A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean

The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.

Diagnosis and treatment of obscure gastrointestinal bleeding using combined capsule endoscopy and double balloon endoscopy: 1-year follow-up study

BACKGROUND AND STUDY AIMS

Several studies have shown the value of capsule endoscopy and double balloon endoscopy (DBE) in small-intestinal bleeding. The purpose of this study was to evaluate the impact of capsule endoscopy results on subsequent DBE examination, and the 1-year clinical outcome of this combined approach in patients with obscure gastrointestinal bleeding (OGIB).

PATIENTS AND METHODS

A total of 45 consecutive patients with OGIB underwent capsule endoscopy. Patients with positive capsule endoscopy results underwent DBE for biopsy or therapy, and those with negative results underwent further assessment for possible diagnostic misses on capsule endoscopy. Tumors, ulcerations, and vascular lesions were considered as sources of bleeding. Diagnoses of OGIB lesions and clinical outcome were assessed 1 year after these examinations.

RESULTS

Responsible lesions were found in 22 patients (49 %): 19 lesions in 18/45 patients (40 %) undergoing capsule endoscopy, and 18/36 patients (50 %) undergoing subsequent DBE. In all, 10 tumors, nine vascular lesions, and four ulcerations were found. In two patients, vascular lesions were only later diagnosed by conventional methods (4 %). Capsule endoscopy results guided our choice of the proper DBE model for successful therapeutic intervention in five patients. Re-bleeding rates were low during 1-year follow-up of the entire group (mean follow-up, 18.8 months): 5 % in cases with positive diagnoses on capsule endoscopy and/or DBE, and 12 % in negative cases.

CONCLUSIONS

A combined approach using capsule endoscopy followed by DBE proves valuable in the diagnosis and treatment of patients with OGIB, leaves a low rate of undiagnosed bleeding sources, and has a good long-term outcome.

Chemopreventive effect of celecoxib in gastric cancer

COX (cyclooxygenase) is one of the key enzymes involved in the synthesis of a variety of prostaglandins (PGs), some of which have been strongly linked to inflammation. One of its two well-known isoforms, COX-2, is an inducible enzyme whose induction and expression is dynamically regulated by growth factors, mitogens, and tumor promoters. Several animal and clinical studies have reported the chemopreventive effect of celecoxib, a selective COX-2 inhibitor; and in particular, a few studies have shown that celecoxib prevents the development of gastric cancer. Administration of celecoxib also showed increases in cardiovascular risk and disruption of renal physiology. Therefore, studies hoping to clarify how selective COX-2 inhibitors modulate gastric cancer must keep in mind that coxibs have also been linked to serious cardiovascular events and disruption of renal physiology.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma

BACKGROUND AND AIMS

Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria.

METHODS

Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E(2) and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood.

RESULTS

MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1alpha and MIP-1beta, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE(2) and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE(2) and VEGF release in macrophages. Addition of exogenous PGE(2) reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation.

CONCLUSIONS

MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Preventive therapy for non-steroidal anti-inflammatory drug-induced ulcers in Japanese patients with rheumatoid arthritis: the current situation and a prospective controlled-study of the preventive effects of lansoprazole or famotidine

BACKGROUND

There is a lack of evidence for the efficacy of preventive medications for peptic ulcers (PUs) among long-term users of non-steroidal anti-inflammatory drugs (NSAIDs) in Japan.

AIM

To estimate the preventive effect by normal dose, not high-dose histamine-H2 receptor antagonists (H2RA) for NSAID-induced ulcers.

METHODS

We designed two different studies to assess the efficacy of anti-ulcer agents in rheumatoid arthritis (RA) in patients treated over a long term with NSAIDs. An investigative survey divided patients into those not taking anti-ulcer agents (non-medication group); those taking mucosal protective agents (mucosal protectant group), H2RA (H2RA group), proton pump inhibitors (PPI group), or a prostaglandin E1 analog (PG) (PG group). The second study compared prospectively the preventive effects of either famotidine 20 mg bd (famotidine group) or lansoprazole 15 mg daily (lansoprazole group) in patients with PU scars.

RESULTS

The prevalence of PU in the H2RA group was significantly lower compared to the mucosal protectant group (P < 0.05), and the mucosal protectant group was not significantly different to the non-medication group. The prospective study revealed that the PU onset rate of the famotidine group was 8% (1/13), and lansoprazole group was 15% (2/13), indicating no significant differences between the two.

