Comparison of fiberoptic endoscope and Quinton tube human gastric biopsies

Morphological examination of human gastric mucosa is being increasingly reported with the widespread use of upper gastrointestinal endoscopy. To our knowledge no studies have been reported comparing gastric mucosal tissue obtained with pinch biopsies through the endoscope with those taken by the Quinton hydraulic biopsy instrument for light and electron microscopic examination. We report such a study. Gastric biopsies were obtained from healthy volunteers. Gastric biopsies taken with the Quinton hydraulic tube have a number of distinct advantages over those taken with the standard pinch biopsy forceps. These relate primarily to the size, shape and depth of the specimens obtained. Quinton samples are large (2-3 mm in diameter), flat, discshaped specimens which are relatively free of contaminating debris on the mucosal surface. Because of their disc shape, Quinton biopsies are easily orientated for light microscopy. 55 percent of all Quinton biopsies contained muscularis mucosae. In contrast, samples taken by the standard forceps method are small (0.5--1 mm in diameter), have a tendency to roll-up into a ball, and show considerable surface debris making scanning electron microscopy of the mucosa difficult. Consistent orientation of the surface epithelium for light microscopy is more difficult with the pinch biopsies because of the small size and irregular shape of the samples. Crushing and tearing artifacts at the periphery of biopsy specimens are common. Light microscopic sections of forceps' biopsies provide a mean +/- SE of only 227 +/- 17 consecutive surface cells for examination compared to 730 +/- 24 (p less than 0.001) for Quinton biopsies. Only 7% of all pinch biopsies included muscularis mucosae.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphological changes in oral mucosae and their connective tissue cores regarding oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic disease of the oral cavity characterized by an inflammatory reaction followed by severe fibro-elastic changes. The aim of the present study was to investigate the three-dimensional morphological changes in the connective tissue cores (CTCs) of the oral mucosa in OSF. The sample consisted of buccal mucosal biopsies from ten human subjects ranging in age from 40-45 years; five of them were clinically diagnosed as having moderate to severe OSF, and the remaining five served as unaffected controls. Half of each biopsy was formalin-fixed and paraffin-embedded for light microscopy, while the other half was fixed in a Karnovsky's solution, treated with HCl to exfoliate the epithelium, and processed for examination under a scanning electron microscope (SEM). Oral submucous fibrosis biopsies exhibited heavily packed aldehyde fuchsin-positive fibers (i.e. elastic fibers) in the submucosa under the light microscope. Broad bundles of collagen fibers were seen in a concentrated manner in the deeper layers. Scanning electron microscopy of the buccal mucosa in OSF showed the finger-shaped CTCs to be attenuated beneath the epithelium at the initial stages of the disease. Patchy degenerative areas lacking the CTCs were observed in advanced cases. These degenerative areas increased gradually with the progression of the disease. Highly fibrosed cases showed severe degeneration of the CTCs, resulting in a smoothening of the connective tissue surface in the buccal mucosa.     

Morphologic evaluation of gastric mucosal protection by colloidal bismuth subcitrate (De-Nol)

The morphologic changes in the gastric mucosa of rats receiving colloidal bismuth subscitrate (CBS) at 120 mg/kg p.o. followed by intragastric instillation of 1 ml absolute ethanol have been assessed by macroscopic examination, quantitative histology and scanning electron microscopy. Macroscopically, virtually complete protection against ethanol injury was noted in CBS-pretreated animals, while control animals showed severe necrotic haemorrhagic lesions. Although light microscopy revealed disruption of the epithelium extending into the gastric pits, CBS protected deep pit cells and necrotic lesions were almost absent. By 6 h after ethanol instillation, surface epithelium was mostly restituted in the CBS group but not in the controls. Scanning electron microscopy (SEM) confirmed these findings. It is concluded that CBS protects the gastric mucosa against ethanol injury by preventing deep mucosal necrosis and that as a consequence the recovery of mucosal integrity is promoted.     

Cell renewal and gene expression in the trachea of hamster at different ages.

