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1.
Orthop Traumatol Surg Res ; 104(6): 787-791, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29555560

RESUMO

BACKGROUND: Reports of early glenoid wear after humeral resurfacing hemiarthroplasty have prompted the use, in combination with this procedure, of newly developed glenoid implants. This combination can increase global humeral offset. The objectives of this study were to assess changes in overall lateral offset and their potential short-term clinical consequences after combined humeral resurfacing and glenoid replacement. HYPOTHESIS: Combined humeral resurfacing and glenoid replacement induces a large increase in overall lateral offset, resulting in short-term clinical consequences. MATERIAL AND METHODS: A single-centre prospective study was started in November 2011. Consecutive patients scheduled for total shoulder arthroplasty with humeral resurfacing were included. The primary outcome measure was the change in lateral offset between radiographs obtained pre-operatively and 3 months post-operatively. The functional outcome assessed using the Constant score was compared between the groups with a lateral offset change <10mm vs. ≥10mm. RESULTS: From November 2011 to November 2014, 35 total shoulder arthroplasties with humeral resurfacing were performed in 32 patients with a mean age of 72.1 years (range, 55-86 years). Mean follow-up was 20±6 months (range, 12-31 months). Overall lateral offset was significantly greater post-operatively than pre-operatively (14±6mm vs. 5±7mm, p<0.0001), the mean difference being 8mm (range, 2-20mm). Post-operative range of motion was better in the group with an overall lateral offset ≥10mm (p=0.0016). DISCUSSION: Combined humeral resurfacing and glenoid replacement markedly increases overall lateral offset. This increase is not associated with adverse effects on short-term function and may improve post-operative motion range. However, greater lateral offset elevates the loads on the glenoid implant, which may increase the risk of glenoid implant loosening and rotator cuff tearing. Close radiological monitoring is therefore imperative. LEVEL OF EVIDENCE: IV, prospective cohort study.


Assuntos
Cavidade Glenoide/cirurgia , Hemiartroplastia , Cabeça do Úmero/cirurgia , Articulação do Ombro/cirurgia , Prótese de Ombro , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Substituição/métodos , Feminino , Seguimentos , Hemiartroplastia/efeitos adversos , Hemiartroplastia/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Radiografia , Amplitude de Movimento Articular , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/fisiopatologia
2.
Orthop Traumatol Surg Res ; 103(6): 891-897, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28733108

RESUMO

INTRODUCTION: Total elbow arthroplasty (TEA) is one option in distal humerus fracture in elderly osteoporotic patients. HYPOTHESIS: The study hypothesis was that, in patients aged 70years or more, TEA provides functional results and ranges of motion compatible with everyday activity, with a complications rate equal to or lower than with internal fixation, and no loss of autonomy or cognitive impairment. MATERIAL AND METHODS: In this retrospective study, 21 patients receiving TEA for distal humerus fracture were included. Mean follow-up was 3.2years, with functional (Quick DASH and MEPS), cognitive (MMSE), autonomy-related (ADL) and radiological assessment (Morrey). RESULTS: Mean MEPS was 84 and QuickDASH 32.4. Mean extension deficit was 22°, and mean flexion 125°. There was no loss of autonomy or cognitive impairment. The complications rate was 9.5%. There were no revision surgeries. DISCUSSION: TEA proved reliable in comminuted distal humerus fracture in elderly patients. Functional results were comparable to those in the literature, and the complications rate was lower. Long-term implant survival needs confirmation to validate this option as a treatment of choice in these indications in geriatric traumatology. TYPE OF STUDY: Retrospective non-comparative, single-center. LEVEL OF EVIDENCE: 4.


Assuntos
Artroplastia de Substituição do Cotovelo/métodos , Articulação do Cotovelo/cirurgia , Fraturas do Úmero/cirurgia , Osteoporose , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Fixação Interna de Fraturas/métodos , Serviços de Saúde para Idosos , Humanos , Masculino , Amplitude de Movimento Articular , Estudos Retrospectivos , Traumatologia , Resultado do Tratamento
3.
Orthop Traumatol Surg Res ; 101(2): 137-42, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25698098

