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1.
Parasitol Res ; 123(3): 166, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38506929

ABSTRACT

The hemoparasite Trypanosoma equiperdum belongs to the Trypanozoon subgenus and includes several species that are pathogenic to animals and humans in tropical and subtropical areas across the world. As with all eukaryotic organisms, Ca2+ is essential for these parasites to perform cellular processes thus ensuring their survival across their life cycle. Despite the established paradigm to study proteins related to Ca2+ homeostasis as potential drug targets, so far little is known about Ca2+ entry into trypanosomes. Therefore, in the present study, the presence of a plasma membrane Ca2+-channel in T. equiperdum (TeCC), activated by sphingosine and inhibited by verapamil, is described. The TeCC was cloned and analyzed using bioinformatic resources, which confirmed the presence of several domains, motifs, and a topology similar to the Ca2+ channels found in higher eukaryotes. Biochemical and confocal microscopy assays using antibodies raised against an internal region of human L-type Ca2+ channels indicate the presence of a protein with similar predicted molar mass to the sequence analyzed, located at the plasma membrane of T. equiperdum. Physiological assays based on Fura-2 signals and Mn2+ quenching performed on whole parasites showed a unidirectional Ca2+ entry, which is activated by sphingosine and blocked by verapamil, with the distinctive feature of insensitivity to nifedipine and Bay K 8644. This suggests a second Ca2+ entry for T. equiperdum, different from the store-operated Ca2+ entry (SOCE) previously described. Moreover, the evidence presented here for the TeCC indicates molecular and pharmacological differences with their mammal counterparts, which deserve further studies to evaluate the potential of this channel as a drug target.


Subject(s)
Sphingosine , Trypanosoma , Animals , Humans , Sphingosine/pharmacology , Verapamil/pharmacology , Cell Membrane/metabolism , Calcium/metabolism , Mammals
2.
Vet Res Commun ; 48(3): 1891-1898, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38369611

ABSTRACT

Trypanosomosis is a tropical disease caused by various protozoan haemoparasites, which affects wild and domestic animals, the latter ones related to worldwide livestock production systems. Species such as Trypanosoma vivax and Trypanosoma evansi have been described using serological and molecular tools in several countries from South and Central America. However, Ecuador presents a relevant knowledge gap in the associated general epidemiology and risk factors of the disease. Therefore, the objective of this study was to determine the seroprevalence of trypanosomosis in cattle from different regions of Ecuador. 745 serum samples from 7 Coastal and 3 Amazon provinces were screened for IgG anti-Trypanosoma spp. antibodies, using an in-house indirect ELISA. The seropositivity was explored and associated with several variables such as sex, age, breed, region, management, and province, using statistical tools. The general seroprevalence of trypanosomosis was 19.1% (95% CI: 16.30-22.1%). The Amazonian provinces of Sucumbíos and Napo and the Coastal province of Esmeraldas presented the highest seroprevalence values of 36.7% (95% CI: 27.67-46.47%), 23.64% (95% CI: 16.06-32.68%) and 25% (95% CI: 15.99-35.94%), respectively. Statistical significance was found for the region, province, and management variables, indicating as relevant risk factors the extensive management and Amazon location of the cattle analyzed. Specific actions should be taken to identify the exact species on reservoirs and susceptible hosts, evaluate the implication of farm management and cattle movement as risk factors, and implement surveillance and treatment plans for affected herds.


Subject(s)
Trypanosoma , Animals , Cattle , Seroepidemiologic Studies , Ecuador/epidemiology , Risk Factors , Female , Male , Trypanosoma/isolation & purification , Cattle Diseases/epidemiology , Cattle Diseases/parasitology , Cattle Diseases/blood , Trypanosomiasis, Bovine/epidemiology , Trypanosomiasis, Bovine/blood , Trypanosomiasis/veterinary , Trypanosomiasis/epidemiology , Trypanosomiasis/parasitology , Antibodies, Protozoan/blood , Enzyme-Linked Immunosorbent Assay/veterinary
3.
Ecotoxicology ; 32(3): 309-320, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36928692

ABSTRACT

Imazethapyr, a post-emergent herbicide used in worldwide soybean and corn crops, induces genetic and biochemical alterations in aquatic vertebrates. This study examined the relationship between biomarkers at different organization levels and imazethapyr real-life route exposure in Boana pulchella adults. Frogs were exposed to imazethapyr-based formulation Pivot® H (10.59%) at concentrations representing possible acute routes: field runoff (S1:10 mg.L-1), exposure after direct foliar application (S2:100 mg.L-1) and during direct foliar application (S3:1000 mg.L-1). Post-exposure, endpoints levels were evaluated: organism alterations, biochemical activities and cytogenetic assays. Forty-eight hours post-exposure, antioxidant enzymes decrease, micronuclei induction and DNA damage were observed in all scenarios, while cholinesterase activity increase and body condition reduction were observed in frog-exposed to S3. Ninety-six hours post-exposure, frogs showed glutathione-S-transferase inhibition in S1, micronuclei induction in S2 and S3, and DNA-damage increase in S3. Herbicides routes of exposures in real-life could indicate that authorized applications have a risk to amphibian populations.


