Nutrient removal and microbial granulation in an anaerobic process treating inorganic and organic nitrogenous wastewater

The sustainable anaerobic nitrogen removal and microbial granulation were investigated by using a laboratory anaerobic granular sludge bed reactor, treating synthetic (inorganic and organic) wastewater and piggery waste. From inorganic synthetic wastewater, lithoautotrophic ammonium oxidation to nitrite/nitrate was observed by an addition of hydroxylamine. Also, the results revealed that the Anammox intermediates (particularly, hydrazine) contents in the substrate would be one of the important parameters for success of the anaerobic nitrogen removal process. The results from organic synthetic wastewater show that if the Anammox organism were not great enough in the startup of the process, denitritation and anaerobic ammonification would be a process prior to the Anammox reaction. The anaerobic ammonium removal from the piggery waste was performed successfully, probably due to the Anammox intermediates contained in the substrate. This reactor shows a complex performance including the Anammox reaction and HAP crystallization, as well as having partial denitritation occurring simultaneously. From the activity test, the maximum specific N conversion rate was 0.1 g NH4-N/g VSS/day (0.77 g T-N/g VSS/day), indicating that potential denitritation is quite high. The NO2-N/NH4-N ratio to Anammox is 1.17. The colour of the biomass treating the piggery waste changed from black to dark red. It was also observed that the red-colored granular sludge had a diameter of 1-2 mm. The settleability assessment of the granular sludge revealed that the granular sludge had a good settleability even though it was worse than that of seed granular sludge.

Afferent loop obstruction after gastric cancer surgery: helical CT findings

BACKGROUND

We reviewed the computed tomographic (CT) findings of afferent loop obstruction and assessed the value of helical CT in determining the underlying cause.

METHODS

Helical CT scans of 18 patients (12 men and six women; age range = 35-67, mean age = 50 years) with afferent loop obstruction were reviewed. All patients had gastric cancer. Ten patients had undergone radical subtotal gastrectomy with Billroth II gastrojejunostomy, and eight had undergone total gastrectomy with Roux-en-Y esophagojejunostomy. CT images were analyzed retrospectively, and the presumed cause of obstruction on CT was compared with surgical findings (n = 8) and clinical courses (n = 10).

RESULTS

Local recurrence (n = 15), peritoneal seeding (n = 1), internal hernia (n = 1), and adhesion (n = 1) were the presumed causes of obstruction on CT. In all eight patients who underwent a second operation, the cause of afferent loop obstruction was correctly suggested on CT (local recurrence in six patients and adhesion and internal hernia in one patient). In 10 patients who were not re-explored, the clinical findings or biopsy indicated recurrent tumor as suggested on CT.

CONCLUSION

Recurrent tumors and other potential causes of afferent loop obstruction can be correctly predicted with CT in most cases.

Inhibitory effects of novel E2F decoy oligodeoxynucleotides on mesangial cell proliferation by coexpression of E2F/DP

Proliferation of glomerular mesangial cells (MCs) is an important feature of several forms of glomerulonephritis. The transcription factor E2F coordinately regulates expression of genes required for cell proliferation, thereby mediating cell growth control. Here we investigated the role of E2F1 and E2F4 expression, with or without co-expression of DP1 or DP2, on cell proliferation in transiently transfected primary rat MCs. In transfected cells, cell proliferation induced by over-expression of E2F was significantly enhanced by co-expression of DP proteins. Previous studies showed that the transfection of decoy oligodeoxynucleotides (ODNs) corresponding to E2F binding sites inhibits cell proliferation. Here we have developed a Ring-E2F (R-E2F) decoy ODN with a circular dumbbell structure and compared its effects with those of a phosphorothioated E2F decoy (PS-E2F decoy) ODN. The R-E2F decoy ODN showed enhanced stability in the presence of nucleases and sera, and inhibited E2F/DP-dependent promoter activity of cell cycle genes more effectively than the PS-E2F decoy ODN. Transfection of R-E2F decoy ODN resulted in strong inhibition of cell cycle gene expression and MC proliferation. Our data suggest that E2F/DP complexes play a critical role in the MC proliferation and that the R-E2F decoy ODN may be a powerful tool for inhibiting cell proliferation.

