The sources of the innervation of the sphincter of the esophagogastric junction in rats]

The investigation has been performed by means of the luminescent microscopical method. The retrograde axonal transport of the fluorescent marker primuline has demonstrated that a definite amount of labelled cells are observed in the celiac plexus, in nodes of the thoracic part of the sympathetic trunk (predominantly in Th6-Th8). Innervation of the EGP sphincter is mainly performed from the sympathetic trunk nodes (Th6-Th8) and from the celiac plexus.     

Effect of prostaglandin E2 on esophageal motility in man.

Studies were performed to investigate the effect of prostaglandin E2 on esophageal motility in 12 healthy volunteers. PGE2 infusion caused a dose-dependent reduction in the lower esophageal sphincter pressure. The threshold dose was less than 0.05 mug-kg-1-min-1 and maximal reduction of pressure (60%) occurred with a dose of 0.4 mug-kg-1-min-1. In contrast to its effect on the lower esophageal sphincter, PGE2 did not alter the pressure in the upper esophageal sphincter. PGE2 did not influence resting esophageal pressures; the amplitude of peristaltic contractions was reduced in the lower but not in the upper part of the body of the esophagus. These studies show that in man PGE2 exerts selective inhibitory influence on the activity of the lower part of the esophagus and lower esophageal sphincter which are composed of smooth muscle fibers.     

Measuring esophageal distension by high-frequency intraluminal ultrasound probe

Distension of the esophagus can cause heartburn and chest pain; however, none of the available techniques to study the esophagus measure esophageal distension. We evaluated the technique of high-frequency intraluminal ultrasound probe (HFIUS) to measure the esophageal cross-sectional area (CSA) during gastroesophageal reflux (GER). The following methods were used: 1) the CSA of agarose gel tubes of known dimensions were measured using ultrasound probes; 2) seven normal subjects were studied to evaluate the esophageal CSA during different bolus volumes (1, 5, 10, 15, and 20 ml) of water swallows (WS); and 3) simultaneous pressures, pH, and ultrasound images of the esophagus were recorded in healthy subjects. In vitro studies showed that the HFIUS measured the CSA of the tubes accurately. The maximal CSA of the distal esophagus during WS with boluses of 1, 5, 10, 15, and 20 ml were 54, 101, 175, 235, and 246 mm(2), respectively. Esophageal contents during 62 episodes of transient lower esophageal sphincter relaxations, 29 pH positive, and 33 pH negative GER episodes revealed that reflux of air into the esophagus occurred more frequently than liquid. The median CSA and estimated diameter of the esophagus during liquid GER was 44.1 mm(2) and 7.5 mm, respectively. We conclude that HFIUS is a valid technique to measure the CSA of the esophagus in vivo during GER. Distension of the esophagus during physiological GER is relatively small.     

The morphology of the cardia and the pylorus in the Chiroptera

Organ complexes of bats (Nyctalis noctula), consisting of oesophagus, stomach and initial part of the small intestine have been subjected to histological and morphometrical investigation. As demonstrates the histological investigation of the preparations, the denticulate line of the mucous membrane of the oesophageal-gastric passage is displaced towards the stomach. In the cardia a well manifested internal sphincter has been revealed. In the place, where the stomach passes into the small intestine, on a small area of the submucosal tela of the intestine, there is an accumulation of secretory parts of the duodenal glands. They form a glandular torulus, which narrows the transitional zone lumen. A peculiarity of the bat pylorus is absence of an anatomical sphincter in it.     

Relationship between esophageal muscle thickness and intraluminal pressure: an ultrasonographic study

A number of studies show a close temporal relationship between the rate of change in muscle thickness as detected by high-frequency intraluminal ultrasonography (HFIUS) and intraluminal pressure measured by manometry. There is a marked variability in esophageal contraction amplitude from one swallow to another at a given level in the esophagus and along the length of the esophagus. Furthermore, peristaltic pressures are higher in the distal compared with the proximal esophagus. The goal of this study was to evaluate the relationship between the baseline and peak muscle thickness and the contraction amplitude during swallow-induced contractions along the length of the esophagus. Fifteen normal subjects were studied using simultaneous esophageal pressures and HFIUS or HFIUS alone. Recordings were made during baseline and standardized swallows in the lower esophageal sphincter (LES) and at 2, 4, 6, 8, and 10 cm above the LES. HFIUS images were digitized, and esophageal muscle thickness and peak contraction amplitudes were measured. In the resting state, muscle thickness is higher in the LES compared with the rest of the esophagus. Baseline muscle thickness is also significantly higher at 2 cm vs. 10 cm above the LES. In a given subject and among different subjects, there is a good relationship between peak muscle thickness and peak peristaltic pressures (r = 0.55) at all sites along the length of the esophagus. The positive correlation between pressure and muscle thickness implies that the mean circumferential wall stress is fairly uniform from one swallow to another, irrespective of the contraction amplitude.     

