Genetic improvement of bacteria for enhanced biological removal of phosphate from wastewater.
Explore the source record for details and available documents.
Bacteria↗
Biomedical subjects
A Kuroda
Publications and source records attributed to A Kuroda.
Monokine stimulation of interleukin-11 production by human vascular smooth muscle cells in vitro.
Human vascular smooth muscle cells (VSMC) are a component of blood vessels, and secrete a variety of cytokines in atherosclerotic loci. Interleukin-11 (IL-11), a member of IL-6-like cytokines, is reported to be involved in inflammation and tissue remodeling, both of which are observed in atherosclerosis. However, no information is available as to the production of IL-11 by VSMC. Therefore, the expression of IL-11 in VSMC is investigated. The amounts of IL-11 protein and mRNA were determined by enzyme-linked immunosorbent assay (ELISA) and Northern blot analysis, respectively. The expression of IL-11 in VSMC was also immunohistochemically determined. IL-1 alpha, transforming growth factor-beta (TGF beta) and, to a lesser extent, tumor necrosis factor-alpha (TNF alpha) stimulated the IL-11 production by VSMC, and the stimulatory effects of IL-1 alpha and TGF beta on IL-11 production were dose-dependent. IL-1 alpha and TNF alpha synergistically augmented TGF beta-stimulated IL-11 production by VSMC. Immunohistochemical staining also revealed the expression of IL-11 protein in VSMC. Furthermore, IL-1 alpha, TGF beta, and TNF alpha induced IL-11 gene expression in VSMC. Because IL-6-like cytokines are reported to be cytoprotective, monokine-stimulated IL-11 may have a potent protective role in atherosclerotic lesions.
Arteriosclerosis↗
Synthesis and biological activity of 4-methyl-3,5-dioxane derivatives as thromboxane A2 receptor antagonists.
The synthesis and biological activity of novel 4-methyl-3,5-dioxane analogues are described. All compounds were produced through modification of the substituent formally corresponding to the omega-octenol side chain of thromboxane A2 (TXA2), in reference to the structure of SQ29548. Several compounds were found to be potent TXA2 receptor antagonists. Compound 8b was the most effective inhibitor of 9,11-epoxymethano PGH2 (U-46619)-induced human platelet aggregation (IC50 = 7.4 nM).
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
Cloning and characterization of Pseudomonas putida genes encoding the phosphate-specific transport system.
The pstSCAB genes of Pseudomonas putida PRS2000, encoding the phosphate (Pi)-specific transport (Pst) system, were cloned. The pstS gene of Pseudomonas aeruginosa PAO1, of which the pstCAB genes had been cloned previously, was also cloned (Nikata, T. et al., Mol. Gen. Genet., 250, 692-698, 1996). The predicted translation products of the P. putida pstSCAB genes showed 83, 75, 78 and 88% amino acid identity with their P. aeruginosa counterparts. Two well-conserved Pho box sequences were found in the region upstream of the pstS gene (15/18 base identity with the consensus Pho box sequence) and in the intercistronic region between the pstS and pstC genes (11/18 base identity) of P. putida PRS2000. To investigate the functions of PstSCAB, the pstSC genes were inactivated by inserting a kanamycin resistance gene cassette into the chromosome of P. putida PRS2000. The resultant mutant, designated PNT1, failed to take up 32Pi even under conditions of Pi limitation. Strain PNT1 was also constitutive for alkaline phosphatase synthesis, as well as chemotaxis toward Pi, indicating that the Pst system is involved in the negative regulation of the pho regulon in P. putida. Although overexpression of the pstSCAB genes in P. putida PRS2000 resulted in decreased cell growth, this recombinant strain could remove Pi at a rate similar to that seen with the control strain.
Journal Article↗
Isolation and characterization of two cryptic plasmids in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11.
Two plasmids were discovered in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11, which was isolated from activated sludge. The plasmids, designated pAYS and pAYL, were relatively small, being approximately 1.9 kb long. They were cryptic plasmids, having no detectable plasmid-linked antibiotic resistance or heavy metal resistance markers. The complete nucleotide sequences of pAYS and pAYL were determined, and their physical maps were constructed. There existed two major open reading frames, ORF1 in pAYS and ORF2 in pAYL, each of which was more than 500 bp long. The predicted product of ORF2 was 28% identical to part of the replication protein of a Bacillus plasmid, pBAA1. However, no significant similarity to any known protein sequences was detected with the predicted product of ORF1. pAYS and pAYL had a highly homologous region, designated HHR, of 262 bp. The overall identity was 98% between the two nucleotide sequences. Interestingly, HHR-homologous sequences were also detected in the genomes of ENI-11 and the plasmidless strain Nitrosomonas europaea IFO14298. Deletion analysis of pAYS and pAYL indicated that HHR, together with either ORF1 or ORF2, was essential for plasmid maintenance in ENI-11. To our knowledge, pAYS and pAYL are the first plasmids found in the ammonia-oxidizing autotrophic bacteria.
