610 Medizin und Gesundheit
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Background: Common warts (verrucae vulgares) are human papilloma virus (HPV) infections with a high incidence and prevalence, most often affecting hands and feet, being able to impair quality of life. About 30 different therapeutic regimens described in literature reveal a lack of a single striking strategy. Recent publications showed positive results of photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) in the treatment of HPV-induced skin diseases, especially warts, using visible light (VIS) to stimulate an absorption band of endogenously formed protoporphyrin IX. Additional experiences adding waterfiltered infrared A (wIRA) during 5-ALA-PDT revealed positive effects. Aim of the study: First prospective randomised controlled blind study including PDT and wIRA in the treatment of recalcitrant common hand and foot warts. Comparison of "5-ALA cream (ALA) vs. placebo cream (PLC)" and "irradiation with visible light and wIRA (VIS+wIRA) vs. irradiation with visible light alone (VIS)". Methods: Pre-treatment with keratolysis (salicylic acid) and curettage. PDT treatment: topical application of 5-ALA (Medac) in "unguentum emulsificans aquosum" vs. placebo; irradiation: combination of VIS and a large amount of wIRA (Hydrosun® radiator type 501, 4 mm water cuvette, waterfiltered spectrum 590-1400 nm, contact-free, typically painless) vs. VIS alone. Post-treatment with retinoic acid ointment. One to three therapy cycles every 3 weeks. Main variable of interest: "Percent change of total wart area of each patient over the time" (18 weeks). Global judgement by patient and by physician and subjective rating of feeling/pain (visual analogue scales). 80 patients with therapy-resistant common hand and foot warts were assigned randomly into one of the four therapy groups with comparable numbers of warts at comparable sites in all groups. Results: The individual total wart area decreased during 18 weeks in group 1 (ALA+VIS+wIRA) and in group 2 (PLC+VIS+wIRA) significantly more than in both groups without wIRA (group 3 (ALA+VIS) and 4 (PLC+VIS)): medians and interquartile ranges: -94% (-100%/-84%) vs. -99% (-100%/-71%) vs. -47% (-75%/0%) vs. -73% (-92%/-27%). After 18 weeks the two groups with wIRA differed remarkably from the two groups without wIRA: 42% vs. 7% completely cured patients; 72% vs. 34% vanished warts. Global judgement by patient and by physician and subjective rating of feeling was much better in the two groups with wIRA than in the two groups without wIRA. Conclusions: The above described complete treatment scheme of hand and foot warts (keratolysis, curettage, PDT treatment, irradiation with VIS+wIRA, retinoic acid ointment; three therapy cycles every 3 weeks) proved to be effective. Within this treatment scheme wIRA as non-invasive and painless treatment modality revealed to be an important, effective factor, while photodynamic therapy with 5-ALA in the described form did not contribute recognisably - neither alone (without wIRA) nor in combination with wIRA - to a clinical improvement. For future treatment of warts an even improved scheme is proposed: one treatment cycle (keratolysis, curettage, wIRA, without PDT) once a week for six to nine weeks. © 2004 Fuchs et al; licensee German Medical Science. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL : http://www.egms.de/en/gms/volume2.shtml
Purpose: Medically recommended training often faces the dilemma that necessary mechanical intensities for muscle adaptations exceed patients' physical capacity. In this regard, blood flow restriction (BFR) training is becoming increasingly popular because it enables gains in muscle mass and strength despite using low-mechanical loads combined with external venous occlusion. Since the underlying mechanisms are still unknown, we applied invasive measurements during exercise with and without BFR to promote physiological understanding and safety of this popular training technique. Methods: In a randomized cross-over design, ten healthy men (28.1 ± 6.5 years) underwent two trials of unilateral biceps curls either with (BFR) and without BFR (CON). For analysis of changes in intravascular pressures, blood gases, oximetry and electrolytes, an arterial and a venous catheter were placed at the exercising arm before exercise. Arterial and venous blood gases and intravascular pressures were analyzed before, during and 5 min after exercise. Results: Intravascular pressures in the arterial and venous system were more increased during exercise with BFR compared to CON (p < 0.001). Furthermore, arterial and venous blood gas analyses revealed a BFR-induced metabolic acidosis (p < 0.05) with increased lactate production (p < 0.05) and associated elevations in [K+], [Ca2+] and [Na+] (p < 0.001). Conclusion: The present study describes for the first time the local physiological changes during BFR training. While BFR causes greater hypertension in the arterial and venous system of the exercising extremity, observed electrolyte shifts corroborate a local metabolic acidosis with concurrent rises in [K+] and [Na+]. Although BFR could be a promising new training concept for medical application, its execution is associated with comprehensive physiological challenges.
