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1.
Biol Lett ; 19(11): 20230343, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37909055

RESUMEN

The woolly rhinoceros (Coelodonta antiquitatis) is an iconic species of the Eurasian Pleistocene megafauna, which was abundant in Eurasia in the Pleistocene until its demise beginning approximately 10 000 years ago. Despite the early recovery of several specimens from well-known European archaeological sites, including its type specimen (Blumenbach 1799), no genomes of European populations were available so far, and all available genomic data originated exclusively from Siberian populations. Using coprolites of cave hyenas (Crocuta crocuta spelea) recovered from Middle Palaeolithic layers of two caves in Germany (Bockstein-Loch and Hohlenstein-Stadel), we isolated and enriched predator and prey DNA to assemble the first European woolly rhinoceros mitogenomes, in addition to cave hyena mitogenomes. Both coprolite samples produced copious sequences assigned to C. crocuta (27% and 59% mitogenome coverage, respectively) and woolly rhinoceros (Coelodonta antiquitatis; 27% and 81% coverage, respectively). The sequences suggested considerable DNA degradation, which may limit the conclusions to be drawn; however, the mitogenomes of European woolly rhinoceros are genetically distinct from the Siberian woolly rhinoceros, and analyses of the more complete mitogenome suggest a split of the populations potentially coinciding with the earliest fossil records of woolly rhinoceros in Europe.


Asunto(s)
Genoma Mitocondrial , Hyaenidae , Animales , Filogenia , Hyaenidae/genética , ADN , Perisodáctilos/genética , Perisodáctilos/metabolismo , Fósiles
2.
BMC Womens Health ; 22(1): 506, 2022 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-36482357

RESUMEN

BACKGROUND: Reproductive decision-making is difficult for BRCA-positive women. Our objective was to assess the complexities of decision-making and identify decisional supports for patients and providers when discussing reproductive options prior to risk-reducing salpingo-oophorectomy (RRSO). METHODS: This study was of qualitive design, using data collection via semi-structured interviews conducted from November 2018 to October 2020. Individuals were included if they were identified to provide care to BRCA-positive women. In total, 19 providers were approached and 15 consented to participate. Providers were recruited from three clinics in Toronto, Ontario located at academic centers: [1] A familial ovarian cancer clinic, [2] A familial breast cancer clinic and [3] A fertility clinic, all of which treat carriers of the BRCA1/BRCA2 genetic mutation. The interview guide was developed according to the Ottawa Decision Support Framework and included questions regarding reproductive options available to patients, factors that impact the decision-making process and the role of decisional support. Interviews were transcribed and transcripts were analyzed thematically using NVIVO 12. RESULTS: Providers identified three major decisions that reproductive-aged women face when a BRCA mutation is discovered: [1] "Do I want children?"; [2] "Do I want to take the chance of passing on this the mutation?"; and [3] "Do I want to carry a child?" Inherent decision challenges that are faced by both providers and patients included difficult decision type, competing options, scientifically uncertain outcomes, and challenging decision timing. Modifiable decisional needs included: inadequate knowledge, unrealistic expectations, unclear values and inadequate support or resources. Identified clinical gaps included counselling time constraints, lack of reliable sources of background information for patients or providers and need for time-sensitive, geographically accessible, and centralized care. CONCLUSION: Our study identified a need for a patient information resource that can be immediately provided to patients who carry a BRCA genetic mutation. Other suggestions for clinical practice include more time during consultation appointments, adequate follow-up, value-centric counseling, access to psychosocial support, and a specialized decisional coach.


Asunto(s)
Niño , Humanos , Femenino , Adulto , Ontario
3.
Geophys Res Lett ; 46(16): 9930-9939, 2019 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-31762520

RESUMEN

Investigation of organic compounds in ice cores can potentially unlock a wealth of new information in these climate archives. We present results from the first ever ice core drilled on sub-Antarctic island Bouvet, representing a climatologically important but understudied region. We analyze a suite of novel and more familiar organic compounds in the ice core, alongside commonly measured ions. Methanesulfonic acid shows a significant, positive correlation to winter sea ice concentration, as does a fatty acid compound, oleic acid. Both may be sourced from spring phytoplankton blooms, which are larger following greater sea ice extent in the preceding winter. Oxalate, formate, and acetate are positively correlated to sea ice concentration in summer, but sources of these require further investigation. This study demonstrates the potential application of organic compounds from the marine biosphere in generating multiproxy sea ice records, which is critical in improving our understanding of past sea ice changes.

4.
Reproduction ; 157(1): 101-109, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30390611

RESUMEN

Primordial germ cells (PGCs) are the embryonic precursors of spermatozoa and eggs. In mammals, PGCs arise early in embryonic development and migrate from their tissue of specification over a significant distance to reach their destinations, the genital ridges. However, the exact mechanism of translocation is still debated. A study on human embryos demonstrated a very close spatial association between migrating PGCs and developing peripheral nerves. Thus, it was proposed that peripheral nerves act as guiding structures for migrating PGCs. The goal of the present study is to test whether the association between nerves and PGCs may be a human-specific finding or whether this represents a general strategy to guide PGCs in mammals. Therefore, we investigated embryos of different developmental stages from the mouse and a non-human primate, the marmoset monkey (Callithrix jacchus), covering the phase from PGC emergence to their arrival in the gonadal ridge. Embryo sections were immunohistochemically co-stained for tubulin beta-3 chain (TUBB3) to visualise neurons and Octamer-binding protein 4 (OCT4 (POU5F1)) as marker for PGCs. The distance between PGCs and the nearest detectable neuron was measured. We discovered that in all embryos analysed of both species, the majority of PGCs (>94%) was found at a minimum distance of 50 µm to the closest neuron and, more importantly, that the PGCs had reached the gonads before any TUBB3 signal could be detected in the vicinity of the gonads. In conclusion, our data indicate that PGC migration along peripheral nerves is not a general mechanism in mammals.


Asunto(s)
Callithrix/embriología , Movimiento Celular , Desarrollo Embrionario/fisiología , Células Germinativas/fisiología , Ratones/embriología , Fibras Nerviosas/fisiología , Animales , Animales Recién Nacidos , Embrión de Mamíferos , Femenino , Edad Gestacional , Masculino , Embarazo
5.
Nature ; 542(7642): 427-432, 2017 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-28230118

RESUMEN

The pacing of glacial-interglacial cycles during the Quaternary period (the past 2.6 million years) is attributed to astronomically driven changes in high-latitude insolation. However, it has not been clear how astronomical forcing translates into the observed sequence of interglacials. Here we show that before one million years ago interglacials occurred when the energy related to summer insolation exceeded a simple threshold, about every 41,000 years. Over the past one million years, fewer of these insolation peaks resulted in deglaciation (that is, more insolation peaks were 'skipped'), implying that the energy threshold for deglaciation had risen, which led to longer glacials. However, as a glacial lengthens, the energy needed for deglaciation decreases. A statistical model that combines these observations correctly predicts every complete deglaciation of the past million years and shows that the sequence of interglacials that has occurred is one of a small set of possibilities. The model accounts for the dominance of obliquity-paced glacial-interglacial cycles early in the Quaternary and for the change in their frequency about one million years ago. We propose that the appearance of larger ice sheets over the past million years was a consequence of an increase in the deglaciation threshold and in the number of skipped insolation peaks.

6.
Nat Commun ; 6: 7850, 2015 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-26204562

RESUMEN

Relief of iron (Fe) limitation in the Southern Ocean during ice ages, with potentially increased carbon storage in the ocean, has been invoked as one driver of glacial-interglacial atmospheric CO2 cycles. Ice and marine sediment records demonstrate that atmospheric dust supply to the oceans increased by up to an order of magnitude during glacial intervals. However, poor constraints on soluble atmospheric Fe fluxes to the oceans limit assessment of the role of Fe in glacial-interglacial change. Here, using novel techniques, we present estimates of water- and seawater-soluble Fe solubility in Last Glacial Maximum (LGM) atmospheric dust from the European Project for Ice Coring in Antarctica (EPICA) Dome C and Berkner Island ice cores. Fe solubility was very variable (1-42%) during the interval, and frequently higher than typically assumed by models. Soluble aerosol Fe fluxes to Dome C at the LGM (0.01-0.84 mg m(-2) per year) suggest that soluble Fe deposition to the Southern Ocean would have been ≥10 × modern deposition, rivalling upwelling supply.

