Academic literature on the topic 'Anthelmintic agents'

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-03T13:51:17Z No. of bitstreams: 1 elisabethcamposdeandrade.pdf: 1614173 bytes, checksum: 02bbfb073bbecc90f3e7f67d2c386c90 (MD5)<br>Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-03T19:01:36Z (GMT) No. of bitstreams: 1 elisabethcamposdeandrade.pdf: 1614173 bytes, checksum: 02bbfb073bbecc90f3e7f67d2c386c90 (MD5)<br>Made available in DSpace on 2017-04-03T19:01:36Z (GMT). No. of bitstreams: 1 elisabethcamposdeandrade.pdf: 1614173 bytes, checksum: 02bbfb073bbecc90f3e7f67d2c386c90 (MD5) Previous issue date: 2009-03-26<br>FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais<br>As parasitoses intestinais são um importante problema de saúde pública principalmente nos países subdesenvolvidos ou em desenvolvimento. Embora o parasitismo intestinal seja amplamente reconhecido como relevante no contexto epidemiológico de diversas comunidades, os estudos sobre o assunto são ainda insuficientes, principalmente no Brasil. Em vista da dificuldade de diagnóstico específico das parasitoses, muitas vezes são realizados tratamentos empíricos com mais de uma droga. O objetivo principal do presente estudo foi avaliar a efetividade e segurança do uso de nitazoxanida no tratamento de poliparasitoses comparado à terapêutica tradicional ofertada pelo serviço público. Além deste objetivo, foi possível investigar a prevalência e os fatores associados às parasitoses intestinais na população de Colônia do Paiol, uma comunidade quilombola, na Zona da Mata, Minas Gerais. Na comunidade analisada, procedeuse um estudo transversal por censo, sendo que dos 425 moradores, 391 (92%) foram avaliados através de questionário estruturado e exame coproparasitológico. Os resultados mostraram uma alta positividade (63,8%), sendo as espécies patogênicas mais freqüentes Ascaris lumbricoides (22,4%) e Trichuris trichiura (17,9%). O poliparasitismo ocorreu em 36,5% dos investigados. O ensaio clínico, controlado, duplo cego, randomizado avaliou 65 indivíduos em dois grupos de tratamento. A taxa de cura foi de 32,4% e 38,7% com a nitazoxanida e com o tratamento convencional, respectivamente, mas esta diferença não foi estatisticamente significativa (p=0,599). A ocorrência de vômito (p= 0,031) esteve associada ao tratamento convencional e de urina esverdeada ao uso de nitazoxanida (p=0,002). Os outros efeitos adversos foram independentes da droga. Houve diferença estatisticamente significativa em relação à cor da pele e a taxa de cura para ambos os tratamentos. A menor eficácia efetividade foi apresentada pelos indivíduos de cor preta. São necessários outros estudos para esclarecer a baixa efetividade nos casos de poliparasitismo, assim como, reavaliar as práticas preventivas e terapêuticas, com o uso de novas drogas e de agentes de largo espectro, podendo a nitazoxanida ser uma droga alternativa neste contexto. Agrega-se às novas possibilidades terapêuticas, a necessidade de políticas públicas que garantam qualidade de vida, através de saneamento básico, educação para saúde e acesso ao sistema público de saúde, minimizando as iniqüidades na sociedade.<br>Intestinal parasitism is an important public health concern, chiefly in underdeveloped or developing countries. Although widely recognized as a relevant community epidemiological issue, intestinal parasitism has not been sufficiently studied in Brazil. Because specific diagnosis is difficult and generally cumbersome, empiric treatment, sometimes with more than one drug, is frequently employed. The main aim of this study was the assessment of the effectiveness and safety of nitazoxanide for the treatment of intestinal polyparasitism, as compared to traditional therapy provided by the public service. The study also investigated the prevalence of and factors associated with intestinal parasitism in the population of Colônia do Paiol, a quilombola community from the Zona da Mata, Minas Gerais, Brazil. A census-based cross-sectional study used a structured questionnaire and stool examination to assess 391 people (92%) of the 425 inhabitants of the community. The frequency of intestinal parasitism was as high as 63.8%, with predominance of Ascaris lumbricoides (22.4%) and Trichuris trichiura (17.9%). Polyparasitism occurred in 36.5% of those investigated. A double-blind randomized controlled trial assessed 65 individuals in two treatment groups. Cure rates were 32.4% and 38.7% with nitazoxanide and conventional treatment, respectively, but the difference was not statistically significant (p = 0.599). Vomiting (p = 0.031) was associated with conventional treatment and greenish urine with nitazoxanide use (p = 0.002). Other untoward effects were independent of which drug was used. There was a statistically significant difference concerning skin color and cure rates for both treatments. Dark-skinned subjects had lower cure rates. Further studies are necessary to clarify the reasons for the low effectiveness found in these cases of polyparasitism, and to reevaluate preventive and therapeutic approaches with new and broad-spectrum drugs, nitazoxanide being an option in this context. In addition to new therapeutic approaches, there is a clear need to develop public policies that, through the provision of basic sanitation, health education and access to the public health system, assure quality of life and minimize inequity.

