Effect of gastric intubation of the gastric loss of serum albumin

In a group of 18 inpatients, the catabolism of serum albumin rate, in percentage of intravascular albumin pool, was measured during two successive periods of 7 days. In the first experimental period, we did no intubation, while during the second, a tube was kept in the stomach, with an overnight intragastric perfusion of an isotonic solution of sodium bicarbonate. With the same batches of labelled albumin, we measured the serum albumin catabolism, in a similar way, in a group of 19 normal subjects, for two weeks, without gastric intubation. The difference in the rate of serum albumin catabolism, during the first and second period, is positive and amounts to +0.547 percent +/- 0.214 (mean +/- SEM) in the intubated group, and +0.765 percent +/- 0.207 in the control group. The weaker decrease in catabolism rate during the second period in the intubated group, as compared to the control group, is not statistically significant (t = 0.731). We conclude that continuous intubation of the stomach for 7 days does not increase the catabolism rate of serum albumin. Therefore, it should not significantly increase the loss of albumin in the gastric lumen.     

Spontaneous rupture of giant gastric stromal tumor into gastric lumen

BACKGROUND: Gastrointestinal stromal tumors (GIST) constitute a large majority of mesenchymal tumors of the gastrointestinal (GI) tract, which express the c-kit proto-oncogene protein, a cell membrane receptor with tyrosine kinase activity. GI stromal tumors of the stomach are usually associated with bleeding, abdominal pain or a palpable mass. CASE PRESENTATION: A 75-year-old male presented with upper abdominal pain and palpable mass. Computed tomographic (CT) scan of the abdomen showed a large mass arising in the posterior aspect of fundus, body, and greater curvature of the stomach. Second day after the admission, there was significant reduction in the size of the tumor, clinically as well as radiologically. Endoscopic biopsy showed large bulge in fundus and corpus of the stomach posteriorly with an opening in the posterior part of the corpus, and biopsy from the edge of the opening reveled GIST. Patient underwent curative resection. CONCLUSION: Spontaneous ruptured of giant gastric stromal tumor is very rare presentation of stomach GIST. Thorough clinical examination and timely investigation can diagnose rare complication.     

The effect of gastric electrical stimulation on canine gastric slow waves

This study determined the most efficient parameters of low-frequency/long-pulse gastric electrical stimulation (GES) required to entrain gastric slow waves and also evaluated the effect of entrainment and high-frequency, short-pulse GES on gastric electrical activity (GEA). Nine dogs were fitted with stimulation wires along the greater curvature. Entrainment was observed in six or seven animals, with long-pulse GES at six cycles per minute (cpm), at various combinations of current and pulse width and was directly related to the energy delivered. Entrainment was observed in four to seven animals, with GES at 12 cpm, and the maximal driven frequency was 6 cpm. Entrainment did not significantly increase the dominant power of GEA. High-frequency, short-pulse GES, using pulse trains of 14 Hz, 5 mA, and 330 micros, with 0.1 s on and 5 s off, and pulse trains of 40 Hz, 10 mA, and 330 micros, with 2 s on 3 s off, did not affect variables of GEA. We conclude that acute low-frequency GES but not high-frequency, short-pulse GES can entrain slow waves; the power of slow waves is not affected by either type of stimulation.     

Apoptosis in gastric mucosa with stress-induced gastric ulcers.

The maintenance of gastric mucosal integrity depends upon the interplay between epithelial cell proliferation and apoptosis (programmed cell death). The Bcl-2 family of proteins plays a central role in the regulation of apoptotic cell death by suppressing the apoptosis while some others such as Bax proteins promote this process. Stress-induced gastric ulcerations are accompanied by the fall in gastric mucosal cell proliferation but little is known about the influence of the stress on the apoptosis in gastric mucosa. In the present study, the gastric epithelial apoptosis was determined by means of expression of Bax and Bcl-2 mRNA in the gastric mucosa following acute stress. Wistar rats were exposed to mild water immersion and restraint stress (WRS) for 3.5 h and then sacrificed at 0, 2, 4, 6, 12 and 24 h after the termination of WRS. At each time interval after WRS, the gastric blood flow (GBF) and the proliferating cell nuclear antigen (PCNA) labeling were determined. The apoptosis rate in the gastric mucosa was determined by the terminal deoxynucleotidyl transferase (TDT) mediated 2-deoxyuridine 5-triphosphate (dUTP)-biotin nick end-labeling (TUNEL) staining method and the expression of Bax and Bcl-2 mRNA was analyzed by RT-PCR and southern blot hybridization. WRS produced multiple erosions accompanied by the fall in GBF and PCNA index and by a dramatic enhancement in gastric epithelial apoptosis rate reaching maximum at 4 h after exposure to WRS. Following 6 and 12 h after the end of WRS the apoptotis declined but even 24 h after WRS it failed to reach the value recorded in intact gastric mucosa. The PCNA index was still significantly inhibited at 2 h after WRS but then showed significant rise at 6 and 12 h to reach at 24 h after WRS, the level similar to that measured in intact gastric mucosa. The expression of Bax mRNA was detected in intact gastric mucosa and gradually increased in first 4 h after WRS to decline at 24 h to the level not significantly different from that observed in the intact mucosa. In contrast, the expression of Bcl-2 mRNA was almost undetectable during first 4 h but showed strong signal at 6 and 12 h to decline to the control level 24 h after WRS. We conclude that: 1. Healing of WRS lesions involves an increase in GBF and mucosal cell proliferation and 2. The enhancement in gastric epithelial apoptosis accompanies the mucosal damage induced by stress and this appears to be triggered by the shift from the cell death effector Bax to the cell death repressor Bcl-2 protein.     

