Stress fracture of bilateral tibial metaphysis due to ceremonial march training: a case report

Stress fractures are caused by repetitive microtraumas that occur during unusual or increased activities. Clinical suspicion is essential for the diagnosis. A twenty-years old soldier was presented with bilateral knee pain and restriction of knee movements after a period of training for ceremonial march. Although plain X-rays were normal, scintigraphy and MRI revealed stress fractures at metaphyseal region of both tibias. History of a patient presenting with persisting joint or bone pain after an unusual repetitive activity should be delicately inquired. Typical history, although pain might be localized to unusual sites, should raise the suspicion of a stress fracture

From bit to it: How a complex metabolic network transforms information into living matter

Organisms live and die by the amount of information they acquire about their environment. The systems analysis of complex metabolic networks allows us to ask how such information translates into fitness. A metabolic network transforms nutrients into biomass. The better it uses information on available nutrient availability, the faster it will allow a cell to divide. I here use metabolic flux balance analysis to show that the accuracy I (in bits) with which a yeast cell can sense a limiting nutrient's availability relates logarithmically to fitness as indicated by biomass yield and cell division rate. For microbes like yeast, natural selection can resolve fitness differences of genetic variants smaller than 10-6, meaning that cells would need to estimate nutrient concentrations to very high accuracy (greater than 22 bits) to ensure optimal growth. I argue that such accuracies are not achievable in practice. Natural selection may thus face fundamental limitations in maximizing the information processing capacity of cells. The analysis of metabolic networks opens a door to understanding cellular biology from a quantitative, information-theoretic perspective

Influenza vaccination coverage rates in five European countries during season 2006/07 and trends over six consecutive seasons

<p>Abstract</p> <p>Background</p> <p>The objectives of the survey were to identify the level of influenza vaccination coverage in five European countries between 2001 and 2007, to understand the drivers and barriers to vaccination, to assess vaccination intentions for the winter 2007/08 as well as major encouraging factors for vaccination.</p> <p>Methods</p> <p>Between 2001 and 2007, representative household surveys were performed with telephone or mailed (France) interviews of individuals aged 14 and above. The questionnaire used in the UK, Germany, Italy, France and Spain was essentially the same in all seasons. The data were subsequently pooled. Four target groups were defined for the analysis: 1) persons aged 65 years and over; 2) persons working in the medical field; 3) chronically ill persons and 4) combined target group composed of individuals belonging to one or more of the previous groups 1, 2 or 3.</p> <p>Results</p> <p>In 2006/07, vaccination coverage was, 25.0% in UK, 27.4% in Germany, 21.8% in Spain, 24.2% in France and 24.4% in Italy. During six influenza seasons (2001–2007), vaccination coverage showed a slight positive trend in the five countries (p ≤ 0.0001). In the elderly (≥ 65 years), across all countries, no significant trend was seen; the vaccination rate decreased non-significantly from a peak of 64.2% in season 2005/06 to 61.1% in season 2006/07. The most frequent reason for getting vaccinated was a recommendation by the family doctor or nurse (51%), and this was also perceived as the major encouraging factor for vaccination (61%). The main reason for not getting vaccinated was feeling unlikely to catch the flu (36%).</p> <p>Conclusion</p> <p>In the UK, Germany and Spain, influenza vaccination coverage rates in season 2006/07 dropped slightly compared to the previous season. However, a trend of increasing vaccination coverage was observed from 2001/02 to 2006/07 across Europe. The family doctor is the major source of encouragement for individuals getting vaccinated. Efforts to overcome the barriers to vaccination need to be put in place to reach the WHO objective of 75% coverage in the elderly by 2010. This is a major challenge to be faced by governments, healthcare workers and healthcare organisations.</p

The Intermediate Filament Network in Cultured Human Keratinocytes Is Remarkably Extensible and Resilient

The prevailing model of the mechanical function of intermediate filaments in cells assumes that these 10 nm diameter filaments make up networks that behave as entropic gels, with individual intermediate filaments never experiencing direct loading in tension. However, recent work has shown that single intermediate filaments and bundles are remarkably extensible and elastic in vitro, and therefore well-suited to bearing tensional loads. Here we tested the hypothesis that the intermediate filament network in keratinocytes is extensible and elastic as predicted by the available in vitro data. To do this, we monitored the morphology of fluorescently-tagged intermediate filament networks in cultured human keratinocytes as they were subjected to uniaxial cell strains as high as 133%. We found that keratinocytes not only survived these high strains, but their intermediate filament networks sustained only minor damage at cell strains as high as 100%. Electron microscopy of stretched cells suggests that intermediate filaments are straightened at high cell strains, and therefore likely to be loaded in tension. Furthermore, the buckling behavior of intermediate filament bundles in cells after stretching is consistent with the emerging view that intermediate filaments are far less stiff than the two other major cytoskeletal components F-actin and microtubules. These insights into the mechanical behavior of keratinocytes and the cytokeratin network provide important baseline information for current attempts to understand the biophysical basis of genetic diseases caused by mutations in intermediate filament genes

Psychological Functioning and Disease-Related Quality of Life in Pediatric Patients With an Implantable Cardioverter Defibrillator

