Family history of gastric disease: a risk factor for intestinal metaplasia--a gastric precancerous lesion. ECP-EURONUT-Intestinal Metaplasia Study Group, UK Sub-Group

As part of a large study of the aetiology of intestinal metaplasia (IM) a questionnaire on family history was administered to patients with IM, symptomatic (and therefore endoscoped) controls (EC) and non-symptomatic (and therefore not endoscoped) controls (NC). A larger proportion of NC (47%) than of EC (23%) or IM cases (25%) had an absence of family history of gastroduodenal disease. IM cases had a stronger family history than did either control group.

Effect of Helicobacter pylori eradication on gastric metaplasia of the duodenum

Helicobacter pylori associated duodenal ulcers occur in patches of gastric metaplasia. The pathogenesis of gastric metaplasia is unclear, but it has been produced in experimental animals by acute injury and has been shown to be present to a greater extent of H pylori positive subjects. This study aimed to discover if gastric metaplasia regressed with eradication of H pylori or healing of duodenal ulcers, or both. Thirty two duodenal ulcer patients with H pylori infection confirmed by biopsy urease test and by antral histological examination were studied. Patients were treated with triple therapy (deNol 240 mg twice daily, amoxycillin 500 mg three times daily, and metronidazole 400 mg three times daily) for two weeks after the first endoscopy and were subsequently re-endoscoped. Three duodenal bulb biopsy specimens were obtained per patient at each endoscopy. Biopsy sections were stained with haematoxylin and eosin to determine the severity of duodenitis, and with diastase periodic acid-Schiff/alcian blue to assess the extent of gastric metaplasia. Slides were assessed by two histopathologists unaware of treatment status. H pylori was eradicated in 63% of subjects and all ulcers were healed at follow up. The median extent of gastric metaplasia at the start of treatment and 6-18 months (median 10) after treatment was compared in the two groups. Gastric metaplasia declined in eradicators from 16% to 8% (p < 0.05) while in non-eradicators there was no significant change (25% initially and at follow up). A positive relation between extent of gastric metaplasia and duodenal inflammation score was present before treatment (r(s) = 0.74, p < 0.001) and was unchanged after treatment in the non-eradicator group (r(s) = 0.89, p < 0.001). In the eradicator group, however, the inflammation score had significantly declined (p < 0.02) and the close relation with gastric metaplasia was no longer present. These results suggest that H pylori itself is at least in part responsible for producing gastric metaplasia of the duodenum.

Lack of any positive effect of intestinal metaplasia on induction of gastric tumors in Wistar rats treated with N-methyl-N-nitrosourea in their drinking water

The influence of intestinal metaplasia on gastric cancer induction was examined in five-week-old male Wistar:Crj rats. The animals were first treated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy) and then, starting two months after the irradiation, received 100 ppm N-methyl-N-nitrosourea (MNU) in their drinking water for 15 weeks. Thereafter they were maintained for 37 weeks with or without a dietary 1% sodium chloride (NaCl) supplement. The incidences of gastric adenocarcinomas in the MNU or MNU plus NaCl groups were significantly higher than in animals receiving X-rays plus MNU with or without NaCl. Intestinal metaplasias and the numbers of alkaline phosphatase (ALP)-positive foci were significantly increased in the X-ray irradiation groups but the numbers of ALP-positive foci were not increased with or without 1% NaCl. An inverse relationship between incidences of gastric tumors and intestinal metaplasias was apparent. The present experiment thus showed that the presence of intestinal metaplasia does not exert a positive influence on induction of gastric neoplasia by MNU in the rat.

Squamous metaplasia in the salivary glands of canaries (a case report)

Squamous metaplasia of the glandular epithelium was found in the palatine salivary glands of two canaries, originating from a flock in which there was a variable intake of egg food. The histological changes, in combination with the history, indicate a vitamin A deficiency as a result of a selective intake of food as the most likely aetiology.

