Biomedical subjects

M Leeman

Publications and source records attributed to M Leeman.

At least 19 recordsLinked to original sources

PubMed2006

[Control of hypertension in nursing homes].

In a cross sectional study we determined prevalence of hypertension among institutionalized old subjects. Prevalence of hypertension was 69%. Among detected hypertensive patients, 76% received an antihypertensive drug treatment. 61% of the declared hypertensive patients and 80% of the treated hypertensive patients had their blood pressure controlled. The general practitioners should better detect and treat this common geriatric problem associated with a high comorbidity.

Aged, 80 and over↗

PubMed2006

[Cardiovascular diseases: which prevention for which patient?].

Several cardiovascular risk factors have been identified, which can be influenced by lifestyle modifications and medication. Many cardiovascular events could be prevented using appropriate preventive measures. The distinction between primary and secondary prevention is gradually disappearing. Lifestyle modifications must be recommended in all patients, and, depending on the individual's risk profile, drug interventions can also be used to improve cardiovascular prognosis, including antihypertensive drugs, lipid-lowering therapies, hypoglycaemic drugs, and antithrombotic agents. This article summarises the most recent guidelines on the prevention of common cardiovascular diseases: coronary artery disease, stroke, and peripheral artery disease.

Cardiovascular Diseases↗

PubMed2005

Vinegar dressing and cold storage of potatoes lowers postprandial glycaemic and insulinaemic responses in healthy subjects.

OBJECTIVE: To investigate the effects of cold storage and vinegar addition on glycaemic and insulinaemic responses to a potato meal in healthy subjects. SUBJECTS AND SETTING: A total of 13 healthy subjects volunteered for the study, and the tests were performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. Experimental design and test meals:The study included four meals; freshly boiled potatoes, boiled and cold stored potatoes (8 degrees C, 24 h), boiled and cold stored potatoes (8 degrees C, 24 h) with addition of vinaigrette sauce (8 g olive oil and 28 g white vinegar (6% acetic acid)) and white wheat bread as reference. All meals contained 50 g available carbohydrates and were served as a breakfast in random order after an overnight fast. Capillary blood samples were collected at time intervals during 120 min for analysis of blood glucose and serum insulin. Glycaemic (GI) and insulinaemic indices (II) were calculated from the incremental areas using white bread as reference. RESULTS: Cold storage of boiled potatoes increased resistant starch (RS) content significantly from 3.3 to 5.2% (starch basis). GI and II of cold potatoes added with vinegar (GI/II=96/128) were significantly reduced by 43 and 31%, respectively, compared with GI/II of freshly boiled potatoes (168/185). Furthermore, cold storage per se lowered II with 28% compared with the corresponding value for freshly boiled potatoes. CONCLUSION: Cold storage of boiled potatoes generated appreciable amounts of RS. Cold storage and addition of vinegar reduced acute glycaemia and insulinaemia in healthy subjects after a potato meal. The results show that the high glycaemic and insulinaemic features commonly associated with potato meals can be reduced by use of vinegar dressing and/or by serving cold potato products.

Acetic Acid↗

PubMed2004

Effects of low-dose dopamine on ventilation in patients with chronic obstructive pulmonary disease.

BACKGROUND: Dopamine plays an important role in the regulation of respiration and low-dose dopamine infusion is associated with a decreased respiratory drive response to hypoxia in animals and humans. The effects of dopamine on ventilation in patients with chronic obstructive pulmonary disease (COPD) is unknown. We tested the hypothesis that dopamine inhibits ventilation in patients with COPD. MATERIALS AND METHODS: In a double-blinded, cross-over, placebo-controlled, randomized study we studied nine patients with decompensated COPD, ventilated in the pressure support mode in the intensive care unit (ICU) and five ambulatory patients with stable COPD. All patients received 5 micro g kg(-1) min(-1) of dopamine or an equivalent volume of 5% glucose solution. RESULTS: In the mechanically ventilated COPD patients, there was no difference in the effects of dopamine compared with placebo on blood pressure, heart rate, minute ventilation (-0.5 +/- 1.1 vs. -0.2 +/- 0.9 L min(-1), P = 0.46, respectively), respiratory rate (-0.4 +/- 2.7 vs. -0.3 +/- 2.1 min(-1), P = 0.96), PaO(2) (-5 +/- 4 vs. -5 +/- 10 mmHg, P = 0.90, respectively), or PaCO(2) (-0.7 +/- 1.4 vs. -1.0 +/- 3.4 mmHg, P = 0.83, respectively). In spontaneously breathing stable patients, dopamine increased systolic blood pressure (P = 0.02) but did not influence other haemodynamic and respiratory variables. CONCLUSION: Although low-dose dopamine has been shown to depress ventilation in a variety of conditions, it does not compromise ventilation in COPD patients either breathing spontaneously or when weaned using pressure support ventilation.

