Intentional creation of carbon-rich dark earth soils in the Amazon.

Fertile soil known as Amazonian dark earth is central to the debate over the size and ecological impact of ancient human populations in the Amazon. Dark earth is typically associated with human occupation, but it is uncertain whether it was created intentionally. Dark earth may also be a substantial carbon sink, but its spatial extent and carbon inventory are unknown. We demonstrate spatial and compositional similarities between ancient and modern dark earth and document modern Indigenous practices that enrich soil, which we use to propose a model for the formation of ancient dark earth. This comparison suggests that ancient Amazonians managed soil to improve fertility and increase crop productivity. These practices also sequestered and stored carbon in the soil for centuries, and we show that some ancient sites contain as much carbon as the above-ground rainforest biomass. Our results demonstrate the intentional creation of dark earth and highlight the value of Indigenous knowledge for sustainable rainforest management.

Are salivary flow rates associated with histopathologic aspects in patients with rheumatoid arthritis?

The aim of this retrospective cross-sectional study was to verify the association between salivary flow rates (SFR) and the histopathologic aspects of labial salivary glands (LSG) in patients with rheumatoid arthritis (RA). Patients presenting rheumatologic diseases referred for oral evaluation were included in the study if they had RA and had SFR measured and LSG biopsy performed. Patients were excluded if they had systemic conditions that affect SFR or if they were being treated for hyposalivation. Cases without enough material for histopathologic analysis were also excluded. Data were collected through questionnaires, oral examination, resting and stimulated SFR, and LSG biopsies. A histopathologic reevaluation was carried out in order to seek for additional histopathologic aspects. Fifty-one patients met the inclusion criteria. The mean age was 53.5 years (25-77), and 94.1% were women. The median resting and stimulated SFRs were 0.24 mL/min and 1.02 mL/min, respectively. The presence of lymphocytic focus and fibrosis were significantly associated with stimulated SFR, but not with resting SFR. The odds ratio of patients who had hyposalivation for presenting a positive lymphocytic focus was 7.33 (confidence interval CI: 1.53-35.23) by the stimulated technique, and 2.56 (CI: 0.57-11.40) in resting SFR. In the medical records, 14 (31.80%) patients had been diagnosed with secondary Sjögren's syndrome. In conclusion, stimulated SFR represent a good screening test to predict lymphocytic focus in LSG in patients with RA, which represents the most specific test to diagnose Sjögren's syndrome.

Oral health status of patients with multiple myeloma.

OBJECTIVE: To describe the oral health status of patients with multiple myeloma and compare to a control group. MATERIALS AND METHODS: The medical history of the studied subjects was obtained from the medical records and through interviews. Trained examiners evaluated the oral mucosa, teeth, periodontium and imaging aspects. The dental status was evaluated by the decayed, missing and filled teeth index. The presence of bone lesions was investigated with cone beam computer tomography images of the jaws. RESULTS: The most common oral mucosa features were paleness (31%) and coated tongue (14.3%) in the multiple myeloma group (N=42); and coated (21.4%) and fissured tongue (10.7%) in the control group (N=28). The mean DMFT index of patients with multiple myeloma was high, but not significantly different from controls (14.57 versus 19.69, p=0.975). Hypodense lesions suggestive of multiple myeloma were observed in the jaws of 73.8% of the patients. Hypodense lesions related to teeth were detected in 33.3% of the patients and in 53.6% of the controls (p=0.832). CONCLUSIONS: The studied population of multiple myeloma patients presented many oral health issues that needed attention. Thus, oral care should be included in the routine treatment to improve the quality of the oral status in these patients.

Are salivary flow rates associated with histopathologic aspects in patients with rheumatoid arthritis?

