Aberrant Expression and Glycosylation of Mucins in Gastric Mucosal Disease / 中国医学科学院学报

Mucins,a family of heavily glycosylated proteins,present mainly in epithelial cells.They function as essential barriers for epithelium and play important roles in cellular physiological processes.Aberrant expression and glycosylation of mucins in gastric epithelium occur at pathological conditions,such as Helicobacter pylori infection,chronic atrophic gastritis,intestinal metastasis,dysplasia,and gastric cancer.This review addresses the major roles played by mucins and associated O-glycan structures in normal gastric epithelium.Further,we expound the alterations of expression patterns and glycan signatures of mucins at those pathological conditions.

Histochemical assessment of mucin-secreting cells in the stomach of domestic rabbit / Evaluación histoquímica de células secretoras de mucina en el estómago de conejo doméstico

SUMMARY: The mucous substances of the stomach in mammals are important not only for the protection of the gastric epithelium from the acid environment and grinding actions, but it facilitates some other functions of the stomach such as antibacterial, antimetastatic, and immunological roles. The goal of the study is to highlight the distribution of mucin-secreting cells in the gastric mucosa in domestic rabbits, including the type of mucus synthesized. The gastric samples collected from ten individual rabbits were fixed in 10 % buffered formalin and underwent later standard paraffin tissue sample processing, which included dehydration, clarification, and embedding in paraffin. The tissue sections were eventually stained histochemically by PAS reaction and by Alcian blue method (pH 2.5) for neutral and acidic mucins detection, respectively. The quantification of mucins in the cytoplasm of mucus-secreting cells was performed by grading the gastric tissue samples from negative (-) to intensely positive (++). The mucus elaboration was observed in all the regions of the stomach (i.e., cardial, fundic, and pyloric regions), but only for the neutral mucin. The acidic mucin synthesis occurred only in the secretory units of the gastric glands from the cardial region in the stomach. Pyloric glands synthesized the largest amounts of neutral mucins, followed by moderate amounts elaborated by cardial glands, while the fundic region does not synthesize it at all. The description of new microscopic features of the stomach in rabbits is fundamental not only for comprehending species-related physiological features but gastric pathological processes.

RESUMEN: Las sustancias mucosas del estómago en los mamíferos son importantes no solo para la protección del epitelio gástrico del ambiente ácido y las acciones de trituración, sino que facilitan además otras funciones del estómago, como son las funciones antibacterianas, antimetastásicas e inmunológicas. El objetivo del estudio fue resaltar la distribución de las células secretoras de mucina en la mucosa gástrica de conejos domésticos, incluido el tipo de moco sintetizado. Las muestras gástricas recolectadas de diez conejos se fijaron en formalina tamponada al 10 % y se sometieron a un procesamiento que incluyó deshidratación, clarificación e inclusión en parafina. Las secciones de tejido finalmente se tiñeron histoquímicamente mediante la reacción de PAS y el método del azul de Alcian (pH 2,5) para la detección de mucinas neutras y ácidas, respectivamente. La cuantificación de mucinas en el citoplasma de las células secretoras de moco se realizó clasificando las muestras de tejido gástrico desde negativas (-) hasta intensamente positivas (++). La elaboración de moco se observó en todas las regiones del estómago (es decir, cardias, fúndica y pilórica), pero solo para la mucina neutra. La síntesis de mucina ácida ocurrió solo en las unidades secretoras de las glándulas gástricas de la región correspondiente al cardias del estómago. Las glándulas pilóricas sintetizaron la mayor cantidad de mucinas neutras, seguidas de cantidades moderadas elaboradas por las glándulas cardiales, mientras que la región fúndica no las sintetizó en abso- luto. La descripción de nuevas características microscópicas del estómago en conejos es fundamental no solo para comprender las características fisiológicas relacionadas con las especies sino también para entender los procesos patológicos gástricos.

Is the colon mucosa affected by ten days of gastric restriction in an animal model?

