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INTRODUCTION: Inefficiencies in the trauma setting are well known and have been further exacerbated by the COVID-19 pandemic among other factors, resulting in national guidance to aid improvements in resource utilisation. This study introduced a novel surgeon-led intervention, a trauma bed in recovery, with the aim of improving trauma theatre efficiency. METHODS: This quality improvement project was conducted using a Plan Do Study Act (PDSA) methodology and comprised multiple cycles to assess theatre performance. A multidisciplinary team (MDT) approach with relevant stakeholder input enabled intervention implementation, aimed at facilitating 'golden patient' arrival in the anaesthetic room as early as possible. The primary outcome was the time at which the first patient entered the anaesthetic room, and the secondary outcome was the number of cases performed each day. RESULTS: The study period was 1 year and encompassed three PDSA cycles. The intervention achieved its primary outcome by PDSA cycle 1 and its secondary outcome by PDSA cycle 2, demonstrating statistically significantly improved results (p < 0.001). A subanalysis assessed the specific impact of the intervention, and demonstrated a significant improvement in both outcomes when the intervention was used as intended (p < 0.0005). CONCLUSIONS: A ringfenced trauma bed significantly improved theatre start times and thereby theatre efficiency. This is a simple, pragmatic intervention that benefitted the MDT trauma team while also demonstrating a sustained impact. Given that National Health Service efficiency is at the forefront of national healthcare discourse, we recommend that this intervention is implemented in other trauma units to help provide a solution to this longstanding issue.
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INTRODUCTION: Stage of pancreatic carcinoma at diagnosis is a strong prognostic indicator of morbidity and mortality, yet is poorly notified to population-based cancer registries ("cancer registries"). Registry-derived stage (RD-Stage) provides a method for cancer registries to use available data sources to compile and record stage in a consistent way. This project describes the development and validation of rules to capture RD-Stage (pancreatic carcinoma) and applies the rules to data currently captured in each Australian cancer registry. MATERIALS AND METHODS: Rules for deriving RD-stage (pancreatic carcinoma) were developed using the American Joint Commission on Cancer (AJCC) Staging Manual 8th edition and endorsed by an Expert Working Group comprising specialists responsible for delivering care to patients diagnosed with pancreatic carcinoma, cancer registry epidemiologists and medical coders. Completeness of data fields required to calculate RD-Stage (pancreatic carcinoma) and an overall proportion of cases for whom RD stage could be assigned was assessed using data collected by each Australian cancer registry, for period 2018-2019. A validation study compared RD-Stage (pancreatic carcinoma) calculated by the Victorian Cancer Registry with clinical stage captured by the Upper Gastro-intestinal Cancer Registry (UGICR). RESULTS: RD-Stage (pancreatic carcinoma) could not be calculated in 4/8 (50%) of cancer registries; one did not collect the required data elements while three used a staging system not compatible with RD-Stage requirements. Of the four cancer registries able to calculate RD-Stage, baseline completeness ranged from 9% to 76%. Validation of RD-Stage (pancreatic carcinoma) with UGICR data indicated that there was insufficient data available in VCR to stage 174/457 (38%) cases and that stage was unknown in 189/457 (41%) cases in the UGICR. Yet, where it could be derived, there was very good concordance at stage level (I, II, III, IV) between the two datasets. (95.2% concordance], Kendall's coefficient = 0.92). CONCLUSION: There is a lack of standardisation of data elements and data sources available to cancer registries at a national level, resulting in poor capacity to currently capture RD-Stage (pancreatic carcinoma). RD-Stage provides an excellent tool to cancer registries to capture stage when data elements required to calculate it are available to cancer registries.
