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 1,027 records · Page 57Linked to original sources
PubMed1993

Nighttime sleep and bed mobility among incontinent nursing home residents.

OBJECTIVE: To describe sleep and body movement patterns in incontinent nursing home residents for the purpose of determining if the residents require nighttime changing and body repositioning on a 2-hour schedule. DESIGN: Cross-sectional survey. SETTING: Four nursing homes. PARTICIPANTS: 118 nursing home residents. MEASUREMENTS: Over two nights, bedside monitoring equipment recorded wrist activity (as a proxy measure for sleep) and body movements of both the shoulder and hip areas in consecutive 2-minute intervals. Specific outcome measures were: (1) Average duration of a sleep episode, peak duration of a sleep episode, and percent of time in bed asleep. (2) The number of 2-minute intervals in which a large movement (45 degree turn) at the shoulder and hip was noted per hour of recording for each resident. (3) The number of resident-initiated, rather than staff-initiated, large movements at the shoulder and hip that occurred within the same 2-minute intervals. RESULTS: There was large variability in all sleep measures; however, on average, residents slept 66% of the time they were in bed. The distribution of these measures suggests that sleep was punctuated with frequent nighttime awakenings. Thirty-three percent of the incontinent residents demonstrated very low levels of resident-initiated movement at the shoulder and hip. Sixty-six percent demonstrated at least one large movement at the shoulder and hip per hour during periods of sleep as well as during periods of wake. CONCLUSION: The majority of incontinent nursing home residents self-initiate sufficiently frequent movements at both the shoulder and hip so as not to be in need of frequent repositioning by nursing staff. Since the sleep of many of these residents is also characterized by frequent awakenings, incontinent nursing home residents may benefit from a schedule of nursing care at night that considers sleep of equal importance to incontinence care and body repositioning.

Aged↗
PubMed1993

Diet and weight changes of female bodybuilders before and after competition.

This study assessed nutritional and body weight patterns in 6 female bodybuilders approximately a month before and after a competition. The women kept dietary and body weight records and two of them also agreed to collect morning urine samples to provide information about their menstrual cycle. All women lost weight before and gained weight after competition. Energy intake was modestly restricted and the subjects consumed a moderate-protein, low-fat, high-carbohydrate diet just prior to competition. Energy intake doubled, and total grams of fat increased approximately tenfold just after competition. Urinary data indicated that the cycle following competition was prolonged, with reduced reproductive hormone concentrations. In summary, the women practiced extreme dietary control while preparing for a competition but followed the event with a higher energy and fat intake. These changes in diet and body weight may contribute to the disturbances previously observed in the menstrual cycle of these athletes.

Adult↗
PubMed2005

Temporal and spatial patterning of an organ by a single transcription factor.

During the formation of animal organs, a single regulatory factor can control the majority of cell-fate decisions, but the mechanisms by which this occurs are poorly understood. One such regulator, the nematode transcription factor PHA-4, functions together with various cis-regulatory elements in target genes to regulate spatial and temporal patterning during development of the pharynx.

Animals↗
PubMed2003

Retinoic acid regulates a subset of Cdx1 function in vivo.

Hox gene products are key players in establishing positional identity along the anteroposterior (AP) axis. In vertebrates, gain or loss of Hox expression along the AP axis often leads to inappropriate morphogenesis, typically manifesting as homeotic transformations that affect the vertebrae and/or hindbrain. Various signalling pathways are known to impact on Hox expression, including the retinoid signalling pathway. Exogenous retinoic acid (RA), disruption of enzymes involved in maintaining normal embryonic RA distribution or mutation of the retinoid receptors (RARs and RXRs) can all impact on Hox expression with concomitant effects on AP patterning. Several Hox loci have well characterized RA response elements (RAREs), which have been shown to regulate functionally relevant Hox expression in the neurectoderm. A similar crucial function for any RARE in mesodermal Hox expression has, however, not been documented. The means by which RA regulates mesodermal Hox expression could therefore be either through an undocumented direct mechanism or through an intermediary; these mechanisms are not necessarily exclusive. In this regard, we have found that Cdx1 may serve as such an intermediary. Cdx1 encodes a homeobox transcription factor that is crucial for normal somitic expression of several Hox genes, and is regulated by retinoid signalling in vivo and in vitro likely through an atypical RARE in the proximal promoter. In order to more fully understand the relationship between retinoid signalling, Cdx1 expression and AP patterning, we have derived mice in which the RARE has been functionally inactivated. These RARE-null mutants exhibit reduced expression of Cdx1 at all stages examined, vertebral homeotic transformations and altered Hox gene expression which correlates with certain of the defects seen in Cdx1-null offspring. These findings are consistent with a pivotal role for retinoid signalling in governing a subset of expression of Cdx1 crucial for normal vertebral patterning.

