Distribution of the carbonic anhydrase isoenzymes I, II, and VI in the human alimentary tract.

The distribution of carbonic anhydrase isoenzymes I, II, and VI was studied in the human alimentary tract using specific antibodies to human isoenzymes in conjunction with the immunoperoxidase technique to elucidate the physiological role and possible functional interplay of carbonic anhydrases (CAs) in alimentary canal functions. From the isoenzymes studied, CA II was found to be the most widely distributed in the various epithelia throughout the alimentary canal. In addition to the acinar cells of the parotid and submandibular glands and the duodenal Brunner's glands, it was present in the mucosal epithelium of the oesophagus, stomach, duodenum, and colon. The epithelial cells of the hepatic bile ducts, gall bladder, and pancreatic ducts also contained CA II in abundance. In contrast, CA VI was present only in the serous acinar and ductal cells of the parotid and submandibular glands, and CA I in the mucosal epithelium of the colon and the A cells of the pancreatic Langerhans's islets. These results suggest that CA II as a widely distributed isoenzyme in the epithelia of the alimentary canal and CA VI as secreted into saliva, may form a mutually complementary system protecting oesophageal, gastric, and intestinal mucosa from acidity.     

Pancreatic secretory trypsin inhibitor in human Brunner's glands

Brunner's glands (duodenal glands) in humans are located mainly in the two proximal thirds of the duodenum. They are known to produce and secrete mucin. In recent years, human Brunner's glands have also been shown to express immunoreactivity toward epidermal growth factor-urogastrone (EGF-uro) and lysozyme. These proteins are considered to have a protective function within the gastrointestinal canal. Human pancreatic secretory trypsin inhibitor (PSTI) was recently identified in Brunner's glands. This present study was done by an immunohistochemical method, using monospecific polyclonal antibodies against human PSTI and human lysozyme, respectively. McManus/Alcian blue mucin staining was used to clarify the distribution of mucin. We found immunoreactive PSTI (irPSTI) in seven out of ten specimens. Lysozyme and mucin were present in all ten. While virtually all cells were stained for lysozyme and mucin, irPSTI was restricted to separate lobules and to cells in the ducts.     

Cystic changes in gastric glands after gastric surgery and in the intact stomach

Cystic changes of gastric mucosal glands have been described mainly after gastric operations, and like intestinal metaplasia and dysplasia, they may represent a premalignant condition. Their association with gastritis raises the possibility of their being secondary to the inflammatory process. Enterogastric reflux of duodenal contents, local chronic ischemia, and inflammatory reaction as a result of gastric surgery and suture at gastroenterostomy have been considered responsible for this lesion. In 18 of 157 consecutive patients (11.5%) who underwent endoscopic gastric biopsy within a year we found cystic changes of gastric mucosal glands. Cystic changes were present in 43% of 30 patients after gastric operation for duodenal ulcer disease, within an average of 8.4 years in contrast to only 4% of patients with an intact stomach. This change is statistically significant (Z = 1.97, (p less than 0.05) and suggests that there is a cause-and-effect link between the operation and the development of cystic lesions. In three patients we traced the original operative specimen, and in none did we find cystic changes. All the cases were associated with chronic gastritis; mild dysplasia was found in four (22%). The cystic glands were shown (by alcian blue-periodic acid-schiff staining) to secrete neutral mucin like normal gastric glands, and unlike dysplastic glands or intestinal metaplasia where acid mucin is characteristic. Thus, our findings suggest an inflammatory cause for the cystic glandular change (reactive, hyperplastic change of glands), and suggest that it is probably not a preneoplastic state.     

The identification of urogastrone in serum, saliva, and gastric juice.

Urogastrone, a peptide isolated from human urine, is known to cause inhibition of gastric acid secretion and proliferation of fibroblasts in culture; furthermore immunofluorescent localization techniques show it to be present in submandibular and Brunner's glands. Serum, saliva, and gastric juice samples have now been fractionated upon Sephadex G-200 and G-50 and the immunoreactive urogastrone located using a specific radioimmunoassay. Biologic activity was shown by mitogenic studies with 3T6 fibroblasts. In serum, the major immunoreactive component was ca. 1-2 X 10(5) daltons, but trypsin treatment then gave a smaller biologically active species in the same position as pure urogastrone on Sephadex G-50. Both saliva and gastric juice showed major components at the position defined by urogastrone, and these also stimulated the uptake of [H]thymidine into the fibroblasts. It is concluded that a urogastrone-like molecule can be released enzymically from a high molecular weight serum precursor and that the small biologically active peptide is also a normal component of saliva and gastric juice.     