Amino Acid Sequence↗
Cloning and characterization of chemotaxis genes in Pseudomonas aeruginosa.
Two chemotaxis-defective mutants of Pseudomonas aeruginosa, designated PC3 and PC4, were selected by the swarm plate method after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. These mutants were not complemented by the P. aeruginosa cheY and cheZ genes, which had been previously cloned (Masduki et al., J. Bacteriol., 177, 948-952, 1995). DNA sequences downstream of the cheY and cheZ genes were able to complement PC3 but not PC4. Sequence analysis of a 9.7-kb region directly downstream of the cheZ gene found three chemotaxis genes, cheA, cheB, and cheW, and seven unknown open reading frames (ORFs). The predicted translation products of the cheA, cheB, and cheW genes showed 33, 36, and 31% amino acid identity with Escherichia coli CheA, CheB, and CheW, respectively. Two of the unknown ORFs, ORF1 and ORF2, encoded putative polypeptides that resembled Bacillus subtilis MotA (40% amino acid identity) and MotB (34% amino acid identity) proteins, respectively. Although P. aeruginosa was found to have proteins similar to the enteric chemotaxis proteins CheA, CheB, CheW, CheY, and CheZ, the gene encoding a CheR homologue did not reside in the chemotaxis gene cluster. The P. aeruginosa cheR gene could be cloned by phenotypic complementation of the PC4 mutant. This gene was located at least 1,800 kb away from the chemotaxis gene cluster and encoded a putative polypeptide that had 32% amino acid identity with E. coli CheR.
Amino Acid Sequence↗
Pancreatic disorders associated with anomalous pancreaticobiliary junction.
BACKGROUND: The aim of this study was to establish an optimal management strategy for pancreatic disorders associated with anomalous pancreaticobiliary junction (APBJ). METHODS: In 64 adult surgical cases of APBJ (common channel 15 mm or longer) (43 with and 21 without choledochal cyst), associated pancreatic disorders, pancreatographic results, and treatment outcomes were analyzed. RESULTS: Of 64 patients, 56 had pancreatobiliary symptoms. Twenty-four patients (38%) had pancreatic disorders: acute pancreatitis (n = 20), chronic calcifying pancreatitis (n = 2), and pancreatic carcinoma (n = 2). Twenty patients (31%) had abnormal pancreatograms. The incidence of acute pancreatitis was significantly higher in patients with an abnormal pancreatogram, particularly dilatation, protein plugs or stones of the common channel or main pancreatic duct, and coexisting pancreatic ductal anomaly. All patients with choledochal cyst underwent cyst excision and hepaticojejunostomy. Eleven patients without choledochal cyst or pancreatobiliary carcinoma underwent cholecystectomy alone. Protein plugs and pancreatic stones were extracted through the bile duct stump or by sphincterotomy. No patients experienced pancreatitis during a mean postoperative follow-up of 6.7 years. CONCLUSIONS: In managing APBJ, attention should be paid to the possibility of associated pancreatic disorders and an abnormal pancreatogram. APBJ with choledochal cyst requires cyst excision. Cholecystectomy alone may be adequate for APBJ without cyst.
Adolescent↗
Interleukin-1alpha and tumor necrosis factor alpha synergistically stimulate prostaglandin E2-dependent production of interleukin-11 in rheumatoid synovial fibroblasts.