Lymphoid structures in the wall of the human esophagus during postnatal ontogenesis

Lymphoid aggregates in the wall of the human oesophagus have been studied in corpses of 107 persons died a sudden death and who had not any disease in the digestive organs and in the immune system (total plane preparations, slices stained with hematoxylin--eosin, azure-2-eosin and after van Gieson). The lymphoid aggregates are arranged as longitudinal chains. Their number increases from birth towards the second childhood, and then decreases towards the old age. In the upper oesophageal parts these aggregates are more numerous than in the lower ones. The lymphoid aggregates look like convexoconvex lenses. Their size is maximal during the second childhood, the longitudinal dimensions are nearly two times as great as their thickness. With time, the sizes of the formations become small. The arrangement density of the lymphoid cells in the subepithelial layer of the mucous membrane is maximal in newborns, and then it decreases up to the old age. The lymphoid aggregates are situated in the oesophageal wall, mainly, near the ducts of the oesophageal glands.     

Local characteristics and interrelations between glands and lymphoid conglomerations in the esophageal wall

Proper glands in 248 total preparations and lymphoid accumulations in 112 preparations have been investigated macro-microscopically in the human oesophageal preparations at various age. The organs have been obtained from 152 corpses of persons died from the death by violence and having no pathological changes in the organs of digestive and immune systems. The lymphoid tissue in the oesophageal wall is presented as accumulations of cells (prenodules++) and as diffusely scattered immune-competent cells. The glands and lymphoid accumulations are oriented as longitudinal rows. The lymphoid tissue accumulations are situated near to the glandular ducts, because the latter can serve as pathways for penetrating antigenic material into the organ's wall. The amount of the glands is maximal mature and elderly age, and that of lymphoid accumulations--at the second childhood. The dimensions of the gland body increase in the cranio-caudal direction, while the lymphoid accumulations, just the reverse, have their maximal dimensions in the upper third of the oesophagus. The gland bodies in places of the organ's anatomical narrowings in the section have more alveoles and are situated nearer to the covering epithelium than the glands in the neighbouring areas of the wall.     

Achalasia in a sixty-four-year-old man.

Achalasia is an esophageal motility disorder characterized by increased lower esophageal sphincter pressure and absence of peristalsis in the lower esophagus. Patients typically present with complaints of progressive difficulty swallowing over a period of several years. Diagnosis is confirmed by esophageal manometry. Complications of achalasia include esophagitis, aspiration and possibly an increased risk of esophageal carcinoma. Medical treatment options include pneumatic dilatation, esophageal bougienage, nitrates, calcium channel blockers and botulinum toxin injections. The primary method of surgical treatment is the Heller myotomy, in which longitudinal incisions are made in the muscle fibers of the lower esophageal sphincter to reduce sphincter pressure. Frequently, a fundoplication is performed in addition to the myotomy to decrease the likelihood of development of gastroesophageal reflux. In recent years, the Heller myotomy has been performed both thoracoscopically and laparoscopically. An additional development has been the placement of an endoscope in the esophagus to provide transillumination during surgery; intraoperative endoscopy allows improved assessment of the depth of myotomy incisions and reduces the risk of esophageal perforation. The case report below describes a 64-year-old-man with achalasia who presented with persistent dysphagia despite multiple attempts at medical treatment. A laparoscopic Heller myotomy with Toupet fundoplication was performed with subsequent eradication of symptoms. A discussion of the epidemiology, etiology, clinical presentation, diagnosis and treatment of achalasia follows the case report.     

