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1.
Am J Physiol Regul Integr Comp Physiol ; 278(6): R1583-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10848527

RESUMO

Previous results indicate that arterial pulse pressure modulates release of arginine vasopressin (AVP) in humans. The hypothesis was therefore tested that an increase in arterial pulse pressure is the stimulus for suppression of AVP release during central blood volume expansion by water immersion. A two-step immersion model (n = 8) to the xiphoid process and neck, respectively, was used to attain two different levels of augmented cardiac distension. Left atrial diameter (echocardiography) increased from 28 +/- 1 to 34 +/- 1 mm (P < 0.05) during immersion to the xiphoid process and more so (P < 0.05), to 36 +/- 1 mm, during immersion to the neck. During immersion to the xiphoid process, arterial pulse pressure (invasively measured in a brachial artery) increased (P < 0.05) from 44 +/- 1 to 51 +/- 2 mmHg and to the same extent from 42 +/- 1 to 52 +/- 2 mmHg during immersion to the neck. Mean arterial pressure was unchanged during immersion to the xiphoid process and increased during immersion to the neck by 7 +/- 1 mmHg (P < 0.05). Arterial plasma AVP decreased from 2.5 +/- 0.7 to 1.8 +/- 0.5 pg/ml (P < 0. 05) during immersion to the xiphoid process and significantly more so (P < 0.05), to 1.4 +/- 0.5 pg/ml, during immersion to the neck. In conclusion, other factors besides the increase in arterial pulse pressure must have participated in the graded suppression of AVP release, comparing immersion to the xiphoid process with immersion to the neck. We suggest that when arterial pulse pressure is increased, graded distension of cardiopulmonary receptors modulate AVP release.


Assuntos
Pressão Sanguínea/fisiologia , Regulação da Temperatura Corporal/fisiologia , Sistema Nervoso Simpático/fisiologia , Vasopressinas/sangue , Adulto , Débito Cardíaco/fisiologia , Humanos , Masculino , Pescoço , Pressorreceptores/fisiologia , Água , Processo Xifoide
2.
J Appl Physiol (1985) ; 81(1): 408-12, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8828692

RESUMO

Based on the results of head-down simulation studies and the results of parabolic flights, the hypothesis was tested that central venous pressure (CVP) in humans increases during microgravity (weightlessness) compared with during the ground-based supine position. CVP was recorded with an intravascular pressure transducer in seven healthy humans during short (20-s) periods of microgravity created by parabolic-flight maneuvers and in one astronaut before, during, and up to 3 h after launch of the Spacelab D-2 mission (Space Transport System-55). When the subjects were supine during the parabolic maneuver, CVP decreased during microgravity from 6.5 +/- 1.3 to 5.0 +/- 1.4 mmHg (P < 0.05). during the Spacelab D-2 mission, CVP was 6.2 mmHg during the initial minutes of microgravity, which was very similar to the value of 6.5 mmHg in the supine position 3.5 h before launch of the space shuttle. During the subsequent 3 h of weightlessness, CVP during rest varied between 2.0 and 6.2 mmHg. We conclude that CVP during short (20-s) and longer (3-h) periods of microgravity is close to or below that of the supine position on the ground.


Assuntos
Pressão Venosa Central/fisiologia , Ausência de Peso/efeitos adversos , Adulto , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Voo Espacial , Decúbito Dorsal/fisiologia , Simulação de Ausência de Peso
3.
J Appl Physiol (1985) ; 78(6): 2253-9, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7665426

RESUMO

It was the purpose of this study to investigate how the endocrine and renal mechanisms of fluid volume control in humans (n = 4) adapt to microgravity by applying an intravenous isotonic saline infusion. The acute ground-based supine (Sup) and seated (Seat) positions were chosen as references. During microgravity, renal sodium excretion (UNaV) was doubled during the second and third hours after infusion compared with during Seat (P < 0.05) but blunted during the first hour after infusion compared with during Sup, leading to a reduction in cumulative UNaV (59 +/- 15 vs. 108 +/- 12 mmol/5 h; P < 0.05). Plasma norepinephrine (NE) attained the highest value 3 h after infusion during microgravity (31 +/- 5 x 10(-2) ng/ml vs. 19 +/- 1 and 13 +/- 3 x 10(-2) ng/ml for Seat and Sup, respectively; P < 0.05). Inflight levels of plasma renin and aldosterone were very similar to levels during Seat. In conclusion, 1) the microgravity-adapted renal responses to infusion reflected a condition in between that of ground-based Seat and Sup, respectively, and 2) the plasma levels of NE, renin, and aldosterone were elevated inflight and not related to the changes in UNaV and urinary flow rate. These observations are in contrast to results of ground-based simulation experiments and might partly have been caused by a prior inflight reduction in extracellular fluid volume. The high levels of NE during microgravity warrant further investigation.


