Reduced tissue type plasminogen activator activity of the gastroduodenal mucosa in peptic ulcer disease

Unusual case of retroperitoneal hematoma and duodenal ulcerative bleeding after nephrectomy: Case report

RATIONALE

Retroperitoneal hematomas are relatively common in patients undergoing nephrectomy. Herein, we report an unusual case involving a giant retroperitoneal hematoma and subsequent duodenal ulcerative bleeding following a radical nephrectomy.

PATIENT CONCERNS

A 77-year-old woman was admitted to our hospital for lower back pain, and she had severe right hydronephrosis and a urinary tract infection.

DIAGNOSES

The patient was diagnosed and confirmed as high-grade urothelial carcinoma.

INTERVENTIONS

After ineffective conservative treatments, a right radical nephrectomy and ureteral stump resection were performed. The patient received proton pump inhibitors to prevent stress ulcer formation and bleeding. On the first day post-surgery, she had normal gastrointestinal (GI) endoscopy findings. On the second day post-surgery, abdominal computed tomography revealed a retroperitoneal hematoma. Notably, 14 days post-surgery, massive GI bleeding occurred, and GI endoscopy identified an almost perforated ulcer in the bulbar and descending duodenum.

OUTCOMES

The patient died on day 15 after surgery.

LESSONS

Duodenal ulceration and bleeding might occur following a retroperitoneal hematoma in patients treated with nephrectomy. Timely intervention may prevent duodenal ulcers and complications, and thus could be a promising life-saving intercession.

The role of plasminogen activator inhibitor-1 in gastric mucosal protection

Gastric mucosal health is maintained in response to potentially damaging luminal factors. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) disrupt protective mechanisms leading to bleeding and ulceration. The plasminogen activator system has been implicated in fibrinolysis following gastric ulceration, and an inhibitor of this system, plasminogen activator inhibitor (PAI)-1, is expressed in gastric epithelial cells. In Helicobacter pylori-negative patients with normal gastric histology taking aspirin or NSAIDs, we found elevated gastric PAI-1 mRNA abundance compared with controls; the increase in patients on aspirin was independent of whether they were also taking proton pump inhibitors. In the same patients, aspirin tended to lower urokinase plasminogen activator mRNA. Immunohistochemistry indicated PAI-1 localization to epithelial cells. In a model system using MKN45 or AGS-GR cells transfected with a PAI-1 promoter-luciferase reporter construct, we found no evidence for upregulation of PAI-1 expression by indomethacin, and, in fact, cyclooxygenase products such as PGE2 and PGI2 weakly stimulated expression. Increased gastric PAI-1 mRNA was also found in mice following gavage with ethanol or indomethacin, but plasma PAI-1 was unaffected. In PAI-1(-/-) mice, gastric hemorrhagic lesions in response to ethanol or indomethacin were increased compared with C57BL/6 mice. In contrast, in PAI-1-H/Kβ mice in which PAI-1 is overexpressed in parietal cells, there were decreased lesions in response to ethanol and indomethacin. Thus, PAI-1 expression is increased in gastric epithelial cells in response to mucosal irritants such as aspirin and NSAIDs probably via an indirect mechanism, and PAI-1 acts as a local autoregulator to minimize mucosal damage.

Expression of urokinase-type plasminogen activator and its receptor in gastric fibroblasts and effects of nonsteroidal antiinflammatory drugs and prostaglandin

