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1.
Regul Toxicol Pharmacol ; 138: 105337, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36649819

RESUMEN

An expert panel was assembled to evaluate reproductive toxicology study data and their application to health risk assessment to provide input on the data quality, interpretation, and application of data from three multi-generation reproductive toxicity studies of N-methylpyrrolidone (NMP). Panelists were engaged using a double-blinded, modified Delphi format that consisted of three rounds. Key studies were scored using the U.S. Environmental Protection Agency's (EPA) questions and general considerations to guide the evaluation of experimental animal studies for systematic review. The primary conclusions of the panel are that one of the studies (Exxon, 1991) is not a high-quality study due to several design flaws that includes: (1) exceedance of the maximum tolerable dose in the high dose group; (2) failure to adjust feed concentrations of NMP during the lactation period, resulting in NMP doses that were 2- to 3-fold higher than nominal levels; and/or (3) underlying reproductive performance problems in the strain of rats used. For these reasons, the panel recommended that this study should not be considered for quantitative risk assessment of NMP. Exclusion of this study, and its corresponding data for male fertility and female fecundity, from the quantitative risk assessment results in a change in the identification of the most sensitive endpoint. Instead, changes in rat fetal/pup body weight, an endpoint previously selected by EPA, was identified as an appropriate basis for human health risk assessment based on a consideration of the best available science and weight of scientific evidence supported by the NMP toxicity database.


Asunto(s)
Pirrolidinonas , Reproducción , Humanos , Ratas , Masculino , Animales , Femenino , Pirrolidinonas/toxicidad , Peso Fetal , Medición de Riesgo
2.
Br J Cancer ; 124(9): 1540-1542, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33558706

RESUMEN

BACKGROUND: Combinations of inflammatory markers are used as prognostic scores in cancer patients with cachexia. We investigated whether they could also be used to prioritise patients attending primary care with unexpected weight loss for cancer investigation. METHODS: We used English primary care electronic health records data linked to cancer registry data from 12,024 patients with coded unexpected weight loss. For each individual inflammatory marker and score we estimated the sensitivity, specificity, likelihood ratios, positive predictive value (PPV) and the area under the curve along with 95% confidence intervals for a cancer diagnosis within six months. RESULTS: The risk of cancer associated with two abnormal inflammatory markers combined in a score was higher than the risk associated with individual inflammatory marker abnormalities. However, the risk of cancer in weight loss associated with individual abnormalities, notably a raised C-reactive protein, was sufficient to trigger further investigation for cancer under current NICE guidelines. CONCLUSIONS: If scores including pairs of inflammatory marker abnormalities were to be used, in preference to individual abnormalities, fewer people would be investigated to diagnose one cancer with fewer false positives, but fewer people with cancer would be diagnosed overall.


Asunto(s)
Biomarcadores/metabolismo , Mediadores de Inflamación/metabolismo , Inflamación/complicaciones , Neoplasias/diagnóstico , Atención Primaria de Salud/estadística & datos numéricos , Sistema de Registros/estadística & datos numéricos , Pérdida de Peso , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Registros Electrónicos de Salud , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/etiología , Pronóstico , Reino Unido/epidemiología , Adulto Joven
3.
Ann Behav Med ; 55(4): 298-307, 2021 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-32914832

RESUMEN

BACKGROUND: In August 2019, the U.S. Food and Drug Administration proposed a set of 13 new graphic warnings for cigarette packaging and advertisements. PURPOSE: We evaluated these warnings relative to text-only equivalents for their ability to educate the public regarding harms of smoking and influence outcomes associated with quitting. METHODS: In an experimental within-subjects design, U.S. adult nonsmokers, smokers, and dual smoker/electronic cigarette (e-cigarette) users (N = 412) recruited from an online internet platform evaluated the newly proposed graphic warnings and corresponding text-only warnings on understandability, perceived new knowledge, worry elicited about the content of the warning, discouragement from smoking, and encouragement to use e-cigarettes. RESULTS: Graphic warnings were generally rated as providing better understanding, more new knowledge, eliciting more worry about harms of smoking, and providing more discouragement from smoking relative to text-only warnings. CONCLUSIONS: The newly proposed graphic warnings could influence important responses to warnings associated with motivation to reduce smoking.


