Electron microscopic changes in human oesophageal epithelium in oesophagitis

Esophageal Reflux Hypersensitivity: A Comprehensive Review

Reflux hypersensitivity (RH) is one of the phenotypes of gastroesophageal reflux disease. The latest Rome IV defines RH as a condition with typical reflux symptoms and positive reflux-symptom association despite normal acid exposure. Subsequently, the Lyon consensus proposed detailed cutoff values for the criteria on the basis of experts' consensus. Rome IV brought a clear-cut perspective into the pathophysiology of gastroesophageal reflux disease and the importance of esophageal hypersensitivity. This perspective can be supported by the fact that other functional gastrointestinal disorders such as irritable bowel syndrome and functional dyspepsia often overlap with RH. Although several possible pathophysiological mechanisms of esophageal hypersensitivity have been identified, there is still unmet medical needs in terms of treatment for this condition. This review summarizes the current knowledge regarding RH.

Revisiting the Role of Esophageal Mucosal Dilated Intercellular Spaces in the Diagnosis and Pathophysiology of Heartburn

Background/Aims

Dilated intercellular spaces (DISs) facilitate the diffusion of noxious agents into the deep layers of the esophageal epithelium. The role of DIS in heartburn pathogenesis is still controversial. Therefore, we aim to reinvestigate DIS in an extensively evaluated group of patients and healthy controls (HCs).

Methods

We classified 149 subjects into the following groups: 15 HC, 58 mild erosive reflux disease (ERD), 17 severe ERD, 25 nonerosive reflux disease (NERD), 15 reflux hypersensitivity (RH), and 19 functional heartburn (FH). A total of 100 length measurements were performed for each patient's biopsy.

Results

The overall intercellular spaces (ISs) value of gastroesophageal reflux disease (GERD) patients was higher than that of HC (P = 0.020). In phenotypes, mild ERD (vs HC [P = 0.036], NERD [P = 0.004], RH [P = 0.014]) and severe ERD (vs HC [P = 0.002], NERD [P < 0.001], RH [P = 0.001], FH [P = 0.004]) showed significantly higher IS. There was no significant difference between the HC, NERD, RH, and FH groups. The 1.12 μm DIS cutoff value had 63.5% sensitivity and 66.7% specificity in the diagnosis of GERD. There was a weak correlation (r = 0.302) between the IS value and acid exposure time, and a weak correlation (r = -0.359) between the IS value and baseline impedance. A strong correlation was shown between acid exposure time and baseline impedance (r = -0.783).

Conclusions

Since the IS length measurement had better discrimination power only in erosive groups, it is not feasible to use in daily routine to discriminate other nonerosive phenotypes and FH. The role of DIS in heartburn in nonerosive patients should be reconsidered.

Relationship Between Salivary Pepsin Concentration and Esophageal Mucosal Integrity in Patients With Gastroesophageal Reflux Disease

Background/Aims

Increased salivary pepsin could indicate an increase in gastro-esophageal reflux, however, previous studies failed to demonstrate a correlation between salivary pepsin concentrations and 24-hour esophageal acid exposure. This study aims to detect the salivary pepsin and to evaluate the relationship between salivary pepsin concentrations and intercellular spaces (IS) in different gastroesophageal reflux disease phenotypes in patients.

Methods

A total of 45 patients and 11 healthy volunteers were included in this study. All subjects underwent upper gastrointestinal endoscopy, 24-hour ambulatory multichannel impedance-pH (MII-pH) monitoring, and salivary sampling at 3-time points during the 24-hour MII-pH monitoring. IS were measured by transmission electron microscopy, and salivary pepsin concentrations were determined by enzyme-linked immunosorbent assay.

Results

The IS measurements were greater in the esophagitis (EE), non-erosive reflux disease (NERD), and hypersensitive esophagus (HO) groups than in the functional heartburn (FH) and healthy volunteer groups, and significant differences were indicated. Patients with NERD and HO had higher average pepsin concentrations compared with FH patients. A weak correlation was determined between IS and salivary pepsin among patients with NERD (r = 0.669, P = 0.035).

Conclusions

We confirmed the presence of a higher level of salivary pepsin in patients with NERD than in patients with FH. Salivary pepsin concentrations correlated with severity of mucosal integrity impairment in the NERD group. We suggest that in patients with NERD, low levels of salivary pepsin can help identify patients with FH, in addition the higher the pepsin concentration, the more likely the severity of dilated IS.

A standardized method for measuring intercellular spaces in esophageal biopsies in patients with suspected gastroesophageal reflux disease (the intercellular space ratio)

OBJECTIVE

Dilated intercellular space (DIS) in esophageal biopsies is regarded as a possible early sign of mucosal injury in gastroesophageal reflux disease (GERD). This study presents a standardized approach of intercellular space measurement.

MATERIAL AND METHODS

Distal and proximal esophageal biopsies were taken from 19 patients with suspected GERD, and examined with TEM. A grid containing 150 line-crossing points was applied upon each photomicrograph. The number of points falling on the intercellular space was divided by the total number of points of the grid, thereby creating a ratio called the intercellular space ratio (ISR). The ISR method was validated with regard to intra- and interobserver agreement, and was compared to a widely used method for measuring intercellular space diameter developed by Tobey et al. (Tobey NA, Carson JL, Alkiek RA, Orlando RC. Dilated intercellular spaces: a morphological feature of acid reflux-damaged human esophageal epithelium. Gastroenterology 1996;111(5):1200-1205). The ISR was also compared to other markers for GERD. Results. Pearson's correlation coefficients for intra- and interobserver agreement were 0.91 (p < 0.001) and 0.82 (p < 0.001), respectively. The Pearson's correlation coefficient between the ISR and the intercellular space diameter according to Tobey et al., measured in the same micrographs, was 0.32 (p < 0.001). The proximal ISR correlated significantly with the distal ISR (Spearman's rho = 0.57, p = 0.010), and with heartburn symptom score (Spearman's rho = 0.50, p = 0.028).

CONCLUSIONS

The ISR showed a high intraobserver and interobserver agreement. It also displayed good external validity when compared to other markers for gastroesophageal reflux. A rather poor correlation was however found between the ISR and the intercellular space diameter measured as described by Tobey et al.

Pathophysiology of gastro-esophageal reflux disease: a role for mucosa integrity?

