Long-term clinical outcomes of endoscopic submucosal dissection for colorectal neoplasia with or without the hybrid technique.

AIM: The main aim of this study was to compare the long-term outcome of a conventional colorectal endoscopic submucosal dissection (ESD) in which submucosal dissection was continued throughout until the completion of resection (ESD-T) to hybrid endoscopic submucosal dissection (ESD-H) in the colorectum. METHOD: Medical records of 836 colorectal neoplasia patients treated by ESD-T or ESD-H were reviewed. ESD-H was defined as colorectal ESD with additional snaring in the final stage of the procedure. Primary outcomes were the overall and metastatic recurrence rates. Secondary outcomes were short-term outcomes such as the en bloc resection rate, procedure time and adverse events. RESULTS: The overall recurrence rate was higher in the ESD-H than in the ESD-T group (5.7% vs 0.7%, P = 0.001). The metastatic recurrence rate showed no significant difference between these groups (1.4% vs 1.4%, P = 1.000). Multivariate analysis revealed that a failed en bloc resection (hazard ratio 24.097; 95% CI 5.446-106.237; P < 0.001) and larger tumour size (hazard ratio 1.042; 95% CI 1.014-1.070; P = 0.003) were independently associated with overall recurrence. The ESD-H group showed a lower en bloc resection rate (56.8% vs 96.5%, P < 0.001), shorter procedure time (45.6 vs 54.3 min, P < 0.001) and higher perforation rate (10.3% vs 6.0%, P = 0.029). CONCLUSION: Although long-term outcomes in terms of overall recurrence are inferior following ESD-H, a failed en bloc resection and large tumour size are the only independent risk factors for recurrence. Further investigations are warranted to improve the long-term outcomes of ESD-H.

GABAB receptor cell-surface export is controlled by an endoplasmic reticulum gatekeeper.

Endoplasmic reticulum (ER) release and cell-surface export of many G protein-coupled receptors (GPCRs) are tightly regulated. For gamma-aminobutyric acid (GABA)B receptors of GABA, the major mammalian inhibitory neurotransmitter, the ligand-binding GB1 subunit is maintained in the ER by unknown mechanisms in the absence of hetero-dimerization with the GB2 subunit. We report that GB1 retention is regulated by a specific gatekeeper, PRAF2. This ER resident transmembrane protein binds to GB1, preventing its progression in the biosynthetic pathway. GB1 release occurs upon competitive displacement from PRAF2 by GB2. PRAF2 concentration, relative to that of GB1 and GB2, tightly controls cell-surface receptor density and controls GABAB function in neurons. Experimental perturbation of PRAF2 levels in vivo caused marked hyperactivity disorders in mice. These data reveal an unanticipated major impact of specific ER gatekeepers on GPCR function and identify PRAF2 as a new molecular target with therapeutic potential for psychiatric and neurological diseases involving GABAB function.

[Study of the genes correlated with cyst calcification in patients with cystic echinococcosis].

OBJECTIVE: To explore the genes (biomarkers) correlated with cyst calcification in patients with cystic echinococcosis (CE), and to provide the evidence for the judgment on the patients' prognosis at molecular level. METHODS: The liver tissues from 32 patients with liver CE (10 cases for mRNA microarray and 22 cases for real-time PCR analysis) and 11 patients with hepatic cystadenoma were collected from three hospitals in Ningxia from June, 2013 to December, 2014. A comparison of the different gene-expressions between five patients with calcified lesions and five cases with no calcification was carried out using Significant Analysis of Microarrays (SAM) to select a subset of differentially expressed genes (DEGs) . Fold-change analysis was used to assess the changes of the expression quantity in the same genes between two groups. The verification was conducted among the liver tissues from 22 patients with liver CE (11 in the group of calcified or 11 in that of non-calcified) by real-time quantitative PCR (RT-qPCR). With GAPDH as a reference-gene and the liver tissues from 11 cases with hepatic cystadenoma as standardized control groups, the relative expressions of galecitin-4 (LGALS4) and acid ceramidase (ASAH1) in patients with calcified and non-calcified were calculated, respectively. The differences between two groups were compared using t'-test. RESULTS: Five screened genes presented siginificantly different expressions all had showed the low-regulated expressions in the calcified group, with the most distinct low-regulation of LGALS4 and ASAH1 whose fold changes were 0.008 8, and 0.020 3, respectively. The verification by RT-qPCR illustrated that the relative expression of LGALS4 was showed at level of 0.49±0.27 amongst patients with calcified, and at level of 2.70±2.61 amongst non-calcified individuals,,indicating significant differences between two groups (t=-2.59, P=0.026); while the ASAH1 was relatively expressed at levels of 1.36±0.33 and of 1.68±0.67 amongst patients with calcified and non-calcified, respectively, showing insignificant changes statistically (t=-1.44, P=0.167). In the non-calcified group, both LGALS4 and ASAH1 genes expression quantities had a small fluctuation range, but with positively correlated trend (r=0.91, P=0.001), which indicated that a patient with the low LGALS4 expression quantity also had a relative low level of ASAH1 expression quantity. CONCLUSIONS: Low expression quantity of LGALS4 and ASAH1 genes in patients with CE in the calcification might be potential biomarker for an indication of the disease self-healing.

