Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Body Patterning”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources
PubMed2006

The effects of unilateral grab rail assistance on the sit-to-stand performance of older aged adults.

This study investigated the effects of unilateral grab rail assistance during the sit-to-stand transfer to develop an understanding of lower limb joint mechanics and whole body movement patterns. External reaction forces at the grab rail and floor interfaces were also investigated to understand the nature of the assistance provided by the introduction of unilateral upper body assistance. While 12 older aged adults performed the sit-to-stand, three-dimensional body segment kinematics were recorded to determine lower body joint motion and whole body centre of mass motion. Grab rail reaction forces and bilateral ground reaction forces were recorded to determine external reaction forces and lower body joint kinetics. Grab rail assisted conditions were compared with unassisted transfers. During grab rail assistance, a systematic asymmetry was introduced to lower limb joint kinetics, without noticeable alterations to peak lower body joint motion and whole body movement patterns. Ipsilateral net joint moments and powers decreased in the ankle and hip and increased in the knee, while the contralateral net joint moments and powers increased in the hip and decreased in the knee. Joint kinetic and kinematic responses suggest a motor control strategy that maintains symmetric sit-to-stand movement patterns by adjusting bilateral muscle control when a unilateral external reaction force is provided. Understanding the mechanical assistance that is generated during the sit-to-stand will facilitate optimal design of grab rails for older aged adults and may contribute to design for specific pathologies. Such design implementation will influence the ability of older aged adults to remain independent in the community.

Activities of Daily Living↗
PubMed1980

Topographic distribution pattern of Lafora-like bodies in the spinal cord of some animals.

The topographic distribution pattern and morphological features of Lafora-like bodies in the spinal cord of the dog, cat, fox, and baboon were examined by light and electron microscopy. The caudal lumbar and the coccygeal parts of the spinal cords were the predilection sites for the bodies in all animals and were very prominent in the ventral columns and intermediate substance. The bodies mainly composed of branching filaments were preferentially located in neuronal processes and rarely in astocytes. The histochemical characteristics of the bodies were identical in all animals and consisted mainly of polyglucosan.

Animals↗
PubMed2004

Body size of insular carnivores: little support for the island rule.

Large mammals are thought to evolve to be smaller on islands, whereas small mammals grow larger. A negative correlation between relative size of island individuals and body mass is termed the "island rule." Several mechanisms--mainly competitive release, resource limitation, dispersal ability, and lighter predation pressure on islands, as well as a general physiological advantage of modal size--have been advanced to explain this pattern. We measured skulls and teeth of terrestrial members of the order Carnivora in order to analyze patterns of body size evolution between insular populations and their near mainland conspecifics. No correlations were found between the size ratios of insular/mainland carnivore species and body mass. Only little support for the island rule is found when individual populations rather than species are considered. Our data are at odds with those advanced in support of theories of optimal body size. Carnivore size is subjected to a host of selective pressures that do not vary uniformly from place to place. Mass alone cannot account for the patterns in body size of insular carnivores.

Adaptation, Physiological↗
PubMed2005

Retinoic acid coordinates somitogenesis and left-right patterning in vertebrate embryos.

A striking feature of the body plan of a majority of animals is bilateral symmetry. Almost nothing is known about the mechanisms controlling the symmetrical arrangement of the left and right body sides during development. Here we report that blocking the production of retinoic acid (RA) in chicken embryos leads to a desynchronization of somite formation between the two embryonic sides, demonstrated by a shortened left segmented region. This defect is linked to a loss of coordination of the segmentation clock oscillations. The lateralization of this defect led us to investigate the relation between somitogenesis and the left-right asymmetry machinery in RA-deficient embryos. Reversal of the situs in chick or mouse embryos lacking RA results in a reversal of the somitogenesis laterality defect. Our data indicate that RA is important in buffering the lateralizing influence of the left-right machinery, thus permitting synchronization of the development of the two embryonic sides.

Aldehyde Oxidoreductases↗
PubMed1998

Zebrafish organizer development and germ-layer formation require nodal-related signals.