BACKGROUND

Gastro-esophageal reflux disease (GERD) is very prevalent and has a high burden on health security system costs. Nevertheless, pathophysiology is complex and not well-understood. Several mechanisms have been proposed: decreased salivation, impaired esophageal clearance, decreased lower esophageal sphincter pressure resting tone, presence of hiatal hernia, increased number of transient lower esophageal sphincter relaxations (TLESRs), increased acid, and pepsin secretion, pyloric incompetence provoking duodeno-gastro-esophageal reflux of bile acids and trypsin. Independent of the relevance of each mechanism, the ultimate phenomenon is that mucosal epithelium is exposed for a longer time to agents as acid and pepsin or is in contact to luminal agents not commonly present in gastric refluxate as trypsin or bile acids. This leads to a visible damage of the epithelium (erosive esophagitis -EE) or impairing mucosal integrity without any sign of macroscopic alteration as occurs in non-erosive reflux disease (NERD). Luminal factors are not the only responsible for such impairment; more recent data indicate that endogenous factors may also play a role.

PURPOSE

This review will update the most recent findings on the putative pathophysiological mechanisms and specially will focus on the role of esophageal mucosal integrity in GERD. Methodologies used for the evaluation of mucosal integrity, its relevance in EE and NERD, its involvement in symptoms perception and the effect of luminal and endogenous factors will be discussed.

Relevance of ultrastructural alterations of intercellular junction morphology in inflamed human esophagus

BACKGROUND/AIMS

Detailed characterization of the ultrastructural morphology of intercellular space in gastroesophageal reflux disease has not been fully studied. We aimed to investigate whether subtle alteration in intercellular space structure and tight junction proteins might differ among patients with gastroesophageal reflux disease.

METHODS

Esophageal biopsies at 5 cm above the gastroesophageal junction were obtained from 6 asymptomatic controls, 10 patients with reflux symptoms but without erosions, and 18 patients with erosions. The biopsies were morphologically evaluated by transmission electron microscopy, and by using immunohistochemistry for tight junction proteins (claudin-1 and claudin-2 proteins).

RESULTS

The expressions of tight junction proteins did not differ between asymptomatic controls and gastroesophageal reflux disease patients. In patients with gastroesophageal reflux disease, altered desmosomal junction morphology was only found in upper stratified squamous epithelium. Dilated intercellular space occurred only in upper stratified squamous epithelium and in patients with erosive esophagitis.

CONCLUSIONS

This study suggests that dilated intercellular space may not be uniformly present inside the esophageal mucosa and predominantly it is located in upper squamous epithelium. Presence of desmosomal junction alterations is associated with increased severity of gastroesophageal reflux disease. Besides dilated intercellular space, subtle changes in ultrastructural morphology of intercellular space allow better identification of inflamed esophageal mucosa relevant to acid reflux.

Overlap of functional dyspepsia and GERD--diagnostic and treatment implications

GERD and functional dyspepsia are the two most prevalent upper gastrointestinal disorders. Gastro-oesophageal reflux is most commonly diagnosed using the cardinal symptoms of heartburn and regurgitation. Patients might also be diagnosed using a questionnaire, after empiric treatment with an acid suppressant, after upper endoscopy or by pH testing. Functional dyspepsia is best diagnosed using symptoms outlined by the Rome committee in conjunction with a normal upper endoscopy. Theoretically, distinguishing these two populations should be easy for all health-care providers. In reality, however, carefully separating out these two populations can be quite difficult, as substantial overlap exists epidemiologically, symptomatically and even diagnostically. This overlap renders precise diagnosis a challenge; given the limited treatment options, the primary goal is to identify those patients who will respond to acid suppressive therapy. Despite the frequency with which functional dyspepsia and GERD overlap, remarkably few studies have investigated this overlap. Most recommendations are based on data derived from separate studies of functional dyspepsia and GERD. A further limitation of existing studies is their failure to differentiate between the various diagnostic categories into which the individual presenting with heartburn might belong.

Gastro-oesophageal reflux disease is associated with up-regulation of desmosomal components in oesophageal mucosa

AIMS

Gastro-oesophageal reflux disease (GERD) is associated with impaired epithelial barrier function. This study was aimed at investigating the role of desmosomal proteins in relation to GERD.

METHODS AND RESULTS

Ninety-five patients with GERD-related symptoms (erosive, n = 51; non-erosive, n = 44) and 27 patients lacking those symptoms were included. Endoscopic and histological characterization of oesophagitis was performed according to the Los Angeles and Ismeil-Beigi criteria, respectively. Multiple biopsies were taken from the oesophageal mucosa of each patient. Gene expression analysis of plakoglobin, desmoglein-1, desmoglein-2 and desmoglein-3 was performed by quantitative real time (RT)-polymerase chain reaction and immunohistochemistry in the oesophageal mucosa. Routine histology revealed specific GERD-related alterations, such as dilatation of intercellular spaces (DIS), basal cell hyperplasia (BCH), and elongation of the papillae, in the oesophageal mucosa of patients with GERD, as compared with controls (all parameters: P < 0.05). All four genes and corresponding proteins were found to be up-regulated by between 1.7 and 8.1-fold (transcript level, P < 0.05; protein level, P < 0.05). Induced gene expression levels of plakoglobin, desmoglein-1 and desmoglein-2 correlated significantly with DIS and BCH.

CONCLUSIONS

Taken together, the uniform up-regulation of desmosomal genes/proteins in the oesophageal mucosa of patients with GERD supports the concept of architectural and molecular changes in the desmosomal compartment in the pathogenesis of GERD.

Comparison of central and intraesophageal factors between gastroesophageal reflux disease (GERD) patients and those with GERD-related noncardiac chest pain

Gastroesophageal reflux disease (GERD) causes a wide range of symptoms. Some patients present with typical symptoms such as heartburn and regurgitation and others with atypical symptoms such as chest pain. The mechanism responsible for the varying clinical presentation of GERD is still not fully elucidated. The aim of this study was to prospectively evaluate differences in central and local intraesophageal factors between patients with typical GERD symptoms and those with noncardiac chest pain (NCCP). Patients presenting with typical and atypical symptoms suspicious of GERD underwent upper endoscopy and 24-hour pH monitoring with four sensors, each positioned at a different esophageal level. All patients completed GERD symptom, Hospital Anxiety and Depression Scale, and Symptom Stress Rating questionnaires. From January 2006 to December 2009, 50 patients were recruited, 29 with typical symptoms, and 21 with NCCP. Patients with proven GERD and NCCP had higher proximal extension of acid during reflux episodes than patients with typical symptoms. They were found to be older, had a shorter history of symptom onset, worse anxiety scores, and more endoscopic findings compatible with gastritis. Proximal extension of acid during the reflux episodes in patients with GERD presenting with NCCP may play a role in symptom generation.