Abstract Purpose To identify whether the colon mucosa is affected by ten days of gastric restriction in an animal model. Methods An experimental model of gastric restriction was devised using rats. The animals were submitted to surgical gastrostomy, and a cylindrical loofah was inserted into the stomach. We studied 30 adult male Wistar rats divided into three groups: the stomach restriction group (R10); the sham group (S10), which underwent the same procedure except for the loofah insertion; and the control group (C10). The expression of neutral and acid mucins was evaluated using histochemical techniques. Goblet cells and protein content were compared between groups using generalized estimation equations (GEEs). Bonferroni's multiple comparison was applied to identify differences between the groups. All tests considered a 5% significance level. Results There was an increased expression of neutral mucins, acid mucins and goblet cells in the R10 group. Collagen was also enhanced in the R10 group. Conclusion The colon mucosa is affected by ten days of gastric restriction in an animal model, increasing neutral mucins, acid mucins and collagen content with trophic maintenance.

Scanning electron microscopy of granuloma annulare

Abstract: Light microscopy of granuloma annulare shows mucin deposition with lympho-histiocytic infiltrate. We describe the ultrastructural three-dimensional aspects of a typical case of granuloma with characteristic histopathological findings. At the ultrastructural level, affected collagen bundles and granular mucin deposition were observed. Round cells corresponding to lymphocytes were identified. Bigger oval cells, corresponding to isolated or palisading histiocytes were also found. The ultrastructural aspects overlap with light microscopy and contribute to its iconographic documentation.

Scleromyxedema: clinical diagnosis and autopsy findings

Abstract Scleromyxedema is a rare chronic cutaneous mucinosis of unknown etiology. It is characterized by papular eruption and scleroderma with microscopic evidence of mucin deposition, fibroblast proliferation, and fibrosis. Most patients with scleromyxedema have monoclonal gammopathy and systemic manifestations resulting in significant morbidity and mortality. Several types of treatment have been reported with partial or inconsistent responses. Despite showing unpredictable evolution, systemic consequences of scleromyxedema and treatment side effects may result in death. We describe a rare case of a patient with scleromyxedema without paraproteinemia with systemic involvement that evolved to death despite treatment with cyclophosphamide.

Adhesion molecules in breast carcinoma: a challenge to the pathologist / Moléculas de adesão no carcinoma mamário: um desafio ao patologista

The role of adhesion molecules is very important both in the activation of carcinogenesis and in the differentiation of subtypes of breast carcinoma, aiding in diagnosis, prognosis and therapeutic choice in these tumors. Therefore, understanding the functions and interrelationships among these molecules is crucial to the pathologist, who often uses these factors as a resource to differentiate tumors and further classify them according to a molecular point of view. Our goal is to describe the applicability and the difficulties encountered by the pathologist in the diagnosis of breast carcinoma, discussing the most commonly used markers of adhesion in routine analyses.

O papel das moléculas de adesão é de suma importância tanto na ativação da carcinogênese quanto na diferenciação dos subtipos de carcinomas mamários, auxiliando no diagnóstico, no prognóstico e na escolha terapêutica nessas neoplasias. Portanto, a compreensão das funções e das inter-relações entre essas moléculas é de suma importância para o patologista, que, muitas vezes, as utiliza como recurso na diferenciação dos tumores e, consequentemente, elas auxiliam em uma posterior classificação do ponto de vista molecular. O objetivo é descrever a aplicabilidade e as dificuldades encontradas pelo médico patologista no diagnóstico de carcinoma mamário, discutindo os marcadores de adesividade mais utilizados na rotina.

Molecular markess of mucosa harboring gastric adenoass

Context Gastric adenoma is a precursor lesion of the adenocarcinoma. Objective To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma. Methods Forty gastric specimens from 20 patients were classified as intestinal (MUC2 - goblet cell mucin) or foveolar (MUC5AC - gastric-foveolar mucin) adenomas. Immunohistochemistry was performed using streptavidin-biotin-complex method. Results Twelve (60%) patients were men. The mean age was 67.9 ± 12.9 years-old. Intestinal adenomas were detected in 13 (65%) patients and gastric type in 7 (35%). Low-grade dysplasia was present in 13 (65%) of the adenomas, high-grade in 3 (15%), and adenocarcinoma within the polyp in 4 (20%). Six (30%) patients had synchronous adenocarcinoma. p53 immunoexpression was observed in 6/20 (30%) of adenomas, and in 2/6 (33.3%) of synchronous tumors. There was an association between p53 immunoexpression and intestinal type of adenoma/tumor, P = 0.04. There was no association between p16ink4a, Bcl-2, cyclin D and Ki-67 and adenoma clinicopathological characteristics. Conclusion Immunohistochemistry may be useful to classify the adenomas subtypes and may define the pathway of adenoma to carcinoma sequence. .

