RESUMO
Women with a history of preeclampsia (PE) have a greater risk of pulmonary arterial hypertension (PAH). In turn, pregnancy at high altitude is a risk factor for PE. However, whether women who develop PE during highland pregnancy are at risk of PAH before and after birth has not been investigated. We tested the hypothesis that during highland pregnancy, women who develop PE are at greater risk of PAH compared to women undergoing healthy highland pregnancies. The study was on 140 women in La Paz, Bolivia (3640m). Women undergoing healthy highland pregnancy were controls (C, n = 70; 29 ± 3.3 years old, mean±SD). Women diagnosed with PE were the experimental group (PE, n = 70, 31 ± 2 years old). Conventional (B- and M-mode, PW Doppler) and modern (pulsed wave tissue Doppler imaging) ultrasound were applied for cardiovascular íííassessment. Spirometry determined maternal lung function. Assessments occurred at 35 ± 4 weeks of pregnancy and 6 ± 0.3 weeks after birth. Relative to highland controls, highland PE women had enlarged right ventricular (RV) and right atrial chamber sizes, greater pulmonary artery dimensions and increased estimated RV contractility, pulmonary artery pressure and pulmonary vascular resistance. Highland PE women had lower values for peripheral oxygen saturation, forced expiratory flow and the bronchial permeability index. Differences remained 6 weeks after birth. Therefore, women who develop PE at high altitude are at greater risk of PAH before and long after birth. Hence, women with a history of PE at high altitude have an increased cardiovascular risk that transcends the systemic circulation to include the pulmonary vascular bed.
Assuntos
Hipertensão Pulmonar , Pré-Eclâmpsia , Gravidez , Humanos , Feminino , Adulto , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/etiologia , Pré-Eclâmpsia/epidemiologia , Pré-Eclâmpsia/etiologia , Altitude , Bolívia/epidemiologia , PulmãoRESUMO
BACKGROUND: Acinetobacter baumannii is a cause of healthcare-associated infections and has considerable potential to survive on inanimate hospital surfaces under hostile conditions (e.g. disinfection or desiccation). AIM: To learn more about its survival strategy and capacity to persist in liquid media and on surfaces mimicking hospital environments. METHODS: The effect of temperature, nutrient deprivation, permanence on inanimate surfaces, and exposure to disinfectants on the survival of four A. baumannii strains (ATCC 19606T and three clinical isolates) was studied by monitoring the number of total and viable cells using fluorescent microscopy and of culturable cells by standard cultures. FINDINGS: Bacterial survival was differentially affected by temperature (cells maintained at 20°C remained culturable at least within 30 days) and physical environment (desiccation favoured cell resistance to stress at 37°C). Moreover, persistence was associated with two adaptation patterns: one linked to entry into the viable but non-culturable state, whereas the other apparently followed a bust-and-boom model. During a study on the effect of disinfectant (commercial bleach and quaternary ammonium compounds), it was found that treatment with these antibacterial compounds did not eliminate A. baumannii populations and provoked the reduction of culturable populations, although a fraction of cells remained culturable. CONCLUSION: The ability to persist for long periods on different surfaces, mimicking those usually found in hospitals, along with A. baumannii's capacity to survive after a disinfection process may account for the recurrent outbreaks in intensive care units.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/fisiologia , Desinfetantes/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Acinetobacter baumannii/efeitos da radiação , Meios de Cultura/química , Microbiologia Ambiental , Viabilidade Microbiana/efeitos da radiação , TemperaturaRESUMO
In their natural ecosystems, bacteria are continuously exposed to changing environmental factors including physicochemical parameters (e.g. temperature, pH, etc.), availability of nutrients as well as interaction(s) with other organisms. To increase their tolerance and survival under adverse conditions, bacteria trigger a number of adaptation mechanisms. One of the well-known adaptation responses of the non-spore-forming bacteria is the acquisition of the viable but non-culturable (VBNC) state. This phenotype is induced by different stress factors (e.g. low temperature) and is characterized by the temporal loss of culturability, which can potentially be restored. Moreover, this response can be combined with the bust and boom strategy, which implies the death of the main population of the stressed cells (or their entry into the VBNC state) upon stress, thus enabling the remaining cells (i.e. residual culturable population) to subsist at the expense of the dead or/and VBNC cells. In this review, we discuss the characteristics of the VBNC state, its biological significance and contribution to bacterial survival.