Background: Delayed-onset muscle soreness (DOMS) refers to dull pain and discomfort in people after participating in exercise, sport or recreational physical activities. The aim of this study was to detect underlying mechanical thresholds in an experimental model of DOMS.
Methods: Randomised study to detect mechanical pain thresholds in a randomised order following experimentally induced DOMS of the non-dominant arm in healthy participants. Main outcome was the detection of the pressure pain threshold (PPT), secondary thresholds included mechanical detection (MDT) and pain thresholds (MPT), pain intensity, pain perceptions and the maximum isometric voluntary force (MIVF).
Results: Twenty volunteers (9 female and 11 male, age 25.2 ± 3.2 years, weight 70.5 ± 10.8 kg, height 177.4 ± 9.4 cm) participated in the study. DOMS reduced the PPT (at baseline 5.9 ± 0.4 kg/cm2) by a maximum of 1.5 ± 1.4 kg/cm2 (-24%) at 48 hours (p < 0.001). This correlated with the decrease in MIVF (r = -0.48, p = 0.033). Whereas subjective pain was an indicator of the early 48 hours, the PPT was still present after 72 hours (r = 0.48, p = 0.036). Other mechanical thresholds altered significantly due to DOMS, but did show no clinically or physiologically remarkable changes.
Conclusions: Functional impairment following DOMS seems related to the increased excitability of high-threshold mechanosensitive nociceptors. The PPT was the most valid mechanical threshold to quantify the extent of dysfunction. Thus PPT rather than pain intensity should be considered a possible marker indicating the athletes’ potential risk of injury.
BACKGROUND: hysical activity exerts a variety of long-term health benefits in older adults. In particular, it is assumed to be a protective factor against cognitive decline and dementia.
METHODS/DESIGN: Randomised controlled assessor blinded 2-armed trial (n = 60) to explore the exercise- induced neuroprotective and metabolic effects on the brain in cognitively healthy older adults. Participants (age ≥ 65), recruited within the setting of assisted living facilities and newspaper advertisements are allocated to a 12-week individualised aerobic exercise programme intervention or a 12-week waiting control group. Total follow-up is 24 weeks. The main outcome is the change in cerebral metabolism as assessed with Magnetic Resonance Spectroscopic Imaging reflecting changes of cerebral N-acetyl-aspartate and of markers of neuronal energy reserve. Imaging also measures changes in cortical grey matter volume. Secondary outcomes include a broad range of psychometric (cognition) and movement-related parameters such as nutrition, history of physical activity, history of pain and functional diagnostics. Participants are allocated to either the intervention or control group using a computer-generated randomisation sequence. The exercise physiologist in charge of training opens sealed and opaque envelopes and informs participants about group allocation. For organisational reasons, he schedules the participants for upcoming assessments and exercise in groups of five. All assessors and study personal other than exercise physiologists are blinded.
DISCUSSION: Magnetic Resonance Spectroscopic Imaging gives a deeper insight into mechanisms of exercise-induced changes in brain metabolism. As follow-up lasts for 6 months, this study is able to explore the mid-term cerebral metabolic effects of physical activity assuming that an individually tailored aerobic ergometer training has the potential to counteract brain ageing.
NCT02343029 (clinicaltrials.gov; 12 January 2015).
Background: The focus of this case report is on the role of inflammation as a contributor to pain in plantar fasciitis and its cure by the injection of local anesthetics.
Case presentation: This is a case report on a 24-year-old white man, a middle-distance runner, with chronic unilateral plantar fasciitis and perceived heel pain for almost 1.5 years. He was treated with neural therapy (that is, injection of < 1 ml procaine 1% which is a local anesthetic with strong anti-inflammatory properties) of the surgical scar and along the surgical puncture channel. The follow-up period from the time of first presentation until publication was 2.5 years. At admission, pain intensity (visual analog scale) in the affected leg was severe (10 cm, visual analog scale; range 0–10 cm) when walking and moderate (5 cm, visual analog scale) when standing. After the first session of injections he could stand pain-free and pain when walking was markedly reduced (− 90%). After the third session, he reported no pain in the affected leg and could return to sports at his former level (no difference in training load compared to non-injured state). There was no recurrence of inflammatory signs or heel pain despite intense athletics training up to the date of publication.