Subject(s)
Herbicides , Pesticides , Water Pollutants, Chemical , Animals , Anura , Pesticides/toxicity , Larva , Herbicides/toxicity , Biomarkers , Water Pollutants, Chemical/toxicity
4.
Vet Parasitol Reg Stud Reports ; 37: 100824, 2023 01.
Article in English | MEDLINE | ID: mdl-36623904

ABSTRACT

Trypanosoma theileri is a cosmopolitan opportunistic haemoparasite described in wild and domestic ruminants, and also in arthropod vectors. The presence of this parasite has been reported in several South American countries, including Amazonian regions. Despite the importance of livestock production, Ecuador possesses scarce studies about trypanosomosis and no T. theileri reports in its territory. Here, we showed molecular evidences of the presence of T. theileri in cattle from a province located in the Ecuadorian Amazon. Bovine blood samples were collected from 2014 to 2019, during campaigns to detect haemoparasites in the Ecuadorian provinces of Orellana and Sucumbíos. DNA was extracted from the buffy coat and used in PCR assays with three different molecular markers, ITS1, 18S and Cathepsin L-like. T. theileri was detected only in the Sucumbíos province, with a specific molecular prevalence of 8.6% (3/35) using the three primers and an additional animal detected as positive (11.4% prevalence) only by the ITS1 marker. DNA sequences derived from the generated amplicons were subjected to phylogenetics maximum parsimony and maximum likelihood analysis, which indicate the presence of TthI and TthII genotypes circulating in the evaluated animals. Molecular surveillance should be continually implemented in Ecuador in order to deepen the epidemiological and evolutionary knowledge about T. theileri as well other haemoparasites in the amazon parts of the country.


Subject(s)
Cattle Diseases , Trypanosoma , Trypanosomiasis , Cattle , Animals , Ecuador/epidemiology , Cattle Diseases/parasitology , Trypanosoma/genetics , Trypanosomiasis/epidemiology , Trypanosomiasis/veterinary , Trypanosomiasis/parasitology , Ruminants
5.
Vet Parasitol Reg Stud Reports ; 25: 100594, 2021 07.
Article in English | MEDLINE | ID: mdl-34474787

ABSTRACT

Trypanosoma vivax is a protozoan parasite that causes trypanosomosis in ruminants and is widely distributed in tropical areas in the world. The control of this disease depends on the sensitivity and specificity of the diagnostic tests implemented for naturally infected samples, where parasitaemias are usually low. This study aimed to evaluate the analytical sensitivity and specificity of several primers for T. vivax detection in experimental infections and their implementation for the diagnosis of trypanosomosis in naturally infected bovine and ovine samples. Using a T. vivax Venezuelan isolate, five sets of primers were evaluated: TviSL1/2, ITS1CF/BR, TVMF/R, ILO1264/1265, TVWA/B. Additionally, we tested the PCR protocols using different DNA quantities. The best set of primers (ILO1264/1265) was used to detect T. vivax DNA from whole blood and buffy coat samples of 12 sheep (ovine) and 45 cattle (bovine) of small farms from Venezuela, and compared to the micro-haematocrite centrifugation technique (MHCT). The highest sensitivity was 0.0001 ng for ILO1264/1265 and TVWA/B primers. Using 100 ng of DNA extracted from the buffy coat and the ILO1264/1265 primers for trypanosomosis diagnosis from naturally infected samples, yielded 66.7% (8/12) and 35.7% (16/45) positives in ovine and bovine respectively. The percentage of positives samples increased to 83.3% (10/12) and 64.4% (29/45), with 300 ng in the assays. Contrary, using 300 ng of DNA extracted from the whole blood yielded only 50% (6/12) and 28.9% (13/45) of positives samples for T. vivax respectively. MHCT only detected the parasite in bovine samples with 17.8% (8/45) of positives. Based on our results, we recommend the use of the ILO1264/1265 primers and 300 ng of DNA extracted from the buffy coat for epidemiological studies of naturally infected animals. Moreover, detection of the parasite in ovine herds highlights a possible role of this host in the epidemiology of trypanosomosis in Venezuela.