OBJECTIVE: Interleukin-11 (IL-11), an IL-6-type cytokine, is thought to be involved in bone resorption via osteoclast differentiation. Here, we characterized the combined effect of IL-1alpha and tumor necrosis factor alpha (TNFalpha), major cytokines in the rheumatoid synovium, on the production of IL-11 by cultured rheumatoid synovial fibroblasts (RSFs). METHODS: The amounts of IL-11, IL-6, and prostaglandin E2 (PGE2) were measured by enzyme-linked immunosorbent assay. IL-11 messenger RNA (mRNA) levels were determined by Northern blotting. Protein expression of cytosolic phospholipase A2 (cPLA2), cyclooxygenase 2 (COX-2), and protein kinase C (PKC) isoforms were determined by Western blotting. RESULTS: IL-1alpha and TNFalpha synergistically stimulated RSFs to produce IL-11 at both the mRNA and protein levels. This synergistic effect was completely inhibited by indomethacin. The inhibition was prevented by PGE2, indicating that the synergistic effect of IL-1alpha and TNFalpha was PGE2-mediated. The cooperative effects of these 2 cytokines were also observed in the production of PGE2 and the expression of 2 regulatory enzymes in PGE2 production, cPLA2 and COX-2. The synergistic induction of IL-11 by IL-1alpha and TNFalpha was completely inhibited by a potent inhibitor of all isoforms of PKC, GF109203X. In contrast, phorbol myristate acetate, which induced a down-regulation of PKC, degrading all PKC isoforms except atypical PKC, did not affect the induction of IL-11. CONCLUSION: These findings suggest that IL-1alpha and TNFalpha synergistically stimulate the production of IL-11 via their effects on PGE2 production in the rheumatoid joint, and that atypical PKC may be another target for down-regulation of IL-11, the bone resorption-associated cytokine.
Arthritis, Rheumatoid↗
Differential inhibitory effects of indomethacin, dexamethasone, and interferon-gamma (IFN-gamma) on IL-11 production by rheumatoid synovial cells.
IL-11, a member of the IL-6 type cytokines, has some biological activity related to the joint destruction in rheumatoid arthritis (RA), such as induction of osteoclast differentiation. However, its expression and regulation in rheumatoid inflamed joints has not been clarified. In the present study we examined the capacity of fresh rheumatoid synovial cells (fresh RSC) to produce IL-11, and the effect of indomethacin, dexamethasone and IFN-gamma on IL-11 production. Fresh RSC obtained from eight patients with RA produced large amounts of IL-11, measured by ELISA, and showed strong expression of IL-11 mRNA, determined by Northern blotting. Indomethacin inhibited the production of IL-11 by about 55%. Prostaglandin E2 (PGE2) completely prevented the inhibition, suggesting that IL-11 production by fresh RSC was in part mediated by PGE2. Dexamethasone inhibited the production of IL-11 by more than 80%. Interestingly, the inhibition was not abolished by PGE2. IFN-gamma inhibited the production of IL-11 from IL-1alpha-stimulated cultured rheumatoid synovial fibroblasts, although IFN-gamma did not inhibit the production of IL-11 by fresh RSC. These results suggest that the production of IL-11 by rheumatoid synovia was differentially regulated by PGE2 and IFN-gamma, and that treatment with indomethacin or dexamethasone decreased the level of IL-11 at inflammatory joints in patients with RA.
Aged↗
Problems in the diagnosis and treatment of a so-called mucin-producing tumor of the pancreas.
Reports of a so-called "mucin-producing tumor of the pancreas" are increasing worldwide. Although the clinicopathologic features and therapeutic strategies of this tumor have been enthusiastically investigated, there are still many unanswered questions regarding this ailment. In this study, problems in the diagnosis and treatment of mucin-producing tumor were analyzed, based on the 259 reported cases of this tumor. The overall 5-year survival rate for resected cases is 83%, which is much higher than that for ordinary duct cell carcinoma (17.3%). However, the 5-year survival rate for carcinoma cases with infiltration into other organs is 28%, which is much lower than those for carcinoma cases without infiltration (86%) and carcinoma cases with infiltration that remained within the pancreatic parenchyma (74%). These results demonstrate that patients with this tumor have a poor prognosis if the tumor infiltrates other organs. In addition, when the spread of the tumor is >6 cm, the prognosis is significantly worse than when the tumor has a spread of <6 cm. The significance of using the presence of K-ras mutation in the pancreatic juice for diagnosis of this tumor and problems of duodenum-preserving pancreatic head resection are discussed.
Adenocarcinoma, Mucinous↗
Enhanced utilization of phosphonate and phosphite by Klebsiella aerogenes.
Klebsiella aerogenes ATCC 9621 was able to utilize phosphonates (Pn), including aminoethylphosphonate, ethylphosphonate, methylphosphonate (MPn), and phosphonoacetate, and inorganic phosphite (Pt) as sole sources of phosphorus (P). The products of the phn gene cluster were absolutely required for Pn breakdown and Pt oxidation to inorganic phosphate (Pi) in this organism. To determine if K. aerogenes ATCC 9621 could be engineered to enhance the utilization of Pn and Pt, a multicopy plasmid, pBI05, which carried the entire phn gene cluster, was introduced into this strain. Despite the increased dosage of the phn genes, K. aerogenes ATCC 9621(pBI05) could utilize only up to 1.1-fold more Pn and Pt than did the control strain with the parent vector alone. These results suggested that Pi, which was generated from Pn and Pt, might limit further utilization of these P compounds. Consequently, to convert the resulting Pi to polyphosphate (polyP), the plasmid pKP28, which carried the K. aerogenes ppk gene (which encodes polyP kinase), was introduced into K. aerogenes ATCC 9621(pBI05). Overexpression of the ppk gene in K. aerogenes ATCC 9621(pBI05, pKP28) resulted in a 2.5-fold increase in Pt utilization over that of the control strain. This recombinant strain also accumulated approximately sixfold more P than did the control strain when the cells were grown with MPn as a sole source of P.
