Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 126
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Alzheimer Dis Assoc Disord ; 37(2): 145-148, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36030814

RESUMO

Behavioral-variant frontotemporal dementia (bvFTD) is challenging to recognize, and often misdiagnosed as depression (DEP). Evidence suggests changes in social cognition (SoCog) precede general cognitive decline in bvFTD. Currently, there are no screening measures of social cognition. 17 bvFTD, 16 DEP, and 18 control participants underwent 6 SoCog tests measuring: emotion recognition; theory of mind; empathy; insight. We used χ 2 , Wilcoxon rank sum, Kruskal-Wallis tests to compare groups, with decision tree analysis to identify items that best differentiated bvFTD from DEP. bvFTD performed significantly worse on all SoCog tasks compared with other groups. Decision tree analysis yielded a 5-item test with ROC area under the curve of 0.973 (95% CI: 0.928, 1.0) for differentiating bvFTD versus depression. These results suggest that it may be feasible to develop a screening measure of social cognition.


Assuntos
Demência Frontotemporal , Humanos , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/psicologia , Projetos Piloto , Cognição Social , Depressão/diagnóstico , Testes Neuropsicológicos , Cognição
2.
World J Surg Oncol ; 21(1): 152, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37198644

RESUMO

BACKGROUND: The role of adjuvant chemotherapy (AC) in stage III rectal cancer (RC) has been argued based on evidence from its use in colon cancer. Previous trials have analysed disease-free and overall survivals as endpoints, rather than disease recurrence. This study compares the competing risks incidences of recurrence and cancer-specific death between patients who did and did not receive AC for stage III RC. METHODS: Consecutive patients who underwent a potentially curative resection for stage III RC (1995-2019) at Concord Hospital, Sydney, Australia, were studied. AC was considered following multidisciplinary discussion. Primary outcome measures were the competing risks incidences of disease recurrence and cancer-specific death. Associations between these outcomes and use of AC (and other variables) were tested by regression modelling. RESULTS: Some 338 patients (213 male, mean age 64.4 years [SD12.7]) were included. Of these, 208 received AC. The use of AC was associated with resection year (adjusted OR [aOR] 1.74, 95%CI 1.27-2.38); age ≥75 years (aOR0.04, 95%CI 0.02-0.12); peripheral vascular disease (aOR0.08, 95%CI 0.01-0.74); and postoperative abdomino-pelvic abscess (aOR0.23, 95%CI 0.07-0.81). One hundred fifty-seven patients (46.5%) were diagnosed with recurrence; death due to RC occurred in 119 (35.2%). After adjustment for the competing risk of non-cancer death, neither recurrence nor RC-specific death was associated with AC (HR0.97, 95%CI 0.70-1.33 and HR0.72, 95%CI 0.50-1.03, respectively). CONCLUSION: This study found no significant difference in either recurrence or cancer-specific death between patients who did and did not receive AC following curative resection for stage III RC.


Assuntos
Neoplasias do Colo , Neoplasias Retais , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/cirurgia , Neoplasias Retais/tratamento farmacológico , Neoplasias do Colo/patologia , Quimioterapia Adjuvante , Estudos Retrospectivos
3.
Ecol Lett ; 25(3): 673-685, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35199917

RESUMO

Climate change is predicted to drive geographical range shifts, leading to fluctuations in species richness (SR) worldwide. However, the effect of these changes on functional diversity (FD) remains unclear, in part because comprehensive species-level trait data are generally lacking at global scales. Here, we use morphometric and ecological traits for 8268 bird species to estimate the impact of climate change on avian FD. We show that future bird assemblages are likely to undergo substantial shifts in trait structure, with a magnitude of change greater than predicted from SR alone, and a direction of change varying according to geographical location and trophic guild. For example, our models predict that FD of insect predators will increase at higher latitudes with concurrent losses at mid-latitudes, whereas FD of seed dispersing birds will fluctuate across the tropics. Our findings highlight the potential for climate change to drive continental-scale shifts in avian FD with implications for ecosystem function and resilience.