Incidence and clinical features of Clostridium difficile infection in Korea: a nationwide study.

The incidence and severity of Clostridium difficile infections (CDI) have increased in Western countries. However, there are limited data regarding the epidemiology of CDI in Eastern countries. This nationwide study was conducted in 17 hospitals to determine temporal trends in CDI incidence (from 2004 to 2008) in South Korea. The total incidence of CDI in Korea was 1·7 cases/1000 adult admissions in 2004, and 2·7/1000 cases in 2008 (P = 0·028). When analysing the clinical features of 1367 CDI patients diagnosed in 2008, oral metronidazole was effective as a first-line treatment for CDI (61·9%). Relapse rate was 8·9% and complicated CDI was only observed in 3·6%. The incidence of CDI increased significantly in Korea from 2004 to 2008. Although the clinical features were milder than in Western countries, the increasing burden of CDI needs ongoing surveillance systems.

Long term follow-up of appendiceal and distal right-sided colonic inflammation.

The aim of this study was to investigate the possibility of appendiceal orifice inflammation (AOI) as a preceding lesion in the development of ulcerative colitis. A total of 20 patients were identified (mean age 41.2 years; 11 males) who had ulcerative colitis-like inflammatory lesions at the appendiceal orifice without concomitant typical features of ulcerative colitis, such as rectal involvement. A total of 19 patients were followed up endoscopically for a mean duration of 18.4 months (range 2 - 84 months). Typical ulcerative colitis developed in five patients (25 %; four proctitis, one pancolitis) in a mean time of 18.4 months (range 2 - 36 months). Negative conversion of all inflammatory lesions occurred in seven patients (35 %) after a mean follow-up of 20 months (range 3 - 84 months). In the remaining seven patients (35 %), initial lesions did not progress to ulcerative colitis and did not go into remission during a mean follow-up of 16.9 months (range 2 - 42 months). These results suggest that, at least in some cases, AOI precedes development of ulcerative colitis.

Benzo[a]pyrene diol epoxides: mechanism of enzymatic formation and optically active intermediates.

Studies of the mechanism of benzo[a]pyrene metabolism to reactive diol epoxides and of their disposition indicate that the metabolic intermediates of the activation pathways, 7,8-epoxide and trans-7,8-diol, as well as the two stereoisomeric diol epoxides are all optically active. Benzo[a]pyrene is converted to optically active 9,10-epoxides of (-)trans-7,8-diol by three enzymatic steps: (i) stereospecific oxygenation at the 7,8 double bond of benzo[a]pyrene by the mixed-function oxidases to essentially a single enantiomer of 7,8-epoxide, (ii) hydration of the 7,8-epoxide by epoxide hydratase to an optically pure (-)trans-7,8-diol, and (iii) stereoselective oxygenation by the mixed-function oxidases at the 9,10 double bond of the (-) trans-7,8-diol to optically active r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene and optically active r-7,t-8-dihydroxy-c-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene in a ratio of approximately 10 to 1.

A high-resolution anorectal manometry parameter based on integrated pressurized volume: A study based on 204 male patients with constipation and 26 controls.