LIPID COMPOSITION OF GLIAL CELLS ISOLATED FROM BOVINE WHITE MATTER

Abstract— —Glial cells were isolated from bovine white matter by differential centrifugation with'Ficoll'and their lipid composition was analysed. The preparations contained 20.8 per cent lipid and 792 per cent protein. The major lipid components were cholesterol, ethanolamine glycerophosphatides (EGP), cerebroside and serine glycerophosphatides (SGP). Sphingomyelin, cerebroside sulphate and inositol glycerophosphatide were present in lower proportions. EGP contained the largest proportion of aldehydes (17 per cent) and SGP contained 12 per cent. Choline glycerophosphatides contained only a trace of aldehyde. No gangliosides were present in the filial cell preparations.     

Influence of methochlopramide on the motor function of the esophagus and the cardial sphincter]

In acute experiments on cats and in chronic experiments on dogs the contractile activity of the esophagus and the cardiac sphincter was recorded with a ballon pulled from the stomach to the esophagus connected to a catheter. The intravenous injection of Metoclopramide in doses of 0.5--0.6 mg/kg to cats and subcutaneous injection of Metoclopramide in doses of 0.1--0.15 mg/kg to dogs elevated the pressure in the cardiac sphincter significantly increased the motility of the distal esophagus and stimulated the esophago-gastric inhibitory reflex. These effects persisted for 2.5--3 hrs; they were phasic in nature and were preserved after vagotomy in dogs. A conclusion was drawn that Metoclopramide could be useful in pathology of the distal esophagus, including the cardiac sphincter.     

Sharing food in the stomachs of seabirds between adults and chicks--a case for delayed gastric emptying

1. Retention times of food in stomachs of breeding and non-breeding African pengiuns (Spheniscus demersus) were examined. 2. Rates of gastric emptying in non-breeding birds were linearly related to the mass of food in the stomach. 3. Breeding birds returned to the nest with more food in their stomachs when chicks were larger. The rate of regurgitation of food was linearly related to chick mass. 4. Retention times of food in the stomachs of breeding penguins can only be explain by cognisance of observed regurgitation rates and by assuming that there is no gastric emptying through the pyloric sphincter.     

Relationship between esophageal muscle thickness and intraluminal pressure in patients with esophageal spasm

We previously showed, in normal subjects, a positive correlation between the esophageal contraction amplitude and peak muscle thickness. The goal of this study was to determine the relationship between esophageal muscle thickness and contraction amplitude in patients with high-amplitude peristaltic and simultaneous contractions. Eleven patients with high-amplitude peristaltic contractions, 8 with diffuse esophageal spasm (DES), 7 with nonspecific (NS) motor disorder of the esophagus, and 10 normal subjects were studied using simultaneous pressure and ultrasound imaging. Pressure was recorded by manometry and ultrasound imaging with a high-frequency ultrasound probe catheter. Recordings were performed in the lower esophageal sphincter (LES) and at 2, 4, 6, 8, and 10 cm above the LES during resting state and swallow-induced contractions. Baseline esophageal muscle was thicker in the distal, compared with the proximal esophagus both in normal subjects and patient groups. Patients with DES and nutcracker esophagus (NC) have a higher baseline muscle thickness compared with normal and NS patients. Correlation between the peak pressure and the peak muscle thickness was weaker in patients with NC and DES compared with normal subjects and patients with NS. Whereas normal subjects have good correlation between delta (difference between peak and baseline) muscle thickness and peak pressures, this relationship was absent in patients with NC and DES. Increase in contraction amplitude in patients with NC and DES was associated with an increase in baseline thickness of esophageal muscularis propria. Increase in baseline thickness was specific to patients with spastic motor disorders and was not seen in patients with NS.     

Liquid in the gastroesophageal segment promotes reflux, but compliance does not: a mathematical modeling study