Assuntos
Mudança Climática , Ecossistema , Animais , Biodiversidade , Aves , Geografia
4.
Ann Surg ; 276(1): e24-e31, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33074895

RESUMO

OBJECTIVE: To examine the independent prognostic value of ALN status in patients with stage III CRC. SUMMARY OF BACKGROUND DATA: Early CRC staging classified nodal involvement by level of involved nodes in the operative specimen, including both locoregional and apical node status, in contrast to the American Joint Committee on Cancer/tumor nodes metastasis (TNM) system where tumors are classified by the number of nodes involved. Whether ALN status has independent prognostic value remains controversial. METHODS: Consecutive patients who underwent curative resection for Stage III CRC from 1995 to 2012 at Concord Hospital, Sydney, Australia were studied. ALN status was classified as: (i) ALN absent, (ii) ALN present but not histologically involved, (iii) ALN present and involved. Outcomes were the competing risks incidence of CRC recurrence and CRC-specific death. Associations between these outcomes and ALN status were compared with TNM N status results. RESULTS: In 706 patients, 69 (9.8%) had an involved ALN, 398 (56.4%) had an uninvolved ALN and 239 (33.9%) had no ALN identified. ALN status was not associated with tumor recurrence [adjusted hazard ratio (HR) 1.02, 95% confidence interval (CI) 0.84-1.26] or CRC-specific death (HR 1.14, CI 0.91-1.43). However, associations persisted between TNM N-status and both recurrence (HR 1.58, CI 1.21-2.06) and CRC-specific death (HR 1.59, CI 1.19-2.12). CONCLUSIONS: No further prognostic information was conferred by ALN status in patients with stage III CRC beyond that provided by TNM N status. ALN status is not considered to be a useful additional component in routine TNM staging of CRC.


Assuntos
Neoplasias Colorretais , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Humanos , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Medição de Risco
5.
Ecol Lett ; 24(4): 891-907, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33524221

RESUMO

The spread of invasive species is a threat to ecosystems worldwide. However, we know relatively little about how invasive species affect the behaviour of native animals, even though behaviour plays a vital role in the biotic interactions which are key to understanding the causes and impacts of biological invasions. Here, we explore how invasive plants - one of the most pervasive invasive taxa - impact the behaviour of native animals. To promote a mechanistic understanding of these behavioural impacts, we begin by introducing a mechanistic framework which explicitly considers the drivers and ecological consequences of behavioural change, as well as the moderating role of environmental context. We then synthesise the existing literature within this framework. We find that while some behavioural impacts of invasive plants are relatively well-covered in the literature, others are supported by only a handful of studies and should be explored further in the future. We conclude by identifying priority topics for future research, which will benefit from an interdisciplinary approach uniting invasion ecology with the study of animal behaviour and cognition.


Assuntos
Ecossistema , Plantas , Animais , Comportamento Animal , Espécies Introduzidas
6.
Colorectal Dis ; 23(10): 2604-2618, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34252253

RESUMO

AIM: Clinical presentation with large bowel obstruction has been proposed as a predictor of poor long-term oncological outcomes after resection for colorectal cancer. This study examines the association between obstruction and recurrence and cancer-specific death after resection for colon cancer. METHOD: Consecutive patients who underwent resection for colon cancer between 1995 and 2014 were drawn from a prospectively recorded hospital database with all surviving patients followed for at least 5 years. The outcomes of tumour recurrence and colon cancer-specific death were assessed by competing risks multivariable techniques with adjustment for potential clinical and pathological confounding variables. RESULTS: Recurrence occurred in 271 of 1485 patients who had a potentially curative resection. In bivariate analysis, obstruction was significantly associated with recurrence [hazard ratio (HR) 2.23, CI 1.52-3.26, p < 0.001] but this association became nonsignificant after adjustment for confounders (HR 1.53, CI 0.95-2.46, p = 0.080). Colon cancer-specific death occurred in 238 of 295 patients who had a noncurative resection. Obstruction was not significantly associated with cancer-specific death (HR 1.02, CI 0.72-1.45, p = 0.903). In patients who had a noncurative resection, the competing risks incidence of colon cancer-specific death was not significantly greater in obstructed than in unobstructed patients (HR 1.02, CI 0.72-1.45, p = 0.903). CONCLUSION: Whilst the immediate clinical challenge of an individual patient presenting with large bowel obstruction must be addressed by the surgeon, the patient's long-term oncological outcomes are unrelated to obstruction per se.


