Structural architecture supports functional organization in the human aging brain at a regionwise and network level

Functional interactions in the brain are constrained by the underlying anatomical architecture, and structural and functional networks share network features such as modularity. Accordingly, age‐related changes of structural connectivity (SC) may be paralleled by changes in functional connectivity (FC). We provide a detailed qualitative and quantitative characterization of the SC–FC coupling in human aging as inferred from resting‐state blood oxygen‐level dependent functional magnetic resonance imaging and diffusion‐weighted imaging in a sample of 47 adults with an age range of 18–82. We revealed that SC and FC decrease with age across most parts of the brain and there is a distinct age‐dependency of regionwise SC–FC coupling and network‐level SC–FC relations. A specific pattern of SC–FC coupling predicts age more reliably than does regionwise SC or FC alone (r = 0.73, 95% CI = [0.7093, 0.8522]). Hence, our data propose that regionwise SC–FC coupling can be used to characterize brain changes in aging. Hum Brain Mapp 37:2645–2661, 2016. © 2016 Wiley Periodicals, Inc.     

Short Bouts of Intensive Exercise During the Workday Have a Positive Effect on Neuro‐cognitive Performance

Beside its positive impact on physical health, exercise is indicated to positively affect cognitive performance based on a relocation of cortical activity. This study examined the influence of different types of breaks on cognitive performance and related cortical activity in office‐based employees. Breaks were filled with exercise, resting or a usual break and a control condition where employees continued working without any break. Cognitive performance was assessed using the d2‐R test and two commercially available cognitive tasks. Brain cortical activity was recorded using electroencephalography before and after breaks. Individual's mood was analysed using a profile of mood state. Results indicate a positive effect of a 3‐min boxing intervention on cognitive performance, mirrored by a decrease in prefrontal cortex activity. Although perceived psychological state was increased after the usual break, this is reflected in neither cortical activity nor cognitive performance. With respect to the fact that also bike activity resulted an increase in prefrontal alpha‐2 activity, a positive effect of exercise on neuro‐cognitive performance can be stated. Health and economic benefits may result from brief physical activity breaks and help to maintain workplace performance and job satisfaction. Copyright © 2015 John Wiley & Sons, Ltd.     

Dynamic changes of B‐cell compartments in kidney transplantation: lack of transitional B cells is associated with allograft rejection

B cells play an important role in the immune responses which affect the outcomes of kidney allografts. Dynamic changes of B‐cell compartments in clinical kidney transplantation are still poorly understood. B‐cell subsets were prospectively monitored using flow cytometry for 1 year in 98 kidney transplant recipients. Data were correlated with immunosuppression and clinical outcomes. An increase in the total population of B lymphocytes was observed during the first week after transplantation. The level of IgM^highCD38^highCD24^high transitional B cells reduced significantly up until the third month, with partial repopulation in the first year. Lower numbers of transitional B cells in the third month were associated with higher risk of graft rejection. IgM⁺IgD⁺CD27^? naive B cells did not change within follow‐up. IgM⁺CD27⁺ nonswitched memory B cells and IgM^?CD27⁺ switched memory B cells increased on post‐operative day 7. IgM^?CD38^highCD27^high plasmablasts showed similar kinetics during the first post‐transplant year, similar to transitional B cells. In conclusion, sensitized kidney transplant recipients as well as those with either acute or chronic rejection within the first post‐transplant year exhibited lower levels of transitional B cells. Therefore, these data further support the hypothesis that transitional B cells have a protective role in kidney transplantation.     

Retrieval of a Greenfield IVC Filter Displaced to the Right Brachiocephalic Vein

During insertion of a central venous sheath an inferior vena cava stainless steel Greenfield filter was dislodged to the right brachiocephalic vein without a free end. Successful retrieval was achieved by using a combination of a guidewire and a snare. Percutaneous retrieval of this vena cava filter is feasible with minimal risk using this method.     

Lipid Levels: A Link Between Cardiovascular Disease and Osteoporosis?

Epidemiological observations support a positive relationship between cardiovascular diseases (CVD) and osteoporosis, where cholesterol has been indicated to be a possible link. Only a few studies have investigated the relation between lipids and BMD, but the association remains unclear. We studied the relationship between serum lipids and BMD of the calcaneus. A cross‐sectional population‐based study was performed, based on data from the Longitudinal Aging Study Amsterdam, including 620 men and 635 women, 65–88 yr of age. BMD was measured by quantitative ultrasound (QUS), velocity of sound (VOS; m/s), and broadband ultrasound attenuation (BUA; dB/MHz). Models were adjusted for age, body mass index, physical activity, smoking, alcohol, diabetes mellitus, hypertension, testosterone, and 25‐hydroxyvitamin D. No association was found between total cholesterol (TC) and QUS. Men and women in the highest quartile of high‐density lipoprotein cholesterol (HDL‐c) had a significantly lower QUS (men—VOS: β = ?20.8, p = 0.00; BUA: β = ?5.2, p = 0.02; women—VOS: β = ?18.6, p = 0.00) compared with men and women in the lowest quartile. An even stronger positive association was seen between TC/HDL‐c ratio and QUS (men—VOS: β = 21.8, p = 0.00; BUA: β = 5.5, p = 0.01; women—VOS: β = 19.2, p = 0.00; BUA: β = 3.6, p = 0.05). Our analysis shows that the lipid profile that is favorable in the prevention of CVD (i.e., high levels of HDL‐c and low TC/HDL‐c ratio) is unfavorable for QUS. These results indicate that HDL‐c levels do not explain the association between osteoporosis and CVD.     

Heme oxygenase-1 attenuates ischemia/reperfusion-induced apoptosis and improves survival in rat renal allografts

BACKGROUND: Kidneys can be preserved only for a limited time without jeopardizing graft function and survival. Induction of heat shock proteins (HSPs) can protect against ischemia/reperfusion (I/R) injury. Therefore, we investigated whether the induction of the HSP, heme oxygenase-1 (HO-1), improves outcome following isotransplantation after an extended period of cold storage. METHODS: Rats were subjected to heat preconditioning (HP; 42 degrees C for 20 minutes). Kidneys harvested after 24 hours, were preserved in cold University of Wisconsin (UW) solution at 4 degrees C for 45 hours and transplanted into bilateral nephrectomized rats. Cobalt protoporphyrin (CoPP) was administered in another group of animals in order to induce HO-1 pharmacologically, while other groups of animals received the HO-1 inhibitor, tin protophorphyrine (SnPP), following HP or CoPP. RESULTS: Cold ischemia caused a complete attenuation of graft function within 3 days following transplantation and subsequent death of all animals, whereas HP protected graft function and five of nine rats survived for 3 weeks. HP inhibited the induction of osteopontin and induced the expression of HO-1, HSP 70 and 90, and the antiapoptotic factor Bcl-XL. Grafts exposed to HP were protected against structural I/R injuries as revealed by histologic assessment using a semiquantitative score. Furthermore, induction of apoptosis was attenuated and activation of caspase-3 was inhibited. Comparable results were observed after administration of CoPP, whereas SnPP inhibited the effects of HP and CoPP. CONCLUSION: HP or administration of CoPP induced both HO-1, preserved kidney graft function, and prevented postreperfusion apoptosis after cold preservation.