Abstract The aim of this retrospective cross-sectional study was to verify the association between salivary flow rates (SFR) and the histopathologic aspects of labial salivary glands (LSG) in patients with rheumatoid arthritis (RA). Patients presenting rheumatologic diseases referred for oral evaluation were included in the study if they had RA and had SFR measured and LSG biopsy performed. Patients were excluded if they had systemic conditions that affect SFR or if they were being treated for hyposalivation. Cases without enough material for histopathologic analysis were also excluded. Data were collected through questionnaires, oral examination, resting and stimulated SFR, and LSG biopsies. A histopathologic reevaluation was carried out in order to seek for additional histopathologic aspects. Fifty-one patients met the inclusion criteria. The mean age was 53.5 years (25-77), and 94.1% were women. The median resting and stimulated SFRs were 0.24 mL/min and 1.02 mL/min, respectively. The presence of lymphocytic focus and fibrosis were significantly associated with stimulated SFR, but not with resting SFR. The odds ratio of patients who had hyposalivation for presenting a positive lymphocytic focus was 7.33 (confidence interval CI: 1.53-35.23) by the stimulated technique, and 2.56 (CI: 0.57-11.40) in resting SFR. In the medical records, 14 (31.80%) patients had been diagnosed with secondary Sjögren's syndrome. In conclusion, stimulated SFR represent a good screening test to predict lymphocytic focus in LSG in patients with RA, which represents the most specific test to diagnose Sjögren's syndrome.

Surface modification of gutta-percha cones by non-thermal plasma.

This study was designed to evaluate the effects of Oxygen and Argon plasma on gutta-percha surfaces. A total of 185 flat smooth gutta-percha surfaces were used. Samples were divided into groups: control: no plasma treatment; Oxygen: treatment with Oxygen plasma for 1min; Argon: treatment with Argon plasma for 1min. Samples were evaluated topographically by scanning electron microscopy and atomic force microscopy; and chemically by Fourier Transform-infrared Spectroscopy. A goniometer was used to determine the surface free energy and the wettability of the endodontic sealers. Additionally 60 bovine teeth were filled using pellets of gutta-percha (control, oxygen and argon plasma) and the sealers. Teeth were evaluated by push-out and microleakage tests. Data were statistically analyzed using specific tests. Argon plasma did not change the surface topography, while Oxygen plasma led to changes. Both treatments chemically modified the gutta-percha surface. Argon and Oxygen plasma increased the surface free energy and favored the wettability of AH Plus and Pulp Canal Sealer EWT. Regarding bond strength analysis, for AH Plus sealer, both plasma treatments on gutta-percha favored the bond strength to dentin. However, for Pulp Canal Sealer, there is no statistically significant influence. For leakage test, dye penetration occurred between sealer and dentin in all groups. In conclusion, Oxygen plasma led to both topographic and chemical changes in the gutta-percha surface, while Argon plasma caused only chemical changes. Both treatments increased the surface free energy, favoring the wettability of AH Plus and Pulp Canal Sealer EWT sealers and influenced positively in the adhesion and leakage.

Effect of Argon Plasma on Root Dentin after Use of 6% NaOCl.

UNLABELLED: The aim of this study was to evaluate the effect of argon plasma on dentin surface after use of 6% NaOCl. Sixty bovine incisors had their crowns removed, the roots split, and the segments planed. One hundred twenty segments of the cervical third were used. The samples were divided in two groups (n=60): CONTROL GROUP: immersed in 6% NaOCl, washed, dried and then immersed in 17% EDTA, washed and dried and Argon group: after treatment described for the CONTROL GROUP, non-thermal argon plasma was applied for 30 s. Ten samples were evaluated by scanning electron microscopy in each group. Other ten samples were analyzed by Fourier transform infrared spectroscopy (FTIR). Thirty samples were analyzed with a goniometer to measure the contact angle between the dentin surfaces and solutions, to determine the surface free energy. The last ten samples were used to evaluate the wettability of AH Plus sealer. Data were statistically analyzed using Kruskal Wallis and Mann-Whitney tests (p<0.05). The results of this study showed that argon plasma did not modify the surface topography. FTIR analysis showed chemical modifications after plasma treatment. Argon plasma increased the surface free energy of dentin and AH Plus wettability. In conclusion, argon plasma treatment modified chemically the dentin surface. This treatment increased the surface free energy and wettability of an epoxy resin root canal sealer, favoring its bonding to dentin surfaces.

