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PubMed2001

Use of hair pores to determine the orientation of collagen fibers in skin.

Most people are interested in recovery of skin defects caused by burn, scald or trauma from the aesthetic and functional point of view. It will occupy an important role for successful skin graft for patients with such skin defects that the orientation of collagen fibers in the grafted skin matches to the fiber orientation in surrounding skin. There have been, to my best knowledge, no methods for determining the orientation of collagen fibers in the skin from the clinical point of view. Recently, the author has found a new method for directly determining the collagen-fiber orientation without cutting samples from a calf leather by analyzing the anisotropic shape of hair pore. Its principle is based on the quantitative evaluation of collagen-fiber orientation by approximating a hair pore to an ellipse. The results obtained by the new method using hair pores were supported by the microwave method, mechanical measurements and scanning electron microscopy. Such a method will be applicable for determining the orientational distribution of collagen fibers in skins of animals and humans and give a valuable probe for performing skin grafting based on the scientific data of hair pores.

Animals↗
PubMed1985

The continuing education activity of allied health professionals. Part 2) Motivational orientations for participation.

The purposes of this study were to determine 1) the extent to which selected groupings of allied health professionals differed in their orientations toward engaging in continuing education (CE), and 2) the utility of these orientations in predicting differences in their CE participation. A cross-sectional survey design gathered pertinent descriptive information and data on levels of participation in and orientations toward CE from individuals representing three major allied health occupational clusters. Observed differences in motivational orientations among subgroups of the sample suggest that a general shift from pragmatic purposes for participation to less utilitarian motives occurs as these personnel advance within their career lines. Moreover, the utility of these orientations in predicting CE participation was observed to vary substantially across the disciplines studied. An understanding of the perceived importance and predictive utility of allied health professionals' orientations toward participation can facilitate decision-making by those involved in both CE planning and policy formulation.

Allied Health Personnel↗
PubMed1992

Chromosome mal-orientation and reorientation during mitosis.

We argue that mal-orientation of mitotic chromosomes is not as rare as once believed. However, unlike bivalents during meiosis I, the reorientation of a mal-oriented mitotic chromosome has yet to be observed. This appears to be due, in part, to the difficulty in differentiating mal-oriented chromosomes from mono-oriented ones which are common during spindle formation in living mitotic cells. We assume that mitotic cells possess mechanisms for correcting chromosome mal-orientations that are similar to those operating during meiosis. However, unlike meiosis, where reorientation appears to be triggered when tension on a K-fiber is relieved or reduced, other factors related to the close proximity of sister kinetochores may also induce reorientation in mal-oriented mitotic chromosomes. We favor a model in which the reorientation of a mitotic kinetochore depends on, and is initiated by, the kinetochore capturing MTs from the pole to which it is reorienting.

Animals↗
PubMed2006

Aligned neurite bundles of granule cells regulate orientation of Purkinje cell dendrites by perpendicular contact guidance in two-dimensional and three-dimensional mouse cerebellar cultures.

To identify structures that determine the 90 degree orientation of thin espalier dendritic trees of Purkinje cells with respect to parallel fibers (axonal neurite bundles of granule cells) in the cerebellar cortex, we designed five types of two-dimensional and three-dimensional cell and tissue cultures of cerebella from postnatal mice and analyzed the orientation of Purkinje cell dendrites with respect to neurite bundles and astrocyte fibers by immunofluorescence double or triple staining. We cultured dissociated cerebellar cells on micropatterned substrates and preformed neurite bundles of a microexplant culture two-dimensionally and in matrix gels three-dimensionally. Dendrites, but not axons, of Purkinje cells extended toward the neurites of granule cells and oriented at right angles two-dimensionally to aligned neurite bundles in the three cultures. In a more organized explant proper of the microexplant culture, Purkinje cell dendrites extended toward thin aligned neurite bundles not only consistently at right angles but also two-dimensionally. However, in the "organotypic microexplant culture," in which three-dimensionally aligned thick neurite bundles mimicking parallel fibers were produced, Purkinje cell dendrites often oriented perpendicular to the thick bundles three-dimensionally. Astrocytes were abundant in all cultures, and there was no definite correlation between the presence of and orientation to Purkinje cell dendrites, although their fibers were frequently associated in parallel with dendrites in the organotypic microexplant culture. Therefore, Purkinje cells may grow their dendrites to the newly produced neurite bundles of parallel fibers in the cerebellar cortex and be oriented at right angles three-dimensionally mainly via "perpendicular contact guidance."

