Search

Copyright of Revista Mexicana de Endocrinología, Metabolismo y Nutrición is the property of Publicidad Permanyer SLU and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peromyscus is the most speciose genus in America, which occupies almost every terrestrial habitat type. However, its taxonomy and evolutionary relationships remain unsolved in several species, one species group with these issues is the P. boylii complex. This complex consists of 11 species (P. beatae, P. boylii, P. carletoni, P. ensinki, P. greenbaumi, P. kilpatricki, P. levipes, P. madrensis, P. schmidlyi, P. simulus, and P. stephani) largely distributed in Mexico and has been taxonomically studied during the last 40 years, resulting in the description of new species, several of them from the mountains of central Mexico. In this study, we aimed to integrate molecular, morphometric, and spatial data analysis approaches to inquire into the phylogenetic relationships. To clarify the taxonomic status of the P. boylii complex, particularly for the species distributed in the central Mexican highlands where the taxonomic uncertainty is high. We performed phylogenetic and divergence time analyses based on four molecular markers for all species within the complex, we explored cranium shape and size variation in 146 individuals of continental species (P. madrensis and P. stephani excluded) using geometric morphometrics. Also, we evaluated environmental differentiation and ecological niche modeling analyses of three species endemic to the central Mexican highlands to retrieve evidence on their evolutionary history. Our results recovered one well-supported clade including all mountainous species, in which P. schmidlyi was sister to the clade composed of P. greenbaumi and P. ensinki, which diverged during the late Pleistocene. The novel morphological data allowed a better differentiation of all continental species. The discovery of new specimens for P. greenbaumi and P. ensinki improved their taxonomic knowledge, as well as delimiting their habitat and distribution, showing substantial environmental divergence with low overlapped geographical distributions; P. schmidlyi restricted to the Sierra Madre Occidental, P. ensinki to the central-west Trans-Mexican Volcanic Belt, and P. greenbaumi to the center of the Sierra Madre del Sur. We discuss the biogeographic history of these three lineages and the role of the late Pleistocene climatic oscillations on their diversification. [ABSTRACT FROM AUTHOR]

Habitat specialists are particularly vulnerable to extinction when habitat conditions are altered. Information on the habitat use of such species is thus important because it provides insight into factors that influence distribution and abundance, which is crucial for conservation. Here, we aimed to identify factors that influence the patterns of presence and abundance of the Endangered volcano rabbit Romerolagus diazi, a rare leporid with a patchy distribution. Through exhaustive sampling of its range in the Sierra Chichinautzin and Sierra Nevada volcanic fields, Mexico, and using generalized linear models, we found that the probability of patch occupancy was higher where bunchgrass cover exceeded 75%, rock cover exceeded 5%, no cattle grazing was observed and human settlements were at least 7 km away. Patches with greater relative abundance were those with similar characteristics, but located at elevations > 3,600 m, and with rock cover < 15%. Cattle grazing was identified as a major threat to local populations of the volcano rabbit, particularly in the Sierra Chichinautzin. Because of the significance of bunchgrasses for this species, the protection of the mountain grasslands is required in both volcanic fields. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zoological Systematics & Evolutionary Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Pesquisa em Turismo is the property of Associacao Nacional de Pesquisa e Pos-Graduacao em Turismo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Endocrinología, Metabolismo y Nutrición is the property of Publicidad Permanyer SLU and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Context: Acromegaly registries constitute a valuable source of therapeutic outcome information in real-life.Objective: The objective of this work is to analyze surgical and pharmacological outcomes in the Mexican Acromegaly Registry (MAR).Design and Methods: Data were extracted from the MAR informatic platform. Surgical remission was defined by a postoperative postglucose (GH) of less than 1 ng/mL and an insulin-like growth factor 1 (IGF-1) of less than 1.2 × upper limit of normal (ULN). Pharmacological remission was defined by a basal GH of less than 1 ng/mL and an IGF-1 of less than 1.2 × ULN.Results: A total of 650 surgical outcomes were analyzed (94.6% transsphenoidal). Surgical remission was achieved in 40.15%, whereas 44.15% remained biochemically active. Persistently active disease after surgery was significantly associated with harboring an invasive macroadenoma, a basal GH of greater than 10 ng/mL, and/or an IGF-1 of greater than 2 × ULN at diagnosis on bivariate and multivariate analysis. The outcome of monotherapy with first-generation somatostatin analogs (SSAs) was evaluated in 267 patients (adjunctive in 65%), of whom 28.4% achieved remission. Persistently active disease was significantly associated with harboring an invasive macroadenoma as well as with pretreatment basal GH and IGF-1 levels of greater than 10 ng/mL and greater than 2 × ULN, respectively, on bivariate and multivariate analysis. Combined therapy with SSA and cabergoline was analyzed in 100 patients, of whom 19% achieved remission and 44% remained active; in this subset of patients, only a pretreatment IGF-1 of greater than 2 × ULN was significantly associated with persistent disease activity.Conclusion: Surgical and pharmacological outcomes in acromegaly are highly dependent on tumor size/invasiveness as well as on the degree of hypersomatotropinemia. [ABSTRACT FROM AUTHOR]