Assuntos
Neoplasias do Colo , Obstrução Intestinal , Colectomia , Neoplasias do Colo/complicações , Neoplasias do Colo/cirurgia , Humanos , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Recidiva Local de Neoplasia , Medição de Risco
7.
Mod Pathol ; 33(7): 1350-1359, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32047232

RESUMO

Sarcoma is a rare disease affecting both bone and connective tissue and with over 100 pathologic entities, differential diagnosis can be difficult. Complementing immune-histological diagnosis with current ancillary diagnostic techniques, including FISH and RT-PCR, can lead to inconclusive results in a significant number of cases. We describe here the design and validation of a novel sequencing tool to improve sarcoma diagnosis. A NGS DNA capture panel containing probes for 87 fusion genes and 7 genes with frequent copy number changes was designed and optimized. A cohort of 113 DNA samples extracted from soft-tissue and bone sarcoma FFPE material with clinical FISH and/or RT-PCR results positive for either a translocation or gene amplification was used for validation of the NGS method. Sarcoma-specific translocations or gene amplifications were confirmed in 110 out of 113 cases using FISH and/or RT-PCR as gold-standard. MDM2/CDK4 amplification and a total of 25 distinct fusion genes were identified in this cohort of patients using the NGS approach. Overall, the sensitivity of the NGS panel is 97% with a specificity of 100 and 0% failure rate. Targeted NGS appears to be a feasible and cost-effective approach to improve sarcoma subtype diagnosis with the ability to screen for a wide range of genetic aberrations in one test.


Assuntos
Biomarcadores Tumorais/análise , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sarcoma/diagnóstico , Análise de Sequência de DNA/métodos , Biomarcadores Tumorais/genética , Humanos , Sarcoma/genética , Sensibilidade e Especificidade
8.
Spinal Cord ; 57(3): 221-228, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30262878

RESUMO

STUDY DESIGN: A prospective, parallel randomized controlled trial (RCT). OBJECTIVES: To test the preliminary effects of an online resource targeted to job-seekers with spinal cord injury or disorder (SCI/D), and to determine the feasibility of proceeding to a full-scale RCT. SETTING: A community cohort in Australia. METHODS: Forty-eight adults (M = 42 years, SD = 10.95, 27 males) were randomized to receive 4-weeks access to the Work and SCI resource (n = 25) or to a wait-list control group (n = 23). The Work and SCI intervention involved six stand-alone learning modules which provided job-searching and career-planning information through text, videos, and interactive activities. Self-report measures were administered at baseline and after 4 weeks: Job Procurement Self-Efficacy Scale (JSES), Life Orientation Test-Revised (LOT-R), and Patient Health Questionnaire-9 (PHQ-9). RESULTS: Online usage data identified high uptake of the Work and SCI resource, although study attrition was problematic. Intention-to-treat analyses failed to reach statistical significance, whereas complete data revealed a significant interaction effect for optimism (LOT-R). CONCLUSION: Further research to develop and enhance Work and SCI is indicated. Remediable strategies to optimize recruitment and statistical power in a future definitive RCT are discussed. SPONSORSHIP: This project was funded by the auDA Foundation (project 16019).