Animals↗
PubMed1991

Complementary global maps for orientation coding in upper and lower layers of the cat striate cortex and their possible functions.

Preferred stimulus orientations of striate cortical cells in the cat were analyzed for possible isotropic or anisotropic distributions. We separated the data twice, into central (0-5 degrees) vs. peripheral subgroups and into upper vs. lower layer cells. In the central group, absolute orientations were counted; in the periphery, a radial test was adopted by normalizing the preferred stimulus orientation of a cell to the line connecting the receptive field center to the retinal center. We found that in the center, vertical and horizontal orientations are overrepresented. In the periphery, the histograms show complementary anisotropies for upper and lower layers, favoring a map for radial orientation detection in upper layers and a more concentric map for orientation detection in lower layers. These results are possibly related to the probabilities of different optic flow fields on the retina under natural conditions of stimulation. They are discussed as possible neuronal structures supporting figure-ground discrimination, the distinction of self motion from object motion, and the location of objects in three-dimensional space.

Animals↗
PubMed2004

Rotor modulations and recoupling strategies in 13C solid-state magic-angle-spinning NMR spectroscopy: probing molecular orientation and dynamics.

Recoupling strategies for anisotropic interactions enable the investigation of molecular structure, order and dynamics in a sensitive and site-specific fashion by solid-state NMR spectroscopy. Whereas magic-angle spinning (MAS) efficiently averages anisotropic interactions and enhances spectral resolution, recoupling pulse sequences selectively restore certain parts of rotor-modulated dipole-dipole couplings or chemical shift anisotropies (CSA). More specifically, it is possible to recouple either the omegaR- or the 2omegaR-modulated terms of an interaction Hamiltonian, which exhibit different orientation dependencies and, in this way, provide a means of distinguishing whether the observed NMR spectra are affected by molecular motion or by molecular orientation. Sideband patterns generated by reconversion rotor encoding allow for a precise and selective determination of coupling constants and anisotropies, which contain site-specific information on structure, orientation and/or dynamics of individual molecular segments. Corresponding recoupling schemes are presented in a common context, and the possibilities of exploiting these effects for the determination of order parameters of oriented materials, such as oriented polymer chains or extruded fibres of a discotic mesogen, are discussed. The obtained orientational order parameters are compared to results from two-dimensional wide angle X-ray scattering (WAXS).

Algorithms↗
PubMed2005

The effect of integrated emotion-oriented care versus usual care on elderly persons with dementia in the nursing home and on nursing assistants: a randomized clinical trial.

OBJECTIVES: To examine the effect of integrated emotion-oriented care on nursing home residents with dementia and nursing assistants. DESIGN: A multi-site randomized clinical trial with matched groups, and measurements at baseline and after seven months. SETTING: Sixteen psychogeriatric wards in fourteen nursing homes in the Netherlands. PARTICIPANTS: One hundred and forty-six elderly residents with the diagnosis dementia of the Alzheimer (DAT) type, mixed DAT and vascular dementia, and dementia syndrome (NAO) and 99 nursing assistants. INTERVENTIONS: Integrated emotion-oriented care and usual care. MESUREMENTS: Demented elderly: Behaviour and mood related to adaptation to the illness and the institutionalization. Nursing assistants: General health as measured by feelings of stress, stress reactions, feeling of competence and illness. RESULTS: Positive effects in favour of the integrated emotion-oriented care were found in mild to moderately demented residents on two adaptive tasks: maintaining an emotional balance (less anxiety) and preserving a positive self-image (less dissatisfaction). In the trained group of nursing assistants fewer stress reactions were found only in those who perceived improvement in their emotion-oriented care skills after training. CONCLUSION: Emotion-oriented care is more effective with regard to the emotional adaptation in nursing homes of persons with a mild to moderate dementia. For the severely demented elderly we did not find this surplus value. This outcome is of clinical importance for elderly persons with dementia who are cared for in nursing homes. With respect to the nursing assistants it is concluded that emotion-oriented care has a positive influence on stress reactions in some of them.