Biotransformation↗
Development of a genetic transformation system for an alga-lysing bacterium.
Four marine bacteria, Alteromonas sp. strains A27, A28, A29, and A30, that lyse the diatom Skeletonema costatum NIES-324 were isolated from coastal seawater samples. They were also able to lyse the diatoms Thalassiosira sp. and Eucampia zodiacs and the raphidophycean flagellate Chattonella antiqua. Cryptic indigenous plasmids, designated pAS28 and pAS29, were detected in Alteromonas sp. strains A28 and A29, respectively. These plasmids appeared to be similar based on size and restriction site analysis. A shuttle vector that replicates in Escherichia coli and Alteromonas sp. strain A28 was constructed by fusing pAS28 and E. coli vector pCRIIc. The 16-kbp chimeric plasmid, designated pASS1, had the ability to transform strain A28 at a frequency of 10(6) transformants per microg of DNA. Deletion analysis of pASS1 showed that the 4.7-kb EcoRI-HindIII region of pAS28 was essential for plasmid maintenance in strain A28. This EcoRI-HindIII fragment contained an open reading frame which appeared to encode a 708-amino-acid protein.
Animals↗
[High-dose chemotherapy with autologous peripheral blood stem cell transfusion in the treatment of advanced testis cancer].
Four patients with advanced testis cancer were treated by high-dose chemotherapy supporting by autologous peripheral blood stem cell transplantation. High-dose chemotherapy (carboplatin 250 mg/m2 or nedaplatin 200 mg/m2, etoposide 1,500 mg/m2, ifosphamide 7.5 g/m2 was given and peripheral blood stem cell transfusion was performed 72 hours after the last dose of chemotherapy. High-dose chemotherapy. was given followed by 1 or 2 cycles of pre high-dose therapy consisting of cisplatin 100 mg/m2 or carboplatin 500 mg/m2, etoposide 450 mg/m2, ifosphamide 6 g/m2. All 4 patients were evaluable. Three patients obtained a complete response and one showed a partial response. The partial responder was given RPLND. The RPLND specimen showed necrotic tissue.
Adult↗
Guanosine tetra- and pentaphosphate promote accumulation of inorganic polyphosphate in Escherichia coli.
High levels of guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), generated in response to amino acid starvation in Escherichia coli, lead to massive accumulations of inorganic polyphosphate (polyP). Inasmuch as the activities of the principal enzymes that synthesize and degrade polyP fluctuate only slightly, the polyP accumulation can be attributed to a singular and profound inhibition by pppGpp and/or ppGpp of the hydrolytic breakdown of polyP by exopolyphosphatase, thereby blocking the dynamic turnover of polyP. The Ki values of 10 microM for pppGpp and 200 microM for ppGpp are far below the concentrations of these nucleotides in nutritionally stressed cells. In the complex metabolic network of pppGpp and ppGpp, the greater inhibitory effect of pppGpp (compared with ppGpp) leading to the accumulation of polyP, may have some significance in the relative roles played by these regulatory compounds.
Acid Anhydride Hydrolases↗
Polyphosphate kinase as a nucleoside diphosphate kinase in Escherichia coli and Pseudomonas aeruginosa.
Generation of a wide variety of nucleoside (and deoxynucleoside) triphosphates (NTPs) from their cognate nucleoside diphosphates (NDPs) is of critical importance in virtually every aspect of cellular life. Their function is fulfilled largely by the ubiquitous and potent nucleoside diphosphate kinase (NDK), most commonly using ATP as the donor. Considerable interest is attached to the consequence to a cell in which the NDK activity becomes deficient or over-abundant. We have discovered an additional and possibly auxiliary NDK-like activity in the capacity of polyphosphate kinase (PPK) to use inorganic polyphosphate as the donor in place of ATP, thereby converting GDP and other NDPs to NTPs. This reaction was observed with the PPK activity present in crude membrane fractions from Escherichia coli and Pseudomonas aeruginosa as well as with the purified PPK from E. coli; the activity was absent from the membrane fractions obtained from E. coli mutants lacking the ppk gene. The order of substrate specificity for PPK was: ADP > GDP > UDP, CDP; activity with ADP was 2-60 times greater than with GDP, depending on the reaction condition. Although the transfer of a phosphate from polyphosphate to GDP by PPK to produce GTP was the predominant reaction, the enzyme also transferred a pyrophosphate group to GDP to form the linear guanosine 5' tetraphosphate.