BACKGROUND: Conventional anorectal manometric parameters based on linear waves cannot properly predict balloon expulsion (BE) time. We aimed to determine the correlation between integrated pressurized volume (IPV) parameters during simulated evacuation (SE) and BE time in healthy individuals and constipated patients and to assess the correlation between each parameter and symptoms. METHODS: A total of 230 male participants (including 26 healthy volunteers and 204 chronically constipated patients) underwent high-resolution anorectal manometry (HRAM) and BE tests. The IPV was calculated by multiplying the amplitude, distance, and time from the HRAM profile. Receiver operating characteristic curve (ROC) analysis and partial least square regression (PLSR) were performed. KEY RESULTS: ROC analysis indicated that the IPV ratio between the upper 1 cm and lower 4 cm of the anal canal was more effective for predicting BE time (area under the curve [AUC]: 0.74, 95% confidence interval [CI]: 0.67-0.80, P < .01) than the conventional anorectal parameters, including defecation index and rectoanal gradient (AUC: 0.60, 95% CI: 0.52-0.67, P = .01). PLSR analysis of a linear combination of IPV parameters yielded an AUC of 0.79. Moreover, the IPV ratio showed a greater clinical correlation with patient symptoms than conventional parameters. CONCLUSIONS AND INFERENCES: The IPV parameters and the combination of IPV parameters via PLSR were more significantly correlated with BE time than the conventional parameters. Thus, this study presents a useful diagnostic tool for the evaluation of pathophysiologic abnormalities in dyssynergic defecation using IPV and BE time.

A distinct array of proinflammatory cytokines is expressed in human colon epithelial cells in response to bacterial invasion.

Pathogenic bacteria that penetrate the intestinal epithelial barrier stimulate an inflammatory response in the adjacent intestinal mucosa. The present studies asked whether colon epithelial cells can provide signals that are important for the initiation and amplification of an acute mucosal inflammatory response. Infection of monolayers of human colon epithelial cell lines (T84, HT29, Caco-2) with invasive strains of bacteria (Salmonella dublin, Shigella dysenteriae, Yersinia enterocolitica, Listeria monocytogenes, enteroinvasive Escherichia coli) resulted in the coordinate expression and upregulation of a specific array of four proinflammatory cytokines, IL-8, monocyte chemotactic protein-1, GM-CSF, and TNF alpha, as assessed by mRNA levels and cytokine secretion. Expression of the same cytokines was upregulated after TNF alpha or IL-1 stimulation of these cells. In contrast, cytokine gene expression was not altered after infection of colon epithelial cells with noninvasive bacteria or the noninvasive protozoan parasite, G. lamblia. Notably, none of the cell lines expressed mRNA for IL-2, IL-4, IL-5, IL-6, IL-12p40, IFN-gamma, or significant levels of IL-1 or IL-10 in response to the identical stimuli. The coordinate expression of IL-8, MCP-1, GM-CSF and TNF alpha appears to be a general property of human colon epithelial cells since an identical array of cytokines, as well as IL-6, also was expressed by freshly isolated human colon epithelial cells. Since the cytokines expressed in response to bacterial invasion or other proinflammatory agonists have a well documented role in chemotaxis and activation of inflammatory cells, colon epithelial cells appear to be programmed to provide a set of signals for the activation of the mucosal inflammatory response in the earliest phases after microbial invasion.

Micropapillary bladder cancer: a clinico-pathological characterization and treatment analysis.

PURPOSE: Micropapillary bladder cancer (MPBC) is a very rare and aggressive variant of urothelial carcinoma (UC). The aim of this study was to investigate the clinico-pathological characteristics, treatment, and prognosis of MPBC to improve the understanding of this invasive disease. METHODS: We reviewed the records of 6 patients with MPBC who were evaluated and treated at our hospital between 2009 and 2015, and additionally reviewed 38 cases reported in the literature. RESULTS: In 44 cases, 36 cases (81.8%) were male and 8 cases (18.2%) were female, with a male:female ratio of 4.5:1; the median age of the patients was 68 years (range 45-91 years). A majority (81.8%) of patients with cT1 above or with lymph node and distant metastasis (cT2N0 in 18.2%, cT3-4N0 in 13.6%, cTanyN+ in 43.2%, and cTanyM+ in 6.8%). There was a high grade in 70.5% of patients. Lymphovascular invasion (LVI) was present in 61.4% of patients, and LVI in cT2 was more common than in cT1 (71.4 vs 22.2%). 52.3% of patients were treated with radical cystectomy (RC). After a mean follow-up of 16.2 months, 77.3% of patients developed distant metastases, and 47.7% of patients died of the disease. The mean overall survival (OS) was 28.9 months and the median OS was 20 months, and the amount of micropapillary (MPP) is correlated inversely with prognosis. CONCLUSIONS: Micropapillary bladder cancer is a rare variant of UC associated with a poor prognosis, which often presents at an advanced stage with LVI and distant metastases. The optimal treatment strategy is early RC combined with chemotherapy.

