Published Article / The LPS, endotoxin of Gram-negative organisms in communal growth as compared to pure culture was the focus of this research. The experiment aimed to show pure and communal samples grown in the presence of the extrinsic stresses. The change in toxicity was measured using the Limulus Amoebocyte Lysate (LAL) test. The overall sensitivity of organisms was similar for the same sanitiser and the same detergent. Growth in community was found not to be the arithmetic sum of the individual growth patterns. The detergents had a marked effect on the growth of all samples throughout the growth cycle. This finding reveals that the acceptable refrigeration temperatures still allows for pathogen growth and thus for biofilm formation. The quantification by LAL showed that the enumeration of the food-borne pathogens isolated from households might not be indicative of acclimatisation obtained over short periods of time and the causal stress could turn these organisms into more or less toxic pathogens.

The hygiene hypothesis, as originally proposed, postulated an inverse relation between the incidence of infectious diseases in early life and the subsequent development of allergies and asthma. New evidence from epidemiological, biological and genetic studies has significantly enlarged the scope of the hypothesis. It now appears probable that environmental 'danger' signals regulate the pattern of immune responses in early life. Microbial burden in general, and not any single acute infectious illness, is the main source of these signals. The latter interact with a sensitive and complex receptor system, and genetic variations in this receptor system may be an important determinant of inherited susceptibility to asthma and allergies.

No description available.

No description available.

No description available.

No description available.