Role of epidermal growth factor in healing of chronic gastroduodenal ulcers in rats

The healing of acetic acid-induced gastric and duodenal ulcers was examined together with biochemical indices of growth in gastric and duodenal mucosa in rats with intact or removed salivary glands after treatment with epidermal growth factor (EGF) or somatostatin, or both. After the extirpation of salivary glands, the healing rate of gastric and duodenal ulcerations was delayed and gastric content of immunoreactive EGF was reduced. This was accompanied by a significant decrease in the contents of deoxyribonucleic acid and ribonucleic acid in the gastric and duodenal mucosa. Repeated administration of EGF either subcutaneously or orally accelerated the healing of gastroduodenal ulcers in rats with intact salivary glands and completely reversed the delay in ulcer healing in sialoadenectomized animals. These effects were also accompanied by a significant increase in the growth parameters of gastric and duodenal mucosa. Administration of somatostatin, which prevented the growth-promoting action of subcutaneous EGF, resulted in a significant decrease in the EGF-stimulated healing of gastric and duodenal ulcerations in both intact and sialoadenectomized rats. Our findings suggest that cell proliferation is an important factor in healing of gastric and duodenal ulcerations and that EGF plays an important role in ulcer healing due to its mitogenic action.     

17Beta-estradiol modulates gastroduodenal preneoplastic alterations in rats exposed to the carcinogen N-methyl-N'-nitro-nitrosoguanidine.

Gastric cancers are a significant cause of morbidity worldwide. Epidemiological studies and animal models show that males have higher incidences of gastric cancers compared with females, suggesting that sex hormones may modulate gastric cancer risk. An animal model of the initiation phase of gastric cancer was used to determine the effects of systemic estrogen administration on morphological progression of preneoplastic lesions and to define cell populations at which estrogens may act. Preneoplastic progression in antral and duodenal mucosa was examined in male rats that received the chemical carcinogen, N-methyl-N'-nitro-nitrosoguanidine (MNNG), during treatment with implants containing 17beta-estradiol or oil vehicle. Histopathological changes in antral and duodenal gland morphology, numbers of proliferating cells and apoptotic bodies, and antral gastrin cell numbers and protein storage levels were determined 4 weeks later. With MNNG treatment, duodenal villous heights were significantly decreased, and epithelial cells displayed histological features of hyperplasia and dysplasia. Antral glands showed epithelial hyperplasia and dysplasia, increased mucosal height, and decreased mucin levels. Antral gastrin storage protein levels were decreased by MNNG. Systemic treatment with 17beta-estradiol significantly reversed MNNG-induced alterations in duodenal gland heights while increasing mucin and gastrin levels in antral glands. Cell proliferation and apoptosis rates were not significantly different between groups. The present results indicate that systemic 17beta-estradiol treatment influences antral and duodenal gland differentiation during the initiation phase of chemical gastroduodenal carcinogenesis in male rats. These results explain, in part, a potential pathway through which protective effects of estrogens on chemical carcinogenesis are mediated in the upper gastrointestinal tract.     

Immunohistochemical localisation of vitamin B12 R-binder in the human digestive tract.

The distribution of vitamin B12 R-binder in the human digestive tract was studied using an indirect immunoperoxidase technique. Positive staining for R-binder was found in the mucous cells and ductal epithelial cells of the salivary glands and the oesophageal glands. In normal gastric mucosa, no positive staining for R-binder was found, but in the area with intestinal metaplasia, the columnar epithelial cells and goblet cells showed positive staining. Epithelial cells of the gallbladder, intrahepatic bile ducts and pancreatic ducts were also positive for R-binder. In the small intestine and colon, R-binder was found in the columnar epithelial cells and goblet cells. The measurement of unsaturated vitamin B12 binding capacity and cobalamin content in the extracts from intestinal mucosa also indicated the presence of R-binder in the intestinal mucosa.     

Immunohistochemical detection of beta-amyloid and beta-amyloid precursor protein in the canine brain and non-neuronal epithelial tissues.