Asunto(s)
Comunicación en Salud/métodos , Etiquetado de Productos/métodos , Fumar/psicología , Productos de Tabaco/efectos adversos , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevención del Hábito de Fumar/métodos , Estados Unidos , United States Food and Drug Administration
4.
Br J Cancer ; 123(5): 722-729, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32624574

RESUMEN

BACKGROUND: Patients with non-specific symptoms often experience longer times to diagnosis and poorer clinical outcomes than those with site-specific symptoms. This paper reports initial results from five multidisciplinary diagnostic centre (MDC) projects in England, piloting rapid referral for patients with non-specific symptoms. METHODS: The evaluation covered MDC activity from 1st December 2016 to 31st July 2018, with projects using a common dataset. Logistical regression analyses were conducted, with a diagnosis of any cancer as the dependent variable. Exploratory analysis was conducted on presenting symptoms and diagnoses of cancer, and on comparisons within these groupings. RESULTS: In total, 2961 patients were referred into the MDCs and 241 cancers were diagnosed. The pathway detected cancers across a broad range of tumour sites, including several rare and less common cancers. An association between patient age and cancer was identified (p < 0.001). GP 'clinical suspicion' was identified as a strong predictor of cancer (p = 0.006), with a reduced association with cancer observed in patients with higher numbers of GP consultation before referral (p = 0.008). CONCLUSIONS: The MDC model diagnoses cancer in patients with non-specific symptoms, with a conversion rate of 8%, demonstrating the diagnostic potential of a non-site-specific symptomatic referral pathway.


Asunto(s)
Neoplasias/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Detección Precoz del Cáncer/métodos , Femenino , Humanos , Comunicación Interdisciplinaria , Masculino , Persona de Mediana Edad , Grupo de Atención al Paciente , Derivación y Consulta
5.
BMC Med ; 17(1): 222, 2019 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-31783757

RESUMEN

BACKGROUND: Excess weight and unexpected weight loss are associated with multiple disease states and increased morbidity and mortality, but weight measurement is not routine in many primary care settings. The aim of this study was to characterise who has had their weight recorded in UK primary care, how frequently, by whom and in relation to which clinical events, symptoms and diagnoses. METHODS: A longitudinal analysis of UK primary care electronic health records (EHR) data from 2000 to 2017. Descriptive statistics were used to summarise weight recording in terms of patient sociodemographic characteristics, health professional encounters, clinical events, symptoms and diagnoses. Negative binomial regression was used to model the likelihood of having a weight record each year, and Cox regression to the likelihood of repeated weight recording. RESULTS: A total of 14,049,871 weight records were identified in the EHR of 4,918,746 patients during the study period, representing 26,998,591 person-years of observation. Around a third of patients had a weight record each year. Forty-nine percent of weight records were repeated within a year with an average time to a repeat weight record of 1.92 years. Weight records were most often taken by nursing staff (38-42%) and GPs (37-39%) as part of a routine clinical care, such as chronic disease reviews (16%), medication reviews (6-8%) and health checks (6-7%), or were associated with consultations for contraception (5-8%), respiratory disease (5%) and obesity (1%). Patient characteristics independently associated with an increased likelihood of weight recording were as follows: female sex, younger and older adults, non-drinkers, ex-smokers, low or high BMI, being more deprived, diagnosed with a greater number of comorbidities and consulting more frequently. The effect of policy-level incentives to record weight did not appear to be sustained after they were removed. CONCLUSION: Weight recording is not a routine activity in UK primary care. It is recorded for around a third of patients each year and is repeated on average every 2 years for these patients. It is more common in females with higher BMI and in those with comorbidity. Incentive payments and their removal appear to be associated with increases and decreases in weight recording.


Asunto(s)
Trayectoria del Peso Corporal , Registros Electrónicos de Salud/estadística & datos numéricos , Adulto , Comorbilidad , Femenino , Historia del Siglo XXI , Humanos , Estudios Longitudinales , Masculino , Atención Primaria de Salud/estadística & datos numéricos , Reino Unido
6.
Rapid Commun Mass Spectrom ; 33(15): 1258-1266, 2019 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-30993809

RESUMEN

RATIONALE: The use of multi-isotopic analysis (δ15 N, δ13 C and δ34 S values) of archaeological bone collagen to assist in the interpretation of diet, movement and mobility of prehistoric populations is gradually increasing, yet many researchers have traditionally avoided investigating sulphur due to its very low concentrations (<0.3%) in mammalian collagen. For this reason, and as a consequence of analytical detection limits, sulphur is usually measured separately from carbon and nitrogen, which leads to longer analytical times and higher costs. METHODS: A Thermo Scientific™ EA IsoLink™ isotope ratio mass spectrometry (IRMS) system, with the ability to rapidly heat a gas chromatography (GC) column and concentrate the sample gas online without cryo-trapping, was used at the Radiocarbon Laboratory at the Scottish Universities Environmental Research Centre (SUERC). Optimisation of the GC temperature and carrier gas flow rate in the elemental analyser resulted in improved signal-to-noise (S/N) ratio and sensitivity for SO2 . This allowed for routine sequential N2 , CO2 and SO2 measurements on small samples of bone collagen. RESULTS: Improvements in sample gas transfer to the mass spectrometer allows for sequential δ15 N, δ13 C and δ34 S values to be measured in 1-1.5 mg samples of bone collagen. Moreover, the sensitivity and S/N ratio of the sample gas, especially SO2 , is improved, resulting in precisions of ±0.15‰ for δ15 N values, ±0.1‰ for δ13 C values and ±0.3‰ for δ34 S values. Previous instrumentation allowed for the analysis of ~30 unknown samples before undertaking maintenance; however, ~150 unknown samples can now be measured, meaning a 5-fold increase in sample throughput. CONCLUSIONS: The ability to sequentially measure δ15 N, δ13 C and δ34 S values rapidly in archaeological bone collagen is an attractive option to researchers who want to build larger, more succinct datasets for their sites of interest, at a much-reduced analytical cost and without destroying larger quantities of archaeological material.


