"What watch?...such much!" Complexity and evolution of circadian clocks.

This review uses three examples to summarise our knowledge about the complexity and the evolution of circadian systems. The first example describes the ecology of unicellular algae, which use their circadian system to optimise the daily exploitation of resources that are spatially separated. The second example looks at the role of clocks in tissues and cells within a complex organism, and the third speculates on how the circadian system may have evolved.

Light reception and circadian behavior in 'blind' and 'clock-less' mutants of Neurospora crassa.

The filamentous fungus Neurospora crassa is a model organism for the genetic dissection of blue light photoreception and circadian rhythms. WHITE COLLAR-1 (WC-1) and WC-2 are considered necessary for all light responses, while FREQUENCY (FRQ) is required for light-regulated asexual development (conidia formation); without any of the three, self-sustained (circadian) rhythmicity in constant conditions fails. Here we show that light-regulated and self-sustained development occur in the individual or mutant white collar strains.

Neuropsychological performance and mood states following acute interferon-beta-1b administration in healthy males.

Interferon-beta-1b (IFN-beta-1b) has been shown to reduce the relapse rate in patients with relapsing-remitting multiple sclerosis (MS) and disease progression in patients with secondary progressive MS. While acute administration of IFN-beta-1b is known to cause flu-like symptoms, chronic medication has been suggested to cause mood alterations and anxiety attacks, and secondary to this neuropsychological deficits that may impair daily life. It is unknown, however, whether the latter symptoms are induced by acute IFN-beta-1b administration.

Pilot testing of the 'Haemo-QoL' quality of life questionnaire for haemophiliac children in six European countries.

In a multinational working group, an instrument (Haemo-QoL) to assess quality of life in children/adolescents with haemophilia and their parents has been developed. In co-operation with haemophilia treatment centres in six European countries, approximately 10 children/adolescents with haemophilia per country and their parents were asked to participate in the pilot-testing. Both self-reported and parent-reported questionnaires were provided for two age-groups of children (4-16 years).

Light reception: discovering the clock-eye in mammals.

Light is the most reliable environmental signal for adjusting biological clocks to the 24-hour day. Mammals receive this signal exclusively through the eyes, but not just via rods and cones. New evidence has been uncovered for a novel photoreceptor that may be responsible for more than just adjusting the clock.

Circadian systems: different levels of complexity.

After approximately 50 years of circadian research, especially in selected circadian model systems (Drosophila, Neurospora, Gonyaulax and, more recently, cyanobacteria and mammals), we appreciate the enormous complexity of the circadian programme in organisms and cells, as well as in physiological and molecular circuits. Many of our insights into this complexity stem from experimental reductionism that goes as far as testing the interaction of molecular clock components in heterologous systems or in vitro. The results of this enormous endeavour show circadian systems that involve several oscillators, multiple input pathways and feedback loops that contribute to specific circadian qualities but not necessarily to the generation of circadian rhythmicity.

Seasonality and photoperiodism in fungi.

This review gives a retrospective of what is known about photoperiodism in fungi, which is largely based on reports about seasonal spore concentrations. Relatively few species have been investigated under laboratory conditions, so that our knowledge whether seasonal reproduction in fungi is mainly a direct response to environmental conditions or whether it involves a photoperiodic machinery with memory capacities and a relationship to the circadian system is extremely limited. To form a basis for further experimental endeavors into fungal photoperiodism, we review the reports about endogenous rhythms and photobiology.

A fungus among us: the Neurospora crassa circadian system.

Neurospora crassa is the only molecular genetic model system for circadian rhythms research in the fungi. Its strengths as a model organism lie in its relative simplicity--compared to photosynthesizing and vertebrate organisms, it is a stripped-down version of life. It forms syncitial hyphae, propagates and reproduces, and the circadian clock is manifest in numerous processes therein.

Implications of structural deficits for patient education in Germany.

Several changes in health politics and legal settings in recent years have affected the structure and practice of health promotion and patient education in Germany. The current legal background and its implications for patient education are discussed. Based on examples from four selected areas (cardiovascular diseases, diabetes mellitus, chronic pain, and asthma) the current practice of patient education in Germany is summarized.

Effects of academic stress on oral hygiene--a potential link between stress and plaque-associated disease?

Background: While there seems to be a common belief that psychosocial stress affects oral hygiene behavior, this assumption has rarely been proved. The present study thus aims to analyse stress effects on oral hygiene.

Material And Methods: 16 matched pairs of medical students each consisting of 1 student participating in a major academic exam and 1 control without current academic stress, were formed on the basis of baseline plaque levels.

Diarrhea- and constipation-predominant IBS patients differ in postprandial autonomic and cortisol responses.

Objective: As the primary link between brain and gut, autonomic and endocrine dysfunction may play a role in the pathophysiology of the irritable bowel syndrome (IBS). The aim of this study was to assess autonomic, endocrine, and symptomatic responses to food intake in diarrhea-predominant and constipation-predominant IBS patients, compared to normals.

Methods: Twelve women with diarrhea-predominant or alternating IBS (IBS-D), 12 women with constipation predominant IBS (IBS-C), and 20 healthy women participated.

The circadian cycle: is the whole greater than the sum of its parts?