The vertebrate body plan is established during gastrulation, when cells move inwards to form the mesodermal and endodermal germ layers. Signals from a region of dorsal mesoderm, which is termed the organizer, pattern the body axis by specifying the fates of neighbouring cells. The organizer is itself induced by earlier signals. Although members of the transforming growth factor-beta (TGF-beta) and Wnt families have been implicated in the formation of the organizer, no endogenous signalling molecule is known to be required for this process. Here we report that the zebrafish squint (sqt) and cyclops (cyc) genes have essential, although partly redundant, functions in organizer development and also in the formation of mesoderm and endoderm. We show that the sqt gene encodes a member of the TGF-beta superfamily that is related to mouse nodal. cyc encodes another nodal-related proteins, which is consistent with our genetic evidence that sqt and cyc have overlapping functions. The sqt gene is expressed in a dorsal region of the blastula that includes the extraembryonic yolk syncytial layer (YSL). The YSL has been implicated as a source of signals that induce organizer development and mesendoderm formation. Misexpression of sqt RNA within the embryo or specifically in the YSL induces expanded or ectopic dorsal mesoderm. These results establish an essential role for nodal-related signals in organizer development and mesendoderm formation.

Amino Acid Sequence↗
PubMed2007

Nondestructive micro-patterning of proteinous occlusion bodies in water by femtosecond laser-induced mechanical force.

Some insect virus produces proteinous occlusion bodies named polyhedra, on which it is possible to immobilize functional proteins, such as green fluorescent proteins, antibodies, and growth factors, with keeping their biological activity. In this work, several kinds of polyhedra were micro-patterned by applying a mechanical force induced by femtosecond laser irradiation of a water buffer. In the printing process, since the laser is not directly irradiated on polyhedra, damages of polyhedra due to dryness and photothermal and photochemical reactions will be suppressed. The ability of the pattering was demonstrated by micro-sized checkerboard pattern, on which polyhedra with and without occluding enhanced green fluorescent protein were sorted. Furthermore, it was indicated that polyhedra are available as a scaffold of animal cell. This patterning method will be a promising technique to realize a microdevice in which functions of cell are artistically activated.

Animals↗
PubMed2001

The daily pattern of heart rate, body temperature, and locomotor activity in guinea pigs.

We studied the characteristics of the rhythmicity of heart rate (HR), body temperature (BT), and locomotor activity (LA) in conscious and unrestrained guinea pigs using a telemetry system. HR and/or LA in some guinea pigs clearly showed circadian rhythms, but in others there were no significant daily patterns; BT did not show significant daily rhythms. These results suggest that guinea pigs might have different individual characteristics of rhythmicity, and we should, therefore, be careful when using guinea pigs in chrono-biomedical research. We believe that the results of this study may be useful for future biomedical studies using guinea pigs.

Animals↗
PubMed2001

Inhomogeneity of human vertebral cancellous bone: systematic density and structure patterns inside the vertebral body.

In the spine, cancellous bone quality is usually assessed for the whole vertebral body in a transverse central slice. Correct identification and assessment of the weakest parts of the cancellous bone may lead to better prediction of fracture risk. The density and structural parameters were systematically investigated inside the thoracic (T-9), thoracolumbar (T12-L1), and lumbar (L-4) vertebral bodies of nine subjects. On both sides of the median sagittal plane, anterior and posterior 8.2 mm vertical cores were harvested in the thoracic vertebra. In the thoracolumbar and lumbar vertebrae, external samples were also cored. Peripheral quantitative computed tomographic (pQCT) density analysis of the 136 cores was performed at four different levels, from the lower to the upper endplate. The relatively thin slice thickness (300 microm) and small pixel size (70 microm x 70 microm) was considered sufficient to investigate the structural parameters on the four transverse slices and in the sagittal and coronal planes (total of 816 images). Using a constant threshold a binary image was generated and the morphometric data were extracted. The binary image was further skeletonized and classical strut analysis was performed. Cancellous bone density was 20% higher in the posterior cores than in the anterior and external cores. Moreover, clear vertical inhomogeneity was noted because the lowest half of the vertebral body presented lower density than the upper half (differences ranging from 25% to 15%). All structural parameters were strongly dependent on the location of the measurement. Structural differences between anterior, posterior, and external areas were mild and followed the density patterns. On the other hand, vertical inhomogeneity of the structural parameters was important. For example, in the thoracolumbar and lumbar vertebrae, the numbers of nodes or node-to-node struts were almost twofold higher in the inferior half than in the superior half (p < 0.01), whereas trabecular thickness and number of free-ends presented a center/close-to-endplate structural pattern, with central trabeculae being 15% thicker (p < 0.05) and presenting 30% fewer free-ends (p < 0.01) than the close-to-endplate ones. Variability of density and structural parameters was high and a substantial part of this variability could be explained by the place inside the vertebral body where the measurement was made. The weak part was not in the center of the body but in its upper half where the lower density did not seem to be compensated by a higher structural architecture. Further clinical investigation could enhance fracture prediction by tracking and focusing on the weakest part of the vertebral body.

