Matter-wave interference of a native polypeptide.

The de Broglie wave nature of matter is a paradigmatic example of quantum physics and it has been exploited in precision measurements of forces and fundamental constants. However, matter-wave interferometry has remained an outstanding challenge for natural polypeptides, building blocks of life, which are fragile and difficult to handle. Here, we demonstrate the wave nature of gramicidin, a natural antibiotic composed of 15 amino acids. Its center of mass is delocalized over more than 20 times the molecular size in our time-domain Talbot-Lau interferometer. We compare the observed interference fringes with a model that includes both a rigorous treatment of the peptide's quantum wave nature as well as a quantum chemical assessment of its optical properties to distinguish our result from classical predictions. The realization of quantum optics with this prototypical biomolecule paves the way for quantum-assisted measurements on a large class of biologically relevant molecules.

Pharmacogenetics: the Rx perspective.

Pharmacogenetics is changing the way medicines are discovered, developed and delivered to patients. In this article, we present the 'prescription' perspective--how the results of pharmacogenetic research will help minimize the risk of costly adverse drug reactions and treatment failures, by providing predictive tools to enable healthcare providers to prescribe the right medicine for the right patient. We discuss the challenges of this research and its clinical application; its implications for drug development; evolving concepts of informed consent; related ethical, legal and social issues; changing definitions of 'genetic testing'; and the creation of an international Pharmacogenetics Working Group.

Elevated plasma concentrations of lipoprotein(a) in medicated epileptic patients.

Lipoprotein(a) [Lp(a)] has been identified as an independent risk factor for vascular diseases. There are no data on Lp(a) levels in patients on long-term medication with carbamazepine, phenytoin, phenobarbital, or valproate. To investigate the effects of such treatment on Lp(a) levels and common carotid artery intima media thickness we studied 51 epileptic outpatients on long-term antiepileptic medication and 51 age-and sex-matched controls. Lp(a) levels above 45 mg/dl were found in 11 of 50 patients, but in only 4 of 51 controls (P < 0.05). The mean serum concentration of Lp(a) was 33.0+/-7.0 mg/dl in patients and 16.9+/-2.7 mg/dl in controls (P < 0.05). Epileptic patients also had a thicker intima media of the common carotid artery (0.79+/-0.04 mm) than controls (0.69+/-0.02 mm, P < 0.05) as measured by B-mode ultrasonography. Our results suggest an untoward effect of long-term antiepileptic medication on Lp(a) serum concentrations. Elevated Lp(a) levels might be a risk factor for arteriosclerosis in epileptic patients.

Family consent and the pursuit of better medicines through genetic research.

Rapid changes in the science and technology related to genetic research are challenging scientists, health care providers, ethicists, regulators, patient groups, and the pharmaceutical industry to keep pace with ethically grounded, workable guidelines for both the research and clinical applications of human genetics. We describe the genetic research being conducted by one pharmaceutical company (GlaxoSmithKline) and how the company is addressing the ethical, legal, and social issues surrounding this research; discuss an industry working group's attempt to advance pharmacogenetic research by openly addressing and disseminating information on related ethical, legal, and regulatory issues; identify scientific and ethical differences among various types of genetic research; discuss potential implications of family consent on subject privacy and autonomy, data collection, and study conduct; and suggest points to consider when study sponsors, investigators, and ethics committees evaluate research proposals. Public and expert opinion regarding informed consent in genetic research is evolving as a result of increased education, discussion, and understanding of the relevant issues. Five years ago, there was strong support for anonymity in genetic research as a privacy safeguard. Now, an increasingly popular school of thought advocates against anonymity to preserve an individual's ability to withdraw and, if desired, access research results. It is important to recognize this evolution and address consent issues in a reasoned, practical, and consistent way, including input from patients and their families, health care providers, ethicists, scientists, regulatory bodies, research sponsors, and the lay community. Responsibility for assessing issues related to family consent for research should remain with local investigators, ethics boards, and study sponsors. A "one-size-fits-all" perspective in the form of new regulations, for example, would likely be a disservice to all.

Educational, psychologic, and social aspects of short stature.

Children with short stature may experience academic difficulties, psychologic impairment, and emotional stress related to an underlying medical condition or social stigmatization. Educational and psychosocial problems associated with short stature often can be alleviated with appropriate interventions. Parents, health-care practitioners, and teachers should be aware of the potential academic, psychologic, and social problems related to short stature and growth delay, so they can support the short child's normal development and intervene promptly if problems arise.

[Epidemiological studies of the frequency of the abuse of analgesics]. / Epidemiologische Untersuchungen zur Häufigkeit des Analgetika-Abusus.

To assess the epidemiology of habitual use of analgesics in South-West Germany (i) urine specimens of employees of a factory, of patients seen by a general practitioner (GP) and of patients attending a renal clinic were examined for paracetamol; (ii) mucosa of the left renal pelvis was examined for the presence of capillary sclerosis as an index of habitual use of phenacetin or paracetamol in 258 consecutive autopsies; (iii) in a regional renal clinic, the frequency of analgesic nephropathy was determined amongst outpatients and amongst patients on hemodialysis. Paracetamol was found in the urine of 4.1% of factory employees, in 3.5% of patients seen by a GP and in 2% of patients seen in the renal clinic. Capillary sclerosis was found in only one of 258 autopsies, in a patient dialysed for analgesic nephropathy. During the past two years, analgesic nephropathy was diagnosed in 3% of all patients seen for nephrological examination. Analgesic nephropathy was the cause of terminal renal failure in 15 of 166 patients (9.4%) on dialysis. The present study documents that habitual use of paracetamol-type analgesics continues in the general population despite the ban of phenacetin.

Elevated plasma concentrations of homocysteine in antiepileptic drug treatment.

PURPOSE: Homocysteine is an experimental convulsant and an established risk factor in atherosclerosis. A nutritional deficiency of vitamin B6, vitamin B12, or folate leads to increased homocysteine plasma concentrations. During treatment with carbamazepine (CBZ), phenytoin, or phenobarbital, a deficiency in these vitamins is common. The objective of the study was to test the hypothesis that antiepileptic drug (AED) treatment is associated with increased homocysteine plasma concentrations. METHODS: A total of 51 consecutive outpatients of our epilepsy clinic receiving stable, individually adjusted AED treatment and 51 sex- and age-matched controls were enrolled in the study. Concentrations of total homocysteine and vitamin B6 were measured in plasma; vitamin B12 and folate were measured in the serum of fasted subjects. RESULTS: Patients and controls differed significantly in concentrations of folate ( 13.5+/-1.0 vs. 17.4+/-0.8 nM and vitamin B6 (39.7+/-3.4 vs. 66.2+/-7.5 nM), whereas serum concentrations of vitamin B12 were similar. The homocysteine plasma concentration was significantly increased to 14.7+/-3.0 microM in patients compared with controls (9.5+/-0.5 microM; p < 0.05, Wilcoxon rank-sum test). The number of patients with concentrations of >15 microM was significantly higher in the patient group than among controls. The same result was obtained if only patients with CBZ monotherapy were included. Patients with increased homocysteine plasma concentrations had lower folate concentrations. CONCLUSIONS: These data support the hypothesis that prolonged AED treatment may increase plasma concentrations of homocysteine, although the alternative explanation that increased homocysteine plasma concentrations are associated with the disease and not the treatment cannot be completely excluded at the moment.