[leish-l] Fwd: Articles found by RefScout 49/2004-01/12/2004

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Wed Dec 1 11:04:46 BRST 2004


    Date: Wed, 1 Dec 2004 08:16:52
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This is RefScout-Newsletter 49/2004.


REQUEST: [ leishmaniasis ]

(7 articles match this request. 1 article matching other requests removed)



PMID: 15567136
 

TITLE: Sudanese mucosal leishmaniasis: isolation of a parasite within the
Leishmania donovani complex that differs genotypically from L. donovani causing
classical visceral leishmaniasis.

AUTHORS: Muzamil Mahdi, Elwaleed M Elamin, Sara E Melville, Ahmed M Musa,
Jenefer M Blackwell, Moawia M Mukhtar, Ahmed M Elhassan, Muntaser E Ibrahim

AFFILIATION: Institute of Endemic Diseases, University of Khartoum, P.O. Box
102, Khartoum, Sudan.

REFERENCE: Infect Genet Evol 2005 Jan 5(1):29-33

Mucosal leishmaniasis, which is a sporadic disease in the Sudan, was 
shown by isoenzyme characterization and PCR to be caused by Leishmania 
donovani. However, it was not clear if the parasite was exactly the same
 strain as that causing visceral leishmaniasis (VL), or of a different 
strain. We utilized a new generation of molecular DNA markers, 
minisatellites and kinetoplast DNA, for rapid characterization of the 
parasite. The results show that the genotypes of some of the parasites 
causing VL are different from those causing mucosal leishmaniasis. The L
. donovani isolates causing visceral disease, as well as post-kala-azar 
mucosal leishmaniasis (PKML), have been shown to possess characteristic 
haplotypes. However, sequencing of a portion of the cytochrome oxidase 
II (COII) gene indicates that the parasite that invades the oral mucosa 
is divergent from other parasites causing VL. It appears to possess 
features of a more ancestral parasite with pronounced sequence homology 
to L. major. This agrees with earlier studies where isolates of mucosal 
leishmaniasis have been shown to possess an isoenzyme profile distinct 
from L. donovani and a different geographical distribution, albeit often
 overlapping with that of L. donovani.








PMID: 15558191
 

TITLE: Aurapten, a coumarin with growth inhibition against Leishmania major
promastigotes.

AUTHORS: H B Napolitano, M Silva, J Ellena, B D G Rodrigues, A L C Almeida, P C
Vieira, G Oliva, O H Thiemann

AFFILIATION: Laboratório de Proteína, Cristalografia e Biologia Estructural,
Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos,
SP, Brasil.

REFERENCE: Braz J Med Biol Res 2004 Dec 37(12):1847-52

Several natural compounds have been identified for the treatment of 
leishmaniasis. Among them are some alkaloids, chalcones, lactones, 
tetralones, and saponins. The new compound reported here, 7-
geranyloxycoumarin, called aurapten, belongs to the chemical class of 
the coumarins and has a molecular weight of 298.37. The compund was 
extracted from the Rutaceae species Esenbeckia febrifuga and was 
purified from a hexane extract starting from 407.7 g of dried leaves and
 followed by four silica gel chromatographic fractionation steps using 
different solvents as the mobile phase. The resulting compound (47 mg) 
of shows significant growth inhibition with an LD50 of 30 microM against
 the tropical parasite Leishmania major, which causes severe clinical 
manifestations in humans and is endemic in the tropical and subtropical 
regions. In the present study, we investigated the atomic structure of 
aurapten in order to determine the existence of common structural motifs
 that might be related to other coumarins and potentially to other 
identified inhibitors of Leishmania growth and viability. This compound 
has a comparable inhibitory activity of other isolated molecules. The 
aurapten is a planar molecule constituted of an aromatic system with 
electron delocalization. A hydrophobic side chain consisting of ten 
carbon atoms with two double bonds and negative density has been 
identified and may be relevant for further compound synthesis.




PMID: 15567123
 

TITLE: Human genetics of intracellular infectious diseases: molecular and
cellular immunity against mycobacteria and salmonellae.

AUTHORS: Esther van de Vosse, Marieke A Hoeve, Tom H M Ottenhoff

AFFILIATION: Department of Infectious Diseases, Leiden University Medical
Centre, Leiden, Netherlands.