Contexto Adenoma gástrico é uma lesão precursora do adenocarcinoma. Objetivo Melhor caracterizar os adenomas de acordo com a imunoexpressão de mucinas e avaliar a imunoexpressão de p53, p16ink4a, BCL-2, cyclin D, Ki-67, nos adenomas e na mucosa gástrica adjacente. Métodos Quarenta espécimes gástricos provenientes de 20 pacientes portadores de adenomas foram classificados como do tipo intestinal (MUC2 – mucina presente nas células caliciformes) ou gástrico (MUC5AC – mucinas de padrão foveolar). Realizou-se imunoistoquímica para p53, p16ink4a, BCL-2, cyclin D e Ki-67 pelo método do complexo da estreptavidina-biotina. Resultados Doze (60%) pacientes eram homens e a média de idade foi de 67,9 ± 12,9 anos. Os adenomas foram classificados como do tipo intestinal em 13 (65%) pacientes e do tipo gástrico em 7 (35%). Displasia (neoplasia intraepitelial) de baixo grau estava presente em 13 (65%), displasia de alto grau em 3 (15%), e adenocarcinoma no pólipo adenomatoso em 4 (20%) pacientes. Observou-se immunoexpressão do p53 em 6/20 (30%) adenomas, e em 2/6 (33,3%) dos tumores sincrônicos. Houve associação entre imunoexpressão do p53 e adenoma/tumor tipo intestinal, P = 0.04. Não houve associação entre imunoexpressão do p16ink4a, Bcl-2, ciclina D e Ki-67 e as características clinicopatológicas dos adenomas. Conclusão Imunoistoquímica pode ser utilizada para caracterizar os subtipos de adenoma e talvez indicar o caminho de carcinogênese. .

Evaluation of Plasma Vitamin A and E Levels and Tear Film Changes in Patients with Psoriasis Vulgaris

PURPOSE: To evaluate whether alterations in plasma vitamin A and E levels in patients with psoriasis have an effect on tear film changes. METHODS: Sixty-two eyes of 31 patients with psoriasis vulgaris (Group A) and 74 eyes of 37 age- and gender-matched control subjects (Group B) were included in the study. Ocular and medical histories and dietary habits were obtained from each patient. The tear film break-up time (TBUT), the Schirmer 1 test results and plasma vitamin A and E levels were evaluated. RESULTS: The mean Schirmer 1 test score was 14.76 +/- 6.12 mm/5 min in Group A and 15.69 +/- 3.10 mm/5 min in Group B. The mean plasma levels of vitamins A and E in Groups A and B were 1.86 +/- 0.62 micromol/L and 1.88 +/- 0.65 micromol/L vs. 26.21 +/- 5.13 micromol/L and 27.19 +/- 8.89 micromol/L, respectively. The Schirmer 1 test results and plasma vitamin A and E levels were not found to be significantly different between the groups (p > 0.05). The mean TBUT was 9.94 +/- 6.18 seconds in Group A and 14.47 +/- 5.65 seconds in Group B, a significant difference (p 0.05). CONCLUSIONS: Plasma vitamin A and E levels do not seem to be related to tear film changes in patients with psoriasis vulgaris.

A Case of Colloid Carcinoma Arising in Association with Intraductal Papillary Neoplasm of the Liver / 대한소화기학회지

Colloid carcinoma of the liver is very rare, and its clinicopathologic features have not been well characterized yet. We describe herein a case of colloid carcinoma of the liver. Imaging revealed a lobulated mass, measuring 12 cm in diameter at the right lobe of the liver with direct invasion of adjacent peripheral intrahepatic bile ducts. Right hemihepatectomy of the liver was performed according to the possibility of the tumor's malignant behavior. Histopathological examination of the specimen revealed large extracelluar stromal mucin pools containing floating cuboidal to columnar neoplastic cells without ovarian-like stroma. This case seemed to be colloid carcinoma arising in association with intraductal papillary neoplasm of the liver.