7.
Ecotoxicol Environ Saf ; 101: 7-13, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24507120

RESUMEN

Exposure to Bisphenol A (BPA) has been reported to dysregulate endocrine pathways in a wide array of vertebrate species. The effects of BPA on invertebrate species are less well understood. We tested the effects of BPA on growth and development in Drosophila as these processes are governed by well-studied endocrine pathways. In this study, we tested the effects of three concentrations of BPA (0.1mg/L, 1mg/L or 10mg/L) and found a statistically significant increase in larval growth for the low dose treatment group (0.1mg/L), but not statistically significant for the high dose treatment group (10mg/L). BPA exposure resulted in an increased body size in treated animals at 48, 72 and 96h after egg laying (AEL). This finding reflects a non-monotonic dose-response that has been observed for an increasing number of endocrine disrupting compounds. The increase in growth rate found for all treatment groups was associated with a statistically significant increase in food intake observed at 72h AEL. Furthermore, we observed that the increased growth rate was coupled with an earlier onset of pupariation consistent with previously reported phenotypes resulting from increased activity of insulin/insulin growth factor signaling (IIS) in Drosophila. Since the timing of the onset of pupariation in Drosophila is controlled through the complex interaction of the IIS and the ecdysone signaling pathways, our findings suggest that BPA exerts its effects through disruption of endocrine signaling in Drosophila.


Asunto(s)
Compuestos de Bencidrilo/toxicidad , Drosophila melanogaster/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Metamorfosis Biológica/efectos de los fármacos , Fenoles/toxicidad , Animales , Ingestión de Alimentos/efectos de los fármacos , Larva , Pupa , Transducción de Señal/efectos de los fármacos
8.
Amino Acids ; 44(1): 103-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22139412

RESUMEN

Eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains the unusual amino acid hypusine [N(ε)-(4-amino-2-hydroxybutyl)lysine]. The role of hypusine formation in the eIF5A protein in the regulation of cell proliferation and apoptosis is addressed in the present review. Moreover, vertebrates carry two genes that encode two eIF5A isoforms, eIF5A-1 and eIF5A-2, which, in humans, are 84% identical. However, the biological functions of these two isoforms may be significantly different. In fact, eIF5A-1 is demonstrable in most cells of different histogenesis, whereas eIF5A-2 protein is detectable only in certain human cancer cells or tissues, suggesting its role as a potential oncogene. In this review we focus our attention on the involvement of eIF5A-1 in the triggering of an apoptotic program and in the regulation of cell proliferation. In addition, the potential oncogenic role and prognostic significance of eIF5A-2 in the prediction of the survival of cancer patients is described. eIF5A-1 and/or the eIF5A-2 isoform may serve as a new molecular diagnostic or prognostic marker or as a molecular target for anti-cancer therapy.


Asunto(s)
Neoplasias/metabolismo , Factores de Iniciación de Péptidos/genética , Proteínas de Unión al ARN/genética , Animales , Apoptosis , Transformación Celular Neoplásica/metabolismo , Expresión Génica , Humanos , Lisina/análogos & derivados , Lisina/biosíntesis , Neoplasias/patología , Factores de Iniciación de Péptidos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas de Unión al ARN/metabolismo , Factor 5A Eucariótico de Iniciación de Traducción
9.
Herzschrittmacherther Elektrophysiol ; 22(4): 226-32, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22160274

RESUMEN

AIMS: Atrial fibrillation (AF) is a relevant comorbidity in heart failure (HF) patients. In milestone cardiac resynchronization therapy (CRT) studies, patients with AF were excluded. We sought to investigate the influence of chronic atrial fibrillation (AF) on patients with CRT. AV node (AVN) ablation is frequently recommended. Converting AF to sinus rhythm (SR) is not a standard concept. METHODS: A total of 584 consecutive patients with CRT devices were included in a single-center registry from 1999-2006 (retrospective registry) and 127/324 patients from 2007-06/2008 (prospective registry). The impact of persistent AF (group 1) on clinical and echocardiographic improvement compared with patients in SR (group 2) after 12 (6) months follow-up were analyzed. Re-establishing SR after initial cardioversion or need for AVN ablation was examined. RESULTS: In the retrospective registry, 139 (24%) patients presented with AF (group 1) and 445 with SR (group 2). The groups differed in age, gender, and left atrium (LA) size but not in NYHA class, ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD), B-type natriuretic peptide (BNP) levels, QRS width, and underlying disease. After 1 year, CRT improvement of NYHA class and EF was similar with higher mortality in group 1 (12% vs. 7%; OR 1.80; 95% confidence interval 0.95-3.4). The AF group presented with SR in 33/82 (40%) patients and 11% needed AVN ablation. The prospective data showed 27 (21%) patients in AF with conversion to SR in 41% after 6 months. CONCLUSION: Patients with severe HF and chronic AF had a comparable improvement with CRT as those in SR. CRT is a successful treatment option in patients with chronic AF offering the potential to restore SR in a significant number of patients.