The mechanical force relationships that distinguish normal from chronic reflux at sphincter opening are poorly understood and difficult to measure in vivo. Our aim was to apply physics-based computer simulations to determine mechanical pathogenesis of gastroesophageal reflux. A mathematical model of the gastroesophageal segment (GES) was developed, incorporating the primary anatomical and physiomechanical elements that drive GES opening and reflux. In vivo data were used to quantify muscle stiffness, sphincter tone, and gastric pressure. The liquid lining the mucosa was modeled as an "effective liquid film" between the mucosa and a manometric catheter. Newton's second law was solved mathematically, and the space-time details of opening and reflux were predicted for systematic variations in gastric pressure increase, film thickness, muscle stiffness, and tone. "Reflux" was defined as "2 ml of refluxate entering the esophagus within 1 s." GES opening and reflux were different events. Both were sensitive to changes in gastric pressure and sphincter tone. Reflux initiation was extremely sensitive to the liquid film thickness; the protective function of the sphincter was destroyed with only 0.4 mm of liquid in the GES. Compliance had no effect on reflux initiation, but affected reflux volume. The presence of abnormal levels of liquid within the collapsed GES can greatly increase the probability for reflux, suggesting a mechanical mechanism that may differentiate normal reflux from gastroesophageal reflux disease. Compliance does not affect the probability for reflux, but affects reflux volume once it occurs. Opening without reflux suggests the existence of "gastroesophageal pooling" in the distal esophagus, with clinical implications.     

Dissymmetry in the structure and dimensions of the temporal operculum of the cerebral hemispheres

In 130 cerebral preparations of children and mature persons external structure and dimensions of the temporal operculum, pertaining to the posterior speech cerebral area, have been studied. A great variability in the operculum form, in the number of tertial sulci situating on it, in its linear dimensions and superficial area has been stated. Final dimensions of the temporal operculum are formed in early childhood and have no sex differences. During all age periods, there is a pronounced left-sided tendency in dimensional asymmetry of the temporal operculum dimensions; their predominance in the left side is noticed in more than 70%. No correlation between the operculum surface and the brain mass is revealed, as well as between its surface and the surface of transversal temporal gyri. The left-sided predominance in the length of the lateral sulcus is observed nearly as often as the left-sided prevalence of the temporal operculum, but in a number of cases their asymmetry has an opposite direction. This should be taken into consideration at diagnosing the dominant hemisphere by means of the intravital arteriography and when certain neurosurgical interventions are performed.     

A qualitative and quantitative study on the enkephalinergic innervation of the pig gastrointestinal tract.

Enkephalins are involved in neural control of digestive functions such as motility, secretion, and absorption. To better understand their role in pigs, we analyzed the qualitative and quantitative distribution of enkephalin immunoreactivity (ENK-IR) in components of the intestinal wall from the esophagus to the anal sphincter. Immunohistochemical labelings were analyzed using conventional fluorescence and confocal microscopy. ENK-IR was compared with the synaptophysin immunoreactivity (SYN-IR). The results show that maximal ENK-IR levels in the entire digestive tract are reached in the myenteric plexuses and, to a lesser extent, in the external submucous plexus and the circular muscle layer. In the longitudinal muscle layer, ENK-IR was present in the esophagus, stomach, rectum, and anal sphincter, whereas it was absent from the duodenum to the distal colon. In the ENK-IR plexuses and muscle layers, more than 60% of the nerve fibers identified by SYN-IR expressed ENK-IR. No ENK-IR was observed in the internal submucous plexus and the mucosa; the latter was found to contain ENK-IR endocrine cells. These results strongly suggest that, in pigs, enkephalins play a major role in the regulatory mechanisms that underlie the neural control of digestive motility.     

The protective activity of preparations made from the tick-borne encephalitis virus grown using different cell cultures]

The preparations of tick-borne encephalitis (TBE) virus grown in swine embryo kidney cell culture have been shown to possess pronounced protective activity per unit of virion protein E in comparison with TBE virus preparations derived from cell culture 4647 and chick embryo cell culture. The antigenic activity of all virus preparations under study has proved to be practically the same. The role of post-translation modifications of TBE virus protein E in the manifestation of some of its biological properties is discussed.     

Structure of the digestive tract of the pluteus larva of Dendraster excentricus (Echinodermata: Echinoida)

Summary Histological and ultrastructural observations of the digestive tract of eight-armed plutei of Dendraster excentricus are reported. The esophagus is divided into two regions. The uppermost is a narrow tube comprised of ciliated cells that assist in transporting food to the more bulbous lower esophagus where food particles are formed into a bolus prior to entering the stomach. The esophagus is surrounded by a network of smooth muscle fibers that are predominantly oriented circumferentially in the upper esophagus, and longitudinally in the lower esophagus. The musculature of the upper esophagus produces peristaltic contractions, whereas contractions of the muscle of the lower esophagus open the cardiac sphincter and force food from the lower esophagus into the stomach. Axons are associated with the ciliated cells and the muscles of the upper esophagus. The cardiac sphincter consists of a ring of myoepithelium, with cross-striated myofibrils oriented around the bases of the cells. The gastric epithelium is comprised of two cell types. Type I cells, which predominate, absorb and store nutrients, and may be the source of secreted digestive enzymes. Type II cells apparently phagocytize and intracellularly digest whole algal cells. The intestine is comprised of relatively unspecialized cells and probably functions primarily as a conductive tube for the elimination of undigested materials.     

