucytosine, 2.3 and 1.4%; fluconazole, 3.0 and 3.6%; itraconazole, 21.2 and 21.3%. Itraconazole also produced an additional 3.0 and 3.6% major errors as determined by the direct Etest at 24 and 48 h, respectively. It was concluded that, except for itraconazole, the Etest method was feasible for direct susceptibility testing of blood cultures positive for yeasts. The method is simple, and the results could be read between 24 and 48 h after direct inoculation, whenever the inhibition zones were discernible.

F-box protein Grr1 interacts with phosphorylated targets via the cationic surface of its leucine-rich repeat

The flexibility and specificity of ubiquitin-dependent proteolysis are mediated, in part, by the E3 ubiquitin ligases. One class of E3 enzymes, SKp1/cullin/F-box protein (SCF), derives its specificity from F-box proteins, a heterogeneous family of adapters for target protein recognition. Grr1, the F-box component of SCF(Grr1), mediates the interaction with phosphorylated forms of the G(1) cyclins Cln1 and Cln2. We show that binding of Cln2 by SCF(Grr1) was dependent upon its leucine-rich repeat (LRR) domain and its carboxy terminus. Our structural model for the Grr1 LRR predicted a high density of positive charge on the concave surface of the characteristic horseshoe structure. We hypothesized that specific basic residues on the predicted concave surface are important for recognition of phosphorylated Cln2. We show that point mutations that converted the basic residues on the concave surface but not those on the convex surface to neutral or acidic residues interfered with the capacity of Grr1 to bind to Cln2. The same mutations resulted in the stabilization of Cln2 and Gic2 and also in a spectrum of phenotypes characteristic of inactivation of GRR1, including hyperpolarization and enhancement of pseudohyphal growth. It was surprising that the same residues were not important for the role of Grr1 in nutrient-regulated transcription of HXT1 or AGP1. We concluded that the cationic nature of the concave surface of the Grr1 LRR is critical for the recognition of phosphorylated targets of SCF(Grr1) but that other properties of Grr1 are required for its other functions.

Identification and characterization of androgen receptor associated coregulators in prostate cancer cells

The androgen receptor (AR) is a member of the nuclear receptor (NR) superfamily that mediates the effects of androgens on target tissues. Over the last decade, it has become apparent that NRs require accessory factors for optimal activation of target gene expression. Numerous NR coregulators have been identified, with diverse structures and potential mechanisms of coregulation, creating an increasingly complicated picture of NR action. Due to the expanding complexity of the coregulator field, this review will focus on the AR ligand-binding domain (LBD) and N-terminal interacting proteins identified by our lab. The LBD-interacting proteins ARA70, ARA55 and ARA54 were first characterized and ARA70 was found to have a relatively higher specificity for the AR in human prostate cancer DU145 cells. Characterization of the functional relationship between the AR and these coregulators indicated that ARA70 and ARA55 could enhance the androgenic effects of 17beta-estradiol (E2) and hydroxyflutamide (HF), an antiandrogen commonly used in the treatment of prostate cancer. ARA160, an AR N-terminal interacting protein also known as TATA element modulatory factor (TMF), was subsequently shown to cooperate with ARA70 in enhancing AR activity. Another AR N-terminal interacting protein, ARA24, interacted with the poly-Q tract, a region within the N-terminus of the AR linked to Kennedy's disease (X-linked spinal and bulbar muscular atrophy). More recently, our lab has identified ARA267, a SET domain containing protein, and supervillin, an F-actin binding protein, as AR coregulators. Collectively, the data from these studies indicate that these coregulators are necessary for optimal AR transactivation. Interruption of the interaction between AR and these proteins may serve as a new therapeutic target in the treatment of prostate cancer.

Placental transfer of the soy isoflavone genistein following dietary and gavage administration to Sprague Dawley rats

Genistein, the principal soy isoflavone, has estrogenic activity and is widely consumed by humans for putative beneficial health effects. The goal of the present study was to measure placental transfer of genistein in rats as a possible route of developmental exposure. Pregnant Sprague-Dawley rats were administered genistein orally, either by diet or by gavage. Concentrations of genistein aglycone and conjugates were measured in maternal and offspring serum and brain using HPLC with isotope dilution electrospray tandem mass spectrometry. Although fetal or neonatal serum concentrations of total genistein were approximately 20-fold lower than maternal serum concentrations, the biologically active genistein aglycone concentration was only 5-fold lower. Fetal brain contained predominately genistein aglycone at levels similar to those in the maternal brain. These studies show that genistein aglycone crosses the rat placenta and can reach fetal brain from maternal serum genistein levels that are relevant to those observed in humans.