We examined the immunohistochemical localization of beta-amyloid (Abeta) and beta-amyloid precursor protein (AFPP) in the neuronal and non-neuronal tissues of 14 aged (over 10 years old) and 4 young (0-4 years old) dogs. Abeta was detected only in the senile plaque in the cerebrum of aged dogs. AbetaPP was expressed in the neuronal cell body, neuronal fiber, senile plaque and perimalacic tissue independent of age. In addition, epithelial cells in the bronchus, bronchial glands, gastric and intestinal mucosa, intrahepatic bile ducts, and pancreatic ducts and exocrine glands were immunopositive for AbetaPP. Thus, it is suggested that AbetaPP may be expressed in the non-neuronal epithelial tissues independent of age and of the presence of senile plaques, and the expression may depend on individual differences or physiological conditions.     

Stainable Iron in Gastric and Duodenal Mucosa of Primary Hemochromatosis Patients and Alcoholics

The presence of iron in gastric and duodenal mucosa was investigated with Perl's stain in endoscopic biopsies from 13 patients with overt primary hemochromatosis, 10 chronic heavy alcohol abusers, and 10 patients with nonulcer dyspepsia. In the primary hemochromatosis patients marked iron deposition was found in cells at the base of glands in the gastric body and antrum in nine cases, and in crypt cells and Brunner gland cells of the duodenum in six. Iron was detected in the lamina propria of the stomach in five and duodenum in four cases. A similar distribution of iron overload, usually of lesser degree, was also observed in five alcoholics. Serum ferritin levels and the degree of gastric and/or duodenal iron deposits did not correlate in either hemochromatosis patients or alcoholics. No gastric or duodenal siderosis was observed in nonulcer dyspepsia cases. The absence of gastric and duodenal stainable iron in some hemochromatosis patients and its presence in some alcoholics suggests that the diagnostic value of upper gastrointestinal biopsy in primary hemochromatosis is limited.     

Induction of gastric epithelial apoptosis by Helicobacter pylori.

BACKGROUND--Helicobacter pylori may promote gastric carcinogenesis through increasing gastric epithelial cell proliferation. How H pylori does so is unknown. Programmed, non-necrotic, cell death (apoptosis) occurs throughout the gut and is linked to proliferation. It was hypothesised that H pylori may induce hyper-proliferation through increasing apoptosis. AIM--To measure the effect of H pylori infection on gastric epithelial apoptosis in situ. PATIENTS--Patients with duodenal ulcers treated to eradicate H pylori and patients with H pylori negative non-ulcer dyspepsia. METHODS--Retrospective quantification of apoptotic epithelial cells in situ from formalin fixed biopsy specimens, counted after staining by terminal uridine deoxynucleotidyl nick end-labelling. RESULTS--In the uninfected stomach, apoptotic cells were rare and situated in the most superficial portion of gastric glands (mean 2.9% of epithelial cells). In H pylori infection, they were more numerous and were located throughout the depth of gastric glands, comprising 16.8% of epithelial cells, falling to 3.1% after H pylori eradication, p = 0.017. Apoptotic cell number did not correlate with the degree of histological gastritis. CONCLUSIONS--These results suggest that H pylori induces epithelial apoptosis in vivo. Increased apoptosis may be the stimulus for a compensatory hyperproliferative and potentially preneoplastic response in chronic H pylori infection.     

VIP-, substance P- and met-enkephalin-immunoreactive innervation of the human gastroduodenal mucosa and Brunner's glands.

VIP-, substance P- and met-enkephalin-containing innervation of the human gastroduodenal mucosa and Brunner's glands was studied by immunocytochemistry on whole mount tissue preparations. A dense VIP-containing nerve supply was found around fundic and pyloric glands, while the few and scattered substance P-immunoreactive fibres tended to run across the full thickness of the gastric mucosa. In the duodenum, both VIP and substance P were present in a striking nerve network in the villi as well as in the muscularis mucosae and around blood vessels. Both peptides were also immunostained in nerve bundles and neuronal perikarya between the lobules of Brunner's glands, while only very few fibres reached the proximity of acinar cells. Met-enkephalin-immunoreactivity was detected in a small number of nerve fibres, virtually confined to the basal parts of the mucosa and to the duodenal submucous plexus.     

