Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Cardiothorac Surg ; 18(1): 63, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36750908

RESUMO

BACKGROUND: Infective endocarditis of the aortic valve is a relatively common disease presentation, with surgical intervention a mainstay of treatment in severe cases. Quadricuspid aortic valves are a rare spontaneous developmental anomaly that are more likely to be asymptomatic, and less likely to require a full valve replacement than their hypocuspid counterparts. However, there is very little literature addressing infective endocarditis of this valve variant. CASE PRESENTATION: This case report presents a case of infective endocarditis of a quadricuspid aortic valve that required replacement with a surgical bioprosthetic valve. The patient is a 30 year old male with a history of polysubstance use, upper extremity aneurysm, and prior tricuspid valve endocarditis. Surgical aortic valve replacement was performed with a 25 mm tissue valve via median sternotomy. CONCLUSIONS: The patient made a full recovery after surgical aortic valve replacement and a course of antibiotics and was discharged home without any complications. This supports that surgical aortic valve replacement is feasible and safe in patients with polycuspid aortic valve endocarditis.


Assuntos
Insuficiência da Valva Aórtica , Endocardite Bacteriana , Endocardite , Válvula Aórtica Quadricúspide , Masculino , Humanos , Adulto , Endocardite Bacteriana/cirurgia , Valva Aórtica/cirurgia , Endocardite/complicações , Insuficiência da Valva Aórtica/cirurgia
2.
Anat Rec (Hoboken) ; 305(10): 2435-2462, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34841701

RESUMO

Pseudosuchians, archosaurian reptiles more closely related to crocodylians than to birds, exhibited high morphological diversity during the Triassic with numerous examples of morphological convergence described between Triassic pseudosuchians and post-Triassic dinosaurs. One example is the shuvosaurid Effigia okeeffeae which exhibits an "ostrich-like" bauplan comprising a gracile skeleton with edentulous jaws and large orbits, similar to ornithomimid dinosaurs and extant palaeognaths. This bauplan is regarded as an adaptation for herbivory, but this hypothesis assumes morphological convergence confers functional convergence, and has received little explicit testing. Here, we restore the skull morphology of Effigia, perform myological reconstructions, and apply finite element analysis to quantitatively investigate skull function. We also perform finite element analysis on the crania of the ornithomimid dinosaur Ornithomimus edmontonicus, the extant palaeognath Struthio camelus and the extant pseudosuchian Alligator mississippiensis to assess the degree of functional convergence with a taxon that exhibit "ostrich-like" bauplans and its closest extant relatives. We find that Effigia possesses a mosaic of mechanically strong and weak features, including a weak mandible that likely restricted feeding to the anterior portion of the jaws. We find limited functional convergence with Ornithomimus and Struthio and limited evidence of phylogenetic constraints with extant pseudosuchians. We infer that Effigia was a specialist herbivore that likely fed on softer plant material, a niche unique among the study taxa and potentially among contemporaneous Triassic herbivores. This study increases the known functional diversity of pseudosuchians and highlights that superficial morphological similarity between unrelated taxa does not always imply functional and ecological convergence.


Assuntos
Jacarés e Crocodilos , Dinossauros , Struthioniformes , Jacarés e Crocodilos/anatomia & histologia , Animais , Evolução Biológica , Dinossauros/anatomia & histologia , Fósseis , Filogenia , Crânio/anatomia & histologia
3.
Science ; 373(6558): 973, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34446597
4.
PeerJ ; 6: e5901, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30581656

RESUMO

Phytosauria is a clade of large, carnivorous, semi-aquatic archosauromorphs which reached its peak diversity and an almost global distribution in the Late Triassic (c. 230-201 Mya). Previous phylogenetic analyses of Phytosauria have either focused primarily on the relationships of specific subclades, or were limited in taxonomic scope, and no taxonomically comprehensive dataset is currently available. We here present the most taxonomically comprehensive cladistic dataset of phytosaurs to date, based on extensive first-hand study, identification of novel characters and synthesis of previous matrices. This results in an almost twofold increase in phylogenetic information scored per taxon over previous analyses. Alongside a traditional discrete character matrix, three variant matrices were analysed in which selected characters were coded using continuous and landmarking methods, to more rigorously explore phytosaur relationships. Based on these four data matrices, four tree topologies were recovered. Relationships among non-leptosuchomorph phytosaurs are largely consistent between these four topologies, whereas those of more derived taxa are more variable. Rutiodon carolinensis consistently forms a sister relationship with Angistorhinus. In three topologies Nicrosaurus nests deeply within a group of traditionally non-Mystriosuchini taxa, leading us to redefine Mystriosuchini by excluding Nicrosaurus as an internal specifier. Two distinct patterns of relationships within Mystriosuchini are present in the four topologies, distinguished largely by the variable position of Mystriosuchus. In two topologies Mystriosuchus forms the most basal clade in Mystriosuchini, whilst in the others it occupies a highly derived position within the Machaeroprosopus clade. 'Redondasaurus' is consistently recovered as monophyletic; however, it also nests within the Machaeroprosopus clade. The greatest impact on tree topology was associated with the incorporation of continuous data into our matrices, with landmark characters exerting a relatively modest influence. All topologies correlated significantly with stratigraphic range estimates. Topological variability in our results highlights clades in which further investigation may better elucidate phytosaur relationships.

