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2.
Anaesthesia ; 66(6): 472-80, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21457152

RESUMO

In a randomised trial, we compared the effects of oral sildenafil (0.5 mg.kg(-1) ) and placebo, administered the day before cardiac surgery, in 24 children. In sildenafil vs placebo patients, pre-cardiopulmonary bypass median (IQR [range]) cyclic-guanosine-monophosphate was not significantly different (29.9 (2.1-208.1 [0.5-391.5]) vs 5.2 (0.3-54.6 [0-628.9]) pmol.ml(-1) , respectively). Post-cardiopulmonary bypass, nitrate/nitrite levels were also not significantly different (0.7 (0-8.0 [0-142.8]) vs 0 (0-2.7 [0-52.7]) µM, respectively). Postoperatively, mean (SD) pulmonary vascular resistance (2.64 (2.28) vs 1.90 (1.12) WU.m(-2) , respectively and oxygenation index (5.29 (4.60) vs 3.38 (2.54), respectively) remained unchanged, whilst oxygen delivery (57.18 (21.24) vs 74.13 (35.46) ml.min(-1) .m(-2) , respectively) and bi-ventricular systolic function (left ventricle 3.78 (0.94) vs 4.55 (1.08) cm.s(-1) , respectively; p=0.002; right ventricle 6.93 (1.47) vs 8.09 (2.25) cm.s(-1) , respectively; p<0.001) were significantly reduced in the sildenafil group. In this trial, pre-operative sildenafil did not affect postoperative pulmonary vascular resistance. There was, however, a negative impact on ventricular function and oxygenation.


Assuntos
Ponte Cardiopulmonar/efeitos adversos , Defeitos dos Septos Cardíacos/cirurgia , Hipertensão Pulmonar/prevenção & controle , Piperazinas/uso terapêutico , Sulfonas/uso terapêutico , Vasodilatadores/uso terapêutico , Administração Oral , Pré-Escolar , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/fisiopatologia , Lactente , Masculino , Oxigenoterapia , Piperazinas/administração & dosagem , Cuidados Pós-Operatórios/métodos , Cuidados Pré-Operatórios/métodos , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/fisiopatologia , Purinas/administração & dosagem , Purinas/uso terapêutico , Citrato de Sildenafila , Sulfonas/administração & dosagem , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Função Ventricular Esquerda/efeitos dos fármacos , Função Ventricular Direita/efeitos dos fármacos
3.
Acta Psychol (Amst) ; 198: 102836, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31279183

RESUMO

An altered sense of the experience of time represents one of the nine dimensions that is conceived as characterizing a state of flow. While a number of other factors necessarily contribute to this overall experience of flow, subjective time perception is of particular quantitative interest and thus serves as the focus of the present meta-analysis. The extant body of relevant quantitative research was evaluated to identify data relating to both flow and change in the sense of time. Sixty-three (n = 63) articles were determined to qualify under the current specified inclusion criteria. These sixty-three studies yielded one thousand and ninety-four (n = 1094) effect sizes. All studies included in the meta-analysis were also coded for relevant moderator variables. Results indicated moderately positive correlations between affective, consciousness, and performance based aspects of flow (r = 0.4, 0.21, 0.17 respectively), thus reinforcing the original conceptualization of their relationship for the generation and maintenance of the flow state. Additionally, variations in environmental conditions (both physical and social) were found to have differential effects on the overall level of experienced flow. The results of this meta-analysis also serve to inform the process of further model development that can more accurately quantify and predict temporal perception as one metric of flow.


Assuntos
Percepção do Tempo , Afeto , Estado de Consciência , Humanos , Pensamento
4.
Ultramicroscopy ; 156: 1-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25957734

RESUMO

An approach towards experiment design and optimisation is proposed for achieving improved accuracy of ADF STEM quantification. In particular, improved robustness to small sample mis-tilts can be achieved by optimising detector collection and probe convergence angles. A decrease in cross section is seen for tilted samples due to the reduction in channelling, resulting in a quantification error, if this is not taken into account. At a smaller detector collection angle the increased contribution from elastic scattering, which initially increases with tilt, can be used to offset the decrease in the TDS signal.

5.
Ultramicroscopy ; 151: 56-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25511931

RESUMO

Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations.

