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1.
Clin Radiol ; 79(5): e675-e681, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38383255

RESUMO

AIM: To predict renal tumour growth patterns in von Hippel-Lindau syndrome by utilising radiomic features to assist in developing personalised surveillance plans leading to better patient outcomes. MATERIALS AND METHODS: The study evaluated 78 renal tumours in 55 patients with histopathologically-confirmed clear cell renal cell carcinomas (ccRCCs), which were segmented and radiomics were extracted. Volumetric doubling time (VDT) classified the tumours into fast-growing (VDT <365 days) or slow-growing (VDT ≥365 days). Volumetric and diametric growth analyses were compared between the groups. Multiple logistic regression and random forest classifiers were used to select the best features and models based on their correlation and predictability of VDT. RESULTS: Fifty-five patients (mean age 42.2 ± 12.2 years, 27 men) with a mean time difference of 3.8 ± 2 years between the baseline and preoperative scans were studied. Twenty-five tumours were fast-growing (low VDT, i.e., <365 days), and 53 tumours were slow-growing (high VDT, i.e., ≥365 days). The median volumetric and diametric growth rates were 1.71 cm3/year and 0.31 cm/year. The best feature using univariate analysis was wavelet-HLL_glcm_ldmn (area under the receiver operating characteristic [ROC] curve [AUC] of 0.80, p<0.0001), and with the random forest classifier, it was log-sigma-0-5-mm-3D_glszm_ZonePercentage (AUC: 79). The AUC of the ROC curves using multiple logistic regression was 0.74, and with the random forest classifier was 0.73. CONCLUSION: Radiomic features correlated with VDT and were able to predict the growth pattern of renal tumours in patients with VHL syndrome.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Doença de von Hippel-Lindau , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Doença de von Hippel-Lindau/complicações , Doença de von Hippel-Lindau/diagnóstico por imagem , Radiômica , Tomografia Computadorizada por Raios X , Neoplasias Renais/complicações , Neoplasias Renais/diagnóstico por imagem , Carcinoma de Células Renais/complicações , Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/patologia
2.
J Pediatr ; 263: 113700, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37640232

RESUMO

OBJECTIVE: To determine the ability of the Bayley-III cognitive and language composite scores at 18-22 months corrected age to predict WISC-IV Full Scale IQ (FSIQ) at 6-7 years in infants born extremely preterm. STUDY DESIGN: Children in this study were part of the Neuroimaging and Neurodevelopmental Outcome cohort, a secondary study to the SUPPORT trial and born 240/7-276/7 weeks gestational age. Bayley-III cognitive and language scores and WISC-IV FSIQ were compared with pairwise Pearson correlation coefficients and adjusted for medical and socioeconomic variables using linear mixed effect regression models. RESULTS: Bayley-III cognitive (r = 0.33) and language scores (r = 0.44) were mildly correlated with WISC-IV FSIQ score. Of the children with Bayley-III cognitive scores of <70, 67% also had FSIQ of <70. There was less consistency for children with Bayley-III scores in the 85-100 range; 43% had an FSIQ of <85 and 10% an FSIQ of <70. Among those with Bayley-III language scores >100, approximately 1 in 5 had an FSIQ of <85. A cut point of 92 for the cognitive composite score resulted in sensitivity (0.60), specificity (0.64). A cut point of 88 for the language composite score produced sensitivity (0.61), specificity (0.70). CONCLUSIONS: Findings indicate the Bayley-III cognitive and language scores correlate with later IQ, but may fail to predict delay or misclassify children who are not delayed at school age. The Bayley-III can be a useful tool to help identify children born extremely preterm who have below average cognitive scores and may be at the greatest risk for ongoing cognitive difficulties. TRIAL REGISTRATION: Extended Follow-up at School Age for the SUPPORT Neuroimaging and Neurodevelopmental Outcomes (NEURO) Cohort: NCT00233324.