Development of a latex agglutination test for rapid identification of Escherichia coli

Escherichia coli, one of the most important human pathogens, is usually identified by a battery of biochemical tests that require overnight incubation. For rapid identification of Escherichia coli, a latex agglutination test (LAT) was developed. Rabbits were immunized with cell-surface antigens extracted from Escherichia coli CCRC 15481 with 4 M urea, and the affinity-purified antibodies were used to coat latex particles for the identification of the bacterium. The following gram-negative bacteria were used to evaluate the LAT: Escherichia coli (n = 761), Enterobacteriaceae other than Escherichia coli (n = 632), Aeromonas spp. (n = 21), Pseudomonas spp. (n = 75), Vibrio spp. (n = 18), and other bacteria (n = 64). The LAT had a sensitivity and specificity of 99.2 and 93.3%, respectively. If the LAT was used in conjunction with the tests of indole production or lactose fermentation, the specificity values for the identification of Escherichia coli increased from 93.3 to 98.8 and 98.7%, respectively. If the LAT, indole production, and lactose fermentation were used together for the identification of Escherichia coli, the sensitivity and specificity were 94 and 99.7%, respectively. Lactose fermentation could be detected by observing the colonies grown on selective media (e.g. MacConkey agar), and indole production could be analyzed simply by the spot indole test. Strains producing negative reactions (i.e. not identified as Escherichia coli) should be processed by the conventional procedures for identification. The present protocol integrating the LAT, indole production, and lactose fermentation for the identification of Escherichia coli offers considerable savings of time, manpower, and cost.

Circular Hydraulic Jumps Triggered by Boundary Layer Separation

When a high-flow-rate circular jet impinges vertically on a horizontal plane, it flows out radially and then undergoes a distinctive hydraulic jump on the plane because of boundary layer separation induced by hydrostatic back pressure. The jump radius is shown to be 0.37 a Re(1/3) Lambda(-1/8), where Lambda=(ga(3)/nu(2)) Re(-7/3) is a modified Froude number, Re=(Q/anu) is the jet Reynolds number, a is the jet radius, and Q the liquid flow rate, which is favorably compared to experimental data in the limit of small Lambda. When Lambda exceeds 3.0x10(-4) at low flow rates, the jump radius decreases below a minimum in the film depth and our experiments detect a different jump mechanism that may be triggered by capillary pressure rather than hydrostatic pressure. Copyright 2001 Academic Press.

New molecular assemblies of redox isomers, [CrIII(X4SQ)3-n(X4Cat)n]-n (X = Cl and Br; n = 0, 1, and 2), with metallocenium cations, [MIIICp2]+ (M = Co and Fe): X-ray crystal structures and physical properties