Assuntos
Escherichia coli/fisiologia , Vibrio/fisiologia , Adaptação Biológica/fisiologia , Fenômenos Químicos , Temperatura Baixa , Microbiologia Ambiental , Interações Microbianas , Viabilidade Microbiana , Fenótipo , Esporos Bacterianos/fisiologia , Estresse Fisiológico/fisiologiaRESUMO
Acinetobacter baumannii possesses a tremendous potential to thrive under hostile conditions. To learn more about its survival strategy and capacity to persist in the environment, we studied the effect of temperature, nutrient deprivation and dryness on the long-term survival of two A. baumannii strains (ATCC 19606(T) and a clinical isolate). Our results revealed that both strains show a great persistence under stress that appears to involve a bust-and-boom strategy. Bacterial survival was differentially affected by temperature and physical environment: Desiccation favored cell resistance to stress at 20 and 37 °C, while survival in aqueous environments was temperature dependent and led to changes in several cellular characteristics. In addition, we tested the ability of the A. baumannii ATCC 19606(T) strain to form biofilms by monitoring the expression of adhesion-/biofilm-related genes (ompA, bfmR and csuAB). The observed downregulation of these genes suggests that the potential difficulties to adhere to solid surfaces and form biofilms likely limit the capacity of starved cells to spread and colonize abiotic surfaces.
Assuntos
Acinetobacter baumannii/fisiologia , Viabilidade Microbiana , Acinetobacter baumannii/efeitos dos fármacos , Biofilmes , Meios de Cultura/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Temperatura , Água/metabolismoRESUMO
Allele frequency distribution and forensic parameters of the AmpFâSTR Identifiler kit was determined in nine Mexican Amerindian populations based on 1,040 unrelated individuals from the pre-Columbian region known as Mesoamerica. Hardy-Weinberg equilibrium was demonstrated for most of the short tandem repeats (STRs) in all nine populations. The power of discrimination and exclusion were higher than 0.99999 and 0.997942, respectively. In addition, a brief overview of the genetic relatedness and structure (F st = 2.62 %; p = 0.00000) between these populations is presented.
Assuntos
Frequência do Gene , Genética Populacional , Indígenas Norte-Americanos/genética , Repetições de Microssatélites , Impressões Digitais de DNA , Humanos , México , Reação em Cadeia da PolimeraseRESUMO
BACKGROUND: CODIS-STRs in Native Mexican groups have rarely been analysed for human identification and anthropological purposes. AIM: To analyse the genetic relationships and population structure among three Native Mexican groups from Mesoamerica. SUBJECTS AND METHODS: 531 unrelated Native individuals from Mexico were PCR-typed for 15 and 9 autosomal STRs (Identifiler™ and Profiler™ kits, respectively), including five population samples: Purépechas (Mountain, Valley and Lake), Triquis and Yucatec Mayas. Previously published STR data were included in the analyses. RESULTS: Allele frequencies and statistical parameters of forensic importance were estimated by population. The majority of Native groups were not differentiated pairwise, excepting Triquis and Purépechas, which was attributable to their relative geographic and cultural isolation. Although Mayas, Triquis and Purépechas-Mountain presented the highest number of private alleles, suggesting recurrent gene flow, the elevated differentiation of Triquis indicates a different origin of this gene flow. Interestingly, Huastecos and Mayas were not differentiated, which is in agreement with the archaeological hypothesis that Huastecos represent an ancestral Maya group. Interpopulation variability was greater in Natives than in Mestizos, both significant. CONCLUSION: Although results suggest that European admixture has increased the similarity between Native Mexican groups, the differentiation and inconsistent clustering by language or geography stresses the importance of serial founder effect and/or genetic drift in showing their present genetic relationships.
