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Biomedical subjects

J A Rauwerda

Publications and source records attributed to J A Rauwerda.

At least 37 records · Page 2Linked to original sources
PubMed2003

Asymmetrical dimethylarginine (ADMA) in critically ill patients: high plasma ADMA concentration is an independent risk factor of ICU mortality.

BACKGROUND AND AIMS: Accumulation of asymmetrical dimethylarginine (ADMA) has been linked to endothelial dysfunction, and is an important risk factor for cardiovascular disease. Its elimination from the body is dependent on urinary excretion and degradation by the enzyme dimethylarginine dimethylaminohydrolase. This enzyme is highly expressed in the liver, and in rat studies a high net hepatic uptake of asymmetrical dimethylarginine was found. In critically ill patients, we investigated the relation between indicators of renal and hepatic dysfunction and plasma ADMA concentration, and tested the association between ADMA concentration and outcome. METHODS: We prospectively collected blood samples from a cross-section of critically ill patients (n=52) with clinical evidence of dysfunction of more than two organs. We identified correlates of plasma ADMA concentration with laboratory values, organ failures score and outcome by univariate and multiple regression analyses. RESULTS: In critically ill patients, plasma ADMA concentration was independently related to the presence of hepatic failure (b=0.334, 95% CI: 0.207-0.461; P<0.001), and to lactic acid (b=0.395, 95% CI: 0.230-0.560; P<0.001) and bilirubin (b=0.121, 95% CI: 0.031-0.212; P=0.009) concentration as markers of hepatic function. Twenty-one (40%) patients deceased during their ICU stay. In a logistic regression model, plasma ADMA ranked as the first and strongest predictor for outcome, with a 17-fold (95% CI: 3-100) increased risk for ICU death in patients who were in the highest quartile for ADMA. CONCLUSIONS: In critically ill patients, plasma ADMA concentration is a strong and independent risk factor for ICU mortality, and hepatic dysfunction is the most prominent determinant of ADMA concentration in this population.

Adult↗
PubMed2002

[One hundred years of the Association of Surgeons in the Netherlands. VII. Vascular surgery].

The Dutch Society for Vascular Surgery was founded in 1981, as the first daughter of the Association of Surgeons in the Netherlands. Twenty years of vascular surgery show a broad perspective. Aside from the traditional handywork--central vascular reconstruction, bypass surgery (especially in the legs), and carotid surgery--, there have been many developments. Operations are less invasive and vascular surgeons are cooperating more and more intensively with other medical disciplines, especially radiology. Examples are the endovascular treatment of abdominal aortic aneurysm, in which an endoprosthesis is inserted via minute incisions in the groin by the vascular surgeon and an (interventional) radiologist together. In addition, interventions such as percutaneous transluminal angioplasty and stenting as well as new diagnostic possibilities (e.g. MRA) strengthen the cooperation with the radiologists. The multidisciplinary approach is also extremely important in other areas. Vascular surgeons team up with internal-medicine specialists (diabetes, hypertension, lipid metabolism disorders, thrombotic syndromes, etc.), rehabilitation specialists and podotherapists (in cases of diabetic foot and amputation), vascular laboratory technicians (diagnostics and follow-up by means of doppler and duplex techniques), and neurologists (cerebrovascular diseases). In the vascular centres, patients are treated effectively by a multidisciplinary team that draws up a plan for diagnosis and treatment. The two-year postgraduate course in vascular surgery is one of the tools used to guarantee and improve the high standard of quality. To this end, cooperation within Europe in the European Society for Vascular Surgery and the development and organisation of European examinations in vascular surgery are also of the essence.

Angioplasty, Balloon↗
PubMed2002

Aortic aneurysm pulsatile wall motion imaged by cine MRI: a tool to evaluate efficacy of endovascular aneurysm repair?

