RESUMO
The findings of functional endoscopy (upper esophageal sphincter insufficiency, cardia insufficiency, esophagitis, gastric heterotopia, axial sliding hernia, and visible aerosols) can be traced back to pharyngeal acid exposure by oropharyngeal pH measurement. Significantly increased pharyngeal acid loads are seen in gastric heterotopy and axial sliding hernia. For all measured statistics, the pharyngeal acid load is in the pathological or even very pathological range. The value of functional endoscopy in the context of laryngopharyngeal reflux diagnosis is clearly documented. The findings "heterotopic gastric mucosa" and "axial sliding hernia" may cause marked airway symptoms and a pathogenetic relationship with otorhinolaryngologic reflux-associated symptoms must be postulated for these entities.
Assuntos
Esofagite Péptica , Esofagoscopia , Refluxo Laringofaríngeo , Faringe/patologia , Esofagite Péptica/complicações , Esofagite Péptica/fisiopatologia , Humanos , Refluxo Laringofaríngeo/complicações , Refluxo Laringofaríngeo/fisiopatologia , ManometriaRESUMO
Classic gastroenterological diagnostic tools are proving increasingly insufficient for analyzing the complex causal relationship between extra-esophageal symptoms and presumed pathological reflux activity. Some new methodological approaches, such as functional endoscopy (videopanendoscopy, VPE), are considered to be helpful. However, there are currently no data objectively verifying the usefulness of this method. In a pilot study, a good correlation between the reflux symptom index (RSI) and endoscopic findings was shown. Impedance-pH measurement is considered to be the "gold standard" in esophageal reflux disease diagnostics. Therefore, the relationship between endoscopic findings and the results of impedance-pH monitoring are now studied in patients with extra-esophageal reflux symptoms. The investigation demonstrates that the pathological findings of VPE correlate well with impedance-pH measurements in terms of the parameters "number of reflux episodes", "fraction time", and "DeMeester score".
Assuntos
Monitoramento do pH Esofágico , Refluxo Gastroesofágico , Impedância Elétrica , Endoscopia , Refluxo Gastroesofágico/diagnóstico , Humanos , Concentração de Íons de Hidrogênio , Projetos PilotoRESUMO
Classic gastroenterological diagnostic tools have proven to be insufficient in identifying the causal relationship between extra-esophageal symptoms and presumed pathological reflux activity. Some new methodological approaches, such as functional endoscopy (video panendoscopy, VPE), are considered to be helpful. However, there are currently no data objectively verifying the success of this method. In a previous study, we found a good correlation between the reflux symptom index (RSI) according to Belafsky and endoscopic findings. Impedance-pH measurement is considered to be the gold standard in esophageal reflux disease diagnostics. Therefore, the relationship between endoscopic findings and the results of impedance-pH monitoring is now studied in patients with extra-esophageal reflux symptoms. The pathological findings of the VPE correlate with impedance-pH measurements regarding the parameters "number of reflux episodes," "fraction time," and "DeMeester score."
Assuntos
Esofagoscopia/métodos , Determinação da Acidez Gástrica , Refluxo Gastroesofágico/diagnóstico por imagem , Gravação em Vídeo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Laringite/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , SoftwareRESUMO
Food allergies are believed to be on the rise, and currently, management relies on the avoidance of the food. Hen's egg allergy is after cow's milk allergy the most common food allergy; eggs are used in many food products and thus difficult to avoid. A technological process using a combination of enzymatic hydrolysis and heat treatment was designed to produce modified hen's egg with reduced allergenic potential. Biochemical (SDS-PAGE, Size exclusion chromatography and LC-MS/MS) and immunological (ELISA, immunoblot, RBL-assays, animal model) analysis showed a clear decrease in intact proteins as well as a strong decrease of allergenicity. In a clinical study, 22 of the 24 patients with a confirmed egg allergy who underwent a double-blind food challenge with the hydrolysed egg remained completely free of symptoms. Hydrolysed egg products may be beneficial as low-allergenic foods for egg-allergic patients to extent their diet.
