RESUMO
Studies have reported the occurrence of gastrointestinal (GI) symptoms, primarily diarrhea, in COVID-19. However, the pathobiology regarding COVID-19 in the GI tract remains limited. This work aimed to evaluate SARS-CoV-2 Spike protein interaction with gut lumen in different experimental approaches. Here, we present a novel experimental model with the inoculation of viral protein in the murine jejunal lumen, in vitro approach with human enterocytes, and molecular docking analysis. Spike protein led to increased intestinal fluid accompanied by Cl- secretion, followed by intestinal edema, leukocyte infiltration, reduced glutathione levels, and increased cytokine levels [interleukin (IL)-6, tumor necrosis factor-α, IL-1ß, IL-10], indicating inflammation. Additionally, the viral epitope caused disruption in the mucosal histoarchitecture with impairment in Paneth and goblet cells, including decreased lysozyme and mucin, respectively. Upregulation of toll-like receptor 2 and toll-like receptor 4 gene expression suggested potential activation of local innate immunity. Moreover, this experimental model exhibited reduced contractile responses in jejunal smooth muscle. In barrier function, there was a decrease in transepithelial electrical resistance and alterations in the expression of tight junction proteins in the murine jejunal epithelium. Additionally, paracellular intestinal permeability increased in human enterocytes. Finally, in silico data revealed that the Spike protein interacts with cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride conductance (CaCC), inferring its role in the secretory effect. Taken together, all the events observed point to gut impairment, affecting the mucosal barrier to the innermost layers, establishing a successful experimental model for studying COVID-19 in the GI context.
Assuntos
COVID-19 , Mucosa Intestinal , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Glicoproteína da Espícula de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , SARS-CoV-2/fisiologia , SARS-CoV-2/imunologia , Humanos , Camundongos , COVID-19/imunologia , COVID-19/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/imunologia , Jejuno/imunologia , Jejuno/metabolismo , Jejuno/patologia , Jejuno/virologia , Simulação de Acoplamento Molecular , Enterócitos/metabolismo , Enterócitos/virologia , Imunidade Inata , Citocinas/metabolismo , Modelos Animais de Doenças , Masculino , Relevância ClínicaRESUMO
AIMS: The aim of our study was to study the pathological mechanisms induced by the rheumatoid arthritis (RA) on the Enteric Nervous System (ENS). MAIN METHODS: We evaluated the effect of the chronic arthritis and its treatment with 50â¯mg/kg quercetin alone (AQ) and combined with 17.5â¯mg/kg ibuprofen (AIQ) for 60 days on neurons, glial cells and intestinal wall. Other groups were used: control (C), arthritic (A) and arthritic treated with 17.5â¯mg/kg ibuprofen (AI). After 60 days, the jejunum was removed and processed for immunohistochemical techniques. Immunostainings were performed for HuC/D and S100 (myenteric and submucosal plexuses), and GFAP (only myenteric plexus), while immunolabeling for CD45 and CD20 lymphocytes was performed using cryosections. Western blot was performed for GDNF, S100 and GFAP. KEY FINDINGS: A group yielded a remarkable density decrease of the neurons and glial cells with morphometric changes in the myenteric and submucosal plexuses, reduction of the GDNF expression and GFAP-related parameters (GFAP expression, occupancy area and GFAP-expressing glial cells) and intestinal inflammation and atrophy of the mucosa and intestinal wall. AQ group substantially reversed most of these effects, except for intestinal atrophy of the jejunum. The AI and AIQ groups displayed lower beneficial results than AQ for parameters related to the neurons and glial cells, although AIQ did not prevent the inflammation of the mucosa. SIGNIFICANCE: The severe chronic rheumatoid arthritis induced severe effects on ENS and mucosa, and quercetin treatment continues to be an important antioxidant supplement preventing the progression of the RA severity.