Subject(s)
Cattle Diseases , Sheep Diseases , Trypanosomiasis, Bovine , Animals , Cattle , Cattle Diseases/diagnosis , Cattle Diseases/epidemiology , DNA, Protozoan/analysis , Polymerase Chain Reaction/veterinary , Ruminants , Sheep , Sheep Diseases/diagnosis , Sheep Diseases/epidemiology , Sheep Diseases/parasitology , Trypanosoma vivax/genetics , Trypanosomiasis, Bovine/diagnosis , Trypanosomiasis, Bovine/epidemiology , Trypanosomiasis, Bovine/parasitology , Venezuela
6.
Arch Environ Contam Toxicol ; 81(3): 492-506, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34406426

ABSTRACT

Imazethapyr is an herbicide that is used in a variety of crops worldwide, including soybean and corn. The aim of the present study was to evaluate the biomarkers responses of adult Leptodactylus latinasus exposed to the formulation Pivot® H (10.59% imazethapyr) in the laboratory at concentrations and under conditions that simulate two potential field exposure scenarios: an immersion in field runoff (Scenario 1: 10 mg/L) and a direct exposure to the droplets emitted by spray noozles (Scenario 2: 1000 mg/L). In both scenarios, the experimental procedure involved completely immersing the frogs over a period of 15 s. Different endpoints were evaluated at several ecotoxicological levels 48 and 96 h after the herbicide exposure. These included individual (biometric indices and behavior alterations), histological (liver pigments and lesions), biochemical (catalase, glutathione system and cholinesterase activities) and genotoxic effects (micronuclei induction and nuclear abnormalities). Forty-eight hours after imazethapyr exposure, frogs submitted to Scenario 1 presented an inhibition of liver glutathione-S-transferase activity, whereas histological alterations and increased hepatic cholinesterase levels were observed in frogs exposed under Scenario 2. Ninety-six hours after exposure to the imazethapyr formulation, frogs from the Scenario 1 treatment presented a decrease in liver melanin and hemosiderin, increased hepatic catalase activity and micronuclei induction. For their part, frogs exposed to Scenario 2 presented a decrease in the hepatosomatic index, an increase in liver alterations, melanin reduction and micronuclei induction. The multivariate analysis enables correlations to be made between biomarkers of different organizational level in exposed anurans. Our result indicates that real exposure to imazethapyr formulations under field conditions may pose a risk to Leptodactylus latinasus populations living in the agroecosystems.


Subject(s)
Herbicides , Nicotinic Acids , Animals , Anura , DNA Damage , Herbicides/toxicity
7.
Clin Transl Oncol ; 22(8): 1272-1279, 2020 Aug.
Article in English | MEDLINE | ID: mdl-31863354

ABSTRACT

PURPOSE: There is a gap in knowledge regarding the impact of micrometastases (MIC) and isolated tumor cells (ITCs) found in the sentinel lymph nodes of patients with endometrial cancer. Here, we present a meta-analysis of the published literature on the rate of MIC and ITCs after lymphatic mapping and determine trends in postoperative management. METHODS: Literature search of Medline and PubMed was done using the terms: micrometastases, isolated tumor cells, endometrial cancer, and sentinel lymph node. Inclusion criteria were: English-language manuscripts, retrospectives, or prospective studies published between January 1999 and June 2019. We removed manuscripts on sentinel node mapping that did not specify information on micrometastases or isolated tumor cells, non-English-language articles, no data about oncologic outcomes, and articles limited to ten cases or less. RESULTS: A total of 45 manuscripts were reviewed, and 8 studies met inclusion criteria. We found that the total number of patients with MIC/ITCs was 286 (187 and 99, respectively). The 72% of patients detected with MIC/ITCs in sentinel nodes received adjuvant therapies. The MIC/ITCs group has a higher relative risk of recurrence of 1.34 (1.07, 1.67) than the negative group, even if the adjuvant therapy was given. CONCLUSION: We noted that there is an increased relative risk of recurrence in patients with low-volume metastases, even after receiving adjuvant therapy. Whether adjuvant therapy is indicated remains a topic of debate because there are other uterine factors implicated in the prognosis. Multi-institutional tumor registries may help shed light on this important question.