Conclusions: In prolonged cases of plantar fasciitis, inflammation is an important component in the development of persistent pain. The results of our case describe the effects of three neural therapy sessions that abolished inflammation and associated heel pain. Neural therapy might be an effective and time-efficient approach in the treatment of plantar fasciitis, enabling an early return to sports.
In the publication of this article, there are reference errors in four positions the respective references are missing since reference Fischer was omitted. In addition for reference Egli et al. the in text citation only appeared at the end of the paragraph, but not following important statements. This has now been included in this correction. ...
Effects of single-point acupuncture (HT7) in the prevention of test anxiety : results of a RCT
(2018)
Background: The number of students using neuro enhancement to improve their performance and to prevent test anxiety is increasing. The acupuncture point Heart 7 (HT7) has been described as being prominent in reducing states of anxiety.
Methods: We conducted a randomized placebo-controlled, two-armed pilot trial to investigate the efficacy of a single-point acupuncture treatment at bilateral HT7 compared to sham laser acupuncture on test anxiety. Test anxiety was induced applying the standardised protocol of the Trier Social Stress Test. Outcome measures included saliva samples analysed for cortisol and amylase, anxiety questionnaires and heart rate variability.
Results: Twenty-five male subjects (age 28 ± 5 years) were allocated to either verum acupuncture (n = 12) or sham laser acupuncture (n = 13). Cortisol peaked 20 min after the stress test (2-fold, 18.11 ± 2 nmol/l) and amylase 10 min after (2-fold, 259 ± 49 U/ml) with no difference between groups. There were no differences between groups regarding either anxiety questionnaires or physiological parameters. Compared to reference data (3-fold increase in cortisol), increase in stress hormones and heart rate seemed somewhat reduced.
Conclusions: Acupuncture may be a possible approach for the treatment of anxiety. Due to the lack of a no control treatment group, we cannot determine the magnitude of possible specific needle effects at HT7 to promote specific effects in the neuroendocrine system. Finally this study only examines the efficacy of a single time treatment.
Welche gesellschaftlichen Zwänge wirken auf die Medizin und ihre Anwender ein? Wie ist das Verhältnis von Ökonomie und medizinisch Gebotenem? Wie steht es mit der Finanzierung der nicht evidenzbasierten Behandlung? Stellen Rationierung und Rationalisierung die möglichen Prinzipien der Priorisierung dar? Führt die Priorisierung zur Qualitätsminderung oder gar Sorgfaltsverletzung? Diese Fragen behandelte der 4. Ärztetag am Dom in Frankfurt am Main. ...
Background: The positive association between parental socio-economic position (PSEP) and health among adolescents may be partly explained by physical activity behaviour. We investigated the associations between physical activity, aerobic fitness and PSEP in a population based sample of German adolescents.
Methods: 5,251 participants, aged 11-17 years, in the German Health Interview and Examination Survey for Children and Adolescents 2003-2006 (KiGGS) underwent a sub-maximal cycle ergometer test and completed a questionnaire obtaining information on physical activity and media use. The associations between physical activity, media use, aerobic fitness and PSEP were analysed with multivariate logistic regression models for boys and girls separately. Odds ratios (ORs) of PSEP (education, occupation and income) on the outcomes were calculated adjusted for age, region, and other influencing factors.
Results: Parental education was more strongly associated with the outcome variables than parental occupation and income. After adjusting for age and region, a higher parental education level was associated with better aerobic fitness - with an OR of 1.5 (95% CI 1.2-1.9) for girls whose parents had secondary education and 1.9 (1.4-2.5) for girls whose parents had tertiary education compared to girls whose parents had primary education. The corresponding ORs for boys were 1.3 (1.0-1.6) and 1.6 (1.2-2.1), respectively. Higher parental education level was associated with lower media use: an OR of 2.1 (1.5-3.0) for girls whose parents had secondary education and 2.7 (1.8-4.1) for girls whose parents had primary education compared to girls whose parents had tertiary education. The corresponding ORs for boys were 1.5 (1.2-1.9) and 1.9 (1.5-2.5), respectively. Higher parental education level was associated with a higher physical activity level only among girls: an OR of 1.3 (1.0-1.6) for girls whose parents had secondary education and 1.2 (0.9-1.5) for girls whose parents had tertiary education compared to girls whose parents had primary education. The corresponding ORs for boys were 0.9 (0.8-1.2) and 0.8 (0.6-1.0), respectively.