RESUMO

BACKGROUND: Although they have been in use since the end of the 1980s, modular titanium neck components are associated with a risk of wear or fracture, and their safety has recently become a subject of debate and has never been evaluated in a consecutive series of patients. The goal of this study was to evaluate: revision-free survival of these implants after a minimum follow-up of 5 years; clinical and radiographic results; and the potential complications associated with the use of modular titanium neck components. HYPOTHESIS: The use of titanium modular neck on cemented titanium THA is safe at a minimum follow-up of 5 years. PATIENTS AND METHODS: Between January 2006 and December 2008, we prospectively followed 170 patients (170 hips) who underwent primary anatomical THA with a modular cemented titanium stem design implant. The indications were unilateral THA for primary (n=160) or secondary (n=10) hip osteoarthritis (aseptic osteonecrosis of the femoral head or hip dysplasia). Mean age of patients was 75.4±5.8 years old (52-85), and mean BMI was 26.1±4.5 kg/m(2) (16.6-42.1). Patients were operated on by a modified Watson-Jones anterolateral approach based on preoperative 2D planning. All patients underwent annual clinical and radiological follow-up by an independent observer. RESULTS: At a mean follow-up of 71±8 months (60-84), 5 patients died and 7 were lost to follow-up. There was no revision of THA after a maximum follow-up of 84 months. The Harris score improved significantly from 50.4±11.3 (0-76) preoperatively to 84.5±15.2 (14-100) at the final follow-up. There was no difference in postoperative femoral offset or the position of the center of rotation compared to the opposite side. On the other hand, the neck-shaft angle (NSA) and limb length were corrected (2±5° [-11 to +14°] and 2.16±3.6 mm [-7.4 to +12.7 mm]) respectively. Fifteen patients (9%) had limb length discrepancies of more than 5 mm and 4 patients (2%) of more than 10 mm. There were no complications due to the modular implant design. DISCUSSION: Our study suggests that the use of cemented titanium implants with a modular titanium stem is safe at a follow-up of 5 years. The modular design does not prevent limb length discrepancies but restores femoral offset. LEVEL OF EVIDENCE: IV: prospective, non-comparative study.


Assuntos
Artroplastia de Quadril/instrumentação , Cimentos Ósseos , Cabeça do Fêmur/cirurgia , Osteoartrite do Quadril/cirurgia , Titânio , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Prótese de Quadril , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Fatores de Tempo , Adulto Jovem
4.
Eur J Orthop Surg Traumatol ; 23(8): 933-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23412227

RESUMO

Twenty-two patients who received primary unicompartmental knee arthroplasties (21 medial and 1 lateral) were reoperated between 2001 and 2010 for partial or total replacement of their implant without using a TKA. Of the 21 patients (1 bilateral) reoperated for PE insert wear (11), PE fracture (3), infection (2), and loosening or malposition (6), 3 patients died and 2 were lost to follow up. The remaining 17 cases had their clinical scores significantly improved. Only one re-revision occurred and consisted of a simple change of PE insert at 9 years, on a very heavy and very active patient. It therefore seems possible and reasonable for now to continue partial or total replacement of unicompartmental knee arthroplasty by another unicompartmental knee arthroplasty without using a TKA.


Assuntos
Artroplastia do Joelho/métodos , Prótese do Joelho , Idoso , Feminino , Humanos , Articulação do Joelho/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Falha de Prótese , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/cirurgia , Radiografia , Reoperação/métodos , Estudos Retrospectivos , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/cirurgia , Infecções Estreptocócicas/etiologia , Infecções Estreptocócicas/cirurgia
5.
Encephale ; 39(3): 198-204, 2013 Jun.
Artigo em Francês | MEDLINE | ID: mdl-23095593

RESUMO

OBJECTIVE: The aim of this study is to focus on the clinical aspects of four linguistic indicators that emerge from automatic speech analysis. BACKGROUND: From a theoretical point of view, the number of proposals deals with cognitive activity, the number of modelizations with emotional activity, the number of connections with judgment activity and the number of action verbs can refer to behavioral activity. METHODS: To test these hypotheses we have studied two protocols of Thematic Aperception Test (TAT) randomized from non-clinical groups for the former and from a group of schizophrenic patients for the latter. RESULTS: The outcomes regarding the non-clinical protocols lead to the conclusion that the four indicators are coherent (α=0.93) and correlated; this confirms the clinical data on the cohesive personality of this young lady. The absence of correlations within the schizophrenic protocols reflects the dissociative syndrome of this patient. CONCLUSION: Finally, the study of the dynamics of this protocol, using our four linguistic criteria, confirms both the affective indifference and the increase of behavioral activity of this patient when the mentalization fails. After discussion and despite its capacity to describe clinical cases, the validity of this method needs to be completed (by relating the language indicators to production time stories) in further explorations, even if its reliability is good (α=0.93).