Modulation of Sp1-dependent transcription by a cis-acting E2F element in dhfr promoter

The dihydrofolate reductase (dhfr) promoter contains cis-acting elements for Sp1 and E2F. Here we examined the cooperative regulation of dhfr gene transcription by Sp1 and E2F in human osteosarcoma cells, U2OS. Trichostatin A, an inhibitor of histone deacetylases, markedly stimulated dhfr promoter activity, a response that was enhanced by the deletion of an E2F element. In contrast, deletion of the dhfr Sp1 binding sites completely abolished promoter stimulation by trichostatin A. Cotransfection assays showed that activation of dhfr transcription by expression of E2F1/DP1 requires the reiterated Sp1 elements, whereas activation by Sp1 was enhanced by the deletion of the E2F element. Expression of HDAC1 with Sp1 suppressed promoter activity and suppression was not alleviated by coexpression of E2F1/DP1. These results suggest that HDAC1 acts through Sp1 to repress dhfr promoter activity, and that the E2F element modulates the activity of Sp1 at the dhfr promoter through a cis-acting mechanism.

Characterization of B cell membrane receptors of polysaccharide isolated from the root of Acanthopanax koreanum

We investigated the immunomodulatory activity of polysaccharide isolated from the root of Acanthopanax koreanum (AK) at the cellular level. AK directly increased B cell proliferation and antibody production, but did not affect the expression of IL-2, IFN-gamma or IL-4 by T cells, or T cell proliferation in vitro. Since AK cannot penetrate cells due to its large molecular mass, B cell activation may be caused by the surface binding of AK to B cell-specific receptors. The role of TLR4 as an AK receptor was shown by the fact that AK activity in B cells from C3H/HeJ mice, which are known to have a defective Toll-like receptor (TLR)-4, was found to be reduced compared with that in control cells from C3H/HeN mice. AK activity was also reduced by antibodies blocking TLR2, TLR4, CD19 or CD79b, but not by an antibody blocking CD38, which suggests AK receptor profiling in B cells. Two main differences between AK and lipopolysaccharide (LPS) were observed. First, LPS activity was inhibited by antibodies to either TLR2 or TLR4, but not by antibodies to CD19, CD79b or CD38. Another was that LPS-induced B cell proliferation was inhibited by polymyxin B (PMB), a specific inhibitor of LPS, whereas AK activity was not affected. Taken together, our results demonstrate that AK directly activates B cells, but not T cells, and suggest that AK has a broader receptor profile than LPS in B cells.

Structural basis for the NAD-dependent deacetylase mechanism of Sir2

The NAD-dependent histone/protein deacetylase activity of Sir2 (silent information regulator 2) accounts for its diverse biological roles including gene silencing, DNA damage repair, cell cycle regulation, and life span extension. We provide crystallographic evidence that 2'-O-acetyl ADP-ribose is the reaction product that is formed at the active site of Sir2 from the 2.6-A co-crystal structure of 2'-O-acetyl-ADP-ribose and Sir2 from Archaeoglobus fulgidus. In addition, we show that His-116 and Phe-159 play critical roles in the catalysis and substrate recognition. The conserved Ser-24 and Asp-101 contribute to the stability for NAD binding rather than being directly involved in the catalysis. The crystal structures of wild type and mutant derivatives of Sir2, in conjunction with biochemical analyses of the mutants, provide novel insights into the reaction mechanism of Sir2-mediated deacetylation.

hMLH1 and hMSH2 mutations in families with familial clustering of gastric cancer and hereditary non-polyposis colorectal cancer

The pattern of hMLHI and hMSH2 mutations was assessed to identify the genetic correlation between hereditary gastric and colorectal cancers. Four disease groups and their healthy family members were assembled according to the presentation of gastric cancer: FG, familial clustering of gastric cancer (n = 32); CG, family with one or more colorectal and gastric cancers in first-degree relatives (n = 22); HS, seven HNPCC families corresponding to the Amsterdam criteria (AMS+) and 12 suspected HNPCC families which did not satisfy one of the criteria (AMS-), but no gastric cancer among first- and second-degree relatives (n = 19); and SG, sporadic gastric cancer (n = 33). In the CG group, three were included in AMS + and six in AMS- criteria. Peripheral blood was obtained from them to detect hMLHI and hMLH2 mutations using PCR-SSCP analysis and direct sequencing. The incidence of mutations was 9.4% in the FG group, 54.5% in the CG group, 31.6% in the HS group, and none in the SG group. The incidence, type, and number of the mutation were not different between the CG and HS groups. Thirty-four different mutations included 19 in hMLH1 and 15 in hMSH2. Gastric cancer was the most common extracolonic malignancy in HNPCC and suspected HNPCC families (9/28, 32.1%). The hMLH1 or hMSH2 mutation occurred in seven of 10 families with AMS+, whereas it occurred in four of 18 with AMS- (70% vs. 22.2%, P = .013). Five mutations in the hMLH1 and six mutations in the hMSH2 were exclusively found in families with gastric cancer. All three mutations in the FG group were in hMLHI and there was no mutation in their healthy family members. This study demonstrates that some familial clustering type of gastric cancer appears to be associated with hMLHI mutations thereby indicating a difference from the hereditary gastric cancer studies previously reported. In addition, hMLHI and hMSH2 mutations may impact the gastric cancer carcinogenesis in HNPCC or suspected HNPCC.