In acute inflammatory condition, little is known about the expression of the urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in the gastric fibroblasts. To clarify the role of human gastric fibroblasts in acute inflammatory conditions such as gastric ulcer, the effects of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on the expression of uPA and uPAR, which were suggested to be associated with tissue remodeling, in gastric fibroblasts were investigated. The expression level of uPA mRNA and the amount of uPA antigen increased significantly on treatment with each concentration of IL-1beta (1 and 10 ng/ml) and 10 ng/ml TNF-alpha. On the other hand, the amounts of uPA antigen on cell surfaces were not affected significantly by IL-1beta and TNF-alpha stimulation. The expression level of uPAR mRNA increased in a dose-dependent manner on IL-1beta stimulation. The effect of indomethacin on uPA and uPAR expression in these cells was also examined. When gastric fibroblasts were treated with 50 microM indomethacin, the expression level of uPA mRNA decreased significantly, and the amount of uPA antigen in the culture medium and on cell surfaces decreased significantly with indomethacin in a dose-dependent manner. The increased uPAR mRNA expression caused by IL-1beta was reduced to the basal level by treatment with 50 microM indomethacin. Furthermore, we investigated the role of prostaglandin E2 (PGE2), which is suggested to play major roles in acute inflammation of the stomatch, on uPA and uPAR expression in gastric fibroblasts. The expression level of uPAR mRNA and the amount of uPA antigen on cell surfaces increased in a dose-dependent manner on treatment with PGE2 (10 and 50 ng/ml). These results suggest that uPA and uPAR expression in gastric fibroblasts is involved in the regulating system of PGE2 and that NSAIDs may delay healing of gastric mucosal injury in part through suppressing uPA production via inhibition of endogenous PG production.

Enhanced mucosal fibrinolytic activity in gastroduodenal ulcer haemorrhage and the beneficial effect of acid suppression

BACKGROUND

The high mortality rate in patients with upper gastrointestinal bleeding appears to be particularly related to re-bleeding. The haemostatic mechanisms that may influence the re-bleeding of ulcers are largely unknown.

AIM

We studied and analysed fibrinolytic activity in bleeding ulcer patients and the effect of acid suppression on this activity.

METHODS

Fibrinolytic activity was analysed in mucosal biopsies from 29 bleeding gastroduodenal ulcer patients and six controls. We analysed levels of D-Dimer, fibrin plate lysis area, plasminogen activator activity, plasminogen activator inhibitor activity, and plasmin antiplasmin complexes.

RESULTS

Significantly more fibrinolytic activity was detected in biopsies from patients with bleeding ulcers compared to controls. Moreover, in patients with endoscopic stigmata of recent haemorrhage, mucosal fibrinolytic activity was higher compared to patients without stigmata of recent haemorrhage. In mucosal biopsies of patients that had used acid suppression before admission, a decreased fibrinolytic activity was found compared to patients without such therapy. This effect of acid suppression on fibrinolytic activity was confirmed in nine patients before and after a 24-h ranitidine infusion.

CONCLUSIONS

Fibrinolytic activity is enhanced in patients with bleeding gastroduodenal ulcers. Acid suppressive therapy decreases this increased activity, which may be one of the mechanisms explaining the potential beneficial effect of this therapy.

Prognostic value of fibrinolytic tests for hospital outcome in patients with acute upper gastrointestinal hemorrhage

GOALS

We assessed the predictive value of fibrinolytic tests for hospital outcome in a prospective study of 84 nonconsecutive patients with acute upper gastrointestinal hemorrhage.

STUDY

Six readily available parameters of activated fibrinolysis (fibrinogen, D-dimer, tissue plasminogen activator [TPA], plasminogen activator inhibitor type 1 [PAI-1], TPA--PAI-1 complexes, and plasmin-alpha 2-antiplasmin complexes) were tested for association with hospital outcome. Patients were divided into the following three groups: patients who survived and did not require transfusion or surgery, those who survived without surgery but required transfusion, and those who required surgery or died.

RESULTS

Patients with adverse outcome (surgery and/or death) showed significantly higher plasma levels of D-dimer than patients with favorable outcome (p = 0.01). Plasma concentrations of D-dimer >300 ng/mL showed a 20.5% positive predictive value of adverse outcome, with a relative risk of 7.5 (95% CI: 1--57%). Patients who required transfusion showed significantly higher plasma levels of TPA (p = 0.01). A positive correlation between endoscopic bleeding stigmata and D-dimer in the subgroup of patients without liver cirrhosis was found (p = 0.02); however, in the multivariate logistic regression analysis the concentration of D-dimer did not appear as an independent predictor of adverse outcome.

