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1.
Nature ; 554(7691): 207-210, 2018 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-29261643

RESUMO

GW170817 was the first gravitational-wave detection of a binary neutron-star merger. It was accompanied by radiation across the electromagnetic spectrum and localized to the galaxy NGC 4993 at a distance of 40 megaparsecs. It has been proposed that the observed γ-ray, X-ray and radio emission is due to an ultra-relativistic jet being launched during the merger (and successfully breaking out of the surrounding material), directed away from our line of sight (off-axis). The presence of such a jet is predicted from models that posit neutron-star mergers as the drivers of short hard-γ-ray bursts. Here we report that the radio light curve of GW170817 has no direct signature of the afterglow of an off-axis jet. Although we cannot completely rule out the existence of a jet directed away from the line of sight, the observed γ-ray emission could not have originated from such a jet. Instead, the radio data require the existence of a mildly relativistic wide-angle outflow moving towards us. This outflow could be the high-velocity tail of the neutron-rich material that was ejected dynamically during the merger, or a cocoon of material that breaks out when a jet launched during the merger transfers its energy to the dynamical ejecta. Because the cocoon model explains the radio light curve of GW170817, as well as the γ-ray and X-ray emission (and possibly also the ultraviolet and optical emission), it is the model that is most consistent with the observational data. Cocoons may be a ubiquitous phenomenon produced in neutron-star mergers, giving rise to a hitherto unidentified population of radio, ultraviolet, X-ray and γ-ray transients in the local Universe.

2.
J Dairy Sci ; 107(2): 1022-1034, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37730178

RESUMO

Genetic selection could be a tool to help improve the health and welfare of calves; however, to date, there is limited research on the genetics of calfhood diseases. This study aimed to understand the current impact of calf diseases, by investigating incidence rates, estimating genetic parameters, and providing industry recommendations to improve calf disease recording practices on farms. Available calf disease data composed of 69,695 Holstein calf disease records for respiratory problems (RESP) and diarrhea (DIAR), from 62,361 calves collected on 1,617 Canadian dairy herds from 2006 to 2021. Single- and multiple-trait analysis using both a threshold and linear animal model for each trait were evaluated. Furthermore, each trait was analyzed using 2 scenarios with respect to minimum disease incidence threshold criterion (herd-year incidence of at least 1% and 5%) to highlight the effect of different filtering thresholds on selection potential. Observed scale heritability estimates for RESP and DIAR ranged from 0.02 to 0.07 across analyses, while estimated genetic correlations between the traits ranged from 0.50 to 0.62. Sires were compared based on their estimated breeding value and their diseased daughter incidence rates. On average, calves born to the bottom 10% of sires were 1.8 times more likely to develop RESP and 1.9 times to develop DIAR compared with daughters born to the top 10% of sires. Results from the current study are promising for the inclusion of both DIAR and RESP in Canadian genetic evaluations. However, for effective genetic evaluation, standardized approaches on data collection and industry outreach to highlight the importance of collecting and uploading this information to herd management software is required. In particular, it is important that the herd management software is accessible to the national milk recording system to allow for use in national genetic evaluation.


Assuntos
Doenças dos Bovinos , Leite , Animais , Bovinos/genética , Canadá , Fenótipo , Doenças dos Bovinos/genética , Doenças dos Bovinos/epidemiologia , Diarreia/veterinária , Seleção Genética , Indústria de Laticínios/métodos
3.
J Dairy Sci ; 105(10): 8177-8188, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36055841

