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1.
Pharm Res ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38955999

RESUMO

PURPOSE: To develop a toolkit of test methods for characterizing potentially critical quality attributes (CQAs) of topical semisolid products and to evaluate how CQAs influence the rate and extent of active ingredient bioavailability (BA) by monitoring cutaneous pharmacokinetics (PK) using an In Vitro Permeation Test (IVPT). METHODS: Product attributes representing the physicochemical and structural (Q3) arrangement of matter, such as attributes of particles and globules, were assessed for a set of test acyclovir creams (Aciclostad® and Acyclovir 1A Pharma) and compared to a set of reference acyclovir creams (Zovirax® US, Zovirax® UK and Zovirax® Australia). IVPT studies were performed with all these creams using heat-separated human epidermis, evaluated with both, static Franz-type diffusion cells and a flow through diffusion cell system. RESULTS: A toolkit developed to characterize quality and performance attributes of these acyclovir topical cream products identified certain differences in the Q3 attributes and the cutaneous PK of acyclovir between the test and reference sets of products. The cutaneous BA of acyclovir from the set of reference creams was substantially higher than from the set of test creams. CONCLUSIONS: This research elucidates how differences in the composition or manufacturing of product formulations can alter Q3 attributes that modulate myriad aspects of topical product performance. The results demonstrate the importance of understanding the Q3 attributes of topical semisolid drug products, and of developing appropriate product characterization tests. The toolkit developed here can be utilized to guide topical product development, and to mitigate the risk of differences in product performance, thereby supporting a demonstration of bioequivalence (BE) for prospective topical generic products and reducing the reliance on comparative clinical endpoint BE studies.

2.
J Math Biol ; 88(4): 48, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538962

RESUMO

We extend a previously published model for the dynamics of a single strain of an influenza-like infection. The model incorporates a waning acquired immunity to infection and punctuated antigenic drift of the virus, employing a set of coupled integral equations within a season and a discrete map between seasons. The long term behaviour of the model is demonstrated by examples where immunity to infection depends on the time since a host was last infected, and where immunity depends on the number of times that a host has been infected. The first scenario leads to complicated dynamics in some regions of parameter space, and to regions of parameter space with more than one attractor. The second scenario leads to a stable fixed point, corresponding to an identical epidemic each season. We also examine the model with both paradigms in combination, almost always but not exclusively observing a stable fixed point or periodic solution. Adding stochastic perturbations to the between season map fails to destroy the model's qualitative dynamics. Our results suggest that if the level of host immunity depends on the elapsed time since the last infection then the epidemiological dynamics may be unpredictable.


Assuntos
Epidemias , Vírus da Influenza A , Influenza Humana , Humanos , Estações do Ano
3.
Public Health ; 224: 185-194, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37820536

RESUMO

OBJECTIVE: The study aimed to identify, appraise and update evidence on the association between cold temperatures (i.e. <18°C) within homes (i.e. dwellings) and health and well-being outcomes. STUDY DESIGN: This study was a systematic review. METHODS: Seven databases (MEDLINE, Embase, Cochrane Database of Systematic Reviews, CINAHL, APA PsycInfo, Applied Social Sciences Index and Abstracts, Coronavirus Research Database) were searched for studies published between 2014 and 2022, which explored the association between cold indoor temperatures and health and well-being outcomes. Studies were limited to those conducted in temperate and colder climates due to the increased risk of morbidity and mortality during winter in those climatic zones. Studies were independently quality assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. RESULTS: Of 1209 studies, 20 were included for review. Study outcomes included cardiovascular (blood pressure, electrocardiogram abnormalities, blood platelet count), respiratory (chronic obstructive pulmonary disease symptoms, respiratory viral infection), sleep, physical performance and general health. Seventeen studies found exposure to cold indoor temperatures was associated with negative effects on health outcomes studied. Older individuals and those with chronic health problems were found to be more vulnerable to negative health outcomes. CONCLUSION: Evidence suggests that indoor temperatures <18°C are associated with negative health effects. However, the evidence is insufficient to allow clear conclusions regarding outcomes from specific temperature thresholds for different population groups. Significant gaps in the current evidence base are identified, including research on the impacts of cold indoor temperatures on mental health and well-being, studies involving young children, and the long-term health effects of cold indoor temperatures.

