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Biomedical subjects

C Heine

Publications and source records attributed to C Heine.

At least 19 recordsLinked to original sources
PubMed2006

P2 receptor-stimulation influences axonal outgrowth in the developing hippocampus in vitro.

Extracellular ATP might act as a trophic factor on growing axons during development of the CNS via P2 receptors. In the present study the postnatal presence of selected P2 receptor subtypes was analyzed and their putative trophic capacity in entorhino-hippocampal slice co-cultures of mouse brain was tested. The effect of the P2 receptor ligands 2-methylthioadenosine-5'-triphosphate (P2X/Y receptor agonist) and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (P2X/Y receptor antagonist) on axonal growth and fiber density of biocytin-labeled hippocampal projections was compared both with untreated cultures and with cultures treated with artificial cerebrospinal fluid. After 10 days in vitro, double immunofluorescence labeling revealed the expression of P2X(1), P2X(2), P2X(4) as well as P2Y(1) and P2Y(2) receptors in the examined regions of entorhinal fiber termination. Further, quantitative analysis of identified biocytin-traced entorhinal fibers showed a significant increase in fiber density in the dentate gyrus after incubation of the slices with the P2 receptor agonist 2-methylthioadenosine-5'-triphosphate. This neurite outgrowth promoting effect was completely abolished by the P2 receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid. Our in vitro data indicate that ATP via its P2X and P2Y receptors can shape hippocampal connectivity during development.

Adenosine Triphosphate↗
PubMed2004

P2Y receptor expression on astrocytes in the nucleus accumbens of rats.

The expression of purinoceptor (P2)Y-subtypes on astrocytes in vivo under physiological conditions and after stab wound injury was investigated. Reverse transcriptase-polymerase chain reaction with specific primers for the receptor-subtypes P2Y1,2,4,6,12 in tissue extracts of the nucleus accumbens of untreated rats revealed the presence of all P2Y receptor mRNAs investigated. Double immunofluorescence visualized with laser scanning microscopy indicated the expression of the P2Y1,4 receptors on glial fibrillary acidic protein (GFAP)-labeled astrocytes under physiological conditions. After stab wound injury the additional expression of the P2Y2 and P2Y6 receptors, and an up-regulation of the P2Y1,4 receptor-labeling on astrocytic cell bodies and/or processes was observed. Astrocytes of cortical, in contrast to accumbal areas exhibited P2Y1,2,4,6 receptor-immunoreactivity (IR) under control conditions, which was up-regulated after stab would injury. Labeling for the P2Y12 receptor was not observed on GFAP-positive cortical and accumbal astrocytes under any of the conditions used. For the first time, the co-localization of different P2 receptor-subtypes (e.g. P2Y1 and P2X3) on the same astrocyte was shown immunocytochemically. The up-regulation of P2Y1 receptor-IR on astrocytes and non-glial cells after mechanical injury could be facilitated by microinfusion of the P2Y1,12,13 receptor agonist adenosine 5'-O-(2-thiodiphosphate) (ADPbetaS). Proliferative changes after ADPbetaS-microinjection were characterized by means of double-staining with antibodies against GFAP and 5-bromo-2'-deoxyuridine. The non-selective P2 receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid, the P2Y1 receptor antagonist N6-methyl-2'-deoxyadenosine 3',5'-bisphosphate and the P2Y1 receptor-antibody itself inhibited the agonist-induced effects. The data indicate the region-specific presence of P2Y receptors on astrocytes in vivo and their up-regulation after injury as well as the co-localization of P2X and P2Y receptor-subtypes on the same astrocyte. The dominant role of P2Y1 receptors in proliferation and the additional stimulation of non-P2Y1 receptors has been demonstrated in vivo suggesting the involvement of this receptor-type in the gliotic response under physiological and pathological conditions.

Adenosine Diphosphate↗
PubMed2002

Communication and psychosocial consequences of sensory loss in older adults: overview and rehabilitation directions.

With increasing longevity among populations, age-related vision and hearing impairments are becoming prevalent conditions in the older adult populations. In combination dual sensory loss occurs. Dual sensory loss is becoming a more common condition seen by clinicians and previous research has shown that 6% of non-institutionalized older adults had a dual sensory impairment, whilst 70% of severely vision-impaired older adults also demonstrated a significant hearing loss. Decreased vision and/or hearing acuity interferes with reception of the spoken message and hence people with sensory loss frequently experience communication breakdown. Many personal, situational and environmental triggers are also responsible for communication breakdown. Limited ability to improve communication performance frequently results in poor psychosocial functioning. Older adults with sensory loss often experience difficulty adjusting to their sensory loss. Depression, anxiety, lethargy and social dissatisfaction are often reported. Sensory loss, decreased communication performance and psychosocial functioning impacts on one's quality of life and feelings of well-being. Rehabilitation services for older adults with age-related sensory loss need to accommodate these difficulties. Improved staff education and rehabilitation programmes providing clients and carers with strategies to overcome communication breakdown is required. A multidisciplinary perspective to the assessment and remediation of older adults is recommended.

Activities of Daily Living↗
PubMed2002

Communication perceptions of older adults with sensory loss and their communication partners: implications for intervention.