RESUMO

Dairy farmers are motivated to ensure cows become pregnant in an optimal and timely manner. Although timed artificial insemination (TAI) is a successful management tool in dairy cattle, it masks an animal's innate fertility performance, likely reducing the accuracy of genetic evaluations for fertility traits. Therefore, separating fertility traits based on the recorded management technique involved in the breeding process or adding the breeding protocol as an effect to the model can be viable approaches to address the potential bias caused by such management decisions. Nevertheless, there is a lack of specificity and uniformity in the recording of breeding protocol descriptions by dairy farmers. Therefore, this study investigated the use of 8 supervised machine learning algorithms to classify 1,835 unique breeding protocol descriptions from 981 herds into the following 2 classes: TAI or other than TAI. Our results showed that models that used a stacking classifier algorithm had the highest Matthews correlation coefficient (0.94 ± 0.04, mean ± SD) and maximized precision and recall (F1-score = 0.96 ± 0.03) on test data. Nonetheless, their F1-scores on test data were not different from 5 out of the other 7 algorithms considered. Altogether, results presented herein suggest machine learning algorithms can be used to produce robust models that correctly identify TAI protocols from dairy cattle breeding records, thus opening the opportunity for unbiased genetic evaluation of animals based on their natural fertility.


Assuntos
Fertilidade , Inseminação Artificial , Algoritmos , Animais , Canadá , Bovinos , Sincronização do Estro/métodos , Feminino , Hormônio Liberador de Gonadotropina , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Lactação , Aprendizado de Máquina , Gravidez , Progesterona
4.
J Dairy Sci ; 104(11): 11820-11831, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34454750

RESUMO

Estrus detection has become more difficult over the years due to decreases in the estrus expression of high-producing dairy cows, and increased herd sizes and animal density. Through the use of hormonal synchronization protocols, also known as timed artificial insemination (TAI) protocols, it is possible to alleviate some of the challenges associated with estrus detection. However, TAI masks cows' fertility performance, resulting in an unfair comparison of treated animals and innately fertile animals. Consequently, genetically inferior and superior cows show similar phenotypes, making it difficult to distinguish between them. As genetic programs rely on the collection of accurate phenotypic data, phenotypes collected on treated animals likely add bias to genetic evaluations. In this study, to assess the effect of TAI, the rank correlation of bulls for a given trait using only TAI records were compared with the same trait using only heat detection records. A total of 270,434 records from 192,539 animals split across heifers, first and second parity cows were analyzed for the traits: calving to first service, first service to conception, and days open. Results showed large reranking across all traits and parities between bulls compared based on either having only TAI records or only heat detection records, suggesting that a bias does indeed exist. Large reranking was also observed for both the heat detection and TAI groups among the top 100 bulls in the control group, which included all records. Furthermore, breeding method was added to the model to assess its effect on bull ranking. However, there were only minor changes in the rank correlations between scenario groups. Therefore, more complex methods to account for the apparent bias created by TAI should be investigated; for this, the method by which these data are collected needs to be improved through creating a standardized way of recording breeding codes. Though the results of this study suggest the presence of bias within current fertility evaluations, additional research is required to confirm the findings of this study, including looking at high-reliability bulls specifically, to determine if the levels of reranking remain. Future studies should also aim to understand the potential genetic differences between the fertility traits split via management technology, possibly in a multiple-trait analysis.


Assuntos
Fertilidade , Inseminação Artificial , Animais , Bovinos/genética , Detecção do Estro , Sincronização do Estro , Feminino , Fertilidade/genética , Inseminação Artificial/veterinária , Lactação , Masculino , Fenótipo , Gravidez , Reprodutibilidade dos Testes
5.
J Dairy Sci ; 104(8): 9002-9015, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33934872

RESUMO

Genetic improvement is a crucial tool to deal with the increasing demand for high quality, sustainably produced dairy. Breeding programs are based on genetic parameters, such as heritability and genetic correlations, for economically important traits in a population. In this study, we estimated population genetic parameters and genetic trends for 67 traits evaluated on heifers and first-lactation Canadian Holstein cows. The data consisted of approximately 500,000 records with pedigree information collected from 1980 to 2019. Genetic parameters were estimated using bivariate linear animal models under a Bayesian approach. Analyses for the 67 traits resulted in 2,211 bivariate combinations, from which the estimated genetic parameters are reported here. The most highly heritable traits were fat percent (0.66) and protein percent (0.69), followed by stature (0.47). Lowest heritabilities (0.01) were observed for disease-related traits, such as lameness and toe ulcer, and calf survival. The genetic correlations between gestation length, calf size, and calving ease measured on both heifer and cows were close to unity. On the other hand, traits such as body condition score and pin width, cystic ovaries and sole ulcer, rear teat placement, and toe ulcer were genetically unrelated. This study reports genetic parameters that have not been previously published for Canadian Holstein cows, and provides updates of those previously estimated. These estimates are useful for building new indexes, updating existing selection indexes, and for predicting correlated responses due to inclusion of novel traits in the breeding programs.


Assuntos
Lactação , Leite , Animais , Teorema de Bayes , Canadá , Bovinos/genética , Feminino , Lactação/genética , Fenótipo
6.
Colorectal Dis ; 22(10): 1422-1428, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32198787

RESUMO

AIM: Robotic transanal minimally invasive surgery (R-TAMIS) is gaining traction around the globe as an alternative to laparoscopic conventional TAMIS for local excision of benign and early malignant rectal lesions. The aim was to analyse patient and oncological outcomes of R-TAMIS for consecutive cases in a single centre. METHODS: A prospective analysis of consecutive R-TAMIS procedures over a 12-month period was performed. Data were collated from hospital databases and theatre registers. RESULTS: Eleven patients (six men, five women), mean age 69.81 years (51-92 years), underwent R-TAMIS over 12 months utilizing a da Vinci Xi platform. The mean lesion size was 36 mm (20-60 mm) with a mean distance from the anal verge of 7.5 cm (3-14 cm). Five lesions were posterior in anatomical location, four anterior, one right lateral and one left lateral. All procedures were performed in the lithotomy position using a GelPOINT Path Platform. Mean operative time was 64 min (40-100 min). Complete resection was achieved in 10/11 patients with two patients being upgraded to a diagnosis of adenocarcinoma. Nine patients were diagnosed with dysplastic lesions. Four patients had a false positive diagnosis of an invasive tumour on MRI. Six patients required suturing for full-thickness resections. One patient had a postoperative bleed requiring repeat endoscopy and clipping. One patient (full-thickness resection of T3 tumour) proceeded to a formal resection without difficulty with no residual disease (T0N0, 0/22). One patient with a fully resected T2 tumour is undergoing a surveillance protocol. The mean length of stay was 1 day with two patients having a length of stay of 2 days and one patient of 4 days. CONCLUSION: R-TAMIS could potentially represent a safe novel approach for local resection of rectal lesions.


Assuntos
Neoplasias Retais , Procedimentos Cirúrgicos Robóticos , Cirurgia Endoscópica Transanal , Idoso , Canal Anal/cirurgia , Feminino , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos , Neoplasias Retais/cirurgia , Reto , Resultado do Tratamento
7.
Br Poult Sci ; 61(5): 550-556, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32329627

RESUMO

1. Campylobacteriosis is the leading cause of human bacterial gastroenteritis. Broilers are considered the most important source of human Campylobacter infection. In the 2008 European baseline survey Ireland had a 98% prevalence of campylobacter-contaminated broiler carcases. 2. Randomly-selected Campylobacter isolates (296 C. jejuni, 54 C. coli) recovered in 2017 and 2018, from Irish broiler neck skin and caeca were tested for their resistance to tetracycline, erythromycin, gentamicin, ciprofloxacin, nalidixic acid and streptomycin. 3. Overall, 45% of the Campylobacter spp. isolates tested were resistant to at least one antimicrobial. Tetracycline resistance (38%) was most prevalent in C. jejuni, followed by ciprofloxacin and nalidixic acid resistance (29%). In C. coli, resistance to ciprofloxacin and nalidixic acid (26%) was most prevalent followed by resistance to tetracycline (13%). Gentamicin resistance was undetected and resistance to streptomycin was low for C. jejuni (1%) and C. coli (4%). All C. jejuni isolates examined were erythromycin-sensitive, while 9% of C. coli isolates were erythromycin-resistant. Three multidrug-resistant C. coli isolates were recovered. 4. While antibiotic resistance rates were somewhat similar to figures reported nationally over the past 20 years, the prevalence of tetracycline resistance in C. jejuni has increased. The persistence of substantial ciprofloxacin resistance in the Irish broiler population was noteworthy, despite fluoroquinolones having been banned for growth promotion in Europe since 2006.


