Search results for "Digestive System"
showing 10 items of 1747 documents
Immunohistological differential diagnosis of inflammatory colonic diseases.
1984
Immunohistological investigations were carried out on human colonic tissue from, I healthy mucosa, 2 slightly inflamed mucosa, 3 mucosa with ulcerative colitis, 4 mucosa with Crohn's colitis, using antibodies against immunoglobulins and complement components. All our antibodies, including F(ab')2 fragments, demonstrated a progressive increase of labelled cells from healthy mucosa through slightly inflamed mucosa to mucosa with ulcerative colitis, in contrast to a complete absence of labelled cells in cases of Crohn's disease. The results are discussed with regard to their pathogenesis and their clinical significance for the differentiation of ulcerative colitis and Crohn's colitis.
Complex Cellular Responses of Helicobacter pylori-Colonized Gastric Adenocarcinoma Cells ▿
2011
ABSTRACT Helicobacter pylori is an important class I carcinogen that persistently infects the human gastric mucosa to induce gastritis, gastric ulceration, and gastric cancer. H. pylori pathogenesis strongly depends on pathogenic factors, such as VacA (vacuolating cytotoxin A) or a specialized type IV secretion system (T4SS), which injects the oncoprotein CagA (cytotoxin-associated gene A product) into the host cell. Since access to primary gastric epithelial cells is limited, many studies on the complex cellular and molecular mechanisms of H. pylori were performed in immortalized epithelial cells originating from individual human adenocarcinomas. The aim of our study was a comparative anal…
In Situ Perfusion Model in Rat Colon for Drug Absorption Studies: Comparison with Small Intestine and Caco-2 Cell Model.
2015
Our aim is to develop and to validate the in situ closed loop perfusion method in rat colon and to compare with small intestine and Caco-2 cell models. Correlations with human oral fraction absorbed (Fa) and human colon fraction absorbed (Fa_colon) were developed to check the applicability of the rat colon model for controlled release (CR) drug screening. Sixteen model drugs were selected and their permeabilities assessed in rat small intestine and colon, and in Caco-2 monolayers. Correlations between colon/intestine/Caco-2 permeabilities versus human Fa and human Fa_colon have been explored to check model predictability and to apply a BCS approach in order to propose a cut off value for CR…
IN SITU HYBRIDIZATION FOR DETECTION OF HEPATITIS B VIRUS GENOMES IN LIVER TISSUE OF CHRONIC INFECTED CHILDREN
1990
Detection of hepatitis B virus (HBV)-DNA in the liver of chronic infected patients is presently the most sensitive marker of viral replication and infectivity. In situ hybridization (ISH) allows the direct visualization of HBV infected liver cells and distribution of the viral sequences. This study was done to establish ISH and correlate the findings with conventional markers for HBV infection. Methods. Liver biopsies of 50 patients (28 ♂, 22 ♀) aged 0.5-20 years (mean 10.3) with various histological diagnoses were tested by 1SH. The HBV-DNA probe was labeled by nick translation with 35S-CTP to a specific activity of 3-5×108 cpm/μg DNA. Results. HBV-DNA/mRNA could be demonstrated in 38 pati…
Viability RT-qPCR to detect potentially infectious enteric viruses on heat-processed berries
2019
Berries have frequently been cited as causing gastroenteritis and acute hepatitis outbreaks due to enteric virus contamination, including human norovirus and hepatitis A virus (HAV). Model experiments were performed to evaluate the potential use of viability RT-qPCR to assess the thermal inactivation of norovirus genotype I (GI), GII, and HAV on raspberries, blueberries and strawberries. Initially, two viability markers, platinum chloride and propidium monoazide (PMAxx™), were compared using thermally inactivated norovirus GI and GII suspensions. The results showed better performance of PMAxx™ pretreatment in discriminating native and inactivated viruses. Thus, the pretreatment was optimize…
Significance and relevance of serum preS1 antigen detection in wild-type and variant hepatitis B virus (HBV) infections
1993
These studies assessed whether the serum expression of preS1 antigen could be a useful HBV marker for monitoring the progress of antiviral therapy in the treatment of chronic active hepatitis B (CAH-B) virus infections. Our findings indicate that: 1) the rearrangements we observed in the preS region of mutated HBV DNA molecules during chronic infection did not effect the preS1 sequence (21–47) critical for HBV infectivity; 2) the persistence or even the rebound of preS1 antigen expression during follow-up in responders to antiviral therapy may indicate virus persistence, suggesting the possibility of relapse through wild-type HBV or the emergence of HBV variants following the immunoeliminat…
Real-Life Use of Biosimilars in Pediatric Inflammatory Bowel Disease: A Nation-Wide Web Survey on Behalf of the SIGENP IBD Working Group
2022
Objective: The aim was to assess the awareness and real-life use of biosimilars in inflammatory bowel disease (IBD) among the members of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP). Methods: An anonymous web survey involving all SIGENP IBD units which can prescribe biosimilars was conducted between July 1st and December 1st, 2020. The questionnaire included 18 questions addressing the most relevant aspects of biosimilars in pediatric IBD, i.e., advantages, disadvantages, costs, traceability, general knowledge, and real-life use. A descriptive analysis of responses was performed. Results: Responses came from 26 pediatric IBD units in Italy, with repre…
Lack of Detrimental Effects of Bacillus thuringiensis Cry Toxins on the Insect Predator Chrysoperla carnea : a Toxicological, Histopathological, and …
2006
ABSTRACT The effect of Cry proteins of Bacillus thuringiensis on the green lacewing ( Chrysoperla carnea ) was studied by using a holistic approach which consisted of independent, complementary experimental strategies. Tritrophic experiments were performed, in which lacewing larvae were fed Helicoverpa armigera larvae reared on Cry1Ac, Cry1Ab, or Cry2Ab toxins. In complementary experiments, a predetermined amount of purified Cry1Ac was directly fed to lacewing larvae. In both experiments no effects on prey utilization or fitness parameters were found. Since binding to the midgut is an indispensable step for toxicity of Cry proteins to known target insects, we hypothesized that specific bind…
Proteolytic processing of Bacillus thuringiensis Vip3A proteins by two Spodoptera species
2014
Abstract Vip3 proteins have been described to be secreted by Bacillus thuringiensis during the vegetative growth phase and to display a broad insecticidal spectrum against lepidopteran larvae. Vip3Aa protoxin has been reported to be significantly more toxic to Spodoptera frugiperda than to Spodoptera exigua and differences in the midgut processing have been proposed to be responsible. In contrast, we have found that Vip3Ae is essentially equally toxic against these two species. Proteolysis experiments were performed to study the stability of Vip3A proteins to peptidase digestion and to see whether the differences found could explain differences in toxicity against these two Spodoptera speci…
Combining Hexanoic Acid Plant Priming with Bacillus thuringiensis Insecticidal Activity against Colorado Potato Beetle
2013
Interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in Colorado potato beetle (CPB) pest management. Feeding tests with CPB larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to Bacillus thuringiensis Cry3Aa toxin as a function of the host plant. An inverse correlation with toxicity was observed in Cry3Aa proteolytic patterns generated by CPB midgut brush-border membrane vesicles (BBMV) from Solanaceae-fed larvae, being the toxin most extensively proteolyzed on potato, followed…