EVALUATION OF THE THERAPEUTIC EFFICACY OF LEVAMISOLE HYDROCHLORIDE ON THIRD-STAGE LARVAE OF Lagochilascaris minor IN EXPERIMENTALLY INFECTED MICE.

Lagochilascariosis, a disease caused by Lagochilascaris minor, affects the neck, sinuses, tonsils, lungs, the sacral region, dental alveoli, eyeballs and the central nervous system of humans. A cycle of autoinfection may occur in human host tissues characterized by the presence of eggs, larvae and adult worms. This peculiarity of the cycle hinders therapy, since there are no drugs that exhibit ovicidal, larvicidal and vermicidal activity. Given these facts, we studied the action of levamisole hydrochloride on third-stage larvae in the migration phase (G1) and on encysted larvae (G3) of L. minor. To this end, 87 inbred mice of the C57BL/6 strain were divided into test groups comprising 67 animals (G1-37; G3-30) and a control group (G2-10; G4-10) with 20 animals. Each animal was inoculated orally with 2,000 infective eggs of the parasite. The animals of the test groups were treated individually with a single oral dose of levamisole hydrochloride at a concentration of 0.075 mg. The drug was administered either 30 minutes prior to the parasite inoculation (G1 animals) or 120 days after the inoculation (G3 animals). The mice in the control groups were not treated with the drug. After the time required for the migration and the encysting of L. minor larvae, all the animals were euthanized and their tissues examined. The data were analyzed using the Student's unpaired t-test and the Levene test. The groups showed no statistically significant difference. Levamisole hydrochloride was ineffective on third-stage larvae of L. minor. These findings explain the massive expulsion of live adult worms, as well as the use of long treatment schemes, owing to the persistence of larvae and eggs in human parasitic lesions.

Oral health status of patients with multiple myeloma

ABSTRACT Objective: To describe the oral health status of patients with multiple myeloma and compare to a control group. Materials and methods: The medical history of the studied subjects was obtained from the medical records and through interviews. Trained examiners evaluated the oral mucosa, teeth, periodontium and imaging aspects. The dental status was evaluated by the decayed, missing and filled teeth index. The presence of bone lesions was investigated with cone beam computer tomography images of the jaws. Results: The most common oral mucosa features were paleness (31%) and coated tongue (14.3%) in the multiple myeloma group (N = 42); and coated (21.4%) and fissured tongue (10.7%) in the control group (N = 28). The mean DMFT index of patients with multiple myeloma was high, but not significantly different from controls (14.57 versus 19.69, p = 0.975). Hypodense lesions suggestive of multiple myeloma were observed in the jaws of 73.8% of the patients. Hypodense lesions related to teeth were detected in 33.3% of the patients and in 53.6% of the controls (p = 0.832). Conclusions: The studied population of multiple myeloma patients presented many oral health issues that needed attention. Thus, oral care should be included in the routine treatment to improve the quality of the oral status in these patients.

Effect of Argon Plasma on Root Dentin after Use of 6% NaOCl

Abstract The aim of this study was to evaluate the effect of argon plasma on dentin surface after use of 6% NaOCl. Sixty bovine incisors had their crowns removed, the roots split, and the segments planed. One hundred twenty segments of the cervical third were used. The samples were divided in two groups (n=60): Control group: immersed in 6% NaOCl, washed, dried and then immersed in 17% EDTA, washed and dried and Argon group: after treatment described for the Control group, non-thermal argon plasma was applied for 30 s. Ten samples were evaluated by scanning electron microscopy in each group. Other ten samples were analyzed by Fourier transform infrared spectroscopy (FTIR). Thirty samples were analyzed with a goniometer to measure the contact angle between the dentin surfaces and solutions, to determine the surface free energy. The last ten samples were used to evaluate the wettability of AH Plus sealer. Data were statistically analyzed using Kruskal Wallis and Mann-Whitney tests (p<0.05). The results of this study showed that argon plasma did not modify the surface topography. FTIR analysis showed chemical modifications after plasma treatment. Argon plasma increased the surface free energy of dentin and AH Plus wettability. In conclusion, argon plasma treatment modified chemically the dentin surface. This treatment increased the surface free energy and wettability of an epoxy resin root canal sealer, favoring its bonding to dentin surfaces.

