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31.
Eric G. Hernández Julio Granados Oswaldo Partida-Rodríguez Olivia Valenzuela Edgar Rascón Ulises Maga?a Mónica Escamilla-Tilch Alberto López-Reyes Miriam Nieves-Ramírez Enrique González Patricia Morán Liliana Rojas Alicia Valadez Alexandra Luna Francisco J. Estrada Carmen Maldonado Cecilia Ximénez 《PloS one》2015,10(5)
Amebiasis is an endemic disease and a public health problem throughout Mexico, although the incidence rates of amebic liver abscess (ALA) vary among the geographic regions of the country. Notably, incidence rates are high in the northwestern states (especially Sonora with a rate of 12.57/100,000 inhabitants) compared with the central region (Mexico City with a rate of 0.69/100,000 inhabitants). These data may be related to host genetic factors that are partially responsible for resistance or susceptibility. Therefore, we studied the association of the HLA-DRB1 and HLA-DQB1 alleles with resistance or susceptibility to ALA in two Mexican populations, one each from Mexico City and Sonora. Ninety ALA patients were clinically diagnosed by serology and sonography. Genomic DNA was extracted from peripheral blood mononuclear cells. To establish the genetic identity of both populations, 15 short tandem repeats (STRs) were analyzed with multiplexed PCR, and the allelic frequencies of HLA were studied by PCR-SSO using LUMINEX technology. The allele frequencies obtained were compared to an ethnically matched healthy control group (146 individuals). We observed that both affected populations differed genetically from the control group. We also found interesting trends in the population from Mexico City. HLA-DQB1*02 allele frequencies were higher in ALA patients compared to the control group (0.127 vs 0.047; p= 0.01; pc= NS; OR= 2.9, 95% CI= 1.09-8.3). The less frequent alleles in ALA patients were HLA-DRB1*08 (0.118 vs 0.238 in controls; p= 0.01; pc= NS; OR= 0.42, 95% CI= 0.19-0.87) and HLA-DQB1*04 (0.109 vs 0.214; p= 0.02; pc= NS; OR= 0.40, 95% CI= 0.20-0.94). The haplotype HLA-DRB1*08/-DQB1*04 also demonstrated a protective trend against the development of this disease (0.081 vs. 0.178; p=0.02; pc=NS; OR= 0.40, 95% CI= 0.16-0.93). These trends suggest that the prevalent alleles in the population of Mexico City may be associated with protection against the development of ALA. 相似文献
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33.
Bruce T Martinez IB Maia Neto O Vicente AC Kruger RH Thompson FL 《Microbial ecology》2010,60(4):840-849
The aim of this study was to characterize the bacterial community diversity of the Brazilian Atlantic forest soil by means of both cultivation and 16S rRNA clone libraries. A collection of 86 representative isolates, obtained from six samples of Atlantic forest soils from the National Park of Serra dos Órgãos (PARNASO), belonged to the genera Arthrobacter, Bacillus, Burkholderia, Leifsonia, Paenibacillus, Pseudomonas, Ralstonia, Serratia, and Streptomyces according to the 16S rRNA sequences. Representative isolates from the different genera degraded cellulose and lignin. The culture-independent analysis based on 894 partial 16S rRNA gene sequences revealed that the most frequently retrieved groups belonged to the phyla Acidobacteria (29–54%), Proteobacteria (16–38%), and Verrucomicrobia (0.6–14%). The majority of the sequences (82.6%) were unidentified singletons and doubletons, indicating a high diversity of rare unique sequences. Chao1 estimator disclosed a high number of phyla (41–152) and species (263–446). This is the first survey on the Atlantic Forest soils using a combination of cultivation and culture-independent approaches. We conclude that the Brazilian Atlantic Forest soil represents a vast source of novel bacteria. 相似文献
34.