Asunto(s)
Arqueología/métodos , Huesos/química , Isótopos de Carbono/análisis , Colágeno/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Isótopos de Nitrógeno/análisis , Isótopos de Azufre/análisis , Animales , Escocia , Universidades
7.
BMC Fam Pract ; 20(1): 118, 2019 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-31431191

RESUMEN

BACKGROUND: Brain tumour patients see their primary care doctor on average three or more times before diagnosis, so there may be an opportunity to identify 'at risk' patients earlier. Suspecting a brain tumour diagnosis is difficult because brain tumour-related symptoms are typically non-specific. METHODS: We explored the predictive value of referral guidelines (Kernick and NICE 2005) for brain imaging where a tumour is suspected, in a population-based patient group referred for direct access CT of the head. A consensus panel reviewed whether non-tumour findings were clinically important or whether further investigation was necessary. RESULTS: Over a 5-year period, 3257 head scans were performed; 318 scans were excluded according to pre-specified criteria. 53 patients (1.8%) were reported to have intracranial tumours, of which 42 were significant (diagnostic yield of 1.43%). There were no false negative CT scans for tumour. With symptom-based referral guidelines primary care doctors can identify patients with a 3% positive predictive value (PPV). 559 patients had non-tumour findings, 31% of which were deemed clinically significant. In 34% of these 559 patients, referral for further imaging and/or specialist assessment from primary care was still thought warranted. CONCLUSION: Existing referral guidelines are insufficient to stratify patients adequately based on their symptoms, according to the likelihood that a tumour will be found on brain imaging. Identification of non-tumour findings may be significant for patients and earlier specialist input into interpretation of these images may be beneficial. Improving guidelines to better identify patients at risk of a brain tumour should be a priority, to improve speed of diagnosis, and reduce unnecessary imaging and costs. Future guidelines may incorporate groups of symptoms, clinical signs and tests to improve the predictive value.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Neuroimagen , Derivación y Consulta , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Derivación y Consulta/organización & administración , Derivación y Consulta/normas , Adulto Joven
8.
Soc Cogn ; 37(3): 314-340, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33828353

RESUMEN

Widespread messages use metaphoric language and imagery to prompt recipients to interpret health-related concepts in terms of dissimilar, familiar concepts (e.g., "fight the war on cancer"). When do these messages work? According to Conceptual Metaphor Theory, thinking metaphorically involves looking past concepts' superficial differences to identify their similarities at a structural level. Thus, we hypothesized that when people's general construal mindset is oriented to focus on information's abstract meaning, not its concrete details, they would process a metaphor's target health concept in ways that correspond to the dissimilar concept. Accordingly, after priming an abstract, but not concrete, construal mindset: framing sun exposure as enemy confrontation (vs. literally) increased cancer risk perceptions and sun-safe intentions (Study 1; N=186); and framing smoking cessation as an arduous journey (vs. literally) increased appreciation of quitting difficulties and interest in cessation tools (Study 2; N=244). We discuss practical and theoretical implications for improving health communication.

9.
Br J Cancer ; 118(1): 24-31, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29182609

RESUMEN

BACKGROUND: In England, 'fast-track' (also known as 'two-week wait') general practitioner referrals for suspected cancer in symptomatic patients are used to shorten diagnostic intervals and are supported by clinical guidelines. However, the use of the fast-track pathway may vary for different patient groups. METHODS: We examined data from 669 220 patients with 35 cancers diagnosed in 2006-2010 following either fast-track or 'routine' primary-to-secondary care referrals using 'Routes to Diagnosis' data. We estimated the proportion of fast-track referrals by sociodemographic characteristic and cancer site and used logistic regression to estimate respective crude and adjusted odds ratios. We additionally explored whether sociodemographic associations varied by cancer. RESULTS: There were large variations in the odds of fast-track referral by cancer (P<0.001). Patients with testicular and breast cancer were most likely to have been diagnosed after a fast-track referral (adjusted odds ratios 2.73 and 2.35, respectively, using rectal cancer as reference); whereas patients with brain cancer and leukaemias least likely (adjusted odds ratios 0.05 and 0.09, respectively, for brain cancer and acute myeloid leukaemia). There were sex, age and deprivation differences in the odds of fast-track referral (P<0.013) that varied in their size and direction for patients with different cancers (P<0.001). For example, fast-track referrals were least likely in younger women with endometrial cancer and in older men with testicular cancer. CONCLUSIONS: Fast-track referrals are less likely for cancers characterised by nonspecific presenting symptoms and patients belonging to low cancer incidence demographic groups. Interventions beyond clinical guidelines for 'alarm' symptoms are needed to improve diagnostic timeliness.