The term 'circadian rhythm' describes an oscillatory behavior in the absence of exogenous environmental cues, with a period of about a day. As yet, we don't fully understand which biological mechanisms join together to supply a stable and self-sustained oscillation with such a long period. By chipping away at the molecular mechanism with genetic approaches, some common features are emerging.

Circadian regulation of the light input pathway in Neurospora crassa.

FREQUENCY (FRQ) is a critical element of the circadian system of Neurospora. The white collar genes are important both for light reception and circadian function. We show that the responsiveness of the light input pathway is circadianly regulated.

Readiness to adopt adequate postural habits: an application of the Transtheoretical Model in the context of back pain prevention.

Based on a biomechanical model, an adequate body posture can contribute to the prevention of back pain and back pain chronicity. This study examines the explanatory value of the Transtheoretical Model (TTM) for the adoption of adequate postural habits in a cross-sectional sample of 149 employees of a German administration unit (mean age 40.2 years, 50% female).

Assessment of health-related quality-of-life in patients after heart transplantation under therapy with tacrolimus or cyclosporine.

Reduction of allograft rejections remains a primary goal for patients after orthotopic heart transplantation. In an open, multicentre, prospectively randomised, parallel group study, patients with primary orthotopic heart transplantation under oral immunosuppressive treatments with tacrolimus (FK506) or cyclosporine (sandimmun) were compared with respect to medical outcome data. As health-related quality-of-life (HRQOL) is also supposed to be an important outcome parameter, it was assessed as a secondary variable in these two patient groups.

Circadian clocks: Omnes viae Romam ducunt.

The circadian clock in all organisms is so intimately linked to light reception that it appears as if evolution has simply wired a timer into the mechanism that processes photic information. Several recent studies have provided new insights into the role of light input pathways in the circadian system of Arabidopsis.

Quality of life in patients before and after kidney transplantation.

Abstract The aim of the present study was to differentially determine quality of life (QOL) in patients with end-stage renal disease (ESRD) after successful kidney transplantation (RT, Group A) compared with ESRD patients on a waiting list for RT (Group B). and with healthy controls (Group C) because opinions vary as to which treatment modality can best assure ESRD patients a high QOL. Groups A, B and C each consisted of 149 persons, matched for age and gender.

The representation of articulation in the primary sensorimotor cortex.

Bilabial, alveolar and velar sounds are produced at different locations around the oral cavity. fMRI was used to localize cortical representation of articulation in seven healthy subjects during repetitive lip and vertical tongue movements as well as repetitive articulation of /pa/ (bilabial), /ta/ (alveolar), /ka/ (velar consonants) and a combination of all three in /pataka/. Centers of gravity (COG) analysis of fMRI activation in the primary motor (M1) and sensory cortex (S1) revealed /pa/- adjacent to lip representation and /ta/- articulation to tongue representation.

Conditioned suppression of contact sensitivity is independent of sympathetic splenic innervation.

The present study investigated the role of sympathetic innervation of the spleen in conditioned suppression of a contact hypersensitivity (CHS) reaction. Behavioral conditioning was achieved by pairing saccharin drinking solution (conditioned stimulus, CS) with injection of cyclosporin A (CsA, 20 mg/kg; unconditioned stimulus, UCS). Four days after sensitization of the animals by application of a 5% 2,4-dinitrochlorobenzene (DNCB) to abdominal skin, the animals were challenged by applying a 1% DNCB solution to the ear.

Methodological considerations in the assessment of gingival crevicular fluid volume.

In 4 studies on gingival crevicular fluid volume (GCFV) determination, the reliability of measurements, influences of plaque, circadian rhythms and stability over 24 h were examined. Samples were taken at 2 sites with a modified intracrevicular method. Reliability (n=40): repeated GCFV determinations within 5 min revealed good reliability coefficients (r(tt)>0.

Prolonged reduction of salivary immunoglobulin A (sIgA) after a major academic exam.

Objective: In a previous study we observed a continuous reduction of salivary IgA concentration ([sIgA]) during a period of academic stress. This reduction of sIgA concentration exceeded the stress period by at least 1 week. The present study aimed to replicate and extend our previous finding.

Pavlovian conditioning of immune function: animal investigation and the challenge of human application.

Pavlovian conditioning of immune functions provided early impetus to the rapidly expanding knowledge of bi-directional communication among the immune, endocrine, and central nervous systems. Since these early investigations, the phenomenology of this response has been well characterized. However the neural mechanisms and biological relevance of conditioned immunomodulation remain unclear.

After-effects of stress on crevicular interleukin-1beta.

Background: In a previous study, we found stress to increase crevicular interleukin-1beta (Il-1beta) secretion induced by supragingival plaque. While in that study, stress and plaque were presented concomitantly, we now wondered whether a consecutive presentation of these 2 factors would still exert stress effects.

Method: 39 medical students participated in the study; 18 took part in a major exam while the remaining 21 served as controls.

Circadian systems and metabolism.

Circadian systems direct many metabolic parameters and, at the same time, they appear to be exquisitely shielded from metabolic variations. Although the recent decade of circadian research has brought insights into how circadian periodicity may be generated at the molecular level, little is known about the relationship between this molecular feedback loop and metabolism both at the cellular and at the organismic level. In this theoretical paper, we conjecture about the interdependence between circadian rhythmicity and metabolism.