Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Internist (Berl) ; 57(12): 1235-1242, 2016 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-27501812

RESUMO

This article presents the case of a combined intervention for transcatheter aortic valve implantation (TAVI) and stenting of the internal carotid artery. Due to severe aortic stenosis and a subacute infarction in the middle cerebral artery territory, with neurological instability while hypotensive and cardiac failure while hypertensive, it was decided to carry out the intervention as a single combined procedure. An open surgical intervention was decided against because of the high peri-interventional mortality risk. The intervention was complication-free but a slight subarachnoid hemorrhage occurred in the postinterventional period. It was unclear if the bleeding was the result of cerebral hyperperfusion poststenting, if bleeding in an ischemic region was favored by post-TAVI hyperemia and whether the outcome would have been better with two separate interventions.


Assuntos
Estenose da Valva Aórtica/cirurgia , Prótese Vascular , Estenose das Carótidas/cirurgia , Stents , Substituição da Valva Aórtica Transcateter/métodos , Idoso , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Terapia Combinada/instrumentação , Terapia Combinada/métodos , Feminino , Humanos , Resultado do Tratamento
3.
Ann Hematol ; 93(7): 1159-65, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24488226

RESUMO

Determination of red cell volume (RCV) might contribute to establishing the diagnosis of polycythemia vera (PV). A novel simplified method to detect RCV through CO rebreathing is nowadays applied in healthy young individuals but was not tested in a clinical or PV setting. The aim of the present study is to evaluate whether this spirometric approach is applicable in older subjects and contributes to PV diagnosis in a proof-of-concept approach. At first, RCV was determined by the optimized CO-rebreathing method in healthy subjects >50 years of age (n = 81, age 66 ± 9 years). Failure rate and age distribution of subjects who failed with CO rebreathing were analyzed. Then, RCV was measured in male PV patients (n = 7) and compared to healthy male controls (n = 35). RCV values in relation to several anthropometric references (body weight, body surface area (BSA), lean body mass (LBM)) were calculated to determine the sensitivity and specificity of established RCV thresholds when using optimized CO rebreathing. In healthy subjects, test failure rate was 9.9 %, but failure was not associated with age. Sensitivity and specificity (sens/spec) to detect PV was 100 %/83 % using the criteria of the PV study group. Using criteria based on BSA, sens/spec was 14 %/100 %. An arbitrary threshold of 50 ml/kg LBM yielded sens/spec of 100 %/97 %. In conclusion, this proof-of-concept indicates that optimized CO rebreathing is applicable in older subjects and allows determining RCV for the diagnosis of PV. Normalized values for RCV measures obtained from CO rebreathing are needed to grant sufficient sensitivity and/or specificity.


Assuntos
Monóxido de Carbono/metabolismo , Volume de Eritrócitos/fisiologia , Hemoglobinas/metabolismo , Inalação/fisiologia , Policitemia Vera/diagnóstico , Policitemia Vera/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Policitemia Vera/fisiopatologia , Estudos Retrospectivos , Espirometria/métodos , Espirometria/normas
4.
Int J Lab Hematol ; 34(6): 641-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22805050

RESUMO

INTRODUCTION: Dehydration, fluid shifts or changes in coagulation occurring during air travel can trigger distinct reactions in the haematological system. Athletes are concerned that these effects might impair sporting performance, increase the risk of thrombosis or cause abnormalities in blood values that might be mistaken for doping in the 'Athlete's biological passport' (ABP) a longitudinal monitoring of haematological variables in antidoping. The aim of the study was to investigate key variables of the ABP before and after a long-haul flight in athletes. METHODS: Fifteen endurance athletes were submitted to ABP blood samples in the morning before and after arrival of an 8 h flight. Two additional samples were obtained in the morning and the evening 3 days after the travel. Twelve nontravelling subjects served as controls. RESULTS: Haemoglobin concentration was higher before than after travel in athletes (+0.5 g/dL, P = 0.038), a similar pattern was observed 3 days after the travel. No difference was observed in the control group. Reticulocyte% did not show any significant changes in neither of the groups. CONCLUSION: The observed changes are in line with normal diurnal variations. There is no indication that travel will affect haematological variables in way that might be mistaken for blood doping.