5.
PeerJ ; 4: e2718, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27904809

RESUMO

A series of sandstone slabs from Hamstead, Birmingham (West Midlands, UK), preserve an assemblage of tetrapod trackways and individual tracks from the Enville Member of the Salop Formation (late Carboniferous: late Moscovian-Kasimovian). This material has received limited previous study, despite being one of the few British sites to preserve Carboniferous tetrapod footprints. Here, we restudy and revise the taxonomy of this material, and document it using 3D models produced using photogrammetry. The assemblage is dominated by large tracks assigned to Limnopus isp., which were made by early amphibians (temnospondyls). A number of similar but smaller tracks are assigned to Batrachichnus salamandroides (also made by temnospondyls). Dimetropus leisnerianus (made by early synapsids) and Dromopus lacertoides (made by lizard-like sauropsids such as araeoscelids) are also present. This ichnofauna contrasts with a slightly stratigraphically older, more extensive and better-studied assemblage from Alveley (Shropshire), which is dominated by small amphibians with relatively rare reptiliomorphs, but which lacks Dromopus tracks. The presence of Dromopus lacertoides at Hamstead is consistent with the trend towards increasing aridity through the late Carboniferous. It is possible that the assemblage is the stratigraphically oldest occurrence of this important amniote ichnotaxon.

6.
Am J Rhinol Allergy ; 25(4): 226-30, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21819758

RESUMO

BACKGROUND: Matrix metalloproteinase (MMP) 9 is a gelatinase associated with tissue remodeling. It is thought to play a part in the pathogenesis of allergy. Increased levels of MMP-9 have been shown to increase in the acute allergic response in the nose, lungs, and skin. Exposure to passive tobacco smoke is associated with an increase in sneezing, nasal blockage, and a decreased sense of smell. The aim of this study was to study the effect of passive smoking on the levels of MMP-9 in nasal secretions of children. METHODS: A prospective descriptive study was performed. Thirty-nine children aged between 7 and 16 years were enrolled in the study. They were selected based on attendance at the Otorhinolaryngology Outpatients Clinic with a primary complaint unrelated to the nose or paranasal sinuses. Children with allergic rhinitis, sinusitis, or a recent cold were excluded. The study was performed at a tertiary pediatric referral center. Exposure to passive smoking was determined by measuring the urinary cotinine to creatinine ratio. Nasal fluid was obtained by using a Rhino-Probe curette (Arlington Scientific, Inc., Springville, UT). The concentration of MMP-9 was determined by ELISA. MMP-9 activity was determined by gelatin zymography. Data were tabulated on Microsoft Excel (Microsoft Corp., Redmond, WA) and analyzed using SPSS (SPSS Inc., Chicago, IL). RESULTS: Using a cutoff urinary cotinine/creatinine ratio of 0.025 ng/mg, 15 children were found to be exposed to passive smoking. Both the MMP-9 concentration and the activity were significantly higher in nasal secretions of children exposed to passive smoking. There was a distinct difference between the two cohorts with regard to the level of enzyme activity per weight of protein. The lowest level of enzyme activity recorded in the "exposed" cohort was over twice that of the level in the "not exposed" cohort. CONCLUSION: MMP-9 activity and concentration is higher in nasal secretions of children exposed to passive smoking. This suggests that passive smoking might alter the inflammatory response within the nasal mucosa in a similar way to allergy.