The esophagus of the crocodilian Caiman latirostris (Reptilia, Crocodylia ): histologia, histochemical, and immunohistochemical study

The purpose of this study was to analyze the esophageal morphology of Caiman latirostris using histochemicaland immunohistochemical techniques. The mucosae layer is composed of a pseudostratified columnarepithelium with goblet cells that occasionally form intra-epithelial glands. The goblet cells showed differentaffinity for the histochemical techniques. The lamina propria is composed of loose connective tissue with bloodvessels. The smooth muscle fibers that compose the muscularis mucosa are thick and form a clear demarcationbetween the mucosa layer and adjacent submucosa. There are no glands in the esophageal submucosa. Themuscle layer is composed a circular internal layer and a longitudinal external one. The adventitia layer iscomposed of loose connective tissue and blood vessels. The serotonin immunoreactive (IR) cells were notpreferentially distributed in any region of the epithelium, ranging from the base of the intra-epithelial gland tothe connection to the lumen. Somatostatina, glucagon and CCK IR cells were not detected.

Quantification by computerized morphometry of tissue levels of sulfomucins and sialomucins in diversion colitis in rats / Quantificação por morfometria computadorizada dos níveis teciduais de sulfomucinas e sialomucinas na colite de exclusão em ratos

PURPOSE: To quantify the intensity of sulfomucin and sialomucin expression in the colon mucosa, by means of computer-assisted image processing, comparing segments with and without fecal stream and correlating with the duration of fecal transit exclusion. METHODS: Forty-five Wistar rats were subjected to diversion of the fecal stream in the left colon by means of constructing a proximal colostomy and distal mucosal fistula. They were distributed randomly into three experimental groups of 15 animals, of which 10 were subjected to colon diversion (experimental subgroup) and five were only subjected to laparotomy, without colon diversion (control subgroup). The three experimental groups were formed according to the sacrifice date, which was to be performed six weeks after the surgical procedure (Group A), 12 weeks (Group B) and 18 weeks (Group C). The sulfomucin and sialomucin expression in the colon mucosa was evaluated using the histochemical technique of high iron diamine-alcian blue (HID-AB). The tissue expression was quantified for each animal, in the segments with and without fecal stream, at a location where there were four complete contiguous crypts in two random fields, with the aid of the computer-assisted image analysis software. The final value was taken to be the mean reading from the two fields selected, in the segments with and without fecal stream. To compare the expressions of the two mucin subtypes in the segments with and without fecal stream, the paired Student t test was used. To analyze variance according to duration of exclusion, ANOVA with the Newman-Keuls post-test was used, setting the significance level at 5 percent (p<0.05). RESULTS: There were significant reductions in tissue sulfomucin and sialomucin content in the colon without fecal stream, independent of the duration of exclusion considered. There was increased tissue sulfomucin content and decreased tissue sialomucin in the segments without fecal stream, ...

OBJETIVO: Quantificar, por meio de processamento de imagem assistida por computador, a intensidade de expressão de sulfomucinas e sialomucinas na mucosa cólica comparando segmentos com e sem trânsito e relacionando-a ao tempo de exclusão de trânsito fecal. MÉTODOS: Quarenta e cinco ratos Wistar machos foram submetidos à derivação do trânsito no cólon esquerdo pela confecção de colostomia proximal e fístula mucosa distal. Foram divididos de forma randomizada em três grupos experimentais de 15 animais, nos quais 10 foram submetidos à derivação do trânsito cólico (subgrupo experimental) e cinco somente a laparotomia exploradora sem desvio do trânsito fecal (subgrupo controle). Os três grupos experimentais foram formados segundo o sacrifício ter sido realizado em seis (grupo A), 12 (Grupo B) e 18 semanas (Grupo C). A avaliação da expressão de sulfomucinas e sialomucinas na mucosa cólica foi realizada pela técnica histoquímica da diamina de ferro alto alcian-blue (HID-AB). A quantificação da expressão tecidual foi determinada, para cada animal, nos segmentos com e sem trânsito, em local onde existiam quatro criptas contíguas e íntegras em dois campos aleatórios com auxílio de programa de análise de imagem assistida por computador. Adotou-se como valor final a média das leituras dos dois campos selecionados, nos segmentos providos e desprovidos de trânsito fecal. Na comparação entre a expressão dos dois subtipos de mucinas nos segmentos com e sem trânsito fecal utilizou-se o teste t de Student pareado. Para análise de variância segundo o tempo de exclusão utilizou-se o teste de ANOVA com o pós-teste de Newmann-Keuls, estabelecendo-se nível de significância de 5 por cento (p<0,05). RESULTADOS: Houve redução significante no conteúdo tecidual de sulfomucinas e sialomucinas no cólon desprovido de trânsito fecal, independente do tempo de exclusão considerado. Houve aumento no conteúdo tecidual de sulfomucinas e diminuição de sialomucinas nos segmentos ...

