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1.
Toxicol Appl Pharmacol ; 469: 116545, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37146889

RESUMO

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH), is implicated in many developmental and behavioral adverse outcomes in offspring of exposed parents. The objective of this study was to investigate sex-dependent multigenerational effects of preconceptional effects of BaP exposure. Adult wild-type (5D) zebrafish were fed 708 µg BaP/g diet (measured) at a rate of 1% body weight twice/day (14 µg BaP/g fish/day) for 21 days. Fish were spawned using a crossover design, and parental (F0) behavior and reproductive indexes were measured. In offspring, behavioral effects were measured at 96 h post fertilization (hpf) in F1 & F2 larvae, and again when F1s were adults. Compared to controls, there was no significant effect on F0 adult behavior immediately following exposure, but locomotor activity was significantly increased in F1 adults of both sexes. Larval behavior (96 hpf, photomotor response assay) was significantly altered in both the F1 and F2 generations. To assess molecular changes associated with BaP exposure, we conducted transcriptome and DNA methylation profiling in F0 gametes (sperm and eggs) and F1 embryos (10 hpf) from all four crosses. Embryos resulting from the BaP male and control female cross had the most differentially expressed genes (DEGs) and differentially methylated regions (DMRs). Some DMRs were associated with genes encoding chromatin modifying enzymes suggesting regulation of chromatin conformation by DNA methylation. Overall, these results suggest that parental dietary BaP exposure significantly contributes to the multigenerational adverse outcomes.


Assuntos
Metilação de DNA , Exposição Paterna , Animais , Feminino , Masculino , Benzo(a)pireno/toxicidade , Benzo(a)pireno/metabolismo , Estudos Cross-Over , Expressão Gênica , Exposição Paterna/efeitos adversos , Sêmen , Peixe-Zebra/metabolismo
2.
Osteoporos Int ; 27(2): 677-81, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26267012

RESUMO

UNLABELLED: Despite the high burden of hip fracture in China, there is limited information on its management. This study investigated the management of hip fractures in a Beijing tertiary hospital and compared practice with that in 180 hospitals in the UK. The findings show a significant gap exists between the countries. INTRODUCTION: The purpose of this study was to determine if the management of older people with hip fractures in a Beijing tertiary hospital is comparable with the UK best practice guidelines for hip fracture management and the UK National Hip Fracture Database 2012, obtained from 180 hospitals. METHODS: A retrospective audit was undertaken in a large tertiary care hospital in Beijing. Data were compared with the National Hip Fracture Database 2012 collected in 180 hospitals in the UK on the proportion of patients managed according to the UK Blue Book standards. RESULTS: Sixty-six percent of patients were admitted to an orthopaedic ward within 24 h of fracture, while 100 % of patients in the UK were admitted to an orthopaedic ward within 24 h of arrival to an accident and emergency department. Only 8 % of patients received surgery within 48 h of admission compared with 83 % in the UK; 10 % received no surgery compared with 2.5 % in the UK; and 27 % received orthogeriatrician assessment compared with 70 % in the UK. New pressure ulcers developed in 2 % of patients compared with 3.7 % of those in the UK; whereas, 0.3 % of patients were assessed for osteoporosis treatment and 3.8 % received falls assessment, and comparable figures for the UK were 94 and 92 %, respectively. CONCLUSIONS: Significant gaps exist in hip fracture management in the Beijing hospital compared with the best practice achieved in 180 UK hospitals, highlighting the need to implement and evaluate proactive strategies to increase the uptake of best practice hip fracture care in China.


