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Biomedical subjects

L van der Laan

Publications and source records attributed to L van der Laan.

At least 19 recordsLinked to original sources
PubMed2005

[Retroperitoneal haematoma seen on CT scan in 2 patients with abdominal symptoms, aneurysm of the abdominal aorta and normal haemodynamics].

In 2 patients, men aged 73 and 66 undergoing physical and ultrasound examinations for complaints of abdominal pain, an aneurysm of the abdominal aorta (AAA) with a diameter of 7-8 cm was discovered. Both their blood pressure and heart rate were normal. The older man then underwent a CT scan as did the younger man after being observed overnight. They both proved to have a ruptured AAA. They were operated on and recovered well. It can be problematic to diagnose a ruptured AAA quickly in patients with abdominal and back pain, AAA on ultrasound and normal haemodynamic parameters. In this situation an emergency CT scan will visualize any retroperitoneal haematoma and the patient can undergo an emergency operation. If the CT scan does not show any rupture there is time for preoperative preparations before performing a semi-elective procedure.

Abdominal Pain↗
PubMed2004

[The central-venous compression syndrome: rare, but adequately treatable with endovascular stenting].

Two patients, women aged 30 and 29, had severe chronic pain in the left leg, and a woman aged 36 had pain in the left flank. On the grounds of the clinical symptoms, phlebography and venous-duplex ultrasonography, a central-venous compression syndrome was diagnosed: compression of the left common iliac vein between the crossing right common iliac artery and the body of the fifth lumbar vertebra (May-Thurner syndrome). The patient with left flank pain also had haematuria. Angiography, computed tomography and phlebography revealed that these symptoms were due to compression of the left renal vein between the abdominal aorta and the superior mesenteric artery (nutcracker phenomenon). The treatment of all 3 patients consisted of venous endovascular stenting. At follow-up after 12, 30 and 15 months, respectively, the complaints had subsided considerably.

Adult↗
PubMed2000

Leg muscle reflexes mediated by cutaneous A-beta fibres are normal during gait in reflex sympathetic dystrophy.

OBJECTIVES: Reflex sympathetic dystrophy (RSD) is, from the onset, characterized by various neurological deficits such as an alteration of sensation and a decrease in muscle strength. We investigated if afferent A-beta fibre-mediated reflexes are changed in lower extremities affected by acute RSD. METHODS: The involvement of these fibres was determined by analyzing reflex responses from the tibialis anterior (TA) and biceps femoris (BF) muscles after electrical stimulation of the sural nerve. The reflexes were studied during walking on a treadmill to investigate whether the abnormalities in gait of the patients were related either to abnormal amplitudes or deficient phase-dependent modulation of reflexes. In 5 patients with acute RSD of the leg and 5 healthy volunteers these reflex responses were determined during the early and late swing phase of the step cycle. RESULTS: No significant difference was found between the RSD and the volunteers. During early swing the mean amplitude of the facilitatory P2 responses in BF and TA increased as a function of stimulus intensity (1.5, 2 and 2.5 times the perception threshold) in both groups. At end swing the same stimuli induced suppressive responses in TA. This phase-dependent reflex reversal from facilitation in early swing to suppression in late swing occurred equally in both groups. CONCLUSIONS: In the acute phase of RSD of the lower extremity there is no evidence for abnormal A-beta fibre-mediated reflexes or for defective regulation of such reflexes. This finding has implications for both the theory on RSD pathophysiology and RSD models, which are based on abnormal functioning of A-beta fibres.

Adult↗
PubMed2000

Adjuvant physical therapy versus occupational therapy in patients with reflex sympathetic dystrophy/complex regional pain syndrome type I.