Aged↗

PubMed2004

[Hypertensive crisis: when and how to treat?].

A hypertensive emergency is a situation in which uncontrolled hypertension is associated with acute end-organ damage, such as aortic dissection, pulmonary edema, acute coronary syndromes, cerebral infarction or hemorrhage, hypertensive encephalopathy, acute renal failure and eclampsia. With the exception of stroke, blood pressure must be reduced quickly, usually by using intravenous antihypertensive agents. Blood pressure reduction should be gradual while maintaining organ perfusion, which may be easily compromised in elderly and chronically hypertensive patients. In the absence of new or worsening end-organ injury, the indication of immediate therapy should be carefully evaluated. If indicated, the use of an orally long-acting antihypertensive agent is preferred to avoid an acute and unpredictable fall in blood pressure. In particular, the use of short-acting nifedipine should be condemned.

Antihypertensive Agents↗

PubMed2003

Endogenous endothelins and nitric oxide in hypoxic pulmonary vasoconstriction.

The effects of endothelin receptor blockade on the pulmonary circulation have been reported variably, possibly in relation to a more or less important associated release of endogenous nitric oxide (NO). The aim of this study was to test whether endothelin antagonism would inhibit hypoxic pulmonary vasoconstriction, and if it would not, then would it do so after NO synthase inhibition. Hypoxic pulmonary vasoconstriction (HPV) was evaluated in anesthetised dogs by the increase in the mean pulmonary artery pressure (Ppa) minus occluded Ppa (Ppao) gradient in response to hypoxia (inspiratory oxygen fraction of 0.1) at constant pulmonary blood flow. Bosentan, an endothelin A and B receptor antagonist, did not affect baseline Ppa, Ppao or systemic arterial pressure (Psa) and did not alter HPV (n=8). The NO synthase inhibitor N(G)-nitro-L-arginine (L-NA) did not affect baseline Ppa and Ppao, but increased Psa and enhanced HPV (n=12). The addition of bosentan in these dogs did not affect baseline Ppa or Ppao, but decreased Psa and inhibited HPV. Exhaled NO was decreased by L-NA and by bosentan and abolished by L-NA+bosentan (n=9). The authors conclude that endogenous nitric oxide is released by, and opposes the vasoconstricting effects of, endothelins in vivo, reducing systemic blood pressure and limiting hypoxic pulmonary vasoconstriction.

Animals↗

PubMed2002

Prevalence of hypertension in the adult population of Belgium: report of a worksite study, Attention Hypertension.

Hypertension remains a major cause of cardiovascular morbidity in Belgium. Information on the prevalence of hypertension in the working population is desirable. A worksite study of hypertension prevalence was carried out in Belgium where 3472 individuals were screened for 1 week. The result was that high blood pressure (> or = 140/90 mm Hg) was identified in approximately one-third of the men and one-quarter of the women even though the majority of subjects had no recorded history of hypertension. Associations were identified between age and systolic blood pressure and, in men, between systolic blood pressure and alcohol consumption. Most participants in the survey were unaware of their serum cholesterol level. The results of this survey suggest that a large proportion of subjects with high blood pressure in the Belgian working population remain unidentified and indicate a lack of awareness about other cardiovascular risk factors.

Adolescent↗

PubMed2002

[Resistant arterial hypertension].

Many patients are considered to have resistant hypertension when their blood pressure remains elevated despite the use of multiple antihypertensive agents. Several factors can interfere with optimal control of blood pressure, some being patient-related, such as poor compliance, other being physician-related, such as the reluctance to increase treatment. These factors are often identified using a systematic approach, so that truly resistant hypertension is, in fact, uncommon.