Copyright of Turismo: Visão e Ação is the property of Turismo-Visao E Acao and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chronic obstructive pulmonary disease (COPD) is a complex and multifactorial disease with a strong genetic component. Our objective is to identify the genetic variants associated with COPD risk and its severity in Mexican Mestizo population. We evaluated 1285 single-nucleotide polymorphisms (SNPs) of candidate genes in 299 smokers with COPD (COPD-S) and 531 smokers without COPD (SWOC) using an Illumina GoldenGate genotyping microarray. In addition, 251 ancestry informative markers were included. Allele A of rs2545771 inCYP2F2Pis associated with a lower risk of COPD (p= 4.02E-10, odds ratio [OR] = 0.104, confidence interval [CI] 95% 0.05–0.18). When the COPD group was stratified by severity according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD; levels III + IVvs. I + II), 3 SNPs (rs4329505 and rs4845626 ininterleukin 6 receptor [IL6R] and rs1422794 ina disintegrin and metalloproteinase domain 19 [ADAM19]) were associated with a lower risk of suffering the most severe stages of the disease. rs2819096 in thesurfactant protein D(SFTPD) gene was associated with a higher risk of COPD GOLD III + IV (p= 7.79E-03, OR = 1.80, CI 95% 1.16–2.79). Finally, the haplotype inIL6Rwas associated with a lower risk of suffering from more severe COPD, whereas the haplotype inADAM19was associated with a higher risk (p= 7.40E-03, OR = 2.83, CI 95% 1.20–6.86) of suffering from the severe stages of the disease. Our data suggest that there are alleles and haplotypes in theIL6R, ADAM19,andSFTPDgenes associated with different severity stages of COPD; inCYP2F2P, rs25455771 is associated with a lower risk of COPD. [ABSTRACT FROM PUBLISHER]

Objective. The aim of this study was to determine the prevalence of asymptomatic nasopharyngeal carriage of Streptococcus pneumoniae, which is a major factor in the transmission of this bacterium. Material and Methods. Nasopharyngeal cultures were performed on children attending 32 day-care centers in 12 states in Mexico. Results. Streptococcus pneumoniae was isolated from the nasopharynx of 829 out of 2 777(29.9%) subjects aged two months to six years. All children lived in urban areas and 80% spent more than six hours daily in a day-care center. Streptococcus pneumoniae serotypes most frequently identified were: 19F (23%), 6B (15.6%), 23F (11.2%) and 6A (14.9%). Thirty-six percent of the isolates were susceptible to penicillin. Conclusions. Serotype distribution suggests the possible benefits that could be obtained from the heptavalent pneumococcal conjugate vaccine. [ABSTRACT FROM AUTHOR]

Evaluates attitudes and concerns of government and non-government institutions in La Paz Bay, Baja California, Mexico, with respect to ecotourism. Assessment of the extent of fulfillment of ecotourism principles by tour operators in protected areas; Expectations of government and non-government institutions, as well as ecotourism operators; Conclusion that conservation strategy depends on the strategies designed by protected area managers.