Assuntos
Cotinina/urina , Creatinina/urina , Metaloproteinase 9 da Matriz/metabolismo , Seios Paranasais/metabolismo , Poluição por Fumaça de Tabaco/estatística & dados numéricos , Adolescente , Secreções Corporais/efeitos dos fármacos , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Inflamação , Masculino , Metaloproteinase 9 da Matriz/genética , Seios Paranasais/efeitos dos fármacos , Seios Paranasais/patologia , Estudos Prospectivos , Poluição por Fumaça de Tabaco/efeitos adversos
7.
Cancer ; 117(13): 2939-50, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21692053

RESUMO

BACKGROUND: Recent genetic studies have implicated p53 mutation as a significant risk factor for therapeutic failure in squamous cell carcinoma of the head and neck (SCCHN). However, in a recent meta-analysis in the literature of p53 from major anatomical subsites (larynx, oral cavity, oropharynx/hypopharynx), associations between patient survival and p53 status were ambiguous. METHODS: The authors examined a cohort of SCCHNs using a previously developed biomarker combination that likely predicts p53 status based on p53/MDM2 expression levels determined by immunohistochemistry (IHC). In addition, the authors generated and validated an antibody to MTBP (an MDM2 binding protein that alters p53/MDM2 homeostasis and may contribute to metastatic suppression) and have incorporated data for MTBP expression into the current analyses. RESULTS: Analysis of expression data for p53 and MDM2 in 198 SCCHN patient samples revealed that the biomarker combination p53 + ve/MDM2-low (likely indicative of p53 mutation) was significantly associated with reduced overall survival (log-rank P = .035) and was an independent prognostic factor (P = .013; HR, 1.705; 95% CI, 1.12-2.60); thus, these data were compatible with earlier genetic analyses. By using IHC for p53 and MDM2 to dichotomize patients, the authors found that loss of MTBP expression was significantly associated with reduced survival (log-rank P = .004) and was an independent prognostic factor (P = .004; HR, 2.78; 95% CI, 1.39-5.54) in p53 + ve/MDM2-low patients. CONCLUSIONS: These results represent the first examination of MTBP expression in human tissues and provide evidence for a p53 status-dependent role for MTBP in suppressing disease progression in SCCHN patients as well as confirming a role for p53 pathway function in delaying disease progression.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Idoso , Biomarcadores Tumorais/metabolismo , Western Blotting , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/mortalidade , Carcinoma/patologia , Carcinoma de Células Escamosas , Proteínas de Transporte/genética , Progressão da Doença , Feminino , Imunofluorescência , Genes p53 , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mutação , Neoplasias de Células Escamosas/genética , Neoplasias de Células Escamosas/metabolismo , Neoplasias de Células Escamosas/mortalidade , Neoplasias de Células Escamosas/patologia , Reação em Cadeia da Polimerase , Prognóstico , Proteínas Proto-Oncogênicas c-mdm2/genética , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço , Análise Serial de Tecidos , Falha de Tratamento
8.
Otolaryngol Head Neck Surg ; 144(1): 29-35, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21493383

RESUMO

OBJECTIVE: Head and neck squamous cell carcinoma (HNSCC) patients with N3 neck disease at presentation are the minority. Prognosis for such patients is poor, but there is disagreement about which treatment policy is best adopted. The aim of this study was to identify which groups of patients are best offered radical treatment, examining factors of association, prognosis, and survival. STUDY DESIGN: Prospective cohort study. SETTING: Regional tertiary head and neck cancer unit. SUBJECTS AND METHODS: Data were collected prospectively from patients treated for HNSCC with N3 nodal disease between 1975 and 2005. The data collected included age, sex, tumor TNM stage, histological grade, treatment, and survival. Odds ratio was used to calculate whether each parameter was statistically significant. Tumor-specific and observed survival curves were also calculated. RESULTS: A total of 275 patients had N3 disease. Multivariate analysis confirmed that advanced disease at the primary site (odds ratio = 4.6, P = .0261) mitigated against curative treatment. Comparison of tumor-specific survival between curative and palliative treatment strategies suggests that aggressive treatment is associated with greatly improved survival (median survival = 1.45 years, 95% confidence interval [CI] = 1.23-1.67 years; 5-year survival = 26.6%, CI = 17.14%-36.06%) compared with those treated palliatively (median survival = 3.18 months, CI = 3.06-3.30 months; no 5-year survivors; P < .0001). CONCLUSION: A major factor in determining treatment strategies for N3 disease HNSCC is the extent of disease at the primary site. These data suggest that aggressive treatment of the neck improves survival and should be considered in these patients.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Carcinoma/mortalidade , Carcinoma/secundário , Carcinoma/terapia , Terapia Combinada , Seguimentos , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/secundário , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Metástase Linfática , Estadiamento de Neoplasias , Neoplasias de Células Escamosas/mortalidade , Neoplasias de Células Escamosas/secundário , Neoplasias de Células Escamosas/terapia , Estudos Prospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Taxa de Sobrevida/tendências , Fatores de Tempo , Reino Unido/epidemiologia
9.
Sensors (Basel) ; 10(1): 913-32, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22315576

