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1.
Rev Sci Instrum ; 94(2): 025008, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36859065

RESUMO

Measuring the polydisperse beam of charged species emitted by an electrospray device requires accurate measurements of current. Secondary species emission (SSE) caused by high-velocity nanodroplet or molecular ion impacts on surfaces contributes to substantial uncertainty in current measurements. SSE consists of both positive and negative species; hence, mitigating measurement uncertainty requires different considerations other than plasma diagnostic techniques. The probe and analysis methods described herein distinguish between current contributions from positive SSE, negative SSE, and primary species. Separating each contribution provides positive and negative SSE yield measurements and corrected current measurements that reflect the true primary current. Sources of measurement uncertainty in probe design are discussed, along with appropriate mitigation methods. The probe and analysis techniques are demonstrated on an ionic liquid electrospray operating in a droplet emission mode to obtain an angular distribution of positive and negative SSE yields for an ionic liquid electrospray.

2.
EPMA J ; 6(1): 18, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26379805

RESUMO

Predictive, Preventive and Personalized Medicine as the Medicine of the Future represents an innovative model for advanced healthcare and robust platform for relevant industrial branches for diagnostics and pharmaceutics. However, rapid market penetration of new medicines and technologies demands the implementation of reforms not only in the spheres of biopharmaceutical industries and healthcare, but also in education. Therefore, the problem of the fundamental, modern preparation of specialists in bioengineering and affiliated fields is becoming particularly urgent, and it requires significant revision of training programs of higher education practice into current medical universities. Modernization and integration of widely accepted medical and teaching standards require consolidation of both the natural sciences and medical sciences that may become the conceptual basis for a university medical education. The main goal of this training is not simply to achieve advanced training and expansion of technological skills, but to provide development of novel multifaceted approaches to build academic schools for future generations.

3.
Heredity (Edinb) ; 107(3): 231-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21343947

RESUMO

Human-induced alteration of natural habitats has the potential to impact on the genetic structuring of remnant populations at multiple spatial scales. Species from higher trophic levels, such as snakes, are expected to be particularly susceptible to land-use changes. We examined fine-scale population structure and looked for evidence of sex-biased dispersal in smooth snakes (Coronella austriaca), sampled from 10 heathland localities situated within a managed coniferous forest in Dorset, United Kingdom. Despite the limited distances between heathland areas (maximum <6 km), there was a small but significant structuring of populations based on eight microsatellite loci. This followed an isolation-by-distance model using both straight line and 'biological' distances between sampling sites, suggesting C. austriaca's low vagility as the causal factor, rather than closed canopy conifer forest exerting an effect as a barrier to dispersal. Within population comparisons of male and female snakes showed evidence for sex-biased dispersal, with three of four analyses finding significantly higher dispersal in males than in females. We suggest that the fine-scale spatial genetic structuring and sex-biased dispersal have important implications for the conservation of C. austriaca, and highlight the value of heathland areas within commercial conifer plantations with regards to their future management.


Assuntos
Colubridae/genética , Ecossistema , Repetições de Microssatélites , Animais , Inglaterra , Feminino , Especiação Genética , Variação Genética , Genoma , Masculino , Dinâmica Populacional , Caracteres Sexuais
4.
Biol Lett ; 6(6): 777-80, 2010 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-20534600

RESUMO

Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined sharply over the same relatively short period of time with five remaining stable and one showing signs of a marginal increase. Although the causes of these declines are currently unknown, we suspect that they are multi-faceted (such as habitat quality deterioration, prey availability), and with a common cause, e.g. global climate change, at their root.