Conclusions: Adolescents of parents with low SEP showed a lower level of aerobic fitness and higher levels of media use than adolescents of parents with higher SEP. Health-promotion interventions need to reach adolescents of parents with low PSEP and stimulate physical activity.
The central portion of chronic wounds is often hypoxic and relatively hypothermic, representing a deficient energy supply of the tissue, which impedes wound healing or even makes it impossible. Water-filtered infrared-A (wIRA) is a special form of heat radiation with a high tissue penetration and a low thermal load to the skin surface. wIRA produces a therapeutically usable field of heat and increases temperature, oxygen partial pressure and perfusion of the tissue. These three factors are decisive for a sufficient tissue supply with energy and oxygen and consequently as well for wound healing, especially in chronic wounds, and infection defense. wIRA acts both by thermal and thermic as well as by non-thermal and non-thermic effects. wIRA can advance wound healing or improve an impaired wound healing process and can especially enable wound healing in non-healing chronic wounds. wIRA can considerably alleviate the pain and diminish wound exudation and inflammation and can show positive immunomodulatory effects.
In a prospective, randomized, controlled study of 40 patients with chronic venous stasis ulcers of the lower legs irradiation with wIRA and visible light (VIS) accelerated the wound healing process (on average 18 vs. 42 days until complete wound closure, residual ulcer area after 42 days 0.4 cm² vs. 2.8 cm²) and led to a reduction of the required dose of pain medication in comparison to the control group of patients treated with the same standard care (wound cleansing, wound dressing with antibacterial gauze, and compression garment therapy) without the concomitant irradiation.
Another prospective study of 10 patients with non-healing chronic venous stasis ulcers of the lower legs included extensive thermographic investigation. Therapy with wIRA(+VIS) resulted in a complete or almost complete wound healing in 7 patients and a marked reduction of the ulcer size in another 2 of the 10 patients, a clear reduction of pain and required dose of pain medication, and a normalization of the thermographic image.
In a current prospective, randomized, controlled, blinded study patients with non-healing chronic venous stasis ulcers of the lower legs are treated with compression garment therapy, wound cleansing, wound dressings and 30 minutes irradiation five times per week over 9 weeks. A preliminary analysis of the first 23 patients of this study has shown in the group with wIRA(+VIS) compared to a control group with VIS an advanced wound healing, an improved granulation and in the later phase of treatment a decrease of the bacterial burden.
Some case reports have demonstrated that wIRA can also be used for mixed arterial-venous ulcers or arterial ulcers, if irradiation intensity is chosen appropriately low and if irradiation is monitored carefully. wIRA can be used concerning decubital ulcers both in a preventive and in a therapeutic indication. wIRA can improve the resorption of topically applied substances also on wounds.
An irradiation with VIS and wIRA presumably acts with endogenous protoporphyrin IX (or protoporphyrin IX of bacteria) virtually similar as a mild photodynamic therapy (endogenous PDT-like effect). This could lead to improved cell regeneration and wound healing and to antibacterial effects.
In conclusion, these results indicate that wIRA generally should be considered for the treatment of chronic wounds.
The attention control video has been frequently applied to test the ego depletion effect. However, its validity has never been tested, a shortcoming we address in this preregistered study. In the first task, self-control strength was temporarily depleted in the depletion condition (n = 56) but remained intact in the control condition (n = 56). The attention control video served as the secondary task, and we assumed that the depletion condition would perform significantly worse compared to the control condition. Attention regulation was measured with an eye-tracking device. The results revealed that the gaze behavior in the two conditions differed statistically significantly; however, the actual difference was small, indicating that the attention control video may not be an optimal measure of self-control.
Background: Despite the numerous associations of vitamin D with health and disease, vitamin D deficiency is still common from a global perspective. While basic research, clinical and preventive activities grow constantly in vitamin D research, there is no in-depth analysis of the related global scientific productivity available so far.
Methods: Density equalizing mapping procedures (DEMP) were combined with socioeconomic benchmarks using the NewQIS platform.
Results: A total of 25,992 vitamin D-related research articles were identified between 1900 to 2014 with a significant increase (r2 = .6541) from 1900 to 2014. Authors located in Northern America – especially in the USA – distributed the majority of global vitamin D research, followed by their Western European counterparts. DEMP-analysis illustrates that Africa and South America exhibit only minor scientific productivity. Among high-income group countries, Scandinavian nations such as Denmark or Finland (2147.9 and 1607.7 vitamin D articles per GDP in 1000 billion USD) were highly active with regard to socioeconomic figures.