Assuntos
Emoções , Sistemas Inteligentes , Linguística , Processamento de Linguagem Natural , Software , Fala , Cognição , Feminino , Humanos , Julgamento , Valores de Referência , Esquizofrenia/diagnóstico , Linguagem do Esquizofrênico , Semântica , Senso de Coerência , Adulto Jovem
7.
Int J Cosmet Sci ; 30(5): 373-82, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18822044

RESUMO

A chromatographic method (high performance liquid chromatography) with a diode array detector was developed for simultaneous assay of Tinosorb S (bis-ethylhexyloxyphenol methoxyphenyl triazine) with three other sunscreen agents [benzophenone-3, butyl methoxydibenzoylmethane (avobenzone) and ethylhexyl methoxycinnamate] in high protection sunscreen. Separations were performed on a RP-18 Nucleodur Gravity column (150 x 4.6 mm, 5 mum) eluted with a ternary gradient mixture constituted of tetrahydrofuran, acetonitrile and an aqueous solution of acetic acid. The quantitative analysis was achieved with internal calibration performed with octyl dimethyl para-aminobenzoate (PABA) at 330 nm. In accordance with the analytical references (SFSTP, ICH, ISO...), the accuracy of the method was evaluated using a statistical approach of the validation parameters (specificity, response function, linearity, precision and trueness). For each studied ultraviolet filter, an accuracy profile was determined on a predicted range. These profiles show a graphical representation of the recovery percentage and confidence limits centred on 100%. The method is validated and can be used for analysis in cosmetic sunscreen products.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cosméticos/química , Fenóis/análise , Protetores Solares/análise , Triazinas/análise , Padrões de Referência , Reprodutibilidade dos Testes
8.
Rev Neurol (Paris) ; 164(5): 459-62, 2008 May.
Artigo em Francês | MEDLINE | ID: mdl-18555878

RESUMO

INTRODUCTION: Sensorial impairment without hemiplegia is usually caused by a thalamic lesion. CASE REPORT: A 28-year-old woman presented with hemianesthesia associated with aphasia following a left insular lesion, subsequent to subarachnoid hemorrhage. Brain MRI Flair sequence revealed a high intensity signal in the left insular and frontal subcortical regions. Insular infarct was diagnosed, associated with hemorrhagic sequelae. DISCUSSION/CONCLUSION: Study of the normal and pathologic insular cortex suggest several implications of the region in somatosensory and language functions. However, the insular cortex has been mainly associated with central pain. Lasting objective hypoesthesia has been very rarely documented. The left insular cortex has also been implicated in speech apraxia but our patient presented with fluent aphasia mostly affecting the rhythm of speech, as it has been observed in thalamic aphasia.


Assuntos
Afasia/etiologia , Afasia/psicologia , Infarto Cerebral/complicações , Infarto Cerebral/psicologia , Transtornos de Sensação/etiologia , Transtornos de Sensação/psicologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/psicologia , Adulto , Afasia/patologia , Infarto Cerebral/patologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Imageamento por Ressonância Magnética , Paresia/etiologia , Transtornos de Sensação/patologia , Acidente Vascular Cerebral/patologia , Hemorragia Subaracnóidea/complicações , Tálamo/patologia , Tomografia Computadorizada por Raios X
9.
Anal Bioanal Chem ; 390(7): 1861-71, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18278588

RESUMO

Bacterial surface-associated proteins play crucial roles in host-pathogen interactions and pathogenesis. The identification of these proteins represents an important goal of bacterial proteomics for vaccine development, but also for environmental concerns such as microbial biosensing. Here, we developed such an approach for Legionella pneumophila, a bacterium that causes severe pneumonia. We propose a complementary strategy consisting of (1) a fluorescent labelling of surface-exposed proteins in parallel with (2) a fractionation of the outer-membrane protein extract. These two distinct protein populations were subsequently separated using two-dimensional gel electrophoresis and characterised by mass spectrometry. Within these populations, we found proteins which were expected for the compartments studied, but also a great number of proteins never experimentally described, and also a non-negligible fraction of proteins never described in these fractions. These data provided new routes of inspection for transport and host recognition for Legionella pneumophila. In addition, these results on the membranome and surfaceome show that Legionella in the stationary phase of growth possesses the major determinants to infect host cells.