Assuntos
Alérgenos/imunologia , Hipersensibilidade a Ovo/imunologia , Proteínas do Ovo/efeitos adversos , Ovos/efeitos adversos , Tolerância Imunológica , Animais , Especificidade de Anticorpos/imunologia , Galinhas , Pré-Escolar , Modelos Animais de Doenças , Proteínas do Ovo/química , Feminino , Humanos , Hidrólise , Imunoglobulina E/imunologia , Lactente , Masculino , Muramidase/química , RatosRESUMO
To test the hypothesis of a heritable base of ectopic ureters (EU) in Entlebucher Mountain Dogs (EMD) and to elucidate associated risk factors and mode of inheritance of the disease, 565 EMD were clinically investigated and population genetic analyses performed. Based on the location of the most caudal termination of the ureteral openings, 552 EMD were classified into three phenotype groups trigone, intravesically and extravesically ectopic based on results of abdominal sonography, urethra-cystoscopy and/or contrast-enhanced computed tomography. One-third (32.9%) of the phenotyped animals had normal terminations of both ureters in the bladder trigone, 47.3% had at least one intravesicular ectopic termination and 19.8% had at least one extravesicular ectopic termination. Multivariate mixed logistic regression revealed gender as a risk factor associated with EU as males were more often affected than females. Complex segregation analysis indicated a hereditary basis for EU in EMD and the involvement of a major gene in the occurrence of the extravesicular EU phenotype.
Assuntos
Doenças do Cão/genética , Cães/anormalidades , Cães/genética , Ureter/anormalidades , Animais , Cistoscopia , Doenças do Cão/diagnóstico por imagem , Feminino , Masculino , Fenótipo , Fatores Sexuais , Tomografia Computadorizada por Raios X , Ureter/diagnóstico por imagemRESUMO
BACKGROUND: Extraesophageal reflux exists as shown by scientific data. The underlying pathophysiology is not yet exactly known. Functional endoscopy seems to be a promising new diagnostic instrument. This study determined the relationship between functional endoscopy and Belafsky's reflux symptom index (RSI). METHODS: In this study 71 patients were prospectively included and underwent a functional endoscopic examination followed by 6 months of proton pump inhibitor (PPI) therapy. Symptoms were scored using Belafsky's RSI after endoscopic examination (before treatment) and after 3 and 6 months of PPI therapy. RESULTS: After 3 and 6 months of PPI-therapy significant decreases in the RSI were found. The functional endoscopy characteristics which were expected to remain constant were controlled after 6 months and found to be nearly 100 % reproducible. Patients profit from PPI- therapy when reflux is detected by endoscopy even when RSI was initally normal. Functional endoscopy seems to be a useful instrument to detect extraesophageal reflux.
Assuntos
Esofagoscopia/métodos , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/tratamento farmacológico , Refluxo Laringofaríngeo/diagnóstico , Refluxo Laringofaríngeo/tratamento farmacológico , Laringoscopia/métodos , Inibidores da Bomba de Prótons/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Refluxo Gastroesofágico/complicações , Humanos , Refluxo Laringofaríngeo/etiologia , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica/efeitos dos fármacos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Association between chronic airway diseases (CAD) and gastroesophageal reflux disease (GERD) is well described, but causality has not yet been conclusively established. This study evaluates the therapeutic significance of laparoscopic Thal fundoplication in children with CAD and diagnosed GERD. METHODS: We performed a retrospective analysis of 182 neurologically nonimpaired children, all with medically refractory CAD and GERD undergoing laparoscopic Thal fundoplication. The clinical response, ability to wean oral and inhaled medication and satisfaction with postoperative results were evaluated. RESULTS: Main symptoms disappeared completely in 68.7% of patients and were markedly improved in a further 22% of patients following surgery. Complete discontinuation of medication was achieved in 70.1-96.4% of cases and reduced in a further 1.8-23.5%. One intraoperative complication occurred (gastric perforation), however no conversion to laparotomy was necessary. Postoperative Dumping Syndrome occurred in 1% of cases and was managed dietetically. Prolonged postoperative dysphagia occurred in 4.3% of patients, but disappeared within 8 weeks in all but one case. CONCLUSIONS: Our study suggests that Thal fundoplication in neurologically nonimpaired children with CAD and documented GERD is effective and safe. Children unresponsive to preoperative medical management showed significant improvement in airway symptoms together with a marked reduction in the need for medication. We conclude that laparoscopic Thal fundoplication represents a significant treatment worthy of consideration in this group of patients.
