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1.
Nervenarzt ; 79(11): 1304, 1307-9, 2008 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-18958440

RESUMO

Bleeding complications during therapy with serotonin norepinephrine reuptake inhibitors are a well-known phenomenon. We report a patient who developed ecchymosis during administration of duloxetine. As a correlate we detected a transient platelet dysfunction. After converting to venlafaxine therapy, another antidepressant with a dual mechanism of action, the patient showed normal platelet function. We finally achieved remission of the episode.


Assuntos
Toxidermias/diagnóstico , Toxidermias/etiologia , Equimose/induzido quimicamente , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Tiofenos/efeitos adversos , Tiofenos/uso terapêutico , Cloridrato de Duloxetina , Equimose/diagnóstico , Feminino , Humanos , Adulto Jovem
2.
Heart ; 93(12): 1530-2, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18003685

RESUMO

Atherosclerotic renal artery stenosis (ARAS) is a growing dilemma. The condition is increasingly common and can promulgate hypertension and result in renal failure. However, patients with ARAS generally die owing to their coronaries or cerebral vessels. Intervention, by stenting or angioplasty is beloved and believed, but not proved. The American Heart Association has recently published guidelines regarding patients at high risk for ARAS who are potential candidates for revascularisation. Since this phraseology includes practically every patient with atherosclerosis, these guidelines appear ill advised.


Assuntos
Angioplastia com Balão/estatística & dados numéricos , Guias de Prática Clínica como Assunto , Obstrução da Artéria Renal/diagnóstico por imagem , Artéria Renal/diagnóstico por imagem , Angioplastia com Balão/métodos , Humanos , Radiografia , Obstrução da Artéria Renal/terapia
3.
J Pept Res ; 65(3): 395-410, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15787970

RESUMO

Native chemical ligation has proven to be a powerful method for the synthesis of small proteins and the semisynthesis of larger ones. The essential synthetic intermediates, which are C-terminal peptide thioesters, cannot survive the repetitive piperidine deprotection steps of N(alpha)-9-fluorenylmethoxycarbonyl (Fmoc) chemistry. Therefore, peptide scientists who prefer to not use N(alpha)-t-butyloxycarbonyl (Boc) chemistry need to adopt more esoteric strategies and tactics in order to integrate ligation approaches with Fmoc chemistry. In the present work, side-chain and backbone anchoring strategies have been used to prepare the required suitably (partially) protected and/or activated peptide intermediates spanning the length of bovine pancreatic trypsin inhibitor (BPTI). Three separate strategies for managing the critical N-terminal cysteine residue have been developed: (i) incorporation of N(alpha)-9-fluorenylmethoxycarbonyl-S-(N-methyl-N-phenylcarbamoyl)sulfenylcysteine [Fmoc-Cys(Snm)-OH], allowing creation of an otherwise fully protected resin-bound intermediate with N-terminal free Cys; (ii) incorporation of N(alpha)-9-fluorenylmethoxycarbonyl-S-triphenylmethylcysteine [Fmoc-Cys(Trt)-OH], generating a stable Fmoc-Cys(H)-peptide upon acidolytic cleavage; and (iii) incorporation of N(alpha)-t-butyloxycarbonyl-S-fluorenylmethylcysteine [Boc-Cys(Fm)-OH], generating a stable H-Cys(Fm)-peptide upon cleavage. In separate stages of these strategies, thioesters are established at the C-termini by selective deprotection and coupling steps carried out while peptides remain bound to the supports. Pilot native chemical ligations were pursued directly on-resin, as well as in solution after cleavage/purification.


Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Cisteína/química , Fluorenos/química , Fluorenos/síntese química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/síntese química , Sequência de Aminoácidos , Aprotinina/síntese química , Aprotinina/química , Dados de Sequência Molecular , Compostos de Enxofre/síntese química , Compostos de Enxofre/química
4.
Radiology ; 220(3): 751-6, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11526278

RESUMO

PURPOSE: To determine the hemodynamic significance of arteriographically detected renal arterial stenosis by obtaining pressure gradients with a miniaturized pressure guide wire. MATERIALS AND METHODS: Forty-six renal arterial stenoses in 38 patients were assessed in terms of severity and then subjected to gradient determination before and after angioplasty. The patients (mean age, 63 years) had a mean serum creatinine value of 1.3 mg/dL +/- 0.4 (114.9 micromol/L +/- 35.4 [SD]) and required on average three medications for blood pressure control. The mean degree of stenosis diameter was 51% +/- 17 (range, 12%-85%). RESULTS: The systolic and mean arterial pressure gradients with and those without vasodilatation were highly correlated with stenosis severity, systolic blood pressure, and serum creatinine as a curvilinear fit (r = 0.9, P <.01). At 50% stenosis severity, the mean pressure gradient was 22 mm Hg. CONCLUSION: Patients with a pressure gradient greater than 20 mm Hg should be good candidates for renal arterial dilatation, and use of the pressure guide wire will facilitate interventional decisions.