Carbon monoxide and nitric oxide protect against tumor necrosis factor-alpha-induced apoptosis in osteoblasts: HO-1 is necessary to mediate the protection.

BACKGROUND: Carbon monoxide (CO) and nitric oxide (NO) each have unique roles for various inflammatory states, including inflammatory bone resorption. Although it is known that NO can induce the expression of the cytoprotective enzyme HO-1, there is no information as to whether the protective effect of CO requires NO production or whether CO must induce the expression of HO-1 to exert its functional effects. METHODS: Murine osteoblast cells, MC3T3E1 osteoblasts, were cultured for CO and NO-associated HO-1 experiments and were transfected with pcDNA 3, pcDNA 3-HO-1, control siRNA or HO-1 siRNA using Nucleofector. For cell death measurement, MTT and annexin V assays were used. We performed Western blotting to check the expressions of HO-1 and iNOs and measured the HO-1 enzyme activity. We also measured the amounts of nitrite and nitrate using Griess reagents. RESULTS: The increased expression of HO-1 is required for the protective effect of NO and a single treatment of CO can increase the expression of HO-1, and this is also important for the protective effect of CO in MC3T3E1 osteoblasts. CO as well as NO attenuates the TNF-alpha-induced apoptosis in osteoblasts. The anti-apoptotic effect of CO or NO is not mediated by cGMP, and CO has no effect on the release of NO. The inhibition of HO-1 with using the HO-1 inhibitor ZnPP or HO-1 siRNA resulted in a striking increase of apoptosis in the CO/TNF-alpha-treated cells. Furthermore, HO-1 overexpression showed resistance against the TNF-alpha-induced cytotoxicity in the MC3T3E1 osteoblasts. CONCLUSIONS: There is a need for HO-1 expression to mediate the protection provided by exogenous CO or NO in osteoblasts.

Metabolism of 7,8-dihydrobenzo(a)pyrene by rat liver microsomal enzymes and mutagenicity of metabolites.

7,8-Dihydrobenzo[a]pyrene (7,8-H2BaP) was metabolized by rat liver microsomes to form 7,8,9,10-tetrahydro-BaP trans-9,10-diol, 7,8,9,10-tetrahydro-BaP cis-9,10-diol, 7-hydroxy-7,8-H2BaP, 8-hydroxy-7,8-H2BaP, two phenolic products of 7,8-H2BaP [abbreviated as 7,8-H2BaP phenol 1 and phenol 2 according to their elution order on reversed-phase high-performance liquid chromatography (HPLC)], 4,5,7,8-tetrahydro-BaP trans-4,5-diol, BaP cis-7,8-dihydrodiol, BaP, and the metabolites known to be formed from the metabolism of BaP. Metabolites were isolated by reversed-phase and normal-phase HPLC and identified by ultraviolet-visible absorption and mass spectral analyses and by comparing their retention times with synthetic standards whenever available. The enantiomeric compositions of some mono-ol and diol metabolites were determined by chiral stationary phase HPLC. The optical purities of monool and diol metabolites formed were found to be dependent on the nature of cytochrome P-450 isozymes present in liver microsomes. Metabolites formed by liver microsomes from untreated, phenobarbital-treated, 3-methylcholanthrene-treated, and polychlorinated biphenyls (Aroclor 1254)-treated male Sprague-Dawley rats were quantified by using specifically tritium-labeled [10-3H]-7,8-H2BaP and liquid scintillation counting of fractions collected from reversed-phase HPLC. A portion (2-7% depending on the type of microsomes used) of the BaP found was formed nonenzymatically in microsomal metabolism of 7,8-H2BaP. The formations of other major metabolites were all cytochrome P-450 isozymes dependent since their formations were inhibited by carbon monoxide and were dependent on the presence of reduced nicotinamide adenine dinucleotide phosphate. Furthermore, the formations of tetrahydrodiols, monools, and phenols were not inhibited by the epoxide hydrolase inhibitor, 3,3,3-trichloropropylene 1,2-oxide. The relative mutagenic activities toward Salmonella typhimurium TA98 at 2 nmol of chemical per plate and 10 microliters of liver S9 fraction were: (+/-)BaP trans-7,8-dihydrodiol approximately equal to 7,8-H2BaP approximately equal to 7,8-H2BaP phenol 2 greater than (+/-)Bap cis-7,8-dihydrodiol greater than BaP approximately equal to 8-hydroxy-7,8-H2BaP greater than 7,8-H2BaP phenol 1 greater than 7-hydroxy-7,8-H2BaP. The results suggest that, in addition to the bay region 7,8,9,10-tetrahydro-BaP 9,10-epoxide, metabolic products formed by hydroxylations at the aliphatic and aromatic carbons of 7,8-H2BaP and their subsequent metabolism at the 9,10-double bond may also contribute to the carcinogenic activities of 7,8-H2BaP.