Assuntos
Soluções Isotônicas/administração & dosagem , Rim/fisiologia , Cloreto de Sódio/administração & dosagem , Equilíbrio Hidroeletrolítico/fisiologia , Ausência de Peso , Adulto , Diurese/fisiologia , Humanos , Infusões Intravenosas , Masculino , Natriurese/fisiologia , Norepinefrina/sangue , Renina/metabolismo , Sódio/urina , Soluções , Micção/fisiologia
4.
Int J Hyperthermia ; 11(3): 329-35, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7636320

RESUMO

This study was designed to examine the effects of hyperthermia in humans on the production of interleukin (IL)-1 alpha, IL-1 beta, tumour necrosis factor (TNF)beta and interferon (IFN)gamma, determined in supernatants from in vitro lipopolysaccharide or phytohemagglutinin stimulated blood mononuclear cells (BMNC), including the effect of indomethacin in the assays on these cytokines. Eight healthy volunteers were immersed into a hot water bath (water temperature 39.5 degrees C) for 2 h, during which their rectal temperature rose to 39.5 degrees C. On a later day they served as their own controls, being immersed into thermoneutral water (34.5 degrees C) for 2 h. Blood samples were collected before, at body temperatures of 38, 39 and 39.5 degrees C, and 2 h after water immersion and at corresponding time points in the control experiment. Hyperthermia did not influence the production of cytokines from stimulated BMNC. Indomethacin in the assays significantly enhanced the ex vivo production of TNF beta at hyperthermic and thermoneutral conditions; this indomethacin enhanced production of TNF beta declined from pre-value in the hyperthermia experiment compared to the control experiment. Furthermore, indomethacin augmented the production of IFN gamma from stimulated BMNC both in the hyperthermic and the control experiments; the indomethacin effect was, however, not different at the two conditions. It is suggested that hyperthermia alters the sensitivity of BMNC to prostaglandins.


Assuntos
Citocinas/biossíntese , Febre/imunologia , Adulto , Temperatura Corporal , Citocinas/sangue , Temperatura Alta , Humanos , Imersão , Técnicas In Vitro , Indometacina/farmacologia , Interferon gama/biossíntese , Interleucina-1/biossíntese , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Lipopolissacarídeos/farmacologia , Linfotoxina-alfa/biossíntese , Masculino , Fito-Hemaglutininas/farmacologia , Água
5.
Am J Cardiol ; 75(10): 659-64, 1995 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-7900656

RESUMO

We describe the spontaneous long-term changes in right (RV) and left (LV) ventricular performance during a 7-year period after acute myocardial infarction (AMI). Radionuclide ventriculography was performed in the second week after AMI in 201 patients. RV and LV ejection fractions, and LV end-diastolic and end-systolic volumes were determined. A follow-up after 7 years was performed in 55 survivors. Of these, 16 patients were also examined after 1 year. During the 7-year follow-up period, LV ejection fraction decreased from 0.49 to 0.45 (p < 0.01). LV end-diastolic volume increased from 161 to 210 ml (30%) (p < 0.01), and LV end-systolic volume from 83 to 123 ml (48%) (p < 0.01). In patients without recurrent AMI, coronary artery bypass grafting surgery, or angiotensin-converting enzyme inhibitor therapy (n = 37) during follow-up, no change in average LV ejection fraction was observed. Nevertheless, this subgroup had substantial increases in LV end-diastolic volume, from 157 to 190 ml (21%) (p = 0.002) and in LV end-systolic volume, from 80 to 105 ml (31%) (p < 0.001). In a subgroup of patients also reinvestigated after 1 year (n = 16), there was a 15% increase in LV end-diastolic volume the first year after AMI with an additional 10% increase in LV end-diastolic volume between years 1 and 7. Corresponding figures for LV end-systolic volume were 20% and 12%, respectively. Hardly any association was apparent between LV ejection fraction, LV end-diastolic volume, and LV stroke volume at discharge for subsequent LV dilatation.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Infarto do Miocárdio/fisiopatologia , Volume Sistólico , Função Ventricular Esquerda , Função Ventricular Direita , Idoso , Dinamarca/epidemiologia , Feminino , Seguimentos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/mortalidade , Alta do Paciente/estatística & dados numéricos , Ventriculografia com Radionuclídeos/estatística & dados numéricos , Distribuição Aleatória , Sobreviventes/estatística & dados numéricos , Fatores de Tempo
6.
J Appl Physiol (1985) ; 77(6): 2832-9, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7896629