Assuntos
Pressão Sanguínea , Hemodinâmica , Obstrução da Artéria Renal/diagnóstico , Índice de Gravidade de Doença , Adulto , Idoso , Angioplastia , Creatinina/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Renal/patologia
5.
ScientificWorldJournal ; 1 Suppl 2: 728-36, 2001 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-12805824

RESUMO

Complex chemical, physical, and biological processes mediate nitrogen (N) transformations and movement during agricultural production, making the optimization of fertilizer use and environmental protection exceedingly difficult. Various computer models have been developed to simulate the site-specific fate and transport of N resulting from different crop production scenarios, but these models are very complex and difficult to use for most farmers, consultants, and conservationists. In an effort to facilitate access and simplify the use of sophisticated models, the U.S. Department of Agriculture (USDA) has developed an Internet-based nitrogen analysis tool. Based on the Nitrate Leaching and Economic Analysis Package (NLEAP), the Web site allows a user to conduct multiyear N simulation modeling specific to a crop field. Servers handle much of the required data assembly and formatting, thus sparing the user"s resources. Model runs are executed on the servers and the results are transmitted to the user. This new tool is presented along with early implementation results.


Assuntos
Agricultura/métodos , Agricultura/tendências , Simulação por Computador , Internet , Modelos Teóricos , Nitrogênio/análise , Clima , Gráficos por Computador , Bases de Dados Factuais , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , Fertilizantes , Modelos Biológicos , Modelos Químicos , Modelos Econômicos , Linguagens de Programação , Design de Software , Solo , Tempo , Estados Unidos , United States Department of Agriculture
6.
Z Kardiol ; 89(9): 747-53, 2000 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-11077683

RESUMO

To explore the relationship between coronary artery disease and renal vascular disease, we performed renal arterial angiography in 609 patients undergoing coronary angiography for suspected coronary artery disease. We defined renal artery stenosis as nonsignificant (< 40%), borderline (40-60%) and significant (> 60%). One-hundred fifty-two patients had renal artery stenosis, while 457 did not. Two-hundred and ten patients had no coronary disease; of these, only 9 had renal artery stenosis. On the other hand, the 143 patients with renal artery stenosis, when subdivided, had similar degrees of coronary disease; three vessel disease was significantly more common than one or two vessel disease in all groups. Renal artery stenosis of all severity degrees was associated with common atherosclerotic risk factors. However, hypertension was not a clue to the presence of renal artery stenosis. To evaluate the effect of percutaneous revascularization on hypertension and renal function all 51 patients with significant renal artery stenosis were treated by primary stent implantation and were followed up for 6 months. Stent implantation showed a marked decrease in systolic and diastolic blood pressure (163 +/- 30 to 145 +/- 17 and 93 +/- 18 to 83 +/- 10 mmHg; p = 0.008) with a decrease in the amount of antihypertensive medication but without beneficial effect on serum creatinine during follow-up (1.46 +/- 0.70 mg/dl to 1.39 +/- 0.58 mg/dl, p = ns). We conclude that renal artery stenosis of any severity is strongly suggestive of three vessel coronary artery disease. The fact that renal stenting lowers blood pressure decreases antihypertensive drugs and increases medication flexibility in patients with coronary artery disease would support the notion of revascularization in patients with significant stenoses.