The tracheal mucosa of the Syrian golden hamster has been extensively employed as a model system for respiratory tract cell renewal, injury, and carcinogenesis. However, baseline cell kinetic data are not available for normal juvenile and adolescent animals in which the mucosa and cartilage are rapidly enlarging. The objective of this research was to elucidate alterations in cell kinetics, epithelial morphology, and gene expression in the trachea of hamsters at different ages. Cell kinetics were examined by 3H-thymidine labeling indices, morphology by light and electron microscopic examination, and gene expression by slot blot analysis. Results showed that mucosal epithelium of the young and adolescent hamster undergoes cyclic necrosis and cell shedding, exposing portions of the elastic basal lamina. Epithelial shedding was associated with hyperplasia and squamous metaplasia. Additionally, the labeling indices of mucosal epithelial cells and chondroblasts also exhibited variable patterns which were associated with a cyclic pattern of expression of c-fos and c-erbB2 proto-oncogenes and epidermal growth factor receptor.     

A comparative study of the surfaces of normal oral epithelia and inflammatory hyperplasias by scanning electron microscopy

The oral epithelia may show epithelial changes induced by the inflammation of the underlying lamina propria. Light microscopically, the epithelial changes are similar to epithelial dysplasia seen in a premalignant lesion. A scanning electron microscope permits a resolution higher than that of a light microscope. Therefore, it may elucidate the changes observed light microscopically. The purpose of this study was to examine the surface changes of the epithelia of parulides (gum boils) compared with those of normal oral epithelia to see if there were any surface changes due to the underlying inflammatory processes. A total of 3 specimens (1 buccal mucosa, 1 gingiva, and 1 hard palate) taken from 3 patients, one specimen from each patient, were used as controls. A total of 2 parulides from 2 patients, 1 specimen from each patient, were used as experimentals. Each specimen was cut in two. One half was prepared for light microscopy and the other half was prepared for scanning electron microscopy. Light microscopically, it was confirmed that the buccal mucosa was nonkeratinized, the gingiva was parakeratinized, and the hard palate was orthokeratinized. The epithelium of the parulis was nonkeratinized to parakeratinized with increased intercellular spaces and distinct epithelial changes similar to epithelial dysplasia. By scanning electron microscopy, the nonkeratinized mucosa (buccal mucosa) showed that most of the ridges ran parallel to each other and the parakeratinized mucosa (gingiva) and the orthokeratinized mucosa (hard palate) exhibited ridges surrounding uniform pits. The surface of the parulis of the first patient showed relatively smooth areas with residual pits, reminiscent of that of keratinized mucosa, and the surface of the parulis of the second patient showed relatively smooth areas with residual parallel ridges, reminiscent of that of nonkeratinized mucosa. Light microscopically, the oral epithelia overlying the intensely inflamed lamina propria showed distinct epithelial changes similar to epithelial dysplasia seen in a precancerous lesion but appeared normal except for markedly decreased numbers of microridges by scanning electron microscopy.     

Cell renewal and gene expression in the trachea of hamster at different ages

The tracheal mucosa of the Syrian golden hamster has been extensively employed as a model system for respiratory tract cell renewal, injury, and carcinogenesis. However, baseline cell kinetic data are not available for normal juvenile and adolescent animals in which the mucosa and cartilage are rapidly enlarging. The objective of this research was to elucidate alterations in cell kinetics, epithelial morphology, and gene expression in the trachea of hamsters at different ages. Cell kinetics were examined by ³H-thymidine labeling indices, morphology by light and electron microscopic examination, and gene expression by slot blot analysis. Results showed that mucosal epithelium of the young and adolescent hamster undergoes cyclic necrosis and cell shedding, exposing portions of the elastic basal lamina. Epithelial shedding was associated with hyperplasia and squamous metaplasia. Additionally, the labeling indices of mucosal epithelial cells and chondroblasts also exhibited variable patterns which were associated with a cyclic pattern of expression of c-fos and c-erB2 proto-oncogenes and epidermal growth factor receptor. © 1992 Wiley-Liss, Inc.     

