Carcinoma at the esophago-gastric junction--its biological behaviour toward the squamous epithelium.

The purpose of this paper is to assess the clinical and histopathological significance of tumors at the esophago-gastric junction (EGJ). The biological behaviour of these tumors was studied, with regard to the infiltrative pattern and mitotic index, in 15 patients with tumors at the EGJ. Twenty-seven tumors at the cardia, with or without esophageal invasion, were chosen for DNA analysis at their most proximal and deepest apexes. The esophageal and gastric apexes of the tumors had the same infiltrative pattern in 14 out of 15 cases and this tendency was not altered with further stratification of the anatomical layers. In comparing the deviations of the stem lines, the relative frequency of nuclei with DNA over 4n and 6n and aneuploid from the DNA histograms between the esophageal and the deepest apexes of the tumor revealed no statistically significant differences, depending on esophageal invasion. From these results, the specificities of EGJ toward tumor invasion or activity were not regarded as consequential, and the EGJ couldn't be regarded as a barrier against tumor invasion.

Localization of galanin immunoreactivity in the opossum esophagus.

Galanin-like immunoreactivity was studied at 7 levels of the opossum esophagus, lower esophageal sphincter (LES) and adjacent portion of the stomach by indirect immunofluorescence; it was restricted to nervous structures. The majority of myenteric and submucous neurons were galanin-positive and received positive axo-somatic terminations. They also sent out axons staining positively. Galanin-positive fibers and a few atypically located neurons formed a mucous plexus at the bases of mucous glands. Varicose galanin fibers innervated the muscularis mucosae, circular and longitudinal muscle layers, while thick fascicles traversed the muscularis mucosae and circular muscle, possibly interconnecting the myenteric, submucous and mucous plexuses. Galanin-positive fibers did not supply blood vessels. There was no obvious gradient of innervation density along the esophagus, but the sphincter appeared to be more densely innervated than the esophageal body. There was no galanin-positive input to striated muscle. In view of its widespread distribution, this neuropeptide may serve multiple functions in the esophagus.

Presence, distribution, and pharmacological effects of neuropeptide Y in mammalian gastrointestinal tract.

The quantitative distribution of neuropeptide Y (NPY) immunoreactivity has been determined along the length of the gastrointestinal tract in three mammalian species; rat, pig, and guinea pig. The peptide was shown to be present in all regions studied and in all three species. Exceptionally high concentrations were found in the region of the lower esophageal sphincter. Pretreatment of rats with 6-hydroxydopamine depleted NPY concentrations by 30-40%, indicating that NPY is colocalized in part with adrenergic nerves. Characterization of the NPY immunoreactivity by high-pressure liquid chromatography revealed a single major peak. NPY immunoreactivity derived from rat extracts eluted consistently earlier from the column than synthetic porcine standard, indicating minor species differences. Pharmacological studies using longitudinal muscle from guinea pig terminal ileum demonstrated that NPY caused a dose-dependent inhibition of the electrically stimulated, neurally mediated contraction of longitudinal smooth muscle. This suggested that NPY may act presynaptically to inhibit cholinergic transmission. The effects of various NPY fragments were also tested on the same preparation. The C-terminal fragments were active but were considerably less potent than NPY, while the free acid form of NPY and N-terminal fragment (1-19) were completely inactive. Thus, this study has demonstrated the presence of NPY in the gastrointestinal tract of various species, particularly within the lower esophageal sphincter. The pharmacological actions of the peptide suggest a role in the control of nonvascular smooth muscle tone.

Distribution and content of neuropeptide Y in the human lower esophageal sphincter.

The occurrence and distribution of neuropeptide Y (NPY) was studied in smooth-muscle specimens from the human lower esophageal sphincter region by immunocytochemistry and immunochemistry. Normal individuals and patients suffering from achalasia or hiatus hernia with severe gastroesophageal reflux were examined. NPY fibers were found within and around smooth-muscle bundles of the longitudinal and the circular muscle layers and within the myenteric ganglia. Smooth-muscle specimens from patients with hiatus hernia and gastroesophageal reflux displayed numerous NPY fibers and an increased content of NPY. Specimens from patients with achalasia contained only few NPY fibers and had a decreased content of NPY as compared to specimens from control patients. Conceivably, NPY may play a role in the regulation of the lower esophageal sphincter.

Regulatory peptides in lower esophageal sphincter of pig and man.

Smooth muscle specimens from the lower esophageal sphincter (LES) region of pig and man were analyzed for vasoactive intestinal peptides (VIP), substance P (SP), enkephalin, neuropeptide Y (NPY), gastrin/cholecystokinin (CCK), neurotensin, and somatostatin using immunocytochemistry and radioimmunoassay. VIP-, SP-, enkephalin-, and NPY-immunoreactive nerve fibers were observed in the LES of both species, whereas nerve fibers containing gastrin/CCK, neurotensin, and somatostatin could not be demonstrated. The peptide-containing nerve fibers occurred in the intramural ganglia and in the smooth muscle layers. There was a rich supply of VIP- and NPY-immunoreactive fibers, whereas the supply of SP- and enkephalin-immunoreactive nerve fibers were moderate in number in both species examined. The concentration of VIP, SP, enkephalin, and NPY was comparable in the two species. The present study shows that the pattern of peptidergic innervation of the LES is similar in pig and man. It is proposed that neuronal VIP, SP, enkephalin, and NPY may serve to modulate the motor activity of the LES and that the pig is a suitable experimental animal for the study of regulatory peptides and LES functions.

[Esophagogastric junction in the dog. Study of some pHmetric technics]. / Junção gastroesofágica no cão. Estudo de algumas técnicas pHmétricas.

The authors' carried out a pHmetric study of stomach, esophagus and gastroesophageal junction in dog, using four techniques: intermittent pull-through technique, continuous pull-through technique, continuous push-through technique and rapid pull-through technique. The study was done in six adult male dogs. Each animal was studied in five sessions, having been undergone 16 examinations and having been done 4 examinations of each technique. The intermittent pull-through technique (TPI) proved to be the most adequate for the pHmetric study, because it propitiates better interaction conditions between electrode and environment. Of the techniques of continuous dislocation, the continuous push-through technique (TEC) presented the most satisfactory results, having the electrode presented little latency. The continuous pull-through technique (TPC) has its application on the dependence of the pull speed; it was observed that the less the speed the less the latency of the electrode. The rapid pull-through technique (TPCR) doesn't permit an adequate interaction between electrode-environment, in consideration of the rapidity of the examination.