Salivary secretion in duodenal ulcer disease

Salivary response to stimulation with citric acid was higher in patients with duodenal ulcer disease than in patients with other diseases of the upper gastrointestinal tract. This increase was proportional to an increase of histamine-stimulated gastric acid secretion. In duodenal ulcer disease, the increase in parietal cell mass may therefore be associated with the growth of other exocrine organs such as the salivary glands.     

The pathogenesis of duodenal gastric metaplasia: the role of local goblet cell transformation

BACKGROUND AND AIMS: Gastric metaplasia is frequently seen in biopsies of the duodenal cap, particularly when inflamed or ulcerated. In its initial manifestation small patches of gastric foveolar cells appear near the tip of a villus. These cells contain periodic acid-Schiff (PAS) positive neutral mucins in contrast with the alcian blue (AB) positive acidic mucins within duodenal goblet cells. Previous investigations have suggested that these PAS positive cells originate either in Brunner's gland ducts or at the base of duodenal crypts and migrate in distinct streams to the upper villus. To investigate the origin of gastric metaplasia in superficial patches, we used the PAS/AB stain to distinguish between neutral and acidic mucins and in addition specific antibodies to immunolocalise foveolar cell mucin MUC5AC, the foveolar cell secretory product, gastric trefoil factor (TFF1), the mature goblet cell mucin MUC2, and MUC2 core antigen. RESULTS: Cells in focal patches of gastric metaplasia contained secretory granules of both gastric and goblet cell phenotypes. MUC5AC and TFF1 were present as expected in gastric foveolar cells but in addition, MUC2 core antigen, normally present only in the Golgi of intestinal goblet cells, was expressed in secretory granules. Goblet cells in the vicinity of metaplastic patches also expressed both gastric and intestinal antigens. MUC5AC/MUC2 containing goblet cells were most common near the villus tip but were also seen at the base of crypts. Where crypts and Brunner's gland ducts merged they were always seen on the crypt side of the junction. Goblet cells were the only cells to express gastric antigens in these areas. In advanced metaplastic lesions, dual phenotype goblet cells were less evident and fewer cells expressed intestinal mucin antigens. CONCLUSIONS: We suggest that goblet cells that express both intestinal and gastric antigens may represent local precursors of gastric metaplasia undergoing a transition to foveolar-like cells of mixed phenotype at the site of early metaplastic patches. As metaplasia becomes more widespread, a more pure gastric phenotype emerges. This progression is likely to be controlled by local inflammatory signals.     

Effects of nonsteroidal anti-inflammatory drugs and misoprostol on gastroduodenal epithelial proliferation in arthritis.

In this study, quantitation of the epithelial proliferation status of gastric glands and duodenal crypts was performed using endoscopic biopsy specimens from patients with rheumatological conditions requiring long-term anti-inflammatory and analgesic therapy, testing the hypothesis that long-term administration of nonsteroidal anti-inflammatory drugs (NSAIDs) may lead to enhanced epithelial cell proliferation in the stomach and duodenum. After a 1-week washout period from NSAID administration, specimens were taken from endoscopically normal gastric antrum and duodenum, and microdissection was used to quantitate mitoses in these sites. Endoscopy and biopsy were then repeated after 2 weeks of NSAID administration, during which patients received in addition either the prostaglandin E1 analogue misoprostol (10 patients) or a placebo (10 patients). Mitotic counts in gastric glands increased similarly and significantly in the two groups from (mean +/- SEM) 4.45 +/- 0.57 to 7.69 +/- 1.08 (P less than 0.001) in the NSAID+placebo-treated group and from 4.31 +/- 0.53 to 7.68 +/- 1.08 (P = 0.006) in the NSAID+misoprostol-treated group. Similar changes took place in the duodenal crypts, from 5.44 +/- 0.68 to 8.60 +/- 1.28 (P = 0.013) in the NSAID+placebo-treated group and from 4.68 +/- 0.56 to 6.35 +/- 0.63 (P = 0.011) in the NSAIDs+misoprostol-treated group. NSAIDs increased the proportion of glands and crypts with bifid or more complex architectural forms. In a small group of patients, misoprostol alone did not alter mitotic rate in glands or crypts over 4 weeks. Thus, NSAIDs increase the rate of proliferation in endoscopically normal gastric and duodenal epithelium of patients with arthritis. This may form one of the mechanisms underlying gastric and duodenal adaptation to NSAIDs.     