Morphological Evidence of Neutrophil-Tumor Cell Phagocytosis (Cannibalism) in Human Gastric Adenocarcinomas

The phenomenon of neutrophil-tumor cell emperipolesis or phagocytosis has been documented by light microscopy in various human carcinomas, but little is known about the cellular pathological processes and the morphological changes involved. In an attempt to clarify the nature of this phenomenon, the authors' ultrastructural studies on the relationships among neutrophils and tumor cells in human gastric carcinomas are reviewed and analyzed. At the electron microscopy level, apoptotic neutrophils were found within vacuoles of adenocarcinoma cells in 2 cases. They showed either early apoptotic morphology with perinuclear chromatin aggregation but cytoplasm integrity or late apoptotic morphology with uniform, collapsed nucleus and tightly packed cytoplasmic granules. A light microscopy review of 200 cases of resected gastric carcinomas identified 22 cases (11%) that were characterized by neutrophil-tumor cell phagocytosis (cannibalism). TUNEL staining confirmed the presence of apoptotic neutrophils within the cytoplasm of the tumor cells. This study provides light and electron microscopic evidence of apoptotic neutrophils phagocytosed by gastric adenocarcinoma cells. The morphological features of neutrophil-tumor cell phagocytosis (cannibalism) would suggest a particular mechanism of tumor-immune escape in human gastric carcinoma.     

Histochemistry and cytochemistry of thiamine pyrophosphatase (TPP-ase 3.6.1.) in the rat gastric mucosa.

The paper deals with the histochemical and cytochemical distribution of thiamine pyrophosphatase (TPP-ase 3.6.1.) in the normal rat gastric mucosa using the method of NOVIKOFF and GOLDFISCHER (1961). In light microscopy, activity was demonstrated only in the GOLGI apparatus of the foveolar mucous cells; in the other specialized gastric mucosal cells no activity was established. At electron microscopic level, the reaction product was localized in the membranes of the cisternae of the GOLGI apparatus of foveolar mucous cells, undifferentiated neck cells, parietal cells, chief cells and in endocrine cells. The reaction product was not found in the endoplasmic reticulum of any of the above mentioned types of cells with the exception of parietal cells. The deposits of the reaction product in the cytoplasmic membrane, in the capillary endothelium and on the surface of the plasma membrane of foveolar mucous cells represents the sites of activity of alkaline phosphatase. The examination of the TPP-ase in the gastric mucosa inables us to estimate the activity of the GOLGI apparatus of gastric mucosal cells in the norm and in different pathological conditions connected with its changes.     

Bronchial mucosal structure after histamine inhalation

Previous studies have shown an increased number of inflammatory cells and an increased level of hyaluronan in the bronchoalveolar lavage (BAL) fluid, 24 h after the inhalation of histamine. In the present report, the influence of histamine inhalation on the bronchial mucosa was, therefore, investigated in 20 subjects. Scanning electron microscopy (SEM) revealed that small areas of the mucosal surface were altered or lacked cilia more frequently in the bronchial biopsies taken 24 h after the inhalation of histamine than in the control biopsies. In contrast, light and transmission electron microscopy revealed no increase in epithelial damage and no changes in the subepithelial morphology. The results indicate that inhalation of histamine does not significantly alter the structure of the bronchial mucosa, which means that bronchial biopsies can be taken for routine morphological examination within 24 h after a histamine test. When using the biopsies in research, one should consider the possible influence of the histamine test.     

Topographical variation in the mucosal surface of oesophageal biopsies

There have been comparatively few scanning electron microscopic (SEM) studies of mucosal biopsies of the human upper gastrointestinal tract. This study reviews the use of SEM in human oesophageal research and deals with the results of a SEM study of thirty two biopsies of human oesophagus, taken from eighteen patients during endoscopy for upper gastrointestinal symptoms. For each biopsy, three areas of the mucosal surface chosen at random were examined using standard magnifications. The SEM showed three mucosal patterns, which were designated typical squamous, atypical squamous and nonsquamous, each displaying common features in relation to desquamation, cell boundaries and microridges. The two squamous epithelial groups showed surface microridges. The typical group displayed clear cut cell boundaries and well developed microridges arranged in rows. The atypical squamous group showed desquamation, less well developed cell boundaries and variation in microridge patterns. Many nonsquamous specimens displayed simple columnar epithelium, similar to mucosa of gastric type. Care was taken to correlate the surface structure of the oesophagus with the endoscopic appearance. The two assessments were done independently and the material was coded throughout. The broad subdivision of the biopsies into groups using these qualitative topographical criteria gave good correspondence with the endoscopic appearance.     