REFERENCE: Lancet Infect Dis 2004 Dec 4(12):739-49

The ability to develop adequate immunity to intracellular bacterial 
pathogens is unequally distributed among human beings. In the case of 
tuberculosis, for example, infection with Mycobacterium tuberculosis 
results in disease in 5-10% of exposed individuals, whereas the 
remainder control infection effectively. Similar interindividual 
differences in disease susceptibility are characteristic features of 
leprosy, typhoid fever, leishmaniasis, and other chronic infectious 
diseases, including viral infections. The outcome of infection is 
influenced by many factors, such as nutritional status, co-infections, 
exposure to environmental microbes, and previous vaccinations. It is 
clear, however, that genetic host factors also play an important part in
 controlling disease susceptibility to intracellular pathogens. Recently
, patients with severe infections due to otherwise poorly pathogenic 
mycobacteria (non-tuberculous mycobacteria or Mycobacterium bovis BCG) 
or Salmonella spp have been identified. Many of these patients were 
unable to produce or respond to interferon gamma, due to deleterious 
mutations in genes that encode major proteins in the type 1 cytokine (
interleukin 12/interleukin 23/interferon gamma) axis (interleukin 12p40/
interleukin 23p40, IL12 receptor beta1/IL23 receptor beta1, interferon 
gamma receptors 1 and 2, or signal transducer and activator of 
transcription 1). This axis is a major immunoregulatory system that 
bridges innate and adaptive immunity. Unusual mycobacterial infections 
were also reported in several patients with genetic defects in inhibitor
 of NFkappaB kinase gamma, a key regulatory molecule in the nuclear 
factor kappaB pathway. New findings discussed in this review provide 
further and sometimes surprising insights into the role of type 1 
cytokines, and into the unexpected heterogeneity seen in these syndromes.




PMID: 15546498
 

TITLE: Zinc/copper imbalance reflects immune dysfunction in human
leishmaniasis:
an ex vivo and in vitro study.

AUTHORS: Johan Van Weyenbergh, Gisélia Santana, Argemiro D'Oliveira, Anibal F
Santos, Carlos H Costa, Edgar M Carvalho, Aldina Barral, Manoel Barral-Netto

AFFILIATION: LIMI, Gonçalo Moniz Research Center -Oswaldo Cruz Foundation
(FIOCRUZ), Rua Waldemar Falcao 121, 40295-001 Salvador-BA, Brazil.
johan at cpqgm.fiocruz.br.

REFERENCE: BMC Infect Dis 2004 Nov 4(1):50

BACKGROUND: The process of elimination of intracellular pathogens, such 
as Leishmania, requires a Th1 type immune response, whereas a dominant 
Th2 response leads to exacerbated disease. Experimental human zinc 
deficiency decreases Th1 but not Th2 immune response. We investigated if
 zinc and copper levels differ in different clinical forms of 
leishmaniasis, and if these trace metals might be involved in the immune
 response towards the parasite. METHODS: Blood was collected from 31 
patients with either localized cutaneous (LCL), mucosal (ML) or visceral
 (VL) leishmaniasis, as well as from 25 controls from endemic and non-
endemic areas. Anti-Leishmania humoral and cellular immune response were
 evaluated by quantifying specific plasma IgG, lymphoproliferation and 
cytokine production, respectively. Plasma levels of Cu and Zn were 
quantified by atomic absorption spectrophotometry. RESULTS: A 
significant decrease in plasma Zn was observed in all three patient 
groups (p < 0.01 for LCL and ML, p < 0.001 for VL), as compared 
to controls, but only VL (7/10) and ML (1/7) patients displayed overt Zn
 deficiency. Plasma Cu was increased in LCL and VL (p < 0.001) but 
not in ML, and was strongly correlated to anti-Leishmania IgG (Spearman 
r = 0.65, p = 0.0028). Cu/Zn ratios were highest in patients with 
deficient cellular (VL<<LCL<ML) and exacerbated humoral (VL>
LCL>ML) immune response. Ex vivo production of parasite-induced IFN-
gamma was negatively correlated to plasma Cu levels in LCL (r = -0.57, p
 = 0.01). In vitro, increased Cu levels inhibited IFN-gamma production. 
CONCLUSIONS: 1. Zn deficiency in VL and ML indicate possible therapeutic
 administration of Zn in these severe forms of leishmaniasis. 2. Plasma 
Cu positively correlates to humoral immune response across patient 
groups. 3. Environmentally or genetically determined increases in Cu 
levels might augment susceptibility to infection with intracellular 
pathogens, by causing a decrease in IFN-gamma production.