OBJECTIVE: To investigate the effectiveness and cost of physical therapy (PT) or occupational therapy (OT) in patients with reflex sympathetic dystrophy (RSD). DESIGN: Prospective randomized controlled trial, with 1 year follow-up. SETTING: Two university hospitals. PATIENTS: One hundred thirty-five patients who had been suffering from RSD of one upper extremity for less than 1 year. INTERVENTIONS: Patients were assigned to PT, OT, or a control group (social work). MAIN OUTCOME MEASURES: Improvement in impairment level sumscore (ISS) over 1 year (Student's t test). A difference of 5 ISS points between the groups was defined as being clinically relevant. Furthermore, severity of disability and handicap was measured and tested exploratively (Wilcoxon; alpha = .05), and cost-effectiveness of the groups was calculated. RESULTS: PT and, to a lesser extent, OT resulted in a significant and also more rapid improvement in the ISS as compared with controls (6 and 4 ISS points, respectively). On a disability level, a positive trend was found in favor of OT. On a handicap level, no differences were found between the groups. PT had an advantage over OT regarding the cost-effectiveness ratio. CONCLUSION: In different ways PT and OT each contribute to the recovery from RSD of the upper extremity.

Female↗
PubMed1999

A comparison of free radical-induced vascular and skeletal muscle damage in immunocompetent and neutropenic rats.

BACKGROUND: Intraarterial infusion of the free radical donor tert. -butyl-hydroperoxide (tert.-BuOOH) into one extremity of the rat induces vascular permeability and considerable skeletal muscle damage. However, it remains unclear what the role of polymorphonuclear neutrophils (PMNs) is in oxidative stress-related processes. Therefore, we investigated possible differences between neutropenic and normal animals in this model. METHODS: Neutropenia was induced in male rats by intraperitoneal administration of cyclophosphamide. tert.-BuOOH was continuously infused intraarterially into one hindlimb of normal or neutropenic nonanesthetized rats for 24 h. The control neutropenic rats were infused with the same volume of saline. After the infusion, 99mTc-IgG was administered intravenously followed by scintigraphic imaging analysis of the left/right uptake ratio of the hindlimbs and by gamma counting of the tissue samples of the gastrocnemius and gluteus maximus muscles. Samples of these muscles were analyzed by light microscopy. RESULTS: The uptake ratios were significantly increased in the normal and neutropenic tert.-BuOOH-infused animals as compared with the saline-infused neutropenic rats (P < 0.05). The uptake ratios were significantly higher in normal than in neutropenic tert.-BuOOH-infused rats (P < 0.05). Histological analysis of the saline infused skeletal muscles showed unaffected skeletal muscles with intact arterioles and arteries. In the gastrocnemius and gluteus maximus muscles of the normal tert. -BuOOH-infused and neutropenic rats, similar morphological damage was observed. CONCLUSIONS: PMNs can increase, to some extent, the vascular permeability of the free radical damaged small arteries and arterioles of a tert.-BuOOH-infused hindlimb. However, in the present animal model, tert.-BuOOH alone can induce oxidative stress-related abnormalities with skeletal muscle tissue damage that is mainly independent of the presence of PMNs.

Animals↗
PubMed1999

The Symptom Checklist-90 Revised questionnaire: no psychological profiles in complex regional pain syndrome-dystonia.

Complex regional pain syndrome (CRPS) is a syndrome usually localized in the extremities, mostly occurring after a preceding trauma or operation. Dystonia is present in a minority of CRPS patients, but, when present, leads to severe disability. Various pathological factors have been postulated to present in CRPS-dystonia, such as involvement of the sympathetic system, reorganization of the central nervous system, and psychological distress. In the present study, we investigated the involvement of psychological distress in CRPS-dystonia with the aid of the Symptom Checklist-90 Revised (SCL-90R) questionnaire. The SCL-90R is a multidimensional self-report inventory covering various dimensions of psychological distress. In a population of 1006 CRPS patients, we analyzed the SCL-90R scores of 27 patients with CRPS-dystonia (23 female and 4 male) and compared the scores to sample scores of a control female (n = 577) and a control rehabilitation population (n = 56). Insomnia scored significantly higher in the female CRPS-dystonia population, as compared to the control female population (P < 0.001), and in the total CRPS-dystonia population, as compared to the rehabilitation population (P < 0.01). Remarkable was the significantly higher score of somatization in the rehabilitation population, as compared to the CRPS-dystonia population (P = 0.006). For the other dimensions of psychological distress of the SCL-90R, the scores of the CRPS-dystonia and control populations were similar. With regard to the SCL-90R scores, we conclude that specific psychological profiles are not present in CRPS-dystonia.