Animals↗
PubMed2005

Fgf signals from a novel signaling center determine axial patterning of the prospective neural retina.

Axial eye patterning determines the positional code of retinal ganglion cells (RGCs), which is crucial for their topographic projection to the midbrain. Several asymmetrically expressed determinants of retinal patterning are known, but it is unclear how axial polarity is first established. We find that Fgf signals, including Fgf8, determine retinal patterning along the nasotemporal (NT) axis during early zebrafish embryogenesis: Fgf8 induces nasal and/or suppresses temporal retinal cell fates; and inhibition of all Fgf-receptor signaling leads to complete retinal temporalization and concomitant loss of all nasal fates. Misprojections of RGCs with Fgf-dependent alterations in retinal patterning to the midbrain demonstrate the importance of this early patterning process for late topographic map formation. The crucial period of Fgf-dependent patterning is at the onset of eye morphogenesis. Fgf8 expression, the restricted temporal requirement for Fgf-receptor signaling and target gene expression at this stage suggests that the telencephalic primordium is the source of Fgf8 and acts as novel signaling center for non-autonomous axial patterning of the prospective neural retina.

Animals↗
PubMed1996

Structure of the insect head as revealed by the EN protein pattern in developing embryos.

The structure of the insect head has long been a topic of enjoyable yet endless debate among entomologists. More recently geneticists and molecular biologists trying to better understand the structure of the head of the Dipteran Drosophila melanogaster have joined the discourse extrapolating from what they have learned about Drosophila to insects in general. Here we present the results of an investigation into the structure of the insect head as revealed by the distribution of engrailed related protein (Engrailed) in the insect orders Diptera, Siphonaptera, Orthoptera and Hemiptera. The results of this comparative embryology in conjunction with genetic experiments on Drosophila melanogaster lead us to conclude: (1) The insect head is composed of six Engrailed accumulating segments, four postoral and two preoral. The potential seventh and eighth segments (clypeus or labrum) do not accumulate Engrailed. (2) The structure known as the dorsal ridge is not specific to the Diptera but is homologous to structures found in other insect orders. (3) A part of this structure is a single segment-like entity composed of labial and maxillary segment derivatives which produce the most anterior cuticle capable of taking a dorsal fate. The segments anterior to the maxillary segment produce only ventral structures. (4) As in Drosophila, the process of segmentation of the insect head is fundamentally different from the process of segmentation in the trunk. (5) The pattern of Engrailed accumulation and its presumed role in the specification and development of head segments appears to be highly conserved while its role in other pattern formation events and tissue-specific expression is variable. An overview of the pattern of Engrailed accumulation in developing insect embryos provides a basis for discussion of the generality of the parasegment and the evolution of Engrailed patterns.

Animals↗
PubMed1996

Xenopus VegT RNA is localized to the vegetal cortex during oogenesis and encodes a novel T-box transcription factor involved in mesodermal patterning.

An RNA localized to the vegetal cortex of Xenopus oocytes encodes a novel T-box protein (VegT) capable of inducing either dorsal or posterior ventral mesoderm at different times in development. VegT is a nuclear protein and its C-terminal domain can activate transcription in a yeast reporter assay, observations consistent with VegT functioning as a transcription factor. Zygotic expression is dynamic along the dorsoventral axis, with transcripts first expressed in the dorsal marginal zone. By the end of gastrulation, VegT is expressed exclusively in posterior ventral and lateral mesoderm and is excluded from the notochord. Later expression is confined to a subset of Rohon-Beard cells, a type of primary sensory neuron. In animal cap assays, VegT is capable of converting prospective ectoderm into ventral lateral mesoderm. Such ectopic expression of VegT induces its own expression as well as that of Xwnt-8 in caps, suggesting that a Wnt pathway may be involved. Mis-expression of VegT in dorsal animal blastomeres fated to contribute to brain suppresses head formation. Our results suggest that VegT is a localized transcription factor, which operates sequentially in several developmental pathways during embryogenesis, including dorsoventral and posterior patterning of mesoderm.

