Mast cells in Helicobacter pylori associated antral gastritis

Mast cells are known to be effector cells in various inflammatory reactions, but their role in gastritis is unclear. The present study was undertaken to investigate the extent of mast cell involvement in antral gastritis with and without Helicobacter pylori (H. pylori) infection and thus evaluate the possible role of mast cells in the pathogenesis of H. pylori-associated gastritis. Antral mucosal biopsies were taken from 212 subjects with symptoms suggestive of acid peptic disease. Sections were assessed for inflammation. Modified Giemsa stain was used to detect H. pylori infection and 1% toluidine blue to count mast cells. Mast cell counts were significantly higher in the antral mucosa even in H. pylori-negative gastritis (68.4 +/- 6.7/mm2), as compared to normal non-inflamed mucosa (45.7 +/- 5.8/mm2) (P < 0.05). However, with H. pylori infection, the mucosal mast cell count were markedly increased (123.8 +/- 4.7/mm2) as compared to normal mucosa (P < 0.01). and H. pylori-negative gastritis (P < 0.01) this increase was noticed uniformly in patients with H. pylori-positivity, irrespective of the presence or absence of a peptic ulcer. After cure of H. pylori infection, the mast cell density decreased significantly (44.9 +/- 4.6/mm2) to reach levels that were similar to those in normal mucosa. There was a positive correlation between the antral mucosal mast cell density and polymorphonuclear and mononuclear cell infiltration (rs = 0.61). H. pylori infection, and 0.73 respy. It was concluded that could be responsible for increasing the mast cell density in the gastric antrum. Probably by inducing castain mucosal cytokine.     

Lymphomatoid granulomatosis. Light microscopic, electron microscopic and immunohistochemical study

A case of lymphomatoid granulomatosis (LYG) involving the lungs, skin, stomach, and possibly the left kidney in a 60-year-old man is presented. The infiltrates in the lungs, stomach, and skin showed a polymorphic appearance, and consisted predominantly of lymphocytes of mature and blastic form and of a few neutrophils, plasma cells, and histiocytes. Most lymphoid cells showed irregularly shaped nuclei and clustered dense bodies, characteristics indicative of T lymphocytes. An immunohistochemical study confirmed the T cell origin of the lymphocytes; i.e. they were positive for Leu-1, Leu-3a and Ia-like antigens but negative for Leu-2a antigen and the antibodies against light chains. The homogeneity of the major population of infiltrates in LYG indicates that at least some forms of LYG may be neoplastic or pre-neoplastic lymphocytic disorders which may ultimately progress to malignant lymphoma.     

Prevalence of lymphoid follicles and aggregates in Helicobacter pylori gastritis in antral and body mucosa.

AIMS--To evaluate the prevalence of lymphoid follicles and aggregates in the antral and body mucosa in Helicobacter pylori gastritis and to assess if there were correlations with ulcers in the duodenum, pylorus, or stomach, and with chronic antral erosions. METHODS--Patients (n = 2692) with histologically confirmed H pylori antral gastritis were investigated. These comprised five groups: those with duodenal ulcers; those with pyloric ulcers; those with gastric ulcers; those with chronic erosions; and those with no associated lesions. In 1446 cases at least two additional biopsy specimens from the oxyntic mucosa were available. RESULTS--Lymphoid follicles and aggregates were found in 53.8% of cases in the antral mucosa compared with 14.8% in the oxyntic mucosa (p < 0.001). The various diseases showed significant differences in terms of the prevalence of follicles and aggregates: The highest numbers in the antral mucosa as well as the lowest in the oxyntic mucosa were found in patients with duodenal ulcers (60.5% and 9.2%, respectively). The highest numbers of follicles and aggregates in the oxyntic mucosa occurred in patients with gastric ulcers. CONCLUSIONS--The detection of lymphoid follicles and aggregates in oxyntic mucosa and the higher prevalence in antral mucosa fits well with the distribution of primary gastric lymphomas. This adds further weight to the notion that the development of follicles and aggregates, triggered by H pylori, might be an early precursor to gastric lymphoma. The differences between the groups investigated might be due to different strains of H pylori or differences in the respective sizes of antral and oxyntic mucosa.     