Assuntos
Desenvolvimento Infantil , Lactente Extremamente Prematuro , Recém-Nascido , Lactente , Humanos , Criança , Lactente Extremamente Prematuro/psicologia , Idade Gestacional , Cognição , Neuroimagem
3.
Pediatr Res ; 92(4): 1034-1041, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35513716

RESUMO

BACKGROUND: Extremely low birth weight (ELBW) infants are at risk for end-organ hypoxia and ischemia. Regional tissue oxygenation of the brain and gut as monitored with near-infrared spectroscopy (NIRS) may change with postnatal age, but normal ranges are not well defined. METHODS: A prospective study of ELBW preterm infants utilized NIRS monitoring to assess changes in cerebral and mesenteric saturation (Csat and Msat) over the first week after birth. This secondary study of a multicenter trial comparing hemoglobin transfusion thresholds assessed cerebral and mesenteric fractional tissue oxygen extraction (cFTOE and mFTOE) and relationships with perinatal variables. RESULTS: In 124 infants, both Csat and Msat declined over the first week, with a corresponding increase in oxygen extraction. With lower gestational age, lower birth weight, and 5-min Apgar score ≤5, there was a greater increase in oxygen extraction in the brain compared to the gut. Infants managed with a lower hemoglobin transfusion threshold receiving ≥2 transfusions in the first week had the lowest Csat and highest cFTOE (p < 0.001). CONCLUSION: Brain oxygen extraction preferentially increased in more immature and anemic preterm infants. NIRS monitoring may enhance understanding of cerebral and mesenteric oxygenation patterns and inform future protective strategies in the preterm ELBW population. IMPACT: Simultaneous monitoring of cerebral and mesenteric tissue saturation demonstrates the balance of oxygenation between preterm brain and gut and may inform protective strategies. Over the first week, oxygen saturation of the brain and gut declines as oxygen extraction increases. A low hemoglobin transfusion threshold is associated with lower cerebral saturation and higher cerebral oxygen extraction compared to a high hemoglobin transfusion threshold, although this did not translate into clinically relevant differences in the TOP trial primary outcome. Greater oxygen extraction by the brain compared to the gut occurs with lower gestational age, lower birth weight, and 5-min Apgar score ≤5.


Assuntos
Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido Prematuro , Gravidez , Feminino , Recém-Nascido , Humanos , Peso ao Nascer , Estudos Prospectivos , Oxigênio , Encéfalo , Hemoglobinas , Circulação Cerebrovascular
4.
Phys Rev Lett ; 127(8): 082501, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477443

RESUMO

The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a_{1}(1420), decaying to f_{0}(980)π. With a mass too close to and a width smaller than the axial-vector ground state a_{1}(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a_{1}(1260) resonance into K^{*}(→Kπ)K[over ¯] and subsequent rescattering through a triangle singularity into the coupled f_{0}(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

5.
Phys Rev Lett ; 127(24): 241102, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34951783

RESUMO

High-quality optical resonant cavities require low optical loss, typically on the scale of parts per million. However, unintended micron-scale contaminants on the resonator mirrors that absorb the light circulating in the cavity can deform the surface thermoelastically and thus increase losses by scattering light out of the resonant mode. The point absorber effect is a limiting factor in some high-power cavity experiments, for example, the Advanced LIGO gravitational-wave detector. In this Letter, we present a general approach to the point absorber effect from first principles and simulate its contribution to the increased scattering. The achievable circulating power in current and future gravitational-wave detectors is calculated statistically given different point absorber configurations. Our formulation is further confirmed experimentally in comparison with the scattered power in the arm cavity of Advanced LIGO measured by in situ photodiodes. The understanding presented here provides an important tool in the global effort to design future gravitational-wave detectors that support high optical power and thus reduce quantum noise.

6.
J Pediatr ; 226: 36-44.e3, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32739261

RESUMO

OBJECTIVE: To assess outcomes following post-hemorrhagic ventricular dilatation (PHVD) among infants born at ≤26 weeks of gestation. STUDY DESIGN: Observational study of infants born April 1, 2011, to December 31, 2015, in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network and categorized into 3 groups: PHVD, intracranial hemorrhage without ventricular dilatation, or normal head ultrasound. PHVD was treated per center practice. Neurodevelopmental impairment at 18-26 months was defined by cerebral palsy, Bayley Scales of Infant and Toddler Development, 3rd edition, cognitive or motor score <70, blindness, or deafness. Multivariable logistic regression examined the association of death or impairment, adjusting for neonatal course, center, maternal education, and parenchymal hemorrhage. RESULTS: Of 4216 infants, 815 had PHVD, 769 had hemorrhage without ventricular dilatation, and 2632 had normal head ultrasounds. Progressive dilatation occurred among 119 of 815 infants; the initial intervention in 66 infants was reservoir placement and 53 had ventriculoperitoneal shunt placement. Death or impairment occurred among 68%, 39%, and 28% of infants with PHVD, hemorrhage without dilatation, and normal head ultrasound, respectively; aOR (95% CI) were 4.6 (3.8-5.7) PHVD vs normal head ultrasound scan and 2.98 (2.3-3.8) for PHVD vs hemorrhage without dilatation. Death or impairment was more frequent with intervention for progressive dilatation vs no intervention (80% vs 65%; aOR 2.2 [1.38-3.8]). Death or impairment increased with parenchymal hemorrhage, intervention for PHVD, male sex, and surgery for retinopathy; odds decreased with each additional gestational week. CONCLUSIONS: PHVD was associated with high rates of death or impairment among infants with gestational ages ≤26 weeks; risk was further increased among those with progressive ventricular dilation requiring intervention.