Varela Eduardo Sousa; Beasley Colin Robert; Schneider Horacio; Sampaio Iracilda; Marques-Silva Nelane Do Socorro; Tagliaro Claudia Helena 《Journal of Molluscan Studies》2007,73(3):229-234
As a result of phenotypic plasticity, the cupped oysters (Crassostrea)are difficult to identify by means of their morphology. However,molecular DNA markers are a useful means of discriminating amongthese species. Cupped oysters are one of the most widely culturedmarine invertebrates and correct species identification is importantin aquaculture. Moreover, the molecular phylogeny of the genusCrassostrea and the subfamily Crassostreinae is still not clear.In order to identify the Brazilian cupped oysters and to clarifythe phylogenetic relationships of these species, we sequenceda fragment of mitochondrial DNA (16S rRNA gene) from 120 specimenscollected at nine different sites distributed along the Braziliancoast. The results identified two native species of oyster:Crassostrea gasar, from the Amazon to the Parnaíba delta;and Crassostrea rhizophorae, from the northeast (Fortim) tothe south of Brazil. An exotic Crassostrea species, closelyrelated to Indo-Pacific Crassostrea, was found in one locationin the north of Brazil. Crassostrea showed monophyly and theAtlantic oysters are clearly separated from the Indo-Pacificcluster. (Received 30 May 2006; accepted 12 April 2007) 相似文献
35.
Marreiro DN do Perpetuo Socorro C Martins M de Sousa SS Ibiapina V Torres S Pires LV do Nascimento Nogueira N Lima JM do Monte SJ 《Biological trace element research》2007,120(1-3):42-50
The objective of this study was to assess urinary excretion of zinc and evaluation parameters of metabolic control in type
2 diabetic patients. Thirty-one type 2 diabetic patients, of both genders, with 5.8 ± 5.6 years average time of the disease,
age range 20–60 years, were selected. Evaluation of the nutritional status was performed using anthropometric measurements.
To evaluate food consumption, the 3-day alimentary log method was used, and its analysis was performed using a software. Determination
of urinary zinc was by atomic absorption spectrophotometry. From the obtained results, it was concluded that 51.6% of the
patients were overweight. The mean of found waist circumference was 100.4 and 92.2 cm for men and women, respectively. Blood
glucose and glycated hemoglobin values were higher than reference values, and plasma albumin concentration was adequate. The
median of found urinary zinc excretion was 474.9 μg/24 h, within normal standards (300–600 μg/day). Regarding diet composition,
calorie and protein concentration were above recommendation, while mean zinc concentration was adequate. This data allow the
conclusion that the evaluated patients presented adequate urinary zinc excretion in comparison with reference values. 相似文献
36.
Utrera R Ridaura V Rodríguez Y Rojas MJ Mago L Angeli S Henríquez O 《Genetic testing》2007,11(4):347-352
Severe to profound hearing impairment affects 1 of every 1000 newborn children each year. Inheritance accounts for 60% of these cases, of which 70% are nonsyndromic. The most common cause of autosomal recessive nonsyndromic hearing loss (ARNSHL) is mutation in GJB2, a gene on chromosome 13, which encodes a gap junction protein named Connexin 26. Mutations in GJB2 are responsible for 40% of genetic childhood deafness. The most common mutation, 35delG, predominates in many ethnic groups. Some families with linkage to the DFNB1 locus have none or only one mutated allele in GJB2, however, some subjects can exhibit a large deletion in another connexin gene, GJB6, resulting in a monogenic or digenic pattern of inheritance in this complex DFNB1 locus that contains both genes (GJB2 and GJB6). The aim of the study was to determine (1) the frequency for the 35delG (27.5%), del(GJB6-D13S1830) (2.5%) and del(GJB6-D13S1854) (0.0%) mutations in a cohort of 40 Venezuelan patients with ARNSHL and (2) the carrier frequency 35delG (4%), del(GJB6-D13S1830) (0%) and del(GJB6-D13S1854) (0%) in the Venezuelan population with no familial history of hearing impairment. One patient (2.5%) was detected as double heterozygote for the deletion del(GJB6-D13S1830) and 35delG mutation. This result has direct clinical implications because we include the molecular detection of the deletion del(GJB6-D13S1830) during the evaluation of the diagnosis of deafness in the Venezuelan population. 相似文献
37.
