<p>The crayfish plague refractory crayfish, <i>Pacifastacus leniusculus</i>, which can harbour the fungal parasite within melanotic sheath, are found to constitutively express the gene encoding for prophenoloxidase (proPO) after mimicking parasite attack. In contrast, the susceptible crayfish, <i>Astacus astacus</i>, responds to the parasite by increased levels of proPO transcript, particularly in the semigranular haemocytes. The upregulation of proPO could confer a temporary resistance towards the fungal infection, suggesting that additional factors are involved in maintaining the balance between host and parasite. The resistant crayfish may have adapted to the parasite by increasing the transcript level of immune genes. The parasite can be considered as a symbiont since it does not harm the host rather than it activates the immune gene and possibly preventing other pathogens to become established.</p><p>Two serine proteinase genes encoding a subtilisin-like (<i>AaSP1</i>) and a trypsin (<i>AaSP2</i>) enzyme were isolated from the crayfish plague fungus, <i>Aphanomyces astaci</i>. These proteinases are prepropeptides and generate mature proteins of 39 kDa and 29 kDa, respectively. Characterisation of <i>AaSP1</i> suggests that the enzyme may be involved in intracellular control mechanisms rather than playing a role in pathogenesis. The <i>AaSP2 </i>transcript was not controlled by catabolic repression, but was induced by crayfish plasma, implying a role in pathogenesis toward the crayfish host. </p><p>Physiology and genetics of five <i>Aphanomyces</i> strains, which were isolated from moribund crayfish, were characterised with regard to their pathogen diversity. These strains are not virulent against crayfish. Some physiological properties of these strains differed from <i>A. astaci</i>, such as growth rate, germination and production of chitinase. Genetic analysis clearly indicated that they are not related to <i>A. astaci</i> and their name are proposed to be <i>Aphanomyces repetans</i>.</p><p>The crayfish <i>P. leniusculus </i>was found to be susceptible to white spot syndrome virus infection. The virus has a significant effect to the population of crayfish haemocyte. The number and proportion of granular cell from virus-infected crayfish were higher than in controls, indicating granular cells are more resistant to and may interact by some means with the virus.</p><p>Two morphotypes of the crayfish parasite <i>Psorospermium haeckeli</i> obtained from different crayfish hosts of different geographical origin were analysed for ribosomal ITS DNA in order to compare their genetic diversity. The sequence difference between them was found largely in ITS 1 and ITS 2 regions, which was variable in length and showed 66% and 58% sequence similarity. Thus, different morphotypes of <i>P. haeckeli</i> are genetically diverse.</p>

The crayfish plague refractory crayfish, Pacifastacus leniusculus, which can harbour the fungal parasite within melanotic sheath, are found to constitutively express the gene encoding for prophenoloxidase (proPO) after mimicking parasite attack. In contrast, the susceptible crayfish, Astacus astacus, responds to the parasite by increased levels of proPO transcript, particularly in the semigranular haemocytes. The upregulation of proPO could confer a temporary resistance towards the fungal infection, suggesting that additional factors are involved in maintaining the balance between host and parasite. The resistant crayfish may have adapted to the parasite by increasing the transcript level of immune genes. The parasite can be considered as a symbiont since it does not harm the host rather than it activates the immune gene and possibly preventing other pathogens to become established. Two serine proteinase genes encoding a subtilisin-like (AaSP1) and a trypsin (AaSP2) enzyme were isolated from the crayfish plague fungus, Aphanomyces astaci. These proteinases are prepropeptides and generate mature proteins of 39 kDa and 29 kDa, respectively. Characterisation of AaSP1 suggests that the enzyme may be involved in intracellular control mechanisms rather than playing a role in pathogenesis. The AaSP2 transcript was not controlled by catabolic repression, but was induced by crayfish plasma, implying a role in pathogenesis toward the crayfish host. Physiology and genetics of five Aphanomyces strains, which were isolated from moribund crayfish, were characterised with regard to their pathogen diversity. These strains are not virulent against crayfish. Some physiological properties of these strains differed from A. astaci, such as growth rate, germination and production of chitinase. Genetic analysis clearly indicated that they are not related to A. astaci and their name are proposed to be Aphanomyces repetans. The crayfish P. leniusculus was found to be susceptible to white spot syndrome virus infection. The virus has a significant effect to the population of crayfish haemocyte. The number and proportion of granular cell from virus-infected crayfish were higher than in controls, indicating granular cells are more resistant to and may interact by some means with the virus. Two morphotypes of the crayfish parasite Psorospermium haeckeli obtained from different crayfish hosts of different geographical origin were analysed for ribosomal ITS DNA in order to compare their genetic diversity. The sequence difference between them was found largely in ITS 1 and ITS 2 regions, which was variable in length and showed 66% and 58% sequence similarity. Thus, different morphotypes of P. haeckeli are genetically diverse.

