Search

Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative modification. On the basis of repeated coronary angiography, 28 coronary bypass patients were divided into two groups: group A, 12 patients with, and group B, 16 patients without progression of coronary atherosclerosis. The lag time, reflecting the resistance of LDL to oxidative modification, was significantly smaller in group A as compared with group B (81 +/- 10 and 93 +/- 15 min, respectively). Besides differences in cholesterol and apolipoprotein B concentrations, the difference in susceptibility of LDL to oxidation significantly contributes to the differences between the progression and the non-progression group (P = 0.02). In the combined groups of patients, the lag phase of LDL for oxidation was positively correlated with LDL cholesterol ester to protein ratio (r = 0.53, P = 0.01). It is concluded that LDL samples obtained from coronary bypass patients differ with respect to their oxidizability depending on progression of atherosclerosis following coronary bypass surgery.

Increased effort of retrieval from memory is considered to be a feature of cognition in subcortical neurological diseases, such as multiple sclerosis (MS). Free word association provides a means to investigate alterations in automatic and effortful retrieval. Using this procedure we investigated whether in MS free word association would shift from commonality towards idiosyncrasy, as a result of effortful, controlled retrieval. The MS group consisted of a cohort of outpatients, who suffered from chronic but quiescent MS. The patients responded with perfectly normal association patterns. Apparently, impairment of retrieval, or more specifically increased effort of retrieval, from memory does not hold true generally in MS. In patients with obvious physical handicaps (mean Kurtzke DSS = 4 +/- 2) we could not demonstrate abnormal associative processes.

Magnetic resonance (MR) imaging has been shown to provide accurate measurements of right ventricular (RV) volumes and myocardial mass. The purpose of this study was to evaluate the reproducibility of MR imaging, which in clinical practice may be as important as its absolute accuracy. The reproducibility of MR imaging measurements of the right ventricle was assessed by analyzing 40 serial functional MR imaging examinations of the right ventricle with variance component analysis. Standard deviations and 95% ranges for change were: for RV myocardial mass, 5.9 and 16 g; and for RV ejection fraction, 6.0% and 16%, respectively. Reproducibility was similar for cine and spin-echo MR imaging. The intraobserver and interobserver errors were especially large, indicating that observer subjectivity is the limiting factor in the interpretation of the MR images. This study suggests that the reproducibility of RV measurements is adequate to detect RV hypertrophy and a low ejection fraction in the individual patient. For accurate follow-up examinations, whereby smaller changes are to be detected, the reproducibility of MR imaging measurements may not be sufficient. More effort is needed to improve the reproducibility of MR imaging measurements.

We studied the influence of dietary protein intake on the plasma level profile of levodopa, carbidopa, and 3-O-methyldopa and clinical efficacy in 12 patients with idiopathic Parkinson's disease after intake of one levodopa-carbidopa 200/50 controlled release tablet (Sinemet CR; LC-CR). The tablet was given 1 h before the protein rich meal on one day (fasted) and together with the meal on an other day (non-fasted). Higher levodopa and carbidopa concentrations were reached when the LC-CR was taken 1 h before the meal, but the plasma level profile for levodopa was flatter in the non-fasted state. The area under the curve for levodopa was slightly higher in the fasted condition. For the clinical variables walking and tapping slightly better clinical results (P = 0.08) were found in the fasted condition with the higher levodopa levels. If the patient on levodopa is in a clinically satisfactory condition, then non-fasted condition could be preferred because of the smooth plasma level profile demonstrated. However, if the initial levodopa concentrations are not in the critical range to be effective for the patient, the advice should be to take the drug in a fasted condition.

SPECT with Tc-99m HM-PAO as a radiopharmaceutical was performed in 17 patients meeting research criteria for Alzheimer's disease (AD), in 10 patients with a clinical diagnosis of multi-infarct-dementia (MID) and in 12 healthy volunteers. Regional tracer uptake was measured in frontal, parietal, and temporoparietal regions. A statistically significant decrease of tracer uptake in the temporoparietal region was found in AD-patients compared with controls. AD-patients showed less activity in this region than MID-patients, but this difference did not reach statistical significance. In both AD- and MID-patients decrease of tracer uptake was not correlated with dementia severity. We conclude that SPECT brain imaging is not yet ready for routine use in the distinction between AD and MID.