A series of redox isomers of [CrIII(X4SQ)(X4Cat)2]2-, [CrIII(X4SQ)2(X4Cat)]-, and [CrIII(X4SQ)3]0 (X = Cl and Br, SQ = semiquinonate, and Cat = catecholate) have been synthesized and characterized as charge-transfer (CT) compounds with metallocenium cations: (CoIIICp2)2[CrIII(Cl4SQ)(Cl4Cat)2] (1), (CoIIICp2)2[CrIII(Br4SQ)(Br4Cat)2] (2), (FeIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)].C6H6 (4), (FeIIICp2)[CrIII(Br4SQ)2(Br4Cat)].CS2 (5), and (FeIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)][CrIII(Cl4SQ)3] (6). First, the oxidation states of the chromium complexes are strongly dependent on the redox potentials of the metallocenes used. The CoIICp2, exhibiting stronger reduction power than FeIICp2, is useful for two-electron reduction of the [CrIII(X4SQ)3]0, affording [CrIII(X4SQ)(X4Cat)2]2- (1 and 2), which are first isolated and crystallographically characterized in the solid state. In contrast the reaction with FeIICp2 affords only [CrIII(X4SQ)2(X4Cat)]- (4 and 5). Second, solvents influence crystal structures of these compounds. The solvent set of C6H6/CS2 gives 1:1:C6H6 compound 4 with unique charged anions, [CrIII(Cl4SQ)2(Cl4Cat)]-, while the other set, n-C6H12/CS2, affords 1:2 compound 6 including the two redox isomers, [CrIII(Cl4SQ)2(Cl4Cat)]- and [CrIII(Cl4SQ)3]0. The [CrIII(X4SQ)(X4Cat)2]2- anions in 1 and 2 show no significant interconnection between them (discrete type), while the [CrIII(X4SQ)2(X4Cat)]- anions in 4-6 show one-dimensional column-type structures with the aid of intermolecular stacking interactions of the ligand moieties. The anions in 4 show additional stacking interaction with the [FeIIICp2]+ to form one-dimensional ...[D][A][S][D][A]... (D = [FeIIICp2]+, A = [CrIII(Cl4SQ)2(Cl4Cat)]-, and S = C6H6) type mixed-stack arrangements similar to that of previously reported (CoIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)].C6H6 (3). Compound 6 forms a two-dimensional sheet structure where the two redox isomers, [CrIII(Cl4SQ)2(Cl4Cat)]- and [CrIII(Cl4SQ)3]0, are included. The sheet is regarded as a mixed-valence molecular assembly. Two types of the anions, [CrIII(X4SQ)(X4Cat)2]2- (1 and 2) and [CrIII(X4SQ)2(X4Cat)]- (4-6), exhibiting an intramolecular mixed-valence state, show intramolecular intervalence CT transition (IVCT) from the Cat to the SQ at near 5800 and 4300 cm-1, respectively, both in the solution and in the solid states. The intermolecular mixed-valence state of 6 was characterized by absorption spectroscopy, electric conductivity, and SQUID magnetometry. Interestingly, this mixed-valence state of the chromium module is dependent on the redox active nature of the coordinated ligands.

Expression and detection of ScFvB9 and its mutant in recombinant phage antibody system

Recombinant single-chain antibody (ScFvB9) and its mutant (ScFvB9-6) were generated by using a polymerase chain reaction (PCR) from the Fab fragment of the murine monoclonal antibody (MAb) B9, MabB9 (gamma2b,kappa), which is specific for human plasma apolipoprotein (apo) B-100 of low density lipopreotein (LDL). In the recombinant phage antibody system (RPAS), the constructed ScFvB9 and ScFvB9-6 antibody genes were cloned into the pCANTAB5E phagemid vector and expressed in E. coli. The active forms of single-chain antibodies (ScFvB9 and ScFvB9-6) were produced as phage-displayed recombinant antibodies or soluble antibody forms in E. coli. The activities of ScFvB9 and ScFvB9-6 were confirmed by enzyme-linked immunosorbent assay (ELISA) and Western blotting analysis; the generated mutant ScFvB9-6 showed slightly higher antigen binding activity than native ScFvB9 as a soluble antibody in this RPAS.

Inhibition of lignin peroxidase-mediated oxidation activity by ethylenediamine tetraacetic acid and N-N-N'-N'-tetramethylenediamine

The mineralization rate of LC-[1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane] (DDT) was reduced by 90% on the 18th day in fungal cultures of Phanerochaete chrysosporium in the presence of 8 mM ethylenediamine tetraacetic acid (EDTA). In the presence of 8 mM N-N-N'-N'-tetramethylenediamine (TEMED), the mineralization rate of 14C-DDT was reduced by 80%. In the presence of 2 mM or 10 mM EDTA, 95% inhibition of lignin peroxidase (LiP) mediated veratryl alcohol oxidase activity and 97% inhibition of LiP mediated iodide oxidase activity occurred. TEMED caused 79% inhibition of veratryl alcohol oxidase activity and 92% inhibition of iodide oxidase activity when the amount used was 2 mM and 10 mM, respectively. In the presence of Zn(II) with slight molar excess of the EDTA concentration, reversed the EDTA mediated non-competitive inhibition of LiP catalyzed veratryl alcohol or iodide oxidation, Zn(II) also reversed the inhibition of LiP catalyzed veratryl alcohol oxidase activity caused by chelators other than EDTA and TEMED. In addition to Zn(II), several other metal ions also relieved EDTA mediated inhibition of veratryl alcohol and iodide oxidase activity catalyzed by LiP. The ability of veratryl alcohol to inhibit iodide oxidation catalyzed by LiP showed that veratryl alcohol could inhibit LiP mediated iodide oxidase activity. Increasing the concentration of iodide was also shown to inhibit veratryl alcohol oxidation. Kinetic analysis showed that the reaction was competitive inhibition.

