[leish-l] Fwd: Articles found by RefScout 49/2004-01/12/2004
jeffreyj at usp.br
jeffreyj at usp.br
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 ProteÃna, Cristalografia e Biologia Estructural,
Instituto de FÃsica 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 EntomologÃa, BiologÃa 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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