Scanning electron microscopy of palatal mucosa maintained in organ culture: A method for three-dimensional visualization of cell morphology

A scanning electron microscopic (SEM) study of palatal mucosa maintained in organ culture (50% O₂-Eagle's MEM w/o serum) from 12 to 360 hours is presented. The morphological changes occurring in the explants during culture are illustrated and the findings are compared with those observed using transmission electron microscopy and light microscopy. The results confirm that cellular fine structure in epithelium and connective tissue is more easily visualized when SEM is employed following in vitro maintenance of explants as opposed to examination of fresh uncultured biopsies. The in vitro system used would appear to be applicable to studies designed to investigate the effect of various substances on cell proliferation and cell interactions.     

Light microscopic and ultrastructural evidence of in vivo phagocytosis of Helicobacter pylori by neutrophils

Helicobacter pylori is believed to cause chronic active gastritis. Infection/colonization of the gastric mucosal surface induces a mucosal inflammatory reaction in the form of lymphocytic aggregates, plasma cells and, particularly, neutrophils, which may, in turn, damage the mucosal epithelium. In vitro studies demonstrate that, in culture, the bacilli are readily phagocytosed by neutrophils, this evoking a neutrophilic oxidative burst. However, it has been claimed that neutrophils do not phagocytose H. pylori in vivo. In this study of 19 endoscopic biopsies of gastric mucosa with H. pylori-associated gastritis, Cresyl violet staining for light microscopy and electron microscopy are used to demonstrate that, in vivo, neutrophils actively phagocytose and destroy the bacilli in the epithelial intercellular space and in the mucin on the surface of the mucosa. Direct contact of neutrophils with H. pylori was observed in 17 of 17 cases by light microscopy and in 4 of 15 cases by electron microscopy. Phagocytosis by neutrophils was seen in 14 of 17 cases by light microscopy and in 3 of 1 5 cases by electron microscopy. It was most evident in the surface mucus coat where "wolf packs" of neutrophils were seen attacking the microbes. Ultrastructurally, neutrophil phagolysosomes contained both intact and partially digested bacteria, convincing evidence that the primary function of neutrophils in chronic active gastritis is to destroy H. pylori organisms. This study leaves open the question of whether, or how, neutrophils damage the gastric mucosa.     

Microwave fixation in diagnostic renal pathology

Microwave-fixed tissues were examined in 10 patients undergoing diagnostic renal biopsy. A small portion of renal tissue was fixed by microwave irradiation and subsequently processed by routine methods for light microscopic, immunofluorescent and electron microscopic studies. The remaining portion of specimen was fixed and processed by conventional methods. In light microscopic examination, the renal architecture and cell morphology were well-preserved. Pathological changes were identical to those seen with formalin-fixed tissue. The pattern, distribution and intensity of positive immunofluorescence in microwave-fixed tissue were similar to those in tissues directly snap-frozen and stained. In electron microscopy, the normal and pathological features were well-demonstrated and not different from those observed in glutaraldehyde-fixed specimens. Specific ultrastructural lesions were clearly demonstrated and, apparently, were not altered by microwave irradiation. Our preliminary data indicate that microwave fixation can be effectively applied in the processing of renal biopsies. As the fixation is rapid, this method may be valuable in circumstances when an urgent diagnosis is required.     

Light Microscopic and Ultrastructural Evidence of in Vivo Phagocytosis of Helicobacter pylori by Neutrophils

Helicobacter pylori is believed to cause chronic active gastritis. Infection/colonization of the gastric mucosal surface induces a mucosal inflammatory reaction in the form of lymphocytic aggregates, plasma cells and, particularly, neutrophils, which may, in turn, damage the mucosal epithelium. In vitro studies demonstrate that, in culture, the bacilli are readily phagocytosed by neutrophils, this evoking a neutrophilic oxidative burst. However, it has been claimed that neutrophils do not phagocytose H. pylori in vivo. In this study of 19 endoscopic biopsies of gastric mucosa with H. pylori -associated gastritis, Cresyl violet staining for light microscopy and electron microscopy areusedto demonstrate that, in vivo, neutrophils actively phagocytose and destroy the bacilli in the epithelial intercellular space and in the mucin on the surface of the mucosa. Direct contact of neutrophils with H. pylori was observed in 17 of 17 cases by light microscopy and in 4 of 15 cases by electron microscopy. Phagocytosis by neutrophils was seen in 14 of 17 cases by light microscopy and in 3 of 15 cases by electron microscopy. It was most evident in the surface mucus coat where ``wolf packs'' of neutrophils were seen attacking the microbes. Ultrastructurally, neutrophil phagolysosomes contained both intact and partially digested bacteria,convincing evidence that the primary function of neutrophils in chronic active gastritis is to destroy H. pylori organisms. This study leaves open the question of whether, or how, neutrophils damage the gastric mucosa.     

