Determination of 3,4-dihydroxyphenylalanine (DOPA) in plasma and cerebrospinal fluid by high performance liquid chromatography with electrochemical detection

We report a reliable method for determining DOPA levels in plasma and cerebrospinal fluid. The method is based on complete conversion of DOPA to dopamine and quantification by HPLC-ECD of the dopamine formed. Lower limit of detection was 0.5 nmol/l. No differences in plasma DOPA levels were found between normal children (0-15 yr, n = 60), normal adults (n = 39) and patients with essential hypertension (n = 40) or Parkinson's disease (no DOPA therapy, n = 30). In normal individuals and in patients with essential hypertension venous plasma levels were higher than arterial levels (10.2 vs 9.3 nmol/l, p less than 0.001, V/A ratio 1.11 (SD 0.08), n = 15). Sympathetic stimuli (standing, tilting, bicycle exercise, tyramine) did not influence DOPA levels. In untreated depressed patients (n = 10) and in non-parkinsonian neurological patients (n = 12) cerebrospinal fluid levels of DOPA were 4.5 (SD 2.4) and 5.2 (SD 1.3) nmol/l respectively. A direct method for the measurement of DOPA by HPLC-ECD after deproteinization of plasma is also described and compared with the conversion method. Good agreement was found when plasma DOPA levels exceeded 0.25 mumol/l (y(conversion method) = 0.943x (direct method) + 0.118; n = 60; r = 0.985). The direct method, because of greater simplicity and the possibility of simultaneous measurement of the DOPA metabolite 3-O-methyldopa, is the method of choice with plasma samples from DOPA-treated patients. In non-DOPA treated individuals the conversion method is superior and has proved to be an accurate and sensitive method for the determination of DOPA levels in plasma and cerebrospinal fluid.     

Frequency, nature and determinants of pharmaceutical consultations provided in private by Dutch community pharmacists

OBJECTIVE: According to a report published by the federation of Dutch patients' associations, patients would like to see a pharmacist, who acts more as a personal adviser. This raised the question, how often Dutch community pharmacists have personal consultations with their patients in daily practice, on which factors this depends, and what kind of topics are discussed during these meetings. SETTING: Community pharmacies in the Netherlands. METHOD: A questionnaire was distributed among 800 randomly selected pharmacies. Questions were restricted to consultations characterized by one-to-one contact, drug therapy related content, and adequate privacy. These consultations were labelled as pharmaceutical consultations in private to distinguish them from other contacts between pharmacists and patients. MAIN OUTCOME MEASURE: Number, content, and character of consultations. RESULTS: 198 (24.8%) community pharmacies responded. The pharmacists provide an average of roughly 1.2 consultations in private per working day. The vast majority of respondents provided face-to-face and telephone consultations (94.4 and 91.9%, respectively), only a minority gave consultations by e-mail (30.8%). These consultations primarily dealt with topics related to medication safety. The mean overall time spent was 290 min per month. A relatively high frequency of personal consultations was significantly associated with the absolute number of full-time equivalent pharmacists in the pharmacy. CONCLUSION: The frequency of pharmaceutical consultations in private is low, but may be improved by reorganisation of the pharmacist's activities. The possibility of personal consultations by e-mail is not yet well-developed. Further research is needed to assess the patient's view of pharmaceutical consultations in private.     

Optimal Selection of Sib Pairs from Random Samples for Linkage Analysis of a QTL Using the EDAC Test

Percentages of extremely concordant and extremely discordant sib pairs are calculated that maximize the power to detect a quantitative trait locus (QTL) under a variety of circumstances using the EDAC test. We assume a large fixed number of randomly sampled sib pairs, such as one would hope to find in the large twin registries, and limited resources to genotype a certain number of selected sib pairs. Our aim is to investigate whether optimal selection can be achieved when prior knowledge concerning the QTL gene action, QTL allele frequency, QTL effect size, and background (residual) sib correlation is limited or absent. To this end we calculate the best selection percentages for a large number of models, which differ in QTL gene action allele frequency, background correlation, and QTL effect size. By averaging these percentages over gene action, over allele frequency, over gene action, and over allele frequencies, we arrive at general recommendations concerning selection percentages. The soundness of these recommendations is subsequently in a number of test cases.     