Assuntos
Serviços de Saúde para Idosos/organização & administração , Fraturas do Quadril/terapia , Fraturas por Osteoporose/terapia , Idoso , Idoso de 80 Anos ou mais , China , Gerenciamento Clínico , Medicina Baseada em Evidências , Feminino , Serviços de Saúde para Idosos/normas , Hospitalização , Humanos , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Prática Profissional/normas , Prática Profissional/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Tempo , Reino Unido
3.
Gene Ther ; 21(10): 913-20, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25056608

RESUMO

The cat is emerging as a promising large animal model for preclinical testing of retinal dystrophy therapies, for example, by gene therapy. However, there is a paucity of studies investigating viral vector gene transfer to the feline retina. We therefore sought to study the tropism of recombinant adeno-associated viral (rAAV) vectors for the feline outer retina. We delivered four rAAV serotypes: rAAV2/2, rAAV2/5, rAAV2/8 and rAAV2/9, each expressing green fluorescent protein (GFP) under the control of a cytomegalovirus promoter, to the subretinal space in cats and, for comparison, mice. Cats were monitored for gene expression by in vivo imaging and cellular tropism was determined using immunohistochemistry. In cats, rAAV2/2, rAAV2/8 and rAAV2/9 vectors induced faster and stronger GFP expression than rAAV2/5 and all vectors transduced the retinal pigment epithelium (RPE) and photoreceptors. Unlike in mice, cone photoreceptors in the cat retina were more efficiently transduced than rod photoreceptors. In mice, rAAV2/2 only transduced the RPE whereas the other vectors also transduced rods and cones. These results highlight species differences in cellular tropism of rAAV vectors in the outer retina. We conclude that rAAV serotypes are suitable for use for retinal gene therapy in feline models, particularly when cone photoreceptors are the target cell.


Assuntos
Dependovirus/fisiologia , Proteínas de Fluorescência Verde/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Animais , Gatos , Dependovirus/genética , Feminino , Terapia Genética , Vetores Genéticos/administração & dosagem , Proteínas de Fluorescência Verde/genética , Injeções Intraoculares , Masculino , Camundongos , Células Fotorreceptoras Retinianas Cones/virologia , Células Fotorreceptoras Retinianas Bastonetes/virologia , Transdução Genética , Tropismo Viral
4.
Platelets ; 24(3): 173-82, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22647081

RESUMO

Platelet-rich plasma (PRP), an autologous derivative of whole blood that contains a supraphysiological concentration of platelets, has gained increasing attention in both the scientific literature and the wider media for its potential application in the treatment of traumatic musculoskeletal injury. The theoretical benefit of PRP in providing a local environment for tissue regeneration which is rich in growth factors and other cytokines has been supported by in vitro and animal studies which suggest a positive influence on the migration and proliferation of a number of cell types. However, the reported clinical use of PRP is largely confined to the last two decades and initially centred around its application in dental and maxillofacial surgery. More recently, developments in research of the regenerative effects of PRP in a range of tissue types including bone, cartilage, tendon and muscle, particularly in the context of traumatic injury, have attracted interest in fields such as orthopaedic and plastic surgery where effective union of sometimes poorly vascularised and damaged tissue is a critical determinant of successful clinical outcome. Despite the lack of high-quality trial data, results from clinical studies have been encouraging, and PRP administration remains an attractive strategy given its cost-effective and minimally invasive nature. In this review, we summarise the current literature on the use of PRP and highlight areas of controversy and emerging clinical applications.


Assuntos
Regeneração Tecidual Guiada , Plasma Rico em Plaquetas/fisiologia , Animais , Humanos , Modelos Animais
5.
Angiogenesis ; 12(3): 297-301, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19757106

RESUMO

Rodent models of retinal angiogenesis play a pivotal role in angiogenesis research. These models are a window to developmental angiogenesis, to pathological retinopathy, and are also in vivo tools for anti-angiogenic drug screening in cancer and ophthalmic research. The mouse model of oxygen-induced retinopathy (OIR) has emerged as one of the leading in vivo models for these purposes. Many of the animal studies that laid the foundation for the recent breakthrough of anti-angiogenic treatments into clinical practice were performed in the OIR model. However, readouts from the OIR model have been time-consuming and can vary depending on user experience. Here, we present a computer-aided quantification method that is characterized by (i) significantly improved efficiency, (ii) high correlation with the established hand-measurement protocols, and (iii) high intra- and inter-individual reproducibility of results. This method greatly facilitates quantification of retinal angiogenesis while at the same time increasing lab-to-lab reproducibility of one of the most widely used in vivo models in angiogenesis research.