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Neoplasias Gastrointestinales , Neoplasias Pancreáticas , Humanos , Estados Unidos , Australia/epidemiología , Estadificación de Neoplasias , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/epidemiología , Neoplasias Pancreáticas/patología , Sistema de Registros , Neoplasias Gastrointestinales/patologíaRESUMEN
BACKGROUND: Organoid technology has recently emerged as a powerful tool to assess drug sensitivity of individual patient tumors in vitro. Organoids may therefore represent a new avenue for precision medicine, as this circumvents many of the complexities associated with DNA- or transcriptional-profiling. MATERIALS AND METHODS: The SENSOR trial was a single-arm, single-center, prospective intervention trial to evaluate the feasibility of patient-derived organoids to allocate patients for treatment with off-label or investigational agents. The primary endpoint was an objective response rate of ≥20%. Patients underwent a biopsy for culture before commencing their last round standard of care. Organoids were exposed to a panel of eight drugs and patients were treated after progression on standard-of-care treatment and when a clear signal of antitumor activity was identified in vitro. RESULTS: Sixty-one patients were included and we generated 31 organoids of 54 eligible patients. Twenty-five cultures were subjected to drug screening and 19 organoids exhibited substantial responses to one or more drugs. Three patients underwent treatment with vistusertib and three with capivasertib. Despite drug sensitivity of organoids, patients did not demonstrate objective clinical responses to the recommended treatment. CONCLUSIONS: Organoid technology had limited value as a tool for precision medicine in this patient population because a large fraction of patients could not undergo treatment or because the recommended treatment did not elicit an objective response. We identified several essential parameters, such as the culture success rate, clinical deterioration of patients during standard of care, and rational design of drug panels that need to be accounted for in organoid-guided clinical studies.
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Neoplasias Colorrectales , Preparaciones Farmacéuticas , Neoplasias Colorrectales/tratamiento farmacológico , Humanos , Organoides , Medicina de Precisión , Estudios ProspectivosRESUMEN
BACKGROUND: Pure desmoplastic melanoma (pDM) is an uncommon subtype of malignant melanoma with comparative high rates of local recurrence and low rates of sentinel lymph node positivity. The melanoma-specific survival (MSS) of pDM compared to other melanoma subtypes is unclear, with conflicting reports and lack of multivariable analyses. OBJECTIVES: We aimed to describe clinicopathological characteristics of a cohort of patients with pDM and to compare the MSS of pDM with superficial spreading melanoma (SSM). METHODS: A prospective cohort study was performed of all primary invasive cutaneous pDM with known tumour location and thickness reviewed at a tertiary referral centre over 21 years. RESULTS: A total of 119 primary cutaneous invasive pDMs from 3570 total invasive cutaneous melanomas were included. Compared to 2272 SSMs, and due largely to their greater average thickness, patients with pDM had worse MSS (unadjusted hazard ratio, HR, 2.56, 95% confidence interval, CI, 1.56-4.22). After adjustment for clinicopathologic factors (including thickness, ulceration, mitotic rate, age and sex), there was evidence that patients with pDM had an improved MSS (adjusted HR, 0.49; 95% CI, 0.28-0.87). Median thickness of head and neck pDM was greater than non-head and neck pDM (P < 0.001). There was reduced univariable MSS in head and neck pDM compared to the rest of the body. CONCLUSIONS: Decreased univariable MSS of patients with pDM compared to SSM was explained by the increased frequency of adverse clinicopathologic features at diagnosis, in particular the greater Breslow thickness of pDM. After adjustment, patients with pDM had half the chance of melanoma-specific death compared to SSM. Head and neck pDM were thicker at diagnosis compared to the rest of the body, which may account for its poorer survival compared to the rest of the body.
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Neoplasias de Cabeza y Cuello/patología , Melanoma/patología , Neoplasias Cutáneas/patología , Factores de Edad , Anciano , Anciano de 80 o más Años , Extremidades , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Melanoma/complicaciones , Persona de Mediana Edad , Índice Mitótico , Invasividad Neoplásica , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores Sexuales , Neoplasias Cutáneas/complicaciones , Úlcera Cutánea/etiología , Tasa de Supervivencia , Torso , Carga TumoralRESUMEN
AIMS: Metabolic dysfunction is involved in modulating the disease process in Huntington disease (HD) but the underlying mechanisms are not known. The aim of this study was to investigate if the metabolic regulators sirtuins are affected in HD. METHODS: Quantitative real-time polymerase chain reactions were used to assess levels of SIRT1-3 and downstream targets in post mortem brain tissue from HD patients and control cases as well as after selective hypothalamic expression of mutant huntingtin (HTT) using recombinant adeno-associated viral vectors in mice. RESULTS: We show that mRNA levels of the metabolic regulator SIRT1 are increased in the striatum and the cerebral cortex but not in the less affected cerebellum in post mortem HD brains. Levels of SIRT2 are only increased in the striatum and SIRT3 is not affected in HD. Interestingly, mRNA levels of SIRT1 are selectively increased in the lateral hypothalamic area (LHA) and ventromedial hypothalamus (VMH) in HD. Further analyses of the LHA and VMH confirmed pathological changes in these regions including effects on SIRT1 downstream targets and reduced mRNA levels of orexin (hypocretin), prodynorphin and melanin-concentrating hormone (MCH) in the LHA and of brain-derived neurotrophic factor (BDNF) in the VMH. Analyses after selective hypothalamic expression of mutant HTT suggest that effects on BDNF, orexin, dynorphin and MCH are early and direct, whereas changes in SIRT1 require more widespread expression of mutant HTT. CONCLUSIONS: We show that SIRT1 expression is increased in HD-affected brain regions and that metabolic pathways are altered in the HD hypothalamus.