Subject(s)
Endometrial Neoplasms/pathology , Neoplasm Micrometastasis/pathology , Neoplasm Recurrence, Local , Sentinel Lymph Node Biopsy , Sentinel Lymph Node/pathology , Female , Humans , Prospective Studies , Retrospective Studies , Sentinel Lymph Node Biopsy/statistics & numerical data
8.
J Parasit Dis ; 41(2): 450-458, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28615858

ABSTRACT

In South America Trypanosoma evansi has been determined by molecular methods in cattle from Bolivia, Brazil, Colombia and Peru, reason for which the presence of this parasite is not excluded in Venezuelan livestock. Therefore, the aim of this study was to perform parasitological and molecular diagnosis of cattle trypanosomosis in small livestock units from two regions in this country. The parasitological diagnosis was carried out by MHCT and the molecular by PCR using genus-specific ITS1 primers that differentiate T. vivax and T. evansi infections. 47 cattle were evaluated in the "Laguneta de la Montaña" sector, Miranda State, where 3 animals were diagnosed as positive (6.4 %) by MHCT and 14 (30 %) by PCR as Trypanosoma spp., out of which 9 animals resulted positive for T. vivax, 3 for T. evansi and 2 with double infections. Whilst in the "San Casimiro" sector, State of Aragua, out of the 38 cattle evaluated 7 animals were diagnosed as positive (18.4 %) by MHCT and 19 (50 %) by PCR, determining only the presence of T. evansi in this locality. The molecular diagnosis by PCR using ITS1 primers allowed T. evansi detection in cattle field populations, which suggests the possible role of these animals as reservoirs in the epidemiology of the disease caused by T. evansi in Venezuela.

9.
Ecotoxicol Environ Saf ; 119: 15-24, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25966333

ABSTRACT

Acute lethal and sublethal toxicity of the imidazolinone imazethapyr (IMZT)-based commercial formulation herbicide Pivot H® (10.59% IMZT) was evaluated on Hypsiboas pulchellus tadpoles. Whereas mortality was used as the end point for lethality, frequency of micronuclei (MNs) and other nuclear abnormalities as well as DNA single-strand breaks evaluated by the single cell gel electrophoresis assay were employed to test genotoxicity. Behavioral, growth, developmental, and morphological abnormalities were also employed as sublethal end points. Mortality studies revealed equivalent LC50 (96h) values of 1.49mg/L (confidence limit, 1.09-1.63) and 1.55mg/L (confidence limit, 1.51-1.60) IMZT for Gosner stage (GS) 25 and GS36, respectively. Behavioral changes, i.e., irregular swimming and immobility, as well as a decreased frequency of keratodonts were observed. The herbicide increased the frequency of MNs in circulating erythrocytes of tadpoles exposed for 48h to the highest concentration assayed (1.17mg/L). However, regardless of the concentration of the herbicide assayed, an enhanced frequency of MNs was observed in tadpoles exposed for 96h. The herbicide was able to induce other nuclear abnormalities, i.e., blebbed and notched nuclei, only when tadpoles were exposed for 96h. In addition, we observed that exposure to IMZT within the 0.39-1.17mg/L range increased the genetic damage index in treatments lasting for both 48 and 96h. This study represents the first evidence of acute lethal and sublethal effects exerted by IMZT on amphibians. Finally, our findings highlight the properties of this herbicide that jeopardize nontarget living species exposed to IMZT.


Subject(s)
DNA Damage/drug effects , Herbicides/toxicity , Nicotinic Acids/toxicity , Ranidae/physiology , Animals , Anura/growth & development , Comet Assay , Environmental Pollution/adverse effects , Erythrocytes/drug effects , Larva/drug effects , Micronuclei, Chromosome-Defective/drug effects , Mutagenicity Tests
10.
Ecotoxicol Environ Saf ; 104: 120-6, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24675439

ABSTRACT

The neonicotinoid insecticide imidacloprid (IMI) affects the insect central nervous system and is successfully applied to control pests for a variety of agricultural crops. In the current study, acute toxicity and genotoxicity of the IMI-containing commercial formulation insecticide Glacoxan Imida (35 percent IMI) was evaluated on Hypsiboas pulchellus (Anura: Hylidae) tadpoles exposed under laboratory conditions. A lethal effect was evaluated as the end point for lethality, whereas micronucleus (MN) frequency and DNA single-strand breaks evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Sublethal end points were assayed within the 12.5-37.5mg/L IMI concentration range. Experiments were performed on tadpoles at stage 36 (range, 35-37) according to the classification proposed by Gosner. Lethality studies revealed an LC50 96h value of 52.622mg/L IMI. Increased frequency of MNs was only observed when 25.0mg/L was assayed for 96h, whereas no other nuclear abnormalities were induced. Increase of the genetic damage index was observed at 48h of treatment within the 12.5-37.5mg/L concentration range, whereas an increased frequency of DNA damage was observed only in tadpoles treated with 37.5mg/L IMI for 96h. This study represents the first evidence of the acute lethal and genotoxic effects exerted by IMI on tadpoles of an amphibian species native to Argentina under laboratory conditions.