4.
J Urol ; 207(3): 573-580, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34694140

RESUMO

PURPOSE: Multiparametric magnetic resonance imaging (mpMRI) fails to identify some men with significant prostate cancer. Prostate-specific membrane antigen positron emission tomography/computerized tomography (PSMA PET/CT) is recommended for staging of prostate cancer, but its additional benefit above mpMRI alone in local evaluation for prostate cancer is unclear. The study aim was to evaluate the ability of mpMRI and PSMA PET/CT individually and in combination, to predict tumor location and Gleason score ≥3+4 on robot-assisted laparoscopic radical prostatectomy (RALP) histology. MATERIALS AND METHODS: We retrospectively reviewed 1,123 men with a preoperative mpMRI and 68Ga-PSMA PET/CT prior to a RALP. Tumor locations were collected from both imaging modalities and compared to totally embedded prostate histology. Lowest apparent diffusion coefficient value on mpMRI and the highest maximum standardized uptake value (SUVmax) on 68Ga-PSMA PET/CT were collected on the index lesions to perform analysis on detection rates. RESULTS: Median prostate specific antigen was 6. Median Gleason score on biopsy and RALP histology was 4+3. The index lesion and multifocal tumor detection were similar between mpMRI and 68Ga-PSMA PET/CT (p=0.10; p=0.11). When combining mpMRI and 68Ga-PSMA PET/CT, index Gleason score ≥3+4 cancer at RALP was identified in 92%. Only 10% of patients with Gleason score ≤3+4 on biopsy with an SUVmax <5 were upgraded to ≥4+3 on RALP histology, compared to 90% if the SUVmax was >11. CONCLUSIONS: The addition of a diagnostic 68Ga-PSMA PET/CT to mpMRI can improve the detection of significant prostate cancer and improve the ability to identify men suitable for active surveillance.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso , Biomarcadores Tumorais/sangue , Isótopos de Gálio , Radioisótopos de Gálio , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/cirurgia , Radioisótopos , Estudos Retrospectivos
5.
J Radiol Prot ; 42(2)2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35551120

RESUMO

The IAEA fundamental safety objective is'to protect people and the environment from harmful effects of ionizing radiation'and this must be done 'without unduly limiting the operation of facilities or the conduct of activities that give rise to radiation risks', while ensuring that people and the environment, present and future are protected against radiation risks (IAEA 2006Fundamental Safety Principles, Safety FundamentalsNo. SF-1). In addition,'protective actions to reduce existing or unregulated radiation risks must be justified and optimized'(IAEA 2006Fundamental Safety Principles, Safety FundamentalsNo. SF-1). An international system of radiological protection can be applied such that processes, such as remediation, can be systematically undertaken to address the wide range of'existing exposure situations'present globally. In doing so, decisions made regarding actions undertaken can be demonstrated to be'justified'and'optimized'(i.e. balanced), such that the amount of effort should be commensurate with the risk (applying a'graded approach'). In addition, protection of people and the environment can be demonstrated by comparing the actual exposure to appropriate criteria over the lifetime of remediation. This paper provides an overview of the current IAEA safety standards on remediation of sites or areas contaminated with residual radioactive material within the international system of radiological protection and provides practical examples of their application through case studies considered in IAEA international model validation programs.


Assuntos
Monitoramento de Radiação , Proteção Radiológica , Humanos
6.
Int J Cosmet Sci ; 43(1): 1-10, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32866296

RESUMO

OBJECTIVE: The permeation of hydrophilic molecules through the skin is still a challenge due to the barrier posed by stratum corneum, the outermost layer of the skin. Liposomes have frequently been used as carriers for different types of drugs and may also function as permeation enhancers. Propylene glycol has also been used as an edge activator in liposomes to increase the permeation. The aim of this work was to prepare liposomes containing an edge activator and loaded with caffeine to evaluate the potential of caffeine reaching the deeper layers in the skin. METHODS: The formulations were prepared by a top-down process using high-pressure homogenization at 200 00 psi for 10 min. They were characterized by size, polydispersity index (PI), zeta potential (ZP), pH, caffeine content and encapsulation efficiency (EE%) on preparation (time zero) and after 30 days. Cytotoxicity of blank and loaded liposomes was assessed by MTT proliferation assay with a normal keratinocyte cell line (HaCaT). In vitro permeation tests were performed with human skin in Franz cells over 24 h, and caffeine concentration was determined in the skin surface, stratum corneum, dermo-epidermal fraction and receptor medium by HPLC. RESULTS: The caffeine liposomes with (DL-Caf) or without propylene glycol (CL-Caf) showed, respectively, mean size 94.5 and 95.4 nm, PI 0.48 and 0.42, ZP + 1.3 and + 18.1 mV and caffeine content of 78.57 and 80.13%. IC50 values of caffeine in DL-Caf (3.59 v/v %) and CL-Caf (3.65 v/v %) were not significantly different from conventional blank liposome (3.27 v/v %). The DL-Caf formulation presented the best capability to enhance the caffeine permeation through the skin, resulting 1.94-folds higher than caffeine solution. Furthermore, the caffeine flux from DL-Caf was 1.56- and 3.05-folds higher than caffeine solution and CL-Caf, respectively. On the other hand, CL-Caf showed the lowest caffeine penetration revealing the importance of edge activator to aid hydrophilic drug penetration to all skin layers. CONCLUSION: The DL-Caf formulation tested was able to improve the permeation of caffeine through the stratum corneum and dermo-epidermal layers, suggesting that this delivery system may be effective for deep skin delivery of hydrophilic drugs.