Assuntos
Emprego , Internet , Terapia Ocupacional , Doenças da Medula Espinal/reabilitação , Traumatismos da Medula Espinal/reabilitação , Telerreabilitação , Adulto , Emprego/psicologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Otimismo , Aceitação pelo Paciente de Cuidados de Saúde , Projetos Piloto , Autoeficácia , Doenças da Medula Espinal/psicologia , Traumatismos da Medula Espinal/psicologia , Resultado do Tratamento , Adulto Jovem
9.
Dis Colon Rectum ; 61(1): 67-76, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29215479

RESUMO

BACKGROUND: Most patients with Crohn's disease still require surgery despite significant advances in medical therapy, surveillance, and management strategies. OBJECTIVE: The purpose of this study was to assess surgical strategies and outcomes in Crohn's disease, including surgical recurrence and emergency surgery. DESIGN: This was a multicenter, retrospective review of a prospectively collected database. SETTINGS: A specialist-referred cohort of patients with Crohn's disease between 1970 and 2009 was studied. PATIENTS: Included were 972 patients with Crohn's disease who were referred to the Sydney Inflammatory Bowel Disease cohort database. MAIN OUTCOME MEASURES: Main outcomes of interest were the rates of major abdominal and perianal surgery between decades (1970-1979, 1980-1989, 1990-1999, and 2000-2009), indications for surgery, types of procedure performed, rate of elective and emergency surgery, risk of surgical recurrence, and predictive factors for surgery. RESULTS: Between 1970 and 2009, the overall risks of surgery within 5, 10, and 15 years of diagnosis were 31.7%, 43.3%, and 48.4%. The median time to first surgery from time of diagnosis was 2 years (range, 0-31 years). A total of 6.7% of patients required emergency surgery within 5 years of diagnosis. In total, 8.8% of patients required emergency surgery within 15 years. The overall risk of surgical recurrence was 35.9%. The risk of major abdominal surgery significantly decreased between 2000 and 2009 when compared with the 1970 to 1979 period (OR = 0.49 (95% CI, 0.34-0.70). However, the rate of perianal surgery significantly increased (OR = 5.76 (95% CI, 2.54-13.06)). The main indications for surgery were enteric stricture or obstruction, perianal disease, and intra-abdominal fistulas/abscess. Of the 972 patients over 4 decades, only 11 patients (1.1%) were diagnosed with colorectal cancer. LIMITATIONS: This was a specialist-referred cohort, not a population-based study. CONCLUSIONS: The rate of major abdominal surgery has decreased, with surgery reserved for more severe and complicated disease. The natural history of patients with more complicated Crohn's disease and severe phenotypes puts them at higher risk of surgical recurrence and emergency surgery. There has been no reduction in emergency surgery rates and there has been an increase in surgical recurrence despite the reduction in surgical rate morbidity. See Video Abstract at http://links.lww.com/DCR/A483.


Assuntos
Canal Anal/cirurgia , Doença de Crohn/epidemiologia , Doença de Crohn/cirurgia , Procedimentos Cirúrgicos do Sistema Digestório/estatística & dados numéricos , Adolescente , Adulto , Austrália/epidemiologia , Procedimentos Cirúrgicos do Sistema Digestório/tendências , Procedimentos Cirúrgicos Eletivos/estatística & dados numéricos , Procedimentos Cirúrgicos Eletivos/tendências , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
10.
Molecules ; 23(9)2018 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-30223479

RESUMO

Saponification is the process in which triglycerides are combined with a strong base to form fatty acid metal salts during the soap-making process. The distribution of unsaturated and saturated fatty acid determines the hardness, aroma, cleansing, lather, and moisturizing abilities of soaps. Plant extracts, such as rosemary, vegetable, and essential oils are frequently added to soaps to enhance quality and sensory appeal. Three natural soaps were formulated using cold saponification to produce a base or control bar (BB), hibiscus rosehip bar (H), and a forest grove bar (FG). Rosemary extract (R) or essential oil (A) blends were added as additives to each formulation prior to curing to evaluate the effects of natural plant additives on the lipid composition and sensory characteristics of these natural herbal soaps. A total of seven natural soaps, three without additives (BB, H, FG) and four with additives (BBR, HA, FGR, FGA), were manufactured and studied. The majority (86⁻99%) of the polyunsaturated fatty acids (5.0⁻7.0 µg/mg) remained unsaponified in the manufactured natural soaps regardless of feedstock used. Principal component analysis (PCA) analyses showed the unsaponifiable fatty acids were different in the hibiscus bar compared to the other bars. There was a very strong correlation between the content of unsaponified C18:3n3 and C18:1n9 in all natural soaps. These results indicate that unsaponified fatty acids are important contributors to the quality and overall sensory perception and preference of natural herbal soaps following manufacturing by cold saponification.


