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- Brannstrom, J, et al.
(författare)
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Helicobacter pylori stimulates DNA synthesis in a small intestinal cell line in vitro
- 1998
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Ingår i: Digestion. - : S. Karger AG. - 0012-2823 .- 1421-9867. ; 59:1, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- <b>Background:</b> <i>Helicobacter pylori</i>, which causes gastritis and peptic ulcer, seems to be an important factor in the pathogenesis of gastric cancer and MALT lymphoma. Thus our aim was to examine whether <i>H. pylori</i> influences DNA synthesis in epithelial cells in vitro. <b>Methods:</b> Sonicated and water extracts of <i>H. pylori</i> (cytotoxic strains NCTC 11637, 88-23 and A5, and a noncytotoxic isogenic mutant of A5, A5 vac A) were diluted to a final concentration of 1/1,000, 1/100, 1/50 and 1/10. Water extracts of <i>Escherichia coli</i> were used as reference. IEC-6 cells were incubated during 24 h with fragments of <i>H. pylori</i> or extracts of the concentrations described above. The cells were labeled with <sup>3</sup>H-methylthymidine for 4 h and processed for autoradiography. DNA synthesis was evaluated by the labeling index (LI). <b>Results:</b> The LI% of controls was 15.6 ± 5.1%. All the water extracts and sonicated strains of <i>H. pylori</i> increased the LI% in a dose-dependent manner (p < 0.001). The highest concentrations of the sonicated strains tended to reduce the LI%, although these values were still higher than those of the control group. The water extracts of <i>E. coli</i> increased the LI% in a dose-dependent manner (p < 0.0001). <b>Conclusion:</b> <i>H. pylori</i> stimulates DNA synthesis in epithelial cells in vitro, but no association was found with the presence of cytotoxin production. Our results suggest that hitherto unknown components of <i>H. pylori</i> may contribute to the increase in cell proliferation observed in gastritis and to the development of MALT lymphoma and gastric cancer.
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| 2. |
- Jahnson, S, et al.
(författare)
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Anastomotic blood-flow reduction in rat small intestine with chronic radiation damage.
- 1998
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Ingår i: Digestion. - 0012-2823 .- 1421-9867. ; 59:2, s. 134-41
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Anastomoses in previously irradiated intestine are prone to leakage, possibly due to an impeded blood supply. Whether or not chronic radiation damage actually predisposes to a disturbed blood flow in the vicinity of anastomoses was investigated in the rat small bowel.METHOD: A 2-cm segment of rat ileum was irradiated with a single dose (21 Gy). After 20 weeks an anastomosis was created in the irradiated segment and in the corresponding segment of controls. Another 4 days later local blood flow was studied with the 14C-iodoantipyrine autoradiography technique in 16 sectors around the circumference both in the anastomotic segment and in a segment 4 mm apart.RESULTS: In the anastomotic segment, the average blood flow was reduced in irradiated compared with non-irradiated animals in the mucosal layer (p = 0.034), but not in the muscular layer (p = 0.08). In the mesenteric quadrant blood flow was reduced in irradiated compared with non-irradiated animals, both in the mucosal layer (p = 0.012) and in the muscular layer (p = 0.05). More irradiated than non-irradiated animals showed a blood-flow reduction to 15% or more in 13-16 sectors both in the mucosal (p = 0.015) and the muscular layer (p = 0.04).CONCLUSIONS: The results favor the hypothesis that anastomoses in previously irradiated intestine are vascularly compromized and thereby have an increased risk of leakage.
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| 5. |
- Kölby, Lars, 1963, et al.
(författare)
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Gastric carcinoid with histamine production, histamine transporter and expression of somatostatin receptors.
- 1998
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Ingår i: Digestion. - 0012-2823. ; 59:2, s. 160-6
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Tidskriftsartikel (refereegranskat)abstract
- A case of sporadic, histamine-producing gastric carcinoid with liver metastases is reported. The patient was treated with somatostatin analogue (octreotide) combined with cortisone and blockade of histamine receptors prior to surgery, which included subtotal gastrectomy, excision of lymph node metastases and superficial liver metastases. Residual liver metastases were injected with ethanol. These interventions markedly reduced the urinary excretion of the main histamine metabolite (MelmAA). Eighteen months later combined immuno- and chemotherapy was initiated due to tumour progression and recurrent hormonal symptoms with good clinical results over 12 months. Scintigraphy, using 111In-DTPA-D-Phe1-octreotide, visualized somatostatin receptors (sstr) in primary tumour, lymph node metastases and liver metastases. The tissue/blood 111In concentration ratios of tumour biopsies were very high. Northern analyses confirmed expression of all subtypes of sstr1-5. Immunocytochemically, tumour cells were strongly positive for chromogranin A, histamine and vesicular monoamine transporter (VMAT) 2 (histamine transporter), but negative for VMAT 1, suggesting an origin from gastric enterochromaffin-like cells. In primary tumour cell cultures, histamine, 5-HTP and 5-HIAA, but not 5-HT, could be detected in conditioned culture medium, indicating a defective decarboxylation of the tryptamine precursor. This rare case of histamine-producing gastric carcinoid demonstrates that excellent symptom relief can be achieved despite disseminated disease, if active, multimodal treatment strategy is instituted. The presence of high numbers of sstr in tumour tissue also raises the possibility of receptor-guided radiotherapy.
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