OBJECTIVES: to evaluate cine MRI as a means of determining the two-dimensional pulsatile wall motion (2D-PWM) of abdominal aortic aneurysm (AAA). DESIGN: prospective study of 21 patients with AAA. 2D-PWM was defined as change in cross-sectional area. RESULTS: the median diastolic area was 28 cm(2) (intraquartile range, IQR, 22-31 cm(2)) and the median (IQR) 2D-PWM was 0.25 (0.10-0.40) cm(2). Assuming that the AAA is circular in cross-section this represents a median (IQR) diameter increase of 0.3 (0.1-0.4) mm. However, local wall displacements up to 2 mm were present in varying directions, without significant change in surface area. CONCLUSION: AAA PWM is negligible and may not therefore be a potential tool to assess efficacy of endovascular aneurysm exclusion.

Aged↗
PubMed2002

Familial abdominal aortic aneurysm: a systematic review of a genetic background.

BACKGROUND: Familial clustering of the abdominal aortic aneurysm (AAA) is clear, 12-19% of AAA patients have one or more first-degree relatives with an aneurysm and 4-19% is detected with ultrasound screening. OBJECTIVES: To review the genetic background of AAA. DESIGN, METHODS AND MATERIALS: Computer searches of the MEDLINE, EMBASE, SUMsearch database and the Cochrane Library and searched reference lists of English language articles concerning the genetics of AAA, candidate gene approach and linkage analysis. RESULTS: Brothers of AAA patients are at high risk to develop an AAA. The candidate gene approach was performed to detect defects in one of the components of the connective tissue, i.e. type I and III collagen, elastin and fibrillin, the inflammatory cell-derived matrix metalloproteinase, there inhibitors, auto-immune components and components related to atherosclerosis. CONCLUSION: These studies give us insight in the pathology but do not lead to the specific genetic factor(s) responsible for (familial) AAA. Considering the supposed autosomal dominant inheritance, a gene mutation in one of the structural proteins of the connective tissue is expected. In the future, linkage analysis may resolve the genetic background of AAA.

Aortic Aneurysm, Abdominal↗
PubMed2001

Posterior approach for the simultaneous, bilateral thoracoscopic sympathectomy.

If there is an indication for sympathectomy in the case of severe hyperhidrosis or rubeosis, in our opinion the posterior approach is preferable because of the advantages in surgical technique and anesthesia. Bilateral treatment can be accomplished in a single admission, with all the concomitant advantages.

Adolescent↗
PubMed2001

Low arginine plasma levels do not aggravate renal blood flow after experimental renal ischaemia/reperfusion.

BACKGROUND: Ischaemic renal dysfunction is present in many clinical settings, including cardiovascular surgery. Renal hypoperfusion seems to be the most important pathophysiologic mechanism. Arginine plasma levels are rate limiting for NO synthesis, and low arginine plasma levels are seen after major vascular surgery. OBJECTIVE: to establish the effects of low arginine plasma levels on renal blood flow after renal ischaemia/reperfusion. DESIGN: Wistar rats were used in this unilateral renal ischaemia/reperfusion model. After 70 min of ischaemia, the kidney was reperfused for 150 min. Arginase infusion was used to lower arginine plasma levels. Blood flow measurement was performed at the end of the experiment using radiolabelled microspheres. Additional experiments were performed for histopathology. RESULTS: Arginase efficiently decreased arginine plasma levels to about 50% of normal. There was a lower blood flow in the ischaemic kidney than the contralateral (non-ischaemic) kidney. Lowering arginine plasma levels did not reduce renal blood flow in the ischaemic kidney. Renal histopathology was not influenced by lowered arginine plasma levels. CONCLUSIONS: Lowering arginine plasma levels did not affect blood flow or histology following renal ischaemia and reperfusion.

Animals↗
PubMed2001

Decreased smooth muscle cell/extracellular matrix ratio of media of femoral artery in patients with atherosclerosis and hyperhomocysteinemia.