Assuntos
Fundoplicatura/métodos , Refluxo Gastroesofágico/cirurgia , Laparoscopia/métodos , Doenças Respiratórias/complicações , Criança , Pré-Escolar , Doença Crônica , Transtornos de Deglutição/etiologia , Feminino , Seguimentos , Refluxo Gastroesofágico/complicações , Humanos , Lactente , Masculino , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
A novel strategy to prevent an allergic immune response is presented. We tested the idea that a potent allergen such as cow's milk Beta lactoglobuline (ßLG) can be rendered tolerogenic by covalent linkage to isologous gammaglobuline. We found that, under certain conditions, a single intravenous dose (of 2 mg) of ßLG conjugated to rat gammaglobuline prevent both IgE and IgG antibodies to ßLG. This was allergen specific. It appears to be also effective in sensitized animals. In addition, it prevents serotonine release by rat mastocytes both in vivo and in vitro. We suggest that this approach could provide a novel strategy to specifically prevent allergy.
RESUMO
The calcium sensitizing effects of the cardiotonic agent pimobendan on force production were investigated on chemically skinned human papillary muscle fibres. The papillary muscles were obtained from patients undergoing mitral valve replacement operations. Tension was produced by different free calcium concentrations and 100 mumol/l of pimobendan shifted the pCa-tension relationship significantly to the left. The effects of pimobendan were concentration dependent (10-300 mumol/l) but additionally also correlated with the state of left ventricular performance of the patients. Skinned papillary muscle fibres obtained from patients with reduced ventricular performance were more sensitive to calcium as well as pimobendan compared with fibres from patients with normal left ventricular performance. No differences in response to pimobendan were observed between fibres from NYHA II and NYHA III heart failure patients.
Assuntos
Cálcio/farmacologia , Cardiotônicos/farmacologia , Piridazinas/farmacologia , Humanos , Técnicas In Vitro , Contração Miocárdica/efeitos dos fármacos , Músculos Papilares/efeitos dos fármacos , Músculos Papilares/ultraestruturaRESUMO
The two aortas of the crocodile are in open connection at two sites, the foramen of Panizzae immediately outside the ventricles, and the arterial anastomosis at the level of the gut. The present study was performed to elucidate the innervation of the cardiovascular structures of the crocodile, in part to provide a further basis for the assumption that the apertures of the foramen and the anastomosis may be altered, possibly leading to changes in the flow profiles of the central vessels. The presence of smooth muscle arranged at the circumference of the foramen and in the walls of the anastomosis was demonstrated. The cardiovascular structures were innervated by nerves containing co-existing tyrosine hydroxylase, NPY and somatostatin immunoreactivities, which also occurred in neurons of the sympathetic ganglia. CGRP and substance P immunoreactive material co-existed in cardiovascular nerves, and in the nodose ganglion. In addition, bombesin, VIP and galanin immunoreactive nerves were found. Effects of neuropeptides on blood flows and blood pressures were studied in vivo. Substance P increased all blood flows measured, NPY increased the flow through the arterial anastomosis while neurotensin caused an initial decrease in the flow through the arterial anastomosis. In conclusion, there is a rich innervation of the heart and major vessels of the estuarine crocodile, including the foramen of Panizza and the arterial anastomosis. These nerves possibly regulate the distribution of blood in the cardiovascular system, which is further suggested by the results of the injection of neuropeptides.
Assuntos
Jacarés e Crocodilos/fisiologia , Sistema Cardiovascular/inervação , Neuropeptídeos/metabolismo , Neuropeptídeos/farmacologia , Jacarés e Crocodilos/anatomia & histologia , Animais , Artérias/efeitos dos fármacos , Artérias/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Bombesina/metabolismo , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Fenômenos Fisiológicos Cardiovasculares , Sistema Cardiovascular/efeitos dos fármacos , Galanina/metabolismo , Gânglios Simpáticos/metabolismo , Coração/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Imuno-Histoquímica , Fluxometria por Laser-Doppler , Músculo Liso/efeitos dos fármacos , Neurônios/citologia , Neurônios/metabolismo , Neuropeptídeo Y/metabolismo , Neuropeptídeo Y/farmacologia , Neurotensina/metabolismo , Neurotensina/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Somatostatina/metabolismo , Substância P/metabolismo , Substância P/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo , Peptídeo Intestinal Vasoativo/metabolismoRESUMO
We present evidence to support the hypothesis that the arterial anastomosis and the cogteeth-like valves located in the sub-pulmonary conus in the right ventricle are important sites of cardiovascular regulation in the crocodile Crocodylus porosus. The influence of the arterial anastomosis on the development of the 'foramen spike' in the left aortic pressure trace, which occurs at the onset of diastole when the pressures in the right and left aortas become equal, and on gastrointestinal blood flow was examined in unanaesthetised C. porosus using blood vessel occluders. Measurements of blood flow in the arterial anastomosis showed that, during non-shunting conditions, there was a substantial systolic blood flow from the right aorta into the coeliac artery. The total coeliac artery blood flow was the sum of the anastomosis flow from the right aorta plus the left aortic flow originating from the right aorta via the foramen of Panizza during diastole. During mechanically induced pulmonary-to-systemic shunting, the anastomosis blood flow was reversed, with blood flowing from the left to the right aorta. The magnitude of the 'foramen spike' was directly related to the vascular resistance in the anastomosis. When vascular resistance in the anastomosis was high, such as during mechanical occlusion, there was an increase in the right aortic to left aortic pressure gradient during systole which resulted in an increase the foramen spike amplitude. Recordings of right intraventricular pressure in unanaesthetised C. porosus showed spontaneous changes in right intracardiac systolic pressure. The pressure recordings were biphasic, with the second contraction (isometric) being highly variable in size, indicating the control of pulmonary outflow resistance, possibly via the 'cogteeth valves' located in the sub-pulmonary conus in the right ventricle.