Assuntos
Etnicidade/genética , Indígenas Norte-Americanos/genética , Repetições de Microssatélites , Demografia , Genética Forense , Amplificação de Genes , Fluxo Gênico , Frequência do Gene , Deriva Genética , Marcadores Genéticos , Variação Genética , Genótipo , Geografia , Haplótipos , Humanos , México , Técnicas de Diagnóstico Molecular , Reação em Cadeia da Polimerase , População Branca/genéticaRESUMO
Mestizos currently represent most of the Mexican population (>90%); they are defined as individuals born in the country having a Spanish-derived last name, with family antecedents of Mexican ancestors back at least to the third generation. Mestizos are result of 500 years of admixture mainly among Spaniards, Amerindians, and African slaves. Consequently, a complex genetic pattern has been generated throughout the country that has been scarcely studied from the paternal point of view. This fact is important, taking into account that gene flow toward the New World comprised largely males. We analyzed the population structure and paternal admixture of present-day Mexican-Mestizo populations based on Y-STRs. We genotyped at least 12 Y-STRs in DNA samples of 986 males from five states: Aguascalientes (n = 293); Jalisco (n = 185); Guanajuato (n = 168); Chiapas (n = 170); and Yucatán (n = 170). AmpFlSTR Y-filer and Powerplex-Y(R) kits were used. Inclusion of North and Central Y-STR databases in the analyses allowed obtaining a Y-STR variability landscape from Mexico. Results confirmed the population differentiation gradient previously noted in Mestizos with SNPs and autosomal STRs throughout the Mexican territory: European ancestry increments to the Northwest and, correspondingly, Amerindian ancestry increments to the Center and Southeast. In addition, SAMOVA test and Autocorrelation Index for DNA Analysis autocorrelogram plot suggested preferential gene flow of males with neighboring populations in agreement with the isolation-by-distance model. Results are important for disease-risk studies (principally male-related) and for human identification purposes, because Y-STR databases are not available on the majority of Mexican-Mestizo populations.
Assuntos
População Negra/genética , Cromossomos Humanos Y/genética , Pai , Genética Populacional , Indígenas Sul-Americanos/genética , População Branca/genética , Fluxo Gênico , Frequência do Gene , Haplótipos , Humanos , Masculino , MéxicoRESUMO
The relationship between the microbial methylation of mercury and the microbial activities in sediments and water collected from the estuary of Bilbao (North of Spain) was studied in three different sampling points and in two different seasons. Three different cultures were prepared with a sediment slurry to distinguish between biotic and abiotic methylation pathways and the variations of the methylmercury concentration and the variations of the population of total number of bacteria (TDC), anaerobic heterotrophic bacteria (AHB), sulphate-reducing bacteria (SRB) and Desulfovibrio were measured. From this work, it can be concluded that the variation of MeHg concentrations is a result of the methylation/demethylation processes in the sediments, and that the abiotic processes have a negligible contribution to those processes. According to the statistical analysis of the results (partial least squares analysis) a significant statistical correlation was established between methylmercury and the SRB counts.
Assuntos
Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Microbiologia da Água , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Desulfovibrio/isolamento & purificação , Desulfovibrio/metabolismo , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Mercúrio/análise , Água do Mar , Poluentes do Solo/análise , Espanha , Poluentes Químicos da Água/análiseRESUMO
In Spain, there are more than 250,000 tractors built before 1980, when it became mandatory for all new tractors to be equipped with a rollover protective structure (ROPS). A similar situation is found in the European Union, but the situation is worse in the U.S. and in developing countries. Directive 2003/37/EEC establishes that tractors over 800 kg weight can be homologated by using the OECD standard code for the official testing of protective structures on agricultural and forestry tractors (static test), called Code 4. A ROPS attachable to the rear axle of different tractor models has been designed, and a computer program for the calculation of the ROPS design has been developed. The program, named ESTREMA, is available at: www.cfnavarra.es/insl. Using this program, it has been possible to design a ROPS for the Massey Ferguson model 178 tractor, one of the most common tractor models without a ROPS in Spain. After the tractor was equipped with the designed ROPS, it was tested at the Spanish Authorized Station for testing ROPS and passed the homologation test (OECD Code 4), the main results being a maximum distortion of 21.3 cm when the absorbed energy was 5437 N and the maximum force applied was 34 kN during loading from the side. The ROPS was improved, redesigned, and remounted on the tractor, the tractor was tested in a real overturn, and no part of the structure intruded on the driver's clearance zone during the test. In conclusion, the ESTREMA program worked correctly, and the designed ROPS was able to pass the authorized test and provide adequate protection to the operator during a real overturn.