Conclusion: Networks dedicated to vitamin D research are present around the world. Overall, the Northern American and Western European nations occupy prominent positions. However, South American, African and Asian countries apart from Japan only play a minor role in the global research production related to vitamin D. Since vitamin D deficiency is currently increasing in the Americas, Europe and parts of the Middle East, research in these regions may need to be encouraged.
Exercise is a treatment option in peripheral artery disease (PAD) patients to improve their clinical trajectory, at least in part induced by collateral growth. The ligation of the femoral artery (FAL) in mice is an established model to induce arteriogenesis. We intended to develop an animal model to stimulate collateral growth in mice through exercise. The training intensity assessment consisted of comparing two different training regimens in C57BL/6 mice, a treadmill implementing forced exercise and a free-to-access voluntary running wheel. The mice in the latter group covered a much greater distance than the former pre- and postoperatively. C57BL/6 mice and hypercholesterolemic ApoE-deficient (ApoE-/-) mice were subjected to FAL and had either access to a running wheel or were kept in motion-restricting cages (control) and hind limb perfusion was measured pre- and postoperatively at various times. Perfusion recovery in C57BL/6 mice was similar between the groups. In contrast, ApoE-/- mice showed significant differences between training and control 7 d postoperatively with a significant increase in pericollateral macrophages while the collateral diameter did not differ between training and control groups 21 d after surgery. ApoE-/- mice with running wheel training is a suitable model to simulate exercise induced collateral growth in PAD. This experimental set-up may provide a model for investigating molecular training effects.
Historisch betrachtet wurde Krebspatienten durch das behandelnde Personal von physischer Belastungen oftmals abgeraten (Steins Bisschop et al., 2012). Mit der zunehmenden Zahl an Publikationen im Bereich onkologischer Rehabilitation wird deutlich, dass Krebspatienten oftmals eine stark reduzierte kardiorespiratorische Leistungsfähigkeit aufweisen, was wiederum Implikationen für akute wie auch längerfristige krebs-assoziierte Effekte und Outcomes haben kann (Jones et al., 2008). Somit steht dem bisherigen Verhaltens-Dogma der Ruhe und Schonung bei Krebspatienten eine Vielzahl an Evidenz der Effektivität und Notwendigkeit von regelmäßiger körperlicher Bewegung gegenüber (Jones et al., 2008; Klika et al., 2009; Steins Bisschop et al., 2012). Diese Arbeiten bieten fundierte Informationen bezüglich der zu Grunde liegenden Limitationen der Belastungstoleranz. Darauf aufbauend wird dieses Wissen genutzt, um effektive Trainings- und Rehabilitationsprogramme zu entwerfen sowie klinische Resultate zu verbessern (Jones et al., 2009).
Strukturierte und individualisierte Sport- und Bewegungstherapie gilt dabei als ein vielversprechender Ansatz, die nachlassende Fähigkeit der selbständigen Alltagsbewältigung, die krebsassoziierte Müdigkeitssymptomatik (fatigue), aber auch die allgemeine kardiorespiratorische Fitness (KRF) zu verbessern (Schmitz et al., 2010). Für onkologische Patienten von ebenso großer Bedeutung ist die Tatsache, dass durch regelmäßige körperliche Aktivität Begleiterscheinungen der eingesetzten Behandlungsmethoden (Hayes et al., 2009), das psychische Wohlbefinden als auch die Gesamtmortalität positiv beeinflusst werden können (Mishra et al., 2012b; Mishra et al., 2012a). Zusätzlich verspricht regelmäßige körperliche Bewegung, den Funktionsverlust in den drei wichtigsten physiologischen Bereichen (Muskulatur, Herz-Kreislauf-System und kardiopulmonales System) zu verringern oder sogar aufzuhalten (Hayes et al., 2009). Demzufolge nimmt die sporttherapeutische Sekundär- und Tertiärprävention bei Krebserkrankungen eine wichtige Rolle ein, und die Frage nach einer effektiven und zielgerichteten Belastungs- und Trainingssteuerung auf Basis valider und reliabler Messgrößen der körperlichen Leistungsfähigkeit gewinnt zunehmend an Bedeutung (Ulrich et al., 2013; Kirkham et al., 2013).