Androgen-receptor gene CAG repeats, plasma testosterone levels, and risk of hepatitis B-related hepatocellular carcinoma

BACKGROUND

Worldwide, hepatocellular carcinoma (HCC) is more prevalent in men than in women, suggesting that sex hormones and/or X-chromosome-linked genes may be involved in hepatocarcinogenesis. We investigated the association of a trinucleotide (CAG) repeat in the androgen receptor (AR) gene (located on the X chromosome) termed "AR-CAG repeats," levels of plasma testosterone, and the risk of HCC in Taiwanese men. Chronic hepatitis B virus (HBV) infection, which is associated with risk of HCC, is hyperendemic in Taiwan.

METHODS

We compared the number of AR-CAG repeats in 285 HBV carriers with HCC and in 349 HBV carriers without HCC. We also conducted a nested case--control study on participants in a cohort study. Blood was collected prospectively from 110 case patients and 239 control subjects and was used to determine the number of AR-CAG repeats and plasma testosterone level. All statistical tests were two-sided.

RESULTS

The overall odds ratio (OR) for HCC was 1.72 (95% confidence interval [CI] = 1.03--2.89) for HBV carriers with 20 or fewer AR-CAG repeats compared with those with more than 24 repeats. This association was observed only in patients with late-onset HCC (OR = 2.37; 95% CI = 1.28--4.38). In the nested case-control study, HBV carriers in the highest tertile of testosterone levels had a statistically significantly increased risk of HCC (OR = 2.06; 95% CI = 1.14--3.70) compared with those in the lowest tertile. Elevated testosterone was more strongly associated with early-onset (OR = 4.67; 95% CI = 1.41--15.38) than late-onset disease. HBV carriers with 20 or fewer AR-CAG repeats and higher testosterone levels had a fourfold increase in HCC risk compared with those with more than 24 repeats and testosterone levels in the lowest tertile.

CONCLUSIONS

Higher levels of androgen signaling, reflected by higher testosterone levels and 20 or fewer AR-CAG repeats, may be associated with an increased risk of HBV-related HCC in men.

Study of propofol in bovine aortic endothelium: I. Inhibitory effect on bradykinin-induced intracellular calcium immobilization

BACKGROUND

Propofol has been found to affect the intracellular calcium concentration with clinical manifestations of hypotension and bradycardia. The purpose of this study is to examine the effect of propofol on intracellular calcium immobilization in bovine aortic endothelium under the stimulation of bradykinin.

METHODS

In order to validate the effect of propofol on the alteration of intracellular calcium concentration, we used the cultured bovine endothelial cells (Gm 7372a) to measure the calcium immobilization within the cells preincubated with or without propofol of clinical concentration. Using Fluo-3 staining and a fluorescence spectrophotometer (confocal microscope), intracellular calcium immobilization was demonstrated by the appearance of "hot spots" within the cytoplasm and perinuclear regions after addition of bradykinin to the cells. The changes of fluorescence density measured within these areas versus the effect of time were analyzed and compared with the cells in control group.

RESULTS

After addition of bradykinin, intracellular calcium hot spots increased dramatically within seconds and reached a maximal level within 20 seconds. The concentrations of calcium gradually decreased to a constant level after about 3 min following the addition of bradykinin to the cells. With pretreatment of propofol at 0.01 mM and 37 degrees C for 30 min, the immobilization of intracellular calcium from the intracellular stores were significantly inhibited that was demonstrated by the decreased appearance of hot spots when compared with control.

CONCLUSIONS

Our data demonstrated that under the stimulation of bradykinin, propofol at 0.01 mM, could inhibit intracellular calcium release from the intracellular stores in bovine aortic endothelial cells. This phenomenon might explain the possible mechanism for the clinical manifestations of hypotension and/or bradycardia associated with propofol.

Induction of p27(KIP1) as a mechanism underlying NS398-induced growth inhibition in human lung cancer cells