CONCLUSIONS

In Japan, normal-dose H2RA is expected to be a new PU preventive treatment strategy in patients requiring long-term NSAID therapy.

Implications of corpus gastritis, atrophy and cyclooxygenase in the development of gastric erosions after curing Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication decreases recurrence of peptic ulcers with marked improvement in histological inflammation, but gastric mucosal injuries may be developed even after eradication.

PURPOSE

To investigate the mechanisms responsible for the development of gastric erosions after eradication, we analysed the relationship between clinicopathological risk factors and the occurrence of gastric erosion after curing H. pylori infection.

PATIENTS

Sixty patients underwent endoscopy before, and 3, 6 and 12 months after the completion of H. pylori eradication.

METHODS

Risk factors associated with the development of gastric erosions after eradication were assessed by multivariate analysis, and cyclooxygenase-1 and -2 immunoreactivity was histologically examined in the gastric mucosa before and after eradication.

RESULTS

The cumulative prevalence of gastric erosions after H. pylori eradication was 38.3% within 1 year. Using multivariate analysis, corpus gastritis scores (inflammation score+activity score), corpus atrophy scores and an age of more than 50 years were found to be independent factors associated with the development of gastric erosion after eradication with odds ratios of 7.39, 0.13 and 5.00, respectively. Cyclooxygenase-2 immunoreactivity of the corpus was decreased for the non-erosion group after eradication, but not for the erosion group.

CONCLUSIONS

Severe gastritis or less severe atrophy in oxyntic glands but not in pyloric glands before eradication may be involved in the development of gastric erosions after curing H. pylori infection.

Development of colonic neoplasia in p53 deficient mice with experimental colitis induced by dextran sulphate sodium

BACKGROUND

Several animal models for human ulcerative colitis (UC) associated neoplasia have been reported. However, most neoplasias developed in these models have morphological and genetic characteristics different from UC associated neoplasia.

AIMS

To establish a new colitis associated neoplasia model in p53 deficient mice by treatment with dextran sulphate sodium (DSS).

METHODS

DSS colitis was induced in homozygous p53 deficient mice (p53(-/-)-DSS), heterozygous p53 deficient mice (p53(+/-)-DSS) and wild-type mice (p53+/+-DSS) by treatment with 4% DSS. Numbers of developed neoplasias were compared among the experimental groups, and macroscopic and microscopic features of the neoplasias were analysed. Furthermore, K-ras mutation and beta-catenin expression were assessed.

RESULTS

p53(-/-)-DSS mice showed 100% incidence of neoplasias whereas the incidences in p53(+/-)-DSS and p53+/+-DSS mice were 46.2% and 13.3%, respectively. No neoplasias were observed in the control groups. The mean numbers of total neoplasias per mouse were 5.0 (p53(-/-)-DSS), 0.62 (p53(+/-)-DSS), and 0.2 (p53+/+-DSS). The number of neoplasias per mouse in the p53(-/-)-DSS group was significantly higher than that in the other DSS groups. The incidences of superficial type neoplasias were 91.7% in p53(-/-)-DSS mice, 75.0% in p53(+/-)-DSS mice, and 33.3% in p53+/+-DSS mice. The K-ras mutation was not detected in any of the neoplasias tested. Translocation of beta-catenin from the cell membrane to the cytoplasm or nucleus was observed in 19 of 23 (82.6%) neoplasias.

CONCLUSIONS

The p53(-/-)-DSS mice is an excellent animal model of UC associated neoplasia because the morphological features and molecular genetics are similar to those of UC associated neoplasia. Therefore, this model will contribute to the analysis of tumorigenesis related to human UC associated neoplasia and the development of chemopreventive agents.