PMID: 15559422
 

TITLE: Management of leishmanial osteolytic lesions in a hypothyroid dog by
partial tarsal arthrodesis.

AUTHORS: J Franch, J Pastor, E Torrent, P Lafuente, M C Diaz-Bertrana, A
Munilla, I Durall

AFFILIATION: Department of Surgery, Veterinary School, Autonomous University of
Barcelona, 08193 Bellaterra, Barcelona, Spain.

REFERENCE: Vet Rec 2004 Oct 155(18):559-62

A five-year-old male boxer, previously diagnosed with leishmaniasis and 
hypothyroidism, had gradually become unable to bear weight on its left 
hindlimb. Physical examination revealed a left popliteal lymphadenopathy
, mild crepitus, and severe swelling of the left tarsal joint, a 
radiographic examination of which revealed severe bone destruction of 
the talus and a periosteal reaction of the calcaneus. Laboratory 
findings and serological tests suggested an active leishmanial infection
, and a Leishmania species was identified by direct cytology of a sample
 from the osteolytic area and by indirect immunohistochemistry of a bone
 biopsy. The dog's condition improved when it was treated with meglumine
 antimonate and allopurinol. Because of the large osteolytic area and 
the increased use of the affected leg, a partial tarsal arthrodesis was 
performed to prevent a fracture. Five months after the surgery, the 
osteolytic area had healed completely and the calcaneus periosteal 
reaction had disappeared.








PMID: 15558165
 

TITLE: Feeding preference of the sand flies Lutzomyia umbratilis and L.
spathotrichia (diptera: Psychodidae, Phlebotominae) in an urban forest patch in
the city of Manaus, Amazonas, Brazil.

AUTHORS: Liliane Coelho da Rocha, Nery Elias S Lorosa, Antonia Maria Ramos
Franco

AFFILIATION: Laboratório de Leishmaniose e Doença de Chagas, Instituto
Nacional de Pesquisas da Amazônia, Manaus, AM, 69083, Brasil.

REFERENCE: Mem Inst Oswaldo Cruz 2004 Oct 99(6):571-4

Precipitin tests were performed on blood meals of 199 sand flies (161 
Lutzomyia umbratilis, 34 L. spathotrichia, two Lutzomyia of group 
shannoni, one L. anduzei) in a non-flooded upland forest on the Campus 
of the Universidade Federal do Amazonas. This is the second largest 
forest fragment in an urban setting in Brazil. Results on L. umbratilis
, which is considered to be the principal leishmaniasis vector in this 
region, indicated rodents as its predominant blood source in contrast to
 previous reports in which blood meal analysis indicated that this 
species fed principally on Xenarthra (particularly sloths).




REQUEST: [ leishmania ]

(18 articles match this request. 7 articles matching other requests removed)



PMID: 15556763
 

TITLE: Crystallographic and NMR studies of antiinfective tricyclic guanidine
alkaloids from the sponge Monanchora unguifera.

AUTHORS: Hui-Ming Hua, Jiangnan Peng, Frank R Fronczek, Michelle Kelly, Mark T
Hamann

AFFILIATION: Department of Pharmacognosy, School of Pharmacy, University of
Mississippi, University, MS 38677, USA; Chemistry Department, Louisiana State
University, Baton Rouge, LA 70803-1804, USA.

REFERENCE: Bioorg Med Chem 2004 Dec 12(24):6461-4

Three tricyclic guanidine alkaloids, including 1,8a;8b,3a-didehydro-
8beta-hydroxyptilocaulin (1), 1,8a;8b,3a-didehydro-8alpha-
hydroxyptilocaulin (2) and mirabilin B (3), were identified from the 
marine sponge Monanchora unguifera. 1,8a;8b,3a-Didehydro-8alpha-
hydroxyptilocaulin (2) is a new stereoisomer of 1, the structure of 
which was elucidated by spectroscopic analysis, comparison of its 
spectral data with those of 1, and confirmed by X-ray analysis. 
Compounds 1 and 2 co-crystallized in an unusual perfect order and packed
 around an approximate inversion center. A mixture of 1 and 2 is active 
against the malaria parasite Plasmodium falciparum with an IC(50) value 
of 3.8mug/mL while mirabilin B (3) exhibited antifungal activity against
 Cryptococcus neoformans with an IC(50) value of 7.0mug/mL and 
antiprotozoal activity against Leishmania donovani with an IC(50) value 
of 17mug/mL.




