Search

To investigate the pathology of gastric disorders, we compared the proteomic patterns of gastric juice from patients with various gastric disorders. In healthy subjects pepsin A, pepsin B and gastric lipase were the major proteins detected by two-dimensional gel electrophoresis. These digestive enzymes were not detected in 60% of gastric cancer cases (18 out of 30 analyzed cases). Interestingly, an extraordinary amount of alpha(1)-antitrypsin was observed in these cases. In contrast to gastric cancer cases, alpha(1)-antitrypsin was detected in only 5% of patients (three out of 56) with chronic atrophic gastritis, and the detection frequency went up as the disease developed (one of four intestinal metaplasia cases, two of seven tubular adenoma cases, a single examined case of hyperplastic polyp and 60% of gastric cancer). Zymography showed that a 60 kDa protease strongly associated with alpha(1)-antitrypsin and mass spectrometric analysis revealed that the gastric alpha(1)-antitrypsin was a protease-cleaved form. Our data suggest that alpha(1)-antitrypsin and 60 kDa protease may serve as good diagnostic and prognostic markers for conditions associated with gastric cancer.

In the present study we measured the activities of the following enzymes: LDH (lactic dehydrogenase), beta-glucuronidase, acid maltase, phosphohexoseisomerase (PHI) and acid proteases in the gastric juice of patients with gastric cancer (n = 50) (Case Group), in endoscopically normal subjects (n = 50) and in subjects with different non tumor-like digestive pathologies (n = 55) (Control Groups). In the patients with gastric carcinoma we found a significant increase in LDH, beta-glucuronidase, PHI and acid maltase activities and a decreased activity of acid proteases. The results agree with previous findings from other workers. The variations of enzyme activities in gastric juice can help to differentiate between malignant and benign processes of the gastric mucosa.

Adenosine deaminase (ADA), 5'-Nucleotidase (5NT), Xanthine oxidase (XO), Cu-Zn Superoxide dismutase (SOD) and Catalase (CAT) activities were determined in gastric juices from patients with gastric cancer, ulcer, gastritis and from healthy subjects. Enzyme activities were given as units per ml gastric juice and units per mg protein in gastric juice. ADA, 5NT and XO activities were found lower and protein concentrations were found higher in the cancer group than controls. There was however no significant difference between Cu-Zn SOD activities of the cancer and control groups. In all groups including control one, we could not find catalase activities in most of the samples. On the other hand, ADA, 5NT activities and protein concentrations in the gastric juice were lower in the gastritis group than control group. In the ulcer group, we found higher Cu-Zn SOD and XO activities and lower 5NT activity and protein concentrations compared with control values. In an attempt to establish statistical correlations between mean enzyme activities, pH and protein concentrations in the gastric juices of the groups, we found noticeable intra and inter-correlations, which indicated possible relations between DNA and free radical metabolizing enzymes.

Chromatometric assay of beta-GCD in the urine, gastric juice and saliva was conducted in 743 subjects. In the urine of 104 normal persons, 5 (4.8%) were beta-GCD positive. In the urine of 35 urinary bladder cancer patients, 20 (57.1%) were positive. beta-GCD content was very low in the gastric juice and saliva of normal subjects, giving a positivity of 0%. But it was high in the gastric juice of stomach cancer patients, giving a positive rate of 83.3%. The positivities in the saliva of stomach cancer and malignant ovarian tumor patients were both 62.2% which was higher than that of patients suffering from other malignancies or benign tumors. beta-GCD assay is simple, stable and is valid in the diagnosis of stomach cancer and ovarian malignancies. The mechanism of beta-GCD elevation and its relation to metastasis are discussed.

In an attempt to determine the significance of increased beta-glucuronidase content of gastric juice of patients with gastric carcinoma, gastric mucosal cells were exposed, in organ culture technique, to a known gastric carcinogen and indices of carcinogenic activity were studied in the ambient fluid and in the mucosal cells. Isotopic methods were used to determine cell viability. Indices of carcinogenic activity in the ambient fluid were beta-glucuronidase and lactate production and changes in the LDH isoenzyme pattern of the homogenates of the exposed cells were also studied. Incubation with the carcinogen resulted in increased production of beta-glucuronidase and lactate, suggesting the increased beta-glucuronidase activity in the gastric juice of patients with gastric cancer indicates malignancy.

