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Biomedical subjects

A Peeters

Publications and source records attributed to A Peeters.

At least 37 records · Page 2Linked to original sources

A model for predicting the future incidence of coronary heart disease within percentiles of coronary heart disease risk.

BACKGROUND: We present a method (The CHD Prevention Model) for modelling the incidence of fatal and nonfatal coronary heart disease (CHD) within various CHD risk percentiles of an adult population. The model provides a relatively simple tool for lifetime risk prediction for subgroups within a population. It allows an estimation of the absolute primary CHD risk in different populations and will help identify subgroups of the adult population where primary CHD prevention is most appropriate and cost-effective. METHODS: The CHD risk distribution within the Australian population was modelled, based on the prevalence of CHD risk, individual estimates of integrated CHD risk, and current CHD mortality rates. Predicted incidence of first fatal and nonfatal myocardial infarction within CHD risk strata of the Australian population was determined. RESULTS: Approximately 25% of CHD deaths were predicted to occur amongst those in the top 10 percentiles of integrated CHD risk, regardless of age group or gender. It was found that while all causes survival did not differ markedly between percentiles of CHD risk before the ages of around 50-60, event-free survival began visibly to differ about 5 years earlier. CONCLUSIONS: The CHD Prevention Model provides a means of predicting future CHD incidence amongst various strata of integrated CHD risk within an adult population. It has significant application both in individual risk counselling and in the identification of subgroups of the population where drug therapy to reduce CHD risk is most cost-effective.

Actuarial Analysis↗

Selective involvement of the choroid plexus on cerebral magnetic resonance images: a new radiological sign in patients with systemic lupus erythematosus with neurological symptoms.

The selective involvement of the choroid plexus on brain magnetic resonance (MR) images is described in 2 patients with systemic lupus erythematosus presenting with neurological symptoms. The decrease in choroid plexus abnormalities on followup MR examination paralleled the clinical recovery with glucocorticoid therapy in both patients. Our cases indicate that selective involvement of the choroid plexus should be included in the spectrum of the radiological signs for neurological lupus.

Adult↗

Oncocytic laryngeal cysts: a case report and literature review.

Some 150 cases of oncocytic laryngeal cysts have been published. We report another case of laryngeal oncocytic cysts with atypical presentation of acute, progressive stridor and sore throat. Literature was reviewed with special regard to etiology, clinical presentation, imaging, incidence, localization, associated lesions and treatment options. Oncocytic laryngeal cysts are rare, but may be underreported. They represent a separate clinicopathological entity in the group of all laryngeal cysic lesions and occur in persons over 60 years. The symptomatology varies from asymptomatic to hoarseness and dyspnea. Diagnosis is made by histological examination. Treatment is surgical. Although it is a benign lesion, follow up is recommended, as recurrence is possible.

Acute Disease↗

Lethal complications after tonsillectomy.

Lethal complications after tonsillectomy. Two cases of serious complications after paediatric tonsillectomy, that were referred to our department, resulted in death, one due to massive haemorrhage and one due to hyponatremia. Thanks to early recognition and adequate treatment, two other cases could be successfully treated. The literature on serious complications after tonsillectomy was critically reviewed. Guidelines on peri- and postoperative fluid management are given. Vascular anatomy of the tonsillar region is reviewed. Location and treatment policy on severe haemorrhages are discussed.

Child↗

Automatic external defibrillators: changing the way we manage ventricular fibrillation.

OBJECTIVE: To discuss recent developments in automatic defibrillation and to review the evidence that first-responders equipped with automatic external defibrillators (AEDs) improve survival from out-of-hospital cardiac arrest. DATA SOURCES: MEDLINE search from 1966 to 1999 (articles in English only) and examination of bibliographies. STUDY SELECTION: Published studies of out-of-hospital cardiac arrest and first-responders equipped with AEDs. Studies had to have a control group and to report survival to hospital discharge from ventricular fibrillation (VF). DATA EXTRACTION: Six studies met the selection criteria (two prospective randomised trials, two prospective controlled trials, and one cohort study and one retrospective study, both with historical controls). DATA SYNTHESIS: A random effects meta-analysis of odds ratios for survival from VF. CONCLUSIONS: Meta-analysis suggests that equipping first-responders with AEDs increases the probability of survival to hospital discharge after out-of-hospital cardiac arrest (odds ratio, 1.74; 95% CI, 1.27-2.38; P < 0.001). However, most of the studies lacked sufficient power to draw definitive conclusions. Until the impact of wide deployment of AEDs is fully understood, first-responder defibrillation in Australia should only occur as part of coordinated multicentre research studies.

