Sudden daytime sleep onset in Parkinson's disease: polysomnographic recordings.

Sleep attacks in Parkinson's disease are controversially discussed. This paper describes a patient with Parkinson's disease suffering from sudden, irresistible onset of sleep during daytime. Medication included levodopa, entacapone, budipine, and cabergoline. Introduction of entacapone was the last therapeutic action preceding onset of sleep events, suggesting increased bioavailabilty of levodopa to be provocative in this case. In contrast to previous cases, the sudden sleep events were witnessed by clinical staff members and documented by polysomnographic and video recordings. Polysomnography during these sleep events remarkably showed abrupt slowing of EEG-background activity and occurrence of slow eye movements and K-complexes within 10 seconds after stable wakefulness. Within 60 seconds, the polysomnographic pattern proceeded to stable sleep stage 2.     

Experimental and clinical evaluation of stomatological cleaning agents with special reference to the Eladent prosthesis cleaner]

The experimental and clinical testing of certain denture cleaners, viz., Eladent, Kukident and Steradent, yielded identical good results. As far as possible, Eladent should be dissolved in warm water (35-40 degrees C). In this case, the tablets will dissolve within 15-20 minutes. For immediate cleaning, the tablets may be dissolved within 1 or 2 minutes by raising the water temperature at 50 degrees C. No striking immediate effect can be expected from this cleaner in case of stained dentures which have been worn for many years. The cleaner improves little by little the hygienic condition of the denture. It is recommended to apply the cleaning tablets immediately after insertion of the prosthesis at regular intervals. In this way, soft deposits and plaques will no longer adhere and cause the formation of hard deposits.     

Interference of rhythmic constraint on gait in healthy subjects and patients with early Parkinson's disease: evidence for impaired locomotor pattern generation in early Parkinson's disease.

Patients in the early stages of Parkinson's disease have been shown to walk slower with smaller steps, resembling the gait of normal elderly subjects, but specific disorders of dynamic equilibrium or rhythmic gait patterning have not yet been identified. In the present study, gait control in 22 healthy subjects and 22 patients with early Parkinson's disease was challenged by means of a paradigm requiring subjects to decrease their step rate (cadence) by 20% in response to a metronome signal (rhythmic constraint). Control subjects and patients were matched for age, sex, and body height. Eleven patients were receiving standard antiparkinsonian therapy and were assessed under their ongoing medication, whereas the remaining 11 patients had not yet been started on dopaminergic therapy ("de novo" Parkinson's disease). Gait parameters reflecting dynamic equilibrium (double-support time) and locomotor patterning (step length, stride duration) were recorded by means of a mechanical device (locometer). Sixteen patients and 16 control subjects were able to accomplish the task. Whereas regulation of step length became irregular during rhythmic constraint in both patients and control subjects, irregular timing of steps was only observed in patients suggesting disturbance of periodic locomotor activity generation.     

Rhythmic feet movements while falling asleep.

During the wake-sleep transition and sleep, diverse motor phenomena such as hypnagogic foot tremor may occur in the lower extremities. We investigated the relevance of this phenomenon in 375 consecutive subjects examined polysomnographically in a sleep disorders center. Rhythmic feet movements while falling asleep (RFM) were found in 28 subjects (7.5%). RFM occurred mostly as single, short series with a duration of between 10 and 15 seconds. They had a high night-to-night variability and were detected as rhythmic, oscillating movements of the whole foot or toes. Surface electromyographic (EMG) recordings displayed series of repetitive phasic bursts with a periodicity mostly between 1 and 2 per second. Single EMG burst duration varied between 300 and 700 msec. RFM at highest intensity occurred during presleep wakefulness, and usually persisted in sleep stages 1 and 2. RFM did not have a major sleep-disturbing effect in any of the affected subjects. Due to its high prevalence and the lack of a major sleep-disturbing effect, short series of RFM could be considered a quasiphysiological phenomenon. However, in more severe forms of RFM with evidence of a sleep-disturbing effect, RFM should be considered abnormal.     

