Joseph F. Lucke

Relation of education to brain size in normal aging: implications for the reserve hypothesis.

Objective: To examine the relations between education and age-related changes in brain structure in a nonclinical sample of elderly adults. Background: Education may protect against cognitive decline in late life—an observation that has led to the “reserve” hypothesis of brain aging. Little is known, however, about the effect of education on age-related changes in brain structure. Methods: Quantitative MRI of the brain was performed in 320 elderly volunteers (age range, 66 to 90 years) living independently in the community (Mini-Mental State Examination scores ≥ 24), all of whom were participants in the Cardiovascular Health Study. Blinded measurements of global and regional brain size were made from T1-weighted axial images using computer-assisted edge detection and trace methodology. High measurement reliabilities were obtained. Results: Regression analyses (adjusting for the effects of intracranial size, sex, age, age-by-sex interactions, and potential confounders) revealed significant main effects of education on peripheral (sulcal) CSF volume—a marker of cortical atrophy. Each year of education was associated with an increase in peripheral CSF volume of 1.77 mL (p < 0.03). As reported previously, main effects of age (but not education) were observed for all of the remaining brain regions examined, including cerebral hemisphere volume, frontal region area, temporoparietal region area, parieto-occipital region area, lateral (Sylvian) fissure volume, lateral ventricular volume, and third ventricle volume. Conclusions: The authors’ findings demonstrate a relation between education and age-related cortical atrophy in a nonclinical sample of elderly persons, and are consistent with the reserve hypothesis as well as with a small number of brain imaging studies in patients with dementia. The neurobiological basis and functional correlates of this education effect require additional investigation.

Altered fecal microflora and increased fecal calprotectin in infants with colic.

OBJECTIVE We explored whether gut inflammation, colonic fermentation, and/or an altered colonic flora could provide a pathophysiological mechanism for colic. STUDY DESIGN The study population consisted of 36 term infants ranging in age from 14 to 81 days. We measured fecal calprotectin (a marker of neutrophil infiltration) by ELISA; stool microorganisms by denaturing gradient gel electrophoresis, cloning, and sequencing; and breath hydrogen levels using gas chromatography. RESULTS During 24 hours, infants with colic (n = 19) cried and fussed for a mean of 314 +/- 36 (SEM) minutes, compared with control infants (n = 17, 103 +/- 17 minutes). Fecal calprotectin levels were 2-fold higher in infants with colic than in control infants (413 +/- 71 vs 197 +/- 46 microg/g, P = .042). Stools of infants with colic had fewer identifiable bands on denaturing gradient gel electrophoresis. Klebsiella species were detected in more colic patients than in control patients (8 vs 1, P = .02), whereas Enterobacter/Pantoea species were detected only in the control patients. These differences could not be attributed to differences in formula versus breast milk feeding, consumption of elemental formula, or exposure to antibiotics. CONCLUSIONS Infants with colic, a condition previously believed to be nonorganic in nature, have evidence of intestinal neutrophilic infiltration and a less diverse fecal microflora.

Salivary cortisol reflects serum cortisol: analysis of circadian profiles

Background: Technical hurdles limit the characterization of key hormonal rhythms. Frequent sampling increases detection of changes in magnitude or circadian and ultradian patterns, but limits feasibility for clinical or research settings. These caveats are particularly pertinent for cortisol, a hormone that displays a prominent circadian rhythm and whose magnitude is tightly regulated in the absence of biobehavioural challenge. Ideally, one would like to obtain samples non-invasively from a matrix of interest at frequent intervals. While many investigations have reported a high correlation between serum and salivary cortisol assays, the degree to which salivary cortisol reflects the circadian patterns of circulating cortisol concentrations has not been established across a 24 h period. Methods: We obtained hourly serum and salivary samples over a 24 h period in nine adults in an inpatient setting. The circadian patterns for serum and salivary cortisol were analysed by harmonic regression. Results: For all but two subjects (both on oral contraceptives), the salivary cortisol concentration was synchronous with the serum concentration, indicating that the salivary assay could be substituted for the serum assay to assess circulating rhythmicity across the 24 h time frame. Conclusions: This statistical model has distinct improvement over the correlational approach of examining serum and saliva cortisol relationships. Saliva cortisol appears to represent serum cortisol across the 24 h period, except for those on oral contraceptives.

Quality of life in spinal cord injured individuals and their caregivers during the initial 6 months following rehabilitation.

Addressing quality of life (QOL) issues in the spinal cord injured (SCI) population is imperative as the majority survive their initial injury and longevity now approaches that of the general population. The purpose of this mixed method, descriptive, longitudinal feasibility study was to describe and compare QOL in 10 adult SCI individuals and their family caregivers (FCs) during the initial 6 months following rehabilitation. Instruments used were the SF-36 and two horizontal visual analog scales, one for pain and one for QOL. Participants completed the instruments and a face-to-face in-depth interview at 1-, 3-, and 6-months following inpatient rehabilitation. SCI individuals reported low physical function, role physical (RP), and role emotional (RE) scores on the SF-36, while reporting high general health (GH), mental health and social functioning on the SF-36. FCs reported lower RP, GH and vitality scores, while reporting higher physical functioning and RE scores. On the visual analog scales, persons with SCI reported lower QOL while FCs reported more pain at 3 and 6 months. This study suggests that more work is needed to identify interventions which could enhance QOL during the transition from rehabilitation to home for SCI individuals and their FCs.