Assuntos
Serpentes , Animais , Austrália , Biodiversidade , Mudança Climática , Ecossistema , Europa (Continente) , Feminino , Cadeia Alimentar , Masculino , Nigéria , Dinâmica Populacional , Especificidade da Espécie , Fatores de Tempo
5.
Clin Exp Immunol ; 158(3): 308-16, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19793336

RESUMO

16alpha-Bromoepiandrosterone (HE2000) is a synthetic steroid that limits non-productive inflammation, enhances protective immunity and improves survival in clinical studies of patients with human immunodeficiency virus (HIV), malaria and tuberculosis infections. We now show that HE2000 decreased nitric oxide production by lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Treatment with HE2000 also reduced non-productive inflammation associated with carrageenan-induced pleurisy and LPS-induced lung injury in mice. In the hapten-carrier reporter antigen popliteal lymph node assay, HE2000 increased absolute numbers of lymphocytes, antigen-presenting cells, hapten-specific immunoglobulin (Ig)M antibody-forming cells and shifted the interferon (IFN)-gamma/interleukin (IL)-4 balance towards IFN-gamma production. In the cystic fibrosis transmembrane conductance regulator (CFTR(-/-)) mouse model of acute Pseudomonas aeruginosa infection, treatment with HE2000 consistently reduced bacterial burden in lungs. All HE2000 effects were dose-dependent. In H1N1 infection in mice, HE2000 was safe but not effective as a monotherapy, as treatment did not effect survival. HE2000 reduced mortality related to excessive inflammation and opportunistic lung infections in animals and patients, and this might extend to those with H1N1 influenza infection.


Assuntos
Androsterona/análogos & derivados , Pulmão/imunologia , Pneumonia/prevenção & controle , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/prevenção & controle , Androsterona/farmacologia , Androsterona/uso terapêutico , Animais , Carragenina , Células Cultivadas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Imunidade Inata/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1 , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Óxido Nítrico/biossíntese , Infecções Oportunistas/prevenção & controle , Infecções por Orthomyxoviridae/tratamento farmacológico , Pleurisia/induzido quimicamente , Pleurisia/imunologia , Pleurisia/prevenção & controle , Pneumonia/induzido quimicamente , Pneumonia/imunologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa
6.
Ann N Y Acad Sci ; 1173: 781-90, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19758229

RESUMO

HE3286 (17alpha-ethynyl-5-androstene-3beta, 7beta, 17beta-triol) is a synthetic derivative of a natural anti-inflammatory steroid, beta-AET (5-androstene-3beta, 7beta, 17beta-triol). HE3286 is orally bioavailable and treats established disease in models of ulcerative colitis, collagen-induced arthritis, and collagen antibody-induced arthritis, reducing clinical signs of disease and proinflammatory signals, including IL-6 and matrix metallopeptidase 3. HE3286 modulates nuclear factor kappaB through an unknown mechanism but does not interact with any of the steroid-binding nuclear hormone receptors and is not immune suppressive. HE3286 was safe and well tolerated in phase I studies and is under evaluation in multicenter phase I/II clinical trials for ulcerative colitis and arthritis. HE3286 may provide a new treatment option for patients with inflammatory and autoimmune diseases.


Assuntos
Doenças Autoimunes/tratamento farmacológico , Desidroepiandrosterona/análogos & derivados , Administração Oral , Androstenóis/administração & dosagem , Androstenóis/uso terapêutico , Animais , Ensaios Clínicos como Assunto , Colite Ulcerativa/tratamento farmacológico , Desidroepiandrosterona/administração & dosagem , Desidroepiandrosterona/uso terapêutico , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Estradiol/administração & dosagem , Estradiol/análogos & derivados , Estradiol/uso terapêutico , Antagonistas de Estrogênios/administração & dosagem , Antagonistas de Estrogênios/uso terapêutico , Feminino , Fulvestranto , Humanos , Masculino , Camundongos , Camundongos Endogâmicos , Ratos , Ratos Wistar , Resultado do Tratamento
7.
Br J Cancer ; 100(7): 1068-72, 2009 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-19337256

RESUMO

Androst-5-ene-3beta, 17beta-diol (AED) is an adrenal hormone that has been reported to sustain prostate cancer growth after androgen deprivation therapy (ADT). LNCaP cells express a mutated androgen receptor that confers the ability to respond not only to androgen but also to oestrogen and adrenal hormones such as AED, and thus provide a cell line useful for identifying compounds capable of inhibiting AED-stimulated cell growth. We sought to determine whether structurally related steroids could inhibit AED-stimulated LNCaP cell growth in vitro and tumour growth in vivo. We report here the identification of a novel androstane steroid, HE3235 (17alpha-ethynyl-5alpha-androstan-3alpha, 17beta-diol), with significant inhibitory activity for AED-stimulated LNCaP proliferation. This inhibitory activity is accompanied by an increase in the number of apoptotic cells. Animal studies have confirmed the cytoreductive activity of HE3235 on LNCaP tumours. The results suggest that this compound may be of clinical use in castration-resistant prostate cancer.