Aktuelle Empfehlungen zu körperlicher Aktivität bei onkologischen Patienten orientieren sich hinsichtlich der Ausgestaltung in punkto Häufigkeit, Umfang und Intensität im Allgemeinen an Bewegungs-Leitlinien für gesunde Gleichaltrige ohne chronische Erkrankungen. Eine Besonderheit bei onkologischen Patienten stellt jedoch oftmals die Berücksichtigung therapieassoziierter bzw. krankheitsbedingter Nebenwirkungen in der praktischen Umsetzung der Empfehlungen dar. Aktuelle Leitlinien sehen dafür ein aerobes Ausdauertraining an mindestens 3-5 Tagen/Woche bei einem Intensitätsspektrum moderater (150min) oder intensiver (75min) Beanspruchung (MVPA) bei 46-90% der maximalen Sauerstoffaufnahmefähigkeit vor.
Die in der Literatur beschriebenen Probleme einer Vielzahl an Verfahren zur Bestimmung der KRF und der darauf basierenden Ableitung von individualisierten Trainingsempfehlungen haben in den letzten Jahren vermehrt zu Ansätzen basierend auf der individuell physiologischen Belastungsreaktion in der Ausdauertrainingssteuerung und –bewertung geführt (Meyer et al., 2005c; Bentley et al., 2007b; Binder et al., 2008; Hofmann & Tschakert, 2011). Dabei kommen vor allem die in der sportmedizinischen Ausdauerleistungsdiagnostik etablierten Verfahren der Laktat-Leistungsdiagnostik und der spiroergometrischen Ermittlung ventilatorischer Schwellen zum Einsatz.
Kernziel der vorliegenden Arbeit war daher die Untersuchung von Leistungskennwerten an submaximalen Variablen aus Spiroergometrie und der Laktatdiagnostik im Kollektiv der onkologischen Patienten mit unterschiedlichen Krebsentitäten.
Das folgende Kapitel 2 fasst den aktuellen Forschungsstand zu Epidemiologie, Prävalenz sowie die Auswirkungen onkologischer Erkrankungen auf Aspekte der körperlichen Ausdauerleistungsfähigkeit und deren Diagnostik in der Sportmedizin zusammen. Resultierend aus dem Forschungsstand werden daraufhin Zielstellung und –fragen der vorliegenden Arbeit formuliert. Kapitel 4 umfasst die methodische Ablaufbeschreibung des Studiendesigns, die Probandenrekrutierung und -stichprobe, die eingesetzten diagnostischen Messverfahren, sowie die Darstellung der statistischen Auswertung. Nachfolgend auf die Darstellung der Ergebnisse in Kapitel 5 werden diese in Kapitel 6 vor dem Hintergrund des dargestellten Forschungstandes und aktueller relevanter Literatur diskutiert. Abschließend erfolgt eine Praxis-orientierte kritische Beleuchtung der Arbeit sowie ein eine perspektivische Einordnung der Ergebnisse mit Ausblick auf zukünftige Forschungsarbeiten.
Application of blood flow restriction to optimize exercise countermeasures for human space flight
(2019)
In recent years there has been a strong increase in publications on blood flow restriction (BFR) training. In particular, the fact that this type of training requires only low resistance to induce muscle strength and mass gains, makes BFR training interesting for athletes and scientists alike. For the same reason this type of training is particularly interesting for astronauts working out in space. Lower resistance during training would have the advantage of reducing the risk of strain-induced injuries. Furthermore, strength training with lower resistances would have implications for the equipment required for training under microgravity conditions, as significantly lower resistances have to be provided by the training machines. Even though we are only about to understand the effects of blood flow restriction on exercise types other than low-intensity strength training, the available data indicate that BFR of leg muscles is also able to improve the training effects of walking or running at slow speeds. The underlying mechanisms of BFR-induced functional and structural adaptations are still unclear. An essential aspect seems to be the premature fatigue of Type-I muscle fibers, which requires premature recruitment of Type-II muscle fibers to maintain a given force output. Other theories assume that cell swelling, anabolic hormones, myokines and reactive oxygen species are involved in the mediation of BFR training-related effects. This review article is intended to summarize the main advantages and disadvantages, but also the potential risks of such training for astronauts.
In Deutschland sind 15 Prozent der Kinder und Jugendlichen zwischen drei und 17 Jahren übergewichtig, über 6 Prozent leiden an Adipositas, krankhafter Fettleibigkeit mit schweren gesundheitlichen Folgen. Diese vom Robert-Koch-Institut im vergangenen Jahr ermittelten Zahlen decken sich mit unseren eigenen Untersuchungen an 11- bis 15-Jährigen in sechs hessischen Schulen. Zudem zeichnet sich ab, dass die Zahl der Übergewichtigen bei den Jugendlichen besonders ansteigt: Innerhalb der vergangenen 20 Jahre hat sich der Anteil adipöser 14- bis 17-Jähriger verdreifacht, Tendenz weiter steigend. Dies ist umso besorgniserregender, da mindestens 70 Prozent dieser Jugendlichen nicht wieder abspecken und als Erwachsene gesundheitlich schwer beeinträchtigt sind. Immerhin sind in Europa jährlich etwa eine Millionen Sterbefälle auf Folgen des Übergewichts zurückzuführen, was allein die deutsche Volkswirtschaft mit 15 Milliarden Euro im Jahr belastet. Übergewicht ist auch ein soziales Problem: Kinder aus sozial schwachen Familien und mit Migrationshintergrund tragen ein erheblich höheres Risiko. Wie unsere Erhebungen weiter vermuten lassen, sind vor allem solche Kinder betroffen, deren Eltern ebenfalls unter Übergewicht oder Adipositas leiden. Fettleibige Kinder fühlen sich oft ausgegrenzt und sozial stigmatisiert. Dies beeinträchtigt ihre psychosoziale Entwicklung erheblich. Mehr als die Hälfte der von uns befragten übergewichtigen Schulkinder fühlen sich unwohl und möchten ihr Gewicht unbedingt reduzieren. ...
Jährlich erkranken etwa 425 000 Menschen in Deutschland an Krebs. Die Tendenz ist steigend: Experten gehen davon aus, dass die Zahl der Neuerkrankungen bis zum Jahr 2030 um 50 Prozent zunehmen wird. Doch zu dieser schlechten Nachricht gibt es auch eine gute: Körperliche Aktivität und Sport können das allgemeine Risiko, an bestimmten Krebsformen zu erkranken, vermindern. Dazu zählen vor allem Darmkrebs sowie der nach den Wechseljahren auftretende Brust- und Gebärmutterschleimhautkrebs. Aber auch wer schon erkrankt ist, kann sein Wohlbefinden und Selbstvertrauen durch spezielle Bewegungsprogramme, wie sie an der Goethe-Universität entwickelt werden, steigern. Selbst die Leiden von Patienten mit fortgeschrittenen Krebserkrankungen lassen sich auf diese Weise lindern. Denn Bewegung beeinflusst nicht nur die unmittelbar tumorbedingten Symptome, sondern auch therapiebedingte Nebenwirkungen, insbesondere die der Chemotherapie.
Cognitive flexibility and cognitive stability : neural and behavioral correlates in men and mice
(2014)
The ability to flexibly adjust behavior according to a changing environment is crucial to ensure a species' survival. However, the successful pursuit of goals also requires the stable maintenance of behavior in the face of potential distractors. Thus, cognitive flexibility and cognitive stability are important processes for the cognitive control of behavior. There is a large body of behavioral and neuroimaging research concerning cognitive control in general, but also specifically on cognitive flexibility and cognitive stability, albeit most often assessed in separate task paradigms. Nevertheless, whether cognitive flexibility and cognitive stability depend upon separate or shared neuronal bases is still a matter of debate. Complementing empirical research, computational models have become an important strategy in neuroscientific research, as they have the potential of providing mechanistic explanations of empirical observations, for example by allowing for the direct manipulation of molecular parameters in simulated neural networks. The computational model underlying the so-called Dual-State Theory contains specific hypotheses with respect to cognitive flexibility and cognitive stability. The neural networks simulated by this model exhibit multiple stable firing states, i.e., the neural network can maintain a high firing state also without continuing external input due to a network architecture consisting of recurrently connected neurons. Transitions between such network states, also called attractor states, can be induced by external input, and represent working memory contents or active task rules. Simulations showed that the stability of these attractor states, and thus of task rule representations, depend on the dopamine state of the system and can consequently vary between persons. The Dual-State Theory predicts an antagonistic relationship between cognitive flexibility and cognitive stability, as robust attractor states would facilitate the inhibition of distractors, but impair efficient task switching, while rather unstable attractor states would promote efficient transitions between representations but would also come at the cost of increased distractibility.