Nonenzymatic reduction of benzo(a)pyrene diol-epoxides to trihydroxypentahydrobenzo(a)pyrenes by reduced nicotinamide adenine dinucleotide phosphate.

The diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene is a potent mutagen and possibly the ultimate carcinogenic form of benzo(a)pyrene. A (7/8,9)-trihydroxy-7,8,9,10,10-pentahydrobenzo(a)pyrene is formed from the diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydroxybenzo(a)pyrene by reduction with reduced nicotinamide adenine dinucleotide phosphate. Its formation is linear with reduced nicotinamide adenine dinucleotide phosphate concentration and does not require the presence of enzyme. A (7,9/8)-trihydroxy-7,8,9,10,10-pentahydrobenzo(a)pyrene is similarly formed from the diol-epoxide r-7,t-8-dihydroxy-c-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene by reduction with reduced nicotinamide adenine dinucleotide phosphate. The structures of the trihydroxypentahydrobenzo(a)pyrenes were established by their ultraviolet absorption and mass spectra and their reaction with potassium triacetylosmate.

Stereoselectivity of rat liver microsomal enzymes in the metabolism of 7-fluorobenz(a)anthracene and mutagenicity of metabolites.

7-Fluorobenz(a)anthracene (7-FBA) was metabolized by rat liver microsomes predominantly to 4-hydroxy-7-FBA and 7-FBA trans-3,4-, 5,6-, 8,9-, and 10,11-dihydrodiols. Proton nuclear magnetic resonance spectral analyses indicated that the fluoro substituent causes 7-FBA trans-5,6- and 8,9-dihydrodiols to adopt preferentially quasidiaxial conformations (Chiu, P.-L., Fu, P. P., and Yang, S. K. Biochem. Biophys. Res. Commun., 106: 1405-1411, 1982). The major enantiomers of the quasidiaxial trans-5,6- and trans-8,9-dihydrodiols have been determined by the exciton chirality method to have R,R absolute stereochemistries. By comparing with the circular dichroism spectra of BA 3R,4R- and 10R,11R-dihydrodiols, the major enantiomers of the quasidiequatorial 7-FBA trans-3,4- and trans-10,11-dihydrodiols were also found to have R,R absolute configurations. All four 7-FBA trans-dihydrodiol metabolites obtained from incubations of 7-FBA with liver microsomes prepared from untreated and 3-methylcholanthrene-, phenobarbital-, and polychlorinated biphenyl-treated male Sprague-Dawley rats were enriched in R,R enantiomers, differing only in optical purities. Pretreatment of rats with phenobarbital, 3-methylcholanthrene, and polychlorinated biphenyls changed the rate of 7-FBA metabolism by 0.47-, 1.14-, and 1.70-fold, respectively. Pretreatment of rats with enzyme inducers also altered the quantitative distribution of metabolites formed. The relative mutagenic activities of metabolites toward Salmonella typhimurium TA 100 were: 7-FBA trans-3,4-dihydrodiol greater than 7-FBA trans-10,11-dihydrodiol greater than 7-methyl-BA approximately equal to 7-FBA greater than 7-FBA trans-8,9-dihydrodiol approximately equal to 7-methyl-BA trans-10,11-dihydrodiol greater than 7-FBA trans-5,6-dihydrodiol approximately equal to 4-hydroxy-7-FBA. The relatively high mutagenic activities of 7-FBA trans-3,4- and trans-10,11-dihydrodiols suggest that both 7-FBA trans-3,4-dihydrodiol 1,2-epoxide(s) and 7-FBA trans-10,11-dihydrodiol 8,9-epoxide(s) may be the major metabolites which contribute to the carcinogenic properties of 7-FBA.