Thrombopoietin stimulates ex vivo expansion of mature neutrophils in the early stages of differentiation

We examined the effects of thrombopoietin (TPO) in combination with stem cell factor (SCF), interleukin-3 (IL-3), and granulocyte colony-stimulating factor (G-CSF) on the proliferation and differentiation of human neutrophils. Purified CD34(+) hematopoietic progenitor cells were cultivated with SCF, IL-3, and G-CSF for 7 days (early phase), and thereafter nonadherent cells were further cultivated for 9 days with G-CSF alone (late phase). A large number of highly selected neutrophils (>95%) was obtained on day 16. We compared the expansion capacity in the presence or absence of TPO in each culture phase. The significantly larger number of neutrophils was obtained in the presence of TPO in the early culture phase. The number of expanded cells plateaued at day 16. Ultimately, a 550-fold increase in the number of neutrophils was achieved. These neutrophils gained the ability to respond effectively with chemotaxis and superoxide release, and were appropriately primed by G-CSF, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and IL-1beta for enhanced release of O(2)(-). The responsiveness of these cells was identical to that of peripheral blood neutrophils. However, TPO did not accelerate the maturation of neutrophils supported by G-CSF in the late phase of culture. Furthermore, priming effects and triggering effects of TPO on the production of superoxide metabolites from peripheral blood neutrophils were not observed. These results suggest that TPO regulates the proliferation and differentiation of neutrophils in the early stages, but not the late stages, of differentiation.

Monocyte chemoattractant protein 1 (MCP-1) released from Helicobacter pylori stimulated gastric epithelial cells induces cyclooxygenase 2 expression and activation in T cells

BACKGROUND

and aims: To clarify the interaction between gastric epithelial and mucosal T cells, we examined the role of cytokines released from epithelial cells in response to Helicobacter pylori water extract protein (HPWEP) in regulating T cell cyclooxygenase 2 (COX-2) expression and activation.

METHODS

Media from MKN-28 cells incubated with HPWEP for 48 hours were added to Jurkat T cells and human peripheral T cells. C-C and CXC chemokine concentrations in MKN-28 cell media, and COX-2 expression, interferon gamma (IFN-gamma), and interleukin (IL)-4 secretions in T cells were determined by western blot analysis and ELISA methods. Distributions of COX-2 positive T cells and monocyte chemoattractant protein 1 (MCP-1) in tissue specimens with H pylori associated gastritis were determined as single or double labelling by immunohistochemistry.

RESULTS

MCP-1, IL-7, IL-8, and RANTES were detected in media from MKN-28 cells incubated with HPWEP. Media as a whole, and MCP-1 alone, stimulated COX-2 expression and peripheral T cell proliferation. Anti-MCP-1 antibody inhibited media stimulated COX-2 mRNA expression in Jurkat T cells. Media stimulated IFN-gamma but not IL-4 secretion from peripheral T cells, while MCP-1 stimulated IL-4 but not IFN-gamma secretion. Both stimulated cytokine release, and peripheral T cell proliferation was partially inhibited by NS-398, a specific COX-2 inhibitor. In mucosa with gastritis, COX-2 was expressed in T cells and MCP-1 was localised mainly in epithelial and mononuclear cells. MCP-1 levels and the intensity of COX-2 expression in tissue samples were closely related.

CONCLUSIONS

Cytokines such as MCP-1, released from gastric epithelial cells in response to HPWEP, seem to modulate T cell immune responses, at least in part via COX-2 expression.

Influence of alcohol consumption on the association between serum lipids and colorectal adenomas

BACKGROUND

There have been no reports that low serum cholesterol levels increase the risk of colorectal adenoma, although many studies have shown that they do increase the risk of colorectal cancer. Alcohol intake, which is associated with a risk of colorectal adenomas, and serum cholesterol levels are closely related. The purpose of this study was to evaluate the influence of alcohol consumption on the association between serum cholesterol levels and colorectal adenoma.

METHODS

The subjects were 1,349 male patients who underwent both barium enema examination and total colonoscopy. They answered a questionnaire regarding their alcohol consumption history, and their blood samples were analysed. The subjects were divided into three groups: those with no tumour (with neither adenoma nor adenocarcinoma), those with adenoma and those with adenocarcinoma. Among the groups, the serum total cholesterol and triglyceride levels were compared in all the patients, in the patients who did not drink daily and in the patients who did.

RESULTS

In all the patients, the serum cholesterol and triglyceride levels did not differ between the patients with and those without adenoma. In the daily drinkers, the serum cholesterol and triglyceride levels were significantly lower in patients with adenoma than in those without.

CONCLUSIONS

Significantly lower levels of serum cholesterol and triglycerides were found in daily drinkers with adenoma than in those without.