Assuntos
Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Neovascularização Retiniana/diagnóstico por imagem , Algoritmos , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Eficiência , Fluorescência , Camundongos , Neovascularização Patológica/diagnóstico por imagem , Variações Dependentes do Observador , Oxigênio , Neovascularização Retiniana/induzido quimicamente , Neovascularização Retiniana/patologia
6.
J Cell Biol ; 64(1): 135-45, 1975 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1167320

RESUMO

Mammalian and avian cells cultured on glass or plastic substrates produce microexudates of cellular macromolecules which remain bound to the substrate when the cells are detached. The gross macromolecular composition of microexudates from a range of diploid, heteroploid, and virus-transformed cells was determined with cells labeled with radioisotopes. Significant differences in the amounts of cellular glycoproteins, proteins, and RNA present in microexudates were found between different cell types and between cells of the same type at different stages of growth. Inoculation of cells onto substrates "coated" with microexudates altered their growth behavior. Microexudates from exponentially growing subconfluent homotypic and heterotypic cell populations enhanced the growth of mouse and chick embryo cells seeded at very low densities, but similar microexudates had no effect on the proliferation of cells seeded at higher densities. The enhanced growth of low-density cell populations seeded on microexudates was compared with the growth enhancement produced by feeder cell layers and conditioned medium.


Assuntos
Células Cultivadas/metabolismo , Animais , Divisão Celular , Linhagem Celular , Transformação Celular Neoplásica , Embrião de Galinha , Meios de Cultura , Diploide , Estudos de Avaliação como Assunto , Exsudatos e Transudatos , Glucosamina/metabolismo , Glicoproteínas/biossíntese , Humanos , Leucina/metabolismo , Pulmão/embriologia , Métodos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos CBA , Biossíntese de Proteínas , RNA/biossíntese , Fatores de Tempo , Trítio , Uridina/metabolismo
7.
Bone Joint J ; 101-B(8): 1015-1023, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31362544

RESUMO

AIMS: Hip fractures are associated with high morbidity, mortality, and costs. One strategy for improving outcomes is to incentivize hospitals to provide better quality of care. We aimed to determine whether a pay-for-performance initiative affected hip fracture outcomes in England by using Scotland, which did not participate in the scheme, as a control. MATERIALS AND METHODS: We undertook an interrupted time series study with data from all patients aged more than 60 years with a hip fracture in England (2000 to 2018) using the Hospital Episode Statistics Admitted Patient Care (HES APC) data set linked to national death registrations. Difference-in-differences (DID) analysis incorporating equivalent data from the Scottish Morbidity Record was used to control for secular trends. The outcomes were 30-day and 365-day mortality, 30-day re-admission, time to operation, and acute length of stay. RESULTS: There were 1 037 860 patients with a hip fracture in England and 116 594 in Scotland. Both 30-day (DID -1.7%; 95% confidence interval (CI) -2.0 to -1.2) and 365-day (-1.9%; 95% CI -2.5 to -1.3) mortality fell in England post-intervention when compared with outcomes in Scotland. There were 7600 fewer deaths between 2010 and 2016 that could be attributed to interventions driven by pay-for-performance. A pre-existing annual trend towards increased 30-day re-admissions in England was halted post-intervention. Significant reductions were observed in the time to operation and length of stay. CONCLUSION: This study provides evidence that a pay-for-performance programme improved the outcomes after a hip fracture in England. Cite this article: Bone Joint J 2019;101-B:1015-1023.