Absenteeism↗
PubMed2003

Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin-related peptides.

Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH(3) terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin-related (BRP-A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP-A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP-A was quantified using (125)I-FN, and monoclonal antibodies. (125)I-FN was used to quantitate FN binding to peptide-coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP-A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti-C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti-N terminus antibodies to peptide-bound FN occurred. We believe that the data that indicate an enhanced binding of anti-C antibodies reactive to anti-N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP-A on the polystyrene surface.

Adhesins, Bacterial↗
PubMed1984

Impaired motility of neonatal PMN leukocytes: relationship to abnormalities of cell orientation and assembly of microtubules in chemotactic gradients.

To allow a further understanding of the pathogenesis of impaired stimulated locomotion by polymorphonuclear leukocytes (PMNs) in human neonates, we studied cellular orientation by neonatal PMNs in response to well-defined chemotactic gradients (Zigmond orientation chambers) and characterized the cytoplasmic microtubule (MT) complex of neonatal PMNs during cell orientation and movement. PMN suspensions obtained from 52 neonates demonstrated a diminished capacity to undergo orientation at all time intervals after exposure to gradients of N-formyl-methionyl-leucyl phenylalanine (f-Met-Leu-Phe) or C5a. Among responding (orienting) neonatal PMNs observed, only 70% (f-Met-Leu-Phe) or 59% (C5a) oriented accurately (toward chemotactic gradients) as compared to values of 96% (f-Met-Leu-Phe) or 92% (C5a) for adult controls. Furthermore, neonatal PMNs failed to alter their direction of orientation/migration when chemotactic gradients were reversed. Similar abnormalities were observed when 10-fold gradients of f-Met-Leu-Phe were employed over a concentration range between 10(-7) and 10(-11) M. Employing tubulin immunofluorescence, the cytoplasmic MT complex of-neonatal PMNs was assessed prior to and after cell exposure to uniform concentrations or gradients of chemotactic factors (CFs). MT assembly by neonatal PMNs studied under these experimental conditions was significantly diminished. Neonatal cell suspensions demonstrated 26 +/- 5 (f-Met-Leu-Phe) or 27 +/- 6 (C5a) MT/cell as compared to respective values of 36 +/- 6 or 35 +/- 5 for adult suspensions (P less than .001). MT lengths of neonatal PMNs increased from 6.7 +/- 1 micron (PBS) to 7.5 +/- 1 micron (f-Met-Leu-Phe) or 7.3 +/- 1 micron (C5a) as compared to values of 6.5 +/- 1 micron (PBS), 11.1 +/- 1 micron (f-Met-Leu-Phe), and 10.9 +/- 1 micron (C5a) for adult PMNs exposed to gradients or uniform concentrations of CFs (P less than .01 for both f-Met-Leu-Phe and C5a). Thus, the polymerized tubulin mass product of chemotactically stimulated neonatal PMNs (202 micron) was significantly (P less than .001) diminished as compared to adult PMNs (360 micron). As shown by a [3H]colchicine binding assay, impaired MT assembly could not be attributed to diminished cytoplasmic tubulin content of neonatal PMNs, which was comparable to adult PMNs.

Chemotaxis, Leukocyte↗
PubMed2004

Sensitivity of femoral orientation estimates to condylar surface and MR image plane location.