This study reports on a 4-year follow-up of cognitive functioning in 33 MS patients and 18 healthy control subjects. As a group, and in agreement with the results in the previous assessment. MS patients have significantly weaker performances than controls in motor speed, reaction time, learning tasks, reading aloud and figure copying. Tasks addressing visuospatial problem solving, behavioural flexibility, and linguistic aspects of oral and written communication do not distinguish between the two groups. Influence of impaired movement is acknowledged in performances utilising speech and reading under instructions of speed, and in figure copying. Cognition per sé remained undisturbed in 25 patients (76%). A uniform MS-related development of cognitive deficits could not be identified, improvement, stability and further deterioration being found at reassessment.

In 22 (56%) of 39 quiet-stage multiple sclerosis (MS) patients with at least average intelligence quotients, performances in memory and learning tasks were normal, as compared with those of a control group (24 healthy volunteers). Of the remaining 44% (n = 17), 2 patients were amnesic and 5 had been judged to have suffered cognitive decline. Auditory word learning was particularly vulnerable; however, acquisition rate was not significantly different between MS patients and controls.

In a group of 39 multiple sclerosis (MS) patients with at least average intelligence quotients (IQ), performances were examined in tests requiring language usage and figure copying. Numbers of correct, digressive and erroneous responses were analysed and compared with those obtained in 24 healthy volunteers, matched to the patients group for socio-economic status. The examined specific tasks yielded no additional contribution to the prevalence estimation of cognitive deterioration (18%), as based on an assessment of general intelligence. Linguistic or cognitive-constructional problems were no more severe or more frequent in MS patients than those in control subjects. Upon writing or copying figures, pencil stroke and pencil pressure were deficient. Speed of reading aloud and of colour naming was decreased in the MS group, the most probable explanation being impaired control of the phonatory apparatus, oculomotor problems or weakness of colour vision. Decreases in speed of performance are not necessarily of cognitive origin. Differences between the present and previous reports based on similar tasks, appear to be connected partly with differences in patient selection. Of the present group, all MS patients were in quiescent disease stages, depression was mild or absent and physical handicap was less than in most studies reporting definite specific deficits.

Reaction times (RT) were measured in 39 multiple sclerosis (MS) patients and 25 healthy controls, before and after comprehensive neuropsychological assessment lasting at least 4 h. The assessment required prolonged mental effort, which was assumed to induce fatigue. Simple and disjunctive RT were measured for visual and auditory stimuli. RT before and after prolonged effort were significantly longer in MS than in control subjects (with exception of auditory RT). This effect was related to disease duration and to simultaneous presence of brainstem, cerebellar and/or pyramidal signs. Age did not significantly contribute to the explanation of RT increase. In female patients, increasing distribution of functional lesions in the central nervous system was related with greater RT increase than in male patients. RT of MS and controls changed after prolonged mental effort and effort-related fatigue was experienced subjectively. Yet no differences in direction or degree of change in RT were found between controls and ambulant patients with stable MS who apparently had resources to overcome fatigue.

Investigations on diet, body weight, and lipoproteins were carried out in 28 patients with stable angina pectoris. They consumed a linoleic acid-enriched diet (P/S ratio = 2) for a period of 2 years. The total fat content remained constant before and during intervention, contributing 34% to energy intake. During intervention serum total cholesterol and the total/HDL cholesterol ratio decreased significantly, but HDL cholesterol did not change. Changes in body weight were significantly inversely related to changes in HDL cholesterol and positively to the total/HDL cholesterol ratio. Changes in alcohol intake were significantly positively related to both total and HDL cholesterol but unrelated to the total/HDL cholesterol ratio. From the results of this long-term study it can be concluded that a moderate fat diet with a P/S ratio of 2 can lower total cholesterol effectively without affecting HDL cholesterol.