Submitted by DAIANA CAVALLI null (daiana.cavalli@gmail.com) on 2017-02-17T11:12:38Z No. of bitstreams: 1 DISSERTAÇÃO FINALIZADA + FICHA CATALOGRÁFICA DAIANA CAVALLI.pdf: 2334414 bytes, checksum: fb47eeb7d11ed5a1b0e89770fef8b691 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-02-21T20:10:03Z (GMT) No. of bitstreams: 1 cavalli_d_me_sjc.pdf: 2334414 bytes, checksum: fb47eeb7d11ed5a1b0e89770fef8b691 (MD5) / Made available in DSpace on 2017-02-21T20:10:03Z (GMT). No. of bitstreams: 1 cavalli_d_me_sjc.pdf: 2334414 bytes, checksum: fb47eeb7d11ed5a1b0e89770fef8b691 (MD5) Previous issue date: 2016-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os objetivos deste trabalho são: 1) Quantificar por checkerboard a carga microbiana e pelo método de LAL endotoxinas (EU/mL) nas infecções endodônticas primárias; 2) Realizar o monitoramento dos níveis de endotoxinas (EU/mL) e de carga microbiana antes do tratamento, após o preparo biomecânico com sistemas de instrumentação rotatória, reciprocante e híbrida e após o uso da medicação intracanal; 3) Relacionar sinais e sintomas clínicos com níveis de endotoxinas, micro-orgnismos e com complexos bacterianos; 4) Relacionar volumetria dos canais radiculares por meio de TCFC com níveis de endotoxina, micro-organismos e complexos bacterianos. Trinta dentes com infecção endodôntica primária e presença de lesão periapical foram submetidos a TCFC antes do tratamento e avaliados quanto a presença de sinais e sintomas clínicos. Após abertura coronária, foi realizada a coleta inicial nos canais radiculares, e em seguida, procedeu-se com o tratamento endodôntico, sendo os dentes divididos em diferentes grupos experimentais de acordo com o sistema de instrumentação utilizado (n=10): rotatório Mtwo (MTWO), reciprocante Reciproc (REC), e híbrido Genius (GEN). Durante o preparo biomecânico, os canais foram irrigados com 24 mL de NaOCl 2,5%. Foram realizadas coletas do conteúdo dos canais radiculares: logo após a abertura coronária (1 col), após a instrumentação (2 col), e após a MIC por 14 dias, realizada com pasta de hidróxido de cálcio associada a solução salina fisiológica (3 col). A detecção de micro-organimos foi realizada pelo teste checkerboard DNA-DNA hybridization. A quantificação de endotoxinas foi realizada pelo teste cinético cromogênio do lisado de amebócito de Limulus. As volumetrias dos canais radiculares foram realizadas com auxílio do software Nemotec®. Todos os dados foram analisados estatisticamente. Os resultados mostraram a detecção de micro-organismos e endotoxinas em 100% das amostras iniciais, sendo as bactérias C. ochracea e F. nucleatum as mais prevalentes (53%). Após o PBM, os micro-organismos mais encontrados foram F. nucleatum e L. buccalis (50%); e após a MIC C. gracilis (53,3%). Não houve diferença estatística entre os grupos quanto à redução da carga microbiana. Quanto as endotoxinas, logo após o PBM, o grupo que mais reduziu foi o MTWO, seguido por GEN e REC; após a MIC, o grupo que mais reduziu foi o GEN, seguido pelo MTWO e REC, porém todos os grupos se comportaram de maneira semelhante. Dor espontânea foi relacionada com P. nigrescens; dor a percussão com P. gingivalis, V. parvula, S. sputigena, P. nigrescens e E. saburreum; presença de fístula foi relacionada com o complexo laranja, Gram-positivas e anaeróbios facultativos, e micro-organismos E. corrodens, P. micra, C. showae e E. saburreum. O maior volume do canal radicular foi correlacionado fortemente com anaeróbios estritos, com o complexo laranja e o micro-organismo P. micra. O PBM foi efetivo na redução de bactérias e endotoxinas do canal radicular, mas sem diferença estatística entre os três sistemas utilizados. Conclui-se que o PBM com NaOCl 2,5% é eficaz na redução de endotoxinas e na remoção de micro-organimos do canal radicular; sinais e sintomas são relacionados com micro-organismos, assim como a volumetria do canal radicular. / The aims of this study are: 1) Quantify by checkerboard test the microbial load and endotoxins through LAL method (EU/ml) in primary endodontic infections; 2) To monitore levels of endotoxin (EU/ml) and microbial load before treatment, after biomechanical preparation with rotatory, reciprocating and hybrid instrumentation systems, and after use of intracanal medication; 3) To associate clinical signs and symptoms with endotoxin levels, microorganism and bacterial complexes; 4) To relate volumes of root canals through cone beam computed tomography (CBCT), with endotoxin levels, microorganisms and bacterial complexes. Thirty teeth with primary endodontic infection and periapical lesion were submitted to endodontic treatment after CBCT and evaluated the presence of clinical signs and symptoms. After coronary opening, the initial samples were collected to verify the presence of infection in root canals. Then, teeth were divided into different experimental groups according to the instrumentation system used (n=10): rotatory Mtwo (MTWO), reciprocating Reciproc (REC), and hybrid Genius (GEN). During biomechanical preparation, the canals were irrigated with 24 mL of 2.5% NaOCl. Samples were collected: after coronary opening (S1), after the instrumentation (S2) and after intracanal medication for 14 days with calcium hydroxide paste and physiological saline solution (S3). The detection of microorganisms was performed by checkerboard DNA-DNA hybridization technique. The endotoxin quantification was performed by chromogenic kinetic test of the Limulus amoebocyte lysate. The root canal volumetries were performed by Nemotec® software. All data were analyzed statistically. The results showed the detection of microorganisms and endotoxins in 100% of the S1, with the most prevalent bacteria being C. ochracea and F. nucleatum (53%). After biomechanical preparation, the most found microorganisms were F. nucleatum and L. buccalis (50%); And after intracanal medication C. gracilis (53.3%). There was no statistical difference between the groups regarding the reduction of the microbial load. In relation to endotoxins, after biomechanical preparation, the group with greatest reduction was MTWO, followed by GEN and REC; after intracanal medication, the group with greatest reduction was GEN, followed by MTWO and REC, but there was no statistical difference between them. Spontaneous pain was associated to P. nigrescens; tenderness to percussion with P. gingivalis, V. parvula, S. sputigena, P. nigrescens and E. saburreum; sinus tract was related to the orange complex, Gram-positive and facultative anaerobes, and microorganisms E. corrodens, P. micra, C. showae and E. saburreum. The root canal volume was strongly correlated with strict anaerobes, with the orange complex and the P. micra microorganism. Biomechanical preparation was effective in decreasing bacteria and endotoxin, but with no statistical difference were found between the three systems. Microorganisms are related to signs and symptoms and to root canal volume. In conclusion, biomechanical preparation with 2.5% NaOCl was effective on reducing endotoxins and decreasing microorganisms from root canals; signs and symptoms are related to microorganisms as well as root canal volumetry.

