Timely topic: Premalignant lesions associated with adenocarcinoma of the upper gastrointestinal tract

The changing incidence of adenocarcinomas, particularly in the oesophagus and gastric cardia, has led to the rapid expansion of screening programmes aimed at detecting the precursor lesion of dysplasia before adenocarcinoma develops. The pathologist now has an important role in first diagnosing patients at risk for developing dysplasia, and then correctly classifying dysplasia when it occurs. Barrett's oesophagus has had different diagnostic criteria in previous years but is currently diagnosed by the presence of intestinal metaplasia of any length in the true oesophagus. Intestinal metaplasia confined only to the gastro-oesophageal junction or cardia is of uncertain significance but is probably common, with less risk of progressing to dysplasia or malignancy. In the stomach, patients with autoimmune atrophic gastritis and Helicobacter-associated multifocal atrophic gastritis have an increased risk of adenocarcinoma, but screening protocols are not well-developed compared with those used for Barrett's oesophagus. Dysplasia of glandular epithelium can be classified using well-described criteria. Low grade dysplasia is the most common type and regresses or remains stable in the majority of patients. High grade dysplasia is more ominous clinically, with a propensity to coexist with or progress to adenocarcinoma.

Cloning and gastrointestinal expression of rat hephaestin: relationship to other iron transport proteins

The membrane-bound ceruloplasmin homolog hephaestin plays a critical role in intestinal iron absorption. The aims of this study were to clone the rat hephaestin gene and to examine its expression in the gastrointestinal tract in relation to other genes encoding iron transport proteins. The rat hephaestin gene was isolated from intestinal mRNA and was found to encode a protein 96% identical to mouse hephaestin. Analysis by ribonuclease protection assay and Western blotting showed that hephaestin was expressed at high levels throughout the small intestine and colon. Immunofluorescence localized the hephaestin protein to the mature villus enterocytes with little or no expression in the crypts. Variations in iron status had a small but nonsignificant effect on hephaestin expression in the duodenum. The high sequence conservation between rat and mouse hephaestin is consistent with this protein playing a central role in intestinal iron absorption, although its precise function remains to be determined.

Myiasis gastrointestinal humana por Eristalis tenax

Son caracterizadas las myiasis registradas en Bariloche y establecidas las condiciones probables bajo las cuales se produjeron las infestaciones. Las larvas obtenidas a partir de heces de 2 pacientes fueron identificadas como Eristalis tenax (Diptera: Syrphidae) de acuerdo a las claves de Hartley (1961) y Organización Panamericana de la Salud (1962). Estos 2 casos de myiasis gastrointestinal humana constituyen los primeros registrados en Bariloche (Patagonia, Argentina) y sus características responden a las registradas para esta especie de Díptera en otras partes del mundo. La falta de control específico en el sistema domiciliario de suministro de agua ha sido la causa más probable de la infestación. Este registro extiende la distribución de E. tenax y de las myiasis gastrointestinales humanas en América del Sur hasta los 41º 03' S.

Expressão de transtirretina no sistema gastrointestinal do murganho

A transtirretina (TTR) é uma proteína plasmática constituída por quatro subunidades idênticas de aproximadamente 14KDa e de massa molecular de 55 KDa (Blake et al., 1978). A TTR é responsável pelo transporte de tiroxina (T4) (Andrea et al., 1980) e retinol (vitamina A), neste último tipo de transporte através da ligação à proteina de ligação ao retinol (RBP) (Kanai et al., 1968). É sintetizada principalmente pelo fígado e secretada para o sangue (Murakami et al., 1987) e também sintetizada pelas células epiteliais do plexo coróide e secretada para o líquido cefaloraquidiano (LCR) (Aleshire et al., 1983). Existem outros locais que expressam TTR mas em menor quantidade, nomeadamente: a retina do olho (Martone et al., 1988), o pâncreas (Kato et al., 1985), o saco vitelino visceral (Soprano et al., 1986) o intestino (Loughna et al., 1995); o estômago, coração, músculo e baço (Soprano et al., 1985). A TTR é uma proteína, do ponto de vista filogenético, extremamente conservada o que já de si é um indicador da sua importância biológica (Richardson, 2009) O objectivo deste trabalho foi avaliar a expressão de transtirretina ao longo do sistema gastrointestinal do murganho, nos seguintes órgãos esófago, estômago, duodeno, cólon e também bexiga, com cerca de 3 meses de idade. O segundo objectivo foi identificar as células responsáveis por essa expressão, nos órgãos em estudo. Foi possível verificar que apenas o estômago apresenta valores de expressão normalizada de TTR diferente de zero, expressão essa muito inferior à do fígado, tal como se esperava. Por imunohistoquímica/imunofluorescência foi possível determinar que as células que expressam TTR são pouco abundantes e estão presentes na região glandular do estômago do murganho e também do humano. Para além disto, verificou-se que a TTR co-localiza com somatostatina e que as células que sintetizam TTR correspondem às células D, responsáveis pela secreção de somatostatina