The objective of this multicenter study was to evaluate psychological functioning and disease-related quality of life (DRQoL) in pediatric patients with an implantable cardioverter defibrillator (ICD) in The Netherlands. Thirty patients were investigated; the mean age was 16.3 years, and the mean duration of implantation was 3.6 years. To assess psychological problems, three domains of the Symptom Checklist (SCL-90-R) were administered to the 25 patients >13 years old. DRQoL was assessed with a disease-specific pediatric questionnaire, the short-form 11-item Worries About (WA)ICDs Scale. Patients ≥13 years old scored significantly higher than the reference group on the domains of anxiety, depression, and sleeping problems of the SCL-90-R (T = 7.5, p < 0.001; T = 5.4, p < 0.001; and T = 7.8, p < 0.001, respectively). Patients who had received an (in)appropriate shock reported more depressive symptoms (T = 2.1, p < 0.03). Patients with >2 years implant duration (N = 19) or who had received an (in)appropriate shock (N = 13) showed lower DRQoL scores on the modified WAICD (T = 2.1, p < 0.04; T = 2.1, p < 0.5, respectively). Age at implantation or underlying disease did not influence psychological problems or DRQoL. Young ICD patients showed more anxiety, depression, and sleeping disorders. Worries were increased among patients with ICD shocks and in those who had their ICD implanted for >2 years. To determine psychological problems and help children to learn to cope with shocks, proper guidance and monitoring of young ICD patients are recommended

Biphasic Electrical Currents Stimulation Promotes both Proliferation and Differentiation of Fetal Neural Stem Cells

The use of non-chemical methods to differentiate stem cells has attracted researchers from multiple disciplines, including the engineering and the biomedical fields. No doubt, growth factor based methods are still the most dominant of achieving some level of proliferation and differentiation control - however, chemical based methods are still limited by the quality, source, and amount of the utilized reagents. Well-defined non-chemical methods to differentiate stem cells allow stem cell scientists to control stem cell biology by precisely administering the pre-defined parameters, whether they are structural cues, substrate stiffness, or in the form of current flow. We have developed a culture system that allows normal stem cell growth and the option of applying continuous and defined levels of electric current to alter the cell biology of growing cells. This biphasic current stimulator chip employing ITO electrodes generates both positive and negative currents in the same culture chamber without affecting surface chemistry. We found that biphasic electrical currents (BECs) significantly increased the proliferation of fetal neural stem cells (NSCs). Furthermore, BECs also promoted the differentiation of fetal NSCs into neuronal cells, as assessed using immunocytochemistry. Our results clearly show that BECs promote both the proliferation and neuronal differentiation of fetal NSCs. It may apply to the development of strategies that employ NSCs in the treatment of various neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases

Biphasic Electrical Currents Stimulation Promotes both Proliferation and Differentiation of Fetal Neural Stem Cells

The use of non-chemical methods to differentiate stem cells has attracted researchers from multiple disciplines, including the engineering and the biomedical fields. No doubt, growth factor based methods are still the most dominant of achieving some level of proliferation and differentiation control - however, chemical based methods are still limited by the quality, source, and amount of the utilized reagents. Well-defined non-chemical methods to differentiate stem cells allow stem cell scientists to control stem cell biology by precisely administering the pre-defined parameters, whether they are structural cues, substrate stiffness, or in the form of current flow. We have developed a culture system that allows normal stem cell growth and the option of applying continuous and defined levels of electric current to alter the cell biology of growing cells. This biphasic current stimulator chip employing ITO electrodes generates both positive and negative currents in the same culture chamber without affecting surface chemistry. We found that biphasic electrical currents (BECs) significantly increased the proliferation of fetal neural stem cells (NSCs). Furthermore, BECs also promoted the differentiation of fetal NSCs into neuronal cells, as assessed using immunocytochemistry. Our results clearly show that BECs promote both the proliferation and neuronal differentiation of fetal NSCs. It may apply to the development of strategies that employ NSCs in the treatment of various neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases

Recurrence of sickness absence due to common mental disorders

PURPOSE: Common mental disorders (CMDs) are an important cause of work disability. Although CMDs are known to have high recurrence rates, little is known about the recurrence of sickness absence due to CMDs. This study examines the recurrence risk of sickness absence due to CMDs. METHODS: A cohort of 9,904 employees with a sickness absence due to CMDs, working in the Dutch Post or Telecommunication company, was studied over a 7-year period. Recurrence was defined as the start of at least one new episode of sickness absence with CMDs after complete return to work for at least 28 days. The recurrence density (RD) of sickness absence with CMDs was calculated per 1,000 person-years. RESULTS: Of the 9,904 employees with a first absence due to CMDs 1,925 (19%) had a recurrence, 90% of recurrences occurred within 3 years. The RD of sickness absence due to CMDs was 84.5 employees per 1,000 person-years (95% CI = 80.7-88.3). The RD of sickness absence due to CMDs was similar in women and in men. In men, depressive symptoms were related to higher recurrence of sickness absence due to CMDs than distress symptoms and adjustment disorders. In women, no difference by diagnostic category was found. CONCLUSIONS: Employees with a previous episode of sickness absence with CMDs are at increased risk of recurrent sickness absence with CMDs. Relapse prevention consultations are recommended for a period of 3 years after return to work