Assuntos
Ácidos Graxos Insaturados/química , Óleos de Plantas/química , Sabões/síntese química , Estrutura Molecular , Óleos Voláteis/química , Óleos de Plantas/análise , Sabões/química
11.
Dis Colon Rectum ; 59(9): 878-85, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27505117

RESUMO

BACKGROUND: Sacral nerve stimulation is proposed as a treatment for slow-transit constipation. However, in our randomized controlled trial we found no therapeutic benefit over sham stimulation. These patients have now been followed-up over a long-term period. OBJECTIVE: The purpose of this study was to assess the long-term efficacy of sacral nerve stimulation in patients with scintigraphically confirmed slow-transit constipation. DESIGN: This study was designed for long-term follow-up of patients after completion of a randomized controlled trial. SETTINGS: It was conducted at an academic tertiary public hospital in Sydney. PATIENTS: Adults with slow-transit constipation were included. MAIN OUTCOME MEASURES: At the 1- and 2-year postrandomized controlled trial, the primary treatment outcome measure was the proportion of patients who reported a feeling of complete evacuation on >2 days per week for ≥2 of 3 weeks during stool diary assessment. Secondary outcome was demonstration of improved colonic transit at 1 year. RESULTS: Fifty-three patients entered long-term follow-up, and 1 patient died. Patient dissatisfaction or serious adverse events resulted in 44 patients withdrawing from the study because of treatment failure by the end of the second year. At 1 and 2 years, 10 (OR = 18.8% (95% CI, 8.3% to 29.3%)) and 3 patients (OR = 5.7% (95% CI, -0.5% to 11.9%)) met the primary outcome measure. Colonic isotope retention at 72 hours did not differ between baseline (OR = 75.6% (95% CI, 65.7%-85.6%)) and 1-year follow-up (OR = 61.7% (95% CI, 47.8%-75.6%)). LIMITATIONS: This study only assessed patients with slow-transit constipation. CONCLUSIONS: In these patients with slow-transit constipation, sacral nerve stimulation was not an effective treatment.


Assuntos
Constipação Intestinal/terapia , Terapia por Estimulação Elétrica/métodos , Trânsito Gastrointestinal , Plexo Lombossacral , Adolescente , Adulto , Idoso , Constipação Intestinal/fisiopatologia , Estudos Cross-Over , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
12.
Pharm Res ; 33(5): 1249-58, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26887680

RESUMO

PURPOSE: Typical methods to study pMDI sprays employ particle sizing or visible light diagnostics, which suffer in regions of high spray density. X-ray techniques can be applied to pharmaceutical sprays to obtain information unattainable by conventional particle sizing and light-based techniques. METHODS: We present a technique for obtaining quantitative measurements of spray density in pMDI sprays. A monochromatic focused X-ray beam was used to perform quantitative radiography measurements in the near-nozzle region and plume of HFA-propelled sprays. RESULTS: Measurements were obtained with a temporal resolution of 0.184 ms and spatial resolution of 5 µm. Steady flow conditions were reached after around 30 ms for the formulations examined with the spray device used. Spray evolution was affected by the inclusion of ethanol in the formulation and unaffected by the inclusion of 0.1% drug by weight. Estimation of the nozzle exit density showed that vapour is likely to dominate the flow leaving the inhaler nozzle during steady flow. CONCLUSIONS: Quantitative measurements in pMDI sprays allow the determination of nozzle exit conditions that are difficult to obtain experimentally by other means. Measurements of these nozzle exit conditions can improve understanding of the atomization mechanisms responsible for pMDI spray droplet and particle formation.