Gastroesophageal reflux disease--from reflux episodes to mucosal inflammation

Gastroesophageal reflux disease (GERD) affects 20-30% of the population in Western countries, and is one of the most common clinical problems in daily practice. GERD-associated functional and structural abnormalities are caused by recurrent exposure of the esophagus to acidic and nonacidic refluxate of gastric contents (containing duodenal and intestinal proteases as well as acid and gastric pepsin) from the stomach. Major progress has been made in the understanding of the molecular pathogenesis of GERD-associated mucosal inflammation, suggesting a complex and multifactorial pathogenesis and immune-mediated effects. This Review summarizes the complexity of mucosal pathogenesis, including microscopic changes, mucosal inflammation and GERD-specific molecular mediators, in the context of the clinical features and pathophysiological characteristics of GERD. The abnormal exposure of the esophagus to luminal contents leads to chronic mucosal inflammation that is characterized by the release of IL-8 specifically, as well as other proinflammatory mediators, from the esophageal mucosa. Evidence from animal studies indicates a stepwise inflammatory response by the epithelium, which attracts immune effector cells to infiltrate the mucosa. From bench to bedside, these novel molecular findings might provide new treatment options beyond current acid-suppressive therapy and the principle of inhibition of transient lower esophageal sphincter relaxation.

Intercellular space volume is mainly increased in the basal layer of esophageal squamous epithelium in patients with GERD

BACKGROUND/AIMS

At present, the dilation of esophageal intercellular spaces (ICS) is considered an early morphologic marker of acid damage in patients with GERD. Nevertheless, previous electron microscopic (EM) studies had focused only on the suprabasal layer of squamous epithelium or did not nearly specify which layer of squamous epithelium was studied. Therefore, we aimed to assess the volumetric amount of the ICS in all layers of SE in patients with GERD.

METHODS

In this study, 48 patients were prospectively included (NERD = 18, ERD = 17; Barrett's esophagus = 5, controls = 8). All patients with ERD and NERD had typical reflux symptoms, as assessed by a valid GERD questionnaire. ICS volume was assessed by electron microscopy in the superficial, prickle cell, and basal layers of esophageal squamous epithelium using the method of Weibel.

RESULTS

ERD was associated with increased ICS volume in the basal layer (LA-A, p = 0.038; LA-B, p = 0.005) and prickle cell layer (LA-A, p = 0.006; LA-B, p = 0.007) as compared to controls. Comparisons between NERD and ERD patients revealed more dilated ICS in the basal layer (LA-B, p = 0.007), prickle cell layer (LA-A, p = 0.008; LA-B, p = 0.001) and superficial layer (LA-B, p = 0.018) in patients with ERD.

CONCLUSIONS

Not only the diameter but also the volume of the ICS is increased in patients with GERD. Furthermore, the dilation of ICS is present in all three layers of the SE, being more pronounced in the basal layer. These findings support the concept that the impairment of the esophagus begins in the deeper parts of the esophageal epithelium.

The pathogenesis of Barrett's metaplasia and the progression to esophageal adenocarcinoma

The most important risk factor for the development of Barrett's esophagus is the reflux of both gastric and duodenal contents into the esophagus. The reason why Barrett's metaplasia develops only in a minority of patients suffering from gastroesophageal reflux disease remains unknown.The exact mechanism behind the transition of normal squamous epithelium into specialized columnar epithelium is also unclear. It is likely that stem cells are involved in this metaplastic change, as they are the only permanent residents of the epithelium. Several tumorigenic steps that lead to the underlying genetic instability, which is indispensable in the progression from columnar metaplasia to esophageal adenocarcinoma have been described. This review outlines the process of pathogenesis of Barrett's metaplasia and its progression to esophageal adenocarcinoma.

Overlap of Erosive and Non-erosive Reflux Diseases With Functional Gastrointestinal Disorders According to Rome III Criteria

Background/Aims

Gastroesophageal reflux disease (GERD) is increasing in Asian countries. Functional dyspepsia (FD) or irritable bowel syndrome (IBS) are also prevalent and commonly overlapped with GERD. This study was conducted to compare the proportion and risk factors for overlapping reflux esophagitis (RE) and non-erosive reflux disease (NERD) with functional gastrointestinal disorders (FGIDs).

Methods

A total of 2,388 [male, 55.9%; mean age (± SD), 43.2 years (± 8.4)] Korean subjects who underwent the upper endoscopy for health screening were prospectively included. The subjects were asked about demographic, medical and social history by using a structured questionnaire, and FD and IBS were assessed according to the Rome III criteria.

Results

The subjects with RE were 286 (12.0%, male 88.5%, 42.8 years) and 74 subjects had NERD (3.1%) while the prevalence of FD and IBS were 8.1% and 10.1%, respectively. The proportion of FD and IBS in NERD was higher than that of RE (74.3% vs. 10.5%, p = 0.000; 41.9% vs. 11.2%, p = 0.000, respectively). The epigastric pain syndrome (EPS) was more prevalent than postprandial distress syndrome in NERD. According to multiple regression analysis, high somatization score and the presence of FD increased the odd ratio for NERD. However, male gender and current smoker were significant risk factors for RE.

Conclusions

Compared to RE, NERD is more frequently overlapped with FD, especially EPS, and also are associated with significantly increased frequency of IBS. Our data draws attention to the possibility of subgrouping FGIDs and GERD to be important in understanding the pathophysiology of these conditions.

Factors influencing intercellular spaces in the rat esophageal epithelium

AIM: To evaluate the effect of acute stress, hydrochloric acid, ethanol, aspirin, and prednisolone on the intercellular spaces of the esophageal epithelium.

METHODS: Part I, male Sprague-Dawley rats were randomly divided into eight groups and treated with the damaging or control factors. The esophagus of each rat was macroscopically inspected. Histological changes in mucosal biopsies were examined by light microscopy, and the widths of intercellular spaces were determined by transmission electron microscopy (TEM). Part II, in part I, we found that acute stress and aspirin induced dilated intercellular spaces (DIS) of the esophageal epithelium. Therefore, the effect of acid suppression pretreatment with esomeprazole on esophageal epithelial DIS induced by water immersion and restraint stress (WRS) and aspirin was further investigated to determine the association of DIS with acid reflux. After administration of 0.9% sodium chloride solution or esomeprazole solution orally for five days, rats underwent WRS or intragastric administration of aspirin solution. Esophageal epithelial intercellular spaces were investigated by TEM.