INTRODUCTION: Vision and hearing loss are prevalent disorders in older adults although their effects on communication are not well documented. METHOD: The purpose of this study was to investigate the perceptions of older adults with sensory loss and their communication partners with regard to their communication, situational difficulties and conversational needs. RESULTS: Questionnaire results revealed that the sensory loss group experienced a range of functional vision and hearing difficulties. Over two-thirds of subjects reported frequent conversational difficulty, particularly in background noise and group conversations. Most subjects used clarification requests (mainly non-specific clarification and repetition requests) to overcome misunderstandings. By contrast, the communication partners reported few communication difficulties and claimed that they proactively eliminated or controlled environmental, speaker and listener variables to optimize conversation. The most frequently reported strategy was repetition. CONCLUSION: The findings suggest that older adults with sensory loss experience communication disruptions, which in many instances are not resolved. To optimize communication efficacy in this population, a communication training programme for people with sensory loss and their communication partners is highly recommended.

Adaptation, Psychological↗
PubMed2002

NMR velocimetry of falling liquid films.

First results on NMR velocimetry of falling liquid films are presented. A film of average thickness 1 mm and width 40 mm is sustained by a continuous flow of silicon oil over a vertical plate made from PMMA. The spatial distribution of velocities is measured using a double spin--echo imaging pulse sequence supplemented by a bipolar velocity encoding gradient. Spin density and velocity images as well as two-dimensional velocity maps of different situations, i.e., undisturbed and disturbed falling film flow, are discussed. Experimental and theoretical velocity data for undisturbed film flow are compared.

Journal Article↗
PubMed2002

Three-dimensional MR visualization of the intracisternal course of the cranial nerves V-VIII by virtual cisternoscopy.

PURPOSE: A post-processing protocol for 3D visualization of the cranial nerves V-VIII along their intracisternal course is presented. MATERIAL AND METHODS: Six healthy volunteers underwent MR imaging (1.5 T) to obtain high-resolution heavily T2-weighted data sets (3DFT CISS) with isotropic voxels (0.5 mm3). The data sets were post-processed by using volume rendering software in order to visualize the intracisternal courses of the cranial nerves V-VIII as well as their root entry zones. The data acquisition and post-processing protocol was then applied in 14 patients with a suspected neural compression syndrome according to the clinical findings as well as cross-sectional images and evaluated with respect to image quality and diagnostic value by two neuroradiologists, using a five-point scale. RESULTS: Virtual cisternoscopy allowed a comprehensive intracisternal 3D visualization of the affected cranial nerves in 12/14 patients. The mean post-processing time amounted to 13.1/5.6/13.7 min for the cranial nerves V/VI/VII and VIII. The mean score for image quality was 4.2, that for diagnostic value 4.1. 2D and/or 3D reference images were indispensable for appreciating the spatial information provided by virtual cisternoscopy. CONCLUSION: The data acquisition and post-processing protocol presented here allows comprehensive and standardized intracisternal 3D visualization of the cranial nerves V-VIII in a routine setting as a complementary imaging procedure.

Abducens Nerve↗
PubMed2001

Modelled influences of non-exchanging trichomes on leaf boundary layers and gas exchange.

The two main resistances in the exchange of gases between plants and the atmosphere are stomatal and boundary layer resistances. We modeled boundary layer dynamics over glabrous and pubescent leaves (assuming non-exchanging trichomes) with leaf lengths varying from 0.01 to 0.2 m, and windspeeds of 0.1-5.0 m x s(-1). Results from theoretical and semi-empirical formulae were compared. As expected, boundary layer thickness decreased with decreasing leaf length and increasing windspeed. The presence of trichomes increased leaf surface roughness, resulting in lowered Reynolds numbers at which the boundary layer became turbulent. This effect is especially important at low windspeeds and over small leaves, where the Reynolds number over glabrous surfaces would be low. We derived a new simple dimensionless number, the trip factor, to distinguish field conditions that would lead to a turbulent boundary layer based on the influence of trichomes. Because modeled rates of CO2 and H2O(v) exchange over turbulent boundary layers are one or more orders of magnitude faster than over laminar boundary layers, a turbulent boundary layer may lead to increased carbon uptake by plants. The biological trade-off is potentially increased transpirational water loss. However, in understory habitats characterized by low windspeeds, even a few trichomes may increase turbulence in the boundary layer, thus facilitating photosynthetic gas exchange. Preliminary field data show that critical trip factors are exceeded for several plant species, both in understory and open habitats.

Carbon Dioxide↗
PubMed1991

Development of gerontological nursing theory. Applying the man-living-health theory of nursing.

The development of gerontological nursing is an important focus for nursing, given the increasing population of older persons that is requiring nursing care. There are a variety of approaches that have been proposed to provide direction in the development of gerontological nursing theory. The theory of Man-Living-Health was used to describe how gerontological nursing knowledge could be developed through the utilization of a nursing conceptual model that includes a defined practice and research methodology. Continued work in identifying and expanding the theory that underpins gerontological nursing is essential for gerontological nursing practice, research, and education.

Aged↗
PubMed1990

Is gerontological nursing included in baccalaureate nursing programs?

There is a significant effort to include gerontological nursing in baccalaureate nursing programs, but there needs to be continuous evaluation as to the nature and extent of this content. The four stages of the Curriculum Process Model (directive, formative, functional, and evaluative) provide a logical and systematic approach for developing or revising a curriculum. Although the status of gerontological nursing content, faculty preparation, and clinical settings for gerontological experiences have improved, they still do not provide the necessary educational background for students.

Curriculum↗