Effects of pine bark extract administered to immunosuppressed adult mice infected with Cryptosporidium parvum

The treatment of cryptosporidiosis using pine bark extract (Pycnogenol) in immunosuppressed adult C57BL/6N mice infected with Cryptosporidium parvum was investigated. Five groups of 10 mice/group were used. Groups 1, 2, 3, and 5 served as normal, toxicity, placebo, and positive controls, respectively. Mice in groups 2-5 were immunosuppressed with dexamethasone phosphate administered ad libitum in drinking water at a dosage level of 12 microg/ml. Mice in groups 3-5 were inoculated per os with 10(6) C. parvum oocysts on the day immunosuppression was started. Mice in groups 2 and 4 were treated by administering Pycnogenol orally at 30 mg/kg/day. In group 4, Pycnogenol was first administered on day 3 postinoculation. Of the four groups of mice immunosuppressed with DEXp (groups 2-5), the two groups treated with Pycnogenol (groups 2 and 4) had no premature deaths. The other two groups (groups 3 and 5) had 3 and 4 mice die, respectively, before the experiment ended. Consequently, Pycnogenol was judged to be non-toxic at the dosage level used and even afforded mice some positive health benefits. Fecal oocyst shedding in groups 3-5 was initially detected on day 3 postinoculation. These mice continued to shed oocysts throughout the duration of the 28-day experiment. Oocyst shedding intensities were greater in group 3 and 5 than in group 4. However, histological examination of infected intestinal tissues in groups 3-5 revealed no significant difference with regard to parasite colonization and villus/crypt (V/C) length ratios. As a result, Pycnogenol was determined to be therapeutically effective against C. parvum at 30 mg/kg/day only when measured by fecal oocyst shedding intensity. There was no effect on parasite tissue colonization and V/C ratios in infected mice. We conclude that Pycnogenol is a useful dietary supplement for C. parvum-infected patients by affording some positive health benefits, significantly reduces fecal oocyst shedding, but does not decrease parasite colonization of intestinal tissue.

Expression of multidrug resistance-associated protein1,P-glycoprotein, and thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

Both 5-fluorouracil and doxorubicin are commonly used agents in chemotherapy of gastric cancer in adjuvant setting as well as metastatic disease. In a variety of malignancies, high expression of multidrug resistance-associated protein1 and P-glycoprotein has been associated with resistance to doxorubicin, whereas 5-fluorouracil resistance has correlated with the level of thymidylate synthase expression. We evaluated the expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase using immunohistochemistry in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection and investigated the association between their expression and clinicopathologic characteristics including prognosis of the patients. While high expression (> or =5% of tumour cells positive) of multidrug resistance-associated protein1 and P-glycoprotein was observed in 70 patients (68%) and 42 patients (41%), respectively, 65 patients (63%) had primary tumours with high expression (> or =25% of tumour cells positive) of thymidylate synthase. There was a significant association between multidrug resistance-associated protein1 and P-glycoprotein expression (P<0.0001) as well as P-glycoprotein and thymidylate synthase expression (P<0.0001). High multidrug resistance-associated protein1 and P-glycoprotein expressions were associated with well and moderately differentiated histology (P<0.0001 and P=0.03, respectively) and intestinal type (P<0.0001 and P=0.009, respectively). High multidrug resistance-associated protein1 expression correlated with lymph node metastasis (P=0.037), advanced stage (P=0.015), and older age (P=0.021). Five-year disease-free survival and overall survival of total patients were 55.2% and 56.2%, respectively, with a median follow-up of 68 months. There were no significant differences in disease-free survival and overall survival according to the expression of multidrug resistance-associated protein1 (P=0.902 and P=0.975, respectively), P-glycoprotein (P=0.987 and P=0.955, respectively), and thymidylate synthase (P=0.604 and P=0.802, respectively). Concurrent high expression of these proteins (high multidrug resistance-associated protein1/P-glycoprotein, high multidrug resistance-associated protein1/thymidylate synthase, high P-glycoprotein/thymidylate synthase) did not correlate with disease-free survival or overall survival. Even high expression of all three proteins was not associated with poor disease-free survival (P=0.919) and overall survival (P=0.852). In conclusion, high expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase did not predict poor prognosis of gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy. A larger study including patients treated with surgical resection alone would be necessary.