RESUMO

The purpose of this experiment was to investigate whether a graded increase in cardiac distension induced by graded water immersion (WI) could be related to endocrine responses and renal sodium excretion (UNaV). On 3 separate days, nine healthy males were investigated in the upright seated position before, during, and after 3 h of WI to the midchest (CI) or to the neck (NI) or during control. Central venous pressure increased twice as much during NI as during CI. UNaV increased to the same extent during NI compared with CI, whereas urine flow rate, solute-free water clearance, and osmotic excretion increased more during the 2nd h of NI than during CI. During NI, the plasma concentration of atrial natriuretic peptide (ANP) increased twice as much as during CI. The plasma concentrations of aldosterone and norepinephrine were decreased in a similar manner during NI compared with CI. In conclusion, graded cardiac distension induced by graded WI and accompanied by a graded release of ANP was not accompanied by a graded increase in UNaV. Thus either a cardiac distension pressure of approximately one-half of that during NI is enough to induce a maximum UNaV during WI or other stimuli are important. Furthermore, aldosterone and norepinephrine are probably more important mediators of the natriuresis of WI in humans than is ANP.


Assuntos
Volume Sanguíneo , Homeostase , Imersão , Adulto , Sangue/metabolismo , Fenômenos Fisiológicos Cardiovasculares , Glândulas Endócrinas/fisiologia , Hormônios/sangue , Humanos , Rim/metabolismo , Masculino , Natriurese , Pescoço , Tórax
7.
J Appl Physiol (1985) ; 75(1): 349-56, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8376285

RESUMO

On one day six male subjects underwent an upright seated (SEAT) study, and on another day they were subjected to a head-down tilt of 3 degrees (HDT). Compared with SEAT, HDT induced prompt increases in central venous pressure (CVP) from -0.5 +/- 0.8 to 8.3 +/- 0.3 mmHg (P < 0.001) and in arterial pulse pressure of 8-18 mmHg (P < 0.001). CVP stabilized after 6 h at levels 2.4-2.8 mmHg below the peak value. Simultaneously, renal sodium excretion gradually increased over the initial 5 h of HDT and stabilized at a level approximately 125 mumol/min over that of SEAT (P < 0.001). Urine flow rate and solute free water clearance increased during the initial 2-6 h of HDT (P < 0.001) but returned to the level of SEAT thereafter. We concluded that CVP is slightly reduced over 12 h of HDT and that a clear temporal dissociation exists between renal sodium and water handling. We suggest that the combined effect of the sustained suppressions of plasma renin activity and plasma aldosterone and norepinephrine concentrations constitutes a mechanism of the increase in renal sodium excretion.


Assuntos
Volume Sanguíneo/fisiologia , Homeostase/fisiologia , Postura/fisiologia , Adulto , Aldosterona/sangue , Fator Natriurético Atrial/sangue , Pressão Sanguínea/fisiologia , Diurese/fisiologia , Taxa de Filtração Glomerular/fisiologia , Frequência Cardíaca/fisiologia , Hematócrito , Hemodinâmica/fisiologia , Hormônios/fisiologia , Humanos , Rim/fisiologia , Masculino , Natriurese/fisiologia , Norepinefrina/sangue , Renina/sangue , Urodinâmica/fisiologia
8.
Am J Physiol ; 264(5 Pt 2): R1024-30, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8498590

RESUMO

The hypothesis was tested that narrowing of arterial pulse pressure (PP) is a determinant of arginine vasopressin (AVP) release in humans. Six normal males completed a two-step lower body negative pressure (LBNP) protocol of -20 and -50 mmHg, respectively, for 10 min each. None of these subjects experienced presyncopal symptoms. Arterial plasma AVP and plasma renin activity (PRA) (at 2-min intervals) only increased subsequent to a decrease in PP (invasive brachial arterial measurements) and stroke volume (ultrasound Doppler technique, n = 4). Simultaneously, mean arterial pressure did not change. A selective decrease in central venous pressure and left atrial diameter (echocardiography, n = 4) at LBNP of -20 mmHg did not affect AVP or PRA, whereas arterial plasma norepinephrine increased (n = 4). During LBNP, significant (P < 0.05) intraindividual linear correlations were observed between log(AVP) and PP in four of the subjects with r values from -0.75 to -0.99 and between log(PRA) and PP in all six subjects with r values from -0.89 to -0.98. In conclusion, these results are in compliance with the hypothesis that narrowing of PP in humans during central hypovolemia is a determinant of AVP and renin release.