A group of 89 patients in whom multiple sclerosis (MS) has been clinically diagnosed with varying degrees of certainty, and 25 patients with optic neuritis (ON), were subjected to the following electrophysiological tests: visual evoked response (VER), auditory brainstem-evoked response (ABER), somatosensory-evoked response (SSER), blink reflex and electronystagmography (ENG). All these patients also underwent computerized tomography (CT scan) and analysis of cerebrospinal fluid (CSF). A new diagnostic procedure is proposed, combining optimum detection of definite MS with optimally economical use of the above-mentioned non-clinical tests. The results for the MS patients show that definite MS can be diagnosed much more frequently (72%) if abnormal results in the above-mentioned tests are accepted as evidence of a (subclinical) CNS lesion. Application of the clinical diagnostic criteria of McAlpine yielded "definite MS" only in 27% of our patient material. Our diagnostic criteria showed evidence for MS in 36% of the patients clinically diagnosed as having ON. The test results were inconclusive as regards the possibility of the remaining ON patients developing MS in the future.

Visuospatial problem solving, conceptual reasoning and shifting of set were studied in out-patients with definite and probable MS. The sample of MS patients was homogeneous with respect to 2 important dimensions. All were out-patients, leading a normal although handicap-restricted social life. Furthermore, in all patients relapse or obvious instability of the disease were absent for at least a month. On Raven's Progressive Matrices, the Category test and the Wisconsin Modified Card Sorting test, no significant differences were found between the group of MS patients and a control group of healthy volunteers. However, 18% of MS patients and 4% of controls were rated as performing slightly below the expected levels of cognition. Stepwise regression analysis failed to reveal effects of illness variables, and no difference between patients with definite and probable MS could be detected. Clearly, most socially integrated MS patients in stable disease stages are capable of normal visuospatial problem solving, abstract reasoning and shifting of set.

In view of recent reports on lower brainstem dysfunction in Huntington's chorea, we studied respiration during sleep in 12 patients with Huntington's chorea (HC) and in controls. There were no statistically significant differences between patients and controls with respect to apnea periods, respiratory frequency and time elapsed between minimal and maximal value of the respiratory curve. No statistically significant differences in respiratory variability were observed between patients and controls. In the present study, no indication was found for dysfunction of lower brainstem structures involved in respiration in HC.

Somatosensory evoked potentials were measured in 21 patients with Huntington's chorea and 12 controls. Central brain conduction time was normal. Early cortical component amplitudes were reduced in the patient group, latencies were normal. These abnormalities probably can be attributed to cortical dysfunction in Huntington's chorea. No indication of brain-stem dysfunction was found.

Effects of task variables on reaction time (RT) were investigated in 39 multiple sclerosis (MS) patients and 25 matched control subjects, based on the premise that RT is sensitive to (subtle) changes of cognitive efficiency. The hypothesis to be tested held that inefficient cognitive processing in MS would be reflected in differences between RT patterns of MS and control subjects, and in inordinate RT increase in MS patients with increase of task complexity. No difference was found between MS patients and controls, or between MS subgroups, in (1) response to time uncertainty of stimulus presentations, (2) RT behaviour over stimulus presentations, and (3) RT change from simple to more complex conditions. No evidence of slowed cognitive processing was found in this sample of outpatients with relatively mild and stable MS. It is emphasised that executive and cognitive slowness have to be disentangled in research on MS and on so-called 'subcortical dementia', of which mental slowing is a key concept.

Fifty-one families of patients affected with Huntington's chorea were interviewed with respect to age at onset, symptoms at onset and course of the disease. The interview further comprised questions pertinent to line of transmission, socio-economic status, housing, previous illnesses and pregnancy and stillbirth. Since the study was set up as a fishing expedition detailed quantitative information was gathered on many life-style factors including eating, drinking and smoking habits. In adult age onset cases earlier age at onset correlated with lower rate of progression. Line of transmission was of no influence on age at onset in cases with onset above 20 years. No statistically significant relationship was found between any factor studied and age at onset, except for the intake of milk. Higher previous milk intake was associated with earlier ages at onset. This finding is critically discussed. No difference was found between the respective ages at onset of conduct disorders and affective disorders. This suggests that they are both associated with the Huntington gene.