Made available in DSpace on 2015-05-14T12:56:07Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2499199 bytes, checksum: ba2f9cd3497696e4d2f7095983ffe2db (MD5) Previous issue date: 2009-12-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to measure the bioavailability of fluoride in saliva and to observe the pattern of urinary fluoride excretion in children exposed to topical fluoride products of professional use. Seventeen children of 6- 12-years-old, both genders with active white spots on smooth surfaces, no cavities and needing fluoride treatment were included in the study. All volunteers (n=17) received toothbrushes and fluoridated toothpaste (1,100 ppm, 11 volunteers) and no fluoride (6 volunteers) eight days before fluoride a application. A wash-out period of 7 days was established before and after the exposure of neutral gel fluoride (9,000 ppm), foam (12,300 ppm) and varnish (22,600 ppm). Except for the varnish, the fluoridated gel (5g) and foam (1.5g) were applied in trays. /the products were applied for one minute covering all buccal surfaces. Saliva was collected in the following times: 0, 3, 6, 9, 15, 30, 45 and 60 minutes. Urine was collected covering the 24 hours of baseline and after application of the products covering 11 and 13 hours of collection to cover day and night periods as (7:00-18:00 h) and (18:00-7:00 h). Fluoride was measured with the aid of ion specific electrode ORION (9409BN) coupled to a potenciometer (720 A,ThermoOrion). Data statistical analyses were performed in SPSS v. 13.0 applying p< 0.05. The results indicated a higher concentration of fluoride in saliva after 3 minutes of using varnish, foam and gel, the values are 95.02 ± 82.2 ppmF, ppmF 41.0 ± 75.51 and 99.33 ± 59, 8 ppm F, respectively. The excretion of fluoride in urine was higher for varnish, foam and gel, the values are 1.1 ± 7.1 ppm F, 0.6 ± 0.3 ppm F and 0.6 ± 0.6 ppm F, respectively. It can be concluded that the highest values of salivary fluoride regardless the time of measurement were achieved by the fluoride varnish. For the urinary fluoride followed a similar trend showing higher values for the varnish and suggesting that this product can produce a high ingestion of fluoride. / O objetivo desse estudo foi de mensurar a concentração de flúor em saliva e na urina de crianças expostas a fluoretos tópicos de uso profissional. O delineamento desse estudo é clínico, aleatório e cruzado. Participaram 17 crianças com idades entre 6 e 12 anos, de ambos os sexos, com manchas brancas ativas em superfícies lisas, necessitando de fluorterapia. Escovas e dentifrícios foram fornecidos aos voluntários, onde n= 11 receberam dentifrício de 1.100 ppm e n= 6 dentifrício sem flúor. Os produtos fluoretados utilizados foram: gel neutro (9.000 ppm), espuma neutra (12.300 ppm) e verniz (22.600 ppm). As aplicações do gel (5g) e a espuma (1,5g) foram em moldeiras por 1 minuto e o verniz (0,5g) com pincel, cobrindo toda a superfície vestibular do dentes. As coletas de saliva foram feitas no dia da aplicação dos produtos fluoretados nos seguintes tempos: 0, 3, 6, 9, 15, 30, 45 e 60 minutos. As coletas de urina foram feitas por 24 horas. Sendo, 24 horas dividida em dois períodos: diurno ou 11horas (coleta das 7:00 h às 18:00 h) e período noturno ou de 13 horas (coleta das 18:00 h às 7:00 h). Nas análises das amostras de saliva e urina utilizou-se um eletrodo combinado íon-específico da ORION (9409BN) com eletrodo de referência (900200), ambos acoplados a um potenciômetro 720 A (ThermoOrion). Os dados foram digitados no SPSS v. 13.0, submetidos a testes estatísticos e considerados significativos com p< 0,05. Os resultados indicaram uma maior concentração de flúor na saliva após 3 minutos de uso do verniz, gel e espuma, os valores (ppmF) foram de 99,33 ± 59,8; 95,02 ± 82,2 e 75,51 ± 41,0, respectivamente. A excreção de flúor na urina foi maior para verniz, espuma e gel com valores (ppmF) de 1,1± 7,1; 0,6 ± 0,3 e 0,6± 0,6, respectivamente. Pode-se concluir que os valores mais elevados de flúor na saliva independentemente do tempo de medição foram obtidos com o verniz. Para a excreção do flúor seguiu uma tendência semelhante, apresentando valores mais elevados para o verniz e sugerindo que este produto pode produzir uma elevada ingestão de flúor.