Assuntos
Doença da Artéria Coronariana/epidemiologia , Hipertensão Renovascular/epidemiologia , Obstrução da Artéria Renal/epidemiologia , Idoso , Angiografia , Comorbidade , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/terapia , Feminino , Humanos , Hipertensão Renovascular/diagnóstico , Hipertensão Renovascular/terapia , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Obstrução da Artéria Renal/diagnóstico , Obstrução da Artéria Renal/terapia , Fatores de Risco , Stents
7.
Heart ; 84(3): 307-13, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10956297

RESUMO

OBJECTIVE: To evaluate the clinical and angiographic outcome in patients with in-stent restenosis in small coronary arteries and repeat target lesion revascularisation. DESIGN: Patients with in-stent restenosis in coronary arteries < or = 2.85 mm were eligible for the study and underwent target lesion revascularisation. Clinical and angiographic variables were assessed during a six month follow up period. RESULTS: 73 patients with 79 lesions were treated by percutaneous transluminal coronary angioplasty (47%), excimer laser angioplasty (25%), or restenting (28%). The mean (SD) reference diameter before target lesion revascularisation was 2.12 (0.5) mm. Procedural success was achieved in all cases, but 57% of the patients had restenosis after six months. The rate of further restenosis was higher with laser angioplasty (78%) than with restenting (47%) or balloon angioplasty alone (49%, p < 0.05). CONCLUSIONS: Treatment for in-stent restenosis in small coronary arteries is feasible and safe, with a second restenosis rate comparable to large coronary artery series. The strategy of target lesion revascularisation influences further in-stent restenosis, with an increased rate with laser angioplasty compared with restenting and repeat dilatation alone.


Assuntos
Angioplastia Coronária com Balão , Angioplastia com Balão a Laser , Doença das Coronárias/terapia , Stents , Idoso , Análise de Variância , Distribuição de Qui-Quadrado , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Microcirculação , Pessoa de Meia-Idade , Recidiva , Reoperação
8.
Radiology ; 214(1): 127-31, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10644111

RESUMO

PURPOSE: To assess the effectiveness and safety of endovascular covered stents in the management of pseudoaneurysms and arteriovenous fistulas after cardiac and vascular catheterization. MATERIALS AND METHODS: Twenty-six endovascular covered stents were used to repair 16 pseudoaneurysms, nine arteriovenous fistulas, and one combined lesion after femoral arterial puncture for diagnostic coronary angiography and/or angioplasty. Fistulas and aneurysms were in the superficial femoral artery in 16 cases, in the deep femoral artery in six cases, and in the common femoral artery in four cases. Implantation was performed from the opposite femoral artery in most cases. It was not possible to treat three additional cases transcutaneously for technical reasons (three of 29 cases). RESULTS: Percutaneous closure of the lesions with an endovascular covered stent was successful in 26 of 29 cases. Initial follow-up showed good stent patency. Two major complications were observed after stent implantation. During follow-up (about 1 year in 23 of 26 patients [88%]), stent thromboses were detected in four of 23 patients (17%) with follow-up color duplex flow imaging. CONCLUSION: Implantation of endovascular covered stents is an effective and safe method for the percutaneous closure of pseudoaneurysms and arteriovenous fistulas. Thus, endoluminal vascular repair with covered stents offers an alternative therapeutic approach to vascular surgery in selected patients.


Assuntos
Falso Aneurisma/terapia , Angioplastia Coronária com Balão/instrumentação , Fístula Arteriovenosa/terapia , Implante de Prótese Vascular , Angiografia Coronária/instrumentação , Artéria Femoral/lesões , Stents , Idoso , Idoso de 80 Anos ou mais , Falso Aneurisma/diagnóstico , Fístula Arteriovenosa/diagnóstico , Segurança de Equipamentos , Feminino , Seguimentos , Oclusão de Enxerto Vascular/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
9.
Catheter Cardiovasc Interv ; 47(2): 157-64, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10376495

RESUMO

Development of femoral artery pseudoaneurysms and arteriovenous fistulas represents a continuing problem after vascular diagnostic and interventional procedures. For most patients, ultrasound-guided compression is an effective method of treating such complications. However, in patients requiring a continuous anticoagulant regimen, in those with large arteriovenous fistulas or in patients suffering from painful groin hematomas, compression repair is less successful. We therefore assessed the feasibility, efficacy, and long-term results of interventional percutaneous treatment of these complications. In a 40-month period, we treated 53 consecutive patients with 30 pseudoaneurysms, 21 arteriovenous fistulas, and 2 combined lesions. The intervention was successful in 47 patients: 32 lesions were treated by implantation of covered stents, 14 by embolization techniques, and 1 by a combined procedure, surgical repair being necessary only in 6 patients. After a clinical and ultrasonic follow-up of 301 +/- 280 days, we noticed four late stent occlusions, especially in patients with poor peripheral runoff. Lesions with a distinct connection channel to the vessel lumen should be treated by coil embolization. In lesions originating from the femoral bifurcation with a broad base, surgical repair is necessary. Stenting of the superficial femoral artery with poor runoff should be avoided. Our results suggests that percutaneous closure of false aneurysms and arteriovenous fistulas after invasive procedures with unsuccessful ultrasonic compression repair is an attractive alternative to surgical treatment.