The pharmacokinetics of two antimicrobials were investigated in alpacas. Six healthy alpacas were each administered a single dose of 10 mg/kg of oxytetracycline by IV injection and IM injection. In addition, a single dose of 20 mg/kg of florfenicol by IV administration was given to alpacas in a separate study. The pharmacokinetic parameters of oxytetracycline and florfenicol in alpacas were compared to the results previously obtained in llamas. There were significant differences between llamas and alpacas in several of oxytetracycline pharmacokinetic parameters but there were no significant differences in all of florfenicol pharmacokinetic parameters in these two animals. It can be concluded that llamas and alpacas have different oxytetracycline disposition kinetics while they have similar disposition kinetics of florfenicol. The pharmacokinetics of clorsulon, a narrow-spectrum anthelmintic agent, was investigated in llamas following oral administration at a single dose of 14 mg/kg. The plasma levels of clorsulon produced by this dose was lower than the values reported in the clorsulon pharmacokinetic studies carried out in sheep and goats following oral administration at a single dose of 7 mg/kg This suggests the entire dose of clorsulon is not absorbed in llamas. Since the differential equations describing one-compartment system with first-order input and two-compartment system after IV administration with nonlinear elimination kinetics cannot be solved, there is no mathematical expression for the AUC for drugs following these models. The AUC values calculated from the proposed preliminary AUC equations for drugs following these models were compared to the AUC calculated using the trapezoidal rule method based on computer-generated data using the fourth-order Runge-Kutta method. Except for a few exceptions, the predicted AUC from the proposed equations matched the values calculated from the theoretically generated data.<br>Graduation date: 2004

no<br>Candidiasis is one of the most frequent opportunistic infections in individuals with severe immunosupression and further development of resistance against the available antifungal drugs has created an alarming situation. This requires intensive drug discovery to develop new, more effective, affordable and accessible antifungal agents possessing novel modes of action. Albizia anthelmintica, which is ethno medically used to treat vaginal candidiasis in the Morogoro and coastal regions of Tanzania, on activity guided fractionation and subsequent purification resulted in the isolation and characterization of an isomer of methyl cyclitol (1) and six echinocystic acid saponins (2–7). Saponins 6 and 7 are new and being reported for the first time from nature. Among all the isolated compounds, 3-O-[α-L-arabinopyranosyl (1[RIGHTWARDS ARROW]2)][α-L-arabinopyranosyl (1[RIGHTWARDS ARROW]6)]-2-acetamido-2-deoxy-β-D-glucopyranosyl echinocystic acid (4), 3-O-[α-L-arabinopyranosyl (1[RIGHTWARDS ARROW]2)] [α-L-arabinopyranosyl (1[RIGHTWARDS ARROW]6)]-2-amino-2-deoxy-β-D-glucopyranosyl echinocystic acid (6) and 3-O-[β-D-glucopyranosyl (1[RIGHTWARDS ARROW]3)] [α-L-arabinopyranosyl (1[RIGHTWARDS ARROW]2)] [α-L-arabinopyranosyl (1[RIGHTWARDS ARROW]6)]-2-amino-2-deoxy-β-D-glucopyranosyl echinocystic acid (7) and their combinations were active against the various strains of C. albicans with MICs ranging from 12.5 to 125 μg/ml.