Ramosetron for the prevention of cisplatin-induced acute emesis: a prospective randomized comparison with granisetron

Control of nausea and vomiting is very important in determining patient compliance with cisplatin chemotherapy. A multicentre, randomized, single-blind study was conducted to compare the tolerability and efficacy of ramosetron with those of granisetron over 24 h following cisplatin administration to cancer patients. In eight study centres, a total of 194 adult patients were randomly assigned to receive either intravenous ramosetron 0.3 mg or intravenous granisetron 3.0 mg. The anti-emetic effect of ramosetron determined from the no-vomiting rate lasted longer, but there was no significant difference in the number of acute vomiting episodes or the severity of nausea between the two groups. In the tolerability evaluation, there were no statistically significant differences between the two groups, except for a higher incidence of dull headache in the granisetron group. Ramosetron and granisetron appear to have equivalent efficacy and tolerability profiles, but the effects of ramosetron on the prevention of acute vomiting in patients undergoing cisplatin chemotherapy were longer lasting.

An insight into the genetic pathway of adenocarcinoma of the small intestine

BACKGROUND

Although the adenoma to carcinoma pathway in colorectal cancer is well described, the mechanisms of carcinogenesis in the small intestine remain unclear.

AIMS

The aim of this study was to investigate candidate genes in the genetic pathway of adenocarcinoma of the small intestine.

SUBJECTS AND METHODS

A total of 21 non-familial, non-ampullary adenocarcinomas of the small intestine were analysed. DNA was extracted from formalin fixed paraffin wax embedded tissue using standard techniques. The replication error (RER) status was determined by amplification of BAT26. The mutation cluster region (MCR) of the adenomatous polyposis coli (APC) gene was screened using polymerase chain reaction single strand conformational polymorphism and direct sequencing. Immunohistochemistry was performed on formalin fixed paraffin wax embedded tissue using monoclonal antibodies for hMLH1, hMSH2, beta-catenin, E-cadherin, and p53.

RESULTS

Fourteen male and seven female patients with a median age of 64 years (range 21-85) presented with adenocarcinoma of the duodenum (10), jejunum (7), and ileum (4). One cancer (5%) was found to be RER+, and all tumours stained positive for hMLH1 and hMSH2. No mutations were detected in the MCR of the APC gene. beta-Catenin showed increased nuclear expression with loss of membranous staining in 10 cancers (48%). Absent or decreased membrane expression of E-cadherin was found in eight cancers (38%). Strong staining of p53 was found in the nucleus of five cancers (24%).

CONCLUSION

We did not detect mutations in the MCR of the APC gene, and this suggests that adenocarcinoma of the small intestine may follow a different genetic pathway to colorectal cancer. Abnormal expression of E-cadherin and beta-catenin was common and reflects an early alternative to APC in this pathway in which mutations may be found in adenocarcinoma of the small intestine.

Ozonation of Han River humic substances

This study investigated the characteristics of extracted humic substances (HS) which are ubiquitous in river waters and affect the treatment of the water. HS were extracted from the Han River and the samples obtained were analyzed before/after oxidation with the following analytical methods: DOC, THMFP, UV-abs, chemical composition, molecular weight distribution, IR. Ozonation experiments were conducted in batch-type reactors. Ozone dose was 1 mg/L and contact time was varied from 0 to 20 minutes. The fraction of hydrophobic matter was 56.0% of total organic carbon in the Han River and the ratio of humic/fulvic acids was 22.4/77.6, showing high fractions of aromatic and/or double carbon bond functional groups and high fractions of saturated aliphatic carbons. Oxygen fraction of Han HS was relatively high compared with other humic substances (Suwannee River humic and fulvic acids), which are consistent with the results of IR spectra. The IR spectra showed the increase in aliphatic groups by ozonation of the Han HS. Humic substances could not completely be oxidized to CO2, H2O etc., but were partly oxidized to low molecular weight matter (aliphatics, aldehydes, carboxylics, polysaccharides etc.), so low removal efficiencies in terms of DOC (31-35% with 5 minute contact) were observed. For UV254, 5 minute or shorter contact showed more than 80% removal efficiencies.