Assuntos
Falso Aneurisma/terapia , Angioplastia com Balão/efeitos adversos , Fístula Arteriovenosa/terapia , Cateterismo Cardíaco/efeitos adversos , Angiografia Coronária/efeitos adversos , Embolização Terapêutica , Stents , Idoso , Idoso de 80 Anos ou mais , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/etiologia , Angioplastia Coronária com Balão/efeitos adversos , Fístula Arteriovenosa/diagnóstico por imagem , Fístula Arteriovenosa/etiologia , Constrição , Cianoacrilatos/uso terapêutico , Feminino , Artéria Femoral/fisiologia , Humanos , Doença Iatrogênica , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Resultado do Tratamento , Ultrassonografia de Intervenção
10.
J Mol Med (Berl) ; 77(2): 294-8, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10023782

RESUMO

Studies on smooth muscle cell differentiation and those on vascular development in mouse and humans have long been hampered by the lack of suitable markers. Here we describe a novel, large isoform of smoothelin, a structural protein of differentiated, contractile smooth muscle cells. The protein, which is highly conserved in mouse and humans, shows homology with other cytoskeleton-associated smooth muscle cell proteins and contains an actinin-type actin-binding domain. Northern blot analysis from various mouse organs identified short and long smoothelin mRNA forms, which exhibit distinct tissue expression patterns. The short form is highly expressed in visceral muscle tissues such as intestine and stomach and is not detectable in brain, while the long mRNA form is expressed in all vascularized organs. These results may provide new tools and approaches to study both smooth muscle cell differentiation and proliferative vascular disease.


Assuntos
Diferenciação Celular/fisiologia , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Liso/citologia , Músculo Liso/metabolismo , Actinina/metabolismo , Actinas/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Biomarcadores , Clonagem Molecular , Sequência Conservada , Proteínas do Citoesqueleto/química , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Dados de Sequência Molecular , Peso Molecular , Proteínas Musculares/química , Especificidade de Órgãos , Isoformas de Proteínas , Homologia de Sequência de Aminoácidos
11.
Thromb Haemost ; 82 Suppl 1: 176-80, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10695512

RESUMO

Patients with concomitant cardiac and cerebrovascular disease undergoing revascularization procedures are at high risk of both, cardiac and cerebrovascular complications. The purpose of our study was to evaluate the feasibility of prior elective carotid artery stenting as an alternative treatment procedure to carotid endarterectomy (CEA) in patients with concomitant coronary artery disease (CAD), who clearly needed coronary revascularization. We offered extracranial internal carotid stenting to 85 patients with 89 significant carotid stenoses. Out of these, 19 patients were symptomatic. The quantitative mean reduction in diameter was 77 +/- 11%. Stent implantation was successful in 88 lesions. Two disabling major and 3 reversible minor strokes occurred periprocedurally. Three patients showed asymptomatic restenosis and stent deformation was detected in 2 patients. Based on this experience, carotid stenting in high risk patients with severe coronary artery disease is feasible and safe and might be indicated as an alternative procedure for combined surgery.


Assuntos
Estenose das Carótidas/cirurgia , Doença das Coronárias/cirurgia , Endarterectomia das Carótidas , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/fisiopatologia , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
13.
Eur Heart J ; 19(9): 1365-70, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9792262

RESUMO

AIMS: To evaluate the feasibility and safety of elective carotid stent implantation in patients with carotid stenoses and concomitant coronary artery disease, as an alternative to combined carotid and coronary surgery. METHODS: We treated 50 patients with >70%, stenoses in 53 carotid arteries with balloon angioplasty followed by elective stent implantation. All patients had severe coronary artery disease, and/or mitral insufficiency, aortic stenosis, rhythm disorders or generalized arteriosclerosis. In three patients the opposite carotid artery was occluded; nine patients had bilateral stenoses of which two received stents bilaterally. RESULTS: Fifty-six successful stent implantations (42 Wallstents, eight BeStents, two AVE-Microstents, one Palmaz Schatz stent, three Sito stents) were performed, reducing the baseline percent stenosis from 78 +/- 18%, to 13 +/- 11%. Complications included three transient ischaemic attacks, one minor and one major stroke. Follow-up was available for 46 patients over a mean of 10 months. Three asymptomatic restenoses and one deformation of a BeStent occurred. CONCLUSION: Our preliminary results indicate that carotid artery stenting in patients with concomitant severe coronary artery disease is feasible, safe, and may be an alternative to combined carotid and coronary surgery.