The aim of this study was to determine whether the morphology of the muscular femoral artery in patients with atherosclerosis and hyperhomocysteinemia differs from that of atherosclerotic vessels from patients with normal homocysteine levels. Whole-vessel biopsies of the superficial femoral artery were taken from patients with symptomatic atherosclerotic disease with and without hyperhomocysteinemia and from patients without atherosclerosis from traumatic amputations. The morphology of these specimens was studied qualitatively by light and electron microscopy and quantitatively by light microscopy in combination with a video overlay system. Atherosclerotic lesions in patients with hyperhomocysteinemia were morphologically similar to those in patients with normal homocysteine levels, except for a significantly decreased smooth muscle cell/extracellular matrix ratio of the media in hyperhomocysteinemic patients (P=0.02 versus normohomocysteinemic atherosclerotic group and P=0.001 versus group without a history of cardiovascular disease). Hyperhomocysteinemia is associated with a significant decrease of the smooth muscle cell/extracellular matrix ratio of the media of muscular femoral arteries without significant changes in medial thickness. Further investigations should concentrate on the cause of this newly discovered phenomenon and its impact on vascular compliance.

Adult↗
PubMed2001

Long-term homocysteine-lowering treatment with folic acid plus pyridoxine is associated with decreased blood pressure but not with improved brachial artery endothelium-dependent vasodilation or carotid artery stiffness: a 2-year, randomized, placebo-controlled trial.

Homocysteine is associated with atherothrombotic disease, which may be mediated through associations of homocysteine levels with blood pressure, endothelial function, or arterial stiffness. In a placebo-controlled, randomized clinical trial, we measured blood pressure, brachial artery endothelium-dependent vasodilation, and common carotid artery stiffness in 158 clinically healthy siblings of patients with premature atherothrombotic disease at baseline and after 1 and 2 years of homocysteine-lowering treatment with folic acid (5 mg) plus pyridoxine (250 mg). Intention-to-treat analyses limited to participants (n=130) who underwent at least 1 measurement after the baseline visit showed that compared with placebo, treatment with folic acid plus pyridoxine was associated with a 3.7-mm Hg (95% CI -6.8 to -0.6 mm Hg) lower systolic and a 1.9-mm Hg (95% CI -3.7 to -0.02 mm Hg) lower diastolic blood pressure over the 2-year trial period. Together with the decreased occurrence of abnormal exercise electrocardiography tests reported previously, our results support the hypothesis that homocysteine-lowering treatment with folic acid plus pyridoxine has beneficial vascular effects. Because no effects could be demonstrated on brachial artery endothelium-dependent vasodilation or on common carotid artery stiffness, the present study does not support the hypothesis that the cardiovascular effects of homocysteine are mediated through these factors, at least in clinically healthy individuals.

Adult↗
PubMed2001

Continuing expansion of internal iliac artery aneurysms after surgical exclusion of the inflow. A report of two cases.

Two patients with continuing expansion of an internal iliac artery aneurysm following earlier repair of an aortoiliac aneurysm are described. At the primary operation, inflow to small internal iliac aneurysms had been interrupted by simple proximal ligation only. During follow-up, however, increasing diameter of the by CT-angiography completely thrombosed internal iliac aneurysms required re-operation. The observation of continuing growth of thrombosed internal iliac artery aneurysms following proximal ligation emphasises the danger of persistent collateral circulation and supports the concept of endotension in the absence of endoleak following endovascular AAA repair.

Aged↗
PubMed2000

[Thoracoscopic clipping of thoracic duct in a woman with persisting chylothorax].

A 78-year-old female had chest pain, radiating to the back, caused by a thoracic aneurysm of the aorta. A vascular prosthesis was sutured into place through a left-sided thoracotomy. Six days after the operation she developed chylothorax on the right side. Following 14 days of conservative management, chyle leakage persisted at a rate of 1500 ml per 24 hours. By thoracoscopy the thoracic duct was dissected and clipped, which stopped the chyle leakage. The patient recovered moderately well. Conservative measures, such as adjusted nutrition, are successful in 50% of patients. Clipping of the thoracic duct by thoracoscopy is a definitive and minimally invasive procedure to treat persistent chyle leakage.

