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.

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.

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.

Characteristics and treatment of mucin-producing tumor of the pancreas

BACKGROUND/AIMS

There has been no thorough clinicopathological analysis of a large number of cases with mucin-producing tumor of the pancreas. The aim of this study was to investigate the clinicopathological features of and therapeutic strategy for this ailment.

METHODOLOGY

Two hundred and fifty-nine cases of mucin-producing tumor of the pancreas were analyzed clinicopathologically.

RESULTS

Mucin-producing tumor of the pancreas was found in 177 males and 82 females (M:F=2.2:1). The mean age was 65.5 years. Jaundice, diabetes mellitus and a past history of pancreatitis were found in 15-19% of the cases. The tumor was most frequently (62%) found in the head of the pancreas. Pathologically, hyperplasia or adenoma was found in 58 cases, and adenocarcinoma in 160 cases. Five-year survival rate by the Kaplan-Meier method was 82.6% in all of the cases, and the post-operative survival curve was much better in cases with this type of carcinoma than in cases with ordinary pancreatic duct cell carcinoma (5-year survival rate: 17.3%). Organ-function preserving procedures, such as duodenum preserving subtotal resection of the head of the pancreas or spleen preserving distal pancreatectomy, might be recommended for this disease without infiltration.

CONCLUSIONS

Mucin-producing tumor has unique clinicopathological characteristics, such as the dilated main pancreatic duct or branches, dilatation of the orifice of the papilla of Vater, or a good prognosis. Organ-function preserving procedures should be recommended in some cases with this ailment.

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.

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.

[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.

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.

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.

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.

[Laboratory diagnosis of auto-immune hemolytic anemia: characteristics of the manual direct test of Polybrene]

The direct manual Polybrene test (DPT) and the direct antiglobulin tests (DAT) were employed to detect antibody sensitizing red blood cell (RCB) in patients with clinical and laboratorial findings of autoimmune hemolytic anemia (AIHA).

PURPOSE

To compare the sensitivity and specificity of DPT and DAT in the diagnosis of AIHA.

METHODS

Eighteen consecutive patients with diagnosis of AIHA were evaluated. The control group consisted of 20 normal volunteers blood donors and 20 patients with sickle cell anemia. All patients and controls were submitted to DPT and DAT. All DAT positive samples were further tested using monospecific reagents (anti-IgG heavy chain and anti-C3d). Positive samples for either DPT or DAT were evaluated by eluate technique using. The dichloromethane (DCM).

RESULTS

The DAT was positive in 14 patients and negative in 4 subjects, while the DPT was positive in 17 patients and negative in 1 individual who had a positive DAT owing to complement (C3d). All positive eluates performed with DCM showed RBC autoantibodies with presumed "anti-Rh" specificity. The sensitivity rate of the DPT (94%) was significantly (p < 0.05) higher than the sensitivity rate of DAT (78%) to determine whether IgG was bound in vivo, but no difference was found regarding the specificity of the two tests.

CONCLUSION

1) The DPT is more sensitive than the DAT in detecting IgG autoantibody on the RBCs of patients with AIHA; 2) because of its simplicity and rapidity, the DPT is a useful additional screening test for the investigation of Coombs-negative AIHA.

Isolation and characterization of Enterobacter cloacae mutants which are defective in chemotaxis toward inorganic phosphate

Enterobacter cloacae IFO3320 is attracted to Pi when cells are starved for Pi. Two Tn1737KH-induced mutants, which were constitutive for alkaline phosphatase, failed to exhibit Pi taxis even under conditions of Pi limitation. Both of the mutant strains exhibited normal chemotactic responses to peptone, suggesting that they are specifically defective in Pi taxis. Cloning and sequence analysis showed that the TN1737KH insertions were located in either the pstA or pstB genes which encode the channel-forming proteins of the Pi-specific transport (Pst) system in E. cloacae. These results suggest that the E. cloacae Pst system is required for Pi chemoreception.

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.