Assuntos
Anti-Inflamatórios/farmacologia , Artrite Experimental/complicações , Artrite Reumatoide/complicações , Inflamação/tratamento farmacológico , Jejuno/efeitos dos fármacos , Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Quercetina/farmacologia , Animais , Antioxidantes/farmacologia , Artrite Experimental/induzido quimicamente , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/patologia , Inflamação/etiologia , Inflamação/patologia , Jejuno/imunologia , Jejuno/patologia , Masculino , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/patologia , Neuroproteção/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
We investigated the inflammatory effect of a pellet-diet with high glycemic index and load (HGLI) on the histological organization of adipocytes, intestinal epithelium, and fat in liver and pancreas in adult male Wistar rats. Two groups (n=10) received for 17 weeks: (1) HGLI diet or (2) Standard diet (Labina®). Histological analyses of adipose tissue, jejunum, liver, and pancreas were performed. Stereology analysis, visceral adiposity index, gene expression, and immunohistochemistry of tumor necrosis factor-α (TNF-α) in visceral adipose tissue and plasma TNF-α were also assessed. The HGLI diet-induced hypertrophy of adipocytes with adipocyte volume density equal to 97.0%, cross-sectional area of adipocytes equivalent to 1387 µm² and a total volume of adipocytes of 6.97 cm³ an elevation of 8%, 25%, and 58%, respectively. Furthermore, the HGLI diet increased liver and pancreatic fat deposition, altered and inflamed the intestinal epithelia, and increased TNF-α gene expression (P=0.014) with a positive immunostaining in visceral adipose tissue and high plasma TNF-α in comparison with standard diet. The results suggest that this diet was able to generate changes commonly caused to solid diets with high fat or fructose-rich beverages. To the best of our knowledge, this is the first report in the literature concerning the properties of low-cost, sucrose-rich pellet-diet presenting high glycemic index and high glycemic load efficient on the development of obesity complications in Wistar rats that were subjected to diet-induced obesity. Therefore, the HGLI pellet-diet may be considered an effective tool to be used by the scientific community in experimental research.
Assuntos
Adipócitos/patologia , Dieta da Carga de Carboidratos/efeitos adversos , Mucosa Intestinal/fisiopatologia , Jejuno/fisiopatologia , Obesidade/fisiopatologia , Sacarose/efeitos adversos , Adipócitos/imunologia , Animais , Expressão Gênica , Índice Glicêmico , Imuno-Histoquímica , Inflamação , Mucosa Intestinal/imunologia , Gordura Intra-Abdominal/imunologia , Gordura Intra-Abdominal/patologia , Jejuno/imunologia , Fígado/imunologia , Fígado/fisiopatologia , Masculino , Obesidade/etiologia , Obesidade/genética , Obesidade/imunologia , Pâncreas/imunologia , Pâncreas/fisiopatologia , Ratos , Ratos Wistar , Sacarose/administração & dosagem , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
The aim of this study was to evaluate the effect of a probiotic/lactose inoculum on haematological and immunological parameters and renal and hepatic biochemical profiles before and during a Salmonella Dublin DSPV 595T challenge in young calves. Twenty eight calves, divided into a control and probiotic group were used. The probiotic group was supplemented with 100 g lactose/calf/d and 1010 cfu/calf/d of each strain of a probiotic inoculum composed of Lactobacillus casei DSPV318T, Lactobacillus salivarius DSPV315T and Pediococcus acidilactici DSPV006T throughout the experiment. The pathogen was administered on day 11 of the experiment, at an oral dose of 109 cfu/animal (LD50). Aspartate aminotransferase (AST), gamma glutamyl transpeptidase (GGT), urea, red blood cells, haemoglobin, haematocrit, mean cell haemoglobin (MCH), mean corpuscular volume, mean corpuscular haemoglobin concentration (MCHC), white blood cells, lymphocytes, neutrophils, band neutrophils, monocytes, eosinophils, basophils and the neutrophils/lymphocytes ratio were measured on days 1, 10, 20 and 27 of the experiment. In addition, animals were necropsied to evaluate immunoglobulin A (IgA) production in the jejunal mucosa. The most significant differences caused by the administration of the inoculum/lactose were found during the acute phase of Salmonella challenge (9 days after challenge), when a difference between groups in neutrophils/lymphocytes ratio were detected. These results suggest that the probiotic/lactose inoculum administration increases the calf's ability to respond to the disease increasing the systemic immune response specific. No differences were found in haemoglobin, haematocrit, MCH, MCHC, AST, urea, GGT, band neutrophils, eosinophils, monocytes and IgA in the jejunum between the two groups of calves under the experimental conditions of this study. Further studies must be conducted to evaluate different probiotic/pathogens doses and different sampling times, to achieve a greater understanding of the effects of this inoculum on intestinal infections in young calves and of its mechanism of action.