Assuntos
Arginina Vasopressina/sangue , Artérias/fisiologia , Pressão Sanguínea , Pressão Negativa da Região Corporal Inferior , Pulso Arterial , Adulto , Fenômenos Fisiológicos Cardiovasculares , Glândulas Endócrinas/fisiologia , Humanos , Masculino , Concentração Osmolar
9.
Eur J Clin Pharmacol ; 44(1): 7-11, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8436159

RESUMO

The central haemodynamic effects of pindolol and xamoterol have been investigated in patients with postural hypotension. Pindolol is a non-selective beta-adrenoceptor partial agonist, whereas xamoterol is beta 1-selective and possesses a higher degree of agonist activity. The study comprised 16 patients with postural hypotension of different aetiologies. Blood pressure, heart rate and stroke volume were measured in the supine and head-up tilted positions. Left ventricular ejection fraction (LVEF) was measured in the supine position, and vascular resistance, left ventricular volume, and left ventricular contractility were derived. Pindolol and xamoterol were administered intravenously in incremental doses to reach total doses of 0.02 and 0.20 mg.kg-1, respectively. Pindolol showed beta-adrenoceptor antagonistic effects in the supine position through decrements in heart rate from 70 to 66 beats.min-1 and LVEF from 0.57 to 0.52, and reduced mean arterial blood pressure from 103 mm Hg to 93 mm Hg. Xamoterol showed beta-adrenoceptor agonistic effects in the supine position through increments in heart rate from 72 to 90 beats.min-1 and LVEF from 0.58 to 0.66, and raised mean arterial blood pressure from 108 to 123 mm Hg. It is concluded that the degree of agonist activity of a beta-adrenergic agent is of importance if it is given to a patient with postural hypotension.


Assuntos
Hemodinâmica/efeitos dos fármacos , Hipotensão Ortostática/tratamento farmacológico , Pindolol/uso terapêutico , Xamoterol/uso terapêutico , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipotensão Ortostática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Decúbito Dorsal
10.
J Appl Physiol (1985) ; 73(2): 530-8, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1399977

RESUMO

To investigate whether prolonged water immersion (WI) results in reduction of central blood volume and attenuation of renal fluid and electrolyte excretion, these variables were measured in connection with 12 h of immersion. On separate days, nine healthy males were investigated before, during, and after 12 h of WI to the neck or during appropriate control conditions. Central venous pressure, stroke volume, renal sodium (UNaV) and fluid excretion increased on initiation of WI and thereafter gradually declined but were still elevated compared with control values at the 12th h of WI. Atrial natriuretic peptide (ANP) concentration in plasma initially increased threefold during WI and thereafter declined to preimmersion levels, whereas plasma renin activity, plasma aldosterone, and norepinephrine remained constantly suppressed. It is concluded that, compared with the initial increases, central blood volume (central venous pressure and stroke volume) is reduced during prolonged WI and renal fluid and electrolyte excretion is attenuated. UNaV is still increased at the 12th h of WI, whereas renal water excretion returns to control values within 7 h. The WI-induced changes in ANP, plasma renin activity, plasma aldosterone, and norepinephrine may all contribute to the initial increase in UNaV. The results suggest, however, that the attenuation of UNaV during the later stages of WI is due to the decrease in ANP release.