Using electronic flashcards to promote learning in medical students: retesting versus restudying

Medical Education 2011: 45 : 1101–1110 Context The superiority of retesting over restudying in terms of knowledge retention and skills acquisition has been proven in both laboratory and classroom settings, as well as in doctors’ practice. However, it is still unclear how important retesting strategies are to the learning of relevant factual knowledge in undergraduate medical education. Methods Eighty students in Years 3–5 of medical school in Munich participated in a prospective, randomised, double‐blinded, controlled study in which they were exposed to 30 electronic flashcards designed to help them memorise key factual knowledge in the domain of clinical nephrology. The flashcards were presented in four successive learning cycles, each consisting of a study period and a subsequent test period. Half of all participants were randomised to repetitive studying (restudy group) and half were randomised to repetitive testing (retest group) of successfully memorised flashcards. Knowledge retention was assessed after 1 week and 6 months. Additionally, personal data, self‐reflection on the efficacy of the learning strategies and judgements of learning were obtained by questionnaires. Results Repetitive testing promoted better recall than repetitive studying after 1 week (p < 0.001). However, after 6 months general recall was poor and no difference between the restudy and retest groups was observed. Time on task and number of trials, in addition to sex, age, performance and psycho‐social background, did not vary between the groups. Self‐predictions of student performance did not correlate with actual performance. Conclusions In the context of using electronic flashcards, repetitive testing is a more potent learning strategy than repetitive studying for short‐term but not long‐term knowledge retention in clinical medical students. Although students use testing as a learning strategy, they seem to be unaware of its superiority in supporting short‐term knowledge retention.     

Xylo-oligosaccharides inhibit pathogen adhesion to enterocytes in vitro

We previously reported that the non-digestible carbohydrates inulin and apple pectin promoted Listeria monocytogenes infection in guinea pigs, whereas xylo- and galacto-oligosaccharides (XOS and GOS), prevented infection by this pathogen. In the present study, mechanisms that could explain the previous in vivo observations were explored. Mixing bacterial cultures with XOS significantly (P < 0.05) decreased the ability of two out of three strains of L. monocytogenes to adhere to Caco-2 cells. Additionally, 2 h incubation with XOS followed by washing of the bacteria significantly (P < 0.05) decreased the ability of all three strains to adhere to Caco-2 cells. Consistently, expression of the adhesion-relevant genes inlA and lap was reduced by the presence of XOS. The observation that XOS inhibit the adhesion of Listeria to the intestinal epithelium in vitro may explain the reported preventive effect of XOS on Listeria infection in guinea pigs in vivo, while the preventive effect of GOS was not explicable by the assays chosen here.     

The double par locus of virulence factor pB171: DNA segregation is correlated with oscillation of ParA

Prokaryotic plasmids and chromosomes encode partitioning (par) loci that segregate DNA to daughter cells before cell division. Recent database analyses showed that almost all known par loci encode an ATPase and a DNA-binding protein, and one or more cis-acting regions where the proteins act. All par-encoded ATPases belong to one of two protein superfamilies, Walker-type and actin-like ATPases. This property was recently used to divide par loci into Types I and II loci. We show here that the Escherichia coli virulence factor pB171 encodes a double par locus that consists of one Type I and one Type II locus. Separately, each locus stabilized a test-plasmid efficiently. Together, the two loci mediated even more efficient plasmid stabilization. The par loci have a unique genetic organization in that they share a common central region at which the two different DNA-binding proteins probably act. Interestingly, a fusion protein consisting of the Walker-type ParA ATPase and Gfp was functional and oscillated in nucleoid regions on a time scale of minutes. ParA-green fluorescent protein (Gfp) oscillation depended on both ParB and parC but was independent of minCDE. Point mutations in the Walker A box motif simultaneously abolished plasmid stabilization and ParA-Gfp oscillation. These observations raise the possibility that ParA oscillation is prerequisite for active plasmid segregation.