Bile duct carcinoma without jaundice: clues to early diagnosis

BACKGROUND/AIMS

Most bile duct carcinomas are diagnosed at an advanced stage, after the appearance of jaundice. The features of bile duct carcinomas without jaundice were analyzed with the aim of allowing early diagnosis in such cases.

METHODOLOGY

Clinicopathological features, images and surgical outcomes were compared between 18 non-jaundiced and 85 jaundiced patients with extrahepatic bile duct carcinoma.

RESULTS

Among the non-jaundiced patients, 13 were symptomatic. Abnormalities on hepatic function and tumor marker tests were seen in 56% and 44%, respectively. In all 18 cases, ultrasonography demonstrated biliary abnormalities including masses (9 patients) and strictures (5 patients). The diagnosis was confirmed histologically by transpapillary bile duct biopsy in eight of 10 non-jaundiced patients. The non-jaundiced patients (83%) had a higher rate of resectability than jaundiced patients (58%). Pathological findings of resected specimens showed no significant differences between the two groups. The non-jaundiced group had a significantly higher survival rate than the jaundiced group: 50% vs. 22% at 5 years.

CONCLUSION

For early diagnosis of bile duct carcinomas not associated with jaundice, detailed ultrasonographic examination is useful, and subtle changes indicate a need for direct cholangiography. Non-jaundiced cases have the potential for curative resection.

HIV-antibody detection in vitreous humor and serum by enzyme immunosorbent assay and particle agglutination test

PURPOSE

To compare enzyme immunosorbent assay (EIA) and the particle agglutination (PA) test for the detection of antibodies to the human immunodeficiency virus (HIV) in cadaveric vitreous humor and serum.

METHODS

Seventeen cadavers presenting pathologic signs of acquired immunodeficiency syndrome (AIDS) at autopsy and 33 without AIDS signs were evaluated. Consistency (k) and significance (p) between the diagnostic tests were established.

RESULTS

The right and left eyes of each of 48 bilaterally tested cadavers presented identical diagnostic results in all laboratory tests. All tests were positive for antibodies in the AIDS cadavers except for two EIA-negative vitreous results. Three autopsy-negative cadavers showed by both EIA and PA testing positive results in serum and negative in vitreous. Two of them showed a serum-positive Western blot.

CONCLUSION

Serum EIA anti-HIV antibody detection test is the current gold standard for evaluating corneal donor material. Neither the PA test nor EIA should be used for vitreous testing because of their low sensitivity.

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.

[Discovery and development of a novel immunosuppressant, tacrolimus hydrate]

Tacrolimus hydrate (FK506), a novel 23-membered macrolide, is an immunosuppressant isolated from Streptomyces tsukubaensis using extensive screening of fermentation products to identify a compound inhibiting the mixed lymphocyte reaction (MLR). The in vitro and in vivo immunosuppressive activities of FK506 were found to be more potent than those of cyclosporine (CyA). The superior immunosuppression with FK506 treatment was also confirmed in the skin allograft model in rats and liver transplantation in dogs. Clinical studies were initiated by Prof. Starzl at the University of Pittsburgh in 1989, and he demonstrated that FK506 surpassed CyA in the incidence of graft survival and the frequency of graft rejection. Multicenter randomized clinical studies, comparing FK506 to CyA corroborated the efficacy of FK506 on the survival of patients and of grafts, and especially on the appearance of severe refractory graft rejection. FK506 was marketed in 1993 in Japan, and was followed in 1994 in the U.S.A., U.K. and Germany. The mechanism of action of this compound was clarified by the endeavors of Prof. Schreiber, who demonstrated the existence of a binding protein for FK506 called FKBP, similar to cyclophilin for CyA. The FK506/FKBP complex binds with calcineurin, a serine/threonine phosphatase to inhibit the translocation of NFAT into the nucleus, resulting in inhibition of transcription of IL-2 mRNA. FK506 displays potent immunosuppressant activity, and contributes not only to the progress of transplantation therapy for clinical studies, but also to the clarification of signal transduction in T cell activation for basic science.