Assuntos
Volume Sanguíneo/fisiologia , Hemodinâmica/fisiologia , Hormônios/fisiologia , Imersão , Rim/fisiologia , Adulto , Aldosterona/sangue , Fator Natriurético Atrial/sangue , Pressão Sanguínea/fisiologia , Monóxido de Carbono , Diurese/fisiologia , Humanos , Masculino , Natriurese , Renina/sangue , Sódio/urina
11.
J Appl Physiol (1985) ; 73(2): 539-44, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1399978

RESUMO

Changes in plasma volume (PV) throughout 12 h of thermoneutral (34.5 degrees C) water immersion (WI) were evaluated in eight subjects by an improved Evans blue (EB) technique and by measurements of hematocrit (Hct), hemoglobin (Hb), and plasma protein concentrations (Pprot). Appropriate time control studies (n = 6) showed no measurable change in PV. At 30 min of immersion, EB measurements demonstrated an increase in PV of 16 +/- 2% (457 +/- 70 ml). Calculations, however, based on concomitant changes in Hct, Hb, and Pprot showed an increase in PV of only 6.9 +/- 0.9 to 10.0 +/- 0.8% at 30 min of WI. PV values based on EB measurements subsequently declined throughout WI to (but not below) the preimmersion level. Concomitantly, changes in PV calculated from Pprot values remained increased, whereas estimations of changes in PV based on Hct and Hb values returned to prestudy levels after 4 h of immersion. It is concluded that PV initially increases by 16 +/- 2% during WI and does not decline below preimmersion and control levels during 12 h of immersion despite a loss of 0.9 +/- 0.2 liter of body fluid. Furthermore, changes in Hct, Hb, and Pprot do not provide accurate measures of the changes in PV during WI in humans.


Assuntos
Volume Sanguíneo/fisiologia , Líquidos Corporais/fisiologia , Imersão/fisiopatologia , Rim/fisiologia , Adulto , Proteínas Sanguíneas/metabolismo , Peso Corporal/fisiologia , Azul Evans , Hematócrito , Hemoglobinas/metabolismo , Humanos , Masculino , Natriurese/fisiologia
12.
Clin Physiol ; 11(6): 579-88, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1769191

RESUMO

The purpose of the study described here was to investigate the reliability of impedance cardiography (IC) in measuring cardiac output (CO) and central blood volume. Absolute values and changes in these variables obtained by impedance cardiography and by isotope- or thermodilution techniques were compared. The reproducibility of IC within the same day was compared with that of isotope dilution and the reproducibility in IC from day to day was derived. Finally, the effects of the readings of impedance tracings by different observers were quantified. The results are based on 270 measurements in 37 healthy subjects and in 25 unmedicated patients with ischaemic heart disease. We obtained significant correlations between absolute values (y = 0.68x + 1.48) and changes (y = 1.00x + 0.0003) in CO measured by IC and isotope- or thermodilution. IC significantly overestimated absolute values of CO (P less than 0.001). We found a qualitative but no quantitative correlation between thoracic fluid volume measured by IC and central blood volume measured by isotope dilution. IC was highly reproducible both when studies were repeated within the same day (SD on differences in CO = 0.36 1 min-1 for IC; SD on differences in CO = 0.30 1 min-1 for isotope dilution) and on different days (SD on differences in CO = 0.45 1 min-1). A low intra-observer variability was found (SD on differences in CO = 0.12 1 min-1). We conclude that impedance cardiography is reliable in measuring changes in cardiac output and thus suitable for repeated measurements in studies on the haemodynamic effects of physiological or pharmacological intervention. Impedance cardiography is sufficiently reliable for comparison of absolute values of CO between different groups of patients. We cannot recommend impedance cardiography for quantitative studies of central blood volume.


Assuntos
Cardiografia de Impedância/normas , Hemodinâmica , Reprodutibilidade dos Testes , Volume Sanguíneo , Débito Cardíaco , Humanos , Termodiluição
14.
Clin Exp Immunol ; 84(1): 175-80, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2015709

RESUMO

This work was designed to test the hypothesis that elevations in body temperature of humans induce immunostimulation. Eight healthy volunteers were immersed in a water bath (water temperature 39.5 degrees C) for 2 h, during which their rectal temperature rose to 39.5 degrees C. On a later day they served as their own controls, being immersed into thermoneutral water (34.5 degrees C) for 2 h. Blood samples were collected before immersion, at body temperatures of 38 degree C, 39 degree C and 39.5 degree C, and 2 h after water immersion. The interleukin-2 (IL-2) enhanced natural killer (NK) cell activity (lysis per fixed number of mononuclear cells), as well as the proportion and total number of NK cells (CD16+ cells), increased significantly during hyperthermia compared with control values. The lymphocyte proliferative responses did not differ significantly between hyperthermia and thermoneutral conditions. The proportion of pan-T (CD3+) cells was maximally depressed 2 h after water immersion. The decreased proportion of CD3+ cells was mainly due to a decreased percentage of CD4+ cells (not significant). The proportion of B cells (CD19+ cells) did not fluctuate significantly, while a marked and significant increase in monocyte proportion (CD14+ cells) was found 2 h after hyperthermia. Two hours after hot water immersion the lymphocyte concentration declined while the neutrophil and monocyte concentrations were augmented. Induced hyperthermia causes significantly increased serum cortisol, plasma norepinephrine and plasma epinephrine concentrations compared to controls. It is possible that the altered immune functions induced by elevated body temperature can be ascribed to altered composition and function of blood mononuclear cells induced by elevated levels of stress hormones.