Assuntos
Fixação de Fratura/economia , Fraturas do Quadril/economia , Melhoria de Qualidade/economia , Reembolso de Incentivo , Idoso , Idoso de 80 Anos ou mais , Inglaterra , Feminino , Seguimentos , Fixação de Fratura/estatística & dados numéricos , Fraturas do Quadril/mortalidade , Fraturas do Quadril/cirurgia , Humanos , Análise de Séries Temporais Interrompida , Tempo de Internação/economia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Readmissão do Paciente/economia , Readmissão do Paciente/estatística & dados numéricos , Melhoria de Qualidade/estatística & dados numéricos , Escócia , Tempo para o Tratamento/economia , Resultado do Tratamento
8.
Bone Joint J ; 100-B(4): 522-526, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29629594

RESUMO

Aims: The aim of this study was to explore the patients' experience of recovery from open fracture of the lower limb in acute care. Patients and Methods: A purposeful sample of 20 participants with a mean age of 40 years (20 to 82) (16 males, four females) were interviewed a mean of 12 days (five to 35) after their first surgical intervention took place between July 2012 and July 2013 in two National Health Service (NHS) trusts in England, United Kingdom. The qualitative interviews drew on phenomenology and analysis identified codes, which were drawn together into categories and themes. Results: The findings identify the vulnerability of the patients expressed through three themes; being emotionally fragile, being injured and living with injury. The participants felt a closeness to death and continued uncertainty regarding loss of their limb. They experienced strong emotions while also trying to contain their emotions for the benefit of others. Their sense of self changed as they became a person with visible wounds, needed intimate help, and endured pain. When ready, they imagined what it would be like to live with injury. Conclusion: Recovery activities require an increased focus on emotional wellbeing. Surgeons are aware of the need for clinical expertise and for adequate pain relief but may not be as aware that their patients require support regarding their body image and help to imagine their future life. Cite this article: Bone Joint J 2018;100-B:522-6.


Assuntos
Fraturas Expostas/psicologia , Extremidade Inferior/lesões , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Cuidados Críticos , Emoções , Feminino , Fraturas Expostas/terapia , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Dor/psicologia , Pesquisa Qualitativa , Autoimagem
9.
J Hosp Infect ; 63(2): 133-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16621145

RESUMO

The purpose of this study was to assess the impact of deep wound infection after surgery for proximal femoral fracture (PFF) on the patient in terms of mortality and social consequences, and on the National Health Service in terms of financial burden. Sixty-one cases of PFF over a six-year period were complicated with deep surgical wound infection. These cases were compared with a matched control group of 122 patients without infection. Infected cases had greatly increased hospital stay (P<0.001), were 4.5 times less likely to survive to discharge (P=0.002), and if they survived, were three times less likely to return to their original residence (P=0.05). The total cost of treatment per infected case was 24,410 pound sterling compared with 7210 pound sterling for controls (P<0.001). Meticillin-resistant Staphylococcus aureus (MRSA) infection increased admission length and cost compared with non-MRSA infection (P=0.02). Deep wound infection after PFF is a devastating and costly complication for both the patient and the healthcare services. The cost consequences should be considered when allocating resources to trauma services to ensure adequate provision to minimize infection risks and to accommodate treatment costs in this vulnerable group.


Assuntos
Efeitos Psicossociais da Doença , Infecção Hospitalar/economia , Infecção Hospitalar/mortalidade , Fixação de Fratura/efeitos adversos , Fraturas do Quadril/complicações , Custos Hospitalares , Infecção da Ferida Cirúrgica/economia , Infecção da Ferida Cirúrgica/mortalidade , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Infecção Hospitalar/microbiologia , Feminino , Fraturas do Quadril/cirurgia , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Análise por Pareamento , Reoperação , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/microbiologia , Infecção da Ferida Cirúrgica/terapia , Reino Unido/epidemiologia
10.
J Bone Joint Surg Br ; 88(1): 111-5, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16365132

RESUMO

In order to assess the efficacy of inspection and accreditation by the Specialist Advisory Committee for higher surgical training in orthopaedic surgery and trauma, seven training regions with 109 hospitals and 433 Specialist Registrars were studied over a period of two years. There were initial deficiencies in a mean of 14.8% of required standards (10.3% to 19.2%). This improved following completion of the inspection, with a mean residual deficiency in 8.9% (6.5% to 12.7%.) Overall, 84% of standards were checked, 68% of the units improved and training was withdrawn in 4%. Most units (97%) were deficient on initial assessment. Moderately good rectification was achieved but the process of follow-up and collection of data require improvement. There is an imbalance between the setting of standards and their implementation. Any major revision of the process of accreditation by the new Post-graduate Medical Education and Training Board should recognise the importance of assessment of training by direct inspection on site, of the relationship between service and training, and the advantage of defining mandatory and developmental standards.