6.
Ann Thorac Surg ; 62(3): 877-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8784024

RESUMO

We present 2 cases of failed coronary angioplasty, with hemodynamic compromise, where emergency coronary artery bypass grafting was performed without cardiopulmonary bypass. The hypodynamic nature of the stunned myocardium in this circumstance allows this technique to be applied with relative ease to accessible vessels. As a consequence, reduced morbidity and hospital stay can be anticipated.


Assuntos
Ponte de Artéria Coronária , Idoso , Angina Instável/cirurgia , Angina Instável/terapia , Angioplastia Coronária com Balão , Emergências , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Tratamento
7.
Ann Thorac Surg ; 59(6): 1588-9, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7771855

RESUMO

We present a single pericardial patch repair of the sinus venosus defect with anomalously connected pulmonary veins, incorporating enlargement of the superior vena cava. In our small series to date this procedure has been carried out without morbidity or mortality. Noninvasive follow-up by echocardiography and electrocardiography, over the short term, has not detected any stenosis of the venous pathways or sinus node dysfunction.


Assuntos
Comunicação Interatrial/cirurgia , Pericárdio/transplante , Veia Cava Superior/cirurgia , Ecocardiografia , Eletrocardiografia , Seguimentos , Comunicação Interatrial/diagnóstico , Humanos , Técnicas de Sutura
8.
Ann Thorac Surg ; 62(2): 538-42, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8694619

RESUMO

BACKGROUND: Cardiopulmonary bypass induces a systemic inflammatory response. This study investigated, in a pediatric population, cytokine-induced responses and their potential modification by intraoperative steroid administration. METHODS: Markers of the acute-phase response were measured perioperatively in 24 children weighing less than 10 kg undergoing cardiac operations. Those having operations with cardiopulmonary bypass were randomized to receive either no steroid (group I, n = 8) or 10 mg/kg methylprednisolone in the pump prime (group II, n = 10); patients undergoing nonbypass procedures were controls (group III, n = 6). RESULTS: In all groups, plasma interleukin-6 level was elevated (p < 0.01) above baseline throughout the post-operative period, peaking earlier in group I. Levels of C-reactive protein peaked at 48 hours, and postoperative core temperature was raised in all groups. Levels of interleukin-6 from 2 to 6 hours and C-reactive protein at 24 hours postoperatively were greater (p < 0.05) in group I than in group II. Maximum interleukin-6 level, C-reactive protein level, and temperature were all significantly greater in group I than in group III. Maximum interleukin-6 level correlated with maximum C-reactive protein level in group I only (rs = 0.76; p < 0.05) and showed no association with temperature. Duration of bypass did not correlate with levels of interleukin-6. CONCLUSIONS: This study demonstrated a marked acute-phase response to operation; the greater response to procedures with cardiopulmonary bypass was abrogated by intraoperative steroid administration. The importance of interleukin-6 as an inducer of acute phase proteins after bypass is supported by its association with C-reactive protein levels, but other factors must be important in the induction of pyrexia.


Assuntos
Reação de Fase Aguda/etiologia , Peso Corporal , Ponte Cardiopulmonar/efeitos adversos , Reação de Fase Aguda/prevenção & controle , Temperatura Corporal/efeitos dos fármacos , Proteína C-Reativa/análise , Citocinas/análise , Comunicação Atrioventricular/cirurgia , Febre/etiologia , Febre/prevenção & controle , Cardiopatias Congênitas/cirurgia , Defeitos dos Septos Cardíacos/cirurgia , Humanos , Lactente , Recém-Nascido , Interleucina-6/sangue , Cuidados Intraoperatórios , Metilprednisolona/administração & dosagem , Metilprednisolona/uso terapêutico , Artéria Pulmonar/anormalidades , Artéria Pulmonar/cirurgia , Veias Pulmonares/anormalidades , Veias Pulmonares/cirurgia , Toracotomia , Fatores de Tempo
9.
Semin Thorac Cardiovasc Surg ; 13(4 Suppl 1): 48-54, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11805949