Assuntos
Androstanóis/farmacologia , Androstenodiol/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos SCID , Neoplasias da Próstata/patologia , Receptores Androgênicos/genética
8.
Rev Sci Instrum ; 78(9): 093101, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17902941

RESUMO

Life-limiting processes in hollow cathodes are determined largely by the temperature of the electron emitter. To support cathode life assessment, a noncontact temperature measurement technique which employs a stepper motor-driven fiber optic probe was developed. The probe is driven inside the hollow cathode and collects light radiated by the hot interior surface of the emitter. Ratio pyrometry is used to determine the axial temperature profile. Thermocouples on the orifice plate provide measurements of the external temperature during cathode operation and are used to calibrate the pyrometer system in situ with a small oven enclosing the externally heated cathode. The diagnostic method and initial measurements of the temperature distribution in a hollow cathode are discussed.

9.
Ann N Y Acad Sci ; 1110: 630-40, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17911478

RESUMO

Dehydroepiandrosterone (DHEA) has attracted much interest because of its many antiaging, metabolic and immune-modulating effects in rodents. Synthetic derivatives, such as 5-androstene-16alpha-fluoro-17-one (HE2500) and certain natural metabolites also provide benefit in various animal models of autoimmune and metabolic diseases. But, like DHEA, low potency and low oral bioavailability suggested limited usefulness of these compounds in humans. We hypothesized that HE3286, a novel 17-ethynyl derivative would be orally bioavailable, more potent, and chemically more useful in man than its parent compound. We found that on a dose/mass basis, HE3286 demonstrated up to 25% oral bioavailability in mice. In the DBA mouse model of collagen-induced arthritis (CIA), animals receiving oral treatment with HE3286 (50 mg/kg), beginning at onset of disease, significantly decreased CIA peak scores and daily severity of arthritis scores. Benefit was associated with decreases in: (1) production of TNF-alpha, IL-6, and IL-17; and (2) decreases in joint inflammation, erosion, and synovial proliferation as judged by histological analysis. HE3286 was not found to be immune suppressive in any of the classical models tested, including mitogen-induced proliferation, delayed-type hypersensitivity, or mixed lymphocyte reaction. Instead, benefit was associated with increases in numbers and function of CD4+CD25+FOXp3+CD127- regulatory T cells (T reg). To our knowledge, this is probably the first study to report that an orally bioavailable synthetic analogue of DHEA can ameliorate ongoing disease in a CIA mouse model with relevance to rheumatoid arthritis (RA) and to correlate that finding with decreases in proinflammatory cytokines and increases in T reg cells. Hormones targeting T reg cells hold the intriguing potential to treat autoimmune, infectious, and neoplastic diseases.


Assuntos
Androstenos/antagonistas & inibidores , Androstenos/metabolismo , Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Desidroepiandrosterona/análogos & derivados , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Administração Oral , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/patologia , Bovinos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo II/farmacologia , Desidroepiandrosterona/farmacologia , Masculino , Camundongos , Baço/efeitos dos fármacos , Líquido Sinovial/citologia , Líquido Sinovial/efeitos dos fármacos , Linfócitos T Reguladores/citologia
10.
Oecologia ; 151(1): 125-31, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17024381

RESUMO

There is general consensus that climate change has contributed to the observed decline, and extinction, of many amphibian species throughout the world. However, the mechanisms of its effects remain unclear. A laboratory study in 1980-1981 in which temperate zone amphibians that were prevented from hibernating had decreased growth rates, matured at a smaller size and had increased mortality compared with those that hibernated suggested one possible mechanism. I used data from a field study of common toads (Bufo bufo) in the UK, between 1983 and 2005, to determine whether this also occurs in the field. The results demonstrated two pathways by which global warming may cause amphibian declines. First, there was a clear relationship between a decline in the body condition of female common toads and the occurrence of warmer than average years since 1983. This was paralleled by a decline in their annual survival rates with the relationship between these two declines being highly correlated. Second, there was a significant relationship between the occurrence of mild winters and a reduction in female body size, resulting in fewer eggs being laid annually. Climate warming can, therefore, act on wild temperate zone amphibians by deleteriously affecting their physiology, during and after hibernation, causing increased female mortality rates and decreased fecundity in survivors.