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Encéfalo/metabolismo , Enfermedad de Huntington/metabolismo , Hipotálamo/metabolismo , Sirtuina 1/metabolismo , Anciano , Femenino , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Masculino , Persona de Mediana Edad , Proteínas del Tejido Nervioso/metabolismo , Neuronas/patologíaAsunto(s)
Melanoma/mortalidad , Nevo Pigmentado/patología , Neoplasias Cutáneas/mortalidad , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Melanoma/etiología , Melanoma/patología , Persona de Mediana Edad , Nevo Pigmentado/complicaciones , Nevo Pigmentado/mortalidad , Pronóstico , Estudios Retrospectivos , Piel/patología , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/patología , Análisis de SupervivenciaAsunto(s)
Melanoma/mortalidad , Neoplasias Primarias Múltiples/mortalidad , Neoplasias Cutáneas/mortalidad , Humanos , Melanoma/genética , Melanoma/patología , Proteínas de Neoplasias/genética , Neoplasias Primarias Múltiples/genética , Neoplasias Primarias Múltiples/patología , Polimorfismo de Nucleótido Simple/genética , Pronóstico , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Análisis de SupervivenciaRESUMEN
We present a case of severe supraspinatus muscle rhabdomyolysis following overexertion in a young male. Preexisting risk factors included illicit drug use. Even single muscle rhabdomyolysis can cause significant renal failure, and in our case the use of intravenous flushing was used in conjunction with hyperbaric oxygen after muscle compartment fasciotomy to maximize muscle recovery and renal protection in a manual worker (musician). Clinicians should be alert to severe muscle pain requiring narcotics after strenuous use.
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Linear IgA bullous dermatosis (LABD) is a subepidermal autoimmune bullous disease characterized by linear IgA deposition at the basement membrane zone, which is visualized by direct immunofluorescence. Patients with LABD typically present with widespread vesicles and bullae; however, this is not necessarily the case, as the clinical presentation of this disease is heterogeneous. LABD clinically presenting as Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) is an infrequent, yet well-described phenomenon. Most cases of LABD are idiopathic, but some cases are drug-induced. Multiple drugs have been implicated in the development of LABD. We report a case of piperacillin-tazobactam-induced LABD presenting clinically as SJS/TEN overlap. This is the first reported case of a strong causal association between piperacillin-tazobactam and the development of LABD.
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Antibacterianos/efectos adversos , Dermatosis Bullosa IgA Lineal/inducido químicamente , Ácido Penicilánico/análogos & derivados , Síndrome de Stevens-Johnson/diagnóstico , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana Edad , Ácido Penicilánico/efectos adversos , Piperacilina/efectos adversos , Combinación Piperacilina y TazobactamRESUMEN
It is assumed that the abundance of Agriotes wireworms (Coleoptera: Elateridae) is affected by agro-ecological factors such as climatic and edaphic factors and the crop/previous crop grown at the sites investigated. The aim of this study, conducted in three different geographic counties in Croatia from 2007 to 2009, was to determine the factors that influence the abundance of adult click beetle of the species Agriotes brevis Cand., Agriotes lineatus (L.), Agriotes obscurus (L.), Agriotes sputator (L.), and Agriotes ustulatus Schall. The mean annual air temperature, total rainfall, percentage of coarse and fine sand, coarse and fine silt and clay, the soil pH, and humus were investigated as potential factors that may influence abundance. Adult click beetle emergence was monitored using sex pheromone traps (YATLORf and VARb3). Exploratory data analysis was preformed via regression tree models and regional differences in Agriotes species' abundance were predicted based on the agro-ecological factors measured. It was found that the best overall predictor of A. brevis abundance was the previous crop grown. Conversely, the best predictor of A. lineatus abundance was the current crop being grown and the percentage of humus. The best predictor of A. obscurus abundance was soil pH in KCl. The best predictor of A. sputator abundance was rainfall. Finally, the best predictors of A. ustulatus abundance were soil pH in KCl and humus. These results may be useful in regional pest control programs or for predicting future outbreaks of these species.