Adolescent↗
PubMed1998

NADH videofluorimetry to monitor the energy state of skeletal muscle in vivo.

BACKGROUND: Reduction of the cellular energy state during ischemia of the limbs is an important determinant for development of necrosis. Since energy conversion in the mitochondria is based on electron transport from NADH to molecular O2, the NADH/NAD+ redox couple reflects the mitochondrial redox state and cellular O2 requirement. The applicability of NADH videofluorimetry to monitor noninvasively changes in the energy state of intact resting skeletal muscle as a function of oxygenation was investigated in a rat model. MATERIALS AND METHODS: In mechanically ventilated rats (n = 6), NADH fluorescence images of the gracilis muscle were recorded under different oxygenation conditions. Induction of anoxic and ischemic hypoxia were verified by simultaneous measurement of tissue oxygen pressure and afferent blood flow. RESULTS: Anoxic hypoxia and ischemic hypoxia increased the NADH fluorescence intensity by 46.0 +/- 15.0 and 30.8 +/- 26.4%, respectively. The response time of NADH fluorescence intensity, tissue oxygen pressure, and afferent blood flow was similar during development of anoxic and ischemic hypoxia. Upon reperfusion and reoxygenation, however, NADH fluorescence intensity changed significantly earlier than tissue oxygen pressure as measured by an oxygen needle electrode. CONCLUSION: These results demonstrate that changes in NADH fluorescence intensity reflect oxygenation changes in intact skeletal muscle in vivo. Since NADH videofluorimetry, in contrast to oxygen needle electrode measurements, noninvasively visualizes temporal and regional changes in the energy state of skeletal muscle, this technique has the potential to improve clinical evaluation of ischemia/reperfusion injury and tissue viability.

Animals↗
PubMed1998

Severe complications of reflex sympathetic dystrophy: infection, ulcers, chronic edema, dystonia, and myoclonus.

OBJECTIVE: To determine the prevalence, type of complication, predisposing factors, and treatment for severe complications in a population of reflex sympathetic dystrophy (RSD) patients. DESIGN: Retrospective analysis of the data from RSD patients collected over a 12-year period, to investigate the involvement of predisposing factors in an RSD population without severe complications compared with an RSD population with severe complications. SETTING: Outpatient clinic of a department of surgery of a university hospital. PATIENTS: A total of 1,006 patients with the diagnosis of RSD established according to prospectively defined criteria. MAIN OUTCOME MEASURES: The signs and symptoms of every RSD patient who visited the department were prospectively documented in the medical history; these data were retrospectively analyzed with special regard to RSD with severe complications-infection, ulcers, chronic edema, dystonia, and/or myoclonus-for prevalence, type of complication, and treatment. RESULTS: Seventy-four RSD patients who were mostly young and female developed severe complications. More than one complication occurred in 91% of the affected extremities. Severe complications developed more frequently in the lower extremity (65%). In patients in whom the acute RSD started with a decreased skin temperature of the affected extremity, severe complications developed significantly more often than in acute RSD patients with a warm skin temperature of the extremity from the onset of the disease (p < .001). CONCLUSIONS: It is important to recognize "cold" RSD immediately at the onset of the disease because this group of RSD patients has a higher risk of developing a severe complication, mostly followed by a severe disability that is resistant to therapy.

Adolescent↗
PubMed1998

Complex regional pain syndrome type I (RSD): pathology of skeletal muscle and peripheral nerve.