Effects of support on the initiation and duration of breastfeeding

Researchers attempted to increase the initiation of breastfeeding and its duration to 6 months among a group of low-income, Hispanic women through an intervention program which included prenatal education and home based postpartum support. All participants were telephoned after delivery to determine infant feeding method. Duration of breastfeeding was determined by counting the number of days from initiation to the last day the baby was put to the breast. The Bayesian approach was used for the statistical analyses. In the intervention group, the propensity to initiate breastfeeding exceeded that of the control group. Results indicate the intervention group had twice (2.31) the odds of starting breastfeeding, twice (1.84-3.15) the odds of continuing to breastfeed for 6 months, and only half (.50-.54) the tendency to quit at any one time than did the control group.

The impact of a tele-ICU on provider attitudes about teamwork and safety climate

Objective To measure teamwork and safety climate in three intensive care units (ICUs) before and after remote monitoring by intensivists using telemedicine technology (tele-ICU). Design Controlled pre tele-ICU and post tele-ICU cross-sectional survey. Setting ICUs in two non-teaching community hospitals and one tertiary care teaching hospital. Subjects ICU physicians and nurses. Interventions Remote monitoring of ICU patients by intensivists. Outcome measurements Teamwork Climate Scale (TWS), a Safety Climate Score (SCS) and survey items related to tele-ICU. Main results The mean (SD) teamwork climate score was 69.7 (25.3) and 78.8 (17.2), pre and post tele-ICU (p=0.009). The mean SCS score was 66.4 (24.6) and 73.4 (18.5), pre and post tele-ICU (p=0.045). While SCS scores within the ICUs improved, the overall SCS scores for these hospitals decreased from 69.0 to 65.4. Three of the non-scaled items were significantly different pre and post tele-ICU at p<0.001. The item means (SD) pre and post tele-ICU were: “others interrupt my work to tell me something about my patient that I already know” 2.5 (1.2) and 1.6 (1.3); “I am confident that my patients are adequately covered when I am off the unit” 3.2 (1.3) and 4.2 (1.1); and “I can reach a physician in an urgent situation in a timely manner” 3.8 (1.2) and 4.6 (0.6). Conclusions Implementation of a tele-ICU was associated with improved teamwork climate and safety climate in some ICUs, especially among nurses. Providers were also more confident about patient coverage and physician accessibility, and did not report unnecessary interruptions.

A Critique of the False-Positive Report Probability

The false positive report probability (FPRP) was proposed as a Bayesian prophylactic against false reports of significant associations. Unfortunately, the derivation of the FPRP is unsound. A heuristic derivation fails to make its point, and a formal derivation reveals a probabilistic misrepresentation of an observation. As a result, the FPRP can yield serious inferential errors. In particular, the FPRP can use an observation that is many times more likely under the null hypothesis than under the alternative to infer that the null hypothesis is far less probable than the alternative. Contrary to its intended purpose, the FPRP can promote false positive results. It should not be used. A modified FPRP is derived, but it appears to have limited application and does not address the problem of false reports of significant associations. The conditional error probability is a possible replacement for the FPRP. Genet. Epidemiol. 2008.

The effects of core and peripheral warming methods on temperature and physiologic variables in injured children

Introduction Injured children are at risk for thermoregulatory compromise, where temperature maintenance mechanisms are overwhelmed by severe injury, environmental exposure, and resuscitation measures. Adequate thermoregulation can be maintained, and heat loss can be prevented, by core (administration of warmed intravenous fluid) and peripheral (application of convective air warming) methods. It is not known which warming method is better to maintain thermoregulation and prevent heat loss in injured children during their trauma resuscitations. The purpose of this feasibility study was to compare the effects of core and peripheral warming measures on body temperature and physiologic changes in a small sample of injured children during their initial emergency department (ED) treatment. Methods A prospective, randomized experimental design was used. Eight injured children aged 3 to 14 years (mean = 6.87, SD = 3.44 ) treated in the ED of Children’s Hospital of Pittsburgh were enrolled. Physiologic responses (eg, heart rate, blood pressure, respiratory rate, arterial oxygen saturation, core, peripheral temperatures) and level of consciousness were continuously measured and recorded every 5 minutes to detect early thermoregulatory compromise and to determine the child’s response to warming. Data were collected throughout the resuscitation period, including transport to CT scan, the inpatient nursing unit, intensive care unit, operating room or discharge to home. Core warming was accomplished with the Hotline Fluid Warmer (Sims Level 1, Inc., Rockland, MA), and peripheral warming was accomplished with the Snuggle Warm Convective Warming System (Sims Level 1, Inc., Rockland, MA). Data were analyzed using descriptive and inferential statistics. Results There were no statistically significant differences between the two groups on age (t = −0.485,P= 0.645); weight (t = −0.005,P= 0.996); amount of prehospital intravenous (IV) fluid (t = 0.314,P= 0.766); temperature on ED arrival (t = 0.287,P= 0.784); total amount of infused IV fluid (t = −0.21,P= 0.8); and length of time from ED admission to hospital admission (t = −0.613,P= 0.56). There were no statistically significant differences between the two groups on RTS (t = −0.516,P= 0.633). When comparing the mean differences in temperature upon hospital admission, no statistically significant differences were found (t = −1.572,P= 0.167). There were no statistically significant differences between the two groups in tympanic [F(15) = 0.71,P= 0.44] and skin [F(15) = 0.06,P= 0.81] temperature measurements over time. Conclusion Core and peripheral warming methods appeared to be effective in preventing heat loss in this stable patient population. A reasonable next step would be to continue this trial in a larger sample of patients who are at greater risk for heat loss and subsequent hypothermia and to use a control group.