Assuntos
Angioplastia com Balão/instrumentação , Estenose das Carótidas/terapia , Doença das Coronárias/terapia , Stents , Idoso , Idoso de 80 Anos ou mais , Angiografia , Angioplastia com Balão/métodos , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Ponte de Artéria Coronária , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/cirurgia , Procedimentos Cirúrgicos Eletivos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Resultado do Tratamento
14.
Cathet Cardiovasc Diagn ; 45(1): 1-8, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9736342

RESUMO

To test the utility of endoprosthetic treatment for ostial renal artery stenosis, and to examine blood pressure and its treatment, serum creatinine, and restenosis rate, 44 ostial renal stent placements were performed in 30 patients with concomitant coronary artery disease, arterial hypertension, and the indication for angiotensin converting enzyme (ACE) therapy. There was a marked decrease in systolic and diastolic blood pressure (163+/-30 to 145+/-17 and 93+/-18 to 83+/-10 mm Hg; P < 0.008) with a decrease in number of medication (3.2+/-0.9 to 2.8+/-1.0; P = 0.005). In 5 out of 8 patients not receiving an ACE inhibitor, this drug could be added. Serum creatinine changed from 1.46+/-0.7 mg/dl to 1.39+/-0.58 mg/dl (P = ns). Three patients showed restenosis (12.5%). Ostial stenting lowers blood pressure, decreases antihypertensive drugs and increases medication flexibility.


Assuntos
Arteriosclerose/terapia , Doença da Artéria Coronariana/terapia , Obstrução da Artéria Renal/terapia , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Arteriosclerose/diagnóstico , Terapia Combinada , Doença da Artéria Coronariana/diagnóstico , Creatinina/sangue , Feminino , Humanos , Hipertensão Renovascular/diagnóstico , Hipertensão Renovascular/terapia , Masculino , Pessoa de Meia-Idade , Recidiva , Obstrução da Artéria Renal/diagnóstico , Resultado do Tratamento
15.
Am J Cardiol ; 80(11): 1478-81, 1997 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9399727

RESUMO

This study analyzes the severity of coronary artery disease in terms of the severity of renal artery disease in 609 patients undergoing coronary and renal angiography. The presence of renal artery disease of any severity is strongly suggestive of advanced coronary artery disease.


Assuntos
Arteriosclerose/complicações , Doença das Coronárias/complicações , Vasos Coronários , Obstrução da Artéria Renal/complicações , Artéria Renal , Angiografia , Arteriosclerose/diagnóstico , Doença das Coronárias/diagnóstico , Doença das Coronárias/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Obstrução da Artéria Renal/diagnóstico , Fatores de Risco , Índice de Gravidade de Doença , Ultrassonografia Doppler
16.
AJR Am J Roentgenol ; 169(2): 429-32, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9242747

RESUMO

OBJECTIVE: The purpose of this study was to determine the feasibility of using Wallstent implantation to treat superior vena cava syndrome due to malignant tumors. SUBJECTS AND METHODS: Digital subtraction angiography showed obstruction of the superior vena cava in 13 patients who then underwent transluminal dilatation and Wallstent implantation. The patients were treated with IV heparin and monitored in the emergency department. Thereafter, they were treated with a platelet inhibitor for 4 weeks. RESULTS: Because their signs and symptoms improved, patients were able to resume radiation therapy, chemotherapy, or both. One patient died of cardiac arrhythmia 1 day after stent placement. Although eight patients have subsequently died of their bronchial or thyroid gland tumors, superior vena cava syndrome did not recur in any patient. CONCLUSION: Percutaneous implantation of Wallstent endoprostheses provides excellent palliation for superior vena cava syndrome.


