101
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Cortese L, Pelagalli A, Piantedosi D, Mastellone V, Di Loria A, Lombardi P, Ciaramella P, Avallone L. The effects of prednisone on haemostasis in leishmaniotic dogs treated with meglumine antimoniate and allopurinol. Vet J 2007; 177:405-10. [PMID: 17629526 DOI: 10.1016/j.tvjl.2007.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Revised: 04/26/2007] [Accepted: 05/15/2007] [Indexed: 11/20/2022]
Abstract
Thirty dogs naturally infected with Leishmania infantum were studied in order to determine the effects of treatment on haemostatic function. The animals were divided randomly into two treatment groups: Group 1 received meglumine antimoniate and allopurinol; Group 2 dogs were given the same treatment plus prednisone. Ten healthy animals were used as untreated controls. Clinical examination and determination of platelet aggregation, coagulation factors and biochemical parameters were undertaken before treatment and after 15, 30 and 60 days. A significant improvement in platelet aggregation was detected after 60 days in Group 1, but only after 15 days in Group 2. In both treated groups, platelet aggregation was lower than in the control group at the end of the study. The results suggest that prednisone may be a useful tool in the treatment of haemostatic disorders during canine leishmaniosis. The potential benefits and risks due to the use of corticosteroids in the treatment of leishmaniosis are discussed.
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Affiliation(s)
- Laura Cortese
- Department of Veterinary Clinical Sciences, University of Naples Federico II, Via Delpino 1, 80137, Italy
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102
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Rosypal AC, Hall JE, Bakunova S, Patrick DA, Bakunov S, Stephens CE, Kumar A, Boykin DW, Tidwell RR. In vitro activity of dicationic compounds against a North American foxhound isolate of Leishmania infantum. Vet Parasitol 2007; 145:207-16. [PMID: 17298866 DOI: 10.1016/j.vetpar.2007.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Revised: 01/10/2007] [Accepted: 01/10/2007] [Indexed: 11/23/2022]
Abstract
Canine leishmaniasis caused by Leishmania infantum is enzootic in the North American foxhound population. Currently available chemotherapy for canine leishmaniasis is not completely effective and relapses are common in treated dogs. Pentamidine and related aromatic diamidines possess broad spectrum antiprotozoal activity. The in vitro antileishmanial activities of 35 aromatic cationic molecules were determined, using pentamidine as the reference drug. The compounds were examined for activity against promastigotes of L. infantum isolated from a foxhound from Virginia. The compounds most active against Leishmania parasites were reversed amidines. Compound 9, a reversed amidine, exhibited the highest activity against L. infantum, with a 50% inhibitory concentration (IC(50)) of 0.0042 microM compared with 14.2 microM for pentamidine. Antileishmanial activities of nine compounds were at least 1000-fold higher relative to the reference drug. Results from this study indicate that several pentamidine-related compounds warrant further investigation as possible new agents for the treatment of canine leishmaniasis.
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Affiliation(s)
- Alexa C Rosypal
- School of Medicine, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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103
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Ikeda-Garcia FA, Lopes RS, Marques FJ, de Lima VMF, Morinishi CK, Bonello FL, Zanette MF, Perri SHV, Feitosa MM. Clinical and parasitological evaluation of dogs naturally infected by Leishmania (Leishmania) chagasi submitted to treatment with meglumine antimoniate. Vet Parasitol 2007; 143:254-9. [PMID: 16996214 DOI: 10.1016/j.vetpar.2006.08.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 08/07/2006] [Accepted: 08/07/2006] [Indexed: 11/22/2022]
Abstract
Aiming to evaluate the efficacy of the treatment of canine visceral leishmaniasis, to verify the occurrence of a possible disease relapse, and to search for the presence of the parasites after the end of the treatment, seven dogs naturally infected by Leishmania (Leishmania) chagasi were used. The dogs were subjected to a treatment with 75 mg/kg meglumine antimoniate subcutaneously every 12 h for 21 days, and followed-up for a period of 6 months. During the whole experimental period the animals wore deltamethrin collars and were kept in a screened kennel to avoid reinfection. Lymph node and bone marrow aspiration biopsy was carried out to search for the parasite at seven moments: before the treatment, 30, 60, 90, 120, 150 and 180 days after the start of the treatment. After the end of the experiment all dogs were humanely euthanized. Then, spleen and liver "imprints" and in vitro cultures were carried out to search for amastigote forms of the parasite. During the treatment all animals presented remission of symptoms. However, two dogs were observed to present new symptoms in the course of the experiment. At the end of the experiment, the presence of amastigote forms of the parasite was evidenced in five of the seven dogs. This enabled us to conclude that the treatment promoted clinical cure but did not eliminate the parasites completely.