PURPOSE: To define the femoral anatomic region that provides the most reliable reference for measuring femoral orientation, from which patellofemoral and tibiofemoral orientation can be measured. MATERIALS AND METHODS: After a three-dimensional image-based osteo-alignment procedure, two independent estimates of distal femoral orientation, the anterior (AFA) and posterior femoral angles (PFA), were acquired. These sets were comprised of 31 axial femoral orientation estimates each (obtained across a region 10 mm above to 20 mm below the patellar center) from 42 normal axial magnetic resonance (MR) image sets. An analysis of variance was conducted to determine the influence of image plane location, sex, and side on femoral orientation measures. RESULTS: The AFA presented greater variability across subjects (average SD = 3.13 degrees) as compared to the PFA (average SD = 1.78 degrees ). There were significant differences in the AFA based on image plane location and sex. In contrast, no differences were found between sides, sexes, or image plane locations for the PFA. CONCLUSION: In total, the posterior femoral condylar surface is more reliable than the anterior condylar surface for measuring femoral orientation and is best measured at least 8 mm below the patellar center.

Adult↗
PubMed2006

Subthalamic nucleus influences spatial orientation in extra-personal space.

While the role of frontal and parietal cortex in spatial orientation has been studied extensively, the contribution of the basal ganglia and especially the subthalamic nucleus to spatial orientation remains less clear. Here we use subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) as a reversible model of functional lesioning to evaluate the influence of the STN in extra-personal space orientation. To this end, 12 PD patients were examined 1 year after implantation of DBS electrodes in the STN after overnight withdrawal of L-dopa. Patients were tested in a pseudo-randomized order while both stimulators, the right only, the left only, or no stimulator, were switched on. Patients performed line bisection and a reaction time task responding to stimuli of the middle, the left, and the right extra-personal space. A separate assessment of the right and left hand responding to visual stimuli in each hemispace made it possible to distinguish hemi-spatial and hemi-motor impairments. No asymmetries in space orientation were found when both stimulators were switched OFF, when both stimulators were switched ON, and when only the right stimulator was switched ON. When only the left subthalamic stimulation was switched ON, the reaction times of both hands to visual stimuli in the left extra-personal hemispace increased significantly and the line bisection test showed a significant orientation to the right. These results lead to the conclusion that the STN and its cortical projections influence the network involved in visuospatial orientation. These patterns of symptoms of neglect demonstrate the influence of the STN on the attentional system of the nondominant hemisphere.

Attention↗
PubMed1987

Power orientations and communication style of managers and nonmanagers.

The purpose of this study was to compare nurse managers and nonmanagers in their orientations to power and in their communication styles. A complementary purpose was to examine the relationship between six orientations to power and social style. Forty-seven hospitals were randomly selected with 43 used for analysis. The director of nursing and a staff nurse from each hospital were asked to complete the Power Orientation Scale and to obtain ratings from others on their social style. Nurse administrators held more positive orientations to three of the six power orientations, and were perceived to communicate more assertively than staff nurses. Negative correlations were found between four of the power orientations and two dimensions of social style.

Administrative Personnel↗
PubMed2002

Morphometry of dermal collagen orientation by Fourier analysis is superior to multi-observer assessment.

In human dermis, collagen bundle architecture appears randomly organized, whereas in pathological conditions, such as scar tissue and connective tissue disorders, collagen bundle architecture is arranged in a more parallel fashion. Histological examination by one or two observers using polarized light is the most common method to determine collagen orientation. The hypothesis on which this study is based is that an objective image analysis technique, Fourier analysis, would improve the reliability (are the measurements reproducible?) and the accuracy (does the method measure what it is supposed to measure?) of collagen orientation assessment, compared with observer ratings. Fourier analysis was applied to 271 images of scar tissue and normal skin that were acquired by confocal laser-scanning microscopy. Observers rated the same areas using polarized light as well as the confocal microscopy images. Computer images consisting of different types of ellipses were generated with a fixed orientation. Observers and Fourier analysis evaluated the images to evaluate accuracy. The inter-observer reliability was acceptable when at least three observers rated polarized light images (r > 0.69), whereas two observers were sufficient for rating confocal microscopy images (r > 0.71). Fourier analysis correlated better with observer ratings of confocal microscopy images (r = 0.69) than with polarized light microscopy images (r = 0.42). Fourier analysis was more accurate than four observers for the evaluation of the 'true' orientation for almost all types of computer-generated images. For the first time it is shown that Fourier image analysis is suitable for the morphometry of dermal collagen orientation and leads to a superior measurement of collagen orientation compared with subjective histological evaluation by several experts. If an evaluation is performed by conventional light microscopy, at least three observers are required to attain an acceptable inter-observer reliability.