Assuntos
Constituição Corporal/fisiologia , Bufo bufo/fisiologia , Clima , Efeito Estufa , Animais , Inglaterra , Feminino , Estudos Longitudinais , Densidade Demográfica , Dinâmica Populacional , Análise de Sobrevida
11.
Clin Microbiol Infect ; 12(11): 1082-8, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17002607

RESUMO

A randomised, double-blind, placebo-controlled study examined the safety, tolerance, immunological effect and anti-human immunodeficiency virus (HIV) activity of sub-cutaneously administered HE2000 (16alpha-bromoepiandrosterone) as monotherapy in treatment-naïve patients with HIV-1. Twenty-four patients received five sequential daily doses of 50 or 100 mg of HE2000 or placebo every 6 weeks for up to three courses, and were followed thereafter for 3 months. HE2000 was safe, with transient injection site reactions being the main side-effect. Peripheral blood samples, collected serially, were analysed for changes in immune cell phenotypes. Significant increases were observed in the numbers of circulating dendritic cells, early activated (CD69+ CD25-) CD8 T-cells and T-NK cells after administration of 50-mg doses of HE2000 (p < 0.05). Gene expression in peripheral blood mononuclear cells was analysed by real-time RT-PCR. Before treatment, HIV-1-infected patients had significantly elevated transcripts for a number of inflammatory mediators (p < 0.012). After 50 mg or 100 mg HE2000, but not after placebo, there were significant sustained decreases in IL-1beta, TNF-alpha, IL-6 and Cox-2 transcripts (p < 0.05). There were no significant differences in CD4 cell numbers, although patients receiving 50-mg doses demonstrated a significant decrease in viral load (- 0.6 log; p < 0.01). Anti-HIV-1 T-cell responses were analysed serially using GAG-peptides to stimulate cytoplasmic IFN-gamma responses. After three courses, the 50-mg dose group demonstrated a significant increase in CD8 T-cell response against two distinct GAG peptide pools (p < 0.03). These findings suggest that immune-based therapies may be able to impact viral load by decreasing inflammation and/or stimulating CD8 T-cells.


Assuntos
Androsterona/análogos & derivados , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1 , Adulto , Androsterona/administração & dosagem , Androsterona/uso terapêutico , Fármacos Anti-HIV/administração & dosagem , Antígenos CD/análise , Antígenos de Diferenciação de Linfócitos T/análise , Contagem de Células , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Células Dendríticas/citologia , Método Duplo-Cego , Feminino , Citometria de Fluxo , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Injeções Subcutâneas , Interleucina-1/genética , Interleucina-1/metabolismo , Subunidade alfa de Receptor de Interleucina-2/análise , Interleucina-6/genética , Interleucina-6/metabolismo , Células Matadoras Naturais/imunologia , Lectinas Tipo C , Contagem de Leucócitos , Leucócitos Mononucleares/metabolismo , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , RNA Mensageiro/análise , Kit de Reagentes para Diagnóstico , Linfócitos T/imunologia , Resultado do Tratamento , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Carga Viral
12.
Mar Pollut Bull ; 53(1-4): 155-64, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16253290