Asunto(s)
Fibrilación Atrial/mortalidad , Fibrilación Atrial/prevención & control , Terapia de Resincronización Cardíaca/mortalidad , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/prevención & control , Anciano , Enfermedad Crónica , Comorbilidad , Femenino , Alemania/epidemiología , Humanos , Incidencia , Masculino , Pronóstico , Sistema de Registros/estadística & datos numéricos , Medición de Riesgo/métodos , Factores de Riesgo , Análisis de Supervivencia , Tasa de Supervivencia
10.
Nature ; 462(7271): 342-5, 2009 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-19924212

RESUMEN

Stable isotope ratios of oxygen and hydrogen in the Antarctic ice core record have revolutionized our understanding of Pleistocene climate variations and have allowed reconstructions of Antarctic temperature over the past 800,000 years (800 kyr; refs 1, 2). The relationship between the D/H ratio of mean annual precipitation and mean annual surface air temperature is said to be uniform +/-10% over East Antarctica and constant with time +/-20% (refs 3-5). In the absence of strong independent temperature proxy evidence allowing us to calibrate individual ice cores, prior general circulation model (GCM) studies have supported the assumption of constant uniform conversion for climates cooler than that of the present day. Here we analyse the three available 340 kyr East Antarctic ice core records alongside input from GCM modelling. We show that for warmer interglacial periods the relationship between temperature and the isotopic signature varies among ice core sites, and that therefore the conversions must be nonlinear for at least some sites. Model results indicate that the isotopic composition of East Antarctic ice is less sensitive to temperature changes during warmer climates. We conclude that previous temperature estimates from interglacial climates are likely to be too low. The available evidence is consistent with a peak Antarctic interglacial temperature that was at least 6 K higher than that of the present day -approximately double the widely quoted 3 +/- 1.5 K (refs 5, 6).

11.
Appl Biochem Biotechnol ; 151(2-3): 402-12, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18830827

RESUMEN

The objectives of this work were to evaluate the antimicrobial and antineoplasic activity of Pleurotus ostreatus DSM 1833. To study the antimicrobial activity, the following extracts were prepared: water infusion of the fresh fruiting bodies (B1), dehydrated fruiting bodies (B2), fresh mycelium (M1), and dehydrated mycelium (M2). Polysaccharides from the fresh mycelium were also obtained by water infusion followed by ethanol treatment (EP). The extracts were tested against Candida albicans, Escherichia coli, and Bacillus subtilis. To investigate the antineoplasic effect of P. ostreatus, the culture broth in natura, the extract from the culture broth (ECB), and the extract from the fruiting bodies were tested in female Swiss albino mice inoculated with the Ehrlich ascitic tumor (EAT). B1, B2, and M1 showed more than 50.0% inhibition against C. albicans. M2 presented a high degree of inhibition against E. coli (87.5%) and B. subtilis (57.5%), while EP was not effective. All the tested substances inhibited the development of EAT at levels near 70% when injected intraperitoneally in mice. The highest tumor inhibition (76%) was achieved for the treatment with ECB. The intragastric treatment did not promote any reduction in tumor cell development, independent of the test substance.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Candida albicans/efectos de los fármacos , Pleurotus , Animales , Bacillus subtilis/efectos de los fármacos , Carcinoma de Ehrlich/tratamiento farmacológico , Escherichia coli/efectos de los fármacos , Femenino , Cuerpos Fructíferos de los Hongos , Pruebas de Sensibilidad Microbiana , Micelio , Ratas
12.
Rapid Commun Mass Spectrom ; 21(19): 3175-9, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17768697