Migration and maturation of Langerhans cells in squamous metaplasia of the rat trachea induced by vitamin A deficiency

The migration and maturation of Langerhans cells (LCs) in rat tracheal squamous metaplasia due to vitamin A deficiency were investigated immunohistochemically and electron microscopically. In the early stage of metaplasia, i.e. basal cell hyperplasia, no LCs with Birbeck granules (BGs) could be found, but there were desmosome-free cells which had the morphological characteristic of immature LCs. They were clearly different from inflammatory cells such as macrophages and lymphocytes, and were, therefore, considered to be precursors of LCs. In the stage of stratification, small numbers of Ia- and protein kinase C type II (PKCII)-positive cells were recognized. Ultrastructurally they were immature LCs with ovoid nuclei, many free ribosomes and few dendrites. The cytoplasm was dark and a few BGs and atypical granules (AGs) could be seen in the Golgi area. In the early stage of cornification, LCs with partially intended nuclei, prominent nucleoli and well-developed Golgi complexes were found. There were many BGs and AGs and structures transitional between them in the Golgi areas. In epithelium showing mature squamous metaplasia, many Ia- and PKCII-positive dendritic cells could be seen. Most of these were typical mature LCs with lobulated nuclei, clear cytoplasm and prominent dendritic processes. The number of BGs and AGs were fewer than in the LCs found in the early stage of cornification, and these granules were distributed throughout the cytoplasm. In the final stage, where the basal cells had differentiated into a flatter epithelium, few LCs could be seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of gastric pH modifiers on development of intestinal metaplasia induced by X-irradiation in rats

The influence of gastric pH on intestinal metaplasia was examined in male Crj:CD(SD) rats. At the age of 5 weeks, animals were irradiated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy), and 6 months after irradiation, received either secretin or histamine in silicon tubes for 2 months or had their bilateral submandibular salivary glands removed. The incidence of intestinal metaplasia in the fundus of animals after administration of secretin or histamine, or removal of the salivary glands were reduced, along with the pH values, as compared with values for rats given X-rays alone. In both the pyloric and the fundic gland mucosae, the numbers of alkaline phosphatase (ALP)-positive foci and type B metaplasias (intestinal crypts without Paneth cells) were also significantly decreased (P < 0.01). In a second experiment, started six months after irradiation, rats were kept on 1% sodium chloride (NaCl) diet for 6 months. Subsequent removal of salivary glands along with histamine treatment brought about a marked drop in pH and in numbers of ALP-positive foci after three and five days. The present results thus indicated that development and maintenance of intestinal metaplasia can be influenced by a decrease of pH value.

Chronic esophagitis and gastric metaplasia are frequent late complications of esophageal atresia

Long-term follow-up examination with esophagogastroduodenoscopy was performed on 39 esophageal atresia patients 2 to 11 years (mean, 7.6) after the anastomotic operation. Nine of these patients had undergone fundoplication for symptomatic gastroesophageal reflux. The subjective results at the last follow-up were as follows: excellent in 25, good in 10, and fair in 4 patients. The endoscopic findings were normal in 17 patients. Endoscopy of the remaining 22 patients showed esophagitis in 20, 5 associated with Barrett's change. Hiatal hernia was found in 10 patients. The fundoplication was totally or partially disrupted in 3 patients. Esophageal biopsies were obtained from 37 patients. The histological findings were as follows: esophagitis in 21, gastric metaplasia in 3, and normal esophageal mucosa in 13 patients. The endoscopic and histological findings correlated poorly with subjective results as more than half of the patients with excellent subjective results had esophagitis, one of them with gastric metaplasia. Therefore, long-term endoscopic follow-up of all esophageal atresia patients is warranted.