PMID: 15557613
 

TITLE: The Leishmania major LACK Antigen with an Immunodominant Epitope at
Amino
Acids 156 to 173 Is Not Required for Early Th2 Development in BALB/c Mice.

AUTHORS: Ben L Kelly, Richard M Locksley

AFFILIATION: UCSF Medical Center, Room C-443, 521 Parnassus Ave., San
Francisco,
CA 94143-0654. locksley at medicine.ucsf.edu.

REFERENCE: Infect Immun 2004 Dec 72(12):6924-31

The Leishmania major LACK antigen contains an immunodominant epitope at 
amino acids 156 to 173 (LACK(156-173)) that is believed to nucleate the 
pathological Th2 immune response in susceptible BALB/c mice. To test 
this hypothesis, we generated L. major parasites that express a mutated 
LACK that fails to activate Vbeta4/Valpha8 T-cell receptor transgenic T 
cells specific for this epitope. Although mutant parasites attenuated 
the expansion of endogenous LACK-specific, interleukin-4 (IL-4)-
expressing, CD4 T cells compared to wild-type parasites in vivo, the 
overall frequency of IL-4 and gamma interferon-secreting lymphocytes was
 similar to that elicited by wild-type L. major. Mutant parasites 
demonstrated diminished amastigote viability and delayed lesion 
development in mice, although parasites could be recovered over 200 days
 after infection. Complementation with a wild-type lack fusion construct
 partially rescued these defects, indicating a role for endogenous LACK 
in parasitism. Mice inoculated with mutant parasites were not protected 
against subsequent infection with wild-type L. major.




PMID: 15557638
 

TITLE: Characterization of a Defensin from the Sand Fly Phlebotomus duboscqi
Induced by Challenge with Bacteria or the Protozoan Parasite Leishmania major.

AUTHORS: Nathalie Boulanger, Carl Lowenberger, Petr Volf, Raul Ursic, Lucie
Sigutova, Laurence Sabatier, Milena Svobodova, Stephen M Beverley, Gerald
Späth, Reto Brun, Bernard Pesson, Philippe Bulet

AFFILIATION: INSERM U392, ULP, Faculté de Pharmacie, 67400 Illkirch, France.
nboulanger at aspirine.u-strasbg.fr.

REFERENCE: Infect Immun 2004 Dec 72(12):7140-6

Antimicrobial peptides are major components of the innate immune 
response of epithelial cells. In insect vectors, these peptides may play
 a role in the control of gut pathogens. We have analyzed antimicrobial 
peptides produced by the sand fly Phlebotomus duboscqi, after challenge 
by injected bacteria or feeding with bacteria or the protozoan parasite 
Leishmania major. A new hemolymph peptide with antimicrobial activity 
was identified and shown to be a member of the insect defensin family. 
Interestingly, this defensin exhibits an antiparasitic activity against 
the promastigote forms of L. major, which reside normally within the 
sand fly midgut. P. duboscqi defensin could be induced by both hemolymph
 or gut infections. Defensin mRNA was induced following infection by 
wild-type L. major, and this induction was much less following 
infections with L. major knockout mutants that survive poorly in sand 
flies, due to specific deficiencies in abundant cell surface 
glycoconjugates containing phosphoglycans (including lipophosphoglycan
). The ability of gut pathogens to induce gut as well as fat body 
expression of defensin raises the possibility that this antimicrobial 
peptide might play a key role in the development of parasitic infections.








PMID: 15557140
 

TITLE: Cutting edge: neutrophil granulocyte serves as a vector for leishmania
entry into macrophages.

AUTHORS: Ger van Zandbergen, Matthias Klinger, Antje Mueller, Sonja Dannenberg,
Andreas Gebert, Werner Solbach, Tamás Laskay

AFFILIATION: Institute for Medical Microbiology and Hygiene.