Assuntos
Acreditação/normas , Educação de Pós-Graduação em Medicina/normas , Ortopedia/educação , Acreditação/organização & administração , Competência Clínica , Corpo Clínico Hospitalar/educação , Ortopedia/normas , Reino Unido
11.
J Bone Joint Surg Br ; 88(9): 1197-203, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16943472

RESUMO

This is a retrospective case review of 237 patients with displaced fractures of the acetabulum presenting over a ten-year period, with a minimum follow-up of two years, who were studied to test the hypothesis that the time to surgery was predictive of radiological and functional outcome and varied with the pattern of fracture. Patients were divided into two groups based on the fracture pattern: elementary or associated. The time to surgery was analysed as both a continuous and a categorical variable. The primary outcome measures were the quality of reduction and functional outcome. Logistic regression analysis was used to test our hypothesis, while controlling for potential confounding variables. For elementary fractures, an increase in the time to surgery of one day reduced the odds of an excellent/good functional result by 15% (p = 0.001) and of an anatomical reduction by 18% (p = 0.0001). For associated fractures, the odds of obtaining an excellent/good result were reduced by 19% (p = 0.0001) and an anatomical reduction by 18% (p = 0.0001) per day. When time was measured as a categorical variable, an anatomical reduction was more likely if surgery was performed within 15 days (elementary) and five days (associated). An excellent/good functional outcome was more likely when surgery was performed within 15 days (elementary) and ten days (associated). The time to surgery is a significant predictor of radiological and functional outcome for both elementary and associated displaced fractures of the acetabulum. The organisation of regional trauma services must be capable of satisfying these time-dependent requirements to achieve optimal patient outcomes.


Assuntos
Acetábulo/lesões , Fraturas Ósseas/cirurgia , Procedimentos Ortopédicos/métodos , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas Ósseas/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/efeitos adversos , Ossificação Heterotópica/diagnóstico por imagem , Ossificação Heterotópica/cirurgia , Complicações Pós-Operatórias , Radiografia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
12.
Bone Joint J ; 98-B(6): 840-5, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27235530

RESUMO

AIMS: We wished to assess the feasibility of a future randomised controlled trial of parathyroid hormone (PTH) supplements to aid healing of trochanteric fractures of the hip, by an open label prospective feasibility and pilot study with a nested qualitative sub study. This aimed to inform the design of a future powered study comparing the functional recovery after trochanteric hip fracture in patients undergoing standard care, versus those who undergo administration of subcutaneous injection of PTH for six weeks. PATIENTS AND METHODS: We undertook a pilot study comparing the functional recovery after trochanteric hip fracture in patients 60 years or older, admitted with a trochanteric hip fracture, and potentially eligible to be randomised to either standard care or the administration of subcutaneous PTH for six weeks. Our desired outcomes were functional testing and measures to assess the feasibility and acceptability of the study. RESULTS: A total of 724 patients were screened, of whom 143 (20%) were eligible for recruitment. Of these, 123 were approached and 29 (4%) elected to take part. However, seven patients did not complete the study. Compliance with the injections was 11 out of 15 (73%) showing the intervention to be acceptable and feasible in this patient population. TAKE HOME MESSAGE: Only 4% of patients who met the inclusion criteria were both eligible and willing to consent to a study involving injections of PTH, so delivering this study on a large scale would carry challenges in recruitment and retention. Methodological and sample size planning would have to take this into account. PTH administration to patients to enhance fracture healing should still be considered experimental. Cite this article: Bone Joint J 2016;98-B:840-5.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Fraturas do Colo Femoral/terapia , Consolidação da Fratura , Fraturas por Osteoporose/terapia , Teriparatida/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Feminino , Fixação Interna de Fraturas , Humanos , Injeções Subcutâneas , Masculino , Adesão à Medicação , Projetos Piloto , Estudos Prospectivos , Autoadministração
13.
J Bone Joint Surg Br ; 87(9): 1253-5, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16129752