RESUMO
Adult freshwater rainbow trout (Oncorhynchus mykiss) were exposed acutely (approximately 20 min) in a stepwise manner to increasing levels of environmental carbon dioxide ranging between 1.7 and 9.0 mmHg (0.23-1.2 kPa). Experiments were performed to examine, for the first time, the influence of hypercapnic acidosis on aspects of cardiovascular physiology including blood pressure, cardiac output and vascular resistance. Fish displayed dose (water CO(2) partial pressure) -dependent increases in ventral aortic (13-39 %) and dorsal aortic (17-54 %) blood pressures that reflected marked increases in systemic vascular resistance (16-78 %); branchial vascular resistance was unaffected by hypercapnia. At the highest level of hypercapnia (9.0 mmHg), central venous pressure was significantly elevated by 54 %. Although cardiac output remained constant, heart rate was significantly lowered by 4-7 beats min(-)(1) at the two highest levels of hypercapnia. To determine whether the cardiovascular responses to hypercapnia were being blunted by the stepwise increase in external P(CO2), a separate group of fish was exposed directly to a single step of hypercapnia (water P(CO2) 8.0 mmHg). The cardiovascular responses were similar to those exhibited by the more gradually exposed fish except that central venous pressure did not increase and the extent of the bradycardia was greater (13 beats min(-)(1)). After confirming the effectiveness of yohimbine in blocking the vasoconstrictory (&agr;)-adrenoreceptors of the systemic vasculature, this antagonist was used as a tool to assess the importance of (&agr;)-adrenoreceptor stimulation in promoting the cardiovascular responses during hypercapnia. Prior treatment of fish with yohimbine prevented the increased blood pressures and systemic vascular resistance during hypercapnia but did not influence the CO(2)-induced bradycardia. Plasma levels of catecholamines did not change during hypercapnia, and therefore the stimulation of the systemic (&agr;)-adrenoreceptors presumably reflected increased sympathetic nerve activity. To determine whether the cardiovascular changes elicited by hypercapnia were related to acidosis-induced hypoxaemia, fish were exposed to hypoxia in a stepwise manner (water P(O2) 65-151 mmHg). The cardiovascular responses to hypoxia were markedly different from those to hypercapnia and consisted of pronounced increases in systemic and branchial vascular resistance, but only at the most severe level of hypoxia; ventral and dorsal aortic pressures were unaffected. The differences between the responses to hypercapnia and hypoxia, coupled with the smaller reductions in blood oxygen content during hypercapnia, support the hypothesis that the cardiovascular responses to CO(2) are direct and are unrelated to hypoxaemia.