Inhibition of Helicobacter pylori-induced cyclo-oxygenase-2 aggravates NSAID-caused gastric damage in Mongolian gerbils

BACKGROUND

The effect of Helicobacter pylori infection on non-steroidal anti-inflammatory drug-induced gastric mucosal injury is controversial.

AIM

To examine the effect of the interaction between H. pylori and non-steroidal anti-inflammatory drugs on gastric mucosal injury.

METHODS

Mongolian gerbils infected with H. pylori were treated with indometacin at 8 mg/kg for 2 days or 7 days. Mucosal damage was assessed by macroscopic and histological examination, and myeloperoxidase activity was measured as an index of neutrophil infiltration. The expression levels of cyclo-oxygenase proteins were determined by Western blot analysis and cyclo-oxygenase activity.

RESULTS

A 2-day course of indometacin did not cause an increase in gastric damage in H. pylori-infected Mongolian gerbils compared to uninfected gerbils, while a 7-day course of indometacin caused additive gastric damage in H. pylori-infected animals. H. pylori infection induced cyclo-oxygenase-2 expression in the stomach. Treatment with indometacin for 2 days did not significantly affect cyclo-oxygenase activity in H. pylori-infected animals, while treatment for 7 days inhibited both cyclo-oxygenase-1 and cyclo-oxygenase-2 activities. Pre-treatment with a selective cyclo-oxygenase-2 inhibitor aggravated mucosal injury in H. pylori-infected animals treated or not treated with indometacin for 2 days.

CONCLUSIONS

Our results suggest that cyclo-oxygenase-2 protein induced by H. pylori infection may be involved in the defence of the gastric mucosa against damage caused by non-steroidal anti-inflammatory drugs. Therefore, inhibition of cyclo-oxygenase-2 activity may enhance non-steroidal anti-inflammatory drug-caused gastric damage in H. pylori-infected animals.

Effect of acid suppression therapy on development of gastric erosions after cure of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication markedly improves histological inflammation and decreases peptic ulcer recurrence, but little is known about the subsequent development of gastric mucosal injury.

AIM

To investigate whether acid suppression treatment after eradication influences the development of gastric erosions.

METHODS

Eighty-one patients (gastritis or peptic ulcer) after successful H. pylori eradication were divided into two groups: 40 received an H2-blocker for 6 months (H2-blocker-positive) and 41 received no treatment (H2-blocker-negative). Endoscopy was performed before, and at 3 and 6 months after completion of eradication.

RESULTS

Cumulative prevalence of gastric erosions in the H2-blocker-positive group was significantly lower than in the H2-blocker-negative group, 25% vs. 42%, respectively. In the H2-blocker-negative group but not the H2-blocker-positive group, the cumulative prevalence of gastric erosions after eradication was higher in patients with less severe corpus atrophy or more severe corpus gastritis.

CONCLUSIONS

Development of gastric erosions after H. pylori eradication may be controlled by acid suppression treatment. Less severe atrophy or more severe gastritis in oxyntic glands before eradication may be involved in the development of gastric erosions. These results support the idea that recovery of acid secretion may be one of factors for development of gastric mucosal erosions after successful eradication.

Selective activation of p38 mitogen-activated protein kinase cascade in human neutrophils stimulated by IL-1beta

We investigated activation of mitogen-activated protein kinase (MAPK) subtype cascades in human neutrophils stimulated by IL-1beta. IL-1beta induced phosphorylation and activation of p38 MAPK and phosphorylation of MAPK kinase-3/6 (MKK3/6). Maximal activation of p38 MAPK was obtained by stimulation of cells with 300 U/ml IL-1beta for 10 min. Extracellular signal-regulated kinase (ERK) was faintly phosphorylated and c-Jun N-terminal kinase (JNK) was not phosphorylated by IL-1beta. IL-1beta primed neutrophils for enhanced release of superoxide (O(2)(-)) stimulated by FMLP in parallel with increased phosphorylation of p38 MAPK. IL-1beta also induced O(2)(-) release and up-regulation of CD11b and CD15, and both responses were inhibited by SB203580 (p38 MAPK inhibitor), suggesting that p38 MAPK activation mediates IL-1beta-induced O(2)(-) release and up-regulation of CD11b and CD15. Combined stimulation of neutrophils with IL-1beta and G-CSF, a selective activator of the ERK cascade, resulted in the additive effects when the priming effect and phosphorylation of p38 MAPK and ERK were assessed. IL-1beta induced phosphorylation of ERK and JNK as well as p38 MAPK in human endothelial cells. These findings suggest that 1) in human neutrophils the MKK3/6-p38 MAPK cascade is selectively activated by IL-1beta and activation of this cascade mediates IL-1beta-induced O(2)(-) release and up-regulation of CD11b and CD15, and 2) the IL-1R-p38 MAPK pathway and the G-CSF receptor-ERK pathway work independently for activation of neutrophils.