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Agricultura/métodos , Distribución Animal , Clima , Escarabajos/fisiología , Suelo/química , Animales , Croacia , Modelos Biológicos , Densidad de Población , Especificidad de la EspecieRESUMEN
The principles embodied by the Developmental Origins of Health and Disease (DOHaD) view of 'life history' trajectory are increasingly underpinned by biological data arising from molecular-based epigenomic and transcriptomic studies. Although a number of 'omic' platforms are now routinely and widely used in biology and medicine, data generation is frequently confounded by a frequency distribution in the measurement error (an inherent feature of the chemistry and physics of the measurement process), which adversely affect the accuracy of estimation and thus, the inference of relationships to other biological measures such as phenotype. Based on empirical derived data, we have previously derived a probability density function to capture such errors and thus improve the confidence of estimation and inference based on such data. Here we use published open source data sets to calculate parameter values relevant to the most widely used epigenomic and transcriptomic technologies Then by using our own data sets, we illustrate the benefits of this approach by specific application, to measurement of DNA methylation in this instance, in cases where levels of methylation at specific genomic sites represents either (1) a response variable or (2) an independent variable. Further, we extend this formulation to consideration of the 'bivariate' case, in which the co-dependency of methylation levels at two distinct genomic sites is tested for biological significance. These tools not only allow greater accuracy of measurement and improved confidence of functional inference, but in the case of epigenomic data at least, also reveal otherwise cryptic information.
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Epigenómica/métodos , Perfilación de la Expresión Génica/métodos , Animales , Metilación de ADN/genética , Interpretación Estadística de Datos , Teoría de la Probabilidad , Análisis de Regresión , Ovinos/genética , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Biología de Sistemas/métodosRESUMEN
Glioblastoma is the most common and lethal primary malignant brain tumor in adults. The tumor suppressor gene PTEN is deleted, mutated or hypermethylated in more than 60% of glioblastoma cases resulting in hyperactivation of the phosphoinositide 3-kinase pathway, which leads to sustained PI(3,4,5)P3 signaling, and thereby hyperactivation of Akt and other effectors. PI(3,4,5)P3 is also hydrolyzed to PI(3,4)P2 by inositol polyphosphate 5-phosphatases such as SKIP, but the role this pathway has in glioblastoma is unknown. Microarray expression profiling of SKIP in human glioblastoma has revealed both increased and decreased SKIP gene expression. Here we have screened PTEN-deficient glioblastoma for SKIP protein expression by immunohistochemistry and report that SKIP expression is increased in some cases or decreased relative to normal brain. Using the U-87MG PTEN-deficient cell line we show that SKIP knockdown did not further enhance cell proliferation or survival. However, SKIP overexpression in U-87MG cells suppressed anchorage-independent cell growth and growth factor-induced PI(3,4,5)P3/Akt signaling. Although, SKIP knockdown did not affect cell proliferation or survival, cell migration was significantly retarded, associated with significantly increased PI(4,5)P2 signals, and decreased phosphorylation of the actin-regulatory protein cofilin, a PI(4,5)P2-binding protein. Notably, overexpression of SKIP also inhibited migration of U-87MG cells to a similar degree as observed with PTEN reconstitution, however, via distinct mechanisms. PTEN reconstitution promoted sustained lamellipodia generation and focal adhesion formation. In contrast, SKIP overexpression reduced sustained lamellipodia formation, talin incorporation into focal adhesions and recruitment of PI(4,5)P2-binding proteins to the plasma membrane. Notably, analysis of two independent ONCOMINE microarray data sets revealed a significant correlation between increased SKIP mRNA expression in glioblastoma and improved long-term survival. Therefore, SKIP expression in glioblastoma may affect the local invasion of PTEN-deficient tumors.