Asunto(s)
Neoplasias/clasificación , Neoplasias/diagnóstico , Derivación y Consulta , Factores de Edad , Detección Precoz del Cáncer , Medicina Basada en la Evidencia , Femenino , Humanos , Masculino , Oportunidad Relativa , Análisis de Regresión , Factores Sexuales
10.
Br J Cancer ; 117(6): 888-897, 2017 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-28787432

RESUMEN

BACKGROUND: The benefits from expedited diagnosis of symptomatic cancer are uncertain. We aimed to analyse the relationship between stage of colorectal cancer (CRC) and the primary and specialist care components of the diagnostic interval. METHODS: We identified seven independent data sets from population-based studies in Scotland, England, Canada, Denmark and Spain during 1997-2010 with a total of 11 720 newly diagnosed CRC patients, who had initially presented with symptoms to a primary care physician. Data were extracted from patient records, registries, audits and questionnaires, respectively. Data sets were required to hold information on dates in the diagnostic interval (defined as the time from the first presentation of symptoms in primary care until the date of diagnosis), symptoms at first presentation in primary care, route of referral, gender, age and histologically confirmed stage. We carried out reanalysis of all individual data sets and, using the same method, analysed a pooled individual patient data set. RESULTS: The association between intervals and stage was similar in the individual and combined data set. There was a statistically significant convex (∩-shaped) association between primary care interval and diagnosis of advanced (i.e., distant or regional) rather than localised CRC (P=0.004), with odds beginning to increase from the first day on and peaking at 90 days. For specialist care, we saw an opposite and statistically significant concave (∪-shaped) association, with a trough at 60 days, between the interval and diagnosis of advanced CRC (P<0.001). CONCLUSIONS: This study provides evidence that longer diagnostic intervals are associated with more advanced CRC. Furthermore, the study cannot define a specific 'safe' waiting time as the length of the primary care interval appears to have negative impact from day one.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/patología , Diagnóstico Tardío , Detección Precoz del Cáncer , Atención Primaria de Salud , Adulto , Anciano , Anciano de 80 o más Años , Canadá , Estudios de Cohortes , Conjuntos de Datos como Asunto , Dinamarca , Inglaterra , Femenino , Humanos , Masculino , Persona de Mediana Edad , Derivación y Consulta , Escocia , España , Evaluación de Síntomas , Factores de Tiempo
11.
Artículo en Inglés | MEDLINE | ID: mdl-28474381

RESUMEN

There are approximately 3,000 new UK diagnoses of cervical cancer annually, with many women presenting symptomatically. We aimed to identify and quantify features of cervical cancer in primary care in a case-control study in the UK. Putative features of cervical cancer were identified, and odd ratios and positive predictive values (PPVs) were calculated. About 1,006 women aged ≥40 years diagnosed with cervical cancer and 4,992 age-, sex- and practice-matched controls were selected from the Clinical Practice Research Datalink. Median age at diagnosis was 61 years (interquartile range 51-75). Seven symptoms and two abnormal investigations were associated with cervical cancer: post-menopausal bleeding, odds ratio 43 (95% confidence interval 25, 75); vaginal discharge or vaginitis 8.8 (5.2, 15), intermenstrual bleeding 4.7 (1.6, 14); haematuria 4.6 (2.1, 10); irregular menstruation 3.8 (1.6, 9.0); urinary tract infection 1.9 (1.3, 2.8); abdominal pain 1.8 (1.4, 2.5); high white cell count 5.1 (2.9, 8.8) and low haemoglobin 2.6 (1.8, 3.8): all p < .005. The PPV of cervical cancer in women aged ≥55 with post-menopausal bleeding was 4.6% (2.5, 8.3). Other than for post-menopausal bleeding no symptom is high risk. Some symptoms, particularly haematuria, may be helpful. The primary care clinician must consider the unlikely diagnosis when the likely diagnosis does not settle with treatment.