Nodal gamma/delta T cell lymphoma in complete remission following allogeneic bone marrow transplantation from an HLA-matched unrelated donor

Gamma/delta T cell lymphoma is very rare, and usually occurs as an extranodal tumor. We describe the case of a 16-year-old Japanese man with an unusual nodal gamma/delta T cell lymphoma with generalized lymphadenopathy and bone marrow involvement. No tumor involvement was observed in the liver, spleen, or nasal cavity. Examination for surface antigens on lymphoma cells revealed a unique phenotype, positive for CD3 and T cell receptor (TCR) gamma/delta, but negative for CD2. Genotypic analysis revealed the tumor to be of monoclonal origin and characterized by TCR gamma-chain gene rearrangement, but there was no rearrangement of the TCR beta-chain gene. Our patient's tumor responded to combination chemotherapy and subsequent allogeneic bone marrow transplantation from an HLA-matched unrelated donor. He has remained well and free of disease for 35 months.

Cleavage of mitogen-activated protein kinases in human neutrophils undergoing apoptosis: role in decreased responsiveness to inflammatory cytokines

Extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) are major signaling molecules activated in human neutrophils stimulated by cytokines. Both molecules were cleaved at the N-terminal portion in neutrophils undergoing apoptosis induced by in vitro culture alone or treatment with TNF and/or cycloheximide. The cleavage of both molecules was inhibited by G-CSF and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, a caspase inhibitor, both of which can inhibit neutrophil apoptosis. In a cell-free system, ERK and p38 MAPK were not cleaved by recombinant caspase-3 or caspase-8 while gelsolin was cleaved by caspase-3 under the same condition. The cleavage of both molecules appears to be specific to mature neutrophils, since it was not detected in immature cells (HL-60 and Jurkat) undergoing apoptosis, indicating that proteases responsible for the cleavage of both molecules may develop during differentiation into mature neutrophils. Concomitant with the cleavage of ERK and p38 MAPK, GM-CSF- and TNF-induced superoxide release, adherence, and phosphorylation of ERK and p38 MAPK were decreased in neutrophils undergoing apoptosis. In addition, GM-CSF- and TNF-induced superoxide release and adherence were inhibited by PD98059 MAPK/ERK kinase inhibitor) as well as SB203580 (p38 MAPK inhibitor), suggesting possible involvement of ERK and p38 MAPK in superoxide release and adherence induced by these cytokines. These findings indicate that ERK and p38 MAPK are cleaved and degraded in neutrophils undergoing apoptosis in a caspase-dependent manner and the cleavage of both molecules may be partly responsible for decreased functional responsiveness to inflammatory cytokines.

Aging increases, and duodenal ulcer reduces the risk for intestinal metaplasia of the gastric corpus in Japanese patients with dyspepsia

BACKGROUND AND AIMS

The classification of gastritis by using the revised Sydney system suggests that there are two types of Helicobacter pylori-related gastritis. The aim of the present study was to examine the risk factors that might be involved in the presence of either atrophic gastritis or intestinal metaplasia of the gastric corpus of Japanese patients.

METHODS

Biopsy samples were obtained from the gastric corpus in 154 patients with dyspepsia, and the degree of atrophy or intestinal metaplasia was determined histologically. The correlation between several variables and presence of atrophy or intestinal metaplasia was evaluated by using multivariate analysis.

RESULTS

Among the 11 variables, which included age, peptic ulcer diseases and H. pylori infection, H. pylori infection was the major risk factor associated with the presence of atrophic gastritis or intestinal metaplasia of the gastric corpus. In contrast, duodenal ulcer (DU) disease reduced the risk of contracting both conditions. Age was an independent risk factor only for intestinal metaplasia of the gastric corpus. When 128 H. pylori-positive subjects were analyzed, DU and age were similarly associated with the presence of both conditions.