Expression patterns of loricrin in various species and tissues

In this study we analyzed the expression patterns of loricrin in various species and tissues using immunohistochemistry, immunoblotting and Northern blots. Loricrin is a glycine-, serine- and cysteine-rich protein expressed very late in epidermal differentiation in the granular layers of normal mouse and human epidermis. Later on in differentiation, loricrin becomes crosslinked as a major component into the cornified cell envelope by the formation of N epsilon-(gamma-glutamyl)lysine isopeptide bonds. This process either occurs directly or by the intermediate accumulation in L-keratohyaline granules of mouse epidermis and human acrosyringia. Loricrin was identified in all mammalian species analyzed by virtue of its highly conserved carboxy-terminal sequences revealing an electric mobility of approximately 60 kDa in rodents, rabbit and cow and of approximately 35 kDa in lamb and human on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Loricrin is expressed in the granular layer of all mammalian orthokeratinizing epithelia tested including oral, esophageal and fore-stomach mucosa of rodents, tracheal squamous metaplasia of vitamin A deficient hamster and estrogen induced squamous vaginal epithelium of ovary ectomized rats. Loricrin is also expressed in a few parakeratinizing epithelia such as BBN [N-butyl-N-(4-hydroxybutyl)nitrosamine]-induced murine bladder carcinoma and a restricted subset of oral and single vaginal epithelial cells in higher mammals. Our results provide further evidence that the program of squamous differentiation in internal epithelia of the upper alimentary tract in rodents and higher mammals differ remarkably. In addition, we also have noted the distinct distribution patterns of human loricrin and involucrin, another major precursor protein of the cornified cell envelope.

[Splenic megakaryocytic metaplasia in osteomyelosclerosis--case report]

An atypical case is presented of exclusive splenic megakaryocyte metaplasia in a 53-year-old man, in the course of osteomyelosclerosis. The observed case suggests a transient form of osteomyelosclerosis.

Retinoid status controls the appearance of reserve cells and keratin expression in mouse cervical epithelium

We describe an animal model to induce the histogenesis of squamous metaplasia of the cervical columnar epithelium, a condition usually preceding cervical neoplasia. This model is based on dietary retinoid depletion in female mice. Control sibling mice fed the same diet but with all-trans-retinoic acid (at 3 micrograms/g diet) showed the normal endocervical epithelial and glandular columnar morphology, typical of a simple epithelium without subcolumnar reserve cells. The stratified squamous ectocervical epithelium of these mice fed all-trans retinoic acid showed intense immunohistochemical staining in basal and suprabasal cells with mono-specific antibodies against keratins K5, K14, K6, K13, and, suprabasally, with antibodies specific for K1 and K10. At the squamocolumnar junction, the adjacent columnar epithelium (termed "suprajunctional") did not show staining for K5, K14, K6, K13, K1, and K10 but specifically stained for keratin K8, typical of simple epithelia and absent from the adjacent ectocervical squamous stratified lining (termed "subjunctional"), in striking contrast. Sections of the squamocolumnar junction from mice kept on the vitamin A-deficient diet for 10 weeks showed suprajunctional isolated patches of reserve cells, proximal and distal to the junction. These cells were detected prior to any symptoms of vitamin A deficiency, such as loss of body weight or respiratory discomfort. The subcolumnar reserve cells induced by vitamin A deficiency displayed positive staining for K5 and K14. As deficiency became severe, the reserve cells occupied the entirety of the suprajunctional basement membrane. This epithelium eventually became stratified and squamous metaplastic, the squamocolumnar junction was no longer discernible, and the entire endocervical epithelium and the endometrial glands lost K8 positivity, while acquiring K5, K14, K6, K13, K1, and K10 keratins typical of the ectocervix under normal conditions of vitamin A nutriture. Vitamin A deficiency also altered keratin expression and localization in squamous subjunctional epithelium. In situ hybridization studies for K1 and K5 mRNA showed their major site of expression at the basal (K5) and immediately suprabasal (K1) cell layers. The localization of both K5 and K1 proteins in these same cell layers, and above, is consistent with transcriptional regulation of these keratins. Early vitamin A deficiency caused the appearance of single subcolumnar reserve cells expressing K5 mRNA. After these cells grew into a squamous focus, K1 mRNA became expressed suprabasally. We conclude that retinoid status plays a key role in maintaining differentiative characteristics of the cervical and glandular epithelia and, as such, may be a modulating factor in the development of cervical cancer.

