Restoration of cardiac progenitor cells after myocardial infarction by self-proliferation and selective homing of bone marrow-derived stem cells

Tissue-specific progenitor cells contribute to local cellular regeneration and maintain organ function. Recently, we have determined that cardiac side-population (CSP) cells represent a distinct cardiac progenitor cell population, capable of in vitro differentiation into functional cardiomyocytes. The response of endogenous CSP to myocardial injury, however, and the cellular mechanisms that maintain this cardiac progenitor cell pool in vivo remain unknown. In this report we demonstrate that local progenitor cell proliferation maintains CSP under physiologic conditions, with little contribution from extracardiac stem cell sources. Following myocardial infarction in adult mice, however, CSP cells are acutely depleted, both within the infarct and noninfarct areas. CSP pools are subsequently reconstituted to baseline levels within 7 days after myocardial infarction, through both proliferation of resident CSP cells, as well as through homing of bone marrow-derived stem cells (BMC) to specific areas of myocardial injury and immunophenotypic conversion of BMC to adopt a CSP phenotype. We, therefore, conclude that following myocardial injury, cardiac progenitor cell populations are acutely depleted and are reconstituted to normal levels by both self-proliferation and selective homing of BMC. Understanding and enhancing such processes hold enormous potential for therapeutic myocardial regeneration.     

Assessment of Unconscious Decision Aids Applied to Complex Patient-Centered Medical Decisions

Background

To improve patient health, recent research urges for medical decision aids that are designed to enhance the effectiveness of specific medically related decisions. Many such decisions involve complex information, and decision aids that independently use deliberative (analytical and slower) or intuitive (more affective and automatic) cognitive processes for such decisions result in suboptimal decisions. Unconscious thought can arguably use both intuitive and deliberative (slow and analytic) processes, and this combination may further benefit complex patient (or practitioner) decisions as medical decision aids. Indeed, mounting research demonstrates that individuals render better decisions generally if they are distracted from thinking consciously about complex information after it is presented (but can think unconsciously), relative to thinking about that information consciously or not at all.

Objective

The current research tested whether the benefits of unconscious thought processes can be replicated using an Internet platform for a patient medical decision involving complex information. This research also explored the possibility that judgments reported after a period of unconscious thought are actually the result of a short period of conscious deliberation occurring during the decision report phase.

Methods

A total of 173 participants in a Web-based experiment received information about four medical treatments, the best (worst) associated with mostly positive (negative) side-effects/attributes and the others with equal positive-negative ratios. Next, participants were either distracted for 3 minutes (unconscious thought), instructed to think about the information for 3 minutes (conscious thought), or moved directly to the decision task (immediate decision). Finally, participants reported their choice of, and attitudes toward, the treatments while experiencing high, low, or no cognitive load, which varied their ability to think consciously while reporting judgments. Cognitive load was manipulated by having participants memorize semi-random (high), line structured (low), or no dot patterns and recall these intermittently with their decision reports. Overall then, participants were randomly assigned to the conditions of a 3 (thought condition) by 3 (cognitive-load level) between-subjects design.

Results

A logistic regression analysis indicated that the odds of participants choosing the best treatment were 2.25 times higher in the unconscious-thought condition compared to the immediate-decision condition (b=.81, Wald=4.32, P=.04, 95% CI 1.048-4.836), and 2.39 times greater compared to the conscious-thought condition (b=.87, Wald=4.87, P=.027, 95% CI 1.103-5.186). No difference was observed between the conscious-thought condition compared to the immediate-decision condition, and cognitive load manipulations did not affect choices or alter the above finding.

Conclusions

This research demonstrates a plausible benefit of unconscious thinking as a decision aid for complex medical decisions, and represents the first use of unconscious thought processes as a patient-centered medical decision aid. Further, the quality of decisions reached unconsciously does not appear to be affected by the amount of cognitive load participants experienced.     

Sensory Hairs in the Bowhead Whale,Balaena mysticetus (Cetacea,Mammalia)

We studied the histology and morphometrics of the hairs of bowhead whales (Balaena mysticetus). These whales are hairless except for two patches of more than 300 hairs on the rostral tip of the lower lip and chin, the rostral tip of the upper lip, and a bilateral row of approximately ten hairs caudal to the blowhole. Histological data indicate that hairs in all three of these areas are vibrissae: they show an outermost connective tissue capsule, a circumferential blood sinus system surrounding the hair shaft, and dense innervation to the follicle. Morphometric data were collected on hair diameters, epidermal recess diameters, hair follicle length, and external hair lengths. The main difference between the hairs in the different regions is that blowhole hairs have larger diameters than the hairs in the chin and rostrum regions. We speculate that the hair shaft thickness patterns in bowheads reflect functional specializations. Anat Rec, 298:1327–1335, 2015. © 2015 Wiley Periodicals, Inc.     

"It's like losing a part of my family": transition expectations of adolescents living with perinatally acquired HIV and their guardians

The increased life expectancy of perinatally HIV-infected adolescents necessitates the transition from pediatric to adult infectious disease care. Significant differences exist between pediatric and adult HIV clinic models, and adequate preparation is critical for successful transition. The expectations of youth on the cusp of this transition and their guardians have not previously been explored. Semistructured interviews were conducted with 40 perinatally infected adolescents (mean age, 17.3 years; 90% African American; 57.5% female; 57.5% in high school) currently receiving care in a pediatric infectious disease clinic in the southeast United States and 17 guardians about their expectations related to the pending transition to adult care. Interviews were transcribed and coded for emergent themes. Many adolescents had difficulty articulating expectations of their transition to an adult clinic, reporting they did not know what to expect. Others looked forward to increased responsibility and control, while some expressed concerns over leaving their current providers and having to establish new relationships. Most guardians viewed the transition to adult care as a tool to facilitate maturity. Several indicated they had not discussed transition with their child and were waiting for their child to initiate a conversation about it. Given the importance providers place on preparing youth for transition, it is surprising that many adolescents had no expectations about this impending change. This indicates a need for improved communication between providers and adolescents to enhance preparation and ultimately transition success. Additionally, guardians play an important role in the transition process and may need support to discuss this process with their child.     

A randomized controlled trial of a parent-centered intervention in preventing substance use and HIV risk behaviors in Hispanic adolescents

The present study evaluated the efficacy of Familias Unidas + Parent-Preadolescent Training for HIV Prevention (PATH), a Hispanic-specific, parent-centered intervention, in preventing adolescent substance use and unsafe sexual behavior. Two hundred sixty-six 8th-grade Hispanic adolescents and their primary caregivers were randomly assigned to 1 of 3 conditions: Familias Unidas + PATH, English for Speakers of Other Languages (ESOL) + PATH, and ESOL + HeartPower! for Hispanics (HEART). Participants were assessed at baseline and at 6, 12, 24, and 36 months postbaseline. Results showed that (a) Familias Unidas + PATH was efficacious in preventing and reducing cigarette use relative to both control conditions; (b) Familias Unidas + PATH was efficacious, relative to ESOL + HEART, in reducing illicit drug use; and (c) Familias Unidas + PATH was efficacious, relative to ESOL + PATH, in reducing unsafe sexual behavior. The effects of Familias Unidas + PATH on these distal outcomes were partially mediated by improvements in family functioning. These findings suggest that strengthening the family system, rather than targeting specific health behaviors, may be most efficacious in preventing and/or reducing cigarette smoking, illicit drug use, and unsafe sex in Hispanic adolescents.