The surface lining cells of cardiac myxoma. Light, electron microscopic and immunohistochemical observation

Morphological, enzymatic and electron microscopic studies have been performed on the surface covering cells of cardiac myxoma (CM) in 4 clinical cases. The superficial layer of CM is composed of mono- or poly-layers of polygonal cells and the superficial cells are connected with the tumor cells within CM. Electron microscopic picture showed many microvilli on the surface of the superficial cells, and the neighboring cells extend extrusions one to another connecting with desmosomes. Formation of incomplete basal membrane was observed in the underlying cells. These cells were morphologically similar to those of the tumor cells in CM. Polygonal superficial cells were shown by scanning electron microscope, and there was no consistent arrangement, which was different from the vascular endothelial cells. Factor VIII-related antigen was proved in the tumor cells having vascular like space in CM, suggesting differentiation of the tumor cells to the vascular endothelial cells. Factor VIII-related antigen was negative in the superficial covering cells. It may be said that the superficial covering cells of CM are premature tumor cells having no character as endothelial cells.     

Immunostaining of antral gastrin cells is quantitatively increased in Helicobacter pylori gastritis

The amount of gastrin-like immunostaining in gastrin (G) cells of the antral mucosa was quantified using a computer-assisted method of measuring immunoreaction product. Biopsies from 25 patients without Heliobacter-like organisms and 60 patients with varying degrees of infection were immunostained for gastrin. Twenty-five G cells from each patient were measured both subjectively and by image analysis. Gastrin-like immunoreactivity was found to be significantly increased in the presence of Heliobacter-like organisms.     

Electron microscopic immunohistochemical investigation of chromogranin A in endocrine cells in human oxyntic gastric mucosa

Human oxyntic gastric mucosa harbours 6 types of endocrine cells: enterochromaffin-like (ECL) cells, enterochromaffin (EC) cells, somatostatin (D) cells, and cells with an unknown secretory product (P cells, D1 cells and X (A-like) cells). In the present study, intracellular localization and granular content of chromogranin A (CGA) in these cells have been investigated by electron microscopic immunohistochemistry. The content of CGA in granules of the various types of endocrine cells was evaluated and compared with the content of serotonin and somatostatin in EC cells and D cells, respectively. ECL cells, EC cells, P cells, D1 cells and X cells contained CGA in their granules, whereas D cells did not. CGA granular content in ECL cells, P cells, D1 cells and X cells was 3.39 +/- 0.17, 3.41 +/- 0.21, 3.58 +/- 0.18, and 3.55 +/- 0.09, respectively. In ECL cells, CGA was also found in a nongranular form. The CGA content in EC cells (2.95 +/- 0.21) was not significantly different from the serotonin content (2.82 +/- 0.11; p > 0.05) which is in line with the basic significance of CGA as potential amine storage and release protein. The somatostatin content in D cells was 3.30 +/- 0.15. Our study has established high content of CGA in granules of all types of endocrine cells in human oxyntic gastric mucosa except in D cells.     

Epithelioid hemangioendothelioma of the anterior mediastinum with osteoclast-like giant cells. Light microscopic, immunohistochemical, and electron microscopic study

A case of epithelioid hemangioendothelioma of the anterior mediastinum in a 40-year-old woman is presented. It showed typical features described in such tumors, but in addition there were foci of osteoclast-like giant cells that were not previously reported in this lesion.     

Helicobacter pylori-related gastritis and gastric ulcer. A continuum of progressive epithelial degeneration.