Variations in the morphology of villous epithelial cells within 8 mm of untreated duodenal ulcers

In order to investigate the bio-mechanics of duodenal ulcerogenesis and compare the 'quality' of drug mediated mucosal healing, it is necessary to define the morphological appearance of ulcerative mucosae. This report describes the morphological appearance of pre-therapy, juxta-duodenal ulcer (DU) villous epithelia. Biopsies made at endoscopy from the first part of the duodenum in four healthy volunteers and 3-8 mm from the edge of the DU in 97 patients were examined by light and electron microscopy. Irrespective of whether biopsies were made from the normal or juxta-DU mucosa, the villous epithelium was populated by one, or more, of six, morphologically identifiable cell types. Control epithelia were populated with normal goblet and absorptive cells. Based on the fine-structural characteristics of the predominant cell type, pathological specimens were divided into two groups: metaplastic (Group 1) and non-metaplastic (Group 2). Group 1 specimens were either exclusively populated with fully differentiated metaplastic gastric surface mucus secreting cells (GMC) (Group 1A), or GMC in various phases of metaplastic differentiation together with abnormal goblet cells (Group 1B). Group 2 specimens were populated with 'pathological' absorptive and normal goblet cells. It is postulated that the group variations in pre-therapy juxta-DU morphology represent various phases in the natural history of duodenal ulcerogenesis and healing.     

Topography and enterocyte morphology of the small bowel mucosal surface in equine granulomatous enteritis

The jejunal mucosa of 4 cases of equine granulomatous enteritis and 2 control horses was investigated by light microscopy and by scanning and transmission electron microscopy. Attention was focused upon changes in mucosal topography and enterocyte morphology in the inflamed mucosa. Structural changes ranged in severity from only a slight thickening and shortening of villi to the appearance of a virtually flat mucosa, upon which crypts opened directly or through shallow cavities encircled by collars of epithelial cells. Between these extremes, the mucosa showed a variety of patterns, all characterized by distinctly abnormal villus projections. These were often united by epithelial bridges and were commonly markedly short, broad and irregular. Enterocytes of mildly changed mucosae showed a normal histology and fine structure, whereas more severely changed specimens displayed a flattened surface epithelium with ultrastructural abnormalities, the most consistent being a pronounced shortening of microvilli. In particular, greatly flattened cells showed evidence of cellular injury, such as prominence of cytolysosomes and degenerative changes of the rough endoplasmic reticulum, while other cells were chiefly characterized by an abundance of non-membrane-bound ribosomes and other features signifying an immature state. Cell-membrane-tight junctions of the surface epithelium appeared to be intact. No intracellular micro-organisms were detected. It is suggested that several factors are involved in the creation of the abnormal mucosal topography in this disease, including excessive enterocyte loss, crypt cell destruction, inflammatory distension of villi and villus fusions.     

T84 cells in culture as a model for enteroaggregative Escherichia coli pathogenesis.

Enteroaggregative Escherichia coli (EAEC) is an important cause of persistent diarrhea in many developing parts of the world, yet the pathogenetic mechanisms of EAEC diarrhea are unknown. Experiments with animal models suggest that EAEC strains damage the intestinal mucosa, and a putative cytotoxin has been described. To characterize the mucosal effects of EAEC, we studied strain 042, which we have shown to cause diarrhea in adult volunteers. Strain 042 was incubated in an in vitro organ culture model with biopsy-derived normal intestinal mucosa from pediatric patients. Strain 042 adhered strongly to samples of jejunal, ileal, and colonic mucosa. In addition, scanning electron microscopic examination of in vitro-infected intestinal biopsies revealed cytotoxic effects marked by exfoliation of mucosal epithelial cells. To develop an in vitro model to study these effects, we incubated 042 with polarized monolayers of the human intestinal epithelial cell lines Caco-2 and T84. Strain 042 adhered strongly to T84 cells but not to Caco-2 cells. T84 cells infected with 042 displayed marked toxic effects, most prominently in areas where bacteria were adhering. The apical membrane of damaged cells exhibited vesiculation and shedding of microvilli. The cytoplasm of affected cells displayed subnuclear vacuolization, and in some cases, nuclei of affected cells became separated from the surrounding cytoplasm. Severely affected cells ruptured, releasing their nuclei. Vacuolated remnant cells were seen throughout the monolayer. Strain 042 was not internalized by T84 cells. We concluded that EAEC strain 042 alters intestinal cell morphology, ultimately leading to cell death. Although the factor(s) required for this effect remains to be elucidated, T84 cells may serve as a valuable model in EAEC pathogenesis studies.     