Biogenic amine content of rat gastric tissues during reduced gastric circulation

The content of biogenic amines in gastric tissues was studied in rats with celiac trunk stenosis 3 hours, one day, 2 and 7 days after operation. Chronic ischemia of the gastric wall was found to lead to the development of dystrophic changes in the gastric mucosa, accompanied by the decreased catecholamine content and elevated levels of histamine and serotonin.     

Regulation of gastric emptying

Studies carried out in the years since William Beaumont's direct observations of gastric motility have provided increased understanding of the physiological roles of the stomach and of the mechanisms for the regulation of gastric motility. Tonic contractions of the proximal stomach are of primary importance for transfer of liquids from the stomach to the duodenum. Peristaltic contractions of the distal stomach are of primary importance for reducing the size of solid food particles and for transfer of solids to the duodenum. Because gastric emptying requires a net antral-duodenal pressure gradient, contractions of the duodenum also influence the rate of gastric emptying. Gastrointestinal hormones, including gastrin, cholecystokinin, secretin, somatostatin, and others, are released by contact of chyme with the intestinal mucosa, and affect contractions of the proximal stomach, distal stomach, and duodenum. Neural reflexes that arise from the stomach act through autonomic motor nerves to allow regulation by the central nervous system of gastric motility. gamma-Aminobutyric acid, opioids, and bombesin may serve as central neurochemical regulators of gastric motility.     

Interactions between gastric microbiota and metabolites in gastric cancer

The development and progression of gastric cancer (GC) is greatly influenced by gastric microbiota and their metabolites. Here, we characterized the gastric microbiome and metabolome profiles of 37 GC tumor tissues and matched non-tumor tissues using 16s rRNA gene sequencing and ultrahigh performance liquid chromatography tandem mass spectrometry, respectively. Microbial diversity and richness were higher in GC tumor tissues than in non-tumor tissues. The abundance of Helicobacter was increased in non-tumor tissues, while the abundance of Lactobacillus, Streptococcus, Bacteroides, Prevotella, and 6 additional genera was increased in the tumor tissues. The untargeted metabolome analysis revealed 150 discriminative metabolites, among which the relative abundance of the amino acids, carbohydrates and carbohydrate conjugates, glycerophospholipids, and nucleosides was higher in tumor tissues compared to non-tumor tissues. The targeted metabolome analysis further demonstrated that the combination of 1-methylnicotinamide and N-acetyl-D-glucosamine-6-phosphate could serve as a robust biomarker for distinction between GC tumors and non-tumor tissues. Correlation analysis revealed that Helicobacter and Lactobacillus were negatively and positively correlated with the majority of differential metabolites in the classes of amino acids, carbohydrates, nucleosides, nucleotides, and glycerophospholipids, respectively, suggesting that Helicobacter and Lactobacillus might play a role in degradation and synthesis of the majority of differential metabolites in these classes, respectively. Acinetobacter, Comamonas, Faecalibacterium, Sphingomonas, and Streptococcus were also significantly correlated with many differential amino acids, carbohydrates, nucleosides, nucleotides, and glycerophospholipids. In conclusion, the differences in metabolome profiles between GC tumor and matched non-tumor tissues may be partly due to the collective activities of Helicobacter, Lactobacillus, and other bacteria, which eventually affects GC carcinogenesis and progression.Subject terms: Cancer metabolism, Gastrointestinal cancer     

Theory of gastric function

On the basis of some assumptions concerning gastric emptying a theory of gastric function is developed which explains the known facts —chiefly the emptying of liquids according to an exponential law. On the basis of this theory an equation is derived which relates the rate of secretion to the quantity of liquid retained in the stomach after a certain time. A study is made of the general characteristics of this equation. Some assumptions concerning different formulae describing the rate of secretion are found useful in experimental investigations, particularly in Hollander’s dilution indicator method.     

Effect of ghrelin on gastric myoelectric activity and gastric emptying in rats

Ghrelin is a recently discovered peptide in the endocrine cells of the stomach, which may stimulate gastric motility via the vagal nerve pathway. However, the mechanism of ghrelin-induced changes in gastrointestinal motility has not been clearly defined. The purpose of this study was to investigate the pharmacological effects of ghrelin on gastric myoelectrical activity and gastric emptying in rats, and to investigate whether cholinergic activity is involved in the effects of ghrelin. The study was performed on Sprague-Dawley rats implanted with serosal electrodes for electrogastrographic recording. Gastric slow waves were recorded from fasting rats at baseline and after injection of saline, ghrelin, atropine, or atropine+ghrelin. Gastric emptying of non-caloric liquid was measured by the spectrophotometric method in conscious rats. Intravenous administration of rat ghrelin (20 microg/kg) increased not only dominant frequency, dominant power and regularity of the gastric slow wave but also the gastric emptying rate when compared with the control rats (P<0.01, P<0.05, P<0.05, P<0.001 respectively). These stimulatory actions of ghrelin on both gastric myoelectrical activity and gastric emptying were not fully eliminated by pretreatment with atropine sulphate. These results taken together suggest that ghrelin may play a physiological role in the enteric neurotransmission controlling gastric contractions in rats.