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Neoplasias Encefálicas/patología , Glioblastoma/patología , Fosfohidrolasa PTEN/genética , Monoéster Fosfórico Hidrolasas/genética , Monoéster Fosfórico Hidrolasas/metabolismo , Neoplasias Encefálicas/enzimología , Neoplasias Encefálicas/genética , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Glioblastoma/enzimología , Glioblastoma/genética , Humanos , Sistema de Señalización de MAP Quinasas , Análisis de Secuencia por Matrices de Oligonucleótidos , Análisis de SupervivenciaRESUMEN
BACKGROUND: Preservation of donor hearts for transplantation has traditionally been performed with the use of static cold storage. We have developed and tested a novel gravity-powered system of cold crystalloid perfusion for prolonged donor heart preservation. METHODS: Greyhounds were anesthetized; their hearts were arrested with cold cardioplegic solution and excised. Hearts were allocated to 12 hours of perfusion preservation (n = 6) or cold storage in ice (n = 5). Non-preserved hearts (n = 5) served as a normal reference group. Perfusion hearts were perfused (20 mL/min, 8-12°C) with a novel oxygenated nutrient-containing preservation solution. After preservation, the recovery of the hearts was assessed in a blood-perfused working heart rig over 2 hours in terms of function, blood lactate level, myocardial adenosine triphosphate, and histology. RESULTS: After 2 hours of reperfusion, in comparison with cold storage hearts, perfused heart function curves showed superior recovery of cardiac output (P = .001), power (P = .001), and efficiency (0.046 ± 0.01 vs 0.004 ± 0.003 joules/mL O2, P = .034). Myocardial adenosine triphosphate content (mmol/mg protein) was reduced significantly from the normal level of 26.5 (15.9, 55.8) to 5.08 (0.50, 10.4) (P = .049) in cold storage hearts but not in perfused hearts. Over a period of 2 hours, lactate levels in the blood perfusate were significantly lower in the perfusion group than in the cold storage group (P < .05). CONCLUSIONS: Continuous hypothermic crystalloid perfusion provides myocardial preservation superior to cold storage for long-term heart preservation, with potential applicability to marginal and donation after circulatory death hearts.
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Soluciones Cardiopléjicas/farmacología , Criopreservación/métodos , Trasplante de Corazón , Soluciones Isotónicas/farmacología , Preservación de Órganos/métodos , Perfusión/métodos , Animales , Soluciones Cristaloides , Modelos Animales de Enfermedad , PerrosRESUMEN
Population differences in visual environment can lead to divergence in multiple components of animal coloration including signalling traits and colour patterns important for camouflage. Divergence may reflect selection imposed by different receivers (conspecifics, predators), which depends in turn on the location of the colour patch. We tested for local adaptation of two genetically and phenotypically divergent lineages of a rock-inhabiting lizard, Ctenophorus decresii, by comparing the visual contrast of colour patches to different receivers in native and non-native environments. The lineages differ most notably in male throat coloration, which is polymorphic in the northern lineage and monomorphic in the southern lineage, but also differ in dorsal and lateral coloration, which is visible to both conspecifics and potential predators. Using models of animal colour vision, we assessed whether lineage-specific throat, dorsal and lateral coloration enhanced conspicuousness to conspecifics, increased crypsis to birds or both, respectively, when viewed against the predominant backgrounds from each lineage. Throat colours were no more conspicuous against native than non-native rock but contrasted more strongly with native lichen, which occurs patchily on rocks inhabited by C. decresii. Conversely, neck coloration (lateral) more closely matched native lichen. Furthermore, although dorsal coloration of southern males was consistently more conspicuous to birds than that of northern males, both lineages had similar absolute conspicuousness against their native backgrounds. Combined, our results are consistent with local adaptation of multiple colour traits in relation to multiple receivers, suggesting that geographic variation in background colour has influenced the evolution of lineage-specific coloration in C. decresii.