Adult↗
PubMed2005

Ethnicity and the need for correction of biochemical and ultrasound markers of chromosomal anomalies in the first trimester: a study of Oriental, Asian and Afro-Caribbean populations.

OBJECTIVES: To assess whether there is a need to correct first-trimester biochemical markers (free beta-hCG and pregnancy-associated plasma protein-A (PAPP-A)) or first-trimester fetal nuchal translucency thickness (NT) in different ethnic groups, when screening for Downs syndrome at 11-14 weeks of gestation. METHODS: Free beta-hCG, PAPP-A and fetal NT were measured at 11-14 weeks of gestation in a group of women presenting for first-trimester screening in two OSCAR centres. The group comprised 61 219 sets of data from Caucasian women (the reference group); 4835 sets of data from South Asian women; 3450 sets of data from Oriental women and 2727 sets of data from Afro-Caribbean women. The Oriental data set was supplemented with a further 480 cases collected in Hong Kong and the Afro-Caribbean data set was supplemented with 216 cases collected from Kings College. The difference in marker values between the reference group and the other ethnic groups was compared before and after weight correction for the biochemical markers using standard statistical techniques. A correction factor for ethnic origin was applied for all three markers and the screen-positive rate before and after correction was assessed for the various groups. RESULTS: After maternal weight correction, in Afro-Caribbean women, the median PAPP-A was increased by 55% and the free beta-hCG increased by 11%. In south Asian women, the PAPP-A was increased by 8% and the free beta-hCG decreased by 7.5%. In Oriental women, the PAPP-A was increased by 9% and the free beta-hCG by 6%. For delta NT in Afro-Caribbean women, the values were 0.064 mm lower on average than in Caucasian women and for south Asian women 0.045 mm lower. The difference of -0.012 for Oriental women was not significant. Before correcting for ethnic origin, these changes resulted in the screen-positive rates being lower in the Afro-Caribbean group (3.7% vs 5.6%), the south Asian group (4.3% vs 5.6%) and Oriental group (4.9% vs 5.6%). After correction, the screen-positive rates were largely similar in the four groups. CONCLUSION: Differences in median PAPP-A, free beta-hCG and, to a lesser extent, in NT exist in Afro-Caribbean, South Asian and Oriental women. In populations where the medians and delta NT reference ranges are established in predominantly Caucasian populations, some correction for ethnicity is appropriate and can redress differences in screen-positive rates between these different groups.

Adult↗
PubMed2005

How do side chains orient globally in protein structures?

An angle Omega is defined to serve as a metric for global side-chain orientations, which reflects the orientation of the side chain relative to the radial vector from the center of the protein to an amino acid. The side-chain orientations of buried residues exhibit characteristically different orientations than do exposed residues, in both monomeric and dimeric structures. Overall, buried side chains point mostly inward, whereas surface side chains tend to point outward from the surface. This difference in behavior also correlates well with the residue hydrophobicity; so a global side-chain orientation can be viewed as a direct structural manifestation of hydrophobicity. When various solvent-accessible layers are considered, the behavior is relatively continuous between centrally located and exposed residues. In the case of interfacial residues between subunits, there are statistically significant differences between exposed residues and interface residues for ALA, ARG, ASN, ASP, GLU, HIS, LYS, THR, VAL, MET, PRO, and overall the interface residues have an increased tendency to point inward. Presumably, these substantial differences in orientations of side chains may be a manifestation of hydrophobic forces.