Drug Resistance↗

PubMed2002

[The intensive care department].

Intensive Care Departments are designed for the care of the critically ill, and are equipped with all the material necessary for monitoring and treatment, as well as specially trained medical, nursing, and paramedical staff. With a team of more than 170 highly qualified staff, the Department of Intensive Care at Erasme Hospital, has acquired a national and international reputation in the fields of clinical and experimental research and education, as well as for its standards of clinical practice. Clinical and experimental studies have been high in quantity and quality, and have covered all the key areas in the field of intensive care medicine: severe sepsis, multiple organ failure, transport and metabolism of oxygen, systemic and regional hemodynamic alterations (pulmonary, cerebral, hepato-splanchnic,...), metabolic disorders,... not forgetting issues associated with the complexities of medical ethics. The quality of care, clinical, scientific and personal, offered by the Department of Intensive Care at Erasme Hospital has earned it the high level reputation for which it is renowned in Belgium, and indeed worldwide.

Belgium↗

PubMed2001

[Peripartum cardiomyopathy].

Peripartum cardiomyopathy is a rare, potentially life-threatening cardiomyopathy of unknown cause. Diagnosis includes clinical (development of cardiac failure in the last month of pregnancy or within 5 months after delivery, absence of an identifiable cause of cardiac failure and absence of recognizable heart disease prior to the last month of pregnancy) and echographic (left ventricular systolic dysfunction) criteria. Therapy is standard, except for angiotensin converting enzyme inhibitors, which should be avoided at the end of pregnancy, and heart transplantation if medical treatment fails. We report the case of a 24 year-old woman who required left ventricular assistance as a bridge before cardiac transplantation.

Adult↗

PubMed2000

Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics.

The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multi-centre, prospective, randomized, double-blind, parallel-group study. The primary objective of SCOPE is to assess the effect of the angiotensin II type 1 (AT1) receptor blocker, candesartan cilexetil 8-16 mg once daily, on major cardiovascular events in elderly patients (70-89 years of age) with mild hypertension (DBP 90-99 and/or SBP 160-179 mmHg). The secondary objectives of the study are to test the hypothesis that antihypertensive therapy can prevent cognitive decline (as measured by the Mini Mental State Examination, MMSE) and dementia, and to assess the effect of therapy on total mortality, myocardial infarction (MI), stroke, renal function, and hospitalization. A total of 4964 patients from 15 participating countries were recruited during the randomization phase of SCOPE, exceeding the target population of 4000. The mean age of the patients at enrolment was 76 years, the ratio of male to female patients was approximately 1:2, and 52% of patients were already being treated with an antihypertensive agent at enrolment. The majority of patients (88%) were educated to at least primary school level. At randomization, mean sitting blood pressure values were SBP 166 mmHg and DBP 90 mmHg, and the mean MMSE score was 28. Previous cardiovascular disease in the study population included myocardial infarction (4%), stroke (4%) and atrial fibrillation (4%). Men, more often than women, had a history of previous MI, stroke and atrial fibrillation. A greater percentage of men were smokers (13% vs 6% in women) and had attended university (11% vs 3% of women). Of the randomized patients, 21% were 80 years of age. In this age group smoking was less common (4% vs 10% for 70-79-year-olds) and fewer had attended university (4% vs 7% for 70-79-year-olds). The incidence of MI was similar in both age groups. However, stroke and atrial fibrillation had occurred approximately twice as frequently in the older patients. The patients' mean age at baseline was similar in the participating countries, and most countries showed the approximate 1:2 ratio for male to female patients. There was also little inter-country variation in terms of mean SBP, DBP or MMSE score. However, there was considerable regional variation in the percentage of patients on therapy prior to enrolment.

Aged↗

PubMed1999

Study on COgnition and Prognosis in the Elderly (SCOPE).