BACKGROUND: Reflex sympathetic dystrophy (RSD) (recently reclassified as complex regional pain syndrome type I) is a syndrome occurring in extremities and, when chronic, results in severe disability and untractable pain. RSD may be accompanied by neurologic symptoms even when there is no previous neurologic lesion. There is no consensus as to the pathogenic mechanism involved in RSD. To gain insight into the pathophysiology of RSD, we studied histopathology of skeletal muscle and peripheral nerve from patients with chronic RSD in a lower extremity. METHODS: In eight patients with chronic RSD, an above-the-knee amputation was performed because of a nonfunctional limb. Specimens of sural nerves, tibial nerves, common peroneal nerves, gastrocnemius muscles, and soleus muscles were obtained from the amputated legs and analyzed by light and electron microscopy. RESULTS: In all patients, the affected leg showed similar neurologic symptoms such as spontaneous pain, hyperpathy, allodynia, paresis, and anesthesia dolorosa. The nerves showed no consistent abnormalities of myelinated fibers. In four patients, the C-fibers showed electron microscopic pathology. In all patients, the gastrocnemius and soleus muscle specimens showed a decrease of type I fibers, an increase of lipofuscin pigment, atrophic fibers, and severely thickened basal membrane layers of the capillaries. CONCLUSION: In chronic RSD, efferent nerve fibers were histologically unaffected; from afferent fibers, only C-fibers showed histopathologic abnormalities. Skeletal muscle showed a variety of histopathologic findings, which are similar to the histologic abnormalities found in muscles of patients with diabetes.

Adult↗
PubMed1998

Clinical signs and symptoms of acute reflex sympathetic dystrophy in one hindlimb of the rat, induced by infusion of a free-radical donor.

The acute phase of reflex sympathetic dystrophy (RSD) is characterized by the classical signs and symptoms of inflammation (rubor, calor, dolor, tumor and impaired function). As free radicals are involved in acute inflammation, we studied the effects of free radicals in an animal model, especially as to signs and symptoms found in acute RSD. Awake rats were given continuous intra-arterial infusion (1 ml/h) in the left hindlimb, with saline (n = 6) or the free-radical donor tert-butylhydroperoxide (tert-BuOOH, 25 mM, n = 6). During a 24-h infusion period the skin temperature, volume, skin color, function and pain reactions of the paws were observed. After 24 h the rats were killed and both gastrocnemius muscles were histologically analyzed. Infusion with tert-BuOOH induced in the left paw an increased skin temperature, increased volume, redness of the plantar skin, impaired function and increased pain sensation, while these acute RSD signs and symptoms were absent in the saline infused animals. The alterations in pain sensation (spontaneous, mechanical and thermal pain) were similar to findings in the neuropathic animal model. The gastrocnemius muscles of the saline infused rats and the contralateral gastrocnemius muscle of the tert-BuOOH infused rats showed no histological tissue damage. In the left gastrocnemius muscle free-radical-related damage was visible. Induction of free-radical formation in one hindlimb of awake rats mimics the acute signs and symptoms of acute RSD, with alterations in pain sensation as found in the classical neuropathic animal model of RSD, as well as in acute RSD patients.

Acute Disease↗
PubMed1997

Soft tissue repair capacity after oxygen-derived free radical-induced damage in one hindlimb of the rat.

Oxygen-derived free radicals are suspected to play an important role in the pathogenesis of inflammation and ischemia/reperfusion of an extremity. In this study we investigated the repair capacity of a free radical-damaged hindlimb of the rat and the effect of the anti-oxidant N-acetyl-L-cysteine (NAC). In nonanesthetized rats (n = 39), the left hindlimb was continuously infused intra-arterially (1 ml/hr) for 24 hr with the free radical donor tert-butylhydroperoxide (tert-BuOOH, 25 mM). Subsequently the infusion system was disconnected and the repair of soft tissue damage was observed with special attention to various pain tests, vascular permeability ((99m)Tc-IgG scintigraphy), and histology for a maximum period of 6 weeks. In 12 of these tert-BuOOH-infused rats the antioxidant NAC was injected intraperitoneally. Six of the NAC-treated rats were killed after 24 hr of infusion, while the remaining 6 rats were disconnected, reinjected with NAC, and observed for 1 week. Tert-BuOOH infusion for 24 hr led to significantly increased pain sensations, vascular permeability, and histological damage. Treatment with NAC significantly reduced pain sensations and vascular permeability, though not to control levels. One week after disconnection, tissue damage was almost completely repaired in the NAC-treated rats. In the untreated rats, repair took longer but histology and vascular permeability were completely normalized within the observation period. Soft tissue damage, induced by 24-hr infusion of the free radical donor tert-BuOOH, showed spontaneous repair within 6 weeks. The antioxidant NAC significantly reduced the soft tissue damage and shortened the repair period.