One hundred forty-five consecutive gastric biopsy specimens showing colonization by Helicobacter pylori (HP) were studied. Biopsy specimens were obtained from patients with the following conditions: gastric ulcer (GU; 76), active chronic gastritis (ACG; 52), GU with duodenal ulcer (DU; 10), and ACG with DU (7). The mean age of the patients in the ACG group was 8.6 years less than the patients in the GU group. Helicobacter pylori colonization and HP-induced epithelial degeneration (ED) were quantified by a grading system (grades 0 to 6) comprising both focal and global scores for bacterial density (HP grade) and severity of ED (ED grade). The ED grade was directly proportional to the HP grade in all biopsy specimens. Gastric ulcer biopsy specimens were associated with higher HP grades: HP grade more than 5 in 25 cases (32.9%) and ED grade more than 5 in 18 cases (23.6%) of GU compared with similar respective scores in 9 cases (17.9%) and 2 cases (3.8%) of ACG. The difference was due primarily to a higher global score of bacterial density and higher focal score of ED in the GU biopsy specimens. These results support the hypothesis that HP-positive ACG and HP-positive GU are lesions within a single disease spectrum. Heavy HP colonization and severe HP-induced epithelial damage are predisposing factors in ulcerogenesis. Because HP-positive ACG is probably a preulcerative state, eradication of the bacteria in HP-positive ACG might prevent subsequent GU.     

Two cases of acquired toxoplasmic lymphadenitis. Light and electron microscopic and immunohistochemical studies

We report two cases of acquired toxoplasmic lymphadenitis, one with toxoplasmic cysts and the organisms of Toxoplasma gondii and the other with the organisms only. These cysts and organisms were observed in paraffin-embedded sections, touch smears and ultrathin sections for electron microscopy. Touch smears were especially valuable for the quick and accurate diagnosis of toxoplasmic lymphadenitis. We also studied immature sinus histiocytosis (ISH) in these cases. The predominant cells of ISH were confirmed to be B lymphocytes immunohistochemically, the majority being positive for polyclonal surface IgM. ISH was observed in the perifollicular and paracortical areas surrounding post-capillary venules (PCV), whereas the sinuses were only partially involved.     

Parvalbumin-like immunostaining in the cat inferior colliculus. Light and electron microscopic investigation

The presence of the calcium-binding protein parvalbumin (PV) was studied in neuronal elements of the cat's inferior colliculus (IC) by means of light and electron microscopic immunocytochemistry. Immunostaining of PV was detected in all three main parts of the IC. Several subtypes of large neurons that differed in size and shape were immunostained, comprising approx. 15% of the total number of PV-containing neurons. Approx. half of the labeled neurons were medium sized. Two types of small neurons were found to be PV synthesizing, and comprised approx. 35% of the total PV-containing population. Ultrastructurally, many dendrites were heavily immunolabeled, and the reaction product was present in dendritic spines as well. Several types of synaptic boutons contained reaction product, and terminated on both labeled and unlabeled postsynaptic targets forming asymmetric and symmetric synapses. Approx. 70% of all PV-immunolabeled terminals contained round synaptic vesicles and formed asymmetric synapses. The majority of these boutons were of the "large round" type and corresponded to the terminals of cochlear nuclei. A lower number were of the "small round" type, and were probably corticotectal terminals. The remaining 30% of PV-containing terminals contained pleomorphic or elongated vesicles and formed symmetric synapses. These terminals corresponded with "P" and "F1" bouton types. Part of these boutons appeared to arise from nuclei of the lateral lemniscus and the superior olive, and a certain percentage likely represented endings of inhibitory interneurons.     

Light and electron microscopic investigation of parathyroid carcinoma during differentiation

Summary A case of parathyroid carcinoma in a 74-year-old female patient was studied by light and electron microscopy.The malignancy of the parathyroid tumour was confirmed by local recurrence and infiltration of adjacent structures. The tumour was composed of uniform chief cells without mitoses. Ultrastructurally, the cells were characterized by tortuous plasma membranes, numerous secretion granules, an extensive rough endoplasmic reticulum and lack of lipid vacuoles, all indicating hyperactivity, but not malignancy.At death, the autopsy revealed local recurrence of tumour tissue, but no distant metastases. Both light and electron microscopy showed that considerable dedifferentiation of the tumour tissue had occurred. The tumour cells were now characterized by a marked nuclear pleomorphism and a coarse clumping of the chromatin. The presence of secretion granules alone suggested a parathyroid origin.Thus, at death there was unequivocal histological evidence of a carcinoma, whereas no such diagnosis could be made from the early biopsy. The clinical course alone indicated the malignant nature of the lesion.     