RESUMO

The superior performance of stentless aortic valves with improved left ventricular hypertrophy regression and greater effective orifice area is proven. The Aortech Elan stentless valve (AESV) is a glutraldehyde preserved porcine valve with a pericardial reinforced inflow tract and a scalloped outflow to reduce bulk. We present the early results of AESV implantation at our institution. The first 41 consecutive recipients of the AESV at our unit, between November 1999 and December 2000, were studied. Mean preoperative New York Heart Association functional class (NYHA) status was 3.00 +/- 0.1. Patients requiring a bioprosthesis with suitable anatomy routinely received this implant. The AESV was implanted, either with an interrupted or continuous suture to the inflow tract and a continuous suture to the outflow tract. Transthoracic echocardiography was performed at 6 to 9 weeks after surgery, and aortic transvalvular gradients, flow velocities, and effective orifice areas (EOA) were calculated. In the early postoperative period, two patients with coronary artery disease died of low cardiac output. Echocardiography demonstrated competent valves. At follow-up, one patient was shown to have mild to moderate perivalvular leak with minimal symptoms. Two patients with aortic regurgitation secondary to bacterial endocarditis had no evidence of infection at 3 months after surgery. Mean transvalvular gradient was 6.91 +/- 0.87 mm Hg and mean effective orifice area was 1.18 +/- 0.04 cm(2)/m(2) at a mean of 8.4 weeks after surgery. AESV recipients for native aortic endocarditis were free from infection and regurgitation. The Elan stentless aortic valve demonstrates excellent early hemodynamic results, with very low transvalvular gradients, good flow characteristics and low regurgitation incidence. Ease of implantation is evidenced by favorable ischemic times. This valve may offer an option to homograft in acute aortic endocarditis. Long-term results are awaited.


Assuntos
Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Bioprótese , Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia Transesofagiana , Feminino , Seguimentos , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Desenho de Prótese
10.
Semin Thorac Cardiovasc Surg ; 11(4 Suppl 1): 93-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10660174

RESUMO

A randomized prospective trial was undertaken to compare the hemodynamic performance and left ventricular regression after aortic valve replacement with the Toronto SPV stentless bioprosthesis and the Carpentier Edwards SAV (CE) bioprosthesis. Forty patients were randomized after the annular and sinotubular diameters had been measured. Early hemodynamic measurements were made with a thermodilution cardiac output catheter, and echocardiography was used thereafter. Left ventricular mass was assessed using magnetic resonance imaging (MRI) at 1 week, 6 months, and 32 months. The mean annular size was 25.3+/-2.2 mm (CE) and 25.5+/-1.5 mm (Toronto), although it was possible to implant valves with a mean diameter 3 mm larger in the stentless group (26.0+/-1.7 mm cf. 23.0+/-1.7 mm). Hemodynamic performance in the first 24 hours showed no significant difference between the groups, but there was a trend for shorter ventilation time and shorter stays in the intensive therapy unit in the stentless group. Echocardiography showed superior transvalvular gradients in the stentless group at 1 week (mean 5.5+/-3.1 mm Hg cf. 8.9+/-2.5 mm Hg), and this difference was maintained at a mean follow-up time of 32 months (3.5+/-0.6 mm Hg cf. 6.3+/-0.6 mm Hg). Similar regression of left ventricular mass was seen in both groups at 6 months, but at 32 months, measurement in diastole showed a reduction of 38% (P<.01) in the stentless group compared with 20% (P = ns) in the stented group, and measurements in systole showed a 23% (P<.01) and 13% (P = ns) reduction, respectively. This study confirms that a larger stentless valve can be implanted into a given size of aortic annulus with superior residual aortic valve gradients. These lower gradients seem to result in improved long-term regression of left ventricular mass as measured by MRI.


Assuntos
Valva Aórtica/cirurgia , Bioprótese , Próteses Valvulares Cardíacas , Stents , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/patologia , Doenças das Valvas Cardíacas/cirurgia , Hemodinâmica , Humanos , Imageamento por Ressonância Magnética , Masculino , Desenho de Prótese , Fatores de Tempo , Ultrassonografia
11.
Semin Thorac Cardiovasc Surg ; 13(4 Suppl 1): 168-72, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11805967

RESUMO

Stentless valves in the aortic position have been shown to have superior hemodynamic performance to stented valves and have now been shown to increase survival. We report the medium-term results from a single center of 229 Toronto (SPV) aortic valve replacements between 1994 and 2000. The mean age of the patients was 72 years (range, 41-87 years). The mean Euroscores were 6.2 (+/-0.13) and Parsonnet scores of 16.8 (+/-0.5). Concomitant coronary artery bypass grafting was performed in 125 (55%) of patients, eight patients had additional mitral valve replacements and ten were redo procedures. Hospital mortality was 3.5%. The mean follow-up period was 45 (7-81) months. The actuarial survival was 92.4% (+/-1.4%) at one year and 76.2% (+/-3.5%) at five years. There were 37 late deaths (4.7% per patient years). There were 3 patients with prosthetic valve endocarditis (0.38% per patient years), two of whom died. Stroke occurred in 13 patients (1.6% per patient years), five of whom died. None of these events were known to be valve related. There was no incidence of structural valve dysfunction and no valves have been explanted. At follow-up, the mean transvalvular gradient was 4.2 mm Hg (range, 0.9-12.7 mm Hg). No aortic incompetence (AI) was seen in 88% of patients with trivial or mild AI in 11% of patients and moderate AI in one patient. This series shows acceptable early and medium-term results in an elderly population with a high incidence of coronary artery disease.