Sympathetic nervous control of the iris sphincter of the atlantic cod,Gadus morhua

Summary The autonomic nervous control of the cod iris has been studied. The pharmacological properties of the smooth muscles of the iris have been elucidated by agonist/antagonist studies on isolated strip preparations. Electrical stimulation of parasympathetic and sympathetic pathways to the eye have been carried out, with recordings of the movements of the iris margin. Additions of cholinergic and adrenergic antagonists in selective concentrations were made to investigate the nature of the autonomic nerve fibres controlling the iris.Isolated strip preparations of the iris sphincter contracted in response to cholinergic or-adrenoceptor agonists. There appear to be no radial muscular elements in the cod iris. The effect of carbachol on the iris sphincter could be competitively antagonized by atropine, suggesting the presence of muscarinic receptors of the smooth muscles. The effect of adrenaline was similarly antagonized by phentolamine. The effect of phentolamine, and the order of potency for the adrenergic agonists, shows the presence of-adrenoceptors in the iris sphincter.-adrenoceptors of minor importance are also suggested by the inhibitory effects of isoprenaline on preparations pre-contracted by carbachol.The indirectly acting adrenergic agonist tyramine also contracts the isolated sphincter preparations. This effect is probably due to release of nervously stored catecholamines, since tyramine lacks effect on preparations from animals pre-treated with 6-hydroxydopamine. Preparations from 6-hydroxydopamine pre-treated animals also show a 10-fold increase in the affinity for adrenaline, demonstrating the development of a pre-synaptic supersensitivity due to the destruction of adrenergic nerve terminals of the iris. Stimulation of the sympathetic chain or ciliary nerves produces a constriction of the pupil of the same side. Application of selective concentrations of the antagonists atropine and phentolamine shows that the sympathetic constrictory innervation is solely adrenergic. In some preparations a small pupillo-dilatory effect of nerve stimulation is evident after the constrictory effect has been abolished by phentolamine. This inhibitory effect can be abolished by propranolol, indicating the presence of a-adrenoceptor mediated inhibitory control of minor importance. Stimulation of the oculomotor nerve produces no consistent responses of the cod iris.Illumination of one eye produces a pupilloconstriction comparable to that seen after sympathetic nerve stimulation. The light induced response is insensitive to atropine, phentolamine and tetrodotoxin, showing a direct effect on the smooth muscles of the sphincter. There is no consensual reflex in the cod.I wish to thank Dr. Susanne Holmgren for critically examining the original draft of this paper, and Mrs. Lena Utter for skilled assistance with isolated strip preparations and processing of concentration-response data. The fish was kindly supplied by Mr. Ingmar Hakemar. This work has been supported by grants from the Swedish Natural Science Research Council, the M. Bergvall Foundation and the Adlerbert Foundation.     

Ecological correlates of extra-group paternity in mammals

Extra-group paternity (EGP) can form an important part of the mating system in birds and mammals. However, our present understanding of its extent and ecology comes primarily from birds. Here, we use data from 26 species and phylogenetic comparative methods to explore interspecific variation in EGP in mammals and test prominent ecological hypotheses for this variation. We found extensive EGP (46% of species showed more than 20% EGP), indicating that EGP is likely to play an important role in the mating system and the dynamics of sexual selection in mammals. Variation in EGP was most closely correlated with the length of the mating season. As the length of the mating season increased, EGP declined, suggesting that it is increasingly difficult for males to monopolize their social mates when mating seasons are short and overlap among females in oestrus is likely to be high. EGP was secondarily correlated with the number of females in a breeding group, consistent with the idea that as female clustering increases, males are less able to monopolize individual females. Finally, EGP was not related to social mating system, suggesting that the opportunities for the extra-group fertilizations and the payoffs involved do not consistently vary with social mating system.