Assuntos
Probióticos/uso terapêutico , Salmonelose Animal/terapia , Ração Animal , Animais , Análise Química do Sangue/veterinária , Bovinos , Contagem de Eritrócitos/veterinária , Hematócrito/veterinária , Testes Hematológicos/veterinária , Hemodinâmica/efeitos dos fármacos , Hemoglobinas/metabolismo , Imunoglobulina A/análise , Jejuno/imunologia , Lacticaseibacillus casei , Ligilactobacillus salivarius , Lactose/administração & dosagem , Contagem de Leucócitos/veterinária , Pediococcus acidilactici , Salmonelose Animal/sangue , Salmonella typhimurium , Análise de SobrevidaRESUMO
Using flow cytometry, we evaluated the frequencies of CD4(+) and CD8(+) T cells and Foxp3(+) regulatory T cells (Tregs) in mononuclear cells in the jejunum, colon, and cervical and mesenteric lymph nodes of dogs naturally infected with Leishmania infantum and in uninfected controls. All infected dogs showed chronic lymphadenitis and enteritis. Despite persistent parasite loads, no erosion or ulcers were evident in the epithelial mucosa. The colon harbored more parasites than the jejunum. Frequencies of total CD4(+), total Foxp3, and CD4(+) Foxp3(+) cells were higher in the jejunum than in the colon. Despite negative enzyme-linked immunosorbent assay (ELISA) serum results for cytokines, levels of interleukin-10 (IL-10), gamma interferon (IFN-γ), transforming growth factor beta (TGF-ß), and tumor necrosis factor alpha (TNF-α) were higher in the jejunum than in the colon for infected dogs. However, IL-4 levels were higher in the colon than in the jejunum for infected dogs. There was no observed correlation between clinical signs and histopathological changes or immunological and parasitological findings in the gastrointestinal tract (GIT) of canines with visceral leishmaniasis. However, distinct segments of the GIT presented different immunological and parasitological responses. The jejunum showed a lower parasite load, with increased frequencies and expression of CD4, Foxp3, and CD8 receptors and IL-10, TGF-ß, IFN-γ, and TNF-α cytokines. The colon showed a higher parasite load, with increasing expression of IL-4. Leishmania infantum infection increased expression of CD4, Foxp3, IL-10, TGF-ß, IFN-γ, and TNF-α and reduced CD8 and IL-4 expression in both the jejunum and the colon.