Lactic dehydrogenase (LDH) and beta-glucuronidase concentrations were measured in the resting gastric juice of 113 patients presenting with dyspepsia. All patients were investigated by double-contrast barium meal, endoscopy with biopsy, and, when appropriate, by laparotomy. In all patients tested there was a positive correlation between LDH and beta-glucuronidase concentrations. An index derived from the two enzyme activities correctly predicted the presence of gastric carcinoma in 41 out of 42 cases, and identified the only 2 cases of early gastric cancer in the series. There were 13 (11.5%) false-positive results, all in cases with extensive intestinal metaplasia, a change which may be associated with an increased risk of gastric malignancy. The measurement of gastric-juice enzymes is useful in the diagnosis of gastric cancer and may be of value in the identification of high-risk groups. The test is easily performed, inexpensive, and reproducible.

Malignant transformation in cells is accompanied by enzymatic changes that may be useful markers of malignancy. Studies of oncofetal antigens in gastric juice show an increased concentration in patients with gastric carcinoma. The object of the present study was to test if the concentration of lysosomal enzymes and carcinoembryonic antigen (CEA) were altered in patients with gastric carcinoma compared to patients earlier operated with gastric resection--a supposedly premalignant condition. The results show that no differences could be found in CEA and beta-hexosaminidase levels between the patients with gastric carcinoma and those with gastric resection. However, lysozyme content was significantly higher in gastric carcinoma and might prove useful for screening of patients after gastric resection. Both CEA, beta-hexosaminidase, and lysozyme levels were significantly higher in patients with gastric carcinoma than in a control population, and can therefore have a role in screening of asymptomatic patients.

LDH is found in many body fluids and tissues. Its level is elevated in many diseases. Thus the levels of LDH in serum and gastric juice were determined in both benign and malignant disease of the upper gastro-intestinal tract using the spectrophotometric techniques. 45 patients were included in the study (duodenal ulcer 19; gastric ulcer 6; gastric polyps 5; and gastric carcinoma 15). Serum LDH levels were not significantly elevated. However, the gastric juice LDH levels were significantly elevated in gastric polyps and gastric carcinoma. The mean levels were 96.81 +/- 14.31 and 443.2 +/- 58.1 i.u./L respectively. Serial estimation of gastric juice LDH in patients with gastric polyps showed a remarkable elevation at the time of malignant transformation.

The activity of beta-glucuronidase was studied in the gastric aspirate from normal individuals, cases of duodenal ulcer with pyloric stenosis and carcinoma of the stomach. The optimum pH for the activity of this enzyme in the gastric aspirate is 4.0 to 5.5. Cimetidine, a H2-receptor antagonist, was administered orally to obtain the optimum pH for the enzyme activity, when the pH of the gastric aspirate was less than 4.0. It is observed that the enzyme activity in cases of carcinoma of the stomach is markedly elevated (p less than 0.01), when compared with other cases in this study. It is suggested that the elevated enzyme activity in the gastric aspirate could be used as a biochemical marker in the diagnosis of carcinoma of the stomach.

Measurement of beta-glucuronidase and lactic dehydrogenase in the fasting gastric juice of dyspeptic patients is a useful test for gastric cancer, but about 10% of patients tested have positive results without a demonstrable carcinoma. We have compared the histological features of multiple endoscopic gastric biopsies from 17 such patients with apparently false positive enzyme tests with gastric biopsies from 17 age and sex matched patients with negative enzyme tests. Epithelial dysplasia, a precancerous lesion, was found in 3 patients with positive enzyme tests but was not found in those with negative enzyme tests. Sulphomucin-containing intestinal metaplasia, another lesion which is associated with carcinoma of the stomach, was found in 8 patients with a positive enzyme test (including all 3 with dysplasia) but in only one patient with a negative enzyme test. These findings suggest that patients with positive gastric juice enzyme tests who do not have an established carcinoma form a group who are at increased risk of developing gastric cancer in the future and who may be worthy of long-term follow-up.

To compare the results of fibrogastroscopic study and to determine the activity of hexokinase (HK) in gastric juice 113 persons were examined 89 of them having ulcerous disease. The control group comprised 24 healthy individuals. The data obtained indicated that in the control group the activity of HK was not found in any portion of the gastric juice. In patients with ulcerous disease the presence of the enzyme was noted in 36 of 89 subjects. In two of them malignant transformation of the ulcer was observed. Patients with gastric ulcer, who show HK activity in any gastric juice portion, seem to be assessed as gastric cancer high-risk group.