REFERENCE: J Immunol 2004 Dec 173(11):6521-5

Macrophages (MF) are the final host cells for multiplication of the 
intracellular parasite Leishmania major (L. major). However, 
polymorphonuclear neutrophil granulocytes (PMN), not MF, are the first 
leukocytes that migrate to the site of infection and encounter the 
parasites. Our previous studies indicated that PMN phagocytose but do 
not kill L. major. Upon infection with Leishmania, apoptosis of human 
PMN is delayed and takes 2 days to occur. Infected PMN were found to 
secrete high levels of the chemokine MIP-1beta, which attracts MF. In 
this study, we investigated whether MF can ingest parasite-infected PMN
. We observed that MF readily phagocytosed infected apoptotic PMN. 
Leishmania internalized by this indirect way survived and multiplied in 
MF. Moreover, ingestion of apoptotic infected PMN resulted in release of
 the anti-inflammatory cytokine TGF-beta by MF. These data indicate that
 Leishmania can misuse granulocytes as a "Trojan horse" to enter their 
final host cells "silently" and unrecognized.




PMID: 15554964
 

TITLE: A potential role for ICP, a leishmanial inhibitor of cysteine
peptidases,
in the interaction between host and parasite.

AUTHORS: Sébastien Besteiro, Graham H Coombs, Jeremy C Mottram

AFFILIATION: Wellcome Centre for Molecular Parasitology, The Anderson College,
University of Glasgow, Glasgow G11 6NU, UK.

REFERENCE: Mol Microbiol 2004 Dec 54(5):1224-36

Summary The biological role of a natural inhibitor of cysteine 
peptidases (designated ICP) of Leishmania has been investigated by 
genetic manipulation of the parasite. Null mutants grew normally in 
vitro, were as infective to macrophages in vitro as wild-type parasites
, but had reduced infectivity to mice. Mutants re-expressing ICP from a 
single gene gave partial restoration of virulence in vivo, whereas 
mutants overexpressing ICP secreted the inhibitor and showed markedly 
reduced virulence in mice. Promastigotes of the null mutants had similar
 cysteine peptidase activities as the wild-type parasites, suggesting 
that ICP is not required for the expression or processing of the enzymes
. The only proteins found to bind to ICP in promastigote cell lysates 
were fully processed forms of CPA and CPB, showing that ICP does not 
bind in abundance either to zymogens of the cysteine peptidases or other
 leishmanial proteins. However, only a small proportion of ICP 
colocalized with CPA and CPB in the promastigote (in the endoplasmic 
reticulum and Golgi) and the majority of ICP resided in vesicles that 
are apparently distinct from endosomes and the multivesicular tubule (
MVT)-lysosome. These data suggest that ICP has a role other than 
modulation of the activity of the parasite's own cysteine peptidases and
 their normal trafficking to the MVT-lysosome via the flagellar pocket. 
The finding that ICP partially colocalized with an endocytosed cysteine 
peptidase leads us to postulate that ICP has a role in protection of the
 parasite against the hydrolytic environment of the sandfly gut and/or 
the parasitophorous vacuole of host macrophages.




PMID: 15555938
 

TITLE: Overexpression in Escherichia coli and purification of pteridine
reductase (PTR1) from a clinical isolate of Leishmania donovani.

AUTHORS: Pranav Kumar, Hema Kothari, Neeloo Singh

AFFILIATION: Drug Target Discovery and Development Division, Central Drug
Research Institute, Lucknow, India.

REFERENCE: Protein Expr Purif 2004 Dec 38(2):228-36

Pteridine reductase 1 (PTR1) is part of a novel metabolic pathway in 
Leishmania associated with folate metabolism. Its main function is to 
salvage pterins but a second one is to reduce folates. The novelty and 
possible uniqueness of the pathway in which PTR1 is involved opens the 
possibility of developing specific inhibitors, which in combination with
 dihydrofolate reductase inhibitors could be highly effective against 
Leishmania. In order to increase our understanding of this putative 
important chemotherapeutic target, we present here the cloning, 
overexpression and purification of this enzyme from a clinical isolate 
of Leishmania donovani causing kala azar in India. This recombinant 
enzyme will set the basis for inhibition studies as well as for 
structure-function relationships.




PMID: 15516924
 

TITLE: Deletion of a conserved Il4 silencer impairs T helper type 1-mediated
immunity.