Assuntos
Colo do Útero/imunologia , Colo/imunologia , Jejuno/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Linfonodos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/microbiologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/microbiologia , Colo do Útero/microbiologia , Colo/microbiologia , Doenças do Cão/imunologia , Doenças do Cão/microbiologia , Cães , Enterite/imunologia , Enterite/microbiologia , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Feminino , Fatores de Transcrição Forkhead/imunologia , Interferon gama/imunologia , Interleucina-10/imunologia , Interleucina-4/imunologia , Jejuno/microbiologia , Leishmaniose Visceral/microbiologia , Linfonodos/microbiologia , Linfadenite/imunologia , Linfadenite/microbiologia , Masculino , Mucosa/imunologia , Mucosa/microbiologia , Carga Parasitária , Fator de Crescimento Transformador beta/imunologia , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Intestinal mucositis is an important toxic side effect of 5-fluorouracil (5-FU) treatment. Saccharomyces boulardii is known to protect from intestinal injury via an effect on the gastrointestinal microbiota. The objective of the present study was to evaluate the effect of S. boulardii on intestinal mucositis induced by 5-FU in a murine model. Mice were divided into saline, saline (control)+5-FU or 5-FU+S. boulardii (16 × 109 colony-forming units/kg) treatment groups, and the jejunum and ileum were removed after killing of mice for the evaluation of histopathology, myeloperoxidase (MPO) activity, and non-protein sulfhydryl group (mainly reduced glutathione; GSH), nitrite and cytokine concentrations. To determine gastric emptying, phenol red was administered orally, mice were killed 20 min after administration, and the absorbance of samples collected from the mice was measured by spectrophotometry. Intestinal permeability was measured by the urinary excretion rate of lactulose and mannitol following oral administration. S. boulardii significantly reversed the histopathological changes in intestinal mucositis induced by 5-FU and reduced the inflammatory parameters: neutrophil infiltration (control 1·73 (SEM 0·37) ultrastructural MPO (UMPO)/mg, 5-FU 7·37 (SEM 1·77) UMPO/mg and 5-FU+S. boulardii 4·15 (SEM 0·73) UMPO/mg); nitrite concentration (control 37·00 (SEM 2·39) µm, 5-FU 59·04 (SEM 11·41) µm and 5-FU+S. boulardii 37·90 (SEM 5·78) µm); GSH concentration (control 477·60 (SEM 25·25) µg/mg, 5-FU 270·90 (SEM 38·50) µg/mg and 5-FU+S. boulardii 514·00 (SEM 38·64) µg/mg). Treatment with S. Boulardii significantly reduced the concentrations of TNF-α and IL-1ß by 48·92 and 32·21 % in the jejunum and 38·92 and 61·79 % in the ileum. In addition, S. boulardii decreased the concentrations of chemokine (C-X-C motif) ligand 1 by 5-fold in the jejunum and 3-fold in the ileum. Interestingly, S. boulardii reduced the delay in gastric emptying (control 25·21 (SEM 2·55) %, 5-FU 54·91 (SEM 3·43) % and 5-FU+S. boulardii 31·38 (SEM 2·80) %) and induced the recovery of intestinal permeability (lactulose:mannitol ratio: control 0·52 (SEM 0·03), 5-FU 1·38 (SEM 0·24) and 5-FU+S. boulardii 0·62 (SEM 0·03)). In conclusion, S. boulardii reduces the inflammation and dysfunction of the gastrointestinal tract in intestinal mucositis induced by 5-FU.
Assuntos
Modelos Animais de Doenças , Íleo/imunologia , Mucosa Intestinal/imunologia , Jejuno/imunologia , Mucosite/dietoterapia , Prebióticos , Saccharomyces/imunologia , Animais , Anti-Inflamatórios não Esteroides/imunologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Citocinas/metabolismo , Regulação para Baixo , Fezes/química , Esvaziamento Gástrico , Fármacos Gastrointestinais/imunologia , Fármacos Gastrointestinais/uso terapêutico , Glutationa/metabolismo , Íleo/metabolismo , Íleo/microbiologia , Íleo/patologia , Absorção Intestinal , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Jejuno/metabolismo , Jejuno/microbiologia , Jejuno/patologia , Masculino , Camundongos , Mucosite/imunologia , Mucosite/metabolismo , Mucosite/microbiologia , Infiltração de Neutrófilos , Óxido Nítrico/metabolismo , Peroxidase/metabolismo , Distribuição Aleatória , Saccharomyces/crescimento & desenvolvimentoRESUMO