Gastric intestinal metaplasia eleven years after randomized selective proximal vagotomy for peptic ulcer

The presence of intestinal metaplasia (IM) 11 years after selective proximal vagotomy (SPV), selective proximal vagotomy with pyloroplasty (SPV + PP) and selective vagotomy with pyloroplasty (SV + PP) was investigated in 38 consecutive patients. IM was significantly more frequent in SPV than in SV + PP, SPV + PP or in unoperated controls of matching ages. IM occurred more frequently both at an older age (> or = 60 years) in SPV and in a larger number of gastric areas than in the other group of patients. Reports in the literature indicate that vagotomy may increase the risk of gastric carcinoma and that IM may antedate malignant transformation. It would thus appear that patients previously operated with SPV (without pyloroplasty) having IM, should be the group of patients to be enrolled in endoscopical surveillance programs for detection of possible cancer development.

Pathology of the pancreas in bone marrow transplant patients

Review of 51 autopsy cases of patients receiving high-dose chemotherapy followed by bone marrow transplantation revealed a high prevalence of pancreatic ductal and acinar changes compared with control groups. Forty-five percent (23 of 51) of bone marrow transplant cases had squamous metaplasia of the pancreatic ducts compared with 10% of randomly selected control cases. Although squamous metaplasia was more common in bone marrow transplant patients receiving chemotherapy, it was not associated with whole body radiation, allogeneic transplantation, or specific drugs. Squamous metaplasia was more common in patients dying 30 days or more after transplantation. Dilatation of the pancreatic acini was present in 78.4% of transplant cases, 35.0% of control cases, and 50.0% of a group of 12 breast cancer patients treated with conventional doses of chemotherapy without bone marrow transplantation. This lesion was associated with uremia. Oncocytic change of the acinar epithelium was present in 52.9% of transplant cases, no control cases, and 41.7% of breast cancer cases. Squamous metaplasia of the pancreas is common in bone marrow transplant patients receiving high-dose chemotherapy and may be a late manifestation of toxic injury to the ducts. A high prevalence of acinar dilatation was associated with terminal uremia. Oncocytic change of acinar epithelium was associated with chemotherapy.

Inhibition of lipopolysaccharide-induced pulmonary emphysema by intratracheally instilled recombinant secretory leukocyte proteinase inhibitor

Experiments were performed to test whether recombinant secretory leukocyte proteinase inhibitor (rSLPI) was able to prevent the development of lipopolysaccharide (LPS)-mediated pulmonary emphysema, hemorrhage, and secretory cell metaplasia (SCM) in hamsters. Several groups of eight animals were intratracheally treated for four weeks, twice a week with 0.5 mg Escherichia coli LPS or with saline. In the first experiment, an additional group of eight hamsters was treated with 0.5 mg LPS mixed with 0.5 mg rSLPI, and the animals received another instillation of 0.5 mg rSLPI 7 h later. In the second experiment, 0.5 mg LPS, mixed with 1 mg rSLPI, was given while additional instillations of 1 mg rSLPI were performed 7 h and 31 h after the first dosage. In the third experiment, 0.5 mg LPS, mixed with 0.5, 1.5, or 3.0 mg rSLPI, was given while additional instillations of 0.5, 1.5, and 3.0 mg rSLPI, respectively, were performed 24 h and 48 h after the first dosage. Hamster lungs were examined for emphysema, hemorrhage, and SCM. In all three series of experiments, we observed a significant inhibition of LPS-mediated emphysema by rSLPI. This inhibition tended to be dose related. Inconclusive results were obtained on the inhibition of LPS-mediated hemorrhage. The development of LPS-mediated SCM was not affected by rSLPI. The LPS-mediated polymorphonuclear leukocyte (PMN) influx did not change when administrations of rSLPI were given additionally. We conclude that rSLPI is able to diminish significantly the development of LPS-mediated pulmonary emphysema in hamsters.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of sodium chloride, miso or ethanol on development of intestinal metaplasia after X-irradiation of the rat glandular stomach