Assuntos
Valva Aórtica/cirurgia , Bioprótese/estatística & dados numéricos , Endocardite Bacteriana/etiologia , Próteses Valvulares Cardíacas/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ponte de Artéria Coronária , Doença da Artéria Coronariana/epidemiologia , Ecocardiografia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Reoperação , Staphylococcus aureus/isolamento & purificação , Taxa de Sobrevida
12.
Eur J Cardiothorac Surg ; 2(3): 143-50, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3272215

RESUMO

Between January 1977 and December 1986, 1606 Bjørk-Shiley tilting disc prostheses (BS) and 1346 Carpentier Edwards porcine prostheses (CE) were implanted in 1300 and 1156 patients, respectively, at the same institution. During the time of implantation, both valves have developed: the BS through standard disc and convexo-concave to monostrut, and the CE valves from standard to supra-annular. Newer valve types were used where applicable as they became available. Preoperative status in respect of age and cardiac rhythm were similar. There were significantly more females (64% BS: 54% CE, P less than 0.001); worse NYHA grade (74% Grade 111 and IV-BS: 56% 111 and IV-CE, P less than 0.001) more closed heart surgery (26% BS: 18% CE, P less than 0.001) and more previous open heart surgery (11.6% BS: 8.9% CE, P less than 0.001) in the BS group. All BS patients were anticoagulated and 49% of mitral CE patients and 7% of aortic CE patients were anticoagulated. There was no significant difference between the two groups in hospital mortality (BS 7.2%: CE 6.3%), late mortality (BS 2.5%/patient year: CE 3.2%/patient year) overall incidence of systemic embolism (BS 1.3%/patient year: CE 1.4/patient year), prosthetic valve endocarditis (BS 0.7%/patient year: CE 0.9%/patient year), valve failure (BS 0.5%/patient year: CE 0.9%/patient year) or peri-prosthetic leak (BS 1.2%/patient year: CE 1.3%/patient year). The incidence of systemic embolism in the aortic position was lower with the BS prosthesis (BS 0.2%/patient year: CE 1.2%/patient year, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Bioprótese , Próteses Valvulares Cardíacas , Adolescente , Adulto , Idoso , Anticoagulantes/efeitos adversos , Bioprótese/efeitos adversos , Criança , Pré-Escolar , Embolia/epidemiologia , Embolia/etiologia , Endocardite/etiologia , Feminino , Seguimentos , Próteses Valvulares Cardíacas/efeitos adversos , Próteses Valvulares Cardíacas/mortalidade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Falha de Prótese , Reoperação , Taxa de Sobrevida
13.
Ann Thorac Cardiovasc Surg ; 4(3): 138-45, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9660911