The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multicentre, prospective, randomized, double-blind, parallel-group study designed to compare the effects of candesartan cilexetil and placebo in elderly patients with mild hypertension. The primary objective of the study is to assess the effect of candesartan cilexetil on major cardiovascular events. The secondary objectives of the study are to assess the effect of candesartan cilexetil on cognitive function and on total mortality, cardiovascular mortality, myocardial infarction, stroke, renal function, hospitalization, quality of life and health economics. Male and female patients aged between 70 and 89 years, with a sitting systolic blood pressure (SBP) of 160-179 mmHg and/or diastolic blood pressure (DBP) of 90-99 mmHg, and a Mini-Mental State Examination (MMSE) score of 24 or above, are eligible for the study. The overall target study population is 4000 patients, at least 1000 of whom are also to be assessed for quality of life and health economics data. After an open run-in period lasting 1-3 months, during which patients are assessed for eligibility and those who are already on antihypertensive therapy at enrolment are switched to hydrochlorothiazide 12.5 mg o.d., patients are randomized to receive either candesartan cilexetil 8 mg once daily (o.d.) or matching placebo o.d. At subsequent study visits, if SBP remains >160 mmHg, or has decreased by <10 mmHg since the randomization visit, or DBP is >85 mmHg, study treatment is doubled to candesartan cilexetil 16 mg o.d. or two placebo tablets o.d. Recruitment was completed in January 1999. At that time 4964 patients had been randomized. All randomized patients will be followed for an additional 2 years. If the event rate is lower than anticipated, the follow-up will be prolonged.

Aged↗

PubMed1999

Arterial baroreflex control of the sinus node during dobutamine exercise stress testing.

The contributions of increases in circulating catecholamines, changes in central command, and muscle afferents on baroreflex control of the sinus node during exercise are unclear. We used a dobutamine infusion to induce hemodynamic changes comparable to those of moderate physical exercise in the absence of changes in central command and muscle afferents in 13 healthy subjects. Dobutamine (up to 9 microg/kg body weight per minute) increased systolic blood pressure, shortened the RR interval, increased systolic blood pressure variability, but blunted RR interval variability (P<0.05 versus placebo). Consequently, dobutamine decreased the coherence between variations in systolic blood pressure and RR interval and decreased arterial baroreflex sensitivity from 12+/-2 to 3+/-1 ms/mm Hg (P<0.01). The largest increases in systolic blood pressure with dobutamine were paralleled by the greatest impairments in arterial baroreflex sensitivity (0. 50<r<0.56, P<0.01). The chronotropic effects of dobutamine prevented a reflex bradycardia in response to the blood pressure increase. However, less predominant low-frequency oscillations in systolic blood pressure (P<0.0001) suggested preserved sympathetic withdrawal in response to the blood pressure increase induced by dobutamine. In conclusion, this study revealed that a shift in the operating point of the arterial baroreceptors and the chronotropic effects of adrenergic stimulation impair baroreflex control of the sinus node during dobutamine exercise stress testing. Baroreflex control of the sinus node is not reset when hemodynamic characteristics of exercise are reproduced in the absence of modifications in central command and muscles afferents.

Adult↗

PubMed1999

Inhibition of cyclooxygenase and nitric oxide synthase in hypoxic vasoconstriction and oleic acid-induced lung injury.

Cyclooxygenase (COX) products and nitric oxide (NO) inhibit hypoxic pulmonary vasoconstriction (HPV), and their release could contribute to alterations in gas exchange in lung injury. We tested the hypothesis that combined blockade of COX and NO synthase (NOS) could further increase HPV and better protect gas exchange in lung injury than could blockade of either COX or NOS alone. We determined pulmonary vascular pressure-flow relationships in pentobarbital-anesthetized and ventilated dogs submitted to hypoxic challenges before and after administration of solvent (n = 4), indomethacin alone (2 mg/kg intravenously, n = 8), Nomega-nitro-L-arginine (L-NA) alone (10 mg/kg intravenoulsy, n = 8), indomethacin followed by L-NA (n = 8), and L-NA followed by indomethacin (n = 8). All of the dogs so treated then received oleic acid (0.06 ml/kg intravenously) to induce lung injury. Blood flow was manipulated by establishing a femoral arteriovenous bypass or by inflating an inferior vena caval balloon. Gas exchange was evaluated by measuring arterial PO2 and intrapulmonary shunt (using the inert gas sulfur hexafluoride) at identical cardiac outputs. The magnitude of HPV was not affected by solvent. Indomethacin and L-NA given separately enhanced HPV. L-NA added to indomethacin further enhanced HPV, as did indomethacin added to L-NA. After oleic acid-induced lung injury, gas exchange deteriorated less in dogs pretreated with indomethacin than in dogs pretreated with solvent or with L-NA alone. These results suggest that in pentobarbital-anesthetized dogs: (1) the magnitude of HPV is limited by the corelease of COX metabolites and of NO; and (2) inhibition of COX, but not of NOS, attenuates the deterioration of gas exchange in oleic acid-induced lung injury.