Aged↗
PubMed2000

[Radiation-induced arterial disease].

Arterial occlusive disease developed after radiation therapy in three patients: a woman aged 56 had a sensation of heaviness in her right arm and bluish-black discolorations of fingers 3 years after radiation therapy for breast carcinoma, and two men aged 46 and 45 years had intermittent claudication 23 and 14 years, respectively, after radiation therapy for testicle malignancy. After creation of a bypass, the symptoms subsided. Radiation-induced arterial disease is a rare complication after radiotherapy and usually presents after a latent period of several years. Arterial lesions induced by radiotherapy may be distinguished from atherosclerotic lesions by their atypical localization, limited to the irradiated sites, and occurrence at an earlier age. Symptoms may be masked by pain, limitation of motion, nerve root damage and lymphoedema and may therefore not always be recognized. Indications for treatment are identical to those for atherosclerotic occlusive disease, but due to increased risk of restenosis, rethrombosis and graft infection, percutaneous transluminal angioplasty (with or without stent), endarterectomy or venous bypass surgery should be preferred to prosthetic bypass material.

Arterial Occlusive Diseases↗
PubMed2000

Effect of homocysteine-lowering treatment with folic acid plus vitamin B6 on progression of subclinical atherosclerosis: a randomised, placebo-controlled trial.

BACKGROUND: A high plasma homocysteine concentration is associated with increased risk of atherothrombotic disease. We investigated the effects of homocysteine-lowering treatment (folic acid plus vitamin B6) on markers of subclinical atherosclerosis among healthy siblings of patients with premature atherothrombotic disease. METHODS: We did a randomised, placebo-controlled trial among 158 healthy siblings of 167 patients with premature atherothrombotic disease. 80 were assigned placebo and 78 were assigned 5 mg folic acid and 250 mg vitamin B6 daily for 2 years. The primary endpoint was the development or progression of subclinical atherosclerosis as estimated from exercise electrocardiography, the ankle-brachial pressure index, and carotid and femoral ultrasonography. FINDINGS: Ten participants in the treatment group, and 14 in the placebo group dropped out. Vitamin treatment, compared with placebo, was associated with a decrease in fasting homocysteine concentration (from 14.7 to 7.4 micromol/L vs from 14.7 to 12.0 micromol/L), and in postmethionine homocysteine concentration (from 64.9 to 34.9 micromol/L vs from 64.8 to 50.3 micromol/L). It was also associated with a decreased rate of abnormal exercise electrocardiography tests (odds ratio 0.40 [0.17-0.93]; p=0.035). There was no apparent effect of vitamin treatment on ankle-brachial pressure indices (0.87 [0.56-1.33]), or on carotid and peripheral-arterial outcome variables (1.02 [0.26-4.05] and 0.86 [0.47-1.59], respectively). INTERPRETATION: Homocysteine-lowering treatment with folic acid plus vitamin B6 in healthy siblings of patients with premature atherothrombotic disease is associated with a decreased occurrence of abnormal exercise electrocardiography tests, which is consistent with a decreased risk of atherosclerotic coronary events.

Blood Pressure↗
PubMed2000

A 6-year-old boy with hyperammonaemia: partial N-acetylglutamate synthase deficiency or portosystemic encephalopathy?