RESULTS: (1) The five damaging factors produced no lesions or inflammation in esophageal mucosa of rats under either gross or routine histological inspections. Esophageal epithelial intercellular space diameters in stress and aspirin groups were significantly greater, nearly three or two-fold respectively, than those in their corresponding control groups (stress model: 0.38 ± 0.05 μm vs 0.13 ± 0.02 μm, P < 0.01; aspirin model: 0.32 ± 0.12 μm vs 0.19 ± 0.05 μm, P < 0.01). Neither intragastric administration of hydrochloric acid or ethanol, nor hypodermic injection of prednisolone produced DIS compared with their corresponding control groups (hydrochloric acid model: 0.24 ± 0.03 μm vs 0.19 ± 0.05 μm, P > 0.05; ethanol model: 0.25 ± 0.10 μm vs 0.19 ± 0.05 μm, P > 0.05; prednisolone model: 0.20 ± 0.03 μm vs 0.14 ± 0.03 μm, P > 0.05); and (2) No significant difference in the intercellular space diameters was observed between the group pretreated with esomeprazole and the control group, in both the stress and aspirin models (stress model: 0.35 ± 0.05 μm vs 0.37 ± 0.05 μm, P > 0.05; aspirin model: 0.24 ± 0.02 μm vs 0.27 ± 0.03 μm, P > 0.05).

CONCLUSION: Acute stress and aspirin can induce DIS of the esophageal epithelium in rats, and it is not correlated with acid reflux.

Dilated intercellular spaces as a marker of GERD

Gastroesophageal reflux disease (GERD) is typically heralded by the substernal burning pain of heartburn. On endoscopic examination, about one third of GERD subjects with heartburn have erosive disease, and the remainder have nonerosive reflux disease (NERD). Unlike patients with erosive disease, those with NERD (approximately 50%) often do not respond to therapy with proton pump inhibitors (PPIs), raising the question of whether they have NERD and, if they do, whether the cause of their symptoms is similar to those who respond to PPIs. Recently, biopsies established that subjects with heartburn and PPI-responsive NERD, like those with erosive esophagitis, have lesions within the esophageal epithelium known as dilated intercellular space (DIS). In this article, we discuss the physicochemical basis for DIS in acid-injured esophageal epithelium and its significance in GERD. Although DIS is not pathognomic of GERD, it is a marker of a break in the epithelial (junctional) barrier reflecting an increase in paracellular permeability.

Diagnosing gastroesophageal reflux disease: the pathologist's perspective

Gastroesophageal reflux disease (GERD) is a common disease frequently encountered by surgical pathologists. Although the pathogenesis and clinical features of the disease have been studied for years, many unanswered questions remain. Typical clinical symptoms along with the endoscopic findings, pH monitoring, and biopsies, all support the diagnosis. However, these tests may yield conflicting findings, and at present there is no gold standard for the diagnosis of GERD. In patients with normal or nearly normal endoscopic findings (nonerosive reflux disease), the major diagnostic burden lies with the histology. The histologic diagnosis of GERD is based on a combination of findings, including basal cell hyperplasia, papilla elongation, inflammation, and dilatation of intercellular spaces. However, these features exhibit varying sensitivity and specificity, and minimal biopsy criteria for the diagnosis of reflux esophagitis have not been rigorously tested in well-characterized patient populations. However, given the high prevalence of GERD, pathologists face esophageal mucosal biopsies daily and must recognize the diagnostic strengths and limitations of histologic features of reflux esophagitis. Future studies and new techniques may improve the diagnostic strength of histology and establish meaningful minimal criteria for the diagnosis of reflux esophagitis.

Experimental oesophagitis in the rat is associated with decreased voluntary movement

Growing interest has arisen regarding the mechanism of dyspeptic symptom generation. However, no evaluation system of these symptoms in animals has been developed. In this study, we examined whether voluntary movement of rats could be a measure to assess visceral symptoms of reflux oesophagitis. A chronic acid reflux oesophagitis model was made using rats, and the size of erosions was measured. Omeprazole was administered to the oesophagitis rats for 10 days. The amount of voluntary movement was measured by an infrared sensor. Intracellular spaces in oesophageal epithelium were also measured using a emission electron microscope. NP-40 soluble and insoluble fractions of claudins were examined by Western blot. Voluntary movement was significantly lower in the oesophagitis model rats than in the sham-operated rats (P < 0.01). Although omeprazole reduced the size of erosions, it did not significantly affect the total amount of voluntary movement (r = -0.033, P = 0.916). Intracellular spaces were significantly dilated in the oesophagitis model rats and claudin-3 showed a significantly lower relative quantity in the NP-40 insoluble fraction. Omeprazole significantly increased voluntary movement of oesophagitis model rats and the relative quantity of claudin-3 in the insoluble fraction (P < 0.05). Dilated intercellular spaces and the lower level of claudin-3 may relate to the voluntary movement of oesophagitis model rats. Decreases in voluntary movement of oesophagitis model rats may reflect visceral symptoms and be able to serve as an index of chronic abdominal symptoms.

Comparison of histological parameters for the diagnosis of eosinophilic oesophagitis versus gastro-oesophageal reflux disease on oesophageal biopsy material

AIMS

Eosinophil infiltration of the oesophageal epithelium is the cardinal pathomorphological finding in eosinophilic oesophagitis (EO), but gastro-oesophageal reflux disease (GORD) is also associated with increased eosinophils. The aim was to compare histological parameters for the diagnosis of EO versus GORD on routinely taken biopsy specimens.

METHODS AND RESULTS

One hundred and five routine biopsy specimens with EO (n = 62), GORD (n = 24) and probable EO (n = 19) from 74 patients (52 men, 22 women; mean age 43.7 years) were analysed for numbers of eosinophils, mast cells, degranulation and qualitative changes of oesophageal epithelium using immunohistochemistry with monoclonal antibodies against eosinophil peroxidase and eosinophil major basic protein and mast cell tryptase. Eosinophil infiltration was significantly higher in EO than in GORD both on haematoxylin and eosin staining (54.8 versus 9.1; P < 0.05) and immunohistochemistry (77.5 versus 24.7; P < 0.05). Eosinophil degranulation was significantly more intense in EO than in GORD (1.16 versus 0.41; P < 0.05). Furthermore, eosinophilia-codependent secondary qualitative changes of squamous epithelium in EO were generally more extensive than those in GORD.

CONCLUSIONS

Histological differential diagnosis of EO and GORD should be based on eosinophil counts, secondary morphological changes of eosinophils and oesophageal squamous epithelium, especially in cases suspicious of EO.