Resumo O objetivo do presente estudo foi avaliar o efeito do plasma de argônio na superfície dentinária após o uso de NaOCl 6%. As coroas de 60 incisivos bovinos foram removidas, as raízes clivadas e os segmentos planificados. Cento e vinte segmentos referentes ao terço cervical foram utilizados. As amostras foram divididas em dois grupos (n=60): Grupo Controle: imersos em NaOCl 6%, lavados, secos, imersos em EDTA 17%, lavados e secos e Grupo Argônio: após o tratamento descrito no grupo controle, foi aplicado plasma de argônio não térmico por 30 s. Em cada grupo, 10 amostras foram avaliadas por microscopia eletrônica de varredura. Outras dez amostras foram analisadas por espectroscopia no infravermelho por transformada de Fourier (FTIR). Trinta amostras foram analisadas com um goniômetro para medir o ângulo de contato entre a superfície dentinária e as soluções e determinar a energia livre de superfície. As últimas dez amostras foram utilizadas para avaliar a molhabilidade do cimento AH Plus. Os dados foram analisados estatisticamente usando os testes de Kruskal Wallis e Mann-Whitney (p<0,05). Os resultados do estudo mostraram que o plasma de argônio não modificou a topografia de superfície. A análise por FTIR mostrou modificações químicas após o tratamento de plasma. O plasma de argônio aumentou a energia livre da superfície dentinária e a molhabilidade do cimento AH Plus. Conclusão, o tratamento com plasma de argônio modificou quimicamente a superfície dentinária. Este tratamento aumentou a energia livre de superfície e a molhabilidade de um cimento endodôntico à base de resina epóxi, favorecendo as características adesivas da superfície dentinária.

Efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl / Effect of oxygen plasma on dentin exposed to NaOCl

Introdução: O tratamento de plasma é uma tecnologia eficaz que pode manter as propriedades internas dos materiais inalteradas após o tratamento, modificando apenas a superfície. Objetivo: Avaliar o efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl 6%. Material e método: Foram utilizados 60 incisivos bovinos. A coroa foi removida, a raiz foi dividida e as faces planificadas, totalizando 120 segmentos referentes ao terço cervical. As amostras foram divididas em dois grupos: controle (imersa em NaOCl 6%, lavada com água destilada, seca, imersa em EDTA 17%, lavada e seca) e plasma de oxigênio (após tratamento descrito no grupo controle, plasma de oxigênio foi aplicado por 30 s). As amostras foram avaliadas qualitativamente em relação à topografia por microscopia eletrônica de varredura, utilizando-se microfotografias com ampliação de 1.000×. O goniômetro Ramé-hart foi utilizado para a mensuração do ângulo de contato entre as superfícies e as seguintes soluções foram utilizadas: água, etilenoglicol e di-iodometano. Em seguida, a energia de superfície, representada pelas componentes polar e dispersiva, foi calculada. Avaliou-se também o escoamento dos cimentos Pulp Canal Sealer EWT (PCS) e Real Sal SE (RS) na superfície dentinária. Os dados foram analisados estatisticamente utilizando os testes Kruskal-Wallis e Mann-Whitney U (p<0,05). Resultado: O tratamento com plasma levou à formação de uma camada semelhante à smear layer na superfície dentinária. Este tratamento levou a um aumento da energia de superfície e da componente polar, favorecendo a hidrofilicidade da superfície. Entretanto, desfavoreceu o escoamento do cimento PCS e não influenciou no escoamento do cimento RS. Conclusão: O plasma de oxigênio ocasionou mudanças topográficas na superfície dentinária, favorecendo a hidrofilicidade desta. Contudo, não favoreceu o escoamento dos cimentos endodônticos na dentina.