RESUMO

Incomplete intertrochanteric fractures do not extend across to the medial femoral cortex and are stable, without rotational deformity or shortening of the lower limb. The aim of our study was to establish whether they can be successfully managed conservatively. A total of 68 patients over a five-year period presented with a suspected fracture of the femoral neck and underwent an MRI scan for further assessment. From these, we retrospectively reviewed eight patients with normal plain radiographs but with an incomplete, intertrochanteric fracture on MRI scan. Five were managed conservatively and three operatively. The mean length of hospital stay was 16 days for the conservatively-treated group and 15 days for those who underwent surgery; this was not statistically significant (p > 0.5) and all patients were mobilised on discharge. Although five patients were readmitted at a mean of 3.2 years after discharge, none had progressed to a complete fracture. We believe that patients with incomplete intertrochanteric fractures should be considered for conservative treatment.


Assuntos
Fraturas do Colo Femoral/diagnóstico , Fraturas do Colo Femoral/terapia , Idoso , Feminino , Fixação de Fratura/métodos , Articulação do Quadril/patologia , Humanos , Tempo de Internação , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
15.
Injury ; 46(6): 945-53, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25816705

RESUMO

BACKGROUND: Hospital admission rates for a number of conditions have been linked to variations in the weather. It is well established that trauma workload displays significant seasonal variation. A reliable predictive model might enable targeting of high-risk groups for intervention and planning of hospital staff levels. To our knowledge there have been no systematic reviews of the literature on the relationship between weather and trauma workload, and predictive models have thus far been informed by the results of single studies. METHODS: We conducted a systematic review of bibliographic databases and reference lists up to June 2014 to identify primary research papers assessing the effect of specified weather conditions including temperature, rainfall, snow, fog, hail, humidity and wind speed on trauma workload, defined as admission to hospital, fracture or a Road Traffic Accident (RTA) resulting in a seriously injured casualty or fatality. RESULTS: 11,083 papers were found through electronic and reference search. 83 full papers were assessed for eligibility. 28 met inclusion criteria and were included in the final review; 6 of these related to the effect of the weather on trauma admissions, one to ambulance call out for trauma, 13 to fracture rate and 8 to RTAs. Increased temperature is positively correlated with trauma admissions. The rate of distal radius fractures is more sensitive to adverse weather than the rate of hip fractures. Paediatric trauma, both in respect of trauma admissions and fracture rate, is more sensitive to the weather than adult trauma. Adverse weather influences both RTA frequency and severity, but the nature of the relationship is dependent upon the timecourse of the weather event and the population studied. Important methodological differences between studies limit the value of the existing literature in building consensus for a generalisable predictive model. CONCLUSIONS: Weather conditions may have a substantial effect on trauma workload independent of the effects of seasonal variation; the population studied and timecourse of weather events appear critical in determining this relationship. Methodological differences between studies limit the validity of conclusions drawn from analysis of the literature, and we identify a number of areas that future research might address.


Assuntos
Hospitalização/estatística & dados numéricos , Estações do Ano , Centros de Traumatologia , Ferimentos e Lesões/etiologia , Acidentes de Trânsito/estatística & dados numéricos , Humanos , Centros de Traumatologia/organização & administração , Centros de Traumatologia/estatística & dados numéricos , Tempo (Meteorologia) , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/prevenção & controle
16.
Biochem Pharmacol ; 55(6): 831-9, 1998 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-9586956