Assuntos
Hemorragia Cerebral/complicações , Hemorragia Cerebral/mortalidade , Ventrículos Cerebrais/patologia , Doenças do Prematuro/mortalidade , Doenças do Prematuro/patologia , Transtornos do Neurodesenvolvimento/epidemiologia , Hemorragia Cerebral/terapia , Dilatação Patológica , Feminino , Idade Gestacional , Humanos , Lactente Extremamente Prematuro , Recém-Nascido , Doenças do Prematuro/terapia , Masculino , Derivação Ventriculoperitoneal
7.
Phys Rev Lett ; 123(23): 231107, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31868462

RESUMO

The Laser Interferometer Gravitational Wave Observatory (LIGO) has been directly detecting gravitational waves from compact binary mergers since 2015. We report on the first use of squeezed vacuum states in the direct measurement of gravitational waves with the Advanced LIGO H1 and L1 detectors. This achievement is the culmination of decades of research to implement squeezed states in gravitational-wave detectors. During the ongoing O3 observation run, squeezed states are improving the sensitivity of the LIGO interferometers to signals above 50 Hz by up to 3 dB, thereby increasing the expected detection rate by 40% (H1) and 50% (L1).

8.
N Engl J Med ; 372(4): 331-40, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25607427

RESUMO

BACKGROUND: Understanding the causes and timing of death in extremely premature infants may guide research efforts and inform the counseling of families. METHODS: We analyzed prospectively collected data on 6075 deaths among 22,248 live births, with gestational ages of 22 0/7 to 28 6/7 weeks, among infants born in study hospitals within the National Institute of Child Health and Human Development Neonatal Research Network. We compared overall and cause-specific in-hospital mortality across three periods from 2000 through 2011, with adjustment for baseline differences. RESULTS: The number of deaths per 1000 live births was 275 (95% confidence interval [CI], 264 to 285) from 2000 through 2003 and 285 (95% CI, 275 to 295) from 2004 through 2007; the number decreased to 258 (95% CI, 248 to 268) in the 2008-2011 period (P=0.003 for the comparison across three periods). There were fewer pulmonary-related deaths attributed to the respiratory distress syndrome and bronchopulmonary dysplasia in 2008-2011 than in 2000-2003 and 2004-2007 (68 [95% CI, 63 to 74] vs. 83 [95% CI, 77 to 90] and 84 [95% CI, 78 to 90] per 1000 live births, respectively; P=0.002). Similarly, in 2008-2011, as compared with 2000-2003, there were decreases in deaths attributed to immaturity (P=0.05) and deaths complicated by infection (P=0.04) or central nervous system injury (P<0.001); however, there were increases in deaths attributed to necrotizing enterocolitis (30 [95% CI, 27 to 34] vs. 23 [95% CI, 20 to 27], P=0.03). Overall, 40.4% of deaths occurred within 12 hours after birth, and 17.3% occurred after 28 days. CONCLUSIONS: We found that from 2000 through 2011, overall mortality declined among extremely premature infants. Deaths related to pulmonary causes, immaturity, infection, and central nervous system injury decreased, while necrotizing enterocolitis-related deaths increased. (Funded by the National Institutes of Health.).


Assuntos
Mortalidade Infantil/tendências , Lactente Extremamente Prematuro , Doenças do Prematuro/mortalidade , Causas de Morte , Anormalidades Congênitas/mortalidade , Enterocolite Necrosante/mortalidade , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Fatores de Risco , Estados Unidos/epidemiologia
9.
Am J Obstet Gynecol ; 218(1): 130.e1-130.e13, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29138031

RESUMO

BACKGROUND: Antenatal corticosteroids are given primarily to induce fetal lung maturation but results from meta-analyses of randomized controlled trials have not shown mortality or pulmonary benefits for extremely preterm infants although these are the infants most at risk of mortality and pulmonary disease. OBJECTIVE: We sought to determine if exposure to antenatal corticosteroids is associated with a lower rate of death and pulmonary morbidities by 36 weeks' postmenstrual age. STUDY DESIGN: Prospectively collected data on 11,022 infants 22 0/7 to 28 6/7 weeks' gestational age with a birthweight of ≥401 g born from Jan. 1, 2006, through Dec. 31, 2014, were analyzed. The rate of death and the rate of physiologic bronchopulmonary dysplasia by 36 weeks' postmenstrual age were analyzed by level of exposure to antenatal corticosteroids using models adjusted for maternal variables, infant variables, center, and epoch. RESULTS: Infants exposed to any antenatal corticosteroids had a lower rate of death (2193/9670 [22.7%]) compared to infants without exposure (540/1302 [41.5%]) (adjusted relative risk, 0.71; 95% confidence interval, 0.65-0.76; P < .0001). Infants exposed to a partial course of antenatal corticosteroids also had a lower rate of death (654/2520 [26.0%]) compared to infants without exposure (540/1302 [41.5%]); (adjusted relative risk, 0.77; 95% confidence interval, 0.70-0.85; P < .0001). In an analysis by each week of gestation, infants exposed to a complete course of antenatal corticosteroids had lower mortality before discharge compared to infants without exposure at each week from 23-27 weeks' gestation and infants exposed to a partial course of antenatal corticosteroids had lower mortality at 23, 24, and 26 weeks' gestation. Rates of bronchopulmonary dysplasia in survivors did not differ by antenatal corticosteroid exposure. The rate of death due to respiratory distress syndrome, the rate of surfactant use, and the rate of mechanical ventilation were lower in infants exposed to any antenatal corticosteroids compared to infants without exposure. CONCLUSION: Among infants 22-28 weeks' gestational age, any or partial antenatal exposure to corticosteroids compared to no exposure is associated with a lower rate of death while the rate of bronchopulmonary dysplasia in survivors did not differ.


Assuntos
Glucocorticoides/uso terapêutico , Lactente Extremamente Prematuro , Efeitos Tardios da Exposição Pré-Natal , Displasia Broncopulmonar/epidemiologia , Uso de Medicamentos , Feminino , Idade Gestacional , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido , Masculino , Gravidez , Estudos Prospectivos , Surfactantes Pulmonares/uso terapêutico , Respiração Artificial/estatística & dados numéricos , Síndrome do Desconforto Respiratório do Recém-Nascido/mortalidade , Estados Unidos/epidemiologia
11.
Phys Rev Lett ; 119(11): 112002, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28949229

RESUMO

The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/c π^{-} beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/c^{2} and 8.5 GeV/c^{2}. Within the experimental uncertainties, the observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of quantum chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was obtained at a hard scale comparable to that of these DY results. This opens the way for possible tests of fundamental QCD universality predictions.

12.
Eur J Clin Microbiol Infect Dis ; 36(3): 467-478, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27816993

RESUMO

FimH-mediated adhesion of Escherichia coli to bladder epithelium is a prerequisite for urinary tract infections. FimH is also essential for blood-borne bacterial dissemination, but the mechanisms are poorly understood. The purpose of this study was to assess the influence of different FimH mutations on bacterial adhesion using a novel adhesion assay, which models the physiological flow conditions bacteria are exposed to. We introduced 12 different point mutations in the mannose binding pocket of FimH in an E. coli strain expressing type 1 fimbriae only (MSC95-FimH). We compared the bacterial adhesion of each mutant across several commonly used adhesion assays, including agglutination of yeast, adhesion to mono- and tri-mannosylated substrates, and static adhesion to bladder epithelial and endothelial cells. We performed a comparison of these assays to a novel method that we developed to study bacterial adhesion to mammalian cells under flow conditions. We showed that E. coli MSC95-FimH adheres more efficiently to microvascular endothelium than to bladder epithelium, and that only endothelium supports adhesion at physiological shear stress. The results confirmed that mannose binding pocket mutations abrogated adhesion. We demonstrated that FimH residues E50 and T53 are crucial for adhesion under flow conditions. The coating of endothelial cells on biochips and modelling of physiological flow conditions enabled us to identify FimH residues crucial for adhesion. These results provide novel insights into screening methods to determine the effect of FimH mutants and potentially FimH antagonists.


Assuntos
Adesinas de Escherichia coli/genética , Aderência Bacteriana , Escherichia coli/genética , Escherichia coli/fisiologia , Proteínas de Fímbrias/genética , Mutação Puntual , Sítios de Ligação , Células Cultivadas , Células Endoteliais/microbiologia , Células Epiteliais/microbiologia , Humanos , Lectina de Ligação a Manose/genética
13.
Br Poult Sci ; 58(6): 729-738, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28805076

RESUMO

1. The objective of this study was to investigate differences in growth performance, serum intermediary metabolites, acute-phase proteins and white blood cells in low, medium and high-residual feed intake (RFI) chickens. It was also assessed if the environment affects the feed efficiency (FE) and FE-related performance and serum profiles of chickens. 2. Individual body weight (BW) and feed intake (FI) were recorded from d 7 of life. At 5 weeks of age, female and male broiler chickens (Cobb 500) were selected according to their RFI (L1: Austria; L2: UK; n = 9/RFI group, sex and locatity -45on) and blood samples were collected. 3. Chickens at L1 had similar FI but a 15% higher BW gain compared to chickens at L2. The RFI values of female chickens were -231, 8 and 215 g and those of male chickens -197, 0 and 267 g for low, medium and high RFI, respectively. 4. Location affected serum glucose, urea, cholesterol, non-esterified fatty acids (NEFA) and ovotransferrin in females, and serum glucose and triglycerides in male chickens. Serum uric acid and NEFA linearly increased from low to high RFI in females, whereas in males, cholesterol showed the same linear response from low to high RFI. Serum alpha-1-acid glycoprotein and blood heterophil-to-lymphocyte ratio linearly increased by 35% and 68%, respectively, from low to high RFI but only in male chickens at L1. 5. Regression analysis showed significant positive relationships between RFI and serum uric acid (R2 = 0.49) and cholesterol (R2 = 0.13). 6. It was concluded that RFI-related variation in serum metabolites of chickens was largely similar for the two environments and that serum metabolite patterns could be used to predict RFI in chickens.


Assuntos
Proteínas de Fase Aguda/metabolismo , Ração Animal/análise , Galinhas/fisiologia , Metabolismo Energético , Leucócitos/metabolismo , Animais , Galinhas/sangue , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Feminino , Masculino , Distribuição Aleatória , Aumento de Peso
14.
Pediatr Res ; 80(2): 209-17, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27074126

RESUMO

BACKGROUND: Preterm infants with respiratory distress syndrome (RDS) given inositol had reduced bronchopulmonary dysplasia (BPD), death and severe retinopathy of prematurity (ROP). We assessed the safety and pharmacokinetics of daily inositol to select a dose providing serum levels previously associated with benefit, and to learn if accumulation occurred when administered throughout the normal period of retinal vascularization. METHODS: Infants ≤ 29 wk GA (n = 122, 14 centers) were randomized and treated with placebo or inositol at 10, 40, or 80 mg/kg/d. Intravenous administration converted to enteral when feedings were established, and continued to the first of 10 wk, 34 wk postmenstrual age (PMA) or discharge. Serum collection employed a sparse sampling population pharmacokinetics design. Inositol urine losses and feeding intakes were measured. Safety was prospectively monitored. RESULTS: At 80 mg/kg/d mean serum levels reached 140 mg/l, similar to Hallman's findings. Levels declined after 2 wk, converging in all groups by 6 wk. Analyses showed a mean volume of distribution 0.657 l/kg, clearance 0.058 l/kg/h, and half-life 7.90 h. Adverse events and comorbidities were fewer in the inositol groups, but not significantly so. CONCLUSION: Multiple dose inositol at 80 mg/kg/d was not associated with increased adverse events, achieves previously effective serum levels, and is appropriate for investigation in a phase III trial.


Assuntos
Inositol/farmacocinética , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Displasia Broncopulmonar/complicações , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Infusões Intravenosas , Inositol/administração & dosagem , Masculino , Segurança do Paciente , Síndrome do Desconforto Respiratório do Recém-Nascido/complicações , Retinopatia da Prematuridade/complicações , Fatores de Tempo
15.
J Evol Biol ; 28(2): 267-91, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25625702

RESUMO

Links between parasites and food webs are evolutionarily ancient but dynamic: life history theory provides insights into helminth complex life cycle origins. Most adult helminths benefit by sexual reproduction in vertebrates, often high up food chains, but direct infection is commonly constrained by a trophic vacuum between free-living propagules and definitive hosts. Intermediate hosts fill this vacuum, facilitating transmission to definitive hosts. The central question concerns why sexual reproduction, and sometimes even larval growth, is suppressed in intermediate hosts, favouring growth arrest at larval maturity in intermediate hosts and reproductive suppression until transmission to definitive hosts? Increased longevity and higher growth in definitive hosts can generate selection for larger parasite body size and higher fecundity at sexual maturity. Life cycle length is increased by two evolutionary mechanisms, upward and downward incorporation, allowing simple (one-host) cycles to become complex (multihost). In downward incorporation, an intermediate host is added below the definitive host: models suggest that downward incorporation probably evolves only after ecological or evolutionary perturbations create a trophic vacuum. In upward incorporation, a new definitive host is added above the original definitive host, which subsequently becomes an intermediate host, again maintained by the trophic vacuum: theory suggests that this is plausible even under constant ecological/evolutionary conditions. The final cycle is similar irrespective of its origin (upward or downward). Insights about host incorporation are best gained by linking comparative phylogenetic analyses (describing evolutionary history) with evolutionary models (examining selective forces). Ascent of host trophic levels and evolution of optimal host taxa ranges are discussed.


Assuntos
Evolução Biológica , Cadeia Alimentar , Helmintíase Animal , Helmintos/genética , Estágios do Ciclo de Vida/genética , Animais , Helmintos/fisiologia , Estágios do Ciclo de Vida/fisiologia
16.
J Evol Biol ; 28(2): 292-304, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25645609

RESUMO

We review how trophically transmitted helminths adapt to the special problems associated with successive hosts in complex cycles. In intermediate hosts, larvae typically show growth arrest at larval maturity (GALM). Theoretical models indicate that optimization of size at GALM requires larval mortality rate to increase with time between infection and GALM: low larval growth or paratenicity (no growth) arises from unfavourable growth and mortality rates in the intermediate host and low transmission rates to the definitive host. Reverse conditions favour high GALM size or continuous growth. Some support is found for these predictions. Intermediate host manipulation involves predation suppression (which decreases host vulnerability before the larva can establish in its next host) and predation enhancement (which increases host vulnerability after the larva can establish in its next host). Switches between suppression and enhancement suggest adaptive manipulation. Manipulation conflicts can occur between larvae of different ages/species a host individual. Larvae must usually develop to GALM before becoming infective to the next host, possibly due to trade-offs, e.g. between growth/survival in the present host and infection ability for the next host. In definitive hosts, if mortality rate is constant, optimal growth before switching to reproduction is set by the growth/morality rate ratio. Rarely, no growth occurs in definitive hosts, predicted (with empirical support) when larval size on infection exceeds growth/mortality rate. Tissue migration patterns and residence sites may be explained by variations in growth/mortality rates between host gut and soma, migration costs and benefits of releasing eggs in the gut.


Assuntos
Adaptação Fisiológica/fisiologia , Evolução Biológica , Cadeia Alimentar , Helmintíase Animal , Helmintos/genética , Estágios do Ciclo de Vida/genética , Adaptação Fisiológica/genética , Animais , Helmintos/fisiologia , Estágios do Ciclo de Vida/fisiologia
17.
Am J Obstet Gynecol ; 212(1): 94.e1-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25046806

RESUMO

OBJECTIVE: Antenatal magnesium (anteMg) is used for various obstetric indications including fetal neuroprotection. Infants exposed to anteMg may be at risk for respiratory depression and delivery room (DR) resuscitation. The study objective was to compare the risk of acute cardiorespiratory events among preterm infants who were and were not exposed to anteMg. STUDY DESIGN: This was a retrospective analysis of prospective data collected in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's Generic Database from April 1, 2011, through March 31, 2012. The primary outcome was DR intubation or respiratory support at birth or on day 1 of life. Secondary outcomes were invasive mechanical ventilation, hypotension treatment, neonatal morbidities, and mortality. Logistic regression analysis evaluated the risk of primary outcome after adjustment for covariates. RESULTS: We evaluated 1544 infants <29 weeks' gestational age (1091 in anteMg group and 453 in nonexposed group). Mothers in the anteMg group were more likely to have higher education, pregnancy-induced hypertension, and antenatal corticosteroids, while their infants were younger in gestation and weighed less (P < .05). The primary outcome (odds ratio [OR], 1.2; 95% confidence interval [CI], 0.88-1.65) was similar between groups. Hypotension treatment (OR, 0.70; 95% CI, 0.51-0.97) and invasive mechanical ventilation (OR, 0.54; 95% CI, 0.41-0.72) were significantly less in the anteMg group. CONCLUSION: Among preterm infants age <29 weeks' gestation, anteMg exposure was not associated with an increase in cardiorespiratory events in the early newborn period. The safety of anteMg as measured by the need for DR intubation or respiratory support on day 1 of life was comparable between groups.