AUTHORS: K Mark Ansel, Rebecca J Greenwald, Suneet Agarwal, Craig H Bassing,
Silvia Monticelli, Jeneen Interlandi, Ivana M Djuretic, Dong U Lee, Arlene H
Sharpe, Frederick W Alt, Anjana Rao

AFFILIATION: Department of Pathology, Harvard Medical School, Boston,
Massachusetts 02115, USA.

REFERENCE: Nat Immunol 2004 Dec 5(12):1251-9

Helper T cell differentiation involves silencing as well as activation 
of gene expression. We have identified a conserved silencer of the gene 
encoding interleukin 4 (Il4) marked by DNase I hypersensitivity (HS IV) 
and permissive chromatin structure in all helper T cells. Deletion of HS
 IV increased Il4 and Il13 transcription by naive T cells and led to T 
helper type 2 skewing in vitro. HS IV controlled Il4 silencing during T 
helper type 1 differentiation, as HS IV-deficient T helper type 1 cells 
that expressed interferon-gamma also produced abundant interleukin 4 in 
vitro and in vivo. Despite mounting a vigorous interferon-gamma response
, HS IV-deficient mice were more susceptible to Leishmania major 
infection than were wild-type littermate control mice, showing a 
critical function for Il4 silencing in T helper type 1-mediated immunity.








PMID: 15558171
 

TITLE: Life tables and reproductive parameters of Lutzomyia spinicrassa
(Diptera: Psychodidae) under laboratory conditions.

AUTHORS: Jesús Escovar, Felio J Bello, Alberto Morales, Ligia Moncada,
Estrella
Cárdenas

AFFILIATION: Laboratorio de Entomología, Biología Celular y Genética,
Departamento de Ciencias Básicas, Universidad de La Salle, Bogotá, DC,
Colombia.

REFERENCE: Mem Inst Oswaldo Cruz 2004 Oct 99(6):603-7

Lutzomyia spinicrassa is a vector of Leishmania braziliensis in Colombia
. This sand fly has a broad geographical distribution in Colombia and 
Venezuela and it is found mainly in coffee plantations. Baseline 
biological growth data of L. spinicrassa were obtained under 
experimental laboratory conditions. The development time from egg to 
adult ranged from 59 to 121 days, with 12.74 weeks in average. Based on 
cohorts of 100 females, horizontal life table was constructed. The 
following predictive parameters were obtained: net rate of reproduction
 (8.4 females per cohort female), generation time (12.74 weeks), 
intrinsic rate of population increase (0.17), and finite rate of 
population increment (1.18). The reproductive value for each class age 
of the cohort females was calculated. Vertical life tables were 
elaborated and mortality was described for the generation obtained of 
the field cohort. In addition, for two successive generations, additive 
variance and heritability for fecundity were estimated.




PMID: 15562617
 

TITLE: Quantification of Leishmania infantum parasites in tissue biopsies by
real-time polymerase chain reaction and polymerase chain reaction-enzyme-linked
immunosorbent assay.

AUTHORS: N Rolão, S Cortes, O R Rodrigues, L Campino

AFFILIATION: Unidade de Leishmanioses, Centro Malaria Outras Doenças
Tropicais,
Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da
Junqueira 96, 1349-008 Lisbon, Portugal.

REFERENCE: J Parasitol 2004 Oct 90(5):1150-4

Most of the experimental studies of Leishmania spp. infection require 
the determination of the parasite load in different tissues. 
Quantification of parasites by microscopy is not very sensitive and is 
time consuming, whereas culture microtitrations remain laborious and can
 be jeopardized by microbial contamination. The aim of this study was to
 quantify Leishmania infantum parasites by real-time polymerase chain 
reaction (PCR) using specific DNA TaqMan probes and to compare the 
efficacy of detection of this technique with a PCR-enzyme-linked 
immunosorbent assay (ELISA). For this purpose, spleen and liver samples 
from L. infantum-infected mice were collected during a 3-mo longitudinal
 study and analyzed by both methods. PCR-ELISA failed to quantify 
Leishmania spp. DNA in samples with very low or very high numbers of 
parasites. Real-time PCR was more sensitive than PCR-ELISA, detecting 
down to a single parasite, and enabled the parasite quantification over 
a wide, 5-log range. In summary, this study developed a method for 
absolute quantification of L. infantum parasites in infected organs 
using real-time TaqMan PCR.




PMID: 15562618
 

TITLE: Inhibition of Leishmania donovani promastigote DNA topoisomerase I and
human monocyte DNA topoisomerases I and II by antimonial drugs and classical
antitopoisomerase agents.