Increased expression of cyclooxygenase-2 (COX-2) causes enhanced production of prostaglandins, which are emerging as important mediators of growth stimulation of cancer cells. Overexpression of COX-2 has been found in human non-small cell lung cancer tissues and cell lines. In vitro and in vivo studies showed that nonselective cyclooxygenase inhibitors (like aspirin and indomethacin) may suppress growth of lung cancer cells and may prevent lung tumorigenesis induced by the tobacco-specific carcinogens. However, the molecular mechanisms that mediated the anticancer action of these inhibitors are not well defined. In this study, we examined the effect of a specific COX-2 inhibitor, N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide (NS398), on high COX-2-expressing A549 lung cancer cells. Our results indicated that NS398 inhibited prostaglandin E(2) synthesis and induced G(1) growth arrest in these cells. NS398 specifically up-regulated cyclin-dependent kinase inhibitor p27(KIP1), whereas the expressions of G(1)-acting cyclins and cyclin-dependent kinases were not changed. Additionally, NS398 effectively suppressed cyclin E-associated kinase activity in A549 cells. The molecular mechanism responsible for the induction of p27(KIP1) by NS398 was characterized. We found that NS398 did not induce p27(KIP1) through transcriptional activation because this drug could not stimulate the p27(KIP1) promoter. Metabolic labeling experiments showed that the synthesis rate of p27(KIP1) protein was not altered by NS398. Conversely, pulse-chase assays demonstrated that degradation of p27(KIP1) protein was obviously reduced in NS398-treated cells. We conclude that NS398 enhances p27(KIP1) expression via post-translational regulation, and our results provide a new mechanism by which specific COX-2 inhibitors suppress proliferation of cancer cells.

Functional analysis of androgen receptor N-terminal and ligand binding domain interacting coregulators in prostate cancer

Several new androgen receptor (AR) coregulators, including ARA70, ARA55, ARA54, ARA160 and ARA24, associated with the N-terminal or the ligand-binding domain (LBD) of AR, have been identified by our group. We first identified the AR-LBD coregulators ARA70, ARA55, and ARA54. Our previous reports suggest that ARA70 can enhance the androgenic activity of 17 beta-estradiol (E2) and antiandrogens toward AR. It is of interest to compare and determine if the specificity of sex hormones and antiandrogens can be modulated by different coregulators. Our results indicate that, ARA70 is the best coregulator for increasing the androgenic activity of E2. Only ARA70 and ARA55 were able to significantly increase the androgenic activity of hydroxyflutamide, the active metabolite of a widely-used antiandrogen for the treatment of prostate cancer. Furthermore, our results suggest that among the LBD coregulators, ARA70 has a relatively high specificity for AR in the human prostate cancer cell line DU145. Together, our data suggest that the androgenic activity of some sex hormones and antiandrogens can be modulated by selective AR coactivators. In addition to the AR-LBD associated proteins, ARA24 and ARA160 have been identified as AR coregulators, interacting with the AR N-terminal instead of the LBD. Functional analysis revealed that the AR N-terminal coregulator ARA160 could cooperate with the AR LBD-associated coregulator ARA70. Our data indicate that ARA24 could also interact with AR, and that this binding is decreased by an expanding poly-glutamine (Q) length within AR. The length of the poly-Q stretch in the AR N-terminal domain is inversely correlated with the transcriptional activity of AR. Our data suggest that optimal AR transactivation may require interaction of AR with AR coregulators. The identification of factors or peptides that can interrupt androgen-mediated AR-ARA interactions may be useful in the development of better antiandrogens for treating androgen-related diseases, such as prostate cancer.

Dietary genistein inactivates rat thyroid peroxidase in vivo without an apparent hypothyroid effect

Biological effects of genistein are currently under investigation by the National Toxicology Program because of widespread and increasing soy consumption by humans and evidence for modulation of endocrine function. Rats were exposed to genistein aglycone in soy-free feed fortified at 0, 5, 100, and 500 ppm starting in utero through 20 weeks. Thyroid glands and serum were analyzed for total genistein (aglycone + conjugates) using HPLC with electrospray mass spectrometric detection. Microsomal thyroid peroxidase (TPO) activity was measured spectrophotometrically. The total genistein content in rat serum was as high as 8 microM, and significant dose-dependent increases of genistein in thyroid tissue up to 1 pmol/mg were found in male and female rats. The activity of TPO in male and female rats was found to be reduced by up to 80% in a dose-dependent manner. Male and female rats consuming a standard soy-based rodent diet (NIH 31) had TPO activity approximately 50% lower than rats consuming a soy-free diet and this loss was commensurate with measured serum levels of isoflavones. Suicide inactivation of rat, porcine, and human TPO was observed in vitro at concentrations of genistein aglycone comparable to those measured in rat thyroids. Thyroid hormone levels (T3, T4, TSH) in serum, thyroid weights, and histopathology showed no differences between treated and untreated groups. These findings suggest that, even though substantial amounts of TPO activity are lost concomitant to soy isoflavone consumption by normal rats, the remaining enzymatic activity is sufficient to maintain thyroid homeostasis in the absence of additional perturbations.