Assuntos
Proteínas da Membrana Bacteriana Externa/química , Corantes Fluorescentes/química , Legionella pneumophila/química , Mapeamento de Peptídeos/métodos , Proteômica/métodos , Fracionamento Celular , Eletroforese em Gel Bidimensional/métodos , Legionella pneumophila/crescimento & desenvolvimento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Coloração e Rotulagem , Propriedades de Superfície
10.
Br J Clin Pharmacol ; 46(5): 489-97, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9833603

RESUMO

AIMS: Administration of L-arginine by intravenous infusion or via oral absorption has been shown to induce peripheral vasodilation in humans, and to improve endothelium-dependent vasodilation. We investigated the pharmacokinetics and pharmacokinetic-pharmacodynamic relationship of L-arginine after a single intravenous infusion of 30 g or 6 g, or after a single oral application of 6 g, as compared with the respective placebo, in eight healthy male human subjects. METHODS: L-arginine levels were determined by h.p.l.c. The vasodilator effects of L-arginine were assessed non-invasively by blood pressure monitoring and impedance cardiography. Urinary nitrate and cyclic GMP excretion rates were measured as non-invasive indicators of endogenous NO production. RESULTS: Plasma L-arginine levels increased to (mean +/- s.e.mean) 6223+/-407 (range, 5100-7680) and 822+/-59 (527-955) micromol l(-1) after intravenous infusion of 30 g and 6 g L-arginine, respectively, and to 310+/-152 (118-1219) micromol l(-1) after oral ingestion of 6 g L-arginine. Oral bioavailability of L-arginine was 68+/-9 (51-87)%. Clearance was 544+/-24 (440-620), 894+/-164 (470-1190), and 1018+/-230 (710-2130) ml min(-1), and elimination half-life was calculated as 41.6+/-2.3 (34-55), 59.6+/-9.1 (24-98), and 79.5+/-9.3 (50-121) min, respectively, for 30 g i.v., 6 g i.v., and 6 g p.o. of L-arginine. Blood pressure and total peripheral resistance were significantly decreased after intravenous infusion of 30 g L-arginine by 4.4+/-1.4% and 10.4+/-3.6%, respectively, but were not significantly changed after oral or intravenous administration of 6 g L-arginine. L-arginine (30 g) also significantly increased urinary nitrate and cyclic GMP excretion rates by 97+/-28 and 66+/-20%, respectively. After infusion of 6 g L-arginine, urinary nitrate excretion also significantly increased, (nitrate by 47+/-12% [P<0.05], cyclic GMP by 67+/-47% [P= ns]), although to a lesser and more variable extent than after 30 g of L-arginine. The onset and the duration of the vasodilator effect of L-arginine and its effects on endogenous NO production closely corresponded to the plasma concentration half-life of L-arginine, as indicated by an equilibration half-life of 6+/-2 (3.7-8.4) min between plasma concentration and effect in pharmacokinetic-pharmacodynamic analysis, and the lack of hysteresis in the plasma concentration-versus-effect plot. CONCLUSIONS: The vascular effects of L-arginine are closely correlated with its plasma concentrations. These data may provide a basis for the utilization of L-arginine in cardiovascular diseases.


Assuntos
Arginina/farmacologia , Arginina/farmacocinética , Vasodilatação/efeitos dos fármacos , Administração Oral , Adulto , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , GMP Cíclico/metabolismo , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Humanos , Injeções Intravenosas , Masculino , Nitratos/urina , Óxido Nítrico/metabolismo
11.
Int J Card Imaging ; 14(3): 179-86; discussion 187-9, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9813755

RESUMO

Coronary blood flow quantification provides essential information on the hemodynamic significance of coronary artery stenoses. Recently, magnetic resonance (MR) flow mapping has emerged as a new promising method to noninvasively determine flow velocity and flow volume within the coronary arteries. The aim of this study was to compare phase difference (PD) MR flow quantification with intracoronary Doppler flow measurements in 15 patients with suspected or known coronary artery disease. Flow quantification was attempted before and after systemic application of 5mg Isosorbiddinitrate (ISDN) in order to determine possible alterations in coronary flow volume. PD MR flow mapping was performed successfully in 13 of the 15 patients. For flow velocities and flow volume values, a close correlation between PD MR and Doppler flow measurements was found (r = 0.79 and r = 0.90, respectively). However, average flow measured by PD MR was significantly lower than the invasively obtained values (9.0 +/- 4.4 cm/sec vs. 11.7 +/- 4.9 cm/sec; p < 0.001 and 46.3 +/- 28.7 ml/min vs. 53.4 +/- 32.8 ml/min; p < 0.05). Although the mean flow volume remained constant in the entire patient group after ISDN application, individual changes (increase in 6, decrease in 4 cases) could be documented with PD MR imaging and showed a good correlation to the Doppler method (r = 0.82). In conclusion, PD MR flow mapping is a promising method for the noninvasive quantification of coronary blood flow and therefore offers the potential of assessing coronary artery stenoses. However, technical improvements are mandatory in order to increase accuracy of the method.