Introduction: Plasma treatment is an effective technology since the internal properties of the material is kept unchanged after treatment, modifying only the surface. Objective: To evaluate the effect of oxygen plasma on dentin previously exposed to 6% NaOCl. Material and method: 60 bovine incisors were used. The crown was removed, the root splited and the faces planned amounting 120 segments related to the cervical third. The samples were divided into 2 groups, control (immersed in 6% NaOCl, washed with distilled water, dried, immersed in 17% EDTA, washed and dried) and oxygen plasma (after treatment described in the control group, oxygen plasma was applied for 30s). The samples were evaluated qualitatively in relation to topography by scanning electron microscopy using photomicrographs at 1000× of magnification. The Ramé-hart goniometer was used to measure the contact angle between the surfaces and the following solutions: water, ethyleneglycol, and diiodomethane. Then, surface energy, polar and dispersive components, was calculated. Additionally, it was evaluated the flow of Pulp Canal Sealer EWT (PCS) and Real Salt SE (RS) sealers on dentin surface. Data were statistically analyzed using Kruskal-Wallis e Mann-Whitney U (p<0.05). Result: Plasma treatment caused topographical changes on dentin surface. This treatment led to an increase in surface energy and polar component, favoring the hydrophilicity of the surface. However, it disfavors the wettability of PCS and did not influence the RS wettability. Conclusion: The oxygen plasma caused topographical changes on dentin surface, favoring its hydrophilicity. However, it did not favor the sealers wettability on dentin.

Evaluation of the risk of a stripping perforation with Gates-Glidden drills: serial versus crown-down sequences.

The aim of this study was to evaluate the remaining dentine/cementum thickness using Gates-Glidden burs in serial and crown-down sequences and to observe which of the two sequences is the safest for preparing mesial roots of molars. Thirty-six left and right human mandibular first molars were selected. Standard access cavities were made and initially explored with Flexofiles sizes 10 and 15 until the tip was visible at the apex. The teeth were embedded in a muffle specially developed for this study using a PVC tube with two parallel metal rods in its lid. Each tooth-block was sectioned 3 mm apically to the furcation using a low-speed saw with a diamond disc. The tooth-block was examined under a microscope and an initial image was captured by a digital video system with 8 X and 12 X magnifications. Finally, the tooth-blocks were reassembled in the muffle so that the canals could be instrumented. After instrumentation the area of each mesial canal as well as the smallest distance to the root furcation were measured again. The mesio-buccal canals (crown-down order) and the mesio-lingual canals (serial sequence) presented an average area of 0.46 +/- 0.16 mm(2) and 0.88 +/- 0.27 mm(2) (P < 0.01), respectively. The mean values of the smallest distance to the furcation for the mesio-buccal and mesio-lingual canals were 0.66 +/- 0.19 mm and 0.39 +/- 0.13 mm (P < 0.01), respectively. The remaining dentine/cementum thickness using Gates-Glidden burs was greater in the crown-down sequence than in the serial sequence.