Role of N-acetyltransferase polymorphisms in hepatitis B related hepatocellular carcinoma: impact of smoking on risk

BACKGROUND

Persistent infection with hepatitis B virus (HBV) causes chronic phasic necroinflammation and regenerative proliferation in the liver. The sustained hepatocellular proliferation may render chronic HBV carriers more susceptible to the effects of environmental carcinogens. Aromatic amines are potential hepatocarcinogens in humans. N-acetyltransferase (NAT) is involved in the metabolic activation and detoxification of these compounds.

AIMS

To investigate if genetic polymorphisms in N-acetylation are related to hepatocellular carcinoma (HCC) among chronic HBV carriers.

METHODS

Genotyping of NAT1 and NAT2 was performed using polymerase chain reaction-restriction fragment length polymorphism on peripheral leucocyte DNA from 151 incident cases of HCC and 211 controls. All subjects were male, and were chronic HBV surface antigen carriers.

RESULTS

A significant association between NAT2 genetic polymorphism and HCC was observed among chronic HBV carriers who were smokers but not among those who were non-smokers. For smoking HBV carriers, the odds ratios of developing HCC for those heterozygous and homozygous for the NAT2*4 functional allele compared with those without any copies of the functional allele (reference group) were 2.67 (95% confidence interval 1.15-6.22) and 2.58 (95% confidence interval 1.04-6.43), respectively. The interaction between cigarette smoking and the presence of the NAT2*4 allele just failed to reach statistical significance (p=0.06). No association between NAT1 genotype and HCC was evident overall or within the smoking stratified subgroups.

CONCLUSIONS

Our results suggest that NAT2 activity may be particularly critical in smoking related hepatocarcinogenesis among chronic HBV carriers. Our data also indirectly support a role for tobacco smoke derived aromatic amines in the aetiology of HCC.

Modulation of cell cycle regulatory protein expression and suppression of tumor growth by mimosine in nude mice

Our previous results demonstrated that the plant amino acid mimosine blocked cell cycle progression and suppressed proliferation of human lung cancer cells in vitro by multiple mechanisms. Inhibition of cyclin D1 expression or induction of cyclin-dependent kinase inhibitor p21WAF1 expression was found in mimosine-treated lung cancer cells. However, whether mimosine may modulate the expression of these cell cycle regulatory proteins and suppress tumor growth in vivo is unknown. In this study, we examined the anti-cancer effect of mimosine on human H226 lung cancer cells grown in nude mice. Our results demonstrated that mimosine inhibits cyclin D1 and induces p21WAF1 expression in vivo. Furthermore, results of TUNEL analysis indicated that mimosine may induce apoptosis to suppress tumor growth in nude mice. Collectively, these results suggest that mimosine exerts anti-cancer effect in vivo and might be useful in the therapy of lung cancer.

Mass spectrometric determination of Genistein tissue distribution in diet-exposed Sprague-Dawley rats

Genistein, the principal soy isoflavone, was administered in the diet to male and female Sprague-Dawley rats as part of a multigeneration study of potential endocrine modulation. The rats were exposed to genistein in utero, through maternal milk, and as adults through postnatal d 140 via essentially isoflavone-free feed (approximately 0.5 microg/g) fortified at 5, 100 and 500 microg/g with genistein aglycone. Analytical methods based on liquid chromatography, mass spectrometry and the use of deuterated genistein were developed and validated for use in measuring genistein in serum and tissues. Pharmacokinetic analysis of serum genistein showed a significant difference (P < 0.001) in the elimination half-life and area under the concentration-time curve between male [2.97 +/- 0.14 h and 22.3 +/- 1.2 micromol/(L. h), respectively] and female rats [4.26 +/- 0.29 h and 45.6 +/- 3.1 micromol/(L. h), respectively, +/- SEM]. Endocrine-responsive tissues including brain, liver, mammary, ovary, prostate, testis, thyroid and uterus showed significant dose-dependent increases in total genistein concentration. Female liver contained the highest amount of genistein (7.3 pmol/mg tissue) and male whole brain contained the least (0.04 pmol/mg). The physiologically active aglycone form was present in tissues at fractions up to 100%, and the concentration was always greater than that observed in serum in which conjugated forms predominated (95-99%). These results for measured amounts of genistein, present as aglycone and conjugates, in putative target tissues provide a link with other studies in which blood concentrations and physiologic effects of genistein are measured.