A. Typical specimen of a plant of the genus Ceratozamia. B. Ontogenetic transformation by estimating the difference in the value of the leaflets shape index between seedlings and adults. C. Phylogeny of Ceratozamia species. In each terminal typical leaflets of each species are presented. • Comprehensive phenotypic assessment of populations-species of a cycad genus. • Molecular phylogeny supports two clades: ' miqueliana' and ' mexicana '. • Ceratozamia was originated at the S of Mexico and diversified in the last 3 Mya. • Empirical evidence of punctuated evolution in the lineages encompassed by Ceratozamia. • Ontogeny also traces the evolutionary history of the Ceratozamia species. Evidence suggests that past climatic fluctuations affected speciation of extant cycads. However, empirical genetic and morphological evidence explaining patterns and processes of species diversification are scarce. There are some explanations for the origin and evolution of the genus Ceratozamia , but with inconclusive results. To elucidate the evolution of Ceratozamia , we used genetic and phenotypic sources as empirical data, which were applied in a 'proximate-ultimate' framework (ecological and evolutionary scale, respectively). Our results suggested that the evolutionary mechanisms of speciation were shaped by deterministic (natural selection-adaptation) driven by climatic conditions associated to water stress, and probably enhanced by stochastic processes (gene drift and inbreeding). In general terms, punctuated evolution models were those that best explained the patterns of speciation throughout the phylogenetic history of the lineages encompassed in the genus Ceratozamia. Finally, we provide empirical evidence on the tempo and mode of the evolution of a 'living plant fossil'. [ABSTRACT FROM AUTHOR]

A widespread biogeographic pattern in nature is that population abundance is not uniform across the geographic range of species: most occurrence sites have relatively low numbers, whereas a few places contain orders of magnitude more individuals. The Bolson tortoise Gopherus flavomarginatus is endemic to a small region of the Chihuahuan Desert in Mexico, where habitat deterioration threatens this species with extinction. In this study we combined field burrows counts and the approach for modeling species abundance based on calculating the distance to the niche centroid to obtain range-wide abundance estimates. For the Bolson tortoise, we found a robust, negative relationship between observed burrows abundance and distance to the niche centroid, with a predictive capacity of 71%. Based on these results we identified four priority areas for the conservation of this microendemic and threatened tortoise. We conclude that this approach may be a useful approximation for identifying key areas for sampling and conservation efforts in elusive and rare species.

Niche conservatism theory suggests that recently diverged sister species share the same ecological niche. However, if the ecological niche evolves as part of the speciation process, the ecological pattern could be useful for recognizing cryptic species. In a broad sense systematists agree that the niche characters could be used for species differentiation. However, to date such characters have been ignored. We used the genetic algorithm for rule-set production for modelling the ecological niche as a means of inferring ecological divergence in allopatric populations of muroid rodents for which taxonomic identity is uncertain. Our results show that niche differentiation is significant in most of the identified phylogroups. The differentiation is likely associated with natural evolutionary units, which can be identified by applying species concepts based on phylogenetic and ecological patterns (e.g. phylogenetic, cohesive, evolutionary). Even so, the role of the niche partition within phylogenetic reconstruction may be a limited one.

Background: To study the sensitivity and specificity of the 50-g, 1-hour gestational glucose challenge test performed 1 to 2 hours after a non-standardized home breakfast in urban Mexican women by using three different gestational diabetes mellitus diagnostic criteria., Methods: Four hundred and forty-five consecutive women of 24-28 weeks gestation were studied. The glucose challenge test was performed in the fed state and a week later a fasting 100-g, 3-hours oral glucose tolerance test was carried out in all of them. Duplicate serum glucose concentrations were determined by a glucose-oxidase method. Sensitivity and specificity were calculated using three different diagnostic criteria for gestational diabetes mellitus., Results: The glucose challenge test performed as indicated, with a cutoff of 7.8 mmol/L, had 88-89% sensitivity and 85-87% specificity when using as diagnostic criteria those proposed by the National Diabetes Data Group and by Carpenter & Coustan; by using Sacks et al. criteria, the values were 82% and 88%, respectively. Considering only pregnant women > or = 25 years of age, the sensitivity increased to 92% with the National Diabetes Data Group criteria. Pregnant women < 25 years of age had significantly lower blood glucose values than those with age > or = 25 years during the glucose tolerance test., Conclusions: For the general group the sensitivity of the glucose challenge test performed 1 to 2 hours after breakfast was similar, based on the National Diabetes Data Group and the Carpenter & Coustan's diagnostic criteria for gestational diabetes mellitus. However, when pregnant women > or = 25 years of age were considered, the use of the former criteria yielded a slightly better sensitivity.

39 patients which underwent an IVF-ET procedure at the INPer were divided in two groups. To one of them, progesterone was administered since the day of oocyte retrieval (group I), whereas the other group received progesterone 48 hours before hCG administration (group II). There were no statistical differences between the groups in the parameters analysed before the oocyte retrieval. There were statistical differences between the groups in progesterone levels in the day of oocyte retrieval in favour of group II, and in fertilization rate and transfer rate for group I. There were no valuable differences between the groups in pregnancy rate.