CONCLUSIONS

These results suggest that DU reduces the risk for contracting atrophic gastritis and intestinal metaplasia, and age is an independent risk factor for intestinal metaplasia of the gastric corpus in dyspeptic Japanese patients.

Relationship between cyclooxygenase-2 expression and K-ras gene mutation in colorectal adenomas

BACKGROUND AND AIMS

Cyclooxygenase (COX)-2 has a trophic effect on gastrointestinal epithelial cells and is associated with the progression of colorectal adenomas. Mutation of the K-ras gene is also associated with the progression of colorectal adenomas and has recently been suggested to play an important role in the induction of COX-2. In the present study, we investigated the relationship between COX-2 expression and K-ras mutation in colorectal adenomas.

METHODS

Twenty-nine colorectal adenomas were obtained from specimens resected by the use of surgery or endoscopic mucosal resection and analyzed clinicopathologically. Immunohistochemistry was performed to analyze COX-2 expression in the adenoma specimens. The K-ras codon 12 mutations were detected by using the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

An increase of COX-2-positive cells in adenoma was observed in 11 (37.9%) lesions, 10 (90.9%) of which had a K-ras gene mutation, suggesting a significant correlation between COX-2 expression and K-ras gene mutation in colorectal adenomas. Morphologically, COX-2-positive adenomas (13.8 +/- 2.6 mm) were significantly larger than COX-2-negative ones (5.8 +/- 0.9 mm). In addition, the increase of COX-2-positive cells in the lesion was observed more frequently in tubulovillous (63.6%) than in tubular (36.4%) adenoma.

CONCLUSIONS

Cycloxygenase-2 expression in colorectal adenoma cells is strongly correlated with K-ras gene mutation, suggesting that COX-2 and mutated K-ras are connectively associated with the progression of colorectal adenoma.

Risk of colorectal cancer in patients with hematologic disease

BACKGROUND AND AIMS

A relatively large number of patients with multiple myeloma have been reported to develop a secondary malignancy such as cancer of the breast, biliary system or bowel.

METHODS

A retrospective study was perfomed in 734 patients with hematologic disease diagnosed at Nippon Medical School Hospital between May 1984 and September 1994 to determine the incidence of colorectal cancer in these patients based on a history review, colonoscopic findings, and surgical or autopsy data.

RESULTS

Of the 734 patients, 14 (1.9%) had colorectal cancer; two of 11 patients (18.2%) had pure red cell aplasia; two of 25 patients (8%) had multiple myeloma; and three of 46 patients (6.5%) had aplastic anemia. Patients with pure red cell aplasia, multiple myeloma or aplastic anemia had colorectal cancer at a significantly higher rate compared to those with leukemia (P< 0.005, P< 0.02, P< 0.01, respectively).

CONCLUSIONS

It is possible that a relatively large number of patients with pure red cell aplasia, multiple myeloma or aplastic anemia will develop a colorectal cancer.

Automated enumeration of cellular composition in bone marrow aspirate with the CELL-DYN 4000 automated hematology analyzer

The present study was designed to evaluate the automated analysis of bone marrow aspirates with the CELL-DYN 4000 (CD4000) hematology analyzer. Bone marrow aspirates were diluted twice with phosphate-buffered saline and assayed with the CD4000. The percentages of subpopulations including lymphocytes, neutrophils, and erythroblasts were obtained with the CD4000, and as a reference, differential counts by microscopic observation of May-Grünwald-Giemsa-stained films of bone marrow aspirate were performed (n = 48). Significant correlations (p < 0.0001) between the results with the two methods were obtained for total nucleated cell count, lymphocytes, neutrophils, erythroid cells, and the myeloid/erythroid ratio. The present method can provide quantitative data of bone marrow aspirate and will be useful in bone marrow screening.

Localisation of cyclooxygenase 1 and cyclooxygenase 2 in Helicobacter pylori related gastritis and gastric ulcer tissues in humans

BACKGROUND

Prostaglandin endoperoxide synthase/cyclooxygenase (COX) is the key enzyme in gastric mucosal protection and repair but its cellular localisation in the human stomach is still unclear.