Amino Acid Sequence↗
PubMed1998

The Dorsal-related immunity factor (Dif) can define the dorsal-ventral axis of polarity in the Drosophila embryo.

In Drosophila embryos, dorsal-ventral polarity is defined by a signal transduction pathway that regulates nuclear import of the Dorsal protein. Dorsal protein's ability to act as a transcriptional activator of some zygotic genes and a repressor of others defines structure along the dorsal-ventral axis. Dorsal is a member of a group of proteins, the Rel-homologous proteins, whose activity is regulated at the level of nuclear localization. Dif, a more recently identified Drosophila Rel-homologue, has been proposed to act as a mediator of the immune response in Drosophila. In an effort to understand the function and regulation of Rel-homologous proteins in Drosophila, we have expressed Dif protein in Drosophila embryos derived from dorsal mutant mothers. We found that the Dif protein was capable of restoring embryonic dorsal-ventral pattern elements and was able to define polarity correctly with respect to the orientation of the egg shell. This, together with the observation that the ability of Dif to restore a dorsal-ventral axis depended on the signal transduction pathway that normally regulates Dorsal, suggests that Dif protein formed a nuclear concentration gradient similar to that seen for Dorsal. By studying the expression of Dorsal target genes we found that Dif could activate the zygotic genes that Dorsal activates and repress the genes repressed by Dorsal. Differences in the expression of these target genes, as well as the results from interaction studies carried out in yeast, suggest that Dif is not capable of synergizing with the basic helix-loop-helix transcription factors with which Dorsal normally interacts, and thereby lacks an important component of Dorsal-mediated pattern formation.

Animals↗
PubMed1999

The Caenorhabditis elegans genes egl-27 and egr-1 are similar to MTA1, a member of a chromatin regulatory complex, and are redundantly required for embryonic patterning.

We show here that two functionally redundant Caenorhabditis elegans genes, egl-27 and egr-1, have a fundamental role in embryonic patterning. When both are inactivated, cells in essentially all regions of the embryo fail to be properly organised. Tissue determination and differentiation are unaffected and many zygotic patterning genes are expressed normally, including HOX genes. However, hlh-8, a target of the HOX gene mab-5, is not expressed. egl-27 and egr-1 are members of a gene family that includes MTA1, a human gene with elevated expression in metastatic carcinomas. MTA1 is a component of a protein complex with histone deacetylase and nucleosome remodelling activities. We propose that EGL-27 and EGR-1 function as part of a chromatin regulatory complex required for the function of regional patterning genes.

Amino Acid Sequence↗
PubMed1999

Anteroposterior patterning of the epidermis by inductive influences from the vegetal hemisphere cells in the ascidian embryo.

Patterning along the anteroposterior axis is a critical step during animal embryogenesis. Although mechanisms of anteroposterior patterning in the neural tube have been studied in various chordates, little is known about those of the epidermis. To approach this issue, we investigated patterning mechanisms of the epidermis in the ascidian embryo. First we examined expression of homeobox genes (Hrdll-1, Hroth, HrHox-1 and Hrcad) in the epidermis. Hrdll-1 is expressed in the anterior tip of the epidermis that later forms the adhesive papillae, while Hroth is expressed in the anterior part of the trunk epidermis. HrHox-1 and Hrcad are expressed in middle and posterior parts of the epidermis, respectively. These data suggested that the epidermis of the ascidian embryo is patterned anteroposteriorly. In ascidian embryogenesis, the epidermis is exclusively derived from animal hemisphere cells. To investigate regulation of expression of the four homeobox genes in the epidermis by vegetal hemisphere cells, we next performed hemisphere isolation and cell ablation experiments. We showed that removal of the vegetal cells before the late 16-cell stage results in loss of expression of these homeobox genes in the animal hemisphere cells. Expression of Hrdll-1 and Hroth depends on contact with the anterior-vegetal (the A-line) cells, while expression of HrHox-1 and Hrcad requires contact with the posterior-vegetal (the B-line) cells. We also demonstrated that contact with the vegetal cells until the late 32-cell stage is sufficient for animal cells to express Hrdll-1, Hroth and Hrcad, while longer contact is necessary for HrHox-1 expression. Contact with the A-line cells until the late 32-cell stage is also sufficient for formation of the adhesive papillae. Our data indicate that the epidermis of the ascidian embryo is patterned along the anteroposterior axis by multiple inductive influences from the vegetal hemisphere cells and provide the first insight into mechanisms of epidermis patterning in the chordate embryos.