RESUMO
The study of microscopic animals should be intensified because: most of the world's animal biomass consists of very small animals; life as a small animal is both qualitatively and quantitatively very different from that of a large animal; and almost all animals are very small as they begin their development. Fortunately, developing technology now allows us to make quantitative measurements in microscopic animals. This paper describes new techniques for measuring cardiovascular variables such as blood pressure, stroke volume, heart rate and cardiac output in animals weighing as little as a few mg. Non-invasive techniques such as videomicroscopy can be used for determining heart stroke volume in small animals. Impedance measurement is another non-invasive or minor invasive technique for determining rates of heart beat, gill or lung ventilation and limb movement as well as giving qualitative information on changes in blood flow. Pulsed Doppler technology can be used to obtain blood flow velocity in small vessels. Invasive techniques depend on servo-null micropressure systems that record pressure through glass microelectrodes that are implanted into the vessel or heart lumen. This allows stable pressure recordings for up to 5-6 h in animals weighing as little as a few mg. Microinjectors can be used for intravascular injections of vasoactive drugs (or blood withdrawals). Newly emerging techniques for in vivo cardiovascular measurements allow us to understand the function of the cardiovascular system in a larger portion of the world's animal biomass, as well as in the immature and as yet poorly understood early developmental stages of animals.
Assuntos
Grupos de População Animal/fisiologia , Pressão Sanguínea/fisiologia , Constituição Corporal/fisiologia , Grupos de População Animal/crescimento & desenvolvimento , Animais , Fenômenos Fisiológicos Cardiovasculares , Microscopia de VídeoRESUMO
Cardiac responses (heart rate, stroke volume, and cardiac output) to cholinergic and adrenergic receptor stimulation were investigated in developing larvae of Xenopus laevis from Nieuwkoop and Faber (NF) stage 33/34 (newly hatched) to NF stage 53 (22 d after hatching). Effects on heart rate (fH), stroke volume (SV), and cardiac output (CO) were analyzed using in situ preparations and video-microscopic techniques to record the continually beating heart. The results show that administration of acetylcholine to the heart decreases heart rate as early as NF stage 40. A significant reduction in SV and CO following acetylcholine administration to the heart was found at NF stages 45-53. Epinephrine had no significant effect on fH, SV, or CO at any of the stages investigated. However, an adrenergic tonus on the heart is present already at NF stage 40 (11%). This tonus increases up to a maximum (44%) at NF stages 45-47, when the maximal heart rate is found during development of X. laevis. We conclude that acetylcholine has a negative chronotropic and possibly also inotropic effect on the heart very early in development of X. laevis. We also hypothesize that the high adrenergic tonus found at NF stages 45-47 is responsible, at least in part, for the peak in heart rate seen at these stages.
Assuntos
Fibras Adrenérgicas/fisiologia , Fibras Colinérgicas/fisiologia , Coração/embriologia , Acetilcolina/farmacologia , Animais , Débito Cardíaco , Epinefrina/farmacologia , Coração/fisiologia , Frequência Cardíaca , Larva , Xenopus laevis/embriologiaRESUMO
Adducts, formed by carcinogens of tobacco smoke with DNA, can be detected by means of molecular techniques and are used as marker of internal exposure. Carcinogen-DNA adducts produce specific mutations in tumor-suppressor genes (e.g. p53) and oncogenes (e.g. ras), which can be involved in tumor initiation or in later stages of tumor progression (e.g. evolution of an invasive phenotype). Benzo(a)-pyrene, an important carcinogen of tobacco smoke, induces GT transversions, as demonstrated in in vitro systems and animal models. Mutations in the p53- or ras-gene are more common in human tumors of the lung, head and neck, bladder and pancreas in smokers than in non-smokers. Molecular biology of cancer gains increasing significance in clinical practice since 1.) the presence of certain mutations confers an unfavorable prognosis to malignant disease (e.g. ras mutations in lung cancer), 2.) ras and p53 mutations often occur early during tumor development and can thus facilitate diagnosis of malignant disease, and 3.) minimal residual disease can be detected using molecular techniques. After resection of cancer of the head and neck, tumor recurred more frequently in patients with no evidence of residual disease as assessed by pathohistologic criteria than in patients with no evidence of residual disease as evaluated by p53 immunostaining.