Assuntos
Viagem Aérea , Atletas , Biomarcadores/sangue , Medicina Esportiva/métodos , Adulto , Ritmo Circadiano , Testes Hematológicos/métodos , Hemoglobinas/análise , Humanos , Contagem de Reticulócitos , Fatores de Tempo , Adulto Jovem
5.
Int J Lab Hematol ; 33(2): 146-53, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20718874

RESUMO

INTRODUCTION: With the setting up of the newly Athlete's Biological Passport antidoping programme, novel guidelines have been introduced to guarantee results beyond reproach. We investigated in this context, the effect of storage time on the variables commonly measured for the haematological passport. We also wanted to assess for these variables, the within and between analyzer variations. METHODS: Blood samples were obtained from top level male professional cyclists (27 samples for the first part of the study and 102 for the second part) taking part to major stage races. After collection, they were transported under refrigerated conditions (2 °C < T < 12 °C), delivered to the antidoping laboratory, analysed and then stored at approximately 4 °C to conduct analysis at different time points up to 72 h after delivery. A mixed-model procedure was used to determine the stability of the different variables. RESULTS: As expected haemoglobin concentration was not affected by storage and showed stability for at least 72 h. Under the conditions of our investigation, the reticulocytes percentage showed a much better stability than previous published data (> 48 h) and the technical comparison of the haematology analyzer demonstrated excellent results. CONCLUSION: In conclusion, our data clearly demonstrate that as long as the World Anti-Doping Agency's guidelines are followed rigorously, all blood results reach the quality level required in the antidoping context.


Assuntos
Dopagem Esportivo , Testes Hematológicos/métodos , Atletas , Testes Hematológicos/instrumentação , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes
6.
Int J Sports Med ; 32(2): 147-50, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21110289

RESUMO

The haematological module of the "Athletes Biological Passport" (ABP) is used to detect blood doping through the longitudinal variation of blood variables, such as haemoglobin concentration (Hb). Sporting federations have opened disciplinary procedures against athletes based on ABP results. Suspicious athletes try to explain the variations in their blood values with dehydration caused by gastrointestinal (GI) problems. The aim of the present report is to describe haemoglobin concentration, a key variable of the ABP, during acute gastroenteritis in athletes. 5 athletes with severe gastroenteritis were studied in retrospective. Blood test results (Hb, white blood cell count (WBC) and differential, CRP) obtained on hospital admission for GI problems were compared to data obtained from the same athletes in states of good health on previous occasions. During GI problems, athletes displayed marked inflammatory constellations with increased CRP and typical WBC shifts. Hb was not affected and remained mostly unchanged. This is in line with basic physiologic fluid regulation, where plasma volume is kept constant, even under conditions of severe dehydration. It is therefore unlikely that fluid loss associated with gastroenteritis will cause athletes blood data to reach levels of abnormality that will be suspicious of blood doping.


Assuntos
Atletas , Dopagem Esportivo , Gastroenterite/sangue , Testes Hematológicos , Doença Aguda , Adulto , Ciclismo/fisiologia , Biomarcadores/sangue , Proteína C-Reativa/análise , Desidratação/sangue , Hematócrito , Hemoglobinometria , Humanos , Contagem de Leucócitos , Estudos Longitudinais , Masculino , Volume Plasmático , Estudos Retrospectivos , Futebol/fisiologia , Adulto Jovem
8.
Int J Sports Med ; 31(4): 225-30, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20148373

RESUMO

Haemoglobin (Hb) and Reticulocytes (Ret) are measured as indirect markers of doping in athletes. We studied the diurnal variation, the impact of exercise, fluid intake and ambient temperature in athletes on these parameters. Hourly venous blood samples were obtained from 36 male athletes of different disciplines (endurance (END) and non-endurance (NON-END)) over 12 h during a typical training day. Seven inactive subjects served as controls (CON). Hb and Ret were determined. A mixed model procedure was used to analyse the data. At baseline, Hb was similar for all groups, END showed lower Ret than NON-END and CON. Exercise showed a significant impact on Hb (+0.46 g/dl, p<0.001), the effect disappeared approximately 2 h after exercise. Hb decreased over the day by approximately 0.55 g/dl (p<0.01). There was no relevant effect on Ret. Fluid intake and ambient temperature had no significant effect. Hb shows significant diurnal- and exercise related variations. In an anti-doping context, most of these variations are in favour of the athlete. Blood samples taken after exercise might therefore provide reliable results and thus be used for the longitudinal monitoring of athletes if a timeframe for the re-equilibration of vascular volumes is respected.