Mechanisms of heartburn

Heartburn is a typical symptom of GERD. The spectrum of diseases associated with GERD includes reflux esophagitis, Barrett's esophagus and nonerosive reflux disease (NERD). Although acid reflux is the classic cause of heartburn in patients with erosive esophagitis, the relationship between acid and heartburn is far from clear, especially in patients with NERD. Strong evidence exists that weakly acidic reflux and/or non-acid-related events have a significant role in the generation of heartburn. In addition to the role of nonacidic refluxate components, activation of mechanoreceptors and chemoreceptors, and a possible role for central and peripheral sensitization, has been described. Although patients with erosive esophagitis respond well to acid-suppressive therapy, the same does not hold true for those with NERD. NERD represents a major clinical problem, and its management remains a challenge. Discussion of NERD focuses on the mechanisms that cause chest pain in this subgroup of patients. Improved understanding of the pathogenesis underlying heartburn in patients with GERD, in particular those with NERD, will shape our understanding of this condition. Such understanding will serve as a platform for further research and allow additional therapies to be developed for this increasingly encountered clinical condition.

Physicochemical basis for dilated intercellular spaces in non-erosive acid-damaged rabbit esophageal epithelium

Dilated intercellular spaces (DIS) within esophageal epithelium (EE) is a histopathologic feature of non-erosive reflux disease and early lesion in acid-damaged rabbit EE associated with increased paracellular permeability. Its cause remains unknown, but the lesion's morphology suggests a significant fluid shift into the intercellular spaces (ICS). Since water follows osmotic forces and consequently ion movements, we explored the role of active (ion) transport and ion gradients in its pathogenesis. This was done by quantifying the effect of inhibited active transport and altered ion gradients on electrical resistance (R(T)) and ICS diameter in acid-exposed Ussing-chambered rabbit EE. Compared with normal Ringer, pH 7.5, 30 minutes of luminal HCl (100 mmol/L), pH 1.1, increased permeability (R(T): +5 +/- 4% vs-52 +/- 4%) and ICS diameter (0.25 +/- 0.01 microm vs 0.42 +/- 0.02 microm), but had no effect on cell morphology or diameter. Ouabain pretreatment significantly reduced active transport but had no effect on the acid-induced changes. However, negating the chloride gradient created by luminal HCl either by adding choline chloride, 100 mmol/L, serosally or by replacing luminal HCl, pH 1.1, with luminal H(2)SO(4), pH 1.1, prevented the development of DIS while maintaining the increase in permeability. DIS was also prevented in the presence of a 100 mmol/L (choline) chloride gradient by luminal exposure at neutral pH. DIS in HCl-damaged EE is caused by an H(+)-induced increase in epithelial permeability; this enables Cl(-) to diffuse along its gradient into the ICS, creating an osmotic force for water movement into and (hydrostatic) dilation of the ICS.

A pilot study of efficacy and safety of continuous intravenous infusion of pantoprazole in the treatment of severe erosive esophagitis

BACKGROUND AND OBJECTIVES

Reflux esophagitis is a common disease. Erosive reflux esophagitis is a more advanced stage of reflux esophagitis. Although death from reflux disease is uncommon, significant morbidity and mortality from complications, such as esophageal ulcer, stricture, and cancer, are not uncommon. Proton pump inhibitors are the popular medication for reflux esophagitis. The objective of this study was to determine the efficacy and safety of continuous intravenous infusion of pantoprazole in the treatment of severe erosive esophagitis.

METHODS

From February 2005 to November 2006, all patients with grade 4 erosive reflux esophagitis were screened for the study. Eligible patients were randomized into two groups. Each patient in the study group received intravenous pantoprazole 80 mg loading dose over 5 min, followed by 8 mg/h intravenous infusion for 72 h, then 40 mg orally once a day for 4 days. Each patient in the control group received 40 mg pantoprazole intravenously once a day for 72 h, then orally once a day for 4 days. A second endoscopic gastrointestinal examination (EGD) was performed on treatment days 6-8 (+/-1 day if day 7 was on a weekend) to document any healing of esophagitis in either the study or the control group.

RESULTS

In the study group, severe erosive esophagitis healed completely in three patients and significantly in the other three by the time of the second endoscopy. In the control group, severe erosive esophagitis healed partially in five patients, and no improvement was seen at all in one patient by the time of second endoscopy. The difference in the intervention between those two groups was statistically different (P = 0.015). There were no significant complications in either group.

CONCLUSIONS

Severe erosive esophagitis can be completely healed in a few days if pantoprazole is given intravenously and continuously for 72 h. It is safe to give pantoprazole intravenously and continuously for treatment of severe erosive esophagitis.

Nonerosive reflux disease: a pathophysiologic perspective

Nonerosive reflux disease (NERD) is the most common phenotype of gastroesophageal reflux disease. By definition, patients with NERD have typical reflux symptoms caused by the intraesophageal reflux of gastric contents but have no visible esophageal mucosal injury. This is in contrast to patients with reflux esophagitis, also known as erosive reflux disease, and Barrett's esophagus, who have obvious esophageal mucosal injury on endoscopy. Only 50% of patients with NERD have pathologic esophageal acid contact time (ACT) as detected on 24-hour pH monitoring (ie, NERD-positive). NERD patients with physiologic esophageal ACT and good temporal correlation of symptoms with reflux events (symptom index > 50% or symptom-association probability > 95%) are considered to have esophageal hypersensitivity (ie, NERD-negative). Finally, patients with physiologic esophageal ACT but poor symptom-reflux correlation are now considered to have functional heartburn and not NERD. NERD-positive patients have motor dysfunction and acidic reflux abnormalities that are similar to patients with reflux esophagitis and Barrett's esophagus, whereas NERD-negative patients have minimal abnormalities that are not much different than healthy controls. The histopathologic feature most indicative of NERD is the presence of dilated intercellular spaces within squamous epithelium, an ultrastructural abnormality readily identified on transmission electron microscopy and on light microscopy.

Esophageal dilated intercellular spaces (DIS) and nonerosive reflux disease

Esophageal mucosal dilated intercellular spaces (DIS) are frequently observed in patients with nonerosive reflux disease (NERD) and patients with esophagitis. The specificity of DIS is questionable, as it is present in up to 30% of asymptomatic healthy subjects and in patients with other esophageal disorders. DIS occurs in parallel with a drop in potential difference, diminished transepithelial resistance, and increased esophageal mucosal permeability. These alterations arise with exposure to acid and pepsin during gastroesophageal reflux, but the exact pathway of damage to the intercellular junctions remains unclear and seems to be multifactorial. Other noxious contents of the refluxate, such as bile acids, are harmful and DIS can also be induced by acute psychological stress. DIS can be assessed quantitatively with electron microscopy (EM), but it is also recognizable with light microscopy (LM). DIS can disappear after treatment with proton pump inhibitors (PPI); however, this is not the case in all NERD patients. A recent study showed that patients with NERD who are refractory to PPI might still have DIS; and animal experiments showed that persistence of DIS might be due to esophageal mucosal exposure to bile acids and/or psychological stress. In conclusion, DIS is a frequent but nonspecific histological feature of NERD. It can be caused by acid reflux, but bile acids in the refluxate and/or psychological stress can modulate the development or persistence of DIS. Although a causal relationship between DIS and heartburn has been proposed, it still needs to be proven and the underlying mechanisms investigated before considering DIS as a target for treatment of NERD.