Adult↗
PubMed1989

Organization of posture controls: an analysis of sensory and mechanical constraints.

We analyse two components of posture control in standing human subjects: (1) the mechanical properties which constrain the body's ability to execute stabilizing postural movements and (2) the mechanical and neural properties which constrain the ability of the vestibular system to sense changes in body orientation. Rules are then proposed to describe the central organization of posture controls within the sensory and mechanical constraints. The organizational rules and knowledge of constraints are combined to predict the effects of selective semicircular canal and utricular otolith lesions on postural stability and the patterns of body and head movements used to maintain balance. Our analysis leads to the prediction that semicircular canal and otolith deficits destabilize patients at different frequencies, and force them to use different patterns of body and head movements. These predictions are compared to posture controls observed in patients with different types of vestibular deficits. The additional steps required to prove or disprove the theory are discussed.

Humans↗
PubMed2005

An imaging study of body composition including lipodeposition pattern in a patient of familial partial lipodystrophy (Dunnigan type).

Familial Partial Lipodystrophy, Dunnigan type (FPLD), is characterised by loss of subcutaneous fat from the limbs and an excessive accumulation of fat on the neck, shoulder girdle and face. Affected individuals have insulin resistance, dyslipidaemia and early cardiovascular events. Body composition (BC) with details of adipose tissue distribution were studied by Dual-Energy X-ray Absorptiometry (DEXA) and Magnetic Resonance Imaging (MRI) ina heterozygote for the FPLD mutation LMNA R482W, and in an age, sex and body mass index (BMI) matched normal control. DEXA revealed a marked decrease in total as well as regional fat percentage in the patient compared to a normal control. Marked reductions in subcutaneous fat in the extremities with substantial lipodeposition in the nape of the neck were confirmed with. MRI. The importance of increased perinephric, retroperitoneal and intermuscular fat in the thighs found in this patient, needs to be explored vis-à-vis the pathogenesis of insulin resistance found in FPLD.

Absorptiometry, Photon↗
PubMed2003

Metabonomics: NMR spectroscopy and pattern recognition analysis of body fluids and tissues for characterisation of xenobiotic toxicity and disease diagnosis.

Global profiling tools are required to fully understand the impact of genetic modifications and toxicological interventions on the network of transcripts, proteins and metabolites found within a cell, tissue or organism. High-resolution 1H NMR spectroscopy in conjunction with statistical pattern recognition is one such technique, referred to as metabonomics or metabolomics, which is increasingly being used to globally profile metabolites. This review examines analytical advances in NMR spectroscopy that have aided this development including high-resolution magic angle spinning NMR spectroscopy, cryogenically cooled probes and high-through put systems. This has allowed the approach to identify genetically modified yeast strains and distinguish both disease presence and severity in coronary heart disease.

Adipose Tissue↗
PubMed2005

Postnatal cerebellar defects in mice deficient in methylenetetrahydrofolate reductase.