Assuntos
Ritmo Circadiano/fisiologia , Exercício Físico/fisiologia , Hemoglobinas/análise , Reticulócitos , Esportes/fisiologia , Adulto , Algoritmos , Regulação da Temperatura Corporal , Estudos de Casos e Controles , Dopagem Esportivo , Ingestão de Líquidos , Humanos , Masculino , Atividade Motora/fisiologia , Resistência Física/fisiologia , Contagem de Reticulócitos , Reticulócitos/citologia , Temperatura , Fatores de Tempo
9.
Int J Lab Hematol ; 32(5): 506-11, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20148988

RESUMO

Haemoglobin (Hb) and haematocrit (Hct) are measured as indirect markers of doping in athletes. We studied the effect of posture on these parameters in a typical antidoping setting. Venous blood samples were obtained from nine endurance athletes (six males, three females) and nine control subjects (six males, three females) immediately and after 5, 10, 15, 20 and 30 min after having adopted a seated position from normal daily activity. Hb (CV 0.72%) and Hct (CV 0.87%) were determined using an automated cell counter, plasma volume changes were calculated. Differences between the time points, gender and groups were calculated using a mixed-model procedure. Significant changes were observed in the first 10 min after sitting down but no further changes were noted between 10 and 30 min. Mean directional change for Hb and Hct between 0 min and the average of the period from 10 to 30 min was -2.4% (-0.35 g/dl) for Hb and -2.7% (-1.2%) for Hct. Plasma volume increased accordingly. Neither group nor gender had significant effects. Under typical conditions encountered during blood testing in doping control, a period of 10 min in a seated position is sufficient for the vascular volumes to re-equilibrate and to adapt to the new posture.


Assuntos
Atletas , Coleta de Amostras Sanguíneas/normas , Dopagem Esportivo , Hematócrito , Hemoglobinas/análise , Postura , Adulto , Feminino , Humanos , Masculino , Volume Plasmático
11.
Vox Sang ; 96(2): 119-27, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19152604

RESUMO

BACKGROUND AND OBJECTIVES: Total haemoglobin mass (tHb) as a direct parameter of the blood system and ultimate target of all blood transfusions has not been evaluated for its post-transfusion survival and stability. Therefore, the purpose of this study was to investigate the latter which may also be relevant from an anti-doping perspective as autologous blood transfusions remain impossible to detect. MATERIALS AND METHODS: The tHb was determined by the CO rebreathing method prior to and after donation of 1 unit of whole blood, as well as prior to and after reinfusion (weekly up to 56 days) of the erythrocyte concentrate in 10 men (28 +/- 7 years, 181 +/- 7 cm, 76 +/- 12 kg). RESULTS: The mean tHb content of the derived erythrocyte concentrate was 60 +/- 3 g, while the net tHb increases after transfusion of 51 g (95% confidence intervals 33-69 g) permitted proof of an elevated tHb for at least 56 days after transfusion. CONCLUSION: The results show that an elevated tHb induced by autologous transfusion allowed continuous identification although, as expected, a slow decrease of tHb has been revealed in the observation period. In reference to anti-doping, CO rebreathing permits proof of a supraphysiologically elevated tHb but possibly only if a stable baseline value is known.


Assuntos
Transfusão de Sangue Autóloga , Hemoglobinas/análise , Adulto , Monóxido de Carbono , Dopagem Esportivo , Humanos , Masculino , Detecção do Abuso de Substâncias/métodos , Adulto Jovem
12.
J Sports Med Phys Fitness ; 49(4): 364-71, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20087295

RESUMO

AIM: Chronic endurance exercise triggers increased cardiac dimensions, blood volumes and haemoglobin mass (Hb mass). Cardiac output and Hb mass are considered as independent contributors to aerobic performance. Therefore, increased Hb mass could counterbalance for a relative deficiency in cardiac adaptation. The purpose of the present study is to investigate relations between Hb mass and cardiac dimensions in a group of endurance athletes with respect to aerobic capacity. METHODS: Two groups of highly trained cyclists featuring high (HHB group, N.=13) and low (LHB group, N.=13) Hb mass (measured by a CO-rebreathing method) were compared for measures of aerobic performance, cardiac wall thickness, cavity size and left ventricular mass (determined by 2-D-echocardiography). Lean body mass (LBM) was chosen as anthropometrical reference for Hb mass. RESULTS: HHB featured higher cardiac wall thickness than LHB, but no difference appeared in cardiac cavity size, left ventricular mass and the performance parameters. Normalising Hb mass for body weight instead of LBM improved correlations between Hb mass and performance parameters. CONCLUSIONS: Our data provides new evidence for a connection between cardiac wall thickness and Hb mass in endurance athletes but no further evidence for a counterbalance between Hb mass and cardiac adaptation was found. Moreover, we postulate that Hb mass loses predictive value for aerobic performance when normalised for LBM.