Assuntos
Propelentes de Aerossol/química , Broncodilatadores/administração & dosagem , Hidrocarbonetos Fluorados/química , Ipratrópio/administração & dosagem , Inaladores Dosimetrados , Desenho de Equipamento , Volatilização , Raios X
14.
Am J Gastroenterol ; 110(5): 733-40, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25895520

RESUMO

OBJECTIVES: Sacral nerve stimulation (SNS) is a potential treatment for constipation refractory to standard therapies. However, there have been no randomized controlled studies examining its efficacy. In patients with slow transit constipation, we evaluated the efficacy of suprasensory and subsensory SNS compared with sham, in a prospective, 18-week randomized, double-blind, placebo-controlled, two-phase crossover study. The primary outcome measure was the proportion of patients who, on more than 2 days/week for at least 2 of 3 weeks, reported a bowel movement associated with a feeling of complete evacuation. METHODS: After 3 weeks of temporary peripheral nerve evaluation (PNE), all patients had permanent implantation and were randomized to subsensory/sham (3 weeks each) and then re-randomized to suprasensory/sham (3 weeks each) with a 2-week washout period between each arm. Daily stool dairies were kept, and quality of life (QoL; SF36) was measured at the end of each arm. RESULTS: Between November 2006 and March 2012, 234 constipated patients were assessed, of whom 59 were willing and deemed eligible to participate (4 male; median age 42 years). Of the 59 patients, 16 (28%) responded to PNE. Fifty-five patients went on to permanent SNS implantation. The proportion of patients satisfying the primary outcome measure did not differ between suprasensory (30%) and sham (21%) stimulations, nor between subsensory (25%) and sham (25%) stimulations. There were no significant changes in QoL scores. CONCLUSIONS: In patients with refractory slow transit constipation, SNS did not improve the frequency of complete bowel movements over the 3-week active period.


Assuntos
Constipação Intestinal/fisiopatologia , Constipação Intestinal/terapia , Terapia por Estimulação Elétrica/métodos , Adulto , Idoso , Estudos Cross-Over , Defecação , Método Duplo-Cego , Terapia por Estimulação Elétrica/efeitos adversos , Feminino , Trânsito Gastrointestinal , Humanos , Neuroestimuladores Implantáveis , Plexo Lombossacral , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Limiar Sensorial , Adulto Jovem
15.
Drug Dev Ind Pharm ; 41(5): 825-37, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24738790

RESUMO

Intensive dry powder coating (mechanofusion) with tablet lubricants has previously been shown to give substantial powder flow improvement. This study explores whether the mechanofusion of magnesium stearate (MgSt), on a fine drug powder can substantially improve flow, without preventing the powder from being directly compacted into tablets. A fine ibuprofen powder, which is both cohesive and possesses a low-melting point, was dry coated via mechanofusion with between 0.1% and 5% (w/w) MgSt. Traditional low-shear blending was also employed as a comparison. No significant difference in particle size or shape was measured following mechanofusion. For the low-shear blended powders, only marginal improvement in flowability was obtained. However, after mechanofusion, substantial improvements in the flow properties were demonstrated. Both XPS and ToF-SIMS demonstrated high degrees of a nano-scale coating coverage of MgSt on the particle surfaces from optimized mechanofusion. The study showed that robust tablets were produced from the selected mechanofused powders, at high-dose concentration and tablet tensile strength was further optimized via addition of a Polyvinylpyrrolidone (PVP) binder (10% w/w). The tablets with the mechanofused powder (with or without PVP) also exhibited significantly lower ejection stress than those made of the raw powder, demonstrating good lubrication. Surprisingly, the release rate of drug from the tablets made with the mechanofused powder was not retarded. This is the first study to demonstrate such a single-step dry coating of model drug with MgSt, with promising flow improvement, flow-aid and lubrication effects, tabletability and also non-inhibited dissolution rate.