Infection of small ruminants by gastrointestinal nematodes (GIN) is a major health concern because they cause substantial economic losses, especially in the tropics and sub-tropics. For many years, control of GIN has been based upon use of anthelmintics. However, there is now a global challange because mutant GIN individuals can tolerate most of the widely used anthelmintics. Therefore, alternative control measures are needed. The objective of the study was to screen a number of plant species for their anthelmintic effects, and to evaluate selected strains of Bacillus thuringiensis (Berliner) and Clonostachys rosea (Schroers) for activity against sheep GIN. Subsequently, the combined treatments would test a dual control strategy for nematodes by using a combination of plant extracts with biocontrol agents. Ethanol extracts of 25 plant species were screened for their anthelmintic effects against Haemonchus contortus (Rudolphi 1803). Extracts of each plant were used in vitro at various concentrations (10, 20 and 30%) to treat 10 day faecal cultures. Five plants with high efficacies (Ananas comosus L. Merr., Aloe ferox Mill., Allium sativum Linn., Lespedeza cuneata Dum. Cours. and Warburgia salutaris Bertol.f. Chiov) were selected for further investigation, using ethanol, dichloromethane and water extracts at four concentrations (2.5, 5, 10 and 20%). Ethanol was the most effective solvent. Larval counts decreased as a result of increasing extract concentrations. An ethanolic extract of Lespedeza cuneata caused more than 70% mortality at all concentrations. In an in vivo study, the five plants A. comosus, A. ferox, A. sativum, L. cuneata and W. salutaris extracts were compared to a positive Control (Equimax®, a modern anthelmintic based on abamectin and praziquantel). Gender, eggs count (EPG₀) and initial body weights were used in assigning sheep (24 females and 24 males) to six groups. Each group was randomly assigned a treatment. Plant extracts were applied as an oral dose (100 mg kg⁻¹ BW), one dose per week per animal for 42 days (Phase 1). Subsequently, the same sheep were dosed for three consecutive days with the same treatments, keeping them in the same groups (Phase 2). Rectal faecal samples were taken for counting of eggs per gram of faeces (EPG) and L₃ larvae per gram (LPG) in faecal cultures. With application of plant extracts, the EPG count decreased with time (P<0.001), and the impact of the plant extracts increased (P<0.001) with time. Two extracts, from A. comosus and L. cuneata, were the most effective in Phase 1 (58% and 61% reduction of EPG, respectively,), and in Phase 2 (77% and 81% reduction of EPG, respectively). In a study on potential biocontrol agents, two strains of Bacillus thuringiensis (Bt) and one of Clonostachys rosea f. rosea (C. rosea), and compared with a diatomaceous earth (DE) product for their anthelmintic activity in sheep. Bacillus thuringiensis and C. rosea were fed to sheep at a rate of 1g kg⁻¹ BW, and DE was fed at 2% of sheep diet. The biocontrol treatments had no effect on EPG (P>0.05), but reduced GIN larvae per gram (LPG) (P<0.001) in faecal culture. Efficacy varied with time (P<0.001). By Day 7 Bt, C. rosea and DE had caused mortalities of GIN of 75.7, 86.9 and 60.6%, respectively. In addition, the efficacy of feeding 1g kg⁻¹ BW of C. rosea chlamydospores to sheep every day, every second day and every third day was tested. Daily feeding of fungal chlamydospores reduced LPG (a count of 12±1.67 GIN larvae) (P<0.001) more than feeding them the biocontrol agent every second day (39±0.77) or third day (58±1.77). By Day 12, feeding the biocontrol agent to sheep every day, every second day, or every third day caused mortality of GIN larvae of 90, 63 and 49%, respectively. Four dietary levels (treatments) of C. rosea (0.25g (F1), 0.5g (F2), 1g (F3) and control (C) of C. rosea product kg-1 BW) were tested. Treatments were each mixed with a complete diet and fed to sheep once daily for 10 weeks, according to body weights. Increased doses of the biocontrol agent reduced LPG (P<0.001), larval development (LD) (P<0.001), and increased efficacy (P<0.001). On Day 70, F1, F2, F3 and the Control controlled LD by 33.3, 72.3, 89.4 and 2.6%, respectively. Clonostachys rosea was effective in reducing third stage larvae (L₃) on pastures significantly (P<0.001) by Day 63 and Day 70. Ethanolic extracts of A. comosus, A. ferox, A. sativum, L. cuneata and W. salutaris all reduced egg production by GIN parasites of sheep. Feeding sheep cultured chlamydospores of a biocontrol fungus, Clonostachys rosea, reduced counts of nematode larvae in sheep; and 1g C. rosea chlamydospores kg⁻¹ BW daily was enough to reduce nematode infective larvae, therefore reducing the degree of pasture contamination. An initial trial showed that the combination of the two treatments of an A. comosus extract and C. rosea chlamydospores was more effective than either treatment on its own in controlling gastrointestinal nematodes in sheep. A long-term trial is being undertaken currently to confirm this finding.<br>Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.