Australia↗

Simultaneous attainment of high electron and ion temperatures in discharges with internal transport barriers in ASDEX upgrade

Internal transport barriers have been demonstrated to exist also under conditions with T(e) approximately T(i) approximately 10 keV and predominant electron heating of the tokamak core region. Central electron cyclotron heating was added to neutral beam injection-heated ASDEX Upgrade discharges with a preexisting internal transport barrier, established through programmed current ramping leading to shear reversal. Compared to a reference internal transport barrier discharge without electron cyclotron resonance heating, the electron heat conductivity in the barrier region was found not to increase, in spite of a fivefold increase in electron heat flux, and also angular momentum and ion energy transport did not deteriorate.

Journal Article↗

A compilation of cellular transcription factor interactions with the HIV-1 LTR promoter.

The human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) represents a model promoter system and the identification and characterisation of cellular proteins that interact with this region has provided a basic understanding about both general eukaryotic and HIV-1 proviral transcriptional regulation. To date a large number of sequence-specific DNA-protein interactions have been described for the HIV-1 LTR. The aim of this report is to provide a comprehensive, updated listing of these HIV-1 LTR interactions. It is intended as a reference point to facilitate on-going studies characterising the identity of cellular proteins interacting with the HIV-1 LTR and the functional role(s) of specific regions of the LTR for HIV-1 replication.

DNA-Binding Proteins↗

High signal in cerebrospinal fluid mimicking subarachnoid haemorrhage on FLAIR following acute stroke and intravenous contrast medium.

We describe five cases of high signal in the cerebrospinal fluid (CSF) on fast-FLAIR images 24-48 h after onset of stroke. All the patients had undergone perfusion-weighted MRI within 6 h of the onset of the symptoms. The CSF was far brighter than the cortical gyri. The high signal was diffusely around both cerebral hemispheres in two cases and around one hemisphere in two others; it was focal, around the acute ischaemic lesion, in one. CT was normal in all cases. The CSF high signal was transient, decreasing in extent and intensity with time and resolving completely within 3-6 days. It was not associated with worsening of the clinical state or poor outcome. Our explanation of this phenomena is hypothetical: we speculate that it could be due to disruption of the blood-brain barrier resulting in leakage of protein, gadolinium chelates, or both in to the subarachnoid space. It should not be confused with subarachnoid haemorrhage.

Aged↗

The potential and limitations of transcranial Doppler in clinical practice.

The aim of this review is to bring the clinical relevance of transcranial Doppler (TCD) to light with all of its possibilities and limitations. Indeed, TCD, a non-invasive ultrasound technique, allows instantaneous evaluation of the cerebral blood flow, adding physiological information to the anatomical images. Although TCD is frequently used in some places, in other regions TCD remains relatively unknown. However, TCD can help the neurologist not only in the management of cerebrovascular disease, but also in a wide variety of central nervous system disorders. TCD monitoring with multichannel and multigate probes can assess vascular reactivity by following various parameters, such as CO2 or arterial blood pressure. Despite the need for more work, emboli detection seems to offer great potential in the future diagnosis, treatment, and prevention of stroke.

Humans↗

[Degree of hemodynamic disturbance at the hyperacute phase of stroke: predictive value of 3D-TOF angiography and the T2 fast-FLAIR sequence].

GOAL: To define during the hyperacute phase of stroke the value of 3D-TOF MR angiography (MRA) and T2 fast-FLAIR sequence for predicting the volume of tissue presenting a hemodynamic disturbance. MATERIAL: and method: Thirty-five cases of hyperacute stroke located in following territories: middle cerebral artery (MCA) (n=29), anterior choroidal artery (AChoA) (n=5) and watershed (n=1) were retrospectively reviewed. The vascular abnormalities defined on MRA (vessel stenosis or occlusion) or FLAIR sequence (vessel hyperintensity) were classified into 3 groups: normal (I), distal abnormalities (II), abnormalities of the entire arterial territory (III). These results were compared with the volume of tissue showing a prolonged mean transit time (MTT) determined on relative MTT maps calculated from bolus tracking MR perfusion images. RESULTS: The abnormal volume measured on the MTT map was significantly correlated to the results of the MRA and FLAIR sequence. In the 12 cases of group III defined on the MRA (abnormality from M1), the volume of hemodynamic disturbance was always higher than 100 ml. For the MCA territory, it was not possible to predict the presence of a hemodynamic disturbance in any of the 3 groups defined on the FLAIR sequence and in the groups I and II defined on the MRA. For the AChoA territory, a hemodynamic disturbance was never observed in groups I and II defined either on MRA or FLAIR sequence. CONCLUSION: When there was no flow within the M1 segment on the MRA, there was always a hemodynamic disturbance larger than 100 ml on the MTT map. In the case of AChoA ischemic lesion, when no vascular abnormality was observed on the MRA or FLAIR images, the MTT map was always normal.