Iron medication-induced gastric mucosal injury

Severe gastrointestinal erosion, ulcer, necrosis and strictures after an acute iron overdose are well described. However, gastric mucosal injury in patients receiving therapeutic iron has received only scant recognition despite its wide use. We report a case of iron medication-induced gastric mucosal injury in a 76-year-old male who presented with iron deficiency anemia and had been taking ferrous sulfate tablet for 4 years. Esophagogastroduodenoscopy (EGD) revealed a pale, villous appearing flat lesion along the lesser curvature of gastric body. Histopathologic examination of EGD biopsies of the flat lesion showed brown crystalline materials deposited in the lamina propria of gastric mucosa, which was accompanied with fibrosis, chronic inflammation, and foreign body reaction. The crystalline materials were covered and admixed with gastric epithelium. Prussian blue iron stain confirmed that the brown crystalline materials were iron. The iron and hemosiderin accumulation was also seen in cytoplasm of epithelial cells and lumen of fundic gastric glands. The recognition and reporting by pathologists of iron-induced changes in EGD biopsies will alert clinicians to this underrecognized but easily correctable complication by alternative forms of iron therapy, such as liquid preparation.     

S.E.M. study I: Gastric and duodenal lesions induced by non-steroidal anti-inflammatory drugs (aspirin, piroxicam) in man

A scanning electron microscopy (SEM) study was performed on the gastric and duodenal mucosa of 14 patients treated with Aspirin or Piroxicam. Six patients with normal mucosal morphology were treated with either 1.5 g/day of Aspirin (3 patients) or 20 mg/day or Piroxicam (3 patients) for one month. In addition, 8 rheumatic patients were treated with a similar dose of Aspirin (4 patients) or Piroxicam (4 patients) for at least 4 months. SEM was used to evaluate the following parameters: mucosal structure, cellular exfoliation and anisocytosis, alteration of the microvilli (blebs). The mucosa showed various aspects of alterations ranging from minimal changes (microvillar alteration) to a completely subverted structure both in the stomach and in the duodenum. Mucosal changes, both on the edge of the macroscopic lesions and at a distance from these, were visible with SEM even when endoscopy was normal. Piroxicam appeared slightly less damaging than Aspirin, and no difference was observed between short-term and long-term treated patients, either with Aspirin or with Piroxicam.     

Ultrastructural Descriptions of Heterotypic Aggregation between Eosinophils and Tumor Cells in Human Gastric Carcinomas

A histological variant of gastric adenocarcinoma, characterized by an intense tumor-associated tissue eosinophilia (TATE), has been occasionally reported in the literature. The purpose of this ultrastructural study was to determine the interactions between frequently occurring eosinophils and tumor cells in gastric carcinoma characterized by TATE. Fresh tumor tissue of 92 gastric carcinomas was processed for both light and electron microscopic examination. Intense TATE was found in 7 out of 92 (7.6%) gastric carcinomas (6 of intestinal-type and 1 of diffuse-type). Electron microscopy, selectively performed in 7 cases with intense TATE, revealed eosinophils, singly or in groups, in contact with damaged or necrotic tumor cells. Activated eosinophils showing piecemeal degranulation were also found in intimate contact with viable tumor cells, characterized by plasma membrane caveolar invaginations. The authors regard this close morphological relationship as in vivo evidence for possible cross-talk between eosinophil and viable tumor cell, a conclusion that has already been drawn from experimental studies, but until now inadequately supported by ultrastructural observations in a human tumor.