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Adaptación Biológica/fisiología , Comunicación Animal , Lagartos/fisiología , Fenotipo , Pigmentación/fisiología , Animales , Color , Modelos Lineales , Masculino , Australia del Sur , Especificidad de la EspecieRESUMEN
OBJECTIVES: To determine the nutrition risk status and factors associated with nutrition risk among older adults enrolled in the Brief Risk Identification Geriatric Health Tool (BRIGHT Trial). DESIGN: A cluster randomised controlled trial. SETTING: Three main centres in New Zealand. PARTICIPANTS: A total of 3,893 older adults were recruited from 60 general practices in three of the District Health Board (DHB) regions aged 75 years and older (or 65 years and older if Maori). MEASUREMENTS: Nutrition risk was assessed using the Australian Nutrition Screening Initiative (ANSI). Validated questionnaires were used to establish quality of life (WHOQOL-BREF), physical function (the Nottingham Extended Activities of Daily Living) and depressive symptoms (15 item Geriatric Depression Scale). Demographic, standard of living and health data were established. RESULTS: Sixty two percent of participants were identified to be at moderate or high nutrition risk. The mean ANSI score was 4.9 (range 0-21, maximum 29). Factors which independently predicted moderate or high nutrition risk were female gender, being Maori and other ethnicities versus European, not being married, taking multiple medications, having more depressive symptoms, cardiovascular disease and diabetes. Protective factors independently related to low nutrition risk were living with others, higher physical and social health related QOL and higher functional status. WHOQOL environmental and psychological factors were not associated with nutrition risk when other predictive factors were taken into account. CONCLUSION: Nearly two thirds of participants were identified to be at higher nutrition risk. Women, living alone, taking multiple medications, with depressive symptoms, cardiovascular disease and ndiabetes were factors associated with higher nutrition risk. Those at low nutrition risk had a better functional status and physical and social health related QOL.
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Desnutrición/epidemiología , Evaluación Nutricional , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/psicología , Análisis por Conglomerados , Estudios Transversales , Depresión/epidemiología , Depresión/psicología , Femenino , Evaluación Geriátrica/métodos , Salud , Conductas Relacionadas con la Salud , Humanos , Modelos Logísticos , Masculino , Actividad Motora , Nueva Zelanda/epidemiología , Prevalencia , Calidad de Vida , Medición de Riesgo , Factores de Riesgo , Factores Socioeconómicos , Encuestas y CuestionariosRESUMEN
Myeloid sarcoma, also commonly termed granulocytic sarcoma or chloroma, is a rare condition involving infiltration of immature myeloid cells in an extramedullary site. Myeloid sarcoma is often related to leukaemia; however, the condition can also occur in association with various myeloproliferative disorders. Although myeloid sarcoma can occur in any body part, involvement of the neoplastic condition in the oral cavity is infrequent with only 37 cases reported in the literature. We will describe two cases of oral myeloid sarcoma observed at The Alfred Hospital's Dental Unit and discuss their presenting features, diagnosis and subsequent management.
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Neoplasias de la Boca/diagnóstico , Sarcoma Mieloide/diagnóstico , Anciano , Resultado Fatal , Femenino , Encía/patología , Humanos , Inmunohistoquímica , Masculino , Prótesis Mandibular , Persona de Mediana Edad , Mucosa Bucal/patología , Neoplasias de la Boca/patología , Sarcoma Mieloide/patologíaRESUMEN
In polymorphic species, population divergence in morph composition and frequency has the potential to promote speciation. We assessed the relationship between geographic variation in male throat colour polymorphism and phylogeographic structure in the tawny dragon lizard, Ctenophorus decresii. We identified four genetically distinct lineages, corresponding to two polymorphic lineages in the Northern Flinders Ranges and Southern Flinders Ranges/Olary Ranges regions respectively, and a monomorphic lineage in the Mt Lofty Ranges/Kangaroo Island region. The degree of divergence between these three lineages was consistent with isolation to multiple refugia during Pleistocene glacial cycles, whereas a fourth, deeply divergent (at the interspecific level) and monomorphic lineage was restricted to western New South Wales. The same four morphs occurred in both polymorphic lineages, although populations exhibited considerable variation in the frequency of morphs. By contrast, male throat coloration in the monomorphic lineages differed from each other and from the polymorphic lineages. Our results suggest that colour polymorphism has evolved once in the C. decresii species complex, with subsequent loss of polymorphism in the Mt Lofty Ranges/Kangaroo Island lineage. However, an equally parsimonious scenario, that polymorphism arose independently twice within C. decresii, could not be ruled out. We also detected evidence of a narrow contact zone with limited genotypic admixture between the polymorphic Olary Ranges and monomorphic Mt Lofty Ranges regions, yet no individuals of intermediate colour phenotype. Such genetic divergence and evidence for barriers to gene flow between lineages suggest incipient speciation between populations that differ in morph composition.