Asunto(s)
Neoplasias del Cuello Uterino/epidemiología , Dolor Abdominal/etiología , Adulto , Edad de Inicio , Anciano , Estudios de Casos y Controles , Diagnóstico Diferencial , Detección Precoz del Cáncer , Registros Electrónicos de Salud , Inglaterra/epidemiología , Femenino , Hematuria/etiología , Hemoglobinopatías/etiología , Humanos , Recuento de Leucocitos , Trastornos de la Menstruación/etiología , Persona de Mediana Edad , Factores de Riesgo , Infecciones Urinarias/etiología , Neoplasias del Cuello Uterino/complicaciones , Neoplasias del Cuello Uterino/diagnóstico , Enfermedades Vaginales/etiología
12.
Mol Vis ; 22: 1468-1489, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28050121

RESUMEN

PURPOSE: Studies of neuronal development in the retina often examine the stages of proliferation, differentiation, and synaptic development, albeit independently. Our goal was to determine if a known neurotoxicant insult to a population of retinal progenitor cells (RPCs) would affect their eventual differentiation and synaptic development. To that end, we used our previously published human equivalent murine model of low-level gestational lead exposure (GLE). Children and animals with GLE exhibit increased scotopic electroretinogram a- and b-waves. Adult mice with GLE exhibit an increased number of late-born RPCs, a prolonged period of RPC proliferation, and an increased number of late-born rod photoreceptors and rod and cone bipolar cells (BCs), with no change in the number of late-born Müller glial cells or early-born neurons. The specific aims of this study were to determine whether increased and prolonged RPC proliferation alters the spatiotemporal differentiation and synaptic development of rods and BCs in early postnatal GLE retinas compared to control retinas. METHODS: C57BL/6N mouse pups were exposed to lead acetate via drinking water throughout gestation and until postnatal day 10, which is equivalent to the human gestation period for retinal neurogenesis. RT-qPCR, immunohistochemical analysis, and western blots of well-characterized, cell-specific genes and proteins were performed at embryonic and early postnatal ages to assess rod and cone photoreceptor differentiation, rod and BC differentiation and synaptic development, and Müller glial cell differentiation. RESULTS: Real-time quantitative PCR (RT-qPCR) with the rod-specific transcription factors Nrl, Nr2e3, and Crx and the rod-specific functional gene Rho, along with central retinal confocal studies with anti-recoverin and anti-rhodopsin antibodies, revealed a two-day delay in the differentiation of rod photoreceptors in GLE retinas. Rhodopsin immunoblots supported this conclusion. No changes in glutamine synthetase gene or protein expression, a marker for late-born Müller glial cells, were observed in the developing retinas. In the retinas from the GLE mice, anti-PKCα, -Chx10 (Vsx2) and -secretagogin antibodies revealed a two- to three-day delay in the differentiation of rod and cone BCs, whereas the expression of the proneural and BC genes Otx2 and Chx10, respectively, increased. In addition, confocal studies of proteins associated with functional synapses (e.g., vesicular glutamate transporter 1 [VGluT1], plasma membrane calcium ATPase [PMCA], transient receptor potential channel M1 [TRPM1], and synaptic vesicle glycoprotein 2B [SV2B]) revealed a two-day delay in the formation of the outer and inner plexiform layers of the GLE retinas. Moreover, several markers revealed that the initiation of the differentiation and intensity of the labeling of early-born cells in the retinal ganglion cell and inner plexiform layers were not different in the control retinas. CONCLUSIONS: Our combined gene, confocal, and immunoblot findings revealed that the onset of rod and BC differentiation and their subsequent synaptic development is delayed by two to three days in GLE retinas. These results suggest that perturbations during the early proliferative stages of late-born RPCs fated to be rods and BCs ultimately alter the coordinated time-dependent progression of rod and BC differentiation and synaptic development. These GLE effects were selective for late-born neurons. Although the molecular mechanisms are unknown, alterations in soluble neurotrophic factors and/or their receptors are likely to play a role. Since neurodevelopmental delays and altered synaptic connectivity are associated with neuropsychiatric and behavioral disorders as well as cognitive deficits, future work is needed to determine if similar effects occur in the brains of GLE mice and whether children with GLE experience similar delays in retinal and brain neuronal differentiation and synaptic development.


Asunto(s)
Diferenciación Celular , Plomo/toxicidad , Neurogénesis , Efectos Tardíos de la Exposición Prenatal/patología , Células Bipolares de la Retina/patología , Células Fotorreceptoras Retinianas Bastones/patología , Envejecimiento/metabolismo , Animales , Biomarcadores/metabolismo , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Dendritas/efectos de los fármacos , Dendritas/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Glutamato-Amoníaco Ligasa/metabolismo , Ratones Endogámicos C57BL , Neurogénesis/efectos de los fármacos , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Embarazo , Efectos Tardíos de la Exposición Prenatal/metabolismo , Ratas Sprague-Dawley , Células Bipolares de la Retina/efectos de los fármacos , Células Fotorreceptoras Retinianas Bastones/efectos de los fármacos , Rodopsina/metabolismo , Sinapsis/efectos de los fármacos , Sinapsis/metabolismo
13.
Soft Matter ; 12(21): 4709-14, 2016 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-27021920

RESUMEN

Stöber silica particles are used in a diverse range of applications. Despite their widespread industrial and scientific uses, information on the internal structure of the particles is non-trivial to obtain and is not often reported. In this work we have used spin-echo small angle neutron scattering (SESANS) in conjunction with ultra small angle X-ray scattering (USAXS) and pycnometry to study an aqueous dispersion of Stöber particles. Our results are in agreement with models which propose that Stöber particles have a porous core, with a significant fraction of the pores inaccessible to solvent. For samples prepared from the same master sample in a range of H2O : D2O ratio solutions we were able to model the SESANS results for the solution series assuming monodisperse, smooth surfaced spheres of radius 83 nm with an internal open pore volume fraction of 32% and a closed pore fraction of 10%. Our results are consistent with USAXS measurements. The protocol developed and discussed here shows that the SESANS technique is a powerful way to investigate particles much larger than those studied using conventional small angle scattering methods.

14.
Am J Phys Anthropol ; 160(1): 126-36, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26799531

RESUMEN

OBJECTIVES: A previous multi-isotope study of archaeological faunal samples from Skútustaðir, an early Viking age settlement on the southern shores of Lake Mývatn in north-east Iceland, demonstrated that there are clear differences in δ(34)S stable isotope values between animals deriving their dietary protein from terrestrial, freshwater, and marine reservoirs. The aim of this study was to use this information to more accurately determine the diet of humans excavated from a nearby late Viking age churchyard. MATERIALS AND METHODS: δ(13)C, δ(15)N, and δ(34)S analyses were undertaken on terrestrial animal (n = 39) and human (n = 46) bone collagen from Hofstaðir, a high-status Viking-period farmstead ∼10 km north-west of Skútustaðir. RESULTS: δ(34)S values for Hofstaðir herbivores were ∼6‰ higher relative to those from Skútustaðir (δ(34)S: 11.4 ± 2.3‰ versus 5.6 ± 2.8‰), while human δ(13)C, δ(15)N, and δ(34)S values were broad ranging (-20.2‰ to -17.3‰, 7.4‰ to 12.3‰, and 5.5‰ to 14.9‰, respectively). DISCUSSION: Results suggest that the baseline δ(34)S value for the Mývatn region is higher than previously predicted due to a possible sea-spray effect, but the massive deposition of Tanytarsus gracilentus (midges) (δ(34)S: -3.9‰) in the soil in the immediate vicinity of the lake is potentially lowering this value. Several terrestrial herbivores displayed higher bone collagen δ(34)S values than their contemporaries, suggesting trade and/or movement of animals to the region from coastal areas. Broad ranging δ(13)C, δ(15)N, and δ(34)S values for humans suggest the population were consuming varied diets, while outliers within the dataset could conceivably have been migrants to the area.


Asunto(s)
Dieta Paleolítica/historia , Conducta Alimentaria/fisiología , Migración Humana/historia , Animales , Antropología Física , Huesos/química , Colágeno/química , Historia Antigua , Humanos , Islandia , Isótopos/análisis , Diente/química
15.
Cytopathology ; 27(3): 201-9, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26126636

RESUMEN

OBJECTIVE: To assess the sensitivity, the number needed to screen (NNS) and the positive predictive value (PPV) of cervical cytology for the diagnosis of cancer by age in a screening population. METHODS: A retrospective cohort of women with invasive cervical cancer nested within a census of cervical cytology. All (c. 8 million) women aged 20-64 years with cervical cytology (excluding tests after an earlier abnormality). From April 2007 to March 2010, 3372 women had cervical cancer diagnosed within 12 months of such cytology in England. The sensitivity of cervical cytology to cancer, NNS to detect one cancer and predictive values of cytology were calculated for various 'referral' thresholds. These were calculated for ages 20-24, 25-34, 35-49 and 50-64 years. RESULTS: The sensitivity of at least moderate dyskaryosis [equivalent to a high-grade squamous intraepithelial lesion (HSIL) or worse] for cancer of 89.4% [95% confidence interval (CI) 88.3-90.4%] in women offered screening was independent of age. At all ages, women with borderline-early recall or mild dyskaryosis on cytology (equivalent to ASC-US and LSIL, respectively, in the Bethesda system) had a similar risk of cervical cancer to the risk in all women tested. The PPV of severe dyskaryosis/?invasive and ?glandular neoplasia cytology (equivalent to squamous cell carcinoma and adenocarcinoma/adenocarcinoma in situ, respectively, in the Bethesda System) were 34% and 12%, respectively; the PPV of severe dyskaryosis (HSIL: severe dysplasia) was 4%. The NNS was lowest when the incidence of cervical cancer was highest, at ages 25-39 years, but the proportion of those with abnormal cytology who have cancer was also lowest in younger women. CONCLUSIONS: The PPV of at least severe dyskaryosis (HSIL: severe dysplasia) for cancer was 4-10% of women aged 25-64 years, justifying a 2-week referral to colposcopy and demonstrating the importance of failsafe monitoring for such patients. The sensitivity of cytology for cervical cancer was excellent across all age groups.