RESUMO

Polynuclear aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants, and recently bioassay-based induction studies have been used to determine exposures to complex mixtures of PAHs. Induction of CYP1A1-dependent activity in H4IIE rat hepatoma cells has been used extensively as a bioassay for halogenated aromatic hydrocarbons and more recently for PAHs. Fluoranthene (FL) is a prevalent PAH contaminant in diverse environmental samples, and FL did not induce CYP1A1-dependent ethoxyresorufin O-deethylase (EROD) activity significantly in H4IIE cells. However, in cells cotreated with 2 x 10(-5) M FL plus the potent inducers 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or benzo[k]fluoranthene (BkF) (2 x 10(-8) M), there was a significant decrease in EROD activities. Furthermore, treatment of TCDD-induced rat microsomes with FL caused an 80% decrease in EROD activity. Studies showed that FL did not affect induction of CYP1A1 protein or mRNA levels in H4IIE cells, and analysis of enzyme inhibition data using microsomal CYP1A1 indicated that FL noncompetitively inhibited CYP1A1-dependent activity. 32P-Postlabeling revealed no significant FL-DNA adduct formation in H4IIE cells treated with FL. However, in cells cotreated with FL plus BkF or benzo[a]pyrene (BaP), certain PAH-DNA adducts were induced 2-fold. This study demonstrated that FL is an inhibitor of CYP1A1-dependent enzyme activity in rat hepatoma H4IIE cells and that the genotoxic potency of some carcinogenic PAHs may be modulated by FL in mixtures containing relatively high levels of this compound.


Assuntos
Citocromo P-450 CYP1A1/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Fluorenos/farmacologia , Animais , Bioensaio , Citocromo P-450 CYP1A1/biossíntese , Adutos de DNA/isolamento & purificação , DNA de Neoplasias/isolamento & purificação , Indução Enzimática , Feminino , Modelos Lineares , Microssomos Hepáticos/enzimologia , Ratos , Ratos Sprague-Dawley , Células Tumorais Cultivadas
17.
Biochem Pharmacol ; 52(4): 587-95, 1996 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-8759031

RESUMO

Recent studies in this laboratory have shown that benzo[a]pyrene (BaP) modulates growth factor-related gene expression and proliferation of renal glomerular mesangial cells (GMCs) in vitro. Because many of the toxic and biochemical effects of this polycyclic aromatic hydrocarbon are mediated through oxidative metabolism, the present studies were conducted to examine the patterns of cytochrome P450IA1 (CYP1A1) and P4501B1 (CYP1B1) inducibility in mesangial cells and the molecular consequences of this response. Exposure of cultured GMCs to BaP (30 microM) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 10 nM) for 24 hr induced CYP1A1 mRNA levels, a response abolished by cotreatment with 10 microM cycloheximide. The pattern of hydrocarbon inducibility was atypical in that BaP was a more effective inducer of CYP1A1 gene expression than TCDD, and both hydrocarbons induced aryl hydrocarbon hydroxylase (AHH) activity, but not ethoxyresorufin-O-deethylase activity. Cotreatment with alpha-naphthoflavone (alpha NF, 1 microM) or ellipticine (ELLIP, 0.1 nM) only partially inhibited the induction of AHH activity by BaP (30 microM). BaP and TCDD also induced expression of the CYP1B1 protein and the pattern of induction was comparable to that observed for CYP1A1. Treatment of GMCs with 30 microM BaP was associated with the formation of eight DNA adducts, and their occurrence could be inhibited by pretreatment with alpha NF (1 microM), but not ELLIP (0.1 nM). These results demonstrate that CYP1A1 and CYP1B1-related activities are induced in GMCs by BaP and TCDD and this induction is associated with metabolism of BaP to reactive intermediates that bind covalently to DNA.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Rim/metabolismo , RNA Mensageiro/metabolismo , Animais , DNA/biossíntese , Ativação Enzimática , Feminino , Ratos , Ratos Sprague-Dawley
18.
Toxicol Sci ; 58(1): 68-76, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11053542