Assuntos
Excipientes/química , Ibuprofeno/administração & dosagem , Lubrificantes/química , Ácidos Esteáricos/química , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Ibuprofeno/química , Tamanho da Partícula , Povidona/química , Pós , Solubilidade , Comprimidos , Resistência à Tração
16.
Pharm Res ; 31(11): 2963-74, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24934661

RESUMO

PURPOSE: Non-volatile agents such as glycerol are being introduced into solution-based pMDI formulations in order to control mean precipitant droplet size. To assess their biopharmaceutical efficacy, both microscopic and macroscopic characteristics of the plume must be known, including the effects of external factors such as the flow generated by the patient's inhalation. We test the hypothesis that the macroscopic properties (e.g. spray geometry) of a pMDI spray can be predicted using a self-similarity model, avoiding the need for repeated testing. METHODS: Glycerol-containing and glycerol-free pMDI formulations with matched mass median aerodynamic diameters are investigated. High-speed schlieren imaging is used to extract time-resolved velocity, penetration and spreading angle measurements of the pMDI spray plume. The experimental data are used to validate the analytical model. RESULTS: The pMDI spray develops in a manner characteristic of a fully-developed steady turbulent jet, supporting the hypothesis. Equivalent glycerol-containing and non glycerol-containing formulations exhibit similar non-dimensional growth rates and follow a self-similar scaling behaviour over a range of physiologically relevant co-flow rates. CONCLUSIONS: Using the proposed model, the mean leading edge penetration, velocity and spreading rate of a pMDI spray may be estimated a priori for any co-flow conditions. The effects of different formulations are captured in two scaling constants. This allows formulators to predict the effects of variation between pMDIs without the need for repeated testing. Ultimately, this approach will allow pharmaceutical scientists to rapidly test a number of variables during pMDI development.


Assuntos
Aerossóis/química , Soluções Farmacêuticas/química , Tecnologia Farmacêutica/métodos , Administração por Inalação , Química Farmacêutica/métodos , Inaladores Dosimetrados , Tamanho da Partícula
17.
Artigo em Inglês | MEDLINE | ID: mdl-38976113

RESUMO

Eukaryotic cell rheology has important consequences for vital processes such as adhesion, migration, and differentiation. Experiments indicate that cell cytoplasm can exhibit both elastic and viscous characteristics in different regimes, while the transport of fluid (cytosol) through the cross-linked filamentous scaffold (cytoskeleton) is reminiscent of mass transfer by diffusion through a porous medium. To gain insights into this complex rheological behaviour, we construct a computational model for the cell cytoplasm as a poroviscoelastic material formulated on the principles of nonlinear continuum mechanics, where we model the cytoplasm as a porous viscoelastic scaffold with an embedded viscous fluid flowing between the pores to model the cytosol. Baseline simulations (neglecting the viscosity of the cytosol) indicate that the system exhibits seven different regimes across the parameter space spanned by the viscoelastic relaxation timescale of the cytoskeleton and the poroelastic diffusion timescale; these regimes agree qualitatively with experimental measurements. Furthermore, the theoretical model also allows us to elucidate the additional role of pore fluid viscosity, which enters the system as a distinct viscous timescale. We show that increasing this viscous timescale hinders the passage of the pore fluid (reducing the poroelastic diffusion) and makes the cytoplasm rheology increasingly incompressible, shifting the phase boundaries between the regimes.