OBJECTIF: La perm´eation de mol´ecules hydrophiles `a travers lapeau reste un d´efi en raison de la barri`ere oppos´ee par la couchecorn´ee, la couche la plus externe de la peau. Les liposomes ontfr´equemment ´et´e utilis´es comme supports pour diff´erents types dem´edicaments et peuvent ´egalement fonctionner comme des amplificateursde perm´eation. Le propyl`ene glycol a ´egalement ´et´e utilis´ecomme activateur dans les liposomes pour augmenter la perm´eation.Le but de ce travail ´etait de pr´eparer des liposomes contenantun activateur et charg´es de caf´eine pour ´evaluer le potentiel de lacaf´eine atteignant les couches les plus profondes de la peau. MÉTHODES: Les formulations sont pr´epar´ees par homog´en´eisationhaute pression `a 200 00 psi pendant 10 min. Elles sontcaract´eris´es par la taille des liposomes, l'indice de polydispersit´e(PI), le potentiel zˆeta (ZP), le pH, la teneur en caf´eine et l'efficacit´ed'encapsulation (EE%) `a la pr´eparation (temps z´ero) et apr`es 30jours. La cytotoxicit´e des liposomes `a blanc et charg´es est ´evalu´eepar un test de prolif´eration MTT avec une lign´ee cellulaire de k´eratinocytesnormale (HaCaT). Des tests de perm´eation in vitro sontr´ealis´es avec de la peau humaine dans des cellules de Franz pendant24 h, et la concentration de caf´eine est d´etermin´ee `a la surfacede la peau, dans la couche corn´ee, la fraction dermo-´epidermique et le milieu r´ecepteur par HPLC. RÉSULTATS: Les liposomes contenant de la caf´eine avec (DL-Caf)ou sans propyl`ene glycol (CL-Caf) pr´esentent respectivement unetaille moyenne de 94,5 et 95,4 nm, PI 0,48 et 0,42, ZP + 1,3 et +18,1 mV et une teneur en caf´eine de 78,57 et 80,13%. Les valeursIC50 de la caf´eine dans DL - Caf (3,59 %v/v) et CL - Caf (3,65 %v/v) ne sont pas significativement diff´erentes de celles du liposome `ablanc conventionnel (3,27 %v/v). La formulation DL-Caf est cellequi permet la meilleure perm´eation de la caf´eine, avec une quantit´ede caf´eine dans la peau 1,94 fois plus ´elev´ee que la solution decaf´eine. De plus, le flux de caf´eine de DL-Caf est 1,56 et 3,05 foisplus ´elev´e que la solution de caf´eine et CL-Caf, respectivement.D'autre part, CL-Caf montre la plus faible p´en´etration de caf´eine,r´ev´elant l'importance de l'activateur pour aider `a la p´en´etration dela mol´ecule hydrophile dans toutes les couches de la peau. CONCLUSION: La formulation DL-Caf test´ee am´eliore la perm´eationde la caf´eine `a travers la couche corn´ee et les couches dermo-´epidermiques, ce qui sugg`ere que ce syst`eme d'administration peutˆetre efficace pour l'administration cutan´ee profonde de mol´eculeshydrophiles.


Assuntos
Cafeína/farmacocinética , Lipossomos , Absorção Cutânea , Células Cultivadas , Difusão , Humanos
7.
Diabet Med ; 37(2): 256-266, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31365765

RESUMO

AIMS: Both fasting (FPG) and postprandial plasma glucose (PPG) contribute to HbA1c levels. We investigated the relationship between achievement of American Diabetes Association (ADA) and American Association of Clinical Endocrinologists (AACE) recommended FPG and/or PPG targets and glycaemic efficacy outcomes in two trials. METHODS: In this post hoc analysis, data from participants with Type 2 diabetes in the phase 3 LixiLan-O (NCT02058147) and LixiLan-L (NCT02058160) trials were evaluated to compare the relationship between achievement of society-recommended FPG and/or PPG targets and efficacy (HbA1c change, HbA1c goal attainment, weight change) and safety outcomes in the treatment groups. RESULTS: Across treatment arms, iGlarLixi achieved the highest proportion of participants meeting both ADA- and AACE-recommended FPG and PPG targets at study end in both trials. A higher proportion of participants in the iGlarLixi (fixed-ratio combination of insulin glargine and lixisenatide) vs. insulin glargine alone or lixisenatide alone treatment arms achieved HbA1c goals (P < 0.001 for overall comparisons), irrespective of ADA- or AACE-defined targets. Hypoglycaemia rates [any, documented symptomatic (plasma glucose ≤ 3.9 mmol/l), and clinically important (plasma glucose < 3.0 mmol/l)] were low across all groups. Participants treated with iGlarLixi tended to show weight loss or less weight gain compared with participants receiving insulin glargine alone. No differences were observed in average daily basal insulin dose at week 30 between the two treatment arms or across the different FPG and PPG target groups. CONCLUSION: Insulin glargine and lixisenatide as a fixed-ratio combination resulted in more participants reaching both FPG and PPG targets, leading to better HbA1c target attainment.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Jejum/metabolismo , Hipoglicemiantes/uso terapêutico , Insulina Glargina/uso terapêutico , Peptídeos/uso terapêutico , Período Pós-Prandial , Idoso , Diabetes Mellitus Tipo 2/metabolismo , Combinação de Medicamentos , Feminino , Hemoglobinas Glicadas/metabolismo , Controle Glicêmico , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
8.
J Appl Microbiol ; 128(4): 1163-1178, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31814258

RESUMO

AIMS: To characterize efficacy of the Bacillus subtilis BSB3 (BSB3) strain in the prevention of excessive exercise-induced side effects and in maintaining stability of the gut microbiota. METHODS AND RESULTS: Rats were pretreated by oral gavage with B. subtilis BSB3 (BSB3) or with phosphate-buffered saline (PBS) twice a day for 2 days, and were either exposed forced treadmill running or remained sedentary. Histological analysis of intestine, immunofluorescence staining of tight junction (TJ) proteins, serum lipopolysaccharide and intestinal fatty acid-binding protein assay, culture-based analysis and pyrosequencing for the gut microbiota were performed for each rat. Forced running resulted in a substantial decrease in intestinal villi height and total mucosa thickness, the depletion of Paneth cells, an inhibition of TJ proteins expression. Short-term treatment of rats with BSB3 before running prevented these adverse effects. Culture-based analysis of the gut microbiota revealed significant elevation of pathogenic microorganisms only in treadmill-exercised rats pretreated with PBS. High-throughput 16S rRNA gene sequencing also revealed an increase in pathobionts in this group. Preventive treatment of animals with BSB3 resulted in predominance of beneficial bacteria. CONCLUSIONS: BSB3 prevents excessive exercise-associated complications by beneficial modulation of the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study shows a new application of beneficial bacteria for prevention the adverse effects of excessive exercise.


Assuntos
Bacillus subtilis/fisiologia , Condicionamento Físico Animal/efeitos adversos , Probióticos , Administração Oral , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Lipopolissacarídeos/sangue , Masculino , Probióticos/administração & dosagem , Probióticos/farmacologia , Ratos
9.
Nature ; 505(7484): 520-4, 2014 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-24390352

RESUMO

Gravitationally bound three-body systems have been studied for hundreds of years and are common in our Galaxy. They show complex orbital interactions, which can constrain the compositions, masses and interior structures of the bodies and test theories of gravity, if sufficiently precise measurements are available. A triple system containing a radio pulsar could provide such measurements, but the only previously known such system, PSR B1620-26 (refs 7, 8; with a millisecond pulsar, a white dwarf, and a planetary-mass object in an orbit of several decades), shows only weak interactions. Here we report precision timing and multiwavelength observations of PSR J0337+1715, a millisecond pulsar in a hierarchical triple system with two other stars. Strong gravitational interactions are apparent and provide the masses of the pulsar M[Symbol: see text](1.4378(13), where M[Symbol: see text]is the solar mass and the parentheses contain the uncertainty in the final decimal places) and the two white dwarf companions (0.19751(15)M[Symbol: see text] and 0.4101(3))M[Symbol: see text], as well as the inclinations of the orbits (both about 39.2°). The unexpectedly coplanar and nearly circular orbits indicate a complex and exotic evolutionary past that differs from those of known stellar systems. The gravitational field of the outer white dwarf strongly accelerates the inner binary containing the neutron star, and the system will thus provide an ideal laboratory in which to test the strong equivalence principle of general relativity.

10.
Public Health ; 181: 135-140, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32014641

RESUMO

OBJECTIVES: This study sought to describe patient experiences and perceptions of a public health initiative designed to improve tuberculosis (TB) testing access using the tuberculin skin test (TST) in a community pharmacy setting. STUDY DESIGN: This was a cross-sectional study. METHODS: A telephonic survey of patients who had received a TST at one of twelve participating community pharmacies between August 2014 and July 2016 was conducted. The 26-question survey was developed by two pharmacists with expertise in TB management and one pharmacy student. Before administration the survey was peer-reviewed for clarity. Potential study patients were identified through TST records at the study pharmacies. English-speaking patients older than 18 years were eligible for study inclusion. Statistical differences in responses based on location were identified using chi-squared test for frequency comparisons with a P-value of <0.05 to determine statistical significance. RESULTS: A total of 1709 patients received a TST during the study period, of whom 431 were contacted and 325 participated, meeting the predetermined representative sample needed of 314 patients. The majority of study patients were female (67.1%) and white (81%). The mean age was 36 years (standard deviation = 14.1). A majority (68.3%) lived <5 miles from the TST pharmacy, while 45.2% of those with a primary care provider (PCP) (61.6% of respondents) lived within 5 miles of the PCP's office. Care was accessible and met patients' testing needs. For most patients (84.6%), the initial and follow-up appointments took < 20 min. Follow-up TST reading rate was 98.5%; 4.3% of tests were positive. Positive TST results were associated with use of a small city pharmacy (P = 0.003). Perception differences based on location were identified. CONCLUSIONS: Uptake of the TST service in the community pharmacy setting was high and patients reported positive experiences.


Assuntos
Serviços Comunitários de Farmácia/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Satisfação do Paciente , Teste Tuberculínico/métodos , Tuberculose/diagnóstico , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Farmácias , Farmacêuticos , Inquéritos e Questionários , Telefone
11.
Br J Dermatol ; 181(6): 1146-1155, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30908599

RESUMO

BACKGROUND: Genome-wide association studies (GWAS) have identified thousands of susceptibility variants, although most have been associated with small individual risk estimates that offer little predictive value. However, combining multiple variants into polygenic risk scores (PRS) may be more informative. Multiple studies have developed PRS composed of GWAS-identified variants for cutaneous cancers. This review highlights data from these studies. OBJECTIVES: To review published GWAS and PRS studies for melanoma, cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC), and discuss their potential clinical utility. METHODS: We searched PubMed and the National Human Genome Research Institute-European Bioinformatics Institute GWAS catalogue to identify relevant studies. RESULTS: Results from 21 GWAS (11 melanoma, 3 cSCC, 7 BCC) and 11 PRS studies are summarized. Six loci in pigmentation genes overlap between these three cancers (ASIP/RALY, IRF4, MC1R, OCA2, SLC45A2 and TYR). Additional loci overlap for cSCC/BCC and BCC/melanoma, but no other loci are shared between cSCC and melanoma. PRS for melanoma show roughly two-to-threefold increases in risk and modest improvements in risk prediction (2-7% increases). PRS are associated with twofold and threefold increases in risk of cSCC and BCC, respectively, with small improvements (2% increase) in predictive ability. CONCLUSIONS: Existing data indicate that PRS may offer small, but potentially meaningful, improvements to risk prediction. Additional research is needed to clarify the potential utility of PRS in cutaneous carcinomas. Clinical translation will require well-powered validation studies incorporating known risk factors to evaluate PRS as tools for screening. What's already known about this topic? Over 50 susceptibility loci for melanoma, basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) have been identified in genome-wide association studies (GWAS). Polygenic risk scores (PRS) using variants identified from GWAS have also been developed for melanoma, BCC and cSCC, and investigated with respect to clinical risk prediction. What does this study add? This review provides an overview of GWAS findings and the potential clinical utility of PRS for melanoma, BCC and cSCC.


Assuntos
Carcinoma Basocelular/genética , Carcinoma de Células Escamosas/genética , Estudo de Associação Genômica Ampla , Melanoma/genética , Neoplasias Cutâneas/genética , Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/epidemiologia , Carcinoma Basocelular/prevenção & controle , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/prevenção & controle , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Melanoma/diagnóstico , Melanoma/epidemiologia , Melanoma/prevenção & controle , Herança Multifatorial , Medição de Risco/métodos , Fatores de Risco , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/prevenção & controle
12.
J Math Biol ; 78(3): 607-624, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30155777

RESUMO

We propose and analyse a model for the dynamics of a single strain of an influenza-like infection. The model incorporates waning acquired immunity to infection and punctuated antigenic drift of the virus, employing a set of differential equations within a season and a discrete map between seasons. We show that the between-season map displays a variety of qualitatively different dynamics: fixed points, periodic solutions, or more complicated behaviour suggestive of chaos. For some example parameters we demonstrate the existence of two distinct basins of attraction, that is the initial conditions determine the long term dynamics. Our results suggest that there is no reason to expect influenza dynamics to be regular, or to expect past epidemics to give a clear indication of future seasons' behaviour.


Assuntos
Influenza Humana/epidemiologia , Modelos Biológicos , Variação Antigênica , Antígenos Virais/genética , Número Básico de Reprodução/estatística & dados numéricos , Epidemias , Deriva Genética , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Vírus da Influenza A/genética , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Influenza Humana/virologia , Conceitos Matemáticos , Estações do Ano
13.
Am J Transplant ; 18(7): 1783-1789, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29509295

RESUMO

Donor-specific antibodies (DSAs) are associated with an increased risk of antibody-mediated rejection and graft failure. In BENEFIT and BENEFIT-EXT, kidney-transplant recipients were randomized to receive belatacept more intense (MI)-based, belatacept less intense (LI)-based, or cyclosporine-based immunosuppression for up to 7 years (84 months). The presence/absence of HLA-specific antibodies was determined at baseline, at months 6, 12, 24, 36, 48, 60, and 84, and at the time of clinically suspected episodes of acute rejection, using solid-phase flow-cytometry screening. Samples from anti-HLA-positive patients were further tested with a single-antigen bead assay to determine antibody specificities, presence/absence of DSAs, and mean fluorescence intensity (MFI) of any DSAs present. In BENEFIT, de novo DSAs developed in 1.4%, 3.5%, and 12.1% of belatacept MI-treated, belatacept LI-treated, and cyclosporine-treated patients, respectively. The corresponding values in BENEFIT-EXT were 3.8%, 1.1%, and 11.2%. Per Kaplan-Meier analysis, de novo DSA incidence was significantly lower in belatacept-treated vs cyclosporine-treated patients over 7 years in both studies (P < .01). In patients who developed de novo DSAs, belatacept-based immunosuppression was associated with numerically lower MFI vs cyclosporine-based immunosuppression. Although derived post hoc, these data suggest that belatacept-based immunosuppression suppresses de novo DSA development more effectively than cyclosporine-based immunosuppression.


Assuntos
Abatacepte/uso terapêutico , Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Isoanticorpos/sangue , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Adulto , Feminino , Seguimentos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Humanos , Tolerância Imunológica/imunologia , Imunossupressores/uso terapêutico , Agências Internacionais , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco , Transplantados
14.
Am J Transplant ; 18(7): 1774-1782, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29573335

RESUMO

BENEFIT and BENEFIT-EXT were phase III studies of cytotoxic T-cell crossmatch-negative kidney transplant recipients randomized to belatacept more intense (MI)-based, belatacept less intense (LI)-based, or cyclosporine-based immunosuppression. Following study completion, presence/absence of HLA-specific antibodies was determined centrally via solid-phase flow cytometry screening. Stored sera from anti-HLA-positive patients were further tested with a single-antigen bead assay to determine antibody specificities, presence/absence of donor-specific antibodies (DSAs), and mean fluorescent intensity (MFI) of any DSAs present. The effect of belatacept-based and cyclosporine-based immunosuppression on MFI was explored post hoc in patients with preexisting DSAs enrolled to BENEFIT and BENEFIT-EXT. In BENEFIT, preexisting DSAs were detected in 4.6%, 4.9%, and 6.3% of belatacept MI-treated, belatacept LI-treated, and cyclosporine-treated patients, respectively. The corresponding values in BENEFIT-EXT were 6.0%, 5.7%, and 9.2%. In both studies, most preexisting DSAs were of class I specificity. Over the first 24 months posttransplant, a greater proportion of preexisting DSAs in belatacept-treated versus cyclosporine-treated patients exhibited decreases or no change in MFI. MFI decline was more apparent with belatacept MI-based versus belatacept LI-based immunosuppression in both studies and more pronounced in BENEFIT-EXT versus BENEFIT. Although derived post hoc, these data suggest that belatacept-based immunosuppression decreases preexisting DSAs more effectively than cyclosporine-based immunosuppression.


Assuntos
Abatacepte/uso terapêutico , Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Isoanticorpos/sangue , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Feminino , Seguimentos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Humanos , Tolerância Imunológica/imunologia , Imunossupressores/uso terapêutico , Agências Internacionais , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco , Transplantados
15.
Osteoarthritis Cartilage ; 26(12): 1651-1657, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30172836

RESUMO

OBJECTIVE: To evaluate the relationship of telomere length to the prevalence and incidence of hand osteoarthritis in a longitudinal cohort. DESIGN: We conducted a cross-sectional and longitudinal analysis of data from a subset of participants in the Osteoarthritis Initiative (OAI) recruited between February 2004 and May 2006. 274 individuals were eligible for the study based on availability of both baseline and 48-month hand radiographs and peripheral blood leucocyte telomere length data. Mean telomere length of peripheral blood leukocytes (PBL)s from the DNA samples was determined using a validated quantitative polymerase chain reaction (PCR)-based assay, and hand radiographs were analyzed and graded using the Kellgren-Lawrence scale. RESULTS: In joint -level analyses, prevalent Interphalangeal Joint Osteoarthritis (IPJOA) was significantly associated with PBL telomere length in the baseline sample in unadjusted analyses (RR = 2.84; 95% CI:0.87-9.29) or in models adjusted for age, sex, and body mass index (aRR = 1.10; 95% CI: 0.96-1.27). The association in crude and adjusted analyses appeared slightly stronger with incident IPJOA, especially in the subset with normal hands at baseline (aRR = 1.62; 95% CI: 1.02-2.57). PBL telomere length was also associated with prevalent HOA at baseline (significant in unadjusted analysis: RR = 1.22; 95% CI 1.06-1.42), but not after adjusting for covariates: aRR = 1.12; 95% CI: 0.96-1.30). The magnitude of association was stronger for incident HOA, especially incident symptomatic HOA (aRR = 1.53; 95% CI: 1.09-2.15). CONCLUSIONS: In summary, the results of this exploratory analysis are confirmatory of previous work showing a cross-sectional relationship between telomere length and HOA and add to the field by demonstrating an even stronger association with incident IPJOA, both radiographic and symptomatic.