Asunto(s)
Células Escamosas Atípicas del Cuello del Útero/patología , Cuello del Útero/patología , Citodiagnóstico/métodos , Lesiones Intraepiteliales Escamosas de Cuello Uterino/diagnóstico , Displasia del Cuello del Útero/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Colposcopía , Detección Precoz del Cáncer , Femenino , Humanos , Persona de Mediana Edad , Prueba de Papanicolaou , Estudios Retrospectivos , Sensibilidad y Especificidad , Lesiones Intraepiteliales Escamosas de Cuello Uterino/patología , Neoplasias del Cuello Uterino/patología , Frotis Vaginal , Adulto Joven , Displasia del Cuello del Útero/patología
16.
Br J Cancer ; 112(2): 271-7, 2015 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-25461802

RESUMEN

BACKGROUND: Individuals with undiagnosed lung and colorectal cancers present with non-specific symptoms in primary care more often than matched controls. Increased access to diagnostic services for patients with symptoms generates more early-stage diagnoses, but the mechanisms for this are only partially understood. METHODS: We re-analysed a UK-based case-control study to estimate the Symptom Lead Time (SLT) distribution for a range of potential symptom criteria for investigation. Symptom Lead Time is the time between symptoms caused by cancer and eventual diagnosis, and is analogous to Lead Time in a screening programme. We also estimated the proportion of symptoms in lung and colorectal cancer cases that are actually caused by the cancer. RESULTS: Mean Symptom Lead Times were between 4.1 and 6.0 months, with medians between 2.0 and 3.2 months. Symptom Lead Time did not depend on stage at diagnosis, nor which criteria for investigation are adopted. Depending on the criteria, an estimated 27-48% of symptoms in individuals with as yet undiagnosed lung cancer, and 12-32% with undiagnosed colorectal cancer are not caused by the cancer. CONCLUSIONS: In most cancer cases detected by a symptom-based programme, the symptoms are caused by cancer. These cases have a short lead time and benefit relatively little. However, in a significant minority of cases cancer detection is serendipitous. This group experiences the benefits of a standard screening programme, a substantial mean lead time and a higher probability of early-stage diagnosis.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Neoplasias Pulmonares/diagnóstico , Estudios de Casos y Controles , Neoplasias Colorrectales/epidemiología , Detección Precoz del Cáncer , Humanos , Incidencia , Neoplasias Pulmonares/epidemiología , Atención Primaria de Salud , Sensibilidad y Especificidad
17.
Br J Cancer ; 112 Suppl 1: S70-6, 2015 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-25734384

RESUMEN

BACKGROUND: We report the findings of a feasibility study using information technology to search electronic primary care records and to identify patients with possible colorectal cancer. METHODS: An algorithm to flag up patients meeting National Institute for Health and Care Excellence (NICE) urgent referral criteria for suspected colorectal cancer was developed and incorporated into clinical audit software. This periodically flagged up such patients aged 60 to 79 years. General practitioners (GPs) reviewed flagged-up patients and decided on further clinical management. We report the numbers of patients identified and the numbers that GPs judged to need further review, investigations or referral to secondary care and the final diagnoses. RESULTS: Between January 2012 and March 2014, 19,580 records of patients aged 60 to 79 years were searched in 20 UK general practices, flagging up 809 patients who met urgent referral criteria. The majority of the patients had microcytic anaemia (236 (29%)) or rectal bleeding (205 (25%)). A total of 274 (34%) patients needed further clinical review of their records; 199 (73%) of these were invited for GP consultation, and 116 attended, of whom 42 were referred to secondary care. Colon cancer was diagnosed in 10 out of 809 (1.2%) flagged-up patients and polyps in a further 28 out of 809 (3.5%). CONCLUSIONS: It is technically possible to identify patients with colorectal cancer by searching electronic patient records.