Effectiveness of an electronic apex locator used after preflaring of cervical and middle third

Introduction: The electronic method has been studied and improved aiming to add precision, speed and reliability of the measurement technique to determine the exact location of the working length. Currently, the root canal preparation recommends prior to determine the tooth length and consequent perform instrumentation of the apical portion, a previous preflaring of the cervical and middle thirds in various techniques. This procedure may provide a reduction in system impedance, leading to read errors by the apex locators. Objective: Investigate the influence of preflaring of the cervical and middle thirds on the accuracy of measuring the working length by apex locators. Material and methods: Twenty-five mesial roots of molars were used and had their crowns cut at the cemento-enamel junction. The actual measure of each root canal was performed and then the samples were embedded into a mixture of alginate, used as a conducting medium, where electronic measurements were taken with apex locator before and after preflaring of the canals with Gates-Glidden drills in descending order (#4, #3, #2). Measurements obtained by electronic method were then compared with the actual measurement of the root canal. The results were tabulated and submitted to the Student t test. Results: The results show that there was no statistical significance (p<0.05) between the readings before and after preflaring. Readings closer to the foraminal ending occurred in the group after preflaring with Gates Glidden. Conclusion: It was concluded that preflaring with Gates Glidden drills were not able to influence significantly the accuracy of apex locator in determining the exact working length.

Evaluation of the risk of a stripping perforation with gates-glidden drills: serial versus crown-down sequences

The aim of this study was to evaluate the remaining dentine/cementum thickness using Gates-Glidden burs in serial and crown-down sequences and to observe which of the two sequences is the safest for preparing mesial roots of molars. Thirty-six left and right human mandibular first molars were selected. Standard access cavities were made and initially explored with Flexofiles sizes 10 and 15 until the tip was visible at the apex. The teeth were embedded in a muffle specially developed for this study using a PVC tube with two parallel metal rods in its lid. Each tooth-block was sectioned 3 mm apically to the furcation using a low-speed saw with a diamond disc. The tooth-block was examined under a microscope and an initial image was captured by a digital video system with 8 X and 12 X magnifications. Finally, the tooth-blocks were reassembled in the muffle so that the canals could be instrumented. After instrumentation the area of each mesial canal as well as the smallest distance to the root furcation were measured again. The mesio-buccal canals (crown-down order) and the mesio-lingual canals (serial sequence) presented an average area of 0.46 ± 0.16 mm² and 0.88 ± 0.27 mm² (P < 0.01), respectively. The mean values of the smallest distance to the furcation for the mesio-buccal and mesio-lingual canals were 0.66 ± 0.19 mm and 0.39 ± 0.13 mm (P < 0.01), respectively. The remaining dentine/cementum thickness using Gates-Glidden burs was greater in the crown-down sequence than in the serial sequence.

Assessment of ivermectin therapeutic efficacy on third-stage larvae of Lagochilascaris minor in mice experimentally infected

Avaliou-se a acao da ivermectina sobre larvas de terceiro estadio, tanto em fase de migracao, quanto larvas encistadas em tecidos de camundongos infectados experimentalmente com Lagochilascaris minor. Foram utilizados 120 camundongos (grupos I e II), sendo que cada animal foi inoculado, por via oral, com 1.000 ovos do parasito. Para verificar a acao da ivermectina sobre larvas em migracao, o grupo I (60 animais) foi dividido igualmente em tres subgrupos: I-A, I-B e I-C. No setimo dia apos a inoculacao (DAI), cada animal foi tratado com ivermectina na dosagem de 200 ug/Kg (subgrupo I-A) e 1.000 ug/Kg/dose unica/via sc (subgrupo I-B). Com o objetivo de verificar a acao das drogas sobre larvas encistadas, os animais do grupo II foram divididos igualmente em tres subgrupos: II-A, II-B e II-C...

Relato de caso de Lagochilascariose humana procedente do Estado do Pará, Brasil / Report a case of human lagochilascariasis coming from the Pará, Brazil

Mais um caso de lagochilascariose em criança procedente do Município de Xinguara PA. No Hospital das Clínicas da UFG, foi feita drenagem do abscesso localizado na regiäo cervical direita, constatando-se a presença de ovos e vermes adultos de Lagochilascaris minor. Instituída terapia com albendazol 400mg/dia (durante 30 dias) e antibioticoterapia, houve regressäo do quadro clínico