Subject(s)
Anura/physiology , DNA Damage/drug effects , Imidazoles/toxicity , Insecticides/toxicity , Larva/drug effects , Nitro Compounds/toxicity , Animals , Argentina , Comet Assay , Lethal Dose 50 , Micronuclei, Chromosome-Defective , Mutagenicity Tests , Neonicotinoids
11.
Open Vet J ; 2(1): 78-82, 2012.
Article in English | MEDLINE | ID: mdl-26623297

ABSTRACT

We evaluated the clinical, parasitological and immunological effects of a Venezuelan strain of Trypanosoma evansi (T. evansi) throughout in experimentally inoculated rabbits over the course of infection and compared them with the same aspect in healthy animals. Body temperature was recorded in degrees Celsius, animal weight in kilograms, serum proteins in g/dl using a refractometer, haematocrit percentage by capillary centrifugation and the anti-T. evansi IgG titer by indirect ELISA immunoassay, from both infected animals and controls for 95 days. Infected animals showed a higher body temperature, total serum protein and anti- T. evansi antibody titer, and a lower haematocrit and weight gain than controls. These differences were related to the presence of the parasites in the blood as detected micro-haematocrit centrifugation technique (MHCT) and direct microscopic examination (DME). This study confirms the usefulness of rabbits as a model for the study of trypanosomosis; the clinical features of the disease can be observed and the three characteristic stages, prepatent period, acute and chronic phase clearly defined over the course of the infection.

12.
Exp Parasitol ; 128(1): 91-6, 2011 May.
Article in English | MEDLINE | ID: mdl-21320490

ABSTRACT

The goal of this study was to compare two parasitological diagnostic techniques, such as by Micro-Haematocrit Centrifugation Technique (MHCT) and Direct Microscopic Examination (DME) with a serological method (iELISA), and a molecular procedure PCR, in rabbits experimentally infected with Trypanosoma evansi, in order to determine their sensitivity throughout the course of disease. The parasitological methods were not able of detecting the presence of the parasite during the phases of low parasitemia, the prepatency period and the chronic phase. In contrast, PCR detected T. evansi in the prepatency and chronic phase, when increase the amount of DNA from 100 to 300ng. 100% detection was observed with iELISA only in the chronic stage of the disease. In the acute phase, all samples were positively diagnosed using either MHCT or PCR, whereas only few samples were diagnosed by DME. Samples obtained from day 15 post infection were also detected by iELISA. The highest diagnostic register during the course of infection was achieved by the PCR technique (93.8%), followed by iELISA (71.1%), MHCT (59%) and DME (13.6%). Therefore, we recommend the use of PCR in epidemiological studies in order to implement sanitary control plans for the improvement of livestock productivity in the country.


Subject(s)
Trypanosoma/isolation & purification , Trypanosomiasis/diagnosis , Animals , Antibodies, Protozoan/blood , Blood/parasitology , Centrifugation , Chronic Disease , DNA, Protozoan/blood , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Female , Polymerase Chain Reaction , Rabbits , Rats , Sensitivity and Specificity , Trypanosoma/genetics , Trypanosoma/immunology
13.
Fungal Biol ; 114(1): 74-81, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20965064

ABSTRACT

Fusarium species are worldwide causal agents of ear rot in cereals. Their toxigenic potential is a health risk for both humans and animals. In Argentina, most identification of these fungi has been based on morphological and cross-fertility criteria which are time consuming and require considerable expertise in Fusarium taxonomy and physiology. DNA based approaches have been reported as rapid, sensitive and specific alternatives to identify the main fumonisin and trichothecene-producing Fusarium species. In this work, we used PCR assays and the partial sequence of TEF1-alpha gene (Translation Elongation Factor-1 alpha) to identify the fumonisin and trichothecene-producing species in Fusarium isolates from diverse regions of Argentina. The relative efficiency and reliability of those methods to improve mycotoxin risk prediction in this country were also assessed. Species-specific PCR assays were targeted toward multicopy IGS (Intergenic Spacer of rDNA units) and on the toxin biosynthetic genes FUM1 (fumonisins) and TRI13 and TRI7 genes (trichothecenes). PCR assays based on FUM1 gene and IGS sequences allowed detection and discrimination of the fumonisin producers Fusarium proliferatum and Fusarium verticillioides. Molecular identification of nonfumonisin producers from Gibberella fujikuroi species complex was possible after determination of TEF1-alplha gene sequences, which indicated the presence of Fusarium subglutinans, Fusarium andiyazi and Fusarium thapsinum. TEF-1 alpha gene sequences also allowed discrimination of the different species of the Fusarium graminearum complex (F. graminearum sensu lato) as F. graminearum sensu stricto, Fusarium meridionale and Fusarium boothii. The last two species belonged to NIV chemotype and were detected for the first time in the subtropical region of Argentina while F. graminearum sensu stricto was DON producer only, which was also confirmed by specific PCR assays based on TRI137/TRI7 genes. Our results indicated that the PCR assays evaluated in this work are reliable diagnostic tools to detect the main toxigenic Fusarium species associated to cereal grains in Argentina. An extensive epidemiological survey based on the approach presented in this work is currently in progress to know the mycotoxigenic hazard of Fusarium species in cereal grains from the subtropical region of Argentina.