Metabolism of 7,12-dimethylbenz(a)anthracene and 7-hydroxymethyl-12-methylbenz(a)anthracene by rat liver and microsomes.

The metabolism of 7,12-[14C]dimethylbenz(a)anthracene ([14C]DMBA) and 7-[7-CH2-3H]hydroxymethyl-12-methylbenz(a)anthracene ([7-CH2-3H]7-OHM-12-BMA) by rat liver nuclei and microsomes was studied by high-performance liquid chromatography. DMBA and 7-OHM-12-MBA are metabolized at methyl group(s) and at the aromatic ring carbons to form trans-dihyrodiols at positions 3, 4, 5, 6, 8, 9, and 10,11 and phenols at positions 2, 3, and 4 by both nuclear and microsomal enzymes. Both nuclear and microsomal monooxygenase enzyme activities were inducible by pretreatment of the animals with phenobarbital or 3-methylcholanthrene. The rates of formation of all metabolites by microsomes were five- to 20-fold higher than those by nuclei in metabolizing DMBA or 7-OHM-12-MBA. The presence of a hydroxyl group at the 7-methyl position of DMBA markedly decreased the rate of metabolism. The rate of total metabolism of 7-OHM-12-MBA was only 20 to 70% of that of DMBA under identical in vitro incubation conditions. The 3-methylcholanthrene- and phenobarbital-induced enzymes showed a significantly different regioselectivity toward the metabolism of DMBA or 7-OHM-12-MBA and are attributed to different forms of cytochrome P-450 present in the enzyme preparations.

Metabolism of 6-methylbenz[a]anthracene by rat liver microsomes and mutagenicity of metabolites.

6-Methylbenz[a]anthracene (6-MBA) is metabolized by rat liver microsomes to form 3-hydroxy-6-MBA, 4-hydroxy-6-MBA, 5-hydroxy-6-MBA, 6-MBA trans-3,4-, 5,6-, 8,9-, and 10,11-dihydrodiols, and 4-hydroxy-6-MBA trans-10,11-dihydrodiol as the identifiable metabolites. 6-Hydroxymethylbenz[a]anthracene and its phenolic and dihydrodiol metabolites are also formed. The unique metabolites identified in 6-MBA metabolism are 6-MBA trans-5,6-dihydrodiol and 4-hydroxy-6-MBA trans-10,11-dihydrodiol. Metabolites were isolated by reversed-phase and normal-phase high-performance liquid chromatographies and identified by UV-visible absorption, mass, and proton nuclear magnetic resonance spectral analyses. Metabolites formed by low and high concentrations of liver microsomal enzymes from untreated, phenobarbital-treated, and 3-methylcholanthrene-treated male Sprague-Dawley rats were quantified by using [3H]6-MBA, with the tritium labeled at the methyl carbon, and liquid scintillation counting of fractions collected from reversed-phase high-performance liquid chromatography. Metabolic formations of 6-hydroxymethylbenz[a]anthracene, 6-MBA trans-dihydrodiols, and 4-hydroxy-6-MBA trans-10,11-dihydrodiol are highly dependent on the contents of cytochrome P-450 isozymes present in liver microsomes. The relative mutagenic activities of metabolites toward Salmonella typhimurium TA100 are: 6-MBA trans-3,4-dihydrodiol greater than 6-MBA trans-8,9-dihydrodiol greater than 6-MBA greater than 6-MBA trans-10,11-dihydrodiol greater than 4-hydroxy-6-MBA congruent to 4-hydroxy-6-MBA trans-10,11-dihydrodiol. The relatively high mutagenic activities of 6-MBA trans-3,4-dihydrodiol and 6-MBA trans-8,9-dihydrodiol suggest that both 6-MBA trans-3,4-dihydrodiol 1,2-epoxide(s) and 6-MBA trans-8,9-dihydrodiol 10,11-epoxide(s) may be the major metabolites which contribute to the carcinogenic properties of 6-MBA.