AIMS

To investigate immunohistochemically the cellular distribution of COX-1 and COX-2 proteins in the human stomach with or without gastritis or ulceration.

PATIENTS AND METHODS

Tissues were obtained by surgical resection of gastric ulcers associated with perforation (n = 9) or by biopsy from Helicobacter pylori positive patients with gastric ulcers (n = 45) and H pylori negative healthy subjects (n = 15). COX expression was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and light and electron microscopic immunohistochemistry.

RESULTS

COX-2 mRNA and protein were detected in gastric ulcer tissues but not in intact gastric mucosa. COX-1 mRNA and protein were detected in the intact mucosa. COX-2 immunostaining was exclusively localised in macrophages and fibroblasts between necrotic and granulation tissues of the ulcer bed. The percentage of COX-2 expressing cells was significantly higher in open than in closed ulcers, and in gastritis than in gastric mucosa without H pylori infection. COX-1 immunoreactivity localised in lamina propria mesenchymal cells was similar in various stages of ulcer disease and in intact gastric mucosa. Electron microscopic immunohistochemistry revealed both COX-1 and COX-2 on the luminal surfaces of the endoplasmic reticulum and nuclear envelope of macrophages and fibroblasts.

CONCLUSIONS

Our results showed that COX-2 protein was induced in macrophages and fibroblasts in gastric ulcers and H pylori related gastritis, suggesting its involvement in the tissue repair process.

Induction of cyclooxygenase-2 in mesothelial cells in peritonitis caused by perforated ulcers--an immunohistochemical study in humans

BACKGROUND

Increasing evidence suggests that mesothelial cells contribute to the control of inflammation in the peritoneal cavity by secreting prostaglandins. A study has shown that cyclooxygenase (COX)-2 knockout mice die partly as a result of peritonitis.

AIM

To investigate the expression and location of COX in peritonitis associated with peptic ulcer perforation.

METHODS

Gastric and duodenal tissues were collected intraoperatively from nine and four patients, respectively, and immunohistochemical staining for COX-1 and COX-2 was performed.

RESULTS

Histologically, all patients had severe peritonitis around the perforation sites, into which many inflammatory cells and fibroblasts had infiltrated, and reactive mesothelial cells exhibited hyperplastic change. The COX-1 protein was not detected, whereas COX-2 was abundant in reactive mesothelial cells near the perforation site and disappeared away from the site. Macrophages and fibroblasts around the perforation site also revealed immunostaining for COX-2.

CONCLUSIONS

Our results showed that COX-2 protein is induced in mesothelial cells, as well as in macrophages and fibroblasts, in inflamed peritoneal tissues associated with peptic ulcer perforation, suggesting involvement of COX-2 in tissue repair.

Mean corpuscular volume may be a useful index of risk for colorectal adenoma in middle-aged Japanese men

OBJECTIVE

It has been reported that alcohol intake and folate deficiency are associated with an increased risk of colorectal adenomas and carcinomas. Mean corpuscular volume (MCV) of red blood cells has been reported to be increased in these conditions. The purpose of this study was to assess the association between MCV and risk of colorectal adenoma.

METHODS

The subjects were 497 middle-aged (45-65 yr old) men who underwent both barium enema examination and total colonoscopy. The subjects answered a questionnaire regarding their alcohol consumption history, and their blood samples were analyzed. The subjects were divided into four groups three times: with or without alcoholism, and with or without adenoma according to alcohol intake, and according to the MCV value. Various variables were compared among the groups, and the odds ratios of adenoma were calculated.

RESULTS

The MCV was higher in the alcoholic group than in the nonalcoholic group (p < 0.01) and in patients with adenoma than in those without adenoma (p < 0.0001). When the subjects were stratified by alcohol intake, the MCV value had a higher significant difference than alcohol intake, between patients with adenoma and those without adenoma. As for the MCV value, the odds ratio (95% confidence interval) of adenoma was 1.00 (referent); (<92), 1.20 (0.71-1.69); (> or =92 but <95), 2.61 (2.07-3.15); (> or =95 but <98); and 3.62 (2.99-4.25); (> or =98).

CONCLUSION

A high MCV value may be used as a simple index of the risk of colorectal adenomas, regardless of alcohol consumption.