RESUMO

In the three year period from March 1994, 112 Toronto Stentless Porcine Valves (SPV TM) were implanted in the Western Infirmary, Glasgow. There were 55 males and 57 females aged between 45 and 86 years (mean 70.9 +/- 7.2 yrs). The mean preoperative aortic gradient was 89 +/- 27 mmHg. Fifty-three patients (47%) had an isolated first time aortic valve replacement. Myocardial revascularisation was carried out in 51 patients (46%) with a mean of 1.7 +/- 0.9 coronary bypass grafts per patient. Six patients (5.3%) had associated mitral valve procedures and six patients (5.3%) had previous open heart surgery. Four patients (3.6%) had a minimally invasive procedure. There was one perioperative death (0.9%) which was not valve related. Of the 111 survivors there were three late deaths (cerebrovascular accident at two months and congestive cardiac failure at two months and four months). Two patients developed prosthetic valve endocarditis at three and five months respectively, one requiring a repair of a periprosthetic leak. To compare the effects of stented and stentless prostheses on early haemodynamic function and late left ventricular mass regression, a prospective randomized clinical trial was conducted. Following valve sizing, 20 patients were randomized to receive a Carpentier-Edwards SAV stented bioprosthesis (mean annular size-25.3 mm, mean valve size-23 mm) of which eight also had bypass grafts. Twenty patients were randomized to receive a Toronto SPV (mean annular size-25.5 mm, mean valve size-26 mm) of which nine had bypass grafts. The stentless valve group had a longer ischaemic time (77.9 +/- 20.9 min v 60.9 +/- 21.9 min) and bypass time (101.7 +/- 27.1 min v 82.9 +/- 20.2 min). Using continuous cardiac output monitoring, no statistically significant differences were found in early haemodynamic indices although the stentless group required less inotropes and had a shorter ventilation time (16.1 +/- 4.2 hrs v 55.2 +/- 104.9 hrs) and intensive care stay (1.1 +/- 0.2 days v 4.6 +/- 8.3 days). Mean and peak aortic gradients one week postoperatively were lower in the stentless group (5.6 +/- 3 mmHg v 8.9 +/- 2.3 mmHg and 12.5 +/- 7.8 mmHg v 24.4 +/- 8.8 mmHg respectively). Magnetic resonance imaging at six months showed a 15% reduction in the end systolic muscle mass index in the stented group but a greater reduction of 29% in the stentless group. This study shows that despite requiring a more demanding technique of insertion, aortic valve replacement with the Toronto stentless porcine valve can produce satisfactory early clinical results.


Assuntos
Bioprótese , Doenças das Valvas Cardíacas/cirurgia , Próteses Valvulares Cardíacas , Idoso , Idoso de 80 Anos ou mais , Animais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/patologia , Valva Aórtica/cirurgia , Canadá , Ecocardiografia , Feminino , Seguimentos , Doenças das Valvas Cardíacas/diagnóstico , Implante de Prótese de Valva Cardíaca , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Revascularização Miocárdica , Estudos Retrospectivos , Stents , Suínos , Resultado do Tratamento
14.
J Hypertens Suppl ; 7(2): S51-5, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2666615

RESUMO

The renin inhibitor H77 and the angiotensin I converting enzyme (ACE) inhibitor captopril were compared in separate experiments with infusion of 5% dextrose as a control for the effects on plasma angiotensin II (Ang II) concentration, arterial pressure and cardiac function, measured by Swan-Ganz catheter, in conscious dogs. The effects of a high dose of H77 (10 mg/kg per h) were similar to those of high-dose captopril (6 mg/kg per h). Both reduced plasma Ang II concentration, systemic vascular resistance and arterial pressure; both increased the heart rate; both increased cardiac output but the change was significant only with captopril; neither affected stroke volume, pulmonary artery pressure or pulmonary vascular resistance; both reduced left and right atrial pressures. The similar pattern of effects for the two inhibitors suggests that the mechanism by which they act is the same--reduction in Ang II--and that the cardiovascular effects of H77 are not a specific action of the peptide that is unrelated to the reduction in plasma Ang II concentrations.


Assuntos
Angiotensina II/sangue , Pressão Sanguínea/efeitos dos fármacos , Captopril/farmacologia , Coração/efeitos dos fármacos , Oligopeptídeos/farmacologia , Renina/antagonistas & inibidores , Animais , Débito Cardíaco/efeitos dos fármacos , Cães , Coração/fisiopatologia , Masculino , Sódio/deficiência , Resistência Vascular/efeitos dos fármacos
15.
Ultramicroscopy ; 133: 109-19, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23969066

RESUMO

The physical basis for using a probe-position integrated cross section (PICS) for a single column of atoms as an effective way to compare simulation and experiment in high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) is described, and the use of PICS in order to make quantitative use of image intensities is evaluated. It is based upon the calibration of the detector and the measurement of scattered intensities. Due to the predominantly incoherent nature of HAADF STEM, it is found to be robust to parameters that affect probe size and shape such as defocus and source coherence. The main imaging parameter dependencies are on detector angle and accelerating voltage, which are well known. The robustness to variation in other parameters allows for a quantitative comparison of experimental data and simulation without the need to fit parameters. By demonstrating the application of the PICS to the chemical identification of single atoms in a heterogeneous catalyst and in thin, layered-materials, we explore some of the experimental considerations when using this approach.