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-12-22T13:41:24Z No. of bitstreams: 1 AmbrosioPBJ_TESE.pdf: 1565908 bytes, checksum: 8e51f42daddfb44d1d69d9f37babeec1 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-02-20T14:29:25Z (GMT) No. of bitstreams: 1 AmbrosioPBJ_TESE.pdf: 1565908 bytes, checksum: 8e51f42daddfb44d1d69d9f37babeec1 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-02-20T14:31:54Z (GMT) No. of bitstreams: 1 AmbrosioPBJ_TESE.pdf: 1565908 bytes, checksum: 8e51f42daddfb44d1d69d9f37babeec1 (MD5) / Made available in DSpace on 2018-02-20T14:32:02Z (GMT). No. of bitstreams: 1 AmbrosioPBJ_TESE.pdf: 1565908 bytes, checksum: 8e51f42daddfb44d1d69d9f37babeec1 (MD5) Previous issue date: 2017-11-27 / Aquaculture studies seem to be basically based on environmental and economic terms in isolation, not considering the interaction of these factors, and rarely taking into account the social costs and benefits involved in the activity, so the objective of this research was to evaluate sustainability economic, environmental and social aspects in the creation of Litopenaeus vannamei shrimp in different management strategies and storage densities. For this purpose, densities of 92 (M1), 14 (M2) and 8 (M3) shrimp.m-2 and with maximum culture time of 79 days. The sedimentation rates, with the exception of total inorganic carbon-TIC and total organic carbon-TOC, were significantly higher in M3 when compared to M1 and M2, in the first collection period, probably influenced by management in the first stage (greenhouse), a tendency of decrease was verified for most of nutrient sedimentation rates for the end of the cycle, and may be associated with the bacterial community that may have aided in the reduction of these compounds. Survival was reduced in all treatments, probably influenced by white spot disease and high water salinity of farms raising the apparent feed conversion factor-FCAA in M1 and M2. The internal rates of return for M2 and M3 were attractive, generating a positive net profit and a positive balance and were able to guarantee the return on invested capital. However, this return on capital only occurred due to the high prices practiced in 2016. The cultivation with high initial population (M1) caused economic and zootechnical losses due to the high FCAAs, reduced individual biomass and the high total operational costs - making this treatment unfeasible. In the social evaluation, an income distribution of the negative order for M1 was verified due to the high costs of production, thus creating losses for this treatment. M2 and M3 presented a reduced income distribution, with a labor compensation of R $ 0.70 and R $ 1.06, respectively, representing 48 and 32% of production costs (COT). The greater distance from the economic dimension to the M1 treatment may be associated with the high RB and COT results. The treatments M2 and M3 were those that presented positive IRR, demonstrating the economic viability, probably due to the high prices per kilo of shrimp practiced during this period. Sustainability was committed by the generation of solid waste, since much of the particulate matter produced in shrimp farms is formed by a collective action of chemicals, fertilizers, excrement, undigested food, unwanted organisms and debris. It is worth noting that the white spot negatively affected the economic and social sustainability of all treatments. M1 was the most favorable environmental treatment with a social tendency. We can conclude that the monoculture of shrimp when carried out with high initial populations can not guarantee the return of invested capital. M2 and M3 were only economically viable due to the high prices paid per kilo of shrimp, but with low employment and income generation, not being socially fair and with greater impact on the environment / Os estudos em aquicultura parecem se pautar basicamente em termos ambientais e econômicos de forma isolada, não considerando a interação destes fatores, e raramente levando em considerações os custos e benefícios sociais envolvidos na atividade, desta forma o objetivo desta pesquisa foi avaliar a sustentabilidade econômica, ambiental e social na criação do camarão marinho Litopenaeus vannamei em diferentes estratégias de manejo e densidades de estocagem. Para tanto foram utilizadas densidades de 92 (M1), 14 (M2) e 8 (M3) cam.m-2 e com tempo máximo de cultivo de 79 dias. As taxas de sedimentação, com exceção do carbono inorgânico total-CIT e carbono orgânico total-COT, foram significativamente superiores em M3 quando comparado a M1 e M2 no primeiro período de coleta, provavelmente influenciadas pelo manejo na primeira fase (estufa). Foi verificado uma tendência de decréscimo para a maioria das taxas de sedimentação de nutrientes