UNLABELLED: We describe a 6-year-old boy admitted with lethargy and somnolence. Laboratory tests showed hyperammonaemia (arterial level 186 micromol/l) and slightly elevated prothrombin time. The patient was treated with sodium benzoate, lactulose and a protein-restricted diet. This resulted in an insufficient decrease in blood ammonia levels. Metabolic investigations were unrevealing apart from a slightly elevated urinary glutamine concentration. Liver tissue showed steatosis and mildly decreased activity of N-acetylglutamate synthase suggesting partial deficiency. Treatment with N-carbamyl glutamate did not affect serum ammonia levels. Colour Doppler sonography and MR angiography demonstrated a patent ductus venosus. After surgical ligation of the ductus venosus, serum ammonia levels returned to normal and mental and motor performance improved markedly. CONCLUSION: In late onset hyperammonaemia, partial N-acetylglutamate synthase deficiency and portocaval shunt should be ruled out.

Acetyltransferases↗
PubMed2000

Normohomocysteinaemia and vitamin-treated hyperhomocysteinaemia are associated with similar risks of cardiovascular events in patients with premature atherothrombotic cerebrovascular disease. A prospective cohort study.

BACKGROUND: Mild hyperhomocysteinaemia (HHC) is associated with an increased risk of premature atherothrombotic cerebrovascular disease. We investigated the clinical efficacy with regard to the incidence of cardiovascular events of treatment of mild HHC with vitamin B(6) plus folic acid. METHODS: We studied 224 consecutive patients with clinically manifest atherothrombotic cerebrovascular disease with onset before the age of 56. Follow-up was obtained in 203 (90.6%) patients. At baseline, 52 (25.6%) were hyperhomocysteinaemic after methionine loading and started treatment with vitamin B(6) (250 mg) plus folic acid (5 mg); 151 (74.4%) were normohomocysteinaemic (reference group). RESULTS: During follow-up (median 57 months), 31 (20.5%) of the normo- and 11 (21.2%) of the hyperhomocysteinaemic patients had a new cardiovascular event. The crude incidence rate per person-year for any cardiovascular event was similar in both groups (0.043 [CI, 0.029-0.057] in the normo- vs. 0.045 [CI, 0.021-0. 069] in the hyperhomocysteinaemic group). Multivariate Cox-regression analyses showed that hypertension and cholesterol levels were associated with an increased risk of new cardiovascular events in the total group [relative risk [RR] (yes vs. no), 7.4 (3. 4-16.0) and RR (per 1 mmol/l), 1.9 (CI, 1.4-2.7)]. The adjusted RR for new cardiovascular events in the hyper- as compared to the normohomocysteinaemic patients was 0.96 (CI, 0.48-1.92). CONCLUSION: These data are consistent with a protective effect of treatment with vitamin B(6) plus folic acid in patients with premature atherothrombotic cerebrovascular disease and post-methionine HHC.

Adult↗
PubMed2000

Low arginine plasma levels in patients after thoracoabdominal aortic surgery.

OBJECTIVE: Thoracoabdominal aortic surgery is a high-risk procedure and associated with a significant morbidity and mortality. Ischemia reperfusion of visceral organs and lower extremities is one of the most important determinants of this morbidity. Arginine is the precursor of nitric oxide and arginine plasma levels are important in maintaining organ blood flow. Furthermore, arginine is important in wound healing and the immune system. Because of increased utilization of arginine, low arginine plasma levels could be expected after thoracoabdominal aortic surgery. We therefore measured arginine plasma levels in these patients. DESIGN: Six patients with thoracoabdominal aortic aneurysm were included in this study. SETTING: University Hospital Vrije Universiteit, Department of Surgery, Amsterdam, The Netherlands. SUBJECTS: Six patients undergoing thoracoabdominal aortic surgery. INTERVENTION: Plasma levels of arginine were measured by high-performance liquid chromatography. RESULTS: Very low arginine plasma levels were seen on the first postoperative day. From day 1 arginine slowly increased, but did not reach normal plasma levels on day 6. CONCLUSIONS: A significant decrease of arginine plasma levels was found and because of the fact that arginine has multiple functions, it may be important to keep these arginine plasma levels at normal or even higher levels in patients undergoing major vascular surgery. European Journal of Clinical Nutrition (2000) 54, 615-617.

Aged↗