Background Immune responses, including those to allergens, may be T helper (Th)2 skewed in newborns. In order to redress the fetal Th1/Th2 imbalance, Th1-stimulating factors, such as bacterial endotoxin, may be required. The increasing prevalence and severity of atopic diseases in industrialized countries, which are in marked contrast with the low prevalence of allergy among children in the formerly socialist countries of Europe, have been suggested to be caused by a reduced microbial stimulation. Aim To relate the endotoxin levels in house dust from two countries with a low (Estonia) and a high (Sweden) prevalence of allergy to the development of atopic disease and sensitization in the children during the first 2 years of life. Methods The study included 108 children from Tartu, Estonia and 111 children from Linköping, Sweden. Skin prick tests were performed at 3, 6, 12 and 24 months of age, and questionnaires were distributed to the families. At 24 months, a paediatrician examined the children. Dust samples were collected from mattresses and carpets and the endotoxin concentration was determined by a chromogenic Limulus assay. Results The endotoxin levels were higher in Estonian than in Swedish house dust (median levels 29 (range 0.25–280) and 14 (range 0.25–99) EU/mg dust, respectively, P < 0.001). Furthermore, the levels were inversely related to the development of atopic disease and sensitization in the Swedish, but not in the Estonian, children. Conclusions The low prevalence of atopic disease in Estonia may, at least in part, be related to the high endotoxin levels in this country. The findings support that high levels of endotoxin, or other bacterial products with Th1-stimulating properties, might protect children from developing atopic disease.

Endotoxin (lipopolysaccharide, LPS), is a constituent of the outer membrane of Gram-negative bacteria, activates macrophages to release cytokines that can cause local or systemic inflammatory responses. Plasma leakage and polymorphonuclear leukocyte infiltration are characteristic features of inflammation. This study examined the effect of LPS to induce subcutaneous inflammatory lesions, including time course of changes in plasma extravasation and level of leukocyte influx into the tissue interstitium. To investigate LPS-induced plasma leakage in the skin, LPS (500 £gg/site) was administered by subcutaneous injection in the hindpaw skin. India ink (1 ml/kg) was used as tracer dye to measure the area density of ink-labeled leaky blood vessels. Our results showed that the postcapillary venules were leaking immediately at five minutes after LPS. The area density of India ink-labeled leaky vessels was 33.9 %¡Ó5.6 % (n=5) after the administration of LPS. The magnitude of plasma leakage was 2 times as the value of saline control (16.6 %¡Ó1.8 %, n=5). Plasma leakage peaked at 30 min (42.5 %¡Ó2.5 %, n=11) after LPS. Staining of the microvasculature by silver nitrate showed endothelial gap formation in venules and indicated the positive relevance to plasma leakage. Leukocytes (neutrophils and eosinophils) in hindpaw skin whole mounts were stained by a histochemical reaction for myeloperoxidase and the numbers of leukocytes quantified. LPS caused a severe response in leukocyte adhesion and accumulation. The number of leukocytes after LPS was 5 times as the number after saline. It is concluded that local injection of LPS in the skin caused formation of endothelial gaps and leukocyte infiltration that resulted in an increase in local vascular permeability.

Zugl.: Berlin, Freie Universiẗat, Diss., 2008.