Assuntos
Ciclismo/fisiologia , Volume de Eritrócitos/fisiologia , Tolerância ao Exercício/fisiologia , Exercício Físico/fisiologia , Coração/anatomia & histologia , Hemoglobinas/análise , Adaptação Fisiológica , Adulto , Volume Sanguíneo/fisiologia , Débito Cardíaco , Teste de Esforço , Feminino , Coração/fisiologia , Humanos , Masculino , Consumo de Oxigênio , Estatística como Assunto
13.
J Sports Med Phys Fitness ; 48(4): 509-14, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18997656

RESUMO

AIM: Blood volume and hemoglobin mass (tHb) are new emerging parameters in exercise physiology. The appropriate anthropometrical reference for these variables has not yet been investigated. In most current investigations, body weight is used in this context. The aim of the present study was therefore to evaluate three different anthropometrical parameters (body weight, body surface area [BSA] and lean body mass [LBM] with respect to tHb. METHODS: Sixty-five healthy male endurance athletes underwent a tHb determination (optimised CO rebreathing method) and anthropometrical evaluation (skinfold measurement) with estimation of body weight, LBM and BSA. Correlation analysis was performed; the correlations of the different anthropometrical reference ratios were compared and evaluated with regards to body composition. RESULTS: LBM showed the best correlation with tHb (R=0.81), although no significant differences between the three anthropometrical references were found (BSA R=0.76, body weight R=0.77). In contrast to tHb/body weight, tHb/LBM was independent of body fat content and thus body composition. CONCLUSION: The current study demonstrated no statistical difference between various anthropometrical references for tHb, which might be due to the anthropometrically homogenous study group of lean, endurance trained athletes. However, the significance dependence of body weight on body fat content indicates that this might not be the case in athletes of other somatotypes. It is therefore suggested that LBM instead of body weight should be used as anthropometrical reference when investigating tHb in athletes.


Assuntos
Antropometria/métodos , Pesos e Medidas Corporais/normas , Hemoglobinas/normas , Resistência Física/fisiologia , Esportes/fisiologia , Limiar Anaeróbio/fisiologia , Volume Sanguíneo/fisiologia , Humanos , Masculino , Padrões de Referência , Adulto Jovem
14.
Int J Sports Med ; 29(3): 244-50, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17990203

RESUMO

The aim of the study was to report the relationship between cadence and power developed by professional cyclists during high mountain ascents of the Tour de France. From the 10 cyclists (30 +/- 4 years, 178 +/- 8 cm, 69 +/- 6 kg) involved in the study, 108 ascents were recorded and analyzed using a mobile power measurement device (SRM Training Systems, Jülich, Germany). Based on topographic characteristics, the ascents were categorized into 1st and Hors Category (HC) climbs. During the ascents of the 1st Category climbs, power output averaged 312 +/- 43 W (4.5 +/- 0.6 W/kg) with a mean cadence of 73 +/- 6 rpm and a mean duration of 37 : 41 +/- 16 : 16 min. Power output averaged 294 +/- 36 W (4.3 +/- 0.6 W/kg) at a mean cadence of 70 +/- 6 rpm during 57 : 40 +/- 10 : 32 min on HC climbs. The maximal mean power for long durations (1800 s) showed a mean power output of 327 W and 346 W for the 1st and HC climbs, respectively. The evaluation of the cadence-power output and the distance per pedaling cycle-power output relationship shows that high power outputs are mainly yielded by higher pedaling cadences and higher gears.


Assuntos
Ciclismo/fisiologia , Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Adulto , Desempenho Atlético/fisiologia , Humanos
15.
Int J Sports Med ; 29(5): 372-8, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17614021

RESUMO

Haemoglobin mass is a main determinant of maximal oxygen uptake. Blood doping aims at increasing this variable. Limits for haematocrit and haemoglobin concentration are used as indicators of blood doping. However, these variables are measures of concentration, do not represent total haemoglobin mass and are altered by vascular volumes shifts. Direct estimation of haemoglobin mass could improve blood tests. It is unknown if physical exercise alters haemoglobin mass. The purpose of this study was to investigate the reaction of haemoglobin mass and other vascular compartments to heavy exercise in athletes. Haemoglobin mass and vascular compartments were evaluated using the optimised CO rebreathing method in 7 elite cyclists during a stage race. Simultaneously, haemoglobin concentration and haematocrit were analysed. Haemoglobin mass (pre-race 958 +/- 123 g, end race 948 +/- 106 g) and red cell volume did not change significantly over the study period, while plasma volume and blood volume tended to increase. Haematocrit (pre-race 44.1 +/- 2.5 %, end race 40.9 +/- 1.59 %) and haemoglobin concentration (pre race 15.8 +/- 0.9 g/dl, end race 14.7 +/- 0.7 g/dl) decreased. During the study, a plasma volume expansion as adaptation to prolonged exercise occurred. Haemoglobin concentration and haematocrit decreased accordingly, whereas haemoglobin mass remained stable. Haemoglobin mass might therefore be a suitable screening tool for blood manipulations.


Assuntos
Ciclismo/fisiologia , Hemoglobinas/análise , Adulto , Dopagem Esportivo , Alemanha , Hematócrito , Humanos , Masculino , Consumo de Oxigênio/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...