para o final do ciclo, podendo estar associada a comunidade bacteriana que pode ter auxiliado na redução desses compostos. As sobrevivências foram reduzidas em todos os tratamentos, provavelmente influenciadas pela doença da mancha branca e a elevada salinidade da água dos viveiros de criação elevando o FCAA em M1 e M2. As taxas internas de retorno para M2 e M3 foram atrativas, gerando lucro e saldo positivo para o valor presente líquido e conseguiram garantir o retorno do capital investido. Esse retorno do capital, no entanto, somente ocorreu devido aos preços elevados praticados em 2016. O cultivo com população inicial elevada (M1), ocasionou prejuízos econômicos e zootécnicos devido aos elevados FCAAs, biomassa individual reduzida e aos elevados custos totais operacionais-CTO, tornando inviável esse tratamento. Na avaliação social foi verificada uma distribuição de renda da ordem negativa para M1 em função dos elevados custos de produção, configurando prejuízos para esse tratamento. M2 e M3 apresentaram distribuição de renda reduzida, sendo a remuneração da mão de obra de R$ 0,70 e R$ 1,06 respectivamente, representando 48 e 32% dos custos de produção (CTO). O maior distanciamento da dimensão econômica para o tratamento M1 pode estar associado aos resultados elevados com RB e CTO. Os tratamentos M2 e M3 foram os que apresentaram TIR positiva, demonstrando a viabilidade econômica, provavelmente em função dos preços elevados por quilo de camarão praticados nesse período. A sustentabilidade foi comprometida pela geração de resíduos sólidos, visto que grande parte do material particulado produzido em viveiros de camarão é formada por uma ação coletiva de produtos químicos, fertilizantes, excrementos, alimentos não digeridos, organismos indesejados e detritos. Vale salientar ainda que, a mancha branca comprometeu negativamente a sustentabilidade econômica e social de todos os tratamentos. M1 foi o tratamento mais favorável ambiental com tendência para o social. Podemos concluir que o monocultivo de camarão quando realizado com elevadas populações inicias não consegue garantir o retorno do capital investido. M2 e M3 só foram viáveis economicamente em função dos preços elevados pagos por quilo de camarão, porém com reduzida geração de emprego e renda, não sendo socialmente justo e com maior impacto ao meio ambiente / 2017-12-22

Made available in DSpace on 2015-03-26T13:37:41Z (GMT). No. of bitstreams: 1 texto completo.pdf: 372194 bytes, checksum: 1ce7a898936fa3c0ddc79d75753c89e2 (MD5) Previous issue date: 2009-07-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The main objectives of this work were to identify the causal agent of the maize White Spot, to obtain preliminary information on the disease dispersal in the field and to characterize the reaction of maize hybrids and inbreds to the disease. For the etiological studies, isolations were performed from white spot lesions the anasarca phase, resulting in the development of bacterial colonies. Maize hybrids BRS2022, BRS1010, 1D2195, BRS1040, BRS1035, BRS1031, BRS3025, BRS1030, 2B710 e P30F35 and inbred lines L3, L228-3, 521274, 521236 e 262841-1-4-1 were evaluated under natural epidemic in a randomized block design with three replications. Cultivars were planted in single row plots, separated by two rows of the resistant hybrid BRS1010. Spreader rows were formed by planting the susceptible genotype DAS657 0,5 m apart and in front of each block. Disease severity was evaluated at a weekly internal starting 60 days after planting, through a 1 to 9 scale of disease severity where 1= no disease and 9= 100% of leaf area affected. Ratings were taken at three different locations within each plot: 1, 2, 3, 4, 5 and 6 meters inoculum source. Data were used for the calculation of the area under disease progress curve (AUDPC), disease severity at 50% of epidemic development (Y50), disease severity at the end of the epidemic, and the rate of disease progress. Inoculations on the susceptible hybrid DAS657, in the greenhouse, reproduced the typical symptoms of the disease. Re-isolations from theses lesions confirmed the presence of the same bacteria isolated from the field, which identified as Pantoea ananatis, confirming previous reports on the involvement of this bacteria in the initial lesions of this disease. No disease gradient was observed based on the disease severity observed in each point of evaluation within each plot. A better distinction between the level of resistance of maize genotypes was obtained through AUDPC and Ymáx values. Maize hybrids BRS1030, BRS1035 and BRS1010 and inbreds L3, and L228-3 were the most resistant genotypes. These inbred lines may be useful in breeding programs for resistance to maize white spot. / Este trabalho