Animals↗
PubMed2001

A positive role for Short gastrulation in modulating BMP signaling during dorsoventral patterning in the Drosophila embryo.

Positional information in the dorsoventral axis of the Drosophila embryo is encoded by a BMP activity gradient formed by synergistic signaling between the BMP family members Decapentaplegic (DPP) and Screw (SCW). short gastrulation (sog), which is functionally homologous to Xenopus Chordin, is expressed in the ventrolateral regions of the embryo and has been shown to act as a local antagonist of BMP signaling. Here we demonstrate that SOG has a second function, which is to promote BMP signaling on the dorsal side of the embryo. We show that a weak, homozygous-viable sog mutant is enhanced to lethality by reduction in the activities of the Smad family members Mad or Medea, and that the lethality is caused by defects in the molecular specification and subsequent cellular differentiation of the dorsal-most cell type, the amnioserosa. While previous data had suggested that the negative function of SOG is directed against SCW, we present data that suggests that the positive activity of SOG is directed towards DPP. We demonstrate that Chordin shares the same apparent ligand specificity as does SOG, preferentially inhibiting SCW but not DPP activity. However, in Drosophila assays Chordin does not have the same capacity to elevate BMP signaling as does SOG, identifying a functional difference in the otherwise well conserved process of dorsoventral pattern formation in arthropods and chordates.

Animals↗
PubMed2002

Linear signaling in the Toll-Dorsal pathway of Drosophila: activated Pelle kinase specifies all threshold outputs of gene expression while the bHLH protein Twist specifies a subset.

Differential activation of the Toll receptor leads to the formation of a broad Dorsal nuclear gradient that specifies at least three patterning thresholds of gene activity along the dorsoventral axis of precellular embryos. We investigate the activities of the Pelle kinase and Twist basic helix-loop-helix (bHLH) transcription factor in transducing Toll signaling. Pelle functions downstream of Toll to release Dorsal from the Cactus inhibitor. Twist is an immediate-early gene that is activated upon entry of Dorsal into nuclei. Transgenes misexpressing Pelle and Twist were introduced into different mutant backgrounds and the patterning activities were visualized using various target genes that respond to different thresholds of Toll-Dorsal signaling. These studies suggest that an anteroposterior gradient of Pelle kinase activity is sufficient to generate all known Toll-Dorsal patterning thresholds and that Twist can function as a gradient morphogen to establish at least two distinct dorsoventral patterning thresholds. We discuss how the Dorsal gradient system can be modified during metazoan evolution and conclude that Dorsal-Twist interactions are distinct from the interplay between Bicoid and Hunchback, which pattern the anteroposterior axis.

Animals↗
PubMed2001

Growth dynamics of the developing lateral geniculate nucleus.

Segregated binocular maps in the lateral geniculate nucleus (LGN) develop from stages where they initially completely overlap. Here, we show that segregation occurs at different rates across the depth of the nucleus and that the volume of the ipsilateral projection does not decrease significantly during this period, rather LGN volume expands markedly and its shape changes. Hence, we have examined the differential growth of the ferret LGN during the process of segregation by using novel shape modelling techniques. These have facilitated quantification of its three-dimensional structure at successive developmental stages as well as the definition of growth vectors which illustrate shape change. This has been undertaken in direct representations of the LGN and those normalised for size and orientation. Spatiotemporal aspects of shape change have then been compared with different measurements of its cellular population. Initial stages of segregation are associated with a large expansion of the rostrocaudal axis of the nucleus along which segregation takes place, and an expansion of caudal regions that will eventually contain the binocular representation. Later stages are associated with dorsoventral expansions and a consolidation of the rostrocaudal axis. The pace of shape change peaks toward the end of the period of segregation when the nucleus has adopted approximately 50% of its adult shape. After segregation, nuclear growth is mainly isotropic. The mature shape of the nucleus is achieved before it reaches its full size and while cell density and cell sizes are still changing.