The influence of sodium chloride (NaCl), miso (Japanese soybean paste) and ethanol on development of intestinal metaplasia was examined. Five-week-old male CD(SD): Crj rats were treated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy). After irradiation, the rats received supplementation with NaCl (1% or 10% in diet), miso (10% in diet) or ethanol (10% in drinking water) for 12 months. The number of alkaline phosphatase-positive foci of intestinal metaplasia in rats given 1% NaCl diet (Group 3) after X-rays was significantly elevated as compared to that in rats given X-rays alone (Group 1) (P < 0.01) or X-rays with 10% NaCl (Group 2) (P < 0.01). In the pyloric gland mucosae, the total numbers of metaplastic foci in rats of Group 3 were much higher than in Group 2, or after miso diet (Group 4) or ethanol supplementation (Group 5) (P < 0.01), but no difference was found between Group 2, 4 or 5 and Group 1. Atypical hyperplasia only appeared at incidences of less than 6% in Groups 1-3 and no promoting effect on gastric tumorigenesis was evident in Group 2. The present results thus showed that the occurrence of intestinal metaplasia induced by X-irradiation can be significantly increased by administration of 1% NaCl and decreased by 10% NaCl and ethanol, but this is not associated with any influence on gastric neoplasia.

[Keratinizing desquamative malpighian metaplasia of the kidney pelvis. Report of a case]

We report a case of keratinizing desquamative squamous metaplasia (KDSM) of the kidney pelvis. The etiopathogenic and diagnostic aspects of this rare pathology are discussed. Absence of relationship between KDSM and the carcinoma of Upper Urinary Tract, allows to suggest a conservative management.

Retinoid status and the control of keratin expression and adhesion during the histogenesis of squamous metaplasia of tracheal epithelium

We induced vitamin A depletion to define early and late changes during the histogenesis of squamous metaplasia of hamster tracheal epithelium. An early change is the "minimal morphological change" (MMC), in which the mucociliary epithelium is separated from the basement membrane by a continuous layer of basal cells. Immunohistochemistry showed an exclusive localization of the keratins K5 and K14 in basal cells of normal and MMC epithelia. At the MMC stage no staining was observed above the basal layer with antibodies to K5, but upon progression of the lesion to a squamous focus all cells from basal to terminally differentiated were positive for K5 and K14. In contrast, when we used antibodies to the keratins K6 or K13 all cells were negative in the normal epithelium and in the MMC epithelium. Successive layers of suprabasal squamous cells found in squamous metaplasia failed to express normal epidermal differentiation marker keratins K1 and K10 but expressed the proliferation marker keratin K6 and the internal stratified epithelium keratin K13, not normally found in the epidermis or in the trachea. Hamster tracheal epithelial cells could be maintained in culture in serum-free medium for at least 4 weeks in the presence of retinoic acid (RA). In non-RA-containing medium, cells from vitamin A-deficient hamsters showed markedly reduced growth and an increase in the expression of keratins K5, K6, K13, and K14. Since our previous work had implicated retinoids in the control of cell adhesiveness, we were interested to find out whether changes in cell adhesion occur in vitamin A-deficient hamster tracheal epithelial cells, compared to normal cells. Functional assays demonstrated that hamster tracheal epithelial cells, obtained from non-RA-treated tracheas or maintained in culture, displayed reduced attachment to laminin, compared to RA-treated cells. Immunofluorescence studies did not show a decrease either in the alpha 6 integrin subunit, which was localized in the basal aspect of basal cells, or in basement membrane laminin. However, the expression of laminin-binding protein 37 decreased as the epithelium changed from pseudostratified to stratified. Therefore, a coordinated pattern of changes in keratin gene expression, as well as in the expression of laminin-binding protein 37, the precursor to the cell surface laminin receptor 67LR, and in adhesive properties takes place in tracheal epithelium when its phenotype changes from mucociliary to the preneoplastic stage of squamous metaplasia.