Assuntos
Infecções por Campylobacter , Campylobacter coli , Campylobacter jejuni , Campylobacter , Animais , Antibacterianos/farmacologia , Infecções por Campylobacter/tratamento farmacológico , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/veterinária , Galinhas , Farmacorresistência Bacteriana , Humanos , Irlanda/epidemiologia , Testes de Sensibilidade Microbiana/veterinária
8.
Anaesthesia ; 74(6): 758-764, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30793278

RESUMO

Demand for critical care among older patients is increasing in many countries. Assessment of frailty may inform discussions and decision making, but acute illness and reliance on proxies for history-taking pose particular challenges in patients who are critically ill. Our aim was to investigate the inter-rater reliability of the Clinical Frailty Scale for assessing frailty in patients admitted to critical care. We conducted a prospective, multi-centre study comparing assessments of frailty by staff from medical, nursing and physiotherapy backgrounds. Each assessment was made independently by two assessors after review of clinical notes and interview with an individual who maintained close contact with the patient. Frailty was defined as a Clinical Frailty Scale rating > 4. We made 202 assessments in 101 patients (median (IQR [range]) age 69 (65-75 [60-80]) years, median (IQR [range]) Acute Physiology and Chronic Health Evaluation II score 19 (15-23 [7-33])). Fifty-two (51%) of the included patients were able to participate in the interview; 35 patients (35%) were considered frail. Linear weighted kappa was 0.74 (95%CI 0.67-0.80) indicating a good level of agreement between assessors. However, frailty rating differed by at least one category in 47 (47%) cases. Factors independently associated with higher frailty ratings were: female sex; higher Acute Physiology and Chronic Health Evaluation II score; higher category of pre-hospital dependence; and the assessor having a medical background. We identified a good level of agreement in frailty assessment using the Clinical Frailty Scale, supporting its use in clinical care, but identified factors independently associated with higher ratings which could indicate personal bias.


Assuntos
Cuidados Críticos/métodos , Fragilidade/diagnóstico , Avaliação Geriátrica/métodos , Idoso , Idoso de 80 Anos ou mais , Estado Terminal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Escócia , Índice de Gravidade de Doença , País de Gales
9.
J Phys D Appl Phys ; 53(10)2019.
Artigo em Inglês | MEDLINE | ID: mdl-33060867

RESUMO

We explored the effect of a CoFe wedge inserted as a dusting layer (0.2 nm-0.4 nm thick) at the CoFeB/MgO interface of a sputtered Ta(2 nm)/W(3 nm)/CoFeB(0.9 nm)/MgO(3 nm)/Ta(2 nm) film-a typical structure for spin-orbit torque devices. Films were annealed at temperatures varying between 300 °C and 400 °C in an argon environment. Ferromagnetic resonance studies and vibrating sample magnetometry measurements were carried out to estimate the effective anisotropy field, the Gilbert damping, the saturation magnetization and the dead layer thickness as a function of the CoFe thickness and across several annealing temperatures. While the as-deposited films present only easy-plane anisotropy, a transition along the wedge from in-plane to out-of-plane was observed across several annealing temperatures, with evidence of a spin-reorientation transition separating the two regions.

10.
Ir Med J ; 112(9): 1001, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31651131

RESUMO

Introduction The purpose of this study was to compare obstetric and neonatal outcomes between women attending a specialised maternal medicine service and the general obstetric population. Methods Women attending from January 2011 to December 2016 were identified from the clinic database. Medical diagnosis, demographics, obstetric and neonatal outcomes were compared with data from hospital annual report 2014. Results 1873 women were compared with 8632 women who delivered at the hospital in 2014. Delivery before 34 weeks [82 (4.5%) vs 189 (2.2%)], induction of labour [761 (40.6%) vs 2664 (30.9%)] and delivery by Caesarean Section (CS) [664 (35%) vs 2479 (29%)] were higher p<0.001; but elective CS [334 (18%) vs 1425 (17%), p=0.18] did not differ between the two groups. Neonatal outcomes were similar. Conclusion Premature delivery, induction of labour and CS rates are higher in women with medical disorders in pregnancy. Encouragingly, 77% of women attempting vaginal birth in this group were successful.