Cell Membrane↗
Interleukin-4 inhibits the gene expression and biosyntheis of cytosolic phospholipase A2 in lipopolysaccharide stimulated U937 macrophage cell line and freshly prepared adherent rheumatoid synovial cells.
We recently reported that interleukin-4 (IL-4) inhibited prostanoid synthesis through inhibiting cyclooxygenase 2 biosynthesis. In the present study, we examined the effect of IL-4 on the expression of cytosolic phospholipase A2 (cPLA2). The amounts of protein and mRNA of cPLA2 were determined by western blotting and reverse transcription polymerase chain reaction (RT-PCR), respectively. Although interleukin-1alpha (IL-1alpha) and tumor necrosis factor alpha (TNFalpha) had little effect on the biosynthesis of cPLA2 in phorbol myristate acetate (PMA)-differentiated U937 cells, lipopolysaccharide (LPS) increased the protein level of cPLA2 in a dose-dependent manner. IL-4 inhibited the increased synthesis of cPLA2 at the mRNA level. In addition, IL-4 inhibited the biosynthesis of cPLA2 in untreated or LPS treated freshly prepared rheumatoid synovial cells at the mRNA level. These findings suggest that IL-4 inhibits prostanoid synthesis through inhibiting the expression of both cPLA2 and cyclooxygenase 2.
Arthritis, Rheumatoid↗
Effect of oral protease inhibitor administration on gallbladder motility in patients with mild chronic pancreatitis.
Oral administration of a protease inhibitor (camostat) induces pancreatic hypersecretion via hormonal and neural systems in humans. Camostat may also affect gallbladder motility via these systems. The aim of this study was to evaluate the effect of camostat on gallbladder function. Gallbladder emptying in response to caerulein administration and to egg yolk ingestion was examined ultrasonographically in 15 patients with mild chronic pancreatitis before and after 6 months of camostat treatment, and in 10 control subjects. The plasma cholecystokinin concentration after yolk ingestion was measured by radioimmunoassay. Fasting gallbladder volume and contractile function, whether stimulated by caerulein or yolk, did not differ between pancreatitis patients before camostat treatment and controls. Plasma cholecystokinin levels, basal and yolk-stimulated, did not differ between nontreated pancreatitis patients and control subjects. Fasting volume had decreased significantly by 1, 3, and 6 months of camostat treatment, while contractile function was not affected. Camostat did not influence plasma cholecystokinin levels. Oral administration of a protease inhibitor appears to decrease fasting gallbladder volume via a mechanism other than cholecystokinin release.
Administration, Oral↗
Two types of mucin-producing cystic tumors of the pancreas: diagnosis and treatment.
BACKGROUND: This study focuses on clinicopathologic, imaging, and prognostic differences between two types of mucin-producing cystic tumors of the pancreas, with the aim of appropriate management of these tumors. METHODS: Forty-six patients with mucin-producing cystic tumors underwent operation. The types of tumors were as follows: mucinous cystic neoplasm, adenoma (6) and adenocarcinoma (12); intraductal papillary tumor, adenoma (10) and adenocarcinoma (18). RESULTS: Gender, age, symptoms, signs, tumor location and size, and the presence or absence of communication with the pancreatic duct differed between the two types. Mucinous cystadenocarcinomas showed deep invasion more often than intraductal papillary adenocarcinomas. Lymph node involvement was seen in 58% of mucinous cystadenocarcinomas but in only 22% of intraductal papillary adenocarcinomas. Tumors with mural nodules tended to show deep invasion and nodal metastasis. All four intraductal papillary tumors smaller than 3 cm without mural nodules were adenomas. Imaging studies allowed accurate differentiation between the two types but not between adenomas and adenocarcinomas. Five-year survival rates for patients with adenomas, mucinous cystadenocarcinomas, and intraductal papillary adenocarcinomas were 100%, 33%, and 81%, respectively. CONCLUSIONS: Mucinous cystic neoplasm necessitates complete tumor excision with wide dissection of lymph nodes including paraaortic nodes. Intraductal papillary tumor requires only peripancreatic node dissection; for tumors smaller than 3 cm without mural nodules, node dissection may be unnecessary.
Adenocarcinoma↗