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Affiliation(s)
- Fabiana Augusta Ikeda-Garcia
- Department of Clinics, Surgery and Animal Reproduction, School of Veterinary Medicine, UNESP, São Paulo State University, Rua: Clóvis Pestana n. 793, CEP 16050-680, Araçatuba, São Paulo, Brazil
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104
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Baneth G, Aroch I. Canine leishmaniasis: a diagnostic and clinical challenge. Vet J 2007; 175:14-5. [PMID: 17215150 DOI: 10.1016/j.tvjl.2006.11.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Accepted: 11/18/2006] [Indexed: 11/26/2022]
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105
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Lage RS, Oliveira GC, Busek SU, Guerra LL, Giunchetti RC, Corrêa-Oliveira R, Reis AB. Analysis of the cytokine profile in spleen cells from dogs naturally infected by Leishmania chagasi. Vet Immunol Immunopathol 2007; 115:135-45. [PMID: 17097741 DOI: 10.1016/j.vetimm.2006.10.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 08/22/2006] [Accepted: 10/04/2006] [Indexed: 10/24/2022]
Abstract
Recent studies suggest that asymptomatic dogs infected with canine visceral leishmaniasis (CVL) develop a Th1 immunological profile whilst oligosymptomatic and symptomatic CVL-infected animals present a Th2 profile. In the present study, an RT-PCR method has been standardised and employed to evaluate the frequency and the semi-quantitative level of expression of the cytokines IL-4, IL-10, IL-12, INF-gamma and TNF-alpha in splenocytes of 30 dogs naturally infected with Leishmania chagasi and of 7 non-infected dogs (NID). An increase in the level of expression of IL-12 (p=0.059) was detected in all CVL-infected dogs compared with NID. In dogs exhibiting high parasitism, the frequency of expression of IL-10 was higher (p=0.011) than in animals presenting low parasitism or medium parasitism (MP) and in NID animals, whilst the level of expression of IL-10 was higher (p=0.0094) than in animals exhibiting MP and in the NID group. Positive correlations between the levels of expression of IL-10 with respect to the progression of the disease (IL-10: r=0.3510; p=0.0337) and the levels of expression of IL-10 and INF-gamma increase in parasitism (IL-10: r=0.3428; p=0.0438 and INF-gamma: r=0.4690; p=0.0045) were observed. Such data suggest that CVL is marked by a balanced production of Th1 and Th2 cytokines, with a predominant accumulation of IL-10 as a consequence of an increase in parasitic load and progression of the disease, and INF-gamma was related with the increase in parasitic load.