Amino Acids↗
PubMedDate not supplied

Lactam bridge stabilization of alpha-helical peptides: ring size, orientation and positional effects.

A series of 14 residue amphipathic alpha-helical peptides, in which the sidechains of glutamic acid and lysine have been covalently joined, was synthesized in order to determine the effect of spacing, position and orientation of these lactam bridges. It was found that although an (i, i+3) spacing would position the lactam bridge on the same face of the helix, these lactams with 18-member rings were actually helix-destabilizing regardless of position or location. On the other hand, (i, i+4) lactams with 21-member rings were helix-stabilizing but this was dependent on orientation. Glutamic acid-lysine lactams increased the helical content of the peptide when compared with their linear homologue in benign conditions (50 mM KH2PO4, 100 mM KCl, pH 7). Two Glu-Lys (i, i+4) lactams located at the N- and C-termini gave rise to a peptide with greater than 99% helical content in benign conditions. Peptides with Lys-Glu oriented lactams were random structures in benign conditions but in the presence of 50% TFE could be induced into a helical conformation. The stability of the single-stranded alpha-helices, as measured by thermal denaturations in 25% TFE indicated that Glu-Lys oriented lactam bridges stabilized the helical conformation relative to the linear unbridged peptide. One Glu-Lys lactam in the middle of the peptide was more effective at stabilizing helical structure than two Glu-Lys lactams positioned one at each end of the molecule. The lactams with the Lys-Glu orientation were destabilizing relative to the unbridged peptide. This study demonstrates that correct orientation and position of a lactam bridge is critical in order to design peptides with high helical content in aqueous media.

Amino Acid Sequence↗
PubMed1999

Patterns of movement and orientation during caching and recovery by Clark's nutcrackers, Nucifraga columbiana.

Clark's nutcrackers regularly store large numbers of pine seeds and remember the locations of the cached seeds. Although they are very accurate, they do make some errors during recovery. In an attempt to determine whether any behaviours during caching predicted the occurrence of errors during recovery, we videotaped Clark's nutcrackers while they cached and recovered seeds under laboratory conditions. We used the videotapes to develop complete, quantitative descriptions of caching and recovery behaviour, with an emphasis on body orientation and directions of movement. During caching, the birds showed the greatest change in their orientation and direction following cache creation. During cache recovery, in contrast, body orientation changed most following successful recovery of a seed. When orientation while making a cache was compared with orientation when recovering the same cache, orientations were similar more often than would be expected by chance. However, this consistency of direction was not related to the accuracy of cache recovery, indicating that such consistency is not necessary for accurate cache recovery. The location in which the birds chose to place their caches was the only variable that predicted the location of probes during recovery. Copyright 1999 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Conceptions of success: their correlates with prosocial orientation and behaviour in Chinese adolescents.

Data from a sample of 673 Chinese adolescents lent support to the hypothesis that conceptions of success or achievement goals affect both the inclination to and the actual performance of prosocial acts. With regard to attitude, it was found that: (a) task orientation (belief that success is gaining skill or understanding) and collaboration orientation (belief that success is working productively with one or more collaborators) increased with the inclination to help others, to co-operate and share things with others, to maintain an affective relationship with others, and to behave in compliance with social norms; and (b) ego orientation (belief that success is establishing one's competence as superior) was not generally associated with the inclination to perform prosocial acts. With regard to action, it was found that task orientation and collaboration orientation, but not ego orientation, increased with the number of normative and altruistic acts in the past year. The similarity between the belief-attitude correlation and the belief-action correlation indicates the robustness of the influence of conceptions of success. Also, sex differences and grade differences in the relationship between conceptions of success and prosocial and antisocial behaviours were found. Implications of the findings are discussed.

Achievement↗