objetivou confrimar o agente causal da mancha-branca do milho, obter informações preliminares sobre a dispersão do patógeno e caracterizar a reação de genótipos de milho a doença. Para o estudo etiológico, isolados foram obtidos de lesões de manchabranca em fase de anasarca, resultando em desenvolvimento de colônias bacterianas. Híbridos de milho, BRS2022, BRS1010, 1D2195, BRS1040, BRS1035, BRS1031, BRS3025, BRS1030, 2B710 e P30F35 e as linhagens L3, L228-3, 521274, 521236 e 262841-1-4-1 foram avaliados sob epidemia natural em delineamento de blocos ao acaso e três repetições. Os cultivares foram plantados em fileiras de cinco metros, separadas por uma linha do híbrido resistente BRS1010. A cortina suscetível (fonte de inóculo) formada pelo híbrido DAS657, foi plantada na parte frontal de cada bloco, afastada 0,5 m. A severidade da doença foi avaliada em intervalos semanais a partir dos 60 dias do plantio, utilizando uma escala de 1 a 9, onde: 1= sem doença e 9= 100% de área foliar afetada. As avaliações foram realizadas em 6 pontos dentro da parcela afastados 1, 2, 3, 4, 5 e 6 metros da fonte de inóculo. Os dados de severidade foram usados para o calculo da área abaixo da curva de progresso da doença (AACPD), severidade da doença na metade da epidemia (Y50), severidade da doença no final da epidemia (Ymáx), e taxa de progresso da doença. Com inoculações em híbrido suscetível DAS657, em casa de vegetação, foi possível reproduzir os sintomas típicos da doença. Reisolamento a partir dessas lesões confirmou a presença da mesma bactéria isolada do campo, identificada como Pantoea ananatis, corroborando relatos do envolvimento desta bactéria nos sintomas iniciais da doença. Não foi observada a formação de um gradiente de dispersão baseado na severidade da doença observada em cada ponto de avaliação dentro da parcela. A melhor distinção entre os níveis de resistência de genótipos de milho foi obtida pelos valores de AACPD e Ymáx. Os híbridos de milho BRS1030, BRS1035 e BRS1010 e as linhagens L3, e L228-3 foram os genótipos mais resistentes. Essas linhagens podem ser usadas em programas de melhoramento visando resistência a mancha-branca.

Objectives: To determine whether treatment of demineralized enamel white spot lesions with CPP-ACP paste, CPP-ACFP paste or microabrasion technique decreases lesion depth in vitro. Additionally, to determine whether treatment of demineralized enamel white spot lesions with microabrasion technique in combination with CPP-ACP paste or CPP-ACFP paste decreases lesion depth greater than any of the three techniques alone. Background: White spot lesions (WSLs) after the removal of orthodontic appliances remain a problem for clinicians and patients. Previous studies suggest that application of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide amorphous calcium fluoride phosphate (CPP-ACFP) may promote enamel remineralization. Recently, microabrasion of enamel was proposed as another treatment modality of white spot lesions. A review of literature showed that there was no comprehensive in vitro study that combined microabrasion, casein phosphopeptide amorphous calcium phosphate and casein phosphopeptide amorphous calcium fluoride phosphate for treatment of WSLs. Methods: A total of one hundred and twelve bovine incisor teeth were randomly assigned to seven treatment groups: 1. Control 1 (demineralization control), 2. Control 2 (remineralization solution control), 3. CPP-ACP paste, 4. CPP-ACFP paste, 5. Microabrasion, 6. Microabrasion with CPP- ACP paste, and 7. Microabrasion with CPP-ACFP paste. Teeth in all groups were placed in demineralizing solution for 96 hours to produce artificial caries-like lesions. At the end of the 96 hr period, teeth in Control 1 group were sectioned to establish adequate amount of demineralization. The rest of samples were treated with assigned regimen once a day for 10 days and stored in remineralization solution. At the end of ten days, teeth were sectioned with a hard tissue microtome and observed under polarized microscopy to analyze enamel lesion depth. One-way ANOVA at α=0.05 was performed to assess difference in lesion depth between groups followed with post hoc Tukey's test. Results: Statistical analysis showed a significant difference between groups (pConclusions: Based on the results from this study, we can conclude that: (1) treatment of WSLs with CPP-ACP paste, CPP-ACFP paste or microabrasion decreases lesion depth in vitro; (2) microabrasion in combination with CPP-ACP paste or CPP-ACFP paste did not decrease lesion depth greater than that observed with either paste technique alone; (3) both CPP-ACP and CPP-ACFP pastes in combination with microabrasion treatments showed greater decrease in lesion depth than microabrasion alone.