Assuntos
Hipertermia Induzida , Células Matadoras Naturais/imunologia , Leucócitos Mononucleares/imunologia , Ativação Linfocitária/imunologia , Adulto , Antígenos de Superfície/imunologia , Epinefrina/sangue , Humanos , Hidrocortisona/sangue , Interleucina-2/farmacologia , Masculino , Norepinefrina/sangue
15.
Liver ; 10(4): 217-20, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2215093

RESUMO

Liver biopsy with the 0.6 mm (23 gauge) Surecut needle was compared to conventional Menghini biopsy in the diagnosis of cirrhosis. Seventy-seven consecutive patients (mainly alcoholics) with a clinical indication for liver biopsy had both biopsies performed simultaneously. In 71 patients sufficient material for a morphological diagnosis concerning liver architecture was obtained with both biopsy techniques (Surecut insufficient in 5 cases and Menghini insufficient in 2 cases). The biopsies were classified as cirrhosis or non-cirrhosis. There was agreement in 69 cases (97%, confidence limits 90-100%). Using the result of the Menghini biopsy as the final diagnosis, the predictive values for a positive and negative diagnosis for the Surecut needle were 96% and 98%, respectively. There were no complications to either of the biopsies. It is suggested that the 0.6 mm Surecut biopsy may be used in the diagnosis of cirrhosis in cases where conventional Menghini needle biopsy is contraindicated.


Assuntos
Biópsia por Agulha/métodos , Cirrose Hepática/patologia , Fígado/patologia , Feminino , Humanos , Cirrose Hepática/diagnóstico , Masculino , Pessoa de Meia-Idade , Agulhas
16.
Clin Radiol ; 41(5): 341-3, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-2354603

RESUMO

In order to establish the natural course of radionuclide bone scanning images after total knee replacement 41 consecutive patients were scheduled for examination 3, 7, 12 and 24 months after surgery. The mean age was 69 years (range 50-80 years); the female:male ratio was 4:1. Thirty-two patients completed the entire program. A total of 143 99Tcm medronic acid complex scintigrams was performed. No significant difference between the grades of total scintigraphic uptake at any of the four examinations nor any difference between the first and the last examinations could be demonstrated (P = 0.58, Friedman test and P = 0.20, Wilcoxon test, respectively). Twelve months after surgery one fifth of the knees still demonstrated definitely increased scintigraphic uptake and 24 months after surgery 12.5% of the knees had definitely increased uptake. We believe that the increased uptake seen for a variable length of time after surgery limits the usefulness of radionuclide bone scanning in the evaluation of total knee replacement.


Assuntos
Articulação do Joelho/diagnóstico por imagem , Prótese do Joelho , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Cintilografia , Medronato de Tecnécio Tc 99m , Fatores de Tempo
17.
Resuscitation ; 19(2): 115-23, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2160708

RESUMO

Cerebral blood flow (CBF) and cardiac output (CO) were measured during cardiopulmonary resuscitation in patients who were unsuccessfully resuscitated by use of C14-iodoantipyrine injected into the left ventricle. CO varied between 1.3 and 2.2 l/min with mean 1.8 +/- 0.6 l/min (+/- SD) (28 ml/kg/min). The cortical CBF was found between 14 and 211 ml 100 g-1.min-1 with mean 42 ml 100 g-1.min-1 and mean white matter CBF equal to 27 ml 100 g-1.min-1. It is suggested that the external cardiac massage in humans may be of poor efficacy in terms of brain revival. Cortical CBF after long-lasting cardiopulmonary resuscitation showed signs of maldistribution suggestive of a patchy and incomplete perfusion.