Asunto(s)
Algoritmos , Carcinoma/diagnóstico , Neoplasias Colorrectales/diagnóstico , Registros Electrónicos de Salud , Pólipos Intestinales/diagnóstico , Informática Médica/métodos , Atención Primaria de Salud , Derivación y Consulta , Anciano , Anemia/etiología , Carcinoma/complicaciones , Neoplasias Colorrectales/complicaciones , Diarrea/etiología , Estudios de Factibilidad , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Pólipos Intestinales/complicaciones , Masculino , Auditoría Médica , Persona de Mediana Edad , Recto , Programas Informáticos
18.
Br J Cancer ; 112 Suppl 1: S6-13, 2015 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-25734397

RESUMEN

BACKGROUND: This prospective cohort study aimed to identify symptom and patient factors that influence time to lung cancer diagnosis and stage at diagnosis. METHODS: Data relating to symptoms were collected from patients upon referral with symptoms suspicious of lung cancer in two English regions; we also examined primary care and hospital records for diagnostic routes and diagnoses. Descriptive and regression analyses were used to investigate associations between symptoms and patient factors with diagnostic intervals and stage. RESULTS: Among 963 participants, 15.9% were diagnosed with primary lung cancer, 5.9% with other thoracic malignancies and 78.2% with non-malignant conditions. Only half the cohort had an isolated first symptom (475, 49.3%); synchronous first symptoms were common. Haemoptysis, reported by 21.6% of cases, was the only initial symptom associated with cancer. Diagnostic intervals were shorter for cancer than non-cancer diagnoses (91 vs 124 days, P=0.037) and for late-stage than early-stage cancer (106 vs 168 days, P=0.02). Chest/shoulder pain was the only first symptom with a shorter diagnostic interval for cancer compared with non-cancer diagnoses (P=0.003). CONCLUSIONS: Haemoptysis is the strongest symptom predictor of lung cancer but occurs in only a fifth of patients. Programmes for expediting earlier diagnosis need to focus on multiple symptoms and their evolution.


Asunto(s)
Carcinoma/diagnóstico , Neoplasias Pulmonares/diagnóstico , Neoplasias Torácicas/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma/complicaciones , Carcinoma/patología , Dolor en el Pecho/etiología , Estudios de Cohortes , Tos/etiología , Diagnóstico Tardío , Disnea/etiología , Inglaterra , Femenino , Hemoptisis/etiología , Humanos , Enfermedades Pulmonares/complicaciones , Enfermedades Pulmonares/diagnóstico , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Factores de Riesgo , Dolor de Hombro/etiología , Neoplasias Torácicas/complicaciones , Factores de Tiempo
19.
Br J Cancer ; 112 Suppl 1: S92-107, 2015 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-25734382

RESUMEN

BACKGROUND: It is unclear whether more timely cancer diagnosis brings favourable outcomes, with much of the previous evidence, in some cancers, being equivocal. We set out to determine whether there is an association between time to diagnosis, treatment and clinical outcomes, across all cancers for symptomatic presentations. METHODS: Systematic review of the literature and narrative synthesis. RESULTS: We included 177 articles reporting 209 studies. These studies varied in study design, the time intervals assessed and the outcomes reported. Study quality was variable, with a small number of higher-quality studies. Heterogeneity precluded definitive findings. The cancers with more reports of an association between shorter times to diagnosis and more favourable outcomes were breast, colorectal, head and neck, testicular and melanoma. CONCLUSIONS: This is the first review encompassing many cancer types, and we have demonstrated those cancers in which more evidence of an association between shorter times to diagnosis and more favourable outcomes exists, and where it is lacking. We believe that it is reasonable to assume that efforts to expedite the diagnosis of symptomatic cancer are likely to have benefits for patients in terms of improved survival, earlier-stage diagnosis and improved quality of life, although these benefits vary between cancers.


Asunto(s)
Diagnóstico Tardío/estadística & datos numéricos , Neoplasias , Tiempo de Tratamiento/estadística & datos numéricos , Humanos , Neoplasias/diagnóstico , Neoplasias/terapia , Pronóstico
20.
Ergonomics ; 58(4): 615-34, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25761155

RESUMEN

How do communications and decisions impact the safety of sociotechnical systems? This paper frames this question in the context of a dynamic system of nested sub-systems. Communications are related to the construct of observability (i.e. how components integrate information to assess the state with respect to local and global constraints). Decisions are related to the construct of controllability (i.e. how component sub-systems act to meet local and global safety goals). The safety dynamics of sociotechnical systems are evaluated as a function of the coupling between observability and controllability across multiple closed-loop components. Two very different domains (nuclear power and the limited service food industry) provide examples to illustrate how this framework might be applied. While the dynamical systems framework does not offer simple prescriptions for achieving safety, it does provide guides for exploring specific systems to consider the potential fit between organisational structures and work demands, and for generalising across different systems regarding how safety can be managed. PRACTITIONER SUMMARY: While offering no simple prescriptions about how to achieve safety in sociotechnical systems, this paper develops a theoretical framework based on dynamical systems theory as a practical guide for generalising from basic research to work domains and for generalising across alternative work domains to better understand how patterns of communication and decision-making impact system safety.


Asunto(s)
Comunicación , Toma de Decisiones , Seguridad , Análisis de Sistemas , Teoría de Sistemas , Humanos
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