Assuntos
Cardiopatias/induzido quimicamente , Doenças do Prematuro/induzido quimicamente , Sulfato de Magnésio/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Transtornos Respiratórios/induzido quimicamente , Doença Aguda , Adulto , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Gravidez , Estudos Retrospectivos , Adulto Jovem
18.
JAMA ; 314(10): 1039-51, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26348753

RESUMO

IMPORTANCE: Extremely preterm infants contribute disproportionately to neonatal morbidity and mortality. OBJECTIVE: To review 20-year trends in maternal/neonatal care, complications, and mortality among extremely preterm infants born at Neonatal Research Network centers. DESIGN, SETTING, PARTICIPANTS: Prospective registry of 34,636 infants, 22 to 28 weeks' gestation, birth weight of 401 to 1500 g, and born at 26 network centers between 1993 and 2012. EXPOSURES: Extremely preterm birth. MAIN OUTCOMES AND MEASURES: Maternal/neonatal care, morbidities, and survival. Major morbidities, reported for infants who survived more than 12 hours, were severe necrotizing enterocolitis, infection, bronchopulmonary dysplasia, severe intracranial hemorrhage, cystic periventricular leukomalacia, and/or severe retinopathy of prematurity. Regression models assessed yearly changes and were adjusted for study center, race/ethnicity, gestational age, birth weight for gestational age, and sex. RESULTS: Use of antenatal corticosteroids increased from 1993 to 2012 (24% [348 of 1431 infants]) to 87% (1674 of 1919 infants]; P < .001), as did cesarean delivery (44% [625 of 1431 births] to 64% [1227 of 1921]; P < .001). Delivery room intubation decreased from 80% (1144 of 1433 infants) in 1993 to 65% (1253 of 1922) in 2012 (P < .001). After increasing in the 1990s, postnatal steroid use declined to 8% (141 of 1757 infants) in 2004 (P < .001), with no significant change thereafter. Although most infants were ventilated, continuous positive airway pressure without ventilation increased from 7% (120 of 1666 infants) in 2002 to 11% (190 of 1756 infants) in 2012 (P < .001). Despite no improvement from 1993 to 2004, rates of late-onset sepsis declined between 2005 and 2012 for infants of each gestational age (median, 26 weeks [37% {109 of 296} to 27% {85 of 320}]; adjusted relative risk [RR], 0.93 [95% CI, 0.92-0.94]). Rates of other morbidities declined, but bronchopulmonary dysplasia increased between 2009 and 2012 for infants at 26 to 27 weeks' gestation (26 weeks, 50% [130 of 258] to 55% [164 of 297]; P < .001). Survival increased between 2009 and 2012 for infants at 23 weeks' gestation (27% [41 of 152] to 33% [50 of 150]; adjusted RR, 1.09 [95% CI, 1.05-1.14]) and 24 weeks (63% [156 of 248] to 65% [174 of 269]; adjusted RR, 1.05 [95% CI, 1.03-1.07]), with smaller relative increases for infants at 25 and 27 weeks' gestation, and no change for infants at 22, 26, and 28 weeks' gestation. Survival without major morbidity increased approximately 2% per year for infants at 25 to 28 weeks' gestation, with no change for infants at 22 to 24 weeks' gestation. CONCLUSIONS AND RELEVANCE: Among extremely preterm infants born at US academic centers over the last 20 years, changes in maternal and infant care practices and modest reductions in several morbidities were observed, although bronchopulmonary dysplasia increased. Survival increased most markedly for infants born at 23 and 24 weeks' gestation and survival without major morbidity increased for infants aged 25 to 28 weeks. These findings may be valuable in counseling families and developing novel interventions. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00063063.


