Thursday, April 16, 2009

What's new for 'Trypanosomatids' in PubMed

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Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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PubMed Results
Items 1 -7 of 7

1: Turkiye Parazitol Derg. 2009;33(1):8-14.Click here to read

Determination of High Risk Regions of Cutaneous Leishmaniasis in Turkey Using Spatial Analysis.

Demırel R, Erdoğan S.

Afyon Kocatepe Universitesi Tip Fakültesi Halk Sağliği Anabilim Dali, Afyonkarahisar, Turkey.

The aim of this study was to use geographical analysis to determine the distribution of cutaneous leishmaniasis among the provinces of Turkey, as well as detection of the presence of any regional clustering in Turkey using spatial analyses. Geographic information systems based spatial analyses were performed on cutaneous leishmaniasis cases recorded by the Turkish Ministry of Health during the period from 1988-2006. Spatial analyses, including local and global spatial autocorrelation methods and clustering analysis were performed on the cutaneous leishmaniasis cases (1996-2006), to detect any trend or cluster and any particular province. The spatial distribution of cutaneous leishmaniasis cases was nonrandom and found to be clustered significantly (p < 0.05). There is a clear trend toward the southeast region. Regions with high concentration of cutaneous leishmaniasis are located in the southeast region (p < 0.05). This study shows that cutaneous leishmaniasis is a serious public health concern in the southeast region of Turkey, and that region should have a priority in the implement of precautionary measures. It also shows that spatial analyses and statistics can contribute to the understanding of the epidemiology of diseases and in identification of high rate disease locations.

PMID: 19367539 [PubMed - as supplied by publisher]

2: Turkiye Parazitol Derg. 2009;33(1):4-7.Click here to read

[Investigating the seroprevalance of leishmaniasis in four dog shelters in antalya and its districts.]

[Article in Turkish]

Balcioğlu IC, Ertabaklar H, Paşa S, Ozbel Y, Toz SO.

Celal Bayar Universitesi Tip Fakültesi, Parazitoloji Bilim Dali, Manisa, Turkey.

Human visceral leishmaniasis (HVL) is endemic along the Aegean and Mediterranean coasts, while it occurs sporadically in other regions of Turkey. A relationship between canine leishmaniasis (CanL) and HVL has been detected and dogs have been found to be the reservoir of Leishmania infantum. In this epidemiologic study, the seroprevalence of CanL was investigated in dog shelters of four districts (Kepez, Kemer, Alanya and Gazipasa) of Antalya, in which visceral leishmaniasis and cutaneous leishmaniasis were observed according to the official records of The Ministry of Health of Turkey. Blood specimens of 176 dogs were examined and seropositive, borderline, seropositive, and negative results were detected in 14 (7.95%), 24 (13.63%), and 138 (78.4%) dogs, respectively. Weight and alopecia, onychogryphosis, and skin ulcers around the nose were observed in only two (14.2 %) dogs of seropositive cases. In conclusion, our data indicate that there is a potential danger for humans because L. infantum carrying dogs were detected in four districts of Antalya in the present study and also the appropriate vector spp. for this parasite has been reported in a previous one. Therefore, it would be advisable to perform new studies in order to determine the seroprevalence of CanL in dogs and the population size of vector spp. of L. infantum in other districts of Antalya.

PMID: 19367538 [PubMed - in process]

3: J Biol Chem. 2009 Apr 14. [Epub ahead of print]Click here to read

An acid-activated nucleobase transporter from Leishmania major.

Ortiz D, Sanchez MA, Koch HP, Larsson HP, Landfear SM.

Oregon Health & Science University, United States;

Parasitic protozoa are unable to synthesize purines de novo and must import preformed purine nucleobases or nucleosides from their hosts. Leishmania major expresses two purine nucleobase transporters, LmaNT3 and LmaNT4. Previous studies revealed that at neutral pH, LmaNT3 is a broad specificity, high affinity nucleobase transporter, whereas LmaNT4 mediates the uptake only of adenine. Since LmaNT4 is required for optimal viability of the amastigote stage of the parasite that lives within acidified phagolysomal vesicles of mammalian macrophages, the function of this permease was examined under acidic pH conditions. At acid pH, LmaNT4 acquires the ability to transport adenine, hypoxanthine, guanine, and xanthine with Km values in the micromolar range, indicating that this transporter is activated at low pH. Thus LmaNT4 is an acid-activated purine nucleobase transporter that functions optimally under the physiological conditions the parasite is exposed to in the macrophage phagolysosome. In contrast, LmaNT3 functions optimally at neutral pH. Two-electrode voltage clamp experiments performed on LmaNT3 and LmaNT4 expressed in Xenopus oocytes revealed substrate induced inward directed currents at acid pH, and application of substrates induced acidification of the oocyte cytosol. These observations imply that LmaNT3 and LmaNT4 are nucleobase/proton symporters.

PMID: 19366701 [PubMed - as supplied by publisher]

4: Biochim Biophys Acta. 2009 Jan 21. [Epub ahead of print]Click here to read

Bombinins, antimicrobial peptides from Bombina species.

Simmaco M, Kreil G, Barra D.