Culture & characterisation of limbal epithelial cells & oral mucosal cells.

Background & objectives: Sources of autologous tissue that can functionally replace the corneal epithelium have been considered as an alternative to allogenous limbal transplants for limbal stem cells deficiency (LSCD). The aim of the present study was to compare the characterization of oral mucosa with limbal epithelial cells by markers using reverse transcriptase polymerase chain reaction (RT-PCR). Methods: Experiments were performed using oral tissue (n=6) obtained from patients who underwent oral mucosal graft for LSCD. Confluent cultures of limbus and oral mucosa epithelial cells were characterized by the pututative stem cell markers using RT-PCR. The morphological characteristics of cultivated epithelial cells were analyzed by haematoxylin and eosin staining and phase contrast microscopy. Results: Confluent sheets of epithelial cells were seen at the end of 14th day resembling the morphological features of limbal epithelia. RT–PCR analysis showed that cultured oral epithelial cells expressed markers such as ABCG2, p63, delta Np63, isoforms of p63, Keratin 3 (K3), membrane protein – Mucin (MUC 1, 4 and 16) and Antimicrobial Peptide - AMP (Human β Defensin – hBD 1, 2 and 3). Interpretation & conclusions: Oral epithelial cultures have morphological features resembling corneal and limbal epithelial cells by expressing similar marker genes. Thus, feasibility of clinical use of oral epithelial cells need be evaluated for allogenous limbal transplants.

Functional activities of the Tsh protein from avian pathogenic Escherichia coli (APEC) strains

The temperature-sensitive hemagglutinin (Tsh) expressed by strains of avian pathogenic Escherichia (E.) coli (APEC) has both agglutinin and protease activities. Tsh is synthesized as a 140 kDa precursor protein, whose processing results in a 106 kDa passenger domain (Tsh(s)) and a 33 kDa beta-domain (Tsh(beta)). In this study, both recombinant Tsh (rTsh) and supernatants from APEC, which contain Tsh(s) (106 kDa), caused proteolysis of chicken tracheal mucin. Both rTsh (140 kDa) and pellets from wild-type APEC, which contain Tsh(beta) (33 kDa), agglutinated chicken erythrocytes. On Western blots, the anti-rTsh antibody recognized the rTsh and 106 kDa proteins in recombinant E. coli BL21/pET 101-Tsh and in the supernatants from APEC grown at either 37degrees C or 42degrees C. Anti-rTsh also recognized a 33 kDa protein in the pellets from APEC13 cultures grown in either Luria-Bertani agar, colonization factor antigen agar, or mucin agar at either 26degrees C, 37degrees C, or 42degrees C, and in the extracts of outer membrane proteins of APEC. The 106 kDa protein was more evident when the bacteria were grown at 37degrees C in mucin agar, and it was not detected when the bacteria were grown at 26degrees C in any of the culture media used in this study. Chicken anti-Tsh serum inhibited hemagglutinating and mucinolytic activities of strain APEC13 and recombinant E. coli BL21/pET101-Tsh. This work suggests that the mucinolytic activity of Tsh might be important for the colonization of the avian tracheal mucous environment by APEC.

A Case of Macroscopically Unvisualized Mucin-hypersecreting Biliary Papillomatosis Diagnosed by Microscopy / 대한소화기학회지

The mucin-hypersecreting biliary papillomatosis is a premalignant neoplasm characterized by intraductal papillary proliferation involving extensive areas of the intrahepatic and/or extrahepatic bile duct. We report a case of mucin-hypersecreting biliary papillomatosis manifested as obstructive jaundice and diagnosed only by microscopy, with a review of literatures. A 74-year-old female, who had a past history of cholecystectomy about 13 years ago, was admitted to our hospital with jaundice. A CT scan showed marked dilatation of intrahepatic and extrahepatic bile duct without intraductal filling defect or extrabiliary mass. During endoscopic retrograde cholangiopancreatography, mucin extrusion from the duodenal major papilla and dilated common bile duct with amorphous filling defects was noted. Percutaneous transhepatic biliary drainage for cholangioscopy was failed. In the operation field, there was a lot of mucin but was no visible mass at the common bile duct with bare eyes and cholangioscopy. However, papilloma was detected at the random biopsy specimen by microscopy. The patient underwent partial resection of common bile duct and choledocho-jejunal anastomosis.