BACKGROUND: Infection with parasite protozoa is a long-term health issue in tropical and subtropical regions throughout the world. The Toll-like receptor (TLR) signaling pathway is one of the first-responding defense systems against Leishmania. The aim of this study was to investigate the expression of TLR2 and TLR9 in jejunum and colon and its correlation with CD11c, CD11b, and CD14 receptors used as markers for dendritic cells and macrophages. METHODS: Twenty four dogs infected with Leishmania infantum were used in this study. Cytometry was carried out in lamina propria cells from jejunum and colon using markers for TLR2, TLR9, CD11b, CD11c and CD14. RESULTS: Cellular inflammatory exudate was diffuse in the mucosa and submucosa, predominately comprising mononuclear cells: plasma cells, macrophages, and lymphocytes. Despite the parasite load, microscopy showed no erosion was evident in the epithelial mucosa layers. The colon harbored more parasites than the jejunum. Flow cytometry revealed higher frequency of TLR2+ and CD11c+ dendritic cells in the colon than in the jejunum. Conversely, TLR9-expressing cells were more frequent in jejunum. Moreover, frequency of macrophages (CD11b+ and CD14+) expressing simultaneity TLR9 were lower in the colon than in jejunum, while CD11c+ cells predominated in the colon. Despite of the negative ELISA serum results, IL-10 and TNF-α were higher in jejunum than colon of infected animals. However, IL-4 was higher in colon than jejunum of infected animals. A higher expression these cytokines were demonstrated in infected dogs compared to uninfected dogs. CONCLUSIONS: There was no correlation between clinical signs and pathological changes and immunological and parasitological findings in the gastrointestinal tract in canine visceral leishmaniasis. However, jejunum showed a lower parasite load with increased frequency and expression of CD11b, TLR9, CD14/CD11b/TLR9 receptors and IL-10 and TNF-α cytokines. Conversely, the colon showed a higher parasite load along with increased frequency and expression of TLR2, CD11c receptors, and IL-4 cytokine. Thus, Leishmania infantum is able to interfere in jejunum increased expression of TLR2, TLR9, CD11b, CD14, CD14/CD11b/TLR9 receptors, IL-10, and TNF-α; and in colon increased expression of CD11c, TLR2, TLR9, CD11b, CD14 e, CD14/CD11b/TLR9 receptors, IL-10, and TNF-α.
Assuntos
Colo/metabolismo , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Jejuno/metabolismo , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Receptor 2 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo , Animais , Antígenos CD/metabolismo , Brasil , Colo/imunologia , Colo/parasitologia , Colo/patologia , Citocinas/metabolismo , Doenças do Cão/metabolismo , Doenças do Cão/patologia , Cães , Fluorescência , Jejuno/imunologia , Jejuno/parasitologia , Jejuno/patologia , Leishmania infantum/fisiologia , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/patologia , Células Mieloides/metabolismo , ParasitosRESUMO
Food enteropathies involve uncontrolled or hypersensitivity reactions to ingested nutrients and may result in IgE and T-helper type 2 (Th2) responses as in food allergy. However, the precise role of B cells in the development of food enteropathies remains uncertain. In this work, we used B cell-deficient mice (B KO) and a model of peanut sensitization to examine the involvement of B lymphocytes in the pathogenesis of food allergy. Results showed that priming of wild-type (WT) mice with peanut proteins induced specific IgG1 and IgE responses in serum, with edema, tissue destruction, epithelial exulceration and inflammatory infiltrate in the gut of sensitized and challenged (S + Peanut) WT animals. In contrast, there was no sera immunoglobulin detection and absence of tissue destruction in the gut of B KO mice, which presented moderate inflammatory infiltrate and villous enlargement after peanut challenge. These animals presented marked decrease in IL-4 and TNF-alpha and high levels of IL-10, TGF-beta, IL-12p40 and IFN-gamma mRNA in the gut. Moreover, the expression of CCL5, CCL11 and CXCL1 was reduced in the gut of B KO mice, in contrast to elevated messages of CCL2 or similar detection of Th1-related chemokines in S + Peanut WT mice. Finally, we provided evidence that B cells are necessary to the development of food-related enteropathies and induction of gut inflammation during allergic reactions to food.