Immunohistochemical detection of β-amyloid and β-amyloid precursor protein in the canine brain and non-neuronal epithelial tissues

We examined the immunohistochemical localization of β-amyloid (Aβ) and β-amyloid precursor protein (AβPP) in the neuronal and non-neuronal tissues of 14 aged (over 10 years old) and 4 young (0–4 years old) dogs. Aβ was detected only in the senile plaque in the cerebrum of aged dogs. AβPP was expressed in the neuronal cell body, neuronal fiber, senile plaque and perimalacic tissue independent of age. In addition, epithelial cells in the bronchus, bronchial glands, gastric and intestinal mucosa, intrahepatic bile ducts, and pancreatic ducts and exocrine glands were immunopositive for AβPP. Thus, it is suggested that AβPP may be expressed in the non-neuronal epithelial tissues independent of age and of the presence of senile plaques, and the expression may depend on individual differences or physiological conditions.     

Effects of progestins and menstrual cycle on fatty acid synthetase and progesterone receptor in human mammary glands

Fatty acid synthetase (FAS) is induced by progestins in human breast cancer cell lines. To study its regulation in normal mammary glands, the FAS level was estimated by immunohistochemistry, using the biotin-streptavidin method, in ducts and lobules of normal tissues adjacent to nonproliferative benign breast lesions collected by biopsy. Rabbit polyclonal antibodies to human FAS specifically recognized the 250-kDa FAS from MCF7 cells, as shown by Western immunoblotting. An excess of purified FAS totally switched off FAS immunostaining of R5020-treated MCF7 cells, demonstrating the validity of FAS immunocytochemical detection. FAS labeling was quantified using a computer-aided image analyzer (SAMBA 2005) in 18 patients receiving progestin therapy from the 15th to the 25th day of the menstrual cycle and 26 untreated patients. In the 2 groups, FAS staining, absent of fibroblasts, was observed in the cytoplasm of epithelial cells. It was higher in lobules than in ducts and increased significantly from the follicular to the luteal phase in both structures. Progestin treatment increased FAS expression in both structures. Using monoclonal antibodies, progesterone receptor expression was measured in frozen serial sections. In patients receiving progestin treatment, the progesterone receptor level increased from the beginning of the cycle to day 14 and then decreased during the second part of the menstrual cycle, probably down-regulated by progestin, indicating a regulation similar to that in the endometrium. We conclude that FAS is induced by progestins in the ducts and lobules of human normal mammary glands as it is in human breast cancer cells. FAS may, therefore, be useful for studying the effect of progesterone in normal human mammary glands.     

Glandular elements around the intrahepatic bile ducts in man; their morphology and distribution in normal livers

The morphology and distribution of the glandular elements around the intrahepatic bile ducts, hitherto poorly described, were examined in autopsied human livers with the aid of postmortem cholangiographs. The glands could be divided into intramural and extramural. The former were small in number, scattered within the bile duct walls, and were simple tubular mucous glands. The latter were more abundant, located in the periductal connective tissue, and were branched tubuloalveolar seromucous glands. Serial section observations revealed that neither gland communicated with the hepatic parenchyma, and the extramural glands drained into the large bile duct lumina via the conduits. The mucous cells of both glands contained neutral, carboxylated and sulfated glycoproteins. The extramural glands were distributed from the hepatic to the segment ducts in almost all livers, and were also discerned around the area ducts in two-fifths of the livers. The glands seemed to decrease in number as the bile ducts became more branched.     

Analysis of human sodium iodide symporter immunoreactivity in human exocrine glands