Istituto Pasteur-Fondazione Cenci Bolognetti, CNR Istituto di Biologia e Patologia Molecolari, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Azienda Ospedaliera S. Andrea, Università La Sapienza, I-00185 Rome, Italy.

The skin secretions of Bombina species contain peptides and small proteins with interesting biological properties, These include bombesin, thyrotropin releasing hormone, BSTI and Bv8. In this review, the biosynthesis and antimicrobial activity of two groups of peptides, bombinins and bombinins H, are described. To date, these have only been found in Bombina skin. They are derived from common precursors containing one or two bombinin copies at the amino and a single bombinin H at the carboxyl end. Bombinins are active against Gram-positive and Gram-negative bacteria and fungi but virtually inactive in haemolysis assays. Conversely, bombinins H have lower bactericidal activities but lyse erythrocytes. In the skin secretions, bombinins H are present in two sizes with either 20 or 17 amino acids. Moreover, they occur as epimers with either an L- or a D-amino acid at position 2. An enzyme catalyzing this inversion of chirality of an amino acid in peptide linkage has been isolated from Bombina skin secretions. In different tests, also with different stages of the life cycle of Leishmania parasites, the D-forms were found to be more active. Biophysical studies have yielded some insight into the different behaviour of the epimers in model membranes.

PMID: 19366600 [PubMed - as supplied by publisher]

5: Nucleic Acids Res. 2009 Apr;37(5):1452-62. Epub 2009 Jan 9.Click here to read Click here to read References for this PMC Article, Free in PMC, LinkOut

JBP1 and JBP2 are two distinct thymidine hydroxylases involved in J biosynthesis in genomic DNA of African trypanosomes.

Cliffe LJ, Kieft R, Southern T, Birkeland SR, Marshall M, Sweeney K, Sabatini R.

Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA.

Genomic DNA of African trypanosomes contains a hypermodified thymidine residue termed base J (beta-d-glucosyl-HOMedU). This modified base is localized primarily to repetitive DNA, namely the telomeres, and is implicated in the regulation of antigenic variation. The base is synthesized in a two-step pathway. Initially, a thymidine residue in DNA is hydroxylated by a thymidine hydroxylase (TH). This intermediate (HOMedU) is then glucosylated to form base J. Two proteins involved in J synthesis, JBP1 (J binding protein 1) and JBP2, contain a putative TH domain related to the family of Fe(2+)/2-oxoglutarate-dependent hydroxylases. We have previously shown that mutations in the TH domain of JBP1 kill its ability to stimulate J synthesis. Here we show that mutation of key residues in the TH domain of JBP2 ablate its ability to induce de novo J synthesis. While the individual JBP1 null and JBP2 null trypanosomes have reduced J levels, the deletion of both JBP1 and JBP2 generates a cell line that completely lacks base J but still contains glucosyl-transferase activity. Reintroduction of JBP2 in the J-null trypanosome stimulates HOMedU formation and site-specific synthesis of base J. We conclude that JBP2 and JBP1 are the TH enzymes involved in J biosynthesis.

PMID: 19136460 [PubMed - indexed for MEDLINE]

PMCID: PMC2655668

6: Rev Soc Bras Med Trop. 2008 Sep-Oct;41(5):520-1.Click here to read LinkOut

Meningoencephalitis in a patient with acute Chagas disease in the Brazilian Amazon.

Medeiros MB, Guerra JA, Lacerda MV.

Fundação de Medicina Tropical do Amazonas, Manaus, AM.

PMID: 19009201 [PubMed - indexed for MEDLINE]

7: Rev Inst Med Trop Sao Paulo. 2008 Jul-Aug;50(4):243-9.Click here to read LinkOut

Astrocytic and microglial response and histopathological changes in the brain of horses with experimental chronic Trypanosoma evansi infection.

Lemos KR, Marques LC, Aquino LP, Alessi AC, Zacarias RZ.

Departamento de Medicina Veterinária, UNICENTRO, Guarapuava, PR, Brasil. krlemos@yahoo.com.br

This study aimed to characterize astrocytic and microglial response in the central nervous system (CNS) of equines experimentally infected with T. evansi. The experimental group comprised males and females with various degrees of crossbreeding, ages between four and seven years. The animals were inoculated intravenously with 10(6) trypomastigotes of T. evansi originally isolated from a naturally infected dog. All equines inoculated with T. evansi were observed until they presented symptoms of CNS disturbance, characterized by motor incoordination of the pelvic limbs, which occurred 67 days after inoculation (DAI) and 124 DAI. The animals in the control group did not present any clinical symptom and were observed up to the 125th DAI. For this purpose the HE histochemical stain and the avidin biotin peroxidase method was used. Lesions in the CNS of experimentally infected horses were those of a wide spread non suppurative meningoencephalomyelitis.The severity of lesions varied in different parts of the nervous system, reflecting an irregular distribution of inflammatory vascular changes. The infiltration of mononuclear cells was associated with anisomorphic gliosis and reactive microglia was identified. The intensity of the astrocytic response in the CNS of the equines infected by T. evansi characterizes the importance of the performance of these cells in this trypanosomiasis. The characteristic gliosis observed in the animals in this experiment suggests the ability of these cells as mediators of immune response. The parasite, T. evansi, was not identified in the nervous tissues.

PMID: 18813766 [PubMed - indexed for MEDLINE]

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