Based on the Dual-State Theory, a task paradigm was designed allowing for the simultaneous assessment of cognitive flexibility, in the sense of rule-based task switching, and cognitive stability, in the sense of inhibiting irrelevant distractors. Furthermore, a behavioral measure was developed to assess the individual attractor state stability, named spontaneous switching rate (SSR). In the first study of this work, this paradigm was tested in a sample of healthy human subjects using functional magnetic resonance imaging (fMRI). An overlapping fronto-parietal network was activated for both cognitive flexibility and cognitive stability. Furthermore, behavioral as well as neuroimaging results are in favor of an antagonistic relationship between cognitive flexibility and cognitive stability. A specific prefrontal region, the inferior frontal junction (IFJ), was implied to potentially contain the relevant neural networks mediating the transitions between attractor states, i.e., task rule representations, as its activity was modulated by the SSR such that persons with rather unstable attractor states activated it less during task switching while showing better performance. Most importantly, functional connectivity of the IFJ was antagonistically modulated by the SSR: more flexible persons connected it less to another prefrontal area during task switching, while showing higher functional connectivity during distractor inhibition.
In a second study, a larger human sample was assessed and further hypotheses derived from the Dual-State Theory on variability of neural processing were tested: we hypothesized that persons with high brain signal variability should have less stable network states and thus benefit on tasks requiring cognitive flexibility but suffer from it when the task requires a higher degree of cognitive stability. Furthermore, recent fMRI-research on brain signal variability revealed beneficial effects of higher brain signal variability on cognitive performance in general. Using a novel customized analysis pipeline to measure trial-to-trial fMRI-signal variability, we indeed found differential effects of brain signal variability: higher levels of brain signal variability were found to be beneficial for effectiveness, i.e., performance in terms of error rates, for both cognitive flexibility and stability. However, brain signal variability impaired the efficiency in terms of response times of inhibiting distractors, i.e., cognitive stability.
Due to further predictions of the Dual-State Theory concerning schizophrenia and the dopaminergic system, it was considered valuable to pursue a translational approach and thus allowing for the employment of animal models of psychiatric diseases. Consequently, in a first step the human paradigm was translated for a murine population using an innovative touchscreen approach. Results showed analogous behavioral effects in wildtype mice as before in healthy humans: the antagonistic relation between cognitive flexibility and cognitive stability was replicated and also for mice, a behavioral measure for the individual attractor stability was established and validated, named the individual spontaneous switching score.
To conclude, we established a novel paradigm assessing both cognitive flexibility and stability simultaneously showing an antagonistic relationship between these two cognitive functions on the behavioral level in two different species, which supports predictions from the Dual-State Theory. This was further underlined by evidence on the activation, functional connectivity and signal variability level in the human brain.
Einleitung: Analysen kinematischer und elektromyographischer Daten verwenden häufig zeit-diskrete Werte. Bewegungen und EMGs sind jedoch zeitkontinuierliche Größen. Ziel der Arbeit ist eine verlaufsorien-tierte Analyse von Kinematik und EMG mit der Fragestellung, ob Unter-schiede innerhalb und zwischen den gesunden und operierten Proban-den bestehen. Methodik: Untersucht wurden 21 Patienten nach Hüft-TEP-Operation (43-71 Jahre) und 12 vergleichbare gesunde Probanden (KG). Dazu wurden beim Gehen auf dem Laufband bei frei wählbarer Geschwindigkeit die kinematischen Merkmale der Beckenbewegung und bilateral die EMGs des M. gluteus medius registriert. Mittels ortho-gonaler Referenzfunktionen wurden die Merkmalszeitverläufe einzelner Schritte auf Matrizen abgebildet und anschließend mit Hilfe eines Ähn-lichkeitsmaßes und einer Clusteranalyse untersucht. Ergebnisse: Indi-viduelle Gangmuster konnten in der vorliegenden Arbeit sowohl durch Analyse der kinematischen Daten als auch der EMGs erkannt werden. Es wurden jedoch keine einheitlichen Muster in der Patientengruppe festgestellt, obgleich verschiedene Gruppierungen zu finden waren, die jedoch anhand der erhobenen Patientendaten und Fragebogenscores nur eingeschränkt nachvollzogen werden konnten. Schlussfolgerung: Mit der verwendeten verlaufsorientierten multivariaten Analysemethode konnten intraindividuelle Ähnlichkeiten deutlich besser aufgefunden werden als interindividuelle Ähnlichkeiten, falls durch einen krankheits-spezifischen Anpassungsprozess vorhanden. Die Individualität ist somit dominierend.