Mucin-producing signet ring cell adenoma of the thyroid.

Signet ring cell adenoma of the thyroid, though rare, is well documented. This change is chiefly due to intracellular accumulation of thyroglobulin that appears mucinous. Awareness of this entity is important as it may closely simulate a metastatic mucin-secreting signet ring cell carcinoma. Although the mucinous material in signet ring cells has been reported to stain positive with thyroglobulin, in some cases it may not be so. We herein describe a rare case of a 46-year-old man who was hypothyroid and the mass removed from the thyroid showed a mucin-producing signet ring cell adenoma of the thyroid.

Mucin hypersecreting cholangiocarcinoma / 대한간학회지

No abstract available.

Identifying a risk profile for thyroid cancer

The large use of simple and effective diagnostic tools has significantly contributed to the increase in diagnosis of thyroid cancer over the past years. However, there is compelling evidence that most micropapillary carcinomas have an indolent behavior and may never evolve into clinical cancers. Therefore, there is an urgent need for new tools able to predict which thyroid cancers will remain silent, and which thyroid cancers will present an aggressive behavior. There are a number of well-established clinical predictors of malignancy and recent studies have suggested that some of the patientÆs laboratory data and image methods may be useful. Molecular markers have also been increasingly tested and some of them appear to be very promising, such as BRAF, a few GST genes and p53 polymorphisms. In addition, modern tools, such as immunocytochemical markers, and the measure of the fractal nature of chromatin organization may increase the specificity of the pathological diagnosis of malignancy and help ascertain the prognosis. Guidelines designed to select nodules for further evaluation, as well as new methods aimed at distinguishing carcinomas of higher aggressiveness among the usually indolent thyroid tumors are an utmost necessity.

O uso cada vez mais freqüente de métodos diagnósticos simples e efetivos tem contribuído significativamente para um aumento no diagnóstico de câncer da tiróide nos últimos anos. Entretanto, existem importantes evidências de que muitos dos microcarcinomas papilíferos têm um comportamento indolente e podem nunca evoluir para cânceres clínicos. Existe, portanto, uma necessidade urgente de desenvolver novas ferramentas capazes de predizer quais os tumores tiroidianos que permanecerão silenciosos e quais desenvolverão comportamento agressivo. Há uma série de marcadores clínicos de evolução bem estabelecidos e alguns estudos recentes sugerem que dados laboratoriais e métodos de imagem podem ser úteis. Marcadores moleculares também vêm sendo ativamente investigados e alguns, como BRAF, os genes GST e polimorfismos de p53, parecem promissores. Além disso, marcadores imunocitoquímicos e a medida da natureza fractal da cromatina podem aumentar a especificidade do diagnóstico anatomopatológico e ajudar a predizer o prognóstico. Existe uma necessidade imperiosa de elaborarmos diretrizes destinadas a selecionar os nódulos que merecem prosseguimento em sua avaliação, assim como novos métodos capazes de identificar lesões mais agressivas entre os geralmente indolentes tumores tiroidianos.

Expressão de sulfomucinas e de carboidratos de mucinas simples no esôfago de Barrett / Expression of sulphomucins and simple-mucin type carbohydrate in Barrett's esophagus