RESUMO

Differential susceptibility of polycyclic aromatic hydrocarbon (PAH)-mediated liver cancer exists in two related species of Ictalurid catfish. Two hypotheses are addressed in this study to explain this difference. Specifically, the relatively insensitive channel catfish 1) do not produce mutagenic PAH metabolites, and/or 2) they more quickly eliminate PAHs due to greater Phase II enzyme activities than the more sensitive brown bullhead. Livers and bile were collected from each species 6, 24, 72, and 168 h after a single 10 mg/kg i.p. benzo(a)pyrene (BaP) exposure. BaP treatment had no significant effect on cytosolic 1-chloro-2,4-dinitrobenzene or ethacrynic acid (EA)-glutathione-S:- transferase (GST) and cis-stilbene oxide-microsomal epoxide hydrolase (EH) activities of either species. Channel catfish EH and GST activities were 1.2-fold higher than brown bullhead activities (p = 0.058 and p < 0.002, respectively). HPLC-APCI-MS of extracted bile and bile enzymatically digested to detect glucuronyl transferase (GT), GST, and sulfotransferase (ST) conjugated metabolites indicated no species differences in elimination or profiles of total biliary metabolites. GT conjugates predominated; ST and GST conjugates were minimal. BaP-diones accounted for the majority of metabolites in both species. Overall, these results indicated that brown bullhead preferentially formed BaP-7,8-dihydrodiol, a precursor to the DNA-reactive BaP-7, 8-dihydrodiol-9,10-epoxide (BPDE), which may be linked to the increased PAH susceptibility in this species.


Assuntos
Benzo(a)pireno/metabolismo , Carcinógenos/metabolismo , Ictaluridae/metabolismo , Animais , Benzo(a)pireno/toxicidade , Bile/metabolismo , Carcinógenos/toxicidade , Citocromo P-450 CYP1A1/metabolismo , Citosol/efeitos dos fármacos , Citosol/metabolismo , DNA/efeitos dos fármacos , Adutos de DNA/efeitos dos fármacos , Dinitroclorobenzeno/metabolismo , Epóxido Hidrolases/metabolismo , Ácido Etacrínico/metabolismo , Glutationa Transferase/metabolismo , Técnicas In Vitro , Fígado/efeitos dos fármacos , Fígado/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Especificidade da Espécie
19.
Med Phys ; 22(5): 611-5, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7643801

RESUMO

Bone mineral densitometry (BMD) is useful in predicting fracture risk, but, unfortunately, there is a significant degree of overlap in BMD measurements of patients who have a high risk of fracture and patients with a low risk of fracture. In this study, a method of characterizing trabecular bone structure in digitized radiographs of vertebrae is proposed and assessed. A significant correlation between bone "structure" and the compressive strength of vertebral bodies was found. The utility of the parameter for distinguishing between "weak" and "strong" bone samples was assessed using receiver operating characteristic (ROC) analysis. Using this analysis, the structural parameter produced an area under the ROC of 0.88 +/- 0.05, while a bone density measure produced an area of 0.79 +/- 0.07. The results suggest that the addition of a measure of bone structure to the conventional measures of bone density may prove useful in predicting the quality of bone when considering surgical or medical intervention for osteoporotic conditions.


Assuntos
Osso e Ossos/anatomia & histologia , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/fisiologia , Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Matemática , Modelos Teóricos , Radiografia , Resistência à Tração , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/fisiologia
20.
J Bone Joint Surg Br ; 73(1): 113-5, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1991742

RESUMO

In the light of EEC proposals on the avoidance of damage to hearing caused by noise, a study was undertaken to determine the risk posed by powered orthopaedic instruments. The noise levels from a number of air-powered and electric tools were measured and analysed and found to exceed the recommended levels. The predicted daily personal noise exposure was calculated and the potential for hearing damage confirmed. Twenty-seven senior orthopaedic staff were then assessed by audiometry; evidence of noise-induced hearing loss was found in half the subjects. The increasing use of powered instruments in elective orthopaedics and fracture fixation may present a significant cumulative risk to the hearing of orthopaedic surgeons and theatre personnel. The use of ear defenders should be promoted, and manufacturers should be encouraged to develop instruments with lower noise emission levels.


Assuntos
Perda Auditiva Provocada por Ruído/etiologia , Ruído Ocupacional/efeitos adversos , Doenças Profissionais/etiologia , Ortopedia , Audiometria , Monitoramento Ambiental , Perda Auditiva Provocada por Ruído/prevenção & controle , Humanos , Ruído Ocupacional/prevenção & controle , Doenças Profissionais/prevenção & controle , Equipamentos Ortopédicos
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