AN INVESTIGATION OF SURFACE CHARACTERISTICS OF ENAMEL TREATED WITH INFILTRATIVE RESIN: A SCANNING ELECTRON MICROSCOPY STUDY Danielle E. Easterly, Doctorate of Dental Surgery. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University. 2017. Director: Dr. Eser Tüfekçi D.D.S., M.S., Ph.D., M.S.H.A. Objective: To evaluate the microstructural changes of a resin infiltrant (ICON®, DMG America LLC, Englewood, NJ) after six months of simulated toothbrushing. Materials and Methods: Ten extracted third molars (n=10) were collected. Artificial white spot lesions were created and resin applied. Environmental SEM images at 250X and 500X were taken after application of Icon® (T1), and after six months of simulated toothbrushing (T2). Micrographs were evaluated for changes in surface characteristics. Results: SEM showed some changes in the surface characteristics of the resin after simulated toothbrushing. However, changes in presence of enamel rods, microcracks, or fractures were not statistically significant (p>0.05). The effects of polymerization shrinkage were noted on most samples in the form of clefts and fissures. Conclusions: Icon® resin seems to withstand challenge by toothbrush abrasion over a six-month period, with some evidence of microstructural wear.

Three series of studies were conducted to quantify the effectiveness of dietary incorporation of b-1,3-glucan (BG) from Schizophyllum commune in enhancing the immunity and resistance of grass prawn Penaeus monodon to vibriosis and white spot syndrome virus (WSSV) infections. In the first series of studies, three experiments were conducted to evaluate the effectiveness of dietary b-1,3-glucan on shrimp growth and resistance to vibriosis. Weight gain, survival and feed efficiency of juvenile shrimp (0.5 ¡Ó 0.1 g) were not significantly different (P>0.05) after being fed the diets containing BG 0, 0.2, 2, 10 g/kg diet for 18 weeks. Subadult shrimp (20.4 ¡Ó 2.1 g) fed the diet containing of BG 2 g/kg diet for 10 days showed a significantly (P<0.001) enhanced resistance against vibriosis. Postlarvae fed with the BG diet (2 g/kg diet) were more resistant (P<0.001) against starvation and V. harveyi challenges than the postlarvae fed non-BG diet. Additive disease resistance was observed when polyphosphorylated L-ascorbic acid (PAA) was used together with BG. In challenge tests with V. damsela, shrimp fed with PAA (0.2 g/kg diet) + BG (2 g/kg diet) diet for 20 days had a survival rate up to 60%. In the second series of studies, two experiments were conducted to evaluate the effectiveness of dietary b-1,3-glucan on wound healing and immunity in spawners. Dietary supplement of BG reduced the chance of infections, but did not help wound healing as did the supplement of PAA. And regardless of indoor or outdoor rearing, the survival rate of brooder (135 ¡Ó 25 g) fed the BG (2 g/kg diet) diet was higher (P<0.001) than that of the non-BG group. Fed the BG brooders showed enhanced haemocyte phagocytic activity, cell adhesion and superoxide anion production then the control group. Third series of studies evaluated the effectiveness against white spot syndrome virus (WSSV). Six days after being challenged with WSSV, 12.2 % of the BG-treated (2 g/kg diet for 15 days) postlarvae (PL15) and 20 % BG-treated (2 g/kg diet for 20 days) juveniles (5.5 ¡Ó 0.5 g) were still alive; while all non-BG-treated shrimp died. In order to quantify the effectiveness of BG to WSSV, juveniles (6.5 ¡Ó 0.4 g) were fed diets containing graded levels of BG. The results showed that shrimp fed the diet containing BG 10 g/kg for 20 days had the highest (P<0.001) survival rate (42 %) among all groups. Shrimp that received diets supplemented with BG at a dosage >2 g/kg recuperated 9 ~ 12 days after WSSV challenge; while the group fed diets with no or 1 g/kg BG suffered from rapid decrease in total haemocyte count, phagocytic activity, phenoloxidase, O2-, superoxide dismutase (SOD) production and subsequent high mortality. The results in this study showed that b-1,3-glucan is effective in enhancing the phagocytic activity, phenoloxidase, O2- and SOD productions and consequently the resistance of postlarval, juvenile, subadult and brooder P. monodon against vibriosis and viral infections. Since prolonged use of BG, even at optimal dietary levels, decreased the immunity of the shrimp, care therefore must be taken to maximize its effectiveness. A cycle of dietary BG supplement of 2 ~ 10 g/kg diet for 20 days with an intermission of 10 days may serve the purposes.