Cone biopsy causes cervical endometriosis and tubo-endometrioid metaplasia

Cervices from 42 hysterectomies performed from 1 to 91 months (mean 12.2) following conization were re-examined in order to assess the possible effects of post-traumatic regeneration on the endocervix. Twenty-nine (69%) showed a continuum of abnormalities in which the shared finding was the presence of tubo-endometrioid glands, accompanied in many cases by varying amounts of endometrial-type stroma. Thus, 18 post-conization cervices (43%) showed endometriosis, and a further 11 cases (26%) contained tubo-endometrioid glands without demonstrable endometrial-type stroma. These abnormalities were situated at the healed cone biopsy site, either superficially within the new transformation zone and/or within the cone biopsy scar. Post-conization cervical endometriosis occurred from 2 to 91 months (mean 17.8) and tubo-endometrioid metaplasia 2-24 months (mean 11.0) after the cone biopsy. It is concluded that cervical endometriosis and tubo-endometrioid metaplasia are common complications of conization, and that they represent aberrant differentiation following injury. The demonstration of endometriosis and tubo-endometrioid metaplasia in 69% of post-conization cervices has implications for the interpretation of cervical biopsies and smears from this group of women.

Comparative histopathological findings in the pancreas of cigarette smokers and non-smokers

Although a correlation has been suggested between cigarette smoking and pancreatic cancer, studies on pathological changes in the pancreas of smokers are fragmentary. In the present study we examined histopathologically 73 pancreases obtained by autopsy from 42 heavy cigarette smokers and 31 non-smoker patients. One invasive adenocarcinoma (2 cm in diameter) and three small carcinomas (2-5 mm in diameter) were found in smokers and one small carcinoma in a non-smoker patient. Although the incidence of pancreatic cancer in smokers was higher than in non-smokers, the difference was statistically not significant. Of smokers with pancreatic cancer, 2 had lung cancer, 1 skin cancer, 1 colon cancer and 1 was free of any malignancies. Ductal changes, including mucinous or squamous cell metaplasia and papillary hyperplasia, were found with equal frequencies in both groups of patients. The type and the incidence of these ductal alterations were not related to smoking but to the age. Our results do not indicate that cigarette smoking increases the incidence of pancreatic cancer, although, the limited number of the sections of the pancreas examined, as well as exclusion of other important variables, such as alcohol, diet and diabetes weaken the value of this study.

Cartilaginous metaplasia of the epiglottis

Metaplastic elastic cartilaginous tissue has been described in the vocal cord, vestibular fold and ventricle of the larynx. This report documents a case in which cartilaginous metaplasia developed in the soft tissue of the epiglottis following an episode of epiglottitis.

Impact of diet and smoking on risk of developing intestinal metaplasia of the stomach

A cohort of Hawaii Japanese men was assembled for epidemiologic studies of heart disease and cancer. Diet and tobacco consumption data were obtained from 1965 to 1968 and from 1971 to 1975. Biopsies from sites at maximal, intermediate, and minimal risk of intestinal metaplasia were performed on 350 men. Metaplasia was found in 234 men. Gastric cancer was found in 9/234 with metaplasia (3.8%) and 1/116 men without metaplasia (0.89%). Nitrite-rich salty foods (e.g., cured meats) were directly related to metaplasia at both examinations. Vitamin C intake did not appear to have prevented the development of intestinal metaplasia. Smoking was directly related to the presence of metaplasia, but the association was weaker than was observed for cured meats. The strong association between nitrite-rich salty foods and metaplasia appears to be uniform from one study to another, as is the lack of a consistent relation between metaplasia and either smoking or vitamin C consumption. Heavy smokers were more likely to have metaplasia than were nonsmokers, but these associations were weaker than were those with cured meats.