Gato doméstico (Felis catus domesticus) como possível reservatório de Lagochilascaris minor Leiper (1909) / Domestic cat (Felis catus domesticus) as a possible reservoir of Lagochilascaris minor Leiper, 1909

A lagoquilascaríase é uma zoonose e acredita-se que felídeos silvestres sejam hospedeiros definitivos de Lagochilascaris minor. Além do homem, há relatos de infecção natural por L. minor em cães e gatos domésticos. Com o objetivo de avaliar o comportamento de Felis catus domesticus como possível reservatório de L. minor, 20 gatos foram inoculados individualmente com 50 larvas de terceiro estádio de L. minor, obtidas de camundongos experimentalmente infectados. A avaliação da infecção foi feita durante 180 dias, por meio de exames clínicos e coproscópicos, tendo sido finalizada com a necropsia dos animais. Os resultados demonstraram 100por cento de infectividade. Entre os animais pesquisados, 15 apresentaram exame parasitológico de fezes positivo a partir do 15º dia após a infecção e mantiveram-se eliminando ovos do parasito até o final do experimento. Os outros animais (5) apresentaram exames coproscópicos negativos e a infecção foi diagnosticada pela presença de lesões contendo o parasito. Considera-se, portanto, a possibilidade de o gato doméstico atuar como reservatório de L. minor na natureza e merece destaque a semelhança do padrão de infecção no gato doméstico e no homem.

Análise quantitativa in vitro da obturação de canais laterais / Quantitative in vitro analysis of the filling of lateral canals

O objetivo deste trabalho foi analisar a capacidade de penetração de guta-percha e cimento nos canais laterais simulados em blocos de resina acrílica realizados com o auxílio de uma microbiota cilíndrica de 0,2 mm de diâmetro. Os canais foram obturados utilizando duas técnicas de obturação: técnica de compactação vertical de Schilder modificada utilizando o Sistema Obtura II e técnica híbrida de Tagger. A técnica utilizando o Sistema Obtura II promoveu maior preechimento de guta-percha nos três terços, enquanto que a técnica híbrida de Tagger promoveu maior preenchimento de cimento nos canais laterais cervicais e mediais

Estudo da infectividade e inunogenicidade da cepa y de Trypanosoma cruzi, mantida por longo período em meio de cultura / Immunogenicity and infectivity of T. cruzi Y strain, maintened in to culture medium for lon time

Verificou-se que a "Cepa Ym"de Trypanosoma cruzi, mantida por mais de 20 anos em meio de cultura (LIT), tornou-se näo infectante comprovado ao observar-se ausência de parasitemia pelo exame direto, ausência de mortalidade, negatividade do xenodiagnóstico, além do estudo histopatológico näo demonstrar qualquer evidência de processo inflamatório em camundongos inoculados com 10.000.000 epimastigotas/ml por via subcutânea. Este mesmo inóculo mais o reforço com 30 dias, foi capaz de proteger parcialmente camundongos näo isogênicos contra o desafio com "Cepa Y" de T. cruzi na dose de 10.000 tripomastigotas/ml por via intraperitoneal, revelado por ausência de parasitemia pelo exame direto, ausência de mortalidade, positividade do xenodiagnóstico realizado 30 dias após o desafio em somente 15 pôr cento dos triatomíneos na leitura de 90 dias, apesar do estudo histopatológico revelar processo inflamatório de moderado a acentuado sobretudo na musculatura esquelética. Enquanto que o grupo de camundongos que só receberam o inóculo desafiante "Cepa Y", revelou parasitemia da ordem de 100.000 tripomastigotas/ml pelo exame direto, índice de mortalidade de 30 pôr, positividade do xenodiagnóstico em 100 pôr cento dos triatomíneos e processo inflamatório acentuado na musculatura esquelética e moderado no miocárdio. A contra-prova da proteçäo foi verificada nos camundongos que tiveram a resposta imune induzida pela "Cepa Ym" suprimida por irradiaçäo gama (700 rads/13 minutos) ou esplenectomia 20 dias após o desafio com a " Cepa Y", traduzido por elevaçäo da parasitemia pelo exame direto e positividade do xenodiagnóstico em torno de 70 pôr cento dos triatomíneos, já na leitura de 30 dias

Estudo da infectividade da Cepa "Y" de Trypanosoma cruzi, mantida por longo período em meio de cultura, após passagem em triatomíneos / Study of the infectinity of the \"Y\" strain of T. cruzi maintenedal in culture, after passage in triatomines

A cepa "Y" de Trypanosoma cruzi, mantida por mais de vinte anos em meio de cultura (LIT) em nosso laboratório, tornou-se näo virulenta para hospedeiros sensíveis (0,1ml/1x10 (10) tripanossomas/ml,via intraperitoneal/camundongos Balb-C). Com a finalidade de se verificar uma possível alteraçäo da infectividade desta cepa após passagem em triatomíneos, foi feito xenodiagnóstico artificial, quando se utilizou 25 triatomíneos da espécies Dipetalogaster maximus (1§ estágio), 25 triatomas matogrossensis (4§ e 5§ estagio) e 20 Rhodnius negletus (5§ estagio), os quais se alimentaram no aparelho de xenodiagnóstico contendo 20 ml de meio LIT com 1,5 x 10 (10) tripanossomas/ml da cepa "Y" mais 10,l de sangue humano heparinizado. A primeira leitura, feita com 30 dias, foi positiva em 40 pôr cento dos triatomíneos, enquanto que, com 60 dias, a positividade foi de 95 pôr cento dos triatomíneos. Nessa ocasiäo foi feito um "pool" de fezes e urina de todos os triamoníneos, obtendo-se um volume de 8ml de material contendo 1,1 x 10 (7) formas/ml, cuja concentraçäo foi inoculada, volume de 0,4ml, por via intraperitonial, em 20 camundongos da linha Balbi- C. Animais do grupo controle também receberam inóculo do mesmo volume, concentraçäo e via, da cepa "Y" proveniente de meio de cultura (LIT). Ambos os grupos de camundongos obtiveram os mesmos resultados, onde a parisitemia verificada por 30 dias após o inóculo, permaneceu negativa, näo houve mortalidade dentro do período de 120 dias e o estudo anatomopatólogico (coraçäo, baço, fígado, musculatura do quadríceps) realizado com 30 e 120 dias, após, näo revelou a presença de amastigotas e nem processo inflamatório em nenhum dos órgäos. Concluindo que näo houve alteraçäo da infectividade desta cepa após uma passagem em triatomíneos

Avaliaçäo da eficácia do albendazol na lagochilascaríase murina experimental / Evaluation of the efficacy of albendazol in the murine experimental lagochilascariasis

Para avaliar a açäo do albendazol sobre larvas de terceiro estágio de Lagochilascaris minor foram empregados 60 camundongos isogênicos C57BL/6, divideos em três grupos iguais. Cada animal foi inoculado com 10ü ovos infectantes de L. minor, via oral, através de uma sonda esofagiana. Todos os animais dos Grupos I e II foram tratados individualmente com albendazol, na dosagem de 400 mg/Kg/dia, via oral, durante 30 dias. Tendo em vista o padräo de migraçäo de larvas de L. minor no organismo de camundongo (hospedeiro intermediário), os animais do Grupo I receberam a droga a partir do 7º dia e os do Grupo II, no 60º dia após o término do uso da droga, todos os animais de cada grupo foram necropsiados. O número de larvas vivas recuperadas dos nódulos da musculatura esquelética do tecido celular subcutâneo e das vísceras foi o critério utilizado para avaliar a eficácia da droga. Foram observados níveis de eficácia de 80,9(pôr cento) para o Grupo I e de 66,3 (pôr cento) para o Grupo II. Podemos inferir que ambos os esquemas terapêuticos utilizados neste trabalho foram ineficazes no tratamento da lagochilascaríase murina experimental