Glucocorticoids exacerbate peroxynitrite mediated potentiation of glucose deprivation-induced death of rat primary astrocytes

Glucocorticoids have been implicated in the exacerbation of several types of neurotoxicity in various neuropathological situations. In this study, we investigated the effect of a glucocorticoid dexamethasone on glucose deprivation induced cell death of immunostimulated rat primary astrocytes, which is dependent on the production of peroxynitrite from the immunostimulated cells [Choi et al. Glia, 31(2001) 155-164; J. Neuroimmunol. 112 (2001) 55-62]. Glucose deprivation in immunostimulated rat primary astrocytes results in the release of lactate dehydrogenase (LDH) after 5 h and co-treatment with dexamethasone (1-1000 nM) dose-dependently increased LDH release. Treatment of the exogenous peroxynitrite generator SIN-1 (20 microM), plus glucose deprivation, also increased LDH release after 6 h and co-treatment with dexamethasone dose-dependently increased LDH release. A glucocorticoid receptor antagonist, RU-486, reversed the potentiation of cell death by dexamethasone. Glucose deprivation in immunostimulated cells decreased the intracellular ATP levels, which preceded LDH release from the cell, and co-treatment with dexamethasone dose-dependently potentiated the depletion of intracellular ATP levels. In addition, dexamethasone further deteriorated SIN-1 plus glucose deprivation-induced decrease in mitochondrial transmembrane potential in rat primary astrocytes, which was reversed by RU-486. The results from the present study suggest that glucocorticoids may be detrimental to astrocytes in situations where activation of glial cells are observed, including ischemia and Alzheimer's disease, by mechanisms involving depletion of intracellular ATP levels and deterioration of mitochondrial transmembrane potentials.

Dehydroepiandrosterone inhibits the death of immunostimulated rat C6 glioma cells deprived of glucose

Pretreatment of interferon-gamma and lipopolysaccharides made C6 glioma cells highly vulnerable to glucose deprivation. Neither 12 h of glucose deprivation nor 2-day treatment with interferon-gamma (100 U/ml) and lipopolysaccharides (1 microg/ml) altered the viability of C6 glioma cells. However, significant death of immunostimulated C6 glioma cells was observed after 5 h of glucose deprivation. The augmented death was prevented by dehydroepiandrosterone (DHEA) treatment during immunostimulation, but not by DHEA treatment during glucose deprivation. DHEA reduced the rise in nitrotyrosine immunoreactivity, a marker of peroxynitrite, and superoxide production in glucose-deprived immunostimulated C6 glioma cells. DHEA, however, did not protect glucose-deprived C6 glioma cells from the exogenously produced peroxynitrite by 3-morpholinosydnonimine. Further, DHEA did not alter the production of total reactive oxygen species and nitric oxide in immunostimulated C6 glioma cells. Superoxide dismutase (SOD) and the synthetic SOD mimetic Mn(III)tetrakis (4-benzoic acid) porphyrin inhibited the death of glucose-deprived immunostimulated C6 glioma cells. In addition, a superoxide anion generator paraquat reversed the protective effect of DHEA on the augmented death. The data indicate that DHEA prevents the glucose deprivation-evoked augmented death by inhibiting the production of superoxide anion in immunostimulated C6 glioma cells.

Polychlorinated biphenyls activate caspase-3-like death protease in vitro but not in vivo

We prove here that serum albumin inhibits apoptosis induced by polychlorinated biphenyls (PCBs), confirming that serum albumin binds to PCB, and that the albumin-PCB complexes inhibit apoptosis in HL-60 cells. We found that PCB (50 microM) increased the activity of caspase-3-like protease when HL-60 cells, as well as splenocytes, were cultured in "serum-free medium." Benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-fmk) inhibited apoptosis in cells cultured in the serum-free medium containing 50 microM PCB. To elucidate whether or not PCBs induce apoptosis in vivo, we examined apoptosis of splenocytes by administering PCB to ICR mice (100, 500, 1000 mg x kg(-1) x d(-1)) for 5 d and characterizing splenocytes. Interestingly, splenocytes treated with PCB did not show any changes characteristic of apoptosis. These results demonstrate that PCB activates the caspase-3-like death protease in vitro in serum-free medium, but does not induce apoptosis of splenocytes in vivo, suggesting that blood serum may mask the apoptosis induced by PCB.