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Affiliation(s)
- R S Lage
- Laboratório de Imunologia Celular e Molecular, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
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106
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João A, Pereira MA, Cortes S, Santos-Gomes GM. Canine Leishmaniasis Chemotherapy: Dog's Clinical Condition and Risk of Leishmania Transmission. ACTA ACUST UNITED AC 2006; 53:540-5. [PMID: 17105576 DOI: 10.1111/j.1439-0442.2006.00869.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of this study was to investigate whether treatment against canine leishmaniasis reduced the presence of Leishmania in the healthy skin of dogs, affecting the capacity of parasite transmission. A total of 37 dogs from an endemic region of leishmaniasis were studied. Thirteen symptomatic animals revealed parasites in the bone marrow and eight had also in the skin. Five of the 22 dogs that had been treated with meglumine antimoniate alone, meglumine antimoniate or trifluralin followed by allopurinol or just with allopurinol had the parasite in bone marrow but none showed Leishmania in the skin. One dog that was treated only with aminosidine was polisymptomatic and had parasites in bone marrow and skin. The different treatments used in this study did not completely eliminate the parasite allowing relapses to occur when the treatment is discontinued, but the use of meglumine antimoniate or allopurinol, alone or combined may improve dogs clinical condition and reduce or eliminate the parasite from the skin decreasing the probability of Leishmania transmission.
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Affiliation(s)
- A João
- Unidade de Leishmanioses e Centro de Malária e Outras Doenças Tropicais, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 96, 1349-008 Lisboa, Portugal
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107
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Carrillo E, Ahmed S, Goldsmith-Pestana K, Nieto J, Osorio Y, Travi B, Moreno J, McMahon-Pratt D. Immunogenicity of the P-8 amastigote antigen in the experimental model of canine visceral leishmaniasis. Vaccine 2006; 25:1534-43. [PMID: 17178178 PMCID: PMC2571115 DOI: 10.1016/j.vaccine.2006.10.036] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Revised: 10/15/2006] [Accepted: 10/20/2006] [Indexed: 11/29/2022]
Abstract
The P-8 proteoglycolipid complex (P-8 PGLC), an amastigote antigen of Leishmania pifanoi, has been demonstrated to induce protection in mouse models, as well as to induce Tc1/Th1-like cellular responses in American cutaneous leishmaniasis patients. Because the immunization with P-8 PGLC in the murine model does not appear to be genetically restricted, we have studied the reactivity of the P-8 PGLC in Leishmania infantum infected dogs. In this study, it is shown that PBMC from experimentally infected dogs (asymptomatic, oligosymptomatic) significantly proliferated in response to soluble leishmanial antigen (SLA) or the P-8 PGLC. Further, quantification of the gene expression induced by the stimulation with P-8 in asymptomatically infected dogs showed an up-regulation of IFN-gamma and TNF-alpha, which were three to 4-fold higher than that induced by soluble Leishmania antigen (SLA). While no measurable induction of IL-10 was observed, low levels of IL-4 mRNA were observed in response to both P-8 and SLA antigens. Thus, our studies establish that P-8 is recognized by infected canines and elicits a potentially curative/protective Th1-like immune response. The identification of Leishmania antigens that elicit appropriate immune responses across different host species (humans, canine) and disease manifestations (cutaneous or visceral) could be an advantage in generating a general vaccine for leishmaniasis.
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Affiliation(s)
- E Carrillo
- WHO Collaborating Centre for Leishmaniasis, Instituto de Salud Carlos III, Ctra. Majadahonda-Pozuelo km. 2, 28220 Madrid, Spain
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108
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Santos M, Marcos R, Assunção M, Matos AJF. Polyarthritis associated with visceral leishmaniasis in a juvenile dog. Vet Parasitol 2006; 141:340-4. [PMID: 16824686 DOI: 10.1016/j.vetpar.2006.05.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 05/22/2006] [Accepted: 05/29/2006] [Indexed: 11/29/2022]
Abstract
Canine visceral leishmaniasis (CL) is a zoonosis and a chronic systemic disease characterized by a wide spectrum of clinical signs, including, in rare occasions, polyarthritis. This report describes a case of CL in an 8-month old male boxer dog with a history of lameness, fever and lymphadenopathy. A definitive diagnosis of CL was based on the observation of the Leishmania amastigotes seen concomitantly, and for the first time, in the lymph nodes aspiration smears (in macrophages), synovial fluid (in macrophages and neutrophils) and blood (in neutrophils). Despite this extensive dissemination of the parasite, the animal was successfully treated with a multi-step combination of meglumine antimoniate, aminosidine and allopurinol.
