Differential evacuation activity of the human gastroduodenal complex

In clinical healthy volunteers (20) the rapid of gastric evacuation of three types of test meals: the gruel with egg protein or butter are investigated by sonography. There are investigated (117): the half-time of evacuation, the area of a diameter of the antrum in the systole and diastole, the amplitude of the contraction and the frequency of it. In healthy volunteers the differentiative evacuation of the three types of the test meals are established. The reception of pancreatin (KREON 10,000) with the test meals are increasing the speed of it evacuation, but without changing the differentiative of gastric evacuation.     

Effects of propranolol on the gastroduodenal myoelectrical activity]

The effects of propranolol on the myoelectrical activity of the stomach, pylorus and duodenum were investigated in chronic experiments on rabbits. During the first phase of propranolol action a positive gastro-chronotropic effect was accompanied by a negative cardio-chronotropic effect. The gastro-chronotropic effect was 3 times higher than cardio-chronotropic one. The second phase of the propranolol effect manifested with periodical fluctuation of the gastroduodenal myoelectrical activity during stable bradycardia. Marked reactivity of the gastro-duodenum and periodical fluctuation of its activity are evidence of vital importance of the autoregulation mechanisms for gastroduodenal myoelectric activity.     

Peptic activity and gastroduodenal mucosal damage.

This contribution reviews briefly the history of the discovery and characterization of peptic activity; secretory models and current concepts regarding the regulation of pepsinogen secretion; and evidence that pepsin is a necessary co-factor for gastroduodenal mucosal injury. Several animal studies indicate that peptic activity is required for acid- and nonsteroidal anti-inflammatory drug-induced gastroduodenal ulceration. A more vigorous approach to the development of anti-peptic drugs for the treatment of peptic ulcer disease is encouraged.     

Gastric control of duodenal electric activity--the function of the gastroduodenal junction.

An investigation was made into the links between electric activity of antral and of duodeno-jejunal musculature in different functional conditions. The function of the gastroduodenal junction in this linking mechanism was analysed. The following observations were made: (a) in the absence of gastric stimulation, the slow electric activities of stomach and duodenum appear to be completely independent; (b) the gastroduodenal junction evidences no electric activity of its own but is affected by that of the two adjacent structures; (c) chemical stimulation of the gastric mucosa causes activation of the electric and mechanical activity of the stomach and analogous activation of duodenal musculature; this effect is mediated by the gastroduodenal junction; (d) very probably, the transmission of gastric activation to the duodenum is myogenic for it ceases after surgical transection but not after cooling or after ligature. The possible functional role of the pyloric junction in the complex gastroduodenal mechanism is discussed.     

Comparative evaluation of the effectiveness of the treatment of gastroduodenal Campylobacter infection in children

Schemes developed by the authors for antibacterial therapy of gastroduodenal bacterosis caused by Campylobacter spp. in children are described. The data on the treatment of 56 patients with duodenal ulcer and gastroduodenitis are presented. The efficacy of the treatment with medicines under the control of the clinical, endoscopic and microbiological indices was compared. The study showed that De-Nol, furazolidone and combination of trichopol (metronidazole) with vicair were the most efficient drugs for therapy of children with such diseases.     

On the mechanism of gastroduodenal motility inhibition under psychogenic stress in rabbits