Assuntos
Linfócitos B/imunologia , Enterite/imunologia , Hipersensibilidade a Amendoim/imunologia , Alérgenos/imunologia , Animais , Arachis/imunologia , Quimiocinas/metabolismo , Citocinas/metabolismo , Enterite/patologia , Imunoglobulinas/biossíntese , Jejuno/imunologia , Jejuno/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hipersensibilidade a Amendoim/patologia , Proteínas de Vegetais Comestíveis/imunologia , Células Th2/imunologiaRESUMO
The neurotrophin, glial-derived neurotrophic factor (GDNF), is essential for the development of the enteric nervous system (ENS) in both the embryo and neonate and may be important for maintenance and plasticity of ENS. The tapeworm, Hymenolepis diminuta, altered the number of cells containing GNDF in the host's jejunum and ileum. Numbers and locations of GDNF-containing cells were determined by applying monoclonal anti-GDNF antibody to intestinal segments collected from infected and uninfected age-matched rats during the initial 34 days post-infection (dpi). Most cells staining positive for GDNF were present in the lamina propria of the jejunum and ileum from both infected and uninfected rats. The co-localization of staining by the antibodies, anti-GDNF and anti-ED2 (a nuclear specific antibody for resident macrophages) indicated that at least 74% of the cells staining for GDNF were macrophages. Mast cells did not stain with the anti-GDNF antibody. The increased number of GDNF+ cells in the infected rat intestine suggests that this neurotrophin may play a role in the neural and mucosal responses to lumenal tapeworm infection.
Assuntos
Infecções por Cestoides/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/análise , Hymenolepis diminuta , Intestino Delgado/metabolismo , Animais , Biomarcadores/análise , Contagem de Células , Infecções por Cestoides/imunologia , Íleo/química , Íleo/imunologia , Íleo/metabolismo , Imuno-Histoquímica , Intestino Delgado/química , Intestino Delgado/imunologia , Jejuno/química , Jejuno/imunologia , Jejuno/metabolismo , Macrófagos/química , Macrófagos/metabolismo , Masculino , Mastócitos/química , Mastócitos/metabolismo , Modelos Animais , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVES: To assess the efficiency of determining IgA and IgG antigliadin antibodies (IgA- and IgG-AGA, respectively), antitransglutaminase (TgA), and anti-endomysial antibodies (AEA) in human umbilical cord (CO) and monkey esophagus for diagnosis of celiac disease; to determine the correlation between serological markers and celiac disease. PATIENTS AND METHODS: A total of 400 patients were divided in 3 groups: group 1 with 37 patients with celiac disease, group 2 with 208 patients with no enteropathies, and group 3 with 155 patients with other enteropathies. IgA-AGA, IgG-AGA, and TgA were assessed using enzyme-linked immunosorbent assay, whereas AEA was evaluated by indirect immunofluorescence. RESULTS: Sensitivity and specificity of IgA-AGA were 81.1% and 95.2%, of IgG-AGA 89.2% and 95.2%, of TgA 83.9% and 96.8%, of AEA-CO 87.9% and 100%, and of AEA of monkey esophagus 88.6% and 100%, respectively. Positive predictive values were 75.0%, 76.7%, 83.9%, and 100%. Negative predictive values were 96.6%, 98.0%, 96.8%, and 97.7% for IgA-AGA, IgG-AGA, TgA, and AEA, respectively. Multivariate analysis showed a strong association between AEA-CO and celiac disease and a good correlation with other markers (TgA, IgA-AGA, and IgG-AGA). CONCLUSIONS: TgA has been recommended for screening patients with celiac disease. Considering the similar sensitivity and specificity of IgA-AGA and TgA and their correlations in the multivariate analysis, both are applicable for this purpose. However, because TgA tests are highly costly and celiac disease is associated with IgA deficiency, the determination of IgA-AGA and IgG-AGA, followed by AEA-CO, is suitable for screening in developing countries, provided a cutoff point for these examinations is established. The results of antiendomysial antibodies in umbilical cord overlapped those in monkey esophagus. Therefore, umbilical cord should be used as a substrate instead of specimens from endangered species.