Assuntos
Prevenção de Acidentes , Agricultura/instrumentação , Desenho de Equipamento , Segurança de Equipamentos , Veículos Off-Road/normas , Software/normas , Acidentes de Trabalho/prevenção & controle , Humanos , Modelos Teóricos , Veículos Off-Road/legislação & jurisprudência , Espanha , Ferimentos e Lesões/prevenção & controleRESUMO
Seasonal variations of polychaetes in a Thalassia testudinum bed were studied from June 2000 to April 2001 in Chacopata, northeastern Venezuela. Eight replicate samples were taken monthly with a 15 cm diameter core and the sediment was passed through a 0.5 mm mesh sieve. A total of 1,013 specimens, belonging to 35 species, was collected. The monthly density ranged from 387 ind/m2 (September) to 1,735 ind/m2 in May (x = 989+/-449 ind/m2). Species richness was lowest in August and September (8) and highest (25) in April (x = 18.00+/-5.29). The shoot density of Thalassia showed an average of 284+/-77.60 shoots/m2, with extreme values in February (164) and May (422). Species diversity ranged from 1.25 in August and 3.33 bits/ind in December (x = 2.47+/-0.64). Significant positive correlations were detected among the number of Thalassia shoots, polychaete abundance and species richness, as well as among species richness, polychaete abundance and species diversity. Species number and average density were found within the intervals of mean values reported in similar studies. The higher number of species and organisms obtained in March-April and June-July can be attributed to the recruitment correlated with the regional up-welling.
Assuntos
Animais , Biodiversidade , Ecossistema , Hydrocharitaceae , Poliquetos , Densidade Demográfica , Estações do Ano , VenezuelaRESUMO
We studied six Y-linked short tandem repeats (Y-STRs) to describe the internal diversity of the Amerindian haplogroup Q-M3 in 129 males from eight Mexican populations. The low gene diversity in the Huichol tribe demonstrated the effects of genetic drift, attributable to geographic isolation and founder effect. The presence of two principal paternal lineages supported the historical and anthropometric records, which indicate that Huichols were formed by the fusion of two ancestral Mexican tribes. Moreover, genetic distances and close relationships of haplotypes between Huichols and Tarahumaras were in agreement with their linguistic affiliation. The high genetic diversity of the Purépechas and wide distribution of haplotypes along the constructed network-joining tree suggest that the present genetic composition was influenced by Purépecha dominance in western Mesoamerica. The Y-haplotypes shared between populations suggest that, among the Amerindian tribes studied herein, the paternal genetic pool of Nahuas could have contributed more importantly to the European-admixed population, the Mexican-Mestizos.
Assuntos
Cromossomos Humanos Y , Etnicidade/genética , Genética Populacional , Haplótipos , Impressões Digitais de DNA , Frequência do Gene , Humanos , Masculino , México , Sequências de Repetição em TandemRESUMO
Three sibs with congenital glaucoma, skeletal anomalies, and peculiar facial appearance were studied. At birth, enlarged eyes and corneae were present in the proposita and her two brothers due to congenital glaucoma secondary to iridogoniodysgenesis (IGD). The purpose of this article is to describe the second familial case with IGD and skeletal anomalies as the family previously described by García-Cruz et al. in 1990, corroborating this new distinct dysmorphic syndrome with probable autosomal recessive inheritance.