The HIV prevalence among pregnant women in the Amsterdam region (1988–1991)

The objective of the study was to monitor the HIV prevalence in the years 1988–1991 among pregnant women in the Amsterdam region, visitors to an abortion clinic and 3 outpatient infertility clinics. All women attending these clinics were asked to participate in the study on a voluntary basis and were tested with informed consent. The women were questioned about risk-bearing behaviour of themselves and their sexual partner(s). In the period 1988–1991, of the 23,827 eligible pregnant women, 22,165 women participated (93.0%). Twenty-seven women were found to be positive for HIV antibodies (0.12%, 95% CI: 0.08%–0.17%), of whom twenty belonged to a known HIV risk group or had a partner who belonged to one of these groups and 7 women had no known HIV risk. Seventeen of the 27 women had a foreign nationality. The annual HIV prevalence among pregnant women was: 1988: 0.28%; 1989: 0.10%; 1990: 0.10%; 1991: 0.11%. In the years 1990 and 1991, of the 1,128 eligible women visiting the abortion clinic 953 (84.5%) were tested. Eleven women were HIV-seropositive (1.15%, 95% CI: 0.6%–2.0%), of whom 9 were from an AIDS endemic region, 1 woman had a partner from this region and 1 woman had no known HIV risk. Four African women had HIV-2 antibodies. At the 3 outpatient infertility clinics 1 woman was found to be HIV-positive (0.13%; 95% CI: 0.02–0.9). She had no other risk than a partner from an AIDS endemic area. In the Amsterdam region there was a steady and low HIV prevalence (0.1%) among pregnant women through the years 1988–1991. The prevalence in the abortion clinic was ten times higher. The program was able to detect possible high risk groups within the population. Migration and travelling can play an important role in the spread of HIV in the general heterosexual population.     

The Dutch twin register: Growth data on weight and height

As part of a longitudinal developmental study of newborn and young Dutch twins, data on weight and height are collected. Birth weight and height are available for 3275 pairs; data on growth, for 1390 pairs.     

Acute effects of the ampakine farampator on memory and information processing in healthy elderly volunteers.

Ampakines act as positive allosteric modulators of AMPA-type glutamate receptors and facilitate hippocampal long-term potentiation (LTP), a mechanism associated with memory storage and consolidation. The present study investigated the acute effects of farampator, 1-(benzofurazan-5-ylcarbonyl) piperidine, on memory and information processes in healthy elderly volunteers. A double-blind, placebo-controlled, randomized, cross-over study was performed in 16 healthy, elderly volunteers (eight male, eight female; mean age 66.1, SD 4.5 years). All subjects received farampator (500 mg) and placebo. Testing took place 1 h after drug intake, which was around Tmax for farampator. Subjects performed tasks assessing episodic memory (wordlist learning and picture memory), working and short-term memory (N-back, symbol recall) and motor learning (maze task, pursuit rotor). Information processing was assessed with a tangled lines task, the symbol digit substitution test (SDST) and the continuous trail making test (CTMT). Farampator (500 mg) unequivocally improved short-term memory but appeared to impair episodic memory. Furthermore, it tended to decrease the number of switching errors in the CTMT. Drug-induced side effects (SEs) included headache, somnolence and nausea. Subjects with SEs had significantly higher plasma levels of farampator than subjects without SEs. Additional analyses revealed that in the farampator condition the group without SEs showed a significantly superior memory performance relative to the group with SEs. The positive results on short-term memory and the favorable trends in the trail making test (CTMT) are interesting in view of the development of ampakines in the treatment of Alzheimer's disease and schizophrenia.     

Assessment of global and regional left ventricular function and volumes with 64-slice MSCT: a comparison with 2D echocardiography.

BACKGROUND: In patients with coronary artery disease (CAD), LV function and volumes are important parameters for long-term prognosis. Multislice computed tomography (MSCT) allows noninvasive assessment of the coronary arteries, but the accuracy of 64-slice MSCT for the assessment of left ventricular (LV) volumes and function is unknown. METHODS AND RESULTS: A head-to-head comparison between 64-slice MSCT and 2-dimensional (2D) echocardiography was performed in 40 patients with known or suspected CAD. The LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) were determined and the LV ejection fraction (LVEF) was derived. Regional wall motion was assessed visually using a 17-segment model. A 3-point scoring system was used to assign to each segment a wall motion score: 1 = normokinesia, 2 = hypokinesia, 3 = akinesia or dyskinesia. Two-dimensional echocardiography served as the gold standard. MSCT agreed well with 2D echocardiography for assessment of LVEDV (r = 0.97; p < .0001) and LVESV (r = 0.98; p < .0001). An excellent correlation between MSCT and 2D echocardiography was shown for the evaluation of LVEF (r = 0.91; p < .0001). Agreement for the assessment of regional wall motion was excellent (96%, kappa = 0.82). CONCLUSIONS: An accurate assessment of global and regional LV function and volumes is feasible with 64-slice MSCT.     

Cerebrovascular involvement in Ehlers-Danlos syndrome

Opinion statement Ehlers-Danlos syndrome type IV is one of the most prominent heritable disorders of connective tissues associated with neurovascular disease. It is an uncommon disorder characterized by thin translucent skin, distinctive facial features, excessive bruising, and rupture of blood vessels or viscera. The typical neurovascular complications of this syndrome are carotid cavernous fistulas, intracranial aneurysms, and cervical artery dissections. Because of the inordinate fragility of the blood vessels in patients with this syndrome, conservative treatment is always indicated. However, in select cases in which the person or family history indicates a more benign form of the disease, treatment that includes surgical or endovascular treatment of asymptomatic lesions may be indicated.