Assuntos
Circulação Cerebrovascular/fisiologia , Ressuscitação , Idoso , Antipirina/análogos & derivados , Gasometria , Radioisótopos de Carbono , Débito Cardíaco/fisiologia , Cardioversão Elétrica , Feminino , Massagem Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade
18.
J Appl Physiol (1985) ; 68(2): 527-32, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2318763

RESUMO

Although angiotensin II is a potent vasoconstrictor agent in all tissues, including the human forearm, equivocal effects on forearm blood flow (FBF) have been found after angiotensin blockade. In 13 healthy Na(+)-depleted subjects FBF was measured by the 133Xe washout technique; subcutaneous and muscle blood flows were determined separately. FBF was measured during supine rest, after the arm was lowered, and during lower body negative pressure (LBNP). The measurements were repeated during intra-arterial saralasin infusion in six subjects and after intravenous administration of enalapril in seven subjects. FBF decreased and forearm vascular resistance (FVR) increased during arm lowering and LBNP, as the result of local and central adrenergic reflexes, respectively. We observed similar FBF and FVR values after both saralasin and enalapril, except for a decrease in FVR at rest after enalapril. It is concluded that, in the human forearm, angiotensin II is not necessary for sympathetic vasoconstrictor reflexes but may, through a central effect, have some influence on arteriolar tone at rest.


Assuntos
Angiotensina II/antagonistas & inibidores , Circulação Sanguínea/fisiologia , Descompressão , Enalapril/farmacologia , Antebraço/irrigação sanguínea , Pressão Negativa da Região Corporal Inferior , Sistema Renina-Angiotensina/fisiologia , Saralasina/farmacologia , Adulto , Circulação Sanguínea/efeitos dos fármacos , Feminino , Humanos , Masculino , Resistência Vascular/fisiologia
19.
Gastroenterology ; 97(6): 1506-13, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2583416

RESUMO

The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed according to the kinetic theory as the product of cardiac output and mean transit time of the central vascular bed. Central blood volume was significantly smaller in patients with cirrhosis than in controls (mean 21 vs. 27 ml/kg estimated ideal body weight, p less than 0.001; 25% vs. 33% of the total blood volume, p less than 0.0001). The lowest values (18 ml/kg) were found in patients with gross ascites and a reduced systemic vascular resistance. In patients with cirrhosis central blood volume was inversely correlated to the hepatic venous pressure gradient (r = -0.41, p less than 0.01), and the total blood volume was inversely correlated to the systemic vascular resistance (r = -0.49, p less than 0.001), the latter being significantly reduced in the patient group. Patients with cirrhosis apparently are unable to maintain a normal central blood volume. This may be due to arteriolar vasodilation, portosystemic collateral flow, or sequestration of fluid in the peritoneal cavity, or any combination thereof. The present results indicate that central circulatory underfilling is an integral part of the hemodynamic and homeostatic derangement observed in cirrhosis.


Assuntos
Volume Sanguíneo/fisiologia , Hemodinâmica , Cirrose Hepática/fisiopatologia , Adulto , Idoso , Ascite/fisiopatologia , Velocidade do Fluxo Sanguíneo , Diuréticos/uso terapêutico , Feminino , Humanos , Cirrose Hepática/tratamento farmacológico , Masculino , Pessoa de Meia-Idade
20.
Clin Orthop Relat Res ; (247): 163-7, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2791385

RESUMO

Ninety-eight patients scheduled for elective hip arthroplasty receiving either general or regional anesthesia and graded compression stockings as the only thromboprophylactic treatment were screened for postoperative deep-venous thrombosis with 99mTc-plasmin scintimetry. The diagnosis of deep-venous thrombosis was established by phlebography and the diagnosis of pulmonary embolism by pulmonary perfusion and ventilation scintigraphy. Of 65 patients surgically treated under general anesthesia, 20 (31%) developed deep-venous thrombosis and six developed pulmonary embolism. Of 33 patients surgically treated using regional anesthesia, three (9%) developed deep-venous thrombosis and one developed a pulmonary embolus. The number of patients developing deep-venous thrombosis was significantly lower in the group receiving regional anesthesia compared with the group receiving general anesthesia. The results indicate the beneficial effects on the incidence of postoperative thromboembolic complications following elective hip surgery from the use of regional anesthesia and graded compression stockings.


Assuntos
Anestesia Epidural , Bandagens , Prótese de Quadril , Osteoartrite/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Tromboembolia/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tromboembolia/etiologia
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