Assuntos
Corticosteroides/uso terapêutico , Lactente Extremamente Prematuro , Doenças do Prematuro/epidemiologia , Adulto , Displasia Broncopulmonar/epidemiologia , Cesárea/estatística & dados numéricos , Cesárea/tendências , Pressão Positiva Contínua nas Vias Aéreas/estatística & dados numéricos , Pressão Positiva Contínua nas Vias Aéreas/tendências , Enterocolite Necrosante/epidemiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/mortalidade , Doenças do Prematuro/terapia , Infecções/epidemiologia , Terapia Intensiva Neonatal/estatística & dados numéricos , Hemorragias Intracranianas/epidemiologia , Leucomalácia Periventricular/epidemiologia , Masculino , Gravidez , Retinopatia da Prematuridade/epidemiologia , Análise de Sobrevida , Estados Unidos/epidemiologia
19.
Poult Sci ; 93(11): 2718-23, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25260527

RESUMO

Microbial phytases increase the bioavailability of phytate P in poultry diets, and a survey was undertaken to determine if their use had lowered the P composition of broiler litter in Northern Ireland compared with standard values of litter composition listed in the current United Kingdom fertilizer recommendations. Litter samples were collected from a total of 20 units across Northern Ireland in 2010 and analyzed for DM, N, phosphate (P2O5), potash (K2O), magnesium oxide (MgO), water-soluble P (WSP), ammonium N (NH4N), and uric acid N. Dry matter of litter was positively correlated (P < 0.001) with N (r(2) = 0.65), P2O5 (r(2) = 0.63), K2O (r(2) = 0.56), and MgO (r(2) = 0.58). Negative correlations were observed between litter DM and WSP (r(2) = 0.45, P < 0.001) and NH4N (r(2) = 0.22, P = 0.038) contents. A standardized litter composition with a 60% DM gave a phosphate content of 13.7 kg/t that was 45% lower than the fertilizer book value (RB209), but there were only slight differences (<3%) between book values and DM standardized values for N and potash contents. Uric acid and NH4 contents were similar to published values. Mean N:P ratio (by weight) of litter increased from 3.7 in 2004 to 5.0 in 2010, lowering the risk of oversupply of P if land applications are targeted to meet N supply. Using the standard RB209 values to plan land applications of broiler litter to meet crop P demands risks undersupplying P, and there is a need for the regulatory values to be modified in light of the changing composition of broiler litter.


Assuntos
6-Fitase/metabolismo , Galinhas/metabolismo , Esterco/análise , Fósforo/análise , Ração Animal/análise , Animais , Dieta/veterinária , Irlanda do Norte
20.
Issues Ment Health Nurs ; 35(3): 198-207, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24597585

RESUMO

There are no established screening criteria to help identify mothers of premature infants who are at risk for symptoms of emotional distress. The current study, using data obtained from recruitment and screening in preparation for a randomized controlled trial, aimed to identify potential risk factors associated with symptoms of depression, anxiety and posttraumatic stress in a sample of mothers with premature infants hospitalized in a neonatal intensive care unit. One hundred, thirty-five mothers of preterm infants born at 26-34 weeks of gestation completed three self-report measures: the Stanford Acute Stress Reaction Questionnaire, the Beck Depression Inventory (2nd ed.), and the Beck Anxiety Inventory to determine their eligibility for inclusion in a treatment intervention study based on clinical cut-off scores for each measure. Maternal sociodemographic measures, including race, ethnicity, age, maternal pregnancy history, and measures of infant medical severity were not helpful in differentiating mothers who screened positive on one or more of the measures from those who screened negative. Programs to screen parents of premature infants for the presence of symptoms of posttraumatic stress, anxiety, and depression will need to adopt universal screening rather than profiling of potential high risk parents based on their sociodemographic characteristics or measures of their infant's medical severity.


Assuntos
Doenças do Prematuro/enfermagem , Doenças do Prematuro/psicologia , Unidades de Terapia Intensiva Neonatal , Programas de Rastreamento/enfermagem , Trabalho de Parto Prematuro/enfermagem , Trabalho de Parto Prematuro/psicologia , Transtornos Puerperais/diagnóstico , Transtornos Puerperais/enfermagem , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/enfermagem , Adulto , Transtornos de Ansiedade/diagnóstico , Transtornos de Ansiedade/enfermagem , Transtornos de Ansiedade/psicologia , California , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/enfermagem , Depressão Pós-Parto/psicologia , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Psicometria/estatística & dados numéricos , Transtornos Puerperais/psicologia , Reprodutibilidade dos Testes , Transtornos de Estresse Pós-Traumáticos/psicologia , Inquéritos e Questionários
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