Dilation of intercellular spaces is associated with laryngo-pharyngeal reflux: an ultrastructural morphometric analysis of laryngeal epithelium

Gastroesophageal reflux disease (GERD) can be associated with ear, nose, and throat signs and symptoms, a condition often referred to as laryngopharyngeal reflux (LPR). However, the morphologic alterations of laryngeal mucosa associated with LPR are currently poorly understood. Since the dilation of intercellular spaces (DIS) between squamous epithelial cells is considered a morphologic marker of acid damage to esophageal mucosa in GERD, we evaluated whether similar changes can be detected in the laryngeal epithelium of patients affected by LPR. The study group included 15 patients affected by LPR and 7 normal controls, who underwent laryngeal biopsies at the interarytenoid area. Specimens were routinely processed for light microscopic and ultrastructural examination. The intercellular spaces were measured in electron microscopy images using a computer assisted morphometric system. Ultrastructural analysis demonstrated an irregular intercellular space dilation in specimens from the group of patients with LPR. Another ultrastructural abnormality observed in a minority of patients was the presence of numerous cytoplasmic vacuoles. Computer assisted morphometric analysis demonstrated that the intercellular space between squamous cells was significantly wider in patients with LPR than in control subjects (411.7 nm +/- 188.6 SD vs. 155.8 nm +/- 56.4 SD, P = 0.003). These data indicate that ultrastructural evidence of DIS of epithelial cells may be a morphologic marker of acid reflux, as already described in esophageal mucosa. If this result will be confirmed in larger series it may provide a useful diagnostic tool for the identification of LPR.

Increased esophageal sensitivity to acid and saline in patients with nonerosive gastro-esophageal reflux disease

GOALS

To investigate the features of nonerosive reflux disease (NERD).

BACKGROUND

NERD is not considered as a milder form of erosive gastro-esophageal reflux disease (eGERD). Although the prevalence of NERD was reported to be high in our country, there have been very few studies about NERD.

STUDY

We performed upper gastrointestinal endoscopy to confirm the diagnosis of GERD. The modified acid perfusion test and saline perfusion test were performed in 7 control subjects, 14 NERD, and 11 eGERD patients. The stimulus-response function to acid and saline was quantified by the duration of typical symptom perception (minutes), total sensory intensity rating (0 to 10), and the perfusion sensory score (SS), which was defined as the product of minutes and the sensory intensity rating.

RESULTS

The mean value of SS by saline was 0 in control subjects, 12.0 in NERD patients, and 1.5 in eGERD patients (P<0.01 control vs. NERD, P<0.01 NERD vs. eGERD). The mean SS with acid was 0.9 in control subjects, 52.5 in NERD patients, and 23.0 in eGERD patients (P<0.01 control vs. NERD, control vs. eGERD, P<0.05 NERD vs. eGERD). A statistically significant association was shown between the acid and saline perfusion SSs with a correlation coefficient value of r=0.57 in the NERD group (P<0.05).

CONCLUSIONS

Both eGERD and NERD, but especially NERD, exhibited esophageal hypersensitivity not only to acid but also saline perfusion, suggesting that hyperalgesia to acid and other factors (eg, psychologic and/or autonomic nerve disturbance) may play some roles in symptom generation in NERD.

Non-erosive reflux disease, functional heartburn and gastroesophageal reflux disease; insights into pathophysiology and clinical presentation

Non-erosive reflux disease (NERD) has emerged as a real entity in the spectrum of gastroesophageal reflux disease (GERD) and may, indeed, represent the most common manifestation of reflux disease. Recent information indicates NERD can be further subclassified based on the results of pH studies and suggests that functional heartburn needs to be differentiated as that subgroup of patients in which there appears to be no relationship between symptoms, however 'typical' of GERD, and acid exposure. Other aspects of NERD need to be appreciated, including overlap with functional dyspepsia and the potential variations in response to such therapeutic interventions as acid-suppressive therapy and fundoplication. It seems quite possible that our failure to separate functional heartburn from NERD, in general, has contributed, in large measure, to diagnostic difficulties and therapeutic disappointment in GERD. An appreciation of the range of entities, of different etiology and pathology, within NERD will foster the development of effective approaches to the assessment and therapy of this challenging disorder.

Review article: the nature of oesophageal injury in gastro-oesophageal reflux disease

The purpose of this review was to explore issues relating to the nature of oesophageal injury in gastro-oesophageal reflux disease. Several structural and functional elements of the oesophageal epithelium provide for an inherent resistance against refluxed material. It is only when this defence is overcome that reflux-induced damage ensues. The light microscopic changes in reflux oesophagitis are manifold. Early changes are confined to the epithelium and consist of reactive changes and inflammatory cell infiltration. When the epithelial integrity can no longer be maintained, erosions and ulcers develop. Recently, dilatation of the intercellular spaces was described as a sensitive early marker for gastro-oesophageal reflux disease. This parameter was first identified by electron microscopy but can also be assessed by light microscopy in routinely stained tissue sections. Some of the changes occurring in early gastro-oesophageal reflux disease can be reproduced by incubating oesophageal mucosal biopsies in gastrointestinal fluids or their components. Activated pepsin, trypsin and conjugated bile acids at an acidic pH have been identified as probable causes of reflux-induced damage.

Clinical consequences of silent gastroesophageal reflux disease

Silent gastroesophageal reflux disease (GERD) is a very common phenomenon that involves the incidental finding of erosive esophagitis, Barrett's esophagus, and the evolution of esophageal adenocarcinoma in asymptomatic patients. The reasons for having advanced GERD without clearly identifiable symptoms are poorly understood, primarily due to lack of recognition of this important phenomenon. The clinical implications of silent GERD are vast and should provide the impetus for further research into this group of patients. Recent studies have suggested that sleep disturbances and poor quality of sleep could be the needed clues to identify individuals with silent GERD.

Dilated intercellular spaces: a major morphological feature of esophagitis

OBJECTIVES

Dilated intercellular spaces (DIS) in the esophageal epithelium have been identified by electron microscopy as marker of acid reflux damage in experimental animals and adults with gastroesophageal reflux disease (GERD). We aimed to identify and quantify DIS by light microscopy in pediatric GERD and esophagitis.