Acetylcysteine↗
PubMed1997

[Sudeck's syndrome. Was Sudeck right?].

Reflex sympathetic dystrophy (RSD) is a syndrome affecting an extremity after a minor trauma or operation. At the moment there is no consensus about the pathogenesis of RSD. In 1942 Paul Sudeck suggested that the signs and symptoms of RSD may be provoked by an exaggerated inflammatory response to injury or operation of an extremity. His theory found no disciples, as most physicians believe that RSD is initiated by an hyperactive sympathetic system. We performed various clinical and experimental investigations, including the effects of antiinflammatory treatment. The results of these studies support the theory of Paul Sudeck.

Animals↗
PubMed1997

A novel animal model to evaluate oxygen derived free radical damage in soft tissue.

We present a novel animal model which allows the continuous intra-arterial infusion in one hindlimb of non-anaesthetized rats, without inducing ischemia. Using this model the effect of continuous infusion (1 ml/h) for 24 h with tert-butylhydroperoxide (tert-BuOOH) at a concentration of 25 mM on soft tissue of the left hind limb was studied and compared to the effect of saline infusion (control group). The tert-BuOOH-infused foot showed increased skin temperature, increased circumference, redness of the plantar skin, impaired function and increased pain sensation, while in the contralateral foot and in rats only perfused with saline these signs of inflammation were absent (p < 0.01). Histological analysis of the left gastrocnemius muscle showed edema, muscle cell degeneration with a patchy distribution pattern and vascular damage. All these features increased in severity from 4 to 24 h tert-BuOOH infusion. After 24 h of tert-BuOOH infusion infiltration of neutrophils in the interstitium was observed. Vascular permeability, expressed as left to right gastrocnemius muscle 99mTc-IgG uptake ratio, was similarly increased after 4 h (2.09 +/- 0.26) and 12 h (2.04 +/- 0.08) of tert-BuOOH infusion compared to saline (1.05 +/- 0.08) (p < 0.001), and further increased after 24 h (3.84 +/- 0.13): (p < 0.001). In this animal model free radical-related soft tissue damage was induced, by continuous infusion of tert-BuOOH, followed by increasing necrosis and vascular permeability in skeletal muscle coinciding with neutrophilic infiltration.

Animals↗
PubMed1997

Reflex sympathetic dystrophy. An exaggerated regional inflammatory response?

Reflex sympathetic dystrophy (RSD) is a syndrome affecting an extremity after a minor trauma or operation. Currently, there is no consensus about the pathogenesis of RSD. The authors performed various clinical and experimental investigations, including studies of the effects of anti-inflammatory treatment, that support the hypothesis that RSD is the result of an exaggerated inflammatory response to injury or surgery.

Animals↗
PubMed1996

Reflex sympathetic dystrophy after a burn injury.

Reflex sympathetic dystrophy (RSD) is a disease that can appear after minor trauma or operation to an extremity. The injury may vary from a simple contusion to a fracture. The prevalence of burns as a cause of RSD, within a population of 829 patients with RSD, was studied retrospectively. Prospectively, we documented the medical history, signs and symptoms of all patients with RSD, seen by our department during the period from January 1984 to 31 December 1994. Four patients had developed RSD after a burn injury, resulting in a prevalence of 0.5 per cent. Though the clinical signs of early RSD are similar to those of a (thermal) burn, alertness to recognize inflammatory signs, in combination with the increase in complaints after exercise, is necessary for early diagnosis and treatment of the complicating RSD.

Adult↗