Assuntos
Estudos Transversais/instrumentação , Estudos Transversais/métodos , Microscopia Eletrônica de Transmissão e Varredura/métodos
16.
J Dent Res ; 92(3): 222-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23315474

RESUMO

Tooth morphogenesis involves patterning through the activity of epithelial signaling centers that, among other molecules, secrete Sonic hedgehog (Shh). While it is known that Shh responding cells need intact primary cilia for signal transduction, the roles of individual cilia components for tooth morphogenesis are poorly understood. The clinical features of individuals with Ellis-van Creveld syndrome include various dental anomalies, and we show here that absence of the cilial protein Evc in mice causes various hypo- and hyperplasia defects during molar development. During first molar development, the response to Shh signaling is progressively lost in Evc-deficient embryos and, unexpectedly, the response consistently disappears in a buccal to lingual direction. The important role of Evc for establishing the buccal-lingual axis of the developing first molar is also supported by a displaced activity of the Wnt pathway in Evc mutants. The observed growth abnormalities eventually manifest in first molar microdontia, disruption of molar segmentation and symmetry, root fusions, and delayed differentiation. Analysis of our data indicates that both spatially and temporally disrupted activities of the Shh pathway are the primary cause for the variable dental anomalies seen in patients with Ellis-van Creveld syndrome or Weyers acrodental dysostosis.


Assuntos
Proteínas Hedgehog/fisiologia , Proteínas de Membrana/genética , Dente Molar/crescimento & desenvolvimento , Odontogênese/genética , Anormalidades Dentárias/genética , Erupção Dentária/fisiologia , Animais , Diferenciação Celular/genética , Proliferação de Células , Cílios , Processamento de Imagem Assistida por Computador , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Erupção Dentária/genética , Via de Sinalização Wnt/fisiologia
17.
Interact Cardiovasc Thorac Surg ; 3(2): 240-2, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17670224

RESUMO

We report the use of polymerase chain reaction for the diagnosis of prosthetic valve methicillin-resistant Staphylococcus aureus endocarditis in a patient with chronic liver disease where conventional laboratory testing failed. This case highlights the diagnostic and therapeutic potential of molecular techniques in the management of culture-negative endocarditis.

18.
Anaesthesia ; 39(3): 272-6, 1984 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6703299

RESUMO

We have assessed the performance of a new fibre-optic pulmonary artery catheter for the measurement of mixed venous oxygen saturation. The results obtained from this catheter compare well with those using standard techniques. Other information from the catheter allows oxygen consumption to be easily calculated and again the results obtained agree closely with those measured using standard techniques.


Assuntos
Cateteres de Demora , Cuidados Críticos , Oxigênio/sangue , Adulto , Tecnologia de Fibra Óptica , Humanos , Monitorização Fisiológica/instrumentação , Consumo de Oxigênio , Pressão Parcial , Artéria Pulmonar , Análise de Regressão , Choque Séptico/fisiopatologia
19.
Am Heart J ; 123(3): 698-703, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1531724

RESUMO

We have investigated the role of the lungs in the extraction of atrial natriuretic factor (ANF) by measuring plasma levels in samples taken from the central circulation in 12 patients (mean age 59 years; range 43 to 68) undergoing cardiac surgery. We also investigated the effects of cardiopulmonary bypass on ANF levels. ANF levels (mean +/- SD) were lower in pulmonary venous samples (41 +/- 20 pg/ml) than in pulmonary arterial samples (54 +/- 18 pg/ml; p less than 0.001), demonstrating 24% extraction of ANF by the lungs. Both left atrial (47 +/- 23 pg/ml) and systemic arterial levels (52 +/- 22 pg/ml) were higher than pulmonary venous levels (both p less than 0.05), indicating secretion of ANF into the left side of the heart. During cardiopulmonary bypass, plasma ANF concentration fell from 68 +/- 23 pg/ml before aortic cross-clamping to 35 +/- 13 pg/ml 10 minutes after and 28 +/- 9 40 minutes after the application of clamps (both p less than 0.001). A rebound rise to 122 +/- 33 pg/ml followed the release of the clamp (p less than 0.001). This study demonstrates that ANF is extracted by the lungs and secreted directly into the left side of the heart. The considerable fall in plasma levels that was observed during aortic cross-clamping might contribute to the neurohumoral activation and increased peripheral resistance observed after prolonged cardiopulmonary bypass and to the risk of renal ischemic injury.


Assuntos
Fator Natriurético Atrial/metabolismo , Ponte Cardiopulmonar , Pulmão/fisiologia , Função do Átrio Esquerdo/fisiologia , Fator Natriurético Atrial/sangue , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Função Ventricular Esquerda/fisiologia
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