RESUMO

The managed realignment of coastal defences and subsequent creation of intertidal habitats is one of several 'soft' engineering options that could reduce the costs of maintaining embankments and at the same time deliver environmental benefits. The managed realignment at Tollesbury was one of the first in the UK, undertaken as an experimental test case to improve understanding of the practical techniques and processes involved. Independent studies were undertaken on the development of soils, benthic invertebrates and vegetation within the site in addition to methods of enhancing the process of natural colonisation of saltmarsh plants. Bathymetric and vegetation monitoring were undertaken on the adjacent estuary to determine any breach effect that may be attributed to the realignment. This paper summarises the results from the vegetation, sedimentation and invertebrate monitoring and discusses the implications for other managed realignment schemes in the UK.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Meio Ambiente , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Agricultura , Animais , Inglaterra , Humanos , Invertebrados/crescimento & desenvolvimento , Desenvolvimento Vegetal , Formulação de Políticas
13.
Ann N Y Acad Sci ; 1051: 730-42, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16127013

RESUMO

5-Androsten-3beta, 17beta-diol (HE2100), and a synthetic analogue HE3204 are regarded as immune-regulating hormones, because both induce changes in the reporter antigen-popliteal lymph node assay (RA-PLNA). Mice were injected in the footpad with either HE2100 or HE3204 (0.01-3 mg), and a nonsensitizing dose of trinitrophenyl ovalbumin (TNP-OVA) was used as bystander reporter antigen. Seven days later, nodes were removed and numbers of cells (CD3, CD4, CD8, CD19; flow cytometry), TNP-specific IgM, IgG1, and IgG2a antibody-forming cells (AFCs; ELISPOT assay), and cytokines (interleukin-4 [IL-4], interferon-gamma [IFN-gamma]; ELISA) were measured. HE2100 and HE3204 increased cell numbers in a dose-dependent fashion. T (helper and suppressor) cells and B cells were increased (>5-fold). HE3204 was apparently twice as potent as HE2100. Both increased the B/T ratio (fivefold), increased TNP-specific IgM and IgG1 ( approximately 50-fold), and induced IgG2a AFCs. Both increased IL-4 and IFN-gamma secretion (up to threefold). Both displayed anti-inflammatory activity in the murine model of carrageenan-induced pleurisy, as evidenced by reduced neutrophil numbers and exudate volumes. Our observations suggest that both HE2100 and HE3204 are immune-regulating steroid hormones that exhibit anti-inflammatory properties. HE2100 (1 mg/mouse per day) provided significant benefit when given at disease onset in the SJL/J female mouse model of experimental autoimmune encephalomyelitis. These compounds and their analogues are candidates for further testing in autoimmune diseases.


Assuntos
Androstenodiol/uso terapêutico , Androstenóis/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Sequência de Aminoácidos , Androstenodiol/análogos & derivados , Androstenodiol/farmacologia , Androstenóis/farmacologia , Animais , Encefalomielite Autoimune Experimental/tratamento farmacológico , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Pleurisia/tratamento farmacológico , Choque Séptico/tratamento farmacológico
15.
AJR Am J Roentgenol ; 181(3): 775-80, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12933480

RESUMO

OBJECTIVE: The objective was to analyze enhancement characteristics of insulinomas and to determine the ability of multiphase CT to localize these tumors. MATERIALS AND METHODS: Prospective interpretations of multiphase helical CT scans were reviewed in 30 patients who had insulinomas resected over a 5-year period. CT scans were retrospectively reviewed to determine enhancement characteristics, tumor conspicuity in each phase of enhancement, and potential causes for false-negative findings. RESULTS: Sixty-three percent (19/30) of tumors were identified on CT prospectively. An additional six tumors were visualized in retrospect, allowing characterization of 25 (83%) of 30 tumors. Most tumors were hyperdense on at least one phase (n = 19), three tumors were hypoattenuating, and three were isodense and pedunculated. Insulinomas were most conspicuous on the early phase in 15 patients and in the portal venous phase in three. All tumors that underwent pancreatic phase imaging were seen (13/13), whereas three of 18 arterial and six of 25 portal venous phase findings were inconclusive for tumor. In the six examinations with false-negative findings in which the tumor could be seen in retrospect, two tumors were isodense and pedunculated, three were in close proximity to vessels, and one had a cystic appearance. CONCLUSION: Multiphasic CT has a moderate sensitivity in the detection of insulinomas. Most tumors are more conspicuous on the earlier phases of enhancement. The pancreatic phase may be more useful than the arterial phase. Potential sources of false-negative results include tumors adjacent to vessels, pedunculated morphology, or nonhyperattenuating lesions.