RESUMEN

We have developed a validated gas chromatography/mass spectrometry (GC/MS) method with two labelled cholesterol tracers, i.e. (2)H(4) ([2H4]-Chol) and (2)H(7) ([2H7]-Chol) enriched moieties, with a new way of calculating the abundance of labelled cholesterol in plasma without natural cholesterol interference. The isotopomers of the analytes could interfere during analysis. Elimination of these interferences can be performed by the blank or mathematical subtraction method. Validation was performed with the two interference elimination methods. For both methods, linearity was obtained in the range 5 x 10(-4) to 10(-2) mM for both labelled cholesterol moieties. In the same range, repeatability and reproducibility were less than 6.5% and 7.5% for [2H4]-Chol and [2H7]-Chol, respectively. Accuracy was about 100% and recoveries always included 100% for the two labelled cholesterols. We demonstrate that measurement of blank plasma is not necessary when using the validated abundance isotope calculation method. This saves time, reagent and samples. This calculation strategy can be extrapolated to comparable tracer approaches.


Asunto(s)
Artefactos , Análisis Químico de la Sangre/métodos , Colesterol/sangre , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Marcaje Isotópico/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
13.
Science ; 317(5839): 793-6, 2007 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-17615306

RESUMEN

A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, approximately 800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.

14.
Amino Acids ; 33(2): 341-50, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17476569

RESUMEN

A naturally occurring unusual amino acid, hypusine [N (epsilon)-(4-amino-2-hydroxybutyl)-lysine] is a component of a single cellular protein, eukaryotic translation initiation factor 5A (eIF5A). It is a modified lysine with structural contribution from the polyamine spermidine. Hypusine is formed in a novel posttranslational modification that involves two enzymes, deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). eIF5A and deoxyhypusine/hypusine modification are essential for growth of eukaryotic cells. The hypusine synthetic pathway has evolved in eukaryotes and eIF5A, DHS and DOHH are highly conserved, suggesting maintenance of a fundamental cellular function of eIF5A through evolution. The unique feature of the hypusine modification is the strict specificity of the enzymes toward its substrate protein, eIF5A. Moreover, DHS exhibits a narrow specificity toward spermidine. In view of the extraordinary specificity and the requirement for hypusine-containing eIF5A for mammalian cell proliferation, eIF5A and the hypusine biosynthetic enzymes present new potential targets for intervention in aberrant cell proliferation.


Asunto(s)
Lisina/análogos & derivados , Secuencia de Aminoácidos , Animales , Sitios de Unión , Evolución Biológica , Humanos , Lisina/biosíntesis , Oxigenasas de Función Mixta/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/antagonistas & inhibidores , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Factores de Elongación de Péptidos/fisiología , Factores de Iniciación de Péptidos/genética , Factores de Iniciación de Péptidos/metabolismo , Factores de Iniciación de Péptidos/fisiología , Procesamiento Proteico-Postraduccional/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Alineación de Secuencia , Espermidina/metabolismo , Especificidad por Sustrato , Factor 5A Eucariótico de Iniciación de Traducción
15.
Pediatr Transplant ; 10(2): 193-7, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16573606

RESUMEN

Between 1989 and 2003, 100 transplants were performed in 96 patients at the pediatric nephrology unit of the Calvo Mackenna Children's Hospital. Mean age 10.9 +/- 3.9 yr (1-17.6), 30% from LD. Donors were younger than 5 yr in five patients and all recipients received an 'en bloc' graft. Original disease was hypo/dysplasia 27%, reflux nephropathy 22 and 17% chronic glomerulonephritis. The immunosuppressive protocol during the first period (n = 56, 1989-2000): Cyclosporine, steroids and azathioprine, and during the second period (n = 44, 2001-2003): FK, steroids, MMF and anti-CD25 antibody (mAbs). AR was reported in 22 patients, 11% in LD, 31% in DD (p < 0.01). The AR rate decreased from 40 to 8% after anti-CD25 monoclonal induction. Patient actuarial survival rate at 1, 3 and 5 yr was 100% for LD and 96% for DD. The overall actuarial graft survival at 1,3, and 5 yr was 96.7, 96.7 and 71% for LD and 89, 76 and 73% for DD donors. Graft survival rate improved from the first period (1989-2000) to the second period (2001-2003; p = 0.05). No difference in graft survival rate with HLA-A,B,DR matching was found. Graft survival rate was better when cold ischemia time was <24 h (p < 0.01). CMV infections increased from 19 to 40% when MMF and anti-CD25 Ab were introduced (p < 0.01). The height/age Z score at 1, 3 and 5 yr post-transplant was -2.2, -2.1, -2.2, respectively, for children older than 7 yr and -1.8, -1.9, -2.1 for those transplanted younger than 7 yr of age who were switched to alternate day steroids (p < 0.01). The cause of graft lost was: chronic rejection eight, non-adherence four, AR four and vascular thrombosis two. The cause of death in two patients was fungus septicemia and accelerated rejection. Pediatric renal transplantation can be performed in our group with acceptable morbidity, low mortality and graft survival rates similar to other reports in North America and Western Europe. Graft survival rate improved with newer immunosuppression and greater experience at the center. Management of non-adherence and chronic rejection remain the major challenges.