Elastin in adenomatoid tumor. Light microscopic and electron microscopic study.

Elastin distribution was examined in adenomatoid tumors of the human genital tract. Two distinct patterns were identified: strongly positive or completely negative for elastin in the stroma, according to the case. Even in cases appearing to have very similar histologic features, the stroma was rich in elastin in some cases and was almost devoid of elastin in others. Electron microscopic examination with tannic acid staining revealed that the elastin in the stroma was composed mainly of amorphous material surrounded by a small amount of microfibrils and abundant collagen fibers. Fibroblasts were sparsely distributed in the stroma. Tumor cells displayed mesothelial cell-like features, such as abundant microvilli on the surface, numerous cytoplasmic organelles, several well-developed basal lamina. In some areas, elastin seemed to be formed by mesothelial cells. In some adenomatoid tumor cases, elastogenesis would be enhanced by activated mesothelial tumor cells as well as stromal fibroblasts.     

De novo expression of aromatase in gastric carcinoma. Light and electron microscopic immunohistochemical and immunoblot study.

We have performed immunohistochemical and immunochemical studies of steroidogenic enzymes involved in estrogen biosynthesis in 30 cases of gastric carcinoma in order to investigate possible in situ production of estradiol (E 2) in carcinoma cells. Positive incidence of immunoreactivity for E 2, testosterone (T), cholesterol side-chain cleavage enzyme (P-450 scc) and aromatase (P-450 arom) were 17/30 (56.7%), 11/30 (36.7%), 3/30 (10.0%) and 23/30 (76.7%), respectively on light microscopy. Estrogen receptor (ER) immunoreactivity was not observed in any of the 30 cases examined. Normal gastric mucosa was negative for P-450 arom and P-450 scc. Examination of serial sections revealed that immunoreactivity of E 2 and P-450 arom were located in the same cells of carcinomatous glands. Immunoelectron microscopy demonstrated that E 2 and P-450 arom were located along the membrane and cisternae of smooth endoplasmic reticulum (sER). Western blot analysis showed one major band of 55 kDa of P-450 arom in the gastric carcinoma tissues examined. Retrospective analysis of immunohistochemistry of E 2 in 108 cases of gastric carcinoma revealed that E 2 positive carcinoma cases were likely to demonstrate better survival rate than negative cases. These results above strongly suggest that E 2 is produced by de novo expressed aromatase in gastric carcinoma cells and is possibly involved in the biology of gastric carcinoma cells.     

Light and scanning electron microscopic and immunohistochemical studies on permeability of hypertensive rat mesenteric arteries

Experimental hypertensive rats were intravenously injected with carbon and iron as tracers, and their mesenteric arteries exhibiting hypertensive arterial lesions were observed by light and scanning electron microscopy and immunohistochemistry. Early arterial lesions showing intense medial damages, deposition of fibrinoid substance consisting of fibrin in the intima and/or media, and granulation tissue in the adventitia were characterized by marked insudation of intravenously injected tracers. Scanning electron microscopy demonstrated numerous leukocytes and platelets adhering to endothelial surface, opened endothelial cell junctions, and desquamation of these cells. Immunohistochemistry revealed laminin and low stainability of fibronectin in the subendothelium. Advanced lesions showed deposition of a large amount of fibrinoid substance and no insudation of tracers in the intima, but scanning electron microscopy manifested opening of endothelial cell junctions, desquamation of endothelial cells, and adherence of leukocytes and platelets. Immunohistochemistry revealed fibronectin in the intima and laminin just beneath the endothelium. In the healed lesions disclosing fibrocellular intimal thickening, there was no insudation of tracers. Scanning electron microscopy showed opened endothelial cell junctions, endothelial cell defects, and adherence of leukocytes and platelets. There were fibronectin in the intima and laminin beneath the endothelium. It was suggested that the opening of endothelial cells junctions and desquamation of endothelial cells would be necessary for the arterial increased permeability in hypertensive rats, and that fibrin-fibronectin complex, fibronectin-acid mucopolysaccharide complex, and basement membrane would together inhibit the increased permeability in the mesenteric arteries of hypertensive rats in spite of endothelial cell injuries and their defects.     