Assuntos
Articulação da Mão/diagnóstico por imagem , Leucócitos/fisiologia , Osteoartrite/genética , Encurtamento do Telômero/fisiologia , Idoso , Estudos Transversais , Feminino , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Osteoartrite/sangue , Osteoartrite/diagnóstico por imagem , Osteoartrite/epidemiologia , Prevalência , Telômero/fisiologia , Estados Unidos/epidemiologia
16.
Theor Popul Biol ; 121: 26-32, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29601833

RESUMO

New Zealand has one of the highest (per capita) incidences of human leptospirosis in the world. It is the highest occurring occupational disease in New Zealand, often transmitted from livestock such as deer, sheep and cattle to humans. A cyclical model, showing the dynamics of infection of leptospirosis in farmed livestock in New Zealand, is presented. The limit cycle, bifurcation diagram and quasi-R0 value of the system are determined. Leptospire death rate is used as a control parameter. Previously published parameter values are used in a case study to produce figures demonstrating analytical results. The model is used to predict conditions under which the infection will persist in the population.


Assuntos
Modelos Animais de Doenças , Leptospirose/veterinária , Doenças dos Ovinos/epidemiologia , Animais , Leptospirose/epidemiologia , Gado/microbiologia , Modelos Teóricos , Nova Zelândia/epidemiologia , Fatores de Risco , Ovinos
17.
Eur Radiol ; 28(12): 5182-5194, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29846804

RESUMO

PURPOSE: To compare the efficacy of use of digital breast tomosynthesis (DBT) with standard digital mammography (DM) workup views in the breast cancer assessment clinic. MATERIALS AND METHODS: The Tomosynthesis Assessment Clinic trial (TACT), conducted between 16 October 2014 and 19 April 2016, is an ethics-approved, monocenter, multireader, multicase split-plot reading study. After written informed consent was obtained, 144 females (age > 40 years) who were recalled to the assessment clinic were recruited into TACT. These cases (48 cancers) were randomly allocated for blinded review of (1) DM workup and (2) DBT, both in conjunction with previous DM from the screening examination. Fifteen radiologists of varying experience levels in the Australia BreastScreen Program were included in this study, wherein each radiologist read 48 cases (16 cancers) in 3 non-overlapping blocks. Diagnostic accuracy was measured by means of sensitivity, specificity, and positive (PPV) and negative predictive values (NPV). The receiver-operating characteristic area under the curve (AUC) was calculated to determine radiologists' performances. RESULTS: Use of DBT (AUC = 0.927) led to improved performance of the radiologists (z = 2.62, p = 0.008) compared with mammography workup (AUC = 0.872). Similarly, the sensitivity, specificity, PPV, and NPV of DBT (0.93, 0.75, 0.64, 0.96) were higher than those of the workup (0.90, 0.56, 0.49, 0.92). Most radiologists (80%) performed better with DBT than standard workup. Cancerous lesions on DBT appeared more severe (U = 33,172, p = 0.02) and conspicuous (U = 24,207, p = 0.02). There was a significant reduction in the need for additional views (χ2 = 17.63, p < 0.001) and recommendations for ultrasound (χ2 = 8.56, p = 0.003) with DBT. CONCLUSIONS: DBT has the potential to increase diagnostic accuracy and simplify the assessment process in the breast cancer assessment clinic. KEY POINTS: • Use of DBT in the assessment clinic results in increased diagnostic accuracy. • Use of DBT in the assessment clinic improves performance of radiologists and also increases the confidence in their decisions. • DBT may reduce the need for additional views, ultrasound imaging, and biopsy.


Assuntos
Neoplasias da Mama/diagnóstico , Mamografia/métodos , Programas de Rastreamento/métodos , Intensificação de Imagem Radiográfica/métodos , Austrália/epidemiologia , Neoplasias da Mama/epidemiologia , Feminino , Humanos , Incidência , Curva ROC
18.
Prev Med ; 117: 69-75, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29627511