No description available.

Les taches blanches sont liées à l'hypominéralisation sous la surface de l'émail et sont la 1ère étape du développement de la carie dentaire. La détection précoce des caries dentaires naissantes avant qu'elles n'atteignent le stade de la cavitation offre une opportunité pour des soins dentaires efficaces. Pour réaliser les objectifs de cette étude qui sont de renforcer l'idiome des soins minimalement invasifs, nous avons identifié un modèle de cycle de pH modifié qui permet d’imiter les conditions intra-buccales qui conduisent à la formation de lésions de type tache blanche, dans un court laps de temps. Des techniques optiques non invasives, comme la microscopie Raman confocale et la microscopie multiphotonique, ont été utilisées dans cette étude pour détecter de petits changements dans la composition chimique de l'émail in vitro.De plus, la technique de nano-indentation a été appliquée pour étudier les changements dans les propriétés mécaniques de l'émail et les relier à ceux affectant sa composition chimique après l'induction des caries, afin d‘ajouter de la spécificité chimique-mécanique aux informations sur les lésions sous-surface de l'émail. Les résultats obtenus démontrent un grand potentiel pour les techniques examinées, fournissant une base pour des applications intéressantes dans le diagnostic clinique de différentes pathologies dentaires. Pour résoudre le problème du traitement des lésions primitives sans intervention chirurgicale, l'efficacité de la crème GC Tooth Mousse et du dentifrice contenant de la nano-hydroxyapatite «KAREX» dans l'amélioration de la reminéralisation de l'émail déminéralisé par la localisation du phosphate de calcium amorphe à la surface de la dent a été inspectée. L'étude a indiqué le manque de preuves fiables soutenant l'efficacité des agents reminéralisants dans le traitement des taches blanches. Ce travail doit être poursuivi par d'autres études in-vitro et par des études cliniques. / White spot lesion is the subsurface hypomineralization of enamel indicating the 1st stage of dental caries development. Early detection of incipient dental caries before it reaches the stage of cavitation offers an opportunity for effective dental care. The objectives of this study were to strengthen the idiom of minimally invasive treatment. In order to achieve the specified goals; we have identified a modified pH cycling model that can mimic the intraoral conditions leading to white spot lesions formation in a short time. In addition, non-invasive optical techniques, such as confocal Raman microscopy and multiphoton microscopy were used in this study to detect small changes in the enamel chemical composition in vitro.Furthermore, nano-indentation technique was used to detect the changes in the mechanical properties of enamel and relate them to those affecting its chemical composition after caries induction in order to add chemico-mechanical specificity in providing important information about subsurface lesions in enamel. The obtained results demonstrate a great potential for the examined techniques, providing a basis for interesting applications in the clinical diagnosis of various pathological conditions in dentistry. To treatment the incipient carious lesions non-invasively, the effectiveness of GC Tooth Mousse cream and nHA containing-dentifrice "KAREX" in the remineralization of demineralized enamel through localizing amorphous calcium phosphate at tooth surface has been inspected. The study indicated a lack of reliable evidence supporting the efficacy of remineralizing agents in the treatment of white spot lesions. Within the limitations of this study, further laboratory studies together with clinical research are therefore required to increase the available knowledge on this prevalent subject.