Assuntos
Osso e Ossos/anormalidades , Fácies , Glaucoma/diagnóstico , Glaucoma/genética , Iris/anormalidades , Adulto , Osso e Ossos/diagnóstico por imagem , Anormalidades do Olho/diagnóstico , Anormalidades do Olho/genética , Feminino , Genes Recessivos , Humanos , Masculino , Radiografia , Irmãos , SíndromeRESUMO
We have used an Escherichia coli strain DH5a containing pGreenTIR to study the survival of this bacterium in river water. As green fluorescence was maintained throughout survival both in dark and illuminated conditions, gfp-tagged E. coli cells were clearly distinguished from the microbial community of the river Butrón. gfp-tagged E. coli cells were monitored to estimate total density as well as the density of the culturable and viable (active electron transport system, CTC+) cells. Our results indicate that autochthonous bacteria and introduced E. coli are predated by flagellates. The autochthonous bacterial community behaves as predation-escaping prey, showing a tendency to cellular miniaturization and so maintaining the density of the population. In contrast, introduced E. coli behaves as predation-non-escaping prey, so E. coli was eliminated from the system. When comparing the elimination by predation of heat-treated and non-heated gfp-tagged E. coli cells we deduce that the flagellates do not discriminate between live and heat-treated cells. Finally, in the presence of the river microbial community, the E. coli cells appeared to be ingested before cellular deterioration could occur. Thus predation reduces the quantitative importance of the viable but nonculturable (VBNC) population of E. coli in the aquatic systems.
Assuntos
Monitoramento Ambiental/métodos , Escherichia coli , Indicadores e Reagentes/análise , Proteínas Luminescentes/análise , Microbiologia da Água , Biomarcadores/análise , Cadeia Alimentar , Proteínas de Fluorescência Verde , Temperatura Alta , SobrevidaRESUMO
We studied the mechanisms by which photosynthetically active radiation (PAR) and ultraviolet (UV-A and UV-B) radiation damage Escherichia coli suspended in water. The roles played by oxygen and exogenous and endogenous sensitizers were analyzed by monitoring changes in the physiological state of irradiated cells. Impairment of the cellular functions was more severe in the case of UV radiations. Radiation caused cellular damage in the absence of oxygen. PAR, UV-A, and UV-B radiation induced photobiological and photodynamic reactions mediated by endogenous sensitizers, which significantly shortened the T90 (time needed to reduce a cellular parameter by 90%) based on the growth ability of the cells. In addition, when exogenous sensitizers were present, the photodynamic reactions also had a negative effect on the operation of the electron transport chains. The presence of oxygen might enhance photoinactivation, affecting both the growth ability and the electron transport chains. Endogenous sensitizers were responsible for the noxious action of oxygen. The presence of dissolved organic material played a protective role against the oxygen by absorbing the incident radiation, thereby reducing the energy that reached the endogenous sensitizers.
Assuntos
Escherichia coli/fisiologia , Fotossíntese , Raios Ultravioleta/efeitos adversos , Adsorção , Divisão Celular , Transporte de Elétrons , Escherichia coli/patogenicidade , Compostos Orgânicos , Oxigênio/metabolismo , FotoquímicaRESUMO
A male newborn with multiple congenital abnormalities was studied. Clinically, he showed prominent forehead, facial dysmorphism, ear malformations, congenital heart defect and limb anomalies. The cytogenetic studies demonstrated a karyotype 46,XY, der(18) t(1;18)(q32;p11.3)pat with partial trisomy 1q32-qter and a monosomy 18p. The patient displayed clinical features of trisomy 1q but not of monosomy 18p. There are around 80 reports of trisomy 1q32. The purpose of this paper is to describe the first case of a translocation involving 1q and 18p chromosome breakpoints. Additional findings detected in the propositus permit us a further delineation of the trisomy 1q syndrome.