Acute Disease↗

Resolution of early diffusion-weighted and FLAIR MRI abnormalities in a patient with TIA.

We report a patient with a clinical history and neurologic examination consistent with acute stroke. Diffusion-weighted and fast fluid-attenuated inversion recovery MRI obtained 4 hours after stroke onset detected focal abnormalities suggestive of acute ischemic brain damage. The neurologic deficit and the imaging abnormalities both resolved completely at follow-up. This patient illustrates complete resolution of early changes observed with diffusion-weighted MRI at the hyperacute phase in a TIA.

Aged↗

Ab initio study of the reaction mechanism of ribonuclease A with cytidyl-3',5'-adenosine. I. Geometry optimization of cytidyl-3', 5'-adenosine.

As a first part of the ab initio study of the reaction mechanism of ribonuclease A with cytidyl-3',5'-adenosine, the geometry of the cytidyl-3',5'-adenosine substrate has been optimized using the Hartree-Fock method. Eleven different starting structures of cytidyl-3',5'-adenosine have been studied. To guarantee a proper alignment with the active site of the ribonuclease A enzyme, a part of the substrate was fixed during the geometry optimization. The geometry and intramolecular interactions of the refined conformations have been evaluated and two possible prototype structures have been proposed. One of these prototypes is more in accordance with the results of a molecular dynamics simulation and is therefore presented as a model for the geometry of cytidyl-3', 5'-adenosine in the initial step of the reaction with ribonuclease A.

Adenosine↗

Fast FLAIR sequence for detecting major vascular abnormalities during the hyperacute phase of stroke: a comparison with MR angiography.

In the hyperacute phase of stroke, occluded vessels can be seen as high signal on fast-FLAIR images or as absence of flow-related enhancement in maximum-intensity projection (MIP) MR angiography (MRA). To compare these techniques, we examined 53 patients within 6 h of a stroke, using a standardised MRI protocol including fast-FLAIR and 3D time-of-flight TOF MR to detect vessel occlusion or reduced flow corresponding to the suspected ischaemic territory. Brain infarcts were confirmed on MRI after 1-5 days in 41 cases (77%). The overall accuracy of 3D-TOF MRA was 68% and sensitivity, specificity, positive and negative predictive values were 67%, 71%, 87%, and 43% respectively. Values for the fast-FLAIR sequence were: 65%, 85%, 93% and 44%, with an overall accuracy of 70%. The fast-FLAIR sequence was thus able to show occluded vessels or reduced flow with about the same accuracy as 3D-TOF MRA and enabled better prediction of the ischaemic area.

Adult↗

Tonsillectomy and adenotomy as a one day procedure?

With special reference to the postoperative hemorrhage rate and its subsequent course, we retrospectively evaluated the outcome of 2,363 tonsillectomies and 3,295 adenotomies performed over the last 11 years at our department. The postadenotomy major bleeding frequency was 0.2%. After tonsillectomy the immediate postoperative major bleeding frequency was 2.6% and 3.0%, respectively in children and adults. Secondary bleeding after tonsillectomy occurred in 0.3% of the children and 0.5% of the adults. In contrast to adenotomy, which can be considered as a safe one day procedure, based on our results we propose to perform tonsillectomy as a more prolonged, one night stay procedure.

Adenoids↗

Clinical relevance of the determination of anti-GQ1b antibodies in Miller Fisher and Guillain-Barré syndromes.

Anti-GQ1b antibodies were assayed by an enzyme-linked immunosorbent assay in sera from patients with non-neurological disorders (N = 20), and with various neurological disorders (N = 59), including nine cases of Miller Fisher syndrome, 16 cases of Guillain-Barré syndrome and one case of acute post-infectious ophthalmoparesis. Such antibodies were found in most cases (8 out of 9) of Miller Fisher syndrome, and at very high titres, in one case of Guillain-Barré syndrome characterised by an initial ophthalmoparesis, and in the case of isolated post-infectious ophthalmoparesis. The latter was characterised by a long-lasting occurrence of these antibodies. Anti-GQ1b antibodies are specific for an immune-mediated neuropathy of the cranial, especially oculomotor, nerves.

Autoantibodies↗