The human sodium iodide symporter (hNIS) is an intrinsic transmembrane protein that mediates the active transport of iodide across the basolateral membrane of thyroid follicular cells. In addition to normally functioning thyroid tissue, various extrathyroidal tissues, including salivary gland, lacrimal gland, gastric mucosa, choroid plexus, and lactating mammary gland, have been demonstrated to accumulate iodide. After cloning and molecular characterization of the sodium iodide symporter, expression of hNIS messenger ribonucleic acid has been detected in a broad range of extrathyroidal tissues using Northern blot analysis and RT-PCR. In this study we used both monoclonal and polyclonal antibodies directed against different portions of hNIS protein together with a highly sensitive immunostaining technique to assess hNIS protein expression in tissue sections derived from normal human salivary and lacrimal glands, pancreas, as well as gastric and colonic mucosa. Immunohistochemical analysis of normal human salivary and lacrimal glands revealed marked hNIS immunoreactivity in ductal cells and less intense staining of acinar cells. Further, immunostaining of gastric and colonic mucosa showed marked hNIS immunoreactivity confined to chief and parietal cells in gastric mucosa and to epithelial cells lining mucosal crypts in colonic mucosa. In normal human pancreas, hNIS immunoreactivity was located in ductal cells, exocrine parenchymal cells, and Langerhans islet cells. In conclusion, our study demonstrates the expression of hNIS protein by several human exocrine glands, suggesting that iodide transport in these glands is a specific property conferred by the expression of hNIS protein, which may serve important functions by concentrating iodine in glandular secretions.     

Participation of peribiliary glands in biliary tract pathophysiologies

AIM:To investigate the roles of peribiliary glands around the bile ducts in the pathophysiology of the biliary tract.METHODS:The expression of fetal pancreatic markers,pancreatic duodenal homeobox factor 1(PDX1)and hairy and enhancer of split 1(HES1)and endodermal stem/progenitor(S/P)cell markers[CD44s,chemokine receptor type 4(CXCR4),SOX9 and epithelial cell adhesion molecule(EpCAM)]were examined immunohistochemically in 32 normal adult livers(autopsy livers)and 22 hepatolithiatic livers(surgically resected livers).The latter was characterized by the proliferation of the peribiliary glands.Immunohistochemistry was performed using formalin-fixed,paraffin-embedded tissue sections after deparaffinization.Although PDX1and HES1 were expressed in both the nucleus and cytoplasm of epithelial cells,only nuclear staining was evaluated.SOX9 was expressed in the nucleus,while CD44s,CXCR4 and EpCAM were expressed in the cell membranes.The frequency and extent of the expression of these molecules in the lining epithelia and peribiliary glands were evaluated semi-quantitatively based on the percentage of positive cells:0,1+(focal),2+(moderate)and 3+(extensive).RESULTS:In normal livers,PDX1 was infrequently expressed in the lining epithelia,but was frequently expressed in the peribiliary glands.In contrast,HES1was frequently expressed in the lining epithelia,but its expression in the peribiliary glands was focal,suggesting that the peribiliary glands retain the potential of differentiation toward the pancreas and the lining epithelia exhibit properties to inhibit such differentiation.This unique combination was also seen in hepatolithiatic livers.The expression of endodermal S/P cell markers varied in the peribiliary glands in normal livers:SOX9 and EpCAM were frequently expressed,CD44s infrequently,and CXCR4 almost not at all.The expression of these markers,particularly CD44s and CXCR4,increased in the peribiliary glands and lining epithelia in hepatolithiatic livers.This increased expression of endodermal S/P cell markers may be related to the increased production of intestinal and gastric mucin and also to the biliary neoplasia associated with the gastric and intestinal phenotypes reported in hepatolithiasis.CONCLUSION:The unique expression pattern of PDX1and HES1 and increased expression of endodermal S/P cell markers in the peribiliary glands may be involved in biliary pathophysiologies.     

Brunner's gland adenoma with a focus of p53-positive atypical glands

A submucosal tumor was resected endoscopically from the duodenal bulb in a 43-year-old man complaining of epigastric discomfort. The tumor, measuring 22 × 20 × 19 mm, consisted mainly of Brunner's glands with no atypia. However, close histologic examination disclosed a focus of glands with cellular and structural atypia. The atypical glands showed staining by periodic acid-Schiff, alcian blue, and high iron-diamine methods. Mucin histochemistry was examined, and the atypical glands resembled the excretory ducts rather than the acinar cells of the tumor. Immunohistochemically, positivity for MIB-1 was high (38.0%), and p53-positive cells were detected sporadically in the atypical glands. These results indicated that the atypical glands probably represented a neoplastic lesion. Brunner's gland adenomas associated with foci of true neoplasm are very rare; only two cases, including one patient with microcarcinoid tumors, have been reported. Received: December 3, 1998 / Accepted: June 25, 1999