Lipomatous neometaplasia of the uterus. Report of 11 cases with discussion of histogenesis and pathogenesis

Eleven cases of uterine lipomatous neometaplasia were studied. The patients ranged in age from 41 to 74 years (mean, 56.6 years). There were eight lipoleiomyomas and 3 angiolipoleiomyomas. In eight tumors the lipomatous component consisted only of mature lipocytes. In three tumors, pericapillary differentiating lipocytes also occurred. No correlation between the proportion of the lipomatous and leiomyomatous components and the size of tumor was observed. There was also no correlation between the amount and distribution of the lipomatous component and the hyalinized fibrous stroma. The levels of cytosolic estrogen and progesterone receptors, studied in one case, were lower in the lipoleiomyoma than in the myometrium. Leiomyomas and adenomyosis were the most frequent accompanying lesions. The study supports a notion that uterine lipomatous neometaplasia originates from pericapillary pluripotential mesenchymal cells. Present findings suggest that lipomatous differentiation of immature neoplastic cells can occur in a preexisting leiomyoma, as well as simultaneously with leiomyomatous differentiation.

Adenoma and stone formation of the biliary tract in puppies that had choledochopancreatic anastomosis

A canine model of anomalous choledochopancreatic ductal junction (APCDJ) was produced by choledochopancreatic end to side ductal anastomosis performed in 77 mongrel puppies weighing between 1.5 and 5 kg. Histopathological studies of the biliary tract showed that as the post-operative period became lengthened metaplasia and hyperplasia increased. In nine dogs that lived for over 5 years after the operation, papillomatous adenoma occurred in four (44%), and biliary stones in seven (78%). The histological changes seen in the biliary epithelium of our experimental canine model suggest that bile duct carcinoma may be due to the persistent return of pancreatic juice into the bile duct in patients with APCDJ.

Intestinal metaplasia and dysplasia of prostatic urethra secondary to stricture

We report a case of intestinal metaplasia and dysplasia (villous adenoma) of the prostatic urethra secondary to stricture of the prostatic portion of the urethra and chronic inflammation. This sequence of events has previously been recognized in the urothelium of the bladder as a precursor of adenocarcinoma of intestinal type. Premalignant dysplasia of glandular type is rare in the urethra, as is adenocarcinoma, and this case suggests that the pathway to some adenocarcinomas of the urethra may be through intestinal metaplasia and dysplasia similar to the process recognized in the stomach, nose, and urinary bladder.

The effects of ranitidine and cysteamine on intestinal metaplasia induced by X-irradiation in rats

The influence of ranitidine and cysteamine on intestinal metaplasia was examined in 7-month-old male Crj: CD (SD) rats. At the age of 5 weeks, the animals were treated with 10 Gy doses of X-rays at 3-day intervals up to a total of 20 Gy in the gastric region, and 6 months after irradiation, the rats received either ranitidine (0.02% in diet) or cysteamine (0.1% in drinking water) for 2 months. The incidence and number of intestinal metaplasia with alkaline phosphatase-positive foci in rats given X-rays and cysteamine (group 4) were significantly low compared with those in rats given X-rays and ranitidine (group 3) (p less than 0.01). In both the pyloric and the fundic gland mucosae, the average numbers of type C metaplasia (intestinal crypts with Paneth cells) and total numbers of metaplastic foci in rats of group 3 were much higher than those in group 4 (P less than 0.05). The present results showed that the occurrence of intestinal metaplasia was significantly increased after administration of ranitidine and decreased by cysteamine.