Assuntos
Carcinógenos/efeitos adversos , Transformação Celular Neoplásica/genética , Adutos de DNA/genética , Neoplasias/genética , Fumar/efeitos adversos , Poluição por Fumaça de Tabaco/efeitos adversos , Transformação Celular Neoplásica/induzido quimicamente , Análise Mutacional de DNA , Genes Supressores de Tumor/genética , Humanos , Oncogenes/genética , Prognóstico , Proteínas Proto-Oncogênicas p21(ras)/genética , Fatores de Risco , Proteína Supressora de Tumor p53/genéticaRESUMO
As shown in a previous study, intragastric administration of 16,16-dimethyl prostaglandin E2 (PGE, 100 micrograms/kg t.i.d.) for three weeks induces growth of the gastric mucosa. The present experiments were designed to study the time course of histological changes after intragastric PGE and to test whether a similar effect could be observed after parenteral administration. Significant thickening of the corpus, but not the antral mucosa was observed after 3 days of intragastric treatment with PGE (100 micrograms/kg t.i.d.), whereas after three weeks the effect was more marked in the antrum than in the corpus. At a dose of 25 micrograms/kg t.i.d., intraperitoneal PGE increased the height of antral mucosa to a similar degree as seen after intragastric treatment. DNA synthesis as assessed by autoradiography after administration of 3H-thymidine at the end of the three week PGE treatment was increased both in the gastric corpus and antrum. Preliminary studies in suckling rats provide evidence that intragastric administration of PGE (100 micrograms/kg t.i.d.) from day 7 to 11 accelerates maturation of the gastric mucosa. It is concluded that thickening of gastric mucosa can be induced by both local and systemic administration of PGE and is due, at least in part, to increased proliferation of gastric mucosal cells.
Assuntos
16,16-Dimetilprostaglandina E2/administração & dosagem , Mucosa Gástrica/citologia , Prostaglandinas E Sintéticas/administração & dosagem , 16,16-Dimetilprostaglandina E2/farmacologia , Fatores Etários , Animais , Autorradiografia , Divisão Celular/efeitos dos fármacos , DNA/biossíntese , Etanol/farmacologia , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Antro Pilórico/citologia , Antro Pilórico/efeitos dos fármacos , Antro Pilórico/metabolismo , RatosAssuntos
Chinchila , Complicações do Diabetes/veterinária , Diabetes Mellitus/veterinária , Hipertireoidismo/veterinária , Doenças dos Roedores/diagnóstico , Animais , Antitireóideos/uso terapêutico , Chinchila/sangue , Chinchila/urina , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/tratamento farmacológico , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamento farmacológico , Diagnóstico Diferencial , Feminino , Glipizida/uso terapêutico , Hipertireoidismo/complicações , Hipertireoidismo/diagnóstico , Hipertireoidismo/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metimazol/uso terapêutico , Doenças dos Roedores/tratamento farmacológico , SuíçaAssuntos
Alérgenos/imunologia , Tolerância Imunológica , Imunoglobulina G/imunologia , Lactoglobulinas/imunologia , Ovalbumina/imunologia , Linfócitos T/imunologia , Administração Oral , Alérgenos/administração & dosagem , Animais , Animais Recém-Nascidos , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/administração & dosagem , Lactoglobulinas/administração & dosagem , Ovalbumina/administração & dosagem , RatosRESUMO
BACKGROUND: Food allergy in developed countries represents a growing concern as reflected by epidemiological studies, indicating that up to 4% of the overall population is affected. Reduction of symptoms takes place following eviction or processing of some allergens. However, it cannot be predicted which structural changes will be associated with significant effects on the allergenicity. OBJECTIVE: To determine how various treatments of bovine beta-lactoglobulin (BLG) used as a model antigen alters its immunoreactivity and transepithelial transport, and whether this correlates with reduced allergenicity using an in vitro basophil activation assay. METHODS: BLG was subjected to reduction/alkylation, trypsin digestion or exposed to Lactococcus lactis. The remaining immunoreactivity toward IgG raised against native BLG was assessed by ELISA. Transepithelial transport of BLG and derivatives was examined using polarized Caco-2 cell monolayers mimicking the intestinal epithelium. Selective passage of tryptic peptides was determined using colchicine and cytochalasin D. Basophil activation was measured following stimulation with BLG and derivatives. RESULTS: Reduction/alkylation, trypsin digestion or incubation with L. lactis was associated with decreased BLG recognition by IgG antibodies raised against the native protein. All treatments also resulted in a more efficient transepithelial transport of BLG. BLG crossed the Caco-2 monolayer through passage across the cell, whereas tryptic peptides followed both the para- and transcellular routes. With the exception of denaturation by reduction/alkylation, cross-linking of IgE antibodies by BLG derivatives led to lower basophil degranulation. CONCLUSION: In vitro dissection of antigenicity and allergenicity may be a valid and convenient alternative to evaluate the effects of biotechnological processing on dietary proteins. In addition, it can help to define the molecular and cellular mechanisms that will provide improved means of diagnosis and possibly therapy of food-allergic disorders.