In experiments on unanaesthetized rabbits, myoelectric activity (contractile activity index) in antral and pyloric parts of the stomach and in two sites of proximal duodenum was studied under stress induced by fastening rabbit to a table in supine position. The stressor impact induced inhibition of contractile activity in antrum and pylorus. The duodenal contractile activity after initial complete suppression overshot its initial level. Blockade of beta1/beta2-adrenoceptor with propranolol and blockade of alpha2-adrenoceptor with yohimbine did not influence qualitatively the pattern of the stressor responses of antrum and pylorus, and of the postpyloric part of duodenum. In conditions of unselective blockade of alpha-adrenoceptor with dihydroergotoxin there was no initial complete inhibition of duodenal contractile activity, and its strengthening was more expressed than in the control experiments. The received data indicate that the stressor inhibition of antral and pyloric contractile activity possibly results from activation of non-adrenergic inhibitory neurons of the enteric nervous system. The initial short-term suppression of duodenal motility resulted from its "adrenergic" inhibition which can also be a factor limiting the manifestation of stimulating effect of the humoral agent on the duodenal motility. In the period after release of the animal, index of antral and pyloric contractile activity did not significantly differ from its initial level; after beta1/beta2-adrenoceptor blockade in antral and after alpha2-adrenoceptor blockade or nonselective alpha-blockade in antral and pyloric parts of the stomach, there was decrease of contractile activity compared with its initial level; after alpha2- or beta1/beta2-adrenoceptor blockade there was no poststressor exceeding of the initial level of the duodenal contractile activity, observed in the control experiments.     

Production of a conserved adhesin by the human gastroduodenal pathogen Helicobacter pylori.

An adhesin protein with an approximate subunit molecular weight of 19,600 has been purified from the gastric pathogen Helicobacter pylori. The protein was loosely associated with the cell surface and was removed by gentle stirring or shearing. Released aggregates of the 19.6-kDa protein were removed from suspension by ultracentrifugation and separated from contaminating membranes by washing in 1.0% sodium dodecyl sulfate (SDS). The SDS-insoluble protein was purified further by Mono Q anion-exchange column chromatography. Electron microscopy of the purified adhesin demonstrated that it formed amorphous aggregates similar to the material attached to the bacterial cells and that the aggregates were morphologically distinct from typical fimbriae. Western blot (immunoblot) analysis with antiserum raised against the purified protein from one strain reacted with a protein with a similar subunit molecular weight present in all nine strains of H. pylori examined, but the protein was not present in other Helicobacter species examined. The N-terminal sequences of the 19.6-kDa protein purified from three different strains of H. pylori were identical for the first 28 amino acids, with the 10 amino-terminal residues showing limited sequence homology with the TcpA pilus protein of Vibrio cholerae. The H. pylori 19.6-kDa protein associated both with human and rabbit erythrocytes and with human buccal epithelial cells. Polystyrene microspheres coated with the protein agglutinated human, horse, and rabbit erythrocytes, suggesting that this protein species could mediate adhesion between H. pylori and eucaryotic cells. This ability to act as an adhesin may make this protein an important virulence factor for H. pylori and hence a potential target for a vaccine and therapy.     

The myoelectrical activity of the gastroduodenal area in ulcer formation due to serotonin

The effects of prolonged subcutaneous administration of serotonin on the myoelectric activity of the gastroduodenal junction were investigated in conscious rabbits. Serotonin produced the duodenogastric discoordination by increasing duodenal activity and decreasing the activity of stomach and pylorus. This discoordination resulted in gastric ulceration. Atropine prevented both duodenogastric discoordination and ulceration. These results indicate that serotonin ulceration is related to duodenogastric discoordination.     

Changes of gastroduodenal peroxidase activity of rats by cerebellar modulation

The effect of vestibulo-cerebellar lesion and its stimulation by rotation on gastric and duodenal peroxidase activity of rats was studied. Vestibulocerebellar lesion by kainic acid produced gastroduodenal ulceration and peroxidase activity of these tissues were decreased. Mucosal thickness of gastric and duodenal tissue were also decreased. It was observed that when vestibulo-cerebellar lesioned rats were subjected to vestibular stimulation, the peroxidase activity was increased together with increased mucosal thickness of gastric and duodenal tissue. At the same time, it was noted that the severity of ulceration was decreased. We conclude that the study of peroxidase activity is a sensitive and potentially useful estimate of gastric and duodenal injury produced by cerebellar lesion that can be valuable in assessing ulcerogenesis and healing.