Animals↗

PubMed1999

Pulmonary hypertension in acute respiratory distress syndrome.

A mild degree of pulmonary hypertension is commonly observed in patients with acute respiratory distress syndrome (ARDS). Vasoconstriction plays a dominant role in increasing the mean closing pressure of the pulmonary vascular bed. Pulmonary hypertension increases right ventricular afterload, but right ventricular failure rarely occurs in patients with ARDS. Although the initial magnitude of pulmonary hypertension is not an indicator of mortality, pulmonary artery pressure increases in nonsurvivors but not in survivors when followed for 7 days. Pulmonary vascular tone is closely related to gas exchange, and the increase in pulmonary artery pressure is a protective mechanism to minimize ventilation-perfusion mismatching in ARDS. Consequently, generalized pulmonary vasodilation by intravenous vasodilators aggravates arterial hypoxaemia. Conversely, selective administration of vasodilators, such as inhaled nitric oxide, in well-ventilated lung units improves gas exchange by diverting pulmonary blood flow to better oxygenated regions. However, preliminary results from large prospective randomized controlled trials indicate that inhaled nitric oxide does not reduce mortality nor the duration of mechanical ventilation in patients with ARDS.

Emergency Service, Hospital↗

PubMed1999

[Regulation of pulmonary circulation by the vascular endothelium].

The function of the endothelial mediators on lung vessels is progressively understood. Our experimental results, in agreement with those from other laboratories, show that prostacyclin and nitric oxide do not affect basal pulmonary vascular tone, but that they limit the pulmonary hypertension secondary to alveolar hypoxia, or to lung injury. The role of endothelins remains harder to define, partly because their vascular effects are opposed by nitric oxide in intact animals.

Animals↗

PubMed1999

[Physiopathology of pulmonary arterial hypertension and gas exchange in acute pulmonary embolism].

Pulmonary embolism alters the distribution of ventilation/perfusion relationships, and increases pulmonary vascular resistance. These changes lead to hypoxemia and hypocapnia, and eventually, to right heart failure. The thin-walled and compliant right ventricle adapts to any increase in afterload by dilatation and decreased stroke volume, but this is largely prevented or delayed by the pulmonary circulation being a low resistance, recruitable and distensible circuit. Pulmonary embolism cannot be associated with a mean pulmonary artery pressure higher than 40 mmHg. More severe pulmonary hypertension indicates the presence of a hypertrophied right ventricle in the context of preexistent cardiac or pulmonary disease. Gas exchange is initially affected because of increased ventilation/perfusion ratios in embolized lung areas, and decreased ventilation/perfusion ratios in remaining non embolized lung areas. Both physiologic shunt and physiologic dead space increase accordingly, resulting in hypoxemia and hypocapnia. However, these changes are rapidly affected by an increase in ventilation, and by a "pneumoconstriction" which decreases physiologic dead space in embolized areas. In addition, a series of secondary alterations contribute to increase perfusion to lung units with low ventilation/perfusion ratios, thereby aggravating hypoxemia, while hypocapnia persists.

Acute Disease↗

PubMed1998

Pharmacologic strategies in acute respiratory distress syndrome.

Treatment of the acute respiratory distress syndrome includes both supportive measures and correction of the underlying cause. Various pharmacological interventions have been proposed to limit the severity of lung injury and enhance the healing process, including exogenous surfactant, inhaled vasodilators (mainly nitric oxide), corticosteroids, prostaglandin E1, antioxidants (N-acetylcysteine), ketoconazole and other substances. Some of these interventions are administered via the airways, for example inhaled nitric oxide or liquid ventilation with perfluorocarbons. Some have beneficial effects on surrogate end-points such as pulmonary gas exchange. However, in large prospective trials none of these pharmacological approaches have resulted in significantly improved survival in acute respiratory distress syndrome patients.

Journal Article↗