RESUMO

Spatial and temporal soil moisture dynamics are critically needed to improve the parameterization for hydrological and meteorological modeling processes. This study evaluates the statistical spatial structure of large-scale observed and simulated estimates of soil moisture under pre- and post-precipitation event conditions. This large scale variability is a crucial in calibration and validation of large-scale satellite based data assimilation systems. Spatial analysis using geostatistical approaches was used to validate modeled soil moisture by the Agriculture Meteorological (AGRMET) model using in situ measurements of soil moisture from a state-wide environmental monitoring network (Oklahoma Mesonet). The results show that AGRMET data produces larger spatial decorrelation compared to in situ based soil moisture data. The precipitation storms drive the soil moisture spatial structures at large scale, found smaller decorrelation length after precipitation. This study also evaluates the geostatistical approach for mitigation for quality control issues within in situ soil moisture network to estimates at soil moisture at unsampled stations.


Assuntos
Monitoramento Ambiental/métodos , Modelos Estatísticos , Solo/análise , Solo/química , Água/análise , Simulação por Computador
10.
Head Neck ; 30(11): 1514-22, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18642287

RESUMO

Treatment of neck recurrence following radical neck dissection is extremely difficult. Retrospective review of 699 radical neck dissections was performed. Recurrence rates, host, tumor, treatment factors, and survival were analyzed. One hundred nineteen patients who had undergone radical neck dissections had recurrence, 69 were considered candidates for salvage surgery. Factors that increased the risk of neck recurrence were neck node (N) status and no adjuvant radiotherapy. Factors associated with radical salvage treatment were young age, good general condition, and low recurrent N classification. Five-year survival for salvage neck dissection was 31%. Young patients and low T and N classification did well. Low recurrent N classification and salvage surgery were associated with good prognosis for recurrence. In our study, radical neck dissection has a regional failure rate of 20%, a third of recurrence cases were offered curative treatment. Of these, 31% were cured with salvage surgery.


Assuntos
Carcinoma de Células Escamosas/secundário , Neoplasias de Cabeça e Pescoço/patologia , Esvaziamento Cervical , Recidiva Local de Neoplasia , Terapia de Salvação/métodos , Idoso , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/cirurgia , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida
11.
Ann Otol Rhinol Laryngol ; 116(2): 92-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17388231

RESUMO

OBJECTIVES: Squamous cell carcinoma of the tongue base has a poor prognosis, and treatment is accompanied by a number of major problems. In view of this, it is important to recognize which patients will benefit from treatment with curative intent and which treatment method to use. METHODS: One hundred sixty-five patients with squamous cell carcinoma of the tongue base were identified on our database. Eighty-two patients were treated by radical irradiation, and 41 by surgery. A further 42 patients were considered unsuitable for curative treatment. RESULTS: The 5-year cause-specific survival rate was 41% for those treated by irradiation, 58% for those treated by surgery, and 9% for untreated patients. There was no difference in the efficacy of treatment methods (p = .5362), but a highly significant difference was seen in survival rate between treated and untreated patients (p = .0028). The decision regarding administration of curative treatment was based on the extent of locoregional involvement at the primary site (p = .0139; odds ratio, 0.43) and in the neck (p = .0078; odds ratio, 0.23). No factors affected the decision to treat by irradiation or surgery. When the observed survival rate was calculated, there was no significant difference in 5-year survival rate between treated and untreated patients (p = .2762). Those with early (T1-2) disease at the primary site had an improved survival rate from 0.5 to 4 years compared with those who were untreated (T3-4; p = .0081; odds ratio, 2.2). In addition, those with early (T1-2) disease had a better survival rate than those with advanced cancers (p = .0139; odds ratio, 2.09). There was, however, no difference in survival rate at 5 years. Those with early disease compared with those with advanced disease were twice as likely to be alive at 2 years; however, all survival advantages had disappeared by 5 years. CONCLUSIONS: In terms of observed survival, treating tongue base squamous cell carcinoma that is locally advanced (T3-4) at presentation offers no survival advantage over palliation alone. Treating early disease (T1-2) doubles the survival rate for up to 4 years, but by 5 years this survival advantage is lost. The present study finds radiotherapy and surgery to be equivalent at controlling this disease.


