Caloric Restriction in Older Adults-Differential Effects of Weight Loss and Reduced Weight on Brain Structure and Function

Dietary modifications such as caloric restriction (CR) have been suggested as a means to improve memory and prevent age-related decline. However, it is unclear whether those effects remain stable over time or are related specifically to negative energy balance during the weight loss phase of CR. Using a randomized interventional design, we investigated changes in recognition memory and neural correlates in postmenopausal obese women (n = 19): 1) after intense weight loss in the course of a 12-week low-caloric diet (reduced body weight and negative energy balance) and 2) after having sustained the reduced weight over 4 more weeks (reduced body weight, but energy balance equilibrium). Participants were contrasted to a control group (n = 18) instructed not to change dietary habits. In the CR group, we found improved recognition memory, paralleled by increased gray matter volume in inferior frontal gyrus and hippocampus, and augmented hippocampal resting-state functional connectivity to parietal areas. Moreover, effects were specific for transient negative energy balance and could not be detected after subsequent weight maintenance. Our data demonstrate for the first time in humans that beneficial effects of CR on brain structure and function are due to weight loss rather than an overall reduced weight.

[Quality of universal newborn hearing screening results : Multicenter analysis of data recorded between 2009 and 2012 in four German states]

BACKGROUND

Bearing in mind the impending evaluation of newborn hearing screening in Germany, this study investigated whether multicenter analysis of the screening results from four German states is possible and to what extent the results meet national quality and outcome criteria.

MATERIALS AND METHODS

The screening data from 170 hospitals and a total of 533,150 newborns (21 % of all German newborns) from 2009 to 2012 were evaluated according to definite rules and analyzed in terms of averages, as well as over time.

RESULTS

During the investigated period and averaged over the hospitals, the quality criteria "percentage of screened newborns" (91.4 %) and "percentage requiring further follow-up" (5.0 %), the "day of screening" (day 4), as well as the target parameter "age at diagnosis" (4.8 months) were not met. Steady improvements were observed over time: in the last year of the evaluation, 95.3 % of children were examined; only 4.8 % required follow-up and the age at diagnosis decreased to 4.2 months. On average, 83 % of the babies were screened before day 4. The steady reduction in variance of most of the variables from the participating hospitals indicates continual improvement.

CONCLUSION

A multicenter analysis of screening data is possible and valid in the case of good quality data.

Phorbol ester-induced down modulation of tailless CD4 receptors requires prior binding of gp120 and suggests a role for accessory molecules

The entry of human immunodeficiency virus type 1 into cells proceeds via a fusion mechanism that is initiated by binding of the viral glycoprotein gp120-gp41 to its cellular receptor CD4. Species- and tissue-specific restrictions to viral entry suggested the participation of additional membrane components in the postbinding fusion events. In a previous study (H. Golding, J. Manischewitz, L. Vujcic, R. Blumenthal, and D. Dimitrov, J. Virol. 68:1962-1968, 1994), it was found that phorbol myristate acetate (PMA) inhibits human immunodeficiency virus type 1 envelope-mediated cell fusion by inducing down modulation of an accessory component(s) in the CD4-expressing cells. The fusion inhibition was seen in a variety of cells, including T-cell transfectants expressing engineered CD4 receptors (CD4.401 and CD4.CD8) which are not susceptible to down modulation by PMA treatment. In the current study, it was found that preincubation of A2.01.CD4.401 cells with soluble monomeric gp120 for 1 h at 37 degrees C primed them for PMA-induced down modulation (up to 70%) of the tailless CD4 receptors. The gp120-priming effect was temperature dependent, and the down modulation may have occurred via clathrin-coated pits. Importantly, nonhuman cell lines expressing tailless CD4 molecules did not down modulate their CD4 receptors under the same conditions. The gp120-dependent PMA-induced down modulation of tailless CD4 receptors could be efficiently blocked by the human monoclonal antibodies 48D and 17B, which bind with increased avidity to gp120 that was previously bound to CD4 (M. Thali, J. P. Moore, C. Furman, M. Charles, D. D. Ho, J. Robinson, and J. Sodroski, J. Virol. 67:3978-3988, 1993). These findings suggest that gp120 binding to cellular CD4 receptors induces conformational changes leading to association of the gp120-CD4 complexes with accessory transmembrane molecules that are susceptible to PMA-induced down modulation and can target the virions to clathrin-coated pits.

[Postoperative warming therapy in the recovery room. A comparison of radiative and convective warmers]

Hypothermia (Tcore < 36 degrees C) can be observed in 60%-80% of all admissions to the post-anaesthetic recovery unit. Effective warming devices may accelerate rewarming, improve patient comfort, and suppress shivering thermogenesis. This study was designed to compare the efficiency of warming devices in extubated postoperative patients and their effect on postoperative oxygen uptake (VO2). METHODS. Thirty-five ASA I and II patients after laparoscopic hernioplastic repair with core temperatures < 36 degrees C were randomly assigned to either postoperative nursing under a radiant heater (group R, n = 11, Aragona Thermal Ceilings CTC X, Aragona Medical AB, Täby, Sweden), a forced air system (group L, n = 12, Bair Hugger, Augustine Medical Inc., Eden Prairie, Minnesota, USA), or a normal cotton hospital blanket (group K, n = 12). Anaesthesia was conducted totally intravenously with propofol, alfentanil, and vecuronium. Mean body temperature and total body heat were calculated from urinary bladder temperature and four subcutaneous temperature measurements. The rate of thermogenesis was calculated from continuous measurement of VO2 (Datex Deltatrac Metabolic Monitor, Datex Instrumentarium Corp., Helsinki, Finland). Heat balance was derived from the increase in total body heat minus body heat production. Heart rate and noninvasive blood pressure were measured by the Cardiocap (Datex Instrumentarium Corp., Helsinki, Finland). All data were transferred to an IBM-compatible computer at 60-s intervals. Measurements were stopped when core temperature reached 37 degrees C. The rate of change was calculated for each variable for the period 15 min after the beginning of rewarming to attainment of 37 degrees C. Data are presented as median, minima, and maxima (min<==>max); the Mann-Whitney U test was used to test for significance of group differences. RESULTS. All groups were comparable for body weight, height, age, and amount of postoperative infusions. Temperatures at admission were 35.2 (33.4<==>35.9), 34.7 (34.3<==>35.8), and 35.4 (34.3<==>35.9) degrees C for groups R, B, and K, respectively. No significant differences in the rate of central rewarming could be found for these groups with 0.81 (0.41<==>1.32), 0.76 (0.40<==>1.07), and 0.70 (0.37<==>1.13) degrees C/h (Fig. 1). The mean VO2 of 3.41 (3.07<==>3.73), 3.55 (2.78<==>4.06), and 3.79 (2.51<==>7.00) ml/kg/min also did not differ significantly (Fig. 3). Significant differences between groups R and B [4.39 (3.74<==>6.19) and 4.30 (3.46<==>6.67) ml/kg/min] and K [5.92 (3.79<==>10.64) ml/kg/min] were found for VO2 maxima during the course of investigation (Fig. 4). The heat balance revealed significant differences among treatment and control groups with -88 (-226<==>+30), -41 (-212<==>+12), and -191 (-265<==>-86) kJ/h for groups R, B, and K. We additionally calculated the heat balance as a quotient, which showed 0.70 (0.22<==>1.07), 0.86 (0.44<==>1.04), and 0.49 (0.31<==>0.79) for groups R, B, and K (Fig. 4). The mean rate-pressure product of all groups did not differ significantly during the period of investigation. CONCLUSIONS. Neither external heat supply by radiant heat nor by a forced warm air system significantly reduced rewarming time in extubated, awake patients. As measured by heat balance, both active treatments saved about 20% more body heat production than in the control group. Continuing peripheral vasoconstriction may be the reason for the low efficiency of heat transfer. Thermal treatment did reduce the peak load (max. VO2) on the oxygen transport systems, though shivering was treated by pethidine if it occurred. External rewarming did not reduce the average load (mean VO2). Thus, concerning the goal of accelerating rewarming, it appears more rational to prevent intraoperative heat loss. For a comparison of efficiency of different warming devices, postoperative extubated patients do not appear to be an ideal model for study.