METHODS

We prospectively took esophageal biopsies in 70 consecutive pediatric patients, 48 of whom had GERD symptoms. On hematoxylin and eosin-stained sections esophagitis was scored histologically, and DIS were graded as 0 (absent), + (small and focal), ++ (moderate) or +++ (large and diffuse). A computerized image analysis identified total, cellular and nuclear areas and DIS were quantified as percentage of total minus cellular area.

RESULTS

Forty of 48 GERD patients had histological esophagitis (33 G1, 4 G2, 3 G3, 1 of which with Barrett esophagus), and all 40 had DIS (33 +, 4 ++, 3 +++) with 100% interobserver agreement; 15 of 29 (55%) had abnormal pH study (reflux index, 5.7%-36%). In 30 patients the esophagus was histologically normal. DIS values were 2.21% +/- 2.60% (range, 0.11%-12%) in patients with esophagitis and 0.44% +/- 0.13% (0.2%-0.7%) in patients with normal histology (P < 0.00001), with 0.71% bearing 70% sensitivity and 100% specificity for GERD versus controls. Five other children with esophagitis unrelated to GERD (eosinophilic, Candida, food allergy) also had DIS + to +++, and median DIS area was 5% (1.3%-12%).

CONCLUSIONS

DIS can be detected and evaluated by light microscopy, and the image analysis used provides an objective quantification of DIS and supports the light microscopy evaluation. DIS are a morphological feature of GERD and esophagitis in infancy and childhood.

Dilated intercellular spaces as a marker of oesophageal damage: comparative results in gastro-oesophageal reflux disease with or without bile reflux

BACKGROUND

The dilation of oesophageal intercellular spaces, clearly apparent in transmission electron microscopy images, is a marker of cellular damage induced by acid.

AIM

To analyse the presence of dilated intercellular spaces and to quantify the scores in controls and in patients with gastro-oesophageal reflux disease or duodenal gastro-oesophageal reflux accompanied by erosive or non-erosive reflux disease.

METHODS

Thirty-eight symptomatic patients with gastro-oesophageal reflux disease or duodenal gastro-oesophageal reflux and 12 asymptomatic controls, classified on the basis of pH-metry and bilimetry, underwent endoscopy. Six tissue biopsies were taken from the normal mucosa for light microscopy and transmission electron microscopy evaluation. Dilated intercellular spaces were measured on photomicrographs of the specimens (at least 100 transects were measured for each patient).

RESULTS

Twenty-two patients with gastro-oesophageal reflux disease had normal macroscopic mucosa but, at histology, five patients with erosive gastro-oesophageal reflux disease had mild oesophagitis and one had moderate oesophagitis. Seven patients with duodenal gastro-oesophageal reflux had normal mucosa, whilst three with erosive duodenal gastro-oesophageal reflux had mild oesophagitis at histology. At transmission electron microscopy, all controls had dilated intercellular spaces of less than 1.69 microm. Each symptomatic patient had a mean dilated intercellular space value and a mean value of the maximum dilated intercellular space at least three or more times greater than that in controls (P < 0.001). No statistical differences were observed between erosive and non-erosive oesophagitis.

CONCLUSIONS

The dilated intercellular space is an extremely sensitive marker of damage in gastro-oesophageal reflux disease, duodenal gastro-oesophageal reflux and non-erosive reflux disease, and serves as the most appropriate marker of damage evaluation in non-erosive reflux disease reported to date. A mean dilated intercellular space of 0.74 micro m provides a cut-off score for damage. No quantitative or qualitative differences in dilated intercellular space scores were found between pure and mixed acid reflux.

Cell biology of laryngeal epithelial defenses in health and disease: further studies

This is the second annual report of an international collaborative research group that is examining the cellular impact of laryngopharyngeal reflux (LPR) on laryngeal epithelium. The results of clinical and experimental studies are presented. Carbonic anhydrase (CA), E-cadherin, and MUC gene expression were analyzed in patients with LPR, in controls, and in an in vitro model. In patients with LPR, we found decreased levels of CAIII in vocal fold epithelium and increased levels in posterior commissure epithelium. The experimental studies confirm that laryngeal CAIII is depleted in response to reflux. Also, cell damage does occur well above pH 4.0. In addition, E-cadherin (transmembrane cell surface molecules, which have a key function in epithelial cell adhesion) was not present in 37% of the LPR laryngeal specimens. In conclusion, the laryngeal epithelium lacks defenses comparable to those in esophageal epithelium, and these differences may contribute to the increased susceptibility of laryngeal epithelium to reflux-related injury.

Epidemiology and pathophysiology of symptomatic gastroesophageal reflux disease

Symptomatic, or nonerosive, gastroesophageal reflux disease (GERD) is the most common presentation of GERD. Patients with symptomatic GERD more frequently are younger, female, weigh less, and are less likely to have a hiatal hernia compared with patients who have erosive GERD. Physiologically, these patients demonstrate minimal esophageal motor abnormalities. However, despite a common clinical presentation and similar endoscopic findings, symptomatic GERD is comprised of a heterogeneous group of patients. There are several identifiable subgroups differentiated by the underlying mechanisms causing their heartburn symptoms, distinctions that may explain the relatively low symptom response rate to potent antireflux treatment observed among these patients as compared with those with erosive esophagitis.

Nonerosive reflux disease--current concepts and dilemmas

Nonerosive reflux disease is defined as the presence of typical symptoms of gastroesophageal reflux disease caused by intraesophageal acid in the absence of visible esophageal mucosal injury at endoscopy. Recent studies demonstrate that it is a chronic disease with a significant impact on quality of life, and it is very common in primary care settings. Treatment with acid inhibitory agents is effective, and proton pump inhibitors are the most effective form of therapy.

Morphological alterations in tryptic esophagitis: an experimental light microscopic and scanning and transmission electron microscopic study in rabbits

The morphology of esophageal mucosal damage induced by trypsin was investigated in an experimental model, where the rabbit esophagus was perfused in situ with a control solution (physiologic NaCl) and trypsin (1 mg/ml). The results indicate that trypsin has an adverse effect on esophageal mucosa. In light microscopy infiltration of leucocytes in the submucosa and later ulcerative changes in the mucosa were seen. Scanning electron microscopy showed detachment of superficial cells and later deeper lesions, displaying denuted intramucosal collagen bundles with erythrocytes. In transmission electron microscopy significant widening of the intercellular spaces could be seen. This suggests that in clinical situations trypsin refluxed from duodenum into stomach and further to esophagus has an adverse effect on esophageal mucosa and may have importance in the pathogenesis of clinical reflux esophagitis. Because of the relatively high pH-optimum trypsin may have importance only under nonacidic or alkaline conditions.