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Affiliation(s)
- Marta Santos
- Cytology Diagnostic Services, Laboratory of Histology and Embryology, ICBAS - Institute of Biomedical Sciences Abel Salazar, Porto, Portugal.
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109
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Plevraki K, Koutinas A, Kaldrymidou H, Roumpies N, Papazoglou L, Saridomichelakis M, Savvas I, Leondides L. Effects of Allopurinol Treatment on the Progression of Chronic Nephritis in Canine Leishmaniosis (Leishmania infantum). J Vet Intern Med 2006. [DOI: 10.1111/j.1939-1676.2006.tb02850.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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110
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de Koning HP, Bridges DJ, Burchmore RJS. Purine and pyrimidine transport in pathogenic protozoa: From biology to therapy. FEMS Microbiol Rev 2005; 29:987-1020. [PMID: 16040150 DOI: 10.1016/j.femsre.2005.03.004] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Revised: 03/22/2005] [Accepted: 03/24/2005] [Indexed: 01/10/2023] Open
Abstract
Purine salvage is an essential function for all obligate parasitic protozoa studied to date and most are also capable of efficient uptake of preformed pyrimidines. Much progress has been made in the identification and characterisation of protozoan purine and pyrimidine transporters. While the genes encoding protozoan or metazoan pyrimidine transporters have yet to be identified, numerous purine transporters have now been cloned. All protozoan purine transporter-encoding genes characterised to date have been of the Equilibrative Nucleoside Transporter family conserved in a great variety of eukaryote organisms. However, these protozoan transporters have been shown to be sufficiently different from mammalian transporters to mediate selective uptake of therapeutic agents. Recent studies are increasingly addressing the structure and substrate recognition mechanisms of these vital transport proteins.
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Affiliation(s)
- Harry P de Koning
- Institute of Biomedical and Life Sciences, Division of Infection and Immunity, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK.
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111
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Al-Mohammed HI, Chance ML, Bates PA. Production and characterization of stable amphotericin-resistant amastigotes and promastigotes of Leishmania mexicana. Antimicrob Agents Chemother 2005; 49:3274-80. [PMID: 16048936 PMCID: PMC1196255 DOI: 10.1128/aac.49.8.3274-3280.2005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The sensitivities of Leishmania mexicana amastigote and promastigote forms to amphotericin B were investigated in vitro and found to be strongly influenced by the culture media used. When differences in culture media were minimized, there was no significant difference in the 50% inhibitory concentration values between the two life cycle stages. Stable amphotericin B-resistant amastigote and promastigote lines were produced by the application of increasing drug pressure to long-term cultures. Lines capable of growth in concentrations of amphotericin B lethal to normal parasites were produced. Compared to normal parasites, these amphotericin-resistant lines showed marked differences in membrane sterol compositions, with very high levels of 4,14,dimethyl-cholesta-8,24-dienol and other methyl sterols. They also showed a consistent morphological feature, the presence of multilamellar membrane-like material in the flagellar pocket, revealed by transmission electron microscopy. Amphotericin-resistant parasites were capable of infecting BALB/c mice, but the resulting lesion growth was slower than that after infection with normal parasites. However, unlike normal parasites, the amphotericin-resistant parasites were unaffected by experimental chemotherapy with amphotericin B. These results show that amphotericin B resistance could arise as a result of increased clinical use of amphotericin B therapy.