Assuntos
Parto Obstétrico , Resultado da Gravidez , Parto Obstétrico/estatística & dados numéricos , Feminino , Humanos , Gravidez , Complicações na Gravidez/epidemiologia
11.
Med Oral Patol Oral Cir Bucal ; 24(2): e156-e164, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30818307

RESUMO

BACKGROUND: The aim was to evaluate the effect of silver loaded nanoparticles (NPs) application on the triboscopic, crystallographic and viscoelastic properties of demineralized dentin. Polymethylmetacrylate-based NPs and Ag loaded NPs were applied on demineralized dentin. MATERIAL AND METHODS: Treated and untreated surfaces were probed by a nanoindenter to test viscoelasticity, and by atomic force microscopy to test nanoroughness and collagen fibril diameter. X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging were also used. RESULTS: Dentin treated with Ag-NPs attained the lowest complex modulus, and the highest tan delta values after 7 days of storage. Dentin treated with undoped-NPs achieved the lowest nanoroughness and the greatest collagen bandwidths among groups. Crystals were identified as hydroxyapatite with the highest crystallographic maturity and crystallite size in dentin treated with undoped-NPs. Texture increased in all samples from 24 h to 7 d, except in dentin surfaces treated with Ag-NPs at 310 plane. Polyhedral, block-like, hexagonal or plate-like shaped apatite crystals constituted the bulk of minerals in dentin treated with Ag-NPs, after 7 d. Polyhedral or rounded/drop-like, and polymorphic in strata crystal apatite characterized the minerals when undoped-NPs were used, with more crystalline characteristics after 7 d than that found when Ag-NPs were applied. Ag-NPs application did not improve the mechanical performance of dentin and did not produce dentin remineralization. However, energy was dissipated through the dentin without showing stress concentration; contrary was occurring at dentin treated with undoped-NPs, that provoked bridge-like mineral deposits at the dentin surface. CONCLUSIONS: Ag-NPs application did not enhance the mechanical properties of cervical dentin, though the energy dissipation did not damage the dentin structure. Remineralization at dentin was not produced after Ag-NPs application, though improved crystallinity may lead to increase stability of the apatite that was generated at the dentin surface.


Assuntos
Dentina/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Remineralização Dentária , Colágeno , Humanos , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Polimetil Metacrilato/farmacologia , Propriedades de Superfície , Fatores de Tempo , Substâncias Viscoelásticas , Difração de Raios X
12.
BJOG ; 125(11): 1480-1487, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29575562

RESUMO

OBJECTIVE: We sought to identify fetal heart rate (FHR) characteristics that are associated with neonatal encephalopathy (NE). DESIGN: Retrospective case-control study. SETTING: A single medical centre in Shanghai, China, 2006-2015. SAMPLE: Women delivering a singleton, non-anomalous infant at ≥36 weeks' gestation diagnosed with NE (cases, n = 109) were compared with a group of women with unaffected infants (controls, n = 233). METHODS: Two physicians blinded to the outcome independently reviewed FHR tracings during the last 30 minutes of tracing prior to delivery. FHR characteristics were compared in the two groups and multivariable logistic regression was used to adjust for confounding. MAIN OUTCOME MEASURES: Adjusted odds ratio (aOR) and 95% confidence interval (CI) for the presence of specific FHR categories and characteristics. RESULTS: Category II FHR tracings were observed in 89% of women prior to delivery and were not independently associated with NE. Notably, a category III FHR was observed in 17.4% of women in the NE group compared with 0.9% of women in the control group (aOR 44.99, 95% CI 7.23-279.97). Bradycardia, minimal/absent variability, late decelerations and prolonged decelerations were independently associated with NE, whereas accelerations were protective. Similar findings were found when the cases were limited to NE with arterial cord pH <7.1 and in a subgroup analysis of women with category II tracings. CONCLUSIONS: Category III tracings, while infrequent, are not uncommon prior to delivery among fetuses who develop NE. In contrast, most FHR tracings are category II prior to delivery; however, individual FHR characteristics within this category are associated with NE. FUNDING: This research was supported by the Interdisciplinary Programme of Shanghai Jiao Tong University. TWEETABLE ABSTRACT: Category III tracings are not uncommon prior to delivery among fetuses who develop neonatal encephalopathy.