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.

Distribution of a synthetic protease inhibitor in rat pancreatic acini after supramaximal secretagogue stimulation

Protease inhibitors may have a beneficial effect in acute pancreatitis. The effects of E3123, a new low molecular weight protease inhibitor, on the ultrastructure of isolated pancreatic acini were examined using transmission electron microscopy. Acini supramaximally stimulated with cerulein (10(-8) M) formed large cytoplasmic vacuoles similar to those generated in the cerulein-induced in vivo model of pancreatitis. Pretreatment of isolated acini with E3123 significantly reduced the size and number of vacuoles associated with cerulein treatment. The distribution of 3H-E3123 in acinar cells was examined using a pulse-chase protocol and electron microscopic autoradiography. Cellular levels of 3H-E3123 increased about 30-fold in acinar cells treated with cerulein (10(-8) M) compared to unstimulated controls. In cerulein-treated acini examined after a 5-min chase, 47.4% of the autoradiographic grains were associated with the rough endoplasmic reticulum and 13.2% were associated with zymogen granules. After 30 min of incubation, the grains associated with the endoplasmic reticulum decreased to 18.5% but increased to 26.3% over zymogen granules. Thus, E3123 is taken up by the acinar cell and follows a cellular itinerary similar to that of newly synthesized secretory proteins. One potential conclusion from these studies is that the ability of E3123 to reduce the formation of vacuoles in supra-maximally stimulated acini may be due to its inhibition of proteases within the secretory pathway.

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.

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.

Pancreatic exocrine function during acute exacerbation in WBN/Kob rats with spontaneous chronic pancreatitis

CONCLUSION

Pancreatic exocrine hypofunction is markedly deteriorated during acute exacerbation in a rat model with chronic pancreatitis.

BACKGROUND

Little is known about pancreatic exocrine function during acute exacerbation in patients with chronic pancreatitis. We investigated changes in pancreatic exocrine function after inducing acute pancreatitis in an animal model of spontaneous chronic pancreatitis.

METHODS

WBN/Kob rats with chronic pancreatitis sequentially underwent pancreatic exocrine function test 1-6 d after surgical preparation with external pancreatic fistula. We induced acute pancreatitis in another WBN/Kob rats by i.v. administration of cerulein at a rate of 10 micrograms/kg/h for 4 h 4 d after surgical preparation. Pancreatic exocrine function test was undertaken in a conscious state 1 d before and after cerulein administration.

RESULTS

In WBN/Kob rats not given cerulein, pancreatic exocrine function remained almost constant at 3-6 d after surgery. Marked hyperamylasemia developed immediately after cerulein administration. After its administration, the pancreas microscopically showed prominent interstitial edema and intracellular vacuolization of acinar cells in addition to the finding of pre-existing chronic pancreatitis. Basal and cholecystokinin-stimulated flow rate, bicarbonate output, and protein output, which were substantially impaired 1 d before cerulein administration, were further reduced 1 d after its administration.

Effect of oral administration of protease inhibitor on pancreatic exocrine function in WBN/Kob rats with chronic pancreatitis

The effect of oral administration of protease inhibitor (camostat) on pancreatic morphology and exocrine function (conscious rat model) was investigated using WBN/Kob rats with spontaneous chronic pancreatitis. In nontreated WBN/Kob rats (2-12 months of age), pancreatic fibrosis and parenchymal destruction compatible with human chronic pancreatitis appeared at 3 months and advanced with each month. Pancreatic secretion was markedly impaired at all ages. In WBN/Kob rats fed diets containing camostat (from 2-3 or 4-5 months of age), the pancreas was hypertrophic and did not show any histological appearances compatible with chronic pancreatitis, and moreover, exocrine function was thoroughly restored with increased plasma cholecystokinin concentrations. Oral administration of protease inhibitor has both preventive and therapeutic effects on pancreatic lesions and dysfunction in an animal model of chronic pancreatitis, probably via endogenous cholecystokinin release.