Oliveira Willams Silva Jéssica Luiza S. Cruz-Neto Oswaldo Oliveira Marcela Tomaz P. Fernandes de Albuquerque Isabelle Borges Laís Angélica Lopes Ariadna Valentina 《Journal of plant research》2022,135(2):235-245
Journal of Plant Research - In mixed-ploidy populations, newly formed polyploids initially occur at low frequencies when compared to diploids. However, polyploidy may lead to morphological and... 相似文献
38.
Male reproductive cycle in Aspidoscelis costata costata (Squamata: Teiidae) from Tonatico,Estado de México,México
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Gisela Granados‐González Justin L. Rheubert Maricela Villagrán‐SantaCruz María E. González‐Herrera Jessica V. Dávila‐Cedillo Kevin M. Gribbins Oswaldo Hernández‐Gallegos 《Acta zoologica》2015,96(1):108-116
The purpose of this study was to investigate the reproductive cycle of a high‐elevation population of Aspidoscelis costata costata (1500–1600 m) and compare its reproductive cycle with that of other populations, species, and closely related genera. Adult male A. costata costata lizards were collected, and the reproductive tracts were removed and subjected to histological analyses. Testicular activity commences in March with maximum testicular activity and highest sperm abundance (in the epididymides) occurring between May and July. The testis remains at peak activity until September when a late regression/early quiescent phase is observed. Leydig cells follow this same pattern except these hormone‐producing cells remain at maximum secretory level through September. Sperm are present in the epididymides in April–September. This pattern is consistent with the spring recrudescence found in a multitude of male lizard taxa. However, this differs from the continuous cycle observed in some tropical Teiid species and other lizard taxa at high elevation. This study indicates that our knowledge about lizard spermatogenic cycles remains incomplete, and additional studies are required to fully understand the interactions between phenotype, evolution, phylogenetics and environment. 相似文献
39.
Franziska Volland-Voigt Achim Br?uning Oswaldo Ganzhi Thorsten Peters Hector Maza 《Trees - Structure and Function》2011,25(1):39-48
Stem diameter increments of the broadleaved deciduous tree species Tabebuia chrysantha were measured with high-resolution dendrometers in a tropical lower montane forest and in a dry forest in southern Ecuador,
the latter showing a distinct dry season. Those analyses were complemented by wood anatomical studies on regularly collected
microcores to determine the season of active cambial growth and the time of formation of annual growth boundaries. The length
of the cambial active period varied between 3 and 7 months at the tropical lower montane forest and 2 and 4 months in the
dry forest, respectively. During dry days, amplitudes of daily stem diameter variations correlated with vapour pressure deficit.
During October and November, inter-annual climate variations may lead to dry and sunny conditions in the tropical lower montane
forest, causing water deficit and stem diameter shrinkage in T. chrysantha. The results of the climate–growth analysis show a positive relationship between tree growth and rainfall as well as vapour
pressure deficit in certain periods of the year, indicating that rainfall plays a major role for tree growth. 相似文献
40.
de Lira FA Farias Mde S de Figueiredo AF Gil Fdos S dos Santos MA Malheiros BV Ferreira JE Pinheiro JC Treu-Filho O Kondo RT 《Journal of molecular modeling》2011,17(7):1621-1624
In a previous article, we used Hartree-Fock (HF) theory to study the piezoelectricity in BaTiO3. In this paper, we applied the Douglas-Kroll-Hess second order scalar relativistic method to investigate the possible piezoelectric
properties in the perovskite YFeO3 structure, which has not yet been studied experimentally. The 30s20p13d and 31s21p17d Gaussian basis sets for the Fe (5D) and Y (2D) atoms, respectively, were built with the Generator Coordinate HF method. After contraction to [13s7p5d] and [13s8p7d],
in combination with the 20s14p/6s4p basis set for the O (3P) atom from literature, they had their quality evaluated using calculations of the total and the orbital energies for the
2FeO+1 and 1YO+1 fragments. The dipole moment, the total energy, and the total atomic charges in YFeO3 in Cs space group were calculated. The results and the analysis lead us to believe that the perovskite YFeO3 does not present piezoelectric properties. 相似文献