Kinetic analysis of the metabolism of benzo(a)pyrene to phenols, dihydrodiols, and quinones by high-pressure chromatography compared to analysis by aryl hydrocarbon hydroxylase assay, and the effect of enzyme induction.

High-pressure liquid chromatography was used to analyze the rate of benzo(a)pyrene metabolite formation by liver microsomes from control and 3-methylcholanthrene-treated rats. The relative amounts of each metabolite formed were determined with several concentrations of microsomal mixed-function oxidases. The specific activity, i.e., amount formed per mg protein per min, was found to be constant for the formation of 3-hydroxybenzo(a)pyrene and 4,5-dihydro-4,5-dihydroxybenzo(a)pyrene. The specific activity for the formation of 9,10-dihydro-9,10-dihydroxybenzo(a)pyrene was higher at high microsomal enzyme concentration. The formation of 9-hydroxybenzo(a)pyrene, however, did not increase with greater amounts of microsomes. The data indicate that 9-hydroxybenzo(a)pyrene is a nonenzymatic product derived from a reactive intermediate, probably benzo(a)pyrene-9,10-oxide. The relatively constant specific activity for the formation of 4,5-dihydro-4,5-dihydroxybenzo(a)pyrene with several enzyme concentrations suggests that the K-region epoxide, benzo(a)pyrene-4,5-oxide, is the most stable of the benzo(a)pyrene epoxide intermediates. The relative percentages of each metabolite fraction found are as follows: 3-hydroxybenzo(a)pyrene, 36; 9-hydroxybenzo(a)pyrene, 3 to 13; 9,10-dihydro-9,10-dihydroxybenzo(a)pyrene, 15 to 25; 4,5-dihydro-4,5-dihydroxybenzo(a)pyrene, 8; 7,8-dihydro-7,8-dihydroxybenzo(a)pyrene, 12 to 14; benzo(a)pyrene quinones, 14 to 17. Induction of the enzyme system by 3-methylcholanthrene increases the amount of each metabolite formed to a different extent. The amount of 9,10-dihydro-9,10-dihydroxy- and 7,8-dihydro-7,8-dihydroxybenzo(a)pyrene formed are markedly increased relative to the increase in the other metabolites. Thus the induction of the enzyme may specifically alter pathways of metabolism relevant to carcinogenesis. This study also makes a detailed comparison between the results obtained by high-pressure liquid chromatography analysis and the standard aryl hydrocarbon hydroxylase assay and further develops the chromatographic analysis of benzo(a)pyrene metabolites.

Metabolic activation of benzo(a)pyrene and binding to DNA in cultured human bronchus.

Human bronchus is one target site for the carcinogenic action of tobacco smoke, which contains chemical carcinogens, including benzo(a)pyrene. Human bronchi were obtained from surgery or "immediate" autopsy and then cultured in a chemically defined medium. The cultured bronchi were exposed to either benzo(a)pyrene or its metabolites, and their levels of binding to DNA were measured. One of the benzo(a)pyrene metabolites. (-)-trans-7,8-diol, is more active in binding to DNA than benzo(a)pyrene and several of its metabolites, including (-)-trans-4,5-diol, (-)-trans-9,10-diol, and phenols. The predominant metabolite formed by human bronchus from the (-)-trans-7,8-diol is found by high-pressure liquid chromatographic analysis to be the diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene. The results suggest that this diol-epoxide is the major benzo(a)pyrene metabolite bound to DNA in human bronchus.

Effects of sequential feeding with low- and high-protein diets on growth performances and plasma metabolite levels in geese.