Asunto(s)
Trasplante de Riñón , Adolescente , Preescolar , Enfermedad Crónica , Femenino , Glomerulonefritis/cirugía , Supervivencia de Injerto , Humanos , Inmunosupresores/uso terapéutico , Lactante , Masculino , Estudios Retrospectivos , Factores de Tiempo
16.
Nature ; 440(7083): 491-6, 2006 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-16554810

RESUMEN

Sea ice and dust flux increased greatly in the Southern Ocean during the last glacial period. Palaeorecords provide contradictory evidence about marine productivity in this region, but beyond one glacial cycle, data were sparse. Here we present continuous chemical proxy data spanning the last eight glacial cycles (740,000 years) from the Dome C Antarctic ice core. These data constrain winter sea-ice extent in the Indian Ocean, Southern Ocean biogenic productivity and Patagonian climatic conditions. We found that maximum sea-ice extent is closely tied to Antarctic temperature on multi-millennial timescales, but less so on shorter timescales. Biological dimethylsulphide emissions south of the polar front seem to have changed little with climate, suggesting that sulphur compounds were not active in climate regulation. We observe large glacial-interglacial contrasts in iron deposition, which we infer reflects strongly changing Patagonian conditions. During glacial terminations, changes in Patagonia apparently preceded sea-ice reduction, indicating that multiple mechanisms may be responsible for different phases of CO2 increase during glacial terminations. We observe no changes in internal climatic feedbacks that could have caused the change in amplitude of Antarctic temperature variations observed 440,000 years ago.


Asunto(s)
Ambiente , Hielo , Hierro , Calcio/análisis , Clima , Hierro/análisis , Biología Marina , Mesilatos/análisis , Océanos y Mares , Periodicidad , Sodio/análisis , América del Sur
17.
J Perinatol ; 26(2): 135-7, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16435009

RESUMEN

Endometrial ablation has become a popular method of managing menorrhagia. Pregnancy after endometrial ablation has a high rate of complications. We present the case of a parous woman with a history of endometrial ablation with preterm premature rupture of membranes. Despite the absence of established sonographic markers for abnormal placentation, placenta accreta was noted at the time of cesarean delivery. In women with history of endometrial ablation, the endometrium is not normal and may allow for more aggressive placental invasion or adherence. Consequently, the sonographic indices described for evaluating placenta accreta may not be present. We believe that placentation in women with prior endometrial ablations should be considered extremely high risk for placenta accreta or increta and managed accordingly when preparing for delivery.


Asunto(s)
Ablación por Catéter/métodos , Endometrio/cirugía , Rotura Prematura de Membranas Fetales/cirugía , Histerectomía/métodos , Placenta Accreta/cirugía , Resultado del Embarazo , Adulto , Cesárea , Terapia Combinada , Endometrio/patología , Femenino , Rotura Prematura de Membranas Fetales/diagnóstico por imagen , Estudios de Seguimiento , Humanos , Paridad , Placenta Accreta/diagnóstico por imagen , Embarazo , Tercer Trimestre del Embarazo , Medición de Riesgo , Ultrasonografía Prenatal/métodos
18.
Cytogenet Genome Res ; 101(2): 106-12, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14610349

RESUMEN

35 oral squamous cell carcinomas examined previously by comparative genomic hybridization (CGH) exhibited 5 up to 47 copy number alterations (CNAs). 13 of those cases showed a loss of parts of the short arm of chromosome 9, band p21 being affected in all of these cases. A highly complex but strikingly consistent pattern of genomic imbalances with an average 31.5 CNAs per tumor was associated with this deletion, and gains clearly dominated over losses of genomic material. Comparable patterns, however, could also be found in tumors with a high number of CNAs (24 CNAs) but without the deletion. Low numbers of imbalances were accompanied by low consistency of the CNA patterns. None of these latter cases showed the deletion 9p21. 66.7% of the dim(9p21)-positive tumors were of class pT4 (vs. 22% in dim(9p21)-negative cases), 77% of stage III or IV (vs. 47% in the group without the deletion), but only 8% of the dim(9p21)-positive tumors were classified as grade 3 (vs. 41% in the negative group). Other clinicopathologic features like prevalence of relapse, or survival time could not be as clearly associated with the deletion. For instance, short relapse-free survival was clearly associated with a high number of CNAs, rather independent of presence or absence of dim(9p21) in the affected tumor. From these findings it is concluded that previously found associations of 9p21 deletion with clinical parameters can reasonably be estimated only in the context of the pattern and complexity of the genomic imbalances accompanying this chromosomal loss in the examined tumors.


Asunto(s)
Carcinoma de Células Escamosas/genética , Deleción Cromosómica , Cromosomas Humanos Par 9 , Neoplasias de la Boca/genética , Adulto , Anciano , Carcinoma de Células Escamosas/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/diagnóstico , Hibridación de Ácido Nucleico
19.
Mem Inst Oswaldo Cruz ; 97(5): 667-73, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12219133

RESUMEN

The finding of Panstrongylus geniculatus nymphs inside a house in northeastern Antioquia, Colombia, and the reports related to their increasing presence in homes suggest the need for surveillance methods for monitoring the invasion processes. We analyzed the morphological differences between a wild population and its laboratory descendants, using the techniques of geometric morphometry, with the idea that such differences might parallel those between sylvatic and synanthropic populations. The analyses over five generations showed differences in size but not in shape. Head size and wing size were both reduced from sylvatic to laboratory populations, but the decrease in head size occurred only up to the second generation while the decrease in wing size proceeded up to the fifth generation. In contrast, although a decrease in sexual size dimorphism has been proposed as a marker of colonization in human dwellings, we did not detect any significant loss of dimorphism between sexes of P. geniculatus over the five generations studied. We conclude that size changes may have a physiological origin in response to a change of ecotopes, but more than five generations may be required for the expression of permanent morphological markers of human dwellings colonization.


Asunto(s)
Panstrongylus/anatomía & histología , Animales , Constitución Corporal , Distribución de Chi-Cuadrado , Femenino , Cabeza/anatomía & histología , Masculino , Panstrongylus/genética , Panstrongylus/crecimiento & desarrollo , Análisis de Componente Principal , Caracteres Sexuales , Alas de Animales/anatomía & histología
20.
Mem. Inst. Oswaldo Cruz ; 97(5): 667-673, July 2002. ilus, tab, graf
Artículo en Inglés | LILACS | ID: lil-321192

RESUMEN

The finding of Panstrongylus geniculatus nymphs inside a house in northeastern Antioquia, Colombia, and the reports related to their increasing presence in homes suggest the need for surveillance methods for monitoring the invasion processes. We analyzed the morphological differences between a wild population and its laboratory descendants, using the techniques of geometric morphometry, with the idea that such differences might parallel those between sylvatic and synanthropic populations. The analyses over five generations showed differences in size but not in shape. Head size and wing size were both reduced from sylvatic to laboratory populations, but the decrease in head size occurred only up to the second generation while the decrease in wing size proceeded up to the fifth generation. In contrast, although a decrease in sexual size dimorphism has been proposed as a marker of colonization in human dwellings, we did not detect any significant loss of dimorphism between sexes of P. geniculatus over the five generations studied. We conclude that size changes may have a physiological origin in response to a change of ecotopes, but more than five generations may be required for the expression of permanent morphological markers of human dwellings colonization


Asunto(s)
Animales , Masculino , Femenino , Panstrongylus , Constitución Corporal , Distribución de Chi-Cuadrado , Cabeza , Laboratorios , Panstrongylus , Análisis de Componente Principal , Caracteres Sexuales , Alas de Animales/anatomía & histología
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