Assuntos
Encefalopatias/etiologia , Frequência Cardíaca Fetal/fisiologia , Doenças do Recém-Nascido/etiologia , Adulto , Encefalopatias/embriologia , Encefalopatias/fisiopatologia , Cardiotocografia , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Doenças do Recém-Nascido/embriologia , Doenças do Recém-Nascido/fisiopatologia , Modelos Logísticos , Análise Multivariada , Razão de Chances , Gravidez , Estudos Retrospectivos
13.
Ir Med J ; 111(10): 840, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-34191115

RESUMO

Aim Our aim was to present an overview of patterns of paediatric organ donation in the Republic of Ireland from January 2007 to January 2018. Methods We performed a retrospective audit of organ donation practice in paediatric intensive care units (PICU) in Ireland. Results Thirty-six children donated organs or tissue heart valves over the 11-year period. There were 13 paediatric organ donors between 2007 and 2012, this increased to 23 paediatric organ donors between 2013 and 2017. 2017 had the highest number of organ donors at 9 Conclusion Organ donation in Irish PICUs has increased over the last 11 years due to a combination of factors: improved resourcing and organization of Organ Donation Transplantation Ireland (ODTI), the establishment of clinical leads (both medical and nursing) in organ donation, a heightened awareness of organ donation and improved specialist Intensive Care dedicated consultant staffing. Finally organ donation is possible only through the generosity and altruism of bereaved families. Outcomes from donated organs have been excellent throughout the 11 year period audited.

14.
Ir Med J ; 111(3): 712, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30376230

RESUMO

Neural tube defects (NTD) are potentially preventable in two-thirds of cases by periconceptional maternal Folic Acid (FA) supplementation. A national audit for the years 2009-11 showed no decline in NTD rates over twenty years. The aim of this national audit was to determine trends/rates and inform revision of national FA supplementation and food fortification strategies. Of 274,732 live and stillbirths there were 121(42.0%) cases of anencephaly, 136(47.2%) cases of spina bifida and 31(10.8%) cases of encephalocoele giving a total of 288 and overall rate of 1.05/1000 compared with 1.04/1000 in 2009-11(NS). In the 184 women where the information was available, only 29.9%(n=55) reported starting FA before pregnancy. The number of cases diagnosed antenatally was 91%(n=262) and 53%(n=154) were live-born. This audit confirms that over a generation, healthcare interventions have not succeeded in decreasing the number of pregnancies in Ireland complicated by NTD, and that revised strategies need to be developed and implemented.


Assuntos
Auditoria Clínica , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Educação em Saúde/estatística & dados numéricos , Defeitos do Tubo Neural/prevenção & controle , Acesso à Informação , Anencefalia/epidemiologia , Anencefalia/prevenção & controle , Encefalocele/epidemiologia , Encefalocele/prevenção & controle , Feminino , Humanos , Incidência , Recém-Nascido , Irlanda/epidemiologia , Defeitos do Tubo Neural/diagnóstico , Defeitos do Tubo Neural/epidemiologia , Gravidez , Disrafismo Espinal/epidemiologia , Disrafismo Espinal/prevenção & controle , Natimorto/epidemiologia
15.
Med Oral Patol Oral Cir Bucal ; 23(6): e646-e655, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30341273