Age Factors↗
PubMedDate not supplied

Successive resetting of the set point for target body size.

Previous studies support the existence of a central set point for target body size. The set point is a hypothetical fixed reference for body size. The present experiments were carried out to determine whether target body size and, by implication, the putative set point can be consecutively reset or whether, once set by an extraneous factor, it is refractory to another extraneous factor. Male and female rats were given 6.0 Gy whole head X-irradiation at two days of age or were sham-irradiated as controls. Significant permanent reduction of body weight, tibia length, and pituitary weight resulted from head-irradiation in both males and females; gonad weight was reduced in males but not significantly in females. At 41 days of age the irradiated animals were injected sc with cortisone acetate, 1 mg/25 g body weight/day, or saline. During cortisone treatment the head-irradiated rats had a decrease in body weight velocity; the effect was greater in males than in females. Following treatment growth velocity approached normal in treated males, and slightly exceeded normal in treated females. Treated males had significantly reduced body weight, tail length, and tibia length at the end of the study. Treated females showed a similar pattern of body weight growth to the treated males, but there was not a significant long term reduction of body weight or change in tail length or tibia length. Final pituitary and gonad size was not affected by cortisone treatment in either sex. The results indicate that the reset of target size after head-irradiation does not result from damage to putative control.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1996

Patterning the cranial neural crest.

The pattern of skeletal elements and musculature in the branchial region of the chick embryo is profoundly influenced by the neural crest which migrates in separate streams. Neural crest emigration from the hindbrain into the branchial arches is discontinuous, and regions of crest production are separated from each other by two regions of crest apoptosis, rhombomeres (r) 3 and 5. Both r3 and r5 produce large numbers of crest cells when they are cultured in isolation; but, when co-cultured with their neighbouring segment neural crest apoptosis is restored. The expression of the signalling molecule Bmp-4 and the gene msx-2 in apoptotic domains of r3 and r5 is also dependent upon neighbour interactions and the addition of recombinant Bmp-4 to explant cultures of r3/r5 upregulates both Bmp-4 and msx-2 expression and restores apoptosis. This interactive mechanism acts to ensure the sculpting of crest outflow into non-mixing streams and, consequently, the fidelity of pattern transfer into the branchial arches.

Animals↗
PubMed1997

Spatially distinct domains of cell behavior in the zebrafish organizer region.

To determine the sequence of cell behaviors that is involved in the morphogenesis of the zebrafish organizer region, we have examined the dorsal marginal zone of vitally stained zebrafish embryos using time-lapse confocal microscopy. During the late-blastula stage, the zebrafish dorsal marginal zone segregates into several cellular domains, including a group of noninvoluting, highly endocytic marginal (NEM) cells. The NEM cell cluster, which lies in a superficial location of the dorsal marginal zone, is composed of both enveloping layer cells and one or two layers of underlying deep cells. The longitudinal position of this cellular domain accurately predicts the site of embryonic shield formation and occupies a homologous location to the organizer epithelium in Xenopus laevis. At the onset of gastrulation, deep cells underneath the superficial NEM cell domain undergo involution to form the nascent hypoblast of the embryonic shield. Deep cells within the NEM cell cluster, however, do not involute during early shield formation, but instead move in front of the blastoderm margin to form a loose mass of cells called forerunner cells. Forerunner cells coalesce into a wedge-shaped mass during late gastrulation and eventually become overlapped by the converging lateral lips of the germ ring. During early zebrafish tail elongation, most forerunner cells are incorporated into the epithelial lining of Kupffer's vesicle, a transient teleostean organ rudiment long thought to be an evolutionary vestige of the neurenteric canal. Owing to the location of NEM cells at the dorsal margin of blastula-stage embryos, as well as their early segregation from other deep cells, we hypothesized that NEM cells are specified by an early-acting dorsalizing signal. To test this possibility, we briefly treated early-blastula stage embryos with LiCl, an agent known to produce hyperdorsalized zebrafish embryos with varying degrees of expanded organizer tissue. In Li(+)-treated embryos, NEM cells appear either within expanded spatial domains or in ectopic locations, primarily within the marginal zone of the blastoderm. These results suggest that NEM cells represent a specific cell type that is specified by an early dorsal patterning pathway.