Patients with severe deficiency of methylenetetrahydrofolate reductase (MTHFR) suffer from a wide variety of neurological problems, which can begin in the neonatal period. MTHFR is a critical enzyme in folate metabolism; the product of the MTHFR reaction, 5-methyltetrahydrofolate, is required for homocysteine remethylation to methionine and synthesis of S-adenosylmethionine (SAM). To understand the mechanisms by which MTHFR deficiency leads to significant neuropathology, we examined early postnatal brain development in mice with a homozygous knockout of the Mthfr gene. These mice displayed a dramatically reduced size of the cerebellum and cerebral cortex, with enlarged lateral ventricles. Mthfr deficiency affected granule cell maturation, but not neurogenesis. Depletion of external granule cells and disorganization of Purkinje cells were mainly confined to the anterior lobules of mutant cerebella. Decreased cellular proliferation and increased cell death contributed to the granule cell loss. Reduced expression of Engrailed-2 (En2), Reelin (Reln) and inositol 1,4,5-triphosphate receptor type 1 (Itpr1) genes was observed in the cerebellum. Supplementation of Mthfr(+/-) dams with an alternate methyl donor, betaine, reduced cerebellar abnormalities in the Mthfr(-/-) pups. Our findings suggest that MTHFR plays a role in cerebellar patterning, possibly through effects on proliferation or apoptosis.

Animals↗
PubMed2005

Siliceous spicules in marine demosponges (example Suberites domuncula).

All metazoan animals comprise a body plan of different complexity. Since--especially based on molecular and cell biological data--it is well established that all metazoan phyla, including the Porifera (sponges), evolved from a common ancestor the search for common, basic principles of pattern formation (body plan) in all phyla began. Common to all metazoan body plans is the formation of at least one axis that runs from the apical to the basal region; examples for this type of organization are the Porifera and the Cnidaria (diploblastic animals). It seems conceivable that the basis for the formation of the Bauplan in sponges is the construction of their skeleton by spicules. In Demospongiae (we use the model species Suberites domuncula) and Hexactinellida, the spicules consist of silica. The formation of the spicules as the building blocks of the skeleton, starts with the expression of an enzyme which was termed silicatein. Spicule growth begins intracellularly around an axial filament composed of silicatein. When the first layer of silica is made, the spicules are extruded from the cells and completed extracellularly to reach their the final form and size. While the first steps of spicule formation within the cells are becoming increasingly clear, it remains to be studied how the extracellularly present silicatein strings are formed. The understanding of especially this morphogenetic process will allow an insight into the construction of the amazingly diverse skeleton of the siliceous sponges; animals which evolved between two periods of glaciations, the Sturtian glaciation (710-680 MYA) and the Varanger-Marinoan ice ages (605-585 MYA). Sponges are--as living fossils--witnesses of evolutionary trends which remained unique in the metazoan kingdom.

Animals↗
PubMed1981

Investigation of cell patterning in the asexual fruiting body of Dictyostelium discoideum using haploid and isogenic diploid strains.

The cell patterning (proportion of spores, stalk cells, and basal disk cells) of individual asexual fruiting bodies of haploid and isogenic diploid strains of D. discoideum was examined to test the hypothesis that the patterning mechanism is based on the 'sensing' of only a single parameter, e.g., cell volume, in dividing the aggregate into the three cell types. If cell patterning is based on sensing only a single parameter, there is no reason to predict a change in cell patterning with ploidy change, and thus haploid and isogenic diploid strains should not differ in their cell patterning. The cell patterning of each of the three pairs of haploid and isogenic diploid strains examined was different. Therefore we conclude that the cell patterning mechanism must involve at least two components not changing in the same way with change in ploidy. The cell patterning of both the haploid and the diploid strains was qualitatively similar, i.e., relationships between the three cell types were described by equations of the same form in the haploid and diploid strains. However a quantitative change in cell patterning led to an increased percentage of stalk and basal disk cells in each diploid compared to its parent haploid. The ratio of basal disk to stalk cell was also greater in the diploids than in their parent haploids. We conclude that these are general ploidy-related changes because the cell patterning of each of the three parent haploid strains was different; the average percentage of stalk cells was 11.6% for X22 (12.4% for its diploid DU162), 20.5% for NP73 (27.2% for its diploid DP62), and 24.5% for HU127 (29.1% for its diploid DU310). One possible patterning mechanism could involve a diffusible signal (s), which shows gene dosage, interacting with cell-surface molecules which we predict occupy a limited number of sites per unit area of the cell membrane. The observed change in cell patterning leading to an increased percentage of stalk cells in diploid strains is predicted from such a model involving diffusible signal interacting with cell-surface molecules.