18.
Ann Surg ; 257(5): 909-15, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23579542

RESUMO

OBJECTIVE: Prolonged ileus-the failure of postoperative ileus to resolve within a few days after major abdominal surgery-leads to significant medical consequences for the patient and costs to the hospital system. The aim of this retrospective analysis of prospectively collected data was to identify independent preoperative and intraoperative risk factors for prolonged ileus in a large consecutive series of patients who had undergone resection for colorectal cancer. METHODS: Patients were drawn from a hospital registry of 2400 consecutive resections over the period 1995-2009. Thirty-four potential predictors of prolonged ileus were analyzed by logistic regression. RESULTS: Prolonged ileus occurred in 14.0% of patients. Statistically significant independent predictors of prolonged ileus were male sex (OR: 1.7, P < 0.001), peripheral vascular disease (OR: 1.8, P < 0.001), respiratory comorbidity (OR: 1.6, P < 0.001), resection at urgent operation (OR: 2.2, P < 0.001), perioperative transfusion (OR: 1.6, P < 0.010), stoma constructed (OR: 1.4, P < 0.001), and operation lasting ≥3 hours (OR: 1.6, P < 0.001). CONCLUSIONS: These features can be used to alert medical and nursing staff to patients likely to experience prolonged ileus after bowel resection so that they can be monitored closely in the postoperative period and available treatments targeted toward them. These features may also be useful in the research context to facilitate the more efficient selection of high-risk patients as subjects in clinical trials of prevention or treatment.


Assuntos
Colectomia , Neoplasias Colorretais/cirurgia , Íleus/etiologia , Complicações Pós-Operatórias/etiologia , Reto/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Íleus/epidemiologia , Estimativa de Kaplan-Meier , Tempo de Internação/estatística & dados numéricos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
19.
AAPS PharmSciTech ; 14(1): 38-44, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23196863

RESUMO

The objective of this study was to investigate the effect of particle surface coating with magnesium stearate on the aerosolization of dry powder inhaler formulations. Micronized salbutamol sulphate as a model drug was dry coated with magnesium stearate using a mechanofusion technique. The coating quality was characterized by X-ray photoelectron spectroscopy. Powder bulk and flow properties were assessed by bulk densities and shear cell measurements. The aerosol performance was studied by laser diffraction and supported by a twin-stage impinger. High degrees of coating coverage were achieved after mechanofusion, as measured by X-ray photoelectron spectroscopy. Concomitant significant increases occurred in powder bulk densities and in aerosol performance after coating. The apparent optimum performance corresponded with using 2% w/w magnesium stearate. In contrast, traditional blending resulted in no significant changes in either bulk or aerosolization behaviour compared to the untreated sample. It is believed that conventional low-shear blending provides insufficient energy levels to expose host micronized particle surfaces from agglomerates and to distribute guest coating material effectively for coating. A simple ultra-high-shear mechanical dry powder coating step was shown as highly effective in producing ultra-thin coatings on micronized powders and to substantially improve the powder aerosolization efficiency.


Assuntos
Aerossóis , Inaladores de Pó Seco , Pós , Ácidos Esteáricos/química , Tamanho da Partícula , Espectroscopia Fotoeletrônica , Propriedades de Superfície
20.
Arch Clin Neuropsychol ; 38(4): 586-597, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36385276

RESUMO

OBJECTIVE: The Test of Visuospatial Construction (TVSC) was designed as an easily administered measure of non-motor visuoconstruction, though only preliminary data exists regarding the clinical utility of this task. The current study examined the diagnostic accuracy of the TVSC by comparing performance between healthy subjects and various clinical groups. The authors also wanted to determine whether previous findings could be replicated regarding its effectiveness at tracking cognitive decline. METHOD: Archival data collected over a period of more than 10 years were utilized and the overall sample consisted of 955 individuals, 372 healthy subjects, and 583 subjects who were categorized into various clinical groups. Only TVSC test data and demographic variables were utilized for statistical analyses in this study. RESULTS: The control group obtained significantly higher scores on the TVSC than the clinical groups. AUC values were indicative of excellent discrimination between cases and controls. Exploratory ROC curve analyses suggested adequate to excellent discrimination between the control group and the individual clinical groups as well as between the mild cognitive impairment (MCI) subgroups and the two dementia groups. CONCLUSIONS: This study demonstrates that the TVSC can effectively differentiate between healthy subjects and neurologically compromised individuals. Additionally, the TVSC may be able to measure the progressive decline in visuoconstructive abilities that occurs as patients traverse the spectrum of MCI and dementia.


Assuntos
Disfunção Cognitiva , Demência , Humanos , Testes Neuropsicológicos , Disfunção Cognitiva/diagnóstico , Curva ROC , Demência/diagnóstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA