Establishing neuronal identity in vertebrate neurogenic placodes

The trigeminal and epibranchial placodes of vertebrate embryos form different types of sensory neurons. The trigeminal placodes form cutaneous sensory neurons that innervate the face and jaws, while the epibranchial placodes (geniculate, petrosal and nodose) form visceral sensory neurons that innervate taste buds and visceral organs. In the chick embryo, the ophthalmic trigeminal (opV) placode expresses the paired homeodomain transcription factor Pax3 from very early stages, while the epibranchial placodes express Pax2. Here, we show that Pax3 expression in explanted opV placode ectoderm correlates at the single cell level with neuronal specification and with commitment to an opV fate. When opV (trigeminal) ectoderm is grafted in place of the nodose (epibranchial) placode, Pax3-expressing cells form Pax3-positive neurons on the same schedule as in the opV placode. In contrast, Pax3-negative cells in the grafted ectoderm are induced to express the epibranchial placode marker Pax2 and form neurons in the nodose ganglion that express the epibranchial neuron marker Phox2a on the same schedule as host nodose neurons. They also project neurites along central and peripheral nodose neurite pathways and survive until well after the main period of cell death in the nodose ganglion. The older the opV ectoderm is at the time of grafting, the more Pax3-positive cells it contains and the more committed it is to an opV fate. Our results suggest that, within the neurogenic placodes, there does not appear to be a two-step induction of 'generic' neurons followed by specification of the neuron to a particular fate. Instead, there seems to be a one-step induction in which neuronal subtype identity is coupled to neuronal differentiation

The effect of prior upper body exercise on subsequent wingate performance

It has been reported previously that the upper body musculature is continually active during high intensity cycle ergometry. The aim of this study was to examine the effects of prior upper body exercise on subsequent Wingate (WAnT) performance. Eleven recreationally active males (20.8 ± 2.2 yrs; 77.7 ± 12.0 kg;  1.79 ± 0.04 m) completed two trials in a randomised order. In one trial participants completed 2 × 30 s WAnT tests (WAnT1 and WAnT2) with a 6 min recovery period; in the other trial, this protocol was preceded with 4 sets of biceps curls to induce localised arm fatigue. Prior upper body exercise was found to have a statistically significant detrimental effect on peak power output (PPO) during WAnT1 (P < 0.05) but no effect was observed for mean power output (MPO) (P > 0.05). Handgrip (HG) strength was also found to be significantly lower following the upper body exercise. These results demonstrate that the upper body  is meaningfully involved in the generation of leg power during intense cycling

Competence, specification and induction of Pax-3 in the trigeminal placode

Placodes are discrete regions of thickened ectoderm that contribute extensively to the peripheral nervous system in the vertebrate head. The paired-domain transcription factor Pax-3 is an early molecular marker for the avian ophthalmic trigeminal (opV) placode, which forms sensory neurons in the ophthalmic lobe of the trigeminal ganglion. Here, we use collagen gel cultures and heterotopic quail-chick grafts to examine the competence, specification and induction of Pax-3 in the opV placode. At the 3-somite stage, the whole head ectoderm rostral to the first somite is competent to express Pax-3 when grafted to the opV placode region, though competence is rapidly lost thereafter in otic-level ectoderm. Pax-3 specification in presumptive opV placode ectoderm occurs by the 8-somite stage, concomitant with robust Pax-3 expression. From the 8-somite stage onwards, significant numbers of cells are committed to express Pax-3. The entire length of the neural tube has the ability to induce Pax-3 expression in competent head ectoderm and the inductive interaction is direct. We propose a detailed model for Pax-3 induction in the opV placode

Early- and late-migrating cranial neural crest cell populations have equivalent developmental potential in vivo

We present the first in vivo study of the long-term fate and potential of early-migrating and late-migrating mesencephalic neural crest cell populations, by performing isochronic and heterochronic quail-to-chick grafts. Both early- and late-migrating populations form melanocytes, neurons, glia, cartilage and bone in isochronic, isotopic chimeras, showing that neither population is lineage-restricted. The early-migrating population distributes both dorsally and ventrally during normal development, while the late-migrating population is confined dorsally and forms much less cartilage and bone. When the late-migrating population is substituted heterochronically for the early-migrating population, it contributes extensively to ventral derivatives such as jaw cartilage and bone. Conversely, when the early-migrating population is substituted heterochronically for the late-migrating population, it no longer contributes to the jaw skeleton and only forms dorsal derivatives. When the late-migrating population is grafted into a late-stage host whose neural crest had previously been ablated, it migrates ventrally into the jaws. Thus, the dorsal fate restriction of the late-migrating mesencephalic neural crest cell population in normal development is due to the presence of earlier-migrating neural crest cells, rather than to any change in the environment or to any intrinsic difference in migratory ability or potential between early- and late-migrating cell populations. These results highlight the plasticity of the neural crest and show that its fate is determined primarily by the environment

The experiences of professional nurses in providing compassionate patient care in a private hospital in Gauteng, South Africa : a qualitative narrative analysis

Compassionate care is a crucial component of patient care in nursing practice in the broad context of holistic care. However, it is seemingly difficult for nurses to identify what exactly comprises compassionate care and how to provide it to patients. The purpose of the study was to explore the experiences of professional nurses on how they provide compassionate patient care. A qualitative descriptive study design based on narrative analysis was used. Thirteen professional nurses (PNs) from a private hospital were purposefully recruited to participate. Data was collected using written stories and professional lifelines. Data was analysed using thematic and narrative analysis. The following themes were identified such as treating the patient as a whole, inadequate knowledge and skills, and barriers to providing compassionate care. Future research using quantitative approach and large samples was recommended.Health StudiesM.A. (Health Studies

A Pilot Study: Understanding Health Literacy and Linguistic Factors Related to African Immigrants Engagement in Primary Health Care in Massachusetts

Culture impacts how individuals understand, communicate, and respond to health information. Immigrants to the U.S. come from diverse cultural groups and have varying understandings of health care and the U.S. health care system. The primary aim of this study is to explore cultural interpretations and beliefs of select health concepts and to assess the health literacy of African immigrants in Massachusetts. We are a partnership between UMass Graduate School of Nursing, Africans for Improved Access program at the Multicultural AIDS Coalition and Clark University. Using a CBPR approach has been valuable in the design of the study and in our ability to access and engage African immigrants. We are recruiting 100 African immigrants during cultural events, targeted outreach and gatherings in religious communities to complete a Freelist exercise, 2 health literacy assessment tools, and a general health survey. Results of the Freelist exercise will inform development of an interview guide that will be used with 3 Focus Groups of African immigrants to help us understand the cultural interpretation of frequently used health related words and phrases. We are assessing the feasibility and acceptability of 2 health literacy instruments to determine the appropriateness of using these assessments with an immigrant population. The association of health literacy to accessing primary care will be examined. The focus group and general health survey data will help us gain a better understanding of the primary care health experiences of African immigrants and potential factors that facilitate or hinder their engagement in primary health care