This study was conducted by two trials to investigate effects of sequential feeding with low- and high-protein diets on growth traits and plasma metabolites in geese. In Trial I, the effect of sequential feeding under time-restricted feeding system was investigated. Seventy-two White Roman goslings were randomly allotted into either sequential feeding (S1) or control feeding (C1) group. All goslings were fed for 1 h at morning and at evening, respectively, from 2 to 8 weeks of age. S1 group was offered 13% CP diet at morning and 19% CP diet at evening. C1 group was offered the same diet (16% CP; mixed equally with the two diets mentioned above) at both morning and evening. Blood samples were hourly collected for 4 h after feeding at both morning and evening for the determination of the postprandial plasma levels of glucose, triacylglycerol and uric acid at the end of experiment. Results showed that BW, average daily gain (ADG), and daily feed intake (FI) were not different between groups, but the feed efficiency (FE) in S1 group was significantly higher than that in C1 group (P<0.05). The areas under curve (AUC) of plasma postprandial levels of glucose, triacylglycerol and uric acid were not affected by treatment, but the AUC of triacylglycerol and uric acid in morning were lower than those in evening (P<0.05). In Trial II, the effect of sequential feeding under ad libitum feeding system was investigated. Twenty-four goslings were randomly allotted into either sequential feeding (S2) or control feeding (C2) group. Diets were altered at 0600 and 1800 h, respectively, and geese were fed ad libitum from 4 to 8 weeks of age. S2 group was offered 14% CP diet at morning and 20% CP diet at evening. C2 group was supplied the same diet (mixed with the two diets according to the ratio of diets consumed by S2 group on the preceded day) at both morning and evening. Results showed that the ADG in S2 group was higher than those in C2 group (P<0.05). Summarized data from both trials showed that sequential feeding improves daily gain and FE in growing geese.

Comparison of LTBI treatment regimens for patients receiving anti-tumour necrosis factor therapy.

SETTING: A tertiary referral centre in South Korea. OBJECTIVE: To compare the completion rates and adverse drug reactions of three latent tuberculous infection (LTBI) treatment regimens for patients receiving anti-tumour necrosis factor (anti-TNF) therapy. DESIGN: A total of 408 patients were diagnosed with LTBI before receiving anti-TNF therapy between December 2004 and December 2013. Nine months of isoniazid (9H), 4 months of rifampicin (4H) or 3 months of isoniazid/rifampicin (3HR) were prescribed. The results were analysed retrospectively. RESULTS: The mean age of the 408 study subjects was 44 years; 258 (63.2%) were male. The 9H, 4R and 3HR treatment regimens were given to respectively 61 (15.0%), 139 (34.1%) and 208 (51.0%) patients. A total of 362 (88.7%) patients completed the treatment. The treatment completion rate was highest in patients receiving 3HR (94.2%). Of the 408 patients, 54 (13.2%) had one or more adverse drug reactions; their frequency was similar in the three groups. CONCLUSIONS: In patients receiving anti-TNF therapy, 3HR seems to be the most acceptable treatment regimen for LTBI, given its high completion rate and acceptable rate of adverse drug reactions.

Effect of levitra on sustenance of erection (EROS): an open-label, prospective, multicenter, single-arm study to investigate erection duration measured by stopwatch with flexible dose vardenafil administered for 8 weeks in subjects with erectile dysfunction.

To investigate the change of erection duration measured by stopwatch with flexible dose vardenafil administered for 8 weeks in subjects with erectile dysfunction (ED). Effect of levitra on sustenance of erection was an open-label, prospective, multicenter and single-arm study designed to measure the duration of erection in men with ED receiving a flexible dose of vardenafil over an 8-week treatment period. Patients were instructed to take vardenafil 10 mg 60 min before attempting the intercourse. Vardenfil could be increased to 20 mg or decreased to 5 mg concerning patients' efficacy and safety. Following the initial screening, patients entered a 4-week treatment-free run-in phase and 8-week treatment period, during which they were instructed to attempt intercourse at least four times on four separate days. A total of 95 men were enrolled in 10 centers. After the 8 weeks treatment, the mean duration of erection leading to successful intercourse was statistically superior when patients were treated with vardenafil. After an 8-week treatment, the duration of erection leading to successful intercourse was 9.39 min. There were significant benefits with vardenafil in all domains of International Index of Erectile Function. Secondary efficacy end points included success rate of penetration, maintaining erection, ejaculation and satisfaction were superior when patients were treated with vardenafil. There was a significant correlation between duration of erection with other sexual factors. Also partner's sexual satisfaction was increased with vardenafil. Most adverse events were mild or moderate in severity. Vardenafil was safe and well tolerated. Vardenafil therapy provided a statistically superior duration of erection leading to successful intercourse in men with ED with female partner.