Expression of MHC Class II antigens by oesophageal epithelium in herpes simplex oesophagitis

An immunoperoxidase technique with monoclonal antibodies for the identification of lymphocyte subsets and MHC Class II antigens was applied to oesophageal biopsies from two patients with herpetic oesophagitis. Oesophageal epithelial cells were found to express the MHC Class II antigen. The inflammatory infiltrate of the lamina propria was composed of both B lymphocytes and T lymphocytes.

Morphological alterations in experimental esophagitis. Light microscopic and scanning and transmission electron microscopic study

The morphology of esophagitis, both in the presence and absence of acid, was studied by light microscopy and transmission and scanning electron microscopy. For this purpose the rabbit esophagus was isolated in situ and perfused with agents known to cause esophageal mucosal damage (HCl, pepsin, taurocholate, and deoxycholate). In addition, changes in the permeability of the plasma membrane of the esophageal epithelial cells were assessed by staining the esophageal epithelium with trypan blue and antinuclear antibodies. The results indicate that HCl alone causes relatively few changes in the esophageal epithelium. However, when combined with pepsin or taurocholate, severe ulcerative changes were caused within an hour. Deoxycholate, which is formed in the upper gastrointestinal tract under nonacidic conditions, also causes severe damage. Further, it was shown that the esophagitis caused by pepsin and bile salts are clearly morphologically different. Bile salts affect primarily the cell membrane and intracellular organelles, while pepsin seems to affect the intercellular substance causing the epithelial cells to be shed. In contrast, the presence or absence of acid per se does not seem to influence the nature of the epithelial damage, since the lesions caused by the two bile salts (deoxycholate vs taurocholate + HCl) were morphologically similar.

Lymphocytes and Langerhans cells in the human oesophageal epithelium

Using monoclonal antibodies on fresh frozen endoscopically obtained oesophageal biopsies the distribution of Langerhans cells, B lymphocytes, and various subpopulations of T lymphocytes was studied in the normal human oesophageal mucosa and in oesophagitis. Identification of the lymphocytes was carried out by an immunoperoxidase technique using OKT3 (antihuman T cell antibody), OKT4 (antihuman helper T cell antibody), OKT8 (antihuman cytotoxic T cell) and OKT10 (antihuman null cell antibody). Identification of the Langerhans cells was carried out using an ATPase stain and OKIa (Ia like antigen) and OKT6 (antihuman thymocyte). In the normal oesophageal epithelium cytotoxic T lymphocytes are found as well as Ia positive Langerhans cells. Helper T lymphocytes and B lymphocytes are present mainly in the lamina propria. In oesophagitis an increase in Langerhans cells and cytotoxic T lymphocytes within the epithelium is found. From these findings it can be concluded that the oesophagus contains a reticuloepithelial system as well as a lymphocytic population which are a part of the gut-associated lymphoid tissue.

Transmission electron microscopy of human oesophageal carcinomas

Twelve human oesophageal carcinoma samples were examined by both light and electron microscopy in order to characterise the ultrastructural features of this neoplasm. Those samples from well differentiated tumours contained abundant tonofilaments, mainly in a paranuclear position, while cells from poorly differentiated tumours displayed few such filaments but had more prominent cytoplasmic organelles. Desmosomes were well developed in all samples, some of which displayed numerous clearly defined intracellular desmosomes not necessarily associated with cell membrane material. Myelinoid figures were abundant and the bizarre forms which were present in some samples may be related either to abnormal metabolism or to viral activity. Glycogen, lipid droplets and intermediate filaments, possibly related to basement membrane material were observed in several samples. No single feature diagnostic for carcinoma of the oesophagus emerged from this study, but several structural similarities between oesophageal and other carcinomas were noted.

Oesophageal epithelial ultrastructure after incubation with gastrointestinal fluids and their components

Oesophageal biopsies from endoscopically normal patients were incubated in the following for up to 30 min-Ham's F10 medium:isotonic saline:0.1 N HCl:20, 2 and 0.2 mM bile acids:trypsin:pepsin:lipase; autologous gastric and duodenal juices. The biopsies were then examined by electron microscopy. No morphological change was produced by Ham's F10 or saline. HCl caused little damage. Gastric juice produced widespread severe damage, as did pepsin. Duodenal juice and the enzymes tested caused lysis and internalisation of desmosomes and peripheral cytoplasmic vacuolation. Bile acids split desmosomes and induced microvesiculation of cell membranes. Similar microvesiculation was also induced by duodenal juice. All media except hydrochloric acid eventually produced organelle damage and leaky and disrupted cells. The functional and superficial cells appeared to be able to withstand attack from these experimental media better then did prickle and basal cells. Membrane coating granules were secreted in the presence of hydrochloric acid, but not with enzymes.

Cholecystitis: a fine structural analysis

The epithelial cells from 40 gallbladders showing chronic cholecystitis and five with cholesterolosis were examined by electron microscopy. A number of features of non-specific cytological injury were noted some of which may have been related to the disease and others to anoxia. The basement membrane showed reduplication. Intraepithelial cells were identified as lymphocytes, polymorphonuclear leukocytes, macrophages and mast cells. Lipid droplets in the epithelial cells were found in 60 per cent. of the specimens.

The distribution and mobility of surface anionic groups of normal human oesophageal epithelium following interaction with cationized verritin

Oesophageal epithelial cells from biopsies from normal patients showed the presence of randomly distributed anionic groups, mostly sialic acid on the cell membrane in fixed material shown by cationized ferritin. When biopsies were pulse labelled, patching occurred in all three cell layers. Patching was energy dependent and did not occur at 4 degrees C. Pulse labelled material incubated on an unlabelled medium showed progressive loss of cationized ferritin from the cell membrane. This was mostly into the medium, although some was internalized in membrane profiles. A second pulse of cationized ferritin produced further patching suggesting regeneration of cell membrane. Superficial cells were leaky, but their organelles were not.

The ionic components of normal human oesophageal epithelium

The distribution of cations and anions in normal human oesophageal epithelium has been investigated with the pyroantimonate and silver-osmium tetroxide techniques. There is a discontinuous distribution of both ions in the intercellular space. The ions are associated with various organelles, as has already been described in the literature. Specifically, in the oesophageal epithelium, there are a few deposits of pyroantimonate and occasional silver in the membrane coating granules, but here is no apparent relationship of either ion with the tonofilaments or glycogen particles. The superficial cells are leaky and contain fewer ions than the deeper functional layer cells.