RESUMO

BACKGROUND: Smoking prevalence is declining at a slower rate in rural than urban settings in the United States (U.S.), and known predictors of smoking do not readily account for this trend difference. Given that socioeconomic and psychosocial determinants of health disparities accumulate in rural settings and that life-course disadvantages are often greater in women than men, we examined whether smoking trends are different for rural and urban men and women. METHOD: We used yearly cross-sectional data (n = 303,311) from the U.S. National Survey on Drug Use and Health (NSDUH) from 2007 through 2014 to compare cigarette smoking trends in men and women across rural and urban areas. Current smoking status was modelled using logistic regression controlling for confounding risk factors. RESULTS: Regression derived graphs predicting unadjusted prevalence estimates and 95% confidence bands revealed that whereas the smoking trends of rural men, urban men, and urban women significantly declined from 2007 to 2014, the trend for rural women was flat. Controlling for demographic, socioeconomic and psychosocial predictors of smoking did not explain rural women's significantly different trend from those of the other three groups. CONCLUSION: Rural women lag behind rural men, urban men and urban women in decreasing smoking, a health disparity finding that supports the need for tobacco control and regulatory policies and interventions that are more effective in reducing smoking among rural women.


Assuntos
População Rural/estatística & dados numéricos , Fumar/epidemiologia , Produtos do Tabaco/estatística & dados numéricos , Uso de Tabaco/tendências , População Urbana/estatística & dados numéricos , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Fatores Sexuais , Fumar/tendências , Fatores Socioeconômicos , Estados Unidos/epidemiologia , Adulto Jovem
19.
Nanotechnology ; 29(25): 255301, 2018 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-29596058

RESUMO

Soft nanoimprinted titanium dioxide (TiO2) substrates decorated with methylammonium lead halide perovskite (MAPbI3) crystals were fabricated by controlling the perovskite precursor concentration and volume during spin coat processing combined with the use of hydrophobic TiO2 templates. The patterned growth was demonstrated with different perovskite crystallization methods. We investigated and successfully demonstrated the controlled assembly of two MAPbI3 nanomaterials, one a nanocomposite formed between the perovskite and a hole conducting polymer poly(2,5-bis(N-methyl-N-hexylamino)phenylene vinylene) (BAMPPV), and a second formed from perovskite crystals using common solution based MAPbI3 growth methods (1-step and 2-step processing). Both types of MAPbI3 crystals were fabricated on hydrophobic TiO2 nanotemplates composed of nanowells or grating patterns. Patterned areas as large as 100 µm × 100 µm were achieved. We examined and characterized the substrates using atomic force microscopy, scanning electron microscopy, x-ray diffraction, and energy dispersive spectroscopy. We present the optical properties (i.e. fluorescence and transmission) of soft nanoimprinted nanowells decorated with perovskites demonstrating the successful synthesis of MAPbI3 perovskite nanocrystals. As an example of their use, we demonstrate a two terminal device and show photocurrent response of a perovskite patterned micro-grating. Our method is a nondestructive approach to nanopatterning perovskites, and produces patterned arrays that maintain their photo-electric properties. The results presented herein suggests an attractive route to developing nanopatterned and small area perovskite substrates for applications in photovoltaics, x-ray sensing/detection, image sensor arrays, and others.

20.
BMC Nephrol ; 19(1): 89, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29665795

RESUMO

BACKGROUND: Removal of uraemic toxins is inadequate using current dialysis strategies. A new class of dialysis membranes have been developed that allow clearance of larger middle molecules. The REMOVAL-HD study (a tRial Evaluating Mid cut-Off Value membrane clearance of Albumin and Light chains in HaemoDialysis patients) will address safety, efficacy and the impact on patient-centred outcomes with the use of a mid cut-off (MCO) dialyser in a chronic haemodialysis (HD) population. METHODS: REMOVAL-HD is an open label, prospective, non-randomised, single-arm, multi-centre device study in 85 chronic HD participants. All visits will be conducted during regular HD sessions and participants will undergo a 1 month wash-in period using a standardised high flux dialyser, 6 months of intervention with a MCO dialyser and 1 month of wash-out using a high flux dialyser. The primary endpoint is change in pre-dialysis concentrations of serum albumin, with secondary endpoints including the efficacy of clearance of free light chains and ß-2 microglobulin, and patient-centred outcomes including quality of life, symptom burden, functional status, nutritional status, hospitalisation and death. DISCUSSION: MCO dialysers are a novel form of HD membrane. The REMOVAL-HD study is a pivotal study designed to monitor the immediate and medium-term effects following exposure to this dialyser. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry Number (ANZCTRN) 12616000804482 . Date of registration - 21/06/2016.


Assuntos
Cadeias lambda de Imunoglobulina/sangue , Membranas Artificiais , Diálise Renal/instrumentação , Insuficiência Renal Crônica/terapia , Projetos de Pesquisa , Albumina Sérica/metabolismo , Adulto , Efeitos Psicossociais da Doença , Hospitalização , Humanos , Estado Nutricional , Avaliação de Resultados da Assistência ao Paciente , Estudos Prospectivos , Qualidade de Vida , Diálise Renal/efeitos adversos , Diálise Renal/métodos , Insuficiência Renal Crônica/sangue , Análise de Sobrevida , Microglobulina beta-2/sangue
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