Assuntos
Insulinoma/diagnóstico por imagem , Triagem Multifásica , Neoplasias Pancreáticas/diagnóstico por imagem , Cuidados Pré-Operatórios , Tomografia Computadorizada Espiral , Adulto , Idoso , Idoso de 80 Anos ou mais , Reações Falso-Negativas , Feminino , Humanos , Insulinoma/cirurgia , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/cirurgia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
16.
Sci Total Environ ; 310(1-3): 231-6, 2003 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12812747

RESUMO

The effects of variation in climatic temperature on breeding behaviour and tadpole growth were investigated using data collected during a 22-year study of a single population of common toads, Bufo bufo, in southern England. Although the start of the breeding season each year, taken as the day when adult toads first arrived at their breeding pond in large numbers, showed no trend over time (1980-2001) it was highly correlated with climatic temperature. Thus, toads started breeding approximately 50 days earlier in the year following very mild winters (1993: February 2nd) compared with very cold ones (1986: March 23rd). Regression analysis of the relationship between the mean temperature of the 40 days immediately preceding the main arrival of toads at the breeding pond revealed that for every 1 degrees increase (or decrease) the toads arrived 12 days earlier (or later). Although the duration of the tadpole stage was longer when spawning was early, toadlets still emerged from the pond earlier than when spawning was late. The increased length of the tadpole stage, in years when spawning was early, was due to an increase in the proportion of cold days when the minimum ground temperature was at or below 0 degrees C. Thus, the tadpole stage was approximately 6 days longer (or shorter) for every 5% increase (or decrease) in the proportion of cold days the tadpoles were exposed to.


Assuntos
Bufo bufo/crescimento & desenvolvimento , Reprodução , Temperatura , Animais , Clima , Larva/crescimento & desenvolvimento , Dinâmica Populacional , Análise de Regressão , Fatores de Tempo
17.
AJR Am J Roentgenol ; 180(6): 1509-13, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12760910

RESUMO

OBJECTIVE: We performed a retrospective review of imaging-guided radiofrequency ablation of solid renal tumors. MATERIALS AND METHODS: Since May 2000, 35 tumors in 20 patients have been treated with radiofrequency ablation. The size range of treated tumors was 0.9-3.6 cm (mean, 1.7 cm). Reasons for patient referrals were a prior partial or total nephrectomy (nine patients), a comorbidity excluding nephrectomy or partial nephrectomy (10 patients), or a treatment alterative to nephron-sparing surgery (one patient who refused surgery). Tumors were classified as exophytic, intraparenchymal, or central. Sixteen patients had 31 lesions that showed serial growth on CT or MR imaging. Of these 16 patients, four patients with 10 lesions had a history of renal cell carcinoma, and two patients with 11 lesions had a history of von Hippel-Lindau disease. Four patients had incidental solid masses, two of which were biopsied and shown to represent renal cell carcinoma, and the remaining two masses were presumed malignant on the basis of imaging features. Successful ablation was regarded as any lesion showing less than 10 H of contrast enhancement on CT or no qualitative evidence of enhancement after IV gadolinium contrast-enhanced MR imaging. RESULTS: Of the 35 tumors, 22 were exophytic and 13 were intraparenchymal. Twenty-seven of the 35 were treated percutaneously using either sonography (n = 22) or CT (n = 5). Two patients had eight tumors treated intraoperatively using sonography. Patients were followed up with contrast-enhanced CT (n = 18), MR imaging (n = 5), or both (n = 5) with a follow-up range of 1-23 months (mean, 9 months). No residual or recurrent tumor and no major side effects were seen. CONCLUSION: Preliminary results with radiofrequency ablation of exophytic and intraparenchymal renal tumors are promising. Radiofrequency ablation is not associated with significant side effects. Further follow-up is necessary to determine the long-term efficacy of radiofrequency ablation.