Low frequency of TERT promoter mutations in gastrointestinal stromal tumors (GISTs)

Somatic mutations in the promoter region of telomerase reverse transcriptase (TERT) gene, mainly at positions c.-124 and c.-146 bp, are frequent in several human cancers; yet its presence in gastrointestinal stromal tumor (GIST) has not been reported to date. Herein, we searched for the presence and clinicopathological association of TERT promoter mutations in genomic DNA from 130 bona fide GISTs. We found TERT promoter mutations in 3.8% (5/130) of GISTs. The c.-124C>T mutation was the most common event, present in 2.3% (3/130), and the c.-146C>T mutation in 1.5% (2/130) of GISTs. No significant association was observed between TERT promoter mutation and patient's clinicopathological features. The present study establishes the low frequency (4%) of TERT promoter mutations in GISTs. Further studies are required to confirm our findings and to elucidate the hypothetical biological and clinical impact of TERT promoter mutation in GIST pathogenesis.

Gastrointestinal translocation as a possible source of candidemia in an AIDS patient

Apart from cryptococcosis and histoplasmosis, which are mycoses contained by T cell-mediated mechanisms of host defense, fungemia is rarely found in AIDS patients. The frequency of fungemia due to Candida spp. has been reported to be as low as 1 %. We report a non-neutropenic AIDS patient who presented a candidemia which probably arose from her gastrointestinal tract.

A preliminary investigation on the gastrointestinal helminths of the Barbados green monkey, Cercopithecus aethiops sabaeus

Faecal samples were collected from fifty three freshly captured monkeys which were kept at the Barbados Primate Research Centre and Wildlife Reserve (BPRCWR). Examination of these samples for gastrointestinal helminths using the zinc sulphate floatation method revealed an overall infection rate of 88.7%.The parasites observed included Strongyloides (62.4%), Physaloptera (58.5%), Trichuris (52.8%), Hookworm (34.0%), Oesophagostomum (30.2%), Trichostrongylus (3.8%) and Ascaris (5.7%). No significant differences in overall prevalence were observed according to sex or age. Polyparasitism appeared to be common as it was observed in 92.5% of all monkeys examined. It is concluded that these monkeys could act as reservoirs of some of the parasites which can infect man.

A preliminary study of the prevalence of intestinal parasites in immunocompromised patients with and without gastrointestinal manifestations

The objective of the present study was to determine the prevalence of the intestinal parasites most commonly found in immunocompromised patients. A group of 111 individuals with acute lymphoid leukaemia (ALL), chronic myeloid leukaemia (CML), human immunodeficiency virus (HIV) and other immunocompromised conditions (principally haematological disorders) was selected. A battery of tests was performed on each individual to identify the presence of parasites (three stool specimens with saline solution and Lugol both directly and by concentration, culture and special staining). No significant differences were found among the frequencies of the different parasites with the several types of immunocompromised conditions. The overall frequencies of potentially pathogenic and opportunistic parasites were 32.4% (36/111) and 9% (10/111) respectively, the most frequently encountered among the latter being Cryptosporidium sp., Microsporidia spp. and Strongyloides stercoralis.

Recomendações para Análise Mutacional em Tumores do Estroma Gastrointestinal (GISTs). Grupo de Trabalho Português GIST - Proposta de Condeixa

Os autores apresentam as recomendações para a análise mutacional de GISTs, aprovadas por unanimidade por um grupo multidisciplinar em 20 de Julho de 2012. O estado mutacional de genes como o KIT e o PDGFRA permite identificar alvos terapêuticos para inibidores da tirosinacínase (ITKs) e, por isso, a boa prática clínica nas decisões bioterapêuticas de doentes com GISTs deve incluir a análise do estado mutacional. A análise mutacional da doença primária não é recomendada na rotina diagnóstica da generalidade dos GISTs; no entanto, pode ter valor prognóstico e ser útil na seleção de doentes, após ressecção completa de GIST primário e é considerada experimental na doença progressiva sob tratamento com ITKs. A análise mutacional deve considerar-se nos casos selecionados descritos neste texto e ser realizada em laboratórios em conformidade com padrões elevados de garantia de qualidade, atendendo ao seu elevado impacto sobre as decisões clínicas.