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Affiliation(s)
- Hamdan I Al-Mohammed
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom
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112
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Abstract
Canine visceral leishmaniasis is a systemic disease caused by Leishmania infantum. The aim of this systematic review was to identify and evaluate the evidence of efficacy of interventions for treatment or prevention of canine visceral leishmaniasis, and to propose recommendations for or against their use. Forty-seven articles describing clinical trials published between 1980 and 2004 fulfilled selection criteria. The evaluation of clinical trials provided good evidence for recommending the use of meglumine antimoniate at a minimum dosage of 100 mg kg(-1) daily for at least 3-4 weeks, combined with allopurinol in order to obtain a good clinical efficacy and a reduced relapse rate. The evaluation of the articles also provided fair evidence for recommending the use of pentamidine (4 mg kg(-1) twice weekly) and aminosidine (5 mg kg(-1) twice daily) for 3-4 weeks. There was insufficient evidence for recommending the use of allopurinol alone, amphotericin B, buparvaquone, ketoconazole, enrofloxacin, and the combinations of metronidazole with spiramicyn or metronidazole with enrofloxacin. Fair evidence against the use of aminosidine at high dosages (20-80 mg kg(-1) per day) was proposed due to its side effects. Evaluation of articles on repellent measures against sand fly vectors of leishmaniasis provided good evidence for recommending deltamethrin collars and fair evidence for recommending spot-on permethrin.
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Affiliation(s)
- Chiara Noli
- Ospedale Veterinario Cuneese, Via Cuneo 52/N, 12011 Borgo S. Dalmazzo (CN), Italy.
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113
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Poot J, Rogers ME, Bates PA, Vermeulen A. Detailed analysis of an experimental challenge model for Leishmania infantum (JPC strain) in dogs. Vet Parasitol 2005; 130:41-53. [PMID: 15893068 DOI: 10.1016/j.vetpar.2005.03.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 02/17/2005] [Accepted: 03/09/2005] [Indexed: 10/25/2022]
Abstract
In this study, disease progression after intravenous or subdermal infection of dogs with Leishmania infantum JPC strain was monitored. A challenge performed on 14 dogs via the intravenous route with 5 x 10(7) stationary phase promastigotes of the L. infantum JPC strain was 100% successful. During a follow up period of 1.5 years, several parameters were evaluated in order to find the most reliable disease markers. Parasite detection by culture and histology were found to be very sensitive (100%). Additionally, regular physical examination, serology and serum gamma-globulin levels were found to be useful parameters in the evaluation of disease severity and are recommended for inclusion in vaccination-challenge experiments. Although this intravenous challenge model has practical limitations, the data set confirms it is the best experimental model currently available for vaccine development. Two intravenously infected dogs were treated with corticosteroids for 5 months. This treatment was shown to enhance all aspects of a Leishmania infection. Five more dogs were infected by sub-dermal injection of promastigotes mixed with a proteophosphoglycan-matrix (PSG) secreted by Leishmania that assists in transmission and infection by sand fly bite. The resulting parasite burdens were low and the animals remained asymptomatic during a 2-year follow up period. However, this procedure did result in infection in 80% of the dogs and is appealing for future development as a natural challenge model in vaccine development.
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Affiliation(s)
- Jacqueline Poot
- Intervet International B.V., Parasitology R&D, Wim de Körverstraat 35, 5831 AN Boxmeer, The Netherlands.
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114
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Pasa S, Toz SO, Voyvoda H, Ozbel Y. Clinical and serological follow-up in dogs with visceral leishmaniosis treated with allopurinol and sodium stibogluconate. Vet Parasitol 2005; 128:243-9. [PMID: 15740861 DOI: 10.1016/j.vetpar.2004.12.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Revised: 11/30/2004] [Accepted: 12/13/2004] [Indexed: 11/28/2022]
Abstract
Seven dogs with parasitologically proven clinical visceral leishmaniosis (Leishmania infantum infection) were treated with a combination of allopurinol and sodium stibogluconate. The dogs received first orally 15 mg/kg of allopurinol every 12 h until the clinical signs improved, in the following 1 month period allopurinol at same dose and subcutaneously 30 mg/kg of sodium stibogluconate combination were given daily and at the end of the combined treatment, allopurinol was continued alone at the same dose till the end of 8 months. During the treatment period, dogs were supported by additional proteins, vitamins, and minerals. A long acting insecticide (collar or drop) was also used in order to prevent further parasite transmission. Follow-up was maintained by clinical, clinicopathological evaluation, and parasitological examination of lymph node, serology using the indirect immunofluorescent antibody test (IFAT). Before treatment commenced, the most important clinical signs were exfoliative dermatitis, ulcerations, peripheral lymhadenopathy, pale mucous membranes, weight loss, and ocular lesions. Clinicopathological findings included commonly anaemia, hyperproteinaemia, hyperglobulinaemia and hypoalbuminaemia. Before the treatment, amastigotes were seen in six of the seven dogs by examination of lymph node aspiration, and IFAT-titers were positive in all dogs. At the end of 8 months treatment, remission of clinical signs, restoration to normal of clinicopathological abnormalities were noticed. Lymph node aspiration was performed on three out of the seven dogs at the end of the treatment because of the very small sizes of the lymph nodes, and no amastigotes were observed. Although the mean IFAT-titer of the dogs were significantly (P < 0.001) lower compared with pretreatment, IFAT-titers of dogs were still positive. No relapses occurred during treatment period and a 6-24-month duration after the end of therapy. Based on the above results, long-term use of allopurinol combined with sodium stibogluconate together with support treatment concluded to have enough therapeutic efficacies in the treatment of dogs with visceral leishmaniosis. Observations of the cases for possible relapses were still going on and insecticide application was carefully carrying on in order preventing a possible re-infection.
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Affiliation(s)
- Serdar Pasa
- Department of Internal Medicine, Faculty of Veterinary, University of Adnan Menderes, Aydin 09016, Turkey.
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115
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Natto MJ, Wallace LJM, Candlish D, Al-Salabi MI, Coutts SE, de Koning HP. Trypanosoma brucei: expression of multiple purine transporters prevents the development of allopurinol resistance. Exp Parasitol 2005; 109:80-6. [PMID: 15687014 DOI: 10.1016/j.exppara.2004.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Revised: 11/03/2004] [Accepted: 11/18/2004] [Indexed: 11/26/2022]
Abstract
Allopurinol is a hypoxanthine analogue used to treat Leishmania infections that also displays activity against the related parasite Trypanosoma brucei. We have investigated the ease by which resistance to this drug is established in Trypanosoma brucei brucei and correlated this to the mechanisms by which it is accumulated by the parasite. Long-term exposure of procyclic T. b. brucei to 3mM allopurinol did not induce resistance. This appears to be related to the fact that allopurinol was taken up through two distinct nucleobase transporters, H1 and H4, both with high affinity for the drug. The apparent Km for [3H]allopurinol transport by H4 (2.1+/-0.4 microM) was determined by expressing the encoding gene in Saccharomyces cerevisiae. Long-term allopurinol exposure did not change Km (hypoxanthine), Ki (allopurinol), or Vmax values of either H1 or H4 transporters and the cells retained their ability to proliferate with hypoxanthine as sole purine source. This study shows that transport-related resistance to purine antimetabolites is not easily induced in Trypanosoma spp. as long as uptake is mediated by multiple transporters.
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Affiliation(s)
- Manal J Natto
- Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Joseph Black Building, Glasgow G12 8QQ, UK
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116
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Papadopoulou C, Kostoula A, Dimitriou D, Panagiou A, Bobojianni C, Antoniades G. Human and canine leishmaniasis in asymptomatic and symptomatic population in Northwestern Greece. J Infect 2005; 50:53-60. [PMID: 15603841 DOI: 10.1016/j.jinf.2004.05.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2004] [Indexed: 11/29/2022]
Abstract
The occurrence of human and canine Mediterranean visceral leishmaniasis (MVL) in Northwestern Greece was investigated during an 8-year survey (1994-2001). A total of 1200 blood sera samples, collected from asymptomatic human population, and 1200 blood sera samples from asymptomatic dogs were screened for Leishmania infantum antibodies using the indirect immunofluorescence test (IFA). Also during the survey 111 human subjects and 350 canines were referred as clinically suspect cases for MVL. Significant differences (p = 0.001) were found between the prevalence of MVL in symptomatic and asymptomatic human populations (12.6 and 0.5%, respectively), but a more modest difference was observed between symptomatic and asymptomatic canines (45.4 and 24.4%, respectively). From the results, it appears that Greece has a high background of canine leishmaniasis, which is likely to be a risk factor for the emergence of human MVL.
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Affiliation(s)
- C Papadopoulou
- Zoonoses and Parasitology Unit, Department of Microbiology, Medical School, Dourouti University Campus, University of Ioannina, 45110 Ioannina, Greece.
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117
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Strauss-Ayali D, Baneth G, Shor S, Okano F, Jaffe CL. Interleukin-12 augments a Th1-type immune response manifested as lymphocyte proliferation and interferon gamma production in Leishmania infantum-infected dogs. Int J Parasitol 2004; 35:63-73. [PMID: 15619517 DOI: 10.1016/j.ijpara.2004.10.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 10/19/2004] [Accepted: 10/19/2004] [Indexed: 10/26/2022]
Abstract
The dog is the major reservoir for human visceral leishmaniasis caused by Leishmania infantum. Interleukin-12 is considered to have an essential role in the development of both innate and adaptive immunity to Leishmania spp. and other intracellular pathogens. This study focused on the influence of IL-12 in experimental and natural canine visceral leishmaniasis. Responses of peripheral blood mononuclear cells to IL-12, interleukin-10 and Leishmania soluble antigen were evaluated in L. infantum experimentally infected oligosymptomatic beagles, uninfected beagles, naturally infected polysymptomatic dogs, and their matched uninfected controls. Leishmania soluble antigen induced strong peripheral blood mononuclear cells proliferation both in experimentally infected dogs (median stimulation index [SI]=15.01), and in naturally infected dogs (SI=8.86), but not by cells from the control groups. IL-12 addition further enhanced cell proliferation in naturally (SI=14.95), but not in experimentally infected animals. Peripheral blood mononuclear cells from experimentally infected dogs were able to produce significant amounts of IFN-gamma (3.39 ng/ml) upon LSA stimulation, but no such production was detected in cells from naturally infected or control animals. Interestingly, addition of IL-12 reversed the inhibitory effect of LSA on IFN-gamma production by cells from polysymptomatic naturally infected dogs and the uninfected beagles (4.84 and 7.45 ng/ml, respectively), and further increased IFN-gamma production by peripheral blood mononuclear cells from experimentally infected oligosymptomatic dogs (29.28 ng/ml). IFN-gamma mRNA expression correlated well with IFN-gamma production. Addition of IL-10 to Leishmania soluble antigen stimulated peripheral blood mononuclear cells inhibited proliferation and IFN-gamma production in experimentally infected dogs. Thus, the ability of IL-12 to augment IFN-gamma production by peripheral blood mononuclear cells from dogs with experimental or natural symptomatic canine visceral leishmaniasis makes it a good candidate for cytokine therapy in dogs that are refractory to current therapy.
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Affiliation(s)
- Dalit Strauss-Ayali
- School of Veterinary Medicine, Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel.
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118
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Cardoso L, Schallig HDFH, Neto F, Kroon N, Rodrigues M. Serological survey of Leishmania infection in dogs from the municipality of Peso da Régua (Alto Douro, Portugal) using the direct agglutination test (DAT) and fast agglutination screening test (FAST). Acta Trop 2004; 91:95-100. [PMID: 15234658 DOI: 10.1016/j.actatropica.2004.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2003] [Revised: 11/14/2003] [Accepted: 03/05/2004] [Indexed: 11/20/2022]
Abstract
Leishmaniasis caused by Leishmania infantum is a prevalent disease in dogs and humans. A serological survey of Leishmania infection in dogs was carried out in the endemic region of Alto Douro (north Portugal). Two hundred and ninety-four dogs from the municipality of Peso da Régua were examined for clinical signs of canine leishmaniasis (CanL), and sera samples were evaluated by the direct agglutination test (DAT) and the fast agglutination screening test (FAST). The sero-prevalence of infection was 20.4%, after screening the study population by FAST and subsequent confirmation by DAT. The overall prevalence of disease was 3.1%. Only 15.0% of the sero-positive dogs had clinical signs of CanL. A high degree of agreement (88.4%; kappa value = 0.71) was found between DAT and FAST. This study further demonstrates that FAST can be used as a simple, rapid and sensitive screening test for canine Leishmania infection in areas of high endemicity and, together with DAT, is a valuable tool in the assessment of CanL.
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Affiliation(s)
- Luís Cardoso
- Department of Hygiene and Animal Health, CECAV, University of Trás-os-Montes e Alto Douro, 5001-911 Vila Real, Portugal.
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119
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dos Santos LR, Barrouin-Melo SM, Chang YF, Olsen J, McDonough SP, Quimby F, dos Santos WLC, Pontes-de-Carvalho LC, Oliveira GGDS. Recombinant single-chain canine interleukin 12 induces interferon gamma mRNA expression in peripheral blood mononuclear cells of dogs with visceral leishmaniasis. Vet Immunol Immunopathol 2004; 98:43-8. [PMID: 15127840 DOI: 10.1016/j.vetimm.2003.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Canine visceral leishmaniasis poses important concerns for public health and veterinary medicine in many areas of the world. Resistance to it seems to be associated with cellular specific immune responses of the so-called Th1 type. Interleukin-12 (IL-12) is one of the most potent inducers of Th1 type of immune responses to co-administered antigens. Herein, the cloning of canine IL-12, as a single-chain fusion protein (sccaIL-12), and its expression in biologically active form in COS-7 cells is reported. Supernatants from these cells stimulated the expression of comparable amounts of interferon gamma mRNA in peripheral blood mononuclear cells from dogs with natural visceral leishmaniasis. In addition, after stimulation with sccaIL-12, there was no difference between interferon gamma mRNA expressions in peripheral blood mononuclear cells of dogs with visceral leishmaniasis and from normal healthy control animals.
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Affiliation(s)
- Lenita Ramires dos Santos
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão, No. 121, Brotas, Salvador-Bahia, CEP 40295-001, Brazil
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120
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Alberola J, Rodríguez A, Francino O, Roura X, Rivas L, Andreu D. Safety and efficacy of antimicrobial peptides against naturally acquired leishmaniasis. Antimicrob Agents Chemother 2004; 48:641-3. [PMID: 14742227 PMCID: PMC321547 DOI: 10.1128/aac.48.2.641-643.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leishmaniases, which are important causes of morbidity and mortality in humans and dogs, are extremely difficult to treat. Antimicrobial peptides are rarely used as alternative treatments for naturally acquired parasitic diseases. Here we report that the acylated synthetic antimicrobial peptide Oct-CA(1-7)M(2-9) is safe and effective for treating naturally acquired canine leishmaniasis.
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Affiliation(s)
- J Alberola
- Departament de Farmacologia, Terapèutica i Toxicologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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121
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Rosypal AC, Zajac AM, Lindsay DS. Canine visceral leishmaniasis and its emergence in the United States. Vet Clin North Am Small Anim Pract 2003; 33:921-37, viii. [PMID: 12910750 DOI: 10.1016/s0195-5616(03)00030-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Leishmaniasis is an important zoonotic disease that accounts for approximately 57,000 deaths among people each year. Dogs are reservoirs for the disease, and dog ownership is a risk factor in endemic areas. This article discusses insect vectors for this disease, as well as diagnosis and treatment for dogs.
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Affiliation(s)
- Alexa C Rosypal
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, 1410 Prices Fork Road, Blacksburg, VA 24061, USA
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