Cell Aggregation↗
PubMed1983

Cortisol suppression and circadian rhythm in endogenous depression: a preliminary report.

We studied the relationships between dexamethasone challenge (DST), 36-hr sleep deprivation (SD), and body temperature patterns in ten male endogenous depressives. Seven of the ten depressives were pre-SD DST non-suppressors, and five of the ten patients improved following SD. All five SD responders were pre-SD DST non-suppressors. Pre- and post-SD 12-hr daytime body temperature patterns defined three subgroups of depressives. SD responders with DST non-suppression showed a normal diurnal temperature pattern on both pre- and post-sleep deprivation. SD non-responders with DST non-suppression showed a diurnal variation, but time of maximum temperature value was phase-advanced before SD and delayed after SD. SD non-responders with DST suppression had a blunted diurnal temperature pattern on both pre- and post-SD. We conclude that a normal pre-SD temperature pattern together with pre-SD DST non-suppression may predict clinical response to SD suggesting the possibility of physiologically distinct subgroups of endogenous depressives.

Adult↗
PubMed1990

Size, space, and adaptation in some subfossil lemurs from Madagascar.

We examine several explanations for the geographic pattern of body size variation exhibited by the subfossil lemur Archaeolemur. Part and partial correlation analysis and multiple regression analysis are applied in a stepwise, hierarchical fashion to help to determine variable interdependencies. Variance in site means for body size is best explained by the richness of the plant community and by several correlated climatic variables (bioclimatic zone and mean annual rainfall). Body size differentiation in Archaeolemur roughly mirrors patterns observed among many other Malagasy lemur species and subspecies groups. This consistency alone suggests that common ecological factors have strongly affected size differentiation in lemurs, most probably (as suggested by our correlation analyses) by uniformly influencing the productivity of their niches. Smaller individuals tend to inhabit arid regions, and larger individuals tend to inhabit wetter regions. The interplay between selective differentiation and allopatric speciation appears to have yielded the concordant pattern of size variation observed in Malagasy lemurs.

Adaptation, Biological↗
PubMed2004

LiCl inhibits the establishment of left-right asymmetry in larvae of the direct-developing echinoid Peronella japonica.

The effect of LiCl on the establishment of left-right (LR) asymmetry in larvae of the direct-developing echinoid Peronella japonica was investigated with special attention to the location of the amniotic opening and ciliary band pattern. The larvae of echinoids are LR symmetric, but shortly before metamorphosis the larval LR symmetry is lost as a result of the formation of an amniotic cavity (vestibule), part of the adult rudiment, on the left side of the body. P. japonica has been considered to be the only exception among the echinoids, because the amniotic cavity forms at the midline of the larval body. In the present study we discovered the following two different LR asymmetric traits in larvae of P. japonica: the opening of the amniotic cavity initially forms at the midline of the larval body but shifts to the left dorsal side, and a looped ciliary band that initially forms with LR symmetry becomes LR asymmetric as a result of the formation of a bulge on left dorsal side. The establishment of LR asymmetry in both the location of the amniotic opening and the change in the shape of the ciliary band was influenced by exposing embryos to LiCl. Quantitative analysis of the shift in amniotic opening showed that exposure of embryos to LiCl causes repression of leftward shifting of the amniotic opening in earlier stage larvae, and leftward or rightward shifting in later stage larvae. These findings suggest that LiCl is an effective means of impairing the establishment of LR asymmetry in sea urchin embryos.

Animals↗
PubMed2002

Leptin resistance during aging is independent of fat mass.

Increased fat mass, abdominal adiposity, and insulin resistance are typical findings in aging mammals and are frequently associated with leptin resistance and increased plasma leptin levels. To examine whether leptin's failure in aging is due to aging per se or to changes in body fat mass or distribution, we studied aging rats that underwent calorie restriction throughout their lives, maintaining their youthful body fat pattern and metabolic profile. Leptin's action was assessed by measuring its ability to regulate food intake, fat mass and its distribution, peripheral and hepatic insulin action, and its own gene expression in fat. Our results show that leptin's action is markedly diminished in aging rats, independently of their body fat pattern. Leptin's failure in this model suggests its causative role in the metabolic decline seen with aging.

Adipose Tissue↗