Assuntos
Circulação Coronária/fisiologia , Doença das Coronárias/diagnóstico , Imageamento por Ressonância Magnética/métodos , Ultrassonografia Doppler , Velocidade do Fluxo Sanguíneo/fisiologia , Circulação Coronária/efeitos dos fármacos , Doença das Coronárias/fisiopatologia , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Dinitrato de Isossorbida , Masculino , Pessoa de Meia-Idade , Ultrassonografia de Intervenção , Vasodilatadores
12.
J Chromatogr B Biomed Sci Appl ; 706(1): 63-71, 1998 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-9544808

RESUMO

Cod fish is one of the foods most frequently involved in allergy. Only the cod allergen Gad c I, a 12.3 kDa parvalbumin, has been purified and characterized. Recently, we have detected allergen bands which have not previously been described, in particular a 41 kDa protein, by Western-blot. In the present work, this protein has been purified from a crude cod extract by ammonium sulfate fractionation, hydroxyapatite chromatography and preparative electrophoresis; a single band with an Mr of 41 x 10(3) was found in silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amino acid composition and the isoelectric point of the protein were determined. The purified protein (p41) was shown to bind specifically to reaginic IgE from sera of cod-allergic individuals and to a monoclonal anti-parvalbumin which recognizes specifically the first calcium binding site of parvalbumins. p41 may therefore contain a calcium binding site corresponding to an IgE-epitope similar to that of Gad c I.


Assuntos
Alérgenos/isolamento & purificação , Peixes , Proteínas/isolamento & purificação , Aminoácidos/análise , Sulfato de Amônio , Animais , Cromatografia , Durapatita , Eletroforese , Eletroforese em Gel de Poliacrilamida , Hipersensibilidade Alimentar , Precipitação Fracionada , Concentração de Íons de Hidrogênio , Peso Molecular , Proteínas/química , Proteínas/imunologia , Coloração pela Prata
13.
Naunyn Schmiedebergs Arch Pharmacol ; 357(2): 143-50, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9521487

RESUMO

We compared the effects of L-arginine (L-ARG), the precursor of endogenous NO, on platelet aggregation and thromboxane A2 formation in vivo and in vitro. Human platelet-rich plasma (PRP) was anticoagulated with citrate (which decreases extracellular Ca2+) or with recombinant hirudin (which does not affect extracellular Ca2+). Two groups of 10 healthy male volunteers received intravenous infusions of L-ARG (30 g or 6 g, 30 min) or placebo. Blood was collected immediately before and at the end of the infusions for aggregation by ADP or collagen. Infusion of L-ARG inhibited ADP-induced aggregation in PRP anticoagulated with citrate by 37.5+/-6.3% (P < 0.05). In PRP anticoagulated with hirudin, aggregation was inhibited by 33.6+/-16.0% (P < 0.05). L-ARG infusion also inhibited platelet TXB2 formation and slightly, but not significantly decreased the urinary excretion rate of 2,3-dinor-TXB2; cGMP concentrations in PRP were significantly elevated during L-arginine infusion. In vitro preincubation with L-ARG (10 microM-2.5 mM) inhibited platelet aggregation in PRP anticoagulated with rhirudin, but not citrate. This effect was stereospecific for L-arginine, as D-arginine had no effect. It was dependent upon NO synthase activity, as indicated by increased cGMP levels in PRP. Moreover, both the NOS inhibitor L-NMMA and the inhibitor of soluble guanylyl cyclase ODQ antagonized the effects of L-ARG. Haemoglobin, an extracellular scavenger of NO, partly antagonized the antiplatelet effects of L-ARG. 8-Br-cyclic GMP and the exogenous NO donor linsidomine inhibited aggregation in PRP anticoagulated with citrate or r-hirudin. The inhibitory effects of L-ARG on platelet aggregation in vitro were paralleled by increased cyclic GMP levels; L-ARG also inhibited platelet TXB2 formation in PRP anticoagulated with r-hirudin, but not citrate. We conclude that the L-arginine/NO pathway is present in human platelets as a Ca2+-dependent anti-aggregatory pathway. In vivo the formation of NO from L-ARG by endothelial cells may contribute to the platelet-inhibitory effects of L-ARG. NO-releasing compounds like linsidomine inhibit platelet aggregation in vitro independent of extracellular Ca2+.