Subject(s)
Edible Grain/microbiology , Fungal Proteins/genetics , Fusarium/classification , Fusarium/pathogenicity , Peptide Elongation Factor 1/genetics , Polymerase Chain Reaction/methods , Argentina , DNA, Fungal/analysis , DNA, Fungal/isolation & purification , Food Contamination , Fumonisins/metabolism , Fungal Proteins/metabolism , Fusarium/genetics , Fusarium/metabolism , Mycological Typing Techniques , Mycotoxins/genetics , Mycotoxins/metabolism , Peptide Elongation Factor 1/metabolism , Species Specificity , Time Factors , Trichothecenes/genetics , Trichothecenes/metabolism
14.
Pediatr Pulmonol ; 45(10): 1009-13, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20648670

ABSTRACT

BACKGROUND: Community-acquired pneumonia (CAP) is a leading cause of childhood death. There are few published reports of radiographic findings among children with severe CAP. OBJECTIVE: To describe chest X-ray (CXR) findings and assess association between these radiographic findings and pneumococcal isolation in children with severe CAP. METHODS: A prospective, multicenter, observational study was conducted in 12 centers in Argentina, Brazil, and the Dominican Republic. Children aged 3-59 months, hospitalized with severe pneumonia, were included. On admission, blood and pleural effusion cultures were performed. Streptococcus pneumoniae was identified according to standard procedures in the respective national reference laboratory. Chest X-rays were taken on admission and read before the culture results were reported. RESULTS: Out of 2,536 enrolled patients, 283 (11.2%) had S. pneumoniae isolated, in 181 cases (7.1%) from blood. The follow radiographic patterns were observed: alveolar infiltrate (75.2%), pleural effusion (15.6%), and interstitial infiltrate (9.2%). Overall, pleural effusion was associated with pneumococcal isolation and pneumococcal bacteremia (P < 0.001). Infiltrates were unilateral (78.7%) or bilateral (21.3%), right-sided (76%) or left-sided (24%), in the lower lobe (53.6%) or the upper lobe (46.4%). Multivariate analysis including patients with affection of only one lobe showed that upper lobe affection and pleural effusion were associated with pneumococcal isolation (OR 1.8, 95% CI, 1.3-2.7; OR 11.0, 95% CI, 4.6-26.8, respectively) and with pneumococcal bacteremia (OR 1.7, 95% CI, 1.2-2.6; OR 3.1, 95% CI, 1.2-8.0, respectively). CONCLUSIONS: Three-quarters of the patients studied had alveolar infiltrates. Upper lobe compromising and pleural effusion were associated with pneumococcal invasive disease.


Subject(s)
Community-Acquired Infections/diagnostic imaging , Community-Acquired Infections/microbiology , Pneumonia/diagnostic imaging , Pneumonia/microbiology , Child, Preschool , Female , Humans , Infant , Male , Radiography , Severity of Illness Index , Streptococcus pneumoniae/isolation & purification
15.
J Phys Condens Matter ; 22(21): 215701, 2010 Jun 02.
Article in English | MEDLINE | ID: mdl-21393724

ABSTRACT

Motivated by the superconducting properties of the metallic oxide Cd(2)Re(2)O(7), whose crystal structure is of the pyrochlore type, we propose an electronic model on a checkerboard lattice, which can be viewed as a two-dimensional analog of the pyrochlore lattice. Including only charge degrees of freedom, we treat the model via a Bardeen-Cooper-Schrieffer (BCS) approximation, decoupling the interaction terms in real space. Going over to reciprocal space yields a BCS model with two coupled bands. Characteristic properties such as order parameters and specific heat as functions of temperature are obtained. We also discuss the symmetry properties of the superconducting gap in wavevector space and the behavior of the critical temperature as a function of the electronic doping for various values of the interaction strength.

16.
Nat Genet ; 29(2): 141-2, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11559849

ABSTRACT

Non-syndromic cleft lip with or without cleft palate (CL/P, MIM 119530) is among the most common of major birth defects. Homozygosity for a nonsense mutation of PVRL1, W185X, results in an autosomal recessive CL/P syndrome on Margarita Island, CLPED1 (ref. 1). Here we demonstrate highly significant association between heterozygosity for this mutation and sporadic, non-syndromic CL/P in northern Venezuela.


Subject(s)
Cell Adhesion Molecules/genetics , Cleft Lip/genetics , Cleft Palate/genetics , Codon, Nonsense , Heterozygote , Homozygote , Humans , Nectins , Venezuela
17.
J Clin Microbiol ; 36(8): 2191-4, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9665989

ABSTRACT

Eighty-four cerebrospinal fluid (CSF) samples from different children who presented with signs and symptoms of meningitis were evaluated for the presence of Mycobacterium tuberculosis complex organisms by the Gen-Probe Amplified Mycobacterium tuberculosis Direct Test (MTD; Gen-Probe, San Diego, Calif.). All CSF samples had negative acid-fast smears by the Ziehl-Neelsen staining method. M. tuberculosis was recovered from five samples. M. tuberculosis did not grow from 19 additional samples, but the samples were from patients who fulfilled specific clinical and laboratory criteria for probable tuberculous meningitis (TBM). The remaining samples (n = 60) were from patients with other infections or noninfectious causes of meningitis. The results of the MTD were interpreted as positive or negative on the basis of recommended cutoff values for respiratory specimens. These results were interpreted as true or false positives or true or false negatives on the basis of the results of M. tuberculosis culture or whether the patient fulfilled criteria for probable TBM. The Gen-Probe MTD was 33% sensitive and 100% specific for detecting M. tuberculosis complex organisms in these 84 CSF samples. If the cutoff values for positive results were decreased for the MTD (> or = 11,000 versus > or = 30,000 relative light units), the sensitivity increased to 83% and the specificity remained 100%. These results for the MTD are encouraging considering that TBM is a highly fatal disease and difficult to diagnose by conventional laboratory techniques.


Subject(s)
Cerebrospinal Fluid/microbiology , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Meningeal/diagnosis , Adolescent , Child , Child, Preschool , Culture Media , Evaluation Studies as Topic , Female , Gene Amplification , Humans , Male , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/growth & development , Nucleic Acid Probes , Predictive Value of Tests , Reagent Kits, Diagnostic , Sensitivity and Specificity , Tuberculosis, Meningeal/cerebrospinal fluid , Tuberculosis, Meningeal/microbiology
18.
Prev Vet Med ; 30(2): 151-4, 1997 May.
Article in English | MEDLINE | ID: mdl-9234418

ABSTRACT

The prevalence of Babesia bovis antibodies was estimated by using an ELISA (98% sensitivity and 95% specificity). Sera were obtained from 165 calves (mean age and standard deviation: 9.7 +/- 2.7 months) from an area in Argentina known to be unfavourable for the development of the vector tick, Boophilus microplus. The area comprised about 300,000 ha used for cattle breeding. The cattle population of 55,000 included 12,000 cattle under 1 year of age. Cattle were maintained mainly on natural grasses in communal lands. The true prevalence of antibodies to Babesia bovis was 12.2% with a confidence interval of 7.6% to 18.2%, and an inoculation rate (h; daily probability of infection) of 0.0004. This confidence interval has its lower boundary in the area of endemic stability due to low h of Babesia bovis by the vector tick and the upper limit in the area of endemic instability. This type of analysis could help to decide the implementation of preventive measures (e.g. vaccination) rationally, even in remote areas (such as the one of the present study) with an extensive cattle industry.


Subject(s)
Antibodies, Protozoan/blood , Babesia bovis/immunology , Babesiosis/epidemiology , Babesiosis/prevention & control , Cattle Diseases/epidemiology , Cattle Diseases/prevention & control , Animals , Antibodies, Protozoan/immunology , Argentina/epidemiology , Breeding , Cattle , Cross-Sectional Studies , Disease Outbreaks/veterinary , Disease Vectors , Prevalence , Tick-Borne Diseases/epidemiology , Tick-Borne Diseases/immunology , Tick-Borne Diseases/veterinary
19.
Arq Bras Cardiol ; 62(5): 329-36, 1994 May.
Article in Portuguese | MEDLINE | ID: mdl-7998865

ABSTRACT

PURPOSE: To study the incidence of ischemic mitral regurgitation (MR) and the mortality. METHODS: One-hundred-five cases of acute myocardial infarction (AMI) with MR were reviewed. Patients were divided in two groups: group A-59 (56.2%) necropsied patients without previous surgical procedures to correlate clinical pictures with the aim to determine the cause of death; group B-46 (43.8%) patients were submitted to surgical treatment. This group was subdivided in mild, moderate and severe forms of MR, and studied comparatively the type of surgical treatment and its evolution. RESULTS: Group A-23 (39%) patients with mild forms and predominant ischemic heart disease, responsible for death; 18 (30.5%) patients without previous diagnosis, masked by myocardial failure and 18 (30.5%) with severe MR and coronary heart disease; group B-14 (30.4%) patients died at the immediate post-operatory period. Higher mortality associated to ejection fraction (EF) below 35% (47.6%; p = 0.022), severe MR (41.7%; p = 0.044) and cardiogenic shock (52.9%; p = 0.14). In 41 (89.1%), the mitral valve repair was combined to coronary artery bypass grafting operation (CABG), in 4 (8.7%) this last procedure was made without mitral repair and in the remaining patients the surgery was limited to the valve. Mitral valvuloplasty was performed in 23 (50%) patients with 3 (13%) deaths, and in 19 (42.3%) the mitral valve was replaced with 9 (47.4%) deaths. CONCLUSION: The prognosis is related to the grade of EF and to the severity of MR. In mild to moderate forms, the surgical indication is due to the associated coronary heart disease and the valvuloplasty is preferred, in this instance. In severe forms, surgical intervention must be performed as soon as possible, before cardiogenic shock appears.


Subject(s)
Mitral Valve Insufficiency/epidemiology , Myocardial Infarction/complications , Adult , Aged , Aged, 80 and over , Female , Humans , Incidence , Male , Middle Aged , Mitral Valve Insufficiency/mortality , Mitral Valve Insufficiency/pathology , Mitral Valve Insufficiency/surgery , Myocardial Infarction/mortality , Prognosis , Retrospective Studies
20.
Rev Med Chil ; 120(5): 545-51, 1992 May.
Article in Spanish | MEDLINE | ID: mdl-1343068

ABSTRACT

Epomediol is a terpenoid that prevents and reverses cholestasis induced by ethinylestradiol in the rat, apparently by improving liver cell membrane fluidity. Assuming that the pathogenesis of intrahepatic cholestasis of pregnancy (ICP) is related with increased estrogen levels, we studied the effects of epomediol in this disease. Patients hospitalized due to ICP received epomediol 900 mg/day (n = 7), or 1,200 mg/day (n = 4) orally, during 15 days. Biochemical parameters of liver dysfunction (serum bilirubin, bile salts, aminotransferase, alkaline phosphatases) were not modified during nor after epomediol administration. The severity of pruritus was significantly reduced in comparison to pretreatment status, with both doses of epomediol. A greater amelioration of pruritus was observed in patients treated with epomediol 1,200 mg/day than in patients who received 900 mg/day (to 20.7 +/- 6.2, as percent of pre-treatment severity score, versus 48.8 +/- 7.5 respectively; p < 0.05). After epomediol administration was stopped, pruritus relapsed in 6 patients; 3 of them had received the higher drug dose. After delivery, pruritus vanished and liver function tests returned to normal, in all patients. No adverse effects attributable to the drug were observed in the mothers or in their babies. The beneficial effect of epomediol on pruritus in patients with ICP appeared greater in this study than that observed recently in similar patients who received a placebo.


Subject(s)
Cholagogues and Choleretics/therapeutic use , Cholestasis, Intrahepatic/drug therapy , Pregnancy Complications/drug therapy , Terpenes/therapeutic use , Bile Acids and Salts/blood , Bridged Bicyclo Compounds, Heterocyclic , Cholagogues and Choleretics/administration & dosage , Cholagogues and Choleretics/pharmacokinetics , Cholestasis, Intrahepatic/blood , Cholestasis, Intrahepatic/complications , Female , Humans , Hyperbilirubinemia/drug therapy , Hyperbilirubinemia/etiology , Infant, Newborn , Liver Function Tests , Pilot Projects , Pregnancy , Pruritus/drug therapy , Pruritus/etiology , Recurrence , Severity of Illness Index , Terpenes/administration & dosage , Terpenes/pharmacokinetics
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