RESUMO

BACKGROUND: The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization. MATERIAL AND METHODS: Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used for the nano-dynamic mechanical analysis to estimate complex modulus (E*) and tan delta (δ). The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. AFM imaging and FESEM analysis were performed. RESULTS: After 21 d of storage, dentin surfaces treated with EDTA+calcypatite, PA+calcypatite and EDTA+oxipatite showed viscoelastic discrepancies between peritubular and intertubular dentin, meaning a risk for cracking and breakdown of the surface. At both 24 h and 21 d, tan δ values at intertubular dentin treated with the four treatments performed similar. At 21 d time point, intertubular dentin treated with PA+oxipatite achieved the highest complex modulus and nanohardness, i.e., highest resistance to deformation and functional mineralization, among groups. CONCLUSIONS: Intertubular and peritubular dentin treated with PA+oxipatite showed similar values of tan δ after 21 d of storage. This produced a favorable dissipation of energy with minimal energy concentration, preserving the structural integrity at the dentin surface.


Assuntos
Cimentos Dentários/farmacologia , Dentina/efeitos dos fármacos , Hidróxido de Sódio/farmacologia , Remineralização Dentária/métodos , Óxido de Zinco/farmacologia , Humanos , Técnicas In Vitro , Teste de Materiais , Propriedades de Superfície
16.
Mol Cancer ; 16(1): 49, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28241871

RESUMO

Matrix metalloproteinases (MMPs) play a critical role in cancer pathogenesis, including tumor growth and osteolysis within the bone marrow microenvironment. However, the anti-tumor effects of MMPs are poorly understood, yet have significant implications for the therapeutic potential of targeting MMPs. Host derived MMP-7 has previously been shown to support the growth of bone metastatic breast and prostate cancer. In contrast and underscoring the complexity of MMP biology, here we identified a tumor-suppressive role for host MMP-7 in the progression of multiple myeloma in vivo. An increase in tumor burden and osteolytic bone disease was observed in myeloma-bearing MMP-7 deficient mice, as compared to wild-type controls. We observed that systemic MMP-7 activity was reduced in tumor-bearing mice and, in patients with multiple myeloma this reduced activity was concomitant with increased levels of the endogenous MMP inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1). Our studies have identified an unexpected tumour-suppressive role for host-derived MMP-7 in myeloma bone disease in vivo, and highlight the importance of elucidating the effect of individual MMPs in a disease-specific context.


Assuntos
Neoplasias Ósseas/secundário , Metaloproteinase 7 da Matriz/genética , Metaloproteinase 7 da Matriz/metabolismo , Mieloma Múltiplo/patologia , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular , Progressão da Doença , Técnicas de Inativação de Genes , Humanos , Camundongos , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Transplante de Neoplasias , Microambiente Tumoral
17.
Am J Transplant ; 17(11): 2911-2921, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28397388

RESUMO

Solid organ transplant recipients have an elevated incidence of thyroid cancer. We evaluated a wide range of potential risk factors in a cohort of 229 300 U.S. solid organ transplant recipients linked with 15 stage/regional cancer registries (1987-2012). Incidence rate ratios (IRRs) were adjusted for age, sex, race/ethnicity, transplanted organ, year of transplantation, and time since transplantation. Hazard ratios (HRs) for death and/or graft failure were adjusted for age, sex, race/ethnicity, transplanted organ, and year of transplantation. After transplantation, 356 thyroid cancers were diagnosed. Thyroid cancer incidence was 2.50-fold higher in transplant recipients than the general population (95% confidence interval [CI] 2.25-2.77). Among recipients of different organs, kidney recipients had the highest incidence of thyroid cancer (IRR = 1.26, 95% CI 1.03-1.53). Elevated thyroid cancer incidence was associated with cholestatic liver disease/cirrhosis as an indication for liver transplantation (IRR = 1.69, 95% CI 1.09-2.63), hypertensive nephrosclerosis as an indication for kidney transplantation (IRR = 1.41, 95% CI 1.03-1.94), and longer prior dialysis among kidney recipients (5+ vs. <1 year, IRR = 1.92, 95% CI 1.32-2.80; p-trend <0.01). Posttransplantation diagnosis of thyroid cancer was associated with modestly increased risk of death (HR = 1.33, 95% CI 1.02-1.73). Overall, our results suggest that end-stage organ disease and longer duration of dialysis may contribute to higher thyroid cancer incidence in transplant recipients.