INTRODUÇÃO: A expressão de mucinas sulfatadas e de antígenos de carboidratos simples de mucinas tem sido relacionada com o risco de transformação maligna no trato gastrintestinal. OBJETIVOS: Avaliar a expressão de mucinas sulfatadas e dos antígenos Tn, sTn, T e sT no esôfago de Barrett (EB). MATERIAL E MÉTODO: Estudaram-se 50 biópsias de EB. As amostras foram processadas rotineiramente para exame histológico (hematoxilina e eosina [HE] e ácido periódico de Schiff [PAS]/azul de alcião). Cortes adicionais foram corados para detecção de mucinas sulfatadas (diamina férrica) e dos antígenos Tn, sTn, T e sT por imuno-histoquímica. O EB foi classificado quanto aos subtipos de metaplasia intestinal e sua extensão nas amostras. A expressão de Tn, sTn, T e sT no EB foi discriminada quanto à positividade em células caliciformes e colunares. RESULTADOS: Detectou-se metaplasia intestinal incompleta com secreção de sulfomucinas em 47 casos; em três não se identificou a lesão nos cortes realizados para a histoquímica. Observou-se metaplasia intestinal tipo III em 44 dos 47 casos analisados (93,6 por cento) e do tipo II isoladamente em três casos (6,4 por cento). Não se detectou metaplasia intestinal do tipo I. Tn expressou-se fortemente em células colunares em 94 por cento dos casos e foi focal/negativo nas caliciformes; sTn exibiu forte marcação nas células caliciformes em 88 por cento dos casos. Os demais marcadores foram negativos na maior parte dos casos (T negativo em 82 por cento e sT em 87,8 por cento). CONCLUSÕES: A expressão de sulfomucinas e de antígenos de carboidratos simples de mucinas foi homogênea no EB. A lesão caracterizou-se por metaplasia intestinal incompleta com extenso componente de tipo III e expressão de Tn e sTn. Esses dados sugerem que os marcadores testados não permitem discriminar lesões com diferentes potenciais de transformação maligna.

BACKGROUND: The expression of sulphomucins and simple-mucin type carbohydrate antigens has been used as marker of malignant transformation in the gastrointestinal tract. OBJECTIVES: To evaluate the expression of sulphomucins and simple-mucin type carbohydrate antigens (Tn, sTn T and sT) expression in Barrett's esophagus (BE) in order to identify potential lesions of increased risk to malignant transformation. METHODS: Biopsies of 50 cases of BE processed routinely were studied; diagnosis was performed in hematoxylin and eosin (HE) and periodic acid Schiff (PAS)/alcian blue stained sections. Additional sections were stained by high iron diamine for subtype intestinal metaplasia and by immunohistochemistry for Tn, sTn, T and sT antigens, whose expression was analyzed in the columnar and goblet cells of BE. RESULTS: BE was detected in only 47 cases stained by histochemistry and all of them had sulphomucin expression. Type III intestinal metaplasia was detected in 44 cases (93.6 percent); three had only type II, and type I was not observed. Tn antigen was expressed in columnar cells in 94 percent of the cases and sTn was expressed in goblet cells in 88 percent of them. T and sT were negative in 82 percent and in 87.8 percent of the cases, respectively. CONCLUSIONS: BE showed a homogeneous pattern of expression of sulphomucins and simple-mucin type carbohydrate antigens. BE was characterized as incomplete-type intestinal metaplasia with type III component together with Tn and sTn expression. According to these data, these markers are not useful to discriminate lesions with different potential of malignant transformation.

Mucin expression profile in Barrett's, dysplasia, adenocarcinoma sequence in the esophagus.

BACKGROUND: The molecular events that accompany the progression to adenocarcinoma (ADC) of the esophagus are poorly understood. Aberrant mucin receptor expression can contribute to increased cell growth and metastatic ability. AIM: The aim of this study was to establish a pattern for mucin (MUC) gene expression in the esophageal mucosa under normal and pathological conditions. SETTING: University Hospital Cancer Center Laboratory. Archived tissue samples studied in a retrospective fashion. MATERIALS AND METHODS: Tissue samples were obtained from the archives of patients with histological evidence of Barrett's esophagus (BE) progressing to ADC. Immunohistochemical analysis was performed using mouse monoclonal antibodies for MUC1, MUC2, MUC5AC, MUC6. Semiquantitative scoring of histological staining was performed using a linear scoring system: 0-staining absent; 1-staining in 0-25%; 2-staining in 25-50%; and 3-staining in 50-75% of the epithelium. The Binomial test was used to explore trends and differences in frequency of mucin expression along the pathological sequence. RESULTS: Only mild superficial staining of MUC1 was seen in normal squamous epithelium. MUC1 and MUC2 were uniformly expressed in all samples (7/7) of BE and dysplasia (P=0.008). MUC1 expression was upregulated (7/7) in progression to adenocarcinoma (P=0.008). The secretory mucins, MUC5AC and MUC6 showed a decrease in expression with progression from BE to dysplasia to ADC (P< 0.05). CONCLUSIONS: Downregulation of MUC5AC and MUC6 decreases mucosal protection against gastric acid. Increasing MUC1 expression is associated with progression from dysplasia to ADC. Upregulation of MUC2 reflects intestinal metaplasia in BE.