Increased frequency of antral CD4 T and CD19 B cells in patients with Helicobacter pylori-related peptic ulcer disease

Only a fraction of Helicobacter pylori (HP)-infected individuals develop clinical disease. Recent research indicates that immunological mechanisms may be important for understanding the pathophysiology of HP infection. Differences in the individual cellular immune response may reflect the clinical diversity. The aim of the present study was to investigate the cellular immune response against HP in three clinically well-defined patient groups: HP-positive peptic ulcer, HP-positive and HP-negative gastritis. Biopsies from gastric mucosa were processed for analysis by flow cytometry and histology. The number of T lymphocytes (CD3+) was significantly higher in HP-positive peptic ulcer (13.8%) than in HP-positive nonulcer gastritis (6.3%). A nonsignificant increase for B lymphocytes (CD19+) was noted as well. Furthermore, a significant difference was seen in mucosal CD4/CD8 ratio between HP ulcer (2.4) and nonulcer HP gastritis (1.0) patients. Thus, B cells (CD19+) and T-helper cells (CD4+) were dominant in gastric mucosa from peptic ulcer patients, and cytotoxic T cells (CD8+) were relatively dominant in gastric mucosa from nonulcer patients. In conclusion, distinct differences in the T-cell subset distribution of mucosal lymphocytes were detected in patients with HP infection, strongly correlated with the presence or absence of peptic ulcer.     

Association of Campylobacter pylori on the gastric mucosa with antral gastritis in children

We investigated the presence of Campylobacter pylori colonization of the gastric mucosa and of histologic evidence of gastritis in a prospective study of 71 consecutive children undergoing upper gastrointestinal tract endoscopy and gastric biopsies because of gastrointestinal symptoms. Two tissue samples from the gastric antrum were obtained from 67 of the 71 children (mean age [+/- SD], 11.4 +/- 3.8 years). One sample was evaluated for evidence of gastritis and stained with silver to detect organisms morphologically resembling campylobacter. The second sample was cultured for C. pylori, and a portion was used to perform a urease-screening test for the presence of C. pylori. Antral gastritis was diagnosed histologically in 18 of 67 patients. C. pylori was identified by both culture and silver staining on the antral mucosa in 7 of 10 patients with unexplained gastritis (primary gastritis) but in none of 8 patients with gastritis associated with an identifiable underlying cause (secondary gastritis). C. pylori was not identified in any of the 49 cases with normal histologic features. The urease-screening test was positive in only three of six patients with a positive culture for C. pylori. Duodenal ulcers were diagnosed by endoscopy in five patients. Each of the five had C. pylori on the antral mucosa, but organisms were not identified on the duodenal mucosa. We conclude that the presence of C. pylori on the antral mucosa is specifically associated with primary antral gastritis and may also be associated with primary duodenal ulceration.     

Calcitonin-producing insulinoma. An immunohistochemical and electron microscopic study

A pancreatic endocrine tumor measuring 1.5 X 1.0 X 1.0 cm in a 67-year-old man with recurrent hypoglycemic attacks was examined by immunohistochemistry and electron microscopy. The tumor cells were relatively uniform, and almost all of them were immunoreactive to insulin. A few calcitonin-positive cells could be identified scattering in tumor cell strands, and the content of calcitonin in the tumor was 85 ng/g wet tissue. Coexistence of insulin and calcitonin in tumor cells was demonstrated by using adjacent semithin sections of the Epon-embedded material. Electron microscopically, the tumor consisted of a single type of cells with secretory granules identical to B-cell granules in the normal counterpart.