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1.
Nature ; 555(7695): 216-219, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29516997

RESUMO

The familiar axisymmetric zones and belts that characterize Jupiter's weather system at lower latitudes give way to pervasive cyclonic activity at higher latitudes. Two-dimensional turbulence in combination with the Coriolis ß-effect (that is, the large meridionally varying Coriolis force on the giant planets of the Solar System) produces alternating zonal flows. The zonal flows weaken with rising latitude so that a transition between equatorial jets and polar turbulence on Jupiter can occur. Simulations with shallow-water models of giant planets support this transition by producing both alternating flows near the equator and circumpolar cyclones near the poles. Jovian polar regions are not visible from Earth owing to Jupiter's low axial tilt, and were poorly characterized by previous missions because the trajectories of these missions did not venture far from Jupiter's equatorial plane. Here we report that visible and infrared images obtained from above each pole by the Juno spacecraft during its first five orbits reveal persistent polygonal patterns of large cyclones. In the north, eight circumpolar cyclones are observed about a single polar cyclone; in the south, one polar cyclone is encircled by five circumpolar cyclones. Cyclonic circulation is established via time-lapse imagery obtained over intervals ranging from 20 minutes to 4 hours. Although migration of cyclones towards the pole might be expected as a consequence of the Coriolis ß-effect, by which cyclonic vortices naturally drift towards the rotational pole, the configuration of the cyclones is without precedent on other planets (including Saturn's polar hexagonal features). The manner in which the cyclones persist without merging and the process by which they evolve to their current configuration are unknown.

2.
J Endocrinol Invest ; 46(12): 2459-2469, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37095269

RESUMO

BACKGROUND: Standard thyroid function parameters reference intervals (RI) are unsuitable during pregnancy, potentially resulting in incongruous treatments that may cause adverse effects on pregnancy outcomes. We aimed at defining trimester-specific TSH, FT4 and FT3 RI, using samples longitudinally collected from healthy Caucasian women. MATERIALS AND METHODS: Blood samples from 150 healthy Caucasian women, who had a physiological gestation and a healthy newborn at term, were collected in each trimester and at around six months post-partum. They showed mild iodine deficiency. After excluding women with overt TSH abnormalities (> 10 mU/L) and/or TPO antibodies, data from 139 pregnant women were analyzed by means of widely used Roche platforms, and TSH, FT4 and FT3 trimester-specific RI were calculated. Post-partum data were available for 55 subjects. RESULTS: Serum TSH RI were 0.34-3.81 mU/L in the first trimester, and changed slightly to 0.68-4.07 U/L and 0.63-4.00 mU/L in the second and third trimester, respectively. Conversely, both FT4 and FT3 concentrations progressively decreased during pregnancy, the median values in the third trimester being 14.8% and 13.2% lower, respectively, than in the first trimester. Thyroid function parameters in the first trimester were similar to those measured after the end of pregnancy. CONCLUSIONS: This study calculates trimester-specific RI for thyroid function parameters in pregnancy, and proposes the reference limits that should be adopted when using Roche platforms in Caucasian women.


Assuntos
Glândula Tireoide , Tiroxina , Recém-Nascido , Gravidez , Feminino , Humanos , Glândula Tireoide/fisiologia , Testes de Função Tireóidea/métodos , Estudos Prospectivos , Gestantes , Tireotropina , Valores de Referência , Primeiro Trimestre da Gravidez , Resultado da Gravidez
3.
J Endocrinol Invest ; 46(12): 2629-2637, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37256493

RESUMO

PURPOSE: PCOS is associated with low grade inflammation which could play a role in insulin resistance and ovarian dysfunction. Preliminary findings suggested that serum levels of HMGB1, a cytokine involved in inflammation, might be altered in women with PCOS. Primary aim of this study was to assess whether HMGB1 serum concentrations are associated with PCOS and with the state of insulin resistance of these women. METHODS: Sixty women with PCOS, selected to have a similar proportion of subjects with altered or normal insulin sensitivity, and 29 healthy controls were studied. Serum HMGB1 levels were compared in subgroups of PCOS women and controls. In PCOS women, insulin sensitivity was assessed by the glucose clamp technique and HMGB1 was measured at baseline and after acute hyperinsulinemia. RESULTS: HMGB1 levels were similar in women with PCOS and controls and no elements used for diagnosing PCOS were associated with serum HMGB1. However, HMGB1 concentrations were higher in insulin-resistant vs insulin-sensitive PCOS women (p = 0.017), and inversely associated with insulin-induced total and non-oxidative glucose metabolism. In both subgroups of PCOS women, serum HMBG1 levels significantly increased after acute hyperinsulinemia. CONCLUSIONS: These data suggest that HMGB1 levels are not associated with PCOS per se, but with insulin resistance. Further research should establish the underlying nature of this relationship, and whether this protein might play a role in the metabolic complications of PCOS.


Assuntos
Proteína HMGB1 , Hiperinsulinismo , Resistência à Insulina , Síndrome do Ovário Policístico , Feminino , Humanos , Técnica Clamp de Glucose , Insulina , Inflamação/complicações
4.
Acta Neurochir Suppl ; 135: 39-43, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38153447

RESUMO

The management of children affected by neurosurgical pathologies is multidisciplinary and should be set on several fronts.The potential need for massive blood components transfusions, the prolonged anaesthesia in paediatric age that may be often complicated by various forms of syndrome-related problems, and airway management are often encountered.The problems may be divided schematically into three large groups: preoperative, intraoperative and postoperative problems.The aim of this work is to optimize and make paediatric neurosurgery safe by highlighting the most important aspects in the various perioperative phases.


Assuntos
Anestesia , Sacro , Adulto , Humanos , Criança , Cabeça , Base do Crânio/cirurgia , Tecnologia
5.
Acta Neurochir Suppl ; 135: 33-38, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38153446

RESUMO

Spine surgery is an increasingly frequent surgery and includes a wide range of procedures, from minor surgeries (removal of herniated discs, simple laminectomies) to major surgeries (arthrodesis, removal of spinal meningiomas, etc.).These surgeries commonly involve complex patients (elderly population, ASA II-III) and are sometimes performed in emergency settings (polytrauma, cauda syndrome, pathological fractures), which require specific positions (pronation or lateral decubitus), whereby there can be difficulty in airway management, especially in surgeries that concern the cervical tract.One of the main peculiarities of spine surgery involves the prone position.Patient positioning on the operating bed is an action that must be carried out under medical supervision, in particular by the anaesthetist who is supposed to supervise the regular positioning of the patient at the very moment in which it is performed. The correct positioning of the patient is one of the most important moments of the patient care process in the operating room, given that an error in this field may cause serious damage to the patient by giving rise to permanent and significant nerve damage.The prone position is associated with a variety of complications (Kwee et al., Int Surg 100(2): 292-303, 2015). The points of greatest compression during pronation are eyes, nose, breasts, genitals and neck veins.Therefore, the main risks that can derive from an incorrect position are visual disturbances from inappropriate orbital compression, brachial plexus stretching, ulnar nerve compression and lateral femur-cutaneous nerve stretching. In addition, an inappropriate compression of the abdominal organs in this position, may cause ischemia and consequent organ failure resulting in hospitalization prolongation, permanent disability and sometimes even death (Edgcombe et al., Br J Anaesth 100: 165-183, 2008).In addition to the mechanical effects on anatomical structures, there are also the physiological effects of the prone position, which can be divided into circulatory and respiratory effects.These effects are even more pronounced in elderly patients, cardiopaths or patients with respiratory diseases.


Assuntos
Anestesia , Humanos , Idoso , Criança , Tecnologia , Manuseio das Vias Aéreas , Olho , Laminectomia
6.
Acta Neurochir Suppl ; 135: 167-169, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38153466

RESUMO

The introduction of US-guided venipuncture in clinical practice has greatly facilitated the surgical approach to patients with hydrocephalus. Especially in infants and children, where it results in a lower technical failure rate, less time and fewer complications than the traditional referral method, this technique has become a clinical protocol. This dynamic or "real time" technique has become one of the anesthetist's tools. This allowed the anesthesiologists to be part of the surgical team, so they not only dedicate themselves to inducing and maintaining general anesthesia but also to performing venipuncture of the central vein of the neck and to locating the tip of the catheter.The anesthetist's tools have made it possible to perform a simple and safe method, and the anesthesiologists have become an active part of the surgical team, charged with a specific role during the positioning of the ventricular atrial shunt.


Assuntos
Anestesiologistas , Hidrocefalia , Criança , Lactente , Humanos , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/cirurgia , Anestesia Geral , Pescoço , Ultrassonografia
7.
Geophys Res Lett ; 49(23): e2022GL099285, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-37034391

RESUMO

The Juno spacecraft has been in orbit around Jupiter since 2016. Two flybys of Ganymede were executed in 2021, opportunities realized by evolution of Juno's polar orbit over the intervening 5 years. The geometry of the close flyby just prior to the 34th perijove pass by Jupiter brought the spacecraft inside Ganymede's unique magnetosphere. Juno's payload, designed to study Jupiter's magnetosphere, had ample dynamic range to study Ganymede's magnetosphere. The Juno radio system was used both for gravity measurements and for study of Ganymede's ionosphere. Remote sensing of Ganymede returned new results on geology, surface composition, and thermal properties of the surface and subsurface.

8.
Nature ; 536(7614): 54-7, 2016 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-27362221

RESUMO

The typically dark surface of the dwarf planet Ceres is punctuated by areas of much higher albedo, most prominently in the Occator crater. These small bright areas have been tentatively interpreted as containing a large amount of hydrated magnesium sulfate, in contrast to the average surface, which is a mixture of low-albedo materials and magnesium phyllosilicates, ammoniated phyllosilicates and carbonates. Here we report high spatial and spectral resolution near-infrared observations of the bright areas in the Occator crater on Ceres. Spectra of these bright areas are consistent with a large amount of sodium carbonate, constituting the most concentrated known extraterrestrial occurrence of carbonate on kilometre-wide scales in the Solar System. The carbonates are mixed with a dark component and small amounts of phyllosilicates, as well as ammonium carbonate or ammonium chloride. Some of these compounds have also been detected in the plume of Saturn's sixth-largest moon Enceladus. The compounds are endogenous and we propose that they are the solid residue of crystallization of brines and entrained altered solids that reached the surface from below. The heat source may have been transient (triggered by impact heating). Alternatively, internal temperatures may be above the eutectic temperature of subsurface brines, in which case fluids may exist at depth on Ceres today.

9.
Nature ; 529(7586): 368-72, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26760209

RESUMO

Although water vapour is the main species observed in the coma of comet 67P/Churyumov-Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the comets observed so far. The nucleus of 67P/Churyumov-Gerasimenko appears to be fairly uniformly coated with dark, dehydrated, refractory and organic-rich material. Here we report the identification at infrared wavelengths of water ice on two debris falls in the Imhotep region of the nucleus. The ice has been exposed on the walls of elevated structures and at the base of the walls. A quantitative derivation of the abundance of ice in these regions indicates the presence of millimetre-sized pure water-ice grains, considerably larger than in all previous observations. Although micrometre-sized water-ice grains are the usual result of vapour recondensation in ice-free layers, the occurrence of millimetre-sized grains of pure ice as observed in the Imhotep debris falls is best explained by grain growth by vapour diffusion in ice-rich layers, or by sintering. As a consequence of these processes, the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice. The stratigraphy observed on 67P/Churyumov-Gerasimenko is therefore the result of evolutionary processes affecting the uppermost metres of the nucleus and does not necessarily require a global layering to have occurred at the time of the comet's formation.


Assuntos
Meio Ambiente Extraterreno/química , Gelo/análise , Meteoroides , Difusão , Gases/análise , Gases/química , Análise Espectral
10.
Nature ; 525(7570): 500-3, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-26399830

RESUMO

Observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. This was clearly demonstrated on comet 9P/Tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. The observations of 67P/Churyumov-Gerasimenko have revealed that activity has a diurnal variation in intensity arising from changing insolation conditions. It was previously concluded that water vapour was generated in ice-rich subsurface layers with a transport mechanism linked to solar illumination, but that has not hitherto been observed. Periodic condensations of water vapour very close to, or on, the surface were suggested to explain short-lived outbursts seen near sunrise on comet 9P/Tempel 1. Here we report observations of water ice on the surface of comet 67P/Churyumov-Gerasimenko, appearing and disappearing in a cyclic pattern that follows local illumination conditions, providing a source of localized activity. This water cycle appears to be an important process in the evolution of the comet, leading to cyclical modification of the relative abundance of water ice on its surface.


Assuntos
Meio Ambiente Extraterreno/química , Gelo/análise , Meteoroides , Temperatura , Fatores de Tempo , Volatilização
11.
Nature ; 528(7581): 241-4, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26659184

RESUMO

Studies of the dwarf planet (1) Ceres using ground-based and orbiting telescopes have concluded that its closest meteoritic analogues are the volatile-rich CI and CM carbonaceous chondrites. Water in clay minerals, ammoniated phyllosilicates, or a mixture of Mg(OH)2 (brucite), Mg2CO3 and iron-rich serpentine have all been proposed to exist on the surface. In particular, brucite has been suggested from analysis of the mid-infrared spectrum of Ceres. But the lack of spectral data across telluric absorption bands in the wavelength region 2.5 to 2.9 micrometres--where the OH stretching vibration and the H2O bending overtone are found--has precluded definitive identifications. In addition, water vapour around Ceres has recently been reported, possibly originating from localized sources. Here we report spectra of Ceres from 0.4 to 5 micrometres acquired at distances from ~82,000 to 4,300 kilometres from the surface. Our measurements indicate widespread ammoniated phyllosilicates across the surface, but no detectable water ice. Ammonia, accreted either as organic matter or as ice, may have reacted with phyllosilicates on Ceres during differentiation. This suggests that material from the outer Solar System was incorporated into Ceres, either during its formation at great heliocentric distance or by incorporation of material transported into the main asteroid belt.

12.
J Endocrinol Invest ; 44(2): 233-244, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32648001

RESUMO

PCOS is a common and heterogeneous endocrine disorder in women of reproductive age, frequently associated with metabolic abnormalities. It was estimated that about 75% of these subjects have an impairment of insulin action, as measured by gold standard methods. While the relationship between insulin resistance and PCOS is consistently shown by a number of studies, the mechanisms underlying its primary origin still remains an unsolved issue. Insulin resistance and the associated hyperinsulinemia can induce both the endocrine and reproductive traits of PCOS. However, androgen excess, in turn, can impair insulin action, directly and/or through several changes occurring in different tissues. Body fat excess, which is another common feature in these women, can contribute to worsening the whole picture. Nevertheless, insulin resistance may also be found in many normal-weight individuals. Endocrine and metabolic abnormalities can develop in different moments, and probably there is fetal programming of these alterations. However, a number of vicious circles, with bidirectional relationships between androgen excess and insulin resistance, and with the contribution of several other factors, make it extremely difficult to understand where this process really originates. This review summarizes available evidence on this topic, in order to better understand the complex relationships linking hyperandrogenism and impaired insulin action in women with PCOS.


Assuntos
Hiperandrogenismo/patologia , Resistência à Insulina , Síndrome do Ovário Policístico/fisiopatologia , Animais , Feminino , Humanos , Hiperandrogenismo/epidemiologia
13.
Ann Oncol ; 30(Suppl_8): viii5-viii15, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31738427

RESUMO

The tropomyosin receptor kinase (TRK) family of receptor tyrosine kinases are encoded by NTRK genes and have a role in the development and normal functioning of the nervous system. Since the discovery of an oncogenic NTRK gene fusion in colorectal cancer in 1986, over 80 different fusion partner genes have been identified in a wide array of adult and paediatric tumours, providing actionable targets for targeted therapy. This review describes the normal function and physiology of TRK receptors and the biology behind NTRK gene fusions and how they act as oncogenic drivers in cancer. Finally, an overview of the incidence and prevalence of NTRK gene fusions in various types of cancers is discussed.


Assuntos
Neoplasias/genética , Proteínas de Fusão Oncogênica/genética , Receptores Proteína Tirosina Quinases/genética , Receptor trkA/genética , Animais , Fusão Gênica , Humanos , Neoplasias/enzimologia , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptor trkA/metabolismo , Transdução de Sinais
14.
Nature ; 504(7478): 122-5, 2013 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-24196707

RESUMO

Olivine is a major component of the mantle of differentiated bodies, including Earth. Howardite, eucrite and diogenite (HED) meteorites represent regolith, basaltic-crust, lower-crust and possibly ultramafic-mantle samples of asteroid Vesta, which is the lone surviving, large, differentiated, basaltic rocky protoplanet in the Solar System. Only a few of these meteorites, the orthopyroxene-rich diogenites, contain olivine, typically with a concentration of less than 25 per cent by volume. Olivine was tentatively identified on Vesta, on the basis of spectral and colour data, but other observations did not confirm its presence. Here we report that olivine is indeed present locally on Vesta's surface but that, unexpectedly, it has not been found within the deep, south-pole basins, which are thought to be excavated mantle rocks. Instead, it occurs as near-surface materials in the northern hemisphere. Unlike the meteorites, the olivine-rich (more than 50 per cent by volume) material is not associated with diogenite but seems to be mixed with howardite, the most common surface material. Olivine is exposed in crater walls and in ejecta scattered diffusely over a broad area. The size of the olivine exposures and the absence of associated diogenite favour a mantle source, but the exposures are located far from the deep impact basins. The amount and distribution of observed olivine-rich material suggest a complex evolutionary history for Vesta.

15.
Nature ; 491(7422): 83-6, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23128228

RESUMO

Localized dark and bright materials, often with extremely different albedos, were recently found on Vesta's surface. The range of albedos is among the largest observed on Solar System rocky bodies. These dark materials, often associated with craters, appear in ejecta and crater walls, and their pyroxene absorption strengths are correlated with material brightness. It was tentatively suggested that the dark material on Vesta could be either exogenic, from carbon-rich, low-velocity impactors, or endogenic, from freshly exposed mafic material or impact melt, created or exposed by impacts. Here we report Vesta spectra and images and use them to derive and interpret the properties of the 'pure' dark and bright materials. We argue that the dark material is mainly from infall of hydrated carbonaceous material (like that found in a major class of meteorites and some comet surfaces), whereas the bright material is the uncontaminated indigenous Vesta basaltic soil. Dark material from low-albedo impactors is diffused over time through the Vestan regolith by impact mixing, creating broader, diffuse darker regions and finally Vesta's background surface material. This is consistent with howardite-eucrite-diogenite meteorites coming from Vesta.

16.
Ann Oncol ; 28(6): 1302-1308, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28368455

RESUMO

BACKGROUND: Monitoring response and resistance to kinase inhibitors is essential to precision cancer medicine, and is usually investigated by molecular profiling of a tissue biopsy obtained at progression. However, tumor heterogeneity and tissue sampling bias limit the effectiveness of this strategy. In addition, tissue biopsies are not always feasible and are associated with risks due to the invasiveness of the procedure. To overcome these limitations, blood-based liquid biopsy analysis has proven effective to non-invasively follow tumor clonal evolution. PATIENTS AND METHODS: We exploited urine cell-free, trans-renal DNA (tr-DNA) and matched plasma circulating tumor DNA (ctDNA) to monitor a metastatic colorectal cancer patient carrying a CAD-ALK translocation during treatment with an ALK inhibitor. RESULTS: Using a custom next generation sequencing panel we identified the genomic CAD-ALK rearrangement and a TP53 mutation in plasma ctDNA. Sensitive assays were developed to detect both alterations in urine tr-DNA. The dynamics of the CAD-ALK rearrangement in plasma and urine were concordant and paralleled the patient's clinical course. Detection of the CAD-ALK gene fusion in urine tr-DNA anticipated radiological confirmation of disease progression. Analysis of plasma ctDNA identified ALK kinase mutations that emerged during treatment with the ALK inhibitor entrectinib. CONCLUSION: We find that urine-based genetic testing allows tracing of tumor-specific oncogenic rearrangements. This strategy could be effectively applied to non-invasively monitor tumor evolution during therapy. The same approach could be exploited to monitor minimal residual disease after surgery with curative intent in patients whose tumors carry gene fusions. The latter could be implemented without the need of patient hospitalization since urine tr-DNA can be self-collected, is stable over time and can be shipped at specified time-points to central labs for testing.


Assuntos
Aspartato Carbamoiltransferase/genética , Benzamidas/uso terapêutico , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Di-Hidro-Orotase/genética , Rearranjo Gênico , Indazóis/uso terapêutico , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Quinase do Linfoma Anaplásico , Biomarcadores Tumorais , Neoplasias Colorretais/sangue , Neoplasias Colorretais/urina , Resistencia a Medicamentos Antineoplásicos , Feminino , Fusão Gênica , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Receptores Proteína Tirosina Quinases/genética
17.
Geophys Res Lett ; 44(13): 6570-6578, 2017 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-28989206

RESUMO

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

18.
Ann Oncol ; 27(6): 1062-1067, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26916096

RESUMO

BACKGROUND: Objective response to dacarbazine, the intravenous form of temozolomide (TMZ), in metastatic colorectal cancer (mCRC) is confined to tumors harboring O(6)-methylguanine-DNA-methyltransferase (MGMT) promoter hypermethylation. We conducted a phase II study of TMZ enriched by MGMT hypermethylation in archival tumor (AT), exploring dynamic of this biomarker in baseline tumor (BT) biopsy and plasma (liquid biopsy). PATIENTS AND METHODS: We screened 150 mCRC patients for MGMT hypermethylation with methylation-specific PCR on AT from FFPE specimens. Eligible patients (n = 29) underwent BT biopsy and then received TMZ 200 mg/m(2) days 1-5 q28 until progression. A Fleming single-stage design was used to determine whether progression-free survival (PFS) rate at 12 weeks would be ≥35% [H0 ≤ 15%, type I error = 0.059 (one-sided), power = 0.849]. Exploratory analyses included comparison between MGMT hypermethylation in AT and BT, and MGMT methylation testing by MethylBEAMing in solid (AT, BT) and LB with regard to tumor response. RESULTS: The PFS rate at 12 weeks was 10.3% [90% confidence interval (CI) 2.9-24.6]. Objective response rate was 3.4% (90% CI 0.2-15.3), disease control rate 48.3% (90% CI 32.0-64.8), median OS 6.2 months (95% CI 3.8-7.6), and median PFS 2.6 months (95% CI 1.4-2.7). We observed the absence of MGMT hypermethylation in BT in 62.7% of tumors. CONCLUSION: Treatment of mCRC with TMZ driven by MGMT promoter hypermethylation in AT samples did not provide meaningful PFS rate at 12 weeks. This biomarker changed from AT to BT, indicating that testing BT biopsy or plasma is needed for refined target selection.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Metilação de DNA/genética , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Dacarbazina/análogos & derivados , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Biópsia , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Metilases de Modificação do DNA/sangue , Enzimas Reparadoras do DNA/sangue , Dacarbazina/administração & dosagem , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Temozolomida , Proteínas Supressoras de Tumor/sangue
19.
Nature ; 448(7149): 54-6, 2007 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-17611536

RESUMO

Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation. The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bottoms of cup-like craters. Here we report observations of Hyperion's surface in the ultraviolet and near-infrared spectral regions with two optical remote sensing instruments on the Cassini spacecraft at closest approach during a fly-by on 25-26 September 2005. The close fly-by afforded us the opportunity to obtain separate reflectance spectra of the high- and low-albedo surface components. The low-albedo material has spectral similarities and compositional signatures that link it with the surface of Phoebe and a hemisphere-wide superficial coating on Iapetus.

20.
J Nutr Health Aging ; 26(1): 89-95, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35067709

RESUMO

OBJECTIVES: Frailty is a risk factor for poor cognitive performance in older adults. However, few studies have evaluated the association of cognitive performance with frailty in a low- to middle-income country (LMIC). This study aimed to investigate an association between cognitive performance and frailty in older adults with memory complaints in Brazil. Secondarily, we aim to assess an association of cognitive performance with gait speed and grip strength. DESIGN: Cross-sectional study. SETTING: Outpatient service from a LMIC. PARTICIPANTS: Older adults with memory complaints reported by the participants, their proxies, or their physicians. MEASUREMENTS: Frailty was evaluated using the Cardiovascular Health Study criteria. A neuropsychological battery evaluated memory, attention, language, visuospatial function, executive function. Linear regression analysis with adjustment for age, sex, and education was used. We also evaluated the interaction of education with frailty, grip strength, and gait speed. RESULTS: Prefrailty was associated with poor performance in the memory domain, as well as slower gait speed was associated with worse performance in memory, attention, language, and executive function. Frailty and grip strength were not associated with cognitive performance. Interactions of education with gait speed were significant for global performance, as well as for attention and visuospatial ability. CONCLUSION: In elderly patients with memory complaints, prefrailty was associated with poor memory performance. Slowness was associated with poorer performance in some cognitive domains, mainly in participants with low education.


Assuntos
Transtornos Cognitivos , Disfunção Cognitiva , Fragilidade , Idoso , Cognição , Disfunção Cognitiva/psicologia , Estudos Transversais , Função Executiva , Idoso Fragilizado , Fragilidade/complicações , Humanos
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