Assuntos
Carcinoma de Células Escamosas , Tomada de Decisões , Cuidados Paliativos/métodos , Neoplasias da Língua , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirurgia , Inglaterra/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Neoplasias da Língua/mortalidade , Neoplasias da Língua/radioterapia , Neoplasias da Língua/cirurgia
12.
Eur Arch Otorhinolaryngol ; 263(6): 541-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16767468

RESUMO

The accepted method of modelling and predicting failure/survival, Cox's proportional hazards model, is theoretically inferior to neural network derived models for analysing highly complex systems with large datasets. A blinded comparison of the neural network versus the Cox's model in predicting survival utilising data from 873 treated patients with laryngeal cancer. These were divided randomly and equally into a training set and a study set and Cox's and neural network models applied in turn. Data were then divided into seven sets of binary covariates and the analysis repeated. Overall survival was not significantly different on Kaplan-Meier plot, or with either test model. Although the network produced qualitatively similar results to Cox's model it was significantly more sensitive to differences in survival curves for age and N stage. We propose that neural networks are capable of prediction in systems involving complex interactions between variables and non-linearity.


Assuntos
Carcinoma de Células Escamosas/mortalidade , Neoplasias Laríngeas/mortalidade , Modelos Estatísticos , Redes Neurais de Computação , Humanos , Dinâmica não Linear , Modelos de Riscos Proporcionais , Estudos Prospectivos , Análise de Sobrevida
13.
J Laryngol Otol ; 118(7): 500-7, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15318955

RESUMO

Prostaglandins and leukotrienes are implicated in conditions of both the upper and lower airways. In the former they are deranged in nasal polyposis, intrinsic rhinitis and allergic rhinitis while in the latter they are involved in the pathogenesis of asthma. The aim of the present study was to measure mucosal eicosanoid levels in the three types of rhinitis and compare with controls. In addition, the effect of topical steroids on eicosanoid levels in rhinitis was examined. The levels of prostaglandins E(2) (PGE(2)) and D(2) (PGD(2)) and of leukotrienes E(4) (LTE(4)) and B(4) (LTB(4)) were measured in nasal biopsies from the inferior turbinates of patients suffering from perennial rhinitis and a control group. Rhinitis patients were classified into three categories: perennial allergic rhinitis (PAR), non-allergic rhinitis with eosinophilia (NARES) and noneosinophilic non-allergic rhinitis (NENAR) on the basis of symptoms, secretion eosinophilia, nasal resistance and allergy testing. Patients with rhinitis were randomized into two groups. One received fluticasone propionate nasal spray (FPANS) and the other a placebo (PNS) over a period of six weeks prior to the biopsies. One hundred and one patients with PAR, NARES or NENAR were recruited sequentially and the control group consisted of 21 patients with no evidence of rhinitis but with nasal obstruction due to septal deviation. Untreated rhinitics had significantly lower levels of PGE(2), PGD(2) and LTE(4) than non-rhinitic controls. Six-weeks' treatment with FPANS significantly increased the levels of those eicosanoids in patients with PAR and NARES but they were still significantly below normal. Levels of LTB(4) in all three rhinitis groups were not significantly different from controls and treatment with topical steroids had no effect. Their findings are contrary to current thinking that increased levels of eicosanoids, in particular cysteinyl-leukotrienes, play an important role in the pathogenesis of chronic, non-infective upper airway inflammation.


Assuntos
Leucotrienos/análise , Prostaglandinas/análise , Rinite Alérgica Perene/metabolismo , Resistência das Vias Respiratórias , Androstadienos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Doença Crônica , Dinoprostona/análise , Método Duplo-Cego , Eosinófilos/patologia , Fluticasona , Humanos , Contagem de Leucócitos , Leucotrieno B4/análise , Leucotrieno E4/análise , Mucosa Nasal/química , Mucosa Nasal/patologia , Pólipos Nasais/metabolismo , Prostaglandina D2/análise , Rinite/tratamento farmacológico , Rinite/metabolismo , Rinite/patologia , Rinite/fisiopatologia , Rinite Alérgica Perene/tratamento farmacológico , Rinite Alérgica Perene/patologia , Rinite Alérgica Perene/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...