Assuntos
Transplante de Órgãos/efeitos adversos , Diálise Renal/estatística & dados numéricos , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/etiologia , Adulto , Fatores Etários , Idoso , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prognóstico , Sistema de Registros , Fatores de Risco , Transplantados , Estados Unidos/epidemiologia
18.
Pharmacol Res ; 117: 54-64, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27940205

RESUMO

The survival rates for patients with osteosarcoma have remained almost static for the past three decades. Current standard of care therapy includes chemotherapies such as doxorubicin, cisplatin, and methotrexate along with complete surgical resection and surgery with or without ifosfamide and etoposide for relapse, though outcomes are hoped to be improved through clinical trials. Additionally, increased understanding of the genetics, signaling pathways and microenvironmental factors driving the disease have led to the identification of promising agents and potential paths towards translation of an exciting array of novel targeted therapies. Here, we review the mechanism of action of these emerging therapies and how, with clinical translation, they can potentially improve the survival rates for osteosarcoma patients in the near future.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Osteossarcoma/tratamento farmacológico , Animais , Humanos , Osteossarcoma/mortalidade , Transdução de Sinais/efeitos dos fármacos , Taxa de Sobrevida , Microambiente Tumoral/efeitos dos fármacos
20.
Spinal Cord ; 55(11): 985-993, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28607522

RESUMO

STUDY DESIGN: Cross-sectional. OBJECTIVES: The objective of the study was to determine and report agreement in fracture risk stratification of adults with spinal cord injury (SCI) using (1) Canadian Association of Radiologists and Osteoporosis Canada (CAROC) and Canadian Fracture Risk Assessment (FRAX) tools with and without areal bone mineral density (aBMD) and (2) SCI-specific fracture thresholds. SETTING: Tertiary rehabilitation center, Ontario, Canada. METHODS: Community-dwelling adults with chronic SCI (n=90, C2-T12, AIS A-D) consented to participation. Femoral neck aBMD values determined 10-year fracture risk (CAROC and FRAX). Knee-region aBMD and distal tibia volumetric BMD values were compared to SCI-specific fracture thresholds. Agreements between CAROC and FRAX risk stratifications, and between fracture threshold risk stratification, were assessed using prevalence- and bias-adjusted Kappa statistics (PABAK). RESULTS: CAROC and FRAX assessment tools showed moderate agreement for post-menopausal women (PABAK=0.56, 95% confidence interval (CI): 0.27, 0.84) and men aged ⩾50 years (PABAK=0.51, 95% CI: 0.34, 0.67), with poor agreement for young men and pre-menopausal women (PABAK⩽0). Excellent agreement was evident between FRAX with and without aBMD in young adults and in those with motor incomplete injury (PABAK=0.86-0.92). In other subgroups, agreement ranged from moderate to substantial (PABAK=0.41-0.73). SCI-specific fracture thresholds (Eser versus Garland) showed poor agreement (PABAK⩽0). CONCLUSION: Fracture risk estimates among individuals with SCI vary substantially with the risk assessment tool. Use of SCI-specific risk factors to identify patients with high fracture risk is recommended until a validated SCI-specific tool for predicting fracture risk is developed.


Assuntos
Algoritmos , Fraturas Ósseas/complicações , Fraturas Ósseas/diagnóstico , Medição de Risco , Traumatismos da Medula Espinal/complicações , Adulto , Fatores Etários , Densidade Óssea , Doença Crônica , Estudos Transversais , Feminino , Fraturas Ósseas/epidemiologia , Humanos , Joelho/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Ossos Pélvicos/diagnóstico por imagem , Ossos Pélvicos/lesões , Estudos Prospectivos , Fatores Sexuais , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/epidemiologia
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