Assuntos
Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/cirurgia , Ablação por Cateter , Neoplasias Renais/diagnóstico , Neoplasias Renais/cirurgia , Cirurgia Assistida por Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos , Fatores de Tempo , Tomografia Computadorizada por Raios X
18.
AJR Am J Roentgenol ; 178(3): 699-704, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11856701

RESUMO

OBJECTIVE: The objective of this study was to evaluate the technique, efficacy, and side effects of percutaneous ethanol injection in patients with limited cervical nodal metastases from papillary thyroid carcinoma. SUBJECTS AND METHODS: Fourteen patients who had undergone thyroidectomy for papillary thyroid carcinoma presented with limited nodal metastases (one to five involved nodes) in the neck between May 1993 and April 2000. All patients had received previous iodine-131 ablative therapy with a mean total dose per patient of 7,548 MBq. Ten of the patients either were considered poor surgical candidates or preferred not to have surgery, and all were unresponsive to iodine-131 therapy. Each metastatic lymph node was treated with percutaneous ethanol injection, and patients received both clinical and sonographic follow-up. RESULTS: Twenty-nine metastatic lymph nodes in our 14 patients were injected. Mean sonographic follow-up was 18 months (range, from 2 months to 6 years 5 months). All treated lymph nodes decreased in volume from a mean of 492 mm(3) before percutaneous ethanol injection to a mean volume of 76 mm(3) at 1 year and 20 mm(3) at 2 years after treatment. Six nodes were re-treated 2-12 months after initial percutaneous ethanol injection because of persistent flow on color Doppler sonography (n = 4), stable size (n = 1), or increased size (n = 1). Two patients developed four new metastatic nodes during the follow-up period that were amenable to percutaneous ethanol injection. Two patients developed innumerable metastatic nodes that precluded retreatment with percutaneous ethanol injection. No major complications occurred. All patients experienced long-term local control of metastatic lymph nodes treated by percutaneous ethanol injection. In 12 of 14 patients, percutaneous ethanol injection was successful in controlling all known metastatic adenopathy. CONCLUSION: Sonographically guided percutaneous ethanol injection is a valuable treatment option for patients with limited cervical nodal metastases from papillary thyroid cancer who are not amenable to further surgical or radioiodine therapy.


Assuntos
Carcinoma Papilar/secundário , Carcinoma Papilar/terapia , Etanol/administração & dosagem , Linfonodos , Metástase Linfática , Neoplasias da Glândula Tireoide/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/cirurgia , Feminino , Humanos , Injeções Intralesionais , Linfonodos/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Pescoço , Retratamento , Neoplasias da Glândula Tireoide/terapia , Tireoidectomia , Falha de Tratamento , Ultrassonografia Doppler em Cores , Ultrassonografia de Intervenção
19.
Ultrasound Q ; 18(1): 3-12, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12973053

RESUMO

Management and therapy of conditions of the thyroid, parathyroid glands, and cervical lymph nodes have evolved rapidly during the past 15 years. The development and continued improvement of high-resolution ultrasound (US) equipment, US-guided biopsy, and image-guided ablative techniques have fueled this change. These technical improvements and the knowledge and experience gained during this time have decreased the rate of unnecessary surgery in patients with thyroid nodules. They have also allowed more limited neck dissection in patients with parathyroid adenomas and have led to the development of US-guided ablative techniques that have eliminated the need for surgery in some cases. This article reviews the rationale and techniques of US-guided biopsy of the thyroid, parathyroid, and cervical lymph nodes. Established and evolving ablative techniques of these structures are also examined.

20.
Radiol Clin North Am ; 39(3): 415-28, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11506085

RESUMO

Ultrasound-guided intervention has enjoyed a period of unprecedented growth because its many advantages over other guidance modalities have been recognized. The decreased procedure time, increased accuracy, and safety of procedures performed under ultrasound guidance are of obvious benefit to radiologist and patient alike for all interventional applications. Lesions once considered unsafe to sample are now reasonably approached with ultrasound guidance. As equipment technology continues to improve and radiologists increasingly recognize the benefits of guiding procedures with ultrasound, the shift of procedures away from CT and fluoroscopic guidance will continue and ultrasound guidance will become the guidance method of choice for most interventional procedures.


Assuntos
Biópsia/métodos , Ultrassonografia de Intervenção/métodos , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/tratamento farmacológico , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/terapia
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