Animals↗
PubMed1995

A comparative study of generalised obesity and anatomical distribution of subcutaneous fat in adult white and Pakistani migrant males in Peterborough.

Obesity can be defined in two main ways--generalised obesity (measured as Body Mass Index (BMI)) and anatomical distribution of adiposity. A comparative study of generalised obesity (body mass index) and the anatomical distribution of subcutaneous fat in adult White and Pakistani migrant males was carried out in Peterborough. No significant difference in the prevalence of obesity as measured by the BMI was observed between Whites and Pakistani migrants. The mean BMI values were similar in both ethnic groups. However, Pakistanis had significantly more truncal fat compared with Whites whereas the latter group had more upper extremity fat compared with the former. No significant difference was observed in the amount of fat deposited on the lower extremities between the two ethnic groups. The Pakistanis also had significantly more total (sum of all skinfolds) subcutaneous fat compared with Whites. These preliminary results clearly indicate that there is a tendency for accumulation of truncal adiposity in Asians of Pakistani origin compared with Whites irrespective of the level of generalised (BMI) obesity. The health implications of body fat patterning on non-insulin-dependent diabetes mellitus (NIDDM) and coronary heart disease (CHD) are well known. It is possible that the pattern of fat distribution observed in migrant Pakistani males in this study exists in other migrant groups originating from the Indian subcontinent. This pronounced truncal distribution of body fat could be one of the risk factors predisposing migrant Asians in the UK to develop NIDDM and CHD irrespective of their BMI. Future epidemiological studies should lay more emphasis on morphological fat patterning rather than BMI in Asian migrants in the UK.

Adipose Tissue↗
PubMedDate not supplied

Prenatal smoke exposure alters growth in limb proportions and head shape in the midgestation human fetus.

The objective of this study was to examine the effects of smoke exposure on the growth patterns of the head, limbs, and torso of the midgestation human fetus. Four hundred maternal/fetal pairs contributed to this analysis: 366 individuals were assessed cross-sectionally (87 smokers and 279 nonsmokers) at approximately 20 and 32 weeks, and 34 individuals were followed longitudinally at 23, 27, and 32 weeks (10 smokers, 24 nonsmokers). Ten body parameters were measured by fetal ultrasound. In both samples, controlling for day of measurement, smoke exposure was significantly associated with early growth acceleration in head and abdominal diameters at 20-27 weeks (P < 0.05). This was followed by altered head shape (a significantly smaller biparietal to occipital frontal diameter ratio at 32 weeks, P < 0.01), and a proximal/distal growth gradient as proportionately long arms (P < 0.05 at 27 and 32 weeks) and short legs were apparent by 32 weeks, with a significant reduction in the tibia/femur ratio (P = 0.04). These fetal body growth patterns, expressed in terms of size and proportionality, are consistent with the presence of chronic hypoxia associated with maternal smoking. The growth pattern differences identify that prenatal smoking is not merely an insult resulting in consistent size and growth rate reduction across developmental ages. Instead, smoke exposure alters the growth rate of individual body segments at variable developmental stages as the fetus experiences selective growth restriction and augmentation. We hypothesize that the growth patterns observed here reflect the unique pattern of fetal blood flow favoring upper body oxygen distribution and extraction, together with genetically based adaptive strategies that permit the fetus to adjust the timing and magnitude of its growth to local environmental resources. It is possible that dolichocephaly is a previously unappreciated marker of fetal hypoxia. Reduced tibial growth may be a good marker for shortfall and a useful proxy for the adequacy of circulating resources more generally.

Anthropometry↗