Assuntos
Stents , Síndrome da Veia Cava Superior/terapia , Idoso , Angiografia Digital , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Paliativos , Radiografia Intervencionista , Síndrome da Veia Cava Superior/diagnóstico por imagem , Síndrome da Veia Cava Superior/etiologia , Neoplasias Torácicas/complicações
18.
Appl Ergon ; 26(2): 109-16, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15677007

RESUMO

This study was conducted to evaluate the effect of an intelligent seat system, a microprocessor-based interactive seat that automatically adjusts itself to fit a seated individual by making pressure-sensitive adjustments on its own. First, a standard American automobile seat ('baseline' seat) was assessed for comfort. Subjective ratings of comfort, pressure distribution and seated anthropometric measurements were recorded for 20 test subjects. These measurements were recorded while the subjects maintained a simulated driving position in a seat buck. The comfort scale was based on a rating of 1 to 10, with 1 corresponding to 'very poor' and 10 corresponding to 'very good.' Based on a nonlinear, multiple regression model that had been previously developed, the comfort rating of the seat was predicted based on the subjective ratings and the recorded values of 450 pressure measurements from 20 subjects. The predicted comfort value was 7.46 for the baseline seat. Following the baseline assessment, the intelligent seat system was installed into the standard American automobile seat. The objective and subjective assessments were then repeated for 17 subjects and the new predicted comfort rating was 8.06. A t-test performed on the subjective and objective measures indicated that this was a significant improvement in seat comfort. Overall, subjects felt the self-adjusting seat was more customized and more comfortable, providing a better fit.

19.
Echocardiography ; 11(5): 523-33, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10150628

RESUMO

Because of its central position within the thorax, the heart can be encroached upon by masses originating in either anterior, posterior, or superior mediastinum. A distinction may be made between (A) Encroachment: distortion or partial displacement of one or more cardiac chambers by a contiguous mediastinal mass, without adverse hemodynamic effects, and (B) Compression: resulting in clinical manifestations similar to tamponade. Transthoracic and, recently, transesophageal echocardiography have been found useful in detecting mediastinal masses, the information obtained being complementary or preliminary to more complete imaging by CT or MRI. Anterior masses tend to compress the right heart chambers; posterior masses impinge on or compress the left atrium or ventricle, particularly the former. The wide variety of echographic appearances are briefly reviewed. Recently TEE has made it possible to diagnose masses obstructing the superior vena cava or pulmonary veins. A common, though little known, type of posterior mediastinal encroachment that echocardiographers need to be aware of is that of abnormal esophageal/gastric masses including hiatus hernia and esophageal carcinoma, which have typical two-dimensional echo features and may sometimes simulate left atrial masses.


Assuntos
Ecocardiografia , Neoplasias do Mediastino/diagnóstico por imagem , Humanos , Miocárdio/patologia
20.
Am J Hypertens ; 7(5): 425-8, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8060575

RESUMO

Left ventricular mass calculations are often performed to assess the need or effectiveness of antihypertensive drug therapy. However, there are multiple potential errors that may affect the accuracy of these calculations, which can possibly include acute changes in preload. Therefore, to assess the hypothesis that acute volume depletion might alter calculated left ventricular mass, 15 normotensive healthy male volunteers underwent standard M-mode echocardiographic evaluations (at the level of the chordae tendineae guided by two-dimensional echocardiography) before and 2 h after 40 mg of intravenous furosemide. One patient was eliminated due to hypotension prior to the final echocardiogram. The echocardiograms were blinded to patient identity and the time sequence and read separately by two investigators. Four to five cycles were read per echocardiogram by each investigator. All values measured were the mean of the two investigators. Echocardiographic measurements were derived by both the American Society of Echocardiography and Penn conventions. An average urine volume of 1728 mL was collected, and the mean weight change 2 h after furosemide administration was 1.78 kg (P = .001). Penn left ventricular diastolic diameter (1.8 mm, P = .015) and left ventricular mass index (10 g/m2, P = .04) were significantly decreased; however, there was no significant change in septal, posterior, or relative wall thicknesses. As it is unreasonable to believe that acute remodeling of the left ventricle resulted in a decline in left ventricular mass in 2 hours, it is concluded that acute volume changes resulted in a decrease in left ventricular mass measurement due to the influence of diastolic diameter on the calculation of cardiac mass.


Assuntos
Volume Sanguíneo/efeitos dos fármacos , Ecocardiografia , Furosemida/farmacologia , Coração/efeitos dos fármacos , Diurese/efeitos dos fármacos , Ventrículos do Coração , Humanos , Injeções Intravenosas , Masculino , Estudos Prospectivos , Fatores de Tempo
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