Assuntos
Arginina/farmacologia , Plaquetas/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Tromboxano A2/biossíntese , Tromboxanos/análogos & derivados , Adulto , Antitrombinas/farmacologia , Arginina/administração & dosagem , Plaquetas/efeitos dos fármacos , GMP Cíclico/análogos & derivados , GMP Cíclico/farmacologia , Inibidores Enzimáticos/farmacologia , Humanos , Técnicas In Vitro , Infusões Intravenosas , Masculino , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Inibidores da Agregação Plaquetária/farmacologia , Tromboxano B2/análogos & derivados , Tromboxano B2/urina
14.
Clin Sci (Lond) ; 93(2): 159-65, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9301431

RESUMO

1. Endothelium-derived nitric oxide (NO) contributes to the regulation of vascular tone and blood pressure. Infusion of L-arginine produces systemic vasodilatation via stimulation of endogenous NO formation. Vasodilatation is accompanied by an increase in peripheral arterial blood flow. However, it is not known whether capillary nutritive blood flow increases as well. The time course and dose-response pattern of this effect remain to be elucidated. 2. Two groups of ten patients with peripheral vascular disease (PVD) received an intravenous infusion of 8 g or 30 g of L-arginine over a period of 40 min. Blood pressure and heart rate were monitored non-invasively. Muscular blood flow (MBF) of the calf was determined at 0, 20, 40, 60, 80 min by positron emission tomography with H215O as flow tracer. Plasma L-arginine and cyclic GMP (cGMP) levels were determined at the same time points. 3. L-arginine induced a dose-related decrease in blood pressure during the infusion period. MBF and plasma cGMP levels during and after the infusion of 8 g of L-arginine did not change significantly. In the patients receiving 30 g of L-arginine, MBF was enhanced significantly from 1.56 +/- 0.14 to 2.09 +/- 0.21 ml min-1 100 ml-1 at 40 min and 2.23 +/- 0.15 ml min-1 100 ml-1 after 80 min (+43.0%). The increase in MBF was paralleled by an increase in plasma cGMP from 4789.8 +/- 392.2 nmol/l at baseline to 9223.2 +/- 1233.6 nmol/l at 40 min. 4. We conclude that intravenous L-arginine enhances nutritive capillary MBF in patients with PVD via the NO-cGMP pathway in a dose-related manner. This effect might be therapeutically beneficial in patients with PVD.


Assuntos
Arginina/farmacologia , Perna (Membro)/irrigação sanguínea , Músculo Esquelético/irrigação sanguínea , Doenças Vasculares Periféricas/fisiopatologia , Idoso , Arginina/sangue , Pressão Sanguínea/efeitos dos fármacos , GMP Cíclico/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Infusões Intravenosas , Perna (Membro)/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Fluxo Sanguíneo Regional/efeitos dos fármacos , Tomografia Computadorizada de Emissão/métodos
15.
Ann Biol Clin (Paris) ; 54(8-9): 309-20, 1996.
Artigo em Francês | MEDLINE | ID: mdl-9092310

RESUMO

The impact of the major interferents (hemolysis, bilirubin, turbidity), on the quality of biochemical tests, was evaluated on multiparametric analysers (CL 7200 Shimadzu, Japan/Ciba-Corning, France; AU 5231 and AU 5223 Olympus, Japan/bioMérieux, France), according to the SFBC instructions. Interferences were detected in 33 cases upon 165 tests realized, that is to say 20% of the performed analysis. Turbidity was the most frequent cause of interference (7.8%), followed by hemolysis (8.5%) and bilirubin (3.6%). The use of a sample blank, a bireagent, the change of reagent, the change of the secondary wavelength or the modification of the measurement times, allowed us to reduce more than 80% of the interferences. Only three interferences remained: hemolysis upon the measurement of TGO and potassium, and bilirubin upon the measurement of creatinine. For these parameters, a suitable note using the Olympus factors (semi quantitative expression of the importance of the three interferents) is reported on the answer sheet.


Assuntos
Análise Química do Sangue/métodos , Animais , Bilirrubina/farmacologia , Interações Medicamentosas , Hemólise , Nefelometria e Turbidimetria
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