CONCLUSIONS

These findings are consistent with the role of increased local fibrinolysis in the digestive tract, particularly of D-dimer, in patients with upper gastrointestinal hemorrhage and adverse outcome. Accordingly, plasma fibrinolytic tests may constitute an appropriate prognostic marker in upper gastrointestinal bleeding.

Histamine and tissue fibrinolytic activity in duodenal ulcer disease

Patients with duodenal ulcer have lower gastroduodenal mucosal histamine and a reduced tissue fibrinolysis at the ulcer edge. In the duodenal mucosa fibrinolysis is regulated by the tissue-type and urokinase-type plasminogen activators; and inhibitors type 1 and type 2. Trends across ordered groups leading from mucosa of nonulcer control subjects, "normal" mucosa of ulcer patients, to ulcer edge were found in tissue-type plasminogen activator concentration, histamine concentration, and histamine methyltransferase activity. Concentrations of tissue-type activator, inhibitor type 1, and histamine were significantly lower at ulcer edge than at normal. An inverse correlation was found between histamine methyltransferase and plasminogen activator activities, methyltransferase and tissue-type activator, and methyltransferase and histamine. These results support the hypothesis that in active ulceration, reduction in tissue fibrinolytic activity is closely associated with enhanced release and metabolism of histamine.

Studies on gastric mucosal microcirculation. 1. The nature of regional variations induced by ethanol injury

BACKGROUND/AIMS

The focal nature of gastric ulcers raises the possibility of underlying regional disturbances in gastric mucosal microcirculation. This study employed fluorescent in vivo microscopy with the aim of directly investigating the response of several areas of the gastric mucosa to 60% ethanol.

METHODS

Changes in macromolecular leakage of fluorescein labelled albumin, vessel diameter, and acridine red labelled leucocyte adhesion and rolling were assessed over a period of two hours. A total of 0.5 ml 60% ethanol was topically applied for five minutes to the exteriorised gastric mucosa of anaesthetised rats. RATS: Three distinct patterns of response were found. Areas of lesion formation were small and occurred within five minutes. These areas showed persistent blood flow stasis throughout the course of the experiment, increased leakage (p < 0.02), and no leucocyte adhesion. Peripheral to the lesion, sustained leakage (p < 0.02) was found with adherence of leucocytes (p < 0.01) after lesion formation. Sites more remote to any lesion showed transient leakage and significant numbers of 'rolling' leucocytes (p < 0.01) were observed again after the lesion had formed.

CONCLUSIONS

Despite widespread exposure of the entire gastric mucosa to 60% ethanol the resultant mucosal injury was limited. Widespread vascular damage was found reflected by macromolecular leakage, the pattern of which showed regional variation.

Gastric mucosal plasminogen activators in Helicobacter pylori infection

Long-term H. pylori associated gastritis is recognized as a pathogenic factor in gastric carcinogenesis. In gastric carcinomas the amount and activity of the tissue-type plasminogen activator (t-PA) have been reported to be decreased, whereas those of the urokinase-type plasminogen activator (u-PA) were increased, contributing to the neoplastic and invasive process. The present study was performed to determine t-PA and u-PA levels and activity in gastric mucosa from 102 patients and to investigate whether these levels are influenced by H. pylori infection. The antigen concentration and activity of t-PA and u-PA in corpus mucosa were low (P < 0.001) compared with those in antral mucosa, although for the u-PA activity this did not reach statistical significance. In H. pylori-associated antral gastritis the mucosal t-PA antigen concentration and activity were found to be decreased (P < 0.001) compared with normal mucosa, whereas in H. pylori-associated pangastritis the corpus t-PA levels were not affected. The antigen concentration and activity of u-PA were found to be significantly (P < 0.005) increased, both in H. pylori-associated gastritis of antrum and corpus mucosa. Levels of u-PA in histologically normal corpus mucosa of patients with an H. pylori-associated antral gastritis were also found to be increased (P < 0.05). In conclusion, the alterations in the plasminogen activator profile found in H. pylori-associated gastritis, ie, a decrease in t-PA and an increase in u-PA, show a similar tendency as the previously found alterations in gastric carcinomas, which provides additional support for the possible involvement of H. pylori-associated gastritis in the pathogenesis of gastric carcinoma.