Assuntos
Anormalidades Múltiplas/genética , Cromossomos Humanos Par 1/genética , Anormalidades Craniofaciais/genética , Trissomia/genética , Deleção Cromossômica , Cromossomos Humanos Par 18/genética , Evolução Fatal , Dedos/anormalidades , Cardiopatias Congênitas/genética , Humanos , Recém-Nascido , Cariotipagem , Masculino , Anormalidades da Pele/genética , SíndromeRESUMO
Diversity and abundance of benthic macrofauna associated to Thalassia testudinum were studied at Ensenada de Reyes, Mochima Bay, in the northeastern coast of Venezuela. Samples were taken monthly in six stations, three at 1 m in depth and three at 6 m, between December 1992 and February 1994, using a quadrat of 0.25 m2 for collecting plants and sediment; each sample was washed with seawater through a 1 mm sieve. The specimens were fixed in 6% formaldehyde. A total of 1722 organisms (6 888 ind x m2) and 127 species of macroinvertebrates were collected. Mollusks dominated with 53 species, followed by polychaetes (40), crustaceans (18) and echinoderms (8). Remaining groups were represented by 1-2 species. The highest abundance was in October (214 specimens), and the lowest in December 1993 (79 specimens). Specific richness was between 47 species in October and 18 in May 1993. Mean species diversity was 2.79-1.36 bits/ind. There were differences (ANOVA p<0.01) in number of specimens at the two depths but not throughout the 15 month study period (p>0.05). There were more specimens and species at the lowest depth and in stations with higher Thalassia testudinum biomass.
Assuntos
Animais , Biodiversidade , Biomassa , Hydrocharitaceae , Invertebrados/classificação , Estações do Ano , VenezuelaRESUMO
Cantú syndrome (CS) is characterized by congenital hypertrichosis, osteochondrodysplasia, cardiomegaly, and coarse facial appearance; autosomal recessive inheritance has been postulated. We report on a Mexican family with CS; the affected members are the 44-year-old father and his two children (a male and female), aged 14 and 4 years, respectively; each shows the classic characteristics, but the father and the brother also have a previously unreported feature, namely, a thick calvarium. This is the first reported instance of male-to-male transmission of CS. With the paternal age effect found in the reported sporadic cases and the segregation analysis [Robertson et al., 1999], autosomal dominant inheritance is more likely than autosomal recessive inheritance. The cases of affected sibs reported by Cantú et al. [1982] could be explained by parental gonadal mosaicism.
Assuntos
Cardiomegalia/patologia , Genes Dominantes , Hipertricose/patologia , Osteocondrodisplasias/patologia , Adolescente , Adulto , Cardiomegalia/genética , Pré-Escolar , Saúde da Família , Feminino , Humanos , Hipertricose/congênito , Hipertricose/genética , Masculino , Osteocondrodisplasias/genética , LinhagemRESUMO
Quantitative and qualitative changes in organic matter content of wastewater effluents attributable to chlorination and ozonation have been analysed using bioassays as well as organic carbon direct measures. Bioassays were carried out using the bacterial populations of wastewater and two Escherichia coli strains as test micro-organisms. Our results indicate that pure strains present some advantages over indigenous bacteria. Although wastewater bacterial populations are better adapted to growth in wastewater, E. coli strains are more sensitive to changes in dissolved organic carbon (DOC) content. Moreover, the use of pure cultures allows estimation of the portion of DOC which can be converted in cell biomass, the assimilable organic carbon (AOC). Finally, the results obtained using prototrophic and the auxotrophic strains of E. coli suggested that ozonation alters the amino acid composition of wastewater while chlorination does not change the quantity nor the quality of the DOC present in effluents.
Assuntos
Bactérias/crescimento & desenvolvimento , Carbono/metabolismo , Desinfecção/métodos , Esgotos/química , Purificação da Água/métodos , Bioensaio , Escherichia coli/crescimento & desenvolvimento , Ozônio/farmacologia , Esgotos/microbiologia , Hipoclorito de Sódio/farmacologiaRESUMO
An intracranial cell squamous carcinoma was found in a 27-year-old Mexican woman with Bloom syndrome (BS), including growth retardation, sun-sensitive telangiectatic erythema, defective immunity, and increased number of mitotic chiasmata and sister chromatid exchanges. The tumour, probably originating from the inner or middle ear epithelium, was resected but the patient died a few days after surgery. There was no parental consanguinity nor Jewish or European ancestry for at least five generations; in fact, her parents were mostly indigenous people. This case represents an undescribed intracranial malignancy in BS and the third Mexican BS patient reported. The typical BS phenotype in a woman with pigmented skin challenges the contention that pigmented females are less severely affected.