PATHOGENICITY OF Blastocystis sp. TO THE GASTROINTESTINAL TRACT OF MICE: RELATIONSHIP BETWEEN INOCULUM SIZE AND PERIOD OF INFECTION

The pathogenic potential of Blastocystis sp. in experimental models requires further investigation. In this work, the pathogenicity of this parasite in the gastrointestinal tract of male Swiss mice was evaluated according to the inoculum size and period of infection. Animals were infected intragastrically, with 100, 500, 1,000, 5,000 and 10,000 Blastocystis sp. vacuolar forms obtained from a mixture of eight human isolates cultured axenically in Jones' medium. After seven, 14, 21, 28 and 60 days of infection, the animals were sacrificed and fragments of the small intestine (duodenum), large intestine, and cecum were subjected to histopathological analysis. Blastocystis sp. triggered an inflammatory response in the different tissues analyzed, with a predominance of mononuclear cells. The parasite was found in the muscular layer of the cecum, showing its invasive character. Larger inocula triggered inflammatory processes earlier (seven days) than smaller ones (from 21 days). We conclude that, in the proposed model, the pathogenicity of Blastocystis sp. isolates that were studied is related to inoculum size and period of infection.

PREVALENCE, RISK FACTORS AND SYMPTOMS ASSOCIATED TO INTESTINAL PARASITE INFECTIONS AMONG PATIENTS WITH GASTROINTESTINAL DISORDERS IN NAHAVAND, WESTERN IRAN

We studied the prevalence of intestinal parasites (IPs), their risk factors and associated symptoms among patients with gastrointestinal disorders. A total of 1,301 participants aged 22 days-90 years were enrolled in this study. We used a structured questionnaire to obtain socio-demographic and stool examination to investigate intestinal parasite infections. Data analysis was performed using SPSS16. The overall prevalence of intestinal parasites (IPs) was 32.2% (419/1,301). Three hundred and fifty nine cases/1,301 (27.6%) were infected with a single parasite and 60/1,301 cases (4.6%) presented polyparasitism. The most common IP was Blastocystis sp. 350/1,301 (26.9%), followed by Entamoeba coli 38/1,301 (2.92%), Giardia lamblia 30/1,301 (2.3%) and Cryptosporidium spp. 17/1,301 (1.3%). Regarding the socio-demographic variables, educational status (p = 0.001), contact with domestic animals and soil (p = 0.02), age above 15 years (p = 0.001) and seasons (p = 0.001) were significantly associated to intestinal parasitic infections. Concerning clinical characteristics, the presence of IPs was significantly associated to diarrhea (OR = 1.57; CI 95% = 1.24-1.98; p < 0.001) and dysentery (OR = 1.94; CI 95% = 1.03-3.66; p < 0.04). Our findings suggest that IPs are one of the main causal agents of gastrointestinal disorders. Improving the knowledge on local risk factors such as poverty, low level of education, poor sanitation, contact with soil and contact with domestic animal is warranted.

Angiodisplasia Gastrointestinal. Terapêutica Estroprogestativa

A propósito de um caso clínico, os autores fazem uma revisão da literatura sobre angiodisplasia gastrointestinal como causa comum de hemorragia oculta no idoso, sua associação com estenose aórtica e a eficácia da terapêutica estroprogestativa na sua prevenção e tratamento.

Avaliação do efeito da simulação in vitro da digestão gastrointestinal nas propriedades antioxidantes das infusões de cidreira e tília

Dissertação para obtenção do Grau de Mestre em Tecnologia e Segurança Alimentar

Lesões do trato gastrointestinal na síndrome da imunodeficiência adquirida: [title]estudo de 45 necrópsias consecutivas

Com objetivo de estudar afrequência e etiologia das lesões do tubo digestivo na Síndrome da Imunodeficiência Adquirida (AIDS), foram analisadas retrospectivamente 45 necrópsias consecutivas de pacientes adultos portadores do vírus da AIDS. Lesões macroscópicas e cortes histológicos de amostras da boca à região anal foram estudados, sendo as lâminas coradas por HE, métodos histoquímicos ou imunohistoquímicos. Trinta e sete (82,3 %)pacientes apresentaram lesões no tubo digestivo. O local mais freqüente de lesões foi a boca (73,3%), seguido do cólon (55,5%). Lesões múltiplas foram identificadas em 17 (37,7%) casos. O diagnóstico mais prevalente foi infecção pelo citomegalovírus (35,7%) identificado predominantemente no cólon. Candidíasefoi mais freqüente na boca (26,6%) e infecção herpética no esôfago (8,8%). Verificou-se leucoplasiapilosa oral em 16 (35,5%) eneoplasias emsete (15,5%). Asneoplasias incluíram quatro sarcomas de Kaposi, dois Carcinomas intramucosos anais e um linfoma gástrico. Os dados do presente estudo confirmam a importância do trato gastrointestinal como sede de alterações patológicas relacionadas à AIDS.