AUTHORS: John Walker, Nancy G Saravia

AFFILIATION: Centro Internacional de Entrenamiento e Investigaciones Medicas
Avenida 1 Norte No. 3-03, AA 5390, Cali, Colombia. john_walker at cideim.org.co

REFERENCE: J Parasitol 2004 Oct 90(5):1155-62

We have compared the inhibitor sensitivities of DNA topoisomerase I (
TOPI) from Leishmania donovani promastigotes and TOPs I and II of human 
monocytes using pentavalent and trivalent antimonials (SbV, SbIII) and 
classical TOP inhibitors. Bis-benzimidazoles (Hoechst-33258 and -33342) 
were potent inhibitors of both parasite and human TOPI, but Hoechst-
33342 was markedly less cytotoxic to promastigotes than to monocytes in 
vitro. Leishmania donovani was also considerably less sensitive than 
monocytes to camptothecin, both at enzyme and cellular levels. Sodium 
stibogluconate (SSG) was the only antimonial to inhibit TOPI, exhibiting
 a significant (P < 0.05) 3-fold greater potency against the L. 
donovani enzyme but showed low cytotoxicities against intact 
promastigotes. The SbV meglumine antimoniate failed to inhibit TOPI and 
showed negligible cytotoxicities, whereas SbIII drugs were lethal to 
parasites and monocytes yet poor inhibitors of TOPI. Monocyte TOPII was 
inhibited by bis-benzimidazoles and insensitive to antimonials and 
camptothecin. The disparity between the high leishmanicidal activity and
 low anti-TOPI potency of SbIII indicates that in vivo targeting of L. 
donovani TOPI by the reductive pathway of antimonial activation is 
improbable. Nevertheless, the potent direct inhibition of TOPI by SSG 
and the differential interactions of camptothecin with L. donovani and 
human TOPI support the possibility of developing parasite-specific 
derivatives.




PMID: 15558170
 

TITLE: Biology of the first generation of a laboratory colony of Nyssomyia
intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926)
(Diptera: Psychodidae).

AUTHORS: José Dilermando Andrade Filho, Eunice A Bianchi Galati, Alda Lima
Falcão

AFFILIATION: Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo
Horizonte, MG, 30190-002, Brasil.

REFERENCE: Mem Inst Oswaldo Cruz 2004 Oct 99(6):597-601

The phlebotomine sand flies Nyssomyia intermedia (Lutz & Neiva, 1912
) and Nyssomyia neivai (Pinto, 1926) are very close and may be involved 
in the transmission of Leishmania spp. Ross, 1903 in Brazil. The biology
 of the first laboratory-reared generations of these species, descended 
from insects captured in Alem Paraiba (N. intermedia) and Corinto (N. 
neivai) in the Brazilian state of Minas Gerais, is described here. The 
captured females were fed on hamsters and maintained individually in 
rearing pots. Laboratory temperature and relative humidity were 
maintained at 25-26 masculineC and 80% respectively. The productivity of
 the first generation of N. intermedia was greater than that of N. 
neivai, and its development time clearly shorter, particularly for the 
second and third larval instars.




REQUEST: [ sand fly ]

(5 articles match this request. 4 articles matching other requests removed)



PMID: 15558172
 

TITLE: Description of Micropygomyia (Silvamyia) echinatopharynx sp. nov.
(Diptera: Psychodidae) a new species of phlebotomine sand fly from the State of
Tocantins, Brazil.

AUTHORS: José Dilermando Andrade Filho, Eunice A Bianchi Galati, Welton Aires
de Andrade, Alda Lima Falcão

AFFILIATION: Laboratório de Leishmanioses, Centro de Pesquisas René Rachou,
Fundação Oswaldo Cruz, Belo Horizonte, MG, 30190-002, Brasil.

REFERENCE: Mem Inst Oswaldo Cruz 2004 Oct 99(6):609-15

During a study of the phlebotomines of the Brazilian state of Tocantins
, a new species was discovered in Porto Nacional county, here described 
as Micropygomyia (Silvamyia) echinatopharynx sp. nov. This is only the